diff --git a/-DwGrJ8JxDc.txt b/-DwGrJ8JxDc.txt new file mode 100644 index 0000000000000000000000000000000000000000..96252da30481b0b0273802fdccd021e02ffe3efe --- /dev/null +++ b/-DwGrJ8JxDc.txt @@ -0,0 +1,3045 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation, or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: The things we +can talk about today, we + +can talk about this code. + +We can talk a little bit more +about the hash functions. + +And we can talk a little +bit more about amortization. + +What to do guys want to hear? + +AUDIENCE: Amoritizaiton. + +PROFESSOR: OK, so one +vote for amortization. + +So who wants to look +at the PSET code? + +Who wants to talk about hashes? + +Who wants to talk +about amortization? + +Two, three, four, five, OK. + +So then let's try this. + +Let's look at the PSET code then +talk about amortization a bit + +at the end. + +I do have to talk a +little bit about hashes + +though, because I owe someone +a question from last time. + +And the question was, +we have rolling hashes, + +so the hashes look like this. + +K where K is a big +number, modulo p. + +And we argue that it's +really nice if p is a prime. + +And then the question was, what +if instead p is 2 to the w, + +and is not prime, as long +as the base that we're using + +is co-prime with p? + +Does this work? + +And the answer +is-- I didn't want + +to say yes without making sure +that I don't say something + +stupid-- but the +answer is yes, this + +works just fine, because the +way a compute multiplicative + +inverse is is you +use so something + +called the extended +Euclid's method. + +And if we have b and p, then +if we compute their GCD, + +the that's the greatest common +divisor-- so GCD is greatest-- + +If you use extended Euclid you +get something like xb plus yp + +equals GCD of b and p. + +So if this is 1, then you +have xb plus yp equals 1. + +And if you're working +modulo p, whatever that is, + +then you have that +xb is 1 mod p. + +So there's your +multiplicative inverse. + +Well so now that's +nice math, right? + +But that doesn't tell me +why are we not using this. + +So with the multiplicative +inverse would work, + +but there's +something else that's + +wrong with using 2 to the w. + +Will this give me a +good hash function? + +OK, the fact that it's +p might be confusing. + +So let's say h equals +K mod 2 to the w. + +And remember that the K is +some digits in base b, right? + +It's a big number made +out of digits in base b. + +So K is d1, d2, d3, all the way +up until d length in base b. + +And I'll make things easier +and say that b is 2 to the 8, + +because we're working with +ASCII characters, or colors, + +or something that +fits nicely in a bit. + +So what could go +wrong with using this? + +AUDIENCE: Well if your series +of-- if your K is bigger than + +2-- if it's K is bigger +than 2 to the w-- + +PROFESSOR: It will be, for sure. + +AUDIENCE: Yes, that's the +problem, because then you'll + +loop. + +You'll get the same hashes for-- + +PROFESSOR: Yeah, yeah. + +So you will get-- So hashing +takes a lot of possible inputs + +and maps them to a relatively +small set of outputs. + +Inputs hash output. + +And we argued last +time that we're + +going to have collisions +no matter what, + +because we have a ton of inputs +and not that many outputs. + +For example, if +we're hashing strings + +that are a million +characters then this + +is going to be 2 to the 8 to +the 1 million possible strings. + +And then the number +of possible values + +is, if we're using the +word size, 2 to the 32. + +There is no way we can +design a function that + +will take this many inputs, +map them to this many outputs, + +and not do collisions. + +But instead, what do we want? + +What makes a good hash function? + +Say my hash function +is 0 for all the K's. + +Is that a good hash function? + +AUDIENCE: It's an +excellent hash function. + +PROFESSOR: What's wrong with it? + +AUDIENCE: You would +put everything in one + +so that it's searching, or +it would take a long time? + +PROFESSOR: Yeah, searching +takes a long time. + +And we've don't do +sorting with this yet. + +Searching takes a long +time, string sub-matching + +will take a long +time, it's horrible. + +AUDIENCE: So what +would that distribute-- + +like [INAUDIBLE] over all-- + +PROFESSOR: All right, +so we want something + +that looks sort of random. + +The ideals hash function +takes an input then + +gives it a random output, +and then stays consistent. + +So when it sees an input, +returns the same output. + +So I think distribute +is the keyword here. + +What's wrong with +this hash function? + +If it takes random +data, it's going + +to distribute it randomly. + +That's true, so that's all good. + +But what data that we +might see in real life + +will make it behave badly? + +AUDIENCE: The K is a series +of characters, right? + +PROFESSOR: Maybe. + +AUDIENCE: It just +could be anything. + +But we know for sure that +L will be larger than w. + +PROFESSOR: Say L is a million. + +AUDIENCE: OK, well that sucks. + +PROFESSOR: Oh, no. + +That in itself, +that doesn't suck. + +That's what let's us do +sub-string matching really + +fast, even if we +have large strings. + +AUDIENCE: --say for +2 to the w, though, + +because then it will be much +larger, like the number of-- + +PROFESSOR: Yeah, but that's OK. + +So I'm OK with doing this as +long as all the values here + +are distributed sort +of uniformly here. + +So that's fine. + +AUDIENCE: OK. + +PROFESSOR: But there's-- I'm +arguing that there are some + +values which will make this +hash function behave badly. + +And that those values are so +simple that we might see them + +in real life. + +OK, what if all these +numbers are-- what + +if all the digits are even? + +So d is 0 mod 2. + +What happens to K? + +AUDIENCE: Well, you're saying +that instead of 2 to the w, + +we're just using 2. + +PROFESSOR: So no, the +modulo is 2 to the w. + +Say it's 2 to the 32. + +So d are the digits that +make up my K. So what + +if the base is 2 to the 8? + +So I have digits from +0 to 255, 256 of them. + +And all the digits +are 0 modulo 2. + +For my sub-string +matching example, + +what if all the characters +in the sub-string are even? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Not the same thing. + +But there's a problem. + +They will hash to-- so +if all the digits are + +0 modulo 2 then +what about the K? + +AUDIENCE: [INAUDIBLE] +0 modulo 2-- + +PROFESSOR: Yep. + +So it's just like when you +have numbers in base 10. + +10 happens to be divisible by 2. + +So if your last digit is even, +then the entire number is even. + +That makes sense, right? + +That's math. + +Please nod, tell me +that I'm making sense. + +OK, so here, the base is 256. + +And it's also divisible by 2. + +So if your last digit +is divisible by 2, + +then the whole number +is divisible by 2. + +So then if I take this +K modulo 2 to the 32 + +then the hash is also +going to be divisible by 2. + +AUDIENCE: Why does it matter +if the hash is divisible by 2? + +PROFESSOR: So it +matters because this + +is supposed to be +my universe, right? + +These are supposed to +be all the outputs. + +And I'm saying that if +my inputs look like this, + +then the hash function will +not distribute them uniformly. + +Instead, if this is my +possible set of outputs, + +the hash function will always +put outputs in this half. + +So the outputs will +always be here. + +And these are the numbers +that are divisible by 2. + +So these are even, +and these are odd. + +And this area gets no love. + +Absolutely no number +will hash here. + +So-- + +AUDIENCE: Wait, what about +something with all odds? + +AUDIENCE: Something +with all odd digits? + +AUDIENCE: Because +you're asking-- + +AUDIENCE: You have +all A's rather than + +all B's in your sub-string +or in your string. + +AUDIENCE: Or because +your last digit was odd. + +PROFESSOR: If all of +our digits are odd + +then the last digit is odd. + +And then you'd also get +something odd, right? + +AUDIENCE: Yeah. + +AUDIENCE: So there's a pattern. + +But there's an +even distribution. + +PROFESSOR: Well if your +hash function is always odd, + +then it's not an +even distribution. + +It's-- + +AUDIENCE: Wait, +our hash function? + +I thought we were +talking about-- + +AUDIENCE: Isn't it +even if your K is even? + +And if it's odd [INAUDIBLE]? + +PROFESSOR: Yeah, so that's bad. + +Because if all your K's +happens to be even-- + +say if you're doing +the nucleotides, + +and the nucleotides +are A, C, G, T. + +If they happen to be +encoded as, say, 0, 2, 4, 6, + +then these are all even. + +So the hash function +will always be even + +and I'm wasting the last bit. + +So if I'm building a hash +table, half the entries + +will be wasted. + +They'll never get +anything in there. + +I'm just wasting memory. + +AUDIENCE: So if +you could guarantee + +that your inputs would +be evenly distributed-- + +PROFESSOR: So if our +inputs are random + +then the hash function-- +most hash functions will + +do a good job of +producing a random output. + +The problem is real life +inputs are not random. + +For example, if you +get-- asides from this-- + +if you get data from a camera, +so if you get your color pixels + +from a camera, then +because of noise those + +might have the last few bits, +always be the same thing. + +Also it seems like in +real life-- [INAUDIBLE], + +in his book, argues about this. + +It seems like in +real life there are + +a lot of sequences that look +like that, that would make + +your hash function +behave poorly. + +So again, the keyword +is distribute. + +If some non-random +property in the input + +is reflected in the output, +then that's a bad hash function. + +AUDIENCE: Would you +gain a lot of time + +from your mod operation? + +Because in mod 2 to the n +you just truncate any bits + +to the left of the n. + +PROFESSOR: Yeah, so that's +why we would do this, right? + +That's why we're even +considering this case. + +AUDIENCE: Because that'd be +really nice to be able to not-- + +PROFESSOR: So modulo is faster, +but in return my hash function + +is crap here. + +So usually we prefer-- it turns +out that in practice nicer hash + +functions give better +speed improvements overall. + +So if you think of how a +hash is laid out in memory, + +you'll see that +because of caching. + +And everything gets better +to take more time on the mod + +function and use up all your +memory for the hash table. + +So this is why we don't +use the and we use this. + +Not because of this argument. + +So a good question required a +lot of talking and remembering + +what's a good hash function, +what's a bad hash function. + +Thank you. + +OK, let's look at the +code a little bit. + +Everyone looked at it, right? + +So this time we have modules. + +We don't have everything +in one big file. + +Can someone tell me what are the +modules we care about, and why? + +AUDIENCE: The problem +with the one's + +we have to code ourselves. + +PROFESSOR: OK, let's +start with that. + +AUDIENCE: Sub-sequence hashes-- +interval sub-sequence hashes. + +PROFESSOR: OK, so these +are all in DNA seq, right? + +So the module is-- so +yeah, the PSET hopefully + +says that you need to upload +this file because it's + +the only file you'll +need to modify. + +So everything that we +need to write is here. + +Now pretty much everything +that's in that file + +needs to be modified. + +So I'm not going +to list them out. + +What else do we want +to read in that PSET? + +AUDIENCE: Rolling [INAUDIBLE] + +PROFESSOR: OK, where +is rolling hash? + +AUDIENCE: In the [INAUDIBLE] + +PROFESSOR: So what's different +between the API in rolling hash + +and the API that we +talked about last time? + +Yes? + +AUDIENCE: Them having +the [INAUDIBLE] pop, + +or it would skip. + +And that's something else +[INAUDIBLE] just has a slide, + +it puts everything +in one operation. + +PROFESSOR: All right, so +we have append and skip. + +And we built some +beautiful code with that. + +And we looked at some +fancy math because of it. + +But it turns out +that for this PSET + +we can get away with slide. + +And we started from slide +and built these two methods + +last time. + +So I'm not going to +explain slide again. + +It's exactly what +we had in the code + +before we started +breaking them up. + +OK so this is the rolling hash. + +It is good. + +Do we care about anything else? + +AUDIENCE: I guess you can +look at the rest of the code, + +if you feel like it. + +PROFESSOR: You can look +at the rest of the code + +if you feel like it, yep. + +So I highlighted one file +that might be useful, + +and that's Kfasta.py. + +That file has a +FASTA sequence class, + +and that's reads from a +file and returns something. + +And the important thing is +it doesn't return a list. + +If you remember the doc +dists, doc dist 1 thorugh doc + +dist 8 dot PI, fun times. + +What we had there was +we took the input file, + +and we read it all a list. + +This time we're not doing that. + +We're writing, what, 20 +lines of code instead of what + +could be five lines of +code to read the input. + +Why is that? + +AUDIENCE: Less memory? + +PROFESSOR: Less memory, OK. + +So if we're doing +it this way, chances + +are that if we tried to shove +the whole input into memory, + +it wouldn't fit. + +And it would crash +and you would get 0 + +on the test because of that. + +So that's not good. + +So what do we use instead? + +Does anyone know what +this thing is called? + +What this class is called? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Iterator, very good. + +AUDIENCE: Why do +they call it FASTA? + +Because it goes faster? + +PROFESSOR: I think the +letters are a bio acronym. + +AUDIENCE: Oh, OK. + +PROFESSOR: Does anyone, +does anyone do bio here? + +I've seen that before. + +So it's a bio thing. + +Let's not worry about it. + +AUDIENCE: OK. + +Or, your can use that +for any type of file. + +Like, you don't have to +use it just for bio files. + +PROFESSOR: Well, +presumably it's reads, + +it takes advantage of the +format that they're stored in, + +and gives you a list +instead of something else. + +So how does an iterator work? + +Suppose you're building +your own iterator. + +What do you have to implement? + +AUDIENCE: Iterator [INAUDIBLE] + +PROFESSOR: OK, let's start +with next, that's the fun one. + +What does next do? + +AUDIENCE: It's like pop. + +PROFESSOR: OK, so it's +like pop in what way? + +AUDIENCE: It gives you +the next character. + +PROFESSOR: OK. + +And what happens when you're +at the end of the list? + +AUDIENCE: It stops. + +PROFESSOR: How do you stop? + +AUDIENCE: It raises +an exception? + +PROFESSOR: So next will +either return an element, + +that's the next +element in the sequence + +that you're iterating over. + +Or it will raise a stop +iteration exception + +error to stop iteration, cool. + +So what's the other method? + +Someone said it +before, say it again. + +AUDIENCE: Iter. + +PROFESSOR: Iter. + +What does this do +in an iterator? + +AUDIENCE: It returns itself. + +PROFESSOR: All right, very good. + +In an iterator this is how you +will implement it all the time. + +Does anyone know what's +the point of iter? + +AUDIENCE: So you can +return an iterator? + +Because that's what it +told us to do in the PSET. + +PROFESSOR: OK, so iter +returns and iterator. + +But it doesn't-- you don't +have to start from an iterator. + +You can start from any object. + +And if it has a +method iter, then it + +should give you an iterator +that iterates over that object. + +So if you have something like +a list-- 1, 2, 3, 4-- then + +if you call iter on this, +you'll get an iterator for it, + +hopefully, right? + +And this is what Python +uses when you say for i in. + +So behind the scenes, whatever +object you give it here, + +gets an iter call. + +And then that +produces an iterator. + +And then Python calls next +until stop iteration happens. + +So you can write +an iterator that + +almost behaves like a list. + +You can use it in these +[INAUDIBLE] instructions, + +and it works as +if it was a list, + +except it uses a lot less +memory, because it computes + +the elements. + +Hopefully every +time next is called, + +you're computing the next +element that you're returning. + +If you're storing everything +in a list then returning + +the elements that way, that's +not the very smart iterator. + +OK let's look at the last page. + +So the last page has +an iterator on top. + +And the iterator +computes-- given a list, + +it computes the +reverse of that list. + +And you can see that it +doesn't reverse the list + +and then keep the +reversed list in memory. + +Instead, every +time you call next, + +it does some magic +with the indexes-- + +I think the magic +is called math-- + +and then it return something +for as long as it can. + +So this is how you +implement reverse + +without producing a new list. + +If the original list was +order, say had n elements, then + +if you'd produce a new list, +you'd consume order and memory. + +This think consumes +order 1 memory, + +and the running time is +the same, asymptotically. + +OK, any question on iterators? + +AUDIENCE: So it's going +from the very end, + +oh, to the very beginning, +and then it's stepping back. + +PROFESSOR: So +reverse, if I give it + +the list 1, 2, 3, 4, I want +reverse to give it back 4, 3, + +2, 1. + +Except it's not going +to return a list, + +it's going to return +something that I can use here. + +AUDIENCE: Mm hm, ah, OK. + +PROFESSOR: OK, yes. + +AUDIENCE: Is it ever +possible to, sort of, + +rewind the iterator to +like, sort of, reset it? + +PROFESSOR: OK, is it? + +AUDIENCE: No. + +PROFESSOR: Nope. + +So Python iterators are simple. + +All you can do is go forward. + +AUDIENCE: OK. + +PROFESSOR: The reason +that is good is + +because you can use +them for streams. + +So if you get data from a +file, or if you can get data + +from the network, you can +wrap it in an iterator. + +If you wanted to support +resume on data that you + +get from the network, you'd +have to buffer all the data. + +AUDIENCE: So you +would have to call + +the iter about that again and-- + +PROFESSOR: Yeah. + +Yeah, if you want to rewind, +get another iterator. + +OK, that's a good +question, thank you. + +So these are iterators. + +Now we're going to go over +some Python magic, which + +is called generators. + +So look at the iterator +code, and then look + +at the equivalent +code right below it. + +So 12 lines of Python turned +into three lines of Python + +that do exactly the same thing. + +So the reverse method +will return an object + +that is an iterator, and +that you can use just + +like the iterator in +the reverse class. + +Do people understand +what that code does? + +If you do I'm so out +of here, we're done. + +AUDIENCE: What does yield do? + +PROFESSOR: What does yield do? + +All right, that's the hard +question, what does yield do? + +I will probably spend the rest +of the session on the answer + +to that question. + +You're asking all the +had questions today, man. + +So yield, does anyone know +conceptually what yield does? + +Not in detail, just +what's it supposed + +to do so that the rest +of the code works? + +Yes. + +AUDIENCE: If you're +driving someplace + +and there's a yield +sign, you pause. + +PROFESSOR: OK, Python yield. + +So I like the word +pause in there. + +The word pause is useful. + +So say, instead of +implementing this, + +say we're implementing +sub-sequence hashes. + +AUDIENCE: It kind of spit +something out, but keeps going. + +PROFESSOR: Yep. + +AUDIENCE: Returns [INAUDIBLE] + +PROFESSOR: OK, so suppose +you're implementing + +sub-sequence hashes. + +What's the worst, worst possible +way you could implement this? + +AUDIENCE: Return a list. + +PROFESSOR: OK, so the worst, +worst way is to go all the way, + +brute force, don't use +the rolling hashes, + +don't use anything. + +The next best way is +to make a list, right? + +So you're going to start +with an empty list. + +Then you're going to use the +rolling hash in some way. + +And in some loop you're +going to say list.append e. + +And then you're going +to return the list. + +Does this makes sense? + +OK, what's the problem +with this code? + +AUDIENCE: You're going +to have a huge list. + +PROFESSOR: Going to +have a huge list. + +So the way we fix it with +iterators is we remove this, + +we replace this with yield +e, and we remove this. + +And now it's a generator. + +And now this consumes a +constant amount of memory, + +instead of building a list. + +And as long as you only want +an iterator out of this method, + +you'll get the right thing. + +Your code will still work +in exactly the same way. + +OK, so the big question is +what does this guy do, right? + +This is where the magic is. + +So I already said, +as a first hint, + +that this guy will +return an iterator. + +So can someone try to imagine +their Python, and see this? + +So suppose it's your +Python, you see this. + +What do you do? + +AUDIENCE: You wait for some sort +of command of some sort, right? + +PROFESSOR: No, let's +try something else. + +AUDIENCE: OK. + +PROFESSOR: So the +execution of this pauses. + +What happens? + +So we're looping +somewhere, we got a yield. + +We stop, what's the +first thing we do? + +AUDIENCE: Spit out e. + +PROFESSOR: So you're saying +you return e from this guy? + +AUDIENCE: [INAUDIBLE] +out e [INAUDIBLE] + +PROFESSOR: So I want +to return something-- + +I want to return +something else from this. + +So I want to use this as +if it was a list, yes? + +AUDIENCE: We store e somewhere. + +PROFESSOR: OK, +store e somewhere. + +AUDIENCE: Do you return +the pointer of e? + +PROFESSOR: Almost, so +there's a word for the object + +that I'm returning. + +So I want to use it +as if it was a list. + +So I want to pretend that I had +returned list in this method, + +right? + +So what's the closest thing +to a list that I can return. + +AUDIENCE: An iterator. + +PROFESSOR: An iterator, +thank you, all right. + +So we will grab some +information from here. + +We'll put it in a nice box. + +And that box will +behave like an iterator. + +OK, so the first thing, +someone said put e away, + +so that's when we call next +we're going to spit that out. + +What else do I need to put away? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yep, so +this is a lot of magic. + +This tiny box actually +has a lot of magic in it. + +Because when I call +next, I want to get e. + +But I want to come back +here and keep going, right? + +So I have my code that's +using the iterator. + +And there's this code +here, that's sort of + +in a frozen state. + +Did you guys see any movies +where people are frozen up + +and then, in the +future, they're unfrozen + +and they start moving again? + +AUDIENCE: [INAUDIBLE] movies. + +PROFESSOR: All right, cool. + +So this is like that, this +takes up the whole function, + +freezes it up and +puts it in a box here. + +And it returns an iterator that +can use the box in the future. + +So when you call +next, it gives e, + +which is the guy +that you put in here. + +And then it take the +function out of the box, + +unfreezes it, and +lets it run again + +until it hits yield again. + +Then what happens the +next time it hits yield? + +So, you're looping, and +you're yielding again. + +And say this time +you're yielding. + +AUDIENCE: Just do +the same thing? + +AUDIENCE: Do you put +it in that iterator? + +Or do you make another iterator? + +PROFESSOR: Same iterator. + +So while this is +looping, the code outside + +should get the values +that it's yielding. + +So this has to behave +as one iterator. + +So the code is +unfrozen, it's allowed + +to execute until it +says yield again. + +And then it says yield +with a new element. + +I put this guy in the box. + +Then I return the old guy as +the return value for next. + +AUDIENCE: Oh. + +PROFESSOR: And then +it's frozen again. + +So this guy's still +in a frozen state. + +In the movies, I think +you're only unfrozen once. + +And then you keep going, right? + +And there's a happy ending. + +Where here, every +time you call yield + +you're frozen again, +until someone calls next. + +Does this make sense? + +AUDIENCE: It's kind +of like Groundhog Day. + +PROFESSOR: Yes, except +you're allowed to go forward. + +So this keeps going forward. + +AUDIENCE: --up, thought. + +So it's looping. + +It's the same day, really. + +It's doing different +things, though. + +PROFESSOR: Yeah. + +But all your state is saved. + +So there, some of the +state is rolled back. + +Here all the state is saved. + +AUDIENCE: OK. + +PROFESSOR: OK, but if that +analogy helps, keep it. + +AUDIENCE: When you call +next, are you computing e + +or e prime to be returned? + +PROFESSOR: So when +you're calling next, + +you're computing e +prime and returning e. + +AUDIENCE: So the value you +get from next is pre-computed? + +PROFESSOR: So the value +you get form next is + +what you yielded before. + +AUDIENCE: Wait, so you would +just take some sequence hashes + +instance of that, and then +just by putting in yield, + +now it's magically +become an iterator + +and you can call +that next on it? + +PROFESSOR: Yep. + +And inside, you don't have to +know that it's an iterator. + +So you don't have a +method next here, right? + +I don't implement +next or iter here. + +I write this as if it's +printing stuff to the output. + +You can think of +yield is a print. + +If you wanted an +iterator, then pretend + +you're printing what you +want to iterate over. + +And instead of saying +print you say yield. + +And then you use that. + +OK, now what happens +when we're done? + +What happens when +this loop is done + +and you return from this method? + +We said there's no return value. + +AUDIENCE: It raises a stop? + +PROFESSOR: So when +we return, it's + +going to keep in-- have to +remember that it's done, right? + +And the first time, it +has some element here + +that it has to return. + +So every time you call yield we +put a new element in the box, + +and return the old one. + +So now we would +return the old one. + +We've returned e prime, take it +out, and put done in the box. + +So in the future, if +next is called again, + +raise stop iteration. + +No more freezing, unfreezing, +because we're done. + +We're returned. + +AUDIENCE: So if you called next +it would just give you nothing? + +PROFESSOR: It has to +raise this exception. + +AUDIENCE: So you mean, +like-- oh, so it-- oh, I see. + +It would give you red text then? + +PROFESSOR: If you +called it directly, yes, + +it would give you red text. + +Yes? + +AUDIENCE: So this takes +a sequence or a list, + +not another iterator, ever? + +PROFESSOR: This? + +What's this? + +This other code here? + +AUDIENCE: Yeah. + +PROFESSOR: Not necessarily. + +AUDIENCE: Or you could +give it a procedure. + +PROFESSOR: I can +give it an iterator + +if I'm iterating +over it using for-in. + +AUDIENCE: Like, for something +in one iterator, yield + +that something, and +then [INAUDIBLE] + +AUDIENCE: Oh, OK. + +PROFESSOR: Yeah, +that's a good point. + +I'll get to that +later, when we talk + +about how we're going +to solve the PSET. + +No, we're not solving +the PSET for you. + +But we'll talk about +it a little bit. + +But yeah, that's a good point. + +So there's no +reason why you can't + +have an argument here that, +either a list or an iterator, + +and then you're +iterating over it. + +And then you have +nested generators. + +So you have generators +returned in other generators, + +and you have a whole +chain of things + +happening when you say next. + +AUDIENCE: Wait, so this +is a generator then, + +because it produces-- well +it is an iterator though? + +PROFESSOR: So a generator +returns an iterator + +from this method. + +So a generator acts +like an iterator, + +except when you call next, +it unfreezes this code here, + +and it let's it run. + +AUDIENCE: But I mean, it's +basically an iterator then? + +PROFESSOR: Yeah. + +AUDIENCE: But we're just +calling it a generator because-- + +PROFESSOR: Because +there's a lot more magic. + +AUDIENCE: OK. + +PROFESSOR: So an iterator +just says next and iter. + +This is all that an +iterator is, nothing more. + +Any object that has these +two methods is an iterator. + +AUDIENCE: Oh, OK. + +PROFESSOR: Now a generator +is a piece of Python magic + +that let's you write +shorter iterators. + +So three lines, as +opposed to 13 lines. + +And we came up +with a way to turn + +in a code that +would build a list, + +and easily turn it into a +code that uses a generator, + +and that uses constant memory +instead of building that list. + +AUDIENCE: OK, now I know +how an iterator functions. + +PROFESSOR: Exactly. + +OK, do generators +make sense now? + +Yes. + +AUDIENCE: If you wanted +to loop through all + +of the values in a +generator, do you just + +wait until the +exception's raised? + +Or should you, like, keep +track of how many things + +are going to be +in that generator? + +PROFESSOR: So, when +you have a generator, + +you'd have no idea how +many things there are. + +That's a good point. + +So you're wondering if I have +an iterator, say any iterator, + +not necessarily a generator, how +do I know how many things it's + +going to return, right? + +Do I have ln? + +I do not have ln. + +So an iterator does not have ln. + +So you have to +iterate through it. + +And most importantly, some +iterators can never return. + +So you can have an iterator +that streams data for you + +across the network. + +Or you can have an iterator +that iterates over the Fibonacci + +numbers. + +That's an infinite +sequence, right? + +It's never going to end. + +So ln would not even +be defined then. + +Good question, I like it. + +AUDIENCE: Is there an is-next +method for either iterators + +or generators? + +PROFESSOR: Nope. + +This is what you get, +if there is no in. + +AUDIENCE: If that +is mature then-- + +PROFESSOR: Yeah. + +So in Java you have +this belief that you + +shouldn't get exceptions. + +You should be able to +check for them, right? + +So maybe that's +why you're asking. + +So if people coming from Java +know that any time a method + +raises an exception, +there should + +be another method that tells +you whether this first method is + +going to raise an +exception or not. + +In Python the exception +is just raised. + +So exceptions are not +a lot more expensive + +than regular instructions, +because we're + +using an interpreted +language, and it's already + +reasonably slow. + +So it can do exceptions +for free, yay. + +So this is how it works. + +This is how for-in works. + +Every time you do a for-in, +an exception is raised. + +AUDIENCE: We don't have +to catch that, then? + +PROFESSOR: Nope, the +for-in catches it for you. + +AUDIENCE: That's tricky stuff. + +PROFESSOR: But it's +nice because then you + +can build any iterator +that acts like a list. + +And then you can do +even more fancy stuff, + +and build a generator. + +And you're using constant memory +instead of order and memory + +for producing an +order and size list. + +Yes? + +AUDIENCE: So if we get +passed in an iterator + +and then just yielded +what we passed in, yielded + +the iterator, would +that just, essentially, + +delay everything by one? + +PROFESSOR: So you're yielding +the iterator as next, right? + +AUDIENCE: What? + +Yeah. + +PROFESSOR: You want to +yield the iterator as next. + +Because if you yield +the iterator object, + +you're going to return +that object every time. + +So you're thinking +of something that-- + +AUDIENCE: So you +need to increase-- + +PROFESSOR: You'll +yield up next, right? + +AUDIENCE: Right. + +PROFESSOR: You can have a method +that says this is the method. + +And then you take +in an iterator. + +And then you yield it up next. + +But then you'll, basically, +get the same thing. + +AUDIENCE: The same thing. + +But is it delayed by one or no? + +PROFESSOR: Nope. + +No, so you have to +work through this + +to convince yourself +that it's not delayed. + +So if it would be +delayed by one, + +what's the first thing +that you're yielding. + +AUDIENCE: I don't know. + +PROFESSOR: Yeah, so no delay. + +AUDIENCE: OK. + +PROFESSOR: OK, cool. + +So let's see, what do +we have to implement + +in DNA seq, sub-sequence hashes. + +Do people have an idea of +how to implement that now? + +Yes? + +Does it make sense for everyone? + +So you build it as if +you were building a list, + +and then you use +yield to make it fast. + +And by fast I mean less memory. + +OK, how about interval +sub-sequence hashes? + +The one below. + +AUDIENCE: Is that just +like rolling hash, + +except you, like, have +a step in your range? + +PROFESSOR: OK, so it's like +having a step in your range. + +So how can you do that? + +What's one way of doing it? + +AUDIENCE: [INAUDIBLE] hashes? + +PROFESSOR: Did anyone +solve the PSET yet? + +Yes, OK how did you guys do it? + +Wait, no. + +That's a bad question because +you guys can answer too much. + +So interval sub-sequence hashes +versus sub-sequence hashes. + +Did you copy paste the code? + +AUDIENCE: Absolutely. + +PROFESSOR: OK, so one +way of doing it is copy + +and pasting the code. + +The problem if you copy +paste the code is then you're + +not DRY. + +There's this engineering +thing-- DRY means do not + +repeat yourself. + +So if you're not DRY, +if you copy paste, + +then suppose you +find the bug later. + +Suppose you run the big test +and it crashes somewhere. + +And you fix a bug in +sub-sequence hashes. + +AUDIENCE: Oh, we're +supposed to, like, + +call sub-sequence hashes from +interval sub-sequence hashes, + +right? + +PROFESSOR: That's another +way of doing it that is DRY. + +So this way you're not +copy pasting the code. + +AUDIENCE: We're +inlining the code. + +PROFESSOR: You're inlining +it manually, right? + +All right. + +So the problem, if you +do this on a large scale, + +like when you go +work somewhere, is + +that you end up with 20 +copies of the same code. + +And then five of them have +bug fixes and the other 15 + +don't, because people +forgot where they are. + +So ideally, try to +keep your code DRY. + +AUDIENCE: So, basically, +a list of tuples, right? + +PROFESSOR: OK, so +a list of tuples. + +What does a tuple have? + +AUDIENCE: The index at which +the sub-sequence operates? + +PROFESSOR: So two +indexes, right? + +The index in the first +sub-sequence, say-- + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: OK, say i1 and then +the index in a second sequence, + +for the same +sub-sequence, r right? + +And then i1, i2 prime, i1, i2 +second, so on and so forth. + +So you have the +same sub-sequence + +in the first sequence matches +more things in the second one. + +This is how you're +supposed to return them. + +AUDIENCE: Does the order matter? + +PROFESSOR: I hope not. + +OK, any questions on this? + +We went through generators fast. + +You guys are smart. + +Yes? + +AUDIENCE: Can you explain +how the imaging works? + +Like, how they create the +[INAUDIBLE] on tuples. + +PROFESSOR: No. + +[LAUGHTER] + +PROFESSOR: Sorry, I do not know. + +AUDIENCE: Wait, which part? + +AUDIENCE: So we +yield the tuples. + +But I don't really get how they +come up with the image from it. + +AUDIENCE: From the tuples? + +Oh, I mean, I guess +they're probably values. + +AUDIENCE: Yeah, +because I thought + +if you compared two strings of +DNA that had the exact same, + +I thought it would be +like a diagonal line down, + +not just a small black box. + +PROFESSOR: OK. + +AUDIENCE: So I don't +think I'm understanding + +how they, like, image it. + +PROFESSOR: So you're +supposed to get-- + +your image has some +things here, and a match + +is going to give you a +big diagonal line that's + +stronger than +everything else, right? + +AUDIENCE: It's +really fanned out. + +PROFESSOR: Well I +don't have thin chalk. + +AUDIENCE: No, no, there's like +one really dark black box, + +that's like really black. + +So I thought that meant that +all the tuples are there, + +and everything else +is just kind of gray. + +PROFESSOR: Good question. + +I will have to +think about that-- + +AUDIENCE: --supposed +to be there. + +Is it like a +notation thing, or-- + +PROFESSOR: I think that black +box is supposed to be there. + +Did anyone try comparing +two things that + +shouldn't match, like +the dog and the monkey? + +AUDIENCE: Yeah. + +And the entire +thing was like dark. + +PROFESSOR: Yeah. + +AUDIENCE: --against, like, +two same DNAs everything + +was very light. + +And there was like a very, +very light gray line. + +But I thought that +would be like black. + +PROFESSOR: So I think +how black it is means + +relative to all the +sub-sequences, how long it is-- + +how long the sub-sequence +you're recording is. + +Either that or how many. + +There is a function +somewhere in there + +that computes the intensity +of a pixel, that's + +square root of order +4 of something. + +OK, and I can look at +that now and tell you. + +AUDIENCE: It's OK. + +It's not super important. + +PROFESSOR: Or we can talk about +amortized analysis for a bit. + +Yay! + +Let's talk about +amortized analysis. + +So this is what you're supposed +to get, that's what matters. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: OK, so +amortized analysis, + +what's the example that +we talked about in class? + +AUDIENCE: It's like +list expansion? + +PROFESSOR: OK, so you +have-- you have a list. + +And we know that the list is +stored as an array, right? + +So this means that you can +do indexing in constant time. + +So if you want to get the +first element, order 1. + +If you want to get the +millionth element, order 1. + +This is not true if you +had a link list instead. + +The millionth element +would be order a million. + +So this is an array. + +What do we implement? + +What's the operation that +we implement on this list? + +AUDIENCE: Insert-- + +PROFESSOR: Insert, append, push. + +Let's go for append, because +that's what Python calls it. + +OK, so append puts an element +at the end of the list, right? + +So how does append work? + +AUDIENCE: The array is not full. + +PROFESSOR: OK. + +So say I have some +count variable here. + +So if the length of the +array is bigger than count + +then what do I do? + +AUDIENCE: Then we +can directly insert. + +And because we're +looking up in an array + +and we're doing constant time. + +PROFESSOR: OK. + +AUDIENCE: And so an order +amount of information + +in x [INAUDIBLE]? + +PROFESSOR: Sorry? + +AUDIENCE: Order amount of +information of x [INAUDIBLE]? + +Or do we just-- + +PROFESSOR: Let's say +this is our reference, + +so it's constant time. + +AUDIENCE: Otherwise we don't +have enough room in our array. + +So we need to make it bigger. + +PROFESSOR: OK. + +So we have array 2 +becomes new array + +of size 2 times count, right? + +Copy everything from-- + +AUDIENCE: --length of the array. + +I guess they're the same. + +PROFESSOR: I hope +they're the same. + +AUDIENCE: It is. + +PROFESSOR: Yeah, I'd say that. + +So copy from array to-- +let's do this-- to array 2. + +And then array 2 becomes array. + +And then this code +here goes here, right? + +So there's a better way +to write this if statement + +so the code isn't duplicated. + +OK, so if the length is bigger +than how many elements I have, + +if I still have room in +the array, what's the cost? + +What's the running time? + +Constant. + +Oh, let's put it on the left. + +OK, if I have to resize +the array, what's the cost? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: So, if I did an +operations, what then, right? + +N is the size of the array. + +If the only operation +I have is append, + +then I can say n +operations will cause + +the array of grow to size n. + +So n where n is the +number of operations. + +AUDIENCE: You mean, +like, re-adding to the-- + +PROFESSOR: So an operation is +a data structure operation, + +like a query or an update. + +This is my update +and this is my query. + +AUDIENCE: Wait, but like, +it's order n though, because-- + +PROFESSOR: Yeah. + +AUDIENCE: I know, it's order n. + +But because we +have like an array, + +and then you have +to make a new one, + +and you have to move all +those old items over, right? + +PROFESSOR: Yep. + +AUDIENCE: OK. + +But, I mean, sometimes +like, if your actual array, + +if you expand it before-- +like, let's say you notice + +you're getting full and you +decide to like make it bigger + +at that point, is +it still order n, + +as in the number of +elements that are-- + +PROFESSOR: It depends +on how you decide. + +There's a problem on the PSET +that asks you about that. + +So, depends on when +you make the decision + +and how you make the decision, +the answer is either yes, + +you're still +constant time, or no. + +So if you understand the +amortized analysis then + +you can argue of whether +it still holds or not. + +If this breaks +down at any point, + +not going to be constant time. + +Yes? + +AUDIENCE: So the only cost +is really copying everything + +from the old array +to the new array? + +PROFESSOR: Yes. + +AUDIENCE: Actually +allocating that space is-- + +PROFESSOR: We assume +that allocating the space + +is constant time. + +Good question, because you can't +take that for granted, right? + +So we assume that this is +order 1, copying is order n. + +And then the insertion is +order 1, just like before. + +So allocating may +not be constant. + +In real life, +allocating is actually + +logarithmic either of the +size that you're asking for + +or logarithmic of how many +buffers you've allocated. + +And you can make a +constant time allocator. + +But that's lower than a +logarithmic allocator, + +because the constant +factor behind it is so big. + +But even if this +allocation would + +be order n, which +would be terrible, + +it would still +get absorbed here. + +So the overall model works no +matter what the allocation is. + +It's reasonable, from a +theoretical standpoint, + +to say that +allocation is order 1, + +from a theoretical standpoint. + +So this is the real cost +copying the elements. + +And this makes an append +order n worst case. + +So if you look at this +data structure then + +suppose we want to compute +the cost of an append. + +So say we have code +like this, 4, 1, 2, n. + +First we have L +be an empty list. + +Then we want to compute +the cost of this. + +So if we do it without +amortized analysis, + +line by line +analysis, just like we + +learned in the first lecture, +what's the cost of this, + +making a new list constant? + +What's the cost of one append? + +AUDIENCE: Constant. + +PROFESSOR: One append. + +So an append can either +branch here or branch here. + +So what's the cost +of one append? + +AUDIENCE: It would be +showing with an empty list? + +AUDIENCE: Depends. + +PROFESSOR: It depends. + +So worst case. + +We have to look at a worst case. + +So this is line +by line analysis. + +We're going to get +one number for this. + +AUDIENCE: N. + +AUDIENCE: An n. + +PROFESSOR: Yep. + +So in the worst case, +the list will be full. + +And you'll have +to make a new one. + +And then you're going on +this branch of the if, + +so the cost is order n. + +So order n, worst case. + +So the cost of one call +is order n, worst case. + +How many calls do we make? + +So what is the total +cost of this thing? + +AUDIENCE: It's not +actually n squared. + +PROFESSOR: Yes, it's +not actually n squared. + +But if we do line +by line analysis, + +before we learn +amortized analysis, + +all we can say it's +order of n squared. + +And this is correct, it's not +bigger than n squared, right? + +So O is correct. + +But it's not the tight bound. + +So if we had a multiple +choice, and you selected this, + +you wouldn't get the score +because we usually ask you + +what the tightest +bound that you can get. + +OK, so line by line analysis. + +We worked through that +a lot in doc dist. + +Doesn't work all the time. + +When it doesn't +work, we tell you + +to use amortized +analysis instead. + +So what's the goal of +amortized analysis? + +What do we want? + +You guys are yelling at me that +this is not n squared, why? + +I mean not why, what? + +What is it instead? + +What do we want from +amortized analysis? + +AUDIENCE: [INAUDIBLE] + +AUDIENCE: It's a +[INAUDIBLE] that's an n. + +PROFESSOR: So we want +amortized analysis + +to say that this is order +1 amortized, and this is-- + +[ALARM SOUNDING] + +PROFESSOR: Am I out of time? + +Yeah. + +OK, so there's a difference +between the worst + +case and amortized, right? + +We can argue that this +is order 1 amortized. + +And if this is +order 1 amortized, + +then this is order n amortized. + +So does the difference between +worst case and amortized + +make sense now? + +So this is what I want, +the rest is fancy math. + +If you forget the +fancy math after you're + +done with this class, that's OK. + +If you remember that this +is order 1 amortized, + +and that's order n +amortized, that's good. + +That's all you need +to know to write code + +if you don't design algorithms. + +So this is an important piece +of knowledge on its own. + +OK, so questions about the +difference between worst case + +and amortized? + +OK, what does amortized mean? + +AUDIENCE: Average. + +PROFESSOR: Yep, averaged out +over multiple operations. + +So instead of doing +line by line analysis, + +we have to look at what happens +over multiple operations, + +right? + +So there are two methods that +I think are useful in CLRS. + +There are three in +total, but the last one + +is horribly complicated. + +So there's something +called aggregate analysis. + +And there's something called +the cost based accounting. + +So last time when we looked +at the costs for append, + +we argued that, hey, it's +order 1 for a lot of times. + +And then it's only +order n for an operation + +that's a power of 2. + +So if we're looking +at the K-ith append, + +then this is order K +for K equals 2 to the i. + +And it's order 1 otherwise. + +Right? + +So if we sum up +all these costs, we + +get-- plus sum over log +n of O of 2 to the i. + +And this is clearly order n. + +And if you do the math +here, this is also order n. + +So this is aggregate analysis. + +This is what we +taught you in lecture. + +Does this make sense? + +So the key here is that whenever +we are increasing the array, + +we're increasing it to 2 times. + +And we start with a +size of 1, count is 1. + +We start with an +array with 1 element. + +So the size of the +array will first + +be 1, then 2, then 4, then +8, then 16, 32, 64, 128, + +so on so forth. + +It increases exponentially. + +So on the first append +I'll have to do a resize. + +On the second one, resize. + +Fourth one, resize. + +Eighth, resize, so +on and so forth. + +So if I'm adding up the +cost for n operations, + +each operation is +order 1 because I'm + +inserting everywhere. + +And then all these +operations are all order n. + +But there's few of them. + +They're few and far out. + +So if you write the sum this +way, and you do the math, + +you get that it's order n. + +So aggregate analysis +says, look at n operations + +and add the costs up together. + +And last time we had that good +example of walking over a tree, + +and in order traversal where +we drew arrows across edges. + +So that's aggregate analysis. + +And then you should look +at the cost method in CLRS + +because that's also +useful sometimes. + +Does this help? + +Any questions? + +No, everyone wants to go home. + +AUDIENCE: Wait-- + +PROFESSOR: Almost. + +AUDIENCE: For log n, so you're +starting from log n going to-- + +PROFESSOR: So I'm starting +from 1 going to log n. + +AUDIENCE: Oh, oh, so [INAUDIBLE] +after you're buffering. + +PROFESSOR: So this is +fancy math for saying only + +add up powers of two. + +So that's what I'm trying +to say, add these guys up. + +AUDIENCE: Well that's +your step [INAUDIBLE]. + +PROFESSOR: Yeah. + +AUDIENCE: Oh, OK. + +Oh, I like that. + +OK. + +PROFESSOR: OK. \ No newline at end of file diff --git a/-FHm2pQmiSM.txt b/-FHm2pQmiSM.txt new file mode 100644 index 0000000000000000000000000000000000000000..5492034c7291460c0418589cea7dc82850b7877e --- /dev/null +++ b/-FHm2pQmiSM.txt @@ -0,0 +1,8154 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu everybody would like to + + align:start position:0% +ocw.mit.edu everybody would like to + + + align:start position:0% +ocw.mit.edu everybody would like to +believe that they just simply sort of + + align:start position:0% +believe that they just simply sort of + + + align:start position:0% +believe that they just simply sort of +think about the subject a little bit and + + align:start position:0% +think about the subject a little bit and + + + align:start position:0% +think about the subject a little bit and +it'll come to them it's kind of like the + + align:start position:0% +it'll come to them it's kind of like the + + + align:start position:0% +it'll come to them it's kind of like the +osmosis theory of learning but in fact + + align:start position:0% +osmosis theory of learning but in fact + + + align:start position:0% +osmosis theory of learning but in fact +the way you get good at something is + + align:start position:0% +the way you get good at something is + + + align:start position:0% +the way you get good at something is +practicing it's the same for music it's + + align:start position:0% +practicing it's the same for music it's + + + align:start position:0% +practicing it's the same for music it's +the same for sports it's the same for + + align:start position:0% +the same for sports it's the same for + + + align:start position:0% +the same for sports it's the same for +academics so the way you get good in + + align:start position:0% +academics so the way you get good in + + + align:start position:0% +academics so the way you get good in +this subject is to work on the homework + + align:start position:0% +this subject is to work on the homework + + + align:start position:0% +this subject is to work on the homework +we'll give two kinds of + + align:start position:0% +we'll give two kinds of + + + align:start position:0% +we'll give two kinds of +homework there will be conventional + + align:start position:0% +homework there will be conventional + + + align:start position:0% +homework there will be conventional +kinds of problems followed by + + align:start position:0% +kinds of problems followed by + + + align:start position:0% +kinds of problems followed by +engineering design + + align:start position:0% +engineering design + + + align:start position:0% +engineering design +problems the conventional kinds of + + align:start position:0% +problems the conventional kinds of + + + align:start position:0% +problems the conventional kinds of +problems are intended to be the kinds of + + align:start position:0% +problems are intended to be the kinds of + + + align:start position:0% +problems are intended to be the kinds of +problems + + align:start position:0% +problems + + + align:start position:0% +problems +that have simple + + align:start position:0% +that have simple + + + align:start position:0% +that have simple +unambiguous easily checkable + + align:start position:0% +unambiguous easily checkable + + + align:start position:0% +unambiguous easily checkable +answers so well-defined problem single + + align:start position:0% +answers so well-defined problem single + + + align:start position:0% +answers so well-defined problem single +unambiguous + + align:start position:0% +unambiguous + + + align:start position:0% +unambiguous +answer uh the kinds of problems that you + + align:start position:0% +answer uh the kinds of problems that you + + + align:start position:0% +answer uh the kinds of problems that you +might be expecting to see on an exam for + + align:start position:0% +might be expecting to see on an exam for + + + align:start position:0% +might be expecting to see on an exam for +example but then we'll also have uh + + align:start position:0% +example but then we'll also have uh + + + align:start position:0% +example but then we'll also have uh +engineering design problems engineering + + align:start position:0% +engineering design problems engineering + + + align:start position:0% +engineering design problems engineering +design problems are intended to + + align:start position:0% +design problems are intended to + + + align:start position:0% +design problems are intended to +be a little more ambitious a little more + + align:start position:0% +be a little more ambitious a little more + + + align:start position:0% +be a little more ambitious a little more +fun a little harder + + align:start position:0% +fun a little harder + + + align:start position:0% +fun a little harder +Perhaps Perhaps not completely well + + align:start position:0% +Perhaps Perhaps not completely well + + + align:start position:0% +Perhaps Perhaps not completely well +specified sort of more like the kind of + + align:start position:0% +specified sort of more like the kind of + + + align:start position:0% +specified sort of more like the kind of +a problem that your boss might give you + + align:start position:0% +a problem that your boss might give you + + + align:start position:0% +a problem that your boss might give you +after you've + + align:start position:0% +after you've + + + align:start position:0% +after you've +graduated so part of the exercise will + + align:start position:0% +graduated so part of the exercise will + + + align:start position:0% +graduated so part of the exercise will +be figuring out exactly how to convince + + align:start position:0% +be figuring out exactly how to convince + + + align:start position:0% +be figuring out exactly how to convince +somebody that you got the right answer + + align:start position:0% +somebody that you got the right answer + + + align:start position:0% +somebody that you got the right answer +so those kinds of problems are often the + + align:start position:0% +so those kinds of problems are often the + + + align:start position:0% +so those kinds of problems are often the +it will often be the case that numerics + + align:start position:0% +it will often be the case that numerics + + + align:start position:0% +it will often be the case that numerics +will help you in making an + + align:start position:0% +will help you in making an + + + align:start position:0% +will help you in making an +argument so it's often will be the case + + align:start position:0% +argument so it's often will be the case + + + align:start position:0% +argument so it's often will be the case +that we'll ask you to plot something or + + align:start position:0% +that we'll ask you to plot something or + + + align:start position:0% +that we'll ask you to plot something or +maybe you just decide that a plot is the + + align:start position:0% +maybe you just decide that a plot is the + + + align:start position:0% +maybe you just decide that a plot is the +most effective way to communicate your + + align:start position:0% +most effective way to communicate your + + + align:start position:0% +most effective way to communicate your +result we are completely Ambi ambivalent + + align:start position:0% +result we are completely Ambi ambivalent + + + align:start position:0% +result we are completely Ambi ambivalent +about what programming language we that + + align:start position:0% +about what programming language we that + + + align:start position:0% +about what programming language we that +you use since uh 601 and 602 are + + align:start position:0% +you use since uh 601 and 602 are + + + align:start position:0% +you use since uh 601 and 602 are +prerequisites we assume you all know + + align:start position:0% +prerequisites we assume you all know + + + align:start position:0% +prerequisites we assume you all know +python so all the examples that I give + + align:start position:0% +python so all the examples that I give + + + align:start position:0% +python so all the examples that I give +in lecture handouts or in homework + + align:start position:0% +in lecture handouts or in homework + + + align:start position:0% +in lecture handouts or in homework +solutions will be in Python but if you'd + + align:start position:0% +solutions will be in Python but if you'd + + + align:start position:0% +solutions will be in Python but if you'd +rather use mat lab I just don't care + + align:start position:0% +rather use mat lab I just don't care + + + align:start position:0% +rather use mat lab I just don't care +okay we're completely ambivalent about + + align:start position:0% +okay we're completely ambivalent about + + + align:start position:0% +okay we're completely ambivalent about +what programming language you use but it + + align:start position:0% +what programming language you use but it + + + align:start position:0% +what programming language you use but it +will be important that in some of the + + align:start position:0% +will be important that in some of the + + + align:start position:0% +will be important that in some of the +problems you'll find that useful to be + + align:start position:0% +problems you'll find that useful to be + + + align:start position:0% +problems you'll find that useful to be +able to to um generate a numerical kind + + align:start position:0% +able to to um generate a numerical kind + + + align:start position:0% +able to to um generate a numerical kind +of + + align:start position:0% +of + + + align:start position:0% +of +solution these are very different kinds + + align:start position:0% +solution these are very different kinds + + + align:start position:0% +solution these are very different kinds +of problems and to help you with both of + + align:start position:0% +of problems and to help you with both of + + + align:start position:0% +of problems and to help you with both of +them we have a different idea about + + align:start position:0% +them we have a different idea about + + + align:start position:0% +them we have a different idea about +each so to help you with the + + align:start position:0% +each so to help you with the + + + align:start position:0% +each so to help you with the +conventional problems the kind that have + + align:start position:0% +conventional problems the kind that have + + + align:start position:0% +conventional problems the kind that have +precise + + align:start position:0% +precise + + + align:start position:0% +precise +easy to Che answers we've developed for + + align:start position:0% +easy to Che answers we've developed for + + + align:start position:0% +easy to Che answers we've developed for +the first time ever over the summer a + + align:start position:0% +the first time ever over the summer a + + + align:start position:0% +the first time ever over the summer a +tutor type environment for + + align:start position:0% +tutor type environment for + + + align:start position:0% +tutor type environment for +63 so this was intended to be like the + + align:start position:0% +63 so this was intended to be like the + + + align:start position:0% +63 so this was intended to be like the +tutor environment that we use in 601 + + align:start position:0% +tutor environment that we use in 601 + + + align:start position:0% +tutor environment that we use in 601 +it's one of the more popular aspects of + + align:start position:0% +it's one of the more popular aspects of + + + align:start position:0% +it's one of the more popular aspects of +61 the fact that you can put in an + + align:start position:0% +61 the fact that you can put in an + + + align:start position:0% +61 the fact that you can put in an +answer and hit the button that says + + align:start position:0% +answer and hit the button that says + + + align:start position:0% +answer and hit the button that says +check okay so we're going to have one of + + align:start position:0% +check okay so we're going to have one of + + + align:start position:0% +check okay so we're going to have one of +those so the idea is going to be that in + + align:start position:0% +those so the idea is going to be that in + + + align:start position:0% +those so the idea is going to be that in +the case that we ask you a simple + + align:start position:0% +the case that we ask you a simple + + + align:start position:0% +the case that we ask you a simple +question that has a pre precise answer + + align:start position:0% +question that has a pre precise answer + + + align:start position:0% +question that has a pre precise answer +we'll use a tutor environment to let you + + align:start position:0% +we'll use a tutor environment to let you + + + align:start position:0% +we'll use a tutor environment to let you +check your answer to see if you got the + + align:start position:0% +check your answer to see if you got the + + + align:start position:0% +check your answer to see if you got the +right answer in the case of the + + align:start position:0% +right answer in the case of the + + + align:start position:0% +right answer in the case of the +engineering design problems that won't + + align:start position:0% +engineering design problems that won't + + + align:start position:0% +engineering design problems that won't +be the case it will not be the case that + + align:start position:0% +be the case it will not be the case that + + + align:start position:0% +be the case it will not be the case that +it's very easy at all to think about a + + align:start position:0% +it's very easy at all to think about a + + + align:start position:0% +it's very easy at all to think about a +computer program that would check + + align:start position:0% +computer program that would check + + + align:start position:0% +computer program that would check +you so the alternative is going to be + + align:start position:0% +you so the alternative is going to be + + + align:start position:0% +you so the alternative is going to be +that we will have extended office + + align:start position:0% +that we will have extended office + + + align:start position:0% +that we will have extended office +hours so we're going to have something + + align:start position:0% +hours so we're going to have something + + + align:start position:0% +hours so we're going to have something +that I think of as open or Block office + + align:start position:0% +that I think of as open or Block office + + + align:start position:0% +that I think of as open or Block office +hours Monday and Tuesday afternoon and + + align:start position:0% +hours Monday and Tuesday afternoon and + + + align:start position:0% +hours Monday and Tuesday afternoon and +early evening we've reserved the + + align:start position:0% +early evening we've reserved the + + + align:start position:0% +early evening we've reserved the +basement of sta + + align:start position:0% +basement of sta + + + align:start position:0% +basement of sta +32044 for use of this class the idea + + align:start position:0% +32044 for use of this class the idea + + + align:start position:0% +32044 for use of this class the idea +being that that's a nice space you can + + align:start position:0% +being that that's a nice space you can + + + align:start position:0% +being that that's a nice space you can +just come there to work anytime you want + + align:start position:0% +just come there to work anytime you want + + + align:start position:0% +just come there to work anytime you want +to hopefully because it's + + align:start position:0% +to hopefully because it's + + + align:start position:0% +to hopefully because it's +nice and hopefully because you all know + + align:start position:0% +nice and hopefully because you all know + + + align:start position:0% +nice and hopefully because you all know +that there will be other 63 people there + + align:start position:0% +that there will be other 63 people there + + + align:start position:0% +that there will be other 63 people there +you'll just decide that's a good place + + align:start position:0% +you'll just decide that's a good place + + + align:start position:0% +you'll just decide that's a good place +to work and that's convenient because in + + align:start position:0% +to work and that's convenient because in + + + align:start position:0% +to work and that's convenient because in +these engineering design problems if you + + align:start position:0% +these engineering design problems if you + + + align:start position:0% +these engineering design problems if you +run into something that's unclear to you + + align:start position:0% +run into something that's unclear to you + + + align:start position:0% +run into something that's unclear to you +we don't really want you to spend an + + align:start position:0% +we don't really want you to spend an + + + align:start position:0% +we don't really want you to spend an +hour pondering what was being + + align:start position:0% +hour pondering what was being + + + align:start position:0% +hour pondering what was being +asked so we want to make it easy for you + + align:start position:0% +asked so we want to make it easy for you + + + align:start position:0% +asked so we want to make it easy for you +to get + + align:start position:0% +to get + + + align:start position:0% +to get +help and you can get help from peers + + align:start position:0% +help and you can get help from peers + + + align:start position:0% +help and you can get help from peers +from other students who are there but + + align:start position:0% +from other students who are there but + + + align:start position:0% +from other students who are there but +we'll also make sure that there's at + + align:start position:0% +we'll also make sure that there's at + + + align:start position:0% +we'll also make sure that there's at +least one six3 staff member there all + + align:start position:0% +least one six3 staff member there all + + + align:start position:0% +least one six3 staff member there all +the + + align:start position:0% +the + + + align:start position:0% +the +time okay so the homeworks will be due + + align:start position:0% +time okay so the homeworks will be due + + + align:start position:0% +time okay so the homeworks will be due +on Wednesday that's the Strategic value + + align:start position:0% +on Wednesday that's the Strategic value + + + align:start position:0% +on Wednesday that's the Strategic value +of Mondays and Tuesdays so that you can + + align:start position:0% +of Mondays and Tuesdays so that you can + + + align:start position:0% +of Mondays and Tuesdays so that you can +uh use that time to get ready for + + align:start position:0% +uh use that time to get ready for + + + align:start position:0% +uh use that time to get ready for +turning in the homework on Wednesday + + align:start position:0% +turning in the homework on Wednesday + + + align:start position:0% +turning in the homework on Wednesday +questions or + + align:start position:0% + + + + align:start position:0% + +comments okay we're required to say + + align:start position:0% +comments okay we're required to say + + + align:start position:0% +comments okay we're required to say +something about what we mean by a + + align:start position:0% +something about what we mean by a + + + align:start position:0% +something about what we mean by a +collaboration policy so in this course + + align:start position:0% +collaboration policy so in this course + + + align:start position:0% +collaboration policy so in this course +we would like you to talk to each other + + align:start position:0% +we would like you to talk to each other + + + align:start position:0% +we would like you to talk to each other +and help each other figure out what's + + align:start position:0% +and help each other figure out what's + + + align:start position:0% +and help each other figure out what's +going + + align:start position:0% + + + + align:start position:0% + +on at the same time we'd like to reward + + align:start position:0% +on at the same time we'd like to reward + + + align:start position:0% +on at the same time we'd like to reward +you for being on the honest Side by + + align:start position:0% +you for being on the honest Side by + + + align:start position:0% +you for being on the honest Side by +which I'm going to mean if you sign your + + align:start position:0% +which I'm going to mean if you sign your + + + align:start position:0% +which I'm going to mean if you sign your +name to something you actually did it + + align:start position:0% + + + + align:start position:0% + +so we'd like to believe that the + + align:start position:0% +so we'd like to believe that the + + + align:start position:0% +so we'd like to believe that the +homework that you turn in under your + + align:start position:0% +homework that you turn in under your + + + align:start position:0% +homework that you turn in under your +name you + + align:start position:0% +name you + + + align:start position:0% +name you +did you're perfectly welcome to talk to + + align:start position:0% +did you're perfectly welcome to talk to + + + align:start position:0% +did you're perfectly welcome to talk to +each other to talk to the staff to talk + + align:start position:0% +each other to talk to the staff to talk + + + align:start position:0% +each other to talk to the staff to talk +to friends who took this course + + align:start position:0% +to friends who took this course + + + align:start position:0% +to friends who took this course +previously get all the help you like in + + align:start position:0% +previously get all the help you like in + + + align:start position:0% +previously get all the help you like in +trying to understand the concepts but + + align:start position:0% +trying to understand the concepts but + + + align:start position:0% +trying to understand the concepts but +when it comes down to writing up your + + align:start position:0% +when it comes down to writing up your + + + align:start position:0% +when it comes down to writing up your +homework and turning it in we expect + + align:start position:0% +homework and turning it in we expect + + + align:start position:0% +homework and turning it in we expect +that what you signed your name to is + + align:start position:0% +that what you signed your name to is + + + align:start position:0% +that what you signed your name to is +something you did if you got especially + + align:start position:0% +something you did if you got especially + + + align:start position:0% +something you did if you got especially +large amount of help at the conceptual + + align:start position:0% +large amount of help at the conceptual + + + align:start position:0% +large amount of help at the conceptual +level we we'd like you to acknowledge + + align:start position:0% +level we we'd like you to acknowledge + + + align:start position:0% +level we we'd like you to acknowledge +that you don't need to acknowledge that + + align:start position:0% +that you don't need to acknowledge that + + + align:start position:0% +that you don't need to acknowledge that +the ta's helped you we expect that but + + align:start position:0% +the ta's helped you we expect that but + + + align:start position:0% +the ta's helped you we expect that but +if you collaborated with somebody to + + align:start position:0% +if you collaborated with somebody to + + + align:start position:0% +if you collaborated with somebody to +understand what the problem was we'd + + align:start position:0% +understand what the problem was we'd + + + align:start position:0% +understand what the problem was we'd +like you to tell us that just right at + + align:start position:0% +like you to tell us that just right at + + + align:start position:0% +like you to tell us that just right at +the top collaborated on figuring out the + + align:start position:0% +the top collaborated on figuring out the + + + align:start position:0% +the top collaborated on figuring out the +concept with so and + + align:start position:0% +concept with so and + + + align:start position:0% +concept with so and +so but we'd like you to have written + + align:start position:0% +so but we'd like you to have written + + + align:start position:0% +so but we'd like you to have written +your homework so for example we would + + align:start position:0% +your homework so for example we would + + + align:start position:0% +your homework so for example we would +like you not to say I copied so and so's + + align:start position:0% +like you not to say I copied so and so's + + + align:start position:0% +like you not to say I copied so and so's +homework word for word even though + + align:start position:0% +homework word for word even though + + + align:start position:0% +homework word for word even though +that's an honest statement that's not + + align:start position:0% +that's an honest statement that's not + + + align:start position:0% +that's an honest statement that's not +something that we're actually looking + + align:start position:0% +something that we're actually looking + + + align:start position:0% +something that we're actually looking +for okay is that is that clear we want + + align:start position:0% +for okay is that is that clear we want + + + align:start position:0% +for okay is that is that clear we want +you to work together but we would like + + align:start position:0% +you to work together but we would like + + + align:start position:0% +you to work together but we would like +you to write up your own + + align:start position:0% + + + + align:start position:0% + +Solutions okay there's a dead we have + + align:start position:0% +Solutions okay there's a dead we have + + + align:start position:0% +Solutions okay there's a dead we have +firm + + align:start position:0% +firm + + + align:start position:0% +firm +deadlines uh the homeworks will always + + align:start position:0% +deadlines uh the homeworks will always + + + align:start position:0% +deadlines uh the homeworks will always +be do on + + align:start position:0% +be do on + + + align:start position:0% +be do on +Wednesday you'll be able to slip on one + + align:start position:0% +Wednesday you'll be able to slip on one + + + align:start position:0% +Wednesday you'll be able to slip on one +without + + align:start position:0% +without + + + align:start position:0% +without +penalty so if you turn in one late it + + align:start position:0% +penalty so if you turn in one late it + + + align:start position:0% +penalty so if you turn in one late it +won't change it won't have any effect on + + align:start position:0% +won't change it won't have any effect on + + + align:start position:0% +won't change it won't have any effect on +your grade whatever if you do twice that + + align:start position:0% +your grade whatever if you do twice that + + + align:start position:0% +your grade whatever if you do twice that +could have an effect unless you're + + align:start position:0% +could have an effect unless you're + + + align:start position:0% +could have an effect unless you're +excused by a Dean or an instructor or a + + align:start position:0% +excused by a Dean or an instructor or a + + + align:start position:0% +excused by a Dean or an instructor or a +medical + + align:start position:0% +medical + + + align:start position:0% +medical +person uh that submission will count + + align:start position:0% +person uh that submission will count + + + align:start position:0% +person uh that submission will count +half what it would normally + + align:start position:0% +half what it would normally + + + align:start position:0% +half what it would normally +count I should have mentioned when I was + + align:start position:0% +count I should have mentioned when I was + + + align:start position:0% +count I should have mentioned when I was +talking about homework homework one is + + align:start position:0% +talking about homework homework one is + + + align:start position:0% +talking about homework homework one is +already posted it will be due next + + align:start position:0% + + + + align:start position:0% + +Wednesday uh the online submission part + + align:start position:0% +Wednesday uh the online submission part + + + align:start position:0% +Wednesday uh the online submission part +is almost ready to be posted and will be + + align:start position:0% +is almost ready to be posted and will be + + + align:start position:0% +is almost ready to be posted and will be +posted later this afternoon so right now + + align:start position:0% +posted later this afternoon so right now + + + align:start position:0% +posted later this afternoon so right now +you can see all the problems but the + + align:start position:0% +you can see all the problems but the + + + align:start position:0% +you can see all the problems but the +online will become available this + + align:start position:0% + + + + align:start position:0% + +afternoon okay here's uh3 at a + + align:start position:0% +afternoon okay here's uh3 at a + + + align:start position:0% +afternoon okay here's uh3 at a +glance it's not too unlike what you + + align:start position:0% +glance it's not too unlike what you + + + align:start position:0% +glance it's not too unlike what you +might have expected just a couple things + + align:start position:0% +might have expected just a couple things + + + align:start position:0% +might have expected just a couple things +to point out the order of coverage is + + align:start position:0% +to point out the order of coverage is + + + align:start position:0% +to point out the order of coverage is +not the same as the order of coverage in + + align:start position:0% +not the same as the order of coverage in + + + align:start position:0% +not the same as the order of coverage in +oppenheim and + + align:start position:0% +oppenheim and + + + align:start position:0% +oppenheim and +wiski the reason for doing that is that + + align:start position:0% +wiski the reason for doing that is that + + + align:start position:0% +wiski the reason for doing that is that +having taught this class for 15 years + + align:start position:0% +having taught this class for 15 years + + + align:start position:0% +having taught this class for 15 years +years I just think there's some subjects + + align:start position:0% +years I just think there's some subjects + + + align:start position:0% +years I just think there's some subjects +that are easier starting + + align:start position:0% +that are easier starting + + + align:start position:0% +that are easier starting +points than + + align:start position:0% +points than + + + align:start position:0% +points than +others so I'm doing what I think is the + + align:start position:0% +others so I'm doing what I think is the + + + align:start position:0% +others so I'm doing what I think is the +easiest entry to this + + align:start position:0% +easiest entry to this + + + align:start position:0% +easiest entry to this +material with the idea that after you've + + align:start position:0% +material with the idea that after you've + + + align:start position:0% +material with the idea that after you've +got the easy stuff under your belt it's + + align:start position:0% +got the easy stuff under your belt it's + + + align:start position:0% +got the easy stuff under your belt it's +easier to move on to the more difficult + + align:start position:0% +easier to move on to the more difficult + + + align:start position:0% +easier to move on to the more difficult +material so the order is not precisely + + align:start position:0% +material so the order is not precisely + + + align:start position:0% +material so the order is not precisely +the same as that in oppenheim and wilski + + align:start position:0% +the same as that in oppenheim and wilski + + + align:start position:0% +the same as that in oppenheim and wilski +but there is a map on the website that + + align:start position:0% +but there is a map on the website that + + + align:start position:0% +but there is a map on the website that +gives you a week-by-week + + align:start position:0% +gives you a week-by-week + + + align:start position:0% +gives you a week-by-week +breakdown of what part of oppenheim and + + align:start position:0% +breakdown of what part of oppenheim and + + + align:start position:0% +breakdown of what part of oppenheim and +wil are we working on right + + align:start position:0% +wil are we working on right + + + align:start position:0% +wil are we working on right +now so Oppenheimer wiski is the + + align:start position:0% +now so Oppenheimer wiski is the + + + align:start position:0% +now so Oppenheimer wiski is the +recommended text but it's not quite in + + align:start position:0% +recommended text but it's not quite in + + + align:start position:0% +recommended text but it's not quite in +the regular order of oppenheim and + + align:start position:0% +the regular order of oppenheim and + + + align:start position:0% +the regular order of oppenheim and +wilsky we will eventually cover exactly + + align:start position:0% +wilsky we will eventually cover exactly + + + align:start position:0% +wilsky we will eventually cover exactly +the same material that is in that + + align:start position:0% +the same material that is in that + + + align:start position:0% +the same material that is in that +oppenheim and wilsky was written for + + align:start position:0% +oppenheim and wilsky was written for + + + align:start position:0% +oppenheim and wilsky was written for +this class we'll cover the same material + + align:start position:0% +this class we'll cover the same material + + + align:start position:0% +this class we'll cover the same material +just not quite in the same + + align:start position:0% + + + + align:start position:0% + +order another thing to notice is exams + + align:start position:0% +order another thing to notice is exams + + + align:start position:0% +order another thing to notice is exams +we'll have three midterm + + align:start position:0% +we'll have three midterm + + + align:start position:0% +we'll have three midterm +exams and a final the midterm term exams + + align:start position:0% +exams and a final the midterm term exams + + + align:start position:0% +exams and a final the midterm term exams +are all evening exams 7:30 to 9:30 on + + align:start position:0% +are all evening exams 7:30 to 9:30 on + + + align:start position:0% +are all evening exams 7:30 to 9:30 on +Wednesday + + align:start position:0% + + + + align:start position:0% + +evening the idea is that there's + + align:start position:0% +evening the idea is that there's + + + align:start position:0% +evening the idea is that there's +intended to be a gentle ramp through the + + align:start position:0% +intended to be a gentle ramp through the + + + align:start position:0% +intended to be a gentle ramp through the +exams exam one is worth 10% exam two is + + align:start position:0% +exams exam one is worth 10% exam two is + + + align:start position:0% +exams exam one is worth 10% exam two is +worth 15% exam three is worth 20% the + + align:start position:0% +worth 15% exam three is worth 20% the + + + align:start position:0% +worth 15% exam three is worth 20% the +final exam is worth + + align:start position:0% +final exam is worth + + + align:start position:0% +final exam is worth +40% so the idea is that if you have a + + align:start position:0% +40% so the idea is that if you have a + + + align:start position:0% +40% so the idea is that if you have a +mismatch on the way if you don't quite + + align:start position:0% +mismatch on the way if you don't quite + + + align:start position:0% +mismatch on the way if you don't quite +understand the way we're going to be + + align:start position:0% +understand the way we're going to be + + + align:start position:0% +understand the way we're going to be +asking questions and so forth there's + + align:start position:0% +asking questions and so forth there's + + + align:start position:0% +asking questions and so forth there's +not a big penalty for screwing up the + + align:start position:0% +not a big penalty for screwing up the + + + align:start position:0% +not a big penalty for screwing up the +first exam that's the idea so there's a + + align:start position:0% +first exam that's the idea so there's a + + + align:start position:0% +first exam that's the idea so there's a +intended to be a gentle ramp um in how + + align:start position:0% +intended to be a gentle ramp um in how + + + align:start position:0% +intended to be a gentle ramp um in how +much the exams + + align:start position:0% + + + + align:start position:0% + +count okay and finally I'd like feedback + + align:start position:0% +count okay and finally I'd like feedback + + + align:start position:0% +count okay and finally I'd like feedback +on what you think is happening so I + + align:start position:0% +on what you think is happening so I + + + align:start position:0% +on what you think is happening so I +would like to ask for a few volunteers + + align:start position:0% +would like to ask for a few volunteers + + + align:start position:0% +would like to ask for a few volunteers +few is four or + + align:start position:0% + + + + align:start position:0% + +fewer who would be interested to meet + + align:start position:0% +fewer who would be interested to meet + + + align:start position:0% +fewer who would be interested to meet +with me once a week just to tell me what + + align:start position:0% +with me once a week just to tell me what + + + align:start position:0% +with me once a week just to tell me what +you think + + align:start position:0% +you think + + + align:start position:0% +you think +think ideally those people would be kind + + align:start position:0% +think ideally those people would be kind + + + align:start position:0% +think ideally those people would be kind +of outgoing and tell me things that + + align:start position:0% +of outgoing and tell me things that + + + align:start position:0% +of outgoing and tell me things that +other people think too but if you're + + align:start position:0% +other people think too but if you're + + + align:start position:0% +other people think too but if you're +completely introverted and want to only + + align:start position:0% +completely introverted and want to only + + + align:start position:0% +completely introverted and want to only +tell me what you think that's fine + + align:start position:0% +tell me what you think that's fine + + + align:start position:0% +tell me what you think that's fine +too so uh this is an opportunity for you + + align:start position:0% +too so uh this is an opportunity for you + + + align:start position:0% +too so uh this is an opportunity for you +to tell the staff to give us feedback on + + align:start position:0% +to tell the staff to give us feedback on + + + align:start position:0% +to tell the staff to give us feedback on +how things are going we're going too + + align:start position:0% +how things are going we're going too + + + align:start position:0% +how things are going we're going too +slow we're going too fast we're going + + align:start position:0% +slow we're going too fast we're going + + + align:start position:0% +slow we're going too fast we're going +too boring we're intensely too + + align:start position:0% +too boring we're intensely too + + + align:start position:0% +too boring we're intensely too +interesting that kind of stuff + + align:start position:0% +interesting that kind of stuff + + + align:start position:0% +interesting that kind of stuff +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +and it's a it's an opportunity for you + + align:start position:0% +and it's a it's an opportunity for you + + + align:start position:0% +and it's a it's an opportunity for you +to understand our perspective like well + + align:start position:0% +to understand our perspective like well + + + align:start position:0% +to understand our perspective like well +the reason we did that was blah and then + + align:start position:0% +the reason we did that was blah and then + + + align:start position:0% +the reason we did that was blah and then +you can tell us we but that's not + + align:start position:0% +you can tell us we but that's not + + + align:start position:0% +you can tell us we but that's not +important so it's an opportunity for um + + align:start position:0% +important so it's an opportunity for um + + + align:start position:0% +important so it's an opportunity for um +you to convey to + + align:start position:0% +you to convey to + + + align:start position:0% +you to convey to +us how you think things are going and + + align:start position:0% +us how you think things are going and + + + align:start position:0% +us how you think things are going and +how you think things should be different + + align:start position:0% +how you think things should be different + + + align:start position:0% +how you think things should be different +it's also an opportunity for you to + + align:start position:0% +it's also an opportunity for you to + + + align:start position:0% +it's also an opportunity for you to +learn about teaching so if you think + + align:start position:0% +learn about teaching so if you think + + + align:start position:0% +learn about teaching so if you think +about teaching as a career it's a good + + align:start position:0% +about teaching as a career it's a good + + + align:start position:0% +about teaching as a career it's a good +thing to do completely voluntary has + + align:start position:0% +thing to do completely voluntary has + + + align:start position:0% +thing to do completely voluntary has +absolutely absolutely no effect on your + + align:start position:0% +absolutely absolutely no effect on your + + + align:start position:0% +absolutely absolutely no effect on your +grade uh if you think you might be + + align:start position:0% +grade uh if you think you might be + + + align:start position:0% +grade uh if you think you might be +interested it's probably going to meet + + align:start position:0% +interested it's probably going to meet + + + align:start position:0% +interested it's probably going to meet +on we'll probably meet on Thursday + + align:start position:0% +on we'll probably meet on Thursday + + + align:start position:0% +on we'll probably meet on Thursday +afternoon but that's negotiable since + + align:start position:0% +afternoon but that's negotiable since + + + align:start position:0% +afternoon but that's negotiable since +it's only four people and if you are + + align:start position:0% +it's only four people and if you are + + + align:start position:0% +it's only four people and if you are +interested please send me an email and + + align:start position:0% +interested please send me an email and + + + align:start position:0% +interested please send me an email and +the first four people who ask they're + + align:start position:0% +the first four people who ask they're + + + align:start position:0% +the first four people who ask they're +there + + align:start position:0% + + + + align:start position:0% + +okay that's it on + + align:start position:0% + + + + align:start position:0% + +Administration are there things you'd + + align:start position:0% +Administration are there things you'd + + + align:start position:0% +Administration are there things you'd +like to know about course Administration + + align:start position:0% +like to know about course Administration + + + align:start position:0% +like to know about course Administration +before we go on to technical + + align:start position:0% + + + + align:start position:0% + +things wonderful okay this course is + + align:start position:0% +things wonderful okay this course is + + + align:start position:0% +things wonderful okay this course is +about + + align:start position:0% + + + + align:start position:0% + +systems this is not the first course + + align:start position:0% +systems this is not the first course + + + align:start position:0% +systems this is not the first course +you've had about + + align:start position:0% +you've had about + + + align:start position:0% +you've had about +systems you've had lots of courses in + + align:start position:0% +systems you've had lots of courses in + + + align:start position:0% +systems you've had lots of courses in +systems every Physics course you've ever + + align:start position:0% +systems every Physics course you've ever + + + align:start position:0% +systems every Physics course you've ever +taken is about + + align:start position:0% + + + + align:start position:0% + +systems what's different about this + + align:start position:0% +systems what's different about this + + + align:start position:0% +systems what's different about this +course is the way we think about systems + + align:start position:0% +course is the way we think about systems + + + align:start position:0% +course is the way we think about systems +we think about systems in a particular + + align:start position:0% +we think about systems in a particular + + + align:start position:0% +we think about systems in a particular +way that turns out to be extraordinarily + + align:start position:0% +way that turns out to be extraordinarily + + + align:start position:0% +way that turns out to be extraordinarily +powerful useful shows up all the time + + align:start position:0% +powerful useful shows up all the time + + + align:start position:0% +powerful useful shows up all the time +and that's what the focus of this course + + align:start position:0% +and that's what the focus of this course + + + align:start position:0% +and that's what the focus of this course +is the the abstraction that we're going + + align:start position:0% +is the the abstraction that we're going + + + align:start position:0% +is the the abstraction that we're going +to use is we think about a system as a + + align:start position:0% +to use is we think about a system as a + + + align:start position:0% +to use is we think about a system as a +thing that has an input and an + + align:start position:0% +thing that has an input and an + + + align:start position:0% +thing that has an input and an +output given the input and the system + + align:start position:0% +output given the input and the system + + + align:start position:0% +output given the input and the system +you can compute the + + align:start position:0% +you can compute the + + + align:start position:0% +you can compute the +output systems have one input and one + + align:start position:0% +output systems have one input and one + + + align:start position:0% +output systems have one input and one +output it's a very special + + align:start position:0% +output it's a very special + + + align:start position:0% +output it's a very special +way of thinking about a + + align:start position:0% +way of thinking about a + + + align:start position:0% +way of thinking about a +system that turns out to be surprisingly + + align:start position:0% +system that turns out to be surprisingly + + + align:start position:0% +system that turns out to be surprisingly +powerful it's so powerful that that's + + align:start position:0% +powerful it's so powerful that that's + + + align:start position:0% +powerful it's so powerful that that's +really the thing that we will focus on + + align:start position:0% +really the thing that we will focus on + + + align:start position:0% +really the thing that we will focus on +in this class so it's the thing that I + + align:start position:0% +in this class so it's the thing that I + + + align:start position:0% +in this class so it's the thing that I +will call + + align:start position:0% +will call + + + align:start position:0% +will call +the + + align:start position:0% +the + + + align:start position:0% +the + + align:start position:0% + + + + align:start position:0% + +abstraction that's going to be the theme + + align:start position:0% +abstraction that's going to be the theme + + + align:start position:0% +abstraction that's going to be the theme +in everything we do that represents + + align:start position:0% +in everything we do that represents + + + align:start position:0% +in everything we do that represents +entation and the best way to get across + + align:start position:0% +entation and the best way to get across + + + align:start position:0% +entation and the best way to get across +I think how that's different from other + + align:start position:0% +I think how that's different from other + + + align:start position:0% +I think how that's different from other +representations that you're already + + align:start position:0% +representations that you're already + + + align:start position:0% +representations that you're already +quite familiar with is to just look at + + align:start position:0% +quite familiar with is to just look at + + + align:start position:0% +quite familiar with is to just look at +an example so here's a system that I'm + + align:start position:0% +an example so here's a system that I'm + + + align:start position:0% +an example so here's a system that I'm +sure you all know all about right this + + align:start position:0% +sure you all know all about right this + + + align:start position:0% +sure you all know all about right this +is not the first time you've seen this + + align:start position:0% +is not the first time you've seen this + + + align:start position:0% +is not the first time you've seen this +kind of a + + align:start position:0% +kind of a + + + align:start position:0% +kind of a +system so you all know how to do this + + align:start position:0% +system so you all know how to do this + + + align:start position:0% +system so you all know how to do this +free body diagrams f equals ma there's + + align:start position:0% +free body diagrams f equals ma there's + + + align:start position:0% +free body diagrams f equals ma there's +an enormous number of ways that you can + + align:start position:0% +an enormous number of ways that you can + + + align:start position:0% +an enormous number of ways that you can +analyze such a system we're going to + + align:start position:0% +analyze such a system we're going to + + + align:start position:0% +analyze such a system we're going to +take a very special approach where we + + align:start position:0% +take a very special approach where we + + + align:start position:0% +take a very special approach where we +think about the + + align:start position:0% +think about the + + + align:start position:0% +think about the +system as having an input and an + + align:start position:0% + + + + align:start position:0% + +output okay that's a little bit + + align:start position:0% +output okay that's a little bit + + + align:start position:0% +output okay that's a little bit +arbitrary we'll say a little more in a + + align:start position:0% +arbitrary we'll say a little more in a + + + align:start position:0% +arbitrary we'll say a little more in a +minute about how arbitrary it is but the + + align:start position:0% +minute about how arbitrary it is but the + + + align:start position:0% +minute about how arbitrary it is but the +idea is going to be that this system the + + align:start position:0% +idea is going to be that this system the + + + align:start position:0% +idea is going to be that this system the +mass spring system the Anvil with a + + align:start position:0% +mass spring system the Anvil with a + + + align:start position:0% +mass spring system the Anvil with a +spring there's an + + align:start position:0% +spring there's an + + + align:start position:0% +spring there's an +input and there's an output so for + + align:start position:0% +input and there's an output so for + + + align:start position:0% +input and there's an output so for +example for some particular purpose I + + align:start position:0% +example for some particular purpose I + + + align:start position:0% +example for some particular purpose I +might want to think that the + + align:start position:0% +might want to think that the + + + align:start position:0% +might want to think that the +input is the position of my + + align:start position:0% +input is the position of my + + + align:start position:0% +input is the position of my +hand one reason I might want to think + + align:start position:0% +hand one reason I might want to think + + + align:start position:0% +hand one reason I might want to think +about that is it is under my control so + + align:start position:0% +about that is it is under my control so + + + align:start position:0% +about that is it is under my control so +it might be reasonable to think about my + + align:start position:0% +it might be reasonable to think about my + + + align:start position:0% +it might be reasonable to think about my +hand being the input so for example my + + align:start position:0% +hand being the input so for example my + + + align:start position:0% +hand being the input so for example my +hand can do + + align:start position:0% +hand can do + + + align:start position:0% +hand can do +this right so I might think about the + + align:start position:0% +this right so I might think about the + + + align:start position:0% +this right so I might think about the +position of my hand being the + + align:start position:0% +position of my hand being the + + + align:start position:0% +position of my hand being the +input so if I did that then what I could + + align:start position:0% +input so if I did that then what I could + + + align:start position:0% +input so if I did that then what I could +do is characterize the input by some + + align:start position:0% +do is characterize the input by some + + + align:start position:0% +do is characterize the input by some +waveform a + + align:start position:0% + + + + align:start position:0% + +signal in order to use the abstraction I + + align:start position:0% +signal in order to use the abstraction I + + + align:start position:0% +signal in order to use the abstraction I +also have to say what the output is I + + align:start position:0% +also have to say what the output is I + + + align:start position:0% +also have to say what the output is I +might be interested for example in + + align:start position:0% +might be interested for example in + + + align:start position:0% +might be interested for example in +knowing the position of the + + align:start position:0% +knowing the position of the + + + align:start position:0% +knowing the position of the +mass then the output would be the + + align:start position:0% +mass then the output would be the + + + align:start position:0% +mass then the output would be the +displacement of the + + align:start position:0% +displacement of the + + + align:start position:0% +displacement of the +mass that assignment of input and output + + align:start position:0% +mass that assignment of input and output + + + align:start position:0% +mass that assignment of input and output +is somewhat + + align:start position:0% + + + + align:start position:0% + +arbitrary I get to choose that to make + + align:start position:0% +arbitrary I get to choose that to make + + + align:start position:0% +arbitrary I get to choose that to make +the problem that I'm interested it in as + + align:start position:0% +the problem that I'm interested it in as + + + align:start position:0% +the problem that I'm interested it in as +easy as + + align:start position:0% +easy as + + + align:start position:0% +easy as +possible so for example if I'm thinking + + align:start position:0% +possible so for example if I'm thinking + + + align:start position:0% +possible so for example if I'm thinking +about this uh mass and spring system + + align:start position:0% +about this uh mass and spring system + + + align:start position:0% +about this uh mass and spring system +here at using my hand as the input that + + align:start position:0% +here at using my hand as the input that + + + align:start position:0% +here at using my hand as the input that +seems kind of natural because that's the + + align:start position:0% +seems kind of natural because that's the + + + align:start position:0% +seems kind of natural because that's the +thing I control thinking about the + + align:start position:0% +thing I control thinking about the + + + align:start position:0% +thing I control thinking about the +position of the mass as the output that + + align:start position:0% +position of the mass as the output that + + + align:start position:0% +position of the mass as the output that +seems reasonable because that's the PCT + + align:start position:0% +seems reasonable because that's the PCT + + + align:start position:0% +seems reasonable because that's the PCT +that's the thing you could take a + + align:start position:0% +that's the thing you could take a + + + align:start position:0% +that's the thing you could take a +picture of it's the thing you can + + align:start position:0% +picture of it's the thing you can + + + align:start position:0% +picture of it's the thing you can +observe from where you are now but it's + + align:start position:0% +observe from where you are now but it's + + + align:start position:0% +observe from where you are now but it's +not unique I might have wanted to think + + align:start position:0% +not unique I might have wanted to think + + + align:start position:0% +not unique I might have wanted to think +about the force that I'm putting into it + + align:start position:0% +about the force that I'm putting into it + + + align:start position:0% +about the force that I'm putting into it +as the + + align:start position:0% +as the + + + align:start position:0% +as the +input I might have wanted to think about + + align:start position:0% +input I might have wanted to think about + + + align:start position:0% +input I might have wanted to think about +the output being the acceleration of the + + align:start position:0% +the output being the acceleration of the + + + align:start position:0% +the output being the acceleration of the +mass maybe maybe there's some limit to + + align:start position:0% +mass maybe maybe there's some limit to + + + align:start position:0% +mass maybe maybe there's some limit to +how much acceleration some Mass can can + + align:start position:0% +how much acceleration some Mass can can + + + align:start position:0% +how much acceleration some Mass can can +take so you get to choose the input and + + align:start position:0% +take so you get to choose the input and + + + align:start position:0% +take so you get to choose the input and +the + + align:start position:0% +the + + + align:start position:0% +the +output but you have to choose an input + + align:start position:0% +output but you have to choose an input + + + align:start position:0% +output but you have to choose an input +and an output that's part of the + + align:start position:0% +and an output that's part of the + + + align:start position:0% +and an output that's part of the +abstraction and that's part of the power + + align:start position:0% +abstraction and that's part of the power + + + align:start position:0% +abstraction and that's part of the power +we'll see later that part of the power + + align:start position:0% +we'll see later that part of the power + + + align:start position:0% +we'll see later that part of the power +of doing it this way is that you draw + + align:start position:0% +of doing it this way is that you draw + + + align:start position:0% +of doing it this way is that you draw +attention to the things things of + + align:start position:0% +attention to the things things of + + + align:start position:0% +attention to the things things of +interest and push into the background + + align:start position:0% +interest and push into the background + + + align:start position:0% +interest and push into the background +the parts that are not of interest at + + align:start position:0% +the parts that are not of interest at + + + align:start position:0% +the parts that are not of interest at +least not + + align:start position:0% + + + + align:start position:0% + +now this kind of an abstraction is + + align:start position:0% +now this kind of an abstraction is + + + align:start position:0% +now this kind of an abstraction is +extremely + + align:start position:0% +extremely + + + align:start position:0% +extremely +versatile here's a completely different + + align:start position:0% +versatile here's a completely different + + + align:start position:0% +versatile here's a completely different +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +problem imagine water flowing into a + + align:start position:0% +problem imagine water flowing into a + + + align:start position:0% +problem imagine water flowing into a +tank the Tank's leaky so it flows + + align:start position:0% +tank the Tank's leaky so it flows + + + align:start position:0% +tank the Tank's leaky so it flows +out there's a second tank okay what on + + align:start position:0% +out there's a second tank okay what on + + + align:start position:0% +out there's a second tank okay what on +Earth could this be this could be maybe + + align:start position:0% +Earth could this be this could be maybe + + + align:start position:0% +Earth could this be this could be maybe +this is the it's appropriate to today + + align:start position:0% +this is the it's appropriate to today + + + align:start position:0% +this is the it's appropriate to today +right it's raining or it was raining uh + + align:start position:0% +right it's raining or it was raining uh + + + align:start position:0% +right it's raining or it was raining uh +so it was pouring when I came in it was + + align:start position:0% +so it was pouring when I came in it was + + + align:start position:0% +so it was pouring when I came in it was +pouring uh maybe this + + align:start position:0% +pouring uh maybe this + + + align:start position:0% +pouring uh maybe this +is nature delivering + + align:start position:0% +is nature delivering + + + align:start position:0% +is nature delivering +rain this is the wuber + + align:start position:0% +rain this is the wuber + + + align:start position:0% +rain this is the wuber +reservoir from which we get water in + + align:start position:0% +reservoir from which we get water in + + + align:start position:0% +reservoir from which we get water in +Boston maybe this is the Fresh Pond + + align:start position:0% +Boston maybe this is the Fresh Pond + + + align:start position:0% +Boston maybe this is the Fresh Pond +Reservoir from which we get water in + + align:start position:0% +Reservoir from which we get water in + + + align:start position:0% +Reservoir from which we get water in +Cambridge maybe this is is the rate at + + align:start position:0% +Cambridge maybe this is is the rate at + + + align:start position:0% +Cambridge maybe this is is the rate at +which water goes from wubber + + align:start position:0% +which water goes from wubber + + + align:start position:0% +which water goes from wubber +to Fresh + + align:start position:0% +to Fresh + + + align:start position:0% +to Fresh +Pond maybe this is the rate at which + + align:start position:0% +Pond maybe this is the rate at which + + + align:start position:0% +Pond maybe this is the rate at which +water leaves Fresh Pond and goes into + + align:start position:0% +water leaves Fresh Pond and goes into + + + align:start position:0% +water leaves Fresh Pond and goes into +consumers + + align:start position:0% +consumers + + + align:start position:0% +consumers +houses the point is that there's some + + align:start position:0% +houses the point is that there's some + + + align:start position:0% +houses the point is that there's some +abstraction there's there's some + + align:start position:0% +abstraction there's there's some + + + align:start position:0% +abstraction there's there's some +physical I didn't say that right there's + + align:start position:0% +physical I didn't say that right there's + + + align:start position:0% +physical I didn't say that right there's +a physical + + align:start position:0% +a physical + + + align:start position:0% +a physical +thing rain wuber Wu Reservoir um Fresh + + align:start position:0% +thing rain wuber Wu Reservoir um Fresh + + + align:start position:0% +thing rain wuber Wu Reservoir um Fresh +Pond Reservoir consumer houses there + + align:start position:0% +Pond Reservoir consumer houses there + + + align:start position:0% +Pond Reservoir consumer houses there +some physical thing there's some laws of + + align:start position:0% +some physical thing there's some laws of + + + align:start position:0% +some physical thing there's some laws of +physics that dictate things but we + + align:start position:0% +physics that dictate things but we + + + align:start position:0% +physics that dictate things but we +ignore or ignore is not quite the right + + align:start position:0% +ignore or ignore is not quite the right + + + align:start position:0% +ignore or ignore is not quite the right +way to think about it we think about + + align:start position:0% +way to think about it we think about + + + align:start position:0% +way to think about it we think about +those rules of physics as rules that + + align:start position:0% +those rules of physics as rules that + + + align:start position:0% +those rules of physics as rules that +govern the input output relationship so + + align:start position:0% +govern the input output relationship so + + + align:start position:0% +govern the input output relationship so +we think about then the entire system + + align:start position:0% +we think about then the entire system + + + align:start position:0% +we think about then the entire system +rather than thinking about it as + + align:start position:0% +rather than thinking about it as + + + align:start position:0% +rather than thinking about it as +reservoirs and rain and water and flow + + align:start position:0% +reservoirs and rain and water and flow + + + align:start position:0% +reservoirs and rain and water and flow +and all that sort of thing we think + + align:start position:0% +and all that sort of thing we think + + + align:start position:0% +and all that sort of thing we think +about it as there's a signal + + align:start position:0% +about it as there's a signal + + + align:start position:0% +about it as there's a signal +in rain + + align:start position:0% +in rain + + + align:start position:0% +in rain +and there's a signal out water + + align:start position:0% +and there's a signal out water + + + align:start position:0% +and there's a signal out water +usage and we take all the details of the + + align:start position:0% +usage and we take all the details of the + + + align:start position:0% +usage and we take all the details of the +system and bury it in this box it's an + + align:start position:0% +system and bury it in this box it's an + + + align:start position:0% +system and bury it in this box it's an +abstraction it's a way to suppress some + + align:start position:0% +abstraction it's a way to suppress some + + + align:start position:0% +abstraction it's a way to suppress some +details to highlight + + align:start position:0% + + + + align:start position:0% + +others okay it's and we use this in huge + + align:start position:0% +others okay it's and we use this in huge + + + align:start position:0% +others okay it's and we use this in huge +variety of situations we can think about + + align:start position:0% +variety of situations we can think about + + + align:start position:0% +variety of situations we can think about +a third example here a cell phone cell + + align:start position:0% +a third example here a cell phone cell + + + align:start position:0% +a third example here a cell phone cell +phone is enormously complicated system + + align:start position:0% +phone is enormously complicated system + + + align:start position:0% +phone is enormously complicated system +but for the purpose of understanding the + + align:start position:0% +but for the purpose of understanding the + + + align:start position:0% +but for the purpose of understanding the +input output + + align:start position:0% +input output + + + align:start position:0% +input output +characteristics if what I really want to + + align:start position:0% +characteristics if what I really want to + + + align:start position:0% +characteristics if what I really want to +know is how good is the quality of the + + align:start position:0% +know is how good is the quality of the + + + align:start position:0% +know is how good is the quality of the +audio not that that's even a little bit + + align:start position:0% +audio not that that's even a little bit + + + align:start position:0% +audio not that that's even a little bit +important for cell phones right cell + + align:start position:0% +important for cell phones right cell + + + align:start position:0% +important for cell phones right cell +phones are important for texting and + + align:start position:0% +phones are important for texting and + + + align:start position:0% +phones are important for texting and +taking pictures and have nothing to do + + align:start position:0% +taking pictures and have nothing to do + + + align:start position:0% +taking pictures and have nothing to do +with voice but in the old days cell + + align:start position:0% +with voice but in the old days cell + + + align:start position:0% +with voice but in the old days cell +phones had to do with voice and I made + + align:start position:0% +phones had to do with voice and I made + + + align:start position:0% +phones had to do with voice and I made +this slide back when that was still true + + align:start position:0% +this slide back when that was still true + + + align:start position:0% +this slide back when that was still true +so I apologize it's out of date um so + + align:start position:0% +so I apologize it's out of date um so + + + align:start position:0% +so I apologize it's out of date um so +here the important thing of the cell + + align:start position:0% +here the important thing of the cell + + + align:start position:0% +here the important thing of the cell +phone system was the sound in and the + + align:start position:0% +phone system was the sound in and the + + + align:start position:0% +phone system was the sound in and the +sound out + + align:start position:0% +sound out + + + align:start position:0% +sound out +and the idea was to represent the cell + + align:start position:0% +and the idea was to represent the cell + + + align:start position:0% +and the idea was to represent the cell +phone system by the + + align:start position:0% +phone system by the + + + align:start position:0% +phone system by the +transformation between how the sound + + align:start position:0% +transformation between how the sound + + + align:start position:0% +transformation between how the sound +comes in and how the sound comes + + align:start position:0% +comes in and how the sound comes + + + align:start position:0% +comes in and how the sound comes +out okay so we do this for an enormous + + align:start position:0% +out okay so we do this for an enormous + + + align:start position:0% +out okay so we do this for an enormous +number of reasons one is that it's + + align:start position:0% +number of reasons one is that it's + + + align:start position:0% +number of reasons one is that it's +widely applicable you can do this kind + + align:start position:0% +widely applicable you can do this kind + + + align:start position:0% +widely applicable you can do this kind +of a characterization for systems from + + align:start position:0% +of a characterization for systems from + + + align:start position:0% +of a characterization for systems from +uh electrical systems mechanical systems + + align:start position:0% +uh electrical systems mechanical systems + + + align:start position:0% +uh electrical systems mechanical systems +Optical systems acoustic systems + + align:start position:0% +Optical systems acoustic systems + + + align:start position:0% +Optical systems acoustic systems +biological systems Financial systems all + + align:start position:0% +biological systems Financial systems all + + + align:start position:0% +biological systems Financial systems all +over the + + align:start position:0% +over the + + + align:start position:0% +over the +place + + align:start position:0% +place + + + align:start position:0% +place +that means that this kind of an approach + + align:start position:0% +that means that this kind of an approach + + + align:start position:0% +that means that this kind of an approach +is very powerful because it's so widely + + align:start position:0% +is very powerful because it's so widely + + + align:start position:0% +is very powerful because it's so widely +applicable it also means that for + + align:start position:0% +applicable it also means that for + + + align:start position:0% +applicable it also means that for +example every engineering discipline + + align:start position:0% +example every engineering discipline + + + align:start position:0% +example every engineering discipline +everywhere has some course like this + + align:start position:0% +everywhere has some course like this + + + align:start position:0% +everywhere has some course like this +it's just too powerful not to do + + align:start position:0% +it's just too powerful not to do + + + align:start position:0% +it's just too powerful not to do +it so what regardless of what department + + align:start position:0% +it so what regardless of what department + + + align:start position:0% +it so what regardless of what department +you were in in the School of Engineering + + align:start position:0% +you were in in the School of Engineering + + + align:start position:0% +you were in in the School of Engineering +for example there is something like + + align:start position:0% + + + + align:start position:0% + +this another reason this is interesting + + align:start position:0% +this another reason this is interesting + + + align:start position:0% +this another reason this is interesting +is that it provides a layer of + + align:start position:0% +is that it provides a layer of + + + align:start position:0% +is that it provides a layer of +abstraction that lets you focus on + + align:start position:0% +abstraction that lets you focus on + + + align:start position:0% +abstraction that lets you focus on +certain things so for example let's + + align:start position:0% +certain things so for example let's + + + align:start position:0% +certain things so for example let's +expand on the cell phone network imagine + + align:start position:0% +expand on the cell phone network imagine + + + align:start position:0% +expand on the cell phone network imagine +that sound comes into a cell phone well + + align:start position:0% +that sound comes into a cell phone well + + + align:start position:0% +that sound comes into a cell phone well +the job of the phone is to communicate + + align:start position:0% +the job of the phone is to communicate + + + align:start position:0% +the job of the phone is to communicate +to a + + align:start position:0% +to a + + + align:start position:0% +to a +tower and that communication is via some + + align:start position:0% +tower and that communication is via some + + + align:start position:0% +tower and that communication is via some +electromag magnetic + + align:start position:0% +electromag magnetic + + + align:start position:0% +electromag magnetic +signal then the job of the tower is to + + align:start position:0% +signal then the job of the tower is to + + + align:start position:0% +signal then the job of the tower is to +communicate with another + + align:start position:0% +communicate with another + + + align:start position:0% +communicate with another +tower that happens in all kinds of ways + + align:start position:0% +tower that happens in all kinds of ways + + + align:start position:0% +tower that happens in all kinds of ways +it could be if optic link it could be a + + align:start position:0% +it could be if optic link it could be a + + + align:start position:0% +it could be if optic link it could be a +satellite link it could be + + align:start position:0% +satellite link it could be + + + align:start position:0% +satellite link it could be +electromagnetism it could be lots of + + align:start position:0% +electromagnetism it could be lots of + + + align:start position:0% +electromagnetism it could be lots of +different things there's a lot of + + align:start position:0% +different things there's a lot of + + + align:start position:0% +different things there's a lot of +different Technologies for getting + + align:start position:0% +different Technologies for getting + + + align:start position:0% +different Technologies for getting +Towers to talk to Towers then Towers + + align:start position:0% +Towers to talk to Towers then Towers + + + align:start position:0% +Towers to talk to Towers then Towers +talk back to cell phones via + + align:start position:0% +talk back to cell phones via + + + align:start position:0% +talk back to cell phones via +electromagnetic signals just like these + + align:start position:0% +electromagnetic signals just like these + + + align:start position:0% +electromagnetic signals just like these +and gener and the cell phone eventually + + align:start position:0% +and gener and the cell phone eventually + + + align:start position:0% +and gener and the cell phone eventually +generates an acoustical + + align:start position:0% +generates an acoustical + + + align:start position:0% +generates an acoustical +output the idea is that by thinking + + align:start position:0% +output the idea is that by thinking + + + align:start position:0% +output the idea is that by thinking +about the signals and systems approach + + align:start position:0% +about the signals and systems approach + + + align:start position:0% +about the signals and systems approach +we have um abstracted away everything + + align:start position:0% +we have um abstracted away everything + + + align:start position:0% +we have um abstracted away everything +other than the flow of information + + align:start position:0% +other than the flow of information + + + align:start position:0% +other than the flow of information +it makes it easy to + + align:start position:0% +it makes it easy to + + + align:start position:0% +it makes it easy to +concentrate to follow the flow of + + align:start position:0% +concentrate to follow the flow of + + + align:start position:0% +concentrate to follow the flow of +information through a complex + + align:start position:0% +information through a complex + + + align:start position:0% +information through a complex +system because we have pushed every + + align:start position:0% +system because we have pushed every + + + align:start position:0% +system because we have pushed every +element into the same framework every + + align:start position:0% +element into the same framework every + + + align:start position:0% +element into the same framework every +element has an input and + + align:start position:0% +element has an input and + + + align:start position:0% +element has an input and +output regardless of the underlying + + align:start position:0% +output regardless of the underlying + + + align:start position:0% +output regardless of the underlying +substrate the analysis is + + align:start position:0% +substrate the analysis is + + + align:start position:0% +substrate the analysis is +similar that means that components who + + align:start position:0% +similar that means that components who + + + align:start position:0% +similar that means that components who +that are characterized using the + + align:start position:0% +that are characterized using the + + + align:start position:0% +that are characterized using the +substraction are easily + + align:start position:0% +substraction are easily + + + align:start position:0% +substraction are easily +combined so we refer to this as we say + + align:start position:0% +combined so we refer to this as we say + + + align:start position:0% +combined so we refer to this as we say +that these systems are + + align:start position:0% +that these systems are + + + align:start position:0% +that these systems are +combinational they're combinational in + + align:start position:0% +combinational they're combinational in + + + align:start position:0% +combinational they're combinational in +the same sense that python was + + align:start position:0% +the same sense that python was + + + align:start position:0% +the same sense that python was +combinational in + + align:start position:0% +combinational in + + + align:start position:0% +combinational in +601 if you represent things by python + + align:start position:0% +601 if you represent things by python + + + align:start position:0% +601 if you represent things by python +functions it's very easy to combine the + + align:start position:0% +functions it's very easy to combine the + + + align:start position:0% +functions it's very easy to combine the +functions to have a bigger + + align:start position:0% +functions to have a bigger + + + align:start position:0% +functions to have a bigger +function whose purpose and details can + + align:start position:0% +function whose purpose and details can + + + align:start position:0% +function whose purpose and details can +be understood without knowing what was + + align:start position:0% +be understood without knowing what was + + + align:start position:0% +be understood without knowing what was +was inside every individual + + align:start position:0% +was inside every individual + + + align:start position:0% +was inside every individual +function similarly here by knowing the + + align:start position:0% +function similarly here by knowing the + + + align:start position:0% +function similarly here by knowing the +input Behavior the input output behavior + + align:start position:0% +input Behavior the input output behavior + + + align:start position:0% +input Behavior the input output behavior +of the cell phone the input output + + align:start position:0% +of the cell phone the input output + + + align:start position:0% +of the cell phone the input output +behavior of the tower the input output + + align:start position:0% +behavior of the tower the input output + + + align:start position:0% +behavior of the tower the input output +behavior of this Tower is easy to + + align:start position:0% +behavior of this Tower is easy to + + + align:start position:0% +behavior of this Tower is easy to +compose them and in fact we will spend a + + align:start position:0% +compose them and in fact we will spend a + + + align:start position:0% +compose them and in fact we will spend a +fair amount of time thinking through the + + align:start position:0% +fair amount of time thinking through the + + + align:start position:0% +fair amount of time thinking through the +rules of + + align:start position:0% + + + + align:start position:0% + +combination um so that's kind of an + + align:start position:0% +combination um so that's kind of an + + + align:start position:0% +combination um so that's kind of an +overview of the most important thing + + align:start position:0% +overview of the most important thing + + + align:start position:0% +overview of the most important thing +we're going to talk about in this class + + align:start position:0% +we're going to talk about in this class + + + align:start position:0% +we're going to talk about in this class +which is the 63 abstraction the idea of + + align:start position:0% +which is the 63 abstraction the idea of + + + align:start position:0% +which is the 63 abstraction the idea of +representing a + + align:start position:0% +representing a + + + align:start position:0% +representing a +system by the way it transforms an input + + align:start position:0% +system by the way it transforms an input + + + align:start position:0% +system by the way it transforms an input +into an + + align:start position:0% +into an + + + align:start position:0% +into an +output so with that kind of overview + + align:start position:0% +output so with that kind of overview + + + align:start position:0% +output so with that kind of overview +what I want to do next is say a little + + align:start position:0% +what I want to do next is say a little + + + align:start position:0% +what I want to do next is say a little +more about what are signals and what are + + align:start position:0% +more about what are signals and what are + + + align:start position:0% +more about what are signals and what are +systems it's the signals and systems + + align:start position:0% +systems it's the signals and systems + + + align:start position:0% +systems it's the signals and systems +abstraction we're going to need to know + + align:start position:0% +abstraction we're going to need to know + + + align:start position:0% +abstraction we're going to need to know +some more details about what is a + + align:start position:0% +some more details about what is a + + + align:start position:0% +some more details about what is a +signal and what is a + + align:start position:0% +signal and what is a + + + align:start position:0% +signal and what is a +system so basically a signal is just a + + align:start position:0% +system so basically a signal is just a + + + align:start position:0% +system so basically a signal is just a +mathematical function in all the + + align:start position:0% +mathematical function in all the + + + align:start position:0% +mathematical function in all the +examples I talked about so + + align:start position:0% +examples I talked about so + + + align:start position:0% +examples I talked about so +far and in many of the examples that + + align:start position:0% +far and in many of the examples that + + + align:start position:0% +far and in many of the examples that +we'll talk about throughout the + + align:start position:0% +we'll talk about throughout the + + + align:start position:0% +we'll talk about throughout the +term the function is a function of + + align:start position:0% +term the function is a function of + + + align:start position:0% +term the function is a function of +time and the signal can have many + + align:start position:0% +time and the signal can have many + + + align:start position:0% +time and the signal can have many +different dimensions so for example the + + align:start position:0% +different dimensions so for example the + + + align:start position:0% +different dimensions so for example the +mass spring system uh evolved as a + + align:start position:0% +mass spring system uh evolved as a + + + align:start position:0% +mass spring system uh evolved as a +function of time the tank system The + + align:start position:0% +function of time the tank system The + + + align:start position:0% +function of time the tank system The +Leaky tank system evolved as a function + + align:start position:0% +Leaky tank system evolved as a function + + + align:start position:0% +Leaky tank system evolved as a function +of time the cell phone system had + + align:start position:0% +of time the cell phone system had + + + align:start position:0% +of time the cell phone system had +acoustic signals that were functions of + + align:start position:0% +acoustic signals that were functions of + + + align:start position:0% +acoustic signals that were functions of +time time was the same in each case but + + align:start position:0% +time time was the same in each case but + + + align:start position:0% +time time was the same in each case but +the dependent variable can be a a + + align:start position:0% +the dependent variable can be a a + + + align:start position:0% +the dependent variable can be a a +variety of things here it was + + align:start position:0% +variety of things here it was + + + align:start position:0% +variety of things here it was +position so here it was flow rates meter + + align:start position:0% +position so here it was flow rates meter + + + align:start position:0% +position so here it was flow rates meter +cubed per second of + + align:start position:0% +cubed per second of + + + align:start position:0% +cubed per second of +water uh here it was uh perhaps Pascal's + + align:start position:0% +water uh here it was uh perhaps Pascal's + + + align:start position:0% +water uh here it was uh perhaps Pascal's +some unit of pressure to characterize + + align:start position:0% +some unit of pressure to characterize + + + align:start position:0% +some unit of pressure to characterize +the acoustic waveform + + align:start position:0% +the acoustic waveform + + + align:start position:0% +the acoustic waveform +so the point is that signals are + + align:start position:0% +so the point is that signals are + + + align:start position:0% +so the point is that signals are +generally + + align:start position:0% +generally + + + align:start position:0% +generally +functions we'll see that just like + + align:start position:0% +functions we'll see that just like + + + align:start position:0% +functions we'll see that just like +functions in + + align:start position:0% +functions in + + + align:start position:0% +functions in +mathematics there's a lot more to + + align:start position:0% +mathematics there's a lot more to + + + align:start position:0% +mathematics there's a lot more to +functions than dependent variables and + + align:start position:0% +functions than dependent variables and + + + align:start position:0% +functions than dependent variables and +independent variables and in fact that's + + align:start position:0% +independent variables and in fact that's + + + align:start position:0% +independent variables and in fact that's +going to be a key feature of our + + align:start position:0% +going to be a key feature of our + + + align:start position:0% +going to be a key feature of our +analysis of signals but that's to come + + align:start position:0% +analysis of signals but that's to come + + + align:start position:0% +analysis of signals but that's to come +so for the time being the simplest and + + align:start position:0% +so for the time being the simplest and + + + align:start position:0% +so for the time being the simplest and +complete model for what a signal is is + + align:start position:0% +complete model for what a signal is is + + + align:start position:0% +complete model for what a signal is is +it's just a function the function + + align:start position:0% +it's just a function the function + + + align:start position:0% +it's just a function the function +doesn't have to be a onedimensional + + align:start position:0% +doesn't have to be a onedimensional + + + align:start position:0% +doesn't have to be a onedimensional +function in fact a lot of the + + align:start position:0% +function in fact a lot of the + + + align:start position:0% +function in fact a lot of the +interesting um applications of signals + + align:start position:0% +interesting um applications of signals + + + align:start position:0% +interesting um applications of signals +and systems is to look at + + align:start position:0% +and systems is to look at + + + align:start position:0% +and systems is to look at +multi-dimensional functions so for + + align:start position:0% +multi-dimensional functions so for + + + align:start position:0% +multi-dimensional functions so for +example my research is in + + align:start position:0% +example my research is in + + + align:start position:0% +example my research is in +hearing I'm interested to + + align:start position:0% +hearing I'm interested to + + + align:start position:0% +hearing I'm interested to +study how do the cells respond to sound + + align:start position:0% +study how do the cells respond to sound + + + align:start position:0% +study how do the cells respond to sound +so that we can understand how broken + + align:start position:0% +so that we can understand how broken + + + align:start position:0% +so that we can understand how broken +ears work + + align:start position:0% +ears work + + + align:start position:0% +ears work +differently when you have a when you + + align:start position:0% +differently when you have a when you + + + align:start position:0% +differently when you have a when you +have a hearing deficit like I do when + + align:start position:0% +have a hearing deficit like I do when + + + align:start position:0% +have a hearing deficit like I do when +you have a hearing deficit how it what + + align:start position:0% +you have a hearing deficit how it what + + + align:start position:0% +you have a hearing deficit how it what +is the manifestation of that at a signal + + align:start position:0% +is the manifestation of that at a signal + + + align:start position:0% +is the manifestation of that at a signal +processing level how do the cells + + align:start position:0% +processing level how do the cells + + + align:start position:0% +processing level how do the cells +respond differently to people who have + + align:start position:0% +respond differently to people who have + + + align:start position:0% +respond differently to people who have +impaired hearing from people who have + + align:start position:0% +impaired hearing from people who have + + + align:start position:0% +impaired hearing from people who have +normal + + align:start position:0% +normal + + + align:start position:0% +normal +hearing uh in order to study that + + align:start position:0% +hearing uh in order to study that + + + align:start position:0% +hearing uh in order to study that +problem we take video + + align:start position:0% +problem we take video + + + align:start position:0% +problem we take video +pictures of the cells at large + + align:start position:0% +pictures of the cells at large + + + align:start position:0% +pictures of the cells at large +magnifications and watch them wiggle + + align:start position:0% +magnifications and watch them wiggle + + + align:start position:0% +magnifications and watch them wiggle +when sounds hit + + align:start position:0% +when sounds hit + + + align:start position:0% +when sounds hit +them so that's a picture processing + + align:start position:0% +them so that's a picture processing + + + align:start position:0% +them so that's a picture processing +example so the signals are not the + + align:start position:0% +example so the signals are not the + + + align:start position:0% +example so the signals are not the +independent variable is not just time + + align:start position:0% +independent variable is not just time + + + align:start position:0% +independent variable is not just time +it's a picture so it might have X and + + align:start position:0% +it's a picture so it might have X and + + + align:start position:0% +it's a picture so it might have X and +Y in fact the pictures we take are three + + align:start position:0% +Y in fact the pictures we take are three + + + align:start position:0% +Y in fact the pictures we take are three +dimensional so it has X Y and Z and in + + align:start position:0% +dimensional so it has X Y and Z and in + + + align:start position:0% +dimensional so it has X Y and Z and in +fact they're four dimensional because + + align:start position:0% +fact they're four dimensional because + + + align:start position:0% +fact they're four dimensional because +they change with + + align:start position:0% +they change with + + + align:start position:0% +they change with +time so we do we apply this kind of a + + align:start position:0% +time so we do we apply this kind of a + + + align:start position:0% +time so we do we apply this kind of a +technique on 4D signals X YZ time but + + align:start position:0% +technique on 4D signals X YZ time but + + + align:start position:0% +technique on 4D signals X YZ time but +it's still the the property it still has + + align:start position:0% +it's still the the property it still has + + + align:start position:0% +it's still the the property it still has +a property that the signals of Interest + + align:start position:0% +a property that the signals of Interest + + + align:start position:0% +a property that the signals of Interest +are + + align:start position:0% +are + + + align:start position:0% +are +functions + + align:start position:0% +functions + + + align:start position:0% +functions +we will have an we will be especially + + align:start position:0% +we will have an we will be especially + + + align:start position:0% +we will have an we will be especially +interested in this + + align:start position:0% +interested in this + + + align:start position:0% +interested in this +class in two distinct representations of + + align:start position:0% +class in two distinct representations of + + + align:start position:0% +class in two distinct representations of +signals we will call them CT signals and + + align:start position:0% +signals we will call them CT signals and + + + align:start position:0% +signals we will call them CT signals and +DT signals CT is continuous time DT is + + align:start position:0% +DT signals CT is continuous time DT is + + + align:start position:0% +DT signals CT is continuous time DT is +discreet time we're very interested in + + align:start position:0% +discreet time we're very interested in + + + align:start position:0% +discreet time we're very interested in +that because we're + + align:start position:0% + + + + align:start position:0% + +Engineers a lot of + + align:start position:0% +Engineers a lot of + + + align:start position:0% +Engineers a lot of +physics lives in continuous + + align:start position:0% +physics lives in continuous + + + align:start position:0% +physics lives in continuous +time okay the m spring dashbot system + + align:start position:0% +time okay the m spring dashbot system + + + align:start position:0% +time okay the m spring dashbot system +the signals were functions of + + align:start position:0% +the signals were functions of + + + align:start position:0% +the signals were functions of +time time was a continuously varying uh + + align:start position:0% +time time was a continuously varying uh + + + align:start position:0% +time time was a continuously varying uh +independent + + align:start position:0% +independent + + + align:start position:0% +independent +variable so uh so the Leaky tank the + + align:start position:0% +variable so uh so the Leaky tank the + + + align:start position:0% +variable so uh so the Leaky tank the +cell phones those were all systems whose + + align:start position:0% +cell phones those were all systems whose + + + align:start position:0% +cell phones those were all systems whose +signals evolve in time uh so they're all + + align:start position:0% +signals evolve in time uh so they're all + + + align:start position:0% +signals evolve in time uh so they're all +continuous you can you can start with a + + align:start position:0% +continuous you can you can start with a + + + align:start position:0% +continuous you can you can start with a +second and break it in half and get a + + align:start position:0% +second and break it in half and get a + + + align:start position:0% +second and break it in half and get a +half a second and a half and a half and + + align:start position:0% +half a second and a half and a half and + + + align:start position:0% +half a second and a half and a half and +a half and there's no limit to how many + + align:start position:0% +a half and there's no limit to how many + + + align:start position:0% +a half and there's no limit to how many +halves you can take + + align:start position:0% +halves you can take + + + align:start position:0% +halves you can take +by contrast a lot of the a lot of the + + align:start position:0% +by contrast a lot of the a lot of the + + + align:start position:0% +by contrast a lot of the a lot of the +systems that we will look at are things + + align:start position:0% +systems that we will look at are things + + + align:start position:0% +systems that we will look at are things +that are um that evolve in discrete time + + align:start position:0% +that are um that evolve in discrete time + + + align:start position:0% +that are um that evolve in discrete time +what's your bank account well it only + + align:start position:0% +what's your bank account well it only + + + align:start position:0% +what's your bank account well it only +gets computed once a + + align:start position:0% +gets computed once a + + + align:start position:0% +gets computed once a +day so it doesn't make sense to talk + + align:start position:0% +day so it doesn't make sense to talk + + + align:start position:0% +day so it doesn't make sense to talk +about your bank account at 9:00 am and + + align:start position:0% +about your bank account at 9:00 am and + + + align:start position:0% +about your bank account at 9:00 am and +and and 2 p.m right the bank account + + align:start position:0% +and and 2 p.m right the bank account + + + align:start position:0% +and and 2 p.m right the bank account +updates your account the the bank + + align:start position:0% +updates your account the the bank + + + align:start position:0% +updates your account the the bank +updates your account once a day so it's + + align:start position:0% +updates your account once a day so it's + + + align:start position:0% +updates your account once a day so it's +something that happens in discret time + + align:start position:0% +something that happens in discret time + + + align:start position:0% +something that happens in discret time +it's something that happens in all + + align:start position:0% +it's something that happens in all + + + align:start position:0% +it's something that happens in all +computational + + align:start position:0% +computational + + + align:start position:0% +computational +systems so computational systems + + align:start position:0% +systems so computational systems + + + align:start position:0% +systems so computational systems +generally operate on signals that uh + + align:start position:0% +generally operate on signals that uh + + + align:start position:0% +generally operate on signals that uh +that are functions of discret + + align:start position:0% +that are functions of discret + + + align:start position:0% +that are functions of discret +time what was the state at Time Zero + + align:start position:0% +time what was the state at Time Zero + + + align:start position:0% +time what was the state at Time Zero +what was the state at time one what was + + align:start position:0% +what was the state at time one what was + + + align:start position:0% +what was the state at time one what was +the state at time + + align:start position:0% +the state at time + + + align:start position:0% +the state at time +two so the system is something that eats + + align:start position:0% +two so the system is something that eats + + + align:start position:0% +two so the system is something that eats +a discrete time signal and generates a + + align:start position:0% +a discrete time signal and generates a + + + align:start position:0% +a discrete time signal and generates a +discrete time + + align:start position:0% +discrete time + + + align:start position:0% +discrete time +output + + align:start position:0% +output + + + align:start position:0% +output +signal and a unique part of this class + + align:start position:0% +signal and a unique part of this class + + + align:start position:0% +signal and a unique part of this class +will be converting between the two + + align:start position:0% +will be converting between the two + + + align:start position:0% +will be converting between the two +representations because as Engineers we + + align:start position:0% +representations because as Engineers we + + + align:start position:0% +representations because as Engineers we +often want to take build something that + + align:start position:0% +often want to take build something that + + + align:start position:0% +often want to take build something that +operates in the physical world masses + + align:start position:0% +operates in the physical world masses + + + align:start position:0% +operates in the physical world masses +and springs and reservoirs and that kind + + align:start position:0% +and springs and reservoirs and that kind + + + align:start position:0% +and springs and reservoirs and that kind +of + + align:start position:0% +of + + + align:start position:0% +of +stuff and do the processing + + align:start position:0% +stuff and do the processing + + + align:start position:0% +stuff and do the processing +computationally ever since the Advent of + + align:start position:0% +computationally ever since the Advent of + + + align:start position:0% +computationally ever since the Advent of +digital electronics it's just much + + align:start position:0% +digital electronics it's just much + + + align:start position:0% +digital electronics it's just much +easier digital one it's just much easier + + align:start position:0% +easier digital one it's just much easier + + + align:start position:0% +easier digital one it's just much easier +to process signals in the in the digital + + align:start position:0% +to process signals in the in the digital + + + align:start position:0% +to process signals in the in the digital +domain so we will often be interested in + + align:start position:0% +domain so we will often be interested in + + + align:start position:0% +domain so we will often be interested in +how do you + + align:start position:0% +how do you + + + align:start position:0% +how do you +represent a signal who naturally lives + + align:start position:0% +represent a signal who naturally lives + + + align:start position:0% +represent a signal who naturally lives +in the physical world and is therefore + + align:start position:0% +in the physical world and is therefore + + + align:start position:0% +in the physical world and is therefore +part at whose signals are continuous in + + align:start position:0% +part at whose signals are continuous in + + + align:start position:0% +part at whose signals are continuous in +nature continuous time how do you + + align:start position:0% +nature continuous time how do you + + + align:start position:0% +nature continuous time how do you +convert it into a discrete + + align:start position:0% +convert it into a discrete + + + align:start position:0% +convert it into a discrete +representation so you can crunch it on a + + align:start position:0% +representation so you can crunch it on a + + + align:start position:0% +representation so you can crunch it on a +computer and in fact how do you go back + + align:start position:0% +computer and in fact how do you go back + + + align:start position:0% +computer and in fact how do you go back +so for + + align:start position:0% +so for + + + align:start position:0% +so for +example if we were thinking about + + align:start position:0% +example if we were thinking about + + + align:start position:0% +example if we were thinking about +processing audio signals we might want + + align:start position:0% +processing audio signals we might want + + + align:start position:0% +processing audio signals we might want +to think about how we would take a + + align:start position:0% +to think about how we would take a + + + align:start position:0% +to think about how we would take a +signal of continuous time and turn it + + align:start position:0% +signal of continuous time and turn it + + + align:start position:0% +signal of continuous time and turn it +into a discrete time + + align:start position:0% +into a discrete time + + + align:start position:0% +into a discrete time +representation that's precisely what we + + align:start position:0% +representation that's precisely what we + + + align:start position:0% +representation that's precisely what we +do when we want to record something in + + align:start position:0% +do when we want to record something in + + + align:start position:0% +do when we want to record something in +mp3 mp3 represents a sound a sound is + + align:start position:0% +mp3 mp3 represents a sound a sound is + + + align:start position:0% +mp3 mp3 represents a sound a sound is +something that I think of as a signal in + + align:start position:0% +something that I think of as a signal in + + + align:start position:0% +something that I think of as a signal in +continuous time it's pascals as a + + align:start position:0% +continuous time it's pascals as a + + + align:start position:0% +continuous time it's pascals as a +function of + + align:start position:0% +function of + + + align:start position:0% +function of +seconds but we want to represent it by a + + align:start position:0% +seconds but we want to represent it by a + + + align:start position:0% +seconds but we want to represent it by a +sequence of numbers because it's a + + align:start position:0% +sequence of numbers because it's a + + + align:start position:0% +sequence of numbers because it's a +sequence of numbers that's easy to store + + align:start position:0% +sequence of numbers that's easy to store + + + align:start position:0% +sequence of numbers that's easy to store +to communicate + + align:start position:0% +to communicate + + + align:start position:0% +to communicate +Etc we do the same sort of thing with + + align:start position:0% +Etc we do the same sort of thing with + + + align:start position:0% +Etc we do the same sort of thing with +images the images of the ear that I + + align:start position:0% +images the images of the ear that I + + + align:start position:0% +images the images of the ear that I +talked about in my research are things + + align:start position:0% +talked about in my research are things + + + align:start position:0% +talked about in my research are things +that I think about happening at + + align:start position:0% +that I think about happening at + + + align:start position:0% +that I think about happening at +continuous + + align:start position:0% +continuous + + + align:start position:0% +continuous +space every time we look at a smaller + + align:start position:0% +space every time we look at a smaller + + + align:start position:0% +space every time we look at a smaller +and smaller Dimension we get a different + + align:start position:0% +and smaller Dimension we get a different + + + align:start position:0% +and smaller Dimension we get a different +answer because the the image has no + + align:start position:0% +answer because the the image has no + + + align:start position:0% +answer because the the image has no +quantization in + + align:start position:0% +quantization in + + + align:start position:0% +quantization in +space but when I crunch it I don't want + + align:start position:0% +space but when I crunch it I don't want + + + align:start position:0% +space but when I crunch it I don't want +to work in something in continuous space + + align:start position:0% +to work in something in continuous space + + + align:start position:0% +to work in something in continuous space +I want to work in a in a sampled version + + align:start position:0% +I want to work in a in a sampled version + + + align:start position:0% +I want to work in a in a sampled version +like a JPEG + + align:start position:0% +like a JPEG + + + align:start position:0% +like a JPEG +version similarly we want to convert + + align:start position:0% +version similarly we want to convert + + + align:start position:0% +version similarly we want to convert +back I mean it would be useless for the + + align:start position:0% +back I mean it would be useless for the + + + align:start position:0% +back I mean it would be useless for the +case of the cell phone to convert it + + align:start position:0% +case of the cell phone to convert it + + + align:start position:0% +case of the cell phone to convert it +into a discrete representation and then + + align:start position:0% +into a discrete representation and then + + + align:start position:0% +into a discrete representation and then +not be able to hear + + align:start position:0% +not be able to hear + + + align:start position:0% +not be able to hear +it so we'll think about the inverse + + align:start position:0% +it so we'll think about the inverse + + + align:start position:0% +it so we'll think about the inverse +process which is reconstruction if you + + align:start position:0% +process which is reconstruction if you + + + align:start position:0% +process which is reconstruction if you +had a discrete representation of a + + align:start position:0% +had a discrete representation of a + + + align:start position:0% +had a discrete representation of a +signal how would you turn it + + align:start position:0% +signal how would you turn it + + + align:start position:0% +signal how would you turn it +into a continuous representation and + + align:start position:0% +into a continuous representation and + + + align:start position:0% +into a continuous representation and +there's lots of ways people do that + + align:start position:0% +there's lots of ways people do that + + + align:start position:0% +there's lots of ways people do that +here's a way that we call zero order + + align:start position:0% +here's a way that we call zero order + + + align:start position:0% +here's a way that we call zero order +hold where you convert every sample into + + align:start position:0% +hold where you convert every sample into + + + align:start position:0% +hold where you convert every sample into +a corresponding + + align:start position:0% +a corresponding + + + align:start position:0% +a corresponding +voltage and just hold that voltage until + + align:start position:0% +voltage and just hold that voltage until + + + align:start position:0% +voltage and just hold that voltage until +the next sample comes along this is the + + align:start position:0% +the next sample comes along this is the + + + align:start position:0% +the next sample comes along this is the +representation that is most commonly + + align:start position:0% +representation that is most commonly + + + align:start position:0% +representation that is most commonly +used in things like + + align:start position:0% + + + + align:start position:0% + +mp3 by contrast we might do something + + align:start position:0% +mp3 by contrast we might do something + + + align:start position:0% +mp3 by contrast we might do something +cleverer we might linearly extrapolate + + align:start position:0% +cleverer we might linearly extrapolate + + + align:start position:0% +cleverer we might linearly extrapolate +between + + align:start position:0% +between + + + align:start position:0% +between +samples that is commonly done in picture + + align:start position:0% +samples that is commonly done in picture + + + align:start position:0% +samples that is commonly done in picture +processing the reason we use the two + + align:start position:0% +processing the reason we use the two + + + align:start position:0% +processing the reason we use the two +different schemes is that + + align:start position:0% +different schemes is that + + + align:start position:0% +different schemes is that +psychophysically the things that are + + align:start position:0% +psychophysically the things that are + + + align:start position:0% +psychophysically the things that are +important to your eyes and the things + + align:start position:0% +important to your eyes and the things + + + align:start position:0% +important to your eyes and the things +that are important to your ears are + + align:start position:0% +that are important to your ears are + + + align:start position:0% +that are important to your ears are +different so you would hear the errors + + align:start position:0% +different so you would hear the errors + + + align:start position:0% +different so you would hear the errors +more if you did the linear interpolation + + align:start position:0% +more if you did the linear interpolation + + + align:start position:0% +more if you did the linear interpolation +and you would see the errors + + align:start position:0% +and you would see the errors + + + align:start position:0% +and you would see the errors +more if you did the other interpolation + + align:start position:0% +more if you did the other interpolation + + + align:start position:0% +more if you did the other interpolation +and we'll do lots of examples later on + + align:start position:0% +and we'll do lots of examples later on + + + align:start position:0% +and we'll do lots of examples later on +in the course so you see why that's + + align:start position:0% + + + + align:start position:0% + +true okay too much talking not enough + + align:start position:0% +true okay too much talking not enough + + + align:start position:0% +true okay too much talking not enough +thinking so I've told you a lot about + + align:start position:0% +thinking so I've told you a lot about + + + align:start position:0% +thinking so I've told you a lot about +signals now I'd like you to think about + + align:start position:0% +signals now I'd like you to think about + + + align:start position:0% +signals now I'd like you to think about +some + + align:start position:0% +some + + + align:start position:0% +some +signals and so a common thing I'm going + + align:start position:0% +signals and so a common thing I'm going + + + align:start position:0% +signals and so a common thing I'm going +to do in this class is ask you to think + + align:start position:0% +to do in this class is ask you to think + + + align:start position:0% +to do in this class is ask you to think +about a question talk to your neighbor + + align:start position:0% +about a question talk to your neighbor + + + align:start position:0% +about a question talk to your neighbor +come to a consensus and then vote so + + align:start position:0% +come to a consensus and then vote so + + + align:start position:0% +come to a consensus and then vote so +that's what we're going to do here I'm + + align:start position:0% +that's what we're going to do here I'm + + + align:start position:0% +that's what we're going to do here I'm +going to play some sounds you're going + + align:start position:0% +going to play some sounds you're going + + + align:start position:0% +going to play some sounds you're going +to try to figure out what signals were + + align:start position:0% +to try to figure out what signals were + + + align:start position:0% +to try to figure out what signals were +represented by those sounds but I would + + align:start position:0% +represented by those sounds but I would + + + align:start position:0% +represented by those sounds but I would +like you to have an opinion before we we + + align:start position:0% +like you to have an opinion before we we + + + align:start position:0% +like you to have an opinion before we we +communicate the answer because you can + + align:start position:0% +communicate the answer because you can + + + align:start position:0% +communicate the answer because you can +prove that people get more out of it + + align:start position:0% +prove that people get more out of it + + + align:start position:0% +prove that people get more out of it +when there's something at stake so I + + align:start position:0% +when there's something at stake so I + + + align:start position:0% +when there's something at stake so I +would like you to work with a partner so + + align:start position:0% +would like you to work with a partner so + + + align:start position:0% +would like you to work with a partner so +in order to work with a partner + + align:start position:0% +in order to work with a partner + + + align:start position:0% +in order to work with a partner +everybody stand up introduce yourself to + + align:start position:0% +everybody stand up introduce yourself to + + + align:start position:0% +everybody stand up introduce yourself to +your neighbor figure out a good partner + + align:start position:0% +your neighbor figure out a good partner + + + align:start position:0% +your neighbor figure out a good partner +figure out where they + + align:start position:0% + + + + align:start position:0% + +live + + align:start position:0% + + + + align:start position:0% + +okay so what I'm I'm going to do + + align:start position:0% +okay so what I'm I'm going to do + + + align:start position:0% +okay so what I'm I'm going to do +now is play a computer generated sound + + align:start position:0% +now is play a computer generated sound + + + align:start position:0% +now is play a computer generated sound +this is a computerated computer + + align:start position:0% +this is a computerated computer + + + align:start position:0% +this is a computerated computer +generated speech sound made by Bob + + align:start position:0% +generated speech sound made by Bob + + + align:start position:0% +generated speech sound made by Bob +Donovan who did his PhD thesis figuring + + align:start position:0% +Donovan who did his PhD thesis figuring + + + align:start position:0% +Donovan who did his PhD thesis figuring +out how to do computer generated + + align:start position:0% +out how to do computer generated + + + align:start position:0% +out how to do computer generated +speech and then I'm going to play Four + + align:start position:0% +speech and then I'm going to play Four + + + align:start position:0% +speech and then I'm going to play Four +transformations of that + + align:start position:0% +transformations of that + + + align:start position:0% +transformations of that +sound and the your task is to identify + + align:start position:0% +sound and the your task is to identify + + + align:start position:0% +sound and the your task is to identify +what's the mathematical representation + + align:start position:0% +what's the mathematical representation + + + align:start position:0% +what's the mathematical representation +of the Transformations that I'm telling + + align:start position:0% +of the Transformations that I'm telling + + + align:start position:0% +of the Transformations that I'm telling +you okay so first the original + + align:start position:0% +you okay so first the original + + + align:start position:0% +you okay so first the original +first is the signal that Bob Donovan + + align:start position:0% + + + + align:start position:0% + +MaDee and now I'm going to play a + + align:start position:0% +MaDee and now I'm going to play a + + + align:start position:0% +MaDee and now I'm going to play a +sequence of four + + align:start position:0% +sequence of four + + + align:start position:0% +sequence of four +Transformations 1 2 3 four and the + + align:start position:0% +Transformations 1 2 3 four and the + + + align:start position:0% +Transformations 1 2 3 four and the +question is going to be is this the ma + + align:start position:0% +question is going to be is this the ma + + + align:start position:0% +question is going to be is this the ma +the correct mathematical representation + + align:start position:0% +the correct mathematical representation + + + align:start position:0% +the correct mathematical representation +for this sound the sound you just heard + + align:start position:0% +for this sound the sound you just heard + + + align:start position:0% +for this sound the sound you just heard +was F of t + + align:start position:0% +was F of t + + + align:start position:0% +was F of t +is the following sound which by + + align:start position:0% +is the following sound which by + + + align:start position:0% +is the following sound which by +definition is + + align:start position:0% +definition is + + + align:start position:0% +definition is +F1 the same as F of + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +2T you're allowed to + + align:start position:0% + + + + align:start position:0% + +talk + + align:start position:0% + + + + align:start position:0% + +e + + align:start position:0% + + + + align:start position:0% + +okay remember that answer now is the + + align:start position:0% +okay remember that answer now is the + + + align:start position:0% +okay remember that answer now is the +following sound minus F + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% + + + + align:start position:0% + +okay remember that answer is the + + align:start position:0% +okay remember that answer is the + + + align:start position:0% +okay remember that answer is the +following sound F of + + align:start position:0% + + + + align:start position:0% + +2T + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +finally is the following signal oneir of + + align:start position:0% +finally is the following signal oneir of + + + align:start position:0% +finally is the following signal oneir of +f of + + align:start position:0% + + + + align:start position:0% + +te okay conver confer with your + + align:start position:0% +te okay conver confer with your + + + align:start position:0% +te okay conver confer with your +partner figure out how many are true + + align:start position:0% +partner figure out how many are true + + + align:start position:0% +partner figure out how many are true +because in 30 seconds I'm going to ask + + align:start position:0% +because in 30 seconds I'm going to ask + + + align:start position:0% +because in 30 seconds I'm going to ask +you to raise your + + align:start position:0% + + + + align:start position:0% + +hand + + align:start position:0% + + + + align:start position:0% + +question + + align:start position:0% +question + + + align:start position:0% +question +or fft was the original + + align:start position:0% + + + + align:start position:0% + +signal uh + + align:start position:0% +signal uh + + + align:start position:0% +signal uh +pressure pressure in the acoustic + + align:start position:0% +pressure pressure in the acoustic + + + align:start position:0% +pressure pressure in the acoustic +waveform + + align:start position:0% + + + + align:start position:0% + +that's + + align:start position:0% + + + + align:start position:0% + +true okay how many of those statements + + align:start position:0% +true okay how many of those statements + + + align:start position:0% +true okay how many of those statements +are true raise your hand with some + + align:start position:0% +are true raise your hand with some + + + align:start position:0% +are true raise your hand with some +number of fingers keeping in mind that + + align:start position:0% +number of fingers keeping in mind that + + + align:start position:0% +number of fingers keeping in mind that +you're voting having collaborated with + + align:start position:0% +you're voting having collaborated with + + + align:start position:0% +you're voting having collaborated with +your partner so it's not your fault you + + align:start position:0% +your partner so it's not your fault you + + + align:start position:0% +your partner so it's not your fault you +have a right anyway okay so how many so + + align:start position:0% +have a right anyway okay so how many so + + + align:start position:0% +have a right anyway okay so how many so +everybody raise your hands I want to + + align:start position:0% + + + + align:start position:0% + +see okay it's about 90% no less than + + align:start position:0% +see okay it's about 90% no less than + + + align:start position:0% +see okay it's about 90% no less than +that about 85% correct okay uh so first + + align:start position:0% +that about 85% correct okay uh so first + + + align:start position:0% +that about 85% correct okay uh so first +one was that F of + + align:start position:0% +one was that F of + + + align:start position:0% +one was that F of +2T why do you think that everybody seems + + align:start position:0% +2T why do you think that everybody seems + + + align:start position:0% +2T why do you think that everybody seems +to be saying + + align:start position:0% +to be saying + + + align:start position:0% +to be saying +yes it was fast it sounded faster so + + align:start position:0% +yes it was fast it sounded faster so + + + align:start position:0% +yes it was fast it sounded faster so +what's faster mean from a signal point + + align:start position:0% +what's faster mean from a signal point + + + align:start position:0% +what's faster mean from a signal point +of + + align:start position:0% + + + + align:start position:0% + +view change the time scales that's a + + align:start position:0% +view change the time scales that's a + + + align:start position:0% +view change the time scales that's a +very good way of thinking about it so if + + align:start position:0% +very good way of thinking about it so if + + + align:start position:0% +very good way of thinking about it so if +we thought about if we made a simple + + align:start position:0% +we thought about if we made a simple + + + align:start position:0% +we thought about if we made a simple +representation for + + align:start position:0% +representation for + + + align:start position:0% +representation for +f ignore what it really is let's say + + align:start position:0% +f ignore what it really is let's say + + + align:start position:0% +f ignore what it really is let's say +it's + + align:start position:0% +it's + + + align:start position:0% +it's +that what would F1 look like in order to + + align:start position:0% +that what would F1 look like in order to + + + align:start position:0% +that what would F1 look like in order to +make it sound + + align:start position:0% + + + + align:start position:0% + +faster okay we have people doing this + + align:start position:0% +faster okay we have people doing this + + + align:start position:0% +faster okay we have people doing this +and we have people doing this and I'm + + align:start position:0% +and we have people doing this and I'm + + + align:start position:0% +and we have people doing this and I'm +not quite sure what that means so could + + align:start position:0% +not quite sure what that means so could + + + align:start position:0% +not quite sure what that means so could +somebody be a little more + + align:start position:0% +somebody be a little more + + + align:start position:0% +somebody be a little more +descriptive hand gestures are fine yes + + align:start position:0% +descriptive hand gestures are fine yes + + + align:start position:0% +descriptive hand gestures are fine yes +squished squished exactly right so what + + align:start position:0% +squished squished exactly right so what + + + align:start position:0% +squished squished exactly right so what +we want to have happen + + align:start position:0% +we want to have happen + + + align:start position:0% +we want to have happen +in order to sound faster we want to have + + align:start position:0% +in order to sound faster we want to have + + + align:start position:0% +in order to sound faster we want to have +it come out faster so we would like that + + align:start position:0% +it come out faster so we would like that + + + align:start position:0% +it come out faster so we would like that +to happen to it so it's all over in one + + align:start position:0% +to happen to it so it's all over in one + + + align:start position:0% +to happen to it so it's all over in one +second if the original was all over in + + align:start position:0% +second if the original was all over in + + + align:start position:0% +second if the original was all over in +two seconds right that's what faster + + align:start position:0% +two seconds right that's what faster + + + align:start position:0% +two seconds right that's what faster +means so we would like that to be true + + align:start position:0% +means so we would like that to be true + + + align:start position:0% +means so we would like that to be true +is that what's going on in that + + align:start position:0% +is that what's going on in that + + + align:start position:0% +is that what's going on in that +function + + align:start position:0% +function + + + align:start position:0% +function +yeah okay so that's right second + + align:start position:0% +yeah okay so that's right second + + + align:start position:0% +yeah okay so that's right second +one + + align:start position:0% +one + + + align:start position:0% +one +yes + + align:start position:0% +yes + + + align:start position:0% +yes +and that also makes it higher pitched in + + align:start position:0% +and that also makes it higher pitched in + + + align:start position:0% +and that also makes it higher pitched in +fact we will talk a lot about this later + + align:start position:0% +fact we will talk a lot about this later + + + align:start position:0% +fact we will talk a lot about this later +but pitch has to do with a related kind + + align:start position:0% +but pitch has to do with a related kind + + + align:start position:0% +but pitch has to do with a related kind +of waveform if I thought about a + + align:start position:0% +of waveform if I thought about a + + + align:start position:0% +of waveform if I thought about a +waveform that was a single + + align:start position:0% +waveform that was a single + + + align:start position:0% +waveform that was a single +tone that might look like + + align:start position:0% +tone that might look like + + + align:start position:0% +tone that might look like +this so if you were to play an + + align:start position:0% +this so if you were to play an + + + align:start position:0% +this so if you were to play an +OBO and play Just A C constantly you get + + align:start position:0% +OBO and play Just A C constantly you get + + + align:start position:0% +OBO and play Just A C constantly you get +some periodic + + align:start position:0% +some periodic + + + align:start position:0% +some periodic +waveform if I did the same + + align:start position:0% +waveform if I did the same + + + align:start position:0% +waveform if I did the same +transformation on that periodic wave + + align:start position:0% +transformation on that periodic wave + + + align:start position:0% +transformation on that periodic wave +form what would happen to that waveform + + align:start position:0% +form what would happen to that waveform + + + align:start position:0% +form what would happen to that waveform +what would happen to this if I did + + align:start position:0% +what would happen to this if I did + + + align:start position:0% +what would happen to this if I did +transformation + + align:start position:0% +transformation + + + align:start position:0% +transformation +one squish what's squish + + align:start position:0% +one squish what's squish + + + align:start position:0% +one squish what's squish +being more High higher frequency more + + align:start position:0% +being more High higher frequency more + + + align:start position:0% +being more High higher frequency more +cycles per second yeah so how you make + + align:start position:0% +cycles per second yeah so how you make + + + align:start position:0% +cycles per second yeah so how you make +the same go as fast have the same that's + + align:start position:0% +the same go as fast have the same that's + + + align:start position:0% +the same go as fast have the same that's +very hard in fact I worked on that as a + + align:start position:0% +very hard in fact I worked on that as a + + + align:start position:0% +very hard in fact I worked on that as a +research project um so one of the + + align:start position:0% +research project um so one of the + + + align:start position:0% +research project um so one of the +techniques that we use to try to fix + + align:start position:0% +techniques that we use to try to fix + + + align:start position:0% +techniques that we use to try to fix +people's + + align:start position:0% +people's + + + align:start position:0% +people's +ears uh it turns out that people who + + align:start position:0% +ears uh it turns out that people who + + + align:start position:0% +ears uh it turns out that people who +have hearing disorders like + + align:start position:0% +have hearing disorders like + + + align:start position:0% +have hearing disorders like +mine can more easily understand male + + align:start position:0% +mine can more easily understand male + + + align:start position:0% +mine can more easily understand male +speech than female speech just because + + align:start position:0% +speech than female speech just because + + + align:start position:0% +speech than female speech just because +of the shift in frequencies male speech + + align:start position:0% +of the shift in frequencies male speech + + + align:start position:0% +of the shift in frequencies male speech +is primarily about an octave lower on + + align:start position:0% +is primarily about an octave lower on + + + align:start position:0% +is primarily about an octave lower on +average than female speech so we tried + + align:start position:0% +average than female speech so we tried + + + align:start position:0% +average than female speech so we tried +to convert every female into a male + + align:start position:0% +to convert every female into a male + + + align:start position:0% +to convert every female into a male +speaker and every male into the Jolly + + align:start position:0% +speaker and every male into the Jolly + + + align:start position:0% +speaker and every male into the Jolly +Green + + align:start position:0% +Green + + + align:start position:0% +Green +Giant and it worked males sounded like + + align:start position:0% +Giant and it worked males sounded like + + + align:start position:0% +Giant and it worked males sounded like +the Jolly Green Giant and females + + align:start position:0% +the Jolly Green Giant and females + + + align:start position:0% +the Jolly Green Giant and females +sounded like males and it didn't help + + align:start position:0% +sounded like males and it didn't help + + + align:start position:0% +sounded like males and it didn't help +hearing at all and that's primarily + + align:start position:0% +hearing at all and that's primarily + + + align:start position:0% +hearing at all and that's primarily +because it's a hard problem so but we + + align:start position:0% +because it's a hard problem so but we + + + align:start position:0% +because it's a hard problem so but we +will say more about that as we go on + + align:start position:0% +will say more about that as we go on + + + align:start position:0% +will say more about that as we go on +through the course but is a hard + + align:start position:0% +through the course but is a hard + + + align:start position:0% +through the course but is a hard +problem because you end up having to do + + align:start position:0% +problem because you end up having to do + + + align:start position:0% +problem because you end up having to do +other than just + + align:start position:0% +other than just + + + align:start position:0% +other than just +squish + + align:start position:0% +squish + + + align:start position:0% +squish +okay second one is this the right + + align:start position:0% +okay second one is this the right + + + align:start position:0% +okay second one is this the right +transformation no why + + align:start position:0% +transformation no why + + + align:start position:0% +transformation no why +not + + align:start position:0% + + + + align:start position:0% + +yeah if you flipped over the + + align:start position:0% +yeah if you flipped over the + + + align:start position:0% +yeah if you flipped over the +amplitude so what it's so flip over the + + align:start position:0% +amplitude so what it's so flip over the + + + align:start position:0% +amplitude so what it's so flip over the +amplitude you're saying that didn't do + + align:start position:0% +amplitude you're saying that didn't do + + + align:start position:0% +amplitude you're saying that didn't do +it what what was the transformation if + + align:start position:0% +it what what was the transformation if + + + align:start position:0% +it what what was the transformation if +it wasn't flip over the amplitude what + + align:start position:0% +it wasn't flip over the amplitude what + + + align:start position:0% +it wasn't flip over the amplitude what +is it + + align:start position:0% +is it + + + align:start position:0% +is it +yeah F of minus t it was flipped this + + align:start position:0% +yeah F of minus t it was flipped this + + + align:start position:0% +yeah F of minus t it was flipped this +way right flipping this way is largely + + align:start position:0% +way right flipping this way is largely + + + align:start position:0% +way right flipping this way is largely +inaudible if you had a pressure wave + + align:start position:0% +inaudible if you had a pressure wave + + + align:start position:0% +inaudible if you had a pressure wave +form versus a rare faction waveform + + align:start position:0% +form versus a rare faction waveform + + + align:start position:0% +form versus a rare faction waveform +positive pressures versus negative + + align:start position:0% +positive pressures versus negative + + + align:start position:0% +positive pressures versus negative +pressures this is very hard to tell not + + align:start position:0% +pressures this is very hard to tell not + + + align:start position:0% +pressures this is very hard to tell not +impossible if you're one of those audio + + align:start position:0% +impossible if you're one of those audio + + + align:start position:0% +impossible if you're one of those audio +types like me you can probably hear the + + align:start position:0% +types like me you can probably hear the + + + align:start position:0% +types like me you can probably hear the +difference but it's very hard hearing + + align:start position:0% +difference but it's very hard hearing + + + align:start position:0% +difference but it's very hard hearing +this not + + align:start position:0% +this not + + + align:start position:0% +this not +hard okay uh how about this + + align:start position:0% + + + + align:start position:0% + +one obviously wrong because this one was + + align:start position:0% +one obviously wrong because this one was + + + align:start position:0% +one obviously wrong because this one was +right okay how about this + + align:start position:0% +right okay how about this + + + align:start position:0% +right okay how about this +one yeah so the idea was that um there + + align:start position:0% +one yeah so the idea was that um there + + + align:start position:0% +one yeah so the idea was that um there +were two that were correct so the 85% of + + align:start position:0% +were two that were correct so the 85% of + + + align:start position:0% +were two that were correct so the 85% of +you or so who got two presumably you got + + align:start position:0% +you or so who got two presumably you got + + + align:start position:0% +you or so who got two presumably you got +the right two right the bet I won't ask + + align:start position:0% +the right two right the bet I won't ask + + + align:start position:0% +the right two right the bet I won't ask +um okay here's a here's a an image + + align:start position:0% +um okay here's a here's a an image + + + align:start position:0% +um okay here's a here's a an image +processing + + align:start position:0% +processing + + + align:start position:0% +processing +question think about this picture of + + align:start position:0% +question think about this picture of + + + align:start position:0% +question think about this picture of +sta I know it's hard to think about + + align:start position:0% +sta I know it's hard to think about + + + align:start position:0% +sta I know it's hard to think about +pictures of sta that's + + align:start position:0% +pictures of sta that's + + + align:start position:0% +pictures of sta that's +okay think about this picture of sta + + align:start position:0% +okay think about this picture of sta + + + align:start position:0% +okay think about this picture of sta +I've indexed XM Y and I've written that + + align:start position:0% +I've indexed XM Y and I've written that + + + align:start position:0% +I've indexed XM Y and I've written that +as f a signal that depends on two + + align:start position:0% +as f a signal that depends on two + + + align:start position:0% +as f a signal that depends on two +independent variables XM + + align:start position:0% +independent variables XM + + + align:start position:0% +independent variables XM +Y and I've got three Transformations the + + align:start position:0% +Y and I've got three Transformations the + + + align:start position:0% +Y and I've got three Transformations the +F1 transformation the F2 and the + + align:start position:0% + + + + align:start position:0% + +F3 the question is is this the right + + align:start position:0% +F3 the question is is this the right + + + align:start position:0% +F3 the question is is this the right +mathematical + + align:start position:0% +mathematical + + + align:start position:0% +mathematical +representation for transforming that + + align:start position:0% +representation for transforming that + + + align:start position:0% +representation for transforming that +picture into this + + align:start position:0% +picture into this + + + align:start position:0% +picture into this +one is this the one for that one and is + + align:start position:0% +one is this the one for that one and is + + + align:start position:0% +one is this the one for that one and is +is this a representation for this one is + + align:start position:0% +is this a representation for this one is + + + align:start position:0% +is this a representation for this one is +this a representation for that one take + + align:start position:0% +this a representation for that one take + + + align:start position:0% +this a representation for that one take +30 seconds talk to your partner and and + + align:start position:0% +30 seconds talk to your partner and and + + + align:start position:0% +30 seconds talk to your partner and and +figure out how many of those + + align:start position:0% +figure out how many of those + + + align:start position:0% +figure out how many of those +Transformations are + + align:start position:0% + + + + align:start position:0% + +correct + + align:start position:0% + + + + align:start position:0% + +e + + align:start position:0% + + + + align:start position:0% + +okay so how many of the Transformations + + align:start position:0% +okay so how many of the Transformations + + + align:start position:0% +okay so how many of the Transformations +are correct raise your + + align:start position:0% +are correct raise your + + + align:start position:0% +are correct raise your +hand everybody raise your + + align:start position:0% +hand everybody raise your + + + align:start position:0% +hand everybody raise your +hand oh + + align:start position:0% +hand oh + + + align:start position:0% +hand oh +uh it's a zero or three okay just + + align:start position:0% +uh it's a zero or three okay just + + + align:start position:0% +uh it's a zero or three okay just +checking okay about 85% correct again + + align:start position:0% +checking okay about 85% correct again + + + align:start position:0% +checking okay about 85% correct again +okay probably a different 85% um so how + + align:start position:0% +okay probably a different 85% um so how + + + align:start position:0% +okay probably a different 85% um so how +do you think about this problem so + + align:start position:0% +do you think about this problem so + + + align:start position:0% +do you think about this problem so +there's a variety of ways you could + + align:start position:0% +there's a variety of ways you could + + + align:start position:0% +there's a variety of ways you could +think about + + align:start position:0% +think about + + + align:start position:0% +think about +it let me show you a way that focuses on + + align:start position:0% +it let me show you a way that focuses on + + + align:start position:0% +it let me show you a way that focuses on +an idea called mapping because I think + + align:start position:0% +an idea called mapping because I think + + + align:start position:0% +an idea called mapping because I think +is a very powerful way so if you think + + align:start position:0% +is a very powerful way so if you think + + + align:start position:0% +is a very powerful way so if you think +about a map how does the how does the T + + align:start position:0% +about a map how does the how does the T + + + align:start position:0% +about a map how does the how does the T +variable in the first problem map to the + + align:start position:0% +variable in the first problem map to the + + + align:start position:0% +variable in the first problem map to the +T variable in the second + + align:start position:0% +T variable in the second + + + align:start position:0% +T variable in the second +problem so a way you can think about + + align:start position:0% +problem so a way you can think about + + + align:start position:0% +problem so a way you can think about +this is if this is true for um all X and + + align:start position:0% +this is if this is true for um all X and + + + align:start position:0% +this is if this is true for um all X and +Y it's true for particular X so let's + + align:start position:0% +Y it's true for particular X so let's + + + align:start position:0% +Y it's true for particular X so let's +ask is it true for x equals + + align:start position:0% +ask is it true for x equals + + + align:start position:0% +ask is it true for x equals +z so how does the point x equals 0 map + + align:start position:0% +z so how does the point x equals 0 map + + + align:start position:0% +z so how does the point x equals 0 map +from one image to another so if you + + align:start position:0% +from one image to another so if you + + + align:start position:0% +from one image to another so if you +substitute at x equals 0 then F1 of0 so + + align:start position:0% +substitute at x equals 0 then F1 of0 so + + + align:start position:0% +substitute at x equals 0 then F1 of0 so +if you look at uh this + + align:start position:0% +if you look at uh this + + + align:start position:0% +if you look at uh this +transformation the claim would be that + + align:start position:0% +transformation the claim would be that + + + align:start position:0% +transformation the claim would be that +fub1 of0 is the same as F of + + align:start position:0% +fub1 of0 is the same as F of + + + align:start position:0% +fub1 of0 is the same as F of +zero is that + + align:start position:0% + + + + align:start position:0% + +true so F1 of + + align:start position:0% +true so F1 of + + + align:start position:0% +true so F1 of +zero bcts + + align:start position:0% + + + + align:start position:0% + +sta F of Z bisects + + align:start position:0% +sta F of Z bisects + + + align:start position:0% +sta F of Z bisects +Theta so yeah that's the right thing + + align:start position:0% +Theta so yeah that's the right thing + + + align:start position:0% +Theta so yeah that's the right thing +everybody see + + align:start position:0% +everybody see + + + align:start position:0% +everybody see +that is the statement true for xal + + align:start position:0% +that is the statement true for xal + + + align:start position:0% +that is the statement true for xal +250 well F1 of + + align:start position:0% +250 well F1 of + + + align:start position:0% +250 well F1 of +250 so F1 of + + align:start position:0% +250 so F1 of + + + align:start position:0% +250 so F1 of +250 is + + align:start position:0% +250 is + + + align:start position:0% +250 is +through uh the right hand side of + + align:start position:0% +through uh the right hand side of + + + align:start position:0% +through uh the right hand side of +sta sort of where the steel and the + + align:start position:0% +sta sort of where the steel and the + + + align:start position:0% +sta sort of where the steel and the +bricks come + + align:start position:0% +bricks come + + + align:start position:0% +bricks come +together is that the same as + + align:start position:0% +together is that the same as + + + align:start position:0% +together is that the same as +substituting in here if x is 250 then F + + align:start position:0% +substituting in here if x is 250 then F + + + align:start position:0% +substituting in here if x is 250 then F +of 500 + + align:start position:0% +of 500 + + + align:start position:0% +of 500 +F of 500 is off the screen so is that + + align:start position:0% +F of 500 is off the screen so is that + + + align:start position:0% +F of 500 is off the screen so is that +transformation hold at the point xal 250 + + align:start position:0% +transformation hold at the point xal 250 + + + align:start position:0% +transformation hold at the point xal 250 +no okay it can't be right okay one one + + align:start position:0% +no okay it can't be right okay one one + + + align:start position:0% +no okay it can't be right okay one one +bad sample proves that it can't be the + + align:start position:0% +bad sample proves that it can't be the + + + align:start position:0% +bad sample proves that it can't be the +general + + align:start position:0% +general + + + align:start position:0% +general +transformation okay everybody see + + align:start position:0% +transformation okay everybody see + + + align:start position:0% +transformation okay everybody see +that similarly for the second + + align:start position:0% +that similarly for the second + + + align:start position:0% +that similarly for the second +transformation let's just try some + + align:start position:0% +transformation let's just try some + + + align:start position:0% +transformation let's just try some +points if we try the point xal + + align:start position:0% +points if we try the point xal + + + align:start position:0% +points if we try the point xal +0 this says that F2 at location Z should + + align:start position:0% +0 this says that F2 at location Z should + + + align:start position:0% +0 this says that F2 at location Z should +be F at location minus + + align:start position:0% +be F at location minus + + + align:start position:0% +be F at location minus +250 is that + + align:start position:0% + + + + align:start position:0% + +correct so F of zero well that's the + + align:start position:0% +correct so F of zero well that's the + + + align:start position:0% +correct so F of zero well that's the +left hand side of + + align:start position:0% +left hand side of + + + align:start position:0% +left hand side of +theta and so F2 of Zer that's the left + + align:start position:0% +theta and so F2 of Zer that's the left + + + align:start position:0% +theta and so F2 of Zer that's the left +hand side of theta F of 2 * + + align:start position:0% +hand side of theta F of 2 * + + + align:start position:0% +hand side of theta F of 2 * +0 minus 250 IS F of 250 minus 250 that's + + align:start position:0% +0 minus 250 IS F of 250 minus 250 that's + + + align:start position:0% +0 minus 250 IS F of 250 minus 250 that's +also the left of sta + + align:start position:0% +also the left of sta + + + align:start position:0% +also the left of sta +okay so by using that reasoning you can + + align:start position:0% +okay so by using that reasoning you can + + + align:start position:0% +okay so by using that reasoning you can +go through and see if certain points map + + align:start position:0% +go through and see if certain points map + + + align:start position:0% +go through and see if certain points map +to the corresponding place where they + + align:start position:0% +to the corresponding place where they + + + align:start position:0% +to the corresponding place where they +were supposed to go that's the idea of + + align:start position:0% +were supposed to go that's the idea of + + + align:start position:0% +were supposed to go that's the idea of +mapping and in this particular case if + + align:start position:0% +mapping and in this particular case if + + + align:start position:0% +mapping and in this particular case if +we Trace two + + align:start position:0% +we Trace two + + + align:start position:0% +we Trace two +points and the map 2x - 250 is a linear + + align:start position:0% +points and the map 2x - 250 is a linear + + + align:start position:0% +points and the map 2x - 250 is a linear +function of + + align:start position:0% +function of + + + align:start position:0% +function of +X so two points determine a straight + + align:start position:0% +X so two points determine a straight + + + align:start position:0% +X so two points determine a straight +line so after you've determined two two + + align:start position:0% +line so after you've determined two two + + + align:start position:0% +line so after you've determined two two +points you're + + align:start position:0% +points you're + + + align:start position:0% +points you're +done seem seem + + align:start position:0% +done seem seem + + + align:start position:0% +done seem seem +right so similarly you can figure out + + align:start position:0% +right so similarly you can figure out + + + align:start position:0% +right so similarly you can figure out +that the particular points didn't work + + align:start position:0% +that the particular points didn't work + + + align:start position:0% +that the particular points didn't work +here and so the answer is that only one + + align:start position:0% +here and so the answer is that only one + + + align:start position:0% +here and so the answer is that only one +of those Transformations was + + align:start position:0% + + + + align:start position:0% + +right okay so I spent a fair amount of + + align:start position:0% +right okay so I spent a fair amount of + + + align:start position:0% +right okay so I spent a fair amount of +time on S signals in the last minute oh + + align:start position:0% +time on S signals in the last minute oh + + + align:start position:0% +time on S signals in the last minute oh +minute no I'm not going to do that am I + + align:start position:0% +minute no I'm not going to do that am I + + + align:start position:0% +minute no I'm not going to do that am I +okay I spent a fair amount of time + + align:start position:0% +okay I spent a fair amount of time + + + align:start position:0% +okay I spent a fair amount of time +talking about signals next + + align:start position:0% +talking about signals next + + + align:start position:0% +talking about signals next +time we'll talk about + + align:start position:0% +time we'll talk about + + + align:start position:0% +time we'll talk about +similar ways of thinking about simple + + align:start position:0% +similar ways of thinking about simple + + + align:start position:0% +similar ways of thinking about simple +systems so have a good + + align:start position:0% + + + + align:start position:0% + +weekend \ No newline at end of file diff --git a/-OQn43ZA2EM.txt b/-OQn43ZA2EM.txt new file mode 100644 index 0000000000000000000000000000000000000000..54b93aaae4370577b7bebc82229e0fc8f9315a25 --- /dev/null +++ b/-OQn43ZA2EM.txt @@ -0,0 +1,4451 @@ +align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +e + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +n + + align:start position:0% +n + + + align:start position:0% +n +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +first project was in the Cory Jan + + align:start position:0% +first project was in the Cory Jan + + + align:start position:0% +first project was in the Cory Jan +explained um my design proposal I found + + align:start position:0% +explained um my design proposal I found + + + align:start position:0% +explained um my design proposal I found +a kind of a sloping uh Rock area that + + align:start position:0% +a kind of a sloping uh Rock area that + + + align:start position:0% +a kind of a sloping uh Rock area that +had many little nooks and crannies of + + align:start position:0% +had many little nooks and crannies of + + + align:start position:0% +had many little nooks and crannies of +different sizes for people to gather uh + + align:start position:0% +different sizes for people to gather uh + + + align:start position:0% +different sizes for people to gather uh +in different amount like different + + align:start position:0% +in different amount like different + + + align:start position:0% +in different amount like different +numbers of people um and I kind of just + + align:start position:0% +numbers of people um and I kind of just + + + align:start position:0% +numbers of people um and I kind of just +uh covered them appropriate + + align:start position:0% +uh covered them appropriate + + + align:start position:0% +uh covered them appropriate +appropriately like to what I thought + + align:start position:0% +appropriately like to what I thought + + + align:start position:0% +appropriately like to what I thought +their use would best be um I showed it's + + align:start position:0% +their use would best be um I showed it's + + + align:start position:0% +their use would best be um I showed it's +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +a 3D plan in a way um and + + align:start position:0% +a 3D plan in a way um and + + + align:start position:0% +a 3D plan in a way um and +section uh that project I was having fun + + align:start position:0% +section uh that project I was having fun + + + align:start position:0% +section uh that project I was having fun +it was really quick project and ended up + + align:start position:0% +it was really quick project and ended up + + + align:start position:0% +it was really quick project and ended up +just being kind of fun uh the second + + align:start position:0% +just being kind of fun uh the second + + + align:start position:0% +just being kind of fun uh the second +project + + align:start position:0% +project + + + align:start position:0% +project +uh I got a rooftop design in one corner + + align:start position:0% +uh I got a rooftop design in one corner + + + align:start position:0% +uh I got a rooftop design in one corner +of the North End and was kind of a key + + align:start position:0% +of the North End and was kind of a key + + + align:start position:0% +of the North End and was kind of a key +position I watched over everybody all + + align:start position:0% +position I watched over everybody all + + + align:start position:0% +position I watched over everybody all +the other people in the North End so I + + align:start position:0% +the other people in the North End so I + + + align:start position:0% +the other people in the North End so I +wanted to kind of take advantage of that + + align:start position:0% +wanted to kind of take advantage of that + + + align:start position:0% +wanted to kind of take advantage of that +and do my duty and get kind of high up + + align:start position:0% +and do my duty and get kind of high up + + + align:start position:0% +and do my duty and get kind of high up +um and look out over everyone and uh I + + align:start position:0% +um and look out over everyone and uh I + + + align:start position:0% +um and look out over everyone and uh I +had one wall kind of blocking my view of + + align:start position:0% +had one wall kind of blocking my view of + + + align:start position:0% +had one wall kind of blocking my view of +the city the other side and so I just + + align:start position:0% +the city the other side and so I just + + + align:start position:0% +the city the other side and so I just +rose up above that as well and + + align:start position:0% +rose up above that as well and + + + align:start position:0% +rose up above that as well and +uh that was kind of an interesting + + align:start position:0% +uh that was kind of an interesting + + + align:start position:0% +uh that was kind of an interesting +project because um we had to look at + + align:start position:0% +project because um we had to look at + + + align:start position:0% +project because um we had to look at +where we were going to be in 10 years + + align:start position:0% +where we were going to be in 10 years + + + align:start position:0% +where we were going to be in 10 years +and so I imagin myself married and uh + + align:start position:0% +and so I imagin myself married and uh + + + align:start position:0% +and so I imagin myself married and uh +probably an architect and um I don't + + align:start position:0% +probably an architect and um I don't + + + align:start position:0% +probably an architect and um I don't +know it was just kind of interesting I + + align:start position:0% +know it was just kind of interesting I + + + align:start position:0% +know it was just kind of interesting I +like the way Jen kind of presented it it + + align:start position:0% +like the way Jen kind of presented it it + + + align:start position:0% +like the way Jen kind of presented it it +makes you kind of think ahead and lost a + + align:start position:0% +makes you kind of think ahead and lost a + + + align:start position:0% +makes you kind of think ahead and lost a +lot of weight I see on the roof + + align:start position:0% + + + + align:start position:0% + +yeah yes all right and then uh a third + + align:start position:0% +yeah yes all right and then uh a third + + + align:start position:0% +yeah yes all right and then uh a third +project was more in depth we had at + + align:start position:0% +project was more in depth we had at + + + align:start position:0% +project was more in depth we had at +least twice the time um + + align:start position:0% +least twice the time um + + + align:start position:0% +least twice the time um +for this so we we started out with the + + align:start position:0% +for this so we we started out with the + + + align:start position:0% +for this so we we started out with the +classic junk model or found objects + + align:start position:0% +classic junk model or found objects + + + align:start position:0% +classic junk model or found objects +model um he wanted us to get an idea of + + align:start position:0% +model um he wanted us to get an idea of + + + align:start position:0% +model um he wanted us to get an idea of +uh form and not necessarily use like uh + + align:start position:0% +uh form and not necessarily use like uh + + + align:start position:0% +uh form and not necessarily use like uh +just play with the junk and see what + + align:start position:0% +just play with the junk and see what + + + align:start position:0% +just play with the junk and see what +comes out of it and I this was the + + align:start position:0% +comes out of it and I this was the + + + align:start position:0% +comes out of it and I this was the +funnest project for me a lot of people + + align:start position:0% +funnest project for me a lot of people + + + align:start position:0% +funnest project for me a lot of people +struggled with it like and they love + + align:start position:0% +struggled with it like and they love + + + align:start position:0% +struggled with it like and they love +building regular models and I this is + + align:start position:0% +building regular models and I this is + + + align:start position:0% +building regular models and I this is +this is it for me this is amazing I I + + align:start position:0% +this is it for me this is amazing I I + + + align:start position:0% +this is it for me this is amazing I I +love it uh so I just kind of played with + + align:start position:0% +love it uh so I just kind of played with + + + align:start position:0% +love it uh so I just kind of played with +with junk and thought about like people + + align:start position:0% +with junk and thought about like people + + + align:start position:0% +with junk and thought about like people +are going to be coming um main traffic + + align:start position:0% +are going to be coming um main traffic + + + align:start position:0% +are going to be coming um main traffic +from the North End is coming in here and + + align:start position:0% +from the North End is coming in here and + + + align:start position:0% +from the North End is coming in here and +my main idea was just to to attract + + align:start position:0% +my main idea was just to to attract + + + align:start position:0% +my main idea was just to to attract +people in and so I made I found this on + + align:start position:0% +people in and so I made I found this on + + + align:start position:0% +people in and so I made I found this on +the side and + + align:start position:0% +the side and + + + align:start position:0% +the side and +so I had to I had to put it in there + + align:start position:0% +so I had to I had to put it in there + + + align:start position:0% +so I had to I had to put it in there +that's my attention + + align:start position:0% +that's my attention + + + align:start position:0% +that's my attention +getter official name + + align:start position:0% +getter official name + + + align:start position:0% +getter official name +uh so I had I had the idea of a + + align:start position:0% +uh so I had I had the idea of a + + + align:start position:0% +uh so I had I had the idea of a +butterfly like in Victoria BC um I went + + align:start position:0% +butterfly like in Victoria BC um I went + + + align:start position:0% +butterfly like in Victoria BC um I went +into this I guess it was a zoo or it + + align:start position:0% +into this I guess it was a zoo or it + + + align:start position:0% +into this I guess it was a zoo or it +wasn't even a zoo was there was a few + + align:start position:0% +wasn't even a zoo was there was a few + + + align:start position:0% +wasn't even a zoo was there was a few +animals around but their main attraction + + align:start position:0% +animals around but their main attraction + + + align:start position:0% +animals around but their main attraction +was this huge butterfly uh conservatory + + align:start position:0% +was this huge butterfly uh conservatory + + + align:start position:0% +was this huge butterfly uh conservatory +and you just walk in there and you're + + align:start position:0% +and you just walk in there and you're + + + align:start position:0% +and you just walk in there and you're +surrounded by butterflies and you can + + align:start position:0% +surrounded by butterflies and you can + + + align:start position:0% +surrounded by butterflies and you can +touch them or whatever and uh it's just + + align:start position:0% +touch them or whatever and uh it's just + + + align:start position:0% +touch them or whatever and uh it's just +kind of no like you're just I don't know + + align:start position:0% +kind of no like you're just I don't know + + + align:start position:0% +kind of no like you're just I don't know +I had a great feeling about it I + + align:start position:0% +I had a great feeling about it I + + + align:start position:0% +I had a great feeling about it I +couldn't can't really describe the + + align:start position:0% +couldn't can't really describe the + + + align:start position:0% +couldn't can't really describe the +feeling but uh I want to go back there + + align:start position:0% +feeling but uh I want to go back there + + + align:start position:0% +feeling but uh I want to go back there +and I haven't I haven't gone back yet um + + align:start position:0% +and I haven't I haven't gone back yet um + + + align:start position:0% +and I haven't I haven't gone back yet um +but anyway I wanted to capture that uh I + + align:start position:0% +but anyway I wanted to capture that uh I + + + align:start position:0% +but anyway I wanted to capture that uh I +want to bring nature into the North End + + align:start position:0% +want to bring nature into the North End + + + align:start position:0% +want to bring nature into the North End +that was kind of the goal of the project + + align:start position:0% +that was kind of the goal of the project + + + align:start position:0% +that was kind of the goal of the project +and uh it + + align:start position:0% +and uh it + + + align:start position:0% +and uh it +was was interesting it was fun um but I + + align:start position:0% +was was interesting it was fun um but I + + + align:start position:0% +was was interesting it was fun um but I +did get a chance to go and during + + align:start position:0% +did get a chance to go and during + + + align:start position:0% +did get a chance to go and during +Thanksgiving I went down to New York and + + align:start position:0% +Thanksgiving I went down to New York and + + + align:start position:0% +Thanksgiving I went down to New York and +just by chance I went to see a friend's + + align:start position:0% +just by chance I went to see a friend's + + + align:start position:0% +just by chance I went to see a friend's +dad's exhibit in the museum of natural + + align:start position:0% +dad's exhibit in the museum of natural + + + align:start position:0% +dad's exhibit in the museum of natural +history and I saw this thing and it just + + align:start position:0% +history and I saw this thing and it just + + + align:start position:0% +history and I saw this thing and it just +said butterflies and I was like hey you + + align:start position:0% +said butterflies and I was like hey you + + + align:start position:0% +said butterflies and I was like hey you +know I'm doing a project on butterfly so + + align:start position:0% +know I'm doing a project on butterfly so + + + align:start position:0% +know I'm doing a project on butterfly so +might as well go check it out and uh it + + align:start position:0% +might as well go check it out and uh it + + + align:start position:0% +might as well go check it out and uh it +turned out to be exactly what I was + + align:start position:0% +turned out to be exactly what I was + + + align:start position:0% +turned out to be exactly what I was +doing it's like uh there's just some + + align:start position:0% +doing it's like uh there's just some + + + align:start position:0% +doing it's like uh there's just some +images from it + + align:start position:0% +images from it + + + align:start position:0% +images from it +um and it's exactly how I imagined it so + + align:start position:0% +um and it's exactly how I imagined it so + + + align:start position:0% +um and it's exactly how I imagined it so +it was kind of cool just to see it from + + align:start position:0% +it was kind of cool just to see it from + + + align:start position:0% +it was kind of cool just to see it from +this junk model we moved into kind of uh + + align:start position:0% +this junk model we moved into kind of uh + + + align:start position:0% +this junk model we moved into kind of uh +the block model um I tried to be a + + align:start position:0% +the block model um I tried to be a + + + align:start position:0% +the block model um I tried to be a +little more realistic and I I've I kind + + align:start position:0% +little more realistic and I I've I kind + + + align:start position:0% +little more realistic and I I've I kind +of messed up I don't know I didn't + + align:start position:0% +of messed up I don't know I didn't + + + align:start position:0% +of messed up I don't know I didn't +translate it right basically I was + + align:start position:0% +translate it right basically I was + + + align:start position:0% +translate it right basically I was +trying to trans I like that one a lot + + align:start position:0% +trying to trans I like that one a lot + + + align:start position:0% +trying to trans I like that one a lot +better than this one and I it took me a + + align:start position:0% +better than this one and I it took me a + + + align:start position:0% +better than this one and I it took me a +little while to figure it out it's just + + align:start position:0% +little while to figure it out it's just + + + align:start position:0% +little while to figure it out it's just +different uh sizes and relationships + + align:start position:0% +different uh sizes and relationships + + + align:start position:0% +different uh sizes and relationships +between the the objects um but like I + + align:start position:0% +between the the objects um but like I + + + align:start position:0% +between the the objects um but like I +really liked what was going on there and + + align:start position:0% +really liked what was going on there and + + + align:start position:0% +really liked what was going on there and +I wasn't able to translate it into real + + align:start position:0% +I wasn't able to translate it into real + + + align:start position:0% +I wasn't able to translate it into real +real form so I kind of struggled with + + align:start position:0% +real form so I kind of struggled with + + + align:start position:0% +real form so I kind of struggled with +that little bit model the yeah linear + + align:start position:0% +that little bit model the yeah linear + + + align:start position:0% +that little bit model the yeah linear +forms and the like um do you find + + align:start position:0% +forms and the like um do you find + + + align:start position:0% +forms and the like um do you find +yourself struggling to get back + + align:start position:0% +yourself struggling to get back + + + align:start position:0% +yourself struggling to get back +to oh yeah it's that that was my biggest + + align:start position:0% +to oh yeah it's that that was my biggest + + + align:start position:0% +to oh yeah it's that that was my biggest +struggle like I wanted to build that + + align:start position:0% +struggle like I wanted to build that + + + align:start position:0% +struggle like I wanted to build that +basically and + + align:start position:0% +basically and + + + align:start position:0% +basically and +um and is it the modules that you're + + align:start position:0% +um and is it the modules that you're + + + align:start position:0% +um and is it the modules that you're +you're given for for constructing that + + align:start position:0% +you're given for for constructing that + + + align:start position:0% +you're given for for constructing that +or just the difficulty of having tools + + align:start position:0% +or just the difficulty of having tools + + + align:start position:0% +or just the difficulty of having tools +yeah I + + align:start position:0% +yeah I + + + align:start position:0% +yeah I +think for some reason the pre-made form + + align:start position:0% +think for some reason the pre-made form + + + align:start position:0% +think for some reason the pre-made form +forms like were really easy to kind of + + align:start position:0% +forms like were really easy to kind of + + + align:start position:0% +forms like were really easy to kind of +you just kind + + align:start position:0% +you just kind + + + align:start position:0% +you just kind +of got what they stood for and put them + + align:start position:0% +of got what they stood for and put them + + + align:start position:0% +of got what they stood for and put them +in their appropriate place and here + + align:start position:0% +in their appropriate place and here + + + align:start position:0% +in their appropriate place and here +you're making everything and you can't + + align:start position:0% +you're making everything and you can't + + + align:start position:0% +you're making everything and you can't +really remake I don't know if I copied + + align:start position:0% +really remake I don't know if I copied + + + align:start position:0% +really remake I don't know if I copied +that exactly it wouldn't be the same so + + align:start position:0% +that exactly it wouldn't be the same so + + + align:start position:0% +that exactly it wouldn't be the same so +um it's a lot about the texture as well + + align:start position:0% +um it's a lot about the texture as well + + + align:start position:0% +um it's a lot about the texture as well +um I just really like that model and I + + align:start position:0% +um I just really like that model and I + + + align:start position:0% +um I just really like that model and I +was having struggling to uh put it into + + align:start position:0% +was having struggling to uh put it into + + + align:start position:0% +was having struggling to uh put it into +form uh then we moved up to a eight + + align:start position:0% +form uh then we moved up to a eight + + + align:start position:0% +form uh then we moved up to a eight +scale model I it's still up in studio um + + align:start position:0% +scale model I it's still up in studio um + + + align:start position:0% +scale model I it's still up in studio um +in the hectic rush I forgot it um this + + align:start position:0% +in the hectic rush I forgot it um this + + + align:start position:0% +in the hectic rush I forgot it um this +is the newer eight scale model but that + + align:start position:0% +is the newer eight scale model but that + + + align:start position:0% +is the newer eight scale model but that +was my old eight scale model and then + + align:start position:0% +was my old eight scale model and then + + + align:start position:0% +was my old eight scale model and then +what we do is we cut a section of it um + + align:start position:0% +what we do is we cut a section of it um + + + align:start position:0% +what we do is we cut a section of it um +well it was similar to this and we cut a + + align:start position:0% +well it was similar to this and we cut a + + + align:start position:0% +well it was similar to this and we cut a +section cut out of it and just take that + + align:start position:0% +section cut out of it and just take that + + + align:start position:0% +section cut out of it and just take that +chunk I I cut right here and so this was + + align:start position:0% +chunk I I cut right here and so this was + + + align:start position:0% +chunk I I cut right here and so this was +any blew it up to quarter scale and + + align:start position:0% +any blew it up to quarter scale and + + + align:start position:0% +any blew it up to quarter scale and +uh I just kind of had fun with it so + + align:start position:0% +uh I just kind of had fun with it so + + + align:start position:0% +uh I just kind of had fun with it so +from that we went on to drawing like we + + align:start position:0% +from that we went on to drawing like we + + + align:start position:0% +from that we went on to drawing like we +just went straight to drawing sections + + align:start position:0% +just went straight to drawing sections + + + align:start position:0% +just went straight to drawing sections +and plans and uh and then finally the + + align:start position:0% +and plans and uh and then finally the + + + align:start position:0% +and plans and uh and then finally the +Big H scale model um I guess I'll talk a + + align:start position:0% +Big H scale model um I guess I'll talk a + + + align:start position:0% +Big H scale model um I guess I'll talk a +little bit about + + align:start position:0% +little bit about + + + align:start position:0% +little bit about +what what's going on here uh people are + + align:start position:0% +what what's going on here uh people are + + + align:start position:0% +what what's going on here uh people are +going to be entering from um the t- stop + + align:start position:0% +going to be entering from um the t- stop + + + align:start position:0% +going to be entering from um the t- stop +and I kind of wanted to bring them in + + align:start position:0% +and I kind of wanted to bring them in + + + align:start position:0% +and I kind of wanted to bring them in +with a with a curve I don't know + + align:start position:0% +with a with a curve I don't know + + + align:start position:0% +with a with a curve I don't know +uh I want to bring them into my space + + align:start position:0% +uh I want to bring them into my space + + + align:start position:0% +uh I want to bring them into my space +and so they they come in and they see + + align:start position:0% +and so they they come in and they see + + + align:start position:0% +and so they they come in and they see +immediately the + + align:start position:0% +immediately the + + + align:start position:0% +immediately the +butterfly uh conservatory and that + + align:start position:0% +butterfly uh conservatory and that + + + align:start position:0% +butterfly uh conservatory and that +interests them and the ramp is kind of + + align:start position:0% +interests them and the ramp is kind of + + + align:start position:0% +interests them and the ramp is kind of +their way like it kind of signals that + + align:start position:0% +their way like it kind of signals that + + + align:start position:0% +their way like it kind of signals that +that's the way to get to the + + align:start position:0% +that's the way to get to the + + + align:start position:0% +that's the way to get to the +Conservatory so they come up through + + align:start position:0% +Conservatory so they come up through + + + align:start position:0% +Conservatory so they come up through +there's a library that um on the second + + align:start position:0% +there's a library that um on the second + + + align:start position:0% +there's a library that um on the second +and third floor it's kind of a smaller + + align:start position:0% +and third floor it's kind of a smaller + + + align:start position:0% +and third floor it's kind of a smaller +Library more focused on nature there's + + align:start position:0% +Library more focused on nature there's + + + align:start position:0% +Library more focused on nature there's +already one library in the North End so + + align:start position:0% +already one library in the North End so + + + align:start position:0% +already one library in the North End so +this one was just more I don't know + + align:start position:0% +this one was just more I don't know + + + align:start position:0% +this one was just more I don't know +animals like if kids come and they want + + align:start position:0% +animals like if kids come and they want + + + align:start position:0% +animals like if kids come and they want +to learn more about the butterflies + + align:start position:0% +to learn more about the butterflies + + + align:start position:0% +to learn more about the butterflies +where they come from and you know + + align:start position:0% +where they come from and you know + + + align:start position:0% +where they come from and you know +um then this is a place just a kind of + + align:start position:0% +um then this is a place just a kind of + + + align:start position:0% +um then this is a place just a kind of +it's not a checkout Library it's just + + align:start position:0% +it's not a checkout Library it's just + + + align:start position:0% +it's not a checkout Library it's just +you sit read out on there's a deck here + + align:start position:0% +you sit read out on there's a deck here + + + align:start position:0% +you sit read out on there's a deck here +where you can sit and look up + + align:start position:0% + + + + align:start position:0% + +through + + align:start position:0% + + + + align:start position:0% + +which I see stairs coming up they be + + align:start position:0% + + + + align:start position:0% + +passing yeah um the second level is the + + align:start position:0% +passing yeah um the second level is the + + + align:start position:0% +passing yeah um the second level is the +ele this is just a direct kind of a path + + align:start position:0% +ele this is just a direct kind of a path + + + align:start position:0% +ele this is just a direct kind of a path +to the Butterfly Conservatory so that's + + align:start position:0% +to the Butterfly Conservatory so that's + + + align:start position:0% +to the Butterfly Conservatory so that's +what people are going to see and then if + + align:start position:0% +what people are going to see and then if + + + align:start position:0% +what people are going to see and then if +if they've been here before and they + + align:start position:0% +if they've been here before and they + + + align:start position:0% +if they've been here before and they +actually want to go visit the library or + + align:start position:0% +actually want to go visit the library or + + + align:start position:0% +actually want to go visit the library or +they're done visiting then they can take + + align:start position:0% +they're done visiting then they can take + + + align:start position:0% +they're done visiting then they can take +the elevator down to the second floor or + + align:start position:0% +the elevator down to the second floor or + + + align:start position:0% +the elevator down to the second floor or +the first floor and then also there's + + align:start position:0% +the first floor and then also there's + + + align:start position:0% +the first floor and then also there's +kind of an IMAX style theater um in the + + align:start position:0% +kind of an IMAX style theater um in the + + + align:start position:0% +kind of an IMAX style theater um in the +corner the sun South is this direction + + align:start position:0% +corner the sun South is this direction + + + align:start position:0% +corner the sun South is this direction +and this is a very difficult site + + align:start position:0% +and this is a very difficult site + + + align:start position:0% +and this is a very difficult site +because there's almost no natural + + align:start position:0% +because there's almost no natural + + + align:start position:0% +because there's almost no natural +sunlight everything's blocked and I this + + align:start position:0% +sunlight everything's blocked and I this + + + align:start position:0% +sunlight everything's blocked and I this +the perfect spot for a theater which is + + align:start position:0% +the perfect spot for a theater which is + + + align:start position:0% +the perfect spot for a theater which is +dark and you want it to be dark you + + align:start position:0% +dark and you want it to be dark you + + + align:start position:0% +dark and you want it to be dark you +don't want you you don't want sun + + align:start position:0% +don't want you you don't want sun + + + align:start position:0% +don't want you you don't want sun +shining in necessarily + + align:start position:0% +shining in necessarily + + + align:start position:0% +shining in necessarily +um so this end up being a perfect spot + + align:start position:0% +um so this end up being a perfect spot + + + align:start position:0% +um so this end up being a perfect spot +for a theater whereas the library was + + align:start position:0% +for a theater whereas the library was + + + align:start position:0% +for a theater whereas the library was +more open and um + + align:start position:0% +more open and um + + + align:start position:0% +more open and um +sunny and how do you get to this um the + + align:start position:0% +sunny and how do you get to this um the + + + align:start position:0% +sunny and how do you get to this um the +garden what's the relationship of the + + align:start position:0% +garden what's the relationship of the + + + align:start position:0% +garden what's the relationship of the +garden to the path the garden is for + + align:start position:0% +garden to the path the garden is for + + + align:start position:0% +garden to the path the garden is for +people who have already gone up and + + align:start position:0% +people who have already gone up and + + + align:start position:0% +people who have already gone up and +there's going to be a lot of tourists + + align:start position:0% +there's going to be a lot of tourists + + + align:start position:0% +there's going to be a lot of tourists +you know coming just to see the + + align:start position:0% +you know coming just to see the + + + align:start position:0% +you know coming just to see the +butterflies and they're going to come do + + align:start position:0% +butterflies and they're going to come do + + + align:start position:0% +butterflies and they're going to come do +their thing and then leave but uh the + + align:start position:0% +their thing and then leave but uh the + + + align:start position:0% +their thing and then leave but uh the +garden is more for the locals to come + + align:start position:0% +garden is more for the locals to come + + + align:start position:0% +garden is more for the locals to come +and still enjoy the butterflies without + + align:start position:0% +and still enjoy the butterflies without + + + align:start position:0% +and still enjoy the butterflies without +like they can come in and see up through + + align:start position:0% +like they can come in and see up through + + + align:start position:0% +like they can come in and see up through +and they can relax read books whatever + + align:start position:0% +and they can relax read books whatever + + + align:start position:0% +and they can relax read books whatever +in the um so you you double back the way + + align:start position:0% +in the um so you you double back the way + + + align:start position:0% +in the um so you you double back the way +you came in you go out that + + align:start position:0% +you came in you go out that + + + align:start position:0% +you came in you go out that +way so it's not it's not a sort of a a + + align:start position:0% +way so it's not it's not a sort of a a + + + align:start position:0% +way so it's not it's not a sort of a a +cycle that you go because you sort of + + align:start position:0% +cycle that you go because you sort of + + + align:start position:0% +cycle that you go because you sort of +indicate it's a kind of a journey yeah + + align:start position:0% +indicate it's a kind of a journey yeah + + + align:start position:0% +indicate it's a kind of a journey yeah +that goes up and you go through it but + + align:start position:0% +that goes up and you go through it but + + + align:start position:0% +that goes up and you go through it but +then you double back on that journey and + + align:start position:0% +then you double back on that journey and + + + align:start position:0% +then you double back on that journey and +go down again is that right + + align:start position:0% +go down again is that right + + + align:start position:0% +go down again is that right +yeah you didn't want a journey to + + align:start position:0% +yeah you didn't want a journey to + + + align:start position:0% +yeah you didn't want a journey to +continue and go down into the garden and + + align:start position:0% +continue and go down into the garden and + + + align:start position:0% +continue and go down into the garden and +just I'm just curious as to why you make + + align:start position:0% +just I'm just curious as to why you make + + + align:start position:0% +just I'm just curious as to why you make +people come back you know what I + + align:start position:0% +people come back you know what I + + + align:start position:0% +people come back you know what I +honestly did not I never took it through + + align:start position:0% +honestly did not I never took it through + + + align:start position:0% +honestly did not I never took it through +to that + + align:start position:0% +to that + + + align:start position:0% +to that +point what was your what was the piece + + align:start position:0% +point what was your what was the piece + + + align:start position:0% +point what was your what was the piece +that you focused on the most in this + + align:start position:0% +that you focused on the most in this + + + align:start position:0% +that you focused on the most in this +design what was key issues for you well + + align:start position:0% +design what was key issues for you well + + + align:start position:0% +design what was key issues for you well +obviously it was the the actual + + align:start position:0% +obviously it was the the actual + + + align:start position:0% +obviously it was the the actual +structure of that um + + align:start position:0% +structure of that um + + + align:start position:0% +structure of that um +that that was like my main focus cuz + + align:start position:0% +that that was like my main focus cuz + + + align:start position:0% +that that was like my main focus cuz +when when I blowed it blew it up to + + align:start position:0% +when when I blowed it blew it up to + + + align:start position:0% +when when I blowed it blew it up to +quarter scale it was just made it that + + align:start position:0% +quarter scale it was just made it that + + + align:start position:0% +quarter scale it was just made it that +much more + + align:start position:0% +much more + + + align:start position:0% +much more +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +um and I also focused on the theater the + + align:start position:0% +um and I also focused on the theater the + + + align:start position:0% +um and I also focused on the theater the +library was kind + + align:start position:0% +library was kind + + + align:start position:0% +library was kind +of it wasn't a primary focus + + align:start position:0% + + + + align:start position:0% + +but just what do you see inside besides + + align:start position:0% +but just what do you see inside besides + + + align:start position:0% +but just what do you see inside besides +butterflies presuming the plants in here + + align:start position:0% +butterflies presuming the plants in here + + + align:start position:0% +butterflies presuming the plants in here +yes plants and yeah places to sit is + + align:start position:0% +yes plants and yeah places to sit is + + + align:start position:0% +yes plants and yeah places to sit is +there anything like that or just or you + + align:start position:0% +there anything like that or just or you + + + align:start position:0% +there anything like that or just or you +walk around it's just kind of it's a + + align:start position:0% +walk around it's just kind of it's a + + + align:start position:0% +walk around it's just kind of it's a +walk it's not a sitting a sitting is + + align:start position:0% +walk it's not a sitting a sitting is + + + align:start position:0% +walk it's not a sitting a sitting is +more for the under underneath + + align:start position:0% +more for the under underneath + + + align:start position:0% +more for the under underneath +underneath um I I kind of imagine it + + align:start position:0% +underneath um I I kind of imagine it + + + align:start position:0% +underneath um I I kind of imagine it +even well before I visit here this is + + align:start position:0% +even well before I visit here this is + + + align:start position:0% +even well before I visit here this is +kind of a this is a lot smaller than uh + + align:start position:0% +kind of a this is a lot smaller than uh + + + align:start position:0% +kind of a this is a lot smaller than uh +what I would build but it was you just + + align:start position:0% +what I would build but it was you just + + + align:start position:0% +what I would build but it was you just +kind of go through and circle through + + align:start position:0% +kind of go through and circle through + + + align:start position:0% +kind of go through and circle through +because they're sort of a habitat for + + align:start position:0% +because they're sort of a habitat for + + + align:start position:0% +because they're sort of a habitat for +butterflies right yeah so they have to + + align:start position:0% +butterflies right yeah so they have to + + + align:start position:0% +butterflies right yeah so they have to +have their place to land the light yeah + + align:start position:0% +have their place to land the light yeah + + + align:start position:0% +have their place to land the light yeah +I kind of I try to represent in a + + align:start position:0% +I kind of I try to represent in a + + + align:start position:0% +I kind of I try to represent in a +section I I I didn't know how to really + + align:start position:0% +section I I I didn't know how to really + + + align:start position:0% +section I I I didn't know how to really +I didn't want to put a lot of greenery + + align:start position:0% +I didn't want to put a lot of greenery + + + align:start position:0% +I didn't want to put a lot of greenery +you know and I don't + + align:start position:0% +you know and I don't + + + align:start position:0% +you know and I don't +like so the green the the glass floor + + align:start position:0% +like so the green the the glass floor + + + align:start position:0% +like so the green the the glass floor +then could you talk about that uh mainly + + align:start position:0% +then could you talk about that uh mainly + + + align:start position:0% +then could you talk about that uh mainly +that was for the experience of the + + align:start position:0% +that was for the experience of the + + + align:start position:0% +that was for the experience of the +garden underneath um for people to just + + align:start position:0% +garden underneath um for people to just + + + align:start position:0% +garden underneath um for people to just +kind of look up and have a cloud of + + align:start position:0% +kind of look up and have a cloud of + + + align:start position:0% +kind of look up and have a cloud of +butterflies above them and just okay be + + align:start position:0% +butterflies above them and just okay be + + + align:start position:0% +butterflies above them and just okay be +able to appreciate now to what degree + + align:start position:0% +able to appreciate now to what degree + + + align:start position:0% +able to appreciate now to what degree +did you you have program in mind when + + align:start position:0% +did you you have program in mind when + + + align:start position:0% +did you you have program in mind when +you developed the junk what object we we + + align:start position:0% +you developed the junk what object we we + + + align:start position:0% +you developed the junk what object we we +had a basic program of what kind of + + align:start position:0% +had a basic program of what kind of + + + align:start position:0% +had a basic program of what kind of +things we wanted in in the space and + + align:start position:0% +things we wanted in in the space and + + + align:start position:0% +things we wanted in in the space and +then we were told to forget that and + + align:start position:0% +then we were told to forget that and + + + align:start position:0% +then we were told to forget that and +play with objects as you were as you + + align:start position:0% +play with objects as you were as you + + + align:start position:0% +play with objects as you were as you +were developing that did you have + + align:start position:0% +were developing that did you have + + + align:start position:0% +were developing that did you have +specific program in mind for each of the + + align:start position:0% +specific program in mind for each of the + + + align:start position:0% +specific program in mind for each of the +components no I the only thing I had + + align:start position:0% +components no I the only thing I had + + + align:start position:0% +components no I the only thing I had +this plane here and then when I put that + + align:start position:0% +this plane here and then when I put that + + + align:start position:0% +this plane here and then when I put that +over I was talking about uh well I was + + align:start position:0% +over I was talking about uh well I was + + + align:start position:0% +over I was talking about uh well I was +either going to do a brewery or a + + align:start position:0% +either going to do a brewery or a + + + align:start position:0% +either going to do a brewery or a +butterfly um those are my two main ideas + + align:start position:0% +butterfly um those are my two main ideas + + + align:start position:0% +butterfly um those are my two main ideas +and + + align:start position:0% +and + + + align:start position:0% +and +uh and then when once I put this plane + + align:start position:0% +uh and then when once I put this plane + + + align:start position:0% +uh and then when once I put this plane +here and I found this uh refract refract + + align:start position:0% +here and I found this uh refract refract + + + align:start position:0% +here and I found this uh refract refract +paper refractor what's it called ref + + align:start position:0% +paper refractor what's it called ref + + + align:start position:0% +paper refractor what's it called ref +refractive paper + + align:start position:0% +refractive paper + + + align:start position:0% +refractive paper +um I just kind of drooped it over there + + align:start position:0% +um I just kind of drooped it over there + + + align:start position:0% +um I just kind of drooped it over there +and I was like oh this perfect and so + + align:start position:0% +and I was like oh this perfect and so + + + align:start position:0% +and I was like oh this perfect and so +then then + + align:start position:0% +then then + + + align:start position:0% +then then +I decided on the butterflies and just + + align:start position:0% +I decided on the butterflies and just + + + align:start position:0% +I decided on the butterflies and just +how how it work in the + + align:start position:0% +how how it work in the + + + align:start position:0% +how how it work in the +space what's what I find interesting is + + align:start position:0% +space what's what I find interesting is + + + align:start position:0% +space what's what I find interesting is +about this design process because it's a + + align:start position:0% +about this design process because it's a + + + align:start position:0% +about this design process because it's a +it is a unique design process in that + + align:start position:0% +it is a unique design process in that + + + align:start position:0% +it is a unique design process in that +you it starts with a + + align:start position:0% +you it starts with a + + + align:start position:0% +you it starts with a +compositional u process where you've got + + align:start position:0% +compositional u process where you've got + + + align:start position:0% +compositional u process where you've got +pieces and you move them around together + + align:start position:0% +pieces and you move them around together + + + align:start position:0% +pieces and you move them around together +in relation to a a context of form and + + align:start position:0% +in relation to a a context of form and + + + align:start position:0% +in relation to a a context of form and +you come up with an intriguing formal + + align:start position:0% +you come up with an intriguing formal + + + align:start position:0% +you come up with an intriguing formal +composition in and of itself yeah right + + align:start position:0% +composition in and of itself yeah right + + + align:start position:0% +composition in and of itself yeah right +fascinating fun and extremely exciting + + align:start position:0% +fascinating fun and extremely exciting + + + align:start position:0% +fascinating fun and extremely exciting +can generate very and frees you of the + + align:start position:0% +can generate very and frees you of the + + + align:start position:0% +can generate very and frees you of the +constraints of all these yeah it was + + align:start position:0% +constraints of all these yeah it was + + + align:start position:0% +constraints of all these yeah it was +then the issue is to transfer translate + + align:start position:0% +then the issue is to transfer translate + + + align:start position:0% +then the issue is to transfer translate +that into quote a habitable and + + align:start position:0% +that into quote a habitable and + + + align:start position:0% +that into quote a habitable and +functioning + + align:start position:0% +functioning + + + align:start position:0% +functioning +place um and uh the challenge there is + + align:start position:0% +place um and uh the challenge there is + + + align:start position:0% +place um and uh the challenge there is +to analy the + + align:start position:0% +to analy the + + + align:start position:0% +to analy the +model kinds of territories that have + + align:start position:0% +model kinds of territories that have + + + align:start position:0% +model kinds of territories that have +been made here uh to Define what kind of + + align:start position:0% +been made here uh to Define what kind of + + + align:start position:0% +been made here uh to Define what kind of +activities habitation each of those + + align:start position:0% +activities habitation each of those + + + align:start position:0% +activities habitation each of those +territories most suggest assume that's + + align:start position:0% +territories most suggest assume that's + + + align:start position:0% +territories most suggest assume that's +that that was kind of + + align:start position:0% + + + + align:start position:0% + +yeah the um um a couple + + align:start position:0% +yeah the um um a couple + + + align:start position:0% +yeah the um um a couple +of couple of things that sort of + + align:start position:0% +of couple of things that sort of + + + align:start position:0% +of couple of things that sort of +strike + + align:start position:0% + + + + align:start position:0% + +yeah keep going pieces that strike me um + + align:start position:0% +yeah keep going pieces that strike me um + + + align:start position:0% +yeah keep going pieces that strike me um +one you're starting now to uh add a + + align:start position:0% +one you're starting now to uh add a + + + align:start position:0% +one you're starting now to uh add a +recession okay uh to you you you're + + align:start position:0% +recession okay uh to you you you're + + + align:start position:0% +recession okay uh to you you you're +identify what I sense is an + + align:start position:0% +identify what I sense is an + + + align:start position:0% +identify what I sense is an +identification of main program elements + + align:start position:0% +identification of main program elements + + + align:start position:0% +identification of main program elements +you know the conservatory up high + + align:start position:0% +you know the conservatory up high + + + align:start position:0% +you know the conservatory up high +seeking the Sun the theater you describe + + align:start position:0% +seeking the Sun the theater you describe + + + align:start position:0% +seeking the Sun the theater you describe +being brought around and OCC place least + + align:start position:0% +being brought around and OCC place least + + + align:start position:0% +being brought around and OCC place least +like the library being put + + align:start position:0% +like the library being put + + + align:start position:0% +like the library being put +off um all I think in the park SL under + + align:start position:0% +off um all I think in the park SL under + + + align:start position:0% +off um all I think in the park SL under +all of which I think are quite + + align:start position:0% +all of which I think are quite + + + align:start position:0% +all of which I think are quite +fascinating locations I don't think I + + align:start position:0% +fascinating locations I don't think I + + + align:start position:0% +fascinating locations I don't think I +have a difficult time the disposition + + align:start position:0% +have a difficult time the disposition + + + align:start position:0% +have a difficult time the disposition +for the only piece I think is the + + align:start position:0% +for the only piece I think is the + + + align:start position:0% +for the only piece I think is the +trickiest is the is the space underneath + + align:start position:0% +trickiest is the is the space underneath + + + align:start position:0% +trickiest is the is the space underneath +the conservatory okay um in this + + align:start position:0% +the conservatory okay um in this + + + align:start position:0% +the conservatory okay um in this +particular climate I think that's a as a + + align:start position:0% +particular climate I think that's a as a + + + align:start position:0% +particular climate I think that's a as a +yearr round uh teritory it's a very + + align:start position:0% +yearr round uh teritory it's a very + + + align:start position:0% +yearr round uh teritory it's a very +difficult yeah kind of space but um I + + align:start position:0% +difficult yeah kind of space but um I + + + align:start position:0% +difficult yeah kind of space but um I +think in terms of + + align:start position:0% +think in terms of + + + align:start position:0% +think in terms of +function when one gets to when one comes + + align:start position:0% +function when one gets to when one comes + + + align:start position:0% +function when one gets to when one comes +to this point one should question you + + align:start position:0% +to this point one should question you + + + align:start position:0% +to this point one should question you +know now what does climate and Sun Etc + + align:start position:0% +know now what does climate and Sun Etc + + + align:start position:0% +know now what does climate and Sun Etc +have to do with habitation and I think + + align:start position:0% +have to do with habitation and I think + + + align:start position:0% +have to do with habitation and I think +then you have to start to let let + + align:start position:0% +then you have to start to let let + + + align:start position:0% +then you have to start to let let +yourself make + + align:start position:0% +yourself make + + + align:start position:0% +yourself make +modifications to address those kinds of + + align:start position:0% +modifications to address those kinds of + + + align:start position:0% +modifications to address those kinds of +issues um and it may have been about + + align:start position:0% +issues um and it may have been about + + + align:start position:0% +issues um and it may have been about +trying to grab some of that exterior + + align:start position:0% +trying to grab some of that exterior + + + align:start position:0% +trying to grab some of that exterior +space be semi interior exterior you know + + align:start position:0% +space be semi interior exterior you know + + + align:start position:0% +space be semi interior exterior you know +you close it up and and make it warm in + + align:start position:0% +you close it up and and make it warm in + + + align:start position:0% +you close it up and and make it warm in +the winter + + align:start position:0% +the winter + + + align:start position:0% +the winter +and but the one piece that I find is + + align:start position:0% +and but the one piece that I find is + + + align:start position:0% +and but the one piece that I find is +this movement pattern that's the most + + align:start position:0% +this movement pattern that's the most + + + align:start position:0% +this movement pattern that's the most +difficult I think it would uh one is + + align:start position:0% +difficult I think it would uh one is + + + align:start position:0% +difficult I think it would uh one is +getting to the + + align:start position:0% +getting to the + + + align:start position:0% +getting to the +cons one is getting to the conservatory + + align:start position:0% +cons one is getting to the conservatory + + + align:start position:0% +cons one is getting to the conservatory +and having to pass through places that + + align:start position:0% +and having to pass through places that + + + align:start position:0% +and having to pass through places that +in fact probably don't desire the sort + + align:start position:0% +in fact probably don't desire the sort + + + align:start position:0% +in fact probably don't desire the sort +of main Rush of public activity right + + align:start position:0% +of main Rush of public activity right + + + align:start position:0% +of main Rush of public activity right +now what's happened is in making a + + align:start position:0% +now what's happened is in making a + + + align:start position:0% +now what's happened is in making a +public place you've made every space + + align:start position:0% +public place you've made every space + + + align:start position:0% +public place you've made every space +somewhat equally public by allowing the + + align:start position:0% +somewhat equally public by allowing the + + + align:start position:0% +somewhat equally public by allowing the +circulation to flow through + + align:start position:0% +circulation to flow through + + + align:start position:0% +circulation to flow through +it so I think the hardest piece for me + + align:start position:0% +it so I think the hardest piece for me + + + align:start position:0% +it so I think the hardest piece for me +is the ramp finally coming and one + + align:start position:0% +is the ramp finally coming and one + + + align:start position:0% +is the ramp finally coming and one +bypassing the the library and the main + + align:start position:0% +bypassing the the library and the main + + + align:start position:0% +bypassing the the library and the main +desk to the library scooting them up + + align:start position:0% +desk to the library scooting them up + + + align:start position:0% +desk to the library scooting them up +above it and run and asking people to + + align:start position:0% +above it and run and asking people to + + + align:start position:0% +above it and run and asking people to +walk through the library and finally + + align:start position:0% +walk through the library and finally + + + align:start position:0% +walk through the library and finally +find the conservatory because in many + + align:start position:0% +find the conservatory because in many + + + align:start position:0% +find the conservatory because in many +ways we're doing two things we're + + align:start position:0% +ways we're doing two things we're + + + align:start position:0% +ways we're doing two things we're +violating the library then the library + + align:start position:0% +violating the library then the library + + + align:start position:0% +violating the library then the library +function and the ability to go off and + + align:start position:0% +function and the ability to go off and + + + align:start position:0% +function and the ability to go off and +concentrate there and two we're asking + + align:start position:0% +concentrate there and two we're asking + + + align:start position:0% +concentrate there and two we're asking +people to wander through wander very far + + align:start position:0% +people to wander through wander very far + + + align:start position:0% +people to wander through wander very far +away from the conservatory even though + + align:start position:0% +away from the conservatory even though + + + align:start position:0% +away from the conservatory even though +that may be their destination we're + + align:start position:0% +that may be their destination we're + + + align:start position:0% +that may be their destination we're +asking to go somewhere else and get lost + + align:start position:0% +asking to go somewhere else and get lost + + + align:start position:0% +asking to go somewhere else and get lost +in the building and then finally come + + align:start position:0% +in the building and then finally come + + + align:start position:0% +in the building and then finally come +around to + + align:start position:0% +around to + + + align:start position:0% +around to +it + + align:start position:0% +it + + + align:start position:0% +it +actually well my basic reasoning for + + align:start position:0% +actually well my basic reasoning for + + + align:start position:0% +actually well my basic reasoning for +bringing it around um I kind of want to + + align:start position:0% +bringing it around um I kind of want to + + + align:start position:0% +bringing it around um I kind of want to +give a taste of what else was there + + align:start position:0% +give a taste of what else was there + + + align:start position:0% +give a taste of what else was there +because uh when you have something like + + align:start position:0% +because uh when you have something like + + + align:start position:0% +because uh when you have something like +this uh the tendency is just to come see + + align:start position:0% +this uh the tendency is just to come see + + + align:start position:0% +this uh the tendency is just to come see +that and you're done like it's uh direct + + align:start position:0% +that and you're done like it's uh direct + + + align:start position:0% +that and you're done like it's uh direct +movement and I kind of wanted to bring + + align:start position:0% +movement and I kind of wanted to bring + + + align:start position:0% +movement and I kind of wanted to bring +people through the space give them an + + align:start position:0% +people through the space give them an + + + align:start position:0% +people through the space give them an +idea of just what else goes on there um + + align:start position:0% +idea of just what else goes on there um + + + align:start position:0% +idea of just what else goes on there um +It's a Wonderful notion I think that + + align:start position:0% +It's a Wonderful notion I think that + + + align:start position:0% +It's a Wonderful notion I think that +that idea is a solid one I think the + + align:start position:0% +that idea is a solid one I think the + + + align:start position:0% +that idea is a solid one I think the +execution of + + align:start position:0% +execution of + + + align:start position:0% +execution of +it hurts the actual spaces that you're + + align:start position:0% +it hurts the actual spaces that you're + + + align:start position:0% +it hurts the actual spaces that you're +trying to introduce okay um one is I + + align:start position:0% +trying to introduce okay um one is I + + + align:start position:0% +trying to introduce okay um one is I +think it would be lovely to in this in + + align:start position:0% +think it would be lovely to in this in + + + align:start position:0% +think it would be lovely to in this in +this procession up through ramps and + + align:start position:0% +this procession up through ramps and + + + align:start position:0% +this procession up through ramps and +stairs to be able to reach a place where + + align:start position:0% +stairs to be able to reach a place where + + + align:start position:0% +stairs to be able to reach a place where +one could depart that ramp and go to a + + align:start position:0% +one could depart that ramp and go to a + + + align:start position:0% +one could depart that ramp and go to a +library you know or from that ramp see + + align:start position:0% +library you know or from that ramp see + + + align:start position:0% +library you know or from that ramp see +the activities of the library move past + + align:start position:0% +the activities of the library move past + + + align:start position:0% +the activities of the library move past +it um or continue on up to find + + align:start position:0% +it um or continue on up to find + + + align:start position:0% +it um or continue on up to find +Conservatory one could get to the + + align:start position:0% +Conservatory one could get to the + + + align:start position:0% +Conservatory one could get to the +conservatory fairly easily + + align:start position:0% +conservatory fairly easily + + + align:start position:0% +conservatory fairly easily +um and could get to each of the + + align:start position:0% +um and could get to each of the + + + align:start position:0% +um and could get to each of the +levels with that main R I think this the + + align:start position:0% +levels with that main R I think this the + + + align:start position:0% +levels with that main R I think this the +ele using the elevator's device to bring + + align:start position:0% +ele using the elevator's device to bring + + + align:start position:0% +ele using the elevator's device to bring +public to each of the territories is + + align:start position:0% +public to each of the territories is + + + align:start position:0% +public to each of the territories is +probably an unfortunate okay Mo of + + align:start position:0% +probably an unfortunate okay Mo of + + + align:start position:0% +probably an unfortunate okay Mo of +trans + + align:start position:0% +trans + + + align:start position:0% +trans +vertical those those are the few things + + align:start position:0% +vertical those those are the few things + + + align:start position:0% +vertical those those are the few things +screen the third ke that'll be done is + + align:start position:0% +screen the third ke that'll be done is + + + align:start position:0% +screen the third ke that'll be done is +the theater and the notion of entrance + + align:start position:0% +the theater and the notion of entrance + + + align:start position:0% +the theater and the notion of entrance +to a theater um um many ways if one is + + align:start position:0% +to a theater um um many ways if one is + + + align:start position:0% +to a theater um um many ways if one is +if the stage becomes the place of focus + + align:start position:0% +if the stage becomes the place of focus + + + align:start position:0% +if the stage becomes the place of focus +the entire audience is watching um some + + align:start position:0% +the entire audience is watching um some + + + align:start position:0% +the entire audience is watching um some +activity that's been presented a very + + align:start position:0% +activity that's been presented a very + + + align:start position:0% +activity that's been presented a very +uncomfortable place for people to enter + + align:start position:0% +uncomfortable place for people to enter + + + align:start position:0% +uncomfortable place for people to enter +is onto that stage yeah I guess I was + + align:start position:0% +is onto that stage yeah I guess I was + + + align:start position:0% +is onto that stage yeah I guess I was +kind of well generally thinking of just + + align:start position:0% +kind of well generally thinking of just + + + align:start position:0% +kind of well generally thinking of just +how I don't know the one theater that I + + align:start position:0% +how I don't know the one theater that I + + + align:start position:0% +how I don't know the one theater that I +go to is a Fenway um and you come down + + align:start position:0% +go to is a Fenway um and you come down + + + align:start position:0% +go to is a Fenway um and you come down +the sides and enter in the front and + + align:start position:0% +the sides and enter in the front and + + + align:start position:0% +the sides and enter in the front and +that's just kind of what I was used to + + align:start position:0% +that's just kind of what I was used to + + + align:start position:0% +that's just kind of what I was used to +and the movie theater but uh this is + + align:start position:0% +and the movie theater but uh this is + + + align:start position:0% +and the movie theater but uh this is +this is this is the IMAX like uh it's + + align:start position:0% +this is this is the IMAX like uh it's + + + align:start position:0% +this is this is the IMAX like uh it's +going + + align:start position:0% +going + + + align:start position:0% +going +to what what what helps is to get people + + align:start position:0% +to what what what helps is to get people + + + align:start position:0% +to what what what helps is to get people +off up to the back what you do yeah + + align:start position:0% +off up to the back what you do yeah + + + align:start position:0% +off up to the back what you do yeah +there's also uh you can enter on the + + align:start position:0% +there's also uh you can enter on the + + + align:start position:0% +there's also uh you can enter on the +second floor that's but if that if that + + align:start position:0% +second floor that's but if that if that + + + align:start position:0% +second floor that's but if that if that +place coming into the second floor was + + align:start position:0% +place coming into the second floor was + + + align:start position:0% +place coming into the second floor was +part of your main lobby you go to that + + align:start position:0% +part of your main lobby you go to that + + + align:start position:0% +part of your main lobby you go to that +directly got viol so you can enter the + + align:start position:0% +directly got viol so you can enter the + + + align:start position:0% +directly got viol so you can enter the +space observe it get a sense of what's + + align:start position:0% +space observe it get a sense of what's + + + align:start position:0% +space observe it get a sense of what's +going on without disturbing the FOC + + align:start position:0% +going on without disturbing the FOC + + + align:start position:0% +going on without disturbing the FOC +so all of these issues have to do with + + align:start position:0% +so all of these issues have to do with + + + align:start position:0% +so all of these issues have to do with +the procession and way one through the + + align:start position:0% +the procession and way one through the + + + align:start position:0% +the procession and way one through the +transitions + + align:start position:0% +transitions + + + align:start position:0% +transitions +between I had the same I guess + + align:start position:0% +between I had the same I guess + + + align:start position:0% +between I had the same I guess +um my first or biggest reaction relates + + align:start position:0% +um my first or biggest reaction relates + + + align:start position:0% +um my first or biggest reaction relates +to the movement + + align:start position:0% +to the movement + + + align:start position:0% +to the movement +again and I had some of the same thing + + align:start position:0% +again and I had some of the same thing + + + align:start position:0% +again and I had some of the same thing +saying that it's so sort of frustrating + + align:start position:0% +saying that it's so sort of frustrating + + + align:start position:0% +saying that it's so sort of frustrating +to see this up there and not knowing + + align:start position:0% +to see this up there and not knowing + + + align:start position:0% +to see this up there and not knowing +quite what the journey is going to take + + align:start position:0% +quite what the journey is going to take + + + align:start position:0% +quite what the journey is going to take +you because in fact you're you want to + + align:start position:0% +you because in fact you're you want to + + + align:start position:0% +you because in fact you're you want to +get there but you're moving against it + + align:start position:0% +get there but you're moving against it + + + align:start position:0% +get there but you're moving against it +you know you're sort of going in the + + align:start position:0% +you know you're sort of going in the + + + align:start position:0% +you know you're sort of going in the +opposite direction so the feeling of of + + align:start position:0% +opposite direction so the feeling of of + + + align:start position:0% +opposite direction so the feeling of of +allowing you to somehow have a wonderful + + align:start position:0% +allowing you to somehow have a wonderful + + + align:start position:0% +allowing you to somehow have a wonderful +Journey that might eventually + + align:start position:0% +Journey that might eventually + + + align:start position:0% +Journey that might eventually +reveal this at different points and I + + align:start position:0% +reveal this at different points and I + + + align:start position:0% +reveal this at different points and I +the glass floor is also a point at which + + align:start position:0% +the glass floor is also a point at which + + + align:start position:0% +the glass floor is also a point at which +you could actually look up into + + align:start position:0% +you could actually look up into + + + align:start position:0% +you could actually look up into +something so maybe the journey could + + align:start position:0% +something so maybe the journey could + + + align:start position:0% +something so maybe the journey could +take you past the floor of this thing if + + align:start position:0% +take you past the floor of this thing if + + + align:start position:0% +take you past the floor of this thing if +you're going to look up 5 minut okay + + align:start position:0% +you're going to look up 5 minut okay + + + align:start position:0% +you're going to look up 5 minut okay +rather than just saying that's if you + + align:start position:0% +rather than just saying that's if you + + + align:start position:0% +rather than just saying that's if you +look down into it or you're going to + + align:start position:0% +look down into it or you're going to + + + align:start position:0% +look down into it or you're going to +look up to it make the Journey part of + + align:start position:0% +look up to it make the Journey part of + + + align:start position:0% +look up to it make the Journey part of +your make the experience part of it and + + align:start position:0% +your make the experience part of it and + + + align:start position:0% +your make the experience part of it and +then you arrived and I agree with um + + align:start position:0% +then you arrived and I agree with um + + + align:start position:0% +then you arrived and I agree with um +Alan that perhaps when you have those + + align:start position:0% +Alan that perhaps when you have those + + + align:start position:0% +Alan that perhaps when you have those +other spaces like a library which you + + align:start position:0% +other spaces like a library which you + + + align:start position:0% +other spaces like a library which you +want people to get to I could imagine + + align:start position:0% +want people to get to I could imagine + + + align:start position:0% +want people to get to I could imagine +the libraries being of actually sort of + + align:start position:0% +the libraries being of actually sort of + + + align:start position:0% +the libraries being of actually sort of +butterflies just samples and examples + + align:start position:0% +butterflies just samples and examples + + + align:start position:0% +butterflies just samples and examples +and a bit of history and all that sort + + align:start position:0% +and a bit of history and all that sort + + + align:start position:0% +and a bit of history and all that sort +of stuff the the + + align:start position:0% +of stuff the the + + + align:start position:0% +of stuff the the +labeling um that's something that you + + align:start position:0% +labeling um that's something that you + + + align:start position:0% +labeling um that's something that you +almost once you've seen these people + + align:start position:0% +almost once you've seen these people + + + align:start position:0% +almost once you've seen these people +it's you know you can have this choice + + align:start position:0% +it's you know you can have this choice + + + align:start position:0% +it's you know you can have this choice +about do you see them first and then you + + align:start position:0% +about do you see them first and then you + + + align:start position:0% +about do you see them first and then you +find out more about them because you're + + align:start position:0% +find out more about them because you're + + + align:start position:0% +find out more about them because you're +interested or do you find out something + + align:start position:0% +interested or do you find out something + + + align:start position:0% +interested or do you find out something +about them and then you see them now + + align:start position:0% +about them and then you see them now + + + align:start position:0% +about them and then you see them now +whether you give the people a choice or + + align:start position:0% +whether you give the people a choice or + + + align:start position:0% +whether you give the people a choice or +whether you take them through a journey + + align:start position:0% +whether you take them through a journey + + + align:start position:0% +whether you take them through a journey +I think it's something to worth worth + + align:start position:0% +I think it's something to worth worth + + + align:start position:0% +I think it's something to worth worth +thinking about and the relationship then + + align:start position:0% +thinking about and the relationship then + + + align:start position:0% +thinking about and the relationship then +of that library and those spaces to this + + align:start position:0% +of that library and those spaces to this + + + align:start position:0% +of that library and those spaces to this +open space in the middle and I totally + + align:start position:0% +open space in the middle and I totally + + + align:start position:0% +open space in the middle and I totally +agree you've got a very hard sight it's + + align:start position:0% +agree you've got a very hard sight it's + + + align:start position:0% +agree you've got a very hard sight it's +a dark North facing space so maybe I + + align:start position:0% +a dark North facing space so maybe I + + + align:start position:0% +a dark North facing space so maybe I +didn't know what you do in terms of + + align:start position:0% +didn't know what you do in terms of + + + align:start position:0% +didn't know what you do in terms of +trying to really bring life and people + + align:start position:0% +trying to really bring life and people + + + align:start position:0% +trying to really bring life and people +into that space because it's going to + + align:start position:0% +into that space because it's going to + + + align:start position:0% +into that space because it's going to +remain + + align:start position:0% +remain + + + align:start position:0% +remain +uninhabited quite a l of the time maybe + + align:start position:0% +uninhabited quite a l of the time maybe + + + align:start position:0% +uninhabited quite a l of the time maybe +a few months in the summer to get away + + align:start position:0% +a few months in the summer to get away + + + align:start position:0% +a few months in the summer to get away +from the heat it's the sort of nice cool + + align:start position:0% +from the heat it's the sort of nice cool + + + align:start position:0% +from the heat it's the sort of nice cool +place and in my mind and there's water + + align:start position:0% +place and in my mind and there's water + + + align:start position:0% +place and in my mind and there's water +yeah in my mind that's kind of the + + align:start position:0% +yeah in my mind that's kind of the + + + align:start position:0% +yeah in my mind that's kind of the +picture that I was imagining and yeah + + align:start position:0% +picture that I was imagining and yeah + + + align:start position:0% +picture that I was imagining and yeah +I the one that the forms are kind of + + align:start position:0% +I the one that the forms are kind of + + + align:start position:0% +I the one that the forms are kind of +interesting but the one that's I + + align:start position:0% +interesting but the one that's I + + + align:start position:0% +interesting but the one that's I +find I'm not quite sure what it's doing + + align:start position:0% +find I'm not quite sure what it's doing + + + align:start position:0% +find I'm not quite sure what it's doing +is that is that balcony thing sticking + + align:start position:0% +is that is that balcony thing sticking + + + align:start position:0% +is that is that balcony thing sticking +out and I find that kind of frustrating + + align:start position:0% +out and I find that kind of frustrating + + + align:start position:0% +out and I find that kind of frustrating +because it's in the space and it doesn't + + align:start position:0% +because it's in the space and it doesn't + + + align:start position:0% +because it's in the space and it doesn't +you know I don't know what you're feel + + align:start position:0% +you know I don't know what you're feel + + + align:start position:0% +you know I don't know what you're feel +about just the one that I would never + + align:start position:0% +about just the one that I would never + + + align:start position:0% +about just the one that I would never +before before the junk I would never + + align:start position:0% +before before the junk I would never + + + align:start position:0% +before before the junk I would never +have thought ever to put anything like + + align:start position:0% +have thought ever to put anything like + + + align:start position:0% +have thought ever to put anything like +that cuz it just kind of looks weird in + + align:start position:0% +that cuz it just kind of looks weird in + + + align:start position:0% +that cuz it just kind of looks weird in +a way you know in a way and uh no but I + + align:start position:0% +a way you know in a way and uh no but I + + + align:start position:0% +a way you know in a way and uh no but I +I built the junk model and I was + + align:start position:0% +I built the junk model and I was + + + align:start position:0% +I built the junk model and I was +completely just going on form and I + + align:start position:0% +completely just going on form and I + + + align:start position:0% +completely just going on form and I +tried I here the first translation I + + align:start position:0% +tried I here the first translation I + + + align:start position:0% +tried I here the first translation I +tried to get away from it um in a way uh + + align:start position:0% +tried to get away from it um in a way uh + + + align:start position:0% +tried to get away from it um in a way uh +did not didn't like it and for some + + align:start position:0% +did not didn't like it and for some + + + align:start position:0% +did not didn't like it and for some +reason I was just going to say all right + + align:start position:0% +reason I was just going to say all right + + + align:start position:0% +reason I was just going to say all right +I'm going to go with it and see what it + + align:start position:0% +I'm going to go with it and see what it + + + align:start position:0% +I'm going to go with it and see what it +does and so I I did I would usually + + align:start position:0% +does and so I I did I would usually + + + align:start position:0% +does and so I I did I would usually +never do that and so I just decided Well + + align:start position:0% +never do that and so I just decided Well + + + align:start position:0% +never do that and so I just decided Well +it's just I mean you can do it it's just + + align:start position:0% +it's just I mean you can do it it's just + + + align:start position:0% +it's just I mean you can do it it's just +I'm just curious about the space and how + + align:start position:0% +I'm just curious about the space and how + + + align:start position:0% +I'm just curious about the space and how +it would be and how it relates to the + + align:start position:0% +it would be and how it relates to the + + + align:start position:0% +it would be and how it relates to the +other spaces I first saw this entrance + + align:start position:0% +other spaces I first saw this entrance + + + align:start position:0% +other spaces I first saw this entrance +over here I thought oh wonderful this + + align:start position:0% +over here I thought oh wonderful this + + + align:start position:0% +over here I thought oh wonderful this +this building is really addressing you + + align:start position:0% +this building is really addressing you + + + align:start position:0% +this building is really addressing you +know people coming from many directions + + align:start position:0% +know people coming from many directions + + + align:start position:0% +know people coming from many directions +one thing that I'm finding about this it + + align:start position:0% +one thing that I'm finding about this it + + + align:start position:0% +one thing that I'm finding about this it +seems to be the the primary point of + + align:start position:0% +seems to be the the primary point of + + + align:start position:0% +seems to be the the primary point of +when you come into that space that's + + align:start position:0% +when you come into that space that's + + + align:start position:0% +when you come into that space that's +like Center and that's a place of choice + + align:start position:0% +like Center and that's a place of choice + + + align:start position:0% +like Center and that's a place of choice +when decides either from here to go to + + align:start position:0% +when decides either from here to go to + + + align:start position:0% +when decides either from here to go to +the theater or go off in the garden or + + align:start position:0% +the theater or go off in the garden or + + + align:start position:0% +the theater or go off in the garden or +start your procession up it would have + + align:start position:0% +start your procession up it would have + + + align:start position:0% +start your procession up it would have +been very nice if this path could have + + align:start position:0% +been very nice if this path could have + + + align:start position:0% +been very nice if this path could have +also brought us to a a common Point + + align:start position:0% +also brought us to a a common Point + + + align:start position:0% +also brought us to a a common Point +somewhere in the site so that everyone + + align:start position:0% +somewhere in the site so that everyone + + + align:start position:0% +somewhere in the site so that everyone +you know there was a coherent place of + + align:start position:0% +you know there was a coherent place of + + + align:start position:0% +you know there was a coherent place of +arrival which is what you seem to be + + align:start position:0% +arrival which is what you seem to be + + + align:start position:0% +arrival which is what you seem to be +seeking in that form I think if you + + align:start position:0% +seeking in that form I think if you + + + align:start position:0% +seeking in that form I think if you +could + + align:start position:0% +could + + + align:start position:0% +could +each of your + + align:start position:0% +each of your + + + align:start position:0% +each of your +forces that territory and yeah I can see + + align:start position:0% +forces that territory and yeah I can see + + + align:start position:0% +forces that territory and yeah I can see +that kind of flash like I wasn't + + align:start position:0% +that kind of flash like I wasn't + + + align:start position:0% +that kind of flash like I wasn't +yeah the last uh comment also relates to + + align:start position:0% +yeah the last uh comment also relates to + + + align:start position:0% +yeah the last uh comment also relates to +the theater yeah and for me anyway at + + align:start position:0% +the theater yeah and for me anyway at + + + align:start position:0% +the theater yeah and for me anyway at +the moment you said IMAX I think the + + align:start position:0% +the moment you said IMAX I think the + + + align:start position:0% +the moment you said IMAX I think the +scale of this is too small okay yeah + + align:start position:0% +scale of this is too small okay yeah + + + align:start position:0% +scale of this is too small okay yeah +it's a it's a small it's a much more + + align:start position:0% +it's a it's a small it's a much more + + + align:start position:0% +it's a it's a small it's a much more +intimate smaller space I don't know how + + align:start position:0% +intimate smaller space I don't know how + + + align:start position:0% +intimate smaller space I don't know how +many people are in this theater but it's + + align:start position:0% +many people are in this theater but it's + + + align:start position:0% +many people are in this theater but it's +not huge screen it's not so it's about + + align:start position:0% +not huge screen it's not so it's about + + + align:start position:0% +not huge screen it's not so it's about +something else it could be almost a + + align:start position:0% +something else it could be almost a + + + align:start position:0% +something else it could be almost a +lecture hall where people are told more + + align:start position:0% +lecture hall where people are told more + + + align:start position:0% +lecture hall where people are told more +about butterflies and shown things or it + + align:start position:0% +about butterflies and shown things or it + + + align:start position:0% +about butterflies and shown things or it +could be a movie about movies or smaller + + align:start position:0% +could be a movie about movies or smaller + + + align:start position:0% +could be a movie about movies or smaller +things and the shape of it is is nice + + align:start position:0% +things and the shape of it is is nice + + + align:start position:0% +things and the shape of it is is nice +and intriguing I understand why you've + + align:start position:0% +and intriguing I understand why you've + + + align:start position:0% +and intriguing I understand why you've +done that and bring people around a + + align:start position:0% +done that and bring people around a + + + align:start position:0% +done that and bring people around a +corner but when you're in that space + + align:start position:0% +corner but when you're in that space + + + align:start position:0% +corner but when you're in that space +think of how that movie screen actually + + align:start position:0% +think of how that movie screen actually + + + align:start position:0% +think of how that movie screen actually +plays out and where you sit and what you + + align:start position:0% +plays out and where you sit and what you + + + align:start position:0% +plays out and where you sit and what you +see and you're sort of you're feeling + + align:start position:0% +see and you're sort of you're feeling + + + align:start position:0% +see and you're sort of you're feeling +you're kind of slightly at an angle to + + align:start position:0% +you're kind of slightly at an angle to + + + align:start position:0% +you're kind of slightly at an angle to +everything you know all right so there's + + align:start position:0% +everything you know all right so there's + + + align:start position:0% +everything you know all right so there's +something about I think the design of + + align:start position:0% +something about I think the design of + + + align:start position:0% +something about I think the design of +theaters and the way that they open into + + align:start position:0% +theaters and the way that they open into + + + align:start position:0% +theaters and the way that they open into +the front whether it's a cinema or it's + + align:start position:0% +the front whether it's a cinema or it's + + + align:start position:0% +the front whether it's a cinema or it's +a um a movie I mean movie theater or an + + align:start position:0% +a um a movie I mean movie theater or an + + + align:start position:0% +a um a movie I mean movie theater or an +actual theater that I think just the + + align:start position:0% +actual theater that I think just the + + + align:start position:0% +actual theater that I think just the +location of the sculptural form versus + + align:start position:0% +location of the sculptural form versus + + + align:start position:0% +location of the sculptural form versus +the actual how you inhabit the + + align:start position:0% + + + + align:start position:0% + +space \ No newline at end of file diff --git a/-OeyjP2zri4.txt b/-OeyjP2zri4.txt new file mode 100644 index 0000000000000000000000000000000000000000..12f603434fed22362bf7bdc0113ddeaf4ac79586 --- /dev/null +++ b/-OeyjP2zri4.txt @@ -0,0 +1,14355 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +we started doing syntax + + align:start position:0% +we started doing syntax + + + align:start position:0% +we started doing syntax +and we had started drawing trees like + + align:start position:0% +and we had started drawing trees like + + + align:start position:0% +and we had started drawing trees like +this one + + align:start position:0% +this one + + + align:start position:0% +this one +um what I said I think was uh + + align:start position:0% +um what I said I think was uh + + + align:start position:0% +um what I said I think was uh +if you remember when we were looking + + align:start position:0% +if you remember when we were looking + + + align:start position:0% +if you remember when we were looking +when we were doing morphology and we + + align:start position:0% +when we were doing morphology and we + + + align:start position:0% +when we were doing morphology and we +were looking at words like unlockable we + + align:start position:0% +were looking at words like unlockable we + + + align:start position:0% +were looking at words like unlockable we +were convincing ourselves that it was + + align:start position:0% +were convincing ourselves that it was + + + align:start position:0% +were convincing ourselves that it was +profitable to think of words like that + + align:start position:0% +profitable to think of words like that + + + align:start position:0% +profitable to think of words like that +as not just consisting of three + + align:start position:0% +as not just consisting of three + + + align:start position:0% +as not just consisting of three +morphemes unlock + + align:start position:0% +morphemes unlock + + + align:start position:0% +morphemes unlock +and a bowl does consist of three + + align:start position:0% +and a bowl does consist of three + + + align:start position:0% +and a bowl does consist of three +morphemes but that it's useful to think + + align:start position:0% +morphemes but that it's useful to think + + + align:start position:0% +morphemes but that it's useful to think +of these three morphemes as being + + align:start position:0% +of these three morphemes as being + + + align:start position:0% +of these three morphemes as being +composed in pairs so there are sort of + + align:start position:0% +composed in pairs so there are sort of + + + align:start position:0% +composed in pairs so there are sort of +two ways to make the word unlockable you + + align:start position:0% +two ways to make the word unlockable you + + + align:start position:0% +two ways to make the word unlockable you +can put un together with lock and then + + align:start position:0% +can put un together with lock and then + + + align:start position:0% +can put un together with lock and then +you can pull the result of that together + + align:start position:0% +you can pull the result of that together + + + align:start position:0% +you can pull the result of that together +with bubble or you can put lock together + + align:start position:0% +with bubble or you can put lock together + + + align:start position:0% +with bubble or you can put lock together +with bubble and put the result of that + + align:start position:0% +with bubble and put the result of that + + + align:start position:0% +with bubble and put the result of that +together with on and that those those + + align:start position:0% +together with on and that those those + + + align:start position:0% +together with on and that those those +mean different things right that was + + align:start position:0% +mean different things right that was + + + align:start position:0% +mean different things right that was +that was what we were saying when we + + align:start position:0% +that was what we were saying when we + + + align:start position:0% +that was what we were saying when we +were talking about unlockable + + align:start position:0% +were talking about unlockable + + + align:start position:0% +were talking about unlockable +we're gonna talk about syntax the same + + align:start position:0% +we're gonna talk about syntax the same + + + align:start position:0% +we're gonna talk about syntax the same +way + + align:start position:0% +way + + + align:start position:0% +way +um yes this is a string of words however + + align:start position:0% +um yes this is a string of words however + + + align:start position:0% +um yes this is a string of words however +many words it is uh eight I guess + + align:start position:0% +many words it is uh eight I guess + + + align:start position:0% +many words it is uh eight I guess +um but there's more to say it isn't just + + align:start position:0% +um but there's more to say it isn't just + + + align:start position:0% +um but there's more to say it isn't just +a string of eight words it's a string of + + align:start position:0% +a string of eight words it's a string of + + + align:start position:0% +a string of eight words it's a string of +eight words that are composed via this + + align:start position:0% +eight words that are composed via this + + + align:start position:0% +eight words that are composed via this +pairwise operation of merge that takes + + align:start position:0% +pairwise operation of merge that takes + + + align:start position:0% +pairwise operation of merge that takes +pairs of things and puts them together + + align:start position:0% +pairs of things and puts them together + + + align:start position:0% +pairs of things and puts them together +to form larger things + + align:start position:0% +to form larger things + + + align:start position:0% +to form larger things +the other thing we said so I've just + + align:start position:0% +the other thing we said so I've just + + + align:start position:0% +the other thing we said so I've just +gotten started on building uh a + + align:start position:0% +gotten started on building uh a + + + align:start position:0% +gotten started on building uh a +syntactic structure for this sentence + + align:start position:0% +syntactic structure for this sentence + + + align:start position:0% +syntactic structure for this sentence +here by saying yeah we've got these two + + align:start position:0% +here by saying yeah we've got these two + + + align:start position:0% +here by saying yeah we've got these two +nouns book in garage which are preceded + + align:start position:0% +nouns book in garage which are preceded + + + align:start position:0% +nouns book in garage which are preceded +by determiners the which should be + + align:start position:0% +by determiners the which should be + + + align:start position:0% +by determiners the which should be +merged together with these nouns to form + + align:start position:0% +merged together with these nouns to form + + + align:start position:0% +merged together with these nouns to form +larger objects + + align:start position:0% +larger objects + + + align:start position:0% +larger objects +in the case of unlockable we were saying + + align:start position:0% +in the case of unlockable we were saying + + + align:start position:0% +in the case of unlockable we were saying +um + + align:start position:0% +um + + + align:start position:0% +um +uh affixes like un are going to come + + align:start position:0% +uh affixes like un are going to come + + + align:start position:0% +uh affixes like un are going to come +with instructions like put me together + + align:start position:0% +with instructions like put me together + + + align:start position:0% +with instructions like put me together +with a verb and I'll give you a verb + + align:start position:0% +with a verb and I'll give you a verb + + + align:start position:0% +with a verb and I'll give you a verb +right and instructions uh something + + align:start position:0% +right and instructions uh something + + + align:start position:0% +right and instructions uh something +sorry morphemes like Abel are going to + + align:start position:0% +sorry morphemes like Abel are going to + + + align:start position:0% +sorry morphemes like Abel are going to +come together with instructions that say + + align:start position:0% +come together with instructions that say + + + align:start position:0% +come together with instructions that say +put me together with a verb and I will + + align:start position:0% +put me together with a verb and I will + + + align:start position:0% +put me together with a verb and I will +give you an adjective + + align:start position:0% +give you an adjective + + + align:start position:0% +give you an adjective +and so when we put two things together + + align:start position:0% +and so when we put two things together + + + align:start position:0% +and so when we put two things together +we + + align:start position:0% +we + + + align:start position:0% +we +um we're adding these sort of putting + + align:start position:0% +um we're adding these sort of putting + + + align:start position:0% +um we're adding these sort of putting +labels on these nodes that we create we + + align:start position:0% +labels on these nodes that we create we + + + align:start position:0% +labels on these nodes that we create we +emerge in the case of morphology what + + align:start position:0% +emerge in the case of morphology what + + + align:start position:0% +emerge in the case of morphology what +label you put on the larger node is + + align:start position:0% +label you put on the larger node is + + + align:start position:0% +label you put on the larger node is +determined by the the affixes the + + align:start position:0% +determined by the the affixes the + + + align:start position:0% +determined by the the affixes the +affixes we've decided affixes have to + + align:start position:0% +affixes we've decided affixes have to + + + align:start position:0% +affixes we've decided affixes have to +come with instructions like I turn verbs + + align:start position:0% +come with instructions like I turn verbs + + + align:start position:0% +come with instructions like I turn verbs +into adjectives or I attached adjectives + + align:start position:0% +into adjectives or I attached adjectives + + + align:start position:0% +into adjectives or I attached adjectives +the result is adjective things like that + + align:start position:0% +the result is adjective things like that + + + align:start position:0% +the result is adjective things like that +for syntax similarly we're gonna + + align:start position:0% +for syntax similarly we're gonna + + + align:start position:0% +for syntax similarly we're gonna +take these pairs of things and we're + + align:start position:0% +take these pairs of things and we're + + + align:start position:0% +take these pairs of things and we're +gonna merge them together and we're + + align:start position:0% +gonna merge them together and we're + + + align:start position:0% +gonna merge them together and we're +going to give a label to the result + + align:start position:0% +going to give a label to the result + + + align:start position:0% +going to give a label to the result +in syntax the label of the result is + + align:start position:0% +in syntax the label of the result is + + + align:start position:0% +in syntax the label of the result is +always going to be the label of one of + + align:start position:0% +always going to be the label of one of + + + align:start position:0% +always going to be the label of one of +the two things that you put together + + align:start position:0% +the two things that you put together + + + align:start position:0% +the two things that you put together +so in this case here where I merged the + + align:start position:0% +so in this case here where I merged the + + + align:start position:0% +so in this case here where I merged the +book or I merged the garage + + align:start position:0% +book or I merged the garage + + + align:start position:0% +book or I merged the garage +I'm going to give the result of that the + + align:start position:0% +I'm going to give the result of that the + + + align:start position:0% +I'm going to give the result of that the +label in + + align:start position:0% +label in + + + align:start position:0% +label in +because we decided that the rules + + align:start position:0% +because we decided that the rules + + + align:start position:0% +because we decided that the rules +whatever they are for determining which + + align:start position:0% +whatever they are for determining which + + + align:start position:0% +whatever they are for determining which +things can go where + + align:start position:0% +things can go where + + + align:start position:0% +things can go where +seem to care about the N that is there + + align:start position:0% +seem to care about the N that is there + + + align:start position:0% +seem to care about the N that is there +are a variety of things take a sentence + + align:start position:0% +are a variety of things take a sentence + + + align:start position:0% +are a variety of things take a sentence +like this one there are a variety of + + align:start position:0% +like this one there are a variety of + + + align:start position:0% +like this one there are a variety of +things that can go in the slot occupied + + align:start position:0% +things that can go in the slot occupied + + + align:start position:0% +things that can go in the slot occupied +here by for example the book + + align:start position:0% +here by for example the book + + + align:start position:0% +here by for example the book +um and what they have in common is that + + align:start position:0% +um and what they have in common is that + + + align:start position:0% +um and what they have in common is that +they have nouns in them so you can say I + + align:start position:0% +they have nouns in them so you can say I + + + align:start position:0% +they have nouns in them so you can say I +will find the book in the garage you can + + align:start position:0% +will find the book in the garage you can + + + align:start position:0% +will find the book in the garage you can +say I will find books in the garage you + + align:start position:0% +say I will find books in the garage you + + + align:start position:0% +say I will find books in the garage you +can say I will find purple books in the + + align:start position:0% +can say I will find purple books in the + + + align:start position:0% +can say I will find purple books in the +garage you can say I will find the + + align:start position:0% +garage you can say I will find the + + + align:start position:0% +garage you can say I will find the +purple books about syntax in the garage + + align:start position:0% +purple books about syntax in the garage + + + align:start position:0% +purple books about syntax in the garage +or various kinds of modifiers and other + + align:start position:0% +or various kinds of modifiers and other + + + align:start position:0% +or various kinds of modifiers and other +things that you can add or not but what + + align:start position:0% +things that you can add or not but what + + + align:start position:0% +things that you can add or not but what +they all have in common is that there's + + align:start position:0% +they all have in common is that there's + + + align:start position:0% +they all have in common is that there's +a noun and so we're going to sort of + + align:start position:0% +a noun and so we're going to sort of + + + align:start position:0% +a noun and so we're going to sort of +reflect that fact by naming that larger + + align:start position:0% +reflect that fact by naming that larger + + + align:start position:0% +reflect that fact by naming that larger +object the result of merging though with + + align:start position:0% +object the result of merging though with + + + align:start position:0% +object the result of merging though with +book giving it the label in as well sort + + align:start position:0% +book giving it the label in as well sort + + + align:start position:0% +book giving it the label in as well sort +of passing on the fact that there's a + + align:start position:0% +of passing on the fact that there's a + + + align:start position:0% +of passing on the fact that there's a +noun in here + + align:start position:0% +noun in here + + + align:start position:0% +noun in here +to that node yeah + + align:start position:0% +to that node yeah + + + align:start position:0% +to that node yeah +in the case of morphology like I said we + + align:start position:0% +in the case of morphology like I said we + + + align:start position:0% +in the case of morphology like I said we +had nice clear rules for what label to + + align:start position:0% +had nice clear rules for what label to + + + align:start position:0% +had nice clear rules for what label to +put on each of these nodes the the rule + + align:start position:0% +put on each of these nodes the the rule + + + align:start position:0% +put on each of these nodes the the rule +was look at the ethics and the ethics + + align:start position:0% +was look at the ethics and the ethics + + + align:start position:0% +was look at the ethics and the ethics +will tell you what you should do so they + + align:start position:0% +will tell you what you should do so they + + + align:start position:0% +will tell you what you should do so they +have to say things like uh you know if + + align:start position:0% +have to say things like uh you know if + + + align:start position:0% +have to say things like uh you know if +you merge me with a verb the result will + + align:start position:0% +you merge me with a verb the result will + + + align:start position:0% +you merge me with a verb the result will +be a verb right or if you merge me with + + align:start position:0% +be a verb right or if you merge me with + + + align:start position:0% +be a verb right or if you merge me with +a verb the result will be an adjective + + align:start position:0% +a verb the result will be an adjective + + + align:start position:0% +a verb the result will be an adjective +uh syntacticians have not gotten that + + align:start position:0% +uh syntacticians have not gotten that + + + align:start position:0% +uh syntacticians have not gotten that +far with figuring out the rules for how + + align:start position:0% +far with figuring out the rules for how + + + align:start position:0% +far with figuring out the rules for how +to label things so I am just going to + + align:start position:0% +to label things so I am just going to + + + align:start position:0% +to label things so I am just going to +label things uh and this is a current + + align:start position:0% +label things uh and this is a current + + + align:start position:0% +label things uh and this is a current +topic of Fairly hot debate actually + + align:start position:0% +topic of Fairly hot debate actually + + + align:start position:0% +topic of Fairly hot debate actually +among syntacticians like why why are we + + align:start position:0% +among syntacticians like why why are we + + + align:start position:0% +among syntacticians like why why are we +getting the labels that we are we're + + align:start position:0% +getting the labels that we are we're + + + align:start position:0% +getting the labels that we are we're +pretty clear on what the label should be + + align:start position:0% +pretty clear on what the label should be + + + align:start position:0% +pretty clear on what the label should be +but Y is not as clear + + align:start position:0% +but Y is not as clear + + + align:start position:0% +but Y is not as clear +um so that was + + align:start position:0% +um so that was + + + align:start position:0% +um so that was +one part of the the start of building a + + align:start position:0% +one part of the the start of building a + + + align:start position:0% +one part of the the start of building a +tree for this sentence are there any + + align:start position:0% +tree for this sentence are there any + + + align:start position:0% +tree for this sentence are there any +questions about this this is all + + align:start position:0% +questions about this this is all + + + align:start position:0% +questions about this this is all +quasi-review + + align:start position:0% +quasi-review + + + align:start position:0% +quasi-review +okay so from here you know we've created + + align:start position:0% +okay so from here you know we've created + + + align:start position:0% +okay so from here you know we've created +the book and the garage + + align:start position:0% +the book and the garage + + + align:start position:0% +the book and the garage +uh we decided in the garage it's also a + + align:start position:0% +uh we decided in the garage it's also a + + + align:start position:0% +uh we decided in the garage it's also a +constituent it deserves a node it's a + + align:start position:0% +constituent it deserves a node it's a + + + align:start position:0% +constituent it deserves a node it's a +prepositional phrase so we're going to + + align:start position:0% +prepositional phrase so we're going to + + + align:start position:0% +prepositional phrase so we're going to +merge in together with the + + align:start position:0% +merge in together with the + + + align:start position:0% +merge in together with the +node that we created by that first + + align:start position:0% +node that we created by that first + + + align:start position:0% +node that we created by that first +instance of merge the garage that end + + align:start position:0% +instance of merge the garage that end + + + align:start position:0% +instance of merge the garage that end +that larger n yeah so we'll merge p with + + align:start position:0% +that larger n yeah so we'll merge p with + + + align:start position:0% +that larger n yeah so we'll merge p with +that larger n and we'll get a larger a + + align:start position:0% +that larger n and we'll get a larger a + + + align:start position:0% +that larger n and we'll get a larger a +larger P yeah phrase with the label P to + + align:start position:0% +larger P yeah phrase with the label P to + + + align:start position:0% +larger P yeah phrase with the label P to +what you could call a prepositional + + align:start position:0% +what you could call a prepositional + + + align:start position:0% +what you could call a prepositional +phrase + + align:start position:0% +phrase + + + align:start position:0% +phrase +and then we said uh similarly find we're + + align:start position:0% +and then we said uh similarly find we're + + + align:start position:0% +and then we said uh similarly find we're +going to merge find uh together first + + align:start position:0% +going to merge find uh together first + + + align:start position:0% +going to merge find uh together first +with the book and then finally merge + + align:start position:0% +with the book and then finally merge + + + align:start position:0% +with the book and then finally merge +those two things together to get this + + align:start position:0% +those two things together to get this + + + align:start position:0% +those two things together to get this +structure for for that much of the + + align:start position:0% +structure for for that much of the + + + align:start position:0% +structure for for that much of the +sentence and you know we'll stop here + + align:start position:0% +sentence and you know we'll stop here + + + align:start position:0% +sentence and you know we'll stop here +for now we're going to build the rest of + + align:start position:0% +for now we're going to build the rest of + + + align:start position:0% +for now we're going to build the rest of +the sentence in just a second and I + + align:start position:0% +the sentence in just a second and I + + + align:start position:0% +the sentence in just a second and I +think this was as far as we got and I + + align:start position:0% +think this was as far as we got and I + + + align:start position:0% +think this was as far as we got and I +said is anybody alarmed or disturbed by + + align:start position:0% +said is anybody alarmed or disturbed by + + + align:start position:0% +said is anybody alarmed or disturbed by +this and several of you raised your + + align:start position:0% +this and several of you raised your + + + align:start position:0% +this and several of you raised your +hands because in fact this is only one + + align:start position:0% +hands because in fact this is only one + + + align:start position:0% +hands because in fact this is only one +of a couple of possible structures this + + align:start position:0% +of a couple of possible structures this + + + align:start position:0% +of a couple of possible structures this +tree can have that's uh sorry this is + + align:start position:0% +tree can have that's uh sorry this is + + + align:start position:0% +tree can have that's uh sorry this is +only one of a couple of possible + + align:start position:0% +only one of a couple of possible + + + align:start position:0% +only one of a couple of possible +structures this sentence can have uh + + align:start position:0% +structures this sentence can have uh + + + align:start position:0% +structures this sentence can have uh +we're gonna sort of spend a lot of time + + align:start position:0% +we're gonna sort of spend a lot of time + + + align:start position:0% +we're gonna sort of spend a lot of time +talking about that today you were when + + align:start position:0% +talking about that today you were when + + + align:start position:0% +talking about that today you were when +the people who raised your hand last + + align:start position:0% +the people who raised your hand last + + + align:start position:0% +the people who raised your hand last +time yeah + + align:start position:0% + + + + align:start position:0% + +boat and + + align:start position:0% +boat and + + + align:start position:0% +boat and +yeah + + align:start position:0% + + + + align:start position:0% + +Okay so + + align:start position:0% +Okay so + + + align:start position:0% +Okay so +good question + + align:start position:0% +good question + + + align:start position:0% +good question +let's see if I can answer your question + + align:start position:0% +let's see if I can answer your question + + + align:start position:0% +let's see if I can answer your question +in a way that will not cause more + + align:start position:0% +in a way that will not cause more + + + align:start position:0% +in a way that will not cause more +confusion than it gets rid of + + align:start position:0% +confusion than it gets rid of + + + align:start position:0% +confusion than it gets rid of +um + + align:start position:0% +um + + + align:start position:0% +um +I have used now the phrase prepositional + + align:start position:0% +I have used now the phrase prepositional + + + align:start position:0% +I have used now the phrase prepositional +phrase a couple of times and noun phrase + + align:start position:0% +phrase a couple of times and noun phrase + + + align:start position:0% +phrase a couple of times and noun phrase +and verb phrase + + align:start position:0% +and verb phrase + + + align:start position:0% +and verb phrase +um + + align:start position:0% +um + + + align:start position:0% +um +and I'm going to dramatically introduce + + align:start position:0% +and I'm going to dramatically introduce + + + align:start position:0% +and I'm going to dramatically introduce +what those mean in just a second I think + + align:start position:0% +what those mean in just a second I think + + + align:start position:0% +what those mean in just a second I think +it's almost the next slide let me just + + align:start position:0% +it's almost the next slide let me just + + + align:start position:0% +it's almost the next slide let me just +ask you to hang on to that question it's + + align:start position:0% +ask you to hang on to that question it's + + + align:start position:0% +ask you to hang on to that question it's +a good question + + align:start position:0% +a good question + + + align:start position:0% +a good question +are there other questions about this + + align:start position:0% +are there other questions about this + + + align:start position:0% +are there other questions about this +much this far + + align:start position:0% +much this far + + + align:start position:0% +much this far +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so if you're looking at this and + + align:start position:0% +so if you're looking at this and + + + align:start position:0% +so if you're looking at this and +thinking wait wait I think of it as + + align:start position:0% +thinking wait wait I think of it as + + + align:start position:0% +thinking wait wait I think of it as +having a different structure that's a + + align:start position:0% +having a different structure that's a + + + align:start position:0% +having a different structure that's a +good thought to have hang on to that + + align:start position:0% +good thought to have hang on to that + + + align:start position:0% +good thought to have hang on to that +thought + + align:start position:0% +thought + + + align:start position:0% +thought +ah good this is the answer to uh to your + + align:start position:0% +ah good this is the answer to uh to your + + + align:start position:0% +ah good this is the answer to uh to your +I'm sorry what's your name again + + align:start position:0% +I'm sorry what's your name again + + + align:start position:0% +I'm sorry what's your name again +say it again + + align:start position:0% + + + + align:start position:0% + +um uh so he wanted to know what do you + + align:start position:0% +um uh so he wanted to know what do you + + + align:start position:0% +um uh so he wanted to know what do you +mean when you say phrase + + align:start position:0% +mean when you say phrase + + + align:start position:0% +mean when you say phrase +there's a convention + + align:start position:0% +there's a convention + + + align:start position:0% +there's a convention +um and it's really just a + + align:start position:0% +um and it's really just a + + + align:start position:0% +um and it's really just a +it's to make it easier to look at these + + align:start position:0% +it's to make it easier to look at these + + + align:start position:0% +it's to make it easier to look at these +trees + + align:start position:0% +trees + + + align:start position:0% +trees +um but it's a it's a very widespread + + align:start position:0% +um but it's a it's a very widespread + + + align:start position:0% +um but it's a it's a very widespread +convention and I'll be doing it all the + + align:start position:0% +convention and I'll be doing it all the + + + align:start position:0% +convention and I'll be doing it all the +time when I draw trees so let me let me + + align:start position:0% +time when I draw trees so let me let me + + + align:start position:0% +time when I draw trees so let me let me +sort of introduce you to it + + align:start position:0% +sort of introduce you to it + + + align:start position:0% +sort of introduce you to it +um if you have a trees or the tree we + + align:start position:0% +um if you have a trees or the tree we + + + align:start position:0% +um if you have a trees or the tree we +had before let's go back a slide + + align:start position:0% +had before let's go back a slide + + + align:start position:0% +had before let's go back a slide +tree we had before whoa + + align:start position:0% +tree we had before whoa + + + align:start position:0% +tree we had before whoa +had various nodes that have the same + + align:start position:0% +had various nodes that have the same + + + align:start position:0% +had various nodes that have the same +level there are three nodes here that + + align:start position:0% +level there are three nodes here that + + + align:start position:0% +level there are three nodes here that +have the label V for example and there + + align:start position:0% +have the label V for example and there + + + align:start position:0% +have the label V for example and there +are two nodes that have a label p and + + align:start position:0% +are two nodes that have a label p and + + + align:start position:0% +are two nodes that have a label p and +there are four that have the label in + + align:start position:0% +there are four that have the label in + + + align:start position:0% +there are four that have the label in +actually one two associated with garage + + align:start position:0% +actually one two associated with garage + + + align:start position:0% +actually one two associated with garage +and two associated with a book yeah and + + align:start position:0% +and two associated with a book yeah and + + + align:start position:0% +and two associated with a book yeah and +uh if you look at the stream it can be + + align:start position:0% +uh if you look at the stream it can be + + + align:start position:0% +uh if you look at the stream it can be +fairly confusing looking at all of these + + align:start position:0% +fairly confusing looking at all of these + + + align:start position:0% +fairly confusing looking at all of these +nodes that have identical labels you + + align:start position:0% +nodes that have identical labels you + + + align:start position:0% +nodes that have identical labels you +know so the convention one convention + + align:start position:0% +know so the convention one convention + + + align:start position:0% +know so the convention one convention +just for making it easier to look at + + align:start position:0% +just for making it easier to look at + + + align:start position:0% +just for making it easier to look at +trees is to Mark the highest node that + + align:start position:0% +trees is to Mark the highest node that + + + align:start position:0% +trees is to Mark the highest node that +has a given label when you have a + + align:start position:0% +has a given label when you have a + + + align:start position:0% +has a given label when you have a +sequence of nodes that all have the same + + align:start position:0% +sequence of nodes that all have the same + + + align:start position:0% +sequence of nodes that all have the same +label because they all started with one + + align:start position:0% +label because they all started with one + + + align:start position:0% +label because they all started with one +word and they're in sort of inheriting a + + align:start position:0% +word and they're in sort of inheriting a + + + align:start position:0% +word and they're in sort of inheriting a +label from that word when you get to the + + align:start position:0% +label from that word when you get to the + + + align:start position:0% +label from that word when you get to the +highest of those things you give it the + + align:start position:0% +highest of those things you give it the + + + align:start position:0% +highest of those things you give it the +label P where P stands for phrase + + align:start position:0% +label P where P stands for phrase + + + align:start position:0% +label P where P stands for phrase +um so uh this is the answer to get out + + align:start position:0% +um so uh this is the answer to get out + + + align:start position:0% +um so uh this is the answer to get out +his question when we say a prepositional + + align:start position:0% +his question when we say a prepositional + + + align:start position:0% +his question when we say a prepositional +phrase what we typically mean is the + + align:start position:0% +phrase what we typically mean is the + + + align:start position:0% +phrase what we typically mean is the +largest thing with the label P from a + + align:start position:0% +largest thing with the label P from a + + + align:start position:0% +largest thing with the label P from a +given from a given node so in by itself + + align:start position:0% +given from a given node so in by itself + + + align:start position:0% +given from a given node so in by itself +is a preposition and that larger thing + + align:start position:0% +is a preposition and that larger thing + + + align:start position:0% +is a preposition and that larger thing +with the label p is the prepositional + + align:start position:0% +with the label p is the prepositional + + + align:start position:0% +with the label p is the prepositional +phrase + + align:start position:0% +phrase + + + align:start position:0% +phrase +again this is just to make it easier to + + align:start position:0% +again this is just to make it easier to + + + align:start position:0% +again this is just to make it easier to +process trees so we won't see so many + + align:start position:0% +process trees so we won't see so many + + + align:start position:0% +process trees so we won't see so many +identical labels we're just putting a + + align:start position:0% +identical labels we're just putting a + + + align:start position:0% +identical labels we're just putting a +mark saying this is as far as this label + + align:start position:0% +mark saying this is as far as this label + + + align:start position:0% +mark saying this is as far as this label +got yeah that's all that means yeah + + align:start position:0% + + + + align:start position:0% + +ah so in this tree it's not because + + align:start position:0% +ah so in this tree it's not because + + + align:start position:0% +ah so in this tree it's not because +there is another thing with the label V + + align:start position:0% +there is another thing with the label V + + + align:start position:0% +there is another thing with the label V +that is higher than find the book yes + + align:start position:0% +that is higher than find the book yes + + + align:start position:0% +that is higher than find the book yes +but you are right there is another thing + + align:start position:0% +but you are right there is another thing + + + align:start position:0% +but you are right there is another thing +we do for exactly that case let me show + + align:start position:0% +we do for exactly that case let me show + + + align:start position:0% +we do for exactly that case let me show +you that a nice question allows me to + + align:start position:0% +you that a nice question allows me to + + + align:start position:0% +you that a nice question allows me to +segue nicely into the next slide we have + + align:start position:0% +segue nicely into the next slide we have + + + align:start position:0% +segue nicely into the next slide we have +another thing that we do for exactly + + align:start position:0% +another thing that we do for exactly + + + align:start position:0% +another thing that we do for exactly +that case nodes that are not that don't + + align:start position:0% +that case nodes that are not that don't + + + align:start position:0% +that case nodes that are not that don't +get the label P because they're not the + + align:start position:0% +get the label P because they're not the + + + align:start position:0% +get the label P because they're not the +highest thing + + align:start position:0% +highest thing + + + align:start position:0% +highest thing +and that also are not you know just the + + align:start position:0% +and that also are not you know just the + + + align:start position:0% +and that also are not you know just the +bare word that like find just the verb + + align:start position:0% +bare word that like find just the verb + + + align:start position:0% +bare word that like find just the verb +things that are in between like that + + align:start position:0% +things that are in between like that + + + align:start position:0% +things that are in between like that +it's sort of an unfortunate label + + align:start position:0% +it's sort of an unfortunate label + + + align:start position:0% +it's sort of an unfortunate label +um we call + + align:start position:0% +um we call + + + align:start position:0% +um we call +things like so here I'll draw it again + + align:start position:0% +things like so here I'll draw it again + + + align:start position:0% +things like so here I'll draw it again +here + + align:start position:0% +here + + + align:start position:0% +here +find the book + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% +foreign + + + align:start position:0% +foreign +okay so I won't draw the whole thing but + + align:start position:0% +okay so I won't draw the whole thing but + + + align:start position:0% +okay so I won't draw the whole thing but +uh find the book there's this thing and + + align:start position:0% +uh find the book there's this thing and + + + align:start position:0% +uh find the book there's this thing and +then there's this this is the VP because + + align:start position:0% +then there's this this is the VP because + + + align:start position:0% +then there's this this is the VP because +it's the highest thing with the label b + + align:start position:0% +it's the highest thing with the label b + + + align:start position:0% +it's the highest thing with the label b +v this is the V because it's just the + + align:start position:0% +v this is the V because it's just the + + + align:start position:0% +v this is the V because it's just the +verb it's just a word by itself and this + + align:start position:0% +verb it's just a word by itself and this + + + align:start position:0% +verb it's just a word by itself and this +thing we use a prime symbol to mark it + + align:start position:0% +thing we use a prime symbol to mark it + + + align:start position:0% +thing we use a prime symbol to mark it +and it is called a v bar + + align:start position:0% +and it is called a v bar + + + align:start position:0% +and it is called a v bar +um I'm sorry that's just the way we do + + align:start position:0% +um I'm sorry that's just the way we do + + + align:start position:0% +um I'm sorry that's just the way we do +things in syntax yeah + + align:start position:0% +things in syntax yeah + + + align:start position:0% +things in syntax yeah +um I think it's called this because it + + align:start position:0% +um I think it's called this because it + + + align:start position:0% +um I think it's called this because it +used to be that people would write it + + align:start position:0% +used to be that people would write it + + + align:start position:0% +used to be that people would write it +like this + + align:start position:0% +like this + + + align:start position:0% +like this +like with the bar over the top + + align:start position:0% +like with the bar over the top + + + align:start position:0% +like with the bar over the top +this was in like the I don't know 1960s + + align:start position:0% +this was in like the I don't know 1960s + + + align:start position:0% +this was in like the I don't know 1960s +1970s people began doing this and I + + align:start position:0% +1970s people began doing this and I + + + align:start position:0% +1970s people began doing this and I +think people were literally using + + align:start position:0% +think people were literally using + + + align:start position:0% +think people were literally using +typewriters to like go back and and do + + align:start position:0% +typewriters to like go back and and do + + + align:start position:0% +typewriters to like go back and and do +an underscore over the top of the V or + + align:start position:0% +an underscore over the top of the V or + + + align:start position:0% +an underscore over the top of the V or +something like that to me I think that's + + align:start position:0% +something like that to me I think that's + + + align:start position:0% +something like that to me I think that's +what they were doing with sort of stone + + align:start position:0% +what they were doing with sort of stone + + + align:start position:0% +what they were doing with sort of stone +age uh word processing technology + + align:start position:0% +age uh word processing technology + + + align:start position:0% +age uh word processing technology +um so the result of all that is that + + align:start position:0% +um so the result of all that is that + + + align:start position:0% +um so the result of all that is that +although nobody writes the bar + + align:start position:0% +although nobody writes the bar + + + align:start position:0% +although nobody writes the bar +typical you will sometimes see this in + + align:start position:0% +typical you will sometimes see this in + + + align:start position:0% +typical you will sometimes see this in +textbooks and things like that it's not + + align:start position:0% +textbooks and things like that it's not + + + align:start position:0% +textbooks and things like that it's not +very common but people much more + + align:start position:0% +very common but people much more + + + align:start position:0% +very common but people much more +commonly do is just write V Prime but it + + align:start position:0% +commonly do is just write V Prime but it + + + align:start position:0% +commonly do is just write V Prime but it +is never ever called V Prime it's always + + align:start position:0% +is never ever called V Prime it's always + + + align:start position:0% +is never ever called V Prime it's always +called V bar if you tell a syntactician + + align:start position:0% +called V bar if you tell a syntactician + + + align:start position:0% +called V bar if you tell a syntactician +you know find me the V Prime node the + + align:start position:0% +you know find me the V Prime node the + + + align:start position:0% +you know find me the V Prime node the +syntactician will not know what you're + + align:start position:0% +syntactician will not know what you're + + + align:start position:0% +syntactician will not know what you're +talking about sorry yeah + + align:start position:0% + + + + align:start position:0% + +so you find the book in industry + + align:start position:0% +so you find the book in industry + + + align:start position:0% +so you find the book in industry +um + + align:start position:0% +um + + + align:start position:0% +um +so it's a it's a I'm sorry can you ask + + align:start position:0% +so it's a it's a I'm sorry can you ask + + + align:start position:0% +so it's a it's a I'm sorry can you ask +your question again yeah + + align:start position:0% + + + + align:start position:0% + +great + + align:start position:0% + + + + align:start position:0% + +so if this sentence ended with find the + + align:start position:0% +so if this sentence ended with find the + + + align:start position:0% +so if this sentence ended with find the +book if it were I will find the book + + align:start position:0% +book if it were I will find the book + + + align:start position:0% +book if it were I will find the book +then find the book would be a verb + + align:start position:0% +then find the book would be a verb + + + align:start position:0% +then find the book would be a verb +phrase yes yeah + + align:start position:0% +phrase yes yeah + + + align:start position:0% +phrase yes yeah +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um + + align:start position:0% +um + + + align:start position:0% +um +uh phrase is just the name for the + + align:start position:0% +uh phrase is just the name for the + + + align:start position:0% +uh phrase is just the name for the +highest thing with that label right so + + align:start position:0% +highest thing with that label right so + + + align:start position:0% +highest thing with that label right so +just like uh + + align:start position:0% +just like uh + + + align:start position:0% +just like uh +um + + align:start position:0% +um + + + align:start position:0% +um +uh in the book yeah the book is a noun + + align:start position:0% +uh in the book yeah the book is a noun + + + align:start position:0% +uh in the book yeah the book is a noun +phrase uh if you had something uh and + + align:start position:0% +phrase uh if you had something uh and + + + align:start position:0% +phrase uh if you had something uh and +and book is not a noun phrase it's just + + align:start position:0% +and book is not a noun phrase it's just + + + align:start position:0% +and book is not a noun phrase it's just +an N so they're there are places where + + align:start position:0% +an N so they're there are places where + + + align:start position:0% +an N so they're there are places where +you don't get a bar just because you + + align:start position:0% +you don't get a bar just because you + + + align:start position:0% +you don't get a bar just because you +only have two things with that label + + align:start position:0% +only have two things with that label + + + align:start position:0% +only have two things with that label +again and then there's the NP + + align:start position:0% +again and then there's the NP + + + align:start position:0% +again and then there's the NP +um in this particular case you're + + align:start position:0% +um in this particular case you're + + + align:start position:0% +um in this particular case you're +getting a bar because there are three + + align:start position:0% +getting a bar because there are three + + + align:start position:0% +getting a bar because there are three +things with the label uh the label V and + + align:start position:0% +things with the label uh the label V and + + + align:start position:0% +things with the label uh the label V and +if there were more things if this verb + + align:start position:0% +if there were more things if this verb + + + align:start position:0% +if there were more things if this verb +phrase were more complicated you could + + align:start position:0% +phrase were more complicated you could + + + align:start position:0% +phrase were more complicated you could +end up with a bunch of bars in between + + align:start position:0% +end up with a bunch of bars in between + + + align:start position:0% +end up with a bunch of bars in between +the verb and the VP in general you're + + align:start position:0% +the verb and the VP in general you're + + + align:start position:0% +the verb and the VP in general you're +going to get one p up at the top and one + + align:start position:0% +going to get one p up at the top and one + + + align:start position:0% +going to get one p up at the top and one +thing with no extra doohickey down at + + align:start position:0% +thing with no extra doohickey down at + + + align:start position:0% +thing with no extra doohickey down at +the bottom so just V and everything in + + align:start position:0% +the bottom so just V and everything in + + + align:start position:0% +the bottom so just V and everything in +between it will be bar + + align:start position:0% +between it will be bar + + + align:start position:0% +between it will be bar +again this is all just conventions this + + align:start position:0% +again this is all just conventions this + + + align:start position:0% +again this is all just conventions this +is not meant to reflect anything deep + + align:start position:0% +is not meant to reflect anything deep + + + align:start position:0% +is not meant to reflect anything deep +it's it's meant to make it possible for + + align:start position:0% +it's it's meant to make it possible for + + + align:start position:0% +it's it's meant to make it possible for +human beings to look at these trees and + + align:start position:0% +human beings to look at these trees and + + + align:start position:0% +human beings to look at these trees and +process the + + align:start position:0% + + + + align:start position:0% + +Raquel + + align:start position:0% + + + + align:start position:0% + +we squish multiple verbs together yep + + align:start position:0% + + + + align:start position:0% + +we have not gotten there but you're + + align:start position:0% +we have not gotten there but you're + + + align:start position:0% +we have not gotten there but you're +right and so Raquel wants to know what + + align:start position:0% +right and so Raquel wants to know what + + + align:start position:0% +right and so Raquel wants to know what +am I going to do with I will and I will + + align:start position:0% +am I going to do with I will and I will + + + align:start position:0% +am I going to do with I will and I will +I will tell you what I'm going to do + + align:start position:0% +I will tell you what I'm going to do + + + align:start position:0% +I will tell you what I'm going to do +with that so we will give will its own + + align:start position:0% +with that so we will give will its own + + + align:start position:0% +with that so we will give will its own +label in just a second good question + + align:start position:0% +label in just a second good question + + + align:start position:0% +label in just a second good question +other questions about this + + align:start position:0% +other questions about this + + + align:start position:0% +other questions about this +usually clear okay + + align:start position:0% +usually clear okay + + + align:start position:0% +usually clear okay +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% + + + + align:start position:0% + +yeah okay so again p is the marker for + + align:start position:0% +yeah okay so again p is the marker for + + + align:start position:0% +yeah okay so again p is the marker for +the highest thing with a given label uh + + align:start position:0% +the highest thing with a given label uh + + + align:start position:0% +the highest thing with a given label uh +the lowest thing with again in the label + + align:start position:0% +the lowest thing with again in the label + + + align:start position:0% +the lowest thing with again in the label +doesn't get a mark sometimes when people + + align:start position:0% +doesn't get a mark sometimes when people + + + align:start position:0% +doesn't get a mark sometimes when people +want to make it clear that it's not a + + align:start position:0% +want to make it clear that it's not a + + + align:start position:0% +want to make it clear that it's not a +bar and it's not a p they'll put a + + align:start position:0% +bar and it's not a p they'll put a + + + align:start position:0% +bar and it's not a p they'll put a +little raised zero on it I won't do that + + align:start position:0% +little raised zero on it I won't do that + + + align:start position:0% +little raised zero on it I won't do that +but you'll see people do that sometimes + + align:start position:0% +but you'll see people do that sometimes + + + align:start position:0% +but you'll see people do that sometimes +uh so you've got the the unmarked thing + + align:start position:0% +uh so you've got the the unmarked thing + + + align:start position:0% +uh so you've got the the unmarked thing +that's the word itself you've got the P + + align:start position:0% +that's the word itself you've got the P + + + align:start position:0% +that's the word itself you've got the P +that's the highest thing and everything + + align:start position:0% +that's the highest thing and everything + + + align:start position:0% +that's the highest thing and everything +else is a bar one consequence of all + + align:start position:0% +else is a bar one consequence of all + + + align:start position:0% +else is a bar one consequence of all +this actually is that there are things + + align:start position:0% +this actually is that there are things + + + align:start position:0% +this actually is that there are things +which are sort of you know both phrases + + align:start position:0% +which are sort of you know both phrases + + + align:start position:0% +which are sort of you know both phrases +and heads uh + + align:start position:0% +and heads uh + + + align:start position:0% +and heads uh +sort of connected to get eyes question + + align:start position:0% +sort of connected to get eyes question + + + align:start position:0% +sort of connected to get eyes question +from a little while ago so the D the + + align:start position:0% +from a little while ago so the D the + + + align:start position:0% +from a little while ago so the D the +industry both of the instances of D the + + align:start position:0% +industry both of the instances of D the + + + align:start position:0% +industry both of the instances of D the +in this tree they are the lowest thing + + align:start position:0% +in this tree they are the lowest thing + + + align:start position:0% +in this tree they are the lowest thing +with the label D so they're they don't + + align:start position:0% +with the label D so they're they don't + + + align:start position:0% +with the label D so they're they don't +get marked they're also the highest + + align:start position:0% +get marked they're also the highest + + + align:start position:0% +get marked they're also the highest +thing with the label D yeah neither of + + align:start position:0% +thing with the label D yeah neither of + + + align:start position:0% +thing with the label D yeah neither of +them + + align:start position:0% +them + + + align:start position:0% +them +is higher than the other they're just + + align:start position:0% +is higher than the other they're just + + + align:start position:0% +is higher than the other they're just +two instances of d + + align:start position:0% +two instances of d + + + align:start position:0% +two instances of d +and so + + align:start position:0% +and so + + + align:start position:0% +and so +um a a influential school of thought + + align:start position:0% +um a a influential school of thought + + + align:start position:0% +um a a influential school of thought +about what's going on in cases like that + + align:start position:0% +about what's going on in cases like that + + + align:start position:0% +about what's going on in cases like that +is to say yeah those are both phrases + + align:start position:0% +is to say yeah those are both phrases + + + align:start position:0% +is to say yeah those are both phrases +and not phrases uh try not to be too + + align:start position:0% +and not phrases uh try not to be too + + + align:start position:0% +and not phrases uh try not to be too +uptight about these labels + + align:start position:0% +uptight about these labels + + + align:start position:0% +uptight about these labels +talk about them anyway + + align:start position:0% +talk about them anyway + + + align:start position:0% +talk about them anyway +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right so + + align:start position:0% +all right so + + + align:start position:0% +all right so +now uh + + align:start position:0% +now uh + + + align:start position:0% +now uh +I drew you a tree and some of you last + + align:start position:0% +I drew you a tree and some of you last + + + align:start position:0% +I drew you a tree and some of you last +time rejected I drew you a tree in which + + align:start position:0% +time rejected I drew you a tree in which + + + align:start position:0% +time rejected I drew you a tree in which +a prepositional phrase was modifying a + + align:start position:0% +a prepositional phrase was modifying a + + + align:start position:0% +a prepositional phrase was modifying a +verb phrase + + align:start position:0% +verb phrase + + + align:start position:0% +verb phrase +that's I'll show you the tree again + + align:start position:0% +that's I'll show you the tree again + + + align:start position:0% +that's I'll show you the tree again +you've got a prepositional phrase in the + + align:start position:0% +you've got a prepositional phrase in the + + + align:start position:0% +you've got a prepositional phrase in the +garage and I've got that prepositional + + align:start position:0% +garage and I've got that prepositional + + + align:start position:0% +garage and I've got that prepositional +phrase + + align:start position:0% +phrase + + + align:start position:0% +phrase +merged together with something with the + + align:start position:0% +merged together with something with the + + + align:start position:0% +merged together with something with the +label V that's a prepositional phrase + + align:start position:0% +label V that's a prepositional phrase + + + align:start position:0% +label V that's a prepositional phrase +that's telling you where the finding of + + align:start position:0% +that's telling you where the finding of + + + align:start position:0% +that's telling you where the finding of +the book is going to take place it's + + align:start position:0% +the book is going to take place it's + + + align:start position:0% +the book is going to take place it's +going to take place in the garage + + align:start position:0% + + + + align:start position:0% + +now prepositional phrases can also + + align:start position:0% +now prepositional phrases can also + + + align:start position:0% +now prepositional phrases can also +modify noun phrases you can say things + + align:start position:0% +modify noun phrases you can say things + + + align:start position:0% +modify noun phrases you can say things +like I will find books about syntax + + align:start position:0% +like I will find books about syntax + + + align:start position:0% +like I will find books about syntax +where about syntax is telling you what + + align:start position:0% +where about syntax is telling you what + + + align:start position:0% +where about syntax is telling you what +kinds of books you're going to find + + align:start position:0% +kinds of books you're going to find + + + align:start position:0% +kinds of books you're going to find +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +now this is just some consequences of + + align:start position:0% +now this is just some consequences of + + + align:start position:0% +now this is just some consequences of +that + + align:start position:0% +that + + + align:start position:0% +that +we should we can think about + + align:start position:0% +we should we can think about + + + align:start position:0% +we should we can think about +first + + align:start position:0% +first + + + align:start position:0% +first +we've said that noun phrases can contain + + align:start position:0% +we've said that noun phrases can contain + + + align:start position:0% +we've said that noun phrases can contain +prepositional phrases books about syntax + + align:start position:0% +prepositional phrases books about syntax + + + align:start position:0% +prepositional phrases books about syntax +and we know that prepositional phrases + + align:start position:0% +and we know that prepositional phrases + + + align:start position:0% +and we know that prepositional phrases +can contain noun phrases + + align:start position:0% +can contain noun phrases + + + align:start position:0% +can contain noun phrases +which can contain prepositional phrases + + align:start position:0% +which can contain prepositional phrases + + + align:start position:0% +which can contain prepositional phrases +which can contain noun phrases + + align:start position:0% +which can contain noun phrases + + + align:start position:0% +which can contain noun phrases +so there is no reason to ever stop + + align:start position:0% +so there is no reason to ever stop + + + align:start position:0% +so there is no reason to ever stop +talking we talked about this when we + + align:start position:0% +talking we talked about this when we + + + align:start position:0% +talking we talked about this when we +were talking about + + align:start position:0% +were talking about + + + align:start position:0% +were talking about +um I'm wearing my mask again we talked + + align:start position:0% +um I'm wearing my mask again we talked + + + align:start position:0% +um I'm wearing my mask again we talked +about this when we were talking about uh + + align:start position:0% +about this when we were talking about uh + + + align:start position:0% +about this when we were talking about uh +um the competence performance + + align:start position:0% +um the competence performance + + + align:start position:0% +um the competence performance +distinction the fact that we're + + align:start position:0% +distinction the fact that we're + + + align:start position:0% +distinction the fact that we're +sort of idealizing the actual kinds of + + align:start position:0% +sort of idealizing the actual kinds of + + + align:start position:0% +sort of idealizing the actual kinds of +sentences that people say + + align:start position:0% +sentences that people say + + + align:start position:0% +sentences that people say +um + + align:start position:0% +um + + + align:start position:0% +um +uh here's another case of this so you + + align:start position:0% +uh here's another case of this so you + + + align:start position:0% +uh here's another case of this so you +can have a book about Islands you can + + align:start position:0% +can have a book about Islands you can + + + align:start position:0% +can have a book about Islands you can +have a book about Islands on lakes you + + align:start position:0% +have a book about Islands on lakes you + + + align:start position:0% +have a book about Islands on lakes you +can have a book about Islands on lakes + + align:start position:0% +can have a book about Islands on lakes + + + align:start position:0% +can have a book about Islands on lakes +on Islands you can have a book about + + align:start position:0% +on Islands you can have a book about + + + align:start position:0% +on Islands you can have a book about +Islands on lakes on Islands on lakes and + + align:start position:0% +Islands on lakes on Islands on lakes and + + + align:start position:0% +Islands on lakes on Islands on lakes and +so on eventually you will run out of + + align:start position:0% +so on eventually you will run out of + + + align:start position:0% +so on eventually you will run out of +things that your book can be about if + + align:start position:0% +things that your book can be about if + + + align:start position:0% +things that your book can be about if +you keep repeating this but that is a + + align:start position:0% +you keep repeating this but that is a + + + align:start position:0% +you keep repeating this but that is a +fact about geography this is not a + + align:start position:0% +fact about geography this is not a + + + align:start position:0% +fact about geography this is not a +geography class + + align:start position:0% +geography class + + + align:start position:0% +geography class +there actually is a website or used to + + align:start position:0% +there actually is a website or used to + + + align:start position:0% +there actually is a website or used to +be that listed you know the largest + + align:start position:0% +be that listed you know the largest + + + align:start position:0% +be that listed you know the largest +island on a lake and then the largest + + align:start position:0% +island on a lake and then the largest + + + align:start position:0% +island on a lake and then the largest +island on the lake on an island the + + align:start position:0% +island on the lake on an island the + + + align:start position:0% +island on the lake on an island the +largest island on the lake on an island + + align:start position:0% +largest island on the lake on an island + + + align:start position:0% +largest island on the lake on an island +on the lake it's kind of cool website + + align:start position:0% +on the lake it's kind of cool website + + + align:start position:0% +on the lake it's kind of cool website +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +there's a lot of a lot of stuff going + + align:start position:0% +there's a lot of a lot of stuff going + + + align:start position:0% +there's a lot of a lot of stuff going +around Lake Al in the Philippines I + + align:start position:0% +around Lake Al in the Philippines I + + + align:start position:0% +around Lake Al in the Philippines I +remember + + align:start position:0% +remember + + + align:start position:0% +remember +um yeah is this clear so this is another + + align:start position:0% +um yeah is this clear so this is another + + + align:start position:0% +um yeah is this clear so this is another +I just said this is another instance + + align:start position:0% +I just said this is another instance + + + align:start position:0% +I just said this is another instance +where we might want to care about the + + align:start position:0% +where we might want to care about the + + + align:start position:0% +where we might want to care about the +difference between competence and + + align:start position:0% +difference between competence and + + + align:start position:0% +difference between competence and +performance + + align:start position:0% +performance + + + align:start position:0% +performance +um we've got a theory that we're + + align:start position:0% +um we've got a theory that we're + + + align:start position:0% +um we've got a theory that we're +starting to build about syntax that + + align:start position:0% +starting to build about syntax that + + + align:start position:0% +starting to build about syntax that +makes it possible for noun phrases to be + + align:start position:0% +makes it possible for noun phrases to be + + + align:start position:0% +makes it possible for noun phrases to be +arbitrarily long + + align:start position:0% +arbitrarily long + + + align:start position:0% +arbitrarily long +no one's ever going to utter an + + align:start position:0% +no one's ever going to utter an + + + align:start position:0% +no one's ever going to utter an +arbitrarily long noun phrase nobody's + + align:start position:0% +arbitrarily long noun phrase nobody's + + + align:start position:0% +arbitrarily long noun phrase nobody's +gonna keep talking as long as this + + align:start position:0% +gonna keep talking as long as this + + + align:start position:0% +gonna keep talking as long as this +grammar would allow you to but that's a + + align:start position:0% +grammar would allow you to but that's a + + + align:start position:0% +grammar would allow you to but that's a +fact about as I said geography and you + + align:start position:0% +fact about as I said geography and you + + + align:start position:0% +fact about as I said geography and you +know life uh people have better things + + align:start position:0% +know life uh people have better things + + + align:start position:0% +know life uh people have better things +to do than to continue + + align:start position:0% +to do than to continue + + + align:start position:0% +to do than to continue +um repeating these things yeah + + align:start position:0% +um repeating these things yeah + + + align:start position:0% +um repeating these things yeah +but it's clear uh we we want a grammar + + align:start position:0% +but it's clear uh we we want a grammar + + + align:start position:0% +but it's clear uh we we want a grammar +that allows this + + align:start position:0% +that allows this + + + align:start position:0% +that allows this +so yeah you couldn't actually utter an + + align:start position:0% +so yeah you couldn't actually utter an + + + align:start position:0% +so yeah you couldn't actually utter an +infinitely long noun phrase but we now + + align:start position:0% +infinitely long noun phrase but we now + + + align:start position:0% +infinitely long noun phrase but we now +have a grammar that's capable of + + align:start position:0% +have a grammar that's capable of + + + align:start position:0% +have a grammar that's capable of +producing one + + align:start position:0% +producing one + + + align:start position:0% +producing one +another thing that it gets us and this + + align:start position:0% +another thing that it gets us and this + + + align:start position:0% +another thing that it gets us and this +is sort of the heart of the the reaction + + align:start position:0% +is sort of the heart of the the reaction + + + align:start position:0% +is sort of the heart of the the reaction +that I was getting last time when I I + + align:start position:0% +that I was getting last time when I I + + + align:start position:0% +that I was getting last time when I I +showed you the tree that I wanted to do + + align:start position:0% +showed you the tree that I wanted to do + + + align:start position:0% +showed you the tree that I wanted to do +for that sentence + + align:start position:0% +for that sentence + + + align:start position:0% +for that sentence +um is that there are cases of ambiguity + + align:start position:0% +um is that there are cases of ambiguity + + + align:start position:0% +um is that there are cases of ambiguity +so this is a classic Marx Brothers line + + align:start position:0% +so this is a classic Marx Brothers line + + + align:start position:0% +so this is a classic Marx Brothers line +uh in animal crackers I think uh Groucho + + align:start position:0% +uh in animal crackers I think uh Groucho + + + align:start position:0% +uh in animal crackers I think uh Groucho +Mark says to someone uh I shot an I once + + align:start position:0% +Mark says to someone uh I shot an I once + + + align:start position:0% +Mark says to someone uh I shot an I once +shot an elephant in my pajamas + + align:start position:0% +shot an elephant in my pajamas + + + align:start position:0% +shot an elephant in my pajamas +pause and he says how he got in my + + align:start position:0% +pause and he says how he got in my + + + align:start position:0% +pause and he says how he got in my +pajamas I'll never know + + align:start position:0% +pajamas I'll never know + + + align:start position:0% +pajamas I'll never know +um + + align:start position:0% +um + + + align:start position:0% +um +so Groucho Marx here is making use of + + align:start position:0% +so Groucho Marx here is making use of + + + align:start position:0% +so Groucho Marx here is making use of +the ambiguity of the original sentence I + + align:start position:0% +the ambiguity of the original sentence I + + + align:start position:0% +the ambiguity of the original sentence I +shot an elephant in my pajamas uh has + + align:start position:0% +shot an elephant in my pajamas uh has + + + align:start position:0% +shot an elephant in my pajamas uh has +two things that could in principle mean + + align:start position:0% +two things that could in principle mean + + + align:start position:0% +two things that could in principle mean +um it could mean I shot an elephant + + align:start position:0% +um it could mean I shot an elephant + + + align:start position:0% +um it could mean I shot an elephant +while I was so here's in my pajamas + + align:start position:0% +while I was so here's in my pajamas + + + align:start position:0% +while I was so here's in my pajamas +um uh the prepositional phrase in my + + align:start position:0% +um uh the prepositional phrase in my + + + align:start position:0% +um uh the prepositional phrase in my +pajamas could modify the elephant that + + align:start position:0% +pajamas could modify the elephant that + + + align:start position:0% +pajamas could modify the elephant that +is it could be that it was the elephant + + align:start position:0% +is it could be that it was the elephant + + + align:start position:0% +is it could be that it was the elephant +who was wearing the pajamas + + align:start position:0% +who was wearing the pajamas + + + align:start position:0% +who was wearing the pajamas +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +I shot an elephant in my pajamas or uh + + align:start position:0% +I shot an elephant in my pajamas or uh + + + align:start position:0% +I shot an elephant in my pajamas or uh +it could be that we put together shoot + + align:start position:0% +it could be that we put together shoot + + + align:start position:0% +it could be that we put together shoot +an elephant and then we uh merge in my + + align:start position:0% +an elephant and then we uh merge in my + + + align:start position:0% +an elephant and then we uh merge in my +pajamas with that right so that in my + + align:start position:0% +pajamas with that right so that in my + + + align:start position:0% +pajamas with that right so that in my +pajamas is modifying the way in which I + + align:start position:0% +pajamas is modifying the way in which I + + + align:start position:0% +pajamas is modifying the way in which I +shot an elephant that is I shot an + + align:start position:0% +shot an elephant that is I shot an + + + align:start position:0% +shot an elephant that is I shot an +elephant while I was wearing my pajamas + + align:start position:0% +elephant while I was wearing my pajamas + + + align:start position:0% +elephant while I was wearing my pajamas +so I shot an elephant in my pajamas it's + + align:start position:0% +so I shot an elephant in my pajamas it's + + + align:start position:0% +so I shot an elephant in my pajamas it's +an ambiguous sentence it could mean + + align:start position:0% +an ambiguous sentence it could mean + + + align:start position:0% +an ambiguous sentence it could mean +either + + align:start position:0% +either + + + align:start position:0% +either +I was wearing pajamas or the elephant + + align:start position:0% +I was wearing pajamas or the elephant + + + align:start position:0% +I was wearing pajamas or the elephant +was wearing pajamas no + + align:start position:0% +was wearing pajamas no + + + align:start position:0% +was wearing pajamas no +do people get that ambiguity yeah + + align:start position:0% +do people get that ambiguity yeah + + + align:start position:0% +do people get that ambiguity yeah +um it's a classic joke uh it's odd that + + align:start position:0% +um it's a classic joke uh it's odd that + + + align:start position:0% +um it's a classic joke uh it's odd that +we enjoy this uh there's a lot of humor + + align:start position:0% +we enjoy this uh there's a lot of humor + + + align:start position:0% +we enjoy this uh there's a lot of humor +that has this shape where uh someone + + align:start position:0% +that has this shape where uh someone + + + align:start position:0% +that has this shape where uh someone +says an ambiguous sentence that has one + + align:start position:0% +says an ambiguous sentence that has one + + + align:start position:0% +says an ambiguous sentence that has one +normal meaning and one strange meaning + + align:start position:0% +normal meaning and one strange meaning + + + align:start position:0% +normal meaning and one strange meaning +and then they the punch line reveals + + align:start position:0% +and then they the punch line reveals + + + align:start position:0% +and then they the punch line reveals +that they meant the strange meaning + + align:start position:0% +that they meant the strange meaning + + + align:start position:0% +that they meant the strange meaning +that's the form of this joke I shot an + + align:start position:0% +that's the form of this joke I shot an + + + align:start position:0% +that's the form of this joke I shot an +elephant in my pajamas you of course + + align:start position:0% +elephant in my pajamas you of course + + + align:start position:0% +elephant in my pajamas you of course +think that he means he was wearing his + + align:start position:0% +think that he means he was wearing his + + + align:start position:0% +think that he means he was wearing his +pajamas and then he reveals that no it + + align:start position:0% +pajamas and then he reveals that no it + + + align:start position:0% +pajamas and then he reveals that no it +was the elephant that was wearing the + + align:start position:0% +was the elephant that was wearing the + + + align:start position:0% +was the elephant that was wearing the +pajamas and then everybody laughs + + align:start position:0% +pajamas and then everybody laughs + + + align:start position:0% +pajamas and then everybody laughs +as I said it's odd that we I mean + + align:start position:0% +as I said it's odd that we I mean + + + align:start position:0% +as I said it's odd that we I mean +normally being told haha you + + align:start position:0% +normally being told haha you + + + align:start position:0% +normally being told haha you +misunderstood me that's not that's not + + align:start position:0% +misunderstood me that's not that's not + + + align:start position:0% +misunderstood me that's not that's not +fun you know but uh we actually pay + + align:start position:0% +fun you know but uh we actually pay + + + align:start position:0% +fun you know but uh we actually pay +people to do this + + align:start position:0% +people to do this + + + align:start position:0% +people to do this +it's kind of strange yeah + + align:start position:0% + + + + align:start position:0% + +uh-huh yeah + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +I know it's interesting that you have + + align:start position:0% +I know it's interesting that you have + + + align:start position:0% +I know it's interesting that you have +this this I mean right now what we have + + align:start position:0% +this this I mean right now what we have + + + align:start position:0% +this this I mean right now what we have +is just a grammar that predicts that it + + align:start position:0% +is just a grammar that predicts that it + + + align:start position:0% +is just a grammar that predicts that it +could mean either of those things right + + align:start position:0% +could mean either of those things right + + + align:start position:0% +could mean either of those things right +so uh that prepositional phrase in my + + align:start position:0% +so uh that prepositional phrase in my + + + align:start position:0% +so uh that prepositional phrase in my +pajamas can be merged in a couple + + align:start position:0% +pajamas can be merged in a couple + + + align:start position:0% +pajamas can be merged in a couple +different places and and the + + align:start position:0% +different places and and the + + + align:start position:0% +different places and and the +consequences that it could mean a couple + + align:start position:0% +consequences that it could mean a couple + + + align:start position:0% +consequences that it could mean a couple +different things you're absolutely right + + align:start position:0% +different things you're absolutely right + + + align:start position:0% +different things you're absolutely right +that the tree on the left is prettier + + align:start position:0% +that the tree on the left is prettier + + + align:start position:0% +that the tree on the left is prettier +than the tree on the right + + align:start position:0% +than the tree on the right + + + align:start position:0% +than the tree on the right +um and people who work on how people + + align:start position:0% +um and people who work on how people + + + align:start position:0% +um and people who work on how people +deal with ambiguities like this in real + + align:start position:0% +deal with ambiguities like this in real + + + align:start position:0% +deal with ambiguities like this in real +time this is something people work on + + align:start position:0% +time this is something people work on + + + align:start position:0% +time this is something people work on +sort of processing + + align:start position:0% +sort of processing + + + align:start position:0% +sort of processing +um uh develop theories about where the + + align:start position:0% +um uh develop theories about where the + + + align:start position:0% +um uh develop theories about where the +preferences are for where prepositional + + align:start position:0% +preferences are for where prepositional + + + align:start position:0% +preferences are for where prepositional +phrases should be attached in a place + + align:start position:0% +phrases should be attached in a place + + + align:start position:0% +phrases should be attached in a place +like this whether there's a preference + + align:start position:0% +like this whether there's a preference + + + align:start position:0% +like this whether there's a preference +for the for trees like the tree on the + + align:start position:0% +for the for trees like the tree on the + + + align:start position:0% +for the for trees like the tree on the +left or trees like the tree on the right + + align:start position:0% +left or trees like the tree on the right + + + align:start position:0% +left or trees like the tree on the right +I think there isn't supposed to be a + + align:start position:0% +I think there isn't supposed to be a + + + align:start position:0% +I think there isn't supposed to be a +general preference for uh uh trees like + + align:start position:0% +general preference for uh uh trees like + + + align:start position:0% +general preference for uh uh trees like +the tree on the left + + align:start position:0% +the tree on the left + + + align:start position:0% +the tree on the left +um I think this is just supposed to be a + + align:start position:0% +um I think this is just supposed to be a + + + align:start position:0% +um I think this is just supposed to be a +case where in principle it's ambiguous + + align:start position:0% +case where in principle it's ambiguous + + + align:start position:0% +case where in principle it's ambiguous +and um you know but people who work on + + align:start position:0% +and um you know but people who work on + + + align:start position:0% +and um you know but people who work on +processing have found places where + + align:start position:0% +processing have found places where + + + align:start position:0% +processing have found places where +there's a preference for one kind of + + align:start position:0% +there's a preference for one kind of + + + align:start position:0% +there's a preference for one kind of +tree over another so that is something + + align:start position:0% +tree over another so that is something + + + align:start position:0% +tree over another so that is something +people + + align:start position:0% +people + + + align:start position:0% +people +freak out + + align:start position:0% + + + + align:start position:0% + +yep + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +NP down there if there's like another + + align:start position:0% +NP down there if there's like another + + + align:start position:0% +NP down there if there's like another +entry yeah so yeah that's a very good + + align:start position:0% +entry yeah so yeah that's a very good + + + align:start position:0% +entry yeah so yeah that's a very good +point uh when I said before that you + + align:start position:0% +point uh when I said before that you + + + align:start position:0% +point uh when I said before that you +give P to the highest thing with a given + + align:start position:0% +give P to the highest thing with a given + + + align:start position:0% +give P to the highest thing with a given +label I should have said something + + align:start position:0% +label I should have said something + + + align:start position:0% +label I should have said something +something more sophisticated something + + align:start position:0% +something more sophisticated something + + + align:start position:0% +something more sophisticated something +like you give P to the highest thing + + align:start position:0% +like you give P to the highest thing + + + align:start position:0% +like you give P to the highest thing +with a given label that is produced or + + align:start position:0% +with a given label that is produced or + + + align:start position:0% +with a given label that is produced or +that is being projected from a given + + align:start position:0% +that is being projected from a given + + + align:start position:0% +that is being projected from a given +head from a given word + + align:start position:0% +head from a given word + + + align:start position:0% +head from a given word +so uh this so my pajamas is an NP + + align:start position:0% +so uh this so my pajamas is an NP + + + align:start position:0% +so uh this so my pajamas is an NP +because it's the highest node that has + + align:start position:0% +because it's the highest node that has + + + align:start position:0% +because it's the highest node that has +an N that comes from pajamas yeah and + + align:start position:0% +an N that comes from pajamas yeah and + + + align:start position:0% +an N that comes from pajamas yeah and +then there's a higher NP uh that's uh + + align:start position:0% +then there's a higher NP uh that's uh + + + align:start position:0% +then there's a higher NP uh that's uh +right under the VP right that you merge + + align:start position:0% +right under the VP right that you merge + + + align:start position:0% +right under the VP right that you merge +together with the verb and that's an NP + + align:start position:0% +together with the verb and that's an NP + + + align:start position:0% +together with the verb and that's an NP +that's got its label from elephants + + align:start position:0% +that's got its label from elephants + + + align:start position:0% +that's got its label from elephants +so there are two NPS here one of them + + align:start position:0% +so there are two NPS here one of them + + + align:start position:0% +so there are two NPS here one of them +coming from pajamas and the other coming + + align:start position:0% +coming from pajamas and the other coming + + + align:start position:0% +coming from pajamas and the other coming +from elephant that's a very good point + + align:start position:0% +from elephant that's a very good point + + + align:start position:0% +from elephant that's a very good point +what you're pointing out is that when I + + align:start position:0% +what you're pointing out is that when I + + + align:start position:0% +what you're pointing out is that when I +said the highest thing with the label n + + align:start position:0% +said the highest thing with the label n + + + align:start position:0% +said the highest thing with the label n +uh it was being too fast + + align:start position:0% +uh it was being too fast + + + align:start position:0% +uh it was being too fast +the highest thing with a given label n + + align:start position:0% +the highest thing with a given label n + + + align:start position:0% +the highest thing with a given label n +and we have to distinguish n's from each + + align:start position:0% +and we have to distinguish n's from each + + + align:start position:0% +and we have to distinguish n's from each +other oh lots of questions yes + + align:start position:0% + + + + align:start position:0% + +oh yes + + align:start position:0% + + + + align:start position:0% + +himself + + align:start position:0% + + + + align:start position:0% + +oh oh oh the elephant is inside his + + align:start position:0% +oh oh oh the elephant is inside his + + + align:start position:0% +oh oh oh the elephant is inside his +pajamas and he is also wearing them + + align:start position:0% +pajamas and he is also wearing them + + + align:start position:0% +pajamas and he is also wearing them +yes + + align:start position:0% +yes + + + align:start position:0% +yes +um I don't know what kind of tree we + + align:start position:0% +um I don't know what kind of tree we + + + align:start position:0% +um I don't know what kind of tree we +want to build for that that's an + + align:start position:0% +want to build for that that's an + + + align:start position:0% +want to build for that that's an +interesting question actually we're + + align:start position:0% +interesting question actually we're + + + align:start position:0% +interesting question actually we're +going to develop some um + + align:start position:0% +going to develop some um + + + align:start position:0% +going to develop some um +tests in a second so all so far all I've + + align:start position:0% +tests in a second so all so far all I've + + + align:start position:0% +tests in a second so all so far all I've +done is assert this uh + + align:start position:0% +done is assert this uh + + + align:start position:0% +done is assert this uh +assert a couple of things uh that string + + align:start position:0% +assert a couple of things uh that string + + + align:start position:0% +assert a couple of things uh that string +of words + + align:start position:0% +of words + + + align:start position:0% +of words +ought to have two different structures + + align:start position:0% +ought to have two different structures + + + align:start position:0% +ought to have two different structures +yeah uh so that prepositional phrase + + align:start position:0% +yeah uh so that prepositional phrase + + + align:start position:0% +yeah uh so that prepositional phrase +ought to be able to modify either a noun + + align:start position:0% +ought to be able to modify either a noun + + + align:start position:0% +ought to be able to modify either a noun +phrase or a verb phrase and we have the + + align:start position:0% +phrase or a verb phrase and we have the + + + align:start position:0% +phrase or a verb phrase and we have the +sense that that string of words is + + align:start position:0% +sense that that string of words is + + + align:start position:0% +sense that that string of words is +ambiguous it can mean a couple different + + align:start position:0% +ambiguous it can mean a couple different + + + align:start position:0% +ambiguous it can mean a couple different +things + + align:start position:0% +things + + + align:start position:0% +things +um I haven't yet given you any reason to + + align:start position:0% +um I haven't yet given you any reason to + + + align:start position:0% +um I haven't yet given you any reason to +believe you know that these structures + + align:start position:0% +believe you know that these structures + + + align:start position:0% +believe you know that these structures +really are the structures that are + + align:start position:0% +really are the structures that are + + + align:start position:0% +really are the structures that are +associated with those meanings I'm going + + align:start position:0% +associated with those meanings I'm going + + + align:start position:0% +associated with those meanings I'm going +to try to do that in a second to + + align:start position:0% +to try to do that in a second to + + + align:start position:0% +to try to do that in a second to +motivate that claim and let's bear your + + align:start position:0% +motivate that claim and let's bear your + + + align:start position:0% +motivate that claim and let's bear your +reading in mind as I do that and we'll + + align:start position:0% +reading in mind as I do that and we'll + + + align:start position:0% +reading in mind as I do that and we'll +see how it behaves with respect to the + + align:start position:0% +see how it behaves with respect to the + + + align:start position:0% +see how it behaves with respect to the +tests that I'm going to show you this + + align:start position:0% +tests that I'm going to show you this + + + align:start position:0% +tests that I'm going to show you this +should all feel kind of familiar right + + align:start position:0% +should all feel kind of familiar right + + + align:start position:0% +should all feel kind of familiar right +so when we were doing unlockable uh we + + align:start position:0% +so when we were doing unlockable uh we + + + align:start position:0% +so when we were doing unlockable uh we +were saying yeah there's three morphemes + + align:start position:0% +were saying yeah there's three morphemes + + + align:start position:0% +were saying yeah there's three morphemes +there are two ways you can combine them + + align:start position:0% +there are two ways you can combine them + + + align:start position:0% +there are two ways you can combine them +and if we think about what these + + align:start position:0% +and if we think about what these + + + align:start position:0% +and if we think about what these +morphemes do with the things that they + + align:start position:0% +morphemes do with the things that they + + + align:start position:0% +morphemes do with the things that they +combine with uh we can sort of + + align:start position:0% +combine with uh we can sort of + + + align:start position:0% +combine with uh we can sort of +understand why the word unlockable is + + align:start position:0% +understand why the word unlockable is + + + align:start position:0% +understand why the word unlockable is +ambiguous in the way that it is we're + + align:start position:0% +ambiguous in the way that it is we're + + + align:start position:0% +ambiguous in the way that it is we're +gonna we're doing something similar here + + align:start position:0% +gonna we're doing something similar here + + + align:start position:0% +gonna we're doing something similar here +yeah so uh our rules for how things + + align:start position:0% +yeah so uh our rules for how things + + + align:start position:0% +yeah so uh our rules for how things +combine allow us to create these strings + + align:start position:0% +combine allow us to create these strings + + + align:start position:0% +combine allow us to create these strings +of words in a couple different ways and + + align:start position:0% +of words in a couple different ways and + + + align:start position:0% +of words in a couple different ways and +it's a big us wonder if our freedom of + + align:start position:0% +it's a big us wonder if our freedom of + + + align:start position:0% +it's a big us wonder if our freedom of +building a couple having a couple of + + align:start position:0% +building a couple having a couple of + + + align:start position:0% +building a couple having a couple of +different ways to build trees for this + + align:start position:0% +different ways to build trees for this + + + align:start position:0% +different ways to build trees for this +has anything to do with the fact that it + + align:start position:0% +has anything to do with the fact that it + + + align:start position:0% +has anything to do with the fact that it +seems to mean two different things + + align:start position:0% +seems to mean two different things + + + align:start position:0% +seems to mean two different things +Joseph did you have a question + + align:start position:0% +Joseph did you have a question + + + align:start position:0% +Joseph did you have a question +um so looking at + + align:start position:0% +um so looking at + + + align:start position:0% +um so looking at +when you said that because yeah + + align:start position:0% + + + + align:start position:0% + +would it also be appropriate + + align:start position:0% +would it also be appropriate + + + align:start position:0% +would it also be appropriate +so pajamas down all the way on the right + + align:start position:0% +so pajamas down all the way on the right + + + align:start position:0% +so pajamas down all the way on the right +part of a noun phrase and that's part of + + align:start position:0% +part of a noun phrase and that's part of + + + align:start position:0% +part of a noun phrase and that's part of +a prepositional phrase so that kind of + + align:start position:0% + + + + align:start position:0% + +that's yes that would that would work + + align:start position:0% +that's yes that would that would work + + + align:start position:0% +that's yes that would that would work +fine too your your your version of this + + align:start position:0% +fine too your your your version of this + + + align:start position:0% +fine too your your your version of this +raises the question of whether we'll + + align:start position:0% +raises the question of whether we'll + + + align:start position:0% +raises the question of whether we'll +ever find a noun phrase that has uh that + + align:start position:0% +ever find a noun phrase that has uh that + + + align:start position:0% +ever find a noun phrase that has uh that +is merged together with something else + + align:start position:0% +is merged together with something else + + + align:start position:0% +is merged together with something else +that also has the label in + + align:start position:0% +that also has the label in + + + align:start position:0% +that also has the label in +or whether we'll ever find a verb phrase + + align:start position:0% +or whether we'll ever find a verb phrase + + + align:start position:0% +or whether we'll ever find a verb phrase +that is merged together with something + + align:start position:0% +that is merged together with something + + + align:start position:0% +that is merged together with something +else that also has the label V I don't + + align:start position:0% +else that also has the label V I don't + + + align:start position:0% +else that also has the label V I don't +know whether we'll get around to seeing + + align:start position:0% +know whether we'll get around to seeing + + + align:start position:0% +know whether we'll get around to seeing +examples like that in this class it's + + align:start position:0% +examples like that in this class it's + + + align:start position:0% +examples like that in this class it's +not clear that there are such examples + + align:start position:0% +not clear that there are such examples + + + align:start position:0% +not clear that there are such examples +and if there aren't then that's + + align:start position:0% +and if there aren't then that's + + + align:start position:0% +and if there aren't then that's +interesting you know we might we might + + align:start position:0% +interesting you know we might we might + + + align:start position:0% +interesting you know we might we might +want to make something of that so yes uh + + align:start position:0% +want to make something of that so yes uh + + + align:start position:0% +want to make something of that so yes uh +your amendment to what I said and my + + align:start position:0% +your amendment to what I said and my + + + align:start position:0% +your amendment to what I said and my +amendment to what I said are both good + + align:start position:0% +amendment to what I said are both good + + + align:start position:0% +amendment to what I said are both good +ways of talking about the answer to + + align:start position:0% +ways of talking about the answer to + + + align:start position:0% +ways of talking about the answer to +Raquel's question from earlier yeah + + align:start position:0% + + + + align:start position:0% + +yep yep + + align:start position:0% +yep yep + + + align:start position:0% +yep yep +oh no see I'm sorry I'm being very + + align:start position:0% +oh no see I'm sorry I'm being very + + + align:start position:0% +oh no see I'm sorry I'm being very +unfair to you guys I keep only showing + + align:start position:0% +unfair to you guys I keep only showing + + + align:start position:0% +unfair to you guys I keep only showing +you trees for parts of sentences so + + align:start position:0% +you trees for parts of sentences so + + + align:start position:0% +you trees for parts of sentences so +we've not we haven't gotten any further + + align:start position:0% +we've not we haven't gotten any further + + + align:start position:0% +we've not we haven't gotten any further +than the verb phrase yeah yeah so so uh + + align:start position:0% +than the verb phrase yeah yeah so so uh + + + align:start position:0% +than the verb phrase yeah yeah so so uh +I'm trying to get as much mileage out of + + align:start position:0% +I'm trying to get as much mileage out of + + + align:start position:0% +I'm trying to get as much mileage out of +the verb phrase as I can before we go on + + align:start position:0% +the verb phrase as I can before we go on + + + align:start position:0% +the verb phrase as I can before we go on +to to larger things but you're right + + align:start position:0% +to to larger things but you're right + + + align:start position:0% +to to larger things but you're right +eventually we will do sentences I + + align:start position:0% +eventually we will do sentences I + + + align:start position:0% +eventually we will do sentences I +promise yeah + + align:start position:0% +promise yeah + + + align:start position:0% +promise yeah +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +questions about this + + align:start position:0% +questions about this + + + align:start position:0% +questions about this +they're all good + + align:start position:0% +they're all good + + + align:start position:0% +they're all good +um I was saying to the Tas the other day + + align:start position:0% +um I was saying to the Tas the other day + + + align:start position:0% +um I was saying to the Tas the other day +you guys are it's it's nice being in a + + align:start position:0% +you guys are it's it's nice being in a + + + align:start position:0% +you guys are it's it's nice being in a +class full of talkative people I + + align:start position:0% +class full of talkative people I + + + align:start position:0% +class full of talkative people I +appreciate it + + align:start position:0% +appreciate it + + + align:start position:0% +appreciate it +okay so two trees and uh uh hypothesis + + align:start position:0% +okay so two trees and uh uh hypothesis + + + align:start position:0% +okay so two trees and uh uh hypothesis +that we might entertain is that the tree + + align:start position:0% +that we might entertain is that the tree + + + align:start position:0% +that we might entertain is that the tree +on the left is the one where the + + align:start position:0% +on the left is the one where the + + + align:start position:0% +on the left is the one where the +elephant is wearing the pajamas and the + + align:start position:0% +elephant is wearing the pajamas and the + + + align:start position:0% +elephant is wearing the pajamas and the +tree on the right is the one where uh + + align:start position:0% +tree on the right is the one where uh + + + align:start position:0% +tree on the right is the one where uh +the shooting involves me being in the + + align:start position:0% +the shooting involves me being in the + + + align:start position:0% +the shooting involves me being in the +pajamas yeah + + align:start position:0% +pajamas yeah + + + align:start position:0% +pajamas yeah +sort of the normal reading normal for + + align:start position:0% +sort of the normal reading normal for + + + align:start position:0% +sort of the normal reading normal for +some of us although it's been + + align:start position:0% +some of us although it's been + + + align:start position:0% +some of us although it's been +established that not all of us are + + align:start position:0% +established that not all of us are + + + align:start position:0% +established that not all of us are +normal + + align:start position:0% +normal + + + align:start position:0% +normal +um + + align:start position:0% +um + + + align:start position:0% +um +now uh + + align:start position:0% +now uh + + + align:start position:0% +now uh +remember back when I was trying to + + align:start position:0% +remember back when I was trying to + + + align:start position:0% +remember back when I was trying to +convince you that there were such things + + align:start position:0% +convince you that there were such things + + + align:start position:0% +convince you that there were such things +as constituents that syntax cared about + + align:start position:0% +as constituents that syntax cared about + + + align:start position:0% +as constituents that syntax cared about +um whether a particular string of words + + align:start position:0% +um whether a particular string of words + + + align:start position:0% +um whether a particular string of words +were all descended from a single node or + + align:start position:0% +were all descended from a single node or + + + align:start position:0% +were all descended from a single node or +not + + align:start position:0% +not + + + align:start position:0% +not +um + + align:start position:0% +um + + + align:start position:0% +um +I was showing you tests for constituent + + align:start position:0% +I was showing you tests for constituent + + + align:start position:0% +I was showing you tests for constituent +structure and uh in your recitation + + align:start position:0% +structure and uh in your recitation + + + align:start position:0% +structure and uh in your recitation +sessions you may have uh played around + + align:start position:0% +sessions you may have uh played around + + + align:start position:0% +sessions you may have uh played around +with different tests for constituent + + align:start position:0% +with different tests for constituent + + + align:start position:0% +with different tests for constituent +structure so one of the tests uh that we + + align:start position:0% +structure so one of the tests uh that we + + + align:start position:0% +structure so one of the tests uh that we +were fooling around with was + + align:start position:0% +were fooling around with was + + + align:start position:0% +were fooling around with was +what I called topicalization it's + + align:start position:0% +what I called topicalization it's + + + align:start position:0% +what I called topicalization it's +possible to sort of emphasize something + + align:start position:0% +possible to sort of emphasize something + + + align:start position:0% +possible to sort of emphasize something +by moving it to the beginning of the + + align:start position:0% +by moving it to the beginning of the + + + align:start position:0% +by moving it to the beginning of the +sentence + + align:start position:0% +sentence + + + align:start position:0% +sentence +um so you can say things like the + + align:start position:0% +um so you can say things like the + + + align:start position:0% +um so you can say things like the +elephant I shot in my pajamas + + align:start position:0% +elephant I shot in my pajamas + + + align:start position:0% +elephant I shot in my pajamas +or the elephant in my pajamas I shot + + align:start position:0% +or the elephant in my pajamas I shot + + + align:start position:0% +or the elephant in my pajamas I shot +now + + align:start position:0% +now + + + align:start position:0% +now +um let's consider the tree on the left + + align:start position:0% +um let's consider the tree on the left + + + align:start position:0% +um let's consider the tree on the left +is there the street is there a + + align:start position:0% +is there the street is there a + + + align:start position:0% +is there the street is there a +constituent in that tree + + align:start position:0% +constituent in that tree + + + align:start position:0% +constituent in that tree +an elephant + + align:start position:0% + + + + align:start position:0% + +that doesn't have anything else in it + + align:start position:0% +that doesn't have anything else in it + + + align:start position:0% +that doesn't have anything else in it +several of you are appropriately shaking + + align:start position:0% +several of you are appropriately shaking + + + align:start position:0% +several of you are appropriately shaking +your heads right there's + + align:start position:0% +your heads right there's + + + align:start position:0% +your heads right there's +there are nodes that uh there are nodes + + align:start position:0% +there are nodes that uh there are nodes + + + align:start position:0% +there are nodes that uh there are nodes +that are above the words and elephants + + align:start position:0% +that are above the words and elephants + + + align:start position:0% +that are above the words and elephants +there's a d That's above and there's an + + align:start position:0% +there's a d That's above and there's an + + + align:start position:0% +there's a d That's above and there's an +N that's above elephant and there's an + + align:start position:0% +N that's above elephant and there's an + + + align:start position:0% +N that's above elephant and there's an +NP up there + + align:start position:0% +NP up there + + + align:start position:0% +NP up there +yeah which has an elephant as part of it + + align:start position:0% +yeah which has an elephant as part of it + + + align:start position:0% +yeah which has an elephant as part of it +but it also has in my pajamas yeah so in + + align:start position:0% +but it also has in my pajamas yeah so in + + + align:start position:0% +but it also has in my pajamas yeah so in +the tree on the left there's no + + align:start position:0% +the tree on the left there's no + + + align:start position:0% +the tree on the left there's no +constituent an elephant + + align:start position:0% +constituent an elephant + + + align:start position:0% +constituent an elephant +how about in the tree on the right is + + align:start position:0% +how about in the tree on the right is + + + align:start position:0% +how about in the tree on the right is +there a constituent an elephant yeah + + align:start position:0% +there a constituent an elephant yeah + + + align:start position:0% +there a constituent an elephant yeah +there's a noun phrase like that + + align:start position:0% +there's a noun phrase like that + + + align:start position:0% +there's a noun phrase like that +so when we do the topicalization the + + align:start position:0% +so when we do the topicalization the + + + align:start position:0% +so when we do the topicalization the +elephant I shot in my pajamas + + align:start position:0% +elephant I shot in my pajamas + + + align:start position:0% +elephant I shot in my pajamas +we should only be able to do the tree on + + align:start position:0% +we should only be able to do the tree on + + + align:start position:0% +we should only be able to do the tree on +the right and not the tree on the left + + align:start position:0% +the right and not the tree on the left + + + align:start position:0% +the right and not the tree on the left +that is it should only have the meaning + + align:start position:0% +that is it should only have the meaning + + + align:start position:0% +that is it should only have the meaning +that the tree on the right has + + align:start position:0% +that the tree on the right has + + + align:start position:0% +that the tree on the right has +that I was wearing the pajamas and not + + align:start position:0% +that I was wearing the pajamas and not + + + align:start position:0% +that I was wearing the pajamas and not +the elephant + + align:start position:0% +the elephant + + + align:start position:0% +the elephant +and several of you are raising your + + align:start position:0% +and several of you are raising your + + + align:start position:0% +and several of you are raising your +hands and I'll call on you in just a + + align:start position:0% +hands and I'll call on you in just a + + + align:start position:0% +hands and I'll call on you in just a +second but before I do that do people + + align:start position:0% +second but before I do that do people + + + align:start position:0% +second but before I do that do people +have the feeling that that's true + + align:start position:0% +have the feeling that that's true + + + align:start position:0% +have the feeling that that's true +that if I say the elephant I shot in my + + align:start position:0% +that if I say the elephant I shot in my + + + align:start position:0% +that if I say the elephant I shot in my +pajamas the artwork I shot in my tuxedo + + align:start position:0% +pajamas the artwork I shot in my tuxedo + + + align:start position:0% +pajamas the artwork I shot in my tuxedo +that I'm wearing these things it's not + + align:start position:0% +that I'm wearing these things it's not + + + align:start position:0% +that I'm wearing these things it's not +my victims + + align:start position:0% +my victims + + + align:start position:0% +my victims +yeah and I think that's right you know + + align:start position:0% +yeah and I think that's right you know + + + align:start position:0% +yeah and I think that's right you know +so the the ambiguity that we have if we + + align:start position:0% +so the the ambiguity that we have if we + + + align:start position:0% +so the the ambiguity that we have if we +haven't done any topicalization uh that + + align:start position:0% +haven't done any topicalization uh that + + + align:start position:0% +haven't done any topicalization uh that +ambiguity was there because we had both + + align:start position:0% +ambiguity was there because we had both + + + align:start position:0% +ambiguity was there because we had both +of these trees and if we run a + + align:start position:0% +of these trees and if we run a + + + align:start position:0% +of these trees and if we run a +constituency test + + align:start position:0% +constituency test + + + align:start position:0% +constituency test +that collapses the ambiguity because it + + align:start position:0% +that collapses the ambiguity because it + + + align:start position:0% +that collapses the ambiguity because it +makes it so that we could only have the + + align:start position:0% +makes it so that we could only have the + + + align:start position:0% +makes it so that we could only have the +tree on the right not the tree on the + + align:start position:0% +tree on the right not the tree on the + + + align:start position:0% +tree on the right not the tree on the +left and so we can only have the meaning + + align:start position:0% +left and so we can only have the meaning + + + align:start position:0% +left and so we can only have the meaning +on the right and the meaning on the left + + align:start position:0% +on the right and the meaning on the left + + + align:start position:0% +on the right and the meaning on the left +yes sorry I got to read in just a second + + align:start position:0% +yes sorry I got to read in just a second + + + align:start position:0% +yes sorry I got to read in just a second +yeah + + align:start position:0% + + + + align:start position:0% + +Oh you mean combine an elephant first + + align:start position:0% +Oh you mean combine an elephant first + + + align:start position:0% +Oh you mean combine an elephant first +and then put in my pajamas together with + + align:start position:0% +and then put in my pajamas together with + + + align:start position:0% +and then put in my pajamas together with +that yeah + + align:start position:0% +that yeah + + + align:start position:0% +that yeah +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +um so we could do that notice that if we + + align:start position:0% +um so we could do that notice that if we + + + align:start position:0% +um so we could do that notice that if we +did that + + align:start position:0% +did that + + + align:start position:0% +did that +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +there would again be a constituent an + + align:start position:0% +there would again be a constituent an + + + align:start position:0% +there would again be a constituent an +elephant + + align:start position:0% +elephant + + + align:start position:0% +elephant +so we would lose the result that we've + + align:start position:0% +so we would lose the result that we've + + + align:start position:0% +so we would lose the result that we've +got here which is that if you front the + + align:start position:0% +got here which is that if you front the + + + align:start position:0% +got here which is that if you front the +elephant I'm sorry I should keep + + align:start position:0% +elephant I'm sorry I should keep + + + align:start position:0% +elephant I'm sorry I should keep +switching back and forth between the the + + align:start position:0% +switching back and forth between the the + + + align:start position:0% +switching back and forth between the the +and just ask you to believe me that + + align:start position:0% +and just ask you to believe me that + + + align:start position:0% +and just ask you to believe me that +they're the same as far as this is + + align:start position:0% +they're the same as far as this is + + + align:start position:0% +they're the same as far as this is +concerned + + align:start position:0% +concerned + + + align:start position:0% +concerned +um but if we if we topicalize the + + align:start position:0% +um but if we if we topicalize the + + + align:start position:0% +um but if we if we topicalize the +elephant if we move that to the + + align:start position:0% +elephant if we move that to the + + + align:start position:0% +elephant if we move that to the +beginning of the sentence that we lose + + align:start position:0% +beginning of the sentence that we lose + + + align:start position:0% +beginning of the sentence that we lose +the tree on the left so you're let me + + align:start position:0% +the tree on the left so you're let me + + + align:start position:0% +the tree on the left so you're let me +make sure I'm understanding what you're + + align:start position:0% +make sure I'm understanding what you're + + + align:start position:0% +make sure I'm understanding what you're +saying you're saying wait what about a + + align:start position:0% +saying you're saying wait what about a + + + align:start position:0% +saying you're saying wait what about a +tree that would look like this + + align:start position:0% +tree that would look like this + + + align:start position:0% +tree that would look like this +shot + + align:start position:0% +shot + + + align:start position:0% +shot +and then we've got a noun phrase + + align:start position:0% +and then we've got a noun phrase + + + align:start position:0% +and then we've got a noun phrase +um + + align:start position:0% +um + + + align:start position:0% +um +and + + align:start position:0% +and + + + align:start position:0% +and +elephant + + align:start position:0% +elephant + + + align:start position:0% +elephant +and then we've got a prepositional + + align:start position:0% +and then we've got a prepositional + + + align:start position:0% +and then we've got a prepositional +phrase here in an renowned phrase and + + align:start position:0% +phrase here in an renowned phrase and + + + align:start position:0% +phrase here in an renowned phrase and +the determiner my + + align:start position:0% +the determiner my + + + align:start position:0% +the determiner my +and noun pajamas + + align:start position:0% +and noun pajamas + + + align:start position:0% +and noun pajamas +you're imagining this tree yeah + + align:start position:0% +you're imagining this tree yeah + + + align:start position:0% +you're imagining this tree yeah +um and yes uh notice though that if we + + align:start position:0% +um and yes uh notice though that if we + + + align:start position:0% +um and yes uh notice though that if we +had that tree there would be a + + align:start position:0% +had that tree there would be a + + + align:start position:0% +had that tree there would be a +constituent here an elephant yeah + + align:start position:0% +constituent here an elephant yeah + + + align:start position:0% +constituent here an elephant yeah +um so now there are two ways we can go + + align:start position:0% +um so now there are two ways we can go + + + align:start position:0% +um so now there are two ways we can go +one would be to say aha we're learning + + align:start position:0% +one would be to say aha we're learning + + + align:start position:0% +one would be to say aha we're learning +that although a prepositional phrase can + + align:start position:0% +that although a prepositional phrase can + + + align:start position:0% +that although a prepositional phrase can +merge with with you know a projection of + + align:start position:0% +merge with with you know a projection of + + + align:start position:0% +merge with with you know a projection of +a noun something something with the + + align:start position:0% +a noun something something with the + + + align:start position:0% +a noun something something with the +label in it can't it has to merge with n + + align:start position:0% +label in it can't it has to merge with n + + + align:start position:0% +label in it can't it has to merge with n +or maybe it has to merge before you + + align:start position:0% +or maybe it has to merge before you + + + align:start position:0% +or maybe it has to merge before you +merged a d right that there are rules + + align:start position:0% +merged a d right that there are rules + + + align:start position:0% +merged a d right that there are rules +about the order in which you merge + + align:start position:0% +about the order in which you merge + + + align:start position:0% +about the order in which you merge +things we're going to get a chance to + + align:start position:0% +things we're going to get a chance to + + + align:start position:0% +things we're going to get a chance to +talk about things like that soon other + + align:start position:0% +talk about things like that soon other + + + align:start position:0% +talk about things like that soon other +places where you are so so far let's see + + align:start position:0% +places where you are so so far let's see + + + align:start position:0% +places where you are so so far let's see +we're at the stage of syntax where life + + align:start position:0% +we're at the stage of syntax where life + + + align:start position:0% +we're at the stage of syntax where life +is easy and free uh there's ambiguity + + align:start position:0% +is easy and free uh there's ambiguity + + + align:start position:0% +is easy and free uh there's ambiguity +you can create trees however you want + + align:start position:0% +you can create trees however you want + + + align:start position:0% +you can create trees however you want +you've now come up with a tree that we + + align:start position:0% +you've now come up with a tree that we + + + align:start position:0% +you've now come up with a tree that we +want to exclude somehow in order to + + align:start position:0% +want to exclude somehow in order to + + + align:start position:0% +want to exclude somehow in order to +avoid the result that that first + + align:start position:0% +avoid the result that that first + + + align:start position:0% +avoid the result that that first +sentence would have this tree as a + + align:start position:0% +sentence would have this tree as a + + + align:start position:0% +sentence would have this tree as a +possible a possible tree we want to + + align:start position:0% +possible a possible tree we want to + + + align:start position:0% +possible a possible tree we want to +avoid that so there are two kinds of + + align:start position:0% +avoid that so there are two kinds of + + + align:start position:0% +avoid that so there are two kinds of +things we could do one would be to say + + align:start position:0% +things we could do one would be to say + + + align:start position:0% +things we could do one would be to say +no you may not draw this tree right so + + align:start position:0% +no you may not draw this tree right so + + + align:start position:0% +no you may not draw this tree right so +and maybe that would be about the order + + align:start position:0% +and maybe that would be about the order + + + align:start position:0% +and maybe that would be about the order +in which you can merge D and + + align:start position:0% +in which you can merge D and + + + align:start position:0% +in which you can merge D and +prepositional phrases that would be one + + align:start position:0% +prepositional phrases that would be one + + + align:start position:0% +prepositional phrases that would be one +thing we could do another thing we could + + align:start position:0% +thing we could do another thing we could + + + align:start position:0% +thing we could do another thing we could +do would be to say uh yeah uh in order + + align:start position:0% +do would be to say uh yeah uh in order + + + align:start position:0% +do would be to say uh yeah uh in order +to be topicalized you have to be a + + align:start position:0% +to be topicalized you have to be a + + + align:start position:0% +to be topicalized you have to be a +constituent but actually there are some + + align:start position:0% +constituent but actually there are some + + + align:start position:0% +constituent but actually there are some +constituents that cannot topicalize that + + align:start position:0% +constituents that cannot topicalize that + + + align:start position:0% +constituents that cannot topicalize that +is it's not a biconditional + + align:start position:0% +is it's not a biconditional + + + align:start position:0% +is it's not a biconditional +um that would be the other kind of move + + align:start position:0% +um that would be the other kind of move + + + align:start position:0% +um that would be the other kind of move +to make yeah yeah so this has been a + + align:start position:0% +to make yeah yeah so this has been a + + + align:start position:0% +to make yeah yeah so this has been a +very long and elaborate version of yes + + align:start position:0% +very long and elaborate version of yes + + + align:start position:0% +very long and elaborate version of yes +yeah and and so you're right this is an + + align:start position:0% +yeah and and so you're right this is an + + + align:start position:0% +yeah and and so you're right this is an +imaginable tree and so we must do + + align:start position:0% +imaginable tree and so we must do + + + align:start position:0% +imaginable tree and so we must do +something so I showed you a couple of + + align:start position:0% +something so I showed you a couple of + + + align:start position:0% +something so I showed you a couple of +things that we could do does that make + + align:start position:0% +things that we could do does that make + + + align:start position:0% +things that we could do does that make +sense at all okay yeah good Katarina I + + align:start position:0% +sense at all okay yeah good Katarina I + + + align:start position:0% +sense at all okay yeah good Katarina I +was also going to bring up that you + + align:start position:0% +was also going to bring up that you + + + align:start position:0% +was also going to bring up that you +could combine an elephant before yep + + align:start position:0% +could combine an elephant before yep + + + align:start position:0% +could combine an elephant before yep +emerging to the prepositional phrase yes + + align:start position:0% +emerging to the prepositional phrase yes + + + align:start position:0% +emerging to the prepositional phrase yes +good point and so I've I've answered + + align:start position:0% +good point and so I've I've answered + + + align:start position:0% +good point and so I've I've answered +good excellent good question yes Joseph + + align:start position:0% + + + + align:start position:0% + +where we want to be yes + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +breaking off an elephant + + align:start position:0% + + + + align:start position:0% + +I don't know what the actual like + + align:start position:0% +I don't know what the actual like + + + align:start position:0% +I don't know what the actual like +topology of these trees are yeah what + + align:start position:0% +topology of these trees are yeah what + + + align:start position:0% +topology of these trees are yeah what +the rules are about yeah + + align:start position:0% + + + + align:start position:0% + +um why don't you remember that question + + align:start position:0% +um why don't you remember that question + + + align:start position:0% +um why don't you remember that question +and ask it again once we have complete + + align:start position:0% +and ask it again once we have complete + + + align:start position:0% +and ask it again once we have complete +sentences yeah so uh I mean so far the + + align:start position:0% +sentences yeah so uh I mean so far the + + + align:start position:0% +sentences yeah so uh I mean so far the +only condition on topicalization this is + + align:start position:0% +only condition on topicalization this is + + + align:start position:0% +only condition on topicalization this is +this operation that puts something at + + align:start position:0% +this operation that puts something at + + + align:start position:0% +this operation that puts something at +the beginning of the sentence that I've + + align:start position:0% +the beginning of the sentence that I've + + + align:start position:0% +the beginning of the sentence that I've +offered you is that the thing that's you + + align:start position:0% +offered you is that the thing that's you + + + align:start position:0% +offered you is that the thing that's you +topicalize has to be a constituent I + + align:start position:0% +topicalize has to be a constituent I + + + align:start position:0% +topicalize has to be a constituent I +haven't said anything else about like + + align:start position:0% +haven't said anything else about like + + + align:start position:0% +haven't said anything else about like +where like I haven't offered to draw you + + align:start position:0% +where like I haven't offered to draw you + + + align:start position:0% +where like I haven't offered to draw you +a tree for the elephant I shot in my + + align:start position:0% +a tree for the elephant I shot in my + + + align:start position:0% +a tree for the elephant I shot in my +pajamas for example eventually I will + + align:start position:0% +pajamas for example eventually I will + + + align:start position:0% +pajamas for example eventually I will +um but I'm not going to do that yet uh I + + align:start position:0% +um but I'm not going to do that yet uh I + + + align:start position:0% +um but I'm not going to do that yet uh I +may not even do it today uh partly + + align:start position:0% +may not even do it today uh partly + + + align:start position:0% +may not even do it today uh partly +because eventually we have to get I shot + + align:start position:0% +because eventually we have to get I shot + + + align:start position:0% +because eventually we have to get I shot +an elephant in my pajamas just boring + + align:start position:0% +an elephant in my pajamas just boring + + + align:start position:0% +an elephant in my pajamas just boring +example bless you uh so we'll we'll get + + align:start position:0% +example bless you uh so we'll we'll get + + + align:start position:0% +example bless you uh so we'll we'll get +that first yeah + + align:start position:0% +that first yeah + + + align:start position:0% +that first yeah +yes + + align:start position:0% + + + + align:start position:0% + +if it was you mean if we were able to + + align:start position:0% +if it was you mean if we were able to + + + align:start position:0% +if it was you mean if we were able to +draw trees like this + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +I shot an elephant + + align:start position:0% + + + + align:start position:0% + +why we had better not do this so + + align:start position:0% +why we had better not do this so + + + align:start position:0% +why we had better not do this so +um we had two people point out uh one of + + align:start position:0% +um we had two people point out uh one of + + + align:start position:0% +um we had two people point out uh one of +them actually got to point it out and + + align:start position:0% +them actually got to point it out and + + + align:start position:0% +them actually got to point it out and +then Katarina pointed out that she was + + align:start position:0% +then Katarina pointed out that she was + + + align:start position:0% +then Katarina pointed out that she was +going to point it out uh that this is a + + align:start position:0% +going to point it out uh that this is a + + + align:start position:0% +going to point it out uh that this is a +tree that you could imagine right you + + align:start position:0% +tree that you could imagine right you + + + align:start position:0% +tree that you could imagine right you +you could imagine being able to build a + + align:start position:0% +you could imagine being able to build a + + + align:start position:0% +you could imagine being able to build a +tree like this and my reaction was oh + + align:start position:0% +tree like this and my reaction was oh + + + align:start position:0% +tree like this and my reaction was oh +dear we must do something to stop that + + align:start position:0% +dear we must do something to stop that + + + align:start position:0% +dear we must do something to stop that +right so um here I'll mark this tree + + align:start position:0% +right so um here I'll mark this tree + + + align:start position:0% +right so um here I'll mark this tree +with a frowny face or something we've + + align:start position:0% +with a frowny face or something we've + + + align:start position:0% +with a frowny face or something we've +got to exclude this tree somehow + + align:start position:0% +got to exclude this tree somehow + + + align:start position:0% +got to exclude this tree somehow +yeah maybe we've got we've got to avoid + + align:start position:0% +yeah maybe we've got we've got to avoid + + + align:start position:0% +yeah maybe we've got we've got to avoid +the following problem this sure looks + + align:start position:0% +the following problem this sure looks + + + align:start position:0% +the following problem this sure looks +like a tree for a meaning where the + + align:start position:0% +like a tree for a meaning where the + + + align:start position:0% +like a tree for a meaning where the +elephant is wearing the pajamas so a + + align:start position:0% +elephant is wearing the pajamas so a + + + align:start position:0% +elephant is wearing the pajamas so a +tree that has the same meaning as the + + align:start position:0% +tree that has the same meaning as the + + + align:start position:0% +tree that has the same meaning as the +tree on the left yeah but it's also a + + align:start position:0% +tree on the left yeah but it's also a + + + align:start position:0% +tree on the left yeah but it's also a +tree in which there's a constituent an + + align:start position:0% +tree in which there's a constituent an + + + align:start position:0% +tree in which there's a constituent an +elephant and the fact that I wanted to + + align:start position:0% +elephant and the fact that I wanted to + + + align:start position:0% +elephant and the fact that I wanted to +get across to you with this slide was + + align:start position:0% +get across to you with this slide was + + + align:start position:0% +get across to you with this slide was +that if you use topicalization to make + + align:start position:0% +that if you use topicalization to make + + + align:start position:0% +that if you use topicalization to make +it to to find out I was only going to + + align:start position:0% +it to to find out I was only going to + + + align:start position:0% +it to to find out I was only going to +choose between these two trees to find + + align:start position:0% +choose between these two trees to find + + + align:start position:0% +choose between these two trees to find +out whether an elephant is a constituent + + align:start position:0% +out whether an elephant is a constituent + + + align:start position:0% +out whether an elephant is a constituent +or not uh then you you have to have the + + align:start position:0% +or not uh then you you have to have the + + + align:start position:0% +or not uh then you you have to have the +tree on the right where I'm wearing the + + align:start position:0% +tree on the right where I'm wearing the + + + align:start position:0% +tree on the right where I'm wearing the +pajamas the elephant can't be wearing my + + align:start position:0% +pajamas the elephant can't be wearing my + + + align:start position:0% +pajamas the elephant can't be wearing my +pajamas two people immediately said wait + + align:start position:0% +pajamas two people immediately said wait + + + align:start position:0% +pajamas two people immediately said wait +what about this imagine the frowny-face + + align:start position:0% +what about this imagine the frowny-face + + + align:start position:0% +what about this imagine the frowny-face +street that I don't have on the slide + + align:start position:0% +street that I don't have on the slide + + + align:start position:0% +street that I don't have on the slide +yeah so and I said there are two things + + align:start position:0% +yeah so and I said there are two things + + + align:start position:0% +yeah so and I said there are two things +we could do one would be to say no you + + align:start position:0% +we could do one would be to say no you + + + align:start position:0% +we could do one would be to say no you +may not do this uh maybe because there + + align:start position:0% +may not do this uh maybe because there + + + align:start position:0% +may not do this uh maybe because there +are rules which maybe someday we'll get + + align:start position:0% +are rules which maybe someday we'll get + + + align:start position:0% +are rules which maybe someday we'll get +to that constrain the order in which you + + align:start position:0% +to that constrain the order in which you + + + align:start position:0% +to that constrain the order in which you +can merge a prepositional phrase and a d + + align:start position:0% +can merge a prepositional phrase and a d + + + align:start position:0% +can merge a prepositional phrase and a d +with a noun right rules that will + + align:start position:0% +with a noun right rules that will + + + align:start position:0% +with a noun right rules that will +guarantee that if you're going to put a + + align:start position:0% +guarantee that if you're going to put a + + + align:start position:0% +guarantee that if you're going to put a +prepositional phrase and also a D in + + align:start position:0% +prepositional phrase and also a D in + + + align:start position:0% +prepositional phrase and also a D in +projections of a noun you better do the + + align:start position:0% +projections of a noun you better do the + + + align:start position:0% +projections of a noun you better do the +prepositional phrase first and then the + + align:start position:0% +prepositional phrase first and then the + + + align:start position:0% +prepositional phrase first and then the +D and then we get to ask well why you + + align:start position:0% +D and then we get to ask well why you + + + align:start position:0% +D and then we get to ask well why you +know like what where did that rule come + + align:start position:0% +know like what where did that rule come + + + align:start position:0% +know like what where did that rule come +from and the answer is well this is day + + align:start position:0% +from and the answer is well this is day + + + align:start position:0% +from and the answer is well this is day +two of syntax you know we'll we'll get + + align:start position:0% +two of syntax you know we'll we'll get + + + align:start position:0% +two of syntax you know we'll we'll get +there yeah did that no no it's fine the + + align:start position:0% +there yeah did that no no it's fine the + + + align:start position:0% +there yeah did that no no it's fine the +other thing we could do and here let me + + align:start position:0% +other thing we could do and here let me + + + align:start position:0% +other thing we could do and here let me +say something I said before but I'll say + + align:start position:0% +say something I said before but I'll say + + + align:start position:0% +say something I said before but I'll say +it a little more coherently possibly + + align:start position:0% +it a little more coherently possibly + + + align:start position:0% +it a little more coherently possibly +we'll see uh it would be to say you know + + align:start position:0% +we'll see uh it would be to say you know + + + align:start position:0% +we'll see uh it would be to say you know +uh + + align:start position:0% +uh + + + align:start position:0% +uh +in order to topicalize in order to be + + align:start position:0% +in order to topicalize in order to be + + + align:start position:0% +in order to topicalize in order to be +fronted you have to be a constituent but + + align:start position:0% +fronted you have to be a constituent but + + + align:start position:0% +fronted you have to be a constituent but +it's not enough to be a constituent + + align:start position:0% +it's not enough to be a constituent + + + align:start position:0% +it's not enough to be a constituent +notice the thing that you would be + + align:start position:0% +notice the thing that you would be + + + align:start position:0% +notice the thing that you would be +fronting in the tree on the right uh + + align:start position:0% +fronting in the tree on the right uh + + + align:start position:0% +fronting in the tree on the right uh +it's not just a constituent it's a noun + + align:start position:0% +it's not just a constituent it's a noun + + + align:start position:0% +it's not just a constituent it's a noun +phrase + + align:start position:0% +phrase + + + align:start position:0% +phrase +and what you would be fronting over here + + align:start position:0% +and what you would be fronting over here + + + align:start position:0% +and what you would be fronting over here +is not a noun phrase it's an n Bar + + align:start position:0% +is not a noun phrase it's an n Bar + + + align:start position:0% +is not a noun phrase it's an n Bar +so you could say ah we're learning + + align:start position:0% +so you could say ah we're learning + + + align:start position:0% +so you could say ah we're learning +something new about topicalization uh + + align:start position:0% +something new about topicalization uh + + + align:start position:0% +something new about topicalization uh +topicalization yes you must be a + + align:start position:0% +topicalization yes you must be a + + + align:start position:0% +topicalization yes you must be a +constituent but it's not enough to be a + + align:start position:0% +constituent but it's not enough to be a + + + align:start position:0% +constituent but it's not enough to be a +constituent you must actually be a + + align:start position:0% +constituent you must actually be a + + + align:start position:0% +constituent you must actually be a +phrase you cannot just be a bar right + + align:start position:0% +phrase you cannot just be a bar right + + + align:start position:0% +phrase you cannot just be a bar right +and then that would be a new and + + align:start position:0% +and then that would be a new and + + + align:start position:0% +and then that would be a new and +exciting thing to learn we have to find + + align:start position:0% +exciting thing to learn we have to find + + + align:start position:0% +exciting thing to learn we have to find +out which of these ways of dealing with + + align:start position:0% +out which of these ways of dealing with + + + align:start position:0% +out which of these ways of dealing with +this tree is the better way you had a + + align:start position:0% +this tree is the better way you had a + + + align:start position:0% +this tree is the better way you had a +question a while ago I'm sorry yes uh so + + align:start position:0% +question a while ago I'm sorry yes uh so + + + align:start position:0% +question a while ago I'm sorry yes uh so +it might be like kind of jumping + + align:start position:0% +it might be like kind of jumping + + + align:start position:0% +it might be like kind of jumping +together yeah + + align:start position:0% + + + + align:start position:0% + +uh never mind okay good yes + + align:start position:0% + + + + align:start position:0% + +um well + + align:start position:0% + + + + align:start position:0% + +what if someone wants to say that well + + align:start position:0% +what if someone wants to say that well + + + align:start position:0% +what if someone wants to say that well +so + + align:start position:0% +so + + + align:start position:0% +so +so wait wait uh leave the bugs alone for + + align:start position:0% +so wait wait uh leave the bugs alone for + + + align:start position:0% +so wait wait uh leave the bugs alone for +a second + + align:start position:0% +a second + + + align:start position:0% +a second +there we have there's enough death in + + align:start position:0% +there we have there's enough death in + + + align:start position:0% +there we have there's enough death in +this class already + + align:start position:0% +this class already + + + align:start position:0% +this class already +um whoa go back + + align:start position:0% +um whoa go back + + + align:start position:0% +um whoa go back +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +uh if somebody wants the meaning so + + align:start position:0% +uh if somebody wants the meaning so + + + align:start position:0% +uh if somebody wants the meaning so +let's let's back up here's what I was + + align:start position:0% +let's let's back up here's what I was + + + align:start position:0% +let's let's back up here's what I was +gonna do with this pair of trees I was + + align:start position:0% +gonna do with this pair of trees I was + + + align:start position:0% +gonna do with this pair of trees I was +going to say hey look uh I shot the + + align:start position:0% +going to say hey look uh I shot the + + + align:start position:0% +going to say hey look uh I shot the +elephant in my pajamas as ambiguous and + + align:start position:0% +elephant in my pajamas as ambiguous and + + + align:start position:0% +elephant in my pajamas as ambiguous and +the way that Groucho Marx took advantage + + align:start position:0% +the way that Groucho Marx took advantage + + + align:start position:0% +the way that Groucho Marx took advantage +of and the ambiguity goes away and so + + align:start position:0% +of and the ambiguity goes away and so + + + align:start position:0% +of and the ambiguity goes away and so +far we've only done the first sentence + + align:start position:0% +far we've only done the first sentence + + + align:start position:0% +far we've only done the first sentence +the elephant I shot in my pajamas that + + align:start position:0% +the elephant I shot in my pajamas that + + + align:start position:0% +the elephant I shot in my pajamas that +has to be the tree on the right the tree + + align:start position:0% +has to be the tree on the right the tree + + + align:start position:0% +has to be the tree on the right the tree +on the right is the only Tree in which + + align:start position:0% +on the right is the only Tree in which + + + align:start position:0% +on the right is the only Tree in which +that's a constituent immediately people + + align:start position:0% +that's a constituent immediately people + + + align:start position:0% +that's a constituent immediately people +began doing the frowny face tree forget + + align:start position:0% +began doing the frowny face tree forget + + + align:start position:0% +began doing the frowny face tree forget +the frowny-face tree for a second those + + align:start position:0% +the frowny-face tree for a second those + + + align:start position:0% +the frowny-face tree for a second those +are the only two trees + + align:start position:0% +are the only two trees + + + align:start position:0% +are the only two trees +um has to be the tree on the right and + + align:start position:0% +um has to be the tree on the right and + + + align:start position:0% +um has to be the tree on the right and +the elephant in my pajamas I shot + + align:start position:0% + + + + align:start position:0% + +the ambiguity also collapses + + align:start position:0% +the ambiguity also collapses + + + align:start position:0% +the ambiguity also collapses +but in the other direction + + align:start position:0% +but in the other direction + + + align:start position:0% +but in the other direction +people have that feeling so if I say the + + align:start position:0% +people have that feeling so if I say the + + + align:start position:0% +people have that feeling so if I say the +elephant in my pajamas I shot the + + align:start position:0% +elephant in my pajamas I shot the + + + align:start position:0% +elephant in my pajamas I shot the +elephant in my tuxedo I I + + align:start position:0% +elephant in my tuxedo I I + + + align:start position:0% +elephant in my tuxedo I I +offered some bananas yeah + + align:start position:0% +offered some bananas yeah + + + align:start position:0% +offered some bananas yeah +um + + align:start position:0% +um + + + align:start position:0% +um +that doesn't mean I shot an elephant + + align:start position:0% +that doesn't mean I shot an elephant + + + align:start position:0% +that doesn't mean I shot an elephant +while I was wearing my pajamas that + + align:start position:0% +while I was wearing my pajamas that + + + align:start position:0% +while I was wearing my pajamas that +second one the elephant in my pajamas I + + align:start position:0% +second one the elephant in my pajamas I + + + align:start position:0% +second one the elephant in my pajamas I +shot only means that the elephant was + + align:start position:0% +shot only means that the elephant was + + + align:start position:0% +shot only means that the elephant was +wearing the pajamas Why well if we look + + align:start position:0% +wearing the pajamas Why well if we look + + + align:start position:0% +wearing the pajamas Why well if we look +at the trees we can see why there's a + + align:start position:0% +at the trees we can see why there's a + + + align:start position:0% +at the trees we can see why there's a +noun phrase an elephant in my pajamas in + + align:start position:0% +noun phrase an elephant in my pajamas in + + + align:start position:0% +noun phrase an elephant in my pajamas in +the tree on the left and there's no + + align:start position:0% +the tree on the left and there's no + + + align:start position:0% +the tree on the left and there's no +constituent an elephant in my pajamas in + + align:start position:0% +constituent an elephant in my pajamas in + + + align:start position:0% +constituent an elephant in my pajamas in +the tree on the right so these + + align:start position:0% +the tree on the right so these + + + align:start position:0% +the tree on the right so these +constituency tests topicalization + + align:start position:0% +constituency tests topicalization + + + align:start position:0% +constituency tests topicalization +forces us to one or the other of those + + align:start position:0% +forces us to one or the other of those + + + align:start position:0% +forces us to one or the other of those +two trees and uh depending on which tree + + align:start position:0% +two trees and uh depending on which tree + + + align:start position:0% +two trees and uh depending on which tree +you're forced into you only have the + + align:start position:0% +you're forced into you only have the + + + align:start position:0% +you're forced into you only have the +reading that's associated with that tree + + align:start position:0% +reading that's associated with that tree + + + align:start position:0% +reading that's associated with that tree +so the ambiguity collapses in the way + + align:start position:0% +so the ambiguity collapses in the way + + + align:start position:0% +so the ambiguity collapses in the way +that it should right so once we nail + + align:start position:0% +that it should right so once we nail + + + align:start position:0% +that it should right so once we nail +down which tree we're looking at we also + + align:start position:0% +down which tree we're looking at we also + + + align:start position:0% +down which tree we're looking at we also +nail down which meaning we have + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +uh Katrina wanted to know what if I'm + + align:start position:0% +uh Katrina wanted to know what if I'm + + + align:start position:0% +uh Katrina wanted to know what if I'm +interested in the tree on the left the + + align:start position:0% +interested in the tree on the left the + + + align:start position:0% +interested in the tree on the left the +answer is well either don't topicalize + + align:start position:0% +answer is well either don't topicalize + + + align:start position:0% +answer is well either don't topicalize +or do the topicalization the second + + align:start position:0% +or do the topicalization the second + + + align:start position:0% +or do the topicalization the second +publicization the elephant in my pajamas + + align:start position:0% +publicization the elephant in my pajamas + + + align:start position:0% +publicization the elephant in my pajamas +I shot right those are both consistent + + align:start position:0% +I shot right those are both consistent + + + align:start position:0% +I shot right those are both consistent +consistent with the tree on the left + + align:start position:0% +consistent with the tree on the left + + + align:start position:0% +consistent with the tree on the left +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +um but you can't do the first + + align:start position:0% +um but you can't do the first + + + align:start position:0% +um but you can't do the first +topicalization + + align:start position:0% +topicalization + + + align:start position:0% +topicalization +that now + + align:start position:0% +that now + + + align:start position:0% +that now +have I already warned you about this + + align:start position:0% +have I already warned you about this + + + align:start position:0% +have I already warned you about this +there's a danger if you go further in + + align:start position:0% +there's a danger if you go further in + + + align:start position:0% +there's a danger if you go further in +linguistics that you will lose the + + align:start position:0% +linguistics that you will lose the + + + align:start position:0% +linguistics that you will lose the +ability to distinguish grammatical from + + align:start position:0% +ability to distinguish grammatical from + + + align:start position:0% +ability to distinguish grammatical from +ungrammatical sentences so your your + + align:start position:0% +ungrammatical sentences so your your + + + align:start position:0% +ungrammatical sentences so your your +feelings about sentences will all become + + align:start position:0% +feelings about sentences will all become + + + align:start position:0% +feelings about sentences will all become +this kind of grape or it's sometimes + + align:start position:0% +this kind of grape or it's sometimes + + + align:start position:0% +this kind of grape or it's sometimes +called syntactician's disease and I have + + align:start position:0% +called syntactician's disease and I have + + + align:start position:0% +called syntactician's disease and I have +been a syntactician for + + align:start position:0% +been a syntactician for + + + align:start position:0% +been a syntactician for +uh longer than you have been alive which + + align:start position:0% +uh longer than you have been alive which + + + align:start position:0% +uh longer than you have been alive which +is depressing + + align:start position:0% +is depressing + + + align:start position:0% +is depressing +um and uh so I no longer have any + + align:start position:0% +um and uh so I no longer have any + + + align:start position:0% +um and uh so I no longer have any +judgments at all about sentences but but + + align:start position:0% +judgments at all about sentences but but + + + align:start position:0% +judgments at all about sentences but but +I think this is how it works does + + align:start position:0% +I think this is how it works does + + + align:start position:0% +I think this is how it works does +anybody want to object you know when I + + align:start position:0% +anybody want to object you know when I + + + align:start position:0% +anybody want to object you know when I +say these topicalizations only have one + + align:start position:0% +say these topicalizations only have one + + + align:start position:0% +say these topicalizations only have one +meaning and not the other + + align:start position:0% + + + + align:start position:0% + +to the to the tree on the left + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +I was with you right up until I thought + + align:start position:0% +I was with you right up until I thought + + + align:start position:0% +I was with you right up until I thought +I was with you right up until the end + + align:start position:0% +I was with you right up until the end + + + align:start position:0% +I was with you right up until the end +there + + align:start position:0% +there + + + align:start position:0% +there +um + + align:start position:0% +um + + + align:start position:0% +um +the sentence I shot the I shot an + + align:start position:0% +the sentence I shot the I shot an + + + align:start position:0% +the sentence I shot the I shot an +elephant in my pajamas + + align:start position:0% +elephant in my pajamas + + + align:start position:0% +elephant in my pajamas +the verb phrase + + align:start position:0% +the verb phrase + + + align:start position:0% +the verb phrase +can have either of these structures is + + align:start position:0% +can have either of these structures is + + + align:start position:0% +can have either of these structures is +that yeah + + align:start position:0% + + + + align:start position:0% + +I see and so you can only do that with + + align:start position:0% +I see and so you can only do that with + + + align:start position:0% +I see and so you can only do that with +the tree on the right because in my + + align:start position:0% +the tree on the right because in my + + + align:start position:0% +the tree on the right because in my +pajamas got merged together with a + + align:start position:0% +pajamas got merged together with a + + + align:start position:0% +pajamas got merged together with a +projection of the verb shot yeah whereas + + align:start position:0% +projection of the verb shot yeah whereas + + + align:start position:0% +projection of the verb shot yeah whereas +in the second one the elephant in my + + align:start position:0% +in the second one the elephant in my + + + align:start position:0% +in the second one the elephant in my +pajamas I shot + + align:start position:0% + + + + align:start position:0% + +what's wrong with that having either of + + align:start position:0% +what's wrong with that having either of + + + align:start position:0% +what's wrong with that having either of +these trees + + align:start position:0% + + + + align:start position:0% + +uh uh uh I see I see yes I think I could + + align:start position:0% +uh uh uh I see I see yes I think I could + + + align:start position:0% +uh uh uh I see I see yes I think I could +be wrong but I think what you are saying + + align:start position:0% +be wrong but I think what you are saying + + + align:start position:0% +be wrong but I think what you are saying +is another way of what I am saying I + + align:start position:0% +is another way of what I am saying I + + + align:start position:0% +is another way of what I am saying I +think we're saying the same thing in + + align:start position:0% +think we're saying the same thing in + + + align:start position:0% +think we're saying the same thing in +different ways so I am talking about + + align:start position:0% +different ways so I am talking about + + + align:start position:0% +different ways so I am talking about +these trees as though they are objects + + align:start position:0% +these trees as though they are objects + + + align:start position:0% +these trees as though they are objects +that you can grab nodes in them and move + + align:start position:0% +that you can grab nodes in them and move + + + align:start position:0% +that you can grab nodes in them and move +them around you were talking about these + + align:start position:0% +them around you were talking about these + + + align:start position:0% +them around you were talking about these +trees as if they are sequences of events + + align:start position:0% +trees as if they are sequences of events + + + align:start position:0% +trees as if they are sequences of events +there which is the way I encouraged you + + align:start position:0% +there which is the way I encouraged you + + + align:start position:0% +there which is the way I encouraged you +to talk about trees earlier on there + + align:start position:0% +to talk about trees earlier on there + + + align:start position:0% +to talk about trees earlier on there +there are records of the order in which + + align:start position:0% +there are records of the order in which + + + align:start position:0% +there are records of the order in which +you put two things together right and + + align:start position:0% +you put two things together right and + + + align:start position:0% +you put two things together right and +you're saying yeah if you put + + align:start position:0% +you're saying yeah if you put + + + align:start position:0% +you're saying yeah if you put +in my pajamas together with shot then + + align:start position:0% +in my pajamas together with shot then + + + align:start position:0% +in my pajamas together with shot then +you can do the first sentence and if you + + align:start position:0% +you can do the first sentence and if you + + + align:start position:0% +you can do the first sentence and if you +put in my pajamas together with the + + align:start position:0% +put in my pajamas together with the + + + align:start position:0% +put in my pajamas together with the +elephant then you can do the second + + align:start position:0% +elephant then you can do the second + + + align:start position:0% +elephant then you can do the second +sentence right that is + + align:start position:0% +sentence right that is + + + align:start position:0% +sentence right that is +which kinds of things you can topicalize + + align:start position:0% +which kinds of things you can topicalize + + + align:start position:0% +which kinds of things you can topicalize +cares about which order you put things + + align:start position:0% +cares about which order you put things + + + align:start position:0% +cares about which order you put things +together in + + align:start position:0% +together in + + + align:start position:0% +together in +and I think we are saying similar things + + align:start position:0% +and I think we are saying similar things + + + align:start position:0% +and I think we are saying similar things +I'm just saying it representationally if + + align:start position:0% +I'm just saying it representationally if + + + align:start position:0% +I'm just saying it representationally if +you want I'm inviting you to look at + + align:start position:0% +you want I'm inviting you to look at + + + align:start position:0% +you want I'm inviting you to look at +these trees and think about them as + + align:start position:0% +these trees and think about them as + + + align:start position:0% +these trees and think about them as +objects that you can move around and + + align:start position:0% +objects that you can move around and + + + align:start position:0% +objects that you can move around and +you're thinking in terms of the the + + align:start position:0% +you're thinking in terms of the the + + + align:start position:0% +you're thinking in terms of the the +order in which you put to put things + + align:start position:0% +order in which you put to put things + + + align:start position:0% +order in which you put to put things +together so I think you're right but + + align:start position:0% +together so I think you're right but + + + align:start position:0% +together so I think you're right but +you're right in the same way that I am + + align:start position:0% +you're right in the same way that I am + + + align:start position:0% +you're right in the same way that I am +right yeah + + align:start position:0% +right yeah + + + align:start position:0% +right yeah +this is the the kind of conclusion of + + align:start position:0% +this is the the kind of conclusion of + + + align:start position:0% +this is the the kind of conclusion of +this kind of conversation that I always + + align:start position:0% +this kind of conversation that I always + + + align:start position:0% +this kind of conversation that I always +like it's the one where everyone + + align:start position:0% +like it's the one where everyone + + + align:start position:0% +like it's the one where everyone +involved is right + + align:start position:0% +involved is right + + + align:start position:0% +involved is right +are there questions about this + + align:start position:0% +are there questions about this + + + align:start position:0% +are there questions about this +so far okay all right so elephants is + + align:start position:0% +so far okay all right so elephants is + + + align:start position:0% +so far okay all right so elephants is +this enough elephant violence possibly + + align:start position:0% +this enough elephant violence possibly + + + align:start position:0% +this enough elephant violence possibly +let's see oh no there's so much more + + align:start position:0% +let's see oh no there's so much more + + + align:start position:0% +let's see oh no there's so much more +violence I'm sorry + + align:start position:0% +violence I'm sorry + + + align:start position:0% +violence I'm sorry +um so this is just uh graphically + + align:start position:0% +um so this is just uh graphically + + + align:start position:0% +um so this is just uh graphically +illustrating what I just showed you you + + align:start position:0% +illustrating what I just showed you you + + + align:start position:0% +illustrating what I just showed you you +know or told you that uh in the first + + align:start position:0% +know or told you that uh in the first + + + align:start position:0% +know or told you that uh in the first +sentence uh there needs to be a + + align:start position:0% +sentence uh there needs to be a + + + align:start position:0% +sentence uh there needs to be a +constituent the elephant and it's yeah + + align:start position:0% +constituent the elephant and it's yeah + + + align:start position:0% +constituent the elephant and it's yeah +the blue constituent it's the one in the + + align:start position:0% +the blue constituent it's the one in the + + + align:start position:0% +the blue constituent it's the one in the +tree on the right uh and uh in the + + align:start position:0% +tree on the right uh and uh in the + + + align:start position:0% +tree on the right uh and uh in the +second sentence there needs to be a + + align:start position:0% +second sentence there needs to be a + + + align:start position:0% +second sentence there needs to be a +green constituent a constituent the + + align:start position:0% +green constituent a constituent the + + + align:start position:0% +green constituent a constituent the +elephant in my pajamas and it's the + + align:start position:0% +elephant in my pajamas and it's the + + + align:start position:0% +elephant in my pajamas and it's the +constituent in the tree on the left yep + + align:start position:0% + + + + align:start position:0% + +notice that this + + align:start position:0% +notice that this + + + align:start position:0% +notice that this +um also makes predictions about other + + align:start position:0% +um also makes predictions about other + + + align:start position:0% +um also makes predictions about other +kinds of sentences so um + + align:start position:0% +kinds of sentences so um + + + align:start position:0% +kinds of sentences so um +if you had thought + + align:start position:0% +if you had thought + + + align:start position:0% +if you had thought +you know these trees all this stuff + + align:start position:0% +you know these trees all this stuff + + + align:start position:0% +you know these trees all this stuff +about merge the order in which you merge + + align:start position:0% +about merge the order in which you merge + + + align:start position:0% +about merge the order in which you merge +things you don't really need any of this + + align:start position:0% +things you don't really need any of this + + + align:start position:0% +things you don't really need any of this +here's an imaginable thing you could + + align:start position:0% +here's an imaginable thing you could + + + align:start position:0% +here's an imaginable thing you could +think + + align:start position:0% +think + + + align:start position:0% +think +um you would need to get us to move + + align:start position:0% +um you would need to get us to move + + + align:start position:0% +um you would need to get us to move +fairly quickly through that last slide + + align:start position:0% +fairly quickly through that last slide + + + align:start position:0% +fairly quickly through that last slide +but you know forgetting about + + align:start position:0% +but you know forgetting about + + + align:start position:0% +but you know forgetting about +topicalization for a second if I told + + align:start position:0% +topicalization for a second if I told + + + align:start position:0% +topicalization for a second if I told +you hey look I shot an elephant in my + + align:start position:0% +you hey look I shot an elephant in my + + + align:start position:0% +you hey look I shot an elephant in my +pajamas it's ambiguous as to who's + + align:start position:0% +pajamas it's ambiguous as to who's + + + align:start position:0% +pajamas it's ambiguous as to who's +wearing the pajamas + + align:start position:0% +wearing the pajamas + + + align:start position:0% +wearing the pajamas +and I propose to deal with this with + + align:start position:0% +and I propose to deal with this with + + + align:start position:0% +and I propose to deal with this with +these trees you can imagine being + + align:start position:0% +these trees you can imagine being + + + align:start position:0% +these trees you can imagine being +someone who says no look in my pajamas + + align:start position:0% +someone who says no look in my pajamas + + + align:start position:0% +someone who says no look in my pajamas +it's just vague you know somebody's got + + align:start position:0% +it's just vague you know somebody's got + + + align:start position:0% +it's just vague you know somebody's got +to be wearing the pajamas and + + align:start position:0% +to be wearing the pajamas and + + + align:start position:0% +to be wearing the pajamas and +um you figure it out from Context + + align:start position:0% +um you figure it out from Context + + + align:start position:0% +um you figure it out from Context +whether it's me or the elephant and + + align:start position:0% +whether it's me or the elephant and + + + align:start position:0% +whether it's me or the elephant and +that's it there's no need for any any + + align:start position:0% +that's it there's no need for any any + + + align:start position:0% +that's it there's no need for any any +trees + + align:start position:0% +trees + + + align:start position:0% +trees +just so we're clear this is not the + + align:start position:0% +just so we're clear this is not the + + + align:start position:0% +just so we're clear this is not the +right way to think about this but it's + + align:start position:0% +right way to think about this but it's + + + align:start position:0% +right way to think about this but it's +something you could imagine + + align:start position:0% + + + + align:start position:0% + +here so the the stuff we talked about in + + align:start position:0% +here so the the stuff we talked about in + + + align:start position:0% +here so the the stuff we talked about in +the last slide is one reason not to + + align:start position:0% +the last slide is one reason not to + + + align:start position:0% +the last slide is one reason not to +think about things that way uh + + align:start position:0% +think about things that way uh + + + align:start position:0% +think about things that way uh +constituency tests seem to nail down + + align:start position:0% +constituency tests seem to nail down + + + align:start position:0% +constituency tests seem to nail down +where the pajamas are in the structure + + align:start position:0% +where the pajamas are in the structure + + + align:start position:0% +where the pajamas are in the structure +and that forces you to one reading or + + align:start position:0% +and that forces you to one reading or + + + align:start position:0% +and that forces you to one reading or +another here's another kind of sentence + + align:start position:0% +another here's another kind of sentence + + + align:start position:0% +another here's another kind of sentence +that also suggests where we also make a + + align:start position:0% +that also suggests where we also make a + + + align:start position:0% +that also suggests where we also make a +prediction which I think is correct so + + align:start position:0% +prediction which I think is correct so + + + align:start position:0% +prediction which I think is correct so +um if I say I shot the elephant in my + + align:start position:0% +um if I say I shot the elephant in my + + + align:start position:0% +um if I say I shot the elephant in my +pajamas in a tuxedo + + align:start position:0% + + + + align:start position:0% + +I think that's grammatical + + align:start position:0% +I think that's grammatical + + + align:start position:0% +I think that's grammatical +and I think it's a sentence in which + + align:start position:0% +and I think it's a sentence in which + + + align:start position:0% +and I think it's a sentence in which +somebody's wearing pajamas and + + align:start position:0% +somebody's wearing pajamas and + + + align:start position:0% +somebody's wearing pajamas and +somebody's wearing a tuxedo + + align:start position:0% +somebody's wearing a tuxedo + + + align:start position:0% +somebody's wearing a tuxedo +who's wearing the pajamas + + align:start position:0% + + + + align:start position:0% + +the elephant's wearing their pajamas and + + align:start position:0% +the elephant's wearing their pajamas and + + + align:start position:0% +the elephant's wearing their pajamas and +I am wearing the tuxedo + + align:start position:0% +I am wearing the tuxedo + + + align:start position:0% +I am wearing the tuxedo +does anybody not have that reading have + + align:start position:0% +does anybody not have that reading have + + + align:start position:0% +does anybody not have that reading have +instead the reading where uh I am + + align:start position:0% +instead the reading where uh I am + + + align:start position:0% +instead the reading where uh I am +wearing the pajamas and the elephants + + align:start position:0% +wearing the pajamas and the elephants + + + align:start position:0% +wearing the pajamas and the elephants +wearing a tuxedo + + align:start position:0% +wearing a tuxedo + + + align:start position:0% +wearing a tuxedo +please please put a cast out of your + + align:start position:0% +please please put a cast out of your + + + align:start position:0% +please please put a cast out of your +mind hold on cast out of your mind uh uh + + align:start position:0% +mind hold on cast out of your mind uh uh + + + align:start position:0% +mind hold on cast out of your mind uh uh +readings in which the pajamas are inside + + align:start position:0% +readings in which the pajamas are inside + + + align:start position:0% +readings in which the pajamas are inside +a tuxedo or something let's yeah I can + + align:start position:0% +a tuxedo or something let's yeah I can + + + align:start position:0% +a tuxedo or something let's yeah I can +see all of you thinking of Alternatives + + align:start position:0% +see all of you thinking of Alternatives + + + align:start position:0% +see all of you thinking of Alternatives +but uh just try to imagine cases where + + align:start position:0% +but uh just try to imagine cases where + + + align:start position:0% +but uh just try to imagine cases where +some one person one entity is wearing + + align:start position:0% +some one person one entity is wearing + + + align:start position:0% +some one person one entity is wearing +pajamas and another one is wearing the + + align:start position:0% +pajamas and another one is wearing the + + + align:start position:0% +pajamas and another one is wearing the +tuxedo uh if that's what's happening yes + + align:start position:0% +tuxedo uh if that's what's happening yes + + + align:start position:0% +tuxedo uh if that's what's happening yes +no no the pajamas are not the tuxedo + + align:start position:0% + + + + align:start position:0% + +MIT undergrads man so no there are two + + align:start position:0% +MIT undergrads man so no there are two + + + align:start position:0% +MIT undergrads man so no there are two +sets of clothing and two entities and I + + align:start position:0% +sets of clothing and two entities and I + + + align:start position:0% +sets of clothing and two entities and I +am also not an elephant just in case any + + align:start position:0% +am also not an elephant just in case any + + + align:start position:0% +am also not an elephant just in case any +of you were thinking of that + + align:start position:0% +of you were thinking of that + + + align:start position:0% +of you were thinking of that +um uh and the the clothes are not nested + + align:start position:0% +um uh and the the clothes are not nested + + + align:start position:0% +um uh and the the clothes are not nested +or mixed or anything like that there is + + align:start position:0% +or mixed or anything like that there is + + + align:start position:0% +or mixed or anything like that there is +a set of pajamas and there is a tuxedo + + align:start position:0% +a set of pajamas and there is a tuxedo + + + align:start position:0% +a set of pajamas and there is a tuxedo +and somebody's wearing a pajama + + align:start position:0% +and somebody's wearing a pajama + + + align:start position:0% +and somebody's wearing a pajama +somebody's wearing a tuxedo who's in + + align:start position:0% +somebody's wearing a tuxedo who's in + + + align:start position:0% +somebody's wearing a tuxedo who's in +what I just asserted the elephant is in + + align:start position:0% +what I just asserted the elephant is in + + + align:start position:0% +what I just asserted the elephant is in +the pajamas and I'm in the tuxedo + + align:start position:0% +the pajamas and I'm in the tuxedo + + + align:start position:0% +the pajamas and I'm in the tuxedo +can't be the other way around + + align:start position:0% + + + + align:start position:0% + +and we can kind of see why if I was + + align:start position:0% +and we can kind of see why if I was + + + align:start position:0% +and we can kind of see why if I was +smart enough we'll see if I was smart + + align:start position:0% +smart enough we'll see if I was smart + + + align:start position:0% +smart enough we'll see if I was smart +enough to draw a tree in the next slide + + align:start position:0% +enough to draw a tree in the next slide + + + align:start position:0% +enough to draw a tree in the next slide +yes I was hot dog + + align:start position:0% +yes I was hot dog + + + align:start position:0% +yes I was hot dog +um + + align:start position:0% +um + + + align:start position:0% +um +why well because if you're going to have + + align:start position:0% +why well because if you're going to have + + + align:start position:0% +why well because if you're going to have +two prepositional phrases in my pajamas + + align:start position:0% +two prepositional phrases in my pajamas + + + align:start position:0% +two prepositional phrases in my pajamas +and in a tuxedo + + align:start position:0% +and in a tuxedo + + + align:start position:0% +and in a tuxedo +and you're gonna attach them in the ways + + align:start position:0% +and you're gonna attach them in the ways + + + align:start position:0% +and you're gonna attach them in the ways +that we've been attaching prepositional + + align:start position:0% +that we've been attaching prepositional + + + align:start position:0% +that we've been attaching prepositional +phrases before this is the only way to + + align:start position:0% +phrases before this is the only way to + + + align:start position:0% +phrases before this is the only way to +do it + + align:start position:0% +do it + + + align:start position:0% +do it +yeah to get this order unless you're + + align:start position:0% +yeah to get this order unless you're + + + align:start position:0% +yeah to get this order unless you're +gonna like cross lines or something like + + align:start position:0% +gonna like cross lines or something like + + + align:start position:0% +gonna like cross lines or something like +that this is the only way to get this uh + + align:start position:0% +that this is the only way to get this uh + + + align:start position:0% +that this is the only way to get this uh +this order of words so in my pajamas has + + align:start position:0% +this order of words so in my pajamas has + + + align:start position:0% +this order of words so in my pajamas has +to modify elephants in in The Tuxedo has + + align:start position:0% +to modify elephants in in The Tuxedo has + + + align:start position:0% +to modify elephants in in The Tuxedo has +to modify the verb phrase and that's the + + align:start position:0% +to modify the verb phrase and that's the + + + align:start position:0% +to modify the verb phrase and that's the +only reading this in fact has + + align:start position:0% +only reading this in fact has + + + align:start position:0% +only reading this in fact has +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so day two of syntax and we're already + + align:start position:0% +so day two of syntax and we're already + + + align:start position:0% +so day two of syntax and we're already +um successfully predicting facts about + + align:start position:0% +um successfully predicting facts about + + + align:start position:0% +um successfully predicting facts about +you know reasonably complicated + + align:start position:0% +you know reasonably complicated + + + align:start position:0% +you know reasonably complicated +sentences involving too much clothing on + + align:start position:0% +sentences involving too much clothing on + + + align:start position:0% +sentences involving too much clothing on +in inappropriate places + + align:start position:0% + + + + align:start position:0% + +um okay oh yeah + + align:start position:0% + + + + align:start position:0% + +um I hereby declare that it is a rule + + align:start position:0% +um I hereby declare that it is a rule + + + align:start position:0% +um I hereby declare that it is a rule +that you cannot cross lines and trees + + align:start position:0% +that you cannot cross lines and trees + + + align:start position:0% +that you cannot cross lines and trees +yes you're right we have not discussed + + align:start position:0% +yes you're right we have not discussed + + + align:start position:0% +yes you're right we have not discussed +that + + align:start position:0% +that + + + align:start position:0% +that +um back in the day I would have called + + align:start position:0% +um back in the day I would have called + + + align:start position:0% +um back in the day I would have called +this the Ghostbusters rule just because + + align:start position:0% +this the Ghostbusters rule just because + + + align:start position:0% +this the Ghostbusters rule just because +the Ghostbusters had a rule that you + + align:start position:0% +the Ghostbusters had a rule that you + + + align:start position:0% +the Ghostbusters had a rule that you +couldn't cross streams never mind + + align:start position:0% +couldn't cross streams never mind + + + align:start position:0% +couldn't cross streams never mind +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +yeah other questions + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +um now I have this vague sense that some + + align:start position:0% +um now I have this vague sense that some + + + align:start position:0% +um now I have this vague sense that some +of you would like to see what the rest + + align:start position:0% +of you would like to see what the rest + + + align:start position:0% +of you would like to see what the rest +of the sentence looks like I call it the + + align:start position:0% +of the sentence looks like I call it the + + + align:start position:0% +of the sentence looks like I call it the +hunch I don't know is when you've been + + align:start position:0% +hunch I don't know is when you've been + + + align:start position:0% +hunch I don't know is when you've been +an instructor as long as I have you you + + align:start position:0% +an instructor as long as I have you you + + + align:start position:0% +an instructor as long as I have you you +get these vague hints like the fact that + + align:start position:0% +get these vague hints like the fact that + + + align:start position:0% +get these vague hints like the fact that +like 12 of you have asked me you know + + align:start position:0% +like 12 of you have asked me you know + + + align:start position:0% +like 12 of you have asked me you know +where is the subject going where should + + align:start position:0% +where is the subject going where should + + + align:start position:0% +where is the subject going where should +I put will how do we do the rest of the + + align:start position:0% +I put will how do we do the rest of the + + + align:start position:0% +I put will how do we do the rest of the +sentence why oh why are you only showing + + align:start position:0% +sentence why oh why are you only showing + + + align:start position:0% +sentence why oh why are you only showing +us verb phrases and not entire sentences + + align:start position:0% +us verb phrases and not entire sentences + + + align:start position:0% +us verb phrases and not entire sentences +so let's do the rest of the sentence + + align:start position:0% +so let's do the rest of the sentence + + + align:start position:0% +so let's do the rest of the sentence +um to do the rest of the sentence first + + align:start position:0% +um to do the rest of the sentence first + + + align:start position:0% +um to do the rest of the sentence first +of all the girl is you know a noun + + align:start position:0% +of all the girl is you know a noun + + + align:start position:0% +of all the girl is you know a noun +phrase that's kind of boring the girl is + + align:start position:0% +phrase that's kind of boring the girl is + + + align:start position:0% +phrase that's kind of boring the girl is +like the book or the garage and for will + + align:start position:0% +like the book or the garage and for will + + + align:start position:0% +like the book or the garage and for will +we are going to invent a new uh kind of + + align:start position:0% +we are going to invent a new uh kind of + + + align:start position:0% +we are going to invent a new uh kind of +node we're going to call it t for tense + + align:start position:0% +node we're going to call it t for tense + + + align:start position:0% +node we're going to call it t for tense +um + + align:start position:0% +um + + + align:start position:0% +um +just to prepare you for disappointment + + align:start position:0% +just to prepare you for disappointment + + + align:start position:0% +just to prepare you for disappointment +there are all kinds of things that can + + align:start position:0% +there are all kinds of things that can + + + align:start position:0% +there are all kinds of things that can +go under T right you can also say the + + align:start position:0% +go under T right you can also say the + + + align:start position:0% +go under T right you can also say the +girl can find the book in the garage + + align:start position:0% +girl can find the book in the garage + + + align:start position:0% +girl can find the book in the garage +right or the girl might find the book in + + align:start position:0% +right or the girl might find the book in + + + align:start position:0% +right or the girl might find the book in +the garage I can't talk today yeah uh so + + align:start position:0% +the garage I can't talk today yeah uh so + + + align:start position:0% +the garage I can't talk today yeah uh so +there are a variety of things that can + + align:start position:0% +there are a variety of things that can + + + align:start position:0% +there are a variety of things that can +go under tea uh not all of which it's + + align:start position:0% +go under tea uh not all of which it's + + + align:start position:0% +go under tea uh not all of which it's +plausible to think of as instances of + + align:start position:0% +plausible to think of as instances of + + + align:start position:0% +plausible to think of as instances of +tense like you know might is probably + + align:start position:0% +tense like you know might is probably + + + align:start position:0% +tense like you know might is probably +not a tense uh if you look get up in a + + align:start position:0% +not a tense uh if you look get up in a + + + align:start position:0% +not a tense uh if you look get up in a +traditional grammar they're not going to + + align:start position:0% +traditional grammar they're not going to + + + align:start position:0% +traditional grammar they're not going to +call it a tents but we're going to call + + align:start position:0% +call it a tents but we're going to call + + + align:start position:0% +call it a tents but we're going to call +it intense we basically just need to + + align:start position:0% +it intense we basically just need to + + + align:start position:0% +it intense we basically just need to +name for it yeah so it's there's this + + align:start position:0% +name for it yeah so it's there's this + + + align:start position:0% +name for it yeah so it's there's this +thing yeah notice it's not a it's not a + + align:start position:0% +thing yeah notice it's not a it's not a + + + align:start position:0% +thing yeah notice it's not a it's not a +verb so uh + + align:start position:0% +verb so uh + + + align:start position:0% +verb so uh +um you can't say things like the girl + + align:start position:0% +um you can't say things like the girl + + + align:start position:0% +um you can't say things like the girl +will the book + + align:start position:0% +will the book + + + align:start position:0% +will the book +um uh it's something else and our name + + align:start position:0% +um uh it's something else and our name + + + align:start position:0% +um uh it's something else and our name +for it is going to be tense uh people + + align:start position:0% +for it is going to be tense uh people + + + align:start position:0% +for it is going to be tense uh people +have called it other things they've + + align:start position:0% +have called it other things they've + + + align:start position:0% +have called it other things they've +called it the auxiliary or whatever but + + align:start position:0% +called it the auxiliary or whatever but + + + align:start position:0% +called it the auxiliary or whatever but +tense is a kind of conventional name for + + align:start position:0% +tense is a kind of conventional name for + + + align:start position:0% +tense is a kind of conventional name for +it in the literature so I'm going to + + align:start position:0% +it in the literature so I'm going to + + + align:start position:0% +it in the literature so I'm going to +call it that + + align:start position:0% +call it that + + + align:start position:0% +call it that +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +how would you differentiate tests from + + align:start position:0% + + + + align:start position:0% + +uh well so we'll see + + align:start position:0% +uh well so we'll see + + + align:start position:0% +uh well so we'll see +quickly found the book in the garage + + align:start position:0% +quickly found the book in the garage + + + align:start position:0% +quickly found the book in the garage +yeah good good question + + align:start position:0% +yeah good good question + + + align:start position:0% +yeah good good question +um let me give you the uh let me give + + align:start position:0% +um let me give you the uh let me give + + + align:start position:0% +um let me give you the uh let me give +you an answer that I won't be able + + align:start position:0% +you an answer that I won't be able + + + align:start position:0% +you an answer that I won't be able +to uh + + align:start position:0% +to uh + + + align:start position:0% +to uh +explain soon but uh that's a very nice + + align:start position:0% +explain soon but uh that's a very nice + + + align:start position:0% +explain soon but uh that's a very nice +question so the girl will find it I'll + + align:start position:0% +question so the girl will find it I'll + + + align:start position:0% +question so the girl will find it I'll +just say that and the girl + + align:start position:0% + + + + align:start position:0% + +quickly + + align:start position:0% +quickly + + + align:start position:0% +quickly +found + + align:start position:0% +found + + + align:start position:0% +found +yeah and you want to know how what's the + + align:start position:0% +yeah and you want to know how what's the + + + align:start position:0% +yeah and you want to know how what's the +difference between these two things + + align:start position:0% +difference between these two things + + + align:start position:0% +difference between these two things +there's one difference there are a bunch + + align:start position:0% +there's one difference there are a bunch + + + align:start position:0% +there's one difference there are a bunch +of + + align:start position:0% +of + + + align:start position:0% +of +um phenomena that this gets to + + align:start position:0% +um phenomena that this gets to + + + align:start position:0% +um phenomena that this gets to +participate in that this doesn't so for + + align:start position:0% +participate in that this doesn't so for + + + align:start position:0% +participate in that this doesn't so for +example + + align:start position:0% +example + + + align:start position:0% +example +um if I want to make this into a + + align:start position:0% +um if I want to make this into a + + + align:start position:0% +um if I want to make this into a +question I can ask the question will the + + align:start position:0% +question I can ask the question will the + + + align:start position:0% +question I can ask the question will the +girl + + align:start position:0% + + + + align:start position:0% + +find it + + align:start position:0% +find it + + + align:start position:0% +find it +where I put will at the beginning of the + + align:start position:0% +where I put will at the beginning of the + + + align:start position:0% +where I put will at the beginning of the +sentence and that makes the sentence a + + align:start position:0% +sentence and that makes the sentence a + + + align:start position:0% +sentence and that makes the sentence a +question yeah you can put quickly at the + + align:start position:0% +question yeah you can put quickly at the + + + align:start position:0% +question yeah you can put quickly at the +beginning of the sentence too I guess + + align:start position:0% +beginning of the sentence too I guess + + + align:start position:0% +beginning of the sentence too I guess +quickly the girl found it + + align:start position:0% +quickly the girl found it + + + align:start position:0% +quickly the girl found it +that's a grammatical sentence but it's + + align:start position:0% +that's a grammatical sentence but it's + + + align:start position:0% +that's a grammatical sentence but it's +not a question + + align:start position:0% +not a question + + + align:start position:0% +not a question +doesn't make it a question + + align:start position:0% +doesn't make it a question + + + align:start position:0% +doesn't make it a question +um so that gives us some reason to want + + align:start position:0% +um so that gives us some reason to want + + + align:start position:0% +um so that gives us some reason to want +these to be have different statuses I'll + + align:start position:0% +these to be have different statuses I'll + + + align:start position:0% +these to be have different statuses I'll +give you another reason to have them uh + + align:start position:0% +give you another reason to have them uh + + + align:start position:0% +give you another reason to have them uh +have different statuses if I ask you + + align:start position:0% +have different statuses if I ask you + + + align:start position:0% +have different statuses if I ask you +well is this true okay maybe I'm about + + align:start position:0% +well is this true okay maybe I'm about + + + align:start position:0% +well is this true okay maybe I'm about +to lie maybe I should I should quit + + align:start position:0% +to lie maybe I should I should quit + + + align:start position:0% +to lie maybe I should I should quit +while I'm ahead I think this is true if + + align:start position:0% +while I'm ahead I think this is true if + + + align:start position:0% +while I'm ahead I think this is true if +I ask you who's going to find the book + + align:start position:0% +I ask you who's going to find the book + + + align:start position:0% +I ask you who's going to find the book +you can answer the girl will + + align:start position:0% +you can answer the girl will + + + align:start position:0% +you can answer the girl will +but if I ask you who found the book it + + align:start position:0% +but if I ask you who found the book it + + + align:start position:0% +but if I ask you who found the book it +would be odd for you to say the girl + + align:start position:0% +would be odd for you to say the girl + + + align:start position:0% +would be odd for you to say the girl +quickly + + align:start position:0% +quickly + + + align:start position:0% +quickly +that's I think is that true did I just + + align:start position:0% +that's I think is that true did I just + + + align:start position:0% +that's I think is that true did I just +lie + + align:start position:0% +lie + + + align:start position:0% +lie +I think that's true so that's another + + align:start position:0% +I think that's true so that's another + + + align:start position:0% +I think that's true so that's another +reason to think there's some difference + + align:start position:0% +reason to think there's some difference + + + align:start position:0% +reason to think there's some difference +between will and quickly now what's the + + align:start position:0% +between will and quickly now what's the + + + align:start position:0% +between will and quickly now what's the +difference well we'll get to that yeah + + align:start position:0% +difference well we'll get to that yeah + + + align:start position:0% +difference well we'll get to that yeah +but or like how long are we going to + + align:start position:0% +but or like how long are we going to + + + align:start position:0% +but or like how long are we going to +explain these things and uh we'll get to + + align:start position:0% +explain these things and uh we'll get to + + + align:start position:0% +explain these things and uh we'll get to +that too this is just meant to convince + + align:start position:0% +that too this is just meant to convince + + + align:start position:0% +that too this is just meant to convince +you that maybe they're different things + + align:start position:0% +you that maybe they're different things + + + align:start position:0% +you that maybe they're different things +they have different properties + + align:start position:0% +they have different properties + + + align:start position:0% +they have different properties +yep okay cool + + align:start position:0% +yep okay cool + + + align:start position:0% +yep okay cool +all right so far so good now we need to + + align:start position:0% +all right so far so good now we need to + + + align:start position:0% +all right so far so good now we need to +do some more merging uh here's what + + align:start position:0% +do some more merging uh here's what + + + align:start position:0% +do some more merging uh here's what +we'll do + + align:start position:0% +we'll do + + + align:start position:0% +we'll do +we'll merge t with the verb phrase and + + align:start position:0% +we'll merge t with the verb phrase and + + + align:start position:0% +we'll merge t with the verb phrase and +then we'll merge the girl with the + + align:start position:0% +then we'll merge the girl with the + + + align:start position:0% +then we'll merge the girl with the +result so that the entire sentence will + + align:start position:0% +result so that the entire sentence will + + + align:start position:0% +result so that the entire sentence will +be a TP + + align:start position:0% +be a TP + + + align:start position:0% +be a TP +a tense phrase + + align:start position:0% +a tense phrase + + + align:start position:0% +a tense phrase +everything is a phrase there are D's + + align:start position:0% +everything is a phrase there are D's + + + align:start position:0% +everything is a phrase there are D's +there are noun phrases there are + + align:start position:0% +there are noun phrases there are + + + align:start position:0% +there are noun phrases there are +prepositional phrases there are verb + + align:start position:0% +prepositional phrases there are verb + + + align:start position:0% +prepositional phrases there are verb +phrases and now we have a new kind of + + align:start position:0% +phrases and now we have a new kind of + + + align:start position:0% +phrases and now we have a new kind of +phrase a tense phrase which is the + + align:start position:0% +phrase a tense phrase which is the + + + align:start position:0% +phrase a tense phrase which is the +result of merging tense will with a + + align:start position:0% +result of merging tense will with a + + + align:start position:0% +result of merging tense will with a +bunch of things + + align:start position:0% +bunch of things + + + align:start position:0% +bunch of things +there that's how we'll do sentences + + align:start position:0% + + + + align:start position:0% + +cool that was easy and painless + + align:start position:0% +cool that was easy and painless + + + align:start position:0% +cool that was easy and painless +uh yeah + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% +oh + + + align:start position:0% +oh +it's the name that we've got for taking + + align:start position:0% +it's the name that we've got for taking + + + align:start position:0% +it's the name that we've got for taking +constituents putting them at the + + align:start position:0% +constituents putting them at the + + + align:start position:0% +constituents putting them at the +beginning of the sentence + + align:start position:0% +beginning of the sentence + + + align:start position:0% +beginning of the sentence +um and uh it adds some kind of oomph to + + align:start position:0% +um and uh it adds some kind of oomph to + + + align:start position:0% +um and uh it adds some kind of oomph to +the thing that you put at the beginning + + align:start position:0% +the thing that you put at the beginning + + + align:start position:0% +the thing that you put at the beginning +of the sentence uh you know so if I say + + align:start position:0% +of the sentence uh you know so if I say + + + align:start position:0% +of the sentence uh you know so if I say +things like in the garage the girl will + + align:start position:0% +things like in the garage the girl will + + + align:start position:0% +things like in the garage the girl will +find the book + + align:start position:0% +find the book + + + align:start position:0% +find the book +that's a sentence of English it's not + + align:start position:0% +that's a sentence of English it's not + + + align:start position:0% +that's a sentence of English it's not +the most natural way to say it you would + + align:start position:0% +the most natural way to say it you would + + + align:start position:0% +the most natural way to say it you would +only say it if you wanted to put some + + align:start position:0% +only say it if you wanted to put some + + + align:start position:0% +only say it if you wanted to put some +kind of special emphasis on the garage + + align:start position:0% +kind of special emphasis on the garage + + + align:start position:0% +kind of special emphasis on the garage +and uh we will not ever in this class + + align:start position:0% +and uh we will not ever in this class + + + align:start position:0% +and uh we will not ever in this class +try to be more definite than that about + + align:start position:0% +try to be more definite than that about + + + align:start position:0% +try to be more definite than that about +the meaning of topicalization but it's a + + align:start position:0% +the meaning of topicalization but it's a + + + align:start position:0% +the meaning of topicalization but it's a +handy phenomenon for finding + + align:start position:0% +handy phenomenon for finding + + + align:start position:0% +handy phenomenon for finding +constituents + + align:start position:0% +constituents + + + align:start position:0% +constituents +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +every node on the tree is + + align:start position:0% +every node on the tree is + + + align:start position:0% +every node on the tree is +yeah yes yeah + + align:start position:0% +yeah yes yeah + + + align:start position:0% +yeah yes yeah +yep what is Will + + align:start position:0% + + + + align:start position:0% + +it's a t-bar + + align:start position:0% +it's a t-bar + + + align:start position:0% +it's a t-bar +well yes but we had constituency tests + + align:start position:0% +well yes but we had constituency tests + + + align:start position:0% +well yes but we had constituency tests +that we used to like tell whether + + align:start position:0% +that we used to like tell whether + + + align:start position:0% +that we used to like tell whether +something + + align:start position:0% +something + + + align:start position:0% +something +yeah yeah + + align:start position:0% + + + + align:start position:0% + +okay that's a good question + + align:start position:0% +okay that's a good question + + + align:start position:0% +okay that's a good question +uh that's a good question let's see so + + align:start position:0% +uh that's a good question let's see so + + + align:start position:0% +uh that's a good question let's see so +um let me so let's see you would like to + + align:start position:0% +um let me so let's see you would like to + + + align:start position:0% +um let me so let's see you would like to +know is this what you're asking me let's + + align:start position:0% +know is this what you're asking me let's + + + align:start position:0% +know is this what you're asking me let's +see + + align:start position:0% +see + + + align:start position:0% +see +we've got three things + + align:start position:0% + + + + align:start position:0% + +um the noun phrase + + align:start position:0% +um the noun phrase + + + align:start position:0% +um the noun phrase +the girl + + align:start position:0% + + + + align:start position:0% + +and the T will + + align:start position:0% +and the T will + + + align:start position:0% +and the T will +the verb phrase uh find the book in the + + align:start position:0% +the verb phrase uh find the book in the + + + align:start position:0% +the verb phrase uh find the book in the +garage ah here + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +we have a technical term for this + + align:start position:0% +we have a technical term for this + + + align:start position:0% +we have a technical term for this +it's called a triangle + + align:start position:0% +it's called a triangle + + + align:start position:0% +it's called a triangle +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +um it's used when you do not wish to + + align:start position:0% +um it's used when you do not wish to + + + align:start position:0% +um it's used when you do not wish to +draw the inside of a structure yeah so + + align:start position:0% +draw the inside of a structure yeah so + + + align:start position:0% +draw the inside of a structure yeah so +uh this is an abbreviation for that is + + align:start position:0% +uh this is an abbreviation for that is + + + align:start position:0% +uh this is an abbreviation for that is +that okay and so I've just used a + + align:start position:0% +that okay and so I've just used a + + + align:start position:0% +that okay and so I've just used a +triangle here so that I won't have to + + align:start position:0% +triangle here so that I won't have to + + + align:start position:0% +triangle here so that I won't have to +draw that entire verb phrase what I + + align:start position:0% +draw that entire verb phrase what I + + + align:start position:0% +draw that entire verb phrase what I +really need is like a stamp or something + + align:start position:0% +really need is like a stamp or something + + + align:start position:0% +really need is like a stamp or something +you know that I can use on the + + align:start position:0% +you know that I can use on the + + + align:start position:0% +you know that I can use on the +Blackboard that will uh create these + + align:start position:0% +Blackboard that will uh create these + + + align:start position:0% +Blackboard that will uh create these +three structures for me + + align:start position:0% +three structures for me + + + align:start position:0% +three structures for me +um we'll tell you on problem sets if we + + align:start position:0% +um we'll tell you on problem sets if we + + + align:start position:0% +um we'll tell you on problem sets if we +want you to not use triangles sometimes + + align:start position:0% +want you to not use triangles sometimes + + + align:start position:0% +want you to not use triangles sometimes +we'll ask you not to use triangles so + + align:start position:0% +we'll ask you not to use triangles so + + + align:start position:0% +we'll ask you not to use triangles so +that we can make you show us everything + + align:start position:0% +that we can make you show us everything + + + align:start position:0% +that we can make you show us everything +that you think about the insights and + + align:start position:0% +that you think about the insights and + + + align:start position:0% +that you think about the insights and +structures but for now I'll use a + + align:start position:0% +structures but for now I'll use a + + + align:start position:0% +structures but for now I'll use a +triangle uh so I just casually said hey + + align:start position:0% +triangle uh so I just casually said hey + + + align:start position:0% +triangle uh so I just casually said hey +I've got a good idea we'll merge will + + align:start position:0% +I've got a good idea we'll merge will + + + align:start position:0% +I've got a good idea we'll merge will +first with this and then we'll merge the + + align:start position:0% +first with this and then we'll merge the + + + align:start position:0% +first with this and then we'll merge the +result with that yeah if we're doing + + align:start position:0% +result with that yeah if we're doing + + + align:start position:0% +result with that yeah if we're doing +merge the way we've been doing merge + + align:start position:0% +merge the way we've been doing merge + + + align:start position:0% +merge the way we've been doing merge +there's only one other option which is + + align:start position:0% +there's only one other option which is + + + align:start position:0% +there's only one other option which is +this + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +and so you would like to know how do we + + align:start position:0% +and so you would like to know how do we + + + align:start position:0% +and so you would like to know how do we +know that it's what's on the slide how + + align:start position:0% +know that it's what's on the slide how + + + align:start position:0% +know that it's what's on the slide how +do we know that it's not what I've got + + align:start position:0% +do we know that it's not what I've got + + + align:start position:0% +do we know that it's not what I've got +here on the board + + align:start position:0% +here on the board + + + align:start position:0% +here on the board +um just so nobody gets confused + + align:start position:0% + + + + align:start position:0% + +this is this is not the right tree + + align:start position:0% +this is this is not the right tree + + + align:start position:0% +this is this is not the right tree +that's the right tree but now let me see + + align:start position:0% +that's the right tree but now let me see + + + align:start position:0% +that's the right tree but now let me see +if I can come up with anything that will + + align:start position:0% +if I can come up with anything that will + + + align:start position:0% +if I can come up with anything that will +convince you that it's the right tree + + align:start position:0% +convince you that it's the right tree + + + align:start position:0% +convince you that it's the right tree +uh first of all + + align:start position:0% +uh first of all + + + align:start position:0% +uh first of all +um + + align:start position:0% + + + + align:start position:0% + +if we tried to use topicalization which + + align:start position:0% +if we tried to use topicalization which + + + align:start position:0% +if we tried to use topicalization which +is the test that we had before + + align:start position:0% +is the test that we had before + + + align:start position:0% +is the test that we had before +um + + align:start position:0% +um + + + align:start position:0% +um +if we tried to use it in on the tree + + align:start position:0% +if we tried to use it in on the tree + + + align:start position:0% +if we tried to use it in on the tree +here and we tried to topicalize T Bar + + align:start position:0% +here and we tried to topicalize T Bar + + + align:start position:0% +here and we tried to topicalize T Bar +we'd end up with uh I said the girl + + align:start position:0% +we'd end up with uh I said the girl + + + align:start position:0% +we'd end up with uh I said the girl +would find the book in the garage and + + align:start position:0% +would find the book in the garage and + + + align:start position:0% +would find the book in the garage and +we'll find the book in the garage the + + align:start position:0% +we'll find the book in the garage the + + + align:start position:0% +we'll find the book in the garage the +girl + + align:start position:0% + + + + align:start position:0% + +now as I mentioned before my grasp of + + align:start position:0% +now as I mentioned before my grasp of + + + align:start position:0% +now as I mentioned before my grasp of +English is now a little shaky after + + align:start position:0% +English is now a little shaky after + + + align:start position:0% +English is now a little shaky after +years of abuse + + align:start position:0% +years of abuse + + + align:start position:0% +years of abuse +but I think that's not great yeah do + + align:start position:0% +but I think that's not great yeah do + + + align:start position:0% +but I think that's not great yeah do +people agree yeah + + align:start position:0% +people agree yeah + + + align:start position:0% +people agree yeah +uh so if there is a constituent t-bar + + align:start position:0% +uh so if there is a constituent t-bar + + + align:start position:0% +uh so if there is a constituent t-bar +here I tried to soften you up for this + + align:start position:0% +here I tried to soften you up for this + + + align:start position:0% +here I tried to soften you up for this +possibility earlier + + align:start position:0% +possibility earlier + + + align:start position:0% +possibility earlier +we needed to be the kind of constituent + + align:start position:0% +we needed to be the kind of constituent + + + align:start position:0% +we needed to be the kind of constituent +to which topicalization can't apply that + + align:start position:0% +to which topicalization can't apply that + + + align:start position:0% +to which topicalization can't apply that +is topicalization doesn't get to apply + + align:start position:0% +is topicalization doesn't get to apply + + + align:start position:0% +is topicalization doesn't get to apply +to everything and I think I also floated + + align:start position:0% +to everything and I think I also floated + + + align:start position:0% +to everything and I think I also floated +the possibility that it cares about + + align:start position:0% +the possibility that it cares about + + + align:start position:0% +the possibility that it cares about +whether you're looking at it at a p or a + + align:start position:0% +whether you're looking at it at a p or a + + + align:start position:0% +whether you're looking at it at a p or a +bar that you can't topicalize bars you + + align:start position:0% +bar that you can't topicalize bars you + + + align:start position:0% +bar that you can't topicalize bars you +can only topical isps + + align:start position:0% +can only topical isps + + + align:start position:0% +can only topical isps +this might be another case where we want + + align:start position:0% +this might be another case where we want + + + align:start position:0% +this might be another case where we want +to take that possibility seriously + + align:start position:0% +to take that possibility seriously + + + align:start position:0% +to take that possibility seriously +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yes it seems like uh like that the one + + align:start position:0% +yes it seems like uh like that the one + + + align:start position:0% +yes it seems like uh like that the one +on the board like + + align:start position:0% +on the board like + + + align:start position:0% +on the board like +that works better as a constituent + + align:start position:0% +that works better as a constituent + + + align:start position:0% +that works better as a constituent +because you could be like who will find + + align:start position:0% +because you could be like who will find + + + align:start position:0% +because you could be like who will find +the book in the garage + + align:start position:0% +the book in the garage + + + align:start position:0% +the book in the garage +the girl will um + + align:start position:0% + + + + align:start position:0% + +we'll find + + align:start position:0% +we'll find + + + align:start position:0% +we'll find +out can't say we'll find the book in the + + align:start position:0% +out can't say we'll find the book in the + + + align:start position:0% +out can't say we'll find the book in the +garage + + align:start position:0% +garage + + + align:start position:0% +garage +um if I am astonished by what you have + + align:start position:0% +um if I am astonished by what you have + + + align:start position:0% +um if I am astonished by what you have +just said uh if I've just you've just + + align:start position:0% +just said uh if I've just you've just + + + align:start position:0% +just said uh if I've just you've just +said the girl will find the book in the + + align:start position:0% +said the girl will find the book in the + + + align:start position:0% +said the girl will find the book in the +garage can I say we'll find the book in + + align:start position:0% +garage can I say we'll find the book in + + + align:start position:0% +garage can I say we'll find the book in +the garage + + align:start position:0% + + + + align:start position:0% + +some think yes others think no + + align:start position:0% +some think yes others think no + + + align:start position:0% +some think yes others think no +we'll have a + + align:start position:0% +we'll have a + + + align:start position:0% +we'll have a +a wrestling match outside later + + align:start position:0% +a wrestling match outside later + + + align:start position:0% +a wrestling match outside later +um + + align:start position:0% + + + + align:start position:0% + +the girl though + + align:start position:0% +the girl though + + + align:start position:0% +the girl though +the girl will no + + align:start position:0% +the girl will no + + + align:start position:0% +the girl will no +yeah yeah that's true + + align:start position:0% +yeah yeah that's true + + + align:start position:0% +yeah yeah that's true +um + + align:start position:0% +um + + + align:start position:0% +um +you guys are discovering a phenomenon + + align:start position:0% +you guys are discovering a phenomenon + + + align:start position:0% +you guys are discovering a phenomenon +called ellipsis + + align:start position:0% +called ellipsis + + + align:start position:0% +called ellipsis +um + + align:start position:0% +um + + + align:start position:0% +um +uh Ellipsis is a phenomenon whereby you + + align:start position:0% +uh Ellipsis is a phenomenon whereby you + + + align:start position:0% +uh Ellipsis is a phenomenon whereby you +can take chunks of the sentence and fail + + align:start position:0% +can take chunks of the sentence and fail + + + align:start position:0% +can take chunks of the sentence and fail +to pronounce them you can remove chunks + + align:start position:0% +to pronounce them you can remove chunks + + + align:start position:0% +to pronounce them you can remove chunks +of the sentence + + align:start position:0% +of the sentence + + + align:start position:0% +of the sentence +so if I ask you a question like who will + + align:start position:0% +so if I ask you a question like who will + + + align:start position:0% +so if I ask you a question like who will +find the book in the garage you can say + + align:start position:0% +find the book in the garage you can say + + + align:start position:0% +find the book in the garage you can say +the girl will or I can say things like + + align:start position:0% +the girl will or I can say things like + + + align:start position:0% +the girl will or I can say things like +the voyable find the book in the garage + + align:start position:0% +the voyable find the book in the garage + + + align:start position:0% +the voyable find the book in the garage +and the girl will too + + align:start position:0% +and the girl will too + + + align:start position:0% +and the girl will too +um + + align:start position:0% +um + + + align:start position:0% +um +all of these the the the way we would + + align:start position:0% +all of these the the the way we would + + + align:start position:0% +all of these the the the way we would +talk about them in terms of a tree like + + align:start position:0% +talk about them in terms of a tree like + + + align:start position:0% +talk about them in terms of a tree like +the one that's on the slide there is in + + align:start position:0% +the one that's on the slide there is in + + + align:start position:0% +the one that's on the slide there is in +terms of what's called VP ellipses + + align:start position:0% +terms of what's called VP ellipses + + + align:start position:0% +terms of what's called VP ellipses +there's this process of silencing + + align:start position:0% +there's this process of silencing + + + align:start position:0% +there's this process of silencing +constituents silencing phrases uh has + + align:start position:0% +constituents silencing phrases uh has + + + align:start position:0% +constituents silencing phrases uh has +applied to the verb phrase uh when you + + align:start position:0% +applied to the verb phrase uh when you + + + align:start position:0% +applied to the verb phrase uh when you +say things like + + align:start position:0% +say things like + + + align:start position:0% +say things like +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +who will + + align:start position:0% +who will + + + align:start position:0% +who will +and book + + align:start position:0% + + + + align:start position:0% + +the girl will + + align:start position:0% + + + + align:start position:0% + +so there's a blank here and the blank + + align:start position:0% +so there's a blank here and the blank + + + align:start position:0% +so there's a blank here and the blank +has understood as uh being the same as + + align:start position:0% +has understood as uh being the same as + + + align:start position:0% +has understood as uh being the same as +the preceding vertebrates + + align:start position:0% +the preceding vertebrates + + + align:start position:0% +the preceding vertebrates +and VP Ellipsis is a huge phenomenon + + align:start position:0% +and VP Ellipsis is a huge phenomenon + + + align:start position:0% +and VP Ellipsis is a huge phenomenon +which we will get a chance to talk about + + align:start position:0% +which we will get a chance to talk about + + + align:start position:0% +which we will get a chance to talk about +actually because it's going to be useful + + align:start position:0% +actually because it's going to be useful + + + align:start position:0% +actually because it's going to be useful +in a couple of weeks for for other + + align:start position:0% +in a couple of weeks for for other + + + align:start position:0% +in a couple of weeks for for other +phenomena + + align:start position:0% +phenomena + + + align:start position:0% +phenomena +um + + align:start position:0% +um + + + align:start position:0% +um +uh notice + + align:start position:0% +uh notice + + + align:start position:0% +uh notice +I'm trying to think if there's a way + + align:start position:0% +I'm trying to think if there's a way + + + align:start position:0% +I'm trying to think if there's a way +that I can convince you so so that + + align:start position:0% +that I can convince you so so that + + + align:start position:0% +that I can convince you so so that +that's not where you were going with + + align:start position:0% +that's not where you were going with + + + align:start position:0% +that's not where you were going with +this where you were going with it was + + align:start position:0% +this where you were going with it was + + + align:start position:0% +this where you were going with it was +hey look the girl will is a constituent + + align:start position:0% +hey look the girl will is a constituent + + + align:start position:0% +hey look the girl will is a constituent +there is a thing that we want to have be + + align:start position:0% +there is a thing that we want to have be + + + align:start position:0% +there is a thing that we want to have be +a constituent we want it to be a t-bar + + align:start position:0% +a constituent we want it to be a t-bar + + + align:start position:0% +a constituent we want it to be a t-bar +like here + + align:start position:0% +like here + + + align:start position:0% +like here +um whereas what I'm saying is no no no + + align:start position:0% +um whereas what I'm saying is no no no + + + align:start position:0% +um whereas what I'm saying is no no no +we want the structure on the slide and + + align:start position:0% +we want the structure on the slide and + + + align:start position:0% +we want the structure on the slide and +there is such a thing as VP Ellipsis + + align:start position:0% +there is such a thing as VP Ellipsis + + + align:start position:0% +there is such a thing as VP Ellipsis +that allows you to fail to pronounce uh + + align:start position:0% +that allows you to fail to pronounce uh + + + align:start position:0% +that allows you to fail to pronounce uh +verb phrases + + align:start position:0% +verb phrases + + + align:start position:0% +verb phrases +um let me see + + align:start position:0% +um let me see + + + align:start position:0% +um let me see +I can come up with a another test that + + align:start position:0% +I can come up with a another test that + + + align:start position:0% +I can come up with a another test that +will + + align:start position:0% +will + + + align:start position:0% +will +help you believe in one of these over + + align:start position:0% +help you believe in one of these over + + + align:start position:0% +help you believe in one of these over +the other + + align:start position:0% +the other + + + align:start position:0% +the other +um there are other phenomena that people + + align:start position:0% +um there are other phenomena that people + + + align:start position:0% +um there are other phenomena that people +use to diagnose constituent structure + + align:start position:0% +use to diagnose constituent structure + + + align:start position:0% +use to diagnose constituent structure +um and I'm trying to think if there are + + align:start position:0% +um and I'm trying to think if there are + + + align:start position:0% +um and I'm trying to think if there are +any that I can introduce sort of + + align:start position:0% +any that I can introduce sort of + + + align:start position:0% +any that I can introduce sort of +painlessly + + align:start position:0% +painlessly + + + align:start position:0% +painlessly +um you yeah no so I was about to + + align:start position:0% +um you yeah no so I was about to + + + align:start position:0% +um you yeah no so I was about to +introduce coordination but I think I + + align:start position:0% +introduce coordination but I think I + + + align:start position:0% +introduce coordination but I think I +won't you know what your Tas will prove + + align:start position:0% +won't you know what your Tas will prove + + + align:start position:0% +won't you know what your Tas will prove +to you that it's the tree on the left + + align:start position:0% +to you that it's the tree on the left + + + align:start position:0% +to you that it's the tree on the left +and not the tree on the right in um in + + align:start position:0% +and not the tree on the right in um in + + + align:start position:0% +and not the tree on the right in um in +the uh in the recitation section so + + align:start position:0% +the uh in the recitation section so + + + align:start position:0% +the uh in the recitation section so +definitely go to recitation session this + + align:start position:0% +definitely go to recitation session this + + + align:start position:0% +definitely go to recitation session this +week because your Tas will help you with + + align:start position:0% +week because your Tas will help you with + + + align:start position:0% +week because your Tas will help you with +this + + align:start position:0% +this + + + align:start position:0% +this +um I don't want to go too far down this + + align:start position:0% +um I don't want to go too far down this + + + align:start position:0% +um I don't want to go too far down this +path because there are uh + + align:start position:0% +path because there are uh + + + align:start position:0% +path because there are uh +if I try to show you the constituent + + align:start position:0% +if I try to show you the constituent + + + align:start position:0% +if I try to show you the constituent +tests that would help us to find that I + + align:start position:0% +tests that would help us to find that I + + + align:start position:0% +tests that would help us to find that I +think we'll be in trouble there is one + + align:start position:0% +think we'll be in trouble there is one + + + align:start position:0% +think we'll be in trouble there is one +well maybe I can do this now + + align:start position:0% +well maybe I can do this now + + + align:start position:0% +well maybe I can do this now +can I do this now + + align:start position:0% + + + + align:start position:0% + +I'm going to get in so much trouble this + + align:start position:0% +I'm going to get in so much trouble this + + + align:start position:0% +I'm going to get in so much trouble this +is not going to go well + + align:start position:0% +is not going to go well + + + align:start position:0% +is not going to go well +I'm going to regret doing this and we're + + align:start position:0% +I'm going to regret doing this and we're + + + align:start position:0% +I'm going to regret doing this and we're +almost out of class tell you what I will + + align:start position:0% +almost out of class tell you what I will + + + align:start position:0% +almost out of class tell you what I will +I will prove to you no you don't have to + + align:start position:0% +I will prove to you no you don't have to + + + align:start position:0% +I will prove to you no you don't have to +so you should go to recitation session + + align:start position:0% +so you should go to recitation session + + + align:start position:0% +so you should go to recitation session +but I will prove to you in the next + + align:start position:0% +but I will prove to you in the next + + + align:start position:0% +but I will prove to you in the next +class that uh that's the right tree and + + align:start position:0% +class that uh that's the right tree and + + + align:start position:0% +class that uh that's the right tree and +this is the wrong tree but it's going to + + align:start position:0% +this is the wrong tree but it's going to + + + align:start position:0% +this is the wrong tree but it's going to +require some setup uh and if I try to do + + align:start position:0% +require some setup uh and if I try to do + + + align:start position:0% +require some setup uh and if I try to do +the setup now we'll be in the middle of + + align:start position:0% +the setup now we'll be in the middle of + + + align:start position:0% +the setup now we'll be in the middle of +the setup at the end of class and we'll + + align:start position:0% +the setup at the end of class and we'll + + + align:start position:0% +the setup at the end of class and we'll +all go away unhappy so uh this is a + + align:start position:0% +all go away unhappy so uh this is a + + + align:start position:0% +all go away unhappy so uh this is a +really excellent question uh and you're + + align:start position:0% +really excellent question uh and you're + + + align:start position:0% +really excellent question uh and you're +right to be to be skeptical and alarmed + + align:start position:0% +right to be to be skeptical and alarmed + + + align:start position:0% +right to be to be skeptical and alarmed +uh uh but uh you know everybody write + + align:start position:0% +uh uh but uh you know everybody write + + + align:start position:0% +uh uh but uh you know everybody write +the tree that's on the board here and I + + align:start position:0% +the tree that's on the board here and I + + + align:start position:0% +the tree that's on the board here and I +will also reproduce it on the on the + + align:start position:0% +will also reproduce it on the on the + + + align:start position:0% +will also reproduce it on the on the +next uh set of slides for uh for for + + align:start position:0% +next uh set of slides for uh for for + + + align:start position:0% +next uh set of slides for uh for for +Thursday and then you will go into + + align:start position:0% +Thursday and then you will go into + + + align:start position:0% +Thursday and then you will go into +spring break understanding why I think + + align:start position:0% +spring break understanding why I think + + + align:start position:0% +spring break understanding why I think +it's that tree and not this tree but if + + align:start position:0% +it's that tree and not this tree but if + + + align:start position:0% +it's that tree and not this tree but if +I tried to show it to you now uh I'll + + align:start position:0% +I tried to show it to you now uh I'll + + + align:start position:0% +I tried to show it to you now uh I'll +just hurt all of us + + align:start position:0% +just hurt all of us + + + align:start position:0% +just hurt all of us +good questions are there other questions + + align:start position:0% +good questions are there other questions + + + align:start position:0% +good questions are there other questions +about this before I quickly move away + + align:start position:0% +about this before I quickly move away + + + align:start position:0% +about this before I quickly move away +from this issue + + align:start position:0% +from this issue + + + align:start position:0% +from this issue +um + + align:start position:0% +um + + + align:start position:0% +um +all right so I want to go back to the + + align:start position:0% +all right so I want to go back to the + + + align:start position:0% +all right so I want to go back to the +verb phrase + + align:start position:0% +verb phrase + + + align:start position:0% +verb phrase +um just as an exercise in um uh making + + align:start position:0% +um just as an exercise in um uh making + + + align:start position:0% +um just as an exercise in um uh making +sure that we all know what we're doing + + align:start position:0% +sure that we all know what we're doing + + + align:start position:0% +sure that we all know what we're doing +so we're going to do I will tickle the + + align:start position:0% +so we're going to do I will tickle the + + + align:start position:0% +so we're going to do I will tickle the +child with the feather uh ambiguous + + align:start position:0% +child with the feather uh ambiguous + + + align:start position:0% +child with the feather uh ambiguous +sentence does everybody agree + + align:start position:0% +sentence does everybody agree + + + align:start position:0% +sentence does everybody agree +so what are the things that it can mean + + align:start position:0% + + + + align:start position:0% + +can somebody paraphrase them for me + + align:start position:0% +can somebody paraphrase them for me + + + align:start position:0% +can somebody paraphrase them for me +Joseph + + align:start position:0% + + + + align:start position:0% + +you're going to go tickle the child and + + align:start position:0% +you're going to go tickle the child and + + + align:start position:0% +you're going to go tickle the child and +you have a feather in your hand and + + align:start position:0% +you have a feather in your hand and + + + align:start position:0% +you have a feather in your hand and +you're going to use it yep nicely + + align:start position:0% +you're going to use it yep nicely + + + align:start position:0% +you're going to use it yep nicely +paraphrased yeah so it can mean either + + align:start position:0% +paraphrased yeah so it can mean either + + + align:start position:0% +paraphrased yeah so it can mean either +of those things + + align:start position:0% +of those things + + + align:start position:0% +of those things +um we think that we can build this in + + align:start position:0% +um we think that we can build this in + + + align:start position:0% +um we think that we can build this in +a couple different ways yeah + + align:start position:0% +a couple different ways yeah + + + align:start position:0% +a couple different ways yeah +um so I will tickle the child we have + + align:start position:0% +um so I will tickle the child we have + + + align:start position:0% +um so I will tickle the child we have +two places to attach with the feather + + align:start position:0% +two places to attach with the feather + + + align:start position:0% +two places to attach with the feather +right + + align:start position:0% +right + + + align:start position:0% +right +yeah so two two trees for this + + align:start position:0% +yeah so two two trees for this + + + align:start position:0% +yeah so two two trees for this +going through this fast because we're + + align:start position:0% +going through this fast because we're + + + align:start position:0% +going through this fast because we're +running low on time but is this all all + + align:start position:0% +running low on time but is this all all + + + align:start position:0% +running low on time but is this all all +clear this is the same kind of tree that + + align:start position:0% +clear this is the same kind of tree that + + + align:start position:0% +clear this is the same kind of tree that +we've been drying up until now + + align:start position:0% +we've been drying up until now + + + align:start position:0% +we've been drying up until now +uh and uh constituency tests like + + align:start position:0% +uh and uh constituency tests like + + + align:start position:0% +uh and uh constituency tests like +topicalization tell us that we uh that + + align:start position:0% +topicalization tell us that we uh that + + + align:start position:0% +topicalization tell us that we uh that +we're right to associate these two + + align:start position:0% +we're right to associate these two + + + align:start position:0% +we're right to associate these two +different trees with two different + + align:start position:0% +different trees with two different + + + align:start position:0% +different trees with two different +meanings so these trees are basically + + align:start position:0% +meanings so these trees are basically + + + align:start position:0% +meanings so these trees are basically +just like the trees we did they're in + + align:start position:0% +just like the trees we did they're in + + + align:start position:0% +just like the trees we did they're in +fact they're identical to the trees that + + align:start position:0% +fact they're identical to the trees that + + + align:start position:0% +fact they're identical to the trees that +we did for uh I shot an elephant in my + + align:start position:0% +we did for uh I shot an elephant in my + + + align:start position:0% +we did for uh I shot an elephant in my +pajamas + + align:start position:0% +pajamas + + + align:start position:0% +pajamas +um the prepositional phrase that's at + + align:start position:0% +um the prepositional phrase that's at + + + align:start position:0% +um the prepositional phrase that's at +the end of the sentence can either be + + align:start position:0% +the end of the sentence can either be + + + align:start position:0% +the end of the sentence can either be +part of the noun phrase It's also at the + + align:start position:0% +part of the noun phrase It's also at the + + + align:start position:0% +part of the noun phrase It's also at the +end of the sentence or it can modify the + + align:start position:0% +end of the sentence or it can modify the + + + align:start position:0% +end of the sentence or it can modify the +verb phrase that depends on uh whether + + align:start position:0% +verb phrase that depends on uh whether + + + align:start position:0% +verb phrase that depends on uh whether +we're doing in this case whether we're + + align:start position:0% +we're doing in this case whether we're + + + align:start position:0% +we're doing in this case whether we're +doing the tickling with the feather or + + align:start position:0% +doing the tickling with the feather or + + + align:start position:0% +doing the tickling with the feather or +whether it's a child who has a feather + + align:start position:0% +whether it's a child who has a feather + + + align:start position:0% +whether it's a child who has a feather +and I'm going to tickle them some other + + align:start position:0% +and I'm going to tickle them some other + + + align:start position:0% +and I'm going to tickle them some other +way maybe with my fingers + + align:start position:0% +way maybe with my fingers + + + align:start position:0% +way maybe with my fingers +and then if we do topicalization that + + align:start position:0% +and then if we do topicalization that + + + align:start position:0% +and then if we do topicalization that +makes the meanings collapse so uh the + + align:start position:0% +makes the meanings collapse so uh the + + + align:start position:0% +makes the meanings collapse so uh the +child I will tickle with the feather + + align:start position:0% +child I will tickle with the feather + + + align:start position:0% +child I will tickle with the feather +only has the tree on the left the child + + align:start position:0% +only has the tree on the left the child + + + align:start position:0% +only has the tree on the left the child +with the feather I will tickle only has + + align:start position:0% +with the feather I will tickle only has + + + align:start position:0% +with the feather I will tickle only has +the tree on the right and it only has + + align:start position:0% +the tree on the right and it only has + + + align:start position:0% +the tree on the right and it only has +the meaning on the right so everybody + + align:start position:0% +the meaning on the right so everybody + + + align:start position:0% +the meaning on the right so everybody +see that this is sort of review of where + + align:start position:0% +see that this is sort of review of where + + + align:start position:0% +see that this is sort of review of where +we are so far uh with the constituent + + align:start position:0% +we are so far uh with the constituent + + + align:start position:0% +we are so far uh with the constituent +structures constituency tests that we + + align:start position:0% +structures constituency tests that we + + + align:start position:0% +structures constituency tests that we +have and as I said I will I will reveal + + align:start position:0% +have and as I said I will I will reveal + + + align:start position:0% +have and as I said I will I will reveal +another one to you on Thursday which + + align:start position:0% +another one to you on Thursday which + + + align:start position:0% +another one to you on Thursday which +will help me to get rid of this tree + + align:start position:0% +will help me to get rid of this tree + + + align:start position:0% +will help me to get rid of this tree +yeah + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% +oh + + + align:start position:0% +oh +I will tickle people generally the child + + align:start position:0% +I will tickle people generally the child + + + align:start position:0% +I will tickle people generally the child +with the feather I will tickle + + align:start position:0% + + + + align:start position:0% + +really + + align:start position:0% +really + + + align:start position:0% +really +maybe + + align:start position:0% +maybe + + + align:start position:0% +maybe +um + + align:start position:0% +um + + + align:start position:0% +um +if so + + align:start position:0% +if so + + + align:start position:0% +if so +I the child with the feather will tickle + + align:start position:0% +I the child with the feather will tickle + + + align:start position:0% +I the child with the feather will tickle +I think I think I think I want the child + + align:start position:0% +I think I think I think I want the child + + + align:start position:0% +I think I think I think I want the child +with the feather to be after I for for + + align:start position:0% +with the feather to be after I for for + + + align:start position:0% +with the feather to be after I for for +that I think that was secretarina's + + align:start position:0% +that I think that was secretarina's + + + align:start position:0% +that I think that was secretarina's +point + + align:start position:0% +point + + + align:start position:0% +point +I the child with the better I I the + + align:start position:0% +I the child with the better I I the + + + align:start position:0% +I the child with the better I I the +professor in this class demand cookies + + align:start position:0% +professor in this class demand cookies + + + align:start position:0% +professor in this class demand cookies +I think I think that's grammatical even + + align:start position:0% +I think I think that's grammatical even + + + align:start position:0% +I think I think that's grammatical even +plausible yeah + + align:start position:0% +plausible yeah + + + align:start position:0% +plausible yeah +um yeah cool so yeah they're good good + + align:start position:0% +um yeah cool so yeah they're good good + + + align:start position:0% +um yeah cool so yeah they're good good +point there could be other other + + align:start position:0% +point there could be other other + + + align:start position:0% +point there could be other other +structures to think about here + + align:start position:0% +structures to think about here + + + align:start position:0% +structures to think about here +um + + align:start position:0% +um + + + align:start position:0% +um +because we're almost out of time let me + + align:start position:0% +because we're almost out of time let me + + + align:start position:0% +because we're almost out of time let me +uh talk quickly through some terminology + + align:start position:0% +uh talk quickly through some terminology + + + align:start position:0% +uh talk quickly through some terminology +and then I'll let you guys go + + align:start position:0% +and then I'll let you guys go + + + align:start position:0% +and then I'll let you guys go +um first bit of terminology uh when + + align:start position:0% +um first bit of terminology uh when + + + align:start position:0% +um first bit of terminology uh when +people are talking about trees they + + align:start position:0% +people are talking about trees they + + + align:start position:0% +people are talking about trees they +often use feminine kinship terminology + + align:start position:0% +often use feminine kinship terminology + + + align:start position:0% +often use feminine kinship terminology +to talk about relationships between + + align:start position:0% +to talk about relationships between + + + align:start position:0% +to talk about relationships between +nodes in the tree + + align:start position:0% +nodes in the tree + + + align:start position:0% +nodes in the tree +so uh if I want to say something like I + + align:start position:0% +so uh if I want to say something like I + + + align:start position:0% +so uh if I want to say something like I +will tickle the child + + align:start position:0% +will tickle the child + + + align:start position:0% +will tickle the child +um + + align:start position:0% +um + + + align:start position:0% +um +uh we have pairs of nodes that were + + align:start position:0% +uh we have pairs of nodes that were + + + align:start position:0% +uh we have pairs of nodes that were +merged together to form larger objects + + align:start position:0% +merged together to form larger objects + + + align:start position:0% +merged together to form larger objects +like in this tree we merged the T will + + align:start position:0% +like in this tree we merged the T will + + + align:start position:0% +like in this tree we merged the T will +with the verb phrase tickled the child + + align:start position:0% +with the verb phrase tickled the child + + + align:start position:0% +with the verb phrase tickled the child +uh to form the t-bar that's just above + + align:start position:0% +uh to form the t-bar that's just above + + + align:start position:0% +uh to form the t-bar that's just above +them yeah + + align:start position:0% +them yeah + + + align:start position:0% +them yeah +uh what we say about those is that they + + align:start position:0% +uh what we say about those is that they + + + align:start position:0% +uh what we say about those is that they +are sisters so if you have two things + + align:start position:0% +are sisters so if you have two things + + + align:start position:0% +are sisters so if you have two things +that are that are the two things that + + align:start position:0% +that are that are the two things that + + + align:start position:0% +that are that are the two things that +were merged together to create one + + align:start position:0% +were merged together to create one + + + align:start position:0% +were merged together to create one +larger thing those two things are + + align:start position:0% +larger thing those two things are + + + align:start position:0% +larger thing those two things are +sisters + + align:start position:0% +sisters + + + align:start position:0% +sisters +uh similarly we say that VP is the + + align:start position:0% +uh similarly we say that VP is the + + + align:start position:0% +uh similarly we say that VP is the +mother of v and NP yeah and we also use + + align:start position:0% +mother of v and NP yeah and we also use + + + align:start position:0% +mother of v and NP yeah and we also use +the word daughter + + align:start position:0% +the word daughter + + + align:start position:0% +the word daughter +uh sorry yeah okay we also use the word + + align:start position:0% +uh sorry yeah okay we also use the word + + + align:start position:0% +uh sorry yeah okay we also use the word +daughter although I don't have it on the + + align:start position:0% +daughter although I don't have it on the + + + align:start position:0% +daughter although I don't have it on the +slide I should add it so you say that V + + align:start position:0% +slide I should add it so you say that V + + + align:start position:0% +slide I should add it so you say that V +is the daughter of VP that's as far as + + align:start position:0% +is the daughter of VP that's as far as + + + align:start position:0% +is the daughter of VP that's as far as +people go with kinship terms uh so you + + align:start position:0% +people go with kinship terms uh so you + + + align:start position:0% +people go with kinship terms uh so you +don't hear about you know grandmothers + + align:start position:0% +don't hear about you know grandmothers + + + align:start position:0% +don't hear about you know grandmothers +or aunts or cousins or anything like + + align:start position:0% +or aunts or cousins or anything like + + + align:start position:0% +or aunts or cousins or anything like +that but uh people use those terms to + + align:start position:0% +that but uh people use those terms to + + + align:start position:0% +that but uh people use those terms to +talk about relationships between nodes + + align:start position:0% +talk about relationships between nodes + + + align:start position:0% +talk about relationships between nodes +in the tree + + align:start position:0% +in the tree + + + align:start position:0% +in the tree +um the relationship motherhood + + align:start position:0% +um the relationship motherhood + + + align:start position:0% +um the relationship motherhood +uh is so the the relation that is + + align:start position:0% +uh is so the the relation that is + + + align:start position:0% +uh is so the the relation that is +created between tumor two nodes that are + + align:start position:0% +created between tumor two nodes that are + + + align:start position:0% +created between tumor two nodes that are +merged and the new node that you create + + align:start position:0% +merged and the new node that you create + + + align:start position:0% +merged and the new node that you create +via merge that's the relationship of + + align:start position:0% +via merge that's the relationship of + + + align:start position:0% +via merge that's the relationship of +what's called immediate domination so + + align:start position:0% +what's called immediate domination so + + + align:start position:0% +what's called immediate domination so +the verb phrase immediately dominates + + align:start position:0% +the verb phrase immediately dominates + + + align:start position:0% +the verb phrase immediately dominates +the V and the NP that's just another uh + + align:start position:0% +the V and the NP that's just another uh + + + align:start position:0% +the V and the NP that's just another uh +sort of scarier way to say that the VP + + align:start position:0% +sort of scarier way to say that the VP + + + align:start position:0% +sort of scarier way to say that the VP +is the mother of the V and the NP yeah + + align:start position:0% +is the mother of the V and the NP yeah + + + align:start position:0% +is the mother of the V and the NP yeah +the VP is the thing you created by + + align:start position:0% +the VP is the thing you created by + + + align:start position:0% +the VP is the thing you created by +merging V and NP together + + align:start position:0% +merging V and NP together + + + align:start position:0% +merging V and NP together +um and uh dominate so immediately + + align:start position:0% +um and uh dominate so immediately + + + align:start position:0% +um and uh dominate so immediately +dominate is kind of the the basic + + align:start position:0% +dominate is kind of the the basic + + + align:start position:0% +dominate is kind of the the basic +relation in trees uh it's the relation + + align:start position:0% +relation in trees uh it's the relation + + + align:start position:0% +relation in trees uh it's the relation +that's created by merge uh dominate is + + align:start position:0% +that's created by merge uh dominate is + + + align:start position:0% +that's created by merge uh dominate is +the transitive closure of immediate + + align:start position:0% +the transitive closure of immediate + + + align:start position:0% +the transitive closure of immediate +dominate so uh VP dominates everything + + align:start position:0% +dominate so uh VP dominates everything + + + align:start position:0% +dominate so uh VP dominates everything +it immediately dominates and everything + + align:start position:0% +it immediately dominates and everything + + + align:start position:0% +it immediately dominates and everything +those things immediately Dominate and + + align:start position:0% +those things immediately Dominate and + + + align:start position:0% +those things immediately Dominate and +everything goes things immediately + + align:start position:0% +everything goes things immediately + + + align:start position:0% +everything goes things immediately +dominate all the way down to the bottom + + align:start position:0% +dominate all the way down to the bottom + + + align:start position:0% +dominate all the way down to the bottom +of the tree so that verb phrase + + align:start position:0% +of the tree so that verb phrase + + + align:start position:0% +of the tree so that verb phrase +dominates the verb and the NP and also + + align:start position:0% +dominates the verb and the NP and also + + + align:start position:0% +dominates the verb and the NP and also +the D in the end the in child yeah it + + align:start position:0% +the D in the end the in child yeah it + + + align:start position:0% +the D in the end the in child yeah it +dominates the things that are below it + + align:start position:0% +dominates the things that are below it + + + align:start position:0% +dominates the things that are below it +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +were there when it was put together + + align:start position:0% +were there when it was put together + + + align:start position:0% +were there when it was put together +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh and I've been using this word + + align:start position:0% +uh and I've been using this word + + + align:start position:0% +uh and I've been using this word +constituent but now we can talk about + + align:start position:0% +constituent but now we can talk about + + + align:start position:0% +constituent but now we can talk about +constituents using this terminology + + align:start position:0% +constituents using this terminology + + + align:start position:0% +constituents using this terminology +we'll say that something is a + + align:start position:0% +we'll say that something is a + + + align:start position:0% +we'll say that something is a +constituent if all and only the words in + + align:start position:0% +constituent if all and only the words in + + + align:start position:0% +constituent if all and only the words in +that thing Alpha are dominated by a + + align:start position:0% +that thing Alpha are dominated by a + + + align:start position:0% +that thing Alpha are dominated by a +single node so there is a constituent + + align:start position:0% +single node so there is a constituent + + + align:start position:0% +single node so there is a constituent +tickled the child for example that verb + + align:start position:0% +tickled the child for example that verb + + + align:start position:0% +tickled the child for example that verb +phrase because there is a verb phrase + + align:start position:0% +phrase because there is a verb phrase + + + align:start position:0% +phrase because there is a verb phrase +that dominates just those words to quote + + align:start position:0% +that dominates just those words to quote + + + align:start position:0% +that dominates just those words to quote +the child there is no constituent will + + align:start position:0% +the child there is no constituent will + + + align:start position:0% +the child there is no constituent will +tickle in this tree because there's no + + align:start position:0% +tickle in this tree because there's no + + + align:start position:0% +tickle in this tree because there's no +node that just dominates the words will + + align:start position:0% +node that just dominates the words will + + + align:start position:0% +node that just dominates the words will +tickle + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +there okay + + align:start position:0% +there okay + + + align:start position:0% +there okay +uh let me because we are just about out + + align:start position:0% +uh let me because we are just about out + + + align:start position:0% +uh let me because we are just about out +of time but not quite and this would get + + align:start position:0% +of time but not quite and this would get + + + align:start position:0% +of time but not quite and this would get +us into something new let me get started + + align:start position:0% +us into something new let me get started + + + align:start position:0% +us into something new let me get started +on getting rid of this tree + + align:start position:0% +on getting rid of this tree + + + align:start position:0% +on getting rid of this tree +um and then we'll we'll pick it up here + + align:start position:0% +um and then we'll we'll pick it up here + + + align:start position:0% +um and then we'll we'll pick it up here +here next time let me show you some some + + align:start position:0% +here next time let me show you some some + + + align:start position:0% +here next time let me show you some some +uh some data + + align:start position:0% +uh some data + + + align:start position:0% +uh some data +um consider sentences like + + align:start position:0% +um consider sentences like + + + align:start position:0% +um consider sentences like +she like + + align:start position:0% +she like + + + align:start position:0% +she like +like Mary let's start with that one + + align:start position:0% +like Mary let's start with that one + + + align:start position:0% +like Mary let's start with that one +uh no here let's do + + align:start position:0% +uh no here let's do + + + align:start position:0% +uh no here let's do +she thinks + + align:start position:0% +she thinks + + + align:start position:0% +she thinks +I like + + align:start position:0% +I like + + + align:start position:0% +I like +Mary + + align:start position:0% +Mary + + + align:start position:0% +Mary +and for that matter she thinks + + align:start position:0% +and for that matter she thinks + + + align:start position:0% +and for that matter she thinks +I know + + align:start position:0% +I know + + + align:start position:0% +I know +very + + align:start position:0% +very + + + align:start position:0% +very +thanks a lot + + align:start position:0% +thanks a lot + + + align:start position:0% +thanks a lot +her + + align:start position:0% +her + + + align:start position:0% +her +these are two grammatical sentences in + + align:start position:0% +these are two grammatical sentences in + + + align:start position:0% +these are two grammatical sentences in +English yeah she thinks I like Mary and + + align:start position:0% +English yeah she thinks I like Mary and + + + align:start position:0% +English yeah she thinks I like Mary and +Mary thinks I like her + + align:start position:0% +Mary thinks I like her + + + align:start position:0% +Mary thinks I like her +it's okay + + align:start position:0% +it's okay + + + align:start position:0% +it's okay +um in the second sentence + + align:start position:0% +um in the second sentence + + + align:start position:0% +um in the second sentence +we've got Mary and we've also got her + + align:start position:0% +we've got Mary and we've also got her + + + align:start position:0% +we've got Mary and we've also got her +can her refer to Mary + + align:start position:0% +can her refer to Mary + + + align:start position:0% +can her refer to Mary +yeah could also be somebody else right + + align:start position:0% +yeah could also be somebody else right + + + align:start position:0% +yeah could also be somebody else right +but it could be Mary + + align:start position:0% +but it could be Mary + + + align:start position:0% +but it could be Mary +um we'll mark that by by putting a + + align:start position:0% +um we'll mark that by by putting a + + + align:start position:0% +um we'll mark that by by putting a +little subscript on Mary we'll call it + + align:start position:0% +little subscript on Mary we'll call it + + + align:start position:0% +little subscript on Mary we'll call it +subscript I and we'll put the same + + align:start position:0% +subscript I and we'll put the same + + + align:start position:0% +subscript I and we'll put the same +subscript on her so her could refer back + + align:start position:0% +subscript on her so her could refer back + + + align:start position:0% +subscript on her so her could refer back +to Mary could also refer to any other + + align:start position:0% +to Mary could also refer to any other + + + align:start position:0% +to Mary could also refer to any other +person any other female person yeah + + align:start position:0% +person any other female person yeah + + + align:start position:0% +person any other female person yeah +she thinks I like Mary can she be Mary + + align:start position:0% +she thinks I like Mary can she be Mary + + + align:start position:0% +she thinks I like Mary can she be Mary +no right so here she marry + + align:start position:0% +no right so here she marry + + + align:start position:0% +no right so here she marry +can't be the same person it would be bad + + align:start position:0% +can't be the same person it would be bad + + + align:start position:0% +can't be the same person it would be bad +for she to refer to the same person as + + align:start position:0% +for she to refer to the same person as + + + align:start position:0% +for she to refer to the same person as +Mary + + align:start position:0% +Mary + + + align:start position:0% +Mary +why is that do you think + + align:start position:0% + + + + align:start position:0% + +yep + + align:start position:0% + + + + align:start position:0% + +no no + + align:start position:0% +no no + + + align:start position:0% +no no +yeah does anybody have a simpler theory + + align:start position:0% +yeah does anybody have a simpler theory + + + align:start position:0% +yeah does anybody have a simpler theory +yes + + align:start position:0% + + + + align:start position:0% + +so good I was that's where I was hoping + + align:start position:0% +so good I was that's where I was hoping + + + align:start position:0% +so good I was that's where I was hoping +the first person would go Joseph is + + align:start position:0% +the first person would go Joseph is + + + align:start position:0% +the first person would go Joseph is +already like going uh more sophisticated + + align:start position:0% +already like going uh more sophisticated + + + align:start position:0% +already like going uh more sophisticated +uh so one Theory we could have would be + + align:start position:0% +uh so one Theory we could have would be + + + align:start position:0% +uh so one Theory we could have would be +uh you know Mary can't refer to somebody + + align:start position:0% +uh you know Mary can't refer to somebody + + + align:start position:0% +uh you know Mary can't refer to somebody +uh so she can't refer to somebody who + + align:start position:0% +uh so she can't refer to somebody who + + + align:start position:0% +uh so she can't refer to somebody who +hasn't been you know mentioned yet she + + align:start position:0% +hasn't been you know mentioned yet she + + + align:start position:0% +hasn't been you know mentioned yet she +can't refer to somebody who's later in + + align:start position:0% +can't refer to somebody who's later in + + + align:start position:0% +can't refer to somebody who's later in +the tree yeah + + align:start position:0% +the tree yeah + + + align:start position:0% +the tree yeah +um uh here her is referring to some + + align:start position:0% +um uh here her is referring to some + + + align:start position:0% +um uh here her is referring to some +somebody on there it's left yeah + + align:start position:0% +somebody on there it's left yeah + + + align:start position:0% +somebody on there it's left yeah +notice + + align:start position:0% +notice + + + align:start position:0% +notice +think about a sentence like + + align:start position:0% + + + + align:start position:0% + +everyone + + align:start position:0% + + + + align:start position:0% + +who knows her + + align:start position:0% + + + + align:start position:0% + +likes Mary + + align:start position:0% + + + + align:start position:0% + +can her refer to Mary there + + align:start position:0% +can her refer to Mary there + + + align:start position:0% +can her refer to Mary there +yeah so not to immediately dump on your + + align:start position:0% +yeah so not to immediately dump on your + + + align:start position:0% +yeah so not to immediately dump on your +hypothesis but I'm immediately dumping + + align:start position:0% +hypothesis but I'm immediately dumping + + + align:start position:0% +hypothesis but I'm immediately dumping +on your hypothesis yes so uh pronouns + + align:start position:0% +on your hypothesis yes so uh pronouns + + + align:start position:0% +on your hypothesis yes so uh pronouns +actually can refer to things that are + + align:start position:0% +actually can refer to things that are + + + align:start position:0% +actually can refer to things that are +later in the tree yeah + + align:start position:0% +later in the tree yeah + + + align:start position:0% +later in the tree yeah +um sorry for now let me say that again + + align:start position:0% +um sorry for now let me say that again + + + align:start position:0% +um sorry for now let me say that again +more coherently pronouns can refer to + + align:start position:0% +more coherently pronouns can refer to + + + align:start position:0% +more coherently pronouns can refer to +things that are later in the sentence + + align:start position:0% +things that are later in the sentence + + + align:start position:0% +things that are later in the sentence +you can tell I'm a syntactician because + + align:start position:0% +you can tell I'm a syntactician because + + + align:start position:0% +you can tell I'm a syntactician because +when I think of sentences I think of + + align:start position:0% +when I think of sentences I think of + + + align:start position:0% +when I think of sentences I think of +trees yeah + + align:start position:0% +trees yeah + + + align:start position:0% +trees yeah +yeah so the relationship that holds + + align:start position:0% +yeah so the relationship that holds + + + align:start position:0% +yeah so the relationship that holds +between she and Mary here + + align:start position:0% +between she and Mary here + + + align:start position:0% +between she and Mary here +between her and Mary here + + align:start position:0% +between her and Mary here + + + align:start position:0% +between her and Mary here +um the the thing that tells you whether + + align:start position:0% +um the the thing that tells you whether + + + align:start position:0% +um the the thing that tells you whether +a pronoun can refer to a person it can't + + align:start position:0% +a pronoun can refer to a person it can't + + + align:start position:0% +a pronoun can refer to a person it can't +just be about whether the person's name + + align:start position:0% +just be about whether the person's name + + + align:start position:0% +just be about whether the person's name +is later in the sentence it's going to + + align:start position:0% +is later in the sentence it's going to + + + align:start position:0% +is later in the sentence it's going to +turn out to be about the structure of + + align:start position:0% +turn out to be about the structure of + + + align:start position:0% +turn out to be about the structure of +the sentence so we'll develop a theory + + align:start position:0% +the sentence so we'll develop a theory + + + align:start position:0% +the sentence so we'll develop a theory +of these kinds of facts which will be + + align:start position:0% +of these kinds of facts which will be + + + align:start position:0% +of these kinds of facts which will be +another test for constituent structure + + align:start position:0% +another test for constituent structure + + + align:start position:0% +another test for constituent structure +so we'll we'll develop a theory of that + + align:start position:0% +so we'll we'll develop a theory of that + + + align:start position:0% +so we'll we'll develop a theory of that +and it will tell us that uh this tree is + + align:start position:0% +and it will tell us that uh this tree is + + + align:start position:0% +and it will tell us that uh this tree is +wrong yeah but uh I'll first finish + + align:start position:0% +wrong yeah but uh I'll first finish + + + align:start position:0% +wrong yeah but uh I'll first finish +developing that theory and then and then + + align:start position:0% +developing that theory and then and then + + + align:start position:0% +developing that theory and then and then +then we'll be able to use it as an + + align:start position:0% +then we'll be able to use it as an + + + align:start position:0% +then we'll be able to use it as an +additional test for structure yeah + + align:start position:0% +additional test for structure yeah + + + align:start position:0% +additional test for structure yeah +okay + + align:start position:0% +okay + + + align:start position:0% +okay +that's the incentive to come to class + + align:start position:0% +that's the incentive to come to class + + + align:start position:0% +that's the incentive to come to class +next time you'll get to see how that's + + align:start position:0% +next time you'll get to see how that's + + + align:start position:0% +next time you'll get to see how that's +going to work yeah + + align:start position:0% +going to work yeah + + + align:start position:0% +going to work yeah +Let's uh stop there unless people have + + align:start position:0% +Let's uh stop there unless people have + + + align:start position:0% +Let's uh stop there unless people have +any questions about this stuff + + align:start position:0% +any questions about this stuff + + + align:start position:0% +any questions about this stuff +all right good let's uh let's just pause + + align:start position:0% +all right good let's uh let's just pause + + + align:start position:0% +all right good let's uh let's just pause +it right there because if I start trying + + align:start position:0% +it right there because if I start trying + + + align:start position:0% +it right there because if I start trying +to show you this any further we'll just + + align:start position:0% +to show you this any further we'll just + + + align:start position:0% +to show you this any further we'll just +all get confused \ No newline at end of file diff --git a/-j7MoM3P_J8.txt b/-j7MoM3P_J8.txt new file mode 100644 index 0000000000000000000000000000000000000000..c854361c37e452b6d3e7051ff7fced4fbe86cb1f --- /dev/null +++ b/-j7MoM3P_J8.txt @@ -0,0 +1,1963 @@ +align:start position:0% + +random walks provide probabilistic + + align:start position:0% +random walks provide probabilistic + + + align:start position:0% +random walks provide probabilistic +models for a bunch of settings in fact + + align:start position:0% +models for a bunch of settings in fact + + + align:start position:0% +models for a bunch of settings in fact +we've seen a couple already so let's + + align:start position:0% +we've seen a couple already so let's + + + align:start position:0% +we've seen a couple already so let's +examine what they are in general so the + + align:start position:0% +examine what they are in general so the + + + align:start position:0% +examine what they are in general so the +setup for a random walk is that you have + + align:start position:0% +setup for a random walk is that you have + + + align:start position:0% +setup for a random walk is that you have +a digraph and we can also also often + + align:start position:0% +a digraph and we can also also often + + + align:start position:0% +a digraph and we can also also often +think and talk about the digraph as + + align:start position:0% +think and talk about the digraph as + + + align:start position:0% +think and talk about the digraph as +those a state mistake diagram for a + + align:start position:0% +those a state mistake diagram for a + + + align:start position:0% +those a state mistake diagram for a +machine with States so here's a three + + align:start position:0% +machine with States so here's a three + + + align:start position:0% +machine with States so here's a three +state digraph blue orange and green and + + align:start position:0% +state digraph blue orange and green and + + + align:start position:0% +state digraph blue orange and green and +the part that becomes probabilistic is + + align:start position:0% +the part that becomes probabilistic is + + + align:start position:0% +the part that becomes probabilistic is +that we think of the process of which + + align:start position:0% +that we think of the process of which + + + align:start position:0% +that we think of the process of which +edge to follow when you're at a given + + align:start position:0% +edge to follow when you're at a given + + + align:start position:0% +edge to follow when you're at a given +state is made probabilistically and the + + align:start position:0% +state is made probabilistically and the + + + align:start position:0% +state is made probabilistically and the +only rules are that we're going to + + align:start position:0% +only rules are that we're going to + + + align:start position:0% +only rules are that we're going to +assign probabilities to the edges in a + + align:start position:0% +assign probabilities to the edges in a + + + align:start position:0% +assign probabilities to the edges in a +way like this where for example what I'm + + align:start position:0% +way like this where for example what I'm + + + align:start position:0% +way like this where for example what I'm +telling you is there's a 1/3 probability + + align:start position:0% +telling you is there's a 1/3 probability + + + align:start position:0% +telling you is there's a 1/3 probability +that I'll follow the edge from o to O + + align:start position:0% +that I'll follow the edge from o to O + + + align:start position:0% +that I'll follow the edge from o to O +and a 2/3 probability that I'll follow + + align:start position:0% +and a 2/3 probability that I'll follow + + + align:start position:0% +and a 2/3 probability that I'll follow +from the the edge from o to green and + + align:start position:0% +from the the edge from o to green and + + + align:start position:0% +from the the edge from o to green and +the rule is simply that the sum of the + + align:start position:0% +the rule is simply that the sum of the + + + align:start position:0% +the rule is simply that the sum of the +probabilities on the outgoing edges has + + align:start position:0% +probabilities on the outgoing edges has + + + align:start position:0% +probabilities on the outgoing edges has +to sum to 1 so let's fill in the rest of + + align:start position:0% +to sum to 1 so let's fill in the rest of + + + align:start position:0% +to sum to 1 so let's fill in the rest of +the graph in a legal way so here we have + + align:start position:0% +the graph in a legal way so here we have + + + align:start position:0% +the graph in a legal way so here we have +B with 1/2 probability of going from B + + align:start position:0% +B with 1/2 probability of going from B + + + align:start position:0% +B with 1/2 probability of going from B +to B 1/4 from B to O and 1/4 from B to G + + align:start position:0% +to B 1/4 from B to O and 1/4 from B to G + + + align:start position:0% +to B 1/4 from B to O and 1/4 from B to G +and the Green State is certain in one + + align:start position:0% +and the Green State is certain in one + + + align:start position:0% +and the Green State is certain in one +step if you're at Green to go to blue + + align:start position:0% +step if you're at Green to go to blue + + + align:start position:0% +step if you're at Green to go to blue +next that there's only one edge out it + + align:start position:0% +next that there's only one edge out it + + + align:start position:0% +next that there's only one edge out it +has probability 1 + + align:start position:0% +has probability 1 + + + align:start position:0% +has probability 1 +now gamblers ruin it can be seen as an + + align:start position:0% +now gamblers ruin it can be seen as an + + + align:start position:0% +now gamblers ruin it can be seen as an +example of this kind of a random luck + + align:start position:0% +example of this kind of a random luck + + + align:start position:0% +example of this kind of a random luck +the states were the amount of money that + + align:start position:0% +the states were the amount of money that + + + align:start position:0% +the states were the amount of money that +you had ranging from zero when you're + + align:start position:0% +you had ranging from zero when you're + + + align:start position:0% +you had ranging from zero when you're +bankrupt to t when you've reached your + + align:start position:0% +bankrupt to t when you've reached your + + + align:start position:0% +bankrupt to t when you've reached your +target and n is the start state which is + + align:start position:0% +target and n is the start state which is + + + align:start position:0% +target and n is the start state which is +your initial stake the green areas are + + align:start position:0% +your initial stake the green areas are + + + align:start position:0% +your initial stake the green areas are +weighted with a probability of P of + + align:start position:0% +weighted with a probability of P of + + + align:start position:0% +weighted with a probability of P of +winning a bet so we have transitions + + align:start position:0% +winning a bet so we have transitions + + + align:start position:0% +winning a bet so we have transitions +from k to k plus 1 for K less than T of + + align:start position:0% +from k to k plus 1 for K less than T of + + + align:start position:0% +from k to k plus 1 for K less than T of +probably the weight probability P and + + align:start position:0% +probably the weight probability P and + + + align:start position:0% +probably the weight probability P and +likewise the red edges are weighted with + + align:start position:0% +likewise the red edges are weighted with + + + align:start position:0% +likewise the red edges are weighted with +the probability of losing a bet Q or 1 + + align:start position:0% +the probability of losing a bet Q or 1 + + + align:start position:0% +the probability of losing a bet Q or 1 +minus P so there is a digraph or a state + + align:start position:0% +minus P so there is a digraph or a state + + + align:start position:0% +minus P so there is a digraph or a state +machine that describes the gamblers + + align:start position:0% +machine that describes the gamblers + + + align:start position:0% +machine that describes the gamblers +ruined problem as a probabilistic walk + + align:start position:0% +ruined problem as a probabilistic walk + + + align:start position:0% +ruined problem as a probabilistic walk +on a graph and the typical kind of + + align:start position:0% +on a graph and the typical kind of + + + align:start position:0% +on a graph and the typical kind of +question that we would ask about a + + align:start position:0% +question that we would ask about a + + + align:start position:0% +question that we would ask about a +random walk on a graph would be what's + + align:start position:0% +random walk on a graph would be what's + + + align:start position:0% +random walk on a graph would be what's +the probability of reaching + + align:start position:0% +the probability of reaching + + + align:start position:0% +the probability of reaching +hey the target before reaching zero + + align:start position:0% +hey the target before reaching zero + + + align:start position:0% +hey the target before reaching zero +bankrupt given that you're starting at + + align:start position:0% +bankrupt given that you're starting at + + + align:start position:0% +bankrupt given that you're starting at +some state estate and so any books come + + align:start position:0% +some state estate and so any books come + + + align:start position:0% +some state estate and so any books come +up in a bunch of quite different + + align:start position:0% +up in a bunch of quite different + + + align:start position:0% +up in a bunch of quite different +settings for example in physics Brownian + + align:start position:0% +settings for example in physics Brownian + + + align:start position:0% +settings for example in physics Brownian +motion is the random motion of a + + align:start position:0% +motion is the random motion of a + + + align:start position:0% +motion is the random motion of a +particle that's being buffeted by atomic + + align:start position:0% +particle that's being buffeted by atomic + + + align:start position:0% +particle that's being buffeted by atomic +forces and it's modeled by saying that + + align:start position:0% +forces and it's modeled by saying that + + + align:start position:0% +forces and it's modeled by saying that +this particle can move in any direction + + align:start position:0% +this particle can move in any direction + + + align:start position:0% +this particle can move in any direction +in three space and chosen in uniformly + + align:start position:0% +in three space and chosen in uniformly + + + align:start position:0% +in three space and chosen in uniformly +at random and the theory of Brownian + + align:start position:0% +at random and the theory of Brownian + + + align:start position:0% +at random and the theory of Brownian +motion it had been observed first + + align:start position:0% +motion it had been observed first + + + align:start position:0% +motion it had been observed first +without being understood Einstein was + + align:start position:0% +without being understood Einstein was + + + align:start position:0% +without being understood Einstein was +the first one to come up with a random + + align:start position:0% +the first one to come up with a random + + + align:start position:0% +the first one to come up with a random +walk model and corresponding theorems + + align:start position:0% +walk model and corresponding theorems + + + align:start position:0% +walk model and corresponding theorems +about the behavior of particles under + + align:start position:0% +about the behavior of particles under + + + align:start position:0% +about the behavior of particles under +Brownian motion in fact that was one of + + align:start position:0% +Brownian motion in fact that was one of + + + align:start position:0% +Brownian motion in fact that was one of +the main components of his Nobel Prize + + align:start position:0% +the main components of his Nobel Prize + + + align:start position:0% +the main components of his Nobel Prize +he wasn't given a Nobel Prize for + + align:start position:0% +he wasn't given a Nobel Prize for + + + align:start position:0% +he wasn't given a Nobel Prize for +relativity at the time because it had + + align:start position:0% +relativity at the time because it had + + + align:start position:0% +relativity at the time because it had +not yet been firmly proven although it + + align:start position:0% +not yet been firmly proven although it + + + align:start position:0% +not yet been firmly proven although it +was widely celebrated another case is in + + align:start position:0% +was widely celebrated another case is in + + + align:start position:0% +was widely celebrated another case is in +finance we've already seen how gamblers + + align:start position:0% +finance we've already seen how gamblers + + + align:start position:0% +finance we've already seen how gamblers +ruin reflects or seems to reflect the + + align:start position:0% +ruin reflects or seems to reflect the + + + align:start position:0% +ruin reflects or seems to reflect the +biased random oscillation of price of + + align:start position:0% +biased random oscillation of price of + + + align:start position:0% +biased random oscillation of price of +stock prices over time and we will see + + align:start position:0% +stock prices over time and we will see + + + align:start position:0% +stock prices over time and we will see +at the end of this set of videos an + + align:start position:0% +at the end of this set of videos an + + + align:start position:0% +at the end of this set of videos an +application of random walks on a graph + + align:start position:0% +application of random walks on a graph + + + align:start position:0% +application of random walks on a graph +to model web search and clustering of a + + align:start position:0% +to model web search and clustering of a + + + align:start position:0% +to model web search and clustering of a +focus on vertices in a digraph so the + + align:start position:0% +focus on vertices in a digraph so the + + + align:start position:0% +focus on vertices in a digraph so the +general kinds of questions that come up + + align:start position:0% +general kinds of questions that come up + + + align:start position:0% +general kinds of questions that come up +when you're talking about random walks + + align:start position:0% +when you're talking about random walks + + + align:start position:0% +when you're talking about random walks +on graphs are illustrated by this simple + + align:start position:0% +on graphs are illustrated by this simple + + + align:start position:0% +on graphs are illustrated by this simple +three state example with blue orange and + + align:start position:0% +three state example with blue orange and + + + align:start position:0% +three state example with blue orange and +green we might ask for example starting + + align:start position:0% +green we might ask for example starting + + + align:start position:0% +green we might ask for example starting +at state B what's the probability of + + align:start position:0% +at state B what's the probability of + + + align:start position:0% +at state B what's the probability of +reaching state all in seven steps and + + align:start position:0% +reaching state all in seven steps and + + + align:start position:0% +reaching state all in seven steps and +that would be easy enough to calculate + + align:start position:0% +that would be easy enough to calculate + + + align:start position:0% +that would be easy enough to calculate +in this small example but it would be a + + align:start position:0% +in this small example but it would be a + + + align:start position:0% +in this small example but it would be a +typical question a more interesting + + align:start position:0% +typical question a more interesting + + + align:start position:0% +typical question a more interesting +general question would be what's the + + align:start position:0% +general question would be what's the + + + align:start position:0% +general question would be what's the +average number of steps that it takes to + + align:start position:0% +average number of steps that it takes to + + + align:start position:0% +average number of steps that it takes to +get from B to all I mean you could with + + align:start position:0% +get from B to all I mean you could with + + + align:start position:0% +get from B to all I mean you could with +one problem with probability 1/4 you go + + align:start position:0% +one problem with probability 1/4 you go + + + align:start position:0% +one problem with probability 1/4 you go +there in one step but with probability + + align:start position:0% +there in one step but with probability + + + align:start position:0% +there in one step but with probability +1/8 you go there in three steps and so + + align:start position:0% +1/8 you go there in three steps and so + + + align:start position:0% +1/8 you go there in three steps and so +on you can + + align:start position:0% +on you can + + + align:start position:0% +on you can +again explicitly and easily enough what + + align:start position:0% +again explicitly and easily enough what + + + align:start position:0% +again explicitly and easily enough what +the average number of steps would be to + + align:start position:0% +the average number of steps would be to + + + align:start position:0% +the average number of steps would be to +always in this simple example and will + + align:start position:0% +always in this simple example and will + + + align:start position:0% +always in this simple example and will +shortly remark about general ways to + + align:start position:0% +shortly remark about general ways to + + + align:start position:0% +shortly remark about general ways to +solve that problem and finally you can + + align:start position:0% +solve that problem and finally you can + + + align:start position:0% +solve that problem and finally you can +ask a gamblers ruin type question what's + + align:start position:0% +ask a gamblers ruin type question what's + + + align:start position:0% +ask a gamblers ruin type question what's +the probability of starting at B of + + align:start position:0% +the probability of starting at B of + + + align:start position:0% +the probability of starting at B of +getting to G before oh well in this + + align:start position:0% +getting to G before oh well in this + + + align:start position:0% +getting to G before oh well in this +trivial example you can just read off + + align:start position:0% +trivial example you can just read off + + + align:start position:0% +trivial example you can just read off +the answer you are gonna get to G before + + align:start position:0% +the answer you are gonna get to G before + + + align:start position:0% +the answer you are gonna get to G before +oh with 50/50 probability because from B + + align:start position:0% +oh with 50/50 probability because from B + + + align:start position:0% +oh with 50/50 probability because from B +you have to go one place or the other + + align:start position:0% +you have to go one place or the other + + + align:start position:0% +you have to go one place or the other +with equal probability but in general + + align:start position:0% +with equal probability but in general + + + align:start position:0% +with equal probability but in general +this becomes a more interesting and + + align:start position:0% +this becomes a more interesting and + + + align:start position:0% +this becomes a more interesting and +complicated question which you can solve + + align:start position:0% +complicated question which you can solve + + + align:start position:0% +complicated question which you can solve +by methods that we're about to lay out + + align:start position:0% +by methods that we're about to lay out + + + align:start position:0% +by methods that we're about to lay out +let me just remind you that we've + + align:start position:0% +let me just remind you that we've + + + align:start position:0% +let me just remind you that we've +already seen an interesting and + + align:start position:0% +already seen an interesting and + + + align:start position:0% +already seen an interesting and +illustrative example of random walk on a + + align:start position:0% +illustrative example of random walk on a + + + align:start position:0% +illustrative example of random walk on a +graph when we were looking at Toyne + + align:start position:0% +graph when we were looking at Toyne + + + align:start position:0% +graph when we were looking at Toyne +course at coin tosses the problem for + + align:start position:0% +course at coin tosses the problem for + + + align:start position:0% +course at coin tosses the problem for +example of if I toss a fair coin and I + + align:start position:0% +example of if I toss a fair coin and I + + + align:start position:0% +example of if I toss a fair coin and I +wait for three consecutive tosses that + + align:start position:0% +wait for three consecutive tosses that + + + align:start position:0% +wait for three consecutive tosses that +form the pattern h th or the pattern t + + align:start position:0% +form the pattern h th or the pattern t + + + align:start position:0% +form the pattern h th or the pattern t +th and i want to know what's the + + align:start position:0% +th and i want to know what's the + + + align:start position:0% +th and i want to know what's the +probability of winning because H th + + align:start position:0% +probability of winning because H th + + + align:start position:0% +probability of winning because H th +comes before t th I can model that with + + align:start position:0% +comes before t th I can model that with + + + align:start position:0% +comes before t th I can model that with +a we said as with an infinite tree + + align:start position:0% +a we said as with an infinite tree + + + align:start position:0% +a we said as with an infinite tree +diagram using our tree method for + + align:start position:0% +diagram using our tree method for + + + align:start position:0% +diagram using our tree method for +forming probability spaces but the tree + + align:start position:0% +forming probability spaces but the tree + + + align:start position:0% +forming probability spaces but the tree +was very recursively defined sub trees + + align:start position:0% +was very recursively defined sub trees + + + align:start position:0% +was very recursively defined sub trees +were isomorphic to the original tree + + align:start position:0% +were isomorphic to the original tree + + + align:start position:0% +were isomorphic to the original tree +which allowed us in fact to come up with + + align:start position:0% +which allowed us in fact to come up with + + + align:start position:0% +which allowed us in fact to come up with +a finite description of the infinite + + align:start position:0% +a finite description of the infinite + + + align:start position:0% +a finite description of the infinite +tree that amounted to a finite state + + align:start position:0% +tree that amounted to a finite state + + + align:start position:0% +tree that amounted to a finite state +machine or a finite graph so let's look + + align:start position:0% +machine or a finite graph so let's look + + + align:start position:0% +machine or a finite graph so let's look +at that example in more detail if I'm + + align:start position:0% +at that example in more detail if I'm + + + align:start position:0% +at that example in more detail if I'm +trying to model the coin flipping thing + + align:start position:0% +trying to model the coin flipping thing + + + align:start position:0% +trying to model the coin flipping thing +like we start off in a state where the + + align:start position:0% +like we start off in a state where the + + + align:start position:0% +like we start off in a state where the +previous two flips don't exist I haven't + + align:start position:0% +previous two flips don't exist I haven't + + + align:start position:0% +previous two flips don't exist I haven't +flipped anything yet the state's going + + align:start position:0% +flipped anything yet the state's going + + + align:start position:0% +flipped anything yet the state's going +to record the values of the previous two + + align:start position:0% +to record the values of the previous two + + + align:start position:0% +to record the values of the previous two +flips and with no prior flips there's a + + align:start position:0% +flips and with no prior flips there's a + + + align:start position:0% +flips and with no prior flips there's a +50-50 chance that the first flip will be + + align:start position:0% +50-50 chance that the first flip will be + + + align:start position:0% +50-50 chance that the first flip will be +H in which case I'm in the state with + + align:start position:0% +H in which case I'm in the state with + + + align:start position:0% +H in which case I'm in the state with +just an H and nothing proceeding or + + align:start position:0% +just an H and nothing proceeding or + + + align:start position:0% +just an H and nothing proceeding or +there's a 50/50 chance I flip a T in + + align:start position:0% +there's a 50/50 chance I flip a T in + + + align:start position:0% +there's a 50/50 chance I flip a T in +which case I'm in the state in which + + align:start position:0% +which case I'm in the state in which + + + align:start position:0% +which case I'm in the state in which +there's been a T and nothing previous + + align:start position:0% +there's been a T and nothing previous + + + align:start position:0% +there's been a T and nothing previous +but I can already say something then + + align:start position:0% +but I can already say something then + + + align:start position:0% +but I can already say something then +about the probability of tossing h th + + align:start position:0% +about the probability of tossing h th + + + align:start position:0% +about the probability of tossing h th +before t th namely the probability of + + align:start position:0% +before t th namely the probability of + + + align:start position:0% +before t th namely the probability of +winning probability of winning is of + + align:start position:0% +winning probability of winning is of + + + align:start position:0% +winning probability of winning is of +course the probability of winning given + + align:start position:0% +course the probability of winning given + + + align:start position:0% +course the probability of winning given +that I start at the start state with no + + align:start position:0% +that I start at the start state with no + + + align:start position:0% +that I start at the start state with no +prior flips but the probability that I + + align:start position:0% +prior flips but the probability that I + + + align:start position:0% +prior flips but the probability that I +win starting here is simply the + + align:start position:0% +win starting here is simply the + + + align:start position:0% +win starting here is simply the +probability that I win at starting at + + align:start position:0% +probability that I win at starting at + + + align:start position:0% +probability that I win at starting at +the state noting age and/or the + + align:start position:0% +the state noting age and/or the + + + align:start position:0% +the state noting age and/or the +probability that I win at the state + + align:start position:0% +probability that I win at the state + + + align:start position:0% +probability that I win at the state +started nothing T with the two + + align:start position:0% +started nothing T with the two + + + align:start position:0% +started nothing T with the two +probabilities weighted equally since + + align:start position:0% +probabilities weighted equally since + + + align:start position:0% +probabilities weighted equally since +this is a fair coin and there's a 50/50 + + align:start position:0% +this is a fair coin and there's a 50/50 + + + align:start position:0% +this is a fair coin and there's a 50/50 +chance of going each way that is the + + align:start position:0% +chance of going each way that is the + + + align:start position:0% +chance of going each way that is the +probability of winning given no prior + + align:start position:0% +probability of winning given no prior + + + align:start position:0% +probability of winning given no prior +tosses is half the probability of + + align:start position:0% +tosses is half the probability of + + + align:start position:0% +tosses is half the probability of +winning if the first toss is an H plus + + align:start position:0% +winning if the first toss is an H plus + + + align:start position:0% +winning if the first toss is an H plus +half the probability of winning if the + + align:start position:0% +half the probability of winning if the + + + align:start position:0% +half the probability of winning if the +first plus is a T this is just an + + align:start position:0% +first plus is a T this is just an + + + align:start position:0% +first plus is a T this is just an +application of the law of total + + align:start position:0% +application of the law of total + + + align:start position:0% +application of the law of total +probability so I'm continuing in this + + align:start position:0% +probability so I'm continuing in this + + + align:start position:0% +probability so I'm continuing in this +way let's expand more of the diagram so + + align:start position:0% +way let's expand more of the diagram so + + + align:start position:0% +way let's expand more of the diagram so +suppose that I have tossed a head and + + align:start position:0% +suppose that I have tossed a head and + + + align:start position:0% +suppose that I have tossed a head and +then after that I toss a head and I go + + align:start position:0% +then after that I toss a head and I go + + + align:start position:0% +then after that I toss a head and I go +to state h h or i toss it t and i go to + + align:start position:0% +to state h h or i toss it t and i go to + + + align:start position:0% +to state h h or i toss it t and i go to +state h T so here I'm just recording the + + align:start position:0% +state h T so here I'm just recording the + + + align:start position:0% +state h T so here I'm just recording the +previous two flips with the most recent + + align:start position:0% +previous two flips with the most recent + + + align:start position:0% +previous two flips with the most recent +one on the right okay this this + + align:start position:0% +one on the right okay this this + + + align:start position:0% +one on the right okay this this +structure of the state diagram tells us + + align:start position:0% +structure of the state diagram tells us + + + align:start position:0% +structure of the state diagram tells us +that if I want to know what the + + align:start position:0% +that if I want to know what the + + + align:start position:0% +that if I want to know what the +probability of winning given that I + + align:start position:0% +probability of winning given that I + + + align:start position:0% +probability of winning given that I +flipped exactly one head at the start + + align:start position:0% +flipped exactly one head at the start + + + align:start position:0% +flipped exactly one head at the start +the probability is simply by again total + + align:start position:0% +the probability is simply by again total + + + align:start position:0% +the probability is simply by again total +probability the probability of winning + + align:start position:0% +probability the probability of winning + + + align:start position:0% +probability the probability of winning +from HH weighted by 1/2 and the + + align:start position:0% +from HH weighted by 1/2 and the + + + align:start position:0% +from HH weighted by 1/2 and the +probability of winning from HK weighted + + align:start position:0% +probability of winning from HK weighted + + + align:start position:0% +probability of winning from HK weighted +by 1/2 and I wind up again with a simple + + align:start position:0% +by 1/2 and I wind up again with a simple + + + align:start position:0% +by 1/2 and I wind up again with a simple +linear equation that connects the + + align:start position:0% +linear equation that connects the + + + align:start position:0% +linear equation that connects the +probability of winning in one state with + + align:start position:0% +probability of winning in one state with + + + align:start position:0% +probability of winning in one state with +the probability of winning in the states + + align:start position:0% +the probability of winning in the states + + + align:start position:0% +the probability of winning in the states +that it goes to let's continue and do + + align:start position:0% +that it goes to let's continue and do + + + align:start position:0% +that it goes to let's continue and do +another example so it's like wise if I + + align:start position:0% +another example so it's like wise if I + + + align:start position:0% +another example so it's like wise if I +expand what happens after I flip a tea + + align:start position:0% +expand what happens after I flip a tea + + + align:start position:0% +expand what happens after I flip a tea +or an H after having flipped the first + + align:start position:0% +or an H after having flipped the first + + + align:start position:0% +or an H after having flipped the first +head I get a corresponding equation that + + align:start position:0% +head I get a corresponding equation that + + + align:start position:0% +head I get a corresponding equation that +the probability of winning after a + + align:start position:0% +the probability of winning after a + + + align:start position:0% +the probability of winning after a +single tail is the same as the problem + + align:start position:0% +single tail is the same as the problem + + + align:start position:0% +single tail is the same as the problem +half the probability of winning with a + + align:start position:0% +half the probability of winning with a + + + align:start position:0% +half the probability of winning with a +tail followed by an H or a tail followed + + align:start position:0% +tail followed by an H or a tail followed + + + align:start position:0% +tail followed by an H or a tail followed +by a tail this is a more interesting + + align:start position:0% +by a tail this is a more interesting + + + align:start position:0% +by a tail this is a more interesting +part of the diagram we're supposed that + + align:start position:0% +part of the diagram we're supposed that + + + align:start position:0% +part of the diagram we're supposed that +my past two flips have been two H's well + + align:start position:0% +my past two flips have been two H's well + + + align:start position:0% +my past two flips have been two H's well +if I flip an H again then I'm back in + + align:start position:0% +if I flip an H again then I'm back in + + + align:start position:0% +if I flip an H again then I'm back in +state where the previous two flips were + + align:start position:0% +state where the previous two flips were + + + align:start position:0% +state where the previous two flips were +ages or if I flip at a that I'm in this + + align:start position:0% +ages or if I flip at a that I'm in this + + + align:start position:0% +ages or if I flip at a that I'm in this +state a + + align:start position:0% +state a + + + align:start position:0% +state a +hey where the previous flips were an H + + align:start position:0% +hey where the previous flips were an H + + + align:start position:0% +hey where the previous flips were an H +and T in that order and that tells me if + + align:start position:0% +and T in that order and that tells me if + + + align:start position:0% +and T in that order and that tells me if +I want to know about the probability of + + align:start position:0% +I want to know about the probability of + + + align:start position:0% +I want to know about the probability of +winning even HH now it's the probability + + align:start position:0% +winning even HH now it's the probability + + + align:start position:0% +winning even HH now it's the probability +of winning given HH plus the probability + + align:start position:0% +of winning given HH plus the probability + + + align:start position:0% +of winning given HH plus the probability +of winning given HT and again it's a + + align:start position:0% +of winning given HT and again it's a + + + align:start position:0% +of winning given HT and again it's a +linear equation connecting up the + + align:start position:0% +linear equation connecting up the + + + align:start position:0% +linear equation connecting up the +probability of winning in one state with + + align:start position:0% +probability of winning in one state with + + + align:start position:0% +probability of winning in one state with +the probability of winning in other + + align:start position:0% +the probability of winning in other + + + align:start position:0% +the probability of winning in other +states possibly itself but there's no + + align:start position:0% +states possibly itself but there's no + + + align:start position:0% +states possibly itself but there's no +circularity here it's just a system of + + align:start position:0% +circularity here it's just a system of + + + align:start position:0% +circularity here it's just a system of +linear equations well there's what the + + align:start position:0% +linear equations well there's what the + + + align:start position:0% +linear equations well there's what the +whole diagram looks like in particular + + align:start position:0% +whole diagram looks like in particular + + + align:start position:0% +whole diagram looks like in particular +once you've flipped HT if you then flip + + align:start position:0% +once you've flipped HT if you then flip + + + align:start position:0% +once you've flipped HT if you then flip +an H you've won because you got two H th + + align:start position:0% +an H you've won because you got two H th + + + align:start position:0% +an H you've won because you got two H th +first and you stay in the wins state + + align:start position:0% +first and you stay in the wins state + + + align:start position:0% +first and you stay in the wins state +forever or alternatively once you flip + + align:start position:0% +forever or alternatively once you flip + + + align:start position:0% +forever or alternatively once you flip +TT if you flip an H you've lost because + + align:start position:0% +TT if you flip an H you've lost because + + + align:start position:0% +TT if you flip an H you've lost because +TT has come up first + + align:start position:0% +TT has come up first + + + align:start position:0% +TT has come up first +if you flip the T again you stay in + + align:start position:0% +if you flip the T again you stay in + + + align:start position:0% +if you flip the T again you stay in +state TP and what we can say is the + + align:start position:0% +state TP and what we can say is the + + + align:start position:0% +state TP and what we can say is the +probability of winning if you're in the + + align:start position:0% +probability of winning if you're in the + + + align:start position:0% +probability of winning if you're in the +win state is 1 and the probability of + + align:start position:0% +win state is 1 and the probability of + + + align:start position:0% +win state is 1 and the probability of +winning if you're in the lose state is 0 + + align:start position:0% +winning if you're in the lose state is 0 + + + align:start position:0% +winning if you're in the lose state is 0 +and overall I simply have this system of + + align:start position:0% +and overall I simply have this system of + + + align:start position:0% +and overall I simply have this system of +linear equations for the probability of + + align:start position:0% +linear equations for the probability of + + + align:start position:0% +linear equations for the probability of +winning in one state given other states + + align:start position:0% +winning in one state given other states + + + align:start position:0% +winning in one state given other states +and I can solve these linear equations + + align:start position:0% +and I can solve these linear equations + + + align:start position:0% +and I can solve these linear equations +to find the probability of winning in + + align:start position:0% +to find the probability of winning in + + + align:start position:0% +to find the probability of winning in +the start state which is simply the + + align:start position:0% +the start state which is simply the + + + align:start position:0% +the start state which is simply the +probability of winning so looking back + + align:start position:0% +probability of winning so looking back + + + align:start position:0% +probability of winning so looking back +at our questions for random walks where + + align:start position:0% +at our questions for random walks where + + + align:start position:0% +at our questions for random walks where +we asked whether the probability of + + align:start position:0% +we asked whether the probability of + + + align:start position:0% +we asked whether the probability of +reaching oh and seven steps starting at + + align:start position:0% +reaching oh and seven steps starting at + + + align:start position:0% +reaching oh and seven steps starting at +B what's the probability of that what's + + align:start position:0% +B what's the probability of that what's + + + align:start position:0% +B what's the probability of that what's +the average number of steps to go from B + + align:start position:0% +the average number of steps to go from B + + + align:start position:0% +the average number of steps to go from B +to oh what's the probability of reaching + + align:start position:0% +to oh what's the probability of reaching + + + align:start position:0% +to oh what's the probability of reaching +G before Oh starting it B in every case + + align:start position:0% +G before Oh starting it B in every case + + + align:start position:0% +G before Oh starting it B in every case +these questions can be formulated simply + + align:start position:0% +these questions can be formulated simply + + + align:start position:0% +these questions can be formulated simply +as solving systems of linear equations + + align:start position:0% +as solving systems of linear equations + + + align:start position:0% +as solving systems of linear equations +whose structure directly reflects the + + align:start position:0% +whose structure directly reflects the + + + align:start position:0% +whose structure directly reflects the +structure of the digraph \ No newline at end of file diff --git a/0ABYYJSvkVk.txt b/0ABYYJSvkVk.txt new file mode 100644 index 0000000000000000000000000000000000000000..e5e7558a5df8556010a3492b3d295d31300a09ce --- /dev/null +++ b/0ABYYJSvkVk.txt @@ -0,0 +1,1443 @@ +align:start position:0% + +scattering states are energy ion states + + align:start position:0% +scattering states are energy ion states + + + align:start position:0% +scattering states are energy ion states +that cannot be + + align:start position:0% +that cannot be + + + align:start position:0% +that cannot be +normalized and + + align:start position:0% +normalized and + + + align:start position:0% +normalized and +uh when you say this cannot be + + align:start position:0% +uh when you say this cannot be + + + align:start position:0% +uh when you say this cannot be +normalized so what's the use of them + + align:start position:0% +normalized so what's the use of them + + + align:start position:0% +normalized so what's the use of them +they don't represent + + align:start position:0% +they don't represent + + + align:start position:0% +they don't represent +particles well it's like the e to the I + + align:start position:0% +particles well it's like the e to the I + + + align:start position:0% +particles well it's like the e to the I +PX over H bar those infinite plane + + align:start position:0% +PX over H bar those infinite plane + + + align:start position:0% +PX over H bar those infinite plane +waves each one by itself not be + + align:start position:0% +waves each one by itself not be + + + align:start position:0% +waves each one by itself not be +normalized but you can construct wave + + align:start position:0% +normalized but you can construct wave + + + align:start position:0% +normalized but you can construct wave +packets that are normalized so the whole + + align:start position:0% +packets that are normalized so the whole + + + align:start position:0% +packets that are normalized so the whole +intuition that you get with scattering + + align:start position:0% +intuition that you get with scattering + + + align:start position:0% +intuition that you get with scattering +States is based on the idea that we're + + align:start position:0% +States is based on the idea that we're + + + align:start position:0% +States is based on the idea that we're +going to construct energy states this + + align:start position:0% +going to construct energy states this + + + align:start position:0% +going to construct energy states this +time we cannot think of them as states + + align:start position:0% +time we cannot think of them as states + + + align:start position:0% +time we cannot think of them as states +of a particle bound States yes we can + + align:start position:0% +of a particle bound States yes we can + + + align:start position:0% +of a particle bound States yes we can +think of them they're + + align:start position:0% +think of them they're + + + align:start position:0% +think of them they're +normalizable but this energy I States + + align:start position:0% +normalizable but this energy I States + + + align:start position:0% +normalizable but this energy I States +unbounded scattering states are not + + align:start position:0% +unbounded scattering states are not + + + align:start position:0% +unbounded scattering states are not +states of one particle so we definitely + + align:start position:0% +states of one particle so we definitely + + + align:start position:0% +states of one particle so we definitely +have to go back and produce wave + + align:start position:0% +have to go back and produce wave + + + align:start position:0% +have to go back and produce wave +packets but the intuition from those + + align:start position:0% +packets but the intuition from those + + + align:start position:0% +packets but the intuition from those +energy ion States is very valuable so + + align:start position:0% +energy ion States is very valuable so + + + align:start position:0% +energy ion States is very valuable so +scattering + + align:start position:0% + + + + align:start position:0% + +States states and we call them sometimes + + align:start position:0% +States states and we call them sometimes + + + align:start position:0% +States states and we call them sometimes +scattering States because they look like + + align:start position:0% +scattering States because they look like + + + align:start position:0% +scattering States because they look like +the process of scattering this will be + + align:start position:0% +the process of scattering this will be + + + align:start position:0% +the process of scattering this will be +uh + + align:start position:0% +uh + + + align:start position:0% +uh +non + + align:start position:0% +non + + + align:start position:0% +non +normalizable + + align:start position:0% + + + + align:start position:0% + +energy ion + + align:start position:0% + + + + align:start position:0% + +States and you've played a little with + + align:start position:0% +States and you've played a little with + + + align:start position:0% +States and you've played a little with +some of them and we'll now study one + + align:start position:0% +some of them and we'll now study one + + + align:start position:0% +some of them and we'll now study one +case in detail we'll study a couple of + + align:start position:0% +case in detail we'll study a couple of + + + align:start position:0% +case in detail we'll study a couple of +cases between today and next lecture so + + align:start position:0% +cases between today and next lecture so + + + align:start position:0% +cases between today and next lecture so +the step + + align:start position:0% + + + + align:start position:0% + +potential and the step potential is a + + align:start position:0% +potential and the step potential is a + + + align:start position:0% +potential and the step potential is a +potential that is zero up to X equal + + align:start position:0% +potential that is zero up to X equal + + + align:start position:0% +potential that is zero up to X equal +Z and here's the x axis and then + + align:start position:0% +Z and here's the x axis and then + + + align:start position:0% +Z and here's the x axis and then +suddenly there's a step at V + + align:start position:0% + + + + align:start position:0% + +KN and here is the + + align:start position:0% + + + + align:start position:0% + +potential so the poent wave this is here + + align:start position:0% +potential so the poent wave this is here + + + align:start position:0% +potential so the poent wave this is here +goes + + align:start position:0% +goes + + + align:start position:0% +goes +up it's a + + align:start position:0% + + + + align:start position:0% + +step and + + align:start position:0% +step and + + + align:start position:0% +step and +any energy I State here has to be bigger + + align:start position:0% +any energy I State here has to be bigger + + + align:start position:0% +any energy I State here has to be bigger +the energy has to be bigger than the + + align:start position:0% +the energy has to be bigger than the + + + align:start position:0% +the energy has to be bigger than the +lowest point of the potential you know + + align:start position:0% +lowest point of the potential you know + + + align:start position:0% +lowest point of the potential you know +that you cannot have an energy that is + + align:start position:0% +that you cannot have an energy that is + + + align:start position:0% +that you cannot have an energy that is +like that less because this would have + + align:start position:0% +like that less because this would have + + + align:start position:0% +like that less because this would have +um Decay exponentially for infinite + + align:start position:0% +um Decay exponentially for infinite + + + align:start position:0% +um Decay exponentially for infinite +distance it just all over it would have + + align:start position:0% +distance it just all over it would have + + + align:start position:0% +distance it just all over it would have +to Decay exponentially it's + + align:start position:0% +to Decay exponentially it's + + + align:start position:0% +to Decay exponentially it's +impossible so all the energies States I + + align:start position:0% +impossible so all the energies States I + + + align:start position:0% +impossible so all the energies States I +States here must have positive energy so + + align:start position:0% +States here must have positive energy so + + + align:start position:0% +States here must have positive energy so +we have actually qualitatively two + + align:start position:0% +we have actually qualitatively two + + + align:start position:0% +we have actually qualitatively two +possibilities the energy may be less + + align:start position:0% +possibilities the energy may be less + + + align:start position:0% +possibilities the energy may be less +than V not might be greater than V + + align:start position:0% +than V not might be greater than V + + + align:start position:0% +than V not might be greater than V +not it would look like you have to solve + + align:start position:0% +not it would look like you have to solve + + + align:start position:0% +not it would look like you have to solve +the problem two times happily we'll + + align:start position:0% +the problem two times happily we'll + + + align:start position:0% +the problem two times happily we'll +solve one it then let the other happen + + align:start position:0% +solve one it then let the other happen + + + align:start position:0% +solve one it then let the other happen +um by analytic continuation so here is + + align:start position:0% +um by analytic continuation so here is + + + align:start position:0% +um by analytic continuation so here is +the energy I'll take the energy greater + + align:start position:0% +the energy I'll take the energy greater + + + align:start position:0% +the energy I'll take the energy greater +than V kn + + align:start position:0% +than V kn + + + align:start position:0% +than V kn +but whatever is the energy even if it's + + align:start position:0% +but whatever is the energy even if it's + + + align:start position:0% +but whatever is the energy even if it's +less than V KN the solution over here is + + align:start position:0% +less than V KN the solution over here is + + + align:start position:0% +less than V KN the solution over here is +going to be an exponential or a cosine + + align:start position:0% +going to be an exponential or a cosine + + + align:start position:0% +going to be an exponential or a cosine +and a sign a non decaying function and + + align:start position:0% +and a sign a non decaying function and + + + align:start position:0% +and a sign a non decaying function and +therefore it can't be normalized because + + align:start position:0% +therefore it can't be normalized because + + + align:start position:0% +therefore it can't be normalized because +it's non decaying forever and ever so it + + align:start position:0% +it's non decaying forever and ever so it + + + align:start position:0% +it's non decaying forever and ever so it +cannot be + + align:start position:0% +cannot be + + + align:start position:0% +cannot be +normalized so how do we write the + + align:start position:0% +normalized so how do we write the + + + align:start position:0% +normalized so how do we write the +solution for the energy ion State it's a + + align:start position:0% +solution for the energy ion State it's a + + + align:start position:0% +solution for the energy ion State it's a +p of + + align:start position:0% +p of + + + align:start position:0% +p of +x + + align:start position:0% +x + + + align:start position:0% +x +well I should write two formulas a + + align:start position:0% +well I should write two formulas a + + + align:start position:0% +well I should write two formulas a +formula for a W for what's happening on + + align:start position:0% +formula for a W for what's happening on + + + align:start position:0% +formula for a W for what's happening on +the left side and a formula for what's + + align:start position:0% +the left side and a formula for what's + + + align:start position:0% +the left side and a formula for what's +happening on the right + + align:start position:0% + + + + align:start position:0% + +side now I have a choice actually here + + align:start position:0% +side now I have a choice actually here + + + align:start position:0% +side now I have a choice actually here +there's two ways of visualizing this I + + align:start position:0% +there's two ways of visualizing this I + + + align:start position:0% +there's two ways of visualizing this I +can visualize it as a wave that is + + align:start position:0% +can visualize it as a wave that is + + + align:start position:0% +can visualize it as a wave that is +coming from the left moving + + align:start position:0% +coming from the left moving + + + align:start position:0% +coming from the left moving +here or a wave that is coming from the + + align:start position:0% + + + + align:start position:0% + +right so let's visualize this solution + + align:start position:0% +right so let's visualize this solution + + + align:start position:0% +right so let's visualize this solution +as a wave that's coming from the left it + + align:start position:0% +as a wave that's coming from the left it + + + align:start position:0% +as a wave that's coming from the left it +will be a little easier so I will write + + align:start position:0% +will be a little easier so I will write + + + align:start position:0% +will be a little easier so I will write +it a e to the i k + + align:start position:0% +it a e to the i k + + + align:start position:0% +it a e to the i k +x okay why is it coming from the left uh + + align:start position:0% +x okay why is it coming from the left uh + + + align:start position:0% +x okay why is it coming from the left uh +because if you put the energy that I + + align:start position:0% +because if you put the energy that I + + + align:start position:0% +because if you put the energy that I +will not put it is in stationary State + + align:start position:0% +will not put it is in stationary State + + + align:start position:0% +will not put it is in stationary State +presuma this is a state with some fixed + + align:start position:0% +presuma this is a state with some fixed + + + align:start position:0% +presuma this is a state with some fixed +energy it would have a factor e to the + + align:start position:0% +energy it would have a factor e to the + + + align:start position:0% +energy it would have a factor e to the +minus i e t over H bar and when you see + + align:start position:0% +minus i e t over H bar and when you see + + + align:start position:0% +minus i e t over H bar and when you see +KX minus E you know that that's a wave + + align:start position:0% +KX minus E you know that that's a wave + + + align:start position:0% +KX minus E you know that that's a wave +that is moving to the right so + + align:start position:0% +that is moving to the right so + + + align:start position:0% +that is moving to the right so +this a e to the I KX is moving to the + + align:start position:0% + + + + align:start position:0% + +right and then what will happen + + align:start position:0% + + + + align:start position:0% + +now it's a matter of finding a solution + + align:start position:0% +now it's a matter of finding a solution + + + align:start position:0% +now it's a matter of finding a solution +of shers equation so you can try to find + + align:start position:0% +of shers equation so you can try to find + + + align:start position:0% +of shers equation so you can try to find +the solution of shinger equations but + + align:start position:0% +the solution of shinger equations but + + + align:start position:0% +the solution of shinger equations but +you have to write some answers for + + align:start position:0% +you have to write some answers for + + + align:start position:0% +you have to write some answers for +What's happening on the + + align:start position:0% + + + + align:start position:0% + +right I will write an aners here that + + align:start position:0% +right I will write an aners here that + + + align:start position:0% +right I will write an aners here that +will put c e to the i k bar + + align:start position:0% +will put c e to the i k bar + + + align:start position:0% +will put c e to the i k bar +X another K well we'll see now what + + align:start position:0% +X another K well we'll see now what + + + align:start position:0% +X another K well we'll see now what +those Ks are um I say the following here + + align:start position:0% +those Ks are um I say the following here + + + align:start position:0% +those Ks are um I say the following here +the energy is bigger than the potential + + align:start position:0% +the energy is bigger than the potential + + + align:start position:0% +the energy is bigger than the potential +so it has to be a + + align:start position:0% +so it has to be a + + + align:start position:0% +so it has to be a +wave but here the energy is still bigger + + align:start position:0% +wave but here the energy is still bigger + + + align:start position:0% +wave but here the energy is still bigger +than the potential so it also must be a + + align:start position:0% +than the potential so it also must be a + + + align:start position:0% +than the potential so it also must be a +wave but a wave with different kinetic + + align:start position:0% +wave but a wave with different kinetic + + + align:start position:0% +wave but a wave with different kinetic +energy different momentum therefore + + align:start position:0% +energy different momentum therefore + + + align:start position:0% +energy different momentum therefore +different the brogly wavelength and + + align:start position:0% +different the brogly wavelength and + + + align:start position:0% +different the brogly wavelength and +different K but we know from sherer's + + align:start position:0% +different K but we know from sherer's + + + align:start position:0% +different K but we know from sherer's +equation what that should be this wave + + align:start position:0% +equation what that should be this wave + + + align:start position:0% +equation what that should be this wave +is also moving to the right because + + align:start position:0% +is also moving to the right because + + + align:start position:0% +is also moving to the right because +probably if I have a wave mov moving to + + align:start position:0% +probably if I have a wave mov moving to + + + align:start position:0% +probably if I have a wave mov moving to +the right here it produces some + + align:start position:0% +the right here it produces some + + + align:start position:0% +the right here it produces some +transmitted wave to the + + align:start position:0% +transmitted wave to the + + + align:start position:0% +transmitted wave to the +right but then um you could try solving + + align:start position:0% +right but then um you could try solving + + + align:start position:0% +right but then um you could try solving +the shular equation with this it won't + + align:start position:0% +the shular equation with this it won't + + + align:start position:0% +the shular equation with this it won't +be enough because physically you would + + align:start position:0% +be enough because physically you would + + + align:start position:0% +be enough because physically you would +expect a wave bouncing back as well from + + align:start position:0% +expect a wave bouncing back as well from + + + align:start position:0% +expect a wave bouncing back as well from +here so I will put a + + align:start position:0% +here so I will put a + + + align:start position:0% +here so I will put a +b e to the- I KX that's a wave moving + + align:start position:0% +b e to the- I KX that's a wave moving + + + align:start position:0% +b e to the- I KX that's a wave moving +towards the left left with an unknown + + align:start position:0% + + + + align:start position:0% + +coefficient and now let's get those + + align:start position:0% +coefficient and now let's get those + + + align:start position:0% +coefficient and now let's get those +constants + + align:start position:0% + + + + align:start position:0% + +um I'll finish in two + + align:start position:0% + + + + align:start position:0% + +minutes what is K well if you have + + align:start position:0% +minutes what is K well if you have + + + align:start position:0% +minutes what is K well if you have +energy e you know that the energy is h² + + align:start position:0% +energy e you know that the energy is h² + + + align:start position:0% +energy e you know that the energy is h² +k^ 2 / 2 m you can look at the sh + + align:start position:0% +k^ 2 / 2 m you can look at the sh + + + align:start position:0% +k^ 2 / 2 m you can look at the sh +equation uh with zero potential over + + align:start position:0% +equation uh with zero potential over + + + align:start position:0% +equation uh with zero potential over +there and therefore k s is also 2 m e + + align:start position:0% +there and therefore k s is also 2 m e + + + align:start position:0% +there and therefore k s is also 2 m e +over h² is a combination you've been + + align:start position:0% +over h² is a combination you've been + + + align:start position:0% +over h² is a combination you've been +seeing quite a + + align:start position:0% +seeing quite a + + + align:start position:0% +seeing quite a +bit the intuition for K Bar should be + + align:start position:0% +bit the intuition for K Bar should be + + + align:start position:0% +bit the intuition for K Bar should be +that K bar squar is 2 m * the kinetic + + align:start position:0% +that K bar squar is 2 m * the kinetic + + + align:start position:0% +that K bar squar is 2 m * the kinetic +energy so it should be e - v/ + + align:start position:0% + + + + align:start position:0% + +H2 so these are K and K + + align:start position:0% +H2 so these are K and K + + + align:start position:0% +H2 so these are K and K +Bar and the wave function must be + + align:start position:0% +Bar and the wave function must be + + + align:start position:0% +Bar and the wave function must be +continuous at xal + + align:start position:0% +continuous at xal + + + align:start position:0% +continuous at xal +0 that gives you a + + + align:start position:0% +0 that gives you a + + + + align:start position:0% +0 that gives you a + +b equal to + + align:start position:0% +b equal to + + + align:start position:0% +b equal to +C at zero all the exponentials vanish + + align:start position:0% +C at zero all the exponentials vanish + + + align:start position:0% +C at zero all the exponentials vanish +and the derivative must be continuous at + + align:start position:0% +and the derivative must be continuous at + + + align:start position:0% +and the derivative must be continuous at +xal + + align:start position:0% +xal + + + align:start position:0% +xal +0 and the derivative being continuous is + + align:start position:0% +0 and the derivative being continuous is + + + align:start position:0% +0 and the derivative being continuous is +because there's no Delta function + + align:start position:0% +because there's no Delta function + + + align:start position:0% +because there's no Delta function +anywhere here so you have i k a that's a + + align:start position:0% +anywhere here so you have i k a that's a + + + align:start position:0% +anywhere here so you have i k a that's a +derivative of the first term minus i k b + + align:start position:0% +derivative of the first term minus i k b + + + align:start position:0% +derivative of the first term minus i k b +the same K in that region of course is + + align:start position:0% +the same K in that region of course is + + + align:start position:0% +the same K in that region of course is +equal to i k Bar + + align:start position:0% +equal to i k Bar + + + align:start position:0% +equal to i k Bar +C so from this you get + + align:start position:0% +C so from this you get + + + align:start position:0% +C so from this you get +a minus + + align:start position:0% + + + + align:start position:0% + +B is equal to K Bar over K + + align:start position:0% + + + + align:start position:0% + +C two equations and two unknowns and + + align:start position:0% +C two equations and two unknowns and + + + align:start position:0% +C two equations and two unknowns and +that's okay even though there are three + + align:start position:0% +that's okay even though there are three + + + align:start position:0% +that's okay even though there are three +coefficients because the way to think of + + align:start position:0% +coefficients because the way to think of + + + align:start position:0% +coefficients because the way to think of +this is that you're sending in some wave + + align:start position:0% +this is that you're sending in some wave + + + align:start position:0% +this is that you're sending in some wave +and you're going to get some reflection + + align:start position:0% +and you're going to get some reflection + + + align:start position:0% +and you're going to get some reflection +and some transmission so in some sense a + + align:start position:0% +and some transmission so in some sense a + + + align:start position:0% +and some transmission so in some sense a +is the input you could want to call it + + align:start position:0% +is the input you could want to call it + + + align:start position:0% +is the input you could want to call it +one or whatever so what we're looking + + align:start position:0% +one or whatever so what we're looking + + + align:start position:0% +one or whatever so what we're looking +for is what is B over a in what is C + + align:start position:0% +for is what is B over a in what is C + + + align:start position:0% +for is what is B over a in what is C +over + + align:start position:0% +over + + + align:start position:0% +over +a and these two equations uh it's a + + align:start position:0% +a and these two equations uh it's a + + + align:start position:0% +a and these two equations uh it's a +oneline computation I'll write the + + align:start position:0% +oneline computation I'll write the + + + align:start position:0% +oneline computation I'll write the +answer B over a is K - K Bar over k + K + + align:start position:0% +answer B over a is K - K Bar over k + K + + + align:start position:0% +answer B over a is K - K Bar over k + K +Bar do it for fun + + align:start position:0% +Bar do it for fun + + + align:start position:0% +Bar do it for fun +and c/ a is 2 K Over k + K + + align:start position:0% + + + + align:start position:0% + +Bar B gives you a sense of how much is + + align:start position:0% +Bar B gives you a sense of how much is + + + align:start position:0% +Bar B gives you a sense of how much is +reflected C how much is + + align:start position:0% +reflected C how much is + + + align:start position:0% +reflected C how much is +transmitted but this is the beginning + + align:start position:0% +transmitted but this is the beginning + + + align:start position:0% +transmitted but this is the beginning +because this is not a particle coming in + + align:start position:0% +because this is not a particle coming in + + + align:start position:0% +because this is not a particle coming in +so we'll have to build the packet and + + align:start position:0% +so we'll have to build the packet and + + + align:start position:0% +so we'll have to build the packet and +send it in and see how this relations + + align:start position:0% +send it in and see how this relations + + + align:start position:0% +send it in and see how this relations +tell you what's going to happen so it's + + align:start position:0% +tell you what's going to happen so it's + + + align:start position:0% +tell you what's going to happen so it's +a nice story that we will develop next + + align:start position:0% +a nice story that we will develop next + + + align:start position:0% +a nice story that we will develop next +time \ No newline at end of file diff --git a/0Va2dOLqUfM.txt b/0Va2dOLqUfM.txt new file mode 100644 index 0000000000000000000000000000000000000000..3b8ed3b9713d0b0a18a0e4138da0024fd6ec2741 --- /dev/null +++ b/0Va2dOLqUfM.txt @@ -0,0 +1,12467 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license + + align:start position:0% +a Creative Commons license + + + align:start position:0% +a Creative Commons license +your support will help MIT + + align:start position:0% +your support will help MIT + + + align:start position:0% +your support will help MIT +OpenCourseWare continue to offer high + + align:start position:0% +OpenCourseWare continue to offer high + + + align:start position:0% +OpenCourseWare continue to offer high +quality educational resources for free + + align:start position:0% +quality educational resources for free + + + align:start position:0% +quality educational resources for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so I'm using a few things here right I'm + + align:start position:0% +so I'm using a few things here right I'm + + + align:start position:0% +so I'm using a few things here right I'm +using the fact that KL is non-negative + + align:start position:0% +using the fact that KL is non-negative + + + align:start position:0% +using the fact that KL is non-negative +but KL is equal to 0 when I take twice + + align:start position:0% +but KL is equal to 0 when I take twice + + + align:start position:0% +but KL is equal to 0 when I take twice +the same argument so I know that this + + align:start position:0% +the same argument so I know that this + + + align:start position:0% +the same argument so I know that this +function is always non-negative and + + align:start position:0% +function is always non-negative and + + + align:start position:0% +function is always non-negative and +that's so that's theta and that's KL P + + align:start position:0% +that's so that's theta and that's KL P + + + align:start position:0% +that's so that's theta and that's KL P +theta star P theta and I know that at + + align:start position:0% +theta star P theta and I know that at + + + align:start position:0% +theta star P theta and I know that at +theta star its equal to 0 ok I could be + + align:start position:0% +theta star its equal to 0 ok I could be + + + align:start position:0% +theta star its equal to 0 ok I could be +in the case where I have this happening + + align:start position:0% +in the case where I have this happening + + + align:start position:0% +in the case where I have this happening +I have to let's call it theta star Prime + + align:start position:0% +I have to let's call it theta star Prime + + + align:start position:0% +I have to let's call it theta star Prime +I have to minimizer's that could be the + + align:start position:0% +I have to minimizer's that could be the + + + align:start position:0% +I have to minimizer's that could be the +case right I'm not saying that so key of + + align:start position:0% +case right I'm not saying that so key of + + + align:start position:0% +case right I'm not saying that so key of +L K L is 0 at the minimum that doesn't + + align:start position:0% +L K L is 0 at the minimum that doesn't + + + align:start position:0% +L K L is 0 at the minimum that doesn't +mean that I have a unique minimum right + + align:start position:0% +mean that I have a unique minimum right + + + align:start position:0% +mean that I have a unique minimum right +but it does actually what do I need to + + align:start position:0% +but it does actually what do I need to + + + align:start position:0% +but it does actually what do I need to +use to make sure that I have only one + + align:start position:0% +use to make sure that I have only one + + + align:start position:0% +use to make sure that I have only one +minimum so the definiteness is + + align:start position:0% +minimum so the definiteness is + + + align:start position:0% +minimum so the definiteness is +guaranteeing to me that the unique + + align:start position:0% +guaranteeing to me that the unique + + + align:start position:0% +guaranteeing to me that the unique +minute there's a unique piece data + + align:start position:0% +minute there's a unique piece data + + + align:start position:0% +minute there's a unique piece data +stored that minimizes it but then I need + + align:start position:0% +stored that minimizes it but then I need + + + align:start position:0% +stored that minimizes it but then I need +to make sure that there's a unique from + + align:start position:0% +to make sure that there's a unique from + + + align:start position:0% +to make sure that there's a unique from +this unique piece data star I need to go + + align:start position:0% +this unique piece data star I need to go + + + align:start position:0% +this unique piece data star I need to go +I need to make sure there's a unique + + align:start position:0% +I need to make sure there's a unique + + + align:start position:0% +I need to make sure there's a unique +data store that defines this piece to + + align:start position:0% +data store that defines this piece to + + + align:start position:0% +data store that defines this piece to +the star exactly + + align:start position:0% +the star exactly + + + align:start position:0% +the star exactly +all right so I combined definiteness and + + align:start position:0% +all right so I combined definiteness and + + + align:start position:0% +all right so I combined definiteness and +identifiability to make sure that + + align:start position:0% +identifiability to make sure that + + + align:start position:0% +identifiability to make sure that +there's a unique minimizer in this case + + align:start position:0% +there's a unique minimizer in this case + + + align:start position:0% +there's a unique minimizer in this case +cannot exist ok so basically let me + + align:start position:0% +cannot exist ok so basically let me + + + align:start position:0% +cannot exist ok so basically let me +write what I just said + + align:start position:0% +write what I just said + + + align:start position:0% +write what I just said +so definiteness that implies + + align:start position:0% +so definiteness that implies + + + align:start position:0% +so definiteness that implies +that P theta star is the unique + + align:start position:0% + + + + align:start position:0% + +minimizer of P theta maps to K L P theta + + align:start position:0% +minimizer of P theta maps to K L P theta + + + align:start position:0% +minimizer of P theta maps to K L P theta +star P theta + + align:start position:0% +star P theta + + + align:start position:0% +star P theta +alright so definiteness only guarantees + + align:start position:0% +alright so definiteness only guarantees + + + align:start position:0% +alright so definiteness only guarantees +that the parabola distribution is + + align:start position:0% +that the parabola distribution is + + + align:start position:0% +that the parabola distribution is +uniquely identified and identifiability + + align:start position:0% + + + + align:start position:0% + +implies that theta star is the unique + + align:start position:0% + + + + align:start position:0% + +minimizer of theta maps to KL P theta + + align:start position:0% +minimizer of theta maps to KL P theta + + + align:start position:0% +minimizer of theta maps to KL P theta +star P theta okay + + align:start position:0% +star P theta okay + + + align:start position:0% +star P theta okay +so I'm basically doing the composition + + align:start position:0% +so I'm basically doing the composition + + + align:start position:0% +so I'm basically doing the composition +of two injective functions the first one + + align:start position:0% +of two injective functions the first one + + + align:start position:0% +of two injective functions the first one +is the one that map's say theta to P + + align:start position:0% +is the one that map's say theta to P + + + align:start position:0% +is the one that map's say theta to P +theta and the second one is the one that + + align:start position:0% +theta and the second one is the one that + + + align:start position:0% +theta and the second one is the one that +map's P theta to the set of minimizer's + + align:start position:0% +map's P theta to the set of minimizer's + + + align:start position:0% +map's P theta to the set of minimizer's +okay agree so at least morally you + + align:start position:0% +okay agree so at least morally you + + + align:start position:0% +okay agree so at least morally you +should have agree that theta star is the + + align:start position:0% +should have agree that theta star is the + + + align:start position:0% +should have agree that theta star is the +minimizer of this thing whether it's + + align:start position:0% +minimizer of this thing whether it's + + + align:start position:0% +minimizer of this thing whether it's +unique or not you should agree that it's + + align:start position:0% +unique or not you should agree that it's + + + align:start position:0% +unique or not you should agree that it's +a good one so maybe you can think it a + + align:start position:0% +a good one so maybe you can think it a + + + align:start position:0% +a good one so maybe you can think it a +little longer on this and so thinking + + align:start position:0% +little longer on this and so thinking + + + align:start position:0% +little longer on this and so thinking +about this being the minimizer then it + + align:start position:0% +about this being the minimizer then it + + + align:start position:0% +about this being the minimizer then it +says well if I actually had a good + + align:start position:0% +says well if I actually had a good + + + align:start position:0% +says well if I actually had a good +estimate for this function I would use + + align:start position:0% +estimate for this function I would use + + + align:start position:0% +estimate for this function I would use +the strategy that I described for the + + align:start position:0% +the strategy that I described for the + + + align:start position:0% +the strategy that I described for the +toe variation which is well I don't know + + align:start position:0% +toe variation which is well I don't know + + + align:start position:0% +toe variation which is well I don't know +what this function looks like it depends + + align:start position:0% +what this function looks like it depends + + + align:start position:0% +what this function looks like it depends +on theta star but maybe I can find an + + align:start position:0% +on theta star but maybe I can find an + + + align:start position:0% +on theta star but maybe I can find an +estimator of this function that + + align:start position:0% +estimator of this function that + + + align:start position:0% +estimator of this function that +fluctuates around this function and such + + align:start position:0% +fluctuates around this function and such + + + align:start position:0% +fluctuates around this function and such +that when I minimize this estimator of + + align:start position:0% +that when I minimize this estimator of + + + align:start position:0% +that when I minimize this estimator of +the function + + align:start position:0% +the function + + + align:start position:0% +the function +I'm actually not too far okay and this + + align:start position:0% +I'm actually not too far okay and this + + + align:start position:0% +I'm actually not too far okay and this +is exactly what drives me to do this + + align:start position:0% +is exactly what drives me to do this + + + align:start position:0% +is exactly what drives me to do this +because I can actually construct an + + align:start position:0% +because I can actually construct an + + + align:start position:0% +because I can actually construct an +estimator I can actually construct an + + align:start position:0% +estimator I can actually construct an + + + align:start position:0% +estimator I can actually construct an +estimator such that this estimator is + + align:start position:0% +estimator such that this estimator is + + + align:start position:0% +estimator such that this estimator is +actually of K of the key L is actually + + align:start position:0% +actually of K of the key L is actually + + + align:start position:0% +actually of K of the key L is actually +close to the key oh all right so I + + align:start position:0% +close to the key oh all right so I + + + align:start position:0% +close to the key oh all right so I +define key L hat + + align:start position:0% +define key L hat + + + align:start position:0% +define key L hat +all right so all we did is just + + align:start position:0% +all right so all we did is just + + + align:start position:0% +all right so all we did is just +replacing expectations respect to see + + align:start position:0% +replacing expectations respect to see + + + align:start position:0% +replacing expectations respect to see +the star by averages that's what we did + + align:start position:0% +the star by averages that's what we did + + + align:start position:0% +the star by averages that's what we did +so if you're a little puzzled by this + + align:start position:0% +so if you're a little puzzled by this + + + align:start position:0% +so if you're a little puzzled by this +arrow that's all it says replace this + + align:start position:0% +arrow that's all it says replace this + + + align:start position:0% +arrow that's all it says replace this +guy by this guy there's no mathematical + + align:start position:0% +guy by this guy there's no mathematical + + + align:start position:0% +guy by this guy there's no mathematical +meaning it just means just replace it by + + align:start position:0% +meaning it just means just replace it by + + + align:start position:0% +meaning it just means just replace it by +and now that actually gives tells me how + + align:start position:0% +and now that actually gives tells me how + + + align:start position:0% +and now that actually gives tells me how +to get my estimator it just says well my + + align:start position:0% +to get my estimator it just says well my + + + align:start position:0% +to get my estimator it just says well my +steamy Tarkio hat is equal to some + + align:start position:0% +steamy Tarkio hat is equal to some + + + align:start position:0% +steamy Tarkio hat is equal to some +constant which I don't know I mean it + + align:start position:0% +constant which I don't know I mean it + + + align:start position:0% +constant which I don't know I mean it +certainly depends on theta star but I + + align:start position:0% +certainly depends on theta star but I + + + align:start position:0% +certainly depends on theta star but I +won't care about it when I'm trying to + + align:start position:0% +won't care about it when I'm trying to + + + align:start position:0% +won't care about it when I'm trying to +minimize minus 1 over n sum from I to 1 + + align:start position:0% +minimize minus 1 over n sum from I to 1 + + + align:start position:0% +minimize minus 1 over n sum from I to 1 +to n log PF theta say of X right so here + + align:start position:0% +to n log PF theta say of X right so here + + + align:start position:0% +to n log PF theta say of X right so here +I'm writing it with the density you have + + align:start position:0% +I'm writing it with the density you have + + + align:start position:0% +I'm writing it with the density you have +it with the PMF on the slides and so you + + align:start position:0% +it with the PMF on the slides and so you + + + align:start position:0% +it with the PMF on the slides and so you +have the two versions in front of you + + align:start position:0% +have the two versions in front of you + + + align:start position:0% +have the two versions in front of you +okay I'm sorry I forgot the X I now + + align:start position:0% +okay I'm sorry I forgot the X I now + + + align:start position:0% +okay I'm sorry I forgot the X I now +clearly this function I know how to + + align:start position:0% +clearly this function I know how to + + + align:start position:0% +clearly this function I know how to +compute if you give me a theta since I + + align:start position:0% +compute if you give me a theta since I + + + align:start position:0% +compute if you give me a theta since I +know the fam the the the form of the + + align:start position:0% +know the fam the the the form of the + + + align:start position:0% +know the fam the the the form of the +density as theta for each theater that + + align:start position:0% +density as theta for each theater that + + + align:start position:0% +density as theta for each theater that +you give me I can actually compute this + + align:start position:0% +you give me I can actually compute this + + + align:start position:0% +you give me I can actually compute this +quantity right this I don't know but I + + align:start position:0% +quantity right this I don't know but I + + + align:start position:0% +quantity right this I don't know but I +don't care because I'm just shifting the + + align:start position:0% +don't care because I'm just shifting the + + + align:start position:0% +don't care because I'm just shifting the +value of the function I'm trying to + + align:start position:0% +value of the function I'm trying to + + + align:start position:0% +value of the function I'm trying to +minimize the set of minimizer's it's not + + align:start position:0% +minimize the set of minimizer's it's not + + + align:start position:0% +minimize the set of minimizer's it's not +going to change right so now this is my + + align:start position:0% +going to change right so now this is my + + + align:start position:0% +going to change right so now this is my +estimation strategy minimize in theta + + align:start position:0% +estimation strategy minimize in theta + + + align:start position:0% +estimation strategy minimize in theta +kiyo hat p theta star t theta okay + + align:start position:0% +kiyo hat p theta star t theta okay + + + align:start position:0% +kiyo hat p theta star t theta okay +so now let's just make sure that we all + + align:start position:0% +so now let's just make sure that we all + + + align:start position:0% +so now let's just make sure that we all +agree that so what we want is the + + align:start position:0% +agree that so what we want is the + + + align:start position:0% +agree that so what we want is the +argument of the minimum right orgman + + align:start position:0% +argument of the minimum right orgman + + + align:start position:0% +argument of the minimum right orgman +means the theta that minimizes this guy + + align:start position:0% +means the theta that minimizes this guy + + + align:start position:0% +means the theta that minimizes this guy +well and finding the value of the + + align:start position:0% +well and finding the value of the + + + align:start position:0% +well and finding the value of the +minimum okay so I'm trying to find the + + align:start position:0% +minimum okay so I'm trying to find the + + + align:start position:0% +minimum okay so I'm trying to find the +argument of this thing well this is + + align:start position:0% +argument of this thing well this is + + + align:start position:0% +argument of this thing well this is +equivalent to finding the orgman of say + + align:start position:0% +equivalent to finding the orgman of say + + + align:start position:0% +equivalent to finding the orgman of say +a constant minus 1 over n sum from i who + + align:start position:0% +a constant minus 1 over n sum from i who + + + align:start position:0% +a constant minus 1 over n sum from i who +want to end the vlog + + align:start position:0% +want to end the vlog + + + align:start position:0% +want to end the vlog +that's theta X I okay so that's just I + + align:start position:0% + + + + align:start position:0% + +think it likes me okay so so that's + + align:start position:0% +think it likes me okay so so that's + + + align:start position:0% +think it likes me okay so so that's +minimizing this average right I just + + align:start position:0% +minimizing this average right I just + + + align:start position:0% +minimizing this average right I just +plugged in the definition of kale hat + + align:start position:0% +plugged in the definition of kale hat + + + align:start position:0% +plugged in the definition of kale hat +now I claim that taking the arming of a + + align:start position:0% +now I claim that taking the arming of a + + + align:start position:0% +now I claim that taking the arming of a +constant or the argument plus a function + + align:start position:0% +constant or the argument plus a function + + + align:start position:0% +constant or the argument plus a function +or the argument of the function is the + + align:start position:0% +or the argument of the function is the + + + align:start position:0% +or the argument of the function is the +same thing is anybody not comfortable + + align:start position:0% +same thing is anybody not comfortable + + + align:start position:0% +same thing is anybody not comfortable +with this idea okay so this is the same + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +by the way this I should probably switch + + align:start position:0% +by the way this I should probably switch + + + align:start position:0% +by the way this I should probably switch +to the next slide because I'm writing + + align:start position:0% +to the next slide because I'm writing + + + align:start position:0% +to the next slide because I'm writing +the same thing but better and it's with + + align:start position:0% +the same thing but better and it's with + + + align:start position:0% +the same thing but better and it's with +a PMF rather than as a PDF + + align:start position:0% +a PMF rather than as a PDF + + + align:start position:0% +a PMF rather than as a PDF +okay now argument of the minimum is the + + align:start position:0% +okay now argument of the minimum is the + + + align:start position:0% +okay now argument of the minimum is the +same about max sorry argument of the + + align:start position:0% +same about max sorry argument of the + + + align:start position:0% +same about max sorry argument of the +negative thing is the same as our max + + align:start position:0% +negative thing is the same as our max + + + align:start position:0% +negative thing is the same as our max +without the negative right our max over + + align:start position:0% +without the negative right our max over + + + align:start position:0% +without the negative right our max over +theta of 1 over N sum from 1 equal to I + + align:start position:0% +theta of 1 over N sum from 1 equal to I + + + align:start position:0% +theta of 1 over N sum from 1 equal to I +equal 1 to n log F theta of X I + + align:start position:0% + + + + align:start position:0% + +taking the orgmen of the average or the + + align:start position:0% +taking the orgmen of the average or the + + + align:start position:0% +taking the orgmen of the average or the +army of the some again it's not gonna + + align:start position:0% +army of the some again it's not gonna + + + align:start position:0% +army of the some again it's not gonna +make much difference + + align:start position:0% +make much difference + + + align:start position:0% +make much difference +just adding constants or multiplying by + + align:start position:0% +just adding constants or multiplying by + + + align:start position:0% +just adding constants or multiplying by +constants does not change the argument + + align:start position:0% +constants does not change the argument + + + align:start position:0% +constants does not change the argument +or the arc max now I have the sum of + + align:start position:0% +or the arc max now I have the sum of + + + align:start position:0% +or the arc max now I have the sum of +logs which is the log of the product + + align:start position:0% + + + + align:start position:0% + +okay that's the arc max of the log of f + + align:start position:0% +okay that's the arc max of the log of f + + + align:start position:0% +okay that's the arc max of the log of f +theta of X 1 times F theta of X 2 F + + align:start position:0% +theta of X 1 times F theta of X 2 F + + + align:start position:0% +theta of X 1 times F theta of X 2 F +theta of X n but the log is a function + + align:start position:0% +theta of X n but the log is a function + + + align:start position:0% +theta of X n but the log is a function +that's increasing so maximizing log of a + + align:start position:0% +that's increasing so maximizing log of a + + + align:start position:0% +that's increasing so maximizing log of a +function or maximizing the function + + align:start position:0% +function or maximizing the function + + + align:start position:0% +function or maximizing the function +itself is the same thing the value is + + align:start position:0% +itself is the same thing the value is + + + align:start position:0% +itself is the same thing the value is +going to change but the arc max is not + + align:start position:0% +going to change but the arc max is not + + + align:start position:0% +going to change but the arc max is not +going to change everybody agrees with + + align:start position:0% +going to change everybody agrees with + + + align:start position:0% +going to change everybody agrees with +this so this is equivalent to arc max + + align:start position:0% +this so this is equivalent to arc max + + + align:start position:0% +this so this is equivalent to arc max +over theta of Pi from 1 to N of F theta + + align:start position:0% +over theta of Pi from 1 to N of F theta + + + align:start position:0% +over theta of Pi from 1 to N of F theta +X I and that's because X maps to log X + + align:start position:0% +X I and that's because X maps to log X + + + align:start position:0% +X I and that's because X maps to log X +is increasing okay so now I've gone from + + align:start position:0% +is increasing okay so now I've gone from + + + align:start position:0% +is increasing okay so now I've gone from +minimizing the KL to minimizing the + + align:start position:0% +minimizing the KL to minimizing the + + + align:start position:0% +minimizing the KL to minimizing the +estimate of the KO to maximizing this + + align:start position:0% +estimate of the KO to maximizing this + + + align:start position:0% +estimate of the KO to maximizing this +product well this chapter is called + + align:start position:0% +product well this chapter is called + + + align:start position:0% +product well this chapter is called +maximum likelihood estimation that's the + + align:start position:0% +maximum likelihood estimation that's the + + + align:start position:0% +maximum likelihood estimation that's the +maximum comes from the fact that our + + align:start position:0% +maximum comes from the fact that our + + + align:start position:0% +maximum comes from the fact that our +original idea was to minimize the + + align:start position:0% +original idea was to minimize the + + + align:start position:0% +original idea was to minimize the +negative of a function so that's why + + align:start position:0% +negative of a function so that's why + + + align:start position:0% +negative of a function so that's why +it's maximum likelihood and this + + align:start position:0% +it's maximum likelihood and this + + + align:start position:0% +it's maximum likelihood and this +function here is called the likelihood + + align:start position:0% +function here is called the likelihood + + + align:start position:0% +function here is called the likelihood +all right this function is really just + + align:start position:0% +all right this function is really just + + + align:start position:0% +all right this function is really just +telling me they call it likelihood + + align:start position:0% +telling me they call it likelihood + + + align:start position:0% +telling me they call it likelihood +because it's some measure of how likely + + align:start position:0% +because it's some measure of how likely + + + align:start position:0% +because it's some measure of how likely +it is that data was the parameter that + + align:start position:0% +it is that data was the parameter that + + + align:start position:0% +it is that data was the parameter that +generated the data okay so let's go to + + align:start position:0% +generated the data okay so let's go to + + + align:start position:0% +generated the data okay so let's go to +the well we'll go to the formal + + align:start position:0% +the well we'll go to the formal + + + align:start position:0% +the well we'll go to the formal +definition in a second but actually + + align:start position:0% +definition in a second but actually + + + align:start position:0% +definition in a second but actually +energies could give you an intuition as + + align:start position:0% +energies could give you an intuition as + + + align:start position:0% +energies could give you an intuition as +to why this is the distribution of the + + align:start position:0% +to why this is the distribution of the + + + align:start position:0% +to why this is the distribution of the +day + + align:start position:0% +day + + + align:start position:0% +day +okay-y this is the likelihood sorry why + + align:start position:0% +okay-y this is the likelihood sorry why + + + align:start position:0% +okay-y this is the likelihood sorry why +is this making sense as a measure of + + align:start position:0% +is this making sense as a measure of + + + align:start position:0% +is this making sense as a measure of +likelihood let's now think for + + align:start position:0% +likelihood let's now think for + + + align:start position:0% +likelihood let's now think for +simplicity of the following model so I + + align:start position:0% +simplicity of the following model so I + + + align:start position:0% +simplicity of the following model so I +have I'm on the real line and I look at + + align:start position:0% +have I'm on the real line and I look at + + + align:start position:0% +have I'm on the real line and I look at +n say theta 1 for theta in the real do + + align:start position:0% +n say theta 1 for theta in the real do + + + align:start position:0% +n say theta 1 for theta in the real do +you see that okay probably you don't + + align:start position:0% +you see that okay probably you don't + + + align:start position:0% +you see that okay probably you don't +care ok so ok let's look at a simple + + align:start position:0% +care ok so ok let's look at a simple + + + align:start position:0% +care ok so ok let's look at a simple +example so here's the model as I said + + align:start position:0% +example so here's the model as I said + + + align:start position:0% +example so here's the model as I said +we're looking at observations on the + + align:start position:0% +we're looking at observations on the + + + align:start position:0% +we're looking at observations on the +real line and they're distributed + + align:start position:0% +real line and they're distributed + + + align:start position:0% +real line and they're distributed +according to some n 0 sorry theta 1 so I + + align:start position:0% +according to some n 0 sorry theta 1 so I + + + align:start position:0% +according to some n 0 sorry theta 1 so I +don't care about the variance I know + + align:start position:0% +don't care about the variance I know + + + align:start position:0% +don't care about the variance I know +it's 1 and it's indexed by theta in the + + align:start position:0% +it's 1 and it's indexed by theta in the + + + align:start position:0% +it's 1 and it's indexed by theta in the +real line ok so this is the only thing I + + align:start position:0% +real line ok so this is the only thing I + + + align:start position:0% +real line ok so this is the only thing I +need to figure out is what is the + + align:start position:0% +need to figure out is what is the + + + align:start position:0% +need to figure out is what is the +density what is the mean of those guys + + align:start position:0% +density what is the mean of those guys + + + align:start position:0% +density what is the mean of those guys +ok now I have this n observation then if + + align:start position:0% +ok now I have this n observation then if + + + align:start position:0% +ok now I have this n observation then if +you actually remember from your + + align:start position:0% +you actually remember from your + + + align:start position:0% +you actually remember from your +probability class you are you familiar + + align:start position:0% +probability class you are you familiar + + + align:start position:0% +probability class you are you familiar +with the concept of joint density right + + align:start position:0% +with the concept of joint density right + + + align:start position:0% +with the concept of joint density right +if I have multivariate observations the + + align:start position:0% +if I have multivariate observations the + + + align:start position:0% +if I have multivariate observations the +joint density of independent random + + align:start position:0% +joint density of independent random + + + align:start position:0% +joint density of independent random +variables is just a product of their + + align:start position:0% +variables is just a product of their + + + align:start position:0% +variables is just a product of their +individual densities all right so really + + align:start position:0% +individual densities all right so really + + + align:start position:0% +individual densities all right so really +when I look at the product from one I + + align:start position:0% +when I look at the product from one I + + + align:start position:0% +when I look at the product from one I +could want to end of F theta of X I this + + align:start position:0% +could want to end of F theta of X I this + + + align:start position:0% +could want to end of F theta of X I this +is really the joint density of the + + align:start position:0% +is really the joint density of the + + + align:start position:0% +is really the joint density of the +vector well let me not use the word + + align:start position:0% +vector well let me not use the word + + + align:start position:0% +vector well let me not use the word +vector of X 1 X n ok so if I take the + + align:start position:0% +vector of X 1 X n ok so if I take the + + + align:start position:0% +vector of X 1 X n ok so if I take the +product of densities it's still a + + align:start position:0% +product of densities it's still a + + + align:start position:0% +product of densities it's still a +density and it's actually the but this + + align:start position:0% +density and it's actually the but this + + + align:start position:0% +density and it's actually the but this +time on the R to the N ok and so now + + align:start position:0% +time on the R to the N ok and so now + + + align:start position:0% +time on the R to the N ok and so now +what this thing is telling me so think + + align:start position:0% +what this thing is telling me so think + + + align:start position:0% +what this thing is telling me so think +of it in r2 right so this is the joint + + align:start position:0% +of it in r2 right so this is the joint + + + align:start position:0% +of it in r2 right so this is the joint +density of two Gaussian so it's + + align:start position:0% +density of two Gaussian so it's + + + align:start position:0% +density of two Gaussian so it's +something that looks like some + + align:start position:0% +something that looks like some + + + align:start position:0% +something that looks like some +bell-shaped curve than two dimensions + + align:start position:0% +bell-shaped curve than two dimensions + + + align:start position:0% +bell-shaped curve than two dimensions +and it's centered at the value + + align:start position:0% +and it's centered at the value + + + align:start position:0% +and it's centered at the value +theta theta okay they both have them in + + align:start position:0% +theta theta okay they both have them in + + + align:start position:0% +theta theta okay they both have them in +data so let's assume for one second it's + + align:start position:0% +data so let's assume for one second it's + + + align:start position:0% +data so let's assume for one second it's +gonna be hard for me to make pictures in + + align:start position:0% +gonna be hard for me to make pictures in + + + align:start position:0% +gonna be hard for me to make pictures in +n dimensions actually already in two + + align:start position:0% +n dimensions actually already in two + + + align:start position:0% +n dimensions actually already in two +dimensions I can promise you that it's + + align:start position:0% +dimensions I can promise you that it's + + + align:start position:0% +dimensions I can promise you that it's +not very easy so I'm actually just gonna + + align:start position:0% +not very easy so I'm actually just gonna + + + align:start position:0% +not very easy so I'm actually just gonna +assume that n is equal to one for the + + align:start position:0% +assume that n is equal to one for the + + + align:start position:0% +assume that n is equal to one for the +sake of illustration okay so now I have + + align:start position:0% +sake of illustration okay so now I have + + + align:start position:0% +sake of illustration okay so now I have +this data and now I have one observation + + align:start position:0% +this data and now I have one observation + + + align:start position:0% +this data and now I have one observation +okay and I know that the F theta looks + + align:start position:0% +okay and I know that the F theta looks + + + align:start position:0% +okay and I know that the F theta looks +like this and what I'm doing is I'm + + align:start position:0% +like this and what I'm doing is I'm + + + align:start position:0% +like this and what I'm doing is I'm +actually looking at the value of F X + + align:start position:0% +actually looking at the value of F X + + + align:start position:0% +actually looking at the value of F X +theta at my observation go it x1 now + + align:start position:0% +theta at my observation go it x1 now + + + align:start position:0% +theta at my observation go it x1 now +when I'm my principal tells me just find + + align:start position:0% +when I'm my principal tells me just find + + + align:start position:0% +when I'm my principal tells me just find +the theta that makes this guy the most + + align:start position:0% +the theta that makes this guy the most + + + align:start position:0% +the theta that makes this guy the most +likely what is the likelihood of my x1 + + align:start position:0% +likely what is the likelihood of my x1 + + + align:start position:0% +likely what is the likelihood of my x1 +well it's just the value of the function + + align:start position:0% +well it's just the value of the function + + + align:start position:0% +well it's just the value of the function +right that's this value here and if I + + align:start position:0% +right that's this value here and if I + + + align:start position:0% +right that's this value here and if I +wanted to make to find the most likely + + align:start position:0% +wanted to make to find the most likely + + + align:start position:0% +wanted to make to find the most likely +theta that had generated this x1 what I + + align:start position:0% +theta that had generated this x1 what I + + + align:start position:0% +theta that had generated this x1 what I +would need to do is to shift this thing + + align:start position:0% +would need to do is to shift this thing + + + align:start position:0% +would need to do is to shift this thing +and put it here + + align:start position:0% +and put it here + + + align:start position:0% +and put it here +okay and so my estimate make maximum + + align:start position:0% +okay and so my estimate make maximum + + + align:start position:0% +okay and so my estimate make maximum +likelihood estimator here would be X + + align:start position:0% +likelihood estimator here would be X + + + align:start position:0% +likelihood estimator here would be X +theta is equal to x1 okay that would be + + align:start position:0% +theta is equal to x1 okay that would be + + + align:start position:0% +theta is equal to x1 okay that would be +just the observation because you know if + + align:start position:0% +just the observation because you know if + + + align:start position:0% +just the observation because you know if +I have only in one observation what else + + align:start position:0% +I have only in one observation what else + + + align:start position:0% +I have only in one observation what else +am I gonna do okay and so it sort of + + align:start position:0% +am I gonna do okay and so it sort of + + + align:start position:0% +am I gonna do okay and so it sort of +makes sense and if you have more + + align:start position:0% +makes sense and if you have more + + + align:start position:0% +makes sense and if you have more +observations you can think of it this + + align:start position:0% +observations you can think of it this + + + align:start position:0% +observations you can think of it this +way as if you had more observations so + + align:start position:0% +way as if you had more observations so + + + align:start position:0% +way as if you had more observations so +now I have say key observations or n + + align:start position:0% +now I have say key observations or n + + + align:start position:0% +now I have say key observations or n +observations and what I do is that I + + align:start position:0% +observations and what I do is that I + + + align:start position:0% +observations and what I do is that I +look at the value for each of these guys + + align:start position:0% +look at the value for each of these guys + + + align:start position:0% +look at the value for each of these guys +right so this value this value this + + align:start position:0% +right so this value this value this + + + align:start position:0% +right so this value this value this +value this value I take your product and + + align:start position:0% +value this value I take your product and + + + align:start position:0% +value this value I take your product and +I make this thing large okay why do I + + align:start position:0% +I make this thing large okay why do I + + + align:start position:0% +I make this thing large okay why do I +take the product well because I'm trying + + align:start position:0% +take the product well because I'm trying + + + align:start position:0% +take the product well because I'm trying +to maximize their value altogether and I + + align:start position:0% +to maximize their value altogether and I + + + align:start position:0% +to maximize their value altogether and I +need to just turn it into one number + + align:start position:0% +need to just turn it into one number + + + align:start position:0% +need to just turn it into one number +that I can maximize and taking the + + align:start position:0% +that I can maximize and taking the + + + align:start position:0% +that I can maximize and taking the +product is the natural way of doing it + + align:start position:0% +product is the natural way of doing it + + + align:start position:0% +product is the natural way of doing it +either by motivating it by the KL + + align:start position:0% +either by motivating it by the KL + + + align:start position:0% +either by motivating it by the KL +principle or motivating it by maximizing + + align:start position:0% +principle or motivating it by maximizing + + + align:start position:0% +principle or motivating it by maximizing +the joint density rather than just + + align:start position:0% +the joint density rather than just + + + align:start position:0% +the joint density rather than just +maximizing anything okay so that's + + align:start position:0% +maximizing anything okay so that's + + + align:start position:0% +maximizing anything okay so that's +that's why you know visually this is the + + align:start position:0% +that's why you know visually this is the + + + align:start position:0% +that's why you know visually this is the +maximum likelihood it just says that if + + align:start position:0% +maximum likelihood it just says that if + + + align:start position:0% +maximum likelihood it just says that if +my observations are here then this guy + + align:start position:0% +my observations are here then this guy + + + align:start position:0% +my observations are here then this guy +this mean data is more likely than this + + align:start position:0% +this mean data is more likely than this + + + align:start position:0% +this mean data is more likely than this +guy + + align:start position:0% +guy + + + align:start position:0% +guy +because now if I look at the value + + align:start position:0% +because now if I look at the value + + + align:start position:0% +because now if I look at the value +of the function for these guys if I look + + align:start position:0% +of the function for these guys if I look + + + align:start position:0% +of the function for these guys if I look +at data being this thing then this is a + + align:start position:0% +at data being this thing then this is a + + + align:start position:0% +at data being this thing then this is a +very small value very small value very + + align:start position:0% +very small value very small value very + + + align:start position:0% +very small value very small value very +small value very small value everything + + align:start position:0% +small value very small value everything + + + align:start position:0% +small value very small value everything +gets a super small value right that's + + align:start position:0% +gets a super small value right that's + + + align:start position:0% +gets a super small value right that's +just the value that it gets in the tail + + align:start position:0% +just the value that it gets in the tail + + + align:start position:0% +just the value that it gets in the tail +here which is very close to zero but as + + align:start position:0% +here which is very close to zero but as + + + align:start position:0% +here which is very close to zero but as +soon as I start covering all my points + + align:start position:0% +soon as I start covering all my points + + + align:start position:0% +soon as I start covering all my points +with my bell-shaped curve then all the + + align:start position:0% +with my bell-shaped curve then all the + + + align:start position:0% +with my bell-shaped curve then all the +values go up alright so I just want to + + align:start position:0% +values go up alright so I just want to + + + align:start position:0% +values go up alright so I just want to +make a short break into statistics and + + align:start position:0% +make a short break into statistics and + + + align:start position:0% +make a short break into statistics and +just make sure that the maximum likely a + + align:start position:0% +just make sure that the maximum likely a + + + align:start position:0% +just make sure that the maximum likely a +principal involves maximizing a function + + align:start position:0% +principal involves maximizing a function + + + align:start position:0% +principal involves maximizing a function +all right so I just want to make sure + + align:start position:0% +all right so I just want to make sure + + + align:start position:0% +all right so I just want to make sure +that we're all in part about how do we + + align:start position:0% +that we're all in part about how do we + + + align:start position:0% +that we're all in part about how do we +maximize functions okay + + align:start position:0% +maximize functions okay + + + align:start position:0% +maximize functions okay +in most instances is going to be a + + align:start position:0% +in most instances is going to be a + + + align:start position:0% +in most instances is going to be a +one-dimensional function because theta + + align:start position:0% +one-dimensional function because theta + + + align:start position:0% +one-dimensional function because theta +is going to be a one dimensional + + align:start position:0% +is going to be a one dimensional + + + align:start position:0% +is going to be a one dimensional +parameter like here it's the real line + + align:start position:0% +parameter like here it's the real line + + + align:start position:0% +parameter like here it's the real line +so it's gonna be easy in some cases it + + align:start position:0% +so it's gonna be easy in some cases it + + + align:start position:0% +so it's gonna be easy in some cases it +might be a multivariate function and + + align:start position:0% +might be a multivariate function and + + + align:start position:0% +might be a multivariate function and +might be more complicated okay so let's + + align:start position:0% +might be more complicated okay so let's + + + align:start position:0% +might be more complicated okay so let's +just make this interlude so the first + + align:start position:0% +just make this interlude so the first + + + align:start position:0% +just make this interlude so the first +thing I want you to notice is that if + + align:start position:0% +thing I want you to notice is that if + + + align:start position:0% +thing I want you to notice is that if +you open any book on what's called + + align:start position:0% +you open any book on what's called + + + align:start position:0% +you open any book on what's called +optimization which basically is the + + align:start position:0% +optimization which basically is the + + + align:start position:0% +optimization which basically is the +science behind optimizing functions you + + align:start position:0% +science behind optimizing functions you + + + align:start position:0% +science behind optimizing functions you +will talk mostly I mean I'd say 99.9% of + + align:start position:0% +will talk mostly I mean I'd say 99.9% of + + + align:start position:0% +will talk mostly I mean I'd say 99.9% of +the cases will talk about minimizing + + align:start position:0% +the cases will talk about minimizing + + + align:start position:0% +the cases will talk about minimizing +functions but it doesn't matter because + + align:start position:0% +functions but it doesn't matter because + + + align:start position:0% +functions but it doesn't matter because +you can just flip the function and you + + align:start position:0% +you can just flip the function and you + + + align:start position:0% +you can just flip the function and you +just put a minus sign and minimizing H + + align:start position:0% +just put a minus sign and minimizing H + + + align:start position:0% +just put a minus sign and minimizing H +is the same as maximizing minus H and + + align:start position:0% +is the same as maximizing minus H and + + + align:start position:0% +is the same as maximizing minus H and +the opposite okay + + align:start position:0% +the opposite okay + + + align:start position:0% +the opposite okay +so for this class since we're only going + + align:start position:0% +so for this class since we're only going + + + align:start position:0% +so for this class since we're only going +to talk about maximum likelihood + + align:start position:0% +to talk about maximum likelihood + + + align:start position:0% +to talk about maximum likelihood +estimation we will talk about maximizing + + align:start position:0% +estimation we will talk about maximizing + + + align:start position:0% +estimation we will talk about maximizing +functions but don't be lost if you + + align:start position:0% +functions but don't be lost if you + + + align:start position:0% +functions but don't be lost if you +decide certainly to open a book on + + align:start position:0% +decide certainly to open a book on + + + align:start position:0% +decide certainly to open a book on +optimization and find only something + + align:start position:0% +optimization and find only something + + + align:start position:0% +optimization and find only something +about minimizing functions okay so + + align:start position:0% +about minimizing functions okay so + + + align:start position:0% +about minimizing functions okay so +maximizing and our Batory + + align:start position:0% +maximizing and our Batory + + + align:start position:0% +maximizing and our Batory +function it can actually be fairly + + align:start position:0% +function it can actually be fairly + + + align:start position:0% +function it can actually be fairly +difficult if I give you a function that + + align:start position:0% +difficult if I give you a function that + + + align:start position:0% +difficult if I give you a function that +has this weird shape right let's think + + align:start position:0% +has this weird shape right let's think + + + align:start position:0% +has this weird shape right let's think +of this polynomial for example and I + + align:start position:0% +of this polynomial for example and I + + + align:start position:0% +of this polynomial for example and I +wanted to find the maximum how would you + + align:start position:0% +wanted to find the maximum how would you + + + align:start position:0% +wanted to find the maximum how would you +do it so what is the thing you've + + align:start position:0% +do it so what is the thing you've + + + align:start position:0% +do it so what is the thing you've +learned in calculus on how to maximize a + + align:start position:0% +learned in calculus on how to maximize a + + + align:start position:0% +learned in calculus on how to maximize a +function to set the derivative equal to + + align:start position:0% +function to set the derivative equal to + + + align:start position:0% +function to set the derivative equal to +zero maybe you want to check the second + + align:start position:0% +zero maybe you want to check the second + + + align:start position:0% +zero maybe you want to check the second +derivative to make sure it's a maximum + + align:start position:0% +derivative to make sure it's a maximum + + + align:start position:0% +derivative to make sure it's a maximum +and not a minimum but the thing is this + + align:start position:0% +and not a minimum but the thing is this + + + align:start position:0% +and not a minimum but the thing is this +is only guaranteeing to you that you + + align:start position:0% +is only guaranteeing to you that you + + + align:start position:0% +is only guaranteeing to you that you +have a local one right so if I do it for + + align:start position:0% +have a local one right so if I do it for + + + align:start position:0% +have a local one right so if I do it for +this function for example then this guy + + align:start position:0% +this function for example then this guy + + + align:start position:0% +this function for example then this guy +is going to satisfy this criterion this + + align:start position:0% +is going to satisfy this criterion this + + + align:start position:0% +is going to satisfy this criterion this +guy is gonna satisfy this criterion this + + align:start position:0% +guy is gonna satisfy this criterion this + + + align:start position:0% +guy is gonna satisfy this criterion this +guy is going to satisfy this criterion + + align:start position:0% +guy is going to satisfy this criterion + + + align:start position:0% +guy is going to satisfy this criterion +this guy here and this guy satisfies the + + align:start position:0% +this guy here and this guy satisfies the + + + align:start position:0% +this guy here and this guy satisfies the +criterion but + + align:start position:0% +criterion but + + + align:start position:0% +criterion but +the second derivative one okay so I have + + align:start position:0% +the second derivative one okay so I have + + + align:start position:0% +the second derivative one okay so I have +a lot of candidates and if my function + + align:start position:0% +a lot of candidates and if my function + + + align:start position:0% +a lot of candidates and if my function +is can be really anything it's going to + + align:start position:0% +is can be really anything it's going to + + + align:start position:0% +is can be really anything it's going to +be difficult whether it's analytically + + align:start position:0% +be difficult whether it's analytically + + + align:start position:0% +be difficult whether it's analytically +by taking derivatives and setting them + + align:start position:0% +by taking derivatives and setting them + + + align:start position:0% +by taking derivatives and setting them +to zero or trying to find some + + align:start position:0% +to zero or trying to find some + + + align:start position:0% +to zero or trying to find some +algorithms to do this because if my + + align:start position:0% +algorithms to do this because if my + + + align:start position:0% +algorithms to do this because if my +function is very jittery then my + + align:start position:0% +function is very jittery then my + + + align:start position:0% +function is very jittery then my +algorithm basically has to check all + + align:start position:0% +algorithm basically has to check all + + + align:start position:0% +algorithm basically has to check all +candidates and if there's a lot of them + + align:start position:0% +candidates and if there's a lot of them + + + align:start position:0% +candidates and if there's a lot of them +and might take forever okay so this is + + align:start position:0% +and might take forever okay so this is + + + align:start position:0% +and might take forever okay so this is +you know I have only one two three four + + align:start position:0% +you know I have only one two three four + + + align:start position:0% +you know I have only one two three four +five candidates to check but in practice + + align:start position:0% +five candidates to check but in practice + + + align:start position:0% +five candidates to check but in practice +you might have a million of them to + + align:start position:0% +you might have a million of them to + + + align:start position:0% +you might have a million of them to +check and that might take forever + + align:start position:0% +check and that might take forever + + + align:start position:0% +check and that might take forever +okay so what's nice about statistical + + align:start position:0% +okay so what's nice about statistical + + + align:start position:0% +okay so what's nice about statistical +models and one of the thing that makes + + align:start position:0% +models and one of the thing that makes + + + align:start position:0% +models and one of the thing that makes +all these models particularly you know + + align:start position:0% +all these models particularly you know + + + align:start position:0% +all these models particularly you know +robust and that we still talk about them + + align:start position:0% +robust and that we still talk about them + + + align:start position:0% +robust and that we still talk about them +a hundred years after they've been + + align:start position:0% +a hundred years after they've been + + + align:start position:0% +a hundred years after they've been +introduced is that the functions that + + align:start position:0% +introduced is that the functions that + + + align:start position:0% +introduced is that the functions that +the likelihoods that they lead for us to + + align:start position:0% +the likelihoods that they lead for us to + + + align:start position:0% +the likelihoods that they lead for us to +maximize are actually very simple and + + align:start position:0% +maximize are actually very simple and + + + align:start position:0% +maximize are actually very simple and +they all share a nice property which is + + align:start position:0% +they all share a nice property which is + + + align:start position:0% +they all share a nice property which is +that of being concave all right so what + + align:start position:0% +that of being concave all right so what + + + align:start position:0% +that of being concave all right so what +is a concave function well by definition + + align:start position:0% +is a concave function well by definition + + + align:start position:0% +is a concave function well by definition +is just a function for which if let's + + align:start position:0% +is just a function for which if let's + + + align:start position:0% +is just a function for which if let's +think of it as being twice + + align:start position:0% +think of it as being twice + + + align:start position:0% +think of it as being twice +differentiable you can define functions + + align:start position:0% +differentiable you can define functions + + + align:start position:0% +differentiable you can define functions +that are not differentiable as being + + align:start position:0% +that are not differentiable as being + + + align:start position:0% +that are not differentiable as being +concave but let's think about it as + + align:start position:0% +concave but let's think about it as + + + align:start position:0% +concave but let's think about it as +having a second derivative and so if you + + align:start position:0% +having a second derivative and so if you + + + align:start position:0% +having a second derivative and so if you +look at the function that has the second + + align:start position:0% +look at the function that has the second + + + align:start position:0% +look at the function that has the second +derivative concave is are the functions + + align:start position:0% +derivative concave is are the functions + + + align:start position:0% +derivative concave is are the functions +they have their second derivative that's + + align:start position:0% +they have their second derivative that's + + + align:start position:0% +they have their second derivative that's +equal that's negative everywhere not + + align:start position:0% +equal that's negative everywhere not + + + align:start position:0% +equal that's negative everywhere not +just at the maximum everywhere okay and + + align:start position:0% +just at the maximum everywhere okay and + + + align:start position:0% +just at the maximum everywhere okay and +so if strictly concave if this second + + align:start position:0% +so if strictly concave if this second + + + align:start position:0% +so if strictly concave if this second +derivative actually strictly less than + + align:start position:0% +derivative actually strictly less than + + + align:start position:0% +derivative actually strictly less than +zero okay so in particularly if I think + + align:start position:0% +zero okay so in particularly if I think + + + align:start position:0% +zero okay so in particularly if I think +of a linear function y is equal to X + + align:start position:0% +of a linear function y is equal to X + + + align:start position:0% +of a linear function y is equal to X +then this sunk this function has its + + align:start position:0% +then this sunk this function has its + + + align:start position:0% +then this sunk this function has its +second derivative which is equal to zero + + align:start position:0% +second derivative which is equal to zero + + + align:start position:0% +second derivative which is equal to zero +okay so it is concave but it's not + + align:start position:0% +okay so it is concave but it's not + + + align:start position:0% +okay so it is concave but it's not +strictly concave okay now if I look at + + align:start position:0% +strictly concave okay now if I look at + + + align:start position:0% +strictly concave okay now if I look at +the function which is negative x squared + + align:start position:0% +the function which is negative x squared + + + align:start position:0% +the function which is negative x squared +what is its second derivative minus two + + align:start position:0% +what is its second derivative minus two + + + align:start position:0% +what is its second derivative minus two +so it's strictly negative everywhere + + align:start position:0% +so it's strictly negative everywhere + + + align:start position:0% +so it's strictly negative everywhere +okay so actually this is a pretty + + align:start position:0% +okay so actually this is a pretty + + + align:start position:0% +okay so actually this is a pretty +canonical example of canonical of trig a + + align:start position:0% +canonical example of canonical of trig a + + + align:start position:0% +canonical example of canonical of trig a +concave function if you want to think of + + align:start position:0% +concave function if you want to think of + + + align:start position:0% +concave function if you want to think of +a picture of a strictly concave function + + align:start position:0% +a picture of a strictly concave function + + + align:start position:0% +a picture of a strictly concave function +think of negative x square so parabola + + align:start position:0% +think of negative x square so parabola + + + align:start position:0% +think of negative x square so parabola +pointing towards putting downwards okay + + align:start position:0% +pointing towards putting downwards okay + + + align:start position:0% +pointing towards putting downwards okay +so we can talk about strictly convex + + align:start position:0% +so we can talk about strictly convex + + + align:start position:0% +so we can talk about strictly convex +function so convex is just happening + + align:start position:0% +function so convex is just happening + + + align:start position:0% +function so convex is just happening +when + + align:start position:0% +when + + + align:start position:0% +when +negative of the function is concave so + + align:start position:0% +negative of the function is concave so + + + align:start position:0% +negative of the function is concave so +that translate into having a secondary + + align:start position:0% +that translate into having a secondary + + + align:start position:0% +that translate into having a secondary +which is either non negative or positive + + align:start position:0% +which is either non negative or positive + + + align:start position:0% +which is either non negative or positive +depending on whether you talk about + + align:start position:0% +depending on whether you talk about + + + align:start position:0% +depending on whether you talk about +convexity or strict convexity + + align:start position:0% +convexity or strict convexity + + + align:start position:0% +convexity or strict convexity +but again we're those those convex + + align:start position:0% +but again we're those those convex + + + align:start position:0% +but again we're those those convex +functions will are convenient when + + align:start position:0% +functions will are convenient when + + + align:start position:0% +functions will are convenient when +you're trying to minimize something and + + align:start position:0% +you're trying to minimize something and + + + align:start position:0% +you're trying to minimize something and +since we're trying to maximize the + + align:start position:0% +since we're trying to maximize the + + + align:start position:0% +since we're trying to maximize the +function we're looking for concave so + + align:start position:0% +function we're looking for concave so + + + align:start position:0% +function we're looking for concave so +here are some examples let's just go + + align:start position:0% +here are some examples let's just go + + + align:start position:0% +here are some examples let's just go +through them quickly + + align:start position:0% + + + + align:start position:0% + +okay so the first one is so here I made + + align:start position:0% +okay so the first one is so here I made + + + align:start position:0% +okay so the first one is so here I made +my life a little uneasy by you know + + align:start position:0% +my life a little uneasy by you know + + + align:start position:0% +my life a little uneasy by you know +talking about functions in theta right + + align:start position:0% +talking about functions in theta right + + + align:start position:0% +talking about functions in theta right +I'm talking about likelihoods right so + + align:start position:0% +I'm talking about likelihoods right so + + + align:start position:0% +I'm talking about likelihoods right so +I'm thinking of functions where the + + align:start position:0% +I'm thinking of functions where the + + + align:start position:0% +I'm thinking of functions where the +parameter is theta so I have H of theta + + align:start position:0% +parameter is theta so I have H of theta + + + align:start position:0% +parameter is theta so I have H of theta +and so if I start with theta squared + + align:start position:0% +and so if I start with theta squared + + + align:start position:0% +and so if I start with theta squared +negative theta squared then as we said + + align:start position:0% +negative theta squared then as we said + + + align:start position:0% +negative theta squared then as we said +theta H prime prime of theta and the + + align:start position:0% +theta H prime prime of theta and the + + + align:start position:0% +theta H prime prime of theta and the +second derivative is minus 2 which + + align:start position:0% +second derivative is minus 2 which + + + align:start position:0% +second derivative is minus 2 which +implies which is strictly negative so + + align:start position:0% +implies which is strictly negative so + + + align:start position:0% +implies which is strictly negative so +this function is strictly concave okay + + align:start position:0% +this function is strictly concave okay + + + align:start position:0% +this function is strictly concave okay +another function is H of theta which is + + align:start position:0% +another function is H of theta which is + + + align:start position:0% +another function is H of theta which is +what did we pick square root of theta + + align:start position:0% +what did we pick square root of theta + + + align:start position:0% +what did we pick square root of theta +what is the first derivative 1 over 2 + + align:start position:0% +what is the first derivative 1 over 2 + + + align:start position:0% +what is the first derivative 1 over 2 +square theta what is the second + + align:start position:0% +square theta what is the second + + + align:start position:0% +square theta what is the second +derivative so that's theta to the + + align:start position:0% +derivative so that's theta to the + + + align:start position:0% +derivative so that's theta to the +negative 1/2 so I'm just picking up + + align:start position:0% +negative 1/2 so I'm just picking up + + + align:start position:0% +negative 1/2 so I'm just picking up +another negative 1/2 so I get negative + + align:start position:0% +another negative 1/2 so I get negative + + + align:start position:0% +another negative 1/2 so I get negative +1/4 and then I get theta to the 3/4 + + align:start position:0% +1/4 and then I get theta to the 3/4 + + + align:start position:0% +1/4 and then I get theta to the 3/4 +downstairs ok sorry 3 halves + + align:start position:0% + + + + align:start position:0% + +and that's strictly negative for theta + + align:start position:0% +and that's strictly negative for theta + + + align:start position:0% +and that's strictly negative for theta +say larger than zero and I really need + + align:start position:0% +say larger than zero and I really need + + + align:start position:0% +say larger than zero and I really need +to have this thing larger than zero so + + align:start position:0% +to have this thing larger than zero so + + + align:start position:0% +to have this thing larger than zero so +that it's well defined but strictly + + align:start position:0% +that it's well defined but strictly + + + align:start position:0% +that it's well defined but strictly +larger than zero is so that this thing + + align:start position:0% +larger than zero is so that this thing + + + align:start position:0% +larger than zero is so that this thing +does not blow up to infinity and it's + + align:start position:0% +does not blow up to infinity and it's + + + align:start position:0% +does not blow up to infinity and it's +true if you think about this function it + + align:start position:0% +true if you think about this function it + + + align:start position:0% +true if you think about this function it +looks like this and already the first + + align:start position:0% +looks like this and already the first + + + align:start position:0% +looks like this and already the first +derivative is going to zero to infinity + + align:start position:0% +derivative is going to zero to infinity + + + align:start position:0% +derivative is going to zero to infinity +at zero and it's a concave function okay + + align:start position:0% +at zero and it's a concave function okay + + + align:start position:0% +at zero and it's a concave function okay +another one is the log of course what is + + align:start position:0% +another one is the log of course what is + + + align:start position:0% +another one is the log of course what is +the derivative of the log that's 1 over + + align:start position:0% +the derivative of the log that's 1 over + + + align:start position:0% +the derivative of the log that's 1 over +theta sorry H prime of theta is 1 over + + align:start position:0% +theta sorry H prime of theta is 1 over + + + align:start position:0% +theta sorry H prime of theta is 1 over +theta and the second derivative + + align:start position:0% + + + + align:start position:0% + +- negative 1 over theta squared which + + align:start position:0% +- negative 1 over theta squared which + + + align:start position:0% +- negative 1 over theta squared which +again is negative if theta is strictly + + align:start position:0% +again is negative if theta is strictly + + + align:start position:0% +again is negative if theta is strictly +positive here I define it a straight I + + align:start position:0% +positive here I define it a straight I + + + align:start position:0% +positive here I define it a straight I +don't need to define it to be strictly + + align:start position:0% +don't need to define it to be strictly + + + align:start position:0% +don't need to define it to be strictly +positive here but I need it for the log + + align:start position:0% +positive here but I need it for the log + + + align:start position:0% +positive here but I need it for the log +ok and fine ok so let's just do one more + + align:start position:0% +ok and fine ok so let's just do one more + + + align:start position:0% +ok and fine ok so let's just do one more +right so H of theta is sine of theta but + + align:start position:0% +right so H of theta is sine of theta but + + + align:start position:0% +right so H of theta is sine of theta but +here I take it only on an interval + + align:start position:0% +here I take it only on an interval + + + align:start position:0% +here I take it only on an interval +because right so I said you want to + + align:start position:0% +because right so I said you want to + + + align:start position:0% +because right so I said you want to +think of this function as pointing + + align:start position:0% +think of this function as pointing + + + align:start position:0% +think of this function as pointing +always downwards and in particular you + + align:start position:0% +always downwards and in particular you + + + align:start position:0% +always downwards and in particular you +don't want this function to have an + + align:start position:0% +don't want this function to have an + + + align:start position:0% +don't want this function to have an +inflection point you don't want it to go + + align:start position:0% +inflection point you don't want it to go + + + align:start position:0% +inflection point you don't want it to go +down and then up and then down and then + + align:start position:0% +down and then up and then down and then + + + align:start position:0% +down and then up and then down and then +up because this is not concave and so + + align:start position:0% +up because this is not concave and so + + + align:start position:0% +up because this is not concave and so +sine is certainly going up and down + + align:start position:0% +sine is certainly going up and down + + + align:start position:0% +sine is certainly going up and down +right so what we do is we restrict it to + + align:start position:0% +right so what we do is we restrict it to + + + align:start position:0% +right so what we do is we restrict it to +an interval where sine is actually so + + align:start position:0% +an interval where sine is actually so + + + align:start position:0% +an interval where sine is actually so +with a site the sine function look like + + align:start position:0% +with a site the sine function look like + + + align:start position:0% +with a site the sine function look like +at 0 at 0 then it's going up where is + + align:start position:0% +at 0 at 0 then it's going up where is + + + align:start position:0% +at 0 at 0 then it's going up where is +the maximum the first maximum of the + + align:start position:0% +the maximum the first maximum of the + + + align:start position:0% +the maximum the first maximum of the +sine I'm sorry PI over 2 where it takes + + align:start position:0% +sine I'm sorry PI over 2 where it takes + + + align:start position:0% +sine I'm sorry PI over 2 where it takes +value 1 and then it goes down again and + + align:start position:0% +value 1 and then it goes down again and + + + align:start position:0% +value 1 and then it goes down again and +then that's at PI and then I go down + + align:start position:0% +then that's at PI and then I go down + + + align:start position:0% +then that's at PI and then I go down +again and here you see I actually start + + align:start position:0% +again and here you see I actually start + + + align:start position:0% +again and here you see I actually start +changing my inflection so what we do is + + align:start position:0% +changing my inflection so what we do is + + + align:start position:0% +changing my inflection so what we do is +we stop it at PI ok and look at this + + align:start position:0% +we stop it at PI ok and look at this + + + align:start position:0% +we stop it at PI ok and look at this +function it certainly looks like a + + align:start position:0% +function it certainly looks like a + + + align:start position:0% +function it certainly looks like a +parabola pointing downwards and so if + + align:start position:0% +parabola pointing downwards and so if + + + align:start position:0% +parabola pointing downwards and so if +you look at the you can check that it + + align:start position:0% +you look at the you can check that it + + + align:start position:0% +you look at the you can check that it +actually works with the derivative so + + align:start position:0% +actually works with the derivative so + + + align:start position:0% +actually works with the derivative so +the derivative of sine + + align:start position:0% +the derivative of sine + + + align:start position:0% +the derivative of sine +is cosine and the derivative of cosine + + align:start position:0% +is cosine and the derivative of cosine + + + align:start position:0% +is cosine and the derivative of cosine +is negative sine okay and this thing + + align:start position:0% +is negative sine okay and this thing + + + align:start position:0% +is negative sine okay and this thing +between zero and pi is actually positive + + align:start position:0% +between zero and pi is actually positive + + + align:start position:0% +between zero and pi is actually positive +so this entire thing is gonna be + + align:start position:0% +so this entire thing is gonna be + + + align:start position:0% +so this entire thing is gonna be +negative okay and you know I can come up + + align:start position:0% +negative okay and you know I can come up + + + align:start position:0% +negative okay and you know I can come up +with a lot of examples but let's just + + align:start position:0% +with a lot of examples but let's just + + + align:start position:0% +with a lot of examples but let's just +stick to those there's a linear function + + align:start position:0% +stick to those there's a linear function + + + align:start position:0% +stick to those there's a linear function +of course I mean it and the fine + + align:start position:0% +of course I mean it and the fine + + + align:start position:0% +of course I mean it and the fine +function is going to be concave but it's + + align:start position:0% +function is going to be concave but it's + + + align:start position:0% +function is going to be concave but it's +actually going to be convex as well + + align:start position:0% +actually going to be convex as well + + + align:start position:0% +actually going to be convex as well +which means that it's certainly not + + align:start position:0% +which means that it's certainly not + + + align:start position:0% +which means that it's certainly not +gonna be strictly concave or convex okay + + align:start position:0% +gonna be strictly concave or convex okay + + + align:start position:0% +gonna be strictly concave or convex okay +so d here's your standard picture and + + align:start position:0% +so d here's your standard picture and + + + align:start position:0% +so d here's your standard picture and +here if you look at the dotted line what + + align:start position:0% +here if you look at the dotted line what + + + align:start position:0% +here if you look at the dotted line what +it tells me is that a concave function + + align:start position:0% +it tells me is that a concave function + + + align:start position:0% +it tells me is that a concave function +and the property we're going to be using + + align:start position:0% +and the property we're going to be using + + + align:start position:0% +and the property we're going to be using +is that if a strictly concave function + + align:start position:0% +is that if a strictly concave function + + + align:start position:0% +is that if a strictly concave function +as a maximum which is not always the + + align:start position:0% +as a maximum which is not always the + + + align:start position:0% +as a maximum which is not always the +case but if it has a maximum then that's + + align:start position:0% +case but if it has a maximum then that's + + + align:start position:0% +case but if it has a maximum then that's +it's actually must be sorry local + + align:start position:0% +it's actually must be sorry local + + + align:start position:0% +it's actually must be sorry local +maximum it must be a global maximum + + align:start position:0% +maximum it must be a global maximum + + + align:start position:0% +maximum it must be a global maximum +okay so just the fact that it goes up + + align:start position:0% +okay so just the fact that it goes up + + + align:start position:0% +okay so just the fact that it goes up +and down and not again means that + + align:start position:0% +and down and not again means that + + + align:start position:0% +and down and not again means that +there's only global Maxima that can + + align:start position:0% +there's only global Maxima that can + + + align:start position:0% +there's only global Maxima that can +exist now if you look for example at the + + align:start position:0% +exist now if you look for example at the + + + align:start position:0% +exist now if you look for example at the +square root function if I look at the + + align:start position:0% +square root function if I look at the + + + align:start position:0% +square root function if I look at the +entire positive real line then this + + align:start position:0% +entire positive real line then this + + + align:start position:0% +entire positive real line then this +thing is never gonna attain a maximum + + align:start position:0% +thing is never gonna attain a maximum + + + align:start position:0% +thing is never gonna attain a maximum +it's just going to infinity as X goes to + + align:start position:0% +it's just going to infinity as X goes to + + + align:start position:0% +it's just going to infinity as X goes to +infinity so if I wanted to find a + + align:start position:0% +infinity so if I wanted to find a + + + align:start position:0% +infinity so if I wanted to find a +maximum I would have to stop somewhere + + align:start position:0% +maximum I would have to stop somewhere + + + align:start position:0% +maximum I would have to stop somewhere +and say that the maximum is attained at + + align:start position:0% +and say that the maximum is attained at + + + align:start position:0% +and say that the maximum is attained at +the right-hand side okay so that's the + + align:start position:0% +the right-hand side okay so that's the + + + align:start position:0% +the right-hand side okay so that's the +beauty about convex functions or concave + + align:start position:0% +beauty about convex functions or concave + + + align:start position:0% +beauty about convex functions or concave +functions is that essentially this + + align:start position:0% +functions is that essentially this + + + align:start position:0% +functions is that essentially this +functions are easy to maximize and if + + align:start position:0% +functions are easy to maximize and if + + + align:start position:0% +functions are easy to maximize and if +you if I tell you a function is concave + + align:start position:0% +you if I tell you a function is concave + + + align:start position:0% +you if I tell you a function is concave +you take the first derivative set it + + align:start position:0% +you take the first derivative set it + + + align:start position:0% +you take the first derivative set it +equal to zero if you find a point that + + align:start position:0% +equal to zero if you find a point that + + + align:start position:0% +equal to zero if you find a point that +satisfies this then it must be a global + + align:start position:0% +satisfies this then it must be a global + + + align:start position:0% +satisfies this then it must be a global +maximum okay yeah + + align:start position:0% + + + + align:start position:0% + +so you won't get them so you want the + + align:start position:0% +so you won't get them so you want the + + + align:start position:0% +so you won't get them so you want the +function to be concave on what on the + + align:start position:0% +function to be concave on what on the + + + align:start position:0% +function to be concave on what on the +Union of the under on the convex all of + + align:start position:0% +Union of the under on the convex all of + + + align:start position:0% +Union of the under on the convex all of +the intervals oh you want it to be okay + + align:start position:0% +the intervals oh you want it to be okay + + + align:start position:0% +the intervals oh you want it to be okay +okay okay okay you're right so maybe the + + align:start position:0% +okay okay okay you're right so maybe the + + + align:start position:0% +okay okay okay you're right so maybe the +definition so you're pointing to a + + align:start position:0% +definition so you're pointing to a + + + align:start position:0% +definition so you're pointing to a +weakness in the definition let's just + + align:start position:0% +weakness in the definition let's just + + + align:start position:0% +weakness in the definition let's just +say that theta is a convex set and then + + align:start position:0% +say that theta is a convex set and then + + + align:start position:0% +say that theta is a convex set and then +you're good okay so you're right if + + align:start position:0% +you're good okay so you're right if + + + align:start position:0% +you're good okay so you're right if +theta is not so yeah since I can + + align:start position:0% +theta is not so yeah since I can + + + align:start position:0% +theta is not so yeah since I can +actually just said that this is true + + align:start position:0% +actually just said that this is true + + + align:start position:0% +actually just said that this is true +only for theta I can just take pieces of + + align:start position:0% +only for theta I can just take pieces of + + + align:start position:0% +only for theta I can just take pieces of +concave functions right you can do this + + align:start position:0% +concave functions right you can do this + + + align:start position:0% +concave functions right you can do this +and then on the next one I can do this + + align:start position:0% +and then on the next one I can do this + + + align:start position:0% +and then on the next one I can do this +the next one I can do this and then I + + align:start position:0% +the next one I can do this and then I + + + align:start position:0% +the next one I can do this and then I +would have a bunch of them but what I + + align:start position:0% +would have a bunch of them but what I + + + align:start position:0% +would have a bunch of them but what I +want is that think of it as a global + + align:start position:0% +want is that think of it as a global + + + align:start position:0% +want is that think of it as a global +function on some convex set you're right + + align:start position:0% +function on some convex set you're right + + + align:start position:0% +function on some convex set you're right +so think of theta is being convex with + + align:start position:0% +so think of theta is being convex with + + + align:start position:0% +so think of theta is being convex with +this guy an interval if it's a real line + + align:start position:0% + + + + align:start position:0% + +okay so as I said for more generally so + + align:start position:0% +okay so as I said for more generally so + + + align:start position:0% +okay so as I said for more generally so +we can actually define concave functions + + align:start position:0% +we can actually define concave functions + + + align:start position:0% +we can actually define concave functions +more generally in higher dimensions and + + align:start position:0% +more generally in higher dimensions and + + + align:start position:0% +more generally in higher dimensions and +that will be useful if theta has more + + align:start position:0% +that will be useful if theta has more + + + align:start position:0% +that will be useful if theta has more +dimension it's not just one parameter + + align:start position:0% +dimension it's not just one parameter + + + align:start position:0% +dimension it's not just one parameter +but several parameters and for that you + + align:start position:0% +but several parameters and for that you + + + align:start position:0% +but several parameters and for that you +need to remind yourself of calculus two + + align:start position:0% +need to remind yourself of calculus two + + + align:start position:0% +need to remind yourself of calculus two +and you have a generalization of the + + align:start position:0% +and you have a generalization of the + + + align:start position:0% +and you have a generalization of the +notion of derivative which is called the + + align:start position:0% +notion of derivative which is called the + + + align:start position:0% +notion of derivative which is called the +gradient which is basically a vector + + align:start position:0% +gradient which is basically a vector + + + align:start position:0% +gradient which is basically a vector +where each coordinate is just the + + align:start position:0% +where each coordinate is just the + + + align:start position:0% +where each coordinate is just the +partial derivative with respect to each + + align:start position:0% +partial derivative with respect to each + + + align:start position:0% +partial derivative with respect to each +coordinate of theta and the Hessian is a + + align:start position:0% +coordinate of theta and the Hessian is a + + + align:start position:0% +coordinate of theta and the Hessian is a +matrix which is essentially a + + align:start position:0% +matrix which is essentially a + + + align:start position:0% +matrix which is essentially a +generalization of the second derivative + + align:start position:0% +generalization of the second derivative + + + align:start position:0% +generalization of the second derivative +I denoted by nabla squared but you can + + align:start position:0% +I denoted by nabla squared but you can + + + align:start position:0% +I denoted by nabla squared but you can +write it the way you want and so this + + align:start position:0% +write it the way you want and so this + + + align:start position:0% +write it the way you want and so this +matrix here is taking as entry the + + align:start position:0% +matrix here is taking as entry the + + + align:start position:0% +matrix here is taking as entry the +partial derivative second partial + + align:start position:0% +partial derivative second partial + + + align:start position:0% +partial derivative second partial +derivative of H with respect to theta I + + align:start position:0% +derivative of H with respect to theta I + + + align:start position:0% +derivative of H with respect to theta I +and theta J okay and so that's the IJ + + align:start position:0% +and theta J okay and so that's the IJ + + + align:start position:0% +and theta J okay and so that's the IJ +entry who has never seen that + + align:start position:0% + + + + align:start position:0% + +okay so now being concave here is + + align:start position:0% +okay so now being concave here is + + + align:start position:0% +okay so now being concave here is +essentially generalizing the saying that + + align:start position:0% +essentially generalizing the saying that + + + align:start position:0% +essentially generalizing the saying that +a vector is equal to zero well that's + + align:start position:0% +a vector is equal to zero well that's + + + align:start position:0% +a vector is equal to zero well that's +just setting the vector sorry saying + + align:start position:0% +just setting the vector sorry saying + + + align:start position:0% +just setting the vector sorry saying +that the first-order condition to say + + align:start position:0% +that the first-order condition to say + + + align:start position:0% +that the first-order condition to say +that it's a maximum is going to be the + + align:start position:0% +that it's a maximum is going to be the + + + align:start position:0% +that it's a maximum is going to be the +same saying that a function has a + + align:start position:0% +same saying that a function has a + + + align:start position:0% +same saying that a function has a +gradient equal to zero is the same as + + align:start position:0% +gradient equal to zero is the same as + + + align:start position:0% +gradient equal to zero is the same as +saying that it has that each of its + + align:start position:0% +saying that it has that each of its + + + align:start position:0% +saying that it has that each of its +coordinates are equal to zero and that's + + align:start position:0% +coordinates are equal to zero and that's + + + align:start position:0% +coordinates are equal to zero and that's +actually going to be a condition for a + + align:start position:0% +actually going to be a condition for a + + + align:start position:0% +actually going to be a condition for a +global maximum here but so to check + + align:start position:0% +global maximum here but so to check + + + align:start position:0% +global maximum here but so to check +convexity we need to see that our matrix + + align:start position:0% +convexity we need to see that our matrix + + + align:start position:0% +convexity we need to see that our matrix +itself is negative sorry to check + + align:start position:0% +itself is negative sorry to check + + + align:start position:0% +itself is negative sorry to check +concavity we need to check the remai + + align:start position:0% +concavity we need to check the remai + + + align:start position:0% +concavity we need to check the remai +tricks is negative and there is a notion + + align:start position:0% +tricks is negative and there is a notion + + + align:start position:0% +tricks is negative and there is a notion +among matrices that compare matrix to + + align:start position:0% +among matrices that compare matrix to + + + align:start position:0% +among matrices that compare matrix to +zero and that's exactly this notion you + + align:start position:0% +zero and that's exactly this notion you + + + align:start position:0% +zero and that's exactly this notion you +pre and post multiply by the same X so + + align:start position:0% +pre and post multiply by the same X so + + + align:start position:0% +pre and post multiply by the same X so +that works for symmetric matrices and + + align:start position:0% +that works for symmetric matrices and + + + align:start position:0% +that works for symmetric matrices and +which is the case here and so you pre + + align:start position:0% +which is the case here and so you pre + + + align:start position:0% +which is the case here and so you pre +multiply by X post multiply by the same + + align:start position:0% +multiply by X post multiply by the same + + + align:start position:0% +multiply by X post multiply by the same +X oh right so you have your matrix your + + align:start position:0% +X oh right so you have your matrix your + + + align:start position:0% +X oh right so you have your matrix your +hash in here + + align:start position:0% + + + + align:start position:0% + +it's a D by D matrix if you have a D + + align:start position:0% +it's a D by D matrix if you have a D + + + align:start position:0% +it's a D by D matrix if you have a D +dimensional matrix so let's call it okay + + align:start position:0% +dimensional matrix so let's call it okay + + + align:start position:0% +dimensional matrix so let's call it okay +and then here I pre multiply by X + + align:start position:0% +and then here I pre multiply by X + + + align:start position:0% +and then here I pre multiply by X +transpose I pull smalt apply by X and + + align:start position:0% +transpose I pull smalt apply by X and + + + align:start position:0% +transpose I pull smalt apply by X and +this has to be non positive if I want it + + align:start position:0% +this has to be non positive if I want it + + + align:start position:0% +this has to be non positive if I want it +to be concave and strictly negative if I + + align:start position:0% +to be concave and strictly negative if I + + + align:start position:0% +to be concave and strictly negative if I +want it to be strictly concave okay + + align:start position:0% +want it to be strictly concave okay + + + align:start position:0% +want it to be strictly concave okay +that's just a real generalization you + + align:start position:0% +that's just a real generalization you + + + align:start position:0% +that's just a real generalization you +can check for yourself that this is the + + align:start position:0% +can check for yourself that this is the + + + align:start position:0% +can check for yourself that this is the +same thing if I were in dimension 1 this + + align:start position:0% +same thing if I were in dimension 1 this + + + align:start position:0% +same thing if I were in dimension 1 this +would be the same thing why because in + + align:start position:0% +would be the same thing why because in + + + align:start position:0% +would be the same thing why because in +dimension 1 pre and post multiplying by + + align:start position:0% +dimension 1 pre and post multiplying by + + + align:start position:0% +dimension 1 pre and post multiplying by +X is the same as multiplying by x + + align:start position:0% +X is the same as multiplying by x + + + align:start position:0% +X is the same as multiplying by x +squared because in dimension 1 I can + + align:start position:0% +squared because in dimension 1 I can + + + align:start position:0% +squared because in dimension 1 I can +just move my x's around right and so + + align:start position:0% +just move my x's around right and so + + + align:start position:0% +just move my x's around right and so +that would just mean the first condition + + align:start position:0% +that would just mean the first condition + + + align:start position:0% +that would just mean the first condition +would mean in dimension 1 that the + + align:start position:0% +would mean in dimension 1 that the + + + align:start position:0% +would mean in dimension 1 that the +second derivative times X square has to + + align:start position:0% +second derivative times X square has to + + + align:start position:0% +second derivative times X square has to +be none has to be less than or equal to + + align:start position:0% +be none has to be less than or equal to + + + align:start position:0% +be none has to be less than or equal to +0 so here I need this for all X's that + + align:start position:0% +0 so here I need this for all X's that + + + align:start position:0% +0 so here I need this for all X's that +are not 0 because I can take X to be 0 + + align:start position:0% +are not 0 because I can take X to be 0 + + + align:start position:0% +are not 0 because I can take X to be 0 +and make this equal to 0 right so this + + align:start position:0% +and make this equal to 0 right so this + + + align:start position:0% +and make this equal to 0 right so this +is for X's that are not equal to 0 okay + + align:start position:0% +is for X's that are not equal to 0 okay + + + align:start position:0% +is for X's that are not equal to 0 okay +and so some examples just look at this + + align:start position:0% +and so some examples just look at this + + + align:start position:0% +and so some examples just look at this +function so now I have functions that + + align:start position:0% +function so now I have functions that + + + align:start position:0% +function so now I have functions that +depend on two parameters theta 1 and + + align:start position:0% +depend on two parameters theta 1 and + + + align:start position:0% +depend on two parameters theta 1 and +theta 2 so the first one is so if I take + + align:start position:0% +theta 2 so the first one is so if I take + + + align:start position:0% +theta 2 so the first one is so if I take +theta to be equal to now I need two + + align:start position:0% +theta to be equal to now I need two + + + align:start position:0% +theta to be equal to now I need two +parameters R squared and I look at the + + align:start position:0% +parameters R squared and I look at the + + + align:start position:0% +parameters R squared and I look at the +function which is H of theta can + + align:start position:0% +function which is H of theta can + + + align:start position:0% +function which is H of theta can +somebody tell me what H of theta is + + align:start position:0% + + + + align:start position:0% + +minus 2 theta 2 squared + + align:start position:0% +minus 2 theta 2 squared + + + align:start position:0% +minus 2 theta 2 squared +okay so let's compute the gradient of H + + align:start position:0% +okay so let's compute the gradient of H + + + align:start position:0% +okay so let's compute the gradient of H +of theta ok so it's gonna be something + + align:start position:0% +of theta ok so it's gonna be something + + + align:start position:0% +of theta ok so it's gonna be something +that has two coordinates to get the + + align:start position:0% +that has two coordinates to get the + + + align:start position:0% +that has two coordinates to get the +first coordinate what do I do well I + + align:start position:0% +first coordinate what do I do well I + + + align:start position:0% +first coordinate what do I do well I +take the derivative with respect to + + align:start position:0% +take the derivative with respect to + + + align:start position:0% +take the derivative with respect to +theta I want thinking of theta 2 as + + align:start position:0% +theta I want thinking of theta 2 as + + + align:start position:0% +theta I want thinking of theta 2 as +being a constant so this thing is going + + align:start position:0% +being a constant so this thing is going + + + align:start position:0% +being a constant so this thing is going +to go away and so I get negative 2 theta + + align:start position:0% +to go away and so I get negative 2 theta + + + align:start position:0% +to go away and so I get negative 2 theta +1 and when I take the derivative with + + align:start position:0% +1 and when I take the derivative with + + + align:start position:0% +1 and when I take the derivative with +respect to the second part thinking of + + align:start position:0% +respect to the second part thinking of + + + align:start position:0% +respect to the second part thinking of +this part is being constant I get minus + + align:start position:0% +this part is being constant I get minus + + + align:start position:0% +this part is being constant I get minus +4 theta 2 okay + + align:start position:0% +4 theta 2 okay + + + align:start position:0% +4 theta 2 okay +is that clear for everyone that's just + + align:start position:0% +is that clear for everyone that's just + + + align:start position:0% +is that clear for everyone that's just +the definition of partial derivatives + + align:start position:0% + + + + align:start position:0% + +and then if I want to do the Hessian so + + align:start position:0% +and then if I want to do the Hessian so + + + align:start position:0% +and then if I want to do the Hessian so +now I'm gonna get a two by two matrix + + align:start position:0% +now I'm gonna get a two by two matrix + + + align:start position:0% +now I'm gonna get a two by two matrix +the first guy here I take the first so + + align:start position:0% +the first guy here I take the first so + + + align:start position:0% +the first guy here I take the first so +this guy I get by taking the derivative + + align:start position:0% +this guy I get by taking the derivative + + + align:start position:0% +this guy I get by taking the derivative +of this guy respect to theta one so + + align:start position:0% +of this guy respect to theta one so + + + align:start position:0% +of this guy respect to theta one so +that's easy so that's just minus two + + align:start position:0% +that's easy so that's just minus two + + + align:start position:0% +that's easy so that's just minus two +this guy I get by taking derivative this + + align:start position:0% +this guy I get by taking derivative this + + + align:start position:0% +this guy I get by taking derivative this +guy with respect to theta two + + align:start position:0% +guy with respect to theta two + + + align:start position:0% +guy with respect to theta two +so I get what zero I treat this guy as + + align:start position:0% +so I get what zero I treat this guy as + + + align:start position:0% +so I get what zero I treat this guy as +being a constant this guy is also going + + align:start position:0% +being a constant this guy is also going + + + align:start position:0% +being a constant this guy is also going +to be zero because I take the derivative + + align:start position:0% +to be zero because I take the derivative + + + align:start position:0% +to be zero because I take the derivative +of this guy with respect to theta one + + align:start position:0% +of this guy with respect to theta one + + + align:start position:0% +of this guy with respect to theta one +and then I take the derivative of this + + align:start position:0% +and then I take the derivative of this + + + align:start position:0% +and then I take the derivative of this +guy with respect to theta 2 so I get + + align:start position:0% +guy with respect to theta 2 so I get + + + align:start position:0% +guy with respect to theta 2 so I get +minus four okay so now I want to check + + align:start position:0% +minus four okay so now I want to check + + + align:start position:0% +minus four okay so now I want to check +that this function that this matrix + + align:start position:0% +that this function that this matrix + + + align:start position:0% +that this function that this matrix +satisfies X transpose this matrix X is + + align:start position:0% +satisfies X transpose this matrix X is + + + align:start position:0% +satisfies X transpose this matrix X is +negative so what I do is so what is X + + align:start position:0% +negative so what I do is so what is X + + + align:start position:0% +negative so what I do is so what is X +transpose X so if I do X transpose Delta + + align:start position:0% +transpose X so if I do X transpose Delta + + + align:start position:0% +transpose X so if I do X transpose Delta +squared H theta for X what I get is + + align:start position:0% +squared H theta for X what I get is + + + align:start position:0% +squared H theta for X what I get is +minus two x one squared minus four X 2 + + align:start position:0% +minus two x one squared minus four X 2 + + + align:start position:0% +minus two x one squared minus four X 2 +squared okay because this matrix is + + align:start position:0% +squared okay because this matrix is + + + align:start position:0% +squared okay because this matrix is +diagonal so all it does it just waits + + align:start position:0% +diagonal so all it does it just waits + + + align:start position:0% +diagonal so all it does it just waits +the square of the X's so this guy is + + align:start position:0% +the square of the X's so this guy is + + + align:start position:0% +the square of the X's so this guy is +definitely negative this guy is negative + + align:start position:0% +definitely negative this guy is negative + + + align:start position:0% +definitely negative this guy is negative +and actually if if one of the two is + + align:start position:0% +and actually if if one of the two is + + + align:start position:0% +and actually if if one of the two is +nonzero which means that X is nonzero + + align:start position:0% +nonzero which means that X is nonzero + + + align:start position:0% +nonzero which means that X is nonzero +then this thing is actually strictly + + align:start position:0% +then this thing is actually strictly + + + align:start position:0% +then this thing is actually strictly +negative so this function is actually + + align:start position:0% +negative so this function is actually + + + align:start position:0% +negative so this function is actually +strictly concave okay and it looks like + + align:start position:0% +strictly concave okay and it looks like + + + align:start position:0% +strictly concave okay and it looks like +a parabola that's slightly distorted in + + align:start position:0% +a parabola that's slightly distorted in + + + align:start position:0% +a parabola that's slightly distorted in +one direction okay + + align:start position:0% + + + + align:start position:0% + +so well I mean I know this might have + + align:start position:0% +so well I mean I know this might have + + + align:start position:0% +so well I mean I know this might have +been some time ago maybe for some of you + + align:start position:0% +been some time ago maybe for some of you + + + align:start position:0% +been some time ago maybe for some of you +might have been since high school so + + align:start position:0% +might have been since high school so + + + align:start position:0% +might have been since high school so +just remind yourself of doing second + + align:start position:0% +just remind yourself of doing second + + + align:start position:0% +just remind yourself of doing second +derivatives and Hessians and things like + + align:start position:0% +derivatives and Hessians and things like + + + align:start position:0% +derivatives and Hessians and things like +this here's another one as an exercise H + + align:start position:0% +this here's another one as an exercise H + + + align:start position:0% +this here's another one as an exercise H +is minus theta 1 minus theta 2 squared + + align:start position:0% +is minus theta 1 minus theta 2 squared + + + align:start position:0% +is minus theta 1 minus theta 2 squared +so this one is going to actually not be + + align:start position:0% +so this one is going to actually not be + + + align:start position:0% +so this one is going to actually not be +is actually not gonna be diagonal the + + align:start position:0% +is actually not gonna be diagonal the + + + align:start position:0% +is actually not gonna be diagonal the +Hessian is not gonna be diagonal + + align:start position:0% +Hessian is not gonna be diagonal + + + align:start position:0% +Hessian is not gonna be diagonal +who would like to do this now in class + + align:start position:0% +who would like to do this now in class + + + align:start position:0% +who would like to do this now in class +ok thank you this is not a calculus + + align:start position:0% +ok thank you this is not a calculus + + + align:start position:0% +ok thank you this is not a calculus +class so you can just do it as a + + align:start position:0% +class so you can just do it as a + + + align:start position:0% +class so you can just do it as a +calculus exercise and you can do it for + + align:start position:0% +calculus exercise and you can do it for + + + align:start position:0% +calculus exercise and you can do it for +log as well now there is a nice recipe + + align:start position:0% +log as well now there is a nice recipe + + + align:start position:0% +log as well now there is a nice recipe +for concavity that works for for the + + align:start position:0% +for concavity that works for for the + + + align:start position:0% +for concavity that works for for the +second one and the third one and the + + align:start position:0% +second one and the third one and the + + + align:start position:0% +second one and the third one and the +thing is if you look at those particular + + align:start position:0% +thing is if you look at those particular + + + align:start position:0% +thing is if you look at those particular +functions what I'm doing is I'm taking + + align:start position:0% +functions what I'm doing is I'm taking + + + align:start position:0% +functions what I'm doing is I'm taking +first of all a linear combination of my + + align:start position:0% +first of all a linear combination of my + + + align:start position:0% +first of all a linear combination of my +arguments and then I take a concave + + align:start position:0% +arguments and then I take a concave + + + align:start position:0% +arguments and then I take a concave +function of this guy and this is always + + align:start position:0% +function of this guy and this is always + + + align:start position:0% +function of this guy and this is always +gonna work this is always gonna give me + + align:start position:0% +gonna work this is always gonna give me + + + align:start position:0% +gonna work this is always gonna give me +a concave function so the computations + + align:start position:0% +a concave function so the computations + + + align:start position:0% +a concave function so the computations +that just made I actually never made + + align:start position:0% +that just made I actually never made + + + align:start position:0% +that just made I actually never made +them when I prepared those slides + + align:start position:0% +them when I prepared those slides + + + align:start position:0% +them when I prepared those slides +because I don't have to I know that if I + + align:start position:0% +because I don't have to I know that if I + + + align:start position:0% +because I don't have to I know that if I +take a linear combination of those + + align:start position:0% +take a linear combination of those + + + align:start position:0% +take a linear combination of those +things and then I take a concave + + align:start position:0% +things and then I take a concave + + + align:start position:0% +things and then I take a concave +function of this guy I'm always gonna + + align:start position:0% +function of this guy I'm always gonna + + + align:start position:0% +function of this guy I'm always gonna +get a concave function okay so that's an + + align:start position:0% +get a concave function okay so that's an + + + align:start position:0% +get a concave function okay so that's an +easy way to to check this or at least + + align:start position:0% +easy way to to check this or at least + + + align:start position:0% +easy way to to check this or at least +you you know at least as a sanity check + + align:start position:0% +you you know at least as a sanity check + + + align:start position:0% +you you know at least as a sanity check +all right and so as I said finding + + align:start position:0% +all right and so as I said finding + + + align:start position:0% +all right and so as I said finding +maximizers of concave or strictly + + align:start position:0% +maximizers of concave or strictly + + + align:start position:0% +maximizers of concave or strictly +concave function is the same as it was + + align:start position:0% +concave function is the same as it was + + + align:start position:0% +concave function is the same as it was +in the one-dimensional case what I do + + align:start position:0% +in the one-dimensional case what I do + + + align:start position:0% +in the one-dimensional case what I do +sorry so in the one-dimensional case we + + align:start position:0% +sorry so in the one-dimensional case we + + + align:start position:0% +sorry so in the one-dimensional case we +just agreed that we just think they're + + align:start position:0% +just agreed that we just think they're + + + align:start position:0% +just agreed that we just think they're +better than set it to zero in the higher + + align:start position:0% +better than set it to zero in the higher + + + align:start position:0% +better than set it to zero in the higher +dimensional case we take the gradient + + align:start position:0% +dimensional case we take the gradient + + + align:start position:0% +dimensional case we take the gradient +and set it equal to zero again that's + + align:start position:0% +and set it equal to zero again that's + + + align:start position:0% +and set it equal to zero again that's +calculus all right so it turns out that + + align:start position:0% +calculus all right so it turns out that + + + align:start position:0% +calculus all right so it turns out that +so this is going to give me equations + + align:start position:0% +so this is going to give me equations + + + align:start position:0% +so this is going to give me equations +right the first one is an equation in + + align:start position:0% +right the first one is an equation in + + + align:start position:0% +right the first one is an equation in +theta the second one is an equation in + + align:start position:0% +theta the second one is an equation in + + + align:start position:0% +theta the second one is an equation in +theta 1 theta 2 theta 3 all the way to + + align:start position:0% +theta 1 theta 2 theta 3 all the way to + + + align:start position:0% +theta 1 theta 2 theta 3 all the way to +theta D and it doesn't mean that because + + align:start position:0% +theta D and it doesn't mean that because + + + align:start position:0% +theta D and it doesn't mean that because +I can write this equation that I can + + align:start position:0% +I can write this equation that I can + + + align:start position:0% +I can write this equation that I can +actually solve it by this equation might + + align:start position:0% +actually solve it by this equation might + + + align:start position:0% +actually solve it by this equation might +be super nasty might be like I don't + + align:start position:0% +be super nasty might be like I don't + + + align:start position:0% +be super nasty might be like I don't +know some polynomial in Exponential's + + align:start position:0% +know some polynomial in Exponential's + + + align:start position:0% +know some polynomial in Exponential's +and logs equals + + align:start position:0% +and logs equals + + + align:start position:0% +and logs equals +or some crazy thing and so the the + + align:start position:0% +or some crazy thing and so the the + + + align:start position:0% +or some crazy thing and so the the +there's actually four concave function + + align:start position:0% +there's actually four concave function + + + align:start position:0% +there's actually four concave function +since we know there's a unique Maximizer + + align:start position:0% +since we know there's a unique Maximizer + + + align:start position:0% +since we know there's a unique Maximizer +there's this theory of concave convex + + align:start position:0% +there's this theory of concave convex + + + align:start position:0% +there's this theory of concave convex +optimization which really since those + + align:start position:0% +optimization which really since those + + + align:start position:0% +optimization which really since those +books are talking about minimizing you + + align:start position:0% +books are talking about minimizing you + + + align:start position:0% +books are talking about minimizing you +had to find some sort of direction but + + align:start position:0% +had to find some sort of direction but + + + align:start position:0% +had to find some sort of direction but +you can think of it as the theory of + + align:start position:0% +you can think of it as the theory of + + + align:start position:0% +you can think of it as the theory of +concave maximization and they allow you + + align:start position:0% +concave maximization and they allow you + + + align:start position:0% +concave maximization and they allow you +to find algorithms to solve this + + align:start position:0% +to find algorithms to solve this + + + align:start position:0% +to find algorithms to solve this +numerically and fairly efficiently okay + + align:start position:0% +numerically and fairly efficiently okay + + + align:start position:0% +numerically and fairly efficiently okay +that means fast even if DS of size + + align:start position:0% +that means fast even if DS of size + + + align:start position:0% +that means fast even if DS of size +10,000 you're gonna wait for one second + + align:start position:0% +10,000 you're gonna wait for one second + + + align:start position:0% +10,000 you're gonna wait for one second +is gonna tell you what the maximum is + + align:start position:0% +is gonna tell you what the maximum is + + + align:start position:0% +is gonna tell you what the maximum is +okay and that's what machine learning is + + align:start position:0% +okay and that's what machine learning is + + + align:start position:0% +okay and that's what machine learning is +about if you've taken any class on + + align:start position:0% +about if you've taken any class on + + + align:start position:0% +about if you've taken any class on +machine learning there's a lot of + + align:start position:0% +machine learning there's a lot of + + + align:start position:0% +machine learning there's a lot of +optimization because they have really + + align:start position:0% +optimization because they have really + + + align:start position:0% +optimization because they have really +really big problems to solve often in + + align:start position:0% +really big problems to solve often in + + + align:start position:0% +really big problems to solve often in +this class since this is more + + align:start position:0% +this class since this is more + + + align:start position:0% +this class since this is more +introductory statistics we will have a + + align:start position:0% +introductory statistics we will have a + + + align:start position:0% +introductory statistics we will have a +closed form for the maximum likelihood + + align:start position:0% +closed form for the maximum likelihood + + + align:start position:0% +closed form for the maximum likelihood +estimator will be saying theta hat + + align:start position:0% +estimator will be saying theta hat + + + align:start position:0% +estimator will be saying theta hat +equals and say X bar and that will be a + + align:start position:0% +equals and say X bar and that will be a + + + align:start position:0% +equals and say X bar and that will be a +maximum likelihood estimator + + align:start position:0% +maximum likelihood estimator + + + align:start position:0% +maximum likelihood estimator +okay so just why I just so has anybody + + align:start position:0% +okay so just why I just so has anybody + + + align:start position:0% +okay so just why I just so has anybody +seen convex optimization before so let + + align:start position:0% +seen convex optimization before so let + + + align:start position:0% +seen convex optimization before so let +me just give you an intuition why those + + align:start position:0% +me just give you an intuition why those + + + align:start position:0% +me just give you an intuition why those +functions are easy to maximize or to + + align:start position:0% +functions are easy to maximize or to + + + align:start position:0% +functions are easy to maximize or to +minimize in one dimension it's actually + + align:start position:0% +minimize in one dimension it's actually + + + align:start position:0% +minimize in one dimension it's actually +very easy for you two to see that and + + align:start position:0% +very easy for you two to see that and + + + align:start position:0% +very easy for you two to see that and +the reason is this if I want to maximize + + align:start position:0% +the reason is this if I want to maximize + + + align:start position:0% +the reason is this if I want to maximize +the concave function what I need to do + + align:start position:0% +the concave function what I need to do + + + align:start position:0% +the concave function what I need to do +is to be able to query a point and get + + align:start position:0% +is to be able to query a point and get + + + align:start position:0% +is to be able to query a point and get +as an answer the derivative of this + + align:start position:0% +as an answer the derivative of this + + + align:start position:0% +as an answer the derivative of this +function okay so now let's say this is + + align:start position:0% +function okay so now let's say this is + + + align:start position:0% +function okay so now let's say this is +the function I want to optimize and I've + + align:start position:0% +the function I want to optimize and I've + + + align:start position:0% +the function I want to optimize and I've +been running my algorithm for you know + + align:start position:0% +been running my algorithm for you know + + + align:start position:0% +been running my algorithm for you know +10 5/10 of a second and it's at this + + align:start position:0% +10 5/10 of a second and it's at this + + + align:start position:0% +10 5/10 of a second and it's at this +point here okay that's the candidate now + + align:start position:0% +point here okay that's the candidate now + + + align:start position:0% +point here okay that's the candidate now +what I can ask is what is the derivative + + align:start position:0% +what I can ask is what is the derivative + + + align:start position:0% +what I can ask is what is the derivative +of my function here well it's gonna give + + align:start position:0% +of my function here well it's gonna give + + + align:start position:0% +of my function here well it's gonna give +me a value and this value is going to be + + align:start position:0% +me a value and this value is going to be + + + align:start position:0% +me a value and this value is going to be +either negative positive or zero well if + + align:start position:0% +either negative positive or zero well if + + + align:start position:0% +either negative positive or zero well if +it's zero that's great that means I'm + + align:start position:0% +it's zero that's great that means I'm + + + align:start position:0% +it's zero that's great that means I'm +here and I can just go home I've solved + + align:start position:0% +here and I can just go home I've solved + + + align:start position:0% +here and I can just go home I've solved +my problem okay I know there's a unique + + align:start position:0% +my problem okay I know there's a unique + + + align:start position:0% +my problem okay I know there's a unique +maximum and that's what I want to find + + align:start position:0% +maximum and that's what I want to find + + + align:start position:0% +maximum and that's what I want to find +if it's positive it actually tells me + + align:start position:0% +if it's positive it actually tells me + + + align:start position:0% +if it's positive it actually tells me +that I'm on the left of the optimizer + + align:start position:0% +that I'm on the left of the optimizer + + + align:start position:0% +that I'm on the left of the optimizer +right then I'm not the left of the + + align:start position:0% +right then I'm not the left of the + + + align:start position:0% +right then I'm not the left of the +optimum + + align:start position:0% +optimum + + + align:start position:0% +optimum +value and if it's negative it means that + + align:start position:0% +value and if it's negative it means that + + + align:start position:0% +value and if it's negative it means that +I'm at the right of the value I'm + + align:start position:0% +I'm at the right of the value I'm + + + align:start position:0% +I'm at the right of the value I'm +looking for and so most of the convex + + align:start position:0% +looking for and so most of the convex + + + align:start position:0% +looking for and so most of the convex +optimization methods basically tell you + + align:start position:0% +optimization methods basically tell you + + + align:start position:0% +optimization methods basically tell you +well if you queried the derivative and + + align:start position:0% +well if you queried the derivative and + + + align:start position:0% +well if you queried the derivative and +it's actually positive move to the right + + align:start position:0% +it's actually positive move to the right + + + align:start position:0% +it's actually positive move to the right +and if it's negative move to the left + + align:start position:0% +and if it's negative move to the left + + + align:start position:0% +and if it's negative move to the left +now by how much you move is basically + + align:start position:0% +now by how much you move is basically + + + align:start position:0% +now by how much you move is basically +well why people write books and in + + align:start position:0% +well why people write books and in + + + align:start position:0% +well why people write books and in +higher dimension it's a little more + + align:start position:0% +higher dimension it's a little more + + + align:start position:0% +higher dimension it's a little more +complicated all right because in higher + + align:start position:0% +complicated all right because in higher + + + align:start position:0% +complicated all right because in higher +dimension thinks about two dimensions + + align:start position:0% +dimension thinks about two dimensions + + + align:start position:0% +dimension thinks about two dimensions +then I'm actually the I'm only being + + align:start position:0% +then I'm actually the I'm only being + + + align:start position:0% +then I'm actually the I'm only being +able to again to get a vector and the + + align:start position:0% +able to again to get a vector and the + + + align:start position:0% +able to again to get a vector and the +vector is only telling me well here is + + align:start position:0% +vector is only telling me well here is + + + align:start position:0% +vector is only telling me well here is +half of the space in which you can move + + align:start position:0% +half of the space in which you can move + + + align:start position:0% +half of the space in which you can move +now here if you tell me move to the + + align:start position:0% +now here if you tell me move to the + + + align:start position:0% +now here if you tell me move to the +right I know exactly which direction I'm + + align:start position:0% +right I know exactly which direction I'm + + + align:start position:0% +right I know exactly which direction I'm +gonna have to move but in two dimension + + align:start position:0% +gonna have to move but in two dimension + + + align:start position:0% +gonna have to move but in two dimension +you're gonna basically tell me well move + + align:start position:0% +you're gonna basically tell me well move + + + align:start position:0% +you're gonna basically tell me well move +in this global direction and so of + + align:start position:0% +in this global direction and so of + + + align:start position:0% +in this global direction and so of +course I know there's a line on the + + align:start position:0% +course I know there's a line on the + + + align:start position:0% +course I know there's a line on the +floor I cannot move behind but even if + + align:start position:0% +floor I cannot move behind but even if + + + align:start position:0% +floor I cannot move behind but even if +you tell me draw a line on the floor and + + align:start position:0% +you tell me draw a line on the floor and + + + align:start position:0% +you tell me draw a line on the floor and +move only to that side of the line then + + align:start position:0% +move only to that side of the line then + + + align:start position:0% +move only to that side of the line then +there's many direction in that line that + + align:start position:0% +there's many direction in that line that + + + align:start position:0% +there's many direction in that line that +I can go to and that's also why there's + + align:start position:0% +I can go to and that's also why there's + + + align:start position:0% +I can go to and that's also why there's +lots of things you can do in + + align:start position:0% +lots of things you can do in + + + align:start position:0% +lots of things you can do in +optimization okay but still this putting + + align:start position:0% +optimization okay but still this putting + + + align:start position:0% +optimization okay but still this putting +this line on the floor is telling me do + + align:start position:0% +this line on the floor is telling me do + + + align:start position:0% +this line on the floor is telling me do +not go backwards and that's very + + align:start position:0% +not go backwards and that's very + + + align:start position:0% +not go backwards and that's very +important it's just telling you which + + align:start position:0% +important it's just telling you which + + + align:start position:0% +important it's just telling you which +direction I should be going + + align:start position:0% +direction I should be going + + + align:start position:0% +direction I should be going +always okay all right so and that's + + align:start position:0% +always okay all right so and that's + + + align:start position:0% +always okay all right so and that's +what's behind this notion of gradient + + align:start position:0% +what's behind this notion of gradient + + + align:start position:0% +what's behind this notion of gradient +descent algorithm a steepest descent or + + align:start position:0% +descent algorithm a steepest descent or + + + align:start position:0% +descent algorithm a steepest descent or +steepest descent actually for trying to + + align:start position:0% +steepest descent actually for trying to + + + align:start position:0% +steepest descent actually for trying to +maximize okay so let's move on so this + + align:start position:0% +maximize okay so let's move on so this + + + align:start position:0% +maximize okay so let's move on so this +course is not about optimization all + + align:start position:0% +course is not about optimization all + + + align:start position:0% +course is not about optimization all +right so as I said the likelihood was + + align:start position:0% +right so as I said the likelihood was + + + align:start position:0% +right so as I said the likelihood was +this guy the product of F of the Excise + + align:start position:0% +this guy the product of F of the Excise + + + align:start position:0% +this guy the product of F of the Excise +and one way you can do this is just + + align:start position:0% +and one way you can do this is just + + + align:start position:0% +and one way you can do this is just +basically the Joint Distribution of my + + align:start position:0% +basically the Joint Distribution of my + + + align:start position:0% +basically the Joint Distribution of my +data at the point data so now the + + align:start position:0% +data at the point data so now the + + + align:start position:0% +data at the point data so now the +likelihood formally so here I'm giving + + align:start position:0% +likelihood formally so here I'm giving + + + align:start position:0% +likelihood formally so here I'm giving +myself a model II P theta and here I'm + + align:start position:0% +myself a model II P theta and here I'm + + + align:start position:0% +myself a model II P theta and here I'm +going to assume that E is discrete so + + align:start position:0% +going to assume that E is discrete so + + + align:start position:0% +going to assume that E is discrete so +that I can talk about pmf's but + + align:start position:0% +that I can talk about pmf's but + + + align:start position:0% +that I can talk about pmf's but +everything you're doing just redo it for + + align:start position:0% +everything you're doing just redo it for + + + align:start position:0% +everything you're doing just redo it for +the sake of yourself by replacing pmf's + + align:start position:0% +the sake of yourself by replacing pmf's + + + align:start position:0% +the sake of yourself by replacing pmf's +by PDF so never + + align:start position:0% +by PDF so never + + + align:start position:0% +by PDF so never +it's gonna be fine we'll do it in a + + align:start position:0% +it's gonna be fine we'll do it in a + + + align:start position:0% +it's gonna be fine we'll do it in a +second all right so the likelihood of + + align:start position:0% +second all right so the likelihood of + + + align:start position:0% +second all right so the likelihood of +the model so here I'm not looking at the + + align:start position:0% +the model so here I'm not looking at the + + + align:start position:0% +the model so here I'm not looking at the +likelihood of a parameter I'm looking at + + align:start position:0% +likelihood of a parameter I'm looking at + + + align:start position:0% +likelihood of a parameter I'm looking at +the likelihood of a model so it's + + align:start position:0% +the likelihood of a model so it's + + + align:start position:0% +the likelihood of a model so it's +actually a function of the parameter and + + align:start position:0% +actually a function of the parameter and + + + align:start position:0% +actually a function of the parameter and +actually I'm gonna make it even a + + align:start position:0% +actually I'm gonna make it even a + + + align:start position:0% +actually I'm gonna make it even a +function of the points x1 to xn all + + align:start position:0% +function of the points x1 to xn all + + + align:start position:0% +function of the points x1 to xn all +right so I have a function and what it + + align:start position:0% +right so I have a function and what it + + + align:start position:0% +right so I have a function and what it +takes as input is all the points x1 to + + align:start position:0% +takes as input is all the points x1 to + + + align:start position:0% +takes as input is all the points x1 to +xn and a parameter a candidate parameter + + align:start position:0% +xn and a parameter a candidate parameter + + + align:start position:0% +xn and a parameter a candidate parameter +theta not the true one a candidate okay + + align:start position:0% +theta not the true one a candidate okay + + + align:start position:0% +theta not the true one a candidate okay +and what I'm going to do is I'm going to + + align:start position:0% +and what I'm going to do is I'm going to + + + align:start position:0% +and what I'm going to do is I'm going to +look at the probability that my random + + align:start position:0% +look at the probability that my random + + + align:start position:0% +look at the probability that my random +variables under this distribution p + + align:start position:0% +variables under this distribution p + + + align:start position:0% +variables under this distribution p +theta take this exact values px 1 PX 2px + + align:start position:0% +theta take this exact values px 1 PX 2px + + + align:start position:0% +theta take this exact values px 1 PX 2px +now remember if my data was independent + + align:start position:0% +now remember if my data was independent + + + align:start position:0% +now remember if my data was independent +then I could actually just say that the + + align:start position:0% +then I could actually just say that the + + + align:start position:0% +then I could actually just say that the +probability of this intersection is just + + align:start position:0% +probability of this intersection is just + + + align:start position:0% +probability of this intersection is just +a product of the probabilities and it + + align:start position:0% +a product of the probabilities and it + + + align:start position:0% +a product of the probabilities and it +would look like something like this but + + align:start position:0% +would look like something like this but + + + align:start position:0% +would look like something like this but +I can define likelihood even if I don't + + align:start position:0% +I can define likelihood even if I don't + + + align:start position:0% +I can define likelihood even if I don't +have independent random variables but + + align:start position:0% +have independent random variables but + + + align:start position:0% +have independent random variables but +think of them as being independent + + align:start position:0% +think of them as being independent + + + align:start position:0% +think of them as being independent +because that's what we're gonna + + align:start position:0% +because that's what we're gonna + + + align:start position:0% +because that's what we're gonna +encounter in this class okay I just want + + align:start position:0% +encounter in this class okay I just want + + + align:start position:0% +encounter in this class okay I just want +you to be aware that if I had dependent + + align:start position:0% +you to be aware that if I had dependent + + + align:start position:0% +you to be aware that if I had dependent +variables I could still define the + + align:start position:0% +variables I could still define the + + + align:start position:0% +variables I could still define the +likelihood I would have to understand + + align:start position:0% +likelihood I would have to understand + + + align:start position:0% +likelihood I would have to understand +how to compute this probabilities though + + align:start position:0% +how to compute this probabilities though + + + align:start position:0% +how to compute this probabilities though +to be able to compute it okay so think + + align:start position:0% +to be able to compute it okay so think + + + align:start position:0% +to be able to compute it okay so think +of Bernoulli's for example okay so + + align:start position:0% +of Bernoulli's for example okay so + + + align:start position:0% +of Bernoulli's for example okay so +here's my example of a bernly I have so + + align:start position:0% +here's my example of a bernly I have so + + + align:start position:0% +here's my example of a bernly I have so +my parameter is so my model is 0-1 + + align:start position:0% +my parameter is so my model is 0-1 + + + align:start position:0% +my parameter is so my model is 0-1 +Bernal a P P is in the interval 0 1 ok + + align:start position:0% + + + + align:start position:0% + +the probability just as a side remark + + align:start position:0% +the probability just as a side remark + + + align:start position:0% +the probability just as a side remark +I'm just gonna use the fact that I can + + align:start position:0% +I'm just gonna use the fact that I can + + + align:start position:0% +I'm just gonna use the fact that I can +actually write the PMF of a bernal in a + + align:start position:0% +actually write the PMF of a bernal in a + + + align:start position:0% +actually write the PMF of a bernal in a +very concise form right if I ask you + + align:start position:0% +very concise form right if I ask you + + + align:start position:0% +very concise form right if I ask you +what the PMF of a Bernoulli is you could + + align:start position:0% +what the PMF of a Bernoulli is you could + + + align:start position:0% +what the PMF of a Bernoulli is you could +tell me well the probability that X so + + align:start position:0% +tell me well the probability that X so + + + align:start position:0% +tell me well the probability that X so +under P the probably that X is equal to + + align:start position:0% +under P the probably that X is equal to + + + align:start position:0% +under P the probably that X is equal to +0 is 1 minus P the probability under P + + align:start position:0% +0 is 1 minus P the probability under P + + + align:start position:0% +0 is 1 minus P the probability under P +that X is equal to 1 is equal to P but I + + align:start position:0% +that X is equal to 1 is equal to P but I + + + align:start position:0% +that X is equal to 1 is equal to P but I +can be a bit smart and say that for any + + align:start position:0% +can be a bit smart and say that for any + + + align:start position:0% +can be a bit smart and say that for any +X that's either 0 or 1 the probability + + align:start position:0% +X that's either 0 or 1 the probability + + + align:start position:0% +X that's either 0 or 1 the probability +under P that X is equal to little X I + + align:start position:0% +under P that X is equal to little X I + + + align:start position:0% +under P that X is equal to little X I +can write it in a compact form + + align:start position:0% +can write it in a compact form + + + align:start position:0% +can write it in a compact form +as P to the X 1 minus P to the 1 minus X + + align:start position:0% +as P to the X 1 minus P to the 1 minus X + + + align:start position:0% +as P to the X 1 minus P to the 1 minus X +and you can check that this is the right + + align:start position:0% +and you can check that this is the right + + + align:start position:0% +and you can check that this is the right +form because well you have to check it + + align:start position:0% +form because well you have to check it + + + align:start position:0% +form because well you have to check it +only for two values of X 0 and 1 and if + + align:start position:0% +only for two values of X 0 and 1 and if + + + align:start position:0% +only for two values of X 0 and 1 and if +you plug in 1 you only keep the P if you + + align:start position:0% +you plug in 1 you only keep the P if you + + + align:start position:0% +you plug in 1 you only keep the P if you +plug in 0 you only keep the 1 minus P + + align:start position:0% +plug in 0 you only keep the 1 minus P + + + align:start position:0% +plug in 0 you only keep the 1 minus P +and that's just a trick okay I could + + align:start position:0% +and that's just a trick okay I could + + + align:start position:0% +and that's just a trick okay I could +have gone with many other ways agreed I + + align:start position:0% +have gone with many other ways agreed I + + + align:start position:0% +have gone with many other ways agreed I +could have said actually something like + + align:start position:0% +could have said actually something like + + + align:start position:0% +could have said actually something like +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +another one would be which we're not + + align:start position:0% +another one would be which we're not + + + align:start position:0% +another one would be which we're not +going to use but we could say well it's + + align:start position:0% +going to use but we could say well it's + + + align:start position:0% +going to use but we could say well it's +X P plus 1 minus X 1 minus P right + + align:start position:0% + + + + align:start position:0% + +that's another one but this one is going + + align:start position:0% +that's another one but this one is going + + + align:start position:0% +that's another one but this one is going +to be convenient okay so forget about + + align:start position:0% +to be convenient okay so forget about + + + align:start position:0% +to be convenient okay so forget about +this guy for a second alright so now I + + align:start position:0% +this guy for a second alright so now I + + + align:start position:0% +this guy for a second alright so now I +said that the likelihood is just this + + align:start position:0% +said that the likelihood is just this + + + align:start position:0% +said that the likelihood is just this +function that's computing the + + align:start position:0% +function that's computing the + + + align:start position:0% +function that's computing the +probability that X 1 is equal to little + + align:start position:0% +probability that X 1 is equal to little + + + align:start position:0% +probability that X 1 is equal to little +X 1 so likelihood is L of X 1 X and so + + align:start position:0% +X 1 so likelihood is L of X 1 X and so + + + align:start position:0% +X 1 so likelihood is L of X 1 X and so +let me try to make those calligraphic so + + align:start position:0% +let me try to make those calligraphic so + + + align:start position:0% +let me try to make those calligraphic so +you know that I'm talking about smaller + + align:start position:0% +you know that I'm talking about smaller + + + align:start position:0% +you know that I'm talking about smaller +values right + + align:start position:0% +values right + + + align:start position:0% +values right +a small X's X 1 xn and then of course P + + align:start position:0% +a small X's X 1 xn and then of course P + + + align:start position:0% +a small X's X 1 xn and then of course P +sometimes we even put I didn't do it but + + align:start position:0% +sometimes we even put I didn't do it but + + + align:start position:0% +sometimes we even put I didn't do it but +sometimes you can actually put a semi + + align:start position:0% +sometimes you can actually put a semi + + + align:start position:0% +sometimes you can actually put a semi +column here same icon so you know that + + align:start position:0% +column here same icon so you know that + + + align:start position:0% +column here same icon so you know that +those two things are treated differently + + align:start position:0% +those two things are treated differently + + + align:start position:0% +those two things are treated differently +and so now you have this thing is equal + + align:start position:0% +and so now you have this thing is equal + + + align:start position:0% +and so now you have this thing is equal +to what well is just the probability + + align:start position:0% +to what well is just the probability + + + align:start position:0% +to what well is just the probability +under P that X 1 is little X 1 all the + + align:start position:0% +under P that X 1 is little X 1 all the + + + align:start position:0% +under P that X 1 is little X 1 all the +way to X n is little like sin + + align:start position:0% +way to X n is little like sin + + + align:start position:0% +way to X n is little like sin +okay that's just the definition + + align:start position:0% + + + + align:start position:0% + +all right so now let's start working so + + align:start position:0% +all right so now let's start working so + + + align:start position:0% +all right so now let's start working so +we write the definition and then we want + + align:start position:0% +we write the definition and then we want + + + align:start position:0% +we write the definition and then we want +to make it look like something we would + + align:start position:0% +to make it look like something we would + + + align:start position:0% +to make it look like something we would +potentially be able to maximize if I + + align:start position:0% +potentially be able to maximize if I + + + align:start position:0% +potentially be able to maximize if I +were like if I take the derivative of + + align:start position:0% +were like if I take the derivative of + + + align:start position:0% +were like if I take the derivative of +this with respect to peace that very + + align:start position:0% +this with respect to peace that very + + + align:start position:0% +this with respect to peace that very +helpful because I just don't know okay + + align:start position:0% +helpful because I just don't know okay + + + align:start position:0% +helpful because I just don't know okay +just one day algebraic function of P + + align:start position:0% +just one day algebraic function of P + + + align:start position:0% +just one day algebraic function of P +okay so this thing is going to be equal + + align:start position:0% +okay so this thing is going to be equal + + + align:start position:0% +okay so this thing is going to be equal +to what well what is the first thing I + + align:start position:0% +to what well what is the first thing I + + + align:start position:0% +to what well what is the first thing I +want to use I have a probability of an + + align:start position:0% +want to use I have a probability of an + + + align:start position:0% +want to use I have a probability of an +intersection of events so it's just the + + align:start position:0% +intersection of events so it's just the + + + align:start position:0% +intersection of events so it's just the +product of the probabilities so this is + + align:start position:0% +product of the probabilities so this is + + + align:start position:0% +product of the probabilities so this is +the product from one I equal one to n of + + align:start position:0% +the product from one I equal one to n of + + + align:start position:0% +the product from one I equal one to n of +P small p X I is equal to little X I all + + align:start position:0% +P small p X I is equal to little X I all + + + align:start position:0% +P small p X I is equal to little X I all +right that's independence okay now I'm + + align:start position:0% +right that's independence okay now I'm + + + align:start position:0% +right that's independence okay now I'm +starting to be in business because for + + align:start position:0% +starting to be in business because for + + + align:start position:0% +starting to be in business because for +each P we have a closed form right I + + align:start position:0% +each P we have a closed form right I + + + align:start position:0% +each P we have a closed form right I +wrote this as this supposedly convenient + + align:start position:0% +wrote this as this supposedly convenient + + + align:start position:0% +wrote this as this supposedly convenient +form I still have to reveal to you why + + align:start position:0% +form I still have to reveal to you why + + + align:start position:0% +form I still have to reveal to you why +it's convenient so this thing is equal + + align:start position:0% +it's convenient so this thing is equal + + + align:start position:0% +it's convenient so this thing is equal +to well we said that that was p x i + + align:start position:0% +to well we said that that was p x i + + + align:start position:0% +to well we said that that was p x i +sorry little like sy 1 minus p to the 1 + + align:start position:0% +sorry little like sy 1 minus p to the 1 + + + align:start position:0% +sorry little like sy 1 minus p to the 1 +minus x i okay so that was just what i + + align:start position:0% +minus x i okay so that was just what i + + + align:start position:0% +minus x i okay so that was just what i +wrote over there that's the probability + + align:start position:0% +wrote over there that's the probability + + + align:start position:0% +wrote over there that's the probability +that X I is equal to little X I and + + align:start position:0% +that X I is equal to little X I and + + + align:start position:0% +that X I is equal to little X I and +since they all have the same parameter P + + align:start position:0% +since they all have the same parameter P + + + align:start position:0% +since they all have the same parameter P +I just have this P that shows up here + + align:start position:0% +I just have this P that shows up here + + + align:start position:0% +I just have this P that shows up here +okay and so now I'm just taking the + + align:start position:0% +okay and so now I'm just taking the + + + align:start position:0% +okay and so now I'm just taking the +products of something to the X I so it's + + align:start position:0% +products of something to the X I so it's + + + align:start position:0% +products of something to the X I so it's +this thing to the sum of the x i's + + align:start position:0% +this thing to the sum of the x i's + + + align:start position:0% +this thing to the sum of the x i's +everybody agrees with this so this is + + align:start position:0% +everybody agrees with this so this is + + + align:start position:0% +everybody agrees with this so this is +equal to P sum of the X I 1 minus P to + + align:start position:0% +equal to P sum of the X I 1 minus P to + + + align:start position:0% +equal to P sum of the X I 1 minus P to +the N minus sum of the X I + + align:start position:0% + + + + align:start position:0% + +okay if you don't feel comfortable with + + align:start position:0% +okay if you don't feel comfortable with + + + align:start position:0% +okay if you don't feel comfortable with +writing it directly you can observe that + + align:start position:0% +writing it directly you can observe that + + + align:start position:0% +writing it directly you can observe that +this thing here is actually equal to P + + align:start position:0% +this thing here is actually equal to P + + + align:start position:0% +this thing here is actually equal to P +over 1 minus P to the X I times 1 minus + + align:start position:0% +over 1 minus P to the X I times 1 minus + + + align:start position:0% +over 1 minus P to the X I times 1 minus +P okay so now when I take the product + + align:start position:0% +P okay so now when I take the product + + + align:start position:0% +P okay so now when I take the product +I'm getting the products of those + + align:start position:0% +I'm getting the products of those + + + align:start position:0% +I'm getting the products of those +geysers just to the this guy to the + + align:start position:0% +geysers just to the this guy to the + + + align:start position:0% +geysers just to the this guy to the +power some and this guy to the power N + + align:start position:0% +power some and this guy to the power N + + + align:start position:0% +power some and this guy to the power N +and then I can rewrite it like this if I + + align:start position:0% +and then I can rewrite it like this if I + + + align:start position:0% +and then I can rewrite it like this if I +want okay and so now well that's what we + + align:start position:0% +want okay and so now well that's what we + + + align:start position:0% +want okay and so now well that's what we +have here and now I'm in business + + align:start position:0% +have here and now I'm in business + + + align:start position:0% +have here and now I'm in business +because I can still hope to maximize + + align:start position:0% +because I can still hope to maximize + + + align:start position:0% +because I can still hope to maximize +this function alright and how do I + + align:start position:0% +this function alright and how do I + + + align:start position:0% +this function alright and how do I +maximize this function well I have to do + + align:start position:0% +maximize this function well I have to do + + + align:start position:0% +maximize this function well I have to do +is to take the derivative do you want to + + align:start position:0% +is to take the derivative do you want to + + + align:start position:0% +is to take the derivative do you want to +do it let's just take the derivative + + align:start position:0% +do it let's just take the derivative + + + align:start position:0% +do it let's just take the derivative +okay oh sorry I didn't tell you that the + + align:start position:0% +okay oh sorry I didn't tell you that the + + + align:start position:0% +okay oh sorry I didn't tell you that the +well the maximum like to the principle + + align:start position:0% +well the maximum like to the principle + + + align:start position:0% +well the maximum like to the principle +is to just maximum with the idea is to + + align:start position:0% +is to just maximum with the idea is to + + + align:start position:0% +is to just maximum with the idea is to +maximize this thing okay but I'm not + + align:start position:0% +maximize this thing okay but I'm not + + + align:start position:0% +maximize this thing okay but I'm not +gonna get there right now okay so let's + + align:start position:0% +gonna get there right now okay so let's + + + align:start position:0% +gonna get there right now okay so let's +do it maybe for the Poisson model for a + + align:start position:0% +do it maybe for the Poisson model for a + + + align:start position:0% +do it maybe for the Poisson model for a +second so if you want to do it for the + + align:start position:0% +second so if you want to do it for the + + + align:start position:0% +second so if you want to do it for the +Poisson model + + align:start position:0% +Poisson model + + + align:start position:0% +Poisson model +[Applause] + + align:start position:0% + + + + align:start position:0% + +so let's write the likelihood right so + + align:start position:0% +so let's write the likelihood right so + + + align:start position:0% +so let's write the likelihood right so +right now I'm not doing anything I'm not + + align:start position:0% +right now I'm not doing anything I'm not + + + align:start position:0% +right now I'm not doing anything I'm not +maximizing I'm just computing it the + + align:start position:0% +maximizing I'm just computing it the + + + align:start position:0% +maximizing I'm just computing it the +likelihood function okay so the + + align:start position:0% +likelihood function okay so the + + + align:start position:0% +likelihood function okay so the +likelihood function for quest on so now + + align:start position:0% +likelihood function for quest on so now + + + align:start position:0% +likelihood function for quest on so now +I know what is my sample space for + + align:start position:0% +I know what is my sample space for + + + align:start position:0% +I know what is my sample space for +personal part of it positive integers + + align:start position:0% +personal part of it positive integers + + + align:start position:0% +personal part of it positive integers +and well lets me write it like this + + align:start position:0% +and well lets me write it like this + + + align:start position:0% +and well lets me write it like this +twice so lambda and I'm gonna take + + align:start position:0% +twice so lambda and I'm gonna take + + + align:start position:0% +twice so lambda and I'm gonna take +lambda to be positive and so that means + + align:start position:0% +lambda to be positive and so that means + + + align:start position:0% +lambda to be positive and so that means +that the probability that under lambda + + align:start position:0% +that the probability that under lambda + + + align:start position:0% +that the probability that under lambda +that X is equal to little X in the + + align:start position:0% +that X is equal to little X in the + + + align:start position:0% +that X is equal to little X in the +sample space is lambda to the x over + + align:start position:0% +sample space is lambda to the x over + + + align:start position:0% +sample space is lambda to the x over +factorial X e to the minus lambda so + + align:start position:0% +factorial X e to the minus lambda so + + + align:start position:0% +factorial X e to the minus lambda so +that's basically the same as the compact + + align:start position:0% +that's basically the same as the compact + + + align:start position:0% +that's basically the same as the compact +form that I wrote over there + + align:start position:0% +form that I wrote over there + + + align:start position:0% +form that I wrote over there +it's just now different one and so what + + align:start position:0% +it's just now different one and so what + + + align:start position:0% +it's just now different one and so what +I want to write my likelihood again we + + align:start position:0% +I want to write my likelihood again we + + + align:start position:0% +I want to write my likelihood again we +said little X's this is equal to what + + align:start position:0% +said little X's this is equal to what + + + align:start position:0% +said little X's this is equal to what +well it's equal to the probability under + + align:start position:0% +well it's equal to the probability under + + + align:start position:0% +well it's equal to the probability under +lambda that x1 is little X 1 X n is + + align:start position:0% +lambda that x1 is little X 1 X n is + + + align:start position:0% +lambda that x1 is little X 1 X n is +little X n which is equal to the product + + align:start position:0% + + + + align:start position:0% + +okay just by independence and now I can + + align:start position:0% +okay just by independence and now I can + + + align:start position:0% +okay just by independence and now I can +write those guys as being each of them + + align:start position:0% +write those guys as being each of them + + + align:start position:0% +write those guys as being each of them +being equal 1 to N so this guy is just + + align:start position:0% +being equal 1 to N so this guy is just + + + align:start position:0% +being equal 1 to N so this guy is just +this thing where I plug in X I so I get + + align:start position:0% +this thing where I plug in X I so I get + + + align:start position:0% +this thing where I plug in X I so I get +lambda to the X I divided by factorial X + + align:start position:0% +lambda to the X I divided by factorial X + + + align:start position:0% +lambda to the X I divided by factorial X +I times e to the minus lambda ok and now + + align:start position:0% +I times e to the minus lambda ok and now + + + align:start position:0% +I times e to the minus lambda ok and now +I mean this guy is gonna be nice this + + align:start position:0% +I mean this guy is gonna be nice this + + + align:start position:0% +I mean this guy is gonna be nice this +guy it's not gonna be too nice let's + + align:start position:0% +guy it's not gonna be too nice let's + + + align:start position:0% +guy it's not gonna be too nice let's +write it what I'm gonna take the product + + align:start position:0% +write it what I'm gonna take the product + + + align:start position:0% +write it what I'm gonna take the product +of those guys here I'm gonna pick a plum + + align:start position:0% +of those guys here I'm gonna pick a plum + + + align:start position:0% +of those guys here I'm gonna pick a plum +de to the sum of the x i's here I'm + + align:start position:0% +de to the sum of the x i's here I'm + + + align:start position:0% +de to the sum of the x i's here I'm +gonna pick up exponential minus n times + + align:start position:0% +gonna pick up exponential minus n times + + + align:start position:0% +gonna pick up exponential minus n times +lambda and here I'm going to pick up + + align:start position:0% +lambda and here I'm going to pick up + + + align:start position:0% +lambda and here I'm going to pick up +just the product of the factor + + align:start position:0% +just the product of the factor + + + align:start position:0% +just the product of the factor +so x1 factorial all the way to X n + + align:start position:0% +so x1 factorial all the way to X n + + + align:start position:0% +so x1 factorial all the way to X n +factorial then I get lambda the sum of + + align:start position:0% +factorial then I get lambda the sum of + + + align:start position:0% +factorial then I get lambda the sum of +the X I sorry those are little exercise + + align:start position:0% +the X I sorry those are little exercise + + + align:start position:0% +the X I sorry those are little exercise +e to the minus s and lambda okay so that + + align:start position:0% +e to the minus s and lambda okay so that + + + align:start position:0% +e to the minus s and lambda okay so that +might be freaky at this point but + + align:start position:0% +might be freaky at this point but + + + align:start position:0% +might be freaky at this point but +remember this is a function we will be + + align:start position:0% +remember this is a function we will be + + + align:start position:0% +remember this is a function we will be +maximizing and the denominator here does + + align:start position:0% +maximizing and the denominator here does + + + align:start position:0% +maximizing and the denominator here does +not depend on lambda so we knew that + + align:start position:0% +not depend on lambda so we knew that + + + align:start position:0% +not depend on lambda so we knew that +maximizing this function with this + + align:start position:0% +maximizing this function with this + + + align:start position:0% +maximizing this function with this +denominator or any other denominator + + align:start position:0% +denominator or any other denominator + + + align:start position:0% +denominator or any other denominator +including one will give me the same arc + + align:start position:0% +including one will give me the same arc + + + align:start position:0% +including one will give me the same arc +max so it won't be a problem for me + + align:start position:0% +max so it won't be a problem for me + + + align:start position:0% +max so it won't be a problem for me +as long as it does not depend on lambda + + align:start position:0% +as long as it does not depend on lambda + + + align:start position:0% +as long as it does not depend on lambda +this thing is gonna go away okay so in + + align:start position:0% +this thing is gonna go away okay so in + + + align:start position:0% +this thing is gonna go away okay so in +the continuous case the likelihood I + + align:start position:0% +the continuous case the likelihood I + + + align:start position:0% +the continuous case the likelihood I +cannot write so if I would write the + + align:start position:0% +cannot write so if I would write the + + + align:start position:0% +cannot write so if I would write the +likelihood like this in the continuous + + align:start position:0% +likelihood like this in the continuous + + + align:start position:0% +likelihood like this in the continuous +case this one would be equal to what 0 + + align:start position:0% +case this one would be equal to what 0 + + + align:start position:0% +case this one would be equal to what 0 +right so it's not very helpful and so + + align:start position:0% +right so it's not very helpful and so + + + align:start position:0% +right so it's not very helpful and so +what we do is we define the likelihood + + align:start position:0% +what we do is we define the likelihood + + + align:start position:0% +what we do is we define the likelihood +as the product of the f of theta X I now + + align:start position:0% +as the product of the f of theta X I now + + + align:start position:0% +as the product of the f of theta X I now +that would be a jump if I told you well + + align:start position:0% +that would be a jump if I told you well + + + align:start position:0% +that would be a jump if I told you well +just define it like that and go home and + + align:start position:0% +just define it like that and go home and + + + align:start position:0% +just define it like that and go home and +don't discuss it but we know that this + + align:start position:0% +don't discuss it but we know that this + + + align:start position:0% +don't discuss it but we know that this +is exactly what's coming from the well + + align:start position:0% +is exactly what's coming from the well + + + align:start position:0% +is exactly what's coming from the well +actually I think I erased it it was just + + align:start position:0% +actually I think I erased it it was just + + + align:start position:0% +actually I think I erased it it was just +behind so it this was exactly what was + + align:start position:0% +behind so it this was exactly what was + + + align:start position:0% +behind so it this was exactly what was +coming from the KL divergence estimated + + align:start position:0% +coming from the KL divergence estimated + + + align:start position:0% +coming from the KL divergence estimated +right the thing that I showed you if we + + align:start position:0% +right the thing that I showed you if we + + + align:start position:0% +right the thing that I showed you if we +want to follow this strategy which + + align:start position:0% +want to follow this strategy which + + + align:start position:0% +want to follow this strategy which +consists in estimating the KL divergence + + align:start position:0% +consists in estimating the KL divergence + + + align:start position:0% +consists in estimating the KL divergence +and minimizing it is exactly doing this + + align:start position:0% +and minimizing it is exactly doing this + + + align:start position:0% +and minimizing it is exactly doing this +alright so in the gaussian case well + + align:start position:0% +alright so in the gaussian case well + + + align:start position:0% +alright so in the gaussian case well +let's write it so in the gaussian case + + align:start position:0% +let's write it so in the gaussian case + + + align:start position:0% +let's write it so in the gaussian case +let's see what the likelihood looks like + + align:start position:0% + + + + align:start position:0% + +okay so if I have a Gaussian experiment + + align:start position:0% +okay so if I have a Gaussian experiment + + + align:start position:0% +okay so if I have a Gaussian experiment +here did I actually write it okay so I'm + + align:start position:0% +here did I actually write it okay so I'm + + + align:start position:0% +here did I actually write it okay so I'm +gonna write I'm gonna take mu and Sigma + + align:start position:0% +gonna write I'm gonna take mu and Sigma + + + align:start position:0% +gonna write I'm gonna take mu and Sigma +as being two parameters so that means + + align:start position:0% +as being two parameters so that means + + + align:start position:0% +as being two parameters so that means +that my sample space is gonna be what + + align:start position:0% + + + + align:start position:0% + +well my sample space is still are all + + align:start position:0% +well my sample space is still are all + + + align:start position:0% +well my sample space is still are all +right those are just my observations but + + align:start position:0% +right those are just my observations but + + + align:start position:0% +right those are just my observations but +then I'm gonna have n Mu Sigma squared + + align:start position:0% +then I'm gonna have n Mu Sigma squared + + + align:start position:0% +then I'm gonna have n Mu Sigma squared +and the parameters of interest are mu in + + align:start position:0% +and the parameters of interest are mu in + + + align:start position:0% +and the parameters of interest are mu in +R and Sigma squared and say zero + + align:start position:0% +R and Sigma squared and say zero + + + align:start position:0% +R and Sigma squared and say zero +infinity okay so that's my Gaussian + + align:start position:0% +infinity okay so that's my Gaussian + + + align:start position:0% +infinity okay so that's my Gaussian +model yes no there's no I mean there's + + align:start position:0% +model yes no there's no I mean there's + + + align:start position:0% +model yes no there's no I mean there's +no difference yeah I think the all the + + align:start position:0% +no difference yeah I think the all the + + + align:start position:0% +no difference yeah I think the all the +slides I put the curly bracket and I'm + + align:start position:0% +slides I put the curly bracket and I'm + + + align:start position:0% +slides I put the curly bracket and I'm +just being lazy I just like those + + align:start position:0% +just being lazy I just like those + + + align:start position:0% +just being lazy I just like those +concave parentheses all right so so + + align:start position:0% +concave parentheses all right so so + + + align:start position:0% +concave parentheses all right so so +let's write it so the definition L x1 X + + align:start position:0% +let's write it so the definition L x1 X + + + align:start position:0% +let's write it so the definition L x1 X +N and now I have two parameters mu and + + align:start position:0% +N and now I have two parameters mu and + + + align:start position:0% +N and now I have two parameters mu and +Sigma squared we said by definition is + + align:start position:0% +Sigma squared we said by definition is + + + align:start position:0% +Sigma squared we said by definition is +the product from I equal 1 to N of F + + align:start position:0% +the product from I equal 1 to N of F + + + align:start position:0% +the product from I equal 1 to N of F +theta of a little X I now think about it + + align:start position:0% +theta of a little X I now think about it + + + align:start position:0% +theta of a little X I now think about it +here we always had an extra line right + + align:start position:0% +here we always had an extra line right + + + align:start position:0% +here we always had an extra line right +the line was to say that the definition + + align:start position:0% +the line was to say that the definition + + + align:start position:0% +the line was to say that the definition +was the probability that they were all + + align:start position:0% +was the probability that they were all + + + align:start position:0% +was the probability that they were all +equal to each other + + align:start position:0% +equal to each other + + + align:start position:0% +equal to each other +that was the joint probability and here + + align:start position:0% +that was the joint probability and here + + + align:start position:0% +that was the joint probability and here +I could actually have a line that says + + align:start position:0% +I could actually have a line that says + + + align:start position:0% +I could actually have a line that says +it's the joint probability distribution + + align:start position:0% +it's the joint probability distribution + + + align:start position:0% +it's the joint probability distribution +of the x i's and if it's not independent + + align:start position:0% +of the x i's and if it's not independent + + + align:start position:0% +of the x i's and if it's not independent +it's not gonna be the product but again + + align:start position:0% +it's not gonna be the product but again + + + align:start position:0% +it's not gonna be the product but again +since we're only dealing with the + + align:start position:0% +since we're only dealing with the + + + align:start position:0% +since we're only dealing with the +dependent observations in the scope of + + align:start position:0% +dependent observations in the scope of + + + align:start position:0% +dependent observations in the scope of +this class this is the only definition + + align:start position:0% +this class this is the only definition + + + align:start position:0% +this class this is the only definition +we're gonna be using ok and actually + + align:start position:0% +we're gonna be using ok and actually + + + align:start position:0% +we're gonna be using ok and actually +from here on I will literally skip this + + align:start position:0% +from here on I will literally skip this + + + align:start position:0% +from here on I will literally skip this +this step when I when I talk about + + align:start position:0% +this step when I when I talk about + + + align:start position:0% +this step when I when I talk about +discrete ones as well because they're + + align:start position:0% +discrete ones as well because they're + + + align:start position:0% +discrete ones as well because they're +also independent agreed so we start with + + align:start position:0% +also independent agreed so we start with + + + align:start position:0% +also independent agreed so we start with +this which we agreed was the definition + + align:start position:0% +this which we agreed was the definition + + + align:start position:0% +this which we agreed was the definition +for this particular case and so + + align:start position:0% +for this particular case and so + + + align:start position:0% +for this particular case and so +all of you know by heart with the + + align:start position:0% +all of you know by heart with the + + + align:start position:0% +all of you know by heart with the +density of a sorry that's not data I + + align:start position:0% +density of a sorry that's not data I + + + align:start position:0% +density of a sorry that's not data I +should write it mu sigma squared and so + + align:start position:0% +should write it mu sigma squared and so + + + align:start position:0% +should write it mu sigma squared and so +you need you need to understand what + + align:start position:0% +you need you need to understand what + + + align:start position:0% +you need you need to understand what +this density is and it's prob for a + + align:start position:0% +this density is and it's prob for a + + + align:start position:0% +this density is and it's prob for a +product of 1 over Sigma square root 2 pi + + align:start position:0% +product of 1 over Sigma square root 2 pi + + + align:start position:0% +product of 1 over Sigma square root 2 pi +times exponential minus X I minus mu + + align:start position:0% +times exponential minus X I minus mu + + + align:start position:0% +times exponential minus X I minus mu +squared divided by 2 Sigma squared ok + + align:start position:0% +squared divided by 2 Sigma squared ok + + + align:start position:0% +squared divided by 2 Sigma squared ok +that's the Gaussian density with + + align:start position:0% +that's the Gaussian density with + + + align:start position:0% +that's the Gaussian density with +parameters mu and Sigma squared I just + + align:start position:0% +parameters mu and Sigma squared I just + + + align:start position:0% +parameters mu and Sigma squared I just +plugged in this thing which I don't give + + align:start position:0% +plugged in this thing which I don't give + + + align:start position:0% +plugged in this thing which I don't give +you so you just have to trust me it's + + align:start position:0% +you so you just have to trust me it's + + + align:start position:0% +you so you just have to trust me it's +all over any book certainly I mean you + + align:start position:0% +all over any book certainly I mean you + + + align:start position:0% +all over any book certainly I mean you +can find it you I will give it to you + + align:start position:0% +can find it you I will give it to you + + + align:start position:0% +can find it you I will give it to you +and again you're not expected to know it + + align:start position:0% +and again you're not expected to know it + + + align:start position:0% +and again you're not expected to know it +by heart though if you do your homework + + align:start position:0% +by heart though if you do your homework + + + align:start position:0% +by heart though if you do your homework +every week without wanting to you will + + align:start position:0% +every week without wanting to you will + + + align:start position:0% +every week without wanting to you will +definitely use some of your brain to + + align:start position:0% +definitely use some of your brain to + + + align:start position:0% +definitely use some of your brain to +remember that thing ok and so now well I + + align:start position:0% +remember that thing ok and so now well I + + + align:start position:0% +remember that thing ok and so now well I +have a I have this constant in front + + align:start position:0% +have a I have this constant in front + + + align:start position:0% +have a I have this constant in front +right 1 over Sigma square root 2 pi that + + align:start position:0% +right 1 over Sigma square root 2 pi that + + + align:start position:0% +right 1 over Sigma square root 2 pi that +can pull out so I get 1 over Sigma + + align:start position:0% +can pull out so I get 1 over Sigma + + + align:start position:0% +can pull out so I get 1 over Sigma +square root 2 pi the power N and then I + + align:start position:0% +square root 2 pi the power N and then I + + + align:start position:0% +square root 2 pi the power N and then I +have the product of Exponential's which + + align:start position:0% +have the product of Exponential's which + + + align:start position:0% +have the product of Exponential's which +we know is the exponential of the sum so + + align:start position:0% +we know is the exponential of the sum so + + + align:start position:0% +we know is the exponential of the sum so +this is equal to exponential minus and + + align:start position:0% +this is equal to exponential minus and + + + align:start position:0% +this is equal to exponential minus and +here I'm going to put the 1 over 2 Sigma + + align:start position:0% +here I'm going to put the 1 over 2 Sigma + + + align:start position:0% +here I'm going to put the 1 over 2 Sigma +squared outside the sum + + align:start position:0% + + + + align:start position:0% + +okay and so that's how this guy shows up + + align:start position:0% +okay and so that's how this guy shows up + + + align:start position:0% +okay and so that's how this guy shows up +just a product of the density is + + align:start position:0% +just a product of the density is + + + align:start position:0% +just a product of the density is +evaluated at respectively x1 to xn okay + + align:start position:0% +evaluated at respectively x1 to xn okay + + + align:start position:0% +evaluated at respectively x1 to xn okay +any question about computing those + + align:start position:0% +any question about computing those + + + align:start position:0% +any question about computing those +likelihoods yes oh that's a typo thank + + align:start position:0% +likelihoods yes oh that's a typo thank + + + align:start position:0% +likelihoods yes oh that's a typo thank +you because I just took it from probably + + align:start position:0% +you because I just took it from probably + + + align:start position:0% +you because I just took it from probably +the previous thing so those are actually + + align:start position:0% +the previous thing so those are actually + + + align:start position:0% +the previous thing so those are actually +should be okay thank you for noting that + + align:start position:0% +should be okay thank you for noting that + + + align:start position:0% +should be okay thank you for noting that +one + + align:start position:0% +one + + + align:start position:0% +one +so this line should say for any X 1 to X + + align:start position:0% +so this line should say for any X 1 to X + + + align:start position:0% +so this line should say for any X 1 to X +n in R to the N thank you good catch any + + align:start position:0% +n in R to the N thank you good catch any + + + align:start position:0% +n in R to the N thank you good catch any +other question all right so that's + + align:start position:0% +other question all right so that's + + + align:start position:0% +other question all right so that's +really a to the N right my sample space + + align:start position:0% +really a to the N right my sample space + + + align:start position:0% +really a to the N right my sample space +always okay so what is maximum + + align:start position:0% +always okay so what is maximum + + + align:start position:0% +always okay so what is maximum +likelihood estimation well again if you + + align:start position:0% +likelihood estimation well again if you + + + align:start position:0% +likelihood estimation well again if you +go back to the estimate that we got the + + align:start position:0% +go back to the estimate that we got the + + + align:start position:0% +go back to the estimate that we got the +estimation strategy which consisted in + + align:start position:0% +estimation strategy which consisted in + + + align:start position:0% +estimation strategy which consisted in +replacing expectation with respect to + + align:start position:0% +replacing expectation with respect to + + + align:start position:0% +replacing expectation with respect to +theta star by average of the data in the + + align:start position:0% +theta star by average of the data in the + + + align:start position:0% +theta star by average of the data in the +KL divergence we would try to maximize + + align:start position:0% +KL divergence we would try to maximize + + + align:start position:0% +KL divergence we would try to maximize +not this guy but this guy right the the + + align:start position:0% +not this guy but this guy right the the + + + align:start position:0% +not this guy but this guy right the the +thing that we actually plugged in were + + align:start position:0% +thing that we actually plugged in were + + + align:start position:0% +thing that we actually plugged in were +not any small exercise we're actually + + align:start position:0% +not any small exercise we're actually + + + align:start position:0% +not any small exercise we're actually +the random variables capital X I so the + + align:start position:0% +the random variables capital X I so the + + + align:start position:0% +the random variables capital X I so the +maximum likelihood estimator is actually + + align:start position:0% +maximum likelihood estimator is actually + + + align:start position:0% +maximum likelihood estimator is actually +taking the likelihood which is a + + align:start position:0% +taking the likelihood which is a + + + align:start position:0% +taking the likelihood which is a +function of little X's and now the + + align:start position:0% +function of little X's and now the + + + align:start position:0% +function of little X's and now the +values at which it estimates it look at + + align:start position:0% +values at which it estimates it look at + + + align:start position:0% +values at which it estimates it look at +it is actually the capital X is my data + + align:start position:0% +it is actually the capital X is my data + + + align:start position:0% +it is actually the capital X is my data +so it looks at this function at at the + + align:start position:0% +so it looks at this function at at the + + + align:start position:0% +so it looks at this function at at the +data and at the parameters theta that's + + align:start position:0% +data and at the parameters theta that's + + + align:start position:0% +data and at the parameters theta that's +what the like so that's the first thing + + align:start position:0% +what the like so that's the first thing + + + align:start position:0% +what the like so that's the first thing +and then the maximum likelihood + + align:start position:0% +and then the maximum likelihood + + + align:start position:0% +and then the maximum likelihood +estimator is maximizing this okay so in + + align:start position:0% +estimator is maximizing this okay so in + + + align:start position:0% +estimator is maximizing this okay so in +a way what it does is it's sort of it's + + align:start position:0% +a way what it does is it's sort of it's + + + align:start position:0% +a way what it does is it's sort of it's +a function that couples together + + align:start position:0% +a function that couples together + + + align:start position:0% +a function that couples together +the data capital X 1 to capital X n with + + align:start position:0% +the data capital X 1 to capital X n with + + + align:start position:0% +the data capital X 1 to capital X n with +the parameter theta and just now tries + + align:start position:0% +the parameter theta and just now tries + + + align:start position:0% +the parameter theta and just now tries +to maximize it + + align:start position:0% +to maximize it + + + align:start position:0% +to maximize it +okay so just if this is just a little + + align:start position:0% +okay so just if this is just a little + + + align:start position:0% +okay so just if this is just a little +hard for you to to get the likelihood is + + align:start position:0% +hard for you to to get the likelihood is + + + align:start position:0% +hard for you to to get the likelihood is +formally defined as a function of X + + align:start position:0% +formally defined as a function of X + + + align:start position:0% +formally defined as a function of X +right like when I write f of X f of + + align:start position:0% +right like when I write f of X f of + + + align:start position:0% +right like when I write f of X f of +little X I define it like that but + + align:start position:0% +little X I define it like that but + + + align:start position:0% +little X I define it like that but +really the only arguments at which the + + align:start position:0% +really the only arguments at which the + + + align:start position:0% +really the only arguments at which the +only X arguments were going to evaluate + + align:start position:0% +only X arguments were going to evaluate + + + align:start position:0% +only X arguments were going to evaluate +this function adds are always the random + + align:start position:0% +this function adds are always the random + + + align:start position:0% +this function adds are always the random +variable which is the data so if you + + align:start position:0% +variable which is the data so if you + + + align:start position:0% +variable which is the data so if you +want you can think of it as those guys + + align:start position:0% +want you can think of it as those guys + + + align:start position:0% +want you can think of it as those guys +being not parameters of this function + + align:start position:0% +being not parameters of this function + + + align:start position:0% +being not parameters of this function +but really random variables themselves + + align:start position:0% +but really random variables themselves + + + align:start position:0% +but really random variables themselves +directly okay like this is it is there + + align:start position:0% +directly okay like this is it is there + + + align:start position:0% +directly okay like this is it is there +any question so those are going to be + + align:start position:0% +any question so those are going to be + + + align:start position:0% +any question so those are going to be +known once you have right so is it's + + align:start position:0% +known once you have right so is it's + + + align:start position:0% +known once you have right so is it's +always the same thing in stats you first + + align:start position:0% +always the same thing in stats you first + + + align:start position:0% +always the same thing in stats you first +design your estimator as a function of + + align:start position:0% +design your estimator as a function of + + + align:start position:0% +design your estimator as a function of +random variables and then once you get + + align:start position:0% +random variables and then once you get + + + align:start position:0% +random variables and then once you get +data you just plug it in but we want to + + align:start position:0% +data you just plug it in but we want to + + + align:start position:0% +data you just plug it in but we want to +think of them as being random variables + + align:start position:0% +think of them as being random variables + + + align:start position:0% +think of them as being random variables +because we're going to we want to + + align:start position:0% +because we're going to we want to + + + align:start position:0% +because we're going to we want to +understand what the fluctuations are so + + align:start position:0% +understand what the fluctuations are so + + + align:start position:0% +understand what the fluctuations are so +we're gonna keep them as random variable + + align:start position:0% +we're gonna keep them as random variable + + + align:start position:0% +we're gonna keep them as random variable +for as long as we can we're gonna spit + + align:start position:0% +for as long as we can we're gonna spit + + + align:start position:0% +for as long as we can we're gonna spit +out the estimator as a function of the + + align:start position:0% +out the estimator as a function of the + + + align:start position:0% +out the estimator as a function of the +random variables and then when we want + + align:start position:0% +random variables and then when we want + + + align:start position:0% +random variables and then when we want +to compute it from data we're just gonna + + align:start position:0% +to compute it from data we're just gonna + + + align:start position:0% +to compute it from data we're just gonna +plug it in okay so keep the random + + align:start position:0% +plug it in okay so keep the random + + + align:start position:0% +plug it in okay so keep the random +variables for as long as you can unless + + align:start position:0% +variables for as long as you can unless + + + align:start position:0% +variables for as long as you can unless +I give you numbers actual numbers just + + align:start position:0% +I give you numbers actual numbers just + + + align:start position:0% +I give you numbers actual numbers just +those are random variables okay so there + + align:start position:0% +those are random variables okay so there + + + align:start position:0% +those are random variables okay so there +might be some confusion if you've seen + + align:start position:0% +might be some confusion if you've seen + + + align:start position:0% +might be some confusion if you've seen +any stats class sometimes there's a + + align:start position:0% +any stats class sometimes there's a + + + align:start position:0% +any stats class sometimes there's a +notation which says oh the realization + + align:start position:0% +notation which says oh the realization + + + align:start position:0% +notation which says oh the realization +of the random variables are lowercase + + align:start position:0% +of the random variables are lowercase + + + align:start position:0% +of the random variables are lowercase +versions of the original random + + align:start position:0% +versions of the original random + + + align:start position:0% +versions of the original random +variables right so a lowercase X should + + align:start position:0% +variables right so a lowercase X should + + + align:start position:0% +variables right so a lowercase X should +be thought as the realization of the + + align:start position:0% +be thought as the realization of the + + + align:start position:0% +be thought as the realization of the +uppercase X this is not the case here + + align:start position:0% +uppercase X this is not the case here + + + align:start position:0% +uppercase X this is not the case here +when I write this it's the same way as I + + align:start position:0% +when I write this it's the same way as I + + + align:start position:0% +when I write this it's the same way as I +write f of X is equal to x squared right + + align:start position:0% +write f of X is equal to x squared right + + + align:start position:0% +write f of X is equal to x squared right +it's just an argument of a function that + + align:start position:0% +it's just an argument of a function that + + + align:start position:0% +it's just an argument of a function that +I want to define okay so those are just + + align:start position:0% +I want to define okay so those are just + + + align:start position:0% +I want to define okay so those are just +generic X so if you correct the typo + + align:start position:0% +generic X so if you correct the typo + + + align:start position:0% +generic X so if you correct the typo +that I have this should say that this + + align:start position:0% +that I have this should say that this + + + align:start position:0% +that I have this should say that this +should be for any X in X I'm just + + align:start position:0% +should be for any X in X I'm just + + + align:start position:0% +should be for any X in X I'm just +describing a function and now the only + + align:start position:0% +describing a function and now the only + + + align:start position:0% +describing a function and now the only +place at which I'm interesting in + + align:start position:0% +place at which I'm interesting in + + + align:start position:0% +place at which I'm interesting in +evaluating that function at least for + + align:start position:0% +evaluating that function at least for + + + align:start position:0% +evaluating that function at least for +those first end arguments is at the + + align:start position:0% +those first end arguments is at the + + + align:start position:0% +those first end arguments is at the +capital + + align:start position:0% +capital + + + align:start position:0% +capital +observations random variables that I + + align:start position:0% +observations random variables that I + + + align:start position:0% +observations random variables that I +have okay so there's actually texts + + align:start position:0% +have okay so there's actually texts + + + align:start position:0% +have okay so there's actually texts +there's actually people doing research + + align:start position:0% +there's actually people doing research + + + align:start position:0% +there's actually people doing research +on when does the maximum likelihood + + align:start position:0% +on when does the maximum likelihood + + + align:start position:0% +on when does the maximum likelihood +estimator exist all right and that + + align:start position:0% +estimator exist all right and that + + + align:start position:0% +estimator exist all right and that +happens when you have infinite sets X's + + align:start position:0% +happens when you have infinite sets X's + + + align:start position:0% +happens when you have infinite sets X's +sorry infinite sets Thetas are or and + + align:start position:0% +sorry infinite sets Thetas are or and + + + align:start position:0% +sorry infinite sets Thetas are or and +and this thing can divert there's no + + align:start position:0% +and this thing can divert there's no + + + align:start position:0% +and this thing can divert there's no +global maximum there's crazy things that + + align:start position:0% +global maximum there's crazy things that + + + align:start position:0% +global maximum there's crazy things that +might happen and so we're actually + + align:start position:0% +might happen and so we're actually + + + align:start position:0% +might happen and so we're actually +always going to be in a case where this + + align:start position:0% +always going to be in a case where this + + + align:start position:0% +always going to be in a case where this +maximum likelihood estimator exists and + + align:start position:0% +maximum likelihood estimator exists and + + + align:start position:0% +maximum likelihood estimator exists and +if it doesn't then it means that you + + align:start position:0% +if it doesn't then it means that you + + + align:start position:0% +if it doesn't then it means that you +actually need to restrict your parameter + + align:start position:0% +actually need to restrict your parameter + + + align:start position:0% +actually need to restrict your parameter +space capital theta to something smaller + + align:start position:0% +space capital theta to something smaller + + + align:start position:0% +space capital theta to something smaller +otherwise it won't exist okay so another + + align:start position:0% +otherwise it won't exist okay so another + + + align:start position:0% +otherwise it won't exist okay so another +thing is the log likelihood estimator so + + align:start position:0% +thing is the log likelihood estimator so + + + align:start position:0% +thing is the log likelihood estimator so +it is still the likelihood estimator we + + align:start position:0% +it is still the likelihood estimator we + + + align:start position:0% +it is still the likelihood estimator we +solved for that maximizing a function or + + align:start position:0% +solved for that maximizing a function or + + + align:start position:0% +solved for that maximizing a function or +maximizing log of this function is the + + align:start position:0% +maximizing log of this function is the + + + align:start position:0% +maximizing log of this function is the +same thing because the log function is + + align:start position:0% +same thing because the log function is + + + align:start position:0% +same thing because the log function is +increasing so the same thing is + + align:start position:0% +increasing so the same thing is + + + align:start position:0% +increasing so the same thing is +maximizing a function or maximizing I + + align:start position:0% +maximizing a function or maximizing I + + + align:start position:0% +maximizing a function or maximizing I +don't know exponential of this function + + align:start position:0% +don't know exponential of this function + + + align:start position:0% +don't know exponential of this function +every time I take an increasing function + + align:start position:0% +every time I take an increasing function + + + align:start position:0% +every time I take an increasing function +it's actually the same thing maximizing + + align:start position:0% +it's actually the same thing maximizing + + + align:start position:0% +it's actually the same thing maximizing +a function or maximizing 10 times this + + align:start position:0% +a function or maximizing 10 times this + + + align:start position:0% +a function or maximizing 10 times this +function is the same thing so the + + align:start position:0% +function is the same thing so the + + + align:start position:0% +function is the same thing so the +function X maps to 10 times ax is + + align:start position:0% +function X maps to 10 times ax is + + + align:start position:0% +function X maps to 10 times ax is +increasing and so the log why do we talk + + align:start position:0% +increasing and so the log why do we talk + + + align:start position:0% +increasing and so the log why do we talk +about log likelihood rather than + + align:start position:0% +about log likelihood rather than + + + align:start position:0% +about log likelihood rather than +likelihood so the log of likelihood is + + align:start position:0% +likelihood so the log of likelihood is + + + align:start position:0% +likelihood so the log of likelihood is +really just I mean the log likelihood is + + align:start position:0% +really just I mean the log likelihood is + + + align:start position:0% +really just I mean the log likelihood is +the log of the likelihood and the reason + + align:start position:0% +the log of the likelihood and the reason + + + align:start position:0% +the log of the likelihood and the reason +is exactly for this kind of reasons + + align:start position:0% +is exactly for this kind of reasons + + + align:start position:0% +is exactly for this kind of reasons +remember that was my likelihood right + + align:start position:0% +remember that was my likelihood right + + + align:start position:0% +remember that was my likelihood right +and I want to maximize it and it turns + + align:start position:0% +and I want to maximize it and it turns + + + align:start position:0% +and I want to maximize it and it turns +out that in stats there's a lot of of + + align:start position:0% +out that in stats there's a lot of of + + + align:start position:0% +out that in stats there's a lot of of +distributions that look like exponential + + align:start position:0% +distributions that look like exponential + + + align:start position:0% +distributions that look like exponential +of something so I I might as well just + + align:start position:0% +of something so I I might as well just + + + align:start position:0% +of something so I I might as well just +remove the exponential by taking the log + + align:start position:0% +remove the exponential by taking the log + + + align:start position:0% +remove the exponential by taking the log +okay so once I have this guy I can take + + align:start position:0% +okay so once I have this guy I can take + + + align:start position:0% +okay so once I have this guy I can take +the log this is something to a power of + + align:start position:0% +the log this is something to a power of + + + align:start position:0% +the log this is something to a power of +something if I take the log it's gonna + + align:start position:0% +something if I take the log it's gonna + + + align:start position:0% +something if I take the log it's gonna +look better for me I have this thing + + align:start position:0% +look better for me I have this thing + + + align:start position:0% +look better for me I have this thing +well I have another one somewhere I + + align:start position:0% +well I have another one somewhere I + + + align:start position:0% +well I have another one somewhere I +think where I had the puesto whoever the + + align:start position:0% +think where I had the puesto whoever the + + + align:start position:0% +think where I had the puesto whoever the +crystal the person was going so the + + align:start position:0% +crystal the person was going so the + + + align:start position:0% +crystal the person was going so the +person was the same thing if I took the + + align:start position:0% +person was the same thing if I took the + + + align:start position:0% +person was the same thing if I took the +log because I had a power that would + + align:start position:0% +log because I had a power that would + + + align:start position:0% +log because I had a power that would +make my life easier so the log is not + + align:start position:0% +make my life easier so the log is not + + + align:start position:0% +make my life easier so the log is not +doesn't have any particular intrinsic + + align:start position:0% +doesn't have any particular intrinsic + + + align:start position:0% +doesn't have any particular intrinsic +notion except that it's just more + + align:start position:0% +notion except that it's just more + + + align:start position:0% +notion except that it's just more +convenient now that being said if you + + align:start position:0% +convenient now that being said if you + + + align:start position:0% +convenient now that being said if you +think about Max + + align:start position:0% +think about Max + + + align:start position:0% +think about Max +amazing the KL the original formulation + + align:start position:0% +amazing the KL the original formulation + + + align:start position:0% +amazing the KL the original formulation +but we actually removed the log right if + + align:start position:0% +but we actually removed the log right if + + + align:start position:0% +but we actually removed the log right if +we come back to the KL thing where is my + + align:start position:0% +we come back to the KL thing where is my + + + align:start position:0% +we come back to the KL thing where is my +key L sorry right that was maximizing + + align:start position:0% +key L sorry right that was maximizing + + + align:start position:0% +key L sorry right that was maximizing +the sum of the logs of the PI's and so + + align:start position:0% +the sum of the logs of the PI's and so + + + align:start position:0% +the sum of the logs of the PI's and so +then we worked at it by saying that the + + align:start position:0% +then we worked at it by saying that the + + + align:start position:0% +then we worked at it by saying that the +sum of the logs was max this maximizing + + align:start position:0% +sum of the logs was max this maximizing + + + align:start position:0% +sum of the logs was max this maximizing +the sum of the log was the same as + + align:start position:0% +the sum of the log was the same as + + + align:start position:0% +the sum of the log was the same as +maximizing the product but here were + + align:start position:0% +maximizing the product but here were + + + align:start position:0% +maximizing the product but here were +basically log-likelihood is just going + + align:start position:0% +basically log-likelihood is just going + + + align:start position:0% +basically log-likelihood is just going +backwards in this chain of equivalent + + align:start position:0% +backwards in this chain of equivalent + + + align:start position:0% +backwards in this chain of equivalent +suits and that's just because the + + align:start position:0% +suits and that's just because the + + + align:start position:0% +suits and that's just because the +original formulation was already + + align:start position:0% +original formulation was already + + + align:start position:0% +original formulation was already +convenient so we went to find the + + align:start position:0% +convenient so we went to find the + + + align:start position:0% +convenient so we went to find the +likelihood and then coming back to our + + align:start position:0% +likelihood and then coming back to our + + + align:start position:0% +likelihood and then coming back to our +original estimation strategy right so + + align:start position:0% +original estimation strategy right so + + + align:start position:0% +original estimation strategy right so +look at the Poisson I want to take log + + align:start position:0% +look at the Poisson I want to take log + + + align:start position:0% +look at the Poisson I want to take log +here to make my sum of excise go down + + align:start position:0% +here to make my sum of excise go down + + + align:start position:0% +here to make my sum of excise go down +okay so this is my estimator so right so + + align:start position:0% +okay so this is my estimator so right so + + + align:start position:0% +okay so this is my estimator so right so +the log of L so one thing that you want + + align:start position:0% +the log of L so one thing that you want + + + align:start position:0% +the log of L so one thing that you want +to notice is that the log of L of X 1 X + + align:start position:0% +to notice is that the log of L of X 1 X + + + align:start position:0% +to notice is that the log of L of X 1 X +n data as we said is equal to the sum + + align:start position:0% +n data as we said is equal to the sum + + + align:start position:0% +n data as we said is equal to the sum +from I equal 1 to N of the log of either + + align:start position:0% +from I equal 1 to N of the log of either + + + align:start position:0% +from I equal 1 to N of the log of either +p theta of X I or so that's in the + + align:start position:0% +p theta of X I or so that's in the + + + align:start position:0% +p theta of X I or so that's in the +discrete case and in the continuous case + + align:start position:0% +discrete case and in the continuous case + + + align:start position:0% +discrete case and in the continuous case +is the sum of the log of f theta of X I + + align:start position:0% +is the sum of the log of f theta of X I + + + align:start position:0% +is the sum of the log of f theta of X I +okay + + align:start position:0% +okay + + + align:start position:0% +okay +the beauty of this is that you don't + + align:start position:0% +the beauty of this is that you don't + + + align:start position:0% +the beauty of this is that you don't +have to really understand the difference + + align:start position:0% +have to really understand the difference + + + align:start position:0% +have to really understand the difference +between probability mass function and + + align:start position:0% +between probability mass function and + + + align:start position:0% +between probability mass function and +probability distribution function to + + align:start position:0% +probability distribution function to + + + align:start position:0% +probability distribution function to +implement this whatever you get that's + + align:start position:0% +implement this whatever you get that's + + + align:start position:0% +implement this whatever you get that's +what you plug in okay any questions so + + align:start position:0% +what you plug in okay any questions so + + + align:start position:0% +what you plug in okay any questions so +far + + align:start position:0% +far + + + align:start position:0% +far +all right so shall we do some + + align:start position:0% +all right so shall we do some + + + align:start position:0% +all right so shall we do some +computations and check that actually + + align:start position:0% +computations and check that actually + + + align:start position:0% +computations and check that actually +we've introduced all this stuff + + align:start position:0% +we've introduced all this stuff + + + align:start position:0% +we've introduced all this stuff +complicate functions maximizing KL + + align:start position:0% +complicate functions maximizing KL + + + align:start position:0% +complicate functions maximizing KL +divergence a lot of things so that we + + align:start position:0% +divergence a lot of things so that we + + + align:start position:0% +divergence a lot of things so that we +can spit out again averages alright + + align:start position:0% +can spit out again averages alright + + + align:start position:0% +can spit out again averages alright +that's great we're gonna be able to + + align:start position:0% +that's great we're gonna be able to + + + align:start position:0% +that's great we're gonna be able to +sleep at night and know that there's a + + align:start position:0% +sleep at night and know that there's a + + + align:start position:0% +sleep at night and know that there's a +really powerful mechanism called maximum + + align:start position:0% +really powerful mechanism called maximum + + + align:start position:0% +really powerful mechanism called maximum +likelihood estimator that was actually + + align:start position:0% +likelihood estimator that was actually + + + align:start position:0% +likelihood estimator that was actually +driving and into our intuition without + + align:start position:0% +driving and into our intuition without + + + align:start position:0% +driving and into our intuition without +us knowing okay so + + align:start position:0% +us knowing okay so + + + align:start position:0% +us knowing okay so +let's do this so burn elite trials I + + align:start position:0% +let's do this so burn elite trials I + + + align:start position:0% +let's do this so burn elite trials I +still have it over there okay so + + align:start position:0% +still have it over there okay so + + + align:start position:0% +still have it over there okay so +actually I don't know what well let me + + align:start position:0% +actually I don't know what well let me + + + align:start position:0% +actually I don't know what well let me +write it like that right so it's P over + + align:start position:0% +write it like that right so it's P over + + + align:start position:0% +write it like that right so it's P over +1 minus P X I so sorry some of the + + align:start position:0% +1 minus P X I so sorry some of the + + + align:start position:0% +1 minus P X I so sorry some of the +excise times 1 minus P to the N okay so + + align:start position:0% +excise times 1 minus P to the N okay so + + + align:start position:0% +excise times 1 minus P to the N okay so +now I want to maximize this as a + + align:start position:0% +now I want to maximize this as a + + + align:start position:0% +now I want to maximize this as a +function of P well the first thing we + + align:start position:0% +function of P well the first thing we + + + align:start position:0% +function of P well the first thing we +would want to do is to check that this + + align:start position:0% +would want to do is to check that this + + + align:start position:0% +would want to do is to check that this +function is concave and I'm just gonna + + align:start position:0% +function is concave and I'm just gonna + + + align:start position:0% +function is concave and I'm just gonna +ask you to trust me on this so I don't + + align:start position:0% +ask you to trust me on this so I don't + + + align:start position:0% +ask you to trust me on this so I don't +want sorry some of the excise I only + + align:start position:0% +want sorry some of the excise I only + + + align:start position:0% +want sorry some of the excise I only +want to take the derivative and just go + + align:start position:0% +want to take the derivative and just go + + + align:start position:0% +want to take the derivative and just go +home okay so let's just take the + + align:start position:0% +home okay so let's just take the + + + align:start position:0% +home okay so let's just take the +derivative of this with respect to P + + align:start position:0% +derivative of this with respect to P + + + align:start position:0% +derivative of this with respect to P +actually no this one was more convenient + + align:start position:0% +actually no this one was more convenient + + + align:start position:0% +actually no this one was more convenient +I'm sorry + + align:start position:0% + + + + align:start position:0% + +this one was slightly more convenient + + align:start position:0% +this one was slightly more convenient + + + align:start position:0% +this one was slightly more convenient +okay so now we have let me call this + + align:start position:0% +okay so now we have let me call this + + + align:start position:0% +okay so now we have let me call this +thing so now let me take the log okay so + + align:start position:0% +thing so now let me take the log okay so + + + align:start position:0% +thing so now let me take the log okay so +if I take the log what I get is some of + + align:start position:0% +if I take the log what I get is some of + + + align:start position:0% +if I take the log what I get is some of +the excise times log P plus n minus some + + align:start position:0% +the excise times log P plus n minus some + + + align:start position:0% +the excise times log P plus n minus some +of the excise times log 1 minus P + + align:start position:0% +of the excise times log 1 minus P + + + align:start position:0% +of the excise times log 1 minus P +okay now I take the derivative with + + align:start position:0% +okay now I take the derivative with + + + align:start position:0% +okay now I take the derivative with +respect to P and set it equal to zero + + align:start position:0% +respect to P and set it equal to zero + + + align:start position:0% +respect to P and set it equal to zero +okay so what does that give me it tells + + align:start position:0% +okay so what does that give me it tells + + + align:start position:0% +okay so what does that give me it tells +me that some of the excise divided by P + + align:start position:0% +me that some of the excise divided by P + + + align:start position:0% +me that some of the excise divided by P +minus n some of the X is divided by one + + align:start position:0% +minus n some of the X is divided by one + + + align:start position:0% +minus n some of the X is divided by one +minus P is equal to zero + + align:start position:0% + + + + align:start position:0% + +okay so now I need to solve for P so + + align:start position:0% +okay so now I need to solve for P so + + + align:start position:0% +okay so now I need to solve for P so +let's just do it so what we get is that + + align:start position:0% +let's just do it so what we get is that + + + align:start position:0% +let's just do it so what we get is that +1 minus P some of the excise is equal to + + align:start position:0% +1 minus P some of the excise is equal to + + + align:start position:0% +1 minus P some of the excise is equal to +P and minus some of the excise so that's + + align:start position:0% +P and minus some of the excise so that's + + + align:start position:0% +P and minus some of the excise so that's +P times n minus some of the excise plus + + align:start position:0% +P times n minus some of the excise plus + + + align:start position:0% +P times n minus some of the excise plus +some of the excise so let me put it on + + align:start position:0% +some of the excise so let me put it on + + + align:start position:0% +some of the excise so let me put it on +the right so that P times n is equal to + + align:start position:0% +the right so that P times n is equal to + + + align:start position:0% +the right so that P times n is equal to +some of the excise and that's equivalent + + align:start position:0% +some of the excise and that's equivalent + + + align:start position:0% +some of the excise and that's equivalent +to P actually I should start by putting + + align:start position:0% +to P actually I should start by putting + + + align:start position:0% +to P actually I should start by putting +P hat from here on because I'm already + + align:start position:0% +P hat from here on because I'm already + + + align:start position:0% +P hat from here on because I'm already +solving an equation right and so P hat + + align:start position:0% +solving an equation right and so P hat + + + align:start position:0% +solving an equation right and so P hat +is equal to some of the excise divided + + align:start position:0% +is equal to some of the excise divided + + + align:start position:0% +is equal to some of the excise divided +by n which is my xn bar okay well so + + align:start position:0% +by n which is my xn bar okay well so + + + align:start position:0% +by n which is my xn bar okay well so +model as I said twice mu is gone okay so + + align:start position:0% +model as I said twice mu is gone okay so + + + align:start position:0% +model as I said twice mu is gone okay so +let me rewrite it quickly + + align:start position:0% + + + + align:start position:0% + +okay so Poisson the likelihood in x1 xn + + align:start position:0% +okay so Poisson the likelihood in x1 xn + + + align:start position:0% +okay so Poisson the likelihood in x1 xn +and lambda was equal to lambda to the + + align:start position:0% +and lambda was equal to lambda to the + + + align:start position:0% +and lambda was equal to lambda to the +sum of the X is e to the minus n lambda + + align:start position:0% +sum of the X is e to the minus n lambda + + + align:start position:0% +sum of the X is e to the minus n lambda +divided by X 1 factorial all the way to + + align:start position:0% +divided by X 1 factorial all the way to + + + align:start position:0% +divided by X 1 factorial all the way to +X n factorial so now let me take the log + + align:start position:0% +X n factorial so now let me take the log + + + align:start position:0% +X n factorial so now let me take the log +likelihood that's gonna be equal to what + + align:start position:0% +likelihood that's gonna be equal to what + + + align:start position:0% +likelihood that's gonna be equal to what +it's gonna tell me it's gonna be well + + align:start position:0% +it's gonna tell me it's gonna be well + + + align:start position:0% +it's gonna tell me it's gonna be well +let me get rid of this guy first minus + + align:start position:0% +let me get rid of this guy first minus + + + align:start position:0% +let me get rid of this guy first minus +log of X 1 factorial all the way to X n + + align:start position:0% +log of X 1 factorial all the way to X n + + + align:start position:0% +log of X 1 factorial all the way to X n +factorial that's a constant with respect + + align:start position:0% +factorial that's a constant with respect + + + align:start position:0% +factorial that's a constant with respect +to lambda so + + align:start position:0% +to lambda so + + + align:start position:0% +to lambda so +I'm gonna take the derivative it's gonna + + align:start position:0% +I'm gonna take the derivative it's gonna + + + align:start position:0% +I'm gonna take the derivative it's gonna +go and I'm gonna have plus some of the + + align:start position:0% +go and I'm gonna have plus some of the + + + align:start position:0% +go and I'm gonna have plus some of the +excise Times log lined up and then I'm + + align:start position:0% +excise Times log lined up and then I'm + + + align:start position:0% +excise Times log lined up and then I'm +gonna have minus and lambda okay so now + + align:start position:0% +gonna have minus and lambda okay so now + + + align:start position:0% +gonna have minus and lambda okay so now +let me take the derivative and set it + + align:start position:0% +let me take the derivative and set it + + + align:start position:0% +let me take the derivative and set it +equal to zero so log L partial with + + align:start position:0% +equal to zero so log L partial with + + + align:start position:0% +equal to zero so log L partial with +respect to lambda of log L say lambda + + align:start position:0% +respect to lambda of log L say lambda + + + align:start position:0% +respect to lambda of log L say lambda +equals zero this is equivalent to so + + align:start position:0% +equals zero this is equivalent to so + + + align:start position:0% +equals zero this is equivalent to so +this guy goes this guy gives me some of + + align:start position:0% +this guy goes this guy gives me some of + + + align:start position:0% +this guy goes this guy gives me some of +the X is divided by lambda hat equals n + + align:start position:0% + + + + align:start position:0% + +and so that's equivalent to lambda hat + + align:start position:0% +and so that's equivalent to lambda hat + + + align:start position:0% +and so that's equivalent to lambda hat +is equal to some of the X I divided by n + + align:start position:0% +is equal to some of the X I divided by n + + + align:start position:0% +is equal to some of the X I divided by n +which is xn bar okay take derivative set + + align:start position:0% +which is xn bar okay take derivative set + + + align:start position:0% +which is xn bar okay take derivative set +it equal to zero and just solve it's a + + align:start position:0% +it equal to zero and just solve it's a + + + align:start position:0% +it equal to zero and just solve it's a +very satisfying exercise actually + + align:start position:0% +very satisfying exercise actually + + + align:start position:0% +very satisfying exercise actually +especially when you get the average in + + align:start position:0% +especially when you get the average in + + + align:start position:0% +especially when you get the average in +the end you don't have to think about it + + align:start position:0% +the end you don't have to think about it + + + align:start position:0% +the end you don't have to think about it +forever + + align:start position:0% +forever + + + align:start position:0% +forever +okay the Gaussian model I'm gonna leave + + align:start position:0% +okay the Gaussian model I'm gonna leave + + + align:start position:0% +okay the Gaussian model I'm gonna leave +to you as an exercise okay take the log + + align:start position:0% +to you as an exercise okay take the log + + + align:start position:0% +to you as an exercise okay take the log +to get rid of this pesky exponential and + + align:start position:0% +to get rid of this pesky exponential and + + + align:start position:0% +to get rid of this pesky exponential and +then take the derivative and you should + + align:start position:0% +then take the derivative and you should + + + align:start position:0% +then take the derivative and you should +be fine it's a bit more like it might be + + align:start position:0% +be fine it's a bit more like it might be + + + align:start position:0% +be fine it's a bit more like it might be +one more line than those guys okay so + + align:start position:0% + + + + align:start position:0% + +well actually you need to take the + + align:start position:0% +well actually you need to take the + + + align:start position:0% +well actually you need to take the +gradient in this case don't check the + + align:start position:0% +gradient in this case don't check the + + + align:start position:0% +gradient in this case don't check the +second derivative right now you don't + + align:start position:0% +second derivative right now you don't + + + align:start position:0% +second derivative right now you don't +have to really think about it what do + + align:start position:0% +have to really think about it what do + + + align:start position:0% +have to really think about it what do +you don't want to add yes when I have a + + align:start position:0% +you don't want to add yes when I have a + + + align:start position:0% +you don't want to add yes when I have a +function that's concave and I'm on like + + align:start position:0% +function that's concave and I'm on like + + + align:start position:0% +function that's concave and I'm on like +some infinite interval then it's true + + align:start position:0% +some infinite interval then it's true + + + align:start position:0% +some infinite interval then it's true +that taking the derivative and setting + + align:start position:0% +that taking the derivative and setting + + + align:start position:0% +that taking the derivative and setting +it equal to zero will give me the + + align:start position:0% +it equal to zero will give me the + + + align:start position:0% +it equal to zero will give me the +maximum but again I might have a + + align:start position:0% +maximum but again I might have a + + + align:start position:0% +maximum but again I might have a +function that looks like this now if I'm + + align:start position:0% +function that looks like this now if I'm + + + align:start position:0% +function that looks like this now if I'm +on some finite interval let me go + + align:start position:0% +on some finite interval let me go + + + align:start position:0% +on some finite interval let me go +elsewhere so if I'm on some finite + + align:start position:0% +elsewhere so if I'm on some finite + + + align:start position:0% +elsewhere so if I'm on some finite +interval + + align:start position:0% + + + + align:start position:0% + +and my function looks like this as a + + align:start position:0% +and my function looks like this as a + + + align:start position:0% +and my function looks like this as a +function of theta let's say this is my + + align:start position:0% +function of theta let's say this is my + + + align:start position:0% +function of theta let's say this is my +log likelihood as a function of theta + + align:start position:0% +log likelihood as a function of theta + + + align:start position:0% +log likelihood as a function of theta +then okay there's no place in this + + align:start position:0% +then okay there's no place in this + + + align:start position:0% +then okay there's no place in this +interval let's say this is between 0 & 1 + + align:start position:0% +interval let's say this is between 0 & 1 + + + align:start position:0% +interval let's say this is between 0 & 1 +there's no place in this interval where + + align:start position:0% +there's no place in this interval where + + + align:start position:0% +there's no place in this interval where +the derivative is equal to 0 and if you + + align:start position:0% +the derivative is equal to 0 and if you + + + align:start position:0% +the derivative is equal to 0 and if you +actually try to solve this you will find + + align:start position:0% +actually try to solve this you will find + + + align:start position:0% +actually try to solve this you will find +a solution which is not in the interval + + align:start position:0% +a solution which is not in the interval + + + align:start position:0% +a solution which is not in the interval +0 1 and that's actually how you know + + align:start position:0% +0 1 and that's actually how you know + + + align:start position:0% +0 1 and that's actually how you know +that you probably should not take the + + align:start position:0% +that you probably should not take the + + + align:start position:0% +that you probably should not take the +derivative equal to 0 so don't panic if + + align:start position:0% +derivative equal to 0 so don't panic if + + + align:start position:0% +derivative equal to 0 so don't panic if +you get something that says well the + + align:start position:0% +you get something that says well the + + + align:start position:0% +you get something that says well the +solution is that infinity right if this + + align:start position:0% +solution is that infinity right if this + + + align:start position:0% +solution is that infinity right if this +function keeps going you will find that + + align:start position:0% +function keeps going you will find that + + + align:start position:0% +function keeps going you will find that +the solution you won't be able to find a + + align:start position:0% +the solution you won't be able to find a + + + align:start position:0% +the solution you won't be able to find a +solution + + align:start position:0% +solution + + + align:start position:0% +solution +apart from infinity all right you're + + align:start position:0% +apart from infinity all right you're + + + align:start position:0% +apart from infinity all right you're +gonna see something like 1 over theta + + align:start position:0% +gonna see something like 1 over theta + + + align:start position:0% +gonna see something like 1 over theta +hat is equal to 0 or something like this + + align:start position:0% +hat is equal to 0 or something like this + + + align:start position:0% +hat is equal to 0 or something like this +right so you know that when you found + + align:start position:0% +right so you know that when you found + + + align:start position:0% +right so you know that when you found +this kind of solution you've probably + + align:start position:0% +this kind of solution you've probably + + + align:start position:0% +this kind of solution you've probably +made a mistake at some point and the + + align:start position:0% +made a mistake at some point and the + + + align:start position:0% +made a mistake at some point and the +reason is because the functions that are + + align:start position:0% +reason is because the functions that are + + + align:start position:0% +reason is because the functions that are +like this you don't find the maximum by + + align:start position:0% +like this you don't find the maximum by + + + align:start position:0% +like this you don't find the maximum by +setting the derivative equal to 0 + + align:start position:0% +setting the derivative equal to 0 + + + align:start position:0% +setting the derivative equal to 0 +you actually just find a maximum by + + align:start position:0% +you actually just find a maximum by + + + align:start position:0% +you actually just find a maximum by +saying well it's an increasing function + + align:start position:0% +saying well it's an increasing function + + + align:start position:0% +saying well it's an increasing function +on the interval 0 1 so the maximum must + + align:start position:0% +on the interval 0 1 so the maximum must + + + align:start position:0% +on the interval 0 1 so the maximum must +be attained at 1 ok so here in this case + + align:start position:0% +be attained at 1 ok so here in this case + + + align:start position:0% +be attained at 1 ok so here in this case +that would mean that my maximum would be + + align:start position:0% +that would mean that my maximum would be + + + align:start position:0% +that would mean that my maximum would be +1 my estimator would be 1 which would be + + align:start position:0% +1 my estimator would be 1 which would be + + + align:start position:0% +1 my estimator would be 1 which would be +word so typically here you have a + + align:start position:0% +word so typically here you have a + + + align:start position:0% +word so typically here you have a +function of the x i's so one example + + align:start position:0% +function of the x i's so one example + + + align:start position:0% +function of the x i's so one example +that you will see many times is when + + align:start position:0% +that you will see many times is when + + + align:start position:0% +that you will see many times is when +this guy is the maximum of the x i's + + align:start position:0% +this guy is the maximum of the x i's + + + align:start position:0% +this guy is the maximum of the x i's +okay and in which case the maximum is + + align:start position:0% +okay and in which case the maximum is + + + align:start position:0% +okay and in which case the maximum is +attained here which is the maximum of + + align:start position:0% +attained here which is the maximum of + + + align:start position:0% +attained here which is the maximum of +the Excite okay so just keep in mind + + align:start position:0% +the Excite okay so just keep in mind + + + align:start position:0% +the Excite okay so just keep in mind +what I would recommend is every time + + align:start position:0% +what I would recommend is every time + + + align:start position:0% +what I would recommend is every time +you're trying to take the maximum of a + + align:start position:0% +you're trying to take the maximum of a + + + align:start position:0% +you're trying to take the maximum of a +function just try to plot the function + + align:start position:0% +function just try to plot the function + + + align:start position:0% +function just try to plot the function +in your head it's not too complicated + + align:start position:0% +in your head it's not too complicated + + + align:start position:0% +in your head it's not too complicated +those things are usually squares or + + align:start position:0% +those things are usually squares or + + + align:start position:0% +those things are usually squares or +square roots or logs you know what those + + align:start position:0% +square roots or logs you know what those + + + align:start position:0% +square roots or logs you know what those +functions look like just plot them in + + align:start position:0% +functions look like just plot them in + + + align:start position:0% +functions look like just plot them in +your mind and make sure that you will + + align:start position:0% +your mind and make sure that you will + + + align:start position:0% +your mind and make sure that you will +find a maximum which really goes up and + + align:start position:0% +find a maximum which really goes up and + + + align:start position:0% +find a maximum which really goes up and +then down again if you don't then that + + align:start position:0% +then down again if you don't then that + + + align:start position:0% +then down again if you don't then that +means your maximum is achieved achieved + + align:start position:0% +means your maximum is achieved achieved + + + align:start position:0% +means your maximum is achieved achieved +at the boundary and that's you have to + + align:start position:0% +at the boundary and that's you have to + + + align:start position:0% +at the boundary and that's you have to +think differently to get it okay so the + + align:start position:0% +think differently to get it okay so the + + + align:start position:0% +think differently to get it okay so the +machinery that consistent setting the + + align:start position:0% +machinery that consistent setting the + + + align:start position:0% +machinery that consistent setting the +equal to0 work say 80% of the time at + + align:start position:0% +equal to0 work say 80% of the time at + + + align:start position:0% +equal to0 work say 80% of the time at +some time you have to be careful and + + align:start position:0% +some time you have to be careful and + + + align:start position:0% +some time you have to be careful and +from the context it will be clear that + + align:start position:0% +from the context it will be clear that + + + align:start position:0% +from the context it will be clear that +you had to be careful because you will + + align:start position:0% +you had to be careful because you will + + + align:start position:0% +you had to be careful because you will +find some crazy stuff such as solve one + + align:start position:0% +find some crazy stuff such as solve one + + + align:start position:0% +find some crazy stuff such as solve one +over theta hat is equal to zero okay all + + align:start position:0% +over theta hat is equal to zero okay all + + + align:start position:0% +over theta hat is equal to zero okay all +right so before we conclude I just + + align:start position:0% +right so before we conclude I just + + + align:start position:0% +right so before we conclude I just +wanted to give you some intuition about + + align:start position:0% +wanted to give you some intuition about + + + align:start position:0% +wanted to give you some intuition about +how does the maximum likelihood perform + + align:start position:0% +how does the maximum likelihood perform + + + align:start position:0% +how does the maximum likelihood perform +right so there's something called the + + align:start position:0% +right so there's something called the + + + align:start position:0% +right so there's something called the +Fisher information that essentially + + align:start position:0% +Fisher information that essentially + + + align:start position:0% +Fisher information that essentially +controls how this thing performs and the + + align:start position:0% +controls how this thing performs and the + + + align:start position:0% +controls how this thing performs and the +Fisher information is essentially a + + align:start position:0% +Fisher information is essentially a + + + align:start position:0% +Fisher information is essentially a +second derivative or Hessian so if I'm + + align:start position:0% +second derivative or Hessian so if I'm + + + align:start position:0% +second derivative or Hessian so if I'm +in the one dimensional parameter case + + align:start position:0% +in the one dimensional parameter case + + + align:start position:0% +in the one dimensional parameter case +it's a number it's a second derivative + + align:start position:0% +it's a number it's a second derivative + + + align:start position:0% +it's a number it's a second derivative +if I'm in a multi dimensional case it's + + align:start position:0% +if I'm in a multi dimensional case it's + + + align:start position:0% +if I'm in a multi dimensional case it's +actually a hessian it's a matrix okay so + + align:start position:0% +actually a hessian it's a matrix okay so + + + align:start position:0% +actually a hessian it's a matrix okay so +I'm gonna actually take a notation + + align:start position:0% +I'm gonna actually take a notation + + + align:start position:0% +I'm gonna actually take a notation +little you know curly L of theta to be + + align:start position:0% +little you know curly L of theta to be + + + align:start position:0% +little you know curly L of theta to be +the log-likelihood okay and that's a log + + align:start position:0% +the log-likelihood okay and that's a log + + + align:start position:0% +the log-likelihood okay and that's a log +likelihood for one observation let's + + align:start position:0% +likelihood for one observation let's + + + align:start position:0% +likelihood for one observation let's +call it X generically but think of it as + + align:start position:0% +call it X generically but think of it as + + + align:start position:0% +call it X generically but think of it as +being x1 for example and I don't care of + + align:start position:0% +being x1 for example and I don't care of + + + align:start position:0% +being x1 for example and I don't care of +like summing because I'm actually going + + align:start position:0% +like summing because I'm actually going + + + align:start position:0% +like summing because I'm actually going +to take expectation of this thing so + + align:start position:0% +to take expectation of this thing so + + + align:start position:0% +to take expectation of this thing so +it's not going to be a data-driven + + align:start position:0% +it's not going to be a data-driven + + + align:start position:0% +it's not going to be a data-driven +quantity I'm gonna play with okay so now + + align:start position:0% +quantity I'm gonna play with okay so now + + + align:start position:0% +quantity I'm gonna play with okay so now +I'm going to assume that it is twice + + align:start position:0% +I'm going to assume that it is twice + + + align:start position:0% +I'm going to assume that it is twice +differentiable almost surely because + + align:start position:0% +differentiable almost surely because + + + align:start position:0% +differentiable almost surely because +it's a it's a random function and so now + + align:start position:0% +it's a it's a random function and so now + + + align:start position:0% +it's a it's a random function and so now +I'm gonna just sweep under the rug some + + align:start position:0% +I'm gonna just sweep under the rug some + + + align:start position:0% +I'm gonna just sweep under the rug some +you know technical conditions when this + + align:start position:0% +you know technical conditions when this + + + align:start position:0% +you know technical conditions when this +thing's hold so typically when can i + + align:start position:0% +thing's hold so typically when can i + + + align:start position:0% +thing's hold so typically when can i +permute integral and derivatives and you + + align:start position:0% +permute integral and derivatives and you + + + align:start position:0% +permute integral and derivatives and you +know this kind of stuff that you don't + + align:start position:0% +know this kind of stuff that you don't + + + align:start position:0% +know this kind of stuff that you don't +want to think about okay the rule of + + align:start position:0% +want to think about okay the rule of + + + align:start position:0% +want to think about okay the rule of +thumb is it always works until it + + align:start position:0% +thumb is it always works until it + + + align:start position:0% +thumb is it always works until it +doesn't in which case that probably + + align:start position:0% +doesn't in which case that probably + + + align:start position:0% +doesn't in which case that probably +means you're actually solving some sort + + align:start position:0% +means you're actually solving some sort + + + align:start position:0% +means you're actually solving some sort +of calculus problem because in practice + + align:start position:0% +of calculus problem because in practice + + + align:start position:0% +of calculus problem because in practice +it just doesn't happen all right so the + + align:start position:0% +it just doesn't happen all right so the + + + align:start position:0% +it just doesn't happen all right so the +information the Fisher information is + + align:start position:0% +information the Fisher information is + + + align:start position:0% +information the Fisher information is +the expectations' of the what that's + + align:start position:0% +the expectations' of the what that's + + + align:start position:0% +the expectations' of the what that's +called the outer product so that's the + + align:start position:0% +called the outer product so that's the + + + align:start position:0% +called the outer product so that's the +product of this gradient and the + + align:start position:0% +product of this gradient and the + + + align:start position:0% +product of this gradient and the +gradient transpose so that forms a + + align:start position:0% +gradient transpose so that forms a + + + align:start position:0% +gradient transpose so that forms a +matrix right that's a matrix minus the + + align:start position:0% +matrix right that's a matrix minus the + + + align:start position:0% +matrix right that's a matrix minus the +outer product of the expectations so + + align:start position:0% +outer product of the expectations so + + + align:start position:0% +outer product of the expectations so +that's really what's called the + + align:start position:0% +that's really what's called the + + + align:start position:0% +that's really what's called the +covariance matrix of this vector nabla + + align:start position:0% +covariance matrix of this vector nabla + + + align:start position:0% +covariance matrix of this vector nabla +eval theta which is a random vector + + align:start position:0% +eval theta which is a random vector + + + align:start position:0% +eval theta which is a random vector +because I'm forming the covariance + + align:start position:0% +because I'm forming the covariance + + + align:start position:0% +because I'm forming the covariance +matrix of this thing and the technical + + align:start position:0% +matrix of this thing and the technical + + + align:start position:0% +matrix of this thing and the technical +conditions tells me that actually this + + align:start position:0% +conditions tells me that actually this + + + align:start position:0% +conditions tells me that actually this +guy which depends only on the Hessian is + + align:start position:0% +guy which depends only on the Hessian is + + + align:start position:0% +guy which depends only on the Hessian is +actually equal to negative expectation + + align:start position:0% +actually equal to negative expectation + + + align:start position:0% +actually equal to negative expectation +of the sorry depends on the gradient is + + align:start position:0% +of the sorry depends on the gradient is + + + align:start position:0% +of the sorry depends on the gradient is +actually negative exponential + + align:start position:0% +actually negative exponential + + + align:start position:0% +actually negative exponential +expectation of the Hessian so I can + + align:start position:0% +expectation of the Hessian so I can + + + align:start position:0% +expectation of the Hessian so I can +actually get a quantity that depends on + + align:start position:0% +actually get a quantity that depends on + + + align:start position:0% +actually get a quantity that depends on +the second derivatives only using first + + align:start position:0% +the second derivatives only using first + + + align:start position:0% +the second derivatives only using first +derivatives but the expectation is gonna + + align:start position:0% +derivatives but the expectation is gonna + + + align:start position:0% +derivatives but the expectation is gonna +play a role here and the fact that it's + + align:start position:0% +play a role here and the fact that it's + + + align:start position:0% +play a role here and the fact that it's +a blog and lots of things actually show + + align:start position:0% +a blog and lots of things actually show + + + align:start position:0% +a blog and lots of things actually show +up here and so in this case what I get + + align:start position:0% +up here and so in this case what I get + + + align:start position:0% +up here and so in this case what I get +is that so in the one dimensional case + + align:start position:0% +is that so in the one dimensional case + + + align:start position:0% +is that so in the one dimensional case +then this is just the covariance matrix + + align:start position:0% +then this is just the covariance matrix + + + align:start position:0% +then this is just the covariance matrix +of a one dimensional thing which is just + + align:start position:0% +of a one dimensional thing which is just + + + align:start position:0% +of a one dimensional thing which is just +the variance of itself so the variance + + align:start position:0% +the variance of itself so the variance + + + align:start position:0% +the variance of itself so the variance +of the derivative is actually equal to + + align:start position:0% +of the derivative is actually equal to + + + align:start position:0% +of the derivative is actually equal to +negative this expectation of the second + + align:start position:0% +negative this expectation of the second + + + align:start position:0% +negative this expectation of the second +derivative okay so we'll see that next + + align:start position:0% +derivative okay so we'll see that next + + + align:start position:0% +derivative okay so we'll see that next +time but what I wanted to emphasize with + + align:start position:0% +time but what I wanted to emphasize with + + + align:start position:0% +time but what I wanted to emphasize with +this is that why do we care about this + + align:start position:0% +this is that why do we care about this + + + align:start position:0% +this is that why do we care about this +quantity right that's called the Fisher + + align:start position:0% +quantity right that's called the Fisher + + + align:start position:0% +quantity right that's called the Fisher +information Fisher is the founding + + align:start position:0% +information Fisher is the founding + + + align:start position:0% +information Fisher is the founding +father of modern statistics why did we + + align:start position:0% +father of modern statistics why did we + + + align:start position:0% +father of modern statistics why did we +give this quantity his name well it's + + align:start position:0% +give this quantity his name well it's + + + align:start position:0% +give this quantity his name well it's +because this quantity is actually very + + align:start position:0% +because this quantity is actually very + + + align:start position:0% +because this quantity is actually very +critical what is the second derivative + + align:start position:0% +critical what is the second derivative + + + align:start position:0% +critical what is the second derivative +of a function tell me at the maximum + + align:start position:0% +of a function tell me at the maximum + + + align:start position:0% +of a function tell me at the maximum +well it's telling me how how curved it + + align:start position:0% +well it's telling me how how curved it + + + align:start position:0% +well it's telling me how how curved it +is right if I have a zero second + + align:start position:0% +is right if I have a zero second + + + align:start position:0% +is right if I have a zero second +derivative and basically flat and if I + + align:start position:0% +derivative and basically flat and if I + + + align:start position:0% +derivative and basically flat and if I +have a very high second derivative I'm + + align:start position:0% +have a very high second derivative I'm + + + align:start position:0% +have a very high second derivative I'm +very curvy and when I'm very curvy what + + align:start position:0% +very curvy and when I'm very curvy what + + + align:start position:0% +very curvy and when I'm very curvy what +it means is that very robust to the + + align:start position:0% +it means is that very robust to the + + + align:start position:0% +it means is that very robust to the +estimation errors remember our + + align:start position:0% +estimation errors remember our + + + align:start position:0% +estimation errors remember our +estimation strategy which consisted in + + align:start position:0% +estimation strategy which consisted in + + + align:start position:0% +estimation strategy which consisted in +replacing expectation by averages if I'm + + align:start position:0% +replacing expectation by averages if I'm + + + align:start position:0% +replacing expectation by averages if I'm +extremely curvy I can move a little bit + + align:start position:0% +extremely curvy I can move a little bit + + + align:start position:0% +extremely curvy I can move a little bit +this thing the maximum is not going to + + align:start position:0% +this thing the maximum is not going to + + + align:start position:0% +this thing the maximum is not going to +move much and this formula here so + + align:start position:0% +move much and this formula here so + + + align:start position:0% +move much and this formula here so +forget about the matrix version for a + + align:start position:0% +forget about the matrix version for a + + + align:start position:0% +forget about the matrix version for a +second is actually telling you exactly + + align:start position:0% +second is actually telling you exactly + + + align:start position:0% +second is actually telling you exactly +this it's telling me the curvature is + + align:start position:0% +this it's telling me the curvature is + + + align:start position:0% +this it's telling me the curvature is +basically the variance of this the first + + align:start position:0% +basically the variance of this the first + + + align:start position:0% +basically the variance of this the first +derivative and so the more the first + + align:start position:0% +derivative and so the more the first + + + align:start position:0% +derivative and so the more the first +derivative fluctuates the more your + + align:start position:0% +derivative fluctuates the more your + + + align:start position:0% +derivative fluctuates the more your +maximum is actually our max is going to + + align:start position:0% +maximum is actually our max is going to + + + align:start position:0% +maximum is actually our max is going to +move all over the place so this is + + align:start position:0% +move all over the place so this is + + + align:start position:0% +move all over the place so this is +really controlling how flat your map + + align:start position:0% +really controlling how flat your map + + + align:start position:0% +really controlling how flat your map +your likelihood your log likelihood is + + align:start position:0% +your likelihood your log likelihood is + + + align:start position:0% +your likelihood your log likelihood is +at its maximum the flatter it is the + + align:start position:0% +at its maximum the flatter it is the + + + align:start position:0% +at its maximum the flatter it is the +more sensitive to fluctuations er max is + + align:start position:0% +more sensitive to fluctuations er max is + + + align:start position:0% +more sensitive to fluctuations er max is +going to be the curvier it is the less + + align:start position:0% +going to be the curvier it is the less + + + align:start position:0% +going to be the curvier it is the less +sensitive it is and so what we're hoping + + align:start position:0% +sensitive it is and so what we're hoping + + + align:start position:0% +sensitive it is and so what we're hoping +a good model is going to be one that has + + align:start position:0% +a good model is going to be one that has + + + align:start position:0% +a good model is going to be one that has +a large + + align:start position:0% +a large + + + align:start position:0% +a large +small value for the Fisher information I + + align:start position:0% +small value for the Fisher information I + + + align:start position:0% +small value for the Fisher information I +want this to be small I want it to be + + align:start position:0% +want this to be small I want it to be + + + align:start position:0% +want this to be small I want it to be +large right because this is the + + align:start position:0% +large right because this is the + + + align:start position:0% +large right because this is the +curvature right this number is negative + + align:start position:0% +curvature right this number is negative + + + align:start position:0% +curvature right this number is negative +its concave so if I take a negative sign + + align:start position:0% +its concave so if I take a negative sign + + + align:start position:0% +its concave so if I take a negative sign +it's gonna be something that's positive + + align:start position:0% +it's gonna be something that's positive + + + align:start position:0% +it's gonna be something that's positive +and the larger this thing the more curvy + + align:start position:0% +and the larger this thing the more curvy + + + align:start position:0% +and the larger this thing the more curvy +it is oh yeah because it's the variance + + align:start position:0% +it is oh yeah because it's the variance + + + align:start position:0% +it is oh yeah because it's the variance +okay I'm sorry this is what okay yeah + + align:start position:0% +okay I'm sorry this is what okay yeah + + + align:start position:0% +okay I'm sorry this is what okay yeah +maybe I should not go into those details + + align:start position:0% +maybe I should not go into those details + + + align:start position:0% +maybe I should not go into those details +because I'm actually out of time but + + align:start position:0% +because I'm actually out of time but + + + align:start position:0% +because I'm actually out of time but +just spoiler alert + + align:start position:0% +just spoiler alert + + + align:start position:0% +just spoiler alert +the asymptotic variance of your the + + align:start position:0% +the asymptotic variance of your the + + + align:start position:0% +the asymptotic variance of your the +variance basically as n goes to infinity + + align:start position:0% +variance basically as n goes to infinity + + + align:start position:0% +variance basically as n goes to infinity +of the maximum likelihood estimator is + + align:start position:0% +of the maximum likelihood estimator is + + + align:start position:0% +of the maximum likelihood estimator is +going to be 1 over this guy so we want + + align:start position:0% +going to be 1 over this guy so we want + + + align:start position:0% +going to be 1 over this guy so we want +it to be large because that what the + + align:start position:0% +it to be large because that what the + + + align:start position:0% +it to be large because that what the +asymptotic variance is gonna be very + + align:start position:0% +asymptotic variance is gonna be very + + + align:start position:0% +asymptotic variance is gonna be very +small + + align:start position:0% +small + + + align:start position:0% +small +all right so we're out of time we'll see + + align:start position:0% +all right so we're out of time we'll see + + + align:start position:0% +all right so we're out of time we'll see +that next week and I have your homework + + align:start position:0% +that next week and I have your homework + + + align:start position:0% +that next week and I have your homework +with me and I will actually turn it in I + + align:start position:0% +with me and I will actually turn it in I + + + align:start position:0% +with me and I will actually turn it in I +will give it to you outside so we can + + align:start position:0% +will give it to you outside so we can + + + align:start position:0% +will give it to you outside so we can +leave let the other room + + align:start position:0% +leave let the other room + + + align:start position:0% +leave let the other room +come in ok I'll just leave it up \ No newline at end of file diff --git a/0WS0PBqTBrw.txt b/0WS0PBqTBrw.txt new file mode 100644 index 0000000000000000000000000000000000000000..f3eed7217c8d7c77461e4e3dd3f5eeb9cebdc2d1 --- /dev/null +++ b/0WS0PBqTBrw.txt @@ -0,0 +1,2411 @@ +align:start position:0% + +Uh next we're going to hear from Ania + + align:start position:0% +Uh next we're going to hear from Ania + + + align:start position:0% +Uh next we're going to hear from Ania +Kamargo who is uh associate director of + + align:start position:0% +Kamargo who is uh associate director of + + + align:start position:0% +Kamargo who is uh associate director of +thermal networks at the building + + align:start position:0% +thermal networks at the building + + + align:start position:0% +thermal networks at the building +decarbonization coalition to talk about + + align:start position:0% +decarbonization coalition to talk about + + + align:start position:0% +decarbonization coalition to talk about +that rapidly evolving policy landscape. + + align:start position:0% +that rapidly evolving policy landscape. + + + align:start position:0% +that rapidly evolving policy landscape. +And there's a little clicker. + + align:start position:0% +And there's a little clicker. + + + align:start position:0% +And there's a little clicker. +>> And there's clicker up there, I think. + + align:start position:0% +>> And there's clicker up there, I think. + + + align:start position:0% +>> And there's clicker up there, I think. +>> All right. + + align:start position:0% + + + + align:start position:0% + +>> Okay. Hi. Good afternoon, everyone. Um, + + align:start position:0% +>> Okay. Hi. Good afternoon, everyone. Um, + + + align:start position:0% +>> Okay. Hi. Good afternoon, everyone. Um, +so I you see I have geo there in + + align:start position:0% +so I you see I have geo there in + + + align:start position:0% +so I you see I have geo there in +parenthesis and that is because most of + + align:start position:0% +parenthesis and that is because most of + + + align:start position:0% +parenthesis and that is because most of +the legislation that has the legislation + + align:start position:0% +the legislation that has the legislation + + + align:start position:0% +the legislation that has the legislation +that's passed to date uses the term uh + + align:start position:0% +that's passed to date uses the term uh + + + align:start position:0% +that's passed to date uses the term uh +thermal energy network. So you will be + + align:start position:0% +thermal energy network. So you will be + + + align:start position:0% +thermal energy network. So you will be +hearing me say that, but in general I'm + + align:start position:0% +hearing me say that, but in general I'm + + + align:start position:0% +hearing me say that, but in general I'm +talking about the broad category of both + + align:start position:0% +talking about the broad category of both + + + align:start position:0% +talking about the broad category of both +geothermal energy networks and thermal + + align:start position:0% +geothermal energy networks and thermal + + + align:start position:0% +geothermal energy networks and thermal +energy networks. And I'm just going to + + align:start position:0% +energy networks. And I'm just going to + + + align:start position:0% +energy networks. And I'm just going to +give you a picture of what's happening + + align:start position:0% +give you a picture of what's happening + + + align:start position:0% +give you a picture of what's happening +nationally. + + align:start position:0% +nationally. + + + align:start position:0% +nationally. +So here is how a bill becomes law. This + + align:start position:0% +So here is how a bill becomes law. This + + + align:start position:0% +So here is how a bill becomes law. This +is real. Um it is just never a straight + + align:start position:0% +is real. Um it is just never a straight + + + align:start position:0% +is real. Um it is just never a straight +line. It's very messy. And the reason + + align:start position:0% +line. It's very messy. And the reason + + + align:start position:0% +line. It's very messy. And the reason +why it's messy is kind of what delegate + + align:start position:0% +why it's messy is kind of what delegate + + + align:start position:0% +why it's messy is kind of what delegate +Shakudin was saying. It's about bringing + + align:start position:0% +Shakudin was saying. It's about bringing + + + align:start position:0% +Shakudin was saying. It's about bringing +stakeholders together with different + + align:start position:0% +stakeholders together with different + + + align:start position:0% +stakeholders together with different +interests and making sure that all of + + align:start position:0% +interests and making sure that all of + + + align:start position:0% +interests and making sure that all of +their interests are being met. So rarely + + align:start position:0% +their interests are being met. So rarely + + + align:start position:0% +their interests are being met. So rarely +does the start end up like the finish. + + align:start position:0% +does the start end up like the finish. + + + align:start position:0% +does the start end up like the finish. +But the really good news with uh thermal + + align:start position:0% +But the really good news with uh thermal + + + align:start position:0% +But the really good news with uh thermal +networks is that states are learning + + align:start position:0% +networks is that states are learning + + + align:start position:0% +networks is that states are learning +from each other. So this is coming + + align:start position:0% +from each other. So this is coming + + + align:start position:0% +from each other. So this is coming +becoming a little less muddy and uh + + align:start position:0% +becoming a little less muddy and uh + + + align:start position:0% +becoming a little less muddy and uh +legislation is moving really fast. + + align:start position:0% +legislation is moving really fast. + + + align:start position:0% +legislation is moving really fast. +Um so again I'm going to start with this + + align:start position:0% +Um so again I'm going to start with this + + + align:start position:0% +Um so again I'm going to start with this +one on like what's the general journey + + align:start position:0% +one on like what's the general journey + + + align:start position:0% +one on like what's the general journey +that we're seeing in legislation and + + align:start position:0% +that we're seeing in legislation and + + + align:start position:0% +that we're seeing in legislation and +again I have the word utility up there + + align:start position:0% +again I have the word utility up there + + + align:start position:0% +again I have the word utility up there +because the only uh anyone can build a + + align:start position:0% +because the only uh anyone can build a + + + align:start position:0% +because the only uh anyone can build a +thermal network right now uh + + align:start position:0% +thermal network right now uh + + + align:start position:0% +thermal network right now uh +municipality lots of colleges and + + align:start position:0% +municipality lots of colleges and + + + align:start position:0% +municipality lots of colleges and +universities a hospital anyone except + + align:start position:0% +universities a hospital anyone except + + + align:start position:0% +universities a hospital anyone except +for a regulated utility. And so we have + + align:start position:0% +for a regulated utility. And so we have + + + align:start position:0% +for a regulated utility. And so we have +to pass legislation to allow gas and + + align:start position:0% +to pass legislation to allow gas and + + + align:start position:0% +to pass legislation to allow gas and +electric or water companies to sell + + align:start position:0% +electric or water companies to sell + + + align:start position:0% +electric or water companies to sell +thermal or to build thermal networks. So + + align:start position:0% +thermal or to build thermal networks. So + + + align:start position:0% +thermal or to build thermal networks. So +the way it starts is exactly like uh + + align:start position:0% +the way it starts is exactly like uh + + + align:start position:0% +the way it starts is exactly like uh +delegate Shudian said it's in all the + + align:start position:0% +delegate Shudian said it's in all the + + + align:start position:0% +delegate Shudian said it's in all the +states that were working or that are + + align:start position:0% +states that were working or that are + + + align:start position:0% +states that were working or that are +passing this legislation. It's really a + + align:start position:0% +passing this legislation. It's really a + + + align:start position:0% +passing this legislation. It's really a +group of advocates. In her case, she was + + align:start position:0% +group of advocates. In her case, she was + + + align:start position:0% +group of advocates. In her case, she was +the legislator who started, but then she + + align:start position:0% +the legislator who started, but then she + + + align:start position:0% +the legislator who started, but then she +worked with all the people here. As you + + align:start position:0% +worked with all the people here. As you + + + align:start position:0% +worked with all the people here. As you +heard this morning from Kelsey, it + + align:start position:0% +heard this morning from Kelsey, it + + + align:start position:0% +heard this morning from Kelsey, it +started with mothers out front. Um and + + align:start position:0% +started with mothers out front. Um and + + + align:start position:0% +started with mothers out front. Um and +then the underpinning of this for the + + align:start position:0% +then the underpinning of this for the + + + align:start position:0% +then the underpinning of this for the +legislation that has passed so far is + + align:start position:0% +legislation that has passed so far is + + + align:start position:0% +legislation that has passed so far is +that all of the states so eight bills + + align:start position:0% +that all of the states so eight bills + + + align:start position:0% +that all of the states so eight bills +have passed all of the states have + + align:start position:0% +have passed all of the states have + + + align:start position:0% +have passed all of the states have +significant climate commitments of at + + align:start position:0% +significant climate commitments of at + + + align:start position:0% +significant climate commitments of at +least reducing total emissions by 75% or + + align:start position:0% +least reducing total emissions by 75% or + + + align:start position:0% +least reducing total emissions by 75% or +more um and greening the grid um so RPS + + align:start position:0% +more um and greening the grid um so RPS + + + align:start position:0% +more um and greening the grid um so RPS +commitments and seven out of the eight + + align:start position:0% +commitments and seven out of the eight + + + align:start position:0% +commitments and seven out of the eight +that have passed have future of gas + + align:start position:0% +that have passed have future of gas + + + align:start position:0% +that have passed have future of gas +proceedings meaning the regulators have + + align:start position:0% +proceedings meaning the regulators have + + + align:start position:0% +proceedings meaning the regulators have +said hey gas companies how are you going + + align:start position:0% +said hey gas companies how are you going + + + align:start position:0% +said hey gas companies how are you going +to meet these commitments so this is + + align:start position:0% +to meet these commitments so this is + + + align:start position:0% +to meet these commitments so this is +what's happened to date, not necessarily + + align:start position:0% +what's happened to date, not necessarily + + + align:start position:0% +what's happened to date, not necessarily +will happen in the future, but this is + + align:start position:0% +will happen in the future, but this is + + + align:start position:0% +will happen in the future, but this is +the kind of bills are very attached to + + align:start position:0% +the kind of bills are very attached to + + + align:start position:0% +the kind of bills are very attached to +our missions. Um, once legislation + + align:start position:0% +our missions. Um, once legislation + + + align:start position:0% +our missions. Um, once legislation +passes, there's a whole process that + + align:start position:0% +passes, there's a whole process that + + + align:start position:0% +passes, there's a whole process that +kicks off with the regulators, which you + + align:start position:0% +kicks off with the regulators, which you + + + align:start position:0% +kicks off with the regulators, which you +will hear after me from Sher Van + + align:start position:0% +will hear after me from Sher Van + + + align:start position:0% +will hear after me from Sher Van +Nostrin, but it's a it's a kind of a + + align:start position:0% +Nostrin, but it's a it's a kind of a + + + align:start position:0% +Nostrin, but it's a it's a kind of a +negotiation between the utilities and + + align:start position:0% +negotiation between the utilities and + + + align:start position:0% +negotiation between the utilities and +the regulators looking at the + + align:start position:0% +the regulators looking at the + + + align:start position:0% +the regulators looking at the +legislation that passed, saying, "Okay, + + align:start position:0% +legislation that passed, saying, "Okay, + + + align:start position:0% +legislation that passed, saying, "Okay, +what needs to happen for us to be able + + align:start position:0% +what needs to happen for us to be able + + + align:start position:0% +what needs to happen for us to be able +to move forward?" At the same time, + + align:start position:0% +to move forward?" At the same time, + + + align:start position:0% +to move forward?" At the same time, +you're going to have to be working on + + align:start position:0% +you're going to have to be working on + + + align:start position:0% +you're going to have to be working on +the, you know, the workforce, supply + + align:start position:0% +the, you know, the workforce, supply + + + align:start position:0% +the, you know, the workforce, supply +chain, making sure there's community + + align:start position:0% +chain, making sure there's community + + + align:start position:0% +chain, making sure there's community +outreach, etc. And then you can get to + + align:start position:0% +outreach, etc. And then you can get to + + + align:start position:0% +outreach, etc. And then you can get to +construction. Um, so so far only one + + align:start position:0% +construction. Um, so so far only one + + + align:start position:0% +construction. Um, so so far only one +project, which is here in Massachusetts, + + align:start position:0% +project, which is here in Massachusetts, + + + align:start position:0% +project, which is here in Massachusetts, +has made it through construction. And + + align:start position:0% +has made it through construction. And + + + align:start position:0% +has made it through construction. And +all of the bills that have passed uh + + align:start position:0% +all of the bills that have passed uh + + + align:start position:0% +all of the bills that have passed uh +require data collection and pilot + + align:start position:0% +require data collection and pilot + + + align:start position:0% +require data collection and pilot +evaluation. So this is this is again, + + align:start position:0% +evaluation. So this is this is again, + + + align:start position:0% +evaluation. So this is this is again, +every state is different, but this is + + align:start position:0% +every state is different, but this is + + + align:start position:0% +every state is different, but this is +the broad thing that we're seeing across + + align:start position:0% +the broad thing that we're seeing across + + + align:start position:0% +the broad thing that we're seeing across +the state that gets uh legislation + + align:start position:0% +the state that gets uh legislation + + + align:start position:0% +the state that gets uh legislation +passed. And here are the eight bills um + + align:start position:0% +passed. And here are the eight bills um + + + align:start position:0% +passed. And here are the eight bills um +the eight states that have passed. + + align:start position:0% +the eight states that have passed. + + + align:start position:0% +the eight states that have passed. +They're listed there on the right. Uh + + align:start position:0% +They're listed there on the right. Uh + + + align:start position:0% +They're listed there on the right. Uh +you will notice uh 2021 Massachusetts + + align:start position:0% +you will notice uh 2021 Massachusetts + + + align:start position:0% +you will notice uh 2021 Massachusetts +passed the first bill that allowed uh + + align:start position:0% +passed the first bill that allowed uh + + + align:start position:0% +passed the first bill that allowed uh +network geothermal. And just this year + + align:start position:0% +network geothermal. And just this year + + + align:start position:0% +network geothermal. And just this year +2024 four bills passed as well as + + align:start position:0% +2024 four bills passed as well as + + + align:start position:0% +2024 four bills passed as well as +several states did another round of + + align:start position:0% +several states did another round of + + + align:start position:0% +several states did another round of +passing legislation. Uh and then you see + + align:start position:0% +passing legislation. Uh and then you see + + + align:start position:0% +passing legislation. Uh and then you see +there dark blue considering legislation. + + align:start position:0% +there dark blue considering legislation. + + + align:start position:0% +there dark blue considering legislation. +Actually uh just this month already five + + align:start position:0% +Actually uh just this month already five + + + align:start position:0% +Actually uh just this month already five +new states have filed legislation. So, + + align:start position:0% +new states have filed legislation. So, + + + align:start position:0% +new states have filed legislation. So, +we are expecting this to continue to + + align:start position:0% +we are expecting this to continue to + + + align:start position:0% +we are expecting this to continue to +grow. + + align:start position:0% +grow. + + + align:start position:0% +grow. +And this, you don't need to read this. + + align:start position:0% +And this, you don't need to read this. + + + align:start position:0% +And this, you don't need to read this. +Uh, it's just to give you a sense of + + align:start position:0% +Uh, it's just to give you a sense of + + + align:start position:0% +Uh, it's just to give you a sense of +what's in these bills. You see the + + align:start position:0% +what's in these bills. You see the + + + align:start position:0% +what's in these bills. You see the +states across the top, and you can sort + + align:start position:0% +states across the top, and you can sort + + + align:start position:0% +states across the top, and you can sort +of see what the provisions are. And the + + align:start position:0% +of see what the provisions are. And the + + + align:start position:0% +of see what the provisions are. And the +key thing about here is the states are + + align:start position:0% +key thing about here is the states are + + + align:start position:0% +key thing about here is the states are +learning from each other. And this is on + + align:start position:0% +learning from each other. And this is on + + + align:start position:0% +learning from each other. And this is on +our website, so you can check it out. + + align:start position:0% +our website, so you can check it out. + + + align:start position:0% +our website, so you can check it out. +Um, all right. So, now I'm going to + + align:start position:0% +Um, all right. So, now I'm going to + + + align:start position:0% +Um, all right. So, now I'm going to +combine it. Like, what does this all + + align:start position:0% +combine it. Like, what does this all + + + align:start position:0% +combine it. Like, what does this all +mean? And it's really about how does the + + align:start position:0% +mean? And it's really about how does the + + + align:start position:0% +mean? And it's really about how does the +the technology and the stuff on the + + align:start position:0% +the technology and the stuff on the + + + align:start position:0% +the technology and the stuff on the +ground relate to the legislation and the + + align:start position:0% +ground relate to the legislation and the + + + align:start position:0% +ground relate to the legislation and the +regulation. So here's a great uh diagram + + align:start position:0% +regulation. So here's a great uh diagram + + + align:start position:0% +regulation. So here's a great uh diagram +that heat put together. It's a gas + + align:start position:0% +that heat put together. It's a gas + + + align:start position:0% +that heat put together. It's a gas +system. And you can see that very cute + + align:start position:0% +system. And you can see that very cute + + + align:start position:0% +system. And you can see that very cute +little section of green. That's the + + align:start position:0% +little section of green. That's the + + + align:start position:0% +little section of green. That's the +thermal network. And so this is the + + align:start position:0% +thermal network. And so this is the + + + align:start position:0% +thermal network. And so this is the +demonstration. All eight bills uh either + + align:start position:0% +demonstration. All eight bills uh either + + + align:start position:0% +demonstration. All eight bills uh either +allow or mandate pilot. So everyone is + + align:start position:0% +allow or mandate pilot. So everyone is + + + align:start position:0% +allow or mandate pilot. So everyone is +starting with demonstration. So what's + + align:start position:0% +starting with demonstration. So what's + + + align:start position:0% +starting with demonstration. So what's +the kind of uh work that comes with + + align:start position:0% +the kind of uh work that comes with + + + align:start position:0% +the kind of uh work that comes with +that? The bills include + + align:start position:0% +that? The bills include + + + align:start position:0% +that? The bills include +um a whole series of things that are + + align:start position:0% +um a whole series of things that are + + + align:start position:0% +um a whole series of things that are +about these pilots, right? So the + + align:start position:0% +about these pilots, right? So the + + + align:start position:0% +about these pilots, right? So the +definitions uh ownership is really + + align:start position:0% +definitions uh ownership is really + + + align:start position:0% +definitions uh ownership is really +interesting in starting with New York. + + align:start position:0% +interesting in starting with New York. + + + align:start position:0% +interesting in starting with New York. +The the legislation actually says gas + + align:start position:0% +The the legislation actually says gas + + + align:start position:0% +The the legislation actually says gas +and electric utilities can own and + + align:start position:0% +and electric utilities can own and + + + align:start position:0% +and electric utilities can own and +operate thermal energy networks. And + + align:start position:0% +operate thermal energy networks. And + + + align:start position:0% +operate thermal energy networks. And +then several of the states after that + + align:start position:0% +then several of the states after that + + + align:start position:0% +then several of the states after that +implemented the same thing. Uh + + align:start position:0% +implemented the same thing. Uh + + + align:start position:0% +implemented the same thing. Uh +Massachusetts, we just passed + + align:start position:0% +Massachusetts, we just passed + + + align:start position:0% +Massachusetts, we just passed +legislation 2024 that allows the selling + + align:start position:0% +legislation 2024 that allows the selling + + + align:start position:0% +legislation 2024 that allows the selling +of thermal energy by the gas utilities. + + align:start position:0% +of thermal energy by the gas utilities. + + + align:start position:0% +of thermal energy by the gas utilities. +Um some include environmental + + align:start position:0% +Um some include environmental + + + align:start position:0% +Um some include environmental +protections, labor standards. You just + + align:start position:0% +protections, labor standards. You just + + + align:start position:0% +protections, labor standards. You just +heard from Ryan in New York, that group + + align:start position:0% +heard from Ryan in New York, that group + + + align:start position:0% +heard from Ryan in New York, that group +of advocates, one of the core uh members + + align:start position:0% +of advocates, one of the core uh members + + + align:start position:0% +of advocates, one of the core uh members +of that group of advocates were labor + + align:start position:0% +of that group of advocates were labor + + + align:start position:0% +of that group of advocates were labor +leaders. And so they're very strong + + align:start position:0% +leaders. And so they're very strong + + + align:start position:0% +leaders. And so they're very strong +labor standards in the New York bill + + align:start position:0% +labor standards in the New York bill + + + align:start position:0% +labor standards in the New York bill +that are about the geothermal workforce + + align:start position:0% +that are about the geothermal workforce + + + align:start position:0% +that are about the geothermal workforce +in general, but also about the existing + + align:start position:0% +in general, but also about the existing + + + align:start position:0% +in general, but also about the existing +gas for uh workforce and how that how + + align:start position:0% +gas for uh workforce and how that how + + + align:start position:0% +gas for uh workforce and how that how +they're going to be transitioned as part + + align:start position:0% +they're going to be transitioned as part + + + align:start position:0% +they're going to be transitioned as part +of this um consumer protection. I should + + align:start position:0% +of this um consumer protection. I should + + + align:start position:0% +of this um consumer protection. I should +say also environmental justice in there + + align:start position:0% +say also environmental justice in there + + + align:start position:0% +say also environmental justice in there +that uh many of the bills again starting + + align:start position:0% +that uh many of the bills again starting + + + align:start position:0% +that uh many of the bills again starting +with New York require at least one pilot + + align:start position:0% +with New York require at least one pilot + + + align:start position:0% +with New York require at least one pilot +to be in an environmental justice + + align:start position:0% +to be in an environmental justice + + + align:start position:0% +to be in an environmental justice +community and uh several of them say + + align:start position:0% +community and uh several of them say + + + align:start position:0% +community and uh several of them say +that they the customer should not have + + align:start position:0% +that they the customer should not have + + + align:start position:0% +that they the customer should not have +to pay more than what they're currently + + align:start position:0% +to pay more than what they're currently + + + align:start position:0% +to pay more than what they're currently +paying on their bills. All of them + + align:start position:0% +paying on their bills. All of them + + + align:start position:0% +paying on their bills. All of them +include cost recovery. So the pilots can + + align:start position:0% +include cost recovery. So the pilots can + + + align:start position:0% +include cost recovery. So the pilots can +go through the rates, but the issue is + + align:start position:0% +go through the rates, but the issue is + + + align:start position:0% +go through the rates, but the issue is +what's included. And so the states vary + + align:start position:0% +what's included. And so the states vary + + + align:start position:0% +what's included. And so the states vary +in that. Here in Massachusetts, + + align:start position:0% +in that. Here in Massachusetts, + + + align:start position:0% +in that. Here in Massachusetts, +everything could go through the rates. + + align:start position:0% +everything could go through the rates. + + + align:start position:0% +everything could go through the rates. +In California, for example, all of the + + align:start position:0% +In California, for example, all of the + + + align:start position:0% +In California, for example, all of the +behind the meter costs, which are pretty + + align:start position:0% +behind the meter costs, which are pretty + + + align:start position:0% +behind the meter costs, which are pretty +significant, all the retrofits uh + + align:start position:0% +significant, all the retrofits uh + + + align:start position:0% +significant, all the retrofits uh +cannot. And so they're struggling with + + align:start position:0% +cannot. And so they're struggling with + + + align:start position:0% +cannot. And so they're struggling with +how we're going to pay for that. Um and + + align:start position:0% +how we're going to pay for that. Um and + + + align:start position:0% +how we're going to pay for that. Um and +then pilot data collection and + + align:start position:0% +then pilot data collection and + + + align:start position:0% +then pilot data collection and +reporting. I guess I already said + + align:start position:0% +reporting. I guess I already said + + + align:start position:0% +reporting. I guess I already said +they're all doing this anyway. So this + + align:start position:0% +they're all doing this anyway. So this + + + align:start position:0% +they're all doing this anyway. So this +is sort of how this works. Next step + + align:start position:0% +is sort of how this works. Next step + + + align:start position:0% +is sort of how this works. Next step +um is development. And this is now where + + align:start position:0% +um is development. And this is now where + + + align:start position:0% +um is development. And this is now where +we're starting here in Massachusetts. + + align:start position:0% +we're starting here in Massachusetts. + + + align:start position:0% +we're starting here in Massachusetts. +It's like you grab what you learned from + + align:start position:0% +It's like you grab what you learned from + + + align:start position:0% +It's like you grab what you learned from +that first pilot and now we're + + align:start position:0% +that first pilot and now we're + + + align:start position:0% +that first pilot and now we're +expanding. And how's that going to work? + + align:start position:0% +expanding. And how's that going to work? + + + align:start position:0% +expanding. And how's that going to work? +And so through that, some of these bills + + align:start position:0% +And so through that, some of these bills + + + align:start position:0% +And so through that, some of these bills +are starting to pass and there's some + + align:start position:0% +are starting to pass and there's some + + + align:start position:0% +are starting to pass and there's some +conversations. Um interim rate design, + + align:start position:0% +conversations. Um interim rate design, + + + align:start position:0% +conversations. Um interim rate design, +how are we going to design the rates to + + align:start position:0% +how are we going to design the rates to + + + align:start position:0% +how are we going to design the rates to +deal with this? Uh amending the + + align:start position:0% +deal with this? Uh amending the + + + align:start position:0% +deal with this? Uh amending the +obligation to serve. This is a huge one. + + align:start position:0% +obligation to serve. This is a huge one. + + + align:start position:0% +obligation to serve. This is a huge one. +Many states file legislation to try to + + align:start position:0% +Many states file legislation to try to + + + align:start position:0% +Many states file legislation to try to +change this. and a full uh I I I'm going + + align:start position:0% +change this. and a full uh I I I'm going + + + align:start position:0% +change this. and a full uh I I I'm going +to explain what that is, which is if any + + align:start position:0% +to explain what that is, which is if any + + + align:start position:0% +to explain what that is, which is if any +one of those little house green houses + + align:start position:0% +one of those little house green houses + + + align:start position:0% +one of those little house green houses +says, "No, I want to stay on gas." It + + align:start position:0% +says, "No, I want to stay on gas." It + + + align:start position:0% +says, "No, I want to stay on gas." It +means that the gas system has to stay, + + align:start position:0% +means that the gas system has to stay, + + + align:start position:0% +means that the gas system has to stay, +you can't pull it back. And so amending + + align:start position:0% +you can't pull it back. And so amending + + + align:start position:0% +you can't pull it back. And so amending +it so that the gas um utilities can + + align:start position:0% +it so that the gas um utilities can + + + align:start position:0% +it so that the gas um utilities can +expand their service to not just be + + align:start position:0% +expand their service to not just be + + + align:start position:0% +expand their service to not just be +about gas, but also to be or to sell + + align:start position:0% +about gas, but also to be or to sell + + + align:start position:0% +about gas, but also to be or to sell +thermal energy allows them to then say, + + align:start position:0% +thermal energy allows them to then say, + + + align:start position:0% +thermal energy allows them to then say, +"Okay, we're going to provide you + + align:start position:0% +"Okay, we're going to provide you + + + align:start position:0% +"Okay, we're going to provide you +heating and cooling, but it's not going + + align:start position:0% +heating and cooling, but it's not going + + + align:start position:0% +heating and cooling, but it's not going +to be with gas." And so so far two + + align:start position:0% +to be with gas." And so so far two + + + align:start position:0% +to be with gas." And so so far two +states have touched that. Uh Washington + + align:start position:0% +states have touched that. Uh Washington + + + align:start position:0% +states have touched that. Uh Washington +state for thermal energy networks are + + align:start position:0% +state for thermal energy networks are + + + align:start position:0% +state for thermal energy networks are +allowed to meet the obligation to serve + + align:start position:0% +allowed to meet the obligation to serve + + + align:start position:0% +allowed to meet the obligation to serve +with thermal. And California has a + + align:start position:0% +with thermal. And California has a + + + align:start position:0% +with thermal. And California has a +really interesting one where they said + + align:start position:0% +really interesting one where they said + + + align:start position:0% +really interesting one where they said +60% if 60% of a street or the segment + + align:start position:0% +60% if 60% of a street or the segment + + + align:start position:0% +60% if 60% of a street or the segment +that they're taking the gas pipe out of + + align:start position:0% +that they're taking the gas pipe out of + + + align:start position:0% +that they're taking the gas pipe out of +says that they want a thermal network + + align:start position:0% +says that they want a thermal network + + + align:start position:0% +says that they want a thermal network +then they're allowed to meet the + + align:start position:0% +then they're allowed to meet the + + + align:start position:0% +then they're allowed to meet the +obligation to serve that way. Um gas oh + + align:start position:0% +obligation to serve that way. Um gas oh + + + align:start position:0% +obligation to serve that way. Um gas oh +so then uh joint electric planning. This + + align:start position:0% +so then uh joint electric planning. This + + + align:start position:0% +so then uh joint electric planning. This +is uh our commissioner uh chair van will + + align:start position:0% +is uh our commissioner uh chair van will + + + align:start position:0% +is uh our commissioner uh chair van will +talk about this but basically the one of + + align:start position:0% +talk about this but basically the one of + + + align:start position:0% +talk about this but basically the one of +the biggest benefits of putting in these + + align:start position:0% +the biggest benefits of putting in these + + + align:start position:0% +the biggest benefits of putting in these +thermal networks is the impact on the + + align:start position:0% +thermal networks is the impact on the + + + align:start position:0% +thermal networks is the impact on the +electric grid and so being able to have + + align:start position:0% +electric grid and so being able to have + + + align:start position:0% +electric grid and so being able to have +that joint planning and prioritizing of + + align:start position:0% +that joint planning and prioritizing of + + + align:start position:0% +that joint planning and prioritizing of +where these things should be built is + + align:start position:0% +where these things should be built is + + + align:start position:0% +where these things should be built is +really important and so we're starting + + align:start position:0% +really important and so we're starting + + + align:start position:0% +really important and so we're starting +to see that already and not only in + + align:start position:0% +to see that already and not only in + + + align:start position:0% +to see that already and not only in +Massachusetts but elsewhere and thinking + + align:start position:0% +Massachusetts but elsewhere and thinking + + + align:start position:0% +Massachusetts but elsewhere and thinking +of okay which like if you're going to + + align:start position:0% +of okay which like if you're going to + + + align:start position:0% +of okay which like if you're going to +replace a pipe that's an obvious place + + align:start position:0% +replace a pipe that's an obvious place + + + align:start position:0% +replace a pipe that's an obvious place +uh if you if you're going to build a + + align:start position:0% +uh if you if you're going to build a + + + align:start position:0% +uh if you if you're going to build a +substation an electric substation + + align:start position:0% +substation an electric substation + + + align:start position:0% +substation an electric substation +because you're running out of capacity. + + align:start position:0% +because you're running out of capacity. + + + align:start position:0% +because you're running out of capacity. +Maybe that's a great place. So, that's + + align:start position:0% +Maybe that's a great place. So, that's + + + align:start position:0% +Maybe that's a great place. So, that's +starting. Um, and then of course the + + align:start position:0% +starting. Um, and then of course the + + + align:start position:0% +starting. Um, and then of course the +full system transition, which is what we + + align:start position:0% +full system transition, which is what we + + + align:start position:0% +full system transition, which is what we +all want, is going to require a lot + + align:start position:0% +all want, is going to require a lot + + + align:start position:0% +all want, is going to require a lot +more. And this uh really hasn't started. + + align:start position:0% +more. And this uh really hasn't started. + + + align:start position:0% +more. And this uh really hasn't started. +I mean, we've filed some of this this + + align:start position:0% +I mean, we've filed some of this this + + + align:start position:0% +I mean, we've filed some of this this +cycle for two years from now here in + + align:start position:0% +cycle for two years from now here in + + + align:start position:0% +cycle for two years from now here in +Massachusetts. But creating a thermal + + align:start position:0% +Massachusetts. But creating a thermal + + + align:start position:0% +Massachusetts. But creating a thermal +market, allowing folks to buy and sell + + align:start position:0% +market, allowing folks to buy and sell + + + align:start position:0% +market, allowing folks to buy and sell +energy, uh, integrating utilities, gas, + + align:start position:0% +energy, uh, integrating utilities, gas, + + + align:start position:0% +energy, uh, integrating utilities, gas, +electric, and potentially even water. + + align:start position:0% +electric, and potentially even water. + + + align:start position:0% +electric, and potentially even water. +like water has the water utilities also + + align:start position:0% +like water has the water utilities also + + + align:start position:0% +like water has the water utilities also +have a lot of thermal energy. Uh waste + + align:start position:0% +have a lot of thermal energy. Uh waste + + + align:start position:0% +have a lot of thermal energy. Uh waste +heat recovery, how is what's the what + + align:start position:0% +heat recovery, how is what's the what + + + align:start position:0% +heat recovery, how is what's the what +are the rules going to be around that? + + align:start position:0% +are the rules going to be around that? + + + align:start position:0% +are the rules going to be around that? +Uh tactical transition plans for whole + + align:start position:0% +Uh tactical transition plans for whole + + + align:start position:0% +Uh tactical transition plans for whole +cities and regions. And so this idea + + align:start position:0% +cities and regions. And so this idea + + + align:start position:0% +cities and regions. And so this idea +that you can map out, you know, how old + + align:start position:0% +that you can map out, you know, how old + + + align:start position:0% +that you can map out, you know, how old +your pipe is, you know, what's going to + + align:start position:0% +your pipe is, you know, what's going to + + + align:start position:0% +your pipe is, you know, what's going to +have to be taken down, what's going to + + align:start position:0% +have to be taken down, what's going to + + + align:start position:0% +have to be taken down, what's going to +make the most sense for everything and + + align:start position:0% +make the most sense for everything and + + + align:start position:0% +make the most sense for everything and +how can we transition the whole system + + align:start position:0% +how can we transition the whole system + + + align:start position:0% +how can we transition the whole system +thinking 10 years ahead and not just + + align:start position:0% +thinking 10 years ahead and not just + + + align:start position:0% +thinking 10 years ahead and not just +five or two. Um and then the final rate + + align:start position:0% +five or two. Um and then the final rate + + + align:start position:0% +five or two. Um and then the final rate +design you know still in consideration + + align:start position:0% +design you know still in consideration + + + align:start position:0% +design you know still in consideration +and I I'm involved in a few dockets + + align:start position:0% +and I I'm involved in a few dockets + + + align:start position:0% +and I I'm involved in a few dockets +across the country in some places the + + align:start position:0% +across the country in some places the + + + align:start position:0% +across the country in some places the +combination of the electric I mean I'm + + align:start position:0% +combination of the electric I mean I'm + + + align:start position:0% +combination of the electric I mean I'm +sorry of the thermal and geo rate makes + + align:start position:0% +sorry of the thermal and geo rate makes + + + align:start position:0% +sorry of the thermal and geo rate makes +a lot of sense right it's being covered + + align:start position:0% +a lot of sense right it's being covered + + + align:start position:0% +a lot of sense right it's being covered +by all the customers some folks are + + align:start position:0% +by all the customers some folks are + + + align:start position:0% +by all the customers some folks are +fighting that and saying no it should be + + align:start position:0% +fighting that and saying no it should be + + + align:start position:0% +fighting that and saying no it should be +by itself and then in New York there's + + align:start position:0% +by itself and then in New York there's + + + align:start position:0% +by itself and then in New York there's +one utility who's saying it should be + + align:start position:0% +one utility who's saying it should be + + + align:start position:0% +one utility who's saying it should be +covered by both gas and electric because + + align:start position:0% +covered by both gas and electric because + + + align:start position:0% +covered by both gas and electric because +the electric customers are the ones that + + align:start position:0% +the electric customers are the ones that + + + align:start position:0% +the electric customers are the ones that +are most benefiting. Um I I talked about + + align:start position:0% +are most benefiting. Um I I talked about + + + align:start position:0% +are most benefiting. Um I I talked about +allowable cost recovery and then big is + + align:start position:0% +allowable cost recovery and then big is + + + align:start position:0% +allowable cost recovery and then big is +the the voided cost uh uh integration + + align:start position:0% +the the voided cost uh uh integration + + + align:start position:0% +the the voided cost uh uh integration +into the thermal networks because what + + align:start position:0% +into the thermal networks because what + + + align:start position:0% +into the thermal networks because what +is happening is that the that benefit on + + align:start position:0% +is happening is that the that benefit on + + + align:start position:0% +is happening is that the that benefit on +the electric grid means that we're not + + align:start position:0% +the electric grid means that we're not + + + align:start position:0% +the electric grid means that we're not +going to have to build out the electric + + align:start position:0% +going to have to build out the electric + + + align:start position:0% +going to have to build out the electric +grid but the costs are on the network + + align:start position:0% +grid but the costs are on the network + + + align:start position:0% +grid but the costs are on the network +geothermal installer like so so the + + align:start position:0% +geothermal installer like so so the + + + align:start position:0% +geothermal installer like so so the +benefits and the costs are not aligned + + align:start position:0% +benefits and the costs are not aligned + + + align:start position:0% +benefits and the costs are not aligned +and so we have to figure out how to do + + align:start position:0% +and so we have to figure out how to do + + + align:start position:0% +and so we have to figure out how to do +that. Um, so that's sort of how the + + align:start position:0% +that. Um, so that's sort of how the + + + align:start position:0% +that. Um, so that's sort of how the +policy and this thing is we're hoping + + align:start position:0% +policy and this thing is we're hoping + + + align:start position:0% +policy and this thing is we're hoping +it's going to roll out. Um, and I just + + align:start position:0% +it's going to roll out. Um, and I just + + + align:start position:0% +it's going to roll out. Um, and I just +want to say remember only eight states + + align:start position:0% +want to say remember only eight states + + + align:start position:0% +want to say remember only eight states +have passed legislation, but this map + + align:start position:0% +have passed legislation, but this map + + + align:start position:0% +have passed legislation, but this map +looks a lot better than that, which is + + align:start position:0% +looks a lot better than that, which is + + + align:start position:0% +looks a lot better than that, which is +utilities across the country are really + + align:start position:0% +utilities across the country are really + + + align:start position:0% +utilities across the country are really +interested in doing this. Um, regardless + + align:start position:0% +interested in doing this. Um, regardless + + + align:start position:0% +interested in doing this. Um, regardless +of whether legislation has passed or + + align:start position:0% +of whether legislation has passed or + + + align:start position:0% +of whether legislation has passed or +not, this is the a map of the utility + + align:start position:0% +not, this is the a map of the utility + + + align:start position:0% +not, this is the a map of the utility +net geo collaborative and both blues are + + align:start position:0% +net geo collaborative and both blues are + + + align:start position:0% +net geo collaborative and both blues are +actually members of that collaborative. + + align:start position:0% +actually members of that collaborative. + + + align:start position:0% +actually members of that collaborative. +Um and uh they are basically exploring + + align:start position:0% +Um and uh they are basically exploring + + + align:start position:0% +Um and uh they are basically exploring +the exploring what this looks like for + + align:start position:0% +the exploring what this looks like for + + + align:start position:0% +the exploring what this looks like for +them. And the the maps the light blue is + + align:start position:0% +them. And the the maps the light blue is + + + align:start position:0% +them. And the the maps the light blue is +states where at least uh one utility has + + align:start position:0% +states where at least uh one utility has + + + align:start position:0% +states where at least uh one utility has +filed a pilot. So far there's been 22 + + align:start position:0% +filed a pilot. So far there's been 22 + + + align:start position:0% +filed a pilot. So far there's been 22 +pilots filed with the regulatory + + align:start position:0% +pilots filed with the regulatory + + + align:start position:0% +pilots filed with the regulatory +commission. And then I just also want to + + align:start position:0% +commission. And then I just also want to + + + align:start position:0% +commission. And then I just also want to +end with this map which I hope you'll + + align:start position:0% +end with this map which I hope you'll + + + align:start position:0% +end with this map which I hope you'll +all check out because you can click on + + align:start position:0% +all check out because you can click on + + + align:start position:0% +all check out because you can click on +what type of owners, what the status is + + align:start position:0% +what type of owners, what the status is + + + align:start position:0% +what type of owners, what the status is +and the type of thermal networks and + + align:start position:0% +and the type of thermal networks and + + + align:start position:0% +and the type of thermal networks and +just see that actually we have a lot of + + align:start position:0% +just see that actually we have a lot of + + + align:start position:0% +just see that actually we have a lot of +projects in this country and that + + align:start position:0% +projects in this country and that + + + align:start position:0% +projects in this country and that +there's huge opportunity for learning + + align:start position:0% +there's huge opportunity for learning + + + align:start position:0% +there's huge opportunity for learning +across projects and that is everything. + + align:start position:0% +across projects and that is everything. + + + align:start position:0% +across projects and that is everything. +[Applause] \ No newline at end of file diff --git a/0fEJFRKJN4U.txt b/0fEJFRKJN4U.txt new file mode 100644 index 0000000000000000000000000000000000000000..1e39534f4ca83f3e30d1b89842798ee2c983ecb6 --- /dev/null +++ b/0fEJFRKJN4U.txt @@ -0,0 +1,13795 @@ +align:start position:0% + +all right everyone so let's get + + align:start position:0% +all right everyone so let's get + + + align:start position:0% +all right everyone so let's get +started last lecture we introduced + + align:start position:0% +started last lecture we introduced + + + align:start position:0% +started last lecture we introduced +functions um and we saw some syntax + + align:start position:0% +functions um and we saw some syntax + + + align:start position:0% +functions um and we saw some syntax +around how to create functions but + + align:start position:0% +around how to create functions but + + + align:start position:0% +around how to create functions but +mostly we were interested in kind of + + align:start position:0% +mostly we were interested in kind of + + + align:start position:0% +mostly we were interested in kind of +motivating functions as a way for us to + + align:start position:0% +motivating functions as a way for us to + + + align:start position:0% +motivating functions as a way for us to +start writing really clean code code + + align:start position:0% +start writing really clean code code + + + align:start position:0% +start writing really clean code code +that's easy to debug and code that's + + align:start position:0% +that's easy to debug and code that's + + + align:start position:0% +that's easy to debug and code that's +easy to read in the future today we will + + align:start position:0% +easy to read in the future today we will + + + align:start position:0% +easy to read in the future today we will +uh continue our fun adventure with + + align:start position:0% +uh continue our fun adventure with + + + align:start position:0% +uh continue our fun adventure with +functions and uh we'll see how what it + + align:start position:0% +functions and uh we'll see how what it + + + align:start position:0% +functions and uh we'll see how what it +means to treat functions as + + align:start position:0% +means to treat functions as + + + align:start position:0% +means to treat functions as +objects so let's recall the example we + + align:start position:0% +objects so let's recall the example we + + + align:start position:0% +objects so let's recall the example we +talked about last lecture we created + + align:start position:0% +talked about last lecture we created + + + align:start position:0% +talked about last lecture we created +this + + align:start position:0% +this + + + align:start position:0% +this +function is even so the Syntax for + + align:start position:0% +function is even so the Syntax for + + + align:start position:0% +function is even so the Syntax for +creating a function uh is basically uh + + align:start position:0% +creating a function uh is basically uh + + + align:start position:0% +creating a function uh is basically uh +the keyword DF tells python we're + + align:start position:0% +the keyword DF tells python we're + + + align:start position:0% +the keyword DF tells python we're +defining a function we decide what name + + align:start position:0% +defining a function we decide what name + + + align:start position:0% +defining a function we decide what name +to give our function parentheses tells + + align:start position:0% +to give our function parentheses tells + + + align:start position:0% +to give our function parentheses tells +python in here we're going to name all + + align:start position:0% +python in here we're going to name all + + + align:start position:0% +python in here we're going to name all +the arguments all the inputs to the + + align:start position:0% +the arguments all the inputs to the + + + align:start position:0% +the arguments all the inputs to the +function the colon starts the body of + + align:start position:0% +function the colon starts the body of + + + align:start position:0% +function the colon starts the body of +the + + align:start position:0% +the + + + align:start position:0% +the +function the first part it's not + + align:start position:0% +function the first part it's not + + + align:start position:0% +function the first part it's not +required but should always kind of be in + + align:start position:0% +required but should always kind of be in + + + align:start position:0% +required but should always kind of be in +there uh as a way for us to implement + + align:start position:0% +there uh as a way for us to implement + + + align:start position:0% +there uh as a way for us to implement +abstraction is the called the dock + + align:start position:0% +abstraction is the called the dock + + + align:start position:0% +abstraction is the called the dock +string so this uh in green is the dock + + align:start position:0% +string so this uh in green is the dock + + + align:start position:0% +string so this uh in green is the dock +string triple quotes starts our dock + + align:start position:0% +string triple quotes starts our dock + + + align:start position:0% +string triple quotes starts our dock +string and triple quotes ends the dock + + align:start position:0% +string and triple quotes ends the dock + + + align:start position:0% +string and triple quotes ends the dock +string and you think of the dock string + + align:start position:0% +string and you think of the dock string + + + align:start position:0% +string and you think of the dock string +um also known as a specification as just + + align:start position:0% +um also known as a specification as just + + + align:start position:0% +um also known as a specification as just +a really long comment okay and in it + + align:start position:0% +a really long comment okay and in it + + + align:start position:0% +a really long comment okay and in it +it's uh and and the dock string is kind + + align:start position:0% +it's uh and and the dock string is kind + + + align:start position:0% +it's uh and and the dock string is kind +of I called it a contract between the + + align:start position:0% +of I called it a contract between the + + + align:start position:0% +of I called it a contract between the +person who writes the function and a + + align:start position:0% +person who writes the function and a + + + align:start position:0% +person who writes the function and a +person who uses the function and in the + + align:start position:0% +person who uses the function and in the + + + align:start position:0% +person who uses the function and in the +contract the person who writes the + + align:start position:0% +contract the person who writes the + + + align:start position:0% +contract the person who writes the +function basically says this function is + + align:start position:0% +function basically says this function is + + + align:start position:0% +function basically says this function is +going to take these inputs and I + + align:start position:0% +going to take these inputs and I + + + align:start position:0% +going to take these inputs and I +guarantee this function to work + + align:start position:0% +guarantee this function to work + + + align:start position:0% +guarantee this function to work +correctly when you give me these inputs + + align:start position:0% +correctly when you give me these inputs + + + align:start position:0% +correctly when you give me these inputs +of these types and these restrictions on + + align:start position:0% +of these types and these restrictions on + + + align:start position:0% +of these types and these restrictions on +them things like that + + align:start position:0% +them things like that + + + align:start position:0% +them things like that +and then you also State what the + + align:start position:0% +and then you also State what the + + + align:start position:0% +and then you also State what the +function is going to do and then you + + align:start position:0% +function is going to do and then you + + + align:start position:0% +function is going to do and then you +also State what the function will return + + align:start position:0% +also State what the function will return + + + align:start position:0% +also State what the function will return +okay in this particular function we have + + align:start position:0% +okay in this particular function we have + + + align:start position:0% +okay in this particular function we have +uh only one line This is the body of the + + align:start position:0% +uh only one line This is the body of the + + + align:start position:0% +uh only one line This is the body of the +function but you've hopefully seen + + align:start position:0% +function but you've hopefully seen + + + align:start position:0% +function but you've hopefully seen +functions that are a little bit longer + + align:start position:0% +functions that are a little bit longer + + + align:start position:0% +functions that are a little bit longer +as you did the practice from last + + align:start position:0% +as you did the practice from last + + + align:start position:0% +as you did the practice from last +lecture um and the body of the function + + align:start position:0% +lecture um and the body of the function + + + align:start position:0% +lecture um and the body of the function +itself so the lines of code are + + align:start position:0% +itself so the lines of code are + + + align:start position:0% +itself so the lines of code are +basically lines of code that we've seen + + align:start position:0% +basically lines of code that we've seen + + + align:start position:0% +basically lines of code that we've seen +before okay there's nothing sort of + + align:start position:0% +before okay there's nothing sort of + + + align:start position:0% +before okay there's nothing sort of +special about that except step for lines + + align:start position:0% +special about that except step for lines + + + align:start position:0% +special about that except step for lines +that start with a return so lines that + + align:start position:0% +that start with a return so lines that + + + align:start position:0% +that start with a return so lines that +start with a return basically uh tell + + align:start position:0% +start with a return basically uh tell + + + align:start position:0% +start with a return basically uh tell +python that as soon as I see this line + + align:start position:0% +python that as soon as I see this line + + + align:start position:0% +python that as soon as I see this line +with a return hit uh in when I'm + + align:start position:0% +with a return hit uh in when I'm + + + align:start position:0% +with a return hit uh in when I'm +executing my function I need to stop + + align:start position:0% +executing my function I need to stop + + + align:start position:0% +executing my function I need to stop +executing this function take the value + + align:start position:0% +executing this function take the value + + + align:start position:0% +executing this function take the value +associated with this return and pass it + + align:start position:0% +associated with this return and pass it + + + align:start position:0% +associated with this return and pass it +back to whoever called me okay a + + align:start position:0% +back to whoever called me okay a + + + align:start position:0% +back to whoever called me okay a +function always returns something okay + + align:start position:0% +function always returns something okay + + + align:start position:0% +function always returns something okay +in this particular case the function + + align:start position:0% +in this particular case the function + + + align:start position:0% +in this particular case the function +will return either true or false a + + align:start position:0% +will return either true or false a + + + align:start position:0% +will return either true or false a +Boolean but you can write functions I + + align:start position:0% +Boolean but you can write functions I + + + align:start position:0% +Boolean but you can write functions I +return integers floats uh strings things + + align:start position:0% +return integers floats uh strings things + + + align:start position:0% +return integers floats uh strings things +like + + align:start position:0% +like + + + align:start position:0% +like +that uh in this case yeah this is what + + align:start position:0% +that uh in this case yeah this is what + + + align:start position:0% +that uh in this case yeah this is what +is returned it is possible and we + + align:start position:0% +is returned it is possible and we + + + align:start position:0% +is returned it is possible and we +actually saw this in one of the UT + + align:start position:0% +actually saw this in one of the UT + + + align:start position:0% +actually saw this in one of the UT +triats as we were writing our code it is + + align:start position:0% +triats as we were writing our code it is + + + align:start position:0% +triats as we were writing our code it is +possible to write a function that + + align:start position:0% +possible to write a function that + + + align:start position:0% +possible to write a function that +doesn't actually return anything + + align:start position:0% +doesn't actually return anything + + + align:start position:0% +doesn't actually return anything +explicitly so here is the iseven + + align:start position:0% +explicitly so here is the iseven + + + align:start position:0% +explicitly so here is the iseven +function and inside the body the only + + align:start position:0% +function and inside the body the only + + + align:start position:0% +function and inside the body the only +change I've made is I've eliminated the + + align:start position:0% +change I've made is I've eliminated the + + + align:start position:0% +change I've made is I've eliminated the +little return keyword but otherwise the + + align:start position:0% +little return keyword but otherwise the + + + align:start position:0% +little return keyword but otherwise the +work that is done is the same so here + + align:start position:0% +work that is done is the same so here + + + align:start position:0% +work that is done is the same so here +I'm just calculating whether the + + align:start position:0% +I'm just calculating whether the + + + align:start position:0% +I'm just calculating whether the +remainder is zero or not so this line of + + align:start position:0% +remainder is zero or not so this line of + + + align:start position:0% +remainder is zero or not so this line of +code when the uh when the function is + + align:start position:0% +code when the uh when the function is + + + align:start position:0% +code when the uh when the function is +executed just uh is replaced with either + + align:start position:0% +executed just uh is replaced with either + + + align:start position:0% +executed just uh is replaced with either +true or false okay notice this function + + align:start position:0% +true or false okay notice this function + + + align:start position:0% +true or false okay notice this function +doesn't have a return keyword but all + + align:start position:0% +doesn't have a return keyword but all + + + align:start position:0% +doesn't have a return keyword but all +functions return something so while a + + align:start position:0% +functions return something so while a + + + align:start position:0% +functions return something so while a +function is being executed because of a + + align:start position:0% +function is being executed because of a + + + align:start position:0% +function is being executed because of a +function call if the function reaches + + align:start position:0% +function call if the function reaches + + + align:start position:0% +function call if the function reaches +the end of all of these indented lines + + align:start position:0% +the end of all of these indented lines + + + align:start position:0% +the end of all of these indented lines +here right any everything that's + + align:start position:0% +here right any everything that's + + + align:start position:0% +here right any everything that's +indented if it reaches the end and no + + align:start position:0% +indented if it reaches the end and no + + + align:start position:0% +indented if it reaches the end and no +return statement has been hit then + + align:start position:0% +return statement has been hit then + + + align:start position:0% +return statement has been hit then +python automatically returns none okay + + align:start position:0% +python automatically returns none okay + + + align:start position:0% +python automatically returns none okay +so this is the line without a return + + align:start position:0% +so this is the line without a return + + + align:start position:0% +so this is the line without a return +statement you can think of this uh code + + align:start position:0% +statement you can think of this uh code + + + align:start position:0% +statement you can think of this uh code +AS basically behind the scenes python + + align:start position:0% +AS basically behind the scenes python + + + align:start position:0% +AS basically behind the scenes python +putting this little line at the bottom + + align:start position:0% +putting this little line at the bottom + + + align:start position:0% +putting this little line at the bottom +that says return none okay now this is + + align:start position:0% +that says return none okay now this is + + + align:start position:0% +that says return none okay now this is +not something that we would ever write + + align:start position:0% +not something that we would ever write + + + align:start position:0% +not something that we would ever write +you just do the operations maybe you + + align:start position:0% +you just do the operations maybe you + + + align:start position:0% +you just do the operations maybe you +print some stuff out and then you just + + align:start position:0% +print some stuff out and then you just + + + align:start position:0% +print some stuff out and then you just +omit the return keyw if you want to + + align:start position:0% +omit the return keyw if you want to + + + align:start position:0% +omit the return keyw if you want to +return none from the function okay and + + align:start position:0% +return none from the function okay and + + + align:start position:0% +return none from the function okay and +none is this uh nun type uh is is a a + + align:start position:0% +none is this uh nun type uh is is a a + + + align:start position:0% +none is this uh nun type uh is is a a +value that is of Type n type we talked + + align:start position:0% +value that is of Type n type we talked + + + align:start position:0% +value that is of Type n type we talked +about it back in maybe lecture one or + + align:start position:0% +about it back in maybe lecture one or + + + align:start position:0% +about it back in maybe lecture one or +two and we haven't really used it that + + align:start position:0% +two and we haven't really used it that + + + align:start position:0% +two and we haven't really used it that +much + + align:start position:0% +much + + + align:start position:0% +much +since but basically you think of it as + + align:start position:0% +since but basically you think of it as + + + align:start position:0% +since but basically you think of it as +just having the type none type and + + align:start position:0% +just having the type none type and + + + align:start position:0% +just having the type none type and +there's just one value associated with + + align:start position:0% +there's just one value associated with + + + align:start position:0% +there's just one value associated with +it none and usually we use this value to + + align:start position:0% +it none and usually we use this value to + + + align:start position:0% +it none and usually we use this value to +represent the absence of a value in our + + align:start position:0% +represent the absence of a value in our + + + align:start position:0% +represent the absence of a value in our +code so let me just run some code first + + align:start position:0% +code so let me just run some code first + + + align:start position:0% +code so let me just run some code first +just to show you exactly some of the + + align:start position:0% +just to show you exactly some of the + + + align:start position:0% +just to show you exactly some of the +kind of uh things you might observe when + + align:start position:0% +kind of uh things you might observe when + + + align:start position:0% +kind of uh things you might observe when +when you write code that doesn't have a + + align:start position:0% +when you write code that doesn't have a + + + align:start position:0% +when you write code that doesn't have a +return statement so here uh I promise + + align:start position:0% +return statement so here uh I promise + + + align:start position:0% +return statement so here uh I promise +this is the last time we're going to see + + align:start position:0% +this is the last time we're going to see + + + align:start position:0% +this is the last time we're going to see +is even um so here I have two versions + + align:start position:0% +is even um so here I have two versions + + + align:start position:0% +is even um so here I have two versions +of the is even function so I have one + + align:start position:0% +of the is even function so I have one + + + align:start position:0% +of the is even function so I have one +that I named is even with return and I + + align:start position:0% +that I named is even with return and I + + + align:start position:0% +that I named is even with return and I +have one that is named is even without + + align:start position:0% +have one that is named is even without + + + align:start position:0% +have one that is named is even without +return okay they do very similar things + + align:start position:0% +return okay they do very similar things + + + align:start position:0% +return okay they do very similar things +the difference is that this one has a + + align:start position:0% +the difference is that this one has a + + + align:start position:0% +the difference is that this one has a +return statement where I return whether + + align:start position:0% +return statement where I return whether + + + align:start position:0% +return statement where I return whether +the remainder is equal to zero and this + + align:start position:0% +the remainder is equal to zero and this + + + align:start position:0% +the remainder is equal to zero and this +one has no return statement but it just + + align:start position:0% +one has no return statement but it just + + + align:start position:0% +one has no return statement but it just +prints whether the return uh the + + align:start position:0% +prints whether the return uh the + + + align:start position:0% +prints whether the return uh the +remainder is equal to zero okay so let's + + align:start position:0% +remainder is equal to zero okay so let's + + + align:start position:0% +remainder is equal to zero okay so let's +look at uh running the code with uh is + + align:start position:0% +look at uh running the code with uh is + + + align:start position:0% +look at uh running the code with uh is +even with return and as we're doing so + + align:start position:0% +even with return and as we're doing so + + + align:start position:0% +even with return and as we're doing so +this first uh function will be a recap + + align:start position:0% +this first uh function will be a recap + + + align:start position:0% +this first uh function will be a recap +of last lecture kind of tracing through + + align:start position:0% +of last lecture kind of tracing through + + + align:start position:0% +of last lecture kind of tracing through +what happens when we make a function + + align:start position:0% +what happens when we make a function + + + align:start position:0% +what happens when we make a function +call so I've uncommented this line and + + align:start position:0% +call so I've uncommented this line and + + + align:start position:0% +call so I've uncommented this line and +now I'm + + align:start position:0% +now I'm + + + align:start position:0% +now I'm +running line + + align:start position:0% +running line + + + align:start position:0% +running line +13 so when python sees this file it + + align:start position:0% +13 so when python sees this file it + + + align:start position:0% +13 so when python sees this file it +basically sees this function definition + + align:start position:0% +basically sees this function definition + + + align:start position:0% +basically sees this function definition +and this is not code that runs yet right + + align:start position:0% +and this is not code that runs yet right + + + align:start position:0% +and this is not code that runs yet right +it's just telling python that I've + + align:start position:0% +it's just telling python that I've + + + align:start position:0% +it's just telling python that I've +created this function inside memory when + + align:start position:0% +created this function inside memory when + + + align:start position:0% +created this function inside memory when +I have this line being run that's when + + align:start position:0% +I have this line being run that's when + + + align:start position:0% +I have this line being run that's when +the function is actually being called + + align:start position:0% +the function is actually being called + + + align:start position:0% +the function is actually being called +and actually being run so I is replaced + + align:start position:0% +and actually being run so I is replaced + + + align:start position:0% +and actually being run so I is replaced +with a parameter + + align:start position:0% +with a parameter + + + align:start position:0% +with a parameter +three and at this point the body of the + + align:start position:0% +three and at this point the body of the + + + align:start position:0% +three and at this point the body of the +function is executed so the first thing + + align:start position:0% +function is executed so the first thing + + + align:start position:0% +function is executed so the first thing +that we tell the function to do is print + + align:start position:0% +that we tell the function to do is print + + + align:start position:0% +that we tell the function to do is print +the string with return so if I run it + + align:start position:0% +the string with return so if I run it + + + align:start position:0% +the string with return so if I run it +you'll see it prints with + + align:start position:0% +you'll see it prints with + + + align:start position:0% +you'll see it prints with +return then it calculates this variable + + align:start position:0% +return then it calculates this variable + + + align:start position:0% +return then it calculates this variable +remainder which is going to be one right + + align:start position:0% +remainder which is going to be one right + + + align:start position:0% +remainder which is going to be one right +because 3% 2 equals 1 and then I'm going + + align:start position:0% +because 3% 2 equals 1 and then I'm going + + + align:start position:0% +because 3% 2 equals 1 and then I'm going +to return whether one equal equal zero + + align:start position:0% +to return whether one equal equal zero + + + align:start position:0% +to return whether one equal equal zero +so that's going to be false so as soon + + align:start position:0% +so that's going to be false so as soon + + + align:start position:0% +so that's going to be false so as soon +as we see this return statement python + + align:start position:0% +as we see this return statement python + + + align:start position:0% +as we see this return statement python +returns out of this function call and + + align:start position:0% +returns out of this function call and + + + align:start position:0% +returns out of this function call and +replaces the function call entirely with + + align:start position:0% +replaces the function call entirely with + + + align:start position:0% +replaces the function call entirely with +the return value so this entire line + + align:start position:0% +the return value so this entire line + + + align:start position:0% +the return value so this entire line +after the py uh the function call is + + align:start position:0% +after the py uh the function call is + + + align:start position:0% +after the py uh the function call is +executed is replaced with false so I've + + align:start position:0% +executed is replaced with false so I've + + + align:start position:0% +executed is replaced with false so I've +just noted that + + align:start position:0% +just noted that + + + align:start position:0% +just noted that +here we're not doing anything with this + + align:start position:0% +here we're not doing anything with this + + + align:start position:0% +here we're not doing anything with this +return right all we're doing is making + + align:start position:0% +return right all we're doing is making + + + align:start position:0% +return right all we're doing is making +the function call and it just kind of + + align:start position:0% +the function call and it just kind of + + + align:start position:0% +the function call and it just kind of +sits on line + + align:start position:0% +sits on line + + + align:start position:0% +sits on line +13 in order to see the result of the + + align:start position:0% +13 in order to see the result of the + + + align:start position:0% +13 in order to see the result of the +function call we saw last lecture that + + align:start position:0% +function call we saw last lecture that + + + align:start position:0% +function call we saw last lecture that +we actually um wrap the function call + + align:start position:0% +we actually um wrap the function call + + + align:start position:0% +we actually um wrap the function call +around a print statement right and + + align:start position:0% +around a print statement right and + + + align:start position:0% +around a print statement right and +function calls in that sense are kind of + + align:start position:0% +function calls in that sense are kind of + + + align:start position:0% +function calls in that sense are kind of +just Expressions right they do some work + + align:start position:0% +just Expressions right they do some work + + + align:start position:0% +just Expressions right they do some work +python evalu them to some value and then + + align:start position:0% +python evalu them to some value and then + + + align:start position:0% +python evalu them to some value and then +replaces that function call with the + + align:start position:0% +replaces that function call with the + + + align:start position:0% +replaces that function call with the +value so if we wrap is even with return + + align:start position:0% +value so if we wrap is even with return + + + align:start position:0% +value so if we wrap is even with return +three this function call around with a + + align:start position:0% +three this function call around with a + + + align:start position:0% +three this function call around with a +print statement python does the whole + + align:start position:0% +print statement python does the whole + + + align:start position:0% +print statement python does the whole +thing again I is three it returns false + + align:start position:0% +thing again I is three it returns false + + + align:start position:0% +thing again I is three it returns false +and this line effectively becomes print + + align:start position:0% +and this line effectively becomes print + + + align:start position:0% +and this line effectively becomes print +parenthesis false and we know what that + + align:start position:0% +parenthesis false and we know what that + + + align:start position:0% +parenthesis false and we know what that +does right it just prints false to the + + align:start position:0% +does right it just prints false to the + + + align:start position:0% +does right it just prints false to the +screen and there it goes right notice we + + align:start position:0% +screen and there it goes right notice we + + + align:start position:0% +screen and there it goes right notice we +still did this print statement because + + align:start position:0% +still did this print statement because + + + align:start position:0% +still did this print statement because +as part of the function body we tell it + + align:start position:0% +as part of the function body we tell it + + + align:start position:0% +as part of the function body we tell it +to do this + + align:start position:0% +to do this + + + align:start position:0% +to do this +print everyone okay so far + + align:start position:0% + + + + align:start position:0% + +okay so now let's see what happens when + + align:start position:0% +okay so now let's see what happens when + + + align:start position:0% +okay so now let's see what happens when +we run this function is even without + + align:start position:0% +we run this function is even without + + + align:start position:0% +we run this function is even without +return so very similar I've just created + + align:start position:0% +return so very similar I've just created + + + align:start position:0% +return so very similar I've just created +an extra uh parameter here or variable + + align:start position:0% +an extra uh parameter here or variable + + + align:start position:0% +an extra uh parameter here or variable +here just to show you that you can um so + + align:start position:0% +here just to show you that you can um so + + + align:start position:0% +here just to show you that you can um so +this function uh is even without return + + align:start position:0% +this function uh is even without return + + + align:start position:0% +this function uh is even without return +three is being run on line 27 so I is + + align:start position:0% +three is being run on line 27 so I is + + + align:start position:0% +three is being run on line 27 so I is +three this function will print without + + align:start position:0% +three this function will print without + + + align:start position:0% +three this function will print without +return and then it calculates remainder + + align:start position:0% +return and then it calculates remainder + + + align:start position:0% +return and then it calculates remainder +to be one and then has REM will be false + + align:start position:0% +to be one and then has REM will be false + + + align:start position:0% +to be one and then has REM will be false +right so the variable has REM will have + + align:start position:0% +right so the variable has REM will have + + + align:start position:0% +right so the variable has REM will have +a value of false and then as part of the + + align:start position:0% +a value of false and then as part of the + + + align:start position:0% +a value of false and then as part of the +function body we're going to print the + + align:start position:0% +function body we're going to print the + + + align:start position:0% +function body we're going to print the +value of has R which is false so this + + align:start position:0% +value of has R which is false so this + + + align:start position:0% +value of has R which is false so this +line here will actually print for me + + align:start position:0% +line here will actually print for me + + + align:start position:0% +line here will actually print for me +without return and then this thing false + + align:start position:0% +without return and then this thing false + + + align:start position:0% +without return and then this thing false +okay and then the function has no return + + align:start position:0% +okay and then the function has no return + + + align:start position:0% +okay and then the function has no return +statement explicitly in there so you + + align:start position:0% +statement explicitly in there so you + + + align:start position:0% +statement explicitly in there so you +think about it like python kind of + + align:start position:0% +think about it like python kind of + + + align:start position:0% +think about it like python kind of +implicitly adds this return none at the + + align:start position:0% +implicitly adds this return none at the + + + align:start position:0% +implicitly adds this return none at the +end of it the function call we don't add + + align:start position:0% +end of it the function call we don't add + + + align:start position:0% +end of it the function call we don't add +this I just wrote it there just to show + + align:start position:0% +this I just wrote it there just to show + + + align:start position:0% +this I just wrote it there just to show +you that python would add a line such as + + align:start position:0% +you that python would add a line such as + + + align:start position:0% +you that python would add a line such as +this when it reaches the end of the + + align:start position:0% +this when it reaches the end of the + + + align:start position:0% +this when it reaches the end of the +function but you would never add it so + + align:start position:0% +function but you would never add it so + + + align:start position:0% +function but you would never add it so +that means that the entire function call + + align:start position:0% +that means that the entire function call + + + align:start position:0% +that means that the entire function call +is replaced with + + align:start position:0% +is replaced with + + + align:start position:0% +is replaced with +none + + align:start position:0% +none + + + align:start position:0% +none +okay + + align:start position:0% +okay + + + align:start position:0% +okay +yes what happens when you in + + align:start position:0% +yes what happens when you in + + + align:start position:0% +yes what happens when you in +the return what happens when you put + + align:start position:0% +the return what happens when you put + + + align:start position:0% +the return what happens when you put +print in the definition versus around + + align:start position:0% +print in the definition versus around + + + align:start position:0% +print in the definition versus around +the function + + align:start position:0% +the function + + + align:start position:0% +the function +call versus like when you put in the + + align:start position:0% +call versus like when you put in the + + + align:start position:0% +call versus like when you put in the +versus when you put return in the + + align:start position:0% +versus when you put return in the + + + align:start position:0% +versus when you put return in the +definition so that's the next line so in + + align:start position:0% +definition so that's the next line so in + + + align:start position:0% +definition so that's the next line so in +the next one if we were to do what we + + align:start position:0% +the next one if we were to do what we + + + align:start position:0% +the next one if we were to do what we +did before which is let's print the + + align:start position:0% +did before which is let's print the + + + align:start position:0% +did before which is let's print the +result of the function call well python + + align:start position:0% +result of the function call well python + + + align:start position:0% +result of the function call well python +will do everything we just did right so + + align:start position:0% +will do everything we just did right so + + + align:start position:0% +will do everything we just did right so +it'll print without return it'll print + + align:start position:0% +it'll print without return it'll print + + + align:start position:0% +it'll print without return it'll print +false but then it'll additionally print + + align:start position:0% +false but then it'll additionally print + + + align:start position:0% +false but then it'll additionally print +the return from the function call so if + + align:start position:0% +the return from the function call so if + + + align:start position:0% +the return from the function call so if +the return is none this line effectively + + align:start position:0% +the return is none this line effectively + + + align:start position:0% +the return is none this line effectively +becomes print + + align:start position:0% +becomes print + + + align:start position:0% +becomes print +none so what we end up seeing or what + + align:start position:0% +none so what we end up seeing or what + + + align:start position:0% +none so what we end up seeing or what +the user would end up seeing if they + + align:start position:0% +the user would end up seeing if they + + + align:start position:0% +the user would end up seeing if they +actually run this program is they'll see + + align:start position:0% +actually run this program is they'll see + + + align:start position:0% +actually run this program is they'll see +without return they see false and then + + align:start position:0% +without return they see false and then + + + align:start position:0% +without return they see false and then +they see this extraneous none in the + + align:start position:0% +they see this extraneous none in the + + + align:start position:0% +they see this extraneous none in the +console right so you'll see probably + + align:start position:0% +console right so you'll see probably + + + align:start position:0% +console right so you'll see probably +this in problem set two you'll probably + + align:start position:0% +this in problem set two you'll probably + + + align:start position:0% +this in problem set two you'll probably +encounter an error such as this and + + align:start position:0% +encounter an error such as this and + + + align:start position:0% +encounter an error such as this and +maybe problem set three but don't be + + align:start position:0% +maybe problem set three but don't be + + + align:start position:0% +maybe problem set three but don't be +scared whenever you see a none out in + + align:start position:0% +scared whenever you see a none out in + + + align:start position:0% +scared whenever you see a none out in +the console it just means you have to be + + align:start position:0% +the console it just means you have to be + + + align:start position:0% +the console it just means you have to be +careful about the function that was + + align:start position:0% +careful about the function that was + + + align:start position:0% +careful about the function that was +called right you probably forgot to + + align:start position:0% +called right you probably forgot to + + + align:start position:0% +called right you probably forgot to +return something and instead we're we're + + align:start position:0% +return something and instead we're we're + + + align:start position:0% +return something and instead we're we're +just you know printing the correct value + + align:start position:0% +just you know printing the correct value + + + align:start position:0% +just you know printing the correct value +within the function but just never + + align:start position:0% +within the function but just never + + + align:start position:0% +within the function but just never +returned it right so that's just uh + + align:start position:0% +returned it right so that's just uh + + + align:start position:0% +returned it right so that's just uh +something to be wary + + align:start position:0% + + + + align:start position:0% + +of yeah so that's that's a good question + + align:start position:0% +of yeah so that's that's a good question + + + align:start position:0% +of yeah so that's that's a good question +should you always use return it depends + + align:start position:0% +should you always use return it depends + + + align:start position:0% +should you always use return it depends +on what you want the function to do most + + align:start position:0% +on what you want the function to do most + + + align:start position:0% +on what you want the function to do most +functions are useful because they go off + + align:start position:0% +functions are useful because they go off + + + align:start position:0% +functions are useful because they go off +on their own they do a task and they get + + align:start position:0% +on their own they do a task and they get + + + align:start position:0% +on their own they do a task and they get +a value at the end and they pass the + + align:start position:0% +a value at the end and they pass the + + + align:start position:0% +a value at the end and they pass the +value back to whoever called it and then + + align:start position:0% +value back to whoever called it and then + + + align:start position:0% +value back to whoever called it and then +you can use that function with many + + align:start position:0% +you can use that function with many + + + align:start position:0% +you can use that function with many +different inputs to give you many + + align:start position:0% +different inputs to give you many + + + align:start position:0% +different inputs to give you many +different outputs so usually you'd want + + align:start position:0% +different outputs so usually you'd want + + + align:start position:0% +different outputs so usually you'd want +to make functions that return something + + align:start position:0% +to make functions that return something + + + align:start position:0% +to make functions that return something +that you can then do something else with + + align:start position:0% +that you can then do something else with + + + align:start position:0% +that you can then do something else with +further in in another part of the + + align:start position:0% +further in in another part of the + + + align:start position:0% +further in in another part of the +program the the the prints within the + + align:start position:0% +program the the the prints within the + + + align:start position:0% +program the the the prints within the +within the functions should usually be + + align:start position:0% +within the functions should usually be + + + align:start position:0% +within the functions should usually be +maybe for debugging or for or you know + + align:start position:0% +maybe for debugging or for or you know + + + align:start position:0% +maybe for debugging or for or you know +like maybe the status of the function + + align:start position:0% +like maybe the status of the function + + + align:start position:0% +like maybe the status of the function +you know what part is it's executing or + + align:start position:0% +you know what part is it's executing or + + + align:start position:0% +you know what part is it's executing or +something like that okay and then when + + align:start position:0% +something like that okay and then when + + + align:start position:0% +something like that okay and then when +you run the function then it will give + + align:start position:0% +you run the function then it will give + + + align:start position:0% +you run the function then it will give +you the return but you run print and the + + align:start position:0% +you the return but you run print and the + + + align:start position:0% +you the return but you run print and the +function that's what it does exactly + + align:start position:0% +function that's what it does exactly + + + align:start position:0% +function that's what it does exactly +yeah if the function is not returning + + align:start position:0% +yeah if the function is not returning + + + align:start position:0% +yeah if the function is not returning +anything then it'll do it'll print + + align:start position:0% +anything then it'll do it'll print + + + align:start position:0% +anything then it'll do it'll print +none right yeah but if the function is + + align:start position:0% +none right yeah but if the function is + + + align:start position:0% +none right yeah but if the function is +returning something it will print right + + align:start position:0% +returning something it will print right + + + align:start position:0% +returning something it will print right +this if you wrap it with a print it'll + + align:start position:0% +this if you wrap it with a print it'll + + + align:start position:0% +this if you wrap it with a print it'll +print whatever got + + align:start position:0% + + + + align:start position:0% + +returned + + align:start position:0% +returned + + + align:start position:0% +returned +okay so let's have you uh work on this + + align:start position:0% +okay so let's have you uh work on this + + + align:start position:0% +okay so let's have you uh work on this +actually there's nothing to to write but + + align:start position:0% +actually there's nothing to to write but + + + align:start position:0% +actually there's nothing to to write but +think about it so I've got four lines of + + align:start position:0% +think about it so I've got four lines of + + + align:start position:0% +think about it so I've got four lines of +code here add one comma 2 print wrap + + align:start position:0% +code here add one comma 2 print wrap + + + align:start position:0% +code here add one comma 2 print wrap +that around the print statement Mt three + + align:start position:0% +that around the print statement Mt three + + + align:start position:0% +that around the print statement Mt three +comma four and then add add that around + + align:start position:0% +comma four and then add add that around + + + align:start position:0% +comma four and then add add that around +a print statement so try to trace + + align:start position:0% +a print statement so try to trace + + + align:start position:0% +a print statement so try to trace +through and tell me what + + align:start position:0% +through and tell me what + + + align:start position:0% +through and tell me what +outputs + + align:start position:0% +outputs + + + align:start position:0% +outputs +um each each function call will give me + + align:start position:0% +um each each function call will give me + + + align:start position:0% +um each each function call will give me +right so add one comma two what happens + + align:start position:0% +right so add one comma two what happens + + + align:start position:0% +right so add one comma two what happens +what do you think the output of this + + align:start position:0% +what do you think the output of this + + + align:start position:0% +what do you think the output of this +function is what gets printed to the + + align:start position:0% + + + + align:start position:0% + +screen what is + + align:start position:0% + + + + align:start position:0% + +it am I telling it to print anything + + align:start position:0% +it am I telling it to print anything + + + align:start position:0% +it am I telling it to print anything +that's the question yeah so nothing is + + align:start position:0% +that's the question yeah so nothing is + + + align:start position:0% +that's the question yeah so nothing is +actually printed to the screen right + + align:start position:0% +actually printed to the screen right + + + align:start position:0% +actually printed to the screen right +because in the function called add comma + + align:start position:0% +because in the function called add comma + + + align:start position:0% +because in the function called add comma +2 right we basically map the parameters + + align:start position:0% +2 right we basically map the parameters + + + align:start position:0% +2 right we basically map the parameters +one at a time x is one y is two that was + + align:start position:0% +one at a time x is one y is two that was + + + align:start position:0% +one at a time x is one y is two that was +good we return three + + align:start position:0% +good we return three + + + align:start position:0% +good we return three +and so this entire function call is + + align:start position:0% +and so this entire function call is + + + align:start position:0% +and so this entire function call is +replaced with + + align:start position:0% +replaced with + + + align:start position:0% +replaced with +three but we never told the the that + + align:start position:0% +three but we never told the the that + + + align:start position:0% +three but we never told the the that +line of code to print that result right + + align:start position:0% +line of code to print that result right + + + align:start position:0% +line of code to print that result right +so there's nothing printed in this case + + align:start position:0% +so there's nothing printed in this case + + + align:start position:0% +so there's nothing printed in this case +well what if we + + align:start position:0% +well what if we + + + align:start position:0% +well what if we +wrap uh this in a print + + align:start position:0% + + + + align:start position:0% + +statement is anything printed in this + + align:start position:0% +statement is anything printed in this + + + align:start position:0% +statement is anything printed in this +case yes what is + + align:start position:0% +case yes what is + + + align:start position:0% +case yes what is +printed yeah exactly right the ad itself + + align:start position:0% +printed yeah exactly right the ad itself + + + align:start position:0% +printed yeah exactly right the ad itself +gives me five and so I'm telling it to + + align:start position:0% +gives me five and so I'm telling it to + + + align:start position:0% +gives me five and so I'm telling it to +print + + align:start position:0% +print + + + align:start position:0% +print +five what about the next one Mt what is + + align:start position:0% +five what about the next one Mt what is + + + align:start position:0% +five what about the next one Mt what is +that four 3 + + align:start position:0% +that four 3 + + + align:start position:0% +that four 3 +four is anything printed as a result of + + align:start position:0% +four is anything printed as a result of + + + align:start position:0% +four is anything printed as a result of +running this + + align:start position:0% + + + + align:start position:0% + +line I heard some yes some + + align:start position:0% +line I heard some yes some + + + align:start position:0% +line I heard some yes some +no yeah the print is in the function + + align:start position:0% +no yeah the print is in the function + + + align:start position:0% +no yeah the print is in the function +exactly so just because it's a function + + align:start position:0% +exactly so just because it's a function + + + align:start position:0% +exactly so just because it's a function +call doesn't mean we don't print + + align:start position:0% +call doesn't mean we don't print + + + align:start position:0% +call doesn't mean we don't print +anything right we need to check out what + + align:start position:0% +anything right we need to check out what + + + align:start position:0% +anything right we need to check out what +the function is actually doing so in + + align:start position:0% +the function is actually doing so in + + + align:start position:0% +the function is actually doing so in +Mt um X gets mapped to three y gets + + align:start position:0% +Mt um X gets mapped to three y gets + + + align:start position:0% +Mt um X gets mapped to three y gets +mapped to four and the function body + + align:start position:0% +mapped to four and the function body + + + align:start position:0% +mapped to four and the function body +itself says to print the result so this + + align:start position:0% +itself says to print the result so this + + + align:start position:0% +itself says to print the result so this +will print as a part of the body + + align:start position:0% +will print as a part of the body + + + align:start position:0% +will print as a part of the body +right + + align:start position:0% + + + + align:start position:0% + +um prints the + + align:start position:0% + + + + align:start position:0% + +12 anything else at + + align:start position:0% +12 anything else at + + + align:start position:0% +12 anything else at +Prince + + align:start position:0% +Prince + + + align:start position:0% +Prince +no and lastly what if we put a print + + align:start position:0% +no and lastly what if we put a print + + + align:start position:0% +no and lastly what if we put a print +statement around the + + align:start position:0% +statement around the + + + align:start position:0% +statement around the +Mt 4 + + align:start position:0% +Mt 4 + + + align:start position:0% +Mt 4 +five what will that + + align:start position:0% +five what will that + + + align:start position:0% +five what will that +print yeah exactly 20 than none so the + + align:start position:0% +print yeah exactly 20 than none so the + + + align:start position:0% +print yeah exactly 20 than none so the +Mt itself is going to print same as + + align:start position:0% +Mt itself is going to print same as + + + align:start position:0% +Mt itself is going to print same as +there it prints the + + align:start position:0% +there it prints the + + + align:start position:0% +there it prints the +20 so the function call returns + + align:start position:0% +20 so the function call returns + + + align:start position:0% +20 so the function call returns +none so this entire function called + + align:start position:0% +none so this entire function called + + + align:start position:0% +none so this entire function called +basically is repl repl with none and the + + align:start position:0% +basically is repl repl with none and the + + + align:start position:0% +basically is repl repl with none and the +line then becomes print none so this + + align:start position:0% +line then becomes print none so this + + + align:start position:0% +line then becomes print none so this +will print uh the none to the screen so + + align:start position:0% +will print uh the none to the screen so + + + align:start position:0% +will print uh the none to the screen so +there's actually four uh four printouts + + align:start position:0% +there's actually four uh four printouts + + + align:start position:0% +there's actually four uh four printouts +generated from these four lines right + + align:start position:0% +generated from these four lines right + + + align:start position:0% +generated from these four lines right +the first one generates nothing but the + + align:start position:0% +the first one generates nothing but the + + + align:start position:0% +the first one generates nothing but the +last one generates two lines of print + + align:start position:0% +last one generates two lines of print + + + align:start position:0% +last one generates two lines of print +outs any questions about this example + + align:start position:0% +outs any questions about this example + + + align:start position:0% +outs any questions about this example +yes you go over + + align:start position:0% +yes you go over + + + align:start position:0% +yes you go over +white this one here yeah so the Mt um + + align:start position:0% +white this one here yeah so the Mt um + + + align:start position:0% +white this one here yeah so the Mt um +check out what it's doing it's it's + + align:start position:0% +check out what it's doing it's it's + + + align:start position:0% +check out what it's doing it's it's +doing a print statement so that 20 gets + + align:start position:0% +doing a print statement so that 20 gets + + + align:start position:0% +doing a print statement so that 20 gets +printed out to the console but what's + + align:start position:0% +printed out to the console but what's + + + align:start position:0% +printed out to the console but what's +the return value of + + align:start position:0% + + + + align:start position:0% + +maltt there is no return right so if + + align:start position:0% +maltt there is no return right so if + + + align:start position:0% +maltt there is no return right so if +there's no return python adds the none + + align:start position:0% +there's no return python adds the none + + + align:start position:0% +there's no return python adds the none +right that's just something that's + + align:start position:0% +right that's just something that's + + + align:start position:0% +right that's just something that's +implicitly done so the return from malt + + align:start position:0% +implicitly done so the return from malt + + + align:start position:0% +implicitly done so the return from malt +because it doesn't actually have an + + align:start position:0% +because it doesn't actually have an + + + align:start position:0% +because it doesn't actually have an +explicit return is none so we're asking + + align:start position:0% +explicit return is none so we're asking + + + align:start position:0% +explicit return is none so we're asking +it to print the return which is + + align:start position:0% +it to print the return which is + + + align:start position:0% +it to print the return which is +n + + align:start position:0% +n + + + align:start position:0% +n +okay so a couple words on return versus + + align:start position:0% +okay so a couple words on return versus + + + align:start position:0% +okay so a couple words on return versus +print + + align:start position:0% +print + + + align:start position:0% +print +so the return only has a meaning inside + + align:start position:0% +so the return only has a meaning inside + + + align:start position:0% +so the return only has a meaning inside +a function so as an example if I just + + align:start position:0% +a function so as an example if I just + + + align:start position:0% +a function so as an example if I just +have this uh file open and I have return + + align:start position:0% +have this uh file open and I have return + + + align:start position:0% +have this uh file open and I have return +five just randomly that's not within a + + align:start position:0% +five just randomly that's not within a + + + align:start position:0% +five just randomly that's not within a +function definition already I'm in + + align:start position:0% +function definition already I'm in + + + align:start position:0% +function definition already I'm in +trouble you see that red X and if I run + + align:start position:0% +trouble you see that red X and if I run + + + align:start position:0% +trouble you see that red X and if I run +that code python gives me a syntax eror + + align:start position:0% +that code python gives me a syntax eror + + + align:start position:0% +that code python gives me a syntax eror +this one's pretty easy to debug there's + + align:start position:0% +this one's pretty easy to debug there's + + + align:start position:0% +this one's pretty easy to debug there's +a return outside of a function yep there + + align:start position:0% +a return outside of a function yep there + + + align:start position:0% +a return outside of a function yep there +it is okay so return only has a meaning + + align:start position:0% +it is okay so return only has a meaning + + + align:start position:0% +it is okay so return only has a meaning +inside a function it basically says this + + align:start position:0% +inside a function it basically says this + + + align:start position:0% +inside a function it basically says this +function has done some work for me and + + align:start position:0% +function has done some work for me and + + + align:start position:0% +function has done some work for me and +it's returning back this value print + + align:start position:0% +it's returning back this value print + + + align:start position:0% +it's returning back this value print +statements can be put wherever you'd + + align:start position:0% +statements can be put wherever you'd + + + align:start position:0% +statements can be put wherever you'd +like inside functions outside functions + + align:start position:0% +like inside functions outside functions + + + align:start position:0% +like inside functions outside functions +wherever you'd like and they all get + + align:start position:0% +wherever you'd like and they all get + + + align:start position:0% +wherever you'd like and they all get +executed you can have many return + + align:start position:0% +executed you can have many return + + + align:start position:0% +executed you can have many return +statements inside a function like if you + + align:start position:0% +statements inside a function like if you + + + align:start position:0% +statements inside a function like if you +have a function that returns zero if + + align:start position:0% +have a function that returns zero if + + + align:start position:0% +have a function that returns zero if +some condition applies or one if some + + align:start position:0% +some condition applies or one if some + + + align:start position:0% +some condition applies or one if some +other condition applies then you can + + align:start position:0% +other condition applies then you can + + + align:start position:0% +other condition applies then you can +have those two return statements but as + + align:start position:0% +have those two return statements but as + + + align:start position:0% +have those two return statements but as +soon as python during execution hits one + + align:start position:0% +soon as python during execution hits one + + + align:start position:0% +soon as python during execution hits one +return statement it immediately ends the + + align:start position:0% +return statement it immediately ends the + + + align:start position:0% +return statement it immediately ends the +function takes that return value and + + align:start position:0% +function takes that return value and + + + align:start position:0% +function takes that return value and +Pops it back to whoever called it okay + + align:start position:0% +Pops it back to whoever called it okay + + + align:start position:0% +Pops it back to whoever called it okay +so it's not going to run more than one + + align:start position:0% +so it's not going to run more than one + + + align:start position:0% +so it's not going to run more than one +return uh statement print on the other + + align:start position:0% +return uh statement print on the other + + + align:start position:0% +return uh statement print on the other +hand you can run as many uh print + + align:start position:0% +hand you can run as many uh print + + + align:start position:0% +hand you can run as many uh print +statements as you'd like inside the the + + align:start position:0% +statements as you'd like inside the the + + + align:start position:0% +statements as you'd like inside the the +program right and they can all be hit um + + align:start position:0% +program right and they can all be hit um + + + align:start position:0% +program right and they can all be hit um +and they can all generate some sort of + + align:start position:0% +and they can all generate some sort of + + + align:start position:0% +and they can all generate some sort of +output to the + + align:start position:0% + + + + align:start position:0% + +console + + align:start position:0% +console + + + align:start position:0% +console +um so the return statement has a value + + align:start position:0% +um so the return statement has a value + + + align:start position:0% +um so the return statement has a value +associated with it right so return five + + align:start position:0% +associated with it right so return five + + + align:start position:0% +associated with it right so return five +return you know we had remainder equal + + align:start position:0% +return you know we had remainder equal + + + align:start position:0% +return you know we had remainder equal +equal zero whatever there's the + + align:start position:0% +equal zero whatever there's the + + + align:start position:0% +equal zero whatever there's the +associated value with that return + + align:start position:0% +associated value with that return + + + align:start position:0% +associated value with that return +statement that value is what gets passed + + align:start position:0% +statement that value is what gets passed + + + align:start position:0% +statement that value is what gets passed +back to whoever called the function the + + align:start position:0% +back to whoever called the function the + + + align:start position:0% +back to whoever called the function the +print statement also you can think of it + + align:start position:0% +print statement also you can think of it + + + align:start position:0% +print statement also you can think of it +as having a value associated with it + + align:start position:0% +as having a value associated with it + + + align:start position:0% +as having a value associated with it +that's the thing that gets put out to + + align:start position:0% +that's the thing that gets put out to + + + align:start position:0% +that's the thing that gets put out to +the + + align:start position:0% +the + + + align:start position:0% +the +console but that value associated with + + align:start position:0% +console but that value associated with + + + align:start position:0% +console but that value associated with +the print statement is is just something + + align:start position:0% +the print statement is is just something + + + align:start position:0% +the print statement is is just something +that's outputed to the console it's not + + align:start position:0% +that's outputed to the console it's not + + + align:start position:0% +that's outputed to the console it's not +being passed around through the program + + align:start position:0% +being passed around through the program + + + align:start position:0% +being passed around through the program +at all it's just kind of static it gets + + align:start position:0% +at all it's just kind of static it gets + + + align:start position:0% +at all it's just kind of static it gets +put to the console and then that's it + + align:start position:0% +put to the console and then that's it + + + align:start position:0% +put to the console and then that's it +nobody else can really use that value + + align:start position:0% +nobody else can really use that value + + + align:start position:0% +nobody else can really use that value +you know unless it's a variable and then + + align:start position:0% +you know unless it's a variable and then + + + align:start position:0% +you know unless it's a variable and then +you're just using a a regular + + align:start position:0% +you're just using a a regular + + + align:start position:0% +you're just using a a regular +variable the last thing I want to show + + align:start position:0% +variable the last thing I want to show + + + align:start position:0% +variable the last thing I want to show +you this is kind of cool so if we have a + + align:start position:0% +you this is kind of cool so if we have a + + + align:start position:0% +you this is kind of cool so if we have a +print statement right just in here and + + align:start position:0% +print statement right just in here and + + + align:start position:0% +print statement right just in here and +we run it obviously that prints that to + + align:start position:0% +we run it obviously that prints that to + + + align:start position:0% +we run it obviously that prints that to +the console but what is this + + align:start position:0% +the console but what is this + + + align:start position:0% +the console but what is this +print it's a function right it has all + + align:start position:0% +print it's a function right it has all + + + align:start position:0% +print it's a function right it has all +the tale signs of a function the name is + + align:start position:0% +the tale signs of a function the name is + + + align:start position:0% +the tale signs of a function the name is +print the parentheses are there and I'm + + align:start position:0% +print the parentheses are there and I'm + + + align:start position:0% +print the parentheses are there and I'm +giving it one parameter + + align:start position:0% +giving it one parameter + + + align:start position:0% +giving it one parameter +five right so if I + + align:start position:0% +five right so if I + + + align:start position:0% +five right so if I +print the return of the print function + + align:start position:0% +print the return of the print function + + + align:start position:0% +print the return of the print function +so if I wrap my print function in + + align:start position:0% +so if I wrap my print function in + + + align:start position:0% +so if I wrap my print function in +another print function what do you think + + align:start position:0% +another print function what do you think + + + align:start position:0% +another print function what do you think +this is going to + + align:start position:0% + + + + align:start position:0% + +Output + + align:start position:0% +Output + + + align:start position:0% +Output +I'll run + + align:start position:0% +I'll run + + + align:start position:0% +I'll run +it it outputs none so the first five is + + align:start position:0% +it it outputs none so the first five is + + + align:start position:0% +it it outputs none so the first five is +due to this this shows up on the console + + align:start position:0% +due to this this shows up on the console + + + align:start position:0% +due to this this shows up on the console +but print being a function it doesn't + + align:start position:0% +but print being a function it doesn't + + + align:start position:0% +but print being a function it doesn't +actually return anything right it does + + align:start position:0% +actually return anything right it does + + + align:start position:0% +actually return anything right it does +something useful like take whatever you + + align:start position:0% +something useful like take whatever you + + + align:start position:0% +something useful like take whatever you +want and show it on the console but it + + align:start position:0% +want and show it on the console but it + + + align:start position:0% +want and show it on the console but it +doesn't return anything back to whoever + + align:start position:0% +doesn't return anything back to whoever + + + align:start position:0% +doesn't return anything back to whoever +called it and so if I wrap my print + + align:start position:0% +called it and so if I wrap my print + + + align:start position:0% +called it and so if I wrap my print +function around another print function + + align:start position:0% +function around another print function + + + align:start position:0% +function around another print function +I'm basically printing the return of the + + align:start position:0% +I'm basically printing the return of the + + + align:start position:0% +I'm basically printing the return of the +print function which is none so that's + + align:start position:0% +print function which is none so that's + + + align:start position:0% +print function which is none so that's +where the second none comes + + align:start position:0% +where the second none comes + + + align:start position:0% +where the second none comes +in right so thought of another way you + + align:start position:0% +in right so thought of another way you + + + align:start position:0% +in right so thought of another way you +can make a variable a equals print 5 and + + align:start position:0% +can make a variable a equals print 5 and + + + align:start position:0% +can make a variable a equals print 5 and +if I print a basically we're saying the + + align:start position:0% +if I print a basically we're saying the + + + align:start position:0% +if I print a basically we're saying the +return of that print first print + + align:start position:0% +return of that print first print + + + align:start position:0% +return of that print first print +function is just + + align:start position:0% + + + + align:start position:0% + +none + + align:start position:0% + + + + align:start position:0% + +yeah okay so I'm I'm going to have you + + align:start position:0% +yeah okay so I'm I'm going to have you + + + align:start position:0% +yeah okay so I'm I'm going to have you +work on this code for a little bit uh + + align:start position:0% +work on this code for a little bit uh + + + align:start position:0% +work on this code for a little bit uh +nothing to write but there is something + + align:start position:0% +nothing to write but there is something + + + align:start position:0% +nothing to write but there is something +to fix so here's a function called is + + align:start position:0% +to fix so here's a function called is + + + align:start position:0% +to fix so here's a function called is +triangular it takes in one parameter and + + align:start position:0% +triangular it takes in one parameter and + + + align:start position:0% +triangular it takes in one parameter and +it's a number an integer greater than + + align:start position:0% +it's a number an integer greater than + + + align:start position:0% +it's a number an integer greater than +zero I want this function to return true + + align:start position:0% +zero I want this function to return true + + + align:start position:0% +zero I want this function to return true +if n is triangular and false otherwise + + align:start position:0% +if n is triangular and false otherwise + + + align:start position:0% +if n is triangular and false otherwise +so triangular just means it's a whole + + align:start position:0% +so triangular just means it's a whole + + + align:start position:0% +so triangular just means it's a whole +number uh such that it's equal to 1 plus + + align:start position:0% +number uh such that it's equal to 1 plus + + + align:start position:0% +number uh such that it's equal to 1 plus +2 plus 3 plus some you know some some + + align:start position:0% +2 plus 3 plus some you know some some + + + align:start position:0% +2 plus 3 plus some you know some some +summation like that right so one is + + align:start position:0% +summation like that right so one is + + + align:start position:0% +summation like that right so one is +triangular three is triangular uh six is + + align:start position:0% +triangular three is triangular uh six is + + + align:start position:0% +triangular three is triangular uh six is +triangular and so on and so + + align:start position:0% +triangular and so on and so + + + align:start position:0% +triangular and so on and so +on so take a look at this + + align:start position:0% +on so take a look at this + + + align:start position:0% +on so take a look at this +code um it's on + + align:start position:0% +code um it's on + + + align:start position:0% +code um it's on +line around 49 is so start by running it + + align:start position:0% +line around 49 is so start by running it + + + align:start position:0% +line around 49 is so start by running it +seeing what you get and I'll give you + + align:start position:0% +seeing what you get and I'll give you + + + align:start position:0% +seeing what you get and I'll give you +about a minute or so to see if you can + + align:start position:0% +about a minute or so to see if you can + + + align:start position:0% +about a minute or so to see if you can +try to fix it okay so make sure it runs + + align:start position:0% +try to fix it okay so make sure it runs + + + align:start position:0% +try to fix it okay so make sure it runs +with all these test cases + + align:start position:0% + + + + align:start position:0% + +here okay what's the first thing you + + align:start position:0% +here okay what's the first thing you + + + align:start position:0% +here okay what's the first thing you +should do when you're asked to fix some + + align:start position:0% +should do when you're asked to fix some + + + align:start position:0% +should do when you're asked to fix some +code that's + + align:start position:0% +code that's + + + align:start position:0% +code that's +buggy + + align:start position:0% + + + + align:start position:0% + +yes we can do that but first let's run + + align:start position:0% +yes we can do that but first let's run + + + align:start position:0% +yes we can do that but first let's run +it with something right um so let's run + + align:start position:0% +it with something right um so let's run + + + align:start position:0% +it with something right um so let's run +it with the first one print is + + align:start position:0% +it with the first one print is + + + align:start position:0% +it with the first one print is +triangular 4 so we know the answer + + align:start position:0% +triangular 4 so we know the answer + + + align:start position:0% +triangular 4 so we know the answer +should be false I mean I I told you so + + align:start position:0% +should be false I mean I I told you so + + + align:start position:0% +should be false I mean I I told you so +that it's + + align:start position:0% +that it's + + + align:start position:0% +that it's +good um yes it does give me false which + + align:start position:0% +good um yes it does give me false which + + + align:start position:0% +good um yes it does give me false which +is good but it also prints out a + + align:start position:0% + + + + align:start position:0% + +none what does that mean for + + align:start position:0% +none what does that mean for + + + align:start position:0% +none what does that mean for +us + + align:start position:0% + + + + align:start position:0% + +yes yeah exactly perfect so there's no + + align:start position:0% +yes yeah exactly perfect so there's no + + + align:start position:0% +yes yeah exactly perfect so there's no +actual return statement right like I + + align:start position:0% +actual return statement right like I + + + align:start position:0% +actual return statement right like I +mentioned in with this even example if + + align:start position:0% +mentioned in with this even example if + + + align:start position:0% +mentioned in with this even example if +you're seeing some nuns show up in + + align:start position:0% +you're seeing some nuns show up in + + + align:start position:0% +you're seeing some nuns show up in +places check your returns so is this + + align:start position:0% +places check your returns so is this + + + align:start position:0% +places check your returns so is this +function actually returning something no + + align:start position:0% +function actually returning something no + + + align:start position:0% +function actually returning something no +it's just printing this the result so + + align:start position:0% +it's just printing this the result so + + + align:start position:0% +it's just printing this the result so +it's printing the right thing in this + + align:start position:0% +it's printing the right thing in this + + + align:start position:0% +it's printing the right thing in this +case right so let's start by changing + + align:start position:0% +case right so let's start by changing + + + align:start position:0% +case right so let's start by changing +the prints to + + align:start position:0% +the prints to + + + align:start position:0% +the prints to +returns right yeah says and then + + align:start position:0% +returns right yeah says and then + + + align:start position:0% +returns right yeah says and then +FSE for this one + + align:start position:0% +FSE for this one + + + align:start position:0% +FSE for this one +yeah oh mind I think I + + align:start position:0% +yeah oh mind I think I + + + align:start position:0% +yeah oh mind I think I +just + + align:start position:0% +just + + + align:start position:0% +just +okay all right let's run + + align:start position:0% +okay all right let's run + + + align:start position:0% +okay all right let's run +it perfect yeah so that seems to fixed + + align:start position:0% +it perfect yeah so that seems to fixed + + + align:start position:0% +it perfect yeah so that seems to fixed +it + + align:start position:0% +it + + + align:start position:0% +it +um what should we do + + align:start position:0% + + + + align:start position:0% + +next yes check the rest of the print + + align:start position:0% +next yes check the rest of the print + + + align:start position:0% +next yes check the rest of the print +statements it doesn't work one yes + + align:start position:0% +statements it doesn't work one yes + + + align:start position:0% +statements it doesn't work one yes +exactly let's check the rest of the + + align:start position:0% +exactly let's check the rest of the + + + align:start position:0% +exactly let's check the rest of the +print statements so the second one six + + align:start position:0% +print statements so the second one six + + + align:start position:0% +print statements so the second one six +is triangular so that prints true and + + align:start position:0% +is triangular so that prints true and + + + align:start position:0% +is triangular so that prints true and +last one as you mentioned is going to + + align:start position:0% +last one as you mentioned is going to + + + align:start position:0% +last one as you mentioned is going to +fail on us it prints false but one is + + align:start position:0% +fail on us it prints false but one is + + + align:start position:0% +fail on us it prints false but one is +triangular right because one is just the + + align:start position:0% +triangular right because one is just the + + + align:start position:0% +triangular right because one is just the +sum of one so do you know what a fixed + + align:start position:0% +sum of one so do you know what a fixed + + + align:start position:0% +sum of one so do you know what a fixed +could be the range n plus one yeah + + align:start position:0% +could be the range n plus one yeah + + + align:start position:0% +could be the range n plus one yeah +exactly so you've you've spotted it the + + align:start position:0% +exactly so you've you've spotted it the + + + align:start position:0% +exactly so you've you've spotted it the +range should be n+ one if you didn't + + align:start position:0% +range should be n+ one if you didn't + + + align:start position:0% +range should be n+ one if you didn't +spot that right away um as I think + + align:start position:0% +spot that right away um as I think + + + align:start position:0% +spot that right away um as I think +somebody mentioned there the first thing + + align:start position:0% +somebody mentioned there the first thing + + + align:start position:0% +somebody mentioned there the first thing +we should do is just start putting some + + align:start position:0% +we should do is just start putting some + + + align:start position:0% +we should do is just start putting some +print statements and inside the loop is + + align:start position:0% +print statements and inside the loop is + + + align:start position:0% +print statements and inside the loop is +a great place to put a print statement + + align:start position:0% +a great place to put a print statement + + + align:start position:0% +a great place to put a print statement +we can see what thing we're iterating + + align:start position:0% +we can see what thing we're iterating + + + align:start position:0% +we can see what thing we're iterating +over right and so if this was still n + + align:start position:0% +over right and so if this was still n + + + align:start position:0% +over right and so if this was still n +and we didn't manage to fix it and we + + align:start position:0% +and we didn't manage to fix it and we + + + align:start position:0% +and we didn't manage to fix it and we +run it we see that we've iterated when I + + align:start position:0% +run it we see that we've iterated when I + + + align:start position:0% +run it we see that we've iterated when I +is zero right right here and we never + + align:start position:0% +is zero right right here and we never + + + align:start position:0% +is zero right right here and we never +actually hit hit one right so the fix + + align:start position:0% +actually hit hit one right so the fix + + + align:start position:0% +actually hit hit one right so the fix +for that is make sure we go up to n + + align:start position:0% +for that is make sure we go up to n + + + align:start position:0% +for that is make sure we go up to n +including n and now if we run + + align:start position:0% +including n and now if we run + + + align:start position:0% +including n and now if we run +it and remove this print statement + + align:start position:0% +it and remove this print statement + + + align:start position:0% +it and remove this print statement +because it might be a little + + align:start position:0% +because it might be a little + + + align:start position:0% +because it might be a little +confusing that now gives me the correct + + align:start position:0% +confusing that now gives me the correct + + + align:start position:0% +confusing that now gives me the correct +answer last step should probably be to + + align:start position:0% +answer last step should probably be to + + + align:start position:0% +answer last step should probably be to +run the other two cases again just in + + align:start position:0% +run the other two cases again just in + + + align:start position:0% +run the other two cases again just in +case my fix broke something else and it + + align:start position:0% +case my fix broke something else and it + + + align:start position:0% +case my fix broke something else and it +didn't the other two cases are still the + + align:start position:0% + + + + align:start position:0% + +same questions about this code does it + + align:start position:0% +same questions about this code does it + + + align:start position:0% +same questions about this code does it +make + + align:start position:0% + + + + align:start position:0% + +sense okay so now last lecture I + + align:start position:0% +sense okay so now last lecture I + + + align:start position:0% +sense okay so now last lecture I +mentioned that once we write functions + + align:start position:0% +mentioned that once we write functions + + + align:start position:0% +mentioned that once we write functions +it's really easy to include these + + align:start position:0% +it's really easy to include these + + + align:start position:0% +it's really easy to include these +functions in larger pieces of code and + + align:start position:0% +functions in larger pieces of code and + + + align:start position:0% +functions in larger pieces of code and +it makes those larger pieces of code + + align:start position:0% +it makes those larger pieces of code + + + align:start position:0% +it makes those larger pieces of code +very nicely readable so let's try to do + + align:start position:0% +very nicely readable so let's try to do + + + align:start position:0% +very nicely readable so let's try to do +the same with a slightly more complex + + align:start position:0% +the same with a slightly more complex + + + align:start position:0% +the same with a slightly more complex +example let's try to do uh to create + + align:start position:0% +example let's try to do uh to create + + + align:start position:0% +example let's try to do uh to create +take our bsection root code right and + + align:start position:0% +take our bsection root code right and + + + align:start position:0% +take our bsection root code right and +make it into a function and then there's + + align:start position:0% +make it into a function and then there's + + + align:start position:0% +make it into a function and then there's +going to be an exercise in a couple + + align:start position:0% +going to be an exercise in a couple + + + align:start position:0% +going to be an exercise in a couple +slides where you get to use this uh this + + align:start position:0% +slides where you get to use this uh this + + + align:start position:0% +slides where you get to use this uh this +function so the inside of + + align:start position:0% +function so the inside of + + + align:start position:0% +function so the inside of +this uh function here is basically what + + align:start position:0% +this uh function here is basically what + + + align:start position:0% +this uh function here is basically what +we had like three lectures ago okay it's + + align:start position:0% +we had like three lectures ago okay it's + + + align:start position:0% +we had like three lectures ago okay it's +just the bisection square root code the + + align:start position:0% +just the bisection square root code the + + + align:start position:0% +just the bisection square root code the +only thing I've done is I've wrapped it + + align:start position:0% +only thing I've done is I've wrapped it + + + align:start position:0% +only thing I've done is I've wrapped it +around a function definition so DF I + + align:start position:0% +around a function definition so DF I + + + align:start position:0% +around a function definition so DF I +gave it a name B section root is a + + align:start position:0% +gave it a name B section root is a + + + align:start position:0% +gave it a name B section root is a +pretty nice name and figured out what + + align:start position:0% +pretty nice name and figured out what + + + align:start position:0% +pretty nice name and figured out what +input this function should take so the + + align:start position:0% +input this function should take so the + + + align:start position:0% +input this function should take so the +input should be the X I would like to + + align:start position:0% +input should be the X I would like to + + + align:start position:0% +input should be the X I would like to +approximate the square root of right um + + align:start position:0% +approximate the square root of right um + + + align:start position:0% +approximate the square root of right um +one thing I didn't do is put a dock + + align:start position:0% +one thing I didn't do is put a dock + + + align:start position:0% +one thing I didn't do is put a dock +string on this so that's my bad uh but + + align:start position:0% +string on this so that's my bad uh but + + + align:start position:0% +string on this so that's my bad uh but +you know the doc string would say x is a + + align:start position:0% +you know the doc string would say x is a + + + align:start position:0% +you know the doc string would say x is a +positive integer greater than one and + + align:start position:0% +positive integer greater than one and + + + align:start position:0% +positive integer greater than one and +Returns the approximation to the square + + align:start position:0% +Returns the approximation to the square + + + align:start position:0% +Returns the approximation to the square +root of x or something like + + align:start position:0% +root of x or something like + + + align:start position:0% +root of x or something like +that um okay so here we're hard coding + + align:start position:0% +that um okay so here we're hard coding + + + align:start position:0% +that um okay so here we're hard coding +Epsilon to + + align:start position:0% +Epsilon to + + + align:start position:0% +Epsilon to +be1 uh we've got our low and high end + + align:start position:0% +be1 uh we've got our low and high end + + + align:start position:0% +be1 uh we've got our low and high end +points right just remembering what the + + align:start position:0% +points right just remembering what the + + + align:start position:0% +points right just remembering what the +bisection route does and we're starting + + align:start position:0% +bisection route does and we're starting + + + align:start position:0% +bisection route does and we're starting +out with a guess that's right in between + + align:start position:0% +out with a guess that's right in between + + + align:start position:0% +out with a guess that's right in between +the low and + + align:start position:0% +the low and + + + align:start position:0% +the low and +high the while loop here is going to do + + align:start position:0% +high the while loop here is going to do + + + align:start position:0% +high the while loop here is going to do +the work for us so the while loop + + align:start position:0% +the work for us so the while loop + + + align:start position:0% +the work for us so the while loop +condition is while the difference the + + align:start position:0% +condition is while the difference the + + + align:start position:0% +condition is while the difference the +absolute Val value right the difference + + align:start position:0% +absolute Val value right the difference + + + align:start position:0% +absolute Val value right the difference +between our guest squared and the actual + + align:start position:0% +between our guest squared and the actual + + + align:start position:0% +between our guest squared and the actual +X we're trying to find the square root + + align:start position:0% +X we're trying to find the square root + + + align:start position:0% +X we're trying to find the square root +of is bigger than Epsilon so while we're + + align:start position:0% +of is bigger than Epsilon so while we're + + + align:start position:0% +of is bigger than Epsilon so while we're +still farther away than Epsilon we have + + align:start position:0% +still farther away than Epsilon we have + + + align:start position:0% +still farther away than Epsilon we have +more guesses to make the way we make the + + align:start position:0% +more guesses to make the way we make the + + + align:start position:0% +more guesses to make the way we make the +guesses is by updating the lowend point + + align:start position:0% +guesses is by updating the lowend point + + + align:start position:0% +guesses is by updating the lowend point +or the high end point right depending on + + align:start position:0% +or the high end point right depending on + + + align:start position:0% +or the high end point right depending on +whether our guess was too low or too + + align:start position:0% +whether our guess was too low or too + + + align:start position:0% +whether our guess was too low or too +high this should be review hopefully and + + align:start position:0% +high this should be review hopefully and + + + align:start position:0% +high this should be review hopefully and +then after we've decided on which end + + align:start position:0% +then after we've decided on which end + + + align:start position:0% +then after we've decided on which end +point to update we update our new guess + + align:start position:0% +point to update we update our new guess + + + align:start position:0% +point to update we update our new guess +to be whatever High plus low is divid by + + align:start position:0% +to be whatever High plus low is divid by + + + align:start position:0% +to be whatever High plus low is divid by +two again so the midpoint of those where + + align:start position:0% +two again so the midpoint of those where + + + align:start position:0% +two again so the midpoint of those where +either high or low would have just + + align:start position:0% +either high or low would have just + + + align:start position:0% +either high or low would have just +changed right because of this if else + + align:start position:0% +changed right because of this if else + + + align:start position:0% +changed right because of this if else +and this Loop will just keep going over + + align:start position:0% +and this Loop will just keep going over + + + align:start position:0% +and this Loop will just keep going over +and over and over again making better + + align:start position:0% +and over and over again making better + + + align:start position:0% +and over and over again making better +and better approximations until we come + + align:start position:0% +and better approximations until we come + + + align:start position:0% +and better approximations until we come +within plus or minus Epsilon of uh the + + align:start position:0% +within plus or minus Epsilon of uh the + + + align:start position:0% +within plus or minus Epsilon of uh the +square Ro of + + align:start position:0% +square Ro of + + + align:start position:0% +square Ro of +X of + + align:start position:0% +X of + + + align:start position:0% +X of +X the difference between this code and + + align:start position:0% +X the difference between this code and + + + align:start position:0% +X the difference between this code and +what we wrote a few a few lectures ago + + align:start position:0% +what we wrote a few a few lectures ago + + + align:start position:0% +what we wrote a few a few lectures ago +is this uh part down here so a few + + align:start position:0% +is this uh part down here so a few + + + align:start position:0% +is this uh part down here so a few +lectures ago we all all we could do + + align:start position:0% +lectures ago we all all we could do + + + align:start position:0% +lectures ago we all all we could do +really was uh write a print statement + + align:start position:0% +really was uh write a print statement + + + align:start position:0% +really was uh write a print statement +where we took our guess that we ended up + + align:start position:0% +where we took our guess that we ended up + + + align:start position:0% +where we took our guess that we ended up +with right and we printed it along with + + align:start position:0% +with right and we printed it along with + + + align:start position:0% +with right and we printed it along with +you know that guess is close to the root + + align:start position:0% +you know that guess is close to the root + + + align:start position:0% +you know that guess is close to the root +of our original + + align:start position:0% +of our original + + + align:start position:0% +of our original +X but instead since we're writing a + + align:start position:0% +X but instead since we're writing a + + + align:start position:0% +X but instead since we're writing a +function I would like to take the result + + align:start position:0% +function I would like to take the result + + + align:start position:0% +function I would like to take the result +right my approximation to X and return + + align:start position:0% +right my approximation to X and return + + + align:start position:0% +right my approximation to X and return +it so somebody can call this function + + align:start position:0% +it so somebody can call this function + + + align:start position:0% +it so somebody can call this function +many many many times with different + + align:start position:0% +many many many times with different + + + align:start position:0% +many many many times with different +values of X and figure out a bunch of + + align:start position:0% +values of X and figure out a bunch of + + + align:start position:0% +values of X and figure out a bunch of +different approximations for all of + + align:start position:0% +different approximations for all of + + + align:start position:0% +different approximations for all of +these different X's okay so here I have + + align:start position:0% +these different X's okay so here I have + + + align:start position:0% +these different X's okay so here I have +the function calls right so I've got + + align:start position:0% +the function calls right so I've got + + + align:start position:0% +the function calls right so I've got +bsection root with four and bisection + + align:start position:0% +bsection root with four and bisection + + + align:start position:0% +bsection root with four and bisection +root with 123 and then I can just print + + align:start position:0% +root with 123 and then I can just print + + + align:start position:0% +root with 123 and then I can just print +the results of these right so here is + + align:start position:0% +the results of these right so here is + + + align:start position:0% +the results of these right so here is +the bisection root + + align:start position:0% +the bisection root + + + align:start position:0% +the bisection root +function I've got my print out uh + + align:start position:0% +function I've got my print out uh + + + align:start position:0% +function I've got my print out uh +commented out because I don't actually + + align:start position:0% +commented out because I don't actually + + + align:start position:0% +commented out because I don't actually +need it uh the rest of the code will do + + align:start position:0% +need it uh the rest of the code will do + + + align:start position:0% +need it uh the rest of the code will do +something useful with the approximations + + align:start position:0% +something useful with the approximations + + + align:start position:0% +something useful with the approximations +right so in this case bis section root + + align:start position:0% +right so in this case bis section root + + + align:start position:0% +right so in this case bis section root +of four was uh gave me a 2.0 so that's + + align:start position:0% +of four was uh gave me a 2.0 so that's + + + align:start position:0% +of four was uh gave me a 2.0 so that's +the approximation and the bisection root + + align:start position:0% +the approximation and the bisection root + + + align:start position:0% +the approximation and the bisection root +of + + align:start position:0% +of + + + align:start position:0% +of +123 uh was approximated to + + align:start position:0% + + + + align:start position:0% + +11.09 + + align:start position:0% + + + + align:start position:0% + +okay so what I would like you to do and + + align:start position:0% +okay so what I would like you to do and + + + align:start position:0% +okay so what I would like you to do and +this is going to be a little bit + + align:start position:0% +this is going to be a little bit + + + align:start position:0% +this is going to be a little bit +involved code it'll require some + + align:start position:0% +involved code it'll require some + + + align:start position:0% +involved code it'll require some +thinking is to write a function called + + align:start position:0% +thinking is to write a function called + + + align:start position:0% +thinking is to write a function called +count the numbers with the square root + + align:start position:0% +count the numbers with the square root + + + align:start position:0% +count the numbers with the square root +close + + align:start position:0% +close + + + align:start position:0% +close +to N plus or minus Epsilon okay + + align:start position:0% +to N plus or minus Epsilon okay + + + align:start position:0% +to N plus or minus Epsilon okay +and I'll I'll I'll help you out by + + align:start position:0% +and I'll I'll I'll help you out by + + + align:start position:0% +and I'll I'll I'll help you out by +drawing something on the board but I + + align:start position:0% +drawing something on the board but I + + + align:start position:0% +drawing something on the board but I +would like you to do uh the code for it + + align:start position:0% +would like you to do uh the code for it + + + align:start position:0% +would like you to do uh the code for it +so the idea here is that you have some n + + align:start position:0% +so the idea here is that you have some n + + + align:start position:0% +so the idea here is that you have some n +that's given as an input and you have an + + align:start position:0% +that's given as an input and you have an + + + align:start position:0% +that's given as an input and you have an +Epsilon that's also given as an input + + align:start position:0% +Epsilon that's also given as an input + + + align:start position:0% +Epsilon that's also given as an input +what you'd like to find out is how many + + align:start position:0% +what you'd like to find out is how many + + + align:start position:0% +what you'd like to find out is how many +whole numbers have their square root + + align:start position:0% +whole numbers have their square root + + + align:start position:0% +whole numbers have their square root +within plus or minus Epsilon of + + align:start position:0% +within plus or minus Epsilon of + + + align:start position:0% +within plus or minus Epsilon of +n so this is is kind of hard to wrap + + align:start position:0% +n so this is is kind of hard to wrap + + + align:start position:0% +n so this is is kind of hard to wrap +your mind around without actually + + align:start position:0% +your mind around without actually + + + align:start position:0% +your mind around without actually +drawing a picture so this is also + + align:start position:0% +drawing a picture so this is also + + + align:start position:0% +drawing a picture so this is also +something you should try to do in quiz + + align:start position:0% +something you should try to do in quiz + + + align:start position:0% +something you should try to do in quiz +situations pets things like that don't + + align:start position:0% +situations pets things like that don't + + + align:start position:0% +situations pets things like that don't +code right away try to draw a picture + + align:start position:0% +code right away try to draw a picture + + + align:start position:0% +code right away try to draw a picture +kind of depicting what we're asking for + + align:start position:0% +kind of depicting what we're asking for + + + align:start position:0% +kind of depicting what we're asking for +here so here we'll start with a line + + align:start position:0% +here so here we'll start with a line + + + align:start position:0% +here so here we'll start with a line +right this is our number line because + + align:start position:0% +right this is our number line because + + + align:start position:0% +right this is our number line because +we're doing the square + + align:start position:0% + + + + align:start position:0% + +root we want to know how many integers + + align:start position:0% +root we want to know how many integers + + + align:start position:0% +root we want to know how many integers +have a square root with an Epsilon of n + + align:start position:0% +have a square root with an Epsilon of n + + + align:start position:0% +have a square root with an Epsilon of n +so let's start with an + + align:start position:0% +so let's start with an + + + align:start position:0% +so let's start with an +N + + align:start position:0% +N + + + align:start position:0% +N +right and we have something plus or + + align:start position:0% +right and we have something plus or + + + align:start position:0% +right and we have something plus or +minus Epsilon right so this is + + align:start position:0% +minus Epsilon right so this is + + + align:start position:0% +minus Epsilon right so this is +Epsilon and this is also Epsilon + + align:start position:0% +Epsilon and this is also Epsilon + + + align:start position:0% +Epsilon and this is also Epsilon +right in the end we want to know how + + align:start position:0% +right in the end we want to know how + + + align:start position:0% +right in the end we want to know how +many integers have a square + + align:start position:0% +many integers have a square + + + align:start position:0% +many integers have a square +root square root of I so actually I'll + + align:start position:0% +root square root of I so actually I'll + + + align:start position:0% +root square root of I so actually I'll +do it like this square root of + + align:start position:0% +do it like this square root of + + + align:start position:0% +do it like this square root of +I is equal to somewhere in this + + align:start position:0% +I is equal to somewhere in this + + + align:start position:0% +I is equal to somewhere in this +range does that make sense so far that's + + align:start position:0% +range does that make sense so far that's + + + align:start position:0% +range does that make sense so far that's +what we're trying to figure out the + + align:start position:0% +what we're trying to figure out the + + + align:start position:0% +what we're trying to figure out the +square root of I is somewhere in this + + align:start position:0% +square root of I is somewhere in this + + + align:start position:0% +square root of I is somewhere in this +range so that means + + align:start position:0% +range so that means + + + align:start position:0% +range so that means +I is going to be some giant number out + + align:start position:0% +I is going to be some giant number out + + + align:start position:0% +I is going to be some giant number out +here right so this line can go further + + align:start position:0% + + + + align:start position:0% + +out so in the example here I've got n is + + align:start position:0% +out so in the example here I've got n is + + + align:start position:0% +out so in the example here I've got n is +equal to + + align:start position:0% + + + + align:start position:0% + +10 so I know for sure that an i of 100 + + align:start position:0% +10 so I know for sure that an i of 100 + + + align:start position:0% +10 so I know for sure that an i of 100 +just kind of us as humans would work + + align:start position:0% +just kind of us as humans would work + + + align:start position:0% +just kind of us as humans would work +right because the square root of 100 is + + align:start position:0% +right because the square root of 100 is + + + align:start position:0% +right because the square root of 100 is +probably going to be approximated to + + align:start position:0% +probably going to be approximated to + + + align:start position:0% +probably going to be approximated to +pretty darn close to to 10 so I know + + align:start position:0% +pretty darn close to to 10 so I know + + + align:start position:0% +pretty darn close to to 10 so I know +that that value will be within plus or + + align:start position:0% +that that value will be within plus or + + + align:start position:0% +that that value will be within plus or +minus Epsilon of 10 but there's probably + + align:start position:0% +minus Epsilon of 10 but there's probably + + + align:start position:0% +minus Epsilon of 10 but there's probably +a couple numbers around 100 that also + + align:start position:0% +a couple numbers around 100 that also + + + align:start position:0% +a couple numbers around 100 that also +match this criteria right if I take the + + align:start position:0% +match this criteria right if I take the + + + align:start position:0% +match this criteria right if I take the +square root of 99 according to this + + align:start position:0% +square root of 99 according to this + + + align:start position:0% +square root of 99 according to this +example that approximation puts me + + align:start position:0% +example that approximation puts me + + + align:start position:0% +example that approximation puts me +within plus or minus Epsilon of 10 right + + align:start position:0% +within plus or minus Epsilon of 10 right + + + align:start position:0% +within plus or minus Epsilon of 10 right +so it's going to be uh you know Square + + align:start position:0% +so it's going to be uh you know Square + + + align:start position:0% +so it's going to be uh you know Square +of 99 is going to be like 9 whatever is + + align:start position:0% +of 99 is going to be like 9 whatever is + + + align:start position:0% +of 99 is going to be like 9 whatever is +here + + align:start position:0% +here + + + align:start position:0% +here +95 right so that's within plus or minus + + align:start position:0% +95 right so that's within plus or minus + + + align:start position:0% +95 right so that's within plus or minus +Epsilon and similarly right square root + + align:start position:0% +Epsilon and similarly right square root + + + align:start position:0% +Epsilon and similarly right square root +of 101 and 102 also work because if I + + align:start position:0% +of 101 and 102 also work because if I + + + align:start position:0% +of 101 and 102 also work because if I +take the square root of these guys that + + align:start position:0% +take the square root of these guys that + + + align:start position:0% +take the square root of these guys that +will also put me within plus or minus + + align:start position:0% +will also put me within plus or minus + + + align:start position:0% +will also put me within plus or minus +Epsilon of + + align:start position:0% +Epsilon of + + + align:start position:0% +Epsilon of +10 so the goal here is basically to + + align:start position:0% +10 so the goal here is basically to + + + align:start position:0% +10 so the goal here is basically to +figure out these numbers 99 100 1001 and + + align:start position:0% +figure out these numbers 99 100 1001 and + + + align:start position:0% +figure out these numbers 99 100 1001 and +1002 you should use the power of + + align:start position:0% +1002 you should use the power of + + + align:start position:0% +1002 you should use the power of +computation and computerss being able to + + align:start position:0% +computation and computerss being able to + + + align:start position:0% +computation and computerss being able to +do a a task really really quickly to + + align:start position:0% +do a a task really really quickly to + + + align:start position:0% +do a a task really really quickly to +basically say I'm just going to brute + + align:start position:0% +basically say I'm just going to brute + + + align:start position:0% +basically say I'm just going to brute +force my way through this problem and + + align:start position:0% +force my way through this problem and + + + align:start position:0% +force my way through this problem and +say I'm going to test each + + align:start position:0% +say I'm going to test each + + + align:start position:0% +say I'm going to test each +number one at a + + align:start position:0% + + + + align:start position:0% + +time all the way up to some pretty large + + align:start position:0% +time all the way up to some pretty large + + + align:start position:0% +time all the way up to some pretty large +number right so you want to make sure + + align:start position:0% +number right so you want to make sure + + + align:start position:0% +number right so you want to make sure +you hit 99 100 101 102 maybe going up to + + align:start position:0% +you hit 99 100 101 102 maybe going up to + + + align:start position:0% +you hit 99 100 101 102 maybe going up to +maybe n cubed right if you go and take + + align:start position:0% +maybe n cubed right if you go and take + + + align:start position:0% +maybe n cubed right if you go and take +the square root of some I cubed you know + + align:start position:0% +the square root of some I cubed you know + + + align:start position:0% +the square root of some I cubed you know +you're going to hit all these values + + align:start position:0% +you're going to hit all these values + + + align:start position:0% +you're going to hit all these values +within plus or minus Epsilon so you're + + align:start position:0% +within plus or minus Epsilon so you're + + + align:start position:0% +within plus or minus Epsilon so you're +just going to Brute Force look at all + + align:start position:0% +just going to Brute Force look at all + + + align:start position:0% +just going to Brute Force look at all +the integers between 0o and N + + align:start position:0% +the integers between 0o and N + + + align:start position:0% +the integers between 0o and N +cubed and figure out if this appro if + + align:start position:0% +cubed and figure out if this appro if + + + align:start position:0% +cubed and figure out if this appro if +their square root the approximation to + + align:start position:0% +their square root the approximation to + + + align:start position:0% +their square root the approximation to +this square root is plus or minus + + align:start position:0% +this square root is plus or minus + + + align:start position:0% +this square root is plus or minus +Epsilon of n if it is keep a counter and + + align:start position:0% +Epsilon of n if it is keep a counter and + + + align:start position:0% +Epsilon of n if it is keep a counter and +increment it and if it's not ignore + + align:start position:0% +increment it and if it's not ignore + + + align:start position:0% +increment it and if it's not ignore +it and that's the idea to this um to + + align:start position:0% +it and that's the idea to this um to + + + align:start position:0% +it and that's the idea to this um to +this + + align:start position:0% +this + + + align:start position:0% +this +question + + align:start position:0% +question + + + align:start position:0% +question +Loop and a check that's + + align:start position:0% +Loop and a check that's + + + align:start position:0% +Loop and a check that's +it and you can definitely feel free to + + align:start position:0% +it and you can definitely feel free to + + + align:start position:0% +it and you can definitely feel free to +make use of the bisection root function + + align:start position:0% +make use of the bisection root function + + + align:start position:0% +make use of the bisection root function +that we wrote uh in in our code right + + align:start position:0% +that we wrote uh in in our code right + + + align:start position:0% +that we wrote uh in in our code right +you should definitely use it because + + align:start position:0% +you should definitely use it because + + + align:start position:0% +you should definitely use it because +it's very + + align:start position:0% +it's very + + + align:start position:0% +it's very +helpful so around line 96 is where you + + align:start position:0% +helpful so around line 96 is where you + + + align:start position:0% +helpful so around line 96 is where you +can write your + + align:start position:0% + + + + align:start position:0% + +code all right does anyone have a start + + align:start position:0% +code all right does anyone have a start + + + align:start position:0% +code all right does anyone have a start +for this uh for writing this code or how + + align:start position:0% +for this uh for writing this code or how + + + align:start position:0% +for this uh for writing this code or how +would you think about it or + + align:start position:0% + + + + align:start position:0% + +yes for I + + align:start position:0% +yes for I + + + align:start position:0% +yes for I +in + + align:start position:0% +in + + + align:start position:0% +in +range uh n cubed yeah we can do that all + + align:start position:0% +range uh n cubed yeah we can do that all + + + align:start position:0% +range uh n cubed yeah we can do that all +right so this will give me numbers zero + + align:start position:0% +right so this will give me numbers zero + + + align:start position:0% +right so this will give me numbers zero +through n + + align:start position:0% +through n + + + align:start position:0% +through n +cubed perfect so I've generated + + align:start position:0% +cubed perfect so I've generated + + + align:start position:0% +cubed perfect so I've generated +basically this sequence now what do I + + align:start position:0% +basically this sequence now what do I + + + align:start position:0% +basically this sequence now what do I +want to do once I have I and you know + + align:start position:0% +want to do once I have I and you know + + + align:start position:0% +want to do once I have I and you know +you can always write a little comment + + align:start position:0% +you can always write a little comment + + + align:start position:0% +you can always write a little comment +for yourself what you want to do once + + align:start position:0% +for yourself what you want to do once + + + align:start position:0% +for yourself what you want to do once +you have I right so in English what + + align:start position:0% +you have I right so in English what + + + align:start position:0% +you have I right so in English what +would you want to do once you have a + + align:start position:0% +would you want to do once you have a + + + align:start position:0% +would you want to do once you have a +number like + + align:start position:0% + + + + align:start position:0% + +this take the square root yeah take the + + align:start position:0% +this take the square root yeah take the + + + align:start position:0% +this take the square root yeah take the +square root of I okay how do you want to + + align:start position:0% +square root of I okay how do you want to + + + align:start position:0% +square root of I okay how do you want to +take the square root of + + align:start position:0% + + + + align:start position:0% + +I we can shall we use our bisection + + align:start position:0% +I we can shall we use our bisection + + + align:start position:0% +I we can shall we use our bisection +route we can + + align:start position:0% + + + + align:start position:0% + +too yep we can do both so let's use the + + align:start position:0% +too yep we can do both so let's use the + + + align:start position:0% +too yep we can do both so let's use the +function we just wrote so B section root + + align:start position:0% +function we just wrote so B section root + + + align:start position:0% +function we just wrote so B section root +of I this gives me square + + align:start position:0% +of I this gives me square + + + align:start position:0% +of I this gives me square +root so now + + align:start position:0% +root so now + + + align:start position:0% +root so now +sqrt is going to be some value here + + align:start position:0% +sqrt is going to be some value here + + + align:start position:0% +sqrt is going to be some value here +right it could be 10 it could be + + align:start position:0% +right it could be 10 it could be + + + align:start position:0% +right it could be 10 it could be +99.5 it could be + + align:start position:0% +99.5 it could be + + + align:start position:0% +99.5 it could be +99.7 what do I do with this number + + align:start position:0% +99.7 what do I do with this number + + + align:start position:0% +99.7 what do I do with this number +now + + align:start position:0% + + + + align:start position:0% + +yes yes exactly let's use an if + + align:start position:0% +yes yes exactly let's use an if + + + align:start position:0% +yes yes exactly let's use an if +statement so if and there's many ways we + + align:start position:0% +statement so if and there's many ways we + + + align:start position:0% +statement so if and there's many ways we +can uh if use the F statement we could + + align:start position:0% +can uh if use the F statement we could + + + align:start position:0% +can uh if use the F statement we could +do absolute value right that's what + + align:start position:0% +do absolute value right that's what + + + align:start position:0% +do absolute value right that's what +we've been doing already so if we take + + align:start position:0% +we've been doing already so if we take + + + align:start position:0% +we've been doing already so if we take +um n minus the square root right so n + + align:start position:0% +um n minus the square root right so n + + + align:start position:0% +um n minus the square root right so n +minus this value we just + + align:start position:0% +minus this value we just + + + align:start position:0% +minus this value we just +calculated is less than + + align:start position:0% +calculated is less than + + + align:start position:0% +calculated is less than +Epsilon all right so here we know + + align:start position:0% + + + + align:start position:0% + +that um square root is within + + align:start position:0% +that um square root is within + + + align:start position:0% +that um square root is within +Epsilon and what do we want to do once + + align:start position:0% +Epsilon and what do we want to do once + + + align:start position:0% +Epsilon and what do we want to do once +we know that the square root is with an + + align:start position:0% + + + + align:start position:0% + +Epsilon + + align:start position:0% +Epsilon + + + align:start position:0% +Epsilon +well if we don't know we can look at the + + align:start position:0% +well if we don't know we can look at the + + + align:start position:0% +well if we don't know we can look at the +doc string so we need to return how many + + align:start position:0% +doc string so we need to return how many + + + align:start position:0% +doc string so we need to return how many +integers have that square root with an + + align:start position:0% +integers have that square root with an + + + align:start position:0% +integers have that square root with an +Epsilon of + + align:start position:0% +Epsilon of + + + align:start position:0% +Epsilon of +n yeah exactly keep count of it right so + + align:start position:0% +n yeah exactly keep count of it right so + + + align:start position:0% +n yeah exactly keep count of it right so +count plus equals + + align:start position:0% + + + + align:start position:0% + +1 yes and I do have to initialize count + + align:start position:0% +1 yes and I do have to initialize count + + + align:start position:0% +1 yes and I do have to initialize count +count equals zero right before + + align:start position:0% +count equals zero right before + + + align:start position:0% +count equals zero right before +my + + align:start position:0% +my + + + align:start position:0% +my +okay anything + + align:start position:0% +okay anything + + + align:start position:0% +okay anything +else + + align:start position:0% + + + + align:start position:0% + +yeah we do need to return so at the end + + align:start position:0% +yeah we do need to return so at the end + + + align:start position:0% +yeah we do need to return so at the end +of the loop we can return our + + align:start position:0% + + + + align:start position:0% + +count okay run + + align:start position:0% +count okay run + + + align:start position:0% +count okay run +it uh what is this from oh this is from + + align:start position:0% +it uh what is this from oh this is from + + + align:start position:0% +it uh what is this from oh this is from +the other two lines + + align:start position:0% +the other two lines + + + align:start position:0% +the other two lines +here so four I think that works because + + align:start position:0% +here so four I think that works because + + + align:start position:0% +here so four I think that works because +from the example there were four numbers + + align:start position:0% +from the example there were four numbers + + + align:start position:0% +from the example there were four numbers +that worked to double check we can or if + + align:start position:0% +that worked to double check we can or if + + + align:start position:0% +that worked to double check we can or if +you know something went wrong and the + + align:start position:0% +you know something went wrong and the + + + align:start position:0% +you know something went wrong and the +number you got wasn't what you were + + align:start position:0% +number you got wasn't what you were + + + align:start position:0% +number you got wasn't what you were +expecting again print statements very + + align:start position:0% +expecting again print statements very + + + align:start position:0% +expecting again print statements very +useful so we could print the value of I + + align:start position:0% +useful so we could print the value of I + + + align:start position:0% +useful so we could print the value of I +so this thing here we're trying to find + + align:start position:0% +so this thing here we're trying to find + + + align:start position:0% +so this thing here we're trying to find +the square root of and we can print the + + align:start position:0% +the square root of and we can print the + + + align:start position:0% +the square root of and we can print the +square root of that value right and so + + align:start position:0% +square root of that value right and so + + + align:start position:0% +square root of that value right and so +if we actually add it to the print State + + align:start position:0% +if we actually add it to the print State + + + align:start position:0% +if we actually add it to the print State +uh to the the code here we see the four + + align:start position:0% +uh to the the code here we see the four + + + align:start position:0% +uh to the the code here we see the four +values that we grabbed 99 100 1001 and + + align:start position:0% +values that we grabbed 99 100 1001 and + + + align:start position:0% +values that we grabbed 99 100 1001 and +1002 and now that we wrote this code we + + align:start position:0% +1002 and now that we wrote this code we + + + align:start position:0% +1002 and now that we wrote this code we +can actually make really um simple + + align:start position:0% +can actually make really um simple + + + align:start position:0% +can actually make really um simple +changes to it and we have some pretty + + align:start position:0% +changes to it and we have some pretty + + + align:start position:0% +changes to it and we have some pretty +useful code right so if we make our + + align:start position:0% +useful code right so if we make our + + + align:start position:0% +useful code right so if we make our +boundary bigger 10 plus or minus one + + align:start position:0% +boundary bigger 10 plus or minus one + + + align:start position:0% +boundary bigger 10 plus or minus one +we're going to get more values that + + align:start position:0% +we're going to get more values that + + + align:start position:0% +we're going to get more values that +match this criteria right so in fact we + + align:start position:0% +match this criteria right so in fact we + + + align:start position:0% +match this criteria right so in fact we +got 40 of them right all the way from uh + + align:start position:0% +got 40 of them right all the way from uh + + + align:start position:0% +got 40 of them right all the way from uh +81 all the way up to 120 they all match + + align:start position:0% +81 all the way up to 120 they all match + + + align:start position:0% +81 all the way up to 120 they all match +the criteria which is when you take the + + align:start position:0% +the criteria which is when you take the + + + align:start position:0% +the criteria which is when you take the +square root of that value it's plus or + + align:start position:0% +square root of that value it's plus or + + + align:start position:0% +square root of that value it's plus or +minus + + align:start position:0% +minus + + + align:start position:0% +minus +uh uh 10 uh 9 to + + align:start position:0% + + + + align:start position:0% + +yeah any questions about this example I + + align:start position:0% +yeah any questions about this example I + + + align:start position:0% +yeah any questions about this example I +know it's kind of involved but I hope + + align:start position:0% +know it's kind of involved but I hope + + + align:start position:0% +know it's kind of involved but I hope +that actually drawing a picture helped + + align:start position:0% +that actually drawing a picture helped + + + align:start position:0% +that actually drawing a picture helped +explain what we were trying to get at + + align:start position:0% +explain what we were trying to get at + + + align:start position:0% +explain what we were trying to get at +and then at that point it should have + + align:start position:0% +and then at that point it should have + + + align:start position:0% +and then at that point it should have +been pretty easy to figure out the + + align:start position:0% +been pretty easy to figure out the + + + align:start position:0% +been pretty easy to figure out the +structure of the code itself any + + align:start position:0% +structure of the code itself any + + + align:start position:0% +structure of the code itself any +questions yes question regarding the r + + align:start position:0% +questions yes question regarding the r + + + align:start position:0% +questions yes question regarding the r +why does it + + align:start position:0% +why does it + + + align:start position:0% +why does it +to like that large a number like it + + align:start position:0% +to like that large a number like it + + + align:start position:0% +to like that large a number like it +could it would be it could be smaller + + align:start position:0% +could it would be it could be smaller + + + align:start position:0% +could it would be it could be smaller +yeah I mean it we could have done n n n + + align:start position:0% +yeah I mean it we could have done n n n + + + align:start position:0% +yeah I mean it we could have done n n n +to the^ 4 we just couldn't do n s + + align:start position:0% +to the^ 4 we just couldn't do n s + + + align:start position:0% +to the^ 4 we just couldn't do n s +because then we might miss we well we + + align:start position:0% +because then we might miss we well we + + + align:start position:0% +because then we might miss we well we +would definitely miss1 and2 in that + + align:start position:0% +would definitely miss1 and2 in that + + + align:start position:0% +would definitely miss1 and2 in that +particular example and in fact if our + + align:start position:0% +particular example and in fact if our + + + align:start position:0% +particular example and in fact if our +Epsilon is really + + align:start position:0% +Epsilon is really + + + align:start position:0% +Epsilon is really +big we might actually I'm not sure about + + align:start position:0% +big we might actually I'm not sure about + + + align:start position:0% +big we might actually I'm not sure about +the math but if our epsilon's really big + + align:start position:0% +the math but if our epsilon's really big + + + align:start position:0% +the math but if our epsilon's really big +we might actually need to go bigger than + + align:start position:0% +we might actually need to go bigger than + + + align:start position:0% +we might actually need to go bigger than +n cubed as well I'd have to think about + + align:start position:0% +n cubed as well I'd have to think about + + + align:start position:0% +n cubed as well I'd have to think about +that but we just it it's okay I I mean + + align:start position:0% +that but we just it it's okay I I mean + + + align:start position:0% +that but we just it it's okay I I mean +it's fine to make it big it doesn't take + + align:start position:0% +it's fine to make it big it doesn't take + + + align:start position:0% +it's fine to make it big it doesn't take +that much longer to compute because the + + align:start position:0% +that much longer to compute because the + + + align:start position:0% +that much longer to compute because the +you know running the function is is very + + align:start position:0% +you know running the function is is very + + + align:start position:0% +you know running the function is is very +quick to python anyway + + align:start position:0% +quick to python anyway + + + align:start position:0% +quick to python anyway +yeah uh yeah there's a question yeah I + + align:start position:0% +yeah uh yeah there's a question yeah I + + + align:start position:0% +yeah uh yeah there's a question yeah I +had a similar question so is there the + + align:start position:0% +had a similar question so is there the + + + align:start position:0% +had a similar question so is there the +reason why we chose n cube is like an + + align:start position:0% +reason why we chose n cube is like an + + + align:start position:0% +reason why we chose n cube is like an +arbitrary number that's big enough yeah + + align:start position:0% +arbitrary number that's big enough yeah + + + align:start position:0% +arbitrary number that's big enough yeah +arbitrary number that's big enough um + + align:start position:0% +arbitrary number that's big enough um + + + align:start position:0% +arbitrary number that's big enough um +what we could have also done just along + + align:start position:0% +what we could have also done just along + + + align:start position:0% +what we could have also done just along +those lines is we could have done a + + align:start position:0% +those lines is we could have done a + + + align:start position:0% +those lines is we could have done a +little something a little bit smarter in + + align:start position:0% +little something a little bit smarter in + + + align:start position:0% +little something a little bit smarter in +here where once we find this uh a number + + align:start position:0% +here where once we find this uh a number + + + align:start position:0% +here where once we find this uh a number +that actually works like once we start + + align:start position:0% +that actually works like once we start + + + align:start position:0% +that actually works like once we start +incrementing our count we could have + + align:start position:0% +incrementing our count we could have + + + align:start position:0% +incrementing our count we could have +some sort of flag that keeps track of as + + align:start position:0% +some sort of flag that keeps track of as + + + align:start position:0% +some sort of flag that keeps track of as +long as we're incrementing the count + + align:start position:0% +long as we're incrementing the count + + + align:start position:0% +long as we're incrementing the count +right keep going but at some point you + + align:start position:0% +right keep going but at some point you + + + align:start position:0% +right keep going but at some point you +know you're going to reach a number + + align:start position:0% +know you're going to reach a number + + + align:start position:0% +know you're going to reach a number +that's too big and at that point you can + + align:start position:0% +that's too big and at that point you can + + + align:start position:0% +that's too big and at that point you can +just end the function early right you + + align:start position:0% +just end the function early right you + + + align:start position:0% +just end the function early right you +can just break out of the loop and you + + align:start position:0% +can just break out of the loop and you + + + align:start position:0% +can just break out of the loop and you +don't need to keep looking at you know + + align:start position:0% +don't need to keep looking at you know + + + align:start position:0% +don't need to keep looking at you know +uh all the way up to n cubed so we could + + align:start position:0% +uh all the way up to n cubed so we could + + + align:start position:0% +uh all the way up to n cubed so we could +have done something a little bit smarter + + align:start position:0% +have done something a little bit smarter + + + align:start position:0% +have done something a little bit smarter +to make the function just a little + + align:start position:0% +to make the function just a little + + + align:start position:0% +to make the function just a little +faster with flags + + align:start position:0% + + + + align:start position:0% + +which you can try so see if you can have + + align:start position:0% +which you can try so see if you can have + + + align:start position:0% +which you can try so see if you can have +the program stop as soon as you hit 103 + + align:start position:0% +the program stop as soon as you hit 103 + + + align:start position:0% +the program stop as soon as you hit 103 +right see if you can write the program + + align:start position:0% +right see if you can write the program + + + align:start position:0% +right see if you can write the program +that uses a flag to uh trigger that + + align:start position:0% +that uses a flag to uh trigger that + + + align:start position:0% +that uses a flag to uh trigger that +event and then when that event is true + + align:start position:0% +event and then when that event is true + + + align:start position:0% +event and then when that event is true +just break out of the loop or return + + align:start position:0% +just break out of the loop or return + + + align:start position:0% +just break out of the loop or return +immediately or something like + + align:start position:0% + + + + align:start position:0% + +that other + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% +questions + + + align:start position:0% +questions +okay so let's zoom out a little bit on + + align:start position:0% +okay so let's zoom out a little bit on + + + align:start position:0% +okay so let's zoom out a little bit on +functions we did this a little a little + + align:start position:0% +functions we did this a little a little + + + align:start position:0% +functions we did this a little a little +bit last lecture uh this is a function + + align:start position:0% +bit last lecture uh this is a function + + + align:start position:0% +bit last lecture uh this is a function +that we actually wrote last lecture it + + align:start position:0% +that we actually wrote last lecture it + + + align:start position:0% +that we actually wrote last lecture it +was Su of odd numbers between A and B + + align:start position:0% +was Su of odd numbers between A and B + + + align:start position:0% +was Su of odd numbers between A and B +this was essentially our black box right + + align:start position:0% +this was essentially our black box right + + + align:start position:0% +this was essentially our black box right +remember that now we're that we're + + align:start position:0% +remember that now we're that we're + + + align:start position:0% +remember that now we're that we're +writing functions we are kind of + + align:start position:0% +writing functions we are kind of + + + align:start position:0% +writing functions we are kind of +separating ourselves as some as a + + align:start position:0% +separating ourselves as some as a + + + align:start position:0% +separating ourselves as some as a +programmer who writes a function right + + align:start position:0% +programmer who writes a function right + + + align:start position:0% +programmer who writes a function right +you basically make this nice modular + + align:start position:0% +you basically make this nice modular + + + align:start position:0% +you basically make this nice modular +piece of code that can be reused over + + align:start position:0% +piece of code that can be reused over + + + align:start position:0% +piece of code that can be reused over +and over again so we're separating that + + align:start position:0% +and over again so we're separating that + + + align:start position:0% +and over again so we're separating that +aspect from somebody who's using a + + align:start position:0% +aspect from somebody who's using a + + + align:start position:0% +aspect from somebody who's using a +function so once there's a function + + align:start position:0% +function so once there's a function + + + align:start position:0% +function so once there's a function +already written for you you just use it + + align:start position:0% +already written for you you just use it + + + align:start position:0% +already written for you you just use it +in code right like we used the bisection + + align:start position:0% +in code right like we used the bisection + + + align:start position:0% +in code right like we used the bisection +route here right I know we wrote it but + + align:start position:0% +route here right I know we wrote it but + + + align:start position:0% +route here right I know we wrote it but +I guess technically I wrote it but here + + align:start position:0% +I guess technically I wrote it but here + + + align:start position:0% +I guess technically I wrote it but here +we just kind of used it right and we + + align:start position:0% +we just kind of used it right and we + + + align:start position:0% +we just kind of used it right and we +used it to write this nicer more complex + + align:start position:0% +used it to write this nicer more complex + + + align:start position:0% +used it to write this nicer more complex +piece of code and so this is what we do + + align:start position:0% +piece of code and so this is what we do + + + align:start position:0% +piece of code and so this is what we do +we basically create this black box and + + align:start position:0% +we basically create this black box and + + + align:start position:0% +we basically create this black box and +once you know the specification or the + + align:start position:0% +once you know the specification or the + + + align:start position:0% +once you know the specification or the +dock string of the Black Box you don't + + align:start position:0% +dock string of the Black Box you don't + + + align:start position:0% +dock string of the Black Box you don't +need to know how it's implemented in + + align:start position:0% +need to know how it's implemented in + + + align:start position:0% +need to know how it's implemented in +order to use it um but what I wanted to + + align:start position:0% +order to use it um but what I wanted to + + + align:start position:0% +order to use it um but what I wanted to +mention is something I mentioned last + + align:start position:0% +mention is something I mentioned last + + + align:start position:0% +mention is something I mentioned last +lecture is the function definition is + + align:start position:0% +lecture is the function definition is + + + align:start position:0% +lecture is the function definition is +just creating a function object inside + + align:start position:0% +just creating a function object inside + + + align:start position:0% +just creating a function object inside +uh inside the memory and the name of + + align:start position:0% +uh inside the memory and the name of + + + align:start position:0% +uh inside the memory and the name of +this function object is the name of the + + align:start position:0% +this function object is the name of the + + + align:start position:0% +this function object is the name of the +function so if we're thinking about the + + align:start position:0% +function so if we're thinking about the + + + align:start position:0% +function so if we're thinking about the +the program there is the orange uh box + + align:start position:0% +the program there is the orange uh box + + + align:start position:0% +the program there is the orange uh box +we have an object that just happens to + + align:start position:0% +we have an object that just happens to + + + align:start position:0% +we have an object that just happens to +be a function which has some code + + align:start position:0% +be a function which has some code + + + align:start position:0% +be a function which has some code +associated with it whose name is some + + align:start position:0% +associated with it whose name is some + + + align:start position:0% +associated with it whose name is some +odd and kind of drawing a parallel to + + align:start position:0% +odd and kind of drawing a parallel to + + + align:start position:0% +odd and kind of drawing a parallel to +that is when we create just a variable + + align:start position:0% +that is when we create just a variable + + + align:start position:0% +that is when we create just a variable +as we have been so far right here we're + + align:start position:0% +as we have been so far right here we're + + + align:start position:0% +as we have been so far right here we're +creating an object to whose name is low + + align:start position:0% +creating an object to whose name is low + + + align:start position:0% +creating an object to whose name is low +so in that same way that black box is + + align:start position:0% +so in that same way that black box is + + + align:start position:0% +so in that same way that black box is +basically saying I am creating a + + align:start position:0% +basically saying I am creating a + + + align:start position:0% +basically saying I am creating a +function object that has some code + + align:start position:0% +function object that has some code + + + align:start position:0% +function object that has some code +associated with it whose name is some + + align:start position:0% +associated with it whose name is some + + + align:start position:0% +associated with it whose name is some +odd okay so in this case I've got some + + align:start position:0% +odd okay so in this case I've got some + + + align:start position:0% +odd okay so in this case I've got some +odd low and high as three sort of + + align:start position:0% +odd low and high as three sort of + + + align:start position:0% +odd low and high as three sort of +objects inside my program and then only + + align:start position:0% +objects inside my program and then only + + + align:start position:0% +objects inside my program and then only +when I make a function call does the uh + + align:start position:0% +when I make a function call does the uh + + + align:start position:0% +when I make a function call does the uh +code associated with the function object + + align:start position:0% +code associated with the function object + + + align:start position:0% +code associated with the function object +run right so up when I'm defining the + + align:start position:0% +run right so up when I'm defining the + + + align:start position:0% +run right so up when I'm defining the +function it does not not run it just + + align:start position:0% +function it does not not run it just + + + align:start position:0% +function it does not not run it just +stays inside computer memory as an + + align:start position:0% +stays inside computer memory as an + + + align:start position:0% +stays inside computer memory as an +object that exists and when I make my + + align:start position:0% +object that exists and when I make my + + + align:start position:0% +object that exists and when I make my +function call is when I use that object + + align:start position:0% +function call is when I use that object + + + align:start position:0% +function call is when I use that object +so the function call basically takes my + + align:start position:0% +so the function call basically takes my + + + align:start position:0% +so the function call basically takes my +variables and + + align:start position:0% +variables and + + + align:start position:0% +variables and +um and matches them to the function + + align:start position:0% +um and matches them to the function + + + align:start position:0% +um and matches them to the function +definition so a gets matched to low and + + align:start position:0% +definition so a gets matched to low and + + + align:start position:0% +definition so a gets matched to low and +B gets matched to high and low and high + + align:start position:0% +B gets matched to high and low and high + + + align:start position:0% +B gets matched to high and low and high +in the function call have actual values + + align:start position:0% +in the function call have actual values + + + align:start position:0% +in the function call have actual values +associated with them two and + + align:start position:0% +associated with them two and + + + align:start position:0% +associated with them two and +seven and so that function will then go + + align:start position:0% +seven and so that function will then go + + + align:start position:0% +seven and so that function will then go +ahead and do the work and at the end + + align:start position:0% +ahead and do the work and at the end + + + align:start position:0% +ahead and do the work and at the end +it's going to return something either an + + align:start position:0% +it's going to return something either an + + + align:start position:0% +it's going to return something either an +actual value or none and then that + + align:start position:0% +actual value or none and then that + + + align:start position:0% +actual value or none and then that +actual value replaces the entire + + align:start position:0% +actual value replaces the entire + + + align:start position:0% +actual value replaces the entire +function call so in my program the + + align:start position:0% +function call so in my program the + + + align:start position:0% +function call so in my program the +variable my sum here is going to be + + align:start position:0% +variable my sum here is going to be + + + align:start position:0% +variable my sum here is going to be +equal to the + + align:start position:0% +equal to the + + + align:start position:0% +equal to the +return just a little recap but hopefully + + align:start position:0% +return just a little recap but hopefully + + + align:start position:0% +return just a little recap but hopefully +this kind of keeps bringing that point + + align:start position:0% +this kind of keeps bringing that point + + + align:start position:0% +this kind of keeps bringing that point +home so now we're going to talk about in + + align:start position:0% +home so now we're going to talk about in + + + align:start position:0% +home so now we're going to talk about in +more detail what exactly happens when we + + align:start position:0% +more detail what exactly happens when we + + + align:start position:0% +more detail what exactly happens when we +make a function call so when we make a + + align:start position:0% +make a function call so when we make a + + + align:start position:0% +make a function call so when we make a +function call you can think of the + + align:start position:0% +function call you can think of the + + + align:start position:0% +function call you can think of the +program as sort of taking a pause right + + align:start position:0% +program as sort of taking a pause right + + + align:start position:0% +program as sort of taking a pause right +I've got my main program and in my main + + align:start position:0% +I've got my main program and in my main + + + align:start position:0% +I've got my main program and in my main +program I have a function call that main + + align:start position:0% +program I have a function call that main + + + align:start position:0% +program I have a function call that main +program will just pause for a bit and + + align:start position:0% +program will just pause for a bit and + + + align:start position:0% +program will just pause for a bit and +that function call you can treat it as + + align:start position:0% +that function call you can treat it as + + + align:start position:0% +that function call you can treat it as +sort of a little mini program that needs + + align:start position:0% +sort of a little mini program that needs + + + align:start position:0% +sort of a little mini program that needs +to run and terminate return of value + + align:start position:0% +to run and terminate return of value + + + align:start position:0% +to run and terminate return of value +before the main program can resume + + align:start position:0% +before the main program can resume + + + align:start position:0% +before the main program can resume +executing okay so that little mini + + align:start position:0% +executing okay so that little mini + + + align:start position:0% +executing okay so that little mini +program that function call basically + + align:start position:0% +program that function call basically + + + align:start position:0% +program that function call basically +creates its own little environment that + + align:start position:0% +creates its own little environment that + + + align:start position:0% +creates its own little environment that +it lives in right so in that little + + align:start position:0% +it lives in right so in that little + + + align:start position:0% +it lives in right so in that little +environment it can create variables just + + align:start position:0% +environment it can create variables just + + + align:start position:0% +environment it can create variables just +like we would in a regular program it + + align:start position:0% +like we would in a regular program it + + + align:start position:0% +like we would in a regular program it +can modify variables it can print things + + align:start position:0% +can modify variables it can print things + + + align:start position:0% +can modify variables it can print things +right it can do all this work within its + + align:start position:0% +right it can do all this work within its + + + align:start position:0% +right it can do all this work within its +body and at some point it'll finish its + + align:start position:0% +body and at some point it'll finish its + + + align:start position:0% +body and at some point it'll finish its +job finish its task and it'll have some + + align:start position:0% +job finish its task and it'll have some + + + align:start position:0% +job finish its task and it'll have some +value that's the result of all of that + + align:start position:0% +value that's the result of all of that + + + align:start position:0% +value that's the result of all of that +work that it did and that value is what + + align:start position:0% +work that it did and that value is what + + + align:start position:0% +work that it did and that value is what +it hopefully returns back to the main + + align:start position:0% +it hopefully returns back to the main + + + align:start position:0% +it hopefully returns back to the main +program and then the main program can + + align:start position:0% +program and then the main program can + + + align:start position:0% +program and then the main program can +can finish its can finish it its job + + align:start position:0% +can finish its can finish it its job + + + align:start position:0% +can finish its can finish it its job +okay so what what's key here is that + + align:start position:0% +okay so what what's key here is that + + + align:start position:0% +okay so what what's key here is that +every time you make a function call you + + align:start position:0% +every time you make a function call you + + + align:start position:0% +every time you make a function call you +basically create a new environment okay + + align:start position:0% +basically create a new environment okay + + + align:start position:0% +basically create a new environment okay +and that environment is completely + + align:start position:0% +and that environment is completely + + + align:start position:0% +and that environment is completely +separate from the main program + + align:start position:0% +separate from the main program + + + align:start position:0% +separate from the main program +environment as soon as the function call + + align:start position:0% +environment as soon as the function call + + + align:start position:0% +environment as soon as the function call +terminates that uh function call + + align:start position:0% +terminates that uh function call + + + align:start position:0% +terminates that uh function call +environment disappears so any variables + + align:start position:0% +environment disappears so any variables + + + align:start position:0% +environment disappears so any variables +that were created within that + + align:start position:0% +that were created within that + + + align:start position:0% +that were created within that +environment of the function call will + + align:start position:0% +environment of the function call will + + + align:start position:0% +environment of the function call will +also disappear okay so all we're left + + align:start position:0% +also disappear okay so all we're left + + + align:start position:0% +also disappear okay so all we're left +with is just what's in the main + + align:start position:0% +with is just what's in the main + + + align:start position:0% +with is just what's in the main +program so now we're going to talk a + + align:start position:0% +program so now we're going to talk a + + + align:start position:0% +program so now we're going to talk a +little bit about environments okay and + + align:start position:0% +little bit about environments okay and + + + align:start position:0% +little bit about environments okay and +if you understand this you'll understand + + align:start position:0% +if you understand this you'll understand + + + align:start position:0% +if you understand this you'll understand +80% of of functions and what to do with + + align:start position:0% +80% of of functions and what to do with + + + align:start position:0% +80% of of functions and what to do with +them okay so basically when you first + + align:start position:0% +them okay so basically when you first + + + align:start position:0% +them okay so basically when you first +run your program uh the program enters + + align:start position:0% +run your program uh the program enters + + + align:start position:0% +run your program uh the program enters +what we call the global environment the + + align:start position:0% +what we call the global environment the + + + align:start position:0% +what we call the global environment the +main program + + align:start position:0% +main program + + + align:start position:0% +main program +environment and anytime you make a + + align:start position:0% +environment and anytime you make a + + + align:start position:0% +environment and anytime you make a +function call we're creating this new + + align:start position:0% +function call we're creating this new + + + align:start position:0% +function call we're creating this new +environment okay so what exactly happens + + align:start position:0% +environment okay so what exactly happens + + + align:start position:0% +environment okay so what exactly happens +when we create these when we do these + + align:start position:0% +when we create these when we do these + + + align:start position:0% +when we create these when we do these +function calls how do these environments + + align:start position:0% +function calls how do these environments + + + align:start position:0% +function calls how do these environments +interact and the answer is they don't + + align:start position:0% +interact and the answer is they don't + + + align:start position:0% +interact and the answer is they don't +actually interfere with each each other + + align:start position:0% +actually interfere with each each other + + + align:start position:0% +actually interfere with each each other +that much they only interfere with each + + align:start position:0% +that much they only interfere with each + + + align:start position:0% +that much they only interfere with each +other through passing in parameters and + + align:start position:0% +other through passing in parameters and + + + align:start position:0% +other through passing in parameters and +through returning values but beyond that + + align:start position:0% +through returning values but beyond that + + + align:start position:0% +through returning values but beyond that +these two different environments the + + align:start position:0% +these two different environments the + + + align:start position:0% +these two different environments the +main program environment and a function + + align:start position:0% +main program environment and a function + + + align:start position:0% +main program environment and a function +call environment can actually have + + align:start position:0% +call environment can actually have + + + align:start position:0% +call environment can actually have +variables that have the same name but + + align:start position:0% +variables that have the same name but + + + align:start position:0% +variables that have the same name but +don't interfere with each other because + + align:start position:0% +don't interfere with each other because + + + align:start position:0% +don't interfere with each other because +they exist in different environments + + align:start position:0% +they exist in different environments + + + align:start position:0% +they exist in different environments +okay so we're going to look at this + + align:start position:0% +okay so we're going to look at this + + + align:start position:0% +okay so we're going to look at this +example uh to to Showcase that so here's + + align:start position:0% +example uh to to Showcase that so here's + + + align:start position:0% +example uh to to Showcase that so here's +a function it's pretty simple it does + + align:start position:0% +a function it's pretty simple it does + + + align:start position:0% +a function it's pretty simple it does +not do much it takes in one parameter uh + + align:start position:0% +not do much it takes in one parameter uh + + + align:start position:0% +not do much it takes in one parameter uh +probably a number and adds one to it + + align:start position:0% +probably a number and adds one to it + + + align:start position:0% +probably a number and adds one to it +right so takes in an X and uh does X+ + + align:start position:0% +right so takes in an X and uh does X+ + + + align:start position:0% +right so takes in an X and uh does X+ +One reassigns X to it and then it does + + align:start position:0% +One reassigns X to it and then it does + + + align:start position:0% +One reassigns X to it and then it does +this print statement and then Returns + + align:start position:0% +this print statement and then Returns + + + align:start position:0% +this print statement and then Returns +the new value of x so it added one to + + align:start position:0% +the new value of x so it added one to + + + align:start position:0% +the new value of x so it added one to +whatever you passed into it and it + + align:start position:0% +whatever you passed into it and it + + + align:start position:0% +whatever you passed into it and it +returns that new + + align:start position:0% +returns that new + + + align:start position:0% +returns that new +value so that's the definition again + + align:start position:0% +value so that's the definition again + + + align:start position:0% +value so that's the definition again +this just sits in Python memory it + + align:start position:0% +this just sits in Python memory it + + + align:start position:0% +this just sits in Python memory it +doesn't actually get run until we make a + + align:start position:0% +doesn't actually get run until we make a + + + align:start position:0% +doesn't actually get run until we make a +function call the parameter here when we + + align:start position:0% +function call the parameter here when we + + + align:start position:0% +function call the parameter here when we +wrote Our function are called formal + + align:start position:0% +wrote Our function are called formal + + + align:start position:0% +wrote Our function are called formal +parameters because there's no actual + + align:start position:0% +parameters because there's no actual + + + align:start position:0% +parameters because there's no actual +value associated with them right we're + + align:start position:0% +value associated with them right we're + + + align:start position:0% +value associated with them right we're +writing this function assuming that at + + align:start position:0% +writing this function assuming that at + + + align:start position:0% +writing this function assuming that at +some point we're going to get a value + + align:start position:0% +some point we're going to get a value + + + align:start position:0% +some point we're going to get a value +for x but at the time we're writing the + + align:start position:0% +for x but at the time we're writing the + + + align:start position:0% +for x but at the time we're writing the +function there's no value for x it's + + align:start position:0% +function there's no value for x it's + + + align:start position:0% +function there's no value for x it's +just this abstract variable okay and + + align:start position:0% +just this abstract variable okay and + + + align:start position:0% +just this abstract variable okay and +we're using that variable X within the + + align:start position:0% +we're using that variable X within the + + + align:start position:0% +we're using that variable X within the +function body assuming that at some + + align:start position:0% +function body assuming that at some + + + align:start position:0% +function body assuming that at some +point we're going to get an initial + + align:start position:0% +point we're going to get an initial + + + align:start position:0% +point we're going to get an initial +value for x right so X is equal to three + + align:start position:0% +value for x right so X is equal to three + + + align:start position:0% +value for x right so X is equal to three +and then at which point the body can + + align:start position:0% +and then at which point the body can + + + align:start position:0% +and then at which point the body can +then + + align:start position:0% +then + + + align:start position:0% +then +execute now when you make a function + + align:start position:0% +execute now when you make a function + + + align:start position:0% +execute now when you make a function +call in the main program scope that's + + align:start position:0% +call in the main program scope that's + + + align:start position:0% +call in the main program scope that's +when you uh pass make a function call + + align:start position:0% +when you uh pass make a function call + + + align:start position:0% +when you uh pass make a function call +with the with an actual parameter so + + align:start position:0% +with the with an actual parameter so + + + align:start position:0% +with the with an actual parameter so +here you'll notice I'm using the same + + align:start position:0% +here you'll notice I'm using the same + + + align:start position:0% +here you'll notice I'm using the same +name X but this x inside the main + + align:start position:0% +name X but this x inside the main + + + align:start position:0% +name X but this x inside the main +program is different than the X that's + + align:start position:0% +program is different than the X that's + + + align:start position:0% +program is different than the X that's +this formal parameter of the + + align:start position:0% +this formal parameter of the + + + align:start position:0% +this formal parameter of the +function this actual + + align:start position:0% +function this actual + + + align:start position:0% +function this actual +parameter when we make the function call + + align:start position:0% +parameter when we make the function call + + + align:start position:0% +parameter when we make the function call +is mapped to the formal parameter so at + + align:start position:0% +is mapped to the formal parameter so at + + + align:start position:0% +is mapped to the formal parameter so at +that point the formal parameter can get + + align:start position:0% +that point the formal parameter can get + + + align:start position:0% +that point the formal parameter can get +the value of the function call which is + + align:start position:0% +the value of the function call which is + + + align:start position:0% +the value of the function call which is +three okay and in fact it doesn't + + align:start position:0% +three okay and in fact it doesn't + + + align:start position:0% +three okay and in fact it doesn't +actually matter what we name this + + align:start position:0% +actually matter what we name this + + + align:start position:0% +actually matter what we name this +variable out here right we can name X is + + align:start position:0% +variable out here right we can name X is + + + align:start position:0% +variable out here right we can name X is +equal to three and make the function + + align:start position:0% +equal to three and make the function + + + align:start position:0% +equal to three and make the function +call F of of X but we can also have y is + + align:start position:0% +call F of of X but we can also have y is + + + align:start position:0% +call F of of X but we can also have y is +equal to 3 and we make the exact same + + align:start position:0% +equal to 3 and we make the exact same + + + align:start position:0% +equal to 3 and we make the exact same +function called f of Y right because we + + align:start position:0% +function called f of Y right because we + + + align:start position:0% +function called f of Y right because we +want to pass in three as a parameter to + + align:start position:0% +want to pass in three as a parameter to + + + align:start position:0% +want to pass in three as a parameter to +this function + + align:start position:0% +this function + + + align:start position:0% +this function +called okay so this x out here is + + align:start position:0% +called okay so this x out here is + + + align:start position:0% +called okay so this x out here is +different than this X over + + align:start position:0% +different than this X over + + + align:start position:0% +different than this X over +here so the re oh yeah go ahead which + + align:start position:0% +here so the re oh yeah go ahead which + + + align:start position:0% +here so the re oh yeah go ahead which +one is the formal the formal is the one + + align:start position:0% +one is the formal the formal is the one + + + align:start position:0% +one is the formal the formal is the one +from the function definition we say it's + + align:start position:0% +from the function definition we say it's + + + align:start position:0% +from the function definition we say it's +formal because there's no value + + align:start position:0% +formal because there's no value + + + align:start position:0% +formal because there's no value +associated with it when you first write + + align:start position:0% +associated with it when you first write + + + align:start position:0% +associated with it when you first write +the function right you write the + + align:start position:0% +the function right you write the + + + align:start position:0% +the function right you write the +function first there's nothing going on + + align:start position:0% +function first there's nothing going on + + + align:start position:0% +function first there's nothing going on +here and then you have some code that + + align:start position:0% +here and then you have some code that + + + align:start position:0% +here and then you have some code that +actually now is taking on some values + + align:start position:0% +actually now is taking on some values + + + align:start position:0% +actually now is taking on some values +and you can run + + align:start position:0% +and you can run + + + align:start position:0% +and you can run +it yeah so let's Trace through this code + + align:start position:0% +it yeah so let's Trace through this code + + + align:start position:0% +it yeah so let's Trace through this code +little by little to see exactly what + + align:start position:0% +little by little to see exactly what + + + align:start position:0% +little by little to see exactly what +environments get created uh as we make + + align:start position:0% +environments get created uh as we make + + + align:start position:0% +environments get created uh as we make +function calls so again this is my Black + + align:start position:0% +function calls so again this is my Black + + + align:start position:0% +function calls so again this is my Black +Box it's a + + align:start position:0% +Box it's a + + + align:start position:0% +Box it's a +function uh when I first run the program + + align:start position:0% +function uh when I first run the program + + + align:start position:0% +function uh when I first run the program +we finished the function definition so + + align:start position:0% +we finished the function definition so + + + align:start position:0% +we finished the function definition so +we're at this point in our program right + + align:start position:0% +we're at this point in our program right + + + align:start position:0% +we're at this point in our program right +before we do X is equal to 3 inside my + + align:start position:0% +before we do X is equal to 3 inside my + + + align:start position:0% +before we do X is equal to 3 inside my +sort of computer python memory what I + + align:start position:0% +sort of computer python memory what I + + + align:start position:0% +sort of computer python memory what I +have is one environment created and + + align:start position:0% +have is one environment created and + + + align:start position:0% +have is one environment created and +that's the environment of the main + + align:start position:0% +that's the environment of the main + + + align:start position:0% +that's the environment of the main +program the only thing I have in this + + align:start position:0% +program the only thing I have in this + + + align:start position:0% +program the only thing I have in this +environment is by F right because at + + align:start position:0% +environment is by F right because at + + + align:start position:0% +environment is by F right because at +this point in the program where the red + + align:start position:0% +this point in the program where the red + + + align:start position:0% +this point in the program where the red +uh arrow is I just had a function + + align:start position:0% +uh arrow is I just had a function + + + align:start position:0% +uh arrow is I just had a function +definition so again it's a definition + + align:start position:0% +definition so again it's a definition + + + align:start position:0% +definition so again it's a definition +it's it's a function whose name is f and + + align:start position:0% +it's it's a function whose name is f and + + + align:start position:0% +it's it's a function whose name is f and +it's an object right I it's not being + + align:start position:0% +it's an object right I it's not being + + + align:start position:0% +it's an object right I it's not being +run quite yet it's an object that + + align:start position:0% +run quite yet it's an object that + + + align:start position:0% +run quite yet it's an object that +contains some + + align:start position:0% +contains some + + + align:start position:0% +contains some +code now we have X is equal to three so + + align:start position:0% +code now we have X is equal to three so + + + align:start position:0% +code now we have X is equal to three so +that's pretty easy inside my main + + align:start position:0% +that's pretty easy inside my main + + + align:start position:0% +that's pretty easy inside my main +program environment I've got a variable + + align:start position:0% +program environment I've got a variable + + + align:start position:0% +program environment I've got a variable +named X whose value is + + align:start position:0% +named X whose value is + + + align:start position:0% +named X whose value is +three and then I have my function call + + align:start position:0% +three and then I have my function call + + + align:start position:0% +three and then I have my function call +so as soon as python sees a function + + align:start position:0% +so as soon as python sees a function + + + align:start position:0% +so as soon as python sees a function +call it creates a new environment and + + align:start position:0% +call it creates a new environment and + + + align:start position:0% +call it creates a new environment and +the current environment where the call + + align:start position:0% +the current environment where the call + + + align:start position:0% +the current environment where the call +is being made from so the main program + + align:start position:0% +is being made from so the main program + + + align:start position:0% +is being made from so the main program +one will be put on hold okay so here I'm + + align:start position:0% +one will be put on hold okay so here I'm + + + align:start position:0% +one will be put on hold okay so here I'm +calling function f so now I'm creating + + align:start position:0% +calling function f so now I'm creating + + + align:start position:0% +calling function f so now I'm creating +this new environment that think of it + + align:start position:0% +this new environment that think of it + + + align:start position:0% +this new environment that think of it +like this mini program this little task + + align:start position:0% +like this mini program this little task + + + align:start position:0% +like this mini program this little task +that needs to get done before the main + + align:start position:0% +that needs to get done before the main + + + align:start position:0% +that needs to get done before the main +program can continue + + align:start position:0% +program can continue + + + align:start position:0% +program can continue +executing so I need to figure out what's + + align:start position:0% +executing so I need to figure out what's + + + align:start position:0% +executing so I need to figure out what's +going on in this mini program right in + + align:start position:0% +going on in this mini program right in + + + align:start position:0% +going on in this mini program right in +this function called to F all right so + + align:start position:0% +this function called to F all right so + + + align:start position:0% +this function called to F all right so +here's my new environment the scope of f + + align:start position:0% +here's my new environment the scope of f + + + align:start position:0% +here's my new environment the scope of f +the first thing that we need to do is + + align:start position:0% +the first thing that we need to do is + + + align:start position:0% +the first thing that we need to do is +figure out what are the parameters of f + + align:start position:0% +figure out what are the parameters of f + + + align:start position:0% +figure out what are the parameters of f +so we look at the function definition + + align:start position:0% +so we look at the function definition + + + align:start position:0% +so we look at the function definition +and we see it has one parameter named X + + align:start position:0% +and we see it has one parameter named X + + + align:start position:0% +and we see it has one parameter named X +so we're going to take that X and the + + align:start position:0% +so we're going to take that X and the + + + align:start position:0% +so we're going to take that X and the +first thing we're going to do is map the + + align:start position:0% +first thing we're going to do is map the + + + align:start position:0% +first thing we're going to do is map the +formal parameter to the actual parameter + + align:start position:0% +formal parameter to the actual parameter + + + align:start position:0% +formal parameter to the actual parameter +okay so we're going to make the formal + + align:start position:0% +okay so we're going to make the formal + + + align:start position:0% +okay so we're going to make the formal +parameter of f named X take on the value + + align:start position:0% +parameter of f named X take on the value + + + align:start position:0% +parameter of f named X take on the value +three + + align:start position:0% +three + + + align:start position:0% +three +okay that's kind of what we've been + + align:start position:0% +okay that's kind of what we've been + + + align:start position:0% +okay that's kind of what we've been +doing already but now this is getting + + align:start position:0% +doing already but now this is getting + + + align:start position:0% +doing already but now this is getting +getting down to sort of details just + + align:start position:0% +getting down to sort of details just + + + align:start position:0% +getting down to sort of details just +details we've mapped all the parameters + + align:start position:0% +details we've mapped all the parameters + + + align:start position:0% +details we've mapped all the parameters +the body of the function executes I've + + align:start position:0% +the body of the function executes I've + + + align:start position:0% +the body of the function executes I've +again kind of blurred out this one + + align:start position:0% +again kind of blurred out this one + + + align:start position:0% +again kind of blurred out this one +because we're not in this Global scope + + align:start position:0% +because we're not in this Global scope + + + align:start position:0% +because we're not in this Global scope +we're trying to figure out what f is + + align:start position:0% +we're trying to figure out what f is + + + align:start position:0% +we're trying to figure out what f is +doing so the body of f says take X add + + align:start position:0% +doing so the body of f says take X add + + + align:start position:0% +doing so the body of f says take X add +one to it and reassign it to X so what's + + align:start position:0% +one to it and reassign it to X so what's + + + align:start position:0% +one to it and reassign it to X so what's +X inside my function it's three we add + + align:start position:0% +X inside my function it's three we add + + + align:start position:0% +X inside my function it's three we add +one to it and we make X be before + + align:start position:0% +one to it and we make X be before + + + align:start position:0% +one to it and we make X be before +uh I skipped one thing which is if in my + + align:start position:0% +uh I skipped one thing which is if in my + + + align:start position:0% +uh I skipped one thing which is if in my +main program I had Y is equal to 3 and F + + align:start position:0% +main program I had Y is equal to 3 and F + + + align:start position:0% +main program I had Y is equal to 3 and F +of Y nothing really would have changed + + align:start position:0% +of Y nothing really would have changed + + + align:start position:0% +of Y nothing really would have changed +right my formal parameter of f is still + + align:start position:0% +right my formal parameter of f is still + + + align:start position:0% +right my formal parameter of f is still +X and I'm still mapping x to the value + + align:start position:0% +X and I'm still mapping x to the value + + + align:start position:0% +X and I'm still mapping x to the value +that's uh in my uh here in the actual + + align:start position:0% +that's uh in my uh here in the actual + + + align:start position:0% +that's uh in my uh here in the actual +parameter okay so in my scope of f I've + + align:start position:0% +parameter okay so in my scope of f I've + + + align:start position:0% +parameter okay so in my scope of f I've +got X is three I incremented by one it + + align:start position:0% +got X is three I incremented by one it + + + align:start position:0% +got X is three I incremented by one it +gives me four and I resave it back into + + align:start position:0% +gives me four and I resave it back into + + + align:start position:0% +gives me four and I resave it back into +X and again there's 's no collusion + + align:start position:0% +X and again there's 's no collusion + + + align:start position:0% +X and again there's 's no collusion +there's no Collision here right in terms + + align:start position:0% +there's no Collision here right in terms + + + align:start position:0% +there's no Collision here right in terms +of naming because the scope of f the + + align:start position:0% +of naming because the scope of f the + + + align:start position:0% +of naming because the scope of f the +environment at F has a variable named X + + align:start position:0% +environment at F has a variable named X + + + align:start position:0% +environment at F has a variable named X +and I'm just doing stuff with the x that + + align:start position:0% +and I'm just doing stuff with the x that + + + align:start position:0% +and I'm just doing stuff with the x that +F + + align:start position:0% +F + + + align:start position:0% +F +knows I do have another X inside my + + align:start position:0% +knows I do have another X inside my + + + align:start position:0% +knows I do have another X inside my +Global scope but that one's put on hold + + align:start position:0% +Global scope but that one's put on hold + + + align:start position:0% +Global scope but that one's put on hold +for now okay all right so I've done xal + + align:start position:0% +for now okay all right so I've done xal + + + align:start position:0% +for now okay all right so I've done xal +x + one then I do the print statement so + + align:start position:0% +x + one then I do the print statement so + + + align:start position:0% +x + one then I do the print statement so +in f ofx x = 4 that gets printed out and + + align:start position:0% +in f ofx x = 4 that gets printed out and + + + align:start position:0% +in f ofx x = 4 that gets printed out and +then I return X so the thing that gets + + align:start position:0% +then I return X so the thing that gets + + + align:start position:0% +then I return X so the thing that gets +returned is the value of x so four + + align:start position:0% +returned is the value of x so four + + + align:start position:0% +returned is the value of x so four +and this again replaces the function + + align:start position:0% +and this again replaces the function + + + align:start position:0% +and this again replaces the function +call so this gets returned back to + + align:start position:0% +call so this gets returned back to + + + align:start position:0% +call so this gets returned back to +whoever called me and the environment + + align:start position:0% +whoever called me and the environment + + + align:start position:0% +whoever called me and the environment +that called me was just by main program + + align:start position:0% +that called me was just by main program + + + align:start position:0% +that called me was just by main program +and here I'm going to return four and + + align:start position:0% +and here I'm going to return four and + + + align:start position:0% +and here I'm going to return four and +this is going to replace that with four + + align:start position:0% +this is going to replace that with four + + + align:start position:0% +this is going to replace that with four +as soon as the function sees the + + align:start position:0% +as soon as the function sees the + + + align:start position:0% +as soon as the function sees the +return and returns that value back it + + align:start position:0% +return and returns that value back it + + + align:start position:0% +return and returns that value back it +goes away so notice that X that we had + + align:start position:0% +goes away so notice that X that we had + + + align:start position:0% +goes away so notice that X that we had +created is gone now we're in the main + + align:start position:0% +created is gone now we're in the main + + + align:start position:0% +created is gone now we're in the main +program there's no there's no confusion + + align:start position:0% +program there's no there's no confusion + + + align:start position:0% +program there's no there's no confusion +right my main program has its own X that + + align:start position:0% +right my main program has its own X that + + + align:start position:0% +right my main program has its own X that +other X that was part of of the + + align:start position:0% +other X that was part of of the + + + align:start position:0% +other X that was part of of the +execution of f is gone because that + + align:start position:0% +execution of f is gone because that + + + align:start position:0% +execution of f is gone because that +function finished its job and it doesn't + + align:start position:0% +function finished its job and it doesn't + + + align:start position:0% +function finished its job and it doesn't +need its environment anymore so now the + + align:start position:0% +need its environment anymore so now the + + + align:start position:0% +need its environment anymore so now the +return of the function replaces F ofx + + align:start position:0% +return of the function replaces F ofx + + + align:start position:0% +return of the function replaces F ofx +and we see Z is equal to + + align:start position:0% +and we see Z is equal to + + + align:start position:0% +and we see Z is equal to +4 okay that was super + + align:start position:0% +4 okay that was super + + + align:start position:0% +4 okay that was super +detailed um but that's kind of what + + align:start position:0% +detailed um but that's kind of what + + + align:start position:0% +detailed um but that's kind of what +happens step by step when we make a + + align:start position:0% +happens step by step when we make a + + + align:start position:0% +happens step by step when we make a +function call with the new environments + + align:start position:0% +function call with the new environments + + + align:start position:0% +function call with the new environments +being created so if you can understand + + align:start position:0% +being created so if you can understand + + + align:start position:0% +being created so if you can understand +that it should be uh it should be pretty + + align:start position:0% +that it should be uh it should be pretty + + + align:start position:0% +that it should be uh it should be pretty +straightforward not you know and you + + align:start position:0% +straightforward not you know and you + + + align:start position:0% +straightforward not you know and you +won't get confused when you see an X out + + align:start position:0% +won't get confused when you see an X out + + + align:start position:0% +won't get confused when you see an X out +here you have F ofx you know as one + + align:start position:0% +here you have F ofx you know as one + + + align:start position:0% +here you have F ofx you know as one +function and then maybe another function + + align:start position:0% +function and then maybe another function + + + align:start position:0% +function and then maybe another function +that has G of X um and so + + align:start position:0% +that has G of X um and so + + + align:start position:0% +that has G of X um and so +on okay so in order to know the scope + + align:start position:0% +on okay so in order to know the scope + + + align:start position:0% +on okay so in order to know the scope +that you're in the environment that you + + align:start position:0% +that you're in the environment that you + + + align:start position:0% +that you're in the environment that you +in you need to know what expression + + align:start position:0% +in you need to know what expression + + + align:start position:0% +in you need to know what expression +you're evaluating right so here we were + + align:start position:0% +you're evaluating right so here we were + + + align:start position:0% +you're evaluating right so here we were +evaluating this function call so that + + align:start position:0% +evaluating this function call so that + + + align:start position:0% +evaluating this function call so that +means that we were inside the + + align:start position:0% +means that we were inside the + + + align:start position:0% +means that we were inside the +environment of + + align:start position:0% +environment of + + + align:start position:0% +environment of +f another example and this one's a + + align:start position:0% +f another example and this one's a + + + align:start position:0% +f another example and this one's a +little bit weird it shows some of the + + align:start position:0% +little bit weird it shows some of the + + + align:start position:0% +little bit weird it shows some of the +nuances of + + align:start position:0% +nuances of + + + align:start position:0% +nuances of +python + + align:start position:0% +python + + + align:start position:0% +python +um and these aren't necessarily true in + + align:start position:0% +um and these aren't necessarily true in + + + align:start position:0% +um and these aren't necessarily true in +other languages so I'm just going to do + + align:start position:0% +other languages so I'm just going to do + + + align:start position:0% +other languages so I'm just going to do +the drawing of the Scopes out + + align:start position:0% +the drawing of the Scopes out + + + align:start position:0% +the drawing of the Scopes out +here so let's start with the one on the + + align:start position:0% +here so let's start with the one on the + + + align:start position:0% +here so let's start with the one on the +left so you can see here I've got one + + align:start position:0% +left so you can see here I've got one + + + align:start position:0% +left so you can see here I've got one +function f of Y and I've got the main + + align:start position:0% +function f of Y and I've got the main + + + align:start position:0% +function f of Y and I've got the main +program that creates X is equal to 5 and + + align:start position:0% +program that creates X is equal to 5 and + + + align:start position:0% +program that creates X is equal to 5 and +then a call to Y so inside my main + + align:start position:0% +then a call to Y so inside my main + + + align:start position:0% +then a call to Y so inside my main +program I've got X is equal to + + align:start position:0% +program I've got X is equal to + + + align:start position:0% +program I've got X is equal to +5 and then I have a function called to X + + align:start position:0% +5 and then I have a function called to X + + + align:start position:0% +5 and then I have a function called to X +function call means we need to create a + + align:start position:0% +function call means we need to create a + + + align:start position:0% +function call means we need to create a +new scope so this one's put on hold for + + align:start position:0% +new scope so this one's put on hold for + + + align:start position:0% +new scope so this one's put on hold for +now until we figure out what F + + align:start position:0% +now until we figure out what F + + + align:start position:0% +now until we figure out what F +parentheses x is right here okay so the + + align:start position:0% +parentheses x is right here okay so the + + + align:start position:0% +parentheses x is right here okay so the +first thing we need to do is grab F and + + align:start position:0% +first thing we need to do is grab F and + + + align:start position:0% +first thing we need to do is grab F and +take all the formal parameters of f + + align:start position:0% +take all the formal parameters of f + + + align:start position:0% +take all the formal parameters of f +there's one its name is y and map them + + align:start position:0% +there's one its name is y and map them + + + align:start position:0% +there's one its name is y and map them +to the actual parameters so I'm calling + + align:start position:0% +to the actual parameters so I'm calling + + + align:start position:0% +to the actual parameters so I'm calling +f with five so I'm going to map y to + + align:start position:0% +f with five so I'm going to map y to + + + align:start position:0% +f with five so I'm going to map y to +five this function is going to take uh + + align:start position:0% +five this function is going to take uh + + + align:start position:0% +five this function is going to take uh +uh now do its the body of its function X + + align:start position:0% +uh now do its the body of its function X + + + align:start position:0% +uh now do its the body of its function X +is equal to one so it creates also an X + + align:start position:0% +is equal to one so it creates also an X + + + align:start position:0% +is equal to one so it creates also an X +whose value is one just within its scope + + align:start position:0% +whose value is one just within its scope + + + align:start position:0% +whose value is one just within its scope +it adds one to X so this becomes + + align:start position:0% +it adds one to X so this becomes + + + align:start position:0% +it adds one to X so this becomes +two and then it prints X so it's going + + align:start position:0% +two and then it prints X so it's going + + + align:start position:0% +two and then it prints X so it's going +to print + + align:start position:0% +to print + + + align:start position:0% +to print +two and then the function terminates it + + align:start position:0% +two and then the function terminates it + + + align:start position:0% +two and then the function terminates it +returns none right there's no return + + align:start position:0% +returns none right there's no return + + + align:start position:0% +returns none right there's no return +statement and it the function is done so + + align:start position:0% +statement and it the function is done so + + + align:start position:0% +statement and it the function is done so +this line has now finished + + align:start position:0% +this line has now finished + + + align:start position:0% +this line has now finished +and the last thing that the function + + align:start position:0% +and the last thing that the function + + + align:start position:0% +and the last thing that the function +does after it's done the return is the + + align:start position:0% +does after it's done the return is the + + + align:start position:0% +does after it's done the return is the +scope goes away and the last thing we + + align:start position:0% +scope goes away and the last thing we + + + align:start position:0% +scope goes away and the last thing we +need to do now is print X so this will + + align:start position:0% +need to do now is print X so this will + + + align:start position:0% +need to do now is print X so this will +print the value of x in the global scope + + align:start position:0% +print the value of x in the global scope + + + align:start position:0% +print the value of x in the global scope +which is five so the output of this a + + align:start position:0% +which is five so the output of this a + + + align:start position:0% +which is five so the output of this a +little piece of code on the left side + + align:start position:0% +little piece of code on the left side + + + align:start position:0% +little piece of code on the left side +here is two and + + align:start position:0% + + + + align:start position:0% + +five okay what about the middle + + align:start position:0% +five okay what about the middle + + + align:start position:0% +five okay what about the middle +code similarly I've got a function + + align:start position:0% +code similarly I've got a function + + + align:start position:0% +code similarly I've got a function +definition and then I create X is equal + + align:start position:0% +definition and then I create X is equal + + + align:start position:0% +definition and then I create X is equal +to 5 and then I make a call to G all + + align:start position:0% +to 5 and then I make a call to G all + + + align:start position:0% +to 5 and then I make a call to G all +right X is 5 so as soon as I see a + + align:start position:0% +right X is 5 so as soon as I see a + + + align:start position:0% +right X is 5 so as soon as I see a +function call I need to create a new + + align:start position:0% +function call I need to create a new + + + align:start position:0% +function call I need to create a new +scope and I need to map all the formal + + align:start position:0% +scope and I need to map all the formal + + + align:start position:0% +scope and I need to map all the formal +parameters of G it has one formal + + align:start position:0% +parameters of G it has one formal + + + align:start position:0% +parameters of G it has one formal +parameter its name is y that one will be + + align:start position:0% +parameter its name is y that one will be + + + align:start position:0% +parameter its name is y that one will be +mapped to whatever I made the function + + align:start position:0% +mapped to whatever I made the function + + + align:start position:0% +mapped to whatever I made the function +call with five right X is five out here + + align:start position:0% +call with five right X is five out here + + + align:start position:0% +call with five right X is five out here +so that gets mapped to five + + align:start position:0% +so that gets mapped to five + + + align:start position:0% +so that gets mapped to five +what is this function going to do well + + align:start position:0% +what is this function going to do well + + + align:start position:0% +what is this function going to do well +it prints + + align:start position:0% +it prints + + + align:start position:0% +it prints +X what's X inside the scope of + + align:start position:0% +X what's X inside the scope of + + + align:start position:0% +X what's X inside the scope of +G do I have a g inside F an X inside G + + align:start position:0% +G do I have a g inside F an X inside G + + + align:start position:0% +G do I have a g inside F an X inside G +no so this is something that python does + + align:start position:0% +no so this is something that python does + + + align:start position:0% +no so this is something that python does +it says well if your environment doesn't + + align:start position:0% +it says well if your environment doesn't + + + align:start position:0% +it says well if your environment doesn't +have a variable named X in this case + + align:start position:0% +have a variable named X in this case + + + align:start position:0% +have a variable named X in this case +look further out and see who called you + + align:start position:0% +look further out and see who called you + + + align:start position:0% +look further out and see who called you +well which environment called this + + align:start position:0% +well which environment called this + + + align:start position:0% +well which environment called this +G the main one right does your bigger + + align:start position:0% +G the main one right does your bigger + + + align:start position:0% +G the main one right does your bigger +environment the one who called you have + + align:start position:0% +environment the one who called you have + + + align:start position:0% +environment the one who called you have +a variable named X it does right it's + + align:start position:0% +a variable named X it does right it's + + + align:start position:0% +a variable named X it does right it's +five so python grabs the value + + align:start position:0% +five so python grabs the value + + + align:start position:0% +five so python grabs the value +associated with that larger environment + + align:start position:0% +associated with that larger environment + + + align:start position:0% +associated with that larger environment +and if that larger environment didn't + + align:start position:0% +and if that larger environment didn't + + + align:start position:0% +and if that larger environment didn't +have one it would look further out and + + align:start position:0% +have one it would look further out and + + + align:start position:0% +have one it would look further out and +further out out until it doesn't have an + + align:start position:0% +further out out until it doesn't have an + + + align:start position:0% +further out out until it doesn't have an +environment to look at so G is going to + + align:start position:0% +environment to look at so G is going to + + + align:start position:0% +environment to look at so G is going to +print the value of x which is + + align:start position:0% +print the value of x which is + + + align:start position:0% +print the value of x which is +five and then it's going to print X + 1 + + align:start position:0% +five and then it's going to print X + 1 + + + align:start position:0% +five and then it's going to print X + 1 +which is six and then it's + + align:start position:0% +which is six and then it's + + + align:start position:0% +which is six and then it's +done it returns none and then as soon as + + align:start position:0% +done it returns none and then as soon as + + + align:start position:0% +done it returns none and then as soon as +it returns none this scope goes + + align:start position:0% +it returns none this scope goes + + + align:start position:0% +it returns none this scope goes +away and what we're left with is the + + align:start position:0% +away and what we're left with is the + + + align:start position:0% +away and what we're left with is the +global program and we print X which is + + align:start position:0% +global program and we print X which is + + + align:start position:0% +global program and we print X which is +still five what I want you to notice is + + align:start position:0% +still five what I want you to notice is + + + align:start position:0% +still five what I want you to notice is +that that function G printed x + one but + + align:start position:0% +that that function G printed x + one but + + + align:start position:0% +that that function G printed x + one but +never modified + + align:start position:0% +never modified + + + align:start position:0% +never modified +X right we never said you know something + + align:start position:0% +X right we never said you know something + + + align:start position:0% +X right we never said you know something +like X is equal x plus one or something + + align:start position:0% +like X is equal x plus one or something + + + align:start position:0% +like X is equal x plus one or something +like that that we just figured out what + + align:start position:0% +like that that we just figured out what + + + align:start position:0% +like that that we just figured out what +X+ one was and printed + + align:start position:0% +X+ one was and printed + + + align:start position:0% +X+ one was and printed +it + + align:start position:0% +it + + + align:start position:0% +it +okay all right one more example and this + + align:start position:0% +okay all right one more example and this + + + align:start position:0% +okay all right one more example and this +one will actually end up in an error so + + align:start position:0% +one will actually end up in an error so + + + align:start position:0% +one will actually end up in an error so +here I've got X is equal to 5 just like + + align:start position:0% +here I've got X is equal to 5 just like + + + align:start position:0% +here I've got X is equal to 5 just like +before and then I have a function call + + align:start position:0% +before and then I have a function call + + + align:start position:0% +before and then I have a function call +to H so again a function call means a + + align:start position:0% +to H so again a function call means a + + + align:start position:0% +to H so again a function call means a +new scope is created I've got one + + align:start position:0% +new scope is created I've got one + + + align:start position:0% +new scope is created I've got one +variable y That's My formal parameter it + + align:start position:0% +variable y That's My formal parameter it + + + align:start position:0% +variable y That's My formal parameter it +gets mapped to whatever I call the + + align:start position:0% +gets mapped to whatever I call the + + + align:start position:0% +gets mapped to whatever I call the +function with five oops that's an S um + + align:start position:0% +function with five oops that's an S um + + + align:start position:0% +function with five oops that's an S um +and then what is this function doing + + align:start position:0% +and then what is this function doing + + + align:start position:0% +and then what is this function doing +that line x + = + + align:start position:0% +that line x + = + + + align:start position:0% +that line x + = +1 is X = x + + + align:start position:0% + + + + align:start position:0% + +1 this is actually an error python + + align:start position:0% +1 this is actually an error python + + + align:start position:0% +1 this is actually an error python +doesn't let you do that and the error it + + align:start position:0% +doesn't let you do that and the error it + + + align:start position:0% +doesn't let you do that and the error it +gives you is actually what it says there + + align:start position:0% +gives you is actually what it says there + + + align:start position:0% +gives you is actually what it says there +so Unbound local error local variable X + + align:start position:0% +so Unbound local error local variable X + + + align:start position:0% +so Unbound local error local variable X +is refer refed before an + + align:start position:0% +is refer refed before an + + + align:start position:0% +is refer refed before an +assignment so it doesn't actually grab + + align:start position:0% +assignment so it doesn't actually grab + + + align:start position:0% +assignment so it doesn't actually grab +the value from the outer scope like we + + align:start position:0% +the value from the outer scope like we + + + align:start position:0% +the value from the outer scope like we +did in the middle bit it doesn't grab it + + align:start position:0% +did in the middle bit it doesn't grab it + + + align:start position:0% +did in the middle bit it doesn't grab it +because it thinks you're trying to + + align:start position:0% +because it thinks you're trying to + + + align:start position:0% +because it thinks you're trying to +create a variable named X + + align:start position:0% +create a variable named X + + + align:start position:0% +create a variable named X +inside + + align:start position:0% +inside + + + align:start position:0% +inside +H and you're trying to add one to + + align:start position:0% +H and you're trying to add one to + + + align:start position:0% +H and you're trying to add one to +X but you never had a line that said X + + align:start position:0% +X but you never had a line that said X + + + align:start position:0% +X but you never had a line that said X +is equal to something originally inside + + align:start position:0% +is equal to something originally inside + + + align:start position:0% +is equal to something originally inside +h + + align:start position:0% + + + + align:start position:0% + +okay and so when you're trying to say x + + align:start position:0% +okay and so when you're trying to say x + + + align:start position:0% +okay and so when you're trying to say x +is equal x + 1 it's trying to look for + + align:start position:0% +is equal x + 1 it's trying to look for + + + align:start position:0% +is equal x + 1 it's trying to look for +an X inside the scope of + + align:start position:0% +an X inside the scope of + + + align:start position:0% +an X inside the scope of +H but it doesn't have one and so that's + + align:start position:0% +H but it doesn't have one and so that's + + + align:start position:0% +H but it doesn't have one and so that's +where we get that error from + + align:start position:0% +where we get that error from + + + align:start position:0% +where we get that error from +okay and this is not some I mean it's + + align:start position:0% +okay and this is not some I mean it's + + + align:start position:0% +okay and this is not some I mean it's +it's just the Nuance of python but it's + + align:start position:0% +it's just the Nuance of python but it's + + + align:start position:0% +it's just the Nuance of python but it's +kind of important to understand that you + + align:start position:0% +kind of important to understand that you + + + align:start position:0% +kind of important to understand that you +can access + + align:start position:0% +can access + + + align:start position:0% +can access +variables but you can't change variables + + align:start position:0% +variables but you can't change variables + + + align:start position:0% +variables but you can't change variables +outside of your scope okay so the middle + + align:start position:0% +outside of your scope okay so the middle + + + align:start position:0% +outside of your scope okay so the middle +one just accesses a variable adds one to + + align:start position:0% +one just accesses a variable adds one to + + + align:start position:0% +one just accesses a variable adds one to +it and prints it but we never said X is + + align:start position:0% +it and prints it but we never said X is + + + align:start position:0% +it and prints it but we never said X is +equal to this value okay and it's kind + + align:start position:0% +equal to this value okay and it's kind + + + align:start position:0% +equal to this value okay and it's kind +of like I guess the error you get is + + align:start position:0% +of like I guess the error you get is + + + align:start position:0% +of like I guess the error you get is +kind of like if you made this be + + align:start position:0% +kind of like if you made this be + + + align:start position:0% +kind of like if you made this be +something completely different like Z + + align:start position:0% +something completely different like Z + + + align:start position:0% +something completely different like Z +you would get the same error you know it + + align:start position:0% +you would get the same error you know it + + + align:start position:0% +you would get the same error you know it +would be error uh variable z uh + + align:start position:0% +would be error uh variable z uh + + + align:start position:0% +would be error uh variable z uh +referenced before assignment right it's + + align:start position:0% +referenced before assignment right it's + + + align:start position:0% +referenced before assignment right it's +like you can grab X+ one but I don't + + align:start position:0% +like you can grab X+ one but I don't + + + align:start position:0% +like you can grab X+ one but I don't +know what Z is something + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +like and then do + + align:start position:0% +like and then do + + + align:start position:0% +like and then do +like you're taking it from outside and + + align:start position:0% +like you're taking it from outside and + + + align:start position:0% +like you're taking it from outside and +like so if you uh no because if you want + + align:start position:0% +like so if you uh no because if you want + + + align:start position:0% +like so if you uh no because if you want +to if you want to explicitly say that + + align:start position:0% +to if you want to explicitly say that + + + align:start position:0% +to if you want to explicitly say that +you're taking it from outside there's a + + align:start position:0% +you're taking it from outside there's a + + + align:start position:0% +you're taking it from outside there's a +keyword called Global that you'd need to + + align:start position:0% +keyword called Global that you'd need to + + + align:start position:0% +keyword called Global that you'd need to +write that explicitly says hey I'm + + align:start position:0% +write that explicitly says hey I'm + + + align:start position:0% +write that explicitly says hey I'm +grabbing this Val variable that is not + + align:start position:0% +grabbing this Val variable that is not + + + align:start position:0% +grabbing this Val variable that is not +part of me it's part of the it's in the + + align:start position:0% +part of me it's part of the it's in the + + + align:start position:0% +part of me it's part of the it's in the +you know the main program the global + + align:start position:0% + + + + align:start position:0% + +scope okay the last thing I want to talk + + align:start position:0% +scope okay the last thing I want to talk + + + align:start position:0% +scope okay the last thing I want to talk +about is using functions as arguments to + + align:start position:0% +about is using functions as arguments to + + + align:start position:0% +about is using functions as arguments to +other functions so + + align:start position:0% +other functions so + + + align:start position:0% +other functions so +um the way I've sort of been explaining + + align:start position:0% +um the way I've sort of been explaining + + + align:start position:0% +um the way I've sort of been explaining +a function definition is basically + + align:start position:0% +a function definition is basically + + + align:start position:0% +a function definition is basically +saying that when we Define a function + + align:start position:0% +saying that when we Define a function + + + align:start position:0% +saying that when we Define a function +python essentially puts some code in + + align:start position:0% +python essentially puts some code in + + + align:start position:0% +python essentially puts some code in +memory whose name is the function name + + align:start position:0% +memory whose name is the function name + + + align:start position:0% +memory whose name is the function name +right so basically the function name + + align:start position:0% +right so basically the function name + + + align:start position:0% +right so basically the function name +creates for me an object inside memory + + align:start position:0% +creates for me an object inside memory + + + align:start position:0% +creates for me an object inside memory +that happens to be a function object and + + align:start position:0% +that happens to be a function object and + + + align:start position:0% +that happens to be a function object and +just to show you sort of what that means + + align:start position:0% +just to show you sort of what that means + + + align:start position:0% +just to show you sort of what that means +is uh we have a function is even right + + align:start position:0% +is uh we have a function is even right + + + align:start position:0% +is uh we have a function is even right +we've definitely created it if we say + + align:start position:0% +we've definitely created it if we say + + + align:start position:0% +we've definitely created it if we say +the type of is + + align:start position:0% +the type of is + + + align:start position:0% +the type of is +even it's function right so the function + + align:start position:0% +even it's function right so the function + + + align:start position:0% +even it's function right so the function +is + + align:start position:0% +is + + + align:start position:0% +is +even actually has a type and its type is + + align:start position:0% +even actually has a type and its type is + + + align:start position:0% +even actually has a type and its type is +a function in Python so functions are + + align:start position:0% +a function in Python so functions are + + + align:start position:0% +a function in Python so functions are +basically just objects just like an + + align:start position:0% +basically just objects just like an + + + align:start position:0% +basically just objects just like an +integer is an object a Boolean is an + + align:start position:0% +integer is an object a Boolean is an + + + align:start position:0% +integer is an object a Boolean is an +object a float is an object right a + + align:start position:0% +object a float is an object right a + + + align:start position:0% +object a float is an object right a +function it look it's an object it just + + align:start position:0% +function it look it's an object it just + + + align:start position:0% +function it look it's an object it just +looks different it has a bunch of code + + align:start position:0% +looks different it has a bunch of code + + + align:start position:0% +looks different it has a bunch of code +associated with it so if a function is + + align:start position:0% +associated with it so if a function is + + + align:start position:0% +associated with it so if a function is +an object what that means is we can uh + + align:start position:0% +an object what that means is we can uh + + + align:start position:0% +an object what that means is we can uh +use an assignment operator on a function + + align:start position:0% +use an assignment operator on a function + + + align:start position:0% +use an assignment operator on a function +name so we can have two names that + + align:start position:0% +name so we can have two names that + + + align:start position:0% +name so we can have two names that +functions that point to the same + + align:start position:0% +functions that point to the same + + + align:start position:0% +functions that point to the same +function code we can use a function as + + align:start position:0% +function code we can use a function as + + + align:start position:0% +function code we can use a function as +an argument to another function like a + + align:start position:0% +an argument to another function like a + + + align:start position:0% +an argument to another function like a +parameter to a function or we can return + + align:start position:0% +parameter to a function or we can return + + + align:start position:0% +parameter to a function or we can return +a function from another function + + align:start position:0% +a function from another function + + + align:start position:0% +a function from another function +okay so here's an + + align:start position:0% +okay so here's an + + + align:start position:0% +okay so here's an +example uh pretend that this is our uh + + align:start position:0% +example uh pretend that this is our uh + + + align:start position:0% +example uh pretend that this is our uh +code file we've got uh the memory the + + align:start position:0% +code file we've got uh the memory the + + + align:start position:0% +code file we've got uh the memory the +first line of code here the definition + + align:start position:0% +first line of code here the definition + + + align:start position:0% +first line of code here the definition +basically creates this function object + + align:start position:0% +basically creates this function object + + + align:start position:0% +basically creates this function object +for me in memory it's kind of like a + + align:start position:0% +for me in memory it's kind of like a + + + align:start position:0% +for me in memory it's kind of like a +variable right iscore even is the name + + align:start position:0% +variable right iscore even is the name + + + align:start position:0% +variable right iscore even is the name +of this function object and this + + align:start position:0% +of this function object and this + + + align:start position:0% +of this function object and this +variable is bound to my function object + + align:start position:0% +variable is bound to my function object + + + align:start position:0% +variable is bound to my function object +with some code associated with it right + + align:start position:0% +with some code associated with it right + + + align:start position:0% +with some code associated with it right +so you think of the function as just an + + align:start position:0% +so you think of the function as just an + + + align:start position:0% +so you think of the function as just an +object + + align:start position:0% +object + + + align:start position:0% +object +similarly right when we write R is equal + + align:start position:0% +similarly right when we write R is equal + + + align:start position:0% +similarly right when we write R is equal +to two I think of that as the same thing + + align:start position:0% +to two I think of that as the same thing + + + align:start position:0% +to two I think of that as the same thing +right R is the name and I've got an + + align:start position:0% +right R is the name and I've got an + + + align:start position:0% +right R is the name and I've got an +integer object whose values to that's + + align:start position:0% +integer object whose values to that's + + + align:start position:0% +integer object whose values to that's +exactly what happens when we create a + + align:start position:0% +exactly what happens when we create a + + + align:start position:0% +exactly what happens when we create a +function definition right similarly Pi + + align:start position:0% +function definition right similarly Pi + + + align:start position:0% +function definition right similarly Pi +is equal to 22 over 7 right Pi is the + + align:start position:0% +is equal to 22 over 7 right Pi is the + + + align:start position:0% +is equal to 22 over 7 right Pi is the +name associated with a float object + + align:start position:0% +name associated with a float object + + + align:start position:0% +name associated with a float object +that's has that + + align:start position:0% +that's has that + + + align:start position:0% +that's has that +value so what we can do right now that + + align:start position:0% +value so what we can do right now that + + + align:start position:0% +value so what we can do right now that +we've established that a function is + + align:start position:0% +we've established that a function is + + + align:start position:0% +we've established that a function is +basically an object with a name we can + + align:start position:0% +basically an object with a name we can + + + align:start position:0% +basically an object with a name we can +say a line like this my funk equals to + + align:start position:0% +say a line like this my funk equals to + + + align:start position:0% +say a line like this my funk equals to +is + + align:start position:0% +is + + + align:start position:0% +is +even the right hand side here is just + + align:start position:0% +even the right hand side here is just + + + align:start position:0% +even the right hand side here is just +the name of my + + align:start position:0% +the name of my + + + align:start position:0% +the name of my +function it's not a function call right + + align:start position:0% +function it's not a function call right + + + align:start position:0% +function it's not a function call right +notice there's no parentheses after is + + align:start position:0% +notice there's no parentheses after is + + + align:start position:0% +notice there's no parentheses after is +even there's no parameter none of that + + align:start position:0% +even there's no parameter none of that + + + align:start position:0% +even there's no parameter none of that +it's literally the name of my + + align:start position:0% +it's literally the name of my + + + align:start position:0% +it's literally the name of my +function so inside memory what I've + + align:start position:0% +function so inside memory what I've + + + align:start position:0% +function so inside memory what I've +ended up doing is I have two uh oops I + + align:start position:0% +ended up doing is I have two uh oops I + + + align:start position:0% +ended up doing is I have two uh oops I +have two names my funk and is even that + + align:start position:0% +have two names my funk and is even that + + + align:start position:0% +have two names my funk and is even that +both point to the exact same function + + align:start position:0% +both point to the exact same function + + + align:start position:0% +both point to the exact same function +object so that means that that function + + align:start position:0% +object so that means that that function + + + align:start position:0% +object so that means that that function +object so this is even + + align:start position:0% +object so this is even + + + align:start position:0% +object so this is even +function can be referenced by both of + + align:start position:0% +function can be referenced by both of + + + align:start position:0% +function can be referenced by both of +these names so on the next two lines + + align:start position:0% +these names so on the next two lines + + + align:start position:0% +these names so on the next two lines +here a equals this and b equals this I'm + + align:start position:0% +here a equals this and b equals this I'm + + + align:start position:0% +here a equals this and b equals this I'm +running the same code just referenced by + + align:start position:0% +running the same code just referenced by + + + align:start position:0% +running the same code just referenced by +different names right so then a is going + + align:start position:0% +different names right so then a is going + + + align:start position:0% +different names right so then a is going +to be bound to false and B is bound to + + align:start position:0% +to be bound to false and B is bound to + + + align:start position:0% +to be bound to false and B is bound to +true because I'm I'm accessing the same + + align:start position:0% +true because I'm I'm accessing the same + + + align:start position:0% +true because I'm I'm accessing the same +code fundamentally by different names + + align:start position:0% +code fundamentally by different names + + + align:start position:0% +code fundamentally by different names +does that make sense yes awesome so + + align:start position:0% +does that make sense yes awesome so + + + align:start position:0% +does that make sense yes awesome so +everything in Python is an object + + align:start position:0% +everything in Python is an object + + + align:start position:0% +everything in Python is an object +including functions it's strange to + + align:start position:0% +including functions it's strange to + + + align:start position:0% +including functions it's strange to +think but there you have it so let's + + align:start position:0% +think but there you have it so let's + + + align:start position:0% +think but there you have it so let's +look at this + + align:start position:0% +look at this + + + align:start position:0% +look at this +code I've got three function definitions + + align:start position:0% +code I've got three function definitions + + + align:start position:0% +code I've got three function definitions +and only one function + + align:start position:0% + + + + align:start position:0% + +call what are the functions uh function + + align:start position:0% +call what are the functions uh function + + + align:start position:0% +call what are the functions uh function +definitions one I have named Cal it + + align:start position:0% +definitions one I have named Cal it + + + align:start position:0% +definitions one I have named Cal it +takes in three parameters one I have ADD + + align:start position:0% +takes in three parameters one I have ADD + + + align:start position:0% +takes in three parameters one I have ADD +it takes in two parameters and one I + + align:start position:0% +it takes in two parameters and one I + + + align:start position:0% +it takes in two parameters and one I +have div it takes in two + + align:start position:0% +have div it takes in two + + + align:start position:0% +have div it takes in two +parameters + + align:start position:0% +parameters + + + align:start position:0% +parameters +add does something pretty simple div has + + align:start position:0% +add does something pretty simple div has + + + align:start position:0% +add does something pretty simple div has +maybe a print statement but also does + + align:start position:0% +maybe a print statement but also does + + + align:start position:0% +maybe a print statement but also does +something pretty simple Cal is the one + + align:start position:0% +something pretty simple Cal is the one + + + align:start position:0% +something pretty simple Cal is the one +that's really strange right because it + + align:start position:0% +that's really strange right because it + + + align:start position:0% +that's really strange right because it +takes in these three parameters but + + align:start position:0% +takes in these three parameters but + + + align:start position:0% +takes in these three parameters but +what's the thing it's doing in here it's + + align:start position:0% +what's the thing it's doing in here it's + + + align:start position:0% +what's the thing it's doing in here it's +kind of treating one of the parameters + + align:start position:0% +kind of treating one of the parameters + + + align:start position:0% +kind of treating one of the parameters +op operation as a + + align:start position:0% + + + + align:start position:0% + +function okay that's what stranger about + + align:start position:0% +function okay that's what stranger about + + + align:start position:0% +function okay that's what stranger about +Cals and let's Trace through the code to + + align:start position:0% +Cals and let's Trace through the code to + + + align:start position:0% +Cals and let's Trace through the code to +see exactly what that means for us so + + align:start position:0% +see exactly what that means for us so + + + align:start position:0% +see exactly what that means for us so +when I first run my program I have three + + align:start position:0% +when I first run my program I have three + + + align:start position:0% +when I first run my program I have three +function definitions so I'm creating + + align:start position:0% +function definitions so I'm creating + + + align:start position:0% +function definitions so I'm creating +three function objects inside memory + + align:start position:0% +three function objects inside memory + + + align:start position:0% +three function objects inside memory +calc a function object that has some + + align:start position:0% +calc a function object that has some + + + align:start position:0% +calc a function object that has some +code add a function object that has some + + align:start position:0% +code add a function object that has some + + + align:start position:0% +code add a function object that has some +code and div a function object that has + + align:start position:0% +code and div a function object that has + + + align:start position:0% +code and div a function object that has +some code and then we get to the good + + align:start position:0% +some code and then we get to the good + + + align:start position:0% +some code and then we get to the good +stuff re equals the function + + align:start position:0% +stuff re equals the function + + + align:start position:0% +stuff re equals the function +call so re is going to be a variable + + align:start position:0% +call so re is going to be a variable + + + align:start position:0% +call so re is going to be a variable +that's going to have a + + align:start position:0% +that's going to have a + + + align:start position:0% +that's going to have a +value what value we need to figure that + + align:start position:0% +value what value we need to figure that + + + align:start position:0% +value what value we need to figure that +out Cal is a function call every time we + + align:start position:0% +out Cal is a function call every time we + + + align:start position:0% +out Cal is a function call every time we +have a function call we need to create a + + align:start position:0% +have a function call we need to create a + + + align:start position:0% +have a function call we need to create a +new environment so now we are creating + + align:start position:0% +new environment so now we are creating + + + align:start position:0% +new environment so now we are creating +our calc + + align:start position:0% +our calc + + + align:start position:0% +our calc +environment so we've put aside the main + + align:start position:0% +environment so we've put aside the main + + + align:start position:0% +environment so we've put aside the main +program scope for now and we're focusing + + align:start position:0% +program scope for now and we're focusing + + + align:start position:0% +program scope for now and we're focusing +on what Cal is going to + + align:start position:0% +on what Cal is going to + + + align:start position:0% +on what Cal is going to +do first thing we need to do is take + + align:start position:0% +do first thing we need to do is take + + + align:start position:0% +do first thing we need to do is take +every single one of our parameters and + + align:start position:0% +every single one of our parameters and + + + align:start position:0% +every single one of our parameters and +map it to the actual parameters right so + + align:start position:0% +map it to the actual parameters right so + + + align:start position:0% +map it to the actual parameters right so +the first parameter is op it gets mapped + + align:start position:0% + + + + align:start position:0% + +to + + align:start position:0% +to + + + align:start position:0% +to +add the next parameter is X gets mapped + + align:start position:0% +add the next parameter is X gets mapped + + + align:start position:0% +add the next parameter is X gets mapped +to two the last parameter is y gets + + align:start position:0% +to two the last parameter is y gets + + + align:start position:0% +to two the last parameter is y gets +mapped to three is everyone okay so far + + align:start position:0% +mapped to three is everyone okay so far + + + align:start position:0% +mapped to three is everyone okay so far +yes okay I've literally just matched + + align:start position:0% +yes okay I've literally just matched + + + align:start position:0% +yes okay I've literally just matched +names of formal parameter to actual + + align:start position:0% +names of formal parameter to actual + + + align:start position:0% +names of formal parameter to actual +parameter okay so now we finished + + align:start position:0% +parameter okay so now we finished + + + align:start position:0% +parameter okay so now we finished +mapping the for the parameters next we + + align:start position:0% +mapping the for the parameters next we + + + align:start position:0% +mapping the for the parameters next we +get to run the body of the function + + align:start position:0% +get to run the body of the function + + + align:start position:0% +get to run the body of the function +return what is + + align:start position:0% +return what is + + + align:start position:0% +return what is +this let's replace op X and Y with the + + align:start position:0% +this let's replace op X and Y with the + + + align:start position:0% +this let's replace op X and Y with the +actual values this basically becomes + + align:start position:0% +actual values this basically becomes + + + align:start position:0% +actual values this basically becomes +return a function call add 2 comma 3 + + align:start position:0% +return a function call add 2 comma 3 + + + align:start position:0% +return a function call add 2 comma 3 +I've just replaced the names that's it + + align:start position:0% +I've just replaced the names that's it + + + align:start position:0% +I've just replaced the names that's it +what's add 2 comma + + align:start position:0% + + + + align:start position:0% + +3 it's another function call right so + + align:start position:0% +3 it's another function call right so + + + align:start position:0% +3 it's another function call right so +calc is going to have to be put on hold + + align:start position:0% +calc is going to have to be put on hold + + + align:start position:0% +calc is going to have to be put on hold +because I have to figure out what ad is + + align:start position:0% +because I have to figure out what ad is + + + align:start position:0% +because I have to figure out what ad is +going to + + align:start position:0% + + + + align:start position:0% + +return okay so what's ad going to return + + align:start position:0% +return okay so what's ad going to return + + + align:start position:0% +return okay so what's ad going to return +for me well add 2 comma 3 is what I'm + + align:start position:0% +for me well add 2 comma 3 is what I'm + + + align:start position:0% +for me well add 2 comma 3 is what I'm +trying to figure out so I'm going to map + + align:start position:0% +trying to figure out so I'm going to map + + + align:start position:0% +trying to figure out so I'm going to map +a to 2 B to three it's going to do five + + align:start position:0% +a to 2 B to three it's going to do five + + + align:start position:0% +a to 2 B to three it's going to do five +as the uh return so it returns five to + + align:start position:0% +as the uh return so it returns five to + + + align:start position:0% +as the uh return so it returns five to +whoever called it and whoever called it + + align:start position:0% +whoever called it and whoever called it + + + align:start position:0% +whoever called it and whoever called it +was Cal right here so this expression + + align:start position:0% +was Cal right here so this expression + + + align:start position:0% +was Cal right here so this expression +here op X comma Y which was add 2 comma + + align:start position:0% +here op X comma Y which was add 2 comma + + + align:start position:0% +here op X comma Y which was add 2 comma +3 is replaced placed with + + align:start position:0% +3 is replaced placed with + + + align:start position:0% +3 is replaced placed with +five everyone okay so far awesome okay + + align:start position:0% +five everyone okay so far awesome okay + + + align:start position:0% +five everyone okay so far awesome okay +and then Cal can now finish right notice + + align:start position:0% +and then Cal can now finish right notice + + + align:start position:0% +and then Cal can now finish right notice +ad finished its job so it went away now + + align:start position:0% +ad finished its job so it went away now + + + align:start position:0% +ad finished its job so it went away now +Cal can finally return its value so it + + align:start position:0% +Cal can finally return its value so it + + + align:start position:0% +Cal can finally return its value so it +can finish as well so this one will + + align:start position:0% +can finish as well so this one will + + + align:start position:0% +can finish as well so this one will +return + + align:start position:0% +return + + + align:start position:0% +return +five to whoever called it which was the + + align:start position:0% +five to whoever called it which was the + + + align:start position:0% +five to whoever called it which was the +main program and finally Cal has + + align:start position:0% +main program and finally Cal has + + + align:start position:0% +main program and finally Cal has +finished its job and it returned + + align:start position:0% + + + + align:start position:0% + +five so step by step we just kind of + + align:start position:0% +five so step by step we just kind of + + + align:start position:0% +five so step by step we just kind of +Trace through the code + + align:start position:0% +Trace through the code + + + align:start position:0% +Trace through the code +you know functions out to in and + + align:start position:0% +you know functions out to in and + + + align:start position:0% +you know functions out to in and +replacing variables wherever needed so + + align:start position:0% +replacing variables wherever needed so + + + align:start position:0% +replacing variables wherever needed so +it's your turn tell me what's the value + + align:start position:0% +it's your turn tell me what's the value + + + align:start position:0% +it's your turn tell me what's the value +of Rez given this uh function called a + + align:start position:0% +of Rez given this uh function called a + + + align:start position:0% +of Rez given this uh function called a +cal and what's going to get + + align:start position:0% + + + + align:start position:0% + +printed so we can even write our + + align:start position:0% +printed so we can even write our + + + align:start position:0% +printed so we can even write our +functions so in the main + + align:start position:0% +functions so in the main + + + align:start position:0% +functions so in the main +program what do I have + + align:start position:0% + + + + align:start position:0% + +yep Cal and div are my + + align:start position:0% +yep Cal and div are my + + + align:start position:0% +yep Cal and div are my +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +functions that's it which + + align:start position:0% +functions that's it which + + + align:start position:0% +functions that's it which +one yeah res will be the the result yep + + align:start position:0% +one yeah res will be the the result yep + + + align:start position:0% +one yeah res will be the the result yep +and there res we will have a question + + align:start position:0% +and there res we will have a question + + + align:start position:0% +and there res we will have a question +mark because we don't know what it is + + align:start position:0% +mark because we don't know what it is + + + align:start position:0% +mark because we don't know what it is +yet and what's the first thing I need to + + align:start position:0% + + + + align:start position:0% + +do yeah make a new scope + + align:start position:0% +do yeah make a new scope + + + align:start position:0% +do yeah make a new scope +exactly so that's the scope of calc and + + align:start position:0% +exactly so that's the scope of calc and + + + align:start position:0% +exactly so that's the scope of calc and +we're going to map + + align:start position:0% +we're going to map + + + align:start position:0% +we're going to map +op to + + align:start position:0% +op to + + + align:start position:0% +op to +div what do I have X and Y two two and + + align:start position:0% +div what do I have X and Y two two and + + + align:start position:0% +div what do I have X and Y two two and +zero thank + + align:start position:0% + + + + align:start position:0% + +you so what's op going to + + align:start position:0% + + + + align:start position:0% + +do yes exactly we make another scope for + + align:start position:0% +do yes exactly we make another scope for + + + align:start position:0% +do yes exactly we make another scope for +div a is two and B is + + align:start position:0% +div a is two and B is + + + align:start position:0% +div a is two and B is +zero + + align:start position:0% +zero + + + align:start position:0% +zero +so we're kind of two Scopes + + align:start position:0% +so we're kind of two Scopes + + + align:start position:0% +so we're kind of two Scopes +deep what's div G to + + align:start position:0% + + + + align:start position:0% + +do yep so div prints out the thing denom + + align:start position:0% +do yep so div prints out the thing denom + + + align:start position:0% +do yep so div prints out the thing denom +was zero and what's div + + align:start position:0% +was zero and what's div + + + align:start position:0% +was zero and what's div +returning none perfect so div returns + + align:start position:0% +returning none perfect so div returns + + + align:start position:0% +returning none perfect so div returns +none here to + + align:start position:0% + + + + align:start position:0% + +Cal and then div is + + align:start position:0% +Cal and then div is + + + align:start position:0% +Cal and then div is +gone and then none gets returned from + + align:start position:0% +gone and then none gets returned from + + + align:start position:0% +gone and then none gets returned from +from Cal + + align:start position:0% + + + + align:start position:0% + +here and then Cal is gone and all I'm + + align:start position:0% +here and then Cal is gone and all I'm + + + align:start position:0% +here and then Cal is gone and all I'm +ref left with Is Res + + align:start position:0% +ref left with Is Res + + + align:start position:0% +ref left with Is Res +equals none exactly the return of + + align:start position:0% + + + + align:start position:0% + +Cal one more example uh showing + + align:start position:0% +Cal one more example uh showing + + + align:start position:0% +Cal one more example uh showing +scope I'm just kind of showcasing these + + align:start position:0% +scope I'm just kind of showcasing these + + + align:start position:0% +scope I'm just kind of showcasing these +uh sort of the same idea so I've got + + align:start position:0% +uh sort of the same idea so I've got + + + align:start position:0% +uh sort of the same idea so I've got +three functions here Funk a funk B and + + align:start position:0% +three functions here Funk a funk B and + + + align:start position:0% +three functions here Funk a funk B and +Funk C Funk a takes in you can see no + + align:start position:0% +Funk C Funk a takes in you can see no + + + align:start position:0% +Funk C Funk a takes in you can see no +parameters Funk B takes in one parameter + + align:start position:0% +parameters Funk B takes in one parameter + + + align:start position:0% +parameters Funk B takes in one parameter +Funk C takes in two parameters and if we + + align:start position:0% +Funk C takes in two parameters and if we + + + align:start position:0% +Funk C takes in two parameters and if we +scan the code we see that one of them is + + align:start position:0% +scan the code we see that one of them is + + + align:start position:0% +scan the code we see that one of them is +weirdly doing something so it's actually + + align:start position:0% +weirdly doing something so it's actually + + + align:start position:0% +weirdly doing something so it's actually +going to be a function right because you + + align:start position:0% +going to be a function right because you + + + align:start position:0% +going to be a function right because you +see we're calling it like a function + + align:start position:0% +see we're calling it like a function + + + align:start position:0% +see we're calling it like a function +inside here so we know f is going to + + align:start position:0% +inside here so we know f is going to + + + align:start position:0% +inside here so we know f is going to +have to be a + + align:start position:0% +have to be a + + + align:start position:0% +have to be a +function so if we run this program first + + align:start position:0% +function so if we run this program first + + + align:start position:0% +function so if we run this program first +three function definitions basically put + + align:start position:0% +three function definitions basically put + + + align:start position:0% +three function definitions basically put +some code for us in the memory when we + + align:start position:0% +some code for us in the memory when we + + + align:start position:0% +some code for us in the memory when we +make uh Funk call sorry Funk a call this + + align:start position:0% +make uh Funk call sorry Funk a call this + + + align:start position:0% +make uh Funk call sorry Funk a call this +creates a new + + align:start position:0% +creates a new + + + align:start position:0% +creates a new +scope a has no param or Funk a has no + + align:start position:0% +scope a has no param or Funk a has no + + + align:start position:0% +scope a has no param or Funk a has no +parameter so there's nothing to bind all + + align:start position:0% +parameter so there's nothing to bind all + + + align:start position:0% +parameter so there's nothing to bind all +this function is going to do is print + + align:start position:0% +this function is going to do is print + + + align:start position:0% +this function is going to do is print +inside Funk a and then return + + align:start position:0% +inside Funk a and then return + + + align:start position:0% +inside Funk a and then return +none right so that whole thing is going + + align:start position:0% +none right so that whole thing is going + + + align:start position:0% +none right so that whole thing is going +to print + + align:start position:0% +to print + + + align:start position:0% +to print +none next Funk + + align:start position:0% +none next Funk + + + align:start position:0% +none next Funk +B is going to uh be another function + + align:start position:0% +B is going to uh be another function + + + align:start position:0% +B is going to uh be another function +call right here so it creates a function + + align:start position:0% +call right here so it creates a function + + + align:start position:0% +call right here so it creates a function +scope right here we m M the formal + + align:start position:0% +scope right here we m M the formal + + + align:start position:0% +scope right here we m M the formal +parameter y to + + align:start position:0% +parameter y to + + + align:start position:0% +parameter y to +two and then we finished mapping all the + + align:start position:0% +two and then we finished mapping all the + + + align:start position:0% +two and then we finished mapping all the +parameters and what we need to do next + + align:start position:0% +parameters and what we need to do next + + + align:start position:0% +parameters and what we need to do next +is do the body so we print inside Funk B + + align:start position:0% +is do the body so we print inside Funk B + + + align:start position:0% +is do the body so we print inside Funk B +and it just Returns the value you passed + + align:start position:0% +and it just Returns the value you passed + + + align:start position:0% +and it just Returns the value you passed +into it so not a very smart or + + align:start position:0% +into it so not a very smart or + + + align:start position:0% +into it so not a very smart or +interesting function so it prints that + + align:start position:0% +interesting function so it prints that + + + align:start position:0% +interesting function so it prints that +and returns two back to whoever called + + align:start position:0% +and returns two back to whoever called + + + align:start position:0% +and returns two back to whoever called +it whoever called it was here so this + + align:start position:0% +it whoever called it was here so this + + + align:start position:0% +it whoever called it was here so this +print statement becomes print 5 + 2 the + + align:start position:0% +print statement becomes print 5 + 2 the + + + align:start position:0% +print statement becomes print 5 + 2 the +return so that's going to print stuff + + align:start position:0% +return so that's going to print stuff + + + align:start position:0% +return so that's going to print stuff +into the console + + align:start position:0% +into the console + + + align:start position:0% +into the console +and lastly the interesting one is going + + align:start position:0% +and lastly the interesting one is going + + + align:start position:0% +and lastly the interesting one is going +to be Funk C so Funk C notice I'm + + align:start position:0% +to be Funk C so Funk C notice I'm + + + align:start position:0% +to be Funk C so Funk C notice I'm +calling it with an actual function I + + align:start position:0% +calling it with an actual function I + + + align:start position:0% +calling it with an actual function I +have in hand Funk B right one of these + + align:start position:0% +have in hand Funk B right one of these + + + align:start position:0% +have in hand Funk B right one of these +that I've defined + + align:start position:0% +that I've defined + + + align:start position:0% +that I've defined +here so Funk C is a function call so + + align:start position:0% +here so Funk C is a function call so + + + align:start position:0% +here so Funk C is a function call so +there's my scope I am mapping formal + + align:start position:0% +there's my scope I am mapping formal + + + align:start position:0% +there's my scope I am mapping formal +parameter F to Funk B and Z to three so + + align:start position:0% +parameter F to Funk B and Z to three so + + + align:start position:0% +parameter F to Funk B and Z to three so +just mapping one one by + + align:start position:0% +just mapping one one by + + + align:start position:0% +just mapping one one by +one and then I'm doing the body of funk + + align:start position:0% +one and then I'm doing the body of funk + + + align:start position:0% +one and then I'm doing the body of funk +C so the body says now print this and + + align:start position:0% +C so the body says now print this and + + + align:start position:0% +C so the body says now print this and +return this so we print the + + align:start position:0% +return this so we print the + + + align:start position:0% +return this so we print the +statement and then the return basically + + align:start position:0% +statement and then the return basically + + + align:start position:0% +statement and then the return basically +says well what's F function called FZ we + + align:start position:0% +says well what's F function called FZ we + + + align:start position:0% +says well what's F function called FZ we +have to figure out what the actual + + align:start position:0% +have to figure out what the actual + + + align:start position:0% +have to figure out what the actual +values + + align:start position:0% +values + + + align:start position:0% +values +are and it's Funk B parentheses + + align:start position:0% +are and it's Funk B parentheses + + + align:start position:0% +are and it's Funk B parentheses +3 so that's another function call which + + align:start position:0% +3 so that's another function call which + + + align:start position:0% +3 so that's another function call which +means another function scope again not a + + align:start position:0% +means another function scope again not a + + + align:start position:0% +means another function scope again not a +very smart or interesting function this + + align:start position:0% +very smart or interesting function this + + + align:start position:0% +very smart or interesting function this +funk B it just takes in the three prints + + align:start position:0% +funk B it just takes in the three prints + + + align:start position:0% +funk B it just takes in the three prints +inside Funk B and it Returns the three + + align:start position:0% +inside Funk B and it Returns the three + + + align:start position:0% +inside Funk B and it Returns the three +back to whoever called it so that fun + + align:start position:0% +back to whoever called it so that fun + + + align:start position:0% +back to whoever called it so that fun +that function is done and then the funk + + align:start position:0% +that function is done and then the funk + + + align:start position:0% +that function is done and then the funk +C can terminate and return three to + + align:start position:0% +C can terminate and return three to + + + align:start position:0% +C can terminate and return three to +whoever called it which was out + + align:start position:0% + + + + align:start position:0% + +here and notice as soon as a function + + align:start position:0% +here and notice as soon as a function + + + align:start position:0% +here and notice as soon as a function +call terminates and does a return it + + align:start position:0% +call terminates and does a return it + + + align:start position:0% +call terminates and does a return it +immediately it you know all of its + + align:start position:0% +immediately it you know all of its + + + align:start position:0% +immediately it you know all of its +variables everything that got created + + align:start position:0% +variables everything that got created + + + align:start position:0% +variables everything that got created +inside that environment uh go away they + + align:start position:0% +inside that environment uh go away they + + + align:start position:0% +inside that environment uh go away they +get wiped + + align:start position:0% + + + + align:start position:0% + +out okay give you about a minute to try + + align:start position:0% +out okay give you about a minute to try + + + align:start position:0% +out okay give you about a minute to try +this so write a function that meets the + + align:start position:0% +this so write a function that meets the + + + align:start position:0% +this so write a function that meets the +following specifications so I have a + + align:start position:0% +following specifications so I have a + + + align:start position:0% +following specifications so I have a +function named + + align:start position:0% +function named + + + align:start position:0% +function named +apply criteria is a formal parameter + + align:start position:0% +apply criteria is a formal parameter + + + align:start position:0% +apply criteria is a formal parameter +right so at some point you're going to + + align:start position:0% +right so at some point you're going to + + + align:start position:0% +right so at some point you're going to +have a function that does this it takes + + align:start position:0% +have a function that does this it takes + + + align:start position:0% +have a function that does this it takes +an inte a number an integer and returns + + align:start position:0% +an inte a number an integer and returns + + + align:start position:0% +an inte a number an integer and returns +a Boolean right so however a function + + align:start position:0% +a Boolean right so however a function + + + align:start position:0% +a Boolean right so however a function +does that that's what's going to be + + align:start position:0% +does that that's what's going to be + + + align:start position:0% +does that that's what's going to be +passed in and then and is an integer and + + align:start position:0% +passed in and then and is an integer and + + + align:start position:0% +passed in and then and is an integer and +what I want you to do is tell me how + + align:start position:0% +what I want you to do is tell me how + + + align:start position:0% +what I want you to do is tell me how +many numbers from 0 to n match criteria + + align:start position:0% +many numbers from 0 to n match criteria + + + align:start position:0% +many numbers from 0 to n match criteria +so when I apply the function criteria to + + align:start position:0% +so when I apply the function criteria to + + + align:start position:0% +so when I apply the function criteria to +numbers 0 through n how many of those + + align:start position:0% +numbers 0 through n how many of those + + + align:start position:0% +numbers 0 through n how many of those +actually return true on that function so + + align:start position:0% +actually return true on that function so + + + align:start position:0% +actually return true on that function so +just to show you something uh you know + + align:start position:0% +just to show you something uh you know + + + align:start position:0% +just to show you something uh you know +what this means concretely here's my + + align:start position:0% +what this means concretely here's my + + + align:start position:0% +what this means concretely here's my +function + + align:start position:0% +function + + + align:start position:0% +function +apply here's a function that I could + + align:start position:0% +apply here's a function that I could + + + align:start position:0% +apply here's a function that I could +call the apply with is even sorry I lied + + align:start position:0% +call the apply with is even sorry I lied + + + align:start position:0% +call the apply with is even sorry I lied +I guess we are seeing is even a few more + + align:start position:0% +I guess we are seeing is even a few more + + + align:start position:0% +I guess we are seeing is even a few more +times in this lecture um so here's a + + align:start position:0% +times in this lecture um so here's a + + + align:start position:0% +times in this lecture um so here's a +function is even and basically I run + + align:start position:0% +function is even and basically I run + + + align:start position:0% +function is even and basically I run +apply by saying I want to run function + + align:start position:0% +apply by saying I want to run function + + + align:start position:0% +apply by saying I want to run function +apply with the name is even right so + + align:start position:0% +apply with the name is even right so + + + align:start position:0% +apply with the name is even right so +here I'm mapping name to numbers 0 + + align:start position:0% +here I'm mapping name to numbers 0 + + + align:start position:0% +here I'm mapping name to numbers 0 +through + + align:start position:0% +through + + + align:start position:0% +through +10 so I'll give you about a minute to to + + align:start position:0% +10 so I'll give you about a minute to to + + + align:start position:0% +10 so I'll give you about a minute to to +try it out and then I can write it just + + align:start position:0% +try it out and then I can write it just + + + align:start position:0% +try it out and then I can write it just +so we have some uh so we finish on + + align:start position:0% +so we have some uh so we finish on + + + align:start position:0% +so we have some uh so we finish on +time does anyone have a + + align:start position:0% + + + + align:start position:0% + +start so we know we want to touch each + + align:start position:0% +start so we know we want to touch each + + + align:start position:0% +start so we know we want to touch each +number zero through through n to see + + align:start position:0% +number zero through through n to see + + + align:start position:0% +number zero through through n to see +whether this criteria applies to them + + align:start position:0% +whether this criteria applies to them + + + align:start position:0% +whether this criteria applies to them +right so what's the start to get that + + align:start position:0% +right so what's the start to get that + + + align:start position:0% +right so what's the start to get that +going + + align:start position:0% + + + + align:start position:0% + +yeah for ION range n + one because we + + align:start position:0% +yeah for ION range n + one because we + + + align:start position:0% +yeah for ION range n + one because we +want to include + + align:start position:0% +want to include + + + align:start position:0% +want to include +n how do we apply the function criteria + + align:start position:0% +n how do we apply the function criteria + + + align:start position:0% +n how do we apply the function criteria +to each one of these + + align:start position:0% + + + + align:start position:0% + +values yeah exactly we just say criteria + + align:start position:0% +values yeah exactly we just say criteria + + + align:start position:0% +values yeah exactly we just say criteria +and this name will be replaced with + + align:start position:0% +and this name will be replaced with + + + align:start position:0% +and this name will be replaced with +whatever function we're going to call + + align:start position:0% +whatever function we're going to call + + + align:start position:0% +whatever function we're going to call +apply with + + align:start position:0% +apply with + + + align:start position:0% +apply with +I right and this criteria I will + + align:start position:0% +I right and this criteria I will + + + align:start position:0% +I right and this criteria I will +basically be the return of criteria what + + align:start position:0% +basically be the return of criteria what + + + align:start position:0% +basically be the return of criteria what +did I say criteria returns it takes in a + + align:start position:0% +did I say criteria returns it takes in a + + + align:start position:0% +did I say criteria returns it takes in a +number and + + align:start position:0% +number and + + + align:start position:0% +number and +returns a + + align:start position:0% +returns a + + + align:start position:0% +returns a +Boolean so we know that this is a + + align:start position:0% +Boolean so we know that this is a + + + align:start position:0% +Boolean so we know that this is a +Boolean what do I want to do with this + + align:start position:0% + + + + align:start position:0% + +Boolean if it's true I want to count it + + align:start position:0% +Boolean if it's true I want to count it + + + align:start position:0% +Boolean if it's true I want to count it +if it's not I don't so if criteria + + align:start position:0% +if it's not I don't so if criteria + + + align:start position:0% +if it's not I don't so if criteria +I count plus equals + + align:start position:0% +I count plus equals + + + align:start position:0% +I count plus equals +1 right put this up here and let's + + align:start position:0% +1 right put this up here and let's + + + align:start position:0% +1 right put this up here and let's +remember to uh initialize our + + align:start position:0% + + + + align:start position:0% + +count and then that's it right if it's + + align:start position:0% +count and then that's it right if it's + + + align:start position:0% +count and then that's it right if it's +if it doesn't match then I don't care + + align:start position:0% +if it doesn't match then I don't care + + + align:start position:0% +if it doesn't match then I don't care +about doing anything with it so then we + + align:start position:0% +about doing anything with it so then we + + + align:start position:0% +about doing anything with it so then we +just return + + align:start position:0% +just return + + + align:start position:0% +just return +count so notice I'm using my function + + align:start position:0% +count so notice I'm using my function + + + align:start position:0% +count so notice I'm using my function +here that's just a parameter kind of + + align:start position:0% +here that's just a parameter kind of + + + align:start position:0% +here that's just a parameter kind of +like a place holder for any other + + align:start position:0% +like a place holder for any other + + + align:start position:0% +like a place holder for any other +function so this is even function when + + align:start position:0% +function so this is even function when + + + align:start position:0% +function so this is even function when +it's a parameter to + + align:start position:0% + + + + align:start position:0% + +apply will tell me six right 0 2 4 6 8 + + align:start position:0% +apply will tell me six right 0 2 4 6 8 + + + align:start position:0% +apply will tell me six right 0 2 4 6 8 +10 that's that's six values that match + + align:start position:0% +10 that's that's six values that match + + + align:start position:0% +10 that's that's six values that match +this criteria and what's cool is that I + + align:start position:0% +this criteria and what's cool is that I + + + align:start position:0% +this criteria and what's cool is that I +can actually create any function so if I + + align:start position:0% +can actually create any function so if I + + + align:start position:0% +can actually create any function so if I +want a function that's called is Five + + align:start position:0% +want a function that's called is Five + + + align:start position:0% +want a function that's called is Five +For example right it takes in a number + + align:start position:0% +For example right it takes in a number + + + align:start position:0% +For example right it takes in a number +and returns true if that number is equal + + align:start position:0% +and returns true if that number is equal + + + align:start position:0% +and returns true if that number is equal +to five right + + align:start position:0% +to five right + + + align:start position:0% +to five right +it's still a function that takes in an + + align:start position:0% +it's still a function that takes in an + + + align:start position:0% +it's still a function that takes in an +integer and returns a Boolean all I need + + align:start position:0% +integer and returns a Boolean all I need + + + align:start position:0% +integer and returns a Boolean all I need +to do then is run this apply with the + + align:start position:0% +to do then is run this apply with the + + + align:start position:0% +to do then is run this apply with the +function is + + align:start position:0% +function is + + + align:start position:0% +function is +five right so I just changed that here + + align:start position:0% +five right so I just changed that here + + + align:start position:0% +five right so I just changed that here +and then if I run it it should just give + + align:start position:0% +and then if I run it it should just give + + + align:start position:0% +and then if I run it it should just give +me one value right the five of course is + + align:start position:0% +me one value right the five of course is + + + align:start position:0% +me one value right the five of course is +one that + + align:start position:0% +one that + + + align:start position:0% +one that +matches this is five criteria between + + align:start position:0% +matches this is five criteria between + + + align:start position:0% +matches this is five criteria between +zero and + + align:start position:0% +zero and + + + align:start position:0% +zero and +10 yeah so that's basically it so we saw + + align:start position:0% +10 yeah so that's basically it so we saw + + + align:start position:0% +10 yeah so that's basically it so we saw +some uh uh function a lot more you can + + align:start position:0% +some uh uh function a lot more you can + + + align:start position:0% +some uh uh function a lot more you can +do with functions + + align:start position:0% +do with functions + + + align:start position:0% +do with functions +they're basically objects in Python so + + align:start position:0% +they're basically objects in Python so + + + align:start position:0% +they're basically objects in Python so +they can be manipulated just like you + + align:start position:0% +they can be manipulated just like you + + + align:start position:0% +they can be manipulated just like you +would any other object you can have them + + align:start position:0% +would any other object you can have them + + + align:start position:0% +would any other object you can have them +be parameters to a function you can have + + align:start position:0% +be parameters to a function you can have + + + align:start position:0% +be parameters to a function you can have +them be returned from a function uh you + + align:start position:0% +them be returned from a function uh you + + + align:start position:0% +them be returned from a function uh you +can assign another name to this function + + align:start position:0% +can assign another name to this function + + + align:start position:0% +can assign another name to this function +body things like that uh I showed you + + align:start position:0% +body things like that uh I showed you + + + align:start position:0% +body things like that uh I showed you +what to how to think about environments + + align:start position:0% +what to how to think about environments + + + align:start position:0% +what to how to think about environments +right so that the naming doesn't get + + align:start position:0% +right so that the naming doesn't get + + + align:start position:0% +right so that the naming doesn't get +confusing right as soon as a function + + align:start position:0% +confusing right as soon as a function + + + align:start position:0% +confusing right as soon as a function +call is made that means another + + align:start position:0% +call is made that means another + + + align:start position:0% +call is made that means another +environment is created so variables + + align:start position:0% +environment is created so variables + + + align:start position:0% +environment is created so variables +created within that environment have no + + align:start position:0% +created within that environment have no + + + align:start position:0% +created within that environment have no +influence on other variables created in + + align:start position:0% +influence on other variables created in + + + align:start position:0% +influence on other variables created in +other environments okay um and functions + + align:start position:0% +other environments okay um and functions + + + align:start position:0% +other environments okay um and functions +are very nice oh very nice way for us to + + align:start position:0% +are very nice oh very nice way for us to + + + align:start position:0% +are very nice oh very nice way for us to +write code that can be easily be built + + align:start position:0% +write code that can be easily be built + + + align:start position:0% +write code that can be easily be built +up on + + align:start position:0% +up on + + + align:start position:0% +up on +okay that's it thank + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/0jWwl0bt6aU.txt b/0jWwl0bt6aU.txt new file mode 100644 index 0000000000000000000000000000000000000000..a7d2cfabc5eb58964b75cf6b361d4f7dcd3b1598 --- /dev/null +++ b/0jWwl0bt6aU.txt @@ -0,0 +1,699 @@ +align:start position:0% + +let's now explore an example of a force + + align:start position:0% +let's now explore an example of a force + + + align:start position:0% +let's now explore an example of a force +in which the work done + + align:start position:0% +in which the work done + + + align:start position:0% +in which the work done +it is not path independent and the + + align:start position:0% +it is not path independent and the + + + align:start position:0% +it is not path independent and the +classic example is the friction force so + + align:start position:0% +classic example is the friction force so + + + align:start position:0% +classic example is the friction force so +let's consider the following setup + + align:start position:0% +let's consider the following setup + + + align:start position:0% +let's consider the following setup +suppose we have a horizontal surface + + align:start position:0% +suppose we have a horizontal surface + + + align:start position:0% +suppose we have a horizontal surface +with friction and we have an object and + + align:start position:0% +with friction and we have an object and + + + align:start position:0% +with friction and we have an object and +we're moving this object so let's choose + + align:start position:0% +we're moving this object so let's choose + + + align:start position:0% +we're moving this object so let's choose +an origin we'll call this plus X or I + + align:start position:0% +an origin we'll call this plus X or I + + + align:start position:0% +an origin we'll call this plus X or I +have Direction it's all going to be + + align:start position:0% +have Direction it's all going to be + + + align:start position:0% +have Direction it's all going to be +one-dimensional motion and we're going + + align:start position:0% +one-dimensional motion and we're going + + + align:start position:0% +one-dimensional motion and we're going +to move this object from an initial to a + + align:start position:0% +to move this object from an initial to a + + + align:start position:0% +to move this object from an initial to a +final state and we're going to move it + + align:start position:0% +final state and we're going to move it + + + align:start position:0% +final state and we're going to move it +directly in a straight line from the + + align:start position:0% +directly in a straight line from the + + + align:start position:0% +directly in a straight line from the +initial to the final state and this will + + align:start position:0% +initial to the final state and this will + + + align:start position:0% +initial to the final state and this will +be our path 1 and in our second case + + align:start position:0% +be our path 1 and in our second case + + + align:start position:0% +be our path 1 and in our second case +what we'd like to contrast with that is + + align:start position:0% +what we'd like to contrast with that is + + + align:start position:0% +what we'd like to contrast with that is +that we like to move the object out to a + + align:start position:0% +that we like to move the object out to a + + + align:start position:0% +that we like to move the object out to a +point X a and then back to the final + + align:start position:0% +point X a and then back to the final + + + align:start position:0% +point X a and then back to the final +point so this is our path 2 has two legs + + align:start position:0% +point so this is our path 2 has two legs + + + align:start position:0% +point so this is our path 2 has two legs +and we'd like to compare the work done + + align:start position:0% +and we'd like to compare the work done + + + align:start position:0% +and we'd like to compare the work done +on these two paths + + align:start position:0% +on these two paths + + + align:start position:0% +on these two paths +so for path 1 we'll begin by calculating + + align:start position:0% +so for path 1 we'll begin by calculating + + + align:start position:0% +so for path 1 we'll begin by calculating +our force here is the kinetic friction + + align:start position:0% +our force here is the kinetic friction + + + align:start position:0% +our force here is the kinetic friction +force and the kinetic friction force + + align:start position:0% +force and the kinetic friction force + + + align:start position:0% +force and the kinetic friction force +remember is in this case it's going to + + align:start position:0% +remember is in this case it's going to + + + align:start position:0% +remember is in this case it's going to +oppose the motion so we have force + + align:start position:0% +oppose the motion so we have force + + + align:start position:0% +oppose the motion so we have force +kinetic for path 1 and that is minus mu + + align:start position:0% +kinetic for path 1 and that is minus mu + + + align:start position:0% +kinetic for path 1 and that is minus mu +K mg in the I hat direction + + align:start position:0% +K mg in the I hat direction + + + align:start position:0% +K mg in the I hat direction +and so when we do the integral for the + + align:start position:0% +and so when we do the integral for the + + + align:start position:0% +and so when we do the integral for the +work from X initial 2x final this is + + align:start position:0% +work from X initial 2x final this is + + + align:start position:0% +work from X initial 2x final this is +path 1 then we have minus mu K mg I hat + + align:start position:0% +path 1 then we have minus mu K mg I hat + + + align:start position:0% +path 1 then we have minus mu K mg I hat +dotted into now what is the DS for this + + align:start position:0% +dotted into now what is the DS for this + + + align:start position:0% +dotted into now what is the DS for this +path it's simply DX i hat so DX I had + + align:start position:0% +path it's simply DX i hat so DX I had + + + align:start position:0% +path it's simply DX i hat so DX I had +notice we're not putting any sign into + + align:start position:0% +notice we're not putting any sign into + + + align:start position:0% +notice we're not putting any sign into +DX that's the sign will show up in terms + + align:start position:0% +DX that's the sign will show up in terms + + + align:start position:0% +DX that's the sign will show up in terms +of our endpoints of our integral so when + + align:start position:0% +of our endpoints of our integral so when + + + align:start position:0% +of our endpoints of our integral so when +we do the dot product here we have I had + + align:start position:0% +we do the dot product here we have I had + + + align:start position:0% +we do the dot product here we have I had +AI hat that's 1 and so this integral we + + align:start position:0% +AI hat that's 1 and so this integral we + + + align:start position:0% +AI hat that's 1 and so this integral we +can pull out all the constants Miu K mg + + align:start position:0% +can pull out all the constants Miu K mg + + + align:start position:0% +can pull out all the constants Miu K mg +we're just integrating DX from X initial + + align:start position:0% +we're just integrating DX from X initial + + + align:start position:0% +we're just integrating DX from X initial +to X final and so we get mu K + + align:start position:0% +to X final and so we get mu K + + + align:start position:0% +to X final and so we get mu K +mg times X final minus X initial now for + + align:start position:0% +mg times X final minus X initial now for + + + align:start position:0% +mg times X final minus X initial now for +path 2 we have two separate integrals so + + align:start position:0% +path 2 we have two separate integrals so + + + align:start position:0% +path 2 we have two separate integrals so +for path - we'll just show the first + + align:start position:0% +for path - we'll just show the first + + + align:start position:0% +for path - we'll just show the first +part where we're going from X initial to + + align:start position:0% +part where we're going from X initial to + + + align:start position:0% +part where we're going from X initial to +XA then the friction force is opposing + + align:start position:0% +XA then the friction force is opposing + + + align:start position:0% +XA then the friction force is opposing +the motion and we always just write the + + align:start position:0% +the motion and we always just write the + + + align:start position:0% +the motion and we always just write the +X in terms of the coordinate system DX I + + align:start position:0% +X in terms of the coordinate system DX I + + + align:start position:0% +X in terms of the coordinate system DX I +have because you'll see that the signs + + align:start position:0% +have because you'll see that the signs + + + align:start position:0% +have because you'll see that the signs +show up in the endpoints of the integral + + align:start position:0% +show up in the endpoints of the integral + + + align:start position:0% +show up in the endpoints of the integral +and then when we're coming back I'll put + + align:start position:0% +and then when we're coming back I'll put + + + align:start position:0% +and then when we're coming back I'll put +that in a different color and I'll put + + align:start position:0% +that in a different color and I'll put + + + align:start position:0% +that in a different color and I'll put +it below it so when we come back + + align:start position:0% +it below it so when we come back + + + align:start position:0% +it below it so when we come back +notice the friction force is going to + + align:start position:0% +notice the friction force is going to + + + align:start position:0% +notice the friction force is going to +change direction D s will still be + + align:start position:0% +change direction D s will still be + + + align:start position:0% +change direction D s will still be +written that way but pay close attention + + align:start position:0% +written that way but pay close attention + + + align:start position:0% +written that way but pay close attention +to the endpoints of the interval so now + + align:start position:0% +to the endpoints of the interval so now + + + align:start position:0% +to the endpoints of the interval so now +what we have is two intervals so W is + + align:start position:0% +what we have is two intervals so W is + + + align:start position:0% +what we have is two intervals so W is +the integral from X initial to XA and + + align:start position:0% +the integral from X initial to XA and + + + align:start position:0% +the integral from X initial to XA and +now I'm going to take the dot products + + align:start position:0% +now I'm going to take the dot products + + + align:start position:0% +now I'm going to take the dot products +here directly it's the same friction + + align:start position:0% +here directly it's the same friction + + + align:start position:0% +here directly it's the same friction +force we still have this same integral + + align:start position:0% +force we still have this same integral + + + align:start position:0% +force we still have this same integral +which is minus mu K mg DX now here's + + align:start position:0% +which is minus mu K mg DX now here's + + + align:start position:0% +which is minus mu K mg DX now here's +where it's a little bit tricky notice on + + align:start position:0% +where it's a little bit tricky notice on + + + align:start position:0% +where it's a little bit tricky notice on +this path FK is plus mu K mg I hat and + + align:start position:0% +this path FK is plus mu K mg I hat and + + + align:start position:0% +this path FK is plus mu K mg I hat and +so when we dotted into D X we have a + + align:start position:0% +so when we dotted into D X we have a + + + align:start position:0% +so when we dotted into D X we have a +plus sign we'll just continue that + + align:start position:0% +plus sign we'll just continue that + + + align:start position:0% +plus sign we'll just continue that +integration here of mu K mg DX from X a + + align:start position:0% +integration here of mu K mg DX from X a + + + align:start position:0% +integration here of mu K mg DX from X a +2x final both of these integrals are + + align:start position:0% +2x final both of these integrals are + + + align:start position:0% +2x final both of these integrals are +straightforward integrals to do this is + + align:start position:0% +straightforward integrals to do this is + + + align:start position:0% +straightforward integrals to do this is +minus mu K mg X a minus X initial and + + align:start position:0% +minus mu K mg X a minus X initial and + + + align:start position:0% +minus mu K mg X a minus X initial and +over here we have a plus mu K mg X final + + align:start position:0% +over here we have a plus mu K mg X final + + + align:start position:0% +over here we have a plus mu K mg X final +minus X initial notice X final minus X X + + align:start position:0% +minus X initial notice X final minus X X + + + align:start position:0% +minus X initial notice X final minus X X +a rather is negative and so both of + + align:start position:0% +a rather is negative and so both of + + + align:start position:0% +a rather is negative and so both of +these integrals are negative as we + + align:start position:0% +these integrals are negative as we + + + align:start position:0% +these integrals are negative as we +expect and so what we see here is that + + align:start position:0% +expect and so what we see here is that + + + align:start position:0% +expect and so what we see here is that +we have two pieces so minus 2 mu K and + + align:start position:0% +we have two pieces so minus 2 mu K and + + + align:start position:0% +we have two pieces so minus 2 mu K and +G XA and then we have that other piece + + align:start position:0% +G XA and then we have that other piece + + + align:start position:0% +G XA and then we have that other piece +mu K mg X final minus X initial hang on + + align:start position:0% +mu K mg X final minus X initial hang on + + + align:start position:0% +mu K mg X final minus X initial hang on +there's a this is actually a plus sign + + align:start position:0% +there's a this is actually a plus sign + + + align:start position:0% +there's a this is actually a plus sign +so our answer is very different because + + align:start position:0% +so our answer is very different because + + + align:start position:0% +so our answer is very different because +the displace the amount that we've + + align:start position:0% +the displace the amount that we've + + + align:start position:0% +the displace the amount that we've +traveled is different so what we see + + align:start position:0% +traveled is different so what we see + + + align:start position:0% +traveled is different so what we see +here is an example of a force which is + + align:start position:0% +here is an example of a force which is + + + align:start position:0% +here is an example of a force which is +the work done is not path independent + + align:start position:0% +the work done is not path independent + + + align:start position:0% +the work done is not path independent +but depends on the path taken from the + + align:start position:0% +but depends on the path taken from the + + + align:start position:0% +but depends on the path taken from the +initial to the final States \ No newline at end of file diff --git a/0tI1CRv-DPs.txt b/0tI1CRv-DPs.txt new file mode 100644 index 0000000000000000000000000000000000000000..f8f7012bef27cdfc0dc8c415b909d052a3768134 --- /dev/null +++ b/0tI1CRv-DPs.txt @@ -0,0 +1,18394 @@ +align:start position:0% + +so what we're talking about today is a + + align:start position:0% +so what we're talking about today is a + + + align:start position:0% +so what we're talking about today is a +very practical + + align:start position:0% +very practical + + + align:start position:0% +very practical +genomic medicine by which i mean + + align:start position:0% +genomic medicine by which i mean + + + align:start position:0% +genomic medicine by which i mean +not any stuff that we think is going to + + align:start position:0% +not any stuff that we think is going to + + + align:start position:0% +not any stuff that we think is going to +be imminent + + align:start position:0% +be imminent + + + align:start position:0% +be imminent +in two years + + align:start position:0% +in two years + + + align:start position:0% +in two years +but what it means today to do genetic + + align:start position:0% +but what it means today to do genetic + + + align:start position:0% +but what it means today to do genetic +medicine nothing a future just today and + + align:start position:0% +medicine nothing a future just today and + + + align:start position:0% +medicine nothing a future just today and +if you think that i have stepped across + + align:start position:0% +if you think that i have stepped across + + + align:start position:0% +if you think that i have stepped across +the line into the future call me on it + + align:start position:0% +the line into the future call me on it + + + align:start position:0% +the line into the future call me on it +so let's talk about the few different + + align:start position:0% +so let's talk about the few different + + + align:start position:0% +so let's talk about the few different +diffusions of knowledge + + align:start position:0% +diffusions of knowledge + + + align:start position:0% +diffusions of knowledge +the + + align:start position:0% +the + + + align:start position:0% +the +genome draft as you know was uh much + + align:start position:0% +genome draft as you know was uh much + + + align:start position:0% +genome draft as you know was uh much +harold did with uh + + align:start position:0% +harold did with uh + + + align:start position:0% +harold did with uh +clinton was clinton still present in + + align:start position:0% +clinton was clinton still present in + + + align:start position:0% +clinton was clinton still present in +2001 no + + align:start position:0% +2001 no + + + align:start position:0% +2001 no +so before when was the draft the first + + align:start position:0% +so before when was the draft the first + + + align:start position:0% +so before when was the draft the first +time + + align:start position:0% + + + + align:start position:0% + +when was benter venter and um + + align:start position:0% +when was benter venter and um + + + align:start position:0% +when was benter venter and um +and collins and clint wasn't clinton + + align:start position:0% +and collins and clint wasn't clinton + + + align:start position:0% +and collins and clint wasn't clinton +yeah it was clinton + + align:start position:0% +yeah it was clinton + + + align:start position:0% +yeah it was clinton +it was 2000. so that's an error uh so + + align:start position:0% +it was 2000. so that's an error uh so + + + align:start position:0% +it was 2000. so that's an error uh so +much heralded and there was a lot of + + align:start position:0% +much heralded and there was a lot of + + + align:start position:0% +much heralded and there was a lot of +promise about this would solve + + align:start position:0% +promise about this would solve + + + align:start position:0% +promise about this would solve +problems in human disease and in + + align:start position:0% +problems in human disease and in + + + align:start position:0% +problems in human disease and in +medicine and it made it sound the way it + + align:start position:0% +medicine and it made it sound the way it + + + align:start position:0% +medicine and it made it sound the way it +was described it was fairly imminent + + align:start position:0% +was described it was fairly imminent + + + align:start position:0% +was described it was fairly imminent +and it was going to transform medicine + + align:start position:0% +and it was going to transform medicine + + + align:start position:0% +and it was going to transform medicine +and just as a measure of calibration + + align:start position:0% +and just as a measure of calibration + + + align:start position:0% +and just as a measure of calibration +the development of peninsula by jane and + + align:start position:0% +the development of peninsula by jane and + + + align:start position:0% +the development of peninsula by jane and +flory in 41 was saving thousands of + + align:start position:0% +flory in 41 was saving thousands of + + + align:start position:0% +flory in 41 was saving thousands of +lives within months + + align:start position:0% +lives within months + + + align:start position:0% +lives within months +and + + align:start position:0% +and + + + align:start position:0% +and +so has genomic medicine been successful + + align:start position:0% +so has genomic medicine been successful + + + align:start position:0% +so has genomic medicine been successful +by that measure + + align:start position:0% +by that measure + + + align:start position:0% +by that measure +no + + align:start position:0% + + + + align:start position:0% + +do we think it's going to impact um + + align:start position:0% +do we think it's going to impact um + + + align:start position:0% +do we think it's going to impact um +medicine in the future well sure i think + + align:start position:0% +medicine in the future well sure i think + + + align:start position:0% +medicine in the future well sure i think +i i hope i've convinced you that in the + + align:start position:0% +i i hope i've convinced you that in the + + + align:start position:0% +i i hope i've convinced you that in the +course of the class that it's going to + + align:start position:0% +course of the class that it's going to + + + align:start position:0% +course of the class that it's going to +be important in a way we diagnose our + + align:start position:0% +be important in a way we diagnose our + + + align:start position:0% +be important in a way we diagnose our +patients and the way we imagine patients + + align:start position:0% +patients and the way we imagine patients + + + align:start position:0% +patients and the way we imagine patients +even the way we treat our patients but + + align:start position:0% +even the way we treat our patients but + + + align:start position:0% +even the way we treat our patients but +clearly not by this measure and i think + + align:start position:0% +clearly not by this measure and i think + + + align:start position:0% +clearly not by this measure and i think +we have to all appreciate that probably + + align:start position:0% +we have to all appreciate that probably + + + align:start position:0% +we have to all appreciate that probably +the time scales on the order of uh + + align:start position:0% +the time scales on the order of uh + + + align:start position:0% +the time scales on the order of uh +10 to 20 years and in fact one of my + + align:start position:0% +10 to 20 years and in fact one of my + + + align:start position:0% +10 to 20 years and in fact one of my +colleagues uh one of my friends is uh + + align:start position:0% +colleagues uh one of my friends is uh + + + align:start position:0% +colleagues uh one of my friends is uh +used to be a reporter for the new york + + align:start position:0% +used to be a reporter for the new york + + + align:start position:0% +used to be a reporter for the new york +times when this was announced in 2000 + + align:start position:0% +times when this was announced in 2000 + + + align:start position:0% +times when this was announced in 2000 +asked me so what's going to be the main + + align:start position:0% +asked me so what's going to be the main + + + align:start position:0% +asked me so what's going to be the main +impact of the of the + + align:start position:0% +impact of the of the + + + align:start position:0% +impact of the of the +human genome draft for the next 10 years + + align:start position:0% +human genome draft for the next 10 years + + + align:start position:0% +human genome draft for the next 10 years +i said a lot of bad news and what by + + align:start position:0% +i said a lot of bad news and what by + + + align:start position:0% +i said a lot of bad news and what by +which i meant that we're probably going + + align:start position:0% +which i meant that we're probably going + + + align:start position:0% +which i meant that we're probably going +to be able to diagnose a lot of things + + align:start position:0% +to be able to diagnose a lot of things + + + align:start position:0% +to be able to diagnose a lot of things +that we have not been diagnosed and do + + align:start position:0% +that we have not been diagnosed and do + + + align:start position:0% +that we have not been diagnosed and do +nothing about it + + align:start position:0% + + + + align:start position:0% + +and that's probably why not but there's + + align:start position:0% +and that's probably why not but there's + + + align:start position:0% +and that's probably why not but there's +another reason why not which is um well + + align:start position:0% +another reason why not which is um well + + + align:start position:0% +another reason why not which is um well +why do you think there's what other + + align:start position:0% +why do you think there's what other + + + align:start position:0% +why do you think there's what other +problems have there been + + align:start position:0% +problems have there been + + + align:start position:0% +problems have there been +in preventing the diffusion of + + align:start position:0% +in preventing the diffusion of + + + align:start position:0% +in preventing the diffusion of +genomic medicine any ideas + + align:start position:0% + + + + align:start position:0% + +what massive amounts massive amounts of + + align:start position:0% +what massive amounts massive amounts of + + + align:start position:0% +what massive amounts massive amounts of +data and + + align:start position:0% +data and + + + align:start position:0% +data and +lack of trained personnel + + align:start position:0% +lack of trained personnel + + + align:start position:0% +lack of trained personnel +basically the medical system does not + + align:start position:0% +basically the medical system does not + + + align:start position:0% +basically the medical system does not +have any idea how to deal with this and + + align:start position:0% +have any idea how to deal with this and + + + align:start position:0% +have any idea how to deal with this and +just to give you some uh calibration + + align:start position:0% +just to give you some uh calibration + + + align:start position:0% +just to give you some uh calibration +around that i gave a lecture + + align:start position:0% + + + + align:start position:0% + +here ago to the american professors of + + align:start position:0% +here ago to the american professors of + + + align:start position:0% +here ago to the american professors of +medical genetics genomics medical + + align:start position:0% +medical genetics genomics medical + + + align:start position:0% +medical genetics genomics medical +genetics and i was telling them about + + align:start position:0% +genetics and i was telling them about + + + align:start position:0% +genetics and i was telling them about +the whole genomic revolution + + align:start position:0% +the whole genomic revolution + + + align:start position:0% +the whole genomic revolution +and + + align:start position:0% +and + + + align:start position:0% +and +you might think it's an odd thing for me + + align:start position:0% +you might think it's an odd thing for me + + + align:start position:0% +you might think it's an odd thing for me +to talk to professors of medical + + align:start position:0% +to talk to professors of medical + + + align:start position:0% +to talk to professors of medical +genetics in the national association + + align:start position:0% +genetics in the national association + + + align:start position:0% +genetics in the national association +but they were + + align:start position:0% +but they were + + + align:start position:0% +but they were +they were polite and interested in my + + align:start position:0% +they were polite and interested in my + + + align:start position:0% +they were polite and interested in my +lecture but i asked them is this what + + align:start position:0% +lecture but i asked them is this what + + + align:start position:0% +lecture but i asked them is this what +you see yourself doing for the next uh + + align:start position:0% +you see yourself doing for the next uh + + + align:start position:0% +you see yourself doing for the next uh +20 years absolutely not they wanted to + + align:start position:0% +20 years absolutely not they wanted to + + + align:start position:0% +20 years absolutely not they wanted to +restrict themselves to monogenic + + align:start position:0% +restrict themselves to monogenic + + + align:start position:0% +restrict themselves to monogenic +strongly highly penetrant diseases uh + + align:start position:0% +strongly highly penetrant diseases uh + + + align:start position:0% +strongly highly penetrant diseases uh +that were extremely rare that's what + + align:start position:0% +that were extremely rare that's what + + + align:start position:0% +that were extremely rare that's what +they want to do and you know i said well + + align:start position:0% +they want to do and you know i said well + + + align:start position:0% +they want to do and you know i said well +you know + + align:start position:0% +you know + + + align:start position:0% +you know +you share at least a substring with the + + align:start position:0% +you share at least a substring with the + + + align:start position:0% +you share at least a substring with the +genomics uh don't you see this part of + + align:start position:0% +genomics uh don't you see this part of + + + align:start position:0% +genomics uh don't you see this part of +your field no + + align:start position:0% +your field no + + + align:start position:0% +your field no +and + + align:start position:0% +and + + + align:start position:0% +and +so the genesis are not + + align:start position:0% +so the genesis are not + + + align:start position:0% +so the genesis are not +holding the torch right now the medical + + align:start position:0% +holding the torch right now the medical + + + align:start position:0% +holding the torch right now the medical +students are not being + + align:start position:0% +students are not being + + + align:start position:0% +students are not being +uh taught this in any detail whatsoever + + align:start position:0% +uh taught this in any detail whatsoever + + + align:start position:0% +uh taught this in any detail whatsoever +and so + + align:start position:0% +and so + + + align:start position:0% +and so +there's a there's gonna be a problem so + + align:start position:0% +there's a there's gonna be a problem so + + + align:start position:0% +there's a there's gonna be a problem so +who is going to practice genomic + + align:start position:0% +who is going to practice genomic + + + align:start position:0% +who is going to practice genomic +medicine + + align:start position:0% +medicine + + + align:start position:0% +medicine +there's a variety of uh possibilities + + align:start position:0% +there's a variety of uh possibilities + + + align:start position:0% +there's a variety of uh possibilities +shown in um + + align:start position:0% +shown in um + + + align:start position:0% +shown in um +white blue for some reason is the + + align:start position:0% +white blue for some reason is the + + + align:start position:0% +white blue for some reason is the +medical geneticist the person who + + align:start position:0% +medical geneticist the person who + + + align:start position:0% +medical geneticist the person who +typically has been doing yeah sorry + + align:start position:0% +typically has been doing yeah sorry + + + align:start position:0% +typically has been doing yeah sorry +about that uh who is typically that'll + + align:start position:0% +about that uh who is typically that'll + + + align:start position:0% +about that uh who is typically that'll +be the last light blue um thing i hope + + align:start position:0% +be the last light blue um thing i hope + + + align:start position:0% +be the last light blue um thing i hope +um + + align:start position:0% +um + + + align:start position:0% +um +who's been doing medical diagnosis and + + align:start position:0% +who's been doing medical diagnosis and + + + align:start position:0% +who's been doing medical diagnosis and +counseling but what i'm telling you is + + align:start position:0% +counseling but what i'm telling you is + + + align:start position:0% +counseling but what i'm telling you is +they do not see themselves as + + align:start position:0% +they do not see themselves as + + + align:start position:0% +they do not see themselves as +bringing to four into the four + + align:start position:0% +bringing to four into the four + + + align:start position:0% +bringing to four into the four +the entirety of the impact of + + align:start position:0% +the entirety of the impact of + + + align:start position:0% +the entirety of the impact of +uh + + align:start position:0% +uh + + + align:start position:0% +uh +genetics + + align:start position:0% +genetics + + + align:start position:0% +genetics +into + + align:start position:0% +into + + + align:start position:0% +into +um the broad swath of diseases + + align:start position:0% +um the broad swath of diseases + + + align:start position:0% +um the broad swath of diseases +whether they're + + align:start position:0% +whether they're + + + align:start position:0% +whether they're +primarily inherited or primarily + + align:start position:0% +primarily inherited or primarily + + + align:start position:0% +primarily inherited or primarily +modifying um + + align:start position:0% +modifying um + + + align:start position:0% +modifying um +environmental influences a logical place + + align:start position:0% +environmental influences a logical place + + + align:start position:0% +environmental influences a logical place +would be primary care + + align:start position:0% +would be primary care + + + align:start position:0% +would be primary care +because after all + + align:start position:0% +because after all + + + align:start position:0% +because after all +as i hope i've convinced you if indeed + + align:start position:0% +as i hope i've convinced you if indeed + + + align:start position:0% +as i hope i've convinced you if indeed +part of what genomics gives you is the + + align:start position:0% +part of what genomics gives you is the + + + align:start position:0% +part of what genomics gives you is the +ability to prognosticate for the future + + align:start position:0% +ability to prognosticate for the future + + + align:start position:0% +ability to prognosticate for the future +part of preventive care + + align:start position:0% +part of preventive care + + + align:start position:0% +part of preventive care +should be + + align:start position:0% +should be + + + align:start position:0% +should be +genetic uh + + align:start position:0% +genetic uh + + + align:start position:0% +genetic uh +and genome-wide uh testing so + + align:start position:0% +and genome-wide uh testing so + + + align:start position:0% +and genome-wide uh testing so +pediatrician internist + + align:start position:0% +pediatrician internist + + + align:start position:0% +pediatrician internist +ob-gyn would be a natural place for this + + align:start position:0% +ob-gyn would be a natural place for this + + + align:start position:0% +ob-gyn would be a natural place for this +to to happen + + align:start position:0% +to to happen + + + align:start position:0% +to to happen +and also for specific diseases we've + + align:start position:0% +and also for specific diseases we've + + + align:start position:0% +and also for specific diseases we've +seen a lot of application of microarrays + + align:start position:0% +seen a lot of application of microarrays + + + align:start position:0% +seen a lot of application of microarrays +for to cancer for instance so oncologist + + align:start position:0% +for to cancer for instance so oncologist + + + align:start position:0% +for to cancer for instance so oncologist +would be a natural + + align:start position:0% + + + + align:start position:0% + +person to order these tests and the + + align:start position:0% +person to order these tests and the + + + align:start position:0% +person to order these tests and the +gastroenterologist we looked at crohn's + + align:start position:0% +gastroenterologist we looked at crohn's + + + align:start position:0% +gastroenterologist we looked at crohn's +disease and it would not be logical for + + align:start position:0% +disease and it would not be logical for + + + align:start position:0% +disease and it would not be logical for +a gastroenterologist to screen for risk + + align:start position:0% +a gastroenterologist to screen for risk + + + align:start position:0% +a gastroenterologist to screen for risk +factors + + align:start position:0% +factors + + + align:start position:0% +factors +so what's in fact the case + + align:start position:0% +so what's in fact the case + + + align:start position:0% +so what's in fact the case +so there was a study done just looking + + align:start position:0% +so there was a study done just looking + + + align:start position:0% +so there was a study done just looking +at cancer susceptibility tests + + align:start position:0% +at cancer susceptibility tests + + + align:start position:0% +at cancer susceptibility tests +so it's quite a substantial study + + align:start position:0% +so it's quite a substantial study + + + align:start position:0% +so it's quite a substantial study +looking at over + + align:start position:0% +looking at over + + + align:start position:0% +looking at over +1200 physicians 820 which were in + + align:start position:0% +1200 physicians 820 which were in + + + align:start position:0% +1200 physicians 820 which were in +primary care and in 12 months + + align:start position:0% +primary care and in 12 months + + + align:start position:0% +primary care and in 12 months +approximately 30 ordered + + align:start position:0% +approximately 30 ordered + + + align:start position:0% +approximately 30 ordered +or referred + + align:start position:0% +or referred + + + align:start position:0% +or referred +genetic + + align:start position:0% +genetic + + + align:start position:0% +genetic +uh testing + + align:start position:0% +uh testing + + + align:start position:0% +uh testing +looking for susceptibility + + align:start position:0% +looking for susceptibility + + + align:start position:0% +looking for susceptibility +not looking for + + align:start position:0% +not looking for + + + align:start position:0% +not looking for +diagnosing a patient but for looking + + align:start position:0% +diagnosing a patient but for looking + + + align:start position:0% +diagnosing a patient but for looking +were they at risk so that's kind of + + align:start position:0% +were they at risk so that's kind of + + + align:start position:0% +were they at risk so that's kind of +impressive + + align:start position:0% +impressive + + + align:start position:0% +impressive +it + + align:start position:0% +it + + + align:start position:0% +it +it's a bit less impressive that only + + align:start position:0% +it's a bit less impressive that only + + + align:start position:0% +it's a bit less impressive that only +seven percent of them directly + + align:start position:0% +seven percent of them directly + + + align:start position:0% +seven percent of them directly +did it whether + + align:start position:0% +did it whether + + + align:start position:0% +did it whether +because they were uncomfortable or not + + align:start position:0% +because they were uncomfortable or not + + + align:start position:0% +because they were uncomfortable or not +knowledgeable enough to actually + + align:start position:0% +knowledgeable enough to actually + + + align:start position:0% +knowledgeable enough to actually +directly order it but that's telling you + + align:start position:0% +directly order it but that's telling you + + + align:start position:0% +directly order it but that's telling you +that + + align:start position:0% +that + + + align:start position:0% +that +30 percent of this random sample + + align:start position:0% +30 percent of this random sample + + + align:start position:0% +30 percent of this random sample +of physicians were actually ordering + + align:start position:0% +of physicians were actually ordering + + + align:start position:0% +of physicians were actually ordering +these susceptibility tests + + align:start position:0% +these susceptibility tests + + + align:start position:0% +these susceptibility tests +what you imagine are the factors + + align:start position:0% +what you imagine are the factors + + + align:start position:0% +what you imagine are the factors +affecting + + align:start position:0% +affecting + + + align:start position:0% +affecting +ordering + + align:start position:0% +ordering + + + align:start position:0% +ordering +let me give you some + + align:start position:0% +let me give you some + + + align:start position:0% +let me give you some +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +some potential what were you saying + + align:start position:0% +some potential what were you saying + + + align:start position:0% +some potential what were you saying +cost + + align:start position:0% +cost + + + align:start position:0% +cost +any other suggestions + + align:start position:0% + + + + align:start position:0% + +whether you can interpret the test any + + align:start position:0% +whether you can interpret the test any + + + align:start position:0% +whether you can interpret the test any +other suggestions + + align:start position:0% +other suggestions + + + align:start position:0% +other suggestions +it's not what what + + align:start position:0% +it's not what what + + + align:start position:0% +it's not what what +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +which one which physicians were more + + align:start position:0% +which one which physicians were more + + + align:start position:0% +which one which physicians were more +likely no no what i meant was which + + align:start position:0% +likely no no what i meant was which + + + align:start position:0% +likely no no what i meant was which +physicians were more likely to order + + align:start position:0% +physicians were more likely to order + + + align:start position:0% +physicians were more likely to order +tests i apologize for it let me rephrase + + align:start position:0% +tests i apologize for it let me rephrase + + + align:start position:0% +tests i apologize for it let me rephrase +the question + + align:start position:0% +the question + + + align:start position:0% +the question +what was it about them + + align:start position:0% +what was it about them + + + align:start position:0% +what was it about them +what property of the physicians made + + align:start position:0% +what property of the physicians made + + + align:start position:0% +what property of the physicians made +them much more likely to + + align:start position:0% +them much more likely to + + + align:start position:0% +them much more likely to +research hospitals + + align:start position:0% + + + + align:start position:0% + +disease areas where there's a lot of + + align:start position:0% +disease areas where there's a lot of + + + align:start position:0% +disease areas where there's a lot of +places where they have the high burden + + align:start position:0% +places where they have the high burden + + + align:start position:0% +places where they have the high burden +of uh genetically um disease + + align:start position:0% +of uh genetically um disease + + + align:start position:0% +of uh genetically um disease +well here's the answer the first and + + align:start position:0% +well here's the answer the first and + + + align:start position:0% +well here's the answer the first and +foremost was it being in the northeast + + align:start position:0% + + + + align:start position:0% + +i don't know what it means but that's in + + align:start position:0% +i don't know what it means but that's in + + + align:start position:0% +i don't know what it means but that's in +fact + + align:start position:0% +fact + + + align:start position:0% +fact +was a by far so there's plenty of uh + + align:start position:0% +was a by far so there's plenty of uh + + + align:start position:0% +was a by far so there's plenty of uh +wonderful tertiary care centers on the + + align:start position:0% +wonderful tertiary care centers on the + + + align:start position:0% +wonderful tertiary care centers on the +west coast i hear um but that was not a + + align:start position:0% +west coast i hear um but that was not a + + + align:start position:0% +west coast i hear um but that was not a +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a telling thing feeling confident as you + + align:start position:0% +a telling thing feeling confident as you + + + align:start position:0% +a telling thing feeling confident as you +mentioned + + align:start position:0% +mentioned + + + align:start position:0% +mentioned +um + + align:start position:0% +um + + + align:start position:0% +um +presence of advertising materials + + align:start position:0% +presence of advertising materials + + + align:start position:0% +presence of advertising materials +and most importantly + + align:start position:0% +and most importantly + + + align:start position:0% +and most importantly +having the patient ask for it the point + + align:start position:0% +having the patient ask for it the point + + + align:start position:0% +having the patient ask for it the point +here is that the reason that was such a + + align:start position:0% +here is that the reason that was such a + + + align:start position:0% +here is that the reason that was such a +high + + align:start position:0% +high + + + align:start position:0% +high +percentage 30 percent is not because + + align:start position:0% +percentage 30 percent is not because + + + align:start position:0% +percentage 30 percent is not because +doctors have been trained + + align:start position:0% +doctors have been trained + + + align:start position:0% +doctors have been trained +to order this test it's because patients + + align:start position:0% +to order this test it's because patients + + + align:start position:0% +to order this test it's because patients +are reading um the lay literature and if + + align:start position:0% +are reading um the lay literature and if + + + align:start position:0% +are reading um the lay literature and if +they have breast cancer in in the family + + align:start position:0% +they have breast cancer in in the family + + + align:start position:0% +they have breast cancer in in the family +or they have ovarian cancer or they have + + align:start position:0% +or they have ovarian cancer or they have + + + align:start position:0% +or they have ovarian cancer or they have +um + + align:start position:0% +um + + + align:start position:0% +um +colon cancer they're asking the doctors + + align:start position:0% +colon cancer they're asking the doctors + + + align:start position:0% +colon cancer they're asking the doctors +to test them that's + + align:start position:0% +to test them that's + + + align:start position:0% +to test them that's +that's that's the uh the real insight + + align:start position:0% +that's that's the uh the real insight + + + align:start position:0% +that's that's the uh the real insight +let me just answer this + + align:start position:0% + + + + align:start position:0% + +hi + + align:start position:0% +hi + + + align:start position:0% +hi +hi i'm teaching a class can i call you + + align:start position:0% +hi i'm teaching a class can i call you + + + align:start position:0% +hi i'm teaching a class can i call you +back + + align:start position:0% + + + + align:start position:0% + +go ahead um when you say testosterone + + align:start position:0% +go ahead um when you say testosterone + + + align:start position:0% +go ahead um when you say testosterone +susceptibility this is presumably some + + align:start position:0% +susceptibility this is presumably some + + + align:start position:0% +susceptibility this is presumably some +kind of multiplex pcr looking at + + align:start position:0% +kind of multiplex pcr looking at + + + align:start position:0% +kind of multiplex pcr looking at +different alleles + + align:start position:0% +different alleles + + + align:start position:0% +different alleles +there are associated or is it actually a + + align:start position:0% +there are associated or is it actually a + + + align:start position:0% +there are associated or is it actually a +genomic plastic + + align:start position:0% + + + + align:start position:0% + +no this is corrected for it + + align:start position:0% +no this is corrected for it + + + align:start position:0% +no this is corrected for it +for yeah + + align:start position:0% +for yeah + + + align:start position:0% +for yeah +it's something else it's it's corrected + + align:start position:0% +it's something else it's it's corrected + + + align:start position:0% +it's something else it's it's corrected +for it something about + + align:start position:0% +for it something about + + + align:start position:0% +for it something about +the um nature of the training or maybe + + align:start position:0% +the um nature of the training or maybe + + + align:start position:0% +the um nature of the training or maybe +patience in the + + align:start position:0% + + + + align:start position:0% + +northeast maybe + + align:start position:0% +northeast maybe + + + align:start position:0% +northeast maybe +let's put it this way maybe there's a + + align:start position:0% +let's put it this way maybe there's a + + + align:start position:0% +let's put it this way maybe there's a +lot of astronomy jewish women + + align:start position:0% +lot of astronomy jewish women + + + align:start position:0% +lot of astronomy jewish women +worried about breast cancer knowing that + + align:start position:0% +worried about breast cancer knowing that + + + align:start position:0% +worried about breast cancer knowing that +they have this braca one bracket two + + align:start position:0% +they have this braca one bracket two + + + align:start position:0% +they have this braca one bracket two +risk factor + + align:start position:0% +risk factor + + + align:start position:0% +risk factor +that the article did not um actually + + align:start position:0% +that the article did not um actually + + + align:start position:0% +that the article did not um actually +elaborate on that but that's my guess i + + align:start position:0% +elaborate on that but that's my guess i + + + align:start position:0% +elaborate on that but that's my guess i +think the patients are the driving + + align:start position:0% +think the patients are the driving + + + align:start position:0% +think the patients are the driving +factor and for those of us who are in + + align:start position:0% +factor and for those of us who are in + + + align:start position:0% +factor and for those of us who are in +medicine + + align:start position:0% +medicine + + + align:start position:0% +medicine +i think we have to recognize this and + + align:start position:0% +i think we have to recognize this and + + + align:start position:0% +i think we have to recognize this and +it's actually a sad fact that it's the + + align:start position:0% +it's actually a sad fact that it's the + + + align:start position:0% +it's actually a sad fact that it's the +patients are driving it but it's a + + align:start position:0% +patients are driving it but it's a + + + align:start position:0% +patients are driving it but it's a +problem because + + align:start position:0% +problem because + + + align:start position:0% +problem because +um if + + align:start position:0% +um if + + + align:start position:0% +um if +one of the things that you bring to to + + align:start position:0% +one of the things that you bring to to + + + align:start position:0% +one of the things that you bring to to +bear as a doctor is an appreciation of + + align:start position:0% +bear as a doctor is an appreciation of + + + align:start position:0% +bear as a doctor is an appreciation of +prior probability and + + align:start position:0% +prior probability and + + + align:start position:0% +prior probability and +what is + + align:start position:0% +what is + + + align:start position:0% +what is +what tests you want to do + + align:start position:0% +what tests you want to do + + + align:start position:0% +what tests you want to do +in order to avoid false positives + + align:start position:0% +in order to avoid false positives + + + align:start position:0% +in order to avoid false positives +because remember a lot of these + + align:start position:0% +because remember a lot of these + + + align:start position:0% +because remember a lot of these +polymorphisms or mutations may not + + align:start position:0% +polymorphisms or mutations may not + + + align:start position:0% +polymorphisms or mutations may not +actually be the causative + + align:start position:0% +actually be the causative + + + align:start position:0% +actually be the causative +um element they may be in linkage + + align:start position:0% +um element they may be in linkage + + + align:start position:0% +um element they may be in linkage +describing for instance + + align:start position:0% +describing for instance + + + align:start position:0% +describing for instance +and so + + align:start position:0% +and so + + + align:start position:0% +and so +it's not a one-to-one it's not if you + + align:start position:0% +it's not a one-to-one it's not if you + + + align:start position:0% +it's not a one-to-one it's not if you +have this + + align:start position:0% +have this + + + align:start position:0% +have this +you're going to have cancer it's a it's + + align:start position:0% +you're going to have cancer it's a it's + + + align:start position:0% +you're going to have cancer it's a it's +a problem measure and so there's going + + align:start position:0% +a problem measure and so there's going + + + align:start position:0% +a problem measure and so there's going +to be a false positive rate with any of + + align:start position:0% +to be a false positive rate with any of + + + align:start position:0% +to be a false positive rate with any of +these uh + + align:start position:0% +these uh + + + align:start position:0% +these uh +measures and if the doctor is really not + + align:start position:0% +measures and if the doctor is really not + + + align:start position:0% +measures and if the doctor is really not +knowledgeable about that interpretation + + align:start position:0% +knowledgeable about that interpretation + + + align:start position:0% +knowledgeable about that interpretation +uh then + + align:start position:0% +uh then + + + align:start position:0% +uh then +they're going to find problems just as + + align:start position:0% +they're going to find problems just as + + + align:start position:0% +they're going to find problems just as +if doctors did routine + + align:start position:0% +if doctors did routine + + + align:start position:0% +if doctors did routine +ct scans on everybody you'd find on the + + align:start position:0% +ct scans on everybody you'd find on the + + + align:start position:0% +ct scans on everybody you'd find on the +order of + + align:start position:0% +order of + + + align:start position:0% +order of +people my age maybe 10 to 20 pituitary + + align:start position:0% +people my age maybe 10 to 20 pituitary + + + align:start position:0% +people my age maybe 10 to 20 pituitary +microadenomas + + align:start position:0% +microadenomas + + + align:start position:0% +microadenomas +as we as we find when we do + + align:start position:0% +as we as we find when we do + + + align:start position:0% +as we as we find when we do +autopsies of car accidents and people my + + align:start position:0% +autopsies of car accidents and people my + + + align:start position:0% +autopsies of car accidents and people my +age but they have no clinical meaning + + align:start position:0% +age but they have no clinical meaning + + + align:start position:0% +age but they have no clinical meaning +that we can tell + + align:start position:0% +that we can tell + + + align:start position:0% +that we can tell +but if you do routine testing you'll + + align:start position:0% +but if you do routine testing you'll + + + align:start position:0% +but if you do routine testing you'll +find that and this is going to create a + + align:start position:0% +find that and this is going to create a + + + align:start position:0% +find that and this is going to create a +huge problem of false positives if we + + align:start position:0% +huge problem of false positives if we + + + align:start position:0% +huge problem of false positives if we +continue to have patient-driven demand + + align:start position:0% +continue to have patient-driven demand + + + align:start position:0% +continue to have patient-driven demand +for testing because + + align:start position:0% +for testing because + + + align:start position:0% +for testing because +it should be done knowledgeably or would + + align:start position:0% +it should be done knowledgeably or would + + + align:start position:0% +it should be done knowledgeably or would +that cannot be um met with like so if + + align:start position:0% +that cannot be um met with like so if + + + align:start position:0% +that cannot be um met with like so if +the doctor orders this or has refers + + align:start position:0% +the doctor orders this or has refers + + + align:start position:0% +the doctor orders this or has refers +them to a specialist + + align:start position:0% +them to a specialist + + + align:start position:0% +them to a specialist +um when these tests come back + + align:start position:0% +um when these tests come back + + + align:start position:0% +um when these tests come back +uh i'm assuming they don't + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +the short answer is + + align:start position:0% +the short answer is + + + align:start position:0% +the short answer is +theoretically not + + align:start position:0% + + + + align:start position:0% + +no this actually has to be personal + + align:start position:0% +no this actually has to be personal + + + align:start position:0% +no this actually has to be personal +we'll get we'll get to that but even so + + align:start position:0% +we'll get we'll get to that but even so + + + align:start position:0% +we'll get we'll get to that but even so +if you have uh an ascertainment bias + + align:start position:0% +if you have uh an ascertainment bias + + + align:start position:0% +if you have uh an ascertainment bias +because of who's doing it without + + align:start position:0% +because of who's doing it without + + + align:start position:0% +because of who's doing it without +actually um letting the medical system + + align:start position:0% +actually um letting the medical system + + + align:start position:0% +actually um letting the medical system +try to define + + align:start position:0% +try to define + + + align:start position:0% +try to define +a uh appropriate uh measure when you do + + align:start position:0% +a uh appropriate uh measure when you do + + + align:start position:0% +a uh appropriate uh measure when you do +a test + + align:start position:0% +a test + + + align:start position:0% +a test +then you you can run into those problems + + align:start position:0% +then you you can run into those problems + + + align:start position:0% +then you you can run into those problems +more than less + + align:start position:0% +more than less + + + align:start position:0% +more than less +oh so you're suggesting that maybe + + align:start position:0% +oh so you're suggesting that maybe + + + align:start position:0% +oh so you're suggesting that maybe +so patients are asking for particular + + align:start position:0% +so patients are asking for particular + + + align:start position:0% +so patients are asking for particular +tests because they were they're worried + + align:start position:0% +tests because they were they're worried + + + align:start position:0% +tests because they were they're worried +and you're suggesting that maybe that's + + align:start position:0% +and you're suggesting that maybe that's + + + align:start position:0% +and you're suggesting that maybe that's +a bad + + align:start position:0% +a bad + + + align:start position:0% +a bad +thing not because + + align:start position:0% +thing not because + + + align:start position:0% +thing not because +the doctor should be the ones to just + + align:start position:0% +the doctor should be the ones to just + + + align:start position:0% +the doctor should be the ones to just +to say hey you might want to think of + + align:start position:0% +to say hey you might want to think of + + + align:start position:0% +to say hey you might want to think of +this but you're saying that it's uh + + align:start position:0% +this but you're saying that it's uh + + + align:start position:0% +this but you're saying that it's uh +maybe they it's it's a self-selected + + align:start position:0% +maybe they it's it's a self-selected + + + align:start position:0% +maybe they it's it's a self-selected +group + + align:start position:0% +group + + + align:start position:0% +group +and it may be that the people who are + + align:start position:0% +and it may be that the people who are + + + align:start position:0% +and it may be that the people who are +truly at risk are are not + + align:start position:0% +truly at risk are are not + + + align:start position:0% +truly at risk are are not +getting tested basically the doctor is + + align:start position:0% +getting tested basically the doctor is + + + align:start position:0% +getting tested basically the doctor is +not it's not a decision maker here and + + align:start position:0% +not it's not a decision maker here and + + + align:start position:0% +not it's not a decision maker here and +the whole role of a doctor is to decide + + align:start position:0% +the whole role of a doctor is to decide + + + align:start position:0% +the whole role of a doctor is to decide +if anything when is a test + + align:start position:0% +if anything when is a test + + + align:start position:0% +if anything when is a test +going to be cost effective and + + align:start position:0% +going to be cost effective and + + + align:start position:0% +going to be cost effective and +sufficiently uh useful for the patient + + align:start position:0% +sufficiently uh useful for the patient + + + align:start position:0% +sufficiently uh useful for the patient +and if they disintermediate themselves + + align:start position:0% +and if they disintermediate themselves + + + align:start position:0% +and if they disintermediate themselves +allow the patient to do that + + align:start position:0% +allow the patient to do that + + + align:start position:0% +allow the patient to do that +then there's a risk that there's a group + + align:start position:0% +then there's a risk that there's a group + + + align:start position:0% +then there's a risk that there's a group +of people who won't be screened and a + + align:start position:0% +of people who won't be screened and a + + + align:start position:0% +of people who won't be screened and a +group of people who are being over + + align:start position:0% +group of people who are being over + + + align:start position:0% +group of people who are being over +screened and therefore have a like + + align:start position:0% +screened and therefore have a like + + + align:start position:0% +screened and therefore have a like +unacceptably high false positive rate + + align:start position:0% +unacceptably high false positive rate + + + align:start position:0% +unacceptably high false positive rate +because basically when people come up + + align:start position:0% +because basically when people come up + + + align:start position:0% +because basically when people come up +with calculations of um + + align:start position:0% +with calculations of um + + + align:start position:0% +with calculations of um +sensitivity specificity they do it based + + align:start position:0% +sensitivity specificity they do it based + + + align:start position:0% +sensitivity specificity they do it based +on a certain population of patients when + + align:start position:0% +on a certain population of patients when + + + align:start position:0% +on a certain population of patients when +the genetic counselor says you have x y + + align:start position:0% +the genetic counselor says you have x y + + + align:start position:0% +the genetic counselor says you have x y +percent risk + + align:start position:0% +percent risk + + + align:start position:0% +percent risk +based on a general population + + align:start position:0% +based on a general population + + + align:start position:0% +based on a general population +they don't base it on the the group of + + align:start position:0% +they don't base it on the the group of + + + align:start position:0% +they don't base it on the the group of +patients who are neurotic and worried + + align:start position:0% +patients who are neurotic and worried + + + align:start position:0% +patients who are neurotic and worried +maybe appropriately about their family + + align:start position:0% +maybe appropriately about their family + + + align:start position:0% +maybe appropriately about their family +history maybe that might be a different + + align:start position:0% +history maybe that might be a different + + + align:start position:0% +history maybe that might be a different +set of specificity and sensitivities i'm + + align:start position:0% +set of specificity and sensitivities i'm + + + align:start position:0% +set of specificity and sensitivities i'm +not saying that patients are wrong to be + + align:start position:0% +not saying that patients are wrong to be + + + align:start position:0% +not saying that patients are wrong to be +worried what i'm saying is + + align:start position:0% +worried what i'm saying is + + + align:start position:0% +worried what i'm saying is +the medical system is failing they don't + + align:start position:0% +the medical system is failing they don't + + + align:start position:0% +the medical system is failing they don't +have educated doctors who can + + align:start position:0% +have educated doctors who can + + + align:start position:0% +have educated doctors who can +intermediate intermediate about what is + + align:start position:0% +intermediate intermediate about what is + + + align:start position:0% +intermediate intermediate about what is +appropriate testing to be done i mean if + + align:start position:0% +appropriate testing to be done i mean if + + + align:start position:0% +appropriate testing to be done i mean if +a patient comes to me as an + + align:start position:0% +a patient comes to me as an + + + align:start position:0% +a patient comes to me as an +endocrinologist says i want growth + + align:start position:0% +endocrinologist says i want growth + + + align:start position:0% +endocrinologist says i want growth +hormone testing + + align:start position:0% +hormone testing + + + align:start position:0% +hormone testing +i know not to do growth hormone testing + + align:start position:0% +i know not to do growth hormone testing + + + align:start position:0% +i know not to do growth hormone testing +and everybody asks because there's a + + align:start position:0% +and everybody asks because there's a + + + align:start position:0% +and everybody asks because there's a +significant + + align:start position:0% +significant + + + align:start position:0% +significant +false positive rate and that we end up + + align:start position:0% +false positive rate and that we end up + + + align:start position:0% +false positive rate and that we end up +treating a whole bunch of people + + align:start position:0% +treating a whole bunch of people + + + align:start position:0% +treating a whole bunch of people +uh with growth hormone for no reason + + align:start position:0% +uh with growth hormone for no reason + + + align:start position:0% +uh with growth hormone for no reason +that that's that and that's the whole + + align:start position:0% +that that's that and that's the whole + + + align:start position:0% +that that's that and that's the whole +point of having uh an expert + + align:start position:0% +point of having uh an expert + + + align:start position:0% +point of having uh an expert +as part of the loop and what i'm saying + + align:start position:0% +as part of the loop and what i'm saying + + + align:start position:0% +as part of the loop and what i'm saying +is this is telling us there's a demand + + align:start position:0% +is this is telling us there's a demand + + + align:start position:0% +is this is telling us there's a demand +and the medical system is failing + + align:start position:0% + + + + align:start position:0% + +so here's the conventional view of + + align:start position:0% +so here's the conventional view of + + + align:start position:0% +so here's the conventional view of +genetic information management's worth + + align:start position:0% +genetic information management's worth + + + align:start position:0% +genetic information management's worth +going through it + + align:start position:0% +going through it + + + align:start position:0% +going through it +they you can think of disorders being + + align:start position:0% +they you can think of disorders being + + + align:start position:0% +they you can think of disorders being +single gene or chromosomal major gene + + align:start position:0% +single gene or chromosomal major gene + + + align:start position:0% +single gene or chromosomal major gene +multi factorial or these complex traits + + align:start position:0% +multi factorial or these complex traits + + + align:start position:0% +multi factorial or these complex traits +complex multi-factorial + + align:start position:0% +complex multi-factorial + + + align:start position:0% +complex multi-factorial +and the conventional view of how this + + align:start position:0% +and the conventional view of how this + + + align:start position:0% +and the conventional view of how this +should be used is + + align:start position:0% +should be used is + + + align:start position:0% +should be used is +in primary care the point would be to + + align:start position:0% +in primary care the point would be to + + + align:start position:0% +in primary care the point would be to +recognize signs and symptoms make + + align:start position:0% +recognize signs and symptoms make + + + align:start position:0% +recognize signs and symptoms make +referrals support family longitudinal + + align:start position:0% +referrals support family longitudinal + + + align:start position:0% +referrals support family longitudinal +care + + align:start position:0% +care + + + align:start position:0% +care +the primary care should appreciate the + + align:start position:0% +the primary care should appreciate the + + + align:start position:0% +the primary care should appreciate the +role of family history arrange testing + + align:start position:0% +role of family history arrange testing + + + align:start position:0% +role of family history arrange testing +referrals specialists as needed provide + + align:start position:0% +referrals specialists as needed provide + + + align:start position:0% +referrals specialists as needed provide +longitudinal care + + align:start position:0% +longitudinal care + + + align:start position:0% +longitudinal care +and for complex uh traits use of genetic + + align:start position:0% +and for complex uh traits use of genetic + + + align:start position:0% +and for complex uh traits use of genetic +tests to guide prevention treatment the + + align:start position:0% +tests to guide prevention treatment the + + + align:start position:0% +tests to guide prevention treatment the +specialist would manage specific + + align:start position:0% +specialist would manage specific + + + align:start position:0% +specialist would manage specific +problems + + align:start position:0% +problems + + + align:start position:0% +problems +they would diagnose and manage uh + + align:start position:0% +they would diagnose and manage uh + + + align:start position:0% +they would diagnose and manage uh +system-specific problems and then use + + align:start position:0% +system-specific problems and then use + + + align:start position:0% +system-specific problems and then use +also genetic tests to guide uh prevent + + align:start position:0% +also genetic tests to guide uh prevent + + + align:start position:0% +also genetic tests to guide uh prevent +and treat and medical geneticists the + + align:start position:0% +and treat and medical geneticists the + + + align:start position:0% +and treat and medical geneticists the +role there is + + align:start position:0% +role there is + + + align:start position:0% +role there is +counseling longitudinal care + + align:start position:0% +counseling longitudinal care + + + align:start position:0% +counseling longitudinal care +advice on interpretation of test results + + align:start position:0% +advice on interpretation of test results + + + align:start position:0% +advice on interpretation of test results +and + + align:start position:0% +and + + + align:start position:0% +and +a reservoir of knowledge of handling of + + align:start position:0% +a reservoir of knowledge of handling of + + + align:start position:0% +a reservoir of knowledge of handling of +complex uh cases but i just told you + + align:start position:0% +complex uh cases but i just told you + + + align:start position:0% +complex uh cases but i just told you +that the medical genesis have largely + + align:start position:0% +that the medical genesis have largely + + + align:start position:0% +that the medical genesis have largely +not + + align:start position:0% +not + + + align:start position:0% +not +met this role + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +is there a different role + + align:start position:0% +is there a different role + + + align:start position:0% +is there a different role +what to do is there a is there a medical + + align:start position:0% +what to do is there a is there a medical + + + align:start position:0% +what to do is there a is there a medical +genomicist + + align:start position:0% +genomicist + + + align:start position:0% +genomicist +what do you think + + align:start position:0% +what do you think + + + align:start position:0% +what do you think +is that a reasonable specialty or + + align:start position:0% +is that a reasonable specialty or + + + align:start position:0% +is that a reasonable specialty or +is that the wrong answer + + align:start position:0% + + + + align:start position:0% + +someone would you if you were + + align:start position:0% +someone would you if you were + + + align:start position:0% +someone would you if you were +if you wanted good preventive care + + align:start position:0% +if you wanted good preventive care + + + align:start position:0% +if you wanted good preventive care +and you wanted someone who would give + + align:start position:0% +and you wanted someone who would give + + + align:start position:0% +and you wanted someone who would give +you appropriate counseling about either + + align:start position:0% +you appropriate counseling about either + + + align:start position:0% +you appropriate counseling about either +lifestyle changes + + align:start position:0% +lifestyle changes + + + align:start position:0% +lifestyle changes +or appropriate uh + + align:start position:0% +or appropriate uh + + + align:start position:0% +or appropriate uh +drugs that you need to consider + + align:start position:0% +drugs that you need to consider + + + align:start position:0% +drugs that you need to consider +or a specific for the diagnostic tests + + align:start position:0% +or a specific for the diagnostic tests + + + align:start position:0% +or a specific for the diagnostic tests +that you have to do for all possible + + align:start position:0% +that you have to do for all possible + + + align:start position:0% +that you have to do for all possible +genetically influenced diseases + + align:start position:0% +genetically influenced diseases + + + align:start position:0% +genetically influenced diseases +what kind of person would you would you + + align:start position:0% +what kind of person would you would you + + + align:start position:0% +what kind of person would you would you +want to go to + + align:start position:0% + + + + align:start position:0% + +any ideas + + align:start position:0% + + + + align:start position:0% + +so your first reaction is primary care + + align:start position:0% +so your first reaction is primary care + + + align:start position:0% +so your first reaction is primary care +let's um does + + align:start position:0% +let's um does + + + align:start position:0% +let's um does +do primary care practitioners currently + + align:start position:0% +do primary care practitioners currently + + + align:start position:0% +do primary care practitioners currently +know about any of this stuff no + + align:start position:0% +know about any of this stuff no + + + align:start position:0% +know about any of this stuff no +so + + align:start position:0% +so + + + align:start position:0% +so +someone would give them a very simple + + align:start position:0% +someone would give them a very simple + + + align:start position:0% +someone would give them a very simple +explanation so you know someone else's + + align:start position:0% +explanation so you know someone else's + + + align:start position:0% +explanation so you know someone else's +testing goes up sort of what it means + + align:start position:0% +testing goes up sort of what it means + + + align:start position:0% +testing goes up sort of what it means +and they can tell you what it means to + + align:start position:0% +and they can tell you what it means to + + + align:start position:0% +and they can tell you what it means to +manage that + + align:start position:0% +manage that + + + align:start position:0% +manage that +so let's let's let's do this slowly with + + align:start position:0% +so let's let's let's do this slowly with + + + align:start position:0% +so let's let's let's do this slowly with +feeling because you're now the czar of + + align:start position:0% +feeling because you're now the czar of + + + align:start position:0% +feeling because you're now the czar of +medicine + + align:start position:0% +medicine + + + align:start position:0% +medicine +in in um and + + align:start position:0% +in in um and + + + align:start position:0% +in in um and +or you're trying to start a company + + align:start position:0% +or you're trying to start a company + + + align:start position:0% +or you're trying to start a company +in um in this area in the united states + + align:start position:0% +in um in this area in the united states + + + align:start position:0% +in um in this area in the united states +in 2004 + + align:start position:0% +in 2004 + + + align:start position:0% +in 2004 +who's going to actually do this job + + align:start position:0% +who's going to actually do this job + + + align:start position:0% +who's going to actually do this job +well i mean i'd say i i think the idea + + align:start position:0% +well i mean i'd say i i think the idea + + + align:start position:0% +well i mean i'd say i i think the idea +of going to any one single person + + align:start position:0% +of going to any one single person + + + align:start position:0% +of going to any one single person +whether it's specialists genomics + + align:start position:0% +whether it's specialists genomics + + + align:start position:0% +whether it's specialists genomics +geneticists or primary care + + align:start position:0% +geneticists or primary care + + + align:start position:0% +geneticists or primary care +i think there's a wrong approach i don't + + align:start position:0% +i think there's a wrong approach i don't + + + align:start position:0% +i think there's a wrong approach i don't +think any one person + + align:start position:0% +think any one person + + + align:start position:0% +think any one person +just + + align:start position:0% +just + + + align:start position:0% +just +in their specific roles can address + + align:start position:0% +in their specific roles can address + + + align:start position:0% +in their specific roles can address +especially as you move down that + + align:start position:0% + + + + align:start position:0% + +so what do you do + + align:start position:0% +so what do you do + + + align:start position:0% +so what do you do +well we have a bunch of patients we know + + align:start position:0% +well we have a bunch of patients we know + + + align:start position:0% +well we have a bunch of patients we know +that there's a large number of people + + align:start position:0% +that there's a large number of people + + + align:start position:0% +that there's a large number of people +who die of complications of that type 2 + + align:start position:0% +who die of complications of that type 2 + + + align:start position:0% +who die of complications of that type 2 +diabetes and it's exploding we know + + align:start position:0% +diabetes and it's exploding we know + + + align:start position:0% +diabetes and it's exploding we know +there's a large cancer burden + + align:start position:0% +there's a large cancer burden + + + align:start position:0% +there's a large cancer burden +i know there's a large cardiovascular + + align:start position:0% +i know there's a large cardiovascular + + + align:start position:0% +i know there's a large cardiovascular +disease burden how are and we know that + + align:start position:0% +disease burden how are and we know that + + + align:start position:0% +disease burden how are and we know that +some component of all diseases is + + align:start position:0% +some component of all diseases is + + + align:start position:0% +some component of all diseases is +complex is in fact down at the bottom + + align:start position:0% +complex is in fact down at the bottom + + + align:start position:0% +complex is in fact down at the bottom +so what do we do + + align:start position:0% +so what do we do + + + align:start position:0% +so what do we do +so i think rather than having medical + + align:start position:0% +so i think rather than having medical + + + align:start position:0% +so i think rather than having medical +genomics it would be nice to have a + + align:start position:0% +genomics it would be nice to have a + + + align:start position:0% +genomics it would be nice to have a +type of physician who + + align:start position:0% +type of physician who + + + align:start position:0% +type of physician who +organized + + align:start position:0% +organized + + + align:start position:0% +organized +the different levels of care into like a + + align:start position:0% +the different levels of care into like a + + + align:start position:0% +the different levels of care into like a +teenager's approach to be able to make a + + align:start position:0% +teenager's approach to be able to make a + + + align:start position:0% +teenager's approach to be able to make a +team-based approach to address it so + + align:start position:0% +team-based approach to address it so + + + align:start position:0% +team-based approach to address it so +that you have like the traditional + + align:start position:0% +that you have like the traditional + + + align:start position:0% +that you have like the traditional +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and you know and maybe + + align:start position:0% +and you know and maybe + + + align:start position:0% +and you know and maybe +the genomicist would be appropriate for + + align:start position:0% +the genomicist would be appropriate for + + + align:start position:0% +the genomicist would be appropriate for +handling the genetic aspects + + align:start position:0% +handling the genetic aspects + + + align:start position:0% +handling the genetic aspects +you know in collaboration with but you + + align:start position:0% +you know in collaboration with but you + + + align:start position:0% +you know in collaboration with but you +have somebody who + + align:start position:0% +have somebody who + + + align:start position:0% +have somebody who +is seeing the patient + + align:start position:0% +is seeing the patient + + + align:start position:0% +is seeing the patient +outside of their regular pcp right + + align:start position:0% +outside of their regular pcp right + + + align:start position:0% +outside of their regular pcp right +who can you know who can introduce with + + align:start position:0% +who can you know who can introduce with + + + align:start position:0% +who can you know who can introduce with +the latest technologies along with the + + align:start position:0% +the latest technologies along with the + + + align:start position:0% +the latest technologies along with the +traditional therapies and communicate + + align:start position:0% +traditional therapies and communicate + + + align:start position:0% +traditional therapies and communicate +across so basically a + + align:start position:0% +across so basically a + + + align:start position:0% +across so basically a +someone who's a journalist in medicine + + align:start position:0% +someone who's a journalist in medicine + + + align:start position:0% +someone who's a journalist in medicine +but a specialist about + + align:start position:0% +but a specialist about + + + align:start position:0% +but a specialist about +inherited diseases and complex diseases + + align:start position:0% +inherited diseases and complex diseases + + + align:start position:0% +inherited diseases and complex diseases +and also a team + + align:start position:0% +and also a team + + + align:start position:0% +and also a team +a a team communicator coordinator + + align:start position:0% +a a team communicator coordinator + + + align:start position:0% +a a team communicator coordinator +right so that for each patient you've + + align:start position:0% +right so that for each patient you've + + + align:start position:0% +right so that for each patient you've +got one person + + align:start position:0% +got one person + + + align:start position:0% +got one person +um who's + + align:start position:0% +um who's + + + align:start position:0% +um who's +you know not having to worry about the + + align:start position:0% +you know not having to worry about the + + + align:start position:0% +you know not having to worry about the +occasional sniffle here without like the + + align:start position:0% +occasional sniffle here without like the + + + align:start position:0% +occasional sniffle here without like the +pcb but also was focused on a bigger + + align:start position:0% +pcb but also was focused on a bigger + + + align:start position:0% +pcb but also was focused on a bigger +picture than maybe the specialist or one + + align:start position:0% +picture than maybe the specialist or one + + + align:start position:0% +picture than maybe the specialist or one +of the geneticists + + align:start position:0% +of the geneticists + + + align:start position:0% +of the geneticists +glad i think it's very realistic to have + + align:start position:0% +glad i think it's very realistic to have + + + align:start position:0% +glad i think it's very realistic to have +a team like i also had a team of + + align:start position:0% +a team like i also had a team of + + + align:start position:0% +a team like i also had a team of +specialists around me all the time like + + align:start position:0% +specialists around me all the time like + + + align:start position:0% +specialists around me all the time like +doing stuff for me i think it's you know + + align:start position:0% +doing stuff for me i think it's you know + + + align:start position:0% +doing stuff for me i think it's you know +the reality is you're going to have + + align:start position:0% +the reality is you're going to have + + + align:start position:0% +the reality is you're going to have +at most one person who knows feeling + + align:start position:0% +at most one person who knows feeling + + + align:start position:0% +at most one person who knows feeling +about your health and any kind of + + align:start position:0% +about your health and any kind of + + + align:start position:0% +about your health and any kind of +ongoing basis and that person should be + + align:start position:0% +ongoing basis and that person should be + + + align:start position:0% +ongoing basis and that person should be +the counselor that lets you know things + + align:start position:0% +the counselor that lets you know things + + + align:start position:0% +the counselor that lets you know things +about lifestyle things about you know + + align:start position:0% +about lifestyle things about you know + + + align:start position:0% +about lifestyle things about you know +preventive care and they should have + + align:start position:0% +preventive care and they should have + + + align:start position:0% +preventive care and they should have +information including information to + + align:start position:0% +information including information to + + + align:start position:0% +information including information to +help give you advice about your + + align:start position:0% +help give you advice about your + + + align:start position:0% +help give you advice about your +particular life scholarships you should + + align:start position:0% +particular life scholarships you should + + + align:start position:0% +particular life scholarships you should +make and that should be the primary care + + align:start position:0% +make and that should be the primary care + + + align:start position:0% +make and that should be the primary care +position so i think that it's + + align:start position:0% +position so i think that it's + + + align:start position:0% +position so i think that it's +it's going to be really hard to have + + align:start position:0% +it's going to be really hard to have + + + align:start position:0% +it's going to be really hard to have +like a lot of people around these + + align:start position:0% +like a lot of people around these + + + align:start position:0% +like a lot of people around these +specialists like generosity's giving you + + align:start position:0% +specialists like generosity's giving you + + + align:start position:0% +specialists like generosity's giving you +this sort of preventive + + align:start position:0% +this sort of preventive + + + align:start position:0% +this sort of preventive +care type information because they don't + + align:start position:0% +care type information because they don't + + + align:start position:0% +care type information because they don't +know you that well so you see the + + align:start position:0% +know you that well so you see the + + + align:start position:0% +know you that well so you see the +primary care practitioner especially i + + align:start position:0% +primary care practitioner especially i + + + align:start position:0% +primary care practitioner especially i +mean you know with more and more of + + align:start position:0% +mean you know with more and more of + + + align:start position:0% +mean you know with more and more of +these genomics tests come online like + + align:start position:0% +these genomics tests come online like + + + align:start position:0% +these genomics tests come online like +looking at cancer and microarrays you're + + align:start position:0% +looking at cancer and microarrays you're + + + align:start position:0% +looking at cancer and microarrays you're +just gonna you're gonna need people who + + align:start position:0% +just gonna you're gonna need people who + + + align:start position:0% +just gonna you're gonna need people who +know about the techniques you know about + + align:start position:0% +know about the techniques you know about + + + align:start position:0% +know about the techniques you know about +the methods and you can help help the + + align:start position:0% +the methods and you can help help the + + + align:start position:0% +the methods and you can help help the +physicians and interpret it i mean + + align:start position:0% +physicians and interpret it i mean + + + align:start position:0% +physicians and interpret it i mean +there's gonna be a role for them they're + + align:start position:0% +there's gonna be a role for them they're + + + align:start position:0% +there's gonna be a role for them they're +gonna be you know we're seeing already + + align:start position:0% +gonna be you know we're seeing already + + + align:start position:0% +gonna be you know we're seeing already +there's gonna be an explosion of you + + align:start position:0% +there's gonna be an explosion of you + + + align:start position:0% +there's gonna be an explosion of you +know you know on the coaching movements + + align:start position:0% +know you know on the coaching movements + + + align:start position:0% +know you know on the coaching movements +and all this stuff you're going to need + + align:start position:0% +and all this stuff you're going to need + + + align:start position:0% +and all this stuff you're going to need +to have people who you know the + + align:start position:0% +to have people who you know the + + + align:start position:0% +to have people who you know the +techniques who can help the primary care + + align:start position:0% +techniques who can help the primary care + + + align:start position:0% +techniques who can help the primary care +and yet and + + align:start position:0% +and yet and + + + align:start position:0% +and yet and +i think we're and yeah so that's so + + align:start position:0% +i think we're and yeah so that's so + + + align:start position:0% +i think we're and yeah so that's so +there's i think true they're absolutely + + align:start position:0% +there's i think true they're absolutely + + + align:start position:0% +there's i think true they're absolutely +true what you both said on one hand it's + + align:start position:0% +true what you both said on one hand it's + + + align:start position:0% +true what you both said on one hand it's +unlikely that we will have swarms of + + align:start position:0% +unlikely that we will have swarms of + + + align:start position:0% +unlikely that we will have swarms of +people uh worrying about us and yet + + align:start position:0% +people uh worrying about us and yet + + + align:start position:0% +people uh worrying about us and yet +um there is gonna be this explosion and + + align:start position:0% +um there is gonna be this explosion and + + + align:start position:0% +um there is gonna be this explosion and +no one person i mean it's already pretty + + align:start position:0% +no one person i mean it's already pretty + + + align:start position:0% +no one person i mean it's already pretty +hard to be a good + + align:start position:0% +hard to be a good + + + align:start position:0% +hard to be a good +primary care practitioner with knowledge + + align:start position:0% +primary care practitioner with knowledge + + + align:start position:0% +primary care practitioner with knowledge +circa 1990 + + align:start position:0% +circa 1990 + + + align:start position:0% +circa 1990 +how are they going to + + align:start position:0% +how are they going to + + + align:start position:0% +how are they going to +do that any ideas + + align:start position:0% +do that any ideas + + + align:start position:0% +do that any ideas +how we're going to + + align:start position:0% +how we're going to + + + align:start position:0% +how we're going to +so + + align:start position:0% +so + + + align:start position:0% +so +so you have + + align:start position:0% +so you have + + + align:start position:0% +so you have +operationalize what you were suggesting + + align:start position:0% +operationalize what you were suggesting + + + align:start position:0% +operationalize what you were suggesting +can you + + align:start position:0% +can you + + + align:start position:0% +can you +i mean that that you might you might + + align:start position:0% +i mean that that you might you might + + + align:start position:0% +i mean that that you might you might +have in a hospital + + align:start position:0% +have in a hospital + + + align:start position:0% +have in a hospital +that these primary care physicians can + + align:start position:0% +that these primary care physicians can + + + align:start position:0% +that these primary care physicians can +you know call off or refer a patient to + + align:start position:0% +you know call off or refer a patient to + + + align:start position:0% +you know call off or refer a patient to +help interpret things + + align:start position:0% +help interpret things + + + align:start position:0% +help interpret things +but if it's part of primary care if it's + + align:start position:0% +but if it's part of primary care if it's + + + align:start position:0% +but if it's part of primary care if it's +primary care so everybody i mean + + align:start position:0% +primary care so everybody i mean + + + align:start position:0% +primary care so everybody i mean +we're all going to unfortunately + + align:start position:0% +we're all going to unfortunately + + + align:start position:0% +we're all going to unfortunately +unless some one of us is a major + + align:start position:0% +unless some one of us is a major + + + align:start position:0% +unless some one of us is a major +messianic figure going to die um + + align:start position:0% +messianic figure going to die um + + + align:start position:0% +messianic figure going to die um +for one disease or other so we're at + + align:start position:0% +for one disease or other so we're at + + + align:start position:0% +for one disease or other so we're at +risk and probably and hopefully will not + + align:start position:0% +risk and probably and hopefully will not + + + align:start position:0% +risk and probably and hopefully will not +be + + align:start position:0% +be + + + align:start position:0% +be +a bus hitting us so it's going to be + + align:start position:0% +a bus hitting us so it's going to be + + + align:start position:0% +a bus hitting us so it's going to be +something that's going to become uh + + align:start position:0% +something that's going to become uh + + + align:start position:0% +something that's going to become uh +interaction to the environment and our + + align:start position:0% +interaction to the environment and our + + + align:start position:0% +interaction to the environment and our +genes + + align:start position:0% +genes + + + align:start position:0% +genes +so who's going to know + + align:start position:0% +so who's going to know + + + align:start position:0% +so who's going to know +uh so that's for all of us so basically + + align:start position:0% +uh so that's for all of us so basically + + + align:start position:0% +uh so that's for all of us so basically +we need that + + align:start position:0% +we need that + + + align:start position:0% +we need that +information unless we don't want + + align:start position:0% +information unless we don't want + + + align:start position:0% +information unless we don't want +information for every one of us so who + + align:start position:0% +information for every one of us so who + + + align:start position:0% +information for every one of us so who +so just it's not going to be + + align:start position:0% +so just it's not going to be + + + align:start position:0% +so just it's not going to be +um hey um i have an interesting problem + + align:start position:0% +um hey um i have an interesting problem + + + align:start position:0% +um hey um i have an interesting problem +it's part routine care i think + + align:start position:0% +it's part routine care i think + + + align:start position:0% +it's part routine care i think +everybody needs to be + + align:start position:0% +everybody needs to be + + + align:start position:0% +everybody needs to be +like a department of + + align:start position:0% +like a department of + + + align:start position:0% +like a department of +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +the process in the field who's going to + + align:start position:0% +the process in the field who's going to + + + align:start position:0% +the process in the field who's going to +be the guy or girl + + align:start position:0% +be the guy or girl + + + align:start position:0% +be the guy or girl +who's going to be + + align:start position:0% +who's going to be + + + align:start position:0% +who's going to be +providing that knowledge + + align:start position:0% +providing that knowledge + + + align:start position:0% +providing that knowledge +either as a primary care practitioner + + align:start position:0% +either as a primary care practitioner + + + align:start position:0% +either as a primary care practitioner +or + + align:start position:0% +or + + + align:start position:0% +or +to the primary care practitioner + + align:start position:0% + + + + align:start position:0% + +so here's some ideas i had + + align:start position:0% +so here's some ideas i had + + + align:start position:0% +so here's some ideas i had +you know your ideas by the way are as + + align:start position:0% +you know your ideas by the way are as + + + align:start position:0% +you know your ideas by the way are as +good as mine and i want to tell you this + + align:start position:0% +good as mine and i want to tell you this + + + align:start position:0% +good as mine and i want to tell you this +is actually the central i mean this + + align:start position:0% +is actually the central i mean this + + + align:start position:0% +is actually the central i mean this +course is about genomic medicine + + align:start position:0% +course is about genomic medicine + + + align:start position:0% +course is about genomic medicine +and + + align:start position:0% +and + + + align:start position:0% +and +i think this is a central conundrum + + align:start position:0% +i think this is a central conundrum + + + align:start position:0% +i think this is a central conundrum +how + + align:start position:0% +how + + + align:start position:0% +how +there is no plan right now how to bring + + align:start position:0% +there is no plan right now how to bring + + + align:start position:0% +there is no plan right now how to bring +all of this into um + + align:start position:0% +all of this into um + + + align:start position:0% +all of this into um +into the field and i can tell you in + + align:start position:0% +into the field and i can tell you in + + + align:start position:0% +into the field and i can tell you in +pediatric endocrinology + + align:start position:0% +pediatric endocrinology + + + align:start position:0% +pediatric endocrinology +we're not even + + align:start position:0% +we're not even + + + align:start position:0% +we're not even +ordering the + + align:start position:0% +ordering the + + + align:start position:0% +ordering the +um autosomal dominant + + align:start position:0% +um autosomal dominant + + + align:start position:0% +um autosomal dominant +well-understood highly penetrated single + + align:start position:0% +well-understood highly penetrated single + + + align:start position:0% +well-understood highly penetrated single +genes that we know about because of the + + align:start position:0% +genes that we know about because of the + + + align:start position:0% +genes that we know about because of the +educational problems let alone all these + + align:start position:0% +educational problems let alone all these + + + align:start position:0% +educational problems let alone all these +other + + align:start position:0% +other + + + align:start position:0% +other +complex diseases + + align:start position:0% +complex diseases + + + align:start position:0% +complex diseases +so + + align:start position:0% +so + + + align:start position:0% +so +any idea that you have + + align:start position:0% +any idea that you have + + + align:start position:0% +any idea that you have +could be + + align:start position:0% +could be + + + align:start position:0% +could be +of great interest to + + align:start position:0% +of great interest to + + + align:start position:0% +of great interest to +our system or to a company if you could + + align:start position:0% +our system or to a company if you could + + + align:start position:0% +our system or to a company if you could +actually figure out how to do this right + + align:start position:0% + + + + align:start position:0% + +i mean it's never going to be market + + align:start position:0% +i mean it's never going to be market + + + align:start position:0% +i mean it's never going to be market +driven you know i mean right now a lot + + align:start position:0% +driven you know i mean right now a lot + + + align:start position:0% +driven you know i mean right now a lot +of people are still at research and + + align:start position:0% +of people are still at research and + + + align:start position:0% +of people are still at research and +influx and when they're really good + + align:start position:0% +influx and when they're really good + + + align:start position:0% +influx and when they're really good +tests and really good results come + + align:start position:0% +tests and really good results come + + + align:start position:0% +tests and really good results come +online and generate practice papers + + align:start position:0% + + + + align:start position:0% + +you know patients that you're going to + + align:start position:0% +you know patients that you're going to + + + align:start position:0% +you know patients that you're going to +start demanding + + align:start position:0% +start demanding + + + align:start position:0% +start demanding +and yet but that's the problem for + + align:start position:0% +and yet but that's the problem for + + + align:start position:0% +and yet but that's the problem for +instance prostate specific antigen + + align:start position:0% +instance prostate specific antigen + + + align:start position:0% +instance prostate specific antigen +um + + align:start position:0% +um + + + align:start position:0% +um +done wrongly gets a whole point of poor + + align:start position:0% +done wrongly gets a whole point of poor + + + align:start position:0% +done wrongly gets a whole point of poor +guys get their prostates removed for + + align:start position:0% +guys get their prostates removed for + + + align:start position:0% +guys get their prostates removed for +nothing + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +yeah and so + + align:start position:0% +yeah and so + + + align:start position:0% +yeah and so +that's the problem + + align:start position:0% +that's the problem + + + align:start position:0% +that's the problem +and + + align:start position:0% +and + + + align:start position:0% +and +and as i explained to you uh in my first + + align:start position:0% +and as i explained to you uh in my first + + + align:start position:0% +and as i explained to you uh in my first +lecture there's 7 000 articles just on + + align:start position:0% +lecture there's 7 000 articles just on + + + align:start position:0% +lecture there's 7 000 articles just on +the appropriate use of the prostate + + align:start position:0% +the appropriate use of the prostate + + + align:start position:0% +the appropriate use of the prostate +specific antigen + + align:start position:0% +specific antigen + + + align:start position:0% +specific antigen +we have now + + align:start position:0% +we have now + + + align:start position:0% +we have now +30 000 genes to worry about + + align:start position:0% +30 000 genes to worry about + + + align:start position:0% +30 000 genes to worry about +and + + align:start position:0% +and + + + align:start position:0% +and +what you know what are the right cutoffs + + align:start position:0% +what you know what are the right cutoffs + + + align:start position:0% +what you know what are the right cutoffs +and + + align:start position:0% +and + + + align:start position:0% +and +let's be optimistic we can actually get + + align:start position:0% +let's be optimistic we can actually get + + + align:start position:0% +let's be optimistic we can actually get +the optimal answers for these no one + + align:start position:0% +the optimal answers for these no one + + + align:start position:0% +the optimal answers for these no one +individual i can think + + align:start position:0% +individual i can think + + + align:start position:0% +individual i can think +can can um actually solve it so you're + + align:start position:0% +can can um actually solve it so you're + + + align:start position:0% +can can um actually solve it so you're +absolutely right it will be market + + align:start position:0% +absolutely right it will be market + + + align:start position:0% +absolutely right it will be market +driven that's certainly true the + + align:start position:0% +driven that's certainly true the + + + align:start position:0% +driven that's certainly true the +question is + + align:start position:0% +question is + + + align:start position:0% +question is +how will the market solve that problem + + align:start position:0% +how will the market solve that problem + + + align:start position:0% +how will the market solve that problem +and i'm claiming there are companies out + + align:start position:0% +and i'm claiming there are companies out + + + align:start position:0% +and i'm claiming there are companies out +there that will solve that and + + align:start position:0% +there that will solve that and + + + align:start position:0% +there that will solve that and +either going to be inspired us by ideas + + align:start position:0% +either going to be inspired us by ideas + + + align:start position:0% +either going to be inspired us by ideas +similar to ones we're going to + + align:start position:0% +similar to ones we're going to + + + align:start position:0% +similar to ones we're going to +articulate today or by other ideas so + + align:start position:0% +articulate today or by other ideas so + + + align:start position:0% +articulate today or by other ideas so +all i'm calling for is thought about + + align:start position:0% +all i'm calling for is thought about + + + align:start position:0% +all i'm calling for is thought about +this so one was internet-enabled triage + + align:start position:0% +this so one was internet-enabled triage + + + align:start position:0% +this so one was internet-enabled triage +specialist basically you feed your + + align:start position:0% +specialist basically you feed your + + + align:start position:0% +specialist basically you feed your +genome to essentially a service on the + + align:start position:0% +genome to essentially a service on the + + + align:start position:0% +genome to essentially a service on the +internet + + align:start position:0% +internet + + + align:start position:0% +internet +and + + align:start position:0% +and + + + align:start position:0% +and +they take whatever the primary care + + align:start position:0% +they take whatever the primary care + + + align:start position:0% +they take whatever the primary care +physician says and they basically you + + align:start position:0% +physician says and they basically you + + + align:start position:0% +physician says and they basically you +know in india or somewhere else um + + align:start position:0% +know in india or somewhere else um + + + align:start position:0% +know in india or somewhere else um +provide uh provide you with your risk + + align:start position:0% +provide uh provide you with your risk + + + align:start position:0% +provide uh provide you with your risk +profile the next steps for you to take + + align:start position:0% +profile the next steps for you to take + + + align:start position:0% +profile the next steps for you to take +that's one possibility + + align:start position:0% +that's one possibility + + + align:start position:0% +that's one possibility +so you check each patient the door for + + align:start position:0% +so you check each patient the door for + + + align:start position:0% +so you check each patient the door for +inheritable genetic or epigenetic + + align:start position:0% +inheritable genetic or epigenetic + + + align:start position:0% +inheritable genetic or epigenetic +phenomena + + align:start position:0% +phenomena + + + align:start position:0% +phenomena +a parallel system that's um + + align:start position:0% +a parallel system that's um + + + align:start position:0% +a parallel system that's um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +essentially a fly on the wall during a + + align:start position:0% +essentially a fly on the wall during a + + + align:start position:0% +essentially a fly on the wall during a +mental interview + + align:start position:0% + + + + align:start position:0% + +provide decision supports + + align:start position:0% +provide decision supports + + + align:start position:0% +provide decision supports +and this could be a person or more + + align:start position:0% +and this could be a person or more + + + align:start position:0% +and this could be a person or more +likely + + align:start position:0% +likely + + + align:start position:0% +likely +a computer program + + align:start position:0% +a computer program + + + align:start position:0% +a computer program +but it's going to be a damn have to be a + + align:start position:0% +but it's going to be a damn have to be a + + + align:start position:0% +but it's going to be a damn have to be a +damn good computer program to be able to + + align:start position:0% +damn good computer program to be able to + + + align:start position:0% +damn good computer program to be able to +do that but + + align:start position:0% +do that but + + + align:start position:0% +do that but +no + + align:start position:0% +no + + + align:start position:0% +no +i was involved in knowledge + + align:start position:0% +i was involved in knowledge + + + align:start position:0% +i was involved in knowledge +representation knowledge based systems + + align:start position:0% +representation knowledge based systems + + + align:start position:0% +representation knowledge based systems +in the 80s when i do my thesis + + align:start position:0% +in the 80s when i do my thesis + + + align:start position:0% +in the 80s when i do my thesis +but there really wasn't any good + + align:start position:0% +but there really wasn't any good + + + align:start position:0% +but there really wasn't any good +motivation for it because in the end + + align:start position:0% +motivation for it because in the end + + + align:start position:0% +motivation for it because in the end +doctors know how to + + align:start position:0% +doctors know how to + + + align:start position:0% +doctors know how to +diagnose acid-base problems + + align:start position:0% +diagnose acid-base problems + + + align:start position:0% +diagnose acid-base problems +but doctors will never + + align:start position:0% +but doctors will never + + + align:start position:0% +but doctors will never +never be able to do this so this is a + + align:start position:0% +never be able to do this so this is a + + + align:start position:0% +never be able to do this so this is a +true motivation i believe for automated + + align:start position:0% +true motivation i believe for automated + + + align:start position:0% +true motivation i believe for automated +decision support + + align:start position:0% + + + + align:start position:0% + +the alternative is just to redo the + + align:start position:0% +the alternative is just to redo the + + + align:start position:0% +the alternative is just to redo the +curriculum in a major way + + align:start position:0% +curriculum in a major way + + + align:start position:0% +curriculum in a major way +and even so to teach students how to use + + align:start position:0% +and even so to teach students how to use + + + align:start position:0% +and even so to teach students how to use +the electronic resources in uh near real + + align:start position:0% +the electronic resources in uh near real + + + align:start position:0% +the electronic resources in uh near real +time + + align:start position:0% +time + + + align:start position:0% +time +i see no because no one's gonna be able + + align:start position:0% +i see no because no one's gonna be able + + + align:start position:0% +i see no because no one's gonna be able +to keep this in their head + + align:start position:0% +to keep this in their head + + + align:start position:0% +to keep this in their head +i think if the last one i think would + + align:start position:0% +i think if the last one i think would + + + align:start position:0% +i think if the last one i think would +require + + align:start position:0% +require + + + align:start position:0% +require +such simplification of like outputs that + + align:start position:0% +such simplification of like outputs that + + + align:start position:0% +such simplification of like outputs that +you you know + + align:start position:0% +you you know + + + align:start position:0% +you you know +in terms of like feeding and you know + + align:start position:0% +in terms of like feeding and you know + + + align:start position:0% +in terms of like feeding and you know +maintenance but not how many + + align:start position:0% +maintenance but not how many + + + align:start position:0% +maintenance but not how many +but you know like the way you get pdt's + + align:start position:0% +but you know like the way you get pdt's + + + align:start position:0% +but you know like the way you get pdt's +and all these other things + + align:start position:0% +and all these other things + + + align:start position:0% +and all these other things +because that's not right right but it + + align:start position:0% +because that's not right right but it + + + align:start position:0% +because that's not right right but it +would not be a number the way for um + + align:start position:0% +would not be a number the way for um + + + align:start position:0% +would not be a number the way for um +when i was talking about um + + align:start position:0% +when i was talking about um + + + align:start position:0% +when i was talking about um +spitting on when you're feeding the + + align:start position:0% +spitting on when you're feeding the + + + align:start position:0% +spitting on when you're feeding the +genome in science the answer would not + + align:start position:0% +genome in science the answer would not + + + align:start position:0% +genome in science the answer would not +be you know these are the levels of your + + align:start position:0% +be you know these are the levels of your + + + align:start position:0% +be you know these are the levels of your +various things would be + + align:start position:0% +various things would be + + + align:start position:0% +various things would be +you will have a 30 increased risk for + + align:start position:0% +you will have a 30 increased risk for + + + align:start position:0% +you will have a 30 increased risk for +prostate cancer + + align:start position:0% +prostate cancer + + + align:start position:0% +prostate cancer +the following test is the right thing to + + align:start position:0% +the following test is the right thing to + + + align:start position:0% +the following test is the right thing to +do that kind of thing + + align:start position:0% +do that kind of thing + + + align:start position:0% +do that kind of thing +because no again no primary care + + align:start position:0% +because no again no primary care + + + align:start position:0% +because no again no primary care +physician + + align:start position:0% +physician + + + align:start position:0% +physician +can know as i said barely knows how to + + align:start position:0% +can know as i said barely knows how to + + + align:start position:0% +can know as i said barely knows how to +almost none of them + + align:start position:0% +almost none of them + + + align:start position:0% +almost none of them +know fully all the literature in + + align:start position:0% +know fully all the literature in + + + align:start position:0% +know fully all the literature in +prostate specific antigen + + align:start position:0% +prostate specific antigen + + + align:start position:0% +prostate specific antigen +screening for prostate cancer and let + + align:start position:0% +screening for prostate cancer and let + + + align:start position:0% +screening for prostate cancer and let +alone for 30 000 tests so i think the it + + align:start position:0% +alone for 30 000 tests so i think the it + + + align:start position:0% +alone for 30 000 tests so i think the it +would have to be a distilled + + align:start position:0% +would have to be a distilled + + + align:start position:0% +would have to be a distilled +utility based sensitivity specificity + + align:start position:0% +utility based sensitivity specificity + + + align:start position:0% +utility based sensitivity specificity +based + + align:start position:0% +based + + + align:start position:0% +based +that's what i mean like you know they + + align:start position:0% +that's what i mean like you know they + + + align:start position:0% +that's what i mean like you know they +get they got a sheet back + + align:start position:0% + + + + align:start position:0% + +in that sense absolutely + + align:start position:0% +in that sense absolutely + + + align:start position:0% +in that sense absolutely +i think that's that is the only way + + align:start position:0% +i think that's that is the only way + + + align:start position:0% +i think that's that is the only way +uh you know endocrinologists have made a + + align:start position:0% +uh you know endocrinologists have made a + + + align:start position:0% +uh you know endocrinologists have made a +big career out of just interpreting uh + + align:start position:0% +big career out of just interpreting uh + + + align:start position:0% +big career out of just interpreting uh +three numbers uh tsh uh tbgi and t4 in + + align:start position:0% +three numbers uh tsh uh tbgi and t4 in + + + align:start position:0% +three numbers uh tsh uh tbgi and t4 in +the thyroid test because guess what most + + align:start position:0% +the thyroid test because guess what most + + + align:start position:0% +the thyroid test because guess what most +medical students can never figure out + + align:start position:0% +medical students can never figure out + + + align:start position:0% +medical students can never figure out +which way means hyperthyroids + + align:start position:0% +which way means hyperthyroids + + + align:start position:0% +which way means hyperthyroids +hypothyroidism or changes in the amount + + align:start position:0% +hypothyroidism or changes in the amount + + + align:start position:0% +hypothyroidism or changes in the amount +of binding uh protein they + + align:start position:0% + + + + align:start position:0% + +medical just to just the category of + + align:start position:0% +medical just to just the category of + + + align:start position:0% +medical just to just the category of +specialists once again well + + align:start position:0% +specialists once again well + + + align:start position:0% +specialists once again well +the lack of a specific disease + + align:start position:0% +the lack of a specific disease + + + align:start position:0% +the lack of a specific disease +no it's well i don't see i'm i'm claimed + + align:start position:0% +no it's well i don't see i'm i'm claimed + + + align:start position:0% +no it's well i don't see i'm i'm claimed +that the + + align:start position:0% +that the + + + align:start position:0% +that the +system + + align:start position:0% +system + + + align:start position:0% +system +um cannot + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +have a expert medical genomicist + + align:start position:0% +have a expert medical genomicist + + + align:start position:0% +have a expert medical genomicist +that since we are + + align:start position:0% +that since we are + + + align:start position:0% +that since we are +a lot of what we were talking about is + + align:start position:0% +a lot of what we were talking about is + + + align:start position:0% +a lot of what we were talking about is +primary care it's prevention this has to + + align:start position:0% +primary care it's prevention this has to + + + align:start position:0% +primary care it's prevention this has to +be in every primary care + + align:start position:0% +be in every primary care + + + align:start position:0% +be in every primary care +situation so it's either outsourced + + align:start position:0% +situation so it's either outsourced + + + align:start position:0% +situation so it's either outsourced +essentially to the internet uh to some + + align:start position:0% +essentially to the internet uh to some + + + align:start position:0% +essentially to the internet uh to some +other group of people + + align:start position:0% +other group of people + + + align:start position:0% +other group of people +have a low-cost parallel assistant + + align:start position:0% +have a low-cost parallel assistant + + + align:start position:0% +have a low-cost parallel assistant +whether it's a human + + align:start position:0% +whether it's a human + + + align:start position:0% +whether it's a human +or more likely a computer program and + + align:start position:0% +or more likely a computer program and + + + align:start position:0% +or more likely a computer program and +the third is just redoing education so + + align:start position:0% +the third is just redoing education so + + + align:start position:0% +the third is just redoing education so +um to + + align:start position:0% +um to + + + align:start position:0% +um to +to your scenario which i think is a good + + align:start position:0% +to your scenario which i think is a good + + + align:start position:0% +to your scenario which i think is a good +uh one of the good ones which is to have + + align:start position:0% +uh one of the good ones which is to have + + + align:start position:0% +uh one of the good ones which is to have +a very simplified set of + + align:start position:0% +a very simplified set of + + + align:start position:0% +a very simplified set of +recommendations come to the primary care + + align:start position:0% +recommendations come to the primary care + + + align:start position:0% +recommendations come to the primary care +physician it's a primary care physician + + align:start position:0% +physician it's a primary care physician + + + align:start position:0% +physician it's a primary care physician +still who just has to learn how to look + + align:start position:0% +still who just has to learn how to look + + + align:start position:0% +still who just has to learn how to look +intelligently at that report that set of + + align:start position:0% +intelligently at that report that set of + + + align:start position:0% +intelligently at that report that set of +recommendations + + align:start position:0% +recommendations + + + align:start position:0% +recommendations +i don't see them having to learn + + align:start position:0% +i don't see them having to learn + + + align:start position:0% +i don't see them having to learn +the third you know the 30 000 genes and + + align:start position:0% +the third you know the 30 000 genes and + + + align:start position:0% +the third you know the 30 000 genes and +all the epigenetic and genetic effects + + align:start position:0% +all the epigenetic and genetic effects + + + align:start position:0% +all the epigenetic and genetic effects +that does not seem reasonable + + align:start position:0% +that does not seem reasonable + + + align:start position:0% +that does not seem reasonable +but this is the fundamental problem that + + align:start position:0% +but this is the fundamental problem that + + + align:start position:0% +but this is the fundamental problem that +we have in in genomic medicine and + + align:start position:0% +we have in in genomic medicine and + + + align:start position:0% +we have in in genomic medicine and +that's this is going to be by far the + + align:start position:0% +that's this is going to be by far the + + + align:start position:0% +that's this is going to be by far the +rate limiting step + + align:start position:0% +rate limiting step + + + align:start position:0% +rate limiting step +for any penetration to to managing human + + align:start position:0% +for any penetration to to managing human + + + align:start position:0% +for any penetration to to managing human +disease than any any other aspect + + align:start position:0% +disease than any any other aspect + + + align:start position:0% +disease than any any other aspect +of um + + align:start position:0% +of um + + + align:start position:0% +of um +the genomic enterprise we're going to + + align:start position:0% +the genomic enterprise we're going to + + + align:start position:0% +the genomic enterprise we're going to +discover lots of interesting things + + align:start position:0% +discover lots of interesting things + + + align:start position:0% +discover lots of interesting things +we're not we're going to + + align:start position:0% +we're not we're going to + + + align:start position:0% +we're not we're going to +find good drugs we're going to make + + align:start position:0% +find good drugs we're going to make + + + align:start position:0% +find good drugs we're going to make +interesting diagnoses but translating it + + align:start position:0% +interesting diagnoses but translating it + + + align:start position:0% +interesting diagnoses but translating it +into cares would be + + align:start position:0% +into cares would be + + + align:start position:0% +into cares would be +uh the real challenge + + align:start position:0% +uh the real challenge + + + align:start position:0% +uh the real challenge +so how we're gonna pay for those roles + + align:start position:0% +so how we're gonna pay for those roles + + + align:start position:0% +so how we're gonna pay for those roles +extremely unclear right now you can't + + align:start position:0% +extremely unclear right now you can't + + + align:start position:0% +extremely unclear right now you can't +get a lot of genetic tests paid for + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +and finally because + + align:start position:0% +and finally because + + + align:start position:0% +and finally because +it's very expensive and became free + + align:start position:0% +it's very expensive and became free + + + align:start position:0% +it's very expensive and became free +everybody would use it i mean right now + + align:start position:0% +everybody would use it i mean right now + + + align:start position:0% +everybody would use it i mean right now +as i told you begin the first lecture + + align:start position:0% +as i told you begin the first lecture + + + align:start position:0% +as i told you begin the first lecture +in the high throughput lab it costs + + align:start position:0% +in the high throughput lab it costs + + + align:start position:0% +in the high throughput lab it costs +um 10 cents to do a genotype do you know + + align:start position:0% +um 10 cents to do a genotype do you know + + + align:start position:0% +um 10 cents to do a genotype do you know +how much it costs to actually how much + + align:start position:0% +how much it costs to actually how much + + + align:start position:0% +how much it costs to actually how much +the the system is built for for that + + align:start position:0% +the the system is built for for that + + + align:start position:0% +the the system is built for for that +test + + align:start position:0% +test + + + align:start position:0% +test +so that i was talking about the first + + align:start position:0% +so that i was talking about the first + + + align:start position:0% +so that i was talking about the first +like 10 cents in order to tell you wow + + align:start position:0% +like 10 cents in order to tell you wow + + + align:start position:0% +like 10 cents in order to tell you wow +the genomic future is now we can do very + + align:start position:0% +the genomic future is now we can do very + + + align:start position:0% +the genomic future is now we can do very +cheap screening but how much are we uh + + align:start position:0% +cheap screening but how much are we uh + + + align:start position:0% +cheap screening but how much are we uh +is our insurance system being billed for + + align:start position:0% +is our insurance system being billed for + + + align:start position:0% +is our insurance system being billed for +for these + + align:start position:0% +for these + + + align:start position:0% +for these +tests for that single genotype + + align:start position:0% + + + + align:start position:0% + +over a thousand dollars + + align:start position:0% + + + + align:start position:0% + +but if there's a symptom i mean there's + + align:start position:0% +but if there's a symptom i mean there's + + + align:start position:0% +but if there's a symptom i mean there's +no i mean that's not the real cost + + align:start position:0% +no i mean that's not the real cost + + + align:start position:0% +no i mean that's not the real cost +that's that's a huge profit margin right + + align:start position:0% +that's that's a huge profit margin right + + + align:start position:0% +that's that's a huge profit margin right +there there's a similar debate going on + + align:start position:0% +there there's a similar debate going on + + + align:start position:0% +there there's a similar debate going on +with it's like full body + + align:start position:0% +with it's like full body + + + align:start position:0% +with it's like full body +mri scans + + align:start position:0% +mri scans + + + align:start position:0% +mri scans +sure + + align:start position:0% +sure + + + align:start position:0% +sure +and so i mean + + align:start position:0% +and so i mean + + + align:start position:0% +and so i mean +where are the voices in the field for + + align:start position:0% +where are the voices in the field for + + + align:start position:0% +where are the voices in the field for +like this and for those saying + + align:start position:0% +like this and for those saying + + + align:start position:0% +like this and for those saying +you know preventatively if you do you + + align:start position:0% +you know preventatively if you do you + + + align:start position:0% +you know preventatively if you do you +know a whole battery of non-invasive + + align:start position:0% +know a whole battery of non-invasive + + + align:start position:0% +know a whole battery of non-invasive +you know one-day tests and yet submit a + + align:start position:0% +you know one-day tests and yet submit a + + + align:start position:0% +you know one-day tests and yet submit a +sample you know that you can do your + + align:start position:0% +sample you know that you can do your + + + align:start position:0% +sample you know that you can do your +genomic testing you sit in the mri you + + align:start position:0% +genomic testing you sit in the mri you + + + align:start position:0% +genomic testing you sit in the mri you +do other stuff and then hey we found + + align:start position:0% +do other stuff and then hey we found + + + align:start position:0% +do other stuff and then hey we found +this particular season we just saved 67 + + align:start position:0% +this particular season we just saved 67 + + + align:start position:0% +this particular season we just saved 67 +maybe 100 000 + + align:start position:0% +maybe 100 000 + + + align:start position:0% +maybe 100 000 +well that's not like first of all that's + + align:start position:0% +well that's not like first of all that's + + + align:start position:0% +well that's not like first of all that's +not where the system sees it the system + + align:start position:0% +not where the system sees it the system + + + align:start position:0% +not where the system sees it the system +sees that you spent um + + align:start position:0% +sees that you spent um + + + align:start position:0% +sees that you spent um +four thousand bucks + + align:start position:0% +four thousand bucks + + + align:start position:0% +four thousand bucks +and + + align:start position:0% +and + + + align:start position:0% +and +my insurance my my insurance company is + + align:start position:0% +my insurance my my insurance company is + + + align:start position:0% +my insurance my my insurance company is +gonna reward me for what i wanted to do + + align:start position:0% +gonna reward me for what i wanted to do + + + align:start position:0% +gonna reward me for what i wanted to do +the next two three years if you've you + + align:start position:0% +the next two three years if you've you + + + align:start position:0% +the next two three years if you've you +know dropped debt of cancer 10 years + + align:start position:0% +know dropped debt of cancer 10 years + + + align:start position:0% +know dropped debt of cancer 10 years +from now the that's going to be the + + align:start position:0% +from now the that's going to be the + + + align:start position:0% +from now the that's going to be the +balance on the insurance company 10 + + align:start position:0% +balance on the insurance company 10 + + + align:start position:0% +balance on the insurance company 10 +years from now there's not a lot of + + align:start position:0% +years from now there's not a lot of + + + align:start position:0% +years from now there's not a lot of +payback to me but more importantly + + align:start position:0% +payback to me but more importantly + + + align:start position:0% +payback to me but more importantly +speaking as a clinician i think these + + align:start position:0% +speaking as a clinician i think these + + + align:start position:0% +speaking as a clinician i think these +total body mris are terrible because + + align:start position:0% +total body mris are terrible because + + + align:start position:0% +total body mris are terrible because +you're finding a lot of + + align:start position:0% +you're finding a lot of + + + align:start position:0% +you're finding a lot of +incidental + + align:start position:0% +incidental + + + align:start position:0% +incidental +findings in fact the medical + + align:start position:0% +findings in fact the medical + + + align:start position:0% +findings in fact the medical +establishment is against those i think + + align:start position:0% +establishment is against those i think + + + align:start position:0% +establishment is against those i think +for good reason because again it's + + align:start position:0% +for good reason because again it's + + + align:start position:0% +for good reason because again it's +um + + align:start position:0% +um + + + align:start position:0% +um +the probabilities that we have around + + align:start position:0% +the probabilities that we have around + + + align:start position:0% +the probabilities that we have around +the meaning of + + align:start position:0% +the meaning of + + + align:start position:0% +the meaning of +um bumps on the mri is around people + + align:start position:0% +um bumps on the mri is around people + + + align:start position:0% +um bumps on the mri is around people +presenting with certain symptoms because + + align:start position:0% +presenting with certain symptoms because + + + align:start position:0% +presenting with certain symptoms because +these studies are around that and if you + + align:start position:0% +these studies are around that and if you + + + align:start position:0% +these studies are around that and if you +just have joe blow off the street who + + align:start position:0% +just have joe blow off the street who + + + align:start position:0% +just have joe blow off the street who +just has a birthday present a full body + + align:start position:0% +just has a birthday present a full body + + + align:start position:0% +just has a birthday present a full body +mri scan + + align:start position:0% +mri scan + + + align:start position:0% +mri scan +uh which by the way didn't that have you + + align:start position:0% +uh which by the way didn't that have you + + + align:start position:0% +uh which by the way didn't that have you +heard the advertisements for it no it's + + align:start position:0% +heard the advertisements for it no it's + + + align:start position:0% +heard the advertisements for it no it's +it's your yeah it's your fourth year + + align:start position:0% +it's your yeah it's your fourth year + + + align:start position:0% +it's your yeah it's your fourth year +40th birthday uh don't you want to do + + align:start position:0% +40th birthday uh don't you want to do + + + align:start position:0% +40th birthday uh don't you want to do +this or your dad's birthday don't you + + align:start position:0% +this or your dad's birthday don't you + + + align:start position:0% +this or your dad's birthday don't you +and they talk about the uh some you know + + align:start position:0% +and they talk about the uh some you know + + + align:start position:0% +and they talk about the uh some you know +the advertisement is uh joe blow the + + align:start position:0% +the advertisement is uh joe blow the + + + align:start position:0% +the advertisement is uh joe blow the +patient reports oh so is reassured on my + + align:start position:0% +patient reports oh so is reassured on my + + + align:start position:0% +patient reports oh so is reassured on my +40th birthday to see if nothing's wrong + + align:start position:0% +40th birthday to see if nothing's wrong + + + align:start position:0% +40th birthday to see if nothing's wrong +with me what they don't report on is the + + align:start position:0% +with me what they don't report on is the + + + align:start position:0% +with me what they don't report on is the +old people who got bumps in their head + + align:start position:0% +old people who got bumps in their head + + + align:start position:0% +old people who got bumps in their head +and then had to go for creating + + align:start position:0% +and then had to go for creating + + + align:start position:0% +and then had to go for creating +craniotomy god knows what to investigate + + align:start position:0% +craniotomy god knows what to investigate + + + align:start position:0% +craniotomy god knows what to investigate +uh these things + + align:start position:0% +uh these things + + + align:start position:0% +uh these things +so i promise you that we want that we're + + align:start position:0% +so i promise you that we want that we're + + + align:start position:0% +so i promise you that we want that we're +gonna stick to the pragmatics so this is + + align:start position:0% +gonna stick to the pragmatics so this is + + + align:start position:0% +gonna stick to the pragmatics so this is +why it is not penetration today but + + align:start position:0% +why it is not penetration today but + + + align:start position:0% +why it is not penetration today but +today + + align:start position:0% +today + + + align:start position:0% +today +how + + align:start position:0% +how + + + align:start position:0% +how +how do you order a test + + align:start position:0% +how do you order a test + + + align:start position:0% +how do you order a test +um a genetic test for a clinical problem + + align:start position:0% +um a genetic test for a clinical problem + + + align:start position:0% +um a genetic test for a clinical problem +what do you do + + align:start position:0% + + + + align:start position:0% + +how do you order it well yeah what do + + align:start position:0% +how do you order it well yeah what do + + + align:start position:0% +how do you order it well yeah what do +you do um + + align:start position:0% +you do um + + + align:start position:0% +you do um +[Music] + + align:start position:0% + + + + align:start position:0% + +that's very very important + + align:start position:0% +that's very very important + + + align:start position:0% +that's very very important +gene clinics and genetest + + align:start position:0% +gene clinics and genetest + + + align:start position:0% +gene clinics and genetest +it's one thing you better + + align:start position:0% +it's one thing you better + + + align:start position:0% +it's one thing you better +stick to after this class because that + + align:start position:0% +stick to after this class because that + + + align:start position:0% +stick to after this class because that +there are thousands of clinics + + align:start position:0% +there are thousands of clinics + + + align:start position:0% +there are thousands of clinics +and labs across the united states that + + align:start position:0% +and labs across the united states that + + + align:start position:0% +and labs across the united states that +have one or two tests there's no single + + align:start position:0% +have one or two tests there's no single + + + align:start position:0% +have one or two tests there's no single +giant aggregator of genetic tests and + + align:start position:0% +giant aggregator of genetic tests and + + + align:start position:0% +giant aggregator of genetic tests and +this is one website maintained by my + + align:start position:0% +this is one website maintained by my + + + align:start position:0% +this is one website maintained by my +colleague peter tarzi hornock and the + + align:start position:0% +colleague peter tarzi hornock and the + + + align:start position:0% +colleague peter tarzi hornock and the +university of washington + + align:start position:0% +university of washington + + + align:start position:0% +university of washington +uh that has all that so + + align:start position:0% +uh that has all that so + + + align:start position:0% +uh that has all that so +that's exactly right + + align:start position:0% +that's exactly right + + + align:start position:0% +that's exactly right +i mean just a question + + align:start position:0% +i mean just a question + + + align:start position:0% +i mean just a question +do you think that's going to eventually + + align:start position:0% +do you think that's going to eventually + + + align:start position:0% +do you think that's going to eventually +roll under the quests and uh + + align:start position:0% +roll under the quests and uh + + + align:start position:0% +roll under the quests and uh +100 so let me let me that's an excellent + + align:start position:0% +100 so let me let me that's an excellent + + + align:start position:0% +100 so let me let me that's an excellent +question and so let me um + + align:start position:0% +question and so let me um + + + align:start position:0% +question and so let me um +um + + align:start position:0% +um + + + align:start position:0% +um +let me okay let me just get that + + align:start position:0% +let me okay let me just get that + + + align:start position:0% +let me okay let me just get that +question in uh two minutes + + align:start position:0% +question in uh two minutes + + + align:start position:0% +question in uh two minutes +so this is uh for the this i'm sorry + + align:start position:0% +so this is uh for the this i'm sorry + + + align:start position:0% +so this is uh for the this i'm sorry +it's an old slide it's a year old slide + + align:start position:0% +it's an old slide it's a year old slide + + + align:start position:0% +it's an old slide it's a year old slide +and + + align:start position:0% +and + + + align:start position:0% +and +they had on gene clinic student tests + + align:start position:0% +they had on gene clinic student tests + + + align:start position:0% +they had on gene clinic student tests +189 gene reviews which are very nice + + align:start position:0% +189 gene reviews which are very nice + + + align:start position:0% +189 gene reviews which are very nice +monographs around the specific disease + + align:start position:0% +monographs around the specific disease + + + align:start position:0% +monographs around the specific disease +involving a thousand different clinics + + align:start position:0% +involving a thousand different clinics + + + align:start position:0% +involving a thousand different clinics +and 500 laboratories covering 948 + + align:start position:0% +and 500 laboratories covering 948 + + + align:start position:0% +and 500 laboratories covering 948 +diseases + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +the short answer is + + align:start position:0% +the short answer is + + + align:start position:0% +the short answer is +yes + + align:start position:0% +yes + + + align:start position:0% +yes +these are going to be rolled up + + align:start position:0% +these are going to be rolled up + + + align:start position:0% +these are going to be rolled up +into + + align:start position:0% +into + + + align:start position:0% +into +um the quests and the various laboratory + + align:start position:0% +um the quests and the various laboratory + + + align:start position:0% +um the quests and the various laboratory +corporations the real question is + + align:start position:0% + + + + align:start position:0% + +ultimately we know what's going to look + + align:start position:0% +ultimately we know what's going to look + + + align:start position:0% +ultimately we know what's going to look +like it's going to be a highly + + align:start position:0% +like it's going to be a highly + + + align:start position:0% +like it's going to be a highly +roboticized + + align:start position:0% +roboticized + + + align:start position:0% +roboticized +um sequencing genotyping operation these + + align:start position:0% +um sequencing genotyping operation these + + + align:start position:0% +um sequencing genotyping operation these +in these labs but in in the interim it + + align:start position:0% +in these labs but in in the interim it + + + align:start position:0% +in these labs but in in the interim it +may still be that it's rolled up but the + + align:start position:0% +may still be that it's rolled up but the + + + align:start position:0% +may still be that it's rolled up but the +actual + + align:start position:0% +actual + + + align:start position:0% +actual +sequencing and procedures might still be + + align:start position:0% +sequencing and procedures might still be + + + align:start position:0% +sequencing and procedures might still be +at these various places + + align:start position:0% +at these various places + + + align:start position:0% +at these various places +and these companies might just uh + + align:start position:0% +and these companies might just uh + + + align:start position:0% +and these companies might just uh +contract to these various sources right + + align:start position:0% +contract to these various sources right + + + align:start position:0% +contract to these various sources right +now for instance if you want to do + + align:start position:0% +now for instance if you want to do + + + align:start position:0% +now for instance if you want to do +duchenne's testing your sample goes to a + + align:start position:0% +duchenne's testing your sample goes to a + + + align:start position:0% +duchenne's testing your sample goes to a +place in utah now why is that but why + + align:start position:0% +place in utah now why is that but why + + + align:start position:0% +place in utah now why is that but why +not just roll into one place because + + align:start position:0% +not just roll into one place because + + + align:start position:0% +not just roll into one place because +the guys at the the who's who is + + align:start position:0% +the guys at the the who's who is + + + align:start position:0% +the guys at the the who's who is +resequencing the duchenne's gene for + + align:start position:0% +resequencing the duchenne's gene for + + + align:start position:0% +resequencing the duchenne's gene for +additional muscle dystrophy know + + align:start position:0% +additional muscle dystrophy know + + + align:start position:0% +additional muscle dystrophy know +which primers aka which sequence work + + align:start position:0% +which primers aka which sequence work + + + align:start position:0% +which primers aka which sequence work +the best to amplify different segments + + align:start position:0% +the best to amplify different segments + + + align:start position:0% +the best to amplify different segments +of the gene to get reliable results and + + align:start position:0% +of the gene to get reliable results and + + + align:start position:0% +of the gene to get reliable results and +that know how ultimately can be + + align:start position:0% +that know how ultimately can be + + + align:start position:0% +that know how ultimately can be +definitely rolled up but in the interim + + align:start position:0% +definitely rolled up but in the interim + + + align:start position:0% +definitely rolled up but in the interim +on the five to you know the five-year + + align:start position:0% +on the five to you know the five-year + + + align:start position:0% +on the five to you know the five-year +time scale may or may not be just left + + align:start position:0% +time scale may or may not be just left + + + align:start position:0% +time scale may or may not be just left +locally + + align:start position:0% +locally + + + align:start position:0% +locally +and so what the labs will what these + + align:start position:0% +and so what the labs will what these + + + align:start position:0% +and so what the labs will what these +requests will be are more aggravators + + align:start position:0% +requests will be are more aggravators + + + align:start position:0% +requests will be are more aggravators +and front-ends + + align:start position:0% +and front-ends + + + align:start position:0% +and front-ends +conduits + + align:start position:0% +conduits + + + align:start position:0% +conduits +or channels as the marketers like to say + + align:start position:0% +or channels as the marketers like to say + + + align:start position:0% +or channels as the marketers like to say +to these myriad labs ultimately i think + + align:start position:0% +to these myriad labs ultimately i think + + + align:start position:0% +to these myriad labs ultimately i think +everybody believes it'll be in one + + align:start position:0% +everybody believes it'll be in one + + + align:start position:0% +everybody believes it'll be in one +highly robotic sized facility in each + + align:start position:0% +highly robotic sized facility in each + + + align:start position:0% +highly robotic sized facility in each +one of these + + align:start position:0% +one of these + + + align:start position:0% +one of these +facilities because after all a gene is a + + align:start position:0% +facilities because after all a gene is a + + + align:start position:0% +facilities because after all a gene is a +gene as a gene + + align:start position:0% +gene as a gene + + + align:start position:0% +gene as a gene +but because of things like + + align:start position:0% + + + + align:start position:0% + +knowledge of what primers work + + align:start position:0% +knowledge of what primers work + + + align:start position:0% +knowledge of what primers work +knowledge of which mutations are common + + align:start position:0% +knowledge of which mutations are common + + + align:start position:0% +knowledge of which mutations are common +and what they mean + + align:start position:0% +and what they mean + + + align:start position:0% +and what they mean +all that knowledge management is still + + align:start position:0% +all that knowledge management is still + + + align:start position:0% +all that knowledge management is still +distributed and rolling it up + + align:start position:0% +distributed and rolling it up + + + align:start position:0% +distributed and rolling it up +is going to be i think uh + + align:start position:0% +is going to be i think uh + + + align:start position:0% +is going to be i think uh +the uh break on that uh full roll up + + align:start position:0% +the uh break on that uh full roll up + + + align:start position:0% +the uh break on that uh full roll up +so it for those of you of you who don't + + align:start position:0% +so it for those of you of you who don't + + + align:start position:0% +so it for those of you of you who don't +know the site so if you want to test for + + align:start position:0% +know the site so if you want to test for + + + align:start position:0% +know the site so if you want to test for +a particular problem you you can look at + + align:start position:0% +a particular problem you you can look at + + + align:start position:0% +a particular problem you you can look at +uh this thing and you say i'm gonna look + + align:start position:0% +uh this thing and you say i'm gonna look + + + align:start position:0% +uh this thing and you say i'm gonna look +at obesity and i'll tell you which + + align:start position:0% +at obesity and i'll tell you which + + + align:start position:0% +at obesity and i'll tell you which +laboratory will do + + align:start position:0% +laboratory will do + + + align:start position:0% +laboratory will do +which um + + align:start position:0% +which um + + + align:start position:0% +which um +testing for in fact + + align:start position:0% +testing for in fact + + + align:start position:0% +testing for in fact +probably the only obesity-related gene + + align:start position:0% +probably the only obesity-related gene + + + align:start position:0% +probably the only obesity-related gene +worth testing for right now is mc4r it's + + align:start position:0% +worth testing for right now is mc4r it's + + + align:start position:0% +worth testing for right now is mc4r it's +the most + + align:start position:0% +the most + + + align:start position:0% +the most +common + + align:start position:0% +common + + + align:start position:0% +common +genetically associated cause of + + align:start position:0% +genetically associated cause of + + + align:start position:0% +genetically associated cause of +um obesity mc4r is melanocorticotropin + + align:start position:0% +um obesity mc4r is melanocorticotropin + + + align:start position:0% +um obesity mc4r is melanocorticotropin +uh receptor + + align:start position:0% +uh receptor + + + align:start position:0% +uh receptor +the fourth uh type + + align:start position:0% +the fourth uh type + + + align:start position:0% +the fourth uh type +and + + align:start position:0% +and + + + align:start position:0% +and +um some high percentage on the order of + + align:start position:0% +um some high percentage on the order of + + + align:start position:0% +um some high percentage on the order of +two percent of individuals uh with uh + + align:start position:0% +two percent of individuals uh with uh + + + align:start position:0% +two percent of individuals uh with uh +according to some studies with uh + + align:start position:0% +according to some studies with uh + + + align:start position:0% +according to some studies with uh +morbid obesity have uh mutations here + + align:start position:0% +morbid obesity have uh mutations here + + + align:start position:0% +morbid obesity have uh mutations here +unfortunately for those the rest of us + + align:start position:0% +unfortunately for those the rest of us + + + align:start position:0% +unfortunately for those the rest of us +um like me + + align:start position:0% +um like me + + + align:start position:0% +um like me +um we're just fat because we eat wrong + + align:start position:0% +um we're just fat because we eat wrong + + + align:start position:0% +um we're just fat because we eat wrong +so we're talking about + + align:start position:0% +so we're talking about + + + align:start position:0% +so we're talking about +go ahead + + align:start position:0% +go ahead + + + align:start position:0% +go ahead +yep + + align:start position:0% +yep + + + align:start position:0% +yep +but is this indexing that gene clanks + + align:start position:0% +but is this indexing that gene clanks + + + align:start position:0% +but is this indexing that gene clanks +and gene tesla are generally sufficient + + align:start position:0% +and gene tesla are generally sufficient + + + align:start position:0% +and gene tesla are generally sufficient +so if you look at congenital adrenal + + align:start position:0% +so if you look at congenital adrenal + + + align:start position:0% +so if you look at congenital adrenal +hyperplasia or adrenal adrenal + + align:start position:0% +hyperplasia or adrenal adrenal + + + align:start position:0% +hyperplasia or adrenal adrenal +hyperplasia which is a disease + + align:start position:0% + + + + align:start position:0% + +of children and adulthood that's + + align:start position:0% +of children and adulthood that's + + + align:start position:0% +of children and adulthood that's +responsible for ambiguous ambiguous + + align:start position:0% +responsible for ambiguous ambiguous + + + align:start position:0% +responsible for ambiguous ambiguous +genitalia and infants + + align:start position:0% +genitalia and infants + + + align:start position:0% +genitalia and infants +hirsutism and infertility in females + + align:start position:0% +hirsutism and infertility in females + + + align:start position:0% +hirsutism and infertility in females +and + + align:start position:0% +and + + + align:start position:0% +and +precursors puberty for + + align:start position:0% +precursors puberty for + + + align:start position:0% +precursors puberty for +males and females + + align:start position:0% +males and females + + + align:start position:0% +males and females +so if you look for + + align:start position:0% +so if you look for + + + align:start position:0% +so if you look for +adrenal hyperplasia + + align:start position:0% +adrenal hyperplasia + + + align:start position:0% +adrenal hyperplasia +you see the following you get 21 + + align:start position:0% +you see the following you get 21 + + + align:start position:0% +you see the following you get 21 +hydroxylase deficiency + + align:start position:0% +hydroxylase deficiency + + + align:start position:0% +hydroxylase deficiency +what's the right thing to actually order + + align:start position:0% +what's the right thing to actually order + + + align:start position:0% +what's the right thing to actually order +well if you actually knew something + + align:start position:0% +well if you actually knew something + + + align:start position:0% +well if you actually knew something +about the pathway the the um + + align:start position:0% +about the pathway the the um + + + align:start position:0% +about the pathway the the um +steroidogenesis pathway you know that it + + align:start position:0% +steroidogenesis pathway you know that it + + + align:start position:0% +steroidogenesis pathway you know that it +starts from cholesterol the cholesterol + + align:start position:0% +starts from cholesterol the cholesterol + + + align:start position:0% +starts from cholesterol the cholesterol +that we all + + align:start position:0% +that we all + + + align:start position:0% +that we all +claim to hate + + align:start position:0% +claim to hate + + + align:start position:0% +claim to hate +actually is the backbone from all the + + align:start position:0% +actually is the backbone from all the + + + align:start position:0% +actually is the backbone from all the +steroid hormone molecules cholesterol + + align:start position:0% +steroid hormone molecules cholesterol + + + align:start position:0% +steroid hormone molecules cholesterol +will make all the um + + align:start position:0% +will make all the um + + + align:start position:0% +will make all the um +salt retaining hormones like aldosterone + + align:start position:0% +salt retaining hormones like aldosterone + + + align:start position:0% +salt retaining hormones like aldosterone +the glucose stimulating hormones like + + align:start position:0% +the glucose stimulating hormones like + + + align:start position:0% +the glucose stimulating hormones like +cortisol + + align:start position:0% +cortisol + + + align:start position:0% +cortisol +and the sex hormones like testosterone + + align:start position:0% +and the sex hormones like testosterone + + + align:start position:0% +and the sex hormones like testosterone +and estradiol + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +an appreciation + + align:start position:0% +an appreciation + + + align:start position:0% +an appreciation +of + + align:start position:0% +of + + + align:start position:0% +of +what the pathways are is going to allow + + align:start position:0% +what the pathways are is going to allow + + + align:start position:0% +what the pathways are is going to allow +you to actually do focus testing + + align:start position:0% +you to actually do focus testing + + + align:start position:0% +you to actually do focus testing +so that for instance 21 hydroxyl + + align:start position:0% +so that for instance 21 hydroxyl + + + align:start position:0% +so that for instance 21 hydroxyl +deficiency is in fact the most common + + align:start position:0% +deficiency is in fact the most common + + + align:start position:0% +deficiency is in fact the most common +but there are other deficiencies that + + align:start position:0% +but there are other deficiencies that + + + align:start position:0% +but there are other deficiencies that +happen with some regularity like five + + align:start position:0% +happen with some regularity like five + + + align:start position:0% +happen with some regularity like five +percent of congenital adrenal + + align:start position:0% +percent of congenital adrenal + + + align:start position:0% +percent of congenital adrenal +hyperplasia is 11 hydroxylase deficiency + + align:start position:0% +hyperplasia is 11 hydroxylase deficiency + + + align:start position:0% +hyperplasia is 11 hydroxylase deficiency +and not 21 hydroxylase deficiency and + + align:start position:0% +and not 21 hydroxylase deficiency and + + + align:start position:0% +and not 21 hydroxylase deficiency and +the bars here to show um + + align:start position:0% +the bars here to show um + + + align:start position:0% +the bars here to show um +the + + align:start position:0% +the + + + align:start position:0% +the +the block in the pathway that would be + + align:start position:0% +the block in the pathway that would be + + + align:start position:0% +the block in the pathway that would be +caused by the deficiency of that gene + + align:start position:0% +caused by the deficiency of that gene + + + align:start position:0% +caused by the deficiency of that gene +and so the point is you still need a lot + + align:start position:0% +and so the point is you still need a lot + + + align:start position:0% +and so the point is you still need a lot +of knowledge + + align:start position:0% +of knowledge + + + align:start position:0% +of knowledge +around that specific disease in the + + align:start position:0% +around that specific disease in the + + + align:start position:0% +around that specific disease in the +pathways rather than just going up to a + + align:start position:0% +pathways rather than just going up to a + + + align:start position:0% +pathways rather than just going up to a +database that says + + align:start position:0% +database that says + + + align:start position:0% +database that says +obesity + + align:start position:0% +obesity + + + align:start position:0% +obesity +this gene you still have to have some + + align:start position:0% +this gene you still have to have some + + + align:start position:0% +this gene you still have to have some +knowledge about what you're looking for + + align:start position:0% +knowledge about what you're looking for + + + align:start position:0% +knowledge about what you're looking for +so what material do you want to test + + align:start position:0% +so what material do you want to test + + + align:start position:0% +so what material do you want to test +let's take four diseases cystic fibrosis + + align:start position:0% +let's take four diseases cystic fibrosis + + + align:start position:0% +let's take four diseases cystic fibrosis +a disease + + align:start position:0% +a disease + + + align:start position:0% +a disease +uh where you get plugging on mucosal + + align:start position:0% +uh where you get plugging on mucosal + + + align:start position:0% +uh where you get plugging on mucosal +ducts + + align:start position:0% +ducts + + + align:start position:0% +ducts +and so it's a chloride transporter + + align:start position:0% +and so it's a chloride transporter + + + align:start position:0% +and so it's a chloride transporter +problem and people die young + + align:start position:0% +problem and people die young + + + align:start position:0% +problem and people die young +you call it macune outbreak disease a + + align:start position:0% +you call it macune outbreak disease a + + + align:start position:0% +you call it macune outbreak disease a +disease of uh the uh the g uh + + align:start position:0% +disease of uh the uh the g uh + + + align:start position:0% +disease of uh the uh the g uh +the g + + align:start position:0% +the g + + + align:start position:0% +the g +uh complex where um essentially you have + + align:start position:0% +uh complex where um essentially you have + + + align:start position:0% +uh complex where um essentially you have +an activating mutation in one of the + + align:start position:0% +an activating mutation in one of the + + + align:start position:0% +an activating mutation in one of the +subunits so that you have all the + + align:start position:0% +subunits so that you have all the + + + align:start position:0% +subunits so that you have all the +g-coupled uh processes are + + align:start position:0% +g-coupled uh processes are + + + align:start position:0% +g-coupled uh processes are +hyperactive so that you have kids with + + align:start position:0% +hyperactive so that you have kids with + + + align:start position:0% +hyperactive so that you have kids with +precocious puberty cortical adenomas of + + align:start position:0% +precocious puberty cortical adenomas of + + + align:start position:0% +precocious puberty cortical adenomas of +the adrenal and uh precursors puberty + + align:start position:0% + + + + align:start position:0% + +well mccune albert syndrome the the + + align:start position:0% +well mccune albert syndrome the the + + + align:start position:0% +well mccune albert syndrome the the +classical description is + + align:start position:0% +classical description is + + + align:start position:0% +classical description is +cafe au lait spots + + align:start position:0% + + + + align:start position:0% + +cafe les spots which are these basically + + align:start position:0% +cafe les spots which are these basically + + + align:start position:0% +cafe les spots which are these basically +looks like someone spilled coffee on + + align:start position:0% +looks like someone spilled coffee on + + + align:start position:0% +looks like someone spilled coffee on +your on your skin + + align:start position:0% + + + + align:start position:0% + +fibrous dysplasia of the bones so your + + align:start position:0% +fibrous dysplasia of the bones so your + + + align:start position:0% +fibrous dysplasia of the bones so your +bones are screwed around because they + + align:start position:0% +bones are screwed around because they + + + align:start position:0% +bones are screwed around because they +have these + + align:start position:0% +have these + + + align:start position:0% +have these +sort of + + align:start position:0% +sort of + + + align:start position:0% +sort of +ropey things going through them + + align:start position:0% +ropey things going through them + + + align:start position:0% +ropey things going through them +and precocious puberty + + align:start position:0% + + + + align:start position:0% + +it's + + align:start position:0% +it's + + + align:start position:0% +it's +distantly + + align:start position:0% +distantly + + + align:start position:0% +distantly +and but as we learn more about it + + align:start position:0% +and but as we learn more about it + + + align:start position:0% +and but as we learn more about it +multiple systems like thyroid + + align:start position:0% +multiple systems like thyroid + + + align:start position:0% +multiple systems like thyroid +and growth hormone can also be + + align:start position:0% +and growth hormone can also be + + + align:start position:0% +and growth hormone can also be +hyperstimulated so basically + + align:start position:0% +hyperstimulated so basically + + + align:start position:0% +hyperstimulated so basically +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +mosaic state where multiple or these + + align:start position:0% +mosaic state where multiple or these + + + align:start position:0% +mosaic state where multiple or these +mutations can actually be spread + + align:start position:0% +mutations can actually be spread + + + align:start position:0% +mutations can actually be spread +incompletely throughout the body and so + + align:start position:0% +incompletely throughout the body and so + + + align:start position:0% +incompletely throughout the body and so +for instance the melanocytes + + align:start position:0% +for instance the melanocytes + + + align:start position:0% +for instance the melanocytes +are stimulating just patches and if + + align:start position:0% +are stimulating just patches and if + + + align:start position:0% +are stimulating just patches and if +you're unlucky enough to have adrenal + + align:start position:0% +you're unlucky enough to have adrenal + + + align:start position:0% +you're unlucky enough to have adrenal +involved then you're getting adrenal + + align:start position:0% +involved then you're getting adrenal + + + align:start position:0% +involved then you're getting adrenal +adenoma + + align:start position:0% + + + + align:start position:0% + +please so + + align:start position:0% +please so + + + align:start position:0% +please so +uh can i get a scenario + + align:start position:0% +uh can i get a scenario + + + align:start position:0% +uh can i get a scenario +so a patient comes to you with mccune + + align:start position:0% +so a patient comes to you with mccune + + + align:start position:0% +so a patient comes to you with mccune +albeit syndrome and you suspect it + + align:start position:0% +albeit syndrome and you suspect it + + + align:start position:0% +albeit syndrome and you suspect it +because zach told me that they have + + align:start position:0% +because zach told me that they have + + + align:start position:0% +because zach told me that they have +these catholics but boy this person has + + align:start position:0% +these catholics but boy this person has + + + align:start position:0% +these catholics but boy this person has +two big ones uh and this person is + + align:start position:0% +two big ones uh and this person is + + + align:start position:0% +two big ones uh and this person is +having precocious puberty and is + + align:start position:0% +having precocious puberty and is + + + align:start position:0% +having precocious puberty and is +complaining bone pain what do i send to + + align:start position:0% +complaining bone pain what do i send to + + + align:start position:0% +complaining bone pain what do i send to +test + + align:start position:0% + + + + align:start position:0% + +that's the question + + align:start position:0% +that's the question + + + align:start position:0% +that's the question +so but whereas with the first one cystic + + align:start position:0% + + + + align:start position:0% + +you suspected they did uh you did a + + align:start position:0% +you suspected they did uh you did a + + + align:start position:0% +you suspected they did uh you did a +sweat test which has a certain + + align:start position:0% +sweat test which has a certain + + + align:start position:0% +sweat test which has a certain +uh specific specificity + + align:start position:0% +uh specific specificity + + + align:start position:0% +uh specific specificity +um + + align:start position:0% +um + + + align:start position:0% +um +specificity and uh uh sensitivity or + + align:start position:0% +specificity and uh uh sensitivity or + + + align:start position:0% +specificity and uh uh sensitivity or +let's make or maybe it's parent who + + align:start position:0% +let's make or maybe it's parent who + + + align:start position:0% +let's make or maybe it's parent who +already had a kid who died from sleep + + align:start position:0% +already had a kid who died from sleep + + + align:start position:0% +already had a kid who died from sleep +fibrosis + + align:start position:0% +fibrosis + + + align:start position:0% +fibrosis +and they just have a newborn what are + + align:start position:0% +and they just have a newborn what are + + + align:start position:0% +and they just have a newborn what are +you gonna what are you gonna test no you + + align:start position:0% +you gonna what are you gonna test no you + + + align:start position:0% +you gonna what are you gonna test no you +don't know the end thing yet + + align:start position:0% + + + + align:start position:0% + +so let's let's do one at a time cystic + + align:start position:0% +so let's let's do one at a time cystic + + + align:start position:0% +so let's let's do one at a time cystic +fibrosis + + align:start position:0% +fibrosis + + + align:start position:0% +fibrosis +a testing gene but i'm i'm a stupid + + align:start position:0% +a testing gene but i'm i'm a stupid + + + align:start position:0% +a testing gene but i'm i'm a stupid +doctor indeed i am + + align:start position:0% +doctor indeed i am + + + align:start position:0% +doctor indeed i am +what does it mean to test gene what + + align:start position:0% +what does it mean to test gene what + + + align:start position:0% +what does it mean to test gene what +thing do i stick into a tube + + align:start position:0% + + + + align:start position:0% + +no + + align:start position:0% +no + + + align:start position:0% +no +neutrino albright + + align:start position:0% +neutrino albright + + + align:start position:0% +neutrino albright +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +what if you you get a piece of you know + + align:start position:0% +what if you you get a piece of you know + + + align:start position:0% +what if you you get a piece of you know +uh you know a bit of maybe the cells + + align:start position:0% +uh you know a bit of maybe the cells + + + align:start position:0% +uh you know a bit of maybe the cells +here are not involved maybe it's not + + align:start position:0% +here are not involved maybe it's not + + + align:start position:0% +here are not involved maybe it's not +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +maybe you get a skin biopsy of of the + + align:start position:0% +maybe you get a skin biopsy of of the + + + align:start position:0% +maybe you get a skin biopsy of of the +caffeine spot + + align:start position:0% +caffeine spot + + + align:start position:0% +caffeine spot +21 hydroxide is officially germline you + + align:start position:0% +21 hydroxide is officially germline you + + + align:start position:0% +21 hydroxide is officially germline you +can do the blood + + align:start position:0% +can do the blood + + + align:start position:0% +can do the blood +classified cancer blood is not in my + + align:start position:0% +classified cancer blood is not in my + + + align:start position:0% +classified cancer blood is not in my +hands you need a hunk of that cancer or + + align:start position:0% +hands you need a hunk of that cancer or + + + align:start position:0% +hands you need a hunk of that cancer or +depends + + align:start position:0% +depends + + + align:start position:0% +depends +is it a highly inherited cancer or do + + align:start position:0% +is it a highly inherited cancer or do + + + align:start position:0% +is it a highly inherited cancer or do +you believe it's a somatic mutation in + + align:start position:0% +you believe it's a somatic mutation in + + + align:start position:0% +you believe it's a somatic mutation in +the cancer all the point i'm making here + + align:start position:0% +the cancer all the point i'm making here + + + align:start position:0% +the cancer all the point i'm making here +is it's not obvious + + align:start position:0% +is it's not obvious + + + align:start position:0% +is it's not obvious +what you put into the tube + + align:start position:0% +what you put into the tube + + + align:start position:0% +what you put into the tube +and that as dumb as it sounds when + + align:start position:0% +and that as dumb as it sounds when + + + align:start position:0% +and that as dumb as it sounds when +you're a tired resident on the ward and + + align:start position:0% +you're a tired resident on the ward and + + + align:start position:0% +you're a tired resident on the ward and +someone says do the genetic test you + + align:start position:0% +someone says do the genetic test you + + + align:start position:0% +someone says do the genetic test you +don't know what the hell to do + + align:start position:0% +don't know what the hell to do + + + align:start position:0% +don't know what the hell to do +this it's that simple but this is a but + + align:start position:0% +this it's that simple but this is a but + + + align:start position:0% +this it's that simple but this is a but +this is what comes down to genomic + + align:start position:0% +this is what comes down to genomic + + + align:start position:0% +this is what comes down to genomic +medicine you have these are actually + + align:start position:0% +medicine you have these are actually + + + align:start position:0% +medicine you have these are actually +ansible questions but you need some + + align:start position:0% +ansible questions but you need some + + + align:start position:0% +ansible questions but you need some +reading you know where are the mutations + + align:start position:0% +reading you know where are the mutations + + + align:start position:0% +reading you know where are the mutations +and what where do i know and what do + + align:start position:0% +and what where do i know and what do + + + align:start position:0% +and what where do i know and what do +they mean when they are in certain + + align:start position:0% +they mean when they are in certain + + + align:start position:0% +they mean when they are in certain +tissues + + align:start position:0% +tissues + + + align:start position:0% +tissues +so for diseases + + align:start position:0% + + + + align:start position:0% + +germline diseases + + align:start position:0% +germline diseases + + + align:start position:0% +germline diseases +for germa for germline disease you can + + align:start position:0% +for germa for germline disease you can + + + align:start position:0% +for germa for germline disease you can +any tissue doesn't matter so you want + + align:start position:0% +any tissue doesn't matter so you want + + + align:start position:0% +any tissue doesn't matter so you want +one that is the least invasive blood + + align:start position:0% +one that is the least invasive blood + + + align:start position:0% +one that is the least invasive blood +swab even spit sometimes + + align:start position:0% +swab even spit sometimes + + + align:start position:0% +swab even spit sometimes +but for some other complex diseases + + align:start position:0% +but for some other complex diseases + + + align:start position:0% +but for some other complex diseases +where people suspect that you have + + align:start position:0% +where people suspect that you have + + + align:start position:0% +where people suspect that you have +susceptibility which then triggers + + align:start position:0% + + + + align:start position:0% + +well it's gonna be certainly not true + + align:start position:0% +well it's gonna be certainly not true + + + align:start position:0% +well it's gonna be certainly not true +for many diseases but for instance when + + align:start position:0% +for many diseases but for instance when + + + align:start position:0% +for many diseases but for instance when +scott weiss talks about asthma he's + + align:start position:0% +scott weiss talks about asthma he's + + + align:start position:0% +scott weiss talks about asthma he's +thinking of a risk factor even if it's a + + align:start position:0% +thinking of a risk factor even if it's a + + + align:start position:0% +thinking of a risk factor even if it's a +small risk factor you know increase your + + align:start position:0% +small risk factor you know increase your + + + align:start position:0% +small risk factor you know increase your +risk of asthma by 1.2 + + align:start position:0% +risk of asthma by 1.2 + + + align:start position:0% +risk of asthma by 1.2 +he's still thinking of this as a + + align:start position:0% +he's still thinking of this as a + + + align:start position:0% +he's still thinking of this as a +germline + + align:start position:0% +germline + + + align:start position:0% +germline +uh a germline polymorphism now it may be + + align:start position:0% +uh a germline polymorphism now it may be + + + align:start position:0% +uh a germline polymorphism now it may be +that there's that people with asthma i'm + + align:start position:0% +that there's that people with asthma i'm + + + align:start position:0% +that there's that people with asthma i'm +just making up something that's + + align:start position:0% +just making up something that's + + + align:start position:0% +just making up something that's +completely off the off the beaten path + + align:start position:0% +completely off the off the beaten path + + + align:start position:0% +completely off the off the beaten path +is in fact a somatic mutation i doubt it + + align:start position:0% +is in fact a somatic mutation i doubt it + + + align:start position:0% +is in fact a somatic mutation i doubt it +but + + align:start position:0% +but + + + align:start position:0% +but +all these genotyping studies haplotype + + align:start position:0% +all these genotyping studies haplotype + + + align:start position:0% +all these genotyping studies haplotype +studies are done off of blood so they're + + align:start position:0% +studies are done off of blood so they're + + + align:start position:0% +studies are done off of blood so they're +assuming it these are germline diseases + + align:start position:0% +assuming it these are germline diseases + + + align:start position:0% +assuming it these are germline diseases +so for something that's not + + align:start position:0% +so for something that's not + + + align:start position:0% +so for something that's not +yeah something that maybe you've got a + + align:start position:0% +yeah something that maybe you've got a + + + align:start position:0% +yeah something that maybe you've got a +disease because you're exposed to some + + align:start position:0% +disease because you're exposed to some + + + align:start position:0% +disease because you're exposed to some +sort right + + align:start position:0% +sort right + + + align:start position:0% +sort right +well + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +just any other tissue + + align:start position:0% +just any other tissue + + + align:start position:0% +just any other tissue +or blood sure or something like that to + + align:start position:0% +or blood sure or something like that to + + + align:start position:0% +or blood sure or something like that to +be able to i mean the short answer is + + align:start position:0% +be able to i mean the short answer is + + + align:start position:0% +be able to i mean the short answer is +cost but + + align:start position:0% +cost but + + + align:start position:0% +cost but +yes i mean the answer is well i mean + + align:start position:0% +yes i mean the answer is well i mean + + + align:start position:0% +yes i mean the answer is well i mean +wasn't it wise who said that in the next + + align:start position:0% +wasn't it wise who said that in the next + + + align:start position:0% +wasn't it wise who said that in the next +five years + + align:start position:0% + + + + align:start position:0% + +it's not an issue for him to research + + align:start position:0% +it's not an issue for him to research + + + align:start position:0% +it's not an issue for him to research +um + + align:start position:0% +um + + + align:start position:0% +um +it's uh + + align:start position:0% +it's uh + + + align:start position:0% +it's uh +you know what i just told you is you + + align:start position:0% +you know what i just told you is you + + + align:start position:0% +you know what i just told you is you +know 10 cents a genotype today + + align:start position:0% +know 10 cents a genotype today + + + align:start position:0% +know 10 cents a genotype today +for scott weiss + + align:start position:0% +for scott weiss + + + align:start position:0% +for scott weiss +for you my friend one thousand dollars + + align:start position:0% +for you my friend one thousand dollars + + + align:start position:0% +for you my friend one thousand dollars +in the clinic + + align:start position:0% +in the clinic + + + align:start position:0% +in the clinic +and that's by the way that's a huge + + align:start position:0% +and that's by the way that's a huge + + + align:start position:0% +and that's by the way that's a huge +commercial opportunity obviously that + + align:start position:0% +commercial opportunity obviously that + + + align:start position:0% +commercial opportunity obviously that +you're absolutely right that's gonna + + align:start position:0% +you're absolutely right that's gonna + + + align:start position:0% +you're absolutely right that's gonna +drop it's not gonna drop to ten cents + + align:start position:0% +drop it's not gonna drop to ten cents + + + align:start position:0% +drop it's not gonna drop to ten cents +it's gonna drop to ten dollars a hundred + + align:start position:0% +it's gonna drop to ten dollars a hundred + + + align:start position:0% +it's gonna drop to ten dollars a hundred +dollars and the market leaders in that + + align:start position:0% +dollars and the market leaders in that + + + align:start position:0% +dollars and the market leaders in that +who can figure out how to make the bucks + + align:start position:0% +who can figure out how to make the bucks + + + align:start position:0% +who can figure out how to make the bucks +on this + + align:start position:0% +on this + + + align:start position:0% +on this +at that level are going to be + + align:start position:0% +at that level are going to be + + + align:start position:0% +at that level are going to be +extremely rich + + align:start position:0% +extremely rich + + + align:start position:0% +extremely rich +so but and then you need to have okay so + + align:start position:0% +so but and then you need to have okay so + + + align:start position:0% +so but and then you need to have okay so +if you order the test you don't need to + + align:start position:0% +if you order the test you don't need to + + + align:start position:0% +if you order the test you don't need to +get advice on that genetic test + + align:start position:0% +get advice on that genetic test + + + align:start position:0% +get advice on that genetic test +where are you going to get that + + align:start position:0% +where are you going to get that + + + align:start position:0% +where are you going to get that +found either in your office let me tell + + align:start position:0% +found either in your office let me tell + + + align:start position:0% +found either in your office let me tell +you off of that extremely unlikely + + align:start position:0% +you off of that extremely unlikely + + + align:start position:0% +you off of that extremely unlikely +there's no one in my office that's going + + align:start position:0% +there's no one in my office that's going + + + align:start position:0% +there's no one in my office that's going +to give you uh genetic counseling + + align:start position:0% +to give you uh genetic counseling + + + align:start position:0% +to give you uh genetic counseling +or other licensed counselors maybe as + + align:start position:0% +or other licensed counselors maybe as + + + align:start position:0% +or other licensed counselors maybe as +part of your institution i'm talking + + align:start position:0% +part of your institution i'm talking + + + align:start position:0% +part of your institution i'm talking +about today we're not talking about the + + align:start position:0% +about today we're not talking about the + + + align:start position:0% +about today we're not talking about the +medical journalism this view i mean i + + align:start position:0% +medical journalism this view i mean i + + + align:start position:0% +medical journalism this view i mean i +promise you today what are you gonna do + + align:start position:0% +promise you today what are you gonna do + + + align:start position:0% +promise you today what are you gonna do +or licensed counselors at the brigham or + + align:start position:0% +or licensed counselors at the brigham or + + + align:start position:0% +or licensed counselors at the brigham or +you outsource it and here you know it + + align:start position:0% +you outsource it and here you know it + + + align:start position:0% +you outsource it and here you know it +says there's a pretest email phone + + align:start position:0% +says there's a pretest email phone + + + align:start position:0% +says there's a pretest email phone +consultation provided patients and so on + + align:start position:0% +consultation provided patients and so on + + + align:start position:0% +consultation provided patients and so on +and that might be part of the business + + align:start position:0% +and that might be part of the business + + + align:start position:0% +and that might be part of the business +model that uh they understand that a lot + + align:start position:0% +model that uh they understand that a lot + + + align:start position:0% +model that uh they understand that a lot +of institutions don't have that + + align:start position:0% +of institutions don't have that + + + align:start position:0% +of institutions don't have that +that facility so they can outsource it + + align:start position:0% +that facility so they can outsource it + + + align:start position:0% +that facility so they can outsource it +so how do you send a store for sending + + align:start position:0% +so how do you send a store for sending + + + align:start position:0% +so how do you send a store for sending +again these are stupid things that most + + align:start position:0% +again these are stupid things that most + + + align:start position:0% +again these are stupid things that most +residents don't know 310 milliliters of + + align:start position:0% +residents don't know 310 milliliters of + + + align:start position:0% +residents don't know 310 milliliters of +whole blood if it's a germ line and a + + align:start position:0% +whole blood if it's a germ line and a + + + align:start position:0% +whole blood if it's a germ line and a +purple top tube also acceptable green uh + + align:start position:0% +purple top tube also acceptable green uh + + + align:start position:0% +purple top tube also acceptable green uh +green which is sodium heparin or light + + align:start position:0% +green which is sodium heparin or light + + + align:start position:0% +green which is sodium heparin or light +blue sodium citrate tubes + + align:start position:0% +blue sodium citrate tubes + + + align:start position:0% +blue sodium citrate tubes +you know + + align:start position:0% +you know + + + align:start position:0% +you know +it comes down to that what tube you put + + align:start position:0% +it comes down to that what tube you put + + + align:start position:0% +it comes down to that what tube you put +it in if you put in the wrong tube + + align:start position:0% + + + + align:start position:0% + +you you may not have a uh + + align:start position:0% +you you may not have a uh + + + align:start position:0% +you you may not have a uh +adequate extraction + + align:start position:0% +adequate extraction + + + align:start position:0% +adequate extraction +and it's totally different of course for + + align:start position:0% +and it's totally different of course for + + + align:start position:0% +and it's totally different of course for +rna if you're interested in rna you + + align:start position:0% +rna if you're interested in rna you + + + align:start position:0% +rna if you're interested in rna you +better + + align:start position:0% +better + + + align:start position:0% +better +uh + + align:start position:0% +uh + + + align:start position:0% +uh +flash freeze it as a short answer as + + align:start position:0% +flash freeze it as a short answer as + + + align:start position:0% +flash freeze it as a short answer as +soon as you can + + align:start position:0% +soon as you can + + + align:start position:0% +soon as you can +so what kind of dna + + align:start position:0% + + + + align:start position:0% + +because basically the amount of + + align:start position:0% +because basically the amount of + + + align:start position:0% +because basically the amount of +the amount of the stability and + + align:start position:0% +the amount of the stability and + + + align:start position:0% +the amount of the stability and +extractability is going to depend + + align:start position:0% +extractability is going to depend + + + align:start position:0% +extractability is going to depend +on + + align:start position:0% +on + + + align:start position:0% +on +what is inside the tube + + align:start position:0% +what is inside the tube + + + align:start position:0% +what is inside the tube +and the color of the tube tells is the + + align:start position:0% +and the color of the tube tells is the + + + align:start position:0% +and the color of the tube tells is the +code of what's inside the tube + + align:start position:0% +code of what's inside the tube + + + align:start position:0% +code of what's inside the tube +so these tubes are not all uh + + align:start position:0% +so these tubes are not all uh + + + align:start position:0% +so these tubes are not all uh +featureless glass actually they have a + + align:start position:0% +featureless glass actually they have a + + + align:start position:0% +featureless glass actually they have a +little bit of chemical in them + + align:start position:0% +little bit of chemical in them + + + align:start position:0% +little bit of chemical in them +so what kind of dna testing should be + + align:start position:0% +so what kind of dna testing should be + + + align:start position:0% +so what kind of dna testing should be +done + + align:start position:0% +done + + + align:start position:0% +done +so let me ask you guys + + align:start position:0% +so let me ask you guys + + + align:start position:0% +so let me ask you guys +we've just uh got together in a happy + + align:start position:0% +we've just uh got together in a happy + + + align:start position:0% +we've just uh got together in a happy +company called five one five five one + + align:start position:0% +company called five one five five one + + + align:start position:0% +company called five one five five one +two genomic testing + + align:start position:0% +two genomic testing + + + align:start position:0% +two genomic testing +we've uh got our stock options + + align:start position:0% +we've uh got our stock options + + + align:start position:0% +we've uh got our stock options +and um + + align:start position:0% +and um + + + align:start position:0% +and um +what are we gonna do are we gonna + + align:start position:0% +what are we gonna do are we gonna + + + align:start position:0% +what are we gonna do are we gonna +sequence these genes when someone sends + + align:start position:0% +sequence these genes when someone sends + + + align:start position:0% +sequence these genes when someone sends +us a gene to 512 genomics i'm going to + + align:start position:0% +us a gene to 512 genomics i'm going to + + + align:start position:0% +us a gene to 512 genomics i'm going to +sequence it + + align:start position:0% +sequence it + + + align:start position:0% +sequence it +let's say or are we going to genotype it + + align:start position:0% +let's say or are we going to genotype it + + + align:start position:0% +let's say or are we going to genotype it +for all the known mutations what are we + + align:start position:0% +for all the known mutations what are we + + + align:start position:0% +for all the known mutations what are we +going to do + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +jose let me push you so + + align:start position:0% +jose let me push you so + + + align:start position:0% +jose let me push you so +just arrived in our uh inbox is a bl is + + align:start position:0% +just arrived in our uh inbox is a bl is + + + align:start position:0% +just arrived in our uh inbox is a bl is +a blood sample in the right tube + + align:start position:0% +a blood sample in the right tube + + + align:start position:0% +a blood sample in the right tube +from + + align:start position:0% +from + + + align:start position:0% +from +jill schmo + + align:start position:0% +jill schmo + + + align:start position:0% +jill schmo +who just just remote that's really her + + align:start position:0% +who just just remote that's really her + + + align:start position:0% +who just just remote that's really her +baby's blood and she wants to know does + + align:start position:0% +baby's blood and she wants to know does + + + align:start position:0% +baby's blood and she wants to know does +this baby have 21 hydroxylase uh + + align:start position:0% +this baby have 21 hydroxylase uh + + + align:start position:0% +this baby have 21 hydroxylase uh +deficiency and they heard that 512 uh + + align:start position:0% +deficiency and they heard that 512 uh + + + align:start position:0% +deficiency and they heard that 512 uh +genomics is a very smart company because + + align:start position:0% +genomics is a very smart company because + + + align:start position:0% +genomics is a very smart company because +they've been trained at harvard medical + + align:start position:0% +they've been trained at harvard medical + + + align:start position:0% +they've been trained at harvard medical +school + + align:start position:0% +school + + + align:start position:0% +school +and therefore + + align:start position:0% +and therefore + + + align:start position:0% +and therefore +they trust us to do it so you can do a + + align:start position:0% +they trust us to do it so you can do a + + + align:start position:0% +they trust us to do it so you can do a +panel of + + align:start position:0% +panel of + + + align:start position:0% +panel of +what + + align:start position:0% +what + + + align:start position:0% +what +genes + + align:start position:0% +genes + + + align:start position:0% +genes +uh + + align:start position:0% +uh + + + align:start position:0% +uh +let's say + + align:start position:0% +let's say + + + align:start position:0% +let's say +let's simplify your life i'm not gonna + + align:start position:0% +let's simplify your life i'm not gonna + + + align:start position:0% +let's simplify your life i'm not gonna +well + + align:start position:0% +well + + + align:start position:0% +well +first of all i'm gonna test all genes + + align:start position:0% + + + + align:start position:0% + +okay i want us to have a very nice um + + align:start position:0% +okay i want us to have a very nice um + + + align:start position:0% +okay i want us to have a very nice um +corporate vacation bermuda so all the + + align:start position:0% +corporate vacation bermuda so all the + + + align:start position:0% +corporate vacation bermuda so all the +money that we spend is going to um + + align:start position:0% +money that we spend is going to um + + + align:start position:0% +money that we spend is going to um +uh take away from the the bennies i can + + align:start position:0% +uh take away from the the bennies i can + + + align:start position:0% +uh take away from the the bennies i can +give you in our under on our vacation so + + align:start position:0% +give you in our under on our vacation so + + + align:start position:0% +give you in our under on our vacation so +we're gonna do okay we'll do i'm gonna + + align:start position:0% +we're gonna do okay we'll do i'm gonna + + + align:start position:0% +we're gonna do okay we'll do i'm gonna +tell you those five genes that are that + + align:start position:0% +tell you those five genes that are that + + + align:start position:0% +tell you those five genes that are that +calls we're gonna do all five genes + + align:start position:0% + + + + align:start position:0% + +okay so i'm gonna tell you those two + + align:start position:0% +okay so i'm gonna tell you those two + + + align:start position:0% +okay so i'm gonna tell you those two +genes which account for 99 + + align:start position:0% +genes which account for 99 + + + align:start position:0% +genes which account for 99 +good enough for us + + align:start position:0% +good enough for us + + + align:start position:0% +good enough for us +okay let's say yes + + align:start position:0% +okay let's say yes + + + align:start position:0% +okay let's say yes +let's say yes why can't we just do + + align:start position:0% +let's say yes why can't we just do + + + align:start position:0% +let's say yes why can't we just do +one gene that comes back and if we know + + align:start position:0% +one gene that comes back and if we know + + + align:start position:0% +one gene that comes back and if we know +two is too compromised nine percent + + align:start position:0% +two is too compromised nine percent + + + align:start position:0% +two is too compromised nine percent +we're going to do the one because i can + + align:start position:0% +we're going to do the one because i can + + + align:start position:0% +we're going to do the one because i can +negatively do it but don't have positive + + align:start position:0% +negatively do it but don't have positive + + + align:start position:0% +negatively do it but don't have positive +something + + align:start position:0% +something + + + align:start position:0% +something +we've got this + + align:start position:0% +we've got this + + + align:start position:0% +we've got this +put together we're going to go back to + + align:start position:0% +put together we're going to go back to + + + align:start position:0% +put together we're going to go back to +the patient + + align:start position:0% +the patient + + + align:start position:0% +the patient +um that doesn't happen we're we're we're + + align:start position:0% +um that doesn't happen we're we're we're + + + align:start position:0% +um that doesn't happen we're we're we're +we're a lab doesn't we're not the doctor + + align:start position:0% +we're a lab doesn't we're not the doctor + + + align:start position:0% +we're a lab doesn't we're not the doctor +that does not happen + + align:start position:0% +that does not happen + + + align:start position:0% +that does not happen +we have nowhere we cannot ask we unless + + align:start position:0% +we have nowhere we cannot ask we unless + + + align:start position:0% +we have nowhere we cannot ask we unless +you really want to change we live in in + + align:start position:0% +you really want to change we live in in + + + align:start position:0% +you really want to change we live in in +the dream world + + align:start position:0% + + + + align:start position:0% + +your first sequence you know i mean just + + align:start position:0% +your first sequence you know i mean just + + + align:start position:0% +your first sequence you know i mean just +first sequence the more common gene is + + align:start position:0% +first sequence the more common gene is + + + align:start position:0% +first sequence the more common gene is +that what you're saying yeah so you've + + align:start position:0% +that what you're saying yeah so you've + + + align:start position:0% +that what you're saying yeah so you've +got two genes i guess okay so let me + + align:start position:0% +got two genes i guess okay so let me + + + align:start position:0% +got two genes i guess okay so let me +tell you listen to the facts one + + align:start position:0% +tell you listen to the facts one + + + align:start position:0% +tell you listen to the facts one +hydroxides account for 95 percent + + align:start position:0% +hydroxides account for 95 percent + + + align:start position:0% +hydroxides account for 95 percent +11 hydrox + + align:start position:0% +11 hydrox + + + align:start position:0% +11 hydrox +4 so we've got 99 with those two genes + + align:start position:0% +4 so we've got 99 with those two genes + + + align:start position:0% +4 so we've got 99 with those two genes +so what am i actually doing i'm not a + + align:start position:0% +so what am i actually doing i'm not a + + + align:start position:0% +so what am i actually doing i'm not a +laboratory technician + + align:start position:0% +laboratory technician + + + align:start position:0% +laboratory technician +okay and it's it's negative what do i do + + align:start position:0% +okay and it's it's negative what do i do + + + align:start position:0% +okay and it's it's negative what do i do +now and you do the then you do the next + + align:start position:0% +now and you do the then you do the next + + + align:start position:0% +now and you do the then you do the next +one + + align:start position:0% +one + + + align:start position:0% +one +right then + + align:start position:0% +right then + + + align:start position:0% +right then +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +i don't know enough what the v + + align:start position:0% +i don't know enough what the v + + + align:start position:0% +i don't know enough what the v +you know assuming that that a positive + + align:start position:0% +you know assuming that that a positive + + + align:start position:0% +you know assuming that that a positive +the positive is important positive is + + align:start position:0% +the positive is important positive is + + + align:start position:0% +the positive is important positive is +very important so that then you just + + align:start position:0% +very important so that then you just + + + align:start position:0% +very important so that then you just +stay running that extra sense + + align:start position:0% +stay running that extra sense + + + align:start position:0% +stay running that extra sense +okay so you're doing a phase one that's + + align:start position:0% +okay so you're doing a phase one that's + + + align:start position:0% +okay so you're doing a phase one that's +perfectly simple but it probably means + + align:start position:0% +perfectly simple but it probably means + + + align:start position:0% +perfectly simple but it probably means +that most of the time we'll run to both + + align:start position:0% +that most of the time we'll run to both + + + align:start position:0% +that most of the time we'll run to both +tests because most of the time + + align:start position:0% +tests because most of the time + + + align:start position:0% +tests because most of the time +we'll probably get referrals of patients + + align:start position:0% +we'll probably get referrals of patients + + + align:start position:0% +we'll probably get referrals of patients +who don't have that disease so it's a + + align:start position:0% +who don't have that disease so it's a + + + align:start position:0% +who don't have that disease so it's a +small but important incremental savings + + align:start position:0% +small but important incremental savings + + + align:start position:0% +small but important incremental savings +you just gave us you took hoses advice + + align:start position:0% +you just gave us you took hoses advice + + + align:start position:0% +you just gave us you took hoses advice +and say let's only took let's only do + + align:start position:0% +and say let's only took let's only do + + + align:start position:0% +and say let's only took let's only do +one of the gene and if that's negative + + align:start position:0% +one of the gene and if that's negative + + + align:start position:0% +one of the gene and if that's negative +we'll do the second gene but as i just + + align:start position:0% +we'll do the second gene but as i just + + + align:start position:0% +we'll do the second gene but as i just +explained most kids that are sent this + + align:start position:0% +explained most kids that are sent this + + + align:start position:0% +explained most kids that are sent this +was sent for will in fact not + + align:start position:0% +was sent for will in fact not + + + align:start position:0% +was sent for will in fact not +have the disease because it'll be + + align:start position:0% +have the disease because it'll be + + + align:start position:0% +have the disease because it'll be +something else + + align:start position:0% +something else + + + align:start position:0% +something else +and + + align:start position:0% +and + + + align:start position:0% +and +um + + align:start position:0% + + + + align:start position:0% + +what's left of the second one you got a + + align:start position:0% +what's left of the second one you got a + + + align:start position:0% +what's left of the second one you got a +question a question this is a pcr based + + align:start position:0% +question a question this is a pcr based + + + align:start position:0% +question a question this is a pcr based +password + + align:start position:0% +password + + + align:start position:0% +password +well we haven't gone there yet okay okay + + align:start position:0% +well we haven't gone there yet okay okay + + + align:start position:0% +well we haven't gone there yet okay okay +okay so let's say that we take the + + align:start position:0% +okay so let's say that we take the + + + align:start position:0% +okay so let's say that we take the +modification of the jose protocol + + align:start position:0% +modification of the jose protocol + + + align:start position:0% +modification of the jose protocol +so what are we going to do so we'll look + + align:start position:0% +so what are we going to do so we'll look + + + align:start position:0% +so what are we going to do so we'll look +at one gene and then two genes so what + + align:start position:0% +at one gene and then two genes so what + + + align:start position:0% +at one gene and then two genes so what +actually are we going to measure are we + + align:start position:0% +actually are we going to measure are we + + + align:start position:0% +actually are we going to measure are we +going to measure + + align:start position:0% +going to measure + + + align:start position:0% +going to measure +um + + align:start position:0% +um + + + align:start position:0% +um +the full sequence of these genes + + align:start position:0% +the full sequence of these genes + + + align:start position:0% +the full sequence of these genes +are we going to just look at the known + + align:start position:0% +are we going to just look at the known + + + align:start position:0% +are we going to just look at the known +published mutations or snips what are we + + align:start position:0% +published mutations or snips what are we + + + align:start position:0% +published mutations or snips what are we +going to do + + align:start position:0% + + + + align:start position:0% + +now what if i tell you + + align:start position:0% +now what if i tell you + + + align:start position:0% +now what if i tell you +that two-thirds + + align:start position:0% +that two-thirds + + + align:start position:0% +that two-thirds +of the mutations are extremely common + + align:start position:0% +of the mutations are extremely common + + + align:start position:0% +of the mutations are extremely common +and one-third of them are one of a kind + + align:start position:0% + + + + align:start position:0% + +i'm assuming we know something about + + align:start position:0% +i'm assuming we know something about + + + align:start position:0% +i'm assuming we know something about +the + + align:start position:0% +the + + + align:start position:0% +the +the frequency of having the disease and + + align:start position:0% +the frequency of having the disease and + + + align:start position:0% +the frequency of having the disease and +it's associated with the frequency of + + align:start position:0% +it's associated with the frequency of + + + align:start position:0% +it's associated with the frequency of +having that particular communication yes + + align:start position:0% +having that particular communication yes + + + align:start position:0% +having that particular communication yes +so if we know + + align:start position:0% +so if we know + + + align:start position:0% +so if we know +if we know that + + align:start position:0% +if we know that + + + align:start position:0% +if we know that +that a particular mutation say it's the + + align:start position:0% +that a particular mutation say it's the + + + align:start position:0% +that a particular mutation say it's the +one + + align:start position:0% +one + + + align:start position:0% +one +um has a very high incidence of + + align:start position:0% +um has a very high incidence of + + + align:start position:0% +um has a very high incidence of +progressing through the disease but not + + align:start position:0% +progressing through the disease but not + + + align:start position:0% +progressing through the disease but not +the same that you want to find again + + align:start position:0% +the same that you want to find again + + + align:start position:0% +the same that you want to find again +okay i'm joe schmo + + align:start position:0% +okay i'm joe schmo + + + align:start position:0% +okay i'm joe schmo +my kid actually had one of those rare + + align:start position:0% +my kid actually had one of those rare + + + align:start position:0% +my kid actually had one of those rare +ones + + align:start position:0% + + + + align:start position:0% + +i'm gonna sue you your pants off + + align:start position:0% +i'm gonna sue you your pants off + + + align:start position:0% +i'm gonna sue you your pants off +i'm gonna take my i'm taking the + + align:start position:0% +i'm gonna take my i'm taking the + + + align:start position:0% +i'm gonna take my i'm taking the +vacation to bermuda because you guys + + align:start position:0% +vacation to bermuda because you guys + + + align:start position:0% +vacation to bermuda because you guys +uh took there was a known rare mutation + + align:start position:0% +uh took there was a known rare mutation + + + align:start position:0% +uh took there was a known rare mutation +or even no no so wait again this is this + + align:start position:0% +or even no no so wait again this is this + + + align:start position:0% +or even no no so wait again this is this +is this is + + align:start position:0% +is this is + + + align:start position:0% +is this is +back to what i said in the jose + + align:start position:0% +back to what i said in the jose + + + align:start position:0% +back to what i said in the jose +modification if you come back negative + + align:start position:0% +modification if you come back negative + + + align:start position:0% +modification if you come back negative +right um + + align:start position:0% + + + + align:start position:0% + +refinement is still going to cause most + + align:start position:0% +refinement is still going to cause most + + + align:start position:0% +refinement is still going to cause most +of the time + + align:start position:0% +of the time + + + align:start position:0% +of the time +you're going to end up doing all all the + + align:start position:0% +you're going to end up doing all all the + + + align:start position:0% +you're going to end up doing all all the +mutations + + align:start position:0% +mutations + + + align:start position:0% +mutations +well but the alternative is to just do + + align:start position:0% +well but the alternative is to just do + + + align:start position:0% +well but the alternative is to just do +all the mutations all the time + + align:start position:0% +all the mutations all the time + + + align:start position:0% +all the mutations all the time +what i'm telling you + + align:start position:0% +what i'm telling you + + + align:start position:0% +what i'm telling you +what i'm telling you third of them are + + align:start position:0% +what i'm telling you third of them are + + + align:start position:0% +what i'm telling you third of them are +unique + + align:start position:0% +unique + + + align:start position:0% +unique +what the third of them were kind of + + align:start position:0% +what the third of them were kind of + + + align:start position:0% +what the third of them were kind of +unique + + align:start position:0% +unique + + + align:start position:0% +unique +mutations + + align:start position:0% +mutations + + + align:start position:0% +mutations +so the short answer is i believe the + + align:start position:0% +so the short answer is i believe the + + + align:start position:0% +so the short answer is i believe the +right answer is you've got to sequence + + align:start position:0% +right answer is you've got to sequence + + + align:start position:0% +right answer is you've got to sequence +the whole thing + + align:start position:0% +the whole thing + + + align:start position:0% +the whole thing +i mean there's no value in preemptive + + align:start position:0% +i mean there's no value in preemptive + + + align:start position:0% +i mean there's no value in preemptive +screening + + align:start position:0% + + + + align:start position:0% + +it depends if it's for a given patient + + align:start position:0% +it depends if it's for a given patient + + + align:start position:0% +it depends if it's for a given patient +around the specific problem + + align:start position:0% +around the specific problem + + + align:start position:0% +around the specific problem +i don't think + + align:start position:0% +i don't think + + + align:start position:0% +i don't think +there's that's a very different + + align:start position:0% +there's that's a very different + + + align:start position:0% +there's that's a very different +situation from i'm a public health + + align:start position:0% +situation from i'm a public health + + + align:start position:0% +situation from i'm a public health +authority and i want to screen the + + align:start position:0% +authority and i want to screen the + + + align:start position:0% +authority and i want to screen the +population and or i want to screen the + + align:start position:0% +population and or i want to screen the + + + align:start position:0% +population and or i want to screen the +population and just attack people at + + align:start position:0% +population and just attack people at + + + align:start position:0% +population and just attack people at +risk for this + + align:start position:0% +risk for this + + + align:start position:0% +risk for this +but if you're a doctor with a specific + + align:start position:0% +but if you're a doctor with a specific + + + align:start position:0% +but if you're a doctor with a specific +question + + align:start position:0% +question + + + align:start position:0% +question +i'm beauty bound to actually do maximum + + align:start position:0% +i'm beauty bound to actually do maximum + + + align:start position:0% +i'm beauty bound to actually do maximum +for you + + align:start position:0% + + + + align:start position:0% + +and and consequently um + + align:start position:0% + + + + align:start position:0% + +right period + + align:start position:0% +right period + + + align:start position:0% +right period +it just + + align:start position:0% +it just + + + align:start position:0% +it just +seems but it seems kind of + + align:start position:0% +seems but it seems kind of + + + align:start position:0% +seems but it seems kind of +i've it + + align:start position:0% + + + + align:start position:0% + +counter to what the current practices + + align:start position:0% +counter to what the current practices + + + align:start position:0% +counter to what the current practices +were again standard testing for things + + align:start position:0% +were again standard testing for things + + + align:start position:0% +were again standard testing for things +like for when you have thrombosis + + align:start position:0% +like for when you have thrombosis + + + align:start position:0% +like for when you have thrombosis +first thing they did was a testing for + + align:start position:0% +first thing they did was a testing for + + + align:start position:0% +first thing they did was a testing for +the most common things background line + + align:start position:0% +the most common things background line + + + align:start position:0% +the most common things background line +efficiency and all these different + + align:start position:0% +efficiency and all these different + + + align:start position:0% +efficiency and all these different +things because it's like well if you've + + align:start position:0% +things because it's like well if you've + + + align:start position:0% +things because it's like well if you've +got that then you know + + align:start position:0% +got that then you know + + + align:start position:0% +got that then you know +and you know what's walking through then + + align:start position:0% +and you know what's walking through then + + + align:start position:0% +and you know what's walking through then +you don't need to continue + + align:start position:0% +you don't need to continue + + + align:start position:0% +you don't need to continue +uh because we haven't already had a big + + align:start position:0% +uh because we haven't already had a big + + + align:start position:0% +uh because we haven't already had a big +problem so + + align:start position:0% +problem so + + + align:start position:0% +problem so +that that's sort of i guess like big + + align:start position:0% +that that's sort of i guess like big + + + align:start position:0% +that that's sort of i guess like big +basis beyond micro just if you if you + + align:start position:0% +basis beyond micro just if you if you + + + align:start position:0% +basis beyond micro just if you if you +feel like + + align:start position:0% +feel like + + + align:start position:0% +feel like +you know this this uh joe smile came in + + align:start position:0% +you know this this uh joe smile came in + + + align:start position:0% +you know this this uh joe smile came in +and said well if my kid has this thing + + align:start position:0% +and said well if my kid has this thing + + + align:start position:0% +and said well if my kid has this thing +the the fastest cheapest thing to do + + align:start position:0% +the the fastest cheapest thing to do + + + align:start position:0% +the the fastest cheapest thing to do +would be to test him for the most common + + align:start position:0% +would be to test him for the most common + + + align:start position:0% +would be to test him for the most common +so you see you can do that because the + + align:start position:0% +so you see you can do that because the + + + align:start position:0% +so you see you can do that because the +doctor can actually cut a protocol and + + align:start position:0% +doctor can actually cut a protocol and + + + align:start position:0% +doctor can actually cut a protocol and +actually talk this through the patient + + align:start position:0% +actually talk this through the patient + + + align:start position:0% +actually talk this through the patient +work over the most common ones we're + + align:start position:0% +work over the most common ones we're + + + align:start position:0% +work over the most common ones we're +we're five to twelve we're 501 2 + + align:start position:0% +we're five to twelve we're 501 2 + + + align:start position:0% +we're five to twelve we're 501 2 +genomics + + align:start position:0% +genomics + + + align:start position:0% +genomics +and 512 genomics does not have + + align:start position:0% +and 512 genomics does not have + + + align:start position:0% +and 512 genomics does not have +relationship with a patient + + align:start position:0% +relationship with a patient + + + align:start position:0% +relationship with a patient +and we're duty bound i mean and the + + align:start position:0% +and we're duty bound i mean and the + + + align:start position:0% +and we're duty bound i mean and the +doctor doesn't understand genetics so we + + align:start position:0% +doctor doesn't understand genetics so we + + + align:start position:0% +doctor doesn't understand genetics so we +already established + + align:start position:0% +already established + + + align:start position:0% +already established +uh so i'm again i'm trying to stick to + + align:start position:0% +uh so i'm again i'm trying to stick to + + + align:start position:0% +uh so i'm again i'm trying to stick to + + align:start position:0% + + + align:start position:0% +if if there is a private mutation that + + align:start position:0% +if if there is a private mutation that + + + align:start position:0% +if if there is a private mutation that +the patient substrate finds we're toast + + align:start position:0% + + + + align:start position:0% + +even if we don't then go back + + align:start position:0% +even if we don't then go back + + + align:start position:0% +even if we don't then go back +when are we going to go back no one's + + align:start position:0% +when are we going to go back no one's + + + align:start position:0% +when are we going to go back no one's +going to come back to us + + align:start position:0% + + + + align:start position:0% + +well we basically we're going to follow + + align:start position:0% +well we basically we're going to follow + + + align:start position:0% +well we basically we're going to follow +doctor's orders if if they say we want + + align:start position:0% +doctor's orders if if they say we want + + + align:start position:0% +doctor's orders if if they say we want +if they if they say if they say i want + + align:start position:0% +if they if they say if they say i want + + + align:start position:0% +if they if they say if they say i want +to look at congenital adrenal + + align:start position:0% +to look at congenital adrenal + + + align:start position:0% +to look at congenital adrenal +hyperplasia i think we have to look at + + align:start position:0% +hyperplasia i think we have to look at + + + align:start position:0% +hyperplasia i think we have to look at +every gene known to be a + + align:start position:0% +every gene known to be a + + + align:start position:0% +every gene known to be a +we'll build them accordingly of course + + align:start position:0% +we'll build them accordingly of course + + + align:start position:0% +we'll build them accordingly of course +if they say + + align:start position:0% +if they say + + + align:start position:0% +if they say +um i want to look at 21-hydroxylase gene + + align:start position:0% +um i want to look at 21-hydroxylase gene + + + align:start position:0% +um i want to look at 21-hydroxylase gene +with a sequence to hold our gene now + + align:start position:0% +with a sequence to hold our gene now + + + align:start position:0% +with a sequence to hold our gene now +they specifically say i want to look at + + align:start position:0% +they specifically say i want to look at + + + align:start position:0% +they specifically say i want to look at +just a mutation which i'll never tell us + + align:start position:0% +just a mutation which i'll never tell us + + + align:start position:0% +just a mutation which i'll never tell us +i want + + align:start position:0% +i want + + + align:start position:0% +i want +mutation in codon 32 + + align:start position:0% +mutation in codon 32 + + + align:start position:0% +mutation in codon 32 +we'll do that genotyping + + align:start position:0% +we'll do that genotyping + + + align:start position:0% +we'll do that genotyping +but if the doctor is a standard doctor + + align:start position:0% +but if the doctor is a standard doctor + + + align:start position:0% +but if the doctor is a standard doctor + + align:start position:0% + + + align:start position:0% +and says check 21 hydroxylase gene + + align:start position:0% +and says check 21 hydroxylase gene + + + align:start position:0% +and says check 21 hydroxylase gene +we've got to sequence the whole thing + + align:start position:0% +we've got to sequence the whole thing + + + align:start position:0% +we've got to sequence the whole thing +there there is no choice + + align:start position:0% +there there is no choice + + + align:start position:0% +there there is no choice +otherwise otherwise we're we're toast + + align:start position:0% + + + + align:start position:0% + +so i think uh + + align:start position:0% + + + + align:start position:0% + +yes so i think i the only thing i miss + + align:start position:0% +yes so i think i the only thing i miss + + + align:start position:0% +yes so i think i the only thing i miss +from the slide is that uh for epigenetic + + align:start position:0% +from the slide is that uh for epigenetic + + + align:start position:0% +from the slide is that uh for epigenetic +things like methylation uh + + align:start position:0% +things like methylation uh + + + align:start position:0% +things like methylation uh +we even think about doing that but for + + align:start position:0% +we even think about doing that but for + + + align:start position:0% +we even think about doing that but for +certain diseases like involving printing + + align:start position:0% +certain diseases like involving printing + + + align:start position:0% +certain diseases like involving printing +for instance you want to look at + + align:start position:0% +for instance you want to look at + + + align:start position:0% +for instance you want to look at +methylation + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +pre-flight checklist what is this going + + align:start position:0% +pre-flight checklist what is this going + + + align:start position:0% +pre-flight checklist what is this going +to take to get our clinic up and running + + align:start position:0% +to take to get our clinic up and running + + + align:start position:0% +to take to get our clinic up and running +now we're 5 through 12 clinic not we're + + align:start position:0% +now we're 5 through 12 clinic not we're + + + align:start position:0% +now we're 5 through 12 clinic not we're +not the company anymore + + align:start position:0% +not the company anymore + + + align:start position:0% +not the company anymore +so would you or a staff member be able + + align:start position:0% +so would you or a staff member be able + + + align:start position:0% +so would you or a staff member be able +to be in so i took this from some uh + + align:start position:0% +to be in so i took this from some uh + + + align:start position:0% +to be in so i took this from some uh +very good website i can't remember i + + align:start position:0% +very good website i can't remember i + + + align:start position:0% +very good website i can't remember i +wish i could tell you which one it was + + align:start position:0% +wish i could tell you which one it was + + + align:start position:0% +wish i could tell you which one it was +but one of the things that you need to + + align:start position:0% +but one of the things that you need to + + + align:start position:0% +but one of the things that you need to +do but in order before going would you + + align:start position:0% +do but in order before going would you + + + align:start position:0% +do but in order before going would you +or staff member be able to be an + + align:start position:0% +or staff member be able to be an + + + align:start position:0% +or staff member be able to be an +advocacy resource + + align:start position:0% +advocacy resource + + + align:start position:0% +advocacy resource +is the patient and when appropriate + + align:start position:0% +is the patient and when appropriate + + + align:start position:0% +is the patient and when appropriate +family prepared for either a positive or + + align:start position:0% +family prepared for either a positive or + + + align:start position:0% +family prepared for either a positive or +negative test result + + align:start position:0% +negative test result + + + align:start position:0% +negative test result +does the patient understand the medical + + align:start position:0% +does the patient understand the medical + + + align:start position:0% +does the patient understand the medical +psychological and social ramifications + + align:start position:0% +psychological and social ramifications + + + align:start position:0% +psychological and social ramifications +of the test do you have a referral list + + align:start position:0% +of the test do you have a referral list + + + align:start position:0% +of the test do you have a referral list +of private specialists and or genetic + + align:start position:0% +of private specialists and or genetic + + + align:start position:0% +of private specialists and or genetic +counseling services resolve any issues + + align:start position:0% +counseling services resolve any issues + + + align:start position:0% +counseling services resolve any issues +that cannot be handled in office and + + align:start position:0% +that cannot be handled in office and + + + align:start position:0% +that cannot be handled in office and +these are all things that we have to do + + align:start position:0% +these are all things that we have to do + + + align:start position:0% +these are all things that we have to do +as a clinic before we can even start + + align:start position:0% +as a clinic before we can even start + + + align:start position:0% +as a clinic before we can even start +ordering these tests + + align:start position:0% +ordering these tests + + + align:start position:0% +ordering these tests +and the workflow is as follows for a + + align:start position:0% +and the workflow is as follows for a + + + align:start position:0% +and the workflow is as follows for a +positive test + + align:start position:0% +positive test + + + align:start position:0% +positive test +these are all the things we have to do + + align:start position:0% +these are all the things we have to do + + + align:start position:0% +these are all the things we have to do +now we're a primary care practice this + + align:start position:0% +now we're a primary care practice this + + + align:start position:0% +now we're a primary care practice this +and the the interpretation of the + + align:start position:0% +and the the interpretation of the + + + align:start position:0% +and the the interpretation of the +possible result is different and as + + align:start position:0% +possible result is different and as + + + align:start position:0% +possible result is different and as +different if it's a diagnostic test a + + align:start position:0% +different if it's a diagnostic test a + + + align:start position:0% +different if it's a diagnostic test a +predictive test a carry test prenatal + + align:start position:0% +predictive test a carry test prenatal + + + align:start position:0% +predictive test a carry test prenatal +testing or newborn screening + + align:start position:0% +testing or newborn screening + + + align:start position:0% +testing or newborn screening +if it's a positive test and it's + + align:start position:0% +if it's a positive test and it's + + + align:start position:0% +if it's a positive test and it's +diagnostics clinical diagnosis is + + align:start position:0% +diagnostics clinical diagnosis is + + + align:start position:0% +diagnostics clinical diagnosis is +confirmed it's predictive testing it + + align:start position:0% +confirmed it's predictive testing it + + + align:start position:0% +confirmed it's predictive testing it +tells you have increased risk if it's + + align:start position:0% +tells you have increased risk if it's + + + align:start position:0% +tells you have increased risk if it's +carry testing it tells you that you're a + + align:start position:0% +carry testing it tells you that you're a + + + align:start position:0% +carry testing it tells you that you're a +carrier it's prenatal testing it says + + align:start position:0% +carrier it's prenatal testing it says + + + align:start position:0% +carrier it's prenatal testing it says +that the penis has a specific condition + + align:start position:0% +that the penis has a specific condition + + + align:start position:0% +that the penis has a specific condition +and if it's newborn screening it tells + + align:start position:0% +and if it's newborn screening it tells + + + align:start position:0% +and if it's newborn screening it tells +you the + + align:start position:0% +you the + + + align:start position:0% +you the +the the newborn um has a disease and + + align:start position:0% +the the newborn um has a disease and + + + align:start position:0% +the the newborn um has a disease and +the follow-up includes all the things + + align:start position:0% +the follow-up includes all the things + + + align:start position:0% +the follow-up includes all the things +you could imagine + + align:start position:0% +you could imagine + + + align:start position:0% +you could imagine +for negative tests + + align:start position:0% +for negative tests + + + align:start position:0% +for negative tests +if it's a diagnostic test the symptoms + + align:start position:0% +if it's a diagnostic test the symptoms + + + align:start position:0% +if it's a diagnostic test the symptoms +are unexplained + + align:start position:0% +are unexplained + + + align:start position:0% +are unexplained +the likelihood that if it's for + + align:start position:0% +the likelihood that if it's for + + + align:start position:0% +the likelihood that if it's for +predictive testing the likelihood of + + align:start position:0% +predictive testing the likelihood of + + + align:start position:0% +predictive testing the likelihood of +showing symptoms is decreased + + align:start position:0% +showing symptoms is decreased + + + align:start position:0% +showing symptoms is decreased +if it's carrier it's high likely that + + align:start position:0% +if it's carrier it's high likely that + + + align:start position:0% +if it's carrier it's high likely that +you're not a carrier if it's penile + + align:start position:0% +you're not a carrier if it's penile + + + align:start position:0% +you're not a carrier if it's penile +testing + + align:start position:0% +testing + + + align:start position:0% +testing +if the fetus was symptomatic then um + + align:start position:0% +if the fetus was symptomatic then um + + + align:start position:0% +if the fetus was symptomatic then um +it's unexplained if it's not symptomatic + + align:start position:0% +it's unexplained if it's not symptomatic + + + align:start position:0% +it's unexplained if it's not symptomatic +the chance for the test condition is + + align:start position:0% +the chance for the test condition is + + + align:start position:0% +the chance for the test condition is +small and newborn screening excreting + + align:start position:0% +small and newborn screening excreting + + + align:start position:0% +small and newborn screening excreting +the newborn is not tested not expected + + align:start position:0% +the newborn is not tested not expected + + + align:start position:0% +the newborn is not tested not expected +to have the condition there's a whole + + align:start position:0% +to have the condition there's a whole + + + align:start position:0% +to have the condition there's a whole +bunch of follow-up that does or does not + + align:start position:0% +bunch of follow-up that does or does not + + + align:start position:0% +bunch of follow-up that does or does not +develop from these different levels of + + align:start position:0% +develop from these different levels of + + + align:start position:0% +develop from these different levels of +use of the same darn test across these + + align:start position:0% +use of the same darn test across these + + + align:start position:0% +use of the same darn test across these +different clinical states and thinking + + align:start position:0% +different clinical states and thinking + + + align:start position:0% +different clinical states and thinking +about uh 512 512 genomics our old + + align:start position:0% +about uh 512 512 genomics our old + + + align:start position:0% +about uh 512 512 genomics our old +company + + align:start position:0% +company + + + align:start position:0% +company +if we didn't know which one of those + + align:start position:0% +if we didn't know which one of those + + + align:start position:0% +if we didn't know which one of those +situations were involved + + align:start position:0% +situations were involved + + + align:start position:0% +situations were involved +we'd have to practice a very defensive + + align:start position:0% +we'd have to practice a very defensive + + + align:start position:0% +we'd have to practice a very defensive +corporate policy to make sure it was + + align:start position:0% +corporate policy to make sure it was + + + align:start position:0% +corporate policy to make sure it was +we would be in the maximal uh informed + + align:start position:0% +we would be in the maximal uh informed + + + align:start position:0% +we would be in the maximal uh informed +state uh for all uh conditions + + align:start position:0% +state uh for all uh conditions + + + align:start position:0% +state uh for all uh conditions +so can i send a sample for microarray + + align:start position:0% +so can i send a sample for microarray + + + align:start position:0% +so can i send a sample for microarray +testing we've heard so much about + + align:start position:0% +testing we've heard so much about + + + align:start position:0% +testing we've heard so much about +microarrays in this class + + align:start position:0% +microarrays in this class + + + align:start position:0% +microarrays in this class +in the usa the answer is yes for a + + align:start position:0% +in the usa the answer is yes for a + + + align:start position:0% +in the usa the answer is yes for a +research protocol + + align:start position:0% +research protocol + + + align:start position:0% +research protocol +this summer you're going to be able to + + align:start position:0% +this summer you're going to be able to + + + align:start position:0% +this summer you're going to be able to +order at harvard medical school + + align:start position:0% + + + + align:start position:0% + +genotyping with a resequencing array + + align:start position:0% +genotyping with a resequencing array + + + align:start position:0% +genotyping with a resequencing array +for cardiac myopathies and for hearing + + align:start position:0% +for cardiac myopathies and for hearing + + + align:start position:0% +for cardiac myopathies and for hearing +deficiencies + + align:start position:0% +deficiencies + + + align:start position:0% +deficiencies +these are custom chips from aphametrics + + align:start position:0% +these are custom chips from aphametrics + + + align:start position:0% +these are custom chips from aphametrics +and uh for + + align:start position:0% +and uh for + + + align:start position:0% +and uh for +uh certainly for + + align:start position:0% +uh certainly for + + + align:start position:0% +uh certainly for +research protocols we're using them for + + align:start position:0% +research protocols we're using them for + + + align:start position:0% +research protocols we're using them for +expression as well + + align:start position:0% +expression as well + + + align:start position:0% +expression as well +can you do this for commercial testing + + align:start position:0% +can you do this for commercial testing + + + align:start position:0% +can you do this for commercial testing +the answer is no + + align:start position:0% +the answer is no + + + align:start position:0% +the answer is no +roche diagnostics + + align:start position:0% +roche diagnostics + + + align:start position:0% +roche diagnostics +uh + + align:start position:0% +uh + + + align:start position:0% +uh +three months ago tried to get approved + + align:start position:0% +three months ago tried to get approved + + + align:start position:0% +three months ago tried to get approved +through the expedited review of the fda + + align:start position:0% +through the expedited review of the fda + + + align:start position:0% +through the expedited review of the fda +the um + + align:start position:0% + + + + align:start position:0% + +p450 + + align:start position:0% +p450 + + + align:start position:0% +p450 +chip which has all the genes that are + + align:start position:0% +chip which has all the genes that are + + + align:start position:0% +chip which has all the genes that are +involved from metabolizing uh + + align:start position:0% +involved from metabolizing uh + + + align:start position:0% +involved from metabolizing uh +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +toxins and drugs and therefore it's a + + align:start position:0% +toxins and drugs and therefore it's a + + + align:start position:0% +toxins and drugs and therefore it's a +very good pharmacogenomic uh screen and + + align:start position:0% +very good pharmacogenomic uh screen and + + + align:start position:0% +very good pharmacogenomic uh screen and +they were blocked out in their tracks by + + align:start position:0% +they were blocked out in their tracks by + + + align:start position:0% +they were blocked out in their tracks by +the fda so they have to + + align:start position:0% +the fda so they have to + + + align:start position:0% +the fda so they have to +until unless they can appeal it + + align:start position:0% +until unless they can appeal it + + + align:start position:0% +until unless they can appeal it +correctly they will have to go through + + align:start position:0% +correctly they will have to go through + + + align:start position:0% +correctly they will have to go through +full bore expensive + + align:start position:0% +full bore expensive + + + align:start position:0% +full bore expensive +fda approval + + align:start position:0% +fda approval + + + align:start position:0% +fda approval +and why is this so why is this the case + + align:start position:0% +and why is this so why is this the case + + + align:start position:0% +and why is this so why is this the case +i can give you a lot of different + + align:start position:0% +i can give you a lot of different + + + align:start position:0% +i can give you a lot of different +reasons but the short answer the fda + + align:start position:0% +reasons but the short answer the fda + + + align:start position:0% +reasons but the short answer the fda +does not understand this technology + + align:start position:0% +does not understand this technology + + + align:start position:0% +does not understand this technology +and does not know what to do with it i + + align:start position:0% +and does not know what to do with it i + + + align:start position:0% +and does not know what to do with it i +was part of a uh a panel with the fda + + align:start position:0% +was part of a uh a panel with the fda + + + align:start position:0% +was part of a uh a panel with the fda +and by talking about it they have just + + align:start position:0% +and by talking about it they have just + + + align:start position:0% +and by talking about it they have just +agreed right now with a big pharma just + + align:start position:0% +agreed right now with a big pharma just + + + align:start position:0% +agreed right now with a big pharma just +on one of the data structure with which + + align:start position:0% +on one of the data structure with which + + + align:start position:0% +on one of the data structure with which +they can transfer results + + align:start position:0% +they can transfer results + + + align:start position:0% +they can transfer results +let alone interpretation or analyses of + + align:start position:0% +let alone interpretation or analyses of + + + align:start position:0% +let alone interpretation or analyses of +the results so + + align:start position:0% + + + + align:start position:0% + +just because they don't + + align:start position:0% +just because they don't + + + align:start position:0% +just because they don't +understand it even though it's not like + + align:start position:0% +understand it even though it's not like + + + align:start position:0% +understand it even though it's not like +unleashing a new + + align:start position:0% +unleashing a new + + + align:start position:0% +unleashing a new +frog on the population that they don't + + align:start position:0% +frog on the population that they don't + + + align:start position:0% +frog on the population that they don't +understand the side effects and this + + align:start position:0% +understand the side effects and this + + + align:start position:0% +understand the side effects and this +this actually doesn't do anything + + align:start position:0% +this actually doesn't do anything + + + align:start position:0% +this actually doesn't do anything +other than maybe + + align:start position:0% +other than maybe + + + align:start position:0% +other than maybe +give patients something to + + align:start position:0% +give patients something to + + + align:start position:0% +give patients something to +let me give you make it very concrete it + + align:start position:0% +let me give you make it very concrete it + + + align:start position:0% +let me give you make it very concrete it +it gives you a result that the patient + + align:start position:0% +it gives you a result that the patient + + + align:start position:0% +it gives you a result that the patient +then has our ovaries and breasts move + + align:start position:0% +then has our ovaries and breasts move + + + align:start position:0% +then has our ovaries and breasts move +forward + + align:start position:0% + + + + align:start position:0% + +yeah and that's i mean that's what what + + align:start position:0% +yeah and that's i mean that's what what + + + align:start position:0% +yeah and that's i mean that's what what +what it's a classic example of whatever + + align:start position:0% +what it's a classic example of whatever + + + align:start position:0% +what it's a classic example of whatever +the bilateral + + align:start position:0% +the bilateral + + + align:start position:0% +the bilateral +yes + + align:start position:0% + + + + align:start position:0% + +for no reason but that's going to happen + + align:start position:0% +for no reason but that's going to happen + + + align:start position:0% +for no reason but that's going to happen +that's many things are going to happen + + align:start position:0% +that's many things are going to happen + + + align:start position:0% +that's many things are going to happen +like that i mean just going to the + + align:start position:0% +like that i mean just going to the + + + align:start position:0% +like that i mean just going to the +doctor + + align:start position:0% +doctor + + + align:start position:0% +doctor +i try to stay with doctors as much as i + + align:start position:0% +i try to stay with doctors as much as i + + + align:start position:0% +i try to stay with doctors as much as i +can it's probably a bad idea + + align:start position:0% +can it's probably a bad idea + + + align:start position:0% +can it's probably a bad idea +because you probably should get the + + align:start position:0% +because you probably should get the + + + align:start position:0% +because you probably should get the +routine care but + + align:start position:0% +routine care but + + + align:start position:0% +routine care but +um + + align:start position:0% +um + + + align:start position:0% +um +if every time you expose yourself to + + align:start position:0% +if every time you expose yourself to + + + align:start position:0% +if every time you expose yourself to +even an investigative procedure for the + + align:start position:0% +even an investigative procedure for the + + + align:start position:0% +even an investigative procedure for the +wrong reason they're likely to find that + + align:start position:0% +wrong reason they're likely to find that + + + align:start position:0% +wrong reason they're likely to find that +again for the false positive reason + + align:start position:0% +again for the false positive reason + + + align:start position:0% +again for the false positive reason +um + + align:start position:0% +um + + + align:start position:0% +um +things that are incidental but are + + align:start position:0% +things that are incidental but are + + + align:start position:0% +things that are incidental but are +create huge costs and + + align:start position:0% +create huge costs and + + + align:start position:0% +create huge costs and +worry and morbidity you know diagnostic + + align:start position:0% +worry and morbidity you know diagnostic + + + align:start position:0% +worry and morbidity you know diagnostic +tests themselves can kill you + + align:start position:0% +tests themselves can kill you + + + align:start position:0% +tests themselves can kill you +so let's say you're told they have a + + align:start position:0% +so let's say you're told they have a + + + align:start position:0% +so let's say you're told they have a +risk for this and then you you have to + + align:start position:0% +risk for this and then you you have to + + + align:start position:0% +risk for this and then you you have to +then get a a um + + align:start position:0% +then get a a um + + + align:start position:0% +then get a a um +a + + align:start position:0% +a + + + align:start position:0% +a +clause copy + + align:start position:0% +clause copy + + + align:start position:0% +clause copy +a tiny fraction probably one in 200 000 + + align:start position:0% +a tiny fraction probably one in 200 000 + + + align:start position:0% +a tiny fraction probably one in 200 000 +people suffer bad outcomes from + + align:start position:0% +people suffer bad outcomes from + + + align:start position:0% +people suffer bad outcomes from +from that procedure + + align:start position:0% +from that procedure + + + align:start position:0% +from that procedure +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +plus they you know + + align:start position:0% +plus they you know + + + align:start position:0% +plus they you know +those are you know those are painfully + + align:start position:0% +those are you know those are painfully + + + align:start position:0% +those are you know those are painfully +you know what and so um + + align:start position:0% +you know what and so um + + + align:start position:0% +you know what and so um +that's not in success so this is this is + + align:start position:0% +that's not in success so this is this is + + + align:start position:0% +that's not in success so this is this is +a problem so the short answer is + + align:start position:0% +a problem so the short answer is + + + align:start position:0% +a problem so the short answer is +microarray testing no but there's + + align:start position:0% +microarray testing no but there's + + + align:start position:0% +microarray testing no but there's +nothing holy about the fda + + align:start position:0% +nothing holy about the fda + + + align:start position:0% +nothing holy about the fda +in the netherlands + + align:start position:0% +in the netherlands + + + align:start position:0% +in the netherlands +um i don't know again if it's this is uh + + align:start position:0% +um i don't know again if it's this is uh + + + align:start position:0% +um i don't know again if it's this is uh +what i had heard last year around this + + align:start position:0% +what i had heard last year around this + + + align:start position:0% +what i had heard last year around this +time and i don't know if it's happened + + align:start position:0% +time and i don't know if it's happened + + + align:start position:0% +time and i don't know if it's happened +but they were claiming they were going + + align:start position:0% +but they were claiming they were going + + + align:start position:0% +but they were claiming they were going +to routine use of microarray for breast + + align:start position:0% +to routine use of microarray for breast + + + align:start position:0% +to routine use of microarray for breast +uh breast biopsy um screening and + + align:start position:0% +uh breast biopsy um screening and + + + align:start position:0% +uh breast biopsy um screening and +evaluation i have to research to figure + + align:start position:0% +evaluation i have to research to figure + + + align:start position:0% +evaluation i have to research to figure +out whether it's happened or not + + align:start position:0% + + + + align:start position:0% + +and there's of course the issue of + + align:start position:0% +and there's of course the issue of + + + align:start position:0% +and there's of course the issue of +consent + + align:start position:0% +consent + + + align:start position:0% +consent +and and the short answer as we'll get to + + align:start position:0% +and and the short answer as we'll get to + + + align:start position:0% +and and the short answer as we'll get to +uh shortly + + align:start position:0% +uh shortly + + + align:start position:0% +uh shortly +is that you have to do a fairly + + align:start position:0% +is that you have to do a fairly + + + align:start position:0% +is that you have to do a fairly +extensive consent process however if the + + align:start position:0% +extensive consent process however if the + + + align:start position:0% +extensive consent process however if the +patient is symptomatic + + align:start position:0% +patient is symptomatic + + + align:start position:0% +patient is symptomatic +if they have the cancer + + align:start position:0% +if they have the cancer + + + align:start position:0% +if they have the cancer +or a heart attack or they have + + align:start position:0% +or a heart attack or they have + + + align:start position:0% +or a heart attack or they have +dementia they're actually symptomatic + + align:start position:0% +dementia they're actually symptomatic + + + align:start position:0% +dementia they're actually symptomatic +it's much more simple uh consent process + + align:start position:0% +it's much more simple uh consent process + + + align:start position:0% +it's much more simple uh consent process +all the consent issues that you've heard + + align:start position:0% +all the consent issues that you've heard + + + align:start position:0% +all the consent issues that you've heard +about in public press + + align:start position:0% +about in public press + + + align:start position:0% +about in public press +are about pre-symptomatic testing + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +why don't + + align:start position:0% +why don't + + + align:start position:0% +why don't +why don't they just approve the + + align:start position:0% +why don't they just approve the + + + align:start position:0% +why don't they just approve the +pre-symptomatic testing of the cardiac + + align:start position:0% +pre-symptomatic testing of the cardiac + + + align:start position:0% +pre-symptomatic testing of the cardiac +or the you know the + + align:start position:0% +or the you know the + + + align:start position:0% +or the you know the +rule + + align:start position:0% +rule + + + align:start position:0% +rule +that + + align:start position:0% +that + + + align:start position:0% +that +you're just going to follow + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +so let me tell you something about + + align:start position:0% +so let me tell you something about + + + align:start position:0% +so let me tell you something about +medicine that's impossible um if you + + align:start position:0% +medicine that's impossible um if you + + + align:start position:0% +medicine that's impossible um if you +find something + + align:start position:0% +find something + + + align:start position:0% +find something +that is looks bad + + align:start position:0% +that is looks bad + + + align:start position:0% +that is looks bad +um on an mri + + align:start position:0% +um on an mri + + + align:start position:0% +um on an mri +because + + align:start position:0% +because + + + align:start position:0% +because +even if you're if you believe that's + + align:start position:0% +even if you're if you believe that's + + + align:start position:0% +even if you're if you believe that's +only one chance in 100 that is truly a + + align:start position:0% +only one chance in 100 that is truly a + + + align:start position:0% +only one chance in 100 that is truly a +bad thing + + align:start position:0% +bad thing + + + align:start position:0% +bad thing +and something bad happens to that + + align:start position:0% +and something bad happens to that + + + align:start position:0% +and something bad happens to that +patient not only are you toast with the + + align:start position:0% +patient not only are you toast with the + + + align:start position:0% +patient not only are you toast with the +legal system but you'll feel terrible + + align:start position:0% +legal system but you'll feel terrible + + + align:start position:0% +legal system but you'll feel terrible +i mean it's just it can make you very + + align:start position:0% +i mean it's just it can make you very + + + align:start position:0% +i mean it's just it can make you very +very fidgety + + align:start position:0% +very fidgety + + + align:start position:0% +very fidgety +to have a patient with a finding that + + align:start position:0% +to have a patient with a finding that + + + align:start position:0% +to have a patient with a finding that +you're taught medical school + + align:start position:0% +you're taught medical school + + + align:start position:0% +you're taught medical school +is badness so until we complete where + + align:start position:0% +is badness so until we complete where + + + align:start position:0% +is badness so until we complete where +you're and some we're talking 2004 + + align:start position:0% +you're and some we're talking 2004 + + + align:start position:0% +you're and some we're talking 2004 +medical education 2004. we're taught + + align:start position:0% +medical education 2004. we're taught + + + align:start position:0% +medical education 2004. we're taught +that certain bumps on mris mean bad + + align:start position:0% +that certain bumps on mris mean bad + + + align:start position:0% +that certain bumps on mris mean bad +things so if you start changing your + + align:start position:0% +things so if you start changing your + + + align:start position:0% +things so if you start changing your +priors by screening everybody + + align:start position:0% +priors by screening everybody + + + align:start position:0% +priors by screening everybody +then bumps do mean different things but + + align:start position:0% +then bumps do mean different things but + + + align:start position:0% +then bumps do mean different things but +that's not the way we've been educated + + align:start position:0% +that's not the way we've been educated + + + align:start position:0% +that's not the way we've been educated +so we can get it as hell + + align:start position:0% +so we can get it as hell + + + align:start position:0% +so we can get it as hell +so with the advent of + + align:start position:0% +so with the advent of + + + align:start position:0% +so with the advent of +technologies for particular things + + align:start position:0% + + + + align:start position:0% + +that are specific for + + align:start position:0% +that are specific for + + + align:start position:0% +that are specific for +backgrounds + + align:start position:0% + + + + align:start position:0% + +yes except it never really does because + + align:start position:0% +yes except it never really does because + + + align:start position:0% +yes except it never really does because +um + + align:start position:0% +um + + + align:start position:0% +um +i don't + + align:start position:0% +i don't + + + align:start position:0% +i don't +well that's not true for certain things + + align:start position:0% +well that's not true for certain things + + + align:start position:0% +well that's not true for certain things +we're going to get specific enough + + align:start position:0% +we're going to get specific enough + + + align:start position:0% +we're going to get specific enough +um markers you know i can imagine that a + + align:start position:0% +um markers you know i can imagine that a + + + align:start position:0% +um markers you know i can imagine that a +bump + + align:start position:0% +bump + + + align:start position:0% +bump +plus maybe wrongly imagine a bump plus a + + align:start position:0% +plus maybe wrongly imagine a bump plus a + + + align:start position:0% +plus maybe wrongly imagine a bump plus a +functional assay like with a pet scan + + align:start position:0% +functional assay like with a pet scan + + + align:start position:0% +functional assay like with a pet scan +will show that this is a highly uh + + align:start position:0% +will show that this is a highly uh + + + align:start position:0% +will show that this is a highly uh +rapidly dividing thingamajig and + + align:start position:0% +rapidly dividing thingamajig and + + + align:start position:0% +rapidly dividing thingamajig and +therefore it's a problem or it's totally + + align:start position:0% +therefore it's a problem or it's totally + + + align:start position:0% +therefore it's a problem or it's totally +quiescent this metabolic requires and we + + align:start position:0% +quiescent this metabolic requires and we + + + align:start position:0% +quiescent this metabolic requires and we +can just observe it + + align:start position:0% +can just observe it + + + align:start position:0% +can just observe it +so that's possible yes there's like you + + align:start position:0% +so that's possible yes there's like you + + + align:start position:0% +so that's possible yes there's like you +know i just listened to the cultural + + align:start position:0% +know i just listened to the cultural + + + align:start position:0% +know i just listened to the cultural +industry talking about his idea + + align:start position:0% +industry talking about his idea + + + align:start position:0% +industry talking about his idea +why don't we treat cancers before they + + align:start position:0% +why don't we treat cancers before they + + + align:start position:0% +why don't we treat cancers before they +actually he's absolute right and and + + align:start position:0% +actually he's absolute right and and + + + align:start position:0% +actually he's absolute right and and +that sort of thought to me falls right + + align:start position:0% +that sort of thought to me falls right + + + align:start position:0% +that sort of thought to me falls right +in line with this just you know + + align:start position:0% +in line with this just you know + + + align:start position:0% +in line with this just you know +what's the harm in in doing this and now + + align:start position:0% +what's the harm in in doing this and now + + + align:start position:0% +what's the harm in in doing this and now +let's let's let me i've + + align:start position:0% +let's let's let me i've + + + align:start position:0% +let's let's let me i've +i have the greatest respect for judah + + align:start position:0% +i have the greatest respect for judah + + + align:start position:0% +i have the greatest respect for judah +and i'm sure he'd agree with what i'm + + align:start position:0% +and i'm sure he'd agree with what i'm + + + align:start position:0% +and i'm sure he'd agree with what i'm +about to say + + align:start position:0% +about to say + + + align:start position:0% +about to say +it all comes down to + + align:start position:0% +it all comes down to + + + align:start position:0% +it all comes down to +what is the treatment + + align:start position:0% +what is the treatment + + + align:start position:0% +what is the treatment +and who and what threshold do you pick + + align:start position:0% +and who and what threshold do you pick + + + align:start position:0% +and who and what threshold do you pick +so if you're looking at a certain um + + align:start position:0% +so if you're looking at a certain um + + + align:start position:0% +so if you're looking at a certain um +angiogenic signature whether it's a + + align:start position:0% +angiogenic signature whether it's a + + + align:start position:0% +angiogenic signature whether it's a +polymorphism or something that you're + + align:start position:0% +polymorphism or something that you're + + + align:start position:0% +polymorphism or something that you're +measuring what's your plus positive rate + + align:start position:0% +measuring what's your plus positive rate + + + align:start position:0% +measuring what's your plus positive rate +and how toxic is your treatment if your + + align:start position:0% +and how toxic is your treatment if your + + + align:start position:0% +and how toxic is your treatment if your +treatment is totally benign of course + + align:start position:0% +treatment is totally benign of course + + + align:start position:0% +treatment is totally benign of course +treat it everybody + + align:start position:0% +treat it everybody + + + align:start position:0% +treat it everybody +and then cheap it's then treat everybody + + align:start position:0% +and then cheap it's then treat everybody + + + align:start position:0% +and then cheap it's then treat everybody +but + + align:start position:0% +but + + + align:start position:0% +but +that's almost never true + + align:start position:0% +that's almost never true + + + align:start position:0% +that's almost never true +it's not never completely benign and + + align:start position:0% +it's not never completely benign and + + + align:start position:0% +it's not never completely benign and +completely cheap so you end up having to + + align:start position:0% +completely cheap so you end up having to + + + align:start position:0% +completely cheap so you end up having to +make decisions + + align:start position:0% + + + + align:start position:0% + +so now for pre-symptomatic uh asymptotic + + align:start position:0% +so now for pre-symptomatic uh asymptotic + + + align:start position:0% +so now for pre-symptomatic uh asymptotic +testing consent is actually + + align:start position:0% +testing consent is actually + + + align:start position:0% +testing consent is actually +a very very um complex + + align:start position:0% +a very very um complex + + + align:start position:0% +a very very um complex +and drawn-out process so here's what + + align:start position:0% +and drawn-out process so here's what + + + align:start position:0% +and drawn-out process so here's what +it's um what's what is involved again + + align:start position:0% +it's um what's what is involved again + + + align:start position:0% +it's um what's what is involved again +this is 2004 it may change to be more + + align:start position:0% +this is 2004 it may change to be more + + + align:start position:0% +this is 2004 it may change to be more +rigorous or less rigorous depending on + + align:start position:0% +rigorous or less rigorous depending on + + + align:start position:0% +rigorous or less rigorous depending on +whether or not the the genetic privacy + + align:start position:0% +whether or not the the genetic privacy + + + align:start position:0% +whether or not the the genetic privacy +act which is now somewhere in congress + + align:start position:0% +act which is now somewhere in congress + + + align:start position:0% +act which is now somewhere in congress +will be enacted or not + + align:start position:0% +will be enacted or not + + + align:start position:0% +will be enacted or not +so the current + + align:start position:0% +so the current + + + align:start position:0% +so the current +uh state of the art is the major meta + + align:start position:0% +uh state of the art is the major meta + + + align:start position:0% +uh state of the art is the major meta +medical facts including the diagnosis + + align:start position:0% +medical facts including the diagnosis + + + align:start position:0% +medical facts including the diagnosis +the prognosis and the way of treatments + + align:start position:0% +the prognosis and the way of treatments + + + align:start position:0% +the prognosis and the way of treatments +uh and the treatment of disorder tested + + align:start position:0% +uh and the treatment of disorder tested + + + align:start position:0% +uh and the treatment of disorder tested +has been explained to patients the + + align:start position:0% +has been explained to patients the + + + align:start position:0% +has been explained to patients the +genetic facts involving including risks + + align:start position:0% +genetic facts involving including risks + + + align:start position:0% +genetic facts involving including risks +for other family members has to be + + align:start position:0% +for other family members has to be + + + align:start position:0% +for other family members has to be +explained + + align:start position:0% +explained + + + align:start position:0% +explained +uh the chance that the test will give a + + align:start position:0% +uh the chance that the test will give a + + + align:start position:0% +uh the chance that the test will give a +correct prediction as well as + + align:start position:0% +correct prediction as well as + + + align:start position:0% +correct prediction as well as +indeterminate indeterminate or + + align:start position:0% +indeterminate indeterminate or + + + align:start position:0% +indeterminate indeterminate or +unexpected findings has to be explained + + align:start position:0% +unexpected findings has to be explained + + + align:start position:0% +unexpected findings has to be explained +to them the risk of receiving an + + align:start position:0% +to them the risk of receiving an + + + align:start position:0% +to them the risk of receiving an +unfavorable test result and the possible + + align:start position:0% +unfavorable test result and the possible + + + align:start position:0% +unfavorable test result and the possible +consequences for yourself and your + + align:start position:0% +consequences for yourself and your + + + align:start position:0% +consequences for yourself and your +family in the case of prenatal diagnosis + + align:start position:0% +family in the case of prenatal diagnosis + + + align:start position:0% +family in the case of prenatal diagnosis +may include the risk of facing a + + align:start position:0% +may include the risk of facing a + + + align:start position:0% +may include the risk of facing a +decision about abortion and you have to + + align:start position:0% +decision about abortion and you have to + + + align:start position:0% +decision about abortion and you have to +tell them in a way that they really + + align:start position:0% +tell them in a way that they really + + + align:start position:0% +tell them in a way that they really +you know recognize they understand some + + align:start position:0% +you know recognize they understand some + + + align:start position:0% +you know recognize they understand some +people are videotaping these consents + + align:start position:0% +people are videotaping these consents + + + align:start position:0% +people are videotaping these consents +now + + align:start position:0% +now + + + align:start position:0% +now +both to keep the people not both to make + + align:start position:0% +both to keep the people not both to make + + + align:start position:0% +both to keep the people not both to make +sure both defensively and also make sure + + align:start position:0% +sure both defensively and also make sure + + + align:start position:0% +sure both defensively and also make sure +that the practitioners are doing the + + align:start position:0% +that the practitioners are doing the + + + align:start position:0% +that the practitioners are doing the +right thing + + align:start position:0% +right thing + + + align:start position:0% +right thing +alternate you make should be made clear + + align:start position:0% +alternate you make should be made clear + + + align:start position:0% +alternate you make should be made clear +that you can refuse the the test to give + + align:start position:0% +that you can refuse the the test to give + + + align:start position:0% +that you can refuse the the test to give +be inform the potential benefits and + + align:start position:0% +be inform the potential benefits and + + + align:start position:0% +be inform the potential benefits and +disadvantages including unsaid unsettled + + align:start position:0% +disadvantages including unsaid unsettled + + + align:start position:0% +disadvantages including unsaid unsettled +questions of privacy protection dealing + + align:start position:0% +questions of privacy protection dealing + + + align:start position:0% +questions of privacy protection dealing +with insurances banks or employers + + align:start position:0% +with insurances banks or employers + + + align:start position:0% +with insurances banks or employers +we don't know you know you might be able + + align:start position:0% +we don't know you know you might be able + + + align:start position:0% +we don't know you know you might be able +to say today + + align:start position:0% +to say today + + + align:start position:0% +to say today +the um + + align:start position:0% +the um + + + align:start position:0% +the um +the insurance company is not going to do + + align:start position:0% +the insurance company is not going to do + + + align:start position:0% +the insurance company is not going to do +anything with it but that test is now + + align:start position:0% +anything with it but that test is now + + + align:start position:0% +anything with it but that test is now +forever in your medical record it may be + + align:start position:0% +forever in your medical record it may be + + + align:start position:0% +forever in your medical record it may be +not true five years from now that the + + align:start position:0% +not true five years from now that the + + + align:start position:0% +not true five years from now that the +different insurance company or the same + + align:start position:0% +different insurance company or the same + + + align:start position:0% +different insurance company or the same +insurance company will feel differently + + align:start position:0% +insurance company will feel differently + + + align:start position:0% +insurance company will feel differently +your care will not be jeopardized + + align:start position:0% +your care will not be jeopardized + + + align:start position:0% +your care will not be jeopardized +whatever decision you and your family + + align:start position:0% +whatever decision you and your family + + + align:start position:0% +whatever decision you and your family +make possible use of your tissue sample + + align:start position:0% +make possible use of your tissue sample + + + align:start position:0% +make possible use of your tissue sample +after testing we have to understand that + + align:start position:0% +after testing we have to understand that + + + align:start position:0% +after testing we have to understand that +whether it's destroyed or kept foreign + + align:start position:0% +whether it's destroyed or kept foreign + + + align:start position:0% +whether it's destroyed or kept foreign +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +and whether it can be kept for uh dna + + align:start position:0% +and whether it can be kept for uh dna + + + align:start position:0% +and whether it can be kept for uh dna +banking all these things have to be + + align:start position:0% +banking all these things have to be + + + align:start position:0% +banking all these things have to be +discussed with the patient this is not a + + align:start position:0% +discussed with the patient this is not a + + + align:start position:0% +discussed with the patient this is not a +um + + align:start position:0% +um + + + align:start position:0% +um +five minute discussion and remember + + align:start position:0% +five minute discussion and remember + + + align:start position:0% +five minute discussion and remember +again they're typical back to our + + align:start position:0% +again they're typical back to our + + + align:start position:0% +again they're typical back to our +corporate clinic uh 512 clinics + + align:start position:0% +corporate clinic uh 512 clinics + + + align:start position:0% +corporate clinic uh 512 clinics +um + + align:start position:0% +um + + + align:start position:0% +um +our standard uh visit for a patient is + + align:start position:0% +our standard uh visit for a patient is + + + align:start position:0% +our standard uh visit for a patient is +on order 10 to 15 minutes + + align:start position:0% +on order 10 to 15 minutes + + + align:start position:0% +on order 10 to 15 minutes +and i'm telling you that this consent + + align:start position:0% +and i'm telling you that this consent + + + align:start position:0% +and i'm telling you that this consent +process requires an hour to do to do it + + align:start position:0% +process requires an hour to do to do it + + + align:start position:0% +process requires an hour to do to do it +adequately + + align:start position:0% + + + + align:start position:0% + +having said this i want to tell you + + align:start position:0% +having said this i want to tell you + + + align:start position:0% +having said this i want to tell you +we're actually performing + + align:start position:0% +we're actually performing + + + align:start position:0% +we're actually performing +routine comprehensive genetic testing on + + align:start position:0% +routine comprehensive genetic testing on + + + align:start position:0% +routine comprehensive genetic testing on +our entire population + + align:start position:0% + + + + align:start position:0% + +did you know that + + align:start position:0% + + + + align:start position:0% + +you bet + + align:start position:0% +you bet + + + align:start position:0% +you bet +so we're doing we're testing all kids + + align:start position:0% +so we're doing we're testing all kids + + + align:start position:0% +so we're doing we're testing all kids +in in the united states for uh + + align:start position:0% +in in the united states for uh + + + align:start position:0% +in in the united states for uh +genetic disease like phenylketonuria + + align:start position:0% +genetic disease like phenylketonuria + + + align:start position:0% +genetic disease like phenylketonuria +uh we're now looking for all the common + + align:start position:0% +uh we're now looking for all the common + + + align:start position:0% +uh we're now looking for all the common +polymorphisms of + + align:start position:0% +polymorphisms of + + + align:start position:0% +polymorphisms of +um + + align:start position:0% + + + + align:start position:0% + +cftr the cystic fibrosis responsible + + align:start position:0% +cftr the cystic fibrosis responsible + + + align:start position:0% +cftr the cystic fibrosis responsible +gene + + align:start position:0% +gene + + + align:start position:0% +gene +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +if you really look what the what the + + align:start position:0% +if you really look what the what the + + + align:start position:0% +if you really look what the what the +massachusetts state laboratory is doing + + align:start position:0% +massachusetts state laboratory is doing + + + align:start position:0% +massachusetts state laboratory is doing +right now in uh worcester + + align:start position:0% +right now in uh worcester + + + align:start position:0% +right now in uh worcester +they're uh with the university of + + align:start position:0% +they're uh with the university of + + + align:start position:0% +they're uh with the university of +massachusetts as i said they're in + + align:start position:0% +massachusetts as i said they're in + + + align:start position:0% +massachusetts as i said they're in +jamaica plain but they're affiliated + + align:start position:0% +jamaica plain but they're affiliated + + + align:start position:0% +jamaica plain but they're affiliated +with the university of massachusetts + + align:start position:0% +with the university of massachusetts + + + align:start position:0% +with the university of massachusetts +they're actually looking at maybe 10 20 + + align:start position:0% +they're actually looking at maybe 10 20 + + + align:start position:0% +they're actually looking at maybe 10 20 +uh diseases that they're going to do + + align:start position:0% +uh diseases that they're going to do + + + align:start position:0% +uh diseases that they're going to do +risk + + align:start position:0% +risk + + + align:start position:0% +risk +factors screening for now unlike our + + align:start position:0% +factors screening for now unlike our + + + align:start position:0% +factors screening for now unlike our +company 512 genomics they really have to + + align:start position:0% +company 512 genomics they really have to + + + align:start position:0% +company 512 genomics they really have to +do + + align:start position:0% +do + + + align:start position:0% +do +uh come come to a couple decisions about + + align:start position:0% +uh come come to a couple decisions about + + + align:start position:0% +uh come come to a couple decisions about +when to do this + + align:start position:0% +when to do this + + + align:start position:0% +when to do this +how is it determined what is routinely + + align:start position:0% +how is it determined what is routinely + + + align:start position:0% +how is it determined what is routinely +screened + + align:start position:0% +screened + + + align:start position:0% +screened +three components public health + + align:start position:0% +three components public health + + + align:start position:0% +three components public health +assessment + + align:start position:0% +assessment + + + align:start position:0% +assessment +evaluation of tests and interventions + + align:start position:0% +evaluation of tests and interventions + + + align:start position:0% +evaluation of tests and interventions +positive development and screening + + align:start position:0% +positive development and screening + + + align:start position:0% +positive development and screening +implementation the public assessment is + + align:start position:0% +implementation the public assessment is + + + align:start position:0% +implementation the public assessment is +fairly straightforward disease or + + align:start position:0% +fairly straightforward disease or + + + align:start position:0% +fairly straightforward disease or +condition should be an important public + + align:start position:0% +condition should be an important public + + + align:start position:0% +condition should be an important public +health burden not a not a rare bird and + + align:start position:0% +health burden not a not a rare bird and + + + align:start position:0% +health burden not a not a rare bird and +what is it what does that mean that + + align:start position:0% +what is it what does that mean that + + + align:start position:0% +what is it what does that mean that +means typically they like to see it + + align:start position:0% +means typically they like to see it + + + align:start position:0% +means typically they like to see it +above one and twenty thousand + + align:start position:0% +above one and twenty thousand + + + align:start position:0% +above one and twenty thousand +they won't admit to that but it's around + + align:start position:0% +they won't admit to that but it's around + + + align:start position:0% +they won't admit to that but it's around +there like thyroid disease which was one + + align:start position:0% +there like thyroid disease which was one + + + align:start position:0% +there like thyroid disease which was one +of the first things to be screened is + + align:start position:0% +of the first things to be screened is + + + align:start position:0% +of the first things to be screened is +about one in five thousand + + align:start position:0% +about one in five thousand + + + align:start position:0% +about one in five thousand +uh congenital adrenal hyperplasia which + + align:start position:0% +uh congenital adrenal hyperplasia which + + + align:start position:0% +uh congenital adrenal hyperplasia which +they do screen for now for two one + + align:start position:0% +they do screen for now for two one + + + align:start position:0% +they do screen for now for two one +hydroxide about one in twenty thousand + + align:start position:0% +hydroxide about one in twenty thousand + + + align:start position:0% +hydroxide about one in twenty thousand +the prevalence of the genetic trait okay + + align:start position:0% +the prevalence of the genetic trait okay + + + align:start position:0% +the prevalence of the genetic trait okay +has to be known the natural history the + + align:start position:0% +has to be known the natural history the + + + align:start position:0% +has to be known the natural history the +condition for susceptibility to disease + + align:start position:0% +condition for susceptibility to disease + + + align:start position:0% +condition for susceptibility to disease +to overt disease should be adequately + + align:start position:0% +to overt disease should be adequately + + + align:start position:0% +to overt disease should be adequately +understood + + align:start position:0% +understood + + + align:start position:0% +understood +and basically the safety and efficacy of + + align:start position:0% +and basically the safety and efficacy of + + + align:start position:0% +and basically the safety and efficacy of +the test blah blah has to be known now + + align:start position:0% +the test blah blah has to be known now + + + align:start position:0% +the test blah blah has to be known now +the policy issues are obviously + + align:start position:0% +the policy issues are obviously + + + align:start position:0% +the policy issues are obviously +important + + align:start position:0% +important + + + align:start position:0% +important +but the main issue is this one + + align:start position:0% + + + + align:start position:0% + +the cost of the effect this of the + + align:start position:0% +the cost of the effect this of the + + + align:start position:0% +the cost of the effect this of the +screening should be established + + align:start position:0% +screening should be established + + + align:start position:0% +screening should be established +established in other words the screening + + align:start position:0% +established in other words the screening + + + align:start position:0% +established in other words the screening +procedure whatever it is with the + + align:start position:0% +procedure whatever it is with the + + + align:start position:0% +procedure whatever it is with the +genotyping or attendant mass spec has to + + align:start position:0% +genotyping or attendant mass spec has to + + + align:start position:0% +genotyping or attendant mass spec has to +actually be within the budget of the + + align:start position:0% +actually be within the budget of the + + + align:start position:0% +actually be within the budget of the +state of massachusetts + + align:start position:0% +state of massachusetts + + + align:start position:0% +state of massachusetts +and that's why + + align:start position:0% +and that's why + + + align:start position:0% +and that's why +unlike uh 512 genomics + + align:start position:0% +unlike uh 512 genomics + + + align:start position:0% +unlike uh 512 genomics +they're absolutely allowed to make + + align:start position:0% +they're absolutely allowed to make + + + align:start position:0% +they're absolutely allowed to make +decisions like we're only going to look + + align:start position:0% +decisions like we're only going to look + + + align:start position:0% +decisions like we're only going to look +for the uh genotypes that account for 99 + + align:start position:0% +for the uh genotypes that account for 99 + + + align:start position:0% +for the uh genotypes that account for 99 +disinversion because it's a public + + align:start position:0% +disinversion because it's a public + + + align:start position:0% +disinversion because it's a public +health intervention they're not our + + align:start position:0% +health intervention they're not our + + + align:start position:0% +health intervention they're not our +doctor + + align:start position:0% +doctor + + + align:start position:0% +doctor +and that's very very different + + align:start position:0% + + + + align:start position:0% + +most of those tests were biochemical + + align:start position:0% +most of those tests were biochemical + + + align:start position:0% +most of those tests were biochemical +they're testing a genetic disease but + + align:start position:0% +they're testing a genetic disease but + + + align:start position:0% +they're testing a genetic disease but +what i'm telling you is the cystic + + align:start position:0% +what i'm telling you is the cystic + + + align:start position:0% +what i'm telling you is the cystic +fibroid this is actually old the cystic + + align:start position:0% +fibroid this is actually old the cystic + + + align:start position:0% +fibroid this is actually old the cystic +fibrosis test now is a dna test and + + align:start position:0% +fibrosis test now is a dna test and + + + align:start position:0% +fibrosis test now is a dna test and +there's they have now 20 tests that + + align:start position:0% +there's they have now 20 tests that + + + align:start position:0% +there's they have now 20 tests that +going online this is an old slide + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +in the remaining + + align:start position:0% +in the remaining + + + align:start position:0% +in the remaining +10 minutes let's role play let me tell + + align:start position:0% +10 minutes let's role play let me tell + + + align:start position:0% +10 minutes let's role play let me tell +you about a disease + + align:start position:0% +you about a disease + + + align:start position:0% +you about a disease +congenital hyperinsulinism is the most + + align:start position:0% +congenital hyperinsulinism is the most + + + align:start position:0% +congenital hyperinsulinism is the most +frequent cause of severe + + align:start position:0% +frequent cause of severe + + + align:start position:0% +frequent cause of severe +persistent hypoglycemia in newborn + + align:start position:0% +persistent hypoglycemia in newborn + + + align:start position:0% +persistent hypoglycemia in newborn +babies and children + + align:start position:0% +babies and children + + + align:start position:0% +babies and children +in most countries it occurs in + + align:start position:0% +in most countries it occurs in + + + align:start position:0% +in most countries it occurs in +approximately one in twenty five + + align:start position:0% +approximately one in twenty five + + + align:start position:0% +approximately one in twenty five +thousand to one in fifty thousand births + + align:start position:0% +thousand to one in fifty thousand births + + + align:start position:0% +thousand to one in fifty thousand births +about sixty percent of babies with + + align:start position:0% +about sixty percent of babies with + + + align:start position:0% +about sixty percent of babies with +hyperinsulinism develop hypoglycemia + + align:start position:0% +hyperinsulinism develop hypoglycemia + + + align:start position:0% +hyperinsulinism develop hypoglycemia +during their first month of life their + + align:start position:0% +during their first month of life their + + + align:start position:0% +during their first month of life their +blood sugar crashes + + align:start position:0% +blood sugar crashes + + + align:start position:0% +blood sugar crashes +an additional 30 will be diagnosed later + + align:start position:0% +an additional 30 will be diagnosed later + + + align:start position:0% +an additional 30 will be diagnosed later +in the first year and the main draft of + + align:start position:0% +in the first year and the main draft of + + + align:start position:0% +in the first year and the main draft of +that so 90 of them are + + align:start position:0% +that so 90 of them are + + + align:start position:0% +that so 90 of them are +diagnosed in the first year + + align:start position:0% +diagnosed in the first year + + + align:start position:0% +diagnosed in the first year +60 in the first month with early + + align:start position:0% +60 in the first month with early + + + align:start position:0% +60 in the first month with early +treatment and aggressive prevention of + + align:start position:0% +treatment and aggressive prevention of + + + align:start position:0% +treatment and aggressive prevention of +hypoglycemia brain damage can be + + align:start position:0% +hypoglycemia brain damage can be + + + align:start position:0% +hypoglycemia brain damage can be +prevented the brain damages from having + + align:start position:0% +prevented the brain damages from having + + + align:start position:0% +prevented the brain damages from having +sustained low blood sugar + + align:start position:0% +sustained low blood sugar + + + align:start position:0% +sustained low blood sugar +which is actually not harmful when + + align:start position:0% +which is actually not harmful when + + + align:start position:0% +which is actually not harmful when +you're adult and your brain is um stable + + align:start position:0% +you're adult and your brain is um stable + + + align:start position:0% +you're adult and your brain is um stable +but when you have a developing brain + + align:start position:0% +but when you have a developing brain + + + align:start position:0% +but when you have a developing brain +and it's not uh getting a lot of glucose + + align:start position:0% +and it's not uh getting a lot of glucose + + + align:start position:0% +and it's not uh getting a lot of glucose +and therefore metabolism for periods of + + align:start position:0% +and therefore metabolism for periods of + + + align:start position:0% +and therefore metabolism for periods of +time + + align:start position:0% +time + + + align:start position:0% +time +especially repeatedly you can really + + align:start position:0% +especially repeatedly you can really + + + align:start position:0% +especially repeatedly you can really +have brain damage however brain damage + + align:start position:0% +have brain damage however brain damage + + + align:start position:0% +have brain damage however brain damage +can occur in up to 50 children + + align:start position:0% +can occur in up to 50 children + + + align:start position:0% +can occur in up to 50 children +hyperinsulinism if their condition is + + align:start position:0% +hyperinsulinism if their condition is + + + align:start position:0% +hyperinsulinism if their condition is +not recognized or if treatment is + + align:start position:0% +not recognized or if treatment is + + + align:start position:0% +not recognized or if treatment is +ineffective in the prevention of + + align:start position:0% +ineffective in the prevention of + + + align:start position:0% +ineffective in the prevention of +hypoglycemia + + align:start position:0% + + + + align:start position:0% + +on the other hand so remember this + + align:start position:0% +on the other hand so remember this + + + align:start position:0% +on the other hand so remember this +it's a 125 125 000 150 000 on the other + + align:start position:0% +it's a 125 125 000 150 000 on the other + + + align:start position:0% +it's a 125 125 000 150 000 on the other +hand neonatal hypoglycemia so + + align:start position:0% +hand neonatal hypoglycemia so + + + align:start position:0% +hand neonatal hypoglycemia so +hypoglycemia in these newborn kids has + + align:start position:0% +hypoglycemia in these newborn kids has + + + align:start position:0% +hypoglycemia in these newborn kids has +an incidence of two to five per 1000 + + align:start position:0% +an incidence of two to five per 1000 + + + align:start position:0% +an incidence of two to five per 1000 +there's a zillion reasons why kids um + + align:start position:0% +there's a zillion reasons why kids um + + + align:start position:0% +there's a zillion reasons why kids um +have hypoglycemia from being slightly + + align:start position:0% +have hypoglycemia from being slightly + + + align:start position:0% +have hypoglycemia from being slightly +immature birth + + align:start position:0% +immature birth + + + align:start position:0% +immature birth +uh to the iv was switched off too fast + + align:start position:0% +uh to the iv was switched off too fast + + + align:start position:0% +uh to the iv was switched off too fast +and so all of a sudden the pancreas + + align:start position:0% +and so all of a sudden the pancreas + + + align:start position:0% +and so all of a sudden the pancreas +didn't have + + align:start position:0% +didn't have + + + align:start position:0% +didn't have +enough minutes to wake up and switch off + + align:start position:0% +enough minutes to wake up and switch off + + + align:start position:0% +enough minutes to wake up and switch off +the + + align:start position:0% +the + + + align:start position:0% +the +insulin + + align:start position:0% +insulin + + + align:start position:0% +insulin +um + + align:start position:0% +um + + + align:start position:0% +um +that + + align:start position:0% +that + + + align:start position:0% +that +they're having an infection and so on + + align:start position:0% +they're having an infection and so on + + + align:start position:0% +they're having an infection and so on +so + + align:start position:0% +so + + + align:start position:0% +so +the state of our knowledge in 1992 + + align:start position:0% +the state of our knowledge in 1992 + + + align:start position:0% +the state of our knowledge in 1992 +when i was finishing my pediatric + + align:start position:0% +when i was finishing my pediatric + + + align:start position:0% +when i was finishing my pediatric +increment residency was there was a + + align:start position:0% +increment residency was there was a + + + align:start position:0% +increment residency was there was a +disease that there was this disease + + align:start position:0% +disease that there was this disease + + + align:start position:0% +disease that there was this disease +called nicodeoblastosis + + align:start position:0% +called nicodeoblastosis + + + align:start position:0% +called nicodeoblastosis +or hyperplasia of the pancreatic islet + + align:start position:0% +or hyperplasia of the pancreatic islet + + + align:start position:0% +or hyperplasia of the pancreatic islet +cells the cells that produce insulin and + + align:start position:0% +cells the cells that produce insulin and + + + align:start position:0% +cells the cells that produce insulin and +for reasons that we didn't know + + align:start position:0% +for reasons that we didn't know + + + align:start position:0% +for reasons that we didn't know +either the entire pancreas or + + align:start position:0% +either the entire pancreas or + + + align:start position:0% +either the entire pancreas or +spots and pancreas were hyper-producing + + align:start position:0% +spots and pancreas were hyper-producing + + + align:start position:0% +spots and pancreas were hyper-producing +insulin + + align:start position:0% +insulin + + + align:start position:0% +insulin +and + + align:start position:0% +and + + + align:start position:0% +and +we if we didn't uh + + align:start position:0% +we if we didn't uh + + + align:start position:0% +we if we didn't uh +treated pro and some percentages kids + + align:start position:0% +treated pro and some percentages kids + + + align:start position:0% +treated pro and some percentages kids +would go on to be medically manageable + + align:start position:0% + + + + align:start position:0% + +but a whole bunch of them were not and + + align:start position:0% +but a whole bunch of them were not and + + + align:start position:0% +but a whole bunch of them were not and +would have to take out their whole + + align:start position:0% +would have to take out their whole + + + align:start position:0% +would have to take out their whole +pancreas + + align:start position:0% +pancreas + + + align:start position:0% +pancreas +and sometimes we saw that we shouldn't + + align:start position:0% +and sometimes we saw that we shouldn't + + + align:start position:0% +and sometimes we saw that we shouldn't +we didn't need to take out the pancreas + + align:start position:0% +we didn't need to take out the pancreas + + + align:start position:0% +we didn't need to take out the pancreas +that they were just + + align:start position:0% +that they were just + + + align:start position:0% +that they were just +focal pieces of pancreas that involved + + align:start position:0% +focal pieces of pancreas that involved + + + align:start position:0% +focal pieces of pancreas that involved +we could have left them more because by + + align:start position:0% +we could have left them more because by + + + align:start position:0% +we could have left them more because by +taking the whole pancreas out + + align:start position:0% +taking the whole pancreas out + + + align:start position:0% +taking the whole pancreas out +we made them a + + align:start position:0% +we made them a + + + align:start position:0% +we made them a +diabetic + + align:start position:0% +diabetic + + + align:start position:0% +diabetic +b + + align:start position:0% +b + + + align:start position:0% +b +with insufficiency of those enzymes that + + align:start position:0% +with insufficiency of those enzymes that + + + align:start position:0% +with insufficiency of those enzymes that +used to dissolve your foods + + align:start position:0% +used to dissolve your foods + + + align:start position:0% +used to dissolve your foods +it was really not a pretty sight plus we + + align:start position:0% +it was really not a pretty sight plus we + + + align:start position:0% +it was really not a pretty sight plus we +kept them in the hospital for weeks to + + align:start position:0% +kept them in the hospital for weeks to + + + align:start position:0% +kept them in the hospital for weeks to +diagnose them that was the state of art + + align:start position:0% +diagnose them that was the state of art + + + align:start position:0% +diagnose them that was the state of art +when i was a fellow + + align:start position:0% +when i was a fellow + + + align:start position:0% +when i was a fellow +so here's the state of our knowledge in + + align:start position:0% +so here's the state of our knowledge in + + + align:start position:0% +so here's the state of our knowledge in + + align:start position:0% + + + align:start position:0% +there's something called a potassium + + align:start position:0% +there's something called a potassium + + + align:start position:0% +there's something called a potassium +channel of which there are many which + + align:start position:0% +channel of which there are many which + + + align:start position:0% +channel of which there are many which +controls insulin released in the islet + + align:start position:0% +controls insulin released in the islet + + + align:start position:0% +controls insulin released in the islet +cells + + align:start position:0% +cells + + + align:start position:0% +cells +basically there are these two uh + + align:start position:0% +basically there are these two uh + + + align:start position:0% +basically there are these two uh +proteins su r and um + + align:start position:0% +proteins su r and um + + + align:start position:0% +proteins su r and um +cure 6.2 + + align:start position:0% +cure 6.2 + + + align:start position:0% +cure 6.2 +which actually + + align:start position:0% +which actually + + + align:start position:0% +which actually +gate + + align:start position:0% +gate + + + align:start position:0% +gate +the flow + + align:start position:0% +the flow + + + align:start position:0% +the flow +of potassium + + align:start position:0% +of potassium + + + align:start position:0% +of potassium +the rest of the channel determines the + + align:start position:0% +the rest of the channel determines the + + + align:start position:0% +the rest of the channel determines the +resting membrane potential which is + + align:start position:0% +resting membrane potential which is + + + align:start position:0% +resting membrane potential which is +maintained at the necessary voltage to + + align:start position:0% +maintained at the necessary voltage to + + + align:start position:0% +maintained at the necessary voltage to +keep voltage dependent calcium channels + + align:start position:0% +keep voltage dependent calcium channels + + + align:start position:0% +keep voltage dependent calcium channels +closing cell that does not secrete when + + align:start position:0% +closing cell that does not secrete when + + + align:start position:0% +closing cell that does not secrete when +glucose comes into the cell and there's + + align:start position:0% +glucose comes into the cell and there's + + + align:start position:0% +glucose comes into the cell and there's +a resulting change in the ratio of atp + + align:start position:0% +a resulting change in the ratio of atp + + + align:start position:0% +a resulting change in the ratio of atp +from uh to adp because of metabolism k + + align:start position:0% +from uh to adp because of metabolism k + + + align:start position:0% +from uh to adp because of metabolism k +channels close and the membrane + + align:start position:0% +channels close and the membrane + + + align:start position:0% +channels close and the membrane +depolarizes + + align:start position:0% +depolarizes + + + align:start position:0% +depolarizes +subsequently voltage gates voltage-gated + + align:start position:0% +subsequently voltage gates voltage-gated + + + align:start position:0% +subsequently voltage gates voltage-gated +calcium channels are open initiating the + + align:start position:0% +calcium channels are open initiating the + + + align:start position:0% +calcium channels are open initiating the +insulin secretory cascade therefore the + + align:start position:0% +insulin secretory cascade therefore the + + + align:start position:0% +insulin secretory cascade therefore the +k-channel function the potassium channel + + align:start position:0% +k-channel function the potassium channel + + + align:start position:0% +k-channel function the potassium channel +functions are linked to the metabolic + + align:start position:0% +functions are linked to the metabolic + + + align:start position:0% +functions are linked to the metabolic +state of the cell + + align:start position:0% +state of the cell + + + align:start position:0% +state of the cell +and the electrical activity of the + + align:start position:0% +and the electrical activity of the + + + align:start position:0% +and the electrical activity of the +membrane resulting in the stimulation or + + align:start position:0% +membrane resulting in the stimulation or + + + align:start position:0% +membrane resulting in the stimulation or +inhibition of insulin release so we have + + align:start position:0% +inhibition of insulin release so we have + + + align:start position:0% +inhibition of insulin release so we have +a thermostat a rheostat which says + + align:start position:0% +a thermostat a rheostat which says + + + align:start position:0% +a thermostat a rheostat which says +center the more ins the more glucose i + + align:start position:0% +center the more ins the more glucose i + + + align:start position:0% +center the more ins the more glucose i +see + + align:start position:0% +see + + + align:start position:0% +see +the more i'm going to + + align:start position:0% +the more i'm going to + + + align:start position:0% +the more i'm going to +release calcium and therefore + + align:start position:0% +release calcium and therefore + + + align:start position:0% +release calcium and therefore +insulin into the blood + + align:start position:0% +insulin into the blood + + + align:start position:0% +insulin into the blood +so if that's the + + align:start position:0% +so if that's the + + + align:start position:0% +so if that's the +basic rheostat and + + align:start position:0% + + + + align:start position:0% + +we know that these two genes which + + align:start position:0% +we know that these two genes which + + + align:start position:0% +we know that these two genes which +actually happen to be next to each other + + align:start position:0% +actually happen to be next to each other + + + align:start position:0% +actually happen to be next to each other +on chromosome 11 + + align:start position:0% +on chromosome 11 + + + align:start position:0% +on chromosome 11 +if you have mutations of them instead of + + align:start position:0% +if you have mutations of them instead of + + + align:start position:0% +if you have mutations of them instead of +coming nicely together in this um + + align:start position:0% +coming nicely together in this um + + + align:start position:0% +coming nicely together in this um +octamer they come in these various + + align:start position:0% +octamer they come in these various + + + align:start position:0% +octamer they come in these various +dysfunctional or poorly functional uh + + align:start position:0% +dysfunctional or poorly functional uh + + + align:start position:0% +dysfunctional or poorly functional uh +heterodimers or or homo + + align:start position:0% +heterodimers or or homo + + + align:start position:0% +heterodimers or or homo +homo homo octamers + + align:start position:0% +homo homo octamers + + + align:start position:0% +homo homo octamers +they just come together in the wrong way + + align:start position:0% +they just come together in the wrong way + + + align:start position:0% +they just come together in the wrong way +and they don't work right + + align:start position:0% +and they don't work right + + + align:start position:0% +and they don't work right +and + + align:start position:0% +and + + + align:start position:0% +and +it turns out there's a lot of mutations + + align:start position:0% +it turns out there's a lot of mutations + + + align:start position:0% +it turns out there's a lot of mutations +in s-u-r one of those genes that in this + + align:start position:0% +in s-u-r one of those genes that in this + + + align:start position:0% +in s-u-r one of those genes that in this +in the + + align:start position:0% +in the + + + align:start position:0% +in the +uh cure uh one six point two there's + + align:start position:0% +uh cure uh one six point two there's + + + align:start position:0% +uh cure uh one six point two there's +only three no mutations but this + + align:start position:0% +only three no mutations but this + + + align:start position:0% +only three no mutations but this +looks like maybe uh 30 40 mutations in + + align:start position:0% +looks like maybe uh 30 40 mutations in + + + align:start position:0% +looks like maybe uh 30 40 mutations in +in surr + + align:start position:0% +in surr + + + align:start position:0% +in surr +some of them are common they're hot + + align:start position:0% +some of them are common they're hot + + + align:start position:0% +some of them are common they're hot +spots a lot of different families have + + align:start position:0% +spots a lot of different families have + + + align:start position:0% +spots a lot of different families have +them some of them are one of a kind some + + align:start position:0% +them some of them are one of a kind some + + + align:start position:0% +them some of them are one of a kind some +of them are in the coding regions these + + align:start position:0% +of them are in the coding regions these + + + align:start position:0% +of them are in the coding regions these +are the 39 um exons of su r and by the + + align:start position:0% +are the 39 um exons of su r and by the + + + align:start position:0% +are the 39 um exons of su r and by the +way that's really going to cost us in + + align:start position:0% +way that's really going to cost us in + + + align:start position:0% +way that's really going to cost us in +our 512 genomics uh + + align:start position:0% +our 512 genomics uh + + + align:start position:0% +our 512 genomics uh +company to sequence all of those + + align:start position:0% +company to sequence all of those + + + align:start position:0% +company to sequence all of those +and + + align:start position:0% +and + + + align:start position:0% +and +uh some of them are in introns they're + + align:start position:0% +uh some of them are in introns they're + + + align:start position:0% +uh some of them are in introns they're +at the + + align:start position:0% +at the + + + align:start position:0% +at the +um the splice junction they're just + + align:start position:0% +um the splice junction they're just + + + align:start position:0% +um the splice junction they're just +right inside just right um across the + + align:start position:0% +right inside just right um across the + + + align:start position:0% +right inside just right um across the +intron exon boundary into the part of + + align:start position:0% +intron exon boundary into the part of + + + align:start position:0% +intron exon boundary into the part of +the intron which is the donor or splice + + align:start position:0% +the intron which is the donor or splice + + + align:start position:0% +the intron which is the donor or splice +acceptor site which determines when + + align:start position:0% +acceptor site which determines when + + + align:start position:0% +acceptor site which determines when +you're going to splice or not and these + + align:start position:0% +you're going to splice or not and these + + + align:start position:0% +you're going to splice or not and these +all are known + + align:start position:0% +all are known + + + align:start position:0% +all are known +highly penetrate causes + + align:start position:0% +highly penetrate causes + + + align:start position:0% +highly penetrate causes +of disease + + align:start position:0% +of disease + + + align:start position:0% +of disease +they're autosomal recessive + + align:start position:0% +they're autosomal recessive + + + align:start position:0% +they're autosomal recessive +they're also more recessive but + + align:start position:0% +they're also more recessive but + + + align:start position:0% +they're also more recessive but +if you look at + + align:start position:0% +if you look at + + + align:start position:0% +if you look at +um these two um + + align:start position:0% +um these two um + + + align:start position:0% +um these two um +forms of hyperinsulinism so that if you + + align:start position:0% +forms of hyperinsulinism so that if you + + + align:start position:0% +forms of hyperinsulinism so that if you +look at the slide there's a two patients + + align:start position:0% +look at the slide there's a two patients + + + align:start position:0% +look at the slide there's a two patients +that have the two different uh + + align:start position:0% +that have the two different uh + + + align:start position:0% +that have the two different uh +presentations i told you about one has + + align:start position:0% +presentations i told you about one has + + + align:start position:0% +presentations i told you about one has +these + + align:start position:0% +these + + + align:start position:0% +these +uh focal lab + + align:start position:0% +uh focal lab + + + align:start position:0% +uh focal lab +focal hyperplasia which pushes aside the + + align:start position:0% +focal hyperplasia which pushes aside the + + + align:start position:0% +focal hyperplasia which pushes aside the +normal tissue and the other where it's + + align:start position:0% +normal tissue and the other where it's + + + align:start position:0% +normal tissue and the other where it's +diffused throughout the tissue + + align:start position:0% +diffused throughout the tissue + + + align:start position:0% +diffused throughout the tissue +and turns out we now know why that is + + align:start position:0% +and turns out we now know why that is + + + align:start position:0% +and turns out we now know why that is +it turns out that there is in the in the + + align:start position:0% +it turns out that there is in the in the + + + align:start position:0% +it turns out that there is in the in the +diffuse form it's germline transmission + + align:start position:0% +diffuse form it's germline transmission + + + align:start position:0% +diffuse form it's germline transmission +of the + + align:start position:0% +of the + + + align:start position:0% +of the +homozygous state + + align:start position:0% +homozygous state + + + align:start position:0% +homozygous state +and the focal state what's happening is + + align:start position:0% +and the focal state what's happening is + + + align:start position:0% +and the focal state what's happening is +there's loss of heterozygosity + + align:start position:0% +there's loss of heterozygosity + + + align:start position:0% +there's loss of heterozygosity +so that you have in a parental gene + + align:start position:0% +so that you have in a parental gene + + + align:start position:0% +so that you have in a parental gene +i think actually specifically a paternal + + align:start position:0% +i think actually specifically a paternal + + + align:start position:0% +i think actually specifically a paternal +gene and there's lots of heterozygotes + + align:start position:0% +gene and there's lots of heterozygotes + + + align:start position:0% +gene and there's lots of heterozygotes +of the loss of the maternal allele and + + align:start position:0% +of the loss of the maternal allele and + + + align:start position:0% +of the loss of the maternal allele and +so those + + align:start position:0% +so those + + + align:start position:0% +so those +um + + align:start position:0% +um + + + align:start position:0% +um +cells where the loss of maternal allele + + align:start position:0% +cells where the loss of maternal allele + + + align:start position:0% +cells where the loss of maternal allele +you get focal hyperplasia + + align:start position:0% +you get focal hyperplasia + + + align:start position:0% +you get focal hyperplasia +due to the um the poor functioning of + + align:start position:0% +due to the um the poor functioning of + + + align:start position:0% +due to the um the poor functioning of +that + + align:start position:0% +that + + + align:start position:0% +that +channel + + align:start position:0% + + + + align:start position:0% + +so i told you about this disease and in + + align:start position:0% +so i told you about this disease and in + + + align:start position:0% +so i told you about this disease and in +the last five remaining minutes would + + align:start position:0% +the last five remaining minutes would + + + align:start position:0% +the last five remaining minutes would +you order a genetic test + + align:start position:0% +you order a genetic test + + + align:start position:0% +you order a genetic test +how about hypoglycemia in the newborn + + align:start position:0% +how about hypoglycemia in the newborn + + + align:start position:0% +how about hypoglycemia in the newborn +baby + + align:start position:0% +baby + + + align:start position:0% +baby +jose says no + + align:start position:0% + + + + align:start position:0% + +two doctor512 are you gonna order this + + align:start position:0% +two doctor512 are you gonna order this + + + align:start position:0% +two doctor512 are you gonna order this +test or not + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% +oh + + + align:start position:0% +oh +at least he's playing like a doctor + + align:start position:0% +at least he's playing like a doctor + + + align:start position:0% +at least he's playing like a doctor +because he's actually making a decision + + align:start position:0% +because he's actually making a decision + + + align:start position:0% +because he's actually making a decision +because we have a patient we need a + + align:start position:0% +because we have a patient we need a + + + align:start position:0% +because we have a patient we need a +decision + + align:start position:0% +decision + + + align:start position:0% +decision +what + + align:start position:0% +what + + + align:start position:0% +what +two it's i think i said two to five + + align:start position:0% +two it's i think i said two to five + + + align:start position:0% +two it's i think i said two to five +thousand of routine hypoglycemia i think + + align:start position:0% +thousand of routine hypoglycemia i think + + + align:start position:0% +thousand of routine hypoglycemia i think +i said one in twenty five thousand uh + + align:start position:0% +i said one in twenty five thousand uh + + + align:start position:0% +i said one in twenty five thousand uh +for um persistent hyperinsulinemia + + align:start position:0% + + + + align:start position:0% + +yes no what do we do + + align:start position:0% +yes no what do we do + + + align:start position:0% +yes no what do we do +dr wolf + + align:start position:0% + + + + align:start position:0% + +yes so there are people like you who do + + align:start position:0% +yes so there are people like you who do + + + align:start position:0% +yes so there are people like you who do +it but thankfully we don't give them the + + align:start position:0% +it but thankfully we don't give them the + + + align:start position:0% +it but thankfully we don't give them the +opportunity because uh + + align:start position:0% +opportunity because uh + + + align:start position:0% +opportunity because uh +because + + align:start position:0% +because + + + align:start position:0% +because +because because because 512 genomics + + align:start position:0% +because because because 512 genomics + + + align:start position:0% +because because because 512 genomics +would be incredibly happy with you + + align:start position:0% +would be incredibly happy with you + + + align:start position:0% +would be incredibly happy with you +because we'd be making a mint but + + align:start position:0% +because we'd be making a mint but + + + align:start position:0% +because we'd be making a mint but +probably you want to look for more signs + + align:start position:0% +probably you want to look for more signs + + + align:start position:0% +probably you want to look for more signs +and symptoms to to make you think that + + align:start position:0% +and symptoms to to make you think that + + + align:start position:0% +and symptoms to to make you think that +this is happening + + align:start position:0% +this is happening + + + align:start position:0% +this is happening +um oh this sucks + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +my take on it would be if there's a + + align:start position:0% +my take on it would be if there's a + + + align:start position:0% +my take on it would be if there's a +persistent + + align:start position:0% +persistent + + + align:start position:0% +persistent +drop in glucose if the iv runs um + + align:start position:0% +drop in glucose if the iv runs um + + + align:start position:0% +drop in glucose if the iv runs um +i should say uh less yeah less than + + align:start position:0% +i should say uh less yeah less than + + + align:start position:0% +i should say uh less yeah less than +twice the basal means let me give you + + align:start position:0% +twice the basal means let me give you + + + align:start position:0% +twice the basal means let me give you +the full scenario you have a kid that + + align:start position:0% +the full scenario you have a kid that + + + align:start position:0% +the full scenario you have a kid that +you're maintaining blood sugar by + + align:start position:0% +you're maintaining blood sugar by + + + align:start position:0% +you're maintaining blood sugar by +getting twice the normal amount of + + align:start position:0% +getting twice the normal amount of + + + align:start position:0% +getting twice the normal amount of +glucose + + align:start position:0% +glucose + + + align:start position:0% +glucose +and every time you try to + + align:start position:0% +and every time you try to + + + align:start position:0% +and every time you try to +pull it down the + + align:start position:0% +pull it down the + + + align:start position:0% +pull it down the +kid gets hypoglycemic and it doesn't + + align:start position:0% +kid gets hypoglycemic and it doesn't + + + align:start position:0% +kid gets hypoglycemic and it doesn't +happen once it happens many times over + + align:start position:0% +happen once it happens many times over + + + align:start position:0% +happen once it happens many times over +the first few days + + align:start position:0% +the first few days + + + align:start position:0% +the first few days +and so basically convince yourself that + + align:start position:0% +and so basically convince yourself that + + + align:start position:0% +and so basically convince yourself that +there's something wrong so give yourself + + align:start position:0% +there's something wrong so give yourself + + + align:start position:0% +there's something wrong so give yourself +two or three days to really convince + + align:start position:0% +two or three days to really convince + + + align:start position:0% +two or three days to really convince +yourself that something wrong + + align:start position:0% +yourself that something wrong + + + align:start position:0% +yourself that something wrong +and when you do that + + align:start position:0% +and when you do that + + + align:start position:0% +and when you do that +well + + align:start position:0% +well + + + align:start position:0% +well +i'm just telling you by experience + + align:start position:0% +i'm just telling you by experience + + + align:start position:0% +i'm just telling you by experience +probably you want to do that within the + + align:start position:0% +probably you want to do that within the + + + align:start position:0% +probably you want to do that within the +first week so what would you order + + align:start position:0% + + + + align:start position:0% + +i mean by the way don't feel bad about + + align:start position:0% +i mean by the way don't feel bad about + + + align:start position:0% +i mean by the way don't feel bad about +this if i ask this to any group of + + align:start position:0% +this if i ask this to any group of + + + align:start position:0% +this if i ask this to any group of +medical students or endocrine fellows + + align:start position:0% +medical students or endocrine fellows + + + align:start position:0% +medical students or endocrine fellows +they would not know the answer + + align:start position:0% +they would not know the answer + + + align:start position:0% +they would not know the answer +which gene + + align:start position:0% + + + + align:start position:0% + +both okay + + align:start position:0% +both okay + + + align:start position:0% +both okay +right + + align:start position:0% +right + + + align:start position:0% +right +what's part of the gene + + align:start position:0% + + + + align:start position:0% + +remember our picture of sur i thought we + + align:start position:0% +remember our picture of sur i thought we + + + align:start position:0% +remember our picture of sur i thought we +saw things everywhere right yeah + + align:start position:0% + + + + align:start position:0% + +from what sample + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +you could and eventually if you know + + align:start position:0% +you could and eventually if you know + + + align:start position:0% +you could and eventually if you know +three months out if we have no better + + align:start position:0% +three months out if we have no better + + + align:start position:0% +three months out if we have no better +story but you know parents are gonna + + align:start position:0% +story but you know parents are gonna + + + align:start position:0% +story but you know parents are gonna +come wailing on you say + + align:start position:0% +come wailing on you say + + + align:start position:0% +come wailing on you say +presumably + + align:start position:0% +presumably + + + align:start position:0% +presumably +no but maybe it's not + + align:start position:0% +no but maybe it's not + + + align:start position:0% +no but maybe it's not +so i mean i'm telling you that there's a + + align:start position:0% +so i mean i'm telling you that there's a + + + align:start position:0% +so i mean i'm telling you that there's a +certain group so but you have these pins + + align:start position:0% +certain group so but you have these pins + + + align:start position:0% +certain group so but you have these pins +apparent these parents are wailing on + + align:start position:0% +apparent these parents are wailing on + + + align:start position:0% +apparent these parents are wailing on +you + + align:start position:0% +you + + + align:start position:0% +you +and they're saying and they're not and + + align:start position:0% +and they're saying and they're not and + + + align:start position:0% +and they're saying and they're not and +you're saying three months i'll say i + + align:start position:0% +you're saying three months i'll say i + + + align:start position:0% +you're saying three months i'll say i +thought i came to harvard um don't you + + align:start position:0% +thought i came to harvard um don't you + + + align:start position:0% +thought i came to harvard um don't you +guys don't have genetic testing so what + + align:start position:0% +guys don't have genetic testing so what + + + align:start position:0% +guys don't have genetic testing so what +are you going to do + + align:start position:0% + + + + align:start position:0% + +so here's what i would do + + align:start position:0% +so here's what i would do + + + align:start position:0% +so here's what i would do +um + + align:start position:0% +um + + + align:start position:0% +um +if we ever come certainly to + + align:start position:0% +if we ever come certainly to + + + align:start position:0% +if we ever come certainly to +pancreatic removal which we will have to + + align:start position:0% +pancreatic removal which we will have to + + + align:start position:0% +pancreatic removal which we will have to +in some cases definitely won't want to + + align:start position:0% +in some cases definitely won't want to + + + align:start position:0% +in some cases definitely won't want to +look at the mutation tissue but what + + align:start position:0% +look at the mutation tissue but what + + + align:start position:0% +look at the mutation tissue but what +i'll do is i'll actually look at the p + + align:start position:0% +i'll do is i'll actually look at the p + + + align:start position:0% +i'll do is i'll actually look at the p +the parents and see if the father mother + + align:start position:0% +the parents and see if the father mother + + + align:start position:0% +the parents and see if the father mother +also have uh + + align:start position:0% +also have uh + + + align:start position:0% +also have uh +the mutation so if the father + + align:start position:0% +the mutation so if the father + + + align:start position:0% +the mutation so if the father +for instance has the mutation + + align:start position:0% +for instance has the mutation + + + align:start position:0% +for instance has the mutation +in one gene is if he's heterozygous for + + align:start position:0% +in one gene is if he's heterozygous for + + + align:start position:0% +in one gene is if he's heterozygous for +the mutation + + align:start position:0% +the mutation + + + align:start position:0% +the mutation +um i'm gonna have a very high index of + + align:start position:0% +um i'm gonna have a very high index of + + + align:start position:0% +um i'm gonna have a very high index of +suspicion + + align:start position:0% +suspicion + + + align:start position:0% +suspicion +uh the baby is homozygous obviously so i + + align:start position:0% +uh the baby is homozygous obviously so i + + + align:start position:0% +uh the baby is homozygous obviously so i +look at baby blood and look at + + align:start position:0% +look at baby blood and look at + + + align:start position:0% +look at baby blood and look at +dad blood + + align:start position:0% +dad blood + + + align:start position:0% +dad blood +and this is what i'll do + + align:start position:0% +and this is what i'll do + + + align:start position:0% +and this is what i'll do +but i'm pointing out it's not obvious + + align:start position:0% +but i'm pointing out it's not obvious + + + align:start position:0% +but i'm pointing out it's not obvious +and every story is slightly different + + align:start position:0% +and every story is slightly different + + + align:start position:0% +and every story is slightly different +that's why this whole area of genomic + + align:start position:0% +that's why this whole area of genomic + + + align:start position:0% +that's why this whole area of genomic +medicine + + align:start position:0% +medicine + + + align:start position:0% +medicine +is incredibly fraught with a knowledge + + align:start position:0% +is incredibly fraught with a knowledge + + + align:start position:0% +is incredibly fraught with a knowledge +management problem + + align:start position:0% +management problem + + + align:start position:0% +management problem +um + + align:start position:0% +um + + + align:start position:0% +um +[Music] + + align:start position:0% + + + + align:start position:0% + +no no + + align:start position:0% +no no + + + align:start position:0% +no no +since + + align:start position:0% +since + + + align:start position:0% +since +in this particular example + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um + + align:start position:0% + + + + align:start position:0% + +some of your + + align:start position:0% +some of your + + + align:start position:0% +some of your +extracts + + align:start position:0% +extracts + + + align:start position:0% +extracts +like build up a cdna + + align:start position:0% +like build up a cdna + + + align:start position:0% +like build up a cdna +thing and just basically test to see + + align:start position:0% +thing and just basically test to see + + + align:start position:0% +thing and just basically test to see +what's wrong with that + + align:start position:0% +what's wrong with that + + + align:start position:0% +what's wrong with that +okay let's go to this are we looking + + align:start position:0% +okay let's go to this are we looking + + + align:start position:0% +okay let's go to this are we looking +expression or are we looking at dna + + align:start position:0% +expression or are we looking at dna + + + align:start position:0% +expression or are we looking at dna +well we'd be looking at expression + + align:start position:0% +well we'd be looking at expression + + + align:start position:0% +well we'd be looking at expression +so those were those were a point those + + align:start position:0% +so those were those were a point those + + + align:start position:0% +so those were those were a point those +are point mutations those are point + + align:start position:0% +are point mutations those are point + + + align:start position:0% +are point mutations those are point +mutations some of them were deletions + + align:start position:0% +mutations some of them were deletions + + + align:start position:0% +mutations some of them were deletions +some of them were deletions but most of + + align:start position:0% +some of them were deletions but most of + + + align:start position:0% +some of them were deletions but most of +them in fact everyone i showed it was a + + align:start position:0% +them in fact everyone i showed it was a + + + align:start position:0% +them in fact everyone i showed it was a +micro deletion three or four bases gone + + align:start position:0% +micro deletion three or four bases gone + + + align:start position:0% +micro deletion three or four bases gone +every array i looked at that i showed + + align:start position:0% +every array i looked at that i showed + + + align:start position:0% +every array i looked at that i showed +you would would actually still say the + + align:start position:0% +you would would actually still say the + + + align:start position:0% +you would would actually still say the +gene was present + + align:start position:0% + + + + align:start position:0% + +right but if it was in one of the + + align:start position:0% +right but if it was in one of the + + + align:start position:0% +right but if it was in one of the +informs + + align:start position:0% + + + + align:start position:0% + +no you just say that just changes the + + align:start position:0% +no you just say that just changes the + + + align:start position:0% +no you just say that just changes the +splicing + + align:start position:0% +splicing + + + align:start position:0% +splicing +or it'll cause early termination of the + + align:start position:0% +or it'll cause early termination of the + + + align:start position:0% +or it'll cause early termination of the +gene product + + align:start position:0% +gene product + + + align:start position:0% +gene product +but you still have + + align:start position:0% +but you still have + + + align:start position:0% +but you still have +if let's say for the sake of argument + + align:start position:0% +if let's say for the sake of argument + + + align:start position:0% +if let's say for the sake of argument +let's go back + + align:start position:0% + + + + align:start position:0% + +yeah so for instance let's say that + + align:start position:0% +yeah so for instance let's say that + + + align:start position:0% +yeah so for instance let's say that +it's here + + align:start position:0% +it's here + + + align:start position:0% +it's here +so + + align:start position:0% +so + + + align:start position:0% +so +and let's say that the fact that you + + align:start position:0% +and let's say that the fact that you + + + align:start position:0% +and let's say that the fact that you +have the that this + + align:start position:0% +have the that this + + + align:start position:0% +have the that this +you're missing this g goes a that you + + align:start position:0% +you're missing this g goes a that you + + + align:start position:0% +you're missing this g goes a that you +don't in fact have the splice correctly + + align:start position:0% +don't in fact have the splice correctly + + + align:start position:0% +don't in fact have the splice correctly +and that leads to continued um + + align:start position:0% +and that leads to continued um + + + align:start position:0% +and that leads to continued um +translation of the intron as an exon + + align:start position:0% +translation of the intron as an exon + + + align:start position:0% +translation of the intron as an exon +and therefore since it's mumbo jumbo it + + align:start position:0% +and therefore since it's mumbo jumbo it + + + align:start position:0% +and therefore since it's mumbo jumbo it +causes premature termination you still + + align:start position:0% +causes premature termination you still + + + align:start position:0% +causes premature termination you still +have 90 percent of the gene there + + align:start position:0% +have 90 percent of the gene there + + + align:start position:0% +have 90 percent of the gene there +that's been transcribed + + align:start position:0% +that's been transcribed + + + align:start position:0% +that's been transcribed +and that rna therefore is going to be + + align:start position:0% +and that rna therefore is going to be + + + align:start position:0% +and that rna therefore is going to be +registered by the expression array + + align:start position:0% + + + + align:start position:0% + +now you could say maybe exactly maybe i + + align:start position:0% +now you could say maybe exactly maybe i + + + align:start position:0% +now you could say maybe exactly maybe i +want to have a resequencing array + + align:start position:0% +want to have a resequencing array + + + align:start position:0% +want to have a resequencing array +let's just say that's another one slots + + align:start position:0% +let's just say that's another one slots + + + align:start position:0% +let's just say that's another one slots +we see we still have to see we sequence + + align:start position:0% +we see we still have to see we sequence + + + align:start position:0% +we see we still have to see we sequence +the gene + + align:start position:0% +the gene + + + align:start position:0% +the gene +no way around that + + align:start position:0% + + + + align:start position:0% + +okay where would you send it when we + + align:start position:0% +okay where would you send it when we + + + align:start position:0% +okay where would you send it when we +know the answer would look up gin tennis + + align:start position:0% +know the answer would look up gin tennis + + + align:start position:0% +know the answer would look up gin tennis +gene clinic + + align:start position:0% +gene clinic + + + align:start position:0% +gene clinic +test + + align:start position:0% +test + + + align:start position:0% +test +what we did to tell the parents and then + + align:start position:0% +what we did to tell the parents and then + + + align:start position:0% +what we did to tell the parents and then +you're obtaining of the consent well i'm + + align:start position:0% +you're obtaining of the consent well i'm + + + align:start position:0% +you're obtaining of the consent well i'm +running out of time + + align:start position:0% +running out of time + + + align:start position:0% +running out of time +but i think in addition to the things + + align:start position:0% +but i think in addition to the things + + + align:start position:0% +but i think in addition to the things +that we said before we actually have to + + align:start position:0% +that we said before we actually have to + + + align:start position:0% +that we said before we actually have to +tell them that + + align:start position:0% +tell them that + + + align:start position:0% +tell them that +we might not find uh the cause of it but + + align:start position:0% +we might not find uh the cause of it but + + + align:start position:0% +we might not find uh the cause of it but +that if the fathers + + align:start position:0% +that if the fathers + + + align:start position:0% +that if the fathers +shows up one thing that might be uh one + + align:start position:0% +shows up one thing that might be uh one + + + align:start position:0% +shows up one thing that might be uh one +result if and therefore we may only have + + align:start position:0% +result if and therefore we may only have + + + align:start position:0% +result if and therefore we may only have +to hack out a bit of the pancreas if the + + align:start position:0% +to hack out a bit of the pancreas if the + + + align:start position:0% +to hack out a bit of the pancreas if the +kid's homozygous for it we may have to + + align:start position:0% +kid's homozygous for it we may have to + + + align:start position:0% +kid's homozygous for it we may have to +take out the whole pancreas and so on + + align:start position:0% +take out the whole pancreas and so on + + + align:start position:0% +take out the whole pancreas and so on +so that's it for today + + align:start position:0% +so that's it for today + + + align:start position:0% +so that's it for today +that's really the state of the art of + + align:start position:0% +that's really the state of the art of + + + align:start position:0% +that's really the state of the art of +genomic medicine 2004. \ No newline at end of file diff --git a/2PpgEtgovN0.txt b/2PpgEtgovN0.txt new file mode 100644 index 0000000000000000000000000000000000000000..3198209718da5afce727c1990ffd91f8c5aa69db --- /dev/null +++ b/2PpgEtgovN0.txt @@ -0,0 +1,4635 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hi hopefully by now you have become well + + align:start position:0% +hi hopefully by now you have become well + + + align:start position:0% +hi hopefully by now you have become well +experienced at Computing limits of + + align:start position:0% +experienced at Computing limits of + + + align:start position:0% +experienced at Computing limits of +double sums you've learned to hate me a + + align:start position:0% +double sums you've learned to hate me a + + + align:start position:0% +double sums you've learned to hate me a +little bit more because the work was + + align:start position:0% +little bit more because the work was + + + align:start position:0% +little bit more because the work was +quite complicated and hopefully you are + + align:start position:0% +quite complicated and hopefully you are + + + align:start position:0% +quite complicated and hopefully you are +convinced that there must be an easier + + align:start position:0% +convinced that there must be an easier + + + align:start position:0% +convinced that there must be an easier +way to do this stuff and fortunately the + + align:start position:0% +way to do this stuff and fortunately the + + + align:start position:0% +way to do this stuff and fortunately the +answer is there is an easier way + + align:start position:0% +answer is there is an easier way + + + align:start position:0% +answer is there is an easier way +sometimes and the concept that we're + + align:start position:0% +sometimes and the concept that we're + + + align:start position:0% +sometimes and the concept that we're +going to talk about today is again + + align:start position:0% +going to talk about today is again + + + align:start position:0% +going to talk about today is again +completely analogous to what happened in + + align:start position:0% +completely analogous to what happened in + + + align:start position:0% +completely analogous to what happened in +calculus of a single variable where we + + align:start position:0% +calculus of a single variable where we + + + align:start position:0% +calculus of a single variable where we +showed that the concept of definite + + align:start position:0% +showed that the concept of definite + + + align:start position:0% +showed that the concept of definite +integral existed independently of being + + align:start position:0% +integral existed independently of being + + + align:start position:0% +integral existed independently of being +able to form derivatives but in the case + + align:start position:0% +able to form derivatives but in the case + + + align:start position:0% +able to form derivatives but in the case +where we knew a particular function + + align:start position:0% +where we knew a particular function + + + align:start position:0% +where we knew a particular function +whose derivative would be a given thing + + align:start position:0% +whose derivative would be a given thing + + + align:start position:0% +whose derivative would be a given thing +we were able to perform the infinite sum + + align:start position:0% +we were able to perform the infinite sum + + + align:start position:0% +we were able to perform the infinite sum +or compute the infinite sum much more + + align:start position:0% +or compute the infinite sum much more + + + align:start position:0% +or compute the infinite sum much more +readily than had we had to rely on the + + align:start position:0% +readily than had we had to rely on the + + + align:start position:0% +readily than had we had to rely on the +arithmetic of infinite series by the way + + align:start position:0% +arithmetic of infinite series by the way + + + align:start position:0% +arithmetic of infinite series by the way +and I'll mention this later in a + + align:start position:0% +and I'll mention this later in a + + + align:start position:0% +and I'll mention this later in a +different context I hope that the + + align:start position:0% +different context I hope that the + + + align:start position:0% +different context I hope that the +converse problem was also true that in + + align:start position:0% +converse problem was also true that in + + + align:start position:0% +converse problem was also true that in +many cases one did not know how to find + + align:start position:0% +many cases one did not know how to find + + + align:start position:0% +many cases one did not know how to find +the required function with the given + + align:start position:0% +the required function with the given + + + align:start position:0% +the required function with the given +derivative and in this case knowing how + + align:start position:0% +derivative and in this case knowing how + + + align:start position:0% +derivative and in this case knowing how +to find the area by the limit process + + align:start position:0% +to find the area by the limit process + + + align:start position:0% +to find the area by the limit process +was equivalent to how we were then able + + align:start position:0% +was equivalent to how we were then able + + + align:start position:0% +was equivalent to how we were then able +to invent new functions which had given + + align:start position:0% +to invent new functions which had given + + + align:start position:0% +to invent new functions which had given +derivatives essentially the difference + + align:start position:0% +derivatives essentially the difference + + + align:start position:0% +derivatives essentially the difference +in point of view was the difference + + align:start position:0% +in point of view was the difference + + + align:start position:0% +in point of view was the difference +between what we call the first + + align:start position:0% +between what we call the first + + + align:start position:0% +between what we call the first +fundamental theorem of integral calculus + + align:start position:0% +fundamental theorem of integral calculus + + + align:start position:0% +fundamental theorem of integral calculus +and the second fundamental theorem of + + align:start position:0% +and the second fundamental theorem of + + + align:start position:0% +and the second fundamental theorem of +integral calculus as I said the same + + align:start position:0% +integral calculus as I said the same + + + align:start position:0% +integral calculus as I said the same +analogy will here and let's get into + + align:start position:0% +analogy will here and let's get into + + + align:start position:0% +analogy will here and let's get into +this now without further Ado I call + + align:start position:0% +this now without further Ado I call + + + align:start position:0% +this now without further Ado I call +today's lesson the fundamental theorem + + align:start position:0% +today's lesson the fundamental theorem + + + align:start position:0% +today's lesson the fundamental theorem +and what I'm going to do now is to + + align:start position:0% +and what I'm going to do now is to + + + align:start position:0% +and what I'm going to do now is to +pretend that we never had the lecture of + + align:start position:0% +pretend that we never had the lecture of + + + align:start position:0% +pretend that we never had the lecture of +last time that we have never heard of an + + align:start position:0% +last time that we have never heard of an + + + align:start position:0% +last time that we have never heard of an +infinite sum and I'm going to introduce + + align:start position:0% +infinite sum and I'm going to introduce + + + align:start position:0% +infinite sum and I'm going to introduce +what one calls the anti-derivative of a + + align:start position:0% +what one calls the anti-derivative of a + + + align:start position:0% +what one calls the anti-derivative of a +function of two independent variables + + align:start position:0% +function of two independent variables + + + align:start position:0% +function of two independent variables +again keeping in mind the analogy that + + align:start position:0% +again keeping in mind the analogy that + + + align:start position:0% +again keeping in mind the analogy that +for more than two independent variables + + align:start position:0% +for more than two independent variables + + + align:start position:0% +for more than two independent variables +a similar treatment holds and the + + align:start position:0% +a similar treatment holds and the + + + align:start position:0% +a similar treatment holds and the +exercises will include problems that + + align:start position:0% +exercises will include problems that + + + align:start position:0% +exercises will include problems that +have more than two independent variables + + align:start position:0% +have more than two independent variables + + + align:start position:0% +have more than two independent variables +the idea is that when I write down this + + align:start position:0% +the idea is that when I write down this + + + align:start position:0% +the idea is that when I write down this +particular double integral if I look at + + align:start position:0% +particular double integral if I look at + + + align:start position:0% +particular double integral if I look at +the innermost integral notice that X + + align:start position:0% +the innermost integral notice that X + + + align:start position:0% +the innermost integral notice that X +appears only as a parameter that the + + align:start position:0% +appears only as a parameter that the + + + align:start position:0% +appears only as a parameter that the +variable of integration is y notice then + + align:start position:0% +variable of integration is y notice then + + + align:start position:0% +variable of integration is y notice then +that X is being treated as a constant we + + align:start position:0% +that X is being treated as a constant we + + + align:start position:0% +that X is being treated as a constant we +pick what this says is what pick a fixed + + align:start position:0% +pick what this says is what pick a fixed + + + align:start position:0% +pick what this says is what pick a fixed +value of x compute this + + align:start position:0% +value of x compute this + + + align:start position:0% +value of x compute this +integral evaluate this as y goes from G1 + + align:start position:0% +integral evaluate this as y goes from G1 + + + align:start position:0% +integral evaluate this as y goes from G1 +of x to G2 of X the resulting function + + align:start position:0% +of x to G2 of X the resulting function + + + align:start position:0% +of x to G2 of X the resulting function +is a function of X alone and integrate + + align:start position:0% +is a function of X alone and integrate + + + align:start position:0% +is a function of X alone and integrate +that function of x from A to B and to do + + align:start position:0% +that function of x from A to B and to do + + + align:start position:0% +that function of x from A to B and to do +that for you in slower motion so you see + + align:start position:0% +that for you in slower motion so you see + + + align:start position:0% +that for you in slower motion so you see +what happens here what I'm essentially + + align:start position:0% +what happens here what I'm essentially + + + align:start position:0% +what happens here what I'm essentially +saying is read this thing Inside Out + + align:start position:0% +saying is read this thing Inside Out + + + align:start position:0% +saying is read this thing Inside Out +imagine some brackets placed here not + + align:start position:0% +imagine some brackets placed here not + + + align:start position:0% +imagine some brackets placed here not +imagine them let's put them in and what + + align:start position:0% +imagine them let's put them in and what + + + align:start position:0% +imagine them let's put them in and what +we're saying is look at for first of all + + align:start position:0% +we're saying is look at for first of all + + + align:start position:0% +we're saying is look at for first of all +fix a value of x hold x constant and for + + align:start position:0% +fix a value of x hold x constant and for + + + align:start position:0% +fix a value of x hold x constant and for +that fixed value of x compute F ofx ydy + + align:start position:0% +that fixed value of x compute F ofx ydy + + + align:start position:0% +that fixed value of x compute F ofx ydy +from G1 of x to G2 of X compute that + + align:start position:0% +from G1 of x to G2 of X compute that + + + align:start position:0% +from G1 of x to G2 of X compute that +that's a fun remember that you're going + + align:start position:0% +that's a fun remember that you're going + + + align:start position:0% +that's a fun remember that you're going +to integrate that with respect to y when + + align:start position:0% +to integrate that with respect to y when + + + align:start position:0% +to integrate that with respect to y when +you're all through with this because the + + align:start position:0% +you're all through with this because the + + + align:start position:0% +you're all through with this because the +limits involve only X the integrant that + + align:start position:0% +limits involve only X the integrant that + + + align:start position:0% +limits involve only X the integrant that +you get in this bracketed expression + + align:start position:0% +you get in this bracketed expression + + + align:start position:0% +you get in this bracketed expression +will now be a function of X alone call + + align:start position:0% +will now be a function of X alone call + + + align:start position:0% +will now be a function of X alone call +it h of X integrate h of X DX between a + + align:start position:0% +it h of X integrate h of X DX between a + + + align:start position:0% +it h of X integrate h of X DX between a +and b and the resulting expression + + align:start position:0% +and b and the resulting expression + + + align:start position:0% +and b and the resulting expression +assuming that you can carry out the + + align:start position:0% +assuming that you can carry out the + + + align:start position:0% +assuming that you can carry out the +integration of course will be a + + align:start position:0% +integration of course will be a + + + align:start position:0% +integration of course will be a +particular number all right that has + + align:start position:0% +particular number all right that has + + + align:start position:0% +particular number all right that has +nothing to do as I say with double sum + + align:start position:0% +nothing to do as I say with double sum + + + align:start position:0% +nothing to do as I say with double sum +so far though I suspect that you're + + align:start position:0% +so far though I suspect that you're + + + align:start position:0% +so far though I suspect that you're +getting a bit supicious and the same way + + align:start position:0% +getting a bit supicious and the same way + + + align:start position:0% +getting a bit supicious and the same way +that the definite integral was a sum and + + align:start position:0% +that the definite integral was a sum and + + + align:start position:0% +that the definite integral was a sum and +not an anti-derivative it looked enough + + align:start position:0% +not an anti-derivative it looked enough + + + align:start position:0% +not an anti-derivative it looked enough +like the the notation of the definite + + align:start position:0% +like the the notation of the definite + + + align:start position:0% +like the the notation of the definite +integral looked enough like the notation + + align:start position:0% +integral looked enough like the notation + + + align:start position:0% +integral looked enough like the notation +of the indefinite integral so that we + + align:start position:0% +of the indefinite integral so that we + + + align:start position:0% +of the indefinite integral so that we +began to suspect there was going to be a + + align:start position:0% +began to suspect there was going to be a + + + align:start position:0% +began to suspect there was going to be a +connection between them that connection + + align:start position:0% +connection between them that connection + + + align:start position:0% +connection between them that connection +is what's going to be called the + + align:start position:0% +is what's going to be called the + + + align:start position:0% +is what's going to be called the +fundamental theorem in our present case + + align:start position:0% +fundamental theorem in our present case + + + align:start position:0% +fundamental theorem in our present case +but going on let me just give you an + + align:start position:0% +but going on let me just give you an + + + align:start position:0% +but going on let me just give you an +example showing you how we compute how + + align:start position:0% +example showing you how we compute how + + + align:start position:0% +example showing you how we compute how +we compute the anti-derivative let's + + align:start position:0% +we compute the anti-derivative let's + + + align:start position:0% +we compute the anti-derivative let's +take for example integral from 0 to 2 + + align:start position:0% +take for example integral from 0 to 2 + + + align:start position:0% +take for example integral from 0 to 2 +integral from 0 to x^2 x Cub y Dy DX + + align:start position:0% +integral from 0 to x^2 x Cub y Dy DX + + + align:start position:0% +integral from 0 to x^2 x Cub y Dy DX +again we go from inside to out the way + + align:start position:0% +again we go from inside to out the way + + + align:start position:0% +again we go from inside to out the way +we read this is that we're integrating + + align:start position:0% +we read this is that we're integrating + + + align:start position:0% +we read this is that we're integrating +with respect to Y that means we're + + align:start position:0% +with respect to Y that means we're + + + align:start position:0% +with respect to Y that means we're +holding x constant for a fixed value of + + align:start position:0% +holding x constant for a fixed value of + + + align:start position:0% +holding x constant for a fixed value of +x integrate this as y goes from 0 to x^2 + + align:start position:0% +x integrate this as y goes from 0 to x^2 + + + align:start position:0% +x integrate this as y goes from 0 to x^2 +so treating X as a constant I integrate + + align:start position:0% +so treating X as a constant I integrate + + + align:start position:0% +so treating X as a constant I integrate +this with respect to Y the integral of + + align:start position:0% +this with respect to Y the integral of + + + align:start position:0% +this with respect to Y the integral of +yd Y is 12 y^2 I evaluate that as y goes + + align:start position:0% +yd Y is 12 y^2 I evaluate that as y goes + + + align:start position:0% +yd Y is 12 y^2 I evaluate that as y goes +from 0 to x^2 that's crucial you see + + align:start position:0% +from 0 to x^2 that's crucial you see + + + align:start position:0% +from 0 to x^2 that's crucial you see +it's y that goes from 0 to x^2 when I + + align:start position:0% +it's y that goes from 0 to x^2 when I + + + align:start position:0% +it's y that goes from 0 to x^2 when I +replace y by the upper limit I get 12 x + + align:start position:0% +replace y by the upper limit I get 12 x + + + align:start position:0% +replace y by the upper limit I get 12 x +cubed time the quantity x^2 s when I + + align:start position:0% +cubed time the quantity x^2 s when I + + + align:start position:0% +cubed time the quantity x^2 s when I +replace y by the lower limit zero the + + align:start position:0% +replace y by the lower limit zero the + + + align:start position:0% +replace y by the lower limit zero the +integrand vanishes so that what I wind + + align:start position:0% +integrand vanishes so that what I wind + + + align:start position:0% +integrand vanishes so that what I wind +up with is a function of X alone + + align:start position:0% +up with is a function of X alone + + + align:start position:0% +up with is a function of X alone +specifically what function is it it's 12 + + align:start position:0% +specifically what function is it it's 12 + + + align:start position:0% +specifically what function is it it's 12 +x the 7th and I now integrate that from + + align:start position:0% +x the 7th and I now integrate that from + + + align:start position:0% +x the 7th and I now integrate that from +0 to 2 that gives me 1/8 x to 8 over 2 + + align:start position:0% +0 to 2 that gives me 1/8 x to 8 over 2 + + + align:start position:0% +0 to 2 that gives me 1/8 x to 8 over 2 +that's x 8 over 16 evaluated between 0 + + align:start position:0% +that's x 8 over 16 evaluated between 0 + + + align:start position:0% +that's x 8 over 16 evaluated between 0 +and 2 2 to 8 over 16 is 2 8 over 2 4th + + align:start position:0% +and 2 2 to 8 over 16 is 2 8 over 2 4th + + + align:start position:0% +and 2 2 to 8 over 16 is 2 8 over 2 4th +which is 2 4th which in turn is 16 so + + align:start position:0% +which is 2 4th which in turn is 16 so + + + align:start position:0% +which is 2 4th which in turn is 16 so +again notice I can carry out this + + align:start position:0% +again notice I can carry out this + + + align:start position:0% +again notice I can carry out this +operation purely manipulatively it is + + align:start position:0% +operation purely manipulatively it is + + + align:start position:0% +operation purely manipulatively it is +truly the inverse of diff of taking the + + align:start position:0% +truly the inverse of diff of taking the + + + align:start position:0% +truly the inverse of diff of taking the +partial derivative in the same way that + + align:start position:0% +partial derivative in the same way that + + + align:start position:0% +partial derivative in the same way that +taking the partial derivative involved + + align:start position:0% +taking the partial derivative involved + + + align:start position:0% +taking the partial derivative involved +holding all the variables but one + + align:start position:0% +holding all the variables but one + + + align:start position:0% +holding all the variables but one +constant taking a partial integral so to + + align:start position:0% +constant taking a partial integral so to + + + align:start position:0% +constant taking a partial integral so to +speak an anti-derivative involves simply + + align:start position:0% +speak an anti-derivative involves simply + + + align:start position:0% +speak an anti-derivative involves simply +doing what integrating treating all the + + align:start position:0% +doing what integrating treating all the + + + align:start position:0% +doing what integrating treating all the +variables but the given one as a + + align:start position:0% +variables but the given one as a + + + align:start position:0% +variables but the given one as a +constant which reduces you again to the + + align:start position:0% +constant which reduces you again to the + + + align:start position:0% +constant which reduces you again to the +equivalent of what the anti-derivative + + align:start position:0% +equivalent of what the anti-derivative + + + align:start position:0% +equivalent of what the anti-derivative +meant in the calculus of a single + + align:start position:0% +meant in the calculus of a single + + + align:start position:0% +meant in the calculus of a single +variable now here's where we come to the + + align:start position:0% +variable now here's where we come to the + + + align:start position:0% +variable now here's where we come to the +so-called fundamental theorem Let Me Tie + + align:start position:0% +so-called fundamental theorem Let Me Tie + + + align:start position:0% +so-called fundamental theorem Let Me Tie +what we've talked about today and what + + align:start position:0% +what we've talked about today and what + + + align:start position:0% +what we've talked about today and what +we talked about last time let me see if + + align:start position:0% +we talked about last time let me see if + + + align:start position:0% +we talked about last time let me see if +I can tie those together for you in a + + align:start position:0% +I can tie those together for you in a + + + align:start position:0% +I can tie those together for you in a +completely different way meaning I want + + align:start position:0% +completely different way meaning I want + + + align:start position:0% +completely different way meaning I want +I want you to see that conceptually + + align:start position:0% +I want you to see that conceptually + + + align:start position:0% +I want you to see that conceptually +today's lesson and last time's lesson + + align:start position:0% +today's lesson and last time's lesson + + + align:start position:0% +today's lesson and last time's lesson +are completely different but that the + + align:start position:0% +are completely different but that the + + + align:start position:0% +are completely different but that the +punch line is there's a remarkable + + align:start position:0% +punch line is there's a remarkable + + + align:start position:0% +punch line is there's a remarkable +connection between the two let's suppose + + align:start position:0% +connection between the two let's suppose + + + align:start position:0% +connection between the two let's suppose +I take the region R which is a very + + align:start position:0% +I take the region R which is a very + + + align:start position:0% +I take the region R which is a very +simple region it's bounded above by the + + align:start position:0% +simple region it's bounded above by the + + + align:start position:0% +simple region it's bounded above by the +curve y equals G2 of X it's bounded + + align:start position:0% +curve y equals G2 of X it's bounded + + + align:start position:0% +curve y equals G2 of X it's bounded +below by the curve yal G1 ofx and these + + align:start position:0% +below by the curve yal G1 ofx and these + + + align:start position:0% +below by the curve yal G1 ofx and these +two curves happen to intersect at values + + align:start position:0% +two curves happen to intersect at values + + + align:start position:0% +two curves happen to intersect at values +corresponding to X A and xal B and what + + align:start position:0% +corresponding to X A and xal B and what + + + align:start position:0% +corresponding to X A and xal B and what +I would like to + + align:start position:0% +I would like to + + + align:start position:0% +I would like to +find is the + + align:start position:0% +find is the + + + align:start position:0% +find is the +mass of the region R if its density is + + align:start position:0% +mass of the region R if its density is + + + align:start position:0% +mass of the region R if its density is +some given function f of x y now in + + align:start position:0% +some given function f of x y now in + + + align:start position:0% +some given function f of x y now in +terms of what we did last time this + + align:start position:0% +terms of what we did last time this + + + align:start position:0% +terms of what we did last time this +involved a double sum what double sum + + align:start position:0% +involved a double sum what double sum + + + align:start position:0% +involved a double sum what double sum +was it we partitioned this into + + align:start position:0% +was it we partitioned this into + + + align:start position:0% +was it we partitioned this into +rectangles Etc we picked a particular + + align:start position:0% +rectangles Etc we picked a particular + + + align:start position:0% +rectangles Etc we picked a particular +number c sub i j comma d sub J in the I + + align:start position:0% +number c sub i j comma d sub J in the I + + + align:start position:0% +number c sub i j comma d sub J in the I +rectangle we + + align:start position:0% +rectangle we + + + align:start position:0% +rectangle we +computed F of C sub i j comma d sub i j + + align:start position:0% +computed F of C sub i j comma d sub i j + + + align:start position:0% +computed F of C sub i j comma d sub i j +time Delta a sub i j added these all up + + align:start position:0% +time Delta a sub i j added these all up + + + align:start position:0% +time Delta a sub i j added these all up +the double sum as I went from 1 to n and + + align:start position:0% +the double sum as I went from 1 to n and + + + align:start position:0% +the double sum as I went from 1 to n and +J went went from 1 to M and took the + + align:start position:0% +J went went from 1 to M and took the + + + align:start position:0% +J went went from 1 to M and took the +limit as the + + align:start position:0% +limit as the + + + align:start position:0% +limit as the +maximum Delta x i and Delta YJ approach + + align:start position:0% +maximum Delta x i and Delta YJ approach + + + align:start position:0% +maximum Delta x i and Delta YJ approach +zero and that limit if it existed and it + + align:start position:0% +zero and that limit if it existed and it + + + align:start position:0% +zero and that limit if it existed and it +would exist if F was pie Y is continuous + + align:start position:0% +would exist if F was pie Y is continuous + + + align:start position:0% +would exist if F was pie Y is continuous +that limit was denoted by what double + + align:start position:0% +that limit was denoted by what double + + + align:start position:0% +that limit was denoted by what double +integral over the region r f ofx y d da + + align:start position:0% +integral over the region r f ofx y d da + + + align:start position:0% +integral over the region r f ofx y d da +and that da could either be viewed as + + align:start position:0% +and that da could either be viewed as + + + align:start position:0% +and that da could either be viewed as +being dydx if you wanted it could be DX + + align:start position:0% +being dydx if you wanted it could be DX + + + align:start position:0% +being dydx if you wanted it could be DX +Dy it could also be say in different + + align:start position:0% +Dy it could also be say in different + + + align:start position:0% +Dy it could also be say in different +coordinate systems we're not going to + + align:start position:0% +coordinate systems we're not going to + + + align:start position:0% +coordinate systems we're not going to +worry about that part just yet we'll + + align:start position:0% +worry about that part just yet we'll + + + align:start position:0% +worry about that part just yet we'll +worry about that in future lectures now + + align:start position:0% +worry about that in future lectures now + + + align:start position:0% +worry about that in future lectures now +on the other hand let's stop right here + + align:start position:0% +on the other hand let's stop right here + + + align:start position:0% +on the other hand let's stop right here +for a moment let's see how one might + + align:start position:0% +for a moment let's see how one might + + + align:start position:0% +for a moment let's see how one might +have been tempted to tackle this problem + + align:start position:0% +have been tempted to tackle this problem + + + align:start position:0% +have been tempted to tackle this problem +from a completely intuitive point of + + align:start position:0% +from a completely intuitive point of + + + align:start position:0% +from a completely intuitive point of +view the so-called engineering approach + + align:start position:0% +view the so-called engineering approach + + + align:start position:0% +view the so-called engineering approach +if you had never heard of the + + align:start position:0% +if you had never heard of the + + + align:start position:0% +if you had never heard of the +anti-derivative but had had + + align:start position:0% +anti-derivative but had had + + + align:start position:0% +anti-derivative but had had +anti-derivative for several variables + + align:start position:0% +anti-derivative for several variables + + + align:start position:0% +anti-derivative for several variables +but had taken part one of our course the + + align:start position:0% +but had taken part one of our course the + + + align:start position:0% +but had taken part one of our course the +engineering approach would be something + + align:start position:0% +engineering approach would be something + + + align:start position:0% +engineering approach would be something +like this you would say let's pick a + + align:start position:0% +like this you would say let's pick a + + + align:start position:0% +like this you would say let's pick a +very small infinitesimal region here in + + align:start position:0% +very small infinitesimal region here in + + + align:start position:0% +very small infinitesimal region here in +which we can assume that the density is + + align:start position:0% +which we can assume that the density is + + + align:start position:0% +which we can assume that the density is +constant so we'll pick a little region + + align:start position:0% +constant so we'll pick a little region + + + align:start position:0% +constant so we'll pick a little region +that's a very very small rectangle of + + align:start position:0% +that's a very very small rectangle of + + + align:start position:0% +that's a very very small rectangle of +Dimension what we'll say it's Dy by + + align:start position:0% + + + + align:start position:0% + +DX and the density of this particular + + align:start position:0% +DX and the density of this particular + + + align:start position:0% +DX and the density of this particular +rectangle can be assumed to be the + + align:start position:0% +rectangle can be assumed to be the + + + align:start position:0% +rectangle can be assumed to be the +constant value f ofx + + align:start position:0% + + + + align:start position:0% + +y because that density is constant the + + align:start position:0% +y because that density is constant the + + + align:start position:0% +y because that density is constant the +mass of this little piece should be f + + align:start position:0% +mass of this little piece should be f + + + align:start position:0% +mass of this little piece should be f +ofx y * + + align:start position:0% +ofx y * + + + align:start position:0% +ofx y * +dydx and then we say what let's add + + align:start position:0% +dydx and then we say what let's add + + + align:start position:0% +dydx and then we say what let's add +these all up see let's go down to here + + align:start position:0% +these all up see let's go down to here + + + align:start position:0% +these all up see let's go down to here +now we say look at this is a typical + + align:start position:0% +now we say look at this is a typical + + + align:start position:0% +now we say look at this is a typical +element and we'll add them all up for + + align:start position:0% +element and we'll add them all up for + + + align:start position:0% +element and we'll add them all up for +all possible y's and all possible X's + + align:start position:0% +all possible y's and all possible X's + + + align:start position:0% +all possible y's and all possible X's +now how would you do this intuitively + + align:start position:0% +now how would you do this intuitively + + + align:start position:0% +now how would you do this intuitively +you'd say well look + + align:start position:0% +you'd say well look + + + align:start position:0% +you'd say well look +let me hold x constant well for a + + align:start position:0% +let me hold x constant well for a + + + align:start position:0% +let me hold x constant well for a +constant value of x let's call it x sub + + align:start position:0% +constant value of x let's call it x sub + + + align:start position:0% +constant value of x let's call it x sub +one for a constant value of x notice + + align:start position:0% +one for a constant value of x notice + + + align:start position:0% +one for a constant value of x notice +that y can vary any place to be in the + + align:start position:0% +that y can vary any place to be in the + + + align:start position:0% +that y can vary any place to be in the +region R for that fixed value of x y can + + align:start position:0% +region R for that fixed value of x y can + + + align:start position:0% +region R for that fixed value of x y can +be any place from here to here in other + + align:start position:0% +be any place from here to here in other + + + align:start position:0% +be any place from here to here in other +words y varies continuously from G1 of + + align:start position:0% +words y varies continuously from G1 of + + + align:start position:0% +words y varies continuously from G1 of +X1 to G2 of X1 all right because X1 + + align:start position:0% +X1 to G2 of X1 all right because X1 + + + align:start position:0% +X1 to G2 of X1 all right because X1 +could have been any X Y VAR for that + + align:start position:0% +could have been any X Y VAR for that + + + align:start position:0% +could have been any X Y VAR for that +given X Y varies continuously from G1 of + + align:start position:0% +given X Y varies continuously from G1 of + + + align:start position:0% +given X Y varies continuously from G1 of +x to G2 of x X and notice that X could + + align:start position:0% +x to G2 of x X and notice that X could + + + align:start position:0% +x to G2 of x X and notice that X could +have been chosen if we want to be in the + + align:start position:0% +have been chosen if we want to be in the + + + align:start position:0% +have been chosen if we want to be in the +region R to be any place from A to B and + + align:start position:0% +region R to be any place from A to B and + + + align:start position:0% +region R to be any place from A to B and +so mechanically we might say let's just + + align:start position:0% +so mechanically we might say let's just + + + align:start position:0% +so mechanically we might say let's just +say here's the mass of a small element + + align:start position:0% +say here's the mass of a small element + + + align:start position:0% +say here's the mass of a small element +and we'll add these all up so that for a + + align:start position:0% +and we'll add these all up so that for a + + + align:start position:0% +and we'll add these all up so that for a +fixed X Y goes from G1 of x to G2 of X + + align:start position:0% +fixed X Y goes from G1 of x to G2 of X + + + align:start position:0% +fixed X Y goes from G1 of x to G2 of X +and X can be anywhere from A to B and it + + align:start position:0% +and X can be anywhere from A to B and it + + + align:start position:0% +and X can be anywhere from A to B and it +appears that this is a + + align:start position:0% +appears that this is a + + + align:start position:0% +appears that this is a +truism this is not a truism it's a + + align:start position:0% +truism this is not a truism it's a + + + align:start position:0% +truism this is not a truism it's a +rather remarkable result it is analogous + + align:start position:0% +rather remarkable result it is analogous + + + align:start position:0% +rather remarkable result it is analogous +to what happened in calculus of a single + + align:start position:0% +to what happened in calculus of a single + + + align:start position:0% +to what happened in calculus of a single +variable namely notice that when we had + + align:start position:0% +variable namely notice that when we had + + + align:start position:0% +variable namely notice that when we had +the definite integral from A to B F ofx + + align:start position:0% +the definite integral from A to B F ofx + + + align:start position:0% +the definite integral from A to B F ofx +DX that was an infinite sum it was + + align:start position:0% +DX that was an infinite sum it was + + + align:start position:0% +DX that was an infinite sum it was +summation F of C subk Delta X subk as K + + align:start position:0% +summation F of C subk Delta X subk as K + + + align:start position:0% +summation F of C subk Delta X subk as K +went from 1 to n taken in the limit as + + align:start position:0% +went from 1 to n taken in the limit as + + + align:start position:0% +went from 1 to n taken in the limit as +the maximum Delta x sub K approached + + align:start position:0% +the maximum Delta x sub K approached + + + align:start position:0% +the maximum Delta x sub K approached +zero it turned out that if we knew a + + align:start position:0% +zero it turned out that if we knew a + + + align:start position:0% +zero it turned out that if we knew a +function capital F whose derivative was + + align:start position:0% +function capital F whose derivative was + + + align:start position:0% +function capital F whose derivative was +little F then this sum could be + + align:start position:0% +little F then this sum could be + + + align:start position:0% +little F then this sum could be +evaluated by Computing capital F of B + + align:start position:0% +evaluated by Computing capital F of B + + + align:start position:0% +evaluated by Computing capital F of B +minus capital F of a again the idea + + align:start position:0% +minus capital F of a again the idea + + + align:start position:0% +minus capital F of a again the idea +being that if you knew a function whose + + align:start position:0% +being that if you knew a function whose + + + align:start position:0% +being that if you knew a function whose +derivative was F that gave you an easy + + align:start position:0% +derivative was F that gave you an easy + + + align:start position:0% +derivative was F that gave you an easy +way to evaluate the sum on the other + + align:start position:0% +way to evaluate the sum on the other + + + align:start position:0% +way to evaluate the sum on the other +hand if you could if you didn't know a + + align:start position:0% +hand if you could if you didn't know a + + + align:start position:0% +hand if you could if you didn't know a +function whose derivative was little F + + align:start position:0% +function whose derivative was little F + + + align:start position:0% +function whose derivative was little F +evaluating the sum as a limit gave you a + + align:start position:0% +evaluating the sum as a limit gave you a + + + align:start position:0% +evaluating the sum as a limit gave you a +way of being able to find the + + align:start position:0% +way of being able to find the + + + align:start position:0% +way of being able to find the +anti-derivative a particular case in + + align:start position:0% +anti-derivative a particular case in + + + align:start position:0% +anti-derivative a particular case in +point you may recall was trying to + + align:start position:0% +point you may recall was trying to + + + align:start position:0% +point you may recall was trying to +handle the problem e to the- x^2 DX as X + + align:start position:0% +handle the problem e to the- x^2 DX as X + + + align:start position:0% +handle the problem e to the- x^2 DX as X +goes from 0 to 1 this certainly existed + + align:start position:0% +goes from 0 to 1 this certainly existed + + + align:start position:0% +goes from 0 to 1 this certainly existed +as an area but we did not know in fact + + align:start position:0% +as an area but we did not know in fact + + + align:start position:0% +as an area but we did not know in fact +there is no Elementary function we + + align:start position:0% +there is no Elementary function we + + + align:start position:0% +there is no Elementary function we +invented one called the error function + + align:start position:0% +invented one called the error function + + + align:start position:0% +invented one called the error function +whose derivative is eus x^2 so the idea + + align:start position:0% +whose derivative is eus x^2 so the idea + + + align:start position:0% +whose derivative is eus x^2 so the idea +is and this is this is the key point + + align:start position:0% +is and this is this is the key point + + + align:start position:0% +is and this is this is the key point +this is what becomes known as the + + align:start position:0% +this is what becomes known as the + + + align:start position:0% +this is what becomes known as the +fundamental theorem for several + + align:start position:0% +fundamental theorem for several + + + align:start position:0% +fundamental theorem for several +variables that there is a connection + + align:start position:0% +variables that there is a connection + + + align:start position:0% +variables that there is a connection +between a double infinite sum and a + + align:start position:0% +between a double infinite sum and a + + + align:start position:0% +between a double infinite sum and a +double anti-derivative + + align:start position:0% +double anti-derivative + + + align:start position:0% +double anti-derivative +that this particular expression here + + align:start position:0% +that this particular expression here + + + align:start position:0% +that this particular expression here +does not involve knowing anything about + + align:start position:0% +does not involve knowing anything about + + + align:start position:0% +does not involve knowing anything about +partial derivatives this particular + + align:start position:0% +partial derivatives this particular + + + align:start position:0% +partial derivatives this particular +expression here does not involve being a + + align:start position:0% +expression here does not involve being a + + + align:start position:0% +expression here does not involve being a +any knowledge of knowing partial sums + + align:start position:0% +any knowledge of knowing partial sums + + + align:start position:0% +any knowledge of knowing partial sums +this simply says + + align:start position:0% +this simply says + + + align:start position:0% +this simply says +what integrate this thing twice once + + align:start position:0% +what integrate this thing twice once + + + align:start position:0% +what integrate this thing twice once +holding x constant and letting y go from + + align:start position:0% +holding x constant and letting y go from + + + align:start position:0% +holding x constant and letting y go from +G1 of x to G2 of X and then integrating + + align:start position:0% +G1 of x to G2 of X and then integrating + + + align:start position:0% +G1 of x to G2 of X and then integrating +with respect to X and the amazing result + + align:start position:0% +with respect to X and the amazing result + + + align:start position:0% +with respect to X and the amazing result +is that if f is + + align:start position:0% +is that if f is + + + align:start position:0% +is that if f is +continuous this limit exists and in + + align:start position:0% +continuous this limit exists and in + + + align:start position:0% +continuous this limit exists and in +particular if we happen to know how to + + align:start position:0% +particular if we happen to know how to + + + align:start position:0% +particular if we happen to know how to +actually carry out these repeated or + + align:start position:0% +actually carry out these repeated or + + + align:start position:0% +actually carry out these repeated or +iterated in Integrations we can compute + + align:start position:0% +iterated in Integrations we can compute + + + align:start position:0% +iterated in Integrations we can compute +this complicated sum simply by carrying + + align:start position:0% +this complicated sum simply by carrying + + + align:start position:0% +this complicated sum simply by carrying +out this anti-derivative and I think the + + align:start position:0% +out this anti-derivative and I think the + + + align:start position:0% +out this anti-derivative and I think the +best way to emphasize that to you is to + + align:start position:0% +best way to emphasize that to you is to + + + align:start position:0% +best way to emphasize that to you is to +repeat the punchline to the homework + + align:start position:0% +repeat the punchline to the homework + + + align:start position:0% +repeat the punchline to the homework +exercises of last assignment you may + + align:start position:0% +exercises of last assignment you may + + + align:start position:0% +exercises of last assignment you may +recall that last time we were dealing + + align:start position:0% +recall that last time we were dealing + + + align:start position:0% +recall that last time we were dealing +with the square whose vertices were Z 0 + + align:start position:0% +with the square whose vertices were Z 0 + + + align:start position:0% +with the square whose vertices were Z 0 +1 0 1 1 and 0 1 the density of the + + align:start position:0% +1 0 1 1 and 0 1 the density of the + + + align:start position:0% +1 0 1 1 and 0 1 the density of the +square at the point x comma y was x^2 + + + align:start position:0% +square at the point x comma y was x^2 + + + + align:start position:0% +square at the point x comma y was x^2 + +y^2 and I asked you as a homework + + align:start position:0% +y^2 and I asked you as a homework + + + align:start position:0% +y^2 and I asked you as a homework +problem to compute the mass of this + + align:start position:0% +problem to compute the mass of this + + + align:start position:0% +problem to compute the mass of this +plate R to compute it exactly and what + + align:start position:0% +plate R to compute it exactly and what + + + align:start position:0% +plate R to compute it exactly and what +we said was okay by definition + + align:start position:0% +we said was okay by definition + + + align:start position:0% +we said was okay by definition +of remember this thing here now with the + + align:start position:0% +of remember this thing here now with the + + + align:start position:0% +of remember this thing here now with the +r under here indicates a double a limit + + align:start position:0% +r under here indicates a double a limit + + + align:start position:0% +r under here indicates a double a limit +of a double sum that this Mass was by + + align:start position:0% +of a double sum that this Mass was by + + + align:start position:0% +of a double sum that this Mass was by +definition this particular result and + + align:start position:0% +definition this particular result and + + + align:start position:0% +definition this particular result and +notice that last time we + + align:start position:0% +notice that last time we + + + align:start position:0% +notice that last time we +showed in terms of double sums that this + + align:start position:0% +showed in terms of double sums that this + + + align:start position:0% +showed in terms of double sums that this +came out to be 2/3 let me show you in + + align:start position:0% +came out to be 2/3 let me show you in + + + align:start position:0% +came out to be 2/3 let me show you in +terms of our new Theory how we can find + + align:start position:0% +terms of our new Theory how we can find + + + align:start position:0% +terms of our new Theory how we can find +this much more conveniently with no + + align:start position:0% +this much more conveniently with no + + + align:start position:0% +this much more conveniently with no +sweat so to speak what I'm going to do + + align:start position:0% +sweat so to speak what I'm going to do + + + align:start position:0% +sweat so to speak what I'm going to do +now is the following the same analogy I + + align:start position:0% +now is the following the same analogy I + + + align:start position:0% +now is the following the same analogy I +used before I look at my region here + + align:start position:0% +used before I look at my region here + + + align:start position:0% +used before I look at my region here +which I'll call a and I say what for a + + align:start position:0% +which I'll call a and I say what for a + + + align:start position:0% +which I'll call a and I say what for a +fixed value of x for a fixed value of x + + align:start position:0% +fixed value of x for a fixed value of x + + + align:start position:0% +fixed value of x for a fixed value of x +notice that y varies continuously from + + align:start position:0% +notice that y varies continuously from + + + align:start position:0% +notice that y varies continuously from +0er to one see y varies continuously + + align:start position:0% +0er to one see y varies continuously + + + align:start position:0% +0er to one see y varies continuously +from 0er to one and that X in turn could + + align:start position:0% +from 0er to one and that X in turn could + + + align:start position:0% +from 0er to one and that X in turn could +have been chosen to be any place from 0 + + align:start position:0% +have been chosen to be any place from 0 + + + align:start position:0% +have been chosen to be any place from 0 +to one that as we run through all of + + align:start position:0% +to one that as we run through all of + + + align:start position:0% +to one that as we run through all of +these strips added up from 0 to one that + + align:start position:0% +these strips added up from 0 to one that + + + align:start position:0% +these strips added up from 0 to one that +covers our region R so what we're saying + + align:start position:0% +covers our region R so what we're saying + + + align:start position:0% +covers our region R so what we're saying +is all right our little element of our + + align:start position:0% +is all right our little element of our + + + align:start position:0% +is all right our little element of our +mass will be x^2 + y s Dy DX We'll add + + align:start position:0% +mass will be x^2 + y s Dy DX We'll add + + + align:start position:0% +mass will be x^2 + y s Dy DX We'll add +these all up from 0 to 1 holding x + + align:start position:0% +these all up from 0 to 1 holding x + + + align:start position:0% +these all up from 0 to 1 holding x +constant then add them all up again as X + + align:start position:0% +constant then add them all up again as X + + + align:start position:0% +constant then add them all up again as X +goes from 0 to 1 again this is the + + align:start position:0% +goes from 0 to 1 again this is the + + + align:start position:0% +goes from 0 to 1 again this is the +iterated integral how do we evaluate + + align:start position:0% +iterated integral how do we evaluate + + + align:start position:0% +iterated integral how do we evaluate +this well we treat X as a constant + + align:start position:0% +this well we treat X as a constant + + + align:start position:0% +this well we treat X as a constant +integrate this with respect to Y if + + align:start position:0% +integrate this with respect to Y if + + + align:start position:0% +integrate this with respect to Y if +we're treating X as a constant this + + align:start position:0% +we're treating X as a constant this + + + align:start position:0% +we're treating X as a constant this +integral comes out to be x^2 y + 1/3 y + + align:start position:0% +integral comes out to be x^2 y + 1/3 y + + + align:start position:0% +integral comes out to be x^2 y + 1/3 y +cubed and we now evaluate that as y goes + + align:start position:0% +cubed and we now evaluate that as y goes + + + align:start position:0% +cubed and we now evaluate that as y goes +from 0 to 1 leaving these details out + + align:start position:0% +from 0 to 1 leaving these details out + + + align:start position:0% +from 0 to 1 leaving these details out +because they are essentially the + + align:start position:0% +because they are essentially the + + + align:start position:0% +because they are essentially the +calculus of a single variable all over + + align:start position:0% +calculus of a single variable all over + + + align:start position:0% +calculus of a single variable all over +again this turns out to be the integral + + align:start position:0% +again this turns out to be the integral + + + align:start position:0% +again this turns out to be the integral +from 0 to 1 x^2 + 1/3 DX which in turn + + align:start position:0% +from 0 to 1 x^2 + 1/3 DX which in turn + + + align:start position:0% +from 0 to 1 x^2 + 1/3 DX which in turn +is 1/3 x Cub + 1/3 x evaluated as X goes + + align:start position:0% +is 1/3 x Cub + 1/3 x evaluated as X goes + + + align:start position:0% +is 1/3 x Cub + 1/3 x evaluated as X goes +from 0 to 1 the upper limit gives me a + + align:start position:0% +from 0 to 1 the upper limit gives me a + + + align:start position:0% +from 0 to 1 the upper limit gives me a +thir plus a thir the lower limit zero + + align:start position:0% +thir plus a thir the lower limit zero + + + align:start position:0% +thir plus a thir the lower limit zero +the mass here is + + align:start position:0% + + + + align:start position:0% + +2/3 which checks with the result that we + + align:start position:0% +2/3 which checks with the result that we + + + align:start position:0% +2/3 which checks with the result that we +got last + + align:start position:0% +got last + + + align:start position:0% +got last +time again I'm not going to go through + + align:start position:0% +time again I'm not going to go through + + + align:start position:0% +time again I'm not going to go through +the proof of the fundamental theorem I + + align:start position:0% +the proof of the fundamental theorem I + + + align:start position:0% +the proof of the fundamental theorem I +don't think it's that crucial it's + + align:start position:0% +don't think it's that crucial it's + + + align:start position:0% +don't think it's that crucial it's +available in textbooks on Advanced + + align:start position:0% +available in textbooks on Advanced + + + align:start position:0% +available in textbooks on Advanced +calculus uh some of the exercises may + + align:start position:0% +calculus uh some of the exercises may + + + align:start position:0% +calculus uh some of the exercises may +possibly give you hints as to how these + + align:start position:0% +possibly give you hints as to how these + + + align:start position:0% +possibly give you hints as to how these +results come about but by and large I'm + + align:start position:0% +results come about but by and large I'm + + + align:start position:0% +results come about but by and large I'm +more interested now in you seeing the + + align:start position:0% +more interested now in you seeing the + + + align:start position:0% +more interested now in you seeing the +overview and at this stage of the game + + align:start position:0% +overview and at this stage of the game + + + align:start position:0% +overview and at this stage of the game +letting you get whatever specific + + align:start position:0% +letting you get whatever specific + + + align:start position:0% +letting you get whatever specific +theoretical details you desire on your + + align:start position:0% +theoretical details you desire on your + + + align:start position:0% +theoretical details you desire on your +own all right at any rate let's continue + + align:start position:0% +own all right at any rate let's continue + + + align:start position:0% +own all right at any rate let's continue +on with examples uh I think a very nice + + align:start position:0% +on with examples uh I think a very nice + + + align:start position:0% +on with examples uh I think a very nice +counterpart to example one and to + + align:start position:0% +counterpart to example one and to + + + align:start position:0% +counterpart to example one and to +refresh your memories looking back at it + + align:start position:0% +refresh your memories looking back at it + + + align:start position:0% +refresh your memories looking back at it +example one asked us to compute this + + align:start position:0% +example one asked us to compute this + + + align:start position:0% +example one asked us to compute this +anti-derivative and what I'd like to do + + align:start position:0% +anti-derivative and what I'd like to do + + + align:start position:0% +anti-derivative and what I'd like to do +now is to emphasize the fundamental + + align:start position:0% +now is to emphasize the fundamental + + + align:start position:0% +now is to emphasize the fundamental +theorem by wording this a different way + + align:start position:0% +theorem by wording this a different way + + + align:start position:0% +theorem by wording this a different way +what I want you to what I want to do now + + align:start position:0% +what I want you to what I want to do now + + + align:start position:0% +what I want you to what I want to do now +is to describe the plate R if its mass + + align:start position:0% +is to describe the plate R if its mass + + + align:start position:0% +is to describe the plate R if its mass +is given by what the double integral + + align:start position:0% +is given by what the double integral + + + align:start position:0% +is given by what the double integral +over the region R row of XY da a and + + align:start position:0% +over the region R row of XY da a and + + + align:start position:0% +over the region R row of XY da a and +that turns out to be integral from 0 to + + align:start position:0% +that turns out to be integral from 0 to + + + align:start position:0% +that turns out to be integral from 0 to +2 0 to x^2 x Cub y Dy DX what is the + + align:start position:0% +2 0 to x^2 x Cub y Dy DX what is the + + + align:start position:0% +2 0 to x^2 x Cub y Dy DX what is the +region R whose what is this region R if + + align:start position:0% +region R whose what is this region R if + + + align:start position:0% +region R whose what is this region R if +this is how its mass is given the first + + align:start position:0% +this is how its mass is given the first + + + align:start position:0% +this is how its mass is given the first +thing I want you to observe of course is + + align:start position:0% +thing I want you to observe of course is + + + align:start position:0% +thing I want you to observe of course is +that this part here is identified with + + align:start position:0% +that this part here is identified with + + + align:start position:0% +that this part here is identified with +the density part of the problem and that + + align:start position:0% +the density part of the problem and that + + + align:start position:0% +the density part of the problem and that +these limits of integration determine + + align:start position:0% +these limits of integration determine + + + align:start position:0% +these limits of integration determine +the region R for example what this says + + align:start position:0% +the region R for example what this says + + + align:start position:0% +the region R for example what this says +is if you hold x constant y varies from + + align:start position:0% +is if you hold x constant y varies from + + + align:start position:0% +is if you hold x constant y varies from +0 to + + align:start position:0% +0 to + + + align:start position:0% +0 to +x^2 let's see what that means if you + + align:start position:0% +x^2 let's see what that means if you + + + align:start position:0% +x^2 let's see what that means if you +hold x constant + + align:start position:0% +hold x constant + + + align:start position:0% +hold x constant +y varies from Z well yal 0 is the x axis + + align:start position:0% +y varies from Z well yal 0 is the x axis + + + align:start position:0% +y varies from Z well yal 0 is the x axis +to Y = x^2 that's this particular + + align:start position:0% +to Y = x^2 that's this particular + + + align:start position:0% +to Y = x^2 that's this particular +Parabola what this says is for a fixed + + align:start position:0% +Parabola what this says is for a fixed + + + align:start position:0% +Parabola what this says is for a fixed +value of x say xal + + align:start position:0% +value of x say xal + + + align:start position:0% +value of x say xal +X1 the to be in the region R you can be + + align:start position:0% +X1 the to be in the region R you can be + + + align:start position:0% +X1 the to be in the region R you can be +any place from the x axis along the + + align:start position:0% +any place from the x axis along the + + + align:start position:0% +any place from the x axis along the +strip up to Y = X12 so your strip is + + align:start position:0% +strip up to Y = X12 so your strip is + + + align:start position:0% +strip up to Y = X12 so your strip is +like this then we're told that in turn X + + align:start position:0% +like this then we're told that in turn X + + + align:start position:0% +like this then we're told that in turn X +can be chosen to be any place from 0 to + + align:start position:0% +can be chosen to be any place from 0 to + + + align:start position:0% +can be chosen to be any place from 0 to +two so now what we know is that this + + align:start position:0% +two so now what we know is that this + + + align:start position:0% +two so now what we know is that this +strip could have been chosen for any + + align:start position:0% +strip could have been chosen for any + + + align:start position:0% +strip could have been chosen for any +value of x between 0 and two and what + + align:start position:0% +value of x between 0 and two and what + + + align:start position:0% +value of x between 0 and two and what +that tells us therefore is that the + + align:start position:0% +that tells us therefore is that the + + + align:start position:0% +that tells us therefore is that the +shape of our region R is the curve + + align:start position:0% +shape of our region R is the curve + + + align:start position:0% +shape of our region R is the curve +that's of the region that's bounded + + align:start position:0% +that's of the region that's bounded + + + align:start position:0% +that's of the region that's bounded +above by the curve yal x s below by the + + align:start position:0% +above by the curve yal x s below by the + + + align:start position:0% +above by the curve yal x s below by the +X + + align:start position:0% +X + + + align:start position:0% +X +AIS and on the right by the line x = 2 + + align:start position:0% +AIS and on the right by the line x = 2 + + + align:start position:0% +AIS and on the right by the line x = 2 +this is our region R you see the region + + align:start position:0% +this is our region R you see the region + + + align:start position:0% +this is our region R you see the region +R is determined by the limits of + + align:start position:0% +R is determined by the limits of + + + align:start position:0% +R is determined by the limits of +integration and the density of R is + + align:start position:0% +integration and the density of R is + + + align:start position:0% +integration and the density of R is +given by row of XY = X Cub Y at the + + align:start position:0% +given by row of XY = X Cub Y at the + + + align:start position:0% +given by row of XY = X Cub Y at the +point x comma y + + align:start position:0% +point x comma y + + + align:start position:0% +point x comma y +okay by the way in we had mentioned + + align:start position:0% +okay by the way in we had mentioned + + + align:start position:0% +okay by the way in we had mentioned +before that why do you have to write + + align:start position:0% +before that why do you have to write + + + align:start position:0% +before that why do you have to write +dydx couldn't you have written DX Dy + + align:start position:0% +dydx couldn't you have written DX Dy + + + align:start position:0% +dydx couldn't you have written DX Dy +what I thought I'd like to do for for my + + align:start position:0% +what I thought I'd like to do for for my + + + align:start position:0% +what I thought I'd like to do for for my +next example for you is to show you how + + align:start position:0% +next example for you is to show you how + + + align:start position:0% +next example for you is to show you how +one inverts or changes the order of + + align:start position:0% +one inverts or changes the order of + + + align:start position:0% +one inverts or changes the order of +integration for example given the same + + align:start position:0% +integration for example given the same + + + align:start position:0% +integration for example given the same +integral the same region R suppose we + + align:start position:0% +integral the same region R suppose we + + + align:start position:0% +integral the same region R suppose we +now want to express the mass in the form + + align:start position:0% +now want to express the mass in the form + + + align:start position:0% +now want to express the mass in the form +double integral X Cub y DX Dy you see + + align:start position:0% +double integral X Cub y DX Dy you see + + + align:start position:0% +double integral X Cub y DX Dy you see +the region R is still the same as it was + + align:start position:0% +the region R is still the same as it was + + + align:start position:0% +the region R is still the same as it was +before but now you see what we want to + + align:start position:0% +before but now you see what we want to + + + align:start position:0% +before but now you see what we want to +do how would we read this this says + + align:start position:0% +do how would we read this this says + + + align:start position:0% +do how would we read this this says +we're integrating with respect to x x is + + align:start position:0% +we're integrating with respect to x x is + + + align:start position:0% +we're integrating with respect to x x is +varying so this says for a fixed value + + align:start position:0% +varying so this says for a fixed value + + + align:start position:0% +varying so this says for a fixed value +of y integrate this thing see for a + + align:start position:0% +of y integrate this thing see for a + + + align:start position:0% +of y integrate this thing see for a +fixed value of y integrate this + + align:start position:0% +fixed value of y integrate this + + + align:start position:0% +fixed value of y integrate this +evaluated between the appropriate limits + + align:start position:0% +evaluated between the appropriate limits + + + align:start position:0% +evaluated between the appropriate limits +of x uh in terms of Y and then integrate + + align:start position:0% +of x uh in terms of Y and then integrate + + + align:start position:0% +of x uh in terms of Y and then integrate +this with respect to Y well with says + + align:start position:0% +this with respect to Y well with says + + + align:start position:0% +this with respect to Y well with says +this let's pick a fixed value of y let's + + align:start position:0% +this let's pick a fixed value of y let's + + + align:start position:0% +this let's pick a fixed value of y let's +say yal y1 for that fixed value of y + + align:start position:0% +say yal y1 for that fixed value of y + + + align:start position:0% +say yal y1 for that fixed value of y +notice that the curve y = x^2 for X + + align:start position:0% +notice that the curve y = x^2 for X + + + align:start position:0% +notice that the curve y = x^2 for X +positive in inverted form has the form + + align:start position:0% +positive in inverted form has the form + + + align:start position:0% +positive in inverted form has the form +xal the otk of Y all right so for a + + align:start position:0% +xal the otk of Y all right so for a + + + align:start position:0% +xal the otk of Y all right so for a +fixed value of y notice that X varies + + align:start position:0% +fixed value of y notice that X varies + + + align:start position:0% +fixed value of y notice that X varies +from the square root of y1 up to x = 2 + + align:start position:0% +from the square root of y1 up to x = 2 + + + align:start position:0% +from the square root of y1 up to x = 2 +see X goes from theun of Y to 2 for a + + align:start position:0% +see X goes from theun of Y to 2 for a + + + align:start position:0% +see X goes from theun of Y to 2 for a +fixed value of y now where can y be see + + align:start position:0% +fixed value of y now where can y be see + + + align:start position:0% +fixed value of y now where can y be see +this is our limits here why to be in the + + align:start position:0% +this is our limits here why to be in the + + + align:start position:0% +this is our limits here why to be in the +region r y could have been chosen as low + + align:start position:0% +region r y could have been chosen as low + + + align:start position:0% +region r y could have been chosen as low +as this or as high as this in other + + align:start position:0% +as this or as high as this in other + + + align:start position:0% +as this or as high as this in other +words y varies continuously from0 to + + align:start position:0% +words y varies continuously from0 to + + + align:start position:0% +words y varies continuously from0 to +four and again because I don't want to + + align:start position:0% +four and again because I don't want to + + + align:start position:0% +four and again because I don't want to +have our lecture obscured by + + align:start position:0% +have our lecture obscured by + + + align:start position:0% +have our lecture obscured by +computational detail I simply urge you + + align:start position:0% +computational detail I simply urge you + + + align:start position:0% +computational detail I simply urge you +to on your own compute this double + + align:start position:0% +to on your own compute this double + + + align:start position:0% +to on your own compute this double +integral compute the double integral + + align:start position:0% +integral compute the double integral + + + align:start position:0% +integral compute the double integral +that we obtained in example number three + + align:start position:0% +that we obtained in example number three + + + align:start position:0% +that we obtained in example number three +and show that the answers are the same + + align:start position:0% +and show that the answers are the same + + + align:start position:0% +and show that the answers are the same +what I do want you to observe is how + + align:start position:0% +what I do want you to observe is how + + + align:start position:0% +what I do want you to observe is how +different the limits look in other words + + align:start position:0% +different the limits look in other words + + + align:start position:0% +different the limits look in other words +notice that in the other integral it was + + align:start position:0% +notice that in the other integral it was + + + align:start position:0% +notice that in the other integral it was +from 0 to two outside now it's from 0 to + + align:start position:0% +from 0 to two outside now it's from 0 to + + + align:start position:0% +from 0 to two outside now it's from 0 to +4 notice also on the inside integral it + + align:start position:0% +4 notice also on the inside integral it + + + align:start position:0% +4 notice also on the inside integral it +was from 0 to x^2 now it's from the + + align:start position:0% +was from 0 to x^2 now it's from the + + + align:start position:0% +was from 0 to x^2 now it's from the +square root of Y to 2 there is no + + align:start position:0% +square root of Y to 2 there is no + + + align:start position:0% +square root of Y to 2 there is no +mechanical way of doing this at least in + + align:start position:0% +mechanical way of doing this at least in + + + align:start position:0% +mechanical way of doing this at least in +the two-dimensional case we can see from + + align:start position:0% +the two-dimensional case we can see from + + + align:start position:0% +the two-dimensional case we can see from +a picture what's happening in the + + align:start position:0% +a picture what's happening in the + + + align:start position:0% +a picture what's happening in the +multi-dimensional case we have to resort + + align:start position:0% +multi-dimensional case we have to resort + + + align:start position:0% +multi-dimensional case we have to resort +to the theory of inverse functions and + + align:start position:0% +to the theory of inverse functions and + + + align:start position:0% +to the theory of inverse functions and +this becomes at best a very messy + + align:start position:0% +this becomes at best a very messy + + + align:start position:0% +this becomes at best a very messy +procedure of course the answer is if + + align:start position:0% +procedure of course the answer is if + + + align:start position:0% +procedure of course the answer is if +it's such a messy procedure why bother + + align:start position:0% +it's such a messy procedure why bother + + + align:start position:0% +it's such a messy procedure why bother +with it and so in terms of another + + align:start position:0% +with it and so in terms of another + + + align:start position:0% +with it and so in terms of another +example that I would like to show you + + align:start position:0% +example that I would like to show you + + + align:start position:0% +example that I would like to show you +let me give you an illustration in which + + align:start position:0% +let me give you an illustration in which + + + align:start position:0% +let me give you an illustration in which +it may be possible to find the required + + align:start position:0% +it may be possible to find the required + + + align:start position:0% +it may be possible to find the required +answer if we integrate in one order but + + align:start position:0% +answer if we integrate in one order but + + + align:start position:0% +answer if we integrate in one order but +not if we integrate with respect to the + + align:start position:0% +not if we integrate with respect to the + + + align:start position:0% +not if we integrate with respect to the +other order let me evaluate the double + + align:start position:0% +other order let me evaluate the double + + + align:start position:0% +other order let me evaluate the double +integral 0 to 2 x to 2 e y^2 Dy DX again + + align:start position:0% +integral 0 to 2 x to 2 e y^2 Dy DX again + + + align:start position:0% +integral 0 to 2 x to 2 e y^2 Dy DX again +let me see if I can at least write down + + align:start position:0% +let me see if I can at least write down + + + align:start position:0% +let me see if I can at least write down +what this thing means geometrically + + align:start position:0% +what this thing means geometrically + + + align:start position:0% +what this thing means geometrically +before I even begin notice that I can + + align:start position:0% +before I even begin notice that I can + + + align:start position:0% +before I even begin notice that I can +think of this as a plate R whose density + + align:start position:0% +think of this as a plate R whose density + + + align:start position:0% +think of this as a plate R whose density +at the point x comma Y is e to the y^2 + + align:start position:0% +at the point x comma Y is e to the y^2 + + + align:start position:0% +at the point x comma Y is e to the y^2 +and what is the shape of this plate for + + align:start position:0% +and what is the shape of this plate for + + + align:start position:0% +and what is the shape of this plate for +a fixed integrate with respect to Y + + align:start position:0% +a fixed integrate with respect to Y + + + align:start position:0% +a fixed integrate with respect to Y +first for a fixed value of for a fixed + + align:start position:0% +first for a fixed value of for a fixed + + + align:start position:0% +first for a fixed value of for a fixed +value of x y goes from yal X well that's + + align:start position:0% +value of x y goes from yal X well that's + + + align:start position:0% +value of x y goes from yal X well that's +this line here to Y = 2 that's this line + + align:start position:0% +this line here to Y = 2 that's this line + + + align:start position:0% +this line here to Y = 2 that's this line +here so for a fixed X Y varies + + align:start position:0% +here so for a fixed X Y varies + + + align:start position:0% +here so for a fixed X Y varies +continuously from here to here x can be + + align:start position:0% +continuously from here to here x can be + + + align:start position:0% +continuously from here to here x can be +any place from 0 to two that happens to + + align:start position:0% +any place from 0 to two that happens to + + + align:start position:0% +any place from 0 to two that happens to +be the point 2 comma 2 where the line + + align:start position:0% +be the point 2 comma 2 where the line + + + align:start position:0% +be the point 2 comma 2 where the line +and these two lines intersect so the + + align:start position:0% +and these two lines intersect so the + + + align:start position:0% +and these two lines intersect so the +region R is this rectangular region here + + align:start position:0% +region R is this rectangular region here + + + align:start position:0% +region R is this rectangular region here +okay this is our region R and what we're + + align:start position:0% +okay this is our region R and what we're + + + align:start position:0% +okay this is our region R and what we're +saying is find the mass of the region R + + align:start position:0% +saying is find the mass of the region R + + + align:start position:0% +saying is find the mass of the region R +if its density at the point x comma Y is + + align:start position:0% +if its density at the point x comma Y is + + + align:start position:0% +if its density at the point x comma Y is +e to y^2 + + align:start position:0% +e to y^2 + + + align:start position:0% +e to y^2 +now notice that this density exists even + + align:start position:0% +now notice that this density exists even + + + align:start position:0% +now notice that this density exists even +if I've never heard of the + + align:start position:0% +if I've never heard of the + + + align:start position:0% +if I've never heard of the +anti-derivative if however I elect to + + align:start position:0% +anti-derivative if however I elect to + + + align:start position:0% +anti-derivative if however I elect to +use the fundamental theorem and I say + + align:start position:0% +use the fundamental theorem and I say + + + align:start position:0% +use the fundamental theorem and I say +okay what I'll do is is I'll compute + + align:start position:0% +okay what I'll do is is I'll compute + + + align:start position:0% +okay what I'll do is is I'll compute +this notice I'm back to an old Bugaboo I + + align:start position:0% +this notice I'm back to an old Bugaboo I + + + align:start position:0% +this notice I'm back to an old Bugaboo I +don't know how to integrate e to the y^2 + + align:start position:0% +don't know how to integrate e to the y^2 + + + align:start position:0% +don't know how to integrate e to the y^2 +Dy other than by an approximation in + + align:start position:0% +Dy other than by an approximation in + + + align:start position:0% +Dy other than by an approximation in +terms of Elementary functions there is + + align:start position:0% +terms of Elementary functions there is + + + align:start position:0% +terms of Elementary functions there is +no function whose derivative respect to + + align:start position:0% +no function whose derivative respect to + + + align:start position:0% +no function whose derivative respect to +Y is e to the y^ 2 so what I do is I + + align:start position:0% +Y is e to the y^ 2 so what I do is I + + + align:start position:0% +Y is e to the y^ 2 so what I do is I +elect the change the order of + + align:start position:0% +elect the change the order of + + + align:start position:0% +elect the change the order of +integration why is that well because if + + align:start position:0% +integration why is that well because if + + + align:start position:0% +integration why is that well because if +I change the order of integration sure + + align:start position:0% +I change the order of integration sure + + + align:start position:0% +I change the order of integration sure +I'm integrating e to the y s but now + + align:start position:0% +I'm integrating e to the y s but now + + + align:start position:0% +I'm integrating e to the y s but now +with respect to X which means that e to + + align:start position:0% +with respect to X which means that e to + + + align:start position:0% +with respect to X which means that e to +the y^2 is a constant heck this is + + align:start position:0% +the y^2 is a constant heck this is + + + align:start position:0% +the y^2 is a constant heck this is +Trivial to integrate it's just going to + + align:start position:0% +Trivial to integrate it's just going to + + + align:start position:0% +Trivial to integrate it's just going to +be x * e to y^2 the problem is what if + + align:start position:0% +be x * e to y^2 the problem is what if + + + align:start position:0% +be x * e to y^2 the problem is what if +I'm going to change the order here I + + align:start position:0% +I'm going to change the order here I + + + align:start position:0% +I'm going to change the order here I +must make sure that I take care of the + + align:start position:0% +must make sure that I take care of the + + + align:start position:0% +must make sure that I take care of the +limits of integration accordingly now + + align:start position:0% +limits of integration accordingly now + + + align:start position:0% +limits of integration accordingly now +what this says is what I'm going to + + align:start position:0% +what this says is what I'm going to + + + align:start position:0% +what this says is what I'm going to +integrate respect to X first X is going + + align:start position:0% +integrate respect to X first X is going + + + align:start position:0% +integrate respect to X first X is going +to vary so I'm treating y as a constant + + align:start position:0% +to vary so I'm treating y as a constant + + + align:start position:0% +to vary so I'm treating y as a constant +for that constant value of y notice that + + align:start position:0% +for that constant value of y notice that + + + align:start position:0% +for that constant value of y notice that +the b in the region are for that + + align:start position:0% +the b in the region are for that + + + align:start position:0% +the b in the region are for that +constant value of y r x varies from what + + align:start position:0% +constant value of y r x varies from what + + + align:start position:0% +constant value of y r x varies from what +x varies from zero to the line yal X or + + align:start position:0% +x varies from zero to the line yal X or + + + align:start position:0% +x varies from zero to the line yal X or +accordingly xals y so for that fixed + + align:start position:0% +accordingly xals y so for that fixed + + + align:start position:0% +accordingly xals y so for that fixed +value of x for I'm sorry for that fixed + + align:start position:0% +value of x for I'm sorry for that fixed + + + align:start position:0% +value of x for I'm sorry for that fixed +value of y x varies from xal 0 to xal 1 + + align:start position:0% +value of y x varies from xal 0 to xal 1 + + + align:start position:0% +value of y x varies from xal 0 to xal 1 +Y and correspondingly Y can be chosen to + + align:start position:0% +Y and correspondingly Y can be chosen to + + + align:start position:0% +Y and correspondingly Y can be chosen to +be any fixed number between 0 and two + + align:start position:0% +be any fixed number between 0 and two + + + align:start position:0% +be any fixed number between 0 and two +and that gives me this particular double + + align:start position:0% +and that gives me this particular double + + + align:start position:0% +and that gives me this particular double +integral and by the way from this point + + align:start position:0% +integral and by the way from this point + + + align:start position:0% +integral and by the way from this point +on the rest is Child's Play Because when + + align:start position:0% +on the rest is Child's Play Because when + + + align:start position:0% +on the rest is Child's Play Because when +I integrate this you see this integrand + + align:start position:0% +I integrate this you see this integrand + + + align:start position:0% +I integrate this you see this integrand +is x e to y^ 2 when X is equal to Y this + + align:start position:0% +is x e to y^ 2 when X is equal to Y this + + + align:start position:0% +is x e to y^ 2 when X is equal to Y this +this becomes + + align:start position:0% +this becomes + + + align:start position:0% +this becomes +X when X is equal to Y this becomes y e + + align:start position:0% +X when X is equal to Y this becomes y e + + + align:start position:0% +X when X is equal to Y this becomes y e +to the y^2 when X is zero the lower + + align:start position:0% +to the y^2 when X is zero the lower + + + align:start position:0% +to the y^2 when X is zero the lower +limit drops out so what I want to + + align:start position:0% +limit drops out so what I want to + + + align:start position:0% +limit drops out so what I want to +integrate now is 0 to 2 y e to y^2 Dy + + align:start position:0% +integrate now is 0 to 2 y e to y^2 Dy + + + align:start position:0% +integrate now is 0 to 2 y e to y^2 Dy +but this is beautiful for me because the + + align:start position:0% +but this is beautiful for me because the + + + align:start position:0% +but this is beautiful for me because the +factor of Y in here is exactly what I + + align:start position:0% +factor of Y in here is exactly what I + + + align:start position:0% +factor of Y in here is exactly what I +need to be able to handle this in other + + align:start position:0% +need to be able to handle this in other + + + align:start position:0% +need to be able to handle this in other +words this is nothing more than2 e to + + align:start position:0% +words this is nothing more than2 e to + + + align:start position:0% +words this is nothing more than2 e to +the y^ 2 evaluated between 0 and 2 + + align:start position:0% +the y^ 2 evaluated between 0 and 2 + + + align:start position:0% +the y^ 2 evaluated between 0 and 2 +replacing y by 2 gives me 12 e to 4 + + align:start position:0% +replacing y by 2 gives me 12 e to 4 + + + align:start position:0% +replacing y by 2 gives me 12 e to 4 +replacing y by0 remember e the 0 is 1 + + align:start position:0% +replacing y by0 remember e the 0 is 1 + + + align:start position:0% +replacing y by0 remember e the 0 is 1 +gives me minus one2 because I'm + + align:start position:0% +gives me minus one2 because I'm + + + align:start position:0% +gives me minus one2 because I'm +subtracting the lower limit and in other + + align:start position:0% +subtracting the lower limit and in other + + + align:start position:0% +subtracting the lower limit and in other +words this the answer to evaluating this + + align:start position:0% +words this the answer to evaluating this + + + align:start position:0% +words this the answer to evaluating this +integral which was impossible to do in + + align:start position:0% +integral which was impossible to do in + + + align:start position:0% +integral which was impossible to do in +this form because of the fact that there + + align:start position:0% +this form because of the fact that there + + + align:start position:0% +this form because of the fact that there +was no Elementary function whose + + align:start position:0% +was no Elementary function whose + + + align:start position:0% +was no Elementary function whose +derivative is e y^2 turns out quite + + align:start position:0% +derivative is e y^2 turns out quite + + + align:start position:0% +derivative is e y^2 turns out quite +nicely to be given by e 4us 1 / 2 and to + + align:start position:0% +nicely to be given by e 4us 1 / 2 and to + + + align:start position:0% +nicely to be given by e 4us 1 / 2 and to +summarize today's lecture to show you + + align:start position:0% +summarize today's lecture to show you + + + align:start position:0% +summarize today's lecture to show you +what the fundamental theorem really + + align:start position:0% +what the fundamental theorem really + + + align:start position:0% +what the fundamental theorem really +means all we're saying is that we often + + align:start position:0% +means all we're saying is that we often + + + align:start position:0% +means all we're saying is that we often +compute the infinite double sum double + + align:start position:0% +compute the infinite double sum double + + + align:start position:0% +compute the infinite double sum double +integral r f of + + align:start position:0% +integral r f of + + + align:start position:0% +integral r f of +xyda + + align:start position:0% +xyda + + + align:start position:0% +xyda +by an appropriate iterated integral + + align:start position:0% +by an appropriate iterated integral + + + align:start position:0% +by an appropriate iterated integral +that's what we mean is what the + + align:start position:0% +that's what we mean is what the + + + align:start position:0% +that's what we mean is what the +anti-derivative integrating taking the + + align:start position:0% +anti-derivative integrating taking the + + + align:start position:0% +anti-derivative integrating taking the +anti-derivative successively iterated + + align:start position:0% +anti-derivative successively iterated + + + align:start position:0% +anti-derivative successively iterated +integral see iterated + + align:start position:0% +integral see iterated + + + align:start position:0% +integral see iterated +integral and + + align:start position:0% +integral and + + + align:start position:0% +integral and +conversely in other words the gist of + + align:start position:0% +conversely in other words the gist of + + + align:start position:0% +conversely in other words the gist of +this whole thing is is that we now have + + align:start position:0% +this whole thing is is that we now have + + + align:start position:0% +this whole thing is is that we now have +two entirely different topics that are + + align:start position:0% +two entirely different topics that are + + + align:start position:0% +two entirely different topics that are +related by a fantastic unifying thread + + align:start position:0% +related by a fantastic unifying thread + + + align:start position:0% +related by a fantastic unifying thread +that allows us to solve one of the + + align:start position:0% +that allows us to solve one of the + + + align:start position:0% +that allows us to solve one of the +problems in terms of the other and vice + + align:start position:0% +problems in terms of the other and vice + + + align:start position:0% +problems in terms of the other and vice +versa you see again the analogy being + + align:start position:0% +versa you see again the analogy being + + + align:start position:0% +versa you see again the analogy being +complete with what happened in the + + align:start position:0% +complete with what happened in the + + + align:start position:0% +complete with what happened in the +calculus of a single variable that we + + align:start position:0% +calculus of a single variable that we + + + align:start position:0% +calculus of a single variable that we +can evaluate double sums which was the + + align:start position:0% +can evaluate double sums which was the + + + align:start position:0% +can evaluate double sums which was the +aim of the previous lecture by means of + + align:start position:0% +aim of the previous lecture by means of + + + align:start position:0% +aim of the previous lecture by means of +an iterated integral we can evaluate + + align:start position:0% +an iterated integral we can evaluate + + + align:start position:0% +an iterated integral we can evaluate +iterated integrals sometimes by + + align:start position:0% +iterated integrals sometimes by + + + align:start position:0% +iterated integrals sometimes by +appropriately knowing how to find or by + + align:start position:0% +appropriately knowing how to find or by + + + align:start position:0% +appropriately knowing how to find or by +knowing how to find the limit of an + + align:start position:0% +knowing how to find the limit of an + + + align:start position:0% +knowing how to find the limit of an +appropriate uh double some and again we + + align:start position:0% +appropriate uh double some and again we + + + align:start position:0% +appropriate uh double some and again we +shall make use of this in the exercises + + align:start position:0% +shall make use of this in the exercises + + + align:start position:0% +shall make use of this in the exercises +we will go into this in more detail from + + align:start position:0% +we will go into this in more detail from + + + align:start position:0% +we will go into this in more detail from +other aspects and other points of view + + align:start position:0% +other aspects and other points of view + + + align:start position:0% +other aspects and other points of view +next time at any rate until next time + + align:start position:0% + + + + align:start position:0% + +goodbye funding for the publication of + + align:start position:0% +goodbye funding for the publication of + + + align:start position:0% +goodbye funding for the publication of +this video was provided by the Gabriella + + align:start position:0% +this video was provided by the Gabriella + + + align:start position:0% +this video was provided by the Gabriella +and Paul rosenbom + + align:start position:0% +and Paul rosenbom + + + align:start position:0% +and Paul rosenbom +foundation help ocw continue to provide + + align:start position:0% +foundation help ocw continue to provide + + + align:start position:0% +foundation help ocw continue to provide +free and open access to MIT courses by + + align:start position:0% +free and open access to MIT courses by + + + align:start position:0% +free and open access to MIT courses by +making a donation at ocw + + align:start position:0% +making a donation at ocw + + + align:start position:0% +making a donation at ocw +mit.edu + + align:start position:0% + + + + align:start position:0% + +donate \ No newline at end of file diff --git a/2tGYGprLuNs.txt b/2tGYGprLuNs.txt new file mode 100644 index 0000000000000000000000000000000000000000..8e7a37826785ba5d6918deee407caa9b5ec7c40c --- /dev/null +++ b/2tGYGprLuNs.txt @@ -0,0 +1,475 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +compositions of gallium and indium and + + align:start position:0% +compositions of gallium and indium and + + + align:start position:0% +compositions of gallium and indium and +at what temperature they will melt + + align:start position:0% +at what temperature they will melt + + + align:start position:0% +at what temperature they will melt +first we start with solid engine + + align:start position:0% +first we start with solid engine + + + align:start position:0% +first we start with solid engine +we put a small piece of solid and + + align:start position:0% +we put a small piece of solid and + + + align:start position:0% +we put a small piece of solid and +gallium and we just shake it + + align:start position:0% +gallium and we just shake it + + + align:start position:0% +gallium and we just shake it +for some time maybe around one or two + + align:start position:0% +for some time maybe around one or two + + + align:start position:0% +for some time maybe around one or two +minutes + + align:start position:0% + + + + align:start position:0% + +and then what it is a liquid alloy why + + align:start position:0% +and then what it is a liquid alloy why + + + align:start position:0% +and then what it is a liquid alloy why +does this happen + + align:start position:0% +does this happen + + + align:start position:0% +does this happen +this is the phase diagram of gallium + + align:start position:0% +this is the phase diagram of gallium + + + align:start position:0% +this is the phase diagram of gallium +industrum as you can see gallium melts + + align:start position:0% +industrum as you can see gallium melts + + + align:start position:0% +industrum as you can see gallium melts +around 30 degrees Celsius which is close + + align:start position:0% +around 30 degrees Celsius which is close + + + align:start position:0% +around 30 degrees Celsius which is close +to room temperature as India melts + + align:start position:0% +to room temperature as India melts + + + align:start position:0% +to room temperature as India melts +around 157 degrees Celsius + + align:start position:0% + + + + align:start position:0% + +we have prepared four different + + align:start position:0% +we have prepared four different + + + align:start position:0% +we have prepared four different +compositions a is pure gallium and it + + align:start position:0% +compositions a is pure gallium and it + + + align:start position:0% +compositions a is pure gallium and it +all melts at room temperature but not + + align:start position:0% +all melts at room temperature but not + + + align:start position:0% +all melts at room temperature but not +quite + + align:start position:0% +quite + + + align:start position:0% +quite +um + + align:start position:0% +um + + + align:start position:0% +um +mixture B which is a composition + + align:start position:0% +mixture B which is a composition + + + align:start position:0% +mixture B which is a composition +that's close to the ejected composition + + align:start position:0% +that's close to the ejected composition + + + align:start position:0% +that's close to the ejected composition +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +it's a liquid-like material + + align:start position:0% + + + + align:start position:0% + +where you can see when we shake it when + + align:start position:0% +where you can see when we shake it when + + + align:start position:0% +where you can see when we shake it when +we shake the cuet you can see the + + align:start position:0% +we shake the cuet you can see the + + + align:start position:0% +we shake the cuet you can see the +movement and see similarly it also + + align:start position:0% +movement and see similarly it also + + + align:start position:0% +movement and see similarly it also +detected but at a higher temperature so + + align:start position:0% +detected but at a higher temperature so + + + align:start position:0% +detected but at a higher temperature so +it's uh it moves less + + align:start position:0% + + + + align:start position:0% + +whereas D is as we saw before solid + + align:start position:0% +whereas D is as we saw before solid + + + align:start position:0% +whereas D is as we saw before solid +indium which melts at 150 degrees + + align:start position:0% +indium which melts at 150 degrees + + + align:start position:0% +indium which melts at 150 degrees +Celsius + + align:start position:0% +Celsius + + + align:start position:0% +Celsius +um so it's it's solid at around 30 + + align:start position:0% +um so it's it's solid at around 30 + + + align:start position:0% +um so it's it's solid at around 30 +ounces + + align:start position:0% + + + + align:start position:0% + +take another look at + + align:start position:0% +take another look at + + + align:start position:0% +take another look at +composition B which clearly is a liquid + + align:start position:0% +composition B which clearly is a liquid + + + align:start position:0% +composition B which clearly is a liquid +now let's dynamically create a eutectic + + align:start position:0% +now let's dynamically create a eutectic + + + align:start position:0% +now let's dynamically create a eutectic +alloy so what we'll do is + + align:start position:0% +alloy so what we'll do is + + + align:start position:0% +alloy so what we'll do is +for this we start with + + align:start position:0% +for this we start with + + + align:start position:0% +for this we start with +almost room to regalium slightly higher + + align:start position:0% +almost room to regalium slightly higher + + + align:start position:0% +almost room to regalium slightly higher +around 30 degree Celsius + + align:start position:0% +around 30 degree Celsius + + + align:start position:0% +around 30 degree Celsius +and we put a piece of indium in there + + align:start position:0% +and we put a piece of indium in there + + + align:start position:0% +and we put a piece of indium in there +and we will see how they mix + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +and we will gently mix it in the next + + align:start position:0% +and we will gently mix it in the next + + + align:start position:0% +and we will gently mix it in the next +minute or so + + align:start position:0% + + + + align:start position:0% + +as you mix it the soft piece of indium + + align:start position:0% +as you mix it the soft piece of indium + + + align:start position:0% +as you mix it the soft piece of indium +that actually melts at a much higher + + align:start position:0% +that actually melts at a much higher + + + align:start position:0% +that actually melts at a much higher +temperature + + align:start position:0% +temperature + + + align:start position:0% +temperature +slow melts uh because the + + align:start position:0% +slow melts uh because the + + + align:start position:0% +slow melts uh because the +we're going down the composition slope + + align:start position:0% +we're going down the composition slope + + + align:start position:0% +we're going down the composition slope +into closer to your tactic which melts + + align:start position:0% +into closer to your tactic which melts + + + align:start position:0% +into closer to your tactic which melts +at room temperature + + align:start position:0% +at room temperature + + + align:start position:0% +at room temperature +this is a very cool way to create a + + align:start position:0% +this is a very cool way to create a + + + align:start position:0% +this is a very cool way to create a +eutectic Alloy at temperature + + align:start position:0% +eutectic Alloy at temperature + + + align:start position:0% +eutectic Alloy at temperature +um + + align:start position:0% +um + + + align:start position:0% +um +and also + + align:start position:0% +and also + + + align:start position:0% +and also +trying to understand the phase diagram + + align:start position:0% +trying to understand the phase diagram + + + align:start position:0% +trying to understand the phase diagram +of + + align:start position:0% +of + + + align:start position:0% +of +this system \ No newline at end of file diff --git a/2xONWF0XzOI.txt b/2xONWF0XzOI.txt new file mode 100644 index 0000000000000000000000000000000000000000..54d0b1fcaa1fa9df1b81f1ea787b519048d6bc87 --- /dev/null +++ b/2xONWF0XzOI.txt @@ -0,0 +1,13624 @@ +align:start position:0% + +the following content is provided by mit + + align:start position:0% +the following content is provided by mit + + + align:start position:0% +the following content is provided by mit +opencourseware under a creative commons + + align:start position:0% +opencourseware under a creative commons + + + align:start position:0% +opencourseware under a creative commons +license + + align:start position:0% +license + + + align:start position:0% +license +additional information about our license + + align:start position:0% +additional information about our license + + + align:start position:0% +additional information about our license +and mit opencourseware in general is + + align:start position:0% +and mit opencourseware in general is + + + align:start position:0% +and mit opencourseware in general is +available at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +ready + + align:start position:0% +ready + + + align:start position:0% +ready +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +welcome to the + + align:start position:0% +welcome to the + + + align:start position:0% +welcome to the +the third phase of our omics discussion + + align:start position:0% +the third phase of our omics discussion + + + align:start position:0% +the third phase of our omics discussion +someone pointed out that i should point + + align:start position:0% +someone pointed out that i should point + + + align:start position:0% +someone pointed out that i should point +out the shirts of omics not comics + + align:start position:0% + + + + align:start position:0% + +so we've covered genomics and last time + + align:start position:0% +so we've covered genomics and last time + + + align:start position:0% +so we've covered genomics and last time +transcriptomics and today we introduced + + align:start position:0% +transcriptomics and today we introduced + + + align:start position:0% +transcriptomics and today we introduced +a very important + + align:start position:0% +a very important + + + align:start position:0% +a very important +all-inclusive subject of proteomics + + align:start position:0% +all-inclusive subject of proteomics + + + align:start position:0% +all-inclusive subject of proteomics +we'll connect it to last week's + + align:start position:0% +we'll connect it to last week's + + + align:start position:0% +we'll connect it to last week's +through the vehicle of focusing on + + align:start position:0% +through the vehicle of focusing on + + + align:start position:0% +through the vehicle of focusing on +motifs + + align:start position:0% +motifs + + + align:start position:0% +motifs +that are involved in protein + + align:start position:0% +that are involved in protein + + + align:start position:0% +that are involved in protein +interactions with the two nucleic acid + + align:start position:0% +interactions with the two nucleic acid + + + align:start position:0% +interactions with the two nucleic acid +macromolecules + + align:start position:0% +macromolecules + + + align:start position:0% +macromolecules +so we're gonna we're gonna be covering + + align:start position:0% +so we're gonna we're gonna be covering + + + align:start position:0% +so we're gonna we're gonna be covering +just as we + + align:start position:0% +just as we + + + align:start position:0% +just as we +introduced rna omics with + + align:start position:0% +introduced rna omics with + + + align:start position:0% +introduced rna omics with +rna structure we're gonna spend this + + align:start position:0% +rna structure we're gonna spend this + + + align:start position:0% +rna structure we're gonna spend this +entire class talking about protein + + align:start position:0% +entire class talking about protein + + + align:start position:0% +entire class talking about protein +three-dimensional structure + + align:start position:0% +three-dimensional structure + + + align:start position:0% +three-dimensional structure +how you get at it experimentally and + + align:start position:0% +how you get at it experimentally and + + + align:start position:0% +how you get at it experimentally and +computationally and its implications for + + align:start position:0% +computationally and its implications for + + + align:start position:0% +computationally and its implications for +the binding of small molecules such as + + align:start position:0% +the binding of small molecules such as + + + align:start position:0% +the binding of small molecules such as +drugs + + align:start position:0% +drugs + + + align:start position:0% +drugs +we will in short order get to the scary + + align:start position:0% +we will in short order get to the scary + + + align:start position:0% +we will in short order get to the scary +pumpkin like molecule + + align:start position:0% +pumpkin like molecule + + + align:start position:0% +pumpkin like molecule +so the connection to last + + align:start position:0% + + + + align:start position:0% + +week was this + + align:start position:0% +week was this + + + align:start position:0% +week was this +this + + align:start position:0% + + + + align:start position:0% + +diagram showing palindromicity in three + + align:start position:0% +diagram showing palindromicity in three + + + align:start position:0% +diagram showing palindromicity in three +cases and a direct repeat + + align:start position:0% +cases and a direct repeat + + + align:start position:0% +cases and a direct repeat +in the fourth case + + align:start position:0% +in the fourth case + + + align:start position:0% +in the fourth case +and i offered that this might reflect + + align:start position:0% +and i offered that this might reflect + + + align:start position:0% +and i offered that this might reflect +the symmetry of the proteins of the + + align:start position:0% +the symmetry of the proteins of the + + + align:start position:0% +the symmetry of the proteins of the +three-dimensional structure of the + + align:start position:0% +three-dimensional structure of the + + + align:start position:0% +three-dimensional structure of the +proteins + + align:start position:0% +proteins + + + align:start position:0% +proteins +and the three-dimensional structure of + + align:start position:0% +and the three-dimensional structure of + + + align:start position:0% +and the three-dimensional structure of +the nucleic acid and the symmetry + + align:start position:0% +the nucleic acid and the symmetry + + + align:start position:0% +the nucleic acid and the symmetry +elements would align now in order to + + align:start position:0% +elements would align now in order to + + + align:start position:0% +elements would align now in order to +introduce these symmetry elements and + + align:start position:0% +introduce these symmetry elements and + + + align:start position:0% +introduce these symmetry elements and +the possibility of having codes that you + + align:start position:0% +the possibility of having codes that you + + + align:start position:0% +the possibility of having codes that you +can at least program + + align:start position:0% +can at least program + + + align:start position:0% +can at least program +even if they may have been tinkered + + align:start position:0% +even if they may have been tinkered + + + align:start position:0% +even if they may have been tinkered +about during + + align:start position:0% +about during + + + align:start position:0% +about during +evolution + + align:start position:0% +evolution + + + align:start position:0% +evolution +question is to what extent can we get + + align:start position:0% +question is to what extent can we get + + + align:start position:0% +question is to what extent can we get +our hands on these kind of protein and + + align:start position:0% +our hands on these kind of protein and + + + align:start position:0% +our hands on these kind of protein and +nucleic acid motifs that interact + + align:start position:0% +nucleic acid motifs that interact + + + align:start position:0% +nucleic acid motifs that interact +in order to to get at this + + align:start position:0% +in order to to get at this + + + align:start position:0% +in order to to get at this +issue of where there is a code and i + + align:start position:0% +issue of where there is a code and i + + + align:start position:0% +issue of where there is a code and i +just take this + + align:start position:0% +just take this + + + align:start position:0% +just take this +as one of the ways of dealing with the + + align:start position:0% +as one of the ways of dealing with the + + + align:start position:0% +as one of the ways of dealing with the +incredible complexity of proteins just + + align:start position:0% +incredible complexity of proteins just + + + align:start position:0% +incredible complexity of proteins just +give this a theme that connects it to + + align:start position:0% +give this a theme that connects it to + + + align:start position:0% +give this a theme that connects it to +the last class + + align:start position:0% +the last class + + + align:start position:0% +the last class +uh and connects i think to many of the + + align:start position:0% +uh and connects i think to many of the + + + align:start position:0% +uh and connects i think to many of the +sentiments of people in this sort of + + align:start position:0% +sentiments of people in this sort of + + + align:start position:0% +sentiments of people in this sort of +audience uh interested at computational + + align:start position:0% +audience uh interested at computational + + + align:start position:0% +audience uh interested at computational +biology is is ways of having simple + + align:start position:0% +biology is is ways of having simple + + + align:start position:0% +biology is is ways of having simple +codes + + align:start position:0% +codes + + + align:start position:0% +codes +and of course the way of one way of + + align:start position:0% +and of course the way of one way of + + + align:start position:0% +and of course the way of one way of +breaking up proteins and thinking about + + align:start position:0% +breaking up proteins and thinking about + + + align:start position:0% +breaking up proteins and thinking about +them is these abc's the alpha helix the + + align:start position:0% +them is these abc's the alpha helix the + + + align:start position:0% +them is these abc's the alpha helix the +beta sheet and the coil + + align:start position:0% +beta sheet and the coil + + + align:start position:0% +beta sheet and the coil +each of these uh can be characterized by + + align:start position:0% +each of these uh can be characterized by + + + align:start position:0% +each of these uh can be characterized by +the hydrogen bonds that hold it together + + align:start position:0% +the hydrogen bonds that hold it together + + + align:start position:0% +the hydrogen bonds that hold it together +the weak bonds between the the + + align:start position:0% +the weak bonds between the the + + + align:start position:0% +the weak bonds between the the +hydrogens + + align:start position:0% +hydrogens + + + align:start position:0% +hydrogens +the nitrogens and the oxygens + + align:start position:0% +the nitrogens and the oxygens + + + align:start position:0% +the nitrogens and the oxygens +and the alpha helix these are all kept + + align:start position:0% +and the alpha helix these are all kept + + + align:start position:0% +and the alpha helix these are all kept +within the helix uh with a repeat of 3.6 + + align:start position:0% +within the helix uh with a repeat of 3.6 + + + align:start position:0% +within the helix uh with a repeat of 3.6 +residues per turn + + align:start position:0% +residues per turn + + + align:start position:0% +residues per turn +in the beta sheet they tend to have + + align:start position:0% +in the beta sheet they tend to have + + + align:start position:0% +in the beta sheet they tend to have +the longer straighter + + align:start position:0% +the longer straighter + + + align:start position:0% +the longer straighter +chains whereas there are unpaired + + align:start position:0% +chains whereas there are unpaired + + + align:start position:0% +chains whereas there are unpaired +hydrogen bonds inevitably until you form + + align:start position:0% +hydrogen bonds inevitably until you form + + + align:start position:0% +hydrogen bonds inevitably until you form +enough chains to form a cyclic structure + + align:start position:0% +enough chains to form a cyclic structure + + + align:start position:0% +enough chains to form a cyclic structure +while the alpha helix is immediately + + align:start position:0% +while the alpha helix is immediately + + + align:start position:0% +while the alpha helix is immediately +helical + + align:start position:0% + + + + align:start position:0% + +there are many different types of coils + + align:start position:0% +there are many different types of coils + + + align:start position:0% +there are many different types of coils +that's a catch-all phrase that includes + + align:start position:0% +that's a catch-all phrase that includes + + + align:start position:0% +that's a catch-all phrase that includes +everything except alpha and beta but a + + align:start position:0% +everything except alpha and beta but a + + + align:start position:0% +everything except alpha and beta but a +particularly well formed + + align:start position:0% +particularly well formed + + + align:start position:0% +particularly well formed +type of coil which has its own + + align:start position:0% +type of coil which has its own + + + align:start position:0% +type of coil which has its own +nomenclature and and parameters is the + + align:start position:0% +nomenclature and and parameters is the + + + align:start position:0% +nomenclature and and parameters is the +turn and the turn is illustrated here at + + align:start position:0% +turn and the turn is illustrated here at + + + align:start position:0% +turn and the turn is illustrated here at +the end of of a beta sheet uh it a beta + + align:start position:0% +the end of of a beta sheet uh it a beta + + + align:start position:0% +the end of of a beta sheet uh it a beta +sheet basically is going in on the lower + + align:start position:0% +sheet basically is going in on the lower + + + align:start position:0% +sheet basically is going in on the lower +right hand corner in the direction of + + align:start position:0% +right hand corner in the direction of + + + align:start position:0% +right hand corner in the direction of +the arrow the arrows typically point + + align:start position:0% +the arrow the arrows typically point + + + align:start position:0% +the arrow the arrows typically point +from the n-terminus to the c-terminus uh + + align:start position:0% +from the n-terminus to the c-terminus uh + + + align:start position:0% +from the n-terminus to the c-terminus uh +just as in nucleic acids was from five + + align:start position:0% +just as in nucleic acids was from five + + + align:start position:0% +just as in nucleic acids was from five +prime to three prime and here it goes in + + align:start position:0% +prime to three prime and here it goes in + + + align:start position:0% +prime to three prime and here it goes in +the arrow turns around very tightly and + + align:start position:0% +the arrow turns around very tightly and + + + align:start position:0% +the arrow turns around very tightly and +goes back out again + + align:start position:0% +goes back out again + + + align:start position:0% +goes back out again +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now how can we use these basic motifs + + align:start position:0% +now how can we use these basic motifs + + + align:start position:0% +now how can we use these basic motifs +these are the smallest meaningful units + + align:start position:0% +these are the smallest meaningful units + + + align:start position:0% +these are the smallest meaningful units +of protein + + align:start position:0% +of protein + + + align:start position:0% +of protein +three-dimensional structure how can we + + align:start position:0% +three-dimensional structure how can we + + + align:start position:0% +three-dimensional structure how can we +use these to recognize other + + align:start position:0% +use these to recognize other + + + align:start position:0% +use these to recognize other +macromolecules other proteins and + + align:start position:0% +macromolecules other proteins and + + + align:start position:0% +macromolecules other proteins and +nucleic acids + + align:start position:0% +nucleic acids + + + align:start position:0% +nucleic acids +so let's connect this to the motifs of + + align:start position:0% +so let's connect this to the motifs of + + + align:start position:0% +so let's connect this to the motifs of +last class we had these + + align:start position:0% +last class we had these + + + align:start position:0% +last class we had these +motifs that we could find weight + + align:start position:0% +motifs that we could find weight + + + align:start position:0% +motifs that we could find weight +matrices for them by aligning lots of + + align:start position:0% +matrices for them by aligning lots of + + + align:start position:0% +matrices for them by aligning lots of +sequences now instead of aligning + + align:start position:0% +sequences now instead of aligning + + + align:start position:0% +sequences now instead of aligning +sequences let's see what we can do by + + align:start position:0% +sequences let's see what we can do by + + + align:start position:0% +sequences let's see what we can do by +mutating + + align:start position:0% +mutating + + + align:start position:0% +mutating +both the protein part and the nucleic + + align:start position:0% +both the protein part and the nucleic + + + align:start position:0% +both the protein part and the nucleic +acid part + + align:start position:0% +acid part + + + align:start position:0% +acid part +and in order to do this just as as an + + align:start position:0% +and in order to do this just as as an + + + align:start position:0% +and in order to do this just as as an +illustration let's say we have three + + align:start position:0% +illustration let's say we have three + + + align:start position:0% +illustration let's say we have three +zinc fingers this is a real human and + + align:start position:0% +zinc fingers this is a real human and + + + align:start position:0% +zinc fingers this is a real human and +mouse + + align:start position:0% +mouse + + + align:start position:0% +mouse +dna binding protein + + align:start position:0% + + + + align:start position:0% + +with three zinc fingers in a row so this + + align:start position:0% +with three zinc fingers in a row so this + + + align:start position:0% +with three zinc fingers in a row so this +is an example of the direct repeat or + + align:start position:0% +is an example of the direct repeat or + + + align:start position:0% +is an example of the direct repeat or +tandem repeat type of symmetry remember + + align:start position:0% +tandem repeat type of symmetry remember + + + align:start position:0% +tandem repeat type of symmetry remember +there's a direct repeat and the inverted + + align:start position:0% +there's a direct repeat and the inverted + + + align:start position:0% +there's a direct repeat and the inverted +repeat + + align:start position:0% +repeat + + + align:start position:0% +repeat +and in this 10 repeat let's anchor the + + align:start position:0% +and in this 10 repeat let's anchor the + + + align:start position:0% +and in this 10 repeat let's anchor the +two ends and change the middle make + + align:start position:0% +two ends and change the middle make + + + align:start position:0% +two ends and change the middle make +every possible peptide sequence in the + + align:start position:0% +every possible peptide sequence in the + + + align:start position:0% +every possible peptide sequence in the +middle or or randomly sample the vast of + + align:start position:0% +middle or or randomly sample the vast of + + + align:start position:0% +middle or or randomly sample the vast of +space that might occur in changing uh + + align:start position:0% +space that might occur in changing uh + + + align:start position:0% +space that might occur in changing uh +a few say six or more key amino acids + + align:start position:0% +a few say six or more key amino acids + + + align:start position:0% +a few say six or more key amino acids +and then we know from the the + + align:start position:0% +and then we know from the the + + + align:start position:0% +and then we know from the the +three-dimensional structure that it + + align:start position:0% +three-dimensional structure that it + + + align:start position:0% +three-dimensional structure that it +interacts mainly with the middle three + + align:start position:0% +interacts mainly with the middle three + + + align:start position:0% +interacts mainly with the middle three +nucleotides so let's change those middle + + align:start position:0% +nucleotides so let's change those middle + + + align:start position:0% +nucleotides so let's change those middle +three nucleotides to every possible + + align:start position:0% +three nucleotides to every possible + + + align:start position:0% +three nucleotides to every possible +trinucleotide sequence + + align:start position:0% +trinucleotide sequence + + + align:start position:0% +trinucleotide sequence +and see + + align:start position:0% +and see + + + align:start position:0% +and see +quantitatively how much that + + align:start position:0% +quantitatively how much that + + + align:start position:0% +quantitatively how much that +the different sequences in the protein + + align:start position:0% +the different sequences in the protein + + + align:start position:0% +the different sequences in the protein +affect the different sequences in the + + align:start position:0% +affect the different sequences in the + + + align:start position:0% +affect the different sequences in the +nucleic acid + + align:start position:0% +nucleic acid + + + align:start position:0% +nucleic acid +so this is not going to be by staring at + + align:start position:0% +so this is not going to be by staring at + + + align:start position:0% +so this is not going to be by staring at +long sequence alignments where we're + + align:start position:0% +long sequence alignments where we're + + + align:start position:0% +long sequence alignments where we're +going to get the weight matrices we can + + align:start position:0% +going to get the weight matrices we can + + + align:start position:0% +going to get the weight matrices we can +get them by actual experimental measures + + align:start position:0% +get them by actual experimental measures + + + align:start position:0% +get them by actual experimental measures +of the binding + + align:start position:0% +of the binding + + + align:start position:0% +of the binding +in vitro + + align:start position:0% +in vitro + + + align:start position:0% +in vitro +and so what happens when you do this + + align:start position:0% +and so what happens when you do this + + + align:start position:0% +and so what happens when you do this +exercise the wild type now this the wild + + align:start position:0% +exercise the wild type now this the wild + + + align:start position:0% +exercise the wild type now this the wild +type sequence is something + + align:start position:0% +type sequence is something + + + align:start position:0% +type sequence is something +that + + align:start position:0% +that + + + align:start position:0% +that +may want to recognize a family of + + align:start position:0% +may want to recognize a family of + + + align:start position:0% +may want to recognize a family of +sequences we don't know exactly what the + + align:start position:0% +sequences we don't know exactly what the + + + align:start position:0% +sequences we don't know exactly what the +wild type sequences for this particular + + align:start position:0% +wild type sequences for this particular + + + align:start position:0% +wild type sequences for this particular +dna binding protein this thing finger + + align:start position:0% +dna binding protein this thing finger + + + align:start position:0% +dna binding protein this thing finger +from human analysis + + align:start position:0% +from human analysis + + + align:start position:0% +from human analysis +but the sequence of the business in the + + align:start position:0% +but the sequence of the business in the + + + align:start position:0% +but the sequence of the business in the +amino acid sequence of that recognition + + align:start position:0% +amino acid sequence of that recognition + + + align:start position:0% +amino acid sequence of that recognition +alpha helix that's binding into the + + align:start position:0% +alpha helix that's binding into the + + + align:start position:0% +alpha helix that's binding into the +major group of dna + + align:start position:0% +major group of dna + + + align:start position:0% +major group of dna +is shown in the upper left rsdh ltt and + + align:start position:0% +is shown in the upper left rsdh ltt and + + + align:start position:0% +is shown in the upper left rsdh ltt and +the sequence that it mainly binds to + + align:start position:0% +the sequence that it mainly binds to + + + align:start position:0% +the sequence that it mainly binds to +remember this is a weight matrix is not + + align:start position:0% +remember this is a weight matrix is not + + + align:start position:0% +remember this is a weight matrix is not +a consensus sequence this tgg + + align:start position:0% +a consensus sequence this tgg + + + align:start position:0% +a consensus sequence this tgg +it obviously recognizes a variety of + + align:start position:0% +it obviously recognizes a variety of + + + align:start position:0% +it obviously recognizes a variety of +other sequences and remember there's + + align:start position:0% +other sequences and remember there's + + + align:start position:0% +other sequences and remember there's +there's about three nucleotides on + + align:start position:0% +there's about three nucleotides on + + + align:start position:0% +there's about three nucleotides on +either side of it that the other two + + align:start position:0% +either side of it that the other two + + + align:start position:0% +either side of it that the other two +zinc fingers bind to + + align:start position:0% +zinc fingers bind to + + + align:start position:0% +zinc fingers bind to +when you + + align:start position:0% +when you + + + align:start position:0% +when you +try all 64 possible trinucleotides + + align:start position:0% +try all 64 possible trinucleotides + + + align:start position:0% +try all 64 possible trinucleotides +remember from the genetic code this is + + align:start position:0% +remember from the genetic code this is + + + align:start position:0% +remember from the genetic code this is +pure coincidence these are triplets the + + align:start position:0% +pure coincidence these are triplets the + + + align:start position:0% +pure coincidence these are triplets the +same as the genetic code it just happens + + align:start position:0% +same as the genetic code it just happens + + + align:start position:0% +same as the genetic code it just happens +to be the amount of the chunk of dna + + align:start position:0% +to be the amount of the chunk of dna + + + align:start position:0% +to be the amount of the chunk of dna +that a zinc finger will cover + + align:start position:0% +that a zinc finger will cover + + + align:start position:0% +that a zinc finger will cover +but but it's not coincidence the four to + + align:start position:0% +but but it's not coincidence the four to + + + align:start position:0% +but but it's not coincidence the four to +the third is still 64 which is like the + + align:start position:0% +the third is still 64 which is like the + + + align:start position:0% +the third is still 64 which is like the +genetic code and if you run through all + + align:start position:0% +genetic code and if you run through all + + + align:start position:0% +genetic code and if you run through all +all possible + + align:start position:0% +all possible + + + align:start position:0% +all possible +nucleotide sequences for this wild type + + align:start position:0% +nucleotide sequences for this wild type + + + align:start position:0% +nucleotide sequences for this wild type +you find the winner is tgg + + align:start position:0% +you find the winner is tgg + + + align:start position:0% +you find the winner is tgg +and it has that particular binding + + align:start position:0% +and it has that particular binding + + + align:start position:0% +and it has that particular binding +constant the binding constant is + + align:start position:0% +constant the binding constant is + + + align:start position:0% +constant the binding constant is +measured in in the + + align:start position:0% +measured in in the + + + align:start position:0% +measured in in the +the molarity roughly where you get half + + align:start position:0% +the molarity roughly where you get half + + + align:start position:0% +the molarity roughly where you get half +maximal uh for equilibrium binding + + align:start position:0% +maximal uh for equilibrium binding + + + align:start position:0% +maximal uh for equilibrium binding +that's 10 to the minus ninth moles per + + align:start position:0% +that's 10 to the minus ninth moles per + + + align:start position:0% +that's 10 to the minus ninth moles per +liter + + align:start position:0% +liter + + + align:start position:0% +liter +you can now mutagenize the peptide + + align:start position:0% +you can now mutagenize the peptide + + + align:start position:0% +you can now mutagenize the peptide +and select for peptides that bind to gcc + + align:start position:0% +and select for peptides that bind to gcc + + + align:start position:0% +and select for peptides that bind to gcc +remember the flanks are kept constant + + align:start position:0% +remember the flanks are kept constant + + + align:start position:0% +remember the flanks are kept constant +you get two peptides both bind to the + + align:start position:0% +you get two peptides both bind to the + + + align:start position:0% +you get two peptides both bind to the +gcc + + align:start position:0% +gcc + + + align:start position:0% +gcc +they both give waitress vapencies very + + align:start position:0% +they both give waitress vapencies very + + + align:start position:0% +they both give waitress vapencies very +similar to this + + align:start position:0% +similar to this + + + align:start position:0% +similar to this +um with so with very these are very high + + align:start position:0% +um with so with very these are very high + + + align:start position:0% +um with so with very these are very high +affinity binding constants just like + + align:start position:0% +affinity binding constants just like + + + align:start position:0% +affinity binding constants just like +with wild type + + align:start position:0% +with wild type + + + align:start position:0% +with wild type +essentially engineered + + align:start position:0% +essentially engineered + + + align:start position:0% +essentially engineered +by selection a new specificity + + align:start position:0% + + + + align:start position:0% + +and two different ways of getting it + + align:start position:0% +and two different ways of getting it + + + align:start position:0% +and two different ways of getting it +if you now go for something radically + + align:start position:0% +if you now go for something radically + + + align:start position:0% +if you now go for something radically +different now no gc the first one was a + + align:start position:0% +different now no gc the first one was a + + + align:start position:0% +different now no gc the first one was a +high gc the second was pure gc and then + + align:start position:0% +high gc the second was pure gc and then + + + align:start position:0% +high gc the second was pure gc and then +the third one is pure a t + + align:start position:0% +the third one is pure a t + + + align:start position:0% +the third one is pure a t +and you get another c of another peptide + + align:start position:0% +and you get another c of another peptide + + + align:start position:0% +and you get another c of another peptide +sequence that binds to that and you get + + align:start position:0% +sequence that binds to that and you get + + + align:start position:0% +sequence that binds to that and you get +another weight matrix now remember this + + align:start position:0% +another weight matrix now remember this + + + align:start position:0% +another weight matrix now remember this +weight matrix is not sequence alignment + + align:start position:0% +weight matrix is not sequence alignment + + + align:start position:0% +weight matrix is not sequence alignment +this is uh binding constants where the + + align:start position:0% +this is uh binding constants where the + + + align:start position:0% +this is uh binding constants where the +weighting of the of the 64 different + + align:start position:0% +weighting of the of the 64 different + + + align:start position:0% +weighting of the of the 64 different +sequences is based on how much binding + + align:start position:0% +sequences is based on how much binding + + + align:start position:0% +sequences is based on how much binding +you get for each of the 64. + + align:start position:0% +you get for each of the 64. + + + align:start position:0% +you get for each of the 64. +and then for some sequences all these + + align:start position:0% +and then for some sequences all these + + + align:start position:0% +and then for some sequences all these +different trinucleotides all result in a + + align:start position:0% +different trinucleotides all result in a + + + align:start position:0% +different trinucleotides all result in a +rather poor selection for any kind of + + align:start position:0% +rather poor selection for any kind of + + + align:start position:0% +rather poor selection for any kind of +peptide out of all the vast number of + + align:start position:0% +peptide out of all the vast number of + + + align:start position:0% +peptide out of all the vast number of +peptides you could have none of them do + + align:start position:0% +peptides you could have none of them do + + + align:start position:0% +peptides you could have none of them do +particularly well and the result is a + + align:start position:0% +particularly well and the result is a + + + align:start position:0% +particularly well and the result is a +weight matrix here + + align:start position:0% +weight matrix here + + + align:start position:0% +weight matrix here +which has very little information + + align:start position:0% +which has very little information + + + align:start position:0% +which has very little information +content so so this is a way it's not the + + align:start position:0% +content so so this is a way it's not the + + + align:start position:0% +content so so this is a way it's not the +only way but this is a way of getting + + align:start position:0% +only way but this is a way of getting + + + align:start position:0% +only way but this is a way of getting +a really good empirical data set which + + align:start position:0% +a really good empirical data set which + + + align:start position:0% +a really good empirical data set which +will in principle you can combine it + + align:start position:0% +will in principle you can combine it + + + align:start position:0% +will in principle you can combine it +with with similar functions on the + + align:start position:0% +with with similar functions on the + + + align:start position:0% +with with similar functions on the +flanking ones and you can create you can + + align:start position:0% +flanking ones and you can create you can + + + align:start position:0% +flanking ones and you can create you can +dial up any sequence + + align:start position:0% +dial up any sequence + + + align:start position:0% +dial up any sequence +of a + + align:start position:0% +of a + + + align:start position:0% +of a +nucleic acid protein interaction at + + align:start position:0% +nucleic acid protein interaction at + + + align:start position:0% +nucleic acid protein interaction at +least with this class of proteins others + + align:start position:0% +least with this class of proteins others + + + align:start position:0% +least with this class of proteins others +are are a little more problematic but + + align:start position:0% +are are a little more problematic but + + + align:start position:0% +are are a little more problematic but +you can see how this you can generate a + + align:start position:0% +you can see how this you can generate a + + + align:start position:0% +you can see how this you can generate a +code even if the the actual detailed + + align:start position:0% +code even if the the actual detailed + + + align:start position:0% +code even if the the actual detailed +amino acid + + align:start position:0% +amino acid + + + align:start position:0% +amino acid +nucleotide interaction is not so simple + + align:start position:0% +nucleotide interaction is not so simple + + + align:start position:0% +nucleotide interaction is not so simple +so that that those are the results of + + align:start position:0% +so that that those are the results of + + + align:start position:0% +so that that those are the results of +the study then i'll show you just a + + align:start position:0% +the study then i'll show you just a + + + align:start position:0% +the study then i'll show you just a +snapshot of a schematic of how the + + align:start position:0% +snapshot of a schematic of how the + + + align:start position:0% +snapshot of a schematic of how the +actual experiment was done and then + + align:start position:0% +actual experiment was done and then + + + align:start position:0% +actual experiment was done and then +finally i'll show you a little math + + align:start position:0% +finally i'll show you a little math + + + align:start position:0% +finally i'll show you a little math +behind how we got those apparent binding + + align:start position:0% +behind how we got those apparent binding + + + align:start position:0% +behind how we got those apparent binding +constants remember in those lower + + align:start position:0% +constants remember in those lower + + + align:start position:0% +constants remember in those lower +binding constant means it goes to you + + align:start position:0% +binding constant means it goes to you + + + align:start position:0% +binding constant means it goes to you +can get the binding at a lower + + align:start position:0% +can get the binding at a lower + + + align:start position:0% +can get the binding at a lower +concentration which means it's stronger + + align:start position:0% +concentration which means it's stronger + + + align:start position:0% +concentration which means it's stronger +binding + + align:start position:0% +binding + + + align:start position:0% +binding +so the way you do the binding here is + + align:start position:0% +so the way you do the binding here is + + + align:start position:0% +so the way you do the binding here is +you take a + + align:start position:0% +you take a + + + align:start position:0% +you take a +a nucleic acid array simple similar to + + align:start position:0% +a nucleic acid array simple similar to + + + align:start position:0% +a nucleic acid array simple similar to +the ones we've been talking about in + + align:start position:0% +the ones we've been talking about in + + + align:start position:0% +the ones we've been talking about in +last class + + align:start position:0% +last class + + + align:start position:0% +last class +instead of being single stranded ready + + align:start position:0% +instead of being single stranded ready + + + align:start position:0% +instead of being single stranded ready +to bind fluorescent nucleic acid it's + + align:start position:0% +to bind fluorescent nucleic acid it's + + + align:start position:0% +to bind fluorescent nucleic acid it's +double stranded ready to bind the + + align:start position:0% +double stranded ready to bind the + + + align:start position:0% +double stranded ready to bind the +fluorescent protein complex + + align:start position:0% +fluorescent protein complex + + + align:start position:0% +fluorescent protein complex +the protein complex in this case is a a + + align:start position:0% +the protein complex in this case is a a + + + align:start position:0% +the protein complex in this case is a a +bacteriophage which is displaying the + + align:start position:0% +bacteriophage which is displaying the + + + align:start position:0% +bacteriophage which is displaying the +three zinc fingers in red the middle one + + align:start position:0% +three zinc fingers in red the middle one + + + align:start position:0% +three zinc fingers in red the middle one +is the one that in the + + align:start position:0% +is the one that in the + + + align:start position:0% +is the one that in the +past slide was mutagenized + + align:start position:0% +past slide was mutagenized + + + align:start position:0% +past slide was mutagenized +and uh similarly the array is + + align:start position:0% +and uh similarly the array is + + + align:start position:0% +and uh similarly the array is +combinatoric every possible dna sequence + + align:start position:0% +combinatoric every possible dna sequence + + + align:start position:0% +combinatoric every possible dna sequence +uh that you're interested in is present + + align:start position:0% +uh that you're interested in is present + + + align:start position:0% +uh that you're interested in is present +and and what you do is you quantitate + + align:start position:0% +and and what you do is you quantitate + + + align:start position:0% +and and what you do is you quantitate +the fluorescence + + align:start position:0% +the fluorescence + + + align:start position:0% +the fluorescence +of the of the zinc finger uh protein + + align:start position:0% +of the of the zinc finger uh protein + + + align:start position:0% +of the of the zinc finger uh protein +indirectly by is the binding of the + + align:start position:0% +indirectly by is the binding of the + + + align:start position:0% +indirectly by is the binding of the +covalent with hat stage + + align:start position:0% +covalent with hat stage + + + align:start position:0% +covalent with hat stage +to the antibodies which are + + align:start position:0% +to the antibodies which are + + + align:start position:0% +to the antibodies which are +fluorescently labeled by phytoerrythrin + + align:start position:0% + + + + align:start position:0% + +the quantity how you relate the + + align:start position:0% +the quantity how you relate the + + + align:start position:0% +the quantity how you relate the +fluorescence the more binding the more + + align:start position:0% +fluorescence the more binding the more + + + align:start position:0% +fluorescence the more binding the more +fluorescence but how you relate that to + + align:start position:0% +fluorescence but how you relate that to + + + align:start position:0% +fluorescence but how you relate that to +the binding counts that we had in the + + align:start position:0% +the binding counts that we had in the + + + align:start position:0% +the binding counts that we had in the +previous slide + + align:start position:0% +previous slide + + + align:start position:0% +previous slide +is the subject and then of this slide + + align:start position:0% +is the subject and then of this slide + + + align:start position:0% +is the subject and then of this slide +number eight + + align:start position:0% +number eight + + + align:start position:0% +number eight +now we call this the apparent + + align:start position:0% +now we call this the apparent + + + align:start position:0% +now we call this the apparent +equilibrium association constant because + + align:start position:0% +equilibrium association constant because + + + align:start position:0% +equilibrium association constant because +these experiments just like many + + align:start position:0% +these experiments just like many + + + align:start position:0% +these experiments just like many +uh binding in + + align:start position:0% +uh binding in + + + align:start position:0% +uh binding in +in living cells is not at equilibrium + + align:start position:0% +in living cells is not at equilibrium + + + align:start position:0% +in living cells is not at equilibrium +it's a dynamic process + + align:start position:0% +it's a dynamic process + + + align:start position:0% +it's a dynamic process +in the cell and in vitro + + align:start position:0% +in the cell and in vitro + + + align:start position:0% +in the cell and in vitro +there are ways that you can measure the + + align:start position:0% +there are ways that you can measure the + + + align:start position:0% +there are ways that you can measure the +the equilibrium constants but but what + + align:start position:0% +the equilibrium constants but but what + + + align:start position:0% +the equilibrium constants but but what +this is apparent in the sense that you + + align:start position:0% +this is apparent in the sense that you + + + align:start position:0% +this is apparent in the sense that you +need to wash off the excess fluorescence + + align:start position:0% +need to wash off the excess fluorescence + + + align:start position:0% +need to wash off the excess fluorescence +in order to detect the fairly low signal + + align:start position:0% +in order to detect the fairly low signal + + + align:start position:0% +in order to detect the fairly low signal +that you get from the binding uh the + + align:start position:0% +that you get from the binding uh the + + + align:start position:0% +that you get from the binding uh the +specific binding rather than having + + align:start position:0% +specific binding rather than having + + + align:start position:0% +specific binding rather than having +fluorescence you you bathe it with 10 to + + align:start position:0% +fluorescence you you bathe it with 10 to + + + align:start position:0% +fluorescence you you bathe it with 10 to +the six-fold excess of fluorescence + + align:start position:0% +the six-fold excess of fluorescence + + + align:start position:0% +the six-fold excess of fluorescence +and so as you're doing that wash you're + + align:start position:0% +and so as you're doing that wash you're + + + align:start position:0% +and so as you're doing that wash you're +obviously not at equilibrium in the end + + align:start position:0% +obviously not at equilibrium in the end + + + align:start position:0% +obviously not at equilibrium in the end +you take a snapshot before you wash off + + align:start position:0% +you take a snapshot before you wash off + + + align:start position:0% +you take a snapshot before you wash off +everything + + align:start position:0% +everything + + + align:start position:0% +everything +and uh and so what you're measuring if + + align:start position:0% +and uh and so what you're measuring if + + + align:start position:0% +and uh and so what you're measuring if +you what you're basically measuring is + + align:start position:0% +you what you're basically measuring is + + + align:start position:0% +you what you're basically measuring is +attempting to measure is the equilibrium + + align:start position:0% +attempting to measure is the equilibrium + + + align:start position:0% +attempting to measure is the equilibrium +constant between protein p + + align:start position:0% +constant between protein p + + + align:start position:0% +constant between protein p +and the upper left here dnad + + align:start position:0% +and the upper left here dnad + + + align:start position:0% +and the upper left here dnad +double-stranded + + align:start position:0% +double-stranded + + + align:start position:0% +double-stranded +going to the product which is this p dot + + align:start position:0% +going to the product which is this p dot + + + align:start position:0% +going to the product which is this p dot +d uh associated + + align:start position:0% +d uh associated + + + align:start position:0% +d uh associated +by molecular product + + align:start position:0% +by molecular product + + + align:start position:0% +by molecular product +and this is uh this is basic + + align:start position:0% +and this is uh this is basic + + + align:start position:0% +and this is uh this is basic +physical chemistry + + align:start position:0% +physical chemistry + + + align:start position:0% +physical chemistry +and algebra so that so you rearrange + + align:start position:0% +and algebra so that so you rearrange + + + align:start position:0% +and algebra so that so you rearrange +that to get the uh association constant + + align:start position:0% +that to get the uh association constant + + + align:start position:0% +that to get the uh association constant +that's what you want + + align:start position:0% +that's what you want + + + align:start position:0% +that's what you want +and the fraction of dna molecules with + + align:start position:0% +and the fraction of dna molecules with + + + align:start position:0% +and the fraction of dna molecules with +protein bounds can be re can be found + + align:start position:0% +protein bounds can be re can be found + + + align:start position:0% +protein bounds can be re can be found +from this it's just + + align:start position:0% +from this it's just + + + align:start position:0% +from this it's just +a by definition the pr fraction of dna + + align:start position:0% +a by definition the pr fraction of dna + + + align:start position:0% +a by definition the pr fraction of dna +molecules putting bound is the + + align:start position:0% +molecules putting bound is the + + + align:start position:0% +molecules putting bound is the +the protein bound is the numerator the + + align:start position:0% +the protein bound is the numerator the + + + align:start position:0% +the protein bound is the numerator the +brackets mean concentration of moles per + + align:start position:0% +brackets mean concentration of moles per + + + align:start position:0% +brackets mean concentration of moles per +liter just like we stated + + align:start position:0% +liter just like we stated + + + align:start position:0% +liter just like we stated +and then divide the the complex by the + + align:start position:0% +and then divide the the complex by the + + + align:start position:0% +and then divide the the complex by the +amount of the fraction which is the + + align:start position:0% +amount of the fraction which is the + + + align:start position:0% +amount of the fraction which is the +total + + align:start position:0% +total + + + align:start position:0% +total +dna which is the dna present in the + + align:start position:0% +dna which is the dna present in the + + + align:start position:0% +dna which is the dna present in the +complex and the dna is free that's the d + + align:start position:0% +complex and the dna is free that's the d + + + align:start position:0% +complex and the dna is free that's the d +plus pd + + align:start position:0% +plus pd + + + align:start position:0% +plus pd +and then you just substitute in this + + align:start position:0% +and then you just substitute in this + + + align:start position:0% +and then you just substitute in this +definition of the association constant + + align:start position:0% +definition of the association constant + + + align:start position:0% +definition of the association constant +the definition is product over reactants + + align:start position:0% +the definition is product over reactants + + + align:start position:0% +the definition is product over reactants +and + + align:start position:0% + + + + align:start position:0% + +and then you get this intermediate term + + align:start position:0% +and then you get this intermediate term + + + align:start position:0% +and then you get this intermediate term +which now you cancel out all the + + align:start position:0% +which now you cancel out all the + + + align:start position:0% +which now you cancel out all the +concentrations of these + + align:start position:0% +concentrations of these + + + align:start position:0% +concentrations of these +and then you end up with the last term + + align:start position:0% +and then you end up with the last term + + + align:start position:0% +and then you end up with the last term +on the far right which is + + align:start position:0% +on the far right which is + + + align:start position:0% +on the far right which is +where if you hold the protein if the + + align:start position:0% +where if you hold the protein if the + + + align:start position:0% +where if you hold the protein if the +protein concentration is known + + align:start position:0% +protein concentration is known + + + align:start position:0% +protein concentration is known +then then the whole thing is constant + + align:start position:0% +then then the whole thing is constant + + + align:start position:0% +then then the whole thing is constant +except for the association so that one + + align:start position:0% +except for the association so that one + + + align:start position:0% +except for the association so that one +over the association constant + + align:start position:0% +over the association constant + + + align:start position:0% +over the association constant +is directly related to fraction dna + + align:start position:0% +is directly related to fraction dna + + + align:start position:0% +is directly related to fraction dna +molecules + + align:start position:0% +molecules + + + align:start position:0% +molecules +with protein bound which is uh directly + + align:start position:0% +with protein bound which is uh directly + + + align:start position:0% +with protein bound which is uh directly +proportional to the signal intensity + + align:start position:0% +proportional to the signal intensity + + + align:start position:0% +proportional to the signal intensity +and fluorescence + + align:start position:0% +and fluorescence + + + align:start position:0% +and fluorescence +so this is how you get the the numbers + + align:start position:0% +so this is how you get the the numbers + + + align:start position:0% +so this is how you get the the numbers +that were on that slide now let's return + + align:start position:0% +that were on that slide now let's return + + + align:start position:0% +that were on that slide now let's return +the question that connected this talk + + align:start position:0% +the question that connected this talk + + + align:start position:0% +the question that connected this talk +with last one which was the symmetry of + + align:start position:0% +with last one which was the symmetry of + + + align:start position:0% +with last one which was the symmetry of +dna protein interactions + + align:start position:0% +dna protein interactions + + + align:start position:0% +dna protein interactions +this + + align:start position:0% +this + + + align:start position:0% +this +we illustrated already one of these + + align:start position:0% +we illustrated already one of these + + + align:start position:0% +we illustrated already one of these +three zinc finger + + align:start position:0% +three zinc finger + + + align:start position:0% +three zinc finger +complexes as illustrated on the left + + align:start position:0% +complexes as illustrated on the left + + + align:start position:0% +complexes as illustrated on the left +hand side of the side + + align:start position:0% +hand side of the side + + + align:start position:0% +hand side of the side +uh here the the the the + + align:start position:0% +uh here the the the the + + + align:start position:0% +uh here the the the the +the + + align:start position:0% +the + + + align:start position:0% +the +double strand dna is in blue and the + + align:start position:0% +double strand dna is in blue and the + + + align:start position:0% +double strand dna is in blue and the +three zinc fingers follow along the + + align:start position:0% +three zinc fingers follow along the + + + align:start position:0% +three zinc fingers follow along the +major groove the large groove of the dna + + align:start position:0% + + + + align:start position:0% + +and the the reason this the textbook is + + align:start position:0% +and the the reason this the textbook is + + + align:start position:0% +and the the reason this the textbook is +wrong first of all it emphasizes the + + align:start position:0% +wrong first of all it emphasizes the + + + align:start position:0% +wrong first of all it emphasizes the +non-helical part of the zinc finger you + + align:start position:0% +non-helical part of the zinc finger you + + + align:start position:0% +non-helical part of the zinc finger you +can barely see the helix in the + + align:start position:0% +can barely see the helix in the + + + align:start position:0% +can barely see the helix in the +background there and also the way it + + align:start position:0% +background there and also the way it + + + align:start position:0% +background there and also the way it +loops through the dna if you look at + + align:start position:0% +loops through the dna if you look at + + + align:start position:0% +loops through the dna if you look at +this carefully in your textbook this is + + align:start position:0% +this carefully in your textbook this is + + + align:start position:0% +this carefully in your textbook this is +actually the notebook + + align:start position:0% +actually the notebook + + + align:start position:0% +actually the notebook +it actually interdigitates with a + + align:start position:0% +it actually interdigitates with a + + + align:start position:0% +it actually interdigitates with a +phosphodiester bond basically going + + align:start position:0% +phosphodiester bond basically going + + + align:start position:0% +phosphodiester bond basically going +through the base pairs which is not at + + align:start position:0% +through the base pairs which is not at + + + align:start position:0% +through the base pairs which is not at +all what happens + + align:start position:0% +all what happens + + + align:start position:0% +all what happens +similarly to the leucine zipper this is + + align:start position:0% +similarly to the leucine zipper this is + + + align:start position:0% +similarly to the leucine zipper this is +a again recognition with a helix in the + + align:start position:0% +a again recognition with a helix in the + + + align:start position:0% +a again recognition with a helix in the +major groove of dna + + align:start position:0% +major groove of dna + + + align:start position:0% +major groove of dna +here you can see that the helix that + + align:start position:0% +here you can see that the helix that + + + align:start position:0% +here you can see that the helix that +causes the dimerization of proteins you + + align:start position:0% +causes the dimerization of proteins you + + + align:start position:0% +causes the dimerization of proteins you +can think of this as your really most + + align:start position:0% +can think of this as your really most + + + align:start position:0% +can think of this as your really most +elementary protein protein interaction + + align:start position:0% +elementary protein protein interaction + + + align:start position:0% +elementary protein protein interaction +code a very fundamental one that comes + + align:start position:0% +code a very fundamental one that comes + + + align:start position:0% +code a very fundamental one that comes +again and again so-called coil coil two + + align:start position:0% +again and again so-called coil coil two + + + align:start position:0% +again and again so-called coil coil two +alpha helices interacting + + align:start position:0% +alpha helices interacting + + + align:start position:0% +alpha helices interacting +they they direct the extension of that + + align:start position:0% +they they direct the extension of that + + + align:start position:0% +they they direct the extension of that +almost coaxial with a coil coil or + + align:start position:0% +almost coaxial with a coil coil or + + + align:start position:0% +almost coaxial with a coil coil or +protein protein interaction they go down + + align:start position:0% +protein protein interaction they go down + + + align:start position:0% +protein protein interaction they go down +and touch the dna in contrast the + + align:start position:0% +and touch the dna in contrast the + + + align:start position:0% +and touch the dna in contrast the +textbook where that does this sharp + + align:start position:0% +textbook where that does this sharp + + + align:start position:0% +textbook where that does this sharp +right-hand turn and in some way uh + + align:start position:0% +right-hand turn and in some way uh + + + align:start position:0% +right-hand turn and in some way uh +poorly schematic + + align:start position:0% +poorly schematic + + + align:start position:0% +poorly schematic +poorly schematized there it goes coaxial + + align:start position:0% +poorly schematized there it goes coaxial + + + align:start position:0% +poorly schematized there it goes coaxial +with the dna that's not what happens the + + align:start position:0% +with the dna that's not what happens the + + + align:start position:0% +with the dna that's not what happens the +protein the the helices are more or less + + align:start position:0% +protein the the helices are more or less + + + align:start position:0% +protein the the helices are more or less +direct extensions down from the + + align:start position:0% +direct extensions down from the + + + align:start position:0% +direct extensions down from the +dimerization + + align:start position:0% +dimerization + + + align:start position:0% +dimerization +region of the protein + + align:start position:0% +region of the protein + + + align:start position:0% +region of the protein +maintaining almost perpendicular to the + + align:start position:0% +maintaining almost perpendicular to the + + + align:start position:0% +maintaining almost perpendicular to the +dna axis + + align:start position:0% +dna axis + + + align:start position:0% +dna axis +okay but again so on the left is the + + align:start position:0% +okay but again so on the left is the + + + align:start position:0% +okay but again so on the left is the +three tandem repeats + + align:start position:0% +three tandem repeats + + + align:start position:0% +three tandem repeats +and on the right is a diat axis where + + align:start position:0% +and on the right is a diat axis where + + + align:start position:0% +and on the right is a diat axis where +the + + align:start position:0% +the + + + align:start position:0% +the +two-fold 180 degrees symmetry think of + + align:start position:0% +two-fold 180 degrees symmetry think of + + + align:start position:0% +two-fold 180 degrees symmetry think of +it as rotating exactly + + align:start position:0% +it as rotating exactly + + + align:start position:0% +it as rotating exactly +uh 180 degrees this is not a mirror this + + align:start position:0% +uh 180 degrees this is not a mirror this + + + align:start position:0% +uh 180 degrees this is not a mirror this +is a rotation of the dna on itself + + align:start position:0% +is a rotation of the dna on itself + + + align:start position:0% +is a rotation of the dna on itself +also coincides perfectly with the + + align:start position:0% +also coincides perfectly with the + + + align:start position:0% +also coincides perfectly with the +two-fold symmetry of the of the protein + + align:start position:0% +two-fold symmetry of the of the protein + + + align:start position:0% +two-fold symmetry of the of the protein +association with itself these are the + + align:start position:0% +association with itself these are the + + + align:start position:0% +association with itself these are the +two major symmetry classes and it's + + align:start position:0% +two major symmetry classes and it's + + + align:start position:0% +two major symmetry classes and it's +amazing how how many nucleic acid + + align:start position:0% +amazing how how many nucleic acid + + + align:start position:0% +amazing how how many nucleic acid +protein interactions fall into one of + + align:start position:0% +protein interactions fall into one of + + + align:start position:0% +protein interactions fall into one of +these two classes direct repeat or + + align:start position:0% +these two classes direct repeat or + + + align:start position:0% +these two classes direct repeat or +inverted repeat and that's when you find + + align:start position:0% +inverted repeat and that's when you find + + + align:start position:0% +inverted repeat and that's when you find +direct inverted repeats in nucleic acid + + align:start position:0% +direct inverted repeats in nucleic acid + + + align:start position:0% +direct inverted repeats in nucleic acid +sequences you're getting a little + + align:start position:0% +sequences you're getting a little + + + align:start position:0% +sequences you're getting a little +excited the other reason + + align:start position:0% +excited the other reason + + + align:start position:0% +excited the other reason +is + + align:start position:0% +is + + + align:start position:0% +is +is the hairpin structures that you found + + align:start position:0% +is the hairpin structures that you found + + + align:start position:0% +is the hairpin structures that you found +in rna that we talked about in the last + + align:start position:0% +in rna that we talked about in the last + + + align:start position:0% +in rna that we talked about in the last +classes + + align:start position:0% +classes + + + align:start position:0% +classes +those also are indicated by inverter + + align:start position:0% +those also are indicated by inverter + + + align:start position:0% +those also are indicated by inverter +repeats + + align:start position:0% +repeats + + + align:start position:0% +repeats +but okay so we now have + + align:start position:0% +but okay so we now have + + + align:start position:0% +but okay so we now have +a a semi-empirical way of computing + + align:start position:0% +a a semi-empirical way of computing + + + align:start position:0% +a a semi-empirical way of computing +in a certain sense predicting new + + align:start position:0% +in a certain sense predicting new + + + align:start position:0% +in a certain sense predicting new +regulatory protein dna interactions with + + align:start position:0% +regulatory protein dna interactions with + + + align:start position:0% +regulatory protein dna interactions with +double-stranded dna + + align:start position:0% +double-stranded dna + + + align:start position:0% +double-stranded dna +can we extend this to rna this is a much + + align:start position:0% +can we extend this to rna this is a much + + + align:start position:0% +can we extend this to rna this is a much +more complicated + + align:start position:0% +more complicated + + + align:start position:0% +more complicated +situation with rna because you don't + + align:start position:0% +situation with rna because you don't + + + align:start position:0% +situation with rna because you don't +have these long perfect double helixes + + align:start position:0% +have these long perfect double helixes + + + align:start position:0% +have these long perfect double helixes +anymore you have these very short rna + + align:start position:0% +anymore you have these very short rna + + + align:start position:0% +anymore you have these very short rna +helices that i showed in the last couple + + align:start position:0% +helices that i showed in the last couple + + + align:start position:0% +helices that i showed in the last couple +of classes this is transfer rna one of + + align:start position:0% +of classes this is transfer rna one of + + + align:start position:0% +of classes this is transfer rna one of +our favorite molecules here the + + align:start position:0% +our favorite molecules here the + + + align:start position:0% +our favorite molecules here the +anticodon at the bottom of each of the + + align:start position:0% +anticodon at the bottom of each of the + + + align:start position:0% +anticodon at the bottom of each of the +pink structures and the amino acid + + align:start position:0% +pink structures and the amino acid + + + align:start position:0% +pink structures and the amino acid +acceptor three prime end of that + + align:start position:0% +acceptor three prime end of that + + + align:start position:0% +acceptor three prime end of that +seventy some nucleotide uh + + align:start position:0% +seventy some nucleotide uh + + + align:start position:0% +seventy some nucleotide uh +seventy to eighty nucleotide nucleic + + align:start position:0% +seventy to eighty nucleotide nucleic + + + align:start position:0% +seventy to eighty nucleotide nucleic +acid the pinks are all the trnas and + + align:start position:0% +acid the pinks are all the trnas and + + + align:start position:0% +acid the pinks are all the trnas and +there are at least 20 different types of + + align:start position:0% +there are at least 20 different types of + + + align:start position:0% +there are at least 20 different types of +amino acid and has 20 types of at least + + align:start position:0% +amino acid and has 20 types of at least + + + align:start position:0% +amino acid and has 20 types of at least +20 types of transfer rnas and 20 types + + align:start position:0% +20 types of transfer rnas and 20 types + + + align:start position:0% +20 types of transfer rnas and 20 types +of proteins that add the amino acid onto + + align:start position:0% +of proteins that add the amino acid onto + + + align:start position:0% +of proteins that add the amino acid onto +the three prime end of the transfer rna + + align:start position:0% +the three prime end of the transfer rna + + + align:start position:0% +the three prime end of the transfer rna +these break themselves up into two major + + align:start position:0% +these break themselves up into two major + + + align:start position:0% +these break themselves up into two major +classes these can be recognized at the + + align:start position:0% +classes these can be recognized at the + + + align:start position:0% +classes these can be recognized at the +structural level class one which is the + + align:start position:0% +structural level class one which is the + + + align:start position:0% +structural level class one which is the +single letter amino acid code c + + align:start position:0% +single letter amino acid code c + + + align:start position:0% +single letter amino acid code c +e l so forth cysteine glutamate and so + + align:start position:0% +e l so forth cysteine glutamate and so + + + align:start position:0% +e l so forth cysteine glutamate and so +on that's one class which is + + align:start position:0% +on that's one class which is + + + align:start position:0% +on that's one class which is +structurally similar class two is + + align:start position:0% +structurally similar class two is + + + align:start position:0% +structurally similar class two is +structurally dissimilar to class one + + align:start position:0% +structurally dissimilar to class one + + + align:start position:0% +structurally dissimilar to class one +but they're similar within the class + + align:start position:0% +but they're similar within the class + + + align:start position:0% +but they're similar within the class +anyway the point is that + + align:start position:0% +anyway the point is that + + + align:start position:0% +anyway the point is that +they recognize all different parts of + + align:start position:0% +they recognize all different parts of + + + align:start position:0% +they recognize all different parts of +the nucleic acid not just the anticodon + + align:start position:0% +the nucleic acid not just the anticodon + + + align:start position:0% +the nucleic acid not just the anticodon +which is the + + align:start position:0% +which is the + + + align:start position:0% +which is the +code itself the trinucleotide code not + + align:start position:0% +code itself the trinucleotide code not + + + align:start position:0% +code itself the trinucleotide code not +just the amino acid in where you need to + + align:start position:0% +just the amino acid in where you need to + + + align:start position:0% +just the amino acid in where you need to +recognize amino acid + + align:start position:0% +recognize amino acid + + + align:start position:0% +recognize amino acid +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +but various points along the transfer + + align:start position:0% +but various points along the transfer + + + align:start position:0% +but various points along the transfer +rna + + align:start position:0% +rna + + + align:start position:0% +rna +if you wanted to create a new code as + + align:start position:0% +if you wanted to create a new code as + + + align:start position:0% +if you wanted to create a new code as +this these authors have + + align:start position:0% +this these authors have + + + align:start position:0% +this these authors have +or to create + + align:start position:0% +or to create + + + align:start position:0% +or to create +hybrids between these various things + + align:start position:0% +hybrids between these various things + + + align:start position:0% +hybrids between these various things +you'd have to find homology among the + + align:start position:0% +you'd have to find homology among the + + + align:start position:0% +you'd have to find homology among the +proteins or graft domains of recognition + + align:start position:0% +proteins or graft domains of recognition + + + align:start position:0% +proteins or graft domains of recognition +between each one or mutagenize + + align:start position:0% +between each one or mutagenize + + + align:start position:0% +between each one or mutagenize +particular regions that are known to + + align:start position:0% +particular regions that are known to + + + align:start position:0% +particular regions that are known to +interact with the nucleotides you want + + align:start position:0% +interact with the nucleotides you want + + + align:start position:0% +interact with the nucleotides you want +to to contact and that's that's been + + align:start position:0% +to to contact and that's that's been + + + align:start position:0% +to to contact and that's that's been +done you can arrange to make a new amino + + align:start position:0% +done you can arrange to make a new amino + + + align:start position:0% +done you can arrange to make a new amino +acid by carving the the uh + + align:start position:0% +acid by carving the the uh + + + align:start position:0% +acid by carving the the uh +the pocket the amino acid recognizes and + + align:start position:0% +the pocket the amino acid recognizes and + + + align:start position:0% +the pocket the amino acid recognizes and +grafting on the appropriate + + align:start position:0% +grafting on the appropriate + + + align:start position:0% +grafting on the appropriate +nucleotides that the appropriate amino + + align:start position:0% +nucleotides that the appropriate amino + + + align:start position:0% +nucleotides that the appropriate amino +acids would recognize say a stop codon + + align:start position:0% +acids would recognize say a stop codon + + + align:start position:0% +acids would recognize say a stop codon +okay + + align:start position:0% + + + + align:start position:0% + +you've had + + align:start position:0% +you've had + + + align:start position:0% +you've had +some programming experience that + + align:start position:0% +some programming experience that + + + align:start position:0% +some programming experience that +hopefully will prepare you for the real + + align:start position:0% +hopefully will prepare you for the real + + + align:start position:0% +hopefully will prepare you for the real +world of interacting with uh + + align:start position:0% +world of interacting with uh + + + align:start position:0% +world of interacting with uh +input and outputs from various devices + + align:start position:0% + + + + align:start position:0% + +the topic today is proteins and this + + align:start position:0% +the topic today is proteins and this + + + align:start position:0% +the topic today is proteins and this +really is the main uh + + align:start position:0% +really is the main uh + + + align:start position:0% +really is the main uh +contact between the exquisite regulatory + + align:start position:0% +contact between the exquisite regulatory + + + align:start position:0% +contact between the exquisite regulatory +mechanisms which will be the topic of + + align:start position:0% +mechanisms which will be the topic of + + + align:start position:0% +mechanisms which will be the topic of +the network + + align:start position:0% +the network + + + align:start position:0% +the network +that we've already touched upon but will + + align:start position:0% +that we've already touched upon but will + + + align:start position:0% +that we've already touched upon but will +really be the top work topic of some of + + align:start position:0% +really be the top work topic of some of + + + align:start position:0% +really be the top work topic of some of +our network analysis in the next uh in + + align:start position:0% +our network analysis in the next uh in + + + align:start position:0% +our network analysis in the next uh in +the last three lectures + + align:start position:0% +the last three lectures + + + align:start position:0% +the last three lectures +here we need sensors to sense the + + align:start position:0% +here we need sensors to sense the + + + align:start position:0% +here we need sensors to sense the +environment we need actuators to then + + align:start position:0% +environment we need actuators to then + + + align:start position:0% +environment we need actuators to then +deliver back into the environment what + + align:start position:0% +deliver back into the environment what + + + align:start position:0% +deliver back into the environment what +the what the cell wants to do or to + + align:start position:0% +the what the cell wants to do or to + + + align:start position:0% +the what the cell wants to do or to +interact with other cells + + align:start position:0% +interact with other cells + + + align:start position:0% +interact with other cells +you have to have feedback + + align:start position:0% +you have to have feedback + + + align:start position:0% +you have to have feedback +synchrony and so on + + align:start position:0% +synchrony and so on + + + align:start position:0% +synchrony and so on +that you can basically program the + + align:start position:0% +that you can basically program the + + + align:start position:0% +that you can basically program the +almost digital + + align:start position:0% +almost digital + + + align:start position:0% +almost digital +uh nucleic acid world inside the cell + + align:start position:0% +uh nucleic acid world inside the cell + + + align:start position:0% +uh nucleic acid world inside the cell +but via + + align:start position:0% +but via + + + align:start position:0% +but via +clearly analog inputs and outputs + + align:start position:0% +clearly analog inputs and outputs + + + align:start position:0% +clearly analog inputs and outputs +so uh + + align:start position:0% +so uh + + + align:start position:0% +so uh +since you know this is the halloween uh + + align:start position:0% +since you know this is the halloween uh + + + align:start position:0% +since you know this is the halloween uh +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +uh + + align:start position:0% +uh + + + align:start position:0% +uh +and i'm uh masquerading as wolfman + + align:start position:0% +and i'm uh masquerading as wolfman + + + align:start position:0% +and i'm uh masquerading as wolfman +we also i've listed some of the scariest + + align:start position:0% +we also i've listed some of the scariest + + + align:start position:0% +we also i've listed some of the scariest +uh proteins + + align:start position:0% +uh proteins + + + align:start position:0% +uh proteins +that i could think of and we're going to + + align:start position:0% +that i could think of and we're going to + + + align:start position:0% +that i could think of and we're going to +talk about + + align:start position:0% +talk about + + + align:start position:0% +talk about +three of them + + align:start position:0% +three of them + + + align:start position:0% +three of them +one of them in the slide which is the uh + + align:start position:0% +one of them in the slide which is the uh + + + align:start position:0% +one of them in the slide which is the uh +the + + align:start position:0% +the + + + align:start position:0% +the +the proteins are actually involved in + + align:start position:0% +the proteins are actually involved in + + + align:start position:0% +the proteins are actually involved in +causing the symptoms that come from uh + + align:start position:0% +causing the symptoms that come from uh + + + align:start position:0% +causing the symptoms that come from uh +when you worry about anthrax + + align:start position:0% +when you worry about anthrax + + + align:start position:0% +when you worry about anthrax +and then we'll talk about + + align:start position:0% +and then we'll talk about + + + align:start position:0% +and then we'll talk about +hiv yet again this time polymerase + + align:start position:0% +hiv yet again this time polymerase + + + align:start position:0% +hiv yet again this time polymerase +mutants that that cause drug resistance + + align:start position:0% +mutants that that cause drug resistance + + + align:start position:0% +mutants that that cause drug resistance +and then apoe yet again as we have in + + align:start position:0% +and then apoe yet again as we have in + + + align:start position:0% +and then apoe yet again as we have in +the past this time talking specifically + + align:start position:0% +the past this time talking specifically + + + align:start position:0% +the past this time talking specifically +about + + align:start position:0% +about + + + align:start position:0% +about +how protein structure tells it to happen + + align:start position:0% +how protein structure tells it to happen + + + align:start position:0% +how protein structure tells it to happen +so with anthrax you start out with this + + align:start position:0% +so with anthrax you start out with this + + + align:start position:0% +so with anthrax you start out with this +simple + + align:start position:0% +simple + + + align:start position:0% +simple +two component uh two protein domains + + align:start position:0% +two component uh two protein domains + + + align:start position:0% +two component uh two protein domains +here + + align:start position:0% +here + + + align:start position:0% +here +they bind to a cellular some something + + align:start position:0% +they bind to a cellular some something + + + align:start position:0% +they bind to a cellular some something +on your cell surface hopefully not yours + + align:start position:0% +on your cell surface hopefully not yours + + + align:start position:0% +on your cell surface hopefully not yours +but human cell surface + + align:start position:0% +but human cell surface + + + align:start position:0% +but human cell surface +um + + align:start position:0% +um + + + align:start position:0% +um +and then one of the domains disappears + + align:start position:0% +and then one of the domains disappears + + + align:start position:0% +and then one of the domains disappears +and the remaining one now self-assembles + + align:start position:0% +and the remaining one now self-assembles + + + align:start position:0% +and the remaining one now self-assembles +into a seven mer + + align:start position:0% +into a seven mer + + + align:start position:0% +into a seven mer +seven full symmetry remember we're + + align:start position:0% +seven full symmetry remember we're + + + align:start position:0% +seven full symmetry remember we're +talking about two-fold rotational + + align:start position:0% +talking about two-fold rotational + + + align:start position:0% +talking about two-fold rotational +symmetry for the dna protein interaction + + align:start position:0% +symmetry for the dna protein interaction + + + align:start position:0% +symmetry for the dna protein interaction +this is now seven-fold rotational + + align:start position:0% +this is now seven-fold rotational + + + align:start position:0% +this is now seven-fold rotational +symmetry that now allows this lethal + + align:start position:0% +symmetry that now allows this lethal + + + align:start position:0% +symmetry that now allows this lethal +factor lf to bind still not inside the + + align:start position:0% +factor lf to bind still not inside the + + + align:start position:0% +factor lf to bind still not inside the +cell + + align:start position:0% +cell + + + align:start position:0% +cell +but the whole the whole complex gets + + align:start position:0% +but the whole the whole complex gets + + + align:start position:0% +but the whole the whole complex gets +internalized + + align:start position:0% +internalized + + + align:start position:0% +internalized +still topologically it's as if it were + + align:start position:0% +still topologically it's as if it were + + + align:start position:0% +still topologically it's as if it were +outside the cell when it's inside this + + align:start position:0% +outside the cell when it's inside this + + + align:start position:0% +outside the cell when it's inside this +little vesicle it has to get through + + align:start position:0% +little vesicle it has to get through + + + align:start position:0% +little vesicle it has to get through +that + + align:start position:0% +that + + + align:start position:0% +that +membrane but now the ph change that + + align:start position:0% +membrane but now the ph change that + + + align:start position:0% +membrane but now the ph change that +happens when this vesicle goes in the + + align:start position:0% +happens when this vesicle goes in the + + + align:start position:0% +happens when this vesicle goes in the +cell + + align:start position:0% +cell + + + align:start position:0% +cell +part of the natural cell biological + + align:start position:0% +part of the natural cell biological + + + align:start position:0% +part of the natural cell biological +processes causes this + + align:start position:0% +processes causes this + + + align:start position:0% +processes causes this +unfortunate act where now the seven + + align:start position:0% +unfortunate act where now the seven + + + align:start position:0% +unfortunate act where now the seven +seven this complex of proteins does yet + + align:start position:0% +seven this complex of proteins does yet + + + align:start position:0% +seven this complex of proteins does yet +another conformational change + + align:start position:0% +another conformational change + + + align:start position:0% +another conformational change +and turns into this hairy beast that + + align:start position:0% +and turns into this hairy beast that + + + align:start position:0% +and turns into this hairy beast that +allows the + + align:start position:0% +allows the + + + align:start position:0% +allows the +lethal factor to get into your cell and + + align:start position:0% +lethal factor to get into your cell and + + + align:start position:0% +lethal factor to get into your cell and +kill it + + align:start position:0% +kill it + + + align:start position:0% +kill it +so you can see that that when we're + + align:start position:0% +so you can see that that when we're + + + align:start position:0% +so you can see that that when we're +talking about protein three-dimensional + + align:start position:0% +talking about protein three-dimensional + + + align:start position:0% +talking about protein three-dimensional +structure whether we're predicting it or + + align:start position:0% +structure whether we're predicting it or + + + align:start position:0% +structure whether we're predicting it or +solving it protein is not a + + align:start position:0% +solving it protein is not a + + + align:start position:0% +solving it protein is not a +static object here it associates with + + align:start position:0% +static object here it associates with + + + align:start position:0% +static object here it associates with +one factor it associates + + align:start position:0% +one factor it associates + + + align:start position:0% +one factor it associates +seven of itself in interaction lethal + + align:start position:0% +seven of itself in interaction lethal + + + align:start position:0% +seven of itself in interaction lethal +factor it opens up a whole new channel + + align:start position:0% +factor it opens up a whole new channel + + + align:start position:0% +factor it opens up a whole new channel +and a membrane etc + + align:start position:0% +and a membrane etc + + + align:start position:0% +and a membrane etc +you need to think of these as dynamic + + align:start position:0% +you need to think of these as dynamic + + + align:start position:0% +you need to think of these as dynamic +systems with many different states + + align:start position:0% + + + + align:start position:0% + +we also need to think about time scales + + align:start position:0% +we also need to think about time scales + + + align:start position:0% +we also need to think about time scales +many of the sim the molecular mechanics + + align:start position:0% +many of the sim the molecular mechanics + + + align:start position:0% +many of the sim the molecular mechanics +we'll be talking about the time scale of + + align:start position:0% +we'll be talking about the time scale of + + + align:start position:0% +we'll be talking about the time scale of +relevance is the femtosecond you need to + + align:start position:0% +relevance is the femtosecond you need to + + + align:start position:0% +relevance is the femtosecond you need to +be able this is uh or two then a second + + align:start position:0% +be able this is uh or two then a second + + + align:start position:0% +be able this is uh or two then a second +so ten to the minus fifteenth to the + + align:start position:0% +so ten to the minus fifteenth to the + + + align:start position:0% +so ten to the minus fifteenth to the +minus nine seconds that's atomic motion + + align:start position:0% +minus nine seconds that's atomic motion + + + align:start position:0% +minus nine seconds that's atomic motion +the turnover of an enzyme + + align:start position:0% +the turnover of an enzyme + + + align:start position:0% +the turnover of an enzyme +uh is that is the time it takes to for a + + align:start position:0% +uh is that is the time it takes to for a + + + align:start position:0% +uh is that is the time it takes to for a +small molecule say to bind to find and + + align:start position:0% +small molecule say to bind to find and + + + align:start position:0% +small molecule say to bind to find and +bind the enzyme to to to possibly go + + align:start position:0% +bind the enzyme to to to possibly go + + + align:start position:0% +bind the enzyme to to to possibly go +through a catalytic step and to + + align:start position:0% +through a catalytic step and to + + + align:start position:0% +through a catalytic step and to +dissociate as a product + + align:start position:0% +dissociate as a product + + + align:start position:0% +dissociate as a product +uh that's on the order microseconds to + + align:start position:0% +uh that's on the order microseconds to + + + align:start position:0% +uh that's on the order microseconds to +milliseconds in the second range is the + + align:start position:0% +milliseconds in the second range is the + + + align:start position:0% +milliseconds in the second range is the +time that it takes the molecule to + + align:start position:0% +time that it takes the molecule to + + + align:start position:0% +time that it takes the molecule to +the drug or small molecule to touch the + + align:start position:0% +the drug or small molecule to touch the + + + align:start position:0% +the drug or small molecule to touch the +surface of the cell maybe diffuse across + + align:start position:0% +surface of the cell maybe diffuse across + + + align:start position:0% +surface of the cell maybe diffuse across +the cell and find its target + + align:start position:0% +the cell and find its target + + + align:start position:0% +the cell and find its target +transcription that we talked about all + + align:start position:0% +transcription that we talked about all + + + align:start position:0% +transcription that we talked about all +the regulatory mechanisms of + + align:start position:0% +the regulatory mechanisms of + + + align:start position:0% +the regulatory mechanisms of +transcription + + align:start position:0% +transcription + + + align:start position:0% +transcription +last + + align:start position:0% +last + + + align:start position:0% +last +time the rate + + align:start position:0% +time the rate + + + align:start position:0% +time the rate +of the constant for that process is + + align:start position:0% +of the constant for that process is + + + align:start position:0% +of the constant for that process is +around + + align:start position:0% +around + + + align:start position:0% +around + + align:start position:0% + + + align:start position:0% +nucleotides per second coincid not + + align:start position:0% +nucleotides per second coincid not + + + align:start position:0% +nucleotides per second coincid not +entirely coincidentally that's about the + + align:start position:0% +entirely coincidentally that's about the + + + align:start position:0% +entirely coincidentally that's about the +rate at which + + align:start position:0% +rate at which + + + align:start position:0% +rate at which +it is translated into protein these are + + align:start position:0% +it is translated into protein these are + + + align:start position:0% +it is translated into protein these are +important numbers because a typical + + align:start position:0% +important numbers because a typical + + + align:start position:0% +important numbers because a typical +gene-sized piece + + align:start position:0% +gene-sized piece + + + align:start position:0% +gene-sized piece +say after + + align:start position:0% +say after + + + align:start position:0% +say after +uh rna splicing in higher organisms or + + align:start position:0% +uh rna splicing in higher organisms or + + + align:start position:0% +uh rna splicing in higher organisms or +or naturally + + align:start position:0% +or naturally + + + align:start position:0% +or naturally +it might be a kilobase so that's about a + + align:start position:0% +it might be a kilobase so that's about a + + + align:start position:0% +it might be a kilobase so that's about a +half a minute to transcribe and + + align:start position:0% +half a minute to transcribe and + + + align:start position:0% +half a minute to transcribe and +translate + + align:start position:0% + + + + align:start position:0% + +that could be used as the timer in a + + align:start position:0% +that could be used as the timer in a + + + align:start position:0% +that could be used as the timer in a +circuit + + align:start position:0% +circuit + + + align:start position:0% +circuit +of these longer time things time frames + + align:start position:0% +of these longer time things time frames + + + align:start position:0% +of these longer time things time frames +like cell cycle circadian rhythm + + align:start position:0% +like cell cycle circadian rhythm + + + align:start position:0% +like cell cycle circadian rhythm +uh very long time frames uh in + + align:start position:0% +uh very long time frames uh in + + + align:start position:0% +uh very long time frames uh in +ecological systems with bamboo and uh + + align:start position:0% +ecological systems with bamboo and uh + + + align:start position:0% +ecological systems with bamboo and uh +and various pests + + align:start position:0% +and various pests + + + align:start position:0% +and various pests +which can which can be uh not even + + align:start position:0% +which can which can be uh not even + + + align:start position:0% +which can which can be uh not even +yearly + + align:start position:0% +yearly + + + align:start position:0% +yearly +and then a development and aging which + + align:start position:0% +and then a development and aging which + + + align:start position:0% +and then a development and aging which +can be on the order of hundreds of years + + align:start position:0% +can be on the order of hundreds of years + + + align:start position:0% +can be on the order of hundreds of years +at least for humans + + align:start position:0% +at least for humans + + + align:start position:0% +at least for humans +turtles and whales + + align:start position:0% +turtles and whales + + + align:start position:0% +turtles and whales +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +what we think proteins are good for + + align:start position:0% +what we think proteins are good for + + + align:start position:0% +what we think proteins are good for +depends + + align:start position:0% +depends + + + align:start position:0% +depends +on the accuracy and the accuracy depends + + align:start position:0% +on the accuracy and the accuracy depends + + + align:start position:0% +on the accuracy and the accuracy depends +on the method at the very bottom right + + align:start position:0% +on the method at the very bottom right + + + align:start position:0% +on the method at the very bottom right +we have + + align:start position:0% +we have + + + align:start position:0% +we have +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a very + + align:start position:0% +a very + + + align:start position:0% +a very +appealing approach which is + + align:start position:0% +appealing approach which is + + + align:start position:0% +appealing approach which is +de novo + + align:start position:0% +de novo + + + align:start position:0% +de novo +a priori or + + align:start position:0% +a priori or + + + align:start position:0% +a priori or +or ab initio prediction of secondary of + + align:start position:0% +or ab initio prediction of secondary of + + + align:start position:0% +or ab initio prediction of secondary of +protein three-dimensional structure from + + align:start position:0% +protein three-dimensional structure from + + + align:start position:0% +protein three-dimensional structure from +the sequence alone which we're getting + + align:start position:0% +the sequence alone which we're getting + + + align:start position:0% +the sequence alone which we're getting +in bucket loads from the genome projects + + align:start position:0% +in bucket loads from the genome projects + + + align:start position:0% +in bucket loads from the genome projects +but unfortunately accuracy so far and + + align:start position:0% +but unfortunately accuracy so far and + + + align:start position:0% +but unfortunately accuracy so far and +we'll delve into this in more detail in + + align:start position:0% +we'll delve into this in more detail in + + + align:start position:0% +we'll delve into this in more detail in +a moment is on the order of six + + align:start position:0% +a moment is on the order of six + + + align:start position:0% +a moment is on the order of six +angstroms uh difference between the + + align:start position:0% +angstroms uh difference between the + + + align:start position:0% +angstroms uh difference between the +predicted structure and what it actually + + align:start position:0% +predicted structure and what it actually + + + align:start position:0% +predicted structure and what it actually +is by the more precise methods up higher + + align:start position:0% +is by the more precise methods up higher + + + align:start position:0% +is by the more precise methods up higher +on this + + align:start position:0% +on this + + + align:start position:0% +on this +the y-axis here the vertical axis is + + align:start position:0% +the y-axis here the vertical axis is + + + align:start position:0% +the y-axis here the vertical axis is +basically percent sequence identity as + + align:start position:0% +basically percent sequence identity as + + + align:start position:0% +basically percent sequence identity as +you start doing say threading or + + align:start position:0% +you start doing say threading or + + + align:start position:0% +you start doing say threading or +comparative modeling + + align:start position:0% +comparative modeling + + + align:start position:0% +comparative modeling +um here as you get up instead of + + align:start position:0% +um here as you get up instead of + + + align:start position:0% +um here as you get up instead of +the ab initio or de novo prediction + + align:start position:0% +the ab initio or de novo prediction + + + align:start position:0% +the ab initio or de novo prediction +doesn't require any sequence similarity + + align:start position:0% +doesn't require any sequence similarity + + + align:start position:0% +doesn't require any sequence similarity +if you want to build it based on + + align:start position:0% +if you want to build it based on + + + align:start position:0% +if you want to build it based on +previously solved structures you need at + + align:start position:0% +previously solved structures you need at + + + align:start position:0% +previously solved structures you need at +least three thirty percent but you still + + align:start position:0% +least three thirty percent but you still + + + align:start position:0% +least three thirty percent but you still +uh very far say three to four angstroms + + align:start position:0% +uh very far say three to four angstroms + + + align:start position:0% +uh very far say three to four angstroms +away + + align:start position:0% +away + + + align:start position:0% +away +from the uh native structure as you get + + align:start position:0% +from the uh native structure as you get + + + align:start position:0% +from the uh native structure as you get +to one angstrom or better in your + + align:start position:0% +to one angstrom or better in your + + + align:start position:0% +to one angstrom or better in your +accuracy as you can get from nmr and + + align:start position:0% +accuracy as you can get from nmr and + + + align:start position:0% +accuracy as you can get from nmr and +x-ray crystallography you now are in a + + align:start position:0% +x-ray crystallography you now are in a + + + align:start position:0% +x-ray crystallography you now are in a +position to study catalytic mechanism + + align:start position:0% +position to study catalytic mechanism + + + align:start position:0% +position to study catalytic mechanism +and design and improve ligands such as + + align:start position:0% +and design and improve ligands such as + + + align:start position:0% +and design and improve ligands such as +drugs this is really where we want to be + + align:start position:0% +drugs this is really where we want to be + + + align:start position:0% +drugs this is really where we want to be +there may be a day where we can do this + + align:start position:0% +there may be a day where we can do this + + + align:start position:0% +there may be a day where we can do this +all from ab initio prediction or + + align:start position:0% +all from ab initio prediction or + + + align:start position:0% +all from ab initio prediction or +modeling at very great distances but for + + align:start position:0% +modeling at very great distances but for + + + align:start position:0% +modeling at very great distances but for +now modeling at very short + + align:start position:0% +now modeling at very short + + + align:start position:0% +now modeling at very short +say 80 to 90 percent amino acid + + align:start position:0% +say 80 to 90 percent amino acid + + + align:start position:0% +say 80 to 90 percent amino acid +similarity is important remember there's + + align:start position:0% +similarity is important remember there's + + + align:start position:0% +similarity is important remember there's +a just like there's a variety of + + align:start position:0% +a just like there's a variety of + + + align:start position:0% +a just like there's a variety of +different protein structures + + align:start position:0% + + + + align:start position:0% + +uh this is just an example of a of a + + align:start position:0% +uh this is just an example of a of a + + + align:start position:0% +uh this is just an example of a of a +vast literature that exists where you + + align:start position:0% +vast literature that exists where you + + + align:start position:0% +vast literature that exists where you +can use + + align:start position:0% +can use + + + align:start position:0% +can use +uh some of the methods that we'll be + + align:start position:0% +uh some of the methods that we'll be + + + align:start position:0% +uh some of the methods that we'll be +discussing uh + + align:start position:0% +discussing uh + + + align:start position:0% +discussing uh +from + + align:start position:0% +from + + + align:start position:0% +from +in this in this class + + align:start position:0% +in this in this class + + + align:start position:0% +in this in this class +uh on doing molecular mechanics on + + align:start position:0% +uh on doing molecular mechanics on + + + align:start position:0% +uh on doing molecular mechanics on +proteins + + align:start position:0% +proteins + + + align:start position:0% +proteins +and predicting their three-dimensional + + align:start position:0% +and predicting their three-dimensional + + + align:start position:0% +and predicting their three-dimensional +structure + + align:start position:0% +structure + + + align:start position:0% +structure +in complex with + + align:start position:0% +in complex with + + + align:start position:0% +in complex with +the various drugs we will contrast this + + align:start position:0% +the various drugs we will contrast this + + + align:start position:0% +the various drugs we will contrast this +or show the interplay of the + + align:start position:0% +or show the interplay of the + + + align:start position:0% +or show the interplay of the +computational biology that can be aided + + align:start position:0% +computational biology that can be aided + + + align:start position:0% +computational biology that can be aided +by actual uh measurements of drug + + align:start position:0% +by actual uh measurements of drug + + + align:start position:0% +by actual uh measurements of drug +binding just as we had actual + + align:start position:0% +binding just as we had actual + + + align:start position:0% +binding just as we had actual +measurements of zinc finger binding to + + align:start position:0% +measurements of zinc finger binding to + + + align:start position:0% +measurements of zinc finger binding to +double-stranded dna + + align:start position:0% +double-stranded dna + + + align:start position:0% +double-stranded dna +and ways that you could discover this + + align:start position:0% +and ways that you could discover this + + + align:start position:0% +and ways that you could discover this +the small molecules by a clever + + align:start position:0% +the small molecules by a clever + + + align:start position:0% +the small molecules by a clever +use of parts of it that you know bind + + align:start position:0% +use of parts of it that you know bind + + + align:start position:0% +use of parts of it that you know bind +and parts of it + + align:start position:0% +and parts of it + + + align:start position:0% +and parts of it +that you know might + + align:start position:0% +that you know might + + + align:start position:0% +that you know might +be variable in a chemical sense + + align:start position:0% +be variable in a chemical sense + + + align:start position:0% +be variable in a chemical sense +now this is what + + align:start position:0% +now this is what + + + align:start position:0% +now this is what +just as there is this dynamic + + align:start position:0% +just as there is this dynamic + + + align:start position:0% +just as there is this dynamic +competition between + + align:start position:0% +competition between + + + align:start position:0% +competition between +pathogens and their hosts there's + + align:start position:0% +pathogens and their hosts there's + + + align:start position:0% +pathogens and their hosts there's +there's this + + align:start position:0% +there's this + + + align:start position:0% +there's this +similar lethal game that's played + + align:start position:0% +similar lethal game that's played + + + align:start position:0% +similar lethal game that's played +between pathogens in the pharmaceutical + + align:start position:0% +between pathogens in the pharmaceutical + + + align:start position:0% +between pathogens in the pharmaceutical +industry + + align:start position:0% +industry + + + align:start position:0% +industry +and here hiv for which there are many + + align:start position:0% +and here hiv for which there are many + + + align:start position:0% +and here hiv for which there are many +drugs now aimed either at the protease + + align:start position:0% +drugs now aimed either at the protease + + + align:start position:0% +drugs now aimed either at the protease +or at the + + align:start position:0% +or at the + + + align:start position:0% +or at the +uh polymerase some of the first ones + + align:start position:0% +uh polymerase some of the first ones + + + align:start position:0% +uh polymerase some of the first ones +were aimed at polymerase and so we have + + align:start position:0% +were aimed at polymerase and so we have + + + align:start position:0% +were aimed at polymerase and so we have +a big collection this is one of the most + + align:start position:0% +a big collection this is one of the most + + + align:start position:0% +a big collection this is one of the most +sequenced molecules on earth which is + + align:start position:0% +sequenced molecules on earth which is + + + align:start position:0% +sequenced molecules on earth which is +the hiv + + align:start position:0% +the hiv + + + align:start position:0% +the hiv +gene encoding the reverse transcriptase + + align:start position:0% +gene encoding the reverse transcriptase + + + align:start position:0% +gene encoding the reverse transcriptase +polymerase and it's been sequenced many + + align:start position:0% +polymerase and it's been sequenced many + + + align:start position:0% +polymerase and it's been sequenced many +times because as a patient takes the + + align:start position:0% +times because as a patient takes the + + + align:start position:0% +times because as a patient takes the +drugs that their population of aids + + align:start position:0% +drugs that their population of aids + + + align:start position:0% +drugs that their population of aids +virus changes + + align:start position:0% +virus changes + + + align:start position:0% +virus changes +and each of these little + + align:start position:0% +and each of these little + + + align:start position:0% +and each of these little +diamond-shaped substitution sites + + align:start position:0% +diamond-shaped substitution sites + + + align:start position:0% +diamond-shaped substitution sites +clustered around the binding site in the + + align:start position:0% +clustered around the binding site in the + + + align:start position:0% +clustered around the binding site in the +protein the binding site here indicated + + align:start position:0% +protein the binding site here indicated + + + align:start position:0% +protein the binding site here indicated +the substrate is in space filling which + + align:start position:0% +the substrate is in space filling which + + + align:start position:0% +the substrate is in space filling which +is the triphosphate on the on the upper + + align:start position:0% +is the triphosphate on the on the upper + + + align:start position:0% +is the triphosphate on the on the upper +left + + align:start position:0% +left + + + align:start position:0% +left +and the template kind of curving around + + align:start position:0% +and the template kind of curving around + + + align:start position:0% +and the template kind of curving around +on the right hand side of that space + + align:start position:0% +on the right hand side of that space + + + align:start position:0% +on the right hand side of that space +filling um + + align:start position:0% +filling um + + + align:start position:0% +filling um +bright green structure + + align:start position:0% +bright green structure + + + align:start position:0% +bright green structure +the protein is is is a is in red and + + align:start position:0% +the protein is is is a is in red and + + + align:start position:0% +the protein is is is a is in red and +these little diamonds indicate + + align:start position:0% +these little diamonds indicate + + + align:start position:0% +these little diamonds indicate +substitutions where the nomenclature is + + align:start position:0% +substitutions where the nomenclature is + + + align:start position:0% +substitutions where the nomenclature is +single letter code for the wild type + + align:start position:0% +single letter code for the wild type + + + align:start position:0% +single letter code for the wild type +the + + align:start position:0% +the + + + align:start position:0% +the +position + + align:start position:0% +position + + + align:start position:0% +position +in amino acids from the n-terminus is + + align:start position:0% +in amino acids from the n-terminus is + + + align:start position:0% +in amino acids from the n-terminus is +the number and then the + + align:start position:0% +the number and then the + + + align:start position:0% +the number and then the +the third + + align:start position:0% +the third + + + align:start position:0% +the third +or the last + + align:start position:0% +or the last + + + align:start position:0% +or the last +far right letter is the new amino acid + + align:start position:0% +far right letter is the new amino acid + + + align:start position:0% +far right letter is the new amino acid +so for example d67n means aspartate at + + align:start position:0% +so for example d67n means aspartate at + + + align:start position:0% +so for example d67n means aspartate at +position 67 and wild type changes to an + + align:start position:0% +position 67 and wild type changes to an + + + align:start position:0% +position 67 and wild type changes to an +asparagine and that causes a drug + + align:start position:0% +asparagine and that causes a drug + + + align:start position:0% +asparagine and that causes a drug +resistance in the hiv with unfortunate + + align:start position:0% +resistance in the hiv with unfortunate + + + align:start position:0% +resistance in the hiv with unfortunate +consequences for the patient + + align:start position:0% + + + + align:start position:0% + +we + + align:start position:0% +we + + + align:start position:0% +we +can take now + + align:start position:0% +can take now + + + align:start position:0% +can take now +making mutations in polymerases is not + + align:start position:0% +making mutations in polymerases is not + + + align:start position:0% +making mutations in polymerases is not +entirely of negative consequences and + + align:start position:0% +entirely of negative consequences and + + + align:start position:0% +entirely of negative consequences and +i'm going to show you a really beautiful + + align:start position:0% +i'm going to show you a really beautiful + + + align:start position:0% +i'm going to show you a really beautiful +example + + align:start position:0% +example + + + align:start position:0% +example +where + + align:start position:0% +where + + + align:start position:0% +where +a dna polymerase + + align:start position:0% +a dna polymerase + + + align:start position:0% +a dna polymerase +very similar kind of dynamic where your + + align:start position:0% +very similar kind of dynamic where your + + + align:start position:0% +very similar kind of dynamic where your +you the dna polymerase you want to + + align:start position:0% +you the dna polymerase you want to + + + align:start position:0% +you the dna polymerase you want to +change it so that it can now + + align:start position:0% +change it so that it can now + + + align:start position:0% +change it so that it can now +handle a an inhibitor what would + + align:start position:0% +handle a an inhibitor what would + + + align:start position:0% +handle a an inhibitor what would +normally be an inhibitor of dna + + align:start position:0% +normally be an inhibitor of dna + + + align:start position:0% +normally be an inhibitor of dna +polymerase + + align:start position:0% + + + + align:start position:0% + +a class of + + align:start position:0% +a class of + + + align:start position:0% +a class of +nucleotides + + align:start position:0% +nucleotides + + + align:start position:0% +nucleotides +that is incapable of extending + + align:start position:0% +that is incapable of extending + + + align:start position:0% +that is incapable of extending +capability incorporated into the growing + + align:start position:0% +capability incorporated into the growing + + + align:start position:0% +capability incorporated into the growing +um + + align:start position:0% +um + + + align:start position:0% +um +replicating + + align:start position:0% +replicating + + + align:start position:0% +replicating +genome of of uh but is not a cable of + + align:start position:0% +genome of of uh but is not a cable of + + + align:start position:0% +genome of of uh but is not a cable of +extending is a powerful inhibitor and + + align:start position:0% +extending is a powerful inhibitor and + + + align:start position:0% +extending is a powerful inhibitor and +it's also powerful sequencing reagent + + align:start position:0% +it's also powerful sequencing reagent + + + align:start position:0% +it's also powerful sequencing reagent +these are dideoxies + + align:start position:0% +these are dideoxies + + + align:start position:0% +these are dideoxies +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +so one of the things that was noticed + + align:start position:0% +so one of the things that was noticed + + + align:start position:0% +so one of the things that was noticed +as the + + align:start position:0% +as the + + + align:start position:0% +as the +sequences of some of these polymerases + + align:start position:0% +sequences of some of these polymerases + + + align:start position:0% +sequences of some of these polymerases +were being studied and some of the + + align:start position:0% +were being studied and some of the + + + align:start position:0% +were being studied and some of the +resistance mutants and so on + + align:start position:0% +resistance mutants and so on + + + align:start position:0% +resistance mutants and so on +it was noticed that + + align:start position:0% +it was noticed that + + + align:start position:0% +it was noticed that +that the complex between + + align:start position:0% +that the complex between + + + align:start position:0% +that the complex between +the + + align:start position:0% +the + + + align:start position:0% +the +nucleotide whether it's a + + align:start position:0% +nucleotide whether it's a + + + align:start position:0% +nucleotide whether it's a +deoxynucleotide + + align:start position:0% +deoxynucleotide + + + align:start position:0% +deoxynucleotide +shown here with a three-prime hydroxyl + + align:start position:0% +shown here with a three-prime hydroxyl + + + align:start position:0% +shown here with a three-prime hydroxyl +which could then be extended + + align:start position:0% +which could then be extended + + + align:start position:0% +which could then be extended +by bringing in the next five-five + + align:start position:0% +by bringing in the next five-five + + + align:start position:0% +by bringing in the next five-five +triphosphate + + align:start position:0% +triphosphate + + + align:start position:0% +triphosphate +this hydroxyl is near in space + + align:start position:0% +this hydroxyl is near in space + + + align:start position:0% +this hydroxyl is near in space +to the position on a phenylalanine or a + + align:start position:0% +to the position on a phenylalanine or a + + + align:start position:0% +to the position on a phenylalanine or a +tyrosine position 762 of this polymerase + + align:start position:0% +tyrosine position 762 of this polymerase + + + align:start position:0% +tyrosine position 762 of this polymerase +which can either + + align:start position:0% +which can either + + + align:start position:0% +which can either +if it's a tyrosine that has a oh there + + align:start position:0% +if it's a tyrosine that has a oh there + + + align:start position:0% +if it's a tyrosine that has a oh there +and if it's a phenylalanine you lose the + + align:start position:0% +and if it's a phenylalanine you lose the + + + align:start position:0% +and if it's a phenylalanine you lose the +o and you just have a hydrogen there + + align:start position:0% +o and you just have a hydrogen there + + + align:start position:0% +o and you just have a hydrogen there +and when you have + + align:start position:0% +and when you have + + + align:start position:0% +and when you have +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the the phenylalanine there there's + + align:start position:0% +the the phenylalanine there there's + + + align:start position:0% +the the phenylalanine there there's +a space that that that uh an appropriate + + align:start position:0% +a space that that that uh an appropriate + + + align:start position:0% +a space that that that uh an appropriate +space that accommodates the three prime + + align:start position:0% +space that accommodates the three prime + + + align:start position:0% +space that accommodates the three prime +hydroxyl quite well but if you now may + + align:start position:0% +hydroxyl quite well but if you now may + + + align:start position:0% +hydroxyl quite well but if you now may +put in a dideoxy inhibitor you now have + + align:start position:0% +put in a dideoxy inhibitor you now have + + + align:start position:0% +put in a dideoxy inhibitor you now have +too much space in there and you start + + align:start position:0% +too much space in there and you start + + + align:start position:0% +too much space in there and you start +trying to fill that space with uh other + + align:start position:0% +trying to fill that space with uh other + + + align:start position:0% +trying to fill that space with uh other +bulky molecules like water + + align:start position:0% +bulky molecules like water + + + align:start position:0% +bulky molecules like water +and basically + + align:start position:0% +and basically + + + align:start position:0% +and basically +the binding constant + + align:start position:0% +the binding constant + + + align:start position:0% +the binding constant +it becomes it becomes much less + + align:start position:0% +it becomes it becomes much less + + + align:start position:0% +it becomes it becomes much less +favorable binding when you have a when + + align:start position:0% +favorable binding when you have a when + + + align:start position:0% +favorable binding when you have a when +you're lacking both oxygens so + + align:start position:0% +you're lacking both oxygens so + + + align:start position:0% +you're lacking both oxygens so +this would present an opportunity to + + align:start position:0% +this would present an opportunity to + + + align:start position:0% +this would present an opportunity to +engineer some polymerases which uh + + align:start position:0% +engineer some polymerases which uh + + + align:start position:0% +engineer some polymerases which uh +had a + + align:start position:0% +had a + + + align:start position:0% +had a +phenylalanine there to become more + + align:start position:0% +phenylalanine there to become more + + + align:start position:0% +phenylalanine there to become more +accepting of the dideoxys and hence + + align:start position:0% +accepting of the dideoxys and hence + + + align:start position:0% +accepting of the dideoxys and hence +better at using the ideologies in dna + + align:start position:0% +better at using the ideologies in dna + + + align:start position:0% +better at using the ideologies in dna +sequencing chemistry + + align:start position:0% +sequencing chemistry + + + align:start position:0% +sequencing chemistry +and and this was simply by engineering + + align:start position:0% +and and this was simply by engineering + + + align:start position:0% +and and this was simply by engineering +putting in that oxygen there by changing + + align:start position:0% +putting in that oxygen there by changing + + + align:start position:0% +putting in that oxygen there by changing +the phenylalanine to a tyrosine it now + + align:start position:0% +the phenylalanine to a tyrosine it now + + + align:start position:0% +the phenylalanine to a tyrosine it now +made a better fit between uh you could + + align:start position:0% +made a better fit between uh you could + + + align:start position:0% +made a better fit between uh you could +you can think of it as + + align:start position:0% +you can think of it as + + + align:start position:0% +you can think of it as +you can have either oxygen + + align:start position:0% +you can have either oxygen + + + align:start position:0% +you can have either oxygen +and by removing this oxygen you you + + align:start position:0% +and by removing this oxygen you you + + + align:start position:0% +and by removing this oxygen you you +replace it with an oxygen on the protein + + align:start position:0% +replace it with an oxygen on the protein + + + align:start position:0% +replace it with an oxygen on the protein +side + + align:start position:0% +side + + + align:start position:0% +side +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +i'm trying to emphasize by a few + + align:start position:0% +i'm trying to emphasize by a few + + + align:start position:0% +i'm trying to emphasize by a few +examples here the idea of complementary + + align:start position:0% +examples here the idea of complementary + + + align:start position:0% +examples here the idea of complementary +surfaces and how you can engineer them + + align:start position:0% +surfaces and how you can engineer them + + + align:start position:0% +surfaces and how you can engineer them +this is a beautiful case now we're + + align:start position:0% +this is a beautiful case now we're + + + align:start position:0% +this is a beautiful case now we're +talking about single atom rather than + + align:start position:0% +talking about single atom rather than + + + align:start position:0% +talking about single atom rather than +the complementary surfaces of the + + align:start position:0% +the complementary surfaces of the + + + align:start position:0% +the complementary surfaces of the +nucleic acids we were talking about + + align:start position:0% +nucleic acids we were talking about + + + align:start position:0% +nucleic acids we were talking about +before + + align:start position:0% +before + + + align:start position:0% +before +this has an 8 000 fold effect on the + + align:start position:0% +this has an 8 000 fold effect on the + + + align:start position:0% +this has an 8 000 fold effect on the +specificity of this polymerase and a big + + align:start position:0% +specificity of this polymerase and a big + + + align:start position:0% +specificity of this polymerase and a big +impact on the genome project + + align:start position:0% +impact on the genome project + + + align:start position:0% +impact on the genome project +now that's how we program a particular + + align:start position:0% +now that's how we program a particular + + + align:start position:0% +now that's how we program a particular +atom to achieve an important goal and of + + align:start position:0% +atom to achieve an important goal and of + + + align:start position:0% +atom to achieve an important goal and of +course the virus has its own mechanisms + + align:start position:0% +course the virus has its own mechanisms + + + align:start position:0% +course the virus has its own mechanisms +for programming it + + align:start position:0% +for programming it + + + align:start position:0% +for programming it +typically by random mutagenesis and + + align:start position:0% +typically by random mutagenesis and + + + align:start position:0% +typically by random mutagenesis and +selection as we talked about in the + + align:start position:0% +selection as we talked about in the + + + align:start position:0% +selection as we talked about in the +population genetics but the way we + + align:start position:0% +population genetics but the way we + + + align:start position:0% +population genetics but the way we +program in general proteins are either + + align:start position:0% +program in general proteins are either + + + align:start position:0% +program in general proteins are either +transgenics where we might + + align:start position:0% +transgenics where we might + + + align:start position:0% +transgenics where we might +over produce the protein + + align:start position:0% +over produce the protein + + + align:start position:0% +over produce the protein +or homologous recombination which is the + + align:start position:0% +or homologous recombination which is the + + + align:start position:0% +or homologous recombination which is the +ultimate where we go in and if the + + align:start position:0% +ultimate where we go in and if the + + + align:start position:0% +ultimate where we go in and if the +protein is already if the gene encoding + + align:start position:0% +protein is already if the gene encoding + + + align:start position:0% +protein is already if the gene encoding +the protein is already present we can + + align:start position:0% +the protein is already present we can + + + align:start position:0% +the protein is already present we can +change that particular nucleotide in c2 + + align:start position:0% +change that particular nucleotide in c2 + + + align:start position:0% +change that particular nucleotide in c2 +in the correct place so it's properly + + align:start position:0% +in the correct place so it's properly + + + align:start position:0% +in the correct place so it's properly +regulated and everything that's a great + + align:start position:0% +regulated and everything that's a great + + + align:start position:0% +regulated and everything that's a great +way to + + align:start position:0% +way to + + + align:start position:0% +way to +to do it + + align:start position:0% +to do it + + + align:start position:0% +to do it +point mutants are not the only way to + + align:start position:0% +point mutants are not the only way to + + + align:start position:0% +point mutants are not the only way to +generate conditional mutants many of + + align:start position:0% +generate conditional mutants many of + + + align:start position:0% +generate conditional mutants many of +them historically work but there are + + align:start position:0% +them historically work but there are + + + align:start position:0% +them historically work but there are +ways that you can program in conditional + + align:start position:0% +ways that you can program in conditional + + + align:start position:0% +ways that you can program in conditional +meaning that you can regulate under what + + align:start position:0% +meaning that you can regulate under what + + + align:start position:0% +meaning that you can regulate under what +conditions the protein is expressed or + + align:start position:0% +conditions the protein is expressed or + + + align:start position:0% +conditions the protein is expressed or +not or active or not + + align:start position:0% +not or active or not + + + align:start position:0% +not or active or not +with an entire domain + + align:start position:0% +with an entire domain + + + align:start position:0% +with an entire domain +or with single nucleotide polymorphisms + + align:start position:0% +or with single nucleotide polymorphisms + + + align:start position:0% +or with single nucleotide polymorphisms +now so this is one way this is this is + + align:start position:0% +now so this is one way this is this is + + + align:start position:0% +now so this is one way this is this is +the nucleic acid way + + align:start position:0% +the nucleic acid way + + + align:start position:0% +the nucleic acid way +another way is by modulating the + + align:start position:0% +another way is by modulating the + + + align:start position:0% +another way is by modulating the +activity of the proteins + + align:start position:0% +activity of the proteins + + + align:start position:0% +activity of the proteins +from the outside with + + align:start position:0% +from the outside with + + + align:start position:0% +from the outside with +with uh drugs or drug-like molecules and + + align:start position:0% +with uh drugs or drug-like molecules and + + + align:start position:0% +with uh drugs or drug-like molecules and +chemical genetics + + align:start position:0% +chemical genetics + + + align:start position:0% +chemical genetics +and under the subheadings for that you + + align:start position:0% +and under the subheadings for that you + + + align:start position:0% +and under the subheadings for that you +can make these by combinatorial + + align:start position:0% +can make these by combinatorial + + + align:start position:0% +can make these by combinatorial +synthesis and we'll show an example of + + align:start position:0% +synthesis and we'll show an example of + + + align:start position:0% +synthesis and we'll show an example of +that the combinatorial synthesis can be + + align:start position:0% +that the combinatorial synthesis can be + + + align:start position:0% +that the combinatorial synthesis can be +based on design principles not just + + align:start position:0% +based on design principles not just + + + align:start position:0% +based on design principles not just +completely random + + align:start position:0% +completely random + + + align:start position:0% +completely random +usually are the design principles can + + align:start position:0% +usually are the design principles can + + + align:start position:0% +usually are the design principles can +take into account what you know about + + align:start position:0% +take into account what you know about + + + align:start position:0% +take into account what you know about +the nature of the interaction of of + + align:start position:0% +the nature of the interaction of of + + + align:start position:0% +the nature of the interaction of of +similar + + align:start position:0% +similar + + + align:start position:0% +similar +proteins + + align:start position:0% +proteins + + + align:start position:0% +proteins +and you can mine + + align:start position:0% +and you can mine + + + align:start position:0% +and you can mine +whatever uh + + align:start position:0% + + + + align:start position:0% + +biochemical data that you can collect + + align:start position:0% +biochemical data that you can collect + + + align:start position:0% +biochemical data that you can collect +for so-called quantitative structure + + align:start position:0% +for so-called quantitative structure + + + align:start position:0% +for so-called quantitative structure +activity relationships this is a + + align:start position:0% +activity relationships this is a + + + align:start position:0% +activity relationships this is a +slightly different discipline + + align:start position:0% +slightly different discipline + + + align:start position:0% +slightly different discipline +than the than the + + align:start position:0% +than the than the + + + align:start position:0% +than the than the +detailed crystallographic uh + + align:start position:0% +detailed crystallographic uh + + + align:start position:0% +detailed crystallographic uh +and quantitative studies that we've + + align:start position:0% +and quantitative studies that we've + + + align:start position:0% +and quantitative studies that we've +talked about so far here you're trying + + align:start position:0% +talked about so far here you're trying + + + align:start position:0% +talked about so far here you're trying +to basically mine + + align:start position:0% +to basically mine + + + align:start position:0% +to basically mine +through + + align:start position:0% +through + + + align:start position:0% +through +the structures of the ligand itself + + align:start position:0% +the structures of the ligand itself + + + align:start position:0% +the structures of the ligand itself +for the parts of the ligand that might + + align:start position:0% +for the parts of the ligand that might + + + align:start position:0% +for the parts of the ligand that might +be responsible for the activity the + + align:start position:0% +be responsible for the activity the + + + align:start position:0% +be responsible for the activity the +binding activity or the full biological + + align:start position:0% +binding activity or the full biological + + + align:start position:0% +binding activity or the full biological +activity that you see + + align:start position:0% +activity that you see + + + align:start position:0% +activity that you see +so let's look at some examples of single + + align:start position:0% +so let's look at some examples of single + + + align:start position:0% +so let's look at some examples of single +nucleotide polymorphisms that we've been + + align:start position:0% +nucleotide polymorphisms that we've been + + + align:start position:0% +nucleotide polymorphisms that we've been +talking about before + + align:start position:0% +talking about before + + + align:start position:0% +talking about before +um + + align:start position:0% +um + + + align:start position:0% +um +actually + + align:start position:0% +actually + + + align:start position:0% +actually +this is a class that we + + align:start position:0% +this is a class that we + + + align:start position:0% +this is a class that we +didn't discuss before + + align:start position:0% +didn't discuss before + + + align:start position:0% +didn't discuss before +but uh in previous classes but it's re + + align:start position:0% +but uh in previous classes but it's re + + + align:start position:0% +but uh in previous classes but it's re +related to what we've been talking about + + align:start position:0% +related to what we've been talking about + + + align:start position:0% +related to what we've been talking about +in the case of the zinc finger we made + + align:start position:0% +in the case of the zinc finger we made + + + align:start position:0% +in the case of the zinc finger we made +an altered specificity we made new zinc + + align:start position:0% +an altered specificity we made new zinc + + + align:start position:0% +an altered specificity we made new zinc +fingers of bind to completely new + + align:start position:0% +fingers of bind to completely new + + + align:start position:0% +fingers of bind to completely new +trinucleotides + + align:start position:0% +trinucleotides + + + align:start position:0% +trinucleotides +with the + + align:start position:0% +with the + + + align:start position:0% +with the +dna polymerase by changing one amino + + align:start position:0% +dna polymerase by changing one amino + + + align:start position:0% +dna polymerase by changing one amino +acid we could make it now accept + + align:start position:0% +acid we could make it now accept + + + align:start position:0% +acid we could make it now accept +almost four logs better a an inhibitor + + align:start position:0% +almost four logs better a an inhibitor + + + align:start position:0% +almost four logs better a an inhibitor +is very useful and here + + align:start position:0% +is very useful and here + + + align:start position:0% +is very useful and here +we have many different many of these are + + align:start position:0% +we have many different many of these are + + + align:start position:0% +we have many different many of these are +enzymes + + align:start position:0% +enzymes + + + align:start position:0% +enzymes +where you can not just knock out the + + align:start position:0% +where you can not just knock out the + + + align:start position:0% +where you can not just knock out the +enzyme but actually make it recognize a + + align:start position:0% +enzyme but actually make it recognize a + + + align:start position:0% +enzyme but actually make it recognize a +new substrate or + + align:start position:0% +new substrate or + + + align:start position:0% +new substrate or +change radically the binding constant + + align:start position:0% +change radically the binding constant + + + align:start position:0% +change radically the binding constant +and catalytic rate for new substrates + + align:start position:0% +and catalytic rate for new substrates + + + align:start position:0% +and catalytic rate for new substrates +all right + + align:start position:0% + + + + align:start position:0% + +and i and i just have this long fine + + align:start position:0% +and i and i just have this long fine + + + align:start position:0% +and i and i just have this long fine +print slide just to impress with you + + align:start position:0% +print slide just to impress with you + + + align:start position:0% +print slide just to impress with you +this is actually less than half of the + + align:start position:0% +this is actually less than half of the + + + align:start position:0% +this is actually less than half of the +list + + align:start position:0% +list + + + align:start position:0% +list +just how many examples these are not + + align:start position:0% +just how many examples these are not + + + align:start position:0% +just how many examples these are not +that unusual and those are + + align:start position:0% +that unusual and those are + + + align:start position:0% +that unusual and those are +and those can be designed or naturally + + align:start position:0% +and those can be designed or naturally + + + align:start position:0% +and those can be designed or naturally +occurring + + align:start position:0% +occurring + + + align:start position:0% +occurring +now + + align:start position:0% +now + + + align:start position:0% +now +we're going to take the + + align:start position:0% +we're going to take the + + + align:start position:0% +we're going to take the +three-dimensional structure of proteins + + align:start position:0% +three-dimensional structure of proteins + + + align:start position:0% +three-dimensional structure of proteins +to connect and connect it with + + align:start position:0% +to connect and connect it with + + + align:start position:0% +to connect and connect it with +the our discussion of + + align:start position:0% +the our discussion of + + + align:start position:0% +the our discussion of +uh haplotypes and single nucleotide + + align:start position:0% +uh haplotypes and single nucleotide + + + align:start position:0% +uh haplotypes and single nucleotide +polymorphisms and you may recall + + align:start position:0% +polymorphisms and you may recall + + + align:start position:0% +polymorphisms and you may recall +that with one of the + + align:start position:0% +that with one of the + + + align:start position:0% +that with one of the +commonly occurring single nucleotide + + align:start position:0% +commonly occurring single nucleotide + + + align:start position:0% +commonly occurring single nucleotide +polymorphisms + + align:start position:0% +polymorphisms + + + align:start position:0% +polymorphisms +is the apoe4 allele it's present in 20 + + align:start position:0% +is the apoe4 allele it's present in 20 + + + align:start position:0% +is the apoe4 allele it's present in 20 +of the human population even though it + + align:start position:0% +of the human population even though it + + + align:start position:0% +of the human population even though it +has + + align:start position:0% +has + + + align:start position:0% +has +uh unfortunate consequences we think + + align:start position:0% +uh unfortunate consequences we think + + + align:start position:0% +uh unfortunate consequences we think +mainly + + align:start position:0% +mainly + + + align:start position:0% +mainly +for alzheimer's + + align:start position:0% +for alzheimer's + + + align:start position:0% +for alzheimer's +uh increases the risk of alzheimer's and + + align:start position:0% +uh increases the risk of alzheimer's and + + + align:start position:0% +uh increases the risk of alzheimer's and +in probably increases cardiovascular + + align:start position:0% + + + + align:start position:0% + +fitness through its uh + + align:start position:0% +fitness through its uh + + + align:start position:0% +fitness through its uh +apoe refers to its involvement in + + align:start position:0% +apoe refers to its involvement in + + + align:start position:0% +apoe refers to its involvement in +cholesterol metabolism and transport the + + align:start position:0% +cholesterol metabolism and transport the + + + align:start position:0% +cholesterol metabolism and transport the +apoe3 allele is present about 80 percent + + align:start position:0% +apoe3 allele is present about 80 percent + + + align:start position:0% +apoe3 allele is present about 80 percent +and is far more common in human + + align:start position:0% +and is far more common in human + + + align:start position:0% +and is far more common in human +populations but both of these would be + + align:start position:0% +populations but both of these would be + + + align:start position:0% +populations but both of these would be +considered very common alleles we also + + align:start position:0% +considered very common alleles we also + + + align:start position:0% +considered very common alleles we also +mentioned that the ancestral form of + + align:start position:0% +mentioned that the ancestral form of + + + align:start position:0% +mentioned that the ancestral form of +this for example found in chimpanzees at + + align:start position:0% +this for example found in chimpanzees at + + + align:start position:0% +this for example found in chimpanzees at +nearly a hundred percent is this + + align:start position:0% +nearly a hundred percent is this + + + align:start position:0% +nearly a hundred percent is this +arginine 112 + + align:start position:0% +arginine 112 + + + align:start position:0% +arginine 112 +instead of what's now common in human + + align:start position:0% +instead of what's now common in human + + + align:start position:0% +instead of what's now common in human +populations was cysteine 112. and that + + align:start position:0% +populations was cysteine 112. and that + + + align:start position:0% +populations was cysteine 112. and that +was one explanation for that might be + + align:start position:0% +was one explanation for that might be + + + align:start position:0% +was one explanation for that might be +that it was physiologically + + align:start position:0% +that it was physiologically + + + align:start position:0% +that it was physiologically +our nutritional + + align:start position:0% +our nutritional + + + align:start position:0% +our nutritional +standards have changed we now eat a lot + + align:start position:0% +standards have changed we now eat a lot + + + align:start position:0% +standards have changed we now eat a lot +more fatty things we live long enough to + + align:start position:0% +more fatty things we live long enough to + + + align:start position:0% +more fatty things we live long enough to +get alzheimer's and so maybe this was + + align:start position:0% +get alzheimer's and so maybe this was + + + align:start position:0% +get alzheimer's and so maybe this was +something this uh + + align:start position:0% +something this uh + + + align:start position:0% +something this uh +was something that was uh this battle e4 + + align:start position:0% +was something that was uh this battle e4 + + + align:start position:0% +was something that was uh this battle e4 +was good in chimpanzees that have + + align:start position:0% +was good in chimpanzees that have + + + align:start position:0% +was good in chimpanzees that have +different diets or lifespans + + align:start position:0% +different diets or lifespans + + + align:start position:0% +different diets or lifespans +but + + align:start position:0% +but + + + align:start position:0% +but +the other possibility and and i can't + + align:start position:0% +the other possibility and and i can't + + + align:start position:0% +the other possibility and and i can't +really distinguish between these right + + align:start position:0% +really distinguish between these right + + + align:start position:0% +really distinguish between these right +now but another one to seriously + + align:start position:0% +now but another one to seriously + + + align:start position:0% +now but another one to seriously +consider not just in this case but in + + align:start position:0% +consider not just in this case but in + + + align:start position:0% +consider not just in this case but in +cases in general is you no longer just + + align:start position:0% +cases in general is you no longer just + + + align:start position:0% +cases in general is you no longer just +think about single nucleotides you think + + align:start position:0% +think about single nucleotides you think + + + align:start position:0% +think about single nucleotides you think +about haplotypes + + align:start position:0% +about haplotypes + + + align:start position:0% +about haplotypes +in cis on that dna strand + + align:start position:0% +in cis on that dna strand + + + align:start position:0% +in cis on that dna strand +has a chance of affecting either the + + align:start position:0% +has a chance of affecting either the + + + align:start position:0% +has a chance of affecting either the +expression level of the protein or + + align:start position:0% +expression level of the protein or + + + align:start position:0% +expression level of the protein or +insists on the protein strand to to fold + + align:start position:0% +insists on the protein strand to to fold + + + align:start position:0% +insists on the protein strand to to fold +back and interact and you can see that + + align:start position:0% +back and interact and you can see that + + + align:start position:0% +back and interact and you can see that +one of the nearest amino acids to this + + align:start position:0% +one of the nearest amino acids to this + + + align:start position:0% +one of the nearest amino acids to this +arginine 112 which is the the main + + align:start position:0% +arginine 112 which is the the main + + + align:start position:0% +arginine 112 which is the the main +difference between apoe4 and a43 + + align:start position:0% +difference between apoe4 and a43 + + + align:start position:0% +difference between apoe4 and a43 +arcg61 is the same on the two alleles + + align:start position:0% +arcg61 is the same on the two alleles + + + align:start position:0% +arcg61 is the same on the two alleles +but you think of this as one half of + + align:start position:0% +but you think of this as one half of + + + align:start position:0% +but you think of this as one half of +type + + align:start position:0% +type + + + align:start position:0% +type +and in chimpanzees the haplotype is now + + align:start position:0% +and in chimpanzees the haplotype is now + + + align:start position:0% +and in chimpanzees the haplotype is now +threonine one and you can think that + + align:start position:0% +threonine one and you can think that + + + align:start position:0% +threonine one and you can think that +that + + align:start position:0% +that + + + align:start position:0% +that +that a three arch + + align:start position:0% +that a three arch + + + align:start position:0% +that a three arch +in chimps uh and or ancestrally is not + + align:start position:0% +in chimps uh and or ancestrally is not + + + align:start position:0% +in chimps uh and or ancestrally is not +too different from a hard cis so so it + + align:start position:0% +too different from a hard cis so so it + + + align:start position:0% +too different from a hard cis so so it +the uh different order so it's like it's + + align:start position:0% +the uh different order so it's like it's + + + align:start position:0% +the uh different order so it's like it's +like this compensating complementary + + align:start position:0% +like this compensating complementary + + + align:start position:0% +like this compensating complementary +mutation just like we had + + align:start position:0% +mutation just like we had + + + align:start position:0% +mutation just like we had +in the + + align:start position:0% +in the + + + align:start position:0% +in the +in the uh + + align:start position:0% +in the uh + + + align:start position:0% +in the uh +the oxygens in the polymerase a couple + + align:start position:0% +the oxygens in the polymerase a couple + + + align:start position:0% +the oxygens in the polymerase a couple +of slides ago and you can think of the + + align:start position:0% +of slides ago and you can think of the + + + align:start position:0% +of slides ago and you can think of the +compensating mutations we have the + + align:start position:0% +compensating mutations we have the + + + align:start position:0% +compensating mutations we have the +mutual information theory for doing the + + align:start position:0% +mutual information theory for doing the + + + align:start position:0% +mutual information theory for doing the +trna structure think of complementary + + align:start position:0% +trna structure think of complementary + + + align:start position:0% +trna structure think of complementary +surfaces when you think of of a + + align:start position:0% +surfaces when you think of of a + + + align:start position:0% +surfaces when you think of of a +single nucleotides don't think of them + + align:start position:0% +single nucleotides don't think of them + + + align:start position:0% +single nucleotides don't think of them +as haplotype and possibly complementing + + align:start position:0% +as haplotype and possibly complementing + + + align:start position:0% +as haplotype and possibly complementing +constellations + + align:start position:0% +constellations + + + align:start position:0% +constellations +especially now + + align:start position:0% +especially now + + + align:start position:0% +especially now +this this brings us to the + + align:start position:0% +this this brings us to the + + + align:start position:0% +this this brings us to the +possible impact of three-dimensional + + align:start position:0% +possible impact of three-dimensional + + + align:start position:0% +possible impact of three-dimensional +structure on predicting deleterious + + align:start position:0% +structure on predicting deleterious + + + align:start position:0% +structure on predicting deleterious +human alleles if we suddenly had the + + align:start position:0% +human alleles if we suddenly had the + + + align:start position:0% +human alleles if we suddenly had the +sequence of everyone in this room and + + align:start position:0% +sequence of everyone in this room and + + + align:start position:0% +sequence of everyone in this room and +and we wanted our computer program to + + align:start position:0% +and we wanted our computer program to + + + align:start position:0% +and we wanted our computer program to +prioritize which ones should i pay + + align:start position:0% +prioritize which ones should i pay + + + align:start position:0% +prioritize which ones should i pay +attention to which + + align:start position:0% +attention to which + + + align:start position:0% +attention to which +deviations from the the most common + + align:start position:0% +deviations from the the most common + + + align:start position:0% +deviations from the the most common +allele should i look at first well you + + align:start position:0% +allele should i look at first well you + + + align:start position:0% +allele should i look at first well you +might think of these things in terms of + + align:start position:0% +might think of these things in terms of + + + align:start position:0% +might think of these things in terms of +proteins we've now gotten to the point + + align:start position:0% +proteins we've now gotten to the point + + + align:start position:0% +proteins we've now gotten to the point +for a course where we're talking about + + align:start position:0% +for a course where we're talking about + + + align:start position:0% +for a course where we're talking about +proteins you need to think about the + + align:start position:0% +proteins you need to think about the + + + align:start position:0% +proteins you need to think about the +three-dimensional structure who's near + + align:start position:0% +three-dimensional structure who's near + + + align:start position:0% +three-dimensional structure who's near +who in the structure + + align:start position:0% +who in the structure + + + align:start position:0% +who in the structure +you can think about binding sites these + + align:start position:0% +you can think about binding sites these + + + align:start position:0% +you can think about binding sites these +might be indicated by if you know the + + align:start position:0% +might be indicated by if you know the + + + align:start position:0% +might be indicated by if you know the +three initial structure + + align:start position:0% +three initial structure + + + align:start position:0% +three initial structure +or you know the conservation pattern in + + align:start position:0% +or you know the conservation pattern in + + + align:start position:0% +or you know the conservation pattern in +this family of proteins + + align:start position:0% +this family of proteins + + + align:start position:0% +this family of proteins +you can ask + + align:start position:0% +you can ask + + + align:start position:0% +you can ask +things about charge in that last slide + + align:start position:0% +things about charge in that last slide + + + align:start position:0% +things about charge in that last slide +we had the charge of the arginines + + align:start position:0% +we had the charge of the arginines + + + align:start position:0% +we had the charge of the arginines +being near a uh + + align:start position:0% +being near a uh + + + align:start position:0% +being near a uh +a compatibly uh partial negative charge + + align:start position:0% +a compatibly uh partial negative charge + + + align:start position:0% +a compatibly uh partial negative charge +on the cysteines or + + align:start position:0% +on the cysteines or + + + align:start position:0% +on the cysteines or +or uh + + align:start position:0% +or uh + + + align:start position:0% +or uh +threonines + + align:start position:0% +threonines + + + align:start position:0% +threonines +you could have a disulfide is a very + + align:start position:0% +you could have a disulfide is a very + + + align:start position:0% +you could have a disulfide is a very +important thing to lose um it's highly + + align:start position:0% +important thing to lose um it's highly + + + align:start position:0% +important thing to lose um it's highly +there tend to be highly conserved + + align:start position:0% +there tend to be highly conserved + + + align:start position:0% +there tend to be highly conserved +if you introduce + + align:start position:0% +if you introduce + + + align:start position:0% +if you introduce +a proline into what would normally be an + + align:start position:0% +a proline into what would normally be an + + + align:start position:0% +a proline into what would normally be an +alpha helix this is something where + + align:start position:0% +alpha helix this is something where + + + align:start position:0% +alpha helix this is something where +three knowledge of the three-dimensional + + align:start position:0% +three knowledge of the three-dimensional + + + align:start position:0% +three knowledge of the three-dimensional +structure would say oh that polling + + align:start position:0% +structure would say oh that polling + + + align:start position:0% +structure would say oh that polling +just a priori without any knowledge of + + align:start position:0% +just a priori without any knowledge of + + + align:start position:0% +just a priori without any knowledge of +conservation is it could be a huge + + align:start position:0% +conservation is it could be a huge + + + align:start position:0% +conservation is it could be a huge +change in the three-dimensional + + align:start position:0% +change in the three-dimensional + + + align:start position:0% +change in the three-dimensional +structure + + align:start position:0% +structure + + + align:start position:0% +structure +and then these multi-sequence profiles + + align:start position:0% +and then these multi-sequence profiles + + + align:start position:0% +and then these multi-sequence profiles +are a good way of looking at the + + align:start position:0% +are a good way of looking at the + + + align:start position:0% +are a good way of looking at the +conservation + + align:start position:0% +conservation + + + align:start position:0% +conservation +that's a way of prioritizing + + align:start position:0% +that's a way of prioritizing + + + align:start position:0% +that's a way of prioritizing +single nucleotide polymorphisms that + + align:start position:0% +single nucleotide polymorphisms that + + + align:start position:0% +single nucleotide polymorphisms that +might have impact on pharmacogenomics or + + align:start position:0% +might have impact on pharmacogenomics or + + + align:start position:0% +might have impact on pharmacogenomics or +disease in general + + align:start position:0% +disease in general + + + align:start position:0% +disease in general +now + + align:start position:0% +now + + + align:start position:0% +now +as we integrate that with the chemical + + align:start position:0% +as we integrate that with the chemical + + + align:start position:0% +as we integrate that with the chemical +diversity that we can create that's + + align:start position:0% +diversity that we can create that's + + + align:start position:0% +diversity that we can create that's +going to be the topic for the next few + + align:start position:0% +going to be the topic for the next few + + + align:start position:0% +going to be the topic for the next few +slides is how do we create chemical + + align:start position:0% +slides is how do we create chemical + + + align:start position:0% +slides is how do we create chemical +diversity + + align:start position:0% +diversity + + + align:start position:0% +diversity +and i'm going to introduce this the idea + + align:start position:0% +and i'm going to introduce this the idea + + + align:start position:0% +and i'm going to introduce this the idea +of chemical diversity + + align:start position:0% +of chemical diversity + + + align:start position:0% +of chemical diversity +in a way i hope nicely connects to where + + align:start position:0% +in a way i hope nicely connects to where + + + align:start position:0% +in a way i hope nicely connects to where +we've been with rna arrays + + align:start position:0% +we've been with rna arrays + + + align:start position:0% +we've been with rna arrays +rna eraser and the double-stranded dna + + align:start position:0% +rna eraser and the double-stranded dna + + + align:start position:0% +rna eraser and the double-stranded dna +array that we used earlier in class + + align:start position:0% +array that we used earlier in class + + + align:start position:0% +array that we used earlier in class +today + + align:start position:0% +today + + + align:start position:0% +today +can be generated in a combinatorial + + align:start position:0% +can be generated in a combinatorial + + + align:start position:0% +can be generated in a combinatorial +sense you can make an exhaustive set + + align:start position:0% +sense you can make an exhaustive set + + + align:start position:0% +sense you can make an exhaustive set +now the typically those were made where + + align:start position:0% +now the typically those were made where + + + align:start position:0% +now the typically those were made where +spatially they were isolated each + + align:start position:0% +spatially they were isolated each + + + align:start position:0% +spatially they were isolated each +different + + align:start position:0% + + + + align:start position:0% + +nucleic acid oligonucleotide is present + + align:start position:0% +nucleic acid oligonucleotide is present + + + align:start position:0% +nucleic acid oligonucleotide is present +in a different place identifiable to the + + align:start position:0% +in a different place identifiable to the + + + align:start position:0% +in a different place identifiable to the +computer by its coordinates on a on an + + align:start position:0% +computer by its coordinates on a on an + + + align:start position:0% +computer by its coordinates on a on an +array + + align:start position:0% +array + + + align:start position:0% +array +but you can also make them in a in a big + + align:start position:0% +but you can also make them in a in a big + + + align:start position:0% +but you can also make them in a in a big +mixture and use them as a mixture and do + + align:start position:0% +mixture and use them as a mixture and do + + + align:start position:0% +mixture and use them as a mixture and do +selection on them as we did with the + + align:start position:0% +selection on them as we did with the + + + align:start position:0% +selection on them as we did with the +phage display + + align:start position:0% +phage display + + + align:start position:0% +phage display +or + + align:start position:0% +or + + + align:start position:0% +or +you can make them as a mixture of solid + + align:start position:0% +you can make them as a mixture of solid + + + align:start position:0% +you can make them as a mixture of solid +phase particles and then separate the + + align:start position:0% +phase particles and then separate the + + + align:start position:0% +phase particles and then separate the +polyphase particles out in some manner + + align:start position:0% +polyphase particles out in some manner + + + align:start position:0% +polyphase particles out in some manner +solid phase comes up again and again in + + align:start position:0% +solid phase comes up again and again in + + + align:start position:0% +solid phase comes up again and again in +arrays it's very obvious why you have a + + align:start position:0% +arrays it's very obvious why you have a + + + align:start position:0% +arrays it's very obvious why you have a +solid phase you want to be able to + + align:start position:0% +solid phase you want to be able to + + + align:start position:0% +solid phase you want to be able to +address it by its positions in x and y + + align:start position:0% +address it by its positions in x and y + + + align:start position:0% +address it by its positions in x and y +on the on the array + + align:start position:0% +on the on the array + + + align:start position:0% +on the on the array +but the other reason technical reasons + + align:start position:0% +but the other reason technical reasons + + + align:start position:0% +but the other reason technical reasons +are it's a fantastic way of getting + + align:start position:0% +are it's a fantastic way of getting + + + align:start position:0% +are it's a fantastic way of getting +purification of your products + + align:start position:0% +purification of your products + + + align:start position:0% +purification of your products +by simply by washing + + align:start position:0% +by simply by washing + + + align:start position:0% +by simply by washing +rather than doing complicated + + align:start position:0% +rather than doing complicated + + + align:start position:0% +rather than doing complicated +purification procedures + + align:start position:0% +purification procedures + + + align:start position:0% +purification procedures +and it allows you to in the case of + + align:start position:0% +and it allows you to in the case of + + + align:start position:0% +and it allows you to in the case of +beads they're now you can think of an + + align:start position:0% +beads they're now you can think of an + + + align:start position:0% +beads they're now you can think of an +ultimate and flexible array + + align:start position:0% +ultimate and flexible array + + + align:start position:0% +ultimate and flexible array +it's you can move the beads around and + + align:start position:0% +it's you can move the beads around and + + + align:start position:0% +it's you can move the beads around and +put them in new arrays + + align:start position:0% +put them in new arrays + + + align:start position:0% +put them in new arrays +and identify them later + + align:start position:0% +and identify them later + + + align:start position:0% +and identify them later +anyway so + + align:start position:0% +anyway so + + + align:start position:0% +anyway so +we're going to introduce the general way + + align:start position:0% +we're going to introduce the general way + + + align:start position:0% +we're going to introduce the general way +of making + + align:start position:0% +of making + + + align:start position:0% +of making +either + + align:start position:0% +either + + + align:start position:0% +either +complex chemicals whether they're + + align:start position:0% +complex chemicals whether they're + + + align:start position:0% +complex chemicals whether they're +linear polymers like proteins or nucleic + + align:start position:0% +linear polymers like proteins or nucleic + + + align:start position:0% +linear polymers like proteins or nucleic +acids + + align:start position:0% +acids + + + align:start position:0% +acids +or + + align:start position:0% +or + + + align:start position:0% +or +much more tighter + + align:start position:0% +much more tighter + + + align:start position:0% +much more tighter +and + + align:start position:0% +and + + + align:start position:0% +and +small molecules + + align:start position:0% +small molecules + + + align:start position:0% +small molecules +but they have similar concepts that you + + align:start position:0% +but they have similar concepts that you + + + align:start position:0% +but they have similar concepts that you +need there's a solid phase i already + + align:start position:0% +need there's a solid phase i already + + + align:start position:0% +need there's a solid phase i already +talked about there's the idea of + + align:start position:0% +talked about there's the idea of + + + align:start position:0% +talked about there's the idea of +protection protecting groups + + align:start position:0% +protection protecting groups + + + align:start position:0% +protection protecting groups +such as + + align:start position:0% +such as + + + align:start position:0% +such as +and the protecting groups are protecting + + align:start position:0% +and the protecting groups are protecting + + + align:start position:0% +and the protecting groups are protecting +against a reactive group so the highly + + align:start position:0% +against a reactive group so the highly + + + align:start position:0% +against a reactive group so the highly +reactive group here is the + + align:start position:0% +reactive group here is the + + + align:start position:0% +reactive group here is the +phosphoramidite which is this phosphate + + align:start position:0% +phosphoramidite which is this phosphate + + + align:start position:0% +phosphoramidite which is this phosphate +nitrogen bond + + align:start position:0% +nitrogen bond + + + align:start position:0% +nitrogen bond +this is capable of reacting with just + + align:start position:0% +this is capable of reacting with just + + + align:start position:0% +this is capable of reacting with just +just about uh + + align:start position:0% +just about uh + + + align:start position:0% +just about uh +any uh + + align:start position:0% +any uh + + + align:start position:0% +any uh +nitrogen or oxygen such as this + + align:start position:0% +nitrogen or oxygen such as this + + + align:start position:0% +nitrogen or oxygen such as this +eventually once you deprotect this + + align:start position:0% +eventually once you deprotect this + + + align:start position:0% +eventually once you deprotect this +oxygen at the five prime position + + align:start position:0% +oxygen at the five prime position + + + align:start position:0% +oxygen at the five prime position +remember these two oscillators are five + + align:start position:0% +remember these two oscillators are five + + + align:start position:0% +remember these two oscillators are five +and three just like the ones we talked + + align:start position:0% +and three just like the ones we talked + + + align:start position:0% +and three just like the ones we talked +all along this is the chemical synthesis + + align:start position:0% +all along this is the chemical synthesis + + + align:start position:0% +all along this is the chemical synthesis +version of the polymerase as we've been + + align:start position:0% +version of the polymerase as we've been + + + align:start position:0% +version of the polymerase as we've been +talking about so you have these protect + + align:start position:0% +talking about so you have these protect + + + align:start position:0% +talking about so you have these protect +these reactive groups and then + + align:start position:0% +these reactive groups and then + + + align:start position:0% +these reactive groups and then +protecting groups + + align:start position:0% + + + + align:start position:0% + +and that's those are the major concepts + + align:start position:0% +and that's those are the major concepts + + + align:start position:0% +and that's those are the major concepts +now let's go through this + + align:start position:0% +now let's go through this + + + align:start position:0% +now let's go through this +this is uh + + align:start position:0% +this is uh + + + align:start position:0% +this is uh +the the topic here is + + align:start position:0% +the the topic here is + + + align:start position:0% +the the topic here is +proteins and we'll talk more about + + align:start position:0% +proteins and we'll talk more about + + + align:start position:0% +proteins and we'll talk more about +protein + + align:start position:0% +protein + + + align:start position:0% +protein +synthesis as part of + + align:start position:0% +synthesis as part of + + + align:start position:0% +synthesis as part of +quantitation next time and as part of + + align:start position:0% +quantitation next time and as part of + + + align:start position:0% +quantitation next time and as part of +networks in the last three lectures + + align:start position:0% +networks in the last three lectures + + + align:start position:0% +networks in the last three lectures +but here's a completely synthetic way of + + align:start position:0% +but here's a completely synthetic way of + + + align:start position:0% +but here's a completely synthetic way of +getting it short peptides + + align:start position:0% +getting it short peptides + + + align:start position:0% +getting it short peptides +either by directly synthesizing the + + align:start position:0% +either by directly synthesizing the + + + align:start position:0% +either by directly synthesizing the +peptides or synthesizing nucleic acid + + align:start position:0% +peptides or synthesizing nucleic acid + + + align:start position:0% +peptides or synthesizing nucleic acid +that encodes that peptide or interferes + + align:start position:0% +that encodes that peptide or interferes + + + align:start position:0% +that encodes that peptide or interferes +with the production of that peptide and + + align:start position:0% +with the production of that peptide and + + + align:start position:0% +with the production of that peptide and +you can think of these are drug-like + + align:start position:0% +you can think of these are drug-like + + + align:start position:0% +you can think of these are drug-like +molecules + + align:start position:0% +molecules + + + align:start position:0% +molecules +these are naturally + + align:start position:0% +these are naturally + + + align:start position:0% +these are naturally +related they can be analogs of nucleic + + align:start position:0% +related they can be analogs of nucleic + + + align:start position:0% +related they can be analogs of nucleic +acids and proteins not just straight + + align:start position:0% +acids and proteins not just straight + + + align:start position:0% +acids and proteins not just straight +ones and we'll talk about opportunities + + align:start position:0% +ones and we'll talk about opportunities + + + align:start position:0% +ones and we'll talk about opportunities +for making these analogs + + align:start position:0% +for making these analogs + + + align:start position:0% +for making these analogs +and so by making analogs of known + + align:start position:0% +and so by making analogs of known + + + align:start position:0% +and so by making analogs of known +proteins or nucleic acids you + + align:start position:0% +proteins or nucleic acids you + + + align:start position:0% +proteins or nucleic acids you +kind of have a more immediate connection + + align:start position:0% +kind of have a more immediate connection + + + align:start position:0% +kind of have a more immediate connection +between the thing that your computer + + align:start position:0% +between the thing that your computer + + + align:start position:0% +between the thing that your computer +instructed the synthesizer to make + + align:start position:0% +instructed the synthesizer to make + + + align:start position:0% +instructed the synthesizer to make +and your targets well if you make a + + align:start position:0% +and your targets well if you make a + + + align:start position:0% +and your targets well if you make a +random chemical you don't necessarily + + align:start position:0% +random chemical you don't necessarily + + + align:start position:0% +random chemical you don't necessarily +know what your target is but we'll talk + + align:start position:0% +know what your target is but we'll talk + + + align:start position:0% +know what your target is but we'll talk +about ways of making slightly less + + align:start position:0% +about ways of making slightly less + + + align:start position:0% +about ways of making slightly less +random chemicals but this is one way of + + align:start position:0% +random chemicals but this is one way of + + + align:start position:0% +random chemicals but this is one way of +making a direct connection and the + + align:start position:0% +making a direct connection and the + + + align:start position:0% +making a direct connection and the +processes is + + align:start position:0% +processes is + + + align:start position:0% +processes is +cyclic in the sense that each cycle you + + align:start position:0% +cyclic in the sense that each cycle you + + + align:start position:0% +cyclic in the sense that each cycle you +you return + + align:start position:0% +you return + + + align:start position:0% +you return +and and the polymer gets a little bit + + align:start position:0% +and and the polymer gets a little bit + + + align:start position:0% +and and the polymer gets a little bit +longer you start with one monomer on a + + align:start position:0% +longer you start with one monomer on a + + + align:start position:0% +longer you start with one monomer on a +solid phase shown by these + + align:start position:0% + + + + align:start position:0% + +little hexagons on the far right side of + + align:start position:0% +little hexagons on the far right side of + + + align:start position:0% +little hexagons on the far right side of +the slide and you add + + align:start position:0% +the slide and you add + + + align:start position:0% +the slide and you add +a + + align:start position:0% +a + + + align:start position:0% +a +you you remove the protecting group on + + align:start position:0% +you you remove the protecting group on + + + align:start position:0% +you you remove the protecting group on +the immobilized uh polymer one + + align:start position:0% +the immobilized uh polymer one + + + align:start position:0% +the immobilized uh polymer one +protecting group and then you bring in + + align:start position:0% +protecting group and then you bring in + + + align:start position:0% +protecting group and then you bring in +this reactive group otherwise protected + + align:start position:0% +this reactive group otherwise protected + + + align:start position:0% +this reactive group otherwise protected +and it and there's there's really one + + align:start position:0% +and it and there's there's really one + + + align:start position:0% +and it and there's there's really one +major product you expect you also have + + align:start position:0% +major product you expect you also have + + + align:start position:0% +major product you expect you also have +all the excess you now have it's one + + align:start position:0% +all the excess you now have it's one + + + align:start position:0% +all the excess you now have it's one +longer you d protect this dmt group is + + align:start position:0% +longer you d protect this dmt group is + + + align:start position:0% +longer you d protect this dmt group is +removed + + align:start position:0% +removed + + + align:start position:0% +removed +uh and you go back up and cycle again + + align:start position:0% +uh and you go back up and cycle again + + + align:start position:0% +uh and you go back up and cycle again +there uh there may be additional steps + + align:start position:0% +there uh there may be additional steps + + + align:start position:0% +there uh there may be additional steps +such as oxidation which will stabilize + + align:start position:0% +such as oxidation which will stabilize + + + align:start position:0% +such as oxidation which will stabilize +the new bond that you've made + + align:start position:0% +the new bond that you've made + + + align:start position:0% +the new bond that you've made +or you could have a capping step that + + align:start position:0% +or you could have a capping step that + + + align:start position:0% +or you could have a capping step that +can + + align:start position:0% +can + + + align:start position:0% +can +they can soak up any excess that was + + align:start position:0% +they can soak up any excess that was + + + align:start position:0% +they can soak up any excess that was +left over + + align:start position:0% +left over + + + align:start position:0% +left over +but in general after you're done with + + align:start position:0% +but in general after you're done with + + + align:start position:0% +but in general after you're done with +all these cycles then they'll be + + align:start position:0% +all these cycles then they'll be + + + align:start position:0% +all these cycles then they'll be +there'll be a step where you remove the + + align:start position:0% +there'll be a step where you remove the + + + align:start position:0% +there'll be a step where you remove the +protecting groups altogether and remove + + align:start position:0% +protecting groups altogether and remove + + + align:start position:0% +protecting groups altogether and remove +the polymer from the solid phase if you + + align:start position:0% +the polymer from the solid phase if you + + + align:start position:0% +the polymer from the solid phase if you +so choose or you leave it there if you + + align:start position:0% +so choose or you leave it there if you + + + align:start position:0% +so choose or you leave it there if you +have an array + + align:start position:0% +have an array + + + align:start position:0% +have an array +these are + + align:start position:0% +these are + + + align:start position:0% +these are +other examples of protecting groups + + align:start position:0% +other examples of protecting groups + + + align:start position:0% +other examples of protecting groups +these are now on the bases some bases + + align:start position:0% +these are now on the bases some bases + + + align:start position:0% +these are now on the bases some bases +don't need protection like thymines + + align:start position:0% +don't need protection like thymines + + + align:start position:0% +don't need protection like thymines +if you have an exocyclic amine then you + + align:start position:0% +if you have an exocyclic amine then you + + + align:start position:0% +if you have an exocyclic amine then you +typically need a benzoyl or isobutyl + + align:start position:0% +typically need a benzoyl or isobutyl + + + align:start position:0% +typically need a benzoyl or isobutyl +group in blue here + + align:start position:0% +group in blue here + + + align:start position:0% +group in blue here +are the protecting groups + + align:start position:0% + + + + align:start position:0% + +i said that there's the + + align:start position:0% +i said that there's the + + + align:start position:0% +i said that there's the +there's an opportunity here for + + align:start position:0% +there's an opportunity here for + + + align:start position:0% +there's an opportunity here for +having uh modifying the elite the olym + + align:start position:0% +having uh modifying the elite the olym + + + align:start position:0% +having uh modifying the elite the olym +nucleotides or oligopeptides or other + + align:start position:0% +nucleotides or oligopeptides or other + + + align:start position:0% +nucleotides or oligopeptides or other +chemicals + + align:start position:0% + + + + align:start position:0% + +to make them so that they're uh + + align:start position:0% +to make them so that they're uh + + + align:start position:0% +to make them so that they're uh +related to but not + + align:start position:0% +related to but not + + + align:start position:0% +related to but not +identical in every property + + align:start position:0% +identical in every property + + + align:start position:0% +identical in every property +to uh + + align:start position:0% +to uh + + + align:start position:0% +to uh +normal + + align:start position:0% +normal + + + align:start position:0% +normal +constituents of your body or of the + + align:start position:0% +constituents of your body or of the + + + align:start position:0% +constituents of your body or of the +bacterial cell + + align:start position:0% +bacterial cell + + + align:start position:0% +bacterial cell +that you're aiming at and why would you + + align:start position:0% +that you're aiming at and why would you + + + align:start position:0% +that you're aiming at and why would you +want to make derivatives why not make + + align:start position:0% +want to make derivatives why not make + + + align:start position:0% +want to make derivatives why not make +the exact thing and the reason you want + + align:start position:0% +the exact thing and the reason you want + + + align:start position:0% +the exact thing and the reason you want +to make derivatives would be for example + + align:start position:0% +to make derivatives would be for example + + + align:start position:0% +to make derivatives would be for example +to increase their stability or decrease + + align:start position:0% +to increase their stability or decrease + + + align:start position:0% +to increase their stability or decrease +their stability + + align:start position:0% +their stability + + + align:start position:0% +their stability +or + + align:start position:0% +or + + + align:start position:0% +or +make them bind more + + align:start position:0% +make them bind more + + + align:start position:0% +make them bind more +faster or more irreversibly and examples + + align:start position:0% +faster or more irreversibly and examples + + + align:start position:0% +faster or more irreversibly and examples +are in the previous slide you can make + + align:start position:0% +are in the previous slide you can make + + + align:start position:0% +are in the previous slide you can make +modified bases and in slide 29 here you + + align:start position:0% +modified bases and in slide 29 here you + + + align:start position:0% +modified bases and in slide 29 here you +can change the backbone itself you can + + align:start position:0% +can change the backbone itself you can + + + align:start position:0% +can change the backbone itself you can +change the riboses so that they have + + align:start position:0% +change the riboses so that they have + + + align:start position:0% +change the riboses so that they have +bulky groups that prevent the nucleases + + align:start position:0% +bulky groups that prevent the nucleases + + + align:start position:0% +bulky groups that prevent the nucleases +from getting in or they could have + + align:start position:0% +from getting in or they could have + + + align:start position:0% +from getting in or they could have +exchanged oxygen for sulfurs or + + align:start position:0% +exchanged oxygen for sulfurs or + + + align:start position:0% +exchanged oxygen for sulfurs or +hydrogens + + align:start position:0% + + + + align:start position:0% + +in order to make the + + align:start position:0% +in order to make the + + + align:start position:0% +in order to make the +phosphodiester backbone itself which is + + align:start position:0% +phosphodiester backbone itself which is + + + align:start position:0% +phosphodiester backbone itself which is +where nucleus is cleaved + + align:start position:0% +where nucleus is cleaved + + + align:start position:0% +where nucleus is cleaved +a less + + align:start position:0% +a less + + + align:start position:0% +a less +attractive less + + align:start position:0% +attractive less + + + align:start position:0% +attractive less +energetically favorable substrate + + align:start position:0% +energetically favorable substrate + + + align:start position:0% +energetically favorable substrate +okay so now those are + + align:start position:0% +okay so now those are + + + align:start position:0% +okay so now those are +chemical processes that in a certain + + align:start position:0% +chemical processes that in a certain + + + align:start position:0% +chemical processes that in a certain +sense mimic the normal polymerases and + + align:start position:0% +sense mimic the normal polymerases and + + + align:start position:0% +sense mimic the normal polymerases and +ribosomes in the cell + + align:start position:0% +ribosomes in the cell + + + align:start position:0% +ribosomes in the cell +and there are analogous processes to + + align:start position:0% +and there are analogous processes to + + + align:start position:0% +and there are analogous processes to +generate chemical diversity + + align:start position:0% +generate chemical diversity + + + align:start position:0% +generate chemical diversity +on smaller molecules + + align:start position:0% +on smaller molecules + + + align:start position:0% +on smaller molecules +and and then there are + + align:start position:0% +and and then there are + + + align:start position:0% +and and then there are +an analogous to that + + align:start position:0% +an analogous to that + + + align:start position:0% +an analogous to that +biological mechanisms by which you can + + align:start position:0% +biological mechanisms by which you can + + + align:start position:0% +biological mechanisms by which you can +make uh + + align:start position:0% +make uh + + + align:start position:0% +make uh +small molecule diversity which are less + + align:start position:0% +small molecule diversity which are less + + + align:start position:0% +small molecule diversity which are less +cyclic + + align:start position:0% +cyclic + + + align:start position:0% +cyclic +than uh + + align:start position:0% +than uh + + + align:start position:0% +than uh +the processes we just talked about these + + align:start position:0% +the processes we just talked about these + + + align:start position:0% +the processes we just talked about these +are these are more + + align:start position:0% +are these are more + + + align:start position:0% +are these are more +uh a + + align:start position:0% + + + + align:start position:0% + +set of ordered reactions + + align:start position:0% +set of ordered reactions + + + align:start position:0% +set of ordered reactions +that has a conceptual repeat + + align:start position:0% +that has a conceptual repeat + + + align:start position:0% +that has a conceptual repeat +but in a sense you can think of it as a + + align:start position:0% +but in a sense you can think of it as a + + + align:start position:0% +but in a sense you can think of it as a +linear uh program that you go from + + align:start position:0% +linear uh program that you go from + + + align:start position:0% +linear uh program that you go from +beginning to the end and that's to make + + align:start position:0% +beginning to the end and that's to make + + + align:start position:0% +beginning to the end and that's to make +these uh + + align:start position:0% +these uh + + + align:start position:0% +these uh +polyketides which are shown on the + + align:start position:0% +polyketides which are shown on the + + + align:start position:0% +polyketides which are shown on the +right-hand side of the slide a large + + align:start position:0% +right-hand side of the slide a large + + + align:start position:0% +right-hand side of the slide a large +class of + + align:start position:0% +class of + + + align:start position:0% +class of +pharmaceuticals including most of the + + align:start position:0% +pharmaceuticals including most of the + + + align:start position:0% +pharmaceuticals including most of the +antibiotics are made by a fairly small + + align:start position:0% +antibiotics are made by a fairly small + + + align:start position:0% +antibiotics are made by a fairly small +set of organisms such as streptomyces + + align:start position:0% +set of organisms such as streptomyces + + + align:start position:0% +set of organisms such as streptomyces +and certain plants + + align:start position:0% +and certain plants + + + align:start position:0% +and certain plants +and + + align:start position:0% +and + + + align:start position:0% +and +this process which is made which will be + + align:start position:0% +this process which is made which will be + + + align:start position:0% +this process which is made which will be +illustrated in more detail in the next + + align:start position:0% +illustrated in more detail in the next + + + align:start position:0% +illustrated in more detail in the next +slide is very akin to fatty acid + + align:start position:0% +slide is very akin to fatty acid + + + align:start position:0% +slide is very akin to fatty acid +synthesis fatty acids are long + + align:start position:0% +synthesis fatty acids are long + + + align:start position:0% +synthesis fatty acids are long +hydrocarbon chains which you can think + + align:start position:0% +hydrocarbon chains which you can think + + + align:start position:0% +hydrocarbon chains which you can think +of adding each + + align:start position:0% +of adding each + + + align:start position:0% +of adding each +two carbons on that fatty acid as a + + align:start position:0% +two carbons on that fatty acid as a + + + align:start position:0% +two carbons on that fatty acid as a +process akin to the one for making these + + align:start position:0% +process akin to the one for making these + + + align:start position:0% +process akin to the one for making these +polyketide drug like molecules + + align:start position:0% +polyketide drug like molecules + + + align:start position:0% +polyketide drug like molecules +another way of making a biologically + + align:start position:0% +another way of making a biologically + + + align:start position:0% +another way of making a biologically +making a very compact structure + + align:start position:0% +making a very compact structure + + + align:start position:0% +making a very compact structure +which actually uses uh + + align:start position:0% +which actually uses uh + + + align:start position:0% +which actually uses uh +ribosomes but it uses them to make + + align:start position:0% +ribosomes but it uses them to make + + + align:start position:0% +ribosomes but it uses them to make +very + + align:start position:0% +very + + + align:start position:0% +very +tight + + align:start position:0% +tight + + + align:start position:0% +tight +short peptides and a precursor that then + + align:start position:0% +short peptides and a precursor that then + + + align:start position:0% +short peptides and a precursor that then +fold with dice lots of disulfides to + + align:start position:0% +fold with dice lots of disulfides to + + + align:start position:0% +fold with dice lots of disulfides to +make this uh + + align:start position:0% +make this uh + + + align:start position:0% +make this uh +small it's small and highly cross-linked + + align:start position:0% +small it's small and highly cross-linked + + + align:start position:0% +small it's small and highly cross-linked +now the fact that that is that these + + align:start position:0% +now the fact that that is that these + + + align:start position:0% +now the fact that that is that these +cone snails have gone + + align:start position:0% +cone snails have gone + + + align:start position:0% +cone snails have gone +have gone to the trouble making hundreds + + align:start position:0% +have gone to the trouble making hundreds + + + align:start position:0% +have gone to the trouble making hundreds +of these different uh very small + + align:start position:0% +of these different uh very small + + + align:start position:0% +of these different uh very small +peptides of that have these properties + + align:start position:0% +peptides of that have these properties + + + align:start position:0% +peptides of that have these properties +um tells you something about what it is + + align:start position:0% +um tells you something about what it is + + + align:start position:0% +um tells you something about what it is +that you want that that drug-like + + align:start position:0% +that you want that that drug-like + + + align:start position:0% +that you want that that drug-like +molecules have in common and that is + + align:start position:0% +molecules have in common and that is + + + align:start position:0% +molecules have in common and that is +they they're small so they diffuse + + align:start position:0% +they they're small so they diffuse + + + align:start position:0% +they they're small so they diffuse +quickly + + align:start position:0% +quickly + + + align:start position:0% +quickly +and get to their their site and so you + + align:start position:0% +and get to their their site and so you + + + align:start position:0% +and get to their their site and so you +can have large amounts of them in a + + align:start position:0% +can have large amounts of them in a + + + align:start position:0% +can have large amounts of them in a +small space so you can manufacture lots + + align:start position:0% +small space so you can manufacture lots + + + align:start position:0% +small space so you can manufacture lots +of them + + align:start position:0% +of them + + + align:start position:0% +of them +and and they're then they have to be + + align:start position:0% +and and they're then they have to be + + + align:start position:0% +and and they're then they have to be +highly cross-length in order to maintain + + align:start position:0% +highly cross-length in order to maintain + + + align:start position:0% +highly cross-length in order to maintain +the rigidity because they're small they + + align:start position:0% +the rigidity because they're small they + + + align:start position:0% +the rigidity because they're small they +have less surface area to bind to their + + align:start position:0% +have less surface area to bind to their + + + align:start position:0% +have less surface area to bind to their +their + + align:start position:0% +their + + + align:start position:0% +their +binding pocket so to compensate for that + + align:start position:0% +binding pocket so to compensate for that + + + align:start position:0% +binding pocket so to compensate for that +they have to have a lot of rigidity and + + align:start position:0% +they have to have a lot of rigidity and + + + align:start position:0% +they have to have a lot of rigidity and +the thing that you lock in rigidly has + + align:start position:0% +the thing that you lock in rigidly has + + + align:start position:0% +the thing that you lock in rigidly has +to be the correct structure it does you + + align:start position:0% +to be the correct structure it does you + + + align:start position:0% +to be the correct structure it does you +no good to have a rigid structure that + + align:start position:0% +no good to have a rigid structure that + + + align:start position:0% +no good to have a rigid structure that +isn't really perfectly complementary to + + align:start position:0% +isn't really perfectly complementary to + + + align:start position:0% +isn't really perfectly complementary to +that surface + + align:start position:0% +that surface + + + align:start position:0% +that surface +and the third source of biological + + align:start position:0% +and the third source of biological + + + align:start position:0% +and the third source of biological +diversity + + align:start position:0% +diversity + + + align:start position:0% +diversity +is one you're probably more familiar + + align:start position:0% +is one you're probably more familiar + + + align:start position:0% +is one you're probably more familiar +with which is the immune receptors the + + align:start position:0% +with which is the immune receptors the + + + align:start position:0% +with which is the immune receptors the +bnt cell receptors the antibodies + + align:start position:0% +bnt cell receptors the antibodies + + + align:start position:0% +bnt cell receptors the antibodies +and cell mediated immunity + + align:start position:0% +and cell mediated immunity + + + align:start position:0% +and cell mediated immunity +and these + + align:start position:0% +and these + + + align:start position:0% +and these +use + + align:start position:0% +use + + + align:start position:0% +use +um + + align:start position:0% +um + + + align:start position:0% +um +a recombinational machinery + + align:start position:0% +a recombinational machinery + + + align:start position:0% +a recombinational machinery +to to to to program + + align:start position:0% +to to to to program + + + align:start position:0% +to to to to program +various combinations of + + align:start position:0% +various combinations of + + + align:start position:0% +various combinations of +nucleic acid motifs that encode protein + + align:start position:0% +nucleic acid motifs that encode protein + + + align:start position:0% +nucleic acid motifs that encode protein +motifs and as they do that recombination + + align:start position:0% +motifs and as they do that recombination + + + align:start position:0% +motifs and as they do that recombination +they have further diversification that + + align:start position:0% +they have further diversification that + + + align:start position:0% +they have further diversification that +occurs due to a template-independent + + align:start position:0% +occurs due to a template-independent + + + align:start position:0% +occurs due to a template-independent +polymerase + + align:start position:0% +polymerase + + + align:start position:0% +polymerase +thermal transference which will extend a + + align:start position:0% +thermal transference which will extend a + + + align:start position:0% +thermal transference which will extend a +few nucleotides a completely random + + align:start position:0% +few nucleotides a completely random + + + align:start position:0% +few nucleotides a completely random +nucleic acid sequence + + align:start position:0% +nucleic acid sequence + + + align:start position:0% +nucleic acid sequence +that that allow that basically + + align:start position:0% +that that allow that basically + + + align:start position:0% +that that allow that basically +incredibly accelerates the the rate of + + align:start position:0% +incredibly accelerates the the rate of + + + align:start position:0% +incredibly accelerates the the rate of +mutagenesis basically generating + + align:start position:0% +mutagenesis basically generating + + + align:start position:0% +mutagenesis basically generating +sequence de novo this is one of the + + align:start position:0% +sequence de novo this is one of the + + + align:start position:0% +sequence de novo this is one of the +examples in biology where you generate + + align:start position:0% +examples in biology where you generate + + + align:start position:0% +examples in biology where you generate +sequence de novo and i think that's + + align:start position:0% +sequence de novo and i think that's + + + align:start position:0% +sequence de novo and i think that's +very apropos of this + + align:start position:0% +very apropos of this + + + align:start position:0% +very apropos of this +combinatorial topic + + align:start position:0% +combinatorial topic + + + align:start position:0% +combinatorial topic +now this is + + align:start position:0% +now this is + + + align:start position:0% +now this is +a beautiful example from the previous + + align:start position:0% +a beautiful example from the previous + + + align:start position:0% +a beautiful example from the previous +slide those poly keypads on the far + + align:start position:0% +slide those poly keypads on the far + + + align:start position:0% +slide those poly keypads on the far +right now are the star of this slide + + align:start position:0% +right now are the star of this slide + + + align:start position:0% +right now are the star of this slide +and here in a certain sense nature has + + align:start position:0% +and here in a certain sense nature has + + + align:start position:0% +and here in a certain sense nature has +and now scientists have engineered + + align:start position:0% +and now scientists have engineered + + + align:start position:0% +and now scientists have engineered +protein modules to make + + align:start position:0% +protein modules to make + + + align:start position:0% +protein modules to make +these uh this linear sequence of events + + align:start position:0% +these uh this linear sequence of events + + + align:start position:0% +these uh this linear sequence of events +you can think of here you're using a a + + align:start position:0% +you can think of here you're using a a + + + align:start position:0% +you can think of here you're using a a +linear + + align:start position:0% +linear + + + align:start position:0% +linear +set of protein domains + + align:start position:0% +set of protein domains + + + align:start position:0% +set of protein domains +to program very complicated series of + + align:start position:0% +to program very complicated series of + + + align:start position:0% +to program very complicated series of +chemical reactions the same way the + + align:start position:0% +chemical reactions the same way the + + + align:start position:0% +chemical reactions the same way the +linear sequence of messenger rna + + align:start position:0% +linear sequence of messenger rna + + + align:start position:0% +linear sequence of messenger rna +tells the ribosome to make a series of + + align:start position:0% +tells the ribosome to make a series of + + + align:start position:0% +tells the ribosome to make a series of +additions in the protein the ribose the + + align:start position:0% +additions in the protein the ribose the + + + align:start position:0% +additions in the protein the ribose the +ribosome cycle catalytic cycle is is a + + align:start position:0% +ribosome cycle catalytic cycle is is a + + + align:start position:0% +ribosome cycle catalytic cycle is is a +cycle while this is more a linear tape a + + align:start position:0% +cycle while this is more a linear tape a + + + align:start position:0% +cycle while this is more a linear tape a +linear series of events the proteins + + align:start position:0% +linear series of events the proteins + + + align:start position:0% +linear series of events the proteins +themselves these little arrow shaped + + align:start position:0% +themselves these little arrow shaped + + + align:start position:0% +themselves these little arrow shaped +things little boxes in them along the + + align:start position:0% +things little boxes in them along the + + + align:start position:0% +things little boxes in them along the +top + + align:start position:0% +top + + + align:start position:0% +top +uh labeled module one through six + + align:start position:0% +uh labeled module one through six + + + align:start position:0% +uh labeled module one through six +those proteins are of course made on + + align:start position:0% +those proteins are of course made on + + + align:start position:0% +those proteins are of course made on +ribosomes but then + + align:start position:0% +ribosomes but then + + + align:start position:0% +ribosomes but then +they act kind of like the solid phase + + align:start position:0% +they act kind of like the solid phase + + + align:start position:0% +they act kind of like the solid phase +synthesis where the acyl carrier protein + + align:start position:0% +synthesis where the acyl carrier protein + + + align:start position:0% +synthesis where the acyl carrier protein +acp in the box binds to the + + align:start position:0% +acp in the box binds to the + + + align:start position:0% +acp in the box binds to the +the first monomer and it starts + + align:start position:0% +the first monomer and it starts + + + align:start position:0% +the first monomer and it starts +transferring it from + + align:start position:0% +transferring it from + + + align:start position:0% +transferring it from +protein to protein along this + + align:start position:0% +protein to protein along this + + + align:start position:0% +protein to protein along this +multi-domain + + align:start position:0% +multi-domain + + + align:start position:0% +multi-domain +huge protein + + align:start position:0% +huge protein + + + align:start position:0% +huge protein +and there's actually three proteins in a + + align:start position:0% +and there's actually three proteins in a + + + align:start position:0% +and there's actually three proteins in a +row here and each of the steps are taken + + align:start position:0% +row here and each of the steps are taken + + + align:start position:0% +row here and each of the steps are taken +in order along the protein and they + + align:start position:0% +in order along the protein and they + + + align:start position:0% +in order along the protein and they +involve things like a synthase step + + align:start position:0% +involve things like a synthase step + + + align:start position:0% +involve things like a synthase step +where you'll bring in another monomer or + + align:start position:0% +where you'll bring in another monomer or + + + align:start position:0% +where you'll bring in another monomer or +a keto reductase step kr or you'll bring + + align:start position:0% +a keto reductase step kr or you'll bring + + + align:start position:0% +a keto reductase step kr or you'll bring +in uh or you're where you would reduce + + align:start position:0% +in uh or you're where you would reduce + + + align:start position:0% +in uh or you're where you would reduce +uh one of the double bonds + + align:start position:0% +uh one of the double bonds + + + align:start position:0% +uh one of the double bonds +or uh + + align:start position:0% +or uh + + + align:start position:0% +or uh +an acyl transfer a step a t + + align:start position:0% +an acyl transfer a step a t + + + align:start position:0% +an acyl transfer a step a t +and so + + align:start position:0% +and so + + + align:start position:0% +and so +and then you + + align:start position:0% +and then you + + + align:start position:0% +and then you +but you can see each of these has a + + align:start position:0% +but you can see each of these has a + + + align:start position:0% +but you can see each of these has a +substrate specificity and by changing + + align:start position:0% +substrate specificity and by changing + + + align:start position:0% +substrate specificity and by changing +the order of substrate specificities you + + align:start position:0% +the order of substrate specificities you + + + align:start position:0% +the order of substrate specificities you +can build up a huge combinatorial + + align:start position:0% +can build up a huge combinatorial + + + align:start position:0% +can build up a huge combinatorial +collection here + + align:start position:0% +collection here + + + align:start position:0% +collection here +in + + align:start position:0% + + + + align:start position:0% + +microbial communities and also in the + + align:start position:0% +microbial communities and also in the + + + align:start position:0% +microbial communities and also in the +laboratory + + align:start position:0% +laboratory + + + align:start position:0% +laboratory +now protein interaction + + align:start position:0% +now protein interaction + + + align:start position:0% +now protein interaction +we're just beginning + + align:start position:0% +we're just beginning + + + align:start position:0% +we're just beginning +to talk seriously about protein + + align:start position:0% +to talk seriously about protein + + + align:start position:0% +to talk seriously about protein +interaction assays + + align:start position:0% +interaction assays + + + align:start position:0% +interaction assays +i think many of you + + align:start position:0% +i think many of you + + + align:start position:0% +i think many of you +either are or will be more and more + + align:start position:0% +either are or will be more and more + + + align:start position:0% +either are or will be more and more +familiar with the + + align:start position:0% +familiar with the + + + align:start position:0% +familiar with the +protein interaction assays in next class + + align:start position:0% +protein interaction assays in next class + + + align:start position:0% +protein interaction assays in next class +we'll talk about + + align:start position:0% +we'll talk about + + + align:start position:0% +we'll talk about +ways of getting direct information on + + align:start position:0% +ways of getting direct information on + + + align:start position:0% +ways of getting direct information on +protein through through cross-linking + + align:start position:0% +protein through through cross-linking + + + align:start position:0% +protein through through cross-linking +and mass spectrometry another way is + + align:start position:0% +and mass spectrometry another way is + + + align:start position:0% +and mass spectrometry another way is +indirectly setting up these reporter + + align:start position:0% +indirectly setting up these reporter + + + align:start position:0% +indirectly setting up these reporter +assays where you take advantage of the + + align:start position:0% +assays where you take advantage of the + + + align:start position:0% +assays where you take advantage of the +binding properties of known proteins to + + align:start position:0% +binding properties of known proteins to + + + align:start position:0% +binding properties of known proteins to +analyze two unknown proteins + + align:start position:0% +analyze two unknown proteins + + + align:start position:0% +analyze two unknown proteins +and so a known protein might be lexa + + align:start position:0% +and so a known protein might be lexa + + + align:start position:0% +and so a known protein might be lexa +which binds to dna + + align:start position:0% +which binds to dna + + + align:start position:0% +which binds to dna +and b42 which activates transcription of + + align:start position:0% +and b42 which activates transcription of + + + align:start position:0% +and b42 which activates transcription of +something for which you have a good uh + + align:start position:0% +something for which you have a good uh + + + align:start position:0% +something for which you have a good uh +visual assay i hear a three + + align:start position:0% +visual assay i hear a three + + + align:start position:0% +visual assay i hear a three +um life and death + + align:start position:0% +um life and death + + + align:start position:0% +um life and death +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +and by taking these two knowns lexa and + + align:start position:0% +and by taking these two knowns lexa and + + + align:start position:0% +and by taking these two knowns lexa and +b42 which have known properties + + align:start position:0% +b42 which have known properties + + + align:start position:0% +b42 which have known properties +but they only + + align:start position:0% +but they only + + + align:start position:0% +but they only +exert their properties when they're + + align:start position:0% +exert their properties when they're + + + align:start position:0% +exert their properties when they're +brought together and they're only + + align:start position:0% +brought together and they're only + + + align:start position:0% +brought together and they're only +brought together if the unknown proteins + + align:start position:0% +brought together if the unknown proteins + + + align:start position:0% +brought together if the unknown proteins +or partially known proteins to which + + align:start position:0% +or partially known proteins to which + + + align:start position:0% +or partially known proteins to which +they're bound interact with each other + + align:start position:0% +they're bound interact with each other + + + align:start position:0% +they're bound interact with each other +okay and so this this is a so-called two + + align:start position:0% +okay and so this this is a so-called two + + + align:start position:0% +okay and so this this is a so-called two +hybrid assay + + align:start position:0% +hybrid assay + + + align:start position:0% +hybrid assay +and the variations on it i think we + + align:start position:0% +and the variations on it i think we + + + align:start position:0% +and the variations on it i think we +mentioned one um + + align:start position:0% +mentioned one um + + + align:start position:0% +mentioned one um +where you can characterize nucleic acid + + align:start position:0% +where you can characterize nucleic acid + + + align:start position:0% +where you can characterize nucleic acid +protein reactions with a one hybrid + + align:start position:0% +protein reactions with a one hybrid + + + align:start position:0% +protein reactions with a one hybrid +assay and here you can inhibit this this + + align:start position:0% +assay and here you can inhibit this this + + + align:start position:0% +assay and here you can inhibit this this +this interaction between the two + + align:start position:0% +this interaction between the two + + + align:start position:0% +this interaction between the two +knowns uh sorry unknowns or partially + + align:start position:0% +knowns uh sorry unknowns or partially + + + align:start position:0% +knowns uh sorry unknowns or partially +known molecules in blue here + + align:start position:0% +known molecules in blue here + + + align:start position:0% +known molecules in blue here +uh here's a + + align:start position:0% + + + + align:start position:0% + +tgf beta a growth factor and a binding + + align:start position:0% +tgf beta a growth factor and a binding + + + align:start position:0% +tgf beta a growth factor and a binding +protein you can inhibit that with a + + align:start position:0% +protein you can inhibit that with a + + + align:start position:0% +protein you can inhibit that with a +particularly small molecule or a + + align:start position:0% +particularly small molecule or a + + + align:start position:0% +particularly small molecule or a +collection of small molecules which can + + align:start position:0% +collection of small molecules which can + + + align:start position:0% +collection of small molecules which can +be introduced from one of these + + align:start position:0% +be introduced from one of these + + + align:start position:0% +be introduced from one of these +combinatorial synthesis + + align:start position:0% +combinatorial synthesis + + + align:start position:0% +combinatorial synthesis +into an array of of these cellular + + align:start position:0% +into an array of of these cellular + + + align:start position:0% +into an array of of these cellular +assays and you get these + + align:start position:0% +assays and you get these + + + align:start position:0% +assays and you get these +information about + + align:start position:0% +information about + + + align:start position:0% +information about +you can either collect a big data set of + + align:start position:0% +you can either collect a big data set of + + + align:start position:0% +you can either collect a big data set of +proteins that interact + + align:start position:0% +proteins that interact + + + align:start position:0% +proteins that interact +from a proteomic scale experiment or + + align:start position:0% +from a proteomic scale experiment or + + + align:start position:0% +from a proteomic scale experiment or +small molecules that inhibit one or more + + align:start position:0% +small molecules that inhibit one or more + + + align:start position:0% +small molecules that inhibit one or more +of those interactions + + align:start position:0% +of those interactions + + + align:start position:0% +of those interactions +this is a source of information + + align:start position:0% +this is a source of information + + + align:start position:0% +this is a source of information +which is intrinsically computational in + + align:start position:0% +which is intrinsically computational in + + + align:start position:0% +which is intrinsically computational in +the sense well since there's a large + + align:start position:0% +the sense well since there's a large + + + align:start position:0% +the sense well since there's a large +amount of it you can model the + + align:start position:0% +amount of it you can model the + + + align:start position:0% +amount of it you can model the +three-dimensional structure of this + + align:start position:0% +three-dimensional structure of this + + + align:start position:0% +three-dimensional structure of this +interaction if you have sufficient data + + align:start position:0% +interaction if you have sufficient data + + + align:start position:0% +interaction if you have sufficient data +to do that and you can model the impact + + align:start position:0% +to do that and you can model the impact + + + align:start position:0% +to do that and you can model the impact +of the small molecules in a structure + + align:start position:0% +of the small molecules in a structure + + + align:start position:0% +of the small molecules in a structure +activity sense + + align:start position:0% +activity sense + + + align:start position:0% +activity sense +now if you look at + + align:start position:0% +now if you look at + + + align:start position:0% +now if you look at +the + + align:start position:0% +the + + + align:start position:0% +the +top right hand part of slide 34 here you + + align:start position:0% +top right hand part of slide 34 here you + + + align:start position:0% +top right hand part of slide 34 here you +can see this huge diversity of all these + + align:start position:0% +can see this huge diversity of all these + + + align:start position:0% +can see this huge diversity of all these +different colored shapes + + align:start position:0% +different colored shapes + + + align:start position:0% +different colored shapes +and + + align:start position:0% +and + + + align:start position:0% +and +if you wanted to if you wanted to use + + align:start position:0% +if you wanted to if you wanted to use + + + align:start position:0% +if you wanted to if you wanted to use +these in a combinatorial asset you'd + + align:start position:0% +these in a combinatorial asset you'd + + + align:start position:0% +these in a combinatorial asset you'd +connect them in every pairwise + + align:start position:0% +connect them in every pairwise + + + align:start position:0% +connect them in every pairwise +combination and try them against your + + align:start position:0% +combination and try them against your + + + align:start position:0% +combination and try them against your +target by some bioassay + + align:start position:0% +target by some bioassay + + + align:start position:0% +target by some bioassay +however that library is too large + + align:start position:0% +however that library is too large + + + align:start position:0% +however that library is too large +either to make or to screen typically + + align:start position:0% +either to make or to screen typically + + + align:start position:0% +either to make or to screen typically +the screen and what you can do is you + + align:start position:0% +the screen and what you can do is you + + + align:start position:0% +the screen and what you can do is you +can study + + align:start position:0% +can study + + + align:start position:0% +can study +a part of the molecule + + align:start position:0% +a part of the molecule + + + align:start position:0% +a part of the molecule +and see and then take the subset of the + + align:start position:0% +and see and then take the subset of the + + + align:start position:0% +and see and then take the subset of the +diversity that that that can bind + + align:start position:0% +diversity that that that can bind + + + align:start position:0% +diversity that that that can bind +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +uh and then take that subset + + align:start position:0% +uh and then take that subset + + + align:start position:0% +uh and then take that subset +characterize it and now make every only + + align:start position:0% +characterize it and now make every only + + + align:start position:0% +characterize it and now make every only +the pairwise combinations of the two + + align:start position:0% +the pairwise combinations of the two + + + align:start position:0% +the pairwise combinations of the two +half molecules + + align:start position:0% +half molecules + + + align:start position:0% +half molecules +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +generally speaking + + align:start position:0% +generally speaking + + + align:start position:0% +generally speaking +if the if the geometry is fairly + + align:start position:0% +if the if the geometry is fairly + + + align:start position:0% +if the if the geometry is fairly +rigid + + align:start position:0% +rigid + + + align:start position:0% +rigid +then the binding constant + + align:start position:0% +then the binding constant + + + align:start position:0% +then the binding constant +will get + + align:start position:0% +will get + + + align:start position:0% +will get +will be roughly the product of the two + + align:start position:0% +will be roughly the product of the two + + + align:start position:0% +will be roughly the product of the two +binding constants so if each one is has + + align:start position:0% +binding constants so if each one is has + + + align:start position:0% +binding constants so if each one is has +a very low binding constant then it will + + align:start position:0% +a very low binding constant then it will + + + align:start position:0% +a very low binding constant then it will +be you know roughly the square of that + + align:start position:0% +be you know roughly the square of that + + + align:start position:0% +be you know roughly the square of that +and you get um + + align:start position:0% +and you get um + + + align:start position:0% +and you get um +some point of diminishing returns + + align:start position:0% +some point of diminishing returns + + + align:start position:0% +some point of diminishing returns +eventually + + align:start position:0% +eventually + + + align:start position:0% +eventually +so this is an example of a strategy + + align:start position:0% +so this is an example of a strategy + + + align:start position:0% +so this is an example of a strategy +where use a little bit of prior + + align:start position:0% +where use a little bit of prior + + + align:start position:0% +where use a little bit of prior +knowledge + + align:start position:0% +knowledge + + + align:start position:0% +knowledge +which can be + + align:start position:0% +which can be + + + align:start position:0% +which can be +empirical or could be purely + + align:start position:0% +empirical or could be purely + + + align:start position:0% +empirical or could be purely +computational about how to limit your + + align:start position:0% +computational about how to limit your + + + align:start position:0% +computational about how to limit your +library and make interesting + + align:start position:0% +library and make interesting + + + align:start position:0% +library and make interesting +combinations + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now that we've been talking mainly about + + align:start position:0% +now that we've been talking mainly about + + + align:start position:0% +now that we've been talking mainly about +the kind of chemical diversity we can + + align:start position:0% +the kind of chemical diversity we can + + + align:start position:0% +the kind of chemical diversity we can +get it's aimed at the ligands that + + align:start position:0% +get it's aimed at the ligands that + + + align:start position:0% +get it's aimed at the ligands that +combine to target proteins but now we + + align:start position:0% +combine to target proteins but now we + + + align:start position:0% +combine to target proteins but now we +want to talk about + + align:start position:0% +want to talk about + + + align:start position:0% +want to talk about +the source of information about those + + align:start position:0% +the source of information about those + + + align:start position:0% +the source of information about those +target proteins itself which is another + + align:start position:0% +target proteins itself which is another + + + align:start position:0% +target proteins itself which is another +genomics project + + align:start position:0% +genomics project + + + align:start position:0% +genomics project +a + + align:start position:0% +a + + + align:start position:0% +a +structural genomics + + align:start position:0% +structural genomics + + + align:start position:0% +structural genomics +and typically + + align:start position:0% +and typically + + + align:start position:0% +and typically +we want to + + align:start position:0% +we want to + + + align:start position:0% +we want to +select targets + + align:start position:0% +select targets + + + align:start position:0% +select targets +for binding drugs or select targets + + align:start position:0% +for binding drugs or select targets + + + align:start position:0% +for binding drugs or select targets +for solving the structures of proteins + + align:start position:0% +for solving the structures of proteins + + + align:start position:0% +for solving the structures of proteins +in order to + + align:start position:0% +in order to + + + align:start position:0% +in order to +look at their ligands in more detail + + align:start position:0% +look at their ligands in more detail + + + align:start position:0% +look at their ligands in more detail +and + + align:start position:0% +and + + + align:start position:0% +and +how can we do this how can we decide + + align:start position:0% +how can we do this how can we decide + + + align:start position:0% +how can we do this how can we decide +which targets are high on our list to go + + align:start position:0% +which targets are high on our list to go + + + align:start position:0% +which targets are high on our list to go +for next we have hundreds of proteins + + align:start position:0% +for next we have hundreds of proteins + + + align:start position:0% +for next we have hundreds of proteins +for which we have three dimensional + + align:start position:0% +for which we have three dimensional + + + align:start position:0% +for which we have three dimensional +structures + + align:start position:0% +structures + + + align:start position:0% +structures +and + + align:start position:0% +and + + + align:start position:0% +and +from some of them we have + + align:start position:0% +from some of them we have + + + align:start position:0% +from some of them we have +information on what ligands they bind + + align:start position:0% +information on what ligands they bind + + + align:start position:0% +information on what ligands they bind +but these are other criteria that are + + align:start position:0% +but these are other criteria that are + + + align:start position:0% +but these are other criteria that are +sometimes used in the field for + + align:start position:0% +sometimes used in the field for + + + align:start position:0% +sometimes used in the field for +target selection + + align:start position:0% +target selection + + + align:start position:0% +target selection +if they're homologous to previous + + align:start position:0% +if they're homologous to previous + + + align:start position:0% +if they're homologous to previous +interesting targets + + align:start position:0% +interesting targets + + + align:start position:0% +interesting targets +uh then that's uh + + align:start position:0% +uh then that's uh + + + align:start position:0% +uh then that's uh +that puts them on the high on the short + + align:start position:0% +that puts them on the high on the short + + + align:start position:0% +that puts them on the high on the short +list + + align:start position:0% +list + + + align:start position:0% +list +if they are conserved and we've talked + + align:start position:0% +if they are conserved and we've talked + + + align:start position:0% +if they are conserved and we've talked +about how important conservation is from + + align:start position:0% +about how important conservation is from + + + align:start position:0% +about how important conservation is from +time to time + + align:start position:0% +time to time + + + align:start position:0% +time to time +um then that might be + + align:start position:0% +um then that might be + + + align:start position:0% +um then that might be +a + + align:start position:0% +a + + + align:start position:0% +a +an approach if they're conserved + + align:start position:0% +an approach if they're conserved + + + align:start position:0% +an approach if they're conserved +and you knock it out + + align:start position:0% +and you knock it out + + + align:start position:0% +and you knock it out +then you might expect that to be lethal + + align:start position:0% +then you might expect that to be lethal + + + align:start position:0% +then you might expect that to be lethal +and that might make it a good target for + + align:start position:0% +and that might make it a good target for + + + align:start position:0% +and that might make it a good target for +a antibacterial + + align:start position:0% + + + + align:start position:0% + +if you want to limit the action of your + + align:start position:0% +if you want to limit the action of your + + + align:start position:0% +if you want to limit the action of your +therapy to the surface + + align:start position:0% +therapy to the surface + + + align:start position:0% +therapy to the surface +in order to say reduce + + align:start position:0% +in order to say reduce + + + align:start position:0% +in order to say reduce +the + + align:start position:0% +the + + + align:start position:0% +the +cross reaction + + align:start position:0% +cross reaction + + + align:start position:0% +cross reaction +with internal molecules + + align:start position:0% +with internal molecules + + + align:start position:0% +with internal molecules +you can sometimes + + align:start position:0% +you can sometimes + + + align:start position:0% +you can sometimes +restrict yourself to the surface + + align:start position:0% +restrict yourself to the surface + + + align:start position:0% +restrict yourself to the surface +acceptable proteins in fact a very large + + align:start position:0% +acceptable proteins in fact a very large + + + align:start position:0% +acceptable proteins in fact a very large +class of drugs is aimed at surface + + align:start position:0% +class of drugs is aimed at surface + + + align:start position:0% +class of drugs is aimed at surface +accessible + + align:start position:0% +accessible + + + align:start position:0% +accessible +membrane proteins + + align:start position:0% +membrane proteins + + + align:start position:0% +membrane proteins +and that and so very often those are + + align:start position:0% +and that and so very often those are + + + align:start position:0% +and that and so very often those are +prioritized high they're also the + + align:start position:0% +prioritized high they're also the + + + align:start position:0% +prioritized high they're also the +surface acceptable proteins are + + align:start position:0% +surface acceptable proteins are + + + align:start position:0% +surface acceptable proteins are +important if you're talking about + + align:start position:0% +important if you're talking about + + + align:start position:0% +important if you're talking about +vaccines + + align:start position:0% +vaccines + + + align:start position:0% +vaccines +which is an increasingly + + align:start position:0% +which is an increasingly + + + align:start position:0% +which is an increasingly +important + + align:start position:0% +important + + + align:start position:0% +important +or diagnostics that are non-invasive + + align:start position:0% +or diagnostics that are non-invasive + + + align:start position:0% +or diagnostics that are non-invasive +or at least not going to the interior of + + align:start position:0% +or at least not going to the interior of + + + align:start position:0% +or at least not going to the interior of +the cell + + align:start position:0% +the cell + + + align:start position:0% +the cell +and there are ways say with microarrays + + align:start position:0% +and there are ways say with microarrays + + + align:start position:0% +and there are ways say with microarrays +that you can ask which genes are + + align:start position:0% +that you can ask which genes are + + + align:start position:0% +that you can ask which genes are +differentially expressed in the disease + + align:start position:0% +differentially expressed in the disease + + + align:start position:0% +differentially expressed in the disease +state and that causes high + + align:start position:0% +state and that causes high + + + align:start position:0% +state and that causes high +prioritization + + align:start position:0% +prioritization + + + align:start position:0% +prioritization +now once you have that prioritization + + align:start position:0% +now once you have that prioritization + + + align:start position:0% +now once you have that prioritization +which comes from + + align:start position:0% +which comes from + + + align:start position:0% +which comes from +gene say genome sequencing and some of + + align:start position:0% +gene say genome sequencing and some of + + + align:start position:0% +gene say genome sequencing and some of +those other + + align:start position:0% +those other + + + align:start position:0% +those other +facts + + align:start position:0% +facts + + + align:start position:0% +facts +then we would like to have you've got + + align:start position:0% +then we would like to have you've got + + + align:start position:0% +then we would like to have you've got +your target you've got your genome + + align:start position:0% +your target you've got your genome + + + align:start position:0% +your target you've got your genome +sequence + + align:start position:0% + + + + align:start position:0% + +gene sequence for that target + + align:start position:0% +gene sequence for that target + + + align:start position:0% +gene sequence for that target +how then do you get the + + align:start position:0% +how then do you get the + + + align:start position:0% +how then do you get the +three-dimensional structure that helps + + align:start position:0% +three-dimensional structure that helps + + + align:start position:0% +three-dimensional structure that helps +helps you design + + align:start position:0% +helps you design + + + align:start position:0% +helps you design +drugs or improve the drugs that you have + + align:start position:0% +drugs or improve the drugs that you have + + + align:start position:0% +drugs or improve the drugs that you have +well one a + + align:start position:0% +well one a + + + align:start position:0% +well one a +very uh + + align:start position:0% +very uh + + + align:start position:0% +very uh +attractive + + align:start position:0% + + + + align:start position:0% + +approach given a protein sequence which + + align:start position:0% +approach given a protein sequence which + + + align:start position:0% +approach given a protein sequence which +might you might get from their dilutive + + align:start position:0% +might you might get from their dilutive + + + align:start position:0% +might you might get from their dilutive +genome sequences a practical approach + + align:start position:0% +genome sequences a practical approach + + + align:start position:0% +genome sequences a practical approach +might be + + align:start position:0% +might be + + + align:start position:0% +might be +to start with this genome sequence this + + align:start position:0% +to start with this genome sequence this + + + align:start position:0% +to start with this genome sequence this +gene sequence which is 99.99 accurate + + align:start position:0% +gene sequence which is 99.99 accurate + + + align:start position:0% +gene sequence which is 99.99 accurate +and try to predict + + align:start position:0% +and try to predict + + + align:start position:0% +and try to predict +the three-dimensional structure of the + + align:start position:0% +the three-dimensional structure of the + + + align:start position:0% +the three-dimensional structure of the +protein and its ligand specificity + + align:start position:0% +protein and its ligand specificity + + + align:start position:0% +protein and its ligand specificity +and if you walk through these these are + + align:start position:0% +and if you walk through these these are + + + align:start position:0% +and if you walk through these these are +kind of ballpark estimates some of them + + align:start position:0% +kind of ballpark estimates some of them + + + align:start position:0% +kind of ballpark estimates some of them +better than others to get from the + + align:start position:0% +better than others to get from the + + + align:start position:0% +better than others to get from the +sequence to exons we talked about this + + align:start position:0% +sequence to exons we talked about this + + + align:start position:0% +sequence to exons we talked about this +before might be an 80 percent + + align:start position:0% +before might be an 80 percent + + + align:start position:0% +before might be an 80 percent +remember these numbers really should be + + align:start position:0% +remember these numbers really should be + + + align:start position:0% +remember these numbers really should be +false positive false negatives + + align:start position:0% +false positive false negatives + + + align:start position:0% +false positive false negatives +so on but just fall apart 80 percent + + align:start position:0% +so on but just fall apart 80 percent + + + align:start position:0% +so on but just fall apart 80 percent +getting to exons exons to genes + + align:start position:0% +getting to exons exons to genes + + + align:start position:0% +getting to exons exons to genes +uh if you don't if you aren't privileged + + align:start position:0% +uh if you don't if you aren't privileged + + + align:start position:0% +uh if you don't if you aren't privileged +enough to have this the cdna + + align:start position:0% +enough to have this the cdna + + + align:start position:0% +enough to have this the cdna +then this is a uh + + align:start position:0% +then this is a uh + + + align:start position:0% +then this is a uh +error-prone process with maybe a 30 + + align:start position:0% +error-prone process with maybe a 30 + + + align:start position:0% +error-prone process with maybe a 30 +success rate + + align:start position:0% +success rate + + + align:start position:0% +success rate +once you have genes knowing its + + align:start position:0% +once you have genes knowing its + + + align:start position:0% +once you have genes knowing its +regulation whether it's on or off and + + align:start position:0% +regulation whether it's on or off and + + + align:start position:0% +regulation whether it's on or off and +the particular cell types you're + + align:start position:0% +the particular cell types you're + + + align:start position:0% +the particular cell types you're +interested in + + align:start position:0% +interested in + + + align:start position:0% +interested in +is is very difficult right now knowing + + align:start position:0% +is is very difficult right now knowing + + + align:start position:0% +is is very difficult right now knowing +the motifs + + align:start position:0% +the motifs + + + align:start position:0% +the motifs +is barely is barely a start on getting + + align:start position:0% +is barely is barely a start on getting + + + align:start position:0% +is barely is barely a start on getting +the full regulation so i would say 10 or + + align:start position:0% +the full regulation so i would say 10 or + + + align:start position:0% +the full regulation so i would say 10 or +less + + align:start position:0% +less + + + align:start position:0% +less +once you have a regulated gene getting + + align:start position:0% +once you have a regulated gene getting + + + align:start position:0% +once you have a regulated gene getting +the protein sequence is easy that's the + + align:start position:0% +the protein sequence is easy that's the + + + align:start position:0% +the protein sequence is easy that's the +genetic code getting this from the + + align:start position:0% +genetic code getting this from the + + + align:start position:0% +genetic code getting this from the +sequence the secondary structure + + align:start position:0% +sequence the secondary structure + + + align:start position:0% +sequence the secondary structure +is + + align:start position:0% +is + + + align:start position:0% +is +easy in the context some of these other + + align:start position:0% +easy in the context some of these other + + + align:start position:0% +easy in the context some of these other +things but still the accuracy is only + + align:start position:0% +things but still the accuracy is only + + + align:start position:0% +things but still the accuracy is only +around 77 percent i have nexus the + + align:start position:0% +around 77 percent i have nexus the + + + align:start position:0% +around 77 percent i have nexus the +references + + align:start position:0% +references + + + align:start position:0% +references +is cast which is something that is a + + align:start position:0% +is cast which is something that is a + + + align:start position:0% +is cast which is something that is a +competition for computational assessment + + align:start position:0% +competition for computational assessment + + + align:start position:0% +competition for computational assessment +of three-dimensional structure + + align:start position:0% +of three-dimensional structure + + + align:start position:0% +of three-dimensional structure +prediction for proteins that's been held + + align:start position:0% +prediction for proteins that's been held + + + align:start position:0% +prediction for proteins that's been held +uh since i think 94 and the next one is + + align:start position:0% +uh since i think 94 and the next one is + + + align:start position:0% +uh since i think 94 and the next one is +coming up in a couple of months + + align:start position:0% +coming up in a couple of months + + + align:start position:0% +coming up in a couple of months +and this is kind of a big + + align:start position:0% +and this is kind of a big + + + align:start position:0% +and this is kind of a big +race or bake-off between the different + + align:start position:0% +race or bake-off between the different + + + align:start position:0% +race or bake-off between the different +methods very exciting + + align:start position:0% +methods very exciting + + + align:start position:0% +methods very exciting +but unfortunately over decades it's + + align:start position:0% +but unfortunately over decades it's + + + align:start position:0% +but unfortunately over decades it's +still hovering around 77 for secondary + + align:start position:0% +still hovering around 77 for secondary + + + align:start position:0% +still hovering around 77 for secondary +structure and about 25 for ab initio + + align:start position:0% +structure and about 25 for ab initio + + + align:start position:0% +structure and about 25 for ab initio +three-dimensional structure + + align:start position:0% +three-dimensional structure + + + align:start position:0% +three-dimensional structure +then even if you have the + + align:start position:0% +then even if you have the + + + align:start position:0% +then even if you have the +three-dimensional structure at adequate + + align:start position:0% +three-dimensional structure at adequate + + + align:start position:0% +three-dimensional structure at adequate +accuracy getting the ligand specificity + + align:start position:0% +accuracy getting the ligand specificity + + + align:start position:0% +accuracy getting the ligand specificity +is problematic and it depends on the + + align:start position:0% +is problematic and it depends on the + + + align:start position:0% +is problematic and it depends on the +ligand + + align:start position:0% +ligand + + + align:start position:0% +ligand +if it's dna it's a good case if it's a + + align:start position:0% +if it's dna it's a good case if it's a + + + align:start position:0% +if it's dna it's a good case if it's a +small molecule it can be as low as 10 or + + align:start position:0% +small molecule it can be as low as 10 or + + + align:start position:0% +small molecule it can be as low as 10 or +worse + + align:start position:0% +worse + + + align:start position:0% +worse +now since each of these are fairly + + align:start position:0% +now since each of these are fairly + + + align:start position:0% +now since each of these are fairly +independent + + align:start position:0% +independent + + + align:start position:0% +independent +of + + align:start position:0% +of + + + align:start position:0% +of +estimates + + align:start position:0% +estimates + + + align:start position:0% +estimates +you can get a approximate overall + + align:start position:0% +you can get a approximate overall + + + align:start position:0% +you can get a approximate overall +accuracy which is a product of all those + + align:start position:0% +accuracy which is a product of all those + + + align:start position:0% +accuracy which is a product of all those +which is dismally small at the + + align:start position:0% +which is dismally small at the + + + align:start position:0% +which is dismally small at the +0.0005 + + align:start position:0% + + + + align:start position:0% + +and so + + align:start position:0% +and so + + + align:start position:0% +and so +it behooves one to use as many extra + + align:start position:0% +it behooves one to use as many extra + + + align:start position:0% +it behooves one to use as many extra +experimental data as one can or improve + + align:start position:0% +experimental data as one can or improve + + + align:start position:0% +experimental data as one can or improve +the algorithms that are weakest in this + + align:start position:0% +the algorithms that are weakest in this + + + align:start position:0% +the algorithms that are weakest in this +this journey from genome sequence to + + align:start position:0% +this journey from genome sequence to + + + align:start position:0% +this journey from genome sequence to +ligand specificity we'll pick up this + + align:start position:0% +ligand specificity we'll pick up this + + + align:start position:0% +ligand specificity we'll pick up this +thread + + align:start position:0% +thread + + + align:start position:0% +thread +right after a break and uh + + align:start position:0% +right after a break and uh + + + align:start position:0% +right after a break and uh +and carry on to actually how we get the + + align:start position:0% +and carry on to actually how we get the + + + align:start position:0% +and carry on to actually how we get the +three-dimensional structure + + align:start position:0% +three-dimensional structure + + + align:start position:0% +three-dimensional structure +whether it's predictive or experimental + + align:start position:0% +whether it's predictive or experimental + + + align:start position:0% +whether it's predictive or experimental +and the computational + + align:start position:0% +and the computational + + + align:start position:0% +and the computational +tasks there thank you + + align:start position:0% +tasks there thank you + + + align:start position:0% +tasks there thank you +take a break \ No newline at end of file diff --git a/3dU0v-EvUmA.txt b/3dU0v-EvUmA.txt new file mode 100644 index 0000000000000000000000000000000000000000..6c3ac491a7c0489509fe5a6163528ad721aa9fdd --- /dev/null +++ b/3dU0v-EvUmA.txt @@ -0,0 +1,3181 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation, or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: OK, OK, +settle down. + +It's time to start learning. + +One announcement. + +Tomorrow we'll have +the weekly quiz. + +In lieu of the Tuesday +celebration, we're going to + +move to Thursday, since the +holiday moved everything, + +compressed the week. + +So last day, we were talking +about doping of + +semiconductors, and I want +to finish up that unit. + +Just to refresh your memory, +we looked at how we could + +change the behavior of the +semiconductor by introducing + +impurity atoms. And when the +behavior of the semiconductor + +is dominated by the impurity +atoms, we term + +that behavior extrinsic. + +In other words, it's not the +behavior of silicon itself, + +but it's the behavior of silicon +as determined by the + +presence of some dopant atom. + +And we looked at the special +case of doping with a + +supervalent impurity. + +And here's the energy level +diagram for that situation, + +where we've got the valence +band down here, we've got + +conduction band up here, +separated by an energy gap. + +That's all characteristic of +plain vanilla silicon. + +But then when we dope with the +supervalent impurity, there is + +an extra electron. + +And that is put into a donor +level that lies just a tiny + +bit below the bottom of +the conduction band. + +And then, thanks to thermal +excitation, which gives us an + +average energy of about 1/40 of +an electron bolt, we get, + +for all intents and purposes, +100% excitation of the + +electronics that sit in the +donor level, excitation up + +into the conduction band. + +And this is what electrical +engineers term ionization. + +And I also reminded you last +day that this is the donor + +level, and for each donor atom, +there sits a donor level + +at the same value of energy, +but these are so far apart + +point, owing to the dilution, +the dilute concentration of + +the impurity, that we +don't violate the + +Pauli Exclusion Principle. + +So these are all sitting at the +same level and that's why + +they've given temperature +promotes all of them up into + +the conduction band, where +they are mobile. + +And then, just to complete the +review, we call this n-type + +because, thanks to doping, we +generate electrons in the + +conduction band, and electrons +are negative. + +Supervalent doping +gives us n-type. + +Then the total number of +electrons in the conduction + +band is the sum of those that +would have been generated by + +plain old thermal excitation. + +Thermal excitation operates +all the time. + +So with thermal excitation, +recall, we promote from the + +valence band up into the +conduction band. + +So we break one of these bonds, +shoot an electron up + +here, and leave a hole behind. + +So this generates the pair. + +Hole in the valence band, +and electron in + +the conduction band. + +That's always operative, but +owing to the energies + +involved, the band gap is on +the order of one electron + +volt, whereas the donor level +sits only about 1/50 of an + +electron volt below the +conduction band. + +So we get very, very little +promotion at room temperature. + +And in fact, it's something like +10 to the minus 19 is the + +fraction of promotion, and if +you say roughly 10 to the + +twenty-third per cubic +centimeter, that means you've + +got about 10 to the fourth +electrons per cubic centimeter + +due to this thermal excitation +from the valence band to the + +conduction band. + +Normally, when you dope a +semiconductor, you dope it + +around parts per +million level. + +And parts per million, that's +10 to the minus 6. + +If you take 10 to the minus 6 +times 10 to the 23, you get + +about 10 of the 17. + +Now you can see, 10 of the 17 +is vastly larger than 10 of + +the fourth. + +So for all intents and purposes, +once you've doped + +something, this contribution is +essentially 0, and so the + +electron population, the +conduction band, is that + +dictated by the impurity atoms, +which is why we say + +that this is exhibiting +extrinsic behavior. + +The intrinsic properties +are not + +visible, they're not palpable. + +They're immeasurable. + +So intrinsic is substantially +less than extrinsic. + +Now, the last thing I wanted +to do for you before we say + +goodbye to this fascinating +topic, which lays the + +groundwork for everything that +we know in the modern + +electronic era, parenthetically, +is to look at + +the other type of doping. + +I've showed you how to make +an n-type semiconductor. + +How do we make a p-type +semiconductor? + +So in that case, what +we can do is dope + +with a subvalent impurity. + +What do I mean by subvalent? + +Well, the valency of silicon +is 4, so I want + +something less than 4. + +So a good example is +boron into silicon. + +So boron is group 13, or 3, all +right, if you look on your + +periodic table. + +And silicon is group +14, according + +to the IUPAC notation. + +So let's go back and take a look +at how that might appear. + +So I'm going to draw the +silicon crystal. + +Remember, this is going into a +single crystal of silicon. + +So silicon is sp 3 hybridized, +and we have silicons + +everywhere in the structure. + +So we're going to +put silicons. + +And I'm trying to show +sp 3 hybridization. + +So this is 3 legs each in the +plane, then you've got 109 + +degrees here. + +So that's silicon, and so on. + +I get the three of them +just to complete + +enough of the picture. + +And now what we're going to +do, is introduced boron. + +And boron goes into the +silicon lattice + +and covalently bonds. + +It doesn't go sit in some void +space in between the silicons. + +It actually sits on +a silicon site and + +substitutes for the silicon. + +Now, boron is group 13. + +It's got 3 valence electrons. + +And so it forms bonds +with 3 silicons. + +And now there's a fourth silicon +here, and that silicon + +has an electron, but +the boron doesn't + +have a fourth electron. + +Here's where it gets +interesting. + +The driving force to complete +the picture here is so great + +that the system will actually +pull an electron out of a + +silicon-silicon bond-- + +and so I'm going to use a +different color chalk, and I'm + +going to indicate, just for +argument's sake, that we're + +going to pull an electron out of +this bond here, break this + +bond, and shoot that electron +over to here. + +That way, we get r months +around the boron. + +It says p3 hybridized. + +It just doesn't have that +extra electron. + +But now it rips the electron +out of this + +silicon-silicon bond. + +And what's the consequence +of breaking this bod? + +What's the electrical feature +that we've created here? + +A hole. + +So now we've created a hole +somewhere else in the crystal + +in order to satisfy the +desire of boron to + +get that fourth bond. + +And now can you see that for +every boron that I introduced + +into the crystal, I'm +going to make a hole + +somewhere in the crystal. + +And on the energy level +diagram, where + +do those holes live? + +Those holes live in +the valence band. + +So let's go make the energy +level diagram. + +So up here we have the +conduction band, and + +downstairs, we have the valence +band, as before. + +And I'm going to assume that we +got the thermal promotion. + +But it's so tiny in comparison +to the amount of boron we're + +going to put in. + +I'm not going to muddy the +water here and show that + +you've got pair formation. + +Because the extent of it is so +small, it doesn't make any + +difference. + +So now what happens? + +Now, I know I'm going to +generate holes here, and I've + +got to show this energy level. + +And this bonding level +is different from + +this bonding level. + +Agree? + +Silicon-silicon bond has +different bond energy from + +boron-silicon bond. + +So that means the top +of the valence band + +is different from-- + +because this valence band is +silicon-silicon-silicon. + +So it turns out that, and this +is not to scale, that the + +energy level of this bond is +just a little bit higher. + +And this is an energy level that +involves the accepting of + +electrons, whereas in +the other case, we + +were donating electrons. + +Hence, that's called +the donor level. + +This is called the +acceptor level. + +And it's about 1/50 of an +electron volt above the top of + +the valence band. + +And so what happens is that in +order to make this bond, we + +move something out of the +valence band up into the + +acceptor level and +generate a hole. + +And so for every boron that +we put in, we have + +another broken bond. + +And all of these lie at the same +level, but the dilution + +is so high, that they're so +far apart, that they don't + +violate the polyexplosion +principle. + +They're thermally promoted +up, and away we go. + +So now, under these +circumstances, the number of + +negative charge carriers no +longer equals the number of + +positive charge carriers. + +Because I've got all these +positive charge carriers. + +Thanks to the introduction of +boron, p is greater than n. + +So we've made a p-type +semiconductor, by the + +introduction of a subvalent +impurity. + +And we can redo the entire +central part of last day's + +lesson, which was +the Bohr model. + +Now, this is the sexiest +part of the Bohr + +model I've ever seen. + +This is really, really cool. + +The hole is mobile! + +The hole is mobile! + +And the boron is a little bit +shy of protons, right? + +It's 3 in a land of 4. + +So it's negative. + +So I've got a stationary +negative center, and I've got + +something positive revolving +around a negative center. + +This is an inverse Bohr model! + +Because the Bohr model has a +honking big positive center + +with a dinky little electron +revolving around. + +We've got the immobile negative +center, and the + +mobile hole revolving around. + +Go through, you get the +same set of quantum-- + +I mean, there's a whole bunch +of quantum levels in here. + +Fantastic! + +How far that Bohr model +can take us. + +So now you know how to make a +p-type semiconductor, you know + +how to make an n-type +semiconductor. + +And then what you can do +is put them together. + +And you can put, say, +boron-doped silicon opposite + +phosphorus-doped silicon. + +Be careful here. + +The fonts are really critical. + +This is uppercase P, +for phosphorus. + +This is lowercase p, for +positive doping. + +So don't go, oh, P, phosphorus, + +that means it's p-type. + +No, P gives you extra +electrons. + +It's n-type. + +So that's what uppercase P. + +This is a lowercase p. + +This is p-type. + +So now I've got p-type, +n-type, and so + +what do I have here? + +I've got a p-n junction. + +And this is the beginning +of solid state devices, + +rectification of A/C current, +diodes, you name it. + +And it all starts with +this, the chemistry. + +This is the birth of the +transistor, and all the modern + +electronics that we have +based on that. + +Later on, we'll show you how you +get the boron in, and how + +you get the phosphorus in. + +You don't just come in and +sprinkle it on top, and hope + +that it goes to the +lattice site. + +There's a lot of processing +involved. + +OK. + +So this is where I want to +hold for the unit on + +semiconductors, and how +it fits into the + +grand scheme of things. + +So in the books, you'll see-- + +this is a very crude drawing, +because this is showing n-type + +semiconductor with grossly +exaggerated numbers of donor + +electronics up here. + +There's no mention of +the donor level. + +So this is sort of + +semiconductivity, sort of pre-3091. + +This is extrinsic semiconduction +for idiots, I + +guess you'd call it. + +And then, same thing here. + +You see all of the holes +in the valence band. + +We know better, because we know +there's an acceptor level + +and there's a donor level. + +OK. + +So now we're going +to switch gears. + +Now here's the big transition, +right now. + +If the last two lectures didn't +leave high school + +behind, today we leave +high school behind. + +So those of you who have been +coasting up until now, thanks + +to your very good high +school background, + +start paying attention. + +Because it's high +school no more. + +So just to remind you +where we've come. + +We started over here, at the +beginning of the semester. + +And the big theme is going to +be, electronic structure + +informs bonding, which informs +state of aggregation. + +State of aggregation is +solid, liquid, or gas. + +So I want to show you how +we get to where we are. + +So we did all of these +topics, right? + +Bohr, or Sommerfeld quantum +numbers, multielectron. + +And then we came to +octet stability. + +And with octet stability, +we went a long way. + +We got into ionic bonding. + +We got into completing +the valence shell. + +And in fact, all of this +is a consequence + +of the octet stability. + +And that led us into +the various + +types of primary bonding. + +Ionic, covalent, metallic. + +And in some instances, +van der Waals. + +Solid argon is van +der Waals bond. + +It's the only kind of bonding, +so it's the primary bonding. + +But in some cases, like HCl, +how do you get liquid HCl? + +How do you get solid methane? + +So we had invoke secondary +bonding for some of these + +covalent molecules, and that +invoked dipole-dipole + +interaction, the London +dispersion force, which is the + +same as the van der Walls bond, +but I decided to mix + +things up, so that both men get +a little bit of attention, + +none of them feel slighted. + +And finally, hydrogen bonding, +in those special instances. + +And that allowed us to then +determine whether something + +was a gas, a liquid, +or a solid. + +And when it's a solid, +we're happy. + +Because this is 3091, +and we're interested + +in the solid state. + +By the way, what is a solid? + +Well, here's an operative +definition. + +That which is dimensionally +stable, has a + +volume of its own. + +It doesn't distort in +a gravity field. + +All right? + +Liquids will distort. + +Fluids, gases will distort. + +Now, there's two ways of +classifying solids. + +One is bonding type. + +That's what we did here. + +But the second way of +classifying solids is based on + +atomic arrangements. + +All right? + +So let's look at that. + +There's only two types of +atomic arrangement. + +Ordered and disordered. + +I love these taxonomies +that split everything + +into a choice of 2. + +That way, you just sort of go +through life and decide, is it + +left or is it right? + +Is it up or is it down? + +Is it ordered or is +it disordered? + +So what are the characteristics + +or an ordered solid? + +It has a regular atomic +arrangement. + +That means it's got a +long-range order. + +And I'll show you that in an +ordered solid, I know not only + +where my next nearest neighbor +is, where my tenth nearest + +neighbor is. + +I know where my hundred and +fifty second nearest neighbor + +is, because it's an +ordered solid. + +And we have a simple Anglo-Saxon +word for an + +ordered solid. + +It's called crystal. + +So when I say something is a +metallic crystal, I don't mean + +it's something that's got +magical properties, and if I + +put it over my head, I get +powerful or something. + +It just means I've got atoms +in an atomic regular + +arrangement. + +Now contrasting to that +is a disordered solid. + +And in that case, we have +a random arrangement. + +But I put an asterisk here +because, as they say in + +California, it's not +totally random. + +It's only random +up to a point. + +No long-range order. + +There may be short-range +order. + +In other words, I know what my +next nearest neighbor is, but + +I probably don't know where my +tenth nearest neighbor is + +Because the coordination shell +is established, but the next + +coordination shell, and the +next coordination shell, + +they're not established. + +And I'm going to show you, with +examples, what that means + +So we call those kinds of +disordered solids amorphous + +solids, as opposed to the +regular solids, which are + +crystalline solids. + +And there's a plain Anglo-Saxon +word for a + +disordered solid. + +It's glass. + +Now you might think, well, gee, +doesn't glass mean that + +it's transparent in +visible light? + +No, no. + +Maybe up until now, but I want +everybody who's ever taken + +3091 from me to be disabused of +the notion that glass means + +transparent. + +How do we think about the +question of transparency? + +And here I mean transparency +vis-a-vis visible light. + +I'm not going to say, what's +transparent to x-rays? + +That's pedantry. + +So how do we think about +whether something is + +transparent to visible light? + +We just ask ourselves, is the +band gap greater than 3 + +electron volts? + +The band gap is greater than 3 +electron volts, visible light + +zooms right through. + +It doesn't have enough energy +to excite the electrons, be + +absorbed, and re-emit. + +So that's what transparency +means. + +So I can have the kind of +material that's used in things + +like eyeglasses. + +It's transparent to visible +light because of + +its high band gap. + +Diamond, diamond is transparent +to visible light, + +and you wouldn't dare insult +diamond by saying + +that diamond is glass! + +In fact, watch the old gangster +movies from the + +1930s, that was the derogatory +term for fake diamonds. + +You call them glass. + +So how is it that diamond, which +is crystalline, it's + +transparent to visible light, +and yet the window glass that + +we have is transparent +to visible light? + +It has nothing to do with +state of order. + +Has everything to +do with this. + +In fact, David, if we could +shoot to the document camera, + +I'll show you a piece of glass +that's not transparent to + +visible light. + +How do we zoom in +on this thing? + +OK. + +Auto focus. + +So what I'm showing you is +a piece of obsidian. + +It's a naturally occurring +mineral. + +It's rich in silica, and it's +turned dark because it's got + +some iron impurity, and the iron +absorbs in the visible. + +And this is clearly not +transparent to visible light, + +and yet, it is a disordered +solid. + +This is a glassy solid. + +In fact, the white +speckles there + +are devitrified obsidian. + +It's actually started +to crystallize. + +So the crystalline form is the +part that's transparent. + +If you could peel off this +crystalline form, you'd + +actually end up with +something that's + +transparent to visible light. + +So here's an example of where +the crystalline form is + +transparent to visible light, +and the glassy form is opaque. + +So glass has nothing to +do with transparency. + +This is how you think about the +question of transparency. + +OK. + +So let's cut back to the +slides, David, please. + +So we're now going to start by +looking at ordered solids. + +So we're going to take next +several lessons and talk about + +ordered solids, and then after +that, we're going to take a + +few more lessons and talk +about distorted solids. + +Now first of all, what's +the term crystal? + +Where does it come from? + +It comes from the Greek word, +crystallus, which is the Greek + +word for ice. + +That's where we get +the term crystal. + +So we're going to start +with a history lesson. + +That's how we start everything +in 3091. + +A history lesson. + +So we go way, way back to +Isaac Newton's time. + +The Reformation, Charles, Oliver +Cromwell, all those + +exciting times. + +In merry old England, there +was Robert Hook. + +You know him from Hook's +Law, in mechanics. + +So he was doing military +research in 1660. + +He was trying to understand what +was the optimal way to + +stack cannon balls. + +So when you're on a battle +front, you want to figure out + +how to keep your material +compactly arranged. + +You don't lie them +on the ground. + +So from that, he concluded that +crystal that is a regular + +array must owe its shape +to the packing + +of spherical particles. + +So that's what he was thinking, + +or trying to imagine. + +Remember, Democritus said that +we have these indivisible + +particles, but no one had +ever seen them before. + +Then in 1669, a Dane by the +name of Steenson who was + +working in Italy was looking +at quartz crystals. + +And he was studying various +quartz crystals. + +By that I mean, quartz crystals +of different sizes. + +And what he observed was, didn't +matter what the size of + +the crystal was. + +They always had the same +angles between + +corresponding faces. + +So if I give you a big crystal +and a smaller crystal of the + +same material, and a smaller +crystal, and they all have the + +same shape, Can you imagine that +you might conclude that + +that is reflective of something +down at the atomic + +level, and if you could get down +to the atomic level, that + +spacial arrangement would +hold right now? + +Because that's how +it grew, right? + +It started from a small number +of atoms and grew, grew, grew. + +Why would it start with one +shape, and all of a sudden + +change to another shape? + +It doesn't make any sense. + +At least, not to me. + +And certainly not to Steenson. + +And then we go to +Holland, 1690. + +Christiaan Huygens. + +And he was studying +calcite crystals. + +And he drew drawings of atomic +packing and bulk shape. + +This is 1960. + +I'm going ot show you an +image from his book. + +This was drawn in 1690. + +See, this is stacking of +cannonballs, but he was + +looking at a calcite crystal. + +Actually, Dave, could we cut +back to the document camera? + +We're going to do a +fair bit of this. + +I'll show you calcite crystal. + +This is what he had +to work with. + +It looks like this. + +To give you a sense of scale-- + +what do I have? + +Do I have anything +you'd recognize? + +OK, here's a soda can to give +you a sense of scale, OK? + +This is one honking big +calcite crystal. + +I got it as a gift from someone +who watched 3091 + +lectures on OpenCourseWare. + +And he said, if I ever +come to town, can + +I attend your lecture? + +I said, sure. + +And he showed up, he attended +the lecture. + +He was a man probably in his +early 40s, and as a pastime he + +collects gemstones. + +And he gave me this giant +calcite crystal, because the + +one I was using before +was so pathetic. + +He said, I've got +to give you one. + +And then, I thought, jeez, +if I could ever come upon + +somebody who's in the +gold business-- + +and you know, he might give me +a big honking crystal of + +face-centered cubic metal +called gold-- + +which broke $1,000 an ounce +yesterday, but-- + +anyways, if you're out there, +and you're watching these + +lectures, I'm here. + +It's 8201, and you can +see any anytime. + +My assistant's name is Hillary, +she'll take the call. + +All right. + +So let's go back +to the slides. + +Dave, could we cut to +the slides, please? + +Thanks. + +All right. + +So now-- + +oh, I'm going to show +you a few others. + +Remember, here's the idea, that +we're looking down to the + +elemental level. + +So if you look on your periodic +table, it says 10, + +you see, 10, it's supposed +to be tetragonal. + +So here's a crystal of 10. + +Dave, cut back, please. + +We're going to go back and +forth today a lot. + +There's a piece of ten 10. + +So you might look at it +and say, gee, that + +looks kind of cubic. + +But if you look carefully, the +vertical dimension is greater + +than the horizontal. + +In fact, it's got +a square base. + +And then, this is +the tall one. + +Which, if we cut back to +the slides, let's see. + +And that's what tetragonal +looks like. + +And we'll study all of these +in a few minutes. + +These are some giant crystals +I didn't dare drag in. + +This is sort of human-sized +scale. + +This is balsalt, which is a +magnesium iron silicate. + +It's on a coast of Iceland. + +Dave, let's show them +a few more. + +Here's one more, if we go +to the document camera. + +This was beryllium aluminum +silicate. + +This is a barrel. + +And you can see, this has +got a hexagonal habit. + +So something's going on at the +atomic level that's different + +as we go from one crystal +structure to the other. + +What else have I got here? + +Here's some calcite, here's +some fluorite. + +Look at this one. + +This is square pyramidal +but it's ionic. + +So don't give me any of +that sp3 d2 stuff. + +Because it's not going +to work here. + +All right. + +Let's go back to the +slides, please. + +So then we jump to +1781, to France. + +Rene Juste-Hauy was at the +Sorbonne, and he was studying + +the cleavage of calcite +crystals. + +In other words, he was +taking these things + +and breaking them. + +So he'd go to work every +day and break things. + +And he studied the shards, and +he found that the shards were + +all rhombahedral. + +the same shape as the +parent crystal. + +No matter how small the +shards got, they + +always looked like this. + +He didn't end up with +cubic shards. + +He didn't end up with +long slivers. + +He always ended up with +rhombahedral slices. + +So the other thing is that he +didn't end up with any voids. + +No matter how he cut this thing, +he never got voids. + +So he reasoned that this must be +the way things are packing + +in three space perfectly. + +So then he said, gee. + +If they pack perfectly +rhombahedrally-- + +we all know that we can stack +boxes together perfectly, + +cubes together. + +So he, being a Frenchman, said, +what's the mathematical + +formulation? + +They were steeped in +mathematics there. + +That wasn't a slur against +the French. + +It's a compliment. + +He said, what are the +mathematically distinct + +shapes, that if we stack them +together in three space they + +will fill three space +with no void? + +And the answer is seven. + +Seven space-filling +volume elements. + +By the way, the gabled milk +carton isn't one of them. + +And so he called the crystal +system, so I call seven + +distinct shades of +milk cartons. + +And these are the seven crystal +systems, and they're + +described geometrically, and +you'll get a chance to go + +through them. + +The cube is one of them. + +Tetragonal. + +Here's the calcite, +rhombahedral. + +There's barrel, hexagonal, +and so on. + +The seven different ways you +can feel three space. + +And this is from the archival +readings of my predecessor, + +Professor Witt. + +Actually, just to give your +a sense, here's the + +two-dimensional analogy. + +If I said to you, we're going +to open a company, and we're + +going to make bathroom tile, and +we want to make it sort of + +an upscale company, you know, +not everybody wants boring old + +square tiles. + +But definitely, I can cover two +space with square tiles by + +putting them side by side, +one on top of the other. + +What's another way I can fill? + +I can go with rectangular +tiles. + +So this dimension is different +from that dimension. + +What's another way? + +I can use a rhombus, right, +at 60 degrees. + +Or I can use just a plain old +parallelepipede at some + +arbitrary angle. + +And if you go over to the Stata +Center, to the Gehry + +building, take a look at +the shape that they + +chose as the unit cell. + +This is the repeat group, if +you like, or the unit cell, + +because that's the one that's +going to be cookie cutter + +replicated, side by side. + +When you're putting the skin +on a building, you have to + +make everything fit with +no holidays, right? + +Because you don't want gaps. + +what they chose was +this area element. + +And all the pieces of stainless +steel are cut to + +this shape. + +And that's how you +make things fit. + +How you take something and make +it fit around a three + +dimensional object is tricky. + +It's the same thing as the +clothing problem, right? + +How do you take a flat piece of +cloth and make it fit the + +contour of the human body? + +At least, you know, in men's +clothes, you know, we've got + +dimensions. + +We've got sleeve length, got +waist, chest. We've got all + +these numbers. + +For a woman, 8. + +One number? + +One number? + +Fashion designers don't +know crystallograpy! + +If they knew crystallography, +they'd know how + +to specify the shapes! + +If you understand this, you can +start your own business + +and make clothes that fit. + +And I guarantee you, there's +a market out there for + +clothes that fit. + +What about this one? + +Pentagon. + +We're going to make pentagonal +bathroom tile. + +Well, when we install these, +we're going to have to use two + +different colors. + +You can see this +up here, right? + +This is pentagonal +bathroom tile. + +It doesn't fit. + +You've got all these +white spots. + +So this is not a unit cell. + +This is not one of the crystal +systems for two dimensional. + +So this one's no good. + +We better put an x through it, +in case someone fell asleep, + +and wake up, and then tell +me that that's OK. + +All right. + +So then we move about half +a century forward, to the + +turbulent year 1848, +also in France. + +Auguste Bravais. + +And what Bravais did, is +he said, all right. + +This is just filling space. + +But where are the atoms? + +I haven't told you where +the atoms are, right? + +You know, as far as you're +concerned, maybe there's one + +atom in each of these boxes. + +Or maybe there's atoms at +the corners of the box. + +Or maybe there's atoms +at the corner and the + +center of the box. + +Where are the atoms? + +I've simply told you that I +can fill three space with + +boxes, or with these rectangular +boxes, and so on. + +So he set out mathematically +to prove how many different + +arrangements of points +there are in space. + +It's sort of like saying, if I +want to tell you where all the + +apples are in the orchard, I'm +going to tell you where the + +trees are, and I'm going +to tell you where the + +apples are on a tree. + +So where do the atoms go +inside these boxes? + +Turns out there's 14 different +arrangements. + +And what do I mean by that? + +This is a good example. + +So we've already established +that the cube is a + +space-filling volume element. + +It's one of the seven. + +But look. + +If I'm one of the atoms at the +corners here, I've got six + +nearest neighbors. + +This is also a cube, but it's +got atoms at the corners and + +an atom in the center. + +You might say, well, what's +the big deal? + +If you're in the atom in the +center, and you look to the + +nearest neighbors, you've got +eight nearest neighbors. + +Here you only have six +nearest neighbors. + +So this is spatially +differentiated from this. + +So what why don't +we keep going? + +And by the way, the same +environment of that central + +atom that's coded green is the +same environment of any of the + +atoms on the corners. + +They're all symmetric. + +So both are cubes, but they +have different space point + +environments. + +And here's a third one, where +we put atoms at the corners + +and atoms on each +of the faces. + +So this atom on the face, you +can see, it's got one, two, + +three, four atoms in +the plane, three + +behind, three in front. + +It's got 12 nearest neighbors. + +This has got eight nearest +neighbors, this has got six + +nearest neighbors. + +So Bravais went through and he +said, let's take those seven + +crystal systems. Let's put atoms +in distinguishable ways. + +How many distinguishable ways +can we come up with atom + +arrangements? + +And the answer is 14. + +Now, what we're going to do in +3091, is we're just going to + +confine our conversation +to the cubics. + +Because you use orthogonal +vectors, they're all the same + +length, the mathematics +are simple, and the + +principles are the same. + +And by the way, boatloads +of materials are + +in the cubic system. + +So it's not as though we just +chose something that's + +convenient but irrelevant. + +So here are the different +Bravais lattices. + +So you can see the cubic, +there's simple cubic, + +body-centered cubic, +face-centered cubic. + +With tetragonal, there +is simple tetragonal, + +body-centered tetragonal. + +There's no face-center +tetragonal. + +If you try to make face-center +tetragonal it's degenerate, + +reverts to one of the +other systems. + +So these are the distinguishable +systems. And + +everything, including +crystalline proteins-- + +if the protein crystallizes, it +forms atomic arrangements + +in one of these Bravais +lattices. + +Everything conforms to one of +these Bravais lattices. + +And if it doesn't, it means it +lacks long-range order, in + +which case it is a glass. + +That's it. + +So here's face-centered cubic. + +You can see the placement. + +But there's something that's +been simplified here. + +Right now what you see is a +single atom, designated by a + +hard sphere. + +But at each of these lattice +points, I can put + +more than one atom. + +So let me show you what +I mean by that. + +What I want to do, is put +different numbers of atom + +arrangements at the +lattice point. + +So those positions, the +distinguishable positions, are + +called lattice points. + +And now I want to define +the crystal structure-- + +the crystal structure is the +complete accounting of atomic + +arrangement. + +It's the complete description +of atomic arrangement. + +And we don't have to go too far, +because we just have to + +get the base unit, the unit +cell, and then just + +repeat the unit cell. + +Complete description of +atomic arrangement. + +And so how we going +to go about this? + +We're going to start with +a Bravais lattice. + +And what is the Bravais +lattice? + +The Bravais lattice is simply +a point environment. + +And this will mean something to +you in about three minutes, + +when I give you the rest +of the description. + +So it's a set of points in +space and the basis. + +And what is the basis? + +The basis is the atom group +at each lattice point. + +So what do we mean by that? + +Well, let's look at what's +up on the board. + +What's up on the board is +face-centered cubic. + +So let's do all of these. + +So we're going to say that the +Bravais lattice, in this case, + +in face-centered cubic, FCC. + +That's what this one is, +up on the board. + +And we've got dots indicate +the points. + +Because really, the points +are nothing. + +It's a concept. + +See, it's French. + +It's a concept, right? + +What's this? + +See what I'm holding? + +I'm holding a Bravais lattice. + +It's just a set of points. + +It's like a John Cage piece, +you know, a bunch of rests. + +So if I go to the piano +and I play rests in + +five four time, listen. + +Isn't that great? + +Man, it's fantastic. + +All the different rests, +and different-- + +So this is a set of +lattice points. + +Now I'm going to put +something on them. + +You think I'm kidding. + +I'm not. + +All right. + +Now what's the basis? + +If I put a single atom, we have +what's up on the slide. + +And so that's the representation +of metal. + +So for example, gold is FCC, +with a single gold atom at + +each lattice point. + +Aluminum, copper, platinum. + +These are all FCC metals. + +So there's a single atom at +Bravais lattice point, and so + +the crystal structure +is known as FCC. + +It's the same as the +Bravais lattice. + +It's called FCC. + +OK. + +Now, we can also put a molecule +at each lattice site. + +So I'm going to put +up the FCC here. + +Here's the FCC. + +There's the cube, the set of +lattice points, and the + +lattice points are-- + +I'm going to just illustrate +on the front face. + +One, two, three, four, and a +fifth atom at the front face. + +Now these are the points. + +I could either put simple atoms +there, and the central + +image there shows what happens +when you have the close-packed + +arrangement, the atoms are +so big that they touch. + +Or what I could do, at +each lattice point, + +I could put a molecule. + +So for example, I could +put methane. + +I could put CH4. + +A methane molecule. + +Because when one of you gets +to Jupiter, and you see the + +methane ice, and you go, oh. + +That's FCC. + +Because everybody else on the +mission hasn't taken 3091. + +They don't have a clue what +they're looking at. + +But you go, that's face-centered +cubic. + +And they go, huh? + +And this is at each +lattice site. + +You see, my point is, now look, +here's the difference. + +All five of these, the carbon +and the four hydrogens, sit at + +this lattice site. + +All five atoms sit at +this lattice site. + +It's not that the carbon goes +here, one hydrogen goes over + +at one lattice site, one +hydrogen over here. + +You don't have the methane +straddling the unit cell. + +You have all five atoms +here, five atoms here. + +At every lattice point, I +have all five atoms at + +each lattice point. + +So in that case, we also +have, it's FCC. + +So methane ice is face-centered +cubic. + +Because it's spherical. + +They pack just like gold +atoms. You know, from a + +distance, we can model this +as a sphere, as a point. + +Or we could put an ion pair. + +An example of that is sodium +and chloride, and this is + +called rock salt crystal +structure. + +Rock salt. + +Let's look at that one. + +So at each last lattice point, +I'm going to put two ions. + +Not one, two. + +This is taken from your text. + +So you might look at this and +say, well, here's the front. + +You might look at this and say, +well, isn't this kind of + +like simple cubic? + +Because I've got one, two, +three, four, but I've got + +different atoms if I +try it that way. + +See, this is taken from +a different book. + +I did some highlighting on it. + +So this is sodium +chloride again. + +One, two, three, four, five. + +With this lattice site, I put +the chloride atom and the + +sodium atom. + +The pair of atoms are +associated with + +this lattice site. + +You might say, yeah, but +this is way over here. + +Doesn't matter. + +I'm going to anchor all of those +to this lattice site. + +To this lattice site, I'm going +to anchor this and the + +sodium ion. + +So this is not simple cubic. + +Because if I try to call this +simple cubic, I have different + +atoms at different lattice +sites, and that's a no-no. + +Has to be the same. + +So if I associate the pair, +chloride ion and sodium ion, + +chloride ion and sodium ion, +chloride ion and a sodium ion + +not depicted. + +It's off the diagram here. + +And I put these dots at the +center of each chloride ion. + +Can you see that I'm +at the face of FCC? + +So that's an FCC Bravais +lattice, but it's got two + +atoms, in this case, both ions, +associated with each + +lattice point. + +I will come to the +dogs in a second. + +And now there's a last +one I can do. + +And that's got two atoms, +but not an ion pair. + +We're going to put +an atom pair. + +Got an atom pair, and that +looks like this. + +I'm going to put a carbon atom, +one carbon atom, and a + +second carbon atom. + +And this angle here +is 109 degrees. + +And I'm going to put this pair +of carbon atoms together, and + +when I do that, and I replicate +that through FCC, I + +end up with diamond cubic. + +And I'll show you a +three-dimensional example of + +that next day. + +So just bear in mind that if you +have an ion pair, you end + +up with rock salt. + +If I show you this pair, +this is due to the sp3 + +hybridization. + +And so examples of this one +are diamond, not graphite, + +just diamond, silicon-- + +so everything that I've shown +you about single crystals, and + +intrinsic and extrinsic +semiconduction, is diamond + +cubic crystal structure. + +But it's not one of the +Bravais lattices. + +It's an FCC Bravais +lattice with two + +atoms per lattice site. + +That's diamond cubic +crystal structure. + +But it extends to +two dimensions. + +So here's an Escher print. + +It's got all these dogs. + +In two dimensions, what's the +crystal structure here? + +Well, there's no such thing +as body-centered cubic. + +There's no third dimension +in two dimensions. + +So you've only got simple cubic +or face-centered cubic. + +So what do we have here? + +Well, you see, you've +got a problem. + +Because the black dogs are +facing the opposite direction + +of the white dogs. + +So you can't go one, two, +three, four, and make + +anything that way. + +So instead, I put dots on the, +I don't know what you call + +this part of the dog. + +I don't know. + +This part of the dog. + +The leg? + +Whatever you call this thing. + +Yeah. + +You put it on the same +spot of the dog-- + +maybe I should have used his +eye, I know how to call it. + +Anyway. + +So I put these things +up, right? + +And that means that if I +associate the four dogs with + +this point, the two dogs facing +the right, and these + +two dogs facing the left. + +So these four dogs are +associated with + +this lattice site. + +Then I move up here, and I've +got the same thing. + +One, two, three four. + +Two dogs facing right, +two dogs facing left. + +So that means I've got a simple +cubic bravais lattice, + +and the basis is four dogs. + +Four dogs as my basis. + +And with that combination of a +simple cubic lattice and four + +dogs is the basis, I can make +the entire structure. + +That's what this is all about. + +That's my unit cell, that's +my repeat unit. + +So there's simple cubic, +right there. + +So instead of a single atom at +each corner, or these are + +spheres that are touching, +we got the four dogs. + +Here's another one. + +Once I got the Escher, I kept +flipping through the book. + +I don't know what this thing +is, but it's creepy. + +Anyway. + +It's wallpaper. + +If it's wallpaper, +it's ordered. + +If it's ordered, it's a +two-dimensional crystal. + +If it's a two-dimensional +crystal, it has to conform to + +one of the 14 Bravais +lattices. + +So which one is it? + +So I looked at this for a while, +and I took this happy + +entity here, and I put +a dot in its belly. + +So wherever I found one +of these, I put a dot. + +and then I connected the dots, +and what do I get? + +I got the rhombus. + +Now, what's the basis? + +That's the Bravais lattice. + +What is the basis? + +So I went over here and I said, +well, if I start from + +this thing and I go all +the way up, I got some + +tail, blue tail here. + +And this thing way down +here looks like + +it's missing a tail. + +So if I start from this, go all +the way down to here, and + +capture all of this material +in between and associate it + +with that lattice point, +that can be my basis. + +And then I take that set of +imagery, and I put it on top + +of this, where it's centered at +about this thing's navel, + +and put it around here. + +You can see, the translation +is obvious there, and the + +translation is obvious here. + +There's the wallpaper. + +So it's part of a Bravais +lattice, only in two + +dimensions, you see? + +This is crystallography. + +That's all it is. + +Crystallography. + +All right. + +So the next thing that we have +to do, it's kind of a little + +bit boring, but you need to know +this stuff, because it's + +formative for the next unit. + +It's the characteristics +of cubic lattices. + +Now what do I mean, the +characteristics? + +I mean the geometric +characteristics. + +So there's a table here that +I've taken out of your + +archival reading. + +If you go to the website, +there's a set of notes that + +were written by my predecessor, +Professor Witt. + +And if you go and look +this up, this unit on + +crystallography, there's +this table. + +And it shows such things as +the unit cell volume. + +Well, what's the unit cell? + +The unit cell is this cookie +cutter cube that's the repeat + +unit, and it has a dimension +here called a, which is the + +lattice constant. + +It's the size of the box. + +So what's the volume +of the unit cell + +Well, duh, it's a cubed. + +That's obvious, all right? + +Doesn't matter whether it's +simple cubic, face-centered + +cubic, body centered cubic. + +How many lattice points +per unit cell? + +Well, that's-- how many atoms +do I get per unit cell? + +If you look at this, you +say, well gee, it's-- + +you know, if you've got the +simple cubic, you've got them + +at the eight corners, so +it's eight, right? + +Well, no, because each atom on +the corner is inside this + +cell, but it's also inside the +neighboring cell, and it's + +inside each of the eight +neighboring cells. + +So I have eight times +one eighth. + +So the total amount of atom +within the cube is only one. + +That's why you've got to go +through this derivation. + +So here's an example for +face-centered cubic. + +You see the corners, one, +two, three, four? + +There's eight of those. + +Eight times one eighth is one. + +And then you've got these atoms +on the face, and there's + +one, two, three, four, +five, six, right? + +Six faces. + +But each of these atoms +on the face is only + +half inside the cube. + +The other half is in +the other cube. + +So I got six times one half is +three, and that gives me four. + +So that's how you go through, +and figure out + +what's going on. + +And then you can look at things +like nearest neighbor + +distance, and what's the +relationship between the + +radius, if you're looking +at hard sphere packing. + +So here's a good example. + +Here's the hard sphere +packing model. + +So I've got atoms all +the same size, and + +they're packed to touch. + +And they're packed to touch so +that in the end, I end up with + +a face centered cubic +arrangement. + +And so what's the relationship +between the radius and the + +lattice constant? + +And it's just simple +trigonometry, right? + +4r equals 2a squared, and you go +through it, and that's how + +you end up with all +these formulas. + +So that's what going on. + +All right. + +So I think we're going to move +to the last five minutes here. + +So just a couple of comments. + +Today we played music +when you came in. + +It was Burning Down the House. + +An old piece by Talking Heads. + +Why was I playing Burning +Down the House? + +Well, I want you to study +this painting. + +This is a painting by Georges +Braques, from 1908, And it's + +called The Houses at L'estac, +or if I speak Canadian, The + +Houses at L'estac. + +And you see the thing +about these houses? + +You see the ones in the +background have better + +definitions than the ones +in the foreground? + +And the ones in the foreground +are all distorted, and kind of + +falling over? + +Well, when this was exhibited +at the Salon, on the critics + +lambasted it. + +They said, this thing is +absolutely childish. + +And one of the critics +said, this isn't + +a painting of houses. + +This is nothing but +a stack of cubes. + +And from this painting, and that +negative comment, came + +the term cubism. + +And so the entire movement of +cubism comes from this. + +And since we're studying the +properties of cubic crystals, + +I thought the connection +was pretty tight. + +And that's why I chose +that piece. + +Don't go anywhere yet. + +We still have a couple +of minutes. + +It's not better out there +than it is in + +here, I guarantee you. + +All right. + +So now I want to show you +one of the properties. + +Why do we care about atomic +arrangement Suppose some of + +you are interested +in fiberoptics. + +One of the things you have to +do in fiberoptics is make + +junctures, because you can't run +a cable 100 miles without + +making some junctures. + +Well, atomic arrangement +reflects microscopic + +properties. + +And one of the properties that +you can have in a crystal is + +something called birefringence, +depending on + +the atomic arrangement. + +So what happens is if you have +a ray that comes in from the + +left here, it splits into two. + +And that's no good, in +certain instances. + +In other instances, if you want +a beam splitter, you want + +something birefringent. + +So look at all these crystals. + +Quartz is birefringent. + +Ice is. + +You've seen it. + +Calcite is birefringent. + +What do I mean by that? + +Well, Dave, can we cut to +the document camera? + +Right. + +So here's a here's +a crystal of-- + +well, this is my handwriting. + +It's beautiful. + +Let's write-- here's more. + +Isn't that beautiful? + +OK, enough about me. + +Now let's-- + +All right. + +So this is birefringent. + +But what happens if +we rotate it? + +We can change the degree. + +And if we're really clever, and +we get it onto the optical + +axis, we can actually get these +things to superimpose. + +Here's a piece of cryolite. + +This is the stuff they +make aluminum out of. + +They dissolve aluminum in it. + +And you can see that, see, I +loaned it to somebody, and + +they dropped it. + +And when they dropped +it, they damaged it. + +That's what happens. + +Look, it's all crunched +up there. + +But anyway, I don't want +to get into that. + +But so you can see, if we turn +this and we get it right on + +the optical axis, we can +actually make these things + +line up sometimes. + +Anyway. + +So you can see the property +of birefringence. + +OK. + +Let's go back to documents, +Dave. One more thing. + +Last thing I want to show you. + +You know gold. + +Gold looks like this. + +It's yellow, right? + +Well, depending on how you, you +know, those of you have + +seen certain wedding bands know +that if you want to make + +a white gold, you add +nickel to it. + +And once the nickel content gets +above a certain level, + +the gold looks white. + +In other words, just metallic +reflective. + +In Eastern Europe, it was common +to add high levels of + +copper, in which case, you get a +beautiful rose-colored gold, + +or pink gold. + +I'm going to show you +some blue gold. + +This isn't a joke. + +This is 14 karat. + +It's 40 plus percent +by weight gold, and + +the balance is indium. + +And when you add indium +to gold, you get blue. + +Document camera, please. + +Just so that you remember. + +OK. + +That's gold. + +This is gold foil. + +Rutherford, et cetera, +et cetera. + +You know, this is yellow gold. + +Ho-hum. + +This is white gold. + +Same deal, but with +some nickel. + +Now it's reflecting off +of the yellow gold. + +Boy, there's a lot of +yellow in here. + +Where's that coming from? + +It's hard to tell. + +All right. + +Now Let's look at +some blue gold. + +This is blue. + +So, but it's brittle. + +So you know, what are you going +to do with something + +that's brittle? + +You can't shape it. + +So I have an idea. + +So here's my idea. + +See, what we do is-- + +see this? + +We do, instead of this, +we put this. + +We drill a hole in it, we put +hands on it, we sell it for a + +lot of money. + +It's blue gold. + +It's blue karat gold. + +What you can do if you +understand crystallography. + +All right, get out of here. + +I'll see you on Friday. \ No newline at end of file diff --git a/5NUS6bcUXmY.txt b/5NUS6bcUXmY.txt new file mode 100644 index 0000000000000000000000000000000000000000..60804556ef82d21c7dd7ab9cbd2513cef609a123 --- /dev/null +++ b/5NUS6bcUXmY.txt @@ -0,0 +1,9930 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT open courseware + + align:start position:0% +of MIT courses visit MIT open courseware + + + align:start position:0% +of MIT courses visit MIT open courseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so I wanted to talk a little + + align:start position:0% +ocw.mit.edu so I wanted to talk a little + + + align:start position:0% +ocw.mit.edu so I wanted to talk a little +bit about cork um partly because cork is + + align:start position:0% +bit about cork um partly because cork is + + + align:start position:0% +bit about cork um partly because cork is +kind of interesting + + align:start position:0% +kind of interesting + + + align:start position:0% +kind of interesting +and cork has a structure that's a little + + align:start position:0% +and cork has a structure that's a little + + + align:start position:0% +and cork has a structure that's a little +bit like one of those honeycomb things + + align:start position:0% +bit like one of those honeycomb things + + + align:start position:0% +bit like one of those honeycomb things +so what I'm going to do is I'm just + + align:start position:0% +so what I'm going to do is I'm just + + + align:start position:0% +so what I'm going to do is I'm just +going to um talk and go through the + + align:start position:0% +going to um talk and go through the + + + align:start position:0% +going to um talk and go through the +slides I'm not going to write the notes + + align:start position:0% +slides I'm not going to write the notes + + + align:start position:0% +slides I'm not going to write the notes +on the board um there there's only a few + + align:start position:0% +on the board um there there's only a few + + + align:start position:0% +on the board um there there's only a few +pages of notes and it's in the Stellar + + align:start position:0% +pages of notes and it's in the Stellar + + + align:start position:0% +pages of notes and it's in the Stellar +site so I'm not going to write notes for + + align:start position:0% +site so I'm not going to write notes for + + + align:start position:0% +site so I'm not going to write notes for +this because it's just really for fun so + + align:start position:0% +this because it's just really for fun so + + + align:start position:0% +this because it's just really for fun so +this first slide starts off with sort of + + align:start position:0% +this first slide starts off with sort of + + + align:start position:0% +this first slide starts off with sort of +historical uses of cork cork was used by + + align:start position:0% +historical uses of cork cork was used by + + + align:start position:0% +historical uses of cork cork was used by +the Romans and they used it for the + + align:start position:0% +the Romans and they used it for the + + + align:start position:0% +the Romans and they used it for the +souls of sandals the same as we do and + + align:start position:0% +souls of sandals the same as we do and + + + align:start position:0% +souls of sandals the same as we do and +they used it for stopping bottles of + + align:start position:0% +they used it for stopping bottles of + + + align:start position:0% +they used it for stopping bottles of +wine the same as we do but they didn't + + align:start position:0% +wine the same as we do but they didn't + + + align:start position:0% +wine the same as we do but they didn't +realize that you could just use the Cork + + align:start position:0% +realize that you could just use the Cork + + + align:start position:0% +realize that you could just use the Cork +and they would take the cork put it in + + align:start position:0% +and they would take the cork put it in + + + align:start position:0% +and they would take the cork put it in +the wine bottle and then they would sort + + align:start position:0% +the wine bottle and then they would sort + + + align:start position:0% +the wine bottle and then they would sort +of use pitch which is you know kind of + + align:start position:0% +of use pitch which is you know kind of + + + align:start position:0% +of use pitch which is you know kind of +like a tar stuff from a tree um and they + + align:start position:0% +like a tar stuff from a tree um and they + + + align:start position:0% +like a tar stuff from a tree um and they +would use the pitch and and sort of seal + + align:start position:0% +would use the pitch and and sort of seal + + + align:start position:0% +would use the pitch and and sort of seal +the bottle with with the pitch and in + + align:start position:0% +the bottle with with the pitch and in + + + align:start position:0% +the bottle with with the pitch and in +the 1600s there were some Benedictine + + align:start position:0% +the 1600s there were some Benedictine + + + align:start position:0% +the 1600s there were some Benedictine +monks that realized that you could just + + align:start position:0% +monks that realized that you could just + + + align:start position:0% +monks that realized that you could just +use the Cork and not use the pitch and + + align:start position:0% +use the Cork and not use the pitch and + + + align:start position:0% +use the Cork and not use the pitch and +they they were the ones who really + + align:start position:0% +they they were the ones who really + + + align:start position:0% +they they were the ones who really +perfected the use of corks in wine + + align:start position:0% +perfected the use of corks in wine + + + align:start position:0% +perfected the use of corks in wine +models for sealing it so what is cork um + + align:start position:0% +models for sealing it so what is cork um + + + align:start position:0% +models for sealing it so what is cork um +cork is the Bark of a tree called Quirk + + align:start position:0% +cork is the Bark of a tree called Quirk + + + align:start position:0% +cork is the Bark of a tree called Quirk +subber the cork oak and here's a piece + + align:start position:0% +subber the cork oak and here's a piece + + + align:start position:0% +subber the cork oak and here's a piece +of the cork bark and all all trees have + + align:start position:0% +of the cork bark and all all trees have + + + align:start position:0% +of the cork bark and all all trees have +a layer of cork in them but the thing + + align:start position:0% +a layer of cork in them but the thing + + + align:start position:0% +a layer of cork in them but the thing +that's different about corkus subber is + + align:start position:0% +that's different about corkus subber is + + + align:start position:0% +that's different about corkus subber is +that it's very thick and the corks are + + align:start position:0% +that it's very thick and the corks are + + + align:start position:0% +that it's very thick and the corks are +obtained from this thick layer and + + align:start position:0% +obtained from this thick layer and + + + align:start position:0% +obtained from this thick layer and +corkus subber is a Mediterranean type of + + align:start position:0% +corkus subber is a Mediterranean type of + + + align:start position:0% +corkus subber is a Mediterranean type of +tree it grows in Portugal is the main + + align:start position:0% +tree it grows in Portugal is the main + + + align:start position:0% +tree it grows in Portugal is the main +place that um exports cork but also + + align:start position:0% +place that um exports cork but also + + + align:start position:0% +place that um exports cork but also +places like Algeria Spain you can grow + + align:start position:0% +places like Algeria Spain you can grow + + + align:start position:0% +places like Algeria Spain you can grow +in California um and the cork is kind of + + align:start position:0% +in California um and the cork is kind of + + + align:start position:0% +in California um and the cork is kind of +unusual because let me uh scoot on to + + align:start position:0% +unusual because let me uh scoot on to + + + align:start position:0% +unusual because let me uh scoot on to +the next slide it's kind of unusual so + + align:start position:0% +the next slide it's kind of unusual so + + + align:start position:0% +the next slide it's kind of unusual so +here's a little picture I went to + + align:start position:0% +here's a little picture I went to + + + align:start position:0% +here's a little picture I went to +Portugal when I was a graduate student + + align:start position:0% +Portugal when I was a graduate student + + + align:start position:0% +Portugal when I was a graduate student +doing this project here's the cork tree + + align:start position:0% +doing this project here's the cork tree + + + align:start position:0% +doing this project here's the cork tree +here here's the little mini we rented um + + align:start position:0% +here here's the little mini we rented um + + + align:start position:0% +here here's the little mini we rented um +and here's the cork being harvested here + + align:start position:0% +and here's the cork being harvested here + + + align:start position:0% +and here's the cork being harvested here +and Cork's unusual because you can + + align:start position:0% +and Cork's unusual because you can + + + align:start position:0% +and Cork's unusual because you can +remove the bark from a cork oak tree and + + align:start position:0% +remove the bark from a cork oak tree and + + + align:start position:0% +remove the bark from a cork oak tree and +it regrows so most trees if you did this + + align:start position:0% +it regrows so most trees if you did this + + + align:start position:0% +it regrows so most trees if you did this +you would kill the tree but cork uh + + align:start position:0% +you would kill the tree but cork uh + + + align:start position:0% +you would kill the tree but cork uh +doesn't get killed by doing this and so + + align:start position:0% +doesn't get killed by doing this and so + + + align:start position:0% +doesn't get killed by doing this and so +what happens is they plant trees you + + align:start position:0% +what happens is they plant trees you + + + align:start position:0% +what happens is they plant trees you +have to wait something like 10 or 15 + + align:start position:0% +have to wait something like 10 or 15 + + + align:start position:0% +have to wait something like 10 or 15 +years for the first kind of you know the + + align:start position:0% +years for the first kind of you know the + + + align:start position:0% +years for the first kind of you know the +tree to get big enough to harvest the + + align:start position:0% +tree to get big enough to harvest the + + + align:start position:0% +tree to get big enough to harvest the +cork + + align:start position:0% +cork + + + align:start position:0% +cork +and then the first harvest um is poor + + align:start position:0% +and then the first harvest um is poor + + + align:start position:0% +and then the first harvest um is poor +quality and they don't use that and then + + align:start position:0% +quality and they don't use that and then + + + align:start position:0% +quality and they don't use that and then +you have to wait another 10 years or so + + align:start position:0% +you have to wait another 10 years or so + + + align:start position:0% +you have to wait another 10 years or so +before you can actually harvest the cork + + align:start position:0% +before you can actually harvest the cork + + + align:start position:0% +before you can actually harvest the cork +so you can kind of imagine if a cork + + align:start position:0% +so you can kind of imagine if a cork + + + align:start position:0% +so you can kind of imagine if a cork +Orchard or Forest gets you know chopped + + align:start position:0% +Orchard or Forest gets you know chopped + + + align:start position:0% +Orchard or Forest gets you know chopped +down to build a skyscraper you know + + align:start position:0% +down to build a skyscraper you know + + + align:start position:0% +down to build a skyscraper you know +apartment buildings or something um it's + + align:start position:0% +apartment buildings or something um it's + + + align:start position:0% +apartment buildings or something um it's +not sort of an economically feasible + + align:start position:0% +not sort of an economically feasible + + + align:start position:0% +not sort of an economically feasible +thing to plant cork trees these days so + + align:start position:0% +thing to plant cork trees these days so + + + align:start position:0% +thing to plant cork trees these days so +the cork tends to be uh when the trees + + align:start position:0% +the cork tends to be uh when the trees + + + align:start position:0% +the cork tends to be uh when the trees +are cut down they don't tend to get + + align:start position:0% +are cut down they don't tend to get + + + align:start position:0% +are cut down they don't tend to get +replanted at this point uh and there's a + + align:start position:0% +replanted at this point uh and there's a + + + align:start position:0% +replanted at this point uh and there's a +number of sort of artificial sub + + align:start position:0% +number of sort of artificial sub + + + align:start position:0% +number of sort of artificial sub +substitutes for corks you've probably + + align:start position:0% +substitutes for corks you've probably + + + align:start position:0% +substitutes for corks you've probably +seen wine bottles with foam plastic kind + + align:start position:0% +seen wine bottles with foam plastic kind + + + align:start position:0% +seen wine bottles with foam plastic kind +of corks in them too um okay and the + + align:start position:0% +of corks in them too um okay and the + + + align:start position:0% +of corks in them too um okay and the +reason it's called corkas subber is that + + align:start position:0% +reason it's called corkas subber is that + + + align:start position:0% +reason it's called corkas subber is that +the cell walls in this particular type + + align:start position:0% +the cell walls in this particular type + + + align:start position:0% +the cell walls in this particular type +of uh cork oak are covered with a waxy + + align:start position:0% +of uh cork oak are covered with a waxy + + + align:start position:0% +of uh cork oak are covered with a waxy +substance called subin and then that's + + align:start position:0% +substance called subin and then that's + + + align:start position:0% +substance called subin and then that's +where the quirkus Subarus quirkus is Oak + + align:start position:0% +where the quirkus Subarus quirkus is Oak + + + align:start position:0% +where the quirkus Subarus quirkus is Oak +so know every Oak is quirkus something + + align:start position:0% +so know every Oak is quirkus something + + + align:start position:0% +so know every Oak is quirkus something +quirkus Alba is White Oak so there's the + + align:start position:0% +quirkus Alba is White Oak so there's the + + + align:start position:0% +quirkus Alba is White Oak so there's the +quirkus is just means Oak so if we look + + align:start position:0% +quirkus is just means Oak so if we look + + + align:start position:0% +quirkus is just means Oak so if we look +at the structure of the cork we can see + + align:start position:0% +at the structure of the cork we can see + + + align:start position:0% +at the structure of the cork we can see +that it's got um these different uh sort + + align:start position:0% +that it's got um these different uh sort + + + align:start position:0% +that it's got um these different uh sort +of views of the cork that are seen here + + align:start position:0% +of views of the cork that are seen here + + + align:start position:0% +of views of the cork that are seen here +this is a drawing by Robert Hook in the + + align:start position:0% +this is a drawing by Robert Hook in the + + + align:start position:0% +this is a drawing by Robert Hook in the +1600s from his book micrographia he was + + align:start position:0% +1600s from his book micrographia he was + + + align:start position:0% +1600s from his book micrographia he was +the first person to really draw cork + + align:start position:0% +the first person to really draw cork + + + align:start position:0% +the first person to really draw cork +like this and you can see he drew sort + + align:start position:0% +like this and you can see he drew sort + + + align:start position:0% +like this and you can see he drew sort +of boxy uh cells on this side and then + + align:start position:0% +of boxy uh cells on this side and then + + + align:start position:0% +of boxy uh cells on this side and then +the other perpendicular plane the cells + + align:start position:0% +the other perpendicular plane the cells + + + align:start position:0% +the other perpendicular plane the cells +have this structure here sort of more + + align:start position:0% +have this structure here sort of more + + + align:start position:0% +have this structure here sort of more +rounded and here's a little sketch she's + + align:start position:0% +rounded and here's a little sketch she's + + + align:start position:0% +rounded and here's a little sketch she's +got of the cork tree and over here are + + align:start position:0% +got of the cork tree and over here are + + + align:start position:0% +got of the cork tree and over here are +sem pictures and these two um planes + + align:start position:0% +sem pictures and these two um planes + + + align:start position:0% +sem pictures and these two um planes +here correspond to this plane in hooks + + align:start position:0% +here correspond to this plane in hooks + + + align:start position:0% +here correspond to this plane in hooks +drawing and this plane here corresponds + + align:start position:0% +drawing and this plane here corresponds + + + align:start position:0% +drawing and this plane here corresponds +to this plane here and this over here is + + align:start position:0% +to this plane here and this over here is + + + align:start position:0% +to this plane here and this over here is +Hook's actual microscope um and I think + + align:start position:0% +Hook's actual microscope um and I think + + + align:start position:0% +Hook's actual microscope um and I think +the Royal Society still has that uh + + align:start position:0% +the Royal Society still has that uh + + + align:start position:0% +the Royal Society still has that uh +microscope that hook used in the 1600s + + align:start position:0% +microscope that hook used in the 1600s + + + align:start position:0% +microscope that hook used in the 1600s +and some of you know that hook wrote + + align:start position:0% +and some of you know that hook wrote + + + align:start position:0% +and some of you know that hook wrote +this book called micrographia he got one + + align:start position:0% +this book called micrographia he got one + + + align:start position:0% +this book called micrographia he got one +of the first microscopes and he looked + + align:start position:0% +of the first microscopes and he looked + + + align:start position:0% +of the first microscopes and he looked +at a lot of different materials and he + + align:start position:0% +at a lot of different materials and he + + + align:start position:0% +at a lot of different materials and he +drew these beautiful drawings and he + + align:start position:0% +drew these beautiful drawings and he + + + align:start position:0% +drew these beautiful drawings and he +wrote a page or two about each of the + + align:start position:0% +wrote a page or two about each of the + + + align:start position:0% +wrote a page or two about each of the +drawings and Harvard has a first edition + + align:start position:0% +drawings and Harvard has a first edition + + + align:start position:0% +drawings and Harvard has a first edition +of micrographia and I made a little + + align:start position:0% +of micrographia and I made a little + + + align:start position:0% +of micrographia and I made a little +video on it so I thought I'd show you + + align:start position:0% +video on it so I thought I'd show you + + + align:start position:0% +video on it so I thought I'd show you +the video because it's just so the + + align:start position:0% +the video because it's just so the + + + align:start position:0% +the video because it's just so the +drawings are beautiful but the um the + + align:start position:0% +drawings are beautiful but the um the + + + align:start position:0% +drawings are beautiful but the um the +url's on the slides and so you can watch + + align:start position:0% +url's on the slides and so you can watch + + + align:start position:0% +url's on the slides and so you can watch +it yourself so there's more on this on + + align:start position:0% +it yourself so there's more on this on + + + align:start position:0% +it yourself so there's more on this on +uh how he came to be so good at making + + align:start position:0% +uh how he came to be so good at making + + + align:start position:0% +uh how he came to be so good at making +scientific apparatus uh how he came to + + align:start position:0% +scientific apparatus uh how he came to + + + align:start position:0% +scientific apparatus uh how he came to +do the micrographia book and at the end + + align:start position:0% +do the micrographia book and at the end + + + align:start position:0% +do the micrographia book and at the end +of it there's a comparison of a number + + align:start position:0% +of it there's a comparison of a number + + + align:start position:0% +of it there's a comparison of a number +of his drawings with modern sem images + + align:start position:0% +of his drawings with modern sem images + + + align:start position:0% +of his drawings with modern sem images +of the same thing so he there a very + + align:start position:0% +of the same thing so he there a very + + + align:start position:0% +of the same thing so he there a very +famous picture where he draws a flea and + + align:start position:0% +famous picture where he draws a flea and + + + align:start position:0% +famous picture where he draws a flea and +the Don Galler the person who runs the + + align:start position:0% +the Don Galler the person who runs the + + + align:start position:0% +the Don Galler the person who runs the +sem for me I had him put a flea in and + + align:start position:0% +sem for me I had him put a flea in and + + + align:start position:0% +sem for me I had him put a flea in and +he has essentially the same kind of draw + + align:start position:0% +he has essentially the same kind of draw + + + align:start position:0% +he has essentially the same kind of draw +the same kind of image and the thing + + align:start position:0% +the same kind of image and the thing + + + align:start position:0% +the same kind of image and the thing +it's spectacular is you can see how much + + align:start position:0% +it's spectacular is you can see how much + + + align:start position:0% +it's spectacular is you can see how much +of the detail that hook was able to + + align:start position:0% +of the detail that hook was able to + + + align:start position:0% +of the detail that hook was able to +capture in his drawings there's some + + align:start position:0% +capture in his drawings there's some + + + align:start position:0% +capture in his drawings there's some +really beautiful drawings okay so let's + + align:start position:0% +really beautiful drawings okay so let's + + + align:start position:0% +really beautiful drawings okay so let's +go back to Cork and Hook was the first + + align:start position:0% +go back to Cork and Hook was the first + + + align:start position:0% +go back to Cork and Hook was the first +person to use the word cell to describe + + align:start position:0% +person to use the word cell to describe + + + align:start position:0% +person to use the word cell to describe +biological cells and he described the + + align:start position:0% +biological cells and he described the + + + align:start position:0% +biological cells and he described the +cell in Cork so that's the structure + + align:start position:0% +cell in Cork so that's the structure + + + align:start position:0% +cell in Cork so that's the structure +looking at um you know the the sem + + align:start position:0% +looking at um you know the the sem + + + align:start position:0% +looking at um you know the the sem +micrographs and and his optical + + align:start position:0% +micrographs and and his optical + + + align:start position:0% +micrographs and and his optical +micrographs and these are just some more + + align:start position:0% +micrographs and these are just some more + + + align:start position:0% +micrographs and these are just some more +higher resolution higher magnification + + align:start position:0% +higher resolution higher magnification + + + align:start position:0% +higher resolution higher magnification +images and one of the things that you + + align:start position:0% +images and one of the things that you + + + align:start position:0% +images and one of the things that you +can see is that the cork has these + + align:start position:0% +can see is that the cork has these + + + align:start position:0% +can see is that the cork has these +little corrugations on the cell wall see + + align:start position:0% +little corrugations on the cell wall see + + + align:start position:0% +little corrugations on the cell wall see +those little kind of wrinkles so all the + + align:start position:0% +those little kind of wrinkles so all the + + + align:start position:0% +those little kind of wrinkles so all the +cell walls have those little wrinkles + + align:start position:0% +cell walls have those little wrinkles + + + align:start position:0% +cell walls have those little wrinkles +This Plane here is the perpendicular + + align:start position:0% +This Plane here is the perpendicular + + + align:start position:0% +This Plane here is the perpendicular +plane and if you look down sort of into + + align:start position:0% +plane and if you look down sort of into + + + align:start position:0% +plane and if you look down sort of into +the cells you can see those kind of + + align:start position:0% +the cells you can see those kind of + + + align:start position:0% +the cells you can see those kind of +blurry things those are the corrugations + + align:start position:0% +blurry things those are the corrugations + + + align:start position:0% +blurry things those are the corrugations +in the cell walls so that's the + + align:start position:0% +in the cell walls so that's the + + + align:start position:0% +in the cell walls so that's the +structure uh here's a schematic uh so + + align:start position:0% +structure uh here's a schematic uh so + + + align:start position:0% +structure uh here's a schematic uh so +here's the cork tree the cork is the + + align:start position:0% +here's the cork tree the cork is the + + + align:start position:0% +here's the cork tree the cork is the +layer just beneath the bark and then + + align:start position:0% +layer just beneath the bark and then + + + align:start position:0% +layer just beneath the bark and then +this is sort of a picture of how the + + align:start position:0% +this is sort of a picture of how the + + + align:start position:0% +this is sort of a picture of how the +cells are oriented relative to the + + align:start position:0% +cells are oriented relative to the + + + align:start position:0% +cells are oriented relative to the +radial and tangential and axial + + align:start position:0% +radial and tangential and axial + + + align:start position:0% +radial and tangential and axial +directions and you can think of them as + + align:start position:0% +directions and you can think of them as + + + align:start position:0% +directions and you can think of them as +roughly hexagonal they've got these + + align:start position:0% +roughly hexagonal they've got these + + + align:start position:0% +roughly hexagonal they've got these +little corrugations so this is kind of a + + align:start position:0% +little corrugations so this is kind of a + + + align:start position:0% +little corrugations so this is kind of a +schematic of an individual cell and uh + + align:start position:0% +schematic of an individual cell and uh + + + align:start position:0% +schematic of an individual cell and uh +we measured the dimensions of the cells + + align:start position:0% +we measured the dimensions of the cells + + + align:start position:0% +we measured the dimensions of the cells +and these are some average Dimensions + + align:start position:0% +and these are some average Dimensions + + + align:start position:0% +and these are some average Dimensions +here so typically the cells are tens of + + align:start position:0% +here so typically the cells are tens of + + + align:start position:0% +here so typically the cells are tens of +microns long and the cell wall is about + + align:start position:0% +microns long and the cell wall is about + + + align:start position:0% +microns long and the cell wall is about +a micron thick something like that okay + + align:start position:0% +a micron thick something like that okay + + + align:start position:0% +a micron thick something like that okay +and one of the things we're going to see + + align:start position:0% +and one of the things we're going to see + + + align:start position:0% +and one of the things we're going to see +is that that corrugated structure gives + + align:start position:0% +is that that corrugated structure gives + + + align:start position:0% +is that that corrugated structure gives +rise to some of the interesting + + align:start position:0% +rise to some of the interesting + + + align:start position:0% +rise to some of the interesting +properties of + + align:start position:0% +properties of + + + align:start position:0% +properties of +cork okay so if we load Cork and just do + + align:start position:0% +cork okay so if we load Cork and just do + + + align:start position:0% +cork okay so if we load Cork and just do +mechanical tests on it this is just a + + align:start position:0% +mechanical tests on it this is just a + + + align:start position:0% +mechanical tests on it this is just a +uni aial stress strain curve um you can + + align:start position:0% +uni aial stress strain curve um you can + + + align:start position:0% +uni aial stress strain curve um you can +see the stress strain curve looks like + + align:start position:0% +see the stress strain curve looks like + + + align:start position:0% +see the stress strain curve looks like +all these other curves we've seen for + + align:start position:0% +all these other curves we've seen for + + + align:start position:0% +all these other curves we've seen for +Honeycombs there's a linear elastic part + + align:start position:0% +Honeycombs there's a linear elastic part + + + align:start position:0% +Honeycombs there's a linear elastic part +here there's a stress Plateau here and + + align:start position:0% +here there's a stress Plateau here and + + + align:start position:0% +here there's a stress Plateau here and +then there's a densification part here + + align:start position:0% +then there's a densification part here + + + align:start position:0% +then there's a densification part here +and typically the relative density of + + align:start position:0% +and typically the relative density of + + + align:start position:0% +and typically the relative density of +cork is around 0.15 something like that + + align:start position:0% +cork is around 0.15 something like that + + + align:start position:0% +cork is around 0.15 something like that +so uh so it densifies I at a strain of + + align:start position:0% +so uh so it densifies I at a strain of + + + align:start position:0% +so uh so it densifies I at a strain of +something less than 85 something like + + align:start position:0% +something less than 85 something like + + + align:start position:0% +something less than 85 something like +that so it's a stress strain curve and + + align:start position:0% +that so it's a stress strain curve and + + + align:start position:0% +that so it's a stress strain curve and +when we did our little project on Cor we + + align:start position:0% +when we did our little project on Cor we + + + align:start position:0% +when we did our little project on Cor we +measured the properties in the three + + align:start position:0% +measured the properties in the three + + + align:start position:0% +measured the properties in the three +directions um because in in One + + align:start position:0% +directions um because in in One + + + align:start position:0% +directions um because in in One +Direction it's roughly hexagonal cells + + align:start position:0% +Direction it's roughly hexagonal cells + + + align:start position:0% +Direction it's roughly hexagonal cells +that that plane is isotropic so the E1 + + align:start position:0% +that that plane is isotropic so the E1 + + + align:start position:0% +that that plane is isotropic so the E1 +E2 plane is + + align:start position:0% +E2 plane is + + + align:start position:0% +E2 plane is +isotropic and this compares the measured + + align:start position:0% +isotropic and this compares the measured + + + align:start position:0% +isotropic and this compares the measured +values of the properties versus what we + + align:start position:0% +values of the properties versus what we + + + align:start position:0% +values of the properties versus what we +calculated from the honeycomb model and + + align:start position:0% +calculated from the honeycomb model and + + + align:start position:0% +calculated from the honeycomb model and +really we just Ed the sorts of equations + + align:start position:0% +really we just Ed the sorts of equations + + + align:start position:0% +really we just Ed the sorts of equations +that we talked about in over the last + + align:start position:0% +that we talked about in over the last + + + align:start position:0% +that we talked about in over the last +couple of lectures apart from loading in + + align:start position:0% +couple of lectures apart from loading in + + + align:start position:0% +couple of lectures apart from loading in +the X3 Direction because in the X3 + + align:start position:0% +the X3 Direction because in the X3 + + + align:start position:0% +the X3 Direction because in the X3 +Direction you've got those corrugated + + align:start position:0% +Direction you've got those corrugated + + + align:start position:0% +Direction you've got those corrugated +walls and you have to take those + + align:start position:0% +walls and you have to take those + + + align:start position:0% +walls and you have to take those +corrugations into account so there's + + align:start position:0% +corrugations into account so there's + + + align:start position:0% +corrugations into account so there's +another complication that I'm I'm not + + align:start position:0% +another complication that I'm I'm not + + + align:start position:0% +another complication that I'm I'm not +going to go into but there's a sort of + + align:start position:0% +going to go into but there's a sort of + + + align:start position:0% +going to go into but there's a sort of +modification you can do to account for + + align:start position:0% +modification you can do to account for + + + align:start position:0% +modification you can do to account for +that but you can see there's actually + + align:start position:0% +that but you can see there's actually + + + align:start position:0% +that but you can see there's actually +pretty good agreement here between uh + + align:start position:0% +pretty good agreement here between uh + + + align:start position:0% +pretty good agreement here between uh +the elastic moduli that we measured and + + align:start position:0% +the elastic moduli that we measured and + + + align:start position:0% +the elastic moduli that we measured and +what we calculated the compressive + + align:start position:0% +what we calculated the compressive + + + align:start position:0% +what we calculated the compressive +strengths down here are not quite so + + align:start position:0% +strengths down here are not quite so + + + align:start position:0% +strengths down here are not quite so +good they're off by a factor of two more + + align:start position:0% +good they're off by a factor of two more + + + align:start position:0% +good they're off by a factor of two more +or less um but they're in the in the + + align:start position:0% +or less um but they're in the in the + + + align:start position:0% +or less um but they're in the in the +right ballpark for the um + + align:start position:0% +right ballpark for the um + + + align:start position:0% +right ballpark for the um +for the cork so those are some of the + + align:start position:0% +for the cork so those are some of the + + + align:start position:0% +for the cork so those are some of the +structures uh some of the properties and + + align:start position:0% +structures uh some of the properties and + + + align:start position:0% +structures uh some of the properties and +one of the interesting things about cork + + align:start position:0% +one of the interesting things about cork + + + align:start position:0% +one of the interesting things about cork +is is what it's used for and the uses of + + align:start position:0% +is is what it's used for and the uses of + + + align:start position:0% +is is what it's used for and the uses of +cork really exploit the mechanical + + align:start position:0% +cork really exploit the mechanical + + + align:start position:0% +cork really exploit the mechanical +properties so obviously it's used for + + align:start position:0% +properties so obviously it's used for + + + align:start position:0% +properties so obviously it's used for +stoppers for bottles I brought a + + align:start position:0% +stoppers for bottles I brought a + + + align:start position:0% +stoppers for bottles I brought a +champagne cork along with me and I + + align:start position:0% +champagne cork along with me and I + + + align:start position:0% +champagne cork along with me and I +brought a couple of other little pieces + + align:start position:0% +brought a couple of other little pieces + + + align:start position:0% +brought a couple of other little pieces +of cork here I'll pass those around in a + + align:start position:0% +of cork here I'll pass those around in a + + + align:start position:0% +of cork here I'll pass those around in a +minute um so one of the things to look + + align:start position:0% +minute um so one of the things to look + + + align:start position:0% +minute um so one of the things to look +at is just the the still wine cork which + + align:start position:0% +at is just the the still wine cork which + + + align:start position:0% +at is just the the still wine cork which +is the one on the right and the + + align:start position:0% +is the one on the right and the + + + align:start position:0% +is the one on the right and the +champagne cork which is the one on the + + align:start position:0% +champagne cork which is the one on the + + + align:start position:0% +champagne cork which is the one on the +left um if you notice the the still wine + + align:start position:0% +left um if you notice the the still wine + + + align:start position:0% +left um if you notice the the still wine +cork is just made of one piece of cork + + align:start position:0% +cork is just made of one piece of cork + + + align:start position:0% +cork is just made of one piece of cork +that's CED out from the + + align:start position:0% +that's CED out from the + + + align:start position:0% +that's CED out from the +bark and if you notice there little + + align:start position:0% +bark and if you notice there little + + + align:start position:0% +bark and if you notice there little +channels these little channels here are + + align:start position:0% +channels these little channels here are + + + align:start position:0% +channels these little channels here are +called lenticels and on the still wine + + align:start position:0% +called lenticels and on the still wine + + + align:start position:0% +called lenticels and on the still wine +cork they go this way and on the + + align:start position:0% +cork they go this way and on the + + + align:start position:0% +cork they go this way and on the +champagne cork they go that way they're + + align:start position:0% +champagne cork they go that way they're + + + align:start position:0% +champagne cork they go that way they're +oriented perpendicular and it turns out + + align:start position:0% +oriented perpendicular and it turns out + + + align:start position:0% +oriented perpendicular and it turns out +that they are normal to the isotropic + + align:start position:0% +that they are normal to the isotropic + + + align:start position:0% +that they are normal to the isotropic +plane in the cork so if you look at the + + align:start position:0% +plane in the cork so if you look at the + + + align:start position:0% +plane in the cork so if you look at the +champagne cork This Plane here this + + align:start position:0% +champagne cork This Plane here this + + + align:start position:0% +champagne cork This Plane here this +plane here is the isotropic plane and so + + align:start position:0% +plane here is the isotropic plane and so + + + align:start position:0% +plane here is the isotropic plane and so +if you think of that being put into a + + align:start position:0% +if you think of that being put into a + + + align:start position:0% +if you think of that being put into a +bottle um I think part of the reason + + align:start position:0% +bottle um I think part of the reason + + + align:start position:0% +bottle um I think part of the reason +they Orient it this way is because it it + + align:start position:0% +they Orient it this way is because it it + + + align:start position:0% +they Orient it this way is because it it +gives you a uniform kind of compression + + align:start position:0% +gives you a uniform kind of compression + + + align:start position:0% +gives you a uniform kind of compression +against the neck of the bottle and gives + + align:start position:0% +against the neck of the bottle and gives + + + align:start position:0% +against the neck of the bottle and gives +a nice seal so that's one of the things + + align:start position:0% +a nice seal so that's one of the things + + + align:start position:0% +a nice seal so that's one of the things +about uh corks another thing that's + + align:start position:0% +about uh corks another thing that's + + + align:start position:0% +about uh corks another thing that's +interesting is that cork has a pom's + + align:start position:0% +interesting is that cork has a pom's + + + align:start position:0% +interesting is that cork has a pom's +ratio equal to um to zero if you load it + + align:start position:0% +ratio equal to um to zero if you load it + + + align:start position:0% +ratio equal to um to zero if you load it +in that direction oops uh let's see did + + align:start position:0% +in that direction oops uh let's see did + + + align:start position:0% +in that direction oops uh let's see did +I not bring that picture maybe I didn't + + align:start position:0% +I not bring that picture maybe I didn't + + + align:start position:0% +I not bring that picture maybe I didn't +bring that picture hang on a sec nope I + + align:start position:0% +bring that picture hang on a sec nope I + + + align:start position:0% +bring that picture hang on a sec nope I +guess I didn't sorry I thought I brought + + align:start position:0% +guess I didn't sorry I thought I brought + + + align:start position:0% +guess I didn't sorry I thought I brought +a picture where I had the um the + + align:start position:0% +a picture where I had the um the + + + align:start position:0% +a picture where I had the um the +deformation of the cells when you load + + align:start position:0% +deformation of the cells when you load + + + align:start position:0% +deformation of the cells when you load +it in that direction when you load it so + + align:start position:0% +it in that direction when you load it so + + + align:start position:0% +it in that direction when you load it so +say the cells are corrugated this way on + + align:start position:0% +say the cells are corrugated this way on + + + align:start position:0% +say the cells are corrugated this way on +when you load it that way on uh it's + + align:start position:0% +when you load it that way on uh it's + + + align:start position:0% +when you load it that way on uh it's +like having a Bellow and folding up a + + align:start position:0% +like having a Bellow and folding up a + + + align:start position:0% +like having a Bellow and folding up a +Bellow or unfolding a Bellows so when + + align:start position:0% +Bellow or unfolding a Bellows so when + + + align:start position:0% +Bellow or unfolding a Bellows so when +you load it that way on there's no + + align:start position:0% +you load it that way on there's no + + + align:start position:0% +you load it that way on there's no +expansion or contraction this way on and + + align:start position:0% +expansion or contraction this way on and + + + align:start position:0% +expansion or contraction this way on and +so you get a zero POS ratio and if you + + align:start position:0% +so you get a zero POS ratio and if you + + + align:start position:0% +so you get a zero POS ratio and if you +think of trying to get the cork into the + + align:start position:0% +think of trying to get the cork into the + + + align:start position:0% +think of trying to get the cork into the +bottle it's rather convenient to have a + + align:start position:0% +bottle it's rather convenient to have a + + + align:start position:0% +bottle it's rather convenient to have a +zero Pence ratio because you don't get + + align:start position:0% +zero Pence ratio because you don't get + + + align:start position:0% +zero Pence ratio because you don't get +as much expansion you know as you're + + align:start position:0% +as much expansion you know as you're + + + align:start position:0% +as much expansion you know as you're +pushing it into the bottle and you don't + + align:start position:0% +pushing it into the bottle and you don't + + + align:start position:0% +pushing it into the bottle and you don't +get as much expansion expansion that way + + align:start position:0% +get as much expansion expansion that way + + + align:start position:0% +get as much expansion expansion that way +out pressing against it and in fact if + + align:start position:0% +out pressing against it and in fact if + + + align:start position:0% +out pressing against it and in fact if +you compare wine corks with rubber + + align:start position:0% +you compare wine corks with rubber + + + align:start position:0% +you compare wine corks with rubber +stoppers this is a kind of you know your + + align:start position:0% +stoppers this is a kind of you know your + + + align:start position:0% +stoppers this is a kind of you know your +typical rubber stopper wine corks are + + align:start position:0% +typical rubber stopper wine corks are + + + align:start position:0% +typical rubber stopper wine corks are +almost just cylinders and in fact even + + align:start position:0% +almost just cylinders and in fact even + + + align:start position:0% +almost just cylinders and in fact even +the champagne corks are cylinders when + + align:start position:0% +the champagne corks are cylinders when + + + align:start position:0% +the champagne corks are cylinders when +they start off when they put it into the + + align:start position:0% +they start off when they put it into the + + + align:start position:0% +they start off when they put it into the +bottle it's just a straight cylinder and + + align:start position:0% +bottle it's just a straight cylinder and + + + align:start position:0% +bottle it's just a straight cylinder and +it gets deformed like that from being in + + align:start position:0% +it gets deformed like that from being in + + + align:start position:0% +it gets deformed like that from being in +the bottle for some time so they have + + align:start position:0% +the bottle for some time so they have + + + align:start position:0% +the bottle for some time so they have +straight sides and you can just squeeze + + align:start position:0% +straight sides and you can just squeeze + + + align:start position:0% +straight sides and you can just squeeze +them there there kind of these funnel + + align:start position:0% +them there there kind of these funnel + + + align:start position:0% +them there there kind of these funnel +things that wine makers have for putting + + align:start position:0% +things that wine makers have for putting + + + align:start position:0% +things that wine makers have for putting +the cork in the bottle uh and you can + + align:start position:0% +the cork in the bottle uh and you can + + + align:start position:0% +the cork in the bottle uh and you can +just kind of squeeze them into the + + align:start position:0% +just kind of squeeze them into the + + + align:start position:0% +just kind of squeeze them into the +bottle top and you can do that because + + align:start position:0% +bottle top and you can do that because + + + align:start position:0% +bottle top and you can do that because +the Pence ratio is zero and because the + + align:start position:0% +the Pence ratio is zero and because the + + + align:start position:0% +the Pence ratio is zero and because the +Young's modulus and the bulk modulus are + + align:start position:0% +Young's modulus and the bulk modulus are + + + align:start position:0% +Young's modulus and the bulk modulus are +both small but if you look at a rubber + + align:start position:0% +both small but if you look at a rubber + + + align:start position:0% +both small but if you look at a rubber +stopper rubber stoppers always have + + align:start position:0% +stopper rubber stoppers always have + + + align:start position:0% +stopper rubber stoppers always have +these tapered um sides to them and + + align:start position:0% +these tapered um sides to them and + + + align:start position:0% +these tapered um sides to them and +that's because the poson ratio of the + + align:start position:0% +that's because the poson ratio of the + + + align:start position:0% +that's because the poson ratio of the +rubber is 0.5 and so as you squeeze it + + align:start position:0% +rubber is 0.5 and so as you squeeze it + + + align:start position:0% +rubber is 0.5 and so as you squeeze it +in it's trying to you know move out this + + align:start position:0% +in it's trying to you know move out this + + + align:start position:0% +in it's trying to you know move out this +way and you couldn't get the stopper in + + align:start position:0% +way and you couldn't get the stopper in + + + align:start position:0% +way and you couldn't get the stopper in +unless it had those tapered sides so + + align:start position:0% +unless it had those tapered sides so + + + align:start position:0% +unless it had those tapered sides so +that's just sort of an interesting thing + + align:start position:0% +that's just sort of an interesting thing + + + align:start position:0% +that's just sort of an interesting thing +about cork let's see another application + + align:start position:0% +about cork let's see another application + + + align:start position:0% +about cork let's see another application +of cork is it's used for gaskets for the + + align:start position:0% +of cork is it's used for gaskets for the + + + align:start position:0% +of cork is it's used for gaskets for the +same sorts of reasons It's relatively + + align:start position:0% +same sorts of reasons It's relatively + + + align:start position:0% +same sorts of reasons It's relatively +compliant uh and so it sort of takes up + + align:start position:0% +compliant uh and so it sort of takes up + + + align:start position:0% +compliant uh and so it sort of takes up +any slack between two pieces that you + + align:start position:0% +any slack between two pieces that you + + + align:start position:0% +any slack between two pieces that you +want to press together it's often used + + align:start position:0% +want to press together it's often used + + + align:start position:0% +want to press together it's often used +for musical instruments that come in + + align:start position:0% +for musical instruments that come in + + + align:start position:0% +for musical instruments that come in +pieces things like clarinet they'll be a + + align:start position:0% +pieces things like clarinet they'll be a + + + align:start position:0% +pieces things like clarinet they'll be a +piece of are you a clarinet player + + align:start position:0% +piece of are you a clarinet player + + + align:start position:0% +piece of are you a clarinet player +you're nodding yeah yeah so one of the + + align:start position:0% +you're nodding yeah yeah so one of the + + + align:start position:0% +you're nodding yeah yeah so one of the +interesting things about the clarinet is + + align:start position:0% +interesting things about the clarinet is + + + align:start position:0% +interesting things about the clarinet is +that if you can see here at the ends + + align:start position:0% +that if you can see here at the ends + + + align:start position:0% +that if you can see here at the ends +there's a piece of cork there and I + + align:start position:0% +there's a piece of cork there and I + + + align:start position:0% +there's a piece of cork there and I +think there's a piece of cork down there + + align:start position:0% +think there's a piece of cork down there + + + align:start position:0% +think there's a piece of cork down there +and the other pieces you know mate up + + align:start position:0% +and the other pieces you know mate up + + + align:start position:0% +and the other pieces you know mate up +with that and the cork provides kind of + + align:start position:0% +with that and the cork provides kind of + + + align:start position:0% +with that and the cork provides kind of +a seal and the way the cork is cut it's + + align:start position:0% +a seal and the way the cork is cut it's + + + align:start position:0% +a seal and the way the cork is cut it's +cut in such a way that those lenticles + + align:start position:0% +cut in such a way that those lenticles + + + align:start position:0% +cut in such a way that those lenticles +go kind of r out like this which means + + align:start position:0% +go kind of r out like this which means + + + align:start position:0% +go kind of r out like this which means +that the plane of isotropy and the plane + + align:start position:0% +that the plane of isotropy and the plane + + + align:start position:0% +that the plane of isotropy and the plane +that's got the or the direction that's + + align:start position:0% +that's got the or the direction that's + + + align:start position:0% +that's got the or the direction that's +got the zero poson ratio is sort of that + + align:start position:0% +got the zero poson ratio is sort of that + + + align:start position:0% +got the zero poson ratio is sort of that +um radial Direction and so when you're + + align:start position:0% +um radial Direction and so when you're + + + align:start position:0% +um radial Direction and so when you're +squeezing the you know say the second + + align:start position:0% +squeezing the you know say the second + + + align:start position:0% +squeezing the you know say the second +part onto it um the cork does not expand + + align:start position:0% +part onto it um the cork does not expand + + + align:start position:0% +part onto it um the cork does not expand +circumferentially so as you're squeezing + + align:start position:0% +circumferentially so as you're squeezing + + + align:start position:0% +circumferentially so as you're squeezing +it this way it doesn't expand that way + + align:start position:0% +it this way it doesn't expand that way + + + align:start position:0% +it this way it doesn't expand that way +and so it doesn't wrinkle or anything on + + align:start position:0% +and so it doesn't wrinkle or anything on + + + align:start position:0% +and so it doesn't wrinkle or anything on +your other part so they sort of use the + + align:start position:0% +your other part so they sort of use the + + + align:start position:0% +your other part so they sort of use the +cork in a particular orientation for + + align:start position:0% +cork in a particular orientation for + + + align:start position:0% +cork in a particular orientation for +that reason I think so it's used for + + align:start position:0% +that reason I think so it's used for + + + align:start position:0% +that reason I think so it's used for +gaskets uh it's also used because it's + + align:start position:0% +gaskets uh it's also used because it's + + + align:start position:0% +gaskets uh it's also used because it's +got um sort of a good friction + + align:start position:0% +got um sort of a good friction + + + align:start position:0% +got um sort of a good friction +properties it's got the a property that + + align:start position:0% +properties it's got the a property that + + + align:start position:0% +properties it's got the a property that +uh is taken advantage of in things like + + align:start position:0% +uh is taken advantage of in things like + + + align:start position:0% +uh is taken advantage of in things like +flooring and shoes uh cork has high + + align:start position:0% +flooring and shoes uh cork has high + + + align:start position:0% +flooring and shoes uh cork has high +friction even if it gets wet so some + + align:start position:0% +friction even if it gets wet so some + + + align:start position:0% +friction even if it gets wet so some +sources of friction are from adhesion + + align:start position:0% +sources of friction are from adhesion + + + align:start position:0% +sources of friction are from adhesion +from sort of a surface effect and then + + align:start position:0% +from sort of a surface effect and then + + + align:start position:0% +from sort of a surface effect and then +if say the floor gets wet then uh you + + align:start position:0% +if say the floor gets wet then uh you + + + align:start position:0% +if say the floor gets wet then uh you +break that and it could be slippery but + + align:start position:0% +break that and it could be slippery but + + + align:start position:0% +break that and it could be slippery but +the source of friction in Cork is from + + align:start position:0% +the source of friction in Cork is from + + + align:start position:0% +the source of friction in Cork is from +um an energy loss and dissipation as + + align:start position:0% +um an energy loss and dissipation as + + + align:start position:0% +um an energy loss and dissipation as +you're deforming it so imagine you have + + align:start position:0% +you're deforming it so imagine you have + + + align:start position:0% +you're deforming it so imagine you have +a wheel here and the wheel is rotating + + align:start position:0% +a wheel here and the wheel is rotating + + + align:start position:0% +a wheel here and the wheel is rotating +on this cork floor and here a piece of + + align:start position:0% +on this cork floor and here a piece of + + + align:start position:0% +on this cork floor and here a piece of +cork is getting deformed as the wheel + + align:start position:0% +cork is getting deformed as the wheel + + + align:start position:0% +cork is getting deformed as the wheel +rolls over it and as it gets deformed uh + + align:start position:0% +rolls over it and as it gets deformed uh + + + align:start position:0% +rolls over it and as it gets deformed uh +there's some hysteresis Loop and cork + + align:start position:0% +there's some hysteresis Loop and cork + + + align:start position:0% +there's some hysteresis Loop and cork +has quite a lot of damping in it there's + + align:start position:0% +has quite a lot of damping in it there's + + + align:start position:0% +has quite a lot of damping in it there's +quite a lot of energy lost in that + + align:start position:0% +quite a lot of energy lost in that + + + align:start position:0% +quite a lot of energy lost in that +hysteresis Loop and what that means is + + align:start position:0% +hysteresis Loop and what that means is + + + align:start position:0% +hysteresis Loop and what that means is +that's sort of characteristic of of the + + align:start position:0% +that's sort of characteristic of of the + + + align:start position:0% +that's sort of characteristic of of the +cork itself and it's not a surface + + align:start position:0% +cork itself and it's not a surface + + + align:start position:0% +cork itself and it's not a surface +effect and that means that if you use it + + align:start position:0% +effect and that means that if you use it + + + align:start position:0% +effect and that means that if you use it +for floors or for shoes that um it + + align:start position:0% +for floors or for shoes that um it + + + align:start position:0% +for floors or for shoes that um it +doesn't lose that friction + + align:start position:0% +doesn't lose that friction + + + align:start position:0% +doesn't lose that friction +uh and damping when it gets wet so + + align:start position:0% +uh and damping when it gets wet so + + + align:start position:0% +uh and damping when it gets wet so +here's some measurements we did of the + + align:start position:0% +here's some measurements we did of the + + + align:start position:0% +here's some measurements we did of the +coefficient of friction for cork versus + + align:start position:0% +coefficient of friction for cork versus + + + align:start position:0% +coefficient of friction for cork versus +uh doing it dry and doing it with sort + + align:start position:0% +uh doing it dry and doing it with sort + + + align:start position:0% +uh doing it dry and doing it with sort +of a a liquid soapy surface and you can + + align:start position:0% +of a a liquid soapy surface and you can + + + align:start position:0% +of a a liquid soapy surface and you can +see the soap doesn't make any difference + + align:start position:0% +see the soap doesn't make any difference + + + align:start position:0% +see the soap doesn't make any difference +and cork is uh seen as a very attractive + + align:start position:0% +and cork is uh seen as a very attractive + + + align:start position:0% +and cork is uh seen as a very attractive +material for things like flooring um so + + align:start position:0% +material for things like flooring um so + + + align:start position:0% +material for things like flooring um so +it's actually not a cheap material to + + align:start position:0% +it's actually not a cheap material to + + + align:start position:0% +it's actually not a cheap material to +make your floors out of but uh it's kind + + align:start position:0% +make your floors out of but uh it's kind + + + align:start position:0% +make your floors out of but uh it's kind +of an attractive material for flooring + + align:start position:0% +of an attractive material for flooring + + + align:start position:0% +of an attractive material for flooring +and part of the reason it's used for + + align:start position:0% +and part of the reason it's used for + + + align:start position:0% +and part of the reason it's used for +floors and for the soles of shoes is + + align:start position:0% +floors and for the soles of shoes is + + + align:start position:0% +floors and for the soles of shoes is +because of these friction uh properties + + align:start position:0% +because of these friction uh properties + + + align:start position:0% +because of these friction uh properties +another feature of cork is that it's got + + align:start position:0% +another feature of cork is that it's got + + + align:start position:0% +another feature of cork is that it's got +very small cells compared to a lot of + + align:start position:0% +very small cells compared to a lot of + + + align:start position:0% +very small cells compared to a lot of +engineering polymers the cells are on + + align:start position:0% +engineering polymers the cells are on + + + align:start position:0% +engineering polymers the cells are on +the order of tens of microns whereas + + align:start position:0% +the order of tens of microns whereas + + + align:start position:0% +the order of tens of microns whereas +many polymer Foams the cells are + + align:start position:0% +many polymer Foams the cells are + + + align:start position:0% +many polymer Foams the cells are +hundreds of microns or millimeters and + + align:start position:0% +hundreds of microns or millimeters and + + + align:start position:0% +hundreds of microns or millimeters and +we'll get into this later but this plot + + align:start position:0% +we'll get into this later but this plot + + + align:start position:0% +we'll get into this later but this plot +here is really saying that the thermal + + align:start position:0% +here is really saying that the thermal + + + align:start position:0% +here is really saying that the thermal +conductivity of a cellular material + + align:start position:0% +conductivity of a cellular material + + + align:start position:0% +conductivity of a cellular material +depends in part on the cell size and the + + align:start position:0% +depends in part on the cell size and the + + + align:start position:0% +depends in part on the cell size and the +cell size for foam Plastics is in here + + align:start position:0% +cell size for foam Plastics is in here + + + align:start position:0% +cell size for foam Plastics is in here +and that for cork is down here and + + align:start position:0% +and that for cork is down here and + + + align:start position:0% +and that for cork is down here and +because it has a smaller cell size it + + align:start position:0% +because it has a smaller cell size it + + + align:start position:0% +because it has a smaller cell size it +has a lower thermal conductivity so cork + + align:start position:0% +has a lower thermal conductivity so cork + + + align:start position:0% +has a lower thermal conductivity so cork +was at one point used um to some extent + + align:start position:0% +was at one point used um to some extent + + + align:start position:0% +was at one point used um to some extent +for thermal instulation so if you go to + + align:start position:0% +for thermal instulation so if you go to + + + align:start position:0% +for thermal instulation so if you go to +Portugal where cork comes from there's + + align:start position:0% +Portugal where cork comes from there's + + + align:start position:0% +Portugal where cork comes from there's +hermit caves so there were these old + + align:start position:0% +hermit caves so there were these old + + + align:start position:0% +hermit caves so there were these old +kind of you know hermit kind of + + align:start position:0% +kind of you know hermit kind of + + + align:start position:0% +kind of you know hermit kind of +religious people who would kind of hole + + align:start position:0% +religious people who would kind of hole + + + align:start position:0% +religious people who would kind of hole +up in a cave and they would line the + + align:start position:0% +up in a cave and they would line the + + + align:start position:0% +up in a cave and they would line the +caves with cork to try to make it a + + align:start position:0% +caves with cork to try to make it a + + + align:start position:0% +caves with cork to try to make it a +little more insulated a little more kind + + align:start position:0% +little more insulated a little more kind + + + align:start position:0% +little more insulated a little more kind +of warm the other place you see this is + + align:start position:0% +of warm the other place you see this is + + + align:start position:0% +of warm the other place you see this is +um if you look at cigarettes you know + + align:start position:0% +um if you look at cigarettes you know + + + align:start position:0% +um if you look at cigarettes you know +how cigarettes have that little brown + + align:start position:0% +how cigarettes have that little brown + + + align:start position:0% +how cigarettes have that little brown +tip on the part that touches your lips + + align:start position:0% +tip on the part that touches your lips + + + align:start position:0% +tip on the part that touches your lips +that's meant to look like Cork and if + + align:start position:0% +that's meant to look like Cork and if + + + align:start position:0% +that's meant to look like Cork and if +you look it has little dots on it and + + align:start position:0% +you look it has little dots on it and + + + align:start position:0% +you look it has little dots on it and +the little dots so the little lenticles + + align:start position:0% +the little dots so the little lenticles + + + align:start position:0% +the little dots so the little lenticles +and apparently they used cork originally + + align:start position:0% +and apparently they used cork originally + + + align:start position:0% +and apparently they used cork originally +in cigarettes as a sort of thermal + + align:start position:0% +in cigarettes as a sort of thermal + + + align:start position:0% +in cigarettes as a sort of thermal +insulation between the cigarette and + + align:start position:0% +insulation between the cigarette and + + + align:start position:0% +insulation between the cigarette and +your mouth so it was used for that too + + align:start position:0% +your mouth so it was used for that too + + + align:start position:0% +your mouth so it was used for that too +um and then one final thing cork is also + + align:start position:0% +um and then one final thing cork is also + + + align:start position:0% +um and then one final thing cork is also +used obviously for for bulletin boards + + align:start position:0% +used obviously for for bulletin boards + + + align:start position:0% +used obviously for for bulletin boards +and if you push a a sort of pin into + + align:start position:0% +and if you push a a sort of pin into + + + align:start position:0% +and if you push a a sort of pin into +cork then you get this local deformation + + align:start position:0% +cork then you get this local deformation + + + align:start position:0% +cork then you get this local deformation +here so here's our pin and here's kind + + align:start position:0% +here so here's our pin and here's kind + + + align:start position:0% +here so here's our pin and here's kind +of cells locally deformed and when you + + align:start position:0% +of cells locally deformed and when you + + + align:start position:0% +of cells locally deformed and when you +pull the pin out you'll recover some of + + align:start position:0% +pull the pin out you'll recover some of + + + align:start position:0% +pull the pin out you'll recover some of +that deformation because the deoration + + align:start position:0% +that deformation because the deoration + + + align:start position:0% +that deformation because the deoration +is elastic so the hole will partly close + + align:start position:0% +is elastic so the hole will partly close + + + align:start position:0% +is elastic so the hole will partly close +so that's my little Spiel on Cork and + + align:start position:0% +so that's my little Spiel on Cork and + + + align:start position:0% +so that's my little Spiel on Cork and +that's just CU it's kind of interesting + + align:start position:0% +that's just CU it's kind of interesting + + + align:start position:0% +that's just CU it's kind of interesting +it's not you know there's no test on + + align:start position:0% +it's not you know there's no test on + + + align:start position:0% +it's not you know there's no test on +cork or anything like that okay so are + + align:start position:0% +cork or anything like that okay so are + + + align:start position:0% +cork or anything like that okay so are +we good with cork any questions we're + + align:start position:0% +we good with cork any questions we're + + + align:start position:0% +we good with cork any questions we're +okay okay so let me scoot out of there + + align:start position:0% +okay okay so let me scoot out of there + + + align:start position:0% +okay okay so let me scoot out of there +and then the next part of the course I + + align:start position:0% +and then the next part of the course I + + + align:start position:0% +and then the next part of the course I +wanted to talk about + + align:start position:0% + + + + align:start position:0% + +Foams so let me just park the cork thing + + align:start position:0% +Foams so let me just park the cork thing + + + align:start position:0% +Foams so let me just park the cork thing +oh let me pass these corks around so you + + align:start position:0% +oh let me pass these corks around so you + + + align:start position:0% +oh let me pass these corks around so you +can play with those + + align:start position:0% +can play with those + + + align:start position:0% +can play with those +too oops here's little bits of cork + + align:start position:0% +too oops here's little bits of cork + + + align:start position:0% +too oops here's little bits of cork +there you go there's the champagne cork + + align:start position:0% +there you go there's the champagne cork + + + align:start position:0% +there you go there's the champagne cork +the rubber cork some little cork + + align:start position:0% + + + + align:start position:0% + +layers okay so the next part of the + + align:start position:0% +layers okay so the next part of the + + + align:start position:0% +layers okay so the next part of the +course I wanted to talk about Foams and + + align:start position:0% +course I wanted to talk about Foams and + + + align:start position:0% +course I wanted to talk about Foams and +I want to talk about how we model the + + align:start position:0% +I want to talk about how we model the + + + align:start position:0% +I want to talk about how we model the +mechanical behavior of Foams so if we + + align:start position:0% +mechanical behavior of Foams so if we + + + align:start position:0% +mechanical behavior of Foams so if we +look at the stress strain curve for + + align:start position:0% +look at the stress strain curve for + + + align:start position:0% +look at the stress strain curve for +Foams these are some examples for Foams + + align:start position:0% +Foams these are some examples for Foams + + + align:start position:0% +Foams these are some examples for Foams +made out of different materials with + + align:start position:0% +made out of different materials with + + + align:start position:0% +made out of different materials with +different characteristics so the + + align:start position:0% +different characteristics so the + + + align:start position:0% +different characteristics so the +polyurethane and the polyethylene here + + align:start position:0% +polyurethane and the polyethylene here + + + align:start position:0% +polyurethane and the polyethylene here +are examples of um elastomeric Foams + + align:start position:0% +are examples of um elastomeric Foams + + + align:start position:0% +are examples of um elastomeric Foams +really uh this one here is an open cell + + align:start position:0% +really uh this one here is an open cell + + + align:start position:0% +really uh this one here is an open cell +foam this one's a closed cell foam + + align:start position:0% +foam this one's a closed cell foam + + + align:start position:0% +foam this one's a closed cell foam +polymac liid is a a polymer that has a + + align:start position:0% +polymac liid is a a polymer that has a + + + align:start position:0% +polymac liid is a a polymer that has a +yield point and mullite is a ceramic and + + align:start position:0% +yield point and mullite is a ceramic and + + + align:start position:0% +yield point and mullite is a ceramic and +so you can see the shapes of these + + align:start position:0% +so you can see the shapes of these + + + align:start position:0% +so you can see the shapes of these +curves resemble the shapes that we saw + + align:start position:0% +curves resemble the shapes that we saw + + + align:start position:0% +curves resemble the shapes that we saw +for the Honeycombs right they look + + align:start position:0% +for the Honeycombs right they look + + + align:start position:0% +for the Honeycombs right they look +exactly the same in fact and the + + align:start position:0% +exactly the same in fact and the + + + align:start position:0% +exactly the same in fact and the +mechanisms of deformation in the Foams + + align:start position:0% +mechanisms of deformation in the Foams + + + align:start position:0% +mechanisms of deformation in the Foams +are very similar to the Honeycombs and + + align:start position:0% +are very similar to the Honeycombs and + + + align:start position:0% +are very similar to the Honeycombs and +even though the Foams have a much more + + align:start position:0% +even though the Foams have a much more + + + align:start position:0% +even though the Foams have a much more +complicated geometry we can use some of + + align:start position:0% +complicated geometry we can use some of + + + align:start position:0% +complicated geometry we can use some of +the ideas from the Honeycombs to + + align:start position:0% +the ideas from the Honeycombs to + + + align:start position:0% +the ideas from the Honeycombs to +understand how the Foams behave so that + + align:start position:0% +understand how the Foams behave so that + + + align:start position:0% +understand how the Foams behave so that +was part of the reason for doing the the + + align:start position:0% +was part of the reason for doing the the + + + align:start position:0% +was part of the reason for doing the the +honeycomb analysis so uh so oops let me + + align:start position:0% +honeycomb analysis so uh so oops let me + + + align:start position:0% +honeycomb analysis so uh so oops let me +back up so the these curves here are all + + align:start position:0% +back up so the these curves here are all + + + align:start position:0% +back up so the these curves here are all +in compression these curves here are all + + align:start position:0% +in compression these curves here are all + + + align:start position:0% +in compression these curves here are all +in tension so again these ones in + + align:start position:0% +in tension so again these ones in + + + align:start position:0% +in tension so again these ones in +tension also look like the curves for + + align:start position:0% +tension also look like the curves for + + + align:start position:0% +tension also look like the curves for +the Honeycombs remember in tension we + + align:start position:0% +the Honeycombs remember in tension we + + + align:start position:0% +the Honeycombs remember in tension we +don't get any elastic buckling so if the + + align:start position:0% +don't get any elastic buckling so if the + + + align:start position:0% +don't get any elastic buckling so if the +foam is made of an elastomer we we don't + + align:start position:0% +foam is made of an elastomer we we don't + + + align:start position:0% +foam is made of an elastomer we we don't +see any stress Plateau if the foam is + + align:start position:0% +see any stress Plateau if the foam is + + + align:start position:0% +see any stress Plateau if the foam is +made of a material with a yield stress + + align:start position:0% +made of a material with a yield stress + + + align:start position:0% +made of a material with a yield stress +then uh we get a very short yield + + align:start position:0% +then uh we get a very short yield + + + align:start position:0% +then uh we get a very short yield +Plateau because of a slight geometrical + + align:start position:0% +Plateau because of a slight geometrical + + + align:start position:0% +Plateau because of a slight geometrical +difference between pulling and + + align:start position:0% +difference between pulling and + + + align:start position:0% +difference between pulling and +compressing the foam and if it's a + + align:start position:0% +compressing the foam and if it's a + + + align:start position:0% +compressing the foam and if it's a +brittle material then we just get + + align:start position:0% +brittle material then we just get + + + align:start position:0% +brittle material then we just get +fractured it's going to be some fracture + + align:start position:0% +fractured it's going to be some fracture + + + align:start position:0% +fractured it's going to be some fracture +toughness that's going to characterize + + align:start position:0% +toughness that's going to characterize + + + align:start position:0% +toughness that's going to characterize +it so we can look at um the deoration + + align:start position:0% +it so we can look at um the deoration + + + align:start position:0% +it so we can look at um the deoration +and the failure in these Foams and look + + align:start position:0% +and the failure in these Foams and look + + + align:start position:0% +and the failure in these Foams and look +at the mechanisms and what we're going + + align:start position:0% +at the mechanisms and what we're going + + + align:start position:0% +at the mechanisms and what we're going +to do is model the mechanisms and not + + align:start position:0% +to do is model the mechanisms and not + + + align:start position:0% +to do is model the mechanisms and not +worry too much about the cell geometry + + align:start position:0% +worry too much about the cell geometry + + + align:start position:0% +worry too much about the cell geometry +so we're going to use dimensional + + align:start position:0% +so we're going to use dimensional + + + align:start position:0% +so we're going to use dimensional +arguments here so here's a foam in + + align:start position:0% +arguments here so here's a foam in + + + align:start position:0% +arguments here so here's a foam in +compression it was compressed from the + + align:start position:0% +compression it was compressed from the + + + align:start position:0% +compression it was compressed from the +top to the bottom and you can see this U + + align:start position:0% +top to the bottom and you can see this U + + + align:start position:0% +top to the bottom and you can see this U +strut that's circled in red this is + + align:start position:0% +strut that's circled in red this is + + + align:start position:0% +strut that's circled in red this is +unloaded and then this is after some + + align:start position:0% +unloaded and then this is after some + + + align:start position:0% +unloaded and then this is after some +load and you can see this is bent + + align:start position:0% +load and you can see this is bent + + + align:start position:0% +load and you can see this is bent +somewhat and then you can see this + + align:start position:0% +somewhat and then you can see this + + + align:start position:0% +somewhat and then you can see this +vertical strut here as the load gets + + align:start position:0% +vertical strut here as the load gets + + + align:start position:0% +vertical strut here as the load gets +larger you can see that struts buckled + + align:start position:0% +larger you can see that struts buckled + + + align:start position:0% +larger you can see that struts buckled +so you get in an elastomeric foam you + + align:start position:0% +so you get in an elastomeric foam you + + + align:start position:0% +so you get in an elastomeric foam you +get bending and buckling just the same + + align:start position:0% +get bending and buckling just the same + + + align:start position:0% +get bending and buckling just the same +as we did in the + + align:start position:0% +as we did in the + + + align:start position:0% +as we did in the +honeycomb um and then here's a metal + + align:start position:0% +honeycomb um and then here's a metal + + + align:start position:0% +honeycomb um and then here's a metal +foam uh and you form plastic hinges in + + align:start position:0% +foam uh and you form plastic hinges in + + + align:start position:0% +foam uh and you form plastic hinges in +the metal foam so here's a a cell wall + + align:start position:0% +the metal foam so here's a a cell wall + + + align:start position:0% +the metal foam so here's a a cell wall +here and it's a little bent to start + + align:start position:0% +here and it's a little bent to start + + + align:start position:0% +here and it's a little bent to start +with at zero load but you can see it + + align:start position:0% +with at zero load but you can see it + + + align:start position:0% +with at zero load but you can see it +becomes more bent in this image over + + align:start position:0% +becomes more bent in this image over + + + align:start position:0% +becomes more bent in this image over +here and here's a cell wall that's more + + align:start position:0% +here and here's a cell wall that's more + + + align:start position:0% +here and here's a cell wall that's more +or less vertical and you can see that + + align:start position:0% +or less vertical and you can see that + + + align:start position:0% +or less vertical and you can see that +wall buckles it's a plastic buckling in + + align:start position:0% +wall buckles it's a plastic buckling in + + + align:start position:0% +wall buckles it's a plastic buckling in +this case there's a permanent + + align:start position:0% +this case there's a permanent + + + align:start position:0% +this case there's a permanent +deformation + + align:start position:0% +deformation + + + align:start position:0% +deformation +there and here's a a brittle foam and + + align:start position:0% +there and here's a a brittle foam and + + + align:start position:0% +there and here's a a brittle foam and +you can see cell walls in this foam + + align:start position:0% +you can see cell walls in this foam + + + align:start position:0% +you can see cell walls in this foam +fracture so this region here is + + align:start position:0% +fracture so this region here is + + + align:start position:0% +fracture so this region here is +equivalent to this region here that + + align:start position:0% +equivalent to this region here that + + + align:start position:0% +equivalent to this region here that +little glitch there is the same as that + + align:start position:0% +little glitch there is the same as that + + + align:start position:0% +little glitch there is the same as that +little glitch there and you can see + + align:start position:0% +little glitch there and you can see + + + align:start position:0% +little glitch there and you can see +there's a couple of cell walls here that + + align:start position:0% +there's a couple of cell walls here that + + + align:start position:0% +there's a couple of cell walls here that +are fractured and so we get fractured so + + align:start position:0% +are fractured and so we get fractured so + + + align:start position:0% +are fractured and so we get fractured so +the idea is is that the mechanisms of + + align:start position:0% +the idea is is that the mechanisms of + + + align:start position:0% +the idea is is that the mechanisms of +deformation in the Foams par those in + + align:start position:0% +deformation in the Foams par those in + + + align:start position:0% +deformation in the Foams par those in +the Honeycombs + + align:start position:0% +the Honeycombs + + + align:start position:0% +the Honeycombs +okay all right so let me write some of + + align:start position:0% +okay all right so let me write some of + + + align:start position:0% +okay all right so let me write some of +this stuff on the + + align:start position:0% +this stuff on the + + + align:start position:0% +this stuff on the +board and we're going to start off by + + align:start position:0% +board and we're going to start off by + + + align:start position:0% +board and we're going to start off by +talking about open cell Foams so Foams + + align:start position:0% +talking about open cell Foams so Foams + + + align:start position:0% +talking about open cell Foams so Foams +where there's just solid in the edges + + align:start position:0% +where there's just solid in the edges + + + align:start position:0% +where there's just solid in the edges +but not in the faces of the polyhedral + + align:start position:0% +but not in the faces of the polyhedral + + + align:start position:0% +but not in the faces of the polyhedral +cells and then we'll talk about closed + + align:start position:0% +cells and then we'll talk about closed + + + align:start position:0% +cells and then we'll talk about closed +cell Foams where there solid in the + + align:start position:0% +cell Foams where there solid in the + + + align:start position:0% +cell Foams where there solid in the +faces as well but the open cell ones are + + align:start position:0% +faces as well but the open cell ones are + + + align:start position:0% +faces as well but the open cell ones are +easier so we we'll start with + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +so in compression we see the same three + + align:start position:0% +so in compression we see the same three + + + align:start position:0% +so in compression we see the same three +regimes as we did before for the + + align:start position:0% + + + + align:start position:0% + +Honeycombs so that's a linear elastic + + align:start position:0% +Honeycombs so that's a linear elastic + + + align:start position:0% +Honeycombs so that's a linear elastic +regime that corresponds to bending of + + align:start position:0% +regime that corresponds to bending of + + + align:start position:0% +regime that corresponds to bending of +the cell + + align:start position:0% +the cell + + + align:start position:0% +the cell +walls + + align:start position:0% + + + + align:start position:0% + +there's a stress + + align:start position:0% + + + + align:start position:0% + +plateau and for elastomeric Foams that + + align:start position:0% +plateau and for elastomeric Foams that + + + align:start position:0% +plateau and for elastomeric Foams that +corresponds to + + align:start position:0% + + + + align:start position:0% + +buckling for metal Foams it corresponds + + align:start position:0% +buckling for metal Foams it corresponds + + + align:start position:0% +buckling for metal Foams it corresponds +to the formation of plastic + + align:start position:0% + + + + align:start position:0% + +hinges and then for ceramic or brittle + + align:start position:0% +hinges and then for ceramic or brittle + + + align:start position:0% +hinges and then for ceramic or brittle +foams + + align:start position:0% + + + + align:start position:0% + +it corresponds to brittle crushing so + + align:start position:0% +it corresponds to brittle crushing so + + + align:start position:0% +it corresponds to brittle crushing so +fracturing of the cell + + align:start position:0% + + + + align:start position:0% + +walls and then if you load the foam up + + align:start position:0% +walls and then if you load the foam up + + + align:start position:0% +walls and then if you load the foam up +to higher strains and higher stresses + + align:start position:0% +to higher strains and higher stresses + + + align:start position:0% +to higher strains and higher stresses +eventually you get to + + align:start position:0% + + + + align:start position:0% + +densification and in + + align:start position:0% +densification and in + + + align:start position:0% +densification and in +tension just like the Honeycombs for the + + align:start position:0% +tension just like the Honeycombs for the + + + align:start position:0% +tension just like the Honeycombs for the +elastomeric materials we there is no + + align:start position:0% + + + + align:start position:0% + +buckling uh we can get a stress Plateau + + align:start position:0% + + + + align:start position:0% + +from from plastic + + align:start position:0% +from from plastic + + + align:start position:0% +from from plastic +hinges if there's say a metal + + align:start position:0% +hinges if there's say a metal + + + align:start position:0% +hinges if there's say a metal +foam and for a brittle + + align:start position:0% + + + + align:start position:0% + +foam uh we would get a fracture + + align:start position:0% +foam uh we would get a fracture + + + align:start position:0% +foam uh we would get a fracture +toughness and brittle fracture + + align:start position:0% + + + + align:start position:0% + +intention so the idea is the mechanisms + + align:start position:0% +intention so the idea is the mechanisms + + + align:start position:0% +intention so the idea is the mechanisms +of deformation and failure just parallel + + align:start position:0% +of deformation and failure just parallel + + + align:start position:0% +of deformation and failure just parallel +what we've seen in the + + align:start position:0% +what we've seen in the + + + align:start position:0% +what we've seen in the +Honeycombs so we'll start off with the + + align:start position:0% +Honeycombs so we'll start off with the + + + align:start position:0% +Honeycombs so we'll start off with the +linear elastic + + align:start position:0% + + + + align:start position:0% + +behavior and we'll start with cell + + align:start position:0% + + + + align:start position:0% + +phams so the initial linear elasticity + + align:start position:0% +phams so the initial linear elasticity + + + align:start position:0% +phams so the initial linear elasticity +due to bending of the cell + + align:start position:0% + + + + align:start position:0% + +walls and if the thickness of the cell + + align:start position:0% +walls and if the thickness of the cell + + + align:start position:0% +walls and if the thickness of the cell +Edge is relative to the length is small + + align:start position:0% +Edge is relative to the length is small + + + align:start position:0% +Edge is relative to the length is small +the bending dominates the uh deformation + + align:start position:0% +the bending dominates the uh deformation + + + align:start position:0% +the bending dominates the uh deformation +but as the thickness to length ratio + + align:start position:0% +but as the thickness to length ratio + + + align:start position:0% +but as the thickness to length ratio +increases then axial deformations can + + align:start position:0% +increases then axial deformations can + + + align:start position:0% +increases then axial deformations can +become important + + align:start position:0% + + + + align:start position:0% + +too + + align:start position:0% + + + + align:start position:0% + +and what we're going to do is we're + + align:start position:0% +and what we're going to do is we're + + + align:start position:0% +and what we're going to do is we're +going to consider dimensional + + align:start position:0% + + + + align:start position:0% + +arguments and we're going to set the + + align:start position:0% +arguments and we're going to set the + + + align:start position:0% +arguments and we're going to set the +dimensional arguments up so that we + + align:start position:0% +dimensional arguments up so that we + + + align:start position:0% +dimensional arguments up so that we +replicate the mechanisms of deoration + + align:start position:0% +replicate the mechanisms of deoration + + + align:start position:0% +replicate the mechanisms of deoration +and failure but we don't worry too much + + align:start position:0% +and failure but we don't worry too much + + + align:start position:0% +and failure but we don't worry too much +about the cell + + align:start position:0% + + + + align:start position:0% + +geometry + + align:start position:0% + + + + align:start position:0% + +so what I'm going to start with is + + align:start position:0% +so what I'm going to start with is + + + align:start position:0% +so what I'm going to start with is +considering a cubic + + align:start position:0% + + + + align:start position:0% + +cell and I've arranged the cubic cell so + + align:start position:0% +cell and I've arranged the cubic cell so + + + align:start position:0% +cell and I've arranged the cubic cell so +that the um the cell edges are staggered + + align:start position:0% +that the um the cell edges are staggered + + + align:start position:0% +that the um the cell edges are staggered +and that's going to give me the + + align:start position:0% + + + + align:start position:0% + +bending and the edge length is going to + + align:start position:0% +bending and the edge length is going to + + + align:start position:0% +bending and the edge length is going to +be + + align:start position:0% + + + + align:start position:0% + +L and the I'm going to say we have a + + align:start position:0% +L and the I'm going to say we have a + + + align:start position:0% +L and the I'm going to say we have a +square + + align:start position:0% +square + + + align:start position:0% +square +cross-section + + align:start position:0% +cross-section + + + align:start position:0% +cross-section +t^2 + + align:start position:0% + + + + align:start position:0% + +okay so so here's our kind of idealized + + align:start position:0% +okay so so here's our kind of idealized + + + align:start position:0% +okay so so here's our kind of idealized +model here with the cubic + + align:start position:0% +model here with the cubic + + + align:start position:0% +model here with the cubic +cell so all the members have a length L + + align:start position:0% +cell so all the members have a length L + + + align:start position:0% +cell so all the members have a length L +all of them have a square cross-section + + align:start position:0% +all of them have a square cross-section + + + align:start position:0% +all of them have a square cross-section +t^2 and that's an open cell model we've + + align:start position:0% +t^2 and that's an open cell model we've + + + align:start position:0% +t^2 and that's an open cell model we've +got just solid on the edges and nothing + + align:start position:0% +got just solid on the edges and nothing + + + align:start position:0% +got just solid on the edges and nothing +on the faces and the idea is that if I + + align:start position:0% +on the faces and the idea is that if I + + + align:start position:0% +on the faces and the idea is that if I +bend that or if I load that in + + align:start position:0% +bend that or if I load that in + + + align:start position:0% +bend that or if I load that in +compression so I apply say a stress out + + align:start position:0% +compression so I apply say a stress out + + + align:start position:0% +compression so I apply say a stress out +here that puts forces on those members + + align:start position:0% +here that puts forces on those members + + + align:start position:0% +here that puts forces on those members +there because I've staggered these cell + + align:start position:0% +there because I've staggered these cell + + + align:start position:0% +there because I've staggered these cell +walls with with these ones here we're + + align:start position:0% +walls with with these ones here we're + + + align:start position:0% +walls with with these ones here we're +going to get bending in this cell edge + + align:start position:0% +going to get bending in this cell edge + + + align:start position:0% +going to get bending in this cell edge +here and that bending is going to be + + align:start position:0% +here and that bending is going to be + + + align:start position:0% +here and that bending is going to be +what we + + align:start position:0% + + + + align:start position:0% + +model + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so I'm going to set this up so that one + + align:start position:0% +so I'm going to set this up so that one + + + align:start position:0% +so I'm going to set this up so that one +thing is proportional to something else + + align:start position:0% +thing is proportional to something else + + + align:start position:0% +thing is proportional to something else +and these relationships are going to be + + align:start position:0% +and these relationships are going to be + + + align:start position:0% +and these relationships are going to be +true regardless of the cell geometry so + + align:start position:0% +true regardless of the cell geometry so + + + align:start position:0% +true regardless of the cell geometry so +I could have picked a Tetra decahedra if + + align:start position:0% +I could have picked a Tetra decahedra if + + + align:start position:0% +I could have picked a Tetra decahedra if +I wanted to and I would had these same + + align:start position:0% +I wanted to and I would had these same + + + align:start position:0% +I wanted to and I would had these same +relationships and I'm just picking a + + align:start position:0% +relationships and I'm just picking a + + + align:start position:0% +relationships and I'm just picking a +cubic thing because it's easier to think + + align:start position:0% +cubic thing because it's easier to think + + + align:start position:0% +cubic thing because it's easier to think +about um so first of all we look at the + + align:start position:0% +about um so first of all we look at the + + + align:start position:0% +about um so first of all we look at the +relative density and remember the + + align:start position:0% +relative density and remember the + + + align:start position:0% +relative density and remember the +relative density is the volume fraction + + align:start position:0% +relative density is the volume fraction + + + align:start position:0% +relative density is the volume fraction +of + + align:start position:0% +of + + + align:start position:0% +of +solid so it's the volume of the solid + + align:start position:0% +solid so it's the volume of the solid + + + align:start position:0% +solid so it's the volume of the solid +over the total volume and that's going + + align:start position:0% +over the total volume and that's going + + + align:start position:0% +over the total volume and that's going +to go as t^2 + + align:start position:0% +to go as t^2 + + + align:start position:0% +to go as t^2 +L over L cubed or just T over L all + + align:start position:0% +L over L cubed or just T over L all + + + align:start position:0% +L over L cubed or just T over L all +squared okay so remember for the + + align:start position:0% +squared okay so remember for the + + + align:start position:0% +squared okay so remember for the +honeycomb the relative density went + + align:start position:0% +honeycomb the relative density went + + + align:start position:0% +honeycomb the relative density went +linearly with t l for the open cell foam + + align:start position:0% +linearly with t l for the open cell foam + + + align:start position:0% +linearly with t l for the open cell foam +it goes as T L + + align:start position:0% + + + + align:start position:0% + +squared the moment of inertia in this + + align:start position:0% +squared the moment of inertia in this + + + align:start position:0% +squared the moment of inertia in this +case is going to go as t to the 4th + + align:start position:0% +case is going to go as t to the 4th + + + align:start position:0% +case is going to go as t to the 4th +remember we have a square section t^2 so + + align:start position:0% +remember we have a square section t^2 so + + + align:start position:0% +remember we have a square section t^2 so +if it's BH cubed over 12 B is t h is T + + align:start position:0% +if it's BH cubed over 12 B is t h is T + + + align:start position:0% +if it's BH cubed over 12 B is t h is T +it's going as T + + align:start position:0% +it's going as T + + + align:start position:0% +it's going as T +4th and then what I'm going to say is + + align:start position:0% +4th and then what I'm going to say is + + + align:start position:0% +4th and then what I'm going to say is +the stress is going to go as f over an + + align:start position:0% +the stress is going to go as f over an + + + align:start position:0% +the stress is going to go as f over an +area length squared okay so if I look at + + align:start position:0% +area length squared okay so if I look at + + + align:start position:0% +area length squared okay so if I look at +my little square thing here or I look at + + align:start position:0% +my little square thing here or I look at + + + align:start position:0% +my little square thing here or I look at +having my Force here here we have a + + align:start position:0% +having my Force here here we have a + + + align:start position:0% +having my Force here here we have a +force F and it's acting over an area + + align:start position:0% +force F and it's acting over an area + + + align:start position:0% +force F and it's acting over an area +that's somehow related to l s right so I + + align:start position:0% +that's somehow related to l s right so I + + + align:start position:0% +that's somehow related to l s right so I +don't know exactly what that constant is + + align:start position:0% +don't know exactly what that constant is + + + align:start position:0% +don't know exactly what that constant is +and I'm just going to not try to + + align:start position:0% +and I'm just going to not try to + + + align:start position:0% +and I'm just going to not try to +calculate that but it goes as F l^2 + + align:start position:0% +calculate that but it goes as F l^2 + + + align:start position:0% +calculate that but it goes as F l^2 +similarly I can write that the strain is + + align:start position:0% +similarly I can write that the strain is + + + align:start position:0% +similarly I can write that the strain is +going to go as Delta over l so the + + align:start position:0% +going to go as Delta over l so the + + + align:start position:0% +going to go as Delta over l so the +strain is going to go as this bending + + align:start position:0% +strain is going to go as this bending + + + align:start position:0% +strain is going to go as this bending +deflection here that Delta divided by + + align:start position:0% +deflection here that Delta divided by + + + align:start position:0% +deflection here that Delta divided by +the height of the cell and that's also + + align:start position:0% +the height of the cell and that's also + + + align:start position:0% +the height of the cell and that's also +L and then I also know from just + + align:start position:0% +L and then I also know from just + + + align:start position:0% +L and then I also know from just +structural mechanics that Delta is going + + align:start position:0% +structural mechanics that Delta is going + + + align:start position:0% +structural mechanics that Delta is going +to go as f l cubed over e of the solid + + align:start position:0% +to go as f l cubed over e of the solid + + + align:start position:0% +to go as f l cubed over e of the solid +and I + + align:start position:0% + + + + align:start position:0% + +okay and then I'm just going to put all + + align:start position:0% +okay and then I'm just going to put all + + + align:start position:0% +okay and then I'm just going to put all +these things together to get the modulus + + align:start position:0% +these things together to get the modulus + + + align:start position:0% +these things together to get the modulus +so the modulus of the foam is going to + + align:start position:0% +so the modulus of the foam is going to + + + align:start position:0% +so the modulus of the foam is going to +go as the stress over the + + align:start position:0% +go as the stress over the + + + align:start position:0% +go as the stress over the +strain so if I plug in what I have for + + align:start position:0% +strain so if I plug in what I have for + + + align:start position:0% +strain so if I plug in what I have for +the stress it's f l^ 2 if I plug in what + + align:start position:0% +the stress it's f l^ 2 if I plug in what + + + align:start position:0% +the stress it's f l^ 2 if I plug in what +I have for the strain it's Delta over + + align:start position:0% + + + + align:start position:0% + +l so this is f over L and Delta and I'm + + align:start position:0% +l so this is f over L and Delta and I'm + + + align:start position:0% +l so this is f over L and Delta and I'm +going to replace Delta by FL cubed over + + align:start position:0% +going to replace Delta by FL cubed over + + + align:start position:0% +going to replace Delta by FL cubed over +es s and I'm going to use instead of I + + align:start position:0% +es s and I'm going to use instead of I + + + align:start position:0% +es s and I'm going to use instead of I +I'm going to use T + + align:start position:0% +I'm going to use T + + + align:start position:0% +I'm going to use T +4th so then the fs are going to cancel + + align:start position:0% + + + + align:start position:0% + +out and I've got + + align:start position:0% +out and I've got + + + align:start position:0% +out and I've got +that the modulus goes as the modulus of + + align:start position:0% +that the modulus goes as the modulus of + + + align:start position:0% +that the modulus goes as the modulus of +the solid time t l to 4th power and then + + align:start position:0% +the solid time t l to 4th power and then + + + align:start position:0% +the solid time t l to 4th power and then +I can put that in terms of the relative + + align:start position:0% + + + + align:start position:0% + +density it's going to go as the relative + + align:start position:0% +density it's going to go as the relative + + + align:start position:0% +density it's going to go as the relative +density + + align:start position:0% +density + + + align:start position:0% +density +squared so I can summarize all of this + + align:start position:0% +squared so I can summarize all of this + + + align:start position:0% +squared so I can summarize all of this +by saying that the Young's modulus of + + align:start position:0% +by saying that the Young's modulus of + + + align:start position:0% +by saying that the Young's modulus of +the foam is some constant C1 I'm going + + align:start position:0% +the foam is some constant C1 I'm going + + + align:start position:0% +the foam is some constant C1 I'm going +to call it times the modulus of the + + align:start position:0% +to call it times the modulus of the + + + align:start position:0% +to call it times the modulus of the +solid time the relative density + + align:start position:0% + + + + align:start position:0% + +squared okay so this has the same kind + + align:start position:0% +squared okay so this has the same kind + + + align:start position:0% +squared okay so this has the same kind +of form as those equations we had for + + align:start position:0% +of form as those equations we had for + + + align:start position:0% +of form as those equations we had for +the honey Co right there's a solid cell + + align:start position:0% +the honey Co right there's a solid cell + + + align:start position:0% +the honey Co right there's a solid cell +wall property the solid modulus here for + + align:start position:0% +wall property the solid modulus here for + + + align:start position:0% +wall property the solid modulus here for +the Honeycombs I put it in terms of T + + align:start position:0% +the Honeycombs I put it in terms of T + + + align:start position:0% +the Honeycombs I put it in terms of T +over L but the TL was related to the + + align:start position:0% +over L but the TL was related to the + + + align:start position:0% +over L but the TL was related to the +relative density so there's a how much + + align:start position:0% +relative density so there's a how much + + + align:start position:0% +relative density so there's a how much +solid you've got is reflected in the + + align:start position:0% +solid you've got is reflected in the + + + align:start position:0% +solid you've got is reflected in the +relative + + align:start position:0% +relative + + + align:start position:0% +relative +density and then this constant C1 wraps + + align:start position:0% +density and then this constant C1 wraps + + + align:start position:0% +density and then this constant C1 wraps +up all the geometrical constants that + + align:start position:0% +up all the geometrical constants that + + + align:start position:0% +up all the geometrical constants that +I've said you know one thing's + + align:start position:0% +I've said you know one thing's + + + align:start position:0% +I've said you know one thing's +proportional to another and something + + align:start position:0% +proportional to another and something + + + align:start position:0% +proportional to another and something +else is proportional to another C1 just + + align:start position:0% +else is proportional to another C1 just + + + align:start position:0% +else is proportional to another C1 just +wraps up all of those okay so I'm just + + align:start position:0% +wraps up all of those okay so I'm just + + + align:start position:0% +wraps up all of those okay so I'm just +going to say here C1 includes all the + + align:start position:0% +going to say here C1 includes all the + + + align:start position:0% +going to say here C1 includes all the +geometrical + + align:start position:0% + + + + align:start position:0% + +constants and we have to get C1 by + + align:start position:0% +constants and we have to get C1 by + + + align:start position:0% +constants and we have to get C1 by +looking at + + align:start position:0% +looking at + + + align:start position:0% +looking at +data and if we look at data for the + + align:start position:0% +data and if we look at data for the + + + align:start position:0% +data and if we look at data for the +young modulus we find that + + align:start position:0% +young modulus we find that + + + align:start position:0% +young modulus we find that +C1 is just about equal to + + align:start position:0% + + + + align:start position:0% + +one and people have also done sort of + + align:start position:0% +one and people have also done sort of + + + align:start position:0% +one and people have also done sort of +more sophisticated analyses than this so + + align:start position:0% +more sophisticated analyses than this so + + + align:start position:0% +more sophisticated analyses than this so +there's a group of people who looked at + + align:start position:0% +there's a group of people who looked at + + + align:start position:0% +there's a group of people who looked at +doing a full scale structural analysis + + align:start position:0% +doing a full scale structural analysis + + + align:start position:0% +doing a full scale structural analysis +of an open cell Tetra decahedral cell + + align:start position:0% +of an open cell Tetra decahedral cell + + + align:start position:0% +of an open cell Tetra decahedral cell +and remember I said they packed to fill + + align:start position:0% +and remember I said they packed to fill + + + align:start position:0% +and remember I said they packed to fill +space so you can look at a unit cell and + + align:start position:0% +space so you can look at a unit cell and + + + align:start position:0% +space so you can look at a unit cell and +they also made their cells such that the + + align:start position:0% +they also made their cells such that the + + + align:start position:0% +they also made their cells such that the +thickness along the length of the cell + + align:start position:0% +thickness along the length of the cell + + + align:start position:0% +thickness along the length of the cell +was not constant the thickness varied as + + align:start position:0% +was not constant the thickness varied as + + + align:start position:0% +was not constant the thickness varied as +something called a plateau border so if + + align:start position:0% +something called a plateau border so if + + + align:start position:0% +something called a plateau border so if +you have a foam that's made by surface + + align:start position:0% +you have a foam that's made by surface + + + align:start position:0% +you have a foam that's made by surface +tension the edges will tend to have + + align:start position:0% +tension the edges will tend to have + + + align:start position:0% +tension the edges will tend to have +these Plateau borders and the thickness + + align:start position:0% +these Plateau borders and the thickness + + + align:start position:0% +these Plateau borders and the thickness +will vary along the length of the edge + + align:start position:0% +will vary along the length of the edge + + + align:start position:0% +will vary along the length of the edge +so when they did all this whole + + align:start position:0% +so when they did all this whole + + + align:start position:0% +so when they did all this whole +complicated thing they could calculate a + + align:start position:0% +complicated thing they could calculate a + + + align:start position:0% +complicated thing they could calculate a +value for C1 and they calculated 098 so + + align:start position:0% +value for C1 and they calculated 098 so + + + align:start position:0% +value for C1 and they calculated 098 so +it's very close to + + align:start position:0% + + + + align:start position:0% + +one so I'll say + + align:start position:0% +one so I'll say + + + align:start position:0% +one so I'll say +analysis of open + + align:start position:0% + + + + align:start position:0% + +cell tetri decahedron + + align:start position:0% + + + + align:start position:0% + +cells with these Plateau + + align:start position:0% + + + + align:start position:0% + +borders give C1 equal to + + align:start position:0% +borders give C1 equal to + + + align:start position:0% +borders give C1 equal to +98 okay so that's the Young's + + align:start position:0% + + + + align:start position:0% + +modulus we can also look at the shear + + align:start position:0% +modulus we can also look at the shear + + + align:start position:0% +modulus we can also look at the shear +modulus and the shear modulus is also + + align:start position:0% +modulus and the shear modulus is also + + + align:start position:0% +modulus and the shear modulus is also +going to be controlled by bending of the + + align:start position:0% +going to be controlled by bending of the + + + align:start position:0% +going to be controlled by bending of the +cell walls and so the sheer modulus is + + align:start position:0% +cell walls and so the sheer modulus is + + + align:start position:0% +cell walls and so the sheer modulus is +just going to be some other constant + + align:start position:0% +just going to be some other constant + + + align:start position:0% +just going to be some other constant +time es times the relative density + + align:start position:0% +time es times the relative density + + + align:start position:0% +time es times the relative density +squared so a similar kind of + + align:start position:0% +squared so a similar kind of + + + align:start position:0% +squared so a similar kind of +relationship there just a different + + align:start position:0% +relationship there just a different + + + align:start position:0% +relationship there just a different +constant and if the foam's + + align:start position:0% +constant and if the foam's + + + align:start position:0% +constant and if the foam's +isotropic and if the plus On's ratio is + + align:start position:0% +isotropic and if the plus On's ratio is + + + align:start position:0% +isotropic and if the plus On's ratio is +a + + align:start position:0% + + + + align:start position:0% + +third then C2 is equal to + + align:start position:0% +third then C2 is equal to + + + align:start position:0% +third then C2 is equal to + + align:start position:0% + + + + align:start position:0% + +so remember if we have + + align:start position:0% +so remember if we have + + + align:start position:0% +so remember if we have +isotropy then the sheer modulus is equal + + align:start position:0% +isotropy then the sheer modulus is equal + + + align:start position:0% +isotropy then the sheer modulus is equal +to e over 2 1 + + + align:start position:0% +to e over 2 1 + + + + align:start position:0% +to e over 2 1 + +new and so you can get the C2 from that + + align:start position:0% +new and so you can get the C2 from that + + + align:start position:0% +new and so you can get the C2 from that +if you say new is a + + align:start position:0% + + + + align:start position:0% + +third and we can also get pom's ratio + + align:start position:0% +third and we can also get pom's ratio + + + align:start position:0% +third and we can also get pom's ratio +for the foam and if the foam is + + align:start position:0% +for the foam and if the foam is + + + align:start position:0% +for the foam and if the foam is +isotropic so we'll say for an isotropic + + align:start position:0% +isotropic so we'll say for an isotropic + + + align:start position:0% +isotropic so we'll say for an isotropic +foam + + align:start position:0% + + + + align:start position:0% + +here U is equal to e over 2 G minus one + + align:start position:0% +here U is equal to e over 2 G minus one + + + align:start position:0% +here U is equal to e over 2 G minus one +that's just rearranging this expression + + align:start position:0% +that's just rearranging this expression + + + align:start position:0% +that's just rearranging this expression +here and because e and G both depend on + + align:start position:0% +here and because e and G both depend on + + + align:start position:0% +here and because e and G both depend on +the relative density squared they both + + align:start position:0% +the relative density squared they both + + + align:start position:0% +the relative density squared they both +depend on ES squ that's all going to + + align:start position:0% +depend on ES squ that's all going to + + + align:start position:0% +depend on ES squ that's all going to +cancel out and so this is going to be + + align:start position:0% +cancel out and so this is going to be + + + align:start position:0% +cancel out and so this is going to be +equal to C1 over 2 C2 - 1 so that's just + + align:start position:0% +equal to C1 over 2 C2 - 1 so that's just + + + align:start position:0% +equal to C1 over 2 C2 - 1 so that's just +going to equal to a + + align:start position:0% +going to equal to a + + + align:start position:0% +going to equal to a +constant so that constant is going to be + + align:start position:0% +constant so that constant is going to be + + + align:start position:0% +constant so that constant is going to be +independent of whatever material the + + align:start position:0% +independent of whatever material the + + + align:start position:0% +independent of whatever material the +foam is made from and the relative + + align:start position:0% + + + + align:start position:0% + +density and the constant just depends on + + align:start position:0% +density and the constant just depends on + + + align:start position:0% +density and the constant just depends on +the cell + + align:start position:0% +the cell + + + align:start position:0% +the cell +geometry + + align:start position:0% + + + + align:start position:0% + +so remember in Honeycombs we found the + + align:start position:0% +so remember in Honeycombs we found the + + + align:start position:0% +so remember in Honeycombs we found the +same thing the poson ratio for the + + align:start position:0% +same thing the poson ratio for the + + + align:start position:0% +same thing the poson ratio for the +Honeycombs uh only depended on the cell + + align:start position:0% +Honeycombs uh only depended on the cell + + + align:start position:0% +Honeycombs uh only depended on the cell +geometry it didn't depend on the solid + + align:start position:0% +geometry it didn't depend on the solid + + + align:start position:0% +geometry it didn't depend on the solid +properties it didn't depend on the + + align:start position:0% +properties it didn't depend on the + + + align:start position:0% +properties it didn't depend on the +relative density so this is an exactly + + align:start position:0% +relative density so this is an exactly + + + align:start position:0% +relative density so this is an exactly +parallel thing here for the + + align:start position:0% + + + + align:start position:0% + +foams + + align:start position:0% + + + + align:start position:0% + +yep yeah what the difference between and + + align:start position:0% +yep yeah what the difference between and + + + align:start position:0% +yep yeah what the difference between and +honeycom oh so the so the Honeycombs + + align:start position:0% +honeycom oh so the so the Honeycombs + + + align:start position:0% +honeycom oh so the so the Honeycombs +have cells in a plane and they're + + align:start position:0% +have cells in a plane and they're + + + align:start position:0% +have cells in a plane and they're +Prismatic in the third Direction and The + + align:start position:0% +Prismatic in the third Direction and The + + + align:start position:0% +Prismatic in the third Direction and The +Foams have polyhedral cells like um you + + align:start position:0% +Foams have polyhedral cells like um you + + + align:start position:0% +Foams have polyhedral cells like um you +know what a Tetra deed yeah AET like a + + align:start position:0% +know what a Tetra deed yeah AET like a + + + align:start position:0% +know what a Tetra deed yeah AET like a +3D polyhedral cell okay so one the + + align:start position:0% +3D polyhedral cell okay so one the + + + align:start position:0% +3D polyhedral cell okay so one the +Honeycombs are Prismatic and the Foams + + align:start position:0% +Honeycombs are Prismatic and the Foams + + + align:start position:0% +Honeycombs are Prismatic and the Foams +have polyhedral cells okay are we + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% + + + + align:start position:0% + +okay so there's a couple more + + align:start position:0% +okay so there's a couple more + + + align:start position:0% +okay so there's a couple more +interesting things about Pon ratio the + + align:start position:0% +interesting things about Pon ratio the + + + align:start position:0% +interesting things about Pon ratio the +same way we can make Honeycombs with + + align:start position:0% +same way we can make Honeycombs with + + + align:start position:0% +same way we can make Honeycombs with +negative Pon ratios we can also make + + align:start position:0% +negative Pon ratios we can also make + + + align:start position:0% +negative Pon ratios we can also make +Foams with negative Pon + + align:start position:0% + + + + align:start position:0% + +ratios + + align:start position:0% + + + + align:start position:0% + +and they do it the same way as as for + + align:start position:0% +and they do it the same way as as for + + + align:start position:0% +and they do it the same way as as for +the Honeycombs really you know how the + + align:start position:0% +the Honeycombs really you know how the + + + align:start position:0% +the Honeycombs really you know how the +foam the Honeycombs had negative poson + + align:start position:0% +foam the Honeycombs had negative poson + + + align:start position:0% +foam the Honeycombs had negative poson +ratios if the cell walls look like this + + align:start position:0% +ratios if the cell walls look like this + + + align:start position:0% +ratios if the cell walls look like this +this sort of + + align:start position:0% + + + + align:start position:0% + +arrangement so that's sort of a thing so + + align:start position:0% +arrangement so that's sort of a thing so + + + align:start position:0% +arrangement so that's sort of a thing so +we called it say we said that Theta was + + align:start position:0% +we called it say we said that Theta was + + + align:start position:0% +we called it say we said that Theta was +negative for the Honeycombs and if you + + align:start position:0% +negative for the Honeycombs and if you + + + align:start position:0% +negative for the Honeycombs and if you +invert the cell walls on a foam you also + + align:start position:0% +invert the cell walls on a foam you also + + + align:start position:0% +invert the cell walls on a foam you also +get Negative Pence ratios and the way + + align:start position:0% +get Negative Pence ratios and the way + + + align:start position:0% +get Negative Pence ratios and the way +they do that is they take a + + align:start position:0% +they do that is they take a + + + align:start position:0% +they do that is they take a +thermoplastic foam and then they load it + + align:start position:0% +thermoplastic foam and then they load it + + + align:start position:0% +thermoplastic foam and then they load it +hydrostatically so they compress it in + + align:start position:0% +hydrostatically so they compress it in + + + align:start position:0% +hydrostatically so they compress it in +all three directions and they sort of + + align:start position:0% +all three directions and they sort of + + + align:start position:0% +all three directions and they sort of +smoos the cells in on each other and + + align:start position:0% +smoos the cells in on each other and + + + align:start position:0% +smoos the cells in on each other and +then they heat it up to a temperature + + align:start position:0% +then they heat it up to a temperature + + + align:start position:0% +then they heat it up to a temperature +above the glass transition temperature + + align:start position:0% +above the glass transition temperature + + + align:start position:0% +above the glass transition temperature +while it's still smooshed and then they + + align:start position:0% +while it's still smooshed and then they + + + align:start position:0% +while it's still smooshed and then they +cool it down so they end up with the + + align:start position:0% +cool it down so they end up with the + + + align:start position:0% +cool it down so they end up with the +that structure kind of Frozen in and if + + align:start position:0% +that structure kind of Frozen in and if + + + align:start position:0% +that structure kind of Frozen in and if +they do that they get a negative poson + + align:start position:0% +they do that they get a negative poson + + + align:start position:0% +they do that they get a negative poson +ratio + + align:start position:0% + + + + align:start position:0% + +so I'll just say they invert the cell + + align:start position:0% +so I'll just say they invert the cell + + + align:start position:0% +so I'll just say they invert the cell +angles analagous to the + + align:start position:0% + + + + align:start position:0% + +honeycomb + + align:start position:0% + + + + align:start position:0% + +so they load the foam + + align:start position:0% +so they load the foam + + + align:start position:0% +so they load the foam +hydrostatically and + + align:start position:0% +hydrostatically and + + + align:start position:0% +hydrostatically and +heat to a + + align:start position:0% +heat to a + + + align:start position:0% +heat to a +temperature above TG and then they cool + + align:start position:0% +temperature above TG and then they cool + + + align:start position:0% +temperature above TG and then they cool +and release + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% + + + + align:start position:0% + +so I have a photograph here of a foam + + align:start position:0% +so I have a photograph here of a foam + + + align:start position:0% +so I have a photograph here of a foam +with a negative plus ratio so you can + + align:start position:0% +with a negative plus ratio so you can + + + align:start position:0% +with a negative plus ratio so you can +see how the cells have been sort of + + align:start position:0% +see how the cells have been sort of + + + align:start position:0% +see how the cells have been sort of +smooshed in and it's the equivalent of + + align:start position:0% +smooshed in and it's the equivalent of + + + align:start position:0% +smooshed in and it's the equivalent of +the way it's done for the honeycomb okay + + align:start position:0% +the way it's done for the honeycomb okay + + + align:start position:0% +the way it's done for the honeycomb okay +are we good + + align:start position:0% +are we good + + + align:start position:0% +are we good +okay + + align:start position:0% + + + + align:start position:0% + +so that's the linear elastic modui for + + align:start position:0% +so that's the linear elastic modui for + + + align:start position:0% +so that's the linear elastic modui for +open cell Foams and the next thing I + + align:start position:0% +open cell Foams and the next thing I + + + align:start position:0% +open cell Foams and the next thing I +wanted to do was closed cell Foams so if + + align:start position:0% +wanted to do was closed cell Foams so if + + + align:start position:0% +wanted to do was closed cell Foams so if +we look at a closed cell foam we can + + align:start position:0% +we look at a closed cell foam we can + + + align:start position:0% +we look at a closed cell foam we can +sort of idealize it in this kind of way + + align:start position:0% +sort of idealize it in this kind of way + + + align:start position:0% +sort of idealize it in this kind of way +here so I've set it up so that the edge + + align:start position:0% +here so I've set it up so that the edge + + + align:start position:0% +here so I've set it up so that the edge +thickness is different from the face + + align:start position:0% +thickness is different from the face + + + align:start position:0% +thickness is different from the face +thickness and that's really representing + + align:start position:0% +thickness and that's really representing + + + align:start position:0% +thickness and that's really representing +the the fact that in Foams many Foams + + align:start position:0% +the the fact that in Foams many Foams + + + align:start position:0% +the the fact that in Foams many Foams +are made using a liquid that is and the + + align:start position:0% +are made using a liquid that is and the + + + align:start position:0% +are made using a liquid that is and the +foaming is controlled by surface tension + + align:start position:0% +foaming is controlled by surface tension + + + align:start position:0% +foaming is controlled by surface tension +and often the surface tension draws + + align:start position:0% +and often the surface tension draws + + + align:start position:0% +and often the surface tension draws +material into the edges and away from + + align:start position:0% +material into the edges and away from + + + align:start position:0% +material into the edges and away from +the faces so the faces tend to be thick + + align:start position:0% +the faces so the faces tend to be thick + + + align:start position:0% +the faces so the faces tend to be thick +thinner than the edges so when we have + + align:start position:0% +thinner than the edges so when we have + + + align:start position:0% +thinner than the edges so when we have +deformation of the uh closed cell foam + + align:start position:0% +deformation of the uh closed cell foam + + + align:start position:0% +deformation of the uh closed cell foam +we've got bending of the edges the same + + align:start position:0% +we've got bending of the edges the same + + + align:start position:0% +we've got bending of the edges the same +as we did for the open cell foam but the + + align:start position:0% +as we did for the open cell foam but the + + + align:start position:0% +as we did for the open cell foam but the +faces can stretch so they can have sort + + align:start position:0% +faces can stretch so they can have sort + + + align:start position:0% +faces can stretch so they can have sort +of an axial stretching so you can think + + align:start position:0% +of an axial stretching so you can think + + + align:start position:0% +of an axial stretching so you can think +of that as sort of a cell membrane + + align:start position:0% +of that as sort of a cell membrane + + + align:start position:0% +of that as sort of a cell membrane +stretching here so imagine if I either + + align:start position:0% +stretching here so imagine if I either + + + align:start position:0% +stretching here so imagine if I either +pull on the foam or I compress it + + align:start position:0% +pull on the foam or I compress it + + + align:start position:0% +pull on the foam or I compress it +there's going to be some axial load in + + align:start position:0% +there's going to be some axial load in + + + align:start position:0% +there's going to be some axial load in +the faces and so when we analyze them we + + align:start position:0% +the faces and so when we analyze them we + + + align:start position:0% +the faces and so when we analyze them we +have to account for both bending of the + + align:start position:0% +have to account for both bending of the + + + align:start position:0% +have to account for both bending of the +edges and axial deformation in the + + align:start position:0% +edges and axial deformation in the + + + align:start position:0% +edges and axial deformation in the +faces so I'll just say we + + align:start position:0% + + + + align:start position:0% + +have Edge + + align:start position:0% + + + + align:start position:0% + +bending as in open cell + + align:start position:0% + + + + align:start position:0% + +foams + + align:start position:0% +foams + + + align:start position:0% +foams +and we also get face + + align:start position:0% + + + + align:start position:0% + +stretching and another thing that can + + align:start position:0% +stretching and another thing that can + + + align:start position:0% +stretching and another thing that can +happen in the closed cell Foams is we + + align:start position:0% +happen in the closed cell Foams is we + + + align:start position:0% +happen in the closed cell Foams is we +can get compression of the gas so in an + + align:start position:0% +can get compression of the gas so in an + + + align:start position:0% +can get compression of the gas so in an +open cell foam the gas can move from one + + align:start position:0% +open cell foam the gas can move from one + + + align:start position:0% +open cell foam the gas can move from one +cell to the next but in a closed cell + + align:start position:0% +cell to the next but in a closed cell + + + align:start position:0% +cell to the next but in a closed cell +foam the gas is trapped and as the + + align:start position:0% +foam the gas is trapped and as the + + + align:start position:0% +foam the gas is trapped and as the +volume of the um cell changes the gas + + align:start position:0% +volume of the um cell changes the gas + + + align:start position:0% +volume of the um cell changes the gas +gets + + align:start position:0% + + + + align:start position:0% + +compressed so we have another effect + + align:start position:0% + + + + align:start position:0% + +here so we'll say for polymer Foams + + align:start position:0% +here so we'll say for polymer Foams + + + align:start position:0% +here so we'll say for polymer Foams +surface + + align:start position:0% +surface + + + align:start position:0% +surface +tension tends to draw material to the + + align:start position:0% +tension tends to draw material to the + + + align:start position:0% +tension tends to draw material to the +edges during + + align:start position:0% + + + + align:start position:0% + +processing + + align:start position:0% + + + + align:start position:0% + +so we Define two two thicknesses one for + + align:start position:0% +so we Define two two thicknesses one for + + + align:start position:0% +so we Define two two thicknesses one for +the edge and one for the + + align:start position:0% +the edge and one for the + + + align:start position:0% +the edge and one for the +face and then we apply a force to this + + align:start position:0% +face and then we apply a force to this + + + align:start position:0% +face and then we apply a force to this +cubic kind of + + align:start position:0% + + + + align:start position:0% + +structure and we can do an analysis a + + align:start position:0% +structure and we can do an analysis a + + + align:start position:0% +structure and we can do an analysis a +little bit like what we did for the open + + align:start position:0% +little bit like what we did for the open + + + align:start position:0% +little bit like what we did for the open +cell + + align:start position:0% + + + + align:start position:0% + +foam let me rub all this + + align:start position:0% + + + + align:start position:0% + +off + + align:start position:0% + + + + align:start position:0% + +okay so I'm going to set this up a + + align:start position:0% +okay so I'm going to set this up a + + + align:start position:0% +okay so I'm going to set this up a +little bit differently um than for the + + align:start position:0% +little bit differently um than for the + + + align:start position:0% +little bit differently um than for the +open cell foam we're going to do a work + + align:start position:0% +open cell foam we're going to do a work + + + align:start position:0% +open cell foam we're going to do a work +argument so we're going to look at the + + align:start position:0% +argument so we're going to look at the + + + align:start position:0% +argument so we're going to look at the +external work done by the force F going + + align:start position:0% +external work done by the force F going + + + align:start position:0% +external work done by the force F going +through a deformation Delta and that's + + align:start position:0% +through a deformation Delta and that's + + + align:start position:0% +through a deformation Delta and that's +going to have to equal the internal work + + align:start position:0% +going to have to equal the internal work + + + align:start position:0% +going to have to equal the internal work +done by the edges bending and by the + + align:start position:0% +done by the edges bending and by the + + + align:start position:0% +done by the edges bending and by the +faces stretching so let me set that up + + align:start position:0% +faces stretching so let me set that up + + + align:start position:0% +faces stretching so let me set that up +so we're going to see the external work + + align:start position:0% + + + + align:start position:0% + +done that's going to be proportional to + + align:start position:0% +done that's going to be proportional to + + + align:start position:0% +done that's going to be proportional to +F time Delta so Delta is how much the + + align:start position:0% +F time Delta so Delta is how much the + + + align:start position:0% +F time Delta so Delta is how much the +whole thing is going to + + align:start position:0% +whole thing is going to + + + align:start position:0% +whole thing is going to +deform and then I've got internal + + align:start position:0% +deform and then I've got internal + + + align:start position:0% +deform and then I've got internal +work from bending of the + + align:start position:0% + + + + align:start position:0% + +edges and that internal work + + align:start position:0% +edges and that internal work + + + align:start position:0% +edges and that internal work +is going to be proportional + + align:start position:0% +is going to be proportional + + + align:start position:0% +is going to be proportional +to F over + + align:start position:0% +to F over + + + align:start position:0% +to F over +Delta time Delta squar I'm going to end + + align:start position:0% +Delta time Delta squar I'm going to end + + + align:start position:0% +Delta time Delta squar I'm going to end +up with an expression where everything's + + align:start position:0% +up with an expression where everything's + + + align:start position:0% +up with an expression where everything's +in Delta squared so I want to keep the + + align:start position:0% +in Delta squared so I want to keep the + + + align:start position:0% +in Delta squared so I want to keep the +Delta squared there for now and F over + + align:start position:0% +Delta squared there for now and F over + + + align:start position:0% +Delta squared there for now and F over +Delta is the stiffness and that's going + + align:start position:0% +Delta is the stiffness and that's going + + + align:start position:0% +Delta is the stiffness and that's going +to go as e of the solid * I over L + + align:start position:0% + + + + align:start position:0% + +cub and I is going to go as te to the + + align:start position:0% +cub and I is going to go as te to the + + + align:start position:0% +cub and I is going to go as te to the +4th here because it's I of the edges + + align:start position:0% +4th here because it's I of the edges + + + align:start position:0% +4th here because it's I of the edges +then I've also got internal work from + + align:start position:0% +then I've also got internal work from + + + align:start position:0% +then I've also got internal work from +stretching of the + + align:start position:0% + + + + align:start position:0% + +faces and that internal work is going to + + align:start position:0% +faces and that internal work is going to + + + align:start position:0% +faces and that internal work is going to +be I'm going to run into my other + + align:start position:0% +be I'm going to run into my other + + + align:start position:0% +be I'm going to run into my other +equations here let me put it down a + + align:start position:0% +equations here let me put it down a + + + align:start position:0% +equations here let me put it down a +little that's going to go as the stress + + align:start position:0% +little that's going to go as the stress + + + align:start position:0% +little that's going to go as the stress +in the face times The Strain in the face + + align:start position:0% +in the face times The Strain in the face + + + align:start position:0% +in the face times The Strain in the face +times the volume of the face okay + + align:start position:0% +times the volume of the face okay + + + align:start position:0% +times the volume of the face okay +or I could write that instead of stress + + align:start position:0% +or I could write that instead of stress + + + align:start position:0% +or I could write that instead of stress +of the face I can put it in terms of + + align:start position:0% +of the face I can put it in terms of + + + align:start position:0% +of the face I can put it in terms of +hooks law and say it's e of the solid + + align:start position:0% +hooks law and say it's e of the solid + + + align:start position:0% +hooks law and say it's e of the solid +time the strain in the face squared time + + align:start position:0% +time the strain in the face squared time + + + align:start position:0% +time the strain in the face squared time +the volume of the face and I can replace + + align:start position:0% +the volume of the face and I can replace + + + align:start position:0% +the volume of the face and I can replace +the strain in the face by Delta over + + align:start position:0% + + + + align:start position:0% + +l so it's Delta over l s and then the + + align:start position:0% +l so it's Delta over l s and then the + + + align:start position:0% +l so it's Delta over l s and then the +volume of the face is going to be T of + + align:start position:0% +volume of the face is going to be T of + + + align:start position:0% +volume of the face is going to be T of +the + + align:start position:0% +the + + + align:start position:0% +the +face * l^2 + + align:start position:0% + + + + align:start position:0% + +so then I want to balance the internal + + align:start position:0% +so then I want to balance the internal + + + align:start position:0% +so then I want to balance the internal +work and the external work and so I can + + align:start position:0% +work and the external work and so I can + + + align:start position:0% +work and the external work and so I can +say f * Delta is going to equal some + + align:start position:0% +say f * Delta is going to equal some + + + align:start position:0% +say f * Delta is going to equal some +constant I'm going to call + + align:start position:0% +constant I'm going to call + + + align:start position:0% +constant I'm going to call +Alpha time e of the + + align:start position:0% +Alpha time e of the + + + align:start position:0% +Alpha time e of the +solid T of the edge to the 4th that's + + align:start position:0% +solid T of the edge to the 4th that's + + + align:start position:0% +solid T of the edge to the 4th that's +this guy up here over L + + align:start position:0% +this guy up here over L + + + align:start position:0% +this guy up here over L +cubed * Delta squar and then plus some + + align:start position:0% +cubed * Delta squar and then plus some + + + align:start position:0% +cubed * Delta squar and then plus some +other constant I'm going to call + + align:start position:0% +other constant I'm going to call + + + align:start position:0% +other constant I'm going to call +beta * e of the + + align:start position:0% + + + + align:start position:0% + +solid Delta + + align:start position:0% +solid Delta + + + align:start position:0% +solid Delta +l^2 TF + + align:start position:0% + + + + align:start position:0% + +l^2 so so far I've got this in terms of + + align:start position:0% +l^2 so so far I've got this in terms of + + + align:start position:0% +l^2 so so far I've got this in terms of +the force I'm applying but I want to get + + align:start position:0% +the force I'm applying but I want to get + + + align:start position:0% +the force I'm applying but I want to get +a modulus of the foam out of this and so + + align:start position:0% +a modulus of the foam out of this and so + + + align:start position:0% +a modulus of the foam out of this and so +I want to relate this Force here to the + + align:start position:0% +I want to relate this Force here to the + + + align:start position:0% +I want to relate this Force here to the +modulus of the foam and I can say the + + align:start position:0% +modulus of the foam and I can say the + + + align:start position:0% +modulus of the foam and I can say the +modulus of the foam is going to be + + align:start position:0% +modulus of the foam is going to be + + + align:start position:0% +modulus of the foam is going to be +related to f l s that's the stress ID + + align:start position:0% +related to f l s that's the stress ID + + + align:start position:0% +related to f l s that's the stress ID +The Strain Delta L and so I can write + + align:start position:0% +The Strain Delta L and so I can write + + + align:start position:0% +The Strain Delta L and so I can write +the + + align:start position:0% +the + + + align:start position:0% +the +force is proportional to the modulus + + align:start position:0% +force is proportional to the modulus + + + align:start position:0% +force is proportional to the modulus +time the deflection Delta and times the + + align:start position:0% +time the deflection Delta and times the + + + align:start position:0% +time the deflection Delta and times the +member length L and then I'm going to + + align:start position:0% +member length L and then I'm going to + + + align:start position:0% +member length L and then I'm going to +plug that guy into this expression up + + align:start position:0% +plug that guy into this expression up + + + align:start position:0% +plug that guy into this expression up +here and I'm going to get a Delta squar + + align:start position:0% +here and I'm going to get a Delta squar + + + align:start position:0% +here and I'm going to get a Delta squar +on the left and I'm going to get Delta + + align:start position:0% +on the left and I'm going to get Delta + + + align:start position:0% +on the left and I'm going to get Delta +squs in each of the right hand terms and + + align:start position:0% +squs in each of the right hand terms and + + + align:start position:0% +squs in each of the right hand terms and +so I'm going to cancel out the + + align:start position:0% + + + + align:start position:0% + +Deltas so if I put all that together I + + align:start position:0% +Deltas so if I put all that together I + + + align:start position:0% +Deltas so if I put all that together I +have the modulus of the foam time Delta + + align:start position:0% +have the modulus of the foam time Delta + + + align:start position:0% +have the modulus of the foam time Delta +s * l so there's a Delta here and + + align:start position:0% +s * l so there's a Delta here and + + + align:start position:0% +s * l so there's a Delta here and +there's a Delta there it gives me Delta + + align:start position:0% + + + + align:start position:0% + +squar and that's going to equal + + align:start position:0% +squar and that's going to equal + + + align:start position:0% +squar and that's going to equal +Alpha es + + align:start position:0% +Alpha es + + + align:start position:0% +Alpha es +s t e + + align:start position:0% +s t e + + + align:start position:0% +s t e +4th over L + + align:start position:0% +4th over L + + + align:start position:0% +4th over L +cubed * Delta 2 + beta * e s + + align:start position:0% +cubed * Delta 2 + beta * e s + + + align:start position:0% +cubed * Delta 2 + beta * e s +* Delta + + align:start position:0% +* Delta + + + align:start position:0% +* Delta +2 TF if I cancel out one of those l + + align:start position:0% +2 TF if I cancel out one of those l + + + align:start position:0% +2 TF if I cancel out one of those l +squs so here I can get rid of the Delta + + align:start position:0% +squs so here I can get rid of the Delta + + + align:start position:0% +squs so here I can get rid of the Delta +squares in all these + + align:start position:0% +squares in all these + + + align:start position:0% +squares in all these +terms and if I just divide by L I'm + + align:start position:0% +terms and if I just divide by L I'm + + + align:start position:0% +terms and if I just divide by L I'm +going to have the modulus of the + + align:start position:0% + + + + align:start position:0% + +foam so I get a term here that it goes + + align:start position:0% +foam so I get a term here that it goes + + + align:start position:0% +foam so I get a term here that it goes +as Alpha e of the solid time T of the + + align:start position:0% +as Alpha e of the solid time T of the + + + align:start position:0% +as Alpha e of the solid time T of the +edge over L 4th power plus beta time e + + align:start position:0% +edge over L 4th power plus beta time e + + + align:start position:0% +edge over L 4th power plus beta time e +of the + + align:start position:0% + + + + align:start position:0% + +solid time TF over + + align:start position:0% + + + + align:start position:0% + +L are we + + align:start position:0% +L are we + + + align:start position:0% +L are we +good okay and what I'd like to do is + + align:start position:0% +good okay and what I'd like to do is + + + align:start position:0% +good okay and what I'd like to do is +instead of putting it in terms of te and + + align:start position:0% +instead of putting it in terms of te and + + + align:start position:0% +instead of putting it in terms of te and +TF I'd like to put it in terms of the + + align:start position:0% +TF I'd like to put it in terms of the + + + align:start position:0% +TF I'd like to put it in terms of the +relative + + align:start position:0% +relative + + + align:start position:0% +relative +density so I'm going to look at two + + align:start position:0% +density so I'm going to look at two + + + align:start position:0% +density so I'm going to look at two +limits so I'm going to say if we just + + align:start position:0% +limits so I'm going to say if we just + + + align:start position:0% +limits so I'm going to say if we just +had open cells if there were no faces on + + align:start position:0% +had open cells if there were no faces on + + + align:start position:0% +had open cells if there were no faces on +the membranes if we just had open cells + + align:start position:0% +the membranes if we just had open cells + + + align:start position:0% +the membranes if we just had open cells +and we had a uniform + + align:start position:0% +and we had a uniform + + + align:start position:0% +and we had a uniform +T then the relative + + align:start position:0% +T then the relative + + + align:start position:0% +T then the relative +density would go as T + + align:start position:0% + + + + align:start position:0% + +l^2 and if I just had closed cells and I + + align:start position:0% +l^2 and if I just had closed cells and I + + + align:start position:0% +l^2 and if I just had closed cells and I +had a uniform + + align:start position:0% + + + + align:start position:0% + +T then the relative + + align:start position:0% +T then the relative + + + align:start position:0% +T then the relative +density just goes linearly with t + + align:start position:0% +density just goes linearly with t + + + align:start position:0% +density just goes linearly with t +l so the relative density is the volume + + align:start position:0% +l so the relative density is the volume + + + align:start position:0% +l so the relative density is the volume +fraction of + + align:start position:0% +fraction of + + + align:start position:0% +fraction of +solids so it's the um volume of the + + align:start position:0% +solids so it's the um volume of the + + + align:start position:0% +solids so it's the um volume of the +solid over the total volume and for a + + align:start position:0% +solid over the total volume and for a + + + align:start position:0% +solid over the total volume and for a +close cell foam with a uniform T the + + align:start position:0% +close cell foam with a uniform T the + + + align:start position:0% +close cell foam with a uniform T the +volume of the solid is going to be T * + + align:start position:0% +volume of the solid is going to be T * + + + align:start position:0% +volume of the solid is going to be T * +l^ 2 and then the volume total is L + + align:start position:0% +l^ 2 and then the volume total is L + + + align:start position:0% +l^ 2 and then the volume total is L +cubed so it's t + + align:start position:0% +cubed so it's t + + + align:start position:0% +cubed so it's t +l and now I'm going to Define one more + + align:start position:0% +l and now I'm going to Define one more + + + align:start position:0% +l and now I'm going to Define one more +thing if I say that f is equal to the + + align:start position:0% +thing if I say that f is equal to the + + + align:start position:0% +thing if I say that f is equal to the +volume of fraction of the solid in the + + align:start position:0% + + + + align:start position:0% + +edges then I can + + align:start position:0% +edges then I can + + + align:start position:0% +edges then I can +say t over L is some constant Time 5 12 + + align:start position:0% +say t over L is some constant Time 5 12 + + + align:start position:0% +say t over L is some constant Time 5 12 +time the relative density of + + align:start position:0% +time the relative density of + + + align:start position:0% +time the relative density of +12 and I can say TF over l + + align:start position:0% + + + + align:start position:0% + +is equal to some other constant C Prime + + align:start position:0% +is equal to some other constant C Prime + + + align:start position:0% +is equal to some other constant C Prime +I'll call it Time 1 minus 5 that's how + + align:start position:0% +I'll call it Time 1 minus 5 that's how + + + align:start position:0% +I'll call it Time 1 minus 5 that's how +much is in the faces times the relative + + align:start position:0% + + + + align:start position:0% + +density and then I combine all + + align:start position:0% +density and then I combine all + + + align:start position:0% +density and then I combine all +this can I put it in here maybe I'll + + align:start position:0% +this can I put it in here maybe I'll + + + align:start position:0% +this can I put it in here maybe I'll +just stick it down + + align:start position:0% + + + + align:start position:0% + +here hang on + + align:start position:0% +here hang on + + + align:start position:0% +here hang on +okay put it up here + + align:start position:0% + + + + align:start position:0% + +so this is my final expression here and + + align:start position:0% +so this is my final expression here and + + + align:start position:0% +so this is my final expression here and +this term here arises from The Edge + + align:start position:0% + + + + align:start position:0% + +bending and this term here arises from + + align:start position:0% +bending and this term here arises from + + + align:start position:0% +bending and this term here arises from +the face + + align:start position:0% + + + + align:start position:0% + +stretching so I think I should wait a + + align:start position:0% +stretching so I think I should wait a + + + align:start position:0% +stretching so I think I should wait a +bit for you to catch + + align:start position:0% + + + + align:start position:0% + +up so the idea is the edges are bending + + align:start position:0% +up so the idea is the edges are bending + + + align:start position:0% +up so the idea is the edges are bending +the faces are stretching we're looking + + align:start position:0% +the faces are stretching we're looking + + + align:start position:0% +the faces are stretching we're looking +at the work done by deforming the edges + + align:start position:0% +at the work done by deforming the edges + + + align:start position:0% +at the work done by deforming the edges +and the faces and equating that to the + + align:start position:0% +and the faces and equating that to the + + + align:start position:0% +and the faces and equating that to the +work done by the externally applied load + + align:start position:0% +work done by the externally applied load + + + align:start position:0% +work done by the externally applied load +f + + align:start position:0% + + + + align:start position:0% + +okay so that gives us two terms one that + + align:start position:0% +okay so that gives us two terms one that + + + align:start position:0% +okay so that gives us two terms one that +accounts for the edge bending and one + + align:start position:0% +accounts for the edge bending and one + + + align:start position:0% +accounts for the edge bending and one +that accounts for the face + + align:start position:0% +that accounts for the face + + + align:start position:0% +that accounts for the face +stretching um and to be comprehensive we + + align:start position:0% +stretching um and to be comprehensive we + + + align:start position:0% +stretching um and to be comprehensive we +want to take take into account the + + align:start position:0% +want to take take into account the + + + align:start position:0% +want to take take into account the +compression of the gas as well so + + align:start position:0% +compression of the gas as well so + + + align:start position:0% +compression of the gas as well so +there's one more term I'm going to add + + align:start position:0% +there's one more term I'm going to add + + + align:start position:0% +there's one more term I'm going to add +on to + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +so typically the gas um effect is only + + align:start position:0% +so typically the gas um effect is only + + + align:start position:0% +so typically the gas um effect is only +significant for elastomeric Foams it's + + align:start position:0% +significant for elastomeric Foams it's + + + align:start position:0% +significant for elastomeric Foams it's +if you had a metal foam or a ceramic + + align:start position:0% +if you had a metal foam or a ceramic + + + align:start position:0% +if you had a metal foam or a ceramic +foam that was closed cell it wouldn't + + align:start position:0% +foam that was closed cell it wouldn't + + + align:start position:0% +foam that was closed cell it wouldn't +really contribute much but just to be + + align:start position:0% +really contribute much but just to be + + + align:start position:0% +really contribute much but just to be +complete we'll go through + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +so the idea here is we say we've got a + + align:start position:0% +so the idea here is we say we've got a + + + align:start position:0% +so the idea here is we say we've got a +cubic element of the foam and initially + + align:start position:0% +cubic element of the foam and initially + + + align:start position:0% +cubic element of the foam and initially +it has a volume v KN and if we apply a a + + align:start position:0% +it has a volume v KN and if we apply a a + + + align:start position:0% +it has a volume v KN and if we apply a a +stress a uni axial stress uh there's + + align:start position:0% +stress a uni axial stress uh there's + + + align:start position:0% +stress a uni axial stress uh there's +some change in the volume of the foam so + + align:start position:0% +some change in the volume of the foam so + + + align:start position:0% +some change in the volume of the foam so +there's some um volume v after we + + align:start position:0% +there's some um volume v after we + + + align:start position:0% +there's some um volume v after we +compress it by some strain Epsilon and + + align:start position:0% +compress it by some strain Epsilon and + + + align:start position:0% +compress it by some strain Epsilon and +if we can figure out what the volume is + + align:start position:0% +if we can figure out what the volume is + + + align:start position:0% +if we can figure out what the volume is +relative to the initial volume we can + + align:start position:0% +relative to the initial volume we can + + + align:start position:0% +relative to the initial volume we can +figure out how the change of the amount + + align:start position:0% +figure out how the change of the amount + + + align:start position:0% +figure out how the change of the amount +of gas uh goes from the initial state to + + align:start position:0% +of gas uh goes from the initial state to + + + align:start position:0% +of gas uh goes from the initial state to +the compressed State and then we can use + + align:start position:0% +the compressed State and then we can use + + + align:start position:0% +the compressed State and then we can use +boils law so the idea is P1 V1 equals P2 + + align:start position:0% +boils law so the idea is P1 V1 equals P2 + + + align:start position:0% +boils law so the idea is P1 V1 equals P2 +V2 so then we can figure out using Bo's + + align:start position:0% +V2 so then we can figure out using Bo's + + + align:start position:0% +V2 so then we can figure out using Bo's +law what the pressure must be and then + + align:start position:0% +law what the pressure must be and then + + + align:start position:0% +law what the pressure must be and then +that pressure is what's contributing to + + align:start position:0% +that pressure is what's contributing to + + + align:start position:0% +that pressure is what's contributing to +the + + align:start position:0% +the + + + align:start position:0% +the +modulus so when I do this I'm going to + + align:start position:0% +modulus so when I do this I'm going to + + + align:start position:0% +modulus so when I do this I'm going to +write down some equations that just have + + align:start position:0% +write down some equations that just have + + + align:start position:0% +write down some equations that just have +the main results there's a whole bunch + + align:start position:0% +the main results there's a whole bunch + + + align:start position:0% +the main results there's a whole bunch +of algebra just to get from one to the + + align:start position:0% +of algebra just to get from one to the + + + align:start position:0% +of algebra just to get from one to the +other and I'm not going to write them + + align:start position:0% +other and I'm not going to write them + + + align:start position:0% +other and I'm not going to write them +all down so it's not like when I write + + align:start position:0% +all down so it's not like when I write + + + align:start position:0% +all down so it's not like when I write +the equations Don't Panic if it's not + + align:start position:0% +the equations Don't Panic if it's not + + + align:start position:0% +the equations Don't Panic if it's not +obvious how you get from one to the + + align:start position:0% +obvious how you get from one to the + + + align:start position:0% +obvious how you get from one to the +other in the notes that I'm going to put + + align:start position:0% +other in the notes that I'm going to put + + + align:start position:0% +other in the notes that I'm going to put +online there's the there's all the + + align:start position:0% +online there's the there's all the + + + align:start position:0% +online there's the there's all the +details of how you get from one to the + + align:start position:0% +details of how you get from one to the + + + align:start position:0% +details of how you get from one to the +other uh so the idea is that we start + + align:start position:0% +other uh so the idea is that we start + + + align:start position:0% +other uh so the idea is that we start +with a cubic + + align:start position:0% + + + + align:start position:0% + +element of + + align:start position:0% + + + + align:start position:0% + +foam + + align:start position:0% +foam + + + align:start position:0% +foam +and initially before it's loaded it has + + align:start position:0% +and initially before it's loaded it has + + + align:start position:0% +and initially before it's loaded it has +a volume v + + align:start position:0% +a volume v + + + align:start position:0% +a volume v +knot and then we apply a uniaxial + + align:start position:0% + + + + align:start position:0% + +stress and we say the axial strain in + + align:start position:0% +stress and we say the axial strain in + + + align:start position:0% +stress and we say the axial strain in +the direction of the stress I'm going to + + align:start position:0% +the direction of the stress I'm going to + + + align:start position:0% +the direction of the stress I'm going to +call + + align:start position:0% + + + + align:start position:0% + +Epsilon + + align:start position:0% + + + + align:start position:0% + +and just from the geometry you can + + align:start position:0% +and just from the geometry you can + + + align:start position:0% +and just from the geometry you can +calculate the deformed + + align:start position:0% + + + + align:start position:0% + +volume so after you loaded the volume's + + align:start position:0% +volume so after you loaded the volume's + + + align:start position:0% +volume so after you loaded the volume's +V and that volume on loading V divided + + align:start position:0% +V and that volume on loading V divided + + + align:start position:0% +V and that volume on loading V divided +by the initial volume v KN you can show + + align:start position:0% +by the initial volume v KN you can show + + + align:start position:0% +by the initial volume v KN you can show +it's fairly straightforward is 1 minus + + align:start position:0% +it's fairly straightforward is 1 minus + + + align:start position:0% +it's fairly straightforward is 1 minus +Epsilon * 1 - 2 * the POS ratio of the + + align:start position:0% +Epsilon * 1 - 2 * the POS ratio of the + + + align:start position:0% +Epsilon * 1 - 2 * the POS ratio of the +phone so here I'm taking impressive + + align:start position:0% +phone so here I'm taking impressive + + + align:start position:0% +phone so here I'm taking impressive +strain is + + align:start position:0% + + + + align:start position:0% + +positive and if you do this whole volume + + align:start position:0% +positive and if you do this whole volume + + + align:start position:0% +positive and if you do this whole volume +thing you you'll get terms in epsilon + + align:start position:0% +thing you you'll get terms in epsilon + + + align:start position:0% +thing you you'll get terms in epsilon +squar and Epsilon cubed but because it's + + align:start position:0% +squar and Epsilon cubed but because it's + + + align:start position:0% +squar and Epsilon cubed but because it's +linear elastic Epsilon is going to be + + align:start position:0% +linear elastic Epsilon is going to be + + + align:start position:0% +linear elastic Epsilon is going to be +small I'm going to ignore the Epsilon + + align:start position:0% +small I'm going to ignore the Epsilon + + + align:start position:0% +small I'm going to ignore the Epsilon +squ and the Epsilon cubed + + align:start position:0% + + + + align:start position:0% + +terms so that's the total volume of the + + align:start position:0% +terms so that's the total volume of the + + + align:start position:0% +terms so that's the total volume of the +foam after and before the + + align:start position:0% +foam after and before the + + + align:start position:0% +foam after and before the +compression and then what I want is the + + align:start position:0% +compression and then what I want is the + + + align:start position:0% +compression and then what I want is the +volume of the gas and the volume of the + + align:start position:0% +volume of the gas and the volume of the + + + align:start position:0% +volume of the gas and the volume of the +gas is just going to be the volume minus + + align:start position:0% +gas is just going to be the volume minus + + + align:start position:0% +gas is just going to be the volume minus +the volume of the solid and I can get + + align:start position:0% +the volume of the solid and I can get + + + align:start position:0% +the volume of the solid and I can get +that by just subtracting off the + + align:start position:0% +that by just subtracting off the + + + align:start position:0% +that by just subtracting off the +relative density so VG over VG KN so + + align:start position:0% +relative density so VG over VG KN so + + + align:start position:0% +relative density so VG over VG KN so +again VG KN is the volume of the gas + + align:start position:0% +again VG KN is the volume of the gas + + + align:start position:0% +again VG KN is the volume of the gas +initially VG is the volume of the gas um + + align:start position:0% +initially VG is the volume of the gas um + + + align:start position:0% +initially VG is the volume of the gas um +when I'm compressing + + align:start position:0% + + + + align:start position:0% + +it + + align:start position:0% + + + + align:start position:0% + +remember the relative density is the + + align:start position:0% +remember the relative density is the + + + align:start position:0% +remember the relative density is the +volume fraction of solid so I'm + + align:start position:0% +volume fraction of solid so I'm + + + align:start position:0% +volume fraction of solid so I'm +essentially subtracting out the amount + + align:start position:0% +essentially subtracting out the amount + + + align:start position:0% +essentially subtracting out the amount +of solid to get the amount of + + align:start position:0% + + + + align:start position:0% + +gas + + align:start position:0% + + + + align:start position:0% + +then we can use Bo's + + align:start position:0% + + + + align:start position:0% + +law and here p is going to be the + + align:start position:0% +law and here p is going to be the + + + align:start position:0% +law and here p is going to be the +pressure after the strain and P KN is + + align:start position:0% +pressure after the strain and P KN is + + + align:start position:0% +pressure after the strain and P KN is +going to be the initial + + align:start position:0% +going to be the initial + + + align:start position:0% +going to be the initial +pressure + + align:start position:0% + + + + align:start position:0% + +the building seems rather making unhappy + + align:start position:0% +the building seems rather making unhappy + + + align:start position:0% +the building seems rather making unhappy +noises for some reason I'm not sure what + + align:start position:0% +noises for some reason I'm not sure what + + + align:start position:0% +noises for some reason I'm not sure what +that's all + + align:start position:0% + + + + align:start position:0% + +about and there'll be some initial + + align:start position:0% +about and there'll be some initial + + + align:start position:0% +about and there'll be some initial +pressure in the gas even before the + + align:start position:0% +pressure in the gas even before the + + + align:start position:0% +pressure in the gas even before the +strain or before the stress is applied + + align:start position:0% +strain or before the stress is applied + + + align:start position:0% +strain or before the stress is applied +that's P so the pressure we need to + + align:start position:0% +that's P so the pressure we need to + + + align:start position:0% +that's P so the pressure we need to +overcome is p minus + + align:start position:0% + + + + align:start position:0% + +p and again I'm missing out a bunch of + + align:start position:0% +p and again I'm missing out a bunch of + + + align:start position:0% +p and again I'm missing out a bunch of +steps but you can you know using that + + align:start position:0% +steps but you can you know using that + + + align:start position:0% +steps but you can you know using that +expression and this expression and this + + align:start position:0% +expression and this expression and this + + + align:start position:0% +expression and this expression and this +expression you can find that P Prime is + + align:start position:0% +expression you can find that P Prime is + + + align:start position:0% +expression you can find that P Prime is +equal to P * Epsilon * 1 - 2 new + + align:start position:0% +equal to P * Epsilon * 1 - 2 new + + + align:start position:0% +equal to P * Epsilon * 1 - 2 new +/ 1 - Epsilon 1 - 2 new + + align:start position:0% +/ 1 - Epsilon 1 - 2 new + + + align:start position:0% +/ 1 - Epsilon 1 - 2 new +oops two's messed + + align:start position:0% + + + + align:start position:0% + +up minus the relevant + + align:start position:0% + + + + align:start position:0% + +density and then the contribution of the + + align:start position:0% +density and then the contribution of the + + + align:start position:0% +density and then the contribution of the +gas to the the modulus you can get by + + align:start position:0% +gas to the the modulus you can get by + + + align:start position:0% +gas to the the modulus you can get by +just taking the derivative of that + + align:start position:0% +just taking the derivative of that + + + align:start position:0% +just taking the derivative of that +pressure with respect to the strain so + + align:start position:0% +pressure with respect to the strain so + + + align:start position:0% +pressure with respect to the strain so +remember modulus is stress over strain + + align:start position:0% +remember modulus is stress over strain + + + align:start position:0% +remember modulus is stress over strain +it's the same kind of + + align:start position:0% + + + + align:start position:0% + +idea so I'm going to call that e g for + + align:start position:0% +idea so I'm going to call that e g for + + + align:start position:0% +idea so I'm going to call that e g for +the contribution from the gas so that's + + align:start position:0% +the contribution from the gas so that's + + + align:start position:0% +the contribution from the gas so that's +going to equal DP Prime D + + align:start position:0% +going to equal DP Prime D + + + align:start position:0% +going to equal DP Prime D +Epsilon that's going to equal + + align:start position:0% +Epsilon that's going to equal + + + align:start position:0% +Epsilon that's going to equal +p * 1- 2 new over 1 minus the relative + + align:start position:0% + + + + align:start position:0% + +density + + align:start position:0% +density + + + align:start position:0% +density +okay so as I said I'll I'll scan the + + align:start position:0% +okay so as I said I'll I'll scan the + + + align:start position:0% +okay so as I said I'll I'll scan the +pages that have the details and put it + + align:start position:0% + + + + align:start position:0% + +online + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +so the final expression we get combines + + align:start position:0% +so the final expression we get combines + + + align:start position:0% +so the final expression we get combines +all of these things so the modulus of + + align:start position:0% +all of these things so the modulus of + + + align:start position:0% +all of these things so the modulus of +the foam relative to the + + align:start position:0% +the foam relative to the + + + align:start position:0% +the foam relative to the +solid is 5^ + + align:start position:0% + + + + align:start position:0% + +2 over Row s^ 2 plus 1us 5 that's the + + align:start position:0% +2 over Row s^ 2 plus 1us 5 that's the + + + align:start position:0% +2 over Row s^ 2 plus 1us 5 that's the +amount of material in the + + align:start position:0% +amount of material in the + + + align:start position:0% +amount of material in the +faces time the relative density and then + + align:start position:0% +faces time the relative density and then + + + align:start position:0% +faces time the relative density and then +plus this gas compression + + align:start position:0% + + + + align:start position:0% + +term + + align:start position:0% + + + + align:start position:0% + +so like I said for most Foams the gas + + align:start position:0% +so like I said for most Foams the gas + + + align:start position:0% +so like I said for most Foams the gas +compression is negligible so if if P + + align:start position:0% +compression is negligible so if if P + + + align:start position:0% +compression is negligible so if if P +KN is equal to the atmospheric + + align:start position:0% + + + + align:start position:0% + +pressure so about 0.1 megap Pascal then + + align:start position:0% +pressure so about 0.1 megap Pascal then + + + align:start position:0% +pressure so about 0.1 megap Pascal then +the gas terms negligible except for + + align:start position:0% +the gas terms negligible except for + + + align:start position:0% +the gas terms negligible except for +elastomeric foams + + align:start position:0% + + + + align:start position:0% + +so that's the young + + align:start position:0% + + + + align:start position:0% + +modulus + + align:start position:0% + + + + align:start position:0% + +and we can do a similar thing for the + + align:start position:0% +and we can do a similar thing for the + + + align:start position:0% +and we can do a similar thing for the +shear modulus and the thing to notice in + + align:start position:0% +shear modulus and the thing to notice in + + + align:start position:0% +shear modulus and the thing to notice in +Shear is that when you shear something + + align:start position:0% +Shear is that when you shear something + + + align:start position:0% +Shear is that when you shear something +there's no volume change so if you shear + + align:start position:0% +there's no volume change so if you shear + + + align:start position:0% +there's no volume change so if you shear +it and there's no volume change there's + + align:start position:0% +it and there's no volume change there's + + + align:start position:0% +it and there's no volume change there's +no gas compression there's no pressure + + align:start position:0% +no gas compression there's no pressure + + + align:start position:0% +no gas compression there's no pressure +built up because there's no change in + + align:start position:0% +built up because there's no change in + + + align:start position:0% +built up because there's no change in +the volume so for the shear modulus you + + align:start position:0% +the volume so for the shear modulus you + + + align:start position:0% +the volume so for the shear modulus you +just have the first two + + align:start position:0% + + + + align:start position:0% + +terms + + align:start position:0% + + + + align:start position:0% + +and if the foam's isotropic and use a + + align:start position:0% +and if the foam's isotropic and use a + + + align:start position:0% +and if the foam's isotropic and use a +third then this constant here is going + + align:start position:0% +third then this constant here is going + + + align:start position:0% +third then this constant here is going +to be + + align:start position:0% + + + + align:start position:0% + +38 and then plus those is just going to + + align:start position:0% +38 and then plus those is just going to + + + align:start position:0% +38 and then plus those is just going to +be a function of the cell geometry again + + align:start position:0% +be a function of the cell geometry again + + + align:start position:0% +be a function of the cell geometry again +and roughly we could say it's going to + + align:start position:0% +and roughly we could say it's going to + + + align:start position:0% +and roughly we could say it's going to +be around a + + align:start position:0% + + + + align:start position:0% + +third + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +are we good me wait a little + + align:start position:0% + + + + align:start position:0% + +bit + + align:start position:0% +bit + + + align:start position:0% +bit +so the idea is we're looking at the + + align:start position:0% +so the idea is we're looking at the + + + align:start position:0% +so the idea is we're looking at the +deformation of the bending and the cell + + align:start position:0% +deformation of the bending and the cell + + + align:start position:0% +deformation of the bending and the cell +edges and the stretching in the cell + + align:start position:0% +edges and the stretching in the cell + + + align:start position:0% +edges and the stretching in the cell +faces and the gas compression and we're + + align:start position:0% +faces and the gas compression and we're + + + align:start position:0% +faces and the gas compression and we're +accounting for those different terms so + + align:start position:0% +accounting for those different terms so + + + align:start position:0% +accounting for those different terms so +the next thing is to compare these model + + align:start position:0% +the next thing is to compare these model + + + align:start position:0% +the next thing is to compare these model +equations with um some data and here's + + align:start position:0% +equations with um some data and here's + + + align:start position:0% +equations with um some data and here's +data for Young's modulus so here we're + + align:start position:0% +data for Young's modulus so here we're + + + align:start position:0% +data for Young's modulus so here we're +plotting the relative Young's modulus so + + align:start position:0% +plotting the relative Young's modulus so + + + align:start position:0% +plotting the relative Young's modulus so +the modulus of the foam divided by the + + align:start position:0% +the modulus of the foam divided by the + + + align:start position:0% +the modulus of the foam divided by the +solid against the relative density again + + align:start position:0% +solid against the relative density again + + + align:start position:0% +solid against the relative density again +these are log log scales so on this plot + + align:start position:0% +these are log log scales so on this plot + + + align:start position:0% +these are log log scales so on this plot +everything with open symbols is an open + + align:start position:0% +everything with open symbols is an open + + + align:start position:0% +everything with open symbols is an open +cell foam and everything with filled + + align:start position:0% +cell foam and everything with filled + + + align:start position:0% +cell foam and everything with filled +symbols is a closed cell foam so here's + + align:start position:0% +symbols is a closed cell foam so here's + + + align:start position:0% +symbols is a closed cell foam so here's +our equation for the open cell Foams the + + align:start position:0% +our equation for the open cell Foams the + + + align:start position:0% +our equation for the open cell Foams the +sort of simplest thing just that goes as + + align:start position:0% +sort of simplest thing just that goes as + + + align:start position:0% +sort of simplest thing just that goes as +the density squared and that's that + + align:start position:0% +the density squared and that's that + + + align:start position:0% +the density squared and that's that +thick line there and you can see these + + align:start position:0% +thick line there and you can see these + + + align:start position:0% +thick line there and you can see these +are all open cell Foams there's some + + align:start position:0% +are all open cell Foams there's some + + + align:start position:0% +are all open cell Foams there's some +more up here and so that gives a + + align:start position:0% +more up here and so that gives a + + + align:start position:0% +more up here and so that gives a +reasonable description of that data and + + align:start position:0% +reasonable description of that data and + + + align:start position:0% +reasonable description of that data and +then these are two lines for closed cell + + align:start position:0% +then these are two lines for closed cell + + + align:start position:0% +then these are two lines for closed cell +Foams for different values of five so + + align:start position:0% +Foams for different values of five so + + + align:start position:0% +Foams for different values of five so +different values of the amount of solid + + align:start position:0% +different values of the amount of solid + + + align:start position:0% +different values of the amount of solid +in the edges and you can see all the + + align:start position:0% +in the edges and you can see all the + + + align:start position:0% +in the edges and you can see all the +filled symbols are the closed cell foam + + align:start position:0% +filled symbols are the closed cell foam + + + align:start position:0% +filled symbols are the closed cell foam +and they're in between you know this + + align:start position:0% +and they're in between you know this + + + align:start position:0% +and they're in between you know this +line here and this line here basically + + align:start position:0% +line here and this line here basically + + + align:start position:0% +line here and this line here basically +so that gives a fairly good description + + align:start position:0% +so that gives a fairly good description + + + align:start position:0% +so that gives a fairly good description +for the modulus of the Foams considering + + align:start position:0% +for the modulus of the Foams considering + + + align:start position:0% +for the modulus of the Foams considering +how kind of crude this model is we're + + align:start position:0% +how kind of crude this model is we're + + + align:start position:0% +how kind of crude this model is we're +not trying to account for the cell + + align:start position:0% +not trying to account for the cell + + + align:start position:0% +not trying to account for the cell +geometry we're just modeling the + + align:start position:0% +geometry we're just modeling the + + + align:start position:0% +geometry we're just modeling the +mechanisms of deformation and failure + + align:start position:0% +mechanisms of deformation and failure + + + align:start position:0% +mechanisms of deformation and failure +and here's a similar plot for the young + + align:start position:0% +and here's a similar plot for the young + + + align:start position:0% +and here's a similar plot for the young +mod or for the sheer + + align:start position:0% +mod or for the sheer + + + align:start position:0% +mod or for the sheer +modulus here's for open cells 38 uh + + align:start position:0% +modulus here's for open cells 38 uh + + + align:start position:0% +modulus here's for open cells 38 uh +times the relative density squared these + + align:start position:0% +times the relative density squared these + + + align:start position:0% +times the relative density squared these +are open cell Foams down here uh these + + align:start position:0% +are open cell Foams down here uh these + + + align:start position:0% +are open cell Foams down here uh these +are closed cell Foams up here um if the + + align:start position:0% +are closed cell Foams up here um if the + + + align:start position:0% +are closed cell Foams up here um if the +U amount of material in the faces is + + align:start position:0% +U amount of material in the faces is + + + align:start position:0% +U amount of material in the faces is +small then you would just get um the + + align:start position:0% +small then you would just get um the + + + align:start position:0% +small then you would just get um the +sheer modulus varying with the relative + + align:start position:0% +sheer modulus varying with the relative + + + align:start position:0% +sheer modulus varying with the relative +density squared and here's data for + + align:start position:0% +density squared and here's data for + + + align:start position:0% +density squared and here's data for +poson ratio you know we don't really + + align:start position:0% +poson ratio you know we don't really + + + align:start position:0% +poson ratio you know we don't really +know what the constant is because we + + align:start position:0% +know what the constant is because we + + + align:start position:0% +know what the constant is because we +don't know what all these geometrical + + align:start position:0% +don't know what all these geometrical + + + align:start position:0% +don't know what all these geometrical +parameters are but here's a value of a + + align:start position:0% +parameters are but here's a value of a + + + align:start position:0% +parameters are but here's a value of a +third and you can see there's a lot of + + align:start position:0% +third and you can see there's a lot of + + + align:start position:0% +third and you can see there's a lot of +scatter here this you know this is like + + align:start position:0% +scatter here this you know this is like + + + align:start position:0% +scatter here this you know this is like +less than 02 this is more + + align:start position:0% +less than 02 this is more + + + align:start position:0% +less than 02 this is more +than5 um and the scatter really + + align:start position:0% +than5 um and the scatter really + + + align:start position:0% +than5 um and the scatter really +represents differences in the cell G + + align:start position:0% +represents differences in the cell G + + + align:start position:0% +represents differences in the cell G +ometry so if the Foams were say + + align:start position:0% +ometry so if the Foams were say + + + align:start position:0% +ometry so if the Foams were say +anisotropic and they had the the cells + + align:start position:0% +anisotropic and they had the the cells + + + align:start position:0% +anisotropic and they had the the cells +were stretched in One Direction then you + + align:start position:0% +were stretched in One Direction then you + + + align:start position:0% +were stretched in One Direction then you +would get different values of the pel's + + align:start position:0% +would get different values of the pel's + + + align:start position:0% +would get different values of the pel's +ratios so that's the pum ratios there so + + align:start position:0% +ratios so that's the pum ratios there so + + + align:start position:0% +ratios so that's the pum ratios there so +I'm thinking I'm going to stop there + + align:start position:0% +I'm thinking I'm going to stop there + + + align:start position:0% +I'm thinking I'm going to stop there +because that seems like enough equations + + align:start position:0% +because that seems like enough equations + + + align:start position:0% +because that seems like enough equations +for today and then next time uh we'll + + align:start position:0% +for today and then next time uh we'll + + + align:start position:0% +for today and then next time uh we'll +start doing the stress plateau and we'll + + align:start position:0% +start doing the stress plateau and we'll + + + align:start position:0% +start doing the stress plateau and we'll +figure out an elastic collapse stress + + align:start position:0% +figure out an elastic collapse stress + + + align:start position:0% +figure out an elastic collapse stress +from buckling and a plastic collap stps + + align:start position:0% +from buckling and a plastic collap stps + + + align:start position:0% +from buckling and a plastic collap stps +from yielding and so on and so on so + + align:start position:0% +from yielding and so on and so on so + + + align:start position:0% +from yielding and so on and so on so +we'll finish doing the modeling um next + + align:start position:0% +we'll finish doing the modeling um next + + + align:start position:0% +we'll finish doing the modeling um next +time and we'll probably start doing a + + align:start position:0% +time and we'll probably start doing a + + + align:start position:0% +time and we'll probably start doing a +little bit of other stuff on Foams next + + align:start position:0% + + + + align:start position:0% + +time \ No newline at end of file diff --git a/5YyUArlg8Sg.txt b/5YyUArlg8Sg.txt new file mode 100644 index 0000000000000000000000000000000000000000..7bd5ec1563c0be3fe1feaacb3bef7994052e0da1 --- /dev/null +++ b/5YyUArlg8Sg.txt @@ -0,0 +1,9531 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a creative commons license + + align:start position:0% +a creative commons license + + + align:start position:0% +a creative commons license +your support will help mit + + align:start position:0% +your support will help mit + + + align:start position:0% +your support will help mit +opencourseware continue to offer + + align:start position:0% +opencourseware continue to offer + + + align:start position:0% +opencourseware continue to offer +high quality educational resources for + + align:start position:0% +high quality educational resources for + + + align:start position:0% +high quality educational resources for +free + + align:start position:0% +free + + + align:start position:0% +free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of mit courses + + align:start position:0% +materials from hundreds of mit courses + + + align:start position:0% +materials from hundreds of mit courses +visit mit opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so we're going to continue talking about + + align:start position:0% +so we're going to continue talking about + + + align:start position:0% +so we're going to continue talking about +coding we're going to focus on + + align:start position:0% +coding we're going to focus on + + + align:start position:0% +coding we're going to focus on +linear block codes which i introduced + + align:start position:0% +linear block codes which i introduced + + + align:start position:0% +linear block codes which i introduced +briefly last time + + align:start position:0% +briefly last time + + + align:start position:0% +briefly last time +but just to step back a bit and remind + + align:start position:0% +but just to step back a bit and remind + + + align:start position:0% +but just to step back a bit and remind +you we're talking about + + align:start position:0% +you we're talking about + + + align:start position:0% +you we're talking about +this piece of the overall channel so + + align:start position:0% +this piece of the overall channel so + + + align:start position:0% +this piece of the overall channel so +we've got the source that's done the + + align:start position:0% +we've got the source that's done the + + + align:start position:0% +we've got the source that's done the +source coding uh compressing all the + + align:start position:0% +source coding uh compressing all the + + + align:start position:0% +source coding uh compressing all the +bits coming out of here so that one bit + + align:start position:0% +bits coming out of here so that one bit + + + align:start position:0% +bits coming out of here so that one bit +one binary digit carries a bit of + + align:start position:0% +one binary digit carries a bit of + + + align:start position:0% +one binary digit carries a bit of +information + + align:start position:0% +information + + + align:start position:0% +information +and now we're actually reintroducing + + align:start position:0% +and now we're actually reintroducing + + + align:start position:0% +and now we're actually reintroducing +redundancy in a controlled way so that + + align:start position:0% +redundancy in a controlled way so that + + + align:start position:0% +redundancy in a controlled way so that +we can + + align:start position:0% +we can + + + align:start position:0% +we can +protect the message across the physical + + align:start position:0% +protect the message across the physical + + + align:start position:0% +protect the message across the physical +channel + + align:start position:0% +channel + + + align:start position:0% +channel +with its noise sources and distortions + + align:start position:0% +with its noise sources and distortions + + + align:start position:0% +with its noise sources and distortions +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +um actually i should be saying binary + + align:start position:0% +um actually i should be saying binary + + + align:start position:0% +um actually i should be saying binary +digits at this point because again at + + align:start position:0% +digits at this point because again at + + + align:start position:0% +digits at this point because again at +this point the binary digit doesn't + + align:start position:0% +this point the binary digit doesn't + + + align:start position:0% +this point the binary digit doesn't +carry + + align:start position:0% +carry + + + align:start position:0% +carry +a bit of information uh we're + + align:start position:0% +a bit of information uh we're + + + align:start position:0% +a bit of information uh we're +introducing redundancy but + + align:start position:0% +introducing redundancy but + + + align:start position:0% +introducing redundancy but +i'll leave you now to make the + + align:start position:0% +i'll leave you now to make the + + + align:start position:0% +i'll leave you now to make the +distinctions okay at this point here + + align:start position:0% +distinctions okay at this point here + + + align:start position:0% +distinctions okay at this point here +outside the source coding one binary + + align:start position:0% +outside the source coding one binary + + + align:start position:0% +outside the source coding one binary +digit is one bit of information + + align:start position:0% +digit is one bit of information + + + align:start position:0% +digit is one bit of information +but now when you start to introduce the + + align:start position:0% +but now when you start to introduce the + + + align:start position:0% +but now when you start to introduce the +redundancy you've got binary digits that + + align:start position:0% +redundancy you've got binary digits that + + + align:start position:0% +redundancy you've got binary digits that +are not necessarily one bit of + + align:start position:0% +are not necessarily one bit of + + + align:start position:0% +are not necessarily one bit of +information + + align:start position:0% +information + + + align:start position:0% +information +per binary digit in fact it won't be and + + align:start position:0% +per binary digit in fact it won't be and + + + align:start position:0% +per binary digit in fact it won't be and +then across the channel at the other end + + align:start position:0% +then across the channel at the other end + + + align:start position:0% +then across the channel at the other end +you do the uh + + align:start position:0% +you do the uh + + + align:start position:0% +you do the uh +decoding to try and recover from any + + align:start position:0% +decoding to try and recover from any + + + align:start position:0% +decoding to try and recover from any +errors that the channel might have + + align:start position:0% +errors that the channel might have + + + align:start position:0% +errors that the channel might have +encountered + + align:start position:0% +encountered + + + align:start position:0% +encountered +and what we said last time is that the + + align:start position:0% +and what we said last time is that the + + + align:start position:0% +and what we said last time is that the +key to this + + align:start position:0% +key to this + + + align:start position:0% +key to this +is really to introduce + + align:start position:0% +is really to introduce + + + align:start position:0% +is really to introduce +some space around the code words that + + align:start position:0% +some space around the code words that + + + align:start position:0% +some space around the code words that +carry your messages so + + align:start position:0% +carry your messages so + + + align:start position:0% +carry your messages so +you might want to expand + + align:start position:0% +you might want to expand + + + align:start position:0% +you might want to expand +your set of messages into a longer code + + align:start position:0% +your set of messages into a longer code + + + align:start position:0% +your set of messages into a longer code +word such that + + align:start position:0% +word such that + + + align:start position:0% +word such that +a small number of errors on each code + + align:start position:0% +a small number of errors on each code + + + align:start position:0% +a small number of errors on each code +word will not flip you over into another + + align:start position:0% +word will not flip you over into another + + + align:start position:0% +word will not flip you over into another +code word so you'll be able to recognize + + align:start position:0% +code word so you'll be able to recognize + + + align:start position:0% +code word so you'll be able to recognize +the neighborhood of + + align:start position:0% +the neighborhood of + + + align:start position:0% +the neighborhood of +the valid code words that's the basic + + align:start position:0% +the valid code words that's the basic + + + align:start position:0% +the valid code words that's the basic +idea so you're trying to + + align:start position:0% +idea so you're trying to + + + align:start position:0% +idea so you're trying to +put some space around things + + align:start position:0% + + + + align:start position:0% + +so if you've got k + + align:start position:0% +so if you've got k + + + align:start position:0% +so if you've got k +bits in your original message so you've + + align:start position:0% +bits in your original message so you've + + + align:start position:0% +bits in your original message so you've +got two to the k messages + + align:start position:0% +got two to the k messages + + + align:start position:0% +got two to the k messages +right so k message bits + + align:start position:0% + + + + align:start position:0% + +uh two to the k messages + + align:start position:0% + + + + align:start position:0% + +and what we're planning to do now is uh + + align:start position:0% +and what we're planning to do now is uh + + + align:start position:0% +and what we're planning to do now is uh +with this input stream that's coming + + align:start position:0% +with this input stream that's coming + + + align:start position:0% +with this input stream that's coming +into our channel coder + + align:start position:0% + + + + align:start position:0% + +we're going to take the stream and break + + align:start position:0% +we're going to take the stream and break + + + align:start position:0% +we're going to take the stream and break +it + + align:start position:0% +it + + + align:start position:0% +it +up into blocks so each block will have + + align:start position:0% +up into blocks so each block will have + + + align:start position:0% +up into blocks so each block will have +k message bits + + align:start position:0% + + + + align:start position:0% + +and then out come a series of blocks but + + align:start position:0% +and then out come a series of blocks but + + + align:start position:0% +and then out come a series of blocks but +each block now has a larger number so + + align:start position:0% +each block now has a larger number so + + + align:start position:0% +each block now has a larger number so +we've got + + align:start position:0% +we've got + + + align:start position:0% +we've got +n bits + + align:start position:0% +n bits + + + align:start position:0% +n bits +okay so we've done some padding here n + + align:start position:0% +okay so we've done some padding here n + + + align:start position:0% +okay so we've done some padding here n +is greater than k + + align:start position:0% +is greater than k + + + align:start position:0% +is greater than k +and so you have the possibility of + + align:start position:0% +and so you have the possibility of + + + align:start position:0% +and so you have the possibility of +two to the n possible messages in those + + align:start position:0% +two to the n possible messages in those + + + align:start position:0% +two to the n possible messages in those +n bits but you're not going to use all + + align:start position:0% +n bits but you're not going to use all + + + align:start position:0% +n bits but you're not going to use all +of them + + align:start position:0% +of them + + + align:start position:0% +of them +you're only going to use two to the k + + align:start position:0% +you're only going to use two to the k + + + align:start position:0% +you're only going to use two to the k +and so you'll leave some space around + + align:start position:0% +and so you'll leave some space around + + + align:start position:0% +and so you'll leave some space around +each valid code word + + align:start position:0% +each valid code word + + + align:start position:0% +each valid code word +all right so this is how the uh so the + + align:start position:0% +all right so this is how the uh so the + + + align:start position:0% +all right so this is how the uh so the +code words are selected from + + align:start position:0% +code words are selected from + + + align:start position:0% +code words are selected from +two to the k code words + + align:start position:0% +two to the k code words + + + align:start position:0% +two to the k code words +selected from + + align:start position:0% + + + + align:start position:0% + +two to the end possibilities + + align:start position:0% + + + + align:start position:0% + +okay you get the idea there yeah + + align:start position:0% +okay you get the idea there yeah + + + align:start position:0% +okay you get the idea there yeah +and we introduced this notion of hamming + + align:start position:0% +and we introduced this notion of hamming + + + align:start position:0% +and we introduced this notion of hamming +distance then + + align:start position:0% +distance then + + + align:start position:0% +distance then +um to measure + + align:start position:0% +um to measure + + + align:start position:0% +um to measure +the size of the neighborhood around the + + align:start position:0% +the size of the neighborhood around the + + + align:start position:0% +the size of the neighborhood around the +code word so + + align:start position:0% +code word so + + + align:start position:0% +code word so +we have the notion of a hamming distance + + align:start position:0% + + + + align:start position:0% + +which will abbreviate to hd and this is + + align:start position:0% +which will abbreviate to hd and this is + + + align:start position:0% +which will abbreviate to hd and this is +the + + align:start position:0% +the + + + align:start position:0% +the +this is the hamming distance between two + + align:start position:0% +this is the hamming distance between two + + + align:start position:0% +this is the hamming distance between two +bit streams or between two + + align:start position:0% + + + + align:start position:0% + +let's say blocks and what this is is the + + align:start position:0% +let's say blocks and what this is is the + + + align:start position:0% +let's say blocks and what this is is the +number of + + align:start position:0% +number of + + + align:start position:0% +number of +positions in which they differ + + align:start position:0% + + + + align:start position:0% + +okay so it's a very um + + align:start position:0% +okay so it's a very um + + + align:start position:0% +okay so it's a very um +simple notion of distance between + + align:start position:0% +simple notion of distance between + + + align:start position:0% +simple notion of distance between +bit strings or binary digit strings + + align:start position:0% +bit strings or binary digit strings + + + align:start position:0% +bit strings or binary digit strings +all right + + align:start position:0% +all right + + + align:start position:0% +all right +and what we then said is you get certain + + align:start position:0% +and what we then said is you get certain + + + align:start position:0% +and what we then said is you get certain +desirable + + align:start position:0% +desirable + + + align:start position:0% +desirable +error detection and error correction + + align:start position:0% +error detection and error correction + + + align:start position:0% +error detection and error correction +properties um + + align:start position:0% +properties um + + + align:start position:0% +properties um +based on the minimum distance the + + align:start position:0% +based on the minimum distance the + + + align:start position:0% +based on the minimum distance the +minimum + + align:start position:0% +minimum + + + align:start position:0% +minimum +hamming distance + + align:start position:0% +hamming distance + + + align:start position:0% +hamming distance +of a code um + + align:start position:0% +of a code um + + + align:start position:0% +of a code um +we use the symbol little d for that + + align:start position:0% +we use the symbol little d for that + + + align:start position:0% +we use the symbol little d for that +that's the minimum distance you find + + align:start position:0% +that's the minimum distance you find + + + align:start position:0% +that's the minimum distance you find +between any two code words + + align:start position:0% +between any two code words + + + align:start position:0% +between any two code words +in the code all right so based on that + + align:start position:0% +in the code all right so based on that + + + align:start position:0% +in the code all right so based on that +we said that + + align:start position:0% +we said that + + + align:start position:0% +we said that +we wrote it slightly differently last + + align:start position:0% +we wrote it slightly differently last + + + align:start position:0% +we wrote it slightly differently last +time i'm writing it to give you yet + + align:start position:0% +time i'm writing it to give you yet + + + align:start position:0% +time i'm writing it to give you yet +another way to think about it + + align:start position:0% +another way to think about it + + + align:start position:0% +another way to think about it +what we basically said is for instance + + align:start position:0% + + + + align:start position:0% + +uh if you had valid code word here valid + + align:start position:0% +uh if you had valid code word here valid + + + align:start position:0% +uh if you had valid code word here valid +code word here + + align:start position:0% +code word here + + + align:start position:0% +code word here +this is just a schematic right one hop + + align:start position:0% +this is just a schematic right one hop + + + align:start position:0% +this is just a schematic right one hop +meaning one bit change brings you to + + align:start position:0% +meaning one bit change brings you to + + + align:start position:0% +meaning one bit change brings you to +some other word + + align:start position:0% +some other word + + + align:start position:0% +some other word +which is not a code word then another + + align:start position:0% +which is not a code word then another + + + align:start position:0% +which is not a code word then another +bit change brings you to some other word + + align:start position:0% +bit change brings you to some other word + + + align:start position:0% +bit change brings you to some other word +not a code word + + align:start position:0% +not a code word + + + align:start position:0% +not a code word +and a further one brings you to a new + + align:start position:0% +and a further one brings you to a new + + + align:start position:0% +and a further one brings you to a new +code word that's hamming distance three + + align:start position:0% +code word that's hamming distance three + + + align:start position:0% +code word that's hamming distance three +so if the minimum distance you find + + align:start position:0% +so if the minimum distance you find + + + align:start position:0% +so if the minimum distance you find +among all the + + align:start position:0% +among all the + + + align:start position:0% +among all the +spacings between code words is a + + align:start position:0% +spacings between code words is a + + + align:start position:0% +spacings between code words is a +distance of three + + align:start position:0% +distance of three + + + align:start position:0% +distance of three +measured as a hamming distance then you + + align:start position:0% +measured as a hamming distance then you + + + align:start position:0% +measured as a hamming distance then you +can detect up to two errors + + align:start position:0% +can detect up to two errors + + + align:start position:0% +can detect up to two errors +right so if you went from this code word + + align:start position:0% +right so if you went from this code word + + + align:start position:0% +right so if you went from this code word +um in two hops you'd still not be at a + + align:start position:0% +um in two hops you'd still not be at a + + + align:start position:0% +um in two hops you'd still not be at a +new code word so you know you've made a + + align:start position:0% +new code word so you know you've made a + + + align:start position:0% +new code word so you know you've made a +mistake + + align:start position:0% +mistake + + + align:start position:0% +mistake +if you wanted to correct errors you + + align:start position:0% +if you wanted to correct errors you + + + align:start position:0% +if you wanted to correct errors you +could correct up to + + align:start position:0% +could correct up to + + + align:start position:0% +could correct up to +one error in this case if you assuming + + align:start position:0% +one error in this case if you assuming + + + align:start position:0% +one error in this case if you assuming +that you have no more than one error + + align:start position:0% +that you have no more than one error + + + align:start position:0% +that you have no more than one error +if you ended up here you'd know it had + + align:start position:0% +if you ended up here you'd know it had + + + align:start position:0% +if you ended up here you'd know it had +to have come from this code word + + align:start position:0% +to have come from this code word + + + align:start position:0% +to have come from this code word +if you ended up here you know it had to + + align:start position:0% +if you ended up here you know it had to + + + align:start position:0% +if you ended up here you know it had to +have come from the code word on the + + align:start position:0% +have come from the code word on the + + + align:start position:0% +have come from the code word on the +right + + align:start position:0% +right + + + align:start position:0% +right +now you have to be a little careful if + + align:start position:0% +now you have to be a little careful if + + + align:start position:0% +now you have to be a little careful if +you're trying to do correction and + + align:start position:0% +you're trying to do correction and + + + align:start position:0% +you're trying to do correction and +detection at the same time + + align:start position:0% +detection at the same time + + + align:start position:0% +detection at the same time +so for instance if you end up over here + + align:start position:0% +so for instance if you end up over here + + + align:start position:0% +so for instance if you end up over here +and if it's possible to get up to two + + align:start position:0% +and if it's possible to get up to two + + + align:start position:0% +and if it's possible to get up to two +errors then + + align:start position:0% +errors then + + + align:start position:0% +errors then +you might think you've had one error + + align:start position:0% +you might think you've had one error + + + align:start position:0% +you might think you've had one error +that brought you here and you might + + align:start position:0% +that brought you here and you might + + + align:start position:0% +that brought you here and you might +correct to this point + + align:start position:0% +correct to this point + + + align:start position:0% +correct to this point +but if what you actually the way you + + align:start position:0% +but if what you actually the way you + + + align:start position:0% +but if what you actually the way you +actually got there was two hops from + + align:start position:0% +actually got there was two hops from + + + align:start position:0% +actually got there was two hops from +over here then you've done + + align:start position:0% +over here then you've done + + + align:start position:0% +over here then you've done +an incorrect correction okay so you've + + align:start position:0% +an incorrect correction okay so you've + + + align:start position:0% +an incorrect correction okay so you've +got to be a little bit careful + + align:start position:0% +got to be a little bit careful + + + align:start position:0% +got to be a little bit careful +and that's what the uh third case tries + + align:start position:0% +and that's what the uh third case tries + + + align:start position:0% +and that's what the uh third case tries +to deal with it allows you to uh + + align:start position:0% +to deal with it allows you to uh + + + align:start position:0% +to deal with it allows you to uh +deal with combinations of correcting up + + align:start position:0% +deal with combinations of correcting up + + + align:start position:0% +deal with combinations of correcting up +to a certain number of errors + + align:start position:0% +to a certain number of errors + + + align:start position:0% +to a certain number of errors +and then detecting a certain number so + + align:start position:0% +and then detecting a certain number so + + + align:start position:0% +and then detecting a certain number so +basically + + align:start position:0% +basically + + + align:start position:0% +basically +what it's saying is that this entire + + align:start position:0% +what it's saying is that this entire + + + align:start position:0% +what it's saying is that this entire +distance here + + align:start position:0% +distance here + + + align:start position:0% +distance here +has to end up with a little gap you've + + align:start position:0% +has to end up with a little gap you've + + + align:start position:0% +has to end up with a little gap you've +got to have + + align:start position:0% + + + + align:start position:0% + +you've got to be able to make a number + + align:start position:0% +you've got to be able to make a number + + + align:start position:0% +you've got to be able to make a number +of hops equal to + + align:start position:0% +of hops equal to + + + align:start position:0% +of hops equal to +the number of errors you want to detect + + align:start position:0% +the number of errors you want to detect + + + align:start position:0% +the number of errors you want to detect +and still leave enough space + + align:start position:0% +and still leave enough space + + + align:start position:0% +and still leave enough space +to get to a code word unambiguously so + + align:start position:0% +to get to a code word unambiguously so + + + align:start position:0% +to get to a code word unambiguously so +in this particular case for instance + + align:start position:0% +in this particular case for instance + + + align:start position:0% +in this particular case for instance +you couldn't unambiguously detect up to + + align:start position:0% +you couldn't unambiguously detect up to + + + align:start position:0% +you couldn't unambiguously detect up to +two errors if you were doing + + align:start position:0% +two errors if you were doing + + + align:start position:0% +two errors if you were doing +error correction for one but if i had + + align:start position:0% +error correction for one but if i had + + + align:start position:0% +error correction for one but if i had +this picture + + align:start position:0% + + + + align:start position:0% + +okay this is not hamming distance four + + align:start position:0% +okay this is not hamming distance four + + + align:start position:0% +okay this is not hamming distance four +one two + + align:start position:0% +one two + + + align:start position:0% +one two +three four i could correct + + align:start position:0% +three four i could correct + + + align:start position:0% +three four i could correct +single bit errors and i could detect up + + align:start position:0% +single bit errors and i could detect up + + + align:start position:0% +single bit errors and i could detect up +to two because + + align:start position:0% +to two because + + + align:start position:0% +to two because +two errors would bring me up to this + + align:start position:0% +two errors would bring me up to this + + + align:start position:0% +two errors would bring me up to this +point and that's clearly an error that i + + align:start position:0% +point and that's clearly an error that i + + + align:start position:0% +point and that's clearly an error that i +wouldn't try to correct but i'd + + align:start position:0% +wouldn't try to correct but i'd + + + align:start position:0% +wouldn't try to correct but i'd +recognize it as an error + + align:start position:0% +recognize it as an error + + + align:start position:0% +recognize it as an error +okay so that's what the third case tries + + align:start position:0% +okay so that's what the third case tries + + + align:start position:0% +okay so that's what the third case tries +to account for + + align:start position:0% +to account for + + + align:start position:0% +to account for +you won't believe how much time i spend + + align:start position:0% +you won't believe how much time i spend + + + align:start position:0% +you won't believe how much time i spend +trying to distill that statement down + + align:start position:0% +trying to distill that statement down + + + align:start position:0% +trying to distill that statement down +into a bullet and i don't know if i got + + align:start position:0% +into a bullet and i don't know if i got + + + align:start position:0% +into a bullet and i don't know if i got +it right yet but + + align:start position:0% +it right yet but + + + align:start position:0% +it right yet but +that's the idea okay so our focus + + align:start position:0% +that's the idea okay so our focus + + + align:start position:0% +that's the idea okay so our focus +today is on linear block codes we're not + + align:start position:0% +today is on linear block codes we're not + + + align:start position:0% +today is on linear block codes we're not +talking about codes in general but + + align:start position:0% +talking about codes in general but + + + align:start position:0% +talking about codes in general but +linear codes + + align:start position:0% + + + + align:start position:0% + +this would be a general statement for a + + align:start position:0% +this would be a general statement for a + + + align:start position:0% +this would be a general statement for a +block code i haven't said anything about + + align:start position:0% +block code i haven't said anything about + + + align:start position:0% +block code i haven't said anything about +linearity up to this point all i said + + align:start position:0% +linearity up to this point all i said + + + align:start position:0% +linearity up to this point all i said +was + + align:start position:0% +was + + + align:start position:0% +was +take blocks of k bits expand them to + + align:start position:0% +take blocks of k bits expand them to + + + align:start position:0% +take blocks of k bits expand them to +blocks of n bits and pick + + align:start position:0% +blocks of n bits and pick + + + align:start position:0% +blocks of n bits and pick +uh subsets in this fashion that's just a + + align:start position:0% +uh subsets in this fashion that's just a + + + align:start position:0% +uh subsets in this fashion that's just a +general statement about + + align:start position:0% +general statement about + + + align:start position:0% +general statement about +coding there's nothing linear about this + + align:start position:0% +coding there's nothing linear about this + + + align:start position:0% +coding there's nothing linear about this +as stated + + align:start position:0% +as stated + + + align:start position:0% +as stated +so if you want to impose linearity then + + align:start position:0% +so if you want to impose linearity then + + + align:start position:0% +so if you want to impose linearity then +you've got to + + align:start position:0% +you've got to + + + align:start position:0% +you've got to +introduce this additional piece which is + + align:start position:0% +introduce this additional piece which is + + + align:start position:0% +introduce this additional piece which is +to say that + + align:start position:0% +to say that + + + align:start position:0% +to say that +every bit in your code word is going to + + align:start position:0% +every bit in your code word is going to + + + align:start position:0% +every bit in your code word is going to +be a + + align:start position:0% +be a + + + align:start position:0% +be a +linear combination of bits from your + + align:start position:0% +linear combination of bits from your + + + align:start position:0% +linear combination of bits from your +message + + align:start position:0% +message + + + align:start position:0% +message +and the easiest way to understand that + + align:start position:0% +and the easiest way to understand that + + + align:start position:0% +and the easiest way to understand that +is the uh + + align:start position:0% +is the uh + + + align:start position:0% +is the uh +the matrix representation i had last + + align:start position:0% +the matrix representation i had last + + + align:start position:0% +the matrix representation i had last +time + + align:start position:0% + + + + align:start position:0% + +do i have it on this slide not yet okay + + align:start position:0% +do i have it on this slide not yet okay + + + align:start position:0% +do i have it on this slide not yet okay +but i probably do on the next so let me + + align:start position:0% +but i probably do on the next so let me + + + align:start position:0% +but i probably do on the next so let me +put that up + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +okay so basically you're going to + + align:start position:0% +okay so basically you're going to + + + align:start position:0% +okay so basically you're going to +generate your code words + + align:start position:0% +generate your code words + + + align:start position:0% +generate your code words +c so that's uh + + align:start position:0% + + + + align:start position:0% + +c1 up to cn is going to be + + align:start position:0% +c1 up to cn is going to be + + + align:start position:0% +c1 up to cn is going to be +d1 up to dk + + align:start position:0% + + + + align:start position:0% + +times some matrix which is uh + + align:start position:0% +times some matrix which is uh + + + align:start position:0% +times some matrix which is uh +k times n matrix and we'll call it g + + align:start position:0% +k times n matrix and we'll call it g + + + align:start position:0% +k times n matrix and we'll call it g +okay so that's referred to as the + + align:start position:0% +okay so that's referred to as the + + + align:start position:0% +okay so that's referred to as the +generator matrix for the code + + align:start position:0% + + + + align:start position:0% + +we're talking about binary code so this + + align:start position:0% +we're talking about binary code so this + + + align:start position:0% +we're talking about binary code so this +is all of these are zeros or ones + + align:start position:0% +is all of these are zeros or ones + + + align:start position:0% +is all of these are zeros or ones +and all of these entries are zero or one + + align:start position:0% +and all of these entries are zero or one + + + align:start position:0% +and all of these entries are zero or one +and all computations are done in gf2 + + align:start position:0% +and all computations are done in gf2 + + + align:start position:0% +and all computations are done in gf2 +they're done modulo two so + + align:start position:0% + + + + align:start position:0% + +matrix multi well let me just say that + + align:start position:0% +matrix multi well let me just say that + + + align:start position:0% +matrix multi well let me just say that +all operations + + align:start position:0% +all operations + + + align:start position:0% +all operations +are in gf2 + + align:start position:0% + + + + align:start position:0% + +okay so this is modulo 2 operations or + + align:start position:0% +okay so this is modulo 2 operations or + + + align:start position:0% +okay so this is modulo 2 operations or +boolean operations + + align:start position:0% + + + + align:start position:0% + +so if i'm working with the symbols zero + + align:start position:0% +so if i'm working with the symbols zero + + + align:start position:0% +so if i'm working with the symbols zero +and one what is zero minus one + + align:start position:0% + + + + align:start position:0% + +how am i to interpret this i haven't + + align:start position:0% +how am i to interpret this i haven't + + + align:start position:0% +how am i to interpret this i haven't +quite defined it but how would you + + align:start position:0% +quite defined it but how would you + + + align:start position:0% +quite defined it but how would you +interpret that + + align:start position:0% + + + + align:start position:0% + +you can think of it as the thing i need + + align:start position:0% +you can think of it as the thing i need + + + align:start position:0% +you can think of it as the thing i need +on the right hand side that when i add + + align:start position:0% +on the right hand side that when i add + + + align:start position:0% +on the right hand side that when i add +one to both sides i get zero is that one + + align:start position:0% +one to both sides i get zero is that one + + + align:start position:0% +one to both sides i get zero is that one +way to think of it + + align:start position:0% +way to think of it + + + align:start position:0% +way to think of it +so zero minus one is one or another way + + align:start position:0% +so zero minus one is one or another way + + + align:start position:0% +so zero minus one is one or another way +to say that is minus one is the same as + + align:start position:0% +to say that is minus one is the same as + + + align:start position:0% +to say that is minus one is the same as +plus one in this + + align:start position:0% +plus one in this + + + align:start position:0% +plus one in this +setting okay + + align:start position:0% +setting okay + + + align:start position:0% +setting okay +okay so you just have to get used to + + align:start position:0% +okay so you just have to get used to + + + align:start position:0% +okay so you just have to get used to +working with only zero and one + + align:start position:0% +working with only zero and one + + + align:start position:0% +working with only zero and one +in gf2 but we talked about that last + + align:start position:0% +in gf2 but we talked about that last + + + align:start position:0% +in gf2 but we talked about that last +time + + align:start position:0% +time + + + align:start position:0% +time +all right so back to the statement this + + align:start position:0% +all right so back to the statement this + + + align:start position:0% +all right so back to the statement this +is for a linear block code + + align:start position:0% + + + + align:start position:0% + +you're going to see matrix + + align:start position:0% +you're going to see matrix + + + align:start position:0% +you're going to see matrix +multiplication throughout + + align:start position:0% +multiplication throughout + + + align:start position:0% +multiplication throughout +your careers here so if you haven't + + align:start position:0% +your careers here so if you haven't + + + align:start position:0% +your careers here so if you haven't +already seen them this is a good + + align:start position:0% +already seen them this is a good + + + align:start position:0% +already seen them this is a good +opportunity to + + align:start position:0% +opportunity to + + + align:start position:0% +opportunity to +learn about matrix multiplications so + + align:start position:0% +learn about matrix multiplications so + + + align:start position:0% +learn about matrix multiplications so +let's see could somebody tell me what + + align:start position:0% +let's see could somebody tell me what + + + align:start position:0% +let's see could somebody tell me what +procedure i go through to + + align:start position:0% +procedure i go through to + + + align:start position:0% +procedure i go through to +let's say get the eighth + + align:start position:0% +let's say get the eighth + + + align:start position:0% +let's say get the eighth +position here in terms of what i do on + + align:start position:0% +position here in terms of what i do on + + + align:start position:0% +position here in terms of what i do on +the + + align:start position:0% +the + + + align:start position:0% +the +right hand side if i want to get the i + + align:start position:0% +right hand side if i want to get the i + + + align:start position:0% +right hand side if i want to get the i +position + + align:start position:0% +position + + + align:start position:0% +position +on the left hand side what's the + + align:start position:0% +on the left hand side what's the + + + align:start position:0% +on the left hand side what's the +operation that i'm thinking of + + align:start position:0% + + + + align:start position:0% + +or let me ask you this is the entire + + align:start position:0% +or let me ask you this is the entire + + + align:start position:0% +or let me ask you this is the entire +matrix g + + align:start position:0% +matrix g + + + align:start position:0% +matrix g +relevant when i'm just interested in the + + align:start position:0% +relevant when i'm just interested in the + + + align:start position:0% +relevant when i'm just interested in the +eighth position here + + align:start position:0% + + + + align:start position:0% + +or is there some part of g that's what i + + align:start position:0% +or is there some part of g that's what i + + + align:start position:0% +or is there some part of g that's what i +should focus on + + align:start position:0% +should focus on + + + align:start position:0% +should focus on +yeah it's just the eighth column right + + align:start position:0% +yeah it's just the eighth column right + + + align:start position:0% +yeah it's just the eighth column right +so we think of matrix multiplication as + + align:start position:0% +so we think of matrix multiplication as + + + align:start position:0% +so we think of matrix multiplication as +sort of being + + align:start position:0% +sort of being + + + align:start position:0% +sort of being +in this uh in the simple case + + align:start position:0% +in this uh in the simple case + + + align:start position:0% +in this uh in the simple case +if you want the i position here it's + + align:start position:0% +if you want the i position here it's + + + align:start position:0% +if you want the i position here it's +kind of the dot product + + align:start position:0% +kind of the dot product + + + align:start position:0% +kind of the dot product +of this row with the ith column + + align:start position:0% +of this row with the ith column + + + align:start position:0% +of this row with the ith column +okay so if you want the eighth position + + align:start position:0% +okay so if you want the eighth position + + + align:start position:0% +okay so if you want the eighth position +here let me give you a particular + + align:start position:0% +here let me give you a particular + + + align:start position:0% +here let me give you a particular +example + + align:start position:0% + + + + align:start position:0% + +if i've got 1 0 1 1 here and i have + + align:start position:0% +if i've got 1 0 1 1 here and i have + + + align:start position:0% +if i've got 1 0 1 1 here and i have +one one zero zero here then this + + align:start position:0% +one one zero zero here then this + + + align:start position:0% +one one zero zero here then this +position is going to be + + align:start position:0% +position is going to be + + + align:start position:0% +position is going to be +this is in the eighth column + + align:start position:0% + + + + align:start position:0% + +what i'm going to find in the eighth + + align:start position:0% +what i'm going to find in the eighth + + + align:start position:0% +what i'm going to find in the eighth +column is one times one which is one + + align:start position:0% +column is one times one which is one + + + align:start position:0% +column is one times one which is one +plus zero times one which is zero plus + + align:start position:0% +plus zero times one which is zero plus + + + align:start position:0% +plus zero times one which is zero plus +one times zero plus one times zero so i + + align:start position:0% +one times zero plus one times zero so i + + + align:start position:0% +one times zero plus one times zero so i +just get a one + + align:start position:0% + + + + align:start position:0% + +right so i'm just going to get + + align:start position:0% +right so i'm just going to get + + + align:start position:0% +right so i'm just going to get +a one or a zero depending on the + + align:start position:0% +a one or a zero depending on the + + + align:start position:0% +a one or a zero depending on the +specific entries here + + align:start position:0% + + + + align:start position:0% + +so look what we've done we've found a + + align:start position:0% +so look what we've done we've found a + + + align:start position:0% +so look what we've done we've found a +particular position in the code word + + align:start position:0% +particular position in the code word + + + align:start position:0% +particular position in the code word +as a linear combination of + + align:start position:0% +as a linear combination of + + + align:start position:0% +as a linear combination of +the bits in the message we took a + + align:start position:0% +the bits in the message we took a + + + align:start position:0% +the bits in the message we took a +combination of these bits with the + + align:start position:0% +combination of these bits with the + + + align:start position:0% +combination of these bits with the +weights that are displayed out here + + align:start position:0% +weights that are displayed out here + + + align:start position:0% +weights that are displayed out here +so that's really what this uh + + align:start position:0% +so that's really what this uh + + + align:start position:0% +so that's really what this uh +statement was on the previous slide we + + align:start position:0% +statement was on the previous slide we + + + align:start position:0% +statement was on the previous slide we +said that code is linear + + align:start position:0% + + + + align:start position:0% + +um well + + align:start position:0% +um well + + + align:start position:0% +um well +each of the k message bits is encoded as + + align:start position:0% +each of the k message bits is encoded as + + + align:start position:0% +each of the k message bits is encoded as +a linear transformation + + align:start position:0% +a linear transformation + + + align:start position:0% +a linear transformation +uh sorry each of the code bits is + + align:start position:0% +uh sorry each of the code bits is + + + align:start position:0% +uh sorry each of the code bits is +encoded as a linear transformation of + + align:start position:0% +encoded as a linear transformation of + + + align:start position:0% +encoded as a linear transformation of +the message but so i didn't quite say it + + align:start position:0% +the message but so i didn't quite say it + + + align:start position:0% +the message but so i didn't quite say it +that way there let me say it here + + align:start position:0% +that way there let me say it here + + + align:start position:0% +that way there let me say it here +on this slide so + + align:start position:0% +on this slide so + + + align:start position:0% +on this slide so +each code word bit is a specified linear + + align:start position:0% +each code word bit is a specified linear + + + align:start position:0% +each code word bit is a specified linear +combination of the message bits + + align:start position:0% +combination of the message bits + + + align:start position:0% +combination of the message bits +this is what i'm referring to if you + + align:start position:0% +this is what i'm referring to if you + + + align:start position:0% +this is what i'm referring to if you +wanted to find any particular bit + + align:start position:0% +wanted to find any particular bit + + + align:start position:0% +wanted to find any particular bit +you're going to take a linear + + align:start position:0% +you're going to take a linear + + + align:start position:0% +you're going to take a linear +combination of these bits with the + + align:start position:0% +combination of these bits with the + + + align:start position:0% +combination of these bits with the +weights that are here + + align:start position:0% +weights that are here + + + align:start position:0% +weights that are here +okay there's another way to think of + + align:start position:0% +okay there's another way to think of + + + align:start position:0% +okay there's another way to think of +this also which is the other + + align:start position:0% +this also which is the other + + + align:start position:0% +this also which is the other +blue line out there + + align:start position:0% + + + + align:start position:0% + +which is to think of the matrix g as + + align:start position:0% +which is to think of the matrix g as + + + align:start position:0% +which is to think of the matrix g as +being made up of rows + + align:start position:0% + + + + align:start position:0% + +okay so can someone describe to me what + + align:start position:0% +okay so can someone describe to me what + + + align:start position:0% +okay so can someone describe to me what +we're doing with these rows to get this + + align:start position:0% +we're doing with these rows to get this + + + align:start position:0% +we're doing with these rows to get this +entire code + + align:start position:0% +entire code + + + align:start position:0% +entire code +vector yeah + + align:start position:0% + + + + align:start position:0% + +okay so basically the way matrix + + align:start position:0% +okay so basically the way matrix + + + align:start position:0% +okay so basically the way matrix +multiplication works if you + + align:start position:0% +multiplication works if you + + + align:start position:0% +multiplication works if you +think about it is what we're going to be + + align:start position:0% +think about it is what we're going to be + + + align:start position:0% +think about it is what we're going to be +doing is one times the first row + + align:start position:0% +doing is one times the first row + + + align:start position:0% +doing is one times the first row +plus zero times the second row plus one + + align:start position:0% +plus zero times the second row plus one + + + align:start position:0% +plus zero times the second row plus one +times the third row plus one times the + + align:start position:0% +times the third row plus one times the + + + align:start position:0% +times the third row plus one times the +fourth row + + align:start position:0% +fourth row + + + align:start position:0% +fourth row +so what we do another way to think of + + align:start position:0% +so what we do another way to think of + + + align:start position:0% +so what we do another way to think of +matrix multiplication is going to + + align:start position:0% +matrix multiplication is going to + + + align:start position:0% +matrix multiplication is going to +generate this vector as a linear + + align:start position:0% +generate this vector as a linear + + + align:start position:0% +generate this vector as a linear +combination of the rows of this matrix + + align:start position:0% +combination of the rows of this matrix + + + align:start position:0% +combination of the rows of this matrix +okay what linear combination well the + + align:start position:0% +okay what linear combination well the + + + align:start position:0% +okay what linear combination well the +linear combination that's described in + + align:start position:0% +linear combination that's described in + + + align:start position:0% +linear combination that's described in +the + + align:start position:0% +the + + + align:start position:0% +the +message part of this so this is the + + align:start position:0% +message part of this so this is the + + + align:start position:0% +message part of this so this is the +message part + + align:start position:0% + + + + align:start position:0% + +so that's the other statement out here + + align:start position:0% +so that's the other statement out here + + + align:start position:0% +so that's the other statement out here +so each code word is a linear + + align:start position:0% +so each code word is a linear + + + align:start position:0% +so each code word is a linear +combination of the rows of this + + align:start position:0% +combination of the rows of this + + + align:start position:0% +combination of the rows of this +generator matrix + + align:start position:0% +generator matrix + + + align:start position:0% +generator matrix +all right so these are concrete ways to + + align:start position:0% +all right so these are concrete ways to + + + align:start position:0% +all right so these are concrete ways to +think about + + align:start position:0% +think about + + + align:start position:0% +think about +what a linear code is but we also saw + + align:start position:0% +what a linear code is but we also saw + + + align:start position:0% +what a linear code is but we also saw +that there's another way to + + align:start position:0% +that there's another way to + + + align:start position:0% +that there's another way to +think of it which is in terms of this + + align:start position:0% +think of it which is in terms of this + + + align:start position:0% +think of it which is in terms of this +property + + align:start position:0% +property + + + align:start position:0% +property +that the sum of any two code words is + + align:start position:0% +that the sum of any two code words is + + + align:start position:0% +that the sum of any two code words is +also a code word so if you have a + + align:start position:0% +also a code word so if you have a + + + align:start position:0% +also a code word so if you have a +set of code words with the property that + + align:start position:0% +set of code words with the property that + + + align:start position:0% +set of code words with the property that +the sum of any two + + align:start position:0% +the sum of any two + + + align:start position:0% +the sum of any two +is another word in that set another code + + align:start position:0% +is another word in that set another code + + + align:start position:0% +is another word in that set another code +word in that set then what you have is a + + align:start position:0% +word in that set then what you have is a + + + align:start position:0% +word in that set then what you have is a +linear code + + align:start position:0% +linear code + + + align:start position:0% +linear code +and we argue that the all zeros code + + align:start position:0% +and we argue that the all zeros code + + + align:start position:0% +and we argue that the all zeros code +code word must be in there + + align:start position:0% +code word must be in there + + + align:start position:0% +code word must be in there +because when you add a code word to + + align:start position:0% +because when you add a code word to + + + align:start position:0% +because when you add a code word to +itself you get the all zeros + + align:start position:0% +itself you get the all zeros + + + align:start position:0% +itself you get the all zeros +code word right okay + + align:start position:0% +code word right okay + + + align:start position:0% +code word right okay +so that's the class of codes we're going + + align:start position:0% +so that's the class of codes we're going + + + align:start position:0% +so that's the class of codes we're going +to be uh focusing on + + align:start position:0% + + + + align:start position:0% + +but i'm going to make a further + + align:start position:0% +but i'm going to make a further + + + align:start position:0% +but i'm going to make a further +restriction + + align:start position:0% + + + + align:start position:0% + +which is that i'm going to look at + + align:start position:0% + + + + align:start position:0% + +code words that are of a very special + + align:start position:0% +code words that are of a very special + + + align:start position:0% +code words that are of a very special +type so i'm going to + + align:start position:0% +type so i'm going to + + + align:start position:0% +type so i'm going to +limit myself to code words that have + + align:start position:0% +limit myself to code words that have + + + align:start position:0% +limit myself to code words that have +this structure + + align:start position:0% + + + + align:start position:0% + +so here's my data bits d1 up to dk + + align:start position:0% +so here's my data bits d1 up to dk + + + align:start position:0% +so here's my data bits d1 up to dk +i'm going to pick my code word so that + + align:start position:0% +i'm going to pick my code word so that + + + align:start position:0% +i'm going to pick my code word so that +the + + align:start position:0% + + + + align:start position:0% + +let's say the first k bits are precisely + + align:start position:0% +let's say the first k bits are precisely + + + align:start position:0% +let's say the first k bits are precisely +the data bits + + align:start position:0% +the data bits + + + align:start position:0% +the data bits +and then i'll pick the additional ones + + align:start position:0% +and then i'll pick the additional ones + + + align:start position:0% +and then i'll pick the additional ones +to be some set of + + align:start position:0% +to be some set of + + + align:start position:0% +to be some set of +what we'll call parity bits so this is + + align:start position:0% +what we'll call parity bits so this is + + + align:start position:0% +what we'll call parity bits so this is +p1 up to pn minus k all right so i'm not + + align:start position:0% +p1 up to pn minus k all right so i'm not + + + align:start position:0% +p1 up to pn minus k all right so i'm not +going to + + align:start position:0% +going to + + + align:start position:0% +going to +have an arbitrary transformation here + + align:start position:0% +have an arbitrary transformation here + + + align:start position:0% +have an arbitrary transformation here +i'm going to restrict myself to + + align:start position:0% +i'm going to restrict myself to + + + align:start position:0% +i'm going to restrict myself to +transformations + + align:start position:0% +transformations + + + align:start position:0% +transformations +that have the property that when i + + align:start position:0% +that have the property that when i + + + align:start position:0% +that have the property that when i +multiply by the data + + align:start position:0% +multiply by the data + + + align:start position:0% +multiply by the data +vector here what i get is the data + + align:start position:0% +vector here what i get is the data + + + align:start position:0% +vector here what i get is the data +vector reproduced in the initial part + + align:start position:0% +vector reproduced in the initial part + + + align:start position:0% +vector reproduced in the initial part +and then a bunch of new + + align:start position:0% +and then a bunch of new + + + align:start position:0% +and then a bunch of new +bits representing the redundant + + align:start position:0% +bits representing the redundant + + + align:start position:0% +bits representing the redundant +relationships that i'm computing we + + align:start position:0% +relationships that i'm computing we + + + align:start position:0% +relationships that i'm computing we +refer to them as parity bits + + align:start position:0% + + + + align:start position:0% + +it's not so important that the data bits + + align:start position:0% +it's not so important that the data bits + + + align:start position:0% +it's not so important that the data bits +being the first + + align:start position:0% +being the first + + + align:start position:0% +being the first +k positions i'm willing to tolerate + + align:start position:0% +k positions i'm willing to tolerate + + + align:start position:0% +k positions i'm willing to tolerate +variations of this where the data bits + + align:start position:0% +variations of this where the data bits + + + align:start position:0% +variations of this where the data bits +are somewhere in this code vector + + align:start position:0% +are somewhere in this code vector + + + align:start position:0% +are somewhere in this code vector +but the key thing about what's called a + + align:start position:0% +but the key thing about what's called a + + + align:start position:0% +but the key thing about what's called a +systematic code is that when i look at + + align:start position:0% +systematic code is that when i look at + + + align:start position:0% +systematic code is that when i look at +the code word + + align:start position:0% +the code word + + + align:start position:0% +the code word +in designated positions i find the data + + align:start position:0% +in designated positions i find the data + + + align:start position:0% +in designated positions i find the data +bits and the other positions are the + + align:start position:0% +bits and the other positions are the + + + align:start position:0% +bits and the other positions are the +so-called parity bits + + align:start position:0% +so-called parity bits + + + align:start position:0% +so-called parity bits +that are obtained as linear combinations + + align:start position:0% +that are obtained as linear combinations + + + align:start position:0% +that are obtained as linear combinations +of the data bits + + align:start position:0% +of the data bits + + + align:start position:0% +of the data bits +okay so if you are familiar with + + align:start position:0% +okay so if you are familiar with + + + align:start position:0% +okay so if you are familiar with +matrix operations then you know that + + align:start position:0% +matrix operations then you know that + + + align:start position:0% +matrix operations then you know that +what i'll need + + align:start position:0% +what i'll need + + + align:start position:0% +what i'll need +is all the way down the diagonal to have + + align:start position:0% +is all the way down the diagonal to have + + + align:start position:0% +is all the way down the diagonal to have +a matrix that has ones + + align:start position:0% +a matrix that has ones + + + align:start position:0% +a matrix that has ones +along the diagonal zeros everywhere else + + align:start position:0% +along the diagonal zeros everywhere else + + + align:start position:0% +along the diagonal zeros everywhere else +and then something here let me just call + + align:start position:0% +and then something here let me just call + + + align:start position:0% +and then something here let me just call +this + + align:start position:0% +this + + + align:start position:0% +this +matrix of leftover zeros and ones matrix + + align:start position:0% +matrix of leftover zeros and ones matrix + + + align:start position:0% +matrix of leftover zeros and ones matrix +a + + align:start position:0% +a + + + align:start position:0% +a +okay so i've got here a k times k matrix + + align:start position:0% + + + + align:start position:0% + +k times k matrix with ones down the + + align:start position:0% +k times k matrix with ones down the + + + align:start position:0% +k times k matrix with ones down the +diagonal + + align:start position:0% +diagonal + + + align:start position:0% +diagonal +and zero's everywhere else and then i've + + align:start position:0% +and zero's everywhere else and then i've + + + align:start position:0% +and zero's everywhere else and then i've +got a matrix + + align:start position:0% +got a matrix + + + align:start position:0% +got a matrix +which has zeros and ones in it this is + + align:start position:0% +which has zeros and ones in it this is + + + align:start position:0% +which has zeros and ones in it this is +going to be uh + + align:start position:0% +going to be uh + + + align:start position:0% +going to be uh +what is it k times n minus k right + + align:start position:0% +what is it k times n minus k right + + + align:start position:0% +what is it k times n minus k right +so do you buy this so think about how + + align:start position:0% +so do you buy this so think about how + + + align:start position:0% +so do you buy this so think about how +matrix multiplication works if i want + + align:start position:0% +matrix multiplication works if i want + + + align:start position:0% +matrix multiplication works if i want +the first column on the left + + align:start position:0% +the first column on the left + + + align:start position:0% +the first column on the left +i take this row inner product or dot + + align:start position:0% +i take this row inner product or dot + + + align:start position:0% +i take this row inner product or dot +product with the first column here + + align:start position:0% +product with the first column here + + + align:start position:0% +product with the first column here +that just selects out d1 and indeed i + + align:start position:0% +that just selects out d1 and indeed i + + + align:start position:0% +that just selects out d1 and indeed i +got d1 there + + align:start position:0% +got d1 there + + + align:start position:0% +got d1 there +and that happens for the first k + + align:start position:0% +and that happens for the first k + + + align:start position:0% +and that happens for the first k +positions beyond that i'm taking linear + + align:start position:0% +positions beyond that i'm taking linear + + + align:start position:0% +positions beyond that i'm taking linear +combinations with whatever sits here + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +it turns out that this is not really a + + align:start position:0% +it turns out that this is not really a + + + align:start position:0% +it turns out that this is not really a +special case + + align:start position:0% +special case + + + align:start position:0% +special case +it turns out that any + + align:start position:0% + + + + align:start position:0% + +code any linear code can be transformed + + align:start position:0% + + + + align:start position:0% + +to this form by invertible operation so + + align:start position:0% +to this form by invertible operation so + + + align:start position:0% +to this form by invertible operation so +basically if you use + + align:start position:0% +basically if you use + + + align:start position:0% +basically if you use +invertible operations on the rows here + + align:start position:0% +invertible operations on the rows here + + + align:start position:0% +invertible operations on the rows here +and some rearrangement of the columns + + align:start position:0% +and some rearrangement of the columns + + + align:start position:0% +and some rearrangement of the columns +you can bring any code + + align:start position:0% +you can bring any code + + + align:start position:0% +you can bring any code +to this form and then the resulting code + + align:start position:0% +to this form and then the resulting code + + + align:start position:0% +to this form and then the resulting code +will have + + align:start position:0% +will have + + + align:start position:0% +will have +effectively the same error correction + + align:start position:0% +effectively the same error correction + + + align:start position:0% +effectively the same error correction +properties that + + align:start position:0% +properties that + + + align:start position:0% +properties that +the code out here did okay so we're just + + align:start position:0% +the code out here did okay so we're just + + + align:start position:0% +the code out here did okay so we're just +going to limit ourselves to thinking of + + align:start position:0% +going to limit ourselves to thinking of + + + align:start position:0% +going to limit ourselves to thinking of +linear codes which are on the so-called + + align:start position:0% +linear codes which are on the so-called + + + align:start position:0% +linear codes which are on the so-called +systematic form + + align:start position:0% + + + + align:start position:0% + +in other words some part of the code + + align:start position:0% +in other words some part of the code + + + align:start position:0% +in other words some part of the code +word is the message bits and the other + + align:start position:0% +word is the message bits and the other + + + align:start position:0% +word is the message bits and the other +part is + + align:start position:0% +part is + + + align:start position:0% +part is +party bits + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so let's look at a specific code that + + align:start position:0% +so let's look at a specific code that + + + align:start position:0% +so let's look at a specific code that +is of this form very simple code + + align:start position:0% + + + + align:start position:0% + +referred to as a rectangular code you + + align:start position:0% +referred to as a rectangular code you + + + align:start position:0% +referred to as a rectangular code you +see a particular example on this slide + + align:start position:0% +see a particular example on this slide + + + align:start position:0% +see a particular example on this slide +here + + align:start position:0% + + + + align:start position:0% + +so what do we do um we arrange our + + align:start position:0% +so what do we do um we arrange our + + + align:start position:0% +so what do we do um we arrange our +data bits into a matrix which could be + + align:start position:0% +data bits into a matrix which could be + + + align:start position:0% +data bits into a matrix which could be +rectangular or square depending on + + align:start position:0% +rectangular or square depending on + + + align:start position:0% +rectangular or square depending on +what you have so we're going to have + + align:start position:0% + + + + align:start position:0% + +r rows + + align:start position:0% + + + + align:start position:0% + +and c columns + + align:start position:0% +and c columns + + + align:start position:0% +and c columns +okay uh with the data bits in here so d1 + + align:start position:0% +okay uh with the data bits in here so d1 + + + align:start position:0% +okay uh with the data bits in here so d1 +d2 + + align:start position:0% +d2 + + + align:start position:0% +d2 +all the way up to d sub let's say r + + align:start position:0% +all the way up to d sub let's say r + + + align:start position:0% +all the way up to d sub let's say r +times c + + align:start position:0% +times c + + + align:start position:0% +times c +right + + align:start position:0% + + + + align:start position:0% + +in this particular case r and c are both + + align:start position:0% +in this particular case r and c are both + + + align:start position:0% +in this particular case r and c are both +too + + align:start position:0% + + + + align:start position:0% + +uh and then you're going to generate the + + align:start position:0% +uh and then you're going to generate the + + + align:start position:0% +uh and then you're going to generate the +parity bits in this simple fashion what + + align:start position:0% +parity bits in this simple fashion what + + + align:start position:0% +parity bits in this simple fashion what +you're going to do is choose + + align:start position:0% +you're going to do is choose + + + align:start position:0% +you're going to do is choose +a parity bit associated with the first + + align:start position:0% +a parity bit associated with the first + + + align:start position:0% +a parity bit associated with the first +row uh that basically + + align:start position:0% +row uh that basically + + + align:start position:0% +row uh that basically +make sure that in the first row + + align:start position:0% +make sure that in the first row + + + align:start position:0% +make sure that in the first row +including the parity bit you've got an + + align:start position:0% +including the parity bit you've got an + + + align:start position:0% +including the parity bit you've got an +even number of ones + + align:start position:0% +even number of ones + + + align:start position:0% +even number of ones +okay so this is a choice for of even + + align:start position:0% +okay so this is a choice for of even + + + align:start position:0% +okay so this is a choice for of even +parity here + + align:start position:0% +parity here + + + align:start position:0% +parity here +similarly in the p2 will be chosen such + + align:start position:0% +similarly in the p2 will be chosen such + + + align:start position:0% +similarly in the p2 will be chosen such +that the second row + + align:start position:0% +that the second row + + + align:start position:0% +that the second row +has even parity in other words you've + + align:start position:0% +has even parity in other words you've + + + align:start position:0% +has even parity in other words you've +got an even number of ones there + + align:start position:0% +got an even number of ones there + + + align:start position:0% +got an even number of ones there +um and for the columns similarly uh p3 + + align:start position:0% +um and for the columns similarly uh p3 + + + align:start position:0% +um and for the columns similarly uh p3 +will be chosen such that + + align:start position:0% +will be chosen such that + + + align:start position:0% +will be chosen such that +uh d1 and d3 and p3 together + + align:start position:0% +uh d1 and d3 and p3 together + + + align:start position:0% +uh d1 and d3 and p3 together +have even parity in other words the the + + align:start position:0% +have even parity in other words the the + + + align:start position:0% +have even parity in other words the the +number of ones + + align:start position:0% +number of ones + + + align:start position:0% +number of ones +uh in that column is even again the same + + align:start position:0% +uh in that column is even again the same + + + align:start position:0% +uh in that column is even again the same +thing for + + align:start position:0% +thing for + + + align:start position:0% +thing for +this column so what you're trying to do + + align:start position:0% +this column so what you're trying to do + + + align:start position:0% +this column so what you're trying to do +is sort of have sentries on the rows and + + align:start position:0% +is sort of have sentries on the rows and + + + align:start position:0% +is sort of have sentries on the rows and +columns + + align:start position:0% +columns + + + align:start position:0% +columns +that will signal when something has + + align:start position:0% +that will signal when something has + + + align:start position:0% +that will signal when something has +happened to um + + align:start position:0% +happened to um + + + align:start position:0% +happened to um +a bit of the intersection that's the + + align:start position:0% +a bit of the intersection that's the + + + align:start position:0% +a bit of the intersection that's the +general idea here + + align:start position:0% +general idea here + + + align:start position:0% +general idea here +all right so you'll take this out and + + align:start position:0% +all right so you'll take this out and + + + align:start position:0% +all right so you'll take this out and +arrange it then so you've got your + + align:start position:0% +arrange it then so you've got your + + + align:start position:0% +arrange it then so you've got your +parity bits um what's the sequence i + + align:start position:0% +parity bits um what's the sequence i + + + align:start position:0% +parity bits um what's the sequence i +used p1 p2 + + align:start position:0% +used p1 p2 + + + align:start position:0% +used p1 p2 +and then more parity bits here + + align:start position:0% + + + + align:start position:0% + +okay so row on column parity bits + + align:start position:0% + + + + align:start position:0% + +so here's a way to think about what + + align:start position:0% +so here's a way to think about what + + + align:start position:0% +so here's a way to think about what +these are explicitly + + align:start position:0% +these are explicitly + + + align:start position:0% +these are explicitly +so what you'll do is p1 is d1 plus d2 + + align:start position:0% +so what you'll do is p1 is d1 plus d2 + + + align:start position:0% +so what you'll do is p1 is d1 plus d2 +when i say plus of course i mean ngf2 so + + align:start position:0% +when i say plus of course i mean ngf2 so + + + align:start position:0% +when i say plus of course i mean ngf2 so +that's modulo 2 + + align:start position:0% +that's modulo 2 + + + align:start position:0% +that's modulo 2 +edition right + + align:start position:0% +edition right + + + align:start position:0% +edition right +does that simple formula ensure that + + align:start position:0% + + + + align:start position:0% + +i've got an even number of ones in + + align:start position:0% +i've got an even number of ones in + + + align:start position:0% +i've got an even number of ones in +that first row right if uh + + align:start position:0% +that first row right if uh + + + align:start position:0% +that first row right if uh +d1 is zero and d2 is one then i'll i'll + + align:start position:0% +d1 is zero and d2 is one then i'll i'll + + + align:start position:0% +d1 is zero and d2 is one then i'll i'll +make this equal to one which is what i + + align:start position:0% +make this equal to one which is what i + + + align:start position:0% +make this equal to one which is what i +need + + align:start position:0% +need + + + align:start position:0% +need +uh if d1 and d2 are both one i'll make + + align:start position:0% +uh if d1 and d2 are both one i'll make + + + align:start position:0% +uh if d1 and d2 are both one i'll make +this zero which is what i need + + align:start position:0% +this zero which is what i need + + + align:start position:0% +this zero which is what i need +and so on so this simple expression + + align:start position:0% +and so on so this simple expression + + + align:start position:0% +and so on so this simple expression +captures it + + align:start position:0% +captures it + + + align:start position:0% +captures it +and similarly for the arts row so for + + align:start position:0% +and similarly for the arts row so for + + + align:start position:0% +and similarly for the arts row so for +each row you make + + align:start position:0% +each row you make + + + align:start position:0% +each row you make +uh the parity bit equal to the sum of + + align:start position:0% +uh the parity bit equal to the sum of + + + align:start position:0% +uh the parity bit equal to the sum of +the uh + + align:start position:0% +the uh + + + align:start position:0% +the uh +data bits in that row similarly for the + + align:start position:0% +data bits in that row similarly for the + + + align:start position:0% +data bits in that row similarly for the +columns okay um + + align:start position:0% +columns okay um + + + align:start position:0% +columns okay um +another thing by the way can you tell me + + align:start position:0% +another thing by the way can you tell me + + + align:start position:0% +another thing by the way can you tell me +what + + align:start position:0% +what + + + align:start position:0% +what +p1 plus d1 plus d2 is going to be in + + align:start position:0% +p1 plus d1 plus d2 is going to be in + + + align:start position:0% +p1 plus d1 plus d2 is going to be in +this case + + align:start position:0% +this case + + + align:start position:0% +this case +if i pick p1 in this fashion + + align:start position:0% +if i pick p1 in this fashion + + + align:start position:0% +if i pick p1 in this fashion +what does it guarantee for p1 plus p2 + + align:start position:0% +what does it guarantee for p1 plus p2 + + + align:start position:0% +what does it guarantee for p1 plus p2 +plus d2 + + align:start position:0% +plus d2 + + + align:start position:0% +plus d2 +sorry zero right + + align:start position:0% +sorry zero right + + + align:start position:0% +sorry zero right +because really i'm taking p1 and adding + + align:start position:0% +because really i'm taking p1 and adding + + + align:start position:0% +because really i'm taking p1 and adding +p1 + + align:start position:0% +p1 + + + align:start position:0% +p1 +again and when i take something and add + + align:start position:0% +again and when i take something and add + + + align:start position:0% +again and when i take something and add +add it to itself in gf2 i get zero + + align:start position:0% +add it to itself in gf2 i get zero + + + align:start position:0% +add it to itself in gf2 i get zero +so this is equal to zero + + align:start position:0% + + + + align:start position:0% + +so these are just two different ways of + + align:start position:0% +so these are just two different ways of + + + align:start position:0% +so these are just two different ways of +thinking about the parity + + align:start position:0% +thinking about the parity + + + align:start position:0% +thinking about the parity +bit here so this is how you compute the + + align:start position:0% +bit here so this is how you compute the + + + align:start position:0% +bit here so this is how you compute the +parity bit + + align:start position:0% +parity bit + + + align:start position:0% +parity bit +whereas this might be referred to as a + + align:start position:0% +whereas this might be referred to as a + + + align:start position:0% +whereas this might be referred to as a +parity relation + + align:start position:0% + + + + align:start position:0% + +it's a linear constraint relating the + + align:start position:0% +it's a linear constraint relating the + + + align:start position:0% +it's a linear constraint relating the +parity bit + + align:start position:0% +parity bit + + + align:start position:0% +parity bit +and the data bits + + align:start position:0% + + + + align:start position:0% + +in fact we might try constructing this + + align:start position:0% +in fact we might try constructing this + + + align:start position:0% +in fact we might try constructing this +matrix as we go right + + align:start position:0% +matrix as we go right + + + align:start position:0% +matrix as we go right +so we've got + + align:start position:0% + + + + align:start position:0% + +d1 d2 d3 b4 + + align:start position:0% +d1 d2 d3 b4 + + + align:start position:0% +d1 d2 d3 b4 +v1 p2 p3 p4 + + align:start position:0% + + + + align:start position:0% + +oops + + align:start position:0% + + + + align:start position:0% + +and here is d1 d2 + + align:start position:0% +and here is d1 d2 + + + align:start position:0% +and here is d1 d2 +d3 d4 i'm going to have my generator + + align:start position:0% +d3 d4 i'm going to have my generator + + + align:start position:0% +d3 d4 i'm going to have my generator +matrix here + + align:start position:0% +matrix here + + + align:start position:0% +matrix here +it's got the identity matrix in this + + align:start position:0% +it's got the identity matrix in this + + + align:start position:0% +it's got the identity matrix in this +first part we use the symbol capital i + + align:start position:0% +first part we use the symbol capital i + + + align:start position:0% +first part we use the symbol capital i +for identity matrix + + align:start position:0% + + + + align:start position:0% + +so when you see identity matrix you know + + align:start position:0% +so when you see identity matrix you know + + + align:start position:0% +so when you see identity matrix you know +it's a matrix with it's a square matrix + + align:start position:0% +it's a matrix with it's a square matrix + + + align:start position:0% +it's a matrix with it's a square matrix +with ones down the diagonals + + align:start position:0% +with ones down the diagonals + + + align:start position:0% +with ones down the diagonals +okay so what goes in the next column + + align:start position:0% +okay so what goes in the next column + + + align:start position:0% +okay so what goes in the next column +over here + + align:start position:0% +over here + + + align:start position:0% +over here +for this particular example the next + + align:start position:0% +for this particular example the next + + + align:start position:0% +for this particular example the next +column over + + align:start position:0% +column over + + + align:start position:0% +column over +is going to be p1 + + align:start position:0% + + + + align:start position:0% + +p1 is d1 plus d2 + + align:start position:0% +p1 is d1 plus d2 + + + align:start position:0% +p1 is d1 plus d2 +so what i need is 1 1 + + align:start position:0% +so what i need is 1 1 + + + align:start position:0% +so what i need is 1 1 +0 0 right + + align:start position:0% + + + + align:start position:0% + +and similarly for the other parity bit + + align:start position:0% +and similarly for the other parity bit + + + align:start position:0% +and similarly for the other parity bit +so you can once you're told the rule + + align:start position:0% +so you can once you're told the rule + + + align:start position:0% +so you can once you're told the rule +here + + align:start position:0% +here + + + align:start position:0% +here +it's easy to generate the the matrix + + align:start position:0% +it's easy to generate the the matrix + + + align:start position:0% +it's easy to generate the the matrix +that goes with it + + align:start position:0% + + + + align:start position:0% + +okay so let's get some practice figuring + + align:start position:0% +okay so let's get some practice figuring + + + align:start position:0% +okay so let's get some practice figuring +out + + align:start position:0% +out + + + align:start position:0% +out +what's what here um let's assume now + + align:start position:0% +what's what here um let's assume now + + + align:start position:0% +what's what here um let's assume now +this is all we're going to be + + align:start position:0% +this is all we're going to be + + + align:start position:0% +this is all we're going to be +aiming to do in this lecture is + + align:start position:0% +aiming to do in this lecture is + + + align:start position:0% +aiming to do in this lecture is +construct codes that correct up to a + + align:start position:0% +construct codes that correct up to a + + + align:start position:0% +construct codes that correct up to a +single error + + align:start position:0% +single error + + + align:start position:0% +single error +so we're focusing on uh singular + + align:start position:0% +so we're focusing on uh singular + + + align:start position:0% +so we're focusing on uh singular +correction codes or what are referred to + + align:start position:0% +correction codes or what are referred to + + + align:start position:0% +correction codes or what are referred to +as sec codes + + align:start position:0% +as sec codes + + + align:start position:0% +as sec codes +okay single error correction so assume + + align:start position:0% +okay single error correction so assume + + + align:start position:0% +okay single error correction so assume +that only one error has happened + + align:start position:0% +that only one error has happened + + + align:start position:0% +that only one error has happened +or zero errors you don't get more than + + align:start position:0% +or zero errors you don't get more than + + + align:start position:0% +or zero errors you don't get more than +one let's say + + align:start position:0% +one let's say + + + align:start position:0% +one let's say +uh if you received this + + align:start position:0% +uh if you received this + + + align:start position:0% +uh if you received this +i've just rearranged the code word into + + align:start position:0% +i've just rearranged the code word into + + + align:start position:0% +i've just rearranged the code word into +the pattern that allows you to look at + + align:start position:0% +the pattern that allows you to look at + + + align:start position:0% +the pattern that allows you to look at +this very easily + + align:start position:0% +this very easily + + + align:start position:0% +this very easily +so here's d1 d2 d3 d4 and so on + + align:start position:0% +so here's d1 d2 d3 d4 and so on + + + align:start position:0% +so here's d1 d2 d3 d4 and so on +um any errors here and this + + align:start position:0% + + + + align:start position:0% + +you can see that if i look along the + + align:start position:0% +you can see that if i look along the + + + align:start position:0% +you can see that if i look along the +first row i've got even parity + + align:start position:0% +first row i've got even parity + + + align:start position:0% +first row i've got even parity +even parity even parity even parity so + + align:start position:0% +even parity even parity even parity so + + + align:start position:0% +even parity even parity even parity so +everything looks fine and i'll declare + + align:start position:0% +everything looks fine and i'll declare + + + align:start position:0% +everything looks fine and i'll declare +that the no errors + + align:start position:0% +that the no errors + + + align:start position:0% +that the no errors +on the other hand if i receive that + + align:start position:0% + + + + align:start position:0% + +okay so here i have a parity check + + align:start position:0% +okay so here i have a parity check + + + align:start position:0% +okay so here i have a parity check +failure + + align:start position:0% +failure + + + align:start position:0% +failure +right um and so i know that something is + + align:start position:0% +right um and so i know that something is + + + align:start position:0% +right um and so i know that something is +wrong in + + align:start position:0% +wrong in + + + align:start position:0% +wrong in +this column i look along the rows i see + + align:start position:0% +this column i look along the rows i see + + + align:start position:0% +this column i look along the rows i see +a parity check failure in that row so i + + align:start position:0% +a parity check failure in that row so i + + + align:start position:0% +a parity check failure in that row so i +pinpoint the error as being at the + + align:start position:0% +pinpoint the error as being at the + + + align:start position:0% +pinpoint the error as being at the +intersection of those two + + align:start position:0% +intersection of those two + + + align:start position:0% +intersection of those two +and i know that's the bit that i have to + + align:start position:0% +and i know that's the bit that i have to + + + align:start position:0% +and i know that's the bit that i have to +flip + + align:start position:0% +flip + + + align:start position:0% +flip +okay + + align:start position:0% + + + + align:start position:0% + +and another case + + align:start position:0% + + + + align:start position:0% + +uh here there is a failure um + + align:start position:0% +uh here there is a failure um + + + align:start position:0% +uh here there is a failure um +on a row but nothing on the + + align:start position:0% +on a row but nothing on the + + + align:start position:0% +on a row but nothing on the +corresponding columns + + align:start position:0% +corresponding columns + + + align:start position:0% +corresponding columns +so what that tells us it's actually the + + align:start position:0% +so what that tells us it's actually the + + + align:start position:0% +so what that tells us it's actually the +parity bit that's failed + + align:start position:0% +parity bit that's failed + + + align:start position:0% +parity bit that's failed +right everything else looks fine but the + + align:start position:0% +right everything else looks fine but the + + + align:start position:0% +right everything else looks fine but the +parity bit has failed if there's a + + align:start position:0% +parity bit has failed if there's a + + + align:start position:0% +parity bit has failed if there's a +single error to correct it would be to + + align:start position:0% +single error to correct it would be to + + + align:start position:0% +single error to correct it would be to +make + + align:start position:0% +make + + + align:start position:0% +make +convert this one to a zero and then all + + align:start position:0% +convert this one to a zero and then all + + + align:start position:0% +convert this one to a zero and then all +parity relations are satisfied + + align:start position:0% +parity relations are satisfied + + + align:start position:0% +parity relations are satisfied +okay so you can get errors on the parity + + align:start position:0% +okay so you can get errors on the parity + + + align:start position:0% +okay so you can get errors on the parity +bits as easily as you get them in the + + align:start position:0% +bits as easily as you get them in the + + + align:start position:0% +bits as easily as you get them in the +data bits because the channel doesn't + + align:start position:0% +data bits because the channel doesn't + + + align:start position:0% +data bits because the channel doesn't +know the difference + + align:start position:0% +know the difference + + + align:start position:0% +know the difference +the channel is just seen seeing a + + align:start position:0% +the channel is just seen seeing a + + + align:start position:0% +the channel is just seen seeing a +sequence of bits + + align:start position:0% +sequence of bits + + + align:start position:0% +sequence of bits +all right so this is how you work + + align:start position:0% +all right so this is how you work + + + align:start position:0% +all right so this is how you work +backwards + + align:start position:0% +backwards + + + align:start position:0% +backwards +to figure out what's going on + + align:start position:0% + + + + align:start position:0% + +another way to say it and we'll see this + + align:start position:0% +another way to say it and we'll see this + + + align:start position:0% +another way to say it and we'll see this +later is + + align:start position:0% +later is + + + align:start position:0% +later is +um you get what should be d1 and d2 but + + align:start position:0% +um you get what should be d1 and d2 but + + + align:start position:0% +um you get what should be d1 and d2 but +you're not sure yet whether they're an + + align:start position:0% +you're not sure yet whether they're an + + + align:start position:0% +you're not sure yet whether they're an +error or not so let me call them d1 + + align:start position:0% +error or not so let me call them d1 + + + align:start position:0% +error or not so let me call them d1 +prime and d2 prime for now + + align:start position:0% +prime and d2 prime for now + + + align:start position:0% +prime and d2 prime for now +so you compute your estimate of + + align:start position:0% +so you compute your estimate of + + + align:start position:0% +so you compute your estimate of +the first parity relationship and + + align:start position:0% +the first parity relationship and + + + align:start position:0% +the first parity relationship and +compare it with what's sitting in + + align:start position:0% +compare it with what's sitting in + + + align:start position:0% +compare it with what's sitting in +uh well let me say is are these equal so + + align:start position:0% +uh well let me say is are these equal so + + + align:start position:0% +uh well let me say is are these equal so +what you're doing is you're computing um + + align:start position:0% +what you're doing is you're computing um + + + align:start position:0% +what you're doing is you're computing um +your estimate of the parity relationship + + align:start position:0% +your estimate of the parity relationship + + + align:start position:0% +your estimate of the parity relationship +based on what's sitting in the code word + + align:start position:0% +based on what's sitting in the code word + + + align:start position:0% +based on what's sitting in the code word +in these positions + + align:start position:0% +in these positions + + + align:start position:0% +in these positions +and seeing whether it's equal to what + + align:start position:0% +and seeing whether it's equal to what + + + align:start position:0% +and seeing whether it's equal to what +you think it should equal + + align:start position:0% +you think it should equal + + + align:start position:0% +you think it should equal +okay and if it's equal then you say that + + align:start position:0% +okay and if it's equal then you say that + + + align:start position:0% +okay and if it's equal then you say that +parity relation is satisfied + + align:start position:0% +parity relation is satisfied + + + align:start position:0% +parity relation is satisfied +and otherwise you try and make a change + + align:start position:0% +and otherwise you try and make a change + + + align:start position:0% +and otherwise you try and make a change +now we'll see how to do this more + + align:start position:0% +now we'll see how to do this more + + + align:start position:0% +now we'll see how to do this more +systematically next lecture actually + + align:start position:0% +systematically next lecture actually + + + align:start position:0% +systematically next lecture actually +when we'll + + align:start position:0% +when we'll + + + align:start position:0% +when we'll +go further with the matrix story but i'm + + align:start position:0% +go further with the matrix story but i'm + + + align:start position:0% +go further with the matrix story but i'm +just trying to get you + + align:start position:0% +just trying to get you + + + align:start position:0% +just trying to get you +a little oriented here okay + + align:start position:0% + + + + align:start position:0% + +so you probably believe by now that + + align:start position:0% +so you probably believe by now that + + + align:start position:0% +so you probably believe by now that +this code can correct single errors + + align:start position:0% +this code can correct single errors + + + align:start position:0% +this code can correct single errors +right the rectangular code can correct + + align:start position:0% +right the rectangular code can correct + + + align:start position:0% +right the rectangular code can correct +single errors basically + + align:start position:0% +single errors basically + + + align:start position:0% +single errors basically +um an error in a message bit is + + align:start position:0% +um an error in a message bit is + + + align:start position:0% +um an error in a message bit is +pinpointed by + + align:start position:0% +pinpointed by + + + align:start position:0% +pinpointed by +parity errors on the rowan column a + + align:start position:0% +parity errors on the rowan column a + + + align:start position:0% +parity errors on the rowan column a +message in + + align:start position:0% +message in + + + align:start position:0% +message in +a parity bit has been pointed by just an + + align:start position:0% +a parity bit has been pointed by just an + + + align:start position:0% +a parity bit has been pointed by just an +error in the parity + + align:start position:0% +error in the parity + + + align:start position:0% +error in the parity +row or column and if you get something + + align:start position:0% +row or column and if you get something + + + align:start position:0% +row or column and if you get something +other than that then you say you have an + + align:start position:0% +other than that then you say you have an + + + align:start position:0% +other than that then you say you have an +uncorrectable error + + align:start position:0% +uncorrectable error + + + align:start position:0% +uncorrectable error +right you're not set up to do things + + align:start position:0% +right you're not set up to do things + + + align:start position:0% +right you're not set up to do things +with other + + align:start position:0% +with other + + + align:start position:0% +with other +errors there but now how do we know the + + align:start position:0% +errors there but now how do we know the + + + align:start position:0% +errors there but now how do we know the +hamming + + align:start position:0% +hamming + + + align:start position:0% +hamming +distance is three the minimum hamming + + align:start position:0% +distance is three the minimum hamming + + + align:start position:0% +distance is three the minimum hamming +distance is three + + align:start position:0% +distance is three + + + align:start position:0% +distance is three +we know that if the minimum having + + align:start position:0% +we know that if the minimum having + + + align:start position:0% +we know that if the minimum having +distance is three we can collect correct + + align:start position:0% +distance is three we can collect correct + + + align:start position:0% +distance is three we can collect correct +a single error + + align:start position:0% +a single error + + + align:start position:0% +a single error +but it's possible that the minimum + + align:start position:0% +but it's possible that the minimum + + + align:start position:0% +but it's possible that the minimum +having distance is greater than three + + align:start position:0% +having distance is greater than three + + + align:start position:0% +having distance is greater than three +for this case + + align:start position:0% +for this case + + + align:start position:0% +for this case +which might mean we have more + + align:start position:0% +which might mean we have more + + + align:start position:0% +which might mean we have more +possibilities so + + align:start position:0% +possibilities so + + + align:start position:0% +possibilities so +how can we establish what the minimum + + align:start position:0% +how can we establish what the minimum + + + align:start position:0% +how can we establish what the minimum +hamming distance is + + align:start position:0% + + + + align:start position:0% + +any ideas yeah + + align:start position:0% + + + + align:start position:0% + +okay so um am i going to search all + + align:start position:0% +okay so um am i going to search all + + + align:start position:0% +okay so um am i going to search all +pairs so the suggestion was change + + align:start position:0% +pairs so the suggestion was change + + + align:start position:0% +pairs so the suggestion was change +something till you + + align:start position:0% +something till you + + + align:start position:0% +something till you +until you find a hamming distance of + + align:start position:0% +until you find a hamming distance of + + + align:start position:0% +until you find a hamming distance of +three um and presumably you won't find + + align:start position:0% +three um and presumably you won't find + + + align:start position:0% +three um and presumably you won't find +anything smaller + + align:start position:0% +anything smaller + + + align:start position:0% +anything smaller +right okay because we know we can + + align:start position:0% +right okay because we know we can + + + align:start position:0% +right okay because we know we can +correct single errors + + align:start position:0% +correct single errors + + + align:start position:0% +correct single errors +but am i going to search through all + + align:start position:0% +but am i going to search through all + + + align:start position:0% +but am i going to search through all +pairs of code words + + align:start position:0% +pairs of code words + + + align:start position:0% +pairs of code words +um to do this or can i do something + + align:start position:0% +um to do this or can i do something + + + align:start position:0% +um to do this or can i do something +better + + align:start position:0% + + + + align:start position:0% + +so you're giving me a particular + + align:start position:0% +so you're giving me a particular + + + align:start position:0% +so you're giving me a particular +computation here but i don't know that + + align:start position:0% +computation here but i don't know that + + + align:start position:0% +computation here but i don't know that +you've answered my question which was + + align:start position:0% +you've answered my question which was + + + align:start position:0% +you've answered my question which was +am i going to have to search through all + + align:start position:0% +am i going to have to search through all + + + align:start position:0% +am i going to have to search through all +pairs of + + align:start position:0% +pairs of + + + align:start position:0% +pairs of +code words to see that i can establish a + + align:start position:0% +code words to see that i can establish a + + + align:start position:0% +code words to see that i can establish a +minimum distance of three or is there + + align:start position:0% +minimum distance of three or is there + + + align:start position:0% +minimum distance of three or is there +something simpler than that that i can + + align:start position:0% +something simpler than that that i can + + + align:start position:0% +something simpler than that that i can +do + + align:start position:0% + + + + align:start position:0% + +can you speak up my hearing is not great + + align:start position:0% +can you speak up my hearing is not great + + + align:start position:0% +can you speak up my hearing is not great +sorry + + align:start position:0% + + + + align:start position:0% + +oh so you've got a general formula okay + + align:start position:0% +oh so you've got a general formula okay + + + align:start position:0% +oh so you've got a general formula okay +um + + align:start position:0% +um + + + align:start position:0% +um +can you invoke linearity in some way + + align:start position:0% +can you invoke linearity in some way + + + align:start position:0% +can you invoke linearity in some way +because i haven't heard you + + align:start position:0% +because i haven't heard you + + + align:start position:0% +because i haven't heard you +use the linearity of the code in + + align:start position:0% +use the linearity of the code in + + + align:start position:0% +use the linearity of the code in +anything you've said + + align:start position:0% + + + + align:start position:0% + +were you going to offer a suggestion + + align:start position:0% +were you going to offer a suggestion + + + align:start position:0% +were you going to offer a suggestion +yeah + + align:start position:0% + + + + align:start position:0% + +okay okay so i think i get what your + + align:start position:0% +okay okay so i think i get what your + + + align:start position:0% +okay okay so i think i get what your +argument is you're saying start from an + + align:start position:0% +argument is you're saying start from an + + + align:start position:0% +argument is you're saying start from an +arbitrary message bit + + align:start position:0% +arbitrary message bit + + + align:start position:0% +arbitrary message bit +and then if you make any flip you'll get + + align:start position:0% +and then if you make any flip you'll get + + + align:start position:0% +and then if you make any flip you'll get +at least three that may have been the + + align:start position:0% +at least three that may have been the + + + align:start position:0% +at least three that may have been the +earlier argument which i missed + + align:start position:0% +earlier argument which i missed + + + align:start position:0% +earlier argument which i missed +right is there a is there a way to + + align:start position:0% +right is there a is there a way to + + + align:start position:0% +right is there a is there a way to +invoke uh the linearity of the code in + + align:start position:0% +invoke uh the linearity of the code in + + + align:start position:0% +invoke uh the linearity of the code in +making these arguments + + align:start position:0% +making these arguments + + + align:start position:0% +making these arguments +you're on the right track but i just + + align:start position:0% +you're on the right track but i just + + + align:start position:0% +you're on the right track but i just +want to see if linearity can be invoked + + align:start position:0% +want to see if linearity can be invoked + + + align:start position:0% +want to see if linearity can be invoked +yeah + + align:start position:0% + + + + align:start position:0% + +right so what we've established is that + + align:start position:0% +right so what we've established is that + + + align:start position:0% +right so what we've established is that +for a linear code + + align:start position:0% +for a linear code + + + align:start position:0% +for a linear code +the minimum hamming distance is the + + align:start position:0% +the minimum hamming distance is the + + + align:start position:0% +the minimum hamming distance is the +minimum weight among all non-zero + + align:start position:0% +minimum weight among all non-zero + + + align:start position:0% +minimum weight among all non-zero +vectors + + align:start position:0% +vectors + + + align:start position:0% +vectors +right so all you have to do is start + + align:start position:0% +right so all you have to do is start + + + align:start position:0% +right so all you have to do is start +with the zero + + align:start position:0% +with the zero + + + align:start position:0% +with the zero +code word everything's zero and then + + align:start position:0% +code word everything's zero and then + + + align:start position:0% +code word everything's zero and then +flip a bit and see + + align:start position:0% +flip a bit and see + + + align:start position:0% +flip a bit and see +um flip a bit and see + + align:start position:0% +um flip a bit and see + + + align:start position:0% +um flip a bit and see +uh flip a bit in the message + + align:start position:0% +uh flip a bit in the message + + + align:start position:0% +uh flip a bit in the message +okay and then see if you get uh hamming + + align:start position:0% +okay and then see if you get uh hamming + + + align:start position:0% +okay and then see if you get uh hamming +distance + + align:start position:0% +distance + + + align:start position:0% +distance +three or greater okay so we can start + + align:start position:0% +three or greater okay so we can start + + + align:start position:0% +three or greater okay so we can start +with the zero code word i guess that's + + align:start position:0% +with the zero code word i guess that's + + + align:start position:0% +with the zero code word i guess that's +the point i was going to make here + + align:start position:0% +the point i was going to make here + + + align:start position:0% +the point i was going to make here +okay + + align:start position:0% + + + + align:start position:0% + +there is another expression that popped + + align:start position:0% +there is another expression that popped + + + align:start position:0% +there is another expression that popped +up there before completing that argument + + align:start position:0% +up there before completing that argument + + + align:start position:0% +up there before completing that argument +do you agree with what it said about the + + align:start position:0% +do you agree with what it said about the + + + align:start position:0% +do you agree with what it said about the +code rate + + align:start position:0% +code rate + + + align:start position:0% +code rate +it says the code rate is rc over + + align:start position:0% + + + + align:start position:0% + +rc plus r plus c + + align:start position:0% +rc plus r plus c + + + align:start position:0% +rc plus r plus c +is that do you agree with that yeah + + align:start position:0% +is that do you agree with that yeah + + + align:start position:0% +is that do you agree with that yeah +because we have + + align:start position:0% +because we have + + + align:start position:0% +because we have +um the number of message bits being + + align:start position:0% +um the number of message bits being + + + align:start position:0% +um the number of message bits being +rc and then the total number of bits is + + align:start position:0% +rc and then the total number of bits is + + + align:start position:0% +rc and then the total number of bits is +rc + + align:start position:0% +rc + + + align:start position:0% +rc +plus r plus c so the rate is indeed + + align:start position:0% +plus r plus c so the rate is indeed + + + align:start position:0% +plus r plus c so the rate is indeed +what's given by that expression + + align:start position:0% +what's given by that expression + + + align:start position:0% +what's given by that expression +okay and then we'll go on to make this + + align:start position:0% +okay and then we'll go on to make this + + + align:start position:0% +okay and then we'll go on to make this +argument about um + + align:start position:0% +argument about um + + + align:start position:0% +argument about um +the three cases here so you can actually + + align:start position:0% +the three cases here so you can actually + + + align:start position:0% +the three cases here so you can actually +go case by case + + align:start position:0% +go case by case + + + align:start position:0% +go case by case +and the argument here is actually closer + + align:start position:0% +and the argument here is actually closer + + + align:start position:0% +and the argument here is actually closer +to what was being described out there it + + align:start position:0% +to what was being described out there it + + + align:start position:0% +to what was being described out there it +doesn't start with the + + align:start position:0% +doesn't start with the + + + align:start position:0% +doesn't start with the +zero message but it says if you've got + + align:start position:0% +zero message but it says if you've got + + + align:start position:0% +zero message but it says if you've got +two messages that differ + + align:start position:0% +two messages that differ + + + align:start position:0% +two messages that differ +in one bit in the message area then + + align:start position:0% +in one bit in the message area then + + + align:start position:0% +in one bit in the message area then +they're going to defer + + align:start position:0% +they're going to defer + + + align:start position:0% +they're going to defer +by one bit in the associated parity + + align:start position:0% +by one bit in the associated parity + + + align:start position:0% +by one bit in the associated parity +areas and therefore the overall code + + align:start position:0% +areas and therefore the overall code + + + align:start position:0% +areas and therefore the overall code +word has moved by three + + align:start position:0% +word has moved by three + + + align:start position:0% +word has moved by three +and then you go through each of the + + align:start position:0% +and then you go through each of the + + + align:start position:0% +and then you go through each of the +cases and you argue that you've + + align:start position:0% +cases and you argue that you've + + + align:start position:0% +cases and you argue that you've +moved by at least three so this argument + + align:start position:0% +moved by at least three so this argument + + + align:start position:0% +moved by at least three so this argument +is actually closer to what + + align:start position:0% +is actually closer to what + + + align:start position:0% +is actually closer to what +was being suggested earlier okay so you + + align:start position:0% +was being suggested earlier okay so you + + + align:start position:0% +was being suggested earlier okay so you +can go through each of the cases and + + align:start position:0% +can go through each of the cases and + + + align:start position:0% +can go through each of the cases and +discover that + + align:start position:0% +discover that + + + align:start position:0% +discover that +um the nearest code word you can get to + + align:start position:0% +um the nearest code word you can get to + + + align:start position:0% +um the nearest code word you can get to +is + + align:start position:0% +is + + + align:start position:0% +is +hamming distance three away all right + + align:start position:0% + + + + align:start position:0% + +why is it that we're flipping a bit in + + align:start position:0% +why is it that we're flipping a bit in + + + align:start position:0% +why is it that we're flipping a bit in +the + + align:start position:0% +the + + + align:start position:0% +the +message section to decide what's a new + + align:start position:0% +message section to decide what's a new + + + align:start position:0% +message section to decide what's a new +case + + align:start position:0% + + + + align:start position:0% + +the way we count our code words is by + + align:start position:0% +the way we count our code words is by + + + align:start position:0% +the way we count our code words is by +ranging through all the possible two to + + align:start position:0% +ranging through all the possible two to + + + align:start position:0% +ranging through all the possible two to +the k + + align:start position:0% +the k + + + align:start position:0% +the k +right so we've got to flip bits in the + + align:start position:0% +right so we've got to flip bits in the + + + align:start position:0% +right so we've got to flip bits in the +data section to get to another code word + + align:start position:0% +data section to get to another code word + + + align:start position:0% +data section to get to another code word +so we're + + align:start position:0% +so we're + + + align:start position:0% +so we're +saying we have a code word corresponding + + align:start position:0% +saying we have a code word corresponding + + + align:start position:0% +saying we have a code word corresponding +to some set of data bits + + align:start position:0% +to some set of data bits + + + align:start position:0% +to some set of data bits +we'll flip a bit there and then look to + + align:start position:0% +we'll flip a bit there and then look to + + + align:start position:0% +we'll flip a bit there and then look to +see what happens + + align:start position:0% +see what happens + + + align:start position:0% +see what happens +okay + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +here's a little modification to the code + + align:start position:0% +here's a little modification to the code + + + align:start position:0% +here's a little modification to the code +which actually puts in an overall parity + + align:start position:0% +which actually puts in an overall parity + + + align:start position:0% +which actually puts in an overall parity +bit + + align:start position:0% +bit + + + align:start position:0% +bit +p here so what this is is the sum of + + align:start position:0% +p here so what this is is the sum of + + + align:start position:0% +p here so what this is is the sum of +all the entries and every other position + + align:start position:0% + + + + align:start position:0% + +okay and if you go through + + align:start position:0% +okay and if you go through + + + align:start position:0% +okay and if you go through +the argument there what you'll discover + + align:start position:0% +the argument there what you'll discover + + + align:start position:0% +the argument there what you'll discover +is what you've done + + align:start position:0% +is what you've done + + + align:start position:0% +is what you've done +is go from uh do i still have it on the + + align:start position:0% +is go from uh do i still have it on the + + + align:start position:0% +is go from uh do i still have it on the +board i might have it on the board here + + align:start position:0% + + + + align:start position:0% + +no what you've done is go from the + + align:start position:0% +no what you've done is go from the + + + align:start position:0% +no what you've done is go from the +rectangular code + + align:start position:0% +rectangular code + + + align:start position:0% +rectangular code +that had this structure having distance + + align:start position:0% +that had this structure having distance + + + align:start position:0% +that had this structure having distance +three + + align:start position:0% + + + + align:start position:0% + +to now one that has hamming distance + + align:start position:0% +to now one that has hamming distance + + + align:start position:0% +to now one that has hamming distance +four + + align:start position:0% + + + + align:start position:0% + +okay so adding that overall parity bit + + align:start position:0% +okay so adding that overall parity bit + + + align:start position:0% +okay so adding that overall parity bit +has increased the minimum hamming + + align:start position:0% +has increased the minimum hamming + + + align:start position:0% +has increased the minimum hamming +distance of the code from three to four + + align:start position:0% +distance of the code from three to four + + + align:start position:0% +distance of the code from three to four +uh does that improve error correction + + align:start position:0% +uh does that improve error correction + + + align:start position:0% +uh does that improve error correction +capabilities + + align:start position:0% +capabilities + + + align:start position:0% +capabilities +you still can only correct up to one + + align:start position:0% +you still can only correct up to one + + + align:start position:0% +you still can only correct up to one +error but the difference now is that if + + align:start position:0% +error but the difference now is that if + + + align:start position:0% +error but the difference now is that if +you get two errors you can actually + + align:start position:0% +you get two errors you can actually + + + align:start position:0% +you get two errors you can actually +detect it accurately as + + align:start position:0% +detect it accurately as + + + align:start position:0% +detect it accurately as +a two-bit error okay + + align:start position:0% + + + + align:start position:0% + +all right so i'll leave you to go + + align:start position:0% +all right so i'll leave you to go + + + align:start position:0% +all right so i'll leave you to go +through that + + align:start position:0% +through that + + + align:start position:0% +through that +analysis this we've + + align:start position:0% +analysis this we've + + + align:start position:0% +analysis this we've +pretty much done already this is just + + align:start position:0% +pretty much done already this is just + + + align:start position:0% +pretty much done already this is just +filled out the rest of the matrix you + + align:start position:0% +filled out the rest of the matrix you + + + align:start position:0% +filled out the rest of the matrix you +see that we filled out this column on + + align:start position:0% +see that we filled out this column on + + + align:start position:0% +see that we filled out this column on +the board + + align:start position:0% +the board + + + align:start position:0% +the board +that was this case + + align:start position:0% + + + + align:start position:0% + +but you can actually fill them all out + + align:start position:0% +but you can actually fill them all out + + + align:start position:0% +but you can actually fill them all out +uh once you have the uh + + align:start position:0% +uh once you have the uh + + + align:start position:0% +uh once you have the uh +description of the parity check bits + + align:start position:0% +description of the parity check bits + + + align:start position:0% +description of the parity check bits +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +these are the columns you can fill out + + align:start position:0% +these are the columns you can fill out + + + align:start position:0% +these are the columns you can fill out +similarly and this is for the case of + + align:start position:0% +similarly and this is for the case of + + + align:start position:0% +similarly and this is for the case of +let's see what case is it referring to + + align:start position:0% +let's see what case is it referring to + + + align:start position:0% +let's see what case is it referring to +here + + align:start position:0% + + + + align:start position:0% + +uh any n equals three + + align:start position:0% +uh any n equals three + + + align:start position:0% +uh any n equals three +let's see sorry n equals nine + + align:start position:0% +let's see sorry n equals nine + + + align:start position:0% +let's see sorry n equals nine +uh k equals four d equals four so what + + align:start position:0% +uh k equals four d equals four so what + + + align:start position:0% +uh k equals four d equals four so what +uh rectangular picture am i talking + + align:start position:0% +uh rectangular picture am i talking + + + align:start position:0% +uh rectangular picture am i talking +about here + + align:start position:0% +about here + + + align:start position:0% +about here +this is rectangular code what + + align:start position:0% +this is rectangular code what + + + align:start position:0% +this is rectangular code what +rectangular code has these parameters + + align:start position:0% + + + + align:start position:0% + +so i must be talking about two by two + + align:start position:0% +so i must be talking about two by two + + + align:start position:0% +so i must be talking about two by two +for the data bits + + align:start position:0% +for the data bits + + + align:start position:0% +for the data bits +two rows two columns and then one + + align:start position:0% +two rows two columns and then one + + + align:start position:0% +two rows two columns and then one +overall + + align:start position:0% +overall + + + align:start position:0% +overall +right the overall + + align:start position:0% +right the overall + + + align:start position:0% +right the overall +what gives me the clue is i've got a + + align:start position:0% +what gives me the clue is i've got a + + + align:start position:0% +what gives me the clue is i've got a +minimum distance of four if it's a + + align:start position:0% +minimum distance of four if it's a + + + align:start position:0% +minimum distance of four if it's a +rectangular code with minimum distance + + align:start position:0% +rectangular code with minimum distance + + + align:start position:0% +rectangular code with minimum distance +four then i know i must have an overall + + align:start position:0% +four then i know i must have an overall + + + align:start position:0% +four then i know i must have an overall +parity bit + + align:start position:0% +parity bit + + + align:start position:0% +parity bit +um k is four because i just have + + align:start position:0% +um k is four because i just have + + + align:start position:0% +um k is four because i just have +um four data bits and + + align:start position:0% +um four data bits and + + + align:start position:0% +um four data bits and +overall i've got to send uh nine bits + + align:start position:0% +overall i've got to send uh nine bits + + + align:start position:0% +overall i've got to send uh nine bits +in each block okay + + align:start position:0% + + + + align:start position:0% + +so for that particular case this is what + + align:start position:0% +so for that particular case this is what + + + align:start position:0% +so for that particular case this is what +the + + align:start position:0% +the + + + align:start position:0% +the +matrix looks like so the only difference + + align:start position:0% +matrix looks like so the only difference + + + align:start position:0% +matrix looks like so the only difference +is there's an overall parity bit + + align:start position:0% +is there's an overall parity bit + + + align:start position:0% +is there's an overall parity bit +here p5 which is the sum of all the data + + align:start position:0% +here p5 which is the sum of all the data + + + align:start position:0% +here p5 which is the sum of all the data +bits + + align:start position:0% + + + + align:start position:0% + +actually all the data bits and the + + align:start position:0% +actually all the data bits and the + + + align:start position:0% +actually all the data bits and the +parity bits but this is what it + + align:start position:0% +parity bits but this is what it + + + align:start position:0% +parity bits but this is what it +works out to be okay + + align:start position:0% + + + + align:start position:0% + +and we've pretty much talked through the + + align:start position:0% +and we've pretty much talked through the + + + align:start position:0% +and we've pretty much talked through the +decoding here it's + + align:start position:0% +decoding here it's + + + align:start position:0% +decoding here it's +let me put it all up there + + align:start position:0% + + + + align:start position:0% + +so you calculate all the parity bits if + + align:start position:0% +so you calculate all the parity bits if + + + align:start position:0% +so you calculate all the parity bits if +you see no parity errors you return + + align:start position:0% +you see no parity errors you return + + + align:start position:0% +you see no parity errors you return +all the data bits if you detect a + + align:start position:0% +all the data bits if you detect a + + + align:start position:0% +all the data bits if you detect a +row or column parity bit error then you + + align:start position:0% +row or column parity bit error then you + + + align:start position:0% +row or column parity bit error then you +um then you make the change in that + + align:start position:0% +um then you make the change in that + + + align:start position:0% +um then you make the change in that +particular position + + align:start position:0% +particular position + + + align:start position:0% +particular position +and otherwise you flag an uncorrectable + + align:start position:0% +and otherwise you flag an uncorrectable + + + align:start position:0% +and otherwise you flag an uncorrectable +error so the correction is + + align:start position:0% +error so the correction is + + + align:start position:0% +error so the correction is +straightforward + + align:start position:0% +straightforward + + + align:start position:0% +straightforward +if you look on the slides later you'll + + align:start position:0% +if you look on the slides later you'll + + + align:start position:0% +if you look on the slides later you'll +see a little quiz that you can try for + + align:start position:0% +see a little quiz that you can try for + + + align:start position:0% +see a little quiz that you can try for +yourselves or you might try it in + + align:start position:0% +yourselves or you might try it in + + + align:start position:0% +yourselves or you might try it in +recitation + + align:start position:0% +recitation + + + align:start position:0% +recitation +but let me pass on that + + align:start position:0% + + + + align:start position:0% + +okay so the question arises is a + + align:start position:0% +okay so the question arises is a + + + align:start position:0% +okay so the question arises is a +rectangular code using this redundant + + align:start position:0% +rectangular code using this redundant + + + align:start position:0% +rectangular code using this redundant +information in an efficient way + + align:start position:0% + + + + align:start position:0% + +or could we do better + + align:start position:0% + + + + align:start position:0% + +so let's see we've got a code word that + + align:start position:0% +so let's see we've got a code word that + + + align:start position:0% +so let's see we've got a code word that +has + + align:start position:0% + + + + align:start position:0% + +uh that's got k message bits and then + + align:start position:0% +uh that's got k message bits and then + + + align:start position:0% +uh that's got k message bits and then +it's got + + align:start position:0% +it's got + + + align:start position:0% +it's got +n minus k parity bits okay so here's the + + align:start position:0% +n minus k parity bits okay so here's the + + + align:start position:0% +n minus k parity bits okay so here's the +data bits here's the parity bits + + align:start position:0% +data bits here's the parity bits + + + align:start position:0% +data bits here's the parity bits +we want to use the parity bits as + + align:start position:0% +we want to use the parity bits as + + + align:start position:0% +we want to use the parity bits as +effectively as possible + + align:start position:0% + + + + align:start position:0% + +how many different conditions can we + + align:start position:0% +how many different conditions can we + + + align:start position:0% +how many different conditions can we +signal if we have + + align:start position:0% +signal if we have + + + align:start position:0% +signal if we have +p bits that can only take value zero one + + align:start position:0% + + + + align:start position:0% + +just two to the n minus k conditions + + align:start position:0% +just two to the n minus k conditions + + + align:start position:0% +just two to the n minus k conditions +right so if we're looking at the code + + align:start position:0% +right so if we're looking at the code + + + align:start position:0% +right so if we're looking at the code +word + + align:start position:0% +word + + + align:start position:0% +word +and trying to deduce something from the + + align:start position:0% +and trying to deduce something from the + + + align:start position:0% +and trying to deduce something from the +parity bits + + align:start position:0% +parity bits + + + align:start position:0% +parity bits +how many different things can we deduce + + align:start position:0% +how many different things can we deduce + + + align:start position:0% +how many different things can we deduce +well n minus k bits can signal + + align:start position:0% +well n minus k bits can signal + + + align:start position:0% +well n minus k bits can signal +2 to the n minus k different things + + align:start position:0% +2 to the n minus k different things + + + align:start position:0% +2 to the n minus k different things +right + + align:start position:0% +right + + + align:start position:0% +right +what do they have to signal what do the + + align:start position:0% +what do they have to signal what do the + + + align:start position:0% +what do they have to signal what do the +parity bits have to tell us + + align:start position:0% +parity bits have to tell us + + + align:start position:0% +parity bits have to tell us +they have to tell us either that an + + align:start position:0% +they have to tell us either that an + + + align:start position:0% +they have to tell us either that an +error didn't occur + + align:start position:0% +error didn't occur + + + align:start position:0% +error didn't occur +or that an error occurred in the first + + align:start position:0% +or that an error occurred in the first + + + align:start position:0% +or that an error occurred in the first +position or second position or third all + + align:start position:0% +position or second position or third all + + + align:start position:0% +position or second position or third all +the way up to the nth + + align:start position:0% +the way up to the nth + + + align:start position:0% +the way up to the nth +so the number of things we want to learn + + align:start position:0% +so the number of things we want to learn + + + align:start position:0% +so the number of things we want to learn +from the parity bits is n plus one + + align:start position:0% +from the parity bits is n plus one + + + align:start position:0% +from the parity bits is n plus one +so you would hope uh that + + align:start position:0% + + + + align:start position:0% + +that this is true that the number of + + align:start position:0% +that this is true that the number of + + + align:start position:0% +that this is true that the number of +things you can signal with the parity + + align:start position:0% +things you can signal with the parity + + + align:start position:0% +things you can signal with the parity +bits + + align:start position:0% +bits + + + align:start position:0% +bits +is at least equal to the number of + + align:start position:0% +is at least equal to the number of + + + align:start position:0% +is at least equal to the number of +things you want to get in the case of + + align:start position:0% +things you want to get in the case of + + + align:start position:0% +things you want to get in the case of +single error correction all right we're + + align:start position:0% +single error correction all right we're + + + align:start position:0% +single error correction all right we're +only trying to + + align:start position:0% +only trying to + + + align:start position:0% +only trying to +correct a single error here so we want + + align:start position:0% +correct a single error here so we want + + + align:start position:0% +correct a single error here so we want +the number of possibilities that the + + align:start position:0% +the number of possibilities that the + + + align:start position:0% +the number of possibilities that the +parity bits can indicate + + align:start position:0% +parity bits can indicate + + + align:start position:0% +parity bits can indicate +to include the case of no errors that's + + align:start position:0% +to include the case of no errors that's + + + align:start position:0% +to include the case of no errors that's +the one over there + + align:start position:0% +the one over there + + + align:start position:0% +the one over there +plus the case of an error in the first + + align:start position:0% +plus the case of an error in the first + + + align:start position:0% +plus the case of an error in the first +position or second position or third + + align:start position:0% +position or second position or third + + + align:start position:0% +position or second position or third +position and so on + + align:start position:0% +position and so on + + + align:start position:0% +position and so on +okay if you uh plug in the typical + + align:start position:0% +okay if you uh plug in the typical + + + align:start position:0% +okay if you uh plug in the typical +parameters + + align:start position:0% +parameters + + + align:start position:0% +parameters +for the rectangular code you'll see that + + align:start position:0% +for the rectangular code you'll see that + + + align:start position:0% +for the rectangular code you'll see that +you're actually exceeding this wildly + + align:start position:0% +you're actually exceeding this wildly + + + align:start position:0% +you're actually exceeding this wildly +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +for that particular case nine four four + + align:start position:0% +for that particular case nine four four + + + align:start position:0% +for that particular case nine four four +what do we have we have nine plus one + + align:start position:0% +what do we have we have nine plus one + + + align:start position:0% +what do we have we have nine plus one +on this side and we have two to the what + + align:start position:0% + + + + align:start position:0% + +nine minus four + + align:start position:0% +nine minus four + + + align:start position:0% +nine minus four +so what's that 32 on the right hand side + + align:start position:0% +so what's that 32 on the right hand side + + + align:start position:0% +so what's that 32 on the right hand side +and 10 on the left + + align:start position:0% +and 10 on the left + + + align:start position:0% +and 10 on the left +so you've got a big gap if you were + + align:start position:0% +so you've got a big gap if you were + + + align:start position:0% +so you've got a big gap if you were +going to allow me + + align:start position:0% + + + + align:start position:0% + +one two three four five parity bits i + + align:start position:0% +one two three four five parity bits i + + + align:start position:0% +one two three four five parity bits i +could do a lot more than tell you + + align:start position:0% +could do a lot more than tell you + + + align:start position:0% +could do a lot more than tell you +what you're asking me to tell you from + + align:start position:0% +what you're asking me to tell you from + + + align:start position:0% +what you're asking me to tell you from +this uh in this particular code so i'm + + align:start position:0% +this uh in this particular code so i'm + + + align:start position:0% +this uh in this particular code so i'm +not using the parity bits as efficiently + + align:start position:0% +not using the parity bits as efficiently + + + align:start position:0% +not using the parity bits as efficiently +as i could + + align:start position:0% +as i could + + + align:start position:0% +as i could +and that motivates the search for um + + align:start position:0% +and that motivates the search for um + + + align:start position:0% +and that motivates the search for um +for better choices so this is a + + align:start position:0% +for better choices so this is a + + + align:start position:0% +for better choices so this is a +fundamental + + align:start position:0% +fundamental + + + align:start position:0% +fundamental +inequality here uh something we'll keep + + align:start position:0% +inequality here uh something we'll keep + + + align:start position:0% +inequality here uh something we'll keep +referring back to + + align:start position:0% +referring back to + + + align:start position:0% +referring back to +so make sure you understand where that + + align:start position:0% +so make sure you understand where that + + + align:start position:0% +so make sure you understand where that +comes from + + align:start position:0% +comes from + + + align:start position:0% +comes from +and that leads us to what are called + + align:start position:0% +and that leads us to what are called + + + align:start position:0% +and that leads us to what are called +hamming codes so hamming codes + + align:start position:0% +hamming codes so hamming codes + + + align:start position:0% +hamming codes so hamming codes +are codes that actually use the parity + + align:start position:0% +are codes that actually use the parity + + + align:start position:0% +are codes that actually use the parity +bits uh + + align:start position:0% +bits uh + + + align:start position:0% +bits uh +efficiently in that they match this + + align:start position:0% +efficiently in that they match this + + + align:start position:0% +efficiently in that they match this +bound with equality + + align:start position:0% + + + + align:start position:0% + +okay so can you think of the smallest + + align:start position:0% +okay so can you think of the smallest + + + align:start position:0% +okay so can you think of the smallest +k n pair that's going to satisfy this + + align:start position:0% +k n pair that's going to satisfy this + + + align:start position:0% +k n pair that's going to satisfy this +with equality + + align:start position:0% +with equality + + + align:start position:0% +with equality +just playing with some small numbers + + align:start position:0% + + + + align:start position:0% + +maybe i shouldn't play this game since + + align:start position:0% +maybe i shouldn't play this game since + + + align:start position:0% +maybe i shouldn't play this game since +we're late in the lecture + + align:start position:0% +we're late in the lecture + + + align:start position:0% +we're late in the lecture +here's a suggestion okay nkd + + align:start position:0% +here's a suggestion okay nkd + + + align:start position:0% +here's a suggestion okay nkd +the hamming code is going to be a single + + align:start position:0% +the hamming code is going to be a single + + + align:start position:0% +the hamming code is going to be a single +error correcting code with having this + + align:start position:0% +error correcting code with having this + + + align:start position:0% +error correcting code with having this +minimum + + align:start position:0% +minimum + + + align:start position:0% +minimum +having distance three so the three will + + align:start position:0% +having distance three so the three will + + + align:start position:0% +having distance three so the three will +always be there + + align:start position:0% +always be there + + + align:start position:0% +always be there +this is n and this is k and you'll see + + align:start position:0% +this is n and this is k and you'll see + + + align:start position:0% +this is n and this is k and you'll see +that this is satisfied with the quality + + align:start position:0% +that this is satisfied with the quality + + + align:start position:0% +that this is satisfied with the quality +but there are other choices this is the + + align:start position:0% +but there are other choices this is the + + + align:start position:0% +but there are other choices this is the +smallest choice the smallest non-trivial + + align:start position:0% +smallest choice the smallest non-trivial + + + align:start position:0% +smallest choice the smallest non-trivial +choice anyway + + align:start position:0% +choice anyway + + + align:start position:0% +choice anyway +but you can go to more general + + align:start position:0% +but you can go to more general + + + align:start position:0% +but you can go to more general +possibilities so this code is called a + + align:start position:0% +possibilities so this code is called a + + + align:start position:0% +possibilities so this code is called a +perfect code + + align:start position:0% +perfect code + + + align:start position:0% +perfect code +because it matches uh that inequality + + align:start position:0% +because it matches uh that inequality + + + align:start position:0% +because it matches uh that inequality +with equality but actually that doesn't + + align:start position:0% +with equality but actually that doesn't + + + align:start position:0% +with equality but actually that doesn't +necessarily mean it's a + + align:start position:0% +necessarily mean it's a + + + align:start position:0% +necessarily mean it's a +it's the best code it turns out to be a + + align:start position:0% +it's the best code it turns out to be a + + + align:start position:0% +it's the best code it turns out to be a +good code provided + + align:start position:0% +good code provided + + + align:start position:0% +good code provided +you're picking these parameters + + align:start position:0% +you're picking these parameters + + + align:start position:0% +you're picking these parameters +appropriately for your application + + align:start position:0% +appropriately for your application + + + align:start position:0% +appropriately for your application +uh but this is perfect code in a very + + align:start position:0% +uh but this is perfect code in a very + + + align:start position:0% +uh but this is perfect code in a very +technical sense meaning + + align:start position:0% +technical sense meaning + + + align:start position:0% +technical sense meaning +it's a code that attains this inequality + + align:start position:0% +it's a code that attains this inequality + + + align:start position:0% +it's a code that attains this inequality +with equality okay that's all that it + + align:start position:0% +with equality okay that's all that it + + + align:start position:0% +with equality okay that's all that it +means there + + align:start position:0% +means there + + + align:start position:0% +means there +okay so what's the idea on the hamming + + align:start position:0% +okay so what's the idea on the hamming + + + align:start position:0% +okay so what's the idea on the hamming +code + + align:start position:0% + + + + align:start position:0% + +let's let me put it all down there and + + align:start position:0% +let's let me put it all down there and + + + align:start position:0% +let's let me put it all down there and +then we'll talk through it so the uh + + align:start position:0% +then we'll talk through it so the uh + + + align:start position:0% +then we'll talk through it so the uh +this little + + align:start position:0% +this little + + + align:start position:0% +this little +venn diagram uh + + align:start position:0% +venn diagram uh + + + align:start position:0% +venn diagram uh +conveys for you how the parity bits are + + align:start position:0% +conveys for you how the parity bits are + + + align:start position:0% +conveys for you how the parity bits are +picked + + align:start position:0% +picked + + + align:start position:0% +picked +and they end up actually being picked in + + align:start position:0% +and they end up actually being picked in + + + align:start position:0% +and they end up actually being picked in +a very efficient way to provide the + + align:start position:0% +a very efficient way to provide the + + + align:start position:0% +a very efficient way to provide the +coverage you want so this is the case + + align:start position:0% +coverage you want so this is the case + + + align:start position:0% +coverage you want so this is the case +that was mentioned before this is the + + align:start position:0% +that was mentioned before this is the + + + align:start position:0% +that was mentioned before this is the +um what was it + + align:start position:0% +um what was it + + + align:start position:0% +um what was it +743 that what you had + + align:start position:0% + + + + align:start position:0% + +yeah the 743 code right + + align:start position:0% + + + + align:start position:0% + +so let's uh give ourselves some space + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +so with three parity bits we're actually + + align:start position:0% +so with three parity bits we're actually + + + align:start position:0% +so with three parity bits we're actually +going to indicate + + align:start position:0% +going to indicate + + + align:start position:0% +going to indicate +whether there was zero error or whether + + align:start position:0% +whether there was zero error or whether + + + align:start position:0% +whether there was zero error or whether +the error occurred in the first + + align:start position:0% +the error occurred in the first + + + align:start position:0% +the error occurred in the first +first position second position and so on + + align:start position:0% +first position second position and so on + + + align:start position:0% +first position second position and so on +all the way up to uh the seventh + + align:start position:0% +all the way up to uh the seventh + + + align:start position:0% +all the way up to uh the seventh +position so we're going to use three + + align:start position:0% +position so we're going to use three + + + align:start position:0% +position so we're going to use three +bits + + align:start position:0% +bits + + + align:start position:0% +bits +three parity bits to indicate eight + + align:start position:0% +three parity bits to indicate eight + + + align:start position:0% +three parity bits to indicate eight +possibilities which is + + align:start position:0% +possibilities which is + + + align:start position:0% +possibilities which is +what we know you should be able to do + + align:start position:0% +what we know you should be able to do + + + align:start position:0% +what we know you should be able to do +and here's the arrangement this picture + + align:start position:0% +and here's the arrangement this picture + + + align:start position:0% +and here's the arrangement this picture +conveys it so basically + + align:start position:0% +conveys it so basically + + + align:start position:0% +conveys it so basically +p1 is d1 plus d2 plus d4 + + align:start position:0% +p1 is d1 plus d2 plus d4 + + + align:start position:0% +p1 is d1 plus d2 plus d4 +so p1 fires if d1 d2 or d4 + + align:start position:0% +so p1 fires if d1 d2 or d4 + + + align:start position:0% +so p1 fires if d1 d2 or d4 +or if any one of those is one and + + align:start position:0% +or if any one of those is one and + + + align:start position:0% +or if any one of those is one and +similarly for these other things okay so + + align:start position:0% +similarly for these other things okay so + + + align:start position:0% +similarly for these other things okay so +this picture tells you what data bits + + align:start position:0% +this picture tells you what data bits + + + align:start position:0% +this picture tells you what data bits +are included in the coverage of each + + align:start position:0% +are included in the coverage of each + + + align:start position:0% +are included in the coverage of each +parity bit okay so that's the way to + + align:start position:0% +parity bit okay so that's the way to + + + align:start position:0% +parity bit okay so that's the way to +think of what this picture is + + align:start position:0% +think of what this picture is + + + align:start position:0% +think of what this picture is +so these are apportioned carefully + + align:start position:0% +so these are apportioned carefully + + + align:start position:0% +so these are apportioned carefully +so for instance let's see if you + + align:start position:0% +so for instance let's see if you + + + align:start position:0% +so for instance let's see if you +discover that p1 + + align:start position:0% +discover that p1 + + + align:start position:0% +discover that p1 +and p3 indicate an error that means some + + align:start position:0% +and p3 indicate an error that means some + + + align:start position:0% +and p3 indicate an error that means some +data bit in the coverage of p1 + + align:start position:0% +data bit in the coverage of p1 + + + align:start position:0% +data bit in the coverage of p1 +and in the coverage of p3 um + + align:start position:0% +and in the coverage of p3 um + + + align:start position:0% +and in the coverage of p3 um +have an error + + align:start position:0% + + + + align:start position:0% + +but p2 didn't have an error okay so what + + align:start position:0% +but p2 didn't have an error okay so what + + + align:start position:0% +but p2 didn't have an error okay so what +does that tell you + + align:start position:0% +does that tell you + + + align:start position:0% +does that tell you +we're only considering up to single + + align:start position:0% +we're only considering up to single + + + align:start position:0% +we're only considering up to single +errors + + align:start position:0% +errors + + + align:start position:0% +errors +if p1 and p3 have an error but p2 + + align:start position:0% +if p1 and p3 have an error but p2 + + + align:start position:0% +if p1 and p3 have an error but p2 +doesn't have an error + + align:start position:0% +doesn't have an error + + + align:start position:0% +doesn't have an error +well p1 and p3 share d2d4 + + align:start position:0% +well p1 and p3 share d2d4 + + + align:start position:0% +well p1 and p3 share d2d4 +but p2 didn't have an error so d4 must + + align:start position:0% +but p2 didn't have an error so d4 must + + + align:start position:0% +but p2 didn't have an error so d4 must +be fined so d2 must be the one that's an + + align:start position:0% +be fined so d2 must be the one that's an + + + align:start position:0% +be fined so d2 must be the one that's an +error + + align:start position:0% +error + + + align:start position:0% +error +okay and so you get full coverage by + + align:start position:0% +okay and so you get full coverage by + + + align:start position:0% +okay and so you get full coverage by +that kind of reasoning + + align:start position:0% + + + + align:start position:0% + +one way to think of this and this is + + align:start position:0% +one way to think of this and this is + + + align:start position:0% +one way to think of this and this is +actually how hamming set it up + + align:start position:0% +actually how hamming set it up + + + align:start position:0% +actually how hamming set it up +was he actually arranged the + + align:start position:0% +was he actually arranged the + + + align:start position:0% +was he actually arranged the +parity bits and the data bits a little + + align:start position:0% +parity bits and the data bits a little + + + align:start position:0% +parity bits and the data bits a little +differently down that + + align:start position:0% +differently down that + + + align:start position:0% +differently down that +uh code word he had parity bit one + + align:start position:0% +uh code word he had parity bit one + + + align:start position:0% +uh code word he had parity bit one +in the first position parity bit two in + + align:start position:0% +in the first position parity bit two in + + + align:start position:0% +in the first position parity bit two in +the second position + + align:start position:0% +the second position + + + align:start position:0% +the second position +parity bit three in the fourth position + + align:start position:0% +parity bit three in the fourth position + + + align:start position:0% +parity bit three in the fourth position +if you had a long code word the next one + + align:start position:0% +if you had a long code word the next one + + + align:start position:0% +if you had a long code word the next one +would be in the eighth position + + align:start position:0% +would be in the eighth position + + + align:start position:0% +would be in the eighth position +so it's two to the zero two to the one + + align:start position:0% +so it's two to the zero two to the one + + + align:start position:0% +so it's two to the zero two to the one +two to the two two to the three and so + + align:start position:0% +two to the two two to the three and so + + + align:start position:0% +two to the two two to the three and so +on + + align:start position:0% +on + + + align:start position:0% +on +so those are the positions in which he + + align:start position:0% +so those are the positions in which he + + + align:start position:0% +so those are the positions in which he +puts the parity bits everywhere else + + align:start position:0% +puts the parity bits everywhere else + + + align:start position:0% +puts the parity bits everywhere else +are the data bits and then the + + align:start position:0% +are the data bits and then the + + + align:start position:0% +are the data bits and then the +data bits that feed into parity + + align:start position:0% +data bits that feed into parity + + + align:start position:0% +data bits that feed into parity +bit p1 or parity relation p1 + + align:start position:0% +bit p1 or parity relation p1 + + + align:start position:0% +bit p1 or parity relation p1 +are the data bits and positions that end + + align:start position:0% +are the data bits and positions that end + + + align:start position:0% +are the data bits and positions that end +with the one + + align:start position:0% +with the one + + + align:start position:0% +with the one +okay so if the positions end with a one + + align:start position:0% +okay so if the positions end with a one + + + align:start position:0% +okay so if the positions end with a one +you stick them in this + + align:start position:0% +you stick them in this + + + align:start position:0% +you stick them in this +in the coverage of this parity + + align:start position:0% +in the coverage of this parity + + + align:start position:0% +in the coverage of this parity +relationship so d1 + + align:start position:0% +relationship so d1 + + + align:start position:0% +relationship so d1 +d2 not d3 but d4 + + align:start position:0% +d2 not d3 but d4 + + + align:start position:0% +d2 not d3 but d4 +uh for p2 similarly if if um a parity + + align:start position:0% +uh for p2 similarly if if um a parity + + + align:start position:0% +uh for p2 similarly if if um a parity +relation uh sorry + + align:start position:0% +relation uh sorry + + + align:start position:0% +relation uh sorry +the parity relation p2 includes the data + + align:start position:0% +the parity relation p2 includes the data + + + align:start position:0% +the parity relation p2 includes the data +bits that have a one and their second + + align:start position:0% +bits that have a one and their second + + + align:start position:0% +bits that have a one and their second +position so + + align:start position:0% +position so + + + align:start position:0% +position so +d1 not d2 yes d3 nesd4 + + align:start position:0% +d1 not d2 yes d3 nesd4 + + + align:start position:0% +d1 not d2 yes d3 nesd4 +okay so the nice thing about that is + + align:start position:0% +okay so the nice thing about that is + + + align:start position:0% +okay so the nice thing about that is +that when you get a particular + + align:start position:0% +that when you get a particular + + + align:start position:0% +that when you get a particular +um pattern of errors it actually leads + + align:start position:0% +um pattern of errors it actually leads + + + align:start position:0% +um pattern of errors it actually leads +you + + align:start position:0% +you + + + align:start position:0% +you +exactly to the right position in the + + align:start position:0% + + + + align:start position:0% + +in the code word so i don't want to + + align:start position:0% +in the code word so i don't want to + + + align:start position:0% +in the code word so i don't want to +actually spend a lot of time here i want + + align:start position:0% +actually spend a lot of time here i want + + + align:start position:0% +actually spend a lot of time here i want +you to + + align:start position:0% +you to + + + align:start position:0% +you to +look at that separately but + + align:start position:0% +look at that separately but + + + align:start position:0% +look at that separately but +just to go over the process here's what + + align:start position:0% +just to go over the process here's what + + + align:start position:0% +just to go over the process here's what +happens + + align:start position:0% +happens + + + align:start position:0% +happens +we know that parity bit p1 was d1 plus + + align:start position:0% +we know that parity bit p1 was d1 plus + + + align:start position:0% +we know that parity bit p1 was d1 plus +d2 plus d4 + + align:start position:0% +d2 plus d4 + + + align:start position:0% +d2 plus d4 +so we know that this parity relationship + + align:start position:0% +so we know that this parity relationship + + + align:start position:0% +so we know that this parity relationship +was satisfied at the transmitting end + + align:start position:0% +was satisfied at the transmitting end + + + align:start position:0% +was satisfied at the transmitting end +by the time you receive all of this all + + align:start position:0% +by the time you receive all of this all + + + align:start position:0% +by the time you receive all of this all +of it might have been corrupted that's + + align:start position:0% +of it might have been corrupted that's + + + align:start position:0% +of it might have been corrupted that's +why i put a little primes next to these + + align:start position:0% +why i put a little primes next to these + + + align:start position:0% +why i put a little primes next to these +not all of them but one of them may have + + align:start position:0% +not all of them but one of them may have + + + align:start position:0% +not all of them but one of them may have +been we're limiting ourselves to single + + align:start position:0% +been we're limiting ourselves to single + + + align:start position:0% +been we're limiting ourselves to single +error correction okay + + align:start position:0% +error correction okay + + + align:start position:0% +error correction okay +so the d1 may not be the d1 prime may + + align:start position:0% +so the d1 may not be the d1 prime may + + + align:start position:0% +so the d1 may not be the d1 prime may +not be d1 because of an error + + align:start position:0% +not be d1 because of an error + + + align:start position:0% +not be d1 because of an error +so what you do is you compute these + + align:start position:0% +so what you do is you compute these + + + align:start position:0% +so what you do is you compute these +so-called syndrome bits + + align:start position:0% +so-called syndrome bits + + + align:start position:0% +so-called syndrome bits +okay if there were no errors then e1 + + align:start position:0% +okay if there were no errors then e1 + + + align:start position:0% +okay if there were no errors then e1 +should be zero e2 should be zero e3 + + align:start position:0% +should be zero e2 should be zero e3 + + + align:start position:0% +should be zero e2 should be zero e3 +should be zero because that's how it was + + align:start position:0% +should be zero because that's how it was + + + align:start position:0% +should be zero because that's how it was +at the other end + + align:start position:0% +at the other end + + + align:start position:0% +at the other end +if there's a single error in one of the + + align:start position:0% +if there's a single error in one of the + + + align:start position:0% +if there's a single error in one of the +bits covered by the appropriate + + align:start position:0% +bits covered by the appropriate + + + align:start position:0% +bits covered by the appropriate +relationship you're going to get the + + align:start position:0% +relationship you're going to get the + + + align:start position:0% +relationship you're going to get the +associated + + align:start position:0% +associated + + + align:start position:0% +associated +syndrome bit going to one so you compute + + align:start position:0% +syndrome bit going to one so you compute + + + align:start position:0% +syndrome bit going to one so you compute +these syndromes + + align:start position:0% +these syndromes + + + align:start position:0% +these syndromes +and then line them up as a binary number + + align:start position:0% +and then line them up as a binary number + + + align:start position:0% +and then line them up as a binary number +and it turns out that depending on the + + align:start position:0% +and it turns out that depending on the + + + align:start position:0% +and it turns out that depending on the +pattern and the syndromes + + align:start position:0% +pattern and the syndromes + + + align:start position:0% +pattern and the syndromes +it'll tell you exactly the position in + + align:start position:0% +it'll tell you exactly the position in + + + align:start position:0% +it'll tell you exactly the position in +the code word in which + + align:start position:0% +the code word in which + + + align:start position:0% +the code word in which +there's an error so it's kind of cute + + align:start position:0% +there's an error so it's kind of cute + + + align:start position:0% +there's an error so it's kind of cute +and powerful + + align:start position:0% +and powerful + + + align:start position:0% +and powerful +you can correct up to t errors and + + align:start position:0% +you can correct up to t errors and + + + align:start position:0% +you can correct up to t errors and +there's a natural relationship + + align:start position:0% +there's a natural relationship + + + align:start position:0% +there's a natural relationship +that extends from this + + align:start position:0% + + + + align:start position:0% + +i wanted to make one final point which + + align:start position:0% +i wanted to make one final point which + + + align:start position:0% +i wanted to make one final point which +is that these error correcting codes + + align:start position:0% +is that these error correcting codes + + + align:start position:0% +is that these error correcting codes +occur all over the place not just in the + + align:start position:0% +occur all over the place not just in the + + + align:start position:0% +occur all over the place not just in the +setting of binary + + align:start position:0% +setting of binary + + + align:start position:0% +setting of binary +and one thing you might try and do if + + align:start position:0% +and one thing you might try and do if + + + align:start position:0% +and one thing you might try and do if +you're carrying a textbook with you + + align:start position:0% +you're carrying a textbook with you + + + align:start position:0% +you're carrying a textbook with you +look at the isbn number the isbn number + + align:start position:0% +look at the isbn number the isbn number + + + align:start position:0% +look at the isbn number the isbn number +is a 10-digit number + + align:start position:0% +is a 10-digit number + + + align:start position:0% +is a 10-digit number +x1 up to x10 and it turns out that 1 + + align:start position:0% +x1 up to x10 and it turns out that 1 + + + align:start position:0% +x1 up to x10 and it turns out that 1 +times + + align:start position:0% +times + + + align:start position:0% +times +x1 plus 2 times x 2 + + align:start position:0% +x1 plus 2 times x 2 + + + align:start position:0% +x1 plus 2 times x 2 +plus 10 times x 10 + + align:start position:0% +plus 10 times x 10 + + + align:start position:0% +plus 10 times x 10 +is going to be 0 modulo 11. so try that + + align:start position:0% +is going to be 0 modulo 11. so try that + + + align:start position:0% +is going to be 0 modulo 11. so try that +out on the isp number of any book you're + + align:start position:0% +out on the isp number of any book you're + + + align:start position:0% +out on the isp number of any book you're +carrying + + align:start position:0% +carrying + + + align:start position:0% +carrying +what you'll see is that this is a parity + + align:start position:0% +what you'll see is that this is a parity + + + align:start position:0% +what you'll see is that this is a parity +relationship that guards against + + align:start position:0% +relationship that guards against + + + align:start position:0% +relationship that guards against +errors in any single any single isbn + + align:start position:0% +errors in any single any single isbn + + + align:start position:0% +errors in any single any single isbn +number + + align:start position:0% +number + + + align:start position:0% +number +or a transposition of two which turn out + + align:start position:0% +or a transposition of two which turn out + + + align:start position:0% +or a transposition of two which turn out +to be the two most natural + + align:start position:0% +to be the two most natural + + + align:start position:0% +to be the two most natural +errors okay look for parity relations in + + align:start position:0% +errors okay look for parity relations in + + + align:start position:0% +errors okay look for parity relations in +other places + + align:start position:0% +other places + + + align:start position:0% +other places +you \ No newline at end of file diff --git a/5tWsBNEeF1I.txt b/5tWsBNEeF1I.txt new file mode 100644 index 0000000000000000000000000000000000000000..265291edfc8593e1934ad609a80da53fb6bea060 --- /dev/null +++ b/5tWsBNEeF1I.txt @@ -0,0 +1,14347 @@ +align:start position:0% + +so today we are starting a new topic and + + align:start position:0% +so today we are starting a new topic and + + + align:start position:0% +so today we are starting a new topic and +we're going to be looking at radiation + + align:start position:0% +we're going to be looking at radiation + + + align:start position:0% +we're going to be looking at radiation +or self emission from the + + align:start position:0% +or self emission from the + + + align:start position:0% +or self emission from the +plasmas in a way this is like the + + align:start position:0% +plasmas in a way this is like the + + + align:start position:0% +plasmas in a way this is like the +natural language of the plasma + + align:start position:0% +natural language of the plasma + + + align:start position:0% +natural language of the plasma +previously we have surrounded it with + + align:start position:0% +previously we have surrounded it with + + + align:start position:0% +previously we have surrounded it with +Magnetic probes we prodded it with lar + + align:start position:0% +Magnetic probes we prodded it with lar + + + align:start position:0% +Magnetic probes we prodded it with lar +probes we fired various beams of lasers + + align:start position:0% +probes we fired various beams of lasers + + + align:start position:0% +probes we fired various beams of lasers +microwaves through it but now we're + + align:start position:0% +microwaves through it but now we're + + + align:start position:0% +microwaves through it but now we're +looking at what plasma produces itself + + align:start position:0% +looking at what plasma produces itself + + + align:start position:0% +looking at what plasma produces itself +as a way of trying to diagnose what's + + align:start position:0% +as a way of trying to diagnose what's + + + align:start position:0% +as a way of trying to diagnose what's +going and it's important to not of + + align:start position:0% +going and it's important to not of + + + align:start position:0% +going and it's important to not of +course plasmas are not special in this + + align:start position:0% +course plasmas are not special in this + + + align:start position:0% +course plasmas are not special in this +sent so all + + align:start position:0% +sent so all + + + align:start position:0% +sent so all +objects will + + align:start position:0% +objects will + + + align:start position:0% +objects will +emit electromagnetic + + align:start position:0% + + + + align:start position:0% + +radiation humans of + + align:start position:0% +radiation humans of + + + align:start position:0% +radiation humans of +course mostly in the + + align:start position:0% +course mostly in the + + + align:start position:0% +course mostly in the +IR Pocus when they get red hot famously + + align:start position:0% +IR Pocus when they get red hot famously + + + align:start position:0% +IR Pocus when they get red hot famously +glow different colors uh and of course + + align:start position:0% +glow different colors uh and of course + + + align:start position:0% +glow different colors uh and of course +the universe in the form of things like + + align:start position:0% +the universe in the form of things like + + + align:start position:0% +the universe in the form of things like +stars and black holes but even in the + + align:start position:0% +stars and black holes but even in the + + + align:start position:0% +stars and black holes but even in the +completely empty parts of the universe + + align:start position:0% +completely empty parts of the universe + + + align:start position:0% +completely empty parts of the universe +we still have the cosmic microwave + + align:start position:0% +we still have the cosmic microwave + + + align:start position:0% +we still have the cosmic microwave +background left over from The Big Bang + + align:start position:0% +background left over from The Big Bang + + + align:start position:0% +background left over from The Big Bang +rattling around and so even something + + align:start position:0% +rattling around and so even something + + + align:start position:0% +rattling around and so even something +that is as cold as out of space still + + align:start position:0% +that is as cold as out of space still + + + align:start position:0% +that is as cold as out of space still +has some radiation associated with it in + + align:start position:0% +has some radiation associated with it in + + + align:start position:0% +has some radiation associated with it in +general if we have an object which is + + align:start position:0% +general if we have an object which is + + + align:start position:0% +general if we have an object which is +hotter + + align:start position:0% + + + + align:start position:0% + +we get higher energy photons + + align:start position:0% + + + + align:start position:0% + +out so we could say higher frequency or + + align:start position:0% +out so we could say higher frequency or + + + align:start position:0% +out so we could say higher frequency or +energy which is just of course H Bar + + align:start position:0% +energy which is just of course H Bar + + + align:start position:0% +energy which is just of course H Bar +times the + + align:start position:0% + + + + align:start position:0% + +frequency photons out of it and so we + + align:start position:0% +frequency photons out of it and so we + + + align:start position:0% +frequency photons out of it and so we +might expect in the case of plasmas + + align:start position:0% +might expect in the case of plasmas + + + align:start position:0% +might expect in the case of plasmas +which are usually pretty + + align:start position:0% +which are usually pretty + + + align:start position:0% +which are usually pretty +hot that we would be able to get some + + align:start position:0% +hot that we would be able to get some + + + align:start position:0% +hot that we would be able to get some +pretty high energy photons and indeed + + align:start position:0% +pretty high energy photons and indeed + + + align:start position:0% +pretty high energy photons and indeed +plasmas t a Spam the gamma all the way + + align:start position:0% +plasmas t a Spam the gamma all the way + + + align:start position:0% +plasmas t a Spam the gamma all the way +from the radio + + align:start position:0% +from the radio + + + align:start position:0% +from the radio +frequency up to xrays and + + align:start position:0% +frequency up to xrays and + + + align:start position:0% +frequency up to xrays and +even gamma + + align:start position:0% + + + + align:start position:0% + +R so we're going to be trying to talk + + align:start position:0% +R so we're going to be trying to talk + + + align:start position:0% +R so we're going to be trying to talk +about radiation that spans different + + align:start position:0% +about radiation that spans different + + + align:start position:0% +about radiation that spans different +energy bands varying by many many orders + + align:start position:0% +energy bands varying by many many orders + + + align:start position:0% +energy bands varying by many many orders +of magnitude and just like when we + + align:start position:0% +of magnitude and just like when we + + + align:start position:0% +of magnitude and just like when we +talked about radiation sorry when we + + align:start position:0% +talked about radiation sorry when we + + + align:start position:0% +talked about radiation sorry when we +talked about the different plasmas we + + align:start position:0% +talked about the different plasmas we + + + align:start position:0% +talked about the different plasmas we +worked on at the start list class we saw + + align:start position:0% +worked on at the start list class we saw + + + align:start position:0% +worked on at the start list class we saw +there was a huge diversity here we're + + align:start position:0% +there was a huge diversity here we're + + + align:start position:0% +there was a huge diversity here we're +also dealing with a huge diversity so + + align:start position:0% +also dealing with a huge diversity so + + + align:start position:0% +also dealing with a huge diversity so +we're going to try and use a framework + + align:start position:0% +we're going to try and use a framework + + + align:start position:0% +we're going to try and use a framework +that treats all of these in a similar + + align:start position:0% +that treats all of these in a similar + + + align:start position:0% +that treats all of these in a similar +way but of course there will be some + + align:start position:0% +way but of course there will be some + + + align:start position:0% +way but of course there will be some +subtle details uh and at the end of the + + align:start position:0% +subtle details uh and at the end of the + + + align:start position:0% +subtle details uh and at the end of the +day some things are going to look more + + align:start position:0% +day some things are going to look more + + + align:start position:0% +day some things are going to look more +like radio waves where maybe you need to + + align:start position:0% +like radio waves where maybe you need to + + + align:start position:0% +like radio waves where maybe you need to +think more about the wave equation + + align:start position:0% +think more about the wave equation + + + align:start position:0% +think more about the wave equation +because the wavelength of the radiation + + align:start position:0% +because the wavelength of the radiation + + + align:start position:0% +because the wavelength of the radiation +is on the order of the size of your + + align:start position:0% +is on the order of the size of your + + + align:start position:0% +is on the order of the size of your +plasma and some things like X-rays and + + align:start position:0% +plasma and some things like X-rays and + + + align:start position:0% +plasma and some things like X-rays and +gamma rays are going to be up where the + + align:start position:0% +gamma rays are going to be up where the + + + align:start position:0% +gamma rays are going to be up where the +wavelength is so small compared to the + + align:start position:0% +wavelength is so small compared to the + + + align:start position:0% +wavelength is so small compared to the +size of our plasma that we can use like + + align:start position:0% +size of our plasma that we can use like + + + align:start position:0% +size of our plasma that we can use like +a Ray treatment instead so just keep in + + align:start position:0% +a Ray treatment instead so just keep in + + + align:start position:0% +a Ray treatment instead so just keep in +mind that we have different conceptual + + align:start position:0% +mind that we have different conceptual + + + align:start position:0% +mind that we have different conceptual +Frameworks dealing with em radiation and + + align:start position:0% +Frameworks dealing with em radiation and + + + align:start position:0% +Frameworks dealing with em radiation and +we may need to modify it a little bit + + align:start position:0% +we may need to modify it a little bit + + + align:start position:0% +we may need to modify it a little bit +depending on what we're dealing with now + + align:start position:0% +depending on what we're dealing with now + + + align:start position:0% +depending on what we're dealing with now +the fact that plasmas are hot and emit + + align:start position:0% +the fact that plasmas are hot and emit + + + align:start position:0% +the fact that plasmas are hot and emit +all of these uh different types of + + align:start position:0% +all of these uh different types of + + + align:start position:0% +all of these uh different types of +radiation has two consequences first of + + align:start position:0% +radiation has two consequences first of + + + align:start position:0% +radiation has two consequences first of +all this can be a + + align:start position:0% + + + + align:start position:0% + +significant cooling + + align:start position:0% +significant cooling + + + align:start position:0% +significant cooling +term so for example the radiation May + + align:start position:0% +term so for example the radiation May + + + align:start position:0% +term so for example the radiation May +cool down our plasma you saw this + + align:start position:0% +cool down our plasma you saw this + + + align:start position:0% +cool down our plasma you saw this +particularly if you took Fusion Energy + + align:start position:0% +particularly if you took Fusion Energy + + + align:start position:0% +particularly if you took Fusion Energy +class and we remember that our brmr and + + align:start position:0% +class and we remember that our brmr and + + + align:start position:0% +class and we remember that our brmr and +cooling there was a significant loss + + align:start position:0% +cooling there was a significant loss + + + align:start position:0% +cooling there was a significant loss +mechanism in our zero power that balance + + align:start position:0% +mechanism in our zero power that balance + + + align:start position:0% +mechanism in our zero power that balance +but as well as being maybe pesky in the + + align:start position:0% +but as well as being maybe pesky in the + + + align:start position:0% +but as well as being maybe pesky in the +sense that they cool our nice hot plers + + align:start position:0% +sense that they cool our nice hot plers + + + align:start position:0% +sense that they cool our nice hot plers +down of course they also give us + + align:start position:0% +down of course they also give us + + + align:start position:0% +down of course they also give us +information so if we can study the + + align:start position:0% +information so if we can study the + + + align:start position:0% +information so if we can study the +Spectrum and the location and the + + align:start position:0% +Spectrum and the location and the + + + align:start position:0% +Spectrum and the location and the +temporal variation of this + + align:start position:0% +temporal variation of this + + + align:start position:0% +temporal variation of this +electromagnetic radiation we can get + + align:start position:0% +electromagnetic radiation we can get + + + align:start position:0% +electromagnetic radiation we can get +information on our plasma and this of + + align:start position:0% +information on our plasma and this of + + + align:start position:0% +information on our plasma and this of +course is our focus in this course + + align:start position:0% +course is our focus in this course + + + align:start position:0% +course is our focus in this course +because this is a diagnostic of course + + align:start position:0% +because this is a diagnostic of course + + + align:start position:0% +because this is a diagnostic of course +right so in this course we like + + align:start position:0% +right so in this course we like + + + align:start position:0% +right so in this course we like +radiation maybe in the previous course + + align:start position:0% +radiation maybe in the previous course + + + align:start position:0% +radiation maybe in the previous course +decided you didn't like radiation + + align:start position:0% +decided you didn't like radiation + + + align:start position:0% +decided you didn't like radiation +because he wants to do Fusion but here + + align:start position:0% +because he wants to do Fusion but here + + + align:start position:0% +because he wants to do Fusion but here +we like the + + align:start position:0% +we like the + + + align:start position:0% +we like the +radiation now in general the way that + + align:start position:0% +radiation now in general the way that + + + align:start position:0% +radiation now in general the way that +radiation moves around inside the plasma + + align:start position:0% +radiation moves around inside the plasma + + + align:start position:0% +radiation moves around inside the plasma +or indeed inside any fluid is not + + align:start position:0% +or indeed inside any fluid is not + + + align:start position:0% +or indeed inside any fluid is not +trivial right and we want to think about + + align:start position:0% +trivial right and we want to think about + + + align:start position:0% +trivial right and we want to think about +how that radiation is transported this + + align:start position:0% +how that radiation is transported this + + + align:start position:0% +how that radiation is transported this +is a whole Topic in itself that we'll + + align:start position:0% +is a whole Topic in itself that we'll + + + align:start position:0% +is a whole Topic in itself that we'll +only cover briefly here the topic of + + align:start position:0% +only cover briefly here the topic of + + + align:start position:0% +only cover briefly here the topic of +radiation + + align:start position:0% + + + + align:start position:0% + +transport the basic idea in r radiation + + align:start position:0% +transport the basic idea in r radiation + + + align:start position:0% +transport the basic idea in r radiation +transport is that you have some sort of + + align:start position:0% +transport is that you have some sort of + + + align:start position:0% +transport is that you have some sort of +plasma there'll be radiation emitted in + + align:start position:0% +plasma there'll be radiation emitted in + + + align:start position:0% +plasma there'll be radiation emitted in +one + + align:start position:0% + + + + align:start position:0% + +place and that will locally cool the + + align:start position:0% +place and that will locally cool the + + + align:start position:0% +place and that will locally cool the +plasma and that radiation may be em + + align:start position:0% +plasma and that radiation may be em + + + align:start position:0% +plasma and that radiation may be em +absorbed in another place which will + + align:start position:0% +absorbed in another place which will + + + align:start position:0% +absorbed in another place which will +locally heat the plasma but then that + + align:start position:0% +locally heat the plasma but then that + + + align:start position:0% +locally heat the plasma but then that +bit of plasma will also + + align:start position:0% +bit of plasma will also + + + align:start position:0% +bit of plasma will also +Reit and so the cycle continues and you + + align:start position:0% +Reit and so the cycle continues and you + + + align:start position:0% +Reit and so the cycle continues and you +can see straight away that in three + + align:start position:0% +can see straight away that in three + + + align:start position:0% +can see straight away that in three +dimensions in a in homog system this is + + align:start position:0% +dimensions in a in homog system this is + + + align:start position:0% +dimensions in a in homog system this is +going to be very very complicated but + + align:start position:0% +going to be very very complicated but + + + align:start position:0% +going to be very very complicated but +this effectively the transport of + + align:start position:0% + + + + align:start position:0% + +energy and this transport can be highly + + align:start position:0% +energy and this transport can be highly + + + align:start position:0% +energy and this transport can be highly +non-local so you may be used to thinking + + align:start position:0% +non-local so you may be used to thinking + + + align:start position:0% +non-local so you may be used to thinking +about heat transport in uh you know a + + align:start position:0% +about heat transport in uh you know a + + + align:start position:0% +about heat transport in uh you know a +system where we've got some sort of uh + + align:start position:0% +system where we've got some sort of uh + + + align:start position:0% +system where we've got some sort of uh +heat + + align:start position:0% +heat + + + align:start position:0% +heat +uh thermal conductivity uh and we look + + align:start position:0% +uh thermal conductivity uh and we look + + + align:start position:0% +uh thermal conductivity uh and we look +at the profusion of the Heat through the + + align:start position:0% +at the profusion of the Heat through the + + + align:start position:0% +at the profusion of the Heat through the +material that's a very local process the + + align:start position:0% +material that's a very local process the + + + align:start position:0% +material that's a very local process the +amount of heat that's traveling just + + align:start position:0% +amount of heat that's traveling just + + + align:start position:0% +amount of heat that's traveling just +depends on the local temperature + + align:start position:0% +depends on the local temperature + + + align:start position:0% +depends on the local temperature +gradients but here we could have a + + align:start position:0% +gradients but here we could have a + + + align:start position:0% +gradients but here we could have a +region which is emitting and it gets + + align:start position:0% +region which is emitting and it gets + + + align:start position:0% +region which is emitting and it gets +absorbed a very very long way away and + + align:start position:0% +absorbed a very very long way away and + + + align:start position:0% +absorbed a very very long way away and +because that radiation is traveling + + align:start position:0% +because that radiation is traveling + + + align:start position:0% +because that radiation is traveling +close to the speed of light this can be + + align:start position:0% +close to the speed of light this can be + + + align:start position:0% +close to the speed of light this can be +a very very fast process so this + + align:start position:0% +a very very fast process so this + + + align:start position:0% +a very very fast process so this +non-locality makes solving the full + + align:start position:0% +non-locality makes solving the full + + + align:start position:0% +non-locality makes solving the full +radiation transport problem extremely + + align:start position:0% +radiation transport problem extremely + + + align:start position:0% +radiation transport problem extremely +difficult um in reality if we want to + + align:start position:0% +difficult um in reality if we want to + + + align:start position:0% +difficult um in reality if we want to +solve radiation transport we often + + align:start position:0% +solve radiation transport we often + + + align:start position:0% +solve radiation transport we often +assume that this is a diffusive process + + align:start position:0% +assume that this is a diffusive process + + + align:start position:0% +assume that this is a diffusive process +and there are reasons why + + align:start position:0% +and there are reasons why + + + align:start position:0% +and there are reasons why +that assumption might be valid but there + + align:start position:0% +that assumption might be valid but there + + + align:start position:0% +that assumption might be valid but there +are also good reasons why it may not be + + align:start position:0% +are also good reasons why it may not be + + + align:start position:0% +are also good reasons why it may not be +valid in general so just the give you an + + align:start position:0% +valid in general so just the give you an + + + align:start position:0% +valid in general so just the give you an +overview that radiation transfer is + + align:start position:0% +overview that radiation transfer is + + + align:start position:0% +overview that radiation transfer is +complicated we're just be doing a + + align:start position:0% +complicated we're just be doing a + + + align:start position:0% +complicated we're just be doing a +simplified version of it here but + + align:start position:0% +simplified version of it here but + + + align:start position:0% +simplified version of it here but +radiation transport is extremely + + align:start position:0% +radiation transport is extremely + + + align:start position:0% +radiation transport is extremely +important for understanding uh how how + + align:start position:0% +important for understanding uh how how + + + align:start position:0% +important for understanding uh how how +plasmas work um for example the + + align:start position:0% +plasmas work um for example the + + + align:start position:0% +plasmas work um for example the +significant cooling but it's also very + + align:start position:0% +significant cooling but it's also very + + + align:start position:0% +significant cooling but it's also very +important for understanding how we get + + align:start position:0% +important for understanding how we get + + + align:start position:0% +important for understanding how we get +information from the plasmas because if + + align:start position:0% +information from the plasmas because if + + + align:start position:0% +information from the plasmas because if +you just have a camera sitting out + + align:start position:0% +you just have a camera sitting out + + + align:start position:0% +you just have a camera sitting out +here looking at the plasma and you just + + align:start position:0% +here looking at the plasma and you just + + + align:start position:0% +here looking at the plasma and you just +see some light coming out you really + + align:start position:0% +see some light coming out you really + + + align:start position:0% +see some light coming out you really +want to have some model that tells you + + align:start position:0% +want to have some model that tells you + + + align:start position:0% +want to have some model that tells you +where that light came from inside your + + align:start position:0% +where that light came from inside your + + + align:start position:0% +where that light came from inside your +plasma if you just think it's all coming + + align:start position:0% +plasma if you just think it's all coming + + + align:start position:0% +plasma if you just think it's all coming +from the surface you'll get one result + + align:start position:0% +from the surface you'll get one result + + + align:start position:0% +from the surface you'll get one result +if you think it's coming from Mod within + + align:start position:0% +if you think it's coming from Mod within + + + align:start position:0% +if you think it's coming from Mod within +the plasma you'll get a different result + + align:start position:0% +the plasma you'll get a different result + + + align:start position:0% +the plasma you'll get a different result +so it's very important to understand + + align:start position:0% +so it's very important to understand + + + align:start position:0% +so it's very important to understand +this radiation transport conure so we're + + align:start position:0% +this radiation transport conure so we're + + + align:start position:0% +this radiation transport conure so we're +going to start by having a look at + + align:start position:0% +going to start by having a look at + + + align:start position:0% +going to start by having a look at +radiation transport before we even start + + align:start position:0% +radiation transport before we even start + + + align:start position:0% +radiation transport before we even start +to talk about what the radiation is or + + align:start position:0% +to talk about what the radiation is or + + + align:start position:0% +to talk about what the radiation is or +how it's produced so even without + + align:start position:0% +how it's produced so even without + + + align:start position:0% +how it's produced so even without +knowing any of the details what's making + + align:start position:0% +knowing any of the details what's making + + + align:start position:0% +knowing any of the details what's making +all these radio waves and x-rays and gam + + align:start position:0% +all these radio waves and x-rays and gam + + + align:start position:0% +all these radio waves and x-rays and gam +rays and things like that we're going to + + align:start position:0% +rays and things like that we're going to + + + align:start position:0% +rays and things like that we're going to +look at a radiation transport framework + + align:start position:0% +look at a radiation transport framework + + + align:start position:0% +look at a radiation transport framework +which will then apply for all of the + + align:start position:0% +which will then apply for all of the + + + align:start position:0% +which will then apply for all of the +different wavelengths that we're + + align:start position:0% +different wavelengths that we're + + + align:start position:0% +different wavelengths that we're +working okay that's very high level any + + align:start position:0% +working okay that's very high level any + + + align:start position:0% +working okay that's very high level any +questions on that so + + align:start position:0% + + + + align:start position:0% + +far um Professor yes um when you say + + align:start position:0% +far um Professor yes um when you say + + + align:start position:0% +far um Professor yes um when you say +assume diffuse what what does that + + align:start position:0% +assume diffuse what what does that + + + align:start position:0% +assume diffuse what what does that +exactly mean sorry I was talking at the + + align:start position:0% +exactly mean sorry I was talking at the + + + align:start position:0% +exactly mean sorry I was talking at the +same time so the idea was that um most + + align:start position:0% +same time so the idea was that um most + + + align:start position:0% +same time so the idea was that um most +of the time when we're trying to solve + + align:start position:0% +of the time when we're trying to solve + + + align:start position:0% +of the time when we're trying to solve +radiation transport uh we can't uh use + + align:start position:0% +radiation transport uh we can't uh use + + + align:start position:0% +radiation transport uh we can't uh use +this non-local model because it's very + + align:start position:0% +this non-local model because it's very + + + align:start position:0% +this non-local model because it's very +very complicated uh and so we often make + + align:start position:0% +very complicated uh and so we often make + + + align:start position:0% +very complicated uh and so we often make +assumptions that our transport is + + align:start position:0% +assumptions that our transport is + + + align:start position:0% +assumptions that our transport is +diffusive I'm not really going into this + + align:start position:0% +diffusive I'm not really going into this + + + align:start position:0% +diffusive I'm not really going into this +in great deal of detail here but there + + align:start position:0% +in great deal of detail here but there + + + align:start position:0% +in great deal of detail here but there +are I can give some references later if + + align:start position:0% +are I can give some references later if + + + align:start position:0% +are I can give some references later if +you want for yeah great thank you the + + align:start position:0% +you want for yeah great thank you the + + + align:start position:0% +you want for yeah great thank you the +other thing I will say is that a lot of + + align:start position:0% +other thing I will say is that a lot of + + + align:start position:0% +other thing I will say is that a lot of +this radiation transport stuff as we'll + + align:start position:0% +this radiation transport stuff as we'll + + + align:start position:0% +this radiation transport stuff as we'll +find out uh is important when you have + + align:start position:0% +find out uh is important when you have + + + align:start position:0% +find out uh is important when you have +some sort of uh opacity in your system + + align:start position:0% +some sort of uh opacity in your system + + + align:start position:0% +some sort of uh opacity in your system +for sufficiently high energy x-rays in a + + align:start position:0% +for sufficiently high energy x-rays in a + + + align:start position:0% +for sufficiently high energy x-rays in a +sufficiently sparse plasma a toac then + + align:start position:0% +sufficiently sparse plasma a toac then + + + align:start position:0% +sufficiently sparse plasma a toac then +radiation transport is not necessarily + + align:start position:0% +radiation transport is not necessarily + + + align:start position:0% +radiation transport is not necessarily +very important and so you might think oh + + align:start position:0% +very important and so you might think oh + + + align:start position:0% +very important and so you might think oh +I'm a toac person I don't need to know + + align:start position:0% +I'm a toac person I don't need to know + + + align:start position:0% +I'm a toac person I don't need to know +this but we'll find out very very + + align:start position:0% +this but we'll find out very very + + + align:start position:0% +this but we'll find out very very +quickly that radiation transport is + + align:start position:0% +quickly that radiation transport is + + + align:start position:0% +quickly that radiation transport is +still incredibly important uh for the + + align:start position:0% +still incredibly important uh for the + + + align:start position:0% +still incredibly important uh for the +lower frequency waves like the electron + + align:start position:0% +lower frequency waves like the electron + + + align:start position:0% +lower frequency waves like the electron +cyron emission in a toomax so people + + align:start position:0% +cyron emission in a toomax so people + + + align:start position:0% +cyron emission in a toomax so people +still need to pay attention even if they + + align:start position:0% +still need to pay attention even if they + + + align:start position:0% +still need to pay attention even if they +think they're too good for radiation + + align:start position:0% +think they're too good for radiation + + + align:start position:0% +think they're too good for radiation +transport so let's have a look at what's + + align:start position:0% +transport so let's have a look at what's + + + align:start position:0% +transport so let's have a look at what's +going on + + align:start position:0% +going on + + + align:start position:0% +going on +here again we're going to have some sort + + align:start position:0% +here again we're going to have some sort + + + align:start position:0% +here again we're going to have some sort +of + + align:start position:0% + + + + align:start position:0% + +plasma + + align:start position:0% +plasma + + + align:start position:0% +plasma +and we're going to have some radiation + + align:start position:0% +and we're going to have some radiation + + + align:start position:0% +and we're going to have some radiation +coming into the plasma maybe this is + + align:start position:0% +coming into the plasma maybe this is + + + align:start position:0% +coming into the plasma maybe this is +radiation from another part of the + + align:start position:0% +radiation from another part of the + + + align:start position:0% +radiation from another part of the +plasma maybe we have generated a beam of + + align:start position:0% +plasma maybe we have generated a beam of + + + align:start position:0% +plasma maybe we have generated a beam of +x-rays or lasers or microwaves that + + align:start position:0% +x-rays or lasers or microwaves that + + + align:start position:0% +x-rays or lasers or microwaves that +we're using to shine through the plas + + align:start position:0% +we're using to shine through the plas + + + align:start position:0% +we're using to shine through the plas +doesn't really matter here this + + align:start position:0% +doesn't really matter here this + + + align:start position:0% +doesn't really matter here this +radiation is going to have an intensity + + align:start position:0% +radiation is going to have an intensity + + + align:start position:0% +radiation is going to have an intensity +I and we're going to + + align:start position:0% +I and we're going to + + + align:start position:0% +I and we're going to +parameterize the path of the radiation + + align:start position:0% +parameterize the path of the radiation + + + align:start position:0% +parameterize the path of the radiation +with this parameter s so we're going to + + align:start position:0% +with this parameter s so we're going to + + + align:start position:0% +with this parameter s so we're going to +call the point where the radiation + + align:start position:0% +call the point where the radiation + + + align:start position:0% +call the point where the radiation +enters the plasma + + align:start position:0% +enters the plasma + + + align:start position:0% +enters the plasma +S1 and then there is some path s through + + align:start position:0% +S1 and then there is some path s through + + + align:start position:0% +S1 and then there is some path s through +the + + align:start position:0% +the + + + align:start position:0% +the +plasma and we're interested in the + + align:start position:0% +plasma and we're interested in the + + + align:start position:0% +plasma and we're interested in the +properties of the radiation at Point S2 + + align:start position:0% +properties of the radiation at Point S2 + + + align:start position:0% +properties of the radiation at Point S2 +that's I at + + align:start position:0% +that's I at + + + align:start position:0% +that's I at +S2 when the radiation has exited the + + align:start position:0% +S2 when the radiation has exited the + + + align:start position:0% +S2 when the radiation has exited the +plasma here so what we want to know is + + align:start position:0% +plasma here so what we want to know is + + + align:start position:0% +plasma here so what we want to know is +how does I change along this path s now + + align:start position:0% +how does I change along this path s now + + + align:start position:0% +how does I change along this path s now +in general this path s could be curved + + align:start position:0% +in general this path s could be curved + + + align:start position:0% +in general this path s could be curved +because we've talked extensively about + + align:start position:0% +because we've talked extensively about + + + align:start position:0% +because we've talked extensively about +the fact that when you have changes in + + align:start position:0% +the fact that when you have changes in + + + align:start position:0% +the fact that when you have changes in +the refractive index you're going to + + align:start position:0% +the refractive index you're going to + + + align:start position:0% +the refractive index you're going to +have refraction of your red now although + + align:start position:0% +have refraction of your red now although + + + align:start position:0% +have refraction of your red now although +I have drawn it curved here a lot of the + + align:start position:0% +I have drawn it curved here a lot of the + + + align:start position:0% +I have drawn it curved here a lot of the +time I'm going to assume it's a straight + + align:start position:0% + + + + align:start position:0% + +line um so just watch out to that but if + + align:start position:0% +line um so just watch out to that but if + + + align:start position:0% +line um so just watch out to that but if +you want to solve the full thing you + + align:start position:0% +you want to solve the full thing you + + + align:start position:0% +you want to solve the full thing you +need to take this curvature into account + + align:start position:0% +need to take this curvature into account + + + align:start position:0% +need to take this curvature into account +okay and this quantity I that we're + + align:start position:0% +okay and this quantity I that we're + + + align:start position:0% +okay and this quantity I that we're +dealing with here this is a quantity + + align:start position:0% +dealing with here this is a quantity + + + align:start position:0% +dealing with here this is a quantity +which we can formly Define as the + + align:start position:0% +which we can formly Define as the + + + align:start position:0% +which we can formly Define as the +spectral + + align:start position:0% + + + + align:start position:0% + +Radiance I've used the symbol I which is + + align:start position:0% +Radiance I've used the symbol I which is + + + align:start position:0% +Radiance I've used the symbol I which is +often used for intensity because this is + + align:start position:0% +often used for intensity because this is + + + align:start position:0% +often used for intensity because this is +the symbol that's commonly used + + align:start position:0% +the symbol that's commonly used + + + align:start position:0% +the symbol that's commonly used +but we although people often refer to + + align:start position:0% +but we although people often refer to + + + align:start position:0% +but we although people often refer to +the spectral Radiance as the intensity + + align:start position:0% +the spectral Radiance as the intensity + + + align:start position:0% +the spectral Radiance as the intensity +they also use the word intensity to mean + + align:start position:0% +they also use the word intensity to mean + + + align:start position:0% +they also use the word intensity to mean +lots of different things and so if you + + align:start position:0% +lots of different things and so if you + + + align:start position:0% +lots of different things and so if you +go on Wikipedia on the radiosy Wikipedia + + align:start position:0% +go on Wikipedia on the radiosy Wikipedia + + + align:start position:0% +go on Wikipedia on the radiosy Wikipedia +page there's an incredible table that + + align:start position:0% +page there's an incredible table that + + + align:start position:0% +page there's an incredible table that +has very very Niche words for all + + align:start position:0% +has very very Niche words for all + + + align:start position:0% +has very very Niche words for all +thoughts of different quantities and + + align:start position:0% +thoughts of different quantities and + + + align:start position:0% +thoughts of different quantities and +this is the one that the table I always + + align:start position:0% +this is the one that the table I always + + + align:start position:0% +this is the one that the table I always +go to when I want to work out exactly + + align:start position:0% +go to when I want to work out exactly + + + align:start position:0% +go to when I want to work out exactly +what I'm talking about and the reason is + + align:start position:0% +what I'm talking about and the reason is + + + align:start position:0% +what I'm talking about and the reason is +that this word spectral Radiance here + + align:start position:0% +that this word spectral Radiance here + + + align:start position:0% +that this word spectral Radiance here +corresponds to one exact set of units + + align:start position:0% +corresponds to one exact set of units + + + align:start position:0% +corresponds to one exact set of units +which is the Watts the Jews per unit + + align:start position:0% +which is the Watts the Jews per unit + + + align:start position:0% +which is the Watts the Jews per unit +time being admitted being emitted + + align:start position:0% +time being admitted being emitted + + + align:start position:0% +time being admitted being emitted +through a area meter squared here + + align:start position:0% +through a area meter squared here + + + align:start position:0% +through a area meter squared here +through a solid + + align:start position:0% +through a solid + + + align:start position:0% +through a solid +angle per unit um + + align:start position:0% +angle per unit um + + + align:start position:0% +angle per unit um +per some spectral unit here so the + + align:start position:0% +per some spectral unit here so the + + + align:start position:0% +per some spectral unit here so the +spectral units could be something + + align:start position:0% + + + + align:start position:0% + +like + + align:start position:0% +like + + + align:start position:0% +like +HS it could be something like fules + + align:start position:0% +HS it could be something like fules + + + align:start position:0% +HS it could be something like fules +could be electron volts it could be + + align:start position:0% +could be electron volts it could be + + + align:start position:0% +could be electron volts it could be +meters the difference in this being + + align:start position:0% +meters the difference in this being + + + align:start position:0% +meters the difference in this being +depends how you're resolving your + + align:start position:0% +depends how you're resolving your + + + align:start position:0% +depends how you're resolving your +radiation spectrally so in terms of Herz + + align:start position:0% +radiation spectrally so in terms of Herz + + + align:start position:0% +radiation spectrally so in terms of Herz +that's where we're using like angular + + align:start position:0% +that's where we're using like angular + + + align:start position:0% +that's where we're using like angular +frequency and EV that's where we're + + align:start position:0% +frequency and EV that's where we're + + + align:start position:0% +frequency and EV that's where we're +using energy and meters that's where + + align:start position:0% +using energy and meters that's where + + + align:start position:0% +using energy and meters that's where +we're measuring it in weight so if we're + + align:start position:0% +we're measuring it in weight so if we're + + + align:start position:0% +we're measuring it in weight so if we're +talking about the spectral Radiance in + + align:start position:0% +talking about the spectral Radiance in + + + align:start position:0% +talking about the spectral Radiance in +terms of per I don't know gigahertz or + + align:start position:0% +terms of per I don't know gigahertz or + + + align:start position:0% +terms of per I don't know gigahertz or +per EV or per meters here of course if + + align:start position:0% +per EV or per meters here of course if + + + align:start position:0% +per EV or per meters here of course if +you put meters in this one then it + + align:start position:0% +you put meters in this one then it + + + align:start position:0% +you put meters in this one then it +starts to get complicated because this + + align:start position:0% +starts to get complicated because this + + + align:start position:0% +starts to get complicated because this +becomes a cubed and stuff like that and + + align:start position:0% +becomes a cubed and stuff like that and + + + align:start position:0% +becomes a cubed and stuff like that and +so people will actually write this as + + align:start position:0% +so people will actually write this as + + + align:start position:0% +so people will actually write this as +like watts per met squ per radian per + + align:start position:0% +like watts per met squ per radian per + + + align:start position:0% +like watts per met squ per radian per +meter just to remind themselves that + + align:start position:0% +meter just to remind themselves that + + + align:start position:0% +meter just to remind themselves that +they have an accident prob this it so + + align:start position:0% +they have an accident prob this it so + + + align:start position:0% +they have an accident prob this it so +what this means is that there is + + align:start position:0% +what this means is that there is + + + align:start position:0% +what this means is that there is +some amount of radiation that's going + + align:start position:0% +some amount of radiation that's going + + + align:start position:0% +some amount of radiation that's going +through uh some unit area that's meter + + align:start position:0% +through uh some unit area that's meter + + + align:start position:0% +through uh some unit area that's meter +squar and we've got whats going in this + + align:start position:0% +squar and we've got whats going in this + + + align:start position:0% +squar and we've got whats going in this +direction and that watts is subtended by + + align:start position:0% +direction and that watts is subtended by + + + align:start position:0% +direction and that watts is subtended by +some solid angle that's measured in + + align:start position:0% +some solid angle that's measured in + + + align:start position:0% +some solid angle that's measured in +stair Radiance and we're also resolving + + align:start position:0% +stair Radiance and we're also resolving + + + align:start position:0% +stair Radiance and we're also resolving +it in terms of like electron volts you + + align:start position:0% +it in terms of like electron volts you + + + align:start position:0% +it in terms of like electron volts you +this is a complicated + + align:start position:0% +this is a complicated + + + align:start position:0% +this is a complicated +quantity but it will correspond to your + + align:start position:0% +quantity but it will correspond to your + + + align:start position:0% +quantity but it will correspond to your +intuition of what intensity of light is + + align:start position:0% +intuition of what intensity of light is + + + align:start position:0% +intuition of what intensity of light is +like if you think about it for a little + + align:start position:0% +like if you think about it for a little + + + align:start position:0% +like if you think about it for a little +bit + + align:start position:0% +bit + + + align:start position:0% +bit +okay so let's just have an example here + + align:start position:0% +okay so let's just have an example here + + + align:start position:0% +okay so let's just have an example here +maybe our spectral Radiance and I may + + align:start position:0% +maybe our spectral Radiance and I may + + + align:start position:0% +maybe our spectral Radiance and I may +start calling this intensity every now + + align:start position:0% +start calling this intensity every now + + + align:start position:0% +start calling this intensity every now +and again initially has a + + align:start position:0% + + + + align:start position:0% + +spectrum and I do this in hertz + + align:start position:0% +spectrum and I do this in hertz + + + align:start position:0% +spectrum and I do this in hertz +here because this is what pson uses in + + align:start position:0% +here because this is what pson uses in + + + align:start position:0% +here because this is what pson uses in +his book maybe our Spectrum initially + + align:start position:0% +his book maybe our Spectrum initially + + + align:start position:0% +his book maybe our Spectrum initially +you know has some sort of complicated + + align:start position:0% +you know has some sort of complicated + + + align:start position:0% +you know has some sort of complicated +set of features spectral lines in the + + align:start position:0% +set of features spectral lines in the + + + align:start position:0% +set of features spectral lines in the +background stuff like that like this and + + align:start position:0% +background stuff like that like this and + + + align:start position:0% +background stuff like that like this and +by the time that it has traveled through + + align:start position:0% +by the time that it has traveled through + + + align:start position:0% +by the time that it has traveled through +the plasma there will be some emission + + align:start position:0% +the plasma there will be some emission + + + align:start position:0% +the plasma there will be some emission +inside the plasma the plasma will make + + align:start position:0% +inside the plasma the plasma will make + + + align:start position:0% +inside the plasma the plasma will make +more light which adds to our beam of + + align:start position:0% +more light which adds to our beam of + + + align:start position:0% +more light which adds to our beam of +light and there'll be some absorption + + align:start position:0% +light and there'll be some absorption + + + align:start position:0% +light and there'll be some absorption +inside the plasma gets rid of these so + + align:start position:0% +inside the plasma gets rid of these so + + + align:start position:0% +inside the plasma gets rid of these so +for example we might have absorption at + + align:start position:0% +for example we might have absorption at + + + align:start position:0% +for example we might have absorption at +these low frequencies they've been + + align:start position:0% +these low frequencies they've been + + + align:start position:0% +these low frequencies they've been +completely wiped out and then we will + + align:start position:0% +completely wiped out and then we will + + + align:start position:0% +completely wiped out and then we will +have some additional + + align:start position:0% +have some additional + + + align:start position:0% +have some additional +emission from inside the so here we + + align:start position:0% +emission from inside the so here we + + + align:start position:0% +emission from inside the so here we +would have a region where there was + + align:start position:0% + + + + align:start position:0% + +absorption and here we have a region + + align:start position:0% +absorption and here we have a region + + + align:start position:0% +absorption and here we have a region +where there was a + + align:start position:0% + + + + align:start position:0% + +mission so in general we want to come up + + align:start position:0% +mission so in general we want to come up + + + align:start position:0% +mission so in general we want to come up +with some formulas that will tell us how + + align:start position:0% +with some formulas that will tell us how + + + align:start position:0% +with some formulas that will tell us how +for a given amount absorption a given + + align:start position:0% +for a given amount absorption a given + + + align:start position:0% +for a given amount absorption a given +amount of emission in different parts of + + align:start position:0% +amount of emission in different parts of + + + align:start position:0% +amount of emission in different parts of +the plasma how the Spectra will change + + align:start position:0% +the plasma how the Spectra will change + + + align:start position:0% +the plasma how the Spectra will change +from one point to the other and this is + + align:start position:0% +from one point to the other and this is + + + align:start position:0% +from one point to the other and this is +the radiation transport equation which + + align:start position:0% +the radiation transport equation which + + + align:start position:0% +the radiation transport equation which +is the very fundamental equation in this + + align:start position:0% +is the very fundamental equation in this + + + align:start position:0% +is the very fundamental equation in this +field the radiation transport equation + + align:start position:0% +field the radiation transport equation + + + align:start position:0% +field the radiation transport equation +says that the + + align:start position:0% +says that the + + + align:start position:0% +says that the +change in spectral + + align:start position:0% +change in spectral + + + align:start position:0% +change in spectral +Radiance along our path that we + + align:start position:0% +Radiance along our path that we + + + align:start position:0% +Radiance along our path that we +parameterized by S is simply equal + + align:start position:0% +parameterized by S is simply equal + + + align:start position:0% +parameterized by S is simply equal +to this quantity + + align:start position:0% +to this quantity + + + align:start position:0% +to this quantity +J which is the + + align:start position:0% + + + + align:start position:0% + +emissivity + + align:start position:0% + + + + align:start position:0% + +minus the intensity or the spectral + + align:start position:0% +minus the intensity or the spectral + + + align:start position:0% +minus the intensity or the spectral +radius times by another quantity Alpha + + align:start position:0% +radius times by another quantity Alpha + + + align:start position:0% +radius times by another quantity Alpha +which is the opacity + + align:start position:0% + + + + align:start position:0% + +the important thing about the equation + + align:start position:0% +the important thing about the equation + + + align:start position:0% +the important thing about the equation +as we've written it here is that each of + + align:start position:0% +as we've written it here is that each of + + + align:start position:0% +as we've written it here is that each of +these quantities are functions of + + align:start position:0% + + + + align:start position:0% + +frequency and effectively this equation + + align:start position:0% +frequency and effectively this equation + + + align:start position:0% +frequency and effectively this equation +is linear in a frequency in the sense + + align:start position:0% +is linear in a frequency in the sense + + + align:start position:0% +is linear in a frequency in the sense +that we can solve the equations + + align:start position:0% +that we can solve the equations + + + align:start position:0% +that we can solve the equations +separately to each + + align:start position:0% + + + + align:start position:0% + +frequency so whatever is happening down + + align:start position:0% +frequency so whatever is happening down + + + align:start position:0% +frequency so whatever is happening down +the gahz range has nothing to do what's + + align:start position:0% +the gahz range has nothing to do what's + + + align:start position:0% +the gahz range has nothing to do what's +happening up in the X-ray + + align:start position:0% +happening up in the X-ray + + + align:start position:0% +happening up in the X-ray +range this is not necessarily true in + + align:start position:0% +range this is not necessarily true in + + + align:start position:0% +range this is not necessarily true in +order to make this assumption we have to + + align:start position:0% +order to make this assumption we have to + + + align:start position:0% +order to make this assumption we have to +neglect interesting processes like uh + + align:start position:0% +neglect interesting processes like uh + + + align:start position:0% +neglect interesting processes like uh +fluoresence where we might excite paral + + align:start position:0% +fluoresence where we might excite paral + + + align:start position:0% +fluoresence where we might excite paral +plasma of one frequency and get back + + align:start position:0% +plasma of one frequency and get back + + + align:start position:0% +plasma of one frequency and get back +lines of different frequencies but in + + align:start position:0% +lines of different frequencies but in + + + align:start position:0% +lines of different frequencies but in +order to be able to solve this equation + + align:start position:0% +order to be able to solve this equation + + + align:start position:0% +order to be able to solve this equation +easily we're going to neglect that so + + align:start position:0% +easily we're going to neglect that so + + + align:start position:0% +easily we're going to neglect that so +this is an assumption that we've made + + align:start position:0% +this is an assumption that we've made + + + align:start position:0% +this is an assumption that we've made +and I'll just tell you what the units of + + align:start position:0% +and I'll just tell you what the units of + + + align:start position:0% +and I'll just tell you what the units of +all these things are you can work them + + align:start position:0% +all these things are you can work them + + + align:start position:0% +all these things are you can work them +out yourself but the units of opacity + + align:start position:0% +out yourself but the units of opacity + + + align:start position:0% +out yourself but the units of opacity +very + + align:start position:0% +very + + + align:start position:0% +very +clearly it has units of inverse length + + align:start position:0% +clearly it has units of inverse length + + + align:start position:0% +clearly it has units of inverse length +scale and the units of emissivity are + + align:start position:0% +scale and the units of emissivity are + + + align:start position:0% +scale and the units of emissivity are +still watts per scar radian per + + align:start position:0% +still watts per scar radian per + + + align:start position:0% +still watts per scar radian per +Hertz but now it's not per meter squar + + align:start position:0% +Hertz but now it's not per meter squar + + + align:start position:0% +Hertz but now it's not per meter squar +but per + + align:start position:0% +but per + + + align:start position:0% +but per +meter + + align:start position:0% +meter + + + align:start position:0% +meter +cub and this reflects the fact that the + + align:start position:0% +cub and this reflects the fact that the + + + align:start position:0% +cub and this reflects the fact that the +emissivity is a measure of the + + align:start position:0% +emissivity is a measure of the + + + align:start position:0% +emissivity is a measure of the +light coming out from a small volume in + + align:start position:0% +light coming out from a small volume in + + + align:start position:0% +light coming out from a small volume in +every + + align:start position:0% +every + + + align:start position:0% +every +direction like this the per staran means + + align:start position:0% +direction like this the per staran means + + + align:start position:0% +direction like this the per staran means +that if you integrate over four Pi + + align:start position:0% +that if you integrate over four Pi + + + align:start position:0% +that if you integrate over four Pi +stents you get the total radiated power + + align:start position:0% +stents you get the total radiated power + + + align:start position:0% +stents you get the total radiated power +per cubic + + align:start position:0% + + + + align:start position:0% + +meter our MS and opacity are also + + align:start position:0% +meter our MS and opacity are also + + + align:start position:0% +meter our MS and opacity are also +functions of s right yes I've I've + + align:start position:0% +functions of s right yes I've I've + + + align:start position:0% +functions of s right yes I've I've +suppressed the s in here but you're + + align:start position:0% +suppressed the s in here but you're + + + align:start position:0% +suppressed the s in here but you're +quite right like as we go through the + + align:start position:0% +quite right like as we go through the + + + align:start position:0% +quite right like as we go through the +plasma these will in general change + + align:start position:0% +plasma these will in general change + + + align:start position:0% +plasma these will in general change +yeah these are properties of the + + align:start position:0% +yeah these are properties of the + + + align:start position:0% +yeah these are properties of the +material could be a plasma it could be a + + align:start position:0% +material could be a plasma it could be a + + + align:start position:0% +material could be a plasma it could be a +lump of Cloudy glass we haven't actually + + align:start position:0% +lump of Cloudy glass we haven't actually + + + align:start position:0% +lump of Cloudy glass we haven't actually +decided or said anything about them and + + align:start position:0% +decided or said anything about them and + + + align:start position:0% +decided or said anything about them and +we won't learn how to calculate these + + align:start position:0% +we won't learn how to calculate these + + + align:start position:0% +we won't learn how to calculate these +for some time you just have to take my + + align:start position:0% +for some time you just have to take my + + + align:start position:0% +for some time you just have to take my +word for it that you can calculate the + + align:start position:0% +word for it that you can calculate the + + + align:start position:0% +word for it that you can calculate the +Amity and the opacity you've come across + + align:start position:0% +Amity and the opacity you've come across + + + align:start position:0% +Amity and the opacity you've come across +some of this stuff before if you've done + + align:start position:0% +some of this stuff before if you've done + + + align:start position:0% +some of this stuff before if you've done +like black body radiation so um but + + align:start position:0% +like black body radiation so um but + + + align:start position:0% +like black body radiation so um but +we're just going to leave it like that + + align:start position:0% +we're just going to leave it like that + + + align:start position:0% +we're just going to leave it like that +at the moment + + align:start position:0% +at the moment + + + align:start position:0% +at the moment +okay any questions yes SE does this + + align:start position:0% +okay any questions yes SE does this + + + align:start position:0% +okay any questions yes SE does this +equation if you include temperature + + align:start position:0% +equation if you include temperature + + + align:start position:0% +equation if you include temperature +dependence of the inity andity in this + + align:start position:0% +dependence of the inity andity in this + + + align:start position:0% +dependence of the inity andity in this +equation be used to understand eating of + + align:start position:0% +equation be used to understand eating of + + + align:start position:0% +equation be used to understand eating of +plasma if you're thinking about maybe + + align:start position:0% +plasma if you're thinking about maybe + + + align:start position:0% +plasma if you're thinking about maybe +you're injecting waves or something so + + align:start position:0% +you're injecting waves or something so + + + align:start position:0% +you're injecting waves or something so +the question was can this equation be + + align:start position:0% +the question was can this equation be + + + align:start position:0% +the question was can this equation be +used to understand heating of the + + align:start position:0% +used to understand heating of the + + + align:start position:0% +used to understand heating of the +plasma um yeah effectively this term is + + align:start position:0% +plasma um yeah effectively this term is + + + align:start position:0% +plasma um yeah effectively this term is +the amount of energy lost from the + + align:start position:0% +the amount of energy lost from the + + + align:start position:0% +the amount of energy lost from the +beam uh per unit length and so you could + + align:start position:0% +beam uh per unit length and so you could + + + align:start position:0% +beam uh per unit length and so you could +add that energy into your plasma so you + + align:start position:0% +add that energy into your plasma so you + + + align:start position:0% +add that energy into your plasma so you +could couple this to an energy equation + + align:start position:0% +could couple this to an energy equation + + + align:start position:0% +could couple this to an energy equation +in your plasma but this itself is not an + + align:start position:0% +in your plasma but this itself is not an + + + align:start position:0% +in your plasma but this itself is not an +energy equation for the plasma this is + + align:start position:0% +energy equation for the plasma this is + + + align:start position:0% +energy equation for the plasma this is +an energy equation effectively for the + + align:start position:0% +an energy equation effectively for the + + + align:start position:0% +an energy equation effectively for the +energy in the radiation I see okay yeah + + align:start position:0% +energy in the radiation I see okay yeah + + + align:start position:0% +energy in the radiation I see okay yeah +yeah but if you wanted to do full + + align:start position:0% +yeah but if you wanted to do full + + + align:start position:0% +yeah but if you wanted to do full +radiation transport you would couple + + align:start position:0% +radiation transport you would couple + + + align:start position:0% +radiation transport you would couple +this to your energy equation yeah other + + align:start position:0% + + + + align:start position:0% + +questions okay it's very convenient to + + align:start position:0% +questions okay it's very convenient to + + + align:start position:0% +questions okay it's very convenient to +introduce a slightly mysterious but + + align:start position:0% +introduce a slightly mysterious but + + + align:start position:0% +introduce a slightly mysterious but +important quantity called the optical + + align:start position:0% + + + + align:start position:0% + +depth and the optical depth which is + + align:start position:0% +depth and the optical depth which is + + + align:start position:0% +depth and the optical depth which is +still a function of frequency and I'm + + align:start position:0% +still a function of frequency and I'm + + + align:start position:0% +still a function of frequency and I'm +just going to keep trying to write these + + align:start position:0% +just going to keep trying to write these + + + align:start position:0% +just going to keep trying to write these +as long as possible to remind you + + align:start position:0% +as long as possible to remind you + + + align:start position:0% +as long as possible to remind you +functions of frequency this is the + + align:start position:0% +functions of frequency this is the + + + align:start position:0% +functions of frequency this is the +quantity which is defined + + align:start position:0% +quantity which is defined + + + align:start position:0% +quantity which is defined +as the integral of the + + align:start position:0% +as the integral of the + + + align:start position:0% +as the integral of the +opacity along some section of path and + + align:start position:0% +opacity along some section of path and + + + align:start position:0% +opacity along some section of path and +just written like this this is an + + align:start position:0% +just written like this this is an + + + align:start position:0% +just written like this this is an +indefinite integral we will come up with + + align:start position:0% +indefinite integral we will come up with + + + align:start position:0% +indefinite integral we will come up with +some limits to it later on so at the + + align:start position:0% +some limits to it later on so at the + + + align:start position:0% +some limits to it later on so at the +moment it doesn't have a huge meaning + + align:start position:0% +moment it doesn't have a huge meaning + + + align:start position:0% +moment it doesn't have a huge meaning +but the important thing about it is that + + align:start position:0% +but the important thing about it is that + + + align:start position:0% +but the important thing about it is that +it depends + + align:start position:0% +it depends + + + align:start position:0% +it depends +on the actual path s + + align:start position:0% +on the actual path s + + + align:start position:0% +on the actual path s +and frequency so the optical depth can + + align:start position:0% +and frequency so the optical depth can + + + align:start position:0% +and frequency so the optical depth can +be very different than + + align:start position:0% +be very different than + + + align:start position:0% +be very different than +x-rays than for microwaves so again very + + align:start position:0% +x-rays than for microwaves so again very + + + align:start position:0% +x-rays than for microwaves so again very +important to realize that the reason we + + align:start position:0% +important to realize that the reason we + + + align:start position:0% +important to realize that the reason we +introduced this is that if you stare at + + align:start position:0% +introduced this is that if you stare at + + + align:start position:0% +introduced this is that if you stare at +this definition and this equation you + + align:start position:0% +this definition and this equation you + + + align:start position:0% +this definition and this equation you +might be able to convince yourselves + + align:start position:0% +might be able to convince yourselves + + + align:start position:0% +might be able to convince yourselves +that we can then rewrite the equation as + + align:start position:0% +that we can then rewrite the equation as + + + align:start position:0% +that we can then rewrite the equation as +d + + align:start position:0% +d + + + align:start position:0% +d +i is equal to J upon + + align:start position:0% +i is equal to J upon + + + align:start position:0% +i is equal to J upon +Alpha minus I and this is rather a nice + + align:start position:0% +Alpha minus I and this is rather a nice + + + align:start position:0% +Alpha minus I and this is rather a nice +equation because we're used to equations + + align:start position:0% +equation because we're used to equations + + + align:start position:0% +equation because we're used to equations +in form D to equals minus I these are + + align:start position:0% +in form D to equals minus I these are + + + align:start position:0% +in form D to equals minus I these are +sort of exponential growth exponential + + align:start position:0% +sort of exponential growth exponential + + + align:start position:0% +sort of exponential growth exponential +decay equations and we're also used to + + align:start position:0% +decay equations and we're also used to + + + align:start position:0% +decay equations and we're also used to +adding an extra term in here which is + + align:start position:0% +adding an extra term in here which is + + + align:start position:0% +adding an extra term in here which is +like a Source ter so what this equation + + align:start position:0% +like a Source ter so what this equation + + + align:start position:0% +like a Source ter so what this equation +says is that the intensity is going to + + align:start position:0% +says is that the intensity is going to + + + align:start position:0% +says is that the intensity is going to +drop off along the path parameterized by + + align:start position:0% +drop off along the path parameterized by + + + align:start position:0% +drop off along the path parameterized by +S which is now sitting inside C but the + + align:start position:0% +S which is now sitting inside C but the + + + align:start position:0% +S which is now sitting inside C but the +intensity is going to increase with a + + align:start position:0% +intensity is going to increase with a + + + align:start position:0% +intensity is going to increase with a +parameter that looks like J upon Alpha + + align:start position:0% +parameter that looks like J upon Alpha + + + align:start position:0% +parameter that looks like J upon Alpha +and I'll show you how we're going to use + + align:start position:0% +and I'll show you how we're going to use + + + align:start position:0% +and I'll show you how we're going to use +that in a + + align:start position:0% + + + + align:start position:0% + +second just label explicitly this this + + align:start position:0% +second just label explicitly this this + + + align:start position:0% +second just label explicitly this this +looks like a + + align:start position:0% + + + + align:start position:0% + +function so now we can go back to this + + align:start position:0% +function so now we can go back to this + + + align:start position:0% +function so now we can go back to this +problem and we can solve this equation + + align:start position:0% +problem and we can solve this equation + + + align:start position:0% +problem and we can solve this equation +so we can + + align:start position:0% + + + + align:start position:0% + +solve + + align:start position:0% +solve + + + align:start position:0% +solve +for S1 + + align:start position:0% +for S1 + + + align:start position:0% +for S1 +to S2 like that and we're going to solve + + align:start position:0% +to S2 like that and we're going to solve + + + align:start position:0% +to S2 like that and we're going to solve +it by integrating up with with respect + + align:start position:0% +it by integrating up with with respect + + + align:start position:0% +it by integrating up with with respect +to tow here and we're going to find that + + align:start position:0% +to tow here and we're going to find that + + + align:start position:0% +to tow here and we're going to find that +the + + align:start position:0% + + + + align:start position:0% + +intensity at S2 on the other side of the + + align:start position:0% +intensity at S2 on the other side of the + + + align:start position:0% +intensity at S2 on the other side of the +plasma is going to be the intensity that + + align:start position:0% +plasma is going to be the intensity that + + + align:start position:0% +plasma is going to be the intensity that +we started out with at S1 Times by a + + align:start position:0% +we started out with at S1 Times by a + + + align:start position:0% +we started out with at S1 Times by a +factor of to one minus to 2 so this is + + align:start position:0% +factor of to one minus to 2 so this is + + + align:start position:0% +factor of to one minus to 2 so this is +an attenuation that takes into account + + align:start position:0% +an attenuation that takes into account + + + align:start position:0% +an attenuation that takes into account +any absorption along the path and then + + align:start position:0% +any absorption along the path and then + + + align:start position:0% +any absorption along the path and then +along with the initial radiation we + + align:start position:0% +along with the initial radiation we + + + align:start position:0% +along with the initial radiation we +started with we're going to have a + + align:start position:0% +started with we're going to have a + + + align:start position:0% +started with we're going to have a +second term which corresponds to the + + align:start position:0% +second term which corresponds to the + + + align:start position:0% +second term which corresponds to the +radiation we've picked up through the + + align:start position:0% +radiation we've picked up through the + + + align:start position:0% +radiation we've picked up through the +plasma du to the enity and that's going + + align:start position:0% +plasma du to the enity and that's going + + + align:start position:0% +plasma du to the enity and that's going +to be the integral from S1 to + + align:start position:0% + + + + align:start position:0% + +S2 our emissivity now explicitly + + align:start position:0% +S2 our emissivity now explicitly + + + align:start position:0% +S2 our emissivity now explicitly +parameterized as a function of s as + + align:start position:0% +parameterized as a function of s as + + + align:start position:0% +parameterized as a function of s as +someone asked already all of the JS and + + align:start position:0% +someone asked already all of the JS and + + + align:start position:0% +someone asked already all of the JS and +alas our functions of s but now I'm + + align:start position:0% +alas our functions of s but now I'm + + + align:start position:0% +alas our functions of s but now I'm +making explicit + + align:start position:0% +making explicit + + + align:start position:0% +making explicit +here e to the minus + + align:start position:0% +here e to the minus + + + align:start position:0% +here e to the minus +L2 DS what + + align:start position:0% +L2 DS what + + + align:start position:0% +L2 DS what +this exponential here is doing is saying + + align:start position:0% +this exponential here is doing is saying + + + align:start position:0% +this exponential here is doing is saying +yeah okay you're adding radiation but + + align:start position:0% +yeah okay you're adding radiation but + + + align:start position:0% +yeah okay you're adding radiation but +that radiation may also be absorbed if + + align:start position:0% +that radiation may also be absorbed if + + + align:start position:0% +that radiation may also be absorbed if +that radiation is emitted very early on + + align:start position:0% +that radiation is emitted very early on + + + align:start position:0% +that radiation is emitted very early on +near S1 it's going to be absorbed a lot + + align:start position:0% +near S1 it's going to be absorbed a lot + + + align:start position:0% +near S1 it's going to be absorbed a lot +as it goes through the plasma if the + + align:start position:0% +as it goes through the plasma if the + + + align:start position:0% +as it goes through the plasma if the +radiation is emitted late along the path + + align:start position:0% +radiation is emitted late along the path + + + align:start position:0% +radiation is emitted late along the path +close to S2 it's not going to be + + align:start position:0% +close to S2 it's not going to be + + + align:start position:0% +close to S2 it's not going to be +absorbed very much so it matters where + + align:start position:0% +absorbed very much so it matters where + + + align:start position:0% +absorbed very much so it matters where +along the path the radiation is actually + + align:start position:0% +along the path the radiation is actually + + + align:start position:0% +along the path the radiation is actually +emitted so let me just label these terms + + align:start position:0% +emitted so let me just label these terms + + + align:start position:0% +emitted so let me just label these terms +here so this is + + align:start position:0% +here so this is + + + align:start position:0% +here so this is +the + + align:start position:0% + + + + align:start position:0% + +original uh I'm going to call it + + align:start position:0% +original uh I'm going to call it + + + align:start position:0% +original uh I'm going to call it +spectral Radiance right so I don't + + align:start position:0% +spectral Radiance right so I don't + + + align:start position:0% +spectral Radiance right so I don't +accidentally say intensity so the + + align:start position:0% +accidentally say intensity so the + + + align:start position:0% +accidentally say intensity so the +original spectral + + align:start position:0% +original spectral + + + align:start position:0% +original spectral +Radiance this is the optical + + align:start position:0% + + + + align:start position:0% + +depth from S1 to + + align:start position:0% +depth from S1 to + + + align:start position:0% +depth from S1 to +S2 this is + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% + + + + align:start position:0% + +emission along the path s and this is + + align:start position:0% +emission along the path s and this is + + + align:start position:0% +emission along the path s and this is +the + + align:start position:0% +the + + + align:start position:0% +the +depth from s to S2 where s is wherever + + align:start position:0% +depth from s to S2 where s is wherever + + + align:start position:0% +depth from s to S2 where s is wherever +along the path this radiation has been + + align:start position:0% +along the path this radiation has been + + + align:start position:0% +along the path this radiation has been +emitted this is a complicated equation + + align:start position:0% +emitted this is a complicated equation + + + align:start position:0% +emitted this is a complicated equation +and I'm now going to give you two simple + + align:start position:0% +and I'm now going to give you two simple + + + align:start position:0% +and I'm now going to give you two simple +examples to try and build up your + + align:start position:0% +examples to try and build up your + + + align:start position:0% +examples to try and build up your +intuition for what this equation is + + align:start position:0% +intuition for what this equation is + + + align:start position:0% +intuition for what this equation is +saying if you don't think it's + + align:start position:0% +saying if you don't think it's + + + align:start position:0% +saying if you don't think it's +complicated well L um I think it's quite + + align:start position:0% +complicated well L um I think it's quite + + + align:start position:0% +complicated well L um I think it's quite +a complication equ especially what these + + align:start position:0% +a complication equ especially what these + + + align:start position:0% +a complication equ especially what these +tow are doing here any questions on it + + align:start position:0% +tow are doing here any questions on it + + + align:start position:0% +tow are doing here any questions on it +though before we keep + + align:start position:0% +though before we keep + + + align:start position:0% +though before we keep +going + + align:start position:0% +going + + + align:start position:0% +going +yeah um so for the emission along s term + + align:start position:0% +yeah um so for the emission along s term + + + align:start position:0% +yeah um so for the emission along s term +um if we're wondering about what's you + + align:start position:0% +um if we're wondering about what's you + + + align:start position:0% +um if we're wondering about what's you +know appearing at the at the point S2 + + align:start position:0% +know appearing at the at the point S2 + + + align:start position:0% +know appearing at the at the point S2 +I'm guess some confused why we don't + + align:start position:0% +I'm guess some confused why we don't + + + align:start position:0% +I'm guess some confused why we don't +care about the the angle that that ised + + align:start position:0% +care about the the angle that that ised + + + align:start position:0% +care about the the angle that that ised +from right if it's emitted back along + + align:start position:0% +from right if it's emitted back along + + + align:start position:0% +from right if it's emitted back along +the path then that right it's not + + align:start position:0% +the path then that right it's not + + + align:start position:0% +the path then that right it's not +heading towards S2 you know what I mean + + align:start position:0% +heading towards S2 you know what I mean + + + align:start position:0% +heading towards S2 you know what I mean +like I guess where is that dependence + + align:start position:0% +like I guess where is that dependence + + + align:start position:0% +like I guess where is that dependence +there right so the question was where is + + align:start position:0% +there right so the question was where is + + + align:start position:0% +there right so the question was where is +like the direction of the emission uh + + align:start position:0% +like the direction of the emission uh + + + align:start position:0% +like the direction of the emission uh +featuring into this equation and the + + align:start position:0% +featuring into this equation and the + + + align:start position:0% +featuring into this equation and the +question is because when we're talking + + align:start position:0% +question is because when we're talking + + + align:start position:0% +question is because when we're talking +about the emissivity we said that it's + + align:start position:0% +about the emissivity we said that it's + + + align:start position:0% +about the emissivity we said that it's +into some uh solid angle so we could + + align:start position:0% +into some uh solid angle so we could + + + align:start position:0% +into some uh solid angle so we could +imagine that this emissivity has like an + + align:start position:0% +imagine that this emissivity has like an + + + align:start position:0% +imagine that this emissivity has like an +angle with respect to the magnetic field + + align:start position:0% +angle with respect to the magnetic field + + + align:start position:0% +angle with respect to the magnetic field +right and that would be a perfectly + + align:start position:0% +right and that would be a perfectly + + + align:start position:0% +right and that would be a perfectly +reasonable thing to think about and + + align:start position:0% +reasonable thing to think about and + + + align:start position:0% +reasonable thing to think about and +indeed this is where I've started + + align:start position:0% +indeed this is where I've started + + + align:start position:0% +indeed this is where I've started +slipping into a sort of straight line + + align:start position:0% +slipping into a sort of straight line + + + align:start position:0% +slipping into a sort of straight line +kind of picture and also like an + + align:start position:0% +kind of picture and also like an + + + align:start position:0% +kind of picture and also like an +isotropic emission kind of picture if + + align:start position:0% +isotropic emission kind of picture if + + + align:start position:0% +isotropic emission kind of picture if +you want to do this properly all of + + align:start position:0% +you want to do this properly all of + + + align:start position:0% +you want to do this properly all of +these things that are scaler start to + + align:start position:0% +these things that are scaler start to + + + align:start position:0% +these things that are scaler start to +become vector or you know even worse + + align:start position:0% +become vector or you know even worse + + + align:start position:0% +become vector or you know even worse +some sort of horrific tensor and things + + align:start position:0% +some sort of horrific tensor and things + + + align:start position:0% +some sort of horrific tensor and things +like that and you have to account for + + align:start position:0% +like that and you have to account for + + + align:start position:0% +like that and you have to account for +all of that properly so just to try and + + align:start position:0% +all of that properly so just to try and + + + align:start position:0% +all of that properly so just to try and +simplify this and can do that but you're + + align:start position:0% +simplify this and can do that but you're + + + align:start position:0% +simplify this and can do that but you're +right if you're dealing with a mission + + align:start position:0% +right if you're dealing with a mission + + + align:start position:0% +right if you're dealing with a mission +that is an isotropic like electron cyron + + align:start position:0% +that is an isotropic like electron cyron + + + align:start position:0% +that is an isotropic like electron cyron +emission that might be very important + + align:start position:0% +emission that might be very important + + + align:start position:0% +emission that might be very important +yeah another question from shop + + align:start position:0% +yeah another question from shop + + + align:start position:0% +yeah another question from shop +an integral over the yeah a little + + align:start position:0% +an integral over the yeah a little + + + align:start position:0% +an integral over the yeah a little +confused how like how inside the + + align:start position:0% +confused how like how inside the + + + align:start position:0% +confused how like how inside the +exponential inside the integral is this + + align:start position:0% +exponential inside the integral is this + + + align:start position:0% +exponential inside the integral is this +a sub integral to be evaluated before + + align:start position:0% +a sub integral to be evaluated before + + + align:start position:0% +a sub integral to be evaluated before +you evaluate true + + align:start position:0% + + + + align:start position:0% + +integral uh I think there needs to be + + align:start position:0% +integral uh I think there needs to be + + + align:start position:0% +integral uh I think there needs to be +some f primes and things like that in + + align:start position:0% +some f primes and things like that in + + + align:start position:0% +some f primes and things like that in +order to do this you're certainly going + + align:start position:0% +order to do this you're certainly going + + + align:start position:0% +order to do this you're certainly going +to evaluate this Tow and it's going to + + align:start position:0% +to evaluate this Tow and it's going to + + + align:start position:0% +to evaluate this Tow and it's going to +be evaluated based on whereabouts in + + align:start position:0% +be evaluated based on whereabouts in + + + align:start position:0% +be evaluated based on whereabouts in +this integral s you are so as you're + + align:start position:0% +this integral s you are so as you're + + + align:start position:0% +this integral s you are so as you're +incrementing s here this tow is going to + + align:start position:0% +incrementing s here this tow is going to + + + align:start position:0% +incrementing s here this tow is going to +be evaluated from for + + align:start position:0% +be evaluated from for + + + align:start position:0% +be evaluated from for +example whatever is halfway between s + + align:start position:0% +example whatever is halfway between s + + + align:start position:0% +example whatever is halfway between s +one.5 to S of two where the end point of + + align:start position:0% +one.5 to S of two where the end point of + + + align:start position:0% +one.5 to S of two where the end point of +this Tower is fixed already um I don't + + align:start position:0% +this Tower is fixed already um I don't + + + align:start position:0% +this Tower is fixed already um I don't +think I gave very good explanation of + + align:start position:0% +think I gave very good explanation of + + + align:start position:0% +think I gave very good explanation of +that I think probably if I went back and + + align:start position:0% +that I think probably if I went back and + + + align:start position:0% +that I think probably if I went back and +did this more rigorously I put some more + + align:start position:0% +did this more rigorously I put some more + + + align:start position:0% +did this more rigorously I put some more +primes on this we have integral + + align:start position:0% + + + + align:start position:0% + +okay other questions yeah I see + + align:start position:0% +okay other questions yeah I see + + + align:start position:0% +okay other questions yeah I see +Nicol the that the radiation takes + + align:start position:0% +Nicol the that the radiation takes + + + align:start position:0% +Nicol the that the radiation takes +through the plasma is going to depend on + + align:start position:0% +through the plasma is going to depend on + + + align:start position:0% +through the plasma is going to depend on +the radiation itself right so it's going + + align:start position:0% +the radiation itself right so it's going + + + align:start position:0% +the radiation itself right so it's going +to depend on what kind of radiation it + + align:start position:0% +to depend on what kind of radiation it + + + align:start position:0% +to depend on what kind of radiation it +is uh yeah could be so if you're a + + align:start position:0% +is uh yeah could be so if you're a + + + align:start position:0% +is uh yeah could be so if you're a +different frequency you might have a + + align:start position:0% +different frequency you might have a + + + align:start position:0% +different frequency you might have a +different refractive index so you'd have + + align:start position:0% +different refractive index so you'd have + + + align:start position:0% +different refractive index so you'd have +a different bending yes exactly but in + + align:start position:0% +a different bending yes exactly but in + + + align:start position:0% +a different bending yes exactly but in +this equation the bth kind of + + align:start position:0% +this equation the bth kind of + + + align:start position:0% +this equation the bth kind of +predetermined so it doesn't like we're + + align:start position:0% +predetermined so it doesn't like we're + + + align:start position:0% +predetermined so it doesn't like we're +saying that if we know that the path is + + align:start position:0% +saying that if we know that the path is + + + align:start position:0% +saying that if we know that the path is +this this is how we would + + align:start position:0% +this this is how we would + + + align:start position:0% +this this is how we would +Cate right but the pa the the path of + + align:start position:0% +Cate right but the pa the the path of + + + align:start position:0% +Cate right but the pa the the path of +the radiation although it does depend on + + align:start position:0% +the radiation although it does depend on + + + align:start position:0% +the radiation although it does depend on +a frequency doesn't depend on the + + align:start position:0% +a frequency doesn't depend on the + + + align:start position:0% +a frequency doesn't depend on the +intensity necessarily and so you can for + + align:start position:0% +intensity necessarily and so you can for + + + align:start position:0% +intensity necessarily and so you can for +a certain frequency you can trace out a + + align:start position:0% +a certain frequency you can trace out a + + + align:start position:0% +a certain frequency you can trace out a +ray through your plasma you'll know what + + align:start position:0% +ray through your plasma you'll know what + + + align:start position:0% +ray through your plasma you'll know what +trajectory it is and then you can go + + align:start position:0% +trajectory it is and then you can go + + + align:start position:0% +trajectory it is and then you can go +back and solve the radiation transport + + align:start position:0% +back and solve the radiation transport + + + align:start position:0% +back and solve the radiation transport +equation along that path + + align:start position:0% +equation along that path + + + align:start position:0% +equation along that path +and all the emissivity and opacity + + align:start position:0% +and all the emissivity and opacity + + + align:start position:0% +and all the emissivity and opacity +figures for that + + align:start position:0% +figures for that + + + align:start position:0% +figures for that +particular frequency that we yes at the + + align:start position:0% +particular frequency that we yes at the + + + align:start position:0% +particular frequency that we yes at the +moment we're splitting it up so you + + align:start position:0% +moment we're splitting it up so you + + + align:start position:0% +moment we're splitting it up so you +could solve this for all any different + + align:start position:0% +could solve this for all any different + + + align:start position:0% +could solve this for all any different +frequencies you want and they don't + + align:start position:0% +frequencies you want and they don't + + + align:start position:0% +frequencies you want and they don't +interact in this simple model here yeah + + align:start position:0% +interact in this simple model here yeah + + + align:start position:0% +interact in this simple model here yeah +okay um when you're answering Sean's + + align:start position:0% +okay um when you're answering Sean's + + + align:start position:0% +okay um when you're answering Sean's +question I'm a little confused about how + + align:start position:0% +question I'm a little confused about how + + + align:start position:0% +question I'm a little confused about how +the like s 1.5 Works into the balance of + + align:start position:0% +the like s 1.5 Works into the balance of + + + align:start position:0% +the like s 1.5 Works into the balance of +the to integral um you know like what is + + align:start position:0% +the to integral um you know like what is + + + align:start position:0% +the to integral um you know like what is +if you're providing with some s + + align:start position:0% +if you're providing with some s + + + align:start position:0% +if you're providing with some s +integrate up what's the starting s or if + + align:start position:0% +integrate up what's the starting s or if + + + align:start position:0% +integrate up what's the starting s or if +you're providing it starting s what's + + align:start position:0% +you're providing it starting s what's + + + align:start position:0% +you're providing it starting s what's +your ending s in that to integral so in + + align:start position:0% +your ending s in that to integral so in + + + align:start position:0% +your ending s in that to integral so in +this integral it's an indefinite + + align:start position:0% +this integral it's an indefinite + + + align:start position:0% +this integral it's an indefinite +integral so we not provided any limits + + align:start position:0% +integral so we not provided any limits + + + align:start position:0% +integral so we not provided any limits +what all at all on this the limits only + + align:start position:0% +what all at all on this the limits only + + + align:start position:0% +what all at all on this the limits only +come when you start specifying the end + + align:start position:0% +come when you start specifying the end + + + align:start position:0% +come when you start specifying the end +points so for example here we completely + + align:start position:0% +points so for example here we completely + + + align:start position:0% +points so for example here we completely +specified both the start and the ends to + + align:start position:0% +specified both the start and the ends to + + + align:start position:0% +specified both the start and the ends to +one and to two and that integral is + + align:start position:0% +one and to two and that integral is + + + align:start position:0% +one and to two and that integral is +going to look + + align:start position:0% +going to look + + + align:start position:0% +going to look +like this is going to just look like e + + align:start position:0% +like this is going to just look like e + + + align:start position:0% +like this is going to just look like e +to the integral of alpha DS from S1 2 S2 + + align:start position:0% +to the integral of alpha DS from S1 2 S2 + + + align:start position:0% +to the integral of alpha DS from S1 2 S2 +this is this is equivalent these two are + + align:start position:0% +this is this is equivalent these two are + + + align:start position:0% +this is this is equivalent these two are +equivalent here in this case for Town + + align:start position:0% +equivalent here in this case for Town + + + align:start position:0% +equivalent here in this case for Town +two at the moment what we've got here we + + align:start position:0% +two at the moment what we've got here we + + + align:start position:0% +two at the moment what we've got here we +don't really have the lower bound so we + + align:start position:0% +don't really have the lower bound so we + + + align:start position:0% +don't really have the lower bound so we +have e to the integral of s to S2 of + + align:start position:0% +have e to the integral of s to S2 of + + + align:start position:0% +have e to the integral of s to S2 of +alpha DS like that where the actual s + + align:start position:0% +alpha DS like that where the actual s + + + align:start position:0% +alpha DS like that where the actual s +that we put in the bottom here depends + + align:start position:0% +that we put in the bottom here depends + + + align:start position:0% +that we put in the bottom here depends +on whereabouts and evaluating the syal + + align:start position:0% +on whereabouts and evaluating the syal + + + align:start position:0% +on whereabouts and evaluating the syal +we actually are maybe that also might + + align:start position:0% +we actually are maybe that also might + + + align:start position:0% +we actually are maybe that also might +answer Sean's question I don't know okay + + align:start position:0% +answer Sean's question I don't know okay + + + align:start position:0% +answer Sean's question I don't know okay +good thank you for teasing that out so + + align:start position:0% +good thank you for teasing that out so + + + align:start position:0% +good thank you for teasing that out so +yeah okay U just any questions + + align:start position:0% + + + + align:start position:0% + +online okay n is it possible that + + align:start position:0% +online okay n is it possible that + + + align:start position:0% +online okay n is it possible that +radiation emitted from outside of that + + align:start position:0% +radiation emitted from outside of that + + + align:start position:0% +radiation emitted from outside of that +line would end up kind of joining that + + align:start position:0% +line would end up kind of joining that + + + align:start position:0% +line would end up kind of joining that +same rate yes it could do and we + + align:start position:0% +same rate yes it could do and we + + + align:start position:0% +same rate yes it could do and we +not in in this case + + align:start position:0% +not in in this case + + + align:start position:0% +not in in this case +no what we're going to do in an awful + + align:start position:0% +no what we're going to do in an awful + + + align:start position:0% +no what we're going to do in an awful +lot of this is assume that the radiation + + align:start position:0% +lot of this is assume that the radiation + + + align:start position:0% +lot of this is assume that the radiation +is moving in straight lines in which + + align:start position:0% +is moving in straight lines in which + + + align:start position:0% +is moving in straight lines in which +case it won't cross um the reason is + + align:start position:0% +case it won't cross um the reason is + + + align:start position:0% +case it won't cross um the reason is +because this is already complicated + + align:start position:0% +because this is already complicated + + + align:start position:0% +because this is already complicated +enough to solve without that if you need + + align:start position:0% +enough to solve without that if you need + + + align:start position:0% +enough to solve without that if you need +to solve it with that then you do but if + + align:start position:0% +to solve it with that then you do but if + + + align:start position:0% +to solve it with that then you do but if +you're dealing with like if you're + + align:start position:0% +you're dealing with like if you're + + + align:start position:0% +you're dealing with like if you're +dealing with something like an x-ray + + align:start position:0% +dealing with something like an x-ray + + + align:start position:0% +dealing with something like an x-ray +going through a toac plasma the we are + + align:start position:0% +going through a toac plasma the we are + + + align:start position:0% +going through a toac plasma the we are +so far away from the critical density + + align:start position:0% +so far away from the critical density + + + align:start position:0% +so far away from the critical density +with an x-ray that the refractive index + + align:start position:0% +with an x-ray that the refractive index + + + align:start position:0% +with an x-ray that the refractive index +is unity and it doesn't change and so + + align:start position:0% +is unity and it doesn't change and so + + + align:start position:0% +is unity and it doesn't change and so +therefore they do go in straight lines + + align:start position:0% +therefore they do go in straight lines + + + align:start position:0% +therefore they do go in straight lines +but you're absolutely right you know + + align:start position:0% +but you're absolutely right you know + + + align:start position:0% +but you're absolutely right you know +that you could imagine all sorts of + + align:start position:0% +that you could imagine all sorts of + + + align:start position:0% +that you could imagine all sorts of +radiation coming through Crossing + + align:start position:0% +radiation coming through Crossing + + + align:start position:0% +radiation coming through Crossing +through this point going back to an + + align:start position:0% +through this point going back to an + + + align:start position:0% +through this point going back to an +earlier question that radiation could + + align:start position:0% +earlier question that radiation could + + + align:start position:0% +earlier question that radiation could +heat up a bit of the plasma and then + + align:start position:0% +heat up a bit of the plasma and then + + + align:start position:0% +heat up a bit of the plasma and then +that plasma could then emit in a way + + align:start position:0% +that plasma could then emit in a way + + + align:start position:0% +that plasma could then emit in a way +that you didn't expect before by + + align:start position:0% +that you didn't expect before by + + + align:start position:0% +that you didn't expect before by +changing youru so radiation transport is + + align:start position:0% +changing youru so radiation transport is + + + align:start position:0% +changing youru so radiation transport is +uh is extremely complicated even without + + align:start position:0% +uh is extremely complicated even without + + + align:start position:0% +uh is extremely complicated even without +magnetic fields and then when you put + + align:start position:0% +magnetic fields and then when you put + + + align:start position:0% +magnetic fields and then when you put +the magnetic fields in the whole thing + + align:start position:0% +the magnetic fields in the whole thing + + + align:start position:0% +the magnetic fields in the whole thing +becomes much worse so okay any other + + align:start position:0% +becomes much worse so okay any other + + + align:start position:0% +becomes much worse so okay any other +questions I will give some examples of + + align:start position:0% +questions I will give some examples of + + + align:start position:0% +questions I will give some examples of +this equation so hopefully it will begin + + align:start position:0% +this equation so hopefully it will begin + + + align:start position:0% +this equation so hopefully it will begin +to make more sense but okay let's keep + + align:start position:0% +to make more sense but okay let's keep + + + align:start position:0% +to make more sense but okay let's keep +going on to that good so let's consider + + align:start position:0% +going on to that good so let's consider + + + align:start position:0% +going on to that good so let's consider +a really simple system where we have + + align:start position:0% +a really simple system where we have + + + align:start position:0% +a really simple system where we have +some radiation coming in + + align:start position:0% +some radiation coming in + + + align:start position:0% +some radiation coming in +here we + + align:start position:0% +here we + + + align:start position:0% +here we +have a + + align:start position:0% +have a + + + align:start position:0% +have a +plasma which I'm just going to split up + + align:start position:0% +plasma which I'm just going to split up + + + align:start position:0% +plasma which I'm just going to split up +into two regions here these regions are + + align:start position:0% +into two regions here these regions are + + + align:start position:0% +into two regions here these regions are +actually going to be identical but I + + align:start position:0% +actually going to be identical but I + + + align:start position:0% +actually going to be identical but I +want to show you how the intensity + + align:start position:0% +want to show you how the intensity + + + align:start position:0% +want to show you how the intensity +changes in each of these regions and + + align:start position:0% +changes in each of these regions and + + + align:start position:0% +changes in each of these regions and +then we've got some radiation coming + + align:start position:0% +then we've got some radiation coming + + + align:start position:0% +then we've got some radiation coming +back out + + align:start position:0% + + + + align:start position:0% + +here so uh in this plasma we're going to + + align:start position:0% +here so uh in this plasma we're going to + + + align:start position:0% +here so uh in this plasma we're going to +have + + align:start position:0% + + + + align:start position:0% + +and opacity which is just simply some + + align:start position:0% +and opacity which is just simply some + + + align:start position:0% +and opacity which is just simply some +amount of opacity at a single + + align:start position:0% +amount of opacity at a single + + + align:start position:0% +amount of opacity at a single +frequency new1 and we're going to have + + align:start position:0% +frequency new1 and we're going to have + + + align:start position:0% +frequency new1 and we're going to have +some + + align:start position:0% +some + + + align:start position:0% +some +emissivity which is simply some amount + + align:start position:0% +emissivity which is simply some amount + + + align:start position:0% +emissivity which is simply some amount +of emission at a different + + align:start position:0% +of emission at a different + + + align:start position:0% +of emission at a different +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +new2 like + + align:start position:0% +new2 like + + + align:start position:0% +new2 like +this and my initial radiation + + align:start position:0% + + + + align:start position:0% + +that I'm going to put through + + align:start position:0% +that I'm going to put through + + + align:start position:0% +that I'm going to put through +here is just going to have some amount + + align:start position:0% +here is just going to have some amount + + + align:start position:0% +here is just going to have some amount +of a mission at new one here so I've + + align:start position:0% +of a mission at new one here so I've + + + align:start position:0% +of a mission at new one here so I've +really simplified this we effectively we + + align:start position:0% +really simplified this we effectively we + + + align:start position:0% +really simplified this we effectively we +are solving the radiation transport for + + align:start position:0% +are solving the radiation transport for + + + align:start position:0% +are solving the radiation transport for +all frequencies it's just that I come up + + align:start position:0% +all frequencies it's just that I come up + + + align:start position:0% +all frequencies it's just that I come up +with a problem where there are two + + align:start position:0% +with a problem where there are two + + + align:start position:0% +with a problem where there are two +frequencies right so this is much easier + + align:start position:0% +frequencies right so this is much easier + + + align:start position:0% +frequencies right so this is much easier +you can come up with something arbit + + align:start position:0% +you can come up with something arbit + + + align:start position:0% +you can come up with something arbit +more complicated than this if you want + + align:start position:0% +more complicated than this if you want + + + align:start position:0% +more complicated than this if you want +to I just want to point out you're going + + align:start position:0% +to I just want to point out you're going + + + align:start position:0% +to I just want to point out you're going +to find out soon that these two + + align:start position:0% +to find out soon that these two + + + align:start position:0% +to find out soon that these two +uh emissivity and opacity are not + + align:start position:0% +uh emissivity and opacity are not + + + align:start position:0% +uh emissivity and opacity are not +compatible in fact there's a really + + align:start position:0% +compatible in fact there's a really + + + align:start position:0% +compatible in fact there's a really +strong thermodynamic link between the + + align:start position:0% +strong thermodynamic link between the + + + align:start position:0% +strong thermodynamic link between the +two so don't shout at me there this is + + align:start position:0% +two so don't shout at me there this is + + + align:start position:0% +two so don't shout at me there this is +just to make life easier for you right + + align:start position:0% +just to make life easier for you right + + + align:start position:0% +just to make life easier for you right +now but it turns out that you couldn't + + align:start position:0% +now but it turns out that you couldn't + + + align:start position:0% +now but it turns out that you couldn't +physically have a pattern like this + + align:start position:0% +physically have a pattern like this + + + align:start position:0% +physically have a pattern like this +we'll talk about that a little bit okay + + align:start position:0% +we'll talk about that a little bit okay + + + align:start position:0% +we'll talk about that a little bit okay +so what does this look like as we go + + align:start position:0% +so what does this look like as we go + + + align:start position:0% +so what does this look like as we go +through the plasma so at this first step + + align:start position:0% +through the plasma so at this first step + + + align:start position:0% +through the plasma so at this first step +here we're going to absorb some amount + + align:start position:0% +here we're going to absorb some amount + + + align:start position:0% +here we're going to absorb some amount +of the initial radiation which was that + + align:start position:0% +of the initial radiation which was that + + + align:start position:0% +of the initial radiation which was that +new one right so our radiation is going + + align:start position:0% +new one right so our radiation is going + + + align:start position:0% +new one right so our radiation is going +to go down but we're going to pick up + + align:start position:0% +to go down but we're going to pick up + + + align:start position:0% +to go down but we're going to pick up +some amount of + + align:start position:0% +some amount of + + + align:start position:0% +some amount of +radiation at new2 because the plasma is + + align:start position:0% +radiation at new2 because the plasma is + + + align:start position:0% +radiation at new2 because the plasma is +emitted at this next step here this + + align:start position:0% +emitted at this next step here this + + + align:start position:0% +emitted at this next step here this +process continues new one goes down new + + align:start position:0% +process continues new one goes down new + + + align:start position:0% +process continues new one goes down new +two goes up and then finally as we exit + + align:start position:0% +two goes up and then finally as we exit + + + align:start position:0% +two goes up and then finally as we exit +the plasma we might end up with a system + + align:start position:0% +the plasma we might end up with a system + + + align:start position:0% +the plasma we might end up with a system +where new1 is very very small and new2 + + align:start position:0% +where new1 is very very small and new2 + + + align:start position:0% +where new1 is very very small and new2 +is very very large so effectively as + + align:start position:0% +is very very large so effectively as + + + align:start position:0% +is very very large so effectively as +we've gone through the plasma we have + + align:start position:0% +we've gone through the plasma we have + + + align:start position:0% +we've gone through the plasma we have +been absorbing that new1 the size of + + align:start position:0% +been absorbing that new1 the size of + + + align:start position:0% +been absorbing that new1 the size of +that line has gone down and we've been + + align:start position:0% +that line has gone down and we've been + + + align:start position:0% +that line has gone down and we've been +admitting that new2 the size of that + + align:start position:0% +admitting that new2 the size of that + + + align:start position:0% +admitting that new2 the size of that +line has gone up + + align:start position:0% +line has gone up + + + align:start position:0% +line has gone up +here so that's a cartoon example it + + align:start position:0% +here so that's a cartoon example it + + + align:start position:0% +here so that's a cartoon example it +turns out that for this approximation + + align:start position:0% +turns out that for this approximation + + + align:start position:0% +turns out that for this approximation +that the plasma is + + align:start position:0% +that the plasma is + + + align:start position:0% +that the plasma is +homogeneous then we can solve this + + align:start position:0% +homogeneous then we can solve this + + + align:start position:0% +homogeneous then we can solve this +equation analytically as + + align:start position:0% + + + + align:start position:0% + +well um professor + + align:start position:0% +well um professor + + + align:start position:0% +well um professor +yeah so just to clarify um the + + align:start position:0% +yeah so just to clarify um the + + + align:start position:0% +yeah so just to clarify um the +absorption is throughout both sections + + align:start position:0% +absorption is throughout both sections + + + align:start position:0% +absorption is throughout both sections +of the plasma yeah I I split it into I + + align:start position:0% +of the plasma yeah I I split it into I + + + align:start position:0% +of the plasma yeah I I split it into I +split into two sections so I could just + + align:start position:0% +split into two sections so I could just + + + align:start position:0% +split into two sections so I could just +draw the intensity in two places but the + + align:start position:0% +draw the intensity in two places but the + + + align:start position:0% +draw the intensity in two places but the +plasma has uniform properties throughout + + align:start position:0% +plasma has uniform properties throughout + + + align:start position:0% +plasma has uniform properties throughout +so yeah so + + align:start position:0% +so yeah so + + + align:start position:0% +so yeah so +these this applies to both sections and + + align:start position:0% +these this applies to both sections and + + + align:start position:0% +these this applies to both sections and +this applies to both sections like that + + align:start position:0% +this applies to both sections like that + + + align:start position:0% +this applies to both sections like that +yeah good question I thank you okay any + + align:start position:0% +yeah good question I thank you okay any + + + align:start position:0% +yeah good question I thank you okay any +other questions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +um these times I wish had more + + align:start position:0% + + + + align:start position:0% + +blls really want that + + align:start position:0% + + + + align:start position:0% + +equation + + align:start position:0% + + + + align:start position:0% + +yeah have we um assumed anything about + + align:start position:0% +yeah have we um assumed anything about + + + align:start position:0% +yeah have we um assumed anything about +energy conservation in this equation or + + align:start position:0% +energy conservation in this equation or + + + align:start position:0% +energy conservation in this equation or +could your emission like have more + + align:start position:0% +could your emission like have more + + + align:start position:0% +could your emission like have more +energy out than what the I guess so the + + align:start position:0% +energy out than what the I guess so the + + + align:start position:0% +energy out than what the I guess so the +question was have we are we conserving + + align:start position:0% +question was have we are we conserving + + + align:start position:0% +question was have we are we conserving +energy in this equation so explicitly we + + align:start position:0% +energy in this equation so explicitly we + + + align:start position:0% +energy in this equation so explicitly we +are not a conserving energy in this + + align:start position:0% +are not a conserving energy in this + + + align:start position:0% +are not a conserving energy in this +equation the plasma is the source and + + align:start position:0% +equation the plasma is the source and + + + align:start position:0% +equation the plasma is the source and +the sink of the energy any radiation we + + align:start position:0% +the sink of the energy any radiation we + + + align:start position:0% +the sink of the energy any radiation we +lose goes to heating the plasma any + + align:start position:0% +lose goes to heating the plasma any + + + align:start position:0% +lose goes to heating the plasma any +radiation we gain goes to cooling the + + align:start position:0% +radiation we gain goes to cooling the + + + align:start position:0% +radiation we gain goes to cooling the +plasma that's why you would need to + + align:start position:0% +plasma that's why you would need to + + + align:start position:0% +plasma that's why you would need to +couple an energy equation into this to + + align:start position:0% +couple an energy equation into this to + + + align:start position:0% +couple an energy equation into this to +do it properly okay + + align:start position:0% +do it properly okay + + + align:start position:0% +do it properly okay +yeah okay + + align:start position:0% + + + + align:start position:0% + +so put that equation + + align:start position:0% +so put that equation + + + align:start position:0% +so put that equation +there so if we have a system which is + + align:start position:0% +there so if we have a system which is + + + align:start position:0% +there so if we have a system which is +now homogeneous so that + + align:start position:0% +now homogeneous so that + + + align:start position:0% +now homogeneous so that +along + + align:start position:0% + + + + align:start position:0% + +our path + + align:start position:0% +our path + + + align:start position:0% +our path +s this quantity J upon + + align:start position:0% +s this quantity J upon + + + align:start position:0% +s this quantity J upon +Alpha doesn't + + align:start position:0% +Alpha doesn't + + + align:start position:0% +Alpha doesn't +change so again this is just the + + align:start position:0% +change so again this is just the + + + align:start position:0% +change so again this is just the +homogenous + + align:start position:0% + + + + align:start position:0% + +condition we can solve this analytically + + align:start position:0% +condition we can solve this analytically + + + align:start position:0% +condition we can solve this analytically +and we get + + align:start position:0% +and we get + + + align:start position:0% +and we get +that the intensity at Point S2 is equal + + align:start position:0% +that the intensity at Point S2 is equal + + + align:start position:0% +that the intensity at Point S2 is equal +to the intensity of Point S1 attenuated + + align:start position:0% +to the intensity of Point S1 attenuated + + + align:start position:0% +to the intensity of Point S1 attenuated +by a factor e minus Cal to one which is + + align:start position:0% +by a factor e minus Cal to one which is + + + align:start position:0% +by a factor e minus Cal to one which is +as we said before the integral + + align:start position:0% +as we said before the integral + + + align:start position:0% +as we said before the integral +from L to one is equal to the integral + + align:start position:0% +from L to one is equal to the integral + + + align:start position:0% +from L to one is equal to the integral +from S1 to S2 of alpha DS so this is + + align:start position:0% +from S1 to S2 of alpha DS so this is + + + align:start position:0% +from S1 to S2 of alpha DS so this is +just an exponential damping Factor on + + align:start position:0% +just an exponential damping Factor on + + + align:start position:0% +just an exponential damping Factor on +the intensity this is what you would + + align:start position:0% +the intensity this is what you would + + + align:start position:0% +the intensity this is what you would +expect um for some sort of constant + + align:start position:0% +expect um for some sort of constant + + + align:start position:0% +expect um for some sort of constant +opacity through your system the further + + align:start position:0% +opacity through your system the further + + + align:start position:0% +opacity through your system the further +you go uh the more that initial signal + + align:start position:0% +you go uh the more that initial signal + + + align:start position:0% +you go uh the more that initial signal +is going to be down and then we're also + + align:start position:0% +is going to be down and then we're also + + + align:start position:0% +is going to be down and then we're also +going to have a term J upon + + align:start position:0% +going to have a term J upon + + + align:start position:0% +going to have a term J upon +Alpha + + align:start position:0% +Alpha + + + align:start position:0% +Alpha +1us eus T 2 one same again + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +okay and when we look at this equation + + align:start position:0% +okay and when we look at this equation + + + align:start position:0% +okay and when we look at this equation +we can see that there's a strong + + align:start position:0% +we can see that there's a strong + + + align:start position:0% +we can see that there's a strong +dependence on T and so we want to + + align:start position:0% +dependence on T and so we want to + + + align:start position:0% +dependence on T and so we want to +identify two limit which have names one + + align:start position:0% +identify two limit which have names one + + + align:start position:0% +identify two limit which have names one +of which is this T to one the optical + + align:start position:0% +of which is this T to one the optical + + + align:start position:0% +of which is this T to one the optical +depth is much much less than one and the + + align:start position:0% +depth is much much less than one and the + + + align:start position:0% +depth is much much less than one and the +other one is to 2 one is much much more + + align:start position:0% +other one is to 2 one is much much more + + + align:start position:0% +other one is to 2 one is much much more +than one and these are + + align:start position:0% +than one and these are + + + align:start position:0% +than one and these are +called + + align:start position:0% +called + + + align:start position:0% +called +optically + + align:start position:0% +optically + + + align:start position:0% +optically +thin and + + align:start position:0% +thin and + + + align:start position:0% +thin and +optically + + align:start position:0% + + + + align:start position:0% + +thin in these limits this equation redu + + align:start position:0% +thin in these limits this equation redu + + + align:start position:0% +thin in these limits this equation redu +es to either + + align:start position:0% + + + + align:start position:0% + +is2 is equal to I S1 or + + align:start position:0% +is2 is equal to I S1 or + + + align:start position:0% +is2 is equal to I S1 or +I S2 is equal to + + align:start position:0% +I S2 is equal to + + + align:start position:0% +I S2 is equal to +J on Alpha here optically thin + + align:start position:0% +J on Alpha here optically thin + + + align:start position:0% +J on Alpha here optically thin +corresponds to the radiation streaming + + align:start position:0% +corresponds to the radiation streaming + + + align:start position:0% +corresponds to the radiation streaming +through with an being absorbed optically + + align:start position:0% +through with an being absorbed optically + + + align:start position:0% +through with an being absorbed optically +thick corresponds to the radiation being + + align:start position:0% +thick corresponds to the radiation being + + + align:start position:0% +thick corresponds to the radiation being +very very strongly absorbed so in the + + align:start position:0% +very very strongly absorbed so in the + + + align:start position:0% +very very strongly absorbed so in the +optically thick case we have no + + align:start position:0% +optically thick case we have no + + + align:start position:0% +optically thick case we have no +information about the initial intensity + + align:start position:0% +information about the initial intensity + + + align:start position:0% +information about the initial intensity +in the optically thin case uh we only + + align:start position:0% +in the optically thin case uh we only + + + align:start position:0% +in the optically thin case uh we only +have information about the initial + + align:start position:0% +have information about the initial + + + align:start position:0% +have information about the initial +intensity we don't have any added + + align:start position:0% +intensity we don't have any added + + + align:start position:0% +intensity we don't have any added +emission here so people may also call + + align:start position:0% +emission here so people may also call + + + align:start position:0% +emission here so people may also call +these + + align:start position:0% + + + + align:start position:0% + +transparent and + + align:start position:0% + + + + align:start position:0% + +opaque and remember this is a strong + + align:start position:0% +opaque and remember this is a strong + + + align:start position:0% +opaque and remember this is a strong +function of frequency and so you can be + + align:start position:0% +function of frequency and so you can be + + + align:start position:0% +function of frequency and so you can be +optically thin or transparent to X-rays + + align:start position:0% +optically thin or transparent to X-rays + + + align:start position:0% +optically thin or transparent to X-rays +and optically thick or opaque to the + + align:start position:0% +and optically thick or opaque to the + + + align:start position:0% +and optically thick or opaque to the +first and second harmonics of the + + align:start position:0% +first and second harmonics of the + + + align:start position:0% +first and second harmonics of the +electron cyron emission in top of right + + align:start position:0% +electron cyron emission in top of right + + + align:start position:0% +electron cyron emission in top of right +and these are not contradictory we have + + align:start position:0% +and these are not contradictory we have + + + align:start position:0% +and these are not contradictory we have +solved these equations separately for + + align:start position:0% +solved these equations separately for + + + align:start position:0% +solved these equations separately for +every different frequency that we're + + align:start position:0% +every different frequency that we're + + + align:start position:0% +every different frequency that we're +interested in in our + + align:start position:0% +interested in in our + + + align:start position:0% +interested in in our +system now the interesting thing about + + align:start position:0% +system now the interesting thing about + + + align:start position:0% +system now the interesting thing about +this optically thick case is that this + + align:start position:0% +this optically thick case is that this + + + align:start position:0% +this optically thick case is that this +corresponds to a black + + align:start position:0% + + + + align:start position:0% + +body which is a thermodynamic system + + align:start position:0% +body which is a thermodynamic system + + + align:start position:0% +body which is a thermodynamic system +that I'm sure you've stud + + align:start position:0% +that I'm sure you've stud + + + align:start position:0% +that I'm sure you've stud +in which again the radiation is in + + align:start position:0% +in which again the radiation is in + + + align:start position:0% +in which again the radiation is in +equilibrium with uh the temperature + + align:start position:0% +equilibrium with uh the temperature + + + align:start position:0% +equilibrium with uh the temperature +inside the plasma perfect semic + + align:start position:0% +inside the plasma perfect semic + + + align:start position:0% +inside the plasma perfect semic +equilibrium and for a black body we know + + align:start position:0% +equilibrium and for a black body we know + + + align:start position:0% +equilibrium and for a black body we know +a second expression for the intensity + + align:start position:0% +a second expression for the intensity + + + align:start position:0% +a second expression for the intensity +here for black + + align:start position:0% +here for black + + + align:start position:0% +here for black +body I black + + align:start position:0% +body I black + + + align:start position:0% +body I black +body or + + align:start position:0% +body or + + + align:start position:0% +body or +yeah is a function of frequency is equal + + align:start position:0% +yeah is a function of frequency is equal + + + align:start position:0% +yeah is a function of frequency is equal +to a function that's often called B I'm + + align:start position:0% +to a function that's often called B I'm + + + align:start position:0% +to a function that's often called B I'm +guessing the black m and this is equal + + align:start position:0% +guessing the black m and this is equal + + + align:start position:0% +guessing the black m and this is equal +to ^2 + + align:start position:0% +to ^2 + + + align:start position:0% +to ^2 +c^2 Conant H + + align:start position:0% +c^2 Conant H + + + align:start position:0% +c^2 Conant H +new over the exponential of H new upon + + align:start position:0% +new over the exponential of H new upon + + + align:start position:0% +new over the exponential of H new upon +T minus + + align:start position:0% +T minus + + + align:start position:0% +T minus +one or in many cases it suffices to use + + align:start position:0% +one or in many cases it suffices to use + + + align:start position:0% +one or in many cases it suffices to use +the approximation mu^ 2 T upon c^ 2 and + + align:start position:0% +the approximation mu^ 2 T upon c^ 2 and + + + align:start position:0% +the approximation mu^ 2 T upon c^ 2 and +this is valid for H + + align:start position:0% +this is valid for H + + + align:start position:0% +this is valid for H +much much less than T and this is the + + align:start position:0% +much much less than T and this is the + + + align:start position:0% +much much less than T and this is the +clal limit so this was the limit we had + + align:start position:0% +clal limit so this was the limit we had + + + align:start position:0% +clal limit so this was the limit we had +in classical pH for some time and it was + + align:start position:0% +in classical pH for some time and it was + + + align:start position:0% +in classical pH for some time and it was +the violation of this the ultraviolet + + align:start position:0% +the violation of this the ultraviolet + + + align:start position:0% +the violation of this the ultraviolet +catastrophe implied by the fact that as + + align:start position:0% +catastrophe implied by the fact that as + + + align:start position:0% +catastrophe implied by the fact that as +new keeps getting larger you keep + + align:start position:0% +new keeps getting larger you keep + + + align:start position:0% +new keeps getting larger you keep +emitting more radiation that catastrophe + + align:start position:0% +emitting more radiation that catastrophe + + + align:start position:0% +emitting more radiation that catastrophe +is well me to in some part the + + align:start position:0% +is well me to in some part the + + + align:start position:0% +is well me to in some part the +development of quantum mechanics and + + align:start position:0% +development of quantum mechanics and + + + align:start position:0% +development of quantum mechanics and +this Quantum mechanically correct + + align:start position:0% +this Quantum mechanically correct + + + align:start position:0% +this Quantum mechanically correct +correction it just turns out that this + + align:start position:0% +correction it just turns out that this + + + align:start position:0% +correction it just turns out that this +uh is pretty good a rally genes law it's + + align:start position:0% +uh is pretty good a rally genes law it's + + + align:start position:0% +uh is pretty good a rally genes law it's +a pretty good approximation uh for low + + align:start position:0% +a pretty good approximation uh for low + + + align:start position:0% +a pretty good approximation uh for low +frequencies where the frequency is low + + align:start position:0% +frequencies where the frequency is low + + + align:start position:0% +frequencies where the frequency is low +compared the + + align:start position:0% + + + + align:start position:0% + +temperature what is interesting then is + + align:start position:0% +temperature what is interesting then is + + + align:start position:0% +temperature what is interesting then is +we now have two + + align:start position:0% +we now have two + + + align:start position:0% +we now have two +expressions for the optically thick case + + align:start position:0% +expressions for the optically thick case + + + align:start position:0% +expressions for the optically thick case +we have an expression for the black body + + align:start position:0% +we have an expression for the black body + + + align:start position:0% +we have an expression for the black body +radiation and we have an expression + + align:start position:0% +radiation and we have an expression + + + align:start position:0% +radiation and we have an expression +that's the as J upon Alpha and these + + align:start position:0% +that's the as J upon Alpha and these + + + align:start position:0% +that's the as J upon Alpha and these +Expressions must be equal to each other + + align:start position:0% +Expressions must be equal to each other + + + align:start position:0% +Expressions must be equal to each other +and so this means that the emissivity of + + align:start position:0% +and so this means that the emissivity of + + + align:start position:0% +and so this means that the emissivity of +the opacity is equal to I'm just going + + align:start position:0% +the opacity is equal to I'm just going + + + align:start position:0% +the opacity is equal to I'm just going +to use the clage new squ upon c s times + + align:start position:0% +to use the clage new squ upon c s times + + + align:start position:0% +to use the clage new squ upon c s times +the temperature and this is called + + align:start position:0% +the temperature and this is called + + + align:start position:0% +the temperature and this is called +C along with all the other things called + + align:start position:0% + + + + align:start position:0% + +C kof law is very + + align:start position:0% + + + + align:start position:0% + +profound although we derived it in the + + align:start position:0% +profound although we derived it in the + + + align:start position:0% +profound although we derived it in the +limit of an optically thick body it + + align:start position:0% +limit of an optically thick body it + + + align:start position:0% +limit of an optically thick body it +still has to apply into an optically + + align:start position:0% +still has to apply into an optically + + + align:start position:0% +still has to apply into an optically +thin ball and effectively what this says + + align:start position:0% +thin ball and effectively what this says + + + align:start position:0% +thin ball and effectively what this says +is if you know the + + align:start position:0% +is if you know the + + + align:start position:0% +is if you know the +emissivity then you automatically know + + align:start position:0% +emissivity then you automatically know + + + align:start position:0% +emissivity then you automatically know +the opacity these two quantities are + + align:start position:0% +the opacity these two quantities are + + + align:start position:0% +the opacity these two quantities are +intimately related this is why I + + align:start position:0% +intimately related this is why I + + + align:start position:0% +intimately related this is why I +said that this wasn't actually valid + + align:start position:0% +said that this wasn't actually valid + + + align:start position:0% +said that this wasn't actually valid +because this does not obey K's + + align:start position:0% + + + + align:start position:0% + +law so the nice thing about that is you + + align:start position:0% +law so the nice thing about that is you + + + align:start position:0% +law so the nice thing about that is you +only have to calculate the emissivity + + align:start position:0% +only have to calculate the emissivity + + + align:start position:0% +only have to calculate the emissivity +for a system and then you automatically + + align:start position:0% +for a system and then you automatically + + + align:start position:0% +for a system and then you automatically +get the opacity so if you help L J you + + align:start position:0% +get the opacity so if you help L J you + + + align:start position:0% +get the opacity so if you help L J you +get Alpha to three that's rather + + align:start position:0% +get Alpha to three that's rather + + + align:start position:0% +get Alpha to three that's rather +convenient that's nice but maybe the + + align:start position:0% +convenient that's nice but maybe the + + + align:start position:0% +convenient that's nice but maybe the +more profound thing about kop law is the + + align:start position:0% +more profound thing about kop law is the + + + align:start position:0% +more profound thing about kop law is the +fact that where you have high + + align:start position:0% +fact that where you have high + + + align:start position:0% +fact that where you have high +emissivity we also + + align:start position:0% +emissivity we also + + + align:start position:0% +emissivity we also +have high + + align:start position:0% +have high + + + align:start position:0% +have high +capacity what this means is that regions + + align:start position:0% +capacity what this means is that regions + + + align:start position:0% +capacity what this means is that regions +which strong L emit also strongly absorb + + align:start position:0% +which strong L emit also strongly absorb + + + align:start position:0% +which strong L emit also strongly absorb +and that also means that regions regions + + align:start position:0% +and that also means that regions regions + + + align:start position:0% +and that also means that regions regions +which weakly emit do not ah sorry + + align:start position:0% +which weakly emit do not ah sorry + + + align:start position:0% +which weakly emit do not ah sorry +regions which weakly absorb do not + + align:start position:0% +regions which weakly absorb do not + + + align:start position:0% +regions which weakly absorb do not +strongly emit they also weakly emit oh + + align:start position:0% +strongly emit they also weakly emit oh + + + align:start position:0% +strongly emit they also weakly emit oh +that was confusing this is where this + + align:start position:0% +that was confusing this is where this + + + align:start position:0% +that was confusing this is where this +comes in if some of you been staring at + + align:start position:0% +comes in if some of you been staring at + + + align:start position:0% +comes in if some of you been staring at +this being like wait is this obvious the + + align:start position:0% +this being like wait is this obvious the + + + align:start position:0% +this being like wait is this obvious the +point is if you have very very low + + align:start position:0% +point is if you have very very low + + + align:start position:0% +point is if you have very very low +absorption you are also going to have + + align:start position:0% +absorption you are also going to have + + + align:start position:0% +absorption you are also going to have +very very low emission and so you're not + + align:start position:0% +very very low emission and so you're not + + + align:start position:0% +very very low emission and so you're not +going to see significant self emission + + align:start position:0% +going to see significant self emission + + + align:start position:0% +going to see significant self emission +from the plasma being added to your + + align:start position:0% +from the plasma being added to your + + + align:start position:0% +from the plasma being added to your +initial beam radiation and so you might + + align:start position:0% +initial beam radiation and so you might + + + align:start position:0% +initial beam radiation and so you might +think oh perhaps I would get the initial + + align:start position:0% +think oh perhaps I would get the initial + + + align:start position:0% +think oh perhaps I would get the initial +beam plus some extra term well you would + + align:start position:0% +beam plus some extra term well you would + + + align:start position:0% +beam plus some extra term well you would +get an extra term but that term would be + + align:start position:0% +get an extra term but that term would be + + + align:start position:0% +get an extra term but that term would be +proportional to T to one and we've + + align:start position:0% +proportional to T to one and we've + + + align:start position:0% +proportional to T to one and we've +already said to derive this it's much + + align:start position:0% +already said to derive this it's much + + + align:start position:0% +already said to derive this it's much +less than one so that extra radiation + + align:start position:0% +less than one so that extra radiation + + + align:start position:0% +less than one so that extra radiation +wouldn't be very significant compared to + + align:start position:0% +wouldn't be very significant compared to + + + align:start position:0% +wouldn't be very significant compared to +the initial beam put through okay + + align:start position:0% +the initial beam put through okay + + + align:start position:0% +the initial beam put through okay +questions bu in + + align:start position:0% +questions bu in + + + align:start position:0% +questions bu in +theramic Assumption or something like + + align:start position:0% +theramic Assumption or something like + + + align:start position:0% +theramic Assumption or something like +you always have to the same temperature + + align:start position:0% +you always have to the same temperature + + + align:start position:0% +you always have to the same temperature +everywhere along your pack or something + + align:start position:0% +everywhere along your pack or something + + + align:start position:0% +everywhere along your pack or something +like that or is it just no I think K + + align:start position:0% +like that or is it just no I think K + + + align:start position:0% +like that or is it just no I think K +power of K's law is although you derive + + align:start position:0% +power of K's law is although you derive + + + align:start position:0% +power of K's law is although you derive +it using all these black body + + align:start position:0% +it using all these black body + + + align:start position:0% +it using all these black body +assumptions it then works everywhere + + align:start position:0% +assumptions it then works everywhere + + + align:start position:0% +assumptions it then works everywhere +else as well because these two have to + + align:start position:0% +else as well because these two have to + + + align:start position:0% +else as well because these two have to +obey this principle for a black body but + + align:start position:0% +obey this principle for a black body but + + + align:start position:0% +obey this principle for a black body but +it means it also pins it even when + + align:start position:0% +it means it also pins it even when + + + align:start position:0% +it means it also pins it even when +you're not in camic equilibria non loal + + align:start position:0% +you're not in camic equilibria non loal + + + align:start position:0% +you're not in camic equilibria non loal +th equ um yeah so I think that's why + + align:start position:0% +th equ um yeah so I think that's why + + + align:start position:0% +th equ um yeah so I think that's why +it's a powerful result it doesn't just + + align:start position:0% +it's a powerful result it doesn't just + + + align:start position:0% +it's a powerful result it doesn't just +apply + + align:start position:0% +apply + + + align:start position:0% +apply +properly yeah another question say that + + align:start position:0% +properly yeah another question say that + + + align:start position:0% +properly yeah another question say that +you can calculate the um aity and get + + align:start position:0% +you can calculate the um aity and get + + + align:start position:0% +you can calculate the um aity and get +absorption that also repace you know the + + align:start position:0% +absorption that also repace you know the + + + align:start position:0% +absorption that also repace you know the +temperature though right well if you're + + align:start position:0% +temperature though right well if you're + + + align:start position:0% +temperature though right well if you're +going to calculate the emissivity you + + align:start position:0% +going to calculate the emissivity you + + + align:start position:0% +going to calculate the emissivity you +need to know the temperature of your + + align:start position:0% +need to know the temperature of your + + + align:start position:0% +need to know the temperature of your +plasma we haven't got there yet but the + + align:start position:0% +plasma we haven't got there yet but the + + + align:start position:0% +plasma we haven't got there yet but the +emissivity is always going to be a very + + align:start position:0% +emissivity is always going to be a very + + + align:start position:0% +emissivity is always going to be a very +strong function of temperature okay yeah + + align:start position:0% +strong function of temperature okay yeah + + + align:start position:0% +strong function of temperature okay yeah +so so you to calculate the emissivity + + align:start position:0% +so so you to calculate the emissivity + + + align:start position:0% +so so you to calculate the emissivity +you're going to need to know the density + + align:start position:0% +you're going to need to know the density + + + align:start position:0% +you're going to need to know the density +and temperature of your plasma and if + + align:start position:0% +and temperature of your plasma and if + + + align:start position:0% +and temperature of your plasma and if +you want to do it an isotropically + + align:start position:0% +you want to do it an isotropically + + + align:start position:0% +you want to do it an isotropically +you'll need to know like magnetic field + + align:start position:0% +you'll need to know like magnetic field + + + align:start position:0% +you'll need to know like magnetic field +Direction all sorts of fun things like + + align:start position:0% +Direction all sorts of fun things like + + + align:start position:0% +Direction all sorts of fun things like +that but at the very Bas basic we're + + align:start position:0% +that but at the very Bas basic we're + + + align:start position:0% +that but at the very Bas basic we're +going to do breem strum in a little bit + + align:start position:0% +going to do breem strum in a little bit + + + align:start position:0% +going to do breem strum in a little bit +brm stong density squared temperature to + + align:start position:0% +brm stong density squared temperature to + + + align:start position:0% +brm stong density squared temperature to +half right so you need to know those two + + align:start position:0% +half right so you need to know those two + + + align:start position:0% +half right so you need to know those two +things in order to be able get the brst + + align:start position:0% +things in order to be able get the brst + + + align:start position:0% +things in order to be able get the brst +so yeah soe + + align:start position:0% + + + + align:start position:0% + +that we also have AL C + + align:start position:0% + + + + align:start position:0% + +or oh maybe this is more powerful than + + align:start position:0% +or oh maybe this is more powerful than + + + align:start position:0% +or oh maybe this is more powerful than +just simply a homogeneous plasma yeah it + + align:start position:0% +just simply a homogeneous plasma yeah it + + + align:start position:0% +just simply a homogeneous plasma yeah it +looks like if they both go up and down + + align:start position:0% +looks like if they both go up and down + + + align:start position:0% +looks like if they both go up and down +together uh yeah I I I don't think we + + align:start position:0% +together uh yeah I I I don't think we + + + align:start position:0% +together uh yeah I I I don't think we +need to assume that they're actually + + align:start position:0% +need to assume that they're actually + + + align:start position:0% +need to assume that they're actually +homogeneous in order to get this result + + align:start position:0% +homogeneous in order to get this result + + + align:start position:0% +homogeneous in order to get this result +so maybe you're right yeah maybe with + + align:start position:0% +so maybe you're right yeah maybe with + + + align:start position:0% +so maybe you're right yeah maybe with +the as long as J and Alpha increase and + + align:start position:0% +the as long as J and Alpha increase and + + + align:start position:0% +the as long as J and Alpha increase and +decrease together I'm trying to work out + + align:start position:0% +decrease together I'm trying to work out + + + align:start position:0% +decrease together I'm trying to work out +this is is that effec to be a statement + + align:start position:0% +this is is that effec to be a statement + + + align:start position:0% +this is is that effec to be a statement +that the temperature is constant I think + + align:start position:0% +that the temperature is constant I think + + + align:start position:0% +that the temperature is constant I think +it is so the temperature is constant + + align:start position:0% +it is so the temperature is constant + + + align:start position:0% +it is so the temperature is constant +because of this result but I think that + + align:start position:0% +because of this result but I think that + + + align:start position:0% +because of this result but I think that +means the density could + + align:start position:0% +means the density could + + + align:start position:0% +means the density could +change so it's homogeneous in + + align:start position:0% +change so it's homogeneous in + + + align:start position:0% +change so it's homogeneous in +temperature + + align:start position:0% + + + + align:start position:0% + +only okay any questions + + align:start position:0% +only okay any questions + + + align:start position:0% +only okay any questions +online + + align:start position:0% + + + + align:start position:0% + +yeah but this differential equation alal + + align:start position:0% +yeah but this differential equation alal + + + align:start position:0% +yeah but this differential equation alal +Z how is that why do we + + align:start position:0% +Z how is that why do we + + + align:start position:0% +Z how is that why do we +need law conclude that I J and I Alpha + + align:start position:0% +need law conclude that I J and I Alpha + + + align:start position:0% +need law conclude that I J and I Alpha +are the same you know that they increase + + align:start position:0% +are the same you know that they increase + + + align:start position:0% +are the same you know that they increase +and decrease in lock step isn't that + + align:start position:0% +and decrease in lock step isn't that + + + align:start position:0% +and decrease in lock step isn't that +what that differential equation + + align:start position:0% + + + + align:start position:0% + +says this is an assumption this equation + + align:start position:0% +says this is an assumption this equation + + + align:start position:0% +says this is an assumption this equation +here is an assumption that we've made in + + align:start position:0% +here is an assumption that we've made in + + + align:start position:0% +here is an assumption that we've made in +order to + + align:start position:0% +order to + + + align:start position:0% +order to +derve this equation which is + + align:start position:0% +derve this equation which is + + + align:start position:0% +derve this equation which is +particularly simple to understand the + + align:start position:0% +particularly simple to understand the + + + align:start position:0% +particularly simple to understand the +optically Thin and optically Thick + + align:start position:0% +optically Thin and optically Thick + + + align:start position:0% +optically Thin and optically Thick +limits because to is just the linearly + + align:start position:0% +limits because to is just the linearly + + + align:start position:0% +limits because to is just the linearly +increases with distance rather than like + + align:start position:0% +increases with distance rather than like + + + align:start position:0% +increases with distance rather than like +changing rapidly over different bits of + + align:start position:0% +changing rapidly over different bits of + + + align:start position:0% +changing rapidly over different bits of +plasma once we've done that we then make + + align:start position:0% +plasma once we've done that we then make + + + align:start position:0% +plasma once we've done that we then make +we find out for the optical bit case + + align:start position:0% +we find out for the optical bit case + + + align:start position:0% +we find out for the optical bit case +that this is true and then I don't know + + align:start position:0% +that this is true and then I don't know + + + align:start position:0% +that this is true and then I don't know +I don't think it's obvious from the + + align:start position:0% +I don't think it's obvious from the + + + align:start position:0% +I don't think it's obvious from the +start that we were going to end up with + + align:start position:0% +start that we were going to end up with + + + align:start position:0% +start that we were going to end up with +with this result and this result is + + align:start position:0% +with this result and this result is + + + align:start position:0% +with this result and this result is +still true for in homogeneous plasmas as + + align:start position:0% +still true for in homogeneous plasmas as + + + align:start position:0% +still true for in homogeneous plasmas as +well it just happens to be true for we' + + align:start position:0% +well it just happens to be true for we' + + + align:start position:0% +well it just happens to be true for we' +proved it in the case of a homogeneous + + align:start position:0% +proved it in the case of a homogeneous + + + align:start position:0% +proved it in the case of a homogeneous +plasma okay yeah I I think I see your + + align:start position:0% +plasma okay yeah I I think I see your + + + align:start position:0% +plasma okay yeah I I think I see your +question but I don't think we've baked + + align:start position:0% +question but I don't think we've baked + + + align:start position:0% +question but I don't think we've baked +in our result in our assumptions if if + + align:start position:0% +in our result in our assumptions if if + + + align:start position:0% +in our result in our assumptions if if +that's what you're asking yeah I don't + + align:start position:0% +that's what you're asking yeah I don't + + + align:start position:0% +that's what you're asking yeah I don't +think so but yeah okay okay other + + align:start position:0% +think so but yeah okay okay other + + + align:start position:0% +think so but yeah okay okay other +questions anything online anything in + + align:start position:0% +questions anything online anything in + + + align:start position:0% +questions anything online anything in +the + + align:start position:0% + + + + align:start position:0% + +room all right so now what we probably + + align:start position:0% +room all right so now what we probably + + + align:start position:0% +room all right so now what we probably +want to do is calculate + + align:start position:0% + + + + align:start position:0% + +J for a variety of different cases so we + + align:start position:0% +J for a variety of different cases so we + + + align:start position:0% +J for a variety of different cases so we +can calculate J the emissivity from + + align:start position:0% +can calculate J the emissivity from + + + align:start position:0% +can calculate J the emissivity from +three electrons what sort of radiation + + align:start position:0% +three electrons what sort of radiation + + + align:start position:0% +three electrons what sort of radiation +do we get from three + + align:start position:0% + + + + align:start position:0% + +electrons RS + + align:start position:0% + + + + align:start position:0% + +okay anything + + align:start position:0% +okay anything + + + align:start position:0% +okay anything +else synon synchron we're not going to + + align:start position:0% +else synon synchron we're not going to + + + align:start position:0% +else synon synchron we're not going to +do + + align:start position:0% +do + + + align:start position:0% +do +synchron compon + + align:start position:0% +synchron compon + + + align:start position:0% +synchron compon +scattering compson scattering oh no um + + align:start position:0% +scattering compson scattering oh no um + + + align:start position:0% +scattering compson scattering oh no um +Compton Compton scattering compson + + align:start position:0% +Compton Compton scattering compson + + + align:start position:0% +Compton Compton scattering compson +scattering is just relativistic Thompson + + align:start position:0% +scattering is just relativistic Thompson + + + align:start position:0% +scattering is just relativistic Thompson +scattering um so we're not going to + + align:start position:0% +scattering um so we're not going to + + + align:start position:0% +scattering um so we're not going to +consider that because that is scattering + + align:start position:0% +consider that because that is scattering + + + align:start position:0% +consider that because that is scattering +of radiation + + align:start position:0% +of radiation + + + align:start position:0% +of radiation +from external radiation by the plasma uh + + align:start position:0% +from external radiation by the plasma uh + + + align:start position:0% +from external radiation by the plasma uh +so we're talking about radiation being + + align:start position:0% +so we're talking about radiation being + + + align:start position:0% +so we're talking about radiation being +produced by the plasma here but it's + + align:start position:0% +produced by the plasma here but it's + + + align:start position:0% +produced by the plasma here but it's +it's a good point um we will talk about + + align:start position:0% +it's a good point um we will talk about + + + align:start position:0% +it's a good point um we will talk about +scattering extensively later on um but + + align:start position:0% +scattering extensively later on um but + + + align:start position:0% +scattering extensively later on um but +not in this case yeah anything else + + align:start position:0% +not in this case yeah anything else + + + align:start position:0% +not in this case yeah anything else +recombination recombination + + align:start position:0% +recombination recombination + + + align:start position:0% +recombination recombination +yeah starts with a free electron Beast + + align:start position:0% +yeah starts with a free electron Beast + + + align:start position:0% +yeah starts with a free electron Beast +so it + + align:start position:0% + + + + align:start position:0% + +counts anything + + align:start position:0% + + + + align:start position:0% + +else uh Lam more radiation or does that + + align:start position:0% +else uh Lam more radiation or does that + + + align:start position:0% +else uh Lam more radiation or does that +just kind of yeah cyron radiation to be + + align:start position:0% +just kind of yeah cyron radiation to be + + + align:start position:0% +just kind of yeah cyron radiation to be +honest if that's the same a syncron that + + align:start position:0% +honest if that's the same a syncron that + + + align:start position:0% +honest if that's the same a syncron that +explains synchron that explains a lot so + + align:start position:0% +explains synchron that explains a lot so + + + align:start position:0% +explains synchron that explains a lot so +I've always been confused about that but + + align:start position:0% +I've always been confused about that but + + + align:start position:0% +I've always been confused about that but +we're definitely doing cyron so the same + + align:start position:0% +we're definitely doing cyron so the same + + + align:start position:0% +we're definitely doing cyron so the same +think is it one the relativistic version + + align:start position:0% +think is it one the relativistic version + + + align:start position:0% +think is it one the relativistic version +of the other they're definitely related + + align:start position:0% +of the other they're definitely related + + + align:start position:0% +of the other they're definitely related +any any free positrons think what would + + align:start position:0% +any any free positrons think what would + + + align:start position:0% +any any free positrons think what would +what would we get if we had free + + align:start position:0% +what would we get if we had free + + + align:start position:0% +what would we get if we had free +positrons you know yeah okay so we're + + align:start position:0% +positrons you know yeah okay so we're + + + align:start position:0% +positrons you know yeah okay so we're +not going to do that but that would be + + align:start position:0% +not going to do that but that would be + + + align:start position:0% +not going to do that but that would be +cool yeah no no no no no like that's + + align:start position:0% +cool yeah no no no no no like that's + + + align:start position:0% +cool yeah no no no no no like that's +that that would be neat we're not going + + align:start position:0% +that that would be neat we're not going + + + align:start position:0% +that that would be neat we're not going +to drive that it's a little bit terminal + + align:start position:0% +to drive that it's a little bit terminal + + + align:start position:0% +to drive that it's a little bit terminal +for the plaz isn't + + align:start position:0% +for the plaz isn't + + + align:start position:0% +for the plaz isn't +it yeah uh that that's all I've got here + + align:start position:0% +it yeah uh that that's all I've got here + + + align:start position:0% +it yeah uh that that's all I've got here +um and then we'll also do this for bound + + align:start position:0% +um and then we'll also do this for bound + + + align:start position:0% +um and then we'll also do this for bound +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +and really for bound electrons this is + + align:start position:0% +and really for bound electrons this is + + + align:start position:0% +and really for bound electrons this is +the whole zoo of line + + align:start position:0% + + + + align:start position:0% + +emission I think I've be very + + align:start position:0% +emission I think I've be very + + + align:start position:0% +emission I think I've be very +inconsistent whether I've put two M's or + + align:start position:0% +inconsistent whether I've put two M's or + + + align:start position:0% +inconsistent whether I've put two M's or +one m in Mission throughout this lecture + + align:start position:0% +one m in Mission throughout this lecture + + + align:start position:0% +one m in Mission throughout this lecture +so you can tell how good my spelling + + align:start position:0% +so you can tell how good my spelling + + + align:start position:0% +so you can tell how good my spelling +okay now in a previous version of this + + align:start position:0% +okay now in a previous version of this + + + align:start position:0% +okay now in a previous version of this +course we went through all of these + + align:start position:0% +course we went through all of these + + + align:start position:0% +course we went through all of these +without talking at any point about what + + align:start position:0% +without talking at any point about what + + + align:start position:0% +without talking at any point about what +you'd actually do with it and I found + + align:start position:0% +you'd actually do with it and I found + + + align:start position:0% +you'd actually do with it and I found +this uh very difficult to teach so what + + align:start position:0% +this uh very difficult to teach so what + + + align:start position:0% +this uh very difficult to teach so what +we're going to do is going to cover each + + align:start position:0% +we're going to do is going to cover each + + + align:start position:0% +we're going to do is going to cover each +of these topics sort of in turn and then + + align:start position:0% +of these topics sort of in turn and then + + + align:start position:0% +of these topics sort of in turn and then +interject with like here's how a Bomer + + align:start position:0% +interject with like here's how a Bomer + + + align:start position:0% +interject with like here's how a Bomer +works or here's how a pinhole camera + + align:start position:0% +works or here's how a pinhole camera + + + align:start position:0% +works or here's how a pinhole camera +works or here's how a spectrometer works + + align:start position:0% +works or here's how a spectrometer works + + + align:start position:0% +works or here's how a spectrometer works +but the point is that all of the + + align:start position:0% +but the point is that all of the + + + align:start position:0% +but the point is that all of the +techniques I'll discuss are applicable + + align:start position:0% +techniques I'll discuss are applicable + + + align:start position:0% +techniques I'll discuss are applicable +to all of these different types of + + align:start position:0% +to all of these different types of + + + align:start position:0% +to all of these different types of +radiation I'm just trying to break it up + + align:start position:0% +radiation I'm just trying to break it up + + + align:start position:0% +radiation I'm just trying to break it up +so it's not like learn every type of + + align:start position:0% +so it's not like learn every type of + + + align:start position:0% +so it's not like learn every type of +radiation and then learn every type of + + align:start position:0% +radiation and then learn every type of + + + align:start position:0% +radiation and then learn every type of +diagnosing radiation but we will start + + align:start position:0% +diagnosing radiation but we will start + + + align:start position:0% +diagnosing radiation but we will start +as Hutchinson does with + + align:start position:0% + + + + align:start position:0% + +cyron + + align:start position:0% +cyron + + + align:start position:0% +cyron +but before that I have a little question + + align:start position:0% +but before that I have a little question + + + align:start position:0% +but before that I have a little question +for you about something that I thought + + align:start position:0% +for you about something that I thought + + + align:start position:0% +for you about something that I thought +about in the shower the other day and + + align:start position:0% +about in the shower the other day and + + + align:start position:0% +about in the shower the other day and +thought I wonder if this is obvious or + + align:start position:0% +thought I wonder if this is obvious or + + + align:start position:0% +thought I wonder if this is obvious or +not and you can tell me whether or not + + align:start position:0% +not and you can tell me whether or not + + + align:start position:0% +not and you can tell me whether or not +it's obvious and my question for you + + align:start position:0% + + + + align:start position:0% + +is we've encounted two places in which + + align:start position:0% +is we've encounted two places in which + + + align:start position:0% +is we've encounted two places in which +radiation ceases to go through a plasma + + align:start position:0% +radiation ceases to go through a plasma + + + align:start position:0% +radiation ceases to go through a plasma +right we have found a limit where the + + align:start position:0% +right we have found a limit where the + + + align:start position:0% +right we have found a limit where the +optical depth is much much greater than + + align:start position:0% +optical depth is much much greater than + + + align:start position:0% +optical depth is much much greater than +one so that's particularly + + align:start position:0% + + + + align:start position:0% + +thick and we've also talked about a cut + + align:start position:0% +thick and we've also talked about a cut + + + align:start position:0% +thick and we've also talked about a cut +off that's where the reflective index is + + align:start position:0% +off that's where the reflective index is + + + align:start position:0% +off that's where the reflective index is +less than + + align:start position:0% + + + + align:start position:0% + +zero right in the context of plasma + + align:start position:0% +zero right in the context of plasma + + + align:start position:0% +zero right in the context of plasma +remember we might have n is 1 minus NE + + align:start position:0% +remember we might have n is 1 minus NE + + + align:start position:0% +remember we might have n is 1 minus NE +over 2 C and so when we get close to N + + align:start position:0% +over 2 C and so when we get close to N + + + align:start position:0% +over 2 C and so when we get close to N +critical the wave is cut off and that + + align:start position:0% +critical the wave is cut off and that + + + align:start position:0% +critical the wave is cut off and that +also appeared to stop the radiation + + align:start position:0% +also appeared to stop the radiation + + + align:start position:0% +also appeared to stop the radiation +going so what I want to ask you is are + + align:start position:0% +going so what I want to ask you is are + + + align:start position:0% +going so what I want to ask you is are +these two things the + + align:start position:0% +these two things the + + + align:start position:0% +these two things the +same and if not why they + + align:start position:0% + + + + align:start position:0% + +not St there's not the same reason being + + align:start position:0% +not St there's not the same reason being + + + align:start position:0% +not St there's not the same reason being +that the O case includes absorption but + + align:start position:0% +that the O case includes absorption but + + + align:start position:0% +that the O case includes absorption but +not reflection whereas less zero case + + align:start position:0% +not reflection whereas less zero case + + + align:start position:0% +not reflection whereas less zero case +can be + + align:start position:0% +can be + + + align:start position:0% +can be +reflection okay so let's start ring down + + align:start position:0% +reflection okay so let's start ring down + + + align:start position:0% +reflection okay so let's start ring down +to differences I agree with you I don't + + align:start position:0% +to differences I agree with you I don't + + + align:start position:0% +to differences I agree with you I don't +think they are the same so here we have + + align:start position:0% +think they are the same so here we have + + + align:start position:0% +think they are the same so here we have +reflection there's no energy absorbed at + + align:start position:0% +reflection there's no energy absorbed at + + + align:start position:0% +reflection there's no energy absorbed at +least in our sort of wkb picture of this + + align:start position:0% +least in our sort of wkb picture of this + + + align:start position:0% +least in our sort of wkb picture of this +there might be reality here we just have + + align:start position:0% + + + + align:start position:0% + +absorption what happens to the wave in + + align:start position:0% +absorption what happens to the wave in + + + align:start position:0% +absorption what happens to the wave in +these two cases the electric what + + align:start position:0% +these two cases the electric what + + + align:start position:0% +these two cases the electric what +happens to the electric field in these + + align:start position:0% +happens to the electric field in these + + + align:start position:0% +happens to the electric field in these +two + + align:start position:0% + + + + align:start position:0% + +cases okay so in both cases okay what + + align:start position:0% +cases okay so in both cases okay what + + + align:start position:0% +cases okay so in both cases okay what +happens to the electric field I guess + + align:start position:0% +happens to the electric field I guess + + + align:start position:0% +happens to the electric field I guess +um we have our critical surface here our + + align:start position:0% +um we have our critical surface here our + + + align:start position:0% +um we have our critical surface here our +wave is coming + + align:start position:0% +wave is coming + + + align:start position:0% +wave is coming +in what happens to the electric field + + align:start position:0% +in what happens to the electric field + + + align:start position:0% +in what happens to the electric field +past the critical surface in the case of + + align:start position:0% +past the critical surface in the case of + + + align:start position:0% +past the critical surface in the case of +a cutter it can't propagate it can't + + align:start position:0% +a cutter it can't propagate it can't + + + align:start position:0% +a cutter it can't propagate it can't +propagate so what does it do instead + + align:start position:0% +propagate so what does it do instead + + + align:start position:0% +propagate so what does it do instead +reflect is there no electric field esses + + align:start position:0% +reflect is there no electric field esses + + + align:start position:0% +reflect is there no electric field esses +it esses so what does it do Decay + + align:start position:0% +it esses so what does it do Decay + + + align:start position:0% +it esses so what does it do Decay +exponentially decays exponentially an + + align:start position:0% +exponentially decays exponentially an + + + align:start position:0% +exponentially decays exponentially an +function somewhere okay so this and this + + align:start position:0% +function somewhere okay so this and this + + + align:start position:0% +function somewhere okay so this and this +is because our refractive index is less + + align:start position:0% +is because our refractive index is less + + + align:start position:0% +is because our refractive index is less +than zero our refractive index is + + align:start position:0% +than zero our refractive index is + + + align:start position:0% +than zero our refractive index is +defined + + align:start position:0% +defined + + + align:start position:0% +defined +as k 2 over Omega S c^ 2 like this Omega + + align:start position:0% +as k 2 over Omega S c^ 2 like this Omega + + + align:start position:0% +as k 2 over Omega S c^ 2 like this Omega +and C are positive which means that k s + + align:start position:0% +and C are positive which means that k s + + + align:start position:0% +and C are positive which means that k s +is less than zero which means we can + + align:start position:0% +is less than zero which means we can + + + align:start position:0% +is less than zero which means we can +Define some qu + + align:start position:0% +Define some qu + + + align:start position:0% +Define some qu +which I'm going to write is like very + + align:start position:0% +which I'm going to write is like very + + + align:start position:0% +which I'm going to write is like very +exaggerated Kappa to try make it look + + align:start position:0% +exaggerated Kappa to try make it look + + + align:start position:0% +exaggerated Kappa to try make it look +different Mye which is equal to i k like + + align:start position:0% +different Mye which is equal to i k like + + + align:start position:0% +different Mye which is equal to i k like +this and then our electric + + align:start position:0% +this and then our electric + + + align:start position:0% +this and then our electric +field now goes as exponential to the + + align:start position:0% +field now goes as exponential to the + + + align:start position:0% +field now goes as exponential to the +minus Kappa X like this the electric + + align:start position:0% +minus Kappa X like this the electric + + + align:start position:0% +minus Kappa X like this the electric +field itself decays it does not + + align:start position:0% + + + + align:start position:0% + +oscillate what about in the case where + + align:start position:0% +oscillate what about in the case where + + + align:start position:0% +oscillate what about in the case where +optically thick + + align:start position:0% + + + + align:start position:0% + +does the wave oscillate or not do you + + align:start position:0% +does the wave oscillate or not do you + + + align:start position:0% +does the wave oscillate or not do you +just attenuate the amplitude yeah so in + + align:start position:0% +just attenuate the amplitude yeah so in + + + align:start position:0% +just attenuate the amplitude yeah so in +the cases where optically thick the + + align:start position:0% +the cases where optically thick the + + + align:start position:0% +the cases where optically thick the +amplitude just goes down so we still + + align:start position:0% +amplitude just goes down so we still + + + align:start position:0% +amplitude just goes down so we still +have a + + align:start position:0% + + + + align:start position:0% + +wave which is oscillating so e is going + + align:start position:0% +wave which is oscillating so e is going + + + align:start position:0% +wave which is oscillating so e is going +as exponential of I KX minus Omega + + align:start position:0% +as exponential of I KX minus Omega + + + align:start position:0% +as exponential of I KX minus Omega +T it's just that this envelope + + align:start position:0% + + + + align:start position:0% + +I which is proportional + + align:start position:0% +I which is proportional + + + align:start position:0% +I which is proportional +to etimes its complex conjugate not + + align:start position:0% +to etimes its complex conjugate not + + + align:start position:0% +to etimes its complex conjugate not +proportional just is e times conjugate + + align:start position:0% +proportional just is e times conjugate + + + align:start position:0% +proportional just is e times conjugate +that is dropping like exponential of + + align:start position:0% +that is dropping like exponential of + + + align:start position:0% +that is dropping like exponential of +minus to right but the wave is still + + align:start position:0% + + + + align:start position:0% + +oscillating any other differences about + + align:start position:0% + + + + align:start position:0% + +this it's a clarifying question I mean + + align:start position:0% +this it's a clarifying question I mean + + + align:start position:0% +this it's a clarifying question I mean +these cases are are actually the same + + align:start position:0% +these cases are are actually the same + + + align:start position:0% +these cases are are actually the same +right just that in one case you've + + align:start position:0% +right just that in one case you've + + + align:start position:0% +right just that in one case you've +entirely gone to an imaginary K and in + + align:start position:0% +entirely gone to an imaginary K and in + + + align:start position:0% +entirely gone to an imaginary K and in +the other case you would you in + + align:start position:0% +the other case you would you in + + + align:start position:0% +the other case you would you in +principle could have a complex day or + + align:start position:0% +principle could have a complex day or + + + align:start position:0% +principle could have a complex day or +something that actually feeds into my + + align:start position:0% +something that actually feeds into my + + + align:start position:0% +something that actually feeds into my +final point so yeah keep going with that + + align:start position:0% +final point so yeah keep going with that + + + align:start position:0% +final point so yeah keep going with that +thought I just I guess just to say one + + align:start position:0% +thought I just I guess just to say one + + + align:start position:0% +thought I just I guess just to say one +case could become the other assuming you + + align:start position:0% +case could become the other assuming you + + + align:start position:0% +case could become the other assuming you +lost all of your real part but yeah so + + align:start position:0% +lost all of your real part but yeah so + + + align:start position:0% +lost all of your real part but yeah so +people on line that the question was you + + align:start position:0% +people on line that the question was you + + + align:start position:0% +people on line that the question was you +know may actually be the same in some + + align:start position:0% +know may actually be the same in some + + + align:start position:0% +know may actually be the same in some +sense this is a slow Decay this is a + + align:start position:0% +sense this is a slow Decay this is a + + + align:start position:0% +sense this is a slow Decay this is a +very rapid Decay the difference I see + + align:start position:0% +very rapid Decay the difference I see + + + align:start position:0% +very rapid Decay the difference I see +here is that you can have this slow + + align:start position:0% +here is that you can have this slow + + + align:start position:0% +here is that you can have this slow +Decay for many different values of the + + align:start position:0% +Decay for many different values of the + + + align:start position:0% +Decay for many different values of the +optical depth this happens suddenly and + + align:start position:0% +optical depth this happens suddenly and + + + align:start position:0% +optical depth this happens suddenly and +only when we get to the critical density + + align:start position:0% +only when we get to the critical density + + + align:start position:0% +only when we get to the critical density +before that the wave knows nothing about + + align:start position:0% +before that the wave knows nothing about + + + align:start position:0% +before that the wave knows nothing about +it in reality if the density is ramping + + align:start position:0% +it in reality if the density is ramping + + + align:start position:0% +it in reality if the density is ramping +up the wavelength will get longer but + + align:start position:0% +up the wavelength will get longer but + + + align:start position:0% +up the wavelength will get longer but +the amplitude of the wave packet in our + + align:start position:0% +the amplitude of the wave packet in our + + + align:start position:0% +the amplitude of the wave packet in our +wkp approximation that we use to derive + + align:start position:0% +wkp approximation that we use to derive + + + align:start position:0% +wkp approximation that we use to derive +equations that amplitude doesn't change + + align:start position:0% +equations that amplitude doesn't change + + + align:start position:0% +equations that amplitude doesn't change +so I guess the way I summarize this in + + align:start position:0% +so I guess the way I summarize this in + + + align:start position:0% +so I guess the way I summarize this in +my notes is that this is a gradual + + align:start position:0% +my notes is that this is a gradual + + + align:start position:0% +my notes is that this is a gradual +process and this is a sudden + + align:start position:0% + + + + align:start position:0% + +process in a sense this is an overdamped + + align:start position:0% +process in a sense this is an overdamped + + + align:start position:0% +process in a sense this is an overdamped +oscillator the the the amplitude just + + align:start position:0% +oscillator the the the amplitude just + + + align:start position:0% +oscillator the the the amplitude just +drops without oscillating and this is an + + align:start position:0% +drops without oscillating and this is an + + + align:start position:0% +drops without oscillating and this is an +underdamped or maybe critically damped + + align:start position:0% +underdamped or maybe critically damped + + + align:start position:0% +underdamped or maybe critically damped +oscillator where the wave keeps + + align:start position:0% +oscillator where the wave keeps + + + align:start position:0% +oscillator where the wave keeps +oscillating but it goes down slowly + + align:start position:0% +oscillating but it goes down slowly + + + align:start position:0% +oscillating but it goes down slowly +so and you know this will happen there + + align:start position:0% +so and you know this will happen there + + + align:start position:0% +so and you know this will happen there +will always be some absorption in some + + align:start position:0% +will always be some absorption in some + + + align:start position:0% +will always be some absorption in some +plasma so you always have very gradual + + align:start position:0% +plasma so you always have very gradual + + + align:start position:0% +plasma so you always have very gradual +decrease whereas you don't actually have + + align:start position:0% +decrease whereas you don't actually have + + + align:start position:0% +decrease whereas you don't actually have +to have this happen in any plas at all + + align:start position:0% +to have this happen in any plas at all + + + align:start position:0% +to have this happen in any plas at all +there doesn't have to be a critical test + + align:start position:0% +there doesn't have to be a critical test + + + align:start position:0% +there doesn't have to be a critical test +but there will always be some finite + + align:start position:0% +but there will always be some finite + + + align:start position:0% +but there will always be some finite +capacity even if it's very very small + + align:start position:0% +capacity even if it's very very small + + + align:start position:0% +capacity even if it's very very small +anyway I don't know if that's profound + + align:start position:0% +anyway I don't know if that's profound + + + align:start position:0% +anyway I don't know if that's profound +or not I just thought it was interesting + + align:start position:0% +or not I just thought it was interesting + + + align:start position:0% +or not I just thought it was interesting +that these two phenomena look quite + + align:start position:0% +that these two phenomena look quite + + + align:start position:0% +that these two phenomena look quite +similar but they're actually very + + align:start position:0% + + + + align:start position:0% + +good okay more questions yes weird we + + align:start position:0% +good okay more questions yes weird we + + + align:start position:0% +good okay more questions yes weird we +talk a little bit not being over able to + + align:start position:0% +talk a little bit not being over able to + + + align:start position:0% +talk a little bit not being over able to +like see over the build or some + + align:start position:0% +like see over the build or some + + + align:start position:0% +like see over the build or some +reflectometry yes yeah so if you have a + + align:start position:0% +reflectometry yes yeah so if you have a + + + align:start position:0% +reflectometry yes yeah so if you have a +case where your Decay is longer than the + + align:start position:0% +case where your Decay is longer than the + + + align:start position:0% +case where your Decay is longer than the +length scale over which your critical + + align:start position:0% +length scale over which your critical + + + align:start position:0% +length scale over which your critical +deny is maintained do you get weird + + align:start position:0% +deny is maintained do you get weird + + + align:start position:0% +deny is maintained do you get weird +things where it becomes wave on the + + align:start position:0% +things where it becomes wave on the + + + align:start position:0% +things where it becomes wave on the +other side I like so the question was if + + align:start position:0% +other side I like so the question was if + + + align:start position:0% +other side I like so the question was if +you have a region where the density + + align:start position:0% +you have a region where the density + + + align:start position:0% +you have a region where the density +drops below the critical density for + + align:start position:0% +drops below the critical density for + + + align:start position:0% +drops below the critical density for +example here so any less than critical + + align:start position:0% +example here so any less than critical + + + align:start position:0% +example here so any less than critical +density what happens to wave has anyone + + align:start position:0% +density what happens to wave has anyone + + + align:start position:0% +density what happens to wave has anyone +done this experiment I did it in + + align:start position:0% +done this experiment I did it in + + + align:start position:0% +done this experiment I did it in +underground it was incredible life + + align:start position:0% + + + + align:start position:0% + +changing yeah it will start oscillating + + align:start position:0% +changing yeah it will start oscillating + + + align:start position:0% +changing yeah it will start oscillating +again yeah so you will couple an + + align:start position:0% +again yeah so you will couple an + + + align:start position:0% +again yeah so you will couple an +evanescent wave you can couple an + + align:start position:0% +evanescent wave you can couple an + + + align:start position:0% +evanescent wave you can couple an +oscillating wave through an evanescent + + align:start position:0% +oscillating wave through an evanescent + + + align:start position:0% +oscillating wave through an evanescent +Gap where the wave itself does not + + align:start position:0% +Gap where the wave itself does not + + + align:start position:0% +Gap where the wave itself does not +propagate and energy will start coming + + align:start position:0% +propagate and energy will start coming + + + align:start position:0% +propagate and energy will start coming +out the other side we did it with wax + + align:start position:0% +out the other side we did it with wax + + + align:start position:0% +out the other side we did it with wax +blocks and microwaves in undergr lb + + align:start position:0% +blocks and microwaves in undergr lb + + + align:start position:0% +blocks and microwaves in undergr lb +these big blocks of wax and a microwave + + align:start position:0% +these big blocks of wax and a microwave + + + align:start position:0% +these big blocks of wax and a microwave +generator and as you move the wax blocks + + align:start position:0% +generator and as you move the wax blocks + + + align:start position:0% +generator and as you move the wax blocks +apart you can like generate a wave with + + align:start position:0% +apart you can like generate a wave with + + + align:start position:0% +apart you can like generate a wave with +increasingly small amplitude but the + + align:start position:0% +increasingly small amplitude but the + + + align:start position:0% +increasingly small amplitude but the +wave is still there and it bridged a gap + + align:start position:0% +wave is still there and it bridged a gap + + + align:start position:0% +wave is still there and it bridged a gap +and then the remaining energy because + + align:start position:0% +and then the remaining energy because + + + align:start position:0% +and then the remaining energy because +now your wave is just oscillating on the + + align:start position:0% +now your wave is just oscillating on the + + + align:start position:0% +now your wave is just oscillating on the +other side of much smaller that + + align:start position:0% +other side of much smaller that + + + align:start position:0% +other side of much smaller that +remaining energy is reflected instead + + align:start position:0% +remaining energy is reflected instead + + + align:start position:0% +remaining energy is reflected instead +but this is this is a really cool + + align:start position:0% +but this is this is a really cool + + + align:start position:0% +but this is this is a really cool +example of electron + + align:start position:0% +example of electron + + + align:start position:0% +example of electron +yeah I assume the same thing happens in + + align:start position:0% +yeah I assume the same thing happens in + + + align:start position:0% +yeah I assume the same thing happens in +a toat or an + + align:start position:0% + + + + align:start position:0% + +neoplasm does it people who do + + align:start position:0% +neoplasm does it people who do + + + align:start position:0% +neoplasm does it people who do +waves for I in lower hybrid right okay + + align:start position:0% +waves for I in lower hybrid right okay + + + align:start position:0% +waves for I in lower hybrid right okay +so you can get it evanescently crossing + + align:start position:0% +so you can get it evanescently crossing + + + align:start position:0% +so you can get it evanescently crossing +a bit of the plasma and then coming back + + align:start position:0% +a bit of the plasma and then coming back + + + align:start position:0% +a bit of the plasma and then coming back +to life on the other side yeah that's + + align:start position:0% +to life on the other side yeah that's + + + align:start position:0% +to life on the other side yeah that's +why you want to put your laer as close + + align:start position:0% +why you want to put your laer as close + + + align:start position:0% +why you want to put your laer as close +to the as you can right obviously that + + align:start position:0% +to the as you can right obviously that + + + align:start position:0% +to the as you can right obviously that +gives you you know CL service problem + + align:start position:0% +gives you you know CL service problem + + + align:start position:0% +gives you you know CL service problem +okay just for the people online Grant is + + align:start position:0% +okay just for the people online Grant is + + + align:start position:0% +okay just for the people online Grant is +saying that you want to put your + + align:start position:0% +saying that you want to put your + + + align:start position:0% +saying that you want to put your +launcher very very close to last close + + align:start position:0% +launcher very very close to last close + + + align:start position:0% +launcher very very close to last close +block surface because otherwise it's + + align:start position:0% +block surface because otherwise it's + + + align:start position:0% +block surface because otherwise it's +evanescently decaying in free space so + + align:start position:0% +evanescently decaying in free space so + + + align:start position:0% +evanescently decaying in free space so +you want it very close to plasma where + + align:start position:0% +you want it very close to plasma where + + + align:start position:0% +you want it very close to plasma where +it's actually in oscillating mode + + align:start position:0% +it's actually in oscillating mode + + + align:start position:0% +it's actually in oscillating mode +instead okay any other questions on this + + align:start position:0% +instead okay any other questions on this + + + align:start position:0% +instead okay any other questions on this +and then we will go on to deriving + + align:start position:0% +and then we will go on to deriving + + + align:start position:0% +and then we will go on to deriving +radiation from + + align:start position:0% +radiation from + + + align:start position:0% +radiation from +recharges oh no screams none of you have + + align:start position:0% +recharges oh no screams none of you have + + + align:start position:0% +recharges oh no screams none of you have +done + + align:start position:0% + + + + align:start position:0% + +Jackson + + align:start position:0% + + + + align:start position:0% + +the good news is we're not going to do + + align:start position:0% +the good news is we're not going to do + + + align:start position:0% +the good news is we're not going to do +the P Jackson treatment of this it's + + align:start position:0% +the P Jackson treatment of this it's + + + align:start position:0% +the P Jackson treatment of this it's +extremely boring and you hopefully done + + align:start position:0% +extremely boring and you hopefully done + + + align:start position:0% +extremely boring and you hopefully done +it before and if you haven't there's no + + align:start position:0% +it before and if you haven't there's no + + + align:start position:0% +it before and if you haven't there's no +way I'm going to teach you it in a + + align:start position:0% +way I'm going to teach you it in a + + + align:start position:0% +way I'm going to teach you it in a +couple of lectures we're going to quote + + align:start position:0% +couple of lectures we're going to quote + + + align:start position:0% +couple of lectures we're going to quote +some of the main results if they look + + align:start position:0% +some of the main results if they look + + + align:start position:0% +some of the main results if they look +completely perplexing then might be + + align:start position:0% +completely perplexing then might be + + + align:start position:0% +completely perplexing then might be +worth going to have a look at something + + align:start position:0% +worth going to have a look at something + + + align:start position:0% +worth going to have a look at something +that deals with radiation from pre + + align:start position:0% +that deals with radiation from pre + + + align:start position:0% +that deals with radiation from pre +chapters but we're not going to do the + + align:start position:0% +chapters but we're not going to do the + + + align:start position:0% +chapters but we're not going to do the +whole thing if you want to see it in + + align:start position:0% +whole thing if you want to see it in + + + align:start position:0% +whole thing if you want to see it in +very rigorous detail you should look at + + align:start position:0% +very rigorous detail you should look at + + + align:start position:0% +very rigorous detail you should look at +hinson's book it really does go into + + align:start position:0% +hinson's book it really does go into + + + align:start position:0% +hinson's book it really does go into +this um with a lot of rigor but what I + + align:start position:0% +this um with a lot of rigor but what I + + + align:start position:0% +this um with a lot of rigor but what I +want to start with is I want to start + + align:start position:0% +want to start with is I want to start + + + align:start position:0% +want to start with is I want to start +with a very simple picture of why + + align:start position:0% +with a very simple picture of why + + + align:start position:0% +with a very simple picture of why +charges + + align:start position:0% +charges + + + align:start position:0% +charges +radiate and I have not been able to find + + align:start position:0% +radiate and I have not been able to find + + + align:start position:0% +radiate and I have not been able to find +this in any + + align:start position:0% +this in any + + + align:start position:0% +this in any +textbook but it was thought to me in + + align:start position:0% +textbook but it was thought to me in + + + align:start position:0% +textbook but it was thought to me in +underground and I thought it was a + + align:start position:0% +underground and I thought it was a + + + align:start position:0% +underground and I thought it was a +rather nice physical picture so I will + + align:start position:0% +rather nice physical picture so I will + + + align:start position:0% +rather nice physical picture so I will +teach it to you and it may or may not be + + align:start position:0% +teach it to you and it may or may not be + + + align:start position:0% +teach it to you and it may or may not be +helpful to + + align:start position:0% +helpful to + + + align:start position:0% +helpful to +you radiation is measured by the + + align:start position:0% +you radiation is measured by the + + + align:start position:0% +you radiation is measured by the +pointing + + align:start position:0% +pointing + + + align:start position:0% +pointing +flux the pointing flux is equal to the + + align:start position:0% +flux the pointing flux is equal to the + + + align:start position:0% +flux the pointing flux is equal to the +electric field crossed with the magnetic + + align:start position:0% +electric field crossed with the magnetic + + + align:start position:0% +electric field crossed with the magnetic +field over a factor of M or probably C + + align:start position:0% +field over a factor of M or probably C + + + align:start position:0% +field over a factor of M or probably C +if you're using CGS I don't know um the + + align:start position:0% +if you're using CGS I don't know um the + + + align:start position:0% +if you're using CGS I don't know um the +point is that radiation moves in a + + align:start position:0% +point is that radiation moves in a + + + align:start position:0% +point is that radiation moves in a +direction which is perpendicular to the + + align:start position:0% +direction which is perpendicular to the + + + align:start position:0% +direction which is perpendicular to the +electric and the magnetic fields in the + + align:start position:0% +electric and the magnetic fields in the + + + align:start position:0% +electric and the magnetic fields in the +system and we're going to use this + + align:start position:0% +system and we're going to use this + + + align:start position:0% +system and we're going to use this +simple formula and sketch a few + + align:start position:0% +simple formula and sketch a few + + + align:start position:0% +simple formula and sketch a few +different moving charges and we're going + + align:start position:0% +different moving charges and we're going + + + align:start position:0% +different moving charges and we're going +to use that to see whether those charges + + align:start position:0% +to use that to see whether those charges + + + align:start position:0% +to use that to see whether those charges +radiate or not so let us start with a + + align:start position:0% +radiate or not so let us start with a + + + align:start position:0% +radiate or not so let us start with a +very simple system an + + align:start position:0% +very simple system an + + + align:start position:0% +very simple system an +electron at + + align:start position:0% +electron at + + + align:start position:0% +electron at +rest what are the electric and magnetic + + align:start position:0% +rest what are the electric and magnetic + + + align:start position:0% +rest what are the electric and magnetic +fields in this + + align:start position:0% + + + + align:start position:0% + +system yes a radial electric field no + + align:start position:0% +system yes a radial electric field no + + + align:start position:0% +system yes a radial electric field no +there's a radial electric field like + + align:start position:0% + + + + align:start position:0% + +this this electric field drops off as + + align:start position:0% +this this electric field drops off as + + + align:start position:0% +this this electric field drops off as +one upon r s G's law in the r hat + + align:start position:0% +one upon r s G's law in the r hat + + + align:start position:0% +one upon r s G's law in the r hat +Direction the magnetic field is zero + + align:start position:0% +Direction the magnetic field is zero + + + align:start position:0% +Direction the magnetic field is zero +because there are no moving charges so + + align:start position:0% +because there are no moving charges so + + + align:start position:0% +because there are no moving charges so +there's no currents and so + + align:start position:0% +there's no currents and so + + + align:start position:0% +there's no currents and so +therefore the pointing Vector is zero + + align:start position:0% +therefore the pointing Vector is zero + + + align:start position:0% +therefore the pointing Vector is zero +our stationary charge is not R yet okay + + align:start position:0% +our stationary charge is not R yet okay + + + align:start position:0% +our stationary charge is not R yet okay +next one now we got a particle and it's + + align:start position:0% +next one now we got a particle and it's + + + align:start position:0% +next one now we got a particle and it's +traveling at a constant + + align:start position:0% +traveling at a constant + + + align:start position:0% +traveling at a constant +velocity for example it's traveling in + + align:start position:0% +velocity for example it's traveling in + + + align:start position:0% +velocity for example it's traveling in +this + + align:start position:0% +this + + + align:start position:0% +this +direction at a snapshot in + + align:start position:0% +direction at a snapshot in + + + align:start position:0% +direction at a snapshot in +time I am looking at this particle from + + align:start position:0% +time I am looking at this particle from + + + align:start position:0% +time I am looking at this particle from +my lab frame what are the electric and + + align:start position:0% +my lab frame what are the electric and + + + align:start position:0% +my lab frame what are the electric and +the magnetic fields + + align:start position:0% + + + + align:start position:0% + +here not you again we'll have someone + + align:start position:0% +here not you again we'll have someone + + + align:start position:0% +here not you again we'll have someone +else but I'm glad you + + align:start position:0% +else but I'm glad you + + + align:start position:0% +else but I'm glad you +know uh the magnetic field you can do by + + align:start position:0% +know uh the magnetic field you can do by + + + align:start position:0% +know uh the magnetic field you can do by +like the uh right hand rule so it's a + + align:start position:0% +like the uh right hand rule so it's a + + + align:start position:0% +like the uh right hand rule so it's a +moving charge + + align:start position:0% +moving charge + + + align:start position:0% +moving charge +yeah so there'll be some sort of there's + + align:start position:0% +yeah so there'll be some sort of there's + + + align:start position:0% +yeah so there'll be some sort of there's +current in this direction so there'll be + + align:start position:0% +current in this direction so there'll be + + + align:start position:0% +current in this direction so there'll be +a magnetic field surrounding it I've + + align:start position:0% +a magnetic field surrounding it I've + + + align:start position:0% +a magnetic field surrounding it I've +grown this sort of tilted kind of out of + + align:start position:0% +grown this sort of tilted kind of out of + + + align:start position:0% +grown this sort of tilted kind of out of +the page otherwise I just have to draw + + align:start position:0% +the page otherwise I just have to draw + + + align:start position:0% +the page otherwise I just have to draw +it straight up and down which would be + + align:start position:0% +it straight up and down which would be + + + align:start position:0% +it straight up and down which would be +hard to do so okay this is B Theta what + + align:start position:0% +hard to do so okay this is B Theta what + + + align:start position:0% +hard to do so okay this is B Theta what +about the electric + + align:start position:0% + + + + align:start position:0% + +Fields know + + align:start position:0% + + + + align:start position:0% + +question yes there are still the same + + align:start position:0% +question yes there are still the same + + + align:start position:0% +question yes there are still the same +electric field s RA + + align:start position:0% +electric field s RA + + + align:start position:0% +electric field s RA +in ask any question we're observing from + + align:start position:0% +in ask any question we're observing from + + + align:start position:0% +in ask any question we're observing from +close enough that able to see it's moved + + align:start position:0% +close enough that able to see it's moved + + + align:start position:0% +close enough that able to see it's moved +and all that good stuff yes yes this is + + align:start position:0% +and all that good stuff yes yes this is + + + align:start position:0% +and all that good stuff yes yes this is +this is definitely not rigorous but it + + align:start position:0% +this is definitely not rigorous but it + + + align:start position:0% +this is definitely not rigorous but it +does get the right answer so please bear + + align:start position:0% +does get the right answer so please bear + + + align:start position:0% +does get the right answer so please bear +with me even if you're + + align:start position:0% +with me even if you're + + + align:start position:0% +with me even if you're +like okay so then we've got electric + + align:start position:0% +like okay so then we've got electric + + + align:start position:0% +like okay so then we've got electric +fields which go as one upon r s r hat + + align:start position:0% +fields which go as one upon r s r hat + + + align:start position:0% +fields which go as one upon r s r hat +magnetic fields + + align:start position:0% +magnetic fields + + + align:start position:0% +magnetic fields +which are going to go as one upon + + align:start position:0% +which are going to go as one upon + + + align:start position:0% +which are going to go as one upon +R Theta hat this is assuming that we've + + align:start position:0% +R Theta hat this is assuming that we've + + + align:start position:0% +R Theta hat this is assuming that we've +sort of got this electron as a current + + align:start position:0% +sort of got this electron as a current + + + align:start position:0% +sort of got this electron as a current +carrying wire like clearly it's not a + + align:start position:0% +carrying wire like clearly it's not a + + + align:start position:0% +carrying wire like clearly it's not a +current carrying wire that's the result + + align:start position:0% +current carrying wire that's the result + + + align:start position:0% +current carrying wire that's the result +for a current carrying wire um but it's + + align:start position:0% +for a current carrying wire um but it's + + + align:start position:0% +for a current carrying wire um but it's +sort of dropping off in this kind of + + align:start position:0% +sort of dropping off in this kind of + + + align:start position:0% +sort of dropping off in this kind of +fashion and so that + + align:start position:0% +fashion and so that + + + align:start position:0% +fashion and so that +means what is + + align:start position:0% + + + + align:start position:0% + +s how does it scale and what directions + + align:start position:0% +s how does it scale and what directions + + + align:start position:0% +s how does it scale and what directions +it + + align:start position:0% +it + + + align:start position:0% +it +pointing pointing in the th direction or + + align:start position:0% +pointing pointing in the th direction or + + + align:start position:0% +pointing pointing in the th direction or +whatever depends on your units yeah I + + align:start position:0% +whatever depends on your units yeah I + + + align:start position:0% +whatever depends on your units yeah I +system's a bit screwy here um let's say + + align:start position:0% +system's a bit screwy here um let's say + + + align:start position:0% +system's a bit screwy here um let's say +I'm using cylindrical coordinates where + + align:start position:0% +I'm using cylindrical coordinates where + + + align:start position:0% +I'm using cylindrical coordinates where +I've got Z Direction here a radial + + align:start position:0% +I've got Z Direction here a radial + + + align:start position:0% +I've got Z Direction here a radial +Direction here and I've got some Theta + + align:start position:0% +Direction here and I've got some Theta + + + align:start position:0% +Direction here and I've got some Theta +angle like + + align:start position:0% +angle like + + + align:start position:0% +angle like +this I know that doesn't make sense with + + align:start position:0% +this I know that doesn't make sense with + + + align:start position:0% +this I know that doesn't make sense with +the definition of r that we had earlier + + align:start position:0% +the definition of r that we had earlier + + + align:start position:0% +the definition of r that we had earlier +but + + align:start position:0% +but + + + align:start position:0% +but +again yeah maybe + + align:start position:0% + + + + align:start position:0% + +yeah I'm going to drop + + align:start position:0% +yeah I'm going to drop + + + align:start position:0% +yeah I'm going to drop +the treat myself um and what directions + + align:start position:0% +the treat myself um and what directions + + + align:start position:0% +the treat myself um and what directions +it pointed in the Z Direction + + align:start position:0% + + + + align:start position:0% + +yes what is this pointing flux + + align:start position:0% + + + + align:start position:0% + +doing pointing flux is the transport of + + align:start position:0% +doing pointing flux is the transport of + + + align:start position:0% +doing pointing flux is the transport of +electromagnetic energy what's it doing + + align:start position:0% +electromagnetic energy what's it doing + + + align:start position:0% +electromagnetic energy what's it doing +why is it pointing in the Z direction is + + align:start position:0% +why is it pointing in the Z direction is + + + align:start position:0% +why is it pointing in the Z direction is +it + + align:start position:0% +it + + + align:start position:0% +it +radiating is following the particle this + + align:start position:0% +radiating is following the particle this + + + align:start position:0% +radiating is following the particle this +pointing flux is simply moving the + + align:start position:0% +pointing flux is simply moving the + + + align:start position:0% +pointing flux is simply moving the +electric and magnetic fields that the + + align:start position:0% +electric and magnetic fields that the + + + align:start position:0% +electric and magnetic fields that the +particle has with the particle okay and + + align:start position:0% +particle has with the particle okay and + + + align:start position:0% +particle has with the particle okay and +it drops off as one / R Cub it drops off + + align:start position:0% +it drops off as one / R Cub it drops off + + + align:start position:0% +it drops off as one / R Cub it drops off +very very quickly away from the particle + + align:start position:0% +very very quickly away from the particle + + + align:start position:0% +very very quickly away from the particle +right if I draw a surface with surface + + align:start position:0% +right if I draw a surface with surface + + + align:start position:0% +right if I draw a surface with surface +area r s around it and I ask how much + + align:start position:0% +area r s around it and I ask how much + + + align:start position:0% +area r s around it and I ask how much +total power do I have going through that + + align:start position:0% +total power do I have going through that + + + align:start position:0% +total power do I have going through that +surface that amount of total power will + + align:start position:0% +surface that amount of total power will + + + align:start position:0% +surface that amount of total power will +drop off as I make my service bigger + + align:start position:0% +drop off as I make my service bigger + + + align:start position:0% +drop off as I make my service bigger +this is not a propagating wave you can't + + align:start position:0% +this is not a propagating wave you can't + + + align:start position:0% +this is not a propagating wave you can't +observe this I mean again you need to be + + align:start position:0% +observe this I mean again you need to be + + + align:start position:0% +observe this I mean again you need to be +close enough to see what these Electric + + align:start position:0% +close enough to see what these Electric + + + align:start position:0% +close enough to see what these Electric +magnetic fields but this is not a + + align:start position:0% +magnetic fields but this is not a + + + align:start position:0% +magnetic fields but this is not a +radiation you can see from far + + align:start position:0% +radiation you can see from far + + + align:start position:0% +radiation you can see from far +away + + align:start position:0% +away + + + align:start position:0% +away +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +this + + align:start position:0% + + + + align:start position:0% + +moves + + align:start position:0% +moves + + + align:start position:0% +moves +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +energy with the electron like that this + + align:start position:0% +energy with the electron like that this + + + align:start position:0% +energy with the electron like that this +is the point of it I can add sorry now + + align:start position:0% +is the point of it I can add sorry now + + + align:start position:0% +is the point of it I can add sorry now +we decided it's in the Z Direction + + align:start position:0% + + + + align:start position:0% + +okay now + + align:start position:0% +okay now + + + align:start position:0% +okay now +finally we're going to look at a system + + align:start position:0% +finally we're going to look at a system + + + align:start position:0% +finally we're going to look at a system +where the velocity is not + + align:start position:0% +where the velocity is not + + + align:start position:0% +where the velocity is not +constant and I'm going to look at a very + + align:start position:0% +constant and I'm going to look at a very + + + align:start position:0% +constant and I'm going to look at a very +very specific velocity profile here and + + align:start position:0% +very specific velocity profile here and + + + align:start position:0% +very specific velocity profile here and +you'll see why I've chosen this in a + + align:start position:0% +you'll see why I've chosen this in a + + + align:start position:0% +you'll see why I've chosen this in a +moment this is a profile in which the + + align:start position:0% +moment this is a profile in which the + + + align:start position:0% +moment this is a profile in which the +velocity of our particle in this sort of + + align:start position:0% +velocity of our particle in this sort of + + + align:start position:0% +velocity of our particle in this sort of +Z direction is initially at some value + + align:start position:0% +Z direction is initially at some value + + + align:start position:0% +Z direction is initially at some value +and then suddenly instantaneously drops + + align:start position:0% +and then suddenly instantaneously drops + + + align:start position:0% +and then suddenly instantaneously drops +to + + align:start position:0% +to + + + align:start position:0% +to +zero a function of + + align:start position:0% +zero a function of + + + align:start position:0% +zero a function of +time which means + + align:start position:0% + + + + align:start position:0% + +that the x coordinate is going to go up + + align:start position:0% +that the x coordinate is going to go up + + + align:start position:0% +that the x coordinate is going to go up +and then flatten on the particle will + + align:start position:0% +and then flatten on the particle will + + + align:start position:0% +and then flatten on the particle will +then be at rest and we'll Define this to + + align:start position:0% +then be at rest and we'll Define this to + + + align:start position:0% +then be at rest and we'll Define this to +be b equals zero + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +am I going to get + + align:start position:0% +am I going to get + + + align:start position:0% +am I going to get +this change something just before the + + align:start position:0% +this change something just before the + + + align:start position:0% +this change something just before the +elction to make it clearer now I'm not + + align:start position:0% +elction to make it clearer now I'm not + + + align:start position:0% +elction to make it clearer now I'm not +sure it's consistent give me + + align:start position:0% + + + + align:start position:0% + +a doing it the other way around let's + + align:start position:0% +a doing it the other way around let's + + + align:start position:0% +a doing it the other way around let's +see the particle is initially at rest + + align:start position:0% +see the particle is initially at rest + + + align:start position:0% +see the particle is initially at rest +and then it suddenly accelerates the + + align:start position:0% +and then it suddenly accelerates the + + + align:start position:0% +and then it suddenly accelerates the +some velocity I think this will make it + + align:start position:0% + + + + align:start position:0% + +work + + align:start position:0% + + + + align:start position:0% + +so the particle is initially at rest + + align:start position:0% +so the particle is initially at rest + + + align:start position:0% +so the particle is initially at rest +let's say it's at rest here and then all + + align:start position:0% +let's say it's at rest here and then all + + + align:start position:0% +let's say it's at rest here and then all +of a sudden it's over moving in this + + align:start position:0% +of a sudden it's over moving in this + + + align:start position:0% +of a sudden it's over moving in this +direction like this now + + align:start position:0% +direction like this now + + + align:start position:0% +direction like this now +information about the electric and + + align:start position:0% +information about the electric and + + + align:start position:0% +information about the electric and +magnetic fields of this particle can + + align:start position:0% +magnetic fields of this particle can + + + align:start position:0% +magnetic fields of this particle can +only propagate at the speed of light and + + align:start position:0% +only propagate at the speed of light and + + + align:start position:0% +only propagate at the speed of light and +so that means if I an observer some + + align:start position:0% +so that means if I an observer some + + + align:start position:0% +so that means if I an observer some +distance away + + align:start position:0% +distance away + + + align:start position:0% +distance away +and let's say that that distance + + align:start position:0% + + + + align:start position:0% + +is this circle like that the information + + align:start position:0% +is this circle like that the information + + + align:start position:0% +is this circle like that the information +I have about the electrical magnetic + + align:start position:0% +I have about the electrical magnetic + + + align:start position:0% +I have about the electrical magnetic +fields is the same information I had oh + + align:start position:0% +fields is the same information I had oh + + + align:start position:0% +fields is the same information I had oh +from my point of view the particle is + + align:start position:0% +from my point of view the particle is + + + align:start position:0% +from my point of view the particle is +still at rest which means that outside + + align:start position:0% +still at rest which means that outside + + + align:start position:0% +still at rest which means that outside +of this + + align:start position:0% +of this + + + align:start position:0% +of this +circle all I can say is that the + + align:start position:0% +circle all I can say is that the + + + align:start position:0% +circle all I can say is that the +electric fields are + + align:start position:0% +electric fields are + + + align:start position:0% +electric fields are +pointing inwards here inside the surface + + align:start position:0% +pointing inwards here inside the surface + + + align:start position:0% +pointing inwards here inside the surface +I now know that the electric fields are + + align:start position:0% +I now know that the electric fields are + + + align:start position:0% +I now know that the electric fields are +doing something quite different they're + + align:start position:0% +doing something quite different they're + + + align:start position:0% +doing something quite different they're +now + + align:start position:0% +now + + + align:start position:0% +now +looking like + + align:start position:0% +looking like + + + align:start position:0% +looking like +this and that we have some sort of + + align:start position:0% +this and that we have some sort of + + + align:start position:0% +this and that we have some sort of +magnetic field like + + align:start position:0% +magnetic field like + + + align:start position:0% +magnetic field like +this now the electric field lines cannot + + align:start position:0% +this now the electric field lines cannot + + + align:start position:0% +this now the electric field lines cannot +be broken these electric field lines + + align:start position:0% +be broken these electric field lines + + + align:start position:0% +be broken these electric field lines +therefore in this sort of very + + align:start position:0% +therefore in this sort of very + + + align:start position:0% +therefore in this sort of very +fictitious scenario have to be joined up + + align:start position:0% +fictitious scenario have to be joined up + + + align:start position:0% +fictitious scenario have to be joined up +in this way so I'm also going to draw + + align:start position:0% +in this way so I'm also going to draw + + + align:start position:0% +in this way so I'm also going to draw +some electric field lines like that + + align:start position:0% +some electric field lines like that + + + align:start position:0% +some electric field lines like that +electric field lines like that and these + + align:start position:0% +electric field lines like that and these + + + align:start position:0% +electric field lines like that and these +ones for the + + align:start position:0% + + + + align:start position:0% + +outside like this and now again on the + + align:start position:0% +outside like this and now again on the + + + align:start position:0% +outside like this and now again on the +inside I've got some magnetic field + + align:start position:0% + + + + align:start position:0% + +lines which are still in this PO loidal + + align:start position:0% + + + + align:start position:0% + +Direction + + align:start position:0% +Direction + + + align:start position:0% +Direction +so what's happening now + + align:start position:0% +so what's happening now + + + align:start position:0% +so what's happening now +to our pointing flux to our electric + + align:start position:0% +to our pointing flux to our electric + + + align:start position:0% +to our pointing flux to our electric +field to our magnetic field let's just + + align:start position:0% +field to our magnetic field let's just + + + align:start position:0% +field to our magnetic field let's just +do the magnetic field and say that at + + align:start position:0% +do the magnetic field and say that at + + + align:start position:0% +do the magnetic field and say that at +this interface here + + align:start position:0% +this interface here + + + align:start position:0% +this interface here +so + + align:start position:0% +so + + + align:start position:0% +so +at this interface we still have a + + align:start position:0% +at this interface we still have a + + + align:start position:0% +at this interface we still have a +magnetic field which goes one upon R + + align:start position:0% +magnetic field which goes one upon R + + + align:start position:0% +magnetic field which goes one upon R +Theta hat we got an electric + + align:start position:0% +Theta hat we got an electric + + + align:start position:0% +Theta hat we got an electric +field ah okay I think this is the bit + + align:start position:0% +field ah okay I think this is the bit + + + align:start position:0% +field ah okay I think this is the bit +where I just have to tell you to believe + + align:start position:0% +where I just have to tell you to believe + + + align:start position:0% +where I just have to tell you to believe +me + + align:start position:0% +me + + + align:start position:0% +me +um remember I can prove this straight + + align:start position:0% + + + + align:start position:0% + +away this electric field turns out to + + align:start position:0% +away this electric field turns out to + + + align:start position:0% +away this electric field turns out to +have a scaling which goes as one upon R + + align:start position:0% +have a scaling which goes as one upon R + + + align:start position:0% +have a scaling which goes as one upon R +I can't remember where that comes from + + align:start position:0% +I can't remember where that comes from + + + align:start position:0% +I can't remember where that comes from +um not one upon R squ but it's very + + align:start position:0% +um not one upon R squ but it's very + + + align:start position:0% +um not one upon R squ but it's very +important for the conclusion and also + + align:start position:0% +important for the conclusion and also + + + align:start position:0% +important for the conclusion and also +here if we uh think about this direction + + align:start position:0% +here if we uh think about this direction + + + align:start position:0% +here if we uh think about this direction +uh we're going to have something which + + align:start position:0% +uh we're going to have something which + + + align:start position:0% +uh we're going to have something which +is tangential to this Theta Direction so + + align:start position:0% +is tangential to this Theta Direction so + + + align:start position:0% +is tangential to this Theta Direction so +I'm going to call it some sort of like + + align:start position:0% +I'm going to call it some sort of like + + + align:start position:0% +I'm going to call it some sort of like +type coordinate where I'm sort of subtly + + align:start position:0% +type coordinate where I'm sort of subtly + + + align:start position:0% +type coordinate where I'm sort of subtly +switching into uh a sperical coordinate + + align:start position:0% +switching into uh a sperical coordinate + + + align:start position:0% +switching into uh a sperical coordinate +system and all of this together means + + align:start position:0% +system and all of this together means + + + align:start position:0% +system and all of this together means +that our pointing Vector now goes as one + + align:start position:0% +that our pointing Vector now goes as one + + + align:start position:0% +that our pointing Vector now goes as one +upon R 2 + + align:start position:0% +upon R 2 + + + align:start position:0% +upon R 2 +and it has a direction our hat and this + + align:start position:0% +and it has a direction our hat and this + + + align:start position:0% +and it has a direction our hat and this +means that finally we've got a system + + align:start position:0% +means that finally we've got a system + + + align:start position:0% +means that finally we've got a system +which is radiating so this is moving + + align:start position:0% +which is radiating so this is moving + + + align:start position:0% +which is radiating so this is moving +radiation radially + + align:start position:0% +radiation radially + + + align:start position:0% +radiation radially +outwards in every direction and this is + + align:start position:0% +outwards in every direction and this is + + + align:start position:0% +outwards in every direction and this is +the result that you probably remember is + + align:start position:0% +the result that you probably remember is + + + align:start position:0% +the result that you probably remember is +that charge particles accelerated charge + + align:start position:0% +that charge particles accelerated charge + + + align:start position:0% +that charge particles accelerated charge +particles + + align:start position:0% + + + + align:start position:0% + +Rue these this pointing Vector is not + + align:start position:0% +Rue these this pointing Vector is not + + + align:start position:0% +Rue these this pointing Vector is not +simply shuffling the energy along with + + align:start position:0% +simply shuffling the energy along with + + + align:start position:0% +simply shuffling the energy along with +the particle it's actually taking energy + + align:start position:0% +the particle it's actually taking energy + + + align:start position:0% +the particle it's actually taking energy +from the particle and put it into + + align:start position:0% +from the particle and put it into + + + align:start position:0% +from the particle and put it into +electromagnetic W and like I said be + + align:start position:0% +electromagnetic W and like I said be + + + align:start position:0% +electromagnetic W and like I said be +much more convincing if I can remember + + align:start position:0% +much more convincing if I can remember + + + align:start position:0% +much more convincing if I can remember +the argument this fact and I decided not + + align:start position:0% +the argument this fact and I decided not + + + align:start position:0% +the argument this fact and I decided not +to write it down in my notes so I can't + + align:start position:0% +to write it down in my notes so I can't + + + align:start position:0% +to write it down in my notes so I can't +remember it um but it's clearly a very + + align:start position:0% +remember it um but it's clearly a very + + + align:start position:0% +remember it um but it's clearly a very +different circumstance than we want we + + align:start position:0% +different circumstance than we want we + + + align:start position:0% +different circumstance than we want we +had here the reason we've derived this + + align:start position:0% +had here the reason we've derived this + + + align:start position:0% +had here the reason we've derived this +in this very handwavy way is I'm about + + align:start position:0% +in this very handwavy way is I'm about + + + align:start position:0% +in this very handwavy way is I'm about +to write down the actual correct + + align:start position:0% +to write down the actual correct + + + align:start position:0% +to write down the actual correct +equation and you'll see that it has + + align:start position:0% +equation and you'll see that it has + + + align:start position:0% +equation and you'll see that it has +almost no intuition involved in it + + align:start position:0% +almost no intuition involved in it + + + align:start position:0% +almost no intuition involved in it +whatsoever whereas I like to think that + + align:start position:0% +whatsoever whereas I like to think that + + + align:start position:0% +whatsoever whereas I like to think that +this gives you a little bit of intuition + + align:start position:0% +this gives you a little bit of intuition + + + align:start position:0% +this gives you a little bit of intuition +about what's going on and why moving + + align:start position:0% +about what's going on and why moving + + + align:start position:0% +about what's going on and why moving +charges r but + + align:start position:0% + + + + align:start position:0% + +questions yeah so in this situation + + align:start position:0% +questions yeah so in this situation + + + align:start position:0% +questions yeah so in this situation +you've drawn in your third situation the + + align:start position:0% +you've drawn in your third situation the + + + align:start position:0% +you've drawn in your third situation the +non the sort of light cone of the + + align:start position:0% +non the sort of light cone of the + + + align:start position:0% +non the sort of light cone of the +particle as it begins to move that's + + align:start position:0% +particle as it begins to move that's + + + align:start position:0% +particle as it begins to move that's +where the energy is located yeah so at + + align:start position:0% +where the energy is located yeah so at + + + align:start position:0% +where the energy is located yeah so at +this distance here this is where an + + align:start position:0% +this distance here this is where an + + + align:start position:0% +this distance here this is where an +observer outside of this would still + + align:start position:0% +observer outside of this would still + + + align:start position:0% +observer outside of this would still +believe the particle is located + + align:start position:0% +believe the particle is located + + + align:start position:0% +believe the particle is located +here inside this light cone The Observer + + align:start position:0% +here inside this light cone The Observer + + + align:start position:0% +here inside this light cone The Observer +can see that the particle has moved of + + align:start position:0% +can see that the particle has moved of + + + align:start position:0% +can see that the particle has moved of +course the particle is actually going to + + align:start position:0% +course the particle is actually going to + + + align:start position:0% +course the particle is actually going to +be moving in several + + align:start position:0% +be moving in several + + + align:start position:0% +be moving in several +discret like the I've drawn these + + align:start position:0% +discret like the I've drawn these + + + align:start position:0% +discret like the I've drawn these +electric field lines as straight they + + align:start position:0% +electric field lines as straight they + + + align:start position:0% +electric field lines as straight they +should actually be curved inside here + + align:start position:0% +should actually be curved inside here + + + align:start position:0% +should actually be curved inside here +I've just drawn them as straight from + + align:start position:0% +I've just drawn them as straight from + + + align:start position:0% +I've just drawn them as straight from +the like the current position of the + + align:start position:0% +the like the current position of the + + + align:start position:0% +the like the current position of the +particle at this + + align:start position:0% +particle at this + + + align:start position:0% +particle at this +point and so there must be a tangential + + align:start position:0% +point and so there must be a tangential + + + align:start position:0% +point and so there must be a tangential +discontinuity of the electric field at + + align:start position:0% +discontinuity of the electric field at + + + align:start position:0% +discontinuity of the electric field at +this surface to go from one sort of + + align:start position:0% +this surface to go from one sort of + + + align:start position:0% +this surface to go from one sort of +radial Vector pointing at one point to a + + align:start position:0% +radial Vector pointing at one point to a + + + align:start position:0% +radial Vector pointing at one point to a +new radial Vector pointing at a new + + align:start position:0% +new radial Vector pointing at a new + + + align:start position:0% +new radial Vector pointing at a new +point and it's that tangential + + align:start position:0% +point and it's that tangential + + + align:start position:0% +point and it's that tangential +discontinuity which generates this + + align:start position:0% +discontinuity which generates this + + + align:start position:0% +discontinuity which generates this +magnetic this electric field + + align:start position:0% +magnetic this electric field + + + align:start position:0% +magnetic this electric field +perpendicular to the magnetic field that + + align:start position:0% +perpendicular to the magnetic field that + + + align:start position:0% +perpendicular to the magnetic field that +gives as you know e cross B pointing + + align:start position:0% +gives as you know e cross B pointing + + + align:start position:0% +gives as you know e cross B pointing +vector and that goes radi and so for the + + align:start position:0% +vector and that goes radi and so for the + + + align:start position:0% +vector and that goes radi and so for the +situation where we have basically a step + + align:start position:0% +situation where we have basically a step + + + align:start position:0% +situation where we have basically a step +function in the velocity the energy is + + align:start position:0% +function in the velocity the energy is + + + align:start position:0% +function in the velocity the energy is +like infinitely localized to the Shell + + align:start position:0% +like infinitely localized to the Shell + + + align:start position:0% +like infinitely localized to the Shell +yeah in this case it's only the particle + + align:start position:0% +yeah in this case it's only the particle + + + align:start position:0% +yeah in this case it's only the particle +is only accelerating at this time right + + align:start position:0% +is only accelerating at this time right + + + align:start position:0% +is only accelerating at this time right +the acceleration just looks + + align:start position:0% +the acceleration just looks + + + align:start position:0% +the acceleration just looks +like a Delta function right and so + + align:start position:0% +like a Delta function right and so + + + align:start position:0% +like a Delta function right and so +therefore there's only radiation here + + align:start position:0% +therefore there's only radiation here + + + align:start position:0% +therefore there's only radiation here +propagating outwards as a ccle wave and + + align:start position:0% +propagating outwards as a ccle wave and + + + align:start position:0% +propagating outwards as a ccle wave and +then from then onwards the particle is + + align:start position:0% +then from then onwards the particle is + + + align:start position:0% +then from then onwards the particle is +just in this situation again where it's + + align:start position:0% +just in this situation again where it's + + + align:start position:0% +just in this situation again where it's +shuffling its Fields long so this is + + align:start position:0% + + + + align:start position:0% + +acceleration uh yeah so does that mean + + align:start position:0% +acceleration uh yeah so does that mean + + + align:start position:0% +acceleration uh yeah so does that mean +like if you have some like somehow the + + align:start position:0% +like if you have some like somehow the + + + align:start position:0% +like if you have some like somehow the +spatial distribution of energy is a + + align:start position:0% +spatial distribution of energy is a + + + align:start position:0% +spatial distribution of energy is a +function of your acceleration absolutely + + align:start position:0% +function of your acceleration absolutely + + + align:start position:0% +function of your acceleration absolutely +and we will see that in the like long + + align:start position:0% +and we will see that in the like long + + + align:start position:0% +and we will see that in the like long +complicated form in a moment yes you can + + align:start position:0% +complicated form in a moment yes you can + + + align:start position:0% +complicated form in a moment yes you can +do this stuff rigorously as well yeah uh + + align:start position:0% +do this stuff rigorously as well yeah uh + + + align:start position:0% +do this stuff rigorously as well yeah uh +any other questions yeah just my vague + + align:start position:0% +any other questions yeah just my vague + + + align:start position:0% +any other questions yeah just my vague +memory of how the one over our thing up + + align:start position:0% +memory of how the one over our thing up + + + align:start position:0% +memory of how the one over our thing up +is because + + align:start position:0% +is because + + + align:start position:0% +is because +you're I think it's like to have your + + align:start position:0% +you're I think it's like to have your + + + align:start position:0% +you're I think it's like to have your +voltage make some big amount of sense + + align:start position:0% +voltage make some big amount of sense + + + align:start position:0% +voltage make some big amount of sense +you have to integrate along that like + + align:start position:0% +you have to integrate along that like + + + align:start position:0% +you have to integrate along that like +path like that it's getting extended + + align:start position:0% +path like that it's getting extended + + + align:start position:0% +path like that it's getting extended +across okay so there's a suggestion this + + align:start position:0% +across okay so there's a suggestion this + + + align:start position:0% +across okay so there's a suggestion this +one over R comes from trying to keep the + + align:start position:0% +one over R comes from trying to keep the + + + align:start position:0% +one over R comes from trying to keep the +voltage + + align:start position:0% +voltage + + + align:start position:0% +voltage +to a reasonable value and your + + align:start position:0% +to a reasonable value and your + + + align:start position:0% +to a reasonable value and your +integration a path yeah there's some + + align:start position:0% +integration a path yeah there's some + + + align:start position:0% +integration a path yeah there's some +have you seen this before then yeah okay + + align:start position:0% +have you seen this before then yeah okay + + + align:start position:0% +have you seen this before then yeah okay +good I'm glad I'm not just + + align:start position:0% +good I'm glad I'm not just + + + align:start position:0% +good I'm glad I'm not just +crazy I didn't come up with this I saw + + align:start position:0% +crazy I didn't come up with this I saw + + + align:start position:0% +crazy I didn't come up with this I saw +underground and I was trying to + + align:start position:0% +underground and I was trying to + + + align:start position:0% +underground and I was trying to +reconstruct it so yeah okay any other + + align:start position:0% +reconstruct it so yeah okay any other + + + align:start position:0% +reconstruct it so yeah okay any other +questions before we move + + align:start position:0% +questions before we move + + + align:start position:0% +questions before we move +on any questions + + align:start position:0% +on any questions + + + align:start position:0% +on any questions +online I see Matt's hand yeah yeah um + + align:start position:0% +online I see Matt's hand yeah yeah um + + + align:start position:0% +online I see Matt's hand yeah yeah um +maybe you said this but I just want to + + align:start position:0% +maybe you said this but I just want to + + + align:start position:0% +maybe you said this but I just want to +make sure the pointing flux Direction in + + align:start position:0% +make sure the pointing flux Direction in + + + align:start position:0% +make sure the pointing flux Direction in +the second picture um yeah that um + + align:start position:0% +the second picture um yeah that um + + + align:start position:0% +the second picture um yeah that um +that's only valid in the plane + + align:start position:0% +that's only valid in the plane + + + align:start position:0% +that's only valid in the plane +perpendicular to the motion of the + + align:start position:0% +perpendicular to the motion of the + + + align:start position:0% +perpendicular to the motion of the +particle right because the electric + + align:start position:0% +particle right because the electric + + + align:start position:0% +particle right because the electric +field direction would be row not R like + + align:start position:0% +field direction would be row not R like + + + align:start position:0% +field direction would be row not R like +like it would have it would be in like + + align:start position:0% +like it would have it would be in like + + + align:start position:0% +like it would have it would be in like +cylindrical coordinates right I was + + align:start position:0% +cylindrical coordinates right I was + + + align:start position:0% +cylindrical coordinates right I was +saying that the fact that I Tred decid + + align:start position:0% +saying that the fact that I Tred decid + + + align:start position:0% +saying that the fact that I Tred decid +to use cylindrical coordinates here is + + align:start position:0% +to use cylindrical coordinates here is + + + align:start position:0% +to use cylindrical coordinates here is +not actually very useful because the + + align:start position:0% +not actually very useful because the + + + align:start position:0% +not actually very useful because the +electric field isn't just in that + + align:start position:0% +electric field isn't just in that + + + align:start position:0% +electric field isn't just in that +direction or in this direction it's in + + align:start position:0% +direction or in this direction it's in + + + align:start position:0% +direction or in this direction it's in +it is in Direction it's just the only + + align:start position:0% +it is in Direction it's just the only + + + align:start position:0% +it is in Direction it's just the only +place where + + align:start position:0% +place where + + + align:start position:0% +place where +e cross B is significant is really in in + + align:start position:0% +e cross B is significant is really in in + + + align:start position:0% +e cross B is significant is really in in +this plane here okay sure after the LI + + align:start position:0% +this plane here okay sure after the LI + + + align:start position:0% +this plane here okay sure after the LI +in and it will drop off it will you know + + align:start position:0% +in and it will drop off it will you know + + + align:start position:0% +in and it will drop off it will you know +if you go back to this point here e + + align:start position:0% +if you go back to this point here e + + + align:start position:0% +if you go back to this point here e +cross B because they're not very well + + align:start position:0% +cross B because they're not very well + + + align:start position:0% +cross B because they're not very well +anti-aligned it will drop off and so you + + align:start position:0% +anti-aligned it will drop off and so you + + + align:start position:0% +anti-aligned it will drop off and so you +sort of have a ring moving the uh the + + align:start position:0% +sort of have a ring moving the uh the + + + align:start position:0% +sort of have a ring moving the uh the +electric fields and magnetic fields with + + align:start position:0% +electric fields and magnetic fields with + + + align:start position:0% +electric fields and magnetic fields with +the particle yeah yeah that makes sense + + align:start position:0% +the particle yeah yeah that makes sense + + + align:start position:0% +the particle yeah yeah that makes sense +okay thanks okay any other + + align:start position:0% +okay thanks okay any other + + + align:start position:0% +okay thanks okay any other +questions okay let's see + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% + + + + align:start position:0% + +so if you do this + + align:start position:0% +so if you do this + + + align:start position:0% +so if you do this +properly you get out an + + align:start position:0% +properly you get out an + + + align:start position:0% +properly you get out an +equation for the + + align:start position:0% + + + + align:start position:0% + +radiation from a + + align:start position:0% +radiation from a + + + align:start position:0% +radiation from a +single + + align:start position:0% + + + + align:start position:0% + +moving + + align:start position:0% + + + + align:start position:0% + +charge like I said if you uh haven't + + align:start position:0% +charge like I said if you uh haven't + + + align:start position:0% +charge like I said if you uh haven't +seen this or can't remember how to do + + align:start position:0% +seen this or can't remember how to do + + + align:start position:0% +seen this or can't remember how to do +this I recommend you go take a look at + + align:start position:0% +this I recommend you go take a look at + + + align:start position:0% +this I recommend you go take a look at +Jackson or some other sufficiently + + align:start position:0% +Jackson or some other sufficiently + + + align:start position:0% +Jackson or some other sufficiently +Advanced inm + + align:start position:0% +Advanced inm + + + align:start position:0% +Advanced inm +text and this equation is the electric + + align:start position:0% +text and this equation is the electric + + + align:start position:0% +text and this equation is the electric +field seen by The Observer who is some + + align:start position:0% +field seen by The Observer who is some + + + align:start position:0% +field seen by The Observer who is some +distance away from the charge and this + + align:start position:0% +distance away from the charge and this + + + align:start position:0% +distance away from the charge and this +electric + + align:start position:0% +electric + + + align:start position:0% +electric +field has got the standard Q over 4 Pi + + align:start position:0% +field has got the standard Q over 4 Pi + + + align:start position:0% +field has got the standard Q over 4 Pi +atlon n that we know and love from ga's + + align:start position:0% +atlon n that we know and love from ga's + + + align:start position:0% +atlon n that we know and love from ga's +law and then it has two terms + + align:start position:0% +law and then it has two terms + + + align:start position:0% +law and then it has two terms +corresponding to radiation which we call + + align:start position:0% +corresponding to radiation which we call + + + align:start position:0% +corresponding to radiation which we call +the near field and the far field so the + + align:start position:0% +the near field and the far field so the + + + align:start position:0% +the near field and the far field so the +first term which is part the near field + + align:start position:0% +first term which is part the near field + + + align:start position:0% +first term which is part the near field +has a one over K squ this K is not the + + align:start position:0% +has a one over K squ this K is not the + + + align:start position:0% +has a one over K squ this K is not the +normal K that we've been using before at + + align:start position:0% +normal K that we've been using before at + + + align:start position:0% +normal K that we've been using before at +find the moment and I've just realized + + align:start position:0% +find the moment and I've just realized + + + align:start position:0% +find the moment and I've just realized +this + + align:start position:0% +this + + + align:start position:0% +this +CU K + + align:start position:0% +CU K + + + align:start position:0% +CU K +cubed R 2 then you have a term that + + align:start position:0% +cubed R 2 then you have a term that + + + align:start position:0% +cubed R 2 then you have a term that +looks like R hat minus the particle + + align:start position:0% +looks like R hat minus the particle + + + align:start position:0% +looks like R hat minus the particle +velocity on + + align:start position:0% +velocity on + + + align:start position:0% +velocity on +c one minus the particle velocity squar + + align:start position:0% +c one minus the particle velocity squar + + + align:start position:0% +c one minus the particle velocity squar +on c^2 we're going to see lots of + + align:start position:0% +on c^2 we're going to see lots of + + + align:start position:0% +on c^2 we're going to see lots of +velocities showing up normalized to C + + align:start position:0% +velocities showing up normalized to C + + + align:start position:0% +velocities showing up normalized to C +because obviously the speed of light is + + align:start position:0% +because obviously the speed of light is + + + align:start position:0% +because obviously the speed of light is +pretty important for this sort of stuff + + align:start position:0% +pretty important for this sort of stuff + + + align:start position:0% +pretty important for this sort of stuff +here I defined two new terms this K + + align:start position:0% +here I defined two new terms this K + + + align:start position:0% +here I defined two new terms this K +takes account of the fact that we're + + align:start position:0% +takes account of the fact that we're + + + align:start position:0% +takes account of the fact that we're +looking at the particle at some time + + align:start position:0% +looking at the particle at some time + + + align:start position:0% +looking at the particle at some time +we're sort of looking at the particle + + align:start position:0% +we're sort of looking at the particle + + + align:start position:0% +we're sort of looking at the particle +and we're seeing where that particle is + + align:start position:0% +and we're seeing where that particle is + + + align:start position:0% +and we're seeing where that particle is +but the particle has already moved so + + align:start position:0% +but the particle has already moved so + + + align:start position:0% +but the particle has already moved so +this is helping us with our + + align:start position:0% +this is helping us with our + + + align:start position:0% +this is helping us with our +time which is looking at the the earlier + + align:start position:0% +time which is looking at the the earlier + + + align:start position:0% +time which is looking at the the earlier +time that we're at so this K is defined + + align:start position:0% +time that we're at so this K is defined + + + align:start position:0% +time that we're at so this K is defined +as 1 + + align:start position:0% +as 1 + + + align:start position:0% +as 1 +minus r dot + + align:start position:0% +minus r dot + + + align:start position:0% +minus r dot +V upon r c and I haven't defined R + + align:start position:0% +V upon r c and I haven't defined R + + + align:start position:0% +V upon r c and I haven't defined R +either so I should do + + align:start position:0% +either so I should do + + + align:start position:0% +either so I should do +that this R is a vector that is + + align:start position:0% +that this R is a vector that is + + + align:start position:0% +that this R is a vector that is +effectively the vector that joins The + + align:start position:0% +effectively the vector that joins The + + + align:start position:0% +effectively the vector that joins The +Observer to the particle so this is Def + + align:start position:0% +Observer to the particle so this is Def + + + align:start position:0% +Observer to the particle so this is Def +find as the position of the Observer + + align:start position:0% +find as the position of the Observer + + + align:start position:0% +find as the position of the Observer +minus the position of the particle at + + align:start position:0% +minus the position of the particle at + + + align:start position:0% +minus the position of the particle at +time T So if I draw a little diagram + + align:start position:0% +time T So if I draw a little diagram + + + align:start position:0% +time T So if I draw a little diagram +we've got some origin to our coordinate + + align:start position:0% +we've got some origin to our coordinate + + + align:start position:0% +we've got some origin to our coordinate +system there's some Vector R of T which + + align:start position:0% +system there's some Vector R of T which + + + align:start position:0% +system there's some Vector R of T which +is our electron and then there's some + + align:start position:0% +is our electron and then there's some + + + align:start position:0% +is our electron and then there's some +Vector X which defines our Observer and + + align:start position:0% +Vector X which defines our Observer and + + + align:start position:0% +Vector X which defines our Observer and +so this is the vector R here we could + + align:start position:0% +so this is the vector R here we could + + + align:start position:0% +so this is the vector R here we could +get rid of this by just assuming either + + align:start position:0% +get rid of this by just assuming either + + + align:start position:0% +get rid of this by just assuming either +the Observer or the particle is at the + + align:start position:0% +the Observer or the particle is at the + + + align:start position:0% +the Observer or the particle is at the +origin of the coordinate system but as + + align:start position:0% +origin of the coordinate system but as + + + align:start position:0% +origin of the coordinate system but as +the particle is moving that's not + + align:start position:0% +the particle is moving that's not + + + align:start position:0% +the particle is moving that's not +necessarily particularly useful and so + + align:start position:0% +necessarily particularly useful and so + + + align:start position:0% +necessarily particularly useful and so +we're doing it in this more generalized + + align:start position:0% +we're doing it in this more generalized + + + align:start position:0% +we're doing it in this more generalized +way here so we'll talk about what + + align:start position:0% +way here so we'll talk about what + + + align:start position:0% +way here so we'll talk about what +happens to this term in a moment the + + align:start position:0% +happens to this term in a moment the + + + align:start position:0% +happens to this term in a moment the +second term inside here is one + + align:start position:0% +second term inside here is one + + + align:start position:0% +second term inside here is one +upon c^2 K cubed + + align:start position:0% +upon c^2 K cubed + + + align:start position:0% +upon c^2 K cubed +are R hat and we're just going to + + align:start position:0% +are R hat and we're just going to + + + align:start position:0% +are R hat and we're just going to +Define r hat is equal + + align:start position:0% +Define r hat is equal + + + align:start position:0% +Define r hat is equal +to the r Vector over the size of the r + + align:start position:0% +to the r Vector over the size of the r + + + align:start position:0% +to the r Vector over the size of the r +Vector so just a normalized vector and + + align:start position:0% +Vector so just a normalized vector and + + + align:start position:0% +Vector so just a normalized vector and +that R hat is crossed + + align:start position:0% + + + + align:start position:0% + +with r minus E upon + + align:start position:0% +with r minus E upon + + + align:start position:0% +with r minus E upon +C which is in turn crossed with V Dot + + align:start position:0% +C which is in turn crossed with V Dot + + + align:start position:0% +C which is in turn crossed with V Dot +upon C and That V Dot is going to be + + align:start position:0% +upon C and That V Dot is going to be + + + align:start position:0% +upon C and That V Dot is going to be +extremely important in a moment and I + + align:start position:0% +extremely important in a moment and I + + + align:start position:0% +extremely important in a moment and I +I'm going to + + align:start position:0% + + + + align:start position:0% + +close so we have two terms here we have + + align:start position:0% +close so we have two terms here we have + + + align:start position:0% +close so we have two terms here we have +a term which we call the + + align:start position:0% + + + + align:start position:0% + +nearfield and a term that we call the + + align:start position:0% + + + + align:start position:0% + +field we're not going to explicitly + + align:start position:0% +field we're not going to explicitly + + + align:start position:0% +field we're not going to explicitly +derive the magnetic field here because + + align:start position:0% +derive the magnetic field here because + + + align:start position:0% +derive the magnetic field here because +fortunately du to the property + + align:start position:0% +fortunately du to the property + + + align:start position:0% +fortunately du to the property +of electromagnetic waves in a vacuum and + + align:start position:0% +of electromagnetic waves in a vacuum and + + + align:start position:0% +of electromagnetic waves in a vacuum and +we're still talking about vacuum waves + + align:start position:0% +we're still talking about vacuum waves + + + align:start position:0% +we're still talking about vacuum waves +here B is simply equal to one upon + + align:start position:0% +here B is simply equal to one upon + + + align:start position:0% +here B is simply equal to one upon +c e + + align:start position:0% +c e + + + align:start position:0% +c e +Crossway R have like that so the + + align:start position:0% +Crossway R have like that so the + + + align:start position:0% +Crossway R have like that so the +magnetic field is perpendicular the + + align:start position:0% +magnetic field is perpendicular the + + + align:start position:0% +magnetic field is perpendicular the +electric field as we expect okay and + + align:start position:0% +electric field as we expect okay and + + + align:start position:0% +electric field as we expect okay and +this means + + align:start position:0% +this means + + + align:start position:0% +this means +that for the nearfield + + align:start position:0% + + + + align:start position:0% + +case + + align:start position:0% + + + + align:start position:0% + +we have a pointing Vector s which again + + align:start position:0% +we have a pointing Vector s which again + + + align:start position:0% +we have a pointing Vector s which again +is equal to e cross B some constants and + + align:start position:0% +is equal to e cross B some constants and + + + align:start position:0% +is equal to e cross B some constants and +that s is going to go as one over r^ 4 + + align:start position:0% +that s is going to go as one over r^ 4 + + + align:start position:0% +that s is going to go as one over r^ 4 +and from the farfield + + align:start position:0% + + + + align:start position:0% + +case that s is going to go like R and S + + align:start position:0% +case that s is going to go like R and S + + + align:start position:0% +case that s is going to go like R and S +is going to go as one upon R squ here we + + align:start position:0% + + + + align:start position:0% + +had so this straight away tells us if we + + align:start position:0% +had so this straight away tells us if we + + + align:start position:0% +had so this straight away tells us if we +consider the power through a sphere uh + + align:start position:0% +consider the power through a sphere uh + + + align:start position:0% +consider the power through a sphere uh +of some radius R this power the total + + align:start position:0% +of some radius R this power the total + + + align:start position:0% +of some radius R this power the total +power s integrated over the surface of + + align:start position:0% +power s integrated over the surface of + + + align:start position:0% +power s integrated over the surface of +the sphere will drop off as R squar for + + align:start position:0% +the sphere will drop off as R squar for + + + align:start position:0% +the sphere will drop off as R squar for +the near field but it will stay constant + + align:start position:0% +the near field but it will stay constant + + + align:start position:0% +the near field but it will stay constant +for the far field so only the far field + + align:start position:0% +for the far field so only the far field + + + align:start position:0% +for the far field so only the far field +is actual propagating + + align:start position:0% +is actual propagating + + + align:start position:0% +is actual propagating +radiation that's the only thing we're + + align:start position:0% +radiation that's the only thing we're + + + align:start position:0% +radiation that's the only thing we're +actually going to + + align:start position:0% + + + + align:start position:0% + +observe so we don't actually need to + + align:start position:0% +observe so we don't actually need to + + + align:start position:0% +observe so we don't actually need to +have this nearfield term in the + + align:start position:0% +have this nearfield term in the + + + align:start position:0% +have this nearfield term in the +equations we're looking at it just drops + + align:start position:0% +equations we're looking at it just drops + + + align:start position:0% +equations we're looking at it just drops +out when you solve this + + align:start position:0% +out when you solve this + + + align:start position:0% +out when you solve this +equation so propagating E and M E + + align:start position:0% + + + + align:start position:0% + +rad the only reason to show you this + + align:start position:0% +rad the only reason to show you this + + + align:start position:0% +rad the only reason to show you this +is first of all to show as many of you + + align:start position:0% +is first of all to show as many of you + + + align:start position:0% +is first of all to show as many of you +know that the radiation even from a + + align:start position:0% +know that the radiation even from a + + + align:start position:0% +know that the radiation even from a +single moving charge is very complicated + + align:start position:0% +single moving charge is very complicated + + + align:start position:0% +single moving charge is very complicated +and then of course we have to ask what + + align:start position:0% +and then of course we have to ask what + + + align:start position:0% +and then of course we have to ask what +is it that we're trying to achieve in a + + align:start position:0% + + + + align:start position:0% + +plasma so the first thing we want to do + + align:start position:0% +plasma so the first thing we want to do + + + align:start position:0% +plasma so the first thing we want to do +in a + + align:start position:0% + + + + align:start position:0% + +plasma is we noticed that our near field + + align:start position:0% +plasma is we noticed that our near field + + + align:start position:0% +plasma is we noticed that our near field +far field term has lots of things we + + align:start position:0% +far field term has lots of things we + + + align:start position:0% +far field term has lots of things we +might know like where we're sitting and + + align:start position:0% +might know like where we're sitting and + + + align:start position:0% +might know like where we're sitting and +how long it's been but there are several + + align:start position:0% +how long it's been but there are several + + + align:start position:0% +how long it's been but there are several +things inside here that we don't know + + align:start position:0% +things inside here that we don't know + + + align:start position:0% +things inside here that we don't know +such as V and V Dot so that tells us + + align:start position:0% +such as V and V Dot so that tells us + + + align:start position:0% +such as V and V Dot so that tells us +that we're going to need to + + align:start position:0% +that we're going to need to + + + align:start position:0% +that we're going to need to +solve the equation + + align:start position:0% +solve the equation + + + align:start position:0% +solve the equation +of motion for a particle something that + + align:start position:0% +of motion for a particle something that + + + align:start position:0% +of motion for a particle something that +you've done several times in a plasma + + align:start position:0% +you've done several times in a plasma + + + align:start position:0% +you've done several times in a plasma +already without a magnetic field with a + + align:start position:0% +already without a magnetic field with a + + + align:start position:0% +already without a magnetic field with a +magnetic field you know this is the + + align:start position:0% +magnetic field you know this is the + + + align:start position:0% +magnetic field you know this is the +thing that tells you that the particles + + align:start position:0% +thing that tells you that the particles + + + align:start position:0% +thing that tells you that the particles +are spiraling around field lines and + + align:start position:0% +are spiraling around field lines and + + + align:start position:0% +are spiraling around field lines and +because they're spiraling they're + + align:start position:0% +because they're spiraling they're + + + align:start position:0% +because they're spiraling they're +continuously being accelerated and so we + + align:start position:0% +continuously being accelerated and so we + + + align:start position:0% +continuously being accelerated and so we +know straight away that these + + align:start position:0% +know straight away that these + + + align:start position:0% +know straight away that these +accelerated particles are going to be + + align:start position:0% +accelerated particles are going to be + + + align:start position:0% +accelerated particles are going to be +admitting propagating em radiation and + + align:start position:0% +admitting propagating em radiation and + + + align:start position:0% +admitting propagating em radiation and +that's the thing that we want to detect + + align:start position:0% +that's the thing that we want to detect + + + align:start position:0% +that's the thing that we want to detect +so first of all have to solve for the + + align:start position:0% +so first of all have to solve for the + + + align:start position:0% +so first of all have to solve for the +equation of motion but the second thing + + align:start position:0% +equation of motion but the second thing + + + align:start position:0% +equation of motion but the second thing +we'll have to + + align:start position:0% +we'll have to + + + align:start position:0% +we'll have to +do is + + align:start position:0% + + + + align:start position:0% + +integrate over our distribution function + + align:start position:0% +integrate over our distribution function + + + align:start position:0% +integrate over our distribution function +f of B E3 + + align:start position:0% + + + + align:start position:0% + +because we will then with once we solve + + align:start position:0% +because we will then with once we solve + + + align:start position:0% +because we will then with once we solve +the equation of motion we'll have it for + + align:start position:0% +the equation of motion we'll have it for + + + align:start position:0% +the equation of motion we'll have it for +a single particle but the particles have + + align:start position:0% +a single particle but the particles have + + + align:start position:0% +a single particle but the particles have +different velocities depending on where + + align:start position:0% +different velocities depending on where + + + align:start position:0% +different velocities depending on where +they fall in this distribution function + + align:start position:0% +they fall in this distribution function + + + align:start position:0% +they fall in this distribution function +and they may have different velocities + + align:start position:0% +and they may have different velocities + + + align:start position:0% +and they may have different velocities +in different directions they may have + + align:start position:0% +in different directions they may have + + + align:start position:0% +in different directions they may have +one velocity along the magnetic field + + align:start position:0% +one velocity along the magnetic field + + + align:start position:0% +one velocity along the magnetic field +and another amount velocity + + align:start position:0% +and another amount velocity + + + align:start position:0% +and another amount velocity +perpendicular to the magnetic field and + + align:start position:0% +perpendicular to the magnetic field and + + + align:start position:0% +perpendicular to the magnetic field and +so these two steps are very non-trivial + + align:start position:0% +so these two steps are very non-trivial + + + align:start position:0% +so these two steps are very non-trivial +to do properly and these are the steps + + align:start position:0% +to do properly and these are the steps + + + align:start position:0% +to do properly and these are the steps +that we're going to skip in this class + + align:start position:0% +that we're going to skip in this class + + + align:start position:0% +that we're going to skip in this class +we're just going to give the results + + align:start position:0% +we're just going to give the results + + + align:start position:0% +we're just going to give the results +from this but you know if you want to do + + align:start position:0% +from this but you know if you want to do + + + align:start position:0% +from this but you know if you want to do +this probably if you want to work with + + align:start position:0% +this probably if you want to work with + + + align:start position:0% +this probably if you want to work with +electron cyron emission you could + + align:start position:0% +electron cyron emission you could + + + align:start position:0% +electron cyron emission you could +probably go back and check can actually + + align:start position:0% +probably go back and check can actually + + + align:start position:0% +probably go back and check can actually +do all these intermediate steps okay we + + align:start position:0% +do all these intermediate steps okay we + + + align:start position:0% +do all these intermediate steps okay we +are kind of well over time I'm happy to + + align:start position:0% +are kind of well over time I'm happy to + + + align:start position:0% +are kind of well over time I'm happy to +take questions but otherwise I will see + + align:start position:0% +take questions but otherwise I will see + + + align:start position:0% +take questions but otherwise I will see +you on + + align:start position:0% + + + + align:start position:0% + +Thursday \ No newline at end of file diff --git a/6i6sV8WIzLc.txt b/6i6sV8WIzLc.txt new file mode 100644 index 0000000000000000000000000000000000000000..62c3064003b4bb186d15eb590ca3b40d70703204 --- /dev/null +++ b/6i6sV8WIzLc.txt @@ -0,0 +1,9197 @@ +align:start position:0% + +Okay. So, so right. So just to remind + + align:start position:0% +Okay. So, so right. So just to remind + + + align:start position:0% +Okay. So, so right. So just to remind +you, so so last time, + + align:start position:0% +you, so so last time, + + + align:start position:0% +you, so so last time, +so last time we looked at we had this + + align:start position:0% +so last time we looked at we had this + + + align:start position:0% +so last time we looked at we had this +sort of motivating example that we had a + + align:start position:0% +sort of motivating example that we had a + + + align:start position:0% +sort of motivating example that we had a +graph, we had a function f defined on + + align:start position:0% +graph, we had a function f defined on + + + align:start position:0% +graph, we had a function f defined on +some interval from a to b and it was + + align:start position:0% +some interval from a to b and it was + + + align:start position:0% +some interval from a to b and it was +going inside the real numbers and it + + align:start position:0% +going inside the real numbers and it + + + align:start position:0% +going inside the real numbers and it +started off negative here. This here is + + align:start position:0% +started off negative here. This here is + + + align:start position:0% +started off negative here. This here is +f of a. This is negative and it ended up + + align:start position:0% +f of a. This is negative and it ended up + + + align:start position:0% +f of a. This is negative and it ended up +positive + + align:start position:0% +positive + + + align:start position:0% +positive +f of b and we wanted to say and this was + + align:start position:0% +f of b and we wanted to say and this was + + + align:start position:0% +f of b and we wanted to say and this was +a continuous function + + align:start position:0% +a continuous function + + + align:start position:0% +a continuous function +uh + + align:start position:0% + + + + align:start position:0% + +and we wanted to say that there was some + + align:start position:0% +and we wanted to say that there was some + + + align:start position:0% +and we wanted to say that there was some +c. So we wanted to + + align:start position:0% + + + + align:start position:0% + +to um show + + align:start position:0% +to um show + + + align:start position:0% +to um show +that there's a C between A and B so that + + align:start position:0% +that there's a C between A and B so that + + + align:start position:0% +that there's a C between A and B so that +the value at C is equal to zero. So this + + align:start position:0% +the value at C is equal to zero. So this + + + align:start position:0% +the value at C is equal to zero. So this +was the intermediate values then + + align:start position:0% + + + + align:start position:0% + +and so this was sort of the motivation + + align:start position:0% +and so this was sort of the motivation + + + align:start position:0% +and so this was sort of the motivation +for + + align:start position:0% +for + + + align:start position:0% +for +the motivation this here was a + + align:start position:0% +the motivation this here was a + + + align:start position:0% +the motivation this here was a +motivating example for trying to + + align:start position:0% +motivating example for trying to + + + align:start position:0% +motivating example for trying to +understand what property of R do we + + align:start position:0% +understand what property of R do we + + + align:start position:0% +understand what property of R do we +need. So so the so what property + + align:start position:0% + + + + align:start position:0% + +of R. Do we need + + align:start position:0% + + + + align:start position:0% + +uh to make this + + align:start position:0% + + + + align:start position:0% + +to make this rigorous? So that was the + + align:start position:0% +to make this rigorous? So that was the + + + align:start position:0% +to make this rigorous? So that was the +that was sort of the motivating example, + + align:start position:0% +that was sort of the motivating example, + + + align:start position:0% +that was sort of the motivating example, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +And so in order to make this rigorous + + align:start position:0% +And so in order to make this rigorous + + + align:start position:0% +And so in order to make this rigorous +well then we we need the concept of we + + align:start position:0% +well then we we need the concept of we + + + align:start position:0% +well then we we need the concept of we +need need to concept of that r we need + + align:start position:0% +need need to concept of that r we need + + + align:start position:0% +need need to concept of that r we need +to understand um uh the following + + align:start position:0% +to understand um uh the following + + + align:start position:0% +to understand um uh the following +statement that r is a complete + + align:start position:0% + + + + align:start position:0% + +uh ordered + + align:start position:0% +uh ordered + + + align:start position:0% +uh ordered +uh field + + align:start position:0% + + + + align:start position:0% + +and a field here. So field here just + + align:start position:0% +and a field here. So field here just + + + align:start position:0% +and a field here. So field here just +briefly field here right was a set + + align:start position:0% + + + + align:start position:0% + +with uh two operations + + align:start position:0% + + + + align:start position:0% + +uh plus + + align:start position:0% +uh plus + + + align:start position:0% +uh plus +and uh and what we call multiplication + + align:start position:0% + + + + align:start position:0% + +each of these. + + align:start position:0% + + + + align:start position:0% + +So each of these + + align:start position:0% +So each of these + + + align:start position:0% +So each of these +two operations + + align:start position:0% + + + + align:start position:0% + +have uh five property + + align:start position:0% + + + + align:start position:0% + +and then there's an 11th property uh + + align:start position:0% +and then there's an 11th property uh + + + align:start position:0% +and then there's an 11th property uh +plus then there's an 11th property + + align:start position:0% + + + + align:start position:0% + +that chain them together + + align:start position:0% + + + + align:start position:0% + +and the last one is usually referred to + + align:start position:0% +and the last one is usually referred to + + + align:start position:0% +and the last one is usually referred to +as a distributive law. + + align:start position:0% +as a distributive law. + + + align:start position:0% +as a distributive law. +So, so that was one of the two important + + align:start position:0% +So, so that was one of the two important + + + align:start position:0% +So, so that was one of the two important +concept that we talked about last time. + + align:start position:0% +concept that we talked about last time. + + + align:start position:0% +concept that we talked about last time. +The other concept that we talked about + + align:start position:0% +The other concept that we talked about + + + align:start position:0% +The other concept that we talked about +was what's called an ordered set. + + align:start position:0% + + + + align:start position:0% + +So uh so so that's a set uh with an + + align:start position:0% +So uh so so that's a set uh with an + + + align:start position:0% +So uh so so that's a set uh with an +ordering + + align:start position:0% +ordering + + + align:start position:0% +ordering +and the ordering has to have the + + align:start position:0% +and the ordering has to have the + + + align:start position:0% +and the ordering has to have the +property that so this here the ordering + + align:start position:0% +property that so this here the ordering + + + align:start position:0% +property that so this here the ordering +has the property. + + align:start position:0% +has the property. + + + align:start position:0% +has the property. +So it has actually two properties. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Uh the first one is that whenever you + + align:start position:0% +Uh the first one is that whenever you + + + align:start position:0% +Uh the first one is that whenever you +take an element x and an element y in + + align:start position:0% +take an element x and an element y in + + + align:start position:0% +take an element x and an element y in +the set then either you should be able + + align:start position:0% +the set then either you should be able + + + align:start position:0% +the set then either you should be able +to relate these two by the ordering. So + + align:start position:0% +to relate these two by the ordering. So + + + align:start position:0% +to relate these two by the ordering. So +either + + align:start position:0% + + + + align:start position:0% + +x is equal to y or x is smaller than y + + align:start position:0% +x is equal to y or x is smaller than y + + + align:start position:0% +x is equal to y or x is smaller than y +uh or uh or uh y is smaller than x. + + align:start position:0% + + + + align:start position:0% + +And the second property is what's called + + align:start position:0% +And the second property is what's called + + + align:start position:0% +And the second property is what's called +transitive that if X and Y and C are + + align:start position:0% +transitive that if X and Y and C are + + + align:start position:0% +transitive that if X and Y and C are +element in the set + + align:start position:0% +element in the set + + + align:start position:0% +element in the set +and X is less than Y and + + align:start position:0% +and X is less than Y and + + + align:start position:0% +and X is less than Y and +Y is less than C then + + align:start position:0% +Y is less than C then + + + align:start position:0% +Y is less than C then +X should be less than C. So this is the + + align:start position:0% +X should be less than C. So this is the + + + align:start position:0% +X should be less than C. So this is the +22 property. + + align:start position:0% +22 property. + + + align:start position:0% +22 property. +So the first property again is that you + + align:start position:0% +So the first property again is that you + + + align:start position:0% +So the first property again is that you +can compare any two elements and the + + align:start position:0% +can compare any two elements and the + + + align:start position:0% +can compare any two elements and the +second one is this transitive law. Okay. + + align:start position:0% +second one is this transitive law. Okay. + + + align:start position:0% +second one is this transitive law. Okay. +And then so that was the two concepts we + + align:start position:0% +And then so that was the two concepts we + + + align:start position:0% +And then so that was the two concepts we +we talked about last time and then we + + align:start position:0% +we talked about last time and then we + + + align:start position:0% +we talked about last time and then we +talked about uh what it meant to be an + + align:start position:0% +talked about uh what it meant to be an + + + align:start position:0% +talked about uh what it meant to be an +ordered field. So so then we also talked + + align:start position:0% +ordered field. So so then we also talked + + + align:start position:0% +ordered field. So so then we also talked +about + + align:start position:0% + + + + align:start position:0% + +ordered fields and an ordered field is + + align:start position:0% +ordered fields and an ordered field is + + + align:start position:0% +ordered fields and an ordered field is +right. You have a field that is also an + + align:start position:0% +right. You have a field that is also an + + + align:start position:0% +right. You have a field that is also an +ordered set and then those two uh then + + align:start position:0% +ordered set and then those two uh then + + + align:start position:0% +ordered set and then those two uh then +the then the relationship so this will + + align:start position:0% +the then the relationship so this will + + + align:start position:0% +the then the relationship so this will +that one being less than the other one + + align:start position:0% +that one being less than the other one + + + align:start position:0% +that one being less than the other one +have to interact. So this is these two + + align:start position:0% +have to interact. So this is these two + + + align:start position:0% +have to interact. So this is these two +things that if you take x is less than y + + align:start position:0% +things that if you take x is less than y + + + align:start position:0% +things that if you take x is less than y +and you're adding any elements on both + + align:start position:0% +and you're adding any elements on both + + + align:start position:0% +and you're adding any elements on both +sides + + align:start position:0% +sides + + + align:start position:0% +sides +then uh it still preserve the order. + + align:start position:0% +then uh it still preserve the order. + + + align:start position:0% +then uh it still preserve the order. +So this is one thing and the second is + + align:start position:0% +So this is one thing and the second is + + + align:start position:0% +So this is one thing and the second is +that if you take x that's bigger than + + align:start position:0% +that if you take x that's bigger than + + + align:start position:0% +that if you take x that's bigger than +zero and y that's bigger than zero then + + align:start position:0% +zero and y that's bigger than zero then + + + align:start position:0% +zero and y that's bigger than zero then +the product + + align:start position:0% +the product + + + align:start position:0% +the product +of x and y should be bigger than zero + + align:start position:0% +of x and y should be bigger than zero + + + align:start position:0% +of x and y should be bigger than zero +and so this is how the the right so an + + align:start position:0% +and so this is how the the right so an + + + align:start position:0% +and so this is how the the right so an +ordered field again is a field that as a + + align:start position:0% +ordered field again is a field that as a + + + align:start position:0% +ordered field again is a field that as a +set is also has an ordering and then the + + align:start position:0% +set is also has an ordering and then the + + + align:start position:0% +set is also has an ordering and then the +ordering ing together with the operation + + align:start position:0% +ordering ing together with the operation + + + align:start position:0% +ordering ing together with the operation +of the field should be chained together + + align:start position:0% +of the field should be chained together + + + align:start position:0% +of the field should be chained together +by these two laws. Okay. + + align:start position:0% +by these two laws. Okay. + + + align:start position:0% +by these two laws. Okay. +Now, so we are we are we're getting + + align:start position:0% +Now, so we are we are we're getting + + + align:start position:0% +Now, so we are we are we're getting +close to understanding this, right? So, + + align:start position:0% +close to understanding this, right? So, + + + align:start position:0% +close to understanding this, right? So, +so this question is so in order for all + + align:start position:0% +so this question is so in order for all + + + align:start position:0% +so this question is so in order for all +of this to make sense, + + align:start position:0% +of this to make sense, + + + align:start position:0% +of this to make sense, +we need to understand what it means that + + align:start position:0% +we need to understand what it means that + + + align:start position:0% +we need to understand what it means that +the real numbers is a complete ordered + + align:start position:0% +the real numbers is a complete ordered + + + align:start position:0% +the real numbers is a complete ordered +field, right? And so we have now this + + align:start position:0% +field, right? And so we have now this + + + align:start position:0% +field, right? And so we have now this +part of it that it's an ordered field. + + align:start position:0% +part of it that it's an ordered field. + + + align:start position:0% +part of it that it's an ordered field. +We understand that this here is uh we + + align:start position:0% +We understand that this here is uh we + + + align:start position:0% +We understand that this here is uh we +need to understand what this means. + + align:start position:0% +need to understand what this means. + + + align:start position:0% +need to understand what this means. +Okay. So now before I get into that + + align:start position:0% +Okay. So now before I get into that + + + align:start position:0% +Okay. So now before I get into that +let's just talk about so what is the + + align:start position:0% +let's just talk about so what is the + + + align:start position:0% +let's just talk about so what is the +difference + + align:start position:0% + + + + align:start position:0% + +the difference + + align:start position:0% + + + + align:start position:0% + +between + + align:start position:0% + + + + align:start position:0% + +uh the real numbers and the rational + + align:start position:0% +uh the real numbers and the rational + + + align:start position:0% +uh the real numbers and the rational +numbers, + + align:start position:0% +numbers, + + + align:start position:0% +numbers, +right? Remember the rational numbers are + + align:start position:0% +right? Remember the rational numbers are + + + align:start position:0% +right? Remember the rational numbers are +numbers of this form here where this is + + align:start position:0% +numbers of this form here where this is + + + align:start position:0% +numbers of this form here where this is +an integer and this is a natural number. + + align:start position:0% +an integer and this is a natural number. + + + align:start position:0% +an integer and this is a natural number. +So what is the difference between these + + align:start position:0% +So what is the difference between these + + + align:start position:0% +So what is the difference between these +two? + + align:start position:0% +two? + + + align:start position:0% +two? +But one difference is so one difference + + align:start position:0% + + + + align:start position:0% + +is that that square root of two + + align:start position:0% +is that that square root of two + + + align:start position:0% +is that that square root of two +um is is a real number + + align:start position:0% +um is is a real number + + + align:start position:0% +um is is a real number +but + + align:start position:0% +but + + + align:start position:0% +but +but not a rational number. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now let me try to explain why first why + + align:start position:0% +Now let me try to explain why first why + + + align:start position:0% +Now let me try to explain why first why +it's not a rational number. + + align:start position:0% +it's not a rational number. + + + align:start position:0% +it's not a rational number. +So let's try to see uh so what is square + + align:start position:0% +So let's try to see uh so what is square + + + align:start position:0% +So let's try to see uh so what is square +root of two? + + align:start position:0% + + + + align:start position:0% + +The square root of two. + + align:start position:0% +The square root of two. + + + align:start position:0% +The square root of two. +You can think about it as a number x and + + align:start position:0% +You can think about it as a number x and + + + align:start position:0% +You can think about it as a number x and +it has to have the property that if you + + align:start position:0% +it has to have the property that if you + + + align:start position:0% +it has to have the property that if you +multiply it by itself, so x * x or if + + align:start position:0% +multiply it by itself, so x * x or if + + + align:start position:0% +multiply it by itself, so x * x or if +you will x 2, this should be equal to + + align:start position:0% +you will x 2, this should be equal to + + + align:start position:0% +you will x 2, this should be equal to +two, right? It also should be positive, + + align:start position:0% +two, right? It also should be positive, + + + align:start position:0% +two, right? It also should be positive, +right? + + align:start position:0% + + + + align:start position:0% + +Now suppose so I claim that square<unk> + + align:start position:0% +Now suppose so I claim that square<unk> + + + align:start position:0% +Now suppose so I claim that square<unk> +of two is not a rational number. So by + + align:start position:0% +of two is not a rational number. So by + + + align:start position:0% +of two is not a rational number. So by +that I mean that so so I want to claim + + align:start position:0% +that I mean that so so I want to claim + + + align:start position:0% +that I mean that so so I want to claim +the following. + + align:start position:0% +the following. + + + align:start position:0% +the following. +[Applause] + + align:start position:0% + + + + align:start position:0% + +that does not exist. + + align:start position:0% + + + + align:start position:0% + +A rational number + + align:start position:0% + + + + align:start position:0% + +um x = to m / n. Well, again this here + + align:start position:0% +um x = to m / n. Well, again this here + + + align:start position:0% +um x = to m / n. Well, again this here +is a integer. This is a natural number. + + align:start position:0% +is a integer. This is a natural number. + + + align:start position:0% +is a integer. This is a natural number. +So that + + align:start position:0% + + + + align:start position:0% + +x² is equal to 2. + + align:start position:0% +x² is equal to 2. + + + align:start position:0% +x² is equal to 2. +So I claim that that's that that you + + align:start position:0% +So I claim that that's that that you + + + align:start position:0% +So I claim that that's that that you +don't have a rational number that is + + align:start position:0% +don't have a rational number that is + + + align:start position:0% +don't have a rational number that is +square root of two. Okay. Now let's try + + align:start position:0% +square root of two. Okay. Now let's try + + + align:start position:0% +square root of two. Okay. Now let's try +to prove that. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +So suppose suppose there was such a + + align:start position:0% +So suppose suppose there was such a + + + align:start position:0% +So suppose suppose there was such a +number. So so we want to prove it. So we + + align:start position:0% +number. So so we want to prove it. So we + + + align:start position:0% +number. So so we want to prove it. So we +prove by contradiction. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +So assume + + align:start position:0% +So assume + + + align:start position:0% +So assume +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +that there exist + + align:start position:0% + + + + align:start position:0% + +x that is a rational number. So it can + + align:start position:0% +x that is a rational number. So it can + + + align:start position:0% +x that is a rational number. So it can +be written in this form here where m is + + align:start position:0% +be written in this form here where m is + + + align:start position:0% +be written in this form here where m is +an integer + + align:start position:0% +an integer + + + align:start position:0% +an integer +and n is a natural number. + + align:start position:0% +and n is a natural number. + + + align:start position:0% +and n is a natural number. +So assume that there exist a x that is + + align:start position:0% +So assume that there exist a x that is + + + align:start position:0% +So assume that there exist a x that is +that is a rational number and so that + + align:start position:0% +that is a rational number and so that + + + align:start position:0% +that is a rational number and so that +the square is equal to two right. Well + + align:start position:0% +the square is equal to two right. Well + + + align:start position:0% +the square is equal to two right. Well +if that's the case then m + + align:start position:0% + + + + align:start position:0% + +over n so this here squared is supposed + + align:start position:0% +over n so this here squared is supposed + + + align:start position:0% +over n so this here squared is supposed +to be equal to two right. So this means + + align:start position:0% +to be equal to two right. So this means + + + align:start position:0% +to be equal to two right. So this means +that so this implies that m2 + + align:start position:0% +that so this implies that m2 + + + align:start position:0% +that so this implies that m2 +over n^2 is equal to 2 and this just + + align:start position:0% +over n^2 is equal to 2 and this just + + + align:start position:0% +over n^2 is equal to 2 and this just +multiplying over implies that m2 + + align:start position:0% + + + + align:start position:0% + +is equal to 2 n^2. + + align:start position:0% +is equal to 2 n^2. + + + align:start position:0% +is equal to 2 n^2. +Now when we write x as a rational + + align:start position:0% +Now when we write x as a rational + + + align:start position:0% +Now when we write x as a rational +number, of course we know that there are + + align:start position:0% +number, of course we know that there are + + + align:start position:0% +number, of course we know that there are +many ways of writing it as rational + + align:start position:0% +many ways of writing it as rational + + + align:start position:0% +many ways of writing it as rational +number because you can just if you have + + align:start position:0% +number because you can just if you have + + + align:start position:0% +number because you can just if you have +one then you can just multiply the + + align:start position:0% +one then you can just multiply the + + + align:start position:0% +one then you can just multiply the +denominator and denominator by an inte + + align:start position:0% +denominator and denominator by an inte + + + align:start position:0% +denominator and denominator by an inte +by a natural number sorry and then you + + align:start position:0% +by a natural number sorry and then you + + + align:start position:0% +by a natural number sorry and then you +get another representation right but we + + align:start position:0% +get another representation right but we + + + align:start position:0% +get another representation right but we +can assume so we may assume + + align:start position:0% +can assume so we may assume + + + align:start position:0% +can assume so we may assume +so when we have written so uh we may + + align:start position:0% +so when we have written so uh we may + + + align:start position:0% +so when we have written so uh we may +assume Assume + + align:start position:0% + + + + align:start position:0% + +that's m and n + + align:start position:0% +that's m and n + + + align:start position:0% +that's m and n +and n does not have a common factor, + + align:start position:0% + + + + align:start position:0% + +right? Because otherwise we could just + + align:start position:0% +right? Because otherwise we could just + + + align:start position:0% +right? Because otherwise we could just +reduce it. So we could reduce it until + + align:start position:0% +reduce it. So we could reduce it until + + + align:start position:0% +reduce it. So we could reduce it until +we they don't have a common factor. + + align:start position:0% + + + + align:start position:0% + +Right. + + align:start position:0% +Right. + + + align:start position:0% +Right. +Okay. So, so we we will assume that m + + align:start position:0% +Okay. So, so we we will assume that m + + + align:start position:0% +Okay. So, so we we will assume that m +and n do not have a common factor. We + + align:start position:0% +and n do not have a common factor. We + + + align:start position:0% +and n do not have a common factor. We +have now that m squ is equal to this. + + align:start position:0% +have now that m squ is equal to this. + + + align:start position:0% +have now that m squ is equal to this. +But this means that m here must be even. + + align:start position:0% +But this means that m here must be even. + + + align:start position:0% +But this means that m here must be even. +Right? So we have that since + + align:start position:0% + + + + align:start position:0% + +since m 2 is equal to 2 n + + align:start position:0% +since m 2 is equal to 2 n + + + align:start position:0% +since m 2 is equal to 2 n +squar. So it means that two is a is a + + align:start position:0% +squar. So it means that two is a is a + + + align:start position:0% +squar. So it means that two is a is a +factor in m squ. So it must actually be + + align:start position:0% +factor in m squ. So it must actually be + + + align:start position:0% +factor in m squ. So it must actually be +a factor in m. So it means that two here + + align:start position:0% +a factor in m. So it means that two here + + + align:start position:0% +a factor in m. So it means that two here +is a factor + + align:start position:0% + + + + align:start position:0% + +in m. In other words, m is even. + + align:start position:0% +in m. In other words, m is even. + + + align:start position:0% +in m. In other words, m is even. +But so you can write m here as two times + + align:start position:0% +But so you can write m here as two times + + + align:start position:0% +But so you can write m here as two times +another integer here. + + align:start position:0% +another integer here. + + + align:start position:0% +another integer here. +Right? + + align:start position:0% + + + + align:start position:0% + +But this means that m 2 is equal to 2 m1 + + align:start position:0% +But this means that m 2 is equal to 2 m1 + + + align:start position:0% +But this means that m 2 is equal to 2 m1 +squared which is equal to 4 m1 2 right + + align:start position:0% +squared which is equal to 4 m1 2 right + + + align:start position:0% +squared which is equal to 4 m1 2 right +and we already know that that is equal + + align:start position:0% +and we already know that that is equal + + + align:start position:0% +and we already know that that is equal +to 2 n^2 + + align:start position:0% +to 2 n^2 + + + align:start position:0% +to 2 n^2 +right so this means dividing by two on + + align:start position:0% +right so this means dividing by two on + + + align:start position:0% +right so this means dividing by two on +both sides it means that 2 m1^ 2 is + + align:start position:0% +both sides it means that 2 m1^ 2 is + + + align:start position:0% +both sides it means that 2 m1^ 2 is +equal to n but this means that sorry is + + align:start position:0% +equal to n but this means that sorry is + + + align:start position:0% +equal to n but this means that sorry is +equal to n^2 so this means that two here + + align:start position:0% +equal to n^2 so this means that two here + + + align:start position:0% +equal to n^2 so this means that two here +must be a factor in n right so this + + align:start position:0% +must be a factor in n right so this + + + align:start position:0% +must be a factor in n right so this +means here that two is also a factor + + align:start position:0% + + + + align:start position:0% + +in n but now you see that this is a + + align:start position:0% +in n but now you see that this is a + + + align:start position:0% +in n but now you see that this is a +contradiction + + align:start position:0% +contradiction + + + align:start position:0% +contradiction +so this is a contradiction because now + + align:start position:0% +so this is a contradiction because now + + + align:start position:0% +so this is a contradiction because now +what we have is that two two is a factor + + align:start position:0% +what we have is that two two is a factor + + + align:start position:0% +what we have is that two two is a factor +in m and two is a factor in n. So they + + align:start position:0% +in m and two is a factor in n. So they + + + align:start position:0% +in m and two is a factor in n. So they +have a common factor but we assume they + + align:start position:0% +have a common factor but we assume they + + + align:start position:0% +have a common factor but we assume they +didn't have a common factor. Right? So + + align:start position:0% +didn't have a common factor. Right? So + + + align:start position:0% +didn't have a common factor. Right? So +this prove so so we argued by + + align:start position:0% +this prove so so we argued by + + + align:start position:0% +this prove so so we argued by +contradiction. We assume there was a + + align:start position:0% +contradiction. We assume there was a + + + align:start position:0% +contradiction. We assume there was a +rational number so that the square of it + + align:start position:0% +rational number so that the square of it + + + align:start position:0% +rational number so that the square of it +was equal to two and we get a + + align:start position:0% +was equal to two and we get a + + + align:start position:0% +was equal to two and we get a +contradiction. So that could not be a + + align:start position:0% +contradiction. So that could not be a + + + align:start position:0% +contradiction. So that could not be a +rational number + + align:start position:0% +rational number + + + align:start position:0% +rational number +um uh that has a property that the + + align:start position:0% +um uh that has a property that the + + + align:start position:0% +um uh that has a property that the +square is equal to two. So so square + + align:start position:0% +square is equal to two. So so square + + + align:start position:0% +square is equal to two. So so square +root of two is definitely not a rational + + align:start position:0% +root of two is definitely not a rational + + + align:start position:0% +root of two is definitely not a rational +number. Okay. + + align:start position:0% +number. Okay. + + + align:start position:0% +number. Okay. +Now + + align:start position:0% + + + + align:start position:0% + +so now how do we think about + + align:start position:0% +so now how do we think about + + + align:start position:0% +so now how do we think about +uh how do we think about square root of + + align:start position:0% +uh how do we think about square root of + + + align:start position:0% +uh how do we think about square root of +two? So how do we fit + + align:start position:0% + + + + align:start position:0% + +square<unk> of two into the number + + align:start position:0% +square<unk> of two into the number + + + align:start position:0% +square<unk> of two into the number +system? + + align:start position:0% + + + + align:start position:0% + +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +Well, square root of two + + align:start position:0% +Well, square root of two + + + align:start position:0% +Well, square root of two +is if you think about it as a decimal + + align:start position:0% +is if you think about it as a decimal + + + align:start position:0% +is if you think about it as a decimal +uh number, then it is uh it starts with + + align:start position:0% +uh number, then it is uh it starts with + + + align:start position:0% +uh number, then it is uh it starts with +1.4 + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +uh uh 136 and then it 136 + + align:start position:0% +uh uh 136 and then it 136 + + + align:start position:0% +uh uh 136 and then it 136 +and then it continue like this. + + align:start position:0% +and then it continue like this. + + + align:start position:0% +and then it continue like this. +So one way of thinking about + + align:start position:0% +So one way of thinking about + + + align:start position:0% +So one way of thinking about +uh square root of two is that it is and + + align:start position:0% +uh square root of two is that it is and + + + align:start position:0% +uh square root of two is that it is and +we will come back to this at some later + + align:start position:0% +we will come back to this at some later + + + align:start position:0% +we will come back to this at some later +lecture. So we think about so so one way + + align:start position:0% +lecture. So we think about so so one way + + + align:start position:0% +lecture. So we think about so so one way +of thinking about + + align:start position:0% + + + + align:start position:0% + +square is true. is + + align:start position:0% +square is true. is + + + align:start position:0% +square is true. is +as a limit + + align:start position:0% +as a limit + + + align:start position:0% +as a limit +of a sequence of number. + + align:start position:0% + + + + align:start position:0% + +And that that that brings us to a + + align:start position:0% +And that that that brings us to a + + + align:start position:0% +And that that that brings us to a +another really important concept uh that + + align:start position:0% +another really important concept uh that + + + align:start position:0% +another really important concept uh that +we will talk uh much more about later is + + align:start position:0% +we will talk uh much more about later is + + + align:start position:0% +we will talk uh much more about later is +this with sequences and limits. And so + + align:start position:0% +this with sequences and limits. And so + + + align:start position:0% +this with sequences and limits. And so +if we want to think about it as a limit + + align:start position:0% +if we want to think about it as a limit + + + align:start position:0% +if we want to think about it as a limit +of a sequence, we think about maybe the + + align:start position:0% +of a sequence, we think about maybe the + + + align:start position:0% +of a sequence, we think about maybe the +number one + + align:start position:0% +number one + + + align:start position:0% +number one +first and then we think about 1.4 and + + align:start position:0% +first and then we think about 1.4 and + + + align:start position:0% +first and then we think about 1.4 and +then we think 1.4.1 + + align:start position:0% +then we think 1.4.1 + + + align:start position:0% +then we think 1.4.1 +and then 1.4 + + align:start position:0% +and then 1.4 + + + align:start position:0% +and then 1.4 + + align:start position:0% + + + align:start position:0% +and then 1.4 + + align:start position:0% + + + + align:start position:0% + +uh two etc. Right? And so you see that + + align:start position:0% +uh two etc. Right? And so you see that + + + align:start position:0% +uh two etc. Right? And so you see that +this here is a sequence of numbers. And + + align:start position:0% +this here is a sequence of numbers. And + + + align:start position:0% +this here is a sequence of numbers. And +so this is an increasing + + align:start position:0% + + + + align:start position:0% + +sequence of numbers + + align:start position:0% + + + + align:start position:0% + +of numbers. + + align:start position:0% + + + + align:start position:0% + +and and square root of two + + align:start position:0% +and and square root of two + + + align:start position:0% +and and square root of two +is the limit + + align:start position:0% + + + + align:start position:0% + +of the sequence. + + align:start position:0% + + + + align:start position:0% + +So again we will talk much more about uh + + align:start position:0% +So again we will talk much more about uh + + + align:start position:0% +So again we will talk much more about uh +sequences and limits uh later but this + + align:start position:0% +sequences and limits uh later but this + + + align:start position:0% +sequences and limits uh later but this +is just something to keep in mind as a + + align:start position:0% +is just something to keep in mind as a + + + align:start position:0% +is just something to keep in mind as a +kind of also motivating why we need to + + align:start position:0% +kind of also motivating why we need to + + + align:start position:0% +kind of also motivating why we need to +understand sequences and and limits and + + align:start position:0% +understand sequences and and limits and + + + align:start position:0% +understand sequences and and limits and +their limits. Okay. + + align:start position:0% + + + + align:start position:0% + +Okay. So this was so so we we now know + + align:start position:0% +Okay. So this was so so we we now know + + + align:start position:0% +Okay. So this was so so we we now know +maybe not super surprisingly but but we + + align:start position:0% +maybe not super surprisingly but but we + + + align:start position:0% +maybe not super surprisingly but but we +we know and you know see there was a + + align:start position:0% +we know and you know see there was a + + + align:start position:0% +we know and you know see there was a +very simple proof why uh the real + + align:start position:0% +very simple proof why uh the real + + + align:start position:0% +very simple proof why uh the real +numbers is larger than the rational + + align:start position:0% +numbers is larger than the rational + + + align:start position:0% +numbers is larger than the rational +numbers contain in particular square + + align:start position:0% +numbers contain in particular square + + + align:start position:0% +numbers contain in particular square +root of two uh that the rational numbers + + align:start position:0% +root of two uh that the rational numbers + + + align:start position:0% +root of two uh that the rational numbers +does not contain. + + align:start position:0% +does not contain. + + + align:start position:0% +does not contain. +we still need to and this is related to + + align:start position:0% +we still need to and this is related to + + + align:start position:0% +we still need to and this is related to +the completeness of R and why the + + align:start position:0% +the completeness of R and why the + + + align:start position:0% +the completeness of R and why the +rational numbers is not complete. Okay, + + align:start position:0% +rational numbers is not complete. Okay, + + + align:start position:0% +rational numbers is not complete. Okay, +but this is again what we're now working + + align:start position:0% +but this is again what we're now working + + + align:start position:0% +but this is again what we're now working +uh towards. So we're working towards + + align:start position:0% +uh towards. So we're working towards + + + align:start position:0% +uh towards. So we're working towards +what it means to for a field to be + + align:start position:0% +what it means to for a field to be + + + align:start position:0% +what it means to for a field to be +complete. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +So let me just write that and and and + + align:start position:0% +So let me just write that and and and + + + align:start position:0% +So let me just write that and and and +I'll explain it more but just this here + + align:start position:0% +I'll explain it more but just this here + + + align:start position:0% +I'll explain it more but just this here +is what we aiming towards + + align:start position:0% + + + + align:start position:0% + +completeness + + align:start position:0% +completeness + + + align:start position:0% +completeness +which is and I'll explain that at the + + align:start position:0% +which is and I'll explain that at the + + + align:start position:0% +which is and I'll explain that at the +least upper bound property. + + align:start position:0% + + + + align:start position:0% + +Okay. So suppose you take a ordered set. + + align:start position:0% +Okay. So suppose you take a ordered set. + + + align:start position:0% +Okay. So suppose you take a ordered set. +So suppose + + align:start position:0% + + + + align:start position:0% + +uh S is an ordered set. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So and the ordering we as usual with + + align:start position:0% +So and the ordering we as usual with + + + align:start position:0% +So and the ordering we as usual with +ordering + + align:start position:0% + + + + align:start position:0% + +we do by by this. + + align:start position:0% +we do by by this. + + + align:start position:0% +we do by by this. +So suppose S is an order set and suppose + + align:start position:0% +So suppose S is an order set and suppose + + + align:start position:0% +So suppose S is an order set and suppose +that A here is a subset of S. Then we + + align:start position:0% +that A here is a subset of S. Then we + + + align:start position:0% +that A here is a subset of S. Then we +say that + + align:start position:0% +say that + + + align:start position:0% +say that +we say that um + + align:start position:0% +we say that um + + + align:start position:0% +we say that um +m is an upper bound + + align:start position:0% + + + + align:start position:0% + +an upper bound for the subset + + align:start position:0% +an upper bound for the subset + + + align:start position:0% +an upper bound for the subset +for a + + align:start position:0% +for a + + + align:start position:0% +for a +if for all + + align:start position:0% + + + + align:start position:0% + +elements in a + + align:start position:0% +elements in a + + + align:start position:0% +elements in a +um + + align:start position:0% +um + + + align:start position:0% +um +m here + + align:start position:0% +m here + + + align:start position:0% +m here +is bigger or equal + + align:start position:0% +is bigger or equal + + + align:start position:0% +is bigger or equal +to a. So an upper bound is something + + align:start position:0% +to a. So an upper bound is something + + + align:start position:0% +to a. So an upper bound is something +that h of for a subset is something that + + align:start position:0% +that h of for a subset is something that + + + align:start position:0% +that h of for a subset is something that +has to be bigger than all the elements + + align:start position:0% +has to be bigger than all the elements + + + align:start position:0% +has to be bigger than all the elements +in the subset bigger equal to it could + + align:start position:0% +in the subset bigger equal to it could + + + align:start position:0% +in the subset bigger equal to it could +be equal to to one of the elements. + + align:start position:0% + + + + align:start position:0% + +So that's a upper bound. And so of + + align:start position:0% +So that's a upper bound. And so of + + + align:start position:0% +So that's a upper bound. And so of +course if you look at + + align:start position:0% + + + + align:start position:0% + +So a couple of examples here. + + align:start position:0% +So a couple of examples here. + + + align:start position:0% +So a couple of examples here. +So, + + align:start position:0% +So, + + + align:start position:0% +So, +so if you're looking at if the set here + + align:start position:0% +so if you're looking at if the set here + + + align:start position:0% +so if you're looking at if the set here +uh is + + align:start position:0% +uh is + + + align:start position:0% +uh is +is um if if the set here is let's say + + align:start position:0% +is um if if the set here is let's say + + + align:start position:0% +is um if if the set here is let's say +that the set is um so s is the natural + + align:start position:0% +that the set is um so s is the natural + + + align:start position:0% +that the set is um so s is the natural +numbers here and uh the subset here is + + align:start position:0% +numbers here and uh the subset here is + + + align:start position:0% +numbers here and uh the subset here is +one two three + + align:start position:0% +one two three + + + align:start position:0% +one two three +then the element so then the element + + align:start position:0% +then the element so then the element + + + align:start position:0% +then the element so then the element +four here is an upper bound + + align:start position:0% + + + + align:start position:0% + +for uh a + + align:start position:0% + + + + align:start position:0% + +um so four is an upper bound for a + + align:start position:0% +um so four is an upper bound for a + + + align:start position:0% +um so four is an upper bound for a +whereas + + align:start position:0% +whereas + + + align:start position:0% +whereas +right whereas um + + align:start position:0% +right whereas um + + + align:start position:0% +right whereas um +whereas two is not + + align:start position:0% +whereas two is not + + + align:start position:0% +whereas two is not +right obviously three is bigger than two + + align:start position:0% +right obviously three is bigger than two + + + align:start position:0% +right obviously three is bigger than two +so uh two is not an upper bound + + align:start position:0% + + + + align:start position:0% + +Another example is um another example is + + align:start position:0% +Another example is um another example is + + + align:start position:0% +Another example is um another example is +if you take uh if you take say if s is + + align:start position:0% +if you take uh if you take say if s is + + + align:start position:0% +if you take uh if you take say if s is +the the let's say s is the rational + + align:start position:0% +the the let's say s is the rational + + + align:start position:0% +the the let's say s is the rational +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +and uh and a here is the natural numbers + + align:start position:0% +and uh and a here is the natural numbers + + + align:start position:0% +and uh and a here is the natural numbers +then a + + align:start position:0% + + + + align:start position:0% + +Then uh a here does not have an upper + + align:start position:0% +Then uh a here does not have an upper + + + align:start position:0% +Then uh a here does not have an upper +bound. + + align:start position:0% + + + + align:start position:0% + +Okay. And I I'll I'll return to this + + align:start position:0% +Okay. And I I'll I'll return to this + + + align:start position:0% +Okay. And I I'll I'll return to this +uh this second example uh in just a + + align:start position:0% +uh this second example uh in just a + + + align:start position:0% +uh this second example uh in just a +minute. + + align:start position:0% +minute. + + + align:start position:0% +minute. +>> Okay. + + align:start position:0% + + + + align:start position:0% + +So, so that is what it means to be an + + align:start position:0% +So, so that is what it means to be an + + + align:start position:0% +So, so that is what it means to be an +upper bound. + + align:start position:0% +upper bound. + + + align:start position:0% +upper bound. +So, now + + align:start position:0% +So, now + + + align:start position:0% +So, now +there's another concept and that is a + + align:start position:0% +there's another concept and that is a + + + align:start position:0% +there's another concept and that is a +least upper bound. + + align:start position:0% + + + + align:start position:0% + +So there's another concept of the least + + align:start position:0% +So there's another concept of the least + + + align:start position:0% +So there's another concept of the least +up above. + + align:start position:0% + + + + align:start position:0% + +So again we have S is an ordered set. + + align:start position:0% + + + + align:start position:0% + +we have a here is a subset of s. + + align:start position:0% + + + + align:start position:0% + +Uh then we say that + + align:start position:0% + + + + align:start position:0% + +it's a subset of s maybe let me just + + align:start position:0% +it's a subset of s maybe let me just + + + align:start position:0% +it's a subset of s maybe let me just +point out that that is bounded + + align:start position:0% + + + + align:start position:0% + +Um so A is a subset of S that is + + align:start position:0% +Um so A is a subset of S that is + + + align:start position:0% +Um so A is a subset of S that is +bounded. Then we say that + + align:start position:0% +bounded. Then we say that + + + align:start position:0% +bounded. Then we say that +then we say + + align:start position:0% +then we say + + + align:start position:0% +then we say +that + + align:start position:0% +that + + + align:start position:0% +that +capital M is an upper bound + + align:start position:0% +capital M is an upper bound + + + align:start position:0% +capital M is an upper bound +is a a sorry is a least upper bound. + + align:start position:0% + + + + align:start position:0% + +least upper bound + + align:start position:0% +least upper bound + + + align:start position:0% +least upper bound +for a + + align:start position:0% +for a + + + align:start position:0% +for a +if + + align:start position:0% + + + + align:start position:0% + +m is + + align:start position:0% +m is + + + align:start position:0% +m is +an upper bound. So it has to be an upper + + align:start position:0% +an upper bound. So it has to be an upper + + + align:start position:0% +an upper bound. So it has to be an upper +bound + + align:start position:0% +bound + + + align:start position:0% +bound +and + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% +if + + + align:start position:0% +if +any other upper bound and for any other + + align:start position:0% +any other upper bound and for any other + + + align:start position:0% +any other upper bound and for any other +B + + align:start position:0% + + + + align:start position:0% + +other upper bound + + align:start position:0% + + + + align:start position:0% + +we have to have that for any other upper + + align:start position:0% +we have to have that for any other upper + + + align:start position:0% +we have to have that for any other upper +bound say M1 we have that m1 m1 has to + + align:start position:0% +bound say M1 we have that m1 m1 has to + + + align:start position:0% +bound say M1 we have that m1 m1 has to +be bigger equal to m. + + align:start position:0% + + + + align:start position:0% + +So it has a least upper bound + + align:start position:0% +So it has a least upper bound + + + align:start position:0% +So it has a least upper bound +if a boundary set has a least upper + + align:start position:0% +if a boundary set has a least upper + + + align:start position:0% +if a boundary set has a least upper +bound if there is an element that is the + + align:start position:0% +bound if there is an element that is the + + + align:start position:0% +bound if there is an element that is the +smallest to so to speak of the upper + + align:start position:0% +smallest to so to speak of the upper + + + align:start position:0% +smallest to so to speak of the upper +bound. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +And so now so now we are ready to to + + align:start position:0% +And so now so now we are ready to to + + + align:start position:0% +And so now so now we are ready to to +state what it means to be a complete + + align:start position:0% +state what it means to be a complete + + + align:start position:0% +state what it means to be a complete +order field. + + align:start position:0% + + + + align:start position:0% + +So a complete + + align:start position:0% + + + + align:start position:0% + +order field + + align:start position:0% + + + + align:start position:0% + +um is + + align:start position:0% + + + + align:start position:0% + +an ordered field. + + align:start position:0% + + + + align:start position:0% + +It's an order field so that uh so that + + align:start position:0% + + + + align:start position:0% + +uh any bounded subset + + align:start position:0% + + + + align:start position:0% + +subset + + align:start position:0% + + + + align:start position:0% + +has a least up. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +so that's a complete orders field and + + align:start position:0% +so that's a complete orders field and + + + align:start position:0% +so that's a complete orders field and +and so we have the foreign theorem that + + align:start position:0% +and so we have the foreign theorem that + + + align:start position:0% +and so we have the foreign theorem that +we're not going to prove because that + + align:start position:0% +we're not going to prove because that + + + align:start position:0% +we're not going to prove because that +really takes us off field. + + align:start position:0% +really takes us off field. + + + align:start position:0% +really takes us off field. +Uh but but um so we just take it for + + align:start position:0% +Uh but but um so we just take it for + + + align:start position:0% +Uh but but um so we just take it for +granted. But there exist. + + align:start position:0% + + + + align:start position:0% + +So theorem + + align:start position:0% +So theorem + + + align:start position:0% +So theorem +exist the smallest + + align:start position:0% +exist the smallest + + + align:start position:0% +exist the smallest +uh so there exist + + align:start position:0% +uh so there exist + + + align:start position:0% +uh so there exist +a smallest + + align:start position:0% + + + + align:start position:0% + +complete + + align:start position:0% + + + + align:start position:0% + +uh ordered field + + align:start position:0% + + + + align:start position:0% + +that contains the rational numbers. + + align:start position:0% + + + + align:start position:0% + +uh numbers. + + align:start position:0% + + + + align:start position:0% + +Okay, so this is a theorem. Again, we + + align:start position:0% +Okay, so this is a theorem. Again, we + + + align:start position:0% +Okay, so this is a theorem. Again, we +won't prove it uh because it's really + + align:start position:0% +won't prove it uh because it's really + + + align:start position:0% +won't prove it uh because it's really +kind of outside in the scope of this + + align:start position:0% +kind of outside in the scope of this + + + align:start position:0% +kind of outside in the scope of this +class. It's not really what we want to + + align:start position:0% +class. It's not really what we want to + + + align:start position:0% +class. It's not really what we want to +focus on here. Uh but um but it but you + + align:start position:0% +focus on here. Uh but um but it but you + + + align:start position:0% +focus on here. Uh but um but it but you +can prove this. + + align:start position:0% +can prove this. + + + align:start position:0% +can prove this. +And so + + align:start position:0% +And so + + + align:start position:0% +And so +um so that field + + align:start position:0% + + + + align:start position:0% + +field + + align:start position:0% + + + + align:start position:0% + +is uh what we call r is it's a it's a + + align:start position:0% +is uh what we call r is it's a it's a + + + align:start position:0% +is uh what we call r is it's a it's a +real numbers. Okay. + + align:start position:0% + + + + align:start position:0% + +Um okay. So now I want to see + + align:start position:0% +Um okay. So now I want to see + + + align:start position:0% +Um okay. So now I want to see +uh why I want to see that if we work + + align:start position:0% +uh why I want to see that if we work + + + align:start position:0% +uh why I want to see that if we work +with that field instead of the rational + + align:start position:0% +with that field instead of the rational + + + align:start position:0% +with that field instead of the rational +numbers then actually we have in + + align:start position:0% +numbers then actually we have in + + + align:start position:0% +numbers then actually we have in +particular that uh the square root of + + align:start position:0% +particular that uh the square root of + + + align:start position:0% +particular that uh the square root of +two is in that + + align:start position:0% + + + + align:start position:0% + +So, so we will now see. So, we want to + + align:start position:0% +So, so we will now see. So, we want to + + + align:start position:0% +So, so we will now see. So, we want to +show + + align:start position:0% + + + + align:start position:0% + +that uh square root of two + + align:start position:0% + + + + align:start position:0% + +is in the real. Okay. + + align:start position:0% + + + + align:start position:0% + +So now I'm going to look at the set + + align:start position:0% +So now I'm going to look at the set + + + align:start position:0% +So now I'm going to look at the set +A. + + align:start position:0% +A. + + + align:start position:0% +A. +So I'm going to look at the set A which + + align:start position:0% +So I'm going to look at the set A which + + + align:start position:0% +So I'm going to look at the set A which +is the element + + align:start position:0% +is the element + + + align:start position:0% +is the element +um + + align:start position:0% +um + + + align:start position:0% +um +which is the element in R + + align:start position:0% +which is the element in R + + + align:start position:0% +which is the element in R +such that X here is bigger than zero. + + align:start position:0% +such that X here is bigger than zero. + + + align:start position:0% +such that X here is bigger than zero. +and uh x2 + + align:start position:0% +and uh x2 + + + align:start position:0% +and uh x2 +is uh is less than two. + + align:start position:0% +is uh is less than two. + + + align:start position:0% +is uh is less than two. +Okay. So I'm going to look at this set. + + align:start position:0% +Okay. So I'm going to look at this set. + + + align:start position:0% +Okay. So I'm going to look at this set. +Now of course this set here so a here + + align:start position:0% +Now of course this set here so a here + + + align:start position:0% +Now of course this set here so a here +is bounded. It's not empty. Let's say + + align:start position:0% +is bounded. It's not empty. Let's say + + + align:start position:0% +is bounded. It's not empty. Let's say +first it's not empty. + + align:start position:0% + + + + align:start position:0% + +Right? It's not empty since + + align:start position:0% +Right? It's not empty since + + + align:start position:0% +Right? It's not empty since +since one here is in a right one is + + align:start position:0% +since one here is in a right one is + + + align:start position:0% +since one here is in a right one is +positive and 1 squared here is of course + + align:start position:0% +positive and 1 squared here is of course + + + align:start position:0% +positive and 1 squared here is of course +one which is less than two + + align:start position:0% +one which is less than two + + + align:start position:0% +one which is less than two +so it's not empty and a here is also a + + align:start position:0% +so it's not empty and a here is also a + + + align:start position:0% +so it's not empty and a here is also a +is bible + + align:start position:0% + + + + align:start position:0% + +right because uh any element so for all + + align:start position:0% +right because uh any element so for all + + + align:start position:0% +right because uh any element so for all +X. + + align:start position:0% + + + + align:start position:0% + +So for all + + align:start position:0% +So for all + + + align:start position:0% +So for all +X in A + + align:start position:0% +X in A + + + align:start position:0% +X in A +uh you have that X squar is is it's X is + + align:start position:0% +uh you have that X squar is is it's X is + + + align:start position:0% +uh you have that X squar is is it's X is +positive and is less than two. So this + + align:start position:0% +positive and is less than two. So this + + + align:start position:0% +positive and is less than two. So this +means that X here must be itself less + + align:start position:0% +means that X here must be itself less + + + align:start position:0% +means that X here must be itself less +than two, right? Because two of course + + align:start position:0% +than two, right? Because two of course + + + align:start position:0% +than two, right? Because two of course +when you square it you're getting four, + + align:start position:0% +when you square it you're getting four, + + + align:start position:0% +when you square it you're getting four, +right? + + align:start position:0% + + + + align:start position:0% + +So it's a bounded. So a here is a + + align:start position:0% +So it's a bounded. So a here is a + + + align:start position:0% +So it's a bounded. So a here is a +bounded subset of the reals. + + align:start position:0% +bounded subset of the reals. + + + align:start position:0% +bounded subset of the reals. +[Applause] + + align:start position:0% + + + + align:start position:0% + +Now + + align:start position:0% +Now + + + align:start position:0% +Now +so now the real has the least upper + + align:start position:0% +so now the real has the least upper + + + align:start position:0% +so now the real has the least upper +bound property. + + align:start position:0% + + + + align:start position:0% + +So this means that I can now define + + align:start position:0% +So this means that I can now define + + + align:start position:0% +So this means that I can now define +so define + + align:start position:0% + + + + align:start position:0% + +square root of two + + align:start position:0% +square root of two + + + align:start position:0% +square root of two +to be the least up about + + align:start position:0% +to be the least up about + + + align:start position:0% +to be the least up about +define it to be + + align:start position:0% +define it to be + + + align:start position:0% +define it to be +the least up + + align:start position:0% + + + + align:start position:0% + +Okay, but a was a bounded it was a non- + + align:start position:0% +Okay, but a was a bounded it was a non- + + + align:start position:0% +Okay, but a was a bounded it was a non- +empty bounded subset. So because it we + + align:start position:0% +empty bounded subset. So because it we + + + align:start position:0% +empty bounded subset. So because it we +are in the reals + + align:start position:0% +are in the reals + + + align:start position:0% +are in the reals +if you grant this theorem then there is + + align:start position:0% +if you grant this theorem then there is + + + align:start position:0% +if you grant this theorem then there is +a least upper bound. Okay. + + align:start position:0% + + + + align:start position:0% + +So now + + align:start position:0% +So now + + + align:start position:0% +So now +let's denote. So it let me denote let me + + align:start position:0% +let's denote. So it let me denote let me + + + align:start position:0% +let's denote. So it let me denote let me +use + + align:start position:0% + + + + align:start position:0% + +denote + + align:start position:0% +denote + + + align:start position:0% +denote +this number + + align:start position:0% + + + + align:start position:0% + +by x. I'm going to denote it by x + + align:start position:0% +by x. I'm going to denote it by x + + + align:start position:0% +by x. I'm going to denote it by x +instead of square root two because if I + + align:start position:0% +instead of square root two because if I + + + align:start position:0% +instead of square root two because if I +if I denote it by square root two then + + align:start position:0% +if I denote it by square root two then + + + align:start position:0% +if I denote it by square root two then +it's going to be confusing right and + + align:start position:0% +it's going to be confusing right and + + + align:start position:0% +it's going to be confusing right and +it's like you know you will sort of + + align:start position:0% +it's like you know you will sort of + + + align:start position:0% +it's like you know you will sort of +automatically use what you think square + + align:start position:0% +automatically use what you think square + + + align:start position:0% +automatically use what you think square +root two should satisfy so let's not + + align:start position:0% +root two should satisfy so let's not + + + align:start position:0% +root two should satisfy so let's not +let's call it uh let's call it uh + + align:start position:0% +let's call it uh let's call it uh + + + align:start position:0% +let's call it uh let's call it uh +uh x + + align:start position:0% + + + + align:start position:0% + +so I want to prove so it's clear that + + align:start position:0% +so I want to prove so it's clear that + + + align:start position:0% +so I want to prove so it's clear that +since + + align:start position:0% +since + + + align:start position:0% +since +X here is at least up about + + align:start position:0% + + + + align:start position:0% + +for a + + align:start position:0% +for a + + + align:start position:0% +for a +and + + align:start position:0% +and + + + align:start position:0% +and +in particular one is in A then it means + + align:start position:0% +in particular one is in A then it means + + + align:start position:0% +in particular one is in A then it means +that one here has to be less or equal to + + align:start position:0% +that one here has to be less or equal to + + + align:start position:0% +that one here has to be less or equal to +X right and one of course is positive. + + align:start position:0% +X right and one of course is positive. + + + align:start position:0% +X right and one of course is positive. +So it means that X here is definitely + + align:start position:0% +So it means that X here is definitely + + + align:start position:0% +So it means that X here is definitely +false. Right? + + align:start position:0% +false. Right? + + + align:start position:0% +false. Right? +Now we need to show that we need to show + + align:start position:0% +Now we need to show that we need to show + + + align:start position:0% +Now we need to show that we need to show +that the square. + + align:start position:0% +that the square. + + + align:start position:0% +that the square. +So we need to show + + align:start position:0% + + + + align:start position:0% + +So we need to show + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +uh that x² + + align:start position:0% +uh that x² + + + align:start position:0% +uh that x² +is equal to two. Right? That's what we + + align:start position:0% +is equal to two. Right? That's what we + + + align:start position:0% +is equal to two. Right? That's what we +need to prove in order to prove that x + + align:start position:0% +need to prove in order to prove that x + + + align:start position:0% +need to prove in order to prove that x +is really the square root of two. Right? + + align:start position:0% + + + + align:start position:0% + +So I'm going to divide it up. So we + + align:start position:0% +So I'm going to divide it up. So we + + + align:start position:0% +So I'm going to divide it up. So we +divide the proof + + align:start position:0% + + + + align:start position:0% + +the proof + + align:start position:0% + + + + align:start position:0% + +into two steps. + + align:start position:0% + + + + align:start position:0% + +The first one is the first one is that + + align:start position:0% +The first one is the first one is that + + + align:start position:0% +The first one is the first one is that +we uh we want to so the first step. So + + align:start position:0% +we uh we want to so the first step. So + + + align:start position:0% +we uh we want to so the first step. So +step one + + align:start position:0% + + + + align:start position:0% + +we're going to show that x² is lesser + + align:start position:0% +we're going to show that x² is lesser + + + align:start position:0% +we're going to show that x² is lesser +equal to two. So this is what we will + + align:start position:0% +equal to two. So this is what we will + + + align:start position:0% +equal to two. So this is what we will +show in the first step. Right? And then + + align:start position:0% +show in the first step. Right? And then + + + align:start position:0% +show in the first step. Right? And then +the second step will be the reverse + + align:start position:0% +the second step will be the reverse + + + align:start position:0% +the second step will be the reverse +inequality. And of course together this + + align:start position:0% +inequality. And of course together this + + + align:start position:0% +inequality. And of course together this +would be the proof. Right? + + align:start position:0% + + + + align:start position:0% + +So again just like we argue uh before + + align:start position:0% +So again just like we argue uh before + + + align:start position:0% +So again just like we argue uh before +uh we're going to in this case we will + + align:start position:0% +uh we're going to in this case we will + + + align:start position:0% +uh we're going to in this case we will +also argue by contradiction. + + align:start position:0% +also argue by contradiction. + + + align:start position:0% +also argue by contradiction. +It's not a you may get the feeling that + + align:start position:0% +It's not a you may get the feeling that + + + align:start position:0% +It's not a you may get the feeling that +we're always going to argue by + + align:start position:0% +we're always going to argue by + + + align:start position:0% +we're always going to argue by +contradiction in this class and we won't + + align:start position:0% +contradiction in this class and we won't + + + align:start position:0% +contradiction in this class and we won't +and it's generally thought of that is + + align:start position:0% +and it's generally thought of that is + + + align:start position:0% +and it's generally thought of that is +better style to prove things directly + + align:start position:0% +better style to prove things directly + + + align:start position:0% +better style to prove things directly +but sometimes it's a much more logically + + align:start position:0% +but sometimes it's a much more logically + + + align:start position:0% +but sometimes it's a much more logically +logical and kind of easier in a way at + + align:start position:0% +logical and kind of easier in a way at + + + align:start position:0% +logical and kind of easier in a way at +least easier at the first time to prove + + align:start position:0% +least easier at the first time to prove + + + align:start position:0% +least easier at the first time to prove +it by contradiction and there's nothing + + align:start position:0% +it by contradiction and there's nothing + + + align:start position:0% +it by contradiction and there's nothing +wrong with proving it by contradiction. + + align:start position:0% +wrong with proving it by contradiction. + + + align:start position:0% +wrong with proving it by contradiction. +So we will show this by contradiction. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +And so + + align:start position:0% + + + + align:start position:0% + +so right. So we're going to show that + + align:start position:0% +so right. So we're going to show that + + + align:start position:0% +so right. So we're going to show that +[Applause] + + align:start position:0% + + + + align:start position:0% + +So we show this by contradiction and so + + align:start position:0% +So we show this by contradiction and so + + + align:start position:0% +So we show this by contradiction and so +we assume first. So assume + + align:start position:0% +we assume first. So assume + + + align:start position:0% +we assume first. So assume +assume not. + + align:start position:0% + + + + align:start position:0% + +So assume + + align:start position:0% +So assume + + + align:start position:0% +So assume +assume that x² is not less or equal to + + align:start position:0% +assume that x² is not less or equal to + + + align:start position:0% +assume that x² is not less or equal to +two. So we assume not. So + + align:start position:0% + + + + align:start position:0% + +assume + + align:start position:0% + + + + align:start position:0% + +that x² is strictly bigger than two. + + align:start position:0% + + + + align:start position:0% + +Now I will look at x minus some small + + align:start position:0% +Now I will look at x minus some small + + + align:start position:0% +Now I will look at x minus some small +number + + align:start position:0% +number + + + align:start position:0% +number +and I'm I'm going to eventually prove + + align:start position:0% +and I'm I'm going to eventually prove + + + align:start position:0% +and I'm I'm going to eventually prove +that if I'm looking at at x minus some + + align:start position:0% +that if I'm looking at at x minus some + + + align:start position:0% +that if I'm looking at at x minus some +small number + + align:start position:0% + + + + align:start position:0% + +I'm going to prove now that if this hair + + align:start position:0% +I'm going to prove now that if this hair + + + align:start position:0% +I'm going to prove now that if this hair +was strictly bigger than two then I can + + align:start position:0% +was strictly bigger than two then I can + + + align:start position:0% +was strictly bigger than two then I can +find some small number so that this here + + align:start position:0% +find some small number so that this here + + + align:start position:0% +find some small number so that this here +would also be an upper bound. So x + + align:start position:0% +would also be an upper bound. So x + + + align:start position:0% +would also be an upper bound. So x +h would be positive. + + align:start position:0% +h would be positive. + + + align:start position:0% +h would be positive. +This here would be a number strictly + + align:start position:0% +This here would be a number strictly + + + align:start position:0% +This here would be a number strictly +less than x. And I would show that this + + align:start position:0% +less than x. And I would show that this + + + align:start position:0% +less than x. And I would show that this +here is also of a bound. That's what I + + align:start position:0% +here is also of a bound. That's what I + + + align:start position:0% +here is also of a bound. That's what I +want to do. Okay. So I take x minus h + + align:start position:0% +want to do. Okay. So I take x minus h + + + align:start position:0% +want to do. Okay. So I take x minus h +and I square it. + + align:start position:0% +and I square it. + + + align:start position:0% +and I square it. +If I do that then I get that uh this is + + align:start position:0% +If I do that then I get that uh this is + + + align:start position:0% +If I do that then I get that uh this is +x2 + + align:start position:0% +x2 + + + align:start position:0% +x2 +minus 2 xh + + align:start position:0% +minus 2 xh + + + align:start position:0% +minus 2 xh ++ h 2 right the square is is not + + align:start position:0% ++ h 2 right the square is is not + + + align:start position:0% ++ h 2 right the square is is not +negative. So this here is definitely + + align:start position:0% +negative. So this here is definitely + + + align:start position:0% +negative. So this here is definitely +bigger equal to x^2 + + align:start position:0% +bigger equal to x^2 + + + align:start position:0% +bigger equal to x^2 +- 2 xh + + align:start position:0% + + + + align:start position:0% + +and so you see that right + + align:start position:0% +and so you see that right + + + align:start position:0% +and so you see that right +and so now + + align:start position:0% + + + + align:start position:0% + +so now uh if you take so now you have + + align:start position:0% +so now uh if you take so now you have + + + align:start position:0% +so now uh if you take so now you have +that x² + + align:start position:0% +that x² + + + align:start position:0% +that x² +is uh by we have that x2 is bigger than + + align:start position:0% +is uh by we have that x2 is bigger than + + + align:start position:0% +is uh by we have that x2 is bigger than +2. + + align:start position:0% +2. + + + align:start position:0% +2. +So this means that x^2 + + align:start position:0% +So this means that x^2 + + + align:start position:0% +So this means that x^2 +minus uh 2 is positive. I am just + + align:start position:0% +minus uh 2 is positive. I am just + + + align:start position:0% +minus uh 2 is positive. I am just +subtracting two from both sides. So this + + align:start position:0% +subtracting two from both sides. So this + + + align:start position:0% +subtracting two from both sides. So this +here is we're assuming that this here is + + align:start position:0% +here is we're assuming that this here is + + + align:start position:0% +here is we're assuming that this here is +positive. Right? + + align:start position:0% + + + + align:start position:0% + +And so now if I just make sure that um + + align:start position:0% +And so now if I just make sure that um + + + align:start position:0% +And so now if I just make sure that um +so if I now make sure that what I am so + + align:start position:0% +so if I now make sure that what I am so + + + align:start position:0% +so if I now make sure that what I am so +if I so now + + align:start position:0% +if I so now + + + align:start position:0% +if I so now +I'm going to choose so I want to choose + + align:start position:0% +I'm going to choose so I want to choose + + + align:start position:0% +I'm going to choose so I want to choose +so I want to prove that x minus so so + + align:start position:0% +so I want to prove that x minus so so + + + align:start position:0% +so I want to prove that x minus so so +want to show so I want to get the + + align:start position:0% +want to show so I want to get the + + + align:start position:0% +want to show so I want to get the +contradiction + + align:start position:0% + + + + align:start position:0% + +by finding a + + align:start position:0% +by finding a + + + align:start position:0% +by finding a +finding + + align:start position:0% +finding + + + align:start position:0% +finding +a h bigger than zero. + + align:start position:0% +a h bigger than zero. + + + align:start position:0% +a h bigger than zero. +So that + + align:start position:0% + + + + align:start position:0% + +x - h is also + + align:start position:0% + + + + align:start position:0% + +an upper bound + + align:start position:0% + + + + align:start position:0% + +for a right because this here is clearly + + align:start position:0% +for a right because this here is clearly + + + align:start position:0% +for a right because this here is clearly +smaller than x right and this would then + + align:start position:0% +smaller than x right and this would then + + + align:start position:0% +smaller than x right and this would then +contradict that x was the smallest upper + + align:start position:0% +contradict that x was the smallest upper + + + align:start position:0% +contradict that x was the smallest upper +part right so that's what I want to do + + align:start position:0% +part right so that's what I want to do + + + align:start position:0% +part right so that's what I want to do +and + + align:start position:0% +and + + + align:start position:0% +and +and so now how do I do that so using + + align:start position:0% +and so now how do I do that so using + + + align:start position:0% +and so now how do I do that so using +this little calculation here. + + align:start position:0% + + + + align:start position:0% + +So what I want to do is so I want to + + align:start position:0% +So what I want to do is so I want to + + + align:start position:0% +So what I want to do is so I want to +find so I want to find + + align:start position:0% + + + + align:start position:0% + +h positive + + align:start position:0% +h positive + + + align:start position:0% +h positive +so that + + align:start position:0% +so that + + + align:start position:0% +so that +when I square when I subtract h from x + + align:start position:0% +when I square when I subtract h from x + + + align:start position:0% +when I square when I subtract h from x +and I square it then I still get + + align:start position:0% +and I square it then I still get + + + align:start position:0% +and I square it then I still get +something bigger than two right so I + + align:start position:0% +something bigger than two right so I + + + align:start position:0% +something bigger than two right so I +want to find h positive so that This + + align:start position:0% +want to find h positive so that This + + + align:start position:0% +want to find h positive so that This +thing here + + align:start position:0% +thing here + + + align:start position:0% +thing here +is bigger than two, right? + + align:start position:0% +is bigger than two, right? + + + align:start position:0% +is bigger than two, right? +And all I need to do is from I need to + + align:start position:0% +And all I need to do is from I need to + + + align:start position:0% +And all I need to do is from I need to +show that I can find H. So that this in + + align:start position:0% +show that I can find H. So that this in + + + align:start position:0% +show that I can find H. So that this in +here. So enough to show + + align:start position:0% + + + + align:start position:0% + +to show + + align:start position:0% + + + + align:start position:0% + +that I can find find + + align:start position:0% +that I can find find + + + align:start position:0% +that I can find find +h such that + + align:start position:0% +h such that + + + align:start position:0% +h such that +x^2 + + align:start position:0% +x^2 + + + align:start position:0% +x^2 +- 2 xh that this thing here is bigger + + align:start position:0% +- 2 xh that this thing here is bigger + + + align:start position:0% +- 2 xh that this thing here is bigger +than two. + + align:start position:0% + + + + align:start position:0% + +Right? And so you see I now I just move + + align:start position:0% +Right? And so you see I now I just move + + + align:start position:0% +Right? And so you see I now I just move +over on the other side to say that this + + align:start position:0% +over on the other side to say that this + + + align:start position:0% +over on the other side to say that this +here is bigger than two. It's the same + + align:start position:0% +here is bigger than two. It's the same + + + align:start position:0% +here is bigger than two. It's the same +as saying I can just move this two over + + align:start position:0% +as saying I can just move this two over + + + align:start position:0% +as saying I can just move this two over +on that side + + align:start position:0% +on that side + + + align:start position:0% +on that side +and I can move this here over on the + + align:start position:0% +and I can move this here over on the + + + align:start position:0% +and I can move this here over on the +other side. So I just need to find + + align:start position:0% + + + + align:start position:0% + +h with this property. Right? But that of + + align:start position:0% +h with this property. Right? But that of + + + align:start position:0% +h with this property. Right? But that of +course is equivalent to saying that h + + align:start position:0% +course is equivalent to saying that h + + + align:start position:0% +course is equivalent to saying that h +has to be less than x^2 - 2 over 2x + + align:start position:0% +has to be less than x^2 - 2 over 2x + + + align:start position:0% +has to be less than x^2 - 2 over 2x +is positive. This thing here is strictly + + align:start position:0% +is positive. This thing here is strictly + + + align:start position:0% +is positive. This thing here is strictly +positive. So I can certainly find a + + align:start position:0% +positive. So I can certainly find a + + + align:start position:0% +positive. So I can certainly find a +positive number. This is something + + align:start position:0% +positive number. This is something + + + align:start position:0% +positive number. This is something +strictly positive. So I can certainly + + align:start position:0% +strictly positive. So I can certainly + + + align:start position:0% +strictly positive. So I can certainly +find some small h so that is less than + + align:start position:0% +find some small h so that is less than + + + align:start position:0% +find some small h so that is less than +this strictly positive number. Right? + + align:start position:0% +this strictly positive number. Right? + + + align:start position:0% +this strictly positive number. Right? +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +so this proves this is step one. This is + + align:start position:0% +so this proves this is step one. This is + + + align:start position:0% +so this proves this is step one. This is +just showing that x2 was less or equal + + align:start position:0% +just showing that x2 was less or equal + + + align:start position:0% +just showing that x2 was less or equal +to two. Right? Now I want to argue + + align:start position:0% +to two. Right? Now I want to argue + + + align:start position:0% +to two. Right? Now I want to argue +similarly + + align:start position:0% +similarly + + + align:start position:0% +similarly +um similarly to prove the other + + align:start position:0% +um similarly to prove the other + + + align:start position:0% +um similarly to prove the other +direction. Okay. + + align:start position:0% + + + + align:start position:0% + +I mean in this case there's not really + + align:start position:0% +I mean in this case there's not really + + + align:start position:0% +I mean in this case there's not really +any difference, right? I mean the you + + align:start position:0% +any difference, right? I mean the you + + + align:start position:0% +any difference, right? I mean the you +see in a minute that one inequality is + + align:start position:0% +see in a minute that one inequality is + + + align:start position:0% +see in a minute that one inequality is +not uh any easier than the other. Uh I + + align:start position:0% +not uh any easier than the other. Uh I + + + align:start position:0% +not uh any easier than the other. Uh I +have one I have a colleague here. He's + + align:start position:0% +have one I have a colleague here. He's + + + align:start position:0% +have one I have a colleague here. He's +retired now, but he and he collaborated + + align:start position:0% +retired now, but he and he collaborated + + + align:start position:0% +retired now, but he and he collaborated +with some other guy and they made a lot + + align:start position:0% +with some other guy and they made a lot + + + align:start position:0% +with some other guy and they made a lot +of famous work and the other guy maybe + + align:start position:0% +of famous work and the other guy maybe + + + align:start position:0% +of famous work and the other guy maybe +become even more famous and he used to + + align:start position:0% +become even more famous and he used to + + + align:start position:0% +become even more famous and he used to +say that when you do mathematics so it + + align:start position:0% +say that when you do mathematics so it + + + align:start position:0% +say that when you do mathematics so it +doesn't really apply here because the + + align:start position:0% +doesn't really apply here because the + + + align:start position:0% +doesn't really apply here because the +two inequality is just as easy but he + + align:start position:0% +two inequality is just as easy but he + + + align:start position:0% +two inequality is just as easy but he +used to say that when you do two when + + align:start position:0% +used to say that when you do two when + + + align:start position:0% +used to say that when you do two when +you do mathematics there's three things + + align:start position:0% +you do mathematics there's three things + + + align:start position:0% +you do mathematics there's three things +you do you locate a problem you prove + + align:start position:0% +you do you locate a problem you prove + + + align:start position:0% +you do you locate a problem you prove +one of the two inequality whichever one + + align:start position:0% +one of the two inequality whichever one + + + align:start position:0% +one of the two inequality whichever one +is easier + + align:start position:0% +is easier + + + align:start position:0% +is easier +and you ask Ragu. Rau was his + + align:start position:0% +and you ask Ragu. Rau was his + + + align:start position:0% +and you ask Ragu. Rau was his +collaborator to prove the other + + align:start position:0% +collaborator to prove the other + + + align:start position:0% +collaborator to prove the other +inequalities. + + align:start position:0% + + + + align:start position:0% + +Okay. So we so step two is um + + align:start position:0% + + + + align:start position:0% + +so step two is that uh x² + + align:start position:0% +so step two is that uh x² + + + align:start position:0% +so step two is that uh x² +is uh is bigger equal to two. Right? And + + align:start position:0% +is uh is bigger equal to two. Right? And + + + align:start position:0% +is uh is bigger equal to two. Right? And +we will again prove this. So again show + + align:start position:0% +we will again prove this. So again show + + + align:start position:0% +we will again prove this. So again show +this + + align:start position:0% + + + + align:start position:0% + +by contradiction. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So I assume + + align:start position:0% + + + + align:start position:0% + +not + + align:start position:0% +not + + + align:start position:0% +not +so I assume + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +uh x² here is strictly smaller than two. + + align:start position:0% + + + + align:start position:0% + +Now what we want to prove is so then we + + align:start position:0% +Now what we want to prove is so then we + + + align:start position:0% +Now what we want to prove is so then we +want to we want to get the + + align:start position:0% +want to we want to get the + + + align:start position:0% +want to we want to get the +contradiction. + + align:start position:0% +contradiction. + + + align:start position:0% +contradiction. +We want + + align:start position:0% +We want + + + align:start position:0% +We want +to get the contradiction + + align:start position:0% + + + + align:start position:0% + +by showing + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +X is not is not an upper bound. + + align:start position:0% +X is not is not an upper bound. + + + align:start position:0% +X is not is not an upper bound. +An upper bound for A. + + align:start position:0% + + + + align:start position:0% + +Right? X was supposed to be the least + + align:start position:0% +Right? X was supposed to be the least + + + align:start position:0% +Right? X was supposed to be the least +upper bound in particular and upper + + align:start position:0% +upper bound in particular and upper + + + align:start position:0% +upper bound in particular and upper +bound. + + align:start position:0% +bound. + + + align:start position:0% +bound. +So how do we do that? Well, we we're + + align:start position:0% +So how do we do that? Well, we we're + + + align:start position:0% +So how do we do that? Well, we we're +going to add just a little bit to X. + + align:start position:0% +going to add just a little bit to X. + + + align:start position:0% +going to add just a little bit to X. +So this is sort of similar to how we + + align:start position:0% +So this is sort of similar to how we + + + align:start position:0% +So this is sort of similar to how we +argued before. + + align:start position:0% + + + + align:start position:0% + +So, so, so I'm going to add, so h again + + align:start position:0% +So, so, so I'm going to add, so h again + + + align:start position:0% +So, so, so I'm going to add, so h again +is being positive. + + align:start position:0% +is being positive. + + + align:start position:0% +is being positive. +So, h is positive. + + align:start position:0% +So, h is positive. + + + align:start position:0% +So, h is positive. +And I'm going to add just a little bit + + align:start position:0% +And I'm going to add just a little bit + + + align:start position:0% +And I'm going to add just a little bit +to x. And I'm going to see that if I + + align:start position:0% +to x. And I'm going to see that if I + + + align:start position:0% +to x. And I'm going to see that if I +choose h small + + align:start position:0% +choose h small + + + align:start position:0% +choose h small +then then um I can find something in the + + align:start position:0% +then then um I can find something in the + + + align:start position:0% +then then um I can find something in the +set so that uh if I choose it so that x + + align:start position:0% +set so that uh if I choose it so that x + + + align:start position:0% +set so that uh if I choose it so that x +so I can so I want to prove that if h is + + align:start position:0% +so I can so I want to prove that if h is + + + align:start position:0% +so I can so I want to prove that if h is +small enough then x + h + + align:start position:0% +small enough then x + h + + + align:start position:0% +small enough then x + h +is an a okay contradicting that x was an + + align:start position:0% +is an a okay contradicting that x was an + + + align:start position:0% +is an a okay contradicting that x was an +upper bound. Okay. + + align:start position:0% +upper bound. Okay. + + + align:start position:0% +upper bound. Okay. +And so h is going to be chos small. So + + align:start position:0% +And so h is going to be chos small. So + + + align:start position:0% +And so h is going to be chos small. So +in particular, it's going to be between + + align:start position:0% +in particular, it's going to be between + + + align:start position:0% +in particular, it's going to be between +zero and one. Okay. And I'm looking at x + + align:start position:0% +zero and one. Okay. And I'm looking at x + + + align:start position:0% +zero and one. Okay. And I'm looking at x ++ h and I'm squaring it. So this thing + + align:start position:0% ++ h and I'm squaring it. So this thing + + + align:start position:0% ++ h and I'm squaring it. So this thing +here is x2 + h 2 + 2 h x. + + align:start position:0% +here is x2 + h 2 + 2 h x. + + + align:start position:0% +here is x2 + h 2 + 2 h x. +Now uh h here is less than one. So this + + align:start position:0% +Now uh h here is less than one. So this + + + align:start position:0% +Now uh h here is less than one. So this +means that 8 squar since + + align:start position:0% +means that 8 squar since + + + align:start position:0% +means that 8 squar since +since 8 is less is positive and is less + + align:start position:0% +since 8 is less is positive and is less + + + align:start position:0% +since 8 is less is positive and is less +than one then you have that h squar here + + align:start position:0% +than one then you have that h squar here + + + align:start position:0% +than one then you have that h squar here +sorry then you have that h squ is less + + align:start position:0% +sorry then you have that h squ is less + + + align:start position:0% +sorry then you have that h squ is less +than uh than actually h right + + align:start position:0% +than uh than actually h right + + + align:start position:0% +than uh than actually h right +and so this thing here is less than uh + + align:start position:0% +and so this thing here is less than uh + + + align:start position:0% +and so this thing here is less than uh +x2 + + align:start position:0% +x2 + + + align:start position:0% +x2 ++ h + 2 uh h X. + + align:start position:0% ++ h + 2 uh h X. + + + align:start position:0% ++ h + 2 uh h X. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +And I want to show So I want to show + + align:start position:0% +And I want to show So I want to show + + + align:start position:0% +And I want to show So I want to show +that I can So I want to show that this X + + align:start position:0% +that I can So I want to show that this X + + + align:start position:0% +that I can So I want to show that this X ++ H this is still in A. So I want to + + align:start position:0% ++ H this is still in A. So I want to + + + align:start position:0% ++ H this is still in A. So I want to +show + + align:start position:0% + + + + align:start position:0% + +that I can find that we can find + + align:start position:0% + + + + align:start position:0% + +such a + + align:start position:0% +such a + + + align:start position:0% +such a +such a h so that this here + + align:start position:0% +such a h so that this here + + + align:start position:0% +such a h so that this here +this here squared + + align:start position:0% +this here squared + + + align:start position:0% +this here squared +is still less than two. Right? + + align:start position:0% +is still less than two. Right? + + + align:start position:0% +is still less than two. Right? +But so all I need to do is because of + + align:start position:0% +But so all I need to do is because of + + + align:start position:0% +But so all I need to do is because of +this inequality I just need to find an h + + align:start position:0% +this inequality I just need to find an h + + + align:start position:0% +this inequality I just need to find an h +so that this thing here is less than + + align:start position:0% +so that this thing here is less than + + + align:start position:0% +so that this thing here is less than +two. Right? So I want to + + align:start position:0% + + + + align:start position:0% + +to find + + align:start position:0% +to find + + + align:start position:0% +to find +H such that + + align:start position:0% +H such that + + + align:start position:0% +H such that +this thing here + + align:start position:0% + + + + align:start position:0% + +is listen to right + + align:start position:0% + + + + align:start position:0% + +now. + + align:start position:0% + + + + align:start position:0% + +Now um right so now again we're just + + align:start position:0% +Now um right so now again we're just + + + align:start position:0% +Now um right so now again we're just +moving over on the other side we're + + align:start position:0% +moving over on the other side we're + + + align:start position:0% +moving over on the other side we're +moving this in this case we're moving + + align:start position:0% +moving this in this case we're moving + + + align:start position:0% +moving this in this case we're moving +this x squ over here so we have h + 2 h + + align:start position:0% +this x squ over here so we have h + 2 h + + + align:start position:0% +this x squ over here so we have h + 2 h +x is less than this is what we want to + + align:start position:0% +x is less than this is what we want to + + + align:start position:0% +x is less than this is what we want to +find + + align:start position:0% +find + + + align:start position:0% +find +right what to find + + align:start position:0% +right what to find + + + align:start position:0% +right what to find +and h such that this thing here is less + + align:start position:0% +and h such that this thing here is less + + + align:start position:0% +and h such that this thing here is less +than 2 - x^2 right this thing here is + + align:start position:0% +than 2 - x^2 right this thing here is + + + align:start position:0% +than 2 - x^2 right this thing here is +now because x^2 is strictly less than + + align:start position:0% +now because x^2 is strictly less than + + + align:start position:0% +now because x^2 is strictly less than +two this is positive right here you can + + align:start position:0% +two this is positive right here you can + + + align:start position:0% +two this is positive right here you can +just factor out an h so you want to find + + align:start position:0% +just factor out an h so you want to find + + + align:start position:0% +just factor out an h so you want to find +so if you factor out an h then you have + + align:start position:0% +so if you factor out an h then you have + + + align:start position:0% +so if you factor out an h then you have +this thing here is less than 2 minus x^2 + + align:start position:0% +this thing here is less than 2 minus x^2 + + + align:start position:0% +this thing here is less than 2 minus x^2 +and this is just saying that you want to + + align:start position:0% +and this is just saying that you want to + + + align:start position:0% +and this is just saying that you want to +find an h so that this thing here is uh + + align:start position:0% +find an h so that this thing here is uh + + + align:start position:0% +find an h so that this thing here is uh +is strictly less than 2 - x^2 / 1 + 2x + + align:start position:0% +is strictly less than 2 - x^2 / 1 + 2x + + + align:start position:0% +is strictly less than 2 - x^2 / 1 + 2x +is positive. + + align:start position:0% +is positive. + + + align:start position:0% +is positive. +So this thing here is positive. + + align:start position:0% +So this thing here is positive. + + + align:start position:0% +So this thing here is positive. +So this and this here is also positive. + + align:start position:0% +So this and this here is also positive. + + + align:start position:0% +So this and this here is also positive. +So this here is a positive number. So + + align:start position:0% +So this here is a positive number. So + + + align:start position:0% +So this here is a positive number. So +you can definitely find some x with this + + align:start position:0% +you can definitely find some x with this + + + align:start position:0% +you can definitely find some x with this +property, right? And then you see that + + align:start position:0% +property, right? And then you see that + + + align:start position:0% +property, right? And then you see that +so this means that this x + h would also + + align:start position:0% +so this means that this x + h would also + + + align:start position:0% +so this means that this x + h would also +be in the set a contradicting that x was + + align:start position:0% +be in the set a contradicting that x was + + + align:start position:0% +be in the set a contradicting that x was +an upper bound. + + align:start position:0% +an upper bound. + + + align:start position:0% +an upper bound. +Okay. + + align:start position:0% + + + + align:start position:0% + +Now + + align:start position:0% +Now + + + align:start position:0% +Now +um okay so now a corner we immediately + + align:start position:0% +um okay so now a corner we immediately + + + align:start position:0% +um okay so now a corner we immediately +get of this is that the + + align:start position:0% +get of this is that the + + + align:start position:0% +get of this is that the +that the rationals + + align:start position:0% +that the rationals + + + align:start position:0% +that the rationals +is not complete + + align:start position:0% +is not complete + + + align:start position:0% +is not complete +right so + + align:start position:0% +right so + + + align:start position:0% +right so +so we get the following corner + + align:start position:0% + + + + align:start position:0% + +the rational number is not complete + + align:start position:0% +the rational number is not complete + + + align:start position:0% +the rational number is not complete +Right? + + align:start position:0% + + + + align:start position:0% + +And this is just because so the proof of + + align:start position:0% +And this is just because so the proof of + + + align:start position:0% +And this is just because so the proof of +that is that we have already so um if + + align:start position:0% +that is that we have already so um if + + + align:start position:0% +that is that we have already so um if +we're looking at the the this this + + align:start position:0% + + + + align:start position:0% + +at a field that is complete and contains + + align:start position:0% +at a field that is complete and contains + + + align:start position:0% +at a field that is complete and contains +a rational then we know that square root + + align:start position:0% +a rational then we know that square root + + + align:start position:0% +a rational then we know that square root +of two is in that field. Right? So we + + align:start position:0% +of two is in that field. Right? So we + + + align:start position:0% +of two is in that field. Right? So we +just proven + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +if f + + align:start position:0% +if f + + + align:start position:0% +if f +is a complete field + + align:start position:0% + + + + align:start position:0% + +containing the rationals + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% +then + + + align:start position:0% +then +square root of two + + align:start position:0% +square root of two + + + align:start position:0% +square root of two +is in that field. + + align:start position:0% +is in that field. + + + align:start position:0% +is in that field. +Right? But we know that square root of + + align:start position:0% +Right? But we know that square root of + + + align:start position:0% +Right? But we know that square root of +we have also proven we've also shown + + align:start position:0% +we have also proven we've also shown + + + align:start position:0% +we have also proven we've also shown +we have also shown + + align:start position:0% + + + + align:start position:0% + +also shown + + align:start position:0% + + + + align:start position:0% + +that square root of two is not a + + align:start position:0% +that square root of two is not a + + + align:start position:0% +that square root of two is not a +rational number. Right? So, so the + + align:start position:0% +rational number. Right? So, so the + + + align:start position:0% +rational number. Right? So, so the +rational, so if you're looking, so the + + align:start position:0% +rational, so if you're looking, so the + + + align:start position:0% +rational, so if you're looking, so the +rational in itself is not complete. + + align:start position:0% + + + + align:start position:0% + +Um, + + align:start position:0% +Um, + + + align:start position:0% +Um, +okay. + + align:start position:0% +okay. + + + align:start position:0% +okay. +Now, the next thing I want to do is + + align:start position:0% +Now, the next thing I want to do is + + + align:start position:0% +Now, the next thing I want to do is +prove what's called the Archimedian + + align:start position:0% +prove what's called the Archimedian + + + align:start position:0% +prove what's called the Archimedian +properties. The Archimedian property. + + align:start position:0% +properties. The Archimedian property. + + + align:start position:0% +properties. The Archimedian property. +And so, this is actually something that + + align:start position:0% +And so, this is actually something that + + + align:start position:0% +And so, this is actually something that +was sort of used here. Um, sort of used + + align:start position:0% +was sort of used here. Um, sort of used + + + align:start position:0% +was sort of used here. Um, sort of used +it I know it already, but let me just + + align:start position:0% +it I know it already, but let me just + + + align:start position:0% +it I know it already, but let me just +prove it + + align:start position:0% + + + + align:start position:0% + +because + + align:start position:0% + + + + align:start position:0% + +so the Arimedian property. + + align:start position:0% + + + + align:start position:0% + +So this is the following + + align:start position:0% + + + + align:start position:0% + +that um that for all + + align:start position:0% + + + + align:start position:0% + +for all + + align:start position:0% +for all + + + align:start position:0% +for all +real numbers every time you take a real + + align:start position:0% +real numbers every time you take a real + + + align:start position:0% +real numbers every time you take a real +number + + align:start position:0% +number + + + align:start position:0% +number +then there exist + + align:start position:0% + + + + align:start position:0% + +uh an integer + + align:start position:0% + + + + align:start position:0% + +even a natural number + + align:start position:0% + + + + align:start position:0% + +in such that + + align:start position:0% +in such that + + + align:start position:0% +in such that +uh n here is bigger equal is bigger than + + align:start position:0% +uh n here is bigger equal is bigger than + + + align:start position:0% +uh n here is bigger equal is bigger than +uh than than x. Okay, this seems like a + + align:start position:0% +uh than than x. Okay, this seems like a + + + align:start position:0% +uh than than x. Okay, this seems like a +kind of trivial fact, right? But let me + + align:start position:0% +kind of trivial fact, right? But let me + + + align:start position:0% +kind of trivial fact, right? But let me +try to actually prove it uh in a + + align:start position:0% +try to actually prove it uh in a + + + align:start position:0% +try to actually prove it uh in a +rigorous way. So this is what's called + + align:start position:0% +rigorous way. So this is what's called + + + align:start position:0% +rigorous way. So this is what's called +the Archimedian property. + + align:start position:0% + + + + align:start position:0% + +And so again + + align:start position:0% +And so again + + + align:start position:0% +And so again +we prove this by contradiction. + + align:start position:0% + + + + align:start position:0% + +So suppose not + + align:start position:0% + + + + align:start position:0% + +so if there existed an X. So that you + + align:start position:0% +so if there existed an X. So that you + + + align:start position:0% +so if there existed an X. So that you +did not have this. Well then so suppose + + align:start position:0% +did not have this. Well then so suppose + + + align:start position:0% +did not have this. Well then so suppose +not + + align:start position:0% +not + + + align:start position:0% +not +then + + align:start position:0% +then + + + align:start position:0% +then +there. So the negation of that statement + + align:start position:0% +there. So the negation of that statement + + + align:start position:0% +there. So the negation of that statement +is that then there exist + + align:start position:0% + + + + align:start position:0% + +an x such that + + align:start position:0% +an x such that + + + align:start position:0% +an x such that +for all + + align:start position:0% +for all + + + align:start position:0% +for all +natural numbers for all + + align:start position:0% + + + + align:start position:0% + +you have that n here is lesser equal to + + align:start position:0% +you have that n here is lesser equal to + + + align:start position:0% +you have that n here is lesser equal to +x + + align:start position:0% +x + + + align:start position:0% +x +right it's actually yeah it's lesser + + align:start position:0% +right it's actually yeah it's lesser + + + align:start position:0% +right it's actually yeah it's lesser +equal to x right because this is the + + align:start position:0% +equal to x right because this is the + + + align:start position:0% +equal to x right because this is the +negation + + align:start position:0% +negation + + + align:start position:0% +negation +of that. + + align:start position:0% +of that. + + + align:start position:0% +of that. +But this means that + + align:start position:0% +But this means that + + + align:start position:0% +But this means that +this means + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% +that + + + align:start position:0% +that +uh x here is an upper bound. + + align:start position:0% + + + + align:start position:0% + +Okay. And so now you could so now so so + + align:start position:0% +Okay. And so now you could so now so so + + + align:start position:0% +Okay. And so now you could so now so so +then you could take so assume + + align:start position:0% +then you could take so assume + + + align:start position:0% +then you could take so assume +So you could replace by this by the + + align:start position:0% +So you could replace by this by the + + + align:start position:0% +So you could replace by this by the +least upper bound property. + + align:start position:0% +least upper bound property. + + + align:start position:0% +least upper bound property. +So this means so it's upper bound. So in + + align:start position:0% +So this means so it's upper bound. So in + + + align:start position:0% +So this means so it's upper bound. So in +particular + + align:start position:0% + + + + align:start position:0% + +the natural number is a bounded set. + + align:start position:0% +the natural number is a bounded set. + + + align:start position:0% +the natural number is a bounded set. +Bounded subset bounded subset + + align:start position:0% + + + + align:start position:0% + +of of the reals. Right? + + align:start position:0% +of of the reals. Right? + + + align:start position:0% +of of the reals. Right? +And then you could take so then we let + + align:start position:0% +And then you could take so then we let + + + align:start position:0% +And then you could take so then we let +then + + align:start position:0% +then + + + align:start position:0% +then +let's let's say y + + align:start position:0% +let's let's say y + + + align:start position:0% +let's let's say y +be + + align:start position:0% +be + + + align:start position:0% +be +the least upper bound + + align:start position:0% + + + + align:start position:0% + +uh of the natural numbers. + + align:start position:0% +uh of the natural numbers. + + + align:start position:0% +uh of the natural numbers. +If it really was if the natural numbers + + align:start position:0% +If it really was if the natural numbers + + + align:start position:0% +If it really was if the natural numbers +was really bounded because it's a subset + + align:start position:0% +was really bounded because it's a subset + + + align:start position:0% +was really bounded because it's a subset +of the real we could now take the least + + align:start position:0% +of the real we could now take the least + + + align:start position:0% +of the real we could now take the least +upper bound. + + align:start position:0% +upper bound. + + + align:start position:0% +upper bound. +Okay. So now what we have is that we + + align:start position:0% +Okay. So now what we have is that we + + + align:start position:0% +Okay. So now what we have is that we +have that + + align:start position:0% +have that + + + align:start position:0% +have that +for any natural number. So for all + + align:start position:0% + + + + align:start position:0% + +we have that n here is lesser equal to + + align:start position:0% +we have that n here is lesser equal to + + + align:start position:0% +we have that n here is lesser equal to +y. + + align:start position:0% +y. + + + align:start position:0% +y. +But whenever you take a natural number + + align:start position:0% +But whenever you take a natural number + + + align:start position:0% +But whenever you take a natural number +then add one to that nual number. So we + + align:start position:0% +then add one to that nual number. So we + + + align:start position:0% +then add one to that nual number. So we +also have we would also have that + + align:start position:0% + + + + align:start position:0% + +right. So so y is not just a upper bound + + align:start position:0% +right. So so y is not just a upper bound + + + align:start position:0% +right. So so y is not just a upper bound +for n but it actually because n plus one + + align:start position:0% +for n but it actually because n plus one + + + align:start position:0% +for n but it actually because n plus one +is also not actual number right. So y + + align:start position:0% +is also not actual number right. So y + + + align:start position:0% +is also not actual number right. So y +here + + align:start position:0% +here + + + align:start position:0% +here +would have to be big or equal to n plus + + align:start position:0% +would have to be big or equal to n plus + + + align:start position:0% +would have to be big or equal to n plus +one also right but this and this now + + align:start position:0% +one also right but this and this now + + + align:start position:0% +one also right but this and this now +hold for all n. So this means that just + + align:start position:0% +hold for all n. So this means that just + + + align:start position:0% +hold for all n. So this means that just +moving the one over on the other side. + + align:start position:0% +moving the one over on the other side. + + + align:start position:0% +moving the one over on the other side. +So hence + + align:start position:0% +So hence + + + align:start position:0% +So hence +n here is less than y minus one. Right? + + align:start position:0% +n here is less than y minus one. Right? + + + align:start position:0% +n here is less than y minus one. Right? +So this but this here say that so mean + + align:start position:0% +So this but this here say that so mean + + + align:start position:0% +So this but this here say that so mean +this means + + align:start position:0% +this means + + + align:start position:0% +this means +this mean + + align:start position:0% +this mean + + + align:start position:0% +this mean +that y - + + align:start position:0% +that y - + + + align:start position:0% +that y - +1 is also an upper bound + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +and that that and that this is a + + align:start position:0% +and that that and that this is a + + + align:start position:0% +and that that and that this is a +contradiction right so this contradict + + align:start position:0% +contradiction right so this contradict + + + align:start position:0% +contradiction right so this contradict +that + + align:start position:0% +that + + + align:start position:0% +that +uh that why was the least up about + + align:start position:0% + + + + align:start position:0% + +okay and that's the property + + align:start position:0% +okay and that's the property + + + align:start position:0% +okay and that's the property +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now uh I want to give uh one application + + align:start position:0% +now uh I want to give uh one application + + + align:start position:0% +now uh I want to give uh one application +of this + + align:start position:0% +of this + + + align:start position:0% +of this +uh and so this is the following + + align:start position:0% + + + + align:start position:0% + +What the hell? + + align:start position:0% + + + + align:start position:0% + +So, so we now uh I now want to prove the + + align:start position:0% +So, so we now uh I now want to prove the + + + align:start position:0% +So, so we now uh I now want to prove the +following corner of the Archimedian P. + + align:start position:0% + + + + align:start position:0% + +And the corner is that uh whenever you + + align:start position:0% +And the corner is that uh whenever you + + + align:start position:0% +And the corner is that uh whenever you +have two real numbers x and y. + + align:start position:0% +have two real numbers x and y. + + + align:start position:0% +have two real numbers x and y. +So these are are real numbers and x here + + align:start position:0% +So these are are real numbers and x here + + + align:start position:0% +So these are are real numbers and x here +is less than y. Then the claim is that + + align:start position:0% +is less than y. Then the claim is that + + + align:start position:0% +is less than y. Then the claim is that +then there exist + + align:start position:0% + + + + align:start position:0% + +a rational number + + align:start position:0% + + + + align:start position:0% + +m over uh n + + align:start position:0% +m over uh n + + + align:start position:0% +m over uh n +with + + align:start position:0% +with + + + align:start position:0% +with +uh with a property that is between these + + align:start position:0% +uh with a property that is between these + + + align:start position:0% +uh with a property that is between these +two. so that that x is less than m / n + + align:start position:0% +two. so that that x is less than m / n + + + align:start position:0% +two. so that that x is less than m / n +and less than one. Okay, that's what I + + align:start position:0% +and less than one. Okay, that's what I + + + align:start position:0% +and less than one. Okay, that's what I +want to prove using the archimedian + + align:start position:0% +want to prove using the archimedian + + + align:start position:0% +want to prove using the archimedian +property. + + align:start position:0% + + + + align:start position:0% + +And so so to prove that so to prove that + + align:start position:0% +And so so to prove that so to prove that + + + align:start position:0% +And so so to prove that so to prove that +um + + align:start position:0% + + + + align:start position:0% + +so to prove that I look at at better + + align:start position:0% +so to prove that I look at at better + + + align:start position:0% +so to prove that I look at at better +saying better is y - x + + align:start position:0% + + + + align:start position:0% + +and I'm looking at uh so y - x because y + + align:start position:0% +and I'm looking at uh so y - x because y + + + align:start position:0% +and I'm looking at uh so y - x because y +is bigger than x this is positive + + align:start position:0% +is bigger than x this is positive + + + align:start position:0% +is bigger than x this is positive +And I can now look at one over beta. So + + align:start position:0% +And I can now look at one over beta. So + + + align:start position:0% +And I can now look at one over beta. So +one over beta is some positive real + + align:start position:0% +one over beta is some positive real + + + align:start position:0% +one over beta is some positive real +number. + + align:start position:0% +number. + + + align:start position:0% +number. +And now the Archimedian property say + + align:start position:0% +And now the Archimedian property say + + + align:start position:0% +And now the Archimedian property say +that. So by the archimedian property + + align:start position:0% + + + + align:start position:0% + +the Archimedian property there exist + + align:start position:0% + + + + align:start position:0% + +there exist + + align:start position:0% + + + + align:start position:0% + +um n a natural number + + align:start position:0% +um n a natural number + + + align:start position:0% +um n a natural number +such that + + align:start position:0% + + + + align:start position:0% + +n is bigger than + + align:start position:0% +n is bigger than + + + align:start position:0% +n is bigger than +one over b, + + align:start position:0% +one over b, + + + align:start position:0% +one over b, +right? That's the armedian property. It + + align:start position:0% +right? That's the armedian property. It + + + align:start position:0% +right? That's the armedian property. It +gives us this n. + + align:start position:0% +gives us this n. + + + align:start position:0% +gives us this n. +But now, of course, if that's the case, + + align:start position:0% +But now, of course, if that's the case, + + + align:start position:0% +But now, of course, if that's the case, +this implies + + align:start position:0% +this implies + + + align:start position:0% +this implies +you just take one over on both sides and + + align:start position:0% +you just take one over on both sides and + + + align:start position:0% +you just take one over on both sides and +that reverses the inequality. This + + align:start position:0% +that reverses the inequality. This + + + align:start position:0% +that reverses the inequality. This +implies that 1 / n is smaller than + + align:start position:0% +implies that 1 / n is smaller than + + + align:start position:0% +implies that 1 / n is smaller than +better. + + align:start position:0% +better. + + + align:start position:0% +better. +When we get that + + align:start position:0% + + + + align:start position:0% + +and so now we are just looking at so now + + align:start position:0% +and so now we are just looking at so now + + + align:start position:0% +and so now we are just looking at so now +we look at + + align:start position:0% + + + + align:start position:0% + +so now that's this sort of defined as + + align:start position:0% +so now that's this sort of defined as + + + align:start position:0% +so now that's this sort of defined as +step size to some extent. So we're + + align:start position:0% +step size to some extent. So we're + + + align:start position:0% +step size to some extent. So we're +looking at so we have here + + align:start position:0% +looking at so we have here + + + align:start position:0% +looking at so we have here +X and we have here Y + + align:start position:0% +X and we have here Y + + + align:start position:0% +X and we have here Y +and beta bet better is really this + + align:start position:0% +and beta bet better is really this + + + align:start position:0% +and beta bet better is really this +distance here this here is better + + align:start position:0% +distance here this here is better + + + align:start position:0% +distance here this here is better +distance between the two + + align:start position:0% +distance between the two + + + align:start position:0% +distance between the two +and uh n here is uh we now have seen + + align:start position:0% +and uh n here is uh we now have seen + + + align:start position:0% +and uh n here is uh we now have seen +that there's a n so that when you're + + align:start position:0% +that there's a n so that when you're + + + align:start position:0% +that there's a n so that when you're +looking at 1 / n then then uh so one / n + + align:start position:0% +looking at 1 / n then then uh so one / n + + + align:start position:0% +looking at 1 / n then then uh so one / n +here is smaller then better something + + align:start position:0% +here is smaller then better something + + + align:start position:0% +here is smaller then better something +positive and smaller and better. + + align:start position:0% +positive and smaller and better. + + + align:start position:0% +positive and smaller and better. +So now you're looking at the at the m So + + align:start position:0% +So now you're looking at the at the m So + + + align:start position:0% +So now you're looking at the at the m So +now you're looking at So now look at the + + align:start position:0% + + + + align:start position:0% + +at the integers + + align:start position:0% +at the integers + + + align:start position:0% +at the integers +so that uh m + + align:start position:0% +so that uh m + + + align:start position:0% +so that uh m +minus one + + align:start position:0% +minus one + + + align:start position:0% +minus one +so that m minus one uh is + + align:start position:0% +so that m minus one uh is + + + align:start position:0% +so that m minus one uh is +uh uh is less than x * + + align:start position:0% +uh uh is less than x * + + + align:start position:0% +uh uh is less than x * +So suppose you're looking at the right + + align:start position:0% +So suppose you're looking at the right + + + align:start position:0% +So suppose you're looking at the right +this thing here right if you take x * n + + align:start position:0% +this thing here right if you take x * n + + + align:start position:0% +this thing here right if you take x * n +this is an integer so there's definely + + align:start position:0% +this is an integer so there's definely + + + align:start position:0% +this is an integer so there's definely +some m with this property and you can + + align:start position:0% +some m with this property and you can + + + align:start position:0% +some m with this property and you can +find the biggest so look at + + align:start position:0% +find the biggest so look at + + + align:start position:0% +find the biggest so look at +m with this property and let's and let's + + align:start position:0% +m with this property and let's and let's + + + align:start position:0% +m with this property and let's and let's +denote n + + align:start position:0% +denote n + + + align:start position:0% +denote n +and choose + + align:start position:0% + + + + align:start position:0% + +the largest + + align:start position:0% +the largest + + + align:start position:0% +the largest +the largest + + align:start position:0% +the largest + + + align:start position:0% +the largest +such m. + + align:start position:0% + + + + align:start position:0% + +So if you choose the largest such m then + + align:start position:0% +So if you choose the largest such m then + + + align:start position:0% +So if you choose the largest such m then +you see that right so this inequality + + align:start position:0% +you see that right so this inequality + + + align:start position:0% +you see that right so this inequality +here this will just tell you that m -1 + + align:start position:0% +here this will just tell you that m -1 + + + align:start position:0% +here this will just tell you that m -1 +uh over uh over uh n that this is + + align:start position:0% +uh over uh over uh n that this is + + + align:start position:0% +uh over uh over uh n that this is +smaller than x right + + align:start position:0% + + + + align:start position:0% + +but you would also have that because it + + align:start position:0% +but you would also have that because it + + + align:start position:0% +but you would also have that because it +was the largest such m Okay. + + align:start position:0% + + + + align:start position:0% + +Since + + align:start position:0% +Since + + + align:start position:0% +Since +Since M was the largest + + align:start position:0% + + + + align:start position:0% + +such + + align:start position:0% +such + + + align:start position:0% +such +such m then you would have that if you + + align:start position:0% +such m then you would have that if you + + + align:start position:0% +such m then you would have that if you +had m itself in the denominator then it + + align:start position:0% +had m itself in the denominator then it + + + align:start position:0% +had m itself in the denominator then it +wouldn't be smaller than than x. would + + align:start position:0% +wouldn't be smaller than than x. would + + + align:start position:0% +wouldn't be smaller than than x. would +actually be larger equal to x, + + align:start position:0% +actually be larger equal to x, + + + align:start position:0% +actually be larger equal to x, +right? + + align:start position:0% +right? + + + align:start position:0% +right? +And I just want to now prove that this + + align:start position:0% +And I just want to now prove that this + + + align:start position:0% +And I just want to now prove that this +so this here is bigger than x. That's + + align:start position:0% +so this here is bigger than x. That's + + + align:start position:0% +so this here is bigger than x. That's +part of what I needed to prove. I also + + align:start position:0% +part of what I needed to prove. I also + + + align:start position:0% +part of what I needed to prove. I also +wanted to show that it's smaller than y, + + align:start position:0% +wanted to show that it's smaller than y, + + + align:start position:0% +wanted to show that it's smaller than y, +right? + + align:start position:0% + + + + align:start position:0% + +And um and so but if you now add, right? + + align:start position:0% +And um and so but if you now add, right? + + + align:start position:0% +And um and so but if you now add, right? +So now but now the step size. So when + + align:start position:0% +So now but now the step size. So when + + + align:start position:0% +So now but now the step size. So when +you have here here you have x here you + + align:start position:0% +you have here here you have x here you + + + align:start position:0% +you have here here you have x here you +have y + + align:start position:0% +have y + + + align:start position:0% +have y +1 / n 1 / n was smaller than this + + align:start position:0% +1 / n 1 / n was smaller than this + + + align:start position:0% +1 / n 1 / n was smaller than this +distance. So if you are at some point + + align:start position:0% +distance. So if you are at some point + + + align:start position:0% +distance. So if you are at some point +here this is where you are when you are + + align:start position:0% +here this is where you are when you are + + + align:start position:0% +here this is where you are when you are +at m minus one / n then you can't go + + align:start position:0% +at m minus one / n then you can't go + + + align:start position:0% +at m minus one / n then you can't go +further to the right. you you go one + + align:start position:0% +further to the right. you you go one + + + align:start position:0% +further to the right. you you go one +over n uh to the right, but that can't + + align:start position:0% +over n uh to the right, but that can't + + + align:start position:0% +over n uh to the right, but that can't +take you all the way past one, right? So + + align:start position:0% +take you all the way past one, right? So + + + align:start position:0% +take you all the way past one, right? So +that's why if you're looking at at this + + align:start position:0% +that's why if you're looking at at this + + + align:start position:0% +that's why if you're looking at at this +number here, this here must be smaller + + align:start position:0% +number here, this here must be smaller + + + align:start position:0% +number here, this here must be smaller +than y. + + align:start position:0% +than y. + + + align:start position:0% +than y. +Okay? And if I had just chosen m so that + + align:start position:0% +Okay? And if I had just chosen m so that + + + align:start position:0% +Okay? And if I had just chosen m so that +this here was smaller equal to that, + + align:start position:0% +this here was smaller equal to that, + + + align:start position:0% +this here was smaller equal to that, +then I would get this point. + + align:start position:0% +then I would get this point. + + + align:start position:0% +then I would get this point. +Okay? So that's how + + align:start position:0% +Okay? So that's how + + + align:start position:0% +Okay? So that's how +that's a corary of the Archimedian + + align:start position:0% +that's a corary of the Archimedian + + + align:start position:0% +that's a corary of the Archimedian +property. I think there would be + + align:start position:0% +property. I think there would be + + + align:start position:0% +property. I think there would be +something like something along these + + align:start position:0% +something like something along these + + + align:start position:0% +something like something along these +lines on the homework. And again, I will + + align:start position:0% +lines on the homework. And again, I will + + + align:start position:0% +lines on the homework. And again, I will +uh I'm just waiting for the the office + + align:start position:0% +uh I'm just waiting for the the office + + + align:start position:0% +uh I'm just waiting for the the office +hour. I know that the office hour there + + align:start position:0% +hour. I know that the office hour there + + + align:start position:0% +hour. I know that the office hour there +will at least be four office hours next + + align:start position:0% +will at least be four office hours next + + + align:start position:0% +will at least be four office hours next +week. Monday + + align:start position:0% +week. Monday + + + align:start position:0% +week. Monday +uh on Mondays and Wednesday the office + + align:start position:0% +uh on Mondays and Wednesday the office + + + align:start position:0% +uh on Mondays and Wednesday the office +hours would be there will be office + + align:start position:0% +hours would be there will be office + + + align:start position:0% +hours would be there will be office +hours from 5 to 6 on Monday and + + align:start position:0% +hours from 5 to 6 on Monday and + + + align:start position:0% +hours from 5 to 6 on Monday and +Wednesday. uh um and and the other days + + align:start position:0% +Wednesday. uh um and and the other days + + + align:start position:0% +Wednesday. uh um and and the other days +it would be 1:15 to uh 2:15. But you can + + align:start position:0% +it would be 1:15 to uh 2:15. But you can + + + align:start position:0% +it would be 1:15 to uh 2:15. But you can +check the the the the time is actually + + align:start position:0% +check the the the the time is actually + + + align:start position:0% +check the the the the time is actually +already uh posted. Uh the room number I + + align:start position:0% +already uh posted. Uh the room number I + + + align:start position:0% +already uh posted. Uh the room number I +hope to have that today. Once I have + + align:start position:0% +hope to have that today. Once I have + + + align:start position:0% +hope to have that today. Once I have +that then I will also assign the + + align:start position:0% +that then I will also assign the + + + align:start position:0% +that then I will also assign the +homework probably today or maybe more + + align:start position:0% +homework probably today or maybe more + + + align:start position:0% +homework probably today or maybe more +likely tomorrow the homework but it + + align:start position:0% +likely tomorrow the homework but it + + + align:start position:0% +likely tomorrow the homework but it +won't be due next week just the + + align:start position:0% +won't be due next week just the + + + align:start position:0% +won't be due next week just the +following week. + + align:start position:0% +following week. + + + align:start position:0% +following week. +Any + + align:start position:0% +Any + + + align:start position:0% +Any +questions? + + align:start position:0% + + + + align:start position:0% + +And of course, I very much encourage you + + align:start position:0% +And of course, I very much encourage you + + + align:start position:0% +And of course, I very much encourage you +to go to to the office hours. Um, and um + + align:start position:0% +to go to to the office hours. Um, and um + + + align:start position:0% +to go to to the office hours. Um, and um +yeah. + + align:start position:0% +yeah. + + + align:start position:0% +yeah. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Sorry. + + align:start position:0% + + + + align:start position:0% + +>> Yeah. + + align:start position:0% + + + + align:start position:0% + +>> Right. So remember that the minus1 was + + align:start position:0% +>> Right. So remember that the minus1 was + + + align:start position:0% +>> Right. So remember that the minus1 was +this element that you had when you had + + align:start position:0% +this element that you had when you had + + + align:start position:0% +this element that you had when you had +uh remember that a field had the true + + align:start position:0% +uh remember that a field had the true + + + align:start position:0% +uh remember that a field had the true +operation plus and multiplication right + + align:start position:0% +operation plus and multiplication right + + + align:start position:0% +operation plus and multiplication right +and and for each of these that had five + + align:start position:0% +and and for each of these that had five + + + align:start position:0% +and and for each of these that had five +property they were sort of they were + + align:start position:0% +property they were sort of they were + + + align:start position:0% +property they were sort of they were +sort of + + align:start position:0% +sort of + + + align:start position:0% +sort of +almost the same property there was one + + align:start position:0% +almost the same property there was one + + + align:start position:0% +almost the same property there was one +exception about that zero didn't have a + + align:start position:0% +exception about that zero didn't have a + + + align:start position:0% +exception about that zero didn't have a +inverse right for multiplication but + + align:start position:0% +inverse right for multiplication but + + + align:start position:0% +inverse right for multiplication but +minus one is is the right so you one but + + align:start position:0% +minus one is is the right so you one but + + + align:start position:0% +minus one is is the right so you one but +one is the neutral element for + + align:start position:0% +one is the neutral element for + + + align:start position:0% +one is the neutral element for +multiplication + + align:start position:0% +multiplication + + + align:start position:0% +multiplication +right that was how one was defined right + + align:start position:0% +right that was how one was defined right + + + align:start position:0% +right that was how one was defined right +and we prove that that there was a + + align:start position:0% +and we prove that that there was a + + + align:start position:0% +and we prove that that there was a +unique zero right that same argument + + align:start position:0% +unique zero right that same argument + + + align:start position:0% +unique zero right that same argument +would prove that there's a unique one + + align:start position:0% +would prove that there's a unique one + + + align:start position:0% +would prove that there's a unique one +okay so there's just one one so it's a + + align:start position:0% +okay so there's just one one so it's a + + + align:start position:0% +okay so there's just one one so it's a +well- definfined notion and then you can + + align:start position:0% +well- definfined notion and then you can + + + align:start position:0% +well- definfined notion and then you can +look at the inverse element of that with + + align:start position:0% +look at the inverse element of that with + + + align:start position:0% +look at the inverse element of that with +respect to addition that's minus one + + align:start position:0% +respect to addition that's minus one + + + align:start position:0% +respect to addition that's minus one +right + + align:start position:0% +right + + + align:start position:0% +right +Yeah. + + align:start position:0% + + + + align:start position:0% + +>> Yeah. And that's a good question and I + + align:start position:0% +>> Yeah. And that's a good question and I + + + align:start position:0% +>> Yeah. And that's a good question and I +will come back to that next time. And + + align:start position:0% +will come back to that next time. And + + + align:start position:0% +will come back to that next time. And +and it it would seem more logical to + + align:start position:0% +and it it would seem more logical to + + + align:start position:0% +and it it would seem more logical to +define both upper and lower bound. But + + align:start position:0% +define both upper and lower bound. But + + + align:start position:0% +define both upper and lower bound. But +you can look at the complement, + + align:start position:0% +you can look at the complement, + + + align:start position:0% +you can look at the complement, +right? And so if you take a set and + + align:start position:0% +right? And so if you take a set and + + + align:start position:0% +right? And so if you take a set and +you're looking at the complement, then + + align:start position:0% +you're looking at the complement, then + + + align:start position:0% +you're looking at the complement, then +the upper bound for that is the same as + + align:start position:0% +the upper bound for that is the same as + + + align:start position:0% +the upper bound for that is the same as +the lower bound. So that's a kind of + + align:start position:0% +the lower bound. So that's a kind of + + + align:start position:0% +the lower bound. So that's a kind of +sneaky way. That's the reason why we did + + align:start position:0% +sneaky way. That's the reason why we did + + + align:start position:0% +sneaky way. That's the reason why we did +it. I, you know, I I might have done it + + align:start position:0% +it. I, you know, I I might have done it + + + align:start position:0% +it. I, you know, I I might have done it +the other way around, but then it was + + align:start position:0% +the other way around, but then it was + + + align:start position:0% +the other way around, but then it was +kind of a little bit overkill, but I + + align:start position:0% +kind of a little bit overkill, but I + + + align:start position:0% +kind of a little bit overkill, but I +agree. It seemed more logical to define + + align:start position:0% +agree. It seemed more logical to define + + + align:start position:0% +agree. It seemed more logical to define +both things, but it actually is + + align:start position:0% +both things, but it actually is + + + align:start position:0% +both things, but it actually is +contained in this. + + align:start position:0% + + + + align:start position:0% + +Any other questions? + + align:start position:0% +Any other questions? + + + align:start position:0% +Any other questions? +>> Yeah. + + align:start position:0% + + + + align:start position:0% + +I mean so we had so so again u we we saw + + align:start position:0% +I mean so we had so so again u we we saw + + + align:start position:0% +I mean so we had so so again u we we saw +that square root of two is not a + + align:start position:0% +that square root of two is not a + + + align:start position:0% +that square root of two is not a +rational number right and if We're + + align:start position:0% +rational number right and if We're + + + align:start position:0% +rational number right and if We're +looking at all rational numbers. + + align:start position:0% +looking at all rational numbers. + + + align:start position:0% +looking at all rational numbers. +All rational numbers so that the square + + align:start position:0% +All rational numbers so that the square + + + align:start position:0% +All rational numbers so that the square +is less or equal to two. Right? That set + + align:start position:0% +is less or equal to two. Right? That set + + + align:start position:0% +is less or equal to two. Right? That set +does not have a it has an upper bound in + + align:start position:0% +does not have a it has an upper bound in + + + align:start position:0% +does not have a it has an upper bound in +a rational number, but it doesn't have a + + align:start position:0% +a rational number, but it doesn't have a + + + align:start position:0% +a rational number, but it doesn't have a +least upper bound. Right? Right. And + + align:start position:0% +least upper bound. Right? Right. And + + + align:start position:0% +least upper bound. Right? Right. And +that's because we we first prove that + + align:start position:0% +that's because we we first prove that + + + align:start position:0% +that's because we we first prove that +there wasn't a rational number so that + + align:start position:0% +there wasn't a rational number so that + + + align:start position:0% +there wasn't a rational number so that +it it multiplied itself was equal to + + align:start position:0% +it it multiplied itself was equal to + + + align:start position:0% +it it multiplied itself was equal to +two. Right? We proved that. + + align:start position:0% + + + + align:start position:0% + +Yeah, that's right. That's right. That's + + align:start position:0% +Yeah, that's right. That's right. That's + + + align:start position:0% +Yeah, that's right. That's right. That's +right. That's right. That's right. + + align:start position:0% +right. That's right. That's right. + + + align:start position:0% +right. That's right. That's right. +That's right. That's right. So, a field + + align:start position:0% +That's right. That's right. So, a field + + + align:start position:0% +That's right. That's right. So, a field +by it's right. A field is complete means + + align:start position:0% +by it's right. A field is complete means + + + align:start position:0% +by it's right. A field is complete means +that whenever you take a subset of that + + align:start position:0% +that whenever you take a subset of that + + + align:start position:0% +that whenever you take a subset of that +field that is bounded then that subset + + align:start position:0% +field that is bounded then that subset + + + align:start position:0% +field that is bounded then that subset +has to have a least upper bound and but + + align:start position:0% +has to have a least upper bound and but + + + align:start position:0% +has to have a least upper bound and but +any bounds including the least of bounds + + align:start position:0% +any bounds including the least of bounds + + + align:start position:0% +any bounds including the least of bounds +that always have to be in the fields. + + align:start position:0% + + + + align:start position:0% + +Any other questions? + + align:start position:0% +Any other questions? + + + align:start position:0% +Any other questions? +>> Yeah. + + align:start position:0% + + + + align:start position:0% + +smaller than one because + + align:start position:0% + + + + align:start position:0% + +we can do the + + align:start position:0% +we can do the + + + align:start position:0% +we can do the +>> so this is in so so when we when we um + + align:start position:0% +>> so this is in so so when we when we um + + + align:start position:0% +>> so this is in so so when we when we um +so you're saying so + + align:start position:0% +so you're saying so + + + align:start position:0% +so you're saying so +so I just want to make sure I understand + + align:start position:0% +so I just want to make sure I understand + + + align:start position:0% +so I just want to make sure I understand +so in the step two + + align:start position:0% +so in the step two + + + align:start position:0% +so in the step two +we added something and we wanted to + + align:start position:0% +we added something and we wanted to + + + align:start position:0% +we added something and we wanted to +prove that you could add something and + + align:start position:0% +prove that you could add something and + + + align:start position:0% +prove that you could add something and +this is still less than two + + align:start position:0% +this is still less than two + + + align:start position:0% +this is still less than two +And and so I was looking for h between + + align:start position:0% +And and so I was looking for h between + + + align:start position:0% +And and so I was looking for h between +zero and one. + + align:start position:0% +zero and one. + + + align:start position:0% +zero and one. +And so then I I got some equation + + align:start position:0% +And so then I I got some equation + + + align:start position:0% +And so then I I got some equation +somewhere that is probably a raised now, + + align:start position:0% +somewhere that is probably a raised now, + + + align:start position:0% +somewhere that is probably a raised now, +but it just require that h was + + align:start position:0% +but it just require that h was + + + align:start position:0% +but it just require that h was +I mean h have to be positive but it was + + align:start position:0% +I mean h have to be positive but it was + + + align:start position:0% +I mean h have to be positive but it was +less than something and that was + + align:start position:0% + + + + align:start position:0% + +>> right. So, so you you Okay. So, I got I + + align:start position:0% +>> right. So, so you you Okay. So, I got I + + + align:start position:0% +>> right. So, so you you Okay. So, I got I +don't remember what I got here. So, I + + align:start position:0% +don't remember what I got here. So, I + + + align:start position:0% +don't remember what I got here. So, I +think I uh Yeah, you're right. Two. I + + align:start position:0% +think I uh Yeah, you're right. Two. I + + + align:start position:0% +think I uh Yeah, you're right. Two. I +can I guess I can reconstruct it. + + align:start position:0% +can I guess I can reconstruct it. + + + align:start position:0% +can I guess I can reconstruct it. +>> Yeah. So, now I So, so I think so what + + align:start position:0% +>> Yeah. So, now I So, so I think so what + + + align:start position:0% +>> Yeah. So, now I So, so I think so what +you are saying is that so so this thing + + align:start position:0% +you are saying is that so so this thing + + + align:start position:0% +you are saying is that so so this thing +here actually so this thing here is + + align:start position:0% +here actually so this thing here is + + + align:start position:0% +here actually so this thing here is +positive, right? And so you want to + + align:start position:0% +positive, right? And so you want to + + + align:start position:0% +positive, right? And so you want to +choose h so that is smaller than this + + align:start position:0% +choose h so that is smaller than this + + + align:start position:0% +choose h so that is smaller than this +but also this here. So you don't but if + + align:start position:0% +but also this here. So you don't but if + + + align:start position:0% +but also this here. So you don't but if +this is positive then I mean if this is + + align:start position:0% +this is positive then I mean if this is + + + align:start position:0% +this is positive then I mean if this is +500 well uh I mean I'm not going to + + align:start position:0% +500 well uh I mean I'm not going to + + + align:start position:0% +500 well uh I mean I'm not going to +choose 500 because it was supposed to be + + align:start position:0% +choose 500 because it was supposed to be + + + align:start position:0% +choose 500 because it was supposed to be +less than one but I just choose it so + + align:start position:0% +less than one but I just choose it so + + + align:start position:0% +less than one but I just choose it so +that it's less than one and also less + + align:start position:0% +that it's less than one and also less + + + align:start position:0% +that it's less than one and also less +than this positive number. \ No newline at end of file diff --git a/765wa_UWnLY.txt b/765wa_UWnLY.txt new file mode 100644 index 0000000000000000000000000000000000000000..c08b91a05d0f491b2757299fad97737c50cb0a29 --- /dev/null +++ b/765wa_UWnLY.txt @@ -0,0 +1,14888 @@ +align:start position:0% + +so uh I'm really pleased that we're able + + align:start position:0% +so uh I'm really pleased that we're able + + + align:start position:0% +so uh I'm really pleased that we're able +to have our speaker with us today John + + align:start position:0% +to have our speaker with us today John + + + align:start position:0% +to have our speaker with us today John +Goen Center John is the director of one + + align:start position:0% +Goen Center John is the director of one + + + align:start position:0% +Goen Center John is the director of one +of the science + + align:start position:0% +of the science + + + align:start position:0% +of the science +impact centers at Santa Gesa University + + align:start position:0% +impact centers at Santa Gesa University + + + align:start position:0% +impact centers at Santa Gesa University +and his Center is the indigenous + + align:start position:0% +and his Center is the indigenous + + + align:start position:0% +and his Center is the indigenous +Knowledge Center uh for Education hypen + + align:start position:0% +Knowledge Center uh for Education hypen + + + align:start position:0% +Knowledge Center uh for Education hypen +science impact it's part of the USGS + + align:start position:0% +science impact it's part of the USGS + + + align:start position:0% +science impact it's part of the USGS +science impact + + align:start position:0% +science impact + + + align:start position:0% +science impact +uh program and so John will present what + + align:start position:0% +uh program and so John will present what + + + align:start position:0% +uh program and so John will present what +for many of us is probably a different + + align:start position:0% +for many of us is probably a different + + + align:start position:0% +for many of us is probably a different +way of looking at the world so I won't + + align:start position:0% +way of looking at the world so I won't + + + align:start position:0% +way of looking at the world so I won't +take up any more time and and uh let + + align:start position:0% +take up any more time and and uh let + + + align:start position:0% +take up any more time and and uh let +John + + align:start position:0% + + + + align:start position:0% + +presentation you're not I'm + + align:start position:0% + + + + align:start position:0% + +not all right well U okay am I am I + + align:start position:0% + + + + align:start position:0% + +there okay well U personally I first of + + align:start position:0% +there okay well U personally I first of + + + align:start position:0% +there okay well U personally I first of +all I want to thank + + align:start position:0% +all I want to thank + + + align:start position:0% +all I want to thank +everybody for being here uh makes me + + align:start position:0% +everybody for being here uh makes me + + + align:start position:0% +everybody for being here uh makes me +feel very + + align:start position:0% +feel very + + + align:start position:0% +feel very +good even when I had the invitation I + + align:start position:0% +good even when I had the invitation I + + + align:start position:0% +good even when I had the invitation I +was like Wow gee you know I didn't + + align:start position:0% +was like Wow gee you know I didn't + + + align:start position:0% +was like Wow gee you know I didn't +realize what I had spoken about at the + + align:start position:0% +realize what I had spoken about at the + + + align:start position:0% +realize what I had spoken about at the +rest in Virginia already had a science + + align:start position:0% +rest in Virginia already had a science + + + align:start position:0% +rest in Virginia already had a science +impact but no I'm really honored really + + align:start position:0% +impact but no I'm really honored really + + + align:start position:0% +impact but no I'm really honored really +honored in fact uh speaking with some of + + align:start position:0% +honored in fact uh speaking with some of + + + align:start position:0% +honored in fact uh speaking with some of +my colleagues about the opportunity to + + align:start position:0% +my colleagues about the opportunity to + + + align:start position:0% +my colleagues about the opportunity to +uh go to another University and and + + align:start position:0% +uh go to another University and and + + + align:start position:0% +uh go to another University and and +present on behalf of the University + + align:start position:0% +present on behalf of the University + + + align:start position:0% +present on behalf of the University +honors not only me but my + + align:start position:0% +honors not only me but my + + + align:start position:0% +honors not only me but my +colleagues uh so I'm really proud + + align:start position:0% +colleagues uh so I'm really proud + + + align:start position:0% +colleagues uh so I'm really proud +of usually to try to get over a lot of + + align:start position:0% +of usually to try to get over a lot of + + + align:start position:0% +of usually to try to get over a lot of +my nervousness you know I + + align:start position:0% +my nervousness you know I + + + align:start position:0% +my nervousness you know I +uh I always uh look towards a foundation + + align:start position:0% +uh I always uh look towards a foundation + + + align:start position:0% +uh I always uh look towards a foundation +that I have and uh I'm going to ask you + + align:start position:0% +that I have and uh I'm going to ask you + + + align:start position:0% +that I have and uh I'm going to ask you +if you could forgive me to + + align:start position:0% +if you could forgive me to + + + align:start position:0% +if you could forgive me to +uh to say something uh in my own + + align:start position:0% +uh to say something uh in my own + + + align:start position:0% +uh to say something uh in my own +language uh me + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +for + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +y + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +what it is I uh I'm going to talk + + align:start position:0% +what it is I uh I'm going to talk + + + align:start position:0% +what it is I uh I'm going to talk +about comes from my heart uh + + align:start position:0% +about comes from my heart uh + + + align:start position:0% +about comes from my heart uh +in my heart is connected to to a land + + align:start position:0% +in my heart is connected to to a land + + + align:start position:0% +in my heart is connected to to a land +base and and especially my my ancestry + + align:start position:0% +base and and especially my my ancestry + + + align:start position:0% +base and and especially my my ancestry +so I I do invoke the help of my + + align:start position:0% +so I I do invoke the help of my + + + align:start position:0% +so I I do invoke the help of my +ancestors + + align:start position:0% +ancestors + + + align:start position:0% +ancestors +uh sort of acknowledge the higher power + + align:start position:0% +uh sort of acknowledge the higher power + + + align:start position:0% +uh sort of acknowledge the higher power +that overlooks all of us to be here with + + align:start position:0% +that overlooks all of us to be here with + + + align:start position:0% +that overlooks all of us to be here with +us as we talk about some important + + align:start position:0% +us as we talk about some important + + + align:start position:0% +us as we talk about some important +things that come from Indian + + align:start position:0% +things that come from Indian + + + align:start position:0% +things that come from Indian +Country so those are things that we do + + align:start position:0% +Country so those are things that we do + + + align:start position:0% +Country so those are things that we do +at our College if you can believe the + + align:start position:0% +at our College if you can believe the + + + align:start position:0% +at our College if you can believe the +things we anytime we get together we + + align:start position:0% +things we anytime we get together we + + + align:start position:0% +things we anytime we get together we +have an elder get up and + + align:start position:0% +have an elder get up and + + + align:start position:0% +have an elder get up and +pray say something that reminds us that + + align:start position:0% +pray say something that reminds us that + + + align:start position:0% +pray say something that reminds us that +connects us all + + align:start position:0% +connects us all + + + align:start position:0% +connects us all +together so this meeting that we have + + align:start position:0% +together so this meeting that we have + + + align:start position:0% +together so this meeting that we have +here really is a uniting and a + + align:start position:0% +here really is a uniting and a + + + align:start position:0% +here really is a uniting and a +connection and what I bring to you is a + + align:start position:0% +connection and what I bring to you is a + + + align:start position:0% +connection and what I bring to you is a +perspective from uh South + + align:start position:0% +perspective from uh South + + + align:start position:0% +perspective from uh South +Dakota the Indian world where I come + + align:start position:0% +Dakota the Indian world where I come + + + align:start position:0% +Dakota the Indian world where I come +from I know I've had many experiences + + align:start position:0% +from I know I've had many experiences + + + align:start position:0% +from I know I've had many experiences +out there in mainstream America but I I + + align:start position:0% +out there in mainstream America but I I + + + align:start position:0% +out there in mainstream America but I I +have traversed across the country this + + align:start position:0% +have traversed across the country this + + + align:start position:0% +have traversed across the country this +North American continent and and finally + + align:start position:0% +North American continent and and finally + + + align:start position:0% +North American continent and and finally +come home to work at a tribal + + align:start position:0% +come home to work at a tribal + + + align:start position:0% +come home to work at a tribal +College my talk is going to be in three + + align:start position:0% +College my talk is going to be in three + + + align:start position:0% +College my talk is going to be in three +parts first of all I'm going to talk a + + align:start position:0% +parts first of all I'm going to talk a + + + align:start position:0% +parts first of all I'm going to talk a +little bit about our + + align:start position:0% +little bit about our + + + align:start position:0% +little bit about our +University and then I'm going to move + + align:start position:0% +University and then I'm going to move + + + align:start position:0% +University and then I'm going to move +into this little uh program about what I + + align:start position:0% +into this little uh program about what I + + + align:start position:0% +into this little uh program about what I +call another America reminding you me of + + align:start position:0% +call another America reminding you me of + + + align:start position:0% +call another America reminding you me of +what this country used to look like and + + align:start position:0% +what this country used to look like and + + + align:start position:0% +what this country used to look like and +how some people still see it + + align:start position:0% +how some people still see it + + + align:start position:0% +how some people still see it +today and then I'm going to give a talk + + align:start position:0% +today and then I'm going to give a talk + + + align:start position:0% +today and then I'm going to give a talk +about our uh indigenous + + align:start position:0% +about our uh indigenous + + + align:start position:0% +about our uh indigenous +Knowledge Center for education and + + align:start position:0% +Knowledge Center for education and + + + align:start position:0% +Knowledge Center for education and +science impact and U we'll open up for + + align:start position:0% +science impact and U we'll open up for + + + align:start position:0% +science impact and U we'll open up for +some discussions I I was in a class this + + align:start position:0% +some discussions I I was in a class this + + + align:start position:0% +some discussions I I was in a class this +morning and I thought it was very + + align:start position:0% +morning and I thought it was very + + + align:start position:0% +morning and I thought it was very +stimulating for me to be asked questions + + align:start position:0% +stimulating for me to be asked questions + + + align:start position:0% +stimulating for me to be asked questions +so if you think of anything that you + + align:start position:0% +so if you think of anything that you + + + align:start position:0% +so if you think of anything that you +want to ask me it not only helps me it + + align:start position:0% +want to ask me it not only helps me it + + + align:start position:0% +want to ask me it not only helps me it +helps me and I really like to be asked + + align:start position:0% +helps me and I really like to be asked + + + align:start position:0% +helps me and I really like to be asked +questions I think I I do better with + + align:start position:0% + + + + align:start position:0% + +questions also coming to this country I + + align:start position:0% +questions also coming to this country I + + + align:start position:0% +questions also coming to this country I +mean you I I I drove three hours to get + + align:start position:0% +mean you I I I drove three hours to get + + + align:start position:0% +mean you I I I drove three hours to get +to the airport to get over here last + + align:start position:0% +to the airport to get over here last + + + align:start position:0% +to the airport to get over here last +night and but always I remember wherever + + align:start position:0% +night and but always I remember wherever + + + align:start position:0% +night and but always I remember wherever +I + + align:start position:0% +I + + + align:start position:0% +I +go there was indigenous people that + + align:start position:0% +go there was indigenous people that + + + align:start position:0% +go there was indigenous people that +lived here so even that song that I sing + + align:start position:0% +lived here so even that song that I sing + + + align:start position:0% +lived here so even that song that I sing +connects to the spirits of the people + + align:start position:0% +connects to the spirits of the people + + + align:start position:0% +connects to the spirits of the people +that used to live here if you can + + align:start position:0% +that used to live here if you can + + + align:start position:0% +that used to live here if you can +believe it every element of creation all + + align:start position:0% +believe it every element of creation all + + + align:start position:0% +believe it every element of creation all +that embodies some sense of a what I + + align:start position:0% +that embodies some sense of a what I + + + align:start position:0% +that embodies some sense of a what I +call a spirit + + align:start position:0% +call a spirit + + + align:start position:0% +call a spirit +memory so I do know though I draw upon + + align:start position:0% +memory so I do know though I draw upon + + + align:start position:0% +memory so I do know though I draw upon +those grandfather spirits and + + align:start position:0% +those grandfather spirits and + + + align:start position:0% +those grandfather spirits and +grandmother spirits that are around here + + align:start position:0% +grandmother spirits that are around here + + + align:start position:0% +grandmother spirits that are around here +to know that I'm here that I I I'm + + align:start position:0% +to know that I'm here that I I I'm + + + align:start position:0% +to know that I'm here that I I I'm +singing and I want to make a connection + + align:start position:0% +singing and I want to make a connection + + + align:start position:0% +singing and I want to make a connection +in a good way but that's those are the + + align:start position:0% +in a good way but that's those are the + + + align:start position:0% +in a good way but that's those are the +things that we believe in where I come + + align:start position:0% +things that we believe in where I come + + + align:start position:0% +things that we believe in where I come +from and there it is uh our our + + align:start position:0% +from and there it is uh our our + + + align:start position:0% +from and there it is uh our our +logo SES University we we're a buffalo + + align:start position:0% +logo SES University we we're a buffalo + + + align:start position:0% +logo SES University we we're a buffalo +culture so that's very prominent for + + align:start position:0% +culture so that's very prominent for + + + align:start position:0% +culture so that's very prominent for +everything we have involves the + + align:start position:0% +everything we have involves the + + + align:start position:0% +everything we have involves the +Buffalo and a vision of our un + + align:start position:0% +Buffalo and a vision of our un + + + align:start position:0% +Buffalo and a vision of our un +University really comes from gentleman + + align:start position:0% +University really comes from gentleman + + + align:start position:0% +University really comes from gentleman +like this who this man is a a chief two + + align:start position:0% +like this who this man is a a chief two + + + align:start position:0% +like this who this man is a a chief two +strike C geska in itself means spotted + + align:start position:0% +strike C geska in itself means spotted + + + align:start position:0% +strike C geska in itself means spotted +tail and the college is named after a + + align:start position:0% +tail and the college is named after a + + + align:start position:0% +tail and the college is named after a +Visionary Chief spotted tale who was one + + align:start position:0% +Visionary Chief spotted tale who was one + + + align:start position:0% +Visionary Chief spotted tale who was one +of the treaty signers in + + align:start position:0% +of the treaty signers in + + + align:start position:0% +of the treaty signers in +1868 who also had a vision of uh of of + + align:start position:0% +1868 who also had a vision of uh of of + + + align:start position:0% +1868 who also had a vision of uh of of +education for the future but a man like + + align:start position:0% +education for the future but a man like + + + align:start position:0% +education for the future but a man like +this you we we aspire to this leader who + + align:start position:0% +this you we we aspire to this leader who + + + align:start position:0% +this you we we aspire to this leader who +in these kind of drawings these Ledger + + align:start position:0% +in these kind of drawings these Ledger + + + align:start position:0% +in these kind of drawings these Ledger +drawings actually embody these kind of + + align:start position:0% +drawings actually embody these kind of + + + align:start position:0% +drawings actually embody these kind of +uh virtues of leadership + + align:start position:0% + + + + align:start position:0% + +wisdom bravery WKA and generosity and + + align:start position:0% +wisdom bravery WKA and generosity and + + + align:start position:0% +wisdom bravery WKA and generosity and +Waka + + align:start position:0% +Waka + + + align:start position:0% +Waka +fortitude we have those emblazoned into + + align:start position:0% +fortitude we have those emblazoned into + + + align:start position:0% +fortitude we have those emblazoned into +the medicine wheel it really points to + + align:start position:0% +the medicine wheel it really points to + + + align:start position:0% +the medicine wheel it really points to +the four cardinal directions in on our + + align:start position:0% +the four cardinal directions in on our + + + align:start position:0% +the four cardinal directions in on our +Evolution with the buffalo in itself + + align:start position:0% +Evolution with the buffalo in itself + + + align:start position:0% +Evolution with the buffalo in itself +that helped form our + + align:start position:0% +that helped form our + + + align:start position:0% +that helped form our +society so it's men like that that + + align:start position:0% +society so it's men like that that + + + align:start position:0% +society so it's men like that that +really had the vision that fought hard + + align:start position:0% +really had the vision that fought hard + + + align:start position:0% +really had the vision that fought hard +that we looked at them as our ultim + + align:start position:0% +that we looked at them as our ultim + + + align:start position:0% +that we looked at them as our ultim +ultimate Patriots who were fighting the + + align:start position:0% +ultimate Patriots who were fighting the + + + align:start position:0% +ultimate Patriots who were fighting the +federal government as we know it + + align:start position:0% +federal government as we know it + + + align:start position:0% +federal government as we know it +now fighting for our way of life and our + + align:start position:0% +now fighting for our way of life and our + + + align:start position:0% +now fighting for our way of life and our +culture our language our way of life + + align:start position:0% +culture our language our way of life + + + align:start position:0% +culture our language our way of life +well today in a sense we have new kinds + + align:start position:0% +well today in a sense we have new kinds + + + align:start position:0% +well today in a sense we have new kinds +of Warriors our students we look towards + + align:start position:0% +of Warriors our students we look towards + + + align:start position:0% +of Warriors our students we look towards +developing new types of leadership + + align:start position:0% +developing new types of leadership + + + align:start position:0% +developing new types of leadership +looking for the wealth and the welfare + + align:start position:0% +looking for the wealth and the welfare + + + align:start position:0% +looking for the wealth and the welfare +of our Health and Welfare of our people + + align:start position:0% +of our Health and Welfare of our people + + + align:start position:0% +of our Health and Welfare of our people +so strengthening the Sanu lot oate + + align:start position:0% +so strengthening the Sanu lot oate + + + align:start position:0% +so strengthening the Sanu lot oate +through education the Sanu o oate are + + align:start position:0% +through education the Sanu o oate are + + + align:start position:0% +through education the Sanu o oate are +one of seven different types of + + align:start position:0% +one of seven different types of + + + align:start position:0% +one of seven different types of +Lota and the Lota are comprised of a + + align:start position:0% +Lota and the Lota are comprised of a + + + align:start position:0% +Lota and the Lota are comprised of a +division of three different sue people + + align:start position:0% +division of three different sue people + + + align:start position:0% +division of three different sue people +as we're known Lota Dakota nakota we all + + align:start position:0% +as we're known Lota Dakota nakota we all + + + align:start position:0% +as we're known Lota Dakota nakota we all +speak the same language but we're + + align:start position:0% +speak the same language but we're + + + align:start position:0% +speak the same language but we're +differentiated in dialect by n DS and + + align:start position:0% +differentiated in dialect by n DS and + + + align:start position:0% +differentiated in dialect by n DS and +L's + + align:start position:0% +L's + + + align:start position:0% +L's +so we as a Lakota we live on the western + + align:start position:0% +so we as a Lakota we live on the western + + + align:start position:0% +so we as a Lakota we live on the western +half of the Missouri River into the + + align:start position:0% +half of the Missouri River into the + + + align:start position:0% +half of the Missouri River into the +western part of South + + align:start position:0% +western part of South + + + align:start position:0% +western part of South +Dakota and there are seven of us myself + + align:start position:0% +Dakota and there are seven of us myself + + + align:start position:0% +Dakota and there are seven of us myself +I'm in ogalala + + align:start position:0% +I'm in ogalala + + + align:start position:0% +I'm in ogalala +Lakota I'm not Sanu but I have + + align:start position:0% +Lakota I'm not Sanu but I have + + + align:start position:0% +Lakota I'm not Sanu but I have +relationships there so but we're all + + align:start position:0% +relationships there so but we're all + + + align:start position:0% +relationships there so but we're all +interrelated that way but we all speak + + align:start position:0% +interrelated that way but we all speak + + + align:start position:0% +interrelated that way but we all speak +the common + + align:start position:0% +the common + + + align:start position:0% +the common +language so that's kind of a little bit + + align:start position:0% +language so that's kind of a little bit + + + align:start position:0% +language so that's kind of a little bit +of a background on the college itself + + align:start position:0% +of a background on the college itself + + + align:start position:0% +of a background on the college itself +that carries the EMB body of of + + align:start position:0% +that carries the EMB body of of + + + align:start position:0% +that carries the EMB body of of +leadership and and um how we look to the + + align:start position:0% +leadership and and um how we look to the + + + align:start position:0% +leadership and and um how we look to the +future but we really do aspire to these + + align:start position:0% +future but we really do aspire to these + + + align:start position:0% +future but we really do aspire to these +kind of uh uh values and that's + + align:start position:0% +kind of uh uh values and that's + + + align:start position:0% +kind of uh uh values and that's +something I think you're going to see in + + align:start position:0% +something I think you're going to see in + + + align:start position:0% +something I think you're going to see in +in my presentation about how it is that + + align:start position:0% +in my presentation about how it is that + + + align:start position:0% +in my presentation about how it is that +we go forward in looking at the future + + align:start position:0% +we go forward in looking at the future + + + align:start position:0% +we go forward in looking at the future +through education in honoring our + + align:start position:0% +through education in honoring our + + + align:start position:0% +through education in honoring our +ancestry because those people really + + align:start position:0% +ancestry because those people really + + + align:start position:0% +ancestry because those people really +fought hard for us so anything we do we + + align:start position:0% +fought hard for us so anything we do we + + + align:start position:0% +fought hard for us so anything we do we +do in a sense of honoring our ancestors + + align:start position:0% +do in a sense of honoring our ancestors + + + align:start position:0% +do in a sense of honoring our ancestors +and also looking to the future with our + + align:start position:0% +and also looking to the future with our + + + align:start position:0% +and also looking to the future with our +our + + align:start position:0% +our + + + align:start position:0% +our +grandchildren + + align:start position:0% + + + + align:start position:0% + +I went to a uh a summit out in JPL last + + align:start position:0% +I went to a uh a summit out in JPL last + + + align:start position:0% +I went to a uh a summit out in JPL last +summer and I I threw this up there and + + align:start position:0% +summer and I I threw this up there and + + + align:start position:0% +summer and I I threw this up there and +and people couldn't relate to it all the + + align:start position:0% +and people couldn't relate to it all the + + + align:start position:0% +and people couldn't relate to it all the +NASA people but I said I know NASA guys + + align:start position:0% +NASA people but I said I know NASA guys + + + align:start position:0% +NASA people but I said I know NASA guys +I've always seen all your orc charts + + align:start position:0% +I've always seen all your orc charts + + + align:start position:0% +I've always seen all your orc charts +they're very late out there but here's + + align:start position:0% +they're very late out there but here's + + + align:start position:0% +they're very late out there but here's +our orc chart but it's really + + align:start position:0% +our orc chart but it's really + + + align:start position:0% +our orc chart but it's really +interesting our orc chart is is centered + + align:start position:0% +interesting our orc chart is is centered + + + align:start position:0% +interesting our orc chart is is centered +around this idea of + + align:start position:0% +around this idea of + + + align:start position:0% +around this idea of +Wakota and our connections to the + + align:start position:0% +Wakota and our connections to the + + + align:start position:0% +Wakota and our connections to the +ancestral voices in the future + + align:start position:0% +ancestral voices in the future + + + align:start position:0% +ancestral voices in the future +Generations but you can see that + + align:start position:0% +Generations but you can see that + + + align:start position:0% +Generations but you can see that +everything is so intrinsic to one + + align:start position:0% +everything is so intrinsic to one + + + align:start position:0% +everything is so intrinsic to one +another it's connected in many different + + align:start position:0% +another it's connected in many different + + + align:start position:0% +another it's connected in many different +ways and they're all connected to this + + align:start position:0% +ways and they're all connected to this + + + align:start position:0% +ways and they're all connected to this +whole idea of of balance and Harmony so + + align:start position:0% +whole idea of of balance and Harmony so + + + align:start position:0% +whole idea of of balance and Harmony so +it's our our our organization carries + + align:start position:0% +it's our our our organization carries + + + align:start position:0% +it's our our our organization carries +with it a strong ideal of a strive to + + align:start position:0% +with it a strong ideal of a strive to + + + align:start position:0% +with it a strong ideal of a strive to +live in peace and Harmony Wakota in fact + + align:start position:0% +live in peace and Harmony Wakota in fact + + + align:start position:0% +live in peace and Harmony Wakota in fact +that's our word for for + + align:start position:0% +that's our word for for + + + align:start position:0% +that's our word for for +treaty as you know a lot of Native + + align:start position:0% +treaty as you know a lot of Native + + + align:start position:0% +treaty as you know a lot of Native +Americans as you know them today + + align:start position:0% +Americans as you know them today + + + align:start position:0% +Americans as you know them today +historically were in involved in treaty + + align:start position:0% +historically were in involved in treaty + + + align:start position:0% +historically were in involved in treaty +relationships with the federal + + align:start position:0% +relationships with the federal + + + align:start position:0% +relationships with the federal +government and we still + + align:start position:0% +government and we still + + + align:start position:0% +government and we still +are but we had no word for treaty in + + align:start position:0% +are but we had no word for treaty in + + + align:start position:0% +are but we had no word for treaty in +fact our word for treaty was Wakota to + + align:start position:0% +fact our word for treaty was Wakota to + + + align:start position:0% +fact our word for treaty was Wakota to +live in peace and Harmony that's how + + align:start position:0% +live in peace and Harmony that's how + + + align:start position:0% +live in peace and Harmony that's how +that's the concept we thought it was we + + align:start position:0% +that's the concept we thought it was we + + + align:start position:0% +that's the concept we thought it was we +said since learned that it was really + + align:start position:0% +said since learned that it was really + + + align:start position:0% +said since learned that it was really +not that it was more like land sessions + + align:start position:0% +not that it was more like land sessions + + + align:start position:0% +not that it was more like land sessions +we were entering into + + align:start position:0% +we were entering into + + + align:start position:0% +we were entering into +but but you can see that though we do + + align:start position:0% +but but you can see that though we do + + + align:start position:0% +but but you can see that though we do +have an extensive organization in our + + align:start position:0% +have an extensive organization in our + + + align:start position:0% +have an extensive organization in our +University in fact we're still evolving + + align:start position:0% +University in fact we're still evolving + + + align:start position:0% +University in fact we're still evolving +ceska University is uh one of 35 tribal + + align:start position:0% +ceska University is uh one of 35 tribal + + + align:start position:0% +ceska University is uh one of 35 tribal +colleges I don't know if many of you + + align:start position:0% +colleges I don't know if many of you + + + align:start position:0% +colleges I don't know if many of you +really understand and know where all the + + align:start position:0% +really understand and know where all the + + + align:start position:0% +really understand and know where all the +tribal colleges are but you can see the + + align:start position:0% +tribal colleges are but you can see the + + + align:start position:0% +tribal colleges are but you can see the +states where they're primarily located + + align:start position:0% +states where they're primarily located + + + align:start position:0% +states where they're primarily located +in but you'll see this uh eastern half + + align:start position:0% +in but you'll see this uh eastern half + + + align:start position:0% +in but you'll see this uh eastern half +of the United States there really are no + + align:start position:0% +of the United States there really are no + + + align:start position:0% +of the United States there really are no +tribal colleges near you but you can see + + align:start position:0% +tribal colleges near you but you can see + + + align:start position:0% +tribal colleges near you but you can see +everything seems to be west of the + + align:start position:0% +everything seems to be west of the + + + align:start position:0% +everything seems to be west of the +Missouri uh Mississippi + + align:start position:0% +Missouri uh Mississippi + + + align:start position:0% +Missouri uh Mississippi +River and the majority of them are into + + align:start position:0% +River and the majority of them are into + + + align:start position:0% +River and the majority of them are into +the Great + + align:start position:0% +the Great + + + align:start position:0% +the Great +Plains and we are land gr institutions + + align:start position:0% +Plains and we are land gr institutions + + + align:start position:0% +Plains and we are land gr institutions +as well but we we + + align:start position:0% +as well but we we + + + align:start position:0% +as well but we we +uh alog together there there are 34 of + + align:start position:0% +uh alog together there there are 34 of + + + align:start position:0% +uh alog together there there are 34 of +them and then there's one right up here + + align:start position:0% +them and then there's one right up here + + + align:start position:0% +them and then there's one right up here +into Alberta which is also we count as + + align:start position:0% +into Alberta which is also we count as + + + align:start position:0% +into Alberta which is also we count as +well and if you want to know exactly + + align:start position:0% +well and if you want to know exactly + + + align:start position:0% +well and if you want to know exactly +where they are their names of them + + align:start position:0% +where they are their names of them + + + align:start position:0% +where they are their names of them +here's a little website you can go to + + align:start position:0% +here's a little website you can go to + + + align:start position:0% +here's a little website you can go to +and you can get the names and addresses + + align:start position:0% +and you can get the names and addresses + + + align:start position:0% +and you can get the names and addresses +of all the tribal colleges + + align:start position:0% +of all the tribal colleges + + + align:start position:0% +of all the tribal colleges +there the tribal colleges uh were + + align:start position:0% +there the tribal colleges uh were + + + align:start position:0% +there the tribal colleges uh were +started about 30 years ago + + align:start position:0% + + + + align:start position:0% + +1974 there was an authority called uh + + align:start position:0% +1974 there was an authority called uh + + + align:start position:0% +1974 there was an authority called uh +self-governance and education assistant + + align:start position:0% +self-governance and education assistant + + + align:start position:0% +self-governance and education assistant +act that sort of opened the door with a + + align:start position:0% +act that sort of opened the door with a + + + align:start position:0% +act that sort of opened the door with a +lot of funding for uh for tribes to + + align:start position:0% +lot of funding for uh for tribes to + + + align:start position:0% +lot of funding for uh for tribes to +start their own tribal colleges so this + + align:start position:0% +start their own tribal colleges so this + + + align:start position:0% +start their own tribal colleges so this +is where C gleska uh got its start + + align:start position:0% +is where C gleska uh got its start + + + align:start position:0% +is where C gleska uh got its start +financially from some of the + + align:start position:0% +financially from some of the + + + align:start position:0% +financially from some of the +funding by that Authority for for + + align:start position:0% +funding by that Authority for for + + + align:start position:0% +funding by that Authority for for +Education as well as other tribal + + align:start position:0% +Education as well as other tribal + + + align:start position:0% +Education as well as other tribal +colleges but we are one of the oldest in + + align:start position:0% +colleges but we are one of the oldest in + + + align:start position:0% +colleges but we are one of the oldest in +fact we are the only + + align:start position:0% +fact we are the only + + + align:start position:0% +fact we are the only +University everybody else are just refer + + align:start position:0% +University everybody else are just refer + + + align:start position:0% +University everybody else are just refer +to themselves as College as four-year uh + + align:start position:0% +to themselves as College as four-year uh + + + align:start position:0% +to themselves as College as four-year uh +Bachelor granting institutions + + align:start position:0% +Bachelor granting institutions + + + align:start position:0% +Bachelor granting institutions +and and some of them are still two-year + + align:start position:0% +and and some of them are still two-year + + + align:start position:0% +and and some of them are still two-year +colleges but many of them are still in + + align:start position:0% +colleges but many of them are still in + + + align:start position:0% +colleges but many of them are still in +evolution of as education institutions + + align:start position:0% +evolution of as education institutions + + + align:start position:0% +evolution of as education institutions +that are serving their their tribal + + align:start position:0% +that are serving their their tribal + + + align:start position:0% +that are serving their their tribal +population and maybe even some of the + + align:start position:0% +population and maybe even some of the + + + align:start position:0% +population and maybe even some of the +rural communities around + + align:start position:0% +rural communities around + + + align:start position:0% +rural communities around +them but it is quite a movement because + + align:start position:0% +them but it is quite a movement because + + + align:start position:0% +them but it is quite a movement because +tribal colleges are much different than + + align:start position:0% +tribal colleges are much different than + + + align:start position:0% +tribal colleges are much different than +mainstream uh education institutions + + align:start position:0% +mainstream uh education institutions + + + align:start position:0% +mainstream uh education institutions +they they are charged with cultural + + align:start position:0% +they they are charged with cultural + + + align:start position:0% +they they are charged with cultural +preservation language + + align:start position:0% +preservation language + + + align:start position:0% +preservation language +preservation so consequently at our + + align:start position:0% +preservation so consequently at our + + + align:start position:0% +preservation so consequently at our +University we're very strong in our + + align:start position:0% +University we're very strong in our + + + align:start position:0% +University we're very strong in our +Lakota studies so even you today if you + + align:start position:0% +Lakota studies so even you today if you + + + align:start position:0% +Lakota studies so even you today if you +want to go out and get a degree in it's + + align:start position:0% +want to go out and get a degree in it's + + + align:start position:0% +want to go out and get a degree in it's +the uh Lota language or Lakota studies + + align:start position:0% +the uh Lota language or Lakota studies + + + align:start position:0% +the uh Lota language or Lakota studies +you can come there and other colleges + + align:start position:0% +you can come there and other colleges + + + align:start position:0% +you can come there and other colleges +have the same kind of programs involving + + align:start position:0% +have the same kind of programs involving + + + align:start position:0% +have the same kind of programs involving +cultural + + align:start position:0% +cultural + + + align:start position:0% +cultural +preservation but we also are charged + + align:start position:0% +preservation but we also are charged + + + align:start position:0% +preservation but we also are charged +with the future by educating our future + + align:start position:0% +with the future by educating our future + + + align:start position:0% +with the future by educating our future +leaders and that has to do with all the + + align:start position:0% +leaders and that has to do with all the + + + align:start position:0% +leaders and that has to do with all the +tribal colleges that you see there much + + align:start position:0% +tribal colleges that you see there much + + + align:start position:0% +tribal colleges that you see there much +more different they're really tied to + + align:start position:0% +more different they're really tied to + + + align:start position:0% +more different they're really tied to +communities they're tied directly to the + + align:start position:0% +communities they're tied directly to the + + + align:start position:0% +communities they're tied directly to the +tribal membership around them and and + + align:start position:0% +tribal membership around them and and + + + align:start position:0% +tribal membership around them and and +why they evolved is because the only + + align:start position:0% +why they evolved is because the only + + + align:start position:0% +why they evolved is because the only +alternative for Education even for me + + align:start position:0% +alternative for Education even for me + + + align:start position:0% +alternative for Education even for me +when I was a young + + align:start position:0% +when I was a young + + + align:start position:0% +when I was a young +man uh I had I was sent to a Catholic + + align:start position:0% +man uh I had I was sent to a Catholic + + + align:start position:0% +man uh I had I was sent to a Catholic +boarding school for 12 years you know + + align:start position:0% +boarding school for 12 years you know + + + align:start position:0% +boarding school for 12 years you know +and that was off the reservation and I + + align:start position:0% +and that was off the reservation and I + + + align:start position:0% +and that was off the reservation and I +had to go to college and I went to + + align:start position:0% +had to go to college and I went to + + + align:start position:0% +had to go to college and I went to +University of Colorado so I was like + + align:start position:0% +University of Colorado so I was like + + + align:start position:0% +University of Colorado so I was like +sent away to so these these colleges + + align:start position:0% +sent away to so these these colleges + + + align:start position:0% +sent away to so these these colleges +sort of provide that alternative for + + align:start position:0% +sort of provide that alternative for + + + align:start position:0% +sort of provide that alternative for +people to stay at home and and be and be + + align:start position:0% +people to stay at home and and be and be + + + align:start position:0% +people to stay at home and and be and be +comfortable because the success rates + + align:start position:0% +comfortable because the success rates + + + align:start position:0% +comfortable because the success rates +for most native people at mainstream + + align:start position:0% +for most native people at mainstream + + + align:start position:0% +for most native people at mainstream +universities has always been disastrous + + align:start position:0% +universities has always been disastrous + + + align:start position:0% +universities has always been disastrous +they + + align:start position:0% +they + + + align:start position:0% +they +just you know it's really hard to leave + + align:start position:0% +just you know it's really hard to leave + + + align:start position:0% +just you know it's really hard to leave +home sometimes you know leave your + + align:start position:0% +home sometimes you know leave your + + + align:start position:0% +home sometimes you know leave your +friends and + + align:start position:0% +friends and + + + align:start position:0% +friends and +family so that's why the college + + align:start position:0% +family so that's why the college + + + align:start position:0% +family so that's why the college +movement is what it is + + align:start position:0% + + + + align:start position:0% + +today I want to kind of move on into to + + align:start position:0% +today I want to kind of move on into to + + + align:start position:0% +today I want to kind of move on into to +another topic + + align:start position:0% +another topic + + + align:start position:0% +another topic +uh I was asked uh last spring to do a + + align:start position:0% +uh I was asked uh last spring to do a + + + align:start position:0% +uh I was asked uh last spring to do a +presentation to the South Dakota State + + align:start position:0% +presentation to the South Dakota State + + + align:start position:0% +presentation to the South Dakota State +uh they call it the space Grant + + align:start position:0% +uh they call it the space Grant + + + align:start position:0% +uh they call it the space Grant +Consortium and uh so iose to the + + align:start position:0% +Consortium and uh so iose to the + + + align:start position:0% +Consortium and uh so iose to the +occasion I said what am I going to tell + + align:start position:0% +occasion I said what am I going to tell + + + align:start position:0% +occasion I said what am I going to tell +people about what we're doing at our + + align:start position:0% +people about what we're doing at our + + + align:start position:0% +people about what we're doing at our +University but so I brought about some + + align:start position:0% +University but so I brought about some + + + align:start position:0% +University but so I brought about some +of my Collective experiences and what + + align:start position:0% +of my Collective experiences and what + + + align:start position:0% +of my Collective experiences and what +I'm charged with doing at the university + + align:start position:0% +I'm charged with doing at the university + + + align:start position:0% +I'm charged with doing at the university +is putting together a curriculum + + align:start position:0% +is putting together a curriculum + + + align:start position:0% +is putting together a curriculum +but but it also brought to me something + + align:start position:0% +but but it also brought to me something + + + align:start position:0% +but but it also brought to me something +I wanted to share with every body else + + align:start position:0% +I wanted to share with every body else + + + align:start position:0% +I wanted to share with every body else +about what I call another + + align:start position:0% +about what I call another + + + align:start position:0% +about what I call another +America and its concepts of the + + align:start position:0% +America and its concepts of the + + + align:start position:0% +America and its concepts of the +Aboriginal worldview and Regional + + align:start position:0% + + + + align:start position:0% + +Landscapes this particular map is going + + align:start position:0% +Landscapes this particular map is going + + + align:start position:0% +Landscapes this particular map is going +to take you back to a certain time what + + align:start position:0% +to take you back to a certain time what + + + align:start position:0% +to take you back to a certain time what +I call the preon cultural + + align:start position:0% +I call the preon cultural + + + align:start position:0% +I call the preon cultural +areas this kind of supersedes anything + + align:start position:0% +areas this kind of supersedes anything + + + align:start position:0% +areas this kind of supersedes anything +that you guys know as your American + + align:start position:0% +that you guys know as your American + + + align:start position:0% +that you guys know as your American +history because really native people we + + align:start position:0% +history because really native people we + + + align:start position:0% +history because really native people we +still see this whole mass of land and in + + align:start position:0% +still see this whole mass of land and in + + + align:start position:0% +still see this whole mass of land and in +fact a lot of the native culture still + + align:start position:0% +fact a lot of the native culture still + + + align:start position:0% +fact a lot of the native culture still +refer to it as Turtle + + align:start position:0% +refer to it as Turtle + + + align:start position:0% +refer to it as Turtle +Island but you can see that it's kind of + + align:start position:0% +Island but you can see that it's kind of + + + align:start position:0% +Island but you can see that it's kind of +geographically divided up into + + align:start position:0% +geographically divided up into + + + align:start position:0% +geographically divided up into +uh I call resource areas all these + + align:start position:0% +uh I call resource areas all these + + + align:start position:0% +uh I call resource areas all these +different geographical areas embody the + + align:start position:0% +different geographical areas embody the + + + align:start position:0% +different geographical areas embody the +resources that have developed the + + align:start position:0% +resources that have developed the + + + align:start position:0% +resources that have developed the +culture in the Great Plains I know a lot + + align:start position:0% +culture in the Great Plains I know a lot + + + align:start position:0% +culture in the Great Plains I know a lot +about that because I'm a loota and we + + align:start position:0% +about that because I'm a loota and we + + + align:start position:0% +about that because I'm a loota and we +followed the Buffalo herds and we had an + + align:start position:0% +followed the Buffalo herds and we had an + + + align:start position:0% +followed the Buffalo herds and we had an +evolution that in our own our own + + align:start position:0% +evolution that in our own our own + + + align:start position:0% +evolution that in our own our own +histories have seen us take us through a + + align:start position:0% +histories have seen us take us through a + + + align:start position:0% +histories have seen us take us through a +migration emerging Out of the Black + + align:start position:0% +migration emerging Out of the Black + + + align:start position:0% +migration emerging Out of the Black +Hills of South Dakota traversing through + + align:start position:0% +Hills of South Dakota traversing through + + + align:start position:0% +Hills of South Dakota traversing through +the this part down into the Carolinas + + align:start position:0% +the this part down into the Carolinas + + + align:start position:0% +the this part down into the Carolinas +and eventually back up into Minnesota + + align:start position:0% +and eventually back up into Minnesota + + + align:start position:0% +and eventually back up into Minnesota +and most recently in the past 200 years + + align:start position:0% +and most recently in the past 200 years + + + align:start position:0% +and most recently in the past 200 years +make our emergence back onto the Great + + align:start position:0% +make our emergence back onto the Great + + + align:start position:0% +make our emergence back onto the Great +Plains now that's our + + align:start position:0% +Plains now that's our + + + align:start position:0% +Plains now that's our +history a lot of these other ones I look + + align:start position:0% +history a lot of these other ones I look + + + align:start position:0% +history a lot of these other ones I look +towards like the northwest coast + + align:start position:0% +towards like the northwest coast + + + align:start position:0% +towards like the northwest coast +cultures evolved there because they're + + align:start position:0% +cultures evolved there because they're + + + align:start position:0% +cultures evolved there because they're +very rich in the uh resources from along + + align:start position:0% +very rich in the uh resources from along + + + align:start position:0% +very rich in the uh resources from along +the ocean so they've evolved to be + + align:start position:0% +the ocean so they've evolved to be + + + align:start position:0% +the ocean so they've evolved to be +salmon and Cedar people + + align:start position:0% +salmon and Cedar people + + + align:start position:0% +salmon and Cedar people +and they really evolved as a culture if + + align:start position:0% +and they really evolved as a culture if + + + align:start position:0% +and they really evolved as a culture if +you've SE ever seen their houses their + + align:start position:0% +you've SE ever seen their houses their + + + align:start position:0% +you've SE ever seen their houses their +carvings their totem poles very rich + + align:start position:0% +carvings their totem poles very rich + + + align:start position:0% +carvings their totem poles very rich +culture so every every geographical area + + align:start position:0% +culture so every every geographical area + + + align:start position:0% +culture so every every geographical area +has evolved a geog geographic area + + align:start position:0% +has evolved a geog geographic area + + + align:start position:0% +has evolved a geog geographic area +evolved a + + align:start position:0% +evolved a + + + align:start position:0% +evolved a +culture and I was telling these little + + align:start position:0% +culture and I was telling these little + + + align:start position:0% +culture and I was telling these little +kids at the space grants Consortium I + + align:start position:0% +kids at the space grants Consortium I + + + align:start position:0% +kids at the space grants Consortium I +said over here they're like the + + align:start position:0% +said over here they're like the + + + align:start position:0% +said over here they're like the +woodlands Indians you know they they + + align:start position:0% +woodlands Indians you know they they + + + align:start position:0% +woodlands Indians you know they they +their culture I said over here in + + align:start position:0% +their culture I said over here in + + + align:start position:0% +their culture I said over here in +Massachusetts I said I heard the story + + align:start position:0% +Massachusetts I said I heard the story + + + align:start position:0% +Massachusetts I said I heard the story +about how the native people + + align:start position:0% +about how the native people + + + align:start position:0% +about how the native people +there uh being the woodlands people they + + align:start position:0% +there uh being the woodlands people they + + + align:start position:0% +there uh being the woodlands people they +sort of like agriculturist they grew + + align:start position:0% +sort of like agriculturist they grew + + + align:start position:0% +sort of like agriculturist they grew +squash and beans and and + + align:start position:0% +squash and beans and and + + + align:start position:0% +squash and beans and and +corn said anybody ever here Boston baked + + align:start position:0% +corn said anybody ever here Boston baked + + + align:start position:0% +corn said anybody ever here Boston baked +beans well that's that's the native + + align:start position:0% +beans well that's that's the native + + + align:start position:0% +beans well that's that's the native +that's a native food they actually + + align:start position:0% +that's a native food they actually + + + align:start position:0% +that's a native food they actually +harvested the the beans that they grew + + align:start position:0% +harvested the the beans that they grew + + + align:start position:0% +harvested the the beans that they grew +and and utilized the the the sap from + + align:start position:0% +and and utilized the the the sap from + + + align:start position:0% +and and utilized the the the sap from +the maple trees and made syrup and bake + + align:start position:0% +the maple trees and made syrup and bake + + + align:start position:0% +the maple trees and made syrup and bake +that into in the in the ground and these + + align:start position:0% +that into in the in the ground and these + + + align:start position:0% +that into in the in the ground and these +clay ears and and that's how they + + align:start position:0% +clay ears and and that's how they + + + align:start position:0% +clay ears and and that's how they +invented the the the bust and make + + align:start position:0% +invented the the the bust and make + + + align:start position:0% +invented the the the bust and make +beans but you know Alo all the food + + align:start position:0% +beans but you know Alo all the food + + + align:start position:0% +beans but you know Alo all the food +sources everything that they can think + + align:start position:0% +sources everything that they can think + + + align:start position:0% +sources everything that they can think +of the medicinal plants all those things + + align:start position:0% +of the medicinal plants all those things + + + align:start position:0% +of the medicinal plants all those things +came from their geographic area so we + + align:start position:0% +came from their geographic area so we + + + align:start position:0% +came from their geographic area so we +see that land land Bas is like that as + + align:start position:0% +see that land land Bas is like that as + + + align:start position:0% +see that land land Bas is like that as +as something that the Earth the mother + + align:start position:0% +as something that the Earth the mother + + + align:start position:0% +as something that the Earth the mother +and itself gave to us and where we emerg + + align:start position:0% +and itself gave to us and where we emerg + + + align:start position:0% +and itself gave to us and where we emerg +from so we have all these cultural areas + + align:start position:0% +from so we have all these cultural areas + + + align:start position:0% +from so we have all these cultural areas +and I've seen other maps that divided us + + align:start position:0% +and I've seen other maps that divided us + + + align:start position:0% +and I've seen other maps that divided us +into linguistic groups but really we see + + align:start position:0% +into linguistic groups but really we see + + + align:start position:0% +into linguistic groups but really we see +all these things as the things that + + align:start position:0% +all these things as the things that + + + align:start position:0% +all these things as the things that +helped us grow in be a people and really + + align:start position:0% +helped us grow in be a people and really + + + align:start position:0% +helped us grow in be a people and really +develop our language and Concepts and + + align:start position:0% +develop our language and Concepts and + + + align:start position:0% +develop our language and Concepts and +spirituality come from these + + align:start position:0% +spirituality come from these + + + align:start position:0% +spirituality come from these +geographical areas that had all these + + align:start position:0% +geographical areas that had all these + + + align:start position:0% +geographical areas that had all these +resources but I guess you can see + + align:start position:0% +resources but I guess you can see + + + align:start position:0% +resources but I guess you can see +superimposed on that all of a sudden + + align:start position:0% +superimposed on that all of a sudden + + + align:start position:0% +superimposed on that all of a sudden +these these state lines and + + align:start position:0% +these these state lines and + + + align:start position:0% +these these state lines and +jurisdictional + + align:start position:0% +jurisdictional + + + align:start position:0% +jurisdictional +boundaries so we're kind of moving into + + align:start position:0% +boundaries so we're kind of moving into + + + align:start position:0% +boundaries so we're kind of moving into +an area I think two worlds starting to + + align:start position:0% +an area I think two worlds starting to + + + align:start position:0% +an area I think two worlds starting to +collide + + align:start position:0% +collide + + + align:start position:0% +collide +but I really want to uh uh + + align:start position:0% +but I really want to uh uh + + + align:start position:0% +but I really want to uh uh +uh help you with the concept about you + + align:start position:0% +uh help you with the concept about you + + + align:start position:0% +uh help you with the concept about you +know what I want to get into about about + + align:start position:0% +know what I want to get into about about + + + align:start position:0% +know what I want to get into about about +our Center about traditional knowledge + + align:start position:0% +our Center about traditional knowledge + + + align:start position:0% +our Center about traditional knowledge +so this is kind of information that + + align:start position:0% +so this is kind of information that + + + align:start position:0% +so this is kind of information that +helps you understand what really + + align:start position:0% +helps you understand what really + + + align:start position:0% +helps you understand what really +traditional knowledge is + + align:start position:0% +traditional knowledge is + + + align:start position:0% +traditional knowledge is +but but also this this map I just shown + + align:start position:0% +but but also this this map I just shown + + + align:start position:0% +but but also this this map I just shown +you right up here in the interior of + + align:start position:0% +you right up here in the interior of + + + align:start position:0% +you right up here in the interior of +British Columbia is called the gsan + + align:start position:0% +British Columbia is called the gsan + + + align:start position:0% +British Columbia is called the gsan +Aboriginal + + align:start position:0% +Aboriginal + + + align:start position:0% +Aboriginal +people and they were entering into what + + align:start position:0% +people and they were entering into what + + + align:start position:0% +people and they were entering into what +I called the land claims because they + + align:start position:0% +I called the land claims because they + + + align:start position:0% +I called the land claims because they +they never ever had a treaty in British + + align:start position:0% +they never ever had a treaty in British + + + align:start position:0% +they never ever had a treaty in British +Columbia even to today there's still no + + align:start position:0% +Columbia even to today there's still no + + + align:start position:0% +Columbia even to today there's still no +no treaty there + + align:start position:0% +no treaty there + + + align:start position:0% +no treaty there +yet but they had to articulate their + + align:start position:0% +yet but they had to articulate their + + + align:start position:0% +yet but they had to articulate their +world + + align:start position:0% +world + + + align:start position:0% +world +viw and what their how they could + + align:start position:0% +viw and what their how they could + + + align:start position:0% +viw and what their how they could +establish Aboriginal title to this land + + align:start position:0% +establish Aboriginal title to this land + + + align:start position:0% +establish Aboriginal title to this land +that they've always lived on and I + + align:start position:0% +that they've always lived on and I + + + align:start position:0% +that they've always lived on and I +thought this was very interesting and it + + align:start position:0% +thought this was very interesting and it + + + align:start position:0% +thought this was very interesting and it +really said something to me about who we + + align:start position:0% +really said something to me about who we + + + align:start position:0% +really said something to me about who we +are as native + + align:start position:0% +are as native + + + align:start position:0% +are as native +people these are all Clan houses all + + align:start position:0% +people these are all Clan houses all + + + align:start position:0% +people these are all Clan houses all +these different little polygons here are + + align:start position:0% +these different little polygons here are + + + align:start position:0% +these different little polygons here are +family groups that live together that + + align:start position:0% +family groups that live together that + + + align:start position:0% +family groups that live together that +they live on the land so each family + + align:start position:0% +they live on the land so each family + + + align:start position:0% +they live on the land so each family +Clan knew enough about that whole + + align:start position:0% +Clan knew enough about that whole + + + align:start position:0% +Clan knew enough about that whole +area about all the plants all the + + align:start position:0% +area about all the plants all the + + + align:start position:0% +area about all the plants all the +animals all the things that they + + align:start position:0% +animals all the things that they + + + align:start position:0% +animals all the things that they +subsisted with they knew about that so + + align:start position:0% +subsisted with they knew about that so + + + align:start position:0% +subsisted with they knew about that so +this story on how they had to describe + + align:start position:0% +this story on how they had to describe + + + align:start position:0% +this story on how they had to describe +their Aboriginal territory was + + align:start position:0% +their Aboriginal territory was + + + align:start position:0% +their Aboriginal territory was +internal and it came out to some kind of + + align:start position:0% +internal and it came out to some kind of + + + align:start position:0% +internal and it came out to some kind of +a + + align:start position:0% +a + + + align:start position:0% +a +boundary so I thought that's very + + align:start position:0% +boundary so I thought that's very + + + align:start position:0% +boundary so I thought that's very +interesting as as opposed to other + + align:start position:0% +interesting as as opposed to other + + + align:start position:0% +interesting as as opposed to other +people defining an area and chopping it + + align:start position:0% +people defining an area and chopping it + + + align:start position:0% +people defining an area and chopping it +up and saying that's it this one came + + align:start position:0% +up and saying that's it this one came + + + align:start position:0% +up and saying that's it this one came +from inside + + align:start position:0% + + + + align:start position:0% + +out so all this this this this knowledge + + align:start position:0% +out so all this this this this knowledge + + + align:start position:0% +out so all this this this this knowledge +was sort of expressed through + + align:start position:0% +was sort of expressed through + + + align:start position:0% +was sort of expressed through +understanding the migration patterns of + + align:start position:0% +understanding the migration patterns of + + + align:start position:0% +understanding the migration patterns of +animals their critical habitat and their + + align:start position:0% +animals their critical habitat and their + + + align:start position:0% +animals their critical habitat and their +traditions and + + align:start position:0% +traditions and + + + align:start position:0% +traditions and +culture and it was eventually bounded by + + align:start position:0% +culture and it was eventually bounded by + + + align:start position:0% +culture and it was eventually bounded by +a big giant uh wated all these had + + align:start position:0% +a big giant uh wated all these had + + + align:start position:0% +a big giant uh wated all these had +watersheds within them but this one here + + align:start position:0% +watersheds within them but this one here + + + align:start position:0% +watersheds within them but this one here +is Heights of + + align:start position:0% +is Heights of + + + align:start position:0% +is Heights of +land and a gigantic Watershed that + + align:start position:0% +land and a gigantic Watershed that + + + align:start position:0% +land and a gigantic Watershed that +really + + align:start position:0% +really + + + align:start position:0% +really +defined their their traditional + + align:start position:0% +defined their their traditional + + + align:start position:0% +defined their their traditional +territory so I thought that was very + + align:start position:0% +territory so I thought that was very + + + align:start position:0% +territory so I thought that was very +interesting that even today native + + align:start position:0% +interesting that even today native + + + align:start position:0% +interesting that even today native +people who are entering into uh treaties + + align:start position:0% +people who are entering into uh treaties + + + align:start position:0% +people who are entering into uh treaties +with federal government and land claims + + align:start position:0% +with federal government and land claims + + + align:start position:0% +with federal government and land claims +have the wherewithal and the connections + + align:start position:0% +have the wherewithal and the connections + + + align:start position:0% +have the wherewithal and the connections +to tell this story and what's + + align:start position:0% +to tell this story and what's + + + align:start position:0% +to tell this story and what's +interesting is this is all done in GIS + + align:start position:0% +interesting is this is all done in GIS + + + align:start position:0% +interesting is this is all done in GIS +geographic information systems to me is + + align:start position:0% +geographic information systems to me is + + + align:start position:0% +geographic information systems to me is +and + + align:start position:0% +and + + + align:start position:0% +and +unfortunately in my travels and and the + + align:start position:0% +unfortunately in my travels and and the + + + align:start position:0% +unfortunately in my travels and and the +things I was able to participate in this + + align:start position:0% +things I was able to participate in this + + + align:start position:0% +things I was able to participate in this +too was one of the most Innovative + + align:start position:0% +too was one of the most Innovative + + + align:start position:0% +too was one of the most Innovative +applications I've ever been part of in + + align:start position:0% +applications I've ever been part of in + + + align:start position:0% +applications I've ever been part of in +utilizing technology that has a vision + + align:start position:0% +utilizing technology that has a vision + + + align:start position:0% +utilizing technology that has a vision +that has a purpose that has a long + + align:start position:0% +that has a purpose that has a long + + + align:start position:0% +that has a purpose that has a long +reaching effect for a culture that that + + align:start position:0% +reaching effect for a culture that that + + + align:start position:0% +reaching effect for a culture that that +can survive for from here till + + align:start position:0% +can survive for from here till + + + align:start position:0% +can survive for from here till +forever you know so I I I thought that + + align:start position:0% +forever you know so I I I thought that + + + align:start position:0% +forever you know so I I I thought that +to be a very + + align:start position:0% +to be a very + + + align:start position:0% +to be a very +powerful uh example of traditional + + align:start position:0% +powerful uh example of traditional + + + align:start position:0% +powerful uh example of traditional +knowledge today and understanding how + + align:start position:0% +knowledge today and understanding how + + + align:start position:0% +knowledge today and understanding how +that applies to a + + align:start position:0% +that applies to a + + + align:start position:0% +that applies to a +future here again uh this area here is + + align:start position:0% +future here again uh this area here is + + + align:start position:0% +future here again uh this area here is +uh here's Washington State Idaho and + + align:start position:0% +uh here's Washington State Idaho and + + + align:start position:0% +uh here's Washington State Idaho and +Montana and there again you can see the + + align:start position:0% +Montana and there again you can see the + + + align:start position:0% +Montana and there again you can see the +49th parallel the Canadian + + align:start position:0% +49th parallel the Canadian + + + align:start position:0% +49th parallel the Canadian +border today even as n native people we + + align:start position:0% +border today even as n native people we + + + align:start position:0% +border today even as n native people we +refer to of that boundary is the + + align:start position:0% +refer to of that boundary is the + + + align:start position:0% +refer to of that boundary is the +medicine line I you know it's just a + + align:start position:0% +medicine line I you know it's just a + + + align:start position:0% +medicine line I you know it's just a +kind of this this fact it's it's it's we + + align:start position:0% +kind of this this fact it's it's it's we + + + align:start position:0% +kind of this this fact it's it's it's we +don't understand it we know it's there + + align:start position:0% +don't understand it we know it's there + + + align:start position:0% +don't understand it we know it's there +but you know what's the big deal but but + + align:start position:0% +but you know what's the big deal but but + + + align:start position:0% +but you know what's the big deal but but +there used to be there's a can import + + align:start position:0% +there used to be there's a can import + + + align:start position:0% +there used to be there's a can import +drug + + align:start position:0% +drug + + + align:start position:0% +drug +yeah yeah or get or get get out of the + + align:start position:0% +yeah yeah or get or get get out of the + + + align:start position:0% +yeah yeah or get or get get out of the +draft or something like that this + + align:start position:0% +draft or something like that this + + + align:start position:0% +draft or something like that this +magical line that's what it is that's + + align:start position:0% +magical line that's what it is that's + + + align:start position:0% +magical line that's what it is that's +why we called it the medicine + + align:start position:0% +why we called it the medicine + + + align:start position:0% +why we called it the medicine +line but there again cultures have + + align:start position:0% +line but there again cultures have + + + align:start position:0% +line but there again cultures have +existed within this whole area here and + + align:start position:0% +existed within this whole area here and + + + align:start position:0% +existed within this whole area here and +just will happen all these + + align:start position:0% +just will happen all these + + + align:start position:0% +just will happen all these +jurisdictional boundaries I here but + + align:start position:0% +jurisdictional boundaries I here but + + + align:start position:0% +jurisdictional boundaries I here but +then the uh tonoa Nation still had you + + align:start position:0% +then the uh tonoa Nation still had you + + + align:start position:0% +then the uh tonoa Nation still had you +know they had an affiliation to this + + align:start position:0% +know they had an affiliation to this + + + align:start position:0% +know they had an affiliation to this +whole land base here all the way along + + align:start position:0% +whole land base here all the way along + + + align:start position:0% +whole land base here all the way along +the sort of the the the Canadian Rockies + + align:start position:0% +the sort of the the the Canadian Rockies + + + align:start position:0% +the sort of the the the Canadian Rockies +inside there and yet they they have + + align:start position:0% +inside there and yet they they have + + + align:start position:0% +inside there and yet they they have +cultural areas that they still identify + + align:start position:0% +cultural areas that they still identify + + + align:start position:0% +cultural areas that they still identify +with you know so they they they have + + align:start position:0% +with you know so they they they have + + + align:start position:0% +with you know so they they they have +identified their Aboriginal territory as + + align:start position:0% +identified their Aboriginal territory as + + + align:start position:0% +identified their Aboriginal territory as +you can see uh + + align:start position:0% +you can see uh + + + align:start position:0% +you can see uh +by all these little Camp settlements and + + align:start position:0% +by all these little Camp settlements and + + + align:start position:0% +by all these little Camp settlements and +all that that they still relate to and + + align:start position:0% +all that that they still relate to and + + + align:start position:0% +all that that they still relate to and +all that but they're again the only land + + align:start position:0% +all that but they're again the only land + + + align:start position:0% +all that but they're again the only land +claim that they can make is stops right + + align:start position:0% +claim that they can make is stops right + + + align:start position:0% +claim that they can make is stops right +there at the international + + align:start position:0% +there at the international + + + align:start position:0% +there at the international +boundary so we're still encumbered by a + + align:start position:0% +boundary so we're still encumbered by a + + + align:start position:0% +boundary so we're still encumbered by a +lot of these things but we still hold + + align:start position:0% +lot of these things but we still hold + + + align:start position:0% +lot of these things but we still hold +alive this idea of an area that we are + + align:start position:0% +alive this idea of an area that we are + + + align:start position:0% +alive this idea of an area that we are +connected to + + align:start position:0% + + + + align:start position:0% + +ancestrally one of do BL commun go to + + align:start position:0% +ancestrally one of do BL commun go to + + + align:start position:0% +ancestrally one of do BL commun go to +some stewardship courses we talk uh one + + align:start position:0% +some stewardship courses we talk uh one + + + align:start position:0% +some stewardship courses we talk uh one +of the instructors there talks about + + align:start position:0% +of the instructors there talks about + + + align:start position:0% +of the instructors there talks about +human Geographic units and these + + align:start position:0% +human Geographic units and these + + + align:start position:0% +human Geographic units and these +cultural units as opposed to political + + align:start position:0% +cultural units as opposed to political + + + align:start position:0% +cultural units as opposed to political +boundaries and they've done an analysis + + align:start position:0% +boundaries and they've done an analysis + + + align:start position:0% +boundaries and they've done an analysis +of of this because just exactly as + + align:start position:0% +of of this because just exactly as + + + align:start position:0% +of of this because just exactly as +you're explaining people are tied + + align:start position:0% +you're explaining people are tied + + + align:start position:0% +you're explaining people are tied +together by these by these cultural + + align:start position:0% +together by these by these cultural + + + align:start position:0% +together by these by these cultural +units and uh I don't know interestingly + + align:start position:0% +units and uh I don't know interestingly + + + align:start position:0% +units and uh I don't know interestingly +a couple of years ago we were doing a + + align:start position:0% +a couple of years ago we were doing a + + + align:start position:0% +a couple of years ago we were doing a +training at um mlin Nevada mclin is a + + align:start position:0% +training at um mlin Nevada mclin is a + + + align:start position:0% +training at um mlin Nevada mclin is a +casino town I hadn't realized that + + align:start position:0% +casino town I hadn't realized that + + + align:start position:0% +casino town I hadn't realized that +thought it was going out to the desert + + align:start position:0% +thought it was going out to the desert + + + align:start position:0% +thought it was going out to the desert +getting away from that but the people + + align:start position:0% +getting away from that but the people + + + align:start position:0% +getting away from that but the people +that were coming the training right + + align:start position:0% +that were coming the training right + + + align:start position:0% +that were coming the training right +across 10 minutes away across the river + + align:start position:0% +across 10 minutes away across the river + + + align:start position:0% +across 10 minutes away across the river +in Bullhead City Arizona across the + + align:start position:0% +in Bullhead City Arizona across the + + + align:start position:0% +in Bullhead City Arizona across the +Colorado River and we expected 4045 + + align:start position:0% +Colorado River and we expected 4045 + + + align:start position:0% +Colorado River and we expected 4045 +people at the training they for some + + align:start position:0% +people at the training they for some + + + align:start position:0% +people at the training they for some +reason held it in this casino we got + + align:start position:0% +reason held it in this casino we got + + + align:start position:0% +reason held it in this casino we got +eight and we had to uh cancel the + + align:start position:0% +eight and we had to uh cancel the + + + align:start position:0% +eight and we had to uh cancel the +training the Colorado at that point + + align:start position:0% +training the Colorado at that point + + + align:start position:0% +training the Colorado at that point +happened to be one of these cultural + + align:start position:0% +happened to be one of these cultural + + + align:start position:0% +happened to be one of these cultural +boundaries that we had M so we don't + + align:start position:0% +boundaries that we had M so we don't + + + align:start position:0% +boundaries that we had M so we don't +know if that was the prohibitor or what + + align:start position:0% +know if that was the prohibitor or what + + + align:start position:0% +know if that was the prohibitor or what +was the prohibitor uh we we suspect had + + align:start position:0% +was the prohibitor uh we we suspect had + + + align:start position:0% +was the prohibitor uh we we suspect had +we held it in a Schoolhouse or a + + align:start position:0% +we held it in a Schoolhouse or a + + + align:start position:0% +we held it in a Schoolhouse or a +firehouse in bhead city we would have + + align:start position:0% +firehouse in bhead city we would have + + + align:start position:0% +firehouse in bhead city we would have +gotten full complimented people but I I + + align:start position:0% +gotten full complimented people but I I + + + align:start position:0% +gotten full complimented people but I I +think there's you know my own view a lot + + align:start position:0% +think there's you know my own view a lot + + + align:start position:0% +think there's you know my own view a lot +of power for this concept yeah there is + + align:start position:0% +of power for this concept yeah there is + + + align:start position:0% +of power for this concept yeah there is +yeah in fact they seem to be more + + align:start position:0% +yeah in fact they seem to be more + + + align:start position:0% +yeah in fact they seem to be more +inclusive I think they broaden + + align:start position:0% +inclusive I think they broaden + + + align:start position:0% +inclusive I think they broaden +it uh so that was in Canada some of the + + align:start position:0% +it uh so that was in Canada some of the + + + align:start position:0% +it uh so that was in Canada some of the +stories that I was just going to some of + + align:start position:0% +stories that I was just going to some of + + + align:start position:0% +stories that I was just going to some of +the things I kind of personally know of + + align:start position:0% +the things I kind of personally know of + + + align:start position:0% +the things I kind of personally know of +but but all you know so I came back to + + align:start position:0% +but but all you know so I came back to + + + align:start position:0% +but but all you know so I came back to +Canada this was probably about 10 years + + align:start position:0% +Canada this was probably about 10 years + + + align:start position:0% +Canada this was probably about 10 years +ago when I was up there working in the + + align:start position:0% +ago when I was up there working in the + + + align:start position:0% +ago when I was up there working in the +land claims and and I came back to talk + + align:start position:0% +land claims and and I came back to talk + + + align:start position:0% +land claims and and I came back to talk +to other native professionals and this + + align:start position:0% +to other native professionals and this + + + align:start position:0% +to other native professionals and this +whole idea of ad oral territory wasn't + + align:start position:0% +whole idea of ad oral territory wasn't + + + align:start position:0% +whole idea of ad oral territory wasn't +as strong here in the US because of the + + align:start position:0% +as strong here in the US because of the + + + align:start position:0% +as strong here in the US because of the +paternal of federal + + align:start position:0% +paternal of federal + + + align:start position:0% +paternal of federal +government but this is a recent one that + + align:start position:0% +government but this is a recent one that + + + align:start position:0% +government but this is a recent one that +came out in about the last three years + + align:start position:0% +came out in about the last three years + + + align:start position:0% +came out in about the last three years +uh the cordelane tribe on their uh uh + + align:start position:0% +uh the cordelane tribe on their uh uh + + + align:start position:0% +uh the cordelane tribe on their uh uh +website they have a GIS program there + + align:start position:0% +website they have a GIS program there + + + align:start position:0% +website they have a GIS program there +have actually identify their Aboriginal + + align:start position:0% +have actually identify their Aboriginal + + + align:start position:0% +have actually identify their Aboriginal +territory so that that's kind of a + + align:start position:0% +territory so that that's kind of a + + + align:start position:0% +territory so that that's kind of a +concept that's coming back again to + + align:start position:0% +concept that's coming back again to + + + align:start position:0% +concept that's coming back again to +Native people is a reconnection to a + + align:start position:0% +Native people is a reconnection to a + + + align:start position:0% +Native people is a reconnection to a +landbase beyond their their little + + align:start position:0% +landbase beyond their their little + + + align:start position:0% +landbase beyond their their little +reservation like you can see this is all + + align:start position:0% +reservation like you can see this is all + + + align:start position:0% +reservation like you can see this is all +that they really have right now um + + align:start position:0% +that they really have right now um + + + align:start position:0% +that they really have right now um +through their treaty process and land + + align:start position:0% +through their treaty process and land + + + align:start position:0% +through their treaty process and land +sessions but they still have a + + align:start position:0% +sessions but they still have a + + + align:start position:0% +sessions but they still have a +connection to all these uh uh cultural + + align:start position:0% +connection to all these uh uh cultural + + + align:start position:0% +connection to all these uh uh cultural +sites and then they really there yeah + + align:start position:0% +sites and then they really there yeah + + + align:start position:0% +sites and then they really there yeah +there's some arbitrary lines here but + + align:start position:0% +there's some arbitrary lines here but + + + align:start position:0% +there's some arbitrary lines here but +you could see all these things are + + align:start position:0% +you could see all these things are + + + align:start position:0% +you could see all these things are +probably pretty much bounded by some + + align:start position:0% +probably pretty much bounded by some + + + align:start position:0% +probably pretty much bounded by some +kind of a natural feature that really + + align:start position:0% +kind of a natural feature that really + + + align:start position:0% +kind of a natural feature that really +identifies their Aboriginal + + align:start position:0% +identifies their Aboriginal + + + align:start position:0% +identifies their Aboriginal +territory so you can see us I I always + + align:start position:0% +territory so you can see us I I always + + + align:start position:0% +territory so you can see us I I always +felt this as a as a as a Renaissance As + + align:start position:0% +felt this as a as a as a Renaissance As + + + align:start position:0% +felt this as a as a as a Renaissance As +happening with Native culture and how + + align:start position:0% +happening with Native culture and how + + + align:start position:0% +happening with Native culture and how +technology is becoming part of that + + align:start position:0% +technology is becoming part of that + + + align:start position:0% +technology is becoming part of that +Renaissance and they are starting to + + align:start position:0% +Renaissance and they are starting to + + + align:start position:0% +Renaissance and they are starting to +kick out cargraphic products like that + + align:start position:0% +kick out cargraphic products like that + + + align:start position:0% +kick out cargraphic products like that +to identify their Aboriginal territory + + align:start position:0% +to identify their Aboriginal territory + + + align:start position:0% +to identify their Aboriginal territory +those are very Sovereign statements in + + align:start position:0% +those are very Sovereign statements in + + + align:start position:0% +those are very Sovereign statements in +itself this is another uh example that I + + align:start position:0% +itself this is another uh example that I + + + align:start position:0% +itself this is another uh example that I +was involved in with the Squamish nation + + align:start position:0% +was involved in with the Squamish nation + + + align:start position:0% +was involved in with the Squamish nation +in uh their their their headquarters is + + align:start position:0% +in uh their their their headquarters is + + + align:start position:0% +in uh their their their headquarters is +in North Vancouver BC so what I'm going + + align:start position:0% +in North Vancouver BC so what I'm going + + + align:start position:0% +in North Vancouver BC so what I'm going +to show you here is their their idea of + + align:start position:0% +to show you here is their their idea of + + + align:start position:0% +to show you here is their their idea of +the Aboriginal territory that they + + align:start position:0% +the Aboriginal territory that they + + + align:start position:0% +the Aboriginal territory that they +identified and they they went about it a + + align:start position:0% +identified and they they went about it a + + + align:start position:0% +identified and they they went about it a +little bit different they actually + + align:start position:0% +little bit different they actually + + + align:start position:0% +little bit different they actually +substantiated by the arch iological + + align:start position:0% +substantiated by the arch iological + + + align:start position:0% +substantiated by the arch iological +record by a lot of the uh external + + align:start position:0% +record by a lot of the uh external + + + align:start position:0% +record by a lot of the uh external +research that they did Beyond just + + align:start position:0% +research that they did Beyond just + + + align:start position:0% +research that they did Beyond just +themselves so they utilize some of the + + align:start position:0% +themselves so they utilize some of the + + + align:start position:0% +themselves so they utilize some of the +mainstream information ethnographic and + + align:start position:0% +mainstream information ethnographic and + + + align:start position:0% +mainstream information ethnographic and +historic research and they also + + align:start position:0% +historic research and they also + + + align:start position:0% +historic research and they also +substantiated it with their oral + + align:start position:0% +substantiated it with their oral + + + align:start position:0% +substantiated it with their oral +Traditions so as a result they submitted + + align:start position:0% +Traditions so as a result they submitted + + + align:start position:0% +Traditions so as a result they submitted +a map for the tree process that + + align:start position:0% +a map for the tree process that + + + align:start position:0% +a map for the tree process that +identifies an area of occupancy within + + align:start position:0% +identifies an area of occupancy within + + + align:start position:0% +identifies an area of occupancy within +the natural boundaries of heights lands + + align:start position:0% +the natural boundaries of heights lands + + + align:start position:0% +the natural boundaries of heights lands +and Watershed see it's that a big + + align:start position:0% +and Watershed see it's that a big + + + align:start position:0% +and Watershed see it's that a big +gigantic uh Watershed there and that's + + align:start position:0% +gigantic uh Watershed there and that's + + + align:start position:0% +gigantic uh Watershed there and that's +the Frasier River where they subsisted + + align:start position:0% +the Frasier River where they subsisted + + + align:start position:0% +the Frasier River where they subsisted +culturally with all the salmon so they + + align:start position:0% +culturally with all the salmon so they + + + align:start position:0% +culturally with all the salmon so they +knew all the streams and all those + + align:start position:0% +knew all the streams and all those + + + align:start position:0% +knew all the streams and all those +things so they they they really brought + + align:start position:0% +things so they they they really brought + + + align:start position:0% +things so they they they really brought +about a strong story when they when they + + align:start position:0% +about a strong story when they when they + + + align:start position:0% +about a strong story when they when they +involved all that nobody could dispute + + align:start position:0% +involved all that nobody could dispute + + + align:start position:0% +involved all that nobody could dispute +the archaeological record and all that + + align:start position:0% +the archaeological record and all that + + + align:start position:0% +the archaeological record and all that +but but interesting enough to the to the + + align:start position:0% +but but interesting enough to the to the + + + align:start position:0% +but but interesting enough to the to the +land claims in in in Canada is um is + + align:start position:0% +land claims in in in Canada is um is + + + align:start position:0% +land claims in in in Canada is um is +back in 1999 was the delam decision + + align:start position:0% +back in 1999 was the delam decision + + + align:start position:0% +back in 1999 was the delam decision +which really sort of validate this idea + + align:start position:0% +which really sort of validate this idea + + + align:start position:0% +which really sort of validate this idea +of oral tradition and traditional + + align:start position:0% +of oral tradition and traditional + + + align:start position:0% +of oral tradition and traditional +knowledge that it overturned a lower + + align:start position:0% +knowledge that it overturned a lower + + + align:start position:0% +knowledge that it overturned a lower +court decision in British Columbia to + + align:start position:0% +court decision in British Columbia to + + + align:start position:0% +court decision in British Columbia to +say say is that traditional knowledge + + align:start position:0% +say say is that traditional knowledge + + + align:start position:0% +say say is that traditional knowledge +oral histories and tradition are part of + + align:start position:0% +oral histories and tradition are part of + + + align:start position:0% +oral histories and tradition are part of +the claim for for Aboriginal title to + + align:start position:0% +the claim for for Aboriginal title to + + + align:start position:0% +the claim for for Aboriginal title to +the land so that really validates and + + align:start position:0% +the land so that really validates and + + + align:start position:0% +the land so that really validates and +there's nothing like that significant in + + align:start position:0% +there's nothing like that significant in + + + align:start position:0% +there's nothing like that significant in +the US that has validated traditional + + align:start position:0% +the US that has validated traditional + + + align:start position:0% +the US that has validated traditional +knowledge other than a Native American + + align:start position:0% +knowledge other than a Native American + + + align:start position:0% +knowledge other than a Native American +Graves protection repatriation act + + align:start position:0% +Graves protection repatriation act + + + align:start position:0% +Graves protection repatriation act +that's just a crack in the door for + + align:start position:0% +that's just a crack in the door for + + + align:start position:0% +that's just a crack in the door for +people in the US that validates their U + + align:start position:0% +people in the US that validates their U + + + align:start position:0% +people in the US that validates their U +their traditional knowledge but I will + + align:start position:0% +their traditional knowledge but I will + + + align:start position:0% +their traditional knowledge but I will +say for the USGS to + + align:start position:0% +say for the USGS to + + + align:start position:0% +say for the USGS to +invite cin geska to be part of this + + align:start position:0% +invite cin geska to be part of this + + + align:start position:0% +invite cin geska to be part of this +science impact with this sort of the + + align:start position:0% +science impact with this sort of the + + + align:start position:0% +science impact with this sort of the +doors open to to Really explore and + + align:start position:0% +doors open to to Really explore and + + + align:start position:0% +doors open to to Really explore and +understand the relevancies of + + align:start position:0% +understand the relevancies of + + + align:start position:0% +understand the relevancies of +traditional knowledge I think that's + + align:start position:0% +traditional knowledge I think that's + + + align:start position:0% +traditional knowledge I think that's +very Innovative far-reaching people are + + align:start position:0% +very Innovative far-reaching people are + + + align:start position:0% +very Innovative far-reaching people are +going to benefit from that we're going + + align:start position:0% +going to benefit from that we're going + + + align:start position:0% +going to benefit from that we're going +to benefit and I think what we have and + + align:start position:0% +to benefit and I think what we have and + + + align:start position:0% +to benefit and I think what we have and +how we're learning to articulate that + + align:start position:0% +how we're learning to articulate that + + + align:start position:0% +how we're learning to articulate that +going to really benefit Society I'm + + align:start position:0% +going to really benefit Society I'm + + + align:start position:0% +going to really benefit Society I'm +really looking toward forward to + + align:start position:0% +really looking toward forward to + + + align:start position:0% +really looking toward forward to +that but those are just ideas so it + + align:start position:0% +that but those are just ideas so it + + + align:start position:0% +that but those are just ideas so it +gives you this idea what I call another + + align:start position:0% +gives you this idea what I call another + + + align:start position:0% +gives you this idea what I call another +America how people really still see the + + align:start position:0% +America how people really still see the + + + align:start position:0% +America how people really still see the +land and relate to it and when they have + + align:start position:0% +land and relate to it and when they have + + + align:start position:0% +land and relate to it and when they have +to really identify it and articulate it + + align:start position:0% +to really identify it and articulate it + + + align:start position:0% +to really identify it and articulate it +this is what you see you just see these + + align:start position:0% +this is what you see you just see these + + + align:start position:0% +this is what you see you just see these +irregular looking polygons that are part + + align:start position:0% +irregular looking polygons that are part + + + align:start position:0% +irregular looking polygons that are part +of what we call natural + + align:start position:0% +of what we call natural + + + align:start position:0% +of what we call natural +law yes today I don't know if anybody + + align:start position:0% +law yes today I don't know if anybody + + + align:start position:0% +law yes today I don't know if anybody +really ever studies these kind of maps + + align:start position:0% +really ever studies these kind of maps + + + align:start position:0% +really ever studies these kind of maps +but you know I look at them occasionally + + align:start position:0% +but you know I look at them occasionally + + + align:start position:0% +but you know I look at them occasionally +and I shake my head and and realize that + + align:start position:0% +and I shake my head and and realize that + + + align:start position:0% +and I shake my head and and realize that +you know our culture was a buffalo + + align:start position:0% +you know our culture was a buffalo + + + align:start position:0% +you know our culture was a buffalo +culture we traversed the Great Plains + + align:start position:0% +culture we traversed the Great Plains + + + align:start position:0% +culture we traversed the Great Plains +but this is our reality real it and this + + align:start position:0% +but this is our reality real it and this + + + align:start position:0% +but this is our reality real it and this +is the reality today as it is right now + + align:start position:0% +is the reality today as it is right now + + + align:start position:0% +is the reality today as it is right now +in Indian + + align:start position:0% +in Indian + + + align:start position:0% +in Indian +Country you don't see that many + + align:start position:0% +Country you don't see that many + + + align:start position:0% +Country you don't see that many +reservations over here in the East but + + align:start position:0% +reservations over here in the East but + + + align:start position:0% +reservations over here in the East but +so recent history is kind of uh in front + + align:start position:0% +so recent history is kind of uh in front + + + align:start position:0% +so recent history is kind of uh in front +of you right now for what where Indian + + align:start position:0% +of you right now for what where Indian + + + align:start position:0% +of you right now for what where Indian +people live what we + + align:start position:0% +people live what we + + + align:start position:0% +people live what we +have we're even thrown into places where + + align:start position:0% +have we're even thrown into places where + + + align:start position:0% +have we're even thrown into places where +there's reservations within reservations + + align:start position:0% +there's reservations within reservations + + + align:start position:0% +there's reservations within reservations +can you can imagine the conflict and + + align:start position:0% +can you can imagine the conflict and + + + align:start position:0% +can you can imagine the conflict and +culture there two different language + + align:start position:0% +culture there two different language + + + align:start position:0% +culture there two different language +groups two different customs and yet + + align:start position:0% +groups two different customs and yet + + + align:start position:0% +groups two different customs and yet +they're forced to live side by side and + + align:start position:0% +they're forced to live side by side and + + + align:start position:0% +they're forced to live side by side and +all those things are mandated by federal + + align:start position:0% +all those things are mandated by federal + + + align:start position:0% +all those things are mandated by federal +policies and treaties so that's just an + + align:start position:0% +policies and treaties so that's just an + + + align:start position:0% +policies and treaties so that's just an +idea of the the jurisdictional + + align:start position:0% +idea of the the jurisdictional + + + align:start position:0% +idea of the the jurisdictional +boundaries of the bureau venan Affairs + + align:start position:0% +boundaries of the bureau venan Affairs + + + align:start position:0% +boundaries of the bureau venan Affairs +their different regions and and how they + + align:start position:0% +their different regions and and how they + + + align:start position:0% +their different regions and and how they +manage + + align:start position:0% +manage + + + align:start position:0% +manage +us okay well you know maybe that's it + + align:start position:0% +us okay well you know maybe that's it + + + align:start position:0% +us okay well you know maybe that's it +you know when I look at these Maps + + align:start position:0% +you know when I look at these Maps + + + align:start position:0% +you know when I look at these Maps +they're there that's a + + align:start position:0% +they're there that's a + + + align:start position:0% +they're there that's a +reality and you look at Oklahoma for + + align:start position:0% +reality and you look at Oklahoma for + + + align:start position:0% +reality and you look at Oklahoma for +what it is there's many there's not that + + align:start position:0% +what it is there's many there's not that + + + align:start position:0% +what it is there's many there's not that +many reservations but there's so many uh + + align:start position:0% +many reservations but there's so many uh + + + align:start position:0% +many reservations but there's so many uh +different tribes there if you can + + align:start position:0% +different tribes there if you can + + + align:start position:0% +different tribes there if you can +imagine all the assimilation policies in + + align:start position:0% +imagine all the assimilation policies in + + + align:start position:0% +imagine all the assimilation policies in +oppos on any people Oklahoma is a + + align:start position:0% +oppos on any people Oklahoma is a + + + align:start position:0% +oppos on any people Oklahoma is a +shining example they moved the seols + + align:start position:0% +shining example they moved the seols + + + align:start position:0% +shining example they moved the seols +there they moved Delaware people there + + align:start position:0% +there they moved Delaware people there + + + align:start position:0% +there they moved Delaware people there +they moved they just moved a lot of + + align:start position:0% +they moved they just moved a lot of + + + align:start position:0% +they moved they just moved a lot of +tribes from the East and Cherokee here + + align:start position:0% +tribes from the East and Cherokee here + + + align:start position:0% +tribes from the East and Cherokee here +that was Indian Country they said asde + + align:start position:0% +that was Indian Country they said asde + + + align:start position:0% +that was Indian Country they said asde +to move all the Indians to so right now + + align:start position:0% +to move all the Indians to so right now + + + align:start position:0% +to move all the Indians to so right now +there's this conglomeration of different + + align:start position:0% +there's this conglomeration of different + + + align:start position:0% +there's this conglomeration of different +tribes that live there on little + + align:start position:0% +tribes that live there on little + + + align:start position:0% +tribes that live there on little +settlements they do have + + align:start position:0% +settlements they do have + + + align:start position:0% +settlements they do have +allotments and I think they're like + + align:start position:0% +allotments and I think they're like + + + align:start position:0% +allotments and I think they're like +little county seats that really govern + + align:start position:0% +little county seats that really govern + + + align:start position:0% +little county seats that really govern +them but they don't really have any + + align:start position:0% +them but they don't really have any + + + align:start position:0% +them but they don't really have any +reservation lands Collective land + + align:start position:0% +reservation lands Collective land + + + align:start position:0% +reservation lands Collective land +Holdings like the other tribes who who + + align:start position:0% +Holdings like the other tribes who who + + + align:start position:0% +Holdings like the other tribes who who +have negotiated with the federal + + align:start position:0% +have negotiated with the federal + + + align:start position:0% +have negotiated with the federal +government these guys were forc marched + + align:start position:0% +government these guys were forc marched + + + align:start position:0% +government these guys were forc marched +out of their different land + + align:start position:0% +out of their different land + + + align:start position:0% +out of their different land +areas so it's kind of a Melting Pot of + + align:start position:0% +areas so it's kind of a Melting Pot of + + + align:start position:0% +areas so it's kind of a Melting Pot of +Indian culture in + + align:start position:0% +Indian culture in + + + align:start position:0% +Indian culture in +Oklahoma mention one thing about the + + align:start position:0% +Oklahoma mention one thing about the + + + align:start position:0% +Oklahoma mention one thing about the +East and that story in Upstate New York + + align:start position:0% +East and that story in Upstate New York + + + align:start position:0% +East and that story in Upstate New York +when they're trying to resolve land + + align:start position:0% +when they're trying to resolve land + + + align:start position:0% +when they're trying to resolve land +claims you have a split you have people + + align:start position:0% +claims you have a split you have people + + + align:start position:0% +claims you have a split you have people +who stayed on the land in Upstate New + + align:start position:0% +who stayed on the land in Upstate New + + + align:start position:0% +who stayed on the land in Upstate New +York who are One Tribe and you have + + align:start position:0% +York who are One Tribe and you have + + + align:start position:0% +York who are One Tribe and you have +people people from that same tribe who + + align:start position:0% +people people from that same tribe who + + + align:start position:0% +people people from that same tribe who +got moved out to Oklahoma when the + + align:start position:0% +got moved out to Oklahoma when the + + + align:start position:0% +got moved out to Oklahoma when the +negotiation is going on between the + + align:start position:0% +negotiation is going on between the + + + align:start position:0% +negotiation is going on between the +tribe and the state about what's going + + align:start position:0% +tribe and the state about what's going + + + align:start position:0% +tribe and the state about what's going +to happen you've got this group out in + + align:start position:0% +to happen you've got this group out in + + + align:start position:0% +to happen you've got this group out in +Oklahoma who say well we should be part + + align:start position:0% +Oklahoma who say well we should be part + + + align:start position:0% +Oklahoma who say well we should be part +of that negotiation this is our tribe we + + align:start position:0% +of that negotiation this is our tribe we + + + align:start position:0% +of that negotiation this is our tribe we +may live out here but we're part of that + + align:start position:0% +may live out here but we're part of that + + + align:start position:0% +may live out here but we're part of that +and their attitude actually turned out + + align:start position:0% +and their attitude actually turned out + + + align:start position:0% +and their attitude actually turned out +to be quite different from a lot of the + + align:start position:0% +to be quite different from a lot of the + + + align:start position:0% +to be quite different from a lot of the +others they were more willing to + + align:start position:0% +others they were more willing to + + + align:start position:0% +others they were more willing to +negotiate for money rather than land + + align:start position:0% +negotiate for money rather than land + + + align:start position:0% +negotiate for money rather than land +because they're already moved + + align:start position:0% +because they're already moved + + + align:start position:0% +because they're already moved +but there was a real internal conflict + + align:start position:0% +but there was a real internal conflict + + + align:start position:0% +but there was a real internal conflict +caused by that for + + align:start position:0% +caused by that for + + + align:start position:0% +caused by that for +migration same way with the chalk to + + align:start position:0% +migration same way with the chalk to + + + align:start position:0% +migration same way with the chalk to +there moved out to Oklahoma but a ban + + align:start position:0% +there moved out to Oklahoma but a ban + + + align:start position:0% +there moved out to Oklahoma but a ban +State here and eventually uh super + + align:start position:0% +State here and eventually uh super + + + align:start position:0% +State here and eventually uh super +persists became very wealthy so I don't + + align:start position:0% +persists became very wealthy so I don't + + + align:start position:0% +persists became very wealthy so I don't +know if you refer to them but that's + + align:start position:0% +know if you refer to them but that's + + + align:start position:0% +know if you refer to them but that's +Chief Phil Martin and his group down + + align:start position:0% +Chief Phil Martin and his group down + + + align:start position:0% +Chief Phil Martin and his group down +there very wealthy native people through + + align:start position:0% +there very wealthy native people through + + + align:start position:0% +there very wealthy native people through +gaming but yeah you you you just see you + + align:start position:0% +gaming but yeah you you you just see you + + + align:start position:0% +gaming but yeah you you you just see you +know that that that is a very that's a + + align:start position:0% +know that that that is a very that's a + + + align:start position:0% +know that that that is a very that's a +phenomena here in the US most people + + align:start position:0% +phenomena here in the US most people + + + align:start position:0% +phenomena here in the US most people +don't really realize all those + + align:start position:0% +don't really realize all those + + + align:start position:0% +don't really realize all those +assimilation policies imposed on Native + + align:start position:0% +assimilation policies imposed on Native + + + align:start position:0% +assimilation policies imposed on Native +Americans and + + align:start position:0% +Americans and + + + align:start position:0% +Americans and +so but what is happening anyway in + + align:start position:0% +so but what is happening anyway in + + + align:start position:0% +so but what is happening anyway in +reality a lot of these tribes are + + align:start position:0% +reality a lot of these tribes are + + + align:start position:0% +reality a lot of these tribes are +connecting culturally and there's there + + align:start position:0% +connecting culturally and there's there + + + align:start position:0% +connecting culturally and there's there +just just just just Greening of America + + align:start position:0% +just just just just Greening of America + + + align:start position:0% +just just just just Greening of America +I guess you could say through through + + align:start position:0% +I guess you could say through through + + + align:start position:0% +I guess you could say through through +native culture because we we see the + + align:start position:0% +native culture because we we see the + + + align:start position:0% +native culture because we we see the +richness in our own cultures to share it + + align:start position:0% +richness in our own cultures to share it + + + align:start position:0% +richness in our own cultures to share it +with one another so there's many inter + + align:start position:0% +with one another so there's many inter + + + align:start position:0% +with one another so there's many inter +marriages here's another reality about + + align:start position:0% +marriages here's another reality about + + + align:start position:0% +marriages here's another reality about +America and itself too what Native + + align:start position:0% +America and itself too what Native + + + align:start position:0% +America and itself too what Native +people understand sometimes when when I + + align:start position:0% +people understand sometimes when when I + + + align:start position:0% +people understand sometimes when when I +put this map up in front of native + + align:start position:0% +put this map up in front of native + + + align:start position:0% +put this map up in front of native +people they get very + + align:start position:0% +people they get very + + + align:start position:0% +people they get very +angry but then I I turn that anger + + align:start position:0% +angry but then I I turn that anger + + + align:start position:0% +angry but then I I turn that anger +around and said well you know why don't + + align:start position:0% +around and said well you know why don't + + + align:start position:0% +around and said well you know why don't +you define your own tribal your + + align:start position:0% +you define your own tribal your + + + align:start position:0% +you define your own tribal your +Aboriginal Homeland because this was a + + align:start position:0% +Aboriginal Homeland because this was a + + + align:start position:0% +Aboriginal Homeland because this was a +done for you it was adjudicated + + align:start position:0% +done for you it was adjudicated + + + align:start position:0% +done for you it was adjudicated +judicially established Indian land areas + + align:start position:0% +judicially established Indian land areas + + + align:start position:0% +judicially established Indian land areas +the government actually had to come up + + align:start position:0% +the government actually had to come up + + + align:start position:0% +the government actually had to come up +with their own document to show the land + + align:start position:0% +with their own document to show the land + + + align:start position:0% +with their own document to show the land +areas that they actually bought or + + align:start position:0% +areas that they actually bought or + + + align:start position:0% +areas that they actually bought or +appropriated from native people so it + + align:start position:0% +appropriated from native people so it + + + align:start position:0% +appropriated from native people so it +stands out to be this document in the + + align:start position:0% +stands out to be this document in the + + + align:start position:0% +stands out to be this document in the +sense that says who are the sers of the + + align:start position:0% +sense that says who are the sers of the + + + align:start position:0% +sense that says who are the sers of the +land + + align:start position:0% +land + + + align:start position:0% +land +were + + align:start position:0% +were + + + align:start position:0% +were +well and they were given up until 1978 + + align:start position:0% +well and they were given up until 1978 + + + align:start position:0% +well and they were given up until 1978 +the tribal people to put in claims of + + align:start position:0% +the tribal people to put in claims of + + + align:start position:0% +the tribal people to put in claims of +any kind of a against the land that was + + align:start position:0% +any kind of a against the land that was + + + align:start position:0% +any kind of a against the land that was +taken from them a land claim so they had + + align:start position:0% +taken from them a land claim so they had + + + align:start position:0% +taken from them a land claim so they had +up until 1978 to make a claim but since + + align:start position:0% +up until 1978 to make a claim but since + + + align:start position:0% +up until 1978 to make a claim but since +then the land Claims Commission has been + + align:start position:0% + + + + align:start position:0% + +closed my concern where I come from is + + align:start position:0% +closed my concern where I come from is + + + align:start position:0% +closed my concern where I come from is +this big West + + align:start position:0% +this big West + + + align:start position:0% +this big West +this big this is all Sue but it's the + + align:start position:0% +this big this is all Sue but it's the + + + align:start position:0% +this big this is all Sue but it's the +Western half of the where the Missouri + + align:start position:0% +Western half of the where the Missouri + + + align:start position:0% +Western half of the where the Missouri +River is but you can see all these + + align:start position:0% +River is but you can see all these + + + align:start position:0% +River is but you can see all these +different land areas and there are some + + align:start position:0% +different land areas and there are some + + + align:start position:0% +different land areas and there are some +legal uh ramifications to the + + align:start position:0% +legal uh ramifications to the + + + align:start position:0% +legal uh ramifications to the +identifying these things because they're + + align:start position:0% +identifying these things because they're + + + align:start position:0% +identifying these things because they're +actually Geor referencing people so they + + align:start position:0% +actually Geor referencing people so they + + + align:start position:0% +actually Geor referencing people so they +can make claims in repatriating + + align:start position:0% +can make claims in repatriating + + + align:start position:0% +can make claims in repatriating +artifacts and human human uh + + align:start position:0% +artifacts and human human uh + + + align:start position:0% +artifacts and human human uh +uh humans back out of museums so that's + + align:start position:0% +uh humans back out of museums so that's + + + align:start position:0% +uh humans back out of museums so that's +a this is this map really plays an + + align:start position:0% +a this is this map really plays an + + + align:start position:0% +a this is this map really plays an +important part in Native people making + + align:start position:0% +important part in Native people making + + + align:start position:0% +important part in Native people making +claims in + + align:start position:0% +claims in + + + align:start position:0% +claims in +repatriation because it tells of a a + + align:start position:0% +repatriation because it tells of a a + + + align:start position:0% +repatriation because it tells of a a +geographic area where they came from if + + align:start position:0% +geographic area where they came from if + + + align:start position:0% +geographic area where they came from if +an artifact was found from there so but + + align:start position:0% +an artifact was found from there so but + + + align:start position:0% +an artifact was found from there so but +that's one of the applications I + + align:start position:0% +that's one of the applications I + + + align:start position:0% +that's one of the applications I +developed for using GIS you know is + + align:start position:0% +developed for using GIS you know is + + + align:start position:0% +developed for using GIS you know is +actually referring back to this map so + + align:start position:0% +actually referring back to this map so + + + align:start position:0% +actually referring back to this map so +this has been a very helpful map but it + + align:start position:0% +this has been a very helpful map but it + + + align:start position:0% +this has been a very helpful map but it +makes native people sort of angry to + + align:start position:0% +makes native people sort of angry to + + + align:start position:0% +makes native people sort of angry to +realize that someone else identified + + align:start position:0% +realize that someone else identified + + + align:start position:0% +realize that someone else identified +their their Aboriginal areas but there + + align:start position:0% +their their Aboriginal areas but there + + + align:start position:0% +their their Aboriginal areas but there +again that's that's I said that's that's + + align:start position:0% +again that's that's I said that's that's + + + align:start position:0% +again that's that's I said that's that's +for you to see that and go ahead and and + + align:start position:0% +for you to see that and go ahead and and + + + align:start position:0% +for you to see that and go ahead and and +re-identify it again here's an + + align:start position:0% +re-identify it again here's an + + + align:start position:0% +re-identify it again here's an +interesting one the + + align:start position:0% +interesting one the + + + align:start position:0% +interesting one the +pony their Aboriginal territory see all + + align:start position:0% +pony their Aboriginal territory see all + + + align:start position:0% +pony their Aboriginal territory see all +these arbitrary straight lines and it's + + align:start position:0% +these arbitrary straight lines and it's + + + align:start position:0% +these arbitrary straight lines and it's +nowhere like that if you listen to it a + + align:start position:0% +nowhere like that if you listen to it a + + + align:start position:0% +nowhere like that if you listen to it a +Pon all about their their Aboriginal + + align:start position:0% +Pon all about their their Aboriginal + + + align:start position:0% +Pon all about their their Aboriginal +territory good friend of mine Walter + + align:start position:0% +territory good friend of mine Walter + + + align:start position:0% +territory good friend of mine Walter +echohawk he said our Aboriginal + + align:start position:0% +echohawk he said our Aboriginal + + + align:start position:0% +echohawk he said our Aboriginal +territory was defined by these four + + align:start position:0% +territory was defined by these four + + + align:start position:0% +territory was defined by these four +stars wherever you can go in this this + + align:start position:0% +stars wherever you can go in this this + + + align:start position:0% +stars wherever you can go in this this +land and if you still seen those four + + align:start position:0% +land and if you still seen those four + + + align:start position:0% +land and if you still seen those four +stars you knew that you're you're in + + align:start position:0% +stars you knew that you're you're in + + + align:start position:0% +stars you knew that you're you're in +your your your Homeland once you didn't + + align:start position:0% +your your your Homeland once you didn't + + + align:start position:0% +your your your Homeland once you didn't +see that star you knew you were in + + align:start position:0% +see that star you knew you were in + + + align:start position:0% +see that star you knew you were in +trouble you might have been in Lakota + + align:start position:0% +trouble you might have been in Lakota + + + align:start position:0% +trouble you might have been in Lakota +territory he said but no we have + + align:start position:0% +territory he said but no we have + + + align:start position:0% +territory he said but no we have +different ways of identifying where we + + align:start position:0% +different ways of identifying where we + + + align:start position:0% +different ways of identifying where we +live you know and that that I thought + + align:start position:0% +live you know and that that I thought + + + align:start position:0% +live you know and that that I thought +that was interesting because the paon + + align:start position:0% +that was interesting because the paon + + + align:start position:0% +that was interesting because the paon +they they still have a star map that + + align:start position:0% +they they still have a star map that + + + align:start position:0% +they they still have a star map that +they relate to you know so they there + + align:start position:0% +they relate to you know so they there + + + align:start position:0% +they relate to you know so they there +are this connection that identify people + + align:start position:0% +are this connection that identify people + + + align:start position:0% +are this connection that identify people +to the land but also to the heavens and + + align:start position:0% +to the land but also to the heavens and + + + align:start position:0% +to the land but also to the heavens and +I'm going to get into that about some of + + align:start position:0% +I'm going to get into that about some of + + + align:start position:0% +I'm going to get into that about some of +our traditional + + align:start position:0% + + + + align:start position:0% + +knowledge uh this is my part of the + + align:start position:0% +knowledge uh this is my part of the + + + align:start position:0% +knowledge uh this is my part of the +world Lakota country the great Sue + + align:start position:0% +world Lakota country the great Sue + + + align:start position:0% +world Lakota country the great Sue +reservation and at one time the Treaty + + align:start position:0% +reservation and at one time the Treaty + + + align:start position:0% +reservation and at one time the Treaty +of + + align:start position:0% +of + + + align:start position:0% +of +1868 identified this whole + + align:start position:0% +1868 identified this whole + + + align:start position:0% +1868 identified this whole +area as Lota + + align:start position:0% +area as Lota + + + align:start position:0% +area as Lota +country But there again all of a sudden + + align:start position:0% +country But there again all of a sudden + + + align:start position:0% +country But there again all of a sudden +you see these arbitrary + + align:start position:0% +you see these arbitrary + + + align:start position:0% +you see these arbitrary +lines to me that that identifies a clash + + align:start position:0% +lines to me that that identifies a clash + + + align:start position:0% +lines to me that that identifies a clash +in cultures when you start seeing + + align:start position:0% +in cultures when you start seeing + + + align:start position:0% +in cultures when you start seeing +Geographic products like + + align:start position:0% +Geographic products like + + + align:start position:0% +Geographic products like +that I and we still contend that this + + align:start position:0% +that I and we still contend that this + + + align:start position:0% +that I and we still contend that this +treaty goes up to the Eastern Bank of + + align:start position:0% +treaty goes up to the Eastern Bank of + + + align:start position:0% +treaty goes up to the Eastern Bank of +the Missouri River and that's ours the + + align:start position:0% +the Missouri River and that's ours the + + + align:start position:0% +the Missouri River and that's ours the +Missouri River and according to this + + align:start position:0% +Missouri River and according to this + + + align:start position:0% +Missouri River and according to this +treaty so we're still fighting that with + + align:start position:0% +treaty so we're still fighting that with + + + align:start position:0% +treaty so we're still fighting that with +the federal government and the + + align:start position:0% +the federal government and the + + + align:start position:0% +the federal government and the +definitions and terminology of our + + align:start position:0% +definitions and terminology of our + + + align:start position:0% +definitions and terminology of our +treaties so this boundary shifts and + + align:start position:0% +treaties so this boundary shifts and + + + align:start position:0% +treaties so this boundary shifts and +changes all the time so this is another + + align:start position:0% +changes all the time so this is another + + + align:start position:0% +changes all the time so this is another +thing I talk to students about about why + + align:start position:0% +thing I talk to students about about why + + + align:start position:0% +thing I talk to students about about why +we need to use Technologies to + + align:start position:0% +we need to use Technologies to + + + align:start position:0% +we need to use Technologies to +understand the Dynamics of that + + align:start position:0% +understand the Dynamics of that + + + align:start position:0% +understand the Dynamics of that +River because it's part of our treaty + + align:start position:0% +River because it's part of our treaty + + + align:start position:0% +River because it's part of our treaty +it's part of our relationship with the + + align:start position:0% +it's part of our relationship with the + + + align:start position:0% +it's part of our relationship with the +federal + + align:start position:0% + + + + align:start position:0% + +government but also you can see all the + + align:start position:0% +government but also you can see all the + + + align:start position:0% +government but also you can see all the +legislative actions that happened + + align:start position:0% +legislative actions that happened + + + align:start position:0% +legislative actions that happened +uh and this is eventually what we ended + + align:start position:0% +uh and this is eventually what we ended + + + align:start position:0% +uh and this is eventually what we ended +up with the yellow here these + + align:start position:0% +up with the yellow here these + + + align:start position:0% +up with the yellow here these +reservations but all that land was + + align:start position:0% +reservations but all that land was + + + align:start position:0% +reservations but all that land was +eventually taken away from us although + + align:start position:0% +eventually taken away from us although + + + align:start position:0% +eventually taken away from us although +it was negotiated in the first + + align:start position:0% + + + + align:start position:0% + +treaty this is more of the reality about + + align:start position:0% +treaty this is more of the reality about + + + align:start position:0% +treaty this is more of the reality about +some of the things that are related to + + align:start position:0% +some of the things that are related to + + + align:start position:0% +some of the things that are related to +land and tribal government and our + + align:start position:0% +land and tribal government and our + + + align:start position:0% +land and tribal government and our +existence today + + align:start position:0% + + + + align:start position:0% + +is this General allotment act and I'm + + align:start position:0% +is this General allotment act and I'm + + + align:start position:0% +is this General allotment act and I'm +going to show you another graphic + + align:start position:0% +going to show you another graphic + + + align:start position:0% +going to show you another graphic +regarding that but it's where we never + + align:start position:0% +regarding that but it's where we never + + + align:start position:0% +regarding that but it's where we never +had the concept of uh of uh individual + + align:start position:0% +had the concept of uh of uh individual + + + align:start position:0% +had the concept of uh of uh individual +land + + align:start position:0% +land + + + align:start position:0% +land +ownership we believe that we are part of + + align:start position:0% +ownership we believe that we are part of + + + align:start position:0% +ownership we believe that we are part of +the land and we didn't even believe we + + align:start position:0% +the land and we didn't even believe we + + + align:start position:0% +the land and we didn't even believe we +owned the land then all of a sudden + + align:start position:0% +owned the land then all of a sudden + + + align:start position:0% +owned the land then all of a sudden +we're being forced into owning + + align:start position:0% +we're being forced into owning + + + align:start position:0% +we're being forced into owning +land so what they did was they what + + align:start position:0% +land so what they did was they what + + + align:start position:0% +land so what they did was they what +reservation was left they had this + + align:start position:0% +reservation was left they had this + + + align:start position:0% +reservation was left they had this +General lotman act it's called The + + align:start position:0% +General lotman act it's called The + + + align:start position:0% +General lotman act it's called The +Howard wheeler act that actually + + align:start position:0% +Howard wheeler act that actually + + + align:start position:0% +Howard wheeler act that actually +gave head of households and adults of a + + align:start position:0% +gave head of households and adults of a + + + align:start position:0% +gave head of households and adults of a +certain age 160 + + align:start position:0% +certain age 160 + + + align:start position:0% +certain age 160 +Acres interesting we weren't that many + + align:start position:0% +Acres interesting we weren't that many + + + align:start position:0% +Acres interesting we weren't that many +people then but think of all the land + + align:start position:0% +people then but think of all the land + + + align:start position:0% +people then but think of all the land +that was left over they opened it up to + + align:start position:0% +that was left over they opened it up to + + + align:start position:0% +that was left over they opened it up to +homesteading so that's how we lost a lot + + align:start position:0% +homesteading so that's how we lost a lot + + + align:start position:0% +homesteading so that's how we lost a lot +of our land that was one example here + + align:start position:0% +of our land that was one example here + + + align:start position:0% +of our land that was one example here +uh how we lost + + align:start position:0% +uh how we lost + + + align:start position:0% +uh how we lost +land and a lot of people don't realize + + align:start position:0% +land and a lot of people don't realize + + + align:start position:0% +land and a lot of people don't realize +that in 1924 they finally decided that + + align:start position:0% +that in 1924 they finally decided that + + + align:start position:0% +that in 1924 they finally decided that +we weren't second class citizens and you + + align:start position:0% +we weren't second class citizens and you + + + align:start position:0% +we weren't second class citizens and you +got the right to vote you + + align:start position:0% +got the right to vote you + + + align:start position:0% +got the right to vote you +know what does that tell you in your + + align:start position:0% +know what does that tell you in your + + + align:start position:0% +know what does that tell you in your +history you know those are things that + + align:start position:0% +history you know those are things that + + + align:start position:0% +history you know those are things that +we we we know in our history is that we + + align:start position:0% +we we we know in our history is that we + + + align:start position:0% +we we we know in our history is that we +weren't citizens of this great country + + align:start position:0% +weren't citizens of this great country + + + align:start position:0% +weren't citizens of this great country +until + + align:start position:0% +until + + + align:start position:0% +until +then and then we had the reorganization + + align:start position:0% +then and then we had the reorganization + + + align:start position:0% +then and then we had the reorganization +act that imposed the former government + + align:start position:0% +act that imposed the former government + + + align:start position:0% +act that imposed the former government +on us in + + align:start position:0% +on us in + + + align:start position:0% +on us in +1934 so today we still exist in chaos + + align:start position:0% +1934 so today we still exist in chaos + + + align:start position:0% +1934 so today we still exist in chaos +with the form of government that is + + align:start position:0% +with the form of government that is + + + align:start position:0% +with the form of government that is +really traditionally not + + align:start position:0% +really traditionally not + + + align:start position:0% +really traditionally not +ours I think the founding thing that + + align:start position:0% +ours I think the founding thing that + + + align:start position:0% +ours I think the founding thing that +keeps us together is our traditions and + + align:start position:0% +keeps us together is our traditions and + + + align:start position:0% +keeps us together is our traditions and +customs but we have an administrative + + align:start position:0% +customs but we have an administrative + + + align:start position:0% +customs but we have an administrative +government that deals with federal + + align:start position:0% +government that deals with federal + + + align:start position:0% +government that deals with federal +government at that + + align:start position:0% +government at that + + + align:start position:0% +government at that +level so we're talking about you know I + + align:start position:0% +level so we're talking about you know I + + + align:start position:0% +level so we're talking about you know I +guess we we say conflict resolution but + + align:start position:0% +guess we we say conflict resolution but + + + align:start position:0% +guess we we say conflict resolution but +we're trying to merge these two forms of + + align:start position:0% +we're trying to merge these two forms of + + + align:start position:0% +we're trying to merge these two forms of +government together and very often you + + align:start position:0% +government together and very often you + + + align:start position:0% +government together and very often you +find uh people that are culturally + + align:start position:0% +find uh people that are culturally + + + align:start position:0% +find uh people that are culturally +founded to be uh councilmen so that + + align:start position:0% +founded to be uh councilmen so that + + + align:start position:0% +founded to be uh councilmen so that +happens on many different occasions but + + align:start position:0% +happens on many different occasions but + + + align:start position:0% +happens on many different occasions but +this reorganization act has + + align:start position:0% +this reorganization act has + + + align:start position:0% +this reorganization act has +a a stipulation that you know in in the + + align:start position:0% +a a stipulation that you know in in the + + + align:start position:0% +a a stipulation that you know in in the +Conti ution of our our tribe says we can + + align:start position:0% +Conti ution of our our tribe says we can + + + align:start position:0% +Conti ution of our our tribe says we can +only have elections every two + + align:start position:0% +only have elections every two + + + align:start position:0% +only have elections every two +years so you can imagine the turnover in + + align:start position:0% +years so you can imagine the turnover in + + + align:start position:0% +years so you can imagine the turnover in +our government so it's just major chaos + + align:start position:0% +our government so it's just major chaos + + + align:start position:0% +our government so it's just major chaos +but a lot of tribes right now are + + align:start position:0% +but a lot of tribes right now are + + + align:start position:0% +but a lot of tribes right now are +revising their their uh constitutions to + + align:start position:0% +revising their their uh constitutions to + + + align:start position:0% +revising their their uh constitutions to +to react towards you know being more uh + + align:start position:0% +to react towards you know being more uh + + + align:start position:0% +to react towards you know being more uh +I guess uh proactive in their their uh + + align:start position:0% +I guess uh proactive in their their uh + + + align:start position:0% +I guess uh proactive in their their uh +future there's all these other acts here + + align:start position:0% +future there's all these other acts here + + + align:start position:0% +future there's all these other acts here +that that really affect us that you + + align:start position:0% +that that really affect us that you + + + align:start position:0% +that that really affect us that you +don't really understand and know but + + align:start position:0% +don't really understand and know but + + + align:start position:0% +don't really understand and know but +then these preservation acts + + align:start position:0% +then these preservation acts + + + align:start position:0% +then these preservation acts +environmental policies + + align:start position:0% +environmental policies + + + align:start position:0% +environmental policies +they really involve what they call uh + + align:start position:0% +they really involve what they call uh + + + align:start position:0% +they really involve what they call uh +Native American + + align:start position:0% +Native American + + + align:start position:0% +Native American +consultation it's sort of like the trust + + align:start position:0% +consultation it's sort of like the trust + + + align:start position:0% +consultation it's sort of like the trust +responsibility of federal government to + + align:start position:0% +responsibility of federal government to + + + align:start position:0% +responsibility of federal government to +really seek and and uh look for input + + align:start position:0% +really seek and and uh look for input + + + align:start position:0% +really seek and and uh look for input +from native people so I think those are + + align:start position:0% +from native people so I think those are + + + align:start position:0% +from native people so I think those are +the things that we're talking about here + + align:start position:0% +the things that we're talking about here + + + align:start position:0% +the things that we're talking about here +in this policy Environmental Policy + + align:start position:0% +in this policy Environmental Policy + + + align:start position:0% +in this policy Environmental Policy +places how to create some kind of + + align:start position:0% +places how to create some kind of + + + align:start position:0% +places how to create some kind of +synergy for people to be to sit at a + + align:start position:0% +synergy for people to be to sit at a + + + align:start position:0% +synergy for people to be to sit at a +table and and talk right now you know + + align:start position:0% +table and and talk right now you know + + + align:start position:0% +table and and talk right now you know +that that that isn't so prevalent in + + align:start position:0% +that that that isn't so prevalent in + + + align:start position:0% +that that that isn't so prevalent in +Indian country a lot of times we have to + + align:start position:0% +Indian country a lot of times we have to + + + align:start position:0% +Indian country a lot of times we have to +go somewhere no one ever comes to us you + + align:start position:0% +go somewhere no one ever comes to us you + + + align:start position:0% +go somewhere no one ever comes to us you +know so we got to find a happy medium + + align:start position:0% +know so we got to find a happy medium + + + align:start position:0% +know so we got to find a happy medium +there and I I I don't like the word + + align:start position:0% +there and I I I don't like the word + + + align:start position:0% +there and I I I don't like the word +conflict resolution but there there + + align:start position:0% +conflict resolution but there there + + + align:start position:0% +conflict resolution but there there +seems to be that that stands in a way + + align:start position:0% +seems to be that that stands in a way + + + align:start position:0% +seems to be that that stands in a way +you know but we are by law supposed to + + align:start position:0% +you know but we are by law supposed to + + + align:start position:0% +you know but we are by law supposed to +be + + align:start position:0% + + + + align:start position:0% + +consulted uh like I mentioned 1975 the + + align:start position:0% +consulted uh like I mentioned 1975 the + + + align:start position:0% +consulted uh like I mentioned 1975 the +education assistant act 30 years ago + + align:start position:0% +education assistant act 30 years ago + + + align:start position:0% +education assistant act 30 years ago +uh actually that that was uh under that + + align:start position:0% +uh actually that that was uh under that + + + align:start position:0% +uh actually that that was uh under that +was the mix + + align:start position:0% + + + + align:start position:0% + +Administration native people didn't you + + align:start position:0% +Administration native people didn't you + + + align:start position:0% +Administration native people didn't you +know didn't mind that uh Nixon and his + + align:start position:0% +know didn't mind that uh Nixon and his + + + align:start position:0% +know didn't mind that uh Nixon and his +administration got more of the funding + + align:start position:0% +administration got more of the funding + + + align:start position:0% +administration got more of the funding +directly to us rather through the Bureau + + align:start position:0% +directly to us rather through the Bureau + + + align:start position:0% +directly to us rather through the Bureau +of intern Affairs at that time the + + align:start position:0% +of intern Affairs at that time the + + + align:start position:0% +of intern Affairs at that time the +statistics were 30 cents out of every + + align:start position:0% +statistics were 30 cents out of every + + + align:start position:0% +statistics were 30 cents out of every +dollar finally got to the tribal agency + + align:start position:0% +dollar finally got to the tribal agency + + + align:start position:0% +dollar finally got to the tribal agency +because of the administ trivia but but + + align:start position:0% +because of the administ trivia but but + + + align:start position:0% +because of the administ trivia but but +now we got more funding coming to our + + align:start position:0% +now we got more funding coming to our + + + align:start position:0% +now we got more funding coming to our +tribal government directly and the + + align:start position:0% +tribal government directly and the + + + align:start position:0% +tribal government directly and the +education assistant act allowed us to to + + align:start position:0% +education assistant act allowed us to to + + + align:start position:0% +education assistant act allowed us to to +start moving into the tribal College + + align:start position:0% +start moving into the tribal College + + + align:start position:0% +start moving into the tribal College +movement and here's another kicker that + + align:start position:0% +movement and here's another kicker that + + + align:start position:0% +movement and here's another kicker that +most people don't know it's been our + + align:start position:0% +most people don't know it's been our + + + align:start position:0% +most people don't know it's been our +reality is that how this country was + + align:start position:0% +reality is that how this country was + + + align:start position:0% +reality is that how this country was +founded on religious freedom but + + align:start position:0% +founded on religious freedom but + + + align:start position:0% +founded on religious freedom but +fortunately we weren't guaranteed our + + align:start position:0% +fortunately we weren't guaranteed our + + + align:start position:0% +fortunately we weren't guaranteed our +religious freedom as Native Americans + + align:start position:0% +religious freedom as Native Americans + + + align:start position:0% +religious freedom as Native Americans +until + + align:start position:0% + + + + align:start position:0% + +1978 and that was uh one of the first + + align:start position:0% +1978 and that was uh one of the first + + + align:start position:0% +1978 and that was uh one of the first +things that the Native American rights + + align:start position:0% +things that the Native American rights + + + align:start position:0% +things that the Native American rights +fund really fought for was our our + + align:start position:0% +fund really fought for was our our + + + align:start position:0% +fund really fought for was our our +religious freedom in fact right now + + align:start position:0% +religious freedom in fact right now + + + align:start position:0% +religious freedom in fact right now +there are still fights going on right + + align:start position:0% +there are still fights going on right + + + align:start position:0% +there are still fights going on right +now regarding the Native American church + + align:start position:0% +now regarding the Native American church + + + align:start position:0% +now regarding the Native American church +and the use of of + + align:start position:0% +and the use of of + + + align:start position:0% +and the use of of +peyote as a Sacrament so we're still + + align:start position:0% +peyote as a Sacrament so we're still + + + align:start position:0% +peyote as a Sacrament so we're still +fighting for our rights regarding + + align:start position:0% +fighting for our rights regarding + + + align:start position:0% +fighting for our rights regarding +religious freedom but you can see all + + align:start position:0% +religious freedom but you can see all + + + align:start position:0% +religious freedom but you can see all +these different kind of Acts that that + + align:start position:0% +these different kind of Acts that that + + + align:start position:0% +these different kind of Acts that that +that that sort of + + align:start position:0% +that that sort of + + + align:start position:0% +that that sort of +uh have us + + align:start position:0% +uh have us + + + align:start position:0% +uh have us +in having to be more + + align:start position:0% +in having to be more + + + align:start position:0% +in having to be more +proactive so I I think at the tribal + + align:start position:0% +proactive so I I think at the tribal + + + align:start position:0% +proactive so I I think at the tribal +College I mean where I'm involved and I + + align:start position:0% +College I mean where I'm involved and I + + + align:start position:0% +College I mean where I'm involved and I +see government tribal government is so + + align:start position:0% +see government tribal government is so + + + align:start position:0% +see government tribal government is so +reactive because they have so many + + align:start position:0% +reactive because they have so many + + + align:start position:0% +reactive because they have so many +priorities that there again the tribal + + align:start position:0% +priorities that there again the tribal + + + align:start position:0% +priorities that there again the tribal +college has to prepare a whole level a + + align:start position:0% +college has to prepare a whole level a + + + align:start position:0% +college has to prepare a whole level a +whole Cadre of um of new leaders to + + align:start position:0% +whole Cadre of um of new leaders to + + + align:start position:0% +whole Cadre of um of new leaders to +react to these kind of uh authorities so + + align:start position:0% +react to these kind of uh authorities so + + + align:start position:0% +react to these kind of uh authorities so +we can still uphold our end of the + + align:start position:0% +we can still uphold our end of the + + + align:start position:0% +we can still uphold our end of the +treaties that we still have in place + + align:start position:0% +treaties that we still have in place + + + align:start position:0% +treaties that we still have in place +well you can't believe we're very + + align:start position:0% +well you can't believe we're very + + + align:start position:0% +well you can't believe we're very +faithful to those + + align:start position:0% +faithful to those + + + align:start position:0% +faithful to those +treaties these things are things that + + align:start position:0% +treaties these things are things that + + + align:start position:0% +treaties these things are things that +really keep our relationship going if it + + align:start position:0% +really keep our relationship going if it + + + align:start position:0% +really keep our relationship going if it +if it weren't for these kind of + + align:start position:0% +if it weren't for these kind of + + + align:start position:0% +if it weren't for these kind of +authorities and our treaties I really + + align:start position:0% +authorities and our treaties I really + + + align:start position:0% +authorities and our treaties I really +wonder what would happen to Native + + align:start position:0% +wonder what would happen to Native + + + align:start position:0% +wonder what would happen to Native +people because at one time we were + + align:start position:0% +people because at one time we were + + + align:start position:0% +people because at one time we were +administered to the Department of + + align:start position:0% +administered to the Department of + + + align:start position:0% +administered to the Department of +War you know that's our + + align:start position:0% +War you know that's our + + + align:start position:0% +War you know that's our +reality a joke I always tell was you + + align:start position:0% +reality a joke I always tell was you + + + align:start position:0% +reality a joke I always tell was you +heard of General kuster technically at + + align:start position:0% +heard of General kuster technically at + + + align:start position:0% +heard of General kuster technically at +that time the the native people were + + align:start position:0% +that time the the native people were + + + align:start position:0% +that time the the native people were +being administered under the Bureau of I + + align:start position:0% +being administered under the Bureau of I + + + align:start position:0% +being administered under the Bureau of I +mean under the department of War so he + + align:start position:0% +mean under the department of War so he + + + align:start position:0% +mean under the department of War so he +was technically the head of the the + + align:start position:0% +was technically the head of the the + + + align:start position:0% +was technically the head of the the +Bureau of Indian + + align:start position:0% +Bureau of Indian + + + align:start position:0% +Bureau of Indian +Affairs and he said don't do anything + + align:start position:0% +Affairs and he said don't do anything + + + align:start position:0% +Affairs and he said don't do anything +till I get back of course he never got + + align:start position:0% +till I get back of course he never got + + + align:start position:0% +till I get back of course he never got +back + + align:start position:0% + + + + align:start position:0% + +you never made it back from the Little + + align:start position:0% +you never made it back from the Little + + + align:start position:0% +you never made it back from the Little +Big + + align:start position:0% + + + + align:start position:0% + +Horn + + align:start position:0% +Horn + + + align:start position:0% +Horn +uh that allotment Act and the Homestead + + align:start position:0% +uh that allotment Act and the Homestead + + + align:start position:0% +uh that allotment Act and the Homestead +Acts all those legislative actions that + + align:start position:0% +Acts all those legislative actions that + + + align:start position:0% +Acts all those legislative actions that +were in violation of our treaties but + + align:start position:0% +were in violation of our treaties but + + + align:start position:0% +were in violation of our treaties but +still today we can't really fuss about + + align:start position:0% +still today we can't really fuss about + + + align:start position:0% +still today we can't really fuss about +that but we're left with the reality + + align:start position:0% +that but we're left with the reality + + + align:start position:0% +that but we're left with the reality +of uh if you could look at the the + + align:start position:0% +of uh if you could look at the the + + + align:start position:0% +of uh if you could look at the the +the the index here uh there's a lot of + + align:start position:0% +the the index here uh there's a lot of + + + align:start position:0% +the the index here uh there's a lot of +lands are in the + + align:start position:0% +lands are in the + + + align:start position:0% +lands are in the +blue and uh tribal Reserve lands here in + + align:start position:0% +blue and uh tribal Reserve lands here in + + + align:start position:0% +blue and uh tribal Reserve lands here in +the + + align:start position:0% +the + + + align:start position:0% +the +green tribal uh other lands in the light + + align:start position:0% +green tribal uh other lands in the light + + + align:start position:0% +green tribal uh other lands in the light +green and this used to be our whole + + align:start position:0% +green and this used to be our whole + + + align:start position:0% +green and this used to be our whole +reservation but then through other + + align:start position:0% +reservation but then through other + + + align:start position:0% +reservation but then through other +through the Homestead Act we + + align:start position:0% +through the Homestead Act we + + + align:start position:0% +through the Homestead Act we +lost and this is all we have today on + + align:start position:0% +lost and this is all we have today on + + + align:start position:0% +lost and this is all we have today on +the uh Rosebud Sue reservation you can + + align:start position:0% +the uh Rosebud Sue reservation you can + + + align:start position:0% +the uh Rosebud Sue reservation you can +see that here in the scale of South + + align:start position:0% +see that here in the scale of South + + + align:start position:0% +see that here in the scale of South +Dakota that whole area that we lost is + + align:start position:0% +Dakota that whole area that we lost is + + + align:start position:0% +Dakota that whole area that we lost is +down to this but this is our reality + + align:start position:0% +down to this but this is our reality + + + align:start position:0% +down to this but this is our reality +this is what we have to use and + + align:start position:0% +this is what we have to use and + + + align:start position:0% +this is what we have to use and +manage many mil + + align:start position:0% +manage many mil + + + align:start position:0% +manage many mil +uh okay I'll say a about + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +100 there's about 400 square miles here + + align:start position:0% +100 there's about 400 square miles here + + + align:start position:0% +100 there's about 400 square miles here +approximately + + align:start position:0% +approximately + + + align:start position:0% +approximately +yeah but that that that's our realities + + align:start position:0% +yeah but that that that's our realities + + + align:start position:0% +yeah but that that that's our realities +and how checkerboard that is but our our + + align:start position:0% +and how checkerboard that is but our our + + + align:start position:0% +and how checkerboard that is but our our +culture is really tied to this land base + + align:start position:0% +culture is really tied to this land base + + + align:start position:0% +culture is really tied to this land base +not only here that's today but we're + + align:start position:0% +not only here that's today but we're + + + align:start position:0% +not only here that's today but we're +also connected to the Black Hills of + + align:start position:0% +also connected to the Black Hills of + + + align:start position:0% +also connected to the Black Hills of +South Dakota Western South Dakota this + + align:start position:0% +South Dakota Western South Dakota this + + + align:start position:0% +South Dakota Western South Dakota this +whole area like that where we still a + + align:start position:0% +whole area like that where we still a + + + align:start position:0% +whole area like that where we still a +lot of those authorities I mentioned + + align:start position:0% +lot of those authorities I mentioned + + + align:start position:0% +lot of those authorities I mentioned +have us connected to there so it wasn't + + align:start position:0% +have us connected to there so it wasn't + + + align:start position:0% +have us connected to there so it wasn't +for those authorities like the + + align:start position:0% +for those authorities like the + + + align:start position:0% +for those authorities like the +archaeological resource protection act + + align:start position:0% +archaeological resource protection act + + + align:start position:0% +archaeological resource protection act +and the Native American Graves + + align:start position:0% +and the Native American Graves + + + align:start position:0% +and the Native American Graves +protection and repatriation act Clean + + align:start position:0% +protection and repatriation act Clean + + + align:start position:0% +protection and repatriation act Clean +Air Act all these kind of things keep us + + align:start position:0% +Air Act all these kind of things keep us + + + align:start position:0% +Air Act all these kind of things keep us +connected to that whole uh greater + + align:start position:0% +connected to that whole uh greater + + + align:start position:0% +connected to that whole uh greater +Aboriginal + + align:start position:0% +Aboriginal + + + align:start position:0% +Aboriginal +territory here's some pictures of our + + align:start position:0% +territory here's some pictures of our + + + align:start position:0% +territory here's some pictures of our +reservation now I just took that a few + + align:start position:0% +reservation now I just took that a few + + + align:start position:0% +reservation now I just took that a few +days ago that's how beautiful it is we + + align:start position:0% +days ago that's how beautiful it is we + + + align:start position:0% +days ago that's how beautiful it is we +had a nice spring so these uh these this + + align:start position:0% +had a nice spring so these uh these this + + + align:start position:0% +had a nice spring so these uh these this +is The Little White River it's running + + align:start position:0% +is The Little White River it's running + + + align:start position:0% +is The Little White River it's running +pretty + + align:start position:0% +pretty + + + align:start position:0% +pretty +full and the grass lands of grass is + + align:start position:0% +full and the grass lands of grass is + + + align:start position:0% +full and the grass lands of grass is +nice and + + align:start position:0% +nice and + + + align:start position:0% +nice and +Tall over here you can see the topology + + align:start position:0% +Tall over here you can see the topology + + + align:start position:0% +Tall over here you can see the topology +we have some of the bad lands and we + + align:start position:0% +we have some of the bad lands and we + + + align:start position:0% +we have some of the bad lands and we +have uh the Prairies and there's deer + + align:start position:0% +have uh the Prairies and there's deer + + + align:start position:0% +have uh the Prairies and there's deer +standing out there but it's a really + + align:start position:0% +standing out there but it's a really + + + align:start position:0% +standing out there but it's a really +beautiful area you know it's uh our + + align:start position:0% +beautiful area you know it's uh our + + + align:start position:0% +beautiful area you know it's uh our +homeland but yet uh it's almost like an + + align:start position:0% +homeland but yet uh it's almost like an + + + align:start position:0% +homeland but yet uh it's almost like an +island and the sad thing about it is + + align:start position:0% +island and the sad thing about it is + + + align:start position:0% +island and the sad thing about it is +that a lot of people fall fall into that + + align:start position:0% +that a lot of people fall fall into that + + + align:start position:0% +that a lot of people fall fall into that +political boundary and they they don't + + align:start position:0% +political boundary and they they don't + + + align:start position:0% +political boundary and they they don't +realize what's happening out here in the + + align:start position:0% +realize what's happening out here in the + + + align:start position:0% +realize what's happening out here in the +greater + + align:start position:0% +greater + + + align:start position:0% +greater +World they again that's why the tribal + + align:start position:0% +World they again that's why the tribal + + + align:start position:0% +World they again that's why the tribal +colleges for who we are really are + + align:start position:0% +colleges for who we are really are + + + align:start position:0% +colleges for who we are really are +trying to make those connections for our + + align:start position:0% +trying to make those connections for our + + + align:start position:0% +trying to make those connections for our +students in the future Aboriginal + + align:start position:0% +students in the future Aboriginal + + + align:start position:0% +students in the future Aboriginal +Homeland is really one of those things + + align:start position:0% +Homeland is really one of those things + + + align:start position:0% +Homeland is really one of those things +that we're trying to bring back as a + + align:start position:0% +that we're trying to bring back as a + + + align:start position:0% +that we're trying to bring back as a +concept looking at the vested interest + + align:start position:0% +concept looking at the vested interest + + + align:start position:0% +concept looking at the vested interest +in the whole area how that can really + + align:start position:0% +in the whole area how that can really + + + align:start position:0% +in the whole area how that can really +benefit us and be what you call + + align:start position:0% + + + + align:start position:0% + +metaphorically in our Homeland to be + + align:start position:0% +metaphorically in our Homeland to be + + + align:start position:0% +metaphorically in our Homeland to be +connected to it again but also + + align:start position:0% +connected to it again but also + + + align:start position:0% +connected to it again but also +be co-managers because we have that + + align:start position:0% +be co-managers because we have that + + + align:start position:0% +be co-managers because we have that +opportunity in front of us through our + + align:start position:0% +opportunity in front of us through our + + + align:start position:0% +opportunity in front of us through our +treaties to be co-managers of of federal + + align:start position:0% +treaties to be co-managers of of federal + + + align:start position:0% +treaties to be co-managers of of federal +lands because we still have land claims + + align:start position:0% +lands because we still have land claims + + + align:start position:0% +lands because we still have land claims +you know we're we're trying to regain + + align:start position:0% +you know we're we're trying to regain + + + align:start position:0% +you know we're we're trying to regain +title to the Black Hills but we know in + + align:start position:0% +title to the Black Hills but we know in + + + align:start position:0% +title to the Black Hills but we know in +reality we won't but we will do want to + + align:start position:0% +reality we won't but we will do want to + + + align:start position:0% +reality we won't but we will do want to +propose that we can be co-managers of + + align:start position:0% +propose that we can be co-managers of + + + align:start position:0% +propose that we can be co-managers of +federal land that may be more of the + + align:start position:0% +federal land that may be more of the + + + align:start position:0% +federal land that may be more of the +reality so those are things that tribal + + align:start position:0% +reality so those are things that tribal + + + align:start position:0% +reality so those are things that tribal +colleges are really uh at least we are + + align:start position:0% +colleges are really uh at least we are + + + align:start position:0% +colleges are really uh at least we are +and other uh uh Lota tribal colleges are + + align:start position:0% +and other uh uh Lota tribal colleges are + + + align:start position:0% +and other uh uh Lota tribal colleges are +looking + + align:start position:0% +looking + + + align:start position:0% +looking +at okay let me move into another next + + align:start position:0% +at okay let me move into another next + + + align:start position:0% +at okay let me move into another next +topic how we doing on + + align:start position:0% + + + + align:start position:0% + +time okay + + align:start position:0% +time okay + + + align:start position:0% +time okay +good indigenous Knowledge Center for + + align:start position:0% +good indigenous Knowledge Center for + + + align:start position:0% +good indigenous Knowledge Center for +education and science + + align:start position:0% +education and science + + + align:start position:0% +education and science +impact you know I I uh was was wrangling + + align:start position:0% +impact you know I I uh was was wrangling + + + align:start position:0% +impact you know I I uh was was wrangling +with the how to put the the words + + align:start position:0% +with the how to put the the words + + + align:start position:0% +with the how to put the the words +together for a title and and what came + + align:start position:0% +together for a title and and what came + + + align:start position:0% +together for a title and and what came +there was the acronyms ik + + align:start position:0% +there was the acronyms ik + + + align:start position:0% +there was the acronyms ik +C and all of a sudden when that stood + + align:start position:0% +C and all of a sudden when that stood + + + align:start position:0% +C and all of a sudden when that stood +out to me it was a Lota word and it said + + align:start position:0% +out to me it was a Lota word and it said + + + align:start position:0% +out to me it was a Lota word and it said +I I means a it's a value that we have + + align:start position:0% +I I means a it's a value that we have + + + align:start position:0% +I I means a it's a value that we have +which is tied to the commonality of man + + align:start position:0% +which is tied to the commonality of man + + + align:start position:0% +which is tied to the commonality of man +and self we're all common men we're all + + align:start position:0% +and self we're all common men we're all + + + align:start position:0% +and self we're all common men we're all +common + + align:start position:0% +common + + + align:start position:0% +common +women a sense of humility about who we + + align:start position:0% +women a sense of humility about who we + + + align:start position:0% +women a sense of humility about who we +are but collectively there's power in in + + align:start position:0% +are but collectively there's power in in + + + align:start position:0% +are but collectively there's power in in +our knowledge that we share it's a + + align:start position:0% +our knowledge that we share it's a + + + align:start position:0% +our knowledge that we share it's a +distributed wealth of knowledge between + + align:start position:0% +distributed wealth of knowledge between + + + align:start position:0% +distributed wealth of knowledge between +common people our experiences that we we + + align:start position:0% +common people our experiences that we we + + + align:start position:0% +common people our experiences that we we +bring + + align:start position:0% +bring + + + align:start position:0% +bring +together so when that word came out it + + align:start position:0% +together so when that word came out it + + + align:start position:0% +together so when that word came out it +just really hit me that really that's + + align:start position:0% +just really hit me that really that's + + + align:start position:0% +just really hit me that really that's +the essence of our of our science Impact + + align:start position:0% +the essence of our of our science Impact + + + align:start position:0% +the essence of our of our science Impact +Center is a collective knowledge of of + + align:start position:0% +Center is a collective knowledge of of + + + align:start position:0% +Center is a collective knowledge of of +of who we are as a + + align:start position:0% + + + + align:start position:0% + +people so I I was like really inspired + + align:start position:0% +people so I I was like really inspired + + + align:start position:0% +people so I I was like really inspired +and I think we're on to something good I + + align:start position:0% +and I think we're on to something good I + + + align:start position:0% +and I think we're on to something good I +was telling some of my other colleagues + + align:start position:0% +was telling some of my other colleagues + + + align:start position:0% +was telling some of my other colleagues +and I even ran that by some of our the + + align:start position:0% +and I even ran that by some of our the + + + align:start position:0% +and I even ran that by some of our the +tribal historian and they just grinned + + align:start position:0% +tribal historian and they just grinned + + + align:start position:0% +tribal historian and they just grinned +and smiled they said it must be good + + align:start position:0% +and smiled they said it must be good + + + align:start position:0% +and smiled they said it must be good +then but I I just thought very + + align:start position:0% +then but I I just thought very + + + align:start position:0% +then but I I just thought very +inspirational that that we were able to + + align:start position:0% +inspirational that that we were able to + + + align:start position:0% +inspirational that that we were able to +put together a concept for for the + + align:start position:0% +put together a concept for for the + + + align:start position:0% +put together a concept for for the +science impact uh + + align:start position:0% +science impact uh + + + align:start position:0% +science impact uh +program and how we can actually connect + + align:start position:0% +program and how we can actually connect + + + align:start position:0% +program and how we can actually connect +to it culturally as well and it ties in + + align:start position:0% +to it culturally as well and it ties in + + + align:start position:0% +to it culturally as well and it ties in +some of our values and our + + align:start position:0% +some of our values and our + + + align:start position:0% +some of our values and our +ideals + + align:start position:0% +ideals + + + align:start position:0% +ideals +and really kind of thought hard about + + align:start position:0% +and really kind of thought hard about + + + align:start position:0% +and really kind of thought hard about +some kind of a logo that we wanted to + + align:start position:0% +some kind of a logo that we wanted to + + + align:start position:0% +some kind of a logo that we wanted to +present with with our Center and and I + + align:start position:0% +present with with our Center and and I + + + align:start position:0% +present with with our Center and and I +remember many years ago I drew this up + + align:start position:0% +remember many years ago I drew this up + + + align:start position:0% +remember many years ago I drew this up +and it finally came out it's like yeah + + align:start position:0% +and it finally came out it's like yeah + + + align:start position:0% +and it finally came out it's like yeah +we uh this is who we are as native + + align:start position:0% +we uh this is who we are as native + + + align:start position:0% +we uh this is who we are as native +people because we really sort + + align:start position:0% +people because we really sort + + + align:start position:0% +people because we really sort +of we're not so much male Dominator + + align:start position:0% +of we're not so much male Dominator + + + align:start position:0% +of we're not so much male Dominator +we're actually a matrinal society but + + align:start position:0% +we're actually a matrinal society but + + + align:start position:0% +we're actually a matrinal society but +then we live in harmony and balance we + + align:start position:0% +then we live in harmony and balance we + + + align:start position:0% +then we live in harmony and balance we +complement one another that's + + align:start position:0% +complement one another that's + + + align:start position:0% +complement one another that's +traditionally how we we existed as a + + align:start position:0% +traditionally how we we existed as a + + + align:start position:0% +traditionally how we we existed as a +culture in gender balance so even that + + align:start position:0% +culture in gender balance so even that + + + align:start position:0% +culture in gender balance so even that +alone is says something about how we + + align:start position:0% +alone is says something about how we + + + align:start position:0% +alone is says something about how we +want to approach our business and and + + align:start position:0% +want to approach our business and and + + + align:start position:0% +want to approach our business and and +look at our Center is to really honor uh + + align:start position:0% +look at our Center is to really honor uh + + + align:start position:0% +look at our Center is to really honor uh +and have gender balance and look at the + + align:start position:0% +and have gender balance and look at the + + + align:start position:0% +and have gender balance and look at the +world in the sense of balance again too + + align:start position:0% +world in the sense of balance again too + + + align:start position:0% +world in the sense of balance again too +so so that in itself is a statement and + + align:start position:0% +so so that in itself is a statement and + + + align:start position:0% +so so that in itself is a statement and +a story about who we who we are and what + + align:start position:0% +a story about who we who we are and what + + + align:start position:0% +a story about who we who we are and what +our Center wants uh can can + + align:start position:0% + + + + align:start position:0% + +be I mention the fact that we have many + + align:start position:0% +be I mention the fact that we have many + + + align:start position:0% +be I mention the fact that we have many +partners uh we're probably the only + + align:start position:0% +partners uh we're probably the only + + + align:start position:0% +partners uh we're probably the only +tribal College as of I'd say two years + + align:start position:0% +tribal College as of I'd say two years + + + align:start position:0% +tribal College as of I'd say two years +ago that were very enterprising to go + + align:start position:0% +ago that were very enterprising to go + + + align:start position:0% +ago that were very enterprising to go +out and and start um uh developing + + align:start position:0% +out and and start um uh developing + + + align:start position:0% +out and and start um uh developing +relationships and since then we have + + align:start position:0% +relationships and since then we have + + + align:start position:0% +relationships and since then we have +written many grants we've applied for + + align:start position:0% +written many grants we've applied for + + + align:start position:0% +written many grants we've applied for +different things and funding but but + + align:start position:0% +different things and funding but but + + + align:start position:0% +different things and funding but but +some of the things that we have in place + + align:start position:0% +some of the things that we have in place + + + align:start position:0% +some of the things that we have in place +right now is by that enterprising and + + align:start position:0% +right now is by that enterprising and + + + align:start position:0% +right now is by that enterprising and +Outreach and it more or less predicated + + align:start position:0% +Outreach and it more or less predicated + + + align:start position:0% +Outreach and it more or less predicated +on this relationship with the the Aeros + + align:start position:0% +on this relationship with the the Aeros + + + align:start position:0% +on this relationship with the the Aeros +Data Center and the USGS so we have a + + align:start position:0% +Data Center and the USGS so we have a + + + align:start position:0% +Data Center and the USGS so we have a +formal mou with the USGS that we're able + + align:start position:0% +formal mou with the USGS that we're able + + + align:start position:0% +formal mou with the USGS that we're able +to uh + + align:start position:0% + + + + align:start position:0% + +leverage and also we're part of a an + + align:start position:0% +leverage and also we're part of a an + + + align:start position:0% +leverage and also we're part of a an +organization here called the Upper + + align:start position:0% +organization here called the Upper + + + align:start position:0% +organization here called the Upper +Midwest Aerospace Consortium that's led + + align:start position:0% +Midwest Aerospace Consortium that's led + + + align:start position:0% +Midwest Aerospace Consortium that's led +by uh Dr George + + align:start position:0% +by uh Dr George + + + align:start position:0% +by uh Dr George +sead and I don't know if you know him + + align:start position:0% +sead and I don't know if you know him + + + align:start position:0% +sead and I don't know if you know him +but I if if anybody I could say is an + + align:start position:0% +but I if if anybody I could say is an + + + align:start position:0% +but I if if anybody I could say is an +elder in American society that's George + + align:start position:0% +elder in American society that's George + + + align:start position:0% +elder in American society that's George +sead is one of them he's sort of a + + align:start position:0% +sead is one of them he's sort of a + + + align:start position:0% +sead is one of them he's sort of a +Visionary I'd say but he really embodies + + align:start position:0% +Visionary I'd say but he really embodies + + + align:start position:0% +Visionary I'd say but he really embodies +a lot of + + align:start position:0% +a lot of + + + align:start position:0% +a lot of +wisdom and we always figured him a smart + + align:start position:0% +wisdom and we always figured him a smart + + + align:start position:0% +wisdom and we always figured him a smart +man to invite us into our his Consortium + + align:start position:0% +man to invite us into our his Consortium + + + align:start position:0% +man to invite us into our his Consortium +so but yeah so we we have gained from + + align:start position:0% +so but yeah so we we have gained from + + + align:start position:0% +so but yeah so we we have gained from +our association with + + align:start position:0% +our association with + + + align:start position:0% +our association with +him and uh + + align:start position:0% +him and uh + + + align:start position:0% +him and uh +also + + align:start position:0% +also + + + align:start position:0% +also +we several times I don't know how many + + align:start position:0% +we several times I don't know how many + + + align:start position:0% +we several times I don't know how many +times we've been trying and and we + + align:start position:0% +times we've been trying and and we + + + align:start position:0% +times we've been trying and and we +finally broke the crack the nut in NASA + + align:start position:0% +finally broke the crack the nut in NASA + + + align:start position:0% +finally broke the crack the nut in NASA +and and got a awarded a reason can uh + + align:start position:0% +and and got a awarded a reason can uh + + + align:start position:0% +and and got a awarded a reason can uh +project so we just initiated that here + + align:start position:0% +project so we just initiated that here + + + align:start position:0% +project so we just initiated that here +the beginning of the fiscal year it took + + align:start position:0% +the beginning of the fiscal year it took + + + align:start position:0% +the beginning of the fiscal year it took +us a year to finally negotiate our + + align:start position:0% +us a year to finally negotiate our + + + align:start position:0% +us a year to finally negotiate our +budget with them because they they + + align:start position:0% +budget with them because they they + + + align:start position:0% +budget with them because they they +shaved our budget 80% but nonetheless we + + align:start position:0% +shaved our budget 80% but nonetheless we + + + align:start position:0% +shaved our budget 80% but nonetheless we +have won one of the reason can + + align:start position:0% +have won one of the reason can + + + align:start position:0% +have won one of the reason can +projects and we have ongoing uh uh uh a + + align:start position:0% +projects and we have ongoing uh uh uh a + + + align:start position:0% +projects and we have ongoing uh uh uh a +water quality project with Noah and + + align:start position:0% +water quality project with Noah and + + + align:start position:0% +water quality project with Noah and +we're getting into uh some renewable + + align:start position:0% +we're getting into uh some renewable + + + align:start position:0% +we're getting into uh some renewable +energy projects with them looking at and + + align:start position:0% +energy projects with them looking at and + + + align:start position:0% +energy projects with them looking at and +this has led us to I don't have a uh + + align:start position:0% +this has led us to I don't have a uh + + + align:start position:0% +this has led us to I don't have a uh +graphic up here but Noah has kind of + + align:start position:0% +graphic up here but Noah has kind of + + + align:start position:0% +graphic up here but Noah has kind of +introduced us to to uh Nar so we're + + align:start position:0% +introduced us to to uh Nar so we're + + + align:start position:0% +introduced us to to uh Nar so we're +getting involved there with + + align:start position:0% +getting involved there with + + + align:start position:0% +getting involved there with +enar and with uh Bob Harris he's been + + align:start position:0% +enar and with uh Bob Harris he's been + + + align:start position:0% +enar and with uh Bob Harris he's been +very + + align:start position:0% +very + + + align:start position:0% +very +helpful uh the the National Science + + align:start position:0% +helpful uh the the National Science + + + align:start position:0% +helpful uh the the National Science +Foundation uh before I started science + + align:start position:0% +Foundation uh before I started science + + + align:start position:0% +Foundation uh before I started science +impact here I I was managing a an NSF uh + + align:start position:0% +impact here I I was managing a an NSF uh + + + align:start position:0% +impact here I I was managing a an NSF uh +project called partners for Innovation + + align:start position:0% +project called partners for Innovation + + + align:start position:0% +project called partners for Innovation +which involved two industry leaders uh + + align:start position:0% +which involved two industry leaders uh + + + align:start position:0% +which involved two industry leaders uh +ersad and on GST over in + + align:start position:0% +ersad and on GST over in + + + align:start position:0% +ersad and on GST over in +Maryland and looking at developing an + + align:start position:0% +Maryland and looking at developing an + + + align:start position:0% +Maryland and looking at developing an +Enterprise as well as a curriculum for + + align:start position:0% +Enterprise as well as a curriculum for + + + align:start position:0% +Enterprise as well as a curriculum for +geospatial Technologies and so that's + + align:start position:0% +geospatial Technologies and so that's + + + align:start position:0% +geospatial Technologies and so that's +what I was doing for the past two years + + align:start position:0% +what I was doing for the past two years + + + align:start position:0% +what I was doing for the past two years +was developing a + + align:start position:0% +was developing a + + + align:start position:0% +was developing a +geospatial uh curriculum based on + + align:start position:0% +geospatial uh curriculum based on + + + align:start position:0% +geospatial uh curriculum based on +tradition and culture it was very + + align:start position:0% +tradition and culture it was very + + + align:start position:0% +tradition and culture it was very +interesting because really you know our + + align:start position:0% +interesting because really you know our + + + align:start position:0% +interesting because really you know our +approach + + align:start position:0% +approach + + + align:start position:0% +approach +to technology through this new + + align:start position:0% +to technology through this new + + + align:start position:0% +to technology through this new +innovation was what I call growing + + align:start position:0% +innovation was what I call growing + + + align:start position:0% +innovation was what I call growing +technology from the bottom up rather the + + align:start position:0% +technology from the bottom up rather the + + + align:start position:0% +technology from the bottom up rather the +top down where the land base and the + + align:start position:0% +top down where the land base and the + + + align:start position:0% +top down where the land base and the +culture was really the substance for + + align:start position:0% +culture was really the substance for + + + align:start position:0% +culture was really the substance for +developing introductions to GIS + + align:start position:0% +developing introductions to GIS + + + align:start position:0% +developing introductions to GIS +GPS and looking at this through a + + align:start position:0% +GPS and looking at this through a + + + align:start position:0% +GPS and looking at this through a +flowering tree which all the branches + + align:start position:0% +flowering tree which all the branches + + + align:start position:0% +flowering tree which all the branches +were all the different applications and + + align:start position:0% +were all the different applications and + + + align:start position:0% +were all the different applications and +the systems approached to it and all the + + align:start position:0% +the systems approached to it and all the + + + align:start position:0% +the systems approached to it and all the +programming so you know it it followed + + align:start position:0% +programming so you know it it followed + + + align:start position:0% +programming so you know it it followed +sort of this natural trunk of the tree + + align:start position:0% +sort of this natural trunk of the tree + + + align:start position:0% +sort of this natural trunk of the tree +to flower out like + + align:start position:0% +to flower out like + + + align:start position:0% +to flower out like +that so that was our approach to Growing + + align:start position:0% +that so that was our approach to Growing + + + align:start position:0% +that so that was our approach to Growing +it from the bottom up based on the + + align:start position:0% +it from the bottom up based on the + + + align:start position:0% +it from the bottom up based on the +Lakota Paradigm philosophy so the the + + align:start position:0% +Lakota Paradigm philosophy so the the + + + align:start position:0% +Lakota Paradigm philosophy so the the +the National Science Foundation has + + align:start position:0% +the National Science Foundation has + + + align:start position:0% +the National Science Foundation has +really been you know supporter of us for + + align:start position:0% +really been you know supporter of us for + + + align:start position:0% +really been you know supporter of us for +and because they've been supporting + + align:start position:0% +and because they've been supporting + + + align:start position:0% +and because they've been supporting +curriculum for in since + + align:start position:0% +curriculum for in since + + + align:start position:0% +curriculum for in since +the '90s about the developing GIS + + align:start position:0% +the '90s about the developing GIS + + + align:start position:0% +the '90s about the developing GIS +curriculum but they funded one more a + + align:start position:0% +curriculum but they funded one more a + + + align:start position:0% +curriculum but they funded one more a +cultural approach so I was really really + + align:start position:0% +cultural approach so I was really really + + + align:start position:0% +cultural approach so I was really really +glad that they were uh inspired by uh + + align:start position:0% +glad that they were uh inspired by uh + + + align:start position:0% +glad that they were uh inspired by uh +our proposal but yeah we have just you + + align:start position:0% +our proposal but yeah we have just you + + + align:start position:0% +our proposal but yeah we have just you +know developed significant relationships + + align:start position:0% +know developed significant relationships + + + align:start position:0% +know developed significant relationships +with other entities + + align:start position:0% +with other entities + + + align:start position:0% +with other entities +here but I want to + + align:start position:0% +here but I want to + + + align:start position:0% +here but I want to +uh and I showed this slide at in in + + align:start position:0% +uh and I showed this slide at in in + + + align:start position:0% +uh and I showed this slide at in in +Reston because it you know maybe other + + align:start position:0% +Reston because it you know maybe other + + + align:start position:0% +Reston because it you know maybe other +people in USGS didn't realize what what + + align:start position:0% +people in USGS didn't realize what what + + + align:start position:0% +people in USGS didn't realize what what +USGS was really doing with seski + + align:start position:0% +USGS was really doing with seski + + + align:start position:0% +USGS was really doing with seski +University but I heard buzzwords at + + align:start position:0% +University but I heard buzzwords at + + + align:start position:0% +University but I heard buzzwords at +science impact talking about better + + align:start position:0% +science impact talking about better + + + align:start position:0% +science impact talking about better +business + + align:start position:0% +business + + + align:start position:0% +business +practices well we entered into what we + + align:start position:0% +practices well we entered into what we + + + align:start position:0% +practices well we entered into what we +call a better a new way of doing + + align:start position:0% +call a better a new way of doing + + + align:start position:0% +call a better a new way of doing +business well I'll say it's new because + + align:start position:0% +business well I'll say it's new because + + + align:start position:0% +business well I'll say it's new because +it's all centered around + + align:start position:0% +it's all centered around + + + align:start position:0% +it's all centered around +Wakota and when we had a formal signing + + align:start position:0% +Wakota and when we had a formal signing + + + align:start position:0% +Wakota and when we had a formal signing +of ouru with the USGS we actually + + align:start position:0% +of ouru with the USGS we actually + + + align:start position:0% +of ouru with the USGS we actually +performed what we call a wot ceremony + + align:start position:0% +performed what we call a wot ceremony + + + align:start position:0% +performed what we call a wot ceremony +we invoked the higher powers and + + align:start position:0% +we invoked the higher powers and + + + align:start position:0% +we invoked the higher powers and +actually had a religious you know + + align:start position:0% +actually had a religious you know + + + align:start position:0% +actually had a religious you know +spiritual + + align:start position:0% +spiritual + + + align:start position:0% +spiritual +ceremony coinciding with the signing of + + align:start position:0% +ceremony coinciding with the signing of + + + align:start position:0% +ceremony coinciding with the signing of +this mou with the USGS and that really + + align:start position:0% +this mou with the USGS and that really + + + align:start position:0% +this mou with the USGS and that really +validated our own processes and it says + + align:start position:0% +validated our own processes and it says + + + align:start position:0% +validated our own processes and it says +to us as our University while + + align:start position:0% +to us as our University while + + + align:start position:0% +to us as our University while +we have finally found a mechanism to + + align:start position:0% +we have finally found a mechanism to + + + align:start position:0% +we have finally found a mechanism to +really utilize our culture and our + + align:start position:0% +really utilize our culture and our + + + align:start position:0% +really utilize our culture and our +spirituality and our new way of what we + + align:start position:0% +spirituality and our new way of what we + + + align:start position:0% +spirituality and our new way of what we +call better business + + align:start position:0% +call better business + + + align:start position:0% +call better business +practices so this really helps us uphold + + align:start position:0% +practices so this really helps us uphold + + + align:start position:0% +practices so this really helps us uphold +our end of the bargain regarding our our + + align:start position:0% +our end of the bargain regarding our our + + + align:start position:0% +our end of the bargain regarding our our +or mou at the + + align:start position:0% +or mou at the + + + align:start position:0% +or mou at the +USGS and I think that sort of impacted + + align:start position:0% +USGS and I think that sort of impacted + + + align:start position:0% +USGS and I think that sort of impacted +uh chip Groen himself when he came out + + align:start position:0% +uh chip Groen himself when he came out + + + align:start position:0% +uh chip Groen himself when he came out +with all the different uh + + align:start position:0% +with all the different uh + + + align:start position:0% +with all the different uh +leaders you know from the USGS all the + + align:start position:0% +leaders you know from the USGS all the + + + align:start position:0% +leaders you know from the USGS all the +different regional directors came there + + align:start position:0% +different regional directors came there + + + align:start position:0% +different regional directors came there +as + + align:start position:0% +as + + + align:start position:0% +as +well so I think we we did uh get into + + align:start position:0% +well so I think we we did uh get into + + + align:start position:0% +well so I think we we did uh get into +science impact in a way that you know + + align:start position:0% +science impact in a way that you know + + + align:start position:0% +science impact in a way that you know +kind of showed us that and showed them + + align:start position:0% +kind of showed us that and showed them + + + align:start position:0% +kind of showed us that and showed them +that we have a a mechanism doingit + + align:start position:0% +that we have a a mechanism doingit + + + align:start position:0% +that we have a a mechanism doingit +better + + align:start position:0% +better + + + align:start position:0% +better +business so that that really said + + align:start position:0% +business so that that really said + + + align:start position:0% +business so that that really said +something to the Community too that was + + align:start position:0% +something to the Community too that was + + + align:start position:0% +something to the Community too that was +there to see this ceremony to see that + + align:start position:0% +there to see this ceremony to see that + + + align:start position:0% +there to see this ceremony to see that +our traditions and culture are all going + + align:start position:0% +our traditions and culture are all going + + + align:start position:0% +our traditions and culture are all going +to be involved in this whole idea of of + + align:start position:0% +to be involved in this whole idea of of + + + align:start position:0% +to be involved in this whole idea of of +Wakota and the treaty with the United + + align:start position:0% +Wakota and the treaty with the United + + + align:start position:0% +Wakota and the treaty with the United +States Geological Survey our mou is up + + align:start position:0% +States Geological Survey our mou is up + + + align:start position:0% +States Geological Survey our mou is up +again we're we're looking at the next + + align:start position:0% +again we're we're looking at the next + + + align:start position:0% +again we're we're looking at the next +five years uh and I think you know + + align:start position:0% +five years uh and I think you know + + + align:start position:0% +five years uh and I think you know +science impact is going to be part of + + align:start position:0% +science impact is going to be part of + + + align:start position:0% +science impact is going to be part of +our our our mou and and relationship + + align:start position:0% +our our our mou and and relationship + + + align:start position:0% +our our our mou and and relationship +with the USGS + + align:start position:0% +with the USGS + + + align:start position:0% +with the USGS +so but that's what it is relationship + + align:start position:0% +so but that's what it is relationship + + + align:start position:0% +so but that's what it is relationship +building and I think that's the key word + + align:start position:0% +building and I think that's the key word + + + align:start position:0% +building and I think that's the key word +to to all these things about conflict + + align:start position:0% +to to all these things about conflict + + + align:start position:0% +to to all these things about conflict +coming to some sense of solution it's + + align:start position:0% +coming to some sense of solution it's + + + align:start position:0% +coming to some sense of solution it's +all regarding knowing each + + align:start position:0% +all regarding knowing each + + + align:start position:0% +all regarding knowing each +other I had a kind of an elder friend + + align:start position:0% +other I had a kind of an elder friend + + + align:start position:0% +other I had a kind of an elder friend +describe to + + align:start position:0% +describe to + + + align:start position:0% +describe to +me um the idea that we all sit down at + + align:start position:0% +me um the idea that we all sit down at + + + align:start position:0% +me um the idea that we all sit down at +the + + align:start position:0% +the + + + align:start position:0% +the +table and he said just imagine that + + align:start position:0% +table and he said just imagine that + + + align:start position:0% +table and he said just imagine that +there's this big colored beach ball in + + align:start position:0% +there's this big colored beach ball in + + + align:start position:0% +there's this big colored beach ball in +front of you we're all sitting around it + + align:start position:0% +front of you we're all sitting around it + + + align:start position:0% +front of you we're all sitting around it +each one will argue and tell you well I + + align:start position:0% +each one will argue and tell you well I + + + align:start position:0% +each one will argue and tell you well I +see see a red stripe and this is what it + + align:start position:0% +see see a red stripe and this is what it + + + align:start position:0% +see see a red stripe and this is what it +is it's a red stripe and this guy will + + align:start position:0% +is it's a red stripe and this guy will + + + align:start position:0% +is it's a red stripe and this guy will +they all go around and tell you what + + align:start position:0% +they all go around and tell you what + + + align:start position:0% +they all go around and tell you what +color they see and Advocate that that's + + align:start position:0% +color they see and Advocate that that's + + + align:start position:0% +color they see and Advocate that that's +what this is it's it's + + align:start position:0% +what this is it's it's + + + align:start position:0% +what this is it's it's +green but collectively we all hold + + align:start position:0% +green but collectively we all hold + + + align:start position:0% +green but collectively we all hold +together what that ball really is it's + + align:start position:0% +together what that ball really is it's + + + align:start position:0% +together what that ball really is it's +multi-striped it's all that's what it is + + align:start position:0% +multi-striped it's all that's what it is + + + align:start position:0% +multi-striped it's all that's what it is +but we're so opinionated to see what's + + align:start position:0% +but we're so opinionated to see what's + + + align:start position:0% +but we're so opinionated to see what's +in front of us and always thought that + + align:start position:0% +in front of us and always thought that + + + align:start position:0% +in front of us and always thought that +you know so so the things that I I've + + align:start position:0% +you know so so the things that I I've + + + align:start position:0% +you know so so the things that I I've +heard from the eldership in our + + align:start position:0% +heard from the eldership in our + + + align:start position:0% +heard from the eldership in our +reservation with how they how they talk + + align:start position:0% +reservation with how they how they talk + + + align:start position:0% +reservation with how they how they talk +and relate things I know there are + + align:start position:0% +and relate things I know there are + + + align:start position:0% +and relate things I know there are +solutions so that this is why this this + + align:start position:0% +solutions so that this is why this this + + + align:start position:0% +solutions so that this is why this this +new way of doing business in invites + + align:start position:0% +new way of doing business in invites + + + align:start position:0% +new way of doing business in invites +that whole level of expertise to be part + + align:start position:0% +that whole level of expertise to be part + + + align:start position:0% +that whole level of expertise to be part +of this process people that have common + + align:start position:0% +of this process people that have common + + + align:start position:0% +of this process people that have common +sense to me that's what I was I was + + align:start position:0% +sense to me that's what I was I was + + + align:start position:0% +sense to me that's what I was I was +asked this morning in class what is + + align:start position:0% +asked this morning in class what is + + + align:start position:0% +asked this morning in class what is +traditional knowledge and so I was given + + align:start position:0% +traditional knowledge and so I was given + + + align:start position:0% +traditional knowledge and so I was given +examples but really it is it's just + + align:start position:0% +examples but really it is it's just + + + align:start position:0% +examples but really it is it's just +common sense sometimes based on + + align:start position:0% +common sense sometimes based on + + + align:start position:0% +common sense sometimes based on +experiential knowledge you know that + + align:start position:0% +experiential knowledge you know that + + + align:start position:0% +experiential knowledge you know that +somehow rolls on into being + + align:start position:0% +somehow rolls on into being + + + align:start position:0% +somehow rolls on into being +wisdom + + align:start position:0% +wisdom + + + align:start position:0% +wisdom +well our our Science + + align:start position:0% +well our our Science + + + align:start position:0% +well our our Science +Center is sort of like this blending + + align:start position:0% +Center is sort of like this blending + + + align:start position:0% +Center is sort of like this blending +looking at new + + align:start position:0% +looking at new + + + align:start position:0% +looking at new +tools and the traditional + + align:start position:0% +tools and the traditional + + + align:start position:0% +tools and the traditional +knowledge always present this graphic to + + align:start position:0% +knowledge always present this graphic to + + + align:start position:0% +knowledge always present this graphic to +some of the students at the college + + align:start position:0% +some of the students at the college + + + align:start position:0% +some of the students at the college +having them look at their ancestors and + + align:start position:0% +having them look at their ancestors and + + + align:start position:0% +having them look at their ancestors and +their attributes because our attributes + + align:start position:0% +their attributes because our attributes + + + align:start position:0% +their attributes because our attributes +are + + align:start position:0% +are + + + align:start position:0% +are +adaptability we look at the natural + + align:start position:0% +adaptability we look at the natural + + + align:start position:0% +adaptability we look at the natural +world and how we have to adapt to it so + + align:start position:0% +world and how we have to adapt to it so + + + align:start position:0% +world and how we have to adapt to it so +we don't look at ourselves as as sort of + + align:start position:0% +we don't look at ourselves as as sort of + + + align:start position:0% +we don't look at ourselves as as sort of +well let's say climate change + + align:start position:0% +well let's say climate change + + + align:start position:0% +well let's say climate change +we have to adapt to climate and all that + + align:start position:0% +we have to adapt to climate and all that + + + align:start position:0% +we have to adapt to climate and all that +all the time so we find ourselves + + align:start position:0% +all the time so we find ourselves + + + align:start position:0% +all the time so we find ourselves +involved in really looking at ourselves + + align:start position:0% +involved in really looking at ourselves + + + align:start position:0% +involved in really looking at ourselves +in our adaptive strategies and these are + + align:start position:0% +in our adaptive strategies and these are + + + align:start position:0% +in our adaptive strategies and these are +exemplified + + align:start position:0% +exemplified + + + align:start position:0% +exemplified +by that that that man is is riding a + + align:start position:0% +by that that that man is is riding a + + + align:start position:0% +by that that that man is is riding a +horse and of course we all know + + align:start position:0% +horse and of course we all know + + + align:start position:0% +horse and of course we all know +historically the Spanish brought over + + align:start position:0% +historically the Spanish brought over + + + align:start position:0% +historically the Spanish brought over +the horses but somehow it's been written + + align:start position:0% +the horses but somehow it's been written + + + align:start position:0% +the horses but somehow it's been written +that the Plains Indian became the light + + align:start position:0% +that the Plains Indian became the light + + + align:start position:0% +that the Plains Indian became the light +the the best light Cavalry in the whole + + align:start position:0% +the the best light Cavalry in the whole + + + align:start position:0% +the the best light Cavalry in the whole +world because I think they they + + align:start position:0% +world because I think they they + + + align:start position:0% +world because I think they they +recognized the power of that animal and + + align:start position:0% +recognized the power of that animal and + + + align:start position:0% +recognized the power of that animal and +they developed a relationship with it + + align:start position:0% +they developed a relationship with it + + + align:start position:0% +they developed a relationship with it +they didn't think of him as a beast of + + align:start position:0% +they didn't think of him as a beast of + + + align:start position:0% +they didn't think of him as a beast of +burden they actually honor him they + + align:start position:0% +burden they actually honor him they + + + align:start position:0% +burden they actually honor him they +venerated him they gave him names they + + align:start position:0% +venerated him they gave him names they + + + align:start position:0% +venerated him they gave him names they +decorated him with feathers give him + + align:start position:0% +decorated him with feathers give him + + + align:start position:0% +decorated him with feathers give him +more honors as well and so they they + + align:start position:0% +more honors as well and so they they + + + align:start position:0% +more honors as well and so they they +brought him in as a + + align:start position:0% +brought him in as a + + + align:start position:0% +brought him in as a +relative so that's the way we have to + + align:start position:0% +relative so that's the way we have to + + + align:start position:0% +relative so that's the way we have to +look at technology is to to look at it + + align:start position:0% +look at technology is to to look at it + + + align:start position:0% +look at technology is to to look at it +for what it can bring to us and if we + + align:start position:0% +for what it can bring to us and if we + + + align:start position:0% +for what it can bring to us and if we +don't like it we don't we won't use it + + align:start position:0% +don't like it we don't we won't use it + + + align:start position:0% +don't like it we don't we won't use it +but if we do we need to embrace it into + + align:start position:0% +but if we do we need to embrace it into + + + align:start position:0% +but if we do we need to embrace it into +ourselves culturally so that's that's + + align:start position:0% +ourselves culturally so that's that's + + + align:start position:0% +ourselves culturally so that's that's +how we embrace the horse and the horse + + align:start position:0% +how we embrace the horse and the horse + + + align:start position:0% +how we embrace the horse and the horse +has caused us to gather + + align:start position:0% +has caused us to gather + + + align:start position:0% +has caused us to gather +more to travel + + align:start position:0% +more to travel + + + align:start position:0% +more to travel +further and our Arts really flourished + + align:start position:0% +further and our Arts really flourished + + + align:start position:0% +further and our Arts really flourished +we had more time to decorate + + align:start position:0% +we had more time to decorate + + + align:start position:0% +we had more time to decorate +our our utilitarian objects everything + + align:start position:0% +our our utilitarian objects everything + + + align:start position:0% +our our utilitarian objects everything +flourished with that with that + + align:start position:0% +flourished with that with that + + + align:start position:0% +flourished with that with that +relationship with that animal and then + + align:start position:0% +relationship with that animal and then + + + align:start position:0% +relationship with that animal and then +that gentleman is holding a rifle that + + align:start position:0% +that gentleman is holding a rifle that + + + align:start position:0% +that gentleman is holding a rifle that +came to us in a in a way that we didn't + + align:start position:0% +came to us in a in a way that we didn't + + + align:start position:0% +came to us in a in a way that we didn't +understand it was shown to us as a + + align:start position:0% +understand it was shown to us as a + + + align:start position:0% +understand it was shown to us as a +weapon that killed us but also when we + + align:start position:0% +weapon that killed us but also when we + + + align:start position:0% +weapon that killed us but also when we +were able to secure it we became deadly + + align:start position:0% +were able to secure it we became deadly + + + align:start position:0% +were able to secure it we became deadly +within ourselves because although we + + align:start position:0% +within ourselves because although we + + + align:start position:0% +within ourselves because although we +didn't manufacture the + + align:start position:0% +didn't manufacture the + + + align:start position:0% +didn't manufacture the +gun we didn't manufacture the weapon I + + align:start position:0% +gun we didn't manufacture the weapon I + + + align:start position:0% +gun we didn't manufacture the weapon I +mean the bullets somehow we became + + align:start position:0% +mean the bullets somehow we became + + + align:start position:0% +mean the bullets somehow we became +enterprisers and were able to use that + + align:start position:0% +enterprisers and were able to use that + + + align:start position:0% +enterprisers and were able to use that +to our + + align:start position:0% +to our + + + align:start position:0% +to our +advantage so those are the things that + + align:start position:0% +advantage so those are the things that + + + align:start position:0% +advantage so those are the things that +that we have to look at as how we adapt + + align:start position:0% +that we have to look at as how we adapt + + + align:start position:0% +that we have to look at as how we adapt +things bring it into our culture make it + + align:start position:0% +things bring it into our culture make it + + + align:start position:0% +things bring it into our culture make it +it beneficial so that that's one thing + + align:start position:0% +it beneficial so that that's one thing + + + align:start position:0% +it beneficial so that that's one thing +I'm looking at is is is more of these + + align:start position:0% +I'm looking at is is is more of these + + + align:start position:0% +I'm looking at is is is more of these +kind of stories and examples for our + + align:start position:0% +kind of stories and examples for our + + + align:start position:0% +kind of stories and examples for our +youth to get expired inspired by their + + align:start position:0% +youth to get expired inspired by their + + + align:start position:0% +youth to get expired inspired by their +attributes or their their + + align:start position:0% +attributes or their their + + + align:start position:0% +attributes or their their +ancestors so this traditional knowledge + + align:start position:0% +ancestors so this traditional knowledge + + + align:start position:0% +ancestors so this traditional knowledge +thing is going to be a + + align:start position:0% + + + + align:start position:0% + +key to somewhat of a foundation that + + align:start position:0% +key to somewhat of a foundation that + + + align:start position:0% +key to somewhat of a foundation that +that we don't realize that we're + + align:start position:0% +that we don't realize that we're + + + align:start position:0% +that we don't realize that we're +standing on and we do need to know + + align:start position:0% +standing on and we do need to know + + + align:start position:0% +standing on and we do need to know +exactly what we're where we're standing + + align:start position:0% +exactly what we're where we're standing + + + align:start position:0% +exactly what we're where we're standing +all the + + align:start position:0% + + + + align:start position:0% + +time I'm going to sit down here and just + + align:start position:0% +time I'm going to sit down here and just + + + align:start position:0% +time I'm going to sit down here and just +kind of go through these CU these are + + align:start position:0% +kind of go through these CU these are + + + align:start position:0% +kind of go through these CU these are +pretty laborious but just if you can + + align:start position:0% +pretty laborious but just if you can + + + align:start position:0% +pretty laborious but just if you can +just read them and I guess maybe you can + + align:start position:0% +just read them and I guess maybe you can + + + align:start position:0% +just read them and I guess maybe you can +look look at it more carefully when it's + + align:start position:0% +look look at it more carefully when it's + + + align:start position:0% +look look at it more carefully when it's +online but these are some of the the the + + align:start position:0% +online but these are some of the the the + + + align:start position:0% +online but these are some of the the the +principles of our uh uh indigenous + + align:start position:0% +principles of our uh uh indigenous + + + align:start position:0% +principles of our uh uh indigenous +knowledge and knowledge Center to + + align:start position:0% +knowledge and knowledge Center to + + + align:start position:0% +knowledge and knowledge Center to +integrate the traditional knowledge into + + align:start position:0% +integrate the traditional knowledge into + + + align:start position:0% +integrate the traditional knowledge into +the scientific assessment of Land + + align:start position:0% +the scientific assessment of Land + + + align:start position:0% +the scientific assessment of Land +Management + + align:start position:0% +Management + + + align:start position:0% +Management +practices and that's one thing we want + + align:start position:0% +practices and that's one thing we want + + + align:start position:0% +practices and that's one thing we want +to really accomplish is the fact that U + + align:start position:0% +to really accomplish is the fact that U + + + align:start position:0% +to really accomplish is the fact that U +we're operating under regimes and + + align:start position:0% +we're operating under regimes and + + + align:start position:0% +we're operating under regimes and +policies that aren't ours in man + + align:start position:0% +policies that aren't ours in man + + + align:start position:0% +policies that aren't ours in man +managing our reservation lands and even + + align:start position:0% +managing our reservation lands and even + + + align:start position:0% +managing our reservation lands and even +wanted to and how can we be involved in + + align:start position:0% +wanted to and how can we be involved in + + + align:start position:0% +wanted to and how can we be involved in +in uh with our vested interest into our + + align:start position:0% +in uh with our vested interest into our + + + align:start position:0% +in uh with our vested interest into our +Aboriginal + + align:start position:0% +Aboriginal + + + align:start position:0% +Aboriginal +territories is to look at uh uh + + align:start position:0% +territories is to look at uh uh + + + align:start position:0% +territories is to look at uh uh +different Alternatives and how can our + + align:start position:0% +different Alternatives and how can our + + + align:start position:0% +different Alternatives and how can our +traditional knowledge be part of + + align:start position:0% +traditional knowledge be part of + + + align:start position:0% +traditional knowledge be part of +that and we want to really understand + + align:start position:0% +that and we want to really understand + + + align:start position:0% +that and we want to really understand +what happened to us so we want to make + + align:start position:0% +what happened to us so we want to make + + + align:start position:0% +what happened to us so we want to make +determinations how the changes in the + + align:start position:0% +determinations how the changes in the + + + align:start position:0% +determinations how the changes in the +ecos system have influenced the Lota way + + align:start position:0% +ecos system have influenced the Lota way + + + align:start position:0% +ecos system have influenced the Lota way +of + + align:start position:0% +of + + + align:start position:0% +of +life I was given an example uh today + + align:start position:0% +life I was given an example uh today + + + align:start position:0% +life I was given an example uh today +about a young Lota girl that I met at a + + align:start position:0% +about a young Lota girl that I met at a + + + align:start position:0% +about a young Lota girl that I met at a +grocery store she was a checkout Clerk + + align:start position:0% +grocery store she was a checkout Clerk + + + align:start position:0% +grocery store she was a checkout Clerk +and and I was buying a a squash because + + align:start position:0% +and and I was buying a a squash because + + + align:start position:0% +and and I was buying a a squash because +I was going to go home and + + align:start position:0% +I was going to go home and + + + align:start position:0% +I was going to go home and +cook and she asked me she said what is + + align:start position:0% +cook and she asked me she said what is + + + align:start position:0% +cook and she asked me she said what is +this is this a what is this is a + + align:start position:0% +this is this a what is this is a + + + align:start position:0% +this is this a what is this is a +vegetable or fruit I said oh my + + align:start position:0% +vegetable or fruit I said oh my + + + align:start position:0% +vegetable or fruit I said oh my +God I didn't realize it here's a young + + align:start position:0% +God I didn't realize it here's a young + + + align:start position:0% +God I didn't realize it here's a young +Indian lady that probably doesn't know + + align:start position:0% +Indian lady that probably doesn't know + + + align:start position:0% +Indian lady that probably doesn't know +her food sources and and those are the + + align:start position:0% +her food sources and and those are the + + + align:start position:0% +her food sources and and those are the +kind of things I want to we want to + + align:start position:0% +kind of things I want to we want to + + + align:start position:0% +kind of things I want to we want to +understand why is it that we have youth + + align:start position:0% +understand why is it that we have youth + + + align:start position:0% +understand why is it that we have youth +that right now that don't understand + + align:start position:0% +that right now that don't understand + + + align:start position:0% +that right now that don't understand +that things grow and come from the earth + + align:start position:0% +that things grow and come from the earth + + + align:start position:0% +that things grow and come from the earth +you know oh my God we about 10 minutes + + align:start position:0% +you know oh my God we about 10 minutes + + + align:start position:0% +you know oh my God we about 10 minutes +and if we're going to have any chance + + align:start position:0% +and if we're going to have any chance + + + align:start position:0% +and if we're going to have any chance +for people to ask questions I'd love to + + align:start position:0% +for people to ask questions I'd love to + + + align:start position:0% +for people to ask questions I'd love to +rescue those last few minutes if okay + + align:start position:0% +rescue those last few minutes if okay + + + align:start position:0% +rescue those last few minutes if okay +let's do that okay well like I said + + align:start position:0% +let's do that okay well like I said + + + align:start position:0% +let's do that okay well like I said +there's just a lot of uh things I have + + align:start position:0% +there's just a lot of uh things I have + + + align:start position:0% +there's just a lot of uh things I have +here but I want to get to this idea what + + align:start position:0% +here but I want to get to this idea what + + + align:start position:0% +here but I want to get to this idea what +we're already starting to look at as far + + align:start position:0% +we're already starting to look at as far + + + align:start position:0% +we're already starting to look at as far +as our our our science uh impact + + align:start position:0% +as our our our science uh impact + + + align:start position:0% +as our our our science uh impact +project so you can read all these I + + align:start position:0% +project so you can read all these I + + + align:start position:0% +project so you can read all these I +guess this is going to be online and + + align:start position:0% +guess this is going to be online and + + + align:start position:0% +guess this is going to be online and +this is kind of just you know reasons + + align:start position:0% +this is kind of just you know reasons + + + align:start position:0% +this is kind of just you know reasons +and more reasons and major points + + align:start position:0% +and more reasons and major points + + + align:start position:0% +and more reasons and major points +uh but I want to get to this + + align:start position:0% +uh but I want to get to this + + + align:start position:0% +uh but I want to get to this +uh I use this imagery because it really + + align:start position:0% +uh I use this imagery because it really + + + align:start position:0% +uh I use this imagery because it really +sort of uh says more of the greater + + align:start position:0% +sort of uh says more of the greater + + + align:start position:0% +sort of uh says more of the greater +pictures this is the Black Hills of + + align:start position:0% +pictures this is the Black Hills of + + + align:start position:0% +pictures this is the Black Hills of +South Dakota up here's the north + + align:start position:0% +South Dakota up here's the north + + + align:start position:0% +South Dakota up here's the north +end but all of a sudden a lot of people + + align:start position:0% +end but all of a sudden a lot of people + + + align:start position:0% +end but all of a sudden a lot of people +really connect to imagery like that + + align:start position:0% +really connect to imagery like that + + + align:start position:0% +really connect to imagery like that +because all of a sudden there's not all + + align:start position:0% +because all of a sudden there's not all + + + align:start position:0% +because all of a sudden there's not all +these State boundary lines and all those + + align:start position:0% +these State boundary lines and all those + + + align:start position:0% +these State boundary lines and all those +kind of things that really encumber us + + align:start position:0% +kind of things that really encumber us + + + align:start position:0% +kind of things that really encumber us +and sort of limit us to to to imagine + + align:start position:0% +and sort of limit us to to to imagine + + + align:start position:0% +and sort of limit us to to to imagine +what is + + align:start position:0% +what is + + + align:start position:0% +what is +possible so we see that and when I show + + align:start position:0% +possible so we see that and when I show + + + align:start position:0% +possible so we see that and when I show +this to the Lakota people and that's + + align:start position:0% +this to the Lakota people and that's + + + align:start position:0% +this to the Lakota people and that's +their sacred Black Hills they just like + + align:start position:0% +their sacred Black Hills they just like + + + align:start position:0% +their sacred Black Hills they just like +they really love it so technology has + + align:start position:0% +they really love it so technology has + + + align:start position:0% +they really love it so technology has +its place in Lota culture now seeing + + align:start position:0% +its place in Lota culture now seeing + + + align:start position:0% +its place in Lota culture now seeing +that we can see our our homeland and + + align:start position:0% +that we can see our our homeland and + + + align:start position:0% +that we can see our our homeland and +Mother Earth in this + + align:start position:0% + + + + align:start position:0% + +vein now this is what I wanted to show + + align:start position:0% +vein now this is what I wanted to show + + + align:start position:0% +vein now this is what I wanted to show +you this is really really it brought an + + align:start position:0% +you this is really really it brought an + + + align:start position:0% +you this is really really it brought an +awareness to me and and it was almost + + align:start position:0% +awareness to me and and it was almost + + + align:start position:0% +awareness to me and and it was almost +scary to Appo + + align:start position:0% +scary to Appo + + + align:start position:0% +scary to Appo +that back in 1890 there was a man named + + align:start position:0% +that back in 1890 there was a man named + + + align:start position:0% +that back in 1890 there was a man named +Amos hard bad hard bull he drew this map + + align:start position:0% +Amos hard bad hard bull he drew this map + + + align:start position:0% +Amos hard bad hard bull he drew this map +of the Black Hills of South Dakota and + + align:start position:0% +of the Black Hills of South Dakota and + + + align:start position:0% +of the Black Hills of South Dakota and +it's in one of his books the collective + + align:start position:0% +it's in one of his books the collective + + + align:start position:0% +it's in one of his books the collective +of all his Ledger drawings but how + + align:start position:0% +of all his Ledger drawings but how + + + align:start position:0% +of all his Ledger drawings but how +detailed it was for all the rivers and + + align:start position:0% +detailed it was for all the rivers and + + + align:start position:0% +detailed it was for all the rivers and +all the geographical Place places there + + align:start position:0% +all the geographical Place places there + + + align:start position:0% +all the geographical Place places there +that were + + align:start position:0% +that were + + + align:start position:0% +that were +significant and then here comes another + + align:start position:0% +significant and then here comes another + + + align:start position:0% +significant and then here comes another +native guy John Harrington the astronaut + + align:start position:0% +native guy John Harrington the astronaut + + + align:start position:0% +native guy John Harrington the astronaut +2002 we asked him to take a picture of + + align:start position:0% +2002 we asked him to take a picture of + + + align:start position:0% +2002 we asked him to take a picture of +the Black + + align:start position:0% +the Black + + + align:start position:0% +the Black +Hills so we had that + + align:start position:0% +Hills so we had that + + + align:start position:0% +Hills so we had that +image and when I put this image beside + + align:start position:0% +image and when I put this image beside + + + align:start position:0% +image and when I put this image beside +the other one I was amazed to see the + + align:start position:0% +the other one I was amazed to see the + + + align:start position:0% +the other one I was amazed to see the +scale here's a man that's never been in + + align:start position:0% +scale here's a man that's never been in + + + align:start position:0% +scale here's a man that's never been in +space but he was able to draw in detail + + align:start position:0% +space but he was able to draw in detail + + + align:start position:0% +space but he was able to draw in detail +the same and almost in scale this is + + align:start position:0% +the same and almost in scale this is + + + align:start position:0% +the same and almost in scale this is +what like 800 miles in space looking + + align:start position:0% +what like 800 miles in space looking + + + align:start position:0% +what like 800 miles in space looking +down and this man he had the same image + + align:start position:0% +down and this man he had the same image + + + align:start position:0% +down and this man he had the same image +he drew the red racetrack around there + + align:start position:0% +he drew the red racetrack around there + + + align:start position:0% +he drew the red racetrack around there +which if you really look closely you'll + + align:start position:0% +which if you really look closely you'll + + + align:start position:0% +which if you really look closely you'll +see this whole red red uh ring around + + align:start position:0% +see this whole red red uh ring around + + + align:start position:0% +see this whole red red uh ring around +there which is the soil that so when the + + align:start position:0% +there which is the soil that so when the + + + align:start position:0% +there which is the soil that so when the +Black Hills emerged like that there was + + align:start position:0% +Black Hills emerged like that there was + + + align:start position:0% +Black Hills emerged like that there was +all this red soil around it and we have + + align:start position:0% +all this red soil around it and we have + + + align:start position:0% +all this red soil around it and we have +a a local story about this racetrack + + align:start position:0% +a a local story about this racetrack + + + align:start position:0% +a a local story about this racetrack +here so to me that was very powerful + + align:start position:0% +here so to me that was very powerful + + + align:start position:0% +here so to me that was very powerful +about people that really walk the land + + align:start position:0% +about people that really walk the land + + + align:start position:0% +about people that really walk the land +that knew the land they live their data + + align:start position:0% +that knew the land they live their data + + + align:start position:0% +that knew the land they live their data +we're able to draw things like this but + + align:start position:0% +we're able to draw things like this but + + + align:start position:0% +we're able to draw things like this but +today we have ways of looking down on it + + align:start position:0% +today we have ways of looking down on it + + + align:start position:0% +today we have ways of looking down on it +but we don't have ways of walking that + + align:start position:0% +but we don't have ways of walking that + + + align:start position:0% +but we don't have ways of walking that +land to really understand that there so + + align:start position:0% +land to really understand that there so + + + align:start position:0% +land to really understand that there so +there's a disconnection here that I see + + align:start position:0% +there's a disconnection here that I see + + + align:start position:0% +there's a disconnection here that I see +that you know as we approach the future + + align:start position:0% +that you know as we approach the future + + + align:start position:0% +that you know as we approach the future +we have to look at these tools that are + + align:start position:0% +we have to look at these tools that are + + + align:start position:0% +we have to look at these tools that are +available to us but also get back to + + align:start position:0% +available to us but also get back to + + + align:start position:0% +available to us but also get back to +this place where we walk the land we + + align:start position:0% +this place where we walk the land we + + + align:start position:0% +this place where we walk the land we +understand it and we can feel it and see + + align:start position:0% +understand it and we can feel it and see + + + align:start position:0% +understand it and we can feel it and see +it so this man he knew that land in + + align:start position:0% +it so this man he knew that land in + + + align:start position:0% +it so this man he knew that land in +intimately and was able to draw it much + + align:start position:0% +intimately and was able to draw it much + + + align:start position:0% +intimately and was able to draw it much +at the same scale as what we see in an + + align:start position:0% +at the same scale as what we see in an + + + align:start position:0% +at the same scale as what we see in an +image from space to me that's very + + align:start position:0% +image from space to me that's very + + + align:start position:0% +image from space to me that's very +inspirational and here's a constellation + + align:start position:0% +inspirational and here's a constellation + + + align:start position:0% +inspirational and here's a constellation +in the uh the sky as we know it it's + + align:start position:0% +in the uh the sky as we know it it's + + + align:start position:0% +in the uh the sky as we know it it's +called The Cheska wak but all this + + align:start position:0% +called The Cheska wak but all this + + + align:start position:0% +called The Cheska wak but all this +constellation and the Stars point to + + align:start position:0% +constellation and the Stars point to + + + align:start position:0% +constellation and the Stars point to +geographical features in the Black Hills + + align:start position:0% +geographical features in the Black Hills + + + align:start position:0% +geographical features in the Black Hills +of South + + align:start position:0% +of South + + + align:start position:0% +of South +Dakota + + align:start position:0% +Dakota + + + align:start position:0% +Dakota +so that's something that we we really + + align:start position:0% +so that's something that we we really + + + align:start position:0% +so that's something that we we really +that are timed with the seasons and + + align:start position:0% +that are timed with the seasons and + + + align:start position:0% +that are timed with the seasons and +certain activities have to happen for us + + align:start position:0% +certain activities have to happen for us + + + align:start position:0% +certain activities have to happen for us +culturally and we go out and do + + align:start position:0% +culturally and we go out and do + + + align:start position:0% +culturally and we go out and do +pilgrimages with these sacred sites so + + align:start position:0% +pilgrimages with these sacred sites so + + + align:start position:0% +pilgrimages with these sacred sites so +there's our connection from the land to + + align:start position:0% +there's our connection from the land to + + + align:start position:0% +there's our connection from the land to +the Stars so that that image from space + + align:start position:0% +the Stars so that that image from space + + + align:start position:0% +the Stars so that that image from space +said something to our people about the + + align:start position:0% +said something to our people about the + + + align:start position:0% +said something to our people about the +stars and how we're connected to them + + align:start position:0% +stars and how we're connected to them + + + align:start position:0% +stars and how we're connected to them +and I think even science has talents + + align:start position:0% +and I think even science has talents + + + align:start position:0% +and I think even science has talents +that that we're all + + align:start position:0% +that that we're all + + + align:start position:0% +that that we're all +Stardust we lotas knew that + + align:start position:0% +Stardust we lotas knew that + + + align:start position:0% +Stardust we lotas knew that +already but anyway here's the last image + + align:start position:0% +already but anyway here's the last image + + + align:start position:0% +already but anyway here's the last image +I want to show you is that same map that + + align:start position:0% +I want to show you is that same map that + + + align:start position:0% +I want to show you is that same map that +identified these cultural features here + + align:start position:0% +identified these cultural features here + + + align:start position:0% +identified these cultural features here +and the names of them in our language + + align:start position:0% +and the names of them in our language + + + align:start position:0% +and the names of them in our language +the racetrack around here over here's + + align:start position:0% +the racetrack around here over here's + + + align:start position:0% +the racetrack around here over here's +Devil's + + align:start position:0% +Devil's + + + align:start position:0% +Devil's +Tower it's called the Bears Lodge the + + align:start position:0% +Tower it's called the Bears Lodge the + + + align:start position:0% +Tower it's called the Bears Lodge the +slim bees all these things like that but + + align:start position:0% +slim bees all these things like that but + + + align:start position:0% +slim bees all these things like that but +that's sort of the things that we're we + + align:start position:0% +that's sort of the things that we're we + + + align:start position:0% +that's sort of the things that we're we +wanted to bring out in our traditional + + align:start position:0% +wanted to bring out in our traditional + + + align:start position:0% +wanted to bring out in our traditional +knowledge about our region and how we're + + align:start position:0% +knowledge about our region and how we're + + + align:start position:0% +knowledge about our region and how we're +connected to the stars and can reference + + align:start position:0% +connected to the stars and can reference + + + align:start position:0% +connected to the stars and can reference +all those things so we have this + + align:start position:0% +all those things so we have this + + + align:start position:0% +all those things so we have this +integrated approach to looking at our + + align:start position:0% +integrated approach to looking at our + + + align:start position:0% +integrated approach to looking at our +region + + align:start position:0% +region + + + align:start position:0% +region +well that's kind of it uh any + + align:start position:0% +well that's kind of it uh any + + + align:start position:0% +well that's kind of it uh any +questions + + align:start position:0% +questions + + + align:start position:0% +questions +yes as an outside of with very little + + align:start position:0% +yes as an outside of with very little + + + align:start position:0% +yes as an outside of with very little +knowledge of what you've been describing + + align:start position:0% +knowledge of what you've been describing + + + align:start position:0% +knowledge of what you've been describing +what I read in the newspapers is the + + align:start position:0% +what I read in the newspapers is the + + + align:start position:0% +what I read in the newspapers is the +importance of economic + + align:start position:0% +importance of economic + + + align:start position:0% +importance of economic +change not technology not science but + + align:start position:0% +change not technology not science but + + + align:start position:0% +change not technology not science but +fistance uh and I I have the impression + + align:start position:0% +fistance uh and I I have the impression + + + align:start position:0% +fistance uh and I I have the impression +that has transformed many + + align:start position:0% +that has transformed many + + + align:start position:0% +that has transformed many +reservations uh particularly in terms of + + align:start position:0% +reservations uh particularly in terms of + + + align:start position:0% +reservations uh particularly in terms of +what they have to offer which is said + + align:start position:0% +what they have to offer which is said + + + align:start position:0% +what they have to offer which is said +just to + + align:start position:0% +just to + + + align:start position:0% +just to +gambling and the amount of money that + + align:start position:0% +gambling and the amount of money that + + + align:start position:0% +gambling and the amount of money that +that brings in must diffuse and somehow + + align:start position:0% +that brings in must diffuse and somehow + + + align:start position:0% +that brings in must diffuse and somehow +or other your very + + align:start position:0% +or other your very + + + align:start position:0% +or other your very +interesting presentation didn't refer at + + align:start position:0% +interesting presentation didn't refer at + + + align:start position:0% +interesting presentation didn't refer at +all to the economic just and that imp so + + align:start position:0% +all to the economic just and that imp so + + + align:start position:0% +all to the economic just and that imp so +I wonder if you could just say something + + align:start position:0% +I wonder if you could just say something + + + align:start position:0% +I wonder if you could just say something +okay well our our University probably is + + align:start position:0% +okay well our our University probably is + + + align:start position:0% +okay well our our University probably is +really of all the universities I know + + align:start position:0% +really of all the universities I know + + + align:start position:0% +really of all the universities I know +are very steeped in the + + align:start position:0% +are very steeped in the + + + align:start position:0% +are very steeped in the +culture which is this concept of Seven + + align:start position:0% +culture which is this concept of Seven + + + align:start position:0% +culture which is this concept of Seven +Generations it's a very long + + align:start position:0% +Generations it's a very long + + + align:start position:0% +Generations it's a very long +perspective and the foundations of that + + align:start position:0% +perspective and the foundations of that + + + align:start position:0% +perspective and the foundations of that +are in the culture yes we are charged + + align:start position:0% +are in the culture yes we are charged + + + align:start position:0% +are in the culture yes we are charged +with economic development we're looking + + align:start position:0% +with economic development we're looking + + + align:start position:0% +with economic development we're looking +at a land base and how can we develop + + align:start position:0% +at a land base and how can we develop + + + align:start position:0% +at a land base and how can we develop +the the the intellect that we have there + + align:start position:0% +the the the intellect that we have there + + + align:start position:0% +the the the intellect that we have there +to look at making our land more + + align:start position:0% +to look at making our land more + + + align:start position:0% +to look at making our land more +productive you know we're I think all + + align:start position:0% +productive you know we're I think all + + + align:start position:0% +productive you know we're I think all +these things that you're hearing are + + align:start position:0% +these things that you're hearing are + + + align:start position:0% +these things that you're hearing are +very shortterm in terms of you know the + + align:start position:0% +very shortterm in terms of you know the + + + align:start position:0% +very shortterm in terms of you know the +culture in itself we really focused at + + align:start position:0% +culture in itself we really focused at + + + align:start position:0% +culture in itself we really focused at +the culture and where we've been and + + align:start position:0% +the culture and where we've been and + + + align:start position:0% +the culture and where we've been and +where we're going you know so so the + + align:start position:0% +where we're going you know so so the + + + align:start position:0% +where we're going you know so so the +culture Foundation is something that + + align:start position:0% +culture Foundation is something that + + + align:start position:0% +culture Foundation is something that +we're always trying to + + align:start position:0% +we're always trying to + + + align:start position:0% +we're always trying to +administer all these other things like + + align:start position:0% +administer all these other things like + + + align:start position:0% +administer all these other things like +that I think you know are are are the + + align:start position:0% +that I think you know are are are the + + + align:start position:0% +that I think you know are are are the +opportunities for our + + align:start position:0% +opportunities for our + + + align:start position:0% +opportunities for our +students we don't really look at the + + align:start position:0% +students we don't really look at the + + + align:start position:0% +students we don't really look at the +gaming right now I think that's more + + align:start position:0% +gaming right now I think that's more + + + align:start position:0% +gaming right now I think that's more +like + + align:start position:0% +like + + + align:start position:0% +like +shortterm it's not so much + + align:start position:0% +shortterm it's not so much + + + align:start position:0% +shortterm it's not so much +longterm but we are looking at the + + align:start position:0% +longterm but we are looking at the + + + align:start position:0% +longterm but we are looking at the +alternatives for our land use we're + + align:start position:0% +alternatives for our land use we're + + + align:start position:0% +alternatives for our land use we're +we're not next to any kind of big urban + + align:start position:0% +we're not next to any kind of big urban + + + align:start position:0% +we're not next to any kind of big urban +area like you know a city where we where + + align:start position:0% +area like you know a city where we where + + + align:start position:0% +area like you know a city where we where +we could really Thrive with with with + + align:start position:0% +we could really Thrive with with with + + + align:start position:0% +we could really Thrive with with with +gaming our our uh our our wealth is our + + align:start position:0% +gaming our our uh our our wealth is our + + + align:start position:0% +gaming our our uh our our wealth is our +spirituality and our culture so we look + + align:start position:0% +spirituality and our culture so we look + + + align:start position:0% +spirituality and our culture so we look +more towards uh let's say the + + align:start position:0% +more towards uh let's say the + + + align:start position:0% +more towards uh let's say the +restoration of + + align:start position:0% +restoration of + + + align:start position:0% +restoration of +Buffalo the restoration of the prairie + + align:start position:0% +Buffalo the restoration of the prairie + + + align:start position:0% +Buffalo the restoration of the prairie +ecosystem things that really matter the + + align:start position:0% +ecosystem things that really matter the + + + align:start position:0% +ecosystem things that really matter the +things that that that I guess most + + align:start position:0% +things that that that I guess most + + + align:start position:0% +things that that that I guess most +people discount as far and they take for + + align:start position:0% +people discount as far and they take for + + + align:start position:0% +people discount as far and they take for +granted you + + align:start position:0% +granted you + + + align:start position:0% +granted you +know but we do know that the Buffalo are + + align:start position:0% +know but we do know that the Buffalo are + + + align:start position:0% +know but we do know that the Buffalo are +the heart and soul of us in our in in an + + align:start position:0% +the heart and soul of us in our in in an + + + align:start position:0% +the heart and soul of us in our in in an +emergence from the land only reason I + + align:start position:0% +emergence from the land only reason I + + + align:start position:0% +emergence from the land only reason I +carry this message is because I there + + align:start position:0% +carry this message is because I there + + + align:start position:0% +carry this message is because I there +there are other people + + align:start position:0% +there are other people + + + align:start position:0% +there are other people +that sort of inspired me to to to give + + align:start position:0% +that sort of inspired me to to to give + + + align:start position:0% +that sort of inspired me to to to give +me this reality about natural law and + + align:start position:0% +me this reality about natural law and + + + align:start position:0% +me this reality about natural law and +who we are and where we came + + align:start position:0% + + + + align:start position:0% + +from but there there there that is very + + align:start position:0% +from but there there there that is very + + + align:start position:0% +from but there there there that is very +serious question about economic + + align:start position:0% +serious question about economic + + + align:start position:0% +serious question about economic +sustainability you know and the only + + align:start position:0% +sustainability you know and the only + + + align:start position:0% +sustainability you know and the only +thing we have is Our Land and + + align:start position:0% + + + + align:start position:0% + +people um I had a question about the + + align:start position:0% +people um I had a question about the + + + align:start position:0% +people um I had a question about the +data collection and um kind of the if + + align:start position:0% +data collection and um kind of the if + + + align:start position:0% +data collection and um kind of the if +you could speak a little bit more about + + align:start position:0% +you could speak a little bit more about + + + align:start position:0% +you could speak a little bit more about +the process of + + align:start position:0% +the process of + + + align:start position:0% +the process of +um whether it's students that are + + align:start position:0% +um whether it's students that are + + + align:start position:0% +um whether it's students that are +involved in the data collection or the + + align:start position:0% +involved in the data collection or the + + + align:start position:0% +involved in the data collection or the +community in terms of determining what + + align:start position:0% +community in terms of determining what + + + align:start position:0% +community in terms of determining what +information would be useful and and if + + align:start position:0% +information would be useful and and if + + + align:start position:0% +information would be useful and and if +that would be played + + align:start position:0% +that would be played + + + align:start position:0% +that would be played +out you heard me mentioning growing the + + align:start position:0% +out you heard me mentioning growing the + + + align:start position:0% +out you heard me mentioning growing the +technology from the bottom up you know + + align:start position:0% +technology from the bottom up you know + + + align:start position:0% +technology from the bottom up you know +in fact we want to meet Community needs + + align:start position:0% +in fact we want to meet Community needs + + + align:start position:0% +in fact we want to meet Community needs +because the administrative government + + align:start position:0% +because the administrative government + + + align:start position:0% +because the administrative government +will not they have their own their self- + + align:start position:0% +will not they have their own their self- + + + align:start position:0% +will not they have their own their self- +serving it seems to be but they don't + + align:start position:0% +serving it seems to be but they don't + + + align:start position:0% +serving it seems to be but they don't +really meet the community needs so we're + + align:start position:0% +really meet the community needs so we're + + + align:start position:0% +really meet the community needs so we're +looking at + + align:start position:0% +looking at + + + align:start position:0% +looking at +empowering the communi through students + + align:start position:0% +empowering the communi through students + + + align:start position:0% +empowering the communi through students +and + + align:start position:0% +and + + + align:start position:0% +and +myself looking at the emerging + + align:start position:0% +myself looking at the emerging + + + align:start position:0% +myself looking at the emerging +technologies that are uh what + + align:start position:0% +technologies that are uh what + + + align:start position:0% +technologies that are uh what +state-ofthe-art what we call the mobile + + align:start position:0% +state-ofthe-art what we call the mobile + + + align:start position:0% +state-ofthe-art what we call the mobile +Workforce today people out with uh data + + align:start position:0% +Workforce today people out with uh data + + + align:start position:0% +Workforce today people out with uh data +collection uh devices being right there + + align:start position:0% +collection uh devices being right there + + + align:start position:0% +collection uh devices being right there +on the land because all these people you + + align:start position:0% +on the land because all these people you + + + align:start position:0% +on the land because all these people you +know they they live on the land they + + align:start position:0% +know they they live on the land they + + + align:start position:0% +know they they live on the land they +live out in the country remember me I + + align:start position:0% +live out in the country remember me I + + + align:start position:0% +live out in the country remember me I +mentioned no there there's no street + + align:start position:0% +mentioned no there there's no street + + + align:start position:0% +mentioned no there there's no street +addresses on the + + align:start position:0% +addresses on the + + + align:start position:0% +addresses on the +reservation there are little hamlets and + + align:start position:0% +reservation there are little hamlets and + + + align:start position:0% +reservation there are little hamlets and +towns and communities but there's there + + align:start position:0% +towns and communities but there's there + + + align:start position:0% +towns and communities but there's there +so there's so so many applications but + + align:start position:0% +so there's so so many applications but + + + align:start position:0% +so there's so so many applications but +just no one Department no one person can + + align:start position:0% +just no one Department no one person can + + + align:start position:0% +just no one Department no one person can +do it so we looking to to people that + + align:start position:0% +do it so we looking to to people that + + + align:start position:0% +do it so we looking to to people that +are actually uh living out there to to + + align:start position:0% +are actually uh living out there to to + + + align:start position:0% +are actually uh living out there to to +empower them with so we are having + + align:start position:0% +empower them with so we are having + + + align:start position:0% +empower them with so we are having +training classes with the these handheld + + align:start position:0% +training classes with the these handheld + + + align:start position:0% +training classes with the these handheld +GPS units and these uh I packs for drop- + + align:start position:0% +GPS units and these uh I packs for drop- + + + align:start position:0% +GPS units and these uh I packs for drop- +down Manus for you know collecting + + align:start position:0% +down Manus for you know collecting + + + align:start position:0% +down Manus for you know collecting +data Are there specific um pieces of + + align:start position:0% +data Are there specific um pieces of + + + align:start position:0% +data Are there specific um pieces of +information that the community has + + align:start position:0% +information that the community has + + + align:start position:0% +information that the community has +identified as useful in terms of being + + align:start position:0% +identified as useful in terms of being + + + align:start position:0% +identified as useful in terms of being +able to help the community make + + align:start position:0% +able to help the community make + + + align:start position:0% +able to help the community make +decisions about land use or uh one of + + align:start position:0% +decisions about land use or uh one of + + + align:start position:0% +decisions about land use or uh one of +them is housing it's it's a big + + align:start position:0% +them is housing it's it's a big + + + align:start position:0% +them is housing it's it's a big +application because there's not enough + + align:start position:0% +application because there's not enough + + + align:start position:0% +application because there's not enough +housing you know so and then that + + align:start position:0% +housing you know so and then that + + + align:start position:0% +housing you know so and then that +relates to public + + align:start position:0% +relates to public + + + align:start position:0% +relates to public +safety and health related issues and + + align:start position:0% +safety and health related issues and + + + align:start position:0% +safety and health related issues and +things like that so so data is really uh + + align:start position:0% +things like that so so data is really uh + + + align:start position:0% +things like that so so data is really uh +critical and so we have to really + + align:start position:0% +critical and so we have to really + + + align:start position:0% +critical and so we have to really +utilize what I call the human capital + + align:start position:0% +utilize what I call the human capital + + + align:start position:0% +utilize what I call the human capital +which is probably our youth because + + align:start position:0% +which is probably our youth because + + + align:start position:0% +which is probably our youth because +they're they're really growing there's a + + align:start position:0% +they're they're really growing there's a + + + align:start position:0% +they're they're really growing there's a +lot more youth than than anything so so + + align:start position:0% +lot more youth than than anything so so + + + align:start position:0% +lot more youth than than anything so so +yeah this is kind of a k through 12 kind + + align:start position:0% +yeah this is kind of a k through 12 kind + + + align:start position:0% +yeah this is kind of a k through 12 kind +of a thing too that we're involved in at + + align:start position:0% +of a thing too that we're involved in at + + + align:start position:0% +of a thing too that we're involved in at +the university is not just you know the + + align:start position:0% +the university is not just you know the + + + align:start position:0% +the university is not just you know the +uh the college student high school + + align:start position:0% +uh the college student high school + + + align:start position:0% +uh the college student high school +student we're + + align:start position:0% +student we're + + + align:start position:0% +student we're +also involved through the teachers + + align:start position:0% +also involved through the teachers + + + align:start position:0% +also involved through the teachers +because we are an education institution + + align:start position:0% +because we are an education institution + + + align:start position:0% +because we are an education institution +we're we working with inservice and and + + align:start position:0% +we're we working with inservice and and + + + align:start position:0% +we're we working with inservice and and +pre-service for teachers regarding uh + + align:start position:0% +pre-service for teachers regarding uh + + + align:start position:0% +pre-service for teachers regarding uh +the technology and what it's going to + + align:start position:0% +the technology and what it's going to + + + align:start position:0% +the technology and what it's going to +take to empower + + align:start position:0% + + + + align:start position:0% + +community so I think that that's sort of + + align:start position:0% +community so I think that that's sort of + + + align:start position:0% +community so I think that that's sort of +uh circumventing the paternalism that + + align:start position:0% +uh circumventing the paternalism that + + + align:start position:0% +uh circumventing the paternalism that +that we've been operating under so far + + align:start position:0% +that we've been operating under so far + + + align:start position:0% +that we've been operating under so far +you know with the federal government is + + align:start position:0% +you know with the federal government is + + + align:start position:0% +you know with the federal government is +to do be more be more proactive + + align:start position:0% +to do be more be more proactive + + + align:start position:0% +to do be more be more proactive +one one of the arguments about new + + align:start position:0% +one one of the arguments about new + + + align:start position:0% +one one of the arguments about new +technology is that it should allow for + + align:start position:0% +technology is that it should allow for + + + align:start position:0% +technology is that it should allow for +new networks to form and for people to + + align:start position:0% +new networks to form and for people to + + + align:start position:0% +new networks to form and for people to +be in working collaboratively in ways + + align:start position:0% +be in working collaboratively in ways + + + align:start position:0% +be in working collaboratively in ways +that were difficult when they were + + align:start position:0% +that were difficult when they were + + + align:start position:0% +that were difficult when they were +seriously divided by + + align:start position:0% +seriously divided by + + + align:start position:0% +seriously divided by +space um does the coming of new + + align:start position:0% +space um does the coming of new + + + align:start position:0% +space um does the coming of new +technology change the way decisions are + + align:start position:0% +technology change the way decisions are + + + align:start position:0% +technology change the way decisions are +being made in Council or in conjunction + + align:start position:0% +being made in Council or in conjunction + + + align:start position:0% +being made in Council or in conjunction +with other tribes as you think about the + + align:start position:0% +with other tribes as you think about the + + + align:start position:0% +with other tribes as you think about the +management of larger resources + + align:start position:0% +management of larger resources + + + align:start position:0% +management of larger resources +do you actually see any evidence of + + align:start position:0% +do you actually see any evidence of + + + align:start position:0% +do you actually see any evidence of +dialogue happening that wouldn't happen + + align:start position:0% +dialogue happening that wouldn't happen + + + align:start position:0% +dialogue happening that wouldn't happen +absent of technology or of decisions + + align:start position:0% +absent of technology or of decisions + + + align:start position:0% +absent of technology or of decisions +being made in a different + + align:start position:0% +being made in a different + + + align:start position:0% +being made in a different +way okay well you know we do have a CO + + align:start position:0% +way okay well you know we do have a CO + + + align:start position:0% +way okay well you know we do have a CO +Consortium an American IND higher + + align:start position:0% +Consortium an American IND higher + + + align:start position:0% +Consortium an American IND higher +education + + align:start position:0% +education + + + align:start position:0% +education +Consortium and with that uh I know we've + + align:start position:0% +Consortium and with that uh I know we've + + + align:start position:0% +Consortium and with that uh I know we've +taken some initiatives in their support + + align:start position:0% +taken some initiatives in their support + + + align:start position:0% +taken some initiatives in their support +to actually form our own tribal College + + align:start position:0% +to actually form our own tribal College + + + align:start position:0% +to actually form our own tribal College +geographic information technology + + align:start position:0% +geographic information technology + + + align:start position:0% +geographic information technology +Consortium called native view so we're + + align:start position:0% +Consortium called native view so we're + + + align:start position:0% +Consortium called native view so we're +starting to to find those kind of + + align:start position:0% +starting to to find those kind of + + + align:start position:0% +starting to to find those kind of +synergies of like-minded + + align:start position:0% +synergies of like-minded + + + align:start position:0% +synergies of like-minded +people and of course at the higher + + align:start position:0% +people and of course at the higher + + + align:start position:0% +people and of course at the higher +levels like tribal + + align:start position:0% +levels like tribal + + + align:start position:0% +levels like tribal +presidents tribal government presidents + + align:start position:0% +presidents tribal government presidents + + + align:start position:0% +presidents tribal government presidents +they have + + align:start position:0% +they have + + + align:start position:0% +they have +organizations and we've been able just + + align:start position:0% +organizations and we've been able just + + + align:start position:0% +organizations and we've been able just +in small + + align:start position:0% +in small + + + align:start position:0% +in small +instances get on their agenda and talk + + align:start position:0% +instances get on their agenda and talk + + + align:start position:0% +instances get on their agenda and talk +to them about the uh you know the the + + align:start position:0% +to them about the uh you know the the + + + align:start position:0% +to them about the uh you know the the +enabling owering + + align:start position:0% +enabling owering + + + align:start position:0% +enabling owering +Technologies but we're at that level + + align:start position:0% +Technologies but we're at that level + + + align:start position:0% +Technologies but we're at that level +where we have a a form of leadership + + align:start position:0% +where we have a a form of leadership + + + align:start position:0% +where we have a a form of leadership +that is very care ful of losing power + + align:start position:0% +that is very care ful of losing power + + + align:start position:0% +that is very care ful of losing power +you know so so we kind of contend with + + align:start position:0% +you know so so we kind of contend with + + + align:start position:0% +you know so so we kind of contend with +that the power + + align:start position:0% +that the power + + + align:start position:0% +that the power +Brokers and and and that's a reality you + + align:start position:0% +Brokers and and and that's a reality you + + + align:start position:0% +Brokers and and and that's a reality you +know that one of the things that I know + + align:start position:0% +know that one of the things that I know + + + align:start position:0% +know that one of the things that I know +Herman and I are hoping is that um + + align:start position:0% +Herman and I are hoping is that um + + + align:start position:0% +Herman and I are hoping is that um +students here are engaged in what we + + align:start position:0% +students here are engaged in what we + + + align:start position:0% +students here are engaged in what we +call practicums all the time in which + + align:start position:0% +call practicums all the time in which + + + align:start position:0% +call practicums all the time in which +they take a problem in the World At + + align:start position:0% +they take a problem in the World At + + + align:start position:0% +they take a problem in the World At +Large they make that problem the focus + + align:start position:0% +Large they make that problem the focus + + + align:start position:0% +Large they make that problem the focus +of the class and they're trying to + + align:start position:0% +of the class and they're trying to + + + align:start position:0% +of the class and they're trying to +provide service at the same time as + + align:start position:0% +provide service at the same time as + + + align:start position:0% +provide service at the same time as +they're trying to learn how to use + + align:start position:0% +they're trying to learn how to use + + + align:start position:0% +they're trying to learn how to use +certain tools and and analytic + + align:start position:0% +certain tools and and analytic + + + align:start position:0% +certain tools and and analytic +techniques and if there were an + + align:start position:0% +techniques and if there were an + + + align:start position:0% +techniques and if there were an +opportunity to link up with a group of + + align:start position:0% +opportunity to link up with a group of + + + align:start position:0% +opportunity to link up with a group of +students at your University and take an + + align:start position:0% +students at your University and take an + + + align:start position:0% +students at your University and take an +actual problem not just in the + + align:start position:0% +actual problem not just in the + + + align:start position:0% +actual problem not just in the +University but in the community at large + + align:start position:0% +University but in the community at large + + + align:start position:0% +University but in the community at large +it's conceivable we could do some kind + + align:start position:0% +it's conceivable we could do some kind + + + align:start position:0% +it's conceivable we could do some kind +of joint practicum where people would + + align:start position:0% +of joint practicum where people would + + + align:start position:0% +of joint practicum where people would +bring the Knowledge and Skills they have + + align:start position:0% +bring the Knowledge and Skills they have + + + align:start position:0% +bring the Knowledge and Skills they have +here travel out spend some time learn + + align:start position:0% +here travel out spend some time learn + + + align:start position:0% +here travel out spend some time learn +something about the place and then + + align:start position:0% +something about the place and then + + + align:start position:0% +something about the place and then +continue to work uh with the group of + + align:start position:0% +continue to work uh with the group of + + + align:start position:0% +continue to work uh with the group of +students or a client group of leaders or + + align:start position:0% +students or a client group of leaders or + + + align:start position:0% +students or a client group of leaders or +people working on a particular problem + + align:start position:0% +people working on a particular problem + + + align:start position:0% +people working on a particular problem +whether the management of a natural + + align:start position:0% +whether the management of a natural + + + align:start position:0% +whether the management of a natural +resource or Imagining the design or + + align:start position:0% +resource or Imagining the design or + + + align:start position:0% +resource or Imagining the design or +redesign of some new application of + + align:start position:0% +redesign of some new application of + + + align:start position:0% +redesign of some new application of +technology so one of the long-term goals + + align:start position:0% +technology so one of the long-term goals + + + align:start position:0% +technology so one of the long-term goals +we have within the larger USGS + + align:start position:0% +we have within the larger USGS + + + align:start position:0% +we have within the larger USGS +collaborative is to see if we can't make + + align:start position:0% +collaborative is to see if we can't make + + + align:start position:0% +collaborative is to see if we can't make +practical connections that allow courses + + align:start position:0% +practical connections that allow courses + + + align:start position:0% +practical connections that allow courses +to stream into these same relationships + + align:start position:0% +to stream into these same relationships + + + align:start position:0% +to stream into these same relationships +that we're trying to build well thank + + align:start position:0% +that we're trying to build well thank + + + align:start position:0% +that we're trying to build well thank +you Larry because I I've thought of that + + align:start position:0% +you Larry because I I've thought of that + + + align:start position:0% +you Larry because I I've thought of that +in regard to my the my development which + + align:start position:0% +in regard to my the my development which + + + align:start position:0% +in regard to my the my development which +was an applied Curriculum by actually + + align:start position:0% +was an applied Curriculum by actually + + + align:start position:0% +was an applied Curriculum by actually +going out and doing something meaningful + + align:start position:0% +going out and doing something meaningful + + + align:start position:0% +going out and doing something meaningful +you know and learning from it and + + align:start position:0% +you know and learning from it and + + + align:start position:0% +you know and learning from it and +actually providing a solution the + + align:start position:0% +actually providing a solution the + + + align:start position:0% +actually providing a solution the +students here could come and yeah tell + + align:start position:0% +students here could come and yeah tell + + + align:start position:0% +students here could come and yeah tell +something to students there about actual + + align:start position:0% +something to students there about actual + + + align:start position:0% +something to students there about actual +practicums that they've already worked + + align:start position:0% +practicums that they've already worked + + + align:start position:0% +practicums that they've already worked +on here and talk about some of the + + align:start position:0% +on here and talk about some of the + + + align:start position:0% +on here and talk about some of the +issues and problems of trying to be cast + + align:start position:0% +issues and problems of trying to be cast + + + align:start position:0% +issues and problems of trying to be cast +in this intermediary role between your + + align:start position:0% +in this intermediary role between your + + + align:start position:0% +in this intermediary role between your +University and a client group you're in + + align:start position:0% +University and a client group you're in + + + align:start position:0% +University and a client group you're in +a course but you're also trying to do + + align:start position:0% +a course but you're also trying to do + + + align:start position:0% +a course but you're also trying to do +something useful they might be able to + + align:start position:0% +something useful they might be able to + + + align:start position:0% +something useful they might be able to +make a connection to a group of your + + align:start position:0% +make a connection to a group of your + + + align:start position:0% +make a connection to a group of your +students students talk about their + + align:start position:0% +students students talk about their + + + align:start position:0% +students students talk about their +experience and that might get a group of + + align:start position:0% +experience and that might get a group of + + + align:start position:0% +experience and that might get a group of +your students interested in organizing a + + align:start position:0% +your students interested in organizing a + + + align:start position:0% +your students interested in organizing a +local practicum even if the students + + align:start position:0% +local practicum even if the students + + + align:start position:0% +local practicum even if the students +from here don't work specifically on + + align:start position:0% +from here don't work specifically on + + + align:start position:0% +from here don't work specifically on +that project but we have uh over January + + align:start position:0% +that project but we have uh over January + + + align:start position:0% +that project but we have uh over January +we have a intercession period where a + + align:start position:0% +we have a intercession period where a + + + align:start position:0% +we have a intercession period where a +group of students from here could travel + + align:start position:0% +group of students from here could travel + + + align:start position:0% +group of students from here could travel +describe practicums and maybe get some + + align:start position:0% +describe practicums and maybe get some + + + align:start position:0% +describe practicums and maybe get some +of your students to begin to think about + + align:start position:0% +of your students to begin to think about + + + align:start position:0% +of your students to begin to think about +doing something like that okay I've + + align:start position:0% +doing something like that okay I've + + + align:start position:0% +doing something like that okay I've +already been thinking about what we can + + align:start position:0% +already been thinking about what we can + + + align:start position:0% +already been thinking about what we can +do together and sort of talked with uh + + align:start position:0% +do together and sort of talked with uh + + + align:start position:0% +do together and sort of talked with uh +Herman about the possibility if you can + + align:start position:0% +Herman about the possibility if you can + + + align:start position:0% +Herman about the possibility if you can +clear your February schedule and come + + align:start position:0% +clear your February schedule and come + + + align:start position:0% +clear your February schedule and come +out and and and uh meet myself and + + align:start position:0% +out and and and uh meet myself and + + + align:start position:0% +out and and and uh meet myself and +colleagues and some students we have + + align:start position:0% +colleagues and some students we have + + + align:start position:0% +colleagues and some students we have +what we call Founders week I think You' + + align:start position:0% +what we call Founders week I think You' + + + align:start position:0% +what we call Founders week I think You' +probably gain to learn more about our + + align:start position:0% +probably gain to learn more about our + + + align:start position:0% +probably gain to learn more about our +College because we have like public + + align:start position:0% +College because we have like public + + + align:start position:0% +College because we have like public +forums there and even meeting some of + + align:start position:0% +forums there and even meeting some of + + + align:start position:0% +forums there and even meeting some of +our esteemed professors you know and and + + align:start position:0% +our esteemed professors you know and and + + + align:start position:0% +our esteemed professors you know and and +because I've always wanted the scientist + + align:start position:0% +because I've always wanted the scientist + + + align:start position:0% +because I've always wanted the scientist +to sit down with the Lakota studies + + align:start position:0% +to sit down with the Lakota studies + + + align:start position:0% +to sit down with the Lakota studies +professors because they have I I would + + align:start position:0% +professors because they have I I would + + + align:start position:0% +professors because they have I I would +call them very Leading Edge applications + + align:start position:0% +call them very Leading Edge applications + + + align:start position:0% +call them very Leading Edge applications +research + + align:start position:0% +research + + + align:start position:0% +research +projects but they they need somebody to + + align:start position:0% +projects but they they need somebody to + + + align:start position:0% +projects but they they need somebody to +to listen to them and and interpret that + + align:start position:0% +to listen to them and and interpret that + + + align:start position:0% +to listen to them and and interpret that +into a + + align:start position:0% +into a + + + align:start position:0% +into a +project that has a deliverable that also + + align:start position:0% +project that has a deliverable that also + + + align:start position:0% +project that has a deliverable that also +exemplifies the disciplines of how you + + align:start position:0% +exemplifies the disciplines of how you + + + align:start position:0% +exemplifies the disciplines of how you +go through it you know and I think You' + + align:start position:0% +go through it you know and I think You' + + + align:start position:0% +go through it you know and I think You' +find innovation in some of these things + + align:start position:0% +find innovation in some of these things + + + align:start position:0% +find innovation in some of these things +that we're talking about one of them is + + align:start position:0% +that we're talking about one of them is + + + align:start position:0% +that we're talking about one of them is +is we have many things regarding the + + align:start position:0% +is we have many things regarding the + + + align:start position:0% +is we have many things regarding the +authorities in our in our treaties that + + align:start position:0% +authorities in our in our treaties that + + + align:start position:0% +authorities in our in our treaties that +we have no way of actually getting a + + align:start position:0% +we have no way of actually getting a + + + align:start position:0% +we have no way of actually getting a +jump start in in articul ating and + + align:start position:0% +jump start in in articul ating and + + + align:start position:0% +jump start in in articul ating and +researching and one of them is like you + + align:start position:0% +researching and one of them is like you + + + align:start position:0% +researching and one of them is like you +know + + align:start position:0% +know + + + align:start position:0% +know +um underground water modeling something + + align:start position:0% +um underground water modeling something + + + align:start position:0% +um underground water modeling something +like that because that's one a concern + + align:start position:0% +like that because that's one a concern + + + align:start position:0% +like that because that's one a concern +but there there's so many applications + + align:start position:0% +but there there's so many applications + + + align:start position:0% +but there there's so many applications +that that we have that if you sat down + + align:start position:0% +that that we have that if you sat down + + + align:start position:0% +that that we have that if you sat down +and listen you'd find them to be + + align:start position:0% +and listen you'd find them to be + + + align:start position:0% +and listen you'd find them to be +incredible as as very Innovative + + align:start position:0% +incredible as as very Innovative + + + align:start position:0% +incredible as as very Innovative +applications to to approach and learn + + align:start position:0% +applications to to approach and learn + + + align:start position:0% +applications to to approach and learn +from you know some of these have never + + align:start position:0% +from you know some of these have never + + + align:start position:0% +from you know some of these have never +been + + align:start position:0% +been + + + align:start position:0% +been +attempted yeah there's the there's the + + align:start position:0% +attempted yeah there's the there's the + + + align:start position:0% +attempted yeah there's the there's the +the treaty negotiation land claim ones + + align:start position:0% +the treaty negotiation land claim ones + + + align:start position:0% +the treaty negotiation land claim ones +are very Innovative but beond on that + + align:start position:0% +are very Innovative but beond on that + + + align:start position:0% +are very Innovative but beond on that +there if you sat and listened to some of + + align:start position:0% +there if you sat and listened to some of + + + align:start position:0% +there if you sat and listened to some of +our elders oh my God I'd like to do that + + align:start position:0% +our elders oh my God I'd like to do that + + + align:start position:0% +our elders oh my God I'd like to do that +as a project you know but I'm only going + + align:start position:0% +as a project you know but I'm only going + + + align:start position:0% +as a project you know but I'm only going +to live to be not 100 I don't think but + + align:start position:0% +to live to be not 100 I don't think but + + + align:start position:0% +to live to be not 100 I don't think but +I'd like to see a lot a lot of those + + align:start position:0% +I'd like to see a lot a lot of those + + + align:start position:0% +I'd like to see a lot a lot of those +things ported over to to our students to + + align:start position:0% +things ported over to to our students to + + + align:start position:0% +things ported over to to our students to +earn their phds on you + + align:start position:0% +earn their phds on you + + + align:start position:0% +earn their phds on you +know um let me thank you again for from + + align:start position:0% +know um let me thank you again for from + + + align:start position:0% +know um let me thank you again for from +all of us for traveling here and + + align:start position:0% +all of us for traveling here and + + + align:start position:0% +all of us for traveling here and +beginning of process of conversation + + align:start position:0% +beginning of process of conversation + + + align:start position:0% +beginning of process of conversation +that we hope will lead to some + + align:start position:0% +that we hope will lead to some + + + align:start position:0% +that we hope will lead to some +collaborative work students here have + + align:start position:0% +collaborative work students here have + + + align:start position:0% +collaborative work students here have +2:00 classes that they're now L for so + + align:start position:0% +2:00 classes that they're now L for so + + + align:start position:0% +2:00 classes that they're now L for so +we're going + + align:start position:0% + + + + align:start position:0% + +to \ No newline at end of file diff --git a/7LyvAVjQUR8.txt b/7LyvAVjQUR8.txt new file mode 100644 index 0000000000000000000000000000000000000000..93127fb1f2c67444ae42d15fc134b2aad14096e8 --- /dev/null +++ b/7LyvAVjQUR8.txt @@ -0,0 +1,10115 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +okay guys welcome to the first filmed + + align:start position:0% +okay guys welcome to the first filmed + + + align:start position:0% +okay guys welcome to the first filmed +and hands-on installation of 2201 + + align:start position:0% +and hands-on installation of 2201 + + + align:start position:0% +and hands-on installation of 2201 +introduction to ionizing radiation mike + + align:start position:0% +introduction to ionizing radiation mike + + + align:start position:0% +introduction to ionizing radiation mike +short i'm the department's undergrad + + align:start position:0% +short i'm the department's undergrad + + + align:start position:0% +short i'm the department's undergrad +coordinator multi ER 2201 instructor but + + align:start position:0% +coordinator multi ER 2201 instructor but + + + align:start position:0% +coordinator multi ER 2201 instructor but +i also want to introduce you to Amelia + + align:start position:0% +i also want to introduce you to Amelia + + + align:start position:0% +i also want to introduce you to Amelia +Trainor in the back who's one of the + + align:start position:0% +Trainor in the back who's one of the + + + align:start position:0% +Trainor in the back who's one of the +three TAS for the course she took it + + align:start position:0% +three TAS for the course she took it + + + align:start position:0% +three TAS for the course she took it +last year everything's still very fresh + + align:start position:0% +last year everything's still very fresh + + + align:start position:0% +last year everything's still very fresh +in your head I bet so cool so she'll be + + align:start position:0% +in your head I bet so cool so she'll be + + + align:start position:0% +in your head I bet so cool so she'll be +she and Kayne Yau and Caitlin Fisher + + align:start position:0% +she and Kayne Yau and Caitlin Fisher + + + align:start position:0% +she and Kayne Yau and Caitlin Fisher +will be with us all throughout the term + + align:start position:0% +will be with us all throughout the term + + + align:start position:0% +will be with us all throughout the term +so if there's something that you don't + + align:start position:0% +so if there's something that you don't + + + align:start position:0% +so if there's something that you don't +like my explanation for you've got three + + align:start position:0% +like my explanation for you've got three + + + align:start position:0% +like my explanation for you've got three +people who just took the course and + + align:start position:0% +people who just took the course and + + + align:start position:0% +people who just took the course and +struggled through my own explanations + + align:start position:0% +struggled through my own explanations + + + align:start position:0% +struggled through my own explanations +and can say it in a different way so + + align:start position:0% +and can say it in a different way so + + + align:start position:0% +and can say it in a different way so +let's start off by taking your knowledge + + align:start position:0% +let's start off by taking your knowledge + + + align:start position:0% +let's start off by taking your knowledge +of physics from the roughly eighteen + + align:start position:0% +of physics from the roughly eighteen + + + align:start position:0% +of physics from the roughly eighteen +hundred's education of the Gir general + + align:start position:0% +hundred's education of the Gir general + + + align:start position:0% +hundred's education of the Gir general +Institute requirements up till 1932 when + + align:start position:0% +Institute requirements up till 1932 when + + + align:start position:0% +Institute requirements up till 1932 when +the neutron was discovered and I would + + align:start position:0% +the neutron was discovered and I would + + + align:start position:0% +the neutron was discovered and I would +argue that this particle is what makes + + align:start position:0% +argue that this particle is what makes + + + align:start position:0% +argue that this particle is what makes +us nuclear engineers it's the basis + + align:start position:0% +us nuclear engineers it's the basis + + + align:start position:0% +us nuclear engineers it's the basis +behind reactors it was what + + align:start position:0% +behind reactors it was what + + + align:start position:0% +behind reactors it was what +differentiates us from the high-energy + + align:start position:0% +differentiates us from the high-energy + + + align:start position:0% +differentiates us from the high-energy +physics folks and everything because we + + align:start position:0% +physics folks and everything because we + + + align:start position:0% +physics folks and everything because we +study these and use them quite a lot and + + align:start position:0% +study these and use them quite a lot and + + + align:start position:0% +study these and use them quite a lot and +so we want to retrace Chadwick steps in + + align:start position:0% +so we want to retrace Chadwick steps in + + + align:start position:0% +so we want to retrace Chadwick steps in +discovering the neutron and this is the + + align:start position:0% +discovering the neutron and this is the + + + align:start position:0% +discovering the neutron and this is the +only time you're ever going to see me + + align:start position:0% +only time you're ever going to see me + + + align:start position:0% +only time you're ever going to see me +have a bunch of words on a slide it's + + align:start position:0% +have a bunch of words on a slide it's + + + align:start position:0% +have a bunch of words on a slide it's +not a presentation technique I like but + + align:start position:0% +not a presentation technique I like but + + + align:start position:0% +not a presentation technique I like but +this paper is awesome in the clarity and + + align:start position:0% +this paper is awesome in the clarity and + + + align:start position:0% +this paper is awesome in the clarity and +expressiveness of saying I ran this + + align:start position:0% +expressiveness of saying I ran this + + + align:start position:0% +expressiveness of saying I ran this +experiment found something unknown I use + + align:start position:0% +experiment found something unknown I use + + + align:start position:0% +experiment found something unknown I use +basic conservation of energy and things + + align:start position:0% +basic conservation of energy and things + + + align:start position:0% +basic conservation of energy and things +you learned in 801 and 802 to prove that + + align:start position:0% +you learned in 801 and 802 to prove that + + + align:start position:0% +you learned in 801 and 802 to prove that +it has to be in Neutron that there + + align:start position:0% +it has to be in Neutron that there + + + align:start position:0% +it has to be in Neutron that there +Neutron must exist it's elegant and + + align:start position:0% +Neutron must exist it's elegant and + + + align:start position:0% +Neutron must exist it's elegant and +brilliant and I want to walk you guys + + align:start position:0% +brilliant and I want to walk you guys + + + align:start position:0% +brilliant and I want to walk you guys +through it then do you get a chance to + + align:start position:0% +through it then do you get a chance to + + + align:start position:0% +through it then do you get a chance to +read the Chadwick article yet okay I'll + + align:start position:0% +read the Chadwick article yet okay I'll + + + align:start position:0% +read the Chadwick article yet okay I'll +show you where that is because hopefully + + align:start position:0% +show you where that is because hopefully + + + align:start position:0% +show you where that is because hopefully +by now you're all aware that we have a + + align:start position:0% +by now you're all aware that we have a + + + align:start position:0% +by now you're all aware that we have a +learning module site it's where I'm + + align:start position:0% +learning module site it's where I'm + + + align:start position:0% +learning module site it's where I'm +going to post everything it's where + + align:start position:0% +going to post everything it's where + + + align:start position:0% +going to post everything it's where +you're going to submit everything for + + align:start position:0% +you're going to submit everything for + + + align:start position:0% +you're going to submit everything for +the class but I'll save till the end of + + align:start position:0% +the class but I'll save till the end of + + + align:start position:0% +the class but I'll save till the end of +this class to go through the actual + + align:start position:0% +this class to go through the actual + + + align:start position:0% +this class to go through the actual +syllabus because I want to get into the + + align:start position:0% +syllabus because I want to get into the + + + align:start position:0% +syllabus because I want to get into the +physics so let's bring your knowledge + + align:start position:0% +physics so let's bring your knowledge + + + align:start position:0% +physics so let's bring your knowledge +from classical mechanics and enm up till + + align:start position:0% +from classical mechanics and enm up till + + + align:start position:0% +from classical mechanics and enm up till +about 1895 when Wilhelm roentgen used + + align:start position:0% +about 1895 when Wilhelm roentgen used + + + align:start position:0% +about 1895 when Wilhelm roentgen used +x-rays and use them to well image + + align:start position:0% +x-rays and use them to well image + + + align:start position:0% +x-rays and use them to well image +something for the first time ever + + align:start position:0% +something for the first time ever + + + align:start position:0% +something for the first time ever +showing the contrast between bone and + + align:start position:0% +showing the contrast between bone and + + + align:start position:0% +showing the contrast between bone and +tissue is able to illuminate the bones + + align:start position:0% +tissue is able to illuminate the bones + + + align:start position:0% +tissue is able to illuminate the bones +in a hand and then about a year later + + align:start position:0% +in a hand and then about a year later + + + align:start position:0% +in a hand and then about a year later +the x-rays got a whole lot + + align:start position:0% +the x-rays got a whole lot + + + align:start position:0% +the x-rays got a whole lot +so by then it was known that there were + + align:start position:0% +so by then it was known that there were + + + align:start position:0% +so by then it was known that there were +high-energy photons that had + + align:start position:0% +high-energy photons that had + + + align:start position:0% +high-energy photons that had +differential contrast between different + + align:start position:0% +differential contrast between different + + + align:start position:0% +differential contrast between different +types of material your later after the + + align:start position:0% +types of material your later after the + + + align:start position:0% +types of material your later after the +nicer x-ray JJ Thompson conclusively + + align:start position:0% +nicer x-ray JJ Thompson conclusively + + + align:start position:0% +nicer x-ray JJ Thompson conclusively +proved that there is an electron by + + align:start position:0% +proved that there is an electron by + + + align:start position:0% +proved that there is an electron by +taking these cathode rays as they were + + align:start position:0% +taking these cathode rays as they were + + + align:start position:0% +taking these cathode rays as they were +called at one point and sending them + + align:start position:0% +called at one point and sending them + + + align:start position:0% +called at one point and sending them +through two charged plates and he was + + align:start position:0% +through two charged plates and he was + + + align:start position:0% +through two charged plates and he was +able to show a slight deflection so + + align:start position:0% +able to show a slight deflection so + + + align:start position:0% +able to show a slight deflection so +these cathode rays as they passed + + align:start position:0% +these cathode rays as they passed + + + align:start position:0% +these cathode rays as they passed +through an electric field change + + align:start position:0% +through an electric field change + + + align:start position:0% +through an electric field change +direction a little bit and from the + + align:start position:0% +direction a little bit and from the + + + align:start position:0% +direction a little bit and from the +change in direction you may not know the + + align:start position:0% +change in direction you may not know the + + + align:start position:0% +change in direction you may not know the +mass or the charge but you can get the + + align:start position:0% +mass or the charge but you can get the + + + align:start position:0% +mass or the charge but you can get the +mass-to-charge ratio because if you guys + + align:start position:0% +mass-to-charge ratio because if you guys + + + align:start position:0% +mass-to-charge ratio because if you guys +remember from 802 from electricity and + + align:start position:0% +remember from 802 from electricity and + + + align:start position:0% +remember from 802 from electricity and +magnetism as a charged particle passes + + align:start position:0% +magnetism as a charged particle passes + + + align:start position:0% +magnetism as a charged particle passes +through an electric field its deflected + + align:start position:0% +through an electric field its deflected + + + align:start position:0% +through an electric field its deflected +and the amount of that deflection or the + + align:start position:0% +and the amount of that deflection or the + + + align:start position:0% +and the amount of that deflection or the +curvature is based on the mass-to-charge + + align:start position:0% +curvature is based on the mass-to-charge + + + align:start position:0% +curvature is based on the mass-to-charge +ratio so we Chadwick knew that electrons + + align:start position:0% +ratio so we Chadwick knew that electrons + + + align:start position:0% +ratio so we Chadwick knew that electrons +existed this was a known thing as well + + align:start position:0% +existed this was a known thing as well + + + align:start position:0% +existed this was a known thing as well +as alpha beta and gamma rays so the + + align:start position:0% +as alpha beta and gamma rays so the + + + align:start position:0% +as alpha beta and gamma rays so the +electrons that came out of the nucleus + + align:start position:0% +electrons that came out of the nucleus + + + align:start position:0% +electrons that came out of the nucleus +were later renamed beta rays and at this + + align:start position:0% +were later renamed beta rays and at this + + + align:start position:0% +were later renamed beta rays and at this +around the same time Ernest Rutherford + + align:start position:0% +around the same time Ernest Rutherford + + + align:start position:0% +around the same time Ernest Rutherford +and Paul Villard working in Canada and + + align:start position:0% +and Paul Villard working in Canada and + + + align:start position:0% +and Paul Villard working in Canada and +France discovered that there are some + + align:start position:0% +France discovered that there are some + + + align:start position:0% +France discovered that there are some +heavy charged particles that have very + + align:start position:0% +heavy charged particles that have very + + + align:start position:0% +heavy charged particles that have very +little penetrating power while Paul + + align:start position:0% +little penetrating power while Paul + + + align:start position:0% +little penetrating power while Paul +Villard discovered that there are some + + align:start position:0% +Villard discovered that there are some + + + align:start position:0% +Villard discovered that there are some +other radiations they think he called it + + align:start position:0% +other radiations they think he called it + + + align:start position:0% +other radiations they think he called it +produced by disintegration of nuclei + + align:start position:0% +produced by disintegration of nuclei + + + align:start position:0% +produced by disintegration of nuclei +that have very high penetrating power + + align:start position:0% +that have very high penetrating power + + + align:start position:0% +that have very high penetrating power +and they named them alpha beta gamma in + + align:start position:0% +and they named them alpha beta gamma in + + + align:start position:0% +and they named them alpha beta gamma in +order of their penetrating power or + + align:start position:0% +order of their penetrating power or + + + align:start position:0% +order of their penetrating power or +their range and so it was later figured + + align:start position:0% +their range and so it was later figured + + + align:start position:0% +their range and so it was later figured +out that these were also high-energy + + align:start position:0% +out that these were also high-energy + + + align:start position:0% +out that these were also high-energy +photons so gamma once this is something + + align:start position:0% +photons so gamma once this is something + + + align:start position:0% +photons so gamma once this is something +to note is that gamma rays x-rays light + + align:start position:0% +to note is that gamma rays x-rays light + + + align:start position:0% +to note is that gamma rays x-rays light +whatever it's all photons however once + + align:start position:0% +whatever it's all photons however once + + + align:start position:0% +whatever it's all photons however once +this pops back up gamma rays emanate + + align:start position:0% +this pops back up gamma rays emanate + + + align:start position:0% +this pops back up gamma rays emanate +from the nucleus so when we refer to a + + align:start position:0% +from the nucleus so when we refer to a + + + align:start position:0% +from the nucleus so when we refer to a +gamma ray we mean a photon that came out + + align:start position:0% +gamma ray we mean a photon that came out + + + align:start position:0% +gamma ray we mean a photon that came out +of a nuclear interaction or a nuclear + + align:start position:0% +of a nuclear interaction or a nuclear + + + align:start position:0% +of a nuclear interaction or a nuclear +disintegration not an electron + + align:start position:0% +disintegration not an electron + + + align:start position:0% +disintegration not an electron +transition so this is one this is what + + align:start position:0% +transition so this is one this is what + + + align:start position:0% +transition so this is one this is what +makes a gamma ray a gamma ray is where + + align:start position:0% +makes a gamma ray a gamma ray is where + + + align:start position:0% +makes a gamma ray a gamma ray is where +it comes from + + align:start position:0% +it comes from + + + align:start position:0% +it comes from +otherwise it's it's a photon behaves + + align:start position:0% +otherwise it's it's a photon behaves + + + align:start position:0% +otherwise it's it's a photon behaves +just like any photons so what did + + align:start position:0% +just like any photons so what did + + + align:start position:0% +just like any photons so what did +Chadwick see in 1932 this is the first + + align:start position:0% +Chadwick see in 1932 this is the first + + + align:start position:0% +Chadwick see in 1932 this is the first +one-page article that he sent out to + + align:start position:0% +one-page article that he sent out to + + + align:start position:0% +one-page article that he sent out to +nature to say I found something weird so + + align:start position:0% +nature to say I found something weird so + + + align:start position:0% +nature to say I found something weird so +he found out that when you take alpha + + align:start position:0% +he found out that when you take alpha + + + align:start position:0% +he found out that when you take alpha +particles from polonium so let + + align:start position:0% +particles from polonium so let + + + align:start position:0% +particles from polonium so let +say we had a source of polonium sending + + align:start position:0% +say we had a source of polonium sending + + + align:start position:0% +say we had a source of polonium sending +off alpha particles which haven't told + + align:start position:0% +off alpha particles which haven't told + + + align:start position:0% +off alpha particles which haven't told +you what they are yet emits a radiation + + align:start position:0% +you what they are yet emits a radiation + + + align:start position:0% +you what they are yet emits a radiation +of great penetrating power + + align:start position:0% +of great penetrating power + + + align:start position:0% +of great penetrating power +when it hits a foil of beryllium and it + + align:start position:0% +when it hits a foil of beryllium and it + + + align:start position:0% +when it hits a foil of beryllium and it +was not known what these things were so + + align:start position:0% +was not known what these things were so + + + align:start position:0% +was not known what these things were so +in goes the alphas to beryllium + + align:start position:0% +in goes the alphas to beryllium + + + align:start position:0% +in goes the alphas to beryllium +something happens and something comes + + align:start position:0% +something happens and something comes + + + align:start position:0% +something happens and something comes +streaming out that couldn't be explained + + align:start position:0% +streaming out that couldn't be explained + + + align:start position:0% +streaming out that couldn't be explained +by current theories it was also noticed + + align:start position:0% +by current theories it was also noticed + + + align:start position:0% +by current theories it was also noticed +that when hydrogen was placed in front + + align:start position:0% +that when hydrogen was placed in front + + + align:start position:0% +that when hydrogen was placed in front +of it when a piece of hydrogen in the + + align:start position:0% +of it when a piece of hydrogen in the + + + align:start position:0% +of it when a piece of hydrogen in the +form of wax which contains a lot of + + align:start position:0% +form of wax which contains a lot of + + + align:start position:0% +form of wax which contains a lot of +hydrogen was put in front of it the + + align:start position:0% +hydrogen was put in front of it the + + + align:start position:0% +hydrogen was put in front of it the +amount of ionization increased as + + align:start position:0% +amount of ionization increased as + + + align:start position:0% +amount of ionization increased as +measured by what's called an ionization + + align:start position:0% +measured by what's called an ionization + + + align:start position:0% +measured by what's called an ionization +chamber and a no silly graph nothing + + align:start position:0% +chamber and a no silly graph nothing + + + align:start position:0% +chamber and a no silly graph nothing +more than a almost sealed chamber a + + align:start position:0% +more than a almost sealed chamber a + + + align:start position:0% +more than a almost sealed chamber a +piston with some charge on it that would + + align:start position:0% +piston with some charge on it that would + + + align:start position:0% +piston with some charge on it that would +then deflect as it were to pick up + + align:start position:0% +then deflect as it were to pick up + + + align:start position:0% +then deflect as it were to pick up +positive or negative charges it would + + align:start position:0% +positive or negative charges it would + + + align:start position:0% +positive or negative charges it would +move inwards or outwards and send a + + align:start position:0% +move inwards or outwards and send a + + + align:start position:0% +move inwards or outwards and send a +signal an electrical signal to something + + align:start position:0% +signal an electrical signal to something + + + align:start position:0% +signal an electrical signal to something +like an oscilloscope so this was a way + + align:start position:0% +like an oscilloscope so this was a way + + + align:start position:0% +like an oscilloscope so this was a way +that you could figure out how many ions + + align:start position:0% +that you could figure out how many ions + + + align:start position:0% +that you could figure out how many ions +were created by this highly penetrating + + align:start position:0% +were created by this highly penetrating + + + align:start position:0% +were created by this highly penetrating +radiation interacting in the ionization + + align:start position:0% +radiation interacting in the ionization + + + align:start position:0% +radiation interacting in the ionization +chamber and the estimated that with the + + align:start position:0% +chamber and the estimated that with the + + + align:start position:0% +chamber and the estimated that with the +old theories if this highly penetrating + + align:start position:0% +old theories if this highly penetrating + + + align:start position:0% +old theories if this highly penetrating +thing were a photon or a gamma ray it + + align:start position:0% +thing were a photon or a gamma ray it + + + align:start position:0% +thing were a photon or a gamma ray it +would have to have an energy of 50 times + + align:start position:0% +would have to have an energy of 50 times + + + align:start position:0% +would have to have an energy of 50 times +10 to the 6 electron volts or fifty MeV + + align:start position:0% +10 to the 6 electron volts or fifty MeV + + + align:start position:0% +10 to the 6 electron volts or fifty MeV +he said okay well if that's to be + + align:start position:0% +he said okay well if that's to be + + + align:start position:0% +he said okay well if that's to be +basically the experimental observation + + align:start position:0% +basically the experimental observation + + + align:start position:0% +basically the experimental observation +say a fifty MeV photon must be + + align:start position:0% +say a fifty MeV photon must be + + + align:start position:0% +say a fifty MeV photon must be +responsible for the ionizations that we + + align:start position:0% +responsible for the ionizations that we + + + align:start position:0% +responsible for the ionizations that we +saw and so again this is what the + + align:start position:0% +saw and so again this is what the + + + align:start position:0% +saw and so again this is what the +experiment looks like where you've got + + align:start position:0% +experiment looks like where you've got + + + align:start position:0% +experiment looks like where you've got +polonium source naturally emitting alpha + + align:start position:0% +polonium source naturally emitting alpha + + + align:start position:0% +polonium source naturally emitting alpha +rays they hit a foil of beryllium they + + align:start position:0% +rays they hit a foil of beryllium they + + + align:start position:0% +rays they hit a foil of beryllium they +produce what he did not know at the time + + align:start position:0% +produce what he did not know at the time + + + align:start position:0% +produce what he did not know at the time +was neutrons we actually do know that + + align:start position:0% +was neutrons we actually do know that + + + align:start position:0% +was neutrons we actually do know that +beryllium produces neutrons pretty well + + align:start position:0% +beryllium produces neutrons pretty well + + + align:start position:0% +beryllium produces neutrons pretty well +beryllium is an interesting Neutron + + align:start position:0% +beryllium is an interesting Neutron + + + align:start position:0% +beryllium is an interesting Neutron +multipliers undergoes what's called an N + + align:start position:0% +multipliers undergoes what's called an N + + + align:start position:0% +multipliers undergoes what's called an N +to n reaction where one Neutron comes in + + align:start position:0% +to n reaction where one Neutron comes in + + + align:start position:0% +to n reaction where one Neutron comes in +two neutrons can come out and it + + align:start position:0% +two neutrons can come out and it + + + align:start position:0% +two neutrons can come out and it +translates into something else and we'll + + align:start position:0% +translates into something else and we'll + + + align:start position:0% +translates into something else and we'll +go over what this notation means what + + align:start position:0% +go over what this notation means what + + + align:start position:0% +go over what this notation means what +these nuclear reactions mean if you + + align:start position:0% +these nuclear reactions mean if you + + + align:start position:0% +these nuclear reactions mean if you +don't understand it + + align:start position:0% +don't understand it + + + align:start position:0% +don't understand it +don't worry the whole point of today is + + align:start position:0% +don't worry the whole point of today is + + + align:start position:0% +don't worry the whole point of today is +to open up questions that will spend the + + align:start position:0% +to open up questions that will spend the + + + align:start position:0% +to open up questions that will spend the +rest of the semester closing and + + align:start position:0% +rest of the semester closing and + + + align:start position:0% +rest of the semester closing and +answering + + align:start position:0% +answering + + + align:start position:0% +answering +so again if you're lost don't worry it's + + align:start position:0% +so again if you're lost don't worry it's + + + align:start position:0% +so again if you're lost don't worry it's +the first day of class and it's your + + align:start position:0% +the first day of class and it's your + + + align:start position:0% +the first day of class and it's your +first day of modern physics so not to + + align:start position:0% +first day of modern physics so not to + + + align:start position:0% +first day of modern physics so not to +worry this is an actual picture of what + + align:start position:0% +worry this is an actual picture of what + + + align:start position:0% +worry this is an actual picture of what +it looked like in the paper a simple + + align:start position:0% +it looked like in the paper a simple + + + align:start position:0% +it looked like in the paper a simple +polonium source on a disk that was made + + align:start position:0% +polonium source on a disk that was made + + + align:start position:0% +polonium source on a disk that was made +by the natural decomposition of radium + + align:start position:0% +by the natural decomposition of radium + + + align:start position:0% +by the natural decomposition of radium +into polonium a piece of beryllium a + + align:start position:0% +into polonium a piece of beryllium a + + + align:start position:0% +into polonium a piece of beryllium a +vacuum chamber because it was already + + align:start position:0% +vacuum chamber because it was already + + + align:start position:0% +vacuum chamber because it was already +known that the alpha particles coming + + align:start position:0% +known that the alpha particles coming + + + align:start position:0% +known that the alpha particles coming +from polonium have an extremely short + + align:start position:0% +from polonium have an extremely short + + + align:start position:0% +from polonium have an extremely short +range we're going to figure out why as + + align:start position:0% +range we're going to figure out why as + + + align:start position:0% +range we're going to figure out why as +part of this class but without that + + align:start position:0% +part of this class but without that + + + align:start position:0% +part of this class but without that +vacuum there the alpha particles + + align:start position:0% +vacuum there the alpha particles + + + align:start position:0% +vacuum there the alpha particles +wouldn't make it to the per ileum so + + align:start position:0% +wouldn't make it to the per ileum so + + + align:start position:0% +wouldn't make it to the per ileum so +that much was known what wasn't known + + align:start position:0% +that much was known what wasn't known + + + align:start position:0% +that much was known what wasn't known +was why are we getting so many + + align:start position:0% +was why are we getting so many + + + align:start position:0% +was why are we getting so many +ionizations they attributed it to what + + align:start position:0% +ionizations they attributed it to what + + + align:start position:0% +ionizations they attributed it to what +they called a process similar to the + + align:start position:0% +they called a process similar to the + + + align:start position:0% +they called a process similar to the +Compton effect to tell you what that is + + align:start position:0% +Compton effect to tell you what that is + + + align:start position:0% +Compton effect to tell you what that is +in 1923 Arthur Compton figured out among + + align:start position:0% +in 1923 Arthur Compton figured out among + + + align:start position:0% +in 1923 Arthur Compton figured out among +other things Compton scattering where a + + align:start position:0% +other things Compton scattering where a + + + align:start position:0% +other things Compton scattering where a +photon can strike an electron the photon + + align:start position:0% +photon can strike an electron the photon + + + align:start position:0% +photon can strike an electron the photon +changes energy the electron picks up + + align:start position:0% +changes energy the electron picks up + + + align:start position:0% +changes energy the electron picks up +some energy they exit at very well-known + + align:start position:0% +some energy they exit at very well-known + + + align:start position:0% +some energy they exit at very well-known +angles and they transfer very well-known + + align:start position:0% +angles and they transfer very well-known + + + align:start position:0% +angles and they transfer very well-known +amounts of energy so this is how they + + align:start position:0% +amounts of energy so this is how they + + + align:start position:0% +amounts of energy so this is how they +knew how much energy the photon if it + + align:start position:0% +knew how much energy the photon if it + + + align:start position:0% +knew how much energy the photon if it +were to exist should have and they said + + align:start position:0% +were to exist should have and they said + + + align:start position:0% +were to exist should have and they said +the process was analogous to Compton + + align:start position:0% +the process was analogous to Compton + + + align:start position:0% +the process was analogous to Compton +scattering because they said in this + + align:start position:0% +scattering because they said in this + + + align:start position:0% +scattering because they said in this +case a proton would be ejected it would + + align:start position:0% +case a proton would be ejected it would + + + align:start position:0% +case a proton would be ejected it would +take a lot of energy to eject a proton + + align:start position:0% +take a lot of energy to eject a proton + + + align:start position:0% +take a lot of energy to eject a proton +using a photon and Chadwick saw this and + + align:start position:0% +using a photon and Chadwick saw this and + + + align:start position:0% +using a photon and Chadwick saw this and +said well if we ascribe this phenomenon + + align:start position:0% +said well if we ascribe this phenomenon + + + align:start position:0% +said well if we ascribe this phenomenon +to a Compton recoil we should see about + + align:start position:0% +to a Compton recoil we should see about + + + align:start position:0% +to a Compton recoil we should see about +10,000 ions we actually saw about 30,000 + + align:start position:0% +10,000 ions we actually saw about 30,000 + + + align:start position:0% +10,000 ions we actually saw about 30,000 +so there is more ionization going on + + align:start position:0% +so there is more ionization going on + + + align:start position:0% +so there is more ionization going on +than can be explained by what's going on + + align:start position:0% +than can be explained by what's going on + + + align:start position:0% +than can be explained by what's going on +in addition those protons should have + + align:start position:0% +in addition those protons should have + + + align:start position:0% +in addition those protons should have +arranged an air of about 1.3 millimeters + + align:start position:0% +arranged an air of about 1.3 millimeters + + + align:start position:0% +arranged an air of about 1.3 millimeters +and they saw much more so this says + + align:start position:0% +and they saw much more so this says + + + align:start position:0% +and they saw much more so this says +something simple is theory and + + align:start position:0% +something simple is theory and + + + align:start position:0% +something simple is theory and +experiment don't match there's got to be + + align:start position:0% +experiment don't match there's got to be + + + align:start position:0% +experiment don't match there's got to be +a different theoretical explanation if + + align:start position:0% +a different theoretical explanation if + + + align:start position:0% +a different theoretical explanation if +the experiment was correct and so + + align:start position:0% +the experiment was correct and so + + + align:start position:0% +the experiment was correct and so +finally what I love the last sentence in + + align:start position:0% +finally what I love the last sentence in + + + align:start position:0% +finally what I love the last sentence in +this the quantum hypothesis a quantum + + align:start position:0% +this the quantum hypothesis a quantum + + + align:start position:0% +this the quantum hypothesis a quantum +was the way they referred to a photon it + + align:start position:0% +was the way they referred to a photon it + + + align:start position:0% +was the way they referred to a photon it +was called the quantum back then a + + align:start position:0% +was called the quantum back then a + + + align:start position:0% +was called the quantum back then a +little packet of energy can + + align:start position:0% +little packet of energy can + + + align:start position:0% +little packet of energy can +we be upheld if we forget about + + align:start position:0% +we be upheld if we forget about + + + align:start position:0% +we be upheld if we forget about +conservation of energy and momentum now + + align:start position:0% +conservation of energy and momentum now + + + align:start position:0% +conservation of energy and momentum now +I'll ask you guys from 801 and 802 so + + align:start position:0% +I'll ask you guys from 801 and 802 so + + + align:start position:0% +I'll ask you guys from 801 and 802 so +Shawn when can you cook Wendy can you + + align:start position:0% +Shawn when can you cook Wendy can you + + + align:start position:0% +Shawn when can you cook Wendy can you +throw out energy and momentum + + align:start position:0% +throw out energy and momentum + + + align:start position:0% +throw out energy and momentum +conservation that's pretty much Brett + + align:start position:0% +conservation that's pretty much Brett + + + align:start position:0% +conservation that's pretty much Brett +you can't a situation probably wasn't + + align:start position:0% +you can't a situation probably wasn't + + + align:start position:0% +you can't a situation probably wasn't +given to you where you can just throw + + align:start position:0% +given to you where you can just throw + + + align:start position:0% +given to you where you can just throw +away conservation of momentum and energy + + align:start position:0% +away conservation of momentum and energy + + + align:start position:0% +away conservation of momentum and energy +in fact nature gives us three quantities + + align:start position:0% +in fact nature gives us three quantities + + + align:start position:0% +in fact nature gives us three quantities +that we can measure and conserve mass + + align:start position:0% +that we can measure and conserve mass + + + align:start position:0% +that we can measure and conserve mass +momentum and energy and throughout this + + align:start position:0% +momentum and energy and throughout this + + + align:start position:0% +momentum and energy and throughout this +course if something's not conserved + + align:start position:0% +course if something's not conserved + + + align:start position:0% +course if something's not conserved +you've probably got the math of the + + align:start position:0% +you've probably got the math of the + + + align:start position:0% +you've probably got the math of the +physics wrong so this is something to + + align:start position:0% +physics wrong so this is something to + + + align:start position:0% +physics wrong so this is something to +remember throughout the course in our + + align:start position:0% +remember throughout the course in our + + + align:start position:0% +remember throughout the course in our +derivation and in your problem sets is + + align:start position:0% +derivation and in your problem sets is + + + align:start position:0% +derivation and in your problem sets is +conserve mass conserve momentum conserve + + align:start position:0% +conserve mass conserve momentum conserve + + + align:start position:0% +conserve mass conserve momentum conserve +energy just like what was taught in 801 + + align:start position:0% +energy just like what was taught in 801 + + + align:start position:0% +energy just like what was taught in 801 +in 802 so I'll call your answer correct + + align:start position:0% +in 802 so I'll call your answer correct + + + align:start position:0% +in 802 so I'll call your answer correct +you don't remember a situation because + + align:start position:0% +you don't remember a situation because + + + align:start position:0% +you don't remember a situation because +well didn't exist and that's what + + align:start position:0% +well didn't exist and that's what + + + align:start position:0% +well didn't exist and that's what +Chadwick notice he said theory and + + align:start position:0% +Chadwick notice he said theory and + + + align:start position:0% +Chadwick notice he said theory and +experiment don't work unless we throw + + align:start position:0% +experiment don't work unless we throw + + + align:start position:0% +experiment don't work unless we throw +out conservation of energy and momentum + + align:start position:0% +out conservation of energy and momentum + + + align:start position:0% +out conservation of energy and momentum +whether this was a kind of + + align:start position:0% +whether this was a kind of + + + align:start position:0% +whether this was a kind of +passive-aggressive thing to say well + + align:start position:0% +passive-aggressive thing to say well + + + align:start position:0% +passive-aggressive thing to say well +this clearly can't exist or he was + + align:start position:0% +this clearly can't exist or he was + + + align:start position:0% +this clearly can't exist or he was +suggesting maybe it doesn't work I don't + + align:start position:0% +suggesting maybe it doesn't work I don't + + + align:start position:0% +suggesting maybe it doesn't work I don't +know I wasn't there but later on about a + + align:start position:0% +know I wasn't there but later on about a + + + align:start position:0% +know I wasn't there but later on about a +year later he published a follow-on + + align:start position:0% +year later he published a follow-on + + + align:start position:0% +year later he published a follow-on +paper + + align:start position:0% +paper + + + align:start position:0% +paper +confirming the existence of a neutron by + + align:start position:0% +confirming the existence of a neutron by + + + align:start position:0% +confirming the existence of a neutron by +reconciling these differences in theory + + align:start position:0% +reconciling these differences in theory + + + align:start position:0% +reconciling these differences in theory +and experiment so he restated what he + + align:start position:0% +and experiment so he restated what he + + + align:start position:0% +and experiment so he restated what he +saw before this is the first paragraph + + align:start position:0% +saw before this is the first paragraph + + + align:start position:0% +saw before this is the first paragraph +of it and again said that radiation + + align:start position:0% +of it and again said that radiation + + + align:start position:0% +of it and again said that radiation +excited in beryllium whatever happens + + align:start position:0% +excited in beryllium whatever happens + + + align:start position:0% +excited in beryllium whatever happens +after the alpha particle came out at a + + align:start position:0% +after the alpha particle came out at a + + + align:start position:0% +after the alpha particle came out at a +highly penetrating radiation distinctly + + align:start position:0% +highly penetrating radiation distinctly + + + align:start position:0% +highly penetrating radiation distinctly +greater than that of any gamma radiation + + align:start position:0% +greater than that of any gamma radiation + + + align:start position:0% +greater than that of any gamma radiation +found from radioactive elements + + align:start position:0% +found from radioactive elements + + + align:start position:0% +found from radioactive elements +something's different and I want us to + + align:start position:0% +something's different and I want us to + + + align:start position:0% +something's different and I want us to +take a second to digest this this is the + + align:start position:0% +take a second to digest this this is the + + + align:start position:0% +take a second to digest this this is the +part I actually want you guys to read so + + align:start position:0% +part I actually want you guys to read so + + + align:start position:0% +part I actually want you guys to read so +take a minute and read through some of + + align:start position:0% +take a minute and read through some of + + + align:start position:0% +take a minute and read through some of +the stuff and then we'll begin + + align:start position:0% +the stuff and then we'll begin + + + align:start position:0% +the stuff and then we'll begin +explaining his argument + + align:start position:0% + + + + align:start position:0% + +so let me know when you guys are done + + align:start position:0% +so let me know when you guys are done + + + align:start position:0% +so let me know when you guys are done +reading + + align:start position:0% + + + + align:start position:0% + +okay I see some folks starting to look + + align:start position:0% +okay I see some folks starting to look + + + align:start position:0% +okay I see some folks starting to look +down so let's take this apart and figure + + align:start position:0% +down so let's take this apart and figure + + + align:start position:0% +down so let's take this apart and figure +out what was Chadwick saying he was + + align:start position:0% +out what was Chadwick saying he was + + + align:start position:0% +out what was Chadwick saying he was +saying that if a quantum was responsible + + align:start position:0% +saying that if a quantum was responsible + + + align:start position:0% +saying that if a quantum was responsible +for this energy a photon then we can + + align:start position:0% +for this energy a photon then we can + + + align:start position:0% +for this energy a photon then we can +write a nuclear reaction I'll write it + + align:start position:0% +write a nuclear reaction I'll write it + + + align:start position:0% +write a nuclear reaction I'll write it +in the notation that we use now which + + align:start position:0% +in the notation that we use now which + + + align:start position:0% +in the notation that we use now which +would be beryllium 9 the only naturally + + align:start position:0% +would be beryllium 9 the only naturally + + + align:start position:0% +would be beryllium 9 the only naturally +occurring isotope of beryllium plus an + + align:start position:0% +occurring isotope of beryllium plus an + + + align:start position:0% +occurring isotope of beryllium plus an +alpha particle would lead to carbon 13 + + align:start position:0% +alpha particle would lead to carbon 13 + + + align:start position:0% +alpha particle would lead to carbon 13 +plus a gamma ray and that gamma ray + + align:start position:0% +plus a gamma ray and that gamma ray + + + align:start position:0% +plus a gamma ray and that gamma ray +would take away the energy from this + + align:start position:0% +would take away the energy from this + + + align:start position:0% +would take away the energy from this +reaction so now we can start to figure + + align:start position:0% +reaction so now we can start to figure + + + align:start position:0% +reaction so now we can start to figure +out is energy conserved could this gamma + + align:start position:0% +out is energy conserved could this gamma + + + align:start position:0% +out is energy conserved could this gamma +ray actually exist and if it does + + align:start position:0% +ray actually exist and if it does + + + align:start position:0% +ray actually exist and if it does +doesn't account for the ionizations that + + align:start position:0% +doesn't account for the ionizations that + + + align:start position:0% +doesn't account for the ionizations that +Chadwick saw so for each of these + + align:start position:0% +Chadwick saw so for each of these + + + align:start position:0% +Chadwick saw so for each of these +isotopes we know a few different + + align:start position:0% +isotopes we know a few different + + + align:start position:0% +isotopes we know a few different +quantities we know what's called its + + align:start position:0% +quantities we know what's called its + + + align:start position:0% +quantities we know what's called its +rest mass energy which is its rest mass + + align:start position:0% +rest mass energy which is its rest mass + + + align:start position:0% +rest mass energy which is its rest mass +times speed of light squared this should + + align:start position:0% +times speed of light squared this should + + + align:start position:0% +times speed of light squared this should +look familiar to everyone I've seen it + + align:start position:0% +look familiar to everyone I've seen it + + + align:start position:0% +look familiar to everyone I've seen it +on t-shirts all over campus and it may + + align:start position:0% +on t-shirts all over campus and it may + + + align:start position:0% +on t-shirts all over campus and it may +take two or three weeks to really wrap + + align:start position:0% +take two or three weeks to really wrap + + + align:start position:0% +take two or three weeks to really wrap +your head around what Einstein's + + align:start position:0% +your head around what Einstein's + + + align:start position:0% +your head around what Einstein's +equation really means is that mass and + + align:start position:0% +equation really means is that mass and + + + align:start position:0% +equation really means is that mass and +energy are equivalent you can express + + align:start position:0% +energy are equivalent you can express + + + align:start position:0% +energy are equivalent you can express +mass in terms of energy and vice versa + + align:start position:0% +mass in terms of energy and vice versa + + + align:start position:0% +mass in terms of energy and vice versa +and you will be doing so to conserve + + align:start position:0% +and you will be doing so to conserve + + + align:start position:0% +and you will be doing so to conserve +energy and mass in nuclear reactions one + + align:start position:0% +energy and mass in nuclear reactions one + + + align:start position:0% +energy and mass in nuclear reactions one +of which is written right here so if + + align:start position:0% +of which is written right here so if + + + align:start position:0% +of which is written right here so if +each of these things has a given rest + + align:start position:0% +each of these things has a given rest + + + align:start position:0% +each of these things has a given rest +mass energy let's say rest mass energy + + align:start position:0% +mass energy let's say rest mass energy + + + align:start position:0% +mass energy let's say rest mass energy +of beryllium and a rest mass energy of + + align:start position:0% +of beryllium and a rest mass energy of + + + align:start position:0% +of beryllium and a rest mass energy of +an alpha particle and this alpha + + align:start position:0% +an alpha particle and this alpha + + + align:start position:0% +an alpha particle and this alpha +particle maybe had some kinetic energy + + align:start position:0% +particle maybe had some kinetic energy + + + align:start position:0% +particle maybe had some kinetic energy +it was moving pretty fast so we'll give + + align:start position:0% +it was moving pretty fast so we'll give + + + align:start position:0% +it was moving pretty fast so we'll give +that a the symbol T for kinetic energy + + align:start position:0% +that a the symbol T for kinetic energy + + + align:start position:0% +that a the symbol T for kinetic energy +because that's what you're going to see + + align:start position:0% +because that's what you're going to see + + + align:start position:0% +because that's what you're going to see +in your notes and in the reading and + + align:start position:0% +in your notes and in the reading and + + + align:start position:0% +in your notes and in the reading and +everywhere and then this carbon-13 + + align:start position:0% +everywhere and then this carbon-13 + + + align:start position:0% +everywhere and then this carbon-13 +nucleus has got to have a rest mass and + + align:start position:0% +nucleus has got to have a rest mass and + + + align:start position:0% +nucleus has got to have a rest mass and +a kinetic energy and then this gamma ray + + align:start position:0% +a kinetic energy and then this gamma ray + + + align:start position:0% +a kinetic energy and then this gamma ray +is going to have some gamma energy now + + align:start position:0% +is going to have some gamma energy now + + + align:start position:0% +is going to have some gamma energy now +the question is is the mass and energy + + align:start position:0% +the question is is the mass and energy + + + align:start position:0% +the question is is the mass and energy +conserved in this equation what we're + + align:start position:0% +conserved in this equation what we're + + + align:start position:0% +conserved in this equation what we're +actually starting to write is what's + + align:start position:0% +actually starting to write is what's + + + align:start position:0% +actually starting to write is what's +called the Q equation or the sort of + + align:start position:0% +called the Q equation or the sort of + + + align:start position:0% +called the Q equation or the sort of +universal mass and energy balance for + + align:start position:0% +universal mass and energy balance for + + + align:start position:0% +universal mass and energy balance for +any kind of + + align:start position:0% +any kind of + + + align:start position:0% +any kind of +nuclear reaction so let's say we have a + + align:start position:0% +nuclear reaction so let's say we have a + + + align:start position:0% +nuclear reaction so let's say we have a +large initial nucleus I and some small + + align:start position:0% +large initial nucleus I and some small + + + align:start position:0% +large initial nucleus I and some small +particle I'm moving at it with some + + align:start position:0% +particle I'm moving at it with some + + + align:start position:0% +particle I'm moving at it with some +great speed and after some reaction + + align:start position:0% +great speed and after some reaction + + + align:start position:0% +great speed and after some reaction +occurs you have a small final particle + + align:start position:0% +occurs you have a small final particle + + + align:start position:0% +occurs you have a small final particle +leaving and a different large final + + align:start position:0% +leaving and a different large final + + + align:start position:0% +leaving and a different large final +particle relieving they don't + + align:start position:0% +particle relieving they don't + + + align:start position:0% +particle relieving they don't +necessarily have to be the same let's + + align:start position:0% +necessarily have to be the same let's + + + align:start position:0% +necessarily have to be the same let's +give these particles designations one + + align:start position:0% +give these particles designations one + + + align:start position:0% +give these particles designations one +two three and four in the end we should + + align:start position:0% +two three and four in the end we should + + + align:start position:0% +two three and four in the end we should +be able to write the difference in + + align:start position:0% +be able to write the difference in + + + align:start position:0% +be able to write the difference in +either total energy or total mass of the + + align:start position:0% +either total energy or total mass of the + + + align:start position:0% +either total energy or total mass of the +system as this value Q Q is let's say + + align:start position:0% +system as this value Q Q is let's say + + + align:start position:0% +system as this value Q Q is let's say +the amount of energy that turns into + + align:start position:0% +the amount of energy that turns into + + + align:start position:0% +the amount of energy that turns into +mass or vice-versa so let's say energy + + align:start position:0% +mass or vice-versa so let's say energy + + + align:start position:0% +mass or vice-versa so let's say energy +transfer and so if we start writing some + + align:start position:0% +transfer and so if we start writing some + + + align:start position:0% +transfer and so if we start writing some +mass conservation equation we can say + + align:start position:0% +mass conservation equation we can say + + + align:start position:0% +mass conservation equation we can say +that the mass of nucleus 1 plus the mass + + align:start position:0% +that the mass of nucleus 1 plus the mass + + + align:start position:0% +that the mass of nucleus 1 plus the mass +of nucleus 2 should equal the mass of + + align:start position:0% +of nucleus 2 should equal the mass of + + + align:start position:0% +of nucleus 2 should equal the mass of +nucleus 3 plus the mass of nucleus 4 + + align:start position:0% +nucleus 3 plus the mass of nucleus 4 + + + align:start position:0% +nucleus 3 plus the mass of nucleus 4 +plus however much energy from nuclei 1 + + align:start position:0% +plus however much energy from nuclei 1 + + + align:start position:0% +plus however much energy from nuclei 1 +and 2 turned into energy into 3 & 4 we + + align:start position:0% +and 2 turned into energy into 3 & 4 we + + + align:start position:0% +and 2 turned into energy into 3 & 4 we +can also write the same thing for their + + align:start position:0% +can also write the same thing for their + + + align:start position:0% +can also write the same thing for their +kinetic energies in this case the finals + + align:start position:0% +kinetic energies in this case the finals + + + align:start position:0% +kinetic energies in this case the finals +are on the end so I'm sorry I should use + + align:start position:0% +are on the end so I'm sorry I should use + + + align:start position:0% +are on the end so I'm sorry I should use +T for kinetic energy not + + align:start position:0% + + + + align:start position:0% + +so what this is saying is that if some + + align:start position:0% +so what this is saying is that if some + + + align:start position:0% +so what this is saying is that if some +mass has turned into energy at the end + + align:start position:0% +mass has turned into energy at the end + + + align:start position:0% +mass has turned into energy at the end +that energy had to come from somewhere + + align:start position:0% +that energy had to come from somewhere + + + align:start position:0% +that energy had to come from somewhere +it had to come from the initial kinetic + + align:start position:0% +it had to come from the initial kinetic + + + align:start position:0% +it had to come from the initial kinetic +energy or conversion to mass to energy + + align:start position:0% +energy or conversion to mass to energy + + + align:start position:0% +energy or conversion to mass to energy +from this reaction and so notice that + + align:start position:0% +from this reaction and so notice that + + + align:start position:0% +from this reaction and so notice that +now you can actually express the masses + + align:start position:0% +now you can actually express the masses + + + align:start position:0% +now you can actually express the masses +of the nuclei in terms of their energy + + align:start position:0% +of the nuclei in terms of their energy + + + align:start position:0% +of the nuclei in terms of their energy +if their initial and final kinetic + + align:start position:0% +if their initial and final kinetic + + + align:start position:0% +if their initial and final kinetic +energies and this right here is what + + align:start position:0% +energies and this right here is what + + + align:start position:0% +energies and this right here is what +we're going to be spending the first two + + align:start position:0% +we're going to be spending the first two + + + align:start position:0% +we're going to be spending the first two +or three weeks deriving using and + + align:start position:0% +or three weeks deriving using and + + + align:start position:0% +or three weeks deriving using and +exploring in order to balance nuclear + + align:start position:0% +exploring in order to balance nuclear + + + align:start position:0% +exploring in order to balance nuclear +reactions and explain why they are the + + align:start position:0% +reactions and explain why they are the + + + align:start position:0% +reactions and explain why they are the +way they are so let's make sure we'll + + align:start position:0% +way they are so let's make sure we'll + + + align:start position:0% +way they are so let's make sure we'll +keep this nuclear reaction up here + + align:start position:0% +keep this nuclear reaction up here + + + align:start position:0% +keep this nuclear reaction up here +because Chadwick proposed a different + + align:start position:0% +because Chadwick proposed a different + + + align:start position:0% +because Chadwick proposed a different +one to explain what he saw and some of + + align:start position:0% +one to explain what he saw and some of + + + align:start position:0% +one to explain what he saw and some of +the evidence for this was that he put + + align:start position:0% +the evidence for this was that he put + + + align:start position:0% +the evidence for this was that he put +some aluminum foil in between the + + align:start position:0% +some aluminum foil in between the + + + align:start position:0% +some aluminum foil in between the +beryllium where things were being + + align:start position:0% +beryllium where things were being + + + align:start position:0% +beryllium where things were being +liberated and the ionization chamber and + + align:start position:0% +liberated and the ionization chamber and + + + align:start position:0% +liberated and the ionization chamber and +oscilloscope or a Silla graph as he + + align:start position:0% +oscilloscope or a Silla graph as he + + + align:start position:0% +oscilloscope or a Silla graph as he +liked to call it and that way by putting + + align:start position:0% +liked to call it and that way by putting + + + align:start position:0% +liked to call it and that way by putting +more and more pieces of foil in there + + align:start position:0% +more and more pieces of foil in there + + + align:start position:0% +more and more pieces of foil in there +you can deduce what's called the range + + align:start position:0% +you can deduce what's called the range + + + align:start position:0% +you can deduce what's called the range +or the distance that the radiation will + + align:start position:0% +or the distance that the radiation will + + + align:start position:0% +or the distance that the radiation will +travel before it stops by losing energy + + align:start position:0% +travel before it stops by losing energy + + + align:start position:0% +travel before it stops by losing energy +through a whole host of different + + align:start position:0% +through a whole host of different + + + align:start position:0% +through a whole host of different +processes that we'll be working through + + align:start position:0% +processes that we'll be working through + + + align:start position:0% +processes that we'll be working through +together if this were to be ascribed to + + align:start position:0% +together if this were to be ascribed to + + + align:start position:0% +together if this were to be ascribed to +a proton then it should have had a + + align:start position:0% +a proton then it should have had a + + + align:start position:0% +a proton then it should have had a +certain range in air by this curve B + + align:start position:0% +certain range in air by this curve B + + + align:start position:0% +certain range in air by this curve B +right here instead he found this curve a + + align:start position:0% +right here instead he found this curve a + + + align:start position:0% +right here instead he found this curve a +where things moved about three times + + align:start position:0% +where things moved about three times + + + align:start position:0% +where things moved about three times +farther than could have been explained + + align:start position:0% +farther than could have been explained + + + align:start position:0% +farther than could have been explained +if that were a proton to be liberated by + + align:start position:0% +if that were a proton to be liberated by + + + align:start position:0% +if that were a proton to be liberated by +all this stuff so he's saying okay + + align:start position:0% +all this stuff so he's saying okay + + + align:start position:0% +all this stuff so he's saying okay +something's got more penetrating power + + align:start position:0% +something's got more penetrating power + + + align:start position:0% +something's got more penetrating power +we know now that part of the reason for + + align:start position:0% +we know now that part of the reason for + + + align:start position:0% +we know now that part of the reason for +this is if there's a neutron and there's + + align:start position:0% +this is if there's a neutron and there's + + + align:start position:0% +this is if there's a neutron and there's +no charge on it then it's not going to + + align:start position:0% +no charge on it then it's not going to + + + align:start position:0% +no charge on it then it's not going to +interact with the electrons in matter it + + align:start position:0% +interact with the electrons in matter it + + + align:start position:0% +interact with the electrons in matter it +won't even see them whereas protons or + + align:start position:0% +won't even see them whereas protons or + + + align:start position:0% +won't even see them whereas protons or +any other charged particles will see the + + align:start position:0% +any other charged particles will see the + + + align:start position:0% +any other charged particles will see the +electrons in matter and will interact + + align:start position:0% +electrons in matter and will interact + + + align:start position:0% +electrons in matter and will interact +with the electrons and the nuclei so a + + align:start position:0% +with the electrons and the nuclei so a + + + align:start position:0% +with the electrons and the nuclei so a +little flash forward to say we can + + align:start position:0% +little flash forward to say we can + + + align:start position:0% +little flash forward to say we can +explain this pretty simply with what we + + align:start position:0% +explain this pretty simply with what we + + + align:start position:0% +explain this pretty simply with what we +generally know but this was the first + + align:start position:0% +generally know but this was the first + + + align:start position:0% +generally know but this was the first +time somebody had to come up with the + + align:start position:0% +time somebody had to come up with the + + + align:start position:0% +time somebody had to come up with the +sign of explanation and it was quite + + align:start position:0% +sign of explanation and it was quite + + + align:start position:0% +sign of explanation and it was quite +hard + + align:start position:0% + + + + align:start position:0% + +and so moving on he can say well I know + + align:start position:0% +and so moving on he can say well I know + + + align:start position:0% +and so moving on he can say well I know +what proton should be injected from + + align:start position:0% +what proton should be injected from + + + align:start position:0% +what proton should be injected from +paraffin I know a formula to describe + + align:start position:0% +paraffin I know a formula to describe + + + align:start position:0% +paraffin I know a formula to describe +what quantum or photon energy had to + + align:start position:0% +what quantum or photon energy had to + + + align:start position:0% +what quantum or photon energy had to +create them and then instead he says + + align:start position:0% +create them and then instead he says + + + align:start position:0% +create them and then instead he says +this is where his major hypothesis is + + align:start position:0% +this is where his major hypothesis is + + + align:start position:0% +this is where his major hypothesis is +either we relinquish conservation of + + align:start position:0% +either we relinquish conservation of + + + align:start position:0% +either we relinquish conservation of +energy or no-trump neutron or adopt + + align:start position:0% +energy or no-trump neutron or adopt + + + align:start position:0% +energy or no-trump neutron or adopt +another hypothesis and this was already + + align:start position:0% +another hypothesis and this was already + + + align:start position:0% +another hypothesis and this was already +sort of put forth by Rutherford back in + + align:start position:0% +sort of put forth by Rutherford back in + + + align:start position:0% +sort of put forth by Rutherford back in +the 20s that there may be a neutron but + + align:start position:0% +the 20s that there may be a neutron but + + + align:start position:0% +the 20s that there may be a neutron but +there wasn't any proof and this is what + + align:start position:0% +there wasn't any proof and this is what + + + align:start position:0% +there wasn't any proof and this is what +provided the proof he gave an alternate + + align:start position:0% +provided the proof he gave an alternate + + + align:start position:0% +provided the proof he gave an alternate +nuclear reaction if there were to be a + + align:start position:0% +nuclear reaction if there were to be a + + + align:start position:0% +nuclear reaction if there were to be a +neutron which had roughly the mass of a + + align:start position:0% +neutron which had roughly the mass of a + + + align:start position:0% +neutron which had roughly the mass of a +proton then let's write a second one + + align:start position:0% +proton then let's write a second one + + + align:start position:0% +proton then let's write a second one +down here I'm going to erase these extra + + align:start position:0% +down here I'm going to erase these extra + + + align:start position:0% +down here I'm going to erase these extra +notation and will write the competing + + align:start position:0% +notation and will write the competing + + + align:start position:0% +notation and will write the competing +nuclear reaction below and he said that + + align:start position:0% +nuclear reaction below and he said that + + + align:start position:0% +nuclear reaction below and he said that +let's say we start with beryllium 9 plus + + align:start position:0% +let's say we start with beryllium 9 plus + + + align:start position:0% +let's say we start with beryllium 9 plus +an alpha particle could instead become + + align:start position:0% +an alpha particle could instead become + + + align:start position:0% +an alpha particle could instead become +carbon-12 and a neutron so I'd like to + + align:start position:0% +carbon-12 and a neutron so I'd like to + + + align:start position:0% +carbon-12 and a neutron so I'd like to +ask you guys right now to work this out + + align:start position:0% +ask you guys right now to work this out + + + align:start position:0% +ask you guys right now to work this out +are both of these reactions balanced in + + align:start position:0% +are both of these reactions balanced in + + + align:start position:0% +are both of these reactions balanced in +terms of mass are there the same number + + align:start position:0% +terms of mass are there the same number + + + align:start position:0% +terms of mass are there the same number +of protons neutrons and electrons on + + align:start position:0% +of protons neutrons and electrons on + + + align:start position:0% +of protons neutrons and electrons on +either side and just to let you know an + + align:start position:0% +either side and just to let you know an + + + align:start position:0% +either side and just to let you know an +alpha particle is better known as a + + align:start position:0% +alpha particle is better known as a + + + align:start position:0% +alpha particle is better known as a +helium nucleus so that means that + + align:start position:0% +helium nucleus so that means that + + + align:start position:0% +helium nucleus so that means that +there's two protons there's four protons + + align:start position:0% +there's two protons there's four protons + + + align:start position:0% +there's two protons there's four protons +plus neutrons and beryllium nine has + + align:start position:0% +plus neutrons and beryllium nine has + + + align:start position:0% +plus neutrons and beryllium nine has +four protons and nine protons plus + + align:start position:0% +four protons and nine protons plus + + + align:start position:0% +four protons and nine protons plus +neutrons and carbon-12 has six protons a + + align:start position:0% +neutrons and carbon-12 has six protons a + + + align:start position:0% +neutrons and carbon-12 has six protons a +neutron has zero protons so in each of + + align:start position:0% +neutron has zero protons so in each of + + + align:start position:0% +neutron has zero protons so in each of +these and I'll fill in the other ones + + align:start position:0% +these and I'll fill in the other ones + + + align:start position:0% +these and I'll fill in the other ones +here so that's a four for two and six do + + align:start position:0% +here so that's a four for two and six do + + + align:start position:0% +here so that's a four for two and six do +we have the same number of protons and + + align:start position:0% +we have the same number of protons and + + + align:start position:0% +we have the same number of protons and +neutrons on both sides of both equations + + align:start position:0% + + + + align:start position:0% + +I see a number of heads and one person + + align:start position:0% +I see a number of heads and one person + + + align:start position:0% +I see a number of heads and one person +saying yes we do so both of these + + align:start position:0% +saying yes we do so both of these + + + align:start position:0% +saying yes we do so both of these +reactions are balanced in terms of mass + + align:start position:0% +reactions are balanced in terms of mass + + + align:start position:0% +reactions are balanced in terms of mass +the next thing to do is balance them in + + align:start position:0% +the next thing to do is balance them in + + + align:start position:0% +the next thing to do is balance them in +terms of energy now they can both be + + align:start position:0% +terms of energy now they can both be + + + align:start position:0% +terms of energy now they can both be +balanced in terms of energy because you + + align:start position:0% +balanced in terms of energy because you + + + align:start position:0% +balanced in terms of energy because you +could attribute the change in the amount + + align:start position:0% +could attribute the change in the amount + + + align:start position:0% +could attribute the change in the amount +of mass from here to there and attribute + + align:start position:0% +of mass from here to there and attribute + + + align:start position:0% +of mass from here to there and attribute +that to the energy of the photon that's + + align:start position:0% +that to the energy of the photon that's + + + align:start position:0% +that to the energy of the photon that's +when you'd have to have a photon of + + align:start position:0% +when you'd have to have a photon of + + + align:start position:0% +when you'd have to have a photon of +energy around fifty MeV but if a proton + + align:start position:0% +energy around fifty MeV but if a proton + + + align:start position:0% +energy around fifty MeV but if a proton +I'm sorry a photon of energy around + + align:start position:0% +I'm sorry a photon of energy around + + + align:start position:0% +I'm sorry a photon of energy around +fifty MeV can't explain what we saw + + align:start position:0% +fifty MeV can't explain what we saw + + + align:start position:0% +fifty MeV can't explain what we saw +instead if there is something like a + + align:start position:0% +instead if there is something like a + + + align:start position:0% +instead if there is something like a +neutron which also has its own rest mass + + align:start position:0% +neutron which also has its own rest mass + + + align:start position:0% +neutron which also has its own rest mass +and its own kinetic energy and that + + align:start position:0% +and its own kinetic energy and that + + + align:start position:0% +and its own kinetic energy and that +neutron were highly penetrating it could + + align:start position:0% +neutron were highly penetrating it could + + + align:start position:0% +neutron were highly penetrating it could +explain what Chadwick saw and so the the + + align:start position:0% +explain what Chadwick saw and so the the + + + align:start position:0% +explain what Chadwick saw and so the the +masses and things of these nuclei were + + align:start position:0% +masses and things of these nuclei were + + + align:start position:0% +masses and things of these nuclei were +fairly well known back then - well six + + align:start position:0% +fairly well known back then - well six + + + align:start position:0% +fairly well known back then - well six +significant digits based on some very + + align:start position:0% +significant digits based on some very + + + align:start position:0% +significant digits based on some very +careful experimentation and all he did + + align:start position:0% +careful experimentation and all he did + + + align:start position:0% +careful experimentation and all he did +is say alright let's take all of the + + align:start position:0% +is say alright let's take all of the + + + align:start position:0% +is say alright let's take all of the +energies in this reaction remember how I + + align:start position:0% +energies in this reaction remember how I + + + align:start position:0% +energies in this reaction remember how I +told you over here you can write any + + align:start position:0% +told you over here you can write any + + + align:start position:0% +told you over here you can write any +nuclear reaction in terms of its kinetic + + align:start position:0% +nuclear reaction in terms of its kinetic + + + align:start position:0% +nuclear reaction in terms of its kinetic +energies and the difference will give + + align:start position:0% +energies and the difference will give + + + align:start position:0% +energies and the difference will give +you the Q value which you can attribute + + align:start position:0% +you the Q value which you can attribute + + + align:start position:0% +you the Q value which you can attribute +to the conversion of mass to energy + + align:start position:0% +to the conversion of mass to energy + + + align:start position:0% +to the conversion of mass to energy +that's what Chadwick did right here he + + align:start position:0% +that's what Chadwick did right here he + + + align:start position:0% +that's what Chadwick did right here he +took the full reaction saying here's the + + align:start position:0% +took the full reaction saying here's the + + + align:start position:0% +took the full reaction saying here's the +mass of beryllium the mass of the alpha + + align:start position:0% +mass of beryllium the mass of the alpha + + + align:start position:0% +mass of beryllium the mass of the alpha +particle the kinetic energy of the alpha + + align:start position:0% +particle the kinetic energy of the alpha + + + align:start position:0% +particle the kinetic energy of the alpha +particle note that he assumed that the + + align:start position:0% +particle note that he assumed that the + + + align:start position:0% +particle note that he assumed that the +kinetic energy of beryllium was zero it + + align:start position:0% +kinetic energy of beryllium was zero it + + + align:start position:0% +kinetic energy of beryllium was zero it +was just sitting at room temperature + + align:start position:0% +was just sitting at room temperature + + + align:start position:0% +was just sitting at room temperature +does anyone know the approximate kinetic + + align:start position:0% +does anyone know the approximate kinetic + + + align:start position:0% +does anyone know the approximate kinetic +energy of atoms at room temperature + + align:start position:0% +energy of atoms at room temperature + + + align:start position:0% +energy of atoms at room temperature +order a magnitude even it's around a + + align:start position:0% +order a magnitude even it's around a + + + align:start position:0% +order a magnitude even it's around a +hundred to a thousandth of an Eevee or + + align:start position:0% +hundred to a thousandth of an Eevee or + + + align:start position:0% +hundred to a thousandth of an Eevee or +an electron volt so when we're talking + + align:start position:0% +an electron volt so when we're talking + + + align:start position:0% +an electron volt so when we're talking +about beryllium whose kinetic energy + + align:start position:0% +about beryllium whose kinetic energy + + + align:start position:0% +about beryllium whose kinetic energy +will say is around 0.01 evie and the + + align:start position:0% +will say is around 0.01 evie and the + + + align:start position:0% +will say is around 0.01 evie and the +alpha particle whose kinetic energy was + + align:start position:0% +alpha particle whose kinetic energy was + + + align:start position:0% +alpha particle whose kinetic energy was +around four times 10 to the 6 + + align:start position:0% +around four times 10 to the 6 + + + align:start position:0% +around four times 10 to the 6 +evie you can see why it's neglected and + + align:start position:0% +evie you can see why it's neglected and + + + align:start position:0% +evie you can see why it's neglected and +you can do that too + + align:start position:0% +you can do that too + + + align:start position:0% +you can do that too +you do not have to account for the + + align:start position:0% +you do not have to account for the + + + align:start position:0% +you do not have to account for the +initial kinetic energy of a nucleus at + + align:start position:0% +initial kinetic energy of a nucleus at + + + align:start position:0% +initial kinetic energy of a nucleus at +rest this is the first aprox + + align:start position:0% +rest this is the first aprox + + + align:start position:0% +rest this is the first aprox +nation that we tend to make to the Q + + align:start position:0% +nation that we tend to make to the Q + + + align:start position:0% +nation that we tend to make to the Q +equation to just have fewer variables + + align:start position:0% +equation to just have fewer variables + + + align:start position:0% +equation to just have fewer variables +and don't worry if you don't remember + + align:start position:0% +and don't worry if you don't remember + + + align:start position:0% +and don't worry if you don't remember +this now because we have a whole lecture + + align:start position:0% +this now because we have a whole lecture + + + align:start position:0% +this now because we have a whole lecture +on the Q equation and so finally he said + + align:start position:0% +on the Q equation and so finally he said + + + align:start position:0% +on the Q equation and so finally he said +all right we'll subtract all the masses + + align:start position:0% +all right we'll subtract all the masses + + + align:start position:0% +all right we'll subtract all the masses +were left with the kinetic energies and + + align:start position:0% +were left with the kinetic energies and + + + align:start position:0% +were left with the kinetic energies and +a little bit of excess rest mass that's + + align:start position:0% +a little bit of excess rest mass that's + + + align:start position:0% +a little bit of excess rest mass that's +got to be this has got to exist and so + + align:start position:0% +got to be this has got to exist and so + + + align:start position:0% +got to be this has got to exist and so +this inequality has to be satisfied + + align:start position:0% +this inequality has to be satisfied + + + align:start position:0% +this inequality has to be satisfied +which indeed it was using this + + align:start position:0% +which indeed it was using this + + + align:start position:0% +which indeed it was using this +inequality he said that the velocity of + + align:start position:0% +inequality he said that the velocity of + + + align:start position:0% +inequality he said that the velocity of +the neutron has to be less than its + + align:start position:0% +the neutron has to be less than its + + + align:start position:0% +the neutron has to be less than its +kinetic energy if it had all of that + + align:start position:0% +kinetic energy if it had all of that + + + align:start position:0% +kinetic energy if it had all of that +energy 3.9 times 10 to the 9 centimeter + + align:start position:0% +energy 3.9 times 10 to the 9 centimeter + + + align:start position:0% +energy 3.9 times 10 to the 9 centimeter +per second indeed it was lower not by + + align:start position:0% +per second indeed it was lower not by + + + align:start position:0% +per second indeed it was lower not by +that much but it still satisfied this + + align:start position:0% +that much but it still satisfied this + + + align:start position:0% +that much but it still satisfied this +criterion so things are checking out + + align:start position:0% +criterion so things are checking out + + + align:start position:0% +criterion so things are checking out +that's pretty cool he looked at another + + align:start position:0% +that's pretty cool he looked at another + + + align:start position:0% +that's pretty cool he looked at another +nuclear reaction that was known at the + + align:start position:0% +nuclear reaction that was known at the + + + align:start position:0% +nuclear reaction that was known at the +time if you were to bombard boron 11 + + align:start position:0% +time if you were to bombard boron 11 + + + align:start position:0% +time if you were to bombard boron 11 +with helium you end up with nitrogen 14 + + align:start position:0% +with helium you end up with nitrogen 14 + + + align:start position:0% +with helium you end up with nitrogen 14 +and either well either end up with + + align:start position:0% +and either well either end up with + + + align:start position:0% +and either well either end up with +nitrogen 15 and a photon or nitrogen 14 + + align:start position:0% +nitrogen 15 and a photon or nitrogen 14 + + + align:start position:0% +nitrogen 15 and a photon or nitrogen 14 +and a neutron explaining another + + align:start position:0% +and a neutron explaining another + + + align:start position:0% +and a neutron explaining another +reaction that wasn't as well known + + align:start position:0% +reaction that wasn't as well known + + + align:start position:0% +reaction that wasn't as well known +before so I'd like to write this nuclear + + align:start position:0% +before so I'd like to write this nuclear + + + align:start position:0% +before so I'd like to write this nuclear +reaction because I want you all to get + + align:start position:0% +reaction because I want you all to get + + + align:start position:0% +reaction because I want you all to get +very familiar with writing nuclear + + align:start position:0% +very familiar with writing nuclear + + + align:start position:0% +very familiar with writing nuclear +reactions let's say boron 11 plus an + + align:start position:0% +reactions let's say boron 11 plus an + + + align:start position:0% +reactions let's say boron 11 plus an +alpha particle will say it has a mass of + + align:start position:0% +alpha particle will say it has a mass of + + + align:start position:0% +alpha particle will say it has a mass of +four becomes neutrons or so nitrogen 14 + + align:start position:0% +four becomes neutrons or so nitrogen 14 + + + align:start position:0% +four becomes neutrons or so nitrogen 14 +and a neutron we also have a shorthand + + align:start position:0% +and a neutron we also have a shorthand + + + align:start position:0% +and a neutron we also have a shorthand +of writing this nuclear reaction which + + align:start position:0% +of writing this nuclear reaction which + + + align:start position:0% +of writing this nuclear reaction which +I'll use on the board for speeds sake + + align:start position:0% +I'll use on the board for speeds sake + + + align:start position:0% +I'll use on the board for speeds sake +usually if you put the initial nucleus + + align:start position:0% +usually if you put the initial nucleus + + + align:start position:0% +usually if you put the initial nucleus +and the initial incoming radiation comma + + align:start position:0% +and the initial incoming radiation comma + + + align:start position:0% +and the initial incoming radiation comma +the exiting radiation and the final + + align:start position:0% +the exiting radiation and the final + + + align:start position:0% +the exiting radiation and the final +nucleus these two right here are + + align:start position:0% +nucleus these two right here are + + + align:start position:0% +nucleus these two right here are +equivalent this is just a shorthand for + + align:start position:0% +equivalent this is just a shorthand for + + + align:start position:0% +equivalent this is just a shorthand for +nuclear reactions this is what you'll + + align:start position:0% +nuclear reactions this is what you'll + + + align:start position:0% +nuclear reactions this is what you'll +tend to see because it's a lot easier to + + align:start position:0% +tend to see because it's a lot easier to + + + align:start position:0% +tend to see because it's a lot easier to +write this shorthand and parse it + + align:start position:0% +write this shorthand and parse it + + + align:start position:0% +write this shorthand and parse it +visually than it is to parse a whole + + align:start position:0% +visually than it is to parse a whole + + + align:start position:0% +visually than it is to parse a whole +nuclear reaction so I just want you to + + align:start position:0% +nuclear reaction so I just want you to + + + align:start position:0% +nuclear reaction so I just want you to +know if you don't know what these are + + align:start position:0% +know if you don't know what these are + + + align:start position:0% +know if you don't know what these are +just remember to stick the arrow here + + align:start position:0% +just remember to stick the arrow here + + + align:start position:0% +just remember to stick the arrow here +stick plus signs and for the parentheses + + align:start position:0% +stick plus signs and for the parentheses + + + align:start position:0% +stick plus signs and for the parentheses +and you've got the same thing and using + + align:start position:0% +and you've got the same thing and using + + + align:start position:0% +and you've got the same thing and using +these you should be able to very quickly + + align:start position:0% +these you should be able to very quickly + + + align:start position:0% +these you should be able to very quickly +determine + + align:start position:0% +determine + + + align:start position:0% +determine +is this reaction balanced what's + + align:start position:0% +is this reaction balanced what's + + + align:start position:0% +is this reaction balanced what's +actually going on and there will be + + align:start position:0% +actually going on and there will be + + + align:start position:0% +actually going on and there will be +tabulated values of Q values or energy + + align:start position:0% +tabulated values of Q values or energy + + + align:start position:0% +tabulated values of Q values or energy +amounts for these sorts of reactions and + + align:start position:0% +amounts for these sorts of reactions and + + + align:start position:0% +amounts for these sorts of reactions and +all sorts of tables I'll be showing you + + align:start position:0% +all sorts of tables I'll be showing you + + + align:start position:0% +all sorts of tables I'll be showing you +and so finally he figured out what the + + align:start position:0% +and so finally he figured out what the + + + align:start position:0% +and so finally he figured out what the +energy or the mass defect of the neutron + + align:start position:0% +energy or the mass defect of the neutron + + + align:start position:0% +energy or the mass defect of the neutron +should be does anyone know what a mass + + align:start position:0% +should be does anyone know what a mass + + + align:start position:0% +should be does anyone know what a mass +defect is this is another kind of core + + align:start position:0% +defect is this is another kind of core + + + align:start position:0% +defect is this is another kind of core +concept let's say you were to want to + + align:start position:0% +concept let's say you were to want to + + + align:start position:0% +concept let's say you were to want to +make an atom of helium so you would have + + align:start position:0% +make an atom of helium so you would have + + + align:start position:0% +make an atom of helium so you would have +to take two protons whose masses are + + align:start position:0% +to take two protons whose masses are + + + align:start position:0% +to take two protons whose masses are +very well known and two neutrons and + + align:start position:0% +very well known and two neutrons and + + + align:start position:0% +very well known and two neutrons and +bring them together so if you were to + + align:start position:0% +bring them together so if you were to + + + align:start position:0% +bring them together so if you were to +have let's say the initial mass would be + + align:start position:0% +have let's say the initial mass would be + + + align:start position:0% +have let's say the initial mass would be +two times the mass of a neutron plus two + + align:start position:0% +two times the mass of a neutron plus two + + + align:start position:0% +two times the mass of a neutron plus two +times the mass of a proton and the final + + align:start position:0% +times the mass of a proton and the final + + + align:start position:0% +times the mass of a proton and the final +mass is just the mass of a helium + + align:start position:0% +mass is just the mass of a helium + + + align:start position:0% +mass is just the mass of a helium +nucleus you'll actually find that the + + align:start position:0% +nucleus you'll actually find that the + + + align:start position:0% +nucleus you'll actually find that the +initial mass does not equal the final + + align:start position:0% +initial mass does not equal the final + + + align:start position:0% +initial mass does not equal the final +mass in bringing nuclei or nucleons + + align:start position:0% +mass in bringing nuclei or nucleons + + + align:start position:0% +mass in bringing nuclei or nucleons +together they actually release what's + + align:start position:0% +together they actually release what's + + + align:start position:0% +together they actually release what's +called their binding energy it's what + + align:start position:0% +called their binding energy it's what + + + align:start position:0% +called their binding energy it's what +keeps the nucleus bound together there's + + align:start position:0% +keeps the nucleus bound together there's + + + align:start position:0% +keeps the nucleus bound together there's +a little bit of mass turned into energy + + align:start position:0% +a little bit of mass turned into energy + + + align:start position:0% +a little bit of mass turned into energy +and so you know how we like to say the + + align:start position:0% +and so you know how we like to say the + + + align:start position:0% +and so you know how we like to say the +hole is usually more than the sum of its + + align:start position:0% +hole is usually more than the sum of its + + + align:start position:0% +hole is usually more than the sum of its +parts + + align:start position:0% +parts + + + align:start position:0% +parts +in nuclear engineering the hole is a + + align:start position:0% +in nuclear engineering the hole is a + + + align:start position:0% +in nuclear engineering the hole is a +little less than the sum of its parts + + align:start position:0% +little less than the sum of its parts + + + align:start position:0% +little less than the sum of its parts +definitely is not equal and Chadwick was + + align:start position:0% +definitely is not equal and Chadwick was + + + align:start position:0% +definitely is not equal and Chadwick was +proposing that a neutron should actually + + align:start position:0% +proposing that a neutron should actually + + + align:start position:0% +proposing that a neutron should actually +be made up of a proton and an electron + + align:start position:0% +be made up of a proton and an electron + + + align:start position:0% +be made up of a proton and an electron +in very close proximity and since the + + align:start position:0% +in very close proximity and since the + + + align:start position:0% +in very close proximity and since the +masses of the proton and the electron + + align:start position:0% +masses of the proton and the electron + + + align:start position:0% +masses of the proton and the electron +were known he said well if we bring the + + align:start position:0% +were known he said well if we bring the + + + align:start position:0% +were known he said well if we bring the +proton and electron very close together + + align:start position:0% +proton and electron very close together + + + align:start position:0% +proton and electron very close together +to have an overall neutral neutron + + align:start position:0% +to have an overall neutral neutron + + + align:start position:0% +to have an overall neutral neutron +particle it should have roughly that + + align:start position:0% +particle it should have roughly that + + + align:start position:0% +particle it should have roughly that +mass defect or that difference between + + align:start position:0% +mass defect or that difference between + + + align:start position:0% +mass defect or that difference between +the energy of its constituent nucleons + + align:start position:0% +the energy of its constituent nucleons + + + align:start position:0% +the energy of its constituent nucleons +and the energy of the assembled nucleus + + align:start position:0% + + + + align:start position:0% + +and you'll hear the words mass defect + + align:start position:0% +and you'll hear the words mass defect + + + align:start position:0% +and you'll hear the words mass defect +and binding energy used mass defect is + + align:start position:0% +and binding energy used mass defect is + + + align:start position:0% +and binding energy used mass defect is +in terms of mass in either you can give + + align:start position:0% +in terms of mass in either you can give + + + align:start position:0% +in terms of mass in either you can give +it in kilograms or in atomic mass units + + align:start position:0% +it in kilograms or in atomic mass units + + + align:start position:0% +it in kilograms or in atomic mass units +or amu or in let's say MeV C squared and + + align:start position:0% +or amu or in let's say MeV C squared and + + + align:start position:0% +or amu or in let's say MeV C squared and +you'll also hear the binding energy just + + align:start position:0% +you'll also hear the binding energy just + + + align:start position:0% +you'll also hear the binding energy just +given in things like MeV I want to show + + align:start position:0% +given in things like MeV I want to show + + + align:start position:0% +given in things like MeV I want to show +you where you can find these things now + + align:start position:0% +you where you can find these things now + + + align:start position:0% +you where you can find these things now +we'll give you the single most useful + + align:start position:0% +we'll give you the single most useful + + + align:start position:0% +we'll give you the single most useful +website that you'll be referring to and + + align:start position:0% +website that you'll be referring to and + + + align:start position:0% +website that you'll be referring to and +I've posted it up on the learning module + + align:start position:0% +I've posted it up on the learning module + + + align:start position:0% +I've posted it up on the learning module +site so now is a good time for me to + + align:start position:0% +site so now is a good time for me to + + + align:start position:0% +site so now is a good time for me to +show you that the site exists and let me + + align:start position:0% +show you that the site exists and let me + + + align:start position:0% +show you that the site exists and let me +just clone my screen real quick so + + align:start position:0% +just clone my screen real quick so + + + align:start position:0% +just clone my screen real quick so +wireless hdmi thing so it takes a sec to + + align:start position:0% +wireless hdmi thing so it takes a sec to + + + align:start position:0% +wireless hdmi thing so it takes a sec to +pop back up + + align:start position:0% + + + + align:start position:0% + +great has anyone not been to this site + + align:start position:0% +great has anyone not been to this site + + + align:start position:0% +great has anyone not been to this site +yet it's okay it's you don't have to be + + align:start position:0% +yet it's okay it's you don't have to be + + + align:start position:0% +yet it's okay it's you don't have to be +embarrassed okay about half of you so I + + align:start position:0% +embarrassed okay about half of you so I + + + align:start position:0% +embarrassed okay about half of you so I +recommend tonight that you start looking + + align:start position:0% +recommend tonight that you start looking + + + align:start position:0% +recommend tonight that you start looking +through this site one make sure that you + + align:start position:0% +through this site one make sure that you + + + align:start position:0% +through this site one make sure that you +can log in because you'll need to log in + + align:start position:0% +can log in because you'll need to log in + + + align:start position:0% +can log in because you'll need to log in +to see some of the copyrighted materials + + align:start position:0% +to see some of the copyrighted materials + + + align:start position:0% +to see some of the copyrighted materials +that I've posted and two because this is + + align:start position:0% +that I've posted and two because this is + + + align:start position:0% +that I've posted and two because this is +where you'll be posting all your + + align:start position:0% +where you'll be posting all your + + + align:start position:0% +where you'll be posting all your +homeworks getting the assignments + + align:start position:0% +homeworks getting the assignments + + + align:start position:0% +homeworks getting the assignments +checking due dates especially if I + + align:start position:0% +checking due dates especially if I + + + align:start position:0% +checking due dates especially if I +postpone a problem set I'll put on an + + align:start position:0% +postpone a problem set I'll put on an + + + align:start position:0% +postpone a problem set I'll put on an +announcement and post it here so you + + align:start position:0% +announcement and post it here so you + + + align:start position:0% +announcement and post it here so you +guys this is like the place to look for + + align:start position:0% +guys this is like the place to look for + + + align:start position:0% +guys this is like the place to look for +everything and in addition I've posted a + + align:start position:0% +everything and in addition I've posted a + + + align:start position:0% +everything and in addition I've posted a +lot of useful materials for you guys + + align:start position:0% +lot of useful materials for you guys + + + align:start position:0% +lot of useful materials for you guys +they're all at the bottom and the top + + align:start position:0% +they're all at the bottom and the top + + + align:start position:0% +they're all at the bottom and the top +one is the Kairi table of nuclides + + align:start position:0% +one is the Kairi table of nuclides + + + align:start position:0% +one is the Kairi table of nuclides +anyone's seen this kind of thing before + + align:start position:0% +anyone's seen this kind of thing before + + + align:start position:0% +anyone's seen this kind of thing before +we have posters of it down on all the + + align:start position:0% +we have posters of it down on all the + + + align:start position:0% +we have posters of it down on all the +first floor classrooms in building 24 + + align:start position:0% +first floor classrooms in building 24 + + + align:start position:0% +first floor classrooms in building 24 +this is our go-to chart when you want to + + align:start position:0% +this is our go-to chart when you want to + + + align:start position:0% +this is our go-to chart when you want to +find out all of the nuclear half-life + + align:start position:0% +find out all of the nuclear half-life + + + align:start position:0% +find out all of the nuclear half-life +radioactive decay and decay of energy + + align:start position:0% +radioactive decay and decay of energy + + + align:start position:0% +radioactive decay and decay of energy +probability of certain interaction + + align:start position:0% +probability of certain interaction + + + align:start position:0% +probability of certain interaction +whatever this is where you go so let's + + align:start position:0% +whatever this is where you go so let's + + + align:start position:0% +whatever this is where you go so let's +take a look at well helium 4 since we've + + align:start position:0% +take a look at well helium 4 since we've + + + align:start position:0% +take a look at well helium 4 since we've +been talking about it better known as an + + align:start position:0% +been talking about it better known as an + + + align:start position:0% +been talking about it better known as an +alpha particle and you'll notice a few + + align:start position:0% +alpha particle and you'll notice a few + + + align:start position:0% +alpha particle and you'll notice a few +different quantities visible the atomic + + align:start position:0% +different quantities visible the atomic + + + align:start position:0% +different quantities visible the atomic +mass 4.00 to 603 to AMU and this is + + align:start position:0% +mass 4.00 to 603 to AMU and this is + + + align:start position:0% +mass 4.00 to 603 to AMU and this is +another tip I want to give you guys + + align:start position:0% +another tip I want to give you guys + + + align:start position:0% +another tip I want to give you guys +right now don't round these numbers + + align:start position:0% +right now don't round these numbers + + + align:start position:0% +right now don't round these numbers +that's one of the major trip up points + + align:start position:0% +that's one of the major trip up points + + + align:start position:0% +that's one of the major trip up points +if you say that's approximately four or + + align:start position:0% +if you say that's approximately four or + + + align:start position:0% +if you say that's approximately four or +4.00 three you probably won't get the + + align:start position:0% +4.00 three you probably won't get the + + + align:start position:0% +4.00 three you probably won't get the +pset questions right because a + + align:start position:0% +pset questions right because a + + + align:start position:0% +pset questions right because a +thousandth of an a.m. you can still + + align:start position:0% +thousandth of an a.m. you can still + + + align:start position:0% +thousandth of an a.m. you can still +represent almost an MeV of lost energy + + align:start position:0% +represent almost an MeV of lost energy + + + align:start position:0% +represent almost an MeV of lost energy +so let's say you have a nuclear reaction + + align:start position:0% +so let's say you have a nuclear reaction + + + align:start position:0% +so let's say you have a nuclear reaction +that liberates a one mega electron volt + + align:start position:0% +that liberates a one mega electron volt + + + align:start position:0% +that liberates a one mega electron volt +or one MeV gamma-ray and you get the + + align:start position:0% +or one MeV gamma-ray and you get the + + + align:start position:0% +or one MeV gamma-ray and you get the +fourth digit wrong in one of your mass + + align:start position:0% +fourth digit wrong in one of your mass + + + align:start position:0% +fourth digit wrong in one of your mass +calculations it's like that gamma ray + + align:start position:0% +calculations it's like that gamma ray + + + align:start position:0% +calculations it's like that gamma ray +didn't exist and you won't get the + + align:start position:0% +didn't exist and you won't get the + + + align:start position:0% +didn't exist and you won't get the +answer right so again the word to the + + align:start position:0% +answer right so again the word to the + + + align:start position:0% +answer right so again the word to the +wise do not round you'll also see what's + + align:start position:0% +wise do not round you'll also see what's + + + align:start position:0% +wise do not round you'll also see what's +known as the excess mass or the binding + + align:start position:0% +known as the excess mass or the binding + + + align:start position:0% +known as the excess mass or the binding +energy so this binding energy right here + + align:start position:0% +energy so this binding energy right here + + + align:start position:0% +energy so this binding energy right here +if you were to take two protons and two + + align:start position:0% +if you were to take two protons and two + + + align:start position:0% +if you were to take two protons and two +neutrons and bring them together and + + align:start position:0% +neutrons and bring them together and + + + align:start position:0% +neutrons and bring them together and +look at the difference in masses from + + align:start position:0% +look at the difference in masses from + + + align:start position:0% +look at the difference in masses from +let's say the same old formula as before + + align:start position:0% +let's say the same old formula as before + + + align:start position:0% +let's say the same old formula as before +you would get the difference of twenty + + align:start position:0% +you would get the difference of twenty + + + align:start position:0% +you would get the difference of twenty +eight thousand two hundred ninety-five + + align:start position:0% +eight thousand two hundred ninety-five + + + align:start position:0% +eight thousand two hundred ninety-five +ke V or about about twenty eight point + + align:start position:0% +ke V or about about twenty eight point + + + align:start position:0% +ke V or about about twenty eight point +two nine five 673 MeV again don't round + + align:start position:0% +two nine five 673 MeV again don't round + + + align:start position:0% +two nine five 673 MeV again don't round +let's figure this out right here so we + + align:start position:0% +let's figure this out right here so we + + + align:start position:0% +let's figure this out right here so we +have twenty eight point two nine five + + align:start position:0% +have twenty eight point two nine five + + + align:start position:0% +have twenty eight point two nine five +six seven three MeV and there's a + + align:start position:0% +six seven three MeV and there's a + + + align:start position:0% +six seven three MeV and there's a +conversion factor that you should either + + align:start position:0% +conversion factor that you should either + + + align:start position:0% +conversion factor that you should either +memorize or write down either way it's + + align:start position:0% +memorize or write down either way it's + + + align:start position:0% +memorize or write down either way it's +good it's about nine thirty one point + + align:start position:0% +good it's about nine thirty one point + + + align:start position:0% +good it's about nine thirty one point +four nine MeV per atomic mass unit this + + align:start position:0% +four nine MeV per atomic mass unit this + + + align:start position:0% +four nine MeV per atomic mass unit this +is your mass energy equivalence that + + align:start position:0% +is your mass energy equivalence that + + + align:start position:0% +is your mass energy equivalence that +you'll be using over and over and over + + align:start position:0% +you'll be using over and over and over + + + align:start position:0% +you'll be using over and over and over +again and again don't round those last + + align:start position:0% +again and again don't round those last + + + align:start position:0% +again and again don't round those last +two digits are important so by taking + + align:start position:0% +two digits are important so by taking + + + align:start position:0% +two digits are important so by taking +this energy and dividing by this + + align:start position:0% +this energy and dividing by this + + + align:start position:0% +this energy and dividing by this +conversion factor you can figure out how + + align:start position:0% +conversion factor you can figure out how + + + align:start position:0% +conversion factor you can figure out how +many atomic mass units are lost in terms + + align:start position:0% +many atomic mass units are lost in terms + + + align:start position:0% +many atomic mass units are lost in terms +of actual mass when you assemble an + + align:start position:0% +of actual mass when you assemble an + + + align:start position:0% +of actual mass when you assemble an +alpha particle from its constituent + + align:start position:0% +alpha particle from its constituent + + + align:start position:0% +alpha particle from its constituent +pieces and the rest of the stuff we will + + align:start position:0% +pieces and the rest of the stuff we will + + + align:start position:0% +pieces and the rest of the stuff we will +get into later it's not really relevant + + align:start position:0% +get into later it's not really relevant + + + align:start position:0% +get into later it's not really relevant +to today's discussion but it's + + align:start position:0% +to today's discussion but it's + + + align:start position:0% +to today's discussion but it's +definitely relevant to today's course + + align:start position:0% +definitely relevant to today's course + + + align:start position:0% +definitely relevant to today's course +cool okay and then on to one of the last + + align:start position:0% +cool okay and then on to one of the last + + + align:start position:0% +cool okay and then on to one of the last +things that he mentioned is some + + align:start position:0% +things that he mentioned is some + + + align:start position:0% +things that he mentioned is some +predictions to say okay let's say this + + align:start position:0% +predictions to say okay let's say this + + + align:start position:0% +predictions to say okay let's say this +Neutron exists it doesn't have charged + + align:start position:0% +Neutron exists it doesn't have charged + + + align:start position:0% +Neutron exists it doesn't have charged +most matter interacts with other + + align:start position:0% +most matter interacts with other + + + align:start position:0% +most matter interacts with other +matter by virtue of Coulomb Bacoor + + align:start position:0% +matter by virtue of Coulomb Bacoor + + + align:start position:0% +matter by virtue of Coulomb Bacoor +charge interactions if the neutron has + + align:start position:0% +charge interactions if the neutron has + + + align:start position:0% +charge interactions if the neutron has +no charge it shouldn't really seem + + align:start position:0% +no charge it shouldn't really seem + + + align:start position:0% +no charge it shouldn't really seem +matter except for nuclei and this is + + align:start position:0% +matter except for nuclei and this is + + + align:start position:0% +matter except for nuclei and this is +exactly what he said is the electrical + + align:start position:0% +exactly what he said is the electrical + + + align:start position:0% +exactly what he said is the electrical +field of a neutron will be extremely + + align:start position:0% +field of a neutron will be extremely + + + align:start position:0% +field of a neutron will be extremely +small except at small distances because + + align:start position:0% +small except at small distances because + + + align:start position:0% +small except at small distances because +he proposed that a neutron is a proton + + align:start position:0% +he proposed that a neutron is a proton + + + align:start position:0% +he proposed that a neutron is a proton +plus an electron so once you get to + + align:start position:0% +plus an electron so once you get to + + + align:start position:0% +plus an electron so once you get to +around the radius of the neutron you + + align:start position:0% +around the radius of the neutron you + + + align:start position:0% +around the radius of the neutron you +might start to see some charge but not + + align:start position:0% +might start to see some charge but not + + + align:start position:0% +might start to see some charge but not +before and so most other matter unless + + align:start position:0% +before and so most other matter unless + + + align:start position:0% +before and so most other matter unless +you have a head-on collision with a + + align:start position:0% +you have a head-on collision with a + + + align:start position:0% +you have a head-on collision with a +nucleus neutrons won't see it and that + + align:start position:0% +nucleus neutrons won't see it and that + + + align:start position:0% +nucleus neutrons won't see it and that +helps explain why the neutrons had such + + align:start position:0% +helps explain why the neutrons had such + + + align:start position:0% +helps explain why the neutrons had such +high penetrating power or high range + + align:start position:0% +high penetrating power or high range + + + align:start position:0% +high penetrating power or high range +because they just went streaming through + + align:start position:0% +because they just went streaming through + + + align:start position:0% +because they just went streaming through +most materials invisible to the + + align:start position:0% +most materials invisible to the + + + align:start position:0% +most materials invisible to the +electrons so very forward-thinking and + + align:start position:0% +electrons so very forward-thinking and + + + align:start position:0% +electrons so very forward-thinking and +turned out to be very correct and then + + align:start position:0% +turned out to be very correct and then + + + align:start position:0% +turned out to be very correct and then +finally as a kind of mic drop conclusion + + align:start position:0% +finally as a kind of mic drop conclusion + + + align:start position:0% +finally as a kind of mic drop conclusion +came up with the finalists for the final + + align:start position:0% +came up with the finalists for the final + + + align:start position:0% +came up with the finalists for the final +concluding statements it is okay we know + + align:start position:0% +concluding statements it is okay we know + + + align:start position:0% +concluding statements it is okay we know +there's a neutron we know it's mass the + + align:start position:0% +there's a neutron we know it's mass the + + + align:start position:0% +there's a neutron we know it's mass the +actual mass of the neutron is about + + align:start position:0% +actual mass of the neutron is about + + + align:start position:0% +actual mass of the neutron is about +1.008 7:00 a.m. you so within 0.1% of + + align:start position:0% +1.008 7:00 a.m. you so within 0.1% of + + + align:start position:0% +1.008 7:00 a.m. you so within 0.1% of +Chadwicks calculations and predictions + + align:start position:0% +Chadwicks calculations and predictions + + + align:start position:0% +Chadwicks calculations and predictions +based on 1930s equipment which is + + align:start position:0% +based on 1930s equipment which is + + + align:start position:0% +based on 1930s equipment which is +strikingly awesome + + align:start position:0% +strikingly awesome + + + align:start position:0% +strikingly awesome +and there you have it that's the + + align:start position:0% +and there you have it that's the + + + align:start position:0% +and there you have it that's the +discovery of the neutron using most of + + align:start position:0% +discovery of the neutron using most of + + + align:start position:0% +discovery of the neutron using most of +the concepts that we're going to be + + align:start position:0% +the concepts that we're going to be + + + align:start position:0% +the concepts that we're going to be +teaching you here in 2201 so right now + + align:start position:0% +teaching you here in 2201 so right now + + + align:start position:0% +teaching you here in 2201 so right now +i'd say you're a scientific knowledge if + + align:start position:0% +i'd say you're a scientific knowledge if + + + align:start position:0% +i'd say you're a scientific knowledge if +we don't count what you read on the news + + align:start position:0% +we don't count what you read on the news + + + align:start position:0% +we don't count what you read on the news +it's roughly around 1850 when all the + + align:start position:0% +it's roughly around 1850 when all the + + + align:start position:0% +it's roughly around 1850 when all the +E&M stuff was being figured out we are + + align:start position:0% +E&M stuff was being figured out we are + + + align:start position:0% +E&M stuff was being figured out we are +gonna bring you screaming into the 1930s + + align:start position:0% +gonna bring you screaming into the 1930s + + + align:start position:0% +gonna bring you screaming into the 1930s +and by about month one will hit the + + align:start position:0% +and by about month one will hit the + + + align:start position:0% +and by about month one will hit the +present day when we could start to talk + + align:start position:0% +present day when we could start to talk + + + align:start position:0% +present day when we could start to talk +about the super-heavy elements like the + + align:start position:0% +about the super-heavy elements like the + + + align:start position:0% +about the super-heavy elements like the +ones that were discovered last year I + + align:start position:0% +ones that were discovered last year I + + + align:start position:0% +ones that were discovered last year I +think there was even some this year but + + align:start position:0% +think there was even some this year but + + + align:start position:0% +think there was even some this year but +we'll look at a physics today article + + align:start position:0% +we'll look at a physics today article + + + align:start position:0% +we'll look at a physics today article +from last year get to the point of + + align:start position:0% +from last year get to the point of + + + align:start position:0% +from last year get to the point of +explaining why super-heavy elements + + align:start position:0% +explaining why super-heavy elements + + + align:start position:0% +explaining why super-heavy elements +might be stable why are we even looking + + align:start position:0% +might be stable why are we even looking + + + align:start position:0% +might be stable why are we even looking +for them where do cosmic rays come from + + align:start position:0% +for them where do cosmic rays come from + + + align:start position:0% +for them where do cosmic rays come from +how do we know that they're cosmic rays + + align:start position:0% +how do we know that they're cosmic rays + + + align:start position:0% +how do we know that they're cosmic rays +and not something else how can you tell + + align:start position:0% +and not something else how can you tell + + + align:start position:0% +and not something else how can you tell +a reactor turns on anywhere in the world + + align:start position:0% +a reactor turns on anywhere in the world + + + align:start position:0% +a reactor turns on anywhere in the world +by measuring different bits of radiation + + align:start position:0% +by measuring different bits of radiation + + + align:start position:0% +by measuring different bits of radiation +which is an active defense project that + + align:start position:0% +which is an active defense project that + + + align:start position:0% +which is an active defense project that +folks are pursuing right now lots of + + align:start position:0% +folks are pursuing right now lots of + + + align:start position:0% +folks are pursuing right now lots of +really fun questions and speaking of + + align:start position:0% +really fun questions and speaking of + + + align:start position:0% +really fun questions and speaking of +questions do you guys have any questions + + align:start position:0% +questions do you guys have any questions + + + align:start position:0% +questions do you guys have any questions +about what we've explained here + + align:start position:0% +about what we've explained here + + + align:start position:0% +about what we've explained here +how we've retraced Chadwicks discovery + + align:start position:0% +how we've retraced Chadwicks discovery + + + align:start position:0% +how we've retraced Chadwicks discovery +of the neutron from basic nuclear + + align:start position:0% +of the neutron from basic nuclear + + + align:start position:0% +of the neutron from basic nuclear +science principles so who here's seen + + align:start position:0% +science principles so who here's seen + + + align:start position:0% +science principles so who here's seen +these nuclear reactions before cool this + + align:start position:0% +these nuclear reactions before cool this + + + align:start position:0% +these nuclear reactions before cool this +is something that I hope folks would + + align:start position:0% +is something that I hope folks would + + + align:start position:0% +is something that I hope folks would +cover in high school but with a general + + align:start position:0% +cover in high school but with a general + + + align:start position:0% +cover in high school but with a general +trend of watering down science education + + align:start position:0% +trend of watering down science education + + + align:start position:0% +trend of watering down science education +I didn't want to make any assumptions + + align:start position:0% +I didn't want to make any assumptions + + + align:start position:0% +I didn't want to make any assumptions +I'm glad to hear this was covered was + + align:start position:0% +I'm glad to hear this was covered was + + + align:start position:0% +I'm glad to hear this was covered was +this covered at MIT you guys relying on + + align:start position:0% +this covered at MIT you guys relying on + + + align:start position:0% +this covered at MIT you guys relying on +highschool knowledge okay good not good + + align:start position:0% +highschool knowledge okay good not good + + + align:start position:0% +highschool knowledge okay good not good +but good I know where you are not good + + align:start position:0% +but good I know where you are not good + + + align:start position:0% +but good I know where you are not good +that MIT doesn't teach anything nuclear + + align:start position:0% +that MIT doesn't teach anything nuclear + + + align:start position:0% +that MIT doesn't teach anything nuclear +until year two that's okay you guys + + align:start position:0% +until year two that's okay you guys + + + align:start position:0% +until year two that's okay you guys +along with the physics department will + + align:start position:0% +along with the physics department will + + + align:start position:0% +along with the physics department will +get at least a twentieth century + + align:start position:0% +get at least a twentieth century + + + align:start position:0% +get at least a twentieth century +knowledge of physics and how 21st by the + + align:start position:0% +knowledge of physics and how 21st by the + + + align:start position:0% +knowledge of physics and how 21st by the +at the end of month one so I want to + + align:start position:0% +at the end of month one so I want to + + + align:start position:0% +at the end of month one so I want to +come back to the stellar site and + + align:start position:0% +come back to the stellar site and + + + align:start position:0% +come back to the stellar site and +specifically the syllabus I've taken a + + align:start position:0% +specifically the syllabus I've taken a + + + align:start position:0% +specifically the syllabus I've taken a +lot of care to write a very detailed + + align:start position:0% +lot of care to write a very detailed + + + align:start position:0% +lot of care to write a very detailed +syllabus of what we're going to do what + + align:start position:0% +syllabus of what we're going to do what + + + align:start position:0% +syllabus of what we're going to do what +I expect of you guys what you can expect + + align:start position:0% +I expect of you guys what you can expect + + + align:start position:0% +I expect of you guys what you can expect +of me and what we'll be doing every + + align:start position:0% +of me and what we'll be doing every + + + align:start position:0% +of me and what we'll be doing every +single day so if you want to know what + + align:start position:0% +single day so if you want to know what + + + align:start position:0% +single day so if you want to know what +we're gonna be doing if you have a class + + align:start position:0% +we're gonna be doing if you have a class + + + align:start position:0% +we're gonna be doing if you have a class +that you miss and you want to know what + + align:start position:0% +that you miss and you want to know what + + + align:start position:0% +that you miss and you want to know what +notes you're gonna miss it's all written + + align:start position:0% +notes you're gonna miss it's all written + + + align:start position:0% +notes you're gonna miss it's all written +up here I want to get right into + + align:start position:0% +up here I want to get right into + + + align:start position:0% +up here I want to get right into +assignments because everyone wants to + + align:start position:0% +assignments because everyone wants to + + + align:start position:0% +assignments because everyone wants to +know what am I responsible for oh not + + align:start position:0% +know what am I responsible for oh not + + + align:start position:0% +know what am I responsible for oh not +too much + + align:start position:0% +too much + + + align:start position:0% +too much +nine problem-sets three quizzes the + + align:start position:0% +nine problem-sets three quizzes the + + + align:start position:0% +nine problem-sets three quizzes the +final exam is just a quiz it's only + + align:start position:0% +final exam is just a quiz it's only + + + align:start position:0% +final exam is just a quiz it's only +worth twenty four percent of your grade + + align:start position:0% +worth twenty four percent of your grade + + + align:start position:0% +worth twenty four percent of your grade +instead of twenty to get the math to + + align:start position:0% +instead of twenty to get the math to + + + align:start position:0% +instead of twenty to get the math to +work out because I eliminated one + + align:start position:0% +work out because I eliminated one + + + align:start position:0% +work out because I eliminated one +problem set to avoid running afoul of + + align:start position:0% +problem set to avoid running afoul of + + + align:start position:0% +problem set to avoid running afoul of +MIT regulations about not assigning + + align:start position:0% +MIT regulations about not assigning + + + align:start position:0% +MIT regulations about not assigning +things at the last week of class but + + align:start position:0% +things at the last week of class but + + + align:start position:0% +things at the last week of class but +there are three quizzes so the final + + align:start position:0% +there are three quizzes so the final + + + align:start position:0% +there are three quizzes so the final +exam is just another quiz it's not a + + align:start position:0% +exam is just another quiz it's not a + + + align:start position:0% +exam is just another quiz it's not a +super high stress crazy thing because I + + align:start position:0% +super high stress crazy thing because I + + + align:start position:0% +super high stress crazy thing because I +don't see a point in doing that you can + + align:start position:0% +don't see a point in doing that you can + + + align:start position:0% +don't see a point in doing that you can +make your assignments however you want I + + align:start position:0% +make your assignments however you want I + + + align:start position:0% +make your assignments however you want I +don't care as long as I can read them + + align:start position:0% +don't care as long as I can read them + + + align:start position:0% +don't care as long as I can read them +but I do ask that in the end you submit + + align:start position:0% +but I do ask that in the end you submit + + + align:start position:0% +but I do ask that in the end you submit +a PDF file on the stellar site and the + + align:start position:0% +a PDF file on the stellar site and the + + + align:start position:0% +a PDF file on the stellar site and the +reason for this is my first course that + + align:start position:0% +reason for this is my first course that + + + align:start position:0% +reason for this is my first course that +I ever taught at MIT as a professor or + + align:start position:0% +I ever taught at MIT as a professor or + + + align:start position:0% +I ever taught at MIT as a professor or +the Graduate modules + + align:start position:0% +the Graduate modules + + + align:start position:0% +the Graduate modules +22:13 intro to nuclear systems and 22:14 + + align:start position:0% +22:13 intro to nuclear systems and 22:14 + + + align:start position:0% +22:13 intro to nuclear systems and 22:14 +intro to nuclear materials + + align:start position:0% +intro to nuclear materials + + + align:start position:0% +intro to nuclear materials +I accepted paper submissions and by week + + align:start position:0% +I accepted paper submissions and by week + + + align:start position:0% +I accepted paper submissions and by week +three I had to microwave them because + + align:start position:0% +three I had to microwave them because + + + align:start position:0% +three I had to microwave them because +three or four times I definitely saw + + align:start position:0% +three or four times I definitely saw + + + align:start position:0% +three or four times I definitely saw +blood and there + + align:start position:0% +blood and there + + + align:start position:0% +blood and there +also some weird stains that I didn't + + align:start position:0% +also some weird stains that I didn't + + + align:start position:0% +also some weird stains that I didn't +want to explain so I added they had the + + align:start position:0% +want to explain so I added they had the + + + align:start position:0% +want to explain so I added they had the +habit of unstaple Aang microwaving Andry + + align:start position:0% +habit of unstaple Aang microwaving Andry + + + align:start position:0% +habit of unstaple Aang microwaving Andry +stapling the piece sets before grading + + align:start position:0% +stapling the piece sets before grading + + + align:start position:0% +stapling the piece sets before grading +so the digital world is sterile I'm not + + align:start position:0% +so the digital world is sterile I'm not + + + align:start position:0% +so the digital world is sterile I'm not +a germaphobe I just don't like blood in + + align:start position:0% +a germaphobe I just don't like blood in + + + align:start position:0% +a germaphobe I just don't like blood in +my house especially if it's not mine so + + align:start position:0% +my house especially if it's not mine so + + + align:start position:0% +my house especially if it's not mine so +I ask that you guys submit PDFs on the + + align:start position:0% +I ask that you guys submit PDFs on the + + + align:start position:0% +I ask that you guys submit PDFs on the +stellar site they're due at 5:00 p.m. to + + align:start position:0% +stellar site they're due at 5:00 p.m. to + + + align:start position:0% +stellar site they're due at 5:00 p.m. to +make sure that you're done and you can + + align:start position:0% +make sure that you're done and you can + + + align:start position:0% +make sure that you're done and you can +go home and relax or work on something + + align:start position:0% +go home and relax or work on something + + + align:start position:0% +go home and relax or work on something +else + + align:start position:0% +else + + + align:start position:0% +else +I used to some haps things do at + + align:start position:0% +I used to some haps things do at + + + align:start position:0% +I used to some haps things do at +midnight and I had every submission was + + align:start position:0% +midnight and I had every submission was + + + align:start position:0% +midnight and I had every submission was +11:59 p.m. I'm not gonna do that anymore + + align:start position:0% +11:59 p.m. I'm not gonna do that anymore + + + align:start position:0% +11:59 p.m. I'm not gonna do that anymore +do make sure to submit 15 minutes early + + align:start position:0% +do make sure to submit 15 minutes early + + + align:start position:0% +do make sure to submit 15 minutes early +so if your computer or the stellar site + + align:start position:0% +so if your computer or the stellar site + + + align:start position:0% +so if your computer or the stellar site +has trouble send me an email or a text + + align:start position:0% +has trouble send me an email or a text + + + align:start position:0% +has trouble send me an email or a text +or whatever saying I'm trying to submit + + align:start position:0% +or whatever saying I'm trying to submit + + + align:start position:0% +or whatever saying I'm trying to submit +and it's not working here's a backup or + + align:start position:0% +and it's not working here's a backup or + + + align:start position:0% +and it's not working here's a backup or +I'm leaving something under your door + + align:start position:0% +I'm leaving something under your door + + + align:start position:0% +I'm leaving something under your door +and if you want my cellphone number + + align:start position:0% +and if you want my cellphone number + + + align:start position:0% +and if you want my cellphone number +that's also my office number it's also + + align:start position:0% +that's also my office number it's also + + + align:start position:0% +that's also my office number it's also +my only number it's in the MIT directory + + align:start position:0% +my only number it's in the MIT directory + + + align:start position:0% +my only number it's in the MIT directory +so if there's some the merchants that + + align:start position:0% +so if there's some the merchants that + + + align:start position:0% +so if there's some the merchants that +you need to make me aware of please do + + align:start position:0% +you need to make me aware of please do + + + align:start position:0% +you need to make me aware of please do +communicate I'd rather you tell me then + + align:start position:0% +communicate I'd rather you tell me then + + + align:start position:0% +communicate I'd rather you tell me then +be worried about not telling me and then + + align:start position:0% +be worried about not telling me and then + + + align:start position:0% +be worried about not telling me and then +find out later so we all clear on that + + align:start position:0% +find out later so we all clear on that + + + align:start position:0% +find out later so we all clear on that +cool as far as what the assignments are + + align:start position:0% +cool as far as what the assignments are + + + align:start position:0% +cool as far as what the assignments are +each assignments going to be about 50% + + align:start position:0% +each assignments going to be about 50% + + + align:start position:0% +each assignments going to be about 50% +basic calculations working out things + + align:start position:0% +basic calculations working out things + + + align:start position:0% +basic calculations working out things +like these to make sure you've mastered + + align:start position:0% +like these to make sure you've mastered + + + align:start position:0% +like these to make sure you've mastered +the material that you understand writing + + align:start position:0% +the material that you understand writing + + + align:start position:0% +the material that you understand writing +nuclear reactions you can balance a Q + + align:start position:0% +nuclear reactions you can balance a Q + + + align:start position:0% +nuclear reactions you can balance a Q +equation you can tell me about what your + + align:start position:0% +equation you can tell me about what your + + + align:start position:0% +equation you can tell me about what your +cancer risk would be from a certain dose + + align:start position:0% +cancer risk would be from a certain dose + + + align:start position:0% +cancer risk would be from a certain dose +of material so this is like when you go + + align:start position:0% +of material so this is like when you go + + + align:start position:0% +of material so this is like when you go +out in the real world the sort of + + align:start position:0% +out in the real world the sort of + + + align:start position:0% +out in the real world the sort of +calculations everyone would expect you + + align:start position:0% +calculations everyone would expect you + + + align:start position:0% +calculations everyone would expect you +as a nuclear engineer to be able to do + + align:start position:0% +as a nuclear engineer to be able to do + + + align:start position:0% +as a nuclear engineer to be able to do +and then 50% of each problem set is + + align:start position:0% +and then 50% of each problem set is + + + align:start position:0% +and then 50% of each problem set is +either going to be analytical questions + + align:start position:0% +either going to be analytical questions + + + align:start position:0% +either going to be analytical questions +of considerable difficulty this is MIT + + align:start position:0% +of considerable difficulty this is MIT + + + align:start position:0% +of considerable difficulty this is MIT +or not just here to give you the basics + + align:start position:0% +or not just here to give you the basics + + + align:start position:0% +or not just here to give you the basics +so that you can regurgitate a textbook + + align:start position:0% +so that you can regurgitate a textbook + + + align:start position:0% +so that you can regurgitate a textbook +on to the first person who asks we're + + align:start position:0% +on to the first person who asks we're + + + align:start position:0% +on to the first person who asks we're +here to make sure that you can go + + align:start position:0% +here to make sure that you can go + + + align:start position:0% +here to make sure that you can go +farther because you guys are the future + + align:start position:0% +farther because you guys are the future + + + align:start position:0% +farther because you guys are the future +of this very small and diminishing field + + align:start position:0% +of this very small and diminishing field + + + align:start position:0% +of this very small and diminishing field +at the moment if you look at the nuclear + + align:start position:0% +at the moment if you look at the nuclear + + + align:start position:0% +at the moment if you look at the nuclear +power in the u.s. I would say growing in + + align:start position:0% +power in the u.s. I would say growing in + + + align:start position:0% +power in the u.s. I would say growing in +terms of the world but not in terms of + + align:start position:0% +terms of the world but not in terms of + + + align:start position:0% +terms of the world but not in terms of +the US and you guys are going to be in + + align:start position:0% +the US and you guys are going to be in + + + align:start position:0% +the US and you guys are going to be in +charge of leading this field and + + align:start position:0% +charge of leading this field and + + + align:start position:0% +charge of leading this field and +determining where it's going to go so + + align:start position:0% +determining where it's going to go so + + + align:start position:0% +determining where it's going to go so +you've got to be up at the cutting edge + + align:start position:0% +you've got to be up at the cutting edge + + + align:start position:0% +you've got to be up at the cutting edge +and we're going to take you to the edge + + align:start position:0% +and we're going to take you to the edge + + + align:start position:0% +and we're going to take you to the edge +of your abilities my favorite kind of + + align:start position:0% +of your abilities my favorite kind of + + + align:start position:0% +of your abilities my favorite kind of +problems to give one sentence for the + + align:start position:0% +problems to give one sentence for the + + + align:start position:0% +problems to give one sentence for the +question 5 or 10 pages for the answer if + + align:start position:0% +question 5 or 10 pages for the answer if + + + align:start position:0% +question 5 or 10 pages for the answer if +you don't get the trick now that's okay + + align:start position:0% +you don't get the trick now that's okay + + + align:start position:0% +you don't get the trick now that's okay +it's perfectly it's + + align:start position:0% +it's perfectly it's + + + align:start position:0% +it's perfectly it's +perfectly fine not to figure out the + + align:start position:0% +perfectly fine not to figure out the + + + align:start position:0% +perfectly fine not to figure out the +answer in the end in fact I'll usually + + align:start position:0% +answer in the end in fact I'll usually + + + align:start position:0% +answer in the end in fact I'll usually +give you the answer for the analytical + + align:start position:0% +give you the answer for the analytical + + + align:start position:0% +give you the answer for the analytical +questions because I want to see your + + align:start position:0% +questions because I want to see your + + + align:start position:0% +questions because I want to see your +approach I'm not interested in you + + align:start position:0% +approach I'm not interested in you + + + align:start position:0% +approach I'm not interested in you +nailing the answer I'm interested in + + align:start position:0% +nailing the answer I'm interested in + + + align:start position:0% +nailing the answer I'm interested in +seeing how you think and copious partial + + align:start position:0% +seeing how you think and copious partial + + + align:start position:0% +seeing how you think and copious partial +credit will be given for the one you + + align:start position:0% +credit will be given for the one you + + + align:start position:0% +credit will be given for the one you +think so if you have a missing step and + + align:start position:0% +think so if you have a missing step and + + + align:start position:0% +think so if you have a missing step and +you say I don't know this step I'm going + + align:start position:0% +you say I don't know this step I'm going + + + align:start position:0% +you say I don't know this step I'm going +to assume variable a and keep going you + + align:start position:0% +to assume variable a and keep going you + + + align:start position:0% +to assume variable a and keep going you +will get credit for the subsequent steps + + align:start position:0% +will get credit for the subsequent steps + + + align:start position:0% +will get credit for the subsequent steps +I want to see how you think from start + + align:start position:0% +I want to see how you think from start + + + align:start position:0% +I want to see how you think from start +to finish and how you cover for holes + + align:start position:0% +to finish and how you cover for holes + + + align:start position:0% +to finish and how you cover for holes +that you can't get through so everyone + + align:start position:0% +that you can't get through so everyone + + + align:start position:0% +that you can't get through so everyone +clear on that partial credit yes use it + + align:start position:0% +clear on that partial credit yes use it + + + align:start position:0% +clear on that partial credit yes use it +to your fullest ability the other half + + align:start position:0% +to your fullest ability the other half + + + align:start position:0% +to your fullest ability the other half +of the problem sets will have take-home + + align:start position:0% +of the problem sets will have take-home + + + align:start position:0% +of the problem sets will have take-home +laboratory assignments it's not just + + align:start position:0% +laboratory assignments it's not just + + + align:start position:0% +laboratory assignments it's not just +enough for me to tell you about nuclear + + align:start position:0% +enough for me to tell you about nuclear + + + align:start position:0% +enough for me to tell you about nuclear +engineering you have to see it for + + align:start position:0% +engineering you have to see it for + + + align:start position:0% +engineering you have to see it for +yourself and you have to feel it for + + align:start position:0% +yourself and you have to feel it for + + + align:start position:0% +yourself and you have to feel it for +yourself and once in a while you'll get + + align:start position:0% +yourself and once in a while you'll get + + + align:start position:0% +yourself and once in a while you'll get +a mild electric shock by yourself if + + align:start position:0% +a mild electric shock by yourself if + + + align:start position:0% +a mild electric shock by yourself if +things go wrong but that's ok it happens + + align:start position:0% +things go wrong but that's ok it happens + + + align:start position:0% +things go wrong but that's ok it happens +to the best of us I got zapped by our + + align:start position:0% +to the best of us I got zapped by our + + + align:start position:0% +to the best of us I got zapped by our +you guys have all made Geiger counters + + align:start position:0% +you guys have all made Geiger counters + + + align:start position:0% +you guys have all made Geiger counters +right does anyone not made a Geiger + + align:start position:0% +right does anyone not made a Geiger + + + align:start position:0% +right does anyone not made a Geiger +counter yet oho ok it sounds like we + + align:start position:0% +counter yet oho ok it sounds like we + + + align:start position:0% +counter yet oho ok it sounds like we +need to run another workshop well our + + align:start position:0% +need to run another workshop well our + + + align:start position:0% +need to run another workshop well our +Geiger counters rely on a neat little + + align:start position:0% +Geiger counters rely on a neat little + + + align:start position:0% +Geiger counters rely on a neat little +boost converter power supply that takes + + align:start position:0% +boost converter power supply that takes + + + align:start position:0% +boost converter power supply that takes +9 volts and steps it up to 400 volts via + + align:start position:0% +9 volts and steps it up to 400 volts via + + + align:start position:0% +9 volts and steps it up to 400 volts via +some switching things that means you + + align:start position:0% +some switching things that means you + + + align:start position:0% +some switching things that means you +have 400 volts on a big metal tube and + + align:start position:0% +have 400 volts on a big metal tube and + + + align:start position:0% +have 400 volts on a big metal tube and +if you're working on your circuit and + + align:start position:0% +if you're working on your circuit and + + + align:start position:0% +if you're working on your circuit and +happen to brush against it you get zero + + align:start position:0% +happen to brush against it you get zero + + + align:start position:0% +happen to brush against it you get zero +current so it doesn't hurt you in the + + align:start position:0% +current so it doesn't hurt you in the + + + align:start position:0% +current so it doesn't hurt you in the +medical sense but it hurts I also have a + + align:start position:0% +medical sense but it hurts I also have a + + + align:start position:0% +medical sense but it hurts I also have a +dance I call the 60 Hertz shuffle it's + + align:start position:0% +dance I call the 60 Hertz shuffle it's + + + align:start position:0% +dance I call the 60 Hertz shuffle it's +the high speed shaking that you do when + + align:start position:0% +the high speed shaking that you do when + + + align:start position:0% +the high speed shaking that you do when +you're connected to 60 Hertz somewhere + + align:start position:0% +you're connected to 60 Hertz somewhere + + + align:start position:0% +you're connected to 60 Hertz somewhere +from the wall outlet none of you guys + + align:start position:0% +from the wall outlet none of you guys + + + align:start position:0% +from the wall outlet none of you guys +will be exposed to this but done it + + align:start position:0% +will be exposed to this but done it + + + align:start position:0% +will be exposed to this but done it +enough times that I have a name for the + + align:start position:0% +enough times that I have a name for the + + + align:start position:0% +enough times that I have a name for the +dance if you get 400 volts you'll just + + align:start position:0% +dance if you get 400 volts you'll just + + + align:start position:0% +dance if you get 400 volts you'll just +kind of scream and I don't care how + + align:start position:0% +kind of scream and I don't care how + + + align:start position:0% +kind of scream and I don't care how +manly men you guys are everyone makes + + align:start position:0% +manly men you guys are everyone makes + + + align:start position:0% +manly men you guys are everyone makes +the same pitch scream with 400 volts + + align:start position:0% +the same pitch scream with 400 volts + + + align:start position:0% +the same pitch scream with 400 volts +we're all equal in the eyes of + + align:start position:0% +we're all equal in the eyes of + + + align:start position:0% +we're all equal in the eyes of +electricity for these laboratory + + align:start position:0% +electricity for these laboratory + + + align:start position:0% +electricity for these laboratory +questions I'm going to ask you to both + + align:start position:0% +questions I'm going to ask you to both + + + align:start position:0% +questions I'm going to ask you to both +complete an assignment where you'll for + + align:start position:0% +complete an assignment where you'll for + + + align:start position:0% +complete an assignment where you'll for +example measure the half-life of uranium + + align:start position:0% +example measure the half-life of uranium + + + align:start position:0% +example measure the half-life of uranium +measure the radioactivity of one banana + + align:start position:0% +measure the radioactivity of one banana + + + align:start position:0% +measure the radioactivity of one banana +confirm or refute the linear + + align:start position:0% +confirm or refute the linear + + + align:start position:0% +confirm or refute the linear +no-threshold hypothesis of dose and the + + align:start position:0% +no-threshold hypothesis of dose and the + + + align:start position:0% +no-threshold hypothesis of dose and the +experiment itself won't take that long + + align:start position:0% +experiment itself won't take that long + + + align:start position:0% +experiment itself won't take that long +but I want you to write it up in proper + + align:start position:0% +but I want you to write it up in proper + + + align:start position:0% +but I want you to write it up in proper +documented format using these sections + + align:start position:0% +documented format using these sections + + + align:start position:0% +documented format using these sections +so I'm gonna be teaching you guys how to + + align:start position:0% +so I'm gonna be teaching you guys how to + + + align:start position:0% +so I'm gonna be teaching you guys how to +write scientific articles so actually + + align:start position:0% +write scientific articles so actually + + + align:start position:0% +write scientific articles so actually +this is a kind of good time to ask you + + align:start position:0% +this is a kind of good time to ask you + + + align:start position:0% +this is a kind of good time to ask you +guys how would you define the word + + align:start position:0% +guys how would you define the word + + + align:start position:0% +guys how would you define the word +science Luke what do you think gaining + + align:start position:0% +science Luke what do you think gaining + + + align:start position:0% +science Luke what do you think gaining +knowledge by fitting theories to + + align:start position:0% +knowledge by fitting theories to + + + align:start position:0% +knowledge by fitting theories to +empirical evidence okay so I hear + + align:start position:0% +empirical evidence okay so I hear + + + align:start position:0% +empirical evidence okay so I hear +knowledge gaining by some sort of well + + align:start position:0% +knowledge gaining by some sort of well + + + align:start position:0% +knowledge gaining by some sort of well +justified and accepted means right + + align:start position:0% +justified and accepted means right + + + align:start position:0% +justified and accepted means right +Monica what do you think + + align:start position:0% +Monica what do you think + + + align:start position:0% +Monica what do you think +[Music] + + align:start position:0% + + + + align:start position:0% + +cool + + align:start position:0% +cool + + + align:start position:0% +cool +let's say the study modeling an + + align:start position:0% +let's say the study modeling an + + + align:start position:0% +let's say the study modeling an +abstraction of the natural world in two + + align:start position:0% +abstraction of the natural world in two + + + align:start position:0% +abstraction of the natural world in two +ways we can understand see Jared what + + align:start position:0% +ways we can understand see Jared what + + + align:start position:0% +ways we can understand see Jared what +would you say oh there - Jared's oh I + + align:start position:0% +would you say oh there - Jared's oh I + + + align:start position:0% +would you say oh there - Jared's oh I +wanna hear both and then I'll yeah + + align:start position:0% + + + + align:start position:0% + +we said okay cool and other Jared yeah + + align:start position:0% + + + + align:start position:0% + +okay cool I like these and these are the + + align:start position:0% +okay cool I like these and these are the + + + align:start position:0% +okay cool I like these and these are the +these are the generally accepted + + align:start position:0% +these are the generally accepted + + + align:start position:0% +these are the generally accepted +theories and descriptions I've heard of + + align:start position:0% +theories and descriptions I've heard of + + + align:start position:0% +theories and descriptions I've heard of +science and I want to pose a question to + + align:start position:0% +science and I want to pose a question to + + + align:start position:0% +science and I want to pose a question to +you guys if a tree falls in the woods + + align:start position:0% +you guys if a tree falls in the woods + + + align:start position:0% +you guys if a tree falls in the woods +and nobody's around to hear it can it + + align:start position:0% +and nobody's around to hear it can it + + + align:start position:0% +and nobody's around to hear it can it +win the Nobel Prize it's kind of an + + align:start position:0% +win the Nobel Prize it's kind of an + + + align:start position:0% +win the Nobel Prize it's kind of an +expression so if somebody discovered the + + align:start position:0% +expression so if somebody discovered the + + + align:start position:0% +expression so if somebody discovered the +neutron and they wrote up their findings + + align:start position:0% +neutron and they wrote up their findings + + + align:start position:0% +neutron and they wrote up their findings +and prove that it exists and they put it + + align:start position:0% +and prove that it exists and they put it + + + align:start position:0% +and prove that it exists and they put it +in their desk and the house burned down + + align:start position:0% +in their desk and the house burned down + + + align:start position:0% +in their desk and the house burned down +and the person died was the neutron + + align:start position:0% +and the person died was the neutron + + + align:start position:0% +and the person died was the neutron +discovered what does discovered mean so + + align:start position:0% +discovered what does discovered mean so + + + align:start position:0% +discovered what does discovered mean so +to me science is equal parts everything + + align:start position:0% +to me science is equal parts everything + + + align:start position:0% +to me science is equal parts everything +you guys said and communication if you + + align:start position:0% +you guys said and communication if you + + + align:start position:0% +you guys said and communication if you +discover something and you don't tell + + align:start position:0% +discover something and you don't tell + + + align:start position:0% +discover something and you don't tell +anyone the information technically + + align:start position:0% +anyone the information technically + + + align:start position:0% +anyone the information technically +doesn't exist it dies with you and we + + align:start position:0% +doesn't exist it dies with you and we + + + align:start position:0% +doesn't exist it dies with you and we +don't want that to happen so I want to + + align:start position:0% +don't want that to happen so I want to + + + align:start position:0% +don't want that to happen so I want to +make sure that you guys both understand + + align:start position:0% +make sure that you guys both understand + + + align:start position:0% +make sure that you guys both understand +the science and understand how and the + + align:start position:0% +the science and understand how and the + + + align:start position:0% +the science and understand how and the +importance of communicating it + + align:start position:0% +importance of communicating it + + + align:start position:0% +importance of communicating it +effectively to people because that's the + + align:start position:0% +effectively to people because that's the + + + align:start position:0% +effectively to people because that's the +other thing you're gonna be doing as + + align:start position:0% +other thing you're gonna be doing as + + + align:start position:0% +other thing you're gonna be doing as +leaders in this field is explaining + + align:start position:0% +leaders in this field is explaining + + + align:start position:0% +leaders in this field is explaining +things + + align:start position:0% +things + + + align:start position:0% +things +you better believe when Fukushima + + align:start position:0% +you better believe when Fukushima + + + align:start position:0% +you better believe when Fukushima +happened I mean I was a postdoc at the + + align:start position:0% +happened I mean I was a postdoc at the + + + align:start position:0% +happened I mean I was a postdoc at the +time I was not a person I guess in the + + align:start position:0% +time I was not a person I guess in the + + + align:start position:0% +time I was not a person I guess in the +academic sense people here treated me + + align:start position:0% +academic sense people here treated me + + + align:start position:0% +academic sense people here treated me +very well when I was also very aware + + align:start position:0% +very well when I was also very aware + + + align:start position:0% +very well when I was also very aware +that I was not one of the greats still I + + align:start position:0% +that I was not one of the greats still I + + + align:start position:0% +that I was not one of the greats still I +am not old enough yet I was getting + + align:start position:0% +am not old enough yet I was getting + + + align:start position:0% +am not old enough yet I was getting +calls all day all night from news + + align:start position:0% +calls all day all night from news + + + align:start position:0% +calls all day all night from news +agencies saying you're at MIT I saw your + + align:start position:0% +agencies saying you're at MIT I saw your + + + align:start position:0% +agencies saying you're at MIT I saw your +name on the directory do a radio + + align:start position:0% +name on the directory do a radio + + + align:start position:0% +name on the directory do a radio +interview and tell us all if we're gonna + + align:start position:0% +interview and tell us all if we're gonna + + + align:start position:0% +interview and tell us all if we're gonna +die and you can only imagine what the + + align:start position:0% +die and you can only imagine what the + + + align:start position:0% +die and you can only imagine what the +professor's on this hall we're dealing + + align:start position:0% +professor's on this hall we're dealing + + + align:start position:0% +professor's on this hall we're dealing +with so folks were traveling around + + align:start position:0% +with so folks were traveling around + + + align:start position:0% +with so folks were traveling around +answering things left and right I ended + + align:start position:0% +answering things left and right I ended + + + align:start position:0% +answering things left and right I ended +up doing some weird podcast on a + + align:start position:0% +up doing some weird podcast on a + + + align:start position:0% +up doing some weird podcast on a +Brazilian news channel that I don't + + align:start position:0% +Brazilian news channel that I don't + + + align:start position:0% +Brazilian news channel that I don't +think he ever got aired and stopped + + align:start position:0% +think he ever got aired and stopped + + + align:start position:0% +think he ever got aired and stopped +doing it after that you as undergrads + + align:start position:0% +doing it after that you as undergrads + + + align:start position:0% +doing it after that you as undergrads +even might be called if somebody wants + + align:start position:0% +even might be called if somebody wants + + + align:start position:0% +even might be called if somebody wants +to know something and so it's best that + + align:start position:0% +to know something and so it's best that + + + align:start position:0% +to know something and so it's best that +you not only know the material but you + + align:start position:0% +you not only know the material but you + + + align:start position:0% +you not only know the material but you +can convey it effectively briefly an + + align:start position:0% +can convey it effectively briefly an + + + align:start position:0% +can convey it effectively briefly an +away + + align:start position:0% +away + + + align:start position:0% +away +that your audience can understand the + + align:start position:0% +that your audience can understand the + + + align:start position:0% +that your audience can understand the +audience for these articles is any + + align:start position:0% +audience for these articles is any + + + align:start position:0% +audience for these articles is any +undergraduate in any engineering program + + align:start position:0% +undergraduate in any engineering program + + + align:start position:0% +undergraduate in any engineering program +anywhere that's your lowest common + + align:start position:0% +anywhere that's your lowest common + + + align:start position:0% +anywhere that's your lowest common +denominator not to say that that's a bad + + align:start position:0% +denominator not to say that that's a bad + + + align:start position:0% +denominator not to say that that's a bad +thing but it is the audience that you + + align:start position:0% +thing but it is the audience that you + + + align:start position:0% +thing but it is the audience that you +want to aim your writing at so what I + + align:start position:0% +want to aim your writing at so what I + + + align:start position:0% +want to aim your writing at so what I +want you to be able to do is say what + + align:start position:0% +want you to be able to do is say what + + + align:start position:0% +want you to be able to do is say what +you did why you did it and what it means + + align:start position:0% +you did why you did it and what it means + + + align:start position:0% +you did why you did it and what it means +in communication terms this means a less + + align:start position:0% +in communication terms this means a less + + + align:start position:0% +in communication terms this means a less +than hundred word abstract a very brief + + align:start position:0% +than hundred word abstract a very brief + + + align:start position:0% +than hundred word abstract a very brief +synopsis of what you did and why it's + + align:start position:0% +synopsis of what you did and why it's + + + align:start position:0% +synopsis of what you did and why it's +important + + align:start position:0% +important + + + align:start position:0% +important +that's the teaser this is the trailer to + + align:start position:0% +that's the teaser this is the trailer to + + + align:start position:0% +that's the teaser this is the trailer to +make somebody read what you actually did + + align:start position:0% +make somebody read what you actually did + + + align:start position:0% +make somebody read what you actually did +and see why they care this is the main + + align:start position:0% +and see why they care this is the main + + + align:start position:0% +and see why they care this is the main +method and currency through which + + align:start position:0% +method and currency through which + + + align:start position:0% +method and currency through which +scientists communicate as articles of + + align:start position:0% +scientists communicate as articles of + + + align:start position:0% +scientists communicate as articles of +this type an introduction and background + + align:start position:0% +this type an introduction and background + + + align:start position:0% +this type an introduction and background +which says why are we studying this + + align:start position:0% +which says why are we studying this + + + align:start position:0% +which says why are we studying this +problem and the answer is not because I + + align:start position:0% +problem and the answer is not because I + + + align:start position:0% +problem and the answer is not because I +told you to and your grade depends on it + + align:start position:0% +told you to and your grade depends on it + + + align:start position:0% +told you to and your grade depends on it +I want you to think about why this + + align:start position:0% +I want you to think about why this + + + align:start position:0% +I want you to think about why this +problem is important and put it into + + align:start position:0% +problem is important and put it into + + + align:start position:0% +problem is important and put it into +context and give any of the scientific + + align:start position:0% +context and give any of the scientific + + + align:start position:0% +context and give any of the scientific +background to understand what's going to + + align:start position:0% +background to understand what's going to + + + align:start position:0% +background to understand what's going to +come next + + align:start position:0% +come next + + + align:start position:0% +come next +like the experimental section describe + + align:start position:0% +like the experimental section describe + + + align:start position:0% +like the experimental section describe +what you did an ad gritty scientific + + align:start position:0% +what you did an ad gritty scientific + + + align:start position:0% +what you did an ad gritty scientific +detail this is usually the easy part + + align:start position:0% +detail this is usually the easy part + + + align:start position:0% +detail this is usually the easy part +I put this gamma Dre in this bucket and + + align:start position:0% +I put this gamma Dre in this bucket and + + + align:start position:0% +I put this gamma Dre in this bucket and +it made this color and I made this noise + + align:start position:0% +it made this color and I made this noise + + + align:start position:0% +it made this color and I made this noise +you know whatever a results section + + align:start position:0% +you know whatever a results section + + + align:start position:0% +you know whatever a results section +where you show all of your data in a + + align:start position:0% +where you show all of your data in a + + + align:start position:0% +where you show all of your data in a +discussion section notice that these are + + align:start position:0% +discussion section notice that these are + + + align:start position:0% +discussion section notice that these are +different you want to separate your + + align:start position:0% +different you want to separate your + + + align:start position:0% +different you want to separate your +actual results from your interpretation + + align:start position:0% +actual results from your interpretation + + + align:start position:0% +actual results from your interpretation +of your results because someone else may + + align:start position:0% +of your results because someone else may + + + align:start position:0% +of your results because someone else may +have a very different interpretation of + + align:start position:0% +have a very different interpretation of + + + align:start position:0% +have a very different interpretation of +results for example Chadwick somebody + + align:start position:0% +results for example Chadwick somebody + + + align:start position:0% +results for example Chadwick somebody +found that beryllium bombarded by alpha + + align:start position:0% +found that beryllium bombarded by alpha + + + align:start position:0% +found that beryllium bombarded by alpha +particles emitted radiation of great + + align:start position:0% +particles emitted radiation of great + + + align:start position:0% +particles emitted radiation of great +penetrating power that's the result the + + align:start position:0% +penetrating power that's the result the + + + align:start position:0% +penetrating power that's the result the +interpretation or discussion said it's + + align:start position:0% +interpretation or discussion said it's + + + align:start position:0% +interpretation or discussion said it's +probably a Compton like effect from a + + align:start position:0% +probably a Compton like effect from a + + + align:start position:0% +probably a Compton like effect from a +photon by separating your results and + + align:start position:0% +photon by separating your results and + + + align:start position:0% +photon by separating your results and +your discussion you allow people to + + align:start position:0% +your discussion you allow people to + + + align:start position:0% +your discussion you allow people to +mentally say like okay I get your + + align:start position:0% +mentally say like okay I get your + + + align:start position:0% +mentally say like okay I get your +results I believe that you found these + + align:start position:0% +results I believe that you found these + + + align:start position:0% +results I believe that you found these +numbers I have a different explanation + + align:start position:0% +numbers I have a different explanation + + + align:start position:0% +numbers I have a different explanation +and you all may have different + + align:start position:0% +and you all may have different + + + align:start position:0% +and you all may have different +explanations for what you see in your + + align:start position:0% +explanations for what you see in your + + + align:start position:0% +explanations for what you see in your +own labs because you're also probably + + align:start position:0% +own labs because you're also probably + + + align:start position:0% +own labs because you're also probably +going to get different results and then + + align:start position:0% +going to get different results and then + + + align:start position:0% +going to get different results and then +finally a conclusion where you quickly + + align:start position:0% +finally a conclusion where you quickly + + + align:start position:0% +finally a conclusion where you quickly +risa mirai's or major contributions your + + align:start position:0% +risa mirai's or major contributions your + + + align:start position:0% +risa mirai's or major contributions your +abstracts the teaser your conclusion is + + align:start position:0% +abstracts the teaser your conclusion is + + + align:start position:0% +abstracts the teaser your conclusion is +like your reacts tracked with the + + align:start position:0% +like your reacts tracked with the + + + align:start position:0% +like your reacts tracked with the +context that + + align:start position:0% +context that + + + align:start position:0% +context that +people now believe or don't what you did + + align:start position:0% +people now believe or don't what you did + + + align:start position:0% +people now believe or don't what you did +and think about how you guys read + + align:start position:0% +and think about how you guys read + + + align:start position:0% +and think about how you guys read +articles so who here has read scientific + + align:start position:0% +articles so who here has read scientific + + + align:start position:0% +articles so who here has read scientific +articles before more than half of you + + align:start position:0% +articles before more than half of you + + + align:start position:0% +articles before more than half of you +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +Alex what do you read first that's right + + align:start position:0% +Alex what do you read first that's right + + + align:start position:0% +Alex what do you read first that's right +okay I'm glad you said that was my next + + align:start position:0% +okay I'm glad you said that was my next + + + align:start position:0% +okay I'm glad you said that was my next +question is you read the abstract the + + align:start position:0% +question is you read the abstract the + + + align:start position:0% +question is you read the abstract the +next thing you reads the conclusion the + + align:start position:0% +next thing you reads the conclusion the + + + align:start position:0% +next thing you reads the conclusion the +next thing you usually read is skim + + align:start position:0% +next thing you usually read is skim + + + align:start position:0% +next thing you usually read is skim +through the results in the figures and + + align:start position:0% +through the results in the figures and + + + align:start position:0% +through the results in the figures and +see if it's worth looking at then if + + align:start position:0% +see if it's worth looking at then if + + + align:start position:0% +see if it's worth looking at then if +you're like oh okay this is worth my + + align:start position:0% +you're like oh okay this is worth my + + + align:start position:0% +you're like oh okay this is worth my +time then you slog through and read + + align:start position:0% +time then you slog through and read + + + align:start position:0% +time then you slog through and read +everything to make sure you understand + + align:start position:0% +everything to make sure you understand + + + align:start position:0% +everything to make sure you understand +it all so when you're writing these + + align:start position:0% +it all so when you're writing these + + + align:start position:0% +it all so when you're writing these +articles think about who's reading them + + align:start position:0% +articles think about who's reading them + + + align:start position:0% +articles think about who's reading them +and will how they read them is if you + + align:start position:0% +and will how they read them is if you + + + align:start position:0% +and will how they read them is if you +guys don't tend to read an article from + + align:start position:0% +guys don't tend to read an article from + + + align:start position:0% +guys don't tend to read an article from +top to bottom neither will your audience + + align:start position:0% +top to bottom neither will your audience + + + align:start position:0% +top to bottom neither will your audience +and that's true most scientists skim + + align:start position:0% +and that's true most scientists skim + + + align:start position:0% +and that's true most scientists skim +things because we have a lot to read so + + align:start position:0% +things because we have a lot to read so + + + align:start position:0% +things because we have a lot to read so +that's okay and I am very interested in + + align:start position:0% +that's okay and I am very interested in + + + align:start position:0% +that's okay and I am very interested in +you guys completely documenting your + + align:start position:0% +you guys completely documenting your + + + align:start position:0% +you guys completely documenting your +experiment pictures are also awesome to + + align:start position:0% +experiment pictures are also awesome to + + + align:start position:0% +experiment pictures are also awesome to +use accuracy of results in analysis so + + align:start position:0% +use accuracy of results in analysis so + + + align:start position:0% +use accuracy of results in analysis so +did you round when you weren't supposed + + align:start position:0% +did you round when you weren't supposed + + + align:start position:0% +did you round when you weren't supposed +to did you have a clear numerical typo + + align:start position:0% +to did you have a clear numerical typo + + + align:start position:0% +to did you have a clear numerical typo +that you can't explain and the + + align:start position:0% +that you can't explain and the + + + align:start position:0% +that you can't explain and the +readability of the report I want you to + + align:start position:0% +readability of the report I want you to + + + align:start position:0% +readability of the report I want you to +spend time making this readable I expect + + align:start position:0% +spend time making this readable I expect + + + align:start position:0% +spend time making this readable I expect +that this part of the assignment will + + align:start position:0% +that this part of the assignment will + + + align:start position:0% +that this part of the assignment will +take roughly five hours or as the basic + + align:start position:0% +take roughly five hours or as the basic + + + align:start position:0% +take roughly five hours or as the basic +questions will take roughly three to + + align:start position:0% +questions will take roughly three to + + + align:start position:0% +questions will take roughly three to +four hours depending on how well you're + + align:start position:0% +four hours depending on how well you're + + + align:start position:0% +four hours depending on how well you're +doing and that leaves three hours of + + align:start position:0% +doing and that leaves three hours of + + + align:start position:0% +doing and that leaves three hours of +class time and a couple hours for + + align:start position:0% +class time and a couple hours for + + + align:start position:0% +class time and a couple hours for +whatever else happens life let's call it + + align:start position:0% +whatever else happens life let's call it + + + align:start position:0% +whatever else happens life let's call it +since you've never written these before + + align:start position:0% +since you've never written these before + + + align:start position:0% +since you've never written these before +wait a minute I shouldn't say that + + align:start position:0% +wait a minute I shouldn't say that + + + align:start position:0% +wait a minute I shouldn't say that +who's written these kinds of things + + align:start position:0% +who's written these kinds of things + + + align:start position:0% +who's written these kinds of things +before anyone here wrote a scientific + + align:start position:0% +before anyone here wrote a scientific + + + align:start position:0% +before anyone here wrote a scientific +article - okay three cool so most of you + + align:start position:0% +article - okay three cool so most of you + + + align:start position:0% +article - okay three cool so most of you +haven't and that's where I assumed you'd + + align:start position:0% +haven't and that's where I assumed you'd + + + align:start position:0% +haven't and that's where I assumed you'd +all be we have a whole lab dedicated to + + align:start position:0% +all be we have a whole lab dedicated to + + + align:start position:0% +all be we have a whole lab dedicated to +scientific communication called the comm + + align:start position:0% +scientific communication called the comm + + + align:start position:0% +scientific communication called the comm +lab run by someone who happens to be my + + align:start position:0% +lab run by someone who happens to be my + + + align:start position:0% +lab run by someone who happens to be my +wife four doors down we live and work + + align:start position:0% +wife four doors down we live and work + + + align:start position:0% +wife four doors down we live and work +next to each other it's pretty cool and + + align:start position:0% +next to each other it's pretty cool and + + + align:start position:0% +next to each other it's pretty cool and +you get an automatic three day extension + + align:start position:0% +you get an automatic three day extension + + + align:start position:0% +you get an automatic three day extension +on a lab assignment if you go to the + + align:start position:0% +on a lab assignment if you go to the + + + align:start position:0% +on a lab assignment if you go to the +comm lab there are three reasons for + + align:start position:0% +comm lab there are three reasons for + + + align:start position:0% +comm lab there are three reasons for +this one I want you to get better grades + + align:start position:0% +this one I want you to get better grades + + + align:start position:0% +this one I want you to get better grades +I want you to learn how to communicate - + + align:start position:0% +I want you to learn how to communicate - + + + align:start position:0% +I want you to learn how to communicate - +I don't want to spend time trying to + + align:start position:0% +I don't want to spend time trying to + + + align:start position:0% +I don't want to spend time trying to +figure out what you were trying to say + + align:start position:0% +figure out what you were trying to say + + + align:start position:0% +figure out what you were trying to say +so better articles means less grading + + align:start position:0% +so better articles means less grading + + + align:start position:0% +so better articles means less grading +time for me and three okay let's just + + align:start position:0% +time for me and three okay let's just + + + align:start position:0% +time for me and three okay let's just +say it's two reasons that's enough and + + align:start position:0% +say it's two reasons that's enough and + + + align:start position:0% +say it's two reasons that's enough and +for everything except for the quizzes + + align:start position:0% +for everything except for the quizzes + + + align:start position:0% +for everything except for the quizzes +it's perfectly okay to work together as + + align:start position:0% +it's perfectly okay to work together as + + + align:start position:0% +it's perfectly okay to work together as +long as you attribute who did what you + + align:start position:0% +long as you attribute who did what you + + + align:start position:0% +long as you attribute who did what you +write your own articles don't Xerox + + align:start position:0% +write your own articles don't Xerox + + + align:start position:0% +write your own articles don't Xerox +anything and say who took the data so if + + align:start position:0% +anything and say who took the data so if + + + align:start position:0% +anything and say who took the data so if +the whole class wants to get together + + align:start position:0% +the whole class wants to get together + + + align:start position:0% +the whole class wants to get together +and take one set of data and work for + + align:start position:0% +and take one set of data and work for + + + align:start position:0% +and take one set of data and work for +that fine if you all want to do the labs + + align:start position:0% +that fine if you all want to do the labs + + + align:start position:0% +that fine if you all want to do the labs +yourselves which I highly recommend fine + + align:start position:0% +yourselves which I highly recommend fine + + + align:start position:0% +yourselves which I highly recommend fine +but I'm not going to tell you how to do + + align:start position:0% +but I'm not going to tell you how to do + + + align:start position:0% +but I'm not going to tell you how to do +the lab assignment in certain to this as + + align:start position:0% +the lab assignment in certain to this as + + + align:start position:0% +the lab assignment in certain to this as +long as you say what you did and I want + + align:start position:0% +long as you say what you did and I want + + + align:start position:0% +long as you say what you did and I want +all of you if you haven't yet to head to + + align:start position:0% +all of you if you haven't yet to head to + + + align:start position:0% +all of you if you haven't yet to head to +integrity down mit.edu to see our + + align:start position:0% +integrity down mit.edu to see our + + + align:start position:0% +integrity down mit.edu to see our +official policies on what is considered + + align:start position:0% +official policies on what is considered + + + align:start position:0% +official policies on what is considered +plagiarism what is considered working + + align:start position:0% +plagiarism what is considered working + + + align:start position:0% +plagiarism what is considered working +together what's considered academic + + align:start position:0% +together what's considered academic + + + align:start position:0% +together what's considered academic +honesty I will assume because it's on + + align:start position:0% +honesty I will assume because it's on + + + align:start position:0% +honesty I will assume because it's on +the syllabus and I'm telling you now + + align:start position:0% +the syllabus and I'm telling you now + + + align:start position:0% +the syllabus and I'm telling you now +that you've all read this and that there + + align:start position:0% +that you've all read this and that there + + + align:start position:0% +that you've all read this and that there +will be no cheating it's just not + + align:start position:0% +will be no cheating it's just not + + + align:start position:0% +will be no cheating it's just not +something that's part of my job + + align:start position:0% +something that's part of my job + + + align:start position:0% +something that's part of my job +description and I don't want to deal + + align:start position:0% +description and I don't want to deal + + + align:start position:0% +description and I don't want to deal +with it which means I won't deal with it + + align:start position:0% +with it which means I won't deal with it + + + align:start position:0% +with it which means I won't deal with it +which means the consequences will be + + align:start position:0% +which means the consequences will be + + + align:start position:0% +which means the consequences will be +severe so I don't think I'll have to + + align:start position:0% +severe so I don't think I'll have to + + + align:start position:0% +severe so I don't think I'll have to +worry about that and then for the late + + align:start position:0% +worry about that and then for the late + + + align:start position:0% +worry about that and then for the late +policy it's just 10% of the value of + + align:start position:0% +policy it's just 10% of the value of + + + align:start position:0% +policy it's just 10% of the value of +assignment for each calendar day not + + align:start position:0% +assignment for each calendar day not + + + align:start position:0% +assignment for each calendar day not +each business day so if you're running + + align:start position:0% +each business day so if you're running + + + align:start position:0% +each business day so if you're running +really late and you haven't started an + + align:start position:0% +really late and you haven't started an + + + align:start position:0% +really late and you haven't started an +assignment the day it's due better to + + align:start position:0% +assignment the day it's due better to + + + align:start position:0% +assignment the day it's due better to +take the 10% penalty and do really well + + align:start position:0% +take the 10% penalty and do really well + + + align:start position:0% +take the 10% penalty and do really well +then hand in nothing on time so keep in + + align:start position:0% +then hand in nothing on time so keep in + + + align:start position:0% +then hand in nothing on time so keep in +mind how can you maximize the points in + + align:start position:0% +mind how can you maximize the points in + + + align:start position:0% +mind how can you maximize the points in +this course is I'd rather you hand in + + align:start position:0% +this course is I'd rather you hand in + + + align:start position:0% +this course is I'd rather you hand in +something good late than terrible on + + align:start position:0% +something good late than terrible on + + + align:start position:0% +something good late than terrible on +time so if you really need that extra + + align:start position:0% +time so if you really need that extra + + + align:start position:0% +time so if you really need that extra +day if MIT gets crazy take it 10% of a + + align:start position:0% +day if MIT gets crazy take it 10% of a + + + align:start position:0% +day if MIT gets crazy take it 10% of a +problem set is point four points on your + + align:start position:0% +problem set is point four points on your + + + align:start position:0% +problem set is point four points on your +grade it's not that big a deal then as + + align:start position:0% +grade it's not that big a deal then as + + + align:start position:0% +grade it's not that big a deal then as +far as the syllabus I want to show you + + align:start position:0% +far as the syllabus I want to show you + + + align:start position:0% +far as the syllabus I want to show you +very quickly we've got when things are + + align:start position:0% +very quickly we've got when things are + + + align:start position:0% +very quickly we've got when things are +due I'm going to change these dates that + + align:start position:0% +due I'm going to change these dates that + + + align:start position:0% +due I'm going to change these dates that +basically just shift them all forward by + + align:start position:0% +basically just shift them all forward by + + + align:start position:0% +basically just shift them all forward by +one day to account for the new Tuesday + + align:start position:0% +one day to account for the new Tuesday + + + align:start position:0% +one day to account for the new Tuesday +Thursday classes so I've got when the + + align:start position:0% +Thursday classes so I've got when the + + + align:start position:0% +Thursday classes so I've got when the +problem sets are due and Friday's + + align:start position:0% +problem sets are due and Friday's + + + align:start position:0% +problem sets are due and Friday's +recitation activities if there aren't + + align:start position:0% +recitation activities if there aren't + + + align:start position:0% +recitation activities if there aren't +too many questions on a particular + + align:start position:0% +too many questions on a particular + + + align:start position:0% +too many questions on a particular +Friday I have a lot of fun stuff in + + align:start position:0% +Friday I have a lot of fun stuff in + + + align:start position:0% +Friday I have a lot of fun stuff in +store for you for example tomorrow we're + + align:start position:0% +store for you for example tomorrow we're + + + align:start position:0% +store for you for example tomorrow we're +going to be talking about radiation + + align:start position:0% +going to be talking about radiation + + + align:start position:0% +going to be talking about radiation +utilizing technology including plasma + + align:start position:0% +utilizing technology including plasma + + + align:start position:0% +utilizing technology including plasma +spider coders one of which we have set + + align:start position:0% +spider coders one of which we have set + + + align:start position:0% +spider coders one of which we have set +up in my lab + + align:start position:0% +up in my lab + + + align:start position:0% +up in my lab +like to show you because it's a way that + + align:start position:0% +like to show you because it's a way that + + + align:start position:0% +like to show you because it's a way that +you can coat materials and other + + align:start position:0% +you can coat materials and other + + + align:start position:0% +you can coat materials and other +materials and you have to generate this + + align:start position:0% +materials and you have to generate this + + + align:start position:0% +materials and you have to generate this +beautiful glowing purple plasma in order + + align:start position:0% +beautiful glowing purple plasma in order + + + align:start position:0% +beautiful glowing purple plasma in order +to do so + + align:start position:0% +to do so + + + align:start position:0% +to do so +so you ionize nitrogen you induce + + align:start position:0% +so you ionize nitrogen you induce + + + align:start position:0% +so you ionize nitrogen you induce +sputtering which is a radiation damage + + align:start position:0% +sputtering which is a radiation damage + + + align:start position:0% +sputtering which is a radiation damage +process which we'll be going over to + + align:start position:0% +process which we'll be going over to + + + align:start position:0% +process which we'll be going over to +coat things and other things there will + + align:start position:0% +coat things and other things there will + + + align:start position:0% +coat things and other things there will +be once in a while where I have to shift + + align:start position:0% +be once in a while where I have to shift + + + align:start position:0% +be once in a while where I have to shift +a class in to recitation because I'll be + + align:start position:0% +a class in to recitation because I'll be + + + align:start position:0% +a class in to recitation because I'll be +at Westinghouse or in Russia and I think + + align:start position:0% +at Westinghouse or in Russia and I think + + + align:start position:0% +at Westinghouse or in Russia and I think +that's only twice during the whole year + + align:start position:0% +that's only twice during the whole year + + + align:start position:0% +that's only twice during the whole year +so you won't miss any classes we'll just + + align:start position:0% +so you won't miss any classes we'll just + + + align:start position:0% +so you won't miss any classes we'll just +use the recitation time and then other + + align:start position:0% +use the recitation time and then other + + + align:start position:0% +use the recitation time and then other +times we'll be doing measuring the + + align:start position:0% +times we'll be doing measuring the + + + align:start position:0% +times we'll be doing measuring the +radioactivity of banana ashes or once we + + align:start position:0% +radioactivity of banana ashes or once we + + + align:start position:0% +radioactivity of banana ashes or once we +talk about electron interactions we're + + align:start position:0% +talk about electron interactions we're + + + align:start position:0% +talk about electron interactions we're +going to go use a scanning electron + + align:start position:0% +going to go use a scanning electron + + + align:start position:0% +going to go use a scanning electron +microscope the carrot at the end of the + + align:start position:0% +microscope the carrot at the end of the + + + align:start position:0% +microscope the carrot at the end of the +stick to make sure that you guys do well + + align:start position:0% +stick to make sure that you guys do well + + + align:start position:0% +stick to make sure that you guys do well +the top two people performing on the + + align:start position:0% +the top two people performing on the + + + align:start position:0% +the top two people performing on the +quizzes get to pilot and choose the + + align:start position:0% +quizzes get to pilot and choose the + + + align:start position:0% +quizzes get to pilot and choose the +samples for the SEM and elemental + + align:start position:0% +samples for the SEM and elemental + + + align:start position:0% +samples for the SEM and elemental +analysis and the focused ion beam + + align:start position:0% +analysis and the focused ion beam + + + align:start position:0% +analysis and the focused ion beam +demonstration so you guys get to pilot + + align:start position:0% +demonstration so you guys get to pilot + + + align:start position:0% +demonstration so you guys get to pilot +something that's let's say is + + align:start position:0% +something that's let's say is + + + align:start position:0% +something that's let's say is +complicated as a Space Shuttle but deals + + align:start position:0% +complicated as a Space Shuttle but deals + + + align:start position:0% +complicated as a Space Shuttle but deals +with things much much smaller so I'll + + align:start position:0% +with things much much smaller so I'll + + + align:start position:0% +with things much much smaller so I'll +put you in the driver's seat in the + + align:start position:0% +put you in the driver's seat in the + + + align:start position:0% +put you in the driver's seat in the +machines of our lab and you get to bring + + align:start position:0% +machines of our lab and you get to bring + + + align:start position:0% +machines of our lab and you get to bring +whatever you want to analyze and find + + align:start position:0% +whatever you want to analyze and find + + + align:start position:0% +whatever you want to analyze and find +the elemental analysis of and use the + + align:start position:0% +the elemental analysis of and use the + + + align:start position:0% +the elemental analysis of and use the +world's smallest machining instrument + + align:start position:0% +world's smallest machining instrument + + + align:start position:0% +world's smallest machining instrument +that can cut 5 nanometer slices of + + align:start position:0% +that can cut 5 nanometer slices of + + + align:start position:0% +that can cut 5 nanometer slices of +things using processes that we're going + + align:start position:0% +things using processes that we're going + + + align:start position:0% +things using processes that we're going +to discuss in this class so the better + + align:start position:0% +to discuss in this class so the better + + + align:start position:0% +to discuss in this class so the better +you do the more you get to use it and at + + align:start position:0% +you do the more you get to use it and at + + + align:start position:0% +you do the more you get to use it and at +the end we'll have a nice debate I call + + align:start position:0% +the end we'll have a nice debate I call + + + align:start position:0% +the end we'll have a nice debate I call +arguing with Greenpeace when we'll talk + + align:start position:0% +arguing with Greenpeace when we'll talk + + + align:start position:0% +arguing with Greenpeace when we'll talk +about now that you'll have known all of + + align:start position:0% +about now that you'll have known all of + + + align:start position:0% +about now that you'll have known all of +the nuclear science and engineering and + + align:start position:0% +the nuclear science and engineering and + + + align:start position:0% +the nuclear science and engineering and +can speak scientifically about topics + + align:start position:0% +can speak scientifically about topics + + + align:start position:0% +can speak scientifically about topics +we're going to go after a lot of + + align:start position:0% +we're going to go after a lot of + + + align:start position:0% +we're going to go after a lot of +societal misconceptions do cell phones + + align:start position:0% +societal misconceptions do cell phones + + + align:start position:0% +societal misconceptions do cell phones +cause cancer does living near a nuclear + + align:start position:0% +cause cancer does living near a nuclear + + + align:start position:0% +cause cancer does living near a nuclear +power plant cause cancer does arguing + + align:start position:0% +power plant cause cancer does arguing + + + align:start position:0% +power plant cause cancer does arguing +with Greenpeace cause cancer whatever + + align:start position:0% +with Greenpeace cause cancer whatever + + + align:start position:0% +with Greenpeace cause cancer whatever +it's going to be so I want to make sure + + align:start position:0% +it's going to be so I want to make sure + + + align:start position:0% +it's going to be so I want to make sure +that you're well-equipped and confident + + align:start position:0% +that you're well-equipped and confident + + + align:start position:0% +that you're well-equipped and confident +enough to go out there and hold your own + + align:start position:0% +enough to go out there and hold your own + + + align:start position:0% +enough to go out there and hold your own +in a vigorous debate with an angry + + align:start position:0% +in a vigorous debate with an angry + + + align:start position:0% +in a vigorous debate with an angry +emotional environmentalist you guys will + + align:start position:0% +emotional environmentalist you guys will + + + align:start position:0% +emotional environmentalist you guys will +be calm peaceful and informed + + align:start position:0% +be calm peaceful and informed + + + align:start position:0% +be calm peaceful and informed +environmentalists after all that's why a + + align:start position:0% +environmentalists after all that's why a + + + align:start position:0% +environmentalists after all that's why a +lot of us are here is we want nuclear + + align:start position:0% +lot of us are here is we want nuclear + + + align:start position:0% +lot of us are here is we want nuclear +energy to happen because we care about + + align:start position:0% +energy to happen because we care about + + + align:start position:0% +energy to happen because we care about +the environment + + align:start position:0% +the environment + + + align:start position:0% +the environment +there's other people that don't want + + align:start position:0% +there's other people that don't want + + + align:start position:0% +there's other people that don't want +nuclear energy to happen because they + + align:start position:0% +nuclear energy to happen because they + + + align:start position:0% +nuclear energy to happen because they +care about the environment to each their + + align:start position:0% +care about the environment to each their + + + align:start position:0% +care about the environment to each their +own I guess motivations but I want to + + align:start position:0% +own I guess motivations but I want to + + + align:start position:0% +own I guess motivations but I want to +make sure you're well equipped + + align:start position:0% +make sure you're well equipped + + + align:start position:0% +make sure you're well equipped +to also tackle things like is food or + + align:start position:0% +to also tackle things like is food or + + + align:start position:0% +to also tackle things like is food or +radiation that there's all sorts of + + align:start position:0% +radiation that there's all sorts of + + + align:start position:0% +radiation that there's all sorts of +websites with dancing babies and weird + + align:start position:0% +websites with dancing babies and weird + + + align:start position:0% +websites with dancing babies and weird +geo cities like graphics saying food or + + align:start position:0% +geo cities like graphics saying food or + + + align:start position:0% +geo cities like graphics saying food or +radiations evil you won't find a lot of + + align:start position:0% +radiations evil you won't find a lot of + + + align:start position:0% +radiations evil you won't find a lot of +scientific articles that's the case and + + align:start position:0% +scientific articles that's the case and + + + align:start position:0% +scientific articles that's the case and +to see if you'll put your lets say + + align:start position:0% +to see if you'll put your lets say + + + align:start position:0% +to see if you'll put your lets say +cancer risk where your mouth is the last + + align:start position:0% +cancer risk where your mouth is the last + + + align:start position:0% +cancer risk where your mouth is the last +day of class will have an irradiated + + align:start position:0% +day of class will have an irradiated + + + align:start position:0% +day of class will have an irradiated +fruit party or I'll be buying only the + + align:start position:0% +fruit party or I'll be buying only the + + + align:start position:0% +fruit party or I'll be buying only the +kinds of fruit that can be imported into + + align:start position:0% +kinds of fruit that can be imported into + + + align:start position:0% +kinds of fruit that can be imported into +the US because food irradiation is done + + align:start position:0% +the US because food irradiation is done + + + align:start position:0% +the US because food irradiation is done +otherwise the USDA would not let it in + + align:start position:0% +otherwise the USDA would not let it in + + + align:start position:0% +otherwise the USDA would not let it in +the country and this is mostly things + + align:start position:0% +the country and this is mostly things + + + align:start position:0% +the country and this is mostly things +like mangosteens from Thailand pineapple + + align:start position:0% +like mangosteens from Thailand pineapple + + + align:start position:0% +like mangosteens from Thailand pineapple +from Costa Rica and interestingly enough + + align:start position:0% +from Costa Rica and interestingly enough + + + align:start position:0% +from Costa Rica and interestingly enough +Hawaii is considered a different country + + align:start position:0% +Hawaii is considered a different country + + + align:start position:0% +Hawaii is considered a different country +agriculturally it is so far away that + + align:start position:0% +agriculturally it is so far away that + + + align:start position:0% +agriculturally it is so far away that +they have different agricultural pests + + align:start position:0% +they have different agricultural pests + + + align:start position:0% +they have different agricultural pests +and without a radiation we couldn't + + align:start position:0% +and without a radiation we couldn't + + + align:start position:0% +and without a radiation we couldn't +import some of the produce from Hawaii + + align:start position:0% +import some of the produce from Hawaii + + + align:start position:0% +import some of the produce from Hawaii +because it could decimate some of the + + align:start position:0% +because it could decimate some of the + + + align:start position:0% +because it could decimate some of the +crops in the continental US pretty crazy + + align:start position:0% +crops in the continental US pretty crazy + + + align:start position:0% +crops in the continental US pretty crazy +huh yeah it's the fifth it's the what + + align:start position:0% +huh yeah it's the fifth it's the what + + + align:start position:0% +huh yeah it's the fifth it's the what +it's at the 49th state but + + align:start position:0% +it's at the 49th state but + + + align:start position:0% +it's at the 49th state but +agriculturally a different country so + + align:start position:0% +agriculturally a different country so + + + align:start position:0% +agriculturally a different country so +it's about five till so I'm going to + + align:start position:0% +it's about five till so I'm going to + + + align:start position:0% +it's about five till so I'm going to +stop here and we will start with + + align:start position:0% +stop here and we will start with + + + align:start position:0% +stop here and we will start with +radiation utilizing technology on Friday + + align:start position:0% +radiation utilizing technology on Friday + + + align:start position:0% +radiation utilizing technology on Friday +tomorrow + + align:start position:0% +tomorrow + + + align:start position:0% +tomorrow +downstairs in room 24 121 and then we'll + + align:start position:0% +downstairs in room 24 121 and then we'll + + + align:start position:0% +downstairs in room 24 121 and then we'll +move over to my lab at two o'clock to + + align:start position:0% +move over to my lab at two o'clock to + + + align:start position:0% +move over to my lab at two o'clock to +see the plasma sputter coder + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/7UJ4CFRGd-U.txt b/7UJ4CFRGd-U.txt new file mode 100644 index 0000000000000000000000000000000000000000..42a2a59edadb18313ce330edac3bd347e35b50ad --- /dev/null +++ b/7UJ4CFRGd-U.txt @@ -0,0 +1,1027 @@ +align:start position:0% + +well you have a lot of followers of your + + align:start position:0% +well you have a lot of followers of your + + + align:start position:0% +well you have a lot of followers of your +1806 videos and I'll read this quote to + + align:start position:0% +1806 videos and I'll read this quote to + + + align:start position:0% +1806 videos and I'll read this quote to +you a commenter even noted that this is + + align:start position:0% +you a commenter even noted that this is + + + align:start position:0% +you a commenter even noted that this is +not lecture this is art gosh okay well + + align:start position:0% +not lecture this is art gosh okay well + + + align:start position:0% +not lecture this is art gosh okay well +if you're going to ask you what's my + + align:start position:0% +if you're going to ask you what's my + + + align:start position:0% +if you're going to ask you what's my +system I have none I I guess well first + + align:start position:0% +system I have none I I guess well first + + + align:start position:0% +system I have none I I guess well first +I'd like students and I want to help and + + align:start position:0% +I'd like students and I want to help and + + + align:start position:0% +I'd like students and I want to help and +maybe the key point is to think with + + align:start position:0% +maybe the key point is to think with + + + align:start position:0% +maybe the key point is to think with +them that not to just say okay here it + + align:start position:0% +them that not to just say okay here it + + + align:start position:0% +them that not to just say okay here it +is listen listen up + + align:start position:0% +is listen listen up + + + align:start position:0% +is listen listen up +I think through the question all over + + align:start position:0% +I think through the question all over + + + align:start position:0% +I think through the question all over +again as they do and they and you have + + align:start position:0% +again as they do and they and you have + + + align:start position:0% +again as they do and they and you have +to give time you can't zip through a + + align:start position:0% +to give time you can't zip through a + + + align:start position:0% +to give time you can't zip through a +proof because this class has to be sort + + align:start position:0% +proof because this class has to be sort + + + align:start position:0% +proof because this class has to be sort +of thinking with you and that's yeah + + align:start position:0% +of thinking with you and that's yeah + + + align:start position:0% +of thinking with you and that's yeah +that's my thought I don't know if I + + align:start position:0% +that's my thought I don't know if I + + + align:start position:0% +that's my thought I don't know if I +achieve it but I think it's the goal one + + align:start position:0% +achieve it but I think it's the goal one + + + align:start position:0% +achieve it but I think it's the goal one +of our users on OCW noted that during + + align:start position:0% +of our users on OCW noted that during + + + align:start position:0% +of our users on OCW noted that during +lectures you sometimes ask rhetorical + + align:start position:0% +lectures you sometimes ask rhetorical + + + align:start position:0% +lectures you sometimes ask rhetorical +questions or maybe feign confusion as a + + align:start position:0% +questions or maybe feign confusion as a + + + align:start position:0% +questions or maybe feign confusion as a +way to gain country I'm confused + + align:start position:0% +way to gain country I'm confused + + + align:start position:0% +way to gain country I'm confused +well no well no it's probably true + + align:start position:0% +well no well no it's probably true + + + align:start position:0% +well no well no it's probably true +that's maybe part of not rushing through + + align:start position:0% +that's maybe part of not rushing through + + + align:start position:0% +that's maybe part of not rushing through +it but getting this so I'll pause to add + + align:start position:0% +it but getting this so I'll pause to add + + + align:start position:0% +it but getting this so I'll pause to add +that the critical point maybe and give + + align:start position:0% +that the critical point maybe and give + + + align:start position:0% +that the critical point maybe and give +you have to give time to to just see + + align:start position:0% +you have to give time to to just see + + + align:start position:0% +you have to give time to to just see +okay what's the next step + + align:start position:0% +okay what's the next step + + + align:start position:0% +okay what's the next step +you know it's mathematics is beautifully + + align:start position:0% +you know it's mathematics is beautifully + + + align:start position:0% +you know it's mathematics is beautifully +ordered and sensible and logical and + + align:start position:0% +ordered and sensible and logical and + + + align:start position:0% +ordered and sensible and logical and +linear algebra is not too difficult but + + align:start position:0% +linear algebra is not too difficult but + + + align:start position:0% +linear algebra is not too difficult but +still you can't rush you have to sort of + + align:start position:0% +still you can't rush you have to sort of + + + align:start position:0% +still you can't rush you have to sort of +see the idea a few times + + align:start position:0% +see the idea a few times + + + align:start position:0% +see the idea a few times +mmm-hmm first maybe on the board as + + align:start position:0% +mmm-hmm first maybe on the board as + + + align:start position:0% +mmm-hmm first maybe on the board as +symbols but not everybody + + align:start position:0% +symbols but not everybody + + + align:start position:0% +symbols but not everybody +except on cymbals then you say what does + + align:start position:0% +except on cymbals then you say what does + + + align:start position:0% +except on cymbals then you say what does +it mean and then finally you say why is + + align:start position:0% +it mean and then finally you say why is + + + align:start position:0% +it mean and then finally you say why is +it true but you don't say why is it true + + align:start position:0% +it true but you don't say why is it true + + + align:start position:0% +it true but you don't say why is it true +give the proof + + align:start position:0% +give the proof + + + align:start position:0% +give the proof +the very first step yeah you want to + + align:start position:0% +the very first step yeah you want to + + + align:start position:0% +the very first step yeah you want to +make people think yeah it is true mmm + + align:start position:0% +make people think yeah it is true mmm + + + align:start position:0% +make people think yeah it is true mmm +others have noted that you do this thing + + align:start position:0% +others have noted that you do this thing + + + align:start position:0% +others have noted that you do this thing +where you display your own thinking kind + + align:start position:0% +where you display your own thinking kind + + + align:start position:0% +where you display your own thinking kind +of on the spot as you work through + + align:start position:0% +of on the spot as you work through + + + align:start position:0% +of on the spot as you work through +problems yeah is there ever a risk in + + align:start position:0% +problems yeah is there ever a risk in + + + align:start position:0% +problems yeah is there ever a risk in +that oh yes + + align:start position:0% +that oh yes + + + align:start position:0% +that oh yes +and it happens that I lose the thread or + + align:start position:0% +and it happens that I lose the thread or + + + align:start position:0% +and it happens that I lose the thread or +I come up to a dead end where I don't + + align:start position:0% +I come up to a dead end where I don't + + + align:start position:0% +I come up to a dead end where I don't +know what I'm supposed to do next but + + align:start position:0% +know what I'm supposed to do next but + + + align:start position:0% +know what I'm supposed to do next but +generally especially in 1806 the basic + + align:start position:0% +generally especially in 1806 the basic + + + align:start position:0% +generally especially in 1806 the basic +linear algebra course that many people + + align:start position:0% +linear algebra course that many people + + + align:start position:0% +linear algebra course that many people +have watched there I kind of get it okay + + align:start position:0% +have watched there I kind of get it okay + + + align:start position:0% +have watched there I kind of get it okay +yeah I've taught it enough times to have + + align:start position:0% +yeah I've taught it enough times to have + + + align:start position:0% +yeah I've taught it enough times to have +a good chance of getting it right is + + align:start position:0% +a good chance of getting it right is + + + align:start position:0% +a good chance of getting it right is +this a strategy that you developed over + + align:start position:0% +this a strategy that you developed over + + + align:start position:0% +this a strategy that you developed over +time you know lots of people are nervous + + align:start position:0% +time you know lots of people are nervous + + + align:start position:0% +time you know lots of people are nervous +to do that to you know make themselves + + align:start position:0% +to do that to you know make themselves + + + align:start position:0% +to do that to you know make themselves +vulnerable in front of a large lecture + + align:start position:0% +vulnerable in front of a large lecture + + + align:start position:0% +vulnerable in front of a large lecture +class like that but you're you're + + align:start position:0% +class like that but you're you're + + + align:start position:0% +class like that but you're you're +working problems in real time and + + align:start position:0% +working problems in real time and + + + align:start position:0% +working problems in real time and +demonstrating what happens when you hit + + align:start position:0% +demonstrating what happens when you hit + + + align:start position:0% +demonstrating what happens when you hit +a dead end well that's okay because + + align:start position:0% +a dead end well that's okay because + + + align:start position:0% +a dead end well that's okay because +students are gonna hit dead end so it + + align:start position:0% +students are gonna hit dead end so it + + + align:start position:0% +students are gonna hit dead end so it +seems to me it's okay for me to get + + align:start position:0% +seems to me it's okay for me to get + + + align:start position:0% +seems to me it's okay for me to get +stuck too and then given they see oh + + align:start position:0% +stuck too and then given they see oh + + + align:start position:0% +stuck too and then given they see oh +okay maybe this this is the way to get + + align:start position:0% +okay maybe this this is the way to get + + + align:start position:0% +okay maybe this this is the way to get +out of that corner yeah so essentially I + + align:start position:0% +out of that corner yeah so essentially I + + + align:start position:0% +out of that corner yeah so essentially I +think the thing is I like students I + + align:start position:0% +think the thing is I like students I + + + align:start position:0% +think the thing is I like students I +like math and putting them together is + + align:start position:0% +like math and putting them together is + + + align:start position:0% +like math and putting them together is +just the best job in the world let's + + align:start position:0% +just the best job in the world let's + + + align:start position:0% +just the best job in the world let's +talk about humor for a second okay + + align:start position:0% +talk about humor for a second okay + + + align:start position:0% +talk about humor for a second okay +you've been known to say things like + + align:start position:0% +you've been known to say things like + + + align:start position:0% +you've been known to say things like +keep things in their Gosse give an order + + align:start position:0% +keep things in their Gosse give an order + + + align:start position:0% +keep things in their Gosse give an order +and they're like really funny things + + align:start position:0% +and they're like really funny things + + + align:start position:0% +and they're like really funny things +that people just love so what's the role + + align:start position:0% +that people just love so what's the role + + + align:start position:0% +that people just love so what's the role +of humor in your teaching well it may be + + align:start position:0% +of humor in your teaching well it may be + + + align:start position:0% +of humor in your teaching well it may be +it's which is what I'm saying here is + + align:start position:0% +it's which is what I'm saying here is + + + align:start position:0% +it's which is what I'm saying here is +maybe the key point is to make it human + + align:start position:0% +maybe the key point is to make it human + + + align:start position:0% +maybe the key point is to make it human +you know you're + + align:start position:0% +you know you're + + + align:start position:0% +you know you're +your you're a person like this student + + align:start position:0% +your you're a person like this student + + + align:start position:0% +your you're a person like this student +is a person the book isn't quite a + + align:start position:0% +is a person the book isn't quite a + + + align:start position:0% +is a person the book isn't quite a +person but it was written by a person + + align:start position:0% +person but it was written by a person + + + align:start position:0% +person but it was written by a person +and to see that it's just like a natural + + align:start position:0% +and to see that it's just like a natural + + + align:start position:0% +and to see that it's just like a natural +thing to do yeah so one of our users was + + align:start position:0% +thing to do yeah so one of our users was + + + align:start position:0% +thing to do yeah so one of our users was +thinking about how you teach complex + + align:start position:0% +thinking about how you teach complex + + + align:start position:0% +thinking about how you teach complex +material how you convey it in ways that + + align:start position:0% +material how you convey it in ways that + + + align:start position:0% +material how you convey it in ways that +are comfortable for students and the + + align:start position:0% +are comfortable for students and the + + + align:start position:0% +are comfortable for students and the +user was wondering how do you know when + + align:start position:0% +user was wondering how do you know when + + + align:start position:0% +user was wondering how do you know when +to go into detail and when not to + + align:start position:0% +to go into detail and when not to + + + align:start position:0% +to go into detail and when not to +I suppose I try to think it through + + align:start position:0% +I suppose I try to think it through + + + align:start position:0% +I suppose I try to think it through +once again and that then you sort of + + align:start position:0% +once again and that then you sort of + + + align:start position:0% +once again and that then you sort of +automatically see the word you we + + align:start position:0% +automatically see the word you we + + + align:start position:0% +automatically see the word you we +recognize what words you need to use and + + align:start position:0% +recognize what words you need to use and + + + align:start position:0% +recognize what words you need to use and +what step what the steps are yeah if you + + align:start position:0% +what step what the steps are yeah if you + + + align:start position:0% +what step what the steps are yeah if you +if you don't if you're not thinking of + + align:start position:0% +if you don't if you're not thinking of + + + align:start position:0% +if you don't if you're not thinking of +yourself then you're probably going too + + align:start position:0% +yourself then you're probably going too + + + align:start position:0% +yourself then you're probably going too +fast and not connecting with the + + align:start position:0% +fast and not connecting with the + + + align:start position:0% +fast and not connecting with the +thinking of the class and how do you + + align:start position:0% +thinking of the class and how do you + + + align:start position:0% +thinking of the class and how do you +connect with the thinking of the class + + align:start position:0% +connect with the thinking of the class + + + align:start position:0% +connect with the thinking of the class +when it's such a large lecture hall what + + align:start position:0% +when it's such a large lecture hall what + + + align:start position:0% +when it's such a large lecture hall what +ones that are different that's in there + + align:start position:0% +ones that are different that's in there + + + align:start position:0% +ones that are different that's in there +that's probably true and of course you + + align:start position:0% +that's probably true and of course you + + + align:start position:0% +that's probably true and of course you +don't know what everybody's thinking in + + align:start position:0% +don't know what everybody's thinking in + + + align:start position:0% +don't know what everybody's thinking in +that class but overall if you get if you + + align:start position:0% +that class but overall if you get if you + + + align:start position:0% +that class but overall if you get if you +say sort of conscious of the class + + align:start position:0% +say sort of conscious of the class + + + align:start position:0% +say sort of conscious of the class +conscious of where they are that's I + + align:start position:0% +conscious of where they are that's I + + + align:start position:0% +conscious of where they are that's I +think the same for any speaker to be + + align:start position:0% +think the same for any speaker to be + + + align:start position:0% +think the same for any speaker to be +conscious of the audience and not just + + align:start position:0% +conscious of the audience and not just + + + align:start position:0% +conscious of the audience and not just +of a B inverse what else would you like + + align:start position:0% +of a B inverse what else would you like + + + align:start position:0% +of a B inverse what else would you like +to add about teaching + + align:start position:0% +to add about teaching + + + align:start position:0% +to add about teaching +18:06 linear algebra well with 1806 of + + align:start position:0% +18:06 linear algebra well with 1806 of + + + align:start position:0% +18:06 linear algebra well with 1806 of +course I'm just so a recently + + align:start position:0% +course I'm just so a recently + + + align:start position:0% +course I'm just so a recently +OpenCourseWare which i think was just + + align:start position:0% +OpenCourseWare which i think was just + + + align:start position:0% +OpenCourseWare which i think was just +such a great idea great idea for MIT + + align:start position:0% +such a great idea great idea for MIT + + + align:start position:0% +such a great idea great idea for MIT +great idea for a faculty so they did a + + align:start position:0% +great idea for a faculty so they did a + + + align:start position:0% +great idea for a faculty so they did a +count of the number of viewers in 1806 + + align:start position:0% +count of the number of viewers in 1806 + + + align:start position:0% +count of the number of viewers in 1806 +and it was ten million which was like + + align:start position:0% +and it was ten million which was like + + + align:start position:0% +and it was ten million which was like +poo I never expected and by + + align:start position:0% +poo I never expected and by + + + align:start position:0% +poo I never expected and by +do get nice really nice messages from + + align:start position:0% +do get nice really nice messages from + + + align:start position:0% +do get nice really nice messages from +all over the world and I reply to them + + align:start position:0% +all over the world and I reply to them + + + align:start position:0% +all over the world and I reply to them +far as I can sometimes they'll ask how + + align:start position:0% +far as I can sometimes they'll ask how + + + align:start position:0% +far as I can sometimes they'll ask how +how what what's a good way to learn math + + align:start position:0% +how what what's a good way to learn math + + + align:start position:0% +how what what's a good way to learn math +and I don't know if I have an answer for + + align:start position:0% +and I don't know if I have an answer for + + + align:start position:0% +and I don't know if I have an answer for +that but anyway I'm trying to be + + align:start position:0% +that but anyway I'm trying to be + + + align:start position:0% +that but anyway I'm trying to be +encouraging so yeah it's it's been + + align:start position:0% +encouraging so yeah it's it's been + + + align:start position:0% +encouraging so yeah it's it's been +wonderful yeah just having the video + + align:start position:0% +wonderful yeah just having the video + + + align:start position:0% +wonderful yeah just having the video +lectures available makes allows + + align:start position:0% +lectures available makes allows + + + align:start position:0% +lectures available makes allows +everybody to be in the class yeah so + + align:start position:0% +everybody to be in the class yeah so + + + align:start position:0% +everybody to be in the class yeah so +thank you all for joining the class + + align:start position:0% +thank you all for joining the class + + + align:start position:0% +thank you all for joining the class +thank you \ No newline at end of file diff --git a/85YISwhp7MQ.txt b/85YISwhp7MQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..c98bf7bac62cd09f04efefa931fed1bcff9c8dfd --- /dev/null +++ b/85YISwhp7MQ.txt @@ -0,0 +1,11392 @@ +align:start position:0% + +So so + + align:start position:0% +So so + + + align:start position:0% +So so +let's recall where we were last time. So + + align:start position:0% +let's recall where we were last time. So + + + align:start position:0% +let's recall where we were last time. So +we are trying to prove protection + + align:start position:0% +we are trying to prove protection + + + align:start position:0% +we are trying to prove protection +theorem. I guess I will state it again + + align:start position:0% +theorem. I guess I will state it again + + + align:start position:0% +theorem. I guess I will state it again +uh later. But uh last time we hopefully + + align:start position:0% +uh later. But uh last time we hopefully + + + align:start position:0% +uh later. But uh last time we hopefully +accepted the following fact as true. Uh + + align:start position:0% +accepted the following fact as true. Uh + + + align:start position:0% +accepted the following fact as true. Uh +okay. So maybe + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% +if + + + align:start position:0% +if +a subset of 01 + + align:start position:0% +a subset of 01 + + + align:start position:0% +a subset of 01 +is a okay so given s + + align:start position:0% + + + + align:start position:0% + + + align:start position:0% + + + align:start position:0% +there exist + + align:start position:0% +there exist + + + align:start position:0% +there exist +ea and epsilon positive depending on s + + align:start position:0% +ea and epsilon positive depending on s + + + align:start position:0% +ea and epsilon positive depending on s +and if we have a set which is a an S + + align:start position:0% +and if we have a set which is a an S + + + align:start position:0% +and if we have a set which is a an S +delta delta to the minus EA set + + align:start position:0% +delta delta to the minus EA set + + + align:start position:0% +delta delta to the minus EA set +then there exist a little A in the set + + align:start position:0% +then there exist a little A in the set + + + align:start position:0% +then there exist a little A in the set +such that the size of A plus little A a + + align:start position:0% +such that the size of A plus little A a + + + align:start position:0% +such that the size of A plus little A a +grows by delta to the minus epsilon + + align:start position:0% +grows by delta to the minus epsilon + + + align:start position:0% +grows by delta to the minus epsilon +compared to the size of A. + + align:start position:0% + + + + align:start position:0% + +So Larry pointed out okay so initially + + align:start position:0% +So Larry pointed out okay so initially + + + align:start position:0% +So Larry pointed out okay so initially +instead of this we have some polomial Q + + align:start position:0% +instead of this we have some polomial Q + + + align:start position:0% +instead of this we have some polomial Q +of A such as AA minus AA. So Larry + + align:start position:0% +of A such as AA minus AA. So Larry + + + align:start position:0% +of A such as AA minus AA. So Larry +pointed out to me that if you follow + + align:start position:0% +pointed out to me that if you follow + + + align:start position:0% +pointed out to me that if you follow +exactly what you did in the finite field + + align:start position:0% +exactly what you did in the finite field + + + align:start position:0% +exactly what you did in the finite field +setting to go from Q of A to this you + + align:start position:0% +setting to go from Q of A to this you + + + align:start position:0% +setting to go from Q of A to this you +need to use the non-conentration + + align:start position:0% +need to use the non-conentration + + + align:start position:0% +need to use the non-conentration +condition that we are trying to prove + + align:start position:0% +condition that we are trying to prove + + + align:start position:0% +condition that we are trying to prove +but it is possible to do it in a way + + align:start position:0% +but it is possible to do it in a way + + + align:start position:0% +but it is possible to do it in a way +which is not circular. So + + align:start position:0% +which is not circular. So + + + align:start position:0% +which is not circular. So +okay so I said I was not going to cover + + align:start position:0% +okay so I said I was not going to cover + + + align:start position:0% +okay so I said I was not going to cover +all of the details. So using pruning + + align:start position:0% +all of the details. So using pruning + + + align:start position:0% +all of the details. So using pruning +corusa so pruning corusa is the main + + align:start position:0% +corusa so pruning corusa is the main + + + align:start position:0% +corusa so pruning corusa is the main +tool and switchable double counting one + + align:start position:0% +tool and switchable double counting one + + + align:start position:0% +tool and switchable double counting one +can really improve this without using + + align:start position:0% +can really improve this without using + + + align:start position:0% +can really improve this without using +something that we haven't proved yet + + align:start position:0% +something that we haven't proved yet + + + align:start position:0% +something that we haven't proved yet +okay and the goal is to improve this by + + align:start position:0% +okay and the goal is to improve this by + + + align:start position:0% +okay and the goal is to improve this by +showing that a plus a satisfies a better + + align:start position:0% +showing that a plus a satisfies a better + + + align:start position:0% +showing that a plus a satisfies a better +non concentration condition that will + + align:start position:0% +non concentration condition that will + + + align:start position:0% +non concentration condition that will +allow us to iterate. So the goal is to + + align:start position:0% +allow us to iterate. So the goal is to + + + align:start position:0% +allow us to iterate. So the goal is to +show that a plus a a actually contains + + align:start position:0% +show that a plus a a actually contains + + + align:start position:0% +show that a plus a a actually contains +because + + align:start position:0% +because + + + align:start position:0% +because +it is not true that it always is but it + + align:start position:0% +it is not true that it always is but it + + + align:start position:0% +it is not true that it always is but it +contains + + align:start position:0% +contains + + + align:start position:0% +contains +a delta s plus epsilon + + align:start position:0% +a delta s plus epsilon + + + align:start position:0% +a delta s plus epsilon +delta to the minus + + align:start position:0% +delta to the minus + + + align:start position:0% +delta to the minus +maybe let's call it prime + + align:start position:0% +maybe let's call it prime + + + align:start position:0% +maybe let's call it prime +um set. + + align:start position:0% +um set. + + + align:start position:0% +um set. +So the can get worse when one iterates + + align:start position:0% +So the can get worse when one iterates + + + align:start position:0% +So the can get worse when one iterates +but one iterates finitely many times. So + + align:start position:0% +but one iterates finitely many times. So + + + align:start position:0% +but one iterates finitely many times. So +this is not serious. + + align:start position:0% +this is not serious. + + + align:start position:0% +this is not serious. +Okay. Um, okay. Maybe for a different So + + align:start position:0% +Okay. Um, okay. Maybe for a different So + + + align:start position:0% +Okay. Um, okay. Maybe for a different So +the epsilon is also going to change. + + align:start position:0% + + + + align:start position:0% + +Okay. So, um, + + align:start position:0% +Okay. So, um, + + + align:start position:0% +Okay. So, um, +so suppose + + align:start position:0% +so suppose + + + align:start position:0% +so suppose +so I'm basically going back to what I + + align:start position:0% +so I'm basically going back to what I + + + align:start position:0% +so I'm basically going back to what I +did at the end of last time, but I was + + align:start position:0% +did at the end of last time, but I was + + + align:start position:0% +did at the end of last time, but I was +rushing a bit. So I'm going to be a bit + + align:start position:0% +rushing a bit. So I'm going to be a bit + + + align:start position:0% +rushing a bit. So I'm going to be a bit +more precise hopefully. Suppose that a + + align:start position:0% +more precise hopefully. Suppose that a + + + align:start position:0% +more precise hopefully. Suppose that a +is a delta s delta to the minus ea squar + + align:start position:0% +is a delta s delta to the minus ea squar + + + align:start position:0% +is a delta s delta to the minus ea squar +set. + + align:start position:0% + + + + align:start position:0% + +Well in particular it is an s delta + + align:start position:0% +Well in particular it is an s delta + + + align:start position:0% +Well in particular it is an s delta +delta to the minus + + align:start position:0% + + + + align:start position:0% + +so I guess the delta goes first. Um in + + align:start position:0% +so I guess the delta goes first. Um in + + + align:start position:0% +so I guess the delta goes first. Um in +particular it is it is a delta s delta + + align:start position:0% +particular it is it is a delta s delta + + + align:start position:0% +particular it is it is a delta s delta +to the minus ita set because it is a + + align:start position:0% +to the minus ita set because it is a + + + align:start position:0% +to the minus ita set because it is a +very small number. But why did I square + + align:start position:0% +very small number. But why did I square + + + align:start position:0% +very small number. But why did I square +it? Because um then + + align:start position:0% +it? Because um then + + + align:start position:0% +it? Because um then +it is okay. And as we saw last time, if + + align:start position:0% +it is okay. And as we saw last time, if + + + align:start position:0% +it is okay. And as we saw last time, if +we take a subset of a which is uniform, + + align:start position:0% +we take a subset of a which is uniform, + + + align:start position:0% +we take a subset of a which is uniform, +delta m uniform for some good choice of + + align:start position:0% +delta m uniform for some good choice of + + + align:start position:0% +delta m uniform for some good choice of +delta, delta will have to be chosen + + align:start position:0% +delta, delta will have to be chosen + + + align:start position:0% +delta, delta will have to be chosen +small enough in terms of EA but nothing + + align:start position:0% +small enough in terms of EA but nothing + + + align:start position:0% +small enough in terms of EA but nothing +else. + + align:start position:0% +else. + + + align:start position:0% +else. +uh then so we may assume + + align:start position:0% + + + + align:start position:0% + +let's call it delta uniform + + align:start position:0% + + + + align:start position:0% + +or delta + + align:start position:0% +or delta + + + align:start position:0% +or delta +depends on ea so that basically this + + align:start position:0% +depends on ea so that basically this + + + align:start position:0% +depends on ea so that basically this +doesn't change maybe one has to multiply + + align:start position:0% +doesn't change maybe one has to multiply + + + align:start position:0% +doesn't change maybe one has to multiply +by two but essentially doesn't change + + align:start position:0% +by two but essentially doesn't change + + + align:start position:0% +by two but essentially doesn't change +well then uh this uh set because it's + + align:start position:0% +well then uh this uh set because it's + + + align:start position:0% +well then uh this uh set because it's +uniform now is also a row s + + align:start position:0% +uniform now is also a row s + + + align:start position:0% +uniform now is also a row s +delta to the minus ea square + + align:start position:0% +delta to the minus ea square + + + align:start position:0% +delta to the minus ea square +for every row + + align:start position:0% + + + + align:start position:0% + +and then this implies that it is also a + + align:start position:0% +and then this implies that it is also a + + + align:start position:0% +and then this implies that it is also a +row s row to the minus ea. So the + + align:start position:0% +row s row to the minus ea. So the + + + align:start position:0% +row s row to the minus ea. So the +problem here is that now we have row + + align:start position:0% +problem here is that now we have row + + + align:start position:0% +problem here is that now we have row +here but we still have delta here but we + + align:start position:0% +here but we still have delta here but we + + + align:start position:0% +here but we still have delta here but we +replace it by it squared so that so that + + align:start position:0% +replace it by it squared so that so that + + + align:start position:0% +replace it by it squared so that so that +we can have also row here + + align:start position:0% +we can have also row here + + + align:start position:0% +we can have also row here +and this will be for every row + + align:start position:0% +and this will be for every row + + + align:start position:0% +and this will be for every row +between delta and delta to the ea + + align:start position:0% + + + + align:start position:0% + +right because we started with delta to + + align:start position:0% +right because we started with delta to + + + align:start position:0% +right because we started with delta to +the minus ea squ + + align:start position:0% + + + + align:start position:0% + +okay we don't go all the way to one but + + align:start position:0% +okay we don't go all the way to one but + + + align:start position:0% +okay we don't go all the way to one but +almost it is very very small. So morally + + align:start position:0% +almost it is very very small. So morally + + + align:start position:0% +almost it is very very small. So morally +this is almost one. + + align:start position:0% + + + + align:start position:0% + +So from here to here we use the + + align:start position:0% +So from here to here we use the + + + align:start position:0% +So from here to here we use the +uniformity. So one consequence of + + align:start position:0% +uniformity. So one consequence of + + + align:start position:0% +uniformity. So one consequence of +uniformity that uh I explained last time + + align:start position:0% +uniformity that uh I explained last time + + + align:start position:0% +uniformity that uh I explained last time +is that a uniform delta set is also a + + align:start position:0% +is that a uniform delta set is also a + + + align:start position:0% +is that a uniform delta set is also a +row set for every row. And this is just + + align:start position:0% + + + + align:start position:0% + +trivial inequality assume that row is at + + align:start position:0% +trivial inequality assume that row is at + + + align:start position:0% +trivial inequality assume that row is at +most delta to the ea. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Okay. So this in this means that we can + + align:start position:0% +Okay. So this in this means that we can + + + align:start position:0% +Okay. So this in this means that we can +apply what we already know for every + + align:start position:0% +apply what we already know for every + + + align:start position:0% +apply what we already know for every +scale row between delta and delta 2 + + align:start position:0% +scale row between delta and delta 2 + + + align:start position:0% +scale row between delta and delta 2 +theta because it satisfies the + + align:start position:0% +theta because it satisfies the + + + align:start position:0% +theta because it satisfies the +assumptions. + + align:start position:0% + + + + align:start position:0% + +And another thing that I explained last + + align:start position:0% +And another thing that I explained last + + + align:start position:0% +And another thing that I explained last +time is that even though a priority we + + align:start position:0% +time is that even though a priority we + + + align:start position:0% +time is that even though a priority we +only know that there exists an a so that + + align:start position:0% +only know that there exists an a so that + + + align:start position:0% +only know that there exists an a so that +a plus little aa grows by applying that + + align:start position:0% +a plus little aa grows by applying that + + + align:start position:0% +a plus little aa grows by applying that +to the set of exceptions we get that + + align:start position:0% +to the set of exceptions we get that + + + align:start position:0% +to the set of exceptions we get that +this is true for almost every a in a + + align:start position:0% +this is true for almost every a in a + + + align:start position:0% +this is true for almost every a in a +strong sense. So if you put all of this + + align:start position:0% +strong sense. So if you put all of this + + + align:start position:0% +strong sense. So if you put all of this +together, + + align:start position:0% +together, + + + align:start position:0% +together, +what we get is that + + align:start position:0% + + + + align:start position:0% + +okay so maybe let's recall what I just + + align:start position:0% +okay so maybe let's recall what I just + + + align:start position:0% +okay so maybe let's recall what I just +said. So in fact um + + align:start position:0% +said. So in fact um + + + align:start position:0% +said. So in fact um +the set of a + + align:start position:0% +the set of a + + + align:start position:0% +the set of a +okay so let's work with some finite set + + align:start position:0% +okay so let's work with some finite set + + + align:start position:0% +okay so let's work with some finite set +of rows which are powers of delta again. + + align:start position:0% +of rows which are powers of delta again. + + + align:start position:0% +of rows which are powers of delta again. +So we have delta delta square + + align:start position:0% +So we have delta delta square + + + align:start position:0% +So we have delta delta square +up to delta to some + + align:start position:0% +up to delta to some + + + align:start position:0% +up to delta to some +maybe m prime. So that this is equal to + + align:start position:0% +maybe m prime. So that this is equal to + + + align:start position:0% +maybe m prime. So that this is equal to +delta to the + + align:start position:0% +delta to the + + + align:start position:0% +delta to the +recall that little delta is delta to the + + align:start position:0% +recall that little delta is delta to the + + + align:start position:0% +recall that little delta is delta to the +m. So m prime is less than m but it is + + align:start position:0% +m. So m prime is less than m but it is + + + align:start position:0% +m. So m prime is less than m but it is +close to m. + + align:start position:0% + + + + align:start position:0% + +And again this is a + + align:start position:0% +And again this is a + + + align:start position:0% +And again this is a +finite set of scales. Well, not really + + align:start position:0% +finite set of scales. Well, not really + + + align:start position:0% +finite set of scales. Well, not really +finite because okay this it is finite + + align:start position:0% +finite because okay this it is finite + + + align:start position:0% +finite because okay this it is finite +but it grows with delta but it grows + + align:start position:0% +but it grows with delta but it grows + + + align:start position:0% +but it grows with delta but it grows +logarithmically with delta. So m is + + align:start position:0% +logarithmically with delta. So m is + + + align:start position:0% +logarithmically with delta. So m is +logarithm + + align:start position:0% +logarithm + + + align:start position:0% +logarithm +of little delta in base + + align:start position:0% +of little delta in base + + + align:start position:0% +of little delta in base +delta. Big delta is fixed. So it's it's + + align:start position:0% +delta. Big delta is fixed. So it's it's + + + align:start position:0% +delta. Big delta is fixed. So it's it's +logarithmic in delta and m prime is + + align:start position:0% +logarithmic in delta and m prime is + + + align:start position:0% +logarithmic in delta and m prime is +smaller. So it's also logarithmic in + + align:start position:0% +smaller. So it's also logarithmic in + + + align:start position:0% +smaller. So it's also logarithmic in +delta. Okay. So uh for each row + + align:start position:0% + + + + align:start position:0% + +we know that the set of A's so that A + + align:start position:0% +we know that the set of A's so that A + + + align:start position:0% +we know that the set of A's so that A +plus row A doesn't grow sorry little A + + align:start position:0% +plus row A doesn't grow sorry little A + + + align:start position:0% +plus row A doesn't grow sorry little A +but measurement scale row doesn't grow + + align:start position:0% +but measurement scale row doesn't grow + + + align:start position:0% +but measurement scale row doesn't grow +by row to the minus epsilon + + align:start position:0% + + + + align:start position:0% + +has size at most row to the eater + + align:start position:0% +has size at most row to the eater + + + align:start position:0% +has size at most row to the eater +times the size of a. + + align:start position:0% + + + + align:start position:0% + +And why is this true? Because + + align:start position:0% +And why is this true? Because + + + align:start position:0% +And why is this true? Because +uh if + + align:start position:0% + + + + align:start position:0% + +this was not true then we could apply + + align:start position:0% +this was not true then we could apply + + + align:start position:0% +this was not true then we could apply +the statement above to the scale row + + align:start position:0% +the statement above to the scale row + + + align:start position:0% +the statement above to the scale row +to the set of exceptions to this set and + + align:start position:0% +to the set of exceptions to this set and + + + align:start position:0% +to the set of exceptions to this set and +get the contradiction. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +Okay. And this is very small in terms of + + align:start position:0% +Okay. And this is very small in terms of + + + align:start position:0% +Okay. And this is very small in terms of +delta. So row to the EA is at most delta + + align:start position:0% +delta. So row to the EA is at most delta + + + align:start position:0% +delta. So row to the EA is at most delta +to the EA squar + + align:start position:0% + + + + align:start position:0% + +sorry here. + + align:start position:0% +sorry here. + + + align:start position:0% +sorry here. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Okay. So here we are counting a set of + + align:start position:0% +Okay. So here we are counting a set of + + + align:start position:0% +Okay. So here we are counting a set of +A's. So the only way in which we can + + align:start position:0% +A's. So the only way in which we can + + + align:start position:0% +A's. So the only way in which we can +really count a set of A's is by + + align:start position:0% +really count a set of A's is by + + + align:start position:0% +really count a set of A's is by +measuring it at some scale. otherwise + + align:start position:0% +measuring it at some scale. otherwise + + + align:start position:0% +measuring it at some scale. otherwise +could be infinite. So we always have to + + align:start position:0% +could be infinite. So we always have to + + + align:start position:0% +could be infinite. So we always have to +choose a scale. Um + + align:start position:0% +choose a scale. Um + + + align:start position:0% +choose a scale. Um +so scale row okay row to the EA is at + + align:start position:0% +so scale row okay row to the EA is at + + + align:start position:0% +so scale row okay row to the EA is at +most delta to the squared + + align:start position:0% + + + + align:start position:0% + +and this means that um + + align:start position:0% + + + + align:start position:0% + +sorry this is wrong. + + align:start position:0% +sorry this is wrong. + + + align:start position:0% +sorry this is wrong. +Let's go back and fix it. So delta is is + + align:start position:0% +Let's go back and fix it. So delta is is + + + align:start position:0% +Let's go back and fix it. So delta is is +is too large. So delta is a constant. So + + align:start position:0% +is too large. So delta is a constant. So + + + align:start position:0% +is too large. So delta is a constant. So +I want to be away from one. Uh not away + + align:start position:0% +I want to be away from one. Uh not away + + + align:start position:0% +I want to be away from one. Uh not away +from zero but away from one. So the rows + + align:start position:0% +from zero but away from one. So the rows + + + align:start position:0% +from zero but away from one. So the rows +that we consider are delta to the m + + align:start position:0% +that we consider are delta to the m + + + align:start position:0% +that we consider are delta to the m +delta to the which is little delta delta + + align:start position:0% +delta to the which is little delta delta + + + align:start position:0% +delta to the which is little delta delta +to the m minus one. And then we stop at + + align:start position:0% +to the m minus one. And then we stop at + + + align:start position:0% +to the m minus one. And then we stop at +delta to the ea. + + align:start position:0% + + + + align:start position:0% + +Sorry about that. + + align:start position:0% + + + + align:start position:0% + +Okay. because we are only looking at + + align:start position:0% +Okay. because we are only looking at + + + align:start position:0% +Okay. because we are only looking at +logarithmically many um values of delta. + + align:start position:0% +logarithmically many um values of delta. + + + align:start position:0% +logarithmically many um values of delta. +Okay, one has to work a little bit more + + align:start position:0% +Okay, one has to work a little bit more + + + align:start position:0% +Okay, one has to work a little bit more +because here we are measuring things + + align:start position:0% +because here we are measuring things + + + align:start position:0% +because here we are measuring things +that scale row but uh row is far away + + align:start position:0% +that scale row but uh row is far away + + + align:start position:0% +that scale row but uh row is far away +from one + + align:start position:0% +from one + + + align:start position:0% +from one +and there are only logarithmically many + + align:start position:0% +and there are only logarithmically many + + + align:start position:0% +and there are only logarithmically many +values of row. So putting all together + + align:start position:0% +values of row. So putting all together + + + align:start position:0% +values of row. So putting all together +what we get is that + + align:start position:0% + + + + align:start position:0% + +for all aside + + align:start position:0% + + + + align:start position:0% + +of a small set. + + align:start position:0% +of a small set. + + + align:start position:0% +of a small set. +Maybe something like a set of size + + align:start position:0% + + + + align:start position:0% + +delta to the ea + + align:start position:0% + + + + align:start position:0% + +I don't know cubed times the size of a + + align:start position:0% + + + + align:start position:0% + +we get that a plus little a grows for + + align:start position:0% +we get that a plus little a grows for + + + align:start position:0% +we get that a plus little a grows for +every scale in this family. + + align:start position:0% + + + + align:start position:0% + +Okay. And now it looks like we are + + align:start position:0% +Okay. And now it looks like we are + + + align:start position:0% +Okay. And now it looks like we are +getting close because well we want to + + align:start position:0% +getting close because well we want to + + + align:start position:0% +getting close because well we want to +show that this contains + + align:start position:0% + + + + align:start position:0% + +a delta + + align:start position:0% +a delta + + + align:start position:0% +a delta +s plus epsilon something set and a + + align:start position:0% +s plus epsilon something set and a + + + align:start position:0% +s plus epsilon something set and a +necessary condition is that we have + + align:start position:0% +necessary condition is that we have + + + align:start position:0% +necessary condition is that we have +growth at every scale. + + align:start position:0% +growth at every scale. + + + align:start position:0% +growth at every scale. +So if you have a set with that, so if + + align:start position:0% +So if you have a set with that, so if + + + align:start position:0% +So if you have a set with that, so if +you have a + + align:start position:0% +you have a + + + align:start position:0% +you have a +delta s plus epsilon something set, then + + align:start position:0% +delta s plus epsilon something set, then + + + align:start position:0% +delta s plus epsilon something set, then +this will be true. + + align:start position:0% +this will be true. + + + align:start position:0% +this will be true. +And if we knew that this set is uniform, + + align:start position:0% +And if we knew that this set is uniform, + + + align:start position:0% +And if we knew that this set is uniform, +we would be done because for a uniform + + align:start position:0% +we would be done because for a uniform + + + align:start position:0% +we would be done because for a uniform +set, the condition of growing at every + + align:start position:0% +set, the condition of growing at every + + + align:start position:0% +set, the condition of growing at every +scale is necessary and sufficient. + + align:start position:0% +scale is necessary and sufficient. + + + align:start position:0% +scale is necessary and sufficient. +But we don't know that this set is + + align:start position:0% +But we don't know that this set is + + + align:start position:0% +But we don't know that this set is +uniform. + + align:start position:0% +uniform. + + + align:start position:0% +uniform. +So we are not done yet. So we are + + align:start position:0% +So we are not done yet. So we are + + + align:start position:0% +So we are not done yet. So we are +getting closer, but we are not done yet. + + align:start position:0% +getting closer, but we are not done yet. + + + align:start position:0% +getting closer, but we are not done yet. +Any questions? So, this is more or less + + align:start position:0% +Any questions? So, this is more or less + + + align:start position:0% +Any questions? So, this is more or less +where we were last time. + + align:start position:0% +where we were last time. + + + align:start position:0% +where we were last time. +Okay. So, in order to be able to finish, + + align:start position:0% +Okay. So, in order to be able to finish, + + + align:start position:0% +Okay. So, in order to be able to finish, +we still have to work a bit and uh there + + align:start position:0% +we still have to work a bit and uh there + + + align:start position:0% +we still have to work a bit and uh there +was a claim that there was explaining + + align:start position:0% +was a claim that there was explaining + + + align:start position:0% +was a claim that there was explaining +last time that we can improve this. So + + align:start position:0% +last time that we can improve this. So + + + align:start position:0% +last time that we can improve this. So +here we are projecting a * a. So this is + + align:start position:0% +here we are projecting a * a. So this is + + + align:start position:0% +here we are projecting a * a. So this is +pi a of a * a. So we can improve this to + + align:start position:0% +pi a of a * a. So we can improve this to + + + align:start position:0% +pi a of a * a. So we can improve this to +project an arbitrary dense subset of a * + + align:start position:0% +project an arbitrary dense subset of a * + + + align:start position:0% +project an arbitrary dense subset of a * +a. So claim + + align:start position:0% +a. So claim + + + align:start position:0% +a. So claim +uh if + + align:start position:0% +uh if + + + align:start position:0% +uh if +g is contained in a * a and it has size + + align:start position:0% +g is contained in a * a and it has size + + + align:start position:0% +g is contained in a * a and it has size +at scale delta let's say delta to the + + align:start position:0% +at scale delta let's say delta to the + + + align:start position:0% +at scale delta let's say delta to the +square or something like this + + align:start position:0% +square or something like this + + + align:start position:0% +square or something like this +relative to a * a then + + align:start position:0% + + + + align:start position:0% + +pa of g + + align:start position:0% +pa of g + + + align:start position:0% +pa of g +already grows + + align:start position:0% +already grows + + + align:start position:0% +already grows +and in fact we this we will also want to + + align:start position:0% +and in fact we this we will also want to + + + align:start position:0% +and in fact we this we will also want to +apply + + align:start position:0% + + + + align:start position:0% + +at many scales or maybe not. We'll see. + + align:start position:0% +at many scales or maybe not. We'll see. + + + align:start position:0% +at many scales or maybe not. We'll see. +Okay, let's start with scale delta. Then + + align:start position:0% +Okay, let's start with scale delta. Then + + + align:start position:0% +Okay, let's start with scale delta. Then +we'll see what we actually need. Uh then + + align:start position:0% +we'll see what we actually need. Uh then + + + align:start position:0% +we'll see what we actually need. Uh then +this already grows let's say by epsilon + + align:start position:0% +this already grows let's say by epsilon + + + align:start position:0% +this already grows let's say by epsilon +/ two. + + align:start position:0% + + + + align:start position:0% + +Okay. And I guess at this stage uh we + + align:start position:0% +Okay. And I guess at this stage uh we + + + align:start position:0% +Okay. And I guess at this stage uh we +claim that there exists such an A. + + align:start position:0% +claim that there exists such an A. + + + align:start position:0% +claim that there exists such an A. +But once again, if there exist an A, + + align:start position:0% +But once again, if there exist an A, + + + align:start position:0% +But once again, if there exist an A, +then it is true for nearly all A by + + align:start position:0% +then it is true for nearly all A by + + + align:start position:0% +then it is true for nearly all A by +applying the fact that there exists an A + + align:start position:0% +applying the fact that there exists an A + + + align:start position:0% +applying the fact that there exists an A +to the exceptional set. So we can play + + align:start position:0% +to the exceptional set. So we can play + + + align:start position:0% +to the exceptional set. So we can play +this game as many times as we want and + + align:start position:0% +this game as many times as we want and + + + align:start position:0% +this game as many times as we want and +we want to play it many times. + + align:start position:0% +we want to play it many times. + + + align:start position:0% +we want to play it many times. +Okay. So uh last time we were in the + + align:start position:0% +Okay. So uh last time we were in the + + + align:start position:0% +Okay. So uh last time we were in the +middle of proving this. So let's start + + align:start position:0% +middle of proving this. So let's start + + + align:start position:0% +middle of proving this. So let's start +the game. Uh assume that one is in a + + align:start position:0% +the game. Uh assume that one is in a + + + align:start position:0% +the game. Uh assume that one is in a +this is just tool to okay just for + + align:start position:0% +this is just tool to okay just for + + + align:start position:0% +this is just tool to okay just for +notation and simplicity it's not not + + align:start position:0% +notation and simplicity it's not not + + + align:start position:0% +notation and simplicity it's not not +important. + + align:start position:0% +important. + + + align:start position:0% +important. +Well, if a equals 1 works, + + align:start position:0% +Well, if a equals 1 works, + + + align:start position:0% +Well, if a equals 1 works, +we are done because we are trying to + + align:start position:0% +we are done because we are trying to + + + align:start position:0% +we are done because we are trying to +show that some some element of a works. + + align:start position:0% +show that some some element of a works. + + + align:start position:0% +show that some some element of a works. +So, if the element one happens to work, + + align:start position:0% +So, if the element one happens to work, + + + align:start position:0% +So, if the element one happens to work, +we are happy. + + align:start position:0% +we are happy. + + + align:start position:0% +we are happy. +Otherwise, + + align:start position:0% +Otherwise, + + + align:start position:0% +Otherwise, +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +one doesn't work. And the fact that one + + align:start position:0% +one doesn't work. And the fact that one + + + align:start position:0% +one doesn't work. And the fact that one +doesn't work means that there exists G + + align:start position:0% +doesn't work means that there exists G + + + align:start position:0% +doesn't work means that there exists G +which is dense in a * A + + align:start position:0% +which is dense in a * A + + + align:start position:0% +which is dense in a * A +[Applause] + + align:start position:0% + + + + align:start position:0% + +and such that pi 1 of G doesn't grow too + + align:start position:0% +and such that pi 1 of G doesn't grow too + + + align:start position:0% +and such that pi 1 of G doesn't grow too +much. + + align:start position:0% + + + + align:start position:0% + +And this okay the f so all of these + + align:start position:0% +And this okay the f so all of these + + + align:start position:0% +And this okay the f so all of these +together are exactly the assumptions of + + align:start position:0% +together are exactly the assumptions of + + + align:start position:0% +together are exactly the assumptions of +alumericic hours or rather the delta + + align:start position:0% +alumericic hours or rather the delta + + + align:start position:0% +alumericic hours or rather the delta +covering number of Alexic hours but as I + + align:start position:0% +covering number of Alexic hours but as I + + + align:start position:0% +covering number of Alexic hours but as I +explained a couple of lectures ago + + align:start position:0% +explained a couple of lectures ago + + + align:start position:0% +explained a couple of lectures ago +valuic hours works exactly the same for + + align:start position:0% +valuic hours works exactly the same for + + + align:start position:0% +valuic hours works exactly the same for +delta covering numbers. + + align:start position:0% + + + + align:start position:0% + +So maybe let's recall + + align:start position:0% + + + + align:start position:0% + +the hours for delta covering numbers. Um + + align:start position:0% + + + + align:start position:0% + +if + + align:start position:0% + + + + align:start position:0% + +uh a a scale delta has size n + + align:start position:0% +uh a a scale delta has size n + + + align:start position:0% +uh a a scale delta has size n +and + + align:start position:0% +and + + + align:start position:0% +and +there exists g contained in a * a + + align:start position:0% + + + + align:start position:0% + +such that the size of g at scale delta + + align:start position:0% +such that the size of g at scale delta + + + align:start position:0% +such that the size of g at scale delta +is at least 1 / k times the size of a + + align:start position:0% +is at least 1 / k times the size of a + + + align:start position:0% +is at least 1 / k times the size of a +plus a at scale delta + + align:start position:0% +plus a at scale delta + + + align:start position:0% +plus a at scale delta +And if we project in the direction one + + align:start position:0% +And if we project in the direction one + + + align:start position:0% +And if we project in the direction one +the set g + + align:start position:0% +the set g + + + align:start position:0% +the set g +uh this doesn't grow a lot compared to + + align:start position:0% +uh this doesn't grow a lot compared to + + + align:start position:0% +uh this doesn't grow a lot compared to +the size of a. + + align:start position:0% +the size of a. + + + align:start position:0% +the size of a. +If all of this is true then there exists + + align:start position:0% +If all of this is true then there exists + + + align:start position:0% +If all of this is true then there exists +a set a prime contained in a which is + + align:start position:0% +a set a prime contained in a which is + + + align:start position:0% +a set a prime contained in a which is +fairly dense. So the size of a at scale + + align:start position:0% +fairly dense. So the size of a at scale + + + align:start position:0% +fairly dense. So the size of a at scale +delta is at least k to minus a constant + + align:start position:0% +delta is at least k to minus a constant + + + align:start position:0% +delta is at least k to minus a constant +times the size of a + + align:start position:0% +times the size of a + + + align:start position:0% +times the size of a +and a prime has a small subset. + + align:start position:0% + + + + align:start position:0% + +The doubling constant for a prime is at + + align:start position:0% +The doubling constant for a prime is at + + + align:start position:0% +The doubling constant for a prime is at +most k to a power to to a constant power + + align:start position:0% +most k to a power to to a constant power + + + align:start position:0% +most k to a power to to a constant power +times the size of a prime. + + align:start position:0% + + + + align:start position:0% + +Okay, this is valuic hours. + + align:start position:0% +Okay, this is valuic hours. + + + align:start position:0% +Okay, this is valuic hours. +Well, here we can take well n is just + + align:start position:0% +Well, here we can take well n is just + + + align:start position:0% +Well, here we can take well n is just +the delta covering number of a and we + + align:start position:0% +the delta covering number of a and we + + + align:start position:0% +the delta covering number of a and we +can take k to be the minimum between ea + + align:start position:0% +can take k to be the minimum between ea + + + align:start position:0% +can take k to be the minimum between ea +square + + align:start position:0% +square + + + align:start position:0% +square +delta to the minus ea square and delta + + align:start position:0% +delta to the minus ea square and delta + + + align:start position:0% +delta to the minus ea square and delta +to the minus epsilon / two which is + + align:start position:0% +to the minus epsilon / two which is + + + align:start position:0% +to the minus epsilon / two which is +really delta to the minus ea square. You + + align:start position:0% +really delta to the minus ea square. You + + + align:start position:0% +really delta to the minus ea square. You +should imagine that is smaller than + + align:start position:0% +should imagine that is smaller than + + + align:start position:0% +should imagine that is smaller than +epsilon even before squaring. + + align:start position:0% +epsilon even before squaring. + + + align:start position:0% +epsilon even before squaring. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Okay. So we apply maluic hours + + align:start position:0% + + + + align:start position:0% + +and let a prime + + align:start position:0% + + + + align:start position:0% + +be the corresponding set. + + align:start position:0% + + + + align:start position:0% + +Okay. And then uh + + align:start position:0% +Okay. And then uh + + + align:start position:0% +Okay. And then uh +a prime is dense in a + + align:start position:0% + + + + align:start position:0% + +and has more subset. + + align:start position:0% + + + + align:start position:0% + +Okay. So, A prime is a dense subset of + + align:start position:0% +Okay. So, A prime is a dense subset of + + + align:start position:0% +Okay. So, A prime is a dense subset of +A. + + align:start position:0% +A. + + + align:start position:0% +A. +A is a delta S something set. So, A + + align:start position:0% +A is a delta S something set. So, A + + + align:start position:0% +A is a delta S something set. So, A +prime is also a delta S something set + + align:start position:0% +prime is also a delta S something set + + + align:start position:0% +prime is also a delta S something set +because we saw that subsets of delta S + + align:start position:0% +because we saw that subsets of delta S + + + align:start position:0% +because we saw that subsets of delta S +something sets are delta S something + + align:start position:0% +something sets are delta S something + + + align:start position:0% +something sets are delta S something +sets where the constant. So basically we + + align:start position:0% +sets where the constant. So basically we + + + align:start position:0% +sets where the constant. So basically we +have to multiply the constant by this + + align:start position:0% +have to multiply the constant by this + + + align:start position:0% +have to multiply the constant by this +but a was a delta s delta to the epsilon + + align:start position:0% +but a was a delta s delta to the epsilon + + + align:start position:0% +but a was a delta s delta to the epsilon +square set. So this is still a delta s + + align:start position:0% +square set. So this is still a delta s + + + align:start position:0% +square set. So this is still a delta s +delta to the minus o of epsilon square + + align:start position:0% +delta to the minus o of epsilon square + + + align:start position:0% +delta to the minus o of epsilon square +set. + + align:start position:0% +set. + + + align:start position:0% +set. +So we can apply what we know to a prime. + + align:start position:0% +So we can apply what we know to a prime. + + + align:start position:0% +So we can apply what we know to a prime. +So a prime is a delta s delta to the + + align:start position:0% +So a prime is a delta s delta to the + + + align:start position:0% +So a prime is a delta s delta to the +minus o of it square set. + + align:start position:0% +minus o of it square set. + + + align:start position:0% +minus o of it square set. +So there exists a in a prime in a prime + + align:start position:0% +So there exists a in a prime in a prime + + + align:start position:0% +So there exists a in a prime in a prime +sorry such that a prime plus a a prime + + align:start position:0% +sorry such that a prime plus a a prime + + + align:start position:0% +sorry such that a prime plus a a prime +grows + + align:start position:0% + + + + align:start position:0% + +by applying the fact from the beginning + + align:start position:0% +by applying the fact from the beginning + + + align:start position:0% +by applying the fact from the beginning +to a prime. It still satisfies the + + align:start position:0% +to a prime. It still satisfies the + + + align:start position:0% +to a prime. It still satisfies the +assumptions. We have lost a constant + + align:start position:0% +assumptions. We have lost a constant + + + align:start position:0% +assumptions. We have lost a constant +here but this is harmless. + + align:start position:0% +here but this is harmless. + + + align:start position:0% +here but this is harmless. +Any + + align:start position:0% + + + + align:start position:0% + +questions so far? + + align:start position:0% + + + + align:start position:0% + +Okay. And now we apply something that + + align:start position:0% +Okay. And now we apply something that + + + align:start position:0% +Okay. And now we apply something that +you've seen in the finite field setting. + + align:start position:0% +you've seen in the finite field setting. + + + align:start position:0% +you've seen in the finite field setting. +And again, it works. This works exactly + + align:start position:0% +And again, it works. This works exactly + + + align:start position:0% +And again, it works. This works exactly +in the same way for delta covering sets. + + align:start position:0% +in the same way for delta covering sets. + + + align:start position:0% +in the same way for delta covering sets. +What you saw in the finite field setting + + align:start position:0% +What you saw in the finite field setting + + + align:start position:0% +What you saw in the finite field setting +is that if you have a set with a small + + align:start position:0% +is that if you have a set with a small + + + align:start position:0% +is that if you have a set with a small +sums set, + + align:start position:0% +sums set, + + + align:start position:0% +sums set, +so small pi 1 projection and large pi a + + align:start position:0% +so small pi 1 projection and large pi a + + + align:start position:0% +so small pi 1 projection and large pi a +projection, + + align:start position:0% +projection, + + + align:start position:0% +projection, +then in fact the pi projection remains + + align:start position:0% +then in fact the pi projection remains + + + align:start position:0% +then in fact the pi projection remains +large if we pass to a dense subset of a + + align:start position:0% +large if we pass to a dense subset of a + + + align:start position:0% +large if we pass to a dense subset of a +prime time n prime. + + align:start position:0% +prime time n prime. + + + align:start position:0% +prime time n prime. +Okay, so this is another recall from the + + align:start position:0% +Okay, so this is another recall from the + + + align:start position:0% +Okay, so this is another recall from the +finite field story. + + align:start position:0% + + + + align:start position:0% + +If a prime plus a prime let's say again + + align:start position:0% +If a prime plus a prime let's say again + + + align:start position:0% +If a prime plus a prime let's say again +it goes by at most k + + align:start position:0% +it goes by at most k + + + align:start position:0% +it goes by at most k +and a prime plus little a prime + + align:start position:0% +and a prime plus little a prime + + + align:start position:0% +and a prime plus little a prime +let's say + + align:start position:0% +let's say + + + align:start position:0% +let's say +so a prime has small doubling but if you + + align:start position:0% +so a prime has small doubling but if you + + + align:start position:0% +so a prime has small doubling but if you +apply projection by a it grows by + + align:start position:0% +apply projection by a it grows by + + + align:start position:0% +apply projection by a it grows by +something + + align:start position:0% +something + + + align:start position:0% +something +then in fact this implies that for every + + align:start position:0% +then in fact this implies that for every + + + align:start position:0% +then in fact this implies that for every +g in + + align:start position:0% +g in + + + align:start position:0% +g in +a prime * a prime which is dense + + align:start position:0% + + + + align:start position:0% + +let's say dense with threshold 1 / k + + align:start position:0% + + + + align:start position:0% + +everything measured with delta covering + + align:start position:0% +everything measured with delta covering + + + align:start position:0% +everything measured with delta covering +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +the projection is still large + + align:start position:0% + + + + align:start position:0% + +and I think it's K to minus some + + align:start position:0% +and I think it's K to minus some + + + align:start position:0% +and I think it's K to minus some +constant and DL basically survives. + + align:start position:0% + + + + align:start position:0% + +Does this look like something you've + + align:start position:0% +Does this look like something you've + + + align:start position:0% +Does this look like something you've +seen before? + + align:start position:0% + + + + align:start position:0% + +Okay. Does it look like something that + + align:start position:0% +Okay. Does it look like something that + + + align:start position:0% +Okay. Does it look like something that +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Well, go back to your notes and or + + align:start position:0% +Well, go back to your notes and or + + + align:start position:0% +Well, go back to your notes and or +otherwise just believe me this is true. + + align:start position:0% +otherwise just believe me this is true. + + + align:start position:0% +otherwise just believe me this is true. +Um Larry told me you've seen something + + align:start position:0% +Um Larry told me you've seen something + + + align:start position:0% +Um Larry told me you've seen something +like this. Maybe with different letters + + align:start position:0% +like this. Maybe with different letters + + + align:start position:0% +like this. Maybe with different letters +very likely with different letters. But + + align:start position:0% +very likely with different letters. But + + + align:start position:0% +very likely with different letters. But +the point is you have a set with small + + align:start position:0% +the point is you have a set with small + + + align:start position:0% +the point is you have a set with small +doubling but large PA projection. then + + align:start position:0% +doubling but large PA projection. then + + + align:start position:0% +doubling but large PA projection. then +the PA projection is large even after + + align:start position:0% +the PA projection is large even after + + + align:start position:0% +the PA projection is large even after +passing to a subset. + + align:start position:0% + + + + align:start position:0% + +Okay, so it looks like we've almost won + + align:start position:0% +Okay, so it looks like we've almost won + + + align:start position:0% +Okay, so it looks like we've almost won +because look at the claim + + align:start position:0% +because look at the claim + + + align:start position:0% +because look at the claim +and look at what we have here. + + align:start position:0% +and look at what we have here. + + + align:start position:0% +and look at what we have here. +Okay, have we really won? + + align:start position:0% + + + + align:start position:0% + +Not exactly because the claim was for A + + align:start position:0% +Not exactly because the claim was for A + + + align:start position:0% +Not exactly because the claim was for A +and we got it for A prime which is a + + align:start position:0% +and we got it for A prime which is a + + + align:start position:0% +and we got it for A prime which is a +dense subset of A but it is not A. So + + align:start position:0% +dense subset of A but it is not A. So + + + align:start position:0% +dense subset of A but it is not A. So +one has to work a bit to + + align:start position:0% +one has to work a bit to + + + align:start position:0% +one has to work a bit to +really win but you will have to trust me + + align:start position:0% +really win but you will have to trust me + + + align:start position:0% +really win but you will have to trust me +that one can win from here. So the claim + + align:start position:0% +that one can win from here. So the claim + + + align:start position:0% +that one can win from here. So the claim +was that + + align:start position:0% +was that + + + align:start position:0% +was that +what we obtained for a prime is true for + + align:start position:0% +what we obtained for a prime is true for + + + align:start position:0% +what we obtained for a prime is true for +a + + align:start position:0% +a + + + align:start position:0% +a +and we got it for a prime not for a. So + + align:start position:0% +and we got it for a prime not for a. So + + + align:start position:0% +and we got it for a prime not for a. So +I will briefly explain how to get it for + + align:start position:0% +I will briefly explain how to get it for + + + align:start position:0% +I will briefly explain how to get it for +a but I will not do all of the details + + align:start position:0% +a but I will not do all of the details + + + align:start position:0% +a but I will not do all of the details +because otherwise we'll be here forever. + + align:start position:0% +because otherwise we'll be here forever. + + + align:start position:0% +because otherwise we'll be here forever. +Uh maybe let's keep + + align:start position:0% +Uh maybe let's keep + + + align:start position:0% +Uh maybe let's keep +the objective inside. + + align:start position:0% + + + + align:start position:0% + +Okay, we can upgrade + + align:start position:0% + + + + align:start position:0% + +a prime to a + + align:start position:0% +a prime to a + + + align:start position:0% +a prime to a +and the idea + + align:start position:0% +and the idea + + + align:start position:0% +and the idea +is well either a prime is a in which + + align:start position:0% +is well either a prime is a in which + + + align:start position:0% +is well either a prime is a in which +case we win or if a prime is not all of + + align:start position:0% +case we win or if a prime is not all of + + + align:start position:0% +case we win or if a prime is not all of +a but it is almost all of a in the sense + + align:start position:0% +a but it is almost all of a in the sense + + + align:start position:0% +a but it is almost all of a in the sense +that a minus a prime is really small we + + align:start position:0% +that a minus a prime is really small we + + + align:start position:0% +that a minus a prime is really small we +still win uh because + + align:start position:0% +still win uh because + + + align:start position:0% +still win uh because +so if if the difference between a and a + + align:start position:0% +so if if the difference between a and a + + + align:start position:0% +so if if the difference between a and a +prime is really small you just apply + + align:start position:0% +prime is really small you just apply + + + align:start position:0% +prime is really small you just apply +trivial bounds on the very small part + + align:start position:0% +trivial bounds on the very small part + + + align:start position:0% +trivial bounds on the very small part +and we still win. So + + align:start position:0% + + + + align:start position:0% + +if a minus a prime is very small + + align:start position:0% + + + + align:start position:0% + +very small maybe of size less than delta + + align:start position:0% +very small maybe of size less than delta + + + align:start position:0% +very small maybe of size less than delta +to the plus e to something like this + + align:start position:0% +to the plus e to something like this + + + align:start position:0% +to the plus e to something like this +times the size of a + + align:start position:0% +times the size of a + + + align:start position:0% +times the size of a +we are fine otherwise + + align:start position:0% + + + + align:start position:0% + +do the same so apply the same argument + + align:start position:0% + + + + align:start position:0% + +to a minus a prime. + + align:start position:0% + + + + align:start position:0% + +If a prime is not very dense in a, then + + align:start position:0% +If a prime is not very dense in a, then + + + align:start position:0% +If a prime is not very dense in a, then +a minus a prime is still the delta is + + align:start position:0% +a minus a prime is still the delta is + + + align:start position:0% +a minus a prime is still the delta is +delta to the minus theta square set. And + + align:start position:0% +delta to the minus theta square set. And + + + align:start position:0% +delta to the minus theta square set. And +we can do the same and get a new a + + align:start position:0% +we can do the same and get a new a + + + align:start position:0% +we can do the same and get a new a +prime. + + align:start position:0% +prime. + + + align:start position:0% +prime. +So maybe the original a prime we can + + align:start position:0% +So maybe the original a prime we can + + + align:start position:0% +So maybe the original a prime we can +call it a prime one. + + align:start position:0% +call it a prime one. + + + align:start position:0% +call it a prime one. +And if we apply the same thing, we get + + align:start position:0% +And if we apply the same thing, we get + + + align:start position:0% +And if we apply the same thing, we get +an a prime two. Now uh at the same time + + align:start position:0% +an a prime two. Now uh at the same time + + + align:start position:0% +an a prime two. Now uh at the same time +we have to play the game that if + + align:start position:0% +we have to play the game that if + + + align:start position:0% +we have to play the game that if +something is true for one a is true for + + align:start position:0% +something is true for one a is true for + + + align:start position:0% +something is true for one a is true for +nearly all a because we found that there + + align:start position:0% +nearly all a because we found that there + + + align:start position:0% +nearly all a because we found that there +exist an a and there exist an a prime + + align:start position:0% +exist an a and there exist an a prime + + + align:start position:0% +exist an a and there exist an a prime +but in fact there are lots of a but the + + align:start position:0% +but in fact there are lots of a but the + + + align:start position:0% +but in fact there are lots of a but the +a prime could depend on a so one has to + + align:start position:0% +a prime could depend on a so one has to + + + align:start position:0% +a prime could depend on a so one has to +be a little bit careful + + align:start position:0% +be a little bit careful + + + align:start position:0% +be a little bit careful +but + + align:start position:0% +but + + + align:start position:0% +but +but one can play this game and + + align:start position:0% +but one can play this game and + + + align:start position:0% +but one can play this game and +eventually uh one gets + + align:start position:0% +eventually uh one gets + + + align:start position:0% +eventually uh one gets +so all of these sets have large size + + align:start position:0% +so all of these sets have large size + + + align:start position:0% +so all of these sets have large size +because they are dense in a prime. + + align:start position:0% + + + + align:start position:0% + +Where is it? A prime is dense in A. So + + align:start position:0% +Where is it? A prime is dense in A. So + + + align:start position:0% +Where is it? A prime is dense in A. So +at some point + + align:start position:0% + + + + align:start position:0% + +and they are all disjointed. They are + + align:start position:0% +and they are all disjointed. They are + + + align:start position:0% +and they are all disjointed. They are +all disjointed because we take away the + + align:start position:0% +all disjointed because we take away the + + + align:start position:0% +all disjointed because we take away the +previous ones when we apply this again. + + align:start position:0% +previous ones when we apply this again. + + + align:start position:0% +previous ones when we apply this again. +So at some point + + align:start position:0% +So at some point + + + align:start position:0% +So at some point +we reach a step where + + align:start position:0% +we reach a step where + + + align:start position:0% +we reach a step where +we have exhausted almost all of a + + align:start position:0% + + + + align:start position:0% + +let's say something like this and then + + align:start position:0% +let's say something like this and then + + + align:start position:0% +let's say something like this and then +we stop. + + align:start position:0% +we stop. + + + align:start position:0% +we stop. +Okay, but I'm cheating here because + + align:start position:0% +Okay, but I'm cheating here because + + + align:start position:0% +Okay, but I'm cheating here because +and then then we stop and then basically + + align:start position:0% +and then then we stop and then basically + + + align:start position:0% +and then then we stop and then basically +we win because if we have a set G which + + align:start position:0% +we win because if we have a set G which + + + align:start position:0% +we win because if we have a set G which +is dense in a in a * A. Okay. Uh we + + align:start position:0% +is dense in a in a * A. Okay. Uh we + + + align:start position:0% +is dense in a in a * A. Okay. Uh we +still don't really win yet. But if a set + + align:start position:0% +still don't really win yet. But if a set + + + align:start position:0% +still don't really win yet. But if a set +G is dense in A* A, it will be dense in + + align:start position:0% +G is dense in A* A, it will be dense in + + + align:start position:0% +G is dense in A* A, it will be dense in +A I prime time A + + align:start position:0% +A I prime time A + + + align:start position:0% +A I prime time A +G prime. Maybe a different prime. Okay, + + align:start position:0% +G prime. Maybe a different prime. Okay, + + + align:start position:0% +G prime. Maybe a different prime. Okay, +so one still has to work. Okay, plus + + align:start position:0% +so one still has to work. Okay, plus + + + align:start position:0% +so one still has to work. Okay, plus +some work plus more work. + + align:start position:0% + + + + align:start position:0% + +And I'm basically ignoring a here, the + + align:start position:0% +And I'm basically ignoring a here, the + + + align:start position:0% +And I'm basically ignoring a here, the +little a here. But it's okay to ignore + + align:start position:0% +little a here. But it's okay to ignore + + + align:start position:0% +little a here. But it's okay to ignore +the little a because everything you + + align:start position:0% +the little a because everything you + + + align:start position:0% +the little a because everything you +prove from one little a is true for + + align:start position:0% +prove from one little a is true for + + + align:start position:0% +prove from one little a is true for +nearly all little a. + + align:start position:0% +nearly all little a. + + + align:start position:0% +nearly all little a. +Maybe forget what I said. But okay, this + + align:start position:0% +Maybe forget what I said. But okay, this + + + align:start position:0% +Maybe forget what I said. But okay, this +is one thing you have to do. Just + + align:start position:0% +is one thing you have to do. Just + + + align:start position:0% +is one thing you have to do. Just +iterate. + + align:start position:0% +iterate. + + + align:start position:0% +iterate. +So iterate this. Here we get a dense a + + align:start position:0% +So iterate this. Here we get a dense a + + + align:start position:0% +So iterate this. Here we get a dense a +prime. We want to get all of a not the + + align:start position:0% +prime. We want to get all of a not the + + + align:start position:0% +prime. We want to get all of a not the +dense a prime. We iterate plus some + + align:start position:0% +dense a prime. We iterate plus some + + + align:start position:0% +dense a prime. We iterate plus some +double counting. + + align:start position:0% +double counting. + + + align:start position:0% +double counting. +We get + + align:start position:0% +We get + + + align:start position:0% +We get +that claim + + align:start position:0% + + + + align:start position:0% + +any questions + + align:start position:0% +any questions + + + align:start position:0% +any questions +so one has to work here so I I haven't + + align:start position:0% +so one has to work here so I I haven't + + + align:start position:0% +so one has to work here so I I haven't +proved it so I don't expect you to see + + align:start position:0% +proved it so I don't expect you to see + + + align:start position:0% +proved it so I don't expect you to see +the proof so one thing you have to do in + + align:start position:0% +the proof so one thing you have to do in + + + align:start position:0% +the proof so one thing you have to do in +the proof is iterate but you have to do + + align:start position:0% +the proof is iterate but you have to do + + + align:start position:0% +the proof is iterate but you have to do +more things and double count carefully + + align:start position:0% +more things and double count carefully + + + align:start position:0% +more things and double count carefully +um but eventually one gets that so one + + align:start position:0% +um but eventually one gets that so one + + + align:start position:0% +um but eventually one gets that so one +is able to upgrade a prime to a okay so + + align:start position:0% +is able to upgrade a prime to a okay so + + + align:start position:0% +is able to upgrade a prime to a okay so +that claim is True. + + align:start position:0% +that claim is True. + + + align:start position:0% +that claim is True. +So that claim says that there exists an + + align:start position:0% +So that claim says that there exists an + + + align:start position:0% +So that claim says that there exists an +A and once there is one A there are many + + align:start position:0% +A and once there is one A there are many + + + align:start position:0% +A and once there is one A there are many +A's nearly all A's. So that the pi A + + align:start position:0% +A's nearly all A's. So that the pi A + + + align:start position:0% +A's nearly all A's. So that the pi A +projection of any dense subset of A plus + + align:start position:0% +projection of any dense subset of A plus + + + align:start position:0% +projection of any dense subset of A plus +A grows + + align:start position:0% + + + + align:start position:0% + +and now we are really close to the to + + align:start position:0% +and now we are really close to the to + + + align:start position:0% +and now we are really close to the to +the end of that goal. + + align:start position:0% + + + + align:start position:0% + +So a prime a plus a a plus little a a is + + align:start position:0% +So a prime a plus a a plus little a a is + + + align:start position:0% +So a prime a plus a a plus little a a is +not necessarily uniform but we know that + + align:start position:0% +not necessarily uniform but we know that + + + align:start position:0% +not necessarily uniform but we know that +it contains a uniform subset and when we + + align:start position:0% +it contains a uniform subset and when we + + + align:start position:0% +it contains a uniform subset and when we +pass to a uniform subset we can make it + + align:start position:0% +pass to a uniform subset we can make it + + + align:start position:0% +pass to a uniform subset we can make it +large + + align:start position:0% +large + + + align:start position:0% +large +for any sub additive + + align:start position:0% +for any sub additive + + + align:start position:0% +for any sub additive +function set function mu. + + align:start position:0% +function set function mu. + + + align:start position:0% +function set function mu. +Okay, so this is the mu we are going to + + align:start position:0% +Okay, so this is the mu we are going to + + + align:start position:0% +Okay, so this is the mu we are going to +use now. So mu of b + + align:start position:0% +use now. So mu of b + + + align:start position:0% +use now. So mu of b +is going to be okay. So + + align:start position:0% +is going to be okay. So + + + align:start position:0% +is going to be okay. So +fix little a for which the claim holds. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So this is the clean star. So we fix a + + align:start position:0% +So this is the clean star. So we fix a + + + align:start position:0% +So this is the clean star. So we fix a +little a so that this holds + + align:start position:0% +little a so that this holds + + + align:start position:0% +little a so that this holds +and then let mu of b and here b is a + + align:start position:0% +and then let mu of b and here b is a + + + align:start position:0% +and then let mu of b and here b is a +subset of 01 so it's a subset of a + + align:start position:0% +subset of 01 so it's a subset of a + + + align:start position:0% +subset of 01 so it's a subset of a +really + + align:start position:0% +really + + + align:start position:0% +really +is the delta covering number not of b + + align:start position:0% +is the delta covering number not of b + + + align:start position:0% +is the delta covering number not of b +but of pi a inverse of b. + + align:start position:0% + + + + align:start position:0% + +So this is sub additive right because + + align:start position:0% +So this is sub additive right because + + + align:start position:0% +So this is sub additive right because +what is mu of b1 union b2 well uh if you + + align:start position:0% +what is mu of b1 union b2 well uh if you + + + align:start position:0% +what is mu of b1 union b2 well uh if you +take pre images + + align:start position:0% +take pre images + + + align:start position:0% +take pre images +you get something which is contained in + + align:start position:0% +you get something which is contained in + + + align:start position:0% +you get something which is contained in +the pre image of the in the in the union + + align:start position:0% +the pre image of the in the in the union + + + align:start position:0% +the pre image of the in the in the union +of the pre images and then the delta + + align:start position:0% +of the pre images and then the delta + + + align:start position:0% +of the pre images and then the delta +covering number is sub additive. Does + + align:start position:0% +covering number is sub additive. Does + + + align:start position:0% +covering number is sub additive. Does +this mean pi a inverse of b intersect a + + align:start position:0% +this mean pi a inverse of b intersect a + + + align:start position:0% +this mean pi a inverse of b intersect a +cross a? + + align:start position:0% +cross a? + + + align:start position:0% +cross a? +>> Yes. Sorry. Thank you. + + align:start position:0% + + + + align:start position:0% + +So this is finitely subjective + + align:start position:0% +So this is finitely subjective + + + align:start position:0% +So this is finitely subjective +because delta covering number is + + align:start position:0% +because delta covering number is + + + align:start position:0% +because delta covering number is +subjective and we are just taking delta + + align:start position:0% +subjective and we are just taking delta + + + align:start position:0% +subjective and we are just taking delta +covering number together with the + + align:start position:0% +covering number together with the + + + align:start position:0% +covering number together with the +pre-image which is already subjective. + + align:start position:0% + + + + align:start position:0% + +Okay. So by lema from last time by the + + align:start position:0% +Okay. So by lema from last time by the + + + align:start position:0% +Okay. So by lema from last time by the +uniformization lema from last time + + align:start position:0% + + + + align:start position:0% + +there exists + + align:start position:0% +there exists + + + align:start position:0% +there exists +an a prime contained in a + + align:start position:0% + + + + align:start position:0% + +uh which is uniform. + + align:start position:0% +uh which is uniform. + + + align:start position:0% +uh which is uniform. +Sorry, not in A. Ah, there existed B + + align:start position:0% +Sorry, not in A. Ah, there existed B + + + align:start position:0% +Sorry, not in A. Ah, there existed B +contained in A plus little A A. + + align:start position:0% +contained in A plus little A A. + + + align:start position:0% +contained in A plus little A A. +So we are going to apply uniformization + + align:start position:0% +So we are going to apply uniformization + + + align:start position:0% +So we are going to apply uniformization +to A plus little A A. + + align:start position:0% + + + + align:start position:0% + +We are trying to show that this set + + align:start position:0% +We are trying to show that this set + + + align:start position:0% +We are trying to show that this set +contains a delta S plus epsilon set. So + + align:start position:0% +contains a delta S plus epsilon set. So + + + align:start position:0% +contains a delta S plus epsilon set. So +this is our ultimate goal and we know + + align:start position:0% +this is our ultimate goal and we know + + + align:start position:0% +this is our ultimate goal and we know +that if this set was uniform, it would + + align:start position:0% +that if this set was uniform, it would + + + align:start position:0% +that if this set was uniform, it would +be enough to show that it grows at every + + align:start position:0% +be enough to show that it grows at every + + + align:start position:0% +be enough to show that it grows at every +scale to reach the conclusion. So we + + align:start position:0% +scale to reach the conclusion. So we + + + align:start position:0% +scale to reach the conclusion. So we +want to make it uniform but we need to + + align:start position:0% +want to make it uniform but we need to + + + align:start position:0% +want to make it uniform but we need to +know that the uniform subset grows at + + align:start position:0% +know that the uniform subset grows at + + + align:start position:0% +know that the uniform subset grows at +every scale. + + align:start position:0% +every scale. + + + align:start position:0% +every scale. +Okay. So by uniformization there exist a + + align:start position:0% +Okay. So by uniformization there exist a + + + align:start position:0% +Okay. So by uniformization there exist a +b in a plus e a such that this mu + + align:start position:0% +b in a plus e a such that this mu + + + align:start position:0% +b in a plus e a such that this mu +of b is larger than delta to the minus + + align:start position:0% +of b is larger than delta to the minus + + + align:start position:0% +of b is larger than delta to the minus +ea squar + + align:start position:0% + + + + align:start position:0% + +times the measure of a + a a. And what + + align:start position:0% +times the measure of a + a a. And what + + + align:start position:0% +times the measure of a + a a. And what +is the measure of a plus a a? This is + + align:start position:0% +is the measure of a plus a a? This is + + + align:start position:0% +is the measure of a plus a a? This is +just the delta covering number of a * a. + + align:start position:0% + + + + align:start position:0% + +Okay. So this is the delta covering + + align:start position:0% +Okay. So this is the delta covering + + + align:start position:0% +Okay. So this is the delta covering +number + + align:start position:0% +number + + + align:start position:0% +number +of pi a inverse of b. + + align:start position:0% + + + + align:start position:0% + +So this is a sorry again I forgot to + + align:start position:0% +So this is a sorry again I forgot to + + + align:start position:0% +So this is a sorry again I forgot to +intersect with a * a. + + align:start position:0% + + + + align:start position:0% + +So this is the g to which we can apply + + align:start position:0% +So this is the g to which we can apply + + + align:start position:0% +So this is the g to which we can apply +the claim. + + align:start position:0% +the claim. + + + align:start position:0% +the claim. +So this is a dense subset of a * a. + + align:start position:0% +So this is a dense subset of a * a. + + + align:start position:0% +So this is a dense subset of a * a. +And we know that for every dense subset + + align:start position:0% +And we know that for every dense subset + + + align:start position:0% +And we know that for every dense subset +of a * a the pi a projection grows. + + align:start position:0% +of a * a the pi a projection grows. + + + align:start position:0% +of a * a the pi a projection grows. +In particular, the pi a projection of + + align:start position:0% +In particular, the pi a projection of + + + align:start position:0% +In particular, the pi a projection of +this grows. But this is pi a inverse. So + + align:start position:0% +this grows. But this is pi a inverse. So + + + align:start position:0% +this grows. But this is pi a inverse. So +if we apply pi a we land in b and in + + align:start position:0% +if we apply pi a we land in b and in + + + align:start position:0% +if we apply pi a we land in b and in +particular we land in a plus little aa + + align:start position:0% +particular we land in a plus little aa + + + align:start position:0% +particular we land in a plus little aa +but in particular we land in b which is + + align:start position:0% +but in particular we land in b which is + + + align:start position:0% +but in particular we land in b which is +uniform. + + align:start position:0% + + + + align:start position:0% + +Okay. So apply + + align:start position:0% + + + + align:start position:0% + +claim star + + align:start position:0% +claim star + + + align:start position:0% +claim star +to g equals pi i inverse of b + + align:start position:0% +to g equals pi i inverse of b + + + align:start position:0% +to g equals pi i inverse of b +intersection a * a is does satisfies the + + align:start position:0% +intersection a * a is does satisfies the + + + align:start position:0% +intersection a * a is does satisfies the +density assumption + + align:start position:0% + + + + align:start position:0% + +and this is because uniform sets can be + + align:start position:0% +and this is because uniform sets can be + + + align:start position:0% +and this is because uniform sets can be +taken deaths. So again here I have to + + align:start position:0% +taken deaths. So again here I have to + + + align:start position:0% +taken deaths. So again here I have to +choose maybe a different delta than + + align:start position:0% +choose maybe a different delta than + + + align:start position:0% +choose maybe a different delta than +before although I guess the same delta + + align:start position:0% +before although I guess the same delta + + + align:start position:0% +before although I guess the same delta +works because it's the same numerology. + + align:start position:0% +works because it's the same numerology. + + + align:start position:0% +works because it's the same numerology. +So that this is true. + + align:start position:0% +So that this is true. + + + align:start position:0% +So that this is true. +We can make we can take uniform sets + + align:start position:0% +We can make we can take uniform sets + + + align:start position:0% +We can make we can take uniform sets +which are as dense in the exponential + + align:start position:0% +which are as dense in the exponential + + + align:start position:0% +which are as dense in the exponential +sense as we want. This is exactly what's + + align:start position:0% +sense as we want. This is exactly what's + + + align:start position:0% +sense as we want. This is exactly what's +going on here. + + align:start position:0% +going on here. + + + align:start position:0% +going on here. +Okay. And the conclusion is that + + align:start position:0% +Okay. And the conclusion is that + + + align:start position:0% +Okay. And the conclusion is that +the delta covering number + + align:start position:0% + + + + align:start position:0% + +grows + + align:start position:0% + + + + align:start position:0% + +sorry not by a b ah + + align:start position:0% + + + + align:start position:0% + +by a of a * + + align:start position:0% + + + + align:start position:0% + +intersected with B, I guess. + + align:start position:0% + + + + align:start position:0% + +Okay. So, um, + + align:start position:0% + + + + align:start position:0% + +okay. So now we are getting so we are + + align:start position:0% +okay. So now we are getting so we are + + + align:start position:0% +okay. So now we are getting so we are +one step closer uh because now we have a + + align:start position:0% +one step closer uh because now we have a + + + align:start position:0% +one step closer uh because now we have a +uniform subset of a * little a a + + align:start position:0% +uniform subset of a * little a a + + + align:start position:0% +uniform subset of a * little a a +and the delta covering number + + align:start position:0% + + + + align:start position:0% + +well I guess B is a subset of this. So + + align:start position:0% +well I guess B is a subset of this. So + + + align:start position:0% +well I guess B is a subset of this. So +here one could have just B. So the delta + + align:start position:0% +here one could have just B. So the delta + + + align:start position:0% +here one could have just B. So the delta +covering number grows. + + align:start position:0% +covering number grows. + + + align:start position:0% +covering number grows. +We know that if a set is uniform and the + + align:start position:0% +We know that if a set is uniform and the + + + align:start position:0% +We know that if a set is uniform and the +row covering number grows for every row + + align:start position:0% +row covering number grows for every row + + + align:start position:0% +row covering number grows for every row +and in fact we don't need every row we + + align:start position:0% +and in fact we don't need every row we + + + align:start position:0% +and in fact we don't need every row we +is enough to consider rows which are + + align:start position:0% +is enough to consider rows which are + + + align:start position:0% +is enough to consider rows which are +powers of delta then they are h + + align:start position:0% +powers of delta then they are h + + + align:start position:0% +powers of delta then they are h +delta s plus the growth set. So we just + + align:start position:0% +delta s plus the growth set. So we just + + + align:start position:0% +delta s plus the growth set. So we just +repeat. So here we have something for + + align:start position:0% +repeat. So here we have something for + + + align:start position:0% +repeat. So here we have something for +for delta but then um + + align:start position:0% +for delta but then um + + + align:start position:0% +for delta but then um +okay let's see what is the right order + + align:start position:0% +okay let's see what is the right order + + + align:start position:0% +okay let's see what is the right order +to do this. So I want to claim that what + + align:start position:0% +to do this. So I want to claim that what + + + align:start position:0% +to do this. So I want to claim that what +we did for delta we can do for any + + align:start position:0% +we did for delta we can do for any + + + align:start position:0% +we did for delta we can do for any +scale. So there is nothing special about + + align:start position:0% +scale. So there is nothing special about + + + align:start position:0% +scale. So there is nothing special about +delta because a itself is uniform. All + + align:start position:0% +delta because a itself is uniform. All + + + align:start position:0% +delta because a itself is uniform. All +of this that we did for delta we can do + + align:start position:0% +of this that we did for delta we can do + + + align:start position:0% +of this that we did for delta we can do +it for any other scale uh row. + + align:start position:0% +it for any other scale uh row. + + + align:start position:0% +it for any other scale uh row. +But uh the uniform set that we get can + + align:start position:0% +But uh the uniform set that we get can + + + align:start position:0% +But uh the uniform set that we get can +depend on the scale. + + align:start position:0% + + + + align:start position:0% + +So what is the right order to do this? + + align:start position:0% +So what is the right order to do this? + + + align:start position:0% +So what is the right order to do this? +So the goal is to use the lema from last + + align:start position:0% +So the goal is to use the lema from last + + + align:start position:0% +So the goal is to use the lema from last +time that says that if it is uniform and + + align:start position:0% +time that says that if it is uniform and + + + align:start position:0% +time that says that if it is uniform and +the row covering number is large for + + align:start position:0% +the row covering number is large for + + + align:start position:0% +the row covering number is large for +every row and in fact one doesn't need + + align:start position:0% +every row and in fact one doesn't need + + + align:start position:0% +every row and in fact one doesn't need +every every row. It's enough to consider + + align:start position:0% +every every row. It's enough to consider + + + align:start position:0% +every every row. It's enough to consider +powers of the delta based in the + + align:start position:0% +powers of the delta based in the + + + align:start position:0% +powers of the delta based in the +uniformity. + + align:start position:0% +uniformity. + + + align:start position:0% +uniformity. +then it is a delta s set where the s + + align:start position:0% +then it is a delta s set where the s + + + align:start position:0% +then it is a delta s set where the s +comes from the size of the row covering + + align:start position:0% +comes from the size of the row covering + + + align:start position:0% +comes from the size of the row covering +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +and okay by using this idea for every + + align:start position:0% +and okay by using this idea for every + + + align:start position:0% +and okay by using this idea for every +row so we did it with for delta but the + + align:start position:0% +row so we did it with for delta but the + + + align:start position:0% +row so we did it with for delta but the +assumptions hold for every row at least + + align:start position:0% +assumptions hold for every row at least + + + align:start position:0% +assumptions hold for every row at least +for every row which is not very close to + + align:start position:0% +for every row which is not very close to + + + align:start position:0% +for every row which is not very close to +one so we can do the same + + align:start position:0% + + + + align:start position:0% + +uh the only danger is that we could get + + align:start position:0% +uh the only danger is that we could get + + + align:start position:0% +uh the only danger is that we could get +a different b for different rows we + + align:start position:0% +a different b for different rows we + + + align:start position:0% +a different b for different rows we +could get different beasts. + + align:start position:0% + + + + align:start position:0% + +And I'm not very happy about this. So, + + align:start position:0% +And I'm not very happy about this. So, + + + align:start position:0% +And I'm not very happy about this. So, +how do we deal with this? + + align:start position:0% + + + + align:start position:0% + +One thing one could try to do but I + + align:start position:0% +One thing one could try to do but I + + + align:start position:0% +One thing one could try to do but I +think we lose too much is okay delta is + + align:start position:0% +think we lose too much is okay delta is + + + align:start position:0% +think we lose too much is okay delta is +delta to the m. Now we want to go to + + align:start position:0% +delta to the m. Now we want to go to + + + align:start position:0% +delta to the m. Now we want to go to +delta to the m minus one. So we could + + align:start position:0% +delta to the m minus one. So we could + + + align:start position:0% +delta to the m minus one. So we could +just replace + + align:start position:0% +just replace + + + align:start position:0% +just replace +a plus little a by b. + + align:start position:0% +a plus little a by b. + + + align:start position:0% +a plus little a by b. +But then we will have another subset of + + align:start position:0% +But then we will have another subset of + + + align:start position:0% +But then we will have another subset of +b and we are going to lose this factor + + align:start position:0% +b and we are going to lose this factor + + + align:start position:0% +b and we are going to lose this factor +logarithmically many times and that is + + align:start position:0% +logarithmically many times and that is + + + align:start position:0% +logarithmically many times and that is +too many times. So yeah I don't want to + + align:start position:0% +too many times. So yeah I don't want to + + + align:start position:0% +too many times. So yeah I don't want to +do that. I will lose too much. Um, + + align:start position:0% + + + + align:start position:0% + +okay. So, there is something I'm missing + + align:start position:0% +okay. So, there is something I'm missing + + + align:start position:0% +okay. So, there is something I'm missing +and I'm not going to figure it out right + + align:start position:0% +and I'm not going to figure it out right + + + align:start position:0% +and I'm not going to figure it out right +now. So, uh, because I told you that + + align:start position:0% +now. So, uh, because I told you that + + + align:start position:0% +now. So, uh, because I told you that +Yes. + + align:start position:0% +Yes. + + + align:start position:0% +Yes. +>> Um, can you prove the claim + + align:start position:0% +>> Um, can you prove the claim + + + align:start position:0% +>> Um, can you prove the claim +simultaneously for all scales, replace + + align:start position:0% +simultaneously for all scales, replace + + + align:start position:0% +simultaneously for all scales, replace +that delta by rows, all the different + + align:start position:0% +that delta by rows, all the different + + + align:start position:0% +that delta by rows, all the different +rows, and then then I think that would + + align:start position:0% +rows, and then then I think that would + + + align:start position:0% +rows, and then then I think that would +fix it. + + align:start position:0% +fix it. + + + align:start position:0% +fix it. +>> Yeah. You want to have the same G for + + align:start position:0% +>> Yeah. You want to have the same G for + + + align:start position:0% +>> Yeah. You want to have the same G for +every scale. + + align:start position:0% +every scale. + + + align:start position:0% +every scale. +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +>> Yeah. uh + + align:start position:0% +>> Yeah. uh + + + align:start position:0% +>> Yeah. uh +>> if you conclude that's stronger claim + + align:start position:0% +>> if you conclude that's stronger claim + + + align:start position:0% +>> if you conclude that's stronger claim +then it will solve + + align:start position:0% +then it will solve + + + align:start position:0% +then it will solve +>> yes but why can't we get the same G for + + align:start position:0% +>> yes but why can't we get the same G for + + + align:start position:0% +>> yes but why can't we get the same G for +for all the scales + + align:start position:0% +for all the scales + + + align:start position:0% +for all the scales +okay because I told you I wouldn't give + + align:start position:0% +okay because I told you I wouldn't give + + + align:start position:0% +okay because I told you I wouldn't give +a complete proof and just a sketch of + + align:start position:0% +a complete proof and just a sketch of + + + align:start position:0% +a complete proof and just a sketch of +some of the ideas well here is a sketch + + align:start position:0% +some of the ideas well here is a sketch + + + align:start position:0% +some of the ideas well here is a sketch +of some of the ideas and is is something + + align:start position:0% +of some of the ideas and is is something + + + align:start position:0% +of some of the ideas and is is something +technical that so really the ideas are + + align:start position:0% +technical that so really the ideas are + + + align:start position:0% +technical that so really the ideas are +what I explained and what I'm missing is + + align:start position:0% +what I explained and what I'm missing is + + + align:start position:0% +what I explained and what I'm missing is +something technical it's not + + align:start position:0% +something technical it's not + + + align:start position:0% +something technical it's not +fundamental I would + + align:start position:0% +fundamental I would + + + align:start position:0% +fundamental I would +just to summarize what's been what's + + align:start position:0% +just to summarize what's been what's + + + align:start position:0% +just to summarize what's been what's +been going on. I still have to explain + + align:start position:0% +been going on. I still have to explain + + + align:start position:0% +been going on. I still have to explain +once we prove that goal how to continue + + align:start position:0% +once we prove that goal how to continue + + + align:start position:0% +once we prove that goal how to continue +with the rest of bans the proof of the + + align:start position:0% +with the rest of bans the proof of the + + + align:start position:0% +with the rest of bans the proof of the +rest of bans theorem but really this is + + align:start position:0% +rest of bans theorem but really this is + + + align:start position:0% +rest of bans theorem but really this is +really the most difficult step where + + align:start position:0% +really the most difficult step where + + + align:start position:0% +really the most difficult step where +things really change from the final + + align:start position:0% +things really change from the final + + + align:start position:0% +things really change from the final +field setting okay so let me uh + + align:start position:0% +field setting okay so let me uh + + + align:start position:0% +field setting okay so let me uh +sort of briefly explain again everything + + align:start position:0% +sort of briefly explain again everything + + + align:start position:0% +sort of briefly explain again everything +that's been going on uh so we know that + + align:start position:0% +that's been going on uh so we know that + + + align:start position:0% +that's been going on uh so we know that +a plus a grows but we want to show that + + align:start position:0% +a plus a grows but we want to show that + + + align:start position:0% +a plus a grows but we want to show that +it also satisfies a stronger + + align:start position:0% +it also satisfies a stronger + + + align:start position:0% +it also satisfies a stronger +non-conentration assumption that the S + + align:start position:0% +non-conentration assumption that the S + + + align:start position:0% +non-conentration assumption that the S +in the non-conentration assumption also + + align:start position:0% +in the non-conentration assumption also + + + align:start position:0% +in the non-conentration assumption also +grows. + + align:start position:0% +grows. + + + align:start position:0% +grows. +Okay, first we can take A to be uniform. + + align:start position:0% +Okay, first we can take A to be uniform. + + + align:start position:0% +Okay, first we can take A to be uniform. +If A is uniform, then we know that A + + align:start position:0% +If A is uniform, then we know that A + + + align:start position:0% +If A is uniform, then we know that A +itself is a row set for every row. And + + align:start position:0% +itself is a row set for every row. And + + + align:start position:0% +itself is a row set for every row. And +this allows us to reach conclusions for + + align:start position:0% +this allows us to reach conclusions for + + + align:start position:0% +this allows us to reach conclusions for +every scale row, which is something that + + align:start position:0% +every scale row, which is something that + + + align:start position:0% +every scale row, which is something that +we have to use in the step that I'm + + align:start position:0% +we have to use in the step that I'm + + + align:start position:0% +we have to use in the step that I'm +missing as well. We use it we used it + + align:start position:0% +missing as well. We use it we used it + + + align:start position:0% +missing as well. We use it we used it +before, but clearly we have to use it + + align:start position:0% +before, but clearly we have to use it + + + align:start position:0% +before, but clearly we have to use it +again. + + align:start position:0% +again. + + + align:start position:0% +again. +And then we know that a plus little aa + + align:start position:0% +And then we know that a plus little aa + + + align:start position:0% +And then we know that a plus little aa +grows at every scale. If it was true + + align:start position:0% +grows at every scale. If it was true + + + align:start position:0% +grows at every scale. If it was true +that a plus little a a was uniform + + align:start position:0% +that a plus little a a was uniform + + + align:start position:0% +that a plus little a a was uniform +then we would win because for uniform + + align:start position:0% +then we would win because for uniform + + + align:start position:0% +then we would win because for uniform +sets we saw last time that if they are + + align:start position:0% +sets we saw last time that if they are + + + align:start position:0% +sets we saw last time that if they are +large at every scale then they satisfy + + align:start position:0% +large at every scale then they satisfy + + + align:start position:0% +large at every scale then they satisfy +the corresponding non-conentration + + align:start position:0% +the corresponding non-conentration + + + align:start position:0% +the corresponding non-conentration +condition. + + align:start position:0% + + + + align:start position:0% + +So we have to take a large uniform + + align:start position:0% +So we have to take a large uniform + + + align:start position:0% +So we have to take a large uniform +subset of a but large with respect to + + align:start position:0% +subset of a but large with respect to + + + align:start position:0% +subset of a but large with respect to +what? Well, large respect to this + + align:start position:0% +what? Well, large respect to this + + + align:start position:0% +what? Well, large respect to this +because this is what allows what allow + + align:start position:0% +because this is what allows what allow + + + align:start position:0% +because this is what allows what allow +us to use the fact that if we project + + align:start position:0% +us to use the fact that if we project + + + align:start position:0% +us to use the fact that if we project +something dense in a time a then we grow + + align:start position:0% +something dense in a time a then we grow + + + align:start position:0% +something dense in a time a then we grow +and how do we know that if project + + align:start position:0% +and how do we know that if project + + + align:start position:0% +and how do we know that if project +something dense in a time a then we grow + + align:start position:0% +something dense in a time a then we grow + + + align:start position:0% +something dense in a time a then we grow +we have to combine two things firstic + + align:start position:0% +we have to combine two things firstic + + + align:start position:0% +we have to combine two things firstic +hours and valid hours. So for valued + + align:start position:0% +hours and valid hours. So for valued + + + align:start position:0% +hours and valid hours. So for valued +hours we just take an arbitrary element + + align:start position:0% +hours we just take an arbitrary element + + + align:start position:0% +hours we just take an arbitrary element +of a in this case we took one but it can + + align:start position:0% +of a in this case we took one but it can + + + align:start position:0% +of a in this case we took one but it can +be an arbitrary element of a we apply + + align:start position:0% +be an arbitrary element of a we apply + + + align:start position:0% +be an arbitrary element of a we apply +hours. So either that element already + + align:start position:0% +hours. So either that element already + + + align:start position:0% +hours. So either that element already +works and we are done for that go for + + align:start position:0% +works and we are done for that go for + + + align:start position:0% +works and we are done for that go for +the claim star or if it doesn't work + + align:start position:0% +the claim star or if it doesn't work + + + align:start position:0% +the claim star or if it doesn't work +then we are under the assumptions of + + align:start position:0% +then we are under the assumptions of + + + align:start position:0% +then we are under the assumptions of +valuic hours. we apply valuic hours and + + align:start position:0% +valuic hours. we apply valuic hours and + + + align:start position:0% +valuic hours. we apply valuic hours and +then we end up with the set that + + align:start position:0% +then we end up with the set that + + + align:start position:0% +then we end up with the set that +satisfies the assumption of something + + align:start position:0% +satisfies the assumption of something + + + align:start position:0% +satisfies the assumption of something +else that you've seen in the finite + + align:start position:0% +else that you've seen in the finite + + + align:start position:0% +else that you've seen in the finite +field setting which is that if you have + + align:start position:0% +field setting which is that if you have + + + align:start position:0% +field setting which is that if you have +a very small subset an expansion under + + align:start position:0% +a very small subset an expansion under + + + align:start position:0% +a very small subset an expansion under +pi a then this expansion under pa is + + align:start position:0% +pi a then this expansion under pa is + + + align:start position:0% +pi a then this expansion under pa is +robust under passing two subsets. So in + + align:start position:0% +robust under passing two subsets. So in + + + align:start position:0% +robust under passing two subsets. So in +either case we get that pi a of d subset + + align:start position:0% +either case we get that pi a of d subset + + + align:start position:0% +either case we get that pi a of d subset +of a * a is large and this allows us to + + align:start position:0% +of a * a is large and this allows us to + + + align:start position:0% +of a * a is large and this allows us to +use uniformity with this mu. + + align:start position:0% +use uniformity with this mu. + + + align:start position:0% +use uniformity with this mu. +So that's a bit of a summary of the main + + align:start position:0% +So that's a bit of a summary of the main + + + align:start position:0% +So that's a bit of a summary of the main +steps to show the goal. + + align:start position:0% +steps to show the goal. + + + align:start position:0% +steps to show the goal. +Okay. Plus technical details + + align:start position:0% +Okay. Plus technical details + + + align:start position:0% +Okay. Plus technical details +I can recall right now. Sorry about + + align:start position:0% +I can recall right now. Sorry about + + + align:start position:0% +I can recall right now. Sorry about +that. + + align:start position:0% + + + + align:start position:0% + +Uh this implies the goal. + + align:start position:0% +Uh this implies the goal. + + + align:start position:0% +Uh this implies the goal. +the goal that goal. + + align:start position:0% + + + + align:start position:0% + +Okay. Why did you spend so much time + + align:start position:0% +Okay. Why did you spend so much time + + + align:start position:0% +Okay. Why did you spend so much time +towards this goal? Because now we can + + align:start position:0% +towards this goal? Because now we can + + + align:start position:0% +towards this goal? Because now we can +iterate. We knew that if a is a delta s + + align:start position:0% +iterate. We knew that if a is a delta s + + + align:start position:0% +iterate. We knew that if a is a delta s +delta to the minus epsilon set, then a + + align:start position:0% +delta to the minus epsilon set, then a + + + align:start position:0% +delta to the minus epsilon set, then a +plus a a grows. But not only it grows, + + align:start position:0% +plus a a grows. But not only it grows, + + + align:start position:0% +plus a a grows. But not only it grows, +it contains a delta s plus epsilon delta + + align:start position:0% +it contains a delta s plus epsilon delta + + + align:start position:0% +it contains a delta s plus epsilon delta +to the minus ita prime set. And then we + + align:start position:0% +to the minus ita prime set. And then we + + + align:start position:0% +to the minus ita prime set. And then we +can iterate. + + align:start position:0% +can iterate. + + + align:start position:0% +can iterate. +So a plus little a is our new + + align:start position:0% +So a plus little a is our new + + + align:start position:0% +So a plus little a is our new +a. + + align:start position:0% + + + + align:start position:0% + +So iterating + + align:start position:0% + + + + align:start position:0% + +a goes to a plus little a + + align:start position:0% + + + + align:start position:0% + +for every epsilon uh maybe let's not + + align:start position:0% +for every epsilon uh maybe let's not + + + align:start position:0% +for every epsilon uh maybe let's not +call it epsilon for every toao + + align:start position:0% +call it epsilon for every toao + + + align:start position:0% +call it epsilon for every toao +there exist a polomial that depends on + + align:start position:0% +there exist a polomial that depends on + + + align:start position:0% +there exist a polomial that depends on +toao is a very large degree if tow is + + align:start position:0% +toao is a very large degree if tow is + + + align:start position:0% +toao is a very large degree if tow is +close to zero + + align:start position:0% +close to zero + + + align:start position:0% +close to zero +such that qa of A is a delta + + align:start position:0% +such that qa of A is a delta + + + align:start position:0% +such that qa of A is a delta +1 minus toao. So the s can become + + align:start position:0% +1 minus toao. So the s can become + + + align:start position:0% +1 minus toao. So the s can become +arbitrarily close to one. + + align:start position:0% +arbitrarily close to one. + + + align:start position:0% +arbitrarily close to one. +Delta to the minus some eat tilda that + + align:start position:0% +Delta to the minus some eat tilda that + + + align:start position:0% +Delta to the minus some eat tilda that +depends on how many times we have to + + align:start position:0% +depends on how many times we have to + + + align:start position:0% +depends on how many times we have to +iterate set and by is I mean contains. + + align:start position:0% + + + + align:start position:0% + +Yes, + + align:start position:0% +Yes, + + + align:start position:0% +Yes, +>> you said that epsilon is going to change + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% +a + + + align:start position:0% +a +>> yeah I think instead of epsilon is + + align:start position:0% +>> yeah I think instead of epsilon is + + + align:start position:0% +>> yeah I think instead of epsilon is +epsilon over two + + align:start position:0% +epsilon over two + + + align:start position:0% +epsilon over two +>> so but then if the epsilons are + + align:start position:0% +>> so but then if the epsilons are + + + align:start position:0% +>> so but then if the epsilons are +shrinking how are you getting arbitrary + + align:start position:0% +shrinking how are you getting arbitrary + + + align:start position:0% +shrinking how are you getting arbitrary +close to + + align:start position:0% +close to + + + align:start position:0% +close to +>> yeah that's a good question so epsilon + + align:start position:0% +>> yeah that's a good question so epsilon + + + align:start position:0% +>> yeah that's a good question so epsilon +okay epsilon in some sense is shrinking + + align:start position:0% +okay epsilon in some sense is shrinking + + + align:start position:0% +okay epsilon in some sense is shrinking +but okay so there there is one epsilon + + align:start position:0% +but okay so there there is one epsilon + + + align:start position:0% +but okay so there there is one epsilon +which is the epsilon for the size of a + + align:start position:0% +which is the epsilon for the size of a + + + align:start position:0% +which is the epsilon for the size of a +plus little aa and there is potentially + + align:start position:0% +plus little aa and there is potentially + + + align:start position:0% +plus little aa and there is potentially +a different epsilon + + align:start position:0% +a different epsilon + + + align:start position:0% +a different epsilon +If we want to find a delta s plus + + align:start position:0% +If we want to find a delta s plus + + + align:start position:0% +If we want to find a delta s plus +epsilon set inside a plus little aa + + align:start position:0% +epsilon set inside a plus little aa + + + align:start position:0% +epsilon set inside a plus little aa +those two epsilons I think one is + + align:start position:0% +those two epsilons I think one is + + + align:start position:0% +those two epsilons I think one is +epsilon the other is epsilon / two but + + align:start position:0% +epsilon the other is epsilon / two but + + + align:start position:0% +epsilon the other is epsilon / two but +the point is that they depend on s + + align:start position:0% +the point is that they depend on s + + + align:start position:0% +the point is that they depend on s +continuously both of them + + align:start position:0% +continuously both of them + + + align:start position:0% +continuously both of them +so they are continuous they can be taken + + align:start position:0% +so they are continuous they can be taken + + + align:start position:0% +so they are continuous they can be taken +to be continuous functions of s because + + align:start position:0% +to be continuous functions of s because + + + align:start position:0% +to be continuous functions of s because +they are continuous functions of s as + + align:start position:0% +they are continuous functions of s as + + + align:start position:0% +they are continuous functions of s as +long as s is less than 1 minus toao s is + + align:start position:0% +long as s is less than 1 minus toao s is + + + align:start position:0% +long as s is less than 1 minus toao s is +bounded away from zero so we reach 1 + + align:start position:0% +bounded away from zero so we reach 1 + + + align:start position:0% +bounded away from zero so we reach 1 +minus towa in finitely many steps + + align:start position:0% + + + + align:start position:0% + +Maybe let's write this here because it's + + align:start position:0% +Maybe let's write this here because it's + + + align:start position:0% +Maybe let's write this here because it's +important. So epsilon + + align:start position:0% +important. So epsilon + + + align:start position:0% +important. So epsilon +is or can be taken continuous + + align:start position:0% + + + + align:start position:0% + +uh function of + + align:start position:0% +uh function of + + + align:start position:0% +uh function of +s. + + align:start position:0% + + + + align:start position:0% + +So remains + + align:start position:0% + + + + align:start position:0% + +bounded below + + align:start position:0% + + + + align:start position:0% + +as long as s is bounded away from one. + + align:start position:0% + + + + align:start position:0% + +So we can do we can achieve this by + + align:start position:0% +So we can do we can achieve this by + + + align:start position:0% +So we can do we can achieve this by +iterating finally many times. + + align:start position:0% +iterating finally many times. + + + align:start position:0% +iterating finally many times. +[Applause] + + align:start position:0% + + + + align:start position:0% + +Okay. And why is this good? Because this + + align:start position:0% +Okay. And why is this good? Because this + + + align:start position:0% +Okay. And why is this good? Because this +allows us to do instead of a plus little + + align:start position:0% +allows us to do instead of a plus little + + + align:start position:0% +allows us to do instead of a plus little +a a now we can do x plus little ax where + + align:start position:0% +a a now we can do x plus little ax where + + + align:start position:0% +a a now we can do x plus little ax where +x is potentially much bigger than a. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So the next step + + align:start position:0% +So the next step + + + align:start position:0% +So the next step +and I think this step is the same as in + + align:start position:0% +and I think this step is the same as in + + + align:start position:0% +and I think this step is the same as in +define a field setting. So I'm basically + + align:start position:0% +define a field setting. So I'm basically + + + align:start position:0% +define a field setting. So I'm basically +just going to state it. Uh if x + + align:start position:0% +just going to state it. Uh if x + + + align:start position:0% +just going to state it. Uh if x +is a delta t uh okay x in 01 still + + align:start position:0% + + + + align:start position:0% + +and x is a delta + + align:start position:0% +and x is a delta + + + align:start position:0% +and x is a delta +uh maybe let's call it u. So u is going + + align:start position:0% +uh maybe let's call it u. So u is going + + + align:start position:0% +uh maybe let's call it u. So u is going +to be t / 2 soon. uh delta minus epsilon + + align:start position:0% +to be t / 2 soon. uh delta minus epsilon + + + align:start position:0% +to be t / 2 soon. uh delta minus epsilon +set + + align:start position:0% + + + + align:start position:0% + +and a + + align:start position:0% +and a + + + align:start position:0% +and a +is 01 + + align:start position:0% + + + + align:start position:0% + +is a delta s maybe let's write ea here + + align:start position:0% +is a delta s maybe let's write ea here + + + align:start position:0% +is a delta s maybe let's write ea here +for consistency delta to the minus ea + + align:start position:0% +for consistency delta to the minus ea + + + align:start position:0% +for consistency delta to the minus ea +set. So now instead of one set we have + + align:start position:0% +set. So now instead of one set we have + + + align:start position:0% +set. So now instead of one set we have +two sets potentially of very different + + align:start position:0% +two sets potentially of very different + + + align:start position:0% +two sets potentially of very different +sizes and okay they are both strictly + + align:start position:0% +sizes and okay they are both strictly + + + align:start position:0% +sizes and okay they are both strictly +bigger than zero and strictly less than + + align:start position:0% +bigger than zero and strictly less than + + + align:start position:0% +bigger than zero and strictly less than +one and the interesting case + + align:start position:0% +one and the interesting case + + + align:start position:0% +one and the interesting case +is when s is less than u. So this is the + + align:start position:0% +is when s is less than u. So this is the + + + align:start position:0% +is when s is less than u. So this is the +case that that we don't already know. + + align:start position:0% + + + + align:start position:0% + +Then there exists little a in a + + align:start position:0% +Then there exists little a in a + + + align:start position:0% +Then there exists little a in a +such that x plus little ax grows. + + align:start position:0% + + + + align:start position:0% + +It grows by some epsilon that depends on + + align:start position:0% +It grows by some epsilon that depends on + + + align:start position:0% +It grows by some epsilon that depends on +s and u + + align:start position:0% + + + + align:start position:0% + +Okay. So uh just briefly so the idea and + + align:start position:0% +Okay. So uh just briefly so the idea and + + + align:start position:0% +Okay. So uh just briefly so the idea and +again I think you've seen this in the + + align:start position:0% +again I think you've seen this in the + + + align:start position:0% +again I think you've seen this in the +final setting but the idea is that it's + + align:start position:0% +final setting but the idea is that it's + + + align:start position:0% +final setting but the idea is that it's +true + + align:start position:0% +true + + + align:start position:0% +true +for + + align:start position:0% +for + + + align:start position:0% +for +maybe not for a but is true for Q to of + + align:start position:0% +maybe not for a but is true for Q to of + + + align:start position:0% +maybe not for a but is true for Q to of +a + + align:start position:0% + + + + align:start position:0% + +and here you have to take toao uh so + + align:start position:0% +and here you have to take toao uh so + + + align:start position:0% +and here you have to take toao uh so +that q to a is bigger than X. + + align:start position:0% +that q to a is bigger than X. + + + align:start position:0% +that q to a is bigger than X. +So we can take toao for example to be 1 + + align:start position:0% +So we can take toao for example to be 1 + + + align:start position:0% +So we can take toao for example to be 1 +- U / 2 + + align:start position:0% +- U / 2 + + + align:start position:0% +- U / 2 +something like this. Then this is much + + align:start position:0% +something like this. Then this is much + + + align:start position:0% +something like this. Then this is much +bigger than X in size. So these are sets + + align:start position:0% +bigger than X in size. So these are sets + + + align:start position:0% +bigger than X in size. So these are sets +but it has size much bigger than X. Once + + align:start position:0% +but it has size much bigger than X. Once + + + align:start position:0% +but it has size much bigger than X. Once +once uh the set of directions has size + + align:start position:0% +once uh the set of directions has size + + + align:start position:0% +once uh the set of directions has size +much bigger than X we can do double + + align:start position:0% +much bigger than X we can do double + + + align:start position:0% +much bigger than X we can do double +counting and get growth with this + + align:start position:0% +counting and get growth with this + + + align:start position:0% +counting and get growth with this +instead of this. But once we get growth + + align:start position:0% +instead of this. But once we get growth + + + align:start position:0% +instead of this. But once we get growth +for a polomial instead of a we apply + + align:start position:0% +for a polomial instead of a we apply + + + align:start position:0% +for a polomial instead of a we apply +pruna one million times and we go back + + align:start position:0% +pruna one million times and we go back + + + align:start position:0% +pruna one million times and we go back +down to a. + + align:start position:0% + + + + align:start position:0% + +Okay. and then apply + + align:start position:0% +Okay. and then apply + + + align:start position:0% +Okay. and then apply +plunic + + align:start position:0% +plunic + + + align:start position:0% +plunic +triangle inequality + + align:start position:0% +triangle inequality + + + align:start position:0% +triangle inequality +double counting + + align:start position:0% + + + + align:start position:0% + +and then it is also true for a. + + align:start position:0% + + + + align:start position:0% + +So this part is really exactly the same. + + align:start position:0% +So this part is really exactly the same. + + + align:start position:0% +So this part is really exactly the same. +So we already had to go from Q of A to + + align:start position:0% +So we already had to go from Q of A to + + + align:start position:0% +So we already had to go from Q of A to +to little A uh before. So initially we + + align:start position:0% +to little A uh before. So initially we + + + align:start position:0% +to little A uh before. So initially we +proved that A a minus A a is bigger than + + align:start position:0% +proved that A a minus A a is bigger than + + + align:start position:0% +proved that A a minus A a is bigger than +A and we use that to show that A plus + + align:start position:0% +A and we use that to show that A plus + + + align:start position:0% +A and we use that to show that A plus +little A is bigger than A. So it's the + + align:start position:0% +little A is bigger than A. So it's the + + + align:start position:0% +little A is bigger than A. So it's the +same the same reduction here and I think + + align:start position:0% +same the same reduction here and I think + + + align:start position:0% +same the same reduction here and I think +you've seen something very similar in + + align:start position:0% +you've seen something very similar in + + + align:start position:0% +you've seen something very similar in +the finite field setting and modular + + align:start position:0% +the finite field setting and modular + + + align:start position:0% +the finite field setting and modular +technical details. This part is the + + align:start position:0% +technical details. This part is the + + + align:start position:0% +technical details. This part is the +same. + + align:start position:0% +same. + + + align:start position:0% +same. +But in order to get here, it's important + + align:start position:0% +But in order to get here, it's important + + + align:start position:0% +But in order to get here, it's important +that we can make this set bigger than x. + + align:start position:0% +that we can make this set bigger than x. + + + align:start position:0% +that we can make this set bigger than x. +This is what we wanted to iterate. + + align:start position:0% + + + + align:start position:0% + +Potentially x is much bigger than a. But + + align:start position:0% +Potentially x is much bigger than a. But + + + align:start position:0% +Potentially x is much bigger than a. But +we can expand a by a polomial so that it + + align:start position:0% +we can expand a by a polomial so that it + + + align:start position:0% +we can expand a by a polomial so that it +becomes bigger than x. And for this we + + align:start position:0% +becomes bigger than x. And for this we + + + align:start position:0% +becomes bigger than x. And for this we +have to iterate. This is why we worried + + align:start position:0% +have to iterate. This is why we worried + + + align:start position:0% +have to iterate. This is why we worried +so much about iterating. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Okay, the next step is to + + align:start position:0% +Okay, the next step is to + + + align:start position:0% +Okay, the next step is to +prove Bans projection theorem. + + align:start position:0% + + + + align:start position:0% + +Okay, I'm not going to do the whole + + align:start position:0% +Okay, I'm not going to do the whole + + + align:start position:0% +Okay, I'm not going to do the whole +proof, but just basically recall what it + + align:start position:0% +proof, but just basically recall what it + + + align:start position:0% +proof, but just basically recall what it +is in the final setting and explain + + align:start position:0% +is in the final setting and explain + + + align:start position:0% +is in the final setting and explain +again where one where one has to be a + + align:start position:0% +again where one where one has to be a + + + align:start position:0% +again where one where one has to be a +little bit careful, but hopefully by now + + align:start position:0% +little bit careful, but hopefully by now + + + align:start position:0% +little bit careful, but hopefully by now +you will not be so worried about the + + align:start position:0% +you will not be so worried about the + + + align:start position:0% +you will not be so worried about the +part where we have to be careful. So + + align:start position:0% +part where we have to be careful. So + + + align:start position:0% +part where we have to be careful. So +proof of region theorem. + + align:start position:0% + + + + align:start position:0% + +Okay. Now I regret calling this xx but + + align:start position:0% +Okay. Now I regret calling this xx but + + + align:start position:0% +Okay. Now I regret calling this xx but +it's too late. + + align:start position:0% +it's too late. + + + align:start position:0% +it's too late. +So let x be uh in the unit b 2 + + align:start position:0% + + + + align:start position:0% + +delta t delta t the minus ea set where + + align:start position:0% +delta t delta t the minus ea set where + + + align:start position:0% +delta t delta t the minus ea set where +ea is very very small and t is between + + align:start position:0% +ea is very very small and t is between + + + align:start position:0% +ea is very very small and t is between +zero and two. + + align:start position:0% + + + + align:start position:0% + +Let d be a set of directions + + align:start position:0% + + + + align:start position:0% + +which is a delta s delta to the minus ea + + align:start position:0% +which is a delta s delta to the minus ea + + + align:start position:0% +which is a delta s delta to the minus ea +set + + align:start position:0% + + + + align:start position:0% + +and what is the goal? + + align:start position:0% +and what is the goal? + + + align:start position:0% +and what is the goal? +So what is the claim of protection + + align:start position:0% +So what is the claim of protection + + + align:start position:0% +So what is the claim of protection +theorem? It is that there exists some a + + align:start position:0% +theorem? It is that there exists some a + + + align:start position:0% +theorem? It is that there exists some a +in d + + align:start position:0% +in d + + + align:start position:0% +in d +such that pi a + + align:start position:0% +such that pi a + + + align:start position:0% +such that pi a +of g + + align:start position:0% + + + + align:start position:0% + +exceeds the trivial bound by some + + align:start position:0% +exceeds the trivial bound by some + + + align:start position:0% +exceeds the trivial bound by some +epsilon + + align:start position:0% + + + + align:start position:0% + +and the trivial bound is the + + align:start position:0% +and the trivial bound is the + + + align:start position:0% +and the trivial bound is the +square root of the delta. Okay, sorry. + + align:start position:0% +square root of the delta. Okay, sorry. + + + align:start position:0% +square root of the delta. Okay, sorry. +In the version we are that I stated the + + align:start position:0% +In the version we are that I stated the + + + align:start position:0% +In the version we are that I stated the +size of X is delta to the minus T. So it + + align:start position:0% +size of X is delta to the minus T. So it + + + align:start position:0% +size of X is delta to the minus T. So it +matches the non concentration condition. + + align:start position:0% + + + + align:start position:0% + +So here we can just write delta t the + + align:start position:0% +So here we can just write delta t the + + + align:start position:0% +So here we can just write delta t the +minus t / two. This is the square root + + align:start position:0% +minus t / two. This is the square root + + + align:start position:0% +minus t / two. This is the square root +of the size of x which is the trivial + + align:start position:0% +of the size of x which is the trivial + + + align:start position:0% +of the size of x which is the trivial +bound and we exceed it by some delta to + + align:start position:0% +bound and we exceed it by some delta to + + + align:start position:0% +bound and we exceed it by some delta to +the minus epsilon. And this is true for + + align:start position:0% +the minus epsilon. And this is true for + + + align:start position:0% +the minus epsilon. And this is true for +every g which is dense in a * a. + + align:start position:0% + + + + align:start position:0% + +Okay. So this is projection theorem. + + align:start position:0% +Okay. So this is projection theorem. + + + align:start position:0% +Okay. So this is projection theorem. +This is what we want to prove. + + align:start position:0% +This is what we want to prove. + + + align:start position:0% +This is what we want to prove. +Okay. So uh in the finite setting I + + align:start position:0% +Okay. So uh in the finite setting I + + + align:start position:0% +Okay. So uh in the finite setting I +think to prove a similar statement uh + + align:start position:0% +think to prove a similar statement uh + + + align:start position:0% +think to prove a similar statement uh +what you did is first consider three fix + + align:start position:0% +what you did is first consider three fix + + + align:start position:0% +what you did is first consider three fix +well just pick three directions in D + + align:start position:0% +well just pick three directions in D + + + align:start position:0% +well just pick three directions in D +in order to apply hours. So again it's + + align:start position:0% +in order to apply hours. So again it's + + + align:start position:0% +in order to apply hours. So again it's +similar to what we did before. Either + + align:start position:0% +similar to what we did before. Either + + + align:start position:0% +similar to what we did before. Either +things already work or we can apply + + align:start position:0% +things already work or we can apply + + + align:start position:0% +things already work or we can apply +hours. Here we have to be careful about + + align:start position:0% +hours. Here we have to be careful about + + + align:start position:0% +hours. Here we have to be careful about +how we choose the three directions. + + align:start position:0% +how we choose the three directions. + + + align:start position:0% +how we choose the three directions. +Uh because if the three directions that + + align:start position:0% +Uh because if the three directions that + + + align:start position:0% +Uh because if the three directions that +we choose are very close to each other + + align:start position:0% +we choose are very close to each other + + + align:start position:0% +we choose are very close to each other +uh this is going to be bad news. We are + + align:start position:0% +uh this is going to be bad news. We are + + + align:start position:0% +uh this is going to be bad news. We are +going to lose a lot. + + align:start position:0% +going to lose a lot. + + + align:start position:0% +going to lose a lot. +So um well even though this is in 01 we + + align:start position:0% +So um well even though this is in 01 we + + + align:start position:0% +So um well even though this is in 01 we +can sort of change coordinates + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +so that 0 1 and infinity are in D + + align:start position:0% +so that 0 1 and infinity are in D + + + align:start position:0% +so that 0 1 and infinity are in D +and this can be done in a way where we + + align:start position:0% +and this can be done in a way where we + + + align:start position:0% +and this can be done in a way where we +don't lose too much using that D is + + align:start position:0% +don't lose too much using that D is + + + align:start position:0% +don't lose too much using that D is +spread out + + align:start position:0% +spread out + + + align:start position:0% +spread out +Because of these non-conentration + + align:start position:0% +Because of these non-conentration + + + align:start position:0% +Because of these non-conentration +conditions, + + align:start position:0% +conditions, + + + align:start position:0% +conditions, +there are three points in D which are + + align:start position:0% +there are three points in D which are + + + align:start position:0% +there are three points in D which are +far apart from each other. But that + + align:start position:0% +far apart from each other. But that + + + align:start position:0% +far apart from each other. But that +means that if we send these three points + + align:start position:0% +means that if we send these three points + + + align:start position:0% +means that if we send these three points +that are far apart from each other to 0, + + align:start position:0% +that are far apart from each other to 0, + + + align:start position:0% +that are far apart from each other to 0, +one infinity. So the are really the + + align:start position:0% +one infinity. So the are really the + + + align:start position:0% +one infinity. So the are really the +slopes. They are not the angles, they + + align:start position:0% +slopes. They are not the angles, they + + + align:start position:0% +slopes. They are not the angles, they +are slopes. So uh so this can be done + + align:start position:0% + + + + align:start position:0% + +with a linear change of coordinates. + + align:start position:0% + + + + align:start position:0% + +of distortion. + + align:start position:0% + + + + align:start position:0% + +So the distortion is the norm of the + + align:start position:0% +So the distortion is the norm of the + + + align:start position:0% +So the distortion is the norm of the +corresponding matrix + + align:start position:0% +corresponding matrix + + + align:start position:0% +corresponding matrix +delta to the minus O of EA. + + align:start position:0% +delta to the minus O of EA. + + + align:start position:0% +delta to the minus O of EA. +So this distortion is because EA is much + + align:start position:0% +So this distortion is because EA is much + + + align:start position:0% +So this distortion is because EA is much +smaller than epsilon. + + align:start position:0% +smaller than epsilon. + + + align:start position:0% +smaller than epsilon. +If we have a gain, + + align:start position:0% +If we have a gain, + + + align:start position:0% +If we have a gain, +well we have to decrease the gain by + + align:start position:0% +well we have to decrease the gain by + + + align:start position:0% +well we have to decrease the gain by +what we lose in this range of + + align:start position:0% +what we lose in this range of + + + align:start position:0% +what we lose in this range of +coordinates. But this is mild. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +>> A to be like pi 0 + + align:start position:0% +>> A to be like pi 0 + + + align:start position:0% +>> A to be like pi 0 +x. + + align:start position:0% +x. + + + align:start position:0% +x. +>> We Yeah, we are going to look at the + + align:start position:0% +>> We Yeah, we are going to look at the + + + align:start position:0% +>> We Yeah, we are going to look at the +vertical and horizontal projections of x + + align:start position:0% +vertical and horizontal projections of x + + + align:start position:0% +vertical and horizontal projections of x +and and the the pi one of x. Yeah, I'm + + align:start position:0% +and and the the pi one of x. Yeah, I'm + + + align:start position:0% +and and the the pi one of x. Yeah, I'm +just saying there's X and A in the + + align:start position:0% +just saying there's X and A in the + + + align:start position:0% +just saying there's X and A in the +>> Oh, sorry. Uh, + + align:start position:0% + + + + align:start position:0% + +>> sorry. In X in X. Sorry. + + align:start position:0% +>> sorry. In X in X. Sorry. + + + align:start position:0% +>> sorry. In X in X. Sorry. +>> X + + align:start position:0% +>> X + + + align:start position:0% +>> X +in X. X. X is in R2 + + align:start position:0% + + + + align:start position:0% + +>> in X. + + align:start position:0% +>> in X. + + + align:start position:0% +>> in X. +>> X is in X is a two dimensional object. + + align:start position:0% +>> X is in X is a two dimensional object. + + + align:start position:0% +>> X is in X is a two dimensional object. +>> And the point is you want to try to + + align:start position:0% +>> And the point is you want to try to + + + align:start position:0% +>> And the point is you want to try to +prove this using a= 0 infinity X. + + align:start position:0% +prove this using a= 0 infinity X. + + + align:start position:0% +prove this using a= 0 infinity X. +Yes. Yeah, that's the point. But yeah, + + align:start position:0% +Yes. Yeah, that's the point. But yeah, + + + align:start position:0% +Yes. Yeah, that's the point. But yeah, +so sorry there was a typo here. So x is + + align:start position:0% +so sorry there was a typo here. So x is + + + align:start position:0% +so sorry there was a typo here. So x is +already two dimensional in what we have + + align:start position:0% +already two dimensional in what we have + + + align:start position:0% +already two dimensional in what we have +been doing. We have a cartitionian + + align:start position:0% +been doing. We have a cartitionian + + + align:start position:0% +been doing. We have a cartitionian +product or here we have a cartitionian. + + align:start position:0% +product or here we have a cartitionian. + + + align:start position:0% +product or here we have a cartitionian. +Okay, bad board management again. Now + + align:start position:0% +Okay, bad board management again. Now + + + align:start position:0% +Okay, bad board management again. Now +it's hidden. So okay, we want to apply + + align:start position:0% +it's hidden. So okay, we want to apply + + + align:start position:0% +it's hidden. So okay, we want to apply +this which unfortunately is going to be + + align:start position:0% +this which unfortunately is going to be + + + align:start position:0% +this which unfortunately is going to be +hidden. Okay, so x this x is going to be + + align:start position:0% +hidden. Okay, so x this x is going to be + + + align:start position:0% +hidden. Okay, so x this x is going to be +some like the projection of x horizontal + + align:start position:0% +some like the projection of x horizontal + + + align:start position:0% +some like the projection of x horizontal +projection of the x in R2. + + align:start position:0% +projection of the x in R2. + + + align:start position:0% +projection of the x in R2. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So it's really similar to the final + + align:start position:0% +So it's really similar to the final + + + align:start position:0% +So it's really similar to the final +field setting. So I'm I'm going to I'm + + align:start position:0% +field setting. So I'm I'm going to I'm + + + align:start position:0% +field setting. So I'm I'm going to I'm +skipping details. I'm going to continue + + align:start position:0% +skipping details. I'm going to continue + + + align:start position:0% +skipping details. I'm going to continue +skipping details mostly focusing on the + + align:start position:0% +skipping details mostly focusing on the + + + align:start position:0% +skipping details mostly focusing on the +differences. So one difference is that + + align:start position:0% +differences. So one difference is that + + + align:start position:0% +differences. So one difference is that +we have to be careful with the three + + align:start position:0% +we have to be careful with the three + + + align:start position:0% +we have to be careful with the three +directions that we take. If they are too + + align:start position:0% +directions that we take. If they are too + + + align:start position:0% +directions that we take. If they are too +close to each other, the distortion will + + align:start position:0% +close to each other, the distortion will + + + align:start position:0% +close to each other, the distortion will +be too large and we will it can be so + + align:start position:0% +be too large and we will it can be so + + + align:start position:0% +be too large and we will it can be so +large that we lose all the gain. But + + align:start position:0% +large that we lose all the gain. But + + + align:start position:0% +large that we lose all the gain. But +because the set of directions is spread + + align:start position:0% +because the set of directions is spread + + + align:start position:0% +because the set of directions is spread +out by the non-conentration condition, + + align:start position:0% +out by the non-conentration condition, + + + align:start position:0% +out by the non-conentration condition, +we can do it in such a way that the + + align:start position:0% +we can do it in such a way that the + + + align:start position:0% +we can do it in such a way that the +distortion is controlled. + + align:start position:0% + + + + align:start position:0% + +Okay. So now x is contained in x1 * x2 + + align:start position:0% +Okay. So now x is contained in x1 * x2 + + + align:start position:0% +Okay. So now x is contained in x1 * x2 +where this is the + + align:start position:0% +where this is the + + + align:start position:0% +where this is the +horizontal projection and this is the + + align:start position:0% +horizontal projection and this is the + + + align:start position:0% +horizontal projection and this is the +vertical projection. + + align:start position:0% + + + + align:start position:0% + +So uh if because we are assuming that + + align:start position:0% +So uh if because we are assuming that + + + align:start position:0% +So uh if because we are assuming that +also one + + align:start position:0% +also one + + + align:start position:0% +also one +is in d. If one works we are done + + align:start position:0% +is in d. If one works we are done + + + align:start position:0% +is in d. If one works we are done +because we are trying to show that + + align:start position:0% +because we are trying to show that + + + align:start position:0% +because we are trying to show that +something works. So the claim is that + + align:start position:0% +something works. So the claim is that + + + align:start position:0% +something works. So the claim is that +there exist an a and d with this + + align:start position:0% +there exist an a and d with this + + + align:start position:0% +there exist an a and d with this +property. So if we are so lucky that one + + align:start position:0% +property. So if we are so lucky that one + + + align:start position:0% +property. So if we are so lucky that one +has this property we are done. + + align:start position:0% + + + + align:start position:0% + +if one doesn't work. + + align:start position:0% +if one doesn't work. + + + align:start position:0% +if one doesn't work. +So this is very similar to what we did a + + align:start position:0% +So this is very similar to what we did a + + + align:start position:0% +So this is very similar to what we did a +bit earlier but somehow we have to do it + + align:start position:0% +bit earlier but somehow we have to do it + + + align:start position:0% +bit earlier but somehow we have to do it +twice. Once to do the iteration for a + + align:start position:0% +twice. Once to do the iteration for a + + + align:start position:0% +twice. Once to do the iteration for a +plus e aa and then again to conclude the + + align:start position:0% +plus e aa and then again to conclude the + + + align:start position:0% +plus e aa and then again to conclude the +proof. If one doesn't work then there + + align:start position:0% +proof. If one doesn't work then there + + + align:start position:0% +proof. If one doesn't work then there +exists some g + + align:start position:0% +exists some g + + + align:start position:0% +exists some g +which is dense in x1 * x2. + + align:start position:0% + + + + align:start position:0% + +Okay, sorry. Why is it dancing X1? + + align:start position:0% +Okay, sorry. Why is it dancing X1? + + + align:start position:0% +Okay, sorry. Why is it dancing X1? +Ah, + + align:start position:0% + + + + align:start position:0% + +okay. Actually, uh, + + align:start position:0% +okay. Actually, uh, + + + align:start position:0% +okay. Actually, uh, +yeah, this is more complicated. So, one + + align:start position:0% +yeah, this is more complicated. So, one + + + align:start position:0% +yeah, this is more complicated. So, one +has to be careful. So, okay. So, um, + + align:start position:0% + + + + align:start position:0% + +okay. So I want to assume that X1 + + align:start position:0% +okay. So I want to assume that X1 + + + align:start position:0% +okay. So I want to assume that X1 +has size roughly square root of the size + + align:start position:0% +has size roughly square root of the size + + + align:start position:0% +has size roughly square root of the size +of X with the idea that if he had size + + align:start position:0% +of X with the idea that if he had size + + + align:start position:0% +of X with the idea that if he had size +bigger than the size of X we would win. + + align:start position:0% +bigger than the size of X we would win. + + + align:start position:0% +bigger than the size of X we would win. +But in fact in order to reach this + + align:start position:0% +But in fact in order to reach this + + + align:start position:0% +But in fact in order to reach this +conclusion we have to apply the G + + align:start position:0% +conclusion we have to apply the G + + + align:start position:0% +conclusion we have to apply the G +already because the conclusion we want + + align:start position:0% +already because the conclusion we want + + + align:start position:0% +already because the conclusion we want +is not only that the projection of X + + align:start position:0% +is not only that the projection of X + + + align:start position:0% +is not only that the projection of X +grows but the projection of every dense + + align:start position:0% +grows but the projection of every dense + + + align:start position:0% +grows but the projection of every dense +subset of X works. So + + align:start position:0% +subset of X works. So + + + align:start position:0% +subset of X works. So +okay so what one really has to do is + + align:start position:0% +okay so what one really has to do is + + + align:start position:0% +okay so what one really has to do is +apply + + align:start position:0% +apply + + + align:start position:0% +apply +hours three times. So for zero one and + + align:start position:0% +hours three times. So for zero one and + + + align:start position:0% +hours three times. So for zero one and +maybe for zero infinity and one in this + + align:start position:0% +maybe for zero infinity and one in this + + + align:start position:0% +maybe for zero infinity and one in this +order either it works or we apply + + align:start position:0% +order either it works or we apply + + + align:start position:0% +order either it works or we apply +hours + + align:start position:0% +hours + + + align:start position:0% +hours +to replace x by x prime and then xp + + align:start position:0% +to replace x by x prime and then xp + + + align:start position:0% +to replace x by x prime and then xp +prime and then x triple prime. Okay, I'm + + align:start position:0% +prime and then x triple prime. Okay, I'm + + + align:start position:0% +prime and then x triple prime. Okay, I'm +not going to do all of the details, but + + align:start position:0% +not going to do all of the details, but + + + align:start position:0% +not going to do all of the details, but +uh + + align:start position:0% +uh + + + align:start position:0% +uh +did something like this happen in the + + align:start position:0% +did something like this happen in the + + + align:start position:0% +did something like this happen in the +final field setting? I think it also + + align:start position:0% +final field setting? I think it also + + + align:start position:0% +final field setting? I think it also +this part has to be done in the final + + align:start position:0% +this part has to be done in the final + + + align:start position:0% +this part has to be done in the final +field setting. + + align:start position:0% +field setting. + + + align:start position:0% +field setting. +So + + align:start position:0% +So + + + align:start position:0% +So +>> we didn't we didn't do this stronger + + align:start position:0% +>> we didn't we didn't do this stronger + + + align:start position:0% +>> we didn't we didn't do this stronger +version in detail. + + align:start position:0% +version in detail. + + + align:start position:0% +version in detail. +>> Oh, okay. So you didn't do the strong + + align:start position:0% +>> Oh, okay. So you didn't do the strong + + + align:start position:0% +>> Oh, okay. So you didn't do the strong +version in detail. Okay. Uh also I'm not + + align:start position:0% +version in detail. Okay. Uh also I'm not + + + align:start position:0% +version in detail. Okay. Uh also I'm not +going to do the strong version in detail + + align:start position:0% +going to do the strong version in detail + + + align:start position:0% +going to do the strong version in detail +uh because the 20 minutes I expected to + + align:start position:0% +uh because the 20 minutes I expected to + + + align:start position:0% +uh because the 20 minutes I expected to +take are turning into the whole lecture + + align:start position:0% +take are turning into the whole lecture + + + align:start position:0% +take are turning into the whole lecture +again. Uh but I'm leaving today. So now + + align:start position:0% +again. Uh but I'm leaving today. So now + + + align:start position:0% +again. Uh but I'm leaving today. So now +I really have to finish it over the next + + align:start position:0% +I really have to finish it over the next + + + align:start position:0% +I really have to finish it over the next +20 minutes. So okay so we okay either + + align:start position:0% +20 minutes. So okay so we okay either + + + align:start position:0% +20 minutes. So okay so we okay either +zero one or infinity or I guess zero + + align:start position:0% +zero one or infinity or I guess zero + + + align:start position:0% +zero one or infinity or I guess zero +infinity + + align:start position:0% +infinity + + + align:start position:0% +infinity +or one + + align:start position:0% +or one + + + align:start position:0% +or one +work + + align:start position:0% +work + + + align:start position:0% +work +or + + align:start position:0% +or + + + align:start position:0% +or +in each case + + align:start position:0% + + + + align:start position:0% + +we can apply + + align:start position:0% +we can apply + + + align:start position:0% +we can apply +valuetic words + + align:start position:0% + + + + align:start position:0% + +and pass to subs to dense subsets of X + + align:start position:0% + + + + align:start position:0% + +of X and the corresponding projections + + align:start position:0% +of X and the corresponding projections + + + align:start position:0% +of X and the corresponding projections +of X. + + align:start position:0% + + + + align:start position:0% + +So evalu + + align:start position:0% + + + + align:start position:0% + +if the horizontal projection + + align:start position:0% +if the horizontal projection + + + align:start position:0% +if the horizontal projection +has the property we want, we are done. + + align:start position:0% +has the property we want, we are done. + + + align:start position:0% +has the property we want, we are done. +Otherwise, there exist a dense subset of + + align:start position:0% +Otherwise, there exist a dense subset of + + + align:start position:0% +Otherwise, there exist a dense subset of +a with a small horizontal projection. + + align:start position:0% +a with a small horizontal projection. + + + align:start position:0% +a with a small horizontal projection. +But we can imagine that the horizontal + + align:start position:0% +But we can imagine that the horizontal + + + align:start position:0% +But we can imagine that the horizontal +projection is some other projection. So + + align:start position:0% +projection is some other projection. So + + + align:start position:0% +projection is some other projection. So +it's the same thing we did last time uh + + align:start position:0% +it's the same thing we did last time uh + + + align:start position:0% +it's the same thing we did last time uh +we did a bit earlier and then we have to + + align:start position:0% +we did a bit earlier and then we have to + + + align:start position:0% +we did a bit earlier and then we have to +replace x by some x prime and then by + + align:start position:0% +replace x by some x prime and then by + + + align:start position:0% +replace x by some x prime and then by +some xp prime and then by some x triple + + align:start position:0% +some xp prime and then by some x triple + + + align:start position:0% +some xp prime and then by some x triple +prime. So + + align:start position:0% + + + + align:start position:0% + +I'm not going to do it in detail. I'm + + align:start position:0% +I'm not going to do it in detail. I'm + + + align:start position:0% +I'm not going to do it in detail. I'm +sorry. Yeah, I see many of you are + + align:start position:0% +sorry. Yeah, I see many of you are + + + align:start position:0% +sorry. Yeah, I see many of you are +confused and that's okay because uh one + + align:start position:0% +confused and that's okay because uh one + + + align:start position:0% +confused and that's okay because uh one +has to do it carefully. It's not obvious + + align:start position:0% +has to do it carefully. It's not obvious + + + align:start position:0% +has to do it carefully. It's not obvious +how to do it but it can be done. Okay. + + align:start position:0% +how to do it but it can be done. Okay. + + + align:start position:0% +how to do it but it can be done. Okay. +Okay. So eventually + + align:start position:0% + + + + align:start position:0% + +after renaming the set back to X, + + align:start position:0% + + + + align:start position:0% + +we are in the following situation. + + align:start position:0% + + + + align:start position:0% + +This situation where + + align:start position:0% +This situation where + + + align:start position:0% +This situation where +Okay, let me just write it here. + + align:start position:0% + + + + align:start position:0% + +where the horizontal and vertical + + align:start position:0% +where the horizontal and vertical + + + align:start position:0% +where the horizontal and vertical +projections + + align:start position:0% + + + + align:start position:0% + +have size at most delta to the minus + + align:start position:0% +have size at most delta to the minus + + + align:start position:0% +have size at most delta to the minus +epsilon t / 2 + epsilon. + + align:start position:0% + + + + align:start position:0% + +Okay, I guess um let's say we apply + + align:start position:0% +Okay, I guess um let's say we apply + + + align:start position:0% +Okay, I guess um let's say we apply +valuic hours twice. Uh so we don't apply + + align:start position:0% +valuic hours twice. Uh so we don't apply + + + align:start position:0% +valuic hours twice. Uh so we don't apply +to pi one yet. + + align:start position:0% + + + + align:start position:0% + +Okay. And just to see how this goes. So + + align:start position:0% +Okay. And just to see how this goes. So + + + align:start position:0% +Okay. And just to see how this goes. So +suppose that uh pi one + + align:start position:0% +suppose that uh pi one + + + align:start position:0% +suppose that uh pi one +So suppose that one doesn't work. + + align:start position:0% +So suppose that one doesn't work. + + + align:start position:0% +So suppose that one doesn't work. +Suppose that one doesn't work. And that + + align:start position:0% +Suppose that one doesn't work. And that + + + align:start position:0% +Suppose that one doesn't work. And that +means that pi 1 of g uh doesn't grow + + align:start position:0% + + + + align:start position:0% + +for some dense subset of x. + + align:start position:0% +for some dense subset of x. + + + align:start position:0% +for some dense subset of x. +And if it's a dense subset of x, it is a + + align:start position:0% +And if it's a dense subset of x, it is a + + + align:start position:0% +And if it's a dense subset of x, it is a +dense subset of x1 * x2. This is x1. + + align:start position:0% +dense subset of x1 * x2. This is x1. + + + align:start position:0% +dense subset of x1 * x2. This is x1. +This is x2. + + align:start position:0% + + + + align:start position:0% + +So this is x1, this is x2. + + align:start position:0% + + + + align:start position:0% + +Okay. Then we can apply valuic hours. So + + align:start position:0% +Okay. Then we can apply valuic hours. So + + + align:start position:0% +Okay. Then we can apply valuic hours. So +here you see that we are in the setting + + align:start position:0% +here you see that we are in the setting + + + align:start position:0% +here you see that we are in the setting +to apply hours. So we're going to apply + + align:start position:0% +to apply hours. So we're going to apply + + + align:start position:0% +to apply hours. So we're going to apply +hours. Okay. So uh it looks like after + + align:start position:0% +hours. Okay. So uh it looks like after + + + align:start position:0% +hours. Okay. So uh it looks like after +applying barometric hours lots of times + + align:start position:0% +applying barometric hours lots of times + + + align:start position:0% +applying barometric hours lots of times +and I skipped the details but you have + + align:start position:0% +and I skipped the details but you have + + + align:start position:0% +and I skipped the details but you have +to trust me that this can be done. We + + align:start position:0% +to trust me that this can be done. We + + + align:start position:0% +to trust me that this can be done. We +are in the setting where we can apply + + align:start position:0% +are in the setting where we can apply + + + align:start position:0% +are in the setting where we can apply +this and be done + + align:start position:0% +this and be done + + + align:start position:0% +this and be done +but not so fast. + + align:start position:0% +but not so fast. + + + align:start position:0% +but not so fast. +What's the issue? Why not so fast? + + align:start position:0% + + + + align:start position:0% + +So all of the part that I'm not + + align:start position:0% +So all of the part that I'm not + + + align:start position:0% +So all of the part that I'm not +explaining here, you also have to do it + + align:start position:0% +explaining here, you also have to do it + + + align:start position:0% +explaining here, you also have to do it +in the finite field setting. If you want + + align:start position:0% +in the finite field setting. If you want + + + align:start position:0% +in the finite field setting. If you want +to get the stronger statement that the + + align:start position:0% +to get the stronger statement that the + + + align:start position:0% +to get the stronger statement that the +projection of a dense subset grows, not + + align:start position:0% +projection of a dense subset grows, not + + + align:start position:0% +projection of a dense subset grows, not +then subset of the of the given set. If + + align:start position:0% +then subset of the of the given set. If + + + align:start position:0% +then subset of the of the given set. If +you want to prove that in the final + + align:start position:0% +you want to prove that in the final + + + align:start position:0% +you want to prove that in the final +field setting, you have to do this + + align:start position:0% +field setting, you have to do this + + + align:start position:0% +field setting, you have to do this +multiple values hours. So this is not a + + align:start position:0% +multiple values hours. So this is not a + + + align:start position:0% +multiple values hours. So this is not a +difference. Okay, you haven't done it in + + align:start position:0% +difference. Okay, you haven't done it in + + + align:start position:0% +difference. Okay, you haven't done it in +detail in the finite field setting. But + + align:start position:0% +detail in the finite field setting. But + + + align:start position:0% +detail in the finite field setting. But +this part is not a difference between + + align:start position:0% +this part is not a difference between + + + align:start position:0% +this part is not a difference between +the finite field setting and the ukian + + align:start position:0% +the finite field setting and the ukian + + + align:start position:0% +the finite field setting and the ukian +setting. + + align:start position:0% +setting. + + + align:start position:0% +setting. +But there is something which is a + + align:start position:0% +But there is something which is a + + + align:start position:0% +But there is something which is a +difference. So what what is the issue? + + align:start position:0% +difference. So what what is the issue? + + + align:start position:0% +difference. So what what is the issue? +Why can't we just apply? Okay, we we can + + align:start position:0% +Why can't we just apply? Okay, we we can + + + align:start position:0% +Why can't we just apply? Okay, we we can +apply this but why do we have to be + + align:start position:0% +apply this but why do we have to be + + + align:start position:0% +apply this but why do we have to be +careful about applying this? + + align:start position:0% + + + + align:start position:0% + +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +So if I balance separated we get like a + + align:start position:0% +So if I balance separated we get like a + + + align:start position:0% +So if I balance separated we get like a +prime cross a prime and then + + align:start position:0% +prime cross a prime and then + + + align:start position:0% +prime cross a prime and then +or + + align:start position:0% +or + + + align:start position:0% +or +call y cross y that covers a lot of g + + align:start position:0% +call y cross y that covers a lot of g + + + align:start position:0% +call y cross y that covers a lot of g +and then if I want to apply what's on + + align:start position:0% +and then if I want to apply what's on + + + align:start position:0% +and then if I want to apply what's on +the left board I would need to know that + + align:start position:0% +the left board I would need to know that + + + align:start position:0% +the left board I would need to know that +y is a delta u something x + + align:start position:0% +y is a delta u something x + + + align:start position:0% +y is a delta u something x +>> exactly so here we have a cartition + + align:start position:0% +>> exactly so here we have a cartition + + + align:start position:0% +>> exactly so here we have a cartition +product okay so one small issue is that + + align:start position:0% +product okay so one small issue is that + + + align:start position:0% +product okay so one small issue is that +instead of x1 * x1 we have x1 * x2 but + + align:start position:0% +instead of x1 * x1 we have x1 * x2 but + + + align:start position:0% +instead of x1 * x1 we have x1 * x2 but +this is not important the issue is that + + align:start position:0% +this is not important the issue is that + + + align:start position:0% +this is not important the issue is that +x1 One is a projection of X and we are + + align:start position:0% +x1 One is a projection of X and we are + + + align:start position:0% +x1 One is a projection of X and we are +assuming that the size is roughly the + + align:start position:0% +assuming that the size is roughly the + + + align:start position:0% +assuming that the size is roughly the +square root of the size of X. But why is + + align:start position:0% +square root of the size of X. But why is + + + align:start position:0% +square root of the size of X. But why is +it not concentrated? In order to apply + + align:start position:0% +it not concentrated? In order to apply + + + align:start position:0% +it not concentrated? In order to apply +this and conclude, we need to know that + + align:start position:0% +this and conclude, we need to know that + + + align:start position:0% +this and conclude, we need to know that +X is non concentrated with U equals to T + + align:start position:0% +X is non concentrated with U equals to T + + + align:start position:0% +X is non concentrated with U equals to T +/2. + + align:start position:0% + + + + align:start position:0% + +So it's is very similar to the issue + + align:start position:0% +So it's is very similar to the issue + + + align:start position:0% +So it's is very similar to the issue +that we had when we we needed to + + align:start position:0% +that we had when we we needed to + + + align:start position:0% +that we had when we we needed to +iterate. So we knew that a plus little + + align:start position:0% +iterate. So we knew that a plus little + + + align:start position:0% +iterate. So we knew that a plus little +aa is large but we didn't know that the + + align:start position:0% +aa is large but we didn't know that the + + + align:start position:0% +aa is large but we didn't know that the +non concentration condition also + + align:start position:0% +non concentration condition also + + + align:start position:0% +non concentration condition also +improves. It's a similar issue here. We + + align:start position:0% +improves. It's a similar issue here. We + + + align:start position:0% +improves. It's a similar issue here. We +know something about the size of these + + align:start position:0% +know something about the size of these + + + align:start position:0% +know something about the size of these +projections but apparently we don't know + + align:start position:0% +projections but apparently we don't know + + + align:start position:0% +projections but apparently we don't know +anything about the non concentration. + + align:start position:0% +anything about the non concentration. + + + align:start position:0% +anything about the non concentration. +We need these projections to be non + + align:start position:0% +We need these projections to be non + + + align:start position:0% +We need these projections to be non +concentrated. Okay. So + + align:start position:0% +concentrated. Okay. So + + + align:start position:0% +concentrated. Okay. So +maybe ignore all of these and just say + + align:start position:0% +maybe ignore all of these and just say + + + align:start position:0% +maybe ignore all of these and just say +the following. Using balmic hours many + + align:start position:0% +the following. Using balmic hours many + + + align:start position:0% +the following. Using balmic hours many +times in a clever way, we can reduce to + + align:start position:0% +times in a clever way, we can reduce to + + + align:start position:0% +times in a clever way, we can reduce to +the to the case where the set X is a + + align:start position:0% +the to the case where the set X is a + + + align:start position:0% +the to the case where the set X is a +product set. You can even assume it's a + + align:start position:0% +product set. You can even assume it's a + + + align:start position:0% +product set. You can even assume it's a +product set of something a self product + + align:start position:0% +product set of something a self product + + + align:start position:0% +product set of something a self product +set. So using many times we can assume + + align:start position:0% +set. So using many times we can assume + + + align:start position:0% +set. So using many times we can assume +that X is X1 * X2 + + align:start position:0% +that X is X1 * X2 + + + align:start position:0% +that X is X1 * X2 +and then using again. + + align:start position:0% +and then using again. + + + align:start position:0% +and then using again. +So BIC hours allows us to go back and + + align:start position:0% +So BIC hours allows us to go back and + + + align:start position:0% +So BIC hours allows us to go back and +forth between dense subsets and test + + align:start position:0% +forth between dense subsets and test + + + align:start position:0% +forth between dense subsets and test +everything. So this is what what allows + + align:start position:0% +everything. So this is what what allows + + + align:start position:0% +everything. So this is what what allows +us to do. So we can assume that this we + + align:start position:0% +us to do. So we can assume that this we + + + align:start position:0% +us to do. So we can assume that this we +are in a in in in a the setting of a + + align:start position:0% +are in a in in in a the setting of a + + + align:start position:0% +are in a in in in a the setting of a +product set and then we want to apply + + align:start position:0% +product set and then we want to apply + + + align:start position:0% +product set and then we want to apply +this + + align:start position:0% +this + + + align:start position:0% +this +but not so fast because we don't know + + align:start position:0% +but not so fast because we don't know + + + align:start position:0% +but not so fast because we don't know +that the projections satisfy the + + align:start position:0% +that the projections satisfy the + + + align:start position:0% +that the projections satisfy the +concentration assumption of priority. So + + align:start position:0% +concentration assumption of priority. So + + + align:start position:0% +concentration assumption of priority. So +we have this problem again. So it's very + + align:start position:0% +we have this problem again. So it's very + + + align:start position:0% +we have this problem again. So it's very +similar to the problem we had before and + + align:start position:0% +similar to the problem we had before and + + + align:start position:0% +similar to the problem we had before and +it is solved in a similar way but it has + + align:start position:0% +it is solved in a similar way but it has + + + align:start position:0% +it is solved in a similar way but it has +to be solved. So in some sense so you + + align:start position:0% +to be solved. So in some sense so you + + + align:start position:0% +to be solved. So in some sense so you +can think of it of it in this way. We + + align:start position:0% +can think of it of it in this way. We + + + align:start position:0% +can think of it of it in this way. We +say that t /2 is a triv trivial between + + align:start position:0% +say that t /2 is a triv trivial between + + + align:start position:0% +say that t /2 is a triv trivial between +codes bound for projections. What we + + align:start position:0% +codes bound for projections. What we + + + align:start position:0% +codes bound for projections. What we +have to show is that this trivial bound + + align:start position:0% +have to show is that this trivial bound + + + align:start position:0% +have to show is that this trivial bound +actually holds in the non-conentration + + align:start position:0% +actually holds in the non-conentration + + + align:start position:0% +actually holds in the non-conentration +sense. + + align:start position:0% +sense. + + + align:start position:0% +sense. +So we have to show that the projection. + + align:start position:0% +So we have to show that the projection. + + + align:start position:0% +So we have to show that the projection. +So here 0 1 and infinity are just + + align:start position:0% +So here 0 1 and infinity are just + + + align:start position:0% +So here 0 1 and infinity are just +generic projections. So we in fact if we + + align:start position:0% +generic projections. So we in fact if we + + + align:start position:0% +generic projections. So we in fact if we +picture three random points uh in D this + + align:start position:0% +picture three random points uh in D this + + + align:start position:0% +picture three random points uh in D this +will work because three random points + + align:start position:0% +will work because three random points + + + align:start position:0% +will work because three random points +will be separated. Three random points + + align:start position:0% +will be separated. Three random points + + + align:start position:0% +will be separated. Three random points +will not be too concentrated because of + + align:start position:0% +will not be too concentrated because of + + + align:start position:0% +will not be too concentrated because of +this. There are not too many points in + + align:start position:0% +this. There are not too many points in + + + align:start position:0% +this. There are not too many points in +in a single ball. So if you randomly + + align:start position:0% +in a single ball. So if you randomly + + + align:start position:0% +in a single ball. So if you randomly +sample three points in D + + align:start position:0% +sample three points in D + + + align:start position:0% +sample three points in D +the linear map that makes these points + + align:start position:0% +the linear map that makes these points + + + align:start position:0% +the linear map that makes these points +horizontal, vertical and diagonal will + + align:start position:0% +horizontal, vertical and diagonal will + + + align:start position:0% +horizontal, vertical and diagonal will +have small distortion. + + align:start position:0% +have small distortion. + + + align:start position:0% +have small distortion. +So we need to know that the random + + align:start position:0% +So we need to know that the random + + + align:start position:0% +So we need to know that the random +projection of X is a delta T /2 S set. + + align:start position:0% +projection of X is a delta T /2 S set. + + + align:start position:0% +projection of X is a delta T /2 S set. +In some sense the goal is to show that + + align:start position:0% +In some sense the goal is to show that + + + align:start position:0% +In some sense the goal is to show that +the random projection is a delta T /2 + + align:start position:0% +the random projection is a delta T /2 + + + align:start position:0% +the random projection is a delta T /2 +plus some gain S set. + + align:start position:0% +plus some gain S set. + + + align:start position:0% +plus some gain S set. +But to prove that we need to show that + + align:start position:0% +But to prove that we need to show that + + + align:start position:0% +But to prove that we need to show that +it satisfies the same thing but without + + align:start position:0% +it satisfies the same thing but without + + + align:start position:0% +it satisfies the same thing but without +the epsilon but the nonconentration + + align:start position:0% +the epsilon but the nonconentration + + + align:start position:0% +the epsilon but the nonconentration +version of that. + + align:start position:0% +version of that. + + + align:start position:0% +version of that. +And this can be done. It can be done in + + align:start position:0% +And this can be done. It can be done in + + + align:start position:0% +And this can be done. It can be done in +several ways. One way is a similar thing + + align:start position:0% +several ways. One way is a similar thing + + + align:start position:0% +several ways. One way is a similar thing +to what we have done today. + + align:start position:0% +to what we have done today. + + + align:start position:0% +to what we have done today. +Well today and last time but basically + + align:start position:0% +Well today and last time but basically + + + align:start position:0% +Well today and last time but basically +go from growth to non-conentration + + align:start position:0% + + + + align:start position:0% + +uh by uniformizing everything uh + + align:start position:0% +uh by uniformizing everything uh + + + align:start position:0% +uh by uniformizing everything uh +carefully + + align:start position:0% +carefully + + + align:start position:0% +carefully +and it can also be done by some careful + + align:start position:0% +and it can also be done by some careful + + + align:start position:0% +and it can also be done by some careful +double counting similar to but not + + align:start position:0% +double counting similar to but not + + + align:start position:0% +double counting similar to but not +exactly the same that you've done + + align:start position:0% +exactly the same that you've done + + + align:start position:0% +exactly the same that you've done +before. So there are several ways of + + align:start position:0% +before. So there are several ways of + + + align:start position:0% +before. So there are several ways of +doing it because it's like the easy case + + align:start position:0% +doing it because it's like the easy case + + + align:start position:0% +doing it because it's like the easy case +but but it has to be done. Okay. So + + align:start position:0% +but but it has to be done. Okay. So + + + align:start position:0% +but but it has to be done. Okay. So +maybe let's write that down. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +Okay, so we need a last fact. + + align:start position:0% + + + + align:start position:0% + +If x and d are + + align:start position:0% +If x and d are + + + align:start position:0% +If x and d are +as before + + align:start position:0% +as before + + + align:start position:0% +as before +as in bulans projection theorem + + align:start position:0% + + + + align:start position:0% + +then there exists some a and d and once + + align:start position:0% +then there exists some a and d and once + + + align:start position:0% +then there exists some a and d and once +again once there is one once we know + + align:start position:0% +again once there is one once we know + + + align:start position:0% +again once there is one once we know +that there is one a and d that means + + align:start position:0% +that there is one a and d that means + + + align:start position:0% +that there is one a and d that means +nearly all a and d have this property + + align:start position:0% +nearly all a and d have this property + + + align:start position:0% +nearly all a and d have this property +such that by a of x contains a delta t + + align:start position:0% +such that by a of x contains a delta t + + + align:start position:0% +such that by a of x contains a delta t +/2 + + align:start position:0% +/2 + + + align:start position:0% +/2 +Delta 2 maybe all of epsilon or va + + align:start position:0% +Delta 2 maybe all of epsilon or va + + + align:start position:0% +Delta 2 maybe all of epsilon or va +set + + align:start position:0% + + + + align:start position:0% + +again t /2 is like the trivial bound but + + align:start position:0% +again t /2 is like the trivial bound but + + + align:start position:0% +again t /2 is like the trivial bound but +it's not so trivial in this case because + + align:start position:0% +it's not so trivial in this case because + + + align:start position:0% +it's not so trivial in this case because +we are claiming some non-conentration + + align:start position:0% +we are claiming some non-conentration + + + align:start position:0% +we are claiming some non-conentration +for the projection but because at the + + align:start position:0% +for the projection but because at the + + + align:start position:0% +for the projection but because at the +same time + + align:start position:0% +same time + + + align:start position:0% +same time +for covering number so for the covering + + align:start position:0% +for covering number so for the covering + + + align:start position:0% +for covering number so for the covering +number version of this is is sort of + + align:start position:0% +number version of this is is sort of + + + align:start position:0% +number version of this is is sort of +obvious because again if we have one set + + align:start position:0% +obvious because again if we have one set + + + align:start position:0% +obvious because again if we have one set +you look at two projections + + align:start position:0% +you look at two projections + + + align:start position:0% +you look at two projections +in more or less orthogonal directions + + align:start position:0% +in more or less orthogonal directions + + + align:start position:0% +in more or less orthogonal directions +and most one of them can drop by more + + align:start position:0% +and most one of them can drop by more + + + align:start position:0% +and most one of them can drop by more +than square root of the size of the set + + align:start position:0% +than square root of the size of the set + + + align:start position:0% +than square root of the size of the set +and this is true at every scale. + + align:start position:0% +and this is true at every scale. + + + align:start position:0% +and this is true at every scale. +So you see that if we knew that this is + + align:start position:0% +So you see that if we knew that this is + + + align:start position:0% +So you see that if we knew that this is +uniform we would be done. So it's really + + align:start position:0% +uniform we would be done. So it's really + + + align:start position:0% +uniform we would be done. So it's really +very similar to what we have been + + align:start position:0% +very similar to what we have been + + + align:start position:0% +very similar to what we have been +discussing in the rest of the lecture. + + align:start position:0% +discussing in the rest of the lecture. + + + align:start position:0% +discussing in the rest of the lecture. +So this can be proved + + align:start position:0% +So this can be proved + + + align:start position:0% +So this can be proved +[Applause] + + align:start position:0% + + + + align:start position:0% + +using + + align:start position:0% +using + + + align:start position:0% +using +a similar strategy + + align:start position:0% + + + + align:start position:0% + +as for + + align:start position:0% +as for + + + align:start position:0% +as for +a plus little aa or it can also be done + + align:start position:0% +a plus little aa or it can also be done + + + align:start position:0% +a plus little aa or it can also be done +without using uniformization + + align:start position:0% + + + + align:start position:0% + +by double counting. So okay + + align:start position:0% +by double counting. So okay + + + align:start position:0% +by double counting. So okay +uh I guess one needs uniform some okay + + align:start position:0% +uh I guess one needs uniform some okay + + + align:start position:0% +uh I guess one needs uniform some okay +maybe not uniformization but if one + + align:start position:0% +maybe not uniformization but if one + + + align:start position:0% +maybe not uniformization but if one +doesn't use uniformization maybe one is + + align:start position:0% +doesn't use uniformization maybe one is + + + align:start position:0% +doesn't use uniformization maybe one is +some sort of frostman's lema but okay so + + align:start position:0% +some sort of frostman's lema but okay so + + + align:start position:0% +some sort of frostman's lema but okay so +it can be done but I just wanted to + + align:start position:0% +it can be done but I just wanted to + + + align:start position:0% +it can be done but I just wanted to +point out that this is yet another place + + align:start position:0% +point out that this is yet another place + + + align:start position:0% +point out that this is yet another place +where we need to worry about the fact + + align:start position:0% +where we need to worry about the fact + + + align:start position:0% +where we need to worry about the fact +that so the difference between the + + align:start position:0% +that so the difference between the + + + align:start position:0% +that so the difference between the +uklidian setting and the final field + + align:start position:0% +uklidian setting and the final field + + + align:start position:0% +uklidian setting and the final field +setting okay + + align:start position:0% +setting okay + + + align:start position:0% +setting okay +and now once we know this we are really + + align:start position:0% +and now once we know this we are really + + + align:start position:0% +and now once we know this we are really +done because using balance + + align:start position:0% +done because using balance + + + align:start position:0% +done because using balance +three times we can assume that x is a + + align:start position:0% +three times we can assume that x is a + + + align:start position:0% +three times we can assume that x is a +cartitionian product and we just need to + + align:start position:0% +cartitionian product and we just need to + + + align:start position:0% +cartitionian product and we just need to +know that the projection uh in a given + + align:start position:0% +know that the projection uh in a given + + + align:start position:0% +know that the projection uh in a given +direction grows and it is given by + + align:start position:0% +direction grows and it is given by + + + align:start position:0% +direction grows and it is given by +Listen, + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +hey, + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +And then uh we apply double star. + + align:start position:0% + + + + align:start position:0% + +Okay. So since there are five minutes + + align:start position:0% +Okay. So since there are five minutes + + + align:start position:0% +Okay. So since there are five minutes +left, let me summarize what what's been + + align:start position:0% +left, let me summarize what what's been + + + align:start position:0% +left, let me summarize what what's been +going on. So what is the idea of like + + align:start position:0% +going on. So what is the idea of like + + + align:start position:0% +going on. So what is the idea of like +general idea of the proof both in the + + align:start position:0% +general idea of the proof both in the + + + align:start position:0% +general idea of the proof both in the +finite field setting and the nuclear + + align:start position:0% +finite field setting and the nuclear + + + align:start position:0% +finite field setting and the nuclear +setting? First we work with the set in + + align:start position:0% +setting? First we work with the set in + + + align:start position:0% +setting? First we work with the set in +one dimension and shows that if the set + + align:start position:0% +one dimension and shows that if the set + + + align:start position:0% +one dimension and shows that if the set +is not already everything then is + + align:start position:0% +is not already everything then is + + + align:start position:0% +is not already everything then is +expanded by some polomial. Then we + + align:start position:0% +expanded by some polomial. Then we + + + align:start position:0% +expanded by some polomial. Then we +simplify the polomial using plunicus. + + align:start position:0% +simplify the polomial using plunicus. + + + align:start position:0% +simplify the polomial using plunicus. +Then we iterate. In order to iterate one + + align:start position:0% +Then we iterate. In order to iterate one + + + align:start position:0% +Then we iterate. In order to iterate one +has to be much much much more careful in + + align:start position:0% +has to be much much much more careful in + + + align:start position:0% +has to be much much much more careful in +the uklidian setting in order to show + + align:start position:0% +the uklidian setting in order to show + + + align:start position:0% +the uklidian setting in order to show +that the hypothesis of the expansion are + + align:start position:0% +that the hypothesis of the expansion are + + + align:start position:0% +that the hypothesis of the expansion are +satisfied when we apply the growth once. + + align:start position:0% +satisfied when we apply the growth once. + + + align:start position:0% +satisfied when we apply the growth once. +So we can iterate but eventually we can + + align:start position:0% +So we can iterate but eventually we can + + + align:start position:0% +So we can iterate but eventually we can +iterate that means that we can expand + + align:start position:0% +iterate that means that we can expand + + + align:start position:0% +iterate that means that we can expand +the given set a to almost everything by + + align:start position:0% +the given set a to almost everything by + + + align:start position:0% +the given set a to almost everything by +some polomial. Once we can expand by a + + align:start position:0% +some polomial. Once we can expand by a + + + align:start position:0% +some polomial. Once we can expand by a +polinomial to almost everything we get + + align:start position:0% +polinomial to almost everything we get + + + align:start position:0% +polinomial to almost everything we get +this growth. + + align:start position:0% +this growth. + + + align:start position:0% +this growth. +It is still of some product type but the + + align:start position:0% +It is still of some product type but the + + + align:start position:0% +It is still of some product type but the +difference is that X now can be much + + align:start position:0% +difference is that X now can be much + + + align:start position:0% +difference is that X now can be much +bigger than A. And the fact that X is + + align:start position:0% +bigger than A. And the fact that X is + + + align:start position:0% +bigger than A. And the fact that X is +much bigger than A is not an issue + + align:start position:0% +much bigger than A is not an issue + + + align:start position:0% +much bigger than A is not an issue +because instead of working with A, we + + align:start position:0% +because instead of working with A, we + + + align:start position:0% +because instead of working with A, we +work with a polomial applied to A which + + align:start position:0% +work with a polomial applied to A which + + + align:start position:0% +work with a polomial applied to A which +has size bigger than the size of X. And + + align:start position:0% +has size bigger than the size of X. And + + + align:start position:0% +has size bigger than the size of X. And +finally uh we want to project something + + align:start position:0% +finally uh we want to project something + + + align:start position:0% +finally uh we want to project something +which is not a product but by looking at + + align:start position:0% +which is not a product but by looking at + + + align:start position:0% +which is not a product but by looking at +three projections to begin with which + + align:start position:0% +three projections to begin with which + + + align:start position:0% +three projections to begin with which +are far away from each other and + + align:start position:0% +are far away from each other and + + + align:start position:0% +are far away from each other and +applying bioicical hours many times we + + align:start position:0% +applying bioicical hours many times we + + + align:start position:0% +applying bioicical hours many times we +can go back to this setting. + + align:start position:0% +can go back to this setting. + + + align:start position:0% +can go back to this setting. +So that's the short version of the proof + + align:start position:0% +So that's the short version of the proof + + + align:start position:0% +So that's the short version of the proof +and they are again in the ukian setting + + align:start position:0% +and they are again in the ukian setting + + + align:start position:0% +and they are again in the ukian setting +one has to be careful to show that the + + align:start position:0% +one has to be careful to show that the + + + align:start position:0% +one has to be careful to show that the +projections + + align:start position:0% +projections + + + align:start position:0% +projections +uh satisfy the assumptions needed to + + align:start position:0% +uh satisfy the assumptions needed to + + + align:start position:0% +uh satisfy the assumptions needed to +apply this fact. So you have to be so + + align:start position:0% +apply this fact. So you have to be so + + + align:start position:0% +apply this fact. So you have to be so +really you need some at least some non + + align:start position:0% +really you need some at least some non + + + align:start position:0% +really you need some at least some non +concentration on x because again if x + + align:start position:0% +concentration on x because again if x + + + align:start position:0% +concentration on x because again if x +was a small interval + + align:start position:0% +was a small interval + + + align:start position:0% +was a small interval +then this never grows for any a so one + + align:start position:0% +then this never grows for any a so one + + + align:start position:0% +then this never grows for any a so one +needs some assumption on x. So one needs + + align:start position:0% +needs some assumption on x. So one needs + + + align:start position:0% +needs some assumption on x. So one needs +to prove something like that. But okay, + + align:start position:0% +to prove something like that. But okay, + + + align:start position:0% +to prove something like that. But okay, +one can prove it and then eventually one + + align:start position:0% +one can prove it and then eventually one + + + align:start position:0% +one can prove it and then eventually one +uses this. + + align:start position:0% +uses this. + + + align:start position:0% +uses this. +Any final questions? + + align:start position:0% + + + + align:start position:0% + +>> How many times have we used PSG? + + align:start position:0% + + + + align:start position:0% + +>> Uh + + align:start position:0% +>> Uh + + + align:start position:0% +>> Uh +so either four or six. I'm not + + align:start position:0% +so either four or six. I'm not + + + align:start position:0% +so either four or six. I'm not +completely sure. Uh I think no. I think + + align:start position:0% +completely sure. Uh I think no. I think + + + align:start position:0% +completely sure. Uh I think no. I think +the first time we already have a + + align:start position:0% +the first time we already have a + + + align:start position:0% +the first time we already have a +product. Yeah, I think once for a plus + + align:start position:0% +product. Yeah, I think once for a plus + + + align:start position:0% +product. Yeah, I think once for a plus +little aa and then three times + + align:start position:0% +little aa and then three times + + + align:start position:0% +little aa and then three times +uh to reduce to this setting. + + align:start position:0% +uh to reduce to this setting. + + + align:start position:0% +uh to reduce to this setting. +>> Okay. Like + + align:start position:0% +>> Okay. Like + + + align:start position:0% +>> Okay. Like +is it for like well we just want the + + align:start position:0% +is it for like well we just want the + + + align:start position:0% +is it for like well we just want the +projection of like x itself is big in + + align:start position:0% +projection of like x itself is big in + + + align:start position:0% +projection of like x itself is big in +one direction or it's like for the proof + + align:start position:0% +one direction or it's like for the proof + + + align:start position:0% +one direction or it's like for the proof +that's for any subs. + + align:start position:0% +that's for any subs. + + + align:start position:0% +that's for any subs. +>> Yeah. Okay. So indefinitely setting is + + align:start position:0% +>> Yeah. Okay. So indefinitely setting is + + + align:start position:0% +>> Yeah. Okay. So indefinitely setting is +as you are suggesting is much easier to + + align:start position:0% +as you are suggesting is much easier to + + + align:start position:0% +as you are suggesting is much easier to +prove that the projection of X itself is + + align:start position:0% +prove that the projection of X itself is + + + align:start position:0% +prove that the projection of X itself is +big than proving it for dense subsets. + + align:start position:0% +big than proving it for dense subsets. + + + align:start position:0% +big than proving it for dense subsets. +But in the ukidian case even if your + + align:start position:0% +But in the ukidian case even if your + + + align:start position:0% +But in the ukidian case even if your +goal is to pro is proving that the + + align:start position:0% +goal is to pro is proving that the + + + align:start position:0% +goal is to pro is proving that the +projection of X is large and you don't + + align:start position:0% +projection of X is large and you don't + + + align:start position:0% +projection of X is large and you don't +care about dense subsets you are still + + align:start position:0% +care about dense subsets you are still + + + align:start position:0% +care about dense subsets you are still +forced to care about dense subsets + + align:start position:0% +forced to care about dense subsets + + + align:start position:0% +forced to care about dense subsets +because you need the dense subsets to + + align:start position:0% +because you need the dense subsets to + + + align:start position:0% +because you need the dense subsets to +prove the non-conentration assumption + + align:start position:0% +prove the non-conentration assumption + + + align:start position:0% +prove the non-conentration assumption +when you iterate. So how did we prove + + align:start position:0% +when you iterate. So how did we prove + + + align:start position:0% +when you iterate. So how did we prove +that a plus little aa satisfies the + + align:start position:0% +that a plus little aa satisfies the + + + align:start position:0% +that a plus little aa satisfies the +stronger non-conentration assumption? + + align:start position:0% +stronger non-conentration assumption? + + + align:start position:0% +stronger non-conentration assumption? +By proving that the projection of dense + + align:start position:0% +By proving that the projection of dense + + + align:start position:0% +By proving that the projection of dense +subsets of a * a are large. So even if + + align:start position:0% +subsets of a * a are large. So even if + + + align:start position:0% +subsets of a * a are large. So even if +your your ultimate goal doesn't involve + + align:start position:0% +your your ultimate goal doesn't involve + + + align:start position:0% +your your ultimate goal doesn't involve +looking at dense subsets, you still need + + align:start position:0% +looking at dense subsets, you still need + + + align:start position:0% +looking at dense subsets, you still need +to look at them subsets along the proof + + align:start position:0% +to look at them subsets along the proof + + + align:start position:0% +to look at them subsets along the proof +and you cannot avoid that. Or maybe you + + align:start position:0% +and you cannot avoid that. Or maybe you + + + align:start position:0% +and you cannot avoid that. Or maybe you +can, but at least with this method of + + align:start position:0% +can, but at least with this method of + + + align:start position:0% +can, but at least with this method of +proof, you cannot avoid that. + + align:start position:0% + + + + align:start position:0% + +Yes. + + align:start position:0% +Yes. + + + align:start position:0% +Yes. +>> Can you say a little bit more about how + + align:start position:0% +>> Can you say a little bit more about how + + + align:start position:0% +>> Can you say a little bit more about how +to handle the issue that the uniform + + align:start position:0% +to handle the issue that the uniform + + + align:start position:0% +to handle the issue that the uniform +subset at different scales might be + + align:start position:0% +subset at different scales might be + + + align:start position:0% +subset at different scales might be +different? + + align:start position:0% +different? + + + align:start position:0% +different? +>> Yeah. So I unfortunately I didn't + + align:start position:0% +>> Yeah. So I unfortunately I didn't + + + align:start position:0% +>> Yeah. So I unfortunately I didn't +realize this issue would arise so I + + align:start position:0% +realize this issue would arise so I + + + align:start position:0% +realize this issue would arise so I +didn't check carefully. + + align:start position:0% +didn't check carefully. + + + align:start position:0% +didn't check carefully. +>> Um but yeah it's a it's a it's a very + + align:start position:0% +>> Um but yeah it's a it's a it's a very + + + align:start position:0% +>> Um but yeah it's a it's a it's a very +good question. Um + + align:start position:0% + + + + align:start position:0% + +yeah. Okay. So I'm not exactly sure but + + align:start position:0% +yeah. Okay. So I'm not exactly sure but + + + align:start position:0% +yeah. Okay. So I'm not exactly sure but +let me say something that might work in + + align:start position:0% +let me say something that might work in + + + align:start position:0% +let me say something that might work in +this case but it certainly works in + + align:start position:0% +this case but it certainly works in + + + align:start position:0% +this case but it certainly works in +other cases. So I explained an idea + + align:start position:0% +other cases. So I explained an idea + + + align:start position:0% +other cases. So I explained an idea +superficially of first getting an a + + align:start position:0% +superficially of first getting an a + + + align:start position:0% +superficially of first getting an a +prime and if that a prime doesn't + + align:start position:0% +prime and if that a prime doesn't + + + align:start position:0% +prime and if that a prime doesn't +exhaust a we take it away and find + + align:start position:0% +exhaust a we take it away and find + + + align:start position:0% +exhaust a we take it away and find +another a prime. One can do something + + align:start position:0% +another a prime. One can do something + + + align:start position:0% +another a prime. One can do something +similar for uniform sets. So rather than + + align:start position:0% +similar for uniform sets. So rather than + + + align:start position:0% +similar for uniform sets. So rather than +taking one uniform subset, one can so + + align:start position:0% +taking one uniform subset, one can so + + + align:start position:0% +taking one uniform subset, one can so +one is given a set and one knows nothing + + align:start position:0% +one is given a set and one knows nothing + + + align:start position:0% +one is given a set and one knows nothing +about that set and we can nearly exhaust + + align:start position:0% +about that set and we can nearly exhaust + + + align:start position:0% +about that set and we can nearly exhaust +that set by a finite union of uniform + + align:start position:0% +that set by a finite union of uniform + + + align:start position:0% +that set by a finite union of uniform +subsets. So one finds a dense uniform + + align:start position:0% +subsets. So one finds a dense uniform + + + align:start position:0% +subsets. So one finds a dense uniform +set takes it away finds another uniform + + align:start position:0% +set takes it away finds another uniform + + + align:start position:0% +set takes it away finds another uniform +set takes it away and in this way we + + align:start position:0% +set takes it away and in this way we + + + align:start position:0% +set takes it away and in this way we +essentially cover the set with a very + + align:start position:0% +essentially cover the set with a very + + + align:start position:0% +essentially cover the set with a very +small error by uniform subsets. Uh so + + align:start position:0% +small error by uniform subsets. Uh so + + + align:start position:0% +small error by uniform subsets. Uh so +this is one way to get around the issue + + align:start position:0% +this is one way to get around the issue + + + align:start position:0% +this is one way to get around the issue +that one uniform substate itself is + + align:start position:0% +that one uniform substate itself is + + + align:start position:0% +that one uniform substate itself is +maybe too sparse and then at different + + align:start position:0% +maybe too sparse and then at different + + + align:start position:0% +maybe too sparse and then at different +scales different things could happen. + + align:start position:0% + + + + align:start position:0% + +So that's I think that could be one way. + + align:start position:0% +So that's I think that could be one way. + + + align:start position:0% +So that's I think that could be one way. +I don't think that's what we do in the + + align:start position:0% +I don't think that's what we do in the + + + align:start position:0% +I don't think that's what we do in the +paper but I think that's one thing you + + align:start position:0% +paper but I think that's one thing you + + + align:start position:0% +paper but I think that's one thing you +could do to bypass this issue. + + align:start position:0% +could do to bypass this issue. + + + align:start position:0% +could do to bypass this issue. +>> Yeah. You said last time that there was + + align:start position:0% +>> Yeah. You said last time that there was + + + align:start position:0% +>> Yeah. You said last time that there was +possibly a way to simplify this. + + align:start position:0% +possibly a way to simplify this. + + + align:start position:0% +possibly a way to simplify this. +>> Uh we we are not sure yet. Uh we are + + align:start position:0% +>> Uh we we are not sure yet. Uh we are + + + align:start position:0% +>> Uh we we are not sure yet. Uh we are +hopeful. Yes. + + align:start position:0% +hopeful. Yes. + + + align:start position:0% +hopeful. Yes. +Yeah. again um this so bugan's original + + align:start position:0% +Yeah. again um this so bugan's original + + + align:start position:0% +Yeah. again um this so bugan's original +proof uh is different in the sense that + + align:start position:0% +proof uh is different in the sense that + + + align:start position:0% +proof uh is different in the sense that +he didn't construct an expanding + + align:start position:0% +he didn't construct an expanding + + + align:start position:0% +he didn't construct an expanding +polomial at all + + align:start position:0% +polomial at all + + + align:start position:0% +polomial at all +but it is similar in the sense that + + align:start position:0% +but it is similar in the sense that + + + align:start position:0% +but it is similar in the sense that +uh he proves this and then uses the many + + align:start position:0% +uh he proves this and then uses the many + + + align:start position:0% +uh he proves this and then uses the many +back symmetric hours to + + align:start position:0% +back symmetric hours to + + + align:start position:0% +back symmetric hours to +to to get the full statement but to + + align:start position:0% +to to get the full statement but to + + + align:start position:0% +to to get the full statement but to +prove this he did something different + + align:start position:0% +prove this he did something different + + + align:start position:0% +prove this he did something different +but okay other claim is more difficult + + align:start position:0% +but okay other claim is more difficult + + + align:start position:0% +but okay other claim is more difficult +than what I explained but I don't know + + align:start position:0% +than what I explained but I don't know + + + align:start position:0% +than what I explained but I don't know +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +yeah now now we have this idea from last + + align:start position:0% +yeah now now we have this idea from last + + + align:start position:0% +yeah now now we have this idea from last +week uh that yeah might be a so + + align:start position:0% +week uh that yeah might be a so + + + align:start position:0% +week uh that yeah might be a so +basically it would be a much easier way + + align:start position:0% +basically it would be a much easier way + + + align:start position:0% +basically it would be a much easier way +of doing this to go from this to the + + align:start position:0% +of doing this to go from this to the + + + align:start position:0% +of doing this to go from this to the +full statement the only way we know how + + align:start position:0% +full statement the only way we know how + + + align:start position:0% +full statement the only way we know how +to do it is how Bang did it by doing the + + align:start position:0% +to do it is how Bang did it by doing the + + + align:start position:0% +to do it is how Bang did it by doing the +many barometric \ No newline at end of file diff --git a/89GQHKOeUcU.txt b/89GQHKOeUcU.txt new file mode 100644 index 0000000000000000000000000000000000000000..3f6d709b6f18d666132020fb0569d39e8d9156f2 --- /dev/null +++ b/89GQHKOeUcU.txt @@ -0,0 +1,11533 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay welcome back + + align:start position:0% +ocw.mit.edu okay welcome back + + + align:start position:0% +ocw.mit.edu okay welcome back +um since we ended abruptly I want to + + align:start position:0% +um since we ended abruptly I want to + + + align:start position:0% +um since we ended abruptly I want to +start with a recap of last time and and + + align:start position:0% +start with a recap of last time and and + + + align:start position:0% +start with a recap of last time and and +uh and then we've got a lot of new uh + + align:start position:0% +uh and then we've got a lot of new uh + + + align:start position:0% +uh and then we've got a lot of new uh +ground to cover + + align:start position:0% +ground to cover + + + align:start position:0% +ground to cover +so remember last time + + align:start position:0% + + + + align:start position:0% + +um we uh we consider the system Q do + + align:start position:0% +um we uh we consider the system Q do + + + align:start position:0% +um we uh we consider the system Q do +equals + + align:start position:0% +equals + + + align:start position:0% +equals +U which is of a general form just a a + + align:start position:0% +U which is of a general form just a a + + + align:start position:0% +U which is of a general form just a a +linear feedback system in state space + + align:start position:0% +linear feedback system in state space + + + align:start position:0% +linear feedback system in state space +form looks like + + align:start position:0% +form looks like + + + align:start position:0% +form looks like +this where it happens that A and B are + + align:start position:0% +this where it happens that A and B are + + + align:start position:0% +this where it happens that A and B are +particularly + + align:start position:0% +particularly + + + align:start position:0% +particularly +simple um and we looked at + + align:start position:0% +simple um and we looked at + + + align:start position:0% +simple um and we looked at +designing let's not say designning + + align:start position:0% +designing let's not say designning + + + align:start position:0% +designing let's not say designning +control we looked at reshaping the phase + + align:start position:0% +control we looked at reshaping the phase + + + align:start position:0% +control we looked at reshaping the phase +space um a couple different ways the + + align:start position:0% +space um a couple different ways the + + + align:start position:0% +space um a couple different ways the +first way which is the uh sort of + + align:start position:0% +first way which is the uh sort of + + + align:start position:0% +first way which is the uh sort of +6.32a maybe would be uh uh designing + + align:start position:0% +6.32a maybe would be uh uh designing + + + align:start position:0% +6.32a maybe would be uh uh designing +sort of by pole placement by by + + align:start position:0% +sort of by pole placement by by + + + align:start position:0% +sort of by pole placement by by +designing feedback gains uh possibly by + + align:start position:0% +designing feedback gains uh possibly by + + + align:start position:0% +designing feedback gains uh possibly by +by hand possibly by a root Locus + + align:start position:0% +by hand possibly by a root Locus + + + align:start position:0% +by hand possibly by a root Locus +analysis so we looked at + + align:start position:0% + + + + align:start position:0% + +manually + + align:start position:0% + + + + align:start position:0% + +designing some linear feedback law U + + align:start position:0% +designing some linear feedback law U + + + align:start position:0% +designing some linear feedback law U +equal KX right and we did things like + + align:start position:0% +equal KX right and we did things like + + + align:start position:0% +equal KX right and we did things like +plotting the the face + + align:start position:0% + + + + align:start position:0% + +portrait which gave + + align:start position:0% +portrait which gave + + + align:start position:0% +portrait which gave +us for + + align:start position:0% +us for + + + align:start position:0% +us for +Q Q + + align:start position:0% + + + + align:start position:0% + +dot + + align:start position:0% +dot + + + align:start position:0% +dot +um a phase portrait that looked like + + align:start position:0% + + + + align:start position:0% + +this where this has an igen value of + + align:start position:0% +this where this has an igen value of + + + align:start position:0% +this where this has an igen value of +um + + align:start position:0% + + + + align:start position:0% + +-3.75 approximately and this one had an + + align:start position:0% +-3.75 approximately and this one had an + + + align:start position:0% +-3.75 approximately and this one had an +IG value of negative + + align:start position:0% + + + + align:start position:0% + +.25 this was all for K = 1 + + align:start position:0% + + + + align:start position:0% + +4 okay and we ended up seeing that just + + align:start position:0% +4 okay and we ended up seeing that just + + + align:start position:0% +4 okay and we ended up seeing that just +from that quick analysis um we could see + + align:start position:0% +from that quick analysis um we could see + + + align:start position:0% +from that quick analysis um we could see +phase portraits which looked like this + + align:start position:0% +phase portraits which looked like this + + + align:start position:0% +phase portraits which looked like this +they'd come across the origin and then + + align:start position:0% +they'd come across the origin and then + + + align:start position:0% +they'd come across the origin and then +they'd hook in towards the + + align:start position:0% +they'd hook in towards the + + + align:start position:0% +they'd hook in towards the +the goal + + align:start position:0% + + + + align:start position:0% + +right and similarly here this one's so + + align:start position:0% +right and similarly here this one's so + + + align:start position:0% +right and similarly here this one's so +much faster that it would go like this + + align:start position:0% + + + + align:start position:0% + +okay then we looked at um an optimal + + align:start position:0% +okay then we looked at um an optimal + + + align:start position:0% +okay then we looked at um an optimal +control way of solving the same thing + + align:start position:0% +control way of solving the same thing + + + align:start position:0% +control way of solving the same thing +right um we looked at doing a minimum + + align:start position:0% + + + + align:start position:0% + +time optimal control approach + + align:start position:0% + + + + align:start position:0% + +not specifically so that we could get + + align:start position:0% +not specifically so that we could get + + + align:start position:0% +not specifically so that we could get +there faster even though the minimum + + align:start position:0% +there faster even though the minimum + + + align:start position:0% +there faster even though the minimum +time is in the the name because here + + align:start position:0% +time is in the the name because here + + + align:start position:0% +time is in the the name because here +remember we could get there arbitrarily + + align:start position:0% +remember we could get there arbitrarily + + + align:start position:0% +remember we could get there arbitrarily +fast by just cranking K as high as we + + align:start position:0% +fast by just cranking K as high as we + + + align:start position:0% +fast by just cranking K as high as we +wanted but actually for trying to do + + align:start position:0% +wanted but actually for trying to do + + + align:start position:0% +wanted but actually for trying to do +something a little bit smarter which is + + align:start position:0% +something a little bit smarter which is + + + align:start position:0% +something a little bit smarter which is +get there in minimum time when I have an + + align:start position:0% +get there in minimum time when I have an + + + align:start position:0% +get there in minimum time when I have an +extra constraint the U was bounded in + + align:start position:0% +extra constraint the U was bounded in + + + align:start position:0% +extra constraint the U was bounded in +the case we looked that yesterday was + + align:start position:0% +the case we looked that yesterday was + + + align:start position:0% +the case we looked that yesterday was +bounded by -1 one okay and in that case + + align:start position:0% +bounded by -1 one okay and in that case + + + align:start position:0% +bounded by -1 one okay and in that case +When U was bounded now the minimum time + + align:start position:0% +When U was bounded now the minimum time + + + align:start position:0% +When U was bounded now the minimum time +problem becomes non-trivial it's not + + align:start position:0% +problem becomes non-trivial it's not + + + align:start position:0% +problem becomes non-trivial it's not +just crank the gains to Infinity um and + + align:start position:0% +just crank the gains to Infinity um and + + + align:start position:0% +just crank the gains to Infinity um and +we had to use some some better thinking + + align:start position:0% +we had to use some some better thinking + + + align:start position:0% +we had to use some some better thinking +about + + align:start position:0% +about + + + align:start position:0% +about +it and the result + + align:start position:0% + + + + align:start position:0% + +was a phase + + align:start position:0% +was a phase + + + align:start position:0% +was a phase +portrait which actually I I don't know + + align:start position:0% +portrait which actually I I don't know + + + align:start position:0% +portrait which actually I I don't know +if you left realizing it didn't look + + align:start position:0% +if you left realizing it didn't look + + + align:start position:0% +if you left realizing it didn't look +that different right in some ways um + + align:start position:0% +that different right in some ways um + + + align:start position:0% +that different right in some ways um +remember we + + align:start position:0% +remember we + + + align:start position:0% +remember we +had these switching surfaces defined + + align:start position:0% +had these switching surfaces defined + + + align:start position:0% +had these switching surfaces defined +here okay and above + + align:start position:0% +here okay and above + + + align:start position:0% +here okay and above +this we'd execute one policy one bang + + align:start position:0% +this we'd execute one policy one bang + + + align:start position:0% +this we'd execute one policy one bang +bang solution and below it we'd execute + + align:start position:0% +bang solution and below it we'd execute + + + align:start position:0% +bang solution and below it we'd execute +another one + + align:start position:0% +another one + + + align:start position:0% +another one +okay and the resulting system + + align:start position:0% +okay and the resulting system + + + align:start position:0% +okay and the resulting system +trajectories remember this one hooked + + align:start position:0% +trajectories remember this one hooked + + + align:start position:0% +trajectories remember this one hooked +down across the origin and went into the + + align:start position:0% +down across the origin and went into the + + + align:start position:0% +down across the origin and went into the +goal like that this one really did + + align:start position:0% +goal like that this one really did + + + align:start position:0% +goal like that this one really did +exactly the same thing right it they + + align:start position:0% +exactly the same thing right it they + + + align:start position:0% +exactly the same thing right it they +would start over here they'd hook down + + align:start position:0% +would start over here they'd hook down + + + align:start position:0% +would start over here they'd hook down +here but this time they'd + + align:start position:0% +here but this time they'd + + + align:start position:0% +here but this time they'd +explicitly hit that switching surface + + align:start position:0% +explicitly hit that switching surface + + + align:start position:0% +explicitly hit that switching surface +and then ride that into the + + align:start position:0% +and then ride that into the + + + align:start position:0% +and then ride that into the +goal + + align:start position:0% +goal + + + align:start position:0% +goal +right so it's a little bit of a + + align:start position:0% +right so it's a little bit of a + + + align:start position:0% +right so it's a little bit of a +sharper um + + align:start position:0% +sharper um + + + align:start position:0% +sharper um +result possibly than the other one and + + align:start position:0% +result possibly than the other one and + + + align:start position:0% +result possibly than the other one and +the um that final surface was a curve + + align:start position:0% +the um that final surface was a curve + + + align:start position:0% +the um that final surface was a curve +instead of this this + + align:start position:0% +instead of this this + + + align:start position:0% +instead of this this +line and for that we got to have um good + + align:start position:0% +line and for that we got to have um good + + + align:start position:0% +line and for that we got to have um good +performance with bounded + + align:start position:0% +performance with bounded + + + align:start position:0% +performance with bounded +torqus + + align:start position:0% +torqus + + + align:start position:0% +torqus +okay now we also did um the first of two + + align:start position:0% +okay now we also did um the first of two + + + align:start position:0% +okay now we also did um the first of two +ways that we're going to use to to sort + + align:start position:0% +ways that we're going to use to to sort + + + align:start position:0% +ways that we're going to use to to sort +of analytically investigate + + align:start position:0% + + + + align:start position:0% + +optimality anytime + + align:start position:0% +optimality anytime + + + align:start position:0% +optimality anytime +yeah was there a good reason we just + + align:start position:0% +yeah was there a good reason we just + + + align:start position:0% +yeah was there a good reason we just +atically said we want to do linear + + align:start position:0% +atically said we want to do linear + + + align:start position:0% +atically said we want to do linear +feedback there we could have done like + + align:start position:0% +feedback there we could have done like + + + align:start position:0% +feedback there we could have done like +X1 * X2 good yeah um it's because well + + align:start position:0% +X1 * X2 good yeah um it's because well + + + align:start position:0% +X1 * X2 good yeah um it's because well +there's a lot of good reasons so it's + + align:start position:0% +there's a lot of good reasons so it's + + + align:start position:0% +there's a lot of good reasons so it's +because then the closed loop Dynamics + + align:start position:0% +because then the closed loop Dynamics + + + align:start position:0% +because then the closed loop Dynamics +are + + align:start position:0% +are + + + align:start position:0% +are +linear and we can analyze them in every + + align:start position:0% +linear and we can analyze them in every + + + align:start position:0% +linear and we can analyze them in every +way and including making these plots in + + align:start position:0% +way and including making these plots in + + + align:start position:0% +way and including making these plots in +ways that I couldn't have done with this + + align:start position:0% +ways that I couldn't have done with this + + + align:start position:0% +ways that I couldn't have done with this +was + + align:start position:0% +was + + + align:start position:0% +was +nonlinear the the another answer would + + align:start position:0% +nonlinear the the another answer would + + + align:start position:0% +nonlinear the the another answer would +be that this is what 90% of the world + + align:start position:0% +be that this is what 90% of the world + + + align:start position:0% +be that this is what 90% of the world +would have done if that's satisfying at + + align:start position:0% +would have done if that's satisfying at + + + align:start position:0% +would have done if that's satisfying at +all I think that's a that's you know the + + align:start position:0% +all I think that's a that's you know the + + + align:start position:0% +all I think that's a that's you know the +dominant way of sort of thinking about + + align:start position:0% +dominant way of sort of thinking about + + + align:start position:0% +dominant way of sort of thinking about +these things X1 * X2 is comparably much + + align:start position:0% +these things X1 * X2 is comparably much + + + align:start position:0% +these things X1 * X2 is comparably much +harder to reason about actually I I + + align:start position:0% +harder to reason about actually I I + + + align:start position:0% +harder to reason about actually I I +totally agree but is there like a system + + align:start position:0% +totally agree but is there like a system + + + align:start position:0% +totally agree but is there like a system +that the optim controller lies in in in + + align:start position:0% +that the optim controller lies in in in + + + align:start position:0% +that the optim controller lies in in in +a space that you have to take into + + align:start position:0% +a space that you have to take into + + + align:start position:0% +a space that you have to take into +account these + + align:start position:0% +account these + + + align:start position:0% +account these +different good so this is an example of + + align:start position:0% +different good so this is an example of + + + align:start position:0% +different good so this is an example of +of a nonlinear + + align:start position:0% +of a nonlinear + + + align:start position:0% +of a nonlinear +controller right it happens that the + + align:start position:0% +controller right it happens that the + + + align:start position:0% +controller right it happens that the +actual control action is either one or + + align:start position:0% +actual control action is either one or + + + align:start position:0% +actual control action is either one or +negative one right but the decision + + align:start position:0% +negative one right but the decision + + + align:start position:0% +negative one right but the decision +plane is very + + align:start position:0% +plane is very + + + align:start position:0% +plane is very +nonlinear right so that's absolutely a + + align:start position:0% +nonlinear right so that's absolutely a + + + align:start position:0% +nonlinear right so that's absolutely a +nonlinear + + align:start position:0% +nonlinear + + + align:start position:0% +nonlinear +controller okay it come out came out of + + align:start position:0% +controller okay it come out came out of + + + align:start position:0% +controller okay it come out came out of +linear out of optimal control on a + + align:start position:0% +linear out of optimal control on a + + + align:start position:0% +linear out of optimal control on a +linear system but the result is a + + align:start position:0% +linear system but the result is a + + + align:start position:0% +linear system but the result is a +nonlinear + + align:start position:0% +nonlinear + + + align:start position:0% +nonlinear +controller + + align:start position:0% +controller + + + align:start position:0% +controller +okay now certain classes of nonlinear + + align:start position:0% +okay now certain classes of nonlinear + + + align:start position:0% +okay now certain classes of nonlinear +controllers are going to pop out and + + align:start position:0% +controllers are going to pop out and + + + align:start position:0% +controllers are going to pop out and +could be easier to think about than than + + align:start position:0% +could be easier to think about than than + + + align:start position:0% +could be easier to think about than than +the broad class but but there you're + + align:start position:0% +the broad class but but there you're + + + align:start position:0% +the broad class but but there you're +going to see lots of instances as + + align:start position:0% +going to see lots of instances as + + + align:start position:0% +going to see lots of instances as +quickly as we + + align:start position:0% + + + + align:start position:0% + +can okay so we did um we actually got + + align:start position:0% +can okay so we did um we actually got + + + align:start position:0% +can okay so we did um we actually got +that curve by thinking just about um + + align:start position:0% +that curve by thinking just about um + + + align:start position:0% +that curve by thinking just about um +just using our intuition to reason about + + align:start position:0% +just using our intuition to reason about + + + align:start position:0% +just using our intuition to reason about +bang bang control okay at the end I + + align:start position:0% +bang bang control okay at the end I + + + align:start position:0% +bang bang control okay at the end I +started to show you that the same thing + + align:start position:0% +started to show you that the same thing + + + align:start position:0% +started to show you that the same thing +comes out of um what I'll call solution + + align:start position:0% +comes out of um what I'll call solution + + + align:start position:0% +comes out of um what I'll call solution +technique + + align:start position:0% +technique + + + align:start position:0% +technique +one + + align:start position:0% + + + + align:start position:0% + +here I wouldn't call it that outside of + + align:start position:0% +here I wouldn't call it that outside of + + + align:start position:0% +here I wouldn't call it that outside of +the room that's sorry that's just me + + align:start position:0% +the room that's sorry that's just me + + + align:start position:0% +the room that's sorry that's just me +being clear here right which was based + + align:start position:0% +being clear here right which was based + + + align:start position:0% +being clear here right which was based +on pontryagin's minimum + + align:start position:0% + + + + align:start position:0% + +principle + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +which in this case is nothing more than + + align:start position:0% +which in this case is nothing more than + + + align:start position:0% +which in this case is nothing more than +just let's write it down exactly what we + + align:start position:0% +just let's write it down exactly what we + + + align:start position:0% +just let's write it down exactly what we +mean by this cost function right we + + align:start position:0% +mean by this cost function right we + + + align:start position:0% +mean by this cost function right we +have we have some let me a little bit + + align:start position:0% +have we have some let me a little bit + + + align:start position:0% +have we have some let me a little bit +more loose we have J some cost function + + align:start position:0% +more loose we have J some cost function + + + align:start position:0% +more loose we have J some cost function +we want to optimize which is a finite + + align:start position:0% +we want to optimize which is a finite + + + align:start position:0% +we want to optimize which is a finite +time um + + align:start position:0% +time um + + + align:start position:0% +time um +integral of 1 DT that sounds ridiculous + + align:start position:0% +integral of 1 DT that sounds ridiculous + + + align:start position:0% +integral of 1 DT that sounds ridiculous +but we're just optimizing time + + align:start position:0% +but we're just optimizing time + + + align:start position:0% +but we're just optimizing time +right but we want to optimize that + + align:start position:0% +right but we want to optimize that + + + align:start position:0% +right but we want to optimize that +subject to the + + align:start position:0% +subject to the + + + align:start position:0% +subject to the +constraints that x dotal f ofx + + align:start position:0% +constraints that x dotal f ofx + + + align:start position:0% +constraints that x dotal f ofx +u which in this case + + align:start position:0% +u which in this case + + + align:start position:0% +u which in this case +is our our linear + + align:start position:0% + + + + align:start position:0% + +system and the + + align:start position:0% +system and the + + + align:start position:0% +system and the +constraint that U was1 + + align:start position:0% +constraint that U was1 + + + align:start position:0% +constraint that U was1 +in that + + align:start position:0% + + + + align:start position:0% + +regime and the + + align:start position:0% +regime and the + + + align:start position:0% +regime and the +constraint that at time T XT had better + + align:start position:0% +constraint that at time T XT had better + + + align:start position:0% +constraint that at time T XT had better +be at the + + align:start position:0% + + + + align:start position:0% + +origin given those constraints we can + + align:start position:0% +origin given those constraints we can + + + align:start position:0% +origin given those constraints we can +say let's let's minimize + + align:start position:0% +say let's let's minimize + + + align:start position:0% +say let's let's minimize +um + + align:start position:0% +um + + + align:start position:0% +um +T we're going to minimize that J sorry I + + align:start position:0% +T we're going to minimize that J sorry I + + + align:start position:0% +T we're going to minimize that J sorry I +already got the T in there minimize it + + align:start position:0% +already got the T in there minimize it + + + align:start position:0% +already got the T in there minimize it +with respect to um to the + + align:start position:0% +with respect to um to the + + + align:start position:0% +with respect to um to the +trajectory in + + align:start position:0% +trajectory in + + + align:start position:0% +trajectory in +XU um that cost function I use this over + + align:start position:0% +XU um that cost function I use this over + + + align:start position:0% +XU um that cost function I use this over +bar to denote the entire time history of + + align:start position:0% +bar to denote the entire time history of + + + align:start position:0% +bar to denote the entire time history of +of a variable like + + align:start position:0% +of a variable like + + + align:start position:0% +of a variable like +X T1 + + align:start position:0% +X T1 + + + align:start position:0% +X T1 +to T final or something like this t0 to + + align:start position:0% + + + + align:start position:0% + +tfal okay that's how we set up the + + align:start position:0% +tfal okay that's how we set up the + + + align:start position:0% +tfal okay that's how we set up the +problem it's just optimizing some + + align:start position:0% +problem it's just optimizing some + + + align:start position:0% +problem it's just optimizing some +function but subject to a a handful of + + align:start position:0% +function but subject to a a handful of + + + align:start position:0% +function but subject to a a handful of +constraints okay pontryagin's minimum + + align:start position:0% +constraints okay pontryagin's minimum + + + align:start position:0% +constraints okay pontryagin's minimum +principle is nothing more than than + + align:start position:0% +principle is nothing more than than + + + align:start position:0% +principle is nothing more than than +putting lrange multipliers to work to + + align:start position:0% +putting lrange multipliers to work to + + + align:start position:0% +putting lrange multipliers to work to +turn that constrained optimization into + + align:start position:0% +turn that constrained optimization into + + + align:start position:0% +turn that constrained optimization into +an unconstrained + + align:start position:0% +an unconstrained + + + align:start position:0% +an unconstrained +optimization okay and for this + + align:start position:0% + + + + align:start position:0% + +problem um we can build our + + align:start position:0% +problem um we can build our + + + align:start position:0% +problem um we can build our +our augmented system I'll call it J + + align:start position:0% +our augmented system I'll call it J + + + align:start position:0% +our augmented system I'll call it J +Prime here + + align:start position:0% + + + + align:start position:0% + +um which just is the same thing but + + align:start position:0% +um which just is the same thing but + + + align:start position:0% +um which just is the same thing but +taking in the constraints so first of + + align:start position:0% +taking in the constraints so first of + + + align:start position:0% +taking in the constraints so first of +all we've got a constraint on XT + + align:start position:0% +all we've got a constraint on XT + + + align:start position:0% +all we've got a constraint on XT +equaling zero so I can put that into as + + align:start position:0% +equaling zero so I can put that into as + + + align:start position:0% +equaling zero so I can put that into as +A's multiplier let's say Lambda time + + align:start position:0% +A's multiplier let's say Lambda time + + + align:start position:0% +A's multiplier let's say Lambda time +something that better equals Zer which + + align:start position:0% +something that better equals Zer which + + + align:start position:0% +something that better equals Zer which +in this case was just + + align:start position:0% +in this case was just + + + align:start position:0% +in this case was just +XT and then + + align:start position:0% +XT and then + + + align:start position:0% +XT and then +plus 0 to T 1 plus the the constraint on + + align:start position:0% +plus 0 to T 1 plus the the constraint on + + + align:start position:0% +plus 0 to T 1 plus the the constraint on +the Dynamics which I'll call it a + + align:start position:0% +the Dynamics which I'll call it a + + + align:start position:0% +the Dynamics which I'll call it a +different lrange multiplier p + + align:start position:0% +different lrange multiplier p + + + align:start position:0% +different lrange multiplier p +times f ofx + + align:start position:0% +times f ofx + + + align:start position:0% +times f ofx +uus x + + align:start position:0% +uus x + + + align:start position:0% +uus x +dot this whole thing + + align:start position:0% + + + + align:start position:0% + +DT yes how do you impose the constraint + + align:start position:0% +DT yes how do you impose the constraint + + + align:start position:0% +DT yes how do you impose the constraint +that you is awesome good question so it + + align:start position:0% +that you is awesome good question so it + + + align:start position:0% +that you is awesome good question so it +turns out um what we're going to look + + align:start position:0% +turns out um what we're going to look + + + align:start position:0% +turns out um what we're going to look +at we want to verify that this thing is + + align:start position:0% +at we want to verify that this thing is + + + align:start position:0% +at we want to verify that this thing is +optimal okay so you might you might want + + align:start position:0% +optimal okay so you might you might want + + + align:start position:0% +optimal okay so you might you might want +to put a de constraint in right in here + + align:start position:0% +to put a de constraint in right in here + + + align:start position:0% +to put a de constraint in right in here +but it actually it's more natural + + align:start position:0% +but it actually it's more natural + + + align:start position:0% +but it actually it's more natural +let me let me finish my my statement + + align:start position:0% +let me let me finish my my statement + + + align:start position:0% +let me let me finish my my statement +here the way we're going to verify + + align:start position:0% +here the way we're going to verify + + + align:start position:0% +here the way we're going to verify +optimality of this + + align:start position:0% +optimality of this + + + align:start position:0% +optimality of this +policy is by verifying that we're at a + + align:start position:0% +policy is by verifying that we're at a + + + align:start position:0% +policy is by verifying that we're at a +local minimum in J Prime right I want to + + align:start position:0% +local minimum in J Prime right I want to + + + align:start position:0% +local minimum in J Prime right I want to +say that if I change + + align:start position:0% +say that if I change + + + align:start position:0% +say that if I change +X if I change U if I change p in any + + align:start position:0% +X if I change U if I change p in any + + + align:start position:0% +X if I change U if I change p in any +admissible + + align:start position:0% +admissible + + + align:start position:0% +admissible +way then J is going to change J jange + + align:start position:0% +way then J is going to change J jange + + + align:start position:0% +way then J is going to change J jange +sorry small changes in here is not going + + align:start position:0% +sorry small changes in here is not going + + + align:start position:0% +sorry small changes in here is not going +to change this I'm at a local Minima in + + align:start position:0% +to change this I'm at a local Minima in + + + align:start position:0% +to change this I'm at a local Minima in +J Prime that's the um that's the minimum + + align:start position:0% +J Prime that's the um that's the minimum + + + align:start position:0% +J Prime that's the um that's the minimum +principle idea right I just want my if + + align:start position:0% +principle idea right I just want my if + + + align:start position:0% +principle idea right I just want my if +I'm at a minimum of function the + + align:start position:0% +I'm at a minimum of function the + + + align:start position:0% +I'm at a minimum of function the +gradient is zero in the lrange + + align:start position:0% +gradient is zero in the lrange + + + align:start position:0% +gradient is zero in the lrange +multiplier the minimum minimum of this + + align:start position:0% +multiplier the minimum minimum of this + + + align:start position:0% +multiplier the minimum minimum of this +augmented function the the gradient had + + align:start position:0% +augmented function the the gradient had + + + align:start position:0% +augmented function the the gradient had +to be zero so if I change any of these I + + align:start position:0% +to be zero so if I change any of these I + + + align:start position:0% +to be zero so if I change any of these I +want that to be that change to to be + + align:start position:0% +want that to be that change to to be + + + align:start position:0% +want that to be that change to to be +zero + + align:start position:0% +zero + + + align:start position:0% +zero +okay so it turns out that um the more + + align:start position:0% +okay so it turns out that um the more + + + align:start position:0% +okay so it turns out that um the more +natural way to uh to look at um this + + align:start position:0% +natural way to uh to look at um this + + + align:start position:0% +natural way to uh to look at um this +Bound in U is by not changing not + + align:start position:0% +Bound in U is by not changing not + + + align:start position:0% +Bound in U is by not changing not +allowing you to change outside of that + + align:start position:0% +allowing you to change outside of that + + + align:start position:0% +allowing you to change outside of that +regime + + align:start position:0% + + + + align:start position:0% + +okay this is actually fairly procedural + + align:start position:0% +okay this is actually fairly procedural + + + align:start position:0% +okay this is actually fairly procedural +right so you end up doing this this + + align:start position:0% +right so you end up doing this this + + + align:start position:0% +right so you end up doing this this +calculus of variations on J + + align:start position:0% +calculus of variations on J + + + align:start position:0% +calculus of variations on J +Prime but I actually I made a call + + align:start position:0% +Prime but I actually I made a call + + + align:start position:0% +Prime but I actually I made a call +earlier today I think it's going to if I + + align:start position:0% +earlier today I think it's going to if I + + + align:start position:0% +earlier today I think it's going to if I +if I do it right now in the beginning of + + align:start position:0% +if I do it right now in the beginning of + + + align:start position:0% +if I do it right now in the beginning of +class I'm going to lose you to I mean + + align:start position:0% +class I'm going to lose you to I mean + + + align:start position:0% +class I'm going to lose you to I mean +I'm going bore you and uh and uh and + + align:start position:0% +I'm going bore you and uh and uh and + + + align:start position:0% +I'm going bore you and uh and uh and +lose you but it's in the notes and it's + + align:start position:0% +lose you but it's in the notes and it's + + + align:start position:0% +lose you but it's in the notes and it's +clean um so so I'm going to going to + + align:start position:0% +clean um so so I'm going to going to + + + align:start position:0% +clean um so so I'm going to going to +leave that hanging and let you look at + + align:start position:0% +leave that hanging and let you look at + + + align:start position:0% +leave that hanging and let you look at +it in the notes without typos on that I + + align:start position:0% +it in the notes without typos on that I + + + align:start position:0% +it in the notes without typos on that I +might put up on the board + + align:start position:0% +might put up on the board + + + align:start position:0% +might put up on the board +okay because I want to move on to the um + + align:start position:0% +okay because I want to move on to the um + + + align:start position:0% +okay because I want to move on to the um +to the dynamic programming view of the + + align:start position:0% +to the dynamic programming view of the + + + align:start position:0% +to the dynamic programming view of the +world right sort of the other possible + + align:start position:0% +world right sort of the other possible + + + align:start position:0% +world right sort of the other possible +solution + + align:start position:0% + + + + align:start position:0% + +technique okay + + align:start position:0% +technique okay + + + align:start position:0% +technique okay +so um today we're going to do you could + + align:start position:0% +so um today we're going to do you could + + + align:start position:0% +so um today we're going to do you could +think of it as just solution technique + + align:start position:0% +think of it as just solution technique + + + align:start position:0% +think of it as just solution technique +two here + + align:start position:0% + + + + align:start position:0% + +and it's based on um dynamic + + align:start position:0% + + + + align:start position:0% + +programming now the computer scientists + + align:start position:0% +programming now the computer scientists + + + align:start position:0% +programming now the computer scientists +in the audience say I know not dynamic + + align:start position:0% +in the audience say I know not dynamic + + + align:start position:0% +in the audience say I know not dynamic +programming um it's how I find the + + align:start position:0% +programming um it's how I find the + + + align:start position:0% +programming um it's how I find the +shortest path between point a and point + + align:start position:0% +shortest path between point a and point + + + align:start position:0% +shortest path between point a and point +B without um using memory and things + + align:start position:0% +B without um using memory and things + + + align:start position:0% +B without um using memory and things +like that and you're exactly right + + align:start position:0% +like that and you're exactly right + + + align:start position:0% +like that and you're exactly right +that's exactly what it is it happens + + align:start position:0% +that's exactly what it is it happens + + + align:start position:0% +that's exactly what it is it happens +that the dynamic programming has a + + align:start position:0% +that the dynamic programming has a + + + align:start position:0% +that the dynamic programming has a +slightly bigger + + align:start position:0% +slightly bigger + + + align:start position:0% +slightly bigger +um footprint in the world it uh there's + + align:start position:0% +um footprint in the world it uh there's + + + align:start position:0% +um footprint in the world it uh there's +a continuous form of dynamic + + align:start position:0% +a continuous form of dynamic + + + align:start position:0% +a continuous form of dynamic +programming okay so so a graph search is + + align:start position:0% +programming okay so so a graph search is + + + align:start position:0% +programming okay so so a graph search is +a very discreet form of dynamic + + align:start position:0% +a very discreet form of dynamic + + + align:start position:0% +a very discreet form of dynamic +programming so I'm going to start sort + + align:start position:0% +programming so I'm going to start sort + + + align:start position:0% +programming so I'm going to start sort +of I'm actually going to work from the + + align:start position:0% +of I'm actually going to work from the + + + align:start position:0% +of I'm actually going to work from the +graph search sort of view of the world + + align:start position:0% +graph search sort of view of the world + + + align:start position:0% +graph search sort of view of the world +but to make the continuous form that + + align:start position:0% +but to make the continuous form that + + + align:start position:0% +but to make the continuous form that +works for these continuous dynamical + + align:start position:0% +works for these continuous dynamical + + + align:start position:0% +works for these continuous dynamical +systems + + align:start position:0% +systems + + + align:start position:0% +systems +okay and we're going to use this um to + + align:start position:0% +okay and we're going to use this um to + + + align:start position:0% +okay and we're going to use this um to +to investigate a different cost + + align:start position:0% + + + + align:start position:0% + +function which is + + align:start position:0% + + + + align:start position:0% + +just + + align:start position:0% +just + + + align:start position:0% +just +this still subject to the + + align:start position:0% + + + + align:start position:0% + +Dynamics which in this case was the + + align:start position:0% +Dynamics which in this case was the + + + align:start position:0% +Dynamics which in this case was the +linear + + align:start position:0% + + + + align:start position:0% + +Dynamics + + align:start position:0% + + + + align:start position:0% + +okay so before we worry about solving it + + align:start position:0% +okay so before we worry about solving it + + + align:start position:0% +okay so before we worry about solving it +let's take a minute to decide if it's a + + align:start position:0% +let's take a minute to decide if it's a + + + align:start position:0% +let's take a minute to decide if it's a +reasonable cost + + align:start position:0% + + + + align:start position:0% + +function it's different in a couple of + + align:start position:0% +function it's different in a couple of + + + align:start position:0% +function it's different in a couple of +ways right uh first of all there's no + + align:start position:0% +ways right uh first of all there's no + + + align:start position:0% +ways right uh first of all there's no +hard limit on U but I do penalize for + + align:start position:0% +hard limit on U but I do penalize for + + + align:start position:0% +hard limit on U but I do penalize for +you being away from zero + + align:start position:0% + + + + align:start position:0% + +right so it's sort of a softer a penalty + + align:start position:0% +right so it's sort of a softer a penalty + + + align:start position:0% +right so it's sort of a softer a penalty +on you not a hard limit okay and then + + align:start position:0% +on you not a hard limit okay and then + + + align:start position:0% +on you not a hard limit okay and then +these + + align:start position:0% +these + + + align:start position:0% +these +terms are penalizing it from being the + + align:start position:0% +terms are penalizing it from being the + + + align:start position:0% +terms are penalizing it from being the +system from being away from the origin + + align:start position:0% +system from being away from the origin + + + align:start position:0% +system from being away from the origin +right and instead of going for some + + align:start position:0% +right and instead of going for some + + + align:start position:0% +right and instead of going for some +finite time and minimizing time I'm + + align:start position:0% +finite time and minimizing time I'm + + + align:start position:0% +finite time and minimizing time I'm +going to go for an infinite + + align:start position:0% +going to go for an infinite + + + align:start position:0% +going to go for an infinite +Horizon so the only way to drive this + + align:start position:0% +Horizon so the only way to drive this + + + align:start position:0% +Horizon so the only way to drive this +thing um the only way actually for J to + + align:start position:0% +thing um the only way actually for J to + + + align:start position:0% +thing um the only way actually for J to +be a finite cost over this this infinite + + align:start position:0% +be a finite cost over this this infinite + + + align:start position:0% +be a finite cost over this this infinite +integral is if q and Q dot get to zero + + align:start position:0% +integral is if q and Q dot get to zero + + + align:start position:0% +integral is if q and Q dot get to zero +and you do U of zero at zero + + align:start position:0% +and you do U of zero at zero + + + align:start position:0% +and you do U of zero at zero +okay otherwise this thing's going to + + align:start position:0% +okay otherwise this thing's going to + + + align:start position:0% +okay otherwise this thing's going to +blow up it's going to be an infinite + + align:start position:0% +blow up it's going to be an infinite + + + align:start position:0% +blow up it's going to be an infinite +integral okay so the solution had better + + align:start position:0% +integral okay so the solution had better + + + align:start position:0% +integral okay so the solution had better +result in us getting to the origin to + + align:start position:0% +result in us getting to the origin to + + + align:start position:0% +result in us getting to the origin to +turns out okay but I'm not trying to + + align:start position:0% +turns out okay but I'm not trying to + + + align:start position:0% +turns out okay but I'm not trying to +explicitly minimize the time I'm just + + align:start position:0% +explicitly minimize the time I'm just + + + align:start position:0% +explicitly minimize the time I'm just +penalizing it for being away and I'm + + align:start position:0% +penalizing it for being away and I'm + + + align:start position:0% +penalizing it for being away and I'm +penalizing it for taking + + align:start position:0% +penalizing it for taking + + + align:start position:0% +penalizing it for taking +action Okay + + align:start position:0% +action Okay + + + align:start position:0% +action Okay +now what's the name of + + align:start position:0% +now what's the name of + + + align:start position:0% +now what's the name of +this type of + + align:start position:0% +this type of + + + align:start position:0% +this type of +control who knows + + align:start position:0% +control who knows + + + align:start position:0% +control who knows +it I think I yeah lqr right so this is a + + align:start position:0% +it I think I yeah lqr right so this is a + + + align:start position:0% +it I think I yeah lqr right so this is a +linear quadratic + + align:start position:0% + + + + align:start position:0% + +regulator okay it's a staple of it's + + align:start position:0% +regulator okay it's a staple of it's + + + align:start position:0% +regulator okay it's a staple of it's +sort of the best the most used result um + + align:start position:0% +sort of the best the most used result um + + + align:start position:0% +sort of the best the most used result um +from optimal control everybody opens up + + align:start position:0% +from optimal control everybody opens up + + + align:start position:0% +from optimal control everybody opens up +mat lab and calls lqr um but you're + + align:start position:0% +mat lab and calls lqr um but you're + + + align:start position:0% +mat lab and calls lqr um but you're +going to understand + + align:start position:0% +going to understand + + + align:start position:0% +going to understand +it okay + + align:start position:0% +it okay + + + align:start position:0% +it okay +um + + align:start position:0% +um + + + align:start position:0% +um +good but to do lqr um to understand how + + align:start position:0% +good but to do lqr um to understand how + + + align:start position:0% +good but to do lqr um to understand how +that derivation Works um we got to do + + align:start position:0% +that derivation Works um we got to do + + + align:start position:0% +that derivation Works um we got to do +we're going to go through dynamic + + align:start position:0% + + + + align:start position:0% + +programming use the + + align:start position:0% +programming use the + + + align:start position:0% +programming use the +same function there as well awesome okay + + align:start position:0% +same function there as well awesome okay + + + align:start position:0% +same function there as well awesome okay +so why don't I put that cost function + + align:start position:0% +so why don't I put that cost function + + + align:start position:0% +so why don't I put that cost function +down and just do pontryagin's minimum + + align:start position:0% +down and just do pontryagin's minimum + + + align:start position:0% +down and just do pontryagin's minimum +principle okay um there's only one sort + + align:start position:0% +principle okay um there's only one sort + + + align:start position:0% +principle okay um there's only one sort +of subtle reason which is that that's an + + align:start position:0% +of subtle reason which is that that's an + + + align:start position:0% +of subtle reason which is that that's an +infinite + + align:start position:0% +infinite + + + align:start position:0% +infinite +Horizon cost okay + + align:start position:0% + + + + align:start position:0% + +so I was I was going to say this to the + + align:start position:0% +so I was I was going to say this to the + + + align:start position:0% +so I was I was going to say this to the +end but let's have this discussion now + + align:start position:0% +end but let's have this discussion now + + + align:start position:0% +end but let's have this discussion now +so um so this is an infinite Horizon um + + align:start position:0% +so um so this is an infinite Horizon um + + + align:start position:0% +so um so this is an infinite Horizon um +pontryagin is used to to verify the the + + align:start position:0% +pontryagin is used to to verify the the + + + align:start position:0% +pontryagin is used to to verify the the +optimality of a of an some finite + + align:start position:0% +optimality of a of an some finite + + + align:start position:0% +optimality of a of an some finite +integral + + align:start position:0% +integral + + + align:start position:0% +integral +okay so so let's compare and + + align:start position:0% +okay so so let's compare and + + + align:start position:0% +okay so so let's compare and +well I know you know uh value dynamic + + align:start position:0% +well I know you know uh value dynamic + + + align:start position:0% +well I know you know uh value dynamic +programming so maybe let me say what + + align:start position:0% +programming so maybe let me say what + + + align:start position:0% +programming so maybe let me say what +dynamic programming is and then I'll + + align:start position:0% +dynamic programming is and then I'll + + + align:start position:0% +dynamic programming is and then I'll +contrast them yeah yeah + + align:start position:0% + + + + align:start position:0% + +okay but the people sort of + + align:start position:0% +okay but the people sort of + + + align:start position:0% +okay but the people sort of +um I just want to understand what + + align:start position:0% +um I just want to understand what + + + align:start position:0% +um I just want to understand what +happened we've got two different cost + + align:start position:0% +happened we've got two different cost + + + align:start position:0% +happened we've got two different cost +functions two different solution + + align:start position:0% +functions two different solution + + + align:start position:0% +functions two different solution +techniques for now and we're going to + + align:start position:0% +techniques for now and we're going to + + + align:start position:0% +techniques for now and we're going to +address in a few minutes why I I did + + align:start position:0% +address in a few minutes why I I did + + + align:start position:0% +address in a few minutes why I I did +different solution techniques for the + + align:start position:0% +different solution techniques for the + + + align:start position:0% +different solution techniques for the +different cost functions but I hope they + + align:start position:0% +different cost functions but I hope they + + + align:start position:0% +different cost functions but I hope they +both seem like sort of reasonable cost + + align:start position:0% +both seem like sort of reasonable cost + + + align:start position:0% +both seem like sort of reasonable cost +functions if I want to get my system to + + align:start position:0% +functions if I want to get my system to + + + align:start position:0% +functions if I want to get my system to +the origin okay different we're going to + + align:start position:0% +the origin okay different we're going to + + + align:start position:0% +the origin okay different we're going to +look at what the result is the different + + align:start position:0% +look at what the result is the different + + + align:start position:0% +look at what the result is the different +results and actually something I want to + + align:start position:0% +results and actually something I want to + + + align:start position:0% +results and actually something I want to +leave you with is that you can you can + + align:start position:0% +leave you with is that you can you can + + + align:start position:0% +leave you with is that you can you can +in fact do lots of different + + align:start position:0% +in fact do lots of different + + + align:start position:0% +in fact do lots of different +combinations of these things you could + + align:start position:0% +combinations of these things you could + + + align:start position:0% +combinations of these things you could +do quadratic costs and try to have some + + align:start position:0% +do quadratic costs and try to have some + + + align:start position:0% +do quadratic costs and try to have some +minimum time there's lot you sort of + + align:start position:0% +minimum time there's lot you sort of + + + align:start position:0% +minimum time there's lot you sort of +there's lots of lots and lots of ways to + + align:start position:0% +there's lots of lots and lots of ways to + + + align:start position:0% +there's lots of lots and lots of ways to +formulate these cost functions these are + + align:start position:0% +formulate these cost functions these are + + + align:start position:0% +formulate these cost functions these are +two sort of um examples but you can do + + align:start position:0% +two sort of um examples but you can do + + + align:start position:0% +two sort of um examples but you can do +minimum time lqr you can do all these + + align:start position:0% +minimum time lqr you can do all these + + + align:start position:0% +minimum time lqr you can do all these +things okay but with the way we're going + + align:start position:0% +things okay but with the way we're going + + + align:start position:0% +things okay but with the way we're going +to derive the lqr controller + + align:start position:0% +to derive the lqr controller + + + align:start position:0% +to derive the lqr controller +um is by thinking about dynamic + + align:start position:0% +um is by thinking about dynamic + + + align:start position:0% +um is by thinking about dynamic +programming and to do that let me start + + align:start position:0% +programming and to do that let me start + + + align:start position:0% +programming and to do that let me start +with the discrete world where people + + align:start position:0% +with the discrete world where people + + + align:start position:0% +with the discrete world where people +where it makes sense + + align:start position:0% +where it makes sense + + + align:start position:0% +where it makes sense +um so let's imagine I have a discreete + + align:start position:0% +um so let's imagine I have a discreete + + + align:start position:0% +um so let's imagine I have a discreete +Time + + align:start position:0% + + + + align:start position:0% + +system um so X of n + 1 is f of + + align:start position:0% +system um so X of n + 1 is f of + + + align:start position:0% +system um so X of n + 1 is f of +xn + + align:start position:0% +xn + + + align:start position:0% +xn +un + + align:start position:0% + + + + align:start position:0% + +n and I have some cost + + align:start position:0% +n and I have some cost + + + align:start position:0% +n and I have some cost +function um now remember in the + + align:start position:0% +function um now remember in the + + + align:start position:0% +function um now remember in the +pontryagin minimum principle we show + + align:start position:0% +pontryagin minimum principle we show + + + align:start position:0% +pontryagin minimum principle we show +that there's a sort of a general form + + align:start position:0% +that there's a sort of a general form + + + align:start position:0% +that there's a sort of a general form +that a lot of these cost functions take + + align:start position:0% +that a lot of these cost functions take + + + align:start position:0% +that a lot of these cost functions take +in the discret form it's um h + + align:start position:0% +in the discret form it's um h + + + align:start position:0% +in the discret form it's um h +of X at capital + + align:start position:0% +of X at capital + + + align:start position:0% +of X at capital +n + + align:start position:0% +n + + + align:start position:0% +n +plus a sum instead of a integral right + + align:start position:0% +plus a sum instead of a integral right + + + align:start position:0% +plus a sum instead of a integral right +of Nal 0 + + align:start position:0% +of Nal 0 + + + align:start position:0% +of Nal 0 +to + + align:start position:0% +to + + + align:start position:0% +to +nus1 G of + + align:start position:0% +nus1 G of + + + align:start position:0% +nus1 G of +xn unu + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% + + + + align:start position:0% + +okay now + + align:start position:0% +okay now + + + align:start position:0% +okay now +um again I said this this + + align:start position:0% +um again I said this this + + + align:start position:0% +um again I said this this +sort of additive form of the cost + + align:start position:0% +sort of additive form of the cost + + + align:start position:0% +sort of additive form of the cost +functions um is pretty common and you're + + align:start position:0% +functions um is pretty common and you're + + + align:start position:0% +functions um is pretty common and you're +going to see right now one of the + + align:start position:0% +going to see right now one of the + + + align:start position:0% +going to see right now one of the +reasons why the great thing about having + + align:start position:0% +reasons why the great thing about having + + + align:start position:0% +reasons why the great thing about having +these costs that that accumulate + + align:start position:0% +these costs that that accumulate + + + align:start position:0% +these costs that that accumulate +additively over the trajectory is that I + + align:start position:0% +additively over the trajectory is that I + + + align:start position:0% +additively over the trajectory is that I +can make a + + align:start position:0% +can make a + + + align:start position:0% +can make a +recursive um form of this equation okay + + align:start position:0% +recursive um form of this equation okay + + + align:start position:0% +recursive um form of this equation okay +so in particular if I so so I should + + align:start position:0% +so in particular if I so so I should + + + align:start position:0% +so in particular if I so so I should +call this really what I've been calling + + align:start position:0% +call this really what I've been calling + + + align:start position:0% +call this really what I've been calling +J that's really um the J of being at x0 + + align:start position:0% +J that's really um the J of being at x0 + + + align:start position:0% +J that's really um the J of being at x0 +at time + + align:start position:0% + + + + align:start position:0% + +0 and I can I can compute um J of being + + align:start position:0% +0 and I can I can compute um J of being + + + align:start position:0% +0 and I can I can compute um J of being +at x0 time0 and incurring the rest of + + align:start position:0% +at x0 time0 and incurring the rest of + + + align:start position:0% +at x0 time0 and incurring the rest of +the cost + + align:start position:0% +the cost + + + align:start position:0% +the cost +recursively by looking at what it would + + align:start position:0% +recursively by looking at what it would + + + align:start position:0% +recursively by looking at what it would +be like to be at some State X at time + + align:start position:0% + + + + align:start position:0% + +n and that in this case is just h of + + align:start position:0% +n and that in this case is just h of + + + align:start position:0% +n and that in this case is just h of +X of + + align:start position:0% +X of + + + align:start position:0% +X of +N and then thinking about what it would + + align:start position:0% +N and then thinking about what it would + + + align:start position:0% +N and then thinking about what it would +be like at to be at some J of X at n + + align:start position:0% +be like at to be at some J of X at n + + + align:start position:0% +be like at to be at some J of X at n +minus + + align:start position:0% +minus + + + align:start position:0% +minus +one + + align:start position:0% +one + + + align:start position:0% +one +right and that's going to + + align:start position:0% +right and that's going to + + + align:start position:0% +right and that's going to +be G of X + + align:start position:0% +be G of X + + + align:start position:0% +be G of X +nus1 U of + + align:start position:0% +nus1 U of + + + align:start position:0% +nus1 U of +nus1 plus h of + + align:start position:0% + + + + align:start position:0% + +xn + + align:start position:0% + + + + align:start position:0% + +let me be even more careful and I'm + + align:start position:0% +let me be even more careful and I'm + + + align:start position:0% +let me be even more careful and I'm +going to say let's let's evaluate the + + align:start position:0% +going to say let's let's evaluate the + + + align:start position:0% +going to say let's let's evaluate the +cost of running a particular + + align:start position:0% + + + + align:start position:0% + +policy unu + + align:start position:0% +policy unu + + + align:start position:0% +policy unu +n is just some Pi of J of + + align:start position:0% + + + + align:start position:0% + +xn + + align:start position:0% + + + + align:start position:0% + +okay so um why did I put x0 here that + + align:start position:0% +okay so um why did I put x0 here that + + + align:start position:0% +okay so um why did I put x0 here that +was intentional I I'm trying to make x z + + align:start position:0% +was intentional I I'm trying to make x z + + + align:start position:0% +was intentional I I'm trying to make x z +the variable that fits in here here x is + + align:start position:0% +the variable that fits in here here x is + + + align:start position:0% +the variable that fits in here here x is +the variable that fits in here but + + align:start position:0% +the variable that fits in here but + + + align:start position:0% +the variable that fits in here but +you're right I could be a little bit + + align:start position:0% +you're right I could be a little bit + + + align:start position:0% +you're right I could be a little bit +more I should be more careful so now j a + + align:start position:0% +more I should be more careful so now j a + + + align:start position:0% +more I should be more careful so now j a +function of this variable X at time n + + align:start position:0% +function of this variable X at time n + + + align:start position:0% +function of this variable X at time n +should really just be h of X yeah good + + align:start position:0% +should really just be h of X yeah good + + + align:start position:0% +should really just be h of X yeah good +so then this is um I could say I could + + align:start position:0% +so then this is um I could say I could + + + align:start position:0% +so then this is um I could say I could +say it this way the other way I could + + align:start position:0% +say it this way the other way I could + + + align:start position:0% +say it this way the other way I could +say it is J at x - 1 = x maybe that's + + align:start position:0% +say it is J at x - 1 = x maybe that's + + + align:start position:0% +say it is J at x - 1 = x maybe that's +the best way to to rectify + + align:start position:0% + + + + align:start position:0% + +it okay and when I'm when I'm evaluating + + align:start position:0% +it okay and when I'm when I'm evaluating + + + align:start position:0% +it okay and when I'm when I'm evaluating +the cost of of a particular + + align:start position:0% +the cost of of a particular + + + align:start position:0% +the cost of of a particular +um particular policy I'm going to use + + align:start position:0% +um particular policy I'm going to use + + + align:start position:0% +um particular policy I'm going to use +the notation J + + align:start position:0% + + + + align:start position:0% + +Pi here to say this is the cost I should + + align:start position:0% +Pi here to say this is the cost I should + + + align:start position:0% +Pi here to say this is the cost I should +expect to receive given I'm in some + + align:start position:0% +expect to receive given I'm in some + + + align:start position:0% +expect to receive given I'm in some +State + + align:start position:0% +State + + + align:start position:0% +State +X to make it even more satisfying let's + + align:start position:0% +X to make it even more satisfying let's + + + align:start position:0% +X to make it even more satisfying let's +just be the same everywhere this is + + align:start position:0% +just be the same everywhere this is + + + align:start position:0% +just be the same everywhere this is +x0 and here I'll say x0 equals my + + align:start position:0% +x0 and here I'll say x0 equals my + + + align:start position:0% +x0 and here I'll say x0 equals my +X okay if I'm in some State X at Time + + align:start position:0% +X okay if I'm in some State X at Time + + + align:start position:0% +X okay if I'm in some State X at Time +Zero executing policy Pi I'm going to + + align:start position:0% +Zero executing policy Pi I'm going to + + + align:start position:0% +Zero executing policy Pi I'm going to +incur this cost right if I'm at in some + + align:start position:0% +incur this cost right if I'm at in some + + + align:start position:0% +incur this cost right if I'm at in some +State X um at time n incurring this uh + + align:start position:0% +State X um at time n incurring this uh + + + align:start position:0% +State X um at time n incurring this uh +taking this policy I'm going to I'm + + align:start position:0% +taking this policy I'm going to I'm + + + align:start position:0% +taking this policy I'm going to I'm +going to get + + align:start position:0% +going to get + + + align:start position:0% +going to get +this here I'm going to get this and even + + align:start position:0% +this here I'm going to get this and even + + + align:start position:0% +this here I'm going to get this and even +when I'm executing um policy Pi I can + + align:start position:0% +when I'm executing um policy Pi I can + + + align:start position:0% +when I'm executing um policy Pi I can +even furthermore say that + + align:start position:0% +even furthermore say that + + + align:start position:0% +even furthermore say that +xn is f of xn minus + + align:start position:0% +xn is f of xn minus + + + align:start position:0% +xn is f of xn minus +1 um Pi of x nus + + align:start position:0% + + + + align:start position:0% + +one it's probably impossible to read in + + align:start position:0% +one it's probably impossible to read in + + + align:start position:0% +one it's probably impossible to read in +that + + align:start position:0% +that + + + align:start position:0% +that +corner + + align:start position:0% + + + + align:start position:0% + +okay so you can see where I'm going with + + align:start position:0% + + + + align:start position:0% + +it it's pretty easy to see that + + align:start position:0% +it it's pretty easy to see that + + + align:start position:0% +it it's pretty easy to see that +um J Pi of X at some end + + align:start position:0% + + + + align:start position:0% + +is just the one-step cost G of X + + align:start position:0% +is just the one-step cost G of X + + + align:start position:0% +is just the one-step cost G of X +and unu + + align:start position:0% +and unu + + + align:start position:0% +and unu +N plus the cost I expect to + + align:start position:0% +N plus the cost I expect to + + + align:start position:0% +N plus the cost I expect to +see given I at + + align:start position:0% +see given I at + + + align:start position:0% +see given I at +um xn + + + align:start position:0% + + + + align:start position:0% + +1 at time n plus + + align:start position:0% +1 at time n plus + + + align:start position:0% +1 at time n plus +one + + align:start position:0% + + + + align:start position:0% + +okay so the reason we like these + + align:start position:0% +okay so the reason we like these + + + align:start position:0% +okay so the reason we like these +integral costs or the the sum of costs + + align:start position:0% +integral costs or the the sum of costs + + + align:start position:0% +integral costs or the the sum of costs +in the uh uh discrete time case is + + align:start position:0% +in the uh uh discrete time case is + + + align:start position:0% +in the uh uh discrete time case is +because I can do these + + align:start position:0% +because I can do these + + + align:start position:0% +because I can do these +recursive computations and the same + + align:start position:0% +recursive computations and the same + + + align:start position:0% +recursive computations and the same +thing true if I look at if I Define what + + align:start position:0% +thing true if I look at if I Define what + + + align:start position:0% +thing true if I look at if I Define what +the optimal cost is okay + + align:start position:0% +the optimal cost is okay + + + align:start position:0% +the optimal cost is okay +so let's now Define J star to be the the + + align:start position:0% +so let's now Define J star to be the the + + + align:start position:0% +so let's now Define J star to be the the +cost I incur if I follow the optimal + + align:start position:0% + + + + align:start position:0% + +policy + + align:start position:0% + + + + align:start position:0% + +which is pi + + align:start position:0% + + + + align:start position:0% + +star what turns out same thing + + align:start position:0% + + + + align:start position:0% + +works but now + + align:start position:0% +works but now + + + align:start position:0% +works but now +there's a an extra term + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% + + + + align:start position:0% + +okay so it's easy to see that the um the + + align:start position:0% +okay so it's easy to see that the um the + + + align:start position:0% +okay so it's easy to see that the um the +cost to go of following a particular + + align:start position:0% +cost to go of following a particular + + + align:start position:0% +cost to go of following a particular +policy is + + align:start position:0% +policy is + + + align:start position:0% +policy is +recursive it's more surprising that the + + align:start position:0% +recursive it's more surprising that the + + + align:start position:0% +recursive it's more surprising that the +uh cost to go of the optimal policy is + + align:start position:0% +uh cost to go of the optimal policy is + + + align:start position:0% +uh cost to go of the optimal policy is +equally recursive with a simple form + + align:start position:0% +equally recursive with a simple form + + + align:start position:0% +equally recursive with a simple form +like this Min over + + align:start position:0% +like this Min over + + + align:start position:0% +like this Min over +U + + align:start position:0% +U + + + align:start position:0% +U +okay and this actually follows from + + align:start position:0% +okay and this actually follows from + + + align:start position:0% +okay and this actually follows from +something called the principle of + + align:start position:0% + + + + align:start position:0% + +optimality anybody see the principle of + + align:start position:0% +optimality anybody see the principle of + + + align:start position:0% +optimality anybody see the principle of +optimality before + + align:start position:0% +optimality before + + + align:start position:0% +optimality before +okay it says + + align:start position:0% +okay it says + + + align:start position:0% +okay it says +that if I want to be optimal over some + + align:start position:0% +that if I want to be optimal over some + + + align:start position:0% +that if I want to be optimal over some +trajectory I'd better be optimal over + + align:start position:0% +trajectory I'd better be optimal over + + + align:start position:0% +trajectory I'd better be optimal over +from the end of that trajectory so um if + + align:start position:0% +from the end of that trajectory so um if + + + align:start position:0% +from the end of that trajectory so um if +I want to be optimal for the last uh for + + align:start position:0% +I want to be optimal for the last uh for + + + align:start position:0% +I want to be optimal for the last uh for +from n minus 2 to the end then I'd + + align:start position:0% +from n minus 2 to the end then I'd + + + align:start position:0% +from n minus 2 to the end then I'd +better be optimal from n minus one to + + align:start position:0% +better be optimal from n minus one to + + + align:start position:0% +better be optimal from n minus one to +the end okay so it turns out if I act + + align:start position:0% +the end okay so it turns out if I act + + + align:start position:0% +the end okay so it turns out if I act +optimally in one step by doing this Min + + align:start position:0% +optimally in one step by doing this Min + + + align:start position:0% +optimally in one step by doing this Min +over U and then follow the policy of + + align:start position:0% +over U and then follow the policy of + + + align:start position:0% +over U and then follow the policy of +optim of of acting optimally for the + + align:start position:0% +optim of of acting optimally for the + + + align:start position:0% +optim of of acting optimally for the +rest of time then that's optimal for the + + align:start position:0% +rest of time then that's optimal for the + + + align:start position:0% +rest of time then that's optimal for the +entire + + align:start position:0% +entire + + + align:start position:0% +entire +function + + align:start position:0% +function + + + align:start position:0% +function +okay + + align:start position:0% + + + + align:start position:0% + +okay okay good so + + align:start position:0% +okay okay good so + + + align:start position:0% +okay okay good so +um so we got a recursive form of this + + align:start position:0% +um so we got a recursive form of this + + + align:start position:0% +um so we got a recursive form of this +cost to go function that we exploited + + align:start position:0% +cost to go function that we exploited + + + align:start position:0% +cost to go function that we exploited +with the the additive + + align:start position:0% +with the the additive + + + align:start position:0% +with the the additive +uh thing the additive form and + + align:start position:0% +uh thing the additive form and + + + align:start position:0% +uh thing the additive form and +now the optimal policy comes straight + + align:start position:0% + + + + align:start position:0% + +out the best thing to + + align:start position:0% + + + + align:start position:0% + +do + + align:start position:0% + + + + align:start position:0% + +if you're in state X and A Time n is + + align:start position:0% +if you're in state X and A Time n is + + + align:start position:0% +if you're in state X and A Time n is +just the Argin over + + align:start position:0% + + + + align:start position:0% + +U + + align:start position:0% +U + + + align:start position:0% +U +of + + align:start position:0% +of + + + align:start position:0% +of +gxu + + align:start position:0% +gxu + + + align:start position:0% +gxu +plus J + + align:start position:0% +plus J + + + align:start position:0% +plus J +star xn + + + align:start position:0% + + + + align:start position:0% + +1 n + + + align:start position:0% +1 n + + + + align:start position:0% +1 n + +one with that same + + align:start position:0% +one with that same + + + align:start position:0% +one with that same +xn + one defined + + align:start position:0% + + + + align:start position:0% + +by + + align:start position:0% + + + + align:start position:0% + +okay so in discreete time optimal + + align:start position:0% +okay so in discreete time optimal + + + align:start position:0% +okay so in discreete time optimal +control is Trivial if you have an + + align:start position:0% +control is Trivial if you have an + + + align:start position:0% +control is Trivial if you have an +additive cost function all you have to + + align:start position:0% +additive cost function all you have to + + + align:start position:0% +additive cost function all you have to +do is figure out what your cost is at + + align:start position:0% +do is figure out what your cost is at + + + align:start position:0% +do is figure out what your cost is at +the end and then go back one step do the + + align:start position:0% +the end and then go back one step do the + + + align:start position:0% +the end and then go back one step do the +thing that acts that in one step + + align:start position:0% +thing that acts that in one step + + + align:start position:0% +thing that acts that in one step +minimizes the cost and gets me to the + + align:start position:0% +minimizes the cost and gets me to the + + + align:start position:0% +minimizes the cost and gets me to the +lowest possible cost in the future and + + align:start position:0% +lowest possible cost in the future and + + + align:start position:0% +lowest possible cost in the future and +if I just do that recursively backwards + + align:start position:0% +if I just do that recursively backwards + + + align:start position:0% +if I just do that recursively backwards +I come up with the optimal policy that + + align:start position:0% +I come up with the optimal policy that + + + align:start position:0% +I come up with the optimal policy that +gets me from from any X in end steps to + + align:start position:0% +gets me from from any X in end steps to + + + align:start position:0% +gets me from from any X in end steps to +the to the end + + align:start position:0% + + + + align:start position:0% + +okay does that make + + align:start position:0% +okay does that make + + + align:start position:0% +okay does that make +sense ask + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +do people buy that does that is that + + align:start position:0% +do people buy that does that is that + + + align:start position:0% +do people buy that does that is that +obvious or does that need more + + align:start position:0% + + + + align:start position:0% + +explanation okay ask questions if you + + align:start position:0% +explanation okay ask questions if you + + + align:start position:0% +explanation okay ask questions if you +have them all right so + + align:start position:0% + + + + align:start position:0% + +um we're going to we're going to use the + + align:start position:0% +um we're going to we're going to use the + + + align:start position:0% +um we're going to we're going to use the +discret time form again when we get to + + align:start position:0% +discret time form again when we get to + + + align:start position:0% +discret time form again when we get to +the algorithms but I'm I'm I'm trying to + + align:start position:0% +the algorithms but I'm I'm I'm trying to + + + align:start position:0% +the algorithms but I'm I'm I'm trying to +use it today to Leap Frog into the The + + align:start position:0% +use it today to Leap Frog into the The + + + align:start position:0% +use it today to Leap Frog into the The +Continuous time um conditions for + + align:start position:0% +Continuous time um conditions for + + + align:start position:0% +Continuous time um conditions for +optimality + + align:start position:0% +optimality + + + align:start position:0% +optimality +okay so what happens if we now do the + + align:start position:0% +okay so what happens if we now do the + + + align:start position:0% +okay so what happens if we now do the +same sort of discrete time thinking but + + align:start position:0% +same sort of discrete time thinking but + + + align:start position:0% +same sort of discrete time thinking but +do it in the limit where the the time + + align:start position:0% +do it in the limit where the the time + + + align:start position:0% +do it in the limit where the the time +between steps goes to to zero + + align:start position:0% +between steps goes to to zero + + + align:start position:0% +between steps goes to to zero +okay so let me try to do a the limiting + + align:start position:0% +okay so let me try to do a the limiting + + + align:start position:0% +okay so let me try to do a the limiting +argument to get us back to continuous + + align:start position:0% +argument to get us back to continuous + + + align:start position:0% +argument to get us back to continuous +time + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +okay now we've got + + align:start position:0% +okay now we've got + + + align:start position:0% +okay now we've got +our + + align:start position:0% +our + + + align:start position:0% +our +um our our cost function again is H of X + + align:start position:0% +um our our cost function again is H of X + + + align:start position:0% +um our our cost function again is H of X +at capital t plus the integral from zero + + align:start position:0% +at capital t plus the integral from zero + + + align:start position:0% +at capital t plus the integral from zero +to T of uh GX + + align:start position:0% +to T of uh GX + + + align:start position:0% +to T of uh GX +U + + align:start position:0% + + + + align:start position:0% + +DT this the analogous um statement from + + align:start position:0% +DT this the analogous um statement from + + + align:start position:0% +DT this the analogous um statement from +this recursion in the discreete time is + + align:start position:0% +this recursion in the discreete time is + + + align:start position:0% +this recursion in the discreete time is +that + + align:start position:0% +that + + + align:start position:0% +that +JX at + + align:start position:0% +JX at + + + align:start position:0% +JX at +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +T is going to + + align:start position:0% +T is going to + + + align:start position:0% +T is going to +be a limiting argument as DT goes to + + align:start position:0% +be a limiting argument as DT goes to + + + align:start position:0% +be a limiting argument as DT goes to +zero of the Min over + + align:start position:0% + + + + align:start position:0% + +U of G XU + + align:start position:0% + + + + align:start position:0% + +DT plus + + align:start position:0% +DT plus + + + align:start position:0% +DT plus +J X of t+ + + align:start position:0% + + + + align:start position:0% + +DT t + + + align:start position:0% + + + + align:start position:0% + +DT + + align:start position:0% +DT + + + align:start position:0% +DT +[Music] + + align:start position:0% + + + + align:start position:0% + +okay this is + + align:start position:0% +okay this is + + + align:start position:0% +okay this is +now that's just the limiting argument as + + align:start position:0% +now that's just the limiting argument as + + + align:start position:0% +now that's just the limiting argument as +DT goes to zero of the same um recursion + + align:start position:0% +DT goes to zero of the same um recursion + + + align:start position:0% +DT goes to zero of the same um recursion +recursive + + align:start position:0% + + + + align:start position:0% + +statement I'm going to + + align:start position:0% +statement I'm going to + + + align:start position:0% +statement I'm going to +approximate + + align:start position:0% +approximate + + + align:start position:0% +approximate +J X of t + + + align:start position:0% + + + + align:start position:0% + +DT as um this is J + + align:start position:0% +DT as um this is J + + + align:start position:0% +DT as um this is J +star let me not forget my stars as J + + align:start position:0% +star let me not forget my stars as J + + + align:start position:0% +star let me not forget my stars as J +star at x and + + align:start position:0% +star at x and + + + align:start position:0% +star at x and +t + + align:start position:0% + + + + align:start position:0% + +plus partial jar partial + + align:start position:0% +plus partial jar partial + + + align:start position:0% +plus partial jar partial +x x + + align:start position:0% +x x + + + align:start position:0% +x x +dot + + align:start position:0% +dot + + + align:start position:0% +dot +DT plus partial + + align:start position:0% +DT plus partial + + + align:start position:0% +DT plus partial +jar partial T + + align:start position:0% +jar partial T + + + align:start position:0% +jar partial T +DT + + align:start position:0% + + + + align:start position:0% + +right it's it's a tailor expansion of + + align:start position:0% +right it's it's a tailor expansion of + + + align:start position:0% +right it's it's a tailor expansion of +that + + align:start position:0% + + + + align:start position:0% + +term okay if I insert that back in then + + align:start position:0% +term okay if I insert that back in then + + + align:start position:0% +term okay if I insert that back in then +I + + align:start position:0% +I + + + align:start position:0% +I +have J star X of T equals the limit as + + align:start position:0% +have J star X of T equals the limit as + + + align:start position:0% +have J star X of T equals the limit as +DT goes to + + align:start position:0% +DT goes to + + + align:start position:0% +DT goes to +zero Min over + + align:start position:0% + + + + align:start position:0% + +u g + + align:start position:0% +u g + + + align:start position:0% +u g +XU + + align:start position:0% +XU + + + align:start position:0% +XU +DT + + align:start position:0% +DT + + + align:start position:0% +DT +plus partial + + align:start position:0% +plus partial + + + align:start position:0% +plus partial +jar partial x x dot is just F of XU + + align:start position:0% +jar partial x x dot is just F of XU + + + align:start position:0% +jar partial x x dot is just F of XU +remember + + align:start position:0% + + + + align:start position:0% + +DT plus partial J partial t + + align:start position:0% +DT plus partial J partial t + + + align:start position:0% +DT plus partial J partial t +DT now I left off that J X there because + + align:start position:0% +DT now I left off that J X there because + + + align:start position:0% +DT now I left off that J X there because +that actually doesn't depend on you so + + align:start position:0% +that actually doesn't depend on you so + + + align:start position:0% +that actually doesn't depend on you so +I'm going to put that out side here + + align:start position:0% +I'm going to put that out side here + + + align:start position:0% +I'm going to put that out side here +plus J X of + + align:start position:0% + + + + align:start position:0% + +T those guys + + align:start position:0% + + + + align:start position:0% + +cancel and now I've got a DT everywhere + + align:start position:0% +cancel and now I've got a DT everywhere + + + align:start position:0% +cancel and now I've got a DT everywhere +so I can actually take that out and my + + align:start position:0% +so I can actually take that out and my + + + align:start position:0% +so I can actually take that out and my +limiting argument goes + + align:start position:0% +limiting argument goes + + + align:start position:0% +limiting argument goes +away and what I'm left with is 0 = Min / + + align:start position:0% +away and what I'm left with is 0 = Min / + + + align:start position:0% +away and what I'm left with is 0 = Min / +u g of X + + align:start position:0% +u g of X + + + align:start position:0% +u g of X +U plus partial J partial X Star Plus + + align:start position:0% +U plus partial J partial X Star Plus + + + align:start position:0% +U plus partial J partial X Star Plus +partial J partial + + align:start position:0% + + + + align:start position:0% + +T this is a very famous equation it'll + + align:start position:0% +T this is a very famous equation it'll + + + align:start position:0% +T this is a very famous equation it'll +be used a + + align:start position:0% + + + + align:start position:0% + +lot it's called The Hamilton jacobe + + align:start position:0% +lot it's called The Hamilton jacobe + + + align:start position:0% +lot it's called The Hamilton jacobe +Bellman + + align:start position:0% +Bellman + + + align:start position:0% +Bellman +equation yes + + align:start position:0% + + + + align:start position:0% + +Miss + + align:start position:0% + + + + align:start position:0% + +here oh thanks good this is F of + + align:start position:0% +here oh thanks good this is F of + + + align:start position:0% +here oh thanks good this is F of +XU good thank + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +you good thank you that is the Hamilton + + align:start position:0% +you good thank you that is the Hamilton + + + align:start position:0% +you good thank you that is the Hamilton +jacobe bement + + align:start position:0% +jacobe bement + + + align:start position:0% +jacobe bement +equation often known as the + + align:start position:0% + + + + align:start position:0% + +hjb so Hamilton and jacobe are really + + align:start position:0% +hjb so Hamilton and jacobe are really + + + align:start position:0% +hjb so Hamilton and jacobe are really +old guys reelman a newer guy he was in + + align:start position:0% +old guys reelman a newer guy he was in + + + align:start position:0% +old guys reelman a newer guy he was in +the 60s or something a lot of people say + + align:start position:0% +the 60s or something a lot of people say + + + align:start position:0% +the 60s or something a lot of people say +Hamilton Bell than jacobe that doesn't + + align:start position:0% +Hamilton Bell than jacobe that doesn't + + + align:start position:0% +Hamilton Bell than jacobe that doesn't +seem quite right to me that's that's + + align:start position:0% +seem quite right to me that's that's + + + align:start position:0% +seem quite right to me that's that's +some guy in the 60s sticking his name in + + align:start position:0% +some guy in the 60s sticking his name in + + + align:start position:0% +some guy in the 60s sticking his name in +between Hamilton and Jobe so I I try to + + align:start position:0% +between Hamilton and Jobe so I I try to + + + align:start position:0% +between Hamilton and Jobe so I I try to +I would probably say hbj a couple times + + align:start position:0% +I would probably say hbj a couple times + + + align:start position:0% +I would probably say hbj a couple times +in the class but I whenever I'm thinking + + align:start position:0% +in the class but I whenever I'm thinking + + + align:start position:0% +in the class but I whenever I'm thinking +about it I say hjb + + align:start position:0% + + + + align:start position:0% + +Okay okay so we did a little bit of work + + align:start position:0% +Okay okay so we did a little bit of work + + + align:start position:0% +Okay okay so we did a little bit of work +in discreet time but the absolute output + + align:start position:0% +in discreet time but the absolute output + + + align:start position:0% +in discreet time but the absolute output +of that thinking the thing you need to + + align:start position:0% +of that thinking the thing you need to + + + align:start position:0% +of that thinking the thing you need to +remember is this + + align:start position:0% +remember is this + + + align:start position:0% +remember is this +um Hamilton jacom bman equation + + align:start position:0% +um Hamilton jacom bman equation + + + align:start position:0% +um Hamilton jacom bman equation +okay these turn out to be the conditions + + align:start position:0% +okay these turn out to be the conditions + + + align:start position:0% +okay these turn out to be the conditions +of optimality for continuous + + align:start position:0% + + + + align:start position:0% + +time let's think about what it + + align:start position:0% +time let's think about what it + + + align:start position:0% +time let's think about what it +means + + align:start position:0% +means + + + align:start position:0% +means +um so so do you have yet a picture of + + align:start position:0% +um so so do you have yet a picture of + + + align:start position:0% +um so so do you have yet a picture of +this sort of of what of what J is okay J + + align:start position:0% +this sort of of what of what J is okay J + + + align:start position:0% +this sort of of what of what J is okay J +is a cost to go it's a function over the + + align:start position:0% +is a cost to go it's a function over the + + + align:start position:0% +is a cost to go it's a function over the +entire land landscape it tells me if I'm + + align:start position:0% +entire land landscape it tells me if I'm + + + align:start position:0% +entire land landscape it tells me if I'm +in some State how much cost am I going + + align:start position:0% +in some State how much cost am I going + + + align:start position:0% +in some State how much cost am I going +to incur with my cost function as it + + align:start position:0% +to incur with my cost function as it + + + align:start position:0% +to incur with my cost function as it +runs off into into time right in the + + align:start position:0% +runs off into into time right in the + + + align:start position:0% +runs off into into time right in the +finite Horizon case it's it's just an + + align:start position:0% +finite Horizon case it's it's just an + + + align:start position:0% +finite Horizon case it's it's just an +integral to the end of time in the + + align:start position:0% +integral to the end of time in the + + + align:start position:0% +integral to the end of time in the +infinite Horizon case it's I'm I'm + + align:start position:0% +infinite Horizon case it's I'm I'm + + + align:start position:0% +infinite Horizon case it's I'm I'm +started this initial condition I run my + + align:start position:0% +started this initial condition I run my + + + align:start position:0% +started this initial condition I run my +cost function + + align:start position:0% +cost function + + + align:start position:0% +cost function +forever okay so J is a is a a cost + + align:start position:0% +forever okay so J is a is a a cost + + + align:start position:0% +forever okay so J is a is a a cost +landscape a cost to go + + align:start position:0% +landscape a cost to go + + + align:start position:0% +landscape a cost to go +landscape this this statement here says + + align:start position:0% +landscape this this statement here says + + + align:start position:0% +landscape this this statement here says +that if I move a little little bit in + + align:start position:0% +that if I move a little little bit in + + + align:start position:0% +that if I move a little little bit in +that landscape in X + + align:start position:0% +that landscape in X + + + align:start position:0% +that landscape in X +okay scaled by this x dot then the thing + + align:start position:0% +okay scaled by this x dot then the thing + + + align:start position:0% +okay scaled by this x dot then the thing +I should incur is that is my + + align:start position:0% +I should incur is that is my + + + align:start position:0% +I should incur is that is my +instantaneous + + align:start position:0% +instantaneous + + + align:start position:0% +instantaneous +cost + + align:start position:0% + + + + align:start position:0% + +okay so the way my cost landscap the the + + align:start position:0% +okay so the way my cost landscap the the + + + align:start position:0% +okay so the way my cost landscap the the +difference of being an initial condition + + align:start position:0% +difference of being an initial condition + + + align:start position:0% +difference of being an initial condition +one versus being an initial condition + + align:start position:0% +one versus being an initial condition + + + align:start position:0% +one versus being an initial condition +two if they're neighboring right goes + + align:start position:0% +two if they're neighboring right goes + + + align:start position:0% +two if they're neighboring right goes +like the cost + + align:start position:0% +like the cost + + + align:start position:0% +like the cost +function okay and some and there's the + + align:start position:0% +function okay and some and there's the + + + align:start position:0% +function okay and some and there's the +cost function the the cost to go + + align:start position:0% +cost function the the cost to go + + + align:start position:0% +cost function the the cost to go +function lives in x and it lives in + + align:start position:0% +function lives in x and it lives in + + + align:start position:0% +function lives in x and it lives in +time + + align:start position:0% + + + + align:start position:0% + +okay it's one of the most important + + align:start position:0% +okay it's one of the most important + + + align:start position:0% +okay it's one of the most important +equations we'll + + align:start position:0% +equations we'll + + + align:start position:0% +equations we'll +have Hamilton Bellman Jobe + + align:start position:0% +have Hamilton Bellman Jobe + + + align:start position:0% +have Hamilton Bellman Jobe +equation we can + + align:start position:0% + + + + align:start position:0% + +that right + + align:start position:0% + + + + align:start position:0% + +last so if you take that out + + align:start position:0% + + + + align:start position:0% + +B the difference between the value two + + align:start position:0% +B the difference between the value two + + + align:start position:0% +B the difference between the value two +neighboring with respect to time in this + + align:start position:0% +neighboring with respect to time in this + + + align:start position:0% +neighboring with respect to time in this +time and going to the next time that + + align:start position:0% +time and going to the next time that + + + align:start position:0% +time and going to the next time that +sort of seems like a TV error oh yeah + + align:start position:0% +sort of seems like a TV error oh yeah + + + align:start position:0% +sort of seems like a TV error oh yeah +yeah good there's absolutely that this + + align:start position:0% +yeah good there's absolutely that this + + + align:start position:0% +yeah good there's absolutely that this +is exactly the the source of the TDR and + + align:start position:0% +is exactly the the source of the TDR and + + + align:start position:0% +is exactly the the source of the TDR and +and the B yeah it's it's it's exactly + + align:start position:0% +and the B yeah it's it's it's exactly + + + align:start position:0% +and the B yeah it's it's it's exactly +the bment equation so yeah so you're + + align:start position:0% +the bment equation so yeah so you're + + + align:start position:0% +the bment equation so yeah so you're +right partial J partial T could have + + align:start position:0% +right partial J partial T could have + + + align:start position:0% +right partial J partial T could have +been outside the the Min over U + + align:start position:0% +been outside the the Min over U + + + align:start position:0% +been outside the the Min over U +um it doesn't actually have have you but + + align:start position:0% +um it doesn't actually have have you but + + + align:start position:0% +um it doesn't actually have have you but +but we're going to see all those all + + align:start position:0% +but we're going to see all those all + + + align:start position:0% +but we're going to see all those all +those connections as as we get into the + + align:start position:0% +those connections as as we get into the + + + align:start position:0% +those connections as as we get into the +algorithms but for this now is a tool um + + align:start position:0% +algorithms but for this now is a tool um + + + align:start position:0% +algorithms but for this now is a tool um +for proving analytically and deriving + + align:start position:0% +for proving analytically and deriving + + + align:start position:0% +for proving analytically and deriving +analytically some optimal controllers + + align:start position:0% + + + + align:start position:0% + +okay um we need one more + + align:start position:0% +okay um we need one more + + + align:start position:0% +okay um we need one more +um we need we need to say something + + align:start position:0% +um we need we need to say something + + + align:start position:0% +um we need we need to say something +stronger about how useful that tool + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +so there's the + + align:start position:0% + + + + align:start position:0% + +uh sufficiency theorem is what gives + + align:start position:0% +uh sufficiency theorem is what gives + + + align:start position:0% +uh sufficiency theorem is what gives +this guy teeth okay so I told you that + + align:start position:0% +this guy teeth okay so I told you that + + + align:start position:0% +this guy teeth okay so I told you that +the pontryagin's minimum principle was a + + align:start position:0% +the pontryagin's minimum principle was a + + + align:start position:0% +the pontryagin's minimum principle was a +necessary condition for optimality it + + align:start position:0% +necessary condition for optimality it + + + align:start position:0% +necessary condition for optimality it +wasn't necessarily sufficient if you + + align:start position:0% +wasn't necessarily sufficient if you + + + align:start position:0% +wasn't necessarily sufficient if you +show that the system um satisfies the + + align:start position:0% +show that the system um satisfies the + + + align:start position:0% +show that the system um satisfies the +pontryagin's minimum principle then you + + align:start position:0% +pontryagin's minimum principle then you + + + align:start position:0% +pontryagin's minimum principle then you +you you're close but you actually also + + align:start position:0% +you you're close but you actually also + + + align:start position:0% +you you're close but you actually also +have to say it uniquely solves that it's + + align:start position:0% +have to say it uniquely solves that it's + + + align:start position:0% +have to say it uniquely solves that it's +the only solution to that solves the + + align:start position:0% +the only solution to that solves the + + + align:start position:0% +the only solution to that solves the +Pagan's minimum principle there's extra + + align:start position:0% +Pagan's minimum principle there's extra + + + align:start position:0% +Pagan's minimum principle there's extra +work + + align:start position:0% +work + + + align:start position:0% +work +needed the theorem we're putting up here + + align:start position:0% +needed the theorem we're putting up here + + + align:start position:0% +needed the theorem we're putting up here +is saying is going to say that if if + + align:start position:0% +is saying is going to say that if if + + + align:start position:0% +is saying is going to say that if if +this equation is satisfied then that's + + align:start position:0% +this equation is satisfied then that's + + + align:start position:0% +this equation is satisfied then that's +sufficient to guarantee that this the + + align:start position:0% +sufficient to guarantee that this the + + + align:start position:0% +sufficient to guarantee that this the +the optimal the policy is + + align:start position:0% + + + + align:start position:0% + +optimal okay so + + align:start position:0% + + + + align:start position:0% + +um given a policy pi x of t and a cost + + align:start position:0% +um given a policy pi x of t and a cost + + + align:start position:0% +um given a policy pi x of t and a cost +too + + align:start position:0% + + + + align:start position:0% + +function J pi x of + + align:start position:0% + + + + align:start position:0% + +t + + align:start position:0% + + + + align:start position:0% + +if Pi is the argument of this if Pi is + + align:start position:0% +if Pi is the argument of this if Pi is + + + align:start position:0% +if Pi is the argument of this if Pi is +the policy which minimizes + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +for all X and all + + align:start position:0% + + + + align:start position:0% + +T and that condition is + + align:start position:0% + + + + align:start position:0% + +met + + align:start position:0% + + + + align:start position:0% + +he + + align:start position:0% + + + + align:start position:0% + +then we can that's sufficient to to to + + align:start position:0% +then we can that's sufficient to to to + + + align:start position:0% +then we can that's sufficient to to to +give + + align:start position:0% +give + + + align:start position:0% +give +that J pi x of T + + align:start position:0% +that J pi x of T + + + align:start position:0% +that J pi x of T +equals J Pi of X of + + align:start position:0% +equals J Pi of X of + + + align:start position:0% +equals J Pi of X of +T and pi x of + + align:start position:0% +T and pi x of + + + align:start position:0% +T and pi x of +T Pi + + align:start position:0% +T Pi + + + align:start position:0% +T Pi +star X of + + align:start position:0% + + + + align:start position:0% + +t + + align:start position:0% + + + + align:start position:0% + +okay the proof of that I'm not even + + align:start position:0% +okay the proof of that I'm not even + + + align:start position:0% +okay the proof of that I'm not even +going to try it's uh it's it's it's sort + + align:start position:0% +going to try it's uh it's it's it's sort + + + align:start position:0% +going to try it's uh it's it's it's sort +of tedious it's in berus if you like + + align:start position:0% +of tedious it's in berus if you like + + + align:start position:0% +of tedious it's in berus if you like +berkus's book but we're going to use + + align:start position:0% +berkus's book but we're going to use + + + align:start position:0% +berkus's book but we're going to use +this um a + + align:start position:0% +this um a + + + align:start position:0% +this um a +lot okay so if I can find some + + align:start position:0% +lot okay so if I can find some + + + align:start position:0% +lot okay so if I can find some +combination of of of J pi and Pi that Ma + + align:start position:0% +combination of of of J pi and Pi that Ma + + + align:start position:0% +combination of of of J pi and Pi that Ma +that match that condition then I found + + align:start position:0% +that match that condition then I found + + + align:start position:0% +that match that condition then I found +an optimal + + align:start position:0% + + + + align:start position:0% + +policy + + align:start position:0% +policy + + + align:start position:0% +policy +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um let's use this to solve the problem + + align:start position:0% +um let's use this to solve the problem + + + align:start position:0% +um let's use this to solve the problem +we + + align:start position:0% + + + + align:start position:0% + +wanted + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um the linear quadratic regulator in its + + align:start position:0% +um the linear quadratic regulator in its + + + align:start position:0% +um the linear quadratic regulator in its +general + + align:start position:0% + + + + align:start position:0% + +form says I've got a system X do equal + + align:start position:0% +form says I've got a system X do equal + + + align:start position:0% +form says I've got a system X do equal +ax + bu + + align:start position:0% + + + + align:start position:0% + +U and let's say I have a cost function + + align:start position:0% +U and let's say I have a cost function + + + align:start position:0% +U and let's say I have a cost function +um J + + align:start position:0% +um J + + + align:start position:0% +um J +of x x0 is H of x t same thing I've been + + align:start position:0% +of x x0 is H of x t same thing I've been + + + align:start position:0% +of x x0 is H of x t same thing I've been +writing all day here G of X U + + align:start position:0% + + + + align:start position:0% + +DT where x0 = X + + align:start position:0% +DT where x0 = X + + + align:start position:0% +DT where x0 = X +where H in general is takes the form X + + align:start position:0% +where H in general is takes the form X + + + align:start position:0% +where H in general is takes the form X +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +qfx and G takes the + + align:start position:0% +qfx and G takes the + + + align:start position:0% +qfx and G takes the +form H transpose QX + + align:start position:0% +form H transpose QX + + + align:start position:0% +form H transpose QX +plus u transpose r + + align:start position:0% + + + + align:start position:0% + +u to make + + align:start position:0% +u to make + + + align:start position:0% +u to make +things to be careful we're going to + + align:start position:0% +things to be careful we're going to + + + align:start position:0% +things to be careful we're going to +assume + + align:start position:0% +assume + + + align:start position:0% +assume +that we're going to enforce we're + + align:start position:0% +that we're going to enforce we're + + + align:start position:0% +that we're going to enforce we're +choosing the cost function we're going + + align:start position:0% +choosing the cost function we're going + + + align:start position:0% +choosing the cost function we're going +to enforce that this is positive + + align:start position:0% +to enforce that this is positive + + + align:start position:0% +to enforce that this is positive +definite making sure we don't get any + + align:start position:0% +definite making sure we don't get any + + + align:start position:0% +definite making sure we don't get any +negative cost + + align:start position:0% +negative cost + + + align:start position:0% +negative cost +here okay and + + align:start position:0% +here okay and + + + align:start position:0% +here okay and +similarly um actually it's it only has + + align:start position:0% +similarly um actually it's it only has + + + align:start position:0% +similarly um actually it's it only has +to be + + align:start position:0% +to be + + + align:start position:0% +to be +semi-definite uh Q transpose equals Q + + align:start position:0% +semi-definite uh Q transpose equals Q + + + align:start position:0% +semi-definite uh Q transpose equals Q +greater than equal to zero and R + + align:start position:0% +greater than equal to zero and R + + + align:start position:0% +greater than equal to zero and R +transpose equals r that one does have to + + align:start position:0% +transpose equals r that one does have to + + + align:start position:0% +transpose equals r that one does have to +be positive + + align:start position:0% + + + + align:start position:0% + +definite okay here's a pretty General + + align:start position:0% +definite okay here's a pretty General + + + align:start position:0% +definite okay here's a pretty General +um the linear dynamical system quadratic + + align:start position:0% +um the linear dynamical system quadratic + + + align:start position:0% +um the linear dynamical system quadratic +regulator cost + + align:start position:0% +regulator cost + + + align:start position:0% +regulator cost +to satisfy the + + align:start position:0% +to satisfy the + + + align:start position:0% +to satisfy the +hbj we simply have to have + + align:start position:0% +hbj we simply have to have + + + align:start position:0% +hbj we simply have to have +that this condition met + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +so 0 = Min over u x transpose + + align:start position:0% +so 0 = Min over u x transpose + + + align:start position:0% +so 0 = Min over u x transpose +QX plus u transpose + + align:start position:0% +QX plus u transpose + + + align:start position:0% +QX plus u transpose +Ru plus partial J partial + + align:start position:0% +Ru plus partial J partial + + + align:start position:0% +Ru plus partial J partial +X + + align:start position:0% +X + + + align:start position:0% +X +startimes ax plus bu + + align:start position:0% + + + + align:start position:0% + +U plus partial J star + + align:start position:0% +U plus partial J star + + + align:start position:0% +U plus partial J star +partial + + align:start position:0% +partial + + + align:start position:0% +partial +T that had better equal zero so I need + + align:start position:0% +T that had better equal zero so I need + + + align:start position:0% +T that had better equal zero so I need +to find + + align:start position:0% +to find + + + align:start position:0% +to find +that cost to go function which makes + + align:start position:0% +that cost to go function which makes + + + align:start position:0% +that cost to go function which makes +this thing + + align:start position:0% +this thing + + + align:start position:0% +this thing +zero + + align:start position:0% + + + + align:start position:0% + +okay turns out the um the solution to + + align:start position:0% +okay turns out the um the solution to + + + align:start position:0% +okay turns out the um the solution to +these things we can just guess a form + + align:start position:0% +these things we can just guess a form + + + align:start position:0% +these things we can just guess a form +for + + align:start position:0% +for + + + align:start position:0% +for +J okay let's guess the J + + align:start position:0% +J okay let's guess the J + + + align:start position:0% +J okay let's guess the J +star X of T is also + + align:start position:0% + + + + align:start position:0% + +quadratic again with a posit it's going + + align:start position:0% +quadratic again with a posit it's going + + + align:start position:0% +quadratic again with a posit it's going +to have to be + + align:start position:0% + + + + align:start position:0% + +positive could + + align:start position:0% + + + + align:start position:0% + +be + + align:start position:0% + + + + align:start position:0% + +in that case partial J partial + + align:start position:0% + + + + align:start position:0% + +X is 2x + + align:start position:0% +X is 2x + + + align:start position:0% +X is 2x +transpose s of + + align:start position:0% + + + + align:start position:0% + +T partial J partial + + align:start position:0% +T partial J partial + + + align:start position:0% +T partial J partial +T is X transpose s do of + + align:start position:0% +T is X transpose s do of + + + align:start position:0% +T is X transpose s do of +t + + align:start position:0% + + + + align:start position:0% + +x + + align:start position:0% + + + + align:start position:0% + +okay let's pop this guy + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +in + + align:start position:0% + + + + align:start position:0% + +I don't want to just crank through here + + align:start position:0% +I don't want to just crank through here + + + align:start position:0% +I don't want to just crank through here +so does it make sense at all that the + + align:start position:0% +so does it make sense at all that the + + + align:start position:0% +so does it make sense at all that the +the J of XT would be a quadratic form + + align:start position:0% +the J of XT would be a quadratic form + + + align:start position:0% +the J of XT would be a quadratic form +like that why is that a reasonable + + align:start position:0% + + + + align:start position:0% + +guess yeah the final time it's form to + + align:start position:0% +guess yeah the final time it's form to + + + align:start position:0% +guess yeah the final time it's form to +match the perfect okay so in the final + + align:start position:0% +match the perfect okay so in the final + + + align:start position:0% +match the perfect okay so in the final +time that that's a reason guest because + + align:start position:0% +time that that's a reason guest because + + + align:start position:0% +time that that's a reason guest because +it started like + + align:start position:0% + + + + align:start position:0% + +this yeah it turns out I mean we're + + align:start position:0% +this yeah it turns out I mean we're + + + align:start position:0% +this yeah it turns out I mean we're +going to we're actually going to see it + + align:start position:0% +going to we're actually going to see it + + + align:start position:0% +going to we're actually going to see it +by verification but for the linear + + align:start position:0% +by verification but for the linear + + + align:start position:0% +by verification but for the linear +system when I pump the uh the cost + + align:start position:0% +system when I pump the uh the cost + + + align:start position:0% +system when I pump the uh the cost +backwards in time this quadratic cost + + align:start position:0% +backwards in time this quadratic cost + + + align:start position:0% +backwards in time this quadratic cost +it's going to have to stay + + align:start position:0% +it's going to have to stay + + + align:start position:0% +it's going to have to stay +quadratic + + align:start position:0% + + + + align:start position:0% + +okay okay so I've got 0 = Min over U + + align:start position:0% +okay okay so I've got 0 = Min over U + + + align:start position:0% +okay okay so I've got 0 = Min over U +um X transpose QX plus u transpose r + + align:start position:0% +um X transpose QX plus u transpose r + + + align:start position:0% +um X transpose QX plus u transpose r +u + + align:start position:0% +u + + + align:start position:0% +u +plus 2 x transpose s of T bless + + align:start position:0% +plus 2 x transpose s of T bless + + + align:start position:0% +plus 2 x transpose s of T bless +you um + + align:start position:0% +you um + + + align:start position:0% +you um +times ax + bu + + align:start position:0% +times ax + bu + + + align:start position:0% +times ax + bu +U plus X transpose s t + + align:start position:0% + + + + align:start position:0% + +x I need that whole thing to work out to + + align:start position:0% +x I need that whole thing to work out to + + + align:start position:0% +x I need that whole thing to work out to +be + + align:start position:0% +be + + + align:start position:0% +be +zero okay for the minim for the + + align:start position:0% +zero okay for the minim for the + + + align:start position:0% +zero okay for the minim for the +minimizing U so let's figure out what + + align:start position:0% +minimizing U so let's figure out what + + + align:start position:0% +minimizing U so let's figure out what +the minimizing U is + + align:start position:0% +the minimizing U is + + + align:start position:0% +the minimizing U is +now is it okay if I just sort of Shand + + align:start position:0% +now is it okay if I just sort of Shand + + + align:start position:0% +now is it okay if I just sort of Shand +I'll say the the gradient of that whole + + align:start position:0% +I'll say the the gradient of that whole + + + align:start position:0% +I'll say the the gradient of that whole +thing in square brackets with respect to + + align:start position:0% +thing in square brackets with respect to + + + align:start position:0% +thing in square brackets with respect to +U here okay is going to be what two R U + + align:start position:0% +U here okay is going to be what two R U + + + align:start position:0% +U here okay is going to be what two R U +or U transpose R I + + align:start position:0% + + + + align:start position:0% + +guess I try to be careful that this this + + align:start position:0% +guess I try to be careful that this this + + + align:start position:0% +guess I try to be careful that this this +whole thing is a scalar right we're + + align:start position:0% +whole thing is a scalar right we're + + + align:start position:0% +whole thing is a scalar right we're +always talking about scalar costs I've + + align:start position:0% +always talking about scalar costs I've + + + align:start position:0% +always talking about scalar costs I've +got vectors and matricies going around + + align:start position:0% +got vectors and matricies going around + + + align:start position:0% +got vectors and matricies going around +but the whole thing has to collapse to + + align:start position:0% +but the whole thing has to collapse to + + + align:start position:0% +but the whole thing has to collapse to +be a scalar right the gradient of a + + align:start position:0% +be a scalar right the gradient of a + + + align:start position:0% +be a scalar right the gradient of a +scaler with respect to a vector I want + + align:start position:0% +scaler with respect to a vector I want + + + align:start position:0% +scaler with respect to a vector I want +it to always be a row Vector the + + align:start position:0% +it to always be a row Vector the + + + align:start position:0% +it to always be a row Vector the +gradient of a of a vector with the + + align:start position:0% +gradient of a of a vector with the + + + align:start position:0% +gradient of a of a vector with the +respect to Vector is going to be a + + align:start position:0% +respect to Vector is going to be a + + + align:start position:0% +respect to Vector is going to be a +matrix okay so try to be careful about + + align:start position:0% +matrix okay so try to be careful about + + + align:start position:0% +matrix okay so try to be careful about +making that gradient better be row + + align:start position:0% +making that gradient better be row + + + align:start position:0% +making that gradient better be row +Vector + + align:start position:0% +Vector + + + align:start position:0% +Vector +um + + align:start position:0% +um + + + align:start position:0% +um +Plus what's left here 2x transpose + + align:start position:0% +Plus what's left here 2x transpose + + + align:start position:0% +Plus what's left here 2x transpose +s that guy there + + align:start position:0% + + + + align:start position:0% + +right but I I have to take the transpose + + align:start position:0% +right but I I have to take the transpose + + + align:start position:0% +right but I I have to take the transpose +of that so it's + + align:start position:0% +of that so it's + + + align:start position:0% +of that so it's +two um B + + align:start position:0% +two um B + + + align:start position:0% +two um B +transpose s of T the St transpose is is + + align:start position:0% +transpose s of T the St transpose is is + + + align:start position:0% +transpose s of T the St transpose is is +not x no I I screwed up sorry it's still + + align:start position:0% +not x no I I screwed up sorry it's still + + + align:start position:0% +not x no I I screwed up sorry it's still +X transpose I'm trying to X transpose s + + align:start position:0% +X transpose I'm trying to X transpose s + + + align:start position:0% +X transpose I'm trying to X transpose s +of t + + align:start position:0% +of t + + + align:start position:0% +of t +b okay that thing has to equal + + align:start position:0% + + + + align:start position:0% + +zero and that's where I get my transpose + + align:start position:0% +zero and that's where I get my transpose + + + align:start position:0% +zero and that's where I get my transpose +back so U star the U that makes this + + align:start position:0% +back so U star the U that makes this + + + align:start position:0% +back so U star the U that makes this +gradient zero is going to be those twos + + align:start position:0% +gradient zero is going to be those twos + + + align:start position:0% +gradient zero is going to be those twos +cancel it's going to be negative R + + align:start position:0% +cancel it's going to be negative R + + + align:start position:0% +cancel it's going to be negative R +inverse + + align:start position:0% +inverse + + + align:start position:0% +inverse +B + + align:start position:0% +B + + + align:start position:0% +B +transpose s + + align:start position:0% +transpose s + + + align:start position:0% +transpose s +transpose + + align:start position:0% + + + + align:start position:0% + +X + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +which it's important to realize that was + + align:start position:0% +which it's important to realize that was + + + align:start position:0% +which it's important to realize that was +actually um it's equivalent to writing + + align:start position:0% +actually um it's equivalent to writing + + + align:start position:0% +actually um it's equivalent to writing +negative half R inverse B transpose + + align:start position:0% +negative half R inverse B transpose + + + align:start position:0% +negative half R inverse B transpose +partial J partial X + + align:start position:0% + + + + align:start position:0% + +transpose okay so what does this + + align:start position:0% +transpose okay so what does this + + + align:start position:0% +transpose okay so what does this +mean there's + + align:start position:0% +mean there's + + + align:start position:0% +mean there's +so I've got some quadratic approximation + + align:start position:0% +so I've got some quadratic approximation + + + align:start position:0% +so I've got some quadratic approximation +of my value function okay it's zero at + + align:start position:0% +of my value function okay it's zero at + + + align:start position:0% +of my value function okay it's zero at +the or origin always and forever if I'm + + align:start position:0% +the or origin always and forever if I'm + + + align:start position:0% +the or origin always and forever if I'm +at the origin I'm going to stay at the + + align:start position:0% +at the origin I'm going to stay at the + + + align:start position:0% +at the origin I'm going to stay at the +origin my cost to go zero right the + + align:start position:0% +origin my cost to go zero right the + + + align:start position:0% +origin my cost to go zero right the +exact shape of the quadratic bow changes + + align:start position:0% +exact shape of the quadratic bow changes + + + align:start position:0% +exact shape of the quadratic bow changes +over + + align:start position:0% +over + + + align:start position:0% +over +time the best thing to do is to go down + + align:start position:0% +time the best thing to do is to go down + + + align:start position:0% +time the best thing to do is to go down +so negative of partial J partial X is + + align:start position:0% +so negative of partial J partial X is + + + align:start position:0% +so negative of partial J partial X is +trying to go down the cost to go + + align:start position:0% +trying to go down the cost to go + + + align:start position:0% +trying to go down the cost to go +function right I want to go down the + + align:start position:0% +function right I want to go down the + + + align:start position:0% +function right I want to go down the +cost to go function as fast as I + + align:start position:0% +cost to go function as fast as I + + + align:start position:0% +cost to go function as fast as I +can right but I'm going to wait I'm + + align:start position:0% +can right but I'm going to wait I'm + + + align:start position:0% +can right but I'm going to wait I'm +going to I'm going to change possibly + + align:start position:0% +going to I'm going to change possibly + + + align:start position:0% +going to I'm going to change possibly +the act Direction rather than going + + align:start position:0% +the act Direction rather than going + + + align:start position:0% +the act Direction rather than going +straight down the cost to go function in + + align:start position:0% +straight down the cost to go function in + + + align:start position:0% +straight down the cost to go function in +X I might Orient myself a little bit + + align:start position:0% +X I might Orient myself a little bit + + + align:start position:0% +X I might Orient myself a little bit +depending on the weightings I've put on + + align:start position:0% +depending on the weightings I've put on + + + align:start position:0% +depending on the weightings I've put on +the different the cost I put on the + + align:start position:0% +the different the cost I put on the + + + align:start position:0% +the different the cost I put on the +different + + align:start position:0% +different + + + align:start position:0% +different +U's okay so I'm going to rotate that + + align:start position:0% +U's okay so I'm going to rotate that + + + align:start position:0% +U's okay so I'm going to rotate that +Vector a little + + align:start position:0% +Vector a little + + + align:start position:0% +Vector a little +bit Bas this is what I can do and this + + align:start position:0% +bit Bas this is what I can do and this + + + align:start position:0% +bit Bas this is what I can do and this +is what the the waiting I've done okay + + align:start position:0% +is what the the waiting I've done okay + + + align:start position:0% +is what the the waiting I've done okay +so the best thing to do is to go down + + align:start position:0% +so the best thing to do is to go down + + + align:start position:0% +so the best thing to do is to go down +your cost to go function get to the + + align:start position:0% +your cost to go function get to the + + + align:start position:0% +your cost to go function get to the +point where my cost to go is going to be + + align:start position:0% +point where my cost to go is going to be + + + align:start position:0% +point where my cost to go is going to be +as small as + + align:start position:0% +as small as + + + align:start position:0% +as small as +possible filtered by the the direction I + + align:start position:0% +possible filtered by the the direction I + + + align:start position:0% +possible filtered by the the direction I +can actually go and Twisted by the the + + align:start position:0% +can actually go and Twisted by the the + + + align:start position:0% +can actually go and Twisted by the the +way I've penalized + + align:start position:0% +way I've penalized + + + align:start position:0% +way I've penalized +actions + + align:start position:0% + + + + align:start position:0% + +okay and it's sort of amazing I think + + align:start position:0% +okay and it's sort of amazing I think + + + align:start position:0% +okay and it's sort of amazing I think +that the whole thing works out to be + + align:start position:0% +that the whole thing works out to be + + + align:start position:0% +that the whole thing works out to be +um just some linear feedback law + + align:start position:0% +um just some linear feedback law + + + align:start position:0% +um just some linear feedback law +negative KX yet another + + align:start position:0% +negative KX yet another + + + align:start position:0% +negative KX yet another +reason albor is to use that + + align:start position:0% + + + + align:start position:0% + +form + + align:start position:0% + + + + align:start position:0% + +okay uh sorry I should be a little + + align:start position:0% +okay uh sorry I should be a little + + + align:start position:0% +okay uh sorry I should be a little +careful this is It's it depends on time + + align:start position:0% +careful this is It's it depends on time + + + align:start position:0% +careful this is It's it depends on time +right so it's K of + + align:start position:0% + + + + align:start position:0% + +TX why should it depend on + + align:start position:0% +TX why should it depend on + + + align:start position:0% +TX why should it depend on +[Music] + + align:start position:0% + + + + align:start position:0% + +time this is a what's that switch cuz we + + align:start position:0% +time this is a what's that switch cuz we + + + align:start position:0% +time this is a what's that switch cuz we +switch what uh the + + align:start position:0% +switch what uh the + + + align:start position:0% +switch what uh the +actuation there's no hard switch in the + + align:start position:0% +actuation there's no hard switch in the + + + align:start position:0% +actuation there's no hard switch in the +actuation here this is saying I'm going + + align:start position:0% +actuation here this is saying I'm going + + + align:start position:0% +actuation here this is saying I'm going +to smoothly go down a value + + align:start position:0% +to smoothly go down a value + + + align:start position:0% +to smoothly go down a value +function right this one isn't the bang + + align:start position:0% +function right this one isn't the bang + + + align:start position:0% +function right this one isn't the bang +bang controller this is turns out to be + + align:start position:0% +bang controller this is turns out to be + + + align:start position:0% +bang controller this is turns out to be +a smooth Descent of some cost too + + align:start position:0% + + + + align:start position:0% + +function + + align:start position:0% + + + + align:start position:0% + +yeah I mean s of T is time dependent + + align:start position:0% +yeah I mean s of T is time dependent + + + align:start position:0% +yeah I mean s of T is time dependent +itself + + align:start position:0% +itself + + + align:start position:0% +itself +yeah so intuitively why why should I + + align:start position:0% +yeah so intuitively why why should I + + + align:start position:0% +yeah so intuitively why why should I +take a different uh linear control + + align:start position:0% +take a different uh linear control + + + align:start position:0% +take a different uh linear control +action if I'm at time one versus time + + align:start position:0% +action if I'm at time one versus time + + + align:start position:0% +action if I'm at time one versus time +too because you're you're time limited + + align:start position:0% +too because you're you're time limited + + + align:start position:0% +too because you're you're time limited +so if you're very close to the final + + align:start position:0% +so if you're very close to the final + + + align:start position:0% +so if you're very close to the final +time you want to lots of + + align:start position:0% +time you want to lots of + + + align:start position:0% +time you want to lots of +control because you don't have much time + + align:start position:0% +control because you don't have much time + + + align:start position:0% +control because you don't have much time +to awesome yeah this is a quirk of + + align:start position:0% +to awesome yeah this is a quirk of + + + align:start position:0% +to awesome yeah this is a quirk of +having a finite Horizon cost + + align:start position:0% +having a finite Horizon cost + + + align:start position:0% +having a finite Horizon cost +function okay in the infinite Horizon + + align:start position:0% +function okay in the infinite Horizon + + + align:start position:0% +function okay in the infinite Horizon +case it turns out it's you're going to + + align:start position:0% +case it turns out it's you're going to + + + align:start position:0% +case it turns out it's you're going to +just get a uh U equal negative K ofx + + align:start position:0% +just get a uh U equal negative K ofx + + + align:start position:0% +just get a uh U equal negative K ofx +where K is in variant of time but in the + + align:start position:0% +where K is in variant of time but in the + + + align:start position:0% +where K is in variant of time but in the +time finite Horizon + + align:start position:0% +time finite Horizon + + + align:start position:0% +time finite Horizon +problem there's this Quirk which which + + align:start position:0% +problem there's this Quirk which which + + + align:start position:0% +problem there's this Quirk which which +is the time ends at some point and I + + align:start position:0% +is the time ends at some point and I + + + align:start position:0% +is the time ends at some point and I +have to deal with it right like the bank + + align:start position:0% +have to deal with it right like the bank + + + align:start position:0% +have to deal with it right like the bank +closes at 5 right if I'm here and the B + + align:start position:0% +closes at 5 right if I'm here and the B + + + align:start position:0% +closes at 5 right if I'm here and the B +and it's 450 and the bank closes at 5 + + align:start position:0% +and it's 450 and the bank closes at 5 + + + align:start position:0% +and it's 450 and the bank closes at 5 +I'm going to I better get over there + + align:start position:0% +I'm going to I better get over there + + + align:start position:0% +I'm going to I better get over there +faster than if it was 430 and the bank + + align:start position:0% +faster than if it was 430 and the bank + + + align:start position:0% +faster than if it was 430 and the bank +closes a 5 + + align:start position:0% +closes a 5 + + + align:start position:0% +closes a 5 +right in my mind actually there's a lot + + align:start position:0% +right in my mind actually there's a lot + + + align:start position:0% +right in my mind actually there's a lot +of problems that are you know Bank + + align:start position:0% +of problems that are you know Bank + + + align:start position:0% +of problems that are you know Bank +closing is a weird one but um there are + + align:start position:0% +closing is a weird one but um there are + + + align:start position:0% +closing is a weird one but um there are +a lot of problems that are naturally + + align:start position:0% +a lot of problems that are naturally + + + align:start position:0% +a lot of problems that are naturally +formulated as finite Horizon problems + + align:start position:0% +formulated as finite Horizon problems + + + align:start position:0% +formulated as finite Horizon problems +things maybe a a pi and place the + + align:start position:0% +things maybe a a pi and place the + + + align:start position:0% +things maybe a a pi and place the +minimum time problem was a finite + + align:start position:0% +minimum time problem was a finite + + + align:start position:0% +minimum time problem was a finite +Horizon pick and place there are a lot + + align:start position:0% +Horizon pick and place there are a lot + + + align:start position:0% +Horizon pick and place there are a lot +of problems which are naturally + + align:start position:0% +of problems which are naturally + + + align:start position:0% +of problems which are naturally +formulated as infinite Horizon I just + + align:start position:0% +formulated as infinite Horizon I just + + + align:start position:0% +formulated as infinite Horizon I just +want to walk as well as I possibly can + + align:start position:0% +want to walk as well as I possibly can + + + align:start position:0% +want to walk as well as I possibly can +for a very long time I don't need to get + + align:start position:0% +for a very long time I don't need to get + + + align:start position:0% +for a very long time I don't need to get +to some place at a certain time okay um + + align:start position:0% +to some place at a certain time okay um + + + align:start position:0% +to some place at a certain time okay um +but in many ways the finite Horizon time + + align:start position:0% +but in many ways the finite Horizon time + + + align:start position:0% +but in many ways the finite Horizon time +ones are the weird ones because you + + align:start position:0% +ones are the weird ones because you + + + align:start position:0% +ones are the weird ones because you +always have to worry about the End of + + align:start position:0% +always have to worry about the End of + + + align:start position:0% +always have to worry about the End of +Time approaching + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +okay + + align:start position:0% +okay + + + align:start position:0% +okay +how do we get St + + align:start position:0% +how do we get St + + + align:start position:0% +how do we get St +okay well it's the thing that makes this + + align:start position:0% +okay well it's the thing that makes this + + + align:start position:0% +okay well it's the thing that makes this +equation zero + + align:start position:0% + + + + align:start position:0% + +right so what is that + + align:start position:0% + + + + align:start position:0% + +thing so I figured out what the + + align:start position:0% +thing so I figured out what the + + + align:start position:0% +thing so I figured out what the +minimizing U + + align:start position:0% +minimizing U + + + align:start position:0% +minimizing U +is + + align:start position:0% +is + + + align:start position:0% +is +I can insert that back in so I get now 0 + + align:start position:0% + + + + align:start position:0% + +equals Q Plus um X transpose I'm going + + align:start position:0% +equals Q Plus um X transpose I'm going + + + align:start position:0% +equals Q Plus um X transpose I'm going +to insert u + + align:start position:0% +to insert u + + + align:start position:0% +to insert u +in K or I'll do the whole thing actually + + align:start position:0% +in K or I'll do the whole thing actually + + + align:start position:0% +in K or I'll do the whole thing actually +um s of + + align:start position:0% +um s of + + + align:start position:0% +um s of +t + + align:start position:0% +t + + + align:start position:0% +t +b r + + align:start position:0% +b r + + + align:start position:0% +b r +inverse time R time R inverse so I'm + + align:start position:0% +inverse time R time R inverse so I'm + + + align:start position:0% +inverse time R time R inverse so I'm +going to go ahead and cancel those + + align:start position:0% +going to go ahead and cancel those + + + align:start position:0% +going to go ahead and cancel those +out B + + align:start position:0% +out B + + + align:start position:0% +out B +transpose s of t + + align:start position:0% +transpose s of t + + + align:start position:0% +transpose s of t +x + + align:start position:0% +x + + + align:start position:0% +x +right and the the negative signs because + + align:start position:0% +right and the the negative signs because + + + align:start position:0% +right and the the negative signs because +it was there's two U's there the + + align:start position:0% +it was there's two U's there the + + + align:start position:0% +it was there's two U's there the +negative sign + + align:start position:0% +negative sign + + + align:start position:0% +negative sign +didn't get me and then plus 2 x + + align:start position:0% +didn't get me and then plus 2 x + + + align:start position:0% +didn't get me and then plus 2 x +transpose s of + + align:start position:0% +transpose s of + + + align:start position:0% +transpose s of +T + + align:start position:0% +T + + + align:start position:0% +T +ax plus so + + align:start position:0% +ax plus so + + + align:start position:0% +ax plus so +minus B R + + align:start position:0% +minus B R + + + align:start position:0% +minus B R +inverse um B transpose s of + + align:start position:0% +inverse um B transpose s of + + + align:start position:0% +inverse um B transpose s of +t + + align:start position:0% + + + + align:start position:0% + +x plus X transpose s do of + + align:start position:0% + + + + align:start position:0% + +X + + align:start position:0% + + + + align:start position:0% + +okay turns out that + + align:start position:0% +okay turns out that + + + align:start position:0% +okay turns out that +this term here should be the same as + + align:start position:0% +this term here should be the same as + + + align:start position:0% +this term here should be the same as +that term there modulo of factor two if + + align:start position:0% +that term there modulo of factor two if + + + align:start position:0% +that term there modulo of factor two if +you look it's s b r inverse B transpose + + align:start position:0% +you look it's s b r inverse B transpose + + + align:start position:0% +you look it's s b r inverse B transpose +s okay so this one + + align:start position:0% +s okay so this one + + + align:start position:0% +s okay so this one +actually I + + align:start position:0% +actually I + + + align:start position:0% +actually I +can just turn that into a + + align:start position:0% +can just turn that into a + + + align:start position:0% +can just turn that into a +minus + + align:start position:0% + + + + align:start position:0% + +okay and it turns out that everything + + align:start position:0% +okay and it turns out that everything + + + align:start position:0% +okay and it turns out that everything +has this x transpose Matrix X + + align:start position:0% +has this x transpose Matrix X + + + align:start position:0% +has this x transpose Matrix X +form okay so I can actually in order for + + align:start position:0% +form okay so I can actually in order for + + + align:start position:0% +form okay so I can actually in order for +this thing to to be true for all X it + + align:start position:0% +this thing to to be true for all X it + + + align:start position:0% +this thing to to be true for all X it +must be that the Matrix inside had + + align:start position:0% +must be that the Matrix inside had + + + align:start position:0% +must be that the Matrix inside had +better be zero so it turns out to be 0 + + align:start position:0% +better be zero so it turns out to be 0 + + + align:start position:0% +better be zero so it turns out to be 0 +equals + + align:start position:0% +equals + + + align:start position:0% +equals +uh Q minus + + align:start position:0% +uh Q minus + + + align:start position:0% +uh Q minus +St b r inverse B + + align:start position:0% +St b r inverse B + + + align:start position:0% +St b r inverse B +transpose + + align:start position:0% + + + + align:start position:0% + +St + + + align:start position:0% +St + + + + align:start position:0% +St + + + align:start position:0% + + + align:start position:0% +St + + align:start position:0% +St + + + align:start position:0% +St +a plus s do of T had better be equal to + + align:start position:0% +a plus s do of T had better be equal to + + + align:start position:0% +a plus s do of T had better be equal to +zero + + align:start position:0% +zero + + + align:start position:0% +zero +okay now I made some assumptions to get + + align:start position:0% +okay now I made some assumptions to get + + + align:start position:0% +okay now I made some assumptions to get +here remember what assumptions I made + + align:start position:0% +here remember what assumptions I made + + + align:start position:0% +here remember what assumptions I made +the big one is that I guessed that form + + align:start position:0% +the big one is that I guessed that form + + + align:start position:0% +the big one is that I guessed that form +of the value function okay and one of + + align:start position:0% +of the value function okay and one of + + + align:start position:0% +of the value function okay and one of +the things I guessed about it was that + + align:start position:0% +the things I guessed about it was that + + + align:start position:0% +the things I guessed about it was that +it was + + align:start position:0% +it was + + + align:start position:0% +it was +symmetric so let's see if we're looking + + align:start position:0% +symmetric so let's see if we're looking + + + align:start position:0% +symmetric so let's see if we're looking +symmetric so Q we already said was + + align:start position:0% +symmetric so Q we already said was + + + align:start position:0% +symmetric so Q we already said was +symmetric that's all all good that guy + + align:start position:0% +symmetric that's all all good that guy + + + align:start position:0% +symmetric that's all all good that guy +is nice and symmetric that's all + + align:start position:0% +is nice and symmetric that's all + + + align:start position:0% +is nice and symmetric that's all +good so this is the one we have to worry + + align:start position:0% +good so this is the one we have to worry + + + align:start position:0% +good so this is the one we have to worry +about is that guy + + align:start position:0% + + + + align:start position:0% + +symmetric it's actually not symmetric + + align:start position:0% +symmetric it's actually not symmetric + + + align:start position:0% +symmetric it's actually not symmetric +like that but you can I can equivalently + + align:start position:0% +like that but you can I can equivalently + + + align:start position:0% +like that but you can I can equivalently +write it as + + align:start position:0% +write it as + + + align:start position:0% +write it as +um as St a plus a transpose St since s + + align:start position:0% +um as St a plus a transpose St since s + + + align:start position:0% +um as St a plus a transpose St since s +is symmetric + + align:start position:0% + + + + align:start position:0% + +and that guy is + + align:start position:0% + + + + align:start position:0% + +symmetric I said a very strange thing I + + align:start position:0% +symmetric I said a very strange thing I + + + align:start position:0% +symmetric I said a very strange thing I +just said that the matrices are um this + + align:start position:0% +just said that the matrices are um this + + + align:start position:0% +just said that the matrices are um this +one is not symmetric I can write the + + align:start position:0% +one is not symmetric I can write the + + + align:start position:0% +one is not symmetric I can write the +same thing and it's it's this so um what + + align:start position:0% +same thing and it's it's this so um what + + + align:start position:0% +same thing and it's it's this so um what +I mean to say is that um these are these + + align:start position:0% +I mean to say is that um these are these + + + align:start position:0% +I mean to say is that um these are these +are equivalent + + align:start position:0% + + + + align:start position:0% + +for all X + + align:start position:0% + + + + align:start position:0% + +okay because + + align:start position:0% + + + + align:start position:0% + +this has got to equal + + align:start position:0% +this has got to equal + + + align:start position:0% +this has got to equal +this + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so good okay so this equation which I'm + + align:start position:0% +so good okay so this equation which I'm + + + align:start position:0% +so good okay so this equation which I'm +going to write more time since it's an + + align:start position:0% +going to write more time since it's an + + + align:start position:0% +going to write more time since it's an +equation that has a name associated with + + align:start position:0% +equation that has a name associated with + + + align:start position:0% +equation that has a name associated with +someone famous deserves a box around it + + align:start position:0% +someone famous deserves a box around it + + + align:start position:0% +someone famous deserves a box around it +I guess right so this is U the rotti + + align:start position:0% +I guess right so this is U the rotti + + + align:start position:0% +I guess right so this is U the rotti +equation I'm going to move the S over to + + align:start position:0% +equation I'm going to move the S over to + + + align:start position:0% +equation I'm going to move the S over to +this side um it's a ricot + + align:start position:0% + + + + align:start position:0% + +equation + + align:start position:0% + + + + align:start position:0% + +okay and I also have that final + + align:start position:0% +okay and I also have that final + + + align:start position:0% +okay and I also have that final +condition that you rightly pointed out + + align:start position:0% +condition that you rightly pointed out + + + align:start position:0% +condition that you rightly pointed out +where s of capital T had better equal + + align:start position:0% + + + + align:start position:0% + +qf so direct application of the Hamilton + + align:start position:0% +qf so direct application of the Hamilton + + + align:start position:0% +qf so direct application of the Hamilton +Bellman jacobe equation I was able + + align:start position:0% +Bellman jacobe equation I was able + + + align:start position:0% +Bellman jacobe equation I was able +to um derive + + align:start position:0% +to um derive + + + align:start position:0% +to um derive +this uh this rotti equation which gives + + align:start position:0% +this uh this rotti equation which gives + + + align:start position:0% +this uh this rotti equation which gives +me a solution for the value function + + align:start position:0% +me a solution for the value function + + + align:start position:0% +me a solution for the value function +right it gives me a final condition on + + align:start position:0% +right it gives me a final condition on + + + align:start position:0% +right it gives me a final condition on +um on S and then I'm the the governing + + align:start position:0% +um on S and then I'm the the governing + + + align:start position:0% +um on S and then I'm the the governing +equation which integrates the equation + + align:start position:0% +equation which integrates the equation + + + align:start position:0% +equation which integrates the equation +backwards from capital T to + + align:start position:0% + + + + align:start position:0% + +zero and once I have S remember we said + + align:start position:0% +zero and once I have S remember we said + + + align:start position:0% +zero and once I have S remember we said +that the U was just um negative R + + align:start position:0% +that the U was just um negative R + + + align:start position:0% +that the U was just um negative R +inverse B transpose s of t + + align:start position:0% +inverse B transpose s of t + + + align:start position:0% +inverse B transpose s of t +X so I've got everything once I have S I + + align:start position:0% +X so I've got everything once I have S I + + + align:start position:0% +X so I've got everything once I have S I +have + + align:start position:0% + + + + align:start position:0% + +everything okay so this is one of the + + align:start position:0% +everything okay so this is one of the + + + align:start position:0% +everything okay so this is one of the +absolute fundamental results in U in + + align:start position:0% +absolute fundamental results in U in + + + align:start position:0% +absolute fundamental results in U in +optimal + + align:start position:0% +optimal + + + align:start position:0% +optimal +control + + align:start position:0% +control + + + align:start position:0% +control +um it turns out that + + align:start position:0% +um it turns out that + + + align:start position:0% +um it turns out that +um if you want to know the infinite + + align:start position:0% +um if you want to know the infinite + + + align:start position:0% +um if you want to know the infinite +Horizon + + align:start position:0% +Horizon + + + align:start position:0% +Horizon +solution to the if if if you look at the + + align:start position:0% +solution to the if if if you look at the + + + align:start position:0% +solution to the if if if you look at the +solution as time goes to Infinity okay + + align:start position:0% +solution as time goes to Infinity okay + + + align:start position:0% +solution as time goes to Infinity okay +remember I wrote my my cost function + + align:start position:0% +remember I wrote my my cost function + + + align:start position:0% +remember I wrote my my cost function +initially was of the problem we're + + align:start position:0% +initially was of the problem we're + + + align:start position:0% +initially was of the problem we're +trying to solve is um an infinite + + align:start position:0% +trying to solve is um an infinite + + + align:start position:0% +trying to solve is um an infinite +integral it turns out that the infinite + + align:start position:0% +integral it turns out that the infinite + + + align:start position:0% +integral it turns out that the infinite +solution is the steady state solution of + + align:start position:0% +solution is the steady state solution of + + + align:start position:0% +solution is the steady state solution of +this + + align:start position:0% +this + + + align:start position:0% +this +equation okay so if you integrate this + + align:start position:0% +equation okay so if you integrate this + + + align:start position:0% +equation okay so if you integrate this +equation back enough it's stable it + + align:start position:0% +equation back enough it's stable it + + + align:start position:0% +equation back enough it's stable it +finds a steady state where s is Z and + + align:start position:0% +finds a steady state where s is Z and + + + align:start position:0% +finds a steady state where s is Z and +that solution when s do equals + + align:start position:0% +that solution when s do equals + + + align:start position:0% +that solution when s do equals +z the S which which um solves + + align:start position:0% + + + + align:start position:0% + +this that whole thing minus + + align:start position:0% +this that whole thing minus + + + align:start position:0% +this that whole thing minus +Q um is the infinite Horizon + + align:start position:0% + + + + align:start position:0% + +solution + + align:start position:0% + + + + align:start position:0% + +okay if you open up mat + + align:start position:0% +okay if you open up mat + + + align:start position:0% +okay if you open up mat +lab okay and you + + align:start position:0% +lab okay and you + + + align:start position:0% +lab okay and you +type + + align:start position:0% +type + + + align:start position:0% +type +lqr A B + + align:start position:0% +lqr A B + + + align:start position:0% +lqr A B +QR then it's going to Output two things + + align:start position:0% +QR then it's going to Output two things + + + align:start position:0% +QR then it's going to Output two things +it outputs K and it outputs + + align:start position:0% +it outputs K and it outputs + + + align:start position:0% +it outputs K and it outputs +s okay solving this thing is actually + + align:start position:0% +s okay solving this thing is actually + + + align:start position:0% +s okay solving this thing is actually +not trivial right so how do you how do + + align:start position:0% +not trivial right so how do you how do + + + align:start position:0% +not trivial right so how do you how do +you solve that uh for S right the hard + + align:start position:0% +you solve that uh for S right the hard + + + align:start position:0% +you solve that uh for S right the hard +one is it's got this + + align:start position:0% +one is it's got this + + + align:start position:0% +one is it's got this +s in both places but this is a this is a + + align:start position:0% +s in both places but this is a this is a + + + align:start position:0% +s in both places but this is a this is a +a leop andov equation again um it's it's + + align:start position:0% +a leop andov equation again um it's it's + + + align:start position:0% +a leop andov equation again um it's it's +so famous it comes up so pervasively + + align:start position:0% +so famous it comes up so pervasively + + + align:start position:0% +so famous it comes up so pervasively +that people have really good tools for + + align:start position:0% +that people have really good tools for + + + align:start position:0% +that people have really good tools for +solving it numerical tools for solving + + align:start position:0% +solving it numerical tools for solving + + + align:start position:0% +solving it numerical tools for solving +it so mat lab's got some nice routine in + + align:start position:0% +it so mat lab's got some nice routine in + + + align:start position:0% +it so mat lab's got some nice routine in +there to to to solve to find s okay and + + align:start position:0% +there to to to solve to find s okay and + + + align:start position:0% +there to to to solve to find s okay and +when I call lqr uh with the the Dynamics + + align:start position:0% +when I call lqr uh with the the Dynamics + + + align:start position:0% +when I call lqr uh with the the Dynamics +and the Q QR gives me exactly the the + + align:start position:0% +and the Q QR gives me exactly the the + + + align:start position:0% +and the Q QR gives me exactly the the +infinite Horizon s and infinite Horizon + + align:start position:0% +infinite Horizon s and infinite Horizon + + + align:start position:0% +infinite Horizon s and infinite Horizon +time non-time variant K right if you + + align:start position:0% +time non-time variant K right if you + + + align:start position:0% +time non-time variant K right if you +need to do a finite Horizon quadratic + + align:start position:0% +need to do a finite Horizon quadratic + + + align:start position:0% +need to do a finite Horizon quadratic +regulator then you actually need to + + align:start position:0% +regulator then you actually need to + + + align:start position:0% +regulator then you actually need to +integrate these equations + + align:start position:0% +integrate these equations + + + align:start position:0% +integrate these equations +yourself okay I hate going that long + + align:start position:0% +yourself okay I hate going that long + + + align:start position:0% +yourself okay I hate going that long +with just equations and not intuition so + + align:start position:0% +with just equations and not intuition so + + + align:start position:0% +with just equations and not intuition so +let me connect it back to the now that's + + align:start position:0% +let me connect it back to the now that's + + + align:start position:0% +let me connect it back to the now that's +that was the point of doing everything + + align:start position:0% +that was the point of doing everything + + + align:start position:0% +that was the point of doing everything +in the brick World + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +okay so we've got Q equals U we've got + + align:start position:0% +okay so we've got Q equals U we've got + + + align:start position:0% +okay so we've got Q equals U we've got +um now infinite Horizon + + align:start position:0% + + + + align:start position:0% + +JX is um infinite Horizon GX U DT where + + align:start position:0% +JX is um infinite Horizon GX U DT where + + + align:start position:0% +JX is um infinite Horizon GX U DT where +I said g X U was 1 12 Q ^2 + 12 Q do^ 2 + + align:start position:0% +I said g X U was 1 12 Q ^2 + 12 Q do^ 2 + + + align:start position:0% +I said g X U was 1 12 Q ^2 + 12 Q do^ 2 ++ 12 u^2 + + align:start position:0% ++ 12 u^2 + + + align:start position:0% ++ 12 u^2 +okay so now that's + + align:start position:0% +okay so now that's + + + align:start position:0% +okay so now that's +exactly in the lqr form 0 1 0 + + align:start position:0% +exactly in the lqr form 0 1 0 + + + align:start position:0% +exactly in the lqr form 0 1 0 +0 um B is 0 + + align:start position:0% +0 um B is 0 + + + align:start position:0% +0 um B is 0 + + align:start position:0% + + + align:start position:0% +Q + + align:start position:0% +Q + + + align:start position:0% +Q +is the identity Matrix + + align:start position:0% +is the identity Matrix + + + align:start position:0% +is the identity Matrix +and R is + + align:start position:0% + + + + align:start position:0% + +one turns out I can actually solve that + + align:start position:0% +one turns out I can actually solve that + + + align:start position:0% +one turns out I can actually solve that +one algebraically for S if you pump all + + align:start position:0% +one algebraically for S if you pump all + + + align:start position:0% +one algebraically for S if you pump all +the symbols in I won't do it because + + align:start position:0% +the symbols in I won't do it because + + + align:start position:0% +the symbols in I won't do it because +there's a lot of symbols but in a few + + align:start position:0% +there's a lot of symbols but in a few + + + align:start position:0% +there's a lot of symbols but in a few +lines of algebra you can figure out what + + align:start position:0% +lines of algebra you can figure out what + + + align:start position:0% +lines of algebra you can figure out what +s has to be okay just because so many + + align:start position:0% +s has to be okay just because so many + + + align:start position:0% +s has to be okay just because so many +terms drop out with those zeros that + + align:start position:0% +terms drop out with those zeros that + + + align:start position:0% +terms drop out with those zeros that +actually + + align:start position:0% +actually + + + align:start position:0% +actually +there's uh it's there's a three + + align:start position:0% +there's uh it's there's a three + + + align:start position:0% +there's uh it's there's a three +equations and three + + align:start position:0% +equations and three + + + align:start position:0% +equations and three +unknowns and turns out that s has to + + align:start position:0% +unknowns and turns out that s has to + + + align:start position:0% +unknowns and turns out that s has to +be square < TK two + + align:start position:0% +be square < TK two + + + align:start position:0% +be square < TK two +1 1 s > + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% +the + + + align:start position:0% +the +um U remember was negative R inverse B + + align:start position:0% + + + + align:start position:0% + +transpose B + + align:start position:0% +transpose B + + + align:start position:0% +transpose B +transpose + + align:start position:0% + + + + align:start position:0% + +SX which if I punch those in gives me um + + align:start position:0% +SX which if I punch those in gives me um + + + align:start position:0% +SX which if I punch those in gives me um +one + + align:start position:0% +one + + + align:start position:0% +one +s < TK 2 * + + align:start position:0% + + + + align:start position:0% + +X + + align:start position:0% +X + + + align:start position:0% +X +okay which gives me Clos Loop + + align:start position:0% + + + + align:start position:0% + +dynamics of X do equals um ax minus B KX + + align:start position:0% +dynamics of X do equals um ax minus B KX + + + align:start position:0% +dynamics of X do equals um ax minus B KX +is equal to 0 + + align:start position:0% +is equal to 0 + + + align:start position:0% +is equal to 0 +1 -1 < TK + + align:start position:0% +1 -1 < TK + + + align:start position:0% +1 -1 < TK +2 * + + align:start position:0% + + + + align:start position:0% + +X okay now I'm going to plot two things + + align:start position:0% + + + + align:start position:0% + +here first thing I'm going to + + align:start position:0% + + + + align:start position:0% + +plot is J + + align:start position:0% + + + + align:start position:0% + +of X + + align:start position:0% +of X + + + align:start position:0% +of X +okay J of X isun of two one 1 s of + + align:start position:0% + + + + align:start position:0% + +two a little thinking about that you'll + + align:start position:0% +two a little thinking about that you'll + + + align:start position:0% +two a little thinking about that you'll +see that it comes out to + + align:start position:0% + + + + align:start position:0% + +be an + + align:start position:0% +be an + + + align:start position:0% +be an +ellipsoid that + + align:start position:0% +ellipsoid that + + + align:start position:0% +ellipsoid that +is actually + + align:start position:0% + + + + align:start position:0% + +more + + align:start position:0% + + + + align:start position:0% + +sort of shaped like this + + align:start position:0% +sort of shaped like this + + + align:start position:0% +sort of shaped like this +okay if I draw Contours of that function + + align:start position:0% +okay if I draw Contours of that function + + + align:start position:0% +okay if I draw Contours of that function +of that X transpose + + align:start position:0% +of that X transpose + + + align:start position:0% +of that X transpose +s + + align:start position:0% + + + + align:start position:0% + +x then my cost to go is zero here and + + align:start position:0% +x then my cost to go is zero here and + + + align:start position:0% +x then my cost to go is zero here and +it's a bowl that comes up in this sort + + align:start position:0% + + + + align:start position:0% + +of a IC Bowl + + align:start position:0% + + + + align:start position:0% + +okay all right so what is the uh optimal + + align:start position:0% +okay all right so what is the uh optimal + + + align:start position:0% +okay all right so what is the uh optimal +policy going to look like given that + + align:start position:0% +policy going to look like given that + + + align:start position:0% +policy going to look like given that +that's my + + align:start position:0% + + + + align:start position:0% + +bowl right we said the best thing to do + + align:start position:0% +bowl right we said the best thing to do + + + align:start position:0% +bowl right we said the best thing to do +is to go down the steepest Ascent of the + + align:start position:0% +is to go down the steepest Ascent of the + + + align:start position:0% +is to go down the steepest Ascent of the +bowl okay I want to go down wherever I + + align:start position:0% +bowl okay I want to go down wherever I + + + align:start position:0% +bowl okay I want to go down wherever I +am I want to go down as fast as I + + align:start position:0% + + + + align:start position:0% + +can okay but I can't do it exactly that + + align:start position:0% +can okay but I can't do it exactly that + + + align:start position:0% +can okay but I can't do it exactly that +was actually sort of a that's okay I + + align:start position:0% +was actually sort of a that's okay I + + + align:start position:0% +was actually sort of a that's okay I +mean I can't do it exactly because all + + align:start position:0% +mean I can't do it exactly because all + + + align:start position:0% +mean I can't do it exactly because all +I'm allowed to do is change I have one + + align:start position:0% +I'm allowed to do is change I have one + + + align:start position:0% +I'm allowed to do is change I have one +component that I'm not allowed to change + + align:start position:0% +component that I'm not allowed to change + + + align:start position:0% +component that I'm not allowed to change +right I have the + + align:start position:0% +right I have the + + + align:start position:0% +right I have the +my my Q is going to go forward + + align:start position:0% +my my Q is going to go forward + + + align:start position:0% +my my Q is going to go forward +independent of of U directly so B + + align:start position:0% +independent of of U directly so B + + + align:start position:0% +independent of of U directly so B +transpose SX is going to be give me a + + align:start position:0% +transpose SX is going to be give me a + + + align:start position:0% +transpose SX is going to be give me a +project of that gradient onto this the + + align:start position:0% +project of that gradient onto this the + + + align:start position:0% +project of that gradient onto this the +thing I can actually control which way I + + align:start position:0% +thing I can actually control which way I + + + align:start position:0% +thing I can actually control which way I +can point my my phase portrait in that + + align:start position:0% +can point my my phase portrait in that + + + align:start position:0% +can point my my phase portrait in that +given my + + align:start position:0% +given my + + + align:start position:0% +given my +control okay and then R is going to + + align:start position:0% +control okay and then R is going to + + + align:start position:0% +control okay and then R is going to +scale it again and the resulting um Clos + + align:start position:0% +scale it again and the resulting um Clos + + + align:start position:0% +scale it again and the resulting um Clos +Loop + + align:start position:0% +Loop + + + align:start position:0% +Loop +Dynamics let's see if we can figure that + + align:start position:0% +Dynamics let's see if we can figure that + + + align:start position:0% +Dynamics let's see if we can figure that +out um so if I take the I vectors and I + + align:start position:0% +out um so if I take the I vectors and I + + + align:start position:0% +out um so if I take the I vectors and I +values of that oh it turns out I'm not + + align:start position:0% +values of that oh it turns out I'm not + + + align:start position:0% +values of that oh it turns out I'm not +going to make the plot my igen values + + align:start position:0% +going to make the plot my igen values + + + align:start position:0% +going to make the plot my igen values +were + + align:start position:0% +were + + + align:start position:0% +were +um S 2 plus or minus I 1/ < TK + + align:start position:0% + + + + align:start position:0% + +two with + + align:start position:0% +two with + + + align:start position:0% +two with +V + + align:start position:0% +V + + + align:start position:0% +V +being 1un + + align:start position:0% + + + + align:start position:0% + +two so the best thing I can possibly do + + align:start position:0% +two so the best thing I can possibly do + + + align:start position:0% +two so the best thing I can possibly do +is to um go down that if I didn't care + + align:start position:0% +is to um go down that if I didn't care + + + align:start position:0% +is to um go down that if I didn't care +about um if I didn't worry about + + align:start position:0% +about um if I didn't worry about + + + align:start position:0% +about um if I didn't worry about +penalizing R I didn't worry about my + + align:start position:0% +penalizing R I didn't worry about my + + + align:start position:0% +penalizing R I didn't worry about my +control accuration would be to go + + align:start position:0% +control accuration would be to go + + + align:start position:0% +control accuration would be to go +straight down that bowl okay but because + + align:start position:0% +straight down that bowl okay but because + + + align:start position:0% +straight down that bowl okay but because +I'm scaling things by I'm filtering + + align:start position:0% +I'm scaling things by I'm filtering + + + align:start position:0% +I'm scaling things by I'm filtering +things by where I what I can actually + + align:start position:0% +things by where I what I can actually + + + align:start position:0% +things by where I what I can actually +control and I'm penalizing things by R + + align:start position:0% +control and I'm penalizing things by R + + + align:start position:0% +control and I'm penalizing things by R +the actual response is a complex + + align:start position:0% +the actual response is a complex + + + align:start position:0% +the actual response is a complex +response which goes down um goes down + + align:start position:0% +response which goes down um goes down + + + align:start position:0% +response which goes down um goes down +this bow and and oscillates its way into + + align:start position:0% +this bow and and oscillates its way into + + + align:start position:0% +this bow and and oscillates its way into +the to the + + align:start position:0% +the to the + + + align:start position:0% +the to the +origin + + align:start position:0% +origin + + + align:start position:0% +origin +okay + + align:start position:0% + + + + align:start position:0% + +okay good that was a little painful but + + align:start position:0% +okay good that was a little painful but + + + align:start position:0% +okay good that was a little painful but +that is + + align:start position:0% +that is + + + align:start position:0% +that is +um a set of tools that we're going to + + align:start position:0% +um a set of tools that we're going to + + + align:start position:0% +um a set of tools that we're going to +we're going to lean on when we're making + + align:start position:0% +we're going to lean on when we're making + + + align:start position:0% +we're going to lean on when we're making +all our + + align:start position:0% +all our + + + align:start position:0% +all our +algorithms um you've now seen a + + align:start position:0% +algorithms um you've now seen a + + + align:start position:0% +algorithms um you've now seen a +pretty representative sampling of what + + align:start position:0% +pretty representative sampling of what + + + align:start position:0% +pretty representative sampling of what +people can do analytically with optimal + + align:start position:0% +people can do analytically with optimal + + + align:start position:0% +people can do analytically with optimal +control okay when you have a linear + + align:start position:0% +control okay when you have a linear + + + align:start position:0% +control okay when you have a linear +dynamical + + align:start position:0% +dynamical + + + align:start position:0% +dynamical +system and there's a handful of cost + + align:start position:0% +system and there's a handful of cost + + + align:start position:0% +system and there's a handful of cost +functions which you can anal either by + + align:start position:0% +functions which you can anal either by + + + align:start position:0% +functions which you can anal either by +pontryagin or or dynamic programming the + + align:start position:0% +pontryagin or or dynamic programming the + + + align:start position:0% +pontryagin or or dynamic programming the +the Hamilton Bellman jacobe sufficiency + + align:start position:0% +the Hamilton Bellman jacobe sufficiency + + + align:start position:0% +the Hamilton Bellman jacobe sufficiency +theorem those are really the two big + + align:start position:0% +theorem those are really the two big + + + align:start position:0% +theorem those are really the two big +tools that are out there okay um in + + align:start position:0% +tools that are out there okay um in + + + align:start position:0% +tools that are out there okay um in +cases especially for linear systems you + + align:start position:0% +cases especially for linear systems you + + + align:start position:0% +cases especially for linear systems you +can analytically come up with optimal + + align:start position:0% +can analytically come up with optimal + + + align:start position:0% +can analytically come up with optimal +control policies and value functions + + align:start position:0% +control policies and value functions + + + align:start position:0% +control policies and value functions +okay um why did we distinguish between + + align:start position:0% +okay um why did we distinguish between + + + align:start position:0% +okay um why did we distinguish between +why did I use one um uh in one place and + + align:start position:0% +why did I use one um uh in one place and + + + align:start position:0% +why did I use one um uh in one place and +the other in the other place well it + + align:start position:0% +the other in the other place well it + + + align:start position:0% +the other in the other place well it +turns out the um the Hamilton Bellman + + align:start position:0% +turns out the um the Hamilton Bellman + + + align:start position:0% +turns out the um the Hamilton Bellman +jacobe sufficiency + + align:start position:0% +jacobe sufficiency + + + align:start position:0% +jacobe sufficiency +theorem has in + + align:start position:0% +theorem has in + + + align:start position:0% +theorem has in +it these partial JS partial X partial J + + align:start position:0% +it these partial JS partial X partial J + + + align:start position:0% +it these partial JS partial X partial J +partial T okay so it's only valid + + align:start position:0% +partial T okay so it's only valid + + + align:start position:0% +partial T okay so it's only valid +actually if partial J a partial X is is + + align:start position:0% + + + + align:start position:0% + +smooth + + align:start position:0% +smooth + + + align:start position:0% +smooth +the um the policy we got from minimum + + align:start position:0% +the um the policy we got from minimum + + + align:start position:0% +the um the policy we got from minimum +time has this hard nonlinearity in the + + align:start position:0% +time has this hard nonlinearity in the + + + align:start position:0% +time has this hard nonlinearity in the +middle of + + align:start position:0% +middle of + + + align:start position:0% +middle of +it turns out the the value function that + + align:start position:0% +it turns out the the value function that + + + align:start position:0% +it turns out the the value function that +you have uh in the minimum time problem + + align:start position:0% +you have uh in the minimum time problem + + + align:start position:0% +you have uh in the minimum time problem +also has a hard nonlinearity in it okay + + align:start position:0% +also has a hard nonlinearity in it okay + + + align:start position:0% +also has a hard nonlinearity in it okay +if I'm here versus here it it's smooth + + align:start position:0% +if I'm here versus here it it's smooth + + + align:start position:0% +if I'm here versus here it it's smooth +but the gradients are not smooth the the + + align:start position:0% +but the gradients are not smooth the the + + + align:start position:0% +but the gradients are not smooth the the +gradient is + + align:start position:0% +gradient is + + + align:start position:0% +gradient is +discontinuous so at this on this cusp + + align:start position:0% +discontinuous so at this on this cusp + + + align:start position:0% +discontinuous so at this on this cusp +partial J partial X is + + align:start position:0% +partial J partial X is + + + align:start position:0% +partial J partial X is +undefined okay so that's the only reason + + align:start position:0% +undefined okay so that's the only reason + + + align:start position:0% +undefined okay so that's the only reason +why I didn't lean on the sufficiency + + align:start position:0% +why I didn't lean on the sufficiency + + + align:start position:0% +why I didn't lean on the sufficiency +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +completely okay how did pontryagin get + + align:start position:0% +completely okay how did pontryagin get + + + align:start position:0% +completely okay how did pontryagin get +around that the sufficiency theorem is + + align:start position:0% +around that the sufficiency theorem is + + + align:start position:0% +around that the sufficiency theorem is +talking about + + align:start position:0% +talking about + + + align:start position:0% +talking about +um it it's a it's it's looking at over + + align:start position:0% +um it it's a it's it's looking at over + + + align:start position:0% +um it it's a it's it's looking at over +roughly over the entire State space it's + + align:start position:0% +roughly over the entire State space it's + + + align:start position:0% +roughly over the entire State space it's +it's looking at at + + align:start position:0% +it's looking at at + + + align:start position:0% +it's looking at at +variations in the cost to go function as + + align:start position:0% +variations in the cost to go function as + + + align:start position:0% +variations in the cost to go function as +I move in X and in time pontryagin if + + align:start position:0% +I move in X and in time pontryagin if + + + align:start position:0% +I move in X and in time pontryagin if +you remember was along a particular + + align:start position:0% +you remember was along a particular + + + align:start position:0% +you remember was along a particular +trajectory it was verifying that a + + align:start position:0% +trajectory it was verifying that a + + + align:start position:0% +trajectory it was verifying that a +particular trajectory was locally + + align:start position:0% +particular trajectory was locally + + + align:start position:0% +particular trajectory was locally +optimal okay and it turns out in + + align:start position:0% +optimal okay and it turns out in + + + align:start position:0% +optimal okay and it turns out in +problems like this in these bang bang + + align:start position:0% +problems like this in these bang bang + + + align:start position:0% +problems like this in these bang bang +problems um along a particular + + align:start position:0% +problems um along a particular + + + align:start position:0% +problems um along a particular +trajectory my cost to go is + + align:start position:0% +trajectory my cost to go is + + + align:start position:0% +trajectory my cost to go is +smooth okay the the cost to go the + + align:start position:0% +smooth okay the the cost to go the + + + align:start position:0% +smooth okay the the cost to go the +minimum time problem was was just time + + align:start position:0% +minimum time problem was was just time + + + align:start position:0% +minimum time problem was was just time +right so um so the time I get um the + + align:start position:0% +right so um so the time I get um the + + + align:start position:0% +right so um so the time I get um the +time it takes for me to go to here to + + align:start position:0% +time it takes for me to go to here to + + + align:start position:0% +time it takes for me to go to here to +here is just smoothly decreasing as I + + align:start position:0% +here is just smoothly decreasing as I + + + align:start position:0% +here is just smoothly decreasing as I +get closer like time okay along any + + align:start position:0% +get closer like time okay along any + + + align:start position:0% +get closer like time okay along any +trajectory with these additive + + align:start position:0% +trajectory with these additive + + + align:start position:0% +trajectory with these additive +costs the value function is going to be + + align:start position:0% +costs the value function is going to be + + + align:start position:0% +costs the value function is going to be +smooth but along a non-system trajectory + + align:start position:0% +smooth but along a non-system trajectory + + + align:start position:0% +smooth but along a non-system trajectory +some line like this partial if I just + + align:start position:0% +some line like this partial if I just + + + align:start position:0% +some line like this partial if I just +look at J how J varies over X it's not + + align:start position:0% +look at J how J varies over X it's not + + + align:start position:0% +look at J how J varies over X it's not +smooth + + align:start position:0% +smooth + + + align:start position:0% +smooth +okay so pontryagin is a weaker statement + + align:start position:0% +okay so pontryagin is a weaker statement + + + align:start position:0% +okay so pontryagin is a weaker statement +it's a statement about local stability + + align:start position:0% +it's a statement about local stability + + + align:start position:0% +it's a statement about local stability +along a trajectory but it's valid in + + align:start position:0% +along a trajectory but it's valid in + + + align:start position:0% +along a trajectory but it's valid in +slightly larger domains because it + + align:start position:0% +slightly larger domains because it + + + align:start position:0% +slightly larger domains because it +doesn't rely on on value functions being + + align:start position:0% +doesn't rely on on value functions being + + + align:start position:0% +doesn't rely on on value functions being +smoothly + + align:start position:0% +smoothly + + + align:start position:0% +smoothly +differentiable + + align:start position:0% + + + + align:start position:0% + +okay now for the um for the first order + + align:start position:0% +okay now for the um for the first order + + + align:start position:0% +okay now for the um for the first order +um or s for the double integrator the + + align:start position:0% +um or s for the double integrator the + + + align:start position:0% +um or s for the double integrator the +brick on Ice we could have just chosen + + align:start position:0% +brick on Ice we could have just chosen + + + align:start position:0% +brick on Ice we could have just chosen +our KS by hand and push them um higher + + align:start position:0% +our KS by hand and push them um higher + + + align:start position:0% +our KS by hand and push them um higher +or smaller we could do root Locus we + + align:start position:0% +or smaller we could do root Locus we + + + align:start position:0% +or smaller we could do root Locus we +could figure out a pretty reasonable set + + align:start position:0% +could figure out a pretty reasonable set + + + align:start position:0% +could figure out a pretty reasonable set +of KS um of feedback gains to make it + + align:start position:0% +of KS um of feedback gains to make it + + + align:start position:0% +of KS um of feedback gains to make it +stabilize to the goal lqr gives us a + + align:start position:0% +stabilize to the goal lqr gives us a + + + align:start position:0% +stabilize to the goal lqr gives us a +different set of knobs that we could + + align:start position:0% +different set of knobs that we could + + + align:start position:0% +different set of knobs that we could +tune now we could more explicitly say + + align:start position:0% +tune now we could more explicitly say + + + align:start position:0% +tune now we could more explicitly say +what our concern is for getting to the + + align:start position:0% +what our concern is for getting to the + + + align:start position:0% +what our concern is for getting to the +goal by the Q Matrix versus what our + + align:start position:0% +goal by the Q Matrix versus what our + + + align:start position:0% +goal by the Q Matrix versus what our +concern is about using a lot of cost in + + align:start position:0% +concern is about using a lot of cost in + + + align:start position:0% +concern is about using a lot of cost in +the our + + align:start position:0% +the our + + + align:start position:0% +the our +Matrix okay so maybe that's not very + + align:start position:0% +Matrix okay so maybe that's not very + + + align:start position:0% +Matrix okay so maybe that's not very +compelling maybe we just did a lot of + + align:start position:0% +compelling maybe we just did a lot of + + + align:start position:0% +compelling maybe we just did a lot of +work to just have a slightly different + + align:start position:0% +work to just have a slightly different + + + align:start position:0% +work to just have a slightly different +set of knobs to turn when I'm designing + + align:start position:0% +set of knobs to turn when I'm designing + + + align:start position:0% +set of knobs to turn when I'm designing +my feedback controller but what you're + + align:start position:0% +my feedback controller but what you're + + + align:start position:0% +my feedback controller but what you're +going to see is that for much more + + align:start position:0% +going to see is that for much more + + + align:start position:0% +going to see is that for much more +complicated systems that are still + + align:start position:0% +complicated systems that are still + + + align:start position:0% +complicated systems that are still +linear or linearizations about very + + align:start position:0% +linear or linearizations about very + + + align:start position:0% +linear or linearizations about very +complicated systems lqr is going to give + + align:start position:0% +complicated systems lqr is going to give + + + align:start position:0% +complicated systems lqr is going to give +you an explicit way to design these + + align:start position:0% +you an explicit way to design these + + + align:start position:0% +you an explicit way to design these +linear feedback controllers in a way + + align:start position:0% +linear feedback controllers in a way + + + align:start position:0% +linear feedback controllers in a way +that's that's that's + + align:start position:0% +that's that's that's + + + align:start position:0% +that's that's that's +optimal okay so we're actually you know + + align:start position:0% +optimal okay so we're actually you know + + + align:start position:0% +optimal okay so we're actually you know +doing a variation of lqr now to make an + + align:start position:0% +doing a variation of lqr now to make an + + + align:start position:0% +doing a variation of lqr now to make an +airplane land on a perch right for + + align:start position:0% +airplane land on a perch right for + + + align:start position:0% +airplane land on a perch right for +instance um we can we're going to use it + + align:start position:0% +instance um we can we're going to use it + + + align:start position:0% +instance um we can we're going to use it +to stabilize the double inverted + + align:start position:0% +to stabilize the double inverted + + + align:start position:0% +to stabilize the double inverted +pendulum the acrobot around the top okay + + align:start position:0% +pendulum the acrobot around the top okay + + + align:start position:0% +pendulum the acrobot around the top okay +so it's going to be a generally more + + align:start position:0% +so it's going to be a generally more + + + align:start position:0% +so it's going to be a generally more +useful tool at down at the brick double + + align:start position:0% +useful tool at down at the brick double + + + align:start position:0% +useful tool at down at the brick double +integrator level you could think it's + + align:start position:0% +integrator level you could think it's + + + align:start position:0% +integrator level you could think it's +almost just a different set of ways to + + align:start position:0% +almost just a different set of ways to + + + align:start position:0% +almost just a different set of ways to +do your root + + align:start position:0% + + + + align:start position:0% + +Locus okay you have now through two sort + + align:start position:0% +Locus okay you have now through two sort + + + align:start position:0% +Locus okay you have now through two sort +of dry lectures relative to the rest of + + align:start position:0% +of dry lectures relative to the rest of + + + align:start position:0% +of dry lectures relative to the rest of +the class learned two um uh two ways to + + align:start position:0% +the class learned two um uh two ways to + + + align:start position:0% +the class learned two um uh two ways to +do analytical optimal control okay one + + align:start position:0% +do analytical optimal control okay one + + + align:start position:0% +do analytical optimal control okay one +is by means of the pontryagin's minimum + + align:start position:0% +is by means of the pontryagin's minimum + + + align:start position:0% +is by means of the pontryagin's minimum +principle one's by means of dynamic + + align:start position:0% +principle one's by means of dynamic + + + align:start position:0% +principle one's by means of dynamic +programming which through the hjb + + align:start position:0% +programming which through the hjb + + + align:start position:0% +programming which through the hjb +sufficiency + + align:start position:0% +sufficiency + + + align:start position:0% +sufficiency +theorem okay and you've seen some + + align:start position:0% +theorem okay and you've seen some + + + align:start position:0% +theorem okay and you've seen some +representatives of what people can do + + align:start position:0% +representatives of what people can do + + + align:start position:0% +representatives of what people can do +with those analytical optimal control + + align:start position:0% +with those analytical optimal control + + + align:start position:0% +with those analytical optimal control +and it got us far enough to to make a + + align:start position:0% +and it got us far enough to to make a + + + align:start position:0% +and it got us far enough to to make a +brick go to the origin + + align:start position:0% +brick go to the origin + + + align:start position:0% +brick go to the origin +okay uh right and and it'll do a few + + align:start position:0% +okay uh right and and it'll do a few + + + align:start position:0% +okay uh right and and it'll do a few +more things but okay so so that's about + + align:start position:0% +more things but okay so so that's about + + + align:start position:0% +more things but okay so so that's about +as far as we get with analytics right + + align:start position:0% +as far as we get with analytics right + + + align:start position:0% +as far as we get with analytics right +we're going to use this in places to to + + align:start position:0% +we're going to use this in places to to + + + align:start position:0% +we're going to use this in places to to +start algorithms up but if we wanted for + + align:start position:0% +start algorithms up but if we wanted for + + + align:start position:0% +start algorithms up but if we wanted for +instance solve the um the minimum time + + align:start position:0% +instance solve the um the minimum time + + + align:start position:0% +instance solve the um the minimum time +problem or the quadratic regulator + + align:start position:0% +problem or the quadratic regulator + + + align:start position:0% +problem or the quadratic regulator +problem for the nonlinear dynamics of + + align:start position:0% +problem for the nonlinear dynamics of + + + align:start position:0% +problem for the nonlinear dynamics of +the + + align:start position:0% +the + + + align:start position:0% +the +pendulum right if I in if I take my X + + align:start position:0% +pendulum right if I in if I take my X + + + align:start position:0% +pendulum right if I in if I take my X +doal ax plus bu away and give it the mgl + + align:start position:0% +doal ax plus bu away and give it the mgl + + + align:start position:0% +doal ax plus bu away and give it the mgl +sin + + align:start position:0% +sin + + + align:start position:0% +sin +Theta then most of these tools break + + align:start position:0% +Theta then most of these tools break + + + align:start position:0% +Theta then most of these tools break +down okay next Tuesday happens to be a + + align:start position:0% +down okay next Tuesday happens to be a + + + align:start position:0% +down okay next Tuesday happens to be a +holiday virtual Monday so we won't do it + + align:start position:0% +holiday virtual Monday so we won't do it + + + align:start position:0% +holiday virtual Monday so we won't do it +on next Tuesday but next Thursday I'm + + align:start position:0% +on next Tuesday but next Thursday I'm + + + align:start position:0% +on next Tuesday but next Thursday I'm +going to show you algorithms that are + + align:start position:0% +going to show you algorithms that are + + + align:start position:0% +going to show you algorithms that are +based on these this is a the important + + align:start position:0% +based on these this is a the important + + + align:start position:0% +based on these this is a the important +foundation that are going to solve + + align:start position:0% +foundation that are going to solve + + + align:start position:0% +foundation that are going to solve +algorithmically the same optimal control + + align:start position:0% +algorithmically the same optimal control + + + align:start position:0% +algorithmically the same optimal control +problems that we're um a more optimal + + align:start position:0% +problems that we're um a more optimal + + + align:start position:0% +problems that we're um a more optimal +control problems than we can solve + + align:start position:0% +control problems than we can solve + + + align:start position:0% +control problems than we can solve +analytically + + align:start position:0% +analytically + + + align:start position:0% +analytically +okay and then the uh we'll go on from + + align:start position:0% +okay and then the uh we'll go on from + + + align:start position:0% +okay and then the uh we'll go on from +there to more and more complicated + + align:start position:0% +there to more and more complicated + + + align:start position:0% +there to more and more complicated +systems \ No newline at end of file diff --git a/8PdnOZI7H5E.txt b/8PdnOZI7H5E.txt new file mode 100644 index 0000000000000000000000000000000000000000..bcc959b1a848d4b59b270e42ff81db2bd9c99478 --- /dev/null +++ b/8PdnOZI7H5E.txt @@ -0,0 +1,16603 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +coreware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu everyone cud on that all + + align:start position:0% +ocw.mit.edu everyone cud on that all + + + align:start position:0% +ocw.mit.edu everyone cud on that all +right cool so So today we're going to + + align:start position:0% +right cool so So today we're going to + + + align:start position:0% +right cool so So today we're going to +talk about the uh economics of spam and + + align:start position:0% +talk about the uh economics of spam and + + + align:start position:0% +talk about the uh economics of spam and +Security in general and so up to this + + align:start position:0% +Security in general and so up to this + + + align:start position:0% +Security in general and so up to this +point in the class we've mainly talked + + align:start position:0% +point in the class we've mainly talked + + + align:start position:0% +point in the class we've mainly talked +about the technical aspects of security + + align:start position:0% +about the technical aspects of security + + + align:start position:0% +about the technical aspects of security +so we've looked at things like buffer + + align:start position:0% +so we've looked at things like buffer + + + align:start position:0% +so we've looked at things like buffer +overflows the same origin policy tour + + align:start position:0% +overflows the same origin policy tour + + + align:start position:0% +overflows the same origin policy tour +and all kinds of things like that and so + + align:start position:0% +and all kinds of things like that and so + + + align:start position:0% +and all kinds of things like that and so +the context for that discussion was that + + align:start position:0% +the context for that discussion was that + + + align:start position:0% +the context for that discussion was that +we were looking at how an adversary can + + align:start position:0% +we were looking at how an adversary can + + + align:start position:0% +we were looking at how an adversary can +compromise a system we tried to devise a + + align:start position:0% +compromise a system we tried to devise a + + + align:start position:0% +compromise a system we tried to devise a +threat model that would describe the + + align:start position:0% +threat model that would describe the + + + align:start position:0% +threat model that would describe the +types of things we want to prevent and + + align:start position:0% +types of things we want to prevent and + + + align:start position:0% +types of things we want to prevent and +then we Tred to think about how we could + + align:start position:0% +then we Tred to think about how we could + + + align:start position:0% +then we Tred to think about how we could +design systems that would help us to + + align:start position:0% +design systems that would help us to + + + align:start position:0% +design systems that would help us to +defend against that threat model um so + + align:start position:0% +defend against that threat model um so + + + align:start position:0% +defend against that threat model um so +today we're going to look at an + + align:start position:0% +today we're going to look at an + + + align:start position:0% +today we're going to look at an +alternate perspective and the + + align:start position:0% +alternate perspective and the + + + align:start position:0% +alternate perspective and the +perspective that we'll look at today is + + align:start position:0% +perspective that we'll look at today is + + + align:start position:0% +perspective that we'll look at today is +why is the attacker trying to compromise + + align:start position:0% +why is the attacker trying to compromise + + + align:start position:0% +why is the attacker trying to compromise +our system why is the attacker trying to + + align:start position:0% +our system why is the attacker trying to + + + align:start position:0% +our system why is the attacker trying to +do these evil things to us and so + + align:start position:0% +do these evil things to us and so + + + align:start position:0% +do these evil things to us and so +there's a bunch of different reasons you + + align:start position:0% +there's a bunch of different reasons you + + + align:start position:0% +there's a bunch of different reasons you +can imagine why uh attackers might be + + align:start position:0% +can imagine why uh attackers might be + + + align:start position:0% +can imagine why uh attackers might be +trying to do these evil things uh so + + align:start position:0% +trying to do these evil things uh so + + + align:start position:0% +trying to do these evil things uh so +some of these attacks are done for you + + align:start position:0% +some of these attacks are done for you + + + align:start position:0% +some of these attacks are done for you +know ideological reasons so think about + + align:start position:0% +know ideological reasons so think about + + + align:start position:0% +know ideological reasons so think about +people who perceive themselves to be + + align:start position:0% +people who perceive themselves to be + + + align:start position:0% +people who perceive themselves to be +political activists or things like like + + align:start position:0% +political activists or things like like + + + align:start position:0% +political activists or things like like +that or if you think about uh stuck net + + align:start position:0% +that or if you think about uh stuck net + + + align:start position:0% +that or if you think about uh stuck net +for example and sometimes it's like + + align:start position:0% +for example and sometimes it's like + + + align:start position:0% +for example and sometimes it's like +government's attacking other governments + + align:start position:0% +government's attacking other governments + + + align:start position:0% +government's attacking other governments +right and so for these types of attacks + + align:start position:0% +right and so for these types of attacks + + + align:start position:0% +right and so for these types of attacks +uh money economics is not the primary + + align:start position:0% +uh money economics is not the primary + + + align:start position:0% +uh money economics is not the primary +motivation for the attack to take place + + align:start position:0% +motivation for the attack to take place + + + align:start position:0% +motivation for the attack to take place +uh and what's interesting is that it's + + align:start position:0% +uh and what's interesting is that it's + + + align:start position:0% +uh and what's interesting is that it's +it's actually hard to make these attacks + + align:start position:0% +it's actually hard to make these attacks + + + align:start position:0% +it's actually hard to make these attacks +go away other than generically making + + align:start position:0% +go away other than generically making + + + align:start position:0% +go away other than generically making +computers more secure right so there's + + align:start position:0% +computers more secure right so there's + + + align:start position:0% +computers more secure right so there's +not really sort of a financial thumb + + align:start position:0% +not really sort of a financial thumb + + + align:start position:0% +not really sort of a financial thumb +screw you can turn to make uh these + + align:start position:0% +screw you can turn to make uh these + + + align:start position:0% +screw you can turn to make uh these +attackers disincentivized to do things + + align:start position:0% +attackers disincentivized to do things + + + align:start position:0% +attackers disincentivized to do things +uh + + align:start position:0% +uh + + + align:start position:0% +uh +however there are um some types of + + align:start position:0% +however there are um some types of + + + align:start position:0% +however there are um some types of +attacks that do involve a strong + + align:start position:0% +attacks that do involve a strong + + + align:start position:0% +attacks that do involve a strong +economic component and those are some of + + align:start position:0% +economic component and those are some of + + + align:start position:0% +economic component and those are some of +the things we're going to look at today + + align:start position:0% +the things we're going to look at today + + + align:start position:0% +the things we're going to look at today +you know one of the interesting things + + align:start position:0% +you know one of the interesting things + + + align:start position:0% +you know one of the interesting things +though is that for a lot of these + + align:start position:0% +though is that for a lot of these + + + align:start position:0% +though is that for a lot of these +attacks that don't have an economic + + align:start position:0% +attacks that don't have an economic + + + align:start position:0% +attacks that don't have an economic +component and that we can't use + + align:start position:0% +component and that we can't use + + + align:start position:0% +component and that we can't use +regulation or things like that to try to + + align:start position:0% +regulation or things like that to try to + + + align:start position:0% +regulation or things like that to try to +prevent them it can sometimes be + + align:start position:0% +prevent them it can sometimes be + + + align:start position:0% +prevent them it can sometimes be +difficult to figure out you know how + + align:start position:0% +difficult to figure out you know how + + + align:start position:0% +difficult to figure out you know how +we'd be able to stop them at all Beyond + + align:start position:0% +we'd be able to stop them at all Beyond + + + align:start position:0% +we'd be able to stop them at all Beyond +like I said just trying to make + + align:start position:0% +like I said just trying to make + + + align:start position:0% +like I said just trying to make +computers more secure so for example Stu + + align:start position:0% +computers more secure so for example Stu + + + align:start position:0% +computers more secure so for example Stu +Net's a great idea right so this is the + + align:start position:0% +Net's a great idea right so this is the + + + align:start position:0% +Net's a great idea right so this is the +uh malware that was attacking some of + + align:start position:0% +uh malware that was attacking some of + + + align:start position:0% +uh malware that was attacking some of +the industrial software uh in Iran with + + align:start position:0% +the industrial software uh in Iran with + + + align:start position:0% +the industrial software uh in Iran with +the centrifuges so you know we all kind + + align:start position:0% +the centrifuges so you know we all kind + + + align:start position:0% +the centrifuges so you know we all kind +of know where stuck neet came from right + + align:start position:0% +of know where stuck neet came from right + + + align:start position:0% +of know where stuck neet came from right +we basically know it was the Americans + + align:start position:0% +we basically know it was the Americans + + + align:start position:0% +we basically know it was the Americans +and the Israelis basically but can we + + align:start position:0% +and the Israelis basically but can we + + + align:start position:0% +and the Israelis basically but can we +prove that in a court of law right like + + align:start position:0% +prove that in a court of law right like + + + align:start position:0% +prove that in a court of law right like +who can we Sue to say like you put stuck + + align:start position:0% +who can we Sue to say like you put stuck + + + align:start position:0% +who can we Sue to say like you put stuck +neck on our machine right so it becomes + + align:start position:0% +neck on our machine right so it becomes + + + align:start position:0% +neck on our machine right so it becomes +a little bit mgy when you have some of + + align:start position:0% +a little bit mgy when you have some of + + + align:start position:0% +a little bit mgy when you have some of +these attacks where it's not clear you + + align:start position:0% +these attacks where it's not clear you + + + align:start position:0% +these attacks where it's not clear you +can you know sue the Federal Reserve or + + align:start position:0% +can you know sue the Federal Reserve or + + + align:start position:0% +can you know sue the Federal Reserve or +you can sue Israel or something like + + align:start position:0% +you can sue Israel or something like + + + align:start position:0% +you can sue Israel or something like +this and furthermore no one's gone on + + align:start position:0% +this and furthermore no one's gone on + + + align:start position:0% +this and furthermore no one's gone on +the record is officially claiming that + + align:start position:0% +the record is officially claiming that + + + align:start position:0% +the record is officially claiming that +it was them so there's some very + + align:start position:0% +it was them so there's some very + + + align:start position:0% +it was them so there's some very +interesting sort of legal and financial + + align:start position:0% +interesting sort of legal and financial + + + align:start position:0% +interesting sort of legal and financial +issues that get around that get involved + + align:start position:0% +issues that get around that get involved + + + align:start position:0% +issues that get around that get involved +when you look at how to prevent these + + align:start position:0% +when you look at how to prevent these + + + align:start position:0% +when you look at how to prevent these +attacks so there are many kinds of + + align:start position:0% +attacks so there are many kinds of + + + align:start position:0% +attacks so there are many kinds of +computer crime that are driven by uh + + align:start position:0% +computer crime that are driven by uh + + + align:start position:0% +computer crime that are driven by uh +economic motivations so for example uh + + align:start position:0% +economic motivations so for example uh + + + align:start position:0% +economic motivations so for example uh +state sponsored industrial Espionage for + + align:start position:0% +state sponsored industrial Espionage for + + + align:start position:0% +state sponsored industrial Espionage for +instance so this is one thing that some + + align:start position:0% +instance so this is one thing that some + + + align:start position:0% +instance so this is one thing that some +of our previous speakers have talked + + align:start position:0% +of our previous speakers have talked + + + align:start position:0% +of our previous speakers have talked +about sometimes governments try to hack + + align:start position:0% +about sometimes governments try to hack + + + align:start position:0% +about sometimes governments try to hack +into other governments or other + + align:start position:0% +into other governments or other + + + align:start position:0% +into other governments or other +Industries to steal intellectual + + align:start position:0% +Industries to steal intellectual + + + align:start position:0% +Industries to steal intellectual +property or things like that uh and + + align:start position:0% +property or things like that uh and + + + align:start position:0% +property or things like that uh and +what's interesting is that like the + + align:start position:0% +what's interesting is that like the + + + align:start position:0% +what's interesting is that like the +attacks that we'll look at today which + + align:start position:0% +attacks that we'll look at today which + + + align:start position:0% +attacks that we'll look at today which +are spam you'll see that it actually + + align:start position:0% +are spam you'll see that it actually + + + align:start position:0% +are spam you'll see that it actually +takes some money to make some money + + align:start position:0% +takes some money to make some money + + + align:start position:0% +takes some money to make some money +right so spammers actually have to + + align:start position:0% +right so spammers actually have to + + + align:start position:0% +right so spammers actually have to +invest in an infrastructure before they + + align:start position:0% +invest in an infrastructure before they + + + align:start position:0% +invest in an infrastructure before they +can actually send these messages out and + + align:start position:0% +can actually send these messages out and + + + align:start position:0% +can actually send these messages out and +so if you have these attacks where you + + align:start position:0% +so if you have these attacks where you + + + align:start position:0% +so if you have these attacks where you +know it takes money to make money and + + align:start position:0% +know it takes money to make money and + + + align:start position:0% +know it takes money to make money and +you can figure out what that Financial + + align:start position:0% +you can figure out what that Financial + + + align:start position:0% +you can figure out what that Financial +uh sort of tool chain looks like then + + align:start position:0% +uh sort of tool chain looks like then + + + align:start position:0% +uh sort of tool chain looks like then +maybe you can think about applying + + align:start position:0% +maybe you can think about applying + + + align:start position:0% +maybe you can think about applying +Upstream Financial pressure to sort of + + align:start position:0% +Upstream Financial pressure to sort of + + + align:start position:0% +Upstream Financial pressure to sort of +stop that Downstream uh sort of malware + + align:start position:0% +stop that Downstream uh sort of malware + + + align:start position:0% +stop that Downstream uh sort of malware +attacks or or security problems and so I + + align:start position:0% +attacks or or security problems and so I + + + align:start position:0% +attacks or or security problems and so I +think the take on point is that if we + + align:start position:0% +think the take on point is that if we + + + align:start position:0% +think the take on point is that if we +look at at the context of spam in + + align:start position:0% +look at at the context of spam in + + + align:start position:0% +look at at the context of spam in +particular you know spammers will stop + + align:start position:0% +particular you know spammers will stop + + + align:start position:0% +particular you know spammers will stop +sending spam if it becomes unprofitable + + align:start position:0% +sending spam if it becomes unprofitable + + + align:start position:0% +sending spam if it becomes unprofitable +right one of the sad truths of the world + + align:start position:0% +right one of the sad truths of the world + + + align:start position:0% +right one of the sad truths of the world +is that we continue to get spam messages + + align:start position:0% +is that we continue to get spam messages + + + align:start position:0% +is that we continue to get spam messages +because it's cheap for them to send them + + align:start position:0% +because it's cheap for them to send them + + + align:start position:0% +because it's cheap for them to send them +and you know 2 to 3% of our fellow human + + align:start position:0% +and you know 2 to 3% of our fellow human + + + align:start position:0% +and you know 2 to 3% of our fellow human +beings will actually click on links and + + align:start position:0% +beings will actually click on links and + + + align:start position:0% +beings will actually click on links and +look at stuff right and so as long as + + align:start position:0% +look at stuff right and so as long as + + + align:start position:0% +look at stuff right and so as long as +these these costs for some of these + + align:start position:0% +these these costs for some of these + + + align:start position:0% +these these costs for some of these +messages out are so low then even if the + + align:start position:0% +messages out are so low then even if the + + + align:start position:0% +messages out are so low then even if the +hit rates are low people can still make + + align:start position:0% +hit rates are low people can still make + + + align:start position:0% +hit rates are low people can still make +money off that kind of stuff so for + + align:start position:0% +money off that kind of stuff so for + + + align:start position:0% +money off that kind of stuff so for +today we are going to look at uh + + align:start position:0% +today we are going to look at uh + + + align:start position:0% +today we are going to look at uh +attacks that have um sort of a + + align:start position:0% +attacks that have um sort of a + + + align:start position:0% +attacks that have um sort of a +significant uh economic component to + + align:start position:0% + + + + align:start position:0% + +them and so one interesting example + + align:start position:0% +them and so one interesting example + + + align:start position:0% +them and so one interesting example +which uh actually just read about uh + + align:start position:0% +which uh actually just read about uh + + + align:start position:0% +which uh actually just read about uh +takes place uh in China and so in China + + align:start position:0% +takes place uh in China and so in China + + + align:start position:0% +takes place uh in China and so in China +they have this problem uh with what they + + align:start position:0% +they have this problem uh with what they + + + align:start position:0% +they have this problem uh with what they +call text message + + align:start position:0% +call text message + + + align:start position:0% +call text message +cars and so the basic idea here is that + + align:start position:0% +cars and so the basic idea here is that + + + align:start position:0% +cars and so the basic idea here is that +people drive around with these cars that + + align:start position:0% +people drive around with these cars that + + + align:start position:0% +people drive around with these cars that +have these radio antennas attached to + + align:start position:0% +have these radio antennas attached to + + + align:start position:0% +have these radio antennas attached to +the side and they can essentially do + + align:start position:0% +the side and they can essentially do + + + align:start position:0% +the side and they can essentially do +think of it almost as like a man in the + + align:start position:0% +think of it almost as like a man in the + + + align:start position:0% +think of it almost as like a man in the +middle between people's uh Mobile cell + + align:start position:0% +middle between people's uh Mobile cell + + + align:start position:0% +middle between people's uh Mobile cell +phones and the actual cell phone tower + + align:start position:0% +phones and the actual cell phone tower + + + align:start position:0% +phones and the actual cell phone tower +and so they can basically run around in + + align:start position:0% +and so they can basically run around in + + + align:start position:0% +and so they can basically run around in +these control cars and they can get all + + align:start position:0% +these control cars and they can get all + + + align:start position:0% +these control cars and they can get all +of these cell phone numbers right and + + align:start position:0% +of these cell phone numbers right and + + + align:start position:0% +of these cell phone numbers right and +then use that car to then send spam + + align:start position:0% +then use that car to then send spam + + + align:start position:0% +then use that car to then send spam +messages directly to the numbers that + + align:start position:0% +messages directly to the numbers that + + + align:start position:0% +messages directly to the numbers that +they've collected using this sort of + + align:start position:0% +they've collected using this sort of + + + align:start position:0% +they've collected using this sort of +vehicle of hate right and so these text + + align:start position:0% +vehicle of hate right and so these text + + + align:start position:0% +vehicle of hate right and so these text +message cards can actually send uh + + align:start position:0% +message cards can actually send uh + + + align:start position:0% +message cards can actually send uh +upward of uh 200,000 messages a + + align:start position:0% +upward of uh 200,000 messages a + + + align:start position:0% +upward of uh 200,000 messages a +day right which is an incredibly High + + align:start position:0% +day right which is an incredibly High + + + align:start position:0% +day right which is an incredibly High +number and the cost of Labor over there + + align:start position:0% +number and the cost of Labor over there + + + align:start position:0% +number and the cost of Labor over there +is actually very cheap so you know it's + + align:start position:0% +is actually very cheap so you know it's + + + align:start position:0% +is actually very cheap so you know it's +very inexpensive to hire a driver drive + + align:start position:0% +very inexpensive to hire a driver drive + + + align:start position:0% +very inexpensive to hire a driver drive +around one of these cars and just sort + + align:start position:0% +around one of these cars and just sort + + + align:start position:0% +around one of these cars and just sort +of Snoop on people's traffic and send + + align:start position:0% +of Snoop on people's traffic and send + + + align:start position:0% +of Snoop on people's traffic and send +them spam so you know let's look at the + + align:start position:0% +them spam so you know let's look at the + + + align:start position:0% +them spam so you know let's look at the +economics of this so uh what is the + + align:start position:0% +economics of this so uh what is the + + + align:start position:0% +economics of this so uh what is the +cost of uh the evil antenna this thing + + align:start position:0% +cost of uh the evil antenna this thing + + + align:start position:0% +cost of uh the evil antenna this thing +that allows people to um take these + + align:start position:0% +that allows people to um take these + + + align:start position:0% +that allows people to um take these +messages off the air so roughly speaking + + align:start position:0% +messages off the air so roughly speaking + + + align:start position:0% +messages off the air so roughly speaking +it's somewhere in the + + align:start position:0% +it's somewhere in the + + + align:start position:0% +it's somewhere in the +order of about 1,600 bucks give or take + + align:start position:0% +order of about 1,600 bucks give or take + + + align:start position:0% +order of about 1,600 bucks give or take +so how much profit can these people make + + align:start position:0% +so how much profit can these people make + + + align:start position:0% +so how much profit can these people make +uh a + + align:start position:0% +uh a + + + align:start position:0% +uh a +day so in a hilarious coincidence this + + align:start position:0% +day so in a hilarious coincidence this + + + align:start position:0% +day so in a hilarious coincidence this +is also roughly uh + + align:start position:0% +is also roughly uh + + + align:start position:0% +is also roughly uh +$1600 so this is very interesting so + + align:start position:0% +$1600 so this is very interesting so + + + align:start position:0% +$1600 so this is very interesting so +what this means is that once you buy one + + align:start position:0% +what this means is that once you buy one + + + align:start position:0% +what this means is that once you buy one +of these things then in a day you've + + align:start position:0% +of these things then in a day you've + + + align:start position:0% +of these things then in a day you've +essentially made back your money okay so + + align:start position:0% +essentially made back your money okay so + + + align:start position:0% +essentially made back your money okay so +that's great from the perspective of + + align:start position:0% +that's great from the perspective of + + + align:start position:0% +that's great from the perspective of +being a spammer now you might say okay + + align:start position:0% +being a spammer now you might say okay + + + align:start position:0% +being a spammer now you might say okay +but you might get caught by the police + + align:start position:0% +but you might get caught by the police + + + align:start position:0% +but you might get caught by the police +and then you know you might get put in + + align:start position:0% +and then you know you might get put in + + + align:start position:0% +and then you know you might get put in +jail have to pay a fine so in the case + + align:start position:0% +jail have to pay a fine so in the case + + + align:start position:0% +jail have to pay a fine so in the case +of uh the fines so the fines for getting + + align:start position:0% + + + + align:start position:0% + +caught are less than uh + + align:start position:0% + + + + align:start position:0% + +5K and people rarely get caught right + + align:start position:0% +5K and people rarely get caught right + + + align:start position:0% +5K and people rarely get caught right +and so these are the types of sort of + + align:start position:0% +and so these are the types of sort of + + + align:start position:0% +and so these are the types of sort of +calculus as we have to look at when + + align:start position:0% +calculus as we have to look at when + + + align:start position:0% +calculus as we have to look at when +we're trying to think about how to + + align:start position:0% +we're trying to think about how to + + + align:start position:0% +we're trying to think about how to +economically uh deter these spammers + + align:start position:0% +economically uh deter these spammers + + + align:start position:0% +economically uh deter these spammers +right because if these spammers only get + + align:start position:0% +right because if these spammers only get + + + align:start position:0% +right because if these spammers only get +caught you know a couple times a year + + align:start position:0% +caught you know a couple times a year + + + align:start position:0% +caught you know a couple times a year +and they basically make back their + + align:start position:0% +and they basically make back their + + + align:start position:0% +and they basically make back their +Hardware cost in a single day it's very + + align:start position:0% +Hardware cost in a single day it's very + + + align:start position:0% +Hardware cost in a single day it's very +tricky to figure out how we can use + + align:start position:0% +tricky to figure out how we can use + + + align:start position:0% +tricky to figure out how we can use +Financial disincentives to make them + + align:start position:0% +Financial disincentives to make them + + + align:start position:0% +Financial disincentives to make them +stop doing this kind of stuff uh and + + align:start position:0% +stop doing this kind of stuff uh and + + + align:start position:0% +stop doing this kind of stuff uh and +what's interesting is that that uh in + + align:start position:0% +what's interesting is that that uh in + + + align:start position:0% +what's interesting is that that uh in +China the the mobile carriers are also + + align:start position:0% +China the the mobile carriers are also + + + align:start position:0% +China the the mobile carriers are also +somewhat implicit in this scheme so + + align:start position:0% +somewhat implicit in this scheme so + + + align:start position:0% +somewhat implicit in this scheme so +every time you send a Spam right you're + + align:start position:0% +every time you send a Spam right you're + + + align:start position:0% +every time you send a Spam right you're +going to send some small amount of money + + align:start position:0% +going to send some small amount of money + + + align:start position:0% +going to send some small amount of money +to the mobile carrier right a couple + + align:start position:0% +to the mobile carrier right a couple + + + align:start position:0% +to the mobile carrier right a couple +cents right it works that way over here + + align:start position:0% +cents right it works that way over here + + + align:start position:0% +cents right it works that way over here +as well now over here in Europe in many + + align:start position:0% +as well now over here in Europe in many + + + align:start position:0% +as well now over here in Europe in many +cases the uh mobile carriers have + + align:start position:0% +cases the uh mobile carriers have + + + align:start position:0% +cases the uh mobile carriers have +decided that they don't want angry + + align:start position:0% +decided that they don't want angry + + + align:start position:0% +decided that they don't want angry +customers contacting them saying I'm + + align:start position:0% +customers contacting them saying I'm + + + align:start position:0% +customers contacting them saying I'm +getting hit by these spam messages all + + align:start position:0% +getting hit by these spam messages all + + + align:start position:0% +getting hit by these spam messages all +the time right but apparently a lot of + + align:start position:0% +the time right but apparently a lot of + + + align:start position:0% +the time right but apparently a lot of +the uh Chinese mobile carers at least + + align:start position:0% +the uh Chinese mobile carers at least + + + align:start position:0% +the uh Chinese mobile carers at least +the top three ones they're actually + + align:start position:0% +the top three ones they're actually + + + align:start position:0% +the top three ones they're actually +seeing these spam messages as a source + + align:start position:0% +seeing these spam messages as a source + + + align:start position:0% +seeing these spam messages as a source +of Revenue right and so they they + + align:start position:0% +of Revenue right and so they they + + + align:start position:0% +of Revenue right and so they they +actually think that this is uh a nice + + align:start position:0% +actually think that this is uh a nice + + + align:start position:0% +actually think that this is uh a nice +way for them to get some free money and + + align:start position:0% +way for them to get some free money and + + + align:start position:0% +way for them to get some free money and +so in fact these as uh Telos have set up + + align:start position:0% +so in fact these as uh Telos have set up + + + align:start position:0% +so in fact these as uh Telos have set up +these things called uh 106 prefix + + align:start position:0% +these things called uh 106 prefix + + + align:start position:0% +these things called uh 106 prefix +numbers I don't know if you've heard of + + align:start position:0% +numbers I don't know if you've heard of + + + align:start position:0% +numbers I don't know if you've heard of +these before + + align:start position:0% +these before + + + align:start position:0% +these before +um but the original there's apparently a + + align:start position:0% +um but the original there's apparently a + + + align:start position:0% +um but the original there's apparently a +ghost in the room uh but the original + + align:start position:0% +ghost in the room uh but the original + + + align:start position:0% +ghost in the room uh but the original +purpose of these numbers was to do + + align:start position:0% +purpose of these numbers was to do + + + align:start position:0% +purpose of these numbers was to do +things for non-commercial reasons so for + + align:start position:0% +things for non-commercial reasons so for + + + align:start position:0% +things for non-commercial reasons so for +Imagine for example imagine that you uh + + align:start position:0% +Imagine for example imagine that you uh + + + align:start position:0% +Imagine for example imagine that you uh +run a company and you want to send a + + align:start position:0% +run a company and you want to send a + + + align:start position:0% +run a company and you want to send a +bunch of text messages to all of your + + align:start position:0% +bunch of text messages to all of your + + + align:start position:0% +bunch of text messages to all of your +employees right you can use one of these + + align:start position:0% +employees right you can use one of these + + + align:start position:0% +employees right you can use one of these +106 uh numbers and you would basically + + align:start position:0% +106 uh numbers and you would basically + + + align:start position:0% +106 uh numbers and you would basically +be able to send things in bulk you'd be + + align:start position:0% +be able to send things in bulk you'd be + + + align:start position:0% +be able to send things in bulk you'd be +able to uh avoid some of the built-in + + align:start position:0% +able to uh avoid some of the built-in + + + align:start position:0% +able to uh avoid some of the built-in +rate limiting mechanisms they have in + + align:start position:0% +rate limiting mechanisms they have in + + + align:start position:0% +rate limiting mechanisms they have in +the cell network so there's this nice + + align:start position:0% +the cell network so there's this nice + + + align:start position:0% +the cell network so there's this nice +thing sitting around that spammers can + + align:start position:0% +thing sitting around that spammers can + + + align:start position:0% +thing sitting around that spammers can +actually use right and so as it turns + + align:start position:0% +actually use right and so as it turns + + + align:start position:0% +actually use right and so as it turns +out uh I think it's something like uh + + align:start position:0% + + + + align:start position:0% + +55% of the mobile spam that gets sent in + + align:start position:0% +55% of the mobile spam that gets sent in + + + align:start position:0% +55% of the mobile spam that gets sent in +China uh comes from one of these 10 six + + align:start position:0% +China uh comes from one of these 10 six + + + align:start position:0% +China uh comes from one of these 10 six +numbers and so this is just a really + + align:start position:0% +numbers and so this is just a really + + + align:start position:0% +numbers and so this is just a really +interesting case study of how you know + + align:start position:0% +interesting case study of how you know + + + align:start position:0% +interesting case study of how you know +sort of these uh Financial numbers work + + align:start position:0% +sort of these uh Financial numbers work + + + align:start position:0% +sort of these uh Financial numbers work +out and how sometimes you can actually + + align:start position:0% +out and how sometimes you can actually + + + align:start position:0% +out and how sometimes you can actually +have uh sort of these perverse + + align:start position:0% +have uh sort of these perverse + + + align:start position:0% +have uh sort of these perverse +incentives for in this case the cell + + align:start position:0% +incentives for in this case the cell + + + align:start position:0% +incentives for in this case the cell +phone carriers to sort of go along with + + align:start position:0% +phone carriers to sort of go along with + + + align:start position:0% +phone carriers to sort of go along with +these spam anding + + align:start position:0% +these spam anding + + + align:start position:0% +these spam anding +sees and there'll be a link in the + + align:start position:0% +sees and there'll be a link in the + + + align:start position:0% +sees and there'll be a link in the +lecture notes there's an interesting uh + + align:start position:0% +lecture notes there's an interesting uh + + + align:start position:0% +lecture notes there's an interesting uh +Economist article about this there's + + align:start position:0% +Economist article about this there's + + + align:start position:0% +Economist article about this there's +like a panafrican drum circle back there + + align:start position:0% +like a panafrican drum circle back there + + + align:start position:0% +like a panafrican drum circle back there +this this is super exciting R I like it + + align:start position:0% +this this is super exciting R I like it + + + align:start position:0% +this this is super exciting R I like it +I am being adversar attacked that's okay + + align:start position:0% +I am being adversar attacked that's okay + + + align:start position:0% +I am being adversar attacked that's okay +we will play through the pain uh perhaps + + align:start position:0% +we will play through the pain uh perhaps + + + align:start position:0% +we will play through the pain uh perhaps +this is the Mah they don't want me to + + align:start position:0% +this is the Mah they don't want me to + + + align:start position:0% +this is the Mah they don't want me to +talk about stck net so uh another + + align:start position:0% +talk about stck net so uh another + + + align:start position:0% +talk about stck net so uh another +interesting thing about uh security is + + align:start position:0% +interesting thing about uh security is + + + align:start position:0% +interesting thing about uh security is +that uh there are actually many uh + + align:start position:0% +that uh there are actually many uh + + + align:start position:0% +that uh there are actually many uh +companies that deal in cyber arms right + + align:start position:0% +companies that deal in cyber arms right + + + align:start position:0% +companies that deal in cyber arms right +and so you know this is kind of like + + align:start position:0% +and so you know this is kind of like + + + align:start position:0% +and so you know this is kind of like +something out of GI Joe but there are + + align:start position:0% +something out of GI Joe but there are + + + align:start position:0% +something out of GI Joe but there are +actually these companies that will sit + + align:start position:0% +actually these companies that will sit + + + align:start position:0% +actually these companies that will sit +around and they will actually sell you + + align:start position:0% +around and they will actually sell you + + + align:start position:0% +around and they will actually sell you +malware they will sell you exploits they + + align:start position:0% +malware they will sell you exploits they + + + align:start position:0% +malware they will sell you exploits they +will sell you things like this uh so one + + align:start position:0% +will sell you things like this uh so one + + + align:start position:0% +will sell you things like this uh so one +example um is this company + + align:start position:0% +example um is this company + + + align:start position:0% +example um is this company +uh that's called uh + + align:start position:0% + + + + align:start position:0% + +ingame and so for example uh for about + + align:start position:0% +ingame and so for example uh for about + + + align:start position:0% +ingame and so for example uh for about +$1.5 + + align:start position:0% + + + + align:start position:0% + +million in-game will give you uh IP + + align:start position:0% +million in-game will give you uh IP + + + align:start position:0% +million in-game will give you uh IP +addresses in the physical + + align:start position:0% + + + + align:start position:0% + +locations of millions of unpatched + + align:start position:0% + + + + align:start position:0% + +machines right so they have sort of + + align:start position:0% +machines right so they have sort of + + + align:start position:0% +machines right so they have sort of +Vantage points all over the Internet and + + align:start position:0% +Vantage points all over the Internet and + + + align:start position:0% +Vantage points all over the Internet and +they know all kinds of interesting + + align:start position:0% +they know all kinds of interesting + + + align:start position:0% +they know all kinds of interesting +information about machines that you may + + align:start position:0% +information about machines that you may + + + align:start position:0% +information about machines that you may +or may not want to attack if for example + + align:start position:0% +or may not want to attack if for example + + + align:start position:0% +or may not want to attack if for example +you're a uh your government or a threel + + align:start position:0% +you're a uh your government or a threel + + + align:start position:0% +you're a uh your government or a threel +agency or something like that uh for uh + + align:start position:0% +agency or something like that uh for uh + + + align:start position:0% +agency or something like that uh for uh +about $2.5 + + align:start position:0% +about $2.5 + + + align:start position:0% +about $2.5 +million they will give you what is + + align:start position:0% +million they will give you what is + + + align:start position:0% +million they will give you what is +delightfully called a uh zerod day + + align:start position:0% +delightfully called a uh zerod day + + + align:start position:0% +delightfully called a uh zerod day +subscription + + align:start position:0% +subscription + + + align:start position:0% +subscription +package and so if you sign up uh for + + align:start position:0% +package and so if you sign up uh for + + + align:start position:0% +package and so if you sign up uh for +this then basically you will get uh 25 + + align:start position:0% +this then basically you will get uh 25 + + + align:start position:0% +this then basically you will get uh 25 +exploits a year they claim for that much + + align:start position:0% +exploits a year they claim for that much + + + align:start position:0% +exploits a year they claim for that much +money and so you'll get those exploits + + align:start position:0% +money and so you'll get those exploits + + + align:start position:0% +money and so you'll get those exploits +in your inbox or whatever and once again + + align:start position:0% +in your inbox or whatever and once again + + + align:start position:0% +in your inbox or whatever and once again +you can do with these things you know + + align:start position:0% +you can do with these things you know + + + align:start position:0% +you can do with these things you know +whatever you want you've clearly got + + align:start position:0% +whatever you want you've clearly got + + + align:start position:0% +whatever you want you've clearly got +$2.5 million so you've got a lot of + + align:start position:0% +$2.5 million so you've got a lot of + + + align:start position:0% +$2.5 million so you've got a lot of +spare time to think about this stuff + + align:start position:0% +spare time to think about this stuff + + + align:start position:0% +spare time to think about this stuff +presumably and so what's interesting is + + align:start position:0% +presumably and so what's interesting is + + + align:start position:0% +presumably and so what's interesting is +that you know a lot of the people who + + align:start position:0% +that you know a lot of the people who + + + align:start position:0% +that you know a lot of the people who +work in these cyber arms dealers they're + + align:start position:0% +work in these cyber arms dealers they're + + + align:start position:0% +work in these cyber arms dealers they're +actually X three-letter agencies right + + align:start position:0% +actually X three-letter agencies right + + + align:start position:0% +actually X three-letter agencies right +they're xcia X NSA or things like this + + align:start position:0% +they're xcia X NSA or things like this + + + align:start position:0% +they're xcia X NSA or things like this +and it's interesting to think about who + + align:start position:0% +and it's interesting to think about who + + + align:start position:0% +and it's interesting to think about who +are the actual customers for these cyber + + align:start position:0% +are the actual customers for these cyber + + + align:start position:0% +are the actual customers for these cyber +arms dealers right some of them are + + align:start position:0% +arms dealers right some of them are + + + align:start position:0% +arms dealers right some of them are +actually government like the American + + align:start position:0% +actually government like the American + + + align:start position:0% +actually government like the American +government for example and they use + + align:start position:0% +government for example and they use + + + align:start position:0% +government for example and they use +these things to attack other nations or + + align:start position:0% +these things to attack other nations or + + + align:start position:0% +these things to attack other nations or +whatever but some of the uh people who + + align:start position:0% +whatever but some of the uh people who + + + align:start position:0% +whatever but some of the uh people who +buy this stuff are actually increasingly + + align:start position:0% +buy this stuff are actually increasingly + + + align:start position:0% +buy this stuff are actually increasingly +companies so one thing we'll talk about + + align:start position:0% +companies so one thing we'll talk about + + + align:start position:0% +companies so one thing we'll talk about +a little bit at the end of the lecture + + align:start position:0% +a little bit at the end of the lecture + + + align:start position:0% +a little bit at the end of the lecture +is how sometimes companies are now + + align:start position:0% +is how sometimes companies are now + + + align:start position:0% +is how sometimes companies are now +taking cyber security into their own + + align:start position:0% +taking cyber security into their own + + + align:start position:0% +taking cyber security into their own +hands and sometimes doing what's called + + align:start position:0% +hands and sometimes doing what's called + + + align:start position:0% +hands and sometimes doing what's called +hack backs right so without getting the + + align:start position:0% +hack backs right so without getting the + + + align:start position:0% +hack backs right so without getting the +government involved companies that are + + align:start position:0% +government involved companies that are + + + align:start position:0% +government involved companies that are +attacked by cyber criminals will + + align:start position:0% +attacked by cyber criminals will + + + align:start position:0% +attacked by cyber criminals will +sometimes go back and explicitly try to + + align:start position:0% +sometimes go back and explicitly try to + + + align:start position:0% +sometimes go back and explicitly try to +take out the people who tried to steal + + align:start position:0% +take out the people who tried to steal + + + align:start position:0% +take out the people who tried to steal +their intellectual property and they + + align:start position:0% +their intellectual property and they + + + align:start position:0% +their intellectual property and they +sort of used some very inventive legal + + align:start position:0% +sort of used some very inventive legal + + + align:start position:0% +sort of used some very inventive legal +arguments to justify this and so far + + align:start position:0% +arguments to justify this and so far + + + align:start position:0% +arguments to justify this and so far +it's actually been fairly successful so + + align:start position:0% +it's actually been fairly successful so + + + align:start position:0% +it's actually been fairly successful so +this is an interesting aspect of cyber + + align:start position:0% +this is an interesting aspect of cyber + + + align:start position:0% +this is an interesting aspect of cyber +warfare yeah how that how is what + + align:start position:0% +warfare yeah how that how is what + + + align:start position:0% +warfare yeah how that how is what +how well so I mean information wants to + + align:start position:0% +how well so I mean information wants to + + + align:start position:0% +how well so I mean information wants to +be free dude right so I mean if you if + + align:start position:0% +be free dude right so I mean if you if + + + align:start position:0% +be free dude right so I mean if you if +you think about uh stuff like this for + + align:start position:0% +you think about uh stuff like this for + + + align:start position:0% +you think about uh stuff like this for +example like just telling you stuff + + align:start position:0% +example like just telling you stuff + + + align:start position:0% +example like just telling you stuff +isn't necessarily illegal I mean it gets + + align:start position:0% +isn't necessarily illegal I mean it gets + + + align:start position:0% +isn't necessarily illegal I mean it gets +a little bit gray right but for example + + align:start position:0% +a little bit gray right but for example + + + align:start position:0% +a little bit gray right but for example +if I tell you that look over there + + align:start position:0% +if I tell you that look over there + + + align:start position:0% +if I tell you that look over there +there's a house and the lock doesn't + + align:start position:0% +there's a house and the lock doesn't + + + align:start position:0% +there's a house and the lock doesn't +work on that + + align:start position:0% +work on that + + + align:start position:0% +work on that +door + + align:start position:0% +door + + + align:start position:0% +door +can I have 20 bucks right like that's + + align:start position:0% +can I have 20 bucks right like that's + + + align:start position:0% +can I have 20 bucks right like that's +not necessarily illegal right and so as + + align:start position:0% +not necessarily illegal right and so as + + + align:start position:0% +not necessarily illegal right and so as +it turns out these companies have like + + align:start position:0% +it turns out these companies have like + + + align:start position:0% +it turns out these companies have like +hordes of lawyers that look into things + + align:start position:0% +hordes of lawyers that look into things + + + align:start position:0% +hordes of lawyers that look into things +like this right but in many cases I mean + + align:start position:0% +like this right but in many cases I mean + + + align:start position:0% +like this right but in many cases I mean +if you think about it like you can like + + align:start position:0% +if you think about it like you can like + + + align:start position:0% +if you think about it like you can like +you can search for stuff on the internet + + align:start position:0% +you can search for stuff on the internet + + + align:start position:0% +you can search for stuff on the internet +and go to websites that tell you things + + align:start position:0% +and go to websites that tell you things + + + align:start position:0% +and go to websites that tell you things +like how to build bombs for example like + + align:start position:0% +like how to build bombs for example like + + + align:start position:0% +like how to build bombs for example like +just posting that information typically + + align:start position:0% +just posting that information typically + + + align:start position:0% +just posting that information typically +is not illegal right because you're just + + align:start position:0% +is not illegal right because you're just + + + align:start position:0% +is not illegal right because you're just +you're just learning like what if I'm a + + align:start position:0% +you're just learning like what if I'm a + + + align:start position:0% +you're just learning like what if I'm a +chemist for example or you something + + align:start position:0% +chemist for example or you something + + + align:start position:0% +chemist for example or you something +like this right so a lot of times just + + align:start position:0% +like this right so a lot of times just + + + align:start position:0% +like this right so a lot of times just +giving someone knowledge is not + + align:start position:0% +giving someone knowledge is not + + + align:start position:0% +giving someone knowledge is not +necessarily uh but you're right that + + align:start position:0% +necessarily uh but you're right that + + + align:start position:0% +necessarily uh but you're right that +there's some gray areas here and as + + align:start position:0% +there's some gray areas here and as + + + align:start position:0% +there's some gray areas here and as +we'll talk about with some of these hack + + align:start position:0% +we'll talk about with some of these hack + + + align:start position:0% +we'll talk about with some of these hack +backs for example it's not always clear + + align:start position:0% +backs for example it's not always clear + + + align:start position:0% +backs for example it's not always clear +for example if I am a bank I'm not a + + align:start position:0% +for example if I am a bank I'm not a + + + align:start position:0% +for example if I am a bank I'm not a +government but I'm a bank I get hacked + + align:start position:0% +government but I'm a bank I get hacked + + + align:start position:0% +government but I'm a bank I get hacked +it's not always clear that I actually + + align:start position:0% +it's not always clear that I actually + + + align:start position:0% +it's not always clear that I actually +have the legal authority to go back and + + align:start position:0% +have the legal authority to go back and + + + align:start position:0% +have the legal authority to go back and +let's they try to shut down a bot net or + + align:start position:0% +let's they try to shut down a bot net or + + + align:start position:0% +let's they try to shut down a bot net or +things like that companies have done + + align:start position:0% +things like that companies have done + + + align:start position:0% +things like that companies have done +stuff like that but I think this is an + + align:start position:0% +stuff like that but I think this is an + + + align:start position:0% +stuff like that but I think this is an +example where uh sort of the law is + + align:start position:0% +example where uh sort of the law is + + + align:start position:0% +example where uh sort of the law is +lagging behind uh what do you practice I + + align:start position:0% +lagging behind uh what do you practice I + + + align:start position:0% +lagging behind uh what do you practice I +guess and so people have used things + + align:start position:0% +guess and so people have used things + + + align:start position:0% +guess and so people have used things +like uh we'll use copyright infringement + + align:start position:0% +like uh we'll use copyright infringement + + + align:start position:0% +like uh we'll use copyright infringement +law to attack bot as a company because + + align:start position:0% +law to attack bot as a company because + + + align:start position:0% +law to attack bot as a company because +they're selling legal Goods of ours so + + align:start position:0% +they're selling legal Goods of ours so + + + align:start position:0% +they're selling legal Goods of ours so +we'll use IP infringement like this is + + align:start position:0% +we'll use IP infringement like this is + + + align:start position:0% +we'll use IP infringement like this is +probably not what Thomas Jefferson was + + align:start position:0% +probably not what Thomas Jefferson was + + + align:start position:0% +probably not what Thomas Jefferson was +thinking when he was thinking about how + + align:start position:0% +thinking when he was thinking about how + + + align:start position:0% +thinking when he was thinking about how +these laws work uh so it's it's a little + + align:start position:0% +these laws work uh so it's it's a little + + + align:start position:0% +these laws work uh so it's it's a little +bit of a cat and mouse game so we'll + + align:start position:0% +bit of a cat and mouse game so we'll + + + align:start position:0% +bit of a cat and mouse game so we'll +deal with a little bit of that later in + + align:start position:0% +deal with a little bit of that later in + + + align:start position:0% +deal with a little bit of that later in +the lecture um all right so yeah so this + + align:start position:0% +the lecture um all right so yeah so this + + + align:start position:0% +the lecture um all right so yeah so this +is very interesting um and so basically + + align:start position:0% +is very interesting um and so basically + + + align:start position:0% +is very interesting um and so basically +what this all means is that there is + + align:start position:0% +what this all means is that there is + + + align:start position:0% +what this all means is that there is +this um there's this + + align:start position:0% + + + + align:start position:0% + +Marketplace for all kinds of uh + + align:start position:0% +Marketplace for all kinds of uh + + + align:start position:0% +Marketplace for all kinds of uh +computational resources that you might + + align:start position:0% +computational resources that you might + + + align:start position:0% +computational resources that you might +use uh as someone who wants to launch a + + align:start position:0% +use uh as someone who wants to launch a + + + align:start position:0% +use uh as someone who wants to launch a +tax so for example there's a Marketplace + + align:start position:0% +tax so for example there's a Marketplace + + + align:start position:0% +tax so for example there's a Marketplace +for uh + + align:start position:0% +for uh + + + align:start position:0% +for uh +compromised uh + + align:start position:0% +compromised uh + + + align:start position:0% +compromised uh +systems so for example you can go to the + + align:start position:0% +systems so for example you can go to the + + + align:start position:0% +systems so for example you can go to the +darker places of the internet you can + + align:start position:0% +darker places of the internet you can + + + align:start position:0% +darker places of the internet you can +purchase entire compromised machines + + align:start position:0% +purchase entire compromised machines + + + align:start position:0% +purchase entire compromised machines +right that might be part of a botnet uh + + align:start position:0% +right that might be part of a botnet uh + + + align:start position:0% +right that might be part of a botnet uh +you can actually buy access to a + + align:start position:0% +you can actually buy access to a + + + align:start position:0% +you can actually buy access to a +compromised website for example you + + align:start position:0% +compromised website for example you + + + align:start position:0% +compromised website for example you +might use that website to post spam or + + align:start position:0% +might use that website to post spam or + + + align:start position:0% +might use that website to post spam or +put up you know evil links or things + + align:start position:0% +put up you know evil links or things + + + align:start position:0% +put up you know evil links or things +like that you can also get access access + + align:start position:0% +like that you can also get access access + + + align:start position:0% +like that you can also get access access +to compromised email accounts like Gmail + + align:start position:0% +to compromised email accounts like Gmail + + + align:start position:0% +to compromised email accounts like Gmail +or Yahoo accounts as we'll talk later + + align:start position:0% +or Yahoo accounts as we'll talk later + + + align:start position:0% +or Yahoo accounts as we'll talk later +those things are very very powerful for + + align:start position:0% +those things are very very powerful for + + + align:start position:0% +those things are very very powerful for +an attacker um and you may also just buy + + align:start position:0% +an attacker um and you may also just buy + + + align:start position:0% +an attacker um and you may also just buy +sort of like a subscription service for + + align:start position:0% +sort of like a subscription service for + + + align:start position:0% +sort of like a subscription service for +a botnet you'll just have this thing + + align:start position:0% +a botnet you'll just have this thing + + + align:start position:0% +a botnet you'll just have this thing +laying around you can use it to send + + align:start position:0% +laying around you can use it to send + + + align:start position:0% +laying around you can use it to send +denial of service attacks or things like + + align:start position:0% +denial of service attacks or things like + + + align:start position:0% +denial of service attacks or things like +that um so there's a Marketplace for + + align:start position:0% +that um so there's a Marketplace for + + + align:start position:0% +that um so there's a Marketplace for +that there's a Marketplace for um + + align:start position:0% +that there's a Marketplace for um + + + align:start position:0% +that there's a Marketplace for um +tools so you can get as an attacker off + + align:start position:0% +tools so you can get as an attacker off + + + align:start position:0% +tools so you can get as an attacker off +the shelf malware kits for example um + + align:start position:0% +the shelf malware kits for example um + + + align:start position:0% +the shelf malware kits for example um +you can uh use perhaps you know arms + + align:start position:0% +you can uh use perhaps you know arms + + + align:start position:0% +you can uh use perhaps you know arms +dealers like this to get access to zero + + align:start position:0% +dealers like this to get access to zero + + + align:start position:0% +dealers like this to get access to zero +day exploits so you can write your own + + align:start position:0% +day exploits so you can write your own + + + align:start position:0% +day exploits so you can write your own +malware so on and so forth um and + + align:start position:0% +malware so on and so forth um and + + + align:start position:0% +malware so on and so forth um and +there's also a big Marketplace for uh + + align:start position:0% +there's also a big Marketplace for uh + + + align:start position:0% +there's also a big Marketplace for uh +stolen uh user + + align:start position:0% +stolen uh user + + + align:start position:0% +stolen uh user +information so this is stuff like Social + + align:start position:0% +information so this is stuff like Social + + + align:start position:0% +information so this is stuff like Social +Security numbers credit card numbers uh + + align:start position:0% +Security numbers credit card numbers uh + + + align:start position:0% +Security numbers credit card numbers uh +email addresses so on and so forth so + + align:start position:0% +email addresses so on and so forth so + + + align:start position:0% +email addresses so on and so forth so +it's all out there on the internet if + + align:start position:0% +it's all out there on the internet if + + + align:start position:0% +it's all out there on the internet if +you're just willing to look for and so + + align:start position:0% +you're just willing to look for and so + + + align:start position:0% +you're just willing to look for and so +the paper that we're going to uh look at + + align:start position:0% +the paper that we're going to uh look at + + + align:start position:0% +the paper that we're going to uh look at +today uh basically focused on one aspect + + align:start position:0% +today uh basically focused on one aspect + + + align:start position:0% +today uh basically focused on one aspect +of this which is the spam + + align:start position:0% +of this which is the spam + + + align:start position:0% +of this which is the spam +ecosystem + + align:start position:0% +ecosystem + + + align:start position:0% +ecosystem +and so in particular they look at the + + align:start position:0% +and so in particular they look at the + + + align:start position:0% +and so in particular they look at the +sale of uh Pharmaceuticals of knockoff + + align:start position:0% +sale of uh Pharmaceuticals of knockoff + + + align:start position:0% +sale of uh Pharmaceuticals of knockoff +goods and software and so they basically + + align:start position:0% +goods and software and so they basically + + + align:start position:0% +goods and software and so they basically +break this spam ecosystem into uh three + + align:start position:0% +break this spam ecosystem into uh three + + + align:start position:0% +break this spam ecosystem into uh three +parts so they break it into uh + + align:start position:0% +parts so they break it into uh + + + align:start position:0% +parts so they break it into uh +advertising so this is the process of + + align:start position:0% +advertising so this is the process of + + + align:start position:0% +advertising so this is the process of +somehow getting a user to click on a + + align:start position:0% +somehow getting a user to click on a + + + align:start position:0% +somehow getting a user to click on a +Spam link somehow uh and then once + + align:start position:0% +Spam link somehow uh and then once + + + align:start position:0% +Spam link somehow uh and then once +they've done that there's this issue of + + align:start position:0% +they've done that there's this issue of + + + align:start position:0% +they've done that there's this issue of +uh click support + + align:start position:0% +uh click support + + + align:start position:0% +uh click support +so this is the uh notion that once the + + align:start position:0% +so this is the uh notion that once the + + + align:start position:0% +so this is the uh notion that once the +user clicks the link there has to be + + align:start position:0% +user clicks the link there has to be + + + align:start position:0% +user clicks the link there has to be +some type of web server DNS + + align:start position:0% +some type of web server DNS + + + align:start position:0% +some type of web server DNS +infrastructure so on and so forth on the + + align:start position:0% +infrastructure so on and so forth on the + + + align:start position:0% +infrastructure so on and so forth on the +back end that actually presents the spam + + align:start position:0% +back end that actually presents the spam + + + align:start position:0% +back end that actually presents the spam +website that the user goes to and then + + align:start position:0% +website that the user goes to and then + + + align:start position:0% +website that the user goes to and then +the final part is uh + + align:start position:0% + + + + align:start position:0% + +realization so this is actually allowing + + align:start position:0% +realization so this is actually allowing + + + align:start position:0% +realization so this is actually allowing +the user to uh say that they want to buy + + align:start position:0% +the user to uh say that they want to buy + + + align:start position:0% +the user to uh say that they want to buy +something the user sends money to the + + align:start position:0% +something the user sends money to the + + + align:start position:0% +something the user sends money to the +spammers and the user is going to get + + align:start position:0% +spammers and the user is going to get + + + align:start position:0% +spammers and the user is going to get +some product uh back from the back end + + align:start position:0% +some product uh back from the back end + + + align:start position:0% +some product uh back from the back end +and so this is you know where all of the + + align:start position:0% +and so this is you know where all of the + + + align:start position:0% +and so this is you know where all of the +uh money makes place and so a lot of + + align:start position:0% +uh money makes place and so a lot of + + + align:start position:0% +uh money makes place and so a lot of +this stuff is actually + + align:start position:0% +this stuff is actually + + + align:start position:0% +this stuff is actually +outsourced to what the uh paper calls + + align:start position:0% +outsourced to what the uh paper calls + + + align:start position:0% +outsourced to what the uh paper calls +these affiliate + + align:start position:0% +these affiliate + + + align:start position:0% +these affiliate +programs and so you can think of these + + align:start position:0% +programs and so you can think of these + + + align:start position:0% +programs and so you can think of these +uh affiliate programs as essentially + + align:start position:0% +uh affiliate programs as essentially + + + align:start position:0% +uh affiliate programs as essentially +doing a lot of the the backend grunt + + align:start position:0% +doing a lot of the the backend grunt + + + align:start position:0% +doing a lot of the the backend grunt +work of talking to Banks and Visa + + align:start position:0% +work of talking to Banks and Visa + + + align:start position:0% +work of talking to Banks and Visa +Mastercard and things like this and so a + + align:start position:0% +Mastercard and things like this and so a + + + align:start position:0% +Mastercard and things like this and so a +lot of times the the spammers they don't + + align:start position:0% +lot of times the the spammers they don't + + + align:start position:0% +lot of times the the spammers they don't +want to deal with that stuff they just + + align:start position:0% +want to deal with that stuff they just + + + align:start position:0% +want to deal with that stuff they just +want to sort of uh create the links and + + align:start position:0% +want to sort of uh create the links and + + + align:start position:0% +want to sort of uh create the links and +sort of do the you can think of it as + + align:start position:0% +sort of do the you can think of it as + + + align:start position:0% +sort of do the you can think of it as +like the advertising component and so a + + align:start position:0% +like the advertising component and so a + + + align:start position:0% +like the advertising component and so a +lot of times the spammers themselves + + align:start position:0% +lot of times the spammers themselves + + + align:start position:0% +lot of times the spammers themselves +they will work on a commission so they + + align:start position:0% +they will work on a commission so they + + + align:start position:0% +they will work on a commission so they +will get you know let's say anywhere + + align:start position:0% +will get you know let's say anywhere + + + align:start position:0% +will get you know let's say anywhere +between uh 30% to maybe + + align:start position:0% +between uh 30% to maybe + + + align:start position:0% +between uh 30% to maybe +50% of uh the final sale that they + + align:start position:0% +50% of uh the final sale that they + + + align:start position:0% +50% of uh the final sale that they +deliver to one of these uh backend + + align:start position:0% +deliver to one of these uh backend + + + align:start position:0% +deliver to one of these uh backend +Affiliates so does that all make sense + + align:start position:0% +Affiliates so does that all make sense + + + align:start position:0% +Affiliates so does that all make sense +at a high + + align:start position:0% +at a high + + + align:start position:0% +at a high +level okay so what we'll do is we'll + + align:start position:0% +level okay so what we'll do is we'll + + + align:start position:0% +level okay so what we'll do is we'll +look at uh sort of each component of + + align:start position:0% +look at uh sort of each component of + + + align:start position:0% +look at uh sort of each component of +this uh this this spam trajectory and + + align:start position:0% +this uh this this spam trajectory and + + + align:start position:0% +this uh this this spam trajectory and +then see how it works and then maybe + + align:start position:0% +then see how it works and then maybe + + + align:start position:0% +then see how it works and then maybe +think about how we'd be able to uh shut + + align:start position:0% +think about how we'd be able to uh shut + + + align:start position:0% +think about how we'd be able to uh shut +down spammers at different levels of + + align:start position:0% +down spammers at different levels of + + + align:start position:0% +down spammers at different levels of +this uh + + align:start position:0% +this uh + + + align:start position:0% +this uh +economy so the first thing we'll look at + + align:start position:0% +economy so the first thing we'll look at + + + align:start position:0% +economy so the first thing we'll look at +is uh the advertising + + align:start position:0% + + + + align:start position:0% + +component and so like I mentioned the + + align:start position:0% +component and so like I mentioned the + + + align:start position:0% +component and so like I mentioned the +basic idea of advertising + + align:start position:0% +basic idea of advertising + + + align:start position:0% +basic idea of advertising +is how do you uh get the + + align:start position:0% +is how do you uh get the + + + align:start position:0% +is how do you uh get the +user to click on a + + align:start position:0% + + + + align:start position:0% + +link that's the primary question we'll + + align:start position:0% +link that's the primary question we'll + + + align:start position:0% +link that's the primary question we'll +be concerned with here and so you know + + align:start position:0% +be concerned with here and so you know + + + align:start position:0% +be concerned with here and so you know +the typical thing as we all know is + + align:start position:0% +the typical thing as we all know is + + + align:start position:0% +the typical thing as we all know is +you're going to uh email spam although + + align:start position:0% +you're going to uh email spam although + + + align:start position:0% +you're going to uh email spam although +as we discussed at the beginning of + + align:start position:0% +as we discussed at the beginning of + + + align:start position:0% +as we discussed at the beginning of +lecture people are also starting to use + + align:start position:0% +lecture people are also starting to use + + + align:start position:0% +lecture people are also starting to use +text messages and some of these other + + align:start position:0% +text messages and some of these other + + + align:start position:0% +text messages and some of these other +forms of of Media communication uh you + + align:start position:0% +forms of of Media communication uh you + + + align:start position:0% +forms of of Media communication uh you +can also Imagine maybe here we're going + + align:start position:0% +can also Imagine maybe here we're going + + + align:start position:0% +can also Imagine maybe here we're going +to start using social networks as well + + align:start position:0% +to start using social networks as well + + + align:start position:0% +to start using social networks as well +so now when you go to Facebook not only + + align:start position:0% +so now when you go to Facebook not only + + + align:start position:0% +so now when you go to Facebook not only +you're polluted by your real friends + + align:start position:0% +you're polluted by your real friends + + + align:start position:0% +you're polluted by your real friends +content you're also polluted by spam + + align:start position:0% +content you're also polluted by spam + + + align:start position:0% +content you're also polluted by spam +messages too + + align:start position:0% +messages too + + + align:start position:0% +messages too +so this is about economics this + + align:start position:0% +so this is about economics this + + + align:start position:0% +so this is about economics this +discussion so one interesting question + + align:start position:0% +discussion so one interesting question + + + align:start position:0% +discussion so one interesting question +is how much does it cost to actually + + align:start position:0% +is how much does it cost to actually + + + align:start position:0% +is how much does it cost to actually +send out these spam messages and so as + + align:start position:0% +send out these spam messages and so as + + + align:start position:0% +send out these spam messages and so as +it turns out it is not very expensive at + + align:start position:0% +it turns out it is not very expensive at + + + align:start position:0% +it turns out it is not very expensive at +all so for about 60 bucks you can send + + align:start position:0% +all so for about 60 bucks you can send + + + align:start position:0% +all so for about 60 bucks you can send +uh a million span + + align:start position:0% + + + + align:start position:0% + +messages right so that's a super super a + + align:start position:0% +messages right so that's a super super a + + + align:start position:0% +messages right so that's a super super a +low cost and this cost is actually much + + align:start position:0% +low cost and this cost is actually much + + + align:start position:0% +low cost and this cost is actually much +lower uh if you're directly operating + + align:start position:0% +lower uh if you're directly operating + + + align:start position:0% +lower uh if you're directly operating +the botnet you can cut out the middleman + + align:start position:0% +the botnet you can cut out the middleman + + + align:start position:0% +the botnet you can cut out the middleman +right but even if you are are renting + + align:start position:0% +right but even if you are are renting + + + align:start position:0% +right but even if you are are renting +one of the botn Nets you know from one + + align:start position:0% +one of the botn Nets you know from one + + + align:start position:0% +one of the botn Nets you know from one +of these marketplaces this is still + + align:start position:0% +of these marketplaces this is still + + + align:start position:0% +of these marketplaces this is still +super super low uh many of those are + + align:start position:0% +super super low uh many of those are + + + align:start position:0% +super super low uh many of those are +actually effective as in they don't get + + align:start position:0% +actually effective as in they don't get + + + align:start position:0% +actually effective as in they don't get +filtered Ah that's a good question so + + align:start position:0% +filtered Ah that's a good question so + + + align:start position:0% +filtered Ah that's a good question so +that leads to my next point so so yeah + + align:start position:0% +that leads to my next point so so yeah + + + align:start position:0% +that leads to my next point so so yeah +so so this is you're sending a million + + align:start position:0% +so so this is you're sending a million + + + align:start position:0% +so so this is you're sending a million +spams but then they're going to get + + align:start position:0% +spams but then they're going to get + + + align:start position:0% +spams but then they're going to get +dropped at various points along the way + + align:start position:0% +dropped at various points along the way + + + align:start position:0% +dropped at various points along the way +they're going to caught in spam filters + + align:start position:0% +they're going to caught in spam filters + + + align:start position:0% +they're going to caught in spam filters +maybe people don't even uh they see it + + align:start position:0% +maybe people don't even uh they see it + + + align:start position:0% +maybe people don't even uh they see it +but they just delete it because they + + align:start position:0% +but they just delete it because they + + + align:start position:0% +but they just delete it because they +know that an email that has like $18 + + align:start position:0% +know that an email that has like $18 + + + align:start position:0% +know that an email that has like $18 +sign should just be deleted so if you + + align:start position:0% +sign should just be deleted so if you + + + align:start position:0% +sign should just be deleted so if you +look at the uh conver conversion rate I + + align:start position:0% +look at the uh conver conversion rate I + + + align:start position:0% +look at the uh conver conversion rate I +mean you'll see that the The Click rates + + align:start position:0% +mean you'll see that the The Click rates + + + align:start position:0% +mean you'll see that the The Click rates +are actually very + + align:start position:0% +are actually very + + + align:start position:0% +are actually very +low because of things like spam filters + + align:start position:0% +low because of things like spam filters + + + align:start position:0% +low because of things like spam filters +and and stuff like that and also users + + align:start position:0% +and and stuff like that and also users + + + align:start position:0% +and and stuff like that and also users +are sort of many users are trained to + + align:start position:0% +are sort of many users are trained to + + + align:start position:0% +are sort of many users are trained to +avoid these things so these cck click + + align:start position:0% +avoid these things so these cck click + + + align:start position:0% +avoid these things so these cck click +rates are low um and this is why sending + + align:start position:0% +rates are low um and this is why sending + + + align:start position:0% +rates are low um and this is why sending +spam has to be super super cheap right + + align:start position:0% +spam has to be super super cheap right + + + align:start position:0% +spam has to be super super cheap right +because you will not get a lot of + + align:start position:0% +because you will not get a lot of + + + align:start position:0% +because you will not get a lot of +conversions so for example there have + + align:start position:0% +conversions so for example there have + + + align:start position:0% +conversions so for example there have +been some empirical studies that looked + + align:start position:0% +been some empirical studies that looked + + + align:start position:0% +been some empirical studies that looked +at these click rates and so uh one study + + align:start position:0% +at these click rates and so uh one study + + + align:start position:0% +at these click rates and so uh one study +found that they looked at 350 + + align:start position:0% +found that they looked at 350 + + + align:start position:0% +found that they looked at 350 +million uh spam + + align:start position:0% +million uh spam + + + align:start position:0% +million uh spam +messages and they found that out of + + align:start position:0% +messages and they found that out of + + + align:start position:0% +messages and they found that out of +those 350 million messages uh there was + + align:start position:0% +those 350 million messages uh there was + + + align:start position:0% +those 350 million messages uh there was +only about uh 10,000 clicks on those + + align:start position:0% +only about uh 10,000 clicks on those + + + align:start position:0% +only about uh 10,000 clicks on those +messages okay so there's a massive drop + + align:start position:0% +messages okay so there's a massive drop + + + align:start position:0% +messages okay so there's a massive drop +off here and then out of these 10,000 + + align:start position:0% +off here and then out of these 10,000 + + + align:start position:0% +off here and then out of these 10,000 +clicks there were only 28 purchase + + align:start position:0% + + + + align:start position:0% + +attempts right so that's super super low + + align:start position:0% +attempts right so that's super super low + + + align:start position:0% +attempts right so that's super super low +and so that's why it's extremely + + align:start position:0% +and so that's why it's extremely + + + align:start position:0% +and so that's why it's extremely +important for this entire ecosystem to + + align:start position:0% +important for this entire ecosystem to + + + align:start position:0% +important for this entire ecosystem to +be very cheap from the perspective of + + align:start position:0% +be very cheap from the perspective of + + + align:start position:0% +be very cheap from the perspective of +the spammers because I mean look at + + align:start position:0% +the spammers because I mean look at + + + align:start position:0% +the spammers because I mean look at +these drop offs here I mean these are + + align:start position:0% +these drop offs here I mean these are + + + align:start position:0% +these drop offs here I mean these are +like multiple orders of magnitude right + + align:start position:0% +like multiple orders of magnitude right + + + align:start position:0% +like multiple orders of magnitude right +and so that's why you know one might + + align:start position:0% +and so that's why you know one might + + + align:start position:0% +and so that's why you know one might +hope that at least in theory if we could + + align:start position:0% +hope that at least in theory if we could + + + align:start position:0% +hope that at least in theory if we could +sque like for example if we could drive + + align:start position:0% +sque like for example if we could drive + + + align:start position:0% +sque like for example if we could drive +you know this number maybe just 10 bucks + + align:start position:0% +you know this number maybe just 10 bucks + + + align:start position:0% +you know this number maybe just 10 bucks +maybe that has like some catastrophic + + align:start position:0% +maybe that has like some catastrophic + + + align:start position:0% +maybe that has like some catastrophic +knockdown effect on how profitable this + + align:start position:0% +knockdown effect on how profitable this + + + align:start position:0% +knockdown effect on how profitable this +stuff is uh so anyway so it's very it's + + align:start position:0% +stuff is uh so anyway so it's very it's + + + align:start position:0% +stuff is uh so anyway so it's very it's +very important uh for the spammers that + + align:start position:0% +very important uh for the spammers that + + + align:start position:0% +very important uh for the spammers that +everything be as cheap as possible so + + align:start position:0% +everything be as cheap as possible so + + + align:start position:0% +everything be as cheap as possible so +those clicks uh again like are they so + + align:start position:0% +those clicks uh again like are they so + + + align:start position:0% +those clicks uh again like are they so +how many of those 350 million emails + + align:start position:0% +how many of those 350 million emails + + + align:start position:0% +how many of those 350 million emails +were filtered out of the inbox I'm + + align:start position:0% +were filtered out of the inbox I'm + + + align:start position:0% +were filtered out of the inbox I'm +trying to get a sense how many emails + + align:start position:0% +trying to get a sense how many emails + + + align:start position:0% +trying to get a sense how many emails +out of how many emails those clicks were + + align:start position:0% +out of how many emails those clicks were + + + align:start position:0% +out of how many emails those clicks were +out of to GA how effective span + + align:start position:0% +out of to GA how effective span + + + align:start position:0% +out of to GA how effective span +filtering is versus how silly us humans + + align:start position:0% +filtering is versus how silly us humans + + + align:start position:0% +filtering is versus how silly us humans +are yeah that I'm I'm not actually sure + + align:start position:0% +are yeah that I'm I'm not actually sure + + + align:start position:0% +are yeah that I'm I'm not actually sure +that's a good question uh so uh I was + + align:start position:0% +that's a good question uh so uh I was + + + align:start position:0% +that's a good question uh so uh I was +just listening to a talk by Jeff vuler + + align:start position:0% +just listening to a talk by Jeff vuler + + + align:start position:0% +just listening to a talk by Jeff vuler +uh on Friday about this stuff and he + + align:start position:0% +uh on Friday about this stuff and he + + + align:start position:0% +uh on Friday about this stuff and he +says that uh on the order of 20 or to + + align:start position:0% +says that uh on the order of 20 or to + + + align:start position:0% +says that uh on the order of 20 or to +40% of clicks going to uh one of these + + align:start position:0% +40% of clicks going to uh one of these + + + align:start position:0% +40% of clicks going to uh one of these +websites actually goes from a user spam + + align:start position:0% +websites actually goes from a user spam + + + align:start position:0% +websites actually goes from a user spam +folder so users go in their spam folder + + align:start position:0% +folder so users go in their spam folder + + + align:start position:0% +folder so users go in their spam folder +looking for this stuff and they click on + + align:start position:0% +looking for this stuff and they click on + + + align:start position:0% +looking for this stuff and they click on +it so presumably there's a class of + + align:start position:0% +it so presumably there's a class of + + + align:start position:0% +it so presumably there's a class of +customers that are looking for this and + + align:start position:0% +customers that are looking for this and + + + align:start position:0% +customers that are looking for this and +if they're looking for it they're oh + + align:start position:0% +if they're looking for it they're oh + + + align:start position:0% +if they're looking for it they're oh +yeah I'll just go to my stamp folder and + + align:start position:0% +yeah I'll just go to my stamp folder and + + + align:start position:0% +yeah I'll just go to my stamp folder and +find where to buy this so it's not clear + + align:start position:0% +find where to buy this so it's not clear + + + align:start position:0% +find where to buy this so it's not clear +that things going into the SP folder are + + align:start position:0% +that things going into the SP folder are + + + align:start position:0% +that things going into the SP folder are +getting zero clicks yeah I've heard + + align:start position:0% +getting zero clicks yeah I've heard + + + align:start position:0% +getting zero clicks yeah I've heard +anecdotal reports of that too that some + + align:start position:0% +anecdotal reports of that too that some + + + align:start position:0% +anecdotal reports of that too that some +people they I mean even for legitimate + + align:start position:0% +people they I mean even for legitimate + + + align:start position:0% +people they I mean even for legitimate +emails they'll market as spam just so + + align:start position:0% +emails they'll market as spam just so + + + align:start position:0% +emails they'll market as spam just so +like if there's a a shoulder surface + + align:start position:0% +like if there's a a shoulder surface + + + align:start position:0% +like if there's a a shoulder surface +like at work who's seeing them go to + + align:start position:0% +like at work who's seeing them go to + + + align:start position:0% +like at work who's seeing them go to +Gmail let's say they won't come in and + + align:start position:0% +Gmail let's say they won't come in and + + + align:start position:0% +Gmail let's say they won't come in and +see that you've subscribed to you know + + align:start position:0% +see that you've subscribed to you know + + + align:start position:0% +see that you've subscribed to you know +whatever and then they can secretly go + + align:start position:0% +whatever and then they can secretly go + + + align:start position:0% +whatever and then they can secretly go +into the spam folder they know it's not + + align:start position:0% +into the spam folder they know it's not + + + align:start position:0% +into the spam folder they know it's not +deleted and look at this stuff and + + align:start position:0% +deleted and look at this stuff and + + + align:start position:0% +deleted and look at this stuff and +there's this is actually a really + + align:start position:0% +there's this is actually a really + + + align:start position:0% +there's this is actually a really +interesting point so there's this whole + + align:start position:0% +interesting point so there's this whole + + + align:start position:0% +interesting point so there's this whole +psychology of who it is that actually + + align:start position:0% +psychology of who it is that actually + + + align:start position:0% +psychology of who it is that actually +clicks on these links and so I think one + + align:start position:0% +clicks on these links and so I think one + + + align:start position:0% +clicks on these links and so I think one +of the papers that I we linked to in the + + align:start position:0% +of the papers that I we linked to in the + + + align:start position:0% +of the papers that I we linked to in the +lecture notes talks about why do these + + align:start position:0% +lecture notes talks about why do these + + + align:start position:0% +lecture notes talks about why do these +Nigerian scams still work right because + + align:start position:0% +Nigerian scams still work right because + + + align:start position:0% +Nigerian scams still work right because +you'd think that anyone who basically + + align:start position:0% +you'd think that anyone who basically + + + align:start position:0% +you'd think that anyone who basically +like you know has either Common Sense + + align:start position:0% +like you know has either Common Sense + + + align:start position:0% +like you know has either Common Sense +himself or a friend who has Common Sense + + align:start position:0% +himself or a friend who has Common Sense + + + align:start position:0% +himself or a friend who has Common Sense +would never click on one of these + + align:start position:0% +would never click on one of these + + + align:start position:0% +would never click on one of these +Nigerian email scams right but one of + + align:start position:0% +Nigerian email scams right but one of + + + align:start position:0% +Nigerian email scams right but one of +the things that it turns out is that uh + + align:start position:0% +the things that it turns out is that uh + + + align:start position:0% +the things that it turns out is that uh +the Nigerian meme is actually useful for + + align:start position:0% +the Nigerian meme is actually useful for + + + align:start position:0% +the Nigerian meme is actually useful for +spammers to filter out idiots right so + + align:start position:0% +spammers to filter out idiots right so + + + align:start position:0% +spammers to filter out idiots right so +in other words if you are so foolish + + align:start position:0% +in other words if you are so foolish + + + align:start position:0% +in other words if you are so foolish +that you would still click on a Nigerian + + align:start position:0% +that you would still click on a Nigerian + + + align:start position:0% +that you would still click on a Nigerian +email then oh okay that must mean that + + align:start position:0% +email then oh okay that must mean that + + + align:start position:0% +email then oh okay that must mean that +you know you're going to be one of these + + align:start position:0% +you know you're going to be one of these + + + align:start position:0% +you know you're going to be one of these +conversion things here right so and when + + align:start position:0% +conversion things here right so and when + + + align:start position:0% +conversion things here right so and when +you think about it that's that's one of + + align:start position:0% +you think about it that's that's one of + + + align:start position:0% +you think about it that's that's one of +the key things that spammers need they + + align:start position:0% +the key things that spammers need they + + + align:start position:0% +the key things that spammers need they +need people who are sort of gullible + + align:start position:0% +need people who are sort of gullible + + + align:start position:0% +need people who are sort of gullible +enough or you know whatever idealistic + + align:start position:0% +enough or you know whatever idealistic + + + align:start position:0% +enough or you know whatever idealistic +enough to click through on these things + + align:start position:0% +enough to click through on these things + + + align:start position:0% +enough to click through on these things +so there's a whole sort of uh psychology + + align:start position:0% +so there's a whole sort of uh psychology + + + align:start position:0% +so there's a whole sort of uh psychology +behind this it's very interesting um so + + align:start position:0% +behind this it's very interesting um so + + + align:start position:0% +behind this it's very interesting um so +you purchases are they work yes that's a + + align:start position:0% +you purchases are they work yes that's a + + + align:start position:0% +you purchases are they work yes that's a +good question so it actually depends on + + align:start position:0% +good question so it actually depends on + + + align:start position:0% +good question so it actually depends on +um the type of thing that you're looking + + align:start position:0% +um the type of thing that you're looking + + + align:start position:0% +um the type of thing that you're looking +at right so a lot of these purchases are + + align:start position:0% +at right so a lot of these purchases are + + + align:start position:0% +at right so a lot of these purchases are +not actually super high in value right + + align:start position:0% +not actually super high in value right + + + align:start position:0% +not actually super high in value right +so if you think you know someone's + + align:start position:0% +so if you think you know someone's + + + align:start position:0% +so if you think you know someone's +buying herbal Viagra they're buying you + + align:start position:0% +buying herbal Viagra they're buying you + + + align:start position:0% +buying herbal Viagra they're buying you +know like a knockoff Windows license or + + align:start position:0% +know like a knockoff Windows license or + + + align:start position:0% +know like a knockoff Windows license or +things like that and in fact like a lot + + align:start position:0% +things like that and in fact like a lot + + + align:start position:0% +things like that and in fact like a lot +of times when they're buying these + + align:start position:0% +of times when they're buying these + + + align:start position:0% +of times when they're buying these +knockoff products presumably the price + + align:start position:0% +knockoff products presumably the price + + + align:start position:0% +knockoff products presumably the price +is lower than what they'd actually be in + + align:start position:0% +is lower than what they'd actually be in + + + align:start position:0% +is lower than what they'd actually be in +the real Market market right because + + align:start position:0% +the real Market market right because + + + align:start position:0% +the real Market market right because +otherwise you just go down to your local + + align:start position:0% +otherwise you just go down to your local + + + align:start position:0% +otherwise you just go down to your local +mall and buy these things so a lot of + + align:start position:0% +mall and buy these things so a lot of + + + align:start position:0% +mall and buy these things so a lot of +times these purchases you're actually + + align:start position:0% +times these purchases you're actually + + + align:start position:0% +times these purchases you're actually +making are you know less than $1,000 + + align:start position:0% +making are you know less than $1,000 + + + align:start position:0% +making are you know less than $1,000 +right and often times a lot less than + + align:start position:0% +right and often times a lot less than + + + align:start position:0% +right and often times a lot less than +that any other + + align:start position:0% +that any other + + + align:start position:0% +that any other +questions okay yeah so these conversion + + align:start position:0% +questions okay yeah so these conversion + + + align:start position:0% +questions okay yeah so these conversion +rates are super super low um so like I + + align:start position:0% +rates are super super low um so like I + + + align:start position:0% +rates are super super low um so like I +said one of the key things to do as a + + align:start position:0% +said one of the key things to do as a + + + align:start position:0% +said one of the key things to do as a +Defender is to try to uh basically uh + + align:start position:0% +Defender is to try to uh basically uh + + + align:start position:0% +Defender is to try to uh basically uh +make Spam more + + align:start position:0% + + + + align:start position:0% + +expensive for the spammer + + align:start position:0% +expensive for the spammer + + + align:start position:0% +expensive for the spammer +so there's a couple different ways you + + align:start position:0% +so there's a couple different ways you + + + align:start position:0% +so there's a couple different ways you +might think about doing that uh one way + + align:start position:0% +might think about doing that uh one way + + + align:start position:0% +might think about doing that uh one way +you might think about doing that uh our + + align:start position:0% +you might think about doing that uh our + + + align:start position:0% +you might think about doing that uh our +IP uh + + align:start position:0% +IP uh + + + align:start position:0% +IP uh +Blacklist so maybe isps or someone else + + align:start position:0% +Blacklist so maybe isps or someone else + + + align:start position:0% +Blacklist so maybe isps or someone else +basically collects this list of ips that + + align:start position:0% +basically collects this list of ips that + + + align:start position:0% +basically collects this list of ips that +are known to be bad right that are known + + align:start position:0% +are known to be bad right that are known + + + align:start position:0% +are known to be bad right that are known +to come from spammers and then we just + + align:start position:0% +to come from spammers and then we just + + + align:start position:0% +to come from spammers and then we just +don't let these people send traffic um + + align:start position:0% +don't let these people send traffic um + + + align:start position:0% +don't let these people send traffic um +so this kind of sort of used to work for + + align:start position:0% +so this kind of sort of used to work for + + + align:start position:0% +so this kind of sort of used to work for +a while but now um it's so much easier + + align:start position:0% +a while but now um it's so much easier + + + align:start position:0% +a while but now um it's so much easier +for the attackers to use techniques like + + align:start position:0% +for the attackers to use techniques like + + + align:start position:0% +for the attackers to use techniques like +DS redirection stuff like that that + + align:start position:0% +DS redirection stuff like that that + + + align:start position:0% +DS redirection stuff like that that +we'll talk about in a little bit this + + align:start position:0% +we'll talk about in a little bit this + + + align:start position:0% +we'll talk about in a little bit this +doesn't actually work out quite very + + align:start position:0% +doesn't actually work out quite very + + + align:start position:0% +doesn't actually work out quite very +well because now there's a much larger + + align:start position:0% +well because now there's a much larger + + + align:start position:0% +well because now there's a much larger +set of addresses that spammers can send + + align:start position:0% +set of addresses that spammers can send + + + align:start position:0% +set of addresses that spammers can send +uh spam from and they can also you know + + align:start position:0% +uh spam from and they can also you know + + + align:start position:0% +uh spam from and they can also you know +dynamically switch The Binding between + + align:start position:0% +dynamically switch The Binding between + + + align:start position:0% +dynamically switch The Binding between +um soort of let's say host names and web + + align:start position:0% +um soort of let's say host names and web + + + align:start position:0% +um soort of let's say host names and web +servers and all these types of things + + align:start position:0% +servers and all these types of things + + + align:start position:0% +servers and all these types of things +this doesn't work out so well um another + + align:start position:0% +this doesn't work out so well um another + + + align:start position:0% +this doesn't work out so well um another +idea that's been around for a long time + + align:start position:0% +idea that's been around for a long time + + + align:start position:0% +idea that's been around for a long time +is uh charging for email in some + + align:start position:0% +is uh charging for email in some + + + align:start position:0% +is uh charging for email in some +way so each email you send you have to + + align:start position:0% +way so each email you send you have to + + + align:start position:0% +way so each email you send you have to +pay some micro payment right and so that + + align:start position:0% +pay some micro payment right and so that + + + align:start position:0% +pay some micro payment right and so that +currency could be a couple different + + align:start position:0% +currency could be a couple different + + + align:start position:0% +currency could be a couple different +things so you might imagine that if I + + align:start position:0% +things so you might imagine that if I + + + align:start position:0% +things so you might imagine that if I +want to send you an email maybe I have + + align:start position:0% +want to send you an email maybe I have + + + align:start position:0% +want to send you an email maybe I have +to pay like a tenth of a tenth of a + + align:start position:0% +to pay like a tenth of a tenth of a + + + align:start position:0% +to pay like a tenth of a tenth of a +penny right and that's no big deal for + + align:start position:0% +penny right and that's no big deal for + + + align:start position:0% +penny right and that's no big deal for +me because you know I don't send that + + align:start position:0% +me because you know I don't send that + + + align:start position:0% +me because you know I don't send that +many emails a day but if you're a + + align:start position:0% +many emails a day but if you're a + + + align:start position:0% +many emails a day but if you're a +spammer trying to operate at these + + align:start position:0% +spammer trying to operate at these + + + align:start position:0% +spammer trying to operate at these +volumes then that quickly adds up right + + align:start position:0% +volumes then that quickly adds up right + + + align:start position:0% +volumes then that quickly adds up right +and that destroys their sort of value + + align:start position:0% +and that destroys their sort of value + + + align:start position:0% +and that destroys their sort of value +chain um another idea that people have + + align:start position:0% +chain um another idea that people have + + + align:start position:0% +chain um another idea that people have +had is what if you used um computation + + align:start position:0% +had is what if you used um computation + + + align:start position:0% +had is what if you used um computation +as a currency so this is the idea that + + align:start position:0% +as a currency so this is the idea that + + + align:start position:0% +as a currency so this is the idea that +before my email server will accept an + + align:start position:0% +before my email server will accept an + + + align:start position:0% +before my email server will accept an +email from me I have to solve solve some + + align:start position:0% +email from me I have to solve solve some + + + align:start position:0% +email from me I have to solve solve some +puzzle you know I have to do some math + + align:start position:0% +puzzle you know I have to do some math + + + align:start position:0% +puzzle you know I have to do some math +trick or something like that so once + + align:start position:0% +trick or something like that so once + + + align:start position:0% +trick or something like that so once +again that cuts down on the rate at + + align:start position:0% +again that cuts down on the rate at + + + align:start position:0% +again that cuts down on the rate at +which these bulk mailers can send uh + + align:start position:0% +which these bulk mailers can send uh + + + align:start position:0% +which these bulk mailers can send uh +messages and then also we're all + + align:start position:0% +messages and then also we're all + + + align:start position:0% +messages and then also we're all +familiar with captures too so this basic + + align:start position:0% +familiar with captures too so this basic + + + align:start position:0% +familiar with captures too so this basic +idea that I have to you know I look at + + align:start position:0% +idea that I have to you know I look at + + + align:start position:0% +idea that I have to you know I look at +some picture of nine animals and find + + align:start position:0% +some picture of nine animals and find + + + align:start position:0% +some picture of nine animals and find +the cat instead of the dog or you know + + align:start position:0% +the cat instead of the dog or you know + + + align:start position:0% +the cat instead of the dog or you know +type in some weird squiggly number that + + align:start position:0% +type in some weird squiggly number that + + + align:start position:0% +type in some weird squiggly number that +looks like a migraine or something like + + align:start position:0% +looks like a migraine or something like + + + align:start position:0% +looks like a migraine or something like +that so there have been all kinds of uh + + align:start position:0% +that so there have been all kinds of uh + + + align:start position:0% +that so there have been all kinds of uh +of of sort of ideas for charging for + + align:start position:0% +of of sort of ideas for charging for + + + align:start position:0% +of of sort of ideas for charging for +email to stop this kind of stuff from + + align:start position:0% +email to stop this kind of stuff from + + + align:start position:0% +email to stop this kind of stuff from +happening um + + align:start position:0% +happening um + + + align:start position:0% +happening um +so you know one of the classic problems + + align:start position:0% +so you know one of the classic problems + + + align:start position:0% +so you know one of the classic problems +though with all these schemes is that uh + + align:start position:0% +though with all these schemes is that uh + + + align:start position:0% +though with all these schemes is that uh +you know who's going to be the first one + + align:start position:0% +you know who's going to be the first one + + + align:start position:0% +you know who's going to be the first one +to implement it and if every if all the + + align:start position:0% +to implement it and if every if all the + + + align:start position:0% +to implement it and if every if all the +email providers don't move forward at + + align:start position:0% +email providers don't move forward at + + + align:start position:0% +email providers don't move forward at +the same time then of course spammers + + align:start position:0% +the same time then of course spammers + + + align:start position:0% +the same time then of course spammers +are just going to migrate to the email + + align:start position:0% +are just going to migrate to the email + + + align:start position:0% +are just going to migrate to the email +providers that don't require these + + align:start position:0% +providers that don't require these + + + align:start position:0% +providers that don't require these +techniques so there's been sort of a + + align:start position:0% +techniques so there's been sort of a + + + align:start position:0% +techniques so there's been sort of a +problem of how do we get everyone to + + align:start position:0% +problem of how do we get everyone to + + + align:start position:0% +problem of how do we get everyone to +upgrade in Mass um then there's sort of + + align:start position:0% +upgrade in Mass um then there's sort of + + + align:start position:0% +upgrade in Mass um then there's sort of +this issue of well what would happen if + + align:start position:0% +this issue of well what would happen if + + + align:start position:0% +this issue of well what would happen if +a user device is compromise so maybe you + + align:start position:0% +a user device is compromise so maybe you + + + align:start position:0% +a user device is compromise so maybe you +know if someone breaks into my Gmail + + align:start position:0% +know if someone breaks into my Gmail + + + align:start position:0% +know if someone breaks into my Gmail +account then maybe they're going to + + align:start position:0% +account then maybe they're going to + + + align:start position:0% +account then maybe they're going to +force me to pay you know you know 350 + + align:start position:0% +force me to pay you know you know 350 + + + align:start position:0% +force me to pay you know you know 350 +million micro payments which you know + + align:start position:0% +million micro payments which you know + + + align:start position:0% +million micro payments which you know +could individually bankrupt me right and + + align:start position:0% +could individually bankrupt me right and + + + align:start position:0% +could individually bankrupt me right and +so it's not quite clear that you know + + align:start position:0% +so it's not quite clear that you know + + + align:start position:0% +so it's not quite clear that you know +some of these schemes are ready for + + align:start position:0% +some of these schemes are ready for + + + align:start position:0% +some of these schemes are ready for +prime time but they do represent sort of + + align:start position:0% +prime time but they do represent sort of + + + align:start position:0% +prime time but they do represent sort of +an interesting thought experiment about + + align:start position:0% +an interesting thought experiment about + + + align:start position:0% +an interesting thought experiment about +how you might be able to stop some of + + align:start position:0% +how you might be able to stop some of + + + align:start position:0% +how you might be able to stop some of +this stuff from the center side so how + + align:start position:0% +this stuff from the center side so how + + + align:start position:0% +this stuff from the center side so how +they work with mailing lists where you + + align:start position:0% +they work with mailing lists where you + + + align:start position:0% +they work with mailing lists where you +have these Big M yeah so there's + + align:start position:0% +have these Big M yeah so there's + + + align:start position:0% +have these Big M yeah so there's +problems with that and like you know + + align:start position:0% +problems with that and like you know + + + align:start position:0% +problems with that and like you know +Mist aggregation and it's so it's very + + align:start position:0% +Mist aggregation and it's so it's very + + + align:start position:0% +Mist aggregation and it's so it's very +very tricky right because there are + + align:start position:0% +very tricky right because there are + + + align:start position:0% +very tricky right because there are +actually some bulk males that you do + + align:start position:0% +actually some bulk males that you do + + + align:start position:0% +actually some bulk males that you do +want to send I mean you might imagine + + align:start position:0% +want to send I mean you might imagine + + + align:start position:0% +want to send I mean you might imagine +having some heuristic where you look at + + align:start position:0% +having some heuristic where you look at + + + align:start position:0% +having some heuristic where you look at +the the size of the mailing list and + + align:start position:0% +the the size of the mailing list and + + + align:start position:0% +the the size of the mailing list and +maybe use sort of scale the payment + + align:start position:0% +maybe use sort of scale the payment + + + align:start position:0% +maybe use sort of scale the payment +according to that so for example maybe + + align:start position:0% +according to that so for example maybe + + + align:start position:0% +according to that so for example maybe +heris toally we think it's reasonable to + + align:start position:0% +heris toally we think it's reasonable to + + + align:start position:0% +heris toally we think it's reasonable to +send email to a th folks but not to like + + align:start position:0% +send email to a th folks but not to like + + + align:start position:0% +send email to a th folks but not to like +350 million folks or something like this + + align:start position:0% +350 million folks or something like this + + + align:start position:0% +350 million folks or something like this +right but you're right that there are a + + align:start position:0% +right but you're right that there are a + + + align:start position:0% +right but you're right that there are a +lot of practical implementation issues + + align:start position:0% +lot of practical implementation issues + + + align:start position:0% +lot of practical implementation issues +that come out with this kind of stuff um + + align:start position:0% +that come out with this kind of stuff um + + + align:start position:0% +that come out with this kind of stuff um +so what can + + align:start position:0% +so what can + + + align:start position:0% +so what can +the adversary do to get around some of + + align:start position:0% +the adversary do to get around some of + + + align:start position:0% +the adversary do to get around some of +this some of these types of defenses uh + + align:start position:0% +this some of these types of defenses uh + + + align:start position:0% +this some of these types of defenses uh +so they're basically uh three + + align:start position:0% +so they're basically uh three + + + align:start position:0% +so they're basically uh three +workarounds that adversaries might try + + align:start position:0% +workarounds that adversaries might try + + + align:start position:0% +workarounds that adversaries might try +so one thing they can do is just use + + align:start position:0% +so one thing they can do is just use + + + align:start position:0% +so one thing they can do is just use +botn Nets right because botn Nets uh + + align:start position:0% +botn Nets right because botn Nets uh + + + align:start position:0% +botn Nets right because botn Nets uh +have a lot of + + align:start position:0% +have a lot of + + + align:start position:0% +have a lot of +ips that the attacker can + + align:start position:0% +ips that the attacker can + + + align:start position:0% +ips that the attacker can +use and so for example even if someone + + align:start position:0% +use and so for example even if someone + + + align:start position:0% +use and so for example even if someone +were trying to do something like IP + + align:start position:0% +were trying to do something like IP + + + align:start position:0% +were trying to do something like IP +Blacklist then maybe the attacker can + + align:start position:0% +Blacklist then maybe the attacker can + + + align:start position:0% +Blacklist then maybe the attacker can +cycle through a bunch of ips in this + + align:start position:0% +cycle through a bunch of ips in this + + + align:start position:0% +cycle through a bunch of ips in this +botn net and maybe get around some of + + align:start position:0% +botn net and maybe get around some of + + + align:start position:0% +botn net and maybe get around some of +that uh Blacklist filtering uh they can + + align:start position:0% +that uh Blacklist filtering uh they can + + + align:start position:0% +that uh Blacklist filtering uh they can +also try to use um + + align:start position:0% +also try to use um + + + align:start position:0% +also try to use um +compromised uh web mail accounts to send + + align:start position:0% + + + + align:start position:0% + +spam and so the reason why these are + + align:start position:0% +spam and so the reason why these are + + + align:start position:0% +spam and so the reason why these are +super + + align:start position:0% +super + + + align:start position:0% +super +useful is because you know sites like + + align:start position:0% +useful is because you know sites like + + + align:start position:0% +useful is because you know sites like +Gmail or Yahoo or Hotmail those Services + + align:start position:0% +Gmail or Yahoo or Hotmail those Services + + + align:start position:0% +Gmail or Yahoo or Hotmail those Services +can't be can't be blacklisted right + + align:start position:0% +can't be can't be blacklisted right + + + align:start position:0% +can't be can't be blacklisted right +because they're super super powerful so + + align:start position:0% +because they're super super powerful so + + + align:start position:0% +because they're super super powerful so +if you blacklisted the entire service + + align:start position:0% +if you blacklisted the entire service + + + align:start position:0% +if you blacklisted the entire service +then you're probably going to shut down + + align:start position:0% +then you're probably going to shut down + + + align:start position:0% +then you're probably going to shut down +service for you know tens of millions of + + align:start position:0% +service for you know tens of millions of + + + align:start position:0% +service for you know tens of millions of +users now of course uh these Individual + + align:start position:0% +users now of course uh these Individual + + + align:start position:0% +users now of course uh these Individual +Services can shut down you right and so + + align:start position:0% +Services can shut down you right and so + + + align:start position:0% +Services can shut down you right and so +that will actually happen once they sort + + align:start position:0% +that will actually happen once they sort + + + align:start position:0% +that will actually happen once they sort +of have these istics running that see + + align:start position:0% +of have these istics running that see + + + align:start position:0% +of have these istics running that see +that you're sending to a lot of people + + align:start position:0% +that you're sending to a lot of people + + + align:start position:0% +that you're sending to a lot of people +you've never sent before and so on and + + align:start position:0% +you've never sent before and so on and + + + align:start position:0% +you've never sent before and so on and +so forth there's a lot of sort of AI + + align:start position:0% +so forth there's a lot of sort of AI + + + align:start position:0% +so forth there's a lot of sort of AI +strategy that takes place on the web + + align:start position:0% +strategy that takes place on the web + + + align:start position:0% +strategy that takes place on the web +mail server side to try to predict these + + align:start position:0% +mail server side to try to predict these + + + align:start position:0% +mail server side to try to predict these +things but these things can be very + + align:start position:0% +things but these things can be very + + + align:start position:0% +things but these things can be very +valuable to an attacker because even if + + align:start position:0% +valuable to an attacker because even if + + + align:start position:0% +valuable to an attacker because even if +um your compromised account is not used + + align:start position:0% +um your compromised account is not used + + + align:start position:0% +um your compromised account is not used +to send a lot of emails it can be used + + align:start position:0% +to send a lot of emails it can be used + + + align:start position:0% +to send a lot of emails it can be used +to send emails to people that you know + + align:start position:0% +to send emails to people that you know + + + align:start position:0% +to send emails to people that you know +right and so maybe it allows the + + align:start position:0% +right and so maybe it allows the + + + align:start position:0% +right and so maybe it allows the +attacker to do things like spear fishing + + align:start position:0% +attacker to do things like spear fishing + + + align:start position:0% +attacker to do things like spear fishing +more easily or things like that so + + align:start position:0% +more easily or things like that so + + + align:start position:0% +more easily or things like that so +people are more likely to click on an + + align:start position:0% +people are more likely to click on an + + + align:start position:0% +people are more likely to click on an +email that comes from an email address + + align:start position:0% +email that comes from an email address + + + align:start position:0% +email that comes from an email address +that they recognize so that's a very + + align:start position:0% +that they recognize so that's a very + + + align:start position:0% +that they recognize so that's a very +powerful technique there um and then + + align:start position:0% +powerful technique there um and then + + + align:start position:0% +powerful technique there um and then +attackers can also try to do things like + + align:start position:0% +attackers can also try to do things like + + + align:start position:0% +attackers can also try to do things like +um hijack uh IP + + align:start position:0% +um hijack uh IP + + + align:start position:0% +um hijack uh IP +addresses from legitimate + + align:start position:0% +addresses from legitimate + + + align:start position:0% +addresses from legitimate +owners so uh as was uh mentioned briefly + + align:start position:0% +owners so uh as was uh mentioned briefly + + + align:start position:0% +owners so uh as was uh mentioned briefly +uh in Mark's talk so uh there's this + + align:start position:0% +uh in Mark's talk so uh there's this + + + align:start position:0% +uh in Mark's talk so uh there's this +protocol called bgp that basically is + + align:start position:0% +protocol called bgp that basically is + + + align:start position:0% +protocol called bgp that basically is +used to control routing on the internet + + align:start position:0% +used to control routing on the internet + + + align:start position:0% +used to control routing on the internet +right so there are these attacks that + + align:start position:0% +right so there are these attacks that + + + align:start position:0% +right so there are these attacks that +people can do whereby they will + + align:start position:0% +people can do whereby they will + + + align:start position:0% +people can do whereby they will +essentially say hey I am actually the + + align:start position:0% +essentially say hey I am actually the + + + align:start position:0% +essentially say hey I am actually the +owner of you know some prefix of IP + + align:start position:0% +owner of you know some prefix of IP + + + align:start position:0% +owner of you know some prefix of IP +addresses even though they don't + + align:start position:0% +addresses even though they don't + + + align:start position:0% +addresses even though they don't +actually own it so all the traffic + + align:start position:0% +actually own it so all the traffic + + + align:start position:0% +actually own it so all the traffic +that's involving those addresses will go + + align:start position:0% +that's involving those addresses will go + + + align:start position:0% +that's involving those addresses will go +in towards the attacker and then they + + align:start position:0% +in towards the attacker and then they + + + align:start position:0% +in towards the attacker and then they +can actually use those addresses send + + align:start position:0% +can actually use those addresses send + + + align:start position:0% +can actually use those addresses send +out um spam from there and then once + + align:start position:0% +out um spam from there and then once + + + align:start position:0% +out um spam from there and then once +they're done with their evil they can + + align:start position:0% +they're done with their evil they can + + + align:start position:0% +they're done with their evil they can +release the bgp advertisement and then + + align:start position:0% +release the bgp advertisement and then + + + align:start position:0% +release the bgp advertisement and then +you know go try to do this somewhere + + align:start position:0% +you know go try to do this somewhere + + + align:start position:0% +you know go try to do this somewhere +else um so there's been a lot of + + align:start position:0% +else um so there's been a lot of + + + align:start position:0% +else um so there's been a lot of +research in how you can essentially + + align:start position:0% +research in how you can essentially + + + align:start position:0% +research in how you can essentially +think of ways to authenticate bgp R + + align:start position:0% +think of ways to authenticate bgp R + + + align:start position:0% +think of ways to authenticate bgp R +advertisements or otherwise prevent + + align:start position:0% +advertisements or otherwise prevent + + + align:start position:0% +advertisements or otherwise prevent +these IP address hijacks um so there's a + + align:start position:0% +these IP address hijacks um so there's a + + + align:start position:0% +these IP address hijacks um so there's a +bunch of different techniques that + + align:start position:0% +bunch of different techniques that + + + align:start position:0% +bunch of different techniques that +attackers can do to try to get around + + align:start position:0% +attackers can do to try to get around + + + align:start position:0% +attackers can do to try to get around +some of these uh defensive techniques um + + align:start position:0% +some of these uh defensive techniques um + + + align:start position:0% +some of these uh defensive techniques um +so so this can all be done but still you + + align:start position:0% +so so this can all be done but still you + + + align:start position:0% +so so this can all be done but still you +know these these defenses they're + + align:start position:0% +know these these defenses they're + + + align:start position:0% +know these these defenses they're +they're not free so presumably the + + align:start position:0% +they're not free so presumably the + + + align:start position:0% +they're not free so presumably the +attackers have to pay for the botn net + + align:start position:0% +attackers have to pay for the botn net + + + align:start position:0% +attackers have to pay for the botn net +somehow they have to you know get inside + + align:start position:0% +somehow they have to you know get inside + + + align:start position:0% +somehow they have to you know get inside +these web mail accounts and so any of + + align:start position:0% +these web mail accounts and so any of + + + align:start position:0% +these web mail accounts and so any of +these defenses that you can do will help + + align:start position:0% +these defenses that you can do will help + + + align:start position:0% +these defenses that you can do will help +to drive the cost up of generating these + + align:start position:0% +to drive the cost up of generating these + + + align:start position:0% +to drive the cost up of generating these +spams and so as such they are still + + align:start position:0% +spams and so as such they are still + + + align:start position:0% +spams and so as such they are still +useful even though they're not sort of U + + align:start position:0% +useful even though they're not sort of U + + + align:start position:0% +useful even though they're not sort of U +perfect + + align:start position:0% +perfect + + + align:start position:0% +perfect +defenses so yeah so what do um these + + align:start position:0% +defenses so yeah so what do um these + + + align:start position:0% +defenses so yeah so what do um these +botn nets look like so uh at a high + + align:start position:0% +botn nets look like so uh at a high + + + align:start position:0% +botn nets look like so uh at a high +level you uh have the + + align:start position:0% +level you uh have the + + + align:start position:0% +level you uh have the +proverbial cloud from your Cloud diagram + + align:start position:0% +proverbial cloud from your Cloud diagram + + + align:start position:0% +proverbial cloud from your Cloud diagram +so you have your control uh command and + + align:start position:0% +so you have your control uh command and + + + align:start position:0% +so you have your control uh command and +control infrastructure out here and this + + align:start position:0% +control infrastructure out here and this + + + align:start position:0% +control infrastructure out here and this +is the thing that actually sends + + align:start position:0% +is the thing that actually sends + + + align:start position:0% +is the thing that actually sends +commands to all of the uh individual uh + + align:start position:0% +commands to all of the uh individual uh + + + align:start position:0% +commands to all of the uh individual uh +Bots down here right so the spammer will + + align:start position:0% +Bots down here right so the spammer will + + + align:start position:0% +Bots down here right so the spammer will +talk to the CNC and we say hey here's my + + align:start position:0% +talk to the CNC and we say hey here's my + + + align:start position:0% +talk to the CNC and we say hey here's my +new spam message that I want to send + + align:start position:0% +new spam message that I want to send + + + align:start position:0% +new spam message that I want to send +let's say and then maybe these Bots will + + align:start position:0% +let's say and then maybe these Bots will + + + align:start position:0% +let's say and then maybe these Bots will +you know act on behalf of the command + + align:start position:0% +you know act on behalf of the command + + + align:start position:0% +you know act on behalf of the command +and control infrastructure and start + + align:start position:0% +and control infrastructure and start + + + align:start position:0% +and control infrastructure and start +sending emails to a bunch of + + align:start position:0% +sending emails to a bunch of + + + align:start position:0% +sending emails to a bunch of +people so uh let's see here so why are + + align:start position:0% +people so uh let's see here so why are + + + align:start position:0% +people so uh let's see here so why are +these Bots useful well as we mentioned + + align:start position:0% +these Bots useful well as we mentioned + + + align:start position:0% +these Bots useful well as we mentioned +here they have IP addresses which are + + align:start position:0% +here they have IP addresses which are + + + align:start position:0% +here they have IP addresses which are +Super useful but of course they also + + align:start position:0% +Super useful but of course they also + + + align:start position:0% +Super useful but of course they also +have the associated bandwidth there they + + align:start position:0% +have the associated bandwidth there they + + + align:start position:0% +have the associated bandwidth there they +also have computational Cycles sometimes + + align:start position:0% +also have computational Cycles sometimes + + + align:start position:0% +also have computational Cycles sometimes +these Bots are actually used as web + + align:start position:0% +these Bots are actually used as web + + + align:start position:0% +these Bots are actually used as web +servers themselves so these things are + + align:start position:0% +servers themselves so these things are + + + align:start position:0% +servers themselves so these things are +are very very useful um and they + + align:start position:0% +are very very useful um and they + + + align:start position:0% +are very very useful um and they +also excuse me serve as a layer of + + align:start position:0% +also excuse me serve as a layer of + + + align:start position:0% +also excuse me serve as a layer of +indirection so as we'll discuss in more + + align:start position:0% +indirection so as we'll discuss in more + + + align:start position:0% +indirection so as we'll discuss in more +detail in a second indirection is very + + align:start position:0% +detail in a second indirection is very + + + align:start position:0% +detail in a second indirection is very +useful for attackers because that means + + align:start position:0% +useful for attackers because that means + + + align:start position:0% +useful for attackers because that means +that you know if law enforcement or + + align:start position:0% +that you know if law enforcement or + + + align:start position:0% +that you know if law enforcement or +whatnot sort of shuts down this level + + align:start position:0% +whatnot sort of shuts down this level + + + align:start position:0% +whatnot sort of shuts down this level +well if the commanding control + + align:start position:0% +well if the commanding control + + + align:start position:0% +well if the commanding control +infrastructure still alive then maybe + + align:start position:0% +infrastructure still alive then maybe + + + align:start position:0% +infrastructure still alive then maybe +the spammer can just sort of attach this + + align:start position:0% +the spammer can just sort of attach this + + + align:start position:0% +the spammer can just sort of attach this +commanding control infrastructure to a + + align:start position:0% +commanding control infrastructure to a + + + align:start position:0% +commanding control infrastructure to a +different set of bots and keep on + + align:start position:0% +different set of bots and keep on + + + align:start position:0% +different set of bots and keep on +running uh so this is one reason why uh + + align:start position:0% +running uh so this is one reason why uh + + + align:start position:0% +running uh so this is one reason why uh +these Bots are very useful and these + + align:start position:0% +these Bots are very useful and these + + + align:start position:0% +these Bots are very useful and these +Bots can scale to the order of magnitude + + align:start position:0% +Bots can scale to the order of magnitude + + + align:start position:0% +Bots can scale to the order of magnitude +of let's say millions of IP addresses + + align:start position:0% +of let's say millions of IP addresses + + + align:start position:0% +of let's say millions of IP addresses +right so as it turns out people will + + align:start position:0% +right so as it turns out people will + + + align:start position:0% +right so as it turns out people will +click random links involving malware all + + align:start position:0% +click random links involving malware all + + + align:start position:0% +click random links involving malware all +the time so these things can get very + + align:start position:0% +the time so these things can get very + + + align:start position:0% +the time so these things can get very +very very large um and so some of these + + align:start position:0% +very very large um and so some of these + + + align:start position:0% +very very large um and so some of these +takedowns that these companies get + + align:start position:0% +takedowns that these companies get + + + align:start position:0% +takedowns that these companies get +involved in with trying to take down + + align:start position:0% +involved in with trying to take down + + + align:start position:0% +involved in with trying to take down +these botn nets they involve Millions + + align:start position:0% +these botn nets they involve Millions + + + align:start position:0% +these botn nets they involve Millions +upon millions of machines so they're + + align:start position:0% +upon millions of machines so they're + + + align:start position:0% +upon millions of machines so they're +very sort of technically uh challenging + + align:start position:0% +very sort of technically uh challenging + + + align:start position:0% +very sort of technically uh challenging +so how much does it cost to get your + + align:start position:0% +so how much does it cost to get your + + + align:start position:0% +so how much does it cost to get your +malware installed on all these Bots + + align:start position:0% +malware installed on all these Bots + + + align:start position:0% +malware installed on all these Bots +remember remember these are all uh + + align:start position:0% +remember remember these are all uh + + + align:start position:0% +remember remember these are all uh +typically regular enduser machines so + + align:start position:0% +typically regular enduser machines so + + + align:start position:0% +typically regular enduser machines so +the cost for getting your uh malware on + + align:start position:0% +the cost for getting your uh malware on + + + align:start position:0% +the cost for getting your uh malware on +one of these + + align:start position:0% +one of these + + + align:start position:0% +one of these +machines so priced per + + align:start position:0% +machines so priced per + + + align:start position:0% +machines so priced per +host is about uh about 10 + + align:start position:0% +host is about uh about 10 + + + align:start position:0% +host is about uh about 10 +cents for us + + align:start position:0% + + + + align:start position:0% + +hosts and on the order of uh 1 + + align:start position:0% +hosts and on the order of uh 1 + + + align:start position:0% +hosts and on the order of uh 1 +cent uh for uh host in + + align:start position:0% +cent uh for uh host in + + + align:start position:0% +cent uh for uh host in +Asia + + align:start position:0% +Asia + + + align:start position:0% +Asia +so it's interesting there's this + + align:start position:0% +so it's interesting there's this + + + align:start position:0% +so it's interesting there's this +differential here um and so there might + + align:start position:0% +differential here um and so there might + + + align:start position:0% +differential here um and so there might +be a couple reasons we can imagine for + + align:start position:0% +be a couple reasons we can imagine for + + + align:start position:0% +be a couple reasons we can imagine for +why that is it might be that uh people + + align:start position:0% +why that is it might be that uh people + + + align:start position:0% +why that is it might be that uh people +are prone to think that uh you know + + align:start position:0% +are prone to think that uh you know + + + align:start position:0% +are prone to think that uh you know +connections originating from the US are + + align:start position:0% +connections originating from the US are + + + align:start position:0% +connections originating from the US are +more likely to be trustworthy right it + + align:start position:0% +more likely to be trustworthy right it + + + align:start position:0% +more likely to be trustworthy right it +may also be that because there's more + + align:start position:0% +may also be that because there's more + + + align:start position:0% +may also be that because there's more +pirate software running here and stuff + + align:start position:0% +pirate software running here and stuff + + + align:start position:0% +pirate software running here and stuff +that's like not actively up to date with + + align:start position:0% +that's like not actively up to date with + + + align:start position:0% +that's like not actively up to date with +respect to Patches it's actually easier + + align:start position:0% +respect to Patches it's actually easier + + + align:start position:0% +respect to Patches it's actually easier +to get botnet host over here so you'll + + align:start position:0% +to get botnet host over here so you'll + + + align:start position:0% +to get botnet host over here so you'll +see some some very interesting + + align:start position:0% +see some some very interesting + + + align:start position:0% +see some some very interesting +statistics about um sort of how some of + + align:start position:0% +statistics about um sort of how some of + + + align:start position:0% +statistics about um sort of how some of +these rates might fluctuate for example + + align:start position:0% +these rates might fluctuate for example + + + align:start position:0% +these rates might fluctuate for example +as you know let's say companies like + + align:start position:0% +as you know let's say companies like + + + align:start position:0% +as you know let's say companies like +Microsoft go out and they say you know + + align:start position:0% +Microsoft go out and they say you know + + + align:start position:0% +Microsoft go out and they say you know +they try to stamp down on piracy and + + align:start position:0% +they try to stamp down on piracy and + + + align:start position:0% +they try to stamp down on piracy and +things like that but anyways that this + + align:start position:0% +things like that but anyways that this + + + align:start position:0% +things like that but anyways that this +is a rough estimate to say this is not + + align:start position:0% +is a rough estimate to say this is not + + + align:start position:0% +is a rough estimate to say this is not +uh super + + align:start position:0% +uh super + + + align:start position:0% +uh super +expensive so what does uh any questions + + align:start position:0% +expensive so what does uh any questions + + + align:start position:0% +expensive so what does uh any questions +before we continue okay so so what is + + align:start position:0% +before we continue okay so so what is + + + align:start position:0% +before we continue okay so so what is +this uh command and control + + align:start position:0% +this uh command and control + + + align:start position:0% +this uh command and control +infrastructure look like so you can + + align:start position:0% +infrastructure look like so you can + + + align:start position:0% +infrastructure look like so you can +imagine that uh in one instantiation the + + align:start position:0% +imagine that uh in one instantiation the + + + align:start position:0% +imagine that uh in one instantiation the +simplest instantiation this is just uh + + align:start position:0% +simplest instantiation this is just uh + + + align:start position:0% +simplest instantiation this is just uh +some centralized + + align:start position:0% +some centralized + + + align:start position:0% +some centralized +setup and so this is maybe you know know + + align:start position:0% +setup and so this is maybe you know know + + + align:start position:0% +setup and so this is maybe you know know +one machine or maybe some small number + + align:start position:0% +one machine or maybe some small number + + + align:start position:0% +one machine or maybe some small number +of machines the attacker can just log + + align:start position:0% +of machines the attacker can just log + + + align:start position:0% +of machines the attacker can just log +into those machines and then just + + align:start position:0% +into those machines and then just + + + align:start position:0% +into those machines and then just +essentially send these commands out to + + align:start position:0% +essentially send these commands out to + + + align:start position:0% +essentially send these commands out to +the botn Nets from there um so if it's + + align:start position:0% +the botn Nets from there um so if it's + + + align:start position:0% +the botn Nets from there um so if it's +going to be centralized and it's going + + align:start position:0% +going to be centralized and it's going + + + align:start position:0% +going to be centralized and it's going +to be very useful for um the attacker to + + align:start position:0% +to be very useful for um the attacker to + + + align:start position:0% +to be very useful for um the attacker to +have what's known as a bulletproof + + align:start position:0% + + + + align:start position:0% + +hosting and so the idea behind + + align:start position:0% +hosting and so the idea behind + + + align:start position:0% +hosting and so the idea behind +bulletproof hosting is that you want to + + align:start position:0% +bulletproof hosting is that you want to + + + align:start position:0% +bulletproof hosting is that you want to +put this uh command and control + + align:start position:0% +put this uh command and control + + + align:start position:0% +put this uh command and control +infrastructure on servers that are + + align:start position:0% +infrastructure on servers that are + + + align:start position:0% +infrastructure on servers that are +that reside in let's say uh isps that + + align:start position:0% +that reside in let's say uh isps that + + + align:start position:0% +that reside in let's say uh isps that +ignore you know requests from Banks or + + align:start position:0% +ignore you know requests from Banks or + + + align:start position:0% +ignore you know requests from Banks or +from law enforcement to take down + + align:start position:0% +from law enforcement to take down + + + align:start position:0% +from law enforcement to take down +servers right and so there are actually + + align:start position:0% +servers right and so there are actually + + + align:start position:0% +servers right and so there are actually +bulletproof servers that exist they + + align:start position:0% +bulletproof servers that exist they + + + align:start position:0% +bulletproof servers that exist they +charge a premium right because there's a + + align:start position:0% +charge a premium right because there's a + + + align:start position:0% +charge a premium right because there's a +little bit of risk involved there but if + + align:start position:0% +little bit of risk involved there but if + + + align:start position:0% +little bit of risk involved there but if +you can manage to host one of your + + align:start position:0% +you can manage to host one of your + + + align:start position:0% +you can manage to host one of your +command and control centers there you're + + align:start position:0% +command and control centers there you're + + + align:start position:0% +command and control centers there you're +it's going to be very nice because then + + align:start position:0% +it's going to be very nice because then + + + align:start position:0% +it's going to be very nice because then +when the American government or when + + align:start position:0% +when the American government or when + + + align:start position:0% +when the American government or when +Goldman Sachs or whoever says hey shut + + align:start position:0% +Goldman Sachs or whoever says hey shut + + + align:start position:0% +Goldman Sachs or whoever says hey shut +this guy down they're running spam the + + align:start position:0% +this guy down they're running spam the + + + align:start position:0% +this guy down they're running spam the +provider will say how can you make me I + + align:start position:0% +provider will say how can you make me I + + + align:start position:0% +provider will say how can you make me I +run in a different legal jurisdiction I + + align:start position:0% +run in a different legal jurisdiction I + + + align:start position:0% +run in a different legal jurisdiction I +don't have to follow your intellectual + + align:start position:0% +don't have to follow your intellectual + + + align:start position:0% +don't have to follow your intellectual +property laws you know so on and so + + align:start position:0% +property laws you know so on and so + + + align:start position:0% +property laws you know so on and so +forth um so this is very useful but like + + align:start position:0% +forth um so this is very useful but like + + + align:start position:0% +forth um so this is very useful but like +I said uh these types of hosts actually + + align:start position:0% +I said uh these types of hosts actually + + + align:start position:0% +I said uh these types of hosts actually +charge uh a risk premium for running + + align:start position:0% +charge uh a risk premium for running + + + align:start position:0% +charge uh a risk premium for running +that kind of service uh and so the other + + align:start position:0% +that kind of service uh and so the other + + + align:start position:0% +that kind of service uh and so the other +alternative for running the CNC + + align:start position:0% +alternative for running the CNC + + + align:start position:0% +alternative for running the CNC +infrastructure is this could be um sort + + align:start position:0% +infrastructure is this could be um sort + + + align:start position:0% +infrastructure is this could be um sort +of a peer toer + + align:start position:0% + + + + align:start position:0% + +Network and so the idea here is that + + align:start position:0% +Network and so the idea here is that + + + align:start position:0% +Network and so the idea here is that +maybe um maybe this is sort of almost + + align:start position:0% +maybe um maybe this is sort of almost + + + align:start position:0% +maybe um maybe this is sort of almost +think of it as like a mini botn net up + + align:start position:0% +think of it as like a mini botn net up + + + align:start position:0% +think of it as like a mini botn net up +there too so so the entire control + + align:start position:0% +there too so so the entire control + + + align:start position:0% +there too so so the entire control +infrastructure is spread across many + + align:start position:0% +infrastructure is spread across many + + + align:start position:0% +infrastructure is spread across many +different machines and maybe at any + + align:start position:0% +different machines and maybe at any + + + align:start position:0% +different machines and maybe at any +given time there's a different machine + + align:start position:0% +given time there's a different machine + + + align:start position:0% +given time there's a different machine +that's responsible for sending commands + + align:start position:0% +that's responsible for sending commands + + + align:start position:0% +that's responsible for sending commands +to all of these worker noes down here + + align:start position:0% +to all of these worker noes down here + + + align:start position:0% +to all of these worker noes down here +and so this is nice because it doesn't + + align:start position:0% +and so this is nice because it doesn't + + + align:start position:0% +and so this is nice because it doesn't +require you to have access to one of + + align:start position:0% +require you to have access to one of + + + align:start position:0% +require you to have access to one of +these bulletproof hosts um you can sort + + align:start position:0% +these bulletproof hosts um you can sort + + + align:start position:0% +these bulletproof hosts um you can sort +of construct the CNC infrastructure + + align:start position:0% +of construct the CNC infrastructure + + + align:start position:0% +of construct the CNC infrastructure +using uh regular bot uh the P2P aspect + + align:start position:0% +using uh regular bot uh the P2P aspect + + + align:start position:0% +using uh regular bot uh the P2P aspect +of it makes it a little bit more + + align:start position:0% +of it makes it a little bit more + + + align:start position:0% +of it makes it a little bit more +difficult to provide guarantees about + + align:start position:0% +difficult to provide guarantees about + + + align:start position:0% +difficult to provide guarantees about +for example the availability of the + + align:start position:0% +for example the availability of the + + + align:start position:0% +for example the availability of the +hosts that are up here but it does have + + align:start position:0% +hosts that are up here but it does have + + + align:start position:0% +hosts that are up here but it does have +some other nice advantages so at high + + align:start position:0% +some other nice advantages so at high + + + align:start position:0% +some other nice advantages so at high +level those are the two um the two + + align:start position:0% +level those are the two um the two + + + align:start position:0% +level those are the two um the two +approaches that people can use use so + + align:start position:0% +approaches that people can use use so + + + align:start position:0% +approaches that people can use use so +what happens if uh so if the hosting + + align:start position:0% + + + + align:start position:0% + +service gets taken + + align:start position:0% + + + + align:start position:0% + +down well there's a couple things that + + align:start position:0% +down well there's a couple things that + + + align:start position:0% +down well there's a couple things that +the adversary can do so they can use + + align:start position:0% +the adversary can do so they can use + + + align:start position:0% +the adversary can do so they can use +um DNS to essentially redirect + + align:start position:0% + + + + align:start position:0% + +requests + + align:start position:0% + + + + align:start position:0% + +right so let's say that um someone + + align:start position:0% +right so let's say that um someone + + + align:start position:0% +right so let's say that um someone +attacks let's say or someone issues a + + align:start position:0% +attacks let's say or someone issues a + + + align:start position:0% +attacks let's say or someone issues a +takedown for the DNS infrastructure or + + align:start position:0% +takedown for the DNS infrastructure or + + + align:start position:0% +takedown for the DNS infrastructure or +something like this as long as the + + align:start position:0% +something like this as long as the + + + align:start position:0% +something like this as long as the +backend servers are still alive what the + + align:start position:0% +backend servers are still alive what the + + + align:start position:0% +backend servers are still alive what the +attacker can do is basically + + align:start position:0% +attacker can do is basically + + + align:start position:0% +attacker can do is basically +um the attacker + + align:start position:0% +um the attacker + + + align:start position:0% +um the attacker +creates a + + align:start position:0% +creates a + + + align:start position:0% +creates a +list of server IP + + align:start position:0% + + + + align:start position:0% + +addresses and there may be hundreds or + + align:start position:0% +addresses and there may be hundreds or + + + align:start position:0% +addresses and there may be hundreds or +thousands of these IP addresses that it + + align:start position:0% +thousands of these IP addresses that it + + + align:start position:0% +thousands of these IP addresses that it +collects and then it will uh + + align:start position:0% +collects and then it will uh + + + align:start position:0% +collects and then it will uh +bind uh each + + align:start position:0% +bind uh each + + + align:start position:0% +bind uh each +one to a host name for a very short + + align:start position:0% +one to a host name for a very short + + + align:start position:0% +one to a host name for a very short +period of + + align:start position:0% +period of + + + align:start position:0% +period of +time so let's say maybe for uh 300 + + align:start position:0% + + + + align:start position:0% + +seconds and so what's nice about this is + + align:start position:0% +seconds and so what's nice about this is + + + align:start position:0% +seconds and so what's nice about this is +that if someone's trying to run heris + + align:start position:0% +that if someone's trying to run heris + + + align:start position:0% +that if someone's trying to run heris +sixs that say like if I see you know + + align:start position:0% +sixs that say like if I see you know + + + align:start position:0% +sixs that say like if I see you know +some particular a server sending you + + align:start position:0% +some particular a server sending you + + + align:start position:0% +some particular a server sending you +know more than let's say I don't know a + + align:start position:0% +know more than let's say I don't know a + + + align:start position:0% +know more than let's say I don't know a +thousand spam like messages in a given + + align:start position:0% +thousand spam like messages in a given + + + align:start position:0% +thousand spam like messages in a given +period I'm going to try to issue some + + align:start position:0% +period I'm going to try to issue some + + + align:start position:0% +period I'm going to try to issue some +some type of takedown to them well these + + align:start position:0% +some type of takedown to them well these + + + align:start position:0% +some type of takedown to them well these +types of techniques will maybe help uh + + align:start position:0% +types of techniques will maybe help uh + + + align:start position:0% +types of techniques will maybe help uh +the attacker fly under the radar of + + align:start position:0% +the attacker fly under the radar of + + + align:start position:0% +the attacker fly under the radar of +those types of detection techniques + + align:start position:0% +those types of detection techniques + + + align:start position:0% +those types of detection techniques +because essentially every 300 seconds + + align:start position:0% +because essentially every 300 seconds + + + align:start position:0% +because essentially every 300 seconds +they're saying okay I'm going to be + + align:start position:0% +they're saying okay I'm going to be + + + align:start position:0% +they're saying okay I'm going to be +serving spam from here okay then me + + align:start position:0% +serving spam from here okay then me + + + align:start position:0% +serving spam from here okay then me +sering spam from here sering SP from + + align:start position:0% +sering spam from here sering SP from + + + align:start position:0% +sering spam from here sering SP from +here so on and so forth so this is a + + align:start position:0% +here so on and so forth so this is a + + + align:start position:0% +here so on and so forth so this is a +nice uh use of indirection at least from + + align:start position:0% +nice uh use of indirection at least from + + + align:start position:0% +nice uh use of indirection at least from +the attacker's perspective uh and + + align:start position:0% +the attacker's perspective uh and + + + align:start position:0% +the attacker's perspective uh and +so so as I mentioned earlier these types + + align:start position:0% +so so as I mentioned earlier these types + + + align:start position:0% +so so as I mentioned earlier these types +of indirections are one of the key ways + + align:start position:0% +of indirections are one of the key ways + + + align:start position:0% +of indirections are one of the key ways +that attackers try to evade uh law + + align:start position:0% +that attackers try to evade uh law + + + align:start position:0% +that attackers try to evade uh law +enforcement in these detection her + + align:start position:0% +enforcement in these detection her + + + align:start position:0% +enforcement in these detection her +istics uh so you might think about well + + align:start position:0% +istics uh so you might think about well + + + align:start position:0% +istics uh so you might think about well +what if we just take down the DNS server + + align:start position:0% +what if we just take down the DNS server + + + align:start position:0% +what if we just take down the DNS server +how hard is it to do that well as the + + align:start position:0% +how hard is it to do that well as the + + + align:start position:0% +how hard is it to do that well as the +paper describes there's a couple + + align:start position:0% +paper describes there's a couple + + + align:start position:0% +paper describes there's a couple +different layers of which you can attack + + align:start position:0% +different layers of which you can attack + + + align:start position:0% +different layers of which you can attack +these spammers so you can try to take + + align:start position:0% +these spammers so you can try to take + + + align:start position:0% +these spammers so you can try to take +down the attacker um domain registration + + align:start position:0% +down the attacker um domain registration + + + align:start position:0% +down the attacker um domain registration +so that's basically the thing that says + + align:start position:0% +so that's basically the thing that says + + + align:start position:0% +so that's basically the thing that says +like hey if you're looking for you know + + align:start position:0% +like hey if you're looking for you know + + + align:start position:0% +like hey if you're looking for you know +uh Russian Pharma you know rx. biz.org + + align:start position:0% +uh Russian Pharma you know rx. biz.org + + + align:start position:0% +uh Russian Pharma you know rx. biz.org +then here's the uh d that you talked to + + align:start position:0% +then here's the uh d that you talked to + + + align:start position:0% +then here's the uh d that you talked to +you can imagine attacking it at that + + align:start position:0% +you can imagine attacking it at that + + + align:start position:0% +you can imagine attacking it at that +level you could also Imagine attacking + + align:start position:0% +level you could also Imagine attacking + + + align:start position:0% +level you could also Imagine attacking +it at the level of taking down the uh + + align:start position:0% +it at the level of taking down the uh + + + align:start position:0% +it at the level of taking down the uh +spammer DNS server right the thing to + + align:start position:0% +spammer DNS server right the thing to + + + align:start position:0% +spammer DNS server right the thing to +which you'll be redirected once you look + + align:start position:0% +which you'll be redirected once you look + + + align:start position:0% +which you'll be redirected once you look +at that top level uh domain and so + + align:start position:0% +at that top level uh domain and so + + + align:start position:0% +at that top level uh domain and so +what's tricky is that the attacker can + + align:start position:0% +what's tricky is that the attacker can + + + align:start position:0% +what's tricky is that the attacker can +use these sort of uh fast flux + + align:start position:0% +use these sort of uh fast flux + + + align:start position:0% +use these sort of uh fast flux +techniques at every different level so + + align:start position:0% +techniques at every different level so + + + align:start position:0% +techniques at every different level so +for example they can uh rotate the + + align:start position:0% +for example they can uh rotate the + + + align:start position:0% +for example they can uh rotate the +servers that they use to act as their + + align:start position:0% +servers that they use to act as their + + + align:start position:0% +servers that they use to act as their +DNS servers they can rotate uh the the + + align:start position:0% +DNS servers they can rotate uh the the + + + align:start position:0% +DNS servers they can rotate uh the the +uh the web servers they use to to send + + align:start position:0% +uh the web servers they use to to send + + + align:start position:0% +uh the web servers they use to to send +out the spam and so on and so forth so + + align:start position:0% +out the spam and so on and so forth so + + + align:start position:0% +out the spam and so on and so forth so +that's just a sort of high level + + align:start position:0% +that's just a sort of high level + + + align:start position:0% +that's just a sort of high level +overview of how people can use multiple + + align:start position:0% +overview of how people can use multiple + + + align:start position:0% +overview of how people can use multiple +machines to try to uh avoid + + align:start position:0% + + + + align:start position:0% + +detection so as I mentioned uh earlier + + align:start position:0% +detection so as I mentioned uh earlier + + + align:start position:0% +detection so as I mentioned uh earlier +you can use + + align:start position:0% +you can use + + + align:start position:0% +you can use +compromised uh web mail + + align:start position:0% + + + + align:start position:0% + +accounts to send + + align:start position:0% + + + + align:start position:0% + +spam and the power of + + align:start position:0% +spam and the power of + + + align:start position:0% +spam and the power of +that is that if you can get access to + + align:start position:0% +that is that if you can get access to + + + align:start position:0% +that is that if you can get access to +someone's account you don't actually + + align:start position:0% +someone's account you don't actually + + + align:start position:0% +someone's account you don't actually +have to install malware in their machine + + align:start position:0% +have to install malware in their machine + + + align:start position:0% +have to install malware in their machine +right you can actually access their + + align:start position:0% +right you can actually access their + + + align:start position:0% +right you can actually access their +account from the privacy of your own + + align:start position:0% +account from the privacy of your own + + + align:start position:0% +account from the privacy of your own +machine you know wherever is that you're + + align:start position:0% +machine you know wherever is that you're + + + align:start position:0% +machine you know wherever is that you're +located and as we were discussing + + align:start position:0% +located and as we were discussing + + + align:start position:0% +located and as we were discussing +earlier this is useful for spear fishing + + align:start position:0% +earlier this is useful for spear fishing + + + align:start position:0% +earlier this is useful for spear fishing +attacks because you can send this spam + + align:start position:0% +attacks because you can send this spam + + + align:start position:0% +attacks because you can send this spam +message as the person whose account it + + align:start position:0% +message as the person whose account it + + + align:start position:0% +message as the person whose account it +actually belongs to and so as a result + + align:start position:0% +actually belongs to and so as a result + + + align:start position:0% +actually belongs to and so as a result +the web mail providers are very + + align:start position:0% +the web mail providers are very + + + align:start position:0% +the web mail providers are very +motivated to shut this kind of thing + + align:start position:0% +motivated to shut this kind of thing + + + align:start position:0% +motivated to shut this kind of thing +down right because if they don't do that + + align:start position:0% +down right because if they don't do that + + + align:start position:0% +down right because if they don't do that +then they risk being blacklisted as a + + align:start position:0% +then they risk being blacklisted as a + + + align:start position:0% +then they risk being blacklisted as a +whole right all of their users risk + + align:start position:0% +whole right all of their users risk + + + align:start position:0% +whole right all of their users risk +being a flag to spamming which they + + align:start position:0% +being a flag to spamming which they + + + align:start position:0% +being a flag to spamming which they +don't want and also the provider + + align:start position:0% +don't want and also the provider + + + align:start position:0% +don't want and also the provider +actually needs needs to somehow monetize + + align:start position:0% +actually needs needs to somehow monetize + + + align:start position:0% +actually needs needs to somehow monetize +their service somehow they actually need + + align:start position:0% +their service somehow they actually need + + + align:start position:0% +their service somehow they actually need +real users to be able to you know be + + align:start position:0% +real users to be able to you know be + + + align:start position:0% +real users to be able to you know be +doing things like clicking on ads and in + + align:start position:0% +doing things like clicking on ads and in + + + align:start position:0% +doing things like clicking on ads and in +the right hand bar of your Webmail + + align:start position:0% +the right hand bar of your Webmail + + + align:start position:0% +the right hand bar of your Webmail +account so the higher the proportion of + + align:start position:0% +account so the higher the proportion of + + + align:start position:0% +account so the higher the proportion of +their users which are spammy sort of the + + align:start position:0% +their users which are spammy sort of the + + + align:start position:0% +their users which are spammy sort of the +less likely advertisers are to advertise + + align:start position:0% +less likely advertisers are to advertise + + + align:start position:0% +less likely advertisers are to advertise +on their Web Mail system so the Webmail + + align:start position:0% +on their Web Mail system so the Webmail + + + align:start position:0% +on their Web Mail system so the Webmail +account providers are very uh + + align:start position:0% +account providers are very uh + + + align:start position:0% +account providers are very uh +incentivized to sort of shut down this + + align:start position:0% +incentivized to sort of shut down this + + + align:start position:0% +incentivized to sort of shut down this +kind of stuff and so how do they try to + + align:start position:0% +kind of stuff and so how do they try to + + + align:start position:0% +kind of stuff and so how do they try to +detect this type of spam they use those + + align:start position:0% +detect this type of spam they use those + + + align:start position:0% +detect this type of spam they use those +teristics they might try to uh use + + align:start position:0% +teristics they might try to uh use + + + align:start position:0% +teristics they might try to uh use +captas right if they suspect that you've + + align:start position:0% +captas right if they suspect that you've + + + align:start position:0% +captas right if they suspect that you've +sent some spam like messages let's say + + align:start position:0% +sent some spam like messages let's say + + + align:start position:0% +sent some spam like messages let's say +five times in a row they might ask you + + align:start position:0% +five times in a row they might ask you + + + align:start position:0% +five times in a row they might ask you +to you know type in one of those fuzzy + + align:start position:0% +to you know type in one of those fuzzy + + + align:start position:0% +to you know type in one of those fuzzy +letters or whatever um and so suffice it + + align:start position:0% +letters or whatever um and so suffice it + + + align:start position:0% +letters or whatever um and so suffice it +to say though that a lot of these + + align:start position:0% +to say though that a lot of these + + + align:start position:0% +to say though that a lot of these +techniques they don't work very well and + + align:start position:0% +techniques they don't work very well and + + + align:start position:0% +techniques they don't work very well and +so if you look at the uh price per + + align:start position:0% +so if you look at the uh price per + + + align:start position:0% +so if you look at the uh price per +account right so how much you as a + + align:start position:0% +account right so how much you as a + + + align:start position:0% +account right so how much you as a +spammer would have to pay to get one of + + align:start position:0% +spammer would have to pay to get one of + + + align:start position:0% +spammer would have to pay to get one of +these things it's still super super + + align:start position:0% +these things it's still super super + + + align:start position:0% +these things it's still super super +cheap so it's in the order of you know + + align:start position:0% +cheap so it's in the order of you know + + + align:start position:0% +cheap so it's in the order of you know +one to 5 + + align:start position:0% +one to 5 + + + align:start position:0% +one to 5 +cents for an account on Yahoo Gmail + + align:start position:0% +cents for an account on Yahoo Gmail + + + align:start position:0% +cents for an account on Yahoo Gmail +Hotmail something like that so once + + align:start position:0% +Hotmail something like that so once + + + align:start position:0% +Hotmail something like that so once +again this is very very low and so this + + align:start position:0% +again this is very very low and so this + + + align:start position:0% +again this is very very low and so this +does not act as a effective a + + align:start position:0% +does not act as a effective a + + + align:start position:0% +does not act as a effective a +disincentive for spammers to try to do + + align:start position:0% +disincentive for spammers to try to do + + + align:start position:0% +disincentive for spammers to try to do +these types of things so this maybe is a + + align:start position:0% +these types of things so this maybe is a + + + align:start position:0% +these types of things so this maybe is a +little bit disappointing because it + + align:start position:0% +little bit disappointing because it + + + align:start position:0% +little bit disappointing because it +seems like everywhere we go we have to + + align:start position:0% +seems like everywhere we go we have to + + + align:start position:0% +seems like everywhere we go we have to +solve these captures if we want to buy + + align:start position:0% +solve these captures if we want to buy + + + align:start position:0% +solve these captures if we want to buy +things or send emails or that kind of + + align:start position:0% +things or send emails or that kind of + + + align:start position:0% +things or send emails or that kind of +stuff so basically what you know what + + align:start position:0% +stuff so basically what you know what + + + align:start position:0% +stuff so basically what you know what +happened to + + align:start position:0% +happened to + + + align:start position:0% +happened to +captas they were supposed to make all + + align:start position:0% +captas they were supposed to make all + + + align:start position:0% +captas they were supposed to make all +this bad stuff go away and as it turns + + align:start position:0% +this bad stuff go away and as it turns + + + align:start position:0% +this bad stuff go away and as it turns +out um the + + align:start position:0% +out um the + + + align:start position:0% +out um the +attacker can build + + align:start position:0% +attacker can build + + + align:start position:0% +attacker can build +services to solve + + align:start position:0% + + + + align:start position:0% + +captures and so this can be uh automated + + align:start position:0% +captures and so this can be uh automated + + + align:start position:0% +captures and so this can be uh automated +just like anything + + align:start position:0% + + + + align:start position:0% + +else so as it turns out the economics + + align:start position:0% +else so as it turns out the economics + + + align:start position:0% +else so as it turns out the economics +for this is that if you want to solve + + align:start position:0% +for this is that if you want to solve + + + align:start position:0% +for this is that if you want to solve +one capture then it's a approximately + + align:start position:0% + + + + align:start position:0% + +0.001 to solve a capture right which is + + align:start position:0% +0.001 to solve a capture right which is + + + align:start position:0% +0.001 to solve a capture right which is +nothing and this can be done with very + + align:start position:0% +nothing and this can be done with very + + + align:start position:0% +nothing and this can be done with very +very low latency too so captas + + align:start position:0% +very low latency too so captas + + + align:start position:0% +very low latency too so captas +essentially are not presenting uh most + + align:start position:0% +essentially are not presenting uh most + + + align:start position:0% +essentially are not presenting uh most +large scale spammers with a high barrier + + align:start position:0% +large scale spammers with a high barrier + + + align:start position:0% +large scale spammers with a high barrier +for sending these spams and so how's + + align:start position:0% +for sending these spams and so how's + + + align:start position:0% +for sending these spams and so how's +how's this being done if it's this cheap + + align:start position:0% +how's this being done if it's this cheap + + + align:start position:0% +how's this being done if it's this cheap +you might think well maybe it's being + + align:start position:0% +you might think well maybe it's being + + + align:start position:0% +you might think well maybe it's being +done all by you know computers by by + + align:start position:0% +done all by you know computers by by + + + align:start position:0% +done all by you know computers by by +software but it's not actually so a lot + + align:start position:0% +software but it's not actually so a lot + + + align:start position:0% +software but it's not actually so a lot +of this is uh done by + + align:start position:0% + + + + align:start position:0% + +humans and in particular the attacker + + align:start position:0% +humans and in particular the attacker + + + align:start position:0% +humans and in particular the attacker +can Outsource this in one of two ways uh + + align:start position:0% +can Outsource this in one of two ways uh + + + align:start position:0% +can Outsource this in one of two ways uh +so first of all the attacker can just + + align:start position:0% +so first of all the attacker can just + + + align:start position:0% +so first of all the attacker can just +find a labor market where the cost of + + align:start position:0% +find a labor market where the cost of + + + align:start position:0% +find a labor market where the cost of +Labor is very very cheap right and so + + align:start position:0% +Labor is very very cheap right and so + + + align:start position:0% +Labor is very very cheap right and so +you can just you can employ humans to + + align:start position:0% +you can just you can employ humans to + + + align:start position:0% +you can just you can employ humans to +essentially act as capture solvers for + + align:start position:0% +essentially act as capture solvers for + + + align:start position:0% +essentially act as capture solvers for +you right so you the spammer are + + align:start position:0% +you right so you the spammer are + + + align:start position:0% +you right so you the spammer are +presented with the capture by Gmail or + + align:start position:0% +presented with the capture by Gmail or + + + align:start position:0% +presented with the capture by Gmail or +whatever you the spammer then send that + + align:start position:0% +whatever you the spammer then send that + + + align:start position:0% +whatever you the spammer then send that +capture over to some human sitting + + align:start position:0% +capture over to some human sitting + + + align:start position:0% +capture over to some human sitting +somewhere they solve it for you they've + + align:start position:0% +somewhere they solve it for you they've + + + align:start position:0% +somewhere they solve it for you they've +earned you know some small amount of + + align:start position:0% +earned you know some small amount of + + + align:start position:0% +earned you know some small amount of +money and then you sort of send their + + align:start position:0% +money and then you sort of send their + + + align:start position:0% +money and then you sort of send their +answer um to the legitimate site uh you + + align:start position:0% +answer um to the legitimate site uh you + + + align:start position:0% +answer um to the legitimate site uh you +can also do this um with um Mechanical + + align:start position:0% +can also do this um with um Mechanical + + + align:start position:0% +can also do this um with um Mechanical +Turk have you guys heard of uh + + align:start position:0% +Turk have you guys heard of uh + + + align:start position:0% +Turk have you guys heard of uh +Mechanical Turk I've asked a question my + + align:start position:0% +Mechanical Turk I've asked a question my + + + align:start position:0% +Mechanical Turk I've asked a question my +back has turned to you that's poor style + + align:start position:0% +back has turned to you that's poor style + + + align:start position:0% +back has turned to you that's poor style +uh okay so yeah so Mechanical Turk is + + align:start position:0% +uh okay so yeah so Mechanical Turk is + + + align:start position:0% +uh okay so yeah so Mechanical Turk is +pretty neat right well I mean neat if + + align:start position:0% +pretty neat right well I mean neat if + + + align:start position:0% +pretty neat right well I mean neat if +you're trying to do evil so what's nice + + align:start position:0% +you're trying to do evil so what's nice + + + align:start position:0% +you're trying to do evil so what's nice +about that is that you can post these + + align:start position:0% +about that is that you can post these + + + align:start position:0% +about that is that you can post these +tasks to Mechanical Turk and say hey I + + align:start position:0% +tasks to Mechanical Turk and say hey I + + + align:start position:0% +tasks to Mechanical Turk and say hey I +have a picture solving game or something + + align:start position:0% +have a picture solving game or something + + + align:start position:0% +have a picture solving game or something +like this right or you can just come out + + align:start position:0% +like this right or you can just come out + + + align:start position:0% +like this right or you can just come out +and just say straight up hey I got some + + align:start position:0% +and just say straight up hey I got some + + + align:start position:0% +and just say straight up hey I got some +captures I want to solve you post a + + align:start position:0% +captures I want to solve you post a + + + align:start position:0% +captures I want to solve you post a +price and then basically the market will + + align:start position:0% +price and then basically the market will + + + align:start position:0% +price and then basically the market will +match you with people who are willing to + + align:start position:0% +match you with people who are willing to + + + align:start position:0% +match you with people who are willing to +do that task + + align:start position:0% +do that task + + + align:start position:0% +do that task +right and then they'll do it for you + + align:start position:0% +right and then they'll do it for you + + + align:start position:0% +right and then they'll do it for you +they'll post the answers and so this + + align:start position:0% +they'll post the answers and so this + + + align:start position:0% +they'll post the answers and so this +actually uh sort of automates uh a lot + + align:start position:0% +actually uh sort of automates uh a lot + + + align:start position:0% +actually uh sort of automates uh a lot +of actually finding the labor pool um + + align:start position:0% +of actually finding the labor pool um + + + align:start position:0% +of actually finding the labor pool um +for the spammer uh the you know problem + + align:start position:0% +for the spammer uh the you know problem + + + align:start position:0% +for the spammer uh the you know problem +with this is that you have more overhead + + align:start position:0% +with this is that you have more overhead + + + align:start position:0% +with this is that you have more overhead +if you're the spammer because you know + + align:start position:0% +if you're the spammer because you know + + + align:start position:0% +if you're the spammer because you know +Amazon has to take some cut of that + + align:start position:0% +Amazon has to take some cut of that + + + align:start position:0% +Amazon has to take some cut of that +profit that's generated from that but + + align:start position:0% +profit that's generated from that but + + + align:start position:0% +profit that's generated from that but +anyways that's that's very nice there um + + align:start position:0% +anyways that's that's very nice there um + + + align:start position:0% +anyways that's that's very nice there um +and another thing that attackers can do + + align:start position:0% +and another thing that attackers can do + + + align:start position:0% +and another thing that attackers can do +is they can actually uh reuse captas on + + align:start position:0% +is they can actually uh reuse captas on + + + align:start position:0% +is they can actually uh reuse captas on +legitimate sites so there's a cap some + + align:start position:0% +legitimate sites so there's a cap some + + + align:start position:0% +legitimate sites so there's a cap some +capture that the attacker wants to solve + + align:start position:0% +capture that the attacker wants to solve + + + align:start position:0% +capture that the attacker wants to solve +they then have some legitimate site on + + align:start position:0% +they then have some legitimate site on + + + align:start position:0% +they then have some legitimate site on +the side where they present that exact + + align:start position:0% +the side where they present that exact + + + align:start position:0% +the side where they present that exact +same capture right and get like a real + + align:start position:0% +same capture right and get like a real + + + align:start position:0% +same capture right and get like a real +visitor to figure out what that capture + + align:start position:0% +visitor to figure out what that capture + + + align:start position:0% +visitor to figure out what that capture +is then they come back over to the first + + align:start position:0% +is then they come back over to the first + + + align:start position:0% +is then they come back over to the first +site and then use that answer um as the + + align:start position:0% +site and then use that answer um as the + + + align:start position:0% +site and then use that answer um as the +answer and like all these uh crowd + + align:start position:0% +answer and like all these uh crowd + + + align:start position:0% +answer and like all these uh crowd +sourcing type things if you don't trust + + align:start position:0% +sourcing type things if you don't trust + + + align:start position:0% +sourcing type things if you don't trust +your users then you can maybe you know + + align:start position:0% +your users then you can maybe you know + + + align:start position:0% +your users then you can maybe you know +replicate the work right so you send the + + align:start position:0% +replicate the work right so you send the + + + align:start position:0% +replicate the work right so you send the +capture maybe two or three people and + + align:start position:0% +capture maybe two or three people and + + + align:start position:0% +capture maybe two or three people and +then you come back in use majority + + align:start position:0% +then you come back in use majority + + + align:start position:0% +then you come back in use majority +voting and take whatever that majority + + align:start position:0% +voting and take whatever that majority + + + align:start position:0% +voting and take whatever that majority +vote was as your caption + + align:start position:0% +vote was as your caption + + + align:start position:0% +vote was as your caption +answer and so these are just some of the + + align:start position:0% +answer and so these are just some of the + + + align:start position:0% +answer and so these are just some of the +reasons why uh the capture defenses + + align:start position:0% +reasons why uh the capture defenses + + + align:start position:0% +reasons why uh the capture defenses +don't work as well as you might think um + + align:start position:0% +don't work as well as you might think um + + + align:start position:0% +don't work as well as you might think um +so the providers so for example Gmail or + + align:start position:0% +so the providers so for example Gmail or + + + align:start position:0% +so the providers so for example Gmail or +yahu or whatever could try to implement + + align:start position:0% +yahu or whatever could try to implement + + + align:start position:0% +yahu or whatever could try to implement +more frequent captures let's say to try + + align:start position:0% +more frequent captures let's say to try + + + align:start position:0% +more frequent captures let's say to try +to uh push the friction level up for the + + align:start position:0% +to uh push the friction level up for the + + + align:start position:0% +to uh push the friction level up for the +the the spammer the problem there is + + align:start position:0% +the the spammer the problem there is + + + align:start position:0% +the the spammer the problem there is +that then regular users will get + + align:start position:0% +that then regular users will get + + + align:start position:0% +that then regular users will get +irritated so you know a good example of + + align:start position:0% +irritated so you know a good example of + + + align:start position:0% +irritated so you know a good example of +this is a Gmail's two-factor + + align:start position:0% +this is a Gmail's two-factor + + + align:start position:0% +this is a Gmail's two-factor +authentication so it's actually a super + + align:start position:0% +authentication so it's actually a super + + + align:start position:0% +authentication so it's actually a super +good idea right so whenever Gmail will + + align:start position:0% +good idea right so whenever Gmail will + + + align:start position:0% +good idea right so whenever Gmail will +detect that you're trying to use Gmail + + align:start position:0% +detect that you're trying to use Gmail + + + align:start position:0% +detect that you're trying to use Gmail +from a machine that it doesn't uh know + + align:start position:0% +from a machine that it doesn't uh know + + + align:start position:0% +from a machine that it doesn't uh know +about it'll basically send you a text + + align:start position:0% +about it'll basically send you a text + + + align:start position:0% +about it'll basically send you a text +message and say hey enter this + + align:start position:0% +message and say hey enter this + + + align:start position:0% +message and say hey enter this +verification code um in the Gmail before + + align:start position:0% +verification code um in the Gmail before + + + align:start position:0% +verification code um in the Gmail before +you can actually continue to use the + + align:start position:0% +you can actually continue to use the + + + align:start position:0% +you can actually continue to use the +service and so what's funny is that it's + + align:start position:0% +service and so what's funny is that it's + + + align:start position:0% +service and so what's funny is that it's +a super great idea but like at least for + + align:start position:0% +a super great idea but like at least for + + + align:start position:0% +a super great idea but like at least for +me I get super irritated when I have to + + align:start position:0% +me I get super irritated when I have to + + + align:start position:0% +me I get super irritated when I have to +get that text message like I know it's + + align:start position:0% +get that text message like I know it's + + + align:start position:0% +get that text message like I know it's +good for me but I just get angry it's + + align:start position:0% +good for me but I just get angry it's + + + align:start position:0% +good for me but I just get angry it's +friction full and so I'll do it if I + + align:start position:0% +friction full and so I'll do it if I + + + align:start position:0% +friction full and so I'll do it if I +don't migrate to a lot of different + + align:start position:0% +don't migrate to a lot of different + + + align:start position:0% +don't migrate to a lot of different +machines a lot but like if I had to do + + align:start position:0% +machines a lot but like if I had to do + + + align:start position:0% +machines a lot but like if I had to do +it any more than I did right now it's + + align:start position:0% +it any more than I did right now it's + + + align:start position:0% +it any more than I did right now it's +unclear that you know I feel as happy + + align:start position:0% +unclear that you know I feel as happy + + + align:start position:0% +unclear that you know I feel as happy +about it as I do and so there's this + + align:start position:0% +about it as I do and so there's this + + + align:start position:0% +about it as I do and so there's this +very um interesting sort of trade-off + + align:start position:0% +very um interesting sort of trade-off + + + align:start position:0% +very um interesting sort of trade-off +between between the security that people + + align:start position:0% +between between the security that people + + + align:start position:0% +between between the security that people +say that they want and sort of the + + align:start position:0% +say that they want and sort of the + + + align:start position:0% +say that they want and sort of the +security measures that they're willing + + align:start position:0% +security measures that they're willing + + + align:start position:0% +security measures that they're willing +to put up with so as a result it's very + + align:start position:0% +to put up with so as a result it's very + + + align:start position:0% +to put up with so as a result it's very +difficult for the the web mail providers + + align:start position:0% +difficult for the the web mail providers + + + align:start position:0% +difficult for the the web mail providers +to increase the amount of capes and + + align:start position:0% +to increase the amount of capes and + + + align:start position:0% +to increase the amount of capes and +still keep users + + align:start position:0% +still keep users + + + align:start position:0% +still keep users +happy uh okay so any other questions + + align:start position:0% +happy uh okay so any other questions + + + align:start position:0% +happy uh okay so any other questions +before we move on to click support so so + + align:start position:0% +before we move on to click support so so + + + align:start position:0% +before we move on to click support so so +is one of the reasons for the + + align:start position:0% +is one of the reasons for the + + + align:start position:0% +is one of the reasons for the +non-adoption of encrypted email besides + + align:start position:0% +non-adoption of encrypted email besides + + + align:start position:0% +non-adoption of encrypted email besides +the P issue is that spam very very very + + align:start position:0% +the P issue is that spam very very very + + + align:start position:0% +the P issue is that spam very very very +part uh because then they can't do uh + + align:start position:0% +part uh because then they can't do uh + + + align:start position:0% +part uh because then they can't do uh +they can't inspect message and then see + + align:start position:0% +they can't inspect message and then see + + + align:start position:0% +they can't inspect message and then see +what's going on that's a good question I + + align:start position:0% +what's going on that's a good question I + + + align:start position:0% +what's going on that's a good question I +think it's it's actually hard to say I + + align:start position:0% +think it's it's actually hard to say I + + + align:start position:0% +think it's it's actually hard to say I +don't know because it's a little bit of + + align:start position:0% +don't know because it's a little bit of + + + align:start position:0% +don't know because it's a little bit of +a chicken and egg problem so because + + align:start position:0% +a chicken and egg problem so because + + + align:start position:0% +a chicken and egg problem so because +there isn't a huge volume of encrypted + + align:start position:0% +there isn't a huge volume of encrypted + + + align:start position:0% +there isn't a huge volume of encrypted +email uh it's unclear whether you know + + align:start position:0% +email uh it's unclear whether you know + + + align:start position:0% +email uh it's unclear whether you know +spammers would actually try to take + + align:start position:0% +spammers would actually try to take + + + align:start position:0% +spammers would actually try to take +advantage of that but I could see that + + align:start position:0% +advantage of that but I could see that + + + align:start position:0% +advantage of that but I could see that +maybe being a problem I mean people have + + align:start position:0% +maybe being a problem I mean people have + + + align:start position:0% +maybe being a problem I mean people have +looked at ways to do um sort of like + + align:start position:0% +looked at ways to do um sort of like + + + align:start position:0% +looked at ways to do um sort of like +computation over encrypted data so maybe + + align:start position:0% +computation over encrypted data so maybe + + + align:start position:0% +computation over encrypted data so maybe +you could think about doing something + + align:start position:0% +you could think about doing something + + + align:start position:0% +you could think about doing something +there but it's always tricky so for + + align:start position:0% +there but it's always tricky so for + + + align:start position:0% +there but it's always tricky so for +example like with Spam you know people + + align:start position:0% +example like with Spam you know people + + + align:start position:0% +example like with Spam you know people +have these spam filters that were based + + align:start position:0% +have these spam filters that were based + + + align:start position:0% +have these spam filters that were based +on um you Markov models and things like + + align:start position:0% +on um you Markov models and things like + + + align:start position:0% +on um you Markov models and things like +that so what do the spammers do they + + align:start position:0% +that so what do the spammers do they + + + align:start position:0% +that so what do the spammers do they +start making these images right that + + align:start position:0% +start making these images right that + + + align:start position:0% +start making these images right that +basically uh you know can't be seen by + + align:start position:0% +basically uh you know can't be seen by + + + align:start position:0% +basically uh you know can't be seen by +the text scanners but then have the + + align:start position:0% +the text scanners but then have the + + + align:start position:0% +the text scanners but then have the +spammy content in there so it's always + + align:start position:0% +spammy content in there so it's always + + + align:start position:0% +spammy content in there so it's always +an arms + + align:start position:0% + + + + align:start position:0% + +eras all right so let's move on to uh + + align:start position:0% +eras all right so let's move on to uh + + + align:start position:0% +eras all right so let's move on to uh +click + + align:start position:0% +click + + + align:start position:0% +click +support + + align:start position:0% +support + + + align:start position:0% +support +so what is this + + align:start position:0% +so what is this + + + align:start position:0% +so what is this +about so once the uh advertising step + + align:start position:0% +about so once the uh advertising step + + + align:start position:0% +about so once the uh advertising step +has succeeded and the user is given a + + align:start position:0% +has succeeded and the user is given a + + + align:start position:0% +has succeeded and the user is given a +link so the user clicks on that link so + + align:start position:0% +link so the user clicks on that link so + + + align:start position:0% +link so the user clicks on that link so +the user + + align:start position:0% +the user + + + align:start position:0% +the user +uh + + align:start position:0% +uh + + + align:start position:0% +uh +contacts uh some DNS server after + + align:start position:0% +contacts uh some DNS server after + + + align:start position:0% +contacts uh some DNS server after +clicking on that + + align:start position:0% +clicking on that + + + align:start position:0% +clicking on that +link uh to basically uh + + align:start position:0% +link uh to basically uh + + + align:start position:0% +link uh to basically uh +translate some host name that was in + + align:start position:0% +translate some host name that was in + + + align:start position:0% +translate some host name that was in +that uh link to uh some + + align:start position:0% +that uh link to uh some + + + align:start position:0% +that uh link to uh some +IP and then after that the after that + + align:start position:0% +IP and then after that the after that + + + align:start position:0% +IP and then after that the after that +translation takes place the user has to + + align:start position:0% +translation takes place the user has to + + + align:start position:0% +translation takes place the user has to +uh + + align:start position:0% +uh + + + align:start position:0% +uh +contact uh some web + + align:start position:0% + + + + align:start position:0% + +server that uh has that + + align:start position:0% +server that uh has that + + + align:start position:0% +server that uh has that +IP so to make all this work the spammer + + align:start position:0% +IP so to make all this work the spammer + + + align:start position:0% +IP so to make all this work the spammer +has to uh + + align:start position:0% + + + + align:start position:0% + +register a domain + + align:start position:0% +register a domain + + + align:start position:0% +register a domain +name and then the spammer has to run + + align:start position:0% +name and then the spammer has to run + + + align:start position:0% +name and then the spammer has to run +a a DNS + + align:start position:0% + + + + align:start position:0% + +server and then they have to run a web + + align:start position:0% + + + + align:start position:0% + +server so this is essentially what the + + align:start position:0% +server so this is essentially what the + + + align:start position:0% +server so this is essentially what the +spammer has to do to make this click + + align:start position:0% +spammer has to do to make this click + + + align:start position:0% +spammer has to do to make this click +support thing work out uh so one + + align:start position:0% +support thing work out uh so one + + + align:start position:0% +support thing work out uh so one +question you might have is well why why + + align:start position:0% +question you might have is well why why + + + align:start position:0% +question you might have is well why why +wouldn't the spammer just use raw IP + + align:start position:0% +wouldn't the spammer just use raw IP + + + align:start position:0% +wouldn't the spammer just use raw IP +addresses for example like in the spam + + align:start position:0% +addresses for example like in the spam + + + align:start position:0% +addresses for example like in the spam +URLs uh and so does anyone have any + + align:start position:0% +URLs uh and so does anyone have any + + + align:start position:0% +URLs uh and so does anyone have any +thoughts about that why would you just + + align:start position:0% +thoughts about that why would you just + + + align:start position:0% +thoughts about that why would you just +have just you + + align:start position:0% +have just you + + + align:start position:0% +have just you +know8 + + align:start position:0% +know8 + + + align:start position:0% +know8 +3.4.4 whatever instead of having + + align:start position:0% +3.4.4 whatever instead of having + + + align:start position:0% +3.4.4 whatever instead of having +something like you know Russian Jewels + + align:start position:0% +something like you know Russian Jewels + + + align:start position:0% +something like you know Russian Jewels +thatb yeah be sketchy easier to tell + + align:start position:0% +thatb yeah be sketchy easier to tell + + + align:start position:0% +thatb yeah be sketchy easier to tell +yeah so one thing one would hope right + + align:start position:0% +yeah so one thing one would hope right + + + align:start position:0% +yeah so one thing one would hope right +is that a user would look at this thing + + align:start position:0% +is that a user would look at this thing + + + align:start position:0% +is that a user would look at this thing +that just has a bunch of numbers in it + + align:start position:0% +that just has a bunch of numbers in it + + + align:start position:0% +that just has a bunch of numbers in it +and then you'd say well this clearly + + align:start position:0% +and then you'd say well this clearly + + + align:start position:0% +and then you'd say well this clearly +seems weird uh as it turns out this will + + align:start position:0% +seems weird uh as it turns out this will + + + align:start position:0% +seems weird uh as it turns out this will +only weed out some of the users but + + align:start position:0% +only weed out some of the users but + + + align:start position:0% +only weed out some of the users but +you're exactly right that there there's + + align:start position:0% +you're exactly right that there there's + + + align:start position:0% +you're exactly right that there there's +sort of like some set of people you + + align:start position:0% +sort of like some set of people you + + + align:start position:0% +sort of like some set of people you +would lose just because nobody wants to + + align:start position:0% +would lose just because nobody wants to + + + align:start position:0% +would lose just because nobody wants to +click on that um another reason is that + + align:start position:0% +click on that um another reason is that + + + align:start position:0% +click on that um another reason is that +once again having um this sort of DNS + + align:start position:0% +once again having um this sort of DNS + + + align:start position:0% +once again having um this sort of DNS +infrastructure up here gives the + + align:start position:0% +infrastructure up here gives the + + + align:start position:0% +infrastructure up here gives the +attacker another level of indirection + + align:start position:0% +attacker another level of indirection + + + align:start position:0% +attacker another level of indirection +right so once again if the legal + + align:start position:0% +right so once again if the legal + + + align:start position:0% +right so once again if the legal +authorities or whoever um shut down the + + align:start position:0% +authorities or whoever um shut down the + + + align:start position:0% +authorities or whoever um shut down the +DNS infrastructure but they somehow + + align:start position:0% +DNS infrastructure but they somehow + + + align:start position:0% +DNS infrastructure but they somehow +don't manage to shut down that backend + + align:start position:0% +don't manage to shut down that backend + + + align:start position:0% +don't manage to shut down that backend +web server then the spammer can sort of + + align:start position:0% +web server then the spammer can sort of + + + align:start position:0% +web server then the spammer can sort of +conjure up a different sort of front end + + align:start position:0% +conjure up a different sort of front end + + + align:start position:0% +conjure up a different sort of front end +for their service maybe try to use that + + align:start position:0% +for their service maybe try to use that + + + align:start position:0% +for their service maybe try to use that +same web server on the back end um so + + align:start position:0% +same web server on the back end um so + + + align:start position:0% +same web server on the back end um so +that's another reason I think that + + align:start position:0% +that's another reason I think that + + + align:start position:0% +that's another reason I think that +people don't uh typically put these raw + + align:start position:0% +people don't uh typically put these raw + + + align:start position:0% +people don't uh typically put these raw +uh IP addresses in their spam uh + + align:start position:0% +uh IP addresses in their spam uh + + + align:start position:0% +uh IP addresses in their spam uh +URLs + + align:start position:0% +URLs + + + align:start position:0% +URLs +so another example of how this uh + + align:start position:0% +so another example of how this uh + + + align:start position:0% +so another example of how this uh +redirection comes into play and how this + + align:start position:0% +redirection comes into play and how this + + + align:start position:0% +redirection comes into play and how this +indirection comes into play Sorry is + + align:start position:0% +indirection comes into play Sorry is + + + align:start position:0% +indirection comes into play Sorry is +that uh these uh spam + + align:start position:0% + + + + align:start position:0% + +URLs uh often point to uh redirection + + align:start position:0% + + + + align:start position:0% + +sites and so the uh redirectors and so + + align:start position:0% +sites and so the uh redirectors and so + + + align:start position:0% +sites and so the uh redirectors and so +these are sites like um you know bit.ly + + align:start position:0% +these are sites like um you know bit.ly + + + align:start position:0% +these are sites like um you know bit.ly +or things like that uh and so in + + align:start position:0% +or things like that uh and so in + + + align:start position:0% +or things like that uh and so in +addition to things like bitly you could + + align:start position:0% +addition to things like bitly you could + + + align:start position:0% +addition to things like bitly you could +also imagine that uh a compromise I + + align:start position:0% +also imagine that uh a compromise I + + + align:start position:0% +also imagine that uh a compromise I +website can actually also act as a + + align:start position:0% +website can actually also act as a + + + align:start position:0% +website can actually also act as a +redirector right so you just put um you + + align:start position:0% +redirector right so you just put um you + + + align:start position:0% +redirector right so you just put um you +know the appropriate uh HTML or + + align:start position:0% +know the appropriate uh HTML or + + + align:start position:0% +know the appropriate uh HTML or +JavaScript in there that when the user + + align:start position:0% +JavaScript in there that when the user + + + align:start position:0% +JavaScript in there that when the user +goes to that site it's then going to + + align:start position:0% +goes to that site it's then going to + + + align:start position:0% +goes to that site it's then going to +redirect the user's browser to some + + align:start position:0% +redirect the user's browser to some + + + align:start position:0% +redirect the user's browser to some +other different site and uh so once + + align:start position:0% +other different site and uh so once + + + align:start position:0% +other different site and uh so once +again this is useful because it provides + + align:start position:0% +again this is useful because it provides + + + align:start position:0% +again this is useful because it provides +that level of in Direction uh and it + + align:start position:0% +that level of in Direction uh and it + + + align:start position:0% +that level of in Direction uh and it +actually it acts as a force multiplier + + align:start position:0% +actually it acts as a force multiplier + + + align:start position:0% +actually it acts as a force multiplier +so you have a single um you know sort of + + align:start position:0% +so you have a single um you know sort of + + + align:start position:0% +so you have a single um you know sort of +spammy web server back end but then you + + align:start position:0% +spammy web server back end but then you + + + align:start position:0% +spammy web server back end but then you +can sort of name it using different + + align:start position:0% +can sort of name it using different + + + align:start position:0% +can sort of name it using different +different things and that will allow you + + align:start position:0% +different things and that will allow you + + + align:start position:0% +different things and that will allow you +to maybe um confuse uh filters who have + + align:start position:0% +to maybe um confuse uh filters who have + + + align:start position:0% +to maybe um confuse uh filters who have +blacklisted let's say 10% of your Earls + + align:start position:0% +blacklisted let's say 10% of your Earls + + + align:start position:0% +blacklisted let's say 10% of your Earls +but not you know the other 90% of them + + align:start position:0% +but not you know the other 90% of them + + + align:start position:0% +but not you know the other 90% of them +so this is a very very common technique + + align:start position:0% +so this is a very very common technique + + + align:start position:0% +so this is a very very common technique +um and then another thing is that uh + + align:start position:0% +um and then another thing is that uh + + + align:start position:0% +um and then another thing is that uh +sometimes uh the spammers can use uh + + align:start position:0% +sometimes uh the spammers can use uh + + + align:start position:0% +sometimes uh the spammers can use uh +botn + + align:start position:0% + + + + align:start position:0% + +Nets as web + + align:start position:0% + + + + align:start position:0% + +servers or maybe as proxies as DNS + + align:start position:0% +servers or maybe as proxies as DNS + + + align:start position:0% +servers or maybe as proxies as DNS +servers you know so on and so forth uh + + align:start position:0% +servers you know so on and so forth uh + + + align:start position:0% +servers you know so on and so forth uh +and so we mentioned this a little bit + + align:start position:0% +and so we mentioned this a little bit + + + align:start position:0% +and so we mentioned this a little bit +earlier but this is just another example + + align:start position:0% +earlier but this is just another example + + + align:start position:0% +earlier but this is just another example +of the more machines that you have as an + + align:start position:0% +of the more machines that you have as an + + + align:start position:0% +of the more machines that you have as an +attacker the more defense that gives you + + align:start position:0% +attacker the more defense that gives you + + + align:start position:0% +attacker the more defense that gives you +because you can sort of hide your evil + + align:start position:0% +because you can sort of hide your evil + + + align:start position:0% +because you can sort of hide your evil +amongst a larger set of + + align:start position:0% + + + + align:start position:0% + +machines all + + align:start position:0% + + + + align:start position:0% + +right so in some cases so one thing the + + align:start position:0% +right so in some cases so one thing the + + + align:start position:0% +right so in some cases so one thing the +paper talks about is these affiliate + + align:start position:0% +paper talks about is these affiliate + + + align:start position:0% +paper talks about is these affiliate +providers so these affiliate providers + + align:start position:0% +providers so these affiliate providers + + + align:start position:0% +providers so these affiliate providers +kind of act as um sort of evil Clearing + + align:start position:0% +kind of act as um sort of evil Clearing + + + align:start position:0% +kind of act as um sort of evil Clearing +Houses so they will help to automate + + align:start position:0% +Houses so they will help to automate + + + align:start position:0% +Houses so they will help to automate +some of the tedium of interacting with + + align:start position:0% +some of the tedium of interacting with + + + align:start position:0% +some of the tedium of interacting with +the banks and and things like this on + + align:start position:0% +the banks and and things like this on + + + align:start position:0% +the banks and and things like this on +behalf of you the spammer uh so one + + align:start position:0% +behalf of you the spammer uh so one + + + align:start position:0% +behalf of you the spammer uh so one +thing you might wonder is well why can't + + align:start position:0% +thing you might wonder is well why can't + + + align:start position:0% +thing you might wonder is well why can't +the law enforcement just take down the + + align:start position:0% +the law enforcement just take down the + + + align:start position:0% +the law enforcement just take down the +affiliate provider they seem kind of + + align:start position:0% +affiliate provider they seem kind of + + + align:start position:0% +affiliate provider they seem kind of +like a choke point and the thing is that + + align:start position:0% +like a choke point and the thing is that + + + align:start position:0% +like a choke point and the thing is that +these affiliate providers they're kind + + align:start position:0% +these affiliate providers they're kind + + + align:start position:0% +these affiliate providers they're kind +of like uh like Spectre from the James + + align:start position:0% +of like uh like Spectre from the James + + + align:start position:0% +of like uh like Spectre from the James +Bond movies like they're very + + align:start position:0% +Bond movies like they're very + + + align:start position:0% +Bond movies like they're very +decentralized themselves right so it's + + align:start position:0% +decentralized themselves right so it's + + + align:start position:0% +decentralized themselves right so it's +very difficult to point to you know an + + align:start position:0% +very difficult to point to you know an + + + align:start position:0% +very difficult to point to you know an +affiliate provider at this particular + + align:start position:0% +affiliate provider at this particular + + + align:start position:0% +affiliate provider at this particular +machine and we'll just shut down that + + align:start position:0% +machine and we'll just shut down that + + + align:start position:0% +machine and we'll just shut down that +that particular machine often times the + + align:start position:0% +that particular machine often times the + + + align:start position:0% +that particular machine often times the +affiliate providers are distributed + + align:start position:0% +affiliate providers are distributed + + + align:start position:0% +affiliate providers are distributed +themselves and so that means that it's + + align:start position:0% +themselves and so that means that it's + + + align:start position:0% +themselves and so that means that it's +actually pretty tricky for let's say the + + align:start position:0% +actually pretty tricky for let's say the + + + align:start position:0% +actually pretty tricky for let's say the +FBI just go to uh some affiliate program + + align:start position:0% +FBI just go to uh some affiliate program + + + align:start position:0% +FBI just go to uh some affiliate program +and say you know Thou shalt not do this + + align:start position:0% +and say you know Thou shalt not do this + + + align:start position:0% +and say you know Thou shalt not do this +anymore uh and another interesting thing + + align:start position:0% +anymore uh and another interesting thing + + + align:start position:0% +anymore uh and another interesting thing +too is that the paper mentions that uh + + align:start position:0% +too is that the paper mentions that uh + + + align:start position:0% +too is that the paper mentions that uh +in many countries IP laws are different + + align:start position:0% +in many countries IP laws are different + + + align:start position:0% +in many countries IP laws are different +for example so the FBI may not be able + + align:start position:0% +for example so the FBI may not be able + + + align:start position:0% +for example so the FBI may not be able +to enforce intellectual property + + align:start position:0% +to enforce intellectual property + + + align:start position:0% +to enforce intellectual property +treaties that we have with other + + align:start position:0% +treaties that we have with other + + + align:start position:0% +treaties that we have with other +countries and also according to the + + align:start position:0% +countries and also according to the + + + align:start position:0% +countries and also according to the +paper in many of these spam forums the + + align:start position:0% +paper in many of these spam forums the + + + align:start position:0% +paper in many of these spam forums the +spammers claim that they are providing a + + align:start position:0% +spammers claim that they are providing a + + + align:start position:0% +spammers claim that they are providing a +useful legitimate service to Western + + align:start position:0% +useful legitimate service to Western + + + align:start position:0% +useful legitimate service to Western +countries they say that essentially you + + align:start position:0% +countries they say that essentially you + + + align:start position:0% +countries they say that essentially you +know prices are too high for some of + + align:start position:0% +know prices are too high for some of + + + align:start position:0% +know prices are too high for some of +these things in these Western countries + + align:start position:0% +these things in these Western countries + + + align:start position:0% +these things in these Western countries +and that the fact that people are + + align:start position:0% +and that the fact that people are + + + align:start position:0% +and that the fact that people are +clicking on spam indicates there's a + + align:start position:0% +clicking on spam indicates there's a + + + align:start position:0% +clicking on spam indicates there's a +legitimate need to you know buy Windows + + align:start position:0% +legitimate need to you know buy Windows + + + align:start position:0% +legitimate need to you know buy Windows +copies that may be riddled with malware + + align:start position:0% +copies that may be riddled with malware + + + align:start position:0% +copies that may be riddled with malware +right and so a lot of times the spammers + + align:start position:0% +right and so a lot of times the spammers + + + align:start position:0% +right and so a lot of times the spammers +themselves don't feel that they're doing + + align:start position:0% +themselves don't feel that they're doing + + + align:start position:0% +themselves don't feel that they're doing +anything bad and as we'll discuss a + + align:start position:0% +anything bad and as we'll discuss a + + + align:start position:0% +anything bad and as we'll discuss a +little bit later the spammers do often + + align:start position:0% +little bit later the spammers do often + + + align:start position:0% +little bit later the spammers do often +actually give you the stuff that you've + + align:start position:0% +actually give you the stuff that you've + + + align:start position:0% +actually give you the stuff that you've +paid money for which for me was one of + + align:start position:0% +paid money for which for me was one of + + + align:start position:0% +paid money for which for me was one of +the most surprising outcomes of the + + align:start position:0% +the most surprising outcomes of the + + + align:start position:0% +the most surprising outcomes of the +paper uh and so we'll discuss why that + + align:start position:0% +paper uh and so we'll discuss why that + + + align:start position:0% +paper uh and so we'll discuss why that +is uh in a little bit so uh one thing + + align:start position:0% +is uh in a little bit so uh one thing + + + align:start position:0% +is uh in a little bit so uh one thing +the paper talks about is um sort of + + align:start position:0% +the paper talks about is um sort of + + + align:start position:0% +the paper talks about is um sort of +various takeown strategies that you can + + align:start position:0% +various takeown strategies that you can + + + align:start position:0% +various takeown strategies that you can +imagine employing um to try to uh stop a + + align:start position:0% +imagine employing um to try to uh stop a + + + align:start position:0% +imagine employing um to try to uh stop a +spammer so one thing I talked about they + + align:start position:0% +spammer so one thing I talked about they + + + align:start position:0% +spammer so one thing I talked about they +said that + + align:start position:0% +said that + + + align:start position:0% +said that +uh only a uh few + + align:start position:0% + + + + align:start position:0% + +number of uh + + align:start position:0% + + + + align:start position:0% + +registar host domain means for many + + align:start position:0% + + + + align:start position:0% + +Affiliates and so what that means is + + align:start position:0% +Affiliates and so what that means is + + + align:start position:0% +Affiliates and so what that means is +that most of + + align:start position:0% +that most of + + + align:start position:0% +that most of +these uh affiliate + + align:start position:0% +these uh affiliate + + + align:start position:0% +these uh affiliate +programs are there's sort of like this + + align:start position:0% +programs are there's sort of like this + + + align:start position:0% +programs are there's sort of like this +onetoone binding between Affiliates and + + align:start position:0% +onetoone binding between Affiliates and + + + align:start position:0% +onetoone binding between Affiliates and +the register stars that are dealing with + + align:start position:0% +the register stars that are dealing with + + + align:start position:0% +the register stars that are dealing with +their domain name infrastructure right + + align:start position:0% +their domain name infrastructure right + + + align:start position:0% +their domain name infrastructure right +it's very rare that you have a single + + align:start position:0% +it's very rare that you have a single + + + align:start position:0% +it's very rare that you have a single +domain name uh registar who's going to + + align:start position:0% +domain name uh registar who's going to + + + align:start position:0% +domain name uh registar who's going to +be associated with a bunch of different + + align:start position:0% +be associated with a bunch of different + + + align:start position:0% +be associated with a bunch of different +affiliate programs so what that means is + + align:start position:0% +affiliate programs so what that means is + + + align:start position:0% +affiliate programs so what that means is +that in many cases there's not sort of + + align:start position:0% +that in many cases there's not sort of + + + align:start position:0% +that in many cases there's not sort of +like this master decapitation strike you + + align:start position:0% +like this master decapitation strike you + + + align:start position:0% +like this master decapitation strike you +could launch you take out this + + align:start position:0% +could launch you take out this + + + align:start position:0% +could launch you take out this +particular registar and then all of a + + align:start position:0% +particular registar and then all of a + + + align:start position:0% +particular registar and then all of a +sudden like the entire spam + + align:start position:0% +sudden like the entire spam + + + align:start position:0% +sudden like the entire spam +infrastructure falls down right and so + + align:start position:0% +infrastructure falls down right and so + + + align:start position:0% +infrastructure falls down right and so +they found similar results uh for things + + align:start position:0% +they found similar results uh for things + + + align:start position:0% +they found similar results uh for things +like + + align:start position:0% +like + + + align:start position:0% +like +uh uh like web servers so it's very rare + + align:start position:0% +uh uh like web servers so it's very rare + + + align:start position:0% +uh uh like web servers so it's very rare +that one ISP will actually host a ton of + + align:start position:0% +that one ISP will actually host a ton of + + + align:start position:0% +that one ISP will actually host a ton of +web servers for a ton of different + + align:start position:0% +web servers for a ton of different + + + align:start position:0% +web servers for a ton of different +affiliate programs right so this + + align:start position:0% +affiliate programs right so this + + + align:start position:0% +affiliate programs right so this +distributed nature once again makes it + + align:start position:0% +distributed nature once again makes it + + + align:start position:0% +distributed nature once again makes it +very difficult to just say if we just do + + align:start position:0% +very difficult to just say if we just do + + + align:start position:0% +very difficult to just say if we just do +if we take out these these three things + + align:start position:0% +if we take out these these three things + + + align:start position:0% +if we take out these these three things +then the whole ecosystem just crumbles + + align:start position:0% +then the whole ecosystem just crumbles + + + align:start position:0% +then the whole ecosystem just crumbles +um so that's a little bit disappointing + + align:start position:0% +um so that's a little bit disappointing + + + align:start position:0% +um so that's a little bit disappointing +right because one would have hoped that + + align:start position:0% +right because one would have hoped that + + + align:start position:0% +right because one would have hoped that +there would be you know one web server + + align:start position:0% +there would be you know one web server + + + align:start position:0% +there would be you know one web server +in evilonia where if we could just take + + align:start position:0% +in evilonia where if we could just take + + + align:start position:0% +in evilonia where if we could just take +down evilonia then people would stop + + align:start position:0% +down evilonia then people would stop + + + align:start position:0% +down evilonia then people would stop +sending us spam that's actually not true + + align:start position:0% +sending us spam that's actually not true + + + align:start position:0% +sending us spam that's actually not true +as we'll see later though that may be + + align:start position:0% +as we'll see later though that may be + + + align:start position:0% +as we'll see later though that may be +true with some of the banking back in + + align:start position:0% +true with some of the banking back in + + + align:start position:0% +true with some of the banking back in +though and so maybe we can actually put + + align:start position:0% +though and so maybe we can actually put + + + align:start position:0% +though and so maybe we can actually put +the squeeze on there so anyways uh I was + + align:start position:0% +the squeeze on there so anyways uh I was + + + align:start position:0% +the squeeze on there so anyways uh I was +alluding to earlier about this this + + align:start position:0% +alluding to earlier about this this + + + align:start position:0% +alluding to earlier about this this +realization + + align:start position:0% +realization + + + align:start position:0% +realization +phase so the realization phase is what + + align:start position:0% +phase so the realization phase is what + + + align:start position:0% +phase so the realization phase is what +happens after uh you the user have + + align:start position:0% +happens after uh you the user have + + + align:start position:0% +happens after uh you the user have +decided to um buy something so the + + align:start position:0% +decided to um buy something so the + + + align:start position:0% +decided to um buy something so the +realization phase consists of two parts + + align:start position:0% +realization phase consists of two parts + + + align:start position:0% +realization phase consists of two parts +so the user uh pays for whatever Goods + + align:start position:0% +so the user uh pays for whatever Goods + + + align:start position:0% +so the user uh pays for whatever Goods +they've bought or they want to buy and + + align:start position:0% +they've bought or they want to buy and + + + align:start position:0% +they've bought or they want to buy and +then the user + + align:start position:0% +then the user + + + align:start position:0% +then the user +hopefully uh will + + align:start position:0% +hopefully uh will + + + align:start position:0% +hopefully uh will +receive those goods so either in the + + align:start position:0% +receive those goods so either in the + + + align:start position:0% +receive those goods so either in the +mail because they're buying uh you know + + align:start position:0% +mail because they're buying uh you know + + + align:start position:0% +mail because they're buying uh you know +some type of knockoff drug or either um + + align:start position:0% +some type of knockoff drug or either um + + + align:start position:0% +some type of knockoff drug or either um +they get some forare download because + + align:start position:0% +they get some forare download because + + + align:start position:0% +they get some forare download because +they want to get some fake version of + + align:start position:0% +they want to get some fake version of + + + align:start position:0% +they want to get some fake version of +Photoshop or something like that and so + + align:start position:0% +Photoshop or something like that and so + + + align:start position:0% +Photoshop or something like that and so +the money flow looks something like this + + align:start position:0% +the money flow looks something like this + + + align:start position:0% +the money flow looks something like this +so you start with the customer + + align:start position:0% +so you start with the customer + + + align:start position:0% +so you start with the customer +here then they are going to uh tell the + + align:start position:0% +here then they are going to uh tell the + + + align:start position:0% +here then they are going to uh tell the +merchant hey I want to go um buy + + align:start position:0% +merchant hey I want to go um buy + + + align:start position:0% +merchant hey I want to go um buy +something they will send some uh credit + + align:start position:0% +something they will send some uh credit + + + align:start position:0% +something they will send some uh credit +card info here then we're the Merchant's + + align:start position:0% +card info here then we're the Merchant's + + + align:start position:0% +card info here then we're the Merchant's +going to talk to the payment + + align:start position:0% +going to talk to the payment + + + align:start position:0% +going to talk to the payment +processor and this is essentially a + + align:start position:0% +processor and this is essentially a + + + align:start position:0% +processor and this is essentially a +middleman that + + align:start position:0% +middleman that + + + align:start position:0% +middleman that +uh helps the merchant uh the spammer + + align:start position:0% +uh helps the merchant uh the spammer + + + align:start position:0% +uh helps the merchant uh the spammer +deal with some of the intricacies of of + + align:start position:0% +deal with some of the intricacies of of + + + align:start position:0% +deal with some of the intricacies of of +interacting with the credit card + + align:start position:0% +interacting with the credit card + + + align:start position:0% +interacting with the credit card +system the payment processor will talk + + align:start position:0% +system the payment processor will talk + + + align:start position:0% +system the payment processor will talk +to the uh acquiring + + align:start position:0% + + + + align:start position:0% + +bank so the acquiring bank that's the + + align:start position:0% +bank so the acquiring bank that's the + + + align:start position:0% +bank so the acquiring bank that's the +Merchants + + align:start position:0% + + + + align:start position:0% + +Bank and then the acquiring Bank let's + + align:start position:0% +Bank and then the acquiring Bank let's + + + align:start position:0% +Bank and then the acquiring Bank let's +see running out of space here so uh + + align:start position:0% +see running out of space here so uh + + + align:start position:0% +see running out of space here so uh +violating all good design standards we + + align:start position:0% +violating all good design standards we + + + align:start position:0% +violating all good design standards we +will come up here uh so the acquiring + + align:start position:0% +will come up here uh so the acquiring + + + align:start position:0% +will come up here uh so the acquiring +bank is going to talk to they call in + + align:start position:0% +bank is going to talk to they call in + + + align:start position:0% +bank is going to talk to they call in +the in the paper the uh Association + + align:start position:0% +the in the paper the uh Association + + + align:start position:0% +the in the paper the uh Association +network but I mean just think of this as + + align:start position:0% +network but I mean just think of this as + + + align:start position:0% +network but I mean just think of this as +you know for example Visa this is this + + align:start position:0% +you know for example Visa this is this + + + align:start position:0% +you know for example Visa this is this +is the credit card Network up + + align:start position:0% +is the credit card Network up + + + align:start position:0% +is the credit card Network up +here and then finally the association + + align:start position:0% +here and then finally the association + + + align:start position:0% +here and then finally the association +Network Visa Mastercard whatever talks + + align:start position:0% +Network Visa Mastercard whatever talks + + + align:start position:0% +Network Visa Mastercard whatever talks +to + + align:start position:0% +to + + + align:start position:0% +to +the issuing + + align:start position:0% +the issuing + + + align:start position:0% +the issuing +bank and so that issuing bank is the + + align:start position:0% +bank and so that issuing bank is the + + + align:start position:0% +bank and so that issuing bank is the +customers bank and essentially the uh + + align:start position:0% +customers bank and essentially the uh + + + align:start position:0% +customers bank and essentially the uh +Visa or whoever is going to go to the + + align:start position:0% +Visa or whoever is going to go to the + + + align:start position:0% +Visa or whoever is going to go to the +customer bank and say hey is this a + + align:start position:0% +customer bank and say hey is this a + + + align:start position:0% +customer bank and say hey is this a +legit purchase this is a legit + + align:start position:0% +legit purchase this is a legit + + + align:start position:0% +legit purchase this is a legit +transaction and if this is a legit + + align:start position:0% +transaction and if this is a legit + + + align:start position:0% +transaction and if this is a legit +transaction then the money will actually + + align:start position:0% +transaction then the money will actually + + + align:start position:0% +transaction then the money will actually +flow through this entire system right so + + align:start position:0% +flow through this entire system right so + + + align:start position:0% +flow through this entire system right so +this is kind of like what the end to end + + align:start position:0% +this is kind of like what the end to end + + + align:start position:0% +this is kind of like what the end to end +uh Financial uh sort of workflow looks + + align:start position:0% +uh Financial uh sort of workflow looks + + + align:start position:0% +uh Financial uh sort of workflow looks +like and so this workflow can actually + + align:start position:0% +like and so this workflow can actually + + + align:start position:0% +like and so this workflow can actually +process a lot of money so one of the + + align:start position:0% +process a lot of money so one of the + + + align:start position:0% +process a lot of money so one of the +papers um that we mentioned in the + + align:start position:0% +papers um that we mentioned in the + + + align:start position:0% +papers um that we mentioned in the +lecture notes shows that you can + + align:start position:0% +lecture notes shows that you can + + + align:start position:0% +lecture notes shows that you can +actually a single affiliate can get more + + align:start position:0% +actually a single affiliate can get more + + + align:start position:0% +actually a single affiliate can get more +than you know $10 million at this + + align:start position:0% +than you know $10 million at this + + + align:start position:0% +than you know $10 million at this +workflow here right and so in practice + + align:start position:0% +workflow here right and so in practice + + + align:start position:0% +workflow here right and so in practice +uh you might think that oh why wouldn't + + align:start position:0% +uh you might think that oh why wouldn't + + + align:start position:0% +uh you might think that oh why wouldn't +the you know acquiring bank or the + + align:start position:0% +the you know acquiring bank or the + + + align:start position:0% +the you know acquiring bank or the +issuing Bank say ah something looks kind + + align:start position:0% +issuing Bank say ah something looks kind + + + align:start position:0% +issuing Bank say ah something looks kind +of fishy here uh as it turns out in many + + align:start position:0% +of fishy here uh as it turns out in many + + + align:start position:0% +of fishy here uh as it turns out in many +cases um they don't and so this gets + + align:start position:0% +cases um they don't and so this gets + + + align:start position:0% +cases um they don't and so this gets +this interesting discussion + + align:start position:0% +this interesting discussion + + + align:start position:0% +this interesting discussion +about + + align:start position:0% +about + + + align:start position:0% +about +uh why is it that these workflows are + + align:start position:0% +uh why is it that these workflows are + + + align:start position:0% +uh why is it that these workflows are +often tolerated by the financial system + + align:start position:0% +often tolerated by the financial system + + + align:start position:0% +often tolerated by the financial system +so for example so why uh do + + align:start position:0% + + + + align:start position:0% + +spammers properly classified their + + align:start position:0% + + + + align:start position:0% + +transactions so if you want to send + + align:start position:0% +transactions so if you want to send + + + align:start position:0% +transactions so if you want to send +something through uh this system you + + align:start position:0% +something through uh this system you + + + align:start position:0% +something through uh this system you +have to tag that transaction with some + + align:start position:0% +have to tag that transaction with some + + + align:start position:0% +have to tag that transaction with some +type of of type you have to say this is + + align:start position:0% +type of of type you have to say this is + + + align:start position:0% +type of of type you have to say this is +Pharmaceuticals this is software this is + + align:start position:0% +Pharmaceuticals this is software this is + + + align:start position:0% +Pharmaceuticals this is software this is +whatever this is whatever so you might + + align:start position:0% +whatever this is whatever so you might + + + align:start position:0% +whatever this is whatever so you might +think that as a spammer you wouldn't + + align:start position:0% +think that as a spammer you wouldn't + + + align:start position:0% +think that as a spammer you wouldn't +actually want to do this like if you + + align:start position:0% +actually want to do this like if you + + + align:start position:0% +actually want to do this like if you +were selling you know fake Flintstone + + align:start position:0% +were selling you know fake Flintstone + + + align:start position:0% +were selling you know fake Flintstone +vitamins maybe you don't want to say + + align:start position:0% +vitamins maybe you don't want to say + + + align:start position:0% +vitamins maybe you don't want to say +like this is actually a pharmaceutical + + align:start position:0% +like this is actually a pharmaceutical + + + align:start position:0% +like this is actually a pharmaceutical +trans transaction uh what's interesting + + align:start position:0% +trans transaction uh what's interesting + + + align:start position:0% +trans transaction uh what's interesting +is that spammers do actually properly + + align:start position:0% +is that spammers do actually properly + + + align:start position:0% +is that spammers do actually properly +classify these transactions in many + + align:start position:0% +classify these transactions in many + + + align:start position:0% +classify these transactions in many +cases and the reason is that there are + + align:start position:0% +cases and the reason is that there are + + + align:start position:0% +cases and the reason is that there are +high + + align:start position:0% + + + + align:start position:0% + +finds uh if you + + align:start position:0% + + + + align:start position:0% + +misclassify so essentially what happens + + align:start position:0% +misclassify so essentially what happens + + + align:start position:0% +misclassify so essentially what happens +is + + align:start position:0% +is + + + align:start position:0% +is +that uh you know these Association + + align:start position:0% +that uh you know these Association + + + align:start position:0% +that uh you know these Association +networks like Visa + + align:start position:0% +networks like Visa + + + align:start position:0% +networks like Visa +Mastercard in many cases they are okay + + align:start position:0% +Mastercard in many cases they are okay + + + align:start position:0% +Mastercard in many cases they are okay +perhaps with transactions that are + + align:start position:0% +perhaps with transactions that are + + + align:start position:0% +perhaps with transactions that are +slightly Shady but but they don't want + + align:start position:0% +slightly Shady but but they don't want + + + align:start position:0% +slightly Shady but but they don't want +to be blamed for like being a money + + align:start position:0% +to be blamed for like being a money + + + align:start position:0% +to be blamed for like being a money +launderer or for trying to deceive the + + align:start position:0% +launderer or for trying to deceive the + + + align:start position:0% +launderer or for trying to deceive the +authorities so as long as you properly + + align:start position:0% +authorities so as long as you properly + + + align:start position:0% +authorities so as long as you properly +classify what you do then in a certain + + align:start position:0% +classify what you do then in a certain + + + align:start position:0% +classify what you do then in a certain +sance this gives the trans the the + + align:start position:0% +sance this gives the trans the the + + + align:start position:0% +sance this gives the trans the the +association networks a little bit of + + align:start position:0% +association networks a little bit of + + + align:start position:0% +association networks a little bit of +like well listen they told us what was + + align:start position:0% +like well listen they told us what was + + + align:start position:0% +like well listen they told us what was +going on maybe the law was a little bit + + align:start position:0% +going on maybe the law was a little bit + + + align:start position:0% +going on maybe the law was a little bit +unclear but we at least Visa MasterCards + + align:start position:0% +unclear but we at least Visa MasterCards + + + align:start position:0% +unclear but we at least Visa MasterCards +do not try to hide the intent of this + + align:start position:0% +do not try to hide the intent of this + + + align:start position:0% +do not try to hide the intent of this +transaction right so spamers do often + + align:start position:0% +transaction right so spamers do often + + + align:start position:0% +transaction right so spamers do often +times properly classify their + + align:start position:0% +times properly classify their + + + align:start position:0% +times properly classify their +transactions um so that's interesting so + + align:start position:0% +transactions um so that's interesting so + + + align:start position:0% +transactions um so that's interesting so +it seems like they're playing within the + + align:start position:0% +it seems like they're playing within the + + + align:start position:0% +it seems like they're playing within the +confines of the system a little bit so + + align:start position:0% +confines of the system a little bit so + + + align:start position:0% +confines of the system a little bit so +another question that I mentioned + + align:start position:0% +another question that I mentioned + + + align:start position:0% +another question that I mentioned +earlier is + + align:start position:0% +earlier is + + + align:start position:0% +earlier is +so why send anything to + + align:start position:0% + + + + align:start position:0% + +users because presumably you're a + + align:start position:0% +users because presumably you're a + + + align:start position:0% +users because presumably you're a +spammer so you're a criminal right so + + align:start position:0% +spammer so you're a criminal right so + + + align:start position:0% +spammer so you're a criminal right so +why I wouldn't it just be cool if you + + align:start position:0% +why I wouldn't it just be cool if you + + + align:start position:0% +why I wouldn't it just be cool if you +just like took people's money and then + + align:start position:0% +just like took people's money and then + + + align:start position:0% +just like took people's money and then +just ran I mean that'd be like the + + align:start position:0% +just ran I mean that'd be like the + + + align:start position:0% +just ran I mean that'd be like the +ultimate crime right so as it turns out + + align:start position:0% +ultimate crime right so as it turns out + + + align:start position:0% +ultimate crime right so as it turns out +um they actually send things to users uh + + align:start position:0% +um they actually send things to users uh + + + align:start position:0% +um they actually send things to users uh +because of surprise surprise High fines + + align:start position:0% +because of surprise surprise High fines + + + align:start position:0% +because of surprise surprise High fines +if they + + align:start position:0% +if they + + + align:start position:0% +if they +don't right so it's this very + + align:start position:0% +don't right so it's this very + + + align:start position:0% +don't right so it's this very +entertaining system whereby spammers + + align:start position:0% +entertaining system whereby spammers + + + align:start position:0% +entertaining system whereby spammers +kind of want to do things that are + + align:start position:0% +kind of want to do things that are + + + align:start position:0% +kind of want to do things that are +illegal then they actually can't use + + align:start position:0% +illegal then they actually can't use + + + align:start position:0% +illegal then they actually can't use +Bitcoins yet you know and they actually + + align:start position:0% +Bitcoins yet you know and they actually + + + align:start position:0% +Bitcoins yet you know and they actually +have to work within the the constraints + + align:start position:0% +have to work within the the constraints + + + align:start position:0% +have to work within the the constraints +of this pre-existing system so as it + + align:start position:0% +of this pre-existing system so as it + + + align:start position:0% +of this pre-existing system so as it +turns out um there are these high fines + + align:start position:0% +turns out um there are these high fines + + + align:start position:0% +turns out um there are these high fines +if uh you so where you I mean the + + align:start position:0% +if uh you so where you I mean the + + + align:start position:0% +if uh you so where you I mean the +spammer uh have too many + + align:start position:0% + + + + align:start position:0% + +chargebacks so a charge back is + + align:start position:0% +chargebacks so a charge back is + + + align:start position:0% +chargebacks so a charge back is +essentially when a uh customer tells + + align:start position:0% +essentially when a uh customer tells + + + align:start position:0% +essentially when a uh customer tells +their credit card company hey I didn't + + align:start position:0% +their credit card company hey I didn't + + + align:start position:0% +their credit card company hey I didn't +get the thing that I was supposed to get + + align:start position:0% +get the thing that I was supposed to get + + + align:start position:0% +get the thing that I was supposed to get +uh that I bought with your credit card + + align:start position:0% +uh that I bought with your credit card + + + align:start position:0% +uh that I bought with your credit card +or I got it but they didn't like it + + align:start position:0% +or I got it but they didn't like it + + + align:start position:0% +or I got it but they didn't like it +right so if you're a spammer and you + + align:start position:0% +right so if you're a spammer and you + + + align:start position:0% +right so if you're a spammer and you +have too many customers saying things + + align:start position:0% +have too many customers saying things + + + align:start position:0% +have too many customers saying things +like this then you will actually get + + align:start position:0% +like this then you will actually get + + + align:start position:0% +like this then you will actually get +charged like very very high fines and as + + align:start position:0% +charged like very very high fines and as + + + align:start position:0% +charged like very very high fines and as +we saw uh earlier the uh the + + align:start position:0% +we saw uh earlier the uh the + + + align:start position:0% +we saw uh earlier the uh the +click-through rates for spam are super + + align:start position:0% +click-through rates for spam are super + + + align:start position:0% +click-through rates for spam are super +super low right the conversion rates are + + align:start position:0% +super low right the conversion rates are + + + align:start position:0% +super low right the conversion rates are +super super low + + align:start position:0% +super super low + + + align:start position:0% +super super low +so you know even just one or two fines + + align:start position:0% +so you know even just one or two fines + + + align:start position:0% +so you know even just one or two fines +might wipe out your entire profit for a + + align:start position:0% +might wipe out your entire profit for a + + + align:start position:0% +might wipe out your entire profit for a +month let's say or something like this + + align:start position:0% +month let's say or something like this + + + align:start position:0% +month let's say or something like this +so spammers are really motivated to + + align:start position:0% +so spammers are really motivated to + + + align:start position:0% +so spammers are really motivated to +avoid these fines in both cases do you + + align:start position:0% +avoid these fines in both cases do you + + + align:start position:0% +avoid these fines in both cases do you +think PayPal obscure any of that like + + align:start position:0% +think PayPal obscure any of that like + + + align:start position:0% +think PayPal obscure any of that like +issuing bang uh T So typically well so + + align:start position:0% +issuing bang uh T So typically well so + + + align:start position:0% +issuing bang uh T So typically well so +yes and no so you can think of those + + align:start position:0% +yes and no so you can think of those + + + align:start position:0% +yes and no so you can think of those +PayPal is in many respects very similar + + align:start position:0% +PayPal is in many respects very similar + + + align:start position:0% +PayPal is in many respects very similar +to Visa or Mastercard right so it has + + align:start position:0% +to Visa or Mastercard right so it has + + + align:start position:0% +to Visa or Mastercard right so it has +very similar regulations that um sort of + + align:start position:0% +very similar regulations that um sort of + + + align:start position:0% +very similar regulations that um sort of +oversee it because it Bears many the + + align:start position:0% +oversee it because it Bears many the + + + align:start position:0% +oversee it because it Bears many the +same types of risks um I do think that + + align:start position:0% +same types of risks um I do think that + + + align:start position:0% +same types of risks um I do think that +Visa has slightly stricter um + + align:start position:0% +Visa has slightly stricter um + + + align:start position:0% +Visa has slightly stricter um +restrictions on some of this stuff as + + align:start position:0% +restrictions on some of this stuff as + + + align:start position:0% +restrictions on some of this stuff as +we'll talk about in a second but for all + + align:start position:0% +we'll talk about in a second but for all + + + align:start position:0% +we'll talk about in a second but for all +intens of purposes PayPal looks very + + align:start position:0% +intens of purposes PayPal looks very + + + align:start position:0% +intens of purposes PayPal looks very +similar is there any sort of idea of + + align:start position:0% +similar is there any sort of idea of + + + align:start position:0% +similar is there any sort of idea of +having like a group where you you know + + align:start position:0% +having like a group where you you know + + + align:start position:0% +having like a group where you you know +make some sort of account and then + + align:start position:0% +make some sort of account and then + + + align:start position:0% +make some sort of account and then +intentionally go to a bunch of spammers + + align:start position:0% +intentionally go to a bunch of spammers + + + align:start position:0% +intentionally go to a bunch of spammers +buy a bunch of things and then ask for a + + align:start position:0% +buy a bunch of things and then ask for a + + + align:start position:0% +buy a bunch of things and then ask for a +bunch of chargebacks whether or not they + + align:start position:0% +bunch of chargebacks whether or not they + + + align:start position:0% +bunch of chargebacks whether or not they +send it to you in order to like incur + + align:start position:0% +send it to you in order to like incur + + + align:start position:0% +send it to you in order to like incur +these fines or like report them for + + align:start position:0% +these fines or like report them for + + + align:start position:0% +these fines or like report them for +misclassifying bu things in order to + + align:start position:0% +misclassifying bu things in order to + + + align:start position:0% +misclassifying bu things in order to +like just make them pay these fines + + align:start position:0% +like just make them pay these fines + + + align:start position:0% +like just make them pay these fines +that's interesting yeah yeah it's like + + align:start position:0% +that's interesting yeah yeah it's like + + + align:start position:0% +that's interesting yeah yeah it's like +yeah exactly yeah it's like Vigilantes + + align:start position:0% +yeah exactly yeah it's like Vigilantes + + + align:start position:0% +yeah exactly yeah it's like Vigilantes +yeah exactly that's interesting I don't + + align:start position:0% +yeah exactly that's interesting I don't + + + align:start position:0% +yeah exactly that's interesting I don't +know if I've heard anything about that I + + align:start position:0% +know if I've heard anything about that I + + + align:start position:0% +know if I've heard anything about that I +do know that um the spammers do try to + + align:start position:0% +do know that um the spammers do try to + + + align:start position:0% +do know that um the spammers do try to +detect people who are trolling them so + + align:start position:0% +detect people who are trolling them so + + + align:start position:0% +detect people who are trolling them so +for example like one thing they talked + + align:start position:0% +for example like one thing they talked + + + align:start position:0% +for example like one thing they talked +about in the paper a little bit is that + + align:start position:0% +about in the paper a little bit is that + + + align:start position:0% +about in the paper a little bit is that +spammer so so what how how did the + + align:start position:0% +spammer so so what how how did the + + + align:start position:0% +spammer so so what how how did the +authors of the paper determine all this + + align:start position:0% +authors of the paper determine all this + + + align:start position:0% +authors of the paper determine all this +right so they actually got a bunch of + + align:start position:0% +right so they actually got a bunch of + + + align:start position:0% +right so they actually got a bunch of +spam messages they clicked on a bunch of + + align:start position:0% +spam messages they clicked on a bunch of + + + align:start position:0% +spam messages they clicked on a bunch of +stuff they got a special Visa card that + + align:start position:0% +stuff they got a special Visa card that + + + align:start position:0% +stuff they got a special Visa card that +they use to purchase this stuff and then + + align:start position:0% +they use to purchase this stuff and then + + + align:start position:0% +they use to purchase this stuff and then +so on and so forth so spammers obviously + + align:start position:0% +so on and so forth so spammers obviously + + + align:start position:0% +so on and so forth so spammers obviously +don't like this right and so uh in the + + align:start position:0% +don't like this right and so uh in the + + + align:start position:0% +don't like this right and so uh in the +paper they called this test buys + + align:start position:0% +paper they called this test buys + + + align:start position:0% +paper they called this test buys +spammers want to prevent these test buys + + align:start position:0% +spammers want to prevent these test buys + + + align:start position:0% +spammers want to prevent these test buys +from researchers who are trying to + + align:start position:0% +from researchers who are trying to + + + align:start position:0% +from researchers who are trying to +figure out what's going on so one thing + + align:start position:0% +figure out what's going on so one thing + + + align:start position:0% +figure out what's going on so one thing +that some spammers did um do I should + + align:start position:0% +that some spammers did um do I should + + + align:start position:0% +that some spammers did um do I should +say is they actually require proof of + + align:start position:0% +say is they actually require proof of + + + align:start position:0% +say is they actually require proof of +your identity before you can buy + + align:start position:0% +your identity before you can buy + + + align:start position:0% +your identity before you can buy +something so they might ask you to like + + align:start position:0% +something so they might ask you to like + + + align:start position:0% +something so they might ask you to like +send a picture of your photo ID or + + align:start position:0% +send a picture of your photo ID or + + + align:start position:0% +send a picture of your photo ID or +something like that um and in particular + + align:start position:0% +something like that um and in particular + + + align:start position:0% +something like that um and in particular +after uh people some people started + + align:start position:0% +after uh people some people started + + + align:start position:0% +after uh people some people started +doing this after Visa tightened up some + + align:start position:0% +doing this after Visa tightened up some + + + align:start position:0% +doing this after Visa tightened up some +of their uh sort of rules about spam now + + align:start position:0% +of their uh sort of rules about spam now + + + align:start position:0% +of their uh sort of rules about spam now +the problem with this is that + + align:start position:0% +the problem with this is that + + + align:start position:0% +the problem with this is that +uh most people who would click on spam + + align:start position:0% +uh most people who would click on spam + + + align:start position:0% +uh most people who would click on spam +apparently are still reluctant to send + + align:start position:0% +apparently are still reluctant to send + + + align:start position:0% +apparently are still reluctant to send +their photo ID to just some random + + align:start position:0% +their photo ID to just some random + + + align:start position:0% +their photo ID to just some random +person and so there's a bunch of uh I've + + align:start position:0% +person and so there's a bunch of uh I've + + + align:start position:0% +person and so there's a bunch of uh I've +linked one of these articles in lecture + + align:start position:0% +linked one of these articles in lecture + + + align:start position:0% +linked one of these articles in lecture +notes there's a bunch of hilarious + + align:start position:0% +notes there's a bunch of hilarious + + + align:start position:0% +notes there's a bunch of hilarious +commentary from a spammer bulletin board + + align:start position:0% +commentary from a spammer bulletin board + + + align:start position:0% +commentary from a spammer bulletin board +where they say oh no Vis is cracking + + align:start position:0% +where they say oh no Vis is cracking + + + align:start position:0% +where they say oh no Vis is cracking +down in us we tried to ask for people's + + align:start position:0% +down in us we tried to ask for people's + + + align:start position:0% +down in us we tried to ask for people's +photo IDs but they don't want to send it + + align:start position:0% +photo IDs but they don't want to send it + + + align:start position:0% +photo IDs but they don't want to send it +to us for some reason you know and it's + + align:start position:0% +to us for some reason you know and it's + + + align:start position:0% +to us for some reason you know and it's +so weird that people wouldn't want to do + + align:start position:0% +so weird that people wouldn't want to do + + + align:start position:0% +so weird that people wouldn't want to do +that but they will give them their their + + align:start position:0% +that but they will give them their their + + + align:start position:0% +that but they will give them their their +credit card number but anyway so long + + align:start position:0% +credit card number but anyway so long + + + align:start position:0% +credit card number but anyway so long +story short spammers are highly + + align:start position:0% +story short spammers are highly + + + align:start position:0% +story short spammers are highly +incentivized to try to test to detect + + align:start position:0% +incentivized to try to test to detect + + + align:start position:0% +incentivized to try to test to detect +that kind of + + align:start position:0% +that kind of + + + align:start position:0% +that kind of +stuff um so for charge marks if you + + align:start position:0% +stuff um so for charge marks if you + + + align:start position:0% +stuff um so for charge marks if you +don't necessarily want your bank to know + + align:start position:0% +don't necessarily want your bank to know + + + align:start position:0% +don't necessarily want your bank to know +that you're buying these Salu should the + + align:start position:0% +that you're buying these Salu should the + + + align:start position:0% +that you're buying these Salu should the +items do a lot of users actually do + + align:start position:0% +items do a lot of users actually do + + + align:start position:0% +items do a lot of users actually do +charge backs if they don't get the item + + align:start position:0% +charge backs if they don't get the item + + + align:start position:0% +charge backs if they don't get the item +or are they like too embarrassed to to + + align:start position:0% +or are they like too embarrassed to to + + + align:start position:0% +or are they like too embarrassed to to +report they didn't yeah it's a good + + align:start position:0% +report they didn't yeah it's a good + + + align:start position:0% +report they didn't yeah it's a good +question so I don't know what fraction + + align:start position:0% +question so I don't know what fraction + + + align:start position:0% +question so I don't know what fraction +of people who are in the set of people + + align:start position:0% +of people who are in the set of people + + + align:start position:0% +of people who are in the set of people +who bought herbal Flintstone vitamins + + align:start position:0% +who bought herbal Flintstone vitamins + + + align:start position:0% +who bought herbal Flintstone vitamins +were disappointed by herbal Flintstone + + align:start position:0% +were disappointed by herbal Flintstone + + + align:start position:0% +were disappointed by herbal Flintstone +vitamins and then yeah told their bank + + align:start position:0% +vitamins and then yeah told their bank + + + align:start position:0% +vitamins and then yeah told their bank +that but I mean what's interesting + + align:start position:0% +that but I mean what's interesting + + + align:start position:0% +that but I mean what's interesting +though is that the bank has to know in + + align:start position:0% +though is that the bank has to know in + + + align:start position:0% +though is that the bank has to know in +the first place that they're going to + + align:start position:0% +the first place that they're going to + + + align:start position:0% +the first place that they're going to +this place right because the thing went + + align:start position:0% +this place right because the thing went + + + align:start position:0% +this place right because the thing went +through right so avoiding the charge + + align:start position:0% +through right so avoiding the charge + + + align:start position:0% +through right so avoiding the charge +back I don't think you're going to but + + align:start position:0% +back I don't think you're going to but + + + align:start position:0% +back I don't think you're going to but +by doing the charge back let me see I + + align:start position:0% +by doing the charge back let me see I + + + align:start position:0% +by doing the charge back let me see I +don't think you reveal any extra + + align:start position:0% +don't think you reveal any extra + + + align:start position:0% +don't think you reveal any extra +information to the bank that they + + align:start position:0% +information to the bank that they + + + align:start position:0% +information to the bank that they +wouldn't already know CU they they they + + align:start position:0% +wouldn't already know CU they they they + + + align:start position:0% +wouldn't already know CU they they they +had to clear the transaction first for + + align:start position:0% +had to clear the transaction first for + + + align:start position:0% +had to clear the transaction first for +you to actually get it and be + + align:start position:0% +you to actually get it and be + + + align:start position:0% +you to actually get it and be +disappointed um so like roughly how many + + align:start position:0% +disappointed um so like roughly how many + + + align:start position:0% +disappointed um so like roughly how many +chargebacks is too much yeah so some of + + align:start position:0% +chargebacks is too much yeah so some of + + + align:start position:0% +chargebacks is too much yeah so some of +the figures I've heard here or greater + + align:start position:0% +the figures I've heard here or greater + + + align:start position:0% +the figures I've heard here or greater +than + + align:start position:0% +than + + + align:start position:0% +than +1% so so in other words if you're a + + align:start position:0% +1% so so in other words if you're a + + + align:start position:0% +1% so so in other words if you're a +spammer and you have more than 1% of + + align:start position:0% +spammer and you have more than 1% of + + + align:start position:0% +spammer and you have more than 1% of +your transactions causing these problems + + align:start position:0% +your transactions causing these problems + + + align:start position:0% +your transactions causing these problems +you get in + + align:start position:0% +you get in + + + align:start position:0% +you get in +trouble and I wouldn't be surprised if + + align:start position:0% +trouble and I wouldn't be surprised if + + + align:start position:0% +trouble and I wouldn't be surprised if +it was a little bit lower than that but + + align:start position:0% +it was a little bit lower than that but + + + align:start position:0% +it was a little bit lower than that but +1% is the number that I've + + align:start position:0% + + + + align:start position:0% + +heard all right so so yeah so so to me + + align:start position:0% +heard all right so so yeah so so to me + + + align:start position:0% +heard all right so so yeah so so to me +like I said this was one of the most uh + + align:start position:0% +like I said this was one of the most uh + + + align:start position:0% +like I said this was one of the most uh +interesting parts of the paper because I + + align:start position:0% +interesting parts of the paper because I + + + align:start position:0% +interesting parts of the paper because I +would have thought that a lot of + + align:start position:0% +would have thought that a lot of + + + align:start position:0% +would have thought that a lot of +spamming just involved just straight up + + align:start position:0% +spamming just involved just straight up + + + align:start position:0% +spamming just involved just straight up +fraud that people clicked on links they + + align:start position:0% +fraud that people clicked on links they + + + align:start position:0% +fraud that people clicked on links they +sent money they never got anything as it + + align:start position:0% +sent money they never got anything as it + + + align:start position:0% +sent money they never got anything as it +turns out because because these spammers + + align:start position:0% +turns out because because these spammers + + + align:start position:0% +turns out because because these spammers +have to go through this um this network + + align:start position:0% +have to go through this um this network + + + align:start position:0% +have to go through this um this network +which has all of these sort of + + align:start position:0% +which has all of these sort of + + + align:start position:0% +which has all of these sort of +mechanisms to prevent um sort of fraud + + align:start position:0% +mechanisms to prevent um sort of fraud + + + align:start position:0% +mechanisms to prevent um sort of fraud +they end up do having to actually uh + + align:start position:0% +they end up do having to actually uh + + + align:start position:0% +they end up do having to actually uh +ship things over to + + align:start position:0% +ship things over to + + + align:start position:0% +ship things over to +users so that's kind of kind of neat um + + align:start position:0% +users so that's kind of kind of neat um + + + align:start position:0% +users so that's kind of kind of neat um +and so the other another reason why + + align:start position:0% +and so the other another reason why + + + align:start position:0% +and so the other another reason why +spammers want to do these things + + align:start position:0% +spammers want to do these things + + + align:start position:0% +spammers want to do these things +properly classified transactions and + + align:start position:0% +properly classified transactions and + + + align:start position:0% +properly classified transactions and +actually send things to users is that + + align:start position:0% +actually send things to users is that + + + align:start position:0% +actually send things to users is that +um only a few + + align:start position:0% + + + + align:start position:0% + +banks are actually + + align:start position:0% +banks are actually + + + align:start position:0% +banks are actually +willing to interact with + + align:start position:0% + + + + align:start position:0% + +spammers and so what this means is + + align:start position:0% + + + + align:start position:0% + +that you know if the spammer is getting + + align:start position:0% +that you know if the spammer is getting + + + align:start position:0% +that you know if the spammer is getting +a lot of chargebacks or getting in + + align:start position:0% +a lot of chargebacks or getting in + + + align:start position:0% +a lot of chargebacks or getting in +trouble with the bank or the credit card + + align:start position:0% +trouble with the bank or the credit card + + + align:start position:0% +trouble with the bank or the credit card +company or whatever and some Bank + + align:start position:0% +company or whatever and some Bank + + + align:start position:0% +company or whatever and some Bank +decides I can't do business with you + + align:start position:0% +decides I can't do business with you + + + align:start position:0% +decides I can't do business with you +anymore there's not a really large set + + align:start position:0% +anymore there's not a really large set + + + align:start position:0% +anymore there's not a really large set +of other banks that the spammer could go + + align:start position:0% +of other banks that the spammer could go + + + align:start position:0% +of other banks that the spammer could go +to to continue um their chainer so uh + + align:start position:0% +to to continue um their chainer so uh + + + align:start position:0% +to to continue um their chainer so uh +you know one study of this stuff found + + align:start position:0% +you know one study of this stuff found + + + align:start position:0% +you know one study of this stuff found +that there are basically only + + align:start position:0% +that there are basically only + + + align:start position:0% +that there are basically only +30 uh acquiring + + align:start position:0% +30 uh acquiring + + + align:start position:0% +30 uh acquiring +banks that spammers were seen to use + + align:start position:0% +banks that spammers were seen to use + + + align:start position:0% +banks that spammers were seen to use +over some two-year period and that's + + align:start position:0% +over some two-year period and that's + + + align:start position:0% +over some two-year period and that's +actually not very high right so there is + + align:start position:0% +actually not very high right so there is + + + align:start position:0% +actually not very high right so there is +this other incentive to not um to not + + align:start position:0% +this other incentive to not um to not + + + align:start position:0% +this other incentive to not um to not +sort of be too Goofy with the financial + + align:start position:0% +sort of be too Goofy with the financial + + + align:start position:0% +sort of be too Goofy with the financial +system because you don't really have too + + align:start position:0% +system because you don't really have too + + + align:start position:0% +system because you don't really have too +many other places to go if you break + + align:start position:0% +many other places to go if you break + + + align:start position:0% +many other places to go if you break +those relationships um so it seems like + + align:start position:0% +those relationships um so it seems like + + + align:start position:0% +those relationships um so it seems like +maybe this is a good choke point + + align:start position:0% +maybe this is a good choke point + + + align:start position:0% +maybe this is a good choke point +to try to cut down on spam so we've + + align:start position:0% +to try to cut down on spam so we've + + + align:start position:0% +to try to cut down on spam so we've +already discussed how things like + + align:start position:0% +already discussed how things like + + + align:start position:0% +already discussed how things like +botnets give the attacker a lot of IP + + align:start position:0% +botnets give the attacker a lot of IP + + + align:start position:0% +botnets give the attacker a lot of IP +addresses there's a lot of uh you know + + align:start position:0% +addresses there's a lot of uh you know + + + align:start position:0% +addresses there's a lot of uh you know +different types of hosts who are willing + + align:start position:0% +different types of hosts who are willing + + + align:start position:0% +different types of hosts who are willing +to run we servers so on and so forth but + + align:start position:0% +to run we servers so on and so forth but + + + align:start position:0% +to run we servers so on and so forth but +this number actually seems small so + + align:start position:0% +this number actually seems small so + + + align:start position:0% +this number actually seems small so +maybe we can actually attack spamming + + align:start position:0% +maybe we can actually attack spamming + + + align:start position:0% +maybe we can actually attack spamming +here um but as I alluded to earlier it's + + align:start position:0% +here um but as I alluded to earlier it's + + + align:start position:0% +here um but as I alluded to earlier it's +a little bit tricky to do this because + + align:start position:0% +a little bit tricky to do this because + + + align:start position:0% +a little bit tricky to do this because +of things like differing IP laws because + + align:start position:0% +of things like differing IP laws because + + + align:start position:0% +of things like differing IP laws because +of things like um the fact that it can + + align:start position:0% +of things like um the fact that it can + + + align:start position:0% +of things like um the fact that it can +be um sort of tricky to to actually say + + align:start position:0% +be um sort of tricky to to actually say + + + align:start position:0% +be um sort of tricky to to actually say +say that spammers are doing something + + align:start position:0% +say that spammers are doing something + + + align:start position:0% +say that spammers are doing something +illegal right so you know if you are + + align:start position:0% +illegal right so you know if you are + + + align:start position:0% +illegal right so you know if you are +using spam messages to sell someone just + + align:start position:0% +using spam messages to sell someone just + + + align:start position:0% +using spam messages to sell someone just +making this up let's say sugar right + + align:start position:0% +making this up let's say sugar right + + + align:start position:0% +making this up let's say sugar right +Sugar's delicious it's not illegal to + + align:start position:0% +Sugar's delicious it's not illegal to + + + align:start position:0% +Sugar's delicious it's not illegal to +sell sugar even at Cut Rate prices right + + align:start position:0% +sell sugar even at Cut Rate prices right + + + align:start position:0% +sell sugar even at Cut Rate prices right +so even though the way that you may have + + align:start position:0% +so even though the way that you may have + + + align:start position:0% +so even though the way that you may have +drawn the user to that purchase was sort + + align:start position:0% +drawn the user to that purchase was sort + + + align:start position:0% +drawn the user to that purchase was sort +of duplicitous or kind of gross it is + + align:start position:0% +of duplicitous or kind of gross it is + + + align:start position:0% +of duplicitous or kind of gross it is +not in and of itself illegal to sell + + align:start position:0% +not in and of itself illegal to sell + + + align:start position:0% +not in and of itself illegal to sell +someone sugar right and so as it turns + + align:start position:0% +someone sugar right and so as it turns + + + align:start position:0% +someone sugar right and so as it turns +out a lot of spam sort of falls into um + + align:start position:0% +out a lot of spam sort of falls into um + + + align:start position:0% +out a lot of spam sort of falls into um +this gray area where the things that the + + align:start position:0% +this gray area where the things that the + + + align:start position:0% +this gray area where the things that the +spammers are doing are tasteful but + + align:start position:0% +spammers are doing are tasteful but + + + align:start position:0% +spammers are doing are tasteful but +maybe not necessarily as illegal as you + + align:start position:0% +maybe not necessarily as illegal as you + + + align:start position:0% +maybe not necessarily as illegal as you +think now for stuff like uh you know + + align:start position:0% +think now for stuff like uh you know + + + align:start position:0% +think now for stuff like uh you know +pirated software there it's much more + + align:start position:0% +pirated software there it's much more + + + align:start position:0% +pirated software there it's much more +clear-cut but suffice to say it's not + + align:start position:0% +clear-cut but suffice to say it's not + + + align:start position:0% +clear-cut but suffice to say it's not +always the case that you just point to + + align:start position:0% +always the case that you just point to + + + align:start position:0% +always the case that you just point to +one of these Banks and say hey your + + align:start position:0% +one of these Banks and say hey your + + + align:start position:0% +one of these Banks and say hey your +customers are criminals because that's + + align:start position:0% +customers are criminals because that's + + + align:start position:0% +customers are criminals because that's +not always true particularly if uh + + align:start position:0% +not always true particularly if uh + + + align:start position:0% +not always true particularly if uh +there's not a very strong um sort of + + align:start position:0% +there's not a very strong um sort of + + + align:start position:0% +there's not a very strong um sort of +paper trail that uh sort of attaches the + + align:start position:0% +paper trail that uh sort of attaches the + + + align:start position:0% +paper trail that uh sort of attaches the +financial transaction to some spam URL + + align:start position:0% +financial transaction to some spam URL + + + align:start position:0% +financial transaction to some spam URL +that was sort of the origin of the + + align:start position:0% +that was sort of the origin of the + + + align:start position:0% +that was sort of the origin of the +transaction right it's often very + + align:start position:0% +transaction right it's often very + + + align:start position:0% +transaction right it's often very +difficult to prove those types of links + + align:start position:0% +difficult to prove those types of links + + + align:start position:0% +difficult to prove those types of links +uh okay so uh since this paper was + + align:start position:0% +uh okay so uh since this paper was + + + align:start position:0% +uh okay so uh since this paper was +published uh the credit card uh networks + + align:start position:0% +published uh the credit card uh networks + + + align:start position:0% +published uh the credit card uh networks +have taken some action so this paper + + align:start position:0% +have taken some action so this paper + + + align:start position:0% +have taken some action so this paper +actually made a pretty big splash when + + align:start position:0% +actually made a pretty big splash when + + + align:start position:0% +actually made a pretty big splash when +it came out and so uh you know the the + + align:start position:0% +it came out and so uh you know the the + + + align:start position:0% +it came out and so uh you know the the +association networks like visa and + + align:start position:0% +association networks like visa and + + + align:start position:0% +association networks like visa and +MasterCard and all of them were sort of + + align:start position:0% +MasterCard and all of them were sort of + + + align:start position:0% +MasterCard and all of them were sort of +wondering what can we do to sort of cut + + align:start position:0% +wondering what can we do to sort of cut + + + align:start position:0% +wondering what can we do to sort of cut +down on some of this uh spam so + + align:start position:0% +down on some of this uh spam so + + + align:start position:0% +down on some of this uh spam so +interestingly after the paper came out + + align:start position:0% +interestingly after the paper came out + + + align:start position:0% +interestingly after the paper came out +some pharmaceutical companies and + + align:start position:0% +some pharmaceutical companies and + + + align:start position:0% +some pharmaceutical companies and +software vendors actually lodged + + align:start position:0% +software vendors actually lodged + + + align:start position:0% +software vendors actually lodged +complaints with Visa right so if you + + align:start position:0% +complaints with Visa right so if you + + + align:start position:0% +complaints with Visa right so if you +remember from the paper Visa was the + + align:start position:0% +remember from the paper Visa was the + + + align:start position:0% +remember from the paper Visa was the +associ Network that the researchers use + + align:start position:0% +associ Network that the researchers use + + + align:start position:0% +associ Network that the researchers use +to make these these test buys these + + align:start position:0% +to make these these test buys these + + + align:start position:0% +to make these these test buys these +dummy Buys so um you know it's a little + + align:start position:0% +dummy Buys so um you know it's a little + + + align:start position:0% +dummy Buys so um you know it's a little +bit unfortunate but that then sort of + + align:start position:0% +bit unfortunate but that then sort of + + + align:start position:0% +bit unfortunate but that then sort of +showed some of these companies that hey + + align:start position:0% +showed some of these companies that hey + + + align:start position:0% +showed some of these companies that hey +Visa can be used as sort of the + + align:start position:0% +Visa can be used as sort of the + + + align:start position:0% +Visa can be used as sort of the +association Network to to sort of fund + + align:start position:0% +association Network to to sort of fund + + + align:start position:0% +association Network to to sort of fund +some of the spam or or to Transit some + + align:start position:0% +some of the spam or or to Transit some + + + align:start position:0% +some of the spam or or to Transit some +of the spam traffic um so some people + + align:start position:0% +of the spam traffic um so some people + + + align:start position:0% +of the spam traffic um so some people +complained about that and so uh Visa + + align:start position:0% +complained about that and so uh Visa + + + align:start position:0% +complained about that and so uh Visa +made some policy + + align:start position:0% +made some policy + + + align:start position:0% +made some policy +changes uh in response to some of the + + align:start position:0% +changes uh in response to some of the + + + align:start position:0% +changes uh in response to some of the +issues that were brought up in the paper + + align:start position:0% +issues that were brought up in the paper + + + align:start position:0% +issues that were brought up in the paper +paper and some of the complaints uh that + + align:start position:0% +paper and some of the complaints uh that + + + align:start position:0% +paper and some of the complaints uh that +they got as a result so now for example + + align:start position:0% +they got as a result so now for example + + + align:start position:0% +they got as a result so now for example +um all pharmaceutical + + align:start position:0% + + + + align:start position:0% + +sales are now uh + + align:start position:0% +sales are now uh + + + align:start position:0% +sales are now uh +labeled by Visa as high + + align:start position:0% + + + + align:start position:0% + +risk so what this means is + + align:start position:0% +risk so what this means is + + + align:start position:0% +risk so what this means is +that if a bank acts as uh an acquirer + + align:start position:0% +that if a bank acts as uh an acquirer + + + align:start position:0% +that if a bank acts as uh an acquirer +for these high risk uh uh transactions + + align:start position:0% +for these high risk uh uh transactions + + + align:start position:0% +for these high risk uh uh transactions +then Visa will have some more stringent + + align:start position:0% +then Visa will have some more stringent + + + align:start position:0% +then Visa will have some more stringent +regulations that they will put on that + + align:start position:0% +regulations that they will put on that + + + align:start position:0% +regulations that they will put on that +Merchant side bank so for example they + + align:start position:0% +Merchant side bank so for example they + + + align:start position:0% +Merchant side bank so for example they +will require that bank to engage in a + + align:start position:0% +will require that bank to engage in a + + + align:start position:0% +will require that bank to engage in a +risk management program and you know + + align:start position:0% +risk management program and you know + + + align:start position:0% +risk management program and you know +they may be audited it more frequently + + align:start position:0% +they may be audited it more frequently + + + align:start position:0% +they may be audited it more frequently +and so on and so forth so Visa made that + + align:start position:0% +and so on and so forth so Visa made that + + + align:start position:0% +and so on and so forth so Visa made that +change + + align:start position:0% +change + + + align:start position:0% +change +um and Visa also uh sort of changed its + + align:start position:0% +um and Visa also uh sort of changed its + + + align:start position:0% +um and Visa also uh sort of changed its +uh operating + + align:start position:0% +uh operating + + + align:start position:0% +uh operating +guidelines so it's operating + + align:start position:0% + + + + align:start position:0% + +guidelines now they + + align:start position:0% +guidelines now they + + + align:start position:0% +guidelines now they +explicitly enumerate and forbid legal + + align:start position:0% +explicitly enumerate and forbid legal + + + align:start position:0% +explicitly enumerate and forbid legal +sales of uh drugs and trademark + + align:start position:0% +sales of uh drugs and trademark + + + align:start position:0% +sales of uh drugs and trademark +enforcing + + align:start position:0% + + + + align:start position:0% + +Goods so the reason why they did this is + + align:start position:0% +Goods so the reason why they did this is + + + align:start position:0% +Goods so the reason why they did this is +that by tightening up this language uh + + align:start position:0% +that by tightening up this language uh + + + align:start position:0% +that by tightening up this language uh +it is now easier for them to issue more + + align:start position:0% +it is now easier for them to issue more + + + align:start position:0% +it is now easier for them to issue more +aggressive fines against uh Banks and + + align:start position:0% +aggressive fines against uh Banks and + + + align:start position:0% +aggressive fines against uh Banks and +Merchants that they feel are uh doing + + align:start position:0% +Merchants that they feel are uh doing + + + align:start position:0% +Merchants that they feel are uh doing +things like like selling illegal + + align:start position:0% +things like like selling illegal + + + align:start position:0% +things like like selling illegal +pharmaceu or selling uh uh knockoff + + align:start position:0% +pharmaceu or selling uh uh knockoff + + + align:start position:0% +pharmaceu or selling uh uh knockoff +versions of Watches or things like that + + align:start position:0% +versions of Watches or things like that + + + align:start position:0% +versions of Watches or things like that +um so once again there there's still a + + align:start position:0% +um so once again there there's still a + + + align:start position:0% +um so once again there there's still a +lot of this spam that's in that gray + + align:start position:0% +lot of this spam that's in that gray + + + align:start position:0% +lot of this spam that's in that gray +area where it's not necessarily legal + + align:start position:0% +area where it's not necessarily legal + + + align:start position:0% +area where it's not necessarily legal +it's just that the customers required + + align:start position:0% +it's just that the customers required + + + align:start position:0% +it's just that the customers required +through spamming techniques but this is + + align:start position:0% +through spamming techniques but this is + + + align:start position:0% +through spamming techniques but this is +very useful because now Visa can drop + + align:start position:0% +very useful because now Visa can drop + + + align:start position:0% +very useful because now Visa can drop +some much bigger uh much bigger hammers + + align:start position:0% +some much bigger uh much bigger hammers + + + align:start position:0% +some much bigger uh much bigger hammers +on + + align:start position:0% +on + + + align:start position:0% +on +folks and as I mentioned before some of + + align:start position:0% +folks and as I mentioned before some of + + + align:start position:0% +folks and as I mentioned before some of +the spammers tried to react to this by + + align:start position:0% +the spammers tried to react to this by + + + align:start position:0% +the spammers tried to react to this by +saying well let's just prevent these + + align:start position:0% +saying well let's just prevent these + + + align:start position:0% +saying well let's just prevent these +test buys right because not only do + + align:start position:0% +test buys right because not only do + + + align:start position:0% +test buys right because not only do +security research do these test buys but + + align:start position:0% +security research do these test buys but + + + align:start position:0% +security research do these test buys but +the Association networks can do these + + align:start position:0% +the Association networks can do these + + + align:start position:0% +the Association networks can do these +test buys too so they did some things + + align:start position:0% +test buys too so they did some things + + + align:start position:0% +test buys too so they did some things +like the photo ID type stuff and that + + align:start position:0% +like the photo ID type stuff and that + + + align:start position:0% +like the photo ID type stuff and that +tended not to work out super well um and + + align:start position:0% +tended not to work out super well um and + + + align:start position:0% +tended not to work out super well um and +so at least a few years after these + + align:start position:0% +so at least a few years after these + + + align:start position:0% +so at least a few years after these +changes were made this did have an + + align:start position:0% +changes were made this did have an + + + align:start position:0% +changes were made this did have an +impact I'm not sure uh sort of what the + + align:start position:0% +impact I'm not sure uh sort of what the + + + align:start position:0% +impact I'm not sure uh sort of what the +latest state of the-art is with respect + + align:start position:0% +latest state of the-art is with respect + + + align:start position:0% +latest state of the-art is with respect +to sort of trolling these Visa policy + + align:start position:0% +to sort of trolling these Visa policy + + + align:start position:0% +to sort of trolling these Visa policy +changes but it was kind of cool to see + + align:start position:0% +changes but it was kind of cool to see + + + align:start position:0% +changes but it was kind of cool to see +this paper have uh this impact in real + + align:start position:0% +this paper have uh this impact in real + + + align:start position:0% +this paper have uh this impact in real +life so one interesting thing they + + align:start position:0% +life so one interesting thing they + + + align:start position:0% +life so one interesting thing they +mentioned in the paper is they talked + + align:start position:0% +mentioned in the paper is they talked + + + align:start position:0% +mentioned in the paper is they talked +about um sort of the ethical aspects of + + align:start position:0% +about um sort of the ethical aspects of + + + align:start position:0% +about um sort of the ethical aspects of +doing security research and particular + + align:start position:0% +doing security research and particular + + + align:start position:0% +doing security research and particular +doing this research about the spam chain + + align:start position:0% +doing this research about the spam chain + + + align:start position:0% +doing this research about the spam chain +so you know to actually understand how + + align:start position:0% +so you know to actually understand how + + + align:start position:0% +so you know to actually understand how +some of this banking stuff worked these + + align:start position:0% +some of this banking stuff worked these + + + align:start position:0% +some of this banking stuff worked these +researchers actually had to make + + align:start position:0% +researchers actually had to make + + + align:start position:0% +researchers actually had to make +purchases they actually had to give + + align:start position:0% +purchases they actually had to give + + + align:start position:0% +purchases they actually had to give +money to people in exchange for these + + align:start position:0% +money to people in exchange for these + + + align:start position:0% +money to people in exchange for these +products and so in the paper they go + + align:start position:0% +products and so in the paper they go + + + align:start position:0% +products and so in the paper they go +through this uh kind of semih hilarious + + align:start position:0% +through this uh kind of semih hilarious + + + align:start position:0% +through this uh kind of semih hilarious +uh defensive section where they say we + + align:start position:0% +uh defensive section where they say we + + + align:start position:0% +uh defensive section where they say we +totally burned everything that we bought + + align:start position:0% +totally burned everything that we bought + + + align:start position:0% +totally burned everything that we bought +we didn't use it and you know we talked + + align:start position:0% +we didn't use it and you know we talked + + + align:start position:0% +we didn't use it and you know we talked +to the companies whose pirate software + + align:start position:0% +to the companies whose pirate software + + + align:start position:0% +to the companies whose pirate software +we were buying before we got it but + + align:start position:0% +we were buying before we got it but + + + align:start position:0% +we were buying before we got it but +these things are actually pretty + + align:start position:0% +these things are actually pretty + + + align:start position:0% +these things are actually pretty +important to go through particular if + + align:start position:0% +important to go through particular if + + + align:start position:0% +important to go through particular if +you're in a university setting because + + align:start position:0% +you're in a university setting because + + + align:start position:0% +you're in a university setting because +as you may know if you want to do + + align:start position:0% +as you may know if you want to do + + + align:start position:0% +as you may know if you want to do +anything that involves like particularly + + align:start position:0% +anything that involves like particularly + + + align:start position:0% +anything that involves like particularly +human research but anything that might + + align:start position:0% +human research but anything that might + + + align:start position:0% +human research but anything that might +have these ethical sort of aspects to it + + align:start position:0% +have these ethical sort of aspects to it + + + align:start position:0% +have these ethical sort of aspects to it +you have to get things cleared by + + align:start position:0% +you have to get things cleared by + + + align:start position:0% +you have to get things cleared by +lawyers sometimes like an IRB and things + + align:start position:0% +lawyers sometimes like an IRB and things + + + align:start position:0% +lawyers sometimes like an IRB and things +like that so it was actually pretty + + align:start position:0% +like that so it was actually pretty + + + align:start position:0% +like that so it was actually pretty +important for them to jump through these + + align:start position:0% +important for them to jump through these + + + align:start position:0% +important for them to jump through these +hoops because you know at the end of the + + align:start position:0% +hoops because you know at the end of the + + + align:start position:0% +hoops because you know at the end of the +day they had to you know at least be + + align:start position:0% +day they had to you know at least be + + + align:start position:0% +day they had to you know at least be +somewhat confident that they weren't + + align:start position:0% +somewhat confident that they weren't + + + align:start position:0% +somewhat confident that they weren't +supporting some you know deeply + + align:start position:0% +supporting some you know deeply + + + align:start position:0% +supporting some you know deeply +nefarious activity in some you know + + align:start position:0% +nefarious activity in some you know + + + align:start position:0% +nefarious activity in some you know +far-flung corner of the world so I + + align:start position:0% +far-flung corner of the world so I + + + align:start position:0% +far-flung corner of the world so I +thought that was another interesting + + align:start position:0% +thought that was another interesting + + + align:start position:0% +thought that was another interesting +part of the paper too um and you know + + align:start position:0% +part of the paper too um and you know + + + align:start position:0% +part of the paper too um and you know +other people have talked in this class + + align:start position:0% +other people have talked in this class + + + align:start position:0% +other people have talked in this class +about things like what the um ethics of + + align:start position:0% +about things like what the um ethics of + + + align:start position:0% +about things like what the um ethics of +releasing you know zero day exploits if + + align:start position:0% +releasing you know zero day exploits if + + + align:start position:0% +releasing you know zero day exploits if +you know they haven't been patched by + + align:start position:0% +you know they haven't been patched by + + + align:start position:0% +you know they haven't been patched by +someone so it's a really interesting + + align:start position:0% +someone so it's a really interesting + + + align:start position:0% +someone so it's a really interesting +aspect of doing security research is + + align:start position:0% +aspect of doing security research is + + + align:start position:0% +aspect of doing security research is +there any sort of oversight on like + + align:start position:0% +there any sort of oversight on like + + + align:start position:0% +there any sort of oversight on like +security ethics cuz from the paper they + + align:start position:0% +security ethics cuz from the paper they + + + align:start position:0% +security ethics cuz from the paper they +said the IRB wasn't interested so is + + align:start position:0% +said the IRB wasn't interested so is + + + align:start position:0% +said the IRB wasn't interested so is +there yeah so that was super interesting + + align:start position:0% +there yeah so that was super interesting + + + align:start position:0% +there yeah so that was super interesting +yeah so they said the IR the uh the IRB + + align:start position:0% +yeah so they said the IR the uh the IRB + + + align:start position:0% +yeah so they said the IR the uh the IRB +wasn't interested I think because there + + align:start position:0% +wasn't interested I think because there + + + align:start position:0% +wasn't interested I think because there +was no like obvious human subject um but + + align:start position:0% +was no like obvious human subject um but + + + align:start position:0% +was no like obvious human subject um but +I think that at most universities you + + align:start position:0% +I think that at most universities you + + + align:start position:0% +I think that at most universities you +couldn't just you couldn't just say oh + + align:start position:0% +couldn't just you couldn't just say oh + + + align:start position:0% +couldn't just you couldn't just say oh +there's no Direct human subject let me + + align:start position:0% +there's no Direct human subject let me + + + align:start position:0% +there's no Direct human subject let me +just go buy some stuff from just some + + align:start position:0% +just go buy some stuff from just some + + + align:start position:0% +just go buy some stuff from just some +some body at the end of a Spam link + + align:start position:0% +some body at the end of a Spam link + + + align:start position:0% +some body at the end of a Spam link +right and what they described in the + + align:start position:0% +right and what they described in the + + + align:start position:0% +right and what they described in the +paper that and actually the + + align:start position:0% +paper that and actually the + + + align:start position:0% +paper that and actually the +knowledgement sections they they think + + align:start position:0% +knowledgement sections they they think + + + align:start position:0% +knowledgement sections they they think +like this whole set of people like you + + align:start position:0% +like this whole set of people like you + + + align:start position:0% +like this whole set of people like you +know Sally at legal and you know so and + + align:start position:0% +know Sally at legal and you know so and + + + align:start position:0% +know Sally at legal and you know so and +so you know the philosopher for ethical + + align:start position:0% +so you know the philosopher for ethical + + + align:start position:0% +so you know the philosopher for ethical +Computing Association and stuff like + + align:start position:0% +Computing Association and stuff like + + + align:start position:0% +Computing Association and stuff like +that uh so I don't think there's + + align:start position:0% +that uh so I don't think there's + + + align:start position:0% +that uh so I don't think there's +actually like a uh how do you say like a + + align:start position:0% +actually like a uh how do you say like a + + + align:start position:0% +actually like a uh how do you say like a +like a an America wide let's say + + align:start position:0% +like a an America wide let's say + + + align:start position:0% +like a an America wide let's say +standard for doing this type of research + + align:start position:0% +standard for doing this type of research + + + align:start position:0% +standard for doing this type of research +I know that each University irbs sort of + + align:start position:0% +I know that each University irbs sort of + + + align:start position:0% +I know that each University irbs sort of +have slightly different policies on what + + align:start position:0% +have slightly different policies on what + + + align:start position:0% +have slightly different policies on what +they do and do not allow um but I don't + + align:start position:0% +they do and do not allow um but I don't + + + align:start position:0% +they do and do not allow um but I don't +think there's a there's a blanket + + align:start position:0% +think there's a there's a blanket + + + align:start position:0% +think there's a there's a blanket +policy out of the 350 million spams or + + align:start position:0% +policy out of the 350 million spams or + + + align:start position:0% +policy out of the 350 million spams or +whatever that they checked before in the + + align:start position:0% +whatever that they checked before in the + + + align:start position:0% +whatever that they checked before in the +28 that actually responded is there any + + align:start position:0% +28 that actually responded is there any + + + align:start position:0% +28 that actually responded is there any +chance that an appreciable number of + + align:start position:0% +chance that an appreciable number of + + + align:start position:0% +chance that an appreciable number of +those 28 spam responses are coming from + + align:start position:0% +those 28 spam responses are coming from + + + align:start position:0% +those 28 spam responses are coming from +researchers researching on spam + + align:start position:0% +researchers researching on spam + + + align:start position:0% +researchers researching on spam +responses no well it's true and this + + align:start position:0% +responses no well it's true and this + + + align:start position:0% +responses no well it's true and this +type of calculus is actually one reason + + align:start position:0% +type of calculus is actually one reason + + + align:start position:0% +type of calculus is actually one reason +why I think the authors went to such + + align:start position:0% +why I think the authors went to such + + + align:start position:0% +why I think the authors went to such +lengths to sort of defend themselves + + align:start position:0% +lengths to sort of defend themselves + + + align:start position:0% +lengths to sort of defend themselves +because if you think about it you know + + align:start position:0% +because if you think about it you know + + + align:start position:0% +because if you think about it you know +the reason why those statistics are so + + align:start position:0% +the reason why those statistics are so + + + align:start position:0% +the reason why those statistics are so +hilarious is that means like if you were + + align:start position:0% +hilarious is that means like if you were + + + align:start position:0% +hilarious is that means like if you were +to add five or remove five that's the + + align:start position:0% +to add five or remove five that's the + + + align:start position:0% +to add five or remove five that's the +difference between like a Spam being + + align:start position:0% +difference between like a Spam being + + + align:start position:0% +difference between like a Spam being +able to give their kids like a real gift + + align:start position:0% +able to give their kids like a real gift + + + align:start position:0% +able to give their kids like a real gift +versus like a piece of coal right + + align:start position:0% +versus like a piece of coal right + + + align:start position:0% +versus like a piece of coal right +because those numbers are so small uh + + align:start position:0% +because those numbers are so small uh + + + align:start position:0% +because those numbers are so small uh +and so I think that so with respect to + + align:start position:0% +and so I think that so with respect to + + + align:start position:0% +and so I think that so with respect to +those that particular stick I gave you I + + align:start position:0% +those that particular stick I gave you I + + + align:start position:0% +those that particular stick I gave you I +don't I don't really know you know how + + align:start position:0% +don't I don't really know you know how + + + align:start position:0% +don't I don't really know you know how +many of those were researchers um but I + + align:start position:0% +many of those were researchers um but I + + + align:start position:0% +many of those were researchers um but I +do think in general like I said the + + align:start position:0% +do think in general like I said the + + + align:start position:0% +do think in general like I said the +spammers they want to take your money + + align:start position:0% +spammers they want to take your money + + + align:start position:0% +spammers they want to take your money +and so if they could find some + + align:start position:0% +and so if they could find some + + + align:start position:0% +and so if they could find some +equilibrium whereby you know security + + align:start position:0% +equilibrium whereby you know security + + + align:start position:0% +equilibrium whereby you know security +research could do test buys but that had + + align:start position:0% +research could do test buys but that had + + + align:start position:0% +research could do test buys but that had +no impact on their overall sales B + + align:start position:0% +no impact on their overall sales B + + + align:start position:0% +no impact on their overall sales B +they'd be fine with that because they + + align:start position:0% +they'd be fine with that because they + + + align:start position:0% +they'd be fine with that because they +just want the money the tricky thing is + + align:start position:0% +just want the money the tricky thing is + + + align:start position:0% +just want the money the tricky thing is +that let's say that I'm just making this + + align:start position:0% +that let's say that I'm just making this + + + align:start position:0% +that let's say that I'm just making this +number up half of those 35 were test + + align:start position:0% +number up half of those 35 were test + + + align:start position:0% +number up half of those 35 were test +buys then that resulted in people + + align:start position:0% +buys then that resulted in people + + + align:start position:0% +buys then that resulted in people +putting pressure on the banks and then + + align:start position:0% +putting pressure on the banks and then + + + align:start position:0% +putting pressure on the banks and then +instead of 35 they'd be getting two that + + align:start position:0% +instead of 35 they'd be getting two that + + + align:start position:0% +instead of 35 they'd be getting two that +they don't want so that's why they're so + + align:start position:0% +they don't want so that's why they're so + + + align:start position:0% +they don't want so that's why they're so +motivated to stop that stuff how much is + + align:start position:0% +motivated to stop that stuff how much is + + + align:start position:0% +motivated to stop that stuff how much is +this is like blind emailing versus you + + align:start position:0% +this is like blind emailing versus you + + + align:start position:0% +this is like blind emailing versus you +any sort of filing so I'm sure they + + align:start position:0% +any sort of filing so I'm sure they + + + align:start position:0% +any sort of filing so I'm sure they +could run some models and get that 350 + + align:start position:0% +could run some models and get that 350 + + + align:start position:0% +could run some models and get that 350 +million now to like 1 million yeah so + + align:start position:0% +million now to like 1 million yeah so + + + align:start position:0% +million now to like 1 million yeah so +it's all about sort of the cost cost + + align:start position:0% +it's all about sort of the cost cost + + + align:start position:0% +it's all about sort of the cost cost +benefit analysis from the perspective of + + align:start position:0% +benefit analysis from the perspective of + + + align:start position:0% +benefit analysis from the perspective of +the spammer um so I think that you're + + align:start position:0% +the spammer um so I think that you're + + + align:start position:0% +the spammer um so I think that you're +right and there are actually uh there's + + align:start position:0% +right and there are actually uh there's + + + align:start position:0% +right and there are actually uh there's +a Marketplace for how to say it like + + align:start position:0% +a Marketplace for how to say it like + + + align:start position:0% +a Marketplace for how to say it like +more targeted stuff in particular that's + + align:start position:0% +more targeted stuff in particular that's + + + align:start position:0% +more targeted stuff in particular that's +where some of those compromised email + + align:start position:0% +where some of those compromised email + + + align:start position:0% +where some of those compromised email +accounts can become very useful right + + align:start position:0% +accounts can become very useful right + + + align:start position:0% +accounts can become very useful right +and so um but I think what you see is + + align:start position:0% +and so um but I think what you see is + + + align:start position:0% +and so um but I think what you see is +that people tend to um go for the more + + align:start position:0% +that people tend to um go for the more + + + align:start position:0% +that people tend to um go for the more +focused stuff uh like the more focused + + align:start position:0% +focused stuff uh like the more focused + + + align:start position:0% +focused stuff uh like the more focused +spam emails for what they view as like + + align:start position:0% +spam emails for what they view as like + + + align:start position:0% +spam emails for what they view as like +higher reward targets so for example + + align:start position:0% +higher reward targets so for example + + + align:start position:0% +higher reward targets so for example +like um political groups or like you + + align:start position:0% +like um political groups or like you + + + align:start position:0% +like um political groups or like you +know people associated with the doy Lama + + align:start position:0% +know people associated with the doy Lama + + + align:start position:0% +know people associated with the doy Lama +for instance like there it's uh that the + + align:start position:0% +for instance like there it's uh that the + + + align:start position:0% +for instance like there it's uh that the +perceived value of being able to get + + align:start position:0% +perceived value of being able to get + + + align:start position:0% +perceived value of being able to get +into that system is so high that people + + align:start position:0% +into that system is so high that people + + + align:start position:0% +into that system is so high that people +will spend the time to do this kind of + + align:start position:0% +will spend the time to do this kind of + + + align:start position:0% +will spend the time to do this kind of +stuff I guess I think more like the + + align:start position:0% +stuff I guess I think more like the + + + align:start position:0% +stuff I guess I think more like the +interesting if there's one company that + + align:start position:0% +interesting if there's one company that + + + align:start position:0% +interesting if there's one company that +dedicated to finding all the Gable + + align:start position:0% +dedicated to finding all the Gable + + + align:start position:0% +dedicated to finding all the Gable +grandmas and putting their emails and St + + align:start position:0% +grandmas and putting their emails and St + + + align:start position:0% +grandmas and putting their emails and St +oh interesting I see so basically having + + align:start position:0% +oh interesting I see so basically having + + + align:start position:0% +oh interesting I see so basically having +some database where it's like totally + + align:start position:0% +some database where it's like totally + + + align:start position:0% +some database where it's like totally +send spam to this person because yeah + + align:start position:0% +send spam to this person because yeah + + + align:start position:0% +send spam to this person because yeah +they I wouldn't be surprised if stuff + + align:start position:0% +they I wouldn't be surprised if stuff + + + align:start position:0% +they I wouldn't be surprised if stuff +like that existed um but I I don't know + + align:start position:0% +like that existed um but I I don't know + + + align:start position:0% +like that existed um but I I don't know +if they do um yeah so uh one last thing + + align:start position:0% +if they do um yeah so uh one last thing + + + align:start position:0% +if they do um yeah so uh one last thing +that I want to mention is that um and I + + align:start position:0% +that I want to mention is that um and I + + + align:start position:0% +that I want to mention is that um and I +alluded to this a bit earlier in the + + align:start position:0% +alluded to this a bit earlier in the + + + align:start position:0% +alluded to this a bit earlier in the +lecture is that some companies have + + align:start position:0% +lecture is that some companies have + + + align:start position:0% +lecture is that some companies have +taken to doing these things that they + + align:start position:0% +taken to doing these things that they + + + align:start position:0% +taken to doing these things that they +call hack backs right so the idea is + + align:start position:0% +call hack backs right so the idea is + + + align:start position:0% +call hack backs right so the idea is +that let's say that you're a bank + + align:start position:0% +that let's say that you're a bank + + + align:start position:0% +that let's say that you're a bank +someone tries to break into your bank + + align:start position:0% +someone tries to break into your bank + + + align:start position:0% +someone tries to break into your bank +steal enough information that bank will + + align:start position:0% +steal enough information that bank will + + + align:start position:0% +steal enough information that bank will +then of their own volition then go back + + align:start position:0% +then of their own volition then go back + + + align:start position:0% +then of their own volition then go back +to those hackers and try to do something + + align:start position:0% +to those hackers and try to do something + + + align:start position:0% +to those hackers and try to do something +where something may be as you know quote + + align:start position:0% +where something may be as you know quote + + + align:start position:0% +where something may be as you know quote +unquote innocuous as shutting down the + + align:start position:0% +unquote innocuous as shutting down the + + + align:start position:0% +unquote innocuous as shutting down the +botn net or maybe they try to steal + + align:start position:0% +botn net or maybe they try to steal + + + align:start position:0% +botn net or maybe they try to steal +their information back or things like + + align:start position:0% +their information back or things like + + + align:start position:0% +their information back or things like +this and this has actually become very + + align:start position:0% +this and this has actually become very + + + align:start position:0% +this and this has actually become very +um much more common than it used to be + + align:start position:0% +um much more common than it used to be + + + align:start position:0% +um much more common than it used to be +and one reason for this is that uh you + + align:start position:0% +and one reason for this is that uh you + + + align:start position:0% +and one reason for this is that uh you +know because the the legal system has + + align:start position:0% +know because the the legal system has + + + align:start position:0% +know because the the legal system has +been a little bit slow and adapting to + + align:start position:0% +been a little bit slow and adapting to + + + align:start position:0% +been a little bit slow and adapting to +some of these threats uh some of these + + align:start position:0% +some of these threats uh some of these + + + align:start position:0% +some of these threats uh some of these +institutions in particular software + + align:start position:0% +institutions in particular software + + + align:start position:0% +institutions in particular software +companies and banks are tired of waiting + + align:start position:0% +companies and banks are tired of waiting + + + align:start position:0% +companies and banks are tired of waiting +for government like their national + + align:start position:0% +for government like their national + + + align:start position:0% +for government like their national +government to deal with stuff and so + + align:start position:0% +government to deal with stuff and so + + + align:start position:0% +government to deal with stuff and so +what ends up happening is that uh for + + align:start position:0% +what ends up happening is that uh for + + + align:start position:0% +what ends up happening is that uh for +example there was this uh big botn net + + align:start position:0% +example there was this uh big botn net + + + align:start position:0% +example there was this uh big botn net +in 2013 that was hosting all kinds of + + align:start position:0% +in 2013 that was hosting all kinds of + + + align:start position:0% +in 2013 that was hosting all kinds of +like pirate goods and things like that + + align:start position:0% +like pirate goods and things like that + + + align:start position:0% +like pirate goods and things like that +and so this huge Coalition of like + + align:start position:0% +and so this huge Coalition of like + + + align:start position:0% +and so this huge Coalition of like +Microsoft American Express uh PayPal a + + align:start position:0% +Microsoft American Express uh PayPal a + + + align:start position:0% +Microsoft American Express uh PayPal a +bunch of them launched an operation to + + align:start position:0% +bunch of them launched an operation to + + + align:start position:0% +bunch of them launched an operation to +take down a botn net right they + + align:start position:0% +take down a botn net right they + + + align:start position:0% +take down a botn net right they +themselves took down the botn net they + + align:start position:0% +themselves took down the botn net they + + + align:start position:0% +themselves took down the botn net they +lurked around for a while they learned + + align:start position:0% +lurked around for a while they learned + + + align:start position:0% +lurked around for a while they learned +about where the command and control + + align:start position:0% +about where the command and control + + + align:start position:0% +about where the command and control +infrastructure was they actually went in + + align:start position:0% +infrastructure was they actually went in + + + align:start position:0% +infrastructure was they actually went in +there took control of the command and + + align:start position:0% +there took control of the command and + + + align:start position:0% +there took control of the command and +control infrastructure identified where + + align:start position:0% +control infrastructure identified where + + + align:start position:0% +control infrastructure identified where +all the enduser Bots were and they could + + align:start position:0% +all the enduser Bots were and they could + + + align:start position:0% +all the enduser Bots were and they could +send them you know messages or whatever + + align:start position:0% +send them you know messages or whatever + + + align:start position:0% +send them you know messages or whatever +saying you need to patch your machine + + align:start position:0% +saying you need to patch your machine + + + align:start position:0% +saying you need to patch your machine +right and so it's a very interesting + + align:start position:0% +right and so it's a very interesting + + + align:start position:0% +right and so it's a very interesting +area of intersection between security + + align:start position:0% +area of intersection between security + + + align:start position:0% +area of intersection between security +and the law right because what part of + + align:start position:0% +and the law right because what part of + + + align:start position:0% +and the law right because what part of +American law for example gave those + + align:start position:0% +American law for example gave those + + + align:start position:0% +American law for example gave those +companies the right to do that so uh + + align:start position:0% +companies the right to do that so uh + + + align:start position:0% +companies the right to do that so uh +what Microsoft lawyer said at least is + + align:start position:0% +what Microsoft lawyer said at least is + + + align:start position:0% +what Microsoft lawyer said at least is +that they said these botn nets were + + align:start position:0% +that they said these botn nets were + + + align:start position:0% +that they said these botn nets were +violating Microsoft trademarks right so + + align:start position:0% +violating Microsoft trademarks right so + + + align:start position:0% +violating Microsoft trademarks right so +for example if you sell pirated goods + + align:start position:0% +for example if you sell pirated goods + + + align:start position:0% +for example if you sell pirated goods +and you're saying like this is this is + + align:start position:0% +and you're saying like this is this is + + + align:start position:0% +and you're saying like this is this is +Windows for example but it's not + + align:start position:0% +Windows for example but it's not + + + align:start position:0% +Windows for example but it's not +actually windows or it didn't come from + + align:start position:0% +actually windows or it didn't come from + + + align:start position:0% +actually windows or it didn't come from +an official Channel then Microsoft says + + align:start position:0% +an official Channel then Microsoft says + + + align:start position:0% +an official Channel then Microsoft says +okay you're violating our trademark + + align:start position:0% +okay you're violating our trademark + + + align:start position:0% +okay you're violating our trademark +therefore you know we can hack your botn + + align:start position:0% +therefore you know we can hack your botn + + + align:start position:0% +therefore you know we can hack your botn +net it's a little interesting to see + + align:start position:0% +net it's a little interesting to see + + + align:start position:0% +net it's a little interesting to see +sort of how that how that that that leap + + align:start position:0% +sort of how that how that that that leap + + + align:start position:0% +sort of how that how that that that leap +of logic took place but the courts + + align:start position:0% +of logic took place but the courts + + + align:start position:0% +of logic took place but the courts +allowed it right and this is + + align:start position:0% +allowed it right and this is + + + align:start position:0% +allowed it right and this is +increasingly happening more and more and + + align:start position:0% +increasingly happening more and more and + + + align:start position:0% +increasingly happening more and more and +the banks in particular seem to be + + align:start position:0% +the banks in particular seem to be + + + align:start position:0% +the banks in particular seem to be +pretty upset about this because there + + align:start position:0% +pretty upset about this because there + + + align:start position:0% +pretty upset about this because there +seems to be a lot of sort of state level + + align:start position:0% +seems to be a lot of sort of state level + + + align:start position:0% +seems to be a lot of sort of state level +sponsorship of some of these banking + + align:start position:0% +sponsorship of some of these banking + + + align:start position:0% +sponsorship of some of these banking +hacks and you know the bankers care + + align:start position:0% +hacks and you know the bankers care + + + align:start position:0% +hacks and you know the bankers care +about the money and so when they lose + + align:start position:0% +about the money and so when they lose + + + align:start position:0% +about the money and so when they lose +this money they get very upset about + + align:start position:0% +this money they get very upset about + + + align:start position:0% +this money they get very upset about +that um and so it's interesting to see + + align:start position:0% +that um and so it's interesting to see + + + align:start position:0% +that um and so it's interesting to see +how some of the uh sort of Burden for + + align:start position:0% +how some of the uh sort of Burden for + + + align:start position:0% +how some of the uh sort of Burden for +doing cyber security in particular + + align:start position:0% +doing cyber security in particular + + + align:start position:0% +doing cyber security in particular +offensive operations has now shifted a + + align:start position:0% +offensive operations has now shifted a + + + align:start position:0% +offensive operations has now shifted a +little bit more to the the private + + align:start position:0% +little bit more to the the private + + + align:start position:0% +little bit more to the the private +sector so it's not quite clear what the + + align:start position:0% +sector so it's not quite clear what the + + + align:start position:0% +sector so it's not quite clear what the +long-term implications of that are okay + + align:start position:0% +long-term implications of that are okay + + + align:start position:0% +long-term implications of that are okay +with that that's the end of the lecture + + align:start position:0% +with that that's the end of the lecture + + + align:start position:0% +with that that's the end of the lecture +uh and I guess we will see you on uh + + align:start position:0% +uh and I guess we will see you on uh + + + align:start position:0% +uh and I guess we will see you on uh +Wednesday and we will go through the + + align:start position:0% +Wednesday and we will go through the + + + align:start position:0% +Wednesday and we will go through the +projects \ No newline at end of file diff --git a/8p_4qP03AM0.txt b/8p_4qP03AM0.txt new file mode 100644 index 0000000000000000000000000000000000000000..7df1279d079e07fdea0af330e589be30eff33ad3 --- /dev/null +++ b/8p_4qP03AM0.txt @@ -0,0 +1,827 @@ +align:start position:0% + +in this lecture we'll discuss how linear + + align:start position:0% +in this lecture we'll discuss how linear + + + align:start position:0% +in this lecture we'll discuss how linear +optimization is used to design radiation + + align:start position:0% +optimization is used to design radiation + + + align:start position:0% +optimization is used to design radiation +therapy treatments for cancer patients + + align:start position:0% +therapy treatments for cancer patients + + + align:start position:0% +therapy treatments for cancer patients +cancer is the second leading cause of + + align:start position:0% +cancer is the second leading cause of + + + align:start position:0% +cancer is the second leading cause of +death in the United States + + align:start position:0% +death in the United States + + + align:start position:0% +death in the United States +second only to heart disease there were + + align:start position:0% +second only to heart disease there were + + + align:start position:0% +second only to heart disease there were +an estimated 570 thousand deaths in 2013 + + align:start position:0% +an estimated 570 thousand deaths in 2013 + + + align:start position:0% +an estimated 570 thousand deaths in 2013 +due to cancer additionally over 1.6 + + align:start position:0% +due to cancer additionally over 1.6 + + + align:start position:0% +due to cancer additionally over 1.6 +million new cases of cancer will be + + align:start position:0% +million new cases of cancer will be + + + align:start position:0% +million new cases of cancer will be +diagnosed in the United States in 2013 + + align:start position:0% +diagnosed in the United States in 2013 + + + align:start position:0% +diagnosed in the United States in 2013 +these trends are also seen throughout + + align:start position:0% +these trends are also seen throughout + + + align:start position:0% +these trends are also seen throughout +the world worldwide cancer is a leading + + align:start position:0% +the world worldwide cancer is a leading + + + align:start position:0% +the world worldwide cancer is a leading +cause of death with 8.2 million deaths + + align:start position:0% +cause of death with 8.2 million deaths + + + align:start position:0% +cause of death with 8.2 million deaths +in 2012 cancer can be treated using + + align:start position:0% +in 2012 cancer can be treated using + + + align:start position:0% +in 2012 cancer can be treated using +radiation therapy where beams of + + align:start position:0% +radiation therapy where beams of + + + align:start position:0% +radiation therapy where beams of +high-energy photons are fired into the + + align:start position:0% +high-energy photons are fired into the + + + align:start position:0% +high-energy photons are fired into the +patient to kill cancerous cells this is + + align:start position:0% +patient to kill cancerous cells this is + + + align:start position:0% +patient to kill cancerous cells this is +a very common form of treatment for many + + align:start position:0% +a very common form of treatment for many + + + align:start position:0% +a very common form of treatment for many +types of cancers and in the United + + align:start position:0% +types of cancers and in the United + + + align:start position:0% +types of cancers and in the United +States about half of all cancer patients + + align:start position:0% +States about half of all cancer patients + + + align:start position:0% +States about half of all cancer patients +undergo some form of radiation therapy + + align:start position:0% +undergo some form of radiation therapy + + + align:start position:0% +undergo some form of radiation therapy +radiation therapy has a history going + + align:start position:0% +radiation therapy has a history going + + + align:start position:0% +radiation therapy has a history going +back to the late 1800s x-rays were + + align:start position:0% +back to the late 1800s x-rays were + + + align:start position:0% +back to the late 1800s x-rays were +discovered by vilem roentgen in 1895 who + + align:start position:0% +discovered by vilem roentgen in 1895 who + + + align:start position:0% +discovered by vilem roentgen in 1895 who +was later awarded the first Nobel Prize + + align:start position:0% +was later awarded the first Nobel Prize + + + align:start position:0% +was later awarded the first Nobel Prize +in Physics shortly after the discovery + + align:start position:0% +in Physics shortly after the discovery + + + align:start position:0% +in Physics shortly after the discovery +x-ray started being used to treat skin + + align:start position:0% +x-ray started being used to treat skin + + + align:start position:0% +x-ray started being used to treat skin +cancers this image shows an x-ray of + + align:start position:0% +cancers this image shows an x-ray of + + + align:start position:0% +cancers this image shows an x-ray of +rankin's wife's hand you can see the + + align:start position:0% +rankin's wife's hand you can see the + + + align:start position:0% +rankin's wife's hand you can see the +bones in her hand as well as her running + + align:start position:0% +bones in her hand as well as her running + + + align:start position:0% +bones in her hand as well as her running +ring on her finger a few years later in + + align:start position:0% +ring on her finger a few years later in + + + align:start position:0% +ring on her finger a few years later in +1898 radium was discovered by Marie and + + align:start position:0% +1898 radium was discovered by Marie and + + + align:start position:0% +1898 radium was discovered by Marie and +Pierre Curie they won the Nobel Prize + + align:start position:0% +Pierre Curie they won the Nobel Prize + + + align:start position:0% +Pierre Curie they won the Nobel Prize +for this discovery in 1911 radium + + align:start position:0% +for this discovery in 1911 radium + + + align:start position:0% +for this discovery in 1911 radium +started being used to treat cancer as + + align:start position:0% +started being used to treat cancer as + + + align:start position:0% +started being used to treat cancer as +well as other diseases later in the + + align:start position:0% +well as other diseases later in the + + + align:start position:0% +well as other diseases later in the +1900s the first radiation delivery + + align:start position:0% +1900s the first radiation delivery + + + align:start position:0% +1900s the first radiation delivery +machines called linear accelerators were + + align:start position:0% +machines called linear accelerators were + + + align:start position:0% +machines called linear accelerators were +developed then computed tomography or CT + + align:start position:0% +developed then computed tomography or CT + + + align:start position:0% +developed then computed tomography or CT +scans were invented in 1971 these + + align:start position:0% +scans were invented in 1971 these + + + align:start position:0% +scans were invented in 1971 these +discoveries led to the invention of + + align:start position:0% +discoveries led to the invention of + + + align:start position:0% +discoveries led to the invention of +intensity-modulated + + align:start position:0% +intensity-modulated + + + align:start position:0% +intensity-modulated +radiation therapy or imrt in the early + + align:start position:0% +radiation therapy or imrt in the early + + + align:start position:0% +radiation therapy or imrt in the early +1980s the invention of IMRT + + align:start position:0% +1980s the invention of IMRT + + + align:start position:0% +1980s the invention of IMRT +significantly improved to the ability of + + align:start position:0% +significantly improved to the ability of + + + align:start position:0% +significantly improved to the ability of +radiation therapy to target cancerous + + align:start position:0% +radiation therapy to target cancerous + + + align:start position:0% +radiation therapy to target cancerous +cells to reach the tumor radiation + + align:start position:0% +cells to reach the tumor radiation + + + align:start position:0% +cells to reach the tumor radiation +passes through healthy tissue and + + align:start position:0% +passes through healthy tissue and + + + align:start position:0% +passes through healthy tissue and +therefore damages both healthy and + + align:start position:0% +therefore damages both healthy and + + + align:start position:0% +therefore damages both healthy and +cancerous tissue this damage to healthy + + align:start position:0% +cancerous tissue this damage to healthy + + + align:start position:0% +cancerous tissue this damage to healthy +tissue can lead to undesirable side + + align:start position:0% +tissue can lead to undesirable side + + + align:start position:0% +tissue can lead to undesirable side +effects that reduce post treatment + + align:start position:0% +effects that reduce post treatment + + + align:start position:0% +effects that reduce post treatment +quality of life for example blistering + + align:start position:0% +quality of life for example blistering + + + align:start position:0% +quality of life for example blistering +and burning of skin can occur because of + + align:start position:0% +and burning of skin can occur because of + + + align:start position:0% +and burning of skin can occur because of +the damage to healthy skin cells for + + align:start position:0% +the damage to healthy skin cells for + + + align:start position:0% +the damage to healthy skin cells for +this reason we want the dose to fit the + + align:start position:0% +this reason we want the dose to fit the + + + align:start position:0% +this reason we want the dose to fit the +tumor as closely as possible to reduce + + align:start position:0% +tumor as closely as possible to reduce + + + align:start position:0% +tumor as closely as possible to reduce +the dose to healthy tissue this became + + align:start position:0% +the dose to healthy tissue this became + + + align:start position:0% +the dose to healthy tissue this became +possible with the invention of IMRT in + + align:start position:0% +possible with the invention of IMRT in + + + align:start position:0% +possible with the invention of IMRT in +IMRT the intensity profile of each beam + + align:start position:0% +IMRT the intensity profile of each beam + + + align:start position:0% +IMRT the intensity profile of each beam +is non-uniform before I MRT each beam + + align:start position:0% +is non-uniform before I MRT each beam + + + align:start position:0% +is non-uniform before I MRT each beam +had to have the same intensity so the + + align:start position:0% +had to have the same intensity so the + + + align:start position:0% +had to have the same intensity so the +tumor could not be targeted very well + + align:start position:0% +tumor could not be targeted very well + + + align:start position:0% +tumor could not be targeted very well +but by using non uniform intensity + + align:start position:0% +but by using non uniform intensity + + + align:start position:0% +but by using non uniform intensity +profiles the radiation dose can better + + align:start position:0% +profiles the radiation dose can better + + + align:start position:0% +profiles the radiation dose can better +fit the tumor let's see what this looks + + align:start position:0% +fit the tumor let's see what this looks + + + align:start position:0% +fit the tumor let's see what this looks +like in this image we have a person's + + align:start position:0% +like in this image we have a person's + + + align:start position:0% +like in this image we have a person's +body outlined in black and then the + + align:start position:0% +body outlined in black and then the + + + align:start position:0% +body outlined in black and then the +target or tumor and two critical + + align:start position:0% +target or tumor and two critical + + + align:start position:0% +target or tumor and two critical +structures also outlined we would like + + align:start position:0% +structures also outlined we would like + + + align:start position:0% +structures also outlined we would like +to maximize the radiation to the target + + align:start position:0% +to maximize the radiation to the target + + + align:start position:0% +to maximize the radiation to the target +while minimizing the dose to healthy + + align:start position:0% +while minimizing the dose to healthy + + + align:start position:0% +while minimizing the dose to healthy +tissue and especially to the critical + + align:start position:0% +tissue and especially to the critical + + + align:start position:0% +tissue and especially to the critical +structures using traditional radiation + + align:start position:0% +structures using traditional radiation + + + align:start position:0% +structures using traditional radiation +therapy each of the three beams has the + + align:start position:0% +therapy each of the three beams has the + + + align:start position:0% +therapy each of the three beams has the +same intensity throughout the beam so to + + align:start position:0% +same intensity throughout the beam so to + + + align:start position:0% +same intensity throughout the beam so to +deliver enough radiation to the tumor we + + align:start position:0% +deliver enough radiation to the tumor we + + + align:start position:0% +deliver enough radiation to the tumor we +also have to deliver a significant + + align:start position:0% +also have to deliver a significant + + + align:start position:0% +also have to deliver a significant +amount of radiation to the critical + + align:start position:0% +amount of radiation to the critical + + + align:start position:0% +amount of radiation to the critical +structures and to other healthy tissue + + align:start position:0% +structures and to other healthy tissue + + + align:start position:0% +structures and to other healthy tissue +but by using IMRT we can change the + + align:start position:0% +but by using IMRT we can change the + + + align:start position:0% +but by using IMRT we can change the +intensity throughout each beam to make + + align:start position:0% +intensity throughout each beam to make + + + align:start position:0% +intensity throughout each beam to make +it non uniform some pieces of the beam + + align:start position:0% +it non uniform some pieces of the beam + + + align:start position:0% +it non uniform some pieces of the beam +will have a higher intensity than others + + align:start position:0% +will have a higher intensity than others + + + align:start position:0% +will have a higher intensity than others +this allows us to deliver the necessary + + align:start position:0% +this allows us to deliver the necessary + + + align:start position:0% +this allows us to deliver the necessary +amount of radiation to the tumor while + + align:start position:0% +amount of radiation to the tumor while + + + align:start position:0% +amount of radiation to the tumor while +minimizing + + align:start position:0% +minimizing + + + align:start position:0% +minimizing +the total radiation to healthy tissue + + align:start position:0% +the total radiation to healthy tissue + + + align:start position:0% +the total radiation to healthy tissue +and thus the critical structures get + + align:start position:0% +and thus the critical structures get + + + align:start position:0% +and thus the critical structures get +significantly less radiation each of the + + align:start position:0% +significantly less radiation each of the + + + align:start position:0% +significantly less radiation each of the +pieces of the beam is referred to as a + + align:start position:0% +pieces of the beam is referred to as a + + + align:start position:0% +pieces of the beam is referred to as a +beam lit so in IMRT we decide the + + align:start position:0% +beam lit so in IMRT we decide the + + + align:start position:0% +beam lit so in IMRT we decide the +intensity of each of the beam lifts so + + align:start position:0% +intensity of each of the beam lifts so + + + align:start position:0% +intensity of each of the beam lifts so +that we can target the tumor with + + align:start position:0% +that we can target the tumor with + + + align:start position:0% +that we can target the tumor with +radiation while minimizing the radiation + + align:start position:0% +radiation while minimizing the radiation + + + align:start position:0% +radiation while minimizing the radiation +to healthy tissue so in designing and + + align:start position:0% +to healthy tissue so in designing and + + + align:start position:0% +to healthy tissue so in designing and +IMRT treatment the fundamental problem + + align:start position:0% +IMRT treatment the fundamental problem + + + align:start position:0% +IMRT treatment the fundamental problem +is how should the beam LED intensities + + align:start position:0% +is how should the beam LED intensities + + + align:start position:0% +is how should the beam LED intensities +be selected to deliver a therapeutic + + align:start position:0% +be selected to deliver a therapeutic + + + align:start position:0% +be selected to deliver a therapeutic +dose to the tumor and to minimize damage + + align:start position:0% +dose to the tumor and to minimize damage + + + align:start position:0% +dose to the tumor and to minimize damage +to healthy tissue this is the problem + + align:start position:0% +to healthy tissue this is the problem + + + align:start position:0% +to healthy tissue this is the problem +that we'll address in this lecture using + + align:start position:0% +that we'll address in this lecture using + + + align:start position:0% +that we'll address in this lecture using +linear optimization + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/AqCz_b7VJK8.txt b/AqCz_b7VJK8.txt new file mode 100644 index 0000000000000000000000000000000000000000..72880a281af24e80f7824461db4e57056c438385 --- /dev/null +++ b/AqCz_b7VJK8.txt @@ -0,0 +1,10459 @@ +align:start position:0% + +today + + align:start position:0% +today + + + align:start position:0% +today +uh clearly i am a noble gas + + align:start position:0% +uh clearly i am a noble gas + + + align:start position:0% +uh clearly i am a noble gas +um and so + + align:start position:0% +um and so + + + align:start position:0% +um and so +thanks to is actually the ta's idea so + + align:start position:0% +thanks to is actually the ta's idea so + + + align:start position:0% +thanks to is actually the ta's idea so +and i was like of course that sounds + + align:start position:0% +and i was like of course that sounds + + + align:start position:0% +and i was like of course that sounds +awesome so + + align:start position:0% +awesome so + + + align:start position:0% +awesome so +um i hope you guys have a fantastic + + align:start position:0% +um i hope you guys have a fantastic + + + align:start position:0% +um i hope you guys have a fantastic +halloween + + align:start position:0% +halloween + + + align:start position:0% +halloween +obviously what you want to do is any + + align:start position:0% +obviously what you want to do is any + + + align:start position:0% +obviously what you want to do is any +kind of trick-or-treating or + + align:start position:0% +kind of trick-or-treating or + + + align:start position:0% +kind of trick-or-treating or +partying you know the drill you bring + + align:start position:0% +partying you know the drill you bring + + + align:start position:0% +partying you know the drill you bring +your periodic table because you never + + align:start position:0% +your periodic table because you never + + + align:start position:0% +your periodic table because you never +know + + align:start position:0% +know + + + align:start position:0% +know +and and that's what happened you know so + + align:start position:0% +and and that's what happened you know so + + + align:start position:0% +and and that's what happened you know so +on sunday + + align:start position:0% +on sunday + + + align:start position:0% +on sunday +right before the exam i got this and um + + align:start position:0% +right before the exam i got this and um + + + align:start position:0% +right before the exam i got this and um +okay so so this is uh charles and + + align:start position:0% +okay so so this is uh charles and + + + align:start position:0% +okay so so this is uh charles and +raymond and they're saying + + align:start position:0% +raymond and they're saying + + + align:start position:0% +raymond and they're saying +we wanted to celebrate the sox victory + + align:start position:0% +we wanted to celebrate the sox victory + + + align:start position:0% +we wanted to celebrate the sox victory +in boston + + align:start position:0% +in boston + + + align:start position:0% +in boston +but because the midterm was the next day + + align:start position:0% +but because the midterm was the next day + + + align:start position:0% +but because the midterm was the next day +we brought along our periodic table to + + align:start position:0% +we brought along our periodic table to + + + align:start position:0% +we brought along our periodic table to +study + + align:start position:0% +study + + + align:start position:0% +study +there were so many people moving around + + align:start position:0% +there were so many people moving around + + + align:start position:0% +there were so many people moving around +it felt like we were in a sea + + align:start position:0% +it felt like we were in a sea + + + align:start position:0% +it felt like we were in a sea +of electrons and of course the only + + align:start position:0% +of electrons and of course the only + + + align:start position:0% +of electrons and of course the only +thing that could have improved on that + + align:start position:0% +thing that could have improved on that + + + align:start position:0% +thing that could have improved on that +was actually like a little dance video + + align:start position:0% +was actually like a little dance video + + + align:start position:0% +was actually like a little dance video +but that'll probably come i'm sure + + align:start position:0% +but that'll probably come i'm sure + + + align:start position:0% +but that'll probably come i'm sure +they're on that next um but see they + + align:start position:0% +they're on that next um but see they + + + align:start position:0% +they're on that next um but see they +brought it + + align:start position:0% +brought it + + + align:start position:0% +brought it +not just to study for the exam because + + align:start position:0% +not just to study for the exam because + + + align:start position:0% +not just to study for the exam because +they didn't know if it was going to be + + align:start position:0% +they didn't know if it was going to be + + + align:start position:0% +they didn't know if it was going to be +important or not + + align:start position:0% +important or not + + + align:start position:0% +important or not +at the rally you never know right so + + align:start position:0% +at the rally you never know right so + + + align:start position:0% +at the rally you never know right so +so make sure you have your periodic + + align:start position:0% +so make sure you have your periodic + + + align:start position:0% +so make sure you have your periodic +table with you um + + align:start position:0% +table with you um + + + align:start position:0% +table with you um +now uh okay oh + + align:start position:0% +now uh okay oh + + + align:start position:0% +now uh okay oh +yeah they mentioned the exam so speak + + align:start position:0% +yeah they mentioned the exam so speak + + + align:start position:0% +yeah they mentioned the exam so speak +speaking of the exam um here are the + + align:start position:0% +speaking of the exam um here are the + + + align:start position:0% +speaking of the exam um here are the +results + + align:start position:0% +results + + + align:start position:0% +results +and um you can see that there's a pretty + + align:start position:0% +and um you can see that there's a pretty + + + align:start position:0% +and um you can see that there's a pretty +wide distribution + + align:start position:0% +wide distribution + + + align:start position:0% +wide distribution +um you can also see the average is a 77 + + align:start position:0% +um you can also see the average is a 77 + + + align:start position:0% +um you can also see the average is a 77 +and just to remind you that's that's + + align:start position:0% +and just to remind you that's that's + + + align:start position:0% +and just to remind you that's that's +about here + + align:start position:0% +about here + + + align:start position:0% +about here +just to remind you these uh these uh + + align:start position:0% +just to remind you these uh these uh + + + align:start position:0% +just to remind you these uh these uh +marks 85 + + align:start position:0% +marks 85 + + + align:start position:0% +marks 85 +that's the a range this is the b range + + align:start position:0% +that's the a range this is the b range + + + align:start position:0% +that's the a range this is the b range +right so the average was in the solid b + + align:start position:0% +right so the average was in the solid b + + + align:start position:0% +right so the average was in the solid b +range territory um + + align:start position:0% +range territory um + + + align:start position:0% +range territory um +and and then and so it goes um + + align:start position:0% +and and then and so it goes um + + + align:start position:0% +and and then and so it goes um +the standard deviation was 12. + + align:start position:0% +the standard deviation was 12. + + + align:start position:0% +the standard deviation was 12. +now i could tell + + align:start position:0% +now i could tell + + + align:start position:0% +now i could tell +you know exam one i think a lot of the + + align:start position:0% +you know exam one i think a lot of the + + + align:start position:0% +you know exam one i think a lot of the +topics of exam one + + align:start position:0% +topics of exam one + + + align:start position:0% +topics of exam one +many of you had already seen and i think + + align:start position:0% +many of you had already seen and i think + + + align:start position:0% +many of you had already seen and i think +in this exam + + align:start position:0% +in this exam + + + align:start position:0% +in this exam +some of you had not seen some of these + + align:start position:0% +some of you had not seen some of these + + + align:start position:0% +some of you had not seen some of these +topics especially like the crystal + + align:start position:0% +topics especially like the crystal + + + align:start position:0% +topics especially like the crystal +crystallography but also even the + + align:start position:0% +crystallography but also even the + + + align:start position:0% +crystallography but also even the +molecular orbitals the band structure + + align:start position:0% +molecular orbitals the band structure + + + align:start position:0% +molecular orbitals the band structure +and and i could tell that you know so + + align:start position:0% +and and i could tell that you know so + + + align:start position:0% +and and i could tell that you know so +some people were a little bit + + align:start position:0% +some people were a little bit + + + align:start position:0% +some people were a little bit +uh maybe uh you know you had to work a + + align:start position:0% +uh maybe uh you know you had to work a + + + align:start position:0% +uh maybe uh you know you had to work a +little harder maybe a little + + align:start position:0% +little harder maybe a little + + + align:start position:0% +little harder maybe a little +bit stressed and i could sense uh some + + align:start position:0% +bit stressed and i could sense uh some + + + align:start position:0% +bit stressed and i could sense uh some +of that + + align:start position:0% +of that + + + align:start position:0% +of that +uh but you know when i when i get + + align:start position:0% +uh but you know when i when i get + + + align:start position:0% +uh but you know when i when i get +stressed what i do + + align:start position:0% +stressed what i do + + + align:start position:0% +stressed what i do +is i need to kind of de-stress somehow + + align:start position:0% +is i need to kind of de-stress somehow + + + align:start position:0% +is i need to kind of de-stress somehow +and sometimes you know some people + + align:start position:0% +and sometimes you know some people + + + align:start position:0% +and sometimes you know some people +listen to music + + align:start position:0% +listen to music + + + align:start position:0% +listen to music +some of the other things i always like + + align:start position:0% +some of the other things i always like + + + align:start position:0% +some of the other things i always like +comedy + + align:start position:0% +comedy + + + align:start position:0% +comedy +as a way of of relaxing and so what i do + + align:start position:0% +as a way of of relaxing and so what i do + + + align:start position:0% +as a way of of relaxing and so what i do +is i'll google like for articles about + + align:start position:0% +is i'll google like for articles about + + + align:start position:0% +is i'll google like for articles about +about harvard um and i found + + align:start position:0% +about harvard um and i found + + + align:start position:0% +about harvard um and i found +and so i found this one + + align:start position:0% +and so i found this one + + + align:start position:0% +and so i found this one +this is actually an article in the + + align:start position:0% +this is actually an article in the + + + align:start position:0% +this is actually an article in the +crimson and you know and so + + align:start position:0% +crimson and you know and so + + + align:start position:0% +crimson and you know and so +some a few years ago and uh the most + + align:start position:0% +some a few years ago and uh the most + + + align:start position:0% +some a few years ago and uh the most +common grade at harvard is actually an a + + align:start position:0% +common grade at harvard is actually an a + + + align:start position:0% +common grade at harvard is actually an a +an a a solid a the most common grade + + align:start position:0% +an a a solid a the most common grade + + + align:start position:0% +an a a solid a the most common grade +um um and i like there's a okay + + align:start position:0% +um um and i like there's a okay + + + align:start position:0% +um um and i like there's a okay +suspicion that the college employs a + + align:start position:0% +suspicion that the college employs a + + + align:start position:0% +suspicion that the college employs a +softer grading standard than many of its + + align:start position:0% +softer grading standard than many of its + + + align:start position:0% +softer grading standard than many of its +peer + + align:start position:0% +peer + + + align:start position:0% +peer +institutions you think if everyone i + + align:start position:0% +institutions you think if everyone i + + + align:start position:0% +institutions you think if everyone i +mean + + align:start position:0% +mean + + + align:start position:0% +mean +if everyone's getting an a you think i i + + align:start position:0% +if everyone's getting an a you think i i + + + align:start position:0% +if everyone's getting an a you think i i +mean but the thing is + + align:start position:0% +mean but the thing is + + + align:start position:0% +mean but the thing is +uh so what i wanted to point out is like + + align:start position:0% +uh so what i wanted to point out is like + + + align:start position:0% +uh so what i wanted to point out is like +there's a difference + + align:start position:0% +there's a difference + + + align:start position:0% +there's a difference +right and it's not just about uh okay + + align:start position:0% +right and it's not just about uh okay + + + align:start position:0% +right and it's not just about uh okay +your privilege therefore you deserve an + + align:start position:0% +your privilege therefore you deserve an + + + align:start position:0% +your privilege therefore you deserve an +a + + align:start position:0% +a + + + align:start position:0% +a +um whereas we know that that actually + + align:start position:0% +um whereas we know that that actually + + + align:start position:0% +um whereas we know that that actually +takes + + align:start position:0% +takes + + + align:start position:0% +takes +work that's not the point i want to make + + align:start position:0% +work that's not the point i want to make + + + align:start position:0% +work that's not the point i want to make +the point i want to make is that we know + + align:start position:0% +the point i want to make is that we know + + + align:start position:0% +the point i want to make is that we know +also what to do when we miss things + + align:start position:0% +also what to do when we miss things + + + align:start position:0% +also what to do when we miss things +we know what to do when we don't get + + align:start position:0% +we know what to do when we don't get + + + align:start position:0% +we know what to do when we don't get +things right right + + align:start position:0% +things right right + + + align:start position:0% +things right right +that's when you do the work you know so + + align:start position:0% +that's when you do the work you know so + + + align:start position:0% +that's when you do the work you know so +wherever you are + + align:start position:0% +wherever you are + + + align:start position:0% +wherever you are +on this curve go back and figure out + + align:start position:0% +on this curve go back and figure out + + + align:start position:0% +on this curve go back and figure out +what didn't work + + align:start position:0% +what didn't work + + + align:start position:0% +what didn't work +what did you miss figure that out + + align:start position:0% +what did you miss figure that out + + + align:start position:0% +what did you miss figure that out +because that's where you learn + + align:start position:0% +because that's where you learn + + + align:start position:0% +because that's where you learn +right i mean there's a thomas edison who + + align:start position:0% +right i mean there's a thomas edison who + + + align:start position:0% +right i mean there's a thomas edison who +said i never failed + + align:start position:0% +said i never failed + + + align:start position:0% +said i never failed +i just did 10 000 experiments that + + align:start position:0% +i just did 10 000 experiments that + + + align:start position:0% +i just did 10 000 experiments that +didn't work + + align:start position:0% +didn't work + + + align:start position:0% +didn't work +right that you know you got to get + + align:start position:0% +right that you know you got to get + + + align:start position:0% +right that you know you got to get +through that you got to know that it + + align:start position:0% +through that you got to know that it + + + align:start position:0% +through that you got to know that it +takes hard work and that's the thing + + align:start position:0% +takes hard work and that's the thing + + + align:start position:0% +takes hard work and that's the thing +that we know here + + align:start position:0% +that we know here + + + align:start position:0% +that we know here +that's the difference so please make + + align:start position:0% +that's the difference so please make + + + align:start position:0% +that's the difference so please make +sure you do that with exam two + + align:start position:0% +sure you do that with exam two + + + align:start position:0% +sure you do that with exam two +we are all here to help you continue + + align:start position:0% +we are all here to help you continue + + + align:start position:0% +we are all here to help you continue +learning + + align:start position:0% +learning + + + align:start position:0% +learning +on the noble gas anyway + + align:start position:0% +on the noble gas anyway + + + align:start position:0% +on the noble gas anyway +okay and speaking of continuing to learn + + align:start position:0% +okay and speaking of continuing to learn + + + align:start position:0% +okay and speaking of continuing to learn +um right where were we x-rays + + align:start position:0% +um right where were we x-rays + + + align:start position:0% +um right where were we x-rays +so the last time now um + + align:start position:0% +so the last time now um + + + align:start position:0% +so the last time now um +uh on friday we had sort of you know + + align:start position:0% +uh on friday we had sort of you know + + + align:start position:0% +uh on friday we had sort of you know +some other things going on but i also + + align:start position:0% +some other things going on but i also + + + align:start position:0% +some other things going on but i also +was trying to teach you guys about + + align:start position:0% +was trying to teach you guys about + + + align:start position:0% +was trying to teach you guys about +x-rays + + align:start position:0% +x-rays + + + align:start position:0% +x-rays +and because in type and + + align:start position:0% +and because in type and + + + align:start position:0% +and because in type and +and what we did is we learned how + + align:start position:0% +and what we did is we learned how + + + align:start position:0% +and what we did is we learned how +they're generated right remember that + + align:start position:0% +they're generated right remember that + + + align:start position:0% +they're generated right remember that +the renkin + + align:start position:0% +the renkin + + + align:start position:0% +the renkin +experiments right um and so i want to + + align:start position:0% +experiments right um and so i want to + + + align:start position:0% +experiments right um and so i want to +pick up here with the kinds of x-rays + + align:start position:0% +pick up here with the kinds of x-rays + + + align:start position:0% +pick up here with the kinds of x-rays +that we have + + align:start position:0% +that we have + + + align:start position:0% +that we have +there are two kinds of x-rays right um + + align:start position:0% +there are two kinds of x-rays right um + + + align:start position:0% +there are two kinds of x-rays right um +and and we learned about those on on + + align:start position:0% +and and we learned about those on on + + + align:start position:0% +and and we learned about those on on +friday and i want to just remind you + + align:start position:0% +friday and i want to just remind you + + + align:start position:0% +friday and i want to just remind you +about those + + align:start position:0% +about those + + + align:start position:0% +about those +and i also want to um show you a video + + align:start position:0% +and i also want to um show you a video + + + align:start position:0% +and i also want to um show you a video +uh to kind of recapture what they are + + align:start position:0% +uh to kind of recapture what they are + + + align:start position:0% +uh to kind of recapture what they are +and the the the first kind of x-ray + + align:start position:0% + + + + align:start position:0% + +remember we plotted this as intensity + + align:start position:0% +remember we plotted this as intensity + + + align:start position:0% +remember we plotted this as intensity +and i'm not going to + + align:start position:0% + + + + align:start position:0% + +i'm not going to draw the cathode ray + + align:start position:0% +i'm not going to draw the cathode ray + + + align:start position:0% +i'm not going to draw the cathode ray +tube again and the experiment that + + align:start position:0% +tube again and the experiment that + + + align:start position:0% +tube again and the experiment that +renkin did and all that + + align:start position:0% +renkin did and all that + + + align:start position:0% +renkin did and all that +but but i'm going to just jump to the + + align:start position:0% +but but i'm going to just jump to the + + + align:start position:0% +but but i'm going to just jump to the +two kinds of x-rays that you get + + align:start position:0% +two kinds of x-rays that you get + + + align:start position:0% +two kinds of x-rays that you get +right and so if you plot the + + align:start position:0% +right and so if you plot the + + + align:start position:0% +right and so if you plot the +the wavelength of the x-ray versus the + + align:start position:0% +the wavelength of the x-ray versus the + + + align:start position:0% +the wavelength of the x-ray versus the +intensity of the x-ray + + align:start position:0% +intensity of the x-ray + + + align:start position:0% +intensity of the x-ray +right then one kind is the + + align:start position:0% +right then one kind is the + + + align:start position:0% +right then one kind is the +bremsstrahlung + + align:start position:0% +bremsstrahlung + + + align:start position:0% +bremsstrahlung +which comes from that that electron + + align:start position:0% +which comes from that that electron + + + align:start position:0% +which comes from that that electron +getting slowed down + + align:start position:0% +getting slowed down + + + align:start position:0% +getting slowed down +and and if it slows down it emits + + align:start position:0% +and and if it slows down it emits + + + align:start position:0% +and and if it slows down it emits +radiation + + align:start position:0% +radiation + + + align:start position:0% +radiation +in a continuous spectrum right and so + + align:start position:0% +in a continuous spectrum right and so + + + align:start position:0% +in a continuous spectrum right and so +so you might get you know remember we + + align:start position:0% +so you might get you know remember we + + + align:start position:0% +so you might get you know remember we +we sort of drew these these + + align:start position:0% +we sort of drew these these + + + align:start position:0% +we sort of drew these these +yeah okay and and this might be you know + + align:start position:0% +yeah okay and and this might be you know + + + align:start position:0% +yeah okay and and this might be you know +this would be like the incident + + align:start position:0% +this would be like the incident + + + align:start position:0% +this would be like the incident +electron energy right incident + + align:start position:0% +electron energy right incident + + + align:start position:0% +electron energy right incident +let's say incident um + + align:start position:0% +let's say incident um + + + align:start position:0% +let's say incident um +energy of the electron okay maybe like + + align:start position:0% +energy of the electron okay maybe like + + + align:start position:0% +energy of the electron okay maybe like +that's uh + + align:start position:0% +that's uh + + + align:start position:0% +that's uh +okay i don't know like 10 kav 10 + + align:start position:0% +okay i don't know like 10 kav 10 + + + align:start position:0% +okay i don't know like 10 kav 10 +kv and then up here the incident energy + + align:start position:0% +kv and then up here the incident energy + + + align:start position:0% +kv and then up here the incident energy +of the electron was + + align:start position:0% +of the electron was + + + align:start position:0% +of the electron was +you know something like maybe 30 kev + + align:start position:0% +you know something like maybe 30 kev + + + align:start position:0% +you know something like maybe 30 kev +right and so + + align:start position:0% +right and so + + + align:start position:0% +right and so +you see that it it as you as you hit + + align:start position:0% +you see that it it as you as you hit + + + align:start position:0% +you see that it it as you as you hit +that anode that remember what rinkin did + + align:start position:0% +that anode that remember what rinkin did + + + align:start position:0% +that anode that remember what rinkin did +he took a cathode ray tube and he + + align:start position:0% +he took a cathode ray tube and he + + + align:start position:0% +he took a cathode ray tube and he +upped the voltage so he really cranked + + align:start position:0% +upped the voltage so he really cranked + + + align:start position:0% +upped the voltage so he really cranked +up the voltage so those electrons coming + + align:start position:0% +up the voltage so those electrons coming + + + align:start position:0% +up the voltage so those electrons coming +off the cathode + + align:start position:0% +off the cathode + + + align:start position:0% +off the cathode +are going really fast right and then + + align:start position:0% +are going really fast right and then + + + align:start position:0% +are going really fast right and then +what he did is he put a piece of metal + + align:start position:0% +what he did is he put a piece of metal + + + align:start position:0% +what he did is he put a piece of metal +in their way + + align:start position:0% +in their way + + + align:start position:0% +in their way +and and what happened is those really + + align:start position:0% +and and what happened is those really + + + align:start position:0% +and and what happened is those really +high energy electrons + + align:start position:0% +high energy electrons + + + align:start position:0% +high energy electrons +they see those metal atoms and sometimes + + align:start position:0% +they see those metal atoms and sometimes + + + align:start position:0% +they see those metal atoms and sometimes +they get inside the electron cloud and + + align:start position:0% +they get inside the electron cloud and + + + align:start position:0% +they get inside the electron cloud and +they turn + + align:start position:0% +they turn + + + align:start position:0% +they turn +and that's when they give off this + + align:start position:0% +and that's when they give off this + + + align:start position:0% +and that's when they give off this +continuous radiation + + align:start position:0% +continuous radiation + + + align:start position:0% +continuous radiation +right but but but we also know that + + align:start position:0% +right but but but we also know that + + + align:start position:0% +right but but but we also know that +there's a limit here + + align:start position:0% +there's a limit here + + + align:start position:0% +there's a limit here +we right remember that we talked about + + align:start position:0% +we right remember that we talked about + + + align:start position:0% +we right remember that we talked about +that and that this limit + + align:start position:0% +that and that this limit + + + align:start position:0% +that and that this limit +limit is set by + + align:start position:0% + + + + align:start position:0% + +this maximum + + align:start position:0% +this maximum + + + align:start position:0% +this maximum +this it's just the the maximum that you + + align:start position:0% +this it's just the the maximum that you + + + align:start position:0% +this it's just the the maximum that you +could + + align:start position:0% +could + + + align:start position:0% +could +the maximum amount of energy that you + + align:start position:0% +the maximum amount of energy that you + + + align:start position:0% +the maximum amount of energy that you +could get out of a photon being emitted + + align:start position:0% +could get out of a photon being emitted + + + align:start position:0% +could get out of a photon being emitted +this way + + align:start position:0% +this way + + + align:start position:0% +this way +would be equal to the incoming electron + + align:start position:0% +would be equal to the incoming electron + + + align:start position:0% +would be equal to the incoming electron +the incoming electron + + align:start position:0% +the incoming electron + + + align:start position:0% +the incoming electron +transferred all of its energy to the + + align:start position:0% +transferred all of its energy to the + + + align:start position:0% +transferred all of its energy to the +photon so that's why there's a maximum + + align:start position:0% +photon so that's why there's a maximum + + + align:start position:0% +photon so that's why there's a maximum +and and it's also why it increases + + align:start position:0% +and and it's also why it increases + + + align:start position:0% +and and it's also why it increases +remember + + align:start position:0% +remember + + + align:start position:0% +remember +right shorter wavelength higher energy + + align:start position:0% +right shorter wavelength higher energy + + + align:start position:0% +right shorter wavelength higher energy +right so it increases + + align:start position:0% +right so it increases + + + align:start position:0% +right so it increases +as you increase the energy of the + + align:start position:0% +as you increase the energy of the + + + align:start position:0% +as you increase the energy of the +incident electron + + align:start position:0% +incident electron + + + align:start position:0% +incident electron +okay that is brem strolling let's watch + + align:start position:0% +okay that is brem strolling let's watch + + + align:start position:0% +okay that is brem strolling let's watch +a video because i + + align:start position:0% +a video because i + + + align:start position:0% +a video because i +this is actually a very nicely done uh + + align:start position:0% +this is actually a very nicely done uh + + + align:start position:0% +this is actually a very nicely done uh +video that captures it with animation + + align:start position:0% + + + + align:start position:0% + +so okay so here's your crt now okay here + + align:start position:0% +so okay so here's your crt now okay here + + + align:start position:0% +so okay so here's your crt now okay here +they come + + align:start position:0% +they come + + + align:start position:0% +they come +those are those electrons in there + + align:start position:0% +those are those electrons in there + + + align:start position:0% +those are those electrons in there +voltage is high + + align:start position:0% +voltage is high + + + align:start position:0% +voltage is high +so they're coming out look at them + + align:start position:0% +so they're coming out look at them + + + align:start position:0% +so they're coming out look at them +coming out really fast right + + align:start position:0% +coming out really fast right + + + align:start position:0% +coming out really fast right +lots of kinetic energy okay + + align:start position:0% +lots of kinetic energy okay + + + align:start position:0% +lots of kinetic energy okay +and then there they go and they put and + + align:start position:0% +and then there they go and they put and + + + align:start position:0% +and then there they go and they put and +this is what rincon did he put a little + + align:start position:0% +this is what rincon did he put a little + + + align:start position:0% +this is what rincon did he put a little +piece of metal in there so now those + + align:start position:0% +piece of metal in there so now those + + + align:start position:0% +piece of metal in there so now those +electrons are hitting the metal + + align:start position:0% +electrons are hitting the metal + + + align:start position:0% +electrons are hitting the metal +okay so those are the two things that + + align:start position:0% +okay so those are the two things that + + + align:start position:0% +okay so those are the two things that +you differently remember the room lit up + + align:start position:0% +you differently remember the room lit up + + + align:start position:0% +you differently remember the room lit up +even when all the lights were off okay + + align:start position:0% +even when all the lights were off okay + + + align:start position:0% +even when all the lights were off okay +there they are + + align:start position:0% +there they are + + + align:start position:0% +there they are +nice good electrons oh and here they go + + align:start position:0% +nice good electrons oh and here they go + + + align:start position:0% +nice good electrons oh and here they go +and there's the metal atom + + align:start position:0% +and there's the metal atom + + + align:start position:0% +and there's the metal atom +okay and oh look at that now what are + + align:start position:0% +okay and oh look at that now what are + + + align:start position:0% +okay and oh look at that now what are +these + + align:start position:0% +these + + + align:start position:0% +these +those are x-rays coming off those are + + align:start position:0% +those are x-rays coming off those are + + + align:start position:0% +those are x-rays coming off those are +the electrons hitting the metal and + + align:start position:0% +the electrons hitting the metal and + + + align:start position:0% +the electrons hitting the metal and +here's the metal atom + + align:start position:0% +here's the metal atom + + + align:start position:0% +here's the metal atom +and as the electron comes in remember it + + align:start position:0% +and as the electron comes in remember it + + + align:start position:0% +and as the electron comes in remember it +sees the charge + + align:start position:0% +sees the charge + + + align:start position:0% +sees the charge +of the nucleus and it gets deflected + + align:start position:0% +of the nucleus and it gets deflected + + + align:start position:0% +of the nucleus and it gets deflected +and that deflection loses energy and + + align:start position:0% +and that deflection loses energy and + + + align:start position:0% +and that deflection loses energy and +that loss of energy goes into a photon + + align:start position:0% +that loss of energy goes into a photon + + + align:start position:0% +that loss of energy goes into a photon +now because + + align:start position:0% +now because + + + align:start position:0% +now because +these electrons have such high energy to + + align:start position:0% +these electrons have such high energy to + + + align:start position:0% +these electrons have such high energy to +start with + + align:start position:0% +start with + + + align:start position:0% +start with +because they have such high energy to + + align:start position:0% +because they have such high energy to + + + align:start position:0% +because they have such high energy to +start with um + + align:start position:0% +start with um + + + align:start position:0% +start with um +you know the energies of the photons are + + align:start position:0% +you know the energies of the photons are + + + align:start position:0% +you know the energies of the photons are +very high + + align:start position:0% +very high + + + align:start position:0% +very high +and they're x-rays right they're x-rays + + align:start position:0% +and they're x-rays right they're x-rays + + + align:start position:0% +and they're x-rays right they're x-rays +um and so okay and so here's the + + align:start position:0% +um and so okay and so here's the + + + align:start position:0% +um and so okay and so here's the +wavelength and you can see that + + align:start position:0% +wavelength and you can see that + + + align:start position:0% +wavelength and you can see that +uh well it's sort of a little hard to + + align:start position:0% +uh well it's sort of a little hard to + + + align:start position:0% +uh well it's sort of a little hard to +see in this blue range but see higher + + align:start position:0% +see in this blue range but see higher + + + align:start position:0% +see in this blue range but see higher +energy + + align:start position:0% +energy + + + align:start position:0% +energy +shorter wavelength lower energy longer + + align:start position:0% +shorter wavelength lower energy longer + + + align:start position:0% +shorter wavelength lower energy longer +wavelength very nice okay so that's the + + align:start position:0% +wavelength very nice okay so that's the + + + align:start position:0% +wavelength very nice okay so that's the +animation of brem stalling + + align:start position:0% +animation of brem stalling + + + align:start position:0% +animation of brem stalling +now okay good now the thing is what we + + align:start position:0% +now okay good now the thing is what we + + + align:start position:0% +now okay good now the thing is what we +also learned + + align:start position:0% +also learned + + + align:start position:0% +also learned +is that there's another type of x-ray + + align:start position:0% +is that there's another type of x-ray + + + align:start position:0% +is that there's another type of x-ray +there's another type of x-ray + + align:start position:0% +there's another type of x-ray + + + align:start position:0% +there's another type of x-ray +and and in fact if you crank this up + + align:start position:0% +and and in fact if you crank this up + + + align:start position:0% +and and in fact if you crank this up +high enough + + align:start position:0% +high enough + + + align:start position:0% +high enough +you get that you can get that other type + + align:start position:0% +you get that you can get that other type + + + align:start position:0% +you get that you can get that other type +so now we go higher oh + + align:start position:0% +so now we go higher oh + + + align:start position:0% +so now we go higher oh +we didn't see it here it just looks like + + align:start position:0% +we didn't see it here it just looks like + + + align:start position:0% +we didn't see it here it just looks like +that and that and that and then + + align:start position:0% +that and that and that and then + + + align:start position:0% +that and that and that and then +all of a sudden we go up to 40 kev + + align:start position:0% +all of a sudden we go up to 40 kev + + + align:start position:0% +all of a sudden we go up to 40 kev +and we see this + + align:start position:0% +and we see this + + + align:start position:0% +and we see this +why right what happened here and what + + align:start position:0% +why right what happened here and what + + + align:start position:0% +why right what happened here and what +happened here is a totally different + + align:start position:0% +happened here is a totally different + + + align:start position:0% +happened here is a totally different +mechanism for generating x-rays right + + align:start position:0% +mechanism for generating x-rays right + + + align:start position:0% +mechanism for generating x-rays right +and that was the second type that we + + align:start position:0% +and that was the second type that we + + + align:start position:0% +and that was the second type that we +talked about on friday those peaks + + align:start position:0% +talked about on friday those peaks + + + align:start position:0% +talked about on friday those peaks +are called characteristic and and the + + align:start position:0% +are called characteristic and and the + + + align:start position:0% +are called characteristic and and the +reason is + + align:start position:0% +reason is + + + align:start position:0% +reason is +that remember we have these + + align:start position:0% +that remember we have these + + + align:start position:0% +that remember we have these +levels which now that we are talking + + align:start position:0% +levels which now that we are talking + + + align:start position:0% +levels which now that we are talking +about x-rays + + align:start position:0% +about x-rays + + + align:start position:0% +about x-rays +we give them letters k l m + + align:start position:0% +we give them letters k l m + + + align:start position:0% +we give them letters k l m +n but it's just the quantum numbers n + + align:start position:0% +n but it's just the quantum numbers n + + + align:start position:0% +n but it's just the quantum numbers n +equals 1 + + align:start position:0% +equals 1 + + + align:start position:0% +equals 1 +n equals 2 right okay + + align:start position:0% +n equals 2 right okay + + + align:start position:0% +n equals 2 right okay +n equals 3 n equals 4. + + align:start position:0% +n equals 3 n equals 4. + + + align:start position:0% +n equals 3 n equals 4. +and what we said is that the way + + align:start position:0% +and what we said is that the way + + + align:start position:0% +and what we said is that the way +characteristic x-rays + + align:start position:0% +characteristic x-rays + + + align:start position:0% +characteristic x-rays +are labeled is that if an electron is + + align:start position:0% +are labeled is that if an electron is + + + align:start position:0% +are labeled is that if an electron is +excited from this gazentite + + align:start position:0% +excited from this gazentite + + + align:start position:0% +excited from this gazentite +from this lower level right if an + + align:start position:0% +from this lower level right if an + + + align:start position:0% +from this lower level right if an +electron + + align:start position:0% +electron + + + align:start position:0% +electron +is is knocked out of here then there's a + + align:start position:0% +is is knocked out of here then there's a + + + align:start position:0% +is is knocked out of here then there's a +place for an electron from here to go + + align:start position:0% +place for an electron from here to go + + + align:start position:0% +place for an electron from here to go +down + + align:start position:0% +down + + + align:start position:0% +down +maybe the electron is excited maybe the + + align:start position:0% +maybe the electron is excited maybe the + + + align:start position:0% +maybe the electron is excited maybe the +electron is kicked out + + align:start position:0% +electron is kicked out + + + align:start position:0% +electron is kicked out +and then something here can come down + + align:start position:0% +and then something here can come down + + + align:start position:0% +and then something here can come down +and when that happens + + align:start position:0% +and when that happens + + + align:start position:0% +and when that happens +just like just like + + align:start position:0% +just like just like + + + align:start position:0% +just like just like +in the bohr model you get + + align:start position:0% +in the bohr model you get + + + align:start position:0% +in the bohr model you get +radiation right but now unlike hydrogen + + align:start position:0% +radiation right but now unlike hydrogen + + + align:start position:0% +radiation right but now unlike hydrogen +13.6 electrons these are kev of energy + + align:start position:0% +13.6 electrons these are kev of energy + + + align:start position:0% +13.6 electrons these are kev of energy +these are very high energies why because + + align:start position:0% +these are very high energies why because + + + align:start position:0% +these are very high energies why because +it's the 1s electron + + align:start position:0% +it's the 1s electron + + + align:start position:0% +it's the 1s electron +and we know that once you get down to + + align:start position:0% +and we know that once you get down to + + + align:start position:0% +and we know that once you get down to +those metals right + + align:start position:0% +those metals right + + + align:start position:0% +those metals right +wait those 1s electrons you go down + + align:start position:0% +wait those 1s electrons you go down + + + align:start position:0% +wait those 1s electrons you go down +further down the periodic table those 1s + + align:start position:0% +further down the periodic table those 1s + + + align:start position:0% +further down the periodic table those 1s +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +are seriously tightly bound yeah + + align:start position:0% +are seriously tightly bound yeah + + + align:start position:0% +are seriously tightly bound yeah +and and those levels have a have a + + align:start position:0% +and and those levels have a have a + + + align:start position:0% +and and those levels have a have a +difference + + align:start position:0% +difference + + + align:start position:0% +difference +down there that is pretty high in energy + + align:start position:0% +down there that is pretty high in energy + + + align:start position:0% +down there that is pretty high in energy +it's x-ray high in energy + + align:start position:0% +it's x-ray high in energy + + + align:start position:0% +it's x-ray high in energy +that's the point so now when that + + align:start position:0% +that's the point so now when that + + + align:start position:0% +that's the point so now when that +cascade happens we call that a k + + align:start position:0% +cascade happens we call that a k + + + align:start position:0% +cascade happens we call that a k +alpha and if it were to have come from + + align:start position:0% +alpha and if it were to have come from + + + align:start position:0% +alpha and if it were to have come from +here + + align:start position:0% +here + + + align:start position:0% +here +it would be called a k beta right + + align:start position:0% + + + + align:start position:0% + +and and those are transitions that + + align:start position:0% +and and those are transitions that + + + align:start position:0% +and and those are transitions that +unlike + + align:start position:0% +unlike + + + align:start position:0% +unlike +this continuous energy those transitions + + align:start position:0% +this continuous energy those transitions + + + align:start position:0% +this continuous energy those transitions +only happen at very specific energies + + align:start position:0% +only happen at very specific energies + + + align:start position:0% +only happen at very specific energies +delta + + align:start position:0% +delta + + + align:start position:0% +delta +delta energies right the change in + + align:start position:0% +delta energies right the change in + + + align:start position:0% +delta energies right the change in +energy from + + align:start position:0% +energy from + + + align:start position:0% +energy from +l to k or or for k beta would be going + + align:start position:0% +l to k or or for k beta would be going + + + align:start position:0% +l to k or or for k beta would be going +from + + align:start position:0% +from + + + align:start position:0% +from +m to k you say it's k + + align:start position:0% +m to k you say it's k + + + align:start position:0% +m to k you say it's k +alpha k beta you use the k because + + align:start position:0% +alpha k beta you use the k because + + + align:start position:0% +alpha k beta you use the k because +that's the final place the electron + + align:start position:0% +that's the final place the electron + + + align:start position:0% +that's the final place the electron +goes when it it decays down okay + + align:start position:0% +goes when it it decays down okay + + + align:start position:0% +goes when it it decays down okay +so if you had to if i just showed you + + align:start position:0% +so if you had to if i just showed you + + + align:start position:0% +so if you had to if i just showed you +these + + align:start position:0% +these + + + align:start position:0% +these +and say well that would be like k alpha + + align:start position:0% +and say well that would be like k alpha + + + align:start position:0% +and say well that would be like k alpha +and that would be like k beta because + + align:start position:0% +and that would be like k beta because + + + align:start position:0% +and that would be like k beta because +you know + + align:start position:0% +you know + + + align:start position:0% +you know +that k beta is going to be a higher + + align:start position:0% +that k beta is going to be a higher + + + align:start position:0% +that k beta is going to be a higher +energy photon right because it came up + + align:start position:0% +energy photon right because it came up + + + align:start position:0% +energy photon right because it came up +from a higher level + + align:start position:0% +from a higher level + + + align:start position:0% +from a higher level +okay well you would also have on here + + align:start position:0% +okay well you would also have on here + + + align:start position:0% +okay well you would also have on here +some other + + align:start position:0% +some other + + + align:start position:0% +some other +peaks right you would have the l peaks + + align:start position:0% +peaks right you would have the l peaks + + + align:start position:0% +peaks right you would have the l peaks +right + + align:start position:0% +right + + + align:start position:0% +right +so you'd have like l + + align:start position:0% +so you'd have like l + + + align:start position:0% +so you'd have like l +alpha l beta + + align:start position:0% +alpha l beta + + + align:start position:0% +alpha l beta +right see so you see so so as you crank + + align:start position:0% +right see so you see so so as you crank + + + align:start position:0% +right see so you see so so as you crank +the energy up + + align:start position:0% +the energy up + + + align:start position:0% +the energy up +right then you can knock out those core + + align:start position:0% +right then you can knock out those core + + + align:start position:0% +right then you can knock out those core +electrons and these cascades happen + + align:start position:0% +electrons and these cascades happen + + + align:start position:0% +electrons and these cascades happen +and you get these discrete peaks notice + + align:start position:0% +and you get these discrete peaks notice + + + align:start position:0% +and you get these discrete peaks notice +they will only come when you have enough + + align:start position:0% +they will only come when you have enough + + + align:start position:0% +they will only come when you have enough +elect enough energy in that incident + + align:start position:0% +elect enough energy in that incident + + + align:start position:0% +elect enough energy in that incident +electron + + align:start position:0% +electron + + + align:start position:0% +electron +to knock this electron out from the core + + align:start position:0% +to knock this electron out from the core + + + align:start position:0% +to knock this electron out from the core +so that's why they don't appear until + + align:start position:0% +so that's why they don't appear until + + + align:start position:0% +so that's why they don't appear until +you get to a certain + + align:start position:0% +you get to a certain + + + align:start position:0% +you get to a certain +incident electron energy right they + + align:start position:0% +incident electron energy right they + + + align:start position:0% +incident electron energy right they +don't appear until you get to that + + align:start position:0% +don't appear until you get to that + + + align:start position:0% +don't appear until you get to that +certain energy right and so we have a + + align:start position:0% +certain energy right and so we have a + + + align:start position:0% +certain energy right and so we have a +video + + align:start position:0% +video + + + align:start position:0% +video +on that which also i will narrate + + align:start position:0% +on that which also i will narrate + + + align:start position:0% +on that which also i will narrate +but is this + + align:start position:0% +but is this + + + align:start position:0% +but is this +it there we go okay so there it is + + align:start position:0% +it there we go okay so there it is + + + align:start position:0% +it there we go okay so there it is +it's a metal atom i don't know which one + + align:start position:0% +it's a metal atom i don't know which one + + + align:start position:0% +it's a metal atom i don't know which one +um + + align:start position:0% +um + + + align:start position:0% +um +and what you're okay there's the + + align:start position:0% +and what you're okay there's the + + + align:start position:0% +and what you're okay there's the +incident electron you fired it and look + + align:start position:0% +incident electron you fired it and look + + + align:start position:0% +incident electron you fired it and look +at that + + align:start position:0% +at that + + + align:start position:0% +at that +it knocked out a core 1s electron + + align:start position:0% +it knocked out a core 1s electron + + + align:start position:0% +it knocked out a core 1s electron +because it had enough energy + + align:start position:0% +because it had enough energy + + + align:start position:0% +because it had enough energy +very high energy that's what rinkan did + + align:start position:0% +very high energy that's what rinkan did + + + align:start position:0% +very high energy that's what rinkan did +crank up the voltage + + align:start position:0% +crank up the voltage + + + align:start position:0% +crank up the voltage +higher kb and there it is a cascade down + + align:start position:0% +higher kb and there it is a cascade down + + + align:start position:0% +higher kb and there it is a cascade down +and an x-ray comes out + + align:start position:0% +and an x-ray comes out + + + align:start position:0% +and an x-ray comes out +you see that okay so so that + + align:start position:0% +you see that okay so so that + + + align:start position:0% +you see that okay so so that +uh very uh is that all oh yeah and then + + align:start position:0% +uh very uh is that all oh yeah and then + + + align:start position:0% +uh very uh is that all oh yeah and then +it's gonna draw + + align:start position:0% +it's gonna draw + + + align:start position:0% +it's gonna draw +because of those you get these + + align:start position:0% +because of those you get these + + + align:start position:0% +because of those you get these +characteristic peaks now we call them + + align:start position:0% +characteristic peaks now we call them + + + align:start position:0% +characteristic peaks now we call them +characteristic + + align:start position:0% +characteristic + + + align:start position:0% +characteristic +because now you can see why so unlike + + align:start position:0% +because now you can see why so unlike + + + align:start position:0% +because now you can see why so unlike +the continuous radiation + + align:start position:0% +the continuous radiation + + + align:start position:0% +the continuous radiation +right these peaks depend on the atom + + align:start position:0% +right these peaks depend on the atom + + + align:start position:0% +right these peaks depend on the atom +because they depend on the energy levels + + align:start position:0% +because they depend on the energy levels + + + align:start position:0% +because they depend on the energy levels +of the atom + + align:start position:0% +of the atom + + + align:start position:0% +of the atom +right and so that's why like if you look + + align:start position:0% +right and so that's why like if you look + + + align:start position:0% +right and so that's why like if you look +this up you say well okay let's look at + + align:start position:0% +this up you say well okay let's look at + + + align:start position:0% +this up you say well okay let's look at +the k + + align:start position:0% +the k + + + align:start position:0% +the k +alpha radiation let's look at the + + align:start position:0% +alpha radiation let's look at the + + + align:start position:0% +alpha radiation let's look at the +k-alpha peaks + + align:start position:0% +k-alpha peaks + + + align:start position:0% +k-alpha peaks +right that come out of of different + + align:start position:0% +right that come out of of different + + + align:start position:0% +right that come out of of different +atoms they're going to be different + + align:start position:0% +atoms they're going to be different + + + align:start position:0% +atoms they're going to be different +okay like so so you have so you have + + align:start position:0% +okay like so so you have so you have + + + align:start position:0% +okay like so so you have so you have +very sharp + + align:start position:0% +very sharp + + + align:start position:0% +very sharp +lines of of x-rays at + + align:start position:0% +lines of of x-rays at + + + align:start position:0% +lines of of x-rays at +very specific energies for copper it's 8 + + align:start position:0% +very specific energies for copper it's 8 + + + align:start position:0% +very specific energies for copper it's 8 +kv for + + align:start position:0% +kv for + + + align:start position:0% +kv for +for molybdenum it's 17.5 right silver + + align:start position:0% +for molybdenum it's 17.5 right silver + + + align:start position:0% +for molybdenum it's 17.5 right silver +tungsten + + align:start position:0% +tungsten + + + align:start position:0% +tungsten +it changes and you can see that it goes + + align:start position:0% +it changes and you can see that it goes + + + align:start position:0% +it changes and you can see that it goes +up right + + align:start position:0% +up right + + + align:start position:0% +up right +as you as that 1s electron is lower and + + align:start position:0% +as you as that 1s electron is lower and + + + align:start position:0% +as you as that 1s electron is lower and +lower in energy because i'm adding all + + align:start position:0% +lower in energy because i'm adding all + + + align:start position:0% +lower in energy because i'm adding all +these protons + + align:start position:0% +these protons + + + align:start position:0% +these protons +so it all makes sense from the concepts + + align:start position:0% +so it all makes sense from the concepts + + + align:start position:0% +so it all makes sense from the concepts +we've learned + + align:start position:0% +we've learned + + + align:start position:0% +we've learned +oh but see now now that's really useful + + align:start position:0% +oh but see now now that's really useful + + + align:start position:0% +oh but see now now that's really useful +that is really useful because now i've + + align:start position:0% +that is really useful because now i've + + + align:start position:0% +that is really useful because now i've +got a way + + align:start position:0% +got a way + + + align:start position:0% +got a way +to have a source of x-rays that is super + + align:start position:0% +to have a source of x-rays that is super + + + align:start position:0% +to have a source of x-rays that is super +well defined it's super clear it's + + align:start position:0% +well defined it's super clear it's + + + align:start position:0% +well defined it's super clear it's +always this ah that's so cool + + align:start position:0% +always this ah that's so cool + + + align:start position:0% +always this ah that's so cool +it as long as i have the same metal it's + + align:start position:0% +it as long as i have the same metal it's + + + align:start position:0% +it as long as i have the same metal it's +always the same + + align:start position:0% +always the same + + + align:start position:0% +always the same +right i can increase or decrease well i + + align:start position:0% +right i can increase or decrease well i + + + align:start position:0% +right i can increase or decrease well i +can't + + align:start position:0% +can't + + + align:start position:0% +can't +go below the threshold but i can go + + align:start position:0% +go below the threshold but i can go + + + align:start position:0% +go below the threshold but i can go +above it and that peak is + + align:start position:0% +above it and that peak is + + + align:start position:0% +above it and that peak is +characteristic of the metal + + align:start position:0% +characteristic of the metal + + + align:start position:0% +characteristic of the metal +so it doesn't change that's really + + align:start position:0% +so it doesn't change that's really + + + align:start position:0% +so it doesn't change that's really +useful + + align:start position:0% +useful + + + align:start position:0% +useful +because i've got now a flashlight i've + + align:start position:0% +because i've got now a flashlight i've + + + align:start position:0% +because i've got now a flashlight i've +got an x-ray flashlight + + align:start position:0% +got an x-ray flashlight + + + align:start position:0% +got an x-ray flashlight +where the energy that i'm sending out is + + align:start position:0% +where the energy that i'm sending out is + + + align:start position:0% +where the energy that i'm sending out is +always exactly what i know it to be + + align:start position:0% +always exactly what i know it to be + + + align:start position:0% +always exactly what i know it to be +i can predict what it is and it always + + align:start position:0% +i can predict what it is and it always + + + align:start position:0% +i can predict what it is and it always +will be that depending + + align:start position:0% +will be that depending + + + align:start position:0% +will be that depending +on which metal i put in there right so + + align:start position:0% +on which metal i put in there right so + + + align:start position:0% +on which metal i put in there right so +so that's a useful + + align:start position:0% +so that's a useful + + + align:start position:0% +so that's a useful +that's a useful thing why is that useful + + align:start position:0% +that's a useful thing why is that useful + + + align:start position:0% +that's a useful thing why is that useful +well that gets to the the topic that is + + align:start position:0% +well that gets to the the topic that is + + + align:start position:0% +well that gets to the the topic that is +the topic of today + + align:start position:0% +the topic of today + + + align:start position:0% +the topic of today +and a friday which is what are we doing + + align:start position:0% +and a friday which is what are we doing + + + align:start position:0% +and a friday which is what are we doing +with these x-rays well first we're + + align:start position:0% +with these x-rays well first we're + + + align:start position:0% +with these x-rays well first we're +generating them so that's what we've + + align:start position:0% +generating them so that's what we've + + + align:start position:0% +generating them so that's what we've +talked about so far + + align:start position:0% +talked about so far + + + align:start position:0% +talked about so far +right but now because in tight we're + + align:start position:0% +right but now because in tight we're + + + align:start position:0% +right but now because in tight we're +going to actually use them + + align:start position:0% +going to actually use them + + + align:start position:0% +going to actually use them +to determine the crystal that we have + + align:start position:0% +to determine the crystal that we have + + + align:start position:0% +to determine the crystal that we have +we're going to actually use them we're + + align:start position:0% +we're going to actually use them we're + + + align:start position:0% +we're going to actually use them we're +going to use that flashlight + + align:start position:0% +going to use that flashlight + + + align:start position:0% +going to use that flashlight +okay and and so you know so you can see + + align:start position:0% +okay and and so you know so you can see + + + align:start position:0% +okay and and so you know so you can see +why this would be useful because + + align:start position:0% +why this would be useful because + + + align:start position:0% +why this would be useful because +here is the this is the range we've + + align:start position:0% +here is the this is the range we've + + + align:start position:0% +here is the this is the range we've +showed this before + + align:start position:0% +showed this before + + + align:start position:0% +showed this before +right of x-rays so they they have these + + align:start position:0% +right of x-rays so they they have these + + + align:start position:0% +right of x-rays so they they have these +energies of kev + + align:start position:0% +energies of kev + + + align:start position:0% +energies of kev +and they have wavelengths right around a + + align:start position:0% +and they have wavelengths right around a + + + align:start position:0% +and they have wavelengths right around a +few angstroms + + align:start position:0% +few angstroms + + + align:start position:0% +few angstroms +that's a little less than an angstrom + + align:start position:0% +that's a little less than an angstrom + + + align:start position:0% +that's a little less than an angstrom +maybe two angstroms right see where + + align:start position:0% +maybe two angstroms right see where + + + align:start position:0% +maybe two angstroms right see where +those wavelengths are + + align:start position:0% +those wavelengths are + + + align:start position:0% +those wavelengths are +well those are atomic spacings + + align:start position:0% +well those are atomic spacings + + + align:start position:0% +well those are atomic spacings +those are like distances between layers + + align:start position:0% +those are like distances between layers + + + align:start position:0% +those are like distances between layers +right and so if we could shine these on + + align:start position:0% +right and so if we could shine these on + + + align:start position:0% +right and so if we could shine these on +a crystal + + align:start position:0% +a crystal + + + align:start position:0% +a crystal +and and somehow figure out what it is + + align:start position:0% +and and somehow figure out what it is + + + align:start position:0% +and and somehow figure out what it is +with that + + align:start position:0% +with that + + + align:start position:0% +with that +light oh there's a way we can do that + + align:start position:0% +light oh there's a way we can do that + + + align:start position:0% +light oh there's a way we can do that +it's called diffraction + + align:start position:0% +it's called diffraction + + + align:start position:0% +it's called diffraction +because what happens is and and we know + + align:start position:0% +because what happens is and and we know + + + align:start position:0% +because what happens is and and we know +this from + + align:start position:0% +this from + + + align:start position:0% +this from +from many fields this is you can think + + align:start position:0% +from many fields this is you can think + + + align:start position:0% +from many fields this is you can think +about this just as a water wave + + align:start position:0% +about this just as a water wave + + + align:start position:0% +about this just as a water wave +any wave okay if the wavelength + + align:start position:0% +any wave okay if the wavelength + + + align:start position:0% +any wave okay if the wavelength +is similar in size + + align:start position:0% +is similar in size + + + align:start position:0% +is similar in size +to the features then you get + + align:start position:0% +to the features then you get + + + align:start position:0% +to the features then you get +constructive and destructive + + align:start position:0% +constructive and destructive + + + align:start position:0% +constructive and destructive +interference + + align:start position:0% +interference + + + align:start position:0% +interference +as a result of the interaction between + + align:start position:0% +as a result of the interaction between + + + align:start position:0% +as a result of the interaction between +the wave and the features + + align:start position:0% +the wave and the features + + + align:start position:0% +the wave and the features +so that's called diffraction right and + + align:start position:0% +so that's called diffraction right and + + + align:start position:0% +so that's called diffraction right and +you can see it here with this very + + align:start position:0% +you can see it here with this very + + + align:start position:0% +you can see it here with this very +simple + + align:start position:0% +simple + + + align:start position:0% +simple +uh picture of say a water this could be + + align:start position:0% +uh picture of say a water this could be + + + align:start position:0% +uh picture of say a water this could be +like a water wave a sound wave + + align:start position:0% +like a water wave a sound wave + + + align:start position:0% +like a water wave a sound wave +you know and there it is and it's it's + + align:start position:0% +you know and there it is and it's it's + + + align:start position:0% +you know and there it is and it's it's +interfering + + align:start position:0% +interfering + + + align:start position:0% +interfering +uh both constructively and destructively + + align:start position:0% +uh both constructively and destructively + + + align:start position:0% +uh both constructively and destructively +along these lines + + align:start position:0% +along these lines + + + align:start position:0% +along these lines +right you can do this test yourself + + align:start position:0% +right you can do this test yourself + + + align:start position:0% +right you can do this test yourself +you could take um i highly recommend + + align:start position:0% +you could take um i highly recommend + + + align:start position:0% +you could take um i highly recommend +this take a laser pointer + + align:start position:0% +this take a laser pointer + + + align:start position:0% +this take a laser pointer +and uh now if i is there now if i just + + align:start position:0% +and uh now if i is there now if i just + + + align:start position:0% +and uh now if i is there now if i just +had a piece of metal + + align:start position:0% +had a piece of metal + + + align:start position:0% +had a piece of metal +i don't have a piece of metal but if i + + align:start position:0% +i don't have a piece of metal but if i + + + align:start position:0% +i don't have a piece of metal but if i +did + + align:start position:0% +did + + + align:start position:0% +did +then i would shine it on it and what + + align:start position:0% +then i would shine it on it and what + + + align:start position:0% +then i would shine it on it and what +you'd see is that the dot would just + + align:start position:0% +you'd see is that the dot would just + + + align:start position:0% +you'd see is that the dot would just +reflect off the piece of metal + + align:start position:0% +reflect off the piece of metal + + + align:start position:0% +reflect off the piece of metal +okay so i just would get the dot back + + align:start position:0% +okay so i just would get the dot back + + + align:start position:0% +okay so i just would get the dot back +right + + align:start position:0% +right + + + align:start position:0% +right +but now i've got this thing here this we + + align:start position:0% +but now i've got this thing here this we + + + align:start position:0% +but now i've got this thing here this we +many of you may not know what this + + align:start position:0% +many of you may not know what this + + + align:start position:0% +many of you may not know what this +is um this is called a cd + + align:start position:0% +is um this is called a cd + + + align:start position:0% +is um this is called a cd +okay and oh but it turns out that a cd + + align:start position:0% +okay and oh but it turns out that a cd + + + align:start position:0% +okay and oh but it turns out that a cd +has + + align:start position:0% +has + + + align:start position:0% +has +it has features and it's got trenches + + align:start position:0% +it has features and it's got trenches + + + align:start position:0% +it has features and it's got trenches +that are like + + align:start position:0% +that are like + + + align:start position:0% +that are like +you know a little less than a micron + + align:start position:0% +you know a little less than a micron + + + align:start position:0% +you know a little less than a micron +apart 800 nanometers + + align:start position:0% +apart 800 nanometers + + + align:start position:0% +apart 800 nanometers +and this is 500 nanometer light so you + + align:start position:0% +and this is 500 nanometer light so you + + + align:start position:0% +and this is 500 nanometer light so you +would expect there to be diffraction + + align:start position:0% +would expect there to be diffraction + + + align:start position:0% +would expect there to be diffraction +you would expect there to be + + align:start position:0% +you would expect there to be + + + align:start position:0% +you would expect there to be +constructive and destructive + + align:start position:0% +constructive and destructive + + + align:start position:0% +constructive and destructive +interference and when i + + align:start position:0% +interference and when i + + + align:start position:0% +interference and when i +bounce it off of this look at that there + + align:start position:0% +bounce it off of this look at that there + + + align:start position:0% +bounce it off of this look at that there +it is + + align:start position:0% +it is + + + align:start position:0% +it is +this never gets old i'm not getting + + align:start position:0% +this never gets old i'm not getting + + + align:start position:0% +this never gets old i'm not getting +i'm not getting just one reflection + + align:start position:0% +i'm not getting just one reflection + + + align:start position:0% +i'm not getting just one reflection +here i'm getting a whole scatter of them + + align:start position:0% +here i'm getting a whole scatter of them + + + align:start position:0% +here i'm getting a whole scatter of them +that have + + align:start position:0% +that have + + + align:start position:0% +that have +constructively interfered because of the + + align:start position:0% +constructively interfered because of the + + + align:start position:0% +constructively interfered because of the +feature sizes being + + align:start position:0% +feature sizes being + + + align:start position:0% +feature sizes being +the same as the as the wavelength + + align:start position:0% +the same as the as the wavelength + + + align:start position:0% +the same as the as the wavelength +okay but now i want to do that with + + align:start position:0% +okay but now i want to do that with + + + align:start position:0% +okay but now i want to do that with +x-rays and i want to do it + + align:start position:0% +x-rays and i want to do it + + + align:start position:0% +x-rays and i want to do it +onto onto crystals so how do we do that + + align:start position:0% +onto onto crystals so how do we do that + + + align:start position:0% +onto onto crystals so how do we do that +okay so let's think about that and we're + + align:start position:0% +okay so let's think about that and we're + + + align:start position:0% +okay so let's think about that and we're +going to think about it in terms of what + + align:start position:0% +going to think about it in terms of what + + + align:start position:0% +going to think about it in terms of what +the bragg father-son pair + + align:start position:0% +the bragg father-son pair + + + align:start position:0% +the bragg father-son pair +who won the nobel prize and are on a + + align:start position:0% +who won the nobel prize and are on a + + + align:start position:0% +who won the nobel prize and are on a +stamp that's what you get uh + + align:start position:0% +stamp that's what you get uh + + + align:start position:0% +stamp that's what you get uh +when you win a nobel prize i guess um + + align:start position:0% +when you win a nobel prize i guess um + + + align:start position:0% +when you win a nobel prize i guess um +and um + + align:start position:0% +and um + + + align:start position:0% +and um +and what they did is they figured out + + align:start position:0% +and what they did is they figured out + + + align:start position:0% +and what they did is they figured out +how to do this okay + + align:start position:0% +how to do this okay + + + align:start position:0% +how to do this okay +so let's let's go through that just so + + align:start position:0% +so let's let's go through that just so + + + align:start position:0% +so let's let's go through that just so +we understand it conceptually + + align:start position:0% +we understand it conceptually + + + align:start position:0% +we understand it conceptually +um okay so + + align:start position:0% +um okay so + + + align:start position:0% +um okay so +if i have i'm going to say that i have a + + align:start position:0% +if i have i'm going to say that i have a + + + align:start position:0% +if i have i'm going to say that i have a +set + + align:start position:0% +set + + + align:start position:0% +set +of atoms now right now i'm not going to + + align:start position:0% +of atoms now right now i'm not going to + + + align:start position:0% +of atoms now right now i'm not going to +worry about + + align:start position:0% +worry about + + + align:start position:0% +worry about +what they are um + + align:start position:0% +what they are um + + + align:start position:0% +what they are um +but i'm just going to say that there's + + align:start position:0% +but i'm just going to say that there's + + + align:start position:0% +but i'm just going to say that there's +some plane of atoms here + + align:start position:0% +some plane of atoms here + + + align:start position:0% +some plane of atoms here +and there's another plane of atoms + + align:start position:0% +and there's another plane of atoms + + + align:start position:0% +and there's another plane of atoms +beneath that + + align:start position:0% +beneath that + + + align:start position:0% +beneath that +okay so there's another one and + + align:start position:0% +okay so there's another one and + + + align:start position:0% +okay so there's another one and +so on and so on and now these + + align:start position:0% +so on and so on and now these + + + align:start position:0% +so on and so on and now these +these would be miller planes right these + + align:start position:0% +these would be miller planes right these + + + align:start position:0% +these would be miller planes right these +would be miller planes in the crystal + + align:start position:0% +would be miller planes in the crystal + + + align:start position:0% +would be miller planes in the crystal +and let's just assume they're very very + + align:start position:0% +and let's just assume they're very very + + + align:start position:0% +and let's just assume they're very very +simple this plane in that plane + + align:start position:0% +simple this plane in that plane + + + align:start position:0% +simple this plane in that plane +and now what i'm going to do is i'm + + align:start position:0% +and now what i'm going to do is i'm + + + align:start position:0% +and now what i'm going to do is i'm +going to have some x-rays i'm going to + + align:start position:0% +going to have some x-rays i'm going to + + + align:start position:0% +going to have some x-rays i'm going to +have some light + + align:start position:0% +have some light + + + align:start position:0% +have some light +shining on this and it's going to be + + align:start position:0% +shining on this and it's going to be + + + align:start position:0% +shining on this and it's going to be +incident + + align:start position:0% +incident + + + align:start position:0% +incident +and it's going to be reflected but see + + align:start position:0% +and it's going to be reflected but see + + + align:start position:0% +and it's going to be reflected but see +i'm going to have another wave here + + align:start position:0% + + + + align:start position:0% + +okay let's see if i can get through this + + align:start position:0% +okay let's see if i can get through this + + + align:start position:0% +okay let's see if i can get through this +drawing + + align:start position:0% +drawing + + + align:start position:0% +drawing +sort of almost kind of um + + align:start position:0% +sort of almost kind of um + + + align:start position:0% +sort of almost kind of um +now here's the deal okay + + align:start position:0% +now here's the deal okay + + + align:start position:0% +now here's the deal okay +these are waves right these are waves so + + align:start position:0% +these are waves right these are waves so + + + align:start position:0% +these are waves right these are waves so +if i had if if i want to draw this as a + + align:start position:0% +if i had if if i want to draw this as a + + + align:start position:0% +if i had if if i want to draw this as a +wave + + align:start position:0% +wave + + + align:start position:0% +wave +i might draw it like that and if these + + align:start position:0% +i might draw it like that and if these + + + align:start position:0% +i might draw it like that and if these +are if these waves + + align:start position:0% +are if these waves + + + align:start position:0% +are if these waves +are constructively interfering + + align:start position:0% +are constructively interfering + + + align:start position:0% +are constructively interfering +let's just complete that then this wave + + align:start position:0% +let's just complete that then this wave + + + align:start position:0% +let's just complete that then this wave +would look + + align:start position:0% +would look + + + align:start position:0% +would look +like that right if they're the same if + + align:start position:0% +like that right if they're the same if + + + align:start position:0% +like that right if they're the same if +they're in phase then that's what they + + align:start position:0% +they're in phase then that's what they + + + align:start position:0% +they're in phase then that's what they +would look like + + align:start position:0% +would look like + + + align:start position:0% +would look like +now this one's getting reflected off the + + align:start position:0% +now this one's getting reflected off the + + + align:start position:0% +now this one's getting reflected off the +surface right so i'm going to do that + + align:start position:0% +surface right so i'm going to do that + + + align:start position:0% +surface right so i'm going to do that +reflection here + + align:start position:0% +reflection here + + + align:start position:0% +reflection here +okay and if i want it to come back + + align:start position:0% +okay and if i want it to come back + + + align:start position:0% +okay and if i want it to come back +off of the surface and i want and this + + align:start position:0% +off of the surface and i want and this + + + align:start position:0% +off of the surface and i want and this +one + + align:start position:0% +one + + + align:start position:0% +one +got through the first layer this didn't + + align:start position:0% +got through the first layer this didn't + + + align:start position:0% +got through the first layer this didn't +get reflected it's going down + + align:start position:0% +get reflected it's going down + + + align:start position:0% +get reflected it's going down +and if i want it to come back up then + + align:start position:0% +and if i want it to come back up then + + + align:start position:0% +and if i want it to come back up then +this one must also look like that + + align:start position:0% +this one must also look like that + + + align:start position:0% +this one must also look like that +to be in phase right they must be in + + align:start position:0% +to be in phase right they must be in + + + align:start position:0% +to be in phase right they must be in +phases as they come out + + align:start position:0% +phases as they come out + + + align:start position:0% +phases as they come out +or else they're not going to interfere + + align:start position:0% +or else they're not going to interfere + + + align:start position:0% +or else they're not going to interfere +constructively you see that + + align:start position:0% +constructively you see that + + + align:start position:0% +constructively you see that +so those are my x-rays right they're + + align:start position:0% +so those are my x-rays right they're + + + align:start position:0% +so those are my x-rays right they're +waves they're just waves + + align:start position:0% +waves they're just waves + + + align:start position:0% +waves they're just waves +right oh but this is the this is the + + align:start position:0% +right oh but this is the this is the + + + align:start position:0% +right oh but this is the this is the +whole secret + + align:start position:0% +whole secret + + + align:start position:0% +whole secret +right because you know if if this is + + align:start position:0% +right because you know if if this is + + + align:start position:0% +right because you know if if this is +if this angle here is theta + + align:start position:0% +if this angle here is theta + + + align:start position:0% +if this angle here is theta +then what that means is that this angle + + align:start position:0% +then what that means is that this angle + + + align:start position:0% +then what that means is that this angle +is theta + + align:start position:0% +is theta + + + align:start position:0% +is theta +okay well yeah and if that's true + + align:start position:0% +okay well yeah and if that's true + + + align:start position:0% +okay well yeah and if that's true +then this distance is d + + align:start position:0% +then this distance is d + + + align:start position:0% +then this distance is d +sine theta where this is d + + align:start position:0% +sine theta where this is d + + + align:start position:0% +sine theta where this is d +that's just some some simple geometry + + align:start position:0% +that's just some some simple geometry + + + align:start position:0% +that's just some some simple geometry +okay so so what you know then is + + align:start position:0% +okay so so what you know then is + + + align:start position:0% +okay so so what you know then is +okay now now we're getting somewhere + + align:start position:0% +okay now now we're getting somewhere + + + align:start position:0% +okay now now we're getting somewhere +right now we're getting somewhere + + align:start position:0% +right now we're getting somewhere + + + align:start position:0% +right now we're getting somewhere +because you know + + align:start position:0% +because you know + + + align:start position:0% +because you know +if i had a wave this is one wavelength + + align:start position:0% +if i had a wave this is one wavelength + + + align:start position:0% +if i had a wave this is one wavelength +right + + align:start position:0% +right + + + align:start position:0% +right +and so so if i had a wave um + + align:start position:0% +and so so if i had a wave um + + + align:start position:0% +and so so if i had a wave um +come in like this and and one of them is + + align:start position:0% +come in like this and and one of them is + + + align:start position:0% +come in like this and and one of them is +going to get reflected off of this lower + + align:start position:0% +going to get reflected off of this lower + + + align:start position:0% +going to get reflected off of this lower +surface + + align:start position:0% +surface + + + align:start position:0% +surface +and the other one got reflected off this + + align:start position:0% +and the other one got reflected off this + + + align:start position:0% +and the other one got reflected off this +but i don't want them to interfere in + + align:start position:0% +but i don't want them to interfere in + + + align:start position:0% +but i don't want them to interfere in +any way but constructively + + align:start position:0% +any way but constructively + + + align:start position:0% +any way but constructively +that's what that's what bragg said + + align:start position:0% +that's what that's what bragg said + + + align:start position:0% +that's what that's what bragg said +bragging brag + + align:start position:0% +bragging brag + + + align:start position:0% +bragging brag +that's what they said then the only way + + align:start position:0% +that's what they said then the only way + + + align:start position:0% +that's what they said then the only way +for that to happen + + align:start position:0% +for that to happen + + + align:start position:0% +for that to happen +is if this distance plus that distance + + align:start position:0% +is if this distance plus that distance + + + align:start position:0% +is if this distance plus that distance +so + + align:start position:0% +so + + + align:start position:0% +so +d sine theta plus d sine theta is equal + + align:start position:0% +d sine theta plus d sine theta is equal + + + align:start position:0% +d sine theta plus d sine theta is equal +to + + align:start position:0% +to + + + align:start position:0% +to +some multiple of the wavelength it has + + align:start position:0% +some multiple of the wavelength it has + + + align:start position:0% +some multiple of the wavelength it has +to be + + align:start position:0% +to be + + + align:start position:0% +to be +right and so what you get is + + align:start position:0% +right and so what you get is + + + align:start position:0% +right and so what you get is +well that's what they have there n + + align:start position:0% +well that's what they have there n + + + align:start position:0% +well that's what they have there n +lambda some multiple of the wavelength + + align:start position:0% +lambda some multiple of the wavelength + + + align:start position:0% +lambda some multiple of the wavelength +equals 2d + + align:start position:0% +equals 2d + + + align:start position:0% +equals 2d +sine theta where theta is + + align:start position:0% +sine theta where theta is + + + align:start position:0% +sine theta where theta is +the incident angle of that x-ray + + align:start position:0% +the incident angle of that x-ray + + + align:start position:0% +the incident angle of that x-ray +okay so this is incident just to be + + align:start position:0% +okay so this is incident just to be + + + align:start position:0% +okay so this is incident just to be +clear + + align:start position:0% +clear + + + align:start position:0% +clear +incident x-ray + + align:start position:0% +incident x-ray + + + align:start position:0% +incident x-ray +and these are reflected + + align:start position:0% +and these are reflected + + + align:start position:0% +and these are reflected +reflected x-rays + + align:start position:0% +reflected x-rays + + + align:start position:0% +reflected x-rays +okay now to keep it simple in this class + + align:start position:0% +okay now to keep it simple in this class + + + align:start position:0% +okay now to keep it simple in this class +we're just going to + + align:start position:0% +we're just going to + + + align:start position:0% +we're just going to +say n equals 1. n equals 1 + + align:start position:0% +say n equals 1. n equals 1 + + + align:start position:0% +say n equals 1. n equals 1 +for 3091 just to keep things + + align:start position:0% +for 3091 just to keep things + + + align:start position:0% +for 3091 just to keep things +simple because we're really just i want + + align:start position:0% +simple because we're really just i want + + + align:start position:0% +simple because we're really just i want +to grasp the basic concepts here + + align:start position:0% +to grasp the basic concepts here + + + align:start position:0% +to grasp the basic concepts here +all right we're not using x-rays to get + + align:start position:0% +all right we're not using x-rays to get + + + align:start position:0% +all right we're not using x-rays to get +the the structure of dna but we're going + + align:start position:0% +the the structure of dna but we're going + + + align:start position:0% +the the structure of dna but we're going +to use x-rays to figure out cubic + + align:start position:0% +to use x-rays to figure out cubic + + + align:start position:0% +to use x-rays to figure out cubic +crystal structures we're going to show + + align:start position:0% +crystal structures we're going to show + + + align:start position:0% +crystal structures we're going to show +how that works + + align:start position:0% +how that works + + + align:start position:0% +how that works +now so this + + align:start position:0% +now so this + + + align:start position:0% +now so this +must be true for so this is in + + align:start position:0% +must be true for so this is in + + + align:start position:0% +must be true for so this is in +parentheses + + align:start position:0% +parentheses + + + align:start position:0% +parentheses +four construction interference + + align:start position:0% +four construction interference + + + align:start position:0% +four construction interference +constructive + + align:start position:0% + + + + align:start position:0% + +interference those dots that you saw + + align:start position:0% +interference those dots that you saw + + + align:start position:0% +interference those dots that you saw +interface interface no + + align:start position:0% +interface interface no + + + align:start position:0% +interface interface no +interference interference + + align:start position:0% +interference interference + + + align:start position:0% +interference interference +right for this is true + + align:start position:0% +right for this is true + + + align:start position:0% +right for this is true +for constructive interference of course + + align:start position:0% +for constructive interference of course + + + align:start position:0% +for constructive interference of course +you could write any equation you want + + align:start position:0% +you could write any equation you want + + + align:start position:0% +you could write any equation you want +but if you want them to be + + align:start position:0% +but if you want them to be + + + align:start position:0% +but if you want them to be +constructively + + align:start position:0% +constructively + + + align:start position:0% +constructively +interfering when they come out that has + + align:start position:0% +interfering when they come out that has + + + align:start position:0% +interfering when they come out that has +to be true and that's what the bragg + + align:start position:0% +to be true and that's what the bragg + + + align:start position:0% +to be true and that's what the bragg +said but see that we're not there yet + + align:start position:0% +said but see that we're not there yet + + + align:start position:0% +said but see that we're not there yet +right because now we got to do + + align:start position:0% +right because now we got to do + + + align:start position:0% +right because now we got to do +experiments + + align:start position:0% +experiments + + + align:start position:0% +experiments +okay so we got to do experiments so how + + align:start position:0% +okay so we got to do experiments so how + + + align:start position:0% +okay so we got to do experiments so how +so what does this mean well + + align:start position:0% +so what does this mean well + + + align:start position:0% +so what does this mean well +okay i'm going to + + align:start position:0% +okay i'm going to + + + align:start position:0% +okay i'm going to +i'm going to take x-rays of some lambda + + align:start position:0% +i'm going to take x-rays of some lambda + + + align:start position:0% +i'm going to take x-rays of some lambda +okay and i'm going to shine them on a + + align:start position:0% +okay and i'm going to shine them on a + + + align:start position:0% +okay and i'm going to shine them on a +sample + + align:start position:0% +sample + + + align:start position:0% +sample +right okay and i'm going to measure so + + align:start position:0% +right okay and i'm going to measure so + + + align:start position:0% +right okay and i'm going to measure so +what i'm going to do + + align:start position:0% +what i'm going to do + + + align:start position:0% +what i'm going to do +oh i think i have a picture i'm going to + + align:start position:0% +oh i think i have a picture i'm going to + + + align:start position:0% +oh i think i have a picture i'm going to +measure there it is + + align:start position:0% +measure there it is + + + align:start position:0% +measure there it is +this is what an x-ray diffraction + + align:start position:0% +this is what an x-ray diffraction + + + align:start position:0% +this is what an x-ray diffraction +experiment looks like + + align:start position:0% +experiment looks like + + + align:start position:0% +experiment looks like +okay so i've got some sample and i shine + + align:start position:0% +okay so i've got some sample and i shine + + + align:start position:0% +okay so i've got some sample and i shine +x-rays i've got a source of x-rays we + + align:start position:0% +x-rays i've got a source of x-rays we + + + align:start position:0% +x-rays i've got a source of x-rays we +now know + + align:start position:0% +now know + + + align:start position:0% +now know +how to make that source right and we'll + + align:start position:0% +how to make that source right and we'll + + + align:start position:0% +how to make that source right and we'll +just filter out + + align:start position:0% +just filter out + + + align:start position:0% +just filter out +one of these lines right okay so i've + + align:start position:0% +one of these lines right okay so i've + + + align:start position:0% +one of these lines right okay so i've +got that source and i can change + + align:start position:0% +got that source and i can change + + + align:start position:0% +got that source and i can change +the angle and then i've got a detector + + align:start position:0% +the angle and then i've got a detector + + + align:start position:0% +the angle and then i've got a detector +and and i can measure did i get + + align:start position:0% +and and i can measure did i get + + + align:start position:0% +and and i can measure did i get +interference or not it's just like the + + align:start position:0% +interference or not it's just like the + + + align:start position:0% +interference or not it's just like the +dots + + align:start position:0% +dots + + + align:start position:0% +dots +right so so now we know that if i if i + + align:start position:0% +right so so now we know that if i if i + + + align:start position:0% +right so so now we know that if i if i +do that + + align:start position:0% +do that + + + align:start position:0% +do that +and and i and i say i i scan + + align:start position:0% +and and i and i say i i scan + + + align:start position:0% +and and i and i say i i scan +the um you know i scan the end okay so + + align:start position:0% +the um you know i scan the end okay so + + + align:start position:0% +the um you know i scan the end okay so +i've got intensity + + align:start position:0% +i've got intensity + + + align:start position:0% +i've got intensity +and now i'm plotting it with angle + + align:start position:0% +and now i'm plotting it with angle + + + align:start position:0% +and now i'm plotting it with angle +so so now i'm moving this intensity + + align:start position:0% +so so now i'm moving this intensity + + + align:start position:0% +so so now i'm moving this intensity +i'm moving the angle around and i'm + + align:start position:0% +i'm moving the angle around and i'm + + + align:start position:0% +i'm moving the angle around and i'm +changing it bam i get interference and i + + align:start position:0% +changing it bam i get interference and i + + + align:start position:0% +changing it bam i get interference and i +see a spot + + align:start position:0% +see a spot + + + align:start position:0% +see a spot +in my detector so literally it would + + align:start position:0% +in my detector so literally it would + + + align:start position:0% +in my detector so literally it would +look like this + + align:start position:0% +look like this + + + align:start position:0% +look like this +right you would get some angle where + + align:start position:0% +right you would get some angle where + + + align:start position:0% +right you would get some angle where +there's interference and the detector + + align:start position:0% +there's interference and the detector + + + align:start position:0% +there's interference and the detector +will say ding ding ding ding ding i see + + align:start position:0% +will say ding ding ding ding ding i see + + + align:start position:0% +will say ding ding ding ding ding i see +a lot of + + align:start position:0% +a lot of + + + align:start position:0% +a lot of +x-rays coming off when i didn't and now + + align:start position:0% +x-rays coming off when i didn't and now + + + align:start position:0% +x-rays coming off when i didn't and now +you change the angle by a few degrees + + align:start position:0% +you change the angle by a few degrees + + + align:start position:0% +you change the angle by a few degrees +and i don't see anything + + align:start position:0% +and i don't see anything + + + align:start position:0% +and i don't see anything +right because it's all destructive from + + align:start position:0% +right because it's all destructive from + + + align:start position:0% +right because it's all destructive from +these crystal planes + + align:start position:0% +these crystal planes + + + align:start position:0% +these crystal planes +okay okay so it seems like then if i + + align:start position:0% +okay okay so it seems like then if i + + + align:start position:0% +okay okay so it seems like then if i +just vary theta + + align:start position:0% +just vary theta + + + align:start position:0% +just vary theta +um am i there yet the problem is + + align:start position:0% +um am i there yet the problem is + + + align:start position:0% +um am i there yet the problem is +that i might not know d i might not know + + align:start position:0% +that i might not know d i might not know + + + align:start position:0% +that i might not know d i might not know +d + + align:start position:0% +d + + + align:start position:0% +d +ah ha but we do know d + + align:start position:0% +ah ha but we do know d + + + align:start position:0% +ah ha but we do know d +we do know d because we learned about d + + align:start position:0% +we do know d because we learned about d + + + align:start position:0% +we do know d because we learned about d +for cubic crystals we know d + + align:start position:0% +for cubic crystals we know d + + + align:start position:0% +for cubic crystals we know d +because because for cubic systems we + + align:start position:0% +because because for cubic systems we + + + align:start position:0% +because because for cubic systems we +know + + align:start position:0% +know + + + align:start position:0% +know +that d of h k l right + + align:start position:0% +that d of h k l right + + + align:start position:0% +that d of h k l right +of any plane the distance between those + + align:start position:0% +of any plane the distance between those + + + align:start position:0% +of any plane the distance between those +planes is equal to + + align:start position:0% +planes is equal to + + + align:start position:0% +planes is equal to +a over the square root of h squared + + align:start position:0% +a over the square root of h squared + + + align:start position:0% +a over the square root of h squared +plus k squared plus l squared and that's + + align:start position:0% +plus k squared plus l squared and that's + + + align:start position:0% +plus k squared plus l squared and that's +something that + + align:start position:0% +something that + + + align:start position:0% +something that +we learned this is distance + + align:start position:0% +we learned this is distance + + + align:start position:0% +we learned this is distance +between miller planes + + align:start position:0% + + + + align:start position:0% + +miller planes because then tight in + + align:start position:0% +miller planes because then tight in + + + align:start position:0% +miller planes because then tight in +a cubic crystal + + align:start position:0% +a cubic crystal + + + align:start position:0% +a cubic crystal +oh i'm saving time i wrote excel + + align:start position:0% +oh i'm saving time i wrote excel + + + align:start position:0% +oh i'm saving time i wrote excel +i saved a lot of time which i just + + align:start position:0% +i saved a lot of time which i just + + + align:start position:0% +i saved a lot of time which i just +wasted by being so proud of it + + align:start position:0% +wasted by being so proud of it + + + align:start position:0% +wasted by being so proud of it +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +i know d well okay so what does that + + align:start position:0% +i know d well okay so what does that + + + align:start position:0% +i know d well okay so what does that +mean well + + align:start position:0% +mean well + + + align:start position:0% +mean well +let's take a look because now i'm going + + align:start position:0% +let's take a look because now i'm going + + + align:start position:0% +let's take a look because now i'm going +to go back + + align:start position:0% +to go back + + + align:start position:0% +to go back +i'm going to go back to my equation + + align:start position:0% +i'm going to go back to my equation + + + align:start position:0% +i'm going to go back to my equation +and i'm going to say okay lambda equals + + align:start position:0% +and i'm going to say okay lambda equals + + + align:start position:0% +and i'm going to say okay lambda equals +2d and i'm saying n equals one okay and + + align:start position:0% +2d and i'm saying n equals one okay and + + + align:start position:0% +2d and i'm saying n equals one okay and +i'm going to be very specific this is + + align:start position:0% +i'm going to be very specific this is + + + align:start position:0% +i'm going to be very specific this is +now + + align:start position:0% +now + + + align:start position:0% +now +a d that comes from the spacing between + + align:start position:0% +a d that comes from the spacing between + + + align:start position:0% +a d that comes from the spacing between +planes that are specified by the miller + + align:start position:0% +planes that are specified by the miller + + + align:start position:0% +planes that are specified by the miller +indices + + align:start position:0% +indices + + + align:start position:0% +indices +right times the sine of theta + + align:start position:0% +right times the sine of theta + + + align:start position:0% +right times the sine of theta +right and i'm putting h k l on the theta + + align:start position:0% +right and i'm putting h k l on the theta + + + align:start position:0% +right and i'm putting h k l on the theta +as well and you'll see why + + align:start position:0% +as well and you'll see why + + + align:start position:0% +as well and you'll see why +because here's the thing now + + align:start position:0% +because here's the thing now + + + align:start position:0% +because here's the thing now +i've got constants now i've got + + align:start position:0% +i've got constants now i've got + + + align:start position:0% +i've got constants now i've got +constants because look + + align:start position:0% +constants because look + + + align:start position:0% +constants because look +this is fixed + + align:start position:0% +this is fixed + + + align:start position:0% +this is fixed +by the source by the source so this is a + + align:start position:0% +by the source by the source so this is a + + + align:start position:0% +by the source by the source so this is a +constant + + align:start position:0% +constant + + + align:start position:0% +constant +you know if if i have copper then it's + + align:start position:0% +you know if if i have copper then it's + + + align:start position:0% +you know if if i have copper then it's +1.54 angstroms + + align:start position:0% +1.54 angstroms + + + align:start position:0% +1.54 angstroms +right this is a constant this is fixed + + align:start position:0% +right this is a constant this is fixed + + + align:start position:0% +right this is a constant this is fixed +by the crystal + + align:start position:0% +by the crystal + + + align:start position:0% +by the crystal +that's also a constant fixed + + align:start position:0% +that's also a constant fixed + + + align:start position:0% +that's also a constant fixed +by the crystal + + align:start position:0% + + + + align:start position:0% + +because that's also a constant because + + align:start position:0% +because that's also a constant because + + + align:start position:0% +because that's also a constant because +it's the lattice constant right we're + + align:start position:0% +it's the lattice constant right we're + + + align:start position:0% +it's the lattice constant right we're +not changing that + + align:start position:0% +not changing that + + + align:start position:0% +not changing that +so for a given set of planes that these + + align:start position:0% +so for a given set of planes that these + + + align:start position:0% +so for a given set of planes that these +that these waves are bouncing off of and + + align:start position:0% +that these waves are bouncing off of and + + + align:start position:0% +that these waves are bouncing off of and +and maybe maybe constructively + + align:start position:0% +and maybe maybe constructively + + + align:start position:0% +and maybe maybe constructively +interfering with + + align:start position:0% +interfering with + + + align:start position:0% +interfering with +right that depending on the theta + + align:start position:0% +right that depending on the theta + + + align:start position:0% +right that depending on the theta +then then these are constants right + + align:start position:0% +then then these are constants right + + + align:start position:0% +then then these are constants right +okay so so if i regroup them so i'm + + align:start position:0% +okay so so if i regroup them so i'm + + + align:start position:0% +okay so so if i regroup them so i'm +going to regroup them + + align:start position:0% +going to regroup them + + + align:start position:0% +going to regroup them +right and so i'm going to say that + + align:start position:0% +right and so i'm going to say that + + + align:start position:0% +right and so i'm going to say that +let's see d so i'm going to substitute + + align:start position:0% +let's see d so i'm going to substitute + + + align:start position:0% +let's see d so i'm going to substitute +in that expression up there down here + + align:start position:0% +in that expression up there down here + + + align:start position:0% +in that expression up there down here +okay and i'm going to use a copper + + align:start position:0% +okay and i'm going to use a copper + + + align:start position:0% +okay and i'm going to use a copper +source right so i'm going to say well + + align:start position:0% +source right so i'm going to say well + + + align:start position:0% +source right so i'm going to say well +let me let me go through this one step + + align:start position:0% +let me let me go through this one step + + + align:start position:0% +let me let me go through this one step +at a time so d + + align:start position:0% +at a time so d + + + align:start position:0% +at a time so d +equals 1.54 + + align:start position:0% +equals 1.54 + + + align:start position:0% +equals 1.54 +over + + align:start position:0% + + + + align:start position:0% + +let's see 2 sine + + align:start position:0% +let's see 2 sine + + + align:start position:0% +let's see 2 sine +theta h k l now what have i done here + + align:start position:0% +theta h k l now what have i done here + + + align:start position:0% +theta h k l now what have i done here +this is for a copper source so i'm i'm + + align:start position:0% +this is for a copper source so i'm i'm + + + align:start position:0% +this is for a copper source so i'm i'm +now adding in + + align:start position:0% +now adding in + + + align:start position:0% +now adding in +i'm fixing in the constant okay fixing + + align:start position:0% +i'm fixing in the constant okay fixing + + + align:start position:0% +i'm fixing in the constant okay fixing +in the constant + + align:start position:0% +in the constant + + + align:start position:0% +in the constant +okay so that's the brad condition but i + + align:start position:0% +okay so that's the brad condition but i + + + align:start position:0% +okay so that's the brad condition but i +also know + + align:start position:0% +also know + + + align:start position:0% +also know +that d is equal to + + align:start position:0% +that d is equal to + + + align:start position:0% +that d is equal to +it's also equal to ah i don't want to + + align:start position:0% +it's also equal to ah i don't want to + + + align:start position:0% +it's also equal to ah i don't want to +write it again + + align:start position:0% +write it again + + + align:start position:0% +write it again +it's also equal to that okay + + align:start position:0% +it's also equal to that okay + + + align:start position:0% +it's also equal to that okay +good okay so let's put that together + + align:start position:0% +good okay so let's put that together + + + align:start position:0% +good okay so let's put that together +we'll do a little division + + align:start position:0% +we'll do a little division + + + align:start position:0% +we'll do a little division +and what we get is 1.54 angstroms + + align:start position:0% +and what we get is 1.54 angstroms + + + align:start position:0% +and what we get is 1.54 angstroms +over 2 a squared + + align:start position:0% +over 2 a squared + + + align:start position:0% +over 2 a squared +the whole thing's squared i'm squaring + + align:start position:0% +the whole thing's squared i'm squaring + + + align:start position:0% +the whole thing's squared i'm squaring +it i don't want the square root + + align:start position:0% +it i don't want the square root + + + align:start position:0% +it i don't want the square root +equals sine squared theta + + align:start position:0% +equals sine squared theta + + + align:start position:0% +equals sine squared theta +h k l over h + + align:start position:0% +h k l over h + + + align:start position:0% +h k l over h +squared plus k squared plus l squared + + align:start position:0% +squared plus k squared plus l squared + + + align:start position:0% +squared plus k squared plus l squared +four let's be very specific for + + align:start position:0% +four let's be very specific for + + + align:start position:0% +four let's be very specific for +constructive interference + + align:start position:0% +constructive interference + + + align:start position:0% +constructive interference +okay constructive + + align:start position:0% +okay constructive + + + align:start position:0% +okay constructive +interference + + align:start position:0% + + + + align:start position:0% + +and a copper source so now i'm getting + + align:start position:0% +and a copper source so now i'm getting + + + align:start position:0% +and a copper source so now i'm getting +specific because this is how experiments + + align:start position:0% +specific because this is how experiments + + + align:start position:0% +specific because this is how experiments +with x-ray diffraction are done right + + align:start position:0% +with x-ray diffraction are done right + + + align:start position:0% +with x-ray diffraction are done right +so but now the last time i checked right + + align:start position:0% +so but now the last time i checked right + + + align:start position:0% +so but now the last time i checked right +if you got something equal to a constant + + align:start position:0% +if you got something equal to a constant + + + align:start position:0% +if you got something equal to a constant +then that something also is a constant + + align:start position:0% +then that something also is a constant + + + align:start position:0% +then that something also is a constant +right and and this + + align:start position:0% +right and and this + + + align:start position:0% +right and and this +is a constant yeah and and so so + + align:start position:0% +is a constant yeah and and so so + + + align:start position:0% +is a constant yeah and and so so +what i need to do now is figure out + + align:start position:0% +what i need to do now is figure out + + + align:start position:0% +what i need to do now is figure out +right i'm going to measure + + align:start position:0% +right i'm going to measure + + + align:start position:0% +right i'm going to measure +these thetas where i get a signal + + align:start position:0% +these thetas where i get a signal + + + align:start position:0% +these thetas where i get a signal +remember i'm going to i'm going to now + + align:start position:0% +remember i'm going to i'm going to now + + + align:start position:0% +remember i'm going to i'm going to now +change + + align:start position:0% +change + + + align:start position:0% +change +theta so that i see where do i get + + align:start position:0% +theta so that i see where do i get + + + align:start position:0% +theta so that i see where do i get +signals + + align:start position:0% +signals + + + align:start position:0% +signals +right now those thetas + + align:start position:0% +right now those thetas + + + align:start position:0% +right now those thetas +divided by the plane that that that by + + align:start position:0% +divided by the plane that that that by + + + align:start position:0% +divided by the plane that that that by +the hkl + + align:start position:0% +the hkl + + + align:start position:0% +the hkl +that they are bouncing off of must be a + + align:start position:0% +that they are bouncing off of must be a + + + align:start position:0% +that they are bouncing off of must be a +constant + + align:start position:0% +constant + + + align:start position:0% +constant +they must not change that is at the + + align:start position:0% +they must not change that is at the + + + align:start position:0% +they must not change that is at the +heart + + align:start position:0% +heart + + + align:start position:0% +heart +of x-ray diffraction that is at the + + align:start position:0% +of x-ray diffraction that is at the + + + align:start position:0% +of x-ray diffraction that is at the +heart of it + + align:start position:0% +heart of it + + + align:start position:0% +heart of it +right all right so we're going to do + + align:start position:0% +right all right so we're going to do + + + align:start position:0% +right all right so we're going to do +that + + align:start position:0% +that + + + align:start position:0% +that +with a specific example today and friday + + align:start position:0% +with a specific example today and friday + + + align:start position:0% +with a specific example today and friday +but before we do that + + align:start position:0% +but before we do that + + + align:start position:0% +but before we do that +there's another thing that we can + + align:start position:0% +there's another thing that we can + + + align:start position:0% +there's another thing that we can +observe there's another thing that we + + align:start position:0% +observe there's another thing that we + + + align:start position:0% +observe there's another thing that we +can observe oh this is what it would + + align:start position:0% +can observe oh this is what it would + + + align:start position:0% +can observe oh this is what it would +look like + + align:start position:0% +look like + + + align:start position:0% +look like +so here it is right so so now i i've + + align:start position:0% +so here it is right so so now i i've + + + align:start position:0% +so here it is right so so now i i've +changed now + + align:start position:0% +changed now + + + align:start position:0% +changed now +why do we do two theta it's kind of + + align:start position:0% +why do we do two theta it's kind of + + + align:start position:0% +why do we do two theta it's kind of +historical you plot + + align:start position:0% +historical you plot + + + align:start position:0% +historical you plot +x-ray diffraction uh spectra so this is + + align:start position:0% +x-ray diffraction uh spectra so this is + + + align:start position:0% +x-ray diffraction uh spectra so this is +an + + align:start position:0% +an + + + align:start position:0% +an +xrd right x-ray diffraction spectrum + + align:start position:0% +xrd right x-ray diffraction spectrum + + + align:start position:0% +xrd right x-ray diffraction spectrum +this is the intensity of the peaks + + align:start position:0% +this is the intensity of the peaks + + + align:start position:0% +this is the intensity of the peaks +right and these are the peaks this is + + align:start position:0% +right and these are the peaks this is + + + align:start position:0% +right and these are the peaks this is +like this is a beautiful thing i'm + + align:start position:0% +like this is a beautiful thing i'm + + + align:start position:0% +like this is a beautiful thing i'm +seeing a crystal here + + align:start position:0% +seeing a crystal here + + + align:start position:0% +seeing a crystal here +i'm seeing a crystal and by friday you + + align:start position:0% +i'm seeing a crystal and by friday you + + + align:start position:0% +i'm seeing a crystal and by friday you +will be seeing a crystal + + align:start position:0% +will be seeing a crystal + + + align:start position:0% +will be seeing a crystal +that those aren't just peaks those are + + align:start position:0% +that those aren't just peaks those are + + + align:start position:0% +that those aren't just peaks those are +planes in a crystal + + align:start position:0% +planes in a crystal + + + align:start position:0% +planes in a crystal +those are planes in a crystal which + + align:start position:0% +those are planes in a crystal which + + + align:start position:0% +those are planes in a crystal which +tells me not only + + align:start position:0% +tells me not only + + + align:start position:0% +tells me not only +that that i have these planes but it + + align:start position:0% +that that i have these planes but it + + + align:start position:0% +that that i have these planes but it +tells me what crystal i have + + align:start position:0% +tells me what crystal i have + + + align:start position:0% +tells me what crystal i have +but that's not how we start the way we + + align:start position:0% +but that's not how we start the way we + + + align:start position:0% +but that's not how we start the way we +start is we do these measurements and we + + align:start position:0% +start is we do these measurements and we + + + align:start position:0% +start is we do these measurements and we +just read off angles + + align:start position:0% +just read off angles + + + align:start position:0% +just read off angles +so we got to get from there to there to + + align:start position:0% +so we got to get from there to there to + + + align:start position:0% +so we got to get from there to there to +crystal structure so what i want to + + align:start position:0% +crystal structure so what i want to + + + align:start position:0% +crystal structure so what i want to +determine + + align:start position:0% +determine + + + align:start position:0% +determine +is the crystal structure and the lattice + + align:start position:0% +is the crystal structure and the lattice + + + align:start position:0% +is the crystal structure and the lattice +constant that's my goal + + align:start position:0% +constant that's my goal + + + align:start position:0% +constant that's my goal +what i have is a spectrum that looks + + align:start position:0% +what i have is a spectrum that looks + + + align:start position:0% +what i have is a spectrum that looks +like this where all i've done here is + + align:start position:0% +like this where all i've done here is + + + align:start position:0% +like this where all i've done here is +put these specific + + align:start position:0% +put these specific + + + align:start position:0% +put these specific +angles here and you have to be given + + align:start position:0% +angles here and you have to be given + + + align:start position:0% +angles here and you have to be given +okay so it's it this is the aluminum xrd + + align:start position:0% +okay so it's it this is the aluminum xrd + + + align:start position:0% +okay so it's it this is the aluminum xrd +spectrum + + align:start position:0% +spectrum + + + align:start position:0% +spectrum +so it's it's if you shine x-rays on + + align:start position:0% +so it's it's if you shine x-rays on + + + align:start position:0% +so it's it's if you shine x-rays on +aluminum + + align:start position:0% +aluminum + + + align:start position:0% +aluminum +this is what you get if you know also + + align:start position:0% +this is what you get if you know also + + + align:start position:0% +this is what you get if you know also +that those x-rays are + + align:start position:0% +that those x-rays are + + + align:start position:0% +that those x-rays are +from copper which means that lambda is + + align:start position:0% +from copper which means that lambda is + + + align:start position:0% +from copper which means that lambda is +fixed + + align:start position:0% +fixed + + + align:start position:0% +fixed +right so this would be like the in you + + align:start position:0% +right so this would be like the in you + + + align:start position:0% +right so this would be like the in you +know the the information you'd get + + align:start position:0% +know the the information you'd get + + + align:start position:0% +know the the information you'd get +to to start you'd be given this spectrum + + align:start position:0% +to to start you'd be given this spectrum + + + align:start position:0% +to to start you'd be given this spectrum +you you're given these peaks + + align:start position:0% +you you're given these peaks + + + align:start position:0% +you you're given these peaks +and you'll be given this information + + align:start position:0% +and you'll be given this information + + + align:start position:0% +and you'll be given this information +here it's a copper target + + align:start position:0% +here it's a copper target + + + align:start position:0% +here it's a copper target +and from that we can determine the + + align:start position:0% +and from that we can determine the + + + align:start position:0% +and from that we can determine the +crystal structure in the lattice now + + align:start position:0% +crystal structure in the lattice now + + + align:start position:0% +crystal structure in the lattice now +um now there's there's something + + align:start position:0% +um now there's there's something + + + align:start position:0% +um now there's there's something +oh why do we write why do we do two + + align:start position:0% +oh why do we write why do we do two + + + align:start position:0% +oh why do we write why do we do two +theta well it's historical + + align:start position:0% +theta well it's historical + + + align:start position:0% +theta well it's historical +it could have been theta to make all + + align:start position:0% +it could have been theta to make all + + + align:start position:0% +it could have been theta to make all +those dividing by twos + + align:start position:0% +those dividing by twos + + + align:start position:0% +those dividing by twos +go away but instead you can see that as + + align:start position:0% +go away but instead you can see that as + + + align:start position:0% +go away but instead you can see that as +i as i rotate this + + align:start position:0% +i as i rotate this + + + align:start position:0% +i as i rotate this +right this changes by theta this the + + align:start position:0% +right this changes by theta this the + + + align:start position:0% +right this changes by theta this the +detector changes by two theta + + align:start position:0% +detector changes by two theta + + + align:start position:0% +detector changes by two theta +so that's why it's x-ray spectra are + + align:start position:0% +so that's why it's x-ray spectra are + + + align:start position:0% +so that's why it's x-ray spectra are +given in two theta + + align:start position:0% +given in two theta + + + align:start position:0% +given in two theta +there's no other real good reason for it + + align:start position:0% +there's no other real good reason for it + + + align:start position:0% +there's no other real good reason for it +um + + align:start position:0% +um + + + align:start position:0% +um +even though in the bragg condition it's + + align:start position:0% +even though in the bragg condition it's + + + align:start position:0% +even though in the bragg condition it's +not two theta it's theta + + align:start position:0% +not two theta it's theta + + + align:start position:0% +not two theta it's theta +right this comes from geometry okay of + + align:start position:0% +right this comes from geometry okay of + + + align:start position:0% +right this comes from geometry okay of +the planes + + align:start position:0% +the planes + + + align:start position:0% +the planes +and this just comes from historical + + align:start position:0% +and this just comes from historical + + + align:start position:0% +and this just comes from historical +setups and then how you move the the + + align:start position:0% +setups and then how you move the the + + + align:start position:0% +setups and then how you move the the +detector + + align:start position:0% +detector + + + align:start position:0% +detector +okay so what's measured and plotted is + + align:start position:0% +okay so what's measured and plotted is + + + align:start position:0% +okay so what's measured and plotted is +the two theta + + align:start position:0% +the two theta + + + align:start position:0% +the two theta +okay now but before we go before we do + + align:start position:0% +okay now but before we go before we do + + + align:start position:0% +okay now but before we go before we do +this transformation where we take an + + align:start position:0% +this transformation where we take an + + + align:start position:0% +this transformation where we take an +x-ray spectrum + + align:start position:0% +x-ray spectrum + + + align:start position:0% +x-ray spectrum +like this and and we and we get the + + align:start position:0% +like this and and we and we get the + + + align:start position:0% +like this and and we and we get the +information we want + + align:start position:0% +information we want + + + align:start position:0% +information we want +there's one more thing and that is + + align:start position:0% +there's one more thing and that is + + + align:start position:0% +there's one more thing and that is +not all reflections are allowed not all + + align:start position:0% +not all reflections are allowed not all + + + align:start position:0% +not all reflections are allowed not all +reflections are allowed + + align:start position:0% +reflections are allowed + + + align:start position:0% +reflections are allowed +and and so and so let's talk about that + + align:start position:0% +and and so and so let's talk about that + + + align:start position:0% +and and so and so let's talk about that +and then we'll come back to this + + align:start position:0% +and then we'll come back to this + + + align:start position:0% +and then we'll come back to this +spectrum right + + align:start position:0% +spectrum right + + + align:start position:0% +spectrum right +now you can you can kind of understand + + align:start position:0% +now you can you can kind of understand + + + align:start position:0% +now you can you can kind of understand +this + + align:start position:0% +this + + + align:start position:0% +this +by looking at just a simple uh kind of + + align:start position:0% +by looking at just a simple uh kind of + + + align:start position:0% +by looking at just a simple uh kind of +comparison here + + align:start position:0% +comparison here + + + align:start position:0% +comparison here +okay simple comparison all right if i + + align:start position:0% +okay simple comparison all right if i + + + align:start position:0% +okay simple comparison all right if i +take so these are the hkls remember + + align:start position:0% +take so these are the hkls remember + + + align:start position:0% +take so these are the hkls remember +that's the hkl for a miller plane + + align:start position:0% +that's the hkl for a miller plane + + + align:start position:0% +that's the hkl for a miller plane +uh this is h squared plus k squared plus + + align:start position:0% +uh this is h squared plus k squared plus + + + align:start position:0% +uh this is h squared plus k squared plus +l squared why do we put that + + align:start position:0% +l squared why do we put that + + + align:start position:0% +l squared why do we put that +because we know we're going to need it + + align:start position:0% +because we know we're going to need it + + + align:start position:0% +because we know we're going to need it +right there it is right there + + align:start position:0% +right there it is right there + + + align:start position:0% +right there it is right there +so we know we're going to need it okay + + align:start position:0% +so we know we're going to need it okay + + + align:start position:0% +so we know we're going to need it okay +but if you look at the simple cubic + + align:start position:0% +but if you look at the simple cubic + + + align:start position:0% +but if you look at the simple cubic +that's simple cubic + + align:start position:0% +that's simple cubic + + + align:start position:0% +that's simple cubic +right any combination of hkl is okay + + align:start position:0% +right any combination of hkl is okay + + + align:start position:0% +right any combination of hkl is okay +there is no combination that would that + + align:start position:0% +there is no combination that would that + + + align:start position:0% +there is no combination that would that +would give you + + align:start position:0% +would give you + + + align:start position:0% +would give you +interference along that along those + + align:start position:0% +interference along that along those + + + align:start position:0% +interference along that along those +planes stacking + + align:start position:0% +planes stacking + + + align:start position:0% +planes stacking +let me say well i don't okay yeah what + + align:start position:0% +let me say well i don't okay yeah what + + + align:start position:0% +let me say well i don't okay yeah what +are you talking about + + align:start position:0% +are you talking about + + + align:start position:0% +are you talking about +why are you even bringing this up well + + align:start position:0% +why are you even bringing this up well + + + align:start position:0% +why are you even bringing this up well +when you see the other two crystal + + align:start position:0% +when you see the other two crystal + + + align:start position:0% +when you see the other two crystal +structures you'll see what i mean + + align:start position:0% +structures you'll see what i mean + + + align:start position:0% +structures you'll see what i mean +so now we have the case of bcc right + + align:start position:0% +so now we have the case of bcc right + + + align:start position:0% +so now we have the case of bcc right +when you see this you see bcc + + align:start position:0% +when you see this you see bcc + + + align:start position:0% +when you see this you see bcc +and fcc and what i'm showing you here + + align:start position:0% +and fcc and what i'm showing you here + + + align:start position:0% +and fcc and what i'm showing you here +isn't the 100 plane + + align:start position:0% +isn't the 100 plane + + + align:start position:0% +isn't the 100 plane +it's the 20 plane right so this is the + + align:start position:0% +it's the 20 plane right so this is the + + + align:start position:0% +it's the 20 plane right so this is the +family remember the family + + align:start position:0% +family remember the family + + + align:start position:0% +family remember the family +of two old planes there they are there + + align:start position:0% +of two old planes there they are there + + + align:start position:0% +of two old planes there they are there +they are + + align:start position:0% +they are + + + align:start position:0% +they are +right oh but now + + align:start position:0% +right oh but now + + + align:start position:0% +right oh but now +now you see that what happens + + align:start position:0% +now you see that what happens + + + align:start position:0% +now you see that what happens +and i have a picture here to show you + + align:start position:0% +and i have a picture here to show you + + + align:start position:0% +and i have a picture here to show you +but i'll tell you first what happens is + + align:start position:0% +but i'll tell you first what happens is + + + align:start position:0% +but i'll tell you first what happens is +the light comes in so there's those + + align:start position:0% +the light comes in so there's those + + + align:start position:0% +the light comes in so there's those +squiggly x-rays + + align:start position:0% +squiggly x-rays + + + align:start position:0% +squiggly x-rays +right it comes in and and there's the + + align:start position:0% +right it comes in and and there's the + + + align:start position:0% +right it comes in and and there's the +okay d + + align:start position:0% +okay d + + + align:start position:0% +okay d +which depends on the lattice constant + + align:start position:0% +which depends on the lattice constant + + + align:start position:0% +which depends on the lattice constant +right is related to the last + + align:start position:0% +right is related to the last + + + align:start position:0% +right is related to the last +but look now there's another plane in + + align:start position:0% +but look now there's another plane in + + + align:start position:0% +but look now there's another plane in +between + + align:start position:0% +between + + + align:start position:0% +between +there's another plane in between and in + + align:start position:0% +there's another plane in between and in + + + align:start position:0% +there's another plane in between and in +fact with the 200 planes + + align:start position:0% +fact with the 200 planes + + + align:start position:0% +fact with the 200 planes +that plane in between exactly cancels + + align:start position:0% +that plane in between exactly cancels + + + align:start position:0% +that plane in between exactly cancels +out the constructive interference here + + align:start position:0% +out the constructive interference here + + + align:start position:0% +out the constructive interference here +it is + + align:start position:0% +it is + + + align:start position:0% +it is +right so there's there's what i would + + align:start position:0% +right so there's there's what i would + + + align:start position:0% +right so there's there's what i would +have had + + align:start position:0% +have had + + + align:start position:0% +have had +right there's the the if you want to + + align:start position:0% +right there's the the if you want to + + + align:start position:0% +right there's the the if you want to +think about this as the 100 + + align:start position:0% +think about this as the 100 + + + align:start position:0% +think about this as the 100 +100 right there's the 2os okay but + + align:start position:0% +100 right there's the 2os okay but + + + align:start position:0% +100 right there's the 2os okay but +notice when i go from 100 to 20s i add + + align:start position:0% +notice when i go from 100 to 20s i add + + + align:start position:0% +notice when i go from 100 to 20s i add +this + + align:start position:0% +this + + + align:start position:0% +this +plane in here and and because that plane + + align:start position:0% +plane in here and and because that plane + + + align:start position:0% +plane in here and and because that plane +has + + align:start position:0% +has + + + align:start position:0% +has +atoms in it because that plane has atoms + + align:start position:0% +atoms in it because that plane has atoms + + + align:start position:0% +atoms in it because that plane has atoms +in it it acts + + align:start position:0% +in it it acts + + + align:start position:0% +in it it acts +like a mirror and it can also reflect + + align:start position:0% +like a mirror and it can also reflect + + + align:start position:0% +like a mirror and it can also reflect +right it can also reflect + + align:start position:0% +right it can also reflect + + + align:start position:0% +right it can also reflect +and so and so what happens is i would + + align:start position:0% +and so and so what happens is i would + + + align:start position:0% +and so and so what happens is i would +have had this nice there it is there's a + + align:start position:0% +have had this nice there it is there's a + + + align:start position:0% +have had this nice there it is there's a +picture i drew there's that + + align:start position:0% +picture i drew there's that + + + align:start position:0% +picture i drew there's that +that first x-ray bouncing off there's + + align:start position:0% +that first x-ray bouncing off there's + + + align:start position:0% +that first x-ray bouncing off there's +the second one bouncing off and those + + align:start position:0% +the second one bouncing off and those + + + align:start position:0% +the second one bouncing off and those +are nicely in phase + + align:start position:0% +are nicely in phase + + + align:start position:0% +are nicely in phase +so i would see that if that's the angle + + align:start position:0% +so i would see that if that's the angle + + + align:start position:0% +so i would see that if that's the angle +that gave that to me i'd see that in the + + align:start position:0% +that gave that to me i'd see that in the + + + align:start position:0% +that gave that to me i'd see that in the +detector + + align:start position:0% +detector + + + align:start position:0% +detector +but now for bcc or fcc i've got + + align:start position:0% +but now for bcc or fcc i've got + + + align:start position:0% +but now for bcc or fcc i've got +something in the middle + + align:start position:0% +something in the middle + + + align:start position:0% +something in the middle +and that something in the middle is + + align:start position:0% +and that something in the middle is + + + align:start position:0% +and that something in the middle is +exactly canceling out + + align:start position:0% +exactly canceling out + + + align:start position:0% +exactly canceling out +you see that so now it cancels that out + + align:start position:0% +you see that so now it cancels that out + + + align:start position:0% +you see that so now it cancels that out +in fact that's + + align:start position:0% +in fact that's + + + align:start position:0% +in fact that's +that's called forbidden you won't see a + + align:start position:0% +that's called forbidden you won't see a + + + align:start position:0% +that's called forbidden you won't see a +signal + + align:start position:0% +signal + + + align:start position:0% +signal +it's right and so and so this is called + + align:start position:0% +it's right and so and so this is called + + + align:start position:0% +it's right and so and so this is called +these are called selection rules right + + align:start position:0% +these are called selection rules right + + + align:start position:0% +these are called selection rules right +these are called selection rules and + + align:start position:0% +these are called selection rules and + + + align:start position:0% +these are called selection rules and +for simple cubic you can see there's + + align:start position:0% +for simple cubic you can see there's + + + align:start position:0% +for simple cubic you can see there's +nothing inside + + align:start position:0% +nothing inside + + + align:start position:0% +nothing inside +right so so there's nothing in this unit + + align:start position:0% +right so so there's nothing in this unit + + + align:start position:0% +right so so there's nothing in this unit +cell + + align:start position:0% +cell + + + align:start position:0% +cell +that could do this so everything's + + align:start position:0% +that could do this so everything's + + + align:start position:0% +that could do this so everything's +allowed whether there's a plane in there + + align:start position:0% +allowed whether there's a plane in there + + + align:start position:0% +allowed whether there's a plane in there +or not + + align:start position:0% +or not + + + align:start position:0% +or not +it doesn't matter the selection rule is + + align:start position:0% +it doesn't matter the selection rule is + + + align:start position:0% +it doesn't matter the selection rule is +whether it's ever allowed + + align:start position:0% +whether it's ever allowed + + + align:start position:0% +whether it's ever allowed +whether it's ever allowed and for simple + + align:start position:0% +whether it's ever allowed and for simple + + + align:start position:0% +whether it's ever allowed and for simple +cubic everything's fine + + align:start position:0% +cubic everything's fine + + + align:start position:0% +cubic everything's fine +because nothing would cancel out but in + + align:start position:0% +because nothing would cancel out but in + + + align:start position:0% +because nothing would cancel out but in +here + + align:start position:0% +here + + + align:start position:0% +here +you see in this 2-0 case you can see + + align:start position:0% +you see in this 2-0 case you can see + + + align:start position:0% +you see in this 2-0 case you can see +very clearly + + align:start position:0% +very clearly + + + align:start position:0% +very clearly +from that picture how it cancels out but + + align:start position:0% +from that picture how it cancels out but + + + align:start position:0% +from that picture how it cancels out but +there's many other kinds of + + align:start position:0% +there's many other kinds of + + + align:start position:0% +there's many other kinds of +kinds of angles or or planes that might + + align:start position:0% +kinds of angles or or planes that might + + + align:start position:0% +kinds of angles or or planes that might +also do that + + align:start position:0% +also do that + + + align:start position:0% +also do that +right and so i'm going to just give you + + align:start position:0% +right and so i'm going to just give you + + + align:start position:0% +right and so i'm going to just give you +what the selection rules are we won't go + + align:start position:0% +what the selection rules are we won't go + + + align:start position:0% +what the selection rules are we won't go +through and derive them all + + align:start position:0% + + + + align:start position:0% + +but let's see they are actually + + align:start position:0% +but let's see they are actually + + + align:start position:0% +but let's see they are actually +quite simple and so i'm going to write + + align:start position:0% +quite simple and so i'm going to write + + + align:start position:0% +quite simple and so i'm going to write +them down + + align:start position:0% +them down + + + align:start position:0% +them down +right so for if we look at allowed + + align:start position:0% + + + + align:start position:0% + +allowed reflections + + align:start position:0% + + + + align:start position:0% + +and then we look at + + align:start position:0% +and then we look at + + + align:start position:0% +and then we look at +forbidden + + align:start position:0% + + + + align:start position:0% + +reflections so this is what the + + align:start position:0% +reflections so this is what the + + + align:start position:0% +reflections so this is what the +selection rules + + align:start position:0% +selection rules + + + align:start position:0% +selection rules +tell us okay so if it's if it's simple + + align:start position:0% +tell us okay so if it's if it's simple + + + align:start position:0% +tell us okay so if it's if it's simple +cubic + + align:start position:0% + + + + align:start position:0% + +then it's any h + + align:start position:0% +then it's any h + + + align:start position:0% +then it's any h +k and l and there's no + + align:start position:0% +k and l and there's no + + + align:start position:0% +k and l and there's no +forbidden reflections but if we go + + align:start position:0% +forbidden reflections but if we go + + + align:start position:0% +forbidden reflections but if we go +through bcc and fcc + + align:start position:0% + + + + align:start position:0% + +then what we find is that for bcc the + + align:start position:0% +then what we find is that for bcc the + + + align:start position:0% +then what we find is that for bcc the +selection rule is that h + + align:start position:0% +selection rule is that h + + + align:start position:0% +selection rule is that h +plus k plus l equals even + + align:start position:0% +plus k plus l equals even + + + align:start position:0% +plus k plus l equals even +if that is even and we won't derive + + align:start position:0% +if that is even and we won't derive + + + align:start position:0% +if that is even and we won't derive +these + + align:start position:0% +these + + + align:start position:0% +these +but it comes from the same very simple + + align:start position:0% +but it comes from the same very simple + + + align:start position:0% +but it comes from the same very simple +picture i just showed you + + align:start position:0% +picture i just showed you + + + align:start position:0% +picture i just showed you +if something is in there that can cancel + + align:start position:0% +if something is in there that can cancel + + + align:start position:0% +if something is in there that can cancel +out the constructive interference + + align:start position:0% +out the constructive interference + + + align:start position:0% +out the constructive interference +it's going to be forbidden otherwise + + align:start position:0% +it's going to be forbidden otherwise + + + align:start position:0% +it's going to be forbidden otherwise +it can constructively interfere and + + align:start position:0% +it can constructively interfere and + + + align:start position:0% +it can constructively interfere and +that's what this tells us h + + align:start position:0% +that's what this tells us h + + + align:start position:0% +that's what this tells us h +for bcc it turns out to be h plus k plus + + align:start position:0% +for bcc it turns out to be h plus k plus + + + align:start position:0% +for bcc it turns out to be h plus k plus +l and so here + + align:start position:0% +l and so here + + + align:start position:0% +l and so here +what's forbidden for bcc is h plus k + + align:start position:0% +what's forbidden for bcc is h plus k + + + align:start position:0% +what's forbidden for bcc is h plus k +plus l + + align:start position:0% +plus l + + + align:start position:0% +plus l +is odd and for fcc + + align:start position:0% +is odd and for fcc + + + align:start position:0% +is odd and for fcc +it's h k l + + align:start position:0% +it's h k l + + + align:start position:0% +it's h k l +all odd + + align:start position:0% + + + + align:start position:0% + +or all even or all even + + align:start position:0% +or all even or all even + + + align:start position:0% +or all even or all even +and the forbidden fcc + + align:start position:0% +and the forbidden fcc + + + align:start position:0% +and the forbidden fcc +is h k l + + align:start position:0% +is h k l + + + align:start position:0% +is h k l +mixed odd even + + align:start position:0% +mixed odd even + + + align:start position:0% +mixed odd even +these are the selection rules + + align:start position:0% + + + + align:start position:0% + +okay all right so if i were to give you + + align:start position:0% +okay all right so if i were to give you + + + align:start position:0% +okay all right so if i were to give you +uh you know if i were to just to give + + align:start position:0% +uh you know if i were to just to give + + + align:start position:0% +uh you know if i were to just to give +you the the planes that you see + + align:start position:0% +you the the planes that you see + + + align:start position:0% +you the the planes that you see +then right away from an x-ray spectrum + + align:start position:0% +then right away from an x-ray spectrum + + + align:start position:0% +then right away from an x-ray spectrum +you could just use these these selection + + align:start position:0% +you could just use these these selection + + + align:start position:0% +you could just use these these selection +rules right away to know something + + align:start position:0% +rules right away to know something + + + align:start position:0% +rules right away to know something +right to know something about it um and + + align:start position:0% +right to know something about it um and + + + align:start position:0% +right to know something about it um and +if you work this out and you look at + + align:start position:0% +if you work this out and you look at + + + align:start position:0% +if you work this out and you look at +okay so we have simple cubic + + align:start position:0% +okay so we have simple cubic + + + align:start position:0% +okay so we have simple cubic +i mean there's this so okay so h squared + + align:start position:0% +i mean there's this so okay so h squared + + + align:start position:0% +i mean there's this so okay so h squared +plus k squared plus they have one + + align:start position:0% +plus k squared plus they have one + + + align:start position:0% +plus k squared plus they have one +100 bcc fcc you're not going to see it + + align:start position:0% +100 bcc fcc you're not going to see it + + + align:start position:0% +100 bcc fcc you're not going to see it +that doesn't mean that there's no 100 + + align:start position:0% +that doesn't mean that there's no 100 + + + align:start position:0% +that doesn't mean that there's no 100 +plane in those crystals + + align:start position:0% +plane in those crystals + + + align:start position:0% +plane in those crystals +it just means that if you shine x-rays + + align:start position:0% +it just means that if you shine x-rays + + + align:start position:0% +it just means that if you shine x-rays +on it you will not see it + + align:start position:0% +on it you will not see it + + + align:start position:0% +on it you will not see it +right you will not see it okay so uh the + + align:start position:0% +right you will not see it okay so uh the + + + align:start position:0% +right you will not see it okay so uh the +1-1-0 though + + align:start position:0% +1-1-0 though + + + align:start position:0% +1-1-0 though +now here okay so we so we see our oh by + + align:start position:0% +now here okay so we so we see our oh by + + + align:start position:0% +now here okay so we so we see our oh by +the way + + align:start position:0% +the way + + + align:start position:0% +the way +mixed even odd right and it adds to odd + + align:start position:0% +mixed even odd right and it adds to odd + + + align:start position:0% +mixed even odd right and it adds to odd +that's why neither one of these works + + align:start position:0% +that's why neither one of these works + + + align:start position:0% +that's why neither one of these works +here we go adds to even + + align:start position:0% +here we go adds to even + + + align:start position:0% +here we go adds to even +bcc okay but it's still mixed even on + + align:start position:0% +bcc okay but it's still mixed even on + + + align:start position:0% +bcc okay but it's still mixed even on +won't be fcc right three + + align:start position:0% +won't be fcc right three + + + align:start position:0% +won't be fcc right three +right it's not mixed so it can it can be + + align:start position:0% +right it's not mixed so it can it can be + + + align:start position:0% +right it's not mixed so it can it can be +a + + align:start position:0% +a + + + align:start position:0% +a +allowable allowable reflection for fcc + + align:start position:0% +allowable allowable reflection for fcc + + + align:start position:0% +allowable allowable reflection for fcc +but not for bcc because if you um + + align:start position:0% +but not for bcc because if you um + + + align:start position:0% +but not for bcc because if you um +add them up it's odd and so forth and so + + align:start position:0% +add them up it's odd and so forth and so + + + align:start position:0% +add them up it's odd and so forth and so +forth and look at seven doesn't exist + + align:start position:0% +forth and look at seven doesn't exist + + + align:start position:0% +forth and look at seven doesn't exist +because you can't do + + align:start position:0% +because you can't do + + + align:start position:0% +because you can't do +no matter how hard you try you can't get + + align:start position:0% +no matter how hard you try you can't get + + + align:start position:0% +no matter how hard you try you can't get +seven + + align:start position:0% +seven + + + align:start position:0% +seven +that's okay and there's eight and nine + + align:start position:0% +that's okay and there's eight and nine + + + align:start position:0% +that's okay and there's eight and nine +and so forth right so nine also + + align:start position:0% +and so forth right so nine also + + + align:start position:0% +and so forth right so nine also +yeah so so right so here it's allowed + + align:start position:0% +yeah so so right so here it's allowed + + + align:start position:0% +yeah so so right so here it's allowed +but it's not allowed + + align:start position:0% +but it's not allowed + + + align:start position:0% +but it's not allowed +in either of these because you can't get + + align:start position:0% +in either of these because you can't get + + + align:start position:0% +in either of these because you can't get +um + + align:start position:0% +um + + + align:start position:0% +um +you can't get the e you know you can't + + align:start position:0% +you can't get the e you know you can't + + + align:start position:0% +you can't get the e you know you can't +get either of these to be satisfied + + align:start position:0% +get either of these to be satisfied + + + align:start position:0% +get either of these to be satisfied +okay this is what selection rules give + + align:start position:0% +okay this is what selection rules give + + + align:start position:0% +okay this is what selection rules give +us + + align:start position:0% +us + + + align:start position:0% +us +and um and it comes again + + align:start position:0% +and um and it comes again + + + align:start position:0% +and um and it comes again +from simple uh uh oh okay well that + + align:start position:0% +from simple uh uh oh okay well that + + + align:start position:0% +from simple uh uh oh okay well that +that's another thing i said simple + + align:start position:0% +that's another thing i said simple + + + align:start position:0% +that's another thing i said simple +i have to tell you something because the + + align:start position:0% +i have to tell you something because the + + + align:start position:0% +i have to tell you something because the +brag condition + + align:start position:0% +brag condition + + + align:start position:0% +brag condition +it relies on an assumption + + align:start position:0% +it relies on an assumption + + + align:start position:0% +it relies on an assumption +that's mostly true but you know the the + + align:start position:0% +that's mostly true but you know the the + + + align:start position:0% +that's mostly true but you know the the +bragg condition + + align:start position:0% + + + + align:start position:0% + +requires + + align:start position:0% + + + + align:start position:0% + +that the reflection is independent + + align:start position:0% +that the reflection is independent + + + align:start position:0% +that the reflection is independent +some of you may be thinking did i did i + + align:start position:0% +some of you may be thinking did i did i + + + align:start position:0% +some of you may be thinking did i did i +draw that onto the atom + + align:start position:0% +draw that onto the atom + + + align:start position:0% +draw that onto the atom +or did i draw it in between the atoms + + align:start position:0% +or did i draw it in between the atoms + + + align:start position:0% +or did i draw it in between the atoms +where did that thing ruffle doesn't have + + align:start position:0% +where did that thing ruffle doesn't have + + + align:start position:0% +where did that thing ruffle doesn't have +to reflect off man + + align:start position:0% +to reflect off man + + + align:start position:0% +to reflect off man +we're not going there with the brag + + align:start position:0% +we're not going there with the brag + + + align:start position:0% +we're not going there with the brag +condition it's independent + + align:start position:0% +condition it's independent + + + align:start position:0% +condition it's independent +independent okay of + + align:start position:0% +independent okay of + + + align:start position:0% +independent okay of +the atom positions in a plane + + align:start position:0% + + + + align:start position:0% + +and the second thing which is what i've + + align:start position:0% +and the second thing which is what i've + + + align:start position:0% +and the second thing which is what i've +been sort of alluding to + + align:start position:0% +been sort of alluding to + + + align:start position:0% +been sort of alluding to +is that the atomic planes are + + align:start position:0% + + + + align:start position:0% + +mirror-like + + align:start position:0% + + + + align:start position:0% + +are mirror-like i mean this is sort of + + align:start position:0% +are mirror-like i mean this is sort of + + + align:start position:0% +are mirror-like i mean this is sort of +an obvious assumption since i've been + + align:start position:0% +an obvious assumption since i've been + + + align:start position:0% +an obvious assumption since i've been +assuming they've been mirrors + + align:start position:0% +assuming they've been mirrors + + + align:start position:0% +assuming they've been mirrors +but you know it's it's not so + + align:start position:0% +but you know it's it's not so + + + align:start position:0% +but you know it's it's not so +if you start thinking about atom + + align:start position:0% +if you start thinking about atom + + + align:start position:0% +if you start thinking about atom +position + + align:start position:0% +position + + + align:start position:0% +position +then you might go back to that you know + + align:start position:0% +then you might go back to that you know + + + align:start position:0% +then you might go back to that you know +that selection rule picture + + align:start position:0% +that selection rule picture + + + align:start position:0% +that selection rule picture +and say oh wait a second why you know + + align:start position:0% +and say oh wait a second why you know + + + align:start position:0% +and say oh wait a second why you know +does it always have to hit the atom + + align:start position:0% +does it always have to hit the atom + + + align:start position:0% +does it always have to hit the atom +there what if this one was over + + align:start position:0% +there what if this one was over + + + align:start position:0% +there what if this one was over +or something like that no no we assume + + align:start position:0% +or something like that no no we assume + + + align:start position:0% +or something like that no no we assume +it's just one continuous plane + + align:start position:0% +it's just one continuous plane + + + align:start position:0% +it's just one continuous plane +if there are atoms in it if there are + + align:start position:0% +if there are atoms in it if there are + + + align:start position:0% +if there are atoms in it if there are +atoms in it + + align:start position:0% +atoms in it + + + align:start position:0% +atoms in it +right if there's no atom in it then it's + + align:start position:0% +right if there's no atom in it then it's + + + align:start position:0% +right if there's no atom in it then it's +not a reflective plane + + align:start position:0% +not a reflective plane + + + align:start position:0% +not a reflective plane +okay but it's continuous in the + + align:start position:0% +okay but it's continuous in the + + + align:start position:0% +okay but it's continuous in the +assumption of of the bragg condition + + align:start position:0% +assumption of of the bragg condition + + + align:start position:0% +assumption of of the bragg condition +okay now um + + align:start position:0% +okay now um + + + align:start position:0% +okay now um +now we go back to our picture okay so + + align:start position:0% +now we go back to our picture okay so + + + align:start position:0% +now we go back to our picture okay so +what we want to do + + align:start position:0% +what we want to do + + + align:start position:0% +what we want to do +is again our goal our goal should we + + align:start position:0% +is again our goal our goal should we + + + align:start position:0% +is again our goal our goal should we +choose + + align:start position:0% +choose + + + align:start position:0% +choose +should we choose our goal is to go from + + align:start position:0% +should we choose our goal is to go from + + + align:start position:0% +should we choose our goal is to go from +this spectrum + + align:start position:0% +this spectrum + + + align:start position:0% +this spectrum +knowing this information right it's a + + align:start position:0% +knowing this information right it's a + + + align:start position:0% +knowing this information right it's a +copper target + + align:start position:0% +copper target + + + align:start position:0% +copper target +and and we and being able to read off + + align:start position:0% +and and we and being able to read off + + + align:start position:0% +and and we and being able to read off +the peaks our goal + + align:start position:0% +the peaks our goal + + + align:start position:0% +the peaks our goal +is to determine the crystal structure + + align:start position:0% +is to determine the crystal structure + + + align:start position:0% +is to determine the crystal structure +and the lattice constant + + align:start position:0% +and the lattice constant + + + align:start position:0% +and the lattice constant +that's our goal and and let me + + align:start position:0% +that's our goal and and let me + + + align:start position:0% +that's our goal and and let me +let me just write this again because + + align:start position:0% +let me just write this again because + + + align:start position:0% +let me just write this again because +it's extremely + + align:start position:0% +it's extremely + + + align:start position:0% +it's extremely +important so i'm gonna i'm gonna maybe + + align:start position:0% +important so i'm gonna i'm gonna maybe + + + align:start position:0% +important so i'm gonna i'm gonna maybe +i'll keep that one + + align:start position:0% +i'll keep that one + + + align:start position:0% +i'll keep that one +i'm gonna ignore i'm gonna erase this + + align:start position:0% +i'm gonna ignore i'm gonna erase this + + + align:start position:0% +i'm gonna ignore i'm gonna erase this +and put it right in the middle + + align:start position:0% +and put it right in the middle + + + align:start position:0% +and put it right in the middle +because this is this is what + + align:start position:0% +because this is this is what + + + align:start position:0% +because this is this is what +drives xrd this is what drives xrd + + align:start position:0% +drives xrd this is what drives xrd + + + align:start position:0% +drives xrd this is what drives xrd +okay which is that our goal + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +figure out + + align:start position:0% +figure out + + + align:start position:0% +figure out +what makes + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% + + + + align:start position:0% + +constant always constant + + align:start position:0% +constant always constant + + + align:start position:0% +constant always constant +now you say what is this constant always + + align:start position:0% +now you say what is this constant always + + + align:start position:0% +now you say what is this constant always +okay this is the expression which i'm + + align:start position:0% +okay this is the expression which i'm + + + align:start position:0% +okay this is the expression which i'm +going to write again just for + + align:start position:0% +going to write again just for + + + align:start position:0% +going to write again just for +so so the what i have if it's a copper + + align:start position:0% +so so the what i have if it's a copper + + + align:start position:0% +so so the what i have if it's a copper +source + + align:start position:0% +source + + + align:start position:0% +source +is 1.54 angstroms divided by 2a + + align:start position:0% +is 1.54 angstroms divided by 2a + + + align:start position:0% +is 1.54 angstroms divided by 2a +squared that's a constant goes in tight + + align:start position:0% +squared that's a constant goes in tight + + + align:start position:0% +squared that's a constant goes in tight +that equals sine squared + + align:start position:0% +that equals sine squared + + + align:start position:0% +that equals sine squared +of the theta for some plane divided by + + align:start position:0% +of the theta for some plane divided by + + + align:start position:0% +of the theta for some plane divided by +h squared plus k squared + + align:start position:0% +h squared plus k squared + + + align:start position:0% +h squared plus k squared +plus l squared so i'm just kind of + + align:start position:0% +plus l squared so i'm just kind of + + + align:start position:0% +plus l squared so i'm just kind of +repeating what i've said and what i've + + align:start position:0% +repeating what i've said and what i've + + + align:start position:0% +repeating what i've said and what i've +written elsewhere but that is really it + + align:start position:0% +written elsewhere but that is really it + + + align:start position:0% +written elsewhere but that is really it +that is what we do in x-ray diffraction + + align:start position:0% +that is what we do in x-ray diffraction + + + align:start position:0% +that is what we do in x-ray diffraction +what makes this well by this + + align:start position:0% +what makes this well by this + + + align:start position:0% +what makes this well by this +what i mean is this term on the right + + align:start position:0% +what i mean is this term on the right + + + align:start position:0% +what i mean is this term on the right +how do i make sure that this never + + align:start position:0% +how do i make sure that this never + + + align:start position:0% +how do i make sure that this never +changes its value + + align:start position:0% +changes its value + + + align:start position:0% +changes its value +because the thing on the left never + + align:start position:0% +because the thing on the left never + + + align:start position:0% +because the thing on the left never +changes its value + + align:start position:0% +changes its value + + + align:start position:0% +changes its value +right and just making sure that you've + + align:start position:0% +right and just making sure that you've + + + align:start position:0% +right and just making sure that you've +got that concept + + align:start position:0% +got that concept + + + align:start position:0% +got that concept +that is this oh yeah + + align:start position:0% + + + + align:start position:0% + +okay and and it turns out + + align:start position:0% +okay and and it turns out + + + align:start position:0% +okay and and it turns out +i got i got a set i got a recipe for you + + align:start position:0% +i got i got a set i got a recipe for you + + + align:start position:0% +i got i got a set i got a recipe for you +to follow to do this and it's on the + + align:start position:0% +to follow to do this and it's on the + + + align:start position:0% +to follow to do this and it's on the +previous slide and so so we'll start + + align:start position:0% +previous slide and so so we'll start + + + align:start position:0% +previous slide and so so we'll start +thinking about it + + align:start position:0% +thinking about it + + + align:start position:0% +thinking about it +now and we've got five more minutes and + + align:start position:0% +now and we've got five more minutes and + + + align:start position:0% +now and we've got five more minutes and +then on friday we will + + align:start position:0% +then on friday we will + + + align:start position:0% +then on friday we will +we will finish this and then talk about + + align:start position:0% +we will finish this and then talk about + + + align:start position:0% +we will finish this and then talk about +what to do with those continuous x-rays + + align:start position:0% +what to do with those continuous x-rays + + + align:start position:0% +what to do with those continuous x-rays +so what do i do well the the way you do + + align:start position:0% +so what do i do well the the way you do + + + align:start position:0% +so what do i do well the the way you do +this is systematically + + align:start position:0% +this is systematically + + + align:start position:0% +this is systematically +because in tight the way you do this is + + align:start position:0% +because in tight the way you do this is + + + align:start position:0% +because in tight the way you do this is +systematically + + align:start position:0% +systematically + + + align:start position:0% +systematically +and the first thing you do is you read + + align:start position:0% +and the first thing you do is you read + + + align:start position:0% +and the first thing you do is you read +off the two theta values + + align:start position:0% +off the two theta values + + + align:start position:0% +off the two theta values +okay that generate a set of sine squared + + align:start position:0% +okay that generate a set of sine squared + + + align:start position:0% +okay that generate a set of sine squared +values so + + align:start position:0% +values so + + + align:start position:0% +values so +the x-ray spectrum measures 2 theta but + + align:start position:0% +the x-ray spectrum measures 2 theta but + + + align:start position:0% +the x-ray spectrum measures 2 theta but +we know from here that i need sine + + align:start position:0% +we know from here that i need sine + + + align:start position:0% +we know from here that i need sine +squared + + align:start position:0% +squared + + + align:start position:0% +squared +okay so i'm going to write down the sine + + align:start position:0% +okay so i'm going to write down the sine + + + align:start position:0% +okay so i'm going to write down the sine +squared values + + align:start position:0% +squared values + + + align:start position:0% +squared values +okay so that's a first step so + + align:start position:0% + + + + align:start position:0% + +okay good right so for the first one + + align:start position:0% +okay good right so for the first one + + + align:start position:0% +okay good right so for the first one +i've got uh okay so i've got the first + + align:start position:0% +i've got uh okay so i've got the first + + + align:start position:0% +i've got uh okay so i've got the first +peak + + align:start position:0% +peak + + + align:start position:0% +peak +so i would start to log my data right + + align:start position:0% +so i would start to log my data right + + + align:start position:0% +so i would start to log my data right +the first peak + + align:start position:0% +the first peak + + + align:start position:0% +the first peak +and the 2 theta is 38.43 + + align:start position:0% +and the 2 theta is 38.43 + + + align:start position:0% +and the 2 theta is 38.43 +and the sine squared theta okay + + align:start position:0% +and the sine squared theta okay + + + align:start position:0% +and the sine squared theta okay +is and i'm just going to do that math + + align:start position:0% +is and i'm just going to do that math + + + align:start position:0% +is and i'm just going to do that math +0.1083 + + align:start position:0% +0.1083 + + + align:start position:0% +0.1083 +okay okay good and the next one + + align:start position:0% +okay okay good and the next one + + + align:start position:0% +okay okay good and the next one +the next peak is 44.67 + + align:start position:0% +the next peak is 44.67 + + + align:start position:0% +the next peak is 44.67 +and the sine squared of that is 0.14 + + align:start position:0% +and the sine squared of that is 0.14 + + + align:start position:0% +and the sine squared of that is 0.14 +four four and so on so you read off all + + align:start position:0% +four four and so on so you read off all + + + align:start position:0% +four four and so on so you read off all +the peaks and you make that + + align:start position:0% +the peaks and you make that + + + align:start position:0% +the peaks and you make that +those columns okay so i've gone through + + align:start position:0% +those columns okay so i've gone through + + + align:start position:0% +those columns okay so i've gone through +one now the second one + + align:start position:0% +one now the second one + + + align:start position:0% +one now the second one +normalize the sine squared theta values + + align:start position:0% +normalize the sine squared theta values + + + align:start position:0% +normalize the sine squared theta values +by the smallest value + + align:start position:0% +by the smallest value + + + align:start position:0% +by the smallest value +right okay you say why am i doing that + + align:start position:0% +right okay you say why am i doing that + + + align:start position:0% +right okay you say why am i doing that +trust me + + align:start position:0% +trust me + + + align:start position:0% +trust me +this will achieve our goal this will get + + align:start position:0% +this will achieve our goal this will get + + + align:start position:0% +this will achieve our goal this will get +us there + + align:start position:0% +us there + + + align:start position:0% +us there +this is a nice simple recipe to achieve + + align:start position:0% +this is a nice simple recipe to achieve + + + align:start position:0% +this is a nice simple recipe to achieve +our goal so the next column + + align:start position:0% +our goal so the next column + + + align:start position:0% +our goal so the next column +would simply be sine squared + + align:start position:0% +would simply be sine squared + + + align:start position:0% +would simply be sine squared +theta divided by sine + + align:start position:0% +theta divided by sine + + + align:start position:0% +theta divided by sine +squared theta min + + align:start position:0% + + + + align:start position:0% + +okay well i ran out of room there but + + align:start position:0% +okay well i ran out of room there but + + + align:start position:0% +okay well i ran out of room there but +that's going to be obviously + + align:start position:0% +that's going to be obviously + + + align:start position:0% +that's going to be obviously +one and this would be one point + + align:start position:0% +one and this would be one point + + + align:start position:0% +one and this would be one point +three three three and so on + + align:start position:0% +three three three and so on + + + align:start position:0% +three three three and so on +so that's the next one so i'm just i'm + + align:start position:0% +so that's the next one so i'm just i'm + + + align:start position:0% +so that's the next one so i'm just i'm +just setting the + + align:start position:0% +just setting the + + + align:start position:0% +just setting the +the top row to one + + align:start position:0% +the top row to one + + + align:start position:0% +the top row to one +okay i'm setting the top row of 1. so + + align:start position:0% +okay i'm setting the top row of 1. so + + + align:start position:0% +okay i'm setting the top row of 1. so +that's + + align:start position:0% +that's + + + align:start position:0% +that's +okay good now i'm going to clear + + align:start position:0% +okay good now i'm going to clear + + + align:start position:0% +okay good now i'm going to clear +fractions so i've normalized and now i'm + + align:start position:0% +fractions so i've normalized and now i'm + + + align:start position:0% +fractions so i've normalized and now i'm +going to clear fractions + + align:start position:0% +going to clear fractions + + + align:start position:0% +going to clear fractions +and if i do that if i clear fractions + + align:start position:0% +and if i do that if i clear fractions + + + align:start position:0% +and if i do that if i clear fractions +well you know you say i what is does + + align:start position:0% +well you know you say i what is does + + + align:start position:0% +well you know you say i what is does +clearing fractions mean + + align:start position:0% +clearing fractions mean + + + align:start position:0% +clearing fractions mean +it means just what it implies i don't + + align:start position:0% +it means just what it implies i don't + + + align:start position:0% +it means just what it implies i don't +want fractions anymore so i'm going to + + align:start position:0% +want fractions anymore so i'm going to + + + align:start position:0% +want fractions anymore so i'm going to +multiply it means i just need to + + align:start position:0% +multiply it means i just need to + + + align:start position:0% +multiply it means i just need to +multiply + + align:start position:0% +multiply + + + align:start position:0% +multiply +the whole set of numbers by by something + + align:start position:0% +the whole set of numbers by by something + + + align:start position:0% +the whole set of numbers by by something +that gets rid of the fractions and it + + align:start position:0% +that gets rid of the fractions and it + + + align:start position:0% +that gets rid of the fractions and it +turns out + + align:start position:0% +turns out + + + align:start position:0% +turns out +that in this case it is three so + + align:start position:0% +that in this case it is three so + + + align:start position:0% +that in this case it is three so +three times + + align:start position:0% +three times + + + align:start position:0% +three times +sine squared theta over sine squared + + align:start position:0% +sine squared theta over sine squared + + + align:start position:0% +sine squared theta over sine squared +theta min + + align:start position:0% + + + + align:start position:0% + +and that is going to be three and that + + align:start position:0% +and that is going to be three and that + + + align:start position:0% +and that is going to be three and that +is going to be four + + align:start position:0% +is going to be four + + + align:start position:0% +is going to be four +and so on okay so this is this is the + + align:start position:0% +and so on okay so this is this is the + + + align:start position:0% +and so on okay so this is this is the +product now + + align:start position:0% + + + + align:start position:0% + +we're almost there we're almost there + + align:start position:0% +we're almost there we're almost there + + + align:start position:0% +we're almost there we're almost there +and we're not going to finish today but + + align:start position:0% +and we're not going to finish today but + + + align:start position:0% +and we're not going to finish today but +we're getting real close + + align:start position:0% +we're getting real close + + + align:start position:0% +we're getting real close +that's good it leaves us with a sense of + + align:start position:0% +that's good it leaves us with a sense of + + + align:start position:0% +that's good it leaves us with a sense of +anticipation + + align:start position:0% +anticipation + + + align:start position:0% +anticipation +and excitement right so + + align:start position:0% +and excitement right so + + + align:start position:0% +and excitement right so +okay i got clear fractions what values + + align:start position:0% +okay i got clear fractions what values + + + align:start position:0% +okay i got clear fractions what values +of + + align:start position:0% +of + + + align:start position:0% +of +hkl if i have this h squared plus k + + align:start position:0% +hkl if i have this h squared plus k + + + align:start position:0% +hkl if i have this h squared plus k +squared plus l squared + + align:start position:0% +squared plus l squared + + + align:start position:0% +squared plus l squared +would give me the sequence of clear + + align:start position:0% +would give me the sequence of clear + + + align:start position:0% +would give me the sequence of clear +fractions what values of h + + align:start position:0% +fractions what values of h + + + align:start position:0% +fractions what values of h +now remember you say why am i doing this + + align:start position:0% +now remember you say why am i doing this + + + align:start position:0% +now remember you say why am i doing this +again go back to this this is why + + align:start position:0% +again go back to this this is why + + + align:start position:0% +again go back to this this is why +i have a simple recipe for you to + + align:start position:0% +i have a simple recipe for you to + + + align:start position:0% +i have a simple recipe for you to +accomplish this goal + + align:start position:0% +accomplish this goal + + + align:start position:0% +accomplish this goal +that's where we're going with this right + + align:start position:0% +that's where we're going with this right + + + align:start position:0% +that's where we're going with this right +okay so so + + align:start position:0% +okay so so + + + align:start position:0% +okay so so +i'm now gonna see with those clear + + align:start position:0% +i'm now gonna see with those clear + + + align:start position:0% +i'm now gonna see with those clear +fractions now it's very easy + + align:start position:0% +fractions now it's very easy + + + align:start position:0% +fractions now it's very easy +to see what hkls would give me h squared + + align:start position:0% +to see what hkls would give me h squared + + + align:start position:0% +to see what hkls would give me h squared +plus k plus + + align:start position:0% +plus k plus + + + align:start position:0% +plus k plus +h squared plus k squared plus l squared + + align:start position:0% +h squared plus k squared plus l squared + + + align:start position:0% +h squared plus k squared plus l squared +equals that clear fraction value + + align:start position:0% +equals that clear fraction value + + + align:start position:0% +equals that clear fraction value +right so for example you know + + align:start position:0% +right so for example you know + + + align:start position:0% +right so for example you know +here well if this is h squared plus k + + align:start position:0% +here well if this is h squared plus k + + + align:start position:0% +here well if this is h squared plus k +squared plus l squared maybe this is one + + align:start position:0% +squared plus l squared maybe this is one + + + align:start position:0% +squared plus l squared maybe this is one +one one + + align:start position:0% +one one + + + align:start position:0% +one one +right and this might be two zero zero + + align:start position:0% +right and this might be two zero zero + + + align:start position:0% +right and this might be two zero zero +for example okay + + align:start position:0% + + + + align:start position:0% + +so we're almost there we're so close um + + align:start position:0% +so we're almost there we're so close um + + + align:start position:0% +so we're almost there we're so close um +what we're gonna do is i'm gonna start + + align:start position:0% +what we're gonna do is i'm gonna start + + + align:start position:0% +what we're gonna do is i'm gonna start +on friday i'll put this up on the board + + align:start position:0% +on friday i'll put this up on the board + + + align:start position:0% +on friday i'll put this up on the board +and we'll finish filling it out and + + align:start position:0% +and we'll finish filling it out and + + + align:start position:0% +and we'll finish filling it out and +going from this matrix + + align:start position:0% +going from this matrix + + + align:start position:0% +going from this matrix +to the crystal structure and the lattice + + align:start position:0% +to the crystal structure and the lattice + + + align:start position:0% +to the crystal structure and the lattice +constant okay + + align:start position:0% +constant okay + + + align:start position:0% +constant okay +have a great halloween + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/BRjwkgQct28.txt b/BRjwkgQct28.txt new file mode 100644 index 0000000000000000000000000000000000000000..b3c723c5a9c9a71f5cf974c6fe34f7aadf80a692 --- /dev/null +++ b/BRjwkgQct28.txt @@ -0,0 +1,1897 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Good morning, +everybody. + +All right, I ended up the last +lecture talking about how to + +calculate the absolute +goodness of fit using + +something called the coefficient +of determination. + +It's usually spelled as +R-squared, or R2. + +And the formula was +quite simple. + +We measure the goodness of the +fit as R-squared equals 1 + +minus the estimated +error divided by + +the measured variance. + +As I observed, R-squared always +lies between 0 and 1. + +If R-squared equals 1, that +means that the model that we + +constructed, the predicted +values if you will, explains + +all of the variability in the +data so that any change in the + +data is explained perfectly +by the model. + +We don't usually get 1. + +In fact, if I ever got +1, I would think + +somebody cheated me. + +R-squared equals 0, or +conversely, it means there's + +no linear relationship at all +between the values predicted + +by the model and the +actual data. + +That is to say, the model +is totally worthless. + +So we have code here, the top +of the screen, showing how + +easy it is to compute +R-squared. + +And for those of you who have a +little trouble interpreting + +the formula, because maybe +you're not quite sure what EE + +and MV mean, this will give you +a very straightforward way + +to understand it. + +So now, we can run it. + +We can get some answers. + +So if we look at it, you'll +remember last time, we looked + +at two different fits. + +We looked at a quadratic fit +and a linear fit for the + +trajectory of an arrow +fired from my bow. + +And we can now compare +the two. + +And not surprisingly, given what +we know about the physics + +of projectiles, we see it is +exactly what we'd expect, that + +the linear fit has an R-quared +of 0.0177, showing that, in + +fact, it explains almost +none of the data. + +Whereas the quadratic fit has +a really astonishingly good + +R-squared of 0.98, saying that +almost all of the changes in + +the values of the variables, +that is to say the way the y + +value changes with respect +to the x value, is + +explained by the model. + +i.e., we have a really +good model of + +the physical situation. + +Very comforting. + +Essentially, it's telling us +at less than 2% of the + +variation is explained by the +linear model, 98% by the + +quadratic model. + +Presumably the other 2% +is experimental error. + +Well, now that we know that we +have a really good model of + +the data, we can ask the +question, why do we care? + +We have the data itself. + +What's the point of building +a model of the data? + +And that, of course, is what +we're getting when we run + +polyfit to get this curve. + +The whole purpose of creating +a model, or an important + +purpose of creating a model, +is to be able to answer + +questions about the actual +physical situation. + +So one of the questions one +might ask, for example, about + +firing an arrow is, how +fast is it going? + +That's kind of a useful thing +to know if you're worried + +about whether it will penetrate +a target and kill + +somebody on the other +side, for example. + +We can't answer that +question directly + +looking at the data points. + +You look at the data. + +Well, I don't know. + +But we can use the model +to answer the question. + +And that's an exercise I want to +go through now to show you + +the interplay between models, +and theory, and computation, + +and how we can use the three to +answer relevant questions + +about data. + +No, I do not want to check for +new software, thank you. + +In fact, let's make sure it +won't do that anymore. + +So let's look at +the PowerPoint. + +So here, we'll see how I'm using +a little bit of theory, + +not very much, to be able to +understand how to use the + +model to compute the +speed of the arrow. + +So what we see is we know by +our model, and by the good + +fit, that the trajectory is +given by y equals ax-squared + +plus bx plus c. + +We know that. + +We also know from looking at +this equation that the highest + +point, which I'll call yPeak, +of the arrow must occur at + +xMid, the middle +of the x-axis. + +So if we look at a parabola, and +it doesn't matter what the + +parabola is, we always know +that the vertical peak is + +halfway along the x-axis. + +The math tells us that +from the equation. + +So we can say yPeak is x times +xMid squared plus b + +times xMid plus c. + +So now, we have a model that +we can tell how high + +the arrow can get. + +The next question I'll ask is +if I fired the arrow from + +here, and it hits the +target here-- + +I've exaggerated +by it this way. + +It's nowhere near this steep. + +How long does it take to +get from here to here? + +We don't have anything about +time in our data. + +Yet, I claim we have enough +information to go from the + +distance here and the distance +here to how long it's going to + +take the arrow to get from +here to the target. + +Why do I know that? + +What determines how long it's +going to take to get + +from here to here? + +It's going to be how long it +takes it to fall that far. + +It's going to be gravity. + +Because we know that gravity, at +least on this planet, is a + +constant or close +enough to it. + +Unless maybe the arrow were +going a million miles. + +And it's going to be gravity +that tells me how long it + +takes to get from +here to here. + +And when it gets to the bottom, +it's going to be here, + +So again, I can use some very +simple math and say that the + +time will be the square root of +2 times the yPeak divided + +by the gravitational constant. + +Because I know that however long +it takes to get from this + +height to this height is going +to be the same time it takes + +to get from this point +to this point. + +And that will therefore let me +compute the average speed from + +here to here. + +And once I know that, +I'm done. + +Now again, this is assuming no +drag and things like that. + +The thing that we always have to +understand about a model is + +no model is actually +ever correct. + +On the other hand, many models +are very useful and they're + +close enough to correct. + +So I left out things like +gravity, wind shear + +and stuff like that. + +But in fact, the answer we get +here will turn out to be very + +close to correct. + +We can now go back and +look at some code. + +Get rid of this. + +And so now, you'll see +this on the handout. + +I'm going to just write a little +bit of code that just + +goes through the math I just +showed you to compute the + +average x velocity. + +Got a print statement here +I use to debug it. + +And I'm going to return it. + +And then, we'll just be able to +run it and see what we get. + +Well, all right, that +we looked at before. + +I forgot to close the +previous figure. + +So now, I'm sure this is a +problem you've all seen. + +And we'll fix it the +way we always fix + +things, just start over. + +I'll bet you guys have also +seen this happen. + +What this is suggesting, as +we've seen before, is that the + +process, the old process, +still exists. + +Not a good thing. + +Again, I'm sure you've +all seen these. + +Let's make sure we don't have +anything running here that + +looks like IDLE. + +We don't. + +Just takes it a little time. + +There it is, all right. + +All right, now we'll go back. + +All of this happened because I +forgot to close the figure and + +executed pyLab.show twice, +which we know + +can lead to bad things. + +So let's get rid of this. + +Now, we'll run it. + +And now, we have our figure just +using the quadratic fit. + +And we see that the speed is +136.25 feet per second. + +Do I believe 136.25? + +Not really. + +I know it's the ballpark. + +I confused precision with +accuracy here by giving you it + +to two decimal places. + +I can compute it as precisely +as I want. + +But that doesn't mean it's +actually accurate. + +Probably, I should have just +said it's about 135 or + +something like that. + +But it's pretty good. + +And for those of who don't know +how to do this arithmetic + +in your head like me, this is +about 93 miles per hour. + +And for comparison, the speed of +sound, instead of 136 feet + +per second, is 1,100 +feet per second. + +So it's traveling pretty fast. + +Well, what's the +point of this? + +I don't really care +if you know how + +fast an arrow travels. + +I don't expect you'll ever +need to compute that. + +But I wanted to show you this +as an example of a pattern + +that we use a lot. + +So what we did is we started +with an experiment. + +You didn't see this, but I +actually stood in my backyard + +and shot a bunch of arrows and +measured them, got real data + +out of that. + +And this gave me some data +about the behavior of a + +physical system. + +That's what I get for +wearing a tie. + +Maybe it'll be quieter if +I put it in my shirt. + +Actually, it looks silly. + +Excuse me. + +I hope none of you will mind +if I take my tie off? + +It seems to be making noises +in the microphone. + +Maybe we should write +a computation. + +All right, so ends my +experiment with + +trying to look dignified. + +Not something I'm good at. + +OK, had an experiment. + +That gave us some data. + +We then use computation to both +find and very importantly + +evaluate a model. + +It's no good just to +find the model. + +You need to do some evaluation +to convince yourself that it's + +a good model of the actual +physical system. + +And then, finally, we use some +theory and analysis and + +computation to derive the +consequence of the model. + +And then, since we believe the +accuracy of the model, we + +assume this consequence was +also a true fact about the + +physical system we +started with. + +This is a pattern that we see +over and over again these days + +in all branches of science +and engineering. + +And it's just the kind +of thing that you + +should get used to doing. + +It is what you will do if you go +onto a career in science or + +engineering. + +OK, that's all I want to say +now about the topic of data + +and experiments and analysis. + +We will return to this topic +of interpretation of data + +later in the semester near the +end when we start talking + +about machine learning +and clustering. + +But for now, I want to pull +back and start down a new + +track that will, I'm sure you'll +be pleased to hear, + +dovetail nicely with the next +few problem sets that you're + +going to have to work on. + +What I want to talk about is +the topic of optimization. + +Not so much optimization in the +sense of how do you make a + +program fast, though we will +talk a little about that, but + +what people refer to as +optimization problems. + +How do we write programs to +find optimal solutions to + +problems that occur +in real life? + +Every optimization problem +we'll look at is + +going to have two parts. + +There's going to be (1) an +objective function that will + +either be maximized +or minimized. + +So for example, I might want to +find the minimal air fare + +between Boston and Istanbul. + +Or more likely, the minimum +bus fare between + +Boston and New York. + +So there's an objective +function. + +Sometimes, you find the least. + +Sometimes, you find the most. + +Maybe I want to maximize +my income. + +And (2) a set of constraints +that have to be satisfied. + +So maybe I want to find the +minimum transportation, + +minimum cost transportation +between Boston and New York + +subject to the constraint that +it not take more than eight + +hours or some such thing. + +So the objective function that +you're minimizing or + +maximizing, and some +set of constraints + +that must be obeyed. + +A vast number of problems of +practical importance can be + +formulated this way. + +Once we've formulated in this +systematic way, we can then + +think about how to attack them +with a computation that will + +help us solve the problem. + +You guys do this all the time. + +I heard a talk yesterday by +Jeremy Wertheimer, an MIT + +graduate, who founded a +company called ITA. + +If you ever use Kayak, for +example, or many of these + +systems to find an airline +fare, they use some of + +Jeremy's code and algorithms +to solve these various + +optimization problems +like this. + +If you've ever used Google or +Bing, they solve optimization + +problems to decide what +pages to show you. + +They're all over the place. + +There are a lot of classic +optimization problems that + +people have worked +on for decades. + +What we often do when confronted +with a new problem, + +and it's something you'll get +some experience on in problem + +sets, is take a seemingly new +problem and map it onto a + +classic problem, and then use +one of the classic solutions. + +So we'll go through this +section of the course. + +And we'll look at a number of +classic optimization problems. + +And then, you can think about +how you would map other + +problems onto those. + +This is the process known as +problem reduction, where we + +take a problem and map it onto +an existing problem that we + +already know how to solve. + +I'm not going to go through a +list of classic optimization + +problems right now. + +But we'll see a bunch of +them as we go forward. + +Now, an important thing to +think about when we think + +about optimization problems +is how long, how + +hard, they are to solve. + +So far, we have looked at +problems that, for the most + +part, have pretty fast +solutions, often sub-linear, + +binary search, sometimes linear, +and at worst case, + +low-order polynomials. + +Optimization problems, as we'll +see, are typically much + +worse than that. + +In fact, what we'll see +is there is often no + +computationally efficient +way to solve them. + +And so we end up dealing with +approximate solutions to them, + +or what people might call +best effort solutions. + +And we see that as +an increasing + +trend in tackling problems. + +All right, enough of this +abstract stuff. + +Let's look at an example. + +So one of the classic +optimization problems is + +called the knapsack problem. + +People know what +a knapsack is? + +Sort of an archaic term. + +Today, people would use +the word backpack. + +But in the old days, they called +them knapsacks when + +they started looking +at these things. + +And the problem is also +discussed in the context of a + +burglar or various +kinds of thieves. + +So it's not easy being a +burglar, by the way. + +I don't know if any of +you ever tried it. + +You've got some of the obvious +problems, like making sure the + +house is empty and +picking locks, + +circumventing alarms, et cetera. + +But one of the really hard +problems a burglar has to deal + +with is deciding +what to steal. + +Because you break into the +typical luxury home-- and why + +would you break into a +poor person's house + +if you were a burglar-- + +there's usually far more to +steal than you can carry away. + +And so the problem is formulated +in terms of the + +burglar having a backpack. + +They can put a certain amount +of stuff in it. + +And they have to maximize the +value of what they steal + +subject to the constraint of +how much weight they can + +actually carry. + +So it's a classic optimization +problem. + +And people have worked for years +at how to solve it, not + +so much because they want +to be burglars. + +But as you'll see, these kinds +of optimization problems are + +actually quite common. + +So let's look at an example. + +You break into the house. + +And among other things, +you have a + +choice of what to steal. + +You have a rather strange +looking clock, some artwork, a + +book, a Velvet Elvis in case +you lean in that direction, + +all sorts of things. + +And for some reason, the owner +was nice enough to leave you + +information about how much +everything cost and how much + +it weighed. + +So you find this +piece of paper. + +And now, you're trying to decide +what to steal based + +upon this in a way to +maximize your value. + +How do we go about doing it? + +Oh, I should show +you, by the way. + +There's a picture of +a typical knapsack. + +All right, it's almost +Easter, after all. + +Well, the simplest solution is +probably a greedy algorithm. + +And we'll talk a lot about +greedy algorithms because they + +are very popular and often +the right way to + +tackle a hard problem. + +So the notion of a greedy +algorithm is it's iterative. + +And at each step, you pick the +locally optimal solution. + +So you make the best choice, put +that item in the knapsack. + +Ask if you have room, if +you're out of weight. + +If not, you make the best choice +of the remaining ones. + +Ask the same question. + +You do that until you can't +fit anything else in. + +Now of course, to do that, that +assumes that we know at + +each stage what we mean +by locally optimal. + +And of course, we have +choices here. + +We're trying to figure out, +in some sense, what greedy + +algorithm, what approach to +being greedy, will give us the + +best result. + +So one could, for example, +say, all right. + +At each step, I'll choose the +most valuable item and put + +that in my knapsack. + +And I'll do that till I run +out of valuable items. + +Or, you could, at each step, +say, well, what I'm really + +going to choose is the one +that weights the least. + +That will give me +the most items. + +And maybe that will give +me the most total + +value when I'm done. + +Or maybe, at each step, you +could say, well, let me choose + +the one that has the best +value to weight ratio + +and put that in. + +And maybe that will give +me the best solution. + +As we will see, in this case, +none of those is guaranteed to + +give you the best solution +all the time. + +In fact, as we'll see, none of +them is guaranteed to be + +better than any of the +others all the time. + +And that's one of the issues +with greedy algorithms. + +I should point out, by the way, +that this version of the + +knapsack problem that we're +talking about is typically + +called the 0/1 knapsack +problem. + +And that's because we either +have to take the entire item + +or none of the item. + +We're not allowed to cut the +Velvet Elvis in half and take + +half of it. + +This is in contrast to the +continuous knapsack problem. + +If you imagine you break into +the house and you see a barrel + +of gold dust, and a barrel of +silver dust, and a barrel of + +raisins, what you would do is +you would fill your knapsack + +with as much gold as you +could carry, or until + +you ran out of gold. + +And then, you would fill it +with as much silver as you + +could carry. + +And then, if there's +any room left, + +you'd put in the raisins. + +For the continuous knapsack +problem, a greedy algorithm + +provides an optimal solution. + +Unfortunately, most of the +problems we actually encounter + +in life, as we'll see, are +0/1 knapsack problems. + +You either take something +or you don't. + +And that's more complicated. + +All right, let's look +at some code. + +So I'm going to formulate it. + +I'm first going to start by +putting in a class, just so + +the rest of my code +is simpler. + +This is something we've been +talking about, that + +increasingly people want to +start by putting in some + +useful data abstractions. + +So I've got a class item where +I can put in the item. + +I can get its name. + +I get its value. + +I can get its weight. + +And I can print it. + +Kind of a boring class, +but useful to have. + +Then, I'm going to use this +class to build items. + +And in this case, I'm going to +build the items based upon + +what we just looked at, +the table that-- + +I think it's in your hand out. + +And it's also on this slide. + +Later, if we want, we can have +a randomized program to build + +up a much bigger choice +of items. + +But here, we'll just try the +clock, the painting, the + +radio, the vase, the book, +and the computer. + +Now comes the interesting +part. + +I've written a function, greedy, +that takes three + +arguments-- + +the set of items that I have to +choose from, makes sense, + +the maximum weight the +burglar can carry. + +And there's something called +key function, which is + +defining essentially what I +mean by locally optimal. + +Then, it's quite simple. + +I'm going to sort the items +using the key function. + +Remember, sort has this optional +argument that says, + +what's the ordering? + +So maybe I'll order +it by value. + +Maybe I'll order +it by density. + +Maybe I'll order it by weight. + +I'm going to reverse it, +because I want the most + +valuable first, not the least +valuable, for example. + +And then, I'm going to just +take the first thing on my + +list until I run out of weight, +and then I'm done. + +And I'll return the result +and the total value. + +To make life simple, I'm going +to define some functions. + +These are the functions that +I can use for the ordering. + +Value, which is just return +the value of the item. + +The inverse of the weight, +because I'm thinking, as a + +greedy algorithm, I'll take the + +lightest, not the heaviest. + +And since I'm reversing it, +I want to do the inverse. + +And the density, which +is just the value + +divided by the weight. + +OK, make sense to everybody? + +You with me? + +Speak now, or not. + +And then, we'll test it. + +So again, kind of a theme of +this part of the course. + +As we write these more complex +programs, we tend to have to + +worry about our test +harnesses. + +So I've got a function that +tests the greedy algorithm, + +and then another function that +tests all three greedy + +approaches-- + +the one algorithm with +different functions-- + +and looks at what +our results are. + +So let's run it. + +See what we get. + +Oh, you know what I did? + +Just the same thing +I did last time. + +But this time, I'm going +to be smarter. + +We're going to get rid of this +figure and comment out the + +code that generated it. + +And now, we'll test the +greedy algorithms. + +So we see the items we had to +choose from, which I printed + +using the string function +and items. + +And if I use greedy by value to +fill a knapsack of size 20, + +we see that I end up getting +just the computer if I do + +greedy by value. + +This is for the nerd burglar. + +If I use weight, I +get a different-- + +I get more things, not +surprisingly -- + +but lower value. + +And if I use density, I also +get four things, but four + +different things, and I +get a higher value. + +So I see that I can run these +greedy algorithms. + +I can get an answer. + +But it's not always +the same answer. + +As I said earlier, greedy +by density happens + +to work best here. + +But you shouldn't assume that +will always be the case. + +I'm sure you can all imagine +a different assignment of + +weights and values that would +make greedy by density give + +you a bad answer. + +All right, before we +talk about how good + +these answers are-- + +and we will come back to that +as, in particular, suppose I + +want the best answer-- + +I want to stop for a minute and +talk about the algorithmic + +efficiency of the greedy +algorithm. + +So let's go back and +look at the code. + +And this is why people use +greedy algorithms. + +Actually, there are +two reasons. + +One reason is that they're easy +to program, and that's + +always a good thing. + +And the other is that they are +typically highly efficient. + +So what's the efficiency +of this? + +How would we think about +the efficiency + +of this greedy algorithm? + +What are we looking at here? + +Well, the first thing we have +to ask is, what's the first + +thing it does? + +It sorts the list, right? + +So one thing that governs the +efficiency might be the amount + +of time it takes to sort +the list of items. + +Well, we know how +long that takes. + +Or we can speculate at least. + +And let's assume it does +something like merge sort. + +So what's that term +going to be? + +Order what? + +Len of items times what? + +Log n, right? + +So maybe that's going +to tell us the + +complexity, but maybe not. + +The next thing we have to do is +look at the while loop and + +see how many times are we going +through the while loop. + +What's the worst case? + +Somebody? + +I know I didn't bring any candy +today, but you could + +answer the question anyway. + +Be a sport. + +Do it for free. + +Yeah? + +AUDIENCE: The length +of the items. + +PROFESSOR: Well, we know +this one is bigger. + +So it looks like that's +the complexity, right? + +So we can say, all right, +pretty good. + +Slightly worse than linear in +the length of the items, but + +not bad at all. + +And that's a big attraction +of greedy algorithms. + +They are typically order length +of items, or order + +length of items times the +log of the length. + +So greedy algorithms are usually +very close to linear. + +And that's why we really +like them. + +Why we don't like them is it may +be that the accumulation + +of a sequence of locally optimal +solutions does not + +yield a globally optimal +solution. + +So now, let's ask the question, +suppose that's not + +good enough. + +I have a very demanding thief. + +Or maybe the thief works for +a very demanding person and + +needs to choose the absolute +optimal set. + +Let's think first about how we +formulate that carefully. + +And then, what the complexity +of solving it would be. + +And then, algorithms that +might be useful. + +Again, the important step here, +I think, is not the + +solution to the problem, but the +process used to formulate + +the problem. + +Often, it is the case that once +one has done a careful + +formulation of a problem, it +becomes obvious how to solve + +it, at least in a +brute force way. + +So now, let's look at a +formalization of the 0/1 + +knapsack problem. + +And it's a kind of formalization +we'll use for a + +lot of problems. + +So step one, we'll represent +each item by a pair. + +Because in fact, in deciding +whether or not to take an + +item, we don't care +what its name. + +We don't care if it's a clock, +or a radio, or whatever. + +What matters is what's its value +and what's its weight. + +We'll write W as the maximum +weight that the thief can + +carry, or that can fit +in the knapsack. + +So far, so good. + +Nothing complicated there. + +Now comes the interesting +step. + +We're going to represent +the set of + +available items as a vector. + +We'll call it I. And then we'll +have another vector, V, + +which indicates whether or not +each item in I has been taken. + +So V is a vector. + +And if V_i is equal to +1, that implies I_i-- + +big I sub little i-- + +has been taken, is +in the knapsack. + +Conversely, if V_i is +0, it means I_i + +is not in the knapsack. + +So having formulated the +situation thusly, we can now + +go back to our notion of an +optimization problem as an + +objective function and a set +of constraints to carefully + +state the problem. + +So for the objective function, +we want to maximize the sum of + +V_i times I_i dot value, where +i ranges over the length of + +the vectors. + +So that's the trick +of the 0/1. + +If I don't take it, it's 0. + +So it's 0 times the value. + +If I take it, it's 1 +times the value. + +So this is going to give me the +sum of the values of the + +items I've taken. + +And then, I have this subject +to the constraint. + +And again, we'll +do a summation. + +And it will look very similar. + +V_i times I_i, but this time, +dot weight is less than or + +equal to W. + +Straightforward, but a +useful kind of skill. + +And people do spend a lot +of time on doing that. + +If you've ever used MATLAB, you +know it wants everything + +to be a vector. + +And that's often because a lot +of these problems can be + +nicely formulated in +this kind of way. + +All right, now let's return to +the question of complexity. + +What happens if we implement +this in the most + +straightforward way? + +What would the most +straightforward + +implementation look like? + +Well, we could enumerate all +possibilities and then choose + +the best that meets +the constraint. + +So this would be the obvious +brute force solution to the + +optimization problem. + +Look at all possible +solutions. + +Choose the best one. + +I think you can see immediately +that this is + +guaranteed to give you +the optimal solution. + +Actually, an optimal solution. + +Maybe there's more +than one best. + +But in that case, you can just +choose whichever one you like + +or whichever comes first, +for example. + +The question is, how long +will this take to run? + +Well, we can think about that +by asking the question, how + +big will this set be? + +How many possibilities +are there? + +Well, we can think about that +in a pretty straightforward + +way because if we look at our +formulation, we can ask + +ourselves, how many possible +vectors are there? + +How many vector V's could there +be which shows which + +items were taken and +which weren't? + +And what's the answer to that? + +Well, if we have n items, +how long will V be? + +Length n, right? + +0, 1 for each. + +If we have a vector of 0's and +1''s of length n, how many + +different values can that +vector take on? + +We asked this question before. + +What's the answer? + +Somebody shout it out. + +I've got a vector of length n. + +Every value in the vector +is either a 0 or a 1. + +So maybe it looks something +like this. + +How many possible combinations +of (0, 1)'s are there? + +AUDIENCE: 2 to the n? + +PROFESSOR: 2 to the n. + +Because essentially, this is +a binary number, exactly. + +And so if I had an n-bit binary +number, I can represent + +2 to the n different values. + +And so we see that we have 2 to +the n possible combinations + +to look at if we use a +brute force solution. + +How bad is this? + +Well, if the number of items +is small, it's not so bad. + +And you'll see that, in fact, I +can run this on the example + +we've looked. + +2 to the 5 is not +a huge number. + +Suppose I have a different +number. + +Suppose I have 50 items +to choose from. + +Not a big problem. + +I heard yesterday that the +number of different airfares + +between two cities in the +US is order of 500 -- + +500 different airfares between, + +say, Boston and Chicago. + +So looking at the best there +might be 2 to the 500, kind of + +a bigger number. + +Let's look at 2 to the 50. + +Let's say there were +50 items to choose + +from in this question. + +And let's say for the sake +of argument, it takes a + +microsecond, one millionth +of a second, + +to generate a solution. + +How long will it take to solve +this problem in a brute force + +way for 50 items? + +Who thinks you can do it +in under four seconds? + +How about under four minutes? + +Wow, skeptics. + +Four hours? + +That's a lot of computation. + +Four hours, you're starting +to get some people. + +Four days? + +All right. + +Well, how about four years? + +Still longer, just under +four decades? + +Looking at one choice every +microsecond, it takes you + +roughly 36 years to evaluate +all these possibilities. + +Certainly for people of my age, +that's not a practical + +solution to have to wait +36 years for an answer. + +So we have to find +something better. + +And we'll be talking +about that later. \ No newline at end of file diff --git a/BcVzc6IGwS0.txt b/BcVzc6IGwS0.txt new file mode 100644 index 0000000000000000000000000000000000000000..0d6cb2bd95ca6c11f553f5cec7506c84312c0761 --- /dev/null +++ b/BcVzc6IGwS0.txt @@ -0,0 +1,15995 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu and I think we're about + + align:start position:0% +ocw.mit.edu and I think we're about + + + align:start position:0% +ocw.mit.edu and I think we're about +ready to get started uh so welcome folks + + align:start position:0% +ready to get started uh so welcome folks + + + align:start position:0% +ready to get started uh so welcome folks +for lecture number two uh of + + align:start position:0% +for lecture number two uh of + + + align:start position:0% +for lecture number two uh of +fundamentals affordable takes focused on + + align:start position:0% +fundamentals affordable takes focused on + + + align:start position:0% +fundamentals affordable takes focused on +the solar resource what I wanted to do + + align:start position:0% +the solar resource what I wanted to do + + + align:start position:0% +the solar resource what I wanted to do +to get everybody in the mood of thinking + + align:start position:0% +to get everybody in the mood of thinking + + + align:start position:0% +to get everybody in the mood of thinking +about the sun is pass around a few balls + + align:start position:0% +about the sun is pass around a few balls + + + align:start position:0% +about the sun is pass around a few balls +so um this is really a to limber you all + + align:start position:0% +so um this is really a to limber you all + + + align:start position:0% +so um this is really a to limber you all +up um but + + align:start position:0% +up um but + + + align:start position:0% +up um but +B There we go all right don't don't + + align:start position:0% +B There we go all right don't don't + + + align:start position:0% +B There we go all right don't don't +don't let it fall there you go I know + + align:start position:0% +don't let it fall there you go I know + + + align:start position:0% +don't let it fall there you go I know +Ashley's got solid hands all right + + align:start position:0% +Ashley's got solid hands all right + + + align:start position:0% +Ashley's got solid hands all right +here's one pass that around as well got + + align:start position:0% +here's one pass that around as well got + + + align:start position:0% +here's one pass that around as well got +a few more there there and lastly right + + align:start position:0% +a few more there there and lastly right + + + align:start position:0% +a few more there there and lastly right +up the middle there you go okay so um + + align:start position:0% +up the middle there you go okay so um + + + align:start position:0% +up the middle there you go okay so um +the the today's lecture is really about + + align:start position:0% +the the today's lecture is really about + + + align:start position:0% +the the today's lecture is really about +the solar resource and as we go through + + align:start position:0% +the solar resource and as we go through + + + align:start position:0% +the solar resource and as we go through +it kind of helps to have a sphere in + + align:start position:0% +it kind of helps to have a sphere in + + + align:start position:0% +it kind of helps to have a sphere in +your hand since um often times we + + align:start position:0% +your hand since um often times we + + + align:start position:0% +your hand since um often times we +perceive the world as being flat um not + + align:start position:0% +perceive the world as being flat um not + + + align:start position:0% +perceive the world as being flat um not +no fault of our own uh locally one can + + align:start position:0% +no fault of our own uh locally one can + + + align:start position:0% +no fault of our own uh locally one can +approximate it as a a flat body uh + + align:start position:0% +approximate it as a a flat body uh + + + align:start position:0% +approximate it as a a flat body uh +that's certainly a a good possibility + + align:start position:0% +that's certainly a a good possibility + + + align:start position:0% +that's certainly a a good possibility +wouldn't mind passing these out to your + + align:start position:0% +wouldn't mind passing these out to your + + + align:start position:0% +wouldn't mind passing these out to your +friends as well thanks um but in reality + + align:start position:0% +friends as well thanks um but in reality + + + align:start position:0% +friends as well thanks um but in reality +if we really want to understand the + + align:start position:0% +if we really want to understand the + + + align:start position:0% +if we really want to understand the +solar resource we really have to begin + + align:start position:0% +solar resource we really have to begin + + + align:start position:0% +solar resource we really have to begin +understanding or thinking in terms of + + align:start position:0% +understanding or thinking in terms of + + + align:start position:0% +understanding or thinking in terms of +spheres and in terms of uh circles or in + + align:start position:0% +spheres and in terms of uh circles or in + + + align:start position:0% +spheres and in terms of uh circles or in +in most cases ellipses uh and so we're + + align:start position:0% +in most cases ellipses uh and so we're + + + align:start position:0% +in most cases ellipses uh and so we're +we're going to dive into the solar + + align:start position:0% +we're going to dive into the solar + + + align:start position:0% +we're going to dive into the solar +resource um before we really dive in in + + align:start position:0% +resource um before we really dive in in + + + align:start position:0% +resource um before we really dive in in +detail into the solar resource I wanted + + align:start position:0% +detail into the solar resource I wanted + + + align:start position:0% +detail into the solar resource I wanted +to give you feedback to your surveys so + + align:start position:0% +to give you feedback to your surveys so + + + align:start position:0% +to give you feedback to your surveys so +you did a background assessment survey a + + align:start position:0% +you did a background assessment survey a + + + align:start position:0% +you did a background assessment survey a +census if you will uh and filled out a + + align:start position:0% +census if you will uh and filled out a + + + align:start position:0% +census if you will uh and filled out a +number of questions last class about + + align:start position:0% +number of questions last class about + + + align:start position:0% +number of questions last class about +your backgrounds and I wanted to provide + + align:start position:0% +your backgrounds and I wanted to provide + + + align:start position:0% +your backgrounds and I wanted to provide +you the feedback the cons the + + align:start position:0% +you the feedback the cons the + + + align:start position:0% +you the feedback the cons the +Consolidated information because it's + + align:start position:0% +Consolidated information because it's + + + align:start position:0% +Consolidated information because it's +really telling about who your colleagues + + align:start position:0% +really telling about who your colleagues + + + align:start position:0% +really telling about who your colleagues +are um this right here is a little bit + + align:start position:0% +are um this right here is a little bit + + + align:start position:0% +are um this right here is a little bit +of a snapshot of expertise and current + + align:start position:0% +of a snapshot of expertise and current + + + align:start position:0% +of a snapshot of expertise and current +uh career trajectory so the self-defined + + align:start position:0% +uh career trajectory so the self-defined + + + align:start position:0% +uh career trajectory so the self-defined +expertise in the bottom left is really I + + align:start position:0% +expertise in the bottom left is really I + + + align:start position:0% +expertise in the bottom left is really I +think the most telling parameter um for + + align:start position:0% +think the most telling parameter um for + + + align:start position:0% +think the most telling parameter um for +the undergrads here uh you may Define + + align:start position:0% +the undergrads here uh you may Define + + + align:start position:0% +the undergrads here uh you may Define +Yourself by your major today but when + + align:start position:0% +Yourself by your major today but when + + + align:start position:0% +Yourself by your major today but when +you graduate and go on to grad school + + align:start position:0% +you graduate and go on to grad school + + + align:start position:0% +you graduate and go on to grad school +you might say for example do your + + align:start position:0% +you might say for example do your + + + align:start position:0% +you might say for example do your +undergrad in physics and then do your + + align:start position:0% +undergrad in physics and then do your + + + align:start position:0% +undergrad in physics and then do your +graduate school in mechanical + + align:start position:0% +graduate school in mechanical + + + align:start position:0% +graduate school in mechanical +engineering but still consider yourself + + align:start position:0% +engineering but still consider yourself + + + align:start position:0% +engineering but still consider yourself +a physicist at heart and so that's why I + + align:start position:0% +a physicist at heart and so that's why I + + + align:start position:0% +a physicist at heart and so that's why I +ask this question here what is your + + align:start position:0% +ask this question here what is your + + + align:start position:0% +ask this question here what is your +self-defined expertise because there are + + align:start position:0% +self-defined expertise because there are + + + align:start position:0% +self-defined expertise because there are +several graduate students have changed + + align:start position:0% +several graduate students have changed + + + align:start position:0% +several graduate students have changed +Fields if you will from undergrad to + + align:start position:0% +Fields if you will from undergrad to + + + align:start position:0% +Fields if you will from undergrad to +graduate school most people in the + + align:start position:0% +graduate school most people in the + + + align:start position:0% +graduate school most people in the +audience uh by and large consider + + align:start position:0% +audience uh by and large consider + + + align:start position:0% +audience uh by and large consider +themselves Engineers um either Material + + align:start position:0% +themselves Engineers um either Material + + + align:start position:0% +themselves Engineers um either Material +Science Engineers or mechanical + + align:start position:0% +Science Engineers or mechanical + + + align:start position:0% +Science Engineers or mechanical +engineers uh chemistry is is uh strong + + align:start position:0% +engineers uh chemistry is is uh strong + + + align:start position:0% +engineers uh chemistry is is uh strong +as well and then we have about well + + align:start position:0% +as well and then we have about well + + + align:start position:0% +as well and then we have about well +about 10 different departments here + + align:start position:0% +about 10 different departments here + + + align:start position:0% +about 10 different departments here +represented um and that's really cool + + align:start position:0% +represented um and that's really cool + + + align:start position:0% +represented um and that's really cool +it's going to uh manifest itself in the + + align:start position:0% +it's going to uh manifest itself in the + + + align:start position:0% +it's going to uh manifest itself in the +class projects and you'll see the + + align:start position:0% +class projects and you'll see the + + + align:start position:0% +class projects and you'll see the +diversity of different inputs and + + align:start position:0% +diversity of different inputs and + + + align:start position:0% +diversity of different inputs and +perspectives from your colleagues the + + align:start position:0% +perspectives from your colleagues the + + + align:start position:0% +perspectives from your colleagues the +degree in progress undergrad grad is + + align:start position:0% +degree in progress undergrad grad is + + + align:start position:0% +degree in progress undergrad grad is +about split uh uh uh 1/3 2/3 grad and + + align:start position:0% +about split uh uh uh 1/3 2/3 grad and + + + align:start position:0% +about split uh uh uh 1/3 2/3 grad and +undergrad and grad ASP is Advanced + + align:start position:0% +undergrad and grad ASP is Advanced + + + align:start position:0% +undergrad and grad ASP is Advanced +Studies program so these are folks + + align:start position:0% +Studies program so these are folks + + + align:start position:0% +Studies program so these are folks +coming in from industry who are actually + + align:start position:0% +coming in from industry who are actually + + + align:start position:0% +coming in from industry who are actually +here in the classroom some of your + + align:start position:0% +here in the classroom some of your + + + align:start position:0% +here in the classroom some of your +colleagues in the class are folks who + + align:start position:0% +colleagues in the class are folks who + + + align:start position:0% +colleagues in the class are folks who +are in industry and perhaps have uh real + + align:start position:0% +are in industry and perhaps have uh real + + + align:start position:0% +are in industry and perhaps have uh real +world uh PV experience several of the + + align:start position:0% +world uh PV experience several of the + + + align:start position:0% +world uh PV experience several of the +people here in the class as well have + + align:start position:0% +people here in the class as well have + + + align:start position:0% +people here in the class as well have +either um have gained um uh how we say + + align:start position:0% +either um have gained um uh how we say + + + align:start position:0% +either um have gained um uh how we say +have gained expertise in solar with + + align:start position:0% +have gained expertise in solar with + + + align:start position:0% +have gained expertise in solar with +their Hobbies with their work some have + + align:start position:0% +their Hobbies with their work some have + + + align:start position:0% +their Hobbies with their work some have +installed solar panels other ones have + + align:start position:0% +installed solar panels other ones have + + + align:start position:0% +installed solar panels other ones have +done research or are doing research in + + align:start position:0% +done research or are doing research in + + + align:start position:0% +done research or are doing research in +solar so it's a pretty diverse group and + + align:start position:0% +solar so it's a pretty diverse group and + + + align:start position:0% +solar so it's a pretty diverse group and +some are as well members of the solar + + align:start position:0% +some are as well members of the solar + + + align:start position:0% +some are as well members of the solar +car team which is rolling out its new + + align:start position:0% +car team which is rolling out its new + + + align:start position:0% +car team which is rolling out its new +model if few days time um in terms of + + align:start position:0% +model if few days time um in terms of + + + align:start position:0% +model if few days time um in terms of +learning methods uh it was pretty well + + align:start position:0% +learning methods uh it was pretty well + + + align:start position:0% +learning methods uh it was pretty well +split um between Hands-On Labs field + + align:start position:0% +split um between Hands-On Labs field + + + align:start position:0% +split um between Hands-On Labs field +trips and guest lectures uh and I'll get + + align:start position:0% +trips and guest lectures uh and I'll get + + + align:start position:0% +trips and guest lectures uh and I'll get +back to that in a few slides um in terms + + align:start position:0% +back to that in a few slides um in terms + + + align:start position:0% +back to that in a few slides um in terms +of class project interest there was a + + align:start position:0% +of class project interest there was a + + + align:start position:0% +of class project interest there was a +strong interest in working with + + align:start position:0% +strong interest in working with + + + align:start position:0% +strong interest in working with +pre-established projects so we've + + align:start position:0% +pre-established projects so we've + + + align:start position:0% +pre-established projects so we've +listened to that um this is pretty + + align:start position:0% +listened to that um this is pretty + + + align:start position:0% +listened to that um this is pretty +consistent with previous years and so we + + align:start position:0% +consistent with previous years and so we + + + align:start position:0% +consistent with previous years and so we +have several pre-prepared class projects + + align:start position:0% +have several pre-prepared class projects + + + align:start position:0% +have several pre-prepared class projects +ready for you um and a few of you had an + + align:start position:0% +ready for you um and a few of you had an + + + align:start position:0% +ready for you um and a few of you had an +interest in the self-design project I'd + + align:start position:0% +interest in the self-design project I'd + + + align:start position:0% +interest in the self-design project I'd +like to talk to you I'd like to begin + + align:start position:0% +like to talk to you I'd like to begin + + + align:start position:0% +like to talk to you I'd like to begin +developing those ideas as soon as + + align:start position:0% +developing those ideas as soon as + + + align:start position:0% +developing those ideas as soon as +possible possible uh so that um when we + + align:start position:0% +possible possible uh so that um when we + + + align:start position:0% +possible possible uh so that um when we +start assembling teams uh if you do have + + align:start position:0% +start assembling teams uh if you do have + + + align:start position:0% +start assembling teams uh if you do have +a strong idea for a class project we can + + align:start position:0% +a strong idea for a class project we can + + + align:start position:0% +a strong idea for a class project we can +begin crafting that and molding that uh + + align:start position:0% +begin crafting that and molding that uh + + + align:start position:0% +begin crafting that and molding that uh +starting now so please come up and have + + align:start position:0% +starting now so please come up and have + + + align:start position:0% +starting now so please come up and have +a chat with me after class or during + + align:start position:0% +a chat with me after class or during + + + align:start position:0% +a chat with me after class or during +office hours or during + + align:start position:0% +office hours or during + + + align:start position:0% +office hours or during +recitation um these are your learning + + align:start position:0% +recitation um these are your learning + + + align:start position:0% +recitation um these are your learning +objectives um defined by you um and they + + align:start position:0% +objectives um defined by you um and they + + + align:start position:0% +objectives um defined by you um and they +range I tried to give it some uh + + align:start position:0% +range I tried to give it some uh + + + align:start position:0% +range I tried to give it some uh +Continuum Spectrum from Natural Sciences + + align:start position:0% +Continuum Spectrum from Natural Sciences + + + align:start position:0% +Continuum Spectrum from Natural Sciences +to social sciences and Engineering in + + align:start position:0% +to social sciences and Engineering in + + + align:start position:0% +to social sciences and Engineering in +the middle and uh obviously this is more + + align:start position:0% +the middle and uh obviously this is more + + + align:start position:0% +the middle and uh obviously this is more +of a a loop than a than a a linear uh + + align:start position:0% +of a a loop than a than a a linear uh + + + align:start position:0% +of a a loop than a than a a linear uh +line but um bear with me there was a + + align:start position:0% +line but um bear with me there was a + + + align:start position:0% +line but um bear with me there was a +strong interest in fundamentals and + + align:start position:0% +strong interest in fundamentals and + + + align:start position:0% +strong interest in fundamentals and +that's certainly I think what the core + + align:start position:0% +that's certainly I think what the core + + + align:start position:0% +that's certainly I think what the core +of the class is about at least the first + + align:start position:0% +of the class is about at least the first + + + align:start position:0% +of the class is about at least the first +third of the class um going in terms of + + align:start position:0% +third of the class um going in terms of + + + align:start position:0% +third of the class um going in terms of +size of the bubble these are the number + + align:start position:0% +size of the bubble these are the number + + + align:start position:0% +size of the bubble these are the number +of people who listed a particular topic + + align:start position:0% +of people who listed a particular topic + + + align:start position:0% +of people who listed a particular topic +as of great interest to them uh + + align:start position:0% +as of great interest to them uh + + + align:start position:0% +as of great interest to them uh +economics and Market systems and grid + + align:start position:0% +economics and Market systems and grid + + + align:start position:0% +economics and Market systems and grid +current Technologies emerging + + align:start position:0% +current Technologies emerging + + + align:start position:0% +current Technologies emerging +Technologies and so listening to all of + + align:start position:0% +Technologies and so listening to all of + + + align:start position:0% +Technologies and so listening to all of +this we have or we are in the process of + + align:start position:0% +this we have or we are in the process of + + + align:start position:0% +this we have or we are in the process of +preparing for you some guest lectures + + align:start position:0% +preparing for you some guest lectures + + + align:start position:0% +preparing for you some guest lectures +and field trips based on this feedback + + align:start position:0% +and field trips based on this feedback + + + align:start position:0% +and field trips based on this feedback +right here we have already lined up a a + + align:start position:0% +right here we have already lined up a a + + + align:start position:0% +right here we have already lined up a a +field trip to a local uh PV uh research + + align:start position:0% +field trip to a local uh PV uh research + + + align:start position:0% +field trip to a local uh PV uh research +laboratory that uh produces modules uh + + align:start position:0% +laboratory that uh produces modules uh + + + align:start position:0% +laboratory that uh produces modules uh +like this one right here only much much + + align:start position:0% +like this one right here only much much + + + align:start position:0% +like this one right here only much much +bigger and has strong uh collaboration + + align:start position:0% +bigger and has strong uh collaboration + + + align:start position:0% +bigger and has strong uh collaboration +with existing companies startup + + align:start position:0% +with existing companies startup + + + align:start position:0% +with existing companies startup +companies in the area as well as more + + align:start position:0% +companies in the area as well as more + + + align:start position:0% +companies in the area as well as more +established companies so that'll be a + + align:start position:0% +established companies so that'll be a + + + align:start position:0% +established companies so that'll be a +lot of fun um and we're currently in the + + align:start position:0% +lot of fun um and we're currently in the + + + align:start position:0% +lot of fun um and we're currently in the +process of arranging other field trips + + align:start position:0% +process of arranging other field trips + + + align:start position:0% +process of arranging other field trips +and guest lectures to match uh this uh + + align:start position:0% +and guest lectures to match uh this uh + + + align:start position:0% +and guest lectures to match uh this uh +feedback right here so thank you we'll + + align:start position:0% +feedback right here so thank you we'll + + + align:start position:0% +feedback right here so thank you we'll +mold the course mold the course shape it + + align:start position:0% +mold the course mold the course shape it + + + align:start position:0% +mold the course mold the course shape it +crafted uh to fit your your + + align:start position:0% +crafted uh to fit your your + + + align:start position:0% +crafted uh to fit your your +interests so uh to hop into the solar + + align:start position:0% +interests so uh to hop into the solar + + + align:start position:0% +interests so uh to hop into the solar +resource and uh without further Ado uh + + align:start position:0% +resource and uh without further Ado uh + + + align:start position:0% +resource and uh without further Ado uh +the subject of today and the motivation + + align:start position:0% +the subject of today and the motivation + + + align:start position:0% +the subject of today and the motivation +for wearing this tie is really the solar + + align:start position:0% +for wearing this tie is really the solar + + + align:start position:0% +for wearing this tie is really the solar +resource the sun uh this is where it all + + align:start position:0% +resource the sun uh this is where it all + + + align:start position:0% +resource the sun uh this is where it all +starts if we're to understand PV + + align:start position:0% +starts if we're to understand PV + + + align:start position:0% +starts if we're to understand PV +photovoltaics the conversion of sunlight + + align:start position:0% +photovoltaics the conversion of sunlight + + + align:start position:0% +photovoltaics the conversion of sunlight +into electricity it starts from the Sun + + align:start position:0% +into electricity it starts from the Sun + + + align:start position:0% +into electricity it starts from the Sun +and so spending some good time thinking + + align:start position:0% +and so spending some good time thinking + + + align:start position:0% +and so spending some good time thinking +about the sun is really really important + + align:start position:0% +about the sun is really really important + + + align:start position:0% +about the sun is really really important +and it will avoid the embarrassing + + align:start position:0% +and it will avoid the embarrassing + + + align:start position:0% +and it will avoid the embarrassing +situation how many of you have been at a + + align:start position:0% +situation how many of you have been at a + + + align:start position:0% +situation how many of you have been at a +shopping center walking along and a + + align:start position:0% +shopping center walking along and a + + + align:start position:0% +shopping center walking along and a +little child is asking his parent uh dad + + align:start position:0% +little child is asking his parent uh dad + + + align:start position:0% +little child is asking his parent uh dad +why why is the sky blue or why is such + + align:start position:0% +why why is the sky blue or why is such + + + align:start position:0% +why why is the sky blue or why is such +and such and the answers you'll hear + + align:start position:0% +and such and the answers you'll hear + + + align:start position:0% +and such and the answers you'll hear +just make you want to tear your ears out + + align:start position:0% +just make you want to tear your ears out + + + align:start position:0% +just make you want to tear your ears out +um and say my goodness so part of this + + align:start position:0% +um and say my goodness so part of this + + + align:start position:0% +um and say my goodness so part of this +is is just general knowledge it's + + align:start position:0% +is is just general knowledge it's + + + align:start position:0% +is is just general knowledge it's +getting a feel for the world and the + + align:start position:0% +getting a feel for the world and the + + + align:start position:0% +getting a feel for the world and the +universe and asking those questions + + align:start position:0% +universe and asking those questions + + + align:start position:0% +universe and asking those questions +again that the little children will ask + + align:start position:0% +again that the little children will ask + + + align:start position:0% +again that the little children will ask +but that we forget to ask as we move on + + align:start position:0% +but that we forget to ask as we move on + + + align:start position:0% +but that we forget to ask as we move on +with our lives right okay so moving + + align:start position:0% +with our lives right okay so moving + + + align:start position:0% +with our lives right okay so moving +forward um the learning objectives for + + align:start position:0% +forward um the learning objectives for + + + align:start position:0% +forward um the learning objectives for +today are these right here by the end of + + align:start position:0% +today are these right here by the end of + + + align:start position:0% +today are these right here by the end of +the lecture and hopefully you already + + align:start position:0% +the lecture and hopefully you already + + + align:start position:0% +the lecture and hopefully you already +have a good sense of this based on your + + align:start position:0% +have a good sense of this based on your + + + align:start position:0% +have a good sense of this based on your +readings already I'll quiz you on that + + align:start position:0% +readings already I'll quiz you on that + + + align:start position:0% +readings already I'll quiz you on that +in a second verbally um we want to be + + align:start position:0% +in a second verbally um we want to be + + + align:start position:0% +in a second verbally um we want to be +able to quantify the available solar + + align:start position:0% +able to quantify the available solar + + + align:start position:0% +able to quantify the available solar +resource relative to human energy needs + + align:start position:0% +resource relative to human energy needs + + + align:start position:0% +resource relative to human energy needs +and other fossil other fuel sources we + + align:start position:0% +and other fossil other fuel sources we + + + align:start position:0% +and other fossil other fuel sources we +want to recognize and plot uh air mass Z + + align:start position:0% +want to recognize and plot uh air mass Z + + + align:start position:0% +want to recognize and plot uh air mass Z +and air mass 1.5 solar Spectra and + + align:start position:0% +and air mass 1.5 solar Spectra and + + + align:start position:0% +and air mass 1.5 solar Spectra and +describe the physical Origins we want to + + align:start position:0% +describe the physical Origins we want to + + + align:start position:0% +describe the physical Origins we want to +describe how solar insulation Maps these + + align:start position:0% +describe how solar insulation Maps these + + + align:start position:0% +describe how solar insulation Maps these +are solar resource maps in other words + + align:start position:0% +are solar resource maps in other words + + + align:start position:0% +are solar resource maps in other words +how much sunlight is available and we + + align:start position:0% +how much sunlight is available and we + + + align:start position:0% +how much sunlight is available and we +want to be able to estimate uh a solar + + align:start position:0% +want to be able to estimate uh a solar + + + align:start position:0% +want to be able to estimate uh a solar +uh resource uh amount locally at a + + align:start position:0% +uh resource uh amount locally at a + + + align:start position:0% +uh resource uh amount locally at a +specific spot in the planet we want to + + align:start position:0% +specific spot in the planet we want to + + + align:start position:0% +specific spot in the planet we want to +list the causes of variation and + + align:start position:0% +list the causes of variation and + + + align:start position:0% +list the causes of variation and +intermittency of solar of the solar + + align:start position:0% +intermittency of solar of the solar + + + align:start position:0% +intermittency of solar of the solar +resource and Quant if their time + + align:start position:0% +resource and Quant if their time + + + align:start position:0% +resource and Quant if their time +constant and magnitude in other words we + + align:start position:0% +constant and magnitude in other words we + + + align:start position:0% +constant and magnitude in other words we +want to be able to discern what are the + + align:start position:0% +want to be able to discern what are the + + + align:start position:0% +want to be able to discern what are the +big effects and what are the ones that + + align:start position:0% +big effects and what are the ones that + + + align:start position:0% +big effects and what are the ones that +don't really matter we want to be able + + align:start position:0% +don't really matter we want to be able + + + align:start position:0% +don't really matter we want to be able +to estimate the land area needed to + + align:start position:0% +to estimate the land area needed to + + + align:start position:0% +to estimate the land area needed to +provide sufficient solar resource for a + + align:start position:0% +provide sufficient solar resource for a + + + align:start position:0% +provide sufficient solar resource for a +project whether it's a house a car + + align:start position:0% +project whether it's a house a car + + + align:start position:0% +project whether it's a house a car +Village country World um and a lot of + + align:start position:0% +Village country World um and a lot of + + + align:start position:0% +Village country World um and a lot of +this will be on your homework assignment + + align:start position:0% +this will be on your homework assignment + + + align:start position:0% +this will be on your homework assignment +so we'll give you the tools here uh but + + align:start position:0% +so we'll give you the tools here uh but + + + align:start position:0% +so we'll give you the tools here uh but +then ask you to address those questions + + align:start position:0% +then ask you to address those questions + + + align:start position:0% +then ask you to address those questions +and for those of you who have already + + align:start position:0% +and for those of you who have already + + + align:start position:0% +and for those of you who have already +picked up your P set number one you'll + + align:start position:0% +picked up your P set number one you'll + + + align:start position:0% +picked up your P set number one you'll +see relevant questions where's + + align:start position:0% + + + + align:start position:0% + +this do anybody body recognize this + + align:start position:0% +this do anybody body recognize this + + + align:start position:0% +this do anybody body recognize this +right here if I start rambling off + + align:start position:0% +right here if I start rambling off + + + align:start position:0% +right here if I start rambling off +names what city has Pennsylvania Avenue + + align:start position:0% +names what city has Pennsylvania Avenue + + + align:start position:0% +names what city has Pennsylvania Avenue +independent AV Washington DC this is + + align:start position:0% +independent AV Washington DC this is + + + align:start position:0% +independent AV Washington DC this is +right outside of the National Air and + + align:start position:0% +right outside of the National Air and + + + align:start position:0% +right outside of the National Air and +Space Museum uh what this little uh girl + + align:start position:0% +Space Museum uh what this little uh girl + + + align:start position:0% +Space Museum uh what this little uh girl +here is is pointing to is the sun uh and + + align:start position:0% +here is is pointing to is the sun uh and + + + align:start position:0% +here is is pointing to is the sun uh and +then we have mercury uh Venus Earth Mars + + align:start position:0% +then we have mercury uh Venus Earth Mars + + + align:start position:0% +then we have mercury uh Venus Earth Mars +and so forth so it's a essentially a + + align:start position:0% +and so forth so it's a essentially a + + + align:start position:0% +and so forth so it's a essentially a +solar system to scale as you walk out of + + align:start position:0% +solar system to scale as you walk out of + + + align:start position:0% +solar system to scale as you walk out of +the uh of the air and space museum and + + align:start position:0% +the uh of the air and space museum and + + + align:start position:0% +the uh of the air and space museum and +walk down the street you'll be passing + + align:start position:0% +walk down the street you'll be passing + + + align:start position:0% +walk down the street you'll be passing +the different bodies in our solar system + + align:start position:0% +the different bodies in our solar system + + + align:start position:0% +the different bodies in our solar system +and so uh just as a quick little review + + align:start position:0% +and so uh just as a quick little review + + + align:start position:0% +and so uh just as a quick little review +to to kind of get us situated and to ask + + align:start position:0% +to to kind of get us situated and to ask + + + align:start position:0% +to to kind of get us situated and to ask +the questions that little kitties might + + align:start position:0% +the questions that little kitties might + + + align:start position:0% +the questions that little kitties might +ask us uh how far is it from the Earth + + align:start position:0% +ask us uh how far is it from the Earth + + + align:start position:0% +ask us uh how far is it from the Earth +to the + + align:start position:0% + + + + align:start position:0% + +sun about 100 million miles yeah 93 + + align:start position:0% +sun about 100 million miles yeah 93 + + + align:start position:0% +sun about 100 million miles yeah 93 +million miles um plus or minus somewhere + + align:start position:0% +million miles um plus or minus somewhere + + + align:start position:0% +million miles um plus or minus somewhere +in the range of maybe a percent or so a + + align:start position:0% +in the range of maybe a percent or so a + + + align:start position:0% +in the range of maybe a percent or so a +few percent uh uh depending on what time + + align:start position:0% +few percent uh uh depending on what time + + + align:start position:0% +few percent uh uh depending on what time +of year we are because we're in a little + + align:start position:0% +of year we are because we're in a little + + + align:start position:0% +of year we are because we're in a little +bit of an elliptical orbit good so um + + align:start position:0% +bit of an elliptical orbit good so um + + + align:start position:0% +bit of an elliptical orbit good so um +that's uh the distance to the Sun it' be + + align:start position:0% +that's uh the distance to the Sun it' be + + + align:start position:0% +that's uh the distance to the Sun it' be +about 150 million kilometers how long + + align:start position:0% +about 150 million kilometers how long + + + align:start position:0% +about 150 million kilometers how long +does it take light to travel that + + align:start position:0% +does it take light to travel that + + + align:start position:0% +does it take light to travel that +distance about 8 minutes 8 and the third + + align:start position:0% +distance about 8 minutes 8 and the third + + + align:start position:0% +distance about 8 minutes 8 and the third +minutes right so it's uh it takes a + + align:start position:0% +minutes right so it's uh it takes a + + + align:start position:0% +minutes right so it's uh it takes a +little bit for the light to reach us + + align:start position:0% +little bit for the light to reach us + + + align:start position:0% +little bit for the light to reach us +good um some more questions how far are + + align:start position:0% +good um some more questions how far are + + + align:start position:0% +good um some more questions how far are +the other planets in our solar system to + + align:start position:0% +the other planets in our solar system to + + + align:start position:0% +the other planets in our solar system to +the sun just going in order from Mercury + + align:start position:0% +the sun just going in order from Mercury + + + align:start position:0% +the sun just going in order from Mercury +out just to get us situated here if if + + align:start position:0% +out just to get us situated here if if + + + align:start position:0% +out just to get us situated here if if +we are at any point planning and + + align:start position:0% +we are at any point planning and + + + align:start position:0% +we are at any point planning and +throwing up satellites and sending into + + align:start position:0% +throwing up satellites and sending into + + + align:start position:0% +throwing up satellites and sending into +other planets this is a good thing to + + align:start position:0% +other planets this is a good thing to + + + align:start position:0% +other planets this is a good thing to +kind of keep in the back of our + + align:start position:0% +kind of keep in the back of our + + + align:start position:0% +kind of keep in the back of our +minds so if we Define an astronomical + + align:start position:0% +minds so if we Define an astronomical + + + align:start position:0% +minds so if we Define an astronomical +unit not in terms of our national debt + + align:start position:0% +unit not in terms of our national debt + + + align:start position:0% +unit not in terms of our national debt +but in terms of the distance from the + + align:start position:0% +but in terms of the distance from the + + + align:start position:0% +but in terms of the distance from the +Earth to the sun um that's an + + align:start position:0% +Earth to the sun um that's an + + + align:start position:0% +Earth to the sun um that's an +astronomical unit um Mercury would be + + align:start position:0% +astronomical unit um Mercury would be + + + align:start position:0% +astronomical unit um Mercury would be +somewhere + + align:start position:0% +somewhere + + + align:start position:0% +somewhere +around4 Venus 7 Mars 1.5 so that's all + + align:start position:0% +around4 Venus 7 Mars 1.5 so that's all + + + align:start position:0% +around4 Venus 7 Mars 1.5 so that's all +kind of in our neighborhood right and + + align:start position:0% +kind of in our neighborhood right and + + + align:start position:0% +kind of in our neighborhood right and +then from Mars to Jupiter there's a bit + + align:start position:0% +then from Mars to Jupiter there's a bit + + + align:start position:0% +then from Mars to Jupiter there's a bit +of a jump goes from 1.5 to 5 then from + + align:start position:0% +of a jump goes from 1.5 to 5 then from + + + align:start position:0% +of a jump goes from 1.5 to 5 then from +Jupiter to Saturn it's 10 well sorry 10 + + align:start position:0% +Jupiter to Saturn it's 10 well sorry 10 + + + align:start position:0% +Jupiter to Saturn it's 10 well sorry 10 +is the distance from Saturn to the Sun + + align:start position:0% +is the distance from Saturn to the Sun + + + align:start position:0% +is the distance from Saturn to the Sun +and then third and 40 sorry 10 20 30 40 + + align:start position:0% +and then third and 40 sorry 10 20 30 40 + + + align:start position:0% +and then third and 40 sorry 10 20 30 40 +so it goes uh Jupiter is 5 Saturn 10 uh + + align:start position:0% +so it goes uh Jupiter is 5 Saturn 10 uh + + + align:start position:0% +so it goes uh Jupiter is 5 Saturn 10 uh +Uranus would be 20 Neptune 30 Pluto 40 + + align:start position:0% +Uranus would be 20 Neptune 30 Pluto 40 + + + align:start position:0% +Uranus would be 20 Neptune 30 Pluto 40 +right Pluto planet sort of so it's it's + + align:start position:0% +right Pluto planet sort of so it's it's + + + align:start position:0% +right Pluto planet sort of so it's it's +easy to remember those numbers because + + align:start position:0% +easy to remember those numbers because + + + align:start position:0% +easy to remember those numbers because +it goes 5 10 20 that's just essentially + + align:start position:0% +it goes 5 10 20 that's just essentially + + + align:start position:0% +it goes 5 10 20 that's just essentially +a sequence of doubling and then 10 20 30 + + align:start position:0% +a sequence of doubling and then 10 20 30 + + + align:start position:0% +a sequence of doubling and then 10 20 30 +40 I'm giving you approximate numbers + + align:start position:0% +40 I'm giving you approximate numbers + + + align:start position:0% +40 I'm giving you approximate numbers +here but that's uh something just to + + align:start position:0% +here but that's uh something just to + + + align:start position:0% +here but that's uh something just to +keep in mind all in in terms of + + align:start position:0% +keep in mind all in in terms of + + + align:start position:0% +keep in mind all in in terms of +astronomical units so in case a little + + align:start position:0% +astronomical units so in case a little + + + align:start position:0% +astronomical units so in case a little +kid comes up and asks you you can spread + + align:start position:0% +kid comes up and asks you you can spread + + + align:start position:0% +kid comes up and asks you you can spread +out the answer um Let's uh talk about + + align:start position:0% +out the answer um Let's uh talk about + + + align:start position:0% +out the answer um Let's uh talk about +the the the the sun this is just a + + align:start position:0% +the the the the sun this is just a + + + align:start position:0% +the the the the sun this is just a +review of our readings right here um + + align:start position:0% +review of our readings right here um + + + align:start position:0% +review of our readings right here um +this was a representation of the Sun and + + align:start position:0% +this was a representation of the Sun and + + + align:start position:0% +this was a representation of the Sun and +the Earth moving around and um what is + + align:start position:0% +the Earth moving around and um what is + + + align:start position:0% +the Earth moving around and um what is +Solstice and Equinox what do those refer + + align:start position:0% + + + + align:start position:0% + +to what is what is this what is the + + align:start position:0% + + + + align:start position:0% + +equinox yeah equal amount of light and + + align:start position:0% +equinox yeah equal amount of light and + + + align:start position:0% +equinox yeah equal amount of light and +dark throughout uh pretty much all the + + align:start position:0% +dark throughout uh pretty much all the + + + align:start position:0% +dark throughout uh pretty much all the +world except if you're really standing + + align:start position:0% +world except if you're really standing + + + align:start position:0% +world except if you're really standing +on the tippy top in the bottom um so + + align:start position:0% +on the tippy top in the bottom um so + + + align:start position:0% +on the tippy top in the bottom um so +equal amount of light and dark uh + + align:start position:0% +equal amount of light and dark uh + + + align:start position:0% +equal amount of light and dark uh +throughout the world on that particular + + align:start position:0% +throughout the world on that particular + + + align:start position:0% +throughout the world on that particular +day so the the the uh the day and the + + align:start position:0% +day so the the the uh the day and the + + + align:start position:0% +day so the the the uh the day and the +night uh have the same amount of length + + align:start position:0% +night uh have the same amount of length + + + align:start position:0% +night uh have the same amount of length +if you move over into this region right + + align:start position:0% +if you move over into this region right + + + align:start position:0% +if you move over into this region right +here this would be a region of our + + align:start position:0% +here this would be a region of our + + + align:start position:0% +here this would be a region of our +northern hemisphere summer southern + + align:start position:0% +northern hemisphere summer southern + + + align:start position:0% +northern hemisphere summer southern +hemisphere winter over here vice versa + + align:start position:0% +hemisphere winter over here vice versa + + + align:start position:0% +hemisphere winter over here vice versa +and the solstice would + + align:start position:0% + + + + align:start position:0% + +be yeah so the the the shortest um or + + align:start position:0% +be yeah so the the the shortest um or + + + align:start position:0% +be yeah so the the the shortest um or +the longest day of the year depending on + + align:start position:0% +the longest day of the year depending on + + + align:start position:0% +the longest day of the year depending on +what uh side you're on so in the + + align:start position:0% +what uh side you're on so in the + + + align:start position:0% +what uh side you're on so in the +northern hemisphere the uh the June + + align:start position:0% +northern hemisphere the uh the June + + + align:start position:0% +northern hemisphere the uh the June +solstice would be the summer solstice + + align:start position:0% +solstice would be the summer solstice + + + align:start position:0% +solstice would be the summer solstice +for us it would be the longest day and + + align:start position:0% +for us it would be the longest day and + + + align:start position:0% +for us it would be the longest day and +if you're in the southern hemisphere it + + align:start position:0% +if you're in the southern hemisphere it + + + align:start position:0% +if you're in the southern hemisphere it +would be the shortest day depending on + + align:start position:0% +would be the shortest day depending on + + + align:start position:0% +would be the shortest day depending on +what time zone you're in there might be + + align:start position:0% +what time zone you're in there might be + + + align:start position:0% +what time zone you're in there might be +a variation of of one day uh hither to + + align:start position:0% +a variation of of one day uh hither to + + + align:start position:0% +a variation of of one day uh hither to +um good okay and um what is this uh what + + align:start position:0% +um good okay and um what is this uh what + + + align:start position:0% +um good okay and um what is this uh what +are the seasons caused by what is this + + align:start position:0% +are the seasons caused by what is this + + + align:start position:0% +are the seasons caused by what is this +kind of tilt right here what is that + + align:start position:0% +kind of tilt right here what is that + + + align:start position:0% +kind of tilt right here what is that +called declination angle and + + align:start position:0% +called declination angle and + + + align:start position:0% +called declination angle and +approximately how much is + + align:start position:0% +approximately how much is + + + align:start position:0% +approximately how much is +that 232 23.4 yeah so 23 half degrees + + align:start position:0% +that 232 23.4 yeah so 23 half degrees + + + align:start position:0% +that 232 23.4 yeah so 23 half degrees +good okay and we can visualize all of + + align:start position:0% +good okay and we can visualize all of + + + align:start position:0% +good okay and we can visualize all of +this on the pbcd ROM on the website so + + align:start position:0% +this on the pbcd ROM on the website so + + + align:start position:0% +this on the pbcd ROM on the website so +this was part of your signed reading and + + align:start position:0% +this was part of your signed reading and + + + align:start position:0% +this was part of your signed reading and +uh here's the earth going around the Sun + + align:start position:0% +uh here's the earth going around the Sun + + + align:start position:0% +uh here's the earth going around the Sun +in this representation um likewise if + + align:start position:0% +in this representation um likewise if + + + align:start position:0% +in this representation um likewise if +you want to take one of your balls and + + align:start position:0% +you want to take one of your balls and + + + align:start position:0% +you want to take one of your balls and +just kind of Imagine uh being on one of + + align:start position:0% +just kind of Imagine uh being on one of + + + align:start position:0% +just kind of Imagine uh being on one of +those surfaces uh you see the Ural + + align:start position:0% +those surfaces uh you see the Ural + + + align:start position:0% +those surfaces uh you see the Ural +rotation here it's spinning around its + + align:start position:0% +rotation here it's spinning around its + + + align:start position:0% +rotation here it's spinning around its +axis and as well the uh seasonal + + align:start position:0% +axis and as well the uh seasonal + + + align:start position:0% +axis and as well the uh seasonal +variation as it uh spins around the Sun + + align:start position:0% +variation as it uh spins around the Sun + + + align:start position:0% +variation as it uh spins around the Sun +um that's important for a number of + + align:start position:0% +um that's important for a number of + + + align:start position:0% +um that's important for a number of +reasons right uh that will will + + align:start position:0% +reasons right uh that will will + + + align:start position:0% +reasons right uh that will will +determine uh how much sunlight is + + align:start position:0% +determine uh how much sunlight is + + + align:start position:0% +determine uh how much sunlight is +normally incident on the planet um if + + align:start position:0% +normally incident on the planet um if + + + align:start position:0% +normally incident on the planet um if +you are normally incident if you're at + + align:start position:0% +you are normally incident if you're at + + + align:start position:0% +you are normally incident if you're at +this exact spot right here you're + + align:start position:0% +this exact spot right here you're + + + align:start position:0% +this exact spot right here you're +receiving the sunlight full on but if + + align:start position:0% +receiving the sunlight full on but if + + + align:start position:0% +receiving the sunlight full on but if +you're up here somewhere right your your + + align:start position:0% +you're up here somewhere right your your + + + align:start position:0% +you're up here somewhere right your your +surface normal is pointing some Vector + + align:start position:0% +surface normal is pointing some Vector + + + align:start position:0% +surface normal is pointing some Vector +pointing out like that you're only going + + align:start position:0% +pointing out like that you're only going + + + align:start position:0% +pointing out like that you're only going +to be receiving the cosine Theta of that + + align:start position:0% +to be receiving the cosine Theta of that + + + align:start position:0% +to be receiving the cosine Theta of that +amount of sun right so if you're if + + align:start position:0% +amount of sun right so if you're if + + + align:start position:0% +amount of sun right so if you're if +you're an extreme example if you're + + align:start position:0% +you're an extreme example if you're + + + align:start position:0% +you're an extreme example if you're +right here you're not going to get any + + align:start position:0% +right here you're not going to get any + + + align:start position:0% +right here you're not going to get any +um but if you're in this part right here + + align:start position:0% +um but if you're in this part right here + + + align:start position:0% +um but if you're in this part right here +you're going to get cosine uh cosine of + + align:start position:0% +you're going to get cosine uh cosine of + + + align:start position:0% +you're going to get cosine uh cosine of +Z which would be one so you get the full + + align:start position:0% +Z which would be one so you get the full + + + align:start position:0% +Z which would be one so you get the full +amount of sun and likewise As you move + + align:start position:0% +amount of sun and likewise As you move + + + align:start position:0% +amount of sun and likewise As you move +through the angles here so it's + + align:start position:0% +through the angles here so it's + + + align:start position:0% +through the angles here so it's +important to understand what the + + align:start position:0% +important to understand what the + + + align:start position:0% +important to understand what the +relative angle is between our surface + + align:start position:0% +relative angle is between our surface + + + align:start position:0% +relative angle is between our surface +normal and the vector pointing at the + + align:start position:0% +normal and the vector pointing at the + + + align:start position:0% +normal and the vector pointing at the +Sun that varies as a function of season + + align:start position:0% +Sun that varies as a function of season + + + align:start position:0% +Sun that varies as a function of season +it varies as a function of time of day + + align:start position:0% +it varies as a function of time of day + + + align:start position:0% +it varies as a function of time of day +and obviously over the entire Earth uh + + align:start position:0% +and obviously over the entire Earth uh + + + align:start position:0% +and obviously over the entire Earth uh +you can Define uh the precise uh amount + + align:start position:0% +you can Define uh the precise uh amount + + + align:start position:0% +you can Define uh the precise uh amount +of sunlight coming in the precise solar + + align:start position:0% +of sunlight coming in the precise solar + + + align:start position:0% +of sunlight coming in the precise solar +resource by a series of trig formula uh + + align:start position:0% +resource by a series of trig formula uh + + + align:start position:0% +resource by a series of trig formula uh +it gets pretty complex and this website + + align:start position:0% +it gets pretty complex and this website + + + align:start position:0% +it gets pretty complex and this website +will actually walk you through it if + + align:start position:0% +will actually walk you through it if + + + align:start position:0% +will actually walk you through it if +you're so interested + + align:start position:0% +you're so interested + + + align:start position:0% +you're so interested +now this is all review since folks have + + align:start position:0% +now this is all review since folks have + + + align:start position:0% +now this is all review since folks have +all done the background reading right + + align:start position:0% +all done the background reading right + + + align:start position:0% +all done the background reading right +all done the background reading expect + + align:start position:0% +all done the background reading expect + + + align:start position:0% +all done the background reading expect +you to before class um let me ask you a + + align:start position:0% +you to before class um let me ask you a + + + align:start position:0% +you to before class um let me ask you a +few trickier questions just to see if + + align:start position:0% +few trickier questions just to see if + + + align:start position:0% +few trickier questions just to see if +our creative juices are really moving at + + align:start position:0% +our creative juices are really moving at + + + align:start position:0% +our creative juices are really moving at +this early time of day when would be the + + align:start position:0% +this early time of day when would be the + + + align:start position:0% +this early time of day when would be the +the the shortest day of the year let's + + align:start position:0% +the the shortest day of the year let's + + + align:start position:0% +the the shortest day of the year let's +start there the shortest day of the year + + align:start position:0% +start there the shortest day of the year + + + align:start position:0% +start there the shortest day of the year +is approximately December 22nd right in + + align:start position:0% +is approximately December 22nd right in + + + align:start position:0% +is approximately December 22nd right in +the CSUS when is the earliest sorry when + + align:start position:0% +the CSUS when is the earliest sorry when + + + align:start position:0% +the CSUS when is the earliest sorry when +is the latest sunrise and when is the + + align:start position:0% +is the latest sunrise and when is the + + + align:start position:0% +is the latest sunrise and when is the +earliest sunset + + align:start position:0% + + + + align:start position:0% + +said you might need to pick up your + + align:start position:0% +said you might need to pick up your + + + align:start position:0% +said you might need to pick up your +little ball and rotate it + + align:start position:0% + + + + align:start position:0% + +around does anybody have a even a just a + + align:start position:0% +around does anybody have a even a just a + + + align:start position:0% +around does anybody have a even a just a +gut sense would it be on would it be on + + align:start position:0% +gut sense would it be on would it be on + + + align:start position:0% +gut sense would it be on would it be on +the solstice how many people think it's + + align:start position:0% +the solstice how many people think it's + + + align:start position:0% +the solstice how many people think it's +going to be exactly on the solstice + + align:start position:0% +going to be exactly on the solstice + + + align:start position:0% +going to be exactly on the solstice +let's see earliest sunset how many + + align:start position:0% +let's see earliest sunset how many + + + align:start position:0% +let's see earliest sunset how many +people think that the earliest sunset's + + align:start position:0% +people think that the earliest sunset's + + + align:start position:0% +people think that the earliest sunset's +going to be a little bit before the + + align:start position:0% +going to be a little bit before the + + + align:start position:0% +going to be a little bit before the +solstice how many people think a little + + align:start position:0% +solstice how many people think a little + + + align:start position:0% +solstice how many people think a little +bit after the saled I know people don't + + align:start position:0% +bit after the saled I know people don't + + + align:start position:0% +bit after the saled I know people don't +really know um the uh the the the + + align:start position:0% +really know um the uh the the the + + + align:start position:0% +really know um the uh the the the +reality is that the the earliest sunset + + align:start position:0% +reality is that the the earliest sunset + + + align:start position:0% +reality is that the the earliest sunset +uh would be a little bit before uh the + + align:start position:0% +uh would be a little bit before uh the + + + align:start position:0% +uh would be a little bit before uh the +solstice here and the uh latest Sunrise + + align:start position:0% +solstice here and the uh latest Sunrise + + + align:start position:0% +solstice here and the uh latest Sunrise +would be a little bit after the solstice + + align:start position:0% +would be a little bit after the solstice + + + align:start position:0% +would be a little bit after the solstice +and it flips in summertime it would be + + align:start position:0% +and it flips in summertime it would be + + + align:start position:0% +and it flips in summertime it would be +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +the earliest no the latest Sor the + + align:start position:0% +the earliest no the latest Sor the + + + align:start position:0% +the earliest no the latest Sor the +earliest sunrise and the latest Sunset + + align:start position:0% +earliest sunrise and the latest Sunset + + + align:start position:0% +earliest sunrise and the latest Sunset +yeah before and after the solstice + + align:start position:0% +yeah before and after the solstice + + + align:start position:0% +yeah before and after the solstice +respectively okay and you can kind of + + align:start position:0% +respectively okay and you can kind of + + + align:start position:0% +respectively okay and you can kind of +think about that uh in terms of what is + + align:start position:0% +think about that uh in terms of what is + + + align:start position:0% +think about that uh in terms of what is +the solar + + align:start position:0% +the solar + + + align:start position:0% +the solar +noon um the solar noon is when the uh + + align:start position:0% +noon um the solar noon is when the uh + + + align:start position:0% +noon um the solar noon is when the uh +sun is is directly overhead + + align:start position:0% +sun is is directly overhead + + + align:start position:0% +sun is is directly overhead +relative to our chronological noon which + + align:start position:0% +relative to our chronological noon which + + + align:start position:0% +relative to our chronological noon which +is um I would say less dependent on the + + align:start position:0% +is um I would say less dependent on the + + + align:start position:0% +is um I would say less dependent on the +specific angle of of the uh Earth + + align:start position:0% +specific angle of of the uh Earth + + + align:start position:0% +specific angle of of the uh Earth +relative to the Sun as it moves around + + align:start position:0% +relative to the Sun as it moves around + + + align:start position:0% +relative to the Sun as it moves around +this + + align:start position:0% +this + + + align:start position:0% +this +trajectory let's get more into that in + + align:start position:0% +trajectory let's get more into that in + + + align:start position:0% +trajectory let's get more into that in +recitation I I sense since there wasn't + + align:start position:0% +recitation I I sense since there wasn't + + + align:start position:0% +recitation I I sense since there wasn't +much traction there I don't want to + + align:start position:0% +much traction there I don't want to + + + align:start position:0% +much traction there I don't want to +dwell um + + align:start position:0% +dwell um + + + align:start position:0% +dwell um +okay good good good okay um let's think + + align:start position:0% +okay good good good okay um let's think + + + align:start position:0% +okay good good good okay um let's think +a little bit more in terms of uh in + + align:start position:0% +a little bit more in terms of uh in + + + align:start position:0% +a little bit more in terms of uh in +terms of the uh trajectory of the sun + + align:start position:0% +terms of the uh trajectory of the sun + + + align:start position:0% +terms of the uh trajectory of the sun +later on as we move through the some of + + align:start position:0% +later on as we move through the some of + + + align:start position:0% +later on as we move through the some of +the introductory material I don't want + + align:start position:0% +the introductory material I don't want + + + align:start position:0% +the introductory material I don't want +to uh dwell too much I want to give a + + align:start position:0% +to uh dwell too much I want to give a + + + align:start position:0% +to uh dwell too much I want to give a +little bit of review since I'm sensing + + align:start position:0% +little bit of review since I'm sensing + + + align:start position:0% +little bit of review since I'm sensing +that uh uh not everybody did the + + align:start position:0% +that uh uh not everybody did the + + + align:start position:0% +that uh uh not everybody did the +readings I I expect you to do the + + align:start position:0% +readings I I expect you to do the + + + align:start position:0% +readings I I expect you to do the +readings folks so let's uh let's keep + + align:start position:0% +readings folks so let's uh let's keep + + + align:start position:0% +readings folks so let's uh let's keep +with me here so um a touch of history + + align:start position:0% +with me here so um a touch of history + + + align:start position:0% +with me here so um a touch of history +since that was uh asked for it was + + align:start position:0% +since that was uh asked for it was + + + align:start position:0% +since that was uh asked for it was +requested I decided to uh launch a + + align:start position:0% +requested I decided to uh launch a + + + align:start position:0% +requested I decided to uh launch a +little bit into uh a history of of the + + align:start position:0% +little bit into uh a history of of the + + + align:start position:0% +little bit into uh a history of of the +study of the sun um philosophers going + + align:start position:0% +study of the sun um philosophers going + + + align:start position:0% +study of the sun um philosophers going +back to uh um what I suppose most would + + align:start position:0% +back to uh um what I suppose most would + + + align:start position:0% +back to uh um what I suppose most would +consider early India uh study the sun um + + align:start position:0% +consider early India uh study the sun um + + + align:start position:0% +consider early India uh study the sun um +there were some writings uh of of some + + align:start position:0% +there were some writings uh of of some + + + align:start position:0% +there were some writings uh of of some +of the earlier philosophers that were + + align:start position:0% +of the earlier philosophers that were + + + align:start position:0% +of the earlier philosophers that were +recorded uh some have interpreted these + + align:start position:0% +recorded uh some have interpreted these + + + align:start position:0% +recorded uh some have interpreted these +writings as being indicative of perhaps + + align:start position:0% +writings as being indicative of perhaps + + + align:start position:0% +writings as being indicative of perhaps +heliocentric models these are these are + + align:start position:0% +heliocentric models these are these are + + + align:start position:0% +heliocentric models these are these are +poetry folks it's uh I mean it's it's a + + align:start position:0% +poetry folks it's uh I mean it's it's a + + + align:start position:0% +poetry folks it's uh I mean it's it's a +it's it's it's a very different style of + + align:start position:0% +it's it's it's a very different style of + + + align:start position:0% +it's it's it's a very different style of +communication than what we have today of + + align:start position:0% +communication than what we have today of + + + align:start position:0% +communication than what we have today of +technical writing uh so it's difficult + + align:start position:0% +technical writing uh so it's difficult + + + align:start position:0% +technical writing uh so it's difficult +for us to discern or difficult for me at + + align:start position:0% +for us to discern or difficult for me at + + + align:start position:0% +for us to discern or difficult for me at +least to discern when I read uh the + + align:start position:0% +least to discern when I read uh the + + + align:start position:0% +least to discern when I read uh the +lines verbatim uh if this is really + + align:start position:0% +lines verbatim uh if this is really + + + align:start position:0% +lines verbatim uh if this is really +uh somebody thinking about the hel + + align:start position:0% +uh somebody thinking about the hel + + + align:start position:0% +uh somebody thinking about the hel +Centric model or whether this is um + + align:start position:0% +Centric model or whether this is um + + + align:start position:0% +Centric model or whether this is um +somebody just describing the universe in + + align:start position:0% +somebody just describing the universe in + + + align:start position:0% +somebody just describing the universe in +the best of their abilities um the the + + align:start position:0% +the best of their abilities um the the + + + align:start position:0% +the best of their abilities um the the +the the real I would say the real uh + + align:start position:0% +the the real I would say the real uh + + + align:start position:0% +the the real I would say the real uh +beginnings of heliocentric models um + + align:start position:0% +beginnings of heliocentric models um + + + align:start position:0% +beginnings of heliocentric models um +began in the 3D Century before the + + align:start position:0% +began in the 3D Century before the + + + align:start position:0% +began in the 3D Century before the +Common Era um and the uh the Notions of + + align:start position:0% +Common Era um and the uh the Notions of + + + align:start position:0% +Common Era um and the uh the Notions of +interstellar distances estimated in a + + align:start position:0% +interstellar distances estimated in a + + + align:start position:0% +interstellar distances estimated in a +similar manner to what we just walked + + align:start position:0% +similar manner to what we just walked + + + align:start position:0% +similar manner to what we just walked +through today right estimating the + + align:start position:0% +through today right estimating the + + + align:start position:0% +through today right estimating the +distance between the Earth and the Sun + + align:start position:0% +distance between the Earth and the Sun + + + align:start position:0% +distance between the Earth and the Sun +and then using that as a measure or yard + + align:start position:0% +and then using that as a measure or yard + + + align:start position:0% +and then using that as a measure or yard +stick uh with which to measure the + + align:start position:0% +stick uh with which to measure the + + + align:start position:0% +stick uh with which to measure the +distances to the other planets uh began + + align:start position:0% +distances to the other planets uh began + + + align:start position:0% +distances to the other planets uh began +uh somewhere during that time uh + + align:start position:0% +uh somewhere during that time uh + + + align:start position:0% +uh somewhere during that time uh +likewise these writings of of old um + + align:start position:0% +likewise these writings of of old um + + + align:start position:0% +likewise these writings of of old um +made their way to the Middle East and in + + align:start position:0% +made their way to the Middle East and in + + + align:start position:0% +made their way to the Middle East and in +the 10th and 11th centuries uh of of the + + align:start position:0% +the 10th and 11th centuries uh of of the + + + align:start position:0% +the 10th and 11th centuries uh of of the +Common Era uh the Middle East um the + + align:start position:0% +Common Era uh the Middle East um the + + + align:start position:0% +Common Era uh the Middle East um the +Arab world was really where Science and + + align:start position:0% +Arab world was really where Science and + + + align:start position:0% +Arab world was really where Science and +Technology was at um at in these days + + align:start position:0% +Technology was at um at in these days + + + align:start position:0% +Technology was at um at in these days +the I mean Europe was still largely mild + + align:start position:0% +the I mean Europe was still largely mild + + + align:start position:0% +the I mean Europe was still largely mild +in in um in the Middle Ages starting to + + align:start position:0% +in in um in the Middle Ages starting to + + + align:start position:0% +in in um in the Middle Ages starting to +emerge but in in a few places but uh by + + align:start position:0% +emerge but in in a few places but uh by + + + align:start position:0% +emerge but in in a few places but uh by +and large uh the the carriers of + + align:start position:0% +and large uh the the carriers of + + + align:start position:0% +and large uh the the carriers of +civilization in the western world uh was + + align:start position:0% +civilization in the western world uh was + + + align:start position:0% +civilization in the western world uh was +was were really centered in in some of + + align:start position:0% +was were really centered in in some of + + + align:start position:0% +was were really centered in in some of +the Arab cities in the Middle East and + + align:start position:0% +the Arab cities in the Middle East and + + + align:start position:0% +the Arab cities in the Middle East and +um aluni in particular was uh was very + + align:start position:0% +um aluni in particular was uh was very + + + align:start position:0% +um aluni in particular was uh was very +Avid at at applying um uh methods of + + align:start position:0% +Avid at at applying um uh methods of + + + align:start position:0% +Avid at at applying um uh methods of +astronomical observation in particular + + align:start position:0% +astronomical observation in particular + + + align:start position:0% +astronomical observation in particular +to a travel uh but in the process U + + align:start position:0% +to a travel uh but in the process U + + + align:start position:0% +to a travel uh but in the process U +discovering a thing or two um about uh + + align:start position:0% +discovering a thing or two um about uh + + + align:start position:0% +discovering a thing or two um about uh +about our known universe and of course + + align:start position:0% +about our known universe and of course + + + align:start position:0% +about our known universe and of course +uh finally Johannes Kepler uh in Europe + + align:start position:0% +uh finally Johannes Kepler uh in Europe + + + align:start position:0% +uh finally Johannes Kepler uh in Europe +once it starts to emerge from the Middle + + align:start position:0% +once it starts to emerge from the Middle + + + align:start position:0% +once it starts to emerge from the Middle +Ages uh with really uh you know taking + + align:start position:0% +Ages uh with really uh you know taking + + + align:start position:0% +Ages uh with really uh you know taking +observ from other scientists who very + + align:start position:0% +observ from other scientists who very + + + align:start position:0% +observ from other scientists who very +carefully plotted out the position of + + align:start position:0% +carefully plotted out the position of + + + align:start position:0% +carefully plotted out the position of +the different bodies uh he came up with + + align:start position:0% +the different bodies uh he came up with + + + align:start position:0% +the different bodies uh he came up with +some of the mathematical models that + + align:start position:0% +some of the mathematical models that + + + align:start position:0% +some of the mathematical models that +described uh the uh motion of the + + align:start position:0% +described uh the uh motion of the + + + align:start position:0% +described uh the uh motion of the +planets through the skies and is largely + + align:start position:0% +planets through the skies and is largely + + + align:start position:0% +planets through the skies and is largely +credited with developing a series of + + align:start position:0% +credited with developing a series of + + + align:start position:0% +credited with developing a series of +laws that Define interplanetary + + align:start position:0% +laws that Define interplanetary + + + align:start position:0% +laws that Define interplanetary +motion so um a couple of interesting + + align:start position:0% +motion so um a couple of interesting + + + align:start position:0% +motion so um a couple of interesting +things to note is that International + + align:start position:0% +things to note is that International + + + align:start position:0% +things to note is that International +collaboration was really essential these + + align:start position:0% +collaboration was really essential these + + + align:start position:0% +collaboration was really essential these +ideas didn't develop in isolation they + + align:start position:0% +ideas didn't develop in isolation they + + + align:start position:0% +ideas didn't develop in isolation they +were flowing throughout uh the world + + align:start position:0% +were flowing throughout uh the world + + + align:start position:0% +were flowing throughout uh the world +it's important to know that many of the + + align:start position:0% +it's important to know that many of the + + + align:start position:0% +it's important to know that many of the +scientists were well traveled polyglots + + align:start position:0% +scientists were well traveled polyglots + + + align:start position:0% +scientists were well traveled polyglots +meaning they spoke different languages + + align:start position:0% +meaning they spoke different languages + + + align:start position:0% +meaning they spoke different languages +and that's how they were able to + + align:start position:0% +and that's how they were able to + + + align:start position:0% +and that's how they were able to +interpret the texts and readings of + + align:start position:0% +interpret the texts and readings of + + + align:start position:0% +interpret the texts and readings of +other of other people and it's also to + + align:start position:0% +other of other people and it's also to + + + align:start position:0% +other of other people and it's also to +note that parallel astronomical + + align:start position:0% +note that parallel astronomical + + + align:start position:0% +note that parallel astronomical +developments were happening in in other + + align:start position:0% +developments were happening in in other + + + align:start position:0% +developments were happening in in other +regions of the world uh the Far East + + align:start position:0% +regions of the world uh the Far East + + + align:start position:0% +regions of the world uh the Far East +meso America and so forth right and so + + align:start position:0% +meso America and so forth right and so + + + align:start position:0% +meso America and so forth right and so +uh obviously there there may have been + + align:start position:0% +uh obviously there there may have been + + + align:start position:0% +uh obviously there there may have been +some uh communication I would say rather + + align:start position:0% +some uh communication I would say rather + + + align:start position:0% +some uh communication I would say rather +uh sparse between um especially with the + + align:start position:0% +uh sparse between um especially with the + + + align:start position:0% +uh sparse between um especially with the +Far East but you know there there was a + + align:start position:0% +Far East but you know there there was a + + + align:start position:0% +Far East but you know there there was a +fair amount of communication between um + + align:start position:0% +fair amount of communication between um + + + align:start position:0% +fair amount of communication between um +between these regions here and you can + + align:start position:0% +between these regions here and you can + + + align:start position:0% +between these regions here and you can +imagine writings or ideas traveling from + + align:start position:0% +imagine writings or ideas traveling from + + + align:start position:0% +imagine writings or ideas traveling from +Word of Mouth uh along uh trade routes + + align:start position:0% +Word of Mouth uh along uh trade routes + + + align:start position:0% +Word of Mouth uh along uh trade routes +so there was uh was some communication + + align:start position:0% +so there was uh was some communication + + + align:start position:0% +so there was uh was some communication +so back to our learning objectives today + + align:start position:0% +so back to our learning objectives today + + + align:start position:0% +so back to our learning objectives today +we're about to quantify the available + + align:start position:0% +we're about to quantify the available + + + align:start position:0% +we're about to quantify the available +solar resource relative to human + + align:start position:0% +solar resource relative to human + + + align:start position:0% +solar resource relative to human +energies and other fuel sources so let's + + align:start position:0% +energies and other fuel sources so let's + + + align:start position:0% +energies and other fuel sources so let's +do that we'll jump right into one of the + + align:start position:0% +do that we'll jump right into one of the + + + align:start position:0% +do that we'll jump right into one of the +slides that I showed you last time uh + + align:start position:0% +slides that I showed you last time uh + + + align:start position:0% +slides that I showed you last time uh +this is in terms of terawatts a + + align:start position:0% +this is in terms of terawatts a + + + align:start position:0% +this is in terms of terawatts a +terawatts is a unit of power um very big + + align:start position:0% +terawatts is a unit of power um very big + + + align:start position:0% +terawatts is a unit of power um very big +one Tera is 10 to the 12 um and you can + + align:start position:0% +one Tera is 10 to the 12 um and you can + + + align:start position:0% +one Tera is 10 to the 12 um and you can +see here the resource of the sun + + align:start position:0% +see here the resource of the sun + + + align:start position:0% +see here the resource of the sun +relative to the wind energy resource + + align:start position:0% +relative to the wind energy resource + + + align:start position:0% +relative to the wind energy resource +space relative to human energy needs if + + align:start position:0% +space relative to human energy needs if + + + align:start position:0% +space relative to human energy needs if +we just consider the resource falling on + + align:start position:0% +we just consider the resource falling on + + + align:start position:0% +we just consider the resource falling on +the Earth's surface as opposed to that + + align:start position:0% +the Earth's surface as opposed to that + + + align:start position:0% +the Earth's surface as opposed to that +falling in the outer atmosphere um + + align:start position:0% +falling in the outer atmosphere um + + + align:start position:0% +falling in the outer atmosphere um +there's a little bit of a discount but + + align:start position:0% +there's a little bit of a discount but + + + align:start position:0% +there's a little bit of a discount but +we're still uh very large compared to + + align:start position:0% +we're still uh very large compared to + + + align:start position:0% +we're still uh very large compared to +human energy use and if we redefine our + + align:start position:0% +human energy use and if we redefine our + + + align:start position:0% +human energy use and if we redefine our +units from terawatts into hc's which are + + align:start position:0% +units from terawatts into hc's which are + + + align:start position:0% +units from terawatts into hc's which are +uh human energy consumptions defined in + + align:start position:0% +uh human energy consumptions defined in + + + align:start position:0% +uh human energy consumptions defined in +say 2050 uh where one HC is the uh + + align:start position:0% +say 2050 uh where one HC is the uh + + + align:start position:0% +say 2050 uh where one HC is the uh +average let's say um energy burn rate uh + + align:start position:0% +average let's say um energy burn rate uh + + + align:start position:0% +average let's say um energy burn rate uh +of the uh of of 2050 you can see here + + align:start position:0% +of the uh of of 2050 you can see here + + + align:start position:0% +of the uh of of 2050 you can see here +that these numbers are a few orders of + + align:start position:0% +that these numbers are a few orders of + + + align:start position:0% +that these numbers are a few orders of +magnitude larger than what our human + + align:start position:0% +magnitude larger than what our human + + + align:start position:0% +magnitude larger than what our human +energy needs are so if you were able to + + align:start position:0% +energy needs are so if you were able to + + + align:start position:0% +energy needs are so if you were able to +capture only 1% of all of the solar uh + + align:start position:0% +capture only 1% of all of the solar uh + + + align:start position:0% +capture only 1% of all of the solar uh +resource falling on the Earth's crust uh + + align:start position:0% +resource falling on the Earth's crust uh + + + align:start position:0% +resource falling on the Earth's crust uh +we would be uh actually in pretty good + + align:start position:0% +we would be uh actually in pretty good + + + align:start position:0% +we would be uh actually in pretty good +shape and 1% of the total uh land area + + align:start position:0% +shape and 1% of the total uh land area + + + align:start position:0% +shape and 1% of the total uh land area +on the earth crust I believe somewhere + + align:start position:0% +on the earth crust I believe somewhere + + + align:start position:0% +on the earth crust I believe somewhere +between 1 and 2% of the United States is + + align:start position:0% +between 1 and 2% of the United States is + + + align:start position:0% +between 1 and 2% of the United States is +covered in Asphalt right now for roads + + align:start position:0% +covered in Asphalt right now for roads + + + align:start position:0% +covered in Asphalt right now for roads +so uh this could be on houses on + + align:start position:0% +so uh this could be on houses on + + + align:start position:0% +so uh this could be on houses on +rooftops and buildings and so forth we + + align:start position:0% +rooftops and buildings and so forth we + + + align:start position:0% +rooftops and buildings and so forth we +wouldn't necessarily have to exclusively + + align:start position:0% +wouldn't necessarily have to exclusively + + + align:start position:0% +wouldn't necessarily have to exclusively +uh repave uh virgin Farmland with uh + + align:start position:0% +uh repave uh virgin Farmland with uh + + + align:start position:0% +uh repave uh virgin Farmland with uh +with uh solar panels so going back to + + align:start position:0% +with uh solar panels so going back to + + + align:start position:0% +with uh solar panels so going back to +quantifying the solar power we have our + + align:start position:0% +quantifying the solar power we have our + + + align:start position:0% +quantifying the solar power we have our +sun uh we're going to start by + + align:start position:0% +sun uh we're going to start by + + + align:start position:0% +sun uh we're going to start by +quantifying the solar resource by + + align:start position:0% +quantifying the solar resource by + + + align:start position:0% +quantifying the solar resource by +assuming that the sun is a black body + + align:start position:0% +assuming that the sun is a black body + + + align:start position:0% +assuming that the sun is a black body +the same way that um hot objects emit + + align:start position:0% +the same way that um hot objects emit + + + align:start position:0% +the same way that um hot objects emit +light say for example when you turn up + + align:start position:0% +light say for example when you turn up + + + align:start position:0% +light say for example when you turn up +your stove and you have a very uh Warm + + align:start position:0% +your stove and you have a very uh Warm + + + align:start position:0% +your stove and you have a very uh Warm +Glow uh coming out of it um the sun is + + align:start position:0% +Glow uh coming out of it um the sun is + + + align:start position:0% +Glow uh coming out of it um the sun is +as well a hot body uh a black body sorry + + align:start position:0% +as well a hot body uh a black body sorry + + + align:start position:0% +as well a hot body uh a black body sorry +very hot as well somewhere around 6,000 + + align:start position:0% +very hot as well somewhere around 6,000 + + + align:start position:0% +very hot as well somewhere around 6,000 +Kelvin and the total radiated power is + + align:start position:0% +Kelvin and the total radiated power is + + + align:start position:0% +Kelvin and the total radiated power is +given by stepan boltzman's law here uh + + align:start position:0% +given by stepan boltzman's law here uh + + + align:start position:0% +given by stepan boltzman's law here uh +in the following way where we have + + align:start position:0% +in the following way where we have + + + align:start position:0% +in the following way where we have +temperature to the fourth um and the + + align:start position:0% +temperature to the fourth um and the + + + align:start position:0% +temperature to the fourth um and the +temperature is somewhere around 6,000 + + align:start position:0% +temperature is somewhere around 6,000 + + + align:start position:0% +temperature is somewhere around 6,000 +Kelvin and so we have this power being + + align:start position:0% +Kelvin and so we have this power being + + + align:start position:0% +Kelvin and so we have this power being +radiated out at the surface of the Sun + + align:start position:0% +radiated out at the surface of the Sun + + + align:start position:0% +radiated out at the surface of the Sun +and then as it travels outward um it it + + align:start position:0% +and then as it travels outward um it it + + + align:start position:0% +and then as it travels outward um it it +becomes you could say diluted in effect + + align:start position:0% +becomes you could say diluted in effect + + + align:start position:0% +becomes you could say diluted in effect +because the the total surface area of + + align:start position:0% +because the the total surface area of + + + align:start position:0% +because the the total surface area of +that sphere is increasing obviously as R + + align:start position:0% +that sphere is increasing obviously as R + + + align:start position:0% +that sphere is increasing obviously as R +squar and so by the time that that Light + + align:start position:0% +squar and so by the time that that Light + + + align:start position:0% +squar and so by the time that that Light +reaches the Earth it's only a very small + + align:start position:0% +reaches the Earth it's only a very small + + + align:start position:0% +reaches the Earth it's only a very small +cross-section or very small solid angle + + align:start position:0% +cross-section or very small solid angle + + + align:start position:0% +cross-section or very small solid angle +to be more precise of the of the sun's + + align:start position:0% +to be more precise of the of the sun's + + + align:start position:0% +to be more precise of the of the sun's +surface that is radiating directly at + + align:start position:0% +surface that is radiating directly at + + + align:start position:0% +surface that is radiating directly at +the Earth right here because uh this in + + align:start position:0% +the Earth right here because uh this in + + + align:start position:0% +the Earth right here because uh this in +the absence of scattering centers in the + + align:start position:0% +the absence of scattering centers in the + + + align:start position:0% +the absence of scattering centers in the +universe that might reflect or bounce + + align:start position:0% +universe that might reflect or bounce + + + align:start position:0% +universe that might reflect or bounce +the light back toward the Earth and you + + align:start position:0% +the light back toward the Earth and you + + + align:start position:0% +the light back toward the Earth and you +can calculate the total power incident + + align:start position:0% +can calculate the total power incident + + + align:start position:0% +can calculate the total power incident +on the Earth by that simple formula + + align:start position:0% +on the Earth by that simple formula + + + align:start position:0% +on the Earth by that simple formula +right there what is the radius of the + + align:start position:0% +right there what is the radius of the + + + align:start position:0% +right there what is the radius of the +Earth again one of these simple numbers + + align:start position:0% +Earth again one of these simple numbers + + + align:start position:0% +Earth again one of these simple numbers +you should kind of have in your head + + align:start position:0% +you should kind of have in your head + + + align:start position:0% +you should kind of have in your head +6370 km somewhere in that order right + + align:start position:0% +6370 km somewhere in that order right + + + align:start position:0% +6370 km somewhere in that order right +and so you can begin estim + + align:start position:0% +and so you can begin estim + + + align:start position:0% +and so you can begin estim +uh here the the total power on the order + + align:start position:0% +uh here the the total power on the order + + + align:start position:0% +uh here the the total power on the order +order of magnitude it's it's going to be + + align:start position:0% +order of magnitude it's it's going to be + + + align:start position:0% +order of magnitude it's it's going to be +tiny compared to the total power that + + align:start position:0% +tiny compared to the total power that + + + align:start position:0% +tiny compared to the total power that +the sun is radiating thankfully or else + + align:start position:0% +the sun is radiating thankfully or else + + + align:start position:0% +the sun is radiating thankfully or else +we'd be pretty hot right now so um the + + align:start position:0% +we'd be pretty hot right now so um the + + + align:start position:0% +we'd be pretty hot right now so um the +average uh Power coming from the Sun on + + align:start position:0% +average uh Power coming from the Sun on + + + align:start position:0% +average uh Power coming from the Sun on +the surface of the outer atmosphere is + + align:start position:0% +the surface of the outer atmosphere is + + + align:start position:0% +the surface of the outer atmosphere is +around 1366 watts per square meter who's + + align:start position:0% +around 1366 watts per square meter who's + + + align:start position:0% +around 1366 watts per square meter who's +heard of 1366 before yeah you've heard + + align:start position:0% +heard of 1366 before yeah you've heard + + + align:start position:0% +heard of 1366 before yeah you've heard +about it all right you know where the + + align:start position:0% +about it all right you know where the + + + align:start position:0% +about it all right you know where the +number comes from now all right it's + + align:start position:0% +number comes from now all right it's + + + align:start position:0% +number comes from now all right it's +pretty pretty wonky um 1366 is a startup + + align:start position:0% +pretty pretty wonky um 1366 is a startup + + + align:start position:0% +pretty pretty wonky um 1366 is a startup +company spin-off of MIT focused on solar + + align:start position:0% +company spin-off of MIT focused on solar + + + align:start position:0% +company spin-off of MIT focused on solar +energy um okay and so that's at the + + align:start position:0% +energy um okay and so that's at the + + + align:start position:0% +energy um okay and so that's at the +Equinox which we just learned is + + align:start position:0% +Equinox which we just learned is + + + align:start position:0% +Equinox which we just learned is +occurring somewhere around March 21st um + + align:start position:0% +occurring somewhere around March 21st um + + + align:start position:0% +occurring somewhere around March 21st um +September 21st coming up soon + + align:start position:0% +September 21st coming up soon + + + align:start position:0% +September 21st coming up soon +celebration um the ratio of the of the + + align:start position:0% +celebration um the ratio of the of the + + + align:start position:0% +celebration um the ratio of the of the +surface areas of the Spheres is really + + align:start position:0% +surface areas of the Spheres is really + + + align:start position:0% +surface areas of the Spheres is really +something to keep in mind right there + + align:start position:0% +something to keep in mind right there + + + align:start position:0% +something to keep in mind right there +okay so we've Quantified the available + + align:start position:0% +okay so we've Quantified the available + + + align:start position:0% +okay so we've Quantified the available +resource relative to human energy needs + + align:start position:0% +resource relative to human energy needs + + + align:start position:0% +resource relative to human energy needs +now um we have to come up with some + + align:start position:0% +now um we have to come up with some + + + align:start position:0% +now um we have to come up with some +language that we use to describe the + + align:start position:0% +language that we use to describe the + + + align:start position:0% +language that we use to describe the +sunlight movement moving through the + + align:start position:0% +sunlight movement moving through the + + + align:start position:0% +sunlight movement moving through the +atmosphere of the earth and reaching the + + align:start position:0% +atmosphere of the earth and reaching the + + + align:start position:0% +atmosphere of the earth and reaching the +surface of the Earth right so we're + + align:start position:0% +surface of the Earth right so we're + + + align:start position:0% +surface of the Earth right so we're +going to use What's called the air mass + + align:start position:0% +going to use What's called the air mass + + + align:start position:0% +going to use What's called the air mass +convention or am convention am stands + + align:start position:0% +convention or am convention am stands + + + align:start position:0% +convention or am convention am stands +for air mass um even without knowing + + align:start position:0% +for air mass um even without knowing + + + align:start position:0% +for air mass um even without knowing +much about how the light is absorbed or + + align:start position:0% +much about how the light is absorbed or + + + align:start position:0% +much about how the light is absorbed or +how to quantify it mathematically we can + + align:start position:0% +how to quantify it mathematically we can + + + align:start position:0% +how to quantify it mathematically we can +assume that as uh our atmosphere + + align:start position:0% +assume that as uh our atmosphere + + + align:start position:0% +assume that as uh our atmosphere +contains molecules it contains + + align:start position:0% +contains molecules it contains + + + align:start position:0% +contains molecules it contains +particulate matter and that's going to + + align:start position:0% +particulate matter and that's going to + + + align:start position:0% +particulate matter and that's going to +interact with the light in some way it's + + align:start position:0% +interact with the light in some way it's + + + align:start position:0% +interact with the light in some way it's +probably going to either absorb or + + align:start position:0% +probably going to either absorb or + + + align:start position:0% +probably going to either absorb or +scatter it and so as the light passes + + align:start position:0% +scatter it and so as the light passes + + + align:start position:0% +scatter it and so as the light passes +through our atmosphere there's going to + + align:start position:0% +through our atmosphere there's going to + + + align:start position:0% +through our atmosphere there's going to +be some absorption and the greater the + + align:start position:0% +be some absorption and the greater the + + + align:start position:0% +be some absorption and the greater the +distance the greater the optic path + + align:start position:0% +distance the greater the optic path + + + align:start position:0% +distance the greater the optic path +length through the atmosphere the more + + align:start position:0% +length through the atmosphere the more + + + align:start position:0% +length through the atmosphere the more +absorption and more scattering there + + align:start position:0% +absorption and more scattering there + + + align:start position:0% +absorption and more scattering there +will be and so we use air mass or am + + align:start position:0% +will be and so we use air mass or am + + + align:start position:0% +will be and so we use air mass or am +convention to define the path length of + + align:start position:0% +convention to define the path length of + + + align:start position:0% +convention to define the path length of +the path distance through the atmosphere + + align:start position:0% +the path distance through the atmosphere + + + align:start position:0% +the path distance through the atmosphere +am0 would mean the outer atmosphere am1 + + align:start position:0% +am0 would mean the outer atmosphere am1 + + + align:start position:0% +am0 would mean the outer atmosphere am1 +would be essentially just going straight + + align:start position:0% +would be essentially just going straight + + + align:start position:0% +would be essentially just going straight +through uh normal incidence so that the + + align:start position:0% +through uh normal incidence so that the + + + align:start position:0% +through uh normal incidence so that the +direction of the of the the trajectory + + align:start position:0% +direction of the of the the trajectory + + + align:start position:0% +direction of the of the the trajectory +of the light is parallel to the surface + + align:start position:0% +of the light is parallel to the surface + + + align:start position:0% +of the light is parallel to the surface +normal of the Earth at that location and + + align:start position:0% +normal of the Earth at that location and + + + align:start position:0% +normal of the Earth at that location and +then air mass 1.5 and so forth is as we + + align:start position:0% +then air mass 1.5 and so forth is as we + + + align:start position:0% +then air mass 1.5 and so forth is as we +increase the angle of the entry of light + + align:start position:0% +increase the angle of the entry of light + + + align:start position:0% +increase the angle of the entry of light +relative to the surface normal so in + + align:start position:0% +relative to the surface normal so in + + + align:start position:0% +relative to the surface normal so in +other words as we go further from the + + align:start position:0% +other words as we go further from the + + + align:start position:0% +other words as we go further from the +equator to Northern latitudes that air + + align:start position:0% +equator to Northern latitudes that air + + + align:start position:0% +equator to Northern latitudes that air +mass number is going to go up up up okay + + align:start position:0% +mass number is going to go up up up okay + + + align:start position:0% +mass number is going to go up up up okay +we'll explain it with a few graphs and + + align:start position:0% +we'll explain it with a few graphs and + + + align:start position:0% +we'll explain it with a few graphs and +figures and a few slides so we have our + + align:start position:0% +figures and a few slides so we have our + + + align:start position:0% +figures and a few slides so we have our +atmospheric absorption um when you just + + align:start position:0% +atmospheric absorption um when you just + + + align:start position:0% +atmospheric absorption um when you just +glance at the Earth from these beautiful + + align:start position:0% +glance at the Earth from these beautiful + + + align:start position:0% +glance at the Earth from these beautiful +uh pictures taken from outer space we + + align:start position:0% +uh pictures taken from outer space we + + + align:start position:0% +uh pictures taken from outer space we +can see very obviously the clouds + + align:start position:0% +can see very obviously the clouds + + + align:start position:0% +can see very obviously the clouds +present and more importantly if we were + + align:start position:0% +present and more importantly if we were + + + align:start position:0% +present and more importantly if we were +to zoom in on one of these regions right + + align:start position:0% +to zoom in on one of these regions right + + + align:start position:0% +to zoom in on one of these regions right +here we would see uh the um we would see + + align:start position:0% +here we would see uh the um we would see + + + align:start position:0% +here we would see uh the um we would see +this this uh bluish Hue coming from uh + + align:start position:0% +this this uh bluish Hue coming from uh + + + align:start position:0% +this this uh bluish Hue coming from uh +our atmosphere which is scattering + + align:start position:0% +our atmosphere which is scattering + + + align:start position:0% +our atmosphere which is scattering +preferentially the shorter wavelengths + + align:start position:0% +preferentially the shorter wavelengths + + + align:start position:0% +preferentially the shorter wavelengths +of light and um more importantly this + + align:start position:0% +of light and um more importantly this + + + align:start position:0% +of light and um more importantly this +radius right here is somewhere in the + + align:start position:0% +radius right here is somewhere in the + + + align:start position:0% +radius right here is somewhere in the +order of 6,370 kilom and this thin + + align:start position:0% +order of 6,370 kilom and this thin + + + align:start position:0% +order of 6,370 kilom and this thin +atmospheric shell is in the order of + + align:start position:0% +atmospheric shell is in the order of + + + align:start position:0% +atmospheric shell is in the order of +30 right so um that's why you don't + + align:start position:0% +30 right so um that's why you don't + + + align:start position:0% +30 right so um that's why you don't +really see too much of a of a ring + + align:start position:0% +really see too much of a of a ring + + + align:start position:0% +really see too much of a of a ring +around the planet from this distance so + + align:start position:0% +around the planet from this distance so + + + align:start position:0% +around the planet from this distance so +atmospheric effects let's try to bend + + align:start position:0% +atmospheric effects let's try to bend + + + align:start position:0% +atmospheric effects let's try to bend +them into discret buckets this is a + + align:start position:0% +them into discret buckets this is a + + + align:start position:0% +them into discret buckets this is a +simplification but it helps us gain a + + align:start position:0% +simplification but it helps us gain a + + + align:start position:0% +simplification but it helps us gain a +foothold in understanding and then from + + align:start position:0% +foothold in understanding and then from + + + align:start position:0% +foothold in understanding and then from +there we can uh make our understanding a + + align:start position:0% +there we can uh make our understanding a + + + align:start position:0% +there we can uh make our understanding a +bit more complex so we have incoming + + align:start position:0% +bit more complex so we have incoming + + + align:start position:0% +bit more complex so we have incoming +solar radiation coming from here we have + + align:start position:0% +solar radiation coming from here we have + + + align:start position:0% +solar radiation coming from here we have +a number now that's 342 watts per square + + align:start position:0% +a number now that's 342 watts per square + + + align:start position:0% +a number now that's 342 watts per square +meter why is that number so much lower + + align:start position:0% +meter why is that number so much lower + + + align:start position:0% +meter why is that number so much lower +than the + + align:start position:0% +than the + + + align:start position:0% +than the +1366 that we were just talking + + align:start position:0% + + + + align:start position:0% + +about yeah so this is meant to be uh an + + align:start position:0% +about yeah so this is meant to be uh an + + + align:start position:0% +about yeah so this is meant to be uh an +average uh over the entire day at one + + align:start position:0% +average uh over the entire day at one + + + align:start position:0% +average uh over the entire day at one +fixed point along the ground right so as + + align:start position:0% +fixed point along the ground right so as + + + align:start position:0% +fixed point along the ground right so as +we're rotating around we have at least + + align:start position:0% +we're rotating around we have at least + + + align:start position:0% +we're rotating around we have at least +half of the day normally when we don't + + align:start position:0% +half of the day normally when we don't + + + align:start position:0% +half of the day normally when we don't +have sunlight and then there's um I + + align:start position:0% +have sunlight and then there's um I + + + align:start position:0% +have sunlight and then there's um I +would say the the cosine Theta angle is + + align:start position:0% +would say the the cosine Theta angle is + + + align:start position:0% +would say the the cosine Theta angle is +not one at all times it's uh very rarely + + align:start position:0% +not one at all times it's uh very rarely + + + align:start position:0% +not one at all times it's uh very rarely +one and so this is a a bit of a + + align:start position:0% +one and so this is a a bit of a + + + align:start position:0% +one and so this is a a bit of a +discounted incoming solar radiation + + align:start position:0% +discounted incoming solar radiation + + + align:start position:0% +discounted incoming solar radiation +essentially a Time average solar + + align:start position:0% +essentially a Time average solar + + + align:start position:0% +essentially a Time average solar +radiation for a given patch of the + + align:start position:0% +radiation for a given patch of the + + + align:start position:0% +radiation for a given patch of the +planet over a typical day and so we have + + align:start position:0% +planet over a typical day and so we have + + + align:start position:0% +planet over a typical day and so we have +a variety of of processes here we have + + align:start position:0% +a variety of of processes here we have + + + align:start position:0% +a variety of of processes here we have +reflection off of clouds that's pretty + + align:start position:0% +reflection off of clouds that's pretty + + + align:start position:0% +reflection off of clouds that's pretty +clear to to see from here looks nice and + + align:start position:0% +clear to to see from here looks nice and + + + align:start position:0% +clear to to see from here looks nice and +white um we have some absorbed by the + + align:start position:0% +white um we have some absorbed by the + + + align:start position:0% +white um we have some absorbed by the +atmosphere uh typically in in rotational + + align:start position:0% +atmosphere uh typically in in rotational + + + align:start position:0% +atmosphere uh typically in in rotational +vibrational modes of of molecules uh up + + align:start position:0% +vibrational modes of of molecules uh up + + + align:start position:0% +vibrational modes of of molecules uh up +in the outer atmosphere uh sometimes by + + align:start position:0% +in the outer atmosphere uh sometimes by + + + align:start position:0% +in the outer atmosphere uh sometimes by +particulate matter as well um and then + + align:start position:0% +particulate matter as well um and then + + + align:start position:0% +particulate matter as well um and then +we have uh the amount that is absorbed + + align:start position:0% +we have uh the amount that is absorbed + + + align:start position:0% +we have uh the amount that is absorbed +here by the surface of course reflected + + align:start position:0% +here by the surface of course reflected + + + align:start position:0% +here by the surface of course reflected +as well and so the the amount that's + + align:start position:0% +as well and so the the amount that's + + + align:start position:0% +as well and so the the amount that's +incident on the surface or coming down + + align:start position:0% +incident on the surface or coming down + + + align:start position:0% +incident on the surface or coming down +to us is what we can actually use to + + align:start position:0% +to us is what we can actually use to + + + align:start position:0% +to us is what we can actually use to +make solar energy and this is an average + + align:start position:0% +make solar energy and this is an average + + + align:start position:0% +make solar energy and this is an average +right because sometimes the cloud cover + + align:start position:0% +right because sometimes the cloud cover + + + align:start position:0% +right because sometimes the cloud cover +is a lot greater uh and for that + + align:start position:0% +is a lot greater uh and for that + + + align:start position:0% +is a lot greater uh and for that +particular day uh we will have a lot + + align:start position:0% +particular day uh we will have a lot + + + align:start position:0% +particular day uh we will have a lot +less resource striking the ground at + + align:start position:0% +less resource striking the ground at + + + align:start position:0% +less resource striking the ground at +that given time this over here this is + + align:start position:0% +that given time this over here this is + + + align:start position:0% +that given time this over here this is +all mostly infrared right where this is + + align:start position:0% +all mostly infrared right where this is + + + align:start position:0% +all mostly infrared right where this is +visible coming in once the light gets + + align:start position:0% +visible coming in once the light gets + + + align:start position:0% +visible coming in once the light gets +absorbed and then gets reemitted uh get + + align:start position:0% +absorbed and then gets reemitted uh get + + + align:start position:0% +absorbed and then gets reemitted uh get +usually gets reemitted in longer + + align:start position:0% +usually gets reemitted in longer + + + align:start position:0% +usually gets reemitted in longer +wavelength uh light or the infrared + + align:start position:0% +wavelength uh light or the infrared + + + align:start position:0% +wavelength uh light or the infrared +light and this is the stuff that gets uh + + align:start position:0% +light and this is the stuff that gets uh + + + align:start position:0% +light and this is the stuff that gets uh +blocked by or absorbed by greenhouse + + align:start position:0% +blocked by or absorbed by greenhouse + + + align:start position:0% +blocked by or absorbed by greenhouse +gases and then reemitted equ angularly + + align:start position:0% +gases and then reemitted equ angularly + + + align:start position:0% +gases and then reemitted equ angularly +and some of it makes its way back to the + + align:start position:0% +and some of it makes its way back to the + + + align:start position:0% +and some of it makes its way back to the +Earth right okay so air mass let's + + align:start position:0% +Earth right okay so air mass let's + + + align:start position:0% +Earth right okay so air mass let's +define that uh so that we have a common + + align:start position:0% +define that uh so that we have a common + + + align:start position:0% +define that uh so that we have a common +language that we can use to describe the + + align:start position:0% +language that we can use to describe the + + + align:start position:0% +language that we can use to describe the +solar resource from place to place so + + align:start position:0% +solar resource from place to place so + + + align:start position:0% +solar resource from place to place so +again this is the sun this is the + + align:start position:0% +again this is the sun this is the + + + align:start position:0% +again this is the sun this is the +surface right here and let's imagine + + align:start position:0% +surface right here and let's imagine + + + align:start position:0% +surface right here and let's imagine +that the angle between the incident + + align:start position:0% +that the angle between the incident + + + align:start position:0% +that the angle between the incident +sunlight and the surface normal is zero + + align:start position:0% +sunlight and the surface normal is zero + + + align:start position:0% +sunlight and the surface normal is zero +such that the cosine Theta term is one + + align:start position:0% +such that the cosine Theta term is one + + + align:start position:0% +such that the cosine Theta term is one +air mass here at this point at this + + align:start position:0% +air mass here at this point at this + + + align:start position:0% +air mass here at this point at this +point on the surface of the Earth is + + align:start position:0% +point on the surface of the Earth is + + + align:start position:0% +point on the surface of the Earth is +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +am1 so we call air mass one if the Sun + + align:start position:0% +am1 so we call air mass one if the Sun + + + align:start position:0% +am1 so we call air mass one if the Sun +is literally directly overhead + + align:start position:0% +is literally directly overhead + + + align:start position:0% +is literally directly overhead +what did we learn about the declination + + align:start position:0% +what did we learn about the declination + + + align:start position:0% +what did we learn about the declination +angle of the earth it's about 23 and5 + + align:start position:0% +angle of the earth it's about 23 and5 + + + align:start position:0% +angle of the earth it's about 23 and5 +degrees right how far North are we what + + align:start position:0% +degrees right how far North are we what + + + align:start position:0% +degrees right how far North are we what +is our what is our latitude here in + + align:start position:0% +is our what is our latitude here in + + + align:start position:0% +is our what is our latitude here in +Boston 41 42 is right so let's for + + align:start position:0% +Boston 41 42 is right so let's for + + + align:start position:0% +Boston 41 42 is right so let's for +Simplicity + + align:start position:0% +Simplicity + + + align:start position:0% +Simplicity +say + + align:start position:0% +say + + + align:start position:0% +say +that here in + + align:start position:0% +that here in + + + align:start position:0% +that here in +Boston our + + align:start position:0% + + + + align:start position:0% + +latitude of Bost and Logan airport is + + align:start position:0% +latitude of Bost and Logan airport is + + + align:start position:0% +latitude of Bost and Logan airport is +approximately 41 Dees North + + align:start position:0% +approximately 41 Dees North + + + align:start position:0% +approximately 41 Dees North +and let's say that the + + align:start position:0% + + + + align:start position:0% + +declination of our + + align:start position:0% +declination of our + + + align:start position:0% +declination of our +planet is approximately 23 and + + align:start position:0% +planet is approximately 23 and + + + align:start position:0% +planet is approximately 23 and +12° right so what would be the angle of + + align:start position:0% +12° right so what would be the angle of + + + align:start position:0% +12° right so what would be the angle of +the Sun in the sky if you were to lie on + + align:start position:0% +the Sun in the sky if you were to lie on + + + align:start position:0% +the Sun in the sky if you were to lie on +your back in the middle of the summer + + align:start position:0% +your back in the middle of the summer + + + align:start position:0% +your back in the middle of the summer +solstice and the middle of the winter + + align:start position:0% +solstice and the middle of the winter + + + align:start position:0% +solstice and the middle of the winter +solstice and you're lying straight on + + align:start position:0% +solstice and you're lying straight on + + + align:start position:0% +solstice and you're lying straight on +your back looking up at solar noon what + + align:start position:0% +your back looking up at solar noon what + + + align:start position:0% +your back looking up at solar noon what +would the angle of the Sun in the sky be + + align:start position:0% +would the angle of the Sun in the sky be + + + align:start position:0% +would the angle of the Sun in the sky be +relative to the surface normal how far + + align:start position:0% +relative to the surface normal how far + + + align:start position:0% +relative to the surface normal how far +south would the sun be imagine that this + + align:start position:0% +south would the sun be imagine that this + + + align:start position:0% +south would the sun be imagine that this +is 0° and that's 90 right so relative to + + align:start position:0% +is 0° and that's 90 right so relative to + + + align:start position:0% +is 0° and that's 90 right so relative to +this angle right here where would the + + align:start position:0% +this angle right here where would the + + + align:start position:0% +this angle right here where would the +sun be in the sky why don't you turn to + + align:start position:0% +sun be in the sky why don't you turn to + + + align:start position:0% +sun be in the sky why don't you turn to +your neighbor right now and + + align:start position:0% +your neighbor right now and + + + align:start position:0% +your neighbor right now and +discuss on the summer solstice the + + align:start position:0% +discuss on the summer solstice the + + + align:start position:0% +discuss on the summer solstice the +winter + + align:start position:0% +winter + + + align:start position:0% +winter +solstice come up with us some set of + + align:start position:0% +solstice come up with us some set of + + + align:start position:0% +solstice come up with us some set of +angles there + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +all right folks what do we come up with + + align:start position:0% +all right folks what do we come up with + + + align:start position:0% +all right folks what do we come up with +for the this is our little human being u + + align:start position:0% +for the this is our little human being u + + + align:start position:0% +for the this is our little human being u +in Boston this is south and that's North + + align:start position:0% +in Boston this is south and that's North + + + align:start position:0% +in Boston this is south and that's North +and we're at the solar noon in the + + align:start position:0% +and we're at the solar noon in the + + + align:start position:0% +and we're at the solar noon in the +winter solstice and the summer solstice + + align:start position:0% +winter solstice and the summer solstice + + + align:start position:0% +winter solstice and the summer solstice +so here's here's you this is directly + + align:start position:0% +so here's here's you this is directly + + + align:start position:0% +so here's here's you this is directly +above so let's say if you're lying on + + align:start position:0% +above so let's say if you're lying on + + + align:start position:0% +above so let's say if you're lying on +your back and looking straight up that's + + align:start position:0% +your back and looking straight up that's + + + align:start position:0% +your back and looking straight up that's +the surface normal of the Earth in the + + align:start position:0% +the surface normal of the Earth in the + + + align:start position:0% +the surface normal of the Earth in the +summer at solar noon the sun would be at + + align:start position:0% +summer at solar noon the sun would be at + + + align:start position:0% +summer at solar noon the sun would be at +what angle relative to the surface + + align:start position:0% +what angle relative to the surface + + + align:start position:0% +what angle relative to the surface +normal of the + + align:start position:0% +normal of the + + + align:start position:0% +normal of the +earth 17 and2 somewhere around there and + + align:start position:0% +earth 17 and2 somewhere around there and + + + align:start position:0% +earth 17 and2 somewhere around there and +how did you get that + + align:start position:0% +how did you get that + + + align:start position:0% +how did you get that +number subtract those two right so you + + align:start position:0% +number subtract those two right so you + + + align:start position:0% +number subtract those two right so you +get 41 minus 232 you're somewhere around + + align:start position:0% +get 41 minus 232 you're somewhere around + + + align:start position:0% +get 41 minus 232 you're somewhere around +17 18 somewhere around there um so we'll + + align:start position:0% +17 18 somewhere around there um so we'll + + + align:start position:0% +17 18 somewhere around there um so we'll +call it 18° in summer again relative to + + align:start position:0% +call it 18° in summer again relative to + + + align:start position:0% +call it 18° in summer again relative to +the surface normal and in winter time + + align:start position:0% +the surface normal and in winter time + + + align:start position:0% +the surface normal and in winter time +what is the what does that work out to + + align:start position:0% +what is the what does that work out to + + + align:start position:0% +what is the what does that work out to +be 64 64 a half similar logic right so + + align:start position:0% +be 64 64 a half similar logic right so + + + align:start position:0% +be 64 64 a half similar logic right so +we'll call it 6 5° in Winter good so + + align:start position:0% +we'll call it 6 5° in Winter good so + + + align:start position:0% +we'll call it 6 5° in Winter good so +what does that work out to be in terms + + align:start position:0% +what does that work out to be in terms + + + align:start position:0% +what does that work out to be in terms +of air mass for winter and + + align:start position:0% +of air mass for winter and + + + align:start position:0% +of air mass for winter and +summer quick engineering approximation + + align:start position:0% +summer quick engineering approximation + + + align:start position:0% +summer quick engineering approximation +I'm going to say that in summer it's + + align:start position:0% +I'm going to say that in summer it's + + + align:start position:0% +I'm going to say that in summer it's +approximately air mass one but you can + + align:start position:0% +approximately air mass one but you can + + + align:start position:0% +approximately air mass one but you can +calculate it real quick somebody with a + + align:start position:0% +calculate it real quick somebody with a + + + align:start position:0% +calculate it real quick somebody with a +calculator want to plug those + + align:start position:0% +calculator want to plug those + + + align:start position:0% +calculator want to plug those +in and roughly two in Winter + + align:start position:0% +in and roughly two in Winter + + + align:start position:0% +in and roughly two in Winter +right okay we're going to get into + + align:start position:0% +right okay we're going to get into + + + align:start position:0% +right okay we're going to get into +scattering of light uh in in next + + align:start position:0% +scattering of light uh in in next + + + align:start position:0% +scattering of light uh in in next +lecture actually and we'll see why why + + align:start position:0% +lecture actually and we'll see why why + + + align:start position:0% +lecture actually and we'll see why why +that matters in terms especially of + + align:start position:0% +that matters in terms especially of + + + align:start position:0% +that matters in terms especially of +getting sunburned since the shorter + + align:start position:0% +getting sunburned since the shorter + + + align:start position:0% +getting sunburned since the shorter +wavelengths the ultraviolet are more + + align:start position:0% +wavelengths the ultraviolet are more + + + align:start position:0% +wavelengths the ultraviolet are more +sensitive uh to the path length Okay + + align:start position:0% +sensitive uh to the path length Okay + + + align:start position:0% +sensitive uh to the path length Okay +um good very good so we have a a a a + + align:start position:0% +um good very good so we have a a a a + + + align:start position:0% +um good very good so we have a a a a +pretty much a gut sense now of where the + + align:start position:0% +pretty much a gut sense now of where the + + + align:start position:0% +pretty much a gut sense now of where the +sun is in the sky and as it moves from + + align:start position:0% +sun is in the sky and as it moves from + + + align:start position:0% +sun is in the sky and as it moves from +Summer to Winter from our perspective it + + align:start position:0% +Summer to Winter from our perspective it + + + align:start position:0% +Summer to Winter from our perspective it +follows a little bit of a um I would say + + align:start position:0% +follows a little bit of a um I would say + + + align:start position:0% +follows a little bit of a um I would say +a sinusal path right it stays in summer + + align:start position:0% +a sinusal path right it stays in summer + + + align:start position:0% +a sinusal path right it stays in summer +for a long period of time up here and + + align:start position:0% +for a long period of time up here and + + + align:start position:0% +for a long period of time up here and +then it moves prettyy quickly down here + + align:start position:0% +then it moves prettyy quickly down here + + + align:start position:0% +then it moves prettyy quickly down here +and stays here so it vers this time the + + align:start position:0% +and stays here so it vers this time the + + + align:start position:0% +and stays here so it vers this time the +angle of the Sun in the sky is following + + align:start position:0% +angle of the Sun in the sky is following + + + align:start position:0% +angle of the Sun in the sky is following +a S curve or cosine curve if you will + + align:start position:0% +a S curve or cosine curve if you will + + + align:start position:0% +a S curve or cosine curve if you will +right and so right now the sun is + + align:start position:0% +right and so right now the sun is + + + align:start position:0% +right and so right now the sun is +actually close to the middle we're in + + align:start position:0% +actually close to the middle we're in + + + align:start position:0% +actually close to the middle we're in +September 13th the solstice is coming up + + align:start position:0% +September 13th the solstice is coming up + + + align:start position:0% +September 13th the solstice is coming up +in a week's time and so the slope of + + align:start position:0% +in a week's time and so the slope of + + + align:start position:0% +in a week's time and so the slope of +that sign curve is at a maximum right + + align:start position:0% +that sign curve is at a maximum right + + + align:start position:0% +that sign curve is at a maximum right +about now and so that the amount of time + + align:start position:0% +about now and so that the amount of time + + + align:start position:0% +about now and so that the amount of time +that the day will change in length is + + align:start position:0% +that the day will change in length is + + + align:start position:0% +that the day will change in length is +changing at its greatest point right now + + align:start position:0% +changing at its greatest point right now + + + align:start position:0% +changing at its greatest point right now +in the year and so you really begin to + + align:start position:0% +in the year and so you really begin to + + + align:start position:0% +in the year and so you really begin to +notice it if you start paying attention + + align:start position:0% +notice it if you start paying attention + + + align:start position:0% +notice it if you start paying attention +or if you go to weather.com and start + + align:start position:0% +or if you go to weather.com and start + + + align:start position:0% +or if you go to weather.com and start +looking up uh how long is is today's day + + align:start position:0% +looking up uh how long is is today's day + + + align:start position:0% +looking up uh how long is is today's day +going to last uh when is the sunset + + align:start position:0% +going to last uh when is the sunset + + + align:start position:0% +going to last uh when is the sunset +tomorrow I don't know about you folks + + align:start position:0% +tomorrow I don't know about you folks + + + align:start position:0% +tomorrow I don't know about you folks +but I like to cycle and when I'm uh + + align:start position:0% +but I like to cycle and when I'm uh + + + align:start position:0% +but I like to cycle and when I'm uh +doing my evening rides I'm noticing it + + align:start position:0% +doing my evening rides I'm noticing it + + + align:start position:0% +doing my evening rides I'm noticing it +now that I have to start earli and + + align:start position:0% +now that I have to start earli and + + + align:start position:0% +now that I have to start earli and +earlier if I want to put in say 30 or 40 + + align:start position:0% +earlier if I want to put in say 30 or 40 + + + align:start position:0% +earlier if I want to put in say 30 or 40 +miles I'm not going to be able to make + + align:start position:0% +miles I'm not going to be able to make + + + align:start position:0% +miles I'm not going to be able to make +it home in time so um so that's the uh + + align:start position:0% +it home in time so um so that's the uh + + + align:start position:0% +it home in time so um so that's the uh +that's the Sun and how it relates to you + + align:start position:0% +that's the Sun and how it relates to you + + + align:start position:0% +that's the Sun and how it relates to you +in your daily lives um we're going to + + align:start position:0% +in your daily lives um we're going to + + + align:start position:0% +in your daily lives um we're going to +get uh we're going to get back to this + + align:start position:0% +get uh we're going to get back to this + + + align:start position:0% +get uh we're going to get back to this +in a minute so keep this in mind don't + + align:start position:0% +in a minute so keep this in mind don't + + + align:start position:0% +in a minute so keep this in mind don't +don't don't let it out of your RAM um + + align:start position:0% +don't don't let it out of your RAM um + + + align:start position:0% +don't don't let it out of your RAM um +let's talk about the actual solar + + align:start position:0% +let's talk about the actual solar + + + align:start position:0% +let's talk about the actual solar +Spectrum for a minute uh this is the + + align:start position:0% +Spectrum for a minute uh this is the + + + align:start position:0% +Spectrum for a minute uh this is the +sunlight intensity in some very weird + + align:start position:0% +sunlight intensity in some very weird + + + align:start position:0% +sunlight intensity in some very weird +units we'll get to that in a minute but + + align:start position:0% +units we'll get to that in a minute but + + + align:start position:0% +units we'll get to that in a minute but +think of this in terms sort of like the + + align:start position:0% +think of this in terms sort of like the + + + align:start position:0% +think of this in terms sort of like the +total amount of power in a given + + align:start position:0% +total amount of power in a given + + + align:start position:0% +total amount of power in a given +bandwidth um so the uh wavelength right + + align:start position:0% +bandwidth um so the uh wavelength right + + + align:start position:0% +bandwidth um so the uh wavelength right +here or the power density and a + + align:start position:0% +here or the power density and a + + + align:start position:0% +here or the power density and a +bandwidth the wavelength is the + + align:start position:0% +bandwidth the wavelength is the + + + align:start position:0% +bandwidth the wavelength is the +wavelength of light shown for your + + align:start position:0% +wavelength of light shown for your + + + align:start position:0% +wavelength of light shown for your +convenience here is the visible spectrum + + align:start position:0% +convenience here is the visible spectrum + + + align:start position:0% +convenience here is the visible spectrum +that's what our eye mostly what our eye + + align:start position:0% +that's what our eye mostly what our eye + + + align:start position:0% +that's what our eye mostly what our eye +is able to detect in this uh wavelength + + align:start position:0% +is able to detect in this uh wavelength + + + align:start position:0% +is able to detect in this uh wavelength +range right here and the Sun is emitting + + align:start position:0% +range right here and the Sun is emitting + + + align:start position:0% +range right here and the Sun is emitting +over a much broader range of wavelengths + + align:start position:0% +over a much broader range of wavelengths + + + align:start position:0% +over a much broader range of wavelengths +it's emitting following a black body uh + + align:start position:0% +it's emitting following a black body uh + + + align:start position:0% +it's emitting following a black body uh +black body emission Source at 6,000 + + align:start position:0% +black body emission Source at 6,000 + + + align:start position:0% +black body emission Source at 6,000 +Kelvin and that's in this very difficult + + align:start position:0% +Kelvin and that's in this very difficult + + + align:start position:0% +Kelvin and that's in this very difficult +to see green line right there air mass + + align:start position:0% +to see green line right there air mass + + + align:start position:0% +to see green line right there air mass +zero Spectrum looks like this this red + + align:start position:0% +zero Spectrum looks like this this red + + + align:start position:0% +zero Spectrum looks like this this red +line right here and again letting me + + align:start position:0% +line right here and again letting me + + + align:start position:0% +line right here and again letting me +remind you that the air mass zero is the + + align:start position:0% +remind you that the air mass zero is the + + + align:start position:0% +remind you that the air mass zero is the +light that's falling in the outer + + align:start position:0% +light that's falling in the outer + + + align:start position:0% +light that's falling in the outer +atmosphere there is no Earth atmospheric + + align:start position:0% +atmosphere there is no Earth atmospheric + + + align:start position:0% +atmosphere there is no Earth atmospheric +absorption yet why do we have these + + align:start position:0% +absorption yet why do we have these + + + align:start position:0% +absorption yet why do we have these +little lines here you see it's not a + + align:start position:0% +little lines here you see it's not a + + + align:start position:0% +little lines here you see it's not a +perfect black body we have some I'll + + align:start position:0% +perfect black body we have some I'll + + + align:start position:0% +perfect black body we have some I'll +give you a hint absorption lines where + + align:start position:0% +give you a hint absorption lines where + + + align:start position:0% +give you a hint absorption lines where +where is that light being absorbed is it + + align:start position:0% +where is that light being absorbed is it + + + align:start position:0% +where is that light being absorbed is it +is it the ether between the Earth and + + align:start position:0% +is it the ether between the Earth and + + + align:start position:0% +is it the ether between the Earth and +the Sun there's no ether between the + + align:start position:0% +the Sun there's no ether between the + + + align:start position:0% +the Sun there's no ether between the +Earth and so where where's that light + + align:start position:0% +Earth and so where where's that light + + + align:start position:0% +Earth and so where where's that light +being absorbed hydrogen ions in the sun + + align:start position:0% +being absorbed hydrogen ions in the sun + + + align:start position:0% +being absorbed hydrogen ions in the sun +itself right so these are absorption + + align:start position:0% +itself right so these are absorption + + + align:start position:0% +itself right so these are absorption +events occurring in the uh solar + + align:start position:0% +events occurring in the uh solar + + + align:start position:0% +events occurring in the uh solar +atmosphere and now if we do air mass one + + align:start position:0% +atmosphere and now if we do air mass one + + + align:start position:0% +atmosphere and now if we do air mass one +or 1.5 let's U push it up a little bit + + align:start position:0% +or 1.5 let's U push it up a little bit + + + align:start position:0% +or 1.5 let's U push it up a little bit +from air mass zero this is now uh + + align:start position:0% +from air mass zero this is now uh + + + align:start position:0% +from air mass zero this is now uh +passing through an angle somewhere + + align:start position:0% +passing through an angle somewhere + + + align:start position:0% +passing through an angle somewhere +around + + align:start position:0% +around + + + align:start position:0% +around +60° uh now what do we have we have um + + align:start position:0% +60° uh now what do we have we have um + + + align:start position:0% +60° uh now what do we have we have um +several absorption lines occurring right + + align:start position:0% +several absorption lines occurring right + + + align:start position:0% +several absorption lines occurring right +and these correspond to absorption + + align:start position:0% +and these correspond to absorption + + + align:start position:0% +and these correspond to absorption +events + + align:start position:0% +events + + + align:start position:0% +events +where in the Earth's atmosphere exactly + + align:start position:0% +where in the Earth's atmosphere exactly + + + align:start position:0% +where in the Earth's atmosphere exactly +and so we can attribute each of these + + align:start position:0% +and so we can attribute each of these + + + align:start position:0% +and so we can attribute each of these +little absorption lines here to a + + align:start position:0% +little absorption lines here to a + + + align:start position:0% +little absorption lines here to a +particular usually it's a molecule uh in + + align:start position:0% +particular usually it's a molecule uh in + + + align:start position:0% +particular usually it's a molecule uh in +the Earth's atmosphere note the + + align:start position:0% +the Earth's atmosphere note the + + + align:start position:0% +the Earth's atmosphere note the +sensitivity of the human eye in Black + + align:start position:0% +sensitivity of the human eye in Black + + + align:start position:0% +sensitivity of the human eye in Black +right here and how well matched it is to + + align:start position:0% +right here and how well matched it is to + + + align:start position:0% +right here and how well matched it is to +the air mass one air mass 1.5 Spectrum + + align:start position:0% +the air mass one air mass 1.5 Spectrum + + + align:start position:0% +the air mass one air mass 1.5 Spectrum +that's pretty cool that's pretty cool + + align:start position:0% +that's pretty cool that's pretty cool + + + align:start position:0% +that's pretty cool that's pretty cool +okay so so there you have the the + + align:start position:0% +okay so so there you have the the + + + align:start position:0% +okay so so there you have the the +Spectrum let's get to these units of of + + align:start position:0% +Spectrum let's get to these units of of + + + align:start position:0% +Spectrum let's get to these units of of +of power density per bandwidth for a + + align:start position:0% +of power density per bandwidth for a + + + align:start position:0% +of power density per bandwidth for a +second the way to think about those + + align:start position:0% +second the way to think about those + + + align:start position:0% +second the way to think about those +units is as follows kilowatts per meter + + align:start position:0% +units is as follows kilowatts per meter + + + align:start position:0% +units is as follows kilowatts per meter +squar okay I get that it's amount of + + align:start position:0% +squar okay I get that it's amount of + + + align:start position:0% +squar okay I get that it's amount of +power following falling on a a unit area + + align:start position:0% +power following falling on a a unit area + + + align:start position:0% +power following falling on a a unit area +per Micron uh the reason it's normalized + + align:start position:0% +per Micron uh the reason it's normalized + + + align:start position:0% +per Micron uh the reason it's normalized +per Micron is because the wavelength + + align:start position:0% +per Micron is because the wavelength + + + align:start position:0% +per Micron is because the wavelength +units right here is in microns and if + + align:start position:0% +units right here is in microns and if + + + align:start position:0% +units right here is in microns and if +you take the product of the two it makes + + align:start position:0% +you take the product of the two it makes + + + align:start position:0% +you take the product of the two it makes +it pretty easy to calculate the total + + align:start position:0% +it pretty easy to calculate the total + + + align:start position:0% +it pretty easy to calculate the total +power density right so if you want to + + align:start position:0% +power density right so if you want to + + + align:start position:0% +power density right so if you want to +calculate the power density the total uh + + align:start position:0% +calculate the power density the total uh + + + align:start position:0% +calculate the power density the total uh +watts per square meter falling on the + + align:start position:0% +watts per square meter falling on the + + + align:start position:0% +watts per square meter falling on the +earth say between 0.5 and one micron you + + align:start position:0% +earth say between 0.5 and one micron you + + + align:start position:0% +earth say between 0.5 and one micron you +can calculate the total amount of Power + + align:start position:0% +can calculate the total amount of Power + + + align:start position:0% +can calculate the total amount of Power +by multiplying one versus the other so + + align:start position:0% +by multiplying one versus the other so + + + align:start position:0% +by multiplying one versus the other so +that's why there in this weird unit + + align:start position:0% +that's why there in this weird unit + + + align:start position:0% +that's why there in this weird unit +right here it's to help you perform + + align:start position:0% +right here it's to help you perform + + + align:start position:0% +right here it's to help you perform +calculations like the ones you'll do in + + align:start position:0% +calculations like the ones you'll do in + + + align:start position:0% +calculations like the ones you'll do in +your homework like the ones you'll do + + align:start position:0% +your homework like the ones you'll do + + + align:start position:0% +your homework like the ones you'll do +through your class project and so forth + + align:start position:0% +through your class project and so forth + + + align:start position:0% +through your class project and so forth +and it strikes a little bit odd the + + align:start position:0% +and it strikes a little bit odd the + + + align:start position:0% +and it strikes a little bit odd the +first time you look at it but it begins + + align:start position:0% +first time you look at it but it begins + + + align:start position:0% +first time you look at it but it begins +making sense and you're appreciative it + + align:start position:0% +making sense and you're appreciative it + + + align:start position:0% +making sense and you're appreciative it +after a while um there are standard + + align:start position:0% +after a while um there are standard + + + align:start position:0% +after a while um there are standard +Spectra they're standard reference + + align:start position:0% +Spectra they're standard reference + + + align:start position:0% +Spectra they're standard reference +Spectra sure you can go outside and and + + align:start position:0% +Spectra sure you can go outside and and + + + align:start position:0% +Spectra sure you can go outside and and +and using a uh some form of spectometer + + align:start position:0% +and using a uh some form of spectometer + + + align:start position:0% +and using a uh some form of spectometer +you can measure the uh the incident + + align:start position:0% +you can measure the uh the incident + + + align:start position:0% +you can measure the uh the incident +solar radiation and map out the + + align:start position:0% +solar radiation and map out the + + + align:start position:0% +solar radiation and map out the +spectular radiance as a function of + + align:start position:0% +spectular radiance as a function of + + + align:start position:0% +spectular radiance as a function of +wavelength um in terms of planning or uh + + align:start position:0% +wavelength um in terms of planning or uh + + + align:start position:0% +wavelength um in terms of planning or uh +communicating with other scientists we + + align:start position:0% +communicating with other scientists we + + + align:start position:0% +communicating with other scientists we +typically refer to standards we we use + + align:start position:0% +typically refer to standards we we use + + + align:start position:0% +typically refer to standards we we use +common yard sticks common metrics and + + align:start position:0% +common yard sticks common metrics and + + + align:start position:0% +common yard sticks common metrics and +that facilitates communication avoids + + align:start position:0% +that facilitates communication avoids + + + align:start position:0% +that facilitates communication avoids +ambiguity avoids misunderstanding and so + + align:start position:0% +ambiguity avoids misunderstanding and so + + + align:start position:0% +ambiguity avoids misunderstanding and so +these standards right here these asms uh + + align:start position:0% +these standards right here these asms uh + + + align:start position:0% +these standards right here these asms uh +refer to the particular uh standards + + align:start position:0% +refer to the particular uh standards + + + align:start position:0% +refer to the particular uh standards +that are used for those solar Spectra + + align:start position:0% +that are used for those solar Spectra + + + align:start position:0% +that are used for those solar Spectra +and in your reporting online material at + + align:start position:0% +and in your reporting online material at + + + align:start position:0% +and in your reporting online material at +the very end of the lecture slides + + align:start position:0% +the very end of the lecture slides + + + align:start position:0% +the very end of the lecture slides +online we go into some more detail uh + + align:start position:0% +online we go into some more detail uh + + + align:start position:0% +online we go into some more detail uh +regarding that for those who are + + align:start position:0% +regarding that for those who are + + + align:start position:0% +regarding that for those who are +interested so again um these little + + align:start position:0% +interested so again um these little + + + align:start position:0% +interested so again um these little +absorption lines here correspond to + + align:start position:0% +absorption lines here correspond to + + + align:start position:0% +absorption lines here correspond to +specific atmospheric events uh + + align:start position:0% +specific atmospheric events uh + + + align:start position:0% +specific atmospheric events uh +interactions of that particular + + align:start position:0% +interactions of that particular + + + align:start position:0% +interactions of that particular +wavelength of light with some molecule + + align:start position:0% +wavelength of light with some molecule + + + align:start position:0% +wavelength of light with some molecule +usually uh in the atmosphere um we can + + align:start position:0% +usually uh in the atmosphere um we can + + + align:start position:0% +usually uh in the atmosphere um we can +as well have generalized attenuation uh + + align:start position:0% +as well have generalized attenuation uh + + + align:start position:0% +as well have generalized attenuation uh +due to other scattering mechanisms + + align:start position:0% +due to other scattering mechanisms + + + align:start position:0% +due to other scattering mechanisms +notice right here in the short + + align:start position:0% +notice right here in the short + + + align:start position:0% +notice right here in the short +wavelengths what's happening + + align:start position:0% +wavelengths what's happening + + + align:start position:0% +wavelengths what's happening +um from the red to the blue this light + + align:start position:0% +um from the red to the blue this light + + + align:start position:0% +um from the red to the blue this light +is particularly affected we have a sharp + + align:start position:0% +is particularly affected we have a sharp + + + align:start position:0% +is particularly affected we have a sharp +drop in the shorter wavelengths and it's + + align:start position:0% +drop in the shorter wavelengths and it's + + + align:start position:0% +drop in the shorter wavelengths and it's +it grows sharper the shorter in + + align:start position:0% +it grows sharper the shorter in + + + align:start position:0% +it grows sharper the shorter in +wavelength you go so the attenuation due + + align:start position:0% +wavelength you go so the attenuation due + + + align:start position:0% +wavelength you go so the attenuation due +to passing through the + + align:start position:0% +to passing through the + + + align:start position:0% +to passing through the +atmosphere grows or increases uh the + + align:start position:0% +atmosphere grows or increases uh the + + + align:start position:0% +atmosphere grows or increases uh the +shorter and wavelength you go and this + + align:start position:0% +shorter and wavelength you go and this + + + align:start position:0% +shorter and wavelength you go and this +is a a process generally called ra + + align:start position:0% +is a a process generally called ra + + + align:start position:0% +is a a process generally called ra +scattering um and there is a wavelength + + align:start position:0% +scattering um and there is a wavelength + + + align:start position:0% +scattering um and there is a wavelength +to the fourth dependence so as you uh as + + align:start position:0% +to the fourth dependence so as you uh as + + + align:start position:0% +to the fourth dependence so as you uh as +you go shorter and shorter in wavelength + + align:start position:0% +you go shorter and shorter in wavelength + + + align:start position:0% +you go shorter and shorter in wavelength +uh the likelihood or probability of + + align:start position:0% +uh the likelihood or probability of + + + align:start position:0% +uh the likelihood or probability of +scattering will increase why is that + + align:start position:0% +scattering will increase why is that + + + align:start position:0% +scattering will increase why is that +pertinent to us well now you can answer + + align:start position:0% +pertinent to us well now you can answer + + + align:start position:0% +pertinent to us well now you can answer +that little child who walks up to you in + + align:start position:0% +that little child who walks up to you in + + + align:start position:0% +that little child who walks up to you in +the shopping mall and says why is the + + align:start position:0% +the shopping mall and says why is the + + + align:start position:0% +the shopping mall and says why is the +sky blue you say well um there is this + + align:start position:0% +sky blue you say well um there is this + + + align:start position:0% +sky blue you say well um there is this +elastic scattering mechanism of + + align:start position:0% +elastic scattering mechanism of + + + align:start position:0% +elastic scattering mechanism of +electromagnetic radiation whereby uh in + + align:start position:0% +electromagnetic radiation whereby uh in + + + align:start position:0% +electromagnetic radiation whereby uh in +a broads spectral event such as a sun + + align:start position:0% +a broads spectral event such as a sun + + + align:start position:0% +a broads spectral event such as a sun +black body emission uh we have the + + align:start position:0% +black body emission uh we have the + + + align:start position:0% +black body emission uh we have the +shorter wavelengths that are scattered + + align:start position:0% +shorter wavelengths that are scattered + + + align:start position:0% +shorter wavelengths that are scattered +more and that's why when we look away + + align:start position:0% +more and that's why when we look away + + + align:start position:0% +more and that's why when we look away +from the sun in the other direction we + + align:start position:0% +from the sun in the other direction we + + + align:start position:0% +from the sun in the other direction we +see those shorter wavelengths that are + + align:start position:0% +see those shorter wavelengths that are + + + align:start position:0% +see those shorter wavelengths that are +scattered back to us that is pertinent + + align:start position:0% +scattered back to us that is pertinent + + + align:start position:0% +scattered back to us that is pertinent +for two reasons a makes the sky look + + align:start position:0% +for two reasons a makes the sky look + + + align:start position:0% +for two reasons a makes the sky look +blue secondly it's not only the uh short + + align:start position:0% +blue secondly it's not only the uh short + + + align:start position:0% +blue secondly it's not only the uh short +wavelengths in blue light that we're + + align:start position:0% +wavelengths in blue light that we're + + + align:start position:0% +wavelengths in blue light that we're +worried about but also the ultraviolet + + align:start position:0% +worried about but also the ultraviolet + + + align:start position:0% +worried about but also the ultraviolet +radiation right so even on a cloudy day + + align:start position:0% +radiation right so even on a cloudy day + + + align:start position:0% +radiation right so even on a cloudy day +if there is a a few uh open patches and + + align:start position:0% +if there is a a few uh open patches and + + + align:start position:0% +if there is a a few uh open patches and +you can get uh scattered light coming in + + align:start position:0% +you can get uh scattered light coming in + + + align:start position:0% +you can get uh scattered light coming in +you can still get sunburned and secondly + + align:start position:0% +you can still get sunburned and secondly + + + align:start position:0% +you can still get sunburned and secondly +um there is a very strong dependence on + + align:start position:0% +um there is a very strong dependence on + + + align:start position:0% +um there is a very strong dependence on +the path length the optical path length + + align:start position:0% +the path length the optical path length + + + align:start position:0% +the path length the optical path length +the air mass right so if you go further + + align:start position:0% +the air mass right so if you go further + + + align:start position:0% +the air mass right so if you go further +north in latitudes where your air mass + + align:start position:0% +north in latitudes where your air mass + + + align:start position:0% +north in latitudes where your air mass +increases right because now if you think + + align:start position:0% +increases right because now if you think + + + align:start position:0% +increases right because now if you think +about the atmosphere as being kind of a + + align:start position:0% +about the atmosphere as being kind of a + + + align:start position:0% +about the atmosphere as being kind of a +flat just give me approximation for a + + align:start position:0% +flat just give me approximation for a + + + align:start position:0% +flat just give me approximation for a +minute if you think of the Earth being + + align:start position:0% +minute if you think of the Earth being + + + align:start position:0% +minute if you think of the Earth being +flat and the atmosphere being flat now + + align:start position:0% +flat and the atmosphere being flat now + + + align:start position:0% +flat and the atmosphere being flat now +the path length in winter is much much + + align:start position:0% +the path length in winter is much much + + + align:start position:0% +the path length in winter is much much +greater than the path length in summer + + align:start position:0% +greater than the path length in summer + + + align:start position:0% +greater than the path length in summer +same Sun just different path length + + align:start position:0% +same Sun just different path length + + + align:start position:0% +same Sun just different path length +you're much likely much more likely to + + align:start position:0% +you're much likely much more likely to + + + align:start position:0% +you're much likely much more likely to +get sunburned in summer than you are in + + align:start position:0% +get sunburned in summer than you are in + + + align:start position:0% +get sunburned in summer than you are in +winter because the path length is a lot + + align:start position:0% +winter because the path length is a lot + + + align:start position:0% +winter because the path length is a lot +shorter and the amount of short + + align:start position:0% +shorter and the amount of short + + + align:start position:0% +shorter and the amount of short +wavelength ultraviolet radiation that + + align:start position:0% +wavelength ultraviolet radiation that + + + align:start position:0% +wavelength ultraviolet radiation that +will be scattered away is going to be + + align:start position:0% +will be scattered away is going to be + + + align:start position:0% +will be scattered away is going to be +less in the summer than in Winter that's + + align:start position:0% +less in the summer than in Winter that's + + + align:start position:0% +less in the summer than in Winter that's +also why if you go south and latitude + + align:start position:0% +also why if you go south and latitude + + + align:start position:0% +also why if you go south and latitude +for example from here say to Miami your + + align:start position:0% +for example from here say to Miami your + + + align:start position:0% +for example from here say to Miami your +incidence of getting sunburn is a lot + + align:start position:0% +incidence of getting sunburn is a lot + + + align:start position:0% +incidence of getting sunburn is a lot +greater a lot more than the total + + align:start position:0% +greater a lot more than the total + + + align:start position:0% +greater a lot more than the total +increase of the visible portion of the + + align:start position:0% +increase of the visible portion of the + + + align:start position:0% +increase of the visible portion of the +spectrum so the sun might not look that + + align:start position:0% +spectrum so the sun might not look that + + + align:start position:0% +spectrum so the sun might not look that +different to you but you'll your + + align:start position:0% +different to you but you'll your + + + align:start position:0% +different to you but you'll your +incidence of of sunburn events goes up + + align:start position:0% +incidence of of sunburn events goes up + + + align:start position:0% +incidence of of sunburn events goes up +quite a bit and that is due to ra + + align:start position:0% +quite a bit and that is due to ra + + + align:start position:0% +quite a bit and that is due to ra +scattering and now by this point the + + align:start position:0% +scattering and now by this point the + + + align:start position:0% +scattering and now by this point the +little child has already run crying back + + align:start position:0% +little child has already run crying back + + + align:start position:0% +little child has already run crying back +to the parent but you have a full + + align:start position:0% +to the parent but you have a full + + + align:start position:0% +to the parent but you have a full +satisfaction of knowing how the universe + + align:start position:0% +satisfaction of knowing how the universe + + + align:start position:0% +satisfaction of knowing how the universe +around you is put together and that that + + align:start position:0% +around you is put together and that that + + + align:start position:0% +around you is put together and that that +actually was a pretty deep problem it + + align:start position:0% +actually was a pretty deep problem it + + + align:start position:0% +actually was a pretty deep problem it +took a lot long time for at least + + align:start position:0% +took a lot long time for at least + + + align:start position:0% +took a lot long time for at least +European scientists to to crack that nut + + align:start position:0% +European scientists to to crack that nut + + + align:start position:0% +European scientists to to crack that nut +and figure out what was going + + align:start position:0% +and figure out what was going + + + align:start position:0% +and figure out what was going +on um describe how solar installation + + align:start position:0% +on um describe how solar installation + + + align:start position:0% +on um describe how solar installation +maps are made and used them to estimate + + align:start position:0% +maps are made and used them to estimate + + + align:start position:0% +maps are made and used them to estimate +the local solar resource so we have + + align:start position:0% +the local solar resource so we have + + + align:start position:0% +the local solar resource so we have +Metrology we have techniques that we can + + align:start position:0% +Metrology we have techniques that we can + + + align:start position:0% +Metrology we have techniques that we can +use to measure uh the amount of sunlight + + align:start position:0% +use to measure uh the amount of sunlight + + + align:start position:0% +use to measure uh the amount of sunlight +that is out there and now we want to + + align:start position:0% +that is out there and now we want to + + + align:start position:0% +that is out there and now we want to +apply those in some systematic fashion + + align:start position:0% +apply those in some systematic fashion + + + align:start position:0% +apply those in some systematic fashion +to measure the average solar resource + + align:start position:0% +to measure the average solar resource + + + align:start position:0% +to measure the average solar resource +around the planet uh including the + + align:start position:0% +around the planet uh including the + + + align:start position:0% +around the planet uh including the +oceans and then use that information to + + align:start position:0% +oceans and then use that information to + + + align:start position:0% +oceans and then use that information to +estimate later on uh the land area + + align:start position:0% +estimate later on uh the land area + + + align:start position:0% +estimate later on uh the land area +needed or the size of the array or how + + align:start position:0% +needed or the size of the array or how + + + align:start position:0% +needed or the size of the array or how +many cells we're going to have to string + + align:start position:0% +many cells we're going to have to string + + + align:start position:0% +many cells we're going to have to string +together based on the solar resource + + align:start position:0% +together based on the solar resource + + + align:start position:0% +together based on the solar resource +locally so how are these insulation Maps + + align:start position:0% +locally so how are these insulation Maps + + + align:start position:0% +locally so how are these insulation Maps +made these maps that we'll use as + + align:start position:0% +made these maps that we'll use as + + + align:start position:0% +made these maps that we'll use as +Engineers to size our systems first off + + align:start position:0% +Engineers to size our systems first off + + + align:start position:0% +Engineers to size our systems first off +let me Define insulation this is not + + align:start position:0% +let me Define insulation this is not + + + align:start position:0% +let me Define insulation this is not +insulation as in stuff you put around + + align:start position:0% +insulation as in stuff you put around + + + align:start position:0% +insulation as in stuff you put around +the house to keep the heat from going + + align:start position:0% +the house to keep the heat from going + + + align:start position:0% +the house to keep the heat from going +out this is insulation with an O uh a + + align:start position:0% +out this is insulation with an O uh a + + + align:start position:0% +out this is insulation with an O uh a +short hand for incoming solar radiation + + align:start position:0% +short hand for incoming solar radiation + + + align:start position:0% +short hand for incoming solar radiation +Insulation at the top there it's + + align:start position:0% +Insulation at the top there it's + + + align:start position:0% +Insulation at the top there it's +typically given in units of energy per + + align:start position:0% +typically given in units of energy per + + + align:start position:0% +typically given in units of energy per +unit area per unit time + + align:start position:0% +unit area per unit time + + + align:start position:0% +unit area per unit time +so kilowatt hours that's energy per + + align:start position:0% +so kilowatt hours that's energy per + + + align:start position:0% +so kilowatt hours that's energy per +meter squar per day and it's helpful + + align:start position:0% +meter squar per day and it's helpful + + + align:start position:0% +meter squar per day and it's helpful +when designing or projecting these PB + + align:start position:0% +when designing or projecting these PB + + + align:start position:0% +when designing or projecting these PB +systems and it's affected by a bunch of + + align:start position:0% +systems and it's affected by a bunch of + + + align:start position:0% +systems and it's affected by a bunch of +stuff which we'll get to over the next + + align:start position:0% +stuff which we'll get to over the next + + + align:start position:0% +stuff which we'll get to over the next +few slides so we can measure insulation + + align:start position:0% +few slides so we can measure insulation + + + align:start position:0% +few slides so we can measure insulation +from the ground that's a Surefire way to + + align:start position:0% +from the ground that's a Surefire way to + + + align:start position:0% +from the ground that's a Surefire way to +do it um this right here is a + + align:start position:0% +do it um this right here is a + + + align:start position:0% +do it um this right here is a +pyrometer pyro Fire Sun Ano on top of + + align:start position:0% +pyrometer pyro Fire Sun Ano on top of + + + align:start position:0% +pyrometer pyro Fire Sun Ano on top of +right so anode cathode Kata under Anna + + align:start position:0% +right so anode cathode Kata under Anna + + + align:start position:0% +right so anode cathode Kata under Anna +above catatonic under right okay um so + + align:start position:0% +above catatonic under right okay um so + + + align:start position:0% +above catatonic under right okay um so +pyrometer so it's basically measuring + + align:start position:0% +pyrometer so it's basically measuring + + + align:start position:0% +pyrometer so it's basically measuring +the sun above right it's measuring the + + align:start position:0% +the sun above right it's measuring the + + + align:start position:0% +the sun above right it's measuring the +the sunlight Above This is a full + + align:start position:0% +the sunlight Above This is a full + + + align:start position:0% +the sunlight Above This is a full +hemisphere um measuring the sunlight + + align:start position:0% +hemisphere um measuring the sunlight + + + align:start position:0% +hemisphere um measuring the sunlight +coming in from all angles there's a + + align:start position:0% +coming in from all angles there's a + + + align:start position:0% +coming in from all angles there's a +small little sensor right here it's + + align:start position:0% +small little sensor right here it's + + + align:start position:0% +small little sensor right here it's +lying flat and that uh glass is + + align:start position:0% +lying flat and that uh glass is + + + align:start position:0% +lying flat and that uh glass is +essentially allowing the light from + + align:start position:0% +essentially allowing the light from + + + align:start position:0% +essentially allowing the light from +different angles to get in uh to the + + align:start position:0% +different angles to get in uh to the + + + align:start position:0% +different angles to get in uh to the +sensor and this is a a very narrow solid + + align:start position:0% +sensor and this is a a very narrow solid + + + align:start position:0% +sensor and this is a a very narrow solid +angle the sky it's probably just looking + + align:start position:0% +angle the sky it's probably just looking + + + align:start position:0% +angle the sky it's probably just looking +at the sun or in a particular direction + + align:start position:0% +at the sun or in a particular direction + + + align:start position:0% +at the sun or in a particular direction +rather plus or minus two and a half + + align:start position:0% +rather plus or minus two and a half + + + align:start position:0% +rather plus or minus two and a half +degrees in either direction so it's a + + align:start position:0% +degrees in either direction so it's a + + + align:start position:0% +degrees in either direction so it's a +very limited solid angle of the sky um + + align:start position:0% +very limited solid angle of the sky um + + + align:start position:0% +very limited solid angle of the sky um +this one over here would be more + + align:start position:0% +this one over here would be more + + + align:start position:0% +this one over here would be more +appropriate say for a flat panel that's + + align:start position:0% +appropriate say for a flat panel that's + + + align:start position:0% +appropriate say for a flat panel that's +receiving scattered light coming in at + + align:start position:0% +receiving scattered light coming in at + + + align:start position:0% +receiving scattered light coming in at +all angles this one over here would be + + align:start position:0% +all angles this one over here would be + + + align:start position:0% +all angles this one over here would be +more appropriate for a tracking system + + align:start position:0% +more appropriate for a tracking system + + + align:start position:0% +more appropriate for a tracking system +especially a concentrator system that + + align:start position:0% +especially a concentrator system that + + + align:start position:0% +especially a concentrator system that +has Optics that only accept light in + + align:start position:0% +has Optics that only accept light in + + + align:start position:0% +has Optics that only accept light in +from a very limited solid angle let's + + align:start position:0% +from a very limited solid angle let's + + + align:start position:0% +from a very limited solid angle let's +imagine you have a lens that has to have + + align:start position:0% +imagine you have a lens that has to have + + + align:start position:0% +imagine you have a lens that has to have +light incident to it to focus it on the + + align:start position:0% +light incident to it to focus it on the + + + align:start position:0% +light incident to it to focus it on the +right spot and if the sun moves in the + + align:start position:0% +right spot and if the sun moves in the + + + align:start position:0% +right spot and if the sun moves in the +wrong spot or the put it another way if + + align:start position:0% +wrong spot or the put it another way if + + + align:start position:0% +wrong spot or the put it another way if +the lens is in the wrong position + + align:start position:0% +the lens is in the wrong position + + + align:start position:0% +the lens is in the wrong position +relative to the incident solar radiation + + align:start position:0% +relative to the incident solar radiation + + + align:start position:0% +relative to the incident solar radiation +the light is being focused off of the + + align:start position:0% +the light is being focused off of the + + + align:start position:0% +the light is being focused off of the +solar cell and it doesn't produce any + + align:start position:0% +solar cell and it doesn't produce any + + + align:start position:0% +solar cell and it doesn't produce any +power so this is a system that's used + + align:start position:0% +power so this is a system that's used + + + align:start position:0% +power so this is a system that's used +for um uh measuring the direct solar + + align:start position:0% +for um uh measuring the direct solar + + + align:start position:0% +for um uh measuring the direct solar +Spectrum which will be useful for + + align:start position:0% +Spectrum which will be useful for + + + align:start position:0% +Spectrum which will be useful for +calculating the total output from + + align:start position:0% +calculating the total output from + + + align:start position:0% +calculating the total output from +concentrator systems and this + + align:start position:0% +concentrator systems and this + + + align:start position:0% +concentrator systems and this +pyranometer over here is useful for flat + + align:start position:0% +pyranometer over here is useful for flat + + + align:start position:0% +pyranometer over here is useful for flat +panel + + align:start position:0% +panel + + + align:start position:0% +panel +systems and uh we can also measure the + + align:start position:0% +systems and uh we can also measure the + + + align:start position:0% +systems and uh we can also measure the +total amount of incident solar radiation + + align:start position:0% +total amount of incident solar radiation + + + align:start position:0% +total amount of incident solar radiation +total amount of insulation from the sky + + align:start position:0% +total amount of insulation from the sky + + + align:start position:0% +total amount of insulation from the sky +using satellite imagery uh this is an + + align:start position:0% +using satellite imagery uh this is an + + + align:start position:0% +using satellite imagery uh this is an +example of a measurement uh and this + + align:start position:0% +example of a measurement uh and this + + + align:start position:0% +example of a measurement uh and this +right here is insulation average + + align:start position:0% +right here is insulation average + + + align:start position:0% +right here is insulation average +insulation from 0 to 550 watts per + + align:start position:0% +insulation from 0 to 550 watts per + + + align:start position:0% +insulation from 0 to 550 watts per +square meter um taken from a NASA + + align:start position:0% +square meter um taken from a NASA + + + align:start position:0% +square meter um taken from a NASA +satellite uh with the NASA Earth + + align:start position:0% +satellite uh with the NASA Earth + + + align:start position:0% +satellite uh with the NASA Earth +Observatory very cool website great + + align:start position:0% +Observatory very cool website great + + + align:start position:0% +Observatory very cool website great +place to spend a Friday night if you're + + align:start position:0% +place to spend a Friday night if you're + + + align:start position:0% +place to spend a Friday night if you're +you're done a plans just uh log on here + + align:start position:0% +you're done a plans just uh log on here + + + align:start position:0% +you're done a plans just uh log on here +and bunches of maps from snow cover to + + align:start position:0% +and bunches of maps from snow cover to + + + align:start position:0% +and bunches of maps from snow cover to +population density to CO2 being emitted + + align:start position:0% +population density to CO2 being emitted + + + align:start position:0% +population density to CO2 being emitted +to wildfires around the planet anything + + align:start position:0% +to wildfires around the planet anything + + + align:start position:0% +to wildfires around the planet anything +that a satellite can measure their + + align:start position:0% +that a satellite can measure their + + + align:start position:0% +that a satellite can measure their +measuring and um the insulation value is + + align:start position:0% +measuring and um the insulation value is + + + align:start position:0% +measuring and um the insulation value is +one of them um and so we have data from + + align:start position:0% +one of them um and so we have data from + + + align:start position:0% +one of them um and so we have data from +uh you know from various points this is + + align:start position:0% +uh you know from various points this is + + + align:start position:0% +uh you know from various points this is +the insulation in January so in January + + align:start position:0% +the insulation in January so in January + + + align:start position:0% +the insulation in January so in January +um it's the southern hemisphere's summer + + align:start position:0% +um it's the southern hemisphere's summer + + + align:start position:0% +um it's the southern hemisphere's summer +the northern hemisphere's winter and as + + align:start position:0% +the northern hemisphere's winter and as + + + align:start position:0% +the northern hemisphere's winter and as +a result we have less insulation up + + align:start position:0% +a result we have less insulation up + + + align:start position:0% +a result we have less insulation up +north we're in the Blues in the southern + + align:start position:0% +north we're in the Blues in the southern + + + align:start position:0% +north we're in the Blues in the southern +hemisphere is more in the Reds and of + + align:start position:0% +hemisphere is more in the Reds and of + + + align:start position:0% +hemisphere is more in the Reds and of +course the tide turns in July we have um + + align:start position:0% +course the tide turns in July we have um + + + align:start position:0% +course the tide turns in July we have um +we have our summer and the southern + + align:start position:0% +we have our summer and the southern + + + align:start position:0% +we have our summer and the southern +hemisphere has their winter and the poor + + align:start position:0% +hemisphere has their winter and the poor + + + align:start position:0% +hemisphere has their winter and the poor +folks here in Antarctica have nothing so + + align:start position:0% +folks here in Antarctica have nothing so + + + align:start position:0% +folks here in Antarctica have nothing so +um a couple of things to note just + + align:start position:0% +um a couple of things to note just + + + align:start position:0% +um a couple of things to note just +already straight off the bat we're + + align:start position:0% +already straight off the bat we're + + + align:start position:0% +already straight off the bat we're +noticing that there's uh in general + + align:start position:0% +noticing that there's uh in general + + + align:start position:0% +noticing that there's uh in general +higher insulation near the equator the + + align:start position:0% +higher insulation near the equator the + + + align:start position:0% +higher insulation near the equator the +equator passing right through here uh + + align:start position:0% +equator passing right through here uh + + + align:start position:0% +equator passing right through here uh +right approximately fun fact small City + + align:start position:0% +right approximately fun fact small City + + + align:start position:0% +right approximately fun fact small City +up there in the north of Brazil there's + + align:start position:0% +up there in the north of Brazil there's + + + align:start position:0% +up there in the north of Brazil there's +a soccer field that is half in the north + + align:start position:0% +a soccer field that is half in the north + + + align:start position:0% +a soccer field that is half in the north +and half in the South anyway um that's + + align:start position:0% +and half in the South anyway um that's + + + align:start position:0% +and half in the South anyway um that's +neither here nor there we have uh + + align:start position:0% +neither here nor there we have uh + + + align:start position:0% +neither here nor there we have uh +rainforests up here in the north of + + align:start position:0% +rainforests up here in the north of + + + align:start position:0% +rainforests up here in the north of +Brazil central Africa and here in + + align:start position:0% +Brazil central Africa and here in + + + align:start position:0% +Brazil central Africa and here in +Southeast Asia and even when the sun is + + align:start position:0% +Southeast Asia and even when the sun is + + + align:start position:0% +Southeast Asia and even when the sun is +directly overhead those clouds are + + align:start position:0% +directly overhead those clouds are + + + align:start position:0% +directly overhead those clouds are +preventing some of the insul sunlight + + align:start position:0% +preventing some of the insul sunlight + + + align:start position:0% +preventing some of the insul sunlight +from getting in and that's why right at + + align:start position:0% +from getting in and that's why right at + + + align:start position:0% +from getting in and that's why right at +the equator itself we typically have + + align:start position:0% +the equator itself we typically have + + + align:start position:0% +the equator itself we typically have +less insulation than we do in the + + align:start position:0% +less insulation than we do in the + + + align:start position:0% +less insulation than we do in the +tropics a Tropic of Capricorn Tropic of + + align:start position:0% +tropics a Tropic of Capricorn Tropic of + + + align:start position:0% +tropics a Tropic of Capricorn Tropic of +Cancer Tropic of uh Capricorn running + + align:start position:0% +Cancer Tropic of uh Capricorn running + + + align:start position:0% +Cancer Tropic of uh Capricorn running +straight through S Paulo Brazil Tropic + + align:start position:0% +straight through S Paulo Brazil Tropic + + + align:start position:0% +straight through S Paulo Brazil Tropic +of Cancer running through Key West just + + align:start position:0% +of Cancer running through Key West just + + + align:start position:0% +of Cancer running through Key West just +to situate yourselves and the Tropics + + align:start position:0% +to situate yourselves and the Tropics + + + align:start position:0% +to situate yourselves and the Tropics +are how far away from the + + align:start position:0% +are how far away from the + + + align:start position:0% +are how far away from the +equator right okay 23 and a half good + + align:start position:0% +equator right okay 23 and a half good + + + align:start position:0% +equator right okay 23 and a half good +guess um good so um what we're going to + + align:start position:0% +guess um good so um what we're going to + + + align:start position:0% +guess um good so um what we're going to +do is Now launch into our next learning + + align:start position:0% +do is Now launch into our next learning + + + align:start position:0% +do is Now launch into our next learning +objective which is to list the cause + + align:start position:0% +objective which is to list the cause + + + align:start position:0% +objective which is to list the cause +A variation and intermittency of the + + align:start position:0% +A variation and intermittency of the + + + align:start position:0% +A variation and intermittency of the +solar resource and quantify their time + + align:start position:0% +solar resource and quantify their time + + + align:start position:0% +solar resource and quantify their time +constants and magnitudes this is really + + align:start position:0% +constants and magnitudes this is really + + + align:start position:0% +constants and magnitudes this is really +really really really important um the + + align:start position:0% +really really really important um the + + + align:start position:0% +really really really important um the +other stuff is very useful from an + + align:start position:0% +other stuff is very useful from an + + + align:start position:0% +other stuff is very useful from an +engineering point of view from answering + + align:start position:0% +engineering point of view from answering + + + align:start position:0% +engineering point of view from answering +certain questions in your homework um + + align:start position:0% +certain questions in your homework um + + + align:start position:0% +certain questions in your homework um +this right here determines or is is the + + align:start position:0% +this right here determines or is is the + + + align:start position:0% +this right here determines or is is the +singular reason one of the singular + + align:start position:0% +singular reason one of the singular + + + align:start position:0% +singular reason one of the singular +reasons why solar doesn't behave like a + + align:start position:0% +reasons why solar doesn't behave like a + + + align:start position:0% +reasons why solar doesn't behave like a +regular fossil fuel source why solar + + align:start position:0% +regular fossil fuel source why solar + + + align:start position:0% +regular fossil fuel source why solar +does not produce power all the time it + + align:start position:0% +does not produce power all the time it + + + align:start position:0% +does not produce power all the time it +is variable in terms of its power output + + align:start position:0% +is variable in terms of its power output + + + align:start position:0% +is variable in terms of its power output +variability generally refers to the fact + + align:start position:0% +variability generally refers to the fact + + + align:start position:0% +variability generally refers to the fact +that we can predict its coming it's + + align:start position:0% +that we can predict its coming it's + + + align:start position:0% +that we can predict its coming it's +going to vary but at least we can + + align:start position:0% +going to vary but at least we can + + + align:start position:0% +going to vary but at least we can +predict its coming intermittency um + + align:start position:0% +predict its coming intermittency um + + + align:start position:0% +predict its coming intermittency um +while not a strict definition the the + + align:start position:0% +while not a strict definition the the + + + align:start position:0% +while not a strict definition the the +understanding when somebody says + + align:start position:0% +understanding when somebody says + + + align:start position:0% +understanding when somebody says +intermittency or intermittent power + + align:start position:0% +intermittency or intermittent power + + + align:start position:0% +intermittency or intermittent power +source the the impression that it gives + + align:start position:0% +source the the impression that it gives + + + align:start position:0% +source the the impression that it gives +is that it's unpredictable in in terms + + align:start position:0% +is that it's unpredictable in in terms + + + align:start position:0% +is that it's unpredictable in in terms +of its variability and its variation so + + align:start position:0% +of its variability and its variation so + + + align:start position:0% +of its variability and its variation so +we've talked a little bit about the + + align:start position:0% +we've talked a little bit about the + + + align:start position:0% +we've talked a little bit about the +variation so far and about the + + align:start position:0% +variation so far and about the + + + align:start position:0% +variation so far and about the +predictable nature of the sun we've + + align:start position:0% +predictable nature of the sun we've + + + align:start position:0% +predictable nature of the sun we've +talked about how the sunlight the solar + + align:start position:0% +talked about how the sunlight the solar + + + align:start position:0% +talked about how the sunlight the solar +resource varies from Summer to Winter + + align:start position:0% +resource varies from Summer to Winter + + + align:start position:0% +resource varies from Summer to Winter +we've talked about how the uh solar + + align:start position:0% +we've talked about how the uh solar + + + align:start position:0% +we've talked about how the uh solar +resource um uh varies as a function of + + align:start position:0% +resource um uh varies as a function of + + + align:start position:0% +resource um uh varies as a function of +uh latitude right but now um we're going + + align:start position:0% +uh latitude right but now um we're going + + + align:start position:0% +uh latitude right but now um we're going +to talk not only in a little bit more + + align:start position:0% +to talk not only in a little bit more + + + align:start position:0% +to talk not only in a little bit more +depth about that and have a few fun + + align:start position:0% +depth about that and have a few fun + + + align:start position:0% +depth about that and have a few fun +in-class exercises to get us really + + align:start position:0% +in-class exercises to get us really + + + align:start position:0% +in-class exercises to get us really +grasping that Concept in its entirety + + align:start position:0% +grasping that Concept in its entirety + + + align:start position:0% +grasping that Concept in its entirety +but also talk about some sources of + + align:start position:0% +but also talk about some sources of + + + align:start position:0% +but also talk about some sources of +intermittency which um you know if you + + align:start position:0% +intermittency which um you know if you + + + align:start position:0% +intermittency which um you know if you +have a large amount of solar + + align:start position:0% +have a large amount of solar + + + align:start position:0% +have a large amount of solar +contributing to the grid and it is + + align:start position:0% +contributing to the grid and it is + + + align:start position:0% +contributing to the grid and it is +intermittent and you have no way of + + align:start position:0% +intermittent and you have no way of + + + align:start position:0% +intermittent and you have no way of +dealing with that you're going to have + + align:start position:0% +dealing with that you're going to have + + + align:start position:0% +dealing with that you're going to have +fluctuations of energy level on the GD + + align:start position:0% +fluctuations of energy level on the GD + + + align:start position:0% +fluctuations of energy level on the GD +uh or power levels uh here as a function + + align:start position:0% +uh or power levels uh here as a function + + + align:start position:0% +uh or power levels uh here as a function +of time and that's not going to be + + align:start position:0% +of time and that's not going to be + + + align:start position:0% +of time and that's not going to be +good so in terms of the seasonal + + align:start position:0% +good so in terms of the seasonal + + + align:start position:0% +good so in terms of the seasonal +variations in terms of predicting the uh + + align:start position:0% +variations in terms of predicting the uh + + + align:start position:0% +variations in terms of predicting the uh +the amount coming uh from the Sun at a + + align:start position:0% +the amount coming uh from the Sun at a + + + align:start position:0% +the amount coming uh from the Sun at a +given point I told you it looks a little + + align:start position:0% +given point I told you it looks a little + + + align:start position:0% +given point I told you it looks a little +bit like uh a sign or coine wave and + + align:start position:0% +bit like uh a sign or coine wave and + + + align:start position:0% +bit like uh a sign or coine wave and +indeed it does you can calculate those + + align:start position:0% +indeed it does you can calculate those + + + align:start position:0% +indeed it does you can calculate those +values based on this website right here + + align:start position:0% +values based on this website right here + + + align:start position:0% +values based on this website right here +just to show you how Nifty and cool it + + align:start position:0% +just to show you how Nifty and cool it + + + align:start position:0% +just to show you how Nifty and cool it +is our friends at Arizona State + + align:start position:0% +is our friends at Arizona State + + + align:start position:0% +is our friends at Arizona State +University Stuart Bowden and Christiana + + align:start position:0% +University Stuart Bowden and Christiana + + + align:start position:0% +University Stuart Bowden and Christiana +hansburg really put in a lot of time to + + align:start position:0% +hansburg really put in a lot of time to + + + align:start position:0% +hansburg really put in a lot of time to +make this um you can vary the time or + + align:start position:0% +make this um you can vary the time or + + + align:start position:0% +make this um you can vary the time or +the day of year right here for instance + + align:start position:0% +the day of year right here for instance + + + align:start position:0% +the day of year right here for instance +right and you can see how um the solar + + align:start position:0% +right and you can see how um the solar + + + align:start position:0% +right and you can see how um the solar +resource this is the uh direct radiation + + align:start position:0% +resource this is the uh direct radiation + + + align:start position:0% +resource this is the uh direct radiation +kilowatt per meter squar and this is the + + align:start position:0% +kilowatt per meter squar and this is the + + + align:start position:0% +kilowatt per meter squar and this is the +time so if you take the integral of the + + align:start position:0% +time so if you take the integral of the + + + align:start position:0% +time so if you take the integral of the +the curve right here you're going to get + + align:start position:0% +the curve right here you're going to get + + + align:start position:0% +the curve right here you're going to get +what units + + align:start position:0% + + + + align:start position:0% + +of power power time time is energy + + align:start position:0% +of power power time time is energy + + + align:start position:0% +of power power time time is energy +energy per unit area right so you're + + align:start position:0% +energy per unit area right so you're + + + align:start position:0% +energy per unit area right so you're +going to be able to calculate the total + + align:start position:0% +going to be able to calculate the total + + + align:start position:0% +going to be able to calculate the total +amount of energy falling on a given area + + align:start position:0% +amount of energy falling on a given area + + + align:start position:0% +amount of energy falling on a given area +per day let's say right so if we look at + + align:start position:0% +per day let's say right so if we look at + + + align:start position:0% +per day let's say right so if we look at +the size of this little curve in Winter + + align:start position:0% +the size of this little curve in Winter + + + align:start position:0% +the size of this little curve in Winter +uh the total area under this is going to + + align:start position:0% +uh the total area under this is going to + + + align:start position:0% +uh the total area under this is going to +be very small that's because the solar + + align:start position:0% +be very small that's because the solar + + + align:start position:0% +be very small that's because the solar +resource is very small and the sun rises + + align:start position:0% +resource is very small and the sun rises + + + align:start position:0% +resource is very small and the sun rises +late and sets early in Winter and as we + + align:start position:0% +late and sets early in Winter and as we + + + align:start position:0% +late and sets early in Winter and as we +move toward + + align:start position:0% +move toward + + + align:start position:0% +move toward +summer obviously the total amount of the + + align:start position:0% +summer obviously the total amount of the + + + align:start position:0% +summer obviously the total amount of the +solar resource increases uh not only it + + align:start position:0% +solar resource increases uh not only it + + + align:start position:0% +solar resource increases uh not only it +increases because of this that we have + + align:start position:0% +increases because of this that we have + + + align:start position:0% +increases because of this that we have +at solar noon uh we have less of a path + + align:start position:0% +at solar noon uh we have less of a path + + + align:start position:0% +at solar noon uh we have less of a path +through the atmosphere we have more + + align:start position:0% +through the atmosphere we have more + + + align:start position:0% +through the atmosphere we have more +sunlight reaching the Earth we have a + + align:start position:0% +sunlight reaching the Earth we have a + + + align:start position:0% +sunlight reaching the Earth we have a +total uh increase of of of of the um of + + align:start position:0% +total uh increase of of of of the um of + + + align:start position:0% +total uh increase of of of of the um of +the amount reaching the Earth we also + + align:start position:0% +the amount reaching the Earth we also + + + align:start position:0% +the amount reaching the Earth we also +have that cosine Theta term here uh + + align:start position:0% +have that cosine Theta term here uh + + + align:start position:0% +have that cosine Theta term here uh +dictating the um the the I say the + + align:start position:0% +dictating the um the the I say the + + + align:start position:0% +dictating the um the the I say the +cross-section incident uh to that + + align:start position:0% +cross-section incident uh to that + + + align:start position:0% +cross-section incident uh to that +sunlight coming in increasing and so + + align:start position:0% +sunlight coming in increasing and so + + + align:start position:0% +sunlight coming in increasing and so +that's driving this going up and we also + + align:start position:0% +that's driving this going up and we also + + + align:start position:0% +that's driving this going up and we also +have a second fact that the time of the + + align:start position:0% +have a second fact that the time of the + + + align:start position:0% +have a second fact that the time of the +day the total duration of the day + + align:start position:0% +day the total duration of the day + + + align:start position:0% +day the total duration of the day +increases at least in Northern latitudes + + align:start position:0% +increases at least in Northern latitudes + + + align:start position:0% +increases at least in Northern latitudes +and here at around 40 let's say 41 + + align:start position:0% +and here at around 40 let's say 41 + + + align:start position:0% +and here at around 40 let's say 41 +degrees north here in Boston and uh we + + align:start position:0% +degrees north here in Boston and uh we + + + align:start position:0% +degrees north here in Boston and uh we +have uh because of these two effects a + + align:start position:0% +have uh because of these two effects a + + + align:start position:0% +have uh because of these two effects a +much uh larger area underneath uh that + + align:start position:0% +much uh larger area underneath uh that + + + align:start position:0% +much uh larger area underneath uh that +curve and so as we go through summer and + + align:start position:0% +curve and so as we go through summer and + + + align:start position:0% +curve and so as we go through summer and +now finally to September 13th um and + + align:start position:0% +now finally to September 13th um and + + + align:start position:0% +now finally to September 13th um and +back to Winter our solar resource goes + + align:start position:0% +back to Winter our solar resource goes + + + align:start position:0% +back to Winter our solar resource goes +back down again so you can calculate it + + align:start position:0% +back down again so you can calculate it + + + align:start position:0% +back down again so you can calculate it +you can visualize it that's + + align:start position:0% +you can visualize it that's + + + align:start position:0% +you can visualize it that's +cool um and we can plot the total amount + + align:start position:0% +cool um and we can plot the total amount + + + align:start position:0% +cool um and we can plot the total amount +of energy per unit area per day + + align:start position:0% +of energy per unit area per day + + + align:start position:0% +of energy per unit area per day +essentially the integral under that + + align:start position:0% +essentially the integral under that + + + align:start position:0% +essentially the integral under that +curve as a function of location around + + align:start position:0% +curve as a function of location around + + + align:start position:0% +curve as a function of location around +the us around the world um per month + + align:start position:0% +the us around the world um per month + + + align:start position:0% +the us around the world um per month +let's say right so this is January this + + align:start position:0% +let's say right so this is January this + + + align:start position:0% +let's say right so this is January this +is kilowatt hours per meter squar per + + align:start position:0% +is kilowatt hours per meter squar per + + + align:start position:0% +is kilowatt hours per meter squar per +day so it's just taking the integral of + + align:start position:0% +day so it's just taking the integral of + + + align:start position:0% +day so it's just taking the integral of +the + + align:start position:0% +the + + + align:start position:0% +the +curves um measured so it's accounting + + align:start position:0% +curves um measured so it's accounting + + + align:start position:0% +curves um measured so it's accounting +for cloudy days which kind of has a + + align:start position:0% +for cloudy days which kind of has a + + + align:start position:0% +for cloudy days which kind of has a +depressive effect this is an envelope + + align:start position:0% +depressive effect this is an envelope + + + align:start position:0% +depressive effect this is an envelope +function if you will the maximum you + + align:start position:0% +function if you will the maximum you + + + align:start position:0% +function if you will the maximum you +could get and then of course local + + align:start position:0% +could get and then of course local + + + align:start position:0% +could get and then of course local +weather patterns will suppress that + + align:start position:0% +weather patterns will suppress that + + + align:start position:0% +weather patterns will suppress that +drive it down so this is um this is the + + align:start position:0% +drive it down so this is um this is the + + + align:start position:0% +drive it down so this is um this is the +real map of the United States and you + + align:start position:0% +real map of the United States and you + + + align:start position:0% +real map of the United States and you +can see um in sunnier areas that are + + align:start position:0% +can see um in sunnier areas that are + + + align:start position:0% +can see um in sunnier areas that are +less cloudy over here for example in + + align:start position:0% +less cloudy over here for example in + + + align:start position:0% +less cloudy over here for example in +Arizona New Mexico there is a large + + align:start position:0% +Arizona New Mexico there is a large + + + align:start position:0% +Arizona New Mexico there is a large +solar resource even in January Atlanta + + align:start position:0% +solar resource even in January Atlanta + + + align:start position:0% +solar resource even in January Atlanta +which has half of the number of sunny + + align:start position:0% +which has half of the number of sunny + + + align:start position:0% +which has half of the number of sunny +days per year as Phoenix does even if + + align:start position:0% +days per year as Phoenix does even if + + + align:start position:0% +days per year as Phoenix does even if +it's the same latitude is getting about + + align:start position:0% +it's the same latitude is getting about + + + align:start position:0% +it's the same latitude is getting about +half the solar resource they got a short + + align:start position:0% +half the solar resource they got a short + + + align:start position:0% +half the solar resource they got a short +end of the stick again this uh curve + + align:start position:0% +end of the stick again this uh curve + + + align:start position:0% +end of the stick again this uh curve +right here is the envelope function + + align:start position:0% +right here is the envelope function + + + align:start position:0% +right here is the envelope function +right and off of that uh you can you can + + align:start position:0% +right and off of that uh you can you can + + + align:start position:0% +right and off of that uh you can you can +only go down you can only decrease the + + align:start position:0% +only go down you can only decrease the + + + align:start position:0% +only go down you can only decrease the +amount of solar resource actually + + align:start position:0% +amount of solar resource actually + + + align:start position:0% +amount of solar resource actually +arriving at our at our feet here and so + + align:start position:0% +arriving at our at our feet here and so + + + align:start position:0% +arriving at our at our feet here and so +this is in January and this is all in + + align:start position:0% +this is in January and this is all in + + + align:start position:0% +this is in January and this is all in +the same color scale here as we move + + align:start position:0% +the same color scale here as we move + + + align:start position:0% +the same color scale here as we move +through the months so we'll move from + + align:start position:0% +through the months so we'll move from + + + align:start position:0% +through the months so we'll move from +January to February to March April May + + align:start position:0% +January to February to March April May + + + align:start position:0% +January to February to March April May +June July August September October + + align:start position:0% +June July August September October + + + align:start position:0% +June July August September October +November + + align:start position:0% +November + + + align:start position:0% +November +December so you can see across the + + align:start position:0% +December so you can see across the + + + align:start position:0% +December so you can see across the +United States how the resources + + align:start position:0% +United States how the resources + + + align:start position:0% +United States how the resources +distributed geographically the general + + align:start position:0% +distributed geographically the general + + + align:start position:0% +distributed geographically the general +Trend that as you go from south to North + + align:start position:0% +Trend that as you go from south to North + + + align:start position:0% +Trend that as you go from south to North +you have a decreasing solar resource + + align:start position:0% +you have a decreasing solar resource + + + align:start position:0% +you have a decreasing solar resource +holds you can also see the influence of + + align:start position:0% +holds you can also see the influence of + + + align:start position:0% +holds you can also see the influence of +local weather patterns as well for the + + align:start position:0% +local weather patterns as well for the + + + align:start position:0% +local weather patterns as well for the +same + + align:start position:0% +same + + + align:start position:0% +same +latitude so that's pretty nifty and + + align:start position:0% +latitude so that's pretty nifty and + + + align:start position:0% +latitude so that's pretty nifty and +another Nifty fact if you look at the + + align:start position:0% +another Nifty fact if you look at the + + + align:start position:0% +another Nifty fact if you look at the +year average value annual this is the + + align:start position:0% +year average value annual this is the + + + align:start position:0% +year average value annual this is the +annual average value here in Boston + + align:start position:0% +annual average value here in Boston + + + align:start position:0% +annual average value here in Boston +we're averaging around 4.5 kilowatt + + align:start position:0% +we're averaging around 4.5 kilowatt + + + align:start position:0% +we're averaging around 4.5 kilowatt +hours per meter Square per day uh + + align:start position:0% +hours per meter Square per day uh + + + align:start position:0% +hours per meter Square per day uh +Phoenix Arizona can be upwards of of six + + align:start position:0% +Phoenix Arizona can be upwards of of six + + + align:start position:0% +Phoenix Arizona can be upwards of of six +somewhere in in the outskirts it's not + + align:start position:0% +somewhere in in the outskirts it's not + + + align:start position:0% +somewhere in in the outskirts it's not +that + + align:start position:0% +that + + + align:start position:0% +that +bad it's only it's only a few tens of + + align:start position:0% +bad it's only it's only a few tens of + + + align:start position:0% +bad it's only it's only a few tens of +percent it's it's not that bad I tell + + align:start position:0% +percent it's it's not that bad I tell + + + align:start position:0% +percent it's it's not that bad I tell +myself I don't I don't believe it I + + align:start position:0% +myself I don't I don't believe it I + + + align:start position:0% +myself I don't I don't believe it I +don't believe it myself either but I try + + align:start position:0% +don't believe it myself either but I try + + + align:start position:0% +don't believe it myself either but I try +to convince myself of that during winter + + align:start position:0% +to convince myself of that during winter + + + align:start position:0% +to convince myself of that during winter +all right let me show you the seasonal + + align:start position:0% +all right let me show you the seasonal + + + align:start position:0% +all right let me show you the seasonal +and urinal variation + + align:start position:0% +and urinal variation + + + align:start position:0% +and urinal variation +from We're increasing the level of + + align:start position:0% +from We're increasing the level of + + + align:start position:0% +from We're increasing the level of +sophistication as we go along right + + align:start position:0% +sophistication as we go along right + + + align:start position:0% +sophistication as we go along right +we've assumed you've done your readings + + align:start position:0% +we've assumed you've done your readings + + + align:start position:0% +we've assumed you've done your readings +we've started with some simple examples + + align:start position:0% +we've started with some simple examples + + + align:start position:0% +we've started with some simple examples +and now we're really taking it one step + + align:start position:0% +and now we're really taking it one step + + + align:start position:0% +and now we're really taking it one step +further which is to introduce the full + + align:start position:0% +further which is to introduce the full + + + align:start position:0% +further which is to introduce the full +3d model and I'm going to do that by use + + align:start position:0% +3d model and I'm going to do that by use + + + align:start position:0% +3d model and I'm going to do that by use +of this really cool uh app that's + + align:start position:0% +of this really cool uh app that's + + + align:start position:0% +of this really cool uh app that's +available + + align:start position:0% +available + + + align:start position:0% +available +here right here this is you standing on + + align:start position:0% +here right here this is you standing on + + + align:start position:0% +here right here this is you standing on +the earth and you can drag and pull this + + align:start position:0% +the earth and you can drag and pull this + + + align:start position:0% +the earth and you can drag and pull this +around you can see this north south east + + align:start position:0% +around you can see this north south east + + + align:start position:0% +around you can see this north south east +and west so I'm going to pull it up a + + align:start position:0% +and west so I'm going to pull it up a + + + align:start position:0% +and west so I'm going to pull it up a +little bit just to get give us a little + + align:start position:0% +little bit just to get give us a little + + + align:start position:0% +little bit just to get give us a little +bit of perspective still South is facing + + align:start position:0% +bit of perspective still South is facing + + + align:start position:0% +bit of perspective still South is facing +toward us North is away the sun will + + align:start position:0% +toward us North is away the sun will + + + align:start position:0% +toward us North is away the sun will +rise in the east and set in the west now + + align:start position:0% +rise in the east and set in the west now + + + align:start position:0% +rise in the east and set in the west now +if I let's say I pull the the date back + + align:start position:0% +if I let's say I pull the the date back + + + align:start position:0% +if I let's say I pull the the date back +to uh September so this little tool is + + align:start position:0% +to uh September so this little tool is + + + align:start position:0% +to uh September so this little tool is +so cool because it recognizes your IP + + align:start position:0% +so cool because it recognizes your IP + + + align:start position:0% +so cool because it recognizes your IP +address and situates you at the proper + + align:start position:0% +address and situates you at the proper + + + align:start position:0% +address and situates you at the proper +latitude so we don't have to touch that + + align:start position:0% +latitude so we don't have to touch that + + + align:start position:0% +latitude so we don't have to touch that +at all it's it's approximately right + + align:start position:0% +at all it's it's approximately right + + + align:start position:0% +at all it's it's approximately right +we're at 40 about 41 Dees um we're right + + align:start position:0% +we're at 40 about 41 Dees um we're right + + + align:start position:0% +we're at 40 about 41 Dees um we're right +here in September and in terms of time + + align:start position:0% +here in September and in terms of time + + + align:start position:0% +here in September and in terms of time +of day we can pretty much just cycle + + align:start position:0% +of day we can pretty much just cycle + + + align:start position:0% +of day we can pretty much just cycle +through the time of day if we like um we + + align:start position:0% +through the time of day if we like um we + + + align:start position:0% +through the time of day if we like um we +could uh for example uh start animation + + align:start position:0% +could uh for example uh start animation + + + align:start position:0% +could uh for example uh start animation +let's see this is uh going very fast + + align:start position:0% +let's see this is uh going very fast + + + align:start position:0% +let's see this is uh going very fast +right now I'm going to slow it down so + + align:start position:0% +right now I'm going to slow it down so + + + align:start position:0% +right now I'm going to slow it down so +you can see the time of day moving uh + + align:start position:0% +you can see the time of day moving uh + + + align:start position:0% +you can see the time of day moving uh +right over here and you can see this the + + align:start position:0% +right over here and you can see this the + + + align:start position:0% +right over here and you can see this the +relative to our vintage point on the + + align:start position:0% +relative to our vintage point on the + + + align:start position:0% +relative to our vintage point on the +surface of the Earth this little yellow + + align:start position:0% +surface of the Earth this little yellow + + + align:start position:0% +surface of the Earth this little yellow +dot here and this yellow line is tracing + + align:start position:0% +dot here and this yellow line is tracing + + + align:start position:0% +dot here and this yellow line is tracing +through the path of the sun and the sky + + align:start position:0% +through the path of the sun and the sky + + + align:start position:0% +through the path of the sun and the sky +from our perspective and so as we go + + align:start position:0% +from our perspective and so as we go + + + align:start position:0% +from our perspective and so as we go +through the seasons I'm going to speed + + align:start position:0% +through the seasons I'm going to speed + + + align:start position:0% +through the seasons I'm going to speed +it up just a little bit so that we pay + + align:start position:0% +it up just a little bit so that we pay + + + align:start position:0% +it up just a little bit so that we pay +more attention to the the position of + + align:start position:0% +more attention to the the position of + + + align:start position:0% +more attention to the the position of +this yellow line and less less attention + + align:start position:0% +this yellow line and less less attention + + + align:start position:0% +this yellow line and less less attention +to the deal variations we're paying more + + align:start position:0% +to the deal variations we're paying more + + + align:start position:0% +to the deal variations we're paying more +attention to the seasonal variations I'm + + align:start position:0% +attention to the seasonal variations I'm + + + align:start position:0% +attention to the seasonal variations I'm +going to vary the seasons by force here + + align:start position:0% +going to vary the seasons by force here + + + align:start position:0% +going to vary the seasons by force here +I'm going to go back to July or June if + + align:start position:0% +I'm going to go back to July or June if + + + align:start position:0% +I'm going to go back to July or June if +I may here we + + align:start position:0% +I may here we + + + align:start position:0% +I may here we +go yeah so there's there's a number of + + align:start position:0% +go yeah so there's there's a number of + + + align:start position:0% +go yeah so there's there's a number of +other uh lines right here and they're + + align:start position:0% +other uh lines right here and they're + + + align:start position:0% +other uh lines right here and they're +all explained very carefully um there's + + align:start position:0% +all explained very carefully um there's + + + align:start position:0% +all explained very carefully um there's +uh the um the hour of Ascension which + + align:start position:0% +uh the um the hour of Ascension which + + + align:start position:0% +uh the um the hour of Ascension which +would be um + + align:start position:0% + + + + align:start position:0% + +Prime hour Circle yeah so I I believe um + + align:start position:0% +Prime hour Circle yeah so I I believe um + + + align:start position:0% +Prime hour Circle yeah so I I believe um +I'd have to go back and double check all + + align:start position:0% +I'd have to go back and double check all + + + align:start position:0% +I'd have to go back and double check all +of this but I believe they relate to the + + align:start position:0% +of this but I believe they relate to the + + + align:start position:0% +of this but I believe they relate to the +um what would be the sunrise and sunset + + align:start position:0% +um what would be the sunrise and sunset + + + align:start position:0% +um what would be the sunrise and sunset +at that given day let's see if we're our + + align:start position:0% +at that given day let's see if we're our + + + align:start position:0% +at that given day let's see if we're our +hypothesis is correct no it is not um + + align:start position:0% +hypothesis is correct no it is not um + + + align:start position:0% +hypothesis is correct no it is not um +that would have to be uh since it's + + align:start position:0% +that would have to be uh since it's + + + align:start position:0% +that would have to be uh since it's +varying in a systematic way from January + + align:start position:0% +varying in a systematic way from January + + + align:start position:0% +varying in a systematic way from January +uh through uh through the summer and + + align:start position:0% +uh through uh through the summer and + + + align:start position:0% +uh through uh through the summer and +then back to the winter I'm I'm + + align:start position:0% +then back to the winter I'm I'm + + + align:start position:0% +then back to the winter I'm I'm +imagining this has something to do with + + align:start position:0% +imagining this has something to do with + + + align:start position:0% +imagining this has something to do with +the direction of of the sun uh relative + + align:start position:0% +the direction of of the sun uh relative + + + align:start position:0% +the direction of of the sun uh relative +to the Earth right as it traces that + + align:start position:0% +to the Earth right as it traces that + + + align:start position:0% +to the Earth right as it traces that +ellipse through the sky + + align:start position:0% +ellipse through the sky + + + align:start position:0% +ellipse through the sky +so let's pay attention to that yellow + + align:start position:0% +so let's pay attention to that yellow + + + align:start position:0% +so let's pay attention to that yellow +line for a minute that's the one I want + + align:start position:0% +line for a minute that's the one I want + + + align:start position:0% +line for a minute that's the one I want +to attract everybody's attention to now + + align:start position:0% +to attract everybody's attention to now + + + align:start position:0% +to attract everybody's attention to now +we're in June so in the height of Summer + + align:start position:0% +we're in June so in the height of Summer + + + align:start position:0% +we're in June so in the height of Summer +and relative to this Observer right here + + align:start position:0% +and relative to this Observer right here + + + align:start position:0% +and relative to this Observer right here +the sun is further up in the sky right + + align:start position:0% +the sun is further up in the sky right + + + align:start position:0% +the sun is further up in the sky right +just like we traced out right there and + + align:start position:0% +just like we traced out right there and + + + align:start position:0% +just like we traced out right there and +now as we go to Winter that line drops + + align:start position:0% +now as we go to Winter that line drops + + + align:start position:0% +now as we go to Winter that line drops +closer to the Horizon so a couple of + + align:start position:0% +closer to the Horizon so a couple of + + + align:start position:0% +closer to the Horizon so a couple of +things happen if we look like this for + + align:start position:0% +things happen if we look like this for + + + align:start position:0% +things happen if we look like this for +instance now we're looking straight down + + align:start position:0% +instance now we're looking straight down + + + align:start position:0% +instance now we're looking straight down +on the observer in winter time the Sun + + align:start position:0% +on the observer in winter time the Sun + + + align:start position:0% +on the observer in winter time the Sun +will rise in the Southeast right and + + align:start position:0% +will rise in the Southeast right and + + + align:start position:0% +will rise in the Southeast right and +it'll trace this bark through the sky + + align:start position:0% +it'll trace this bark through the sky + + + align:start position:0% +it'll trace this bark through the sky +and set in the southwest over here in + + align:start position:0% +and set in the southwest over here in + + + align:start position:0% +and set in the southwest over here in +the + + align:start position:0% +the + + + align:start position:0% +the +summertime the sun will + + align:start position:0% +summertime the sun will + + + align:start position:0% +summertime the sun will +rise almost in the Northeast north of + + align:start position:0% +rise almost in the Northeast north of + + + align:start position:0% +rise almost in the Northeast north of +nor north of East right north of uh just + + align:start position:0% +nor north of East right north of uh just + + + align:start position:0% +nor north of East right north of uh just +Slightly North of East and that's why if + + align:start position:0% +Slightly North of East and that's why if + + + align:start position:0% +Slightly North of East and that's why if +you have a North facing window and you + + align:start position:0% +you have a North facing window and you + + + align:start position:0% +you have a North facing window and you +put your little plant on the window sill + + align:start position:0% +put your little plant on the window sill + + + align:start position:0% +put your little plant on the window sill +it'll get a little bit of direct + + align:start position:0% +it'll get a little bit of direct + + + align:start position:0% +it'll get a little bit of direct +sunlight early in the morning and late + + align:start position:0% +sunlight early in the morning and late + + + align:start position:0% +sunlight early in the morning and late +at night it's when the sun is tracing + + align:start position:0% +at night it's when the sun is tracing + + + align:start position:0% +at night it's when the sun is tracing +this part or that part through its Trace + + align:start position:0% +this part or that part through its Trace + + + align:start position:0% +this part or that part through its Trace +in the sky so it's worth sitting down + + align:start position:0% +in the sky so it's worth sitting down + + + align:start position:0% +in the sky so it's worth sitting down +with one of these plots toying around + + align:start position:0% +with one of these plots toying around + + + align:start position:0% +with one of these plots toying around +with it getting accustomed to it and + + align:start position:0% +with it getting accustomed to it and + + + align:start position:0% +with it getting accustomed to it and +understanding really how the Sun traces + + align:start position:0% +understanding really how the Sun traces + + + align:start position:0% +understanding really how the Sun traces +his Arc through throughout the sky + + align:start position:0% +his Arc through throughout the sky + + + align:start position:0% +his Arc through throughout the sky +relative to our position right here on + + align:start position:0% +relative to our position right here on + + + align:start position:0% +relative to our position right here on +the earth if we shift this further up + + align:start position:0% +the earth if we shift this further up + + + align:start position:0% +the earth if we shift this further up +north thing really interesting things + + align:start position:0% +north thing really interesting things + + + align:start position:0% +north thing really interesting things +begin to happen so for example my wife + + align:start position:0% +begin to happen so for example my wife + + + align:start position:0% +begin to happen so for example my wife +is from Sweden if we go to her hometown + + align:start position:0% +is from Sweden if we go to her hometown + + + align:start position:0% +is from Sweden if we go to her hometown +right here in the middle of summertime + + align:start position:0% +right here in the middle of summertime + + + align:start position:0% +right here in the middle of summertime +right at the solstice you can see the + + align:start position:0% +right at the solstice you can see the + + + align:start position:0% +right at the solstice you can see the +sun traces this awesome route from north + + align:start position:0% +sun traces this awesome route from north + + + align:start position:0% +sun traces this awesome route from north +to North uh barely leaving the Horizon + + align:start position:0% +to North uh barely leaving the Horizon + + + align:start position:0% +to North uh barely leaving the Horizon +if we look at um again from the + + align:start position:0% +if we look at um again from the + + + align:start position:0% +if we look at um again from the +perspective of the little creature here + + align:start position:0% +perspective of the little creature here + + + align:start position:0% +perspective of the little creature here +that um that yellow Arc is really close + + align:start position:0% +that um that yellow Arc is really close + + + align:start position:0% +that um that yellow Arc is really close +to the Horizon maybe it goes up about + + align:start position:0% +to the Horizon maybe it goes up about + + + align:start position:0% +to the Horizon maybe it goes up about +that high but it continues going all the + + align:start position:0% +that high but it continues going all the + + + align:start position:0% +that high but it continues going all the +way to the north and if you keep going + + align:start position:0% +way to the north and if you keep going + + + align:start position:0% +way to the north and if you keep going +north it will never set during the + + align:start position:0% +north it will never set during the + + + align:start position:0% +north it will never set during the +middle of summer it'll just be light all + + align:start position:0% +middle of summer it'll just be light all + + + align:start position:0% +middle of summer it'll just be light all +the time and you can see here it just + + align:start position:0% +the time and you can see here it just + + + align:start position:0% +the time and you can see here it just +traces that orbit right around there + + align:start position:0% +traces that orbit right around there + + + align:start position:0% +traces that orbit right around there +it's all trig folks we can do it we can + + align:start position:0% +it's all trig folks we can do it we can + + + align:start position:0% +it's all trig folks we can do it we can +sit down and we can work through the + + align:start position:0% +sit down and we can work through the + + + align:start position:0% +sit down and we can work through the +equations by hand I did that once it + + align:start position:0% +equations by hand I did that once it + + + align:start position:0% +equations by hand I did that once it +took me a long time I didn't learn that + + align:start position:0% +took me a long time I didn't learn that + + + align:start position:0% +took me a long time I didn't learn that +much um I would uh would instead advise + + align:start position:0% +much um I would uh would instead advise + + + align:start position:0% +much um I would uh would instead advise +you to go to one of these simulations + + align:start position:0% +you to go to one of these simulations + + + align:start position:0% +you to go to one of these simulations +right here but to understand all the + + align:start position:0% +right here but to understand all the + + + align:start position:0% +right here but to understand all the +inputs into it all the different uh + + align:start position:0% +inputs into it all the different uh + + + align:start position:0% +inputs into it all the different uh +components right the fact that the Sun + + align:start position:0% +components right the fact that the Sun + + + align:start position:0% +components right the fact that the Sun +the Earth is moving around the Sun as a + + align:start position:0% +the Earth is moving around the Sun as a + + + align:start position:0% +the Earth is moving around the Sun as a +declination angle uh seasonal variations + + align:start position:0% +declination angle uh seasonal variations + + + align:start position:0% +declination angle uh seasonal variations +and so forth very useful tool you have + + align:start position:0% +and so forth very useful tool you have + + + align:start position:0% +and so forth very useful tool you have +the website link right here and um and + + align:start position:0% +the website link right here and um and + + + align:start position:0% +the website link right here and um and +yeah so from this tool actually one last + + align:start position:0% +yeah so from this tool actually one last + + + align:start position:0% +yeah so from this tool actually one last +tiny tiny thing from this tool right + + align:start position:0% +tiny tiny thing from this tool right + + + align:start position:0% +tiny tiny thing from this tool right +here we can understand why okay this + + align:start position:0% +here we can understand why okay this + + + align:start position:0% +here we can understand why okay this +isn't this is real stretch and and and + + align:start position:0% +isn't this is real stretch and and and + + + align:start position:0% +isn't this is real stretch and and and +forgive me uh uh social scientists in + + align:start position:0% +forgive me uh uh social scientists in + + + align:start position:0% +forgive me uh uh social scientists in +the room for doing this but um I have to + + align:start position:0% +the room for doing this but um I have to + + + align:start position:0% +the room for doing this but um I have to +project a little bit of science onto + + align:start position:0% +project a little bit of science onto + + + align:start position:0% +project a little bit of science onto +human behavior um how far west is Madrid + + align:start position:0% +human behavior um how far west is Madrid + + + align:start position:0% +human behavior um how far west is Madrid +from uh GMT Madrid Spain it's 3 degrees + + align:start position:0% +from uh GMT Madrid Spain it's 3 degrees + + + align:start position:0% +from uh GMT Madrid Spain it's 3 degrees +west of the of the great Meridian right + + align:start position:0% +west of the of the great Meridian right + + + align:start position:0% +west of the of the great Meridian right +so the line that divides the East and + + align:start position:0% +so the line that divides the East and + + + align:start position:0% +so the line that divides the East and +the west hemispheres it's 3 degrees west + + align:start position:0% +the west hemispheres it's 3 degrees west + + + align:start position:0% +the west hemispheres it's 3 degrees west +but it is one time zone earlier than + + align:start position:0% +but it is one time zone earlier than + + + align:start position:0% +but it is one time zone earlier than +London right so it's in the same time + + align:start position:0% +London right so it's in the same time + + + align:start position:0% +London right so it's in the same time +zone as Germany and all the other cities + + align:start position:0% +zone as Germany and all the other cities + + + align:start position:0% +zone as Germany and all the other cities +that are uh uh east of of of of London + + align:start position:0% +that are uh uh east of of of of London + + + align:start position:0% +that are uh uh east of of of of London +um and this is just for convenience + + align:start position:0% +um and this is just for convenience + + + align:start position:0% +um and this is just for convenience +factor uh if you're traveling from one + + align:start position:0% +factor uh if you're traveling from one + + + align:start position:0% +factor uh if you're traveling from one +Continental European country to the + + align:start position:0% +Continental European country to the + + + align:start position:0% +Continental European country to the +other it just makes sense to have + + align:start position:0% +other it just makes sense to have + + + align:start position:0% +other it just makes sense to have +everything be on the same time zone you + + align:start position:0% +everything be on the same time zone you + + + align:start position:0% +everything be on the same time zone you +get to work at the same time sort of + + align:start position:0% +get to work at the same time sort of + + + align:start position:0% +get to work at the same time sort of +pick up the phone call somebody uh + + align:start position:0% +pick up the phone call somebody uh + + + align:start position:0% +pick up the phone call somebody uh +you're you're doing business now + + align:start position:0% +you're you're doing business now + + + align:start position:0% +you're you're doing business now +relative to uh everybody else in Europe + + align:start position:0% +relative to uh everybody else in Europe + + + align:start position:0% +relative to uh everybody else in Europe +though is the sun setting later or + + align:start position:0% +though is the sun setting later or + + + align:start position:0% +though is the sun setting later or +earlier if you're that far west in your + + align:start position:0% +earlier if you're that far west in your + + + align:start position:0% +earlier if you're that far west in your +time zone later right so the Sun is + + align:start position:0% +time zone later right so the Sun is + + + align:start position:0% +time zone later right so the Sun is +setting later if you're there so if + + align:start position:0% +setting later if you're there so if + + + align:start position:0% +setting later if you're there so if +you're eating according to the Sun not + + align:start position:0% +you're eating according to the Sun not + + + align:start position:0% +you're eating according to the Sun not +according to what your watch is saying + + align:start position:0% +according to what your watch is saying + + + align:start position:0% +according to what your watch is saying +but if you're if you're choosing to eat + + align:start position:0% +but if you're if you're choosing to eat + + + align:start position:0% +but if you're if you're choosing to eat +dinner when the Sun is setting when will + + align:start position:0% +dinner when the Sun is setting when will + + + align:start position:0% +dinner when the Sun is setting when will +your watch say oh my goodness it's + + align:start position:0% +your watch say oh my goodness it's + + + align:start position:0% +your watch say oh my goodness it's +really late when you're in Berlin or + + align:start position:0% +really late when you're in Berlin or + + + align:start position:0% +really late when you're in Berlin or +when you're in Madrid when you're in + + align:start position:0% +when you're in Madrid when you're in + + + align:start position:0% +when you're in Madrid when you're in +Madrid right so again I'm not saying + + align:start position:0% +Madrid right so again I'm not saying + + + align:start position:0% +Madrid right so again I'm not saying +that this is the sole reason for uh + + align:start position:0% +that this is the sole reason for uh + + + align:start position:0% +that this is the sole reason for uh +social behavior being a little different + + align:start position:0% +social behavior being a little different + + + align:start position:0% +social behavior being a little different +on the Ean peninsula + + align:start position:0% +on the Ean peninsula + + + align:start position:0% +on the Ean peninsula +since Portugal also eats very late and + + align:start position:0% +since Portugal also eats very late and + + + align:start position:0% +since Portugal also eats very late and +they're in the same time zone as London + + align:start position:0% +they're in the same time zone as London + + + align:start position:0% +they're in the same time zone as London +but it it could be a contributing factor + + align:start position:0% +but it it could be a contributing factor + + + align:start position:0% +but it it could be a contributing factor +right the sun is still up in the sky + + align:start position:0% +right the sun is still up in the sky + + + align:start position:0% +right the sun is still up in the sky +when it's 5:00 p.m. in in Winter let's + + align:start position:0% +when it's 5:00 p.m. in in Winter let's + + + align:start position:0% +when it's 5:00 p.m. in in Winter let's +say and where in Germany it's set a long + + align:start position:0% +say and where in Germany it's set a long + + + align:start position:0% +say and where in Germany it's set a long +time ago um so these are are just little + + align:start position:0% +time ago um so these are are just little + + + align:start position:0% +time ago um so these are are just little +things to keep in mind an easy way to + + align:start position:0% +things to keep in mind an easy way to + + + align:start position:0% +things to keep in mind an easy way to +calculate that an easy way to calculate + + align:start position:0% +calculate that an easy way to calculate + + + align:start position:0% +calculate that an easy way to calculate +that when is the solar noon you look at + + align:start position:0% +that when is the solar noon you look at + + + align:start position:0% +that when is the solar noon you look at +the Earth more or less like we're + + align:start position:0% +the Earth more or less like we're + + + align:start position:0% +the Earth more or less like we're +looking at this right now we have 360° + + align:start position:0% +looking at this right now we have 360° + + + align:start position:0% +looking at this right now we have 360° +we divide that into into 24 time zones + + align:start position:0% +we divide that into into 24 time zones + + + align:start position:0% +we divide that into into 24 time zones +and then we say okay about 15 Dees each + + align:start position:0% +and then we say okay about 15 Dees each + + + align:start position:0% +and then we say okay about 15 Dees each +right um and then we can begin counting + + align:start position:0% +right um and then we can begin counting + + + align:start position:0% +right um and then we can begin counting +from there if at in Boston we're 41° + + align:start position:0% +from there if at in Boston we're 41° + + + align:start position:0% +from there if at in Boston we're 41° +North but we're 71° West right we can + + align:start position:0% +North but we're 71° West right we can + + + align:start position:0% +North but we're 71° West right we can +say okay we should be for GMT minus 5 we + + align:start position:0% +say okay we should be for GMT minus 5 we + + + align:start position:0% +say okay we should be for GMT minus 5 we +should be at around 75 degrees and so + + align:start position:0% +should be at around 75 degrees and so + + + align:start position:0% +should be at around 75 degrees and so +we're a little earlier so we do things a + + align:start position:0% +we're a little earlier so we do things a + + + align:start position:0% +we're a little earlier so we do things a +little earlier around here than what the + + align:start position:0% +little earlier around here than what the + + + align:start position:0% +little earlier around here than what the +solar noon should be telling us to do + + align:start position:0% +solar noon should be telling us to do + + + align:start position:0% +solar noon should be telling us to do +things wake up a little earlier go to + + align:start position:0% +things wake up a little earlier go to + + + align:start position:0% +things wake up a little earlier go to +bed a little earlier and that's why + + align:start position:0% +bed a little earlier and that's why + + + align:start position:0% +bed a little earlier and that's why +students like you're like dang there's + + align:start position:0% +students like you're like dang there's + + + align:start position:0% +students like you're like dang there's +no night life around here not saying + + align:start position:0% +no night life around here not saying + + + align:start position:0% +no night life around here not saying +that's the only reason but it could be a + + align:start position:0% +that's the only reason but it could be a + + + align:start position:0% +that's the only reason but it could be a +contributing factor um whereas the + + align:start position:0% +contributing factor um whereas the + + + align:start position:0% +contributing factor um whereas the +opposite happen happens um when you're + + align:start position:0% +opposite happen happens um when you're + + + align:start position:0% +opposite happen happens um when you're +far west in your time zone okay so again + + align:start position:0% +far west in your time zone okay so again + + + align:start position:0% +far west in your time zone okay so again +just trying to wrap our heads around the + + align:start position:0% +just trying to wrap our heads around the + + + align:start position:0% +just trying to wrap our heads around the +solar resource and around uh the world + + align:start position:0% +solar resource and around uh the world + + + align:start position:0% +solar resource and around uh the world +around us so that we can answer that + + align:start position:0% +around us so that we can answer that + + + align:start position:0% +around us so that we can answer that +little child in the shopping mall when + + align:start position:0% +little child in the shopping mall when + + + align:start position:0% +little child in the shopping mall when +they come with questions what are + + align:start position:0% + + + + align:start position:0% + +these solar trash compactors right + + align:start position:0% +these solar trash compactors right + + + align:start position:0% +these solar trash compactors right +student at the student center anaria is + + align:start position:0% +student at the student center anaria is + + + align:start position:0% +student at the student center anaria is +right over there Dunkin' Donuts is there + + align:start position:0% +right over there Dunkin' Donuts is there + + + align:start position:0% +right over there Dunkin' Donuts is there +right so these are solar panels mounted + + align:start position:0% +right so these are solar panels mounted + + + align:start position:0% +right so these are solar panels mounted +on the tops of those um and what the + + align:start position:0% +on the tops of those um and what the + + + align:start position:0% +on the tops of those um and what the +solar is doing is charging a battery + + align:start position:0% +solar is doing is charging a battery + + + align:start position:0% +solar is doing is charging a battery +inside once the trash reaches a critical + + align:start position:0% +inside once the trash reaches a critical + + + align:start position:0% +inside once the trash reaches a critical +lever a sensor is triggered it it stops + + align:start position:0% +lever a sensor is triggered it it stops + + + align:start position:0% +lever a sensor is triggered it it stops +you from opening this bin and it + + align:start position:0% +you from opening this bin and it + + + align:start position:0% +you from opening this bin and it +compacts the trash right and then + + align:start position:0% +compacts the trash right and then + + + align:start position:0% +compacts the trash right and then +releases allows you to open and put more + + align:start position:0% +releases allows you to open and put more + + + align:start position:0% +releases allows you to open and put more +stuff in and what it does is it + + align:start position:0% +stuff in and what it does is it + + + align:start position:0% +stuff in and what it does is it +minimizes the number of times between + + align:start position:0% +minimizes the number of times between + + + align:start position:0% +minimizes the number of times between +trash pickups if labor is a large + + align:start position:0% +trash pickups if labor is a large + + + align:start position:0% +trash pickups if labor is a large +portion of the cost of tra of trash uh + + align:start position:0% +portion of the cost of tra of trash uh + + + align:start position:0% +portion of the cost of tra of trash uh +uh uh management of of waste of Refuge + + align:start position:0% +uh uh management of of waste of Refuge + + + align:start position:0% +uh uh management of of waste of Refuge +management then uh it eliminate some of + + align:start position:0% +management then uh it eliminate some of + + + align:start position:0% +management then uh it eliminate some of +the labor transferring it instead to the + + align:start position:0% +the labor transferring it instead to the + + + align:start position:0% +the labor transferring it instead to the +technology and so installing these at + + align:start position:0% +technology and so installing these at + + + align:start position:0% +technology and so installing these at +the Student Center + + align:start position:0% +the Student Center + + + align:start position:0% +the Student Center +um I had a little bit of a pet peeve + + align:start position:0% +um I had a little bit of a pet peeve + + + align:start position:0% +um I had a little bit of a pet peeve +um so + + align:start position:0% +um so + + + align:start position:0% +um so +um uh you have the the the angle of the + + align:start position:0% +um uh you have the the the angle of the + + + align:start position:0% +um uh you have the the the angle of the +sun right here which we just walked + + align:start position:0% +sun right here which we just walked + + + align:start position:0% +sun right here which we just walked +through 18 degrees in summer and um it + + align:start position:0% +through 18 degrees in summer and um it + + + align:start position:0% +through 18 degrees in summer and um it +it it just so happened to work out that + + align:start position:0% +it it just so happened to work out that + + + align:start position:0% +it it just so happened to work out that +uh and these numbers were approximate + + align:start position:0% +uh and these numbers were approximate + + + align:start position:0% +uh and these numbers were approximate +this was me going with my kind of + + align:start position:0% +this was me going with my kind of + + + align:start position:0% +this was me going with my kind of +engineering sense that's about 45 + + align:start position:0% +engineering sense that's about 45 + + + align:start position:0% +engineering sense that's about 45 +degrees count the number of Paces equ + + align:start position:0% +degrees count the number of Paces equ + + + align:start position:0% +degrees count the number of Paces equ +equ equilateral triangle estimate the + + align:start position:0% +equ equilateral triangle estimate the + + + align:start position:0% +equ equilateral triangle estimate the +height of there um but in the middle of + + align:start position:0% +height of there um but in the middle of + + + align:start position:0% +height of there um but in the middle of +summertime when you are at the solstice + + align:start position:0% +summertime when you are at the solstice + + + align:start position:0% +summertime when you are at the solstice +there is no direct sunlight hitting this + + align:start position:0% +there is no direct sunlight hitting this + + + align:start position:0% +there is no direct sunlight hitting this +trash can because of that overhang way + + align:start position:0% +trash can because of that overhang way + + + align:start position:0% +trash can because of that overhang way +up there that's not a problem for this + + align:start position:0% +up there that's not a problem for this + + + align:start position:0% +up there that's not a problem for this +particular trash collector since those + + align:start position:0% +particular trash collector since those + + + align:start position:0% +particular trash collector since those +panels are way oversized for the amount + + align:start position:0% +panels are way oversized for the amount + + + align:start position:0% +panels are way oversized for the amount +of energy that the trash collector + + align:start position:0% +of energy that the trash collector + + + align:start position:0% +of energy that the trash collector +actually needs um and there is a fair + + align:start position:0% +actually needs um and there is a fair + + + align:start position:0% +actually needs um and there is a fair +amount of what we call diffuse sunlight + + align:start position:0% +amount of what we call diffuse sunlight + + + align:start position:0% +amount of what we call diffuse sunlight +meaning sunlight being scattered off of + + align:start position:0% +meaning sunlight being scattered off of + + + align:start position:0% +meaning sunlight being scattered off of +other things that's why this portion of + + align:start position:0% +other things that's why this portion of + + + align:start position:0% +other things that's why this portion of +the image looks white it wouldn't look + + align:start position:0% +the image looks white it wouldn't look + + + align:start position:0% +the image looks white it wouldn't look +white if there was no diffuse scatter it + + align:start position:0% +white if there was no diffuse scatter it + + + align:start position:0% +white if there was no diffuse scatter it +looked black pitch black if there was no + + align:start position:0% +looked black pitch black if there was no + + + align:start position:0% +looked black pitch black if there was no +nothing to scatter the light off like in + + align:start position:0% +nothing to scatter the light off like in + + + align:start position:0% +nothing to scatter the light off like in +outer space there's nothing to scatter + + align:start position:0% +outer space there's nothing to scatter + + + align:start position:0% +outer space there's nothing to scatter +that's why looks like a black KN um but + + align:start position:0% +that's why looks like a black KN um but + + + align:start position:0% +that's why looks like a black KN um but +instead there's a large amount of + + align:start position:0% +instead there's a large amount of + + + align:start position:0% +instead there's a large amount of +diffuse light there is still some + + align:start position:0% +diffuse light there is still some + + + align:start position:0% +diffuse light there is still some +sunlight reaching it and since the + + align:start position:0% +sunlight reaching it and since the + + + align:start position:0% +sunlight reaching it and since the +panels are way oversized and and and the + + align:start position:0% +panels are way oversized and and and the + + + align:start position:0% +panels are way oversized and and and the +system is over engineered um it still + + align:start position:0% +system is over engineered um it still + + + align:start position:0% +system is over engineered um it still +manages to acquire enough energy to comp + + align:start position:0% +manages to acquire enough energy to comp + + + align:start position:0% +manages to acquire enough energy to comp +back the trash and it doesn't have a + + align:start position:0% +back the trash and it doesn't have a + + + align:start position:0% +back the trash and it doesn't have a +catastrophic stop but it was an example + + align:start position:0% +catastrophic stop but it was an example + + + align:start position:0% +catastrophic stop but it was an example +of somebody not really thinking much + + align:start position:0% +of somebody not really thinking much + + + align:start position:0% +of somebody not really thinking much +about the direction or the the uh angle + + align:start position:0% +about the direction or the the uh angle + + + align:start position:0% +about the direction or the the uh angle +of the Sun in the sky they probably + + align:start position:0% +of the Sun in the sky they probably + + + align:start position:0% +of the Sun in the sky they probably +installed it sometime around March right + + align:start position:0% +installed it sometime around March right + + + align:start position:0% +installed it sometime around March right +when the snow started to melt and the + + align:start position:0% +when the snow started to melt and the + + + align:start position:0% +when the snow started to melt and the +sun was right around here right and so + + align:start position:0% +sun was right around here right and so + + + align:start position:0% +sun was right around here right and so +you were the angle was around there and + + align:start position:0% +you were the angle was around there and + + + align:start position:0% +you were the angle was around there and +it made it into the trash collectors but + + align:start position:0% +it made it into the trash collectors but + + + align:start position:0% +it made it into the trash collectors but +you know as a summer came along it it + + align:start position:0% +you know as a summer came along it it + + + align:start position:0% +you know as a summer came along it it +got shaded so it's something to keep in + + align:start position:0% +got shaded so it's something to keep in + + + align:start position:0% +got shaded so it's something to keep in +mind um when doing a solar installation + + align:start position:0% +mind um when doing a solar installation + + + align:start position:0% +mind um when doing a solar installation +it is important to calculate these + + align:start position:0% +it is important to calculate these + + + align:start position:0% +it is important to calculate these +things and I just pick out one small + + align:start position:0% +things and I just pick out one small + + + align:start position:0% +things and I just pick out one small +example I'd encourage you to walk + + align:start position:0% +example I'd encourage you to walk + + + align:start position:0% +example I'd encourage you to walk +through I was going to have that be a + + align:start position:0% +through I was going to have that be a + + + align:start position:0% +through I was going to have that be a +small little in-class example but since + + align:start position:0% +small little in-class example but since + + + align:start position:0% +small little in-class example but since +we're running short on time um I'll just + + align:start position:0% +we're running short on time um I'll just + + + align:start position:0% +we're running short on time um I'll just +give it to you like that okay fixed + + align:start position:0% +give it to you like that okay fixed + + + align:start position:0% +give it to you like that okay fixed +versus tracking systems so if the Sun is + + align:start position:0% +versus tracking systems so if the Sun is + + + align:start position:0% +versus tracking systems so if the Sun is +moving uh as a function of season and as + + align:start position:0% +moving uh as a function of season and as + + + align:start position:0% +moving uh as a function of season and as +a function of time of day throughout the + + align:start position:0% +a function of time of day throughout the + + + align:start position:0% +a function of time of day throughout the +sky and we can see that very nicely uh + + align:start position:0% +sky and we can see that very nicely uh + + + align:start position:0% +sky and we can see that very nicely uh +again through our demo right here so if + + align:start position:0% +again through our demo right here so if + + + align:start position:0% +again through our demo right here so if +if the Sun is is actually moving um one + + align:start position:0% +if the Sun is is actually moving um one + + + align:start position:0% +if the Sun is is actually moving um one +embodiment would say okay I know more or + + align:start position:0% +embodiment would say okay I know more or + + + align:start position:0% +embodiment would say okay I know more or +less what the Sun is going to do as a + + align:start position:0% +less what the Sun is going to do as a + + + align:start position:0% +less what the Sun is going to do as a +function of season forget the deal + + align:start position:0% +function of season forget the deal + + + align:start position:0% +function of season forget the deal +variations but just the seasonal + + align:start position:0% +variations but just the seasonal + + + align:start position:0% +variations but just the seasonal +variations I know that the sun is going + + align:start position:0% +variations I know that the sun is going + + + align:start position:0% +variations I know that the sun is going +to be on average somewhere around here + + align:start position:0% +to be on average somewhere around here + + + align:start position:0% +to be on average somewhere around here +somewhere around my latitude so if I + + align:start position:0% +somewhere around my latitude so if I + + + align:start position:0% +somewhere around my latitude so if I +point my panel at Latitude tilt + + align:start position:0% +point my panel at Latitude tilt + + + align:start position:0% +point my panel at Latitude tilt +right since this angle was what was it + + align:start position:0% +right since this angle was what was it + + + align:start position:0% +right since this angle was what was it +41 + 23 this angle was 41 minus 23 so + + align:start position:0% +41 + 23 this angle was 41 minus 23 so + + + align:start position:0% +41 + 23 this angle was 41 minus 23 so +this one would be right around 41 + + align:start position:0% +this one would be right around 41 + + + align:start position:0% +this one would be right around 41 +latitude so if I aim my solar panels at + + align:start position:0% +latitude so if I aim my solar panels at + + + align:start position:0% +latitude so if I aim my solar panels at +Latitude tilt then I'm going to get on + + align:start position:0% +Latitude tilt then I'm going to get on + + + align:start position:0% +Latitude tilt then I'm going to get on +average some pretty decent power + + align:start position:0% +average some pretty decent power + + + align:start position:0% +average some pretty decent power +throughout the year I'll have a little + + align:start position:0% +throughout the year I'll have a little + + + align:start position:0% +throughout the year I'll have a little +less in Winter a little more in summer + + align:start position:0% +less in Winter a little more in summer + + + align:start position:0% +less in Winter a little more in summer +um because well just because of the + + align:start position:0% +um because well just because of the + + + align:start position:0% +um because well just because of the +amount of solar resources available but + + align:start position:0% +amount of solar resources available but + + + align:start position:0% +amount of solar resources available but +all in all I'll be I'll be all right um + + align:start position:0% +all in all I'll be I'll be all right um + + + align:start position:0% +all in all I'll be I'll be all right um +at most I'll be off by + + align:start position:0% +at most I'll be off by + + + align:start position:0% +at most I'll be off by +232° um you can do that and that's + + align:start position:0% +232° um you can do that and that's + + + align:start position:0% +232° um you can do that and that's +called fixed latitude tilt and typically + + align:start position:0% +called fixed latitude tilt and typically + + + align:start position:0% +called fixed latitude tilt and typically +you'll face the panels South + + align:start position:0% +you'll face the panels South + + + align:start position:0% +you'll face the panels South +approximately we'll get to that in a + + align:start position:0% +approximately we'll get to that in a + + + align:start position:0% +approximately we'll get to that in a +minute depends on local weather patterns + + align:start position:0% +minute depends on local weather patterns + + + align:start position:0% +minute depends on local weather patterns +if you have fog in the morning for + + align:start position:0% +if you have fog in the morning for + + + align:start position:0% +if you have fog in the morning for +instance you want to face them a little + + align:start position:0% +instance you want to face them a little + + + align:start position:0% +instance you want to face them a little +to the west but um but we'll face them + + align:start position:0% +to the west but um but we'll face them + + + align:start position:0% +to the west but um but we'll face them +South and a Latitude tilt up or we can + + align:start position:0% +South and a Latitude tilt up or we can + + + align:start position:0% +South and a Latitude tilt up or we can +decide no let's actually track the sun + + align:start position:0% +decide no let's actually track the sun + + + align:start position:0% +decide no let's actually track the sun +throughout the sky throughout the day + + align:start position:0% +throughout the sky throughout the day + + + align:start position:0% +throughout the sky throughout the day +and so we'll start in the east in the + + align:start position:0% +and so we'll start in the east in the + + + align:start position:0% +and so we'll start in the east in the +morning and have it rotating through on + + align:start position:0% +morning and have it rotating through on + + + align:start position:0% +morning and have it rotating through on +one axis tracker throughout the day or + + align:start position:0% +one axis tracker throughout the day or + + + align:start position:0% +one axis tracker throughout the day or +we can have a two axis Tracker Where It + + align:start position:0% +we can have a two axis Tracker Where It + + + align:start position:0% +we can have a two axis Tracker Where It +rotates to follow the sun throughout the + + align:start position:0% +rotates to follow the sun throughout the + + + align:start position:0% +rotates to follow the sun throughout the +seasons as well a kind of a North South + + align:start position:0% +seasons as well a kind of a North South + + + align:start position:0% +seasons as well a kind of a North South +tilt and that's what's plotted right + + align:start position:0% +tilt and that's what's plotted right + + + align:start position:0% +tilt and that's what's plotted right +here this is a a quick a quick + + align:start position:0% +here this is a a quick a quick + + + align:start position:0% +here this is a a quick a quick +approximation um of the uh fixed + + align:start position:0% +approximation um of the uh fixed + + + align:start position:0% +approximation um of the uh fixed +one-axis and two axis trackers for a + + align:start position:0% +one-axis and two axis trackers for a + + + align:start position:0% +one-axis and two axis trackers for a +given system in Boston using a + + align:start position:0% +given system in Boston using a + + + align:start position:0% +given system in Boston using a +simulation tool called PV Watts there's + + align:start position:0% +simulation tool called PV Watts there's + + + align:start position:0% +simulation tool called PV Watts there's +a link to that it's uh based on the + + align:start position:0% +a link to that it's uh based on the + + + align:start position:0% +a link to that it's uh based on the +national renewable energy laboratory + + align:start position:0% +national renewable energy laboratory + + + align:start position:0% +national renewable energy laboratory +website there's a link to that at the + + align:start position:0% +website there's a link to that at the + + + align:start position:0% +website there's a link to that at the +end of the the slides but this shows you + + align:start position:0% +end of the the slides but this shows you + + + align:start position:0% +end of the the slides but this shows you +the total system output in terms of + + align:start position:0% +the total system output in terms of + + + align:start position:0% +the total system output in terms of +kilowatt hours um in terms of hours per + + align:start position:0% +kilowatt hours um in terms of hours per + + + align:start position:0% +kilowatt hours um in terms of hours per +day um I think yeah it's a little bit of + + align:start position:0% +day um I think yeah it's a little bit of + + + align:start position:0% +day um I think yeah it's a little bit of +an odd units there on the y- AIS but it + + align:start position:0% +an odd units there on the y- AIS but it + + + align:start position:0% +an odd units there on the y- AIS but it +it shows you the um the relative gain + + align:start position:0% +it shows you the um the relative gain + + + align:start position:0% +it shows you the um the relative gain +that you would get by going to a + + align:start position:0% +that you would get by going to a + + + align:start position:0% +that you would get by going to a +one-axis and then finally a two-axis + + align:start position:0% +one-axis and then finally a two-axis + + + align:start position:0% +one-axis and then finally a two-axis +Tracker so in many places it makes sense + + align:start position:0% +Tracker so in many places it makes sense + + + align:start position:0% +Tracker so in many places it makes sense +to go to a one-axis Tracker since + + align:start position:0% +to go to a one-axis Tracker since + + + align:start position:0% +to go to a one-axis Tracker since +especially you broaden out the peak near + + align:start position:0% +especially you broaden out the peak near + + + align:start position:0% +especially you broaden out the peak near +the peak hours of the day and that's + + align:start position:0% +the peak hours of the day and that's + + + align:start position:0% +the peak hours of the day and that's +that's really good um but not always + + align:start position:0% +that's really good um but not always + + + align:start position:0% +that's really good um but not always +does it make sense financially to go to + + align:start position:0% +does it make sense financially to go to + + + align:start position:0% +does it make sense financially to go to +two axis track or you're adding another + + align:start position:0% +two axis track or you're adding another + + + align:start position:0% +two axis track or you're adding another +motor onto that thing it's really not + + align:start position:0% +motor onto that thing it's really not + + + align:start position:0% +motor onto that thing it's really not +gaining you that much um obviously you + + align:start position:0% +gaining you that much um obviously you + + + align:start position:0% +gaining you that much um obviously you +have to to calculate it out uh yourself + + align:start position:0% +have to to calculate it out uh yourself + + + align:start position:0% +have to to calculate it out uh yourself +for that specific location but by and + + align:start position:0% +for that specific location but by and + + + align:start position:0% +for that specific location but by and +large a generality one AIS tracker makes + + align:start position:0% +large a generality one AIS tracker makes + + + align:start position:0% +large a generality one AIS tracker makes +sense for a flat panel now if you have + + align:start position:0% +sense for a flat panel now if you have + + + align:start position:0% +sense for a flat panel now if you have +concentrator lens in the front and it + + align:start position:0% +concentrator lens in the front and it + + + align:start position:0% +concentrator lens in the front and it +has to be looking directly at the sun + + align:start position:0% +has to be looking directly at the sun + + + align:start position:0% +has to be looking directly at the sun +then you're kind of forced to go to two + + align:start position:0% +then you're kind of forced to go to two + + + align:start position:0% +then you're kind of forced to go to two +axis + + align:start position:0% +axis + + + align:start position:0% +axis +tracker okay and there you have your + + align:start position:0% +tracker okay and there you have your + + + align:start position:0% +tracker okay and there you have your +total system output which is just the + + align:start position:0% +total system output which is just the + + + align:start position:0% +total system output which is just the +integral under the curve uh over the + + align:start position:0% +integral under the curve uh over the + + + align:start position:0% +integral under the curve uh over the +entire + + align:start position:0% +entire + + + align:start position:0% +entire +year so definitions should have done + + align:start position:0% +year so definitions should have done + + + align:start position:0% +year so definitions should have done +this before but direct sunlight looking + + align:start position:0% +this before but direct sunlight looking + + + align:start position:0% +this before but direct sunlight looking +directly at the Sun and then diffuse + + align:start position:0% +directly at the Sun and then diffuse + + + align:start position:0% +directly at the Sun and then diffuse +sunlight or scattered light coming off + + align:start position:0% +sunlight or scattered light coming off + + + align:start position:0% +sunlight or scattered light coming off +of other things right so diffus sunlight + + align:start position:0% +of other things right so diffus sunlight + + + align:start position:0% +of other things right so diffus sunlight +would be um uh coming from the other uh + + align:start position:0% +would be um uh coming from the other uh + + + align:start position:0% +would be um uh coming from the other uh +angles in other directions in the sky + + align:start position:0% +angles in other directions in the sky + + + align:start position:0% +angles in other directions in the sky +the direct sunlight would pretty much be + + align:start position:0% +the direct sunlight would pretty much be + + + align:start position:0% +the direct sunlight would pretty much be +at the sun plus or minus a few + + align:start position:0% +at the sun plus or minus a few + + + align:start position:0% +at the sun plus or minus a few +degrees and we have different ways of + + align:start position:0% +degrees and we have different ways of + + + align:start position:0% +degrees and we have different ways of +measuring the uh the this would be flat + + align:start position:0% +measuring the uh the this would be flat + + + align:start position:0% +measuring the uh the this would be flat +plate up there on the upper left it says + + align:start position:0% +plate up there on the upper left it says + + + align:start position:0% +plate up there on the upper left it says +flat plate facing south latitude tilt + + align:start position:0% +flat plate facing south latitude tilt + + + align:start position:0% +flat plate facing south latitude tilt +just like we said it's facing south in + + align:start position:0% +just like we said it's facing south in + + + align:start position:0% +just like we said it's facing south in +the United States that's good um + + align:start position:0% +the United States that's good um + + + align:start position:0% +the United States that's good um +latitude tilt meaning it's tilted at our + + align:start position:0% +latitude tilt meaning it's tilted at our + + + align:start position:0% +latitude tilt meaning it's tilted at our +latitude so if we go from the southern + + align:start position:0% +latitude so if we go from the southern + + + align:start position:0% +latitude so if we go from the southern +tip of Florida and Texas up to uh the + + align:start position:0% +tip of Florida and Texas up to uh the + + + align:start position:0% +tip of Florida and Texas up to uh the +northern tip of Minnesota we'll be uh + + align:start position:0% +northern tip of Minnesota we'll be uh + + + align:start position:0% +northern tip of Minnesota we'll be uh +tilting it uh more and more toward the + + align:start position:0% +tilting it uh more and more toward the + + + align:start position:0% +tilting it uh more and more toward the +South like this going from Texas to + + align:start position:0% +South like this going from Texas to + + + align:start position:0% +South like this going from Texas to +Minnesota right from Texas to Minnesota + + align:start position:0% +Minnesota right from Texas to Minnesota + + + align:start position:0% +Minnesota right from Texas to Minnesota +and um so latitude tilt facing south + + align:start position:0% +and um so latitude tilt facing south + + + align:start position:0% +and um so latitude tilt facing south +flat plate this is essentially + + align:start position:0% +flat plate this is essentially + + + align:start position:0% +flat plate this is essentially +accumulating all of the sunlight the + + align:start position:0% +accumulating all of the sunlight the + + + align:start position:0% +accumulating all of the sunlight the +direct and the scattered light because + + align:start position:0% +direct and the scattered light because + + + align:start position:0% +direct and the scattered light because +it's all being collected by that flat + + align:start position:0% +it's all being collected by that flat + + + align:start position:0% +it's all being collected by that flat +plate there this map on the other hand + + align:start position:0% +plate there this map on the other hand + + + align:start position:0% +plate there this map on the other hand +is for a two AIS tracker and it's + + align:start position:0% +is for a two AIS tracker and it's + + + align:start position:0% +is for a two AIS tracker and it's +looking at the sun plus or minus 2 and a + + align:start position:0% +looking at the sun plus or minus 2 and a + + + align:start position:0% +looking at the sun plus or minus 2 and a +half degrees and so it's really only + + align:start position:0% +half degrees and so it's really only + + + align:start position:0% +half degrees and so it's really only +picking up + + align:start position:0% +picking up + + + align:start position:0% +picking up +this right here out of the sky and when + + align:start position:0% +this right here out of the sky and when + + + align:start position:0% +this right here out of the sky and when +it's sunny all the time you're golden + + align:start position:0% +it's sunny all the time you're golden + + + align:start position:0% +it's sunny all the time you're golden +you're tracking the sun you're actually + + align:start position:0% +you're tracking the sun you're actually + + + align:start position:0% +you're tracking the sun you're actually +getting more energy than you would if + + align:start position:0% +getting more energy than you would if + + + align:start position:0% +getting more energy than you would if +you just had a flat plate because the + + align:start position:0% +you just had a flat plate because the + + + align:start position:0% +you just had a flat plate because the +cosine Theta angle is changing + + align:start position:0% +cosine Theta angle is changing + + + align:start position:0% +cosine Theta angle is changing +throughout the day if you have a flat + + align:start position:0% +throughout the day if you have a flat + + + align:start position:0% +throughout the day if you have a flat +plate when the sun is in the morning + + align:start position:0% +plate when the sun is in the morning + + + align:start position:0% +plate when the sun is in the morning +time you have a flat plate like this so + + align:start position:0% +time you have a flat plate like this so + + + align:start position:0% +time you have a flat plate like this so +if my sunlight is coming in like this + + align:start position:0% +if my sunlight is coming in like this + + + align:start position:0% +if my sunlight is coming in like this +and I do cosine Theta of the angle I'm + + align:start position:0% +and I do cosine Theta of the angle I'm + + + align:start position:0% +and I do cosine Theta of the angle I'm +only getting a very small amount of the + + align:start position:0% +only getting a very small amount of the + + + align:start position:0% +only getting a very small amount of the +incident sunlight projected onto this + + align:start position:0% +incident sunlight projected onto this + + + align:start position:0% +incident sunlight projected onto this +plate right here whereas in the middle + + align:start position:0% +plate right here whereas in the middle + + + align:start position:0% +plate right here whereas in the middle +of the day now cosine Theta is one I get + + align:start position:0% +of the day now cosine Theta is one I get + + + align:start position:0% +of the day now cosine Theta is one I get +the full size light but if I have for + + align:start position:0% +the full size light but if I have for + + + align:start position:0% +the full size light but if I have for +instance uh a Tracker I would be able to + + align:start position:0% +instance uh a Tracker I would be able to + + + align:start position:0% +instance uh a Tracker I would be able to +face this panel uh du East and then + + align:start position:0% +face this panel uh du East and then + + + align:start position:0% +face this panel uh du East and then +track it throughout the day and that's + + align:start position:0% +track it throughout the day and that's + + + align:start position:0% +track it throughout the day and that's +where I'd get this additional energy + + align:start position:0% +where I'd get this additional energy + + + align:start position:0% +where I'd get this additional energy +boost here in the mornings right right + + align:start position:0% +boost here in the mornings right right + + + align:start position:0% +boost here in the mornings right right +there from the tracking system so if I + + align:start position:0% +there from the tracking system so if I + + + align:start position:0% +there from the tracking system so if I +have a Tracker I get a big gain in the + + align:start position:0% +have a Tracker I get a big gain in the + + + align:start position:0% +have a Tracker I get a big gain in the +places that have a lot of direct + + align:start position:0% +places that have a lot of direct + + + align:start position:0% +places that have a lot of direct +sun and if I'm only looking at a very + + align:start position:0% +sun and if I'm only looking at a very + + + align:start position:0% +sun and if I'm only looking at a very +small solid angle of the sky if I'm only + + align:start position:0% +small solid angle of the sky if I'm only + + + align:start position:0% +small solid angle of the sky if I'm only +looking at say this little portion of + + align:start position:0% +looking at say this little portion of + + + align:start position:0% +looking at say this little portion of +the sun on cloudy days most of the + + align:start position:0% +the sun on cloudy days most of the + + + align:start position:0% +the sun on cloudy days most of the +sunlight is coming off of the diffuse + + align:start position:0% +sunlight is coming off of the diffuse + + + align:start position:0% +sunlight is coming off of the diffuse +light not from the Sun if I have a flat + + align:start position:0% +light not from the Sun if I have a flat + + + align:start position:0% +light not from the Sun if I have a flat +plate I win if I have a concentrator I + + align:start position:0% +plate I win if I have a concentrator I + + + align:start position:0% +plate I win if I have a concentrator I +lose on a cloudy day and so that's why + + align:start position:0% +lose on a cloudy day and so that's why + + + align:start position:0% +lose on a cloudy day and so that's why +in some of the regions of the United + + align:start position:0% +in some of the regions of the United + + + align:start position:0% +in some of the regions of the United +States that are notoriously cloudy I + + align:start position:0% +States that are notoriously cloudy I + + + align:start position:0% +States that are notoriously cloudy I +won't point to anyone in particular um + + align:start position:0% +won't point to anyone in particular um + + + align:start position:0% +won't point to anyone in particular um +it's actually uh better for + + align:start position:0% +it's actually uh better for + + + align:start position:0% +it's actually uh better for +non-concentrating solar in terms of + + align:start position:0% +non-concentrating solar in terms of + + + align:start position:0% +non-concentrating solar in terms of +total energy output and in other regions + + align:start position:0% +total energy output and in other regions + + + align:start position:0% +total energy output and in other regions +of the United States where we have a lot + + align:start position:0% +of the United States where we have a lot + + + align:start position:0% +of the United States where we have a lot +of sunny days you start having two AIS + + align:start position:0% +of sunny days you start having two AIS + + + align:start position:0% +of sunny days you start having two AIS +trackers making sense and it's just + + align:start position:0% +trackers making sense and it's just + + + align:start position:0% +trackers making sense and it's just +really the ratio of these two maps + + align:start position:0% +really the ratio of these two maps + + + align:start position:0% +really the ratio of these two maps +oopsie this one which is flat plate and + + align:start position:0% +oopsie this one which is flat plate and + + + align:start position:0% +oopsie this one which is flat plate and +that one which is concentrator you see + + align:start position:0% +that one which is concentrator you see + + + align:start position:0% +that one which is concentrator you see +over here we win if we go for the + + align:start position:0% +over here we win if we go for the + + + align:start position:0% +over here we win if we go for the +concentrator and over here we get more + + align:start position:0% +concentrator and over here we get more + + + align:start position:0% +concentrator and over here we get more +energy Out oopsie more energy out if we + + align:start position:0% +energy Out oopsie more energy out if we + + + align:start position:0% +energy Out oopsie more energy out if we +use the flat plate Now That's Just + + align:start position:0% +use the flat plate Now That's Just + + + align:start position:0% +use the flat plate Now That's Just +Energy obviously cost in economics + + align:start position:0% +Energy obviously cost in economics + + + align:start position:0% +Energy obviously cost in economics +factors in what it what it takes to + + align:start position:0% +factors in what it what it takes to + + + align:start position:0% +factors in what it what it takes to +install + + align:start position:0% +install + + + align:start position:0% +install +it okay and um weather patterns I + + align:start position:0% +it okay and um weather patterns I + + + align:start position:0% +it okay and um weather patterns I +promise I'd get back to this um + + align:start position:0% +promise I'd get back to this um + + + align:start position:0% +promise I'd get back to this um +interesting to note that right near the + + align:start position:0% +interesting to note that right near the + + + align:start position:0% +interesting to note that right near the +equation + + align:start position:0% +equation + + + align:start position:0% +equation +we have this uh drop of the insulation + + align:start position:0% +we have this uh drop of the insulation + + + align:start position:0% +we have this uh drop of the insulation +and uh there are these beautiful Maps + + align:start position:0% +and uh there are these beautiful Maps + + + align:start position:0% +and uh there are these beautiful Maps +put out by again by this na NASA Earth + + align:start position:0% +put out by again by this na NASA Earth + + + align:start position:0% +put out by again by this na NASA Earth +Observatory that show you the cloud + + align:start position:0% +Observatory that show you the cloud + + + align:start position:0% +Observatory that show you the cloud +fraction coverage of particular spots + + align:start position:0% +fraction coverage of particular spots + + + align:start position:0% +fraction coverage of particular spots +around the planet and you can see that + + align:start position:0% +around the planet and you can see that + + + align:start position:0% +around the planet and you can see that +right near the equators typically we + + align:start position:0% +right near the equators typically we + + + align:start position:0% +right near the equators typically we +have these uh beautiful uh tropical + + align:start position:0% +have these uh beautiful uh tropical + + + align:start position:0% +have these uh beautiful uh tropical +forests and those are um obviously the + + align:start position:0% +forests and those are um obviously the + + + align:start position:0% +forests and those are um obviously the +high cloud cover in those regions is + + align:start position:0% +high cloud cover in those regions is + + + align:start position:0% +high cloud cover in those regions is +blocking out some of the Sun and + + align:start position:0% +blocking out some of the Sun and + + + align:start position:0% +blocking out some of the Sun and +likewise you can see that dichotomy + + align:start position:0% +likewise you can see that dichotomy + + + align:start position:0% +likewise you can see that dichotomy +between Phoenix and Atlanta same + + align:start position:0% +between Phoenix and Atlanta same + + + align:start position:0% +between Phoenix and Atlanta same +latitude again again but Atlanta having + + align:start position:0% +latitude again again but Atlanta having + + + align:start position:0% +latitude again again but Atlanta having +a higher cloud coverage than Phoenix and + + align:start position:0% +a higher cloud coverage than Phoenix and + + + align:start position:0% +a higher cloud coverage than Phoenix and +hence a lower solar resource a lower + + align:start position:0% +hence a lower solar resource a lower + + + align:start position:0% +hence a lower solar resource a lower +insulation so you see all this kind of + + align:start position:0% +insulation so you see all this kind of + + + align:start position:0% +insulation so you see all this kind of +ties together that's all predictable in + + align:start position:0% +ties together that's all predictable in + + + align:start position:0% +ties together that's all predictable in +a sense this is unpredictable at a local + + align:start position:0% +a sense this is unpredictable at a local + + + align:start position:0% +a sense this is unpredictable at a local +level at for one system right if the Sun + + align:start position:0% +level at for one system right if the Sun + + + align:start position:0% +level at for one system right if the Sun +is is tracing its route through the sky + + align:start position:0% +is is tracing its route through the sky + + + align:start position:0% +is is tracing its route through the sky +and you have that envelope function that + + align:start position:0% +and you have that envelope function that + + + align:start position:0% +and you have that envelope function that +You' just spent so much effort + + align:start position:0% +You' just spent so much effort + + + align:start position:0% +You' just spent so much effort +calculating out with all your trig + + align:start position:0% +calculating out with all your trig + + + align:start position:0% +calculating out with all your trig +functions and the computer simulation + + align:start position:0% +functions and the computer simulation + + + align:start position:0% +functions and the computer simulation +the code that you've just been given + + align:start position:0% +the code that you've just been given + + + align:start position:0% +the code that you've just been given +here and now a cloud comes over some + + align:start position:0% +here and now a cloud comes over some + + + align:start position:0% +here and now a cloud comes over some +random Cloud that was very hard to and + + align:start position:0% +random Cloud that was very hard to and + + + align:start position:0% +random Cloud that was very hard to and +you just have one panel one tiny little + + align:start position:0% +you just have one panel one tiny little + + + align:start position:0% +you just have one panel one tiny little +thing like this and the cloud goes over + + align:start position:0% +thing like this and the cloud goes over + + + align:start position:0% +thing like this and the cloud goes over +it boom all of a sudden you get a drop + + align:start position:0% +it boom all of a sudden you get a drop + + + align:start position:0% +it boom all of a sudden you get a drop +in your uh instantaneous uh Power output + + align:start position:0% +in your uh instantaneous uh Power output + + + align:start position:0% +in your uh instantaneous uh Power output +boom drops again another Cloud drops + + align:start position:0% +boom drops again another Cloud drops + + + align:start position:0% +boom drops again another Cloud drops +again and then a thunderstorm in the + + align:start position:0% +again and then a thunderstorm in the + + + align:start position:0% +again and then a thunderstorm in the +afternoon so a meteorologist could have + + align:start position:0% +afternoon so a meteorologist could have + + + align:start position:0% +afternoon so a meteorologist could have +told you that this thunderstorm was + + align:start position:0% +told you that this thunderstorm was + + + align:start position:0% +told you that this thunderstorm was +coming but a meteorologist would be hard + + align:start position:0% +coming but a meteorologist would be hard + + + align:start position:0% +coming but a meteorologist would be hard +pressed to be able to predict the + + align:start position:0% +pressed to be able to predict the + + + align:start position:0% +pressed to be able to predict the +evolution of a tiny little Cloud over + + align:start position:0% +evolution of a tiny little Cloud over + + + align:start position:0% +evolution of a tiny little Cloud over +your system and so um the question is to + + align:start position:0% +your system and so um the question is to + + + align:start position:0% +your system and so um the question is to +what degree are these weather these + + align:start position:0% +what degree are these weather these + + + align:start position:0% +what degree are these weather these +local weather patterns predictable + + align:start position:0% +local weather patterns predictable + + + align:start position:0% +local weather patterns predictable +unpredictable and hopefully some of you + + align:start position:0% +unpredictable and hopefully some of you + + + align:start position:0% +unpredictable and hopefully some of you +over this class will be able to help + + align:start position:0% +over this class will be able to help + + + align:start position:0% +over this class will be able to help +answer that question uh by analyzing + + align:start position:0% +answer that question uh by analyzing + + + align:start position:0% +answer that question uh by analyzing +data from tens of thousands of systems + + align:start position:0% +data from tens of thousands of systems + + + align:start position:0% +data from tens of thousands of systems +that have been installed throughout + + align:start position:0% +that have been installed throughout + + + align:start position:0% +that have been installed throughout +California in local GE geographical + + align:start position:0% +California in local GE geographical + + + align:start position:0% +California in local GE geographical +systems for example in the Los Angeles + + align:start position:0% +systems for example in the Los Angeles + + + align:start position:0% +systems for example in the Los Angeles +region San Francisco region and so forth + + align:start position:0% +region San Francisco region and so forth + + + align:start position:0% +region San Francisco region and so forth +if you start averaging the curves the uh + + align:start position:0% +if you start averaging the curves the uh + + + align:start position:0% +if you start averaging the curves the uh +energy outputs as a function of time + + align:start position:0% +energy outputs as a function of time + + + align:start position:0% +energy outputs as a function of time +from a variety of systems throughout a + + align:start position:0% +from a variety of systems throughout a + + + align:start position:0% +from a variety of systems throughout a +neighborhood you can probably average + + align:start position:0% +neighborhood you can probably average + + + align:start position:0% +neighborhood you can probably average +out the small tiny clouds you probably + + align:start position:0% +out the small tiny clouds you probably + + + align:start position:0% +out the small tiny clouds you probably +can't average out the thunderstorm but + + align:start position:0% +can't average out the thunderstorm but + + + align:start position:0% +can't average out the thunderstorm but +you probably could have PR predicted + + align:start position:0% +you probably could have PR predicted + + + align:start position:0% +you probably could have PR predicted +that the the thunderstorm would have + + align:start position:0% +that the the thunderstorm would have + + + align:start position:0% +that the the thunderstorm would have +come along right and so this is a hot + + align:start position:0% +come along right and so this is a hot + + + align:start position:0% +come along right and so this is a hot +area of solar research at the systems + + align:start position:0% +area of solar research at the systems + + + align:start position:0% +area of solar research at the systems +level is trying to understand to what + + align:start position:0% +level is trying to understand to what + + + align:start position:0% +level is trying to understand to what +degree are PV systems predictable to + + align:start position:0% +degree are PV systems predictable to + + + align:start position:0% +degree are PV systems predictable to +what degree can the power output of a PV + + align:start position:0% +what degree can the power output of a PV + + + align:start position:0% +what degree can the power output of a PV +system or an ensemble of PV systems be + + align:start position:0% +system or an ensemble of PV systems be + + + align:start position:0% +system or an ensemble of PV systems be +predicted in advance uh so we don't wind + + align:start position:0% +predicted in advance uh so we don't wind + + + align:start position:0% +predicted in advance uh so we don't wind +up in a situation where all of a sudden + + align:start position:0% +up in a situation where all of a sudden + + + align:start position:0% +up in a situation where all of a sudden +we have this catastrophic drop of + + align:start position:0% +we have this catastrophic drop of + + + align:start position:0% +we have this catastrophic drop of +accumulative PV system output of say 30% + + align:start position:0% +accumulative PV system output of say 30% + + + align:start position:0% +accumulative PV system output of say 30% +and meanwhile it's a hot summer day + + align:start position:0% +and meanwhile it's a hot summer day + + + align:start position:0% +and meanwhile it's a hot summer day +everybody's air conditions are going and + + align:start position:0% +everybody's air conditions are going and + + + align:start position:0% +everybody's air conditions are going and +we cause failure of the power grid kind + + align:start position:0% +we cause failure of the power grid kind + + + align:start position:0% +we cause failure of the power grid kind +of worse worst case + + align:start position:0% +of worse worst case + + + align:start position:0% +of worse worst case +scenario so this boils down to + + align:start position:0% +scenario so this boils down to + + + align:start position:0% +scenario so this boils down to +intermittency with the shorttime + + align:start position:0% +intermittency with the shorttime + + + align:start position:0% +intermittency with the shorttime +constants tend to be less predictable um + + align:start position:0% +constants tend to be less predictable um + + + align:start position:0% +constants tend to be less predictable um +cloud cover and it's relevant for + + align:start position:0% +cloud cover and it's relevant for + + + align:start position:0% +cloud cover and it's relevant for +predicting power supply reliability and + + align:start position:0% +predicting power supply reliability and + + + align:start position:0% +predicting power supply reliability and +the longer time constants tend to be + + align:start position:0% +the longer time constants tend to be + + + align:start position:0% +the longer time constants tend to be +more predictable the urinal or seasonal + + align:start position:0% +more predictable the urinal or seasonal + + + align:start position:0% +more predictable the urinal or seasonal +variations um and these are relevant to + + align:start position:0% +variations um and these are relevant to + + + align:start position:0% +variations um and these are relevant to +calculating total en energy output + + align:start position:0% +calculating total en energy output + + + align:start position:0% +calculating total en energy output +annually and often times when we just + + align:start position:0% +annually and often times when we just + + + align:start position:0% +annually and often times when we just +work off of these longtime constant + + align:start position:0% +work off of these longtime constant + + + align:start position:0% +work off of these longtime constant +variability issues we're assuming we + + align:start position:0% +variability issues we're assuming we + + + align:start position:0% +variability issues we're assuming we +have access to easy + + align:start position:0% +have access to easy + + + align:start position:0% +have access to easy +storage right now the solar panels on + + align:start position:0% +storage right now the solar panels on + + + align:start position:0% +storage right now the solar panels on +top of my roof they're producing in + + align:start position:0% +top of my roof they're producing in + + + align:start position:0% +top of my roof they're producing in +excess of what we're consuming right now + + align:start position:0% +excess of what we're consuming right now + + + align:start position:0% +excess of what we're consuming right now +CU neither my wife or at home and + + align:start position:0% +CU neither my wife or at home and + + + align:start position:0% +CU neither my wife or at home and +they're injecting that power into the + + align:start position:0% +they're injecting that power into the + + + align:start position:0% +they're injecting that power into the +grid and the grid is serving as our big + + align:start position:0% +grid and the grid is serving as our big + + + align:start position:0% +grid and the grid is serving as our big +battery as our storage + + align:start position:0% +battery as our storage + + + align:start position:0% +battery as our storage +unit and I'm riding free I'm a free + + align:start position:0% +unit and I'm riding free I'm a free + + + align:start position:0% +unit and I'm riding free I'm a free +rider right now I don't pay for that + + align:start position:0% +rider right now I don't pay for that + + + align:start position:0% +rider right now I don't pay for that +service necessarily I do the endar um + + align:start position:0% +service necessarily I do the endar um + + + align:start position:0% +service necessarily I do the endar um +but they're not charging me extra for uh + + align:start position:0% +but they're not charging me extra for uh + + + align:start position:0% +but they're not charging me extra for uh +the the service of of uh of uh using the + + align:start position:0% +the the service of of uh of uh using the + + + align:start position:0% +the the service of of uh of uh using the +grid as my big + + align:start position:0% +grid as my big + + + align:start position:0% +grid as my big +battery um another thing to keep in mind + + align:start position:0% +battery um another thing to keep in mind + + + align:start position:0% +battery um another thing to keep in mind +is that we're calculating all of this on + + align:start position:0% +is that we're calculating all of this on + + + align:start position:0% +is that we're calculating all of this on +the basis of uh of of engineering and + + align:start position:0% +the basis of uh of of engineering and + + + align:start position:0% +the basis of uh of of engineering and +scientific principles we're calculating + + align:start position:0% +scientific principles we're calculating + + + align:start position:0% +scientific principles we're calculating +the solar resource which is a good + + align:start position:0% +the solar resource which is a good + + + align:start position:0% +the solar resource which is a good +important first step now if we look at + + align:start position:0% +important first step now if we look at + + + align:start position:0% +important first step now if we look at +the actual solar installations by year + + align:start position:0% +the actual solar installations by year + + + align:start position:0% +the actual solar installations by year +and by country um this is a big table + + align:start position:0% +and by country um this is a big table + + + align:start position:0% +and by country um this is a big table +but follow me on the two underlined red + + align:start position:0% +but follow me on the two underlined red + + + align:start position:0% +but follow me on the two underlined red +uh lines here deu that stands for + + align:start position:0% +uh lines here deu that stands for + + + align:start position:0% +uh lines here deu that stands for +Deutschland Germany and + + align:start position:0% +Deutschland Germany and + + + align:start position:0% +Deutschland Germany and +USA um we'll see that Germany has about + + align:start position:0% +USA um we'll see that Germany has about + + + align:start position:0% +USA um we'll see that Germany has about +seven times more solar installed + + align:start position:0% +seven times more solar installed + + + align:start position:0% +seven times more solar installed +cumulatively than the United States does + + align:start position:0% +cumulatively than the United States does + + + align:start position:0% +cumulatively than the United States does +and yet if we look at the solar resource + + align:start position:0% +and yet if we look at the solar resource + + + align:start position:0% +and yet if we look at the solar resource +in Germany relative to the US this is + + align:start position:0% +in Germany relative to the US this is + + + align:start position:0% +in Germany relative to the US this is +average annual same scale going from 900 + + align:start position:0% +average annual same scale going from 900 + + + align:start position:0% +average annual same scale going from 900 +to 1,200 kilowatt hours per kilowatt per + + align:start position:0% +to 1,200 kilowatt hours per kilowatt per + + + align:start position:0% +to 1,200 kilowatt hours per kilowatt per +year we can see that there's a lot more + + align:start position:0% +year we can see that there's a lot more + + + align:start position:0% +year we can see that there's a lot more +sun in the United States than there is + + align:start position:0% +sun in the United States than there is + + + align:start position:0% +sun in the United States than there is +in Germany so there's something else + + align:start position:0% +in Germany so there's something else + + + align:start position:0% +in Germany so there's something else +going on than just the solar resource + + align:start position:0% +going on than just the solar resource + + + align:start position:0% +going on than just the solar resource +and that's the economics that's why we + + align:start position:0% +and that's the economics that's why we + + + align:start position:0% +and that's the economics that's why we +talk about the policy and economics + + align:start position:0% +talk about the policy and economics + + + align:start position:0% +talk about the policy and economics +later on in class that's why we dedicate + + align:start position:0% +later on in class that's why we dedicate + + + align:start position:0% +later on in class that's why we dedicate +a sizable portion later on talking about + + align:start position:0% +a sizable portion later on talking about + + + align:start position:0% +a sizable portion later on talking about +that last lastly our our our final + + align:start position:0% +that last lastly our our our final + + + align:start position:0% +that last lastly our our our final +learning objective before we uh halt for + + align:start position:0% +learning objective before we uh halt for + + + align:start position:0% +learning objective before we uh halt for +for questions and for uh comments we + + align:start position:0% +for questions and for uh comments we + + + align:start position:0% +for questions and for uh comments we +need to estimate the land area needed to + + align:start position:0% +need to estimate the land area needed to + + + align:start position:0% +need to estimate the land area needed to +provide sufficient solar resource for a + + align:start position:0% +provide sufficient solar resource for a + + + align:start position:0% +provide sufficient solar resource for a +project and this is really where your + + align:start position:0% +project and this is really where your + + + align:start position:0% +project and this is really where your +homework picks up and we'll spend some + + align:start position:0% +homework picks up and we'll spend some + + + align:start position:0% +homework picks up and we'll spend some +time in recitation walking through this + + align:start position:0% +time in recitation walking through this + + + align:start position:0% +time in recitation walking through this +but um it's important to get your units + + align:start position:0% +but um it's important to get your units + + + align:start position:0% +but um it's important to get your units +right and so I want to do a quick quiz + + align:start position:0% +right and so I want to do a quick quiz + + + align:start position:0% +right and so I want to do a quick quiz +right now um think in your minds which + + align:start position:0% +right now um think in your minds which + + + align:start position:0% +right now um think in your minds which +of these uh uh properties correspond to + + align:start position:0% +of these uh uh properties correspond to + + + align:start position:0% +of these uh uh properties correspond to +which units or are described by which + + align:start position:0% +which units or are described by which + + + align:start position:0% +which units or are described by which +units over here on the right so do kind + + align:start position:0% +units over here on the right so do kind + + + align:start position:0% +units over here on the right so do kind +of a linkage in your mind one to one + + align:start position:0% +of a linkage in your mind one to one + + + align:start position:0% +of a linkage in your mind one to one +connect connect connect connect without + + align:start position:0% +connect connect connect connect without + + + align:start position:0% +connect connect connect connect without +looking at your + + align:start position:0% +looking at your + + + align:start position:0% +looking at your +slides and we'll do it in three + + align:start position:0% +slides and we'll do it in three + + + align:start position:0% +slides and we'll do it in three +two + + align:start position:0% +two + + + align:start position:0% +two +one those are your answers right so the + + align:start position:0% +one those are your answers right so the + + + align:start position:0% +one those are your answers right so the +ones that usually get confused are power + + align:start position:0% +ones that usually get confused are power + + + align:start position:0% +ones that usually get confused are power +and energy uh kilowatts and kilowatt + + align:start position:0% +and energy uh kilowatts and kilowatt + + + align:start position:0% +and energy uh kilowatts and kilowatt +hours uh the not saying this is easy but + + align:start position:0% +hours uh the not saying this is easy but + + + align:start position:0% +hours uh the not saying this is easy but +the the way to remember it the easiest + + align:start position:0% +the the way to remember it the easiest + + + align:start position:0% +the the way to remember it the easiest +way to remember it would be to remember + + align:start position:0% +way to remember it would be to remember + + + align:start position:0% +way to remember it would be to remember +that uh the power time product is equal + + align:start position:0% +that uh the power time product is equal + + + align:start position:0% +that uh the power time product is equal +to energy so if you have power + + align:start position:0% +to energy so if you have power + + + align:start position:0% +to energy so if you have power +instantaneous energy burn rate versus + + align:start position:0% +instantaneous energy burn rate versus + + + align:start position:0% +instantaneous energy burn rate versus +time some plot that looks like this if + + align:start position:0% +time some plot that looks like this if + + + align:start position:0% +time some plot that looks like this if +you take the integral of that curve + + align:start position:0% +you take the integral of that curve + + + align:start position:0% +you take the integral of that curve +that's your total + + align:start position:0% +that's your total + + + align:start position:0% +that's your total +energy so in terms of units um current + + align:start position:0% +energy so in terms of units um current + + + align:start position:0% +energy so in terms of units um current +voltage power and energy a a hairdryer + + align:start position:0% +voltage power and energy a a hairdryer + + + align:start position:0% +voltage power and energy a a hairdryer +versus a fridge which is more likely to + + align:start position:0% +versus a fridge which is more likely to + + + align:start position:0% +versus a fridge which is more likely to +blow a fuse and which is more likely to + + align:start position:0% +blow a fuse and which is more likely to + + + align:start position:0% +blow a fuse and which is more likely to +blow your + + align:start position:0% + + + + align:start position:0% + +budget blow hair dryer is more likely to + + align:start position:0% +budget blow hair dryer is more likely to + + + align:start position:0% +budget blow hair dryer is more likely to +blow a fuse why is + + align:start position:0% +blow a fuse why is + + + align:start position:0% +blow a fuse why is +that yeah High high voltage well high + + align:start position:0% +that yeah High high voltage well high + + + align:start position:0% +that yeah High high voltage well high +high current really because everything's + + align:start position:0% +high current really because everything's + + + align:start position:0% +high current really because everything's +running 120 it's a higher current it's + + align:start position:0% +running 120 it's a higher current it's + + + align:start position:0% +running 120 it's a higher current it's +pushing the the wattage up to around 15 + + align:start position:0% +pushing the the wattage up to around 15 + + + align:start position:0% +pushing the the wattage up to around 15 +17 so 1,500 1,700 Watts um and uh so + + align:start position:0% +17 so 1,500 1,700 Watts um and uh so + + + align:start position:0% +17 so 1,500 1,700 Watts um and uh so +it's running close to the 15 amp limit + + align:start position:0% +it's running close to the 15 amp limit + + + align:start position:0% +it's running close to the 15 amp limit +and the fridge on the other hand is + + align:start position:0% +and the fridge on the other hand is + + + align:start position:0% +and the fridge on the other hand is +probably in order of magnitude lower but + + align:start position:0% +probably in order of magnitude lower but + + + align:start position:0% +probably in order of magnitude lower but +the fridge is running all the time and + + align:start position:0% +the fridge is running all the time and + + + align:start position:0% +the fridge is running all the time and +your hair dryer is only running a few + + align:start position:0% +your hair dryer is only running a few + + + align:start position:0% +your hair dryer is only running a few +minutes a day right so in terms of + + align:start position:0% +minutes a day right so in terms of + + + align:start position:0% +minutes a day right so in terms of +blowing a fuse it uses a large amount of + + align:start position:0% +blowing a fuse it uses a large amount of + + + align:start position:0% +blowing a fuse it uses a large amount of +power for a very short amount of time + + align:start position:0% +power for a very short amount of time + + + align:start position:0% +power for a very short amount of time +whereas the fridge uses a smaller amount + + align:start position:0% +whereas the fridge uses a smaller amount + + + align:start position:0% +whereas the fridge uses a smaller amount +of power for a longer amount of time and + + align:start position:0% +of power for a longer amount of time and + + + align:start position:0% +of power for a longer amount of time and +the integral under that curve winds up + + align:start position:0% +the integral under that curve winds up + + + align:start position:0% +the integral under that curve winds up +being more typically than your hair + + align:start position:0% +being more typically than your hair + + + align:start position:0% +being more typically than your hair +dryer that's a total amount of energy + + align:start position:0% +dryer that's a total amount of energy + + + align:start position:0% +dryer that's a total amount of energy +and you pay by the energy you pay by the + + align:start position:0% +and you pay by the energy you pay by the + + + align:start position:0% +and you pay by the energy you pay by the +kilowatt hour to your utility company + + align:start position:0% +kilowatt hour to your utility company + + + align:start position:0% +kilowatt hour to your utility company +and that's why it would blow your + + align:start position:0% +and that's why it would blow your + + + align:start position:0% +and that's why it would blow your +budget yep oopsie so the numbers work + + align:start position:0% +budget yep oopsie so the numbers work + + + align:start position:0% +budget yep oopsie so the numbers work +out to somewhere around 1 kilowatt hour + + align:start position:0% +out to somewhere around 1 kilowatt hour + + + align:start position:0% +out to somewhere around 1 kilowatt hour +per day for the the fridge and about + + align:start position:0% +per day for the the fridge and about + + + align:start position:0% +per day for the the fridge and about +half a kilow hour a day for the + + align:start position:0% +half a kilow hour a day for the + + + align:start position:0% +half a kilow hour a day for the +hairdryer a kilowatt hour is how much in + + align:start position:0% +hairdryer a kilowatt hour is how much in + + + align:start position:0% +hairdryer a kilowatt hour is how much in +here 18 cents most people pay about 18 + + align:start position:0% +here 18 cents most people pay about 18 + + + align:start position:0% +here 18 cents most people pay about 18 +cents per kilowatt hour and so you can + + align:start position:0% +cents per kilowatt hour and so you can + + + align:start position:0% +cents per kilowatt hour and so you can +calculate how much it costs to keep + + align:start position:0% +calculate how much it costs to keep + + + align:start position:0% +calculate how much it costs to keep +things running in your house most of us + + align:start position:0% +things running in your house most of us + + + align:start position:0% +things running in your house most of us +don't usually think about that um and + + align:start position:0% +don't usually think about that um and + + + align:start position:0% +don't usually think about that um and +last last last last point in your + + align:start position:0% +last last last last point in your + + + align:start position:0% +last last last last point in your +homework assignments you're going to be + + align:start position:0% +homework assignments you're going to be + + + align:start position:0% +homework assignments you're going to be +asked to size out systems PV systems + + align:start position:0% +asked to size out systems PV systems + + + align:start position:0% +asked to size out systems PV systems +photov voltic systems in different parts + + align:start position:0% +photov voltic systems in different parts + + + align:start position:0% +photov voltic systems in different parts +of the world and the easiest way to do + + align:start position:0% +of the world and the easiest way to do + + + align:start position:0% +of the world and the easiest way to do +that is if we take a panel and we say + + align:start position:0% +that is if we take a panel and we say + + + align:start position:0% +that is if we take a panel and we say +that this panel right here is rated uh + + align:start position:0% +that this panel right here is rated uh + + + align:start position:0% +that this panel right here is rated uh +at certain amount of power right so + + align:start position:0% +at certain amount of power right so + + + align:start position:0% +at certain amount of power right so +under Peak illumination conditions when + + align:start position:0% +under Peak illumination conditions when + + + align:start position:0% +under Peak illumination conditions when +the panel is seated at incident sunlight + + align:start position:0% +the panel is seated at incident sunlight + + + align:start position:0% +the panel is seated at incident sunlight +so the cosine Theta term is is is one + + align:start position:0% +so the cosine Theta term is is is one + + + align:start position:0% +so the cosine Theta term is is is one +and the solar the incident solar + + align:start position:0% +and the solar the incident solar + + + align:start position:0% +and the solar the incident solar +resource is 1,000 watts per square meter + + align:start position:0% +resource is 1,000 watts per square meter + + + align:start position:0% +resource is 1,000 watts per square meter +so around am 1.5 conditions this panel + + align:start position:0% +so around am 1.5 conditions this panel + + + align:start position:0% +so around am 1.5 conditions this panel +right here would be producing this one's + + align:start position:0% +right here would be producing this one's + + + align:start position:0% +right here would be producing this one's +tiny it would be producing around six + + align:start position:0% +tiny it would be producing around six + + + align:start position:0% +tiny it would be producing around six +Watts Peak but most of these panels over + + align:start position:0% +Watts Peak but most of these panels over + + + align:start position:0% +Watts Peak but most of these panels over +here are producing somewhere around a + + align:start position:0% +here are producing somewhere around a + + + align:start position:0% +here are producing somewhere around a +few hundred Watts uh Peak and so the + + align:start position:0% +few hundred Watts uh Peak and so the + + + align:start position:0% +few hundred Watts uh Peak and so the +panels are rated in terms of Watt peak + + align:start position:0% +panels are rated in terms of Watt peak + + + align:start position:0% +panels are rated in terms of Watt peak +because the panel manufacturer doesn't + + align:start position:0% +because the panel manufacturer doesn't + + + align:start position:0% +because the panel manufacturer doesn't +know where you're going to install them + + align:start position:0% +know where you're going to install them + + + align:start position:0% +know where you're going to install them +you could decide that you're going to + + align:start position:0% +you could decide that you're going to + + + align:start position:0% +you could decide that you're going to +install it in Alaska in which case it's + + align:start position:0% +install it in Alaska in which case it's + + + align:start position:0% +install it in Alaska in which case it's +going to produce about half the energy + + align:start position:0% +going to produce about half the energy + + + align:start position:0% +going to produce about half the energy +that if you install it down south in the + + align:start position:0% +that if you install it down south in the + + + align:start position:0% +that if you install it down south in the +the continental US and say Arizona maybe + + align:start position:0% +the continental US and say Arizona maybe + + + align:start position:0% +the continental US and say Arizona maybe +a third of of the energy and so it + + align:start position:0% +a third of of the energy and so it + + + align:start position:0% +a third of of the energy and so it +doesn't want to rate the panel in terms + + align:start position:0% +doesn't want to rate the panel in terms + + + align:start position:0% +doesn't want to rate the panel in terms +of the energy output it's not going to + + align:start position:0% +of the energy output it's not going to + + + align:start position:0% +of the energy output it's not going to +guarantee that you're going to get a + + align:start position:0% +guarantee that you're going to get a + + + align:start position:0% +guarantee that you're going to get a +certain energy output off of the panel + + align:start position:0% +certain energy output off of the panel + + + align:start position:0% +certain energy output off of the panel +but it'll guarantee that the panel was + + align:start position:0% +but it'll guarantee that the panel was + + + align:start position:0% +but it'll guarantee that the panel was +rated at a maximum power of such and + + align:start position:0% +rated at a maximum power of such and + + + align:start position:0% +rated at a maximum power of such and +such under standard testing conditions + + align:start position:0% +such under standard testing conditions + + + align:start position:0% +such under standard testing conditions +now that's good because you can + + align:start position:0% +now that's good because you can + + + align:start position:0% +now that's good because you can +generalize it which you'll do for your + + align:start position:0% +generalize it which you'll do for your + + + align:start position:0% +generalize it which you'll do for your +homework but it also has a downside + + align:start position:0% +homework but it also has a downside + + + align:start position:0% +homework but it also has a downside +because standard testing conditions + + align:start position:0% +because standard testing conditions + + + align:start position:0% +because standard testing conditions +aren't real world conditions the panel + + align:start position:0% +aren't real world conditions the panel + + + align:start position:0% +aren't real world conditions the panel +isn't always operating at 25° C thean + + align:start position:0% +isn't always operating at 25° C thean + + + align:start position:0% +isn't always operating at 25° C thean +isn't operating always at incident + + align:start position:0% +isn't operating always at incident + + + align:start position:0% +isn't operating always at incident +sunlight normal right and so the gap + + align:start position:0% +sunlight normal right and so the gap + + + align:start position:0% +sunlight normal right and so the gap +between actually knowing how much the + + align:start position:0% +between actually knowing how much the + + + align:start position:0% +between actually knowing how much the +panel is going to Output in terms of its + + align:start position:0% +panel is going to Output in terms of its + + + align:start position:0% +panel is going to Output in terms of its +energy for a specific location and what + + align:start position:0% +energy for a specific location and what + + + align:start position:0% +energy for a specific location and what +our calculations the back of the + + align:start position:0% +our calculations the back of the + + + align:start position:0% +our calculations the back of the +envelope calculations uh will give us + + align:start position:0% +envelope calculations uh will give us + + + align:start position:0% +envelope calculations uh will give us +that Gap is uh from an economics point + + align:start position:0% +that Gap is uh from an economics point + + + align:start position:0% +that Gap is uh from an economics point +of view there's a lot of money to be + + align:start position:0% +of view there's a lot of money to be + + + align:start position:0% +of view there's a lot of money to be +made there um if you understand really + + align:start position:0% +made there um if you understand really + + + align:start position:0% +made there um if you understand really +well how much a given panel will output + + align:start position:0% +well how much a given panel will output + + + align:start position:0% +well how much a given panel will output +you can then predict to a much finer + + align:start position:0% +you can then predict to a much finer + + + align:start position:0% +you can then predict to a much finer +degree uh what you should be charging + + align:start position:0% +degree uh what you should be charging + + + align:start position:0% +degree uh what you should be charging +customer for installing panels in a + + align:start position:0% +customer for installing panels in a + + + align:start position:0% +customer for installing panels in a +particular location right um so there's + + align:start position:0% +particular location right um so there's + + + align:start position:0% +particular location right um so there's +a lot of work being done right now more + + align:start position:0% +a lot of work being done right now more + + + align:start position:0% +a lot of work being done right now more +on the business side of of of of of + + align:start position:0% +on the business side of of of of of + + + align:start position:0% +on the business side of of of of of +pulling the systems Engineers along and + + align:start position:0% +pulling the systems Engineers along and + + + align:start position:0% +pulling the systems Engineers along and +trying to increase the accuracy of + + align:start position:0% +trying to increase the accuracy of + + + align:start position:0% +trying to increase the accuracy of +predictions and so with that I will um I + + align:start position:0% +predictions and so with that I will um I + + + align:start position:0% +predictions and so with that I will um I +will leave off uh on this slide we can + + align:start position:0% +will leave off uh on this slide we can + + + align:start position:0% +will leave off uh on this slide we can +get to it during recitation tomorrow at + + align:start position:0% +get to it during recitation tomorrow at + + + align:start position:0% +get to it during recitation tomorrow at +4: I welcome your questions here at the + + align:start position:0% +4: I welcome your questions here at the + + + align:start position:0% +4: I welcome your questions here at the +front if you have any otherwise I'll see + + align:start position:0% +front if you have any otherwise I'll see + + + align:start position:0% +front if you have any otherwise I'll see +you + + align:start position:0% + + + + align:start position:0% + +tomorrow for \ No newline at end of file diff --git a/CN_TJBPv2Qs.txt b/CN_TJBPv2Qs.txt new file mode 100644 index 0000000000000000000000000000000000000000..7b2aab3719213a36028de74a164054bc9b370828 --- /dev/null +++ b/CN_TJBPv2Qs.txt @@ -0,0 +1,191 @@ +In the next variation we +consider, all random variables + +are continuous. + +For this case, we do have +a Bayes rule, once more. + +And we have worked [out] +quite a few examples. + +So there's no point, +again, in going + +through a detailed example. + +Let us just discuss +some of the issues. + +One question is when +do these models arise? + +One particular class of models +that is very useful and very + +commonly used are so-called +linear normal models. + +In these models, we, +basically, combine + +various random variables +in a linear function. + +And all the random variables of +interest are now to be normal. + +For instance, we might have +a signal, a noisy signal, + +call it Theta, which is now +a continuous valued signal. + +We receive that +signal, but corrupted + +by some noise, which is +independent from what was sent. + +And we wish to recover, on the +basis of the observation X, + +we wish to recover +the value of Theta. + +And then there are versions +of this problem that + +involve Theta vectors +instead of single values. + +So that Theta consists +of multiple components, + +and where we obtain many +measurements X. We will, + +actually, see in the +next lecture sequence, + +a quite detailed discussion +of models of this type. + +And this will be one +of our main examples + +within our study of inference. + +There will be another example +that we will see a few times, + +and this involves +estimating the parameter + +of a uniform distribution. + +So X is a random variable that's +uniform over a certain range. + +But the range itself +is random and unknown. + +And on the basis +of observations X, + +we would like to make +an estimation of what + +the true value of Theta is. + +This is an example +that you will see + +in our collection of solved +problems for this class. + +So what are the questions +in this setting, + +we wish to come up with +ways of estimating Theta, + +we form an estimator, +and the main candidates + +for estimators at this +points are, once more, + +the maximum a posteriori +probability estimator, + +which looks at this +conditional density + +and picks a value of theta that +makes this conditional density + +as large as possible. + +And then the alternative one +is the least mean squares + +estimator, which just +computes the expected value + +of Theta given X. + +For any given +estimator, we then want + +to characterize its performance. + +In this case, a natural +notion of performance + +is the distance between +our estimate, or estimator, + +from the true value of Theta. + +And commonly we use +the squared distance + +and then take the average +of that squared distance. + +So in a conditional universe +where we have already + +observed some data, +we might be interested + +in this particular +expectation, which + +is the mean squared error of +this particular estimator, + +given that we obtain +some particular data. + +Or we can average over +all possible data points + +that we might obtain +so that we look + +at the unconditional +mean squared error, which + +is a measure of the overall +performance of our estimator. + +We will be talking +about these criteria + +and the mean squared error +in a fair amount of detail + +in a subsequent +lecture sequence. \ No newline at end of file diff --git a/ENrAsRoR97I.txt b/ENrAsRoR97I.txt new file mode 100644 index 0000000000000000000000000000000000000000..74ce1f6013df46ae41aefdd36fef5c664cd756c2 --- /dev/null +++ b/ENrAsRoR97I.txt @@ -0,0 +1,1837 @@ +OPERATOR: The following content +is provided under a + +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation, or view +additional material from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: All right, so today +we're returning to + +simulations. + +And I'm going to do at first, a +little bit more abstractly, + +and then come back +to some details. + +So they're different ways to +classify simulation models. + +The first is whether it's +stochastic or deterministic. + +And the difference here is in +a deterministic simulation, + +you should get the same result +every time you run it. + +And there's a lot of uses we'll +see for deterministic + +simulations. + +And then there's stochastic +simulations, where the answer + +will differ from run to run +because there's an element of + +randomness in it. + +So here if you run it again +and again you get the same + +outcome every time, +here you may not. + +So, for example, the problem +set that's due today -- is + +that a stochastic or +deterministic simulation? + +Somebody? + +Stochastic, exactly. + +And that's what we're going +to focus on in this class, + +because one of the interesting +questions we'll see about + +stochastic simulations is, how +often do have to run them + +before you believe the answer? + +And that turns out to be +a very important issue. + +You run it once, you get +an answer, you can't + +take it to the bank. + +Because the next time you run +it, you may get a completely + +different answer. + +So that will get us a little +bit into the whole issue of + +statistical analysis. + +Another interesting dichotomy +is static vs dynamic. + +We'll look at both, but +will spend more + +time on dynamic models. + +So the issue -- it's +not my phone. + +If it's your mother, you could +feel free to take it, + +otherwise -- + +OK, no problem. + +Inevitable. + +In a dynamic situation, +time plays a role. + +And you look at how things +evolve over time. + +In a static simulation, there +is no issue with time. + +We'll be looking at both, but +most of the time we'll be + +focusing on dynamic ones. + +So an example of this kind of +thing would be a queuing + +network model. + +This is one of the most popular +and important kinds of + +dynamic simulations. + +Where you try and look at how +queues, a fancy word for + +lines, evolve over time. + +So for example, people who are +trying to decide how many + +lanes should be in a highway, +or how far apart the exits + +should be, or what should the +ratio of Fast Lane tolls to + +manually staffed tolls +should be. + +All use queuing networks to try +and answer that question. + +And we'll look at some examples +of these later + +because they are +very important. + +Particularly for things +related to + +scheduling and planning. + +A third dichotomy is discrete +vs continuous. + +Imagine, for example, trying to +analyze the flow of traffic + +along the highway. + +One way to do it, is to try and +have a simulation which + +models each vehicle. + +That would be a discrete +simulation, because you've got + +different parts. + +Alternatively, you might decide +to treat traffic as a + +flow, kind of like water flowing +through things, where + +changes in the flow can +be described by + +differential equations. + +That would lead to a +continuous model. + +Another example is, a lot of +effort has gone into analyzing + +the way blood flows through +the human body. + +You can try and model it +discretely, where you take + +each red blood cell, each white +blood cell, and look at + +how they move, or simulate +how they move. + +Or you could treat it +continuously and say, well, + +we're just going to treat blood +as a fluid, not made up + +of discrete components, and +write some equations to model + +how that fluid goes through +and then simulate that. + +In this course, we're going to +be focusing mostly on discrete + +simulations. + +Now if we think about the random +walk we looked at, + +indeed it was stochastic, +dynamic, and discrete. + +The random walk was an example +of what's called a Monte Carlo + +simulation. + +This term was coined there. + +Anyone know what that is? + +Anyone want to guess? + +It's the casino, in Monaco, +in Monte Carlo. + +It was at one time, before there +was even a Las Vegas, + +the most famous casino in +the world certainly. + +Still one of the more opulent +ones as you can see. + +And unlike Las Vegas, it's real +opulence, as opposed to + +faux opulence. + +And this term Monte Carlo +simulation, was coined by Ulam + +and Metropolis, two +mathematicians, back in 1949, + +in reference to the fact that at +Monte Carlos, people bet on + +roulette wheels, and cards on +a table, games of chance, + +where there was randomness, and +things are discrete, in + +some sense. + +And they decided, well, this is +just like gambling, and so + +they called them Monte +Carlos simulations. + +What Is it that makes +this approach work? + +And, in some sense, I won't go +into a lot of the math, but I + +would like to get some +concepts across. + +This is an application of what +are called inferential + +statistics. + +You have some sample size, some +number of points, and + +from that you try to infer +something more general. + +We always depend upon one +property when we do this. + +And that property is that, a +randomly chosen sample tends + +to exhibit the same properties +as the population from which + +it is drawn. + +So you take a population of +anything, red balls and black + +balls, or students, or steps, +and at random draw some + +sample, and you assume that +that sample has properties + +similar to the entire +population. + +So if I were to go around this +room and choose some random + +sample of you guys and write +down your hair color, we would + +be assuming that the fraction +of you with blonde hair in + +that sample would be the same +as the fraction of you with + +blonde hair in the +whole class. + +That's kind of what +this means. + +And the same would be true of +black hair, auburn hair, etc. + +So consider, for example, +flipping a coin. + +And if I were to flip it some +number of times, say 100 + +times, you might be able to, +from the proportion of heads + +and tails, be able to +infer whether or not + +the coin was fair. + +That is to say, half the times +it would be heads, in half the + +times it would be that tails, or +whether it was unfair, that + +it was somehow weighted, so that +heads would come up more + +than tails. + +And you might say if we did this +100 times and looked at + +the results, then we could make +a decision about what + +would happen in general when +we looked at the coin. + +So let's look in an example +of doing that. + +So I wrote a little program, +it's on your + +handout, to flip a coin. + +So this looks like +the simulations + +we looked at before. + +I've got flip trials, which says +that the number of heads + +and tails is 0 for +i in x range. + +What is x range? + +So normally you would have +written, for i in range zero + +to num flips. + +What range does, is it creates a +list, in this case from 0 to + +99 and goes through the +list of one at a time. + +That's fine, but supposed num +flips were a billion. + +Well, range would create +a list with a + +billion numbers in it. + +Which would take a lot of +space in the computer. + +And it's kind of wasted. + +What x range says is, don't +bother creating the list just + +go through the, in this case, +the numbers one at a time. + +So it's much more efficient +than range. + +It will behave the same way as +far as the answers you get, + +but it doesn't use +as much space. + +And since some of the +simulations we'll be doing + +will have lots of trials, or +lots of flips, it's worth the + +trouble to use x range +instead of range. + +Yeah? + +Pardon? + +STUDENT: Like, why would +we ever use range + +instead of x range? + +PROFESSOR: No good reason, when +dealing with numbers, + +unless you wanted to do +something different with the + +list. But, there's +no good reason. + +The right answer for +the purposes of + +today is, no good reason. + +I typically use x range +all the time if I'm + +thinking about it. + +It was just something that +didn't seem worth introducing + +earlier in this semester. + +But good question. + +Certainly deserving of +a piece of candy. + +All right, so for i in x range, +coin is equal some + +random integer 0 or 1. + +If coin is equal to 0 then +heads, else tails. + +Well, that's pretty easy. + +And then all I'm going to do +here is go through and flip it + +a bunch of times, and +we'll get some + +answer, and do some plots. + +So let's look at an example. + +We'll try -- we'll flip 100 +coins, we'll do 100 trials and + +see what we get. + +Error in multi-line statement. + +All right, what have +I done wrong here? + +Obviously did something by +accident, edited something I + +did not intend edit. + +Anyone spot what I did wrong? + +Pardon? + +The parentheses. + +I typed where I didn't intend. + +Which line? + +Down at the bottom? + +Obviously my, here, yes, +I deleted that. + +Thank you. + +All right, so we have a couple +of figures here. + +Figure one, I'm showing +a histogram. + +The number of trials on the +y-axis and the difference + +between heads and tails , do +I have more of one than the + +other on the x-axis. + +And so we what we could see +out of my 100 trials, + +somewhere around 22 of them +came out the same, + +close to the same. + +But way over here we've +got some funny ones. + +100 and there was a +difference of 25. + +Pretty big difference. + +Another way to look at the same +data, and I'm doing this + +just to show that there are +different ways of looking at + +data, is here, what I've plotted +is each trial, the + +percent difference. + +So out of 100 flips. + +And this is normalizing it, +because if I flip a million + +coins, I might expect the +difference to be pretty big in + +absolute terms, but maybe +very small as a + +percentage of a million. + +And so here, we can again see +that as these stochastic kinds + +of things, there's a pretty +big difference, right? + +We've got one where it was over +25 percent, and several + +where it's zero. + +So the point here, we can see +from this graph, that if I'd + +done only one trial and just +assumed that was the answer as + +to whether my coin was weighted +or not, I could + +really have fooled myself. + +So the the main point is that +you need to be careful when + +you're doing these +kinds of things. + +And this green line +here is the mean. + +So it says on average, the +difference was seven precent. + +Well suppose, maybe, instead +of, flipping 100, I were to + +flip 1,000. + +Well, doesn't seem to +want to notice it. + +One more try and then I'll +just restart it, which is + +always the safest thing as +we've discussed before. + +Well, we won't panic. + +Sometimes this helps. + +If not, here we go. + +So let's say we wanted +to flip 1,000 coins. + +So now what do we think? + +Is the difference going to be +bigger or smaller than when we + +flipped 100? + +Is the average difference +between heads and tails bigger + +or smaller with 1,000 flips +than with 100 flips? + +Well, the percentage will be +smaller, but in absolute + +terms, it's probably going +to be bigger, right? + +Because I've got more +chances to stray. + +But we'll find out. + +So here we see that the mean +difference is somewhere in the + +twenties, which was much +higher than the mean + +difference for 100 flips. + +On the other hand, if we look at +the percentage, we see it's + +much lower. + +Instead of seven percent, it's +around two and a half percent + +in the main. + +There's something else +interesting to observe in + +figure two, relative to when we +looked at with 100 flips. + +What else is pretty interesting +about the + +difference between these two +figures, if you can remember + +the other one? + +Yeah? + +STUDENT: There are no zeros? + +PROFESSOR: There are no zeros. + +That's right, as it happens +there were no zeros. + +Not so surprising that it +didn't ever come out + +exactly 500, 500. + +What else? + +What was the biggest difference, +percentage-wise, + +we saw last time? + +Over 25. + +So notice how much narrower +the range is here. + +Instead of ranging from 2 to 25 +or something like that, it + +ranges from 0 to 7, or +maybe 7 and a little. + +So, by flipping more coins, the +experiment becomes more + +reproduce-able. + +I'm looks like the same because +of scaling, but in + +fact the range is +much narrower. + +Each experiment tends to give +an answer closer to all the + +other experiments. + +That's a good thing. + +It should give you confidence +that the answers are getting + +pretty close to right. + +That they're not bouncing +all over the place. + +And if I were to flip a million +coins, we would find + +the range would get +very tight. + +So notice that even though +there's similar information in + +the histogram and the plot, +different things leap out at + +you, as you look at it. + +All right, we could ask a lot of +other interesting questions + +about coins here. + +But, we'll come back to this in +a minute and look at some + +other questions. + +I want to talk again a little +bit more generally. + +It's kind of easy to think about +running a simulation to + +predict the future. + +So in some sense, we look at +this, and this predicts what + +might happen if I flipped +1,000 coins. + +That the most likely event +would be that I'd have + +something under 10 in the +difference between heads and + +tails, but that it's not +terribly unlikely that I might + +have close to 70 as +a difference. + +And if I ran more than 100 +trials I'd see more, but this + +helps me predict what +might happen. + +Now we don't always use +simulations to predict what + +might happen. + +We sometimes actually use +simulations to understand the + +current state of the world. + +So for example, if I told you +that we are going to flip + +three coins, and I wanted you +to predict the probability + +that all three would be +either heads, or all + +three would be tails. + +Well, if you'd studied any +probability, you could know + +how to do that. + +If you hadn't studied +probability, you would say, + +well, that's OK, we have a +simulation right here. + +Let's just do it. + +Here we go again. + +And so let's try it. + +Let's flip three coins, and +let's do it 4,000 times here. + +Well, that's kind +of hard to read. + +It's pretty dense. + +But we can see that the +mean here is 50. + +And, this is a little +easier to read. + +This tells us that, how many +times will the difference, + +right, be zero 3,000 +out of 4,000. + +Is that right? + +What do you think? + +Do you believe this? + +Have I done the right thing? +three coins, 4,000 flips, how + +often should they all be heads, +or how often should + +they all be tails? + +What does this tell us? + +It tells us one-fourth of the +time they'll all be-- the + +difference between, wait a +minute, how can the difference + +between -- something's wrong +with my code, right? + +Because I only have two +possible values. + +I hadn't expected this. + +I obviously messed +something up. + +Pardon? + +STUDENT: It's right. + +PROFESSOR: It's right, +because? + +STUDENT: Because you had an odd +number of flips, and when + +you split them -- + +PROFESSOR: Pardon? + +STUDENT: When you split +an odd number -- + +PROFESSOR: Exactly. + +So it is correct. + +And it gives us what we want. + +But now, let's think about +a different situation. + +Anybody got a coin here? + +Anyone give me three coins? + +I can trust somebody, I hope. + +What a cheap -- anybody got +silver dollars, would be + +preferable? + +All right, look at this. + +She's very carefully given +me three pennies. + +She had big, big money in that +purse, too, but she didn't + +want me to have it. + +All right, so I'm going to +take these three pennies, + +jiggle them up, and now ask you, +what's the probability + +that all three of +them are heads? + +Anyone want to tell me? + +It's either 0 or 1, right? + +And I can actually look +at you and tell you + +exactly which it is. + +And you can't see which it is. + +So, how should you think about +what the probability it? + +Well, you might as well assume +that it's whatever this graph + +tells you it is. + +Because the fact that you +don't have access to the + +information, means that you +really might as well treat the + +present as if it's the future. + +That it's unknown. + +And so in fact we frequently, +when there's data out there + +that we don't have access to, +we use simulations and + +probabilities to estimate, make +our best guess, about the + +current state of the world. + +And so, in fact, guessing the +value of the current state, is + +really no different from +predicting the value of a + +future state when you don't +have the information. + +In general, all right, now, +just to show that your + +precautions were unnecessary. + +Where was I? + +Right. + +In general, when we're trying +to predict the future, or in + +this case, guess the present, we +have to use information we + +already have to make our +prediction or our best guess. + +So to do that, we have to always +ask the question, is + +past behavior a good prediction +of future behavior? + +So if I flip a coin 1,000 times +and count up the heads + +and tails, is that a good +prediction what will happen + +the next time? + +This is a step people often +omit, in doing these + +predictions. + +See the recent meltdown of +the financial system. + +Where people had lots of +stochastic simulations + +predicting what the market would +do, and they were all + +wrong, because they were all +based upon assuming samples + +drawn from the past would +predict the future. + +So, as we build these models, +that's the question you always + +have to ask yourself. + +Is, in some sense, this true? + +Because usually what we're doing +is, we're choosing a + +random sample from the +past and hoping it + +predicts the future. + +And that is to say, is the +population we have available + +the same has the one +in the future. + +So it's easy to see how one +might use these kinds of + +simulations to figure out things +that are inherently + +stochastic. + +So for example, to predict +a poker hand. + +What's the probability of my +getting a full house when I + +draw this card from the deck? + +To predict the probability of +coming up with a particular + +kind of poker hand. + +Is a full house more probable +than a straight? + +Or not? + +Well, you can deal out lots of +cards, and count them up, just + +as Ulam suggested +for Solitaire. + +And that's often what we do. + +Interestingly enough though, +we can use randomized + +techniques to get solutions +to problems that are not + +inherently stochastic. + +And that's what I +want to do now. + +So, consider for example, pi. + +Many of you have probably +heard of this. + +For thousands of years, +literally, people have known + +that there is a constant, pi, +associated with circles such + +that pi times the radius squared +equals the area. + +And they've known that pi times +the diameter is equal to + +the circumference. + +So, back in the days of the +Egyptian pharaohs, it was + +known that such a constant +existed. + +In fact, it didn't acquire +the name pi + +until the 18th century. + +And so they called it +other things, but + +they knew it existed. + +And for thousands of years, +people have speculated on what + +it's value was. + +Sometime around 1650 BC, the +Egyptians said that pi was + +3.16, something called +the Rhind Papyrus, + +something they found. + +Many years later, about +1,000 years later, the + +Bible said pi was three. + +And I quote, this is describing +the specifications + +for the Great Temple of Solomon. +"He made a molten sea + +of 10 cubits from brim to brim, +round in compass, and 5 + +cubit the height thereof, and +a line of 30 cubits did + +compass it round about." So, all +right, so what we've got + +here is, we've got everything +we need to plug into these + +equations and solve for pi, +and it comes out three. + +And it does this in more than +one place in the Bible. + +I will not comment on the +theological implications of + +this assertion. + +Sarah Palin might. + +And Mike Huckabee +certainly would. + +The first theoretical +calculation of pi was carried + +out by Archimedes, a great +Greek mathematician from + +Syracuse, that was about +somewhere around 250 BC. + +And he said that pi was +somewhere between 223 divided + +by 71, and 22 divided by 7. + +This was amazingly profound. + +He knew he didn't know what the +answer was, but he had a + +way to give an upper and a lower +bound, and say it was + +somewhere between these +two values. + +And in fact if you calculate it, +the average of those two + +values is 3.1418. + +Not bad for the time. + +This was not by measurement, +he actually had a very + +interesting way of +calculating it. + +All right, so this is where it +stood, for years and years, + +because of course people forgot +the Rhind Papyrus, and + +they forgot Archimedes, and they +believed the Bible, and + +so three was used +for a long time. + +People sort of knew it wasn't +right, but still. + +Then quite interestingly, Buffon +and Laplace, two great + +French mathematicians, actually +people had better + +estimates using Archimedes' +methods long before they came + +along, proposed a way to do +it using a simulation. + +Now, since Laplace lived between +1749 and 1827, it was + +not a computer simulation. + +So I'm going to show you, +basically, the way that he + +proposed to do it. the basic +idea was you take a square, + +assume that's a square, and you +inscribe in it a quarter + +of a circle. + +So here, you have the radius +of the square r. + +And then you get some person to, +he used needles, but I'm + +going to use darts, to throw +darts at the shape. + +And some number of the darts +will land in the circle part, + +and some number of the darts +will land out here, in the + +part of the square that's not +inscribed by the circle. + +And then we can look at the +ratio of the darts in the + +shaded area divided by +the total number of + +darts in the square. + +And that's equal to the shaded +area divided by the area of + +the square. + +The notion being, if they're +landing at random in these + +places, the proportion here and +not here will depend upon + +the relative areas. + +And that certainly +makes sense. + +If this were half the area of +the square, then you'd expect + +half the darts to +land in here. + +And then as you can see in your +handout, a little simple + +algebra can take this, plus pi r +squared equals the area, you + +can solve for pi, and you can +get that pi is equal to 4, and + +I'll write it, h, where h is +the hit ratio, the number + +falling in here. + +So people sort of see why that +should work intuitively? + +And that it's a very clever idea +to use randomness to find + +a value that there's nothing +random about. + +So we can now do +the experiment. + +I need volunteers +to throw darts. + +Come on. + +Come on up. + +I need more volunteers. + +I have a lot of darts. + +Anybody else? + +Anybody? + +All right, then since you're +all in the front + +row, you get stuck. + +So now we'll try it. + +And you guys, we'll see how many +of you hit in the circle, + +and how many of you hit there. + +Go ahead, on the count of +3, everybody throw. + +1, 2, 3. + +Ohh! + +He did that on purpose. + +You'll notice Professor Grimson +isn't here today, and + +that's because I told him he was +going to have to hold the + +dart board. + +Well, what we see here is, we +ignore the ones that missed + +all together. + +And we'll see that, truly, +I'm assuming + +these are random throws. + +We have one here and two here. + +Well, your eyes will tell you +that's the wrong ratio. + +Which suggests that having +students throw darts is not + +the best way to solve +this problem. + +And so you will see in your +handout a computer + +simulation of it. + +So let's look at that. + +So this is find pi. + +So at the beginning of this +code, by the way, it's not on + +your handout, is some magic. + +I got tired of looking at big +numbers without commas + +separating the thousands +places. + +You've see me in other +lectures counting + +the number of zeros. + +What we have here is, that just +tells it I have to have + +two versions, one for the +Mac, and one for the PC. + +To set some variables that had +to write integers, things in + +general, and I'm saying here, do +it the way you would do it + +in the United States +in English. + +And UTF8 is just an extended +character code. + +Anyway, you don't need to learn +anything about this + +magic, but it's just a handy +little way to make the numbers + +easier to read. + +All right, so let's let's +try and look at it. + +There's not much interesting +to see here. + +I've done this little thing, +format ints, that uses this + +magic to say grouping equals +true, that means put a comma + +in the thousand places. + +But again, you can +ignore all that. + +The interesting part, is that +from Pylab I import star, + +import random in math. + +As some of you observed, the +order these imports matters. + +I think I sent out an email +yesterday explaining what was + +going on here. + +This was one of the things +that I knew, and probably + +should've mentioned. + +But since I knew it, I thought +everyone knew. + +Silly me. + +It was of course a dumb +thing to think. + +And then I'm going to throw +a bunch of darts. + +The other thing you'll notice +is, throw darts has a + +parameter called should plot. + +And that's because when I +throw a billion darts, I + +really don't want to try and +take the time to plot a + +billion points. + +So let's first look at +a little example. + +We'll try throwing +10,000 darts. + +And it gives me an estimated +value of pi of 3.16. + +And what we'll see here, is +that the number of darts + +thrown, the estimate +changes, right? + +When I threw one dart, the +estimate of pi was 4. + +I threw my second dart, it +dropped all the way to 3. + +And then it bounced around a +while, and then at the end, it + +starts to really stabilize +around the true value. + +You'll notice, by the way, that +what I've got here is a + +logarithmic x-axis. + +If you look at the code, you'll +see I've told it to be + +semi log x. + +And that's because I wanted you +to be able to see what was + +happening early on, where +it was fluctuating. + +But out here it's kind of +boring, because the + +fluctuations are so small. + +So that was a good +way to do it. + +All right now. + +Do I think I have enough +samples here? + +Well, I don't want you to cheat +and look at the estimate + +and say no, you don't, because +you know that's + +not the right answer. + +And, it's not even as good +as Archimedes did. + +But how could you sort of look +at the data, and get a sense + +that maybe this is not +the right answer? + +Well, even at the end, if we +look at it, it's still + +wiggling around a fair amount. + +We can zoom in. + +And it's bouncing up +and down here. + +I'm in a region, but it's sort +of makes us think that maybe + +it hasn't stabilized, right? + +You'd like it to not be +moving very much. + +Now, by the way, the other thing +we could've looked at, + +when we ran it, let's run +it again, probably get a + +different answer by the way. + +Yeah, notice the different +answer here. + +Turns out to be a better answer, +but it's just an + +accident, right? + +Notice in the beginning it +fluctuates wildly, and it + +fluctuates less wildly +at the end. + +Why is that? + +And don't just say because +it's close to right + +and it knows it. + +Why do the mathematics of this, +in some sense, tell us + +it has to fluctuate less +wildly at the end? + +Yes? + +STUDENT: [INAUDIBLE] + +PROFESSOR: Exactly, +exactly right. + +If I've only thrown two darts, +the third dart can have a big + +difference in the +average value. + +But if I've thrown a million +darts, the million and first + +can't matter very much. + +And what this tells me is, as +I want ever more digits of + +precision, I have to run a lot +more trials to get there. + +And that's often true, that +simulations can get you in the + +neighborhood quickly, but the +more precision you want, the + +number of steps grows +quite quickly. + +Now, the fact that I got such +different answers the two + +times I ran this suggests +strongly that I shouldn't + +believe either answer. + +Right? + +So we need to do +something else. + +So let's try something else. + +Let's try throwing a lot +more darts here, + +and see what we get. + +Now if you look at my code, +you'll see I'm printing + +intermediate values. + +Every million darts, I'm +printing the value. + +And I did that because the first +time I ran this on a big + +number, I was afraid I had an +infinite loop and my program + +was not working. + +So I just said, all right, let's +put a print statement in + +the loop, so I could see that +it's making progress. + +And then I decided it was just +kind of nice to look at it, to + +see what was going on here. + +So now you see that if I throw +10 million darts, I'm starting + +to get a much better estimate. + +You'll also see, as predicted, +that as I get further out, the + +value of the estimate changes +less and less with each + +million new darts, because it's +a smaller fraction of the + +total darts. + +But it's getting a lot better. + +Still not quite there. + +Let's just see what happens, +I can throw in another one. + +This is going to take +a little while. + +So I can talk while +it's running. + +Oops, what did I do here? + +So, it's going to keep on going +and going and going. + +And then if we were to run it +with this number of darts + +several times over, we would +discover that we got answers + +that were very, very similar. + +From that we can take comfort, +statistically, that we're + +really getting close to the +same answer every time, so + +we've probably thrown enough +darts to feel comfortable that + +we're doing what's statistically +the right thing. + +And that there maybe isn't +a lot of point in + +throwing more darts. + +Does that mean that we have +the right answer? + +No, not necessarily, and that's +what we're going to + +look at next week. \ No newline at end of file diff --git a/Eaei-Y5AO_E.txt b/Eaei-Y5AO_E.txt new file mode 100644 index 0000000000000000000000000000000000000000..127bfaedff2258c8746caa9f3586c7ddbb195a8d --- /dev/null +++ b/Eaei-Y5AO_E.txt @@ -0,0 +1,1211 @@ +align:start position:0% + +hi welcome back to recitation in lecture + + align:start position:0% +hi welcome back to recitation in lecture + + + align:start position:0% +hi welcome back to recitation in lecture +you talked about uh Computing + + align:start position:0% +you talked about uh Computing + + + align:start position:0% +you talked about uh Computing +derivatives by definition and one rule + + align:start position:0% +derivatives by definition and one rule + + + align:start position:0% +derivatives by definition and one rule +for computing derivatives that Professor + + align:start position:0% +for computing derivatives that Professor + + + align:start position:0% +for computing derivatives that Professor +jarrison mentioned but didn't prove was + + align:start position:0% +jarrison mentioned but didn't prove was + + + align:start position:0% +jarrison mentioned but didn't prove was +What's called the constant multiple rule + + align:start position:0% +What's called the constant multiple rule + + + align:start position:0% +What's called the constant multiple rule +so today I want to give you a proof of + + align:start position:0% +so today I want to give you a proof of + + + align:start position:0% +so today I want to give you a proof of +that rule and show you a little bit + + align:start position:0% +that rule and show you a little bit + + + align:start position:0% +that rule and show you a little bit +geometric intuition for why it works so + + align:start position:0% +geometric intuition for why it works so + + + align:start position:0% +geometric intuition for why it works so +the constant multiple rule says that if + + align:start position:0% +the constant multiple rule says that if + + + align:start position:0% +the constant multiple rule says that if +you have a constant c and a + + align:start position:0% +you have a constant c and a + + + align:start position:0% +you have a constant c and a +differentiable function f ofx that the + + align:start position:0% +differentiable function f ofx that the + + + align:start position:0% +differentiable function f ofx that the +derivative of the function C * f ofx is + + align:start position:0% +derivative of the function C * f ofx is + + + align:start position:0% +derivative of the function C * f ofx is +equal to C time the derivative of f ofx + + align:start position:0% +equal to C time the derivative of f ofx + + + align:start position:0% +equal to C time the derivative of f ofx +so just to do a quick example suppose + + align:start position:0% +so just to do a quick example suppose + + + align:start position:0% +so just to do a quick example suppose +that c were three and F ofx were the + + align:start position:0% +that c were three and F ofx were the + + + align:start position:0% +that c were three and F ofx were the +function X2 this says that the + + align:start position:0% +function X2 this says that the + + + align:start position:0% +function X2 this says that the +derivative d by DX of 3 + + align:start position:0% +derivative d by DX of 3 + + + align:start position:0% +derivative d by DX of 3 +x^2 is equal to 3 * the derivative of d + + align:start position:0% +x^2 is equal to 3 * the derivative of d + + + align:start position:0% +x^2 is equal to 3 * the derivative of d +by DX of x squared now this is good + + align:start position:0% +by DX of x squared now this is good + + + align:start position:0% +by DX of x squared now this is good +because we we already have a rule for + + align:start position:0% +because we we already have a rule for + + + align:start position:0% +because we we already have a rule for +computing derivatives of powers of X um + + align:start position:0% +computing derivatives of powers of X um + + + align:start position:0% +computing derivatives of powers of X um +so this says we don't need a special + + align:start position:0% +so this says we don't need a special + + + align:start position:0% +so this says we don't need a special +rule for computing multiples of powers + + align:start position:0% +rule for computing multiples of powers + + + align:start position:0% +rule for computing multiples of powers +of of x s we don't need to go back to + + align:start position:0% +of of x s we don't need to go back to + + + align:start position:0% +of of x s we don't need to go back to +the Limit definition to compute the + + align:start position:0% +the Limit definition to compute the + + + align:start position:0% +the Limit definition to compute the +derivative of 3x^2 we can just use the + + align:start position:0% +derivative of 3x^2 we can just use the + + + align:start position:0% +derivative of 3x^2 we can just use the +fact that we know the derivative of x + + align:start position:0% +fact that we know the derivative of x + + + align:start position:0% +fact that we know the derivative of x +squ in order to compute the derivative + + align:start position:0% +squ in order to compute the derivative + + + align:start position:0% +squ in order to compute the derivative +of 3x^2 so in this case that would work + + align:start position:0% +of 3x^2 so in this case that would work + + + align:start position:0% +of 3x^2 so in this case that would work +out to to + + align:start position:0% +out to to + + + align:start position:0% +out to to +6X in in this case so it so it + + align:start position:0% +6X in in this case so it so it + + + align:start position:0% +6X in in this case so it so it +simplifies the number of different + + align:start position:0% +simplifies the number of different + + + align:start position:0% +simplifies the number of different +computations we have to do it reduces + + align:start position:0% +computations we have to do it reduces + + + align:start position:0% +computations we have to do it reduces +the number of times we need to go back + + align:start position:0% +the number of times we need to go back + + + align:start position:0% +the number of times we need to go back +to the Limit definition um so so that's + + align:start position:0% +to the Limit definition um so so that's + + + align:start position:0% +to the Limit definition um so so that's +the use of the rule um let's let's + + align:start position:0% +the use of the rule um let's let's + + + align:start position:0% +the use of the rule um let's let's +quickly talk about its proof so the idea + + align:start position:0% +quickly talk about its proof so the idea + + + align:start position:0% +quickly talk about its proof so the idea +behind the proof is you you have these + + align:start position:0% +behind the proof is you you have these + + + align:start position:0% +behind the proof is you you have these +two derivatives and you want to show + + align:start position:0% +two derivatives and you want to show + + + align:start position:0% +two derivatives and you want to show +that they're equal well anytime you have + + align:start position:0% +that they're equal well anytime you have + + + align:start position:0% +that they're equal well anytime you have +a derivative what it really means means + + align:start position:0% +a derivative what it really means means + + + align:start position:0% +a derivative what it really means means +is it's the value of some limmit of some + + align:start position:0% +is it's the value of some limmit of some + + + align:start position:0% +is it's the value of some limmit of some +difference quotient so in this case um + + align:start position:0% +difference quotient so in this case um + + + align:start position:0% +difference quotient so in this case um +we have the that the + + align:start position:0% +we have the that the + + + align:start position:0% +we have the that the +derivative d by DX of + + align:start position:0% +derivative d by DX of + + + align:start position:0% +derivative d by DX of +C time F ofx by + + align:start position:0% +C time F ofx by + + + align:start position:0% +C time F ofx by +definition is the limit of a difference + + align:start position:0% +definition is the limit of a difference + + + align:start position:0% +definition is the limit of a difference +quotient as Delta X goes to zero of so + + align:start position:0% +quotient as Delta X goes to zero of so + + + align:start position:0% +quotient as Delta X goes to zero of so +we take the function C * FX and we plug + + align:start position:0% +we take the function C * FX and we plug + + + align:start position:0% +we take the function C * FX and we plug +in X Plus Delta X and we plug in X and + + align:start position:0% +in X Plus Delta X and we plug in X and + + + align:start position:0% +in X Plus Delta X and we plug in X and +we take the difference and we divide by + + align:start position:0% +we take the difference and we divide by + + + align:start position:0% +we take the difference and we divide by +Delta X so that's C * f of x + Delta xus + + align:start position:0% +Delta X so that's C * f of x + Delta xus + + + align:start position:0% +Delta X so that's C * f of x + Delta xus +C * F + + align:start position:0% + + + + align:start position:0% + +ofx divided by Delta X now you'll notice + + align:start position:0% +ofx divided by Delta X now you'll notice + + + align:start position:0% +ofx divided by Delta X now you'll notice +that that here both terms in the + + align:start position:0% +that that here both terms in the + + + align:start position:0% +that that here both terms in the +numerator have this constant uh factor C + + align:start position:0% +numerator have this constant uh factor C + + + align:start position:0% +numerator have this constant uh factor C +in them so we can we can factor that out + + align:start position:0% +in them so we can we can factor that out + + + align:start position:0% +in them so we can we can factor that out +and I'll just pull it out in front of + + align:start position:0% +and I'll just pull it out in front of + + + align:start position:0% +and I'll just pull it out in front of +this whole fraction so this is the + + align:start position:0% +this whole fraction so this is the + + + align:start position:0% +this whole fraction so this is the +limit as Delta X goes to zero of C e + + align:start position:0% +limit as Delta X goes to zero of C e + + + align:start position:0% +limit as Delta X goes to zero of C e +* the + + align:start position:0% +* the + + + align:start position:0% +* the +ratio F ofx + Delta + + align:start position:0% +ratio F ofx + Delta + + + align:start position:0% +ratio F ofx + Delta +xus F ofx whole + + align:start position:0% +xus F ofx whole + + + align:start position:0% +xus F ofx whole +quantity over Delta X now C is just some + + align:start position:0% +quantity over Delta X now C is just some + + + align:start position:0% +quantity over Delta X now C is just some +constant this this part depends on Delta + + align:start position:0% +constant this this part depends on Delta + + + align:start position:0% +constant this this part depends on Delta +X and and on X but but on Delta X so as + + align:start position:0% +X and and on X but but on Delta X so as + + + align:start position:0% +X and and on X but but on Delta X so as +Delta X goes to zero this changes while + + align:start position:0% +Delta X goes to zero this changes while + + + align:start position:0% +Delta X goes to zero this changes while +this this stays the same um what that + + align:start position:0% +this this stays the same um what that + + + align:start position:0% +this this stays the same um what that +means is what so as Delta X goes to zero + + align:start position:0% +means is what so as Delta X goes to zero + + + align:start position:0% +means is what so as Delta X goes to zero +this gets closer closer to something the + + align:start position:0% +this gets closer closer to something the + + + align:start position:0% +this gets closer closer to something the +value of its limit um and C you're just + + align:start position:0% +value of its limit um and C you're just + + + align:start position:0% +value of its limit um and C you're just +multiplying it in so C time the limit of + + align:start position:0% +multiplying it in so C time the limit of + + + align:start position:0% +multiplying it in so C time the limit of +c times this is equal to c times the the + + align:start position:0% +c times this is equal to c times the the + + + align:start position:0% +c times this is equal to c times the the +whatever the limit of this is if this is + + align:start position:0% +whatever the limit of this is if this is + + + align:start position:0% +whatever the limit of this is if this is +getting closer and closer to some value + + align:start position:0% +getting closer and closer to some value + + + align:start position:0% +getting closer and closer to some value +c times it is getting closer and closer + + align:start position:0% +c times it is getting closer and closer + + + align:start position:0% +c times it is getting closer and closer +to c times that value so this is equal + + align:start position:0% +to c times that value so this is equal + + + align:start position:0% +to c times that value so this is equal +to + + align:start position:0% +to + + + align:start position:0% +to +C in other words we can we can we can + + align:start position:0% +C in other words we can we can we can + + + align:start position:0% +C in other words we can we can we can +pull constant multiples outside of + + align:start position:0% +pull constant multiples outside of + + + align:start position:0% +pull constant multiples outside of +limits so this limit as Delta x c times + + align:start position:0% +limits so this limit as Delta x c times + + + align:start position:0% +limits so this limit as Delta x c times +the limit as Delta X goes to zero of f + + align:start position:0% +the limit as Delta X goes to zero of f + + + align:start position:0% +the limit as Delta X goes to zero of f +ofx + Delta + + align:start position:0% +ofx + Delta + + + align:start position:0% +ofx + Delta +xus + + align:start position:0% + + + + align:start position:0% + +FX over Delta X and this limit here is + + align:start position:0% +FX over Delta X and this limit here is + + + align:start position:0% +FX over Delta X and this limit here is +just the definition of the derivative of + + align:start position:0% +just the definition of the derivative of + + + align:start position:0% +just the definition of the derivative of +f ofx so this is equal to by definition + + align:start position:0% +f ofx so this is equal to by definition + + + align:start position:0% +f ofx so this is equal to by definition +C + + align:start position:0% +C + + + align:start position:0% +C +* d by + + align:start position:0% +* d by + + + align:start position:0% +* d by +DX of f ofx so we started with the + + align:start position:0% +DX of f ofx so we started with the + + + align:start position:0% +DX of f ofx so we started with the +derivative of C * F ofx and we + + align:start position:0% +derivative of C * F ofx and we + + + align:start position:0% +derivative of C * F ofx and we +showed that this is equal to C time the + + align:start position:0% +showed that this is equal to C time the + + + align:start position:0% +showed that this is equal to C time the +derivative of f ofx so that's exactly + + align:start position:0% +derivative of f ofx so that's exactly + + + align:start position:0% +derivative of f ofx so that's exactly +what we wanted so that proves the + + align:start position:0% +what we wanted so that proves the + + + align:start position:0% +what we wanted so that proves the +constant multiple rule so so we now have + + align:start position:0% +constant multiple rule so so we now have + + + align:start position:0% +constant multiple rule so so we now have +we've now proved the constant multiple + + align:start position:0% +we've now proved the constant multiple + + + align:start position:0% +we've now proved the constant multiple +rule let me talk a little bit about some + + align:start position:0% +rule let me talk a little bit about some + + + align:start position:0% +rule let me talk a little bit about some +geometric intuition for why this works + + align:start position:0% +geometric intuition for why this works + + + align:start position:0% +geometric intuition for why this works +so I've got here well so uh you know you + + align:start position:0% +so I've got here well so uh you know you + + + align:start position:0% +so I've got here well so uh you know you +know let's take C equals 2 just for + + align:start position:0% +know let's take C equals 2 just for + + + align:start position:0% +know let's take C equals 2 just for +Simplicity so here I have a graph y + + align:start position:0% +Simplicity so here I have a graph y + + + align:start position:0% +Simplicity so here I have a graph y +equals F ofx and I have also drawn the + + align:start position:0% +equals F ofx and I have also drawn the + + + align:start position:0% +equals F ofx and I have also drawn the +graph yal 2 FX so the relationship + + align:start position:0% +graph yal 2 FX so the relationship + + + align:start position:0% +graph yal 2 FX so the relationship +between these graphs is that yal 2 f ofx + + align:start position:0% +between these graphs is that yal 2 f ofx + + + align:start position:0% +between these graphs is that yal 2 f ofx +is what you get when you stretch the + + align:start position:0% +is what you get when you stretch the + + + align:start position:0% +is what you get when you stretch the +graph for yal f ofx vertically by a + + align:start position:0% +graph for yal f ofx vertically by a + + + align:start position:0% +graph for yal f ofx vertically by a +factor of two so uh you know if if it + + align:start position:0% +factor of two so uh you know if if it + + + align:start position:0% +factor of two so uh you know if if it +passed through zero before it still + + align:start position:0% +passed through zero before it still + + + align:start position:0% +passed through zero before it still +passes through zero but everywhere else + + align:start position:0% +passes through zero but everywhere else + + + align:start position:0% +passes through zero but everywhere else +if it was above zero it's now twice as + + align:start position:0% +if it was above zero it's now twice as + + + align:start position:0% +if it was above zero it's now twice as +high if it was below zero it's now twice + + align:start position:0% +high if it was below zero it's now twice + + + align:start position:0% +high if it was below zero it's now twice +as low um so if you think about what the + + align:start position:0% +as low um so if you think about what the + + + align:start position:0% +as low um so if you think about what the +definition of what derivative means uh + + align:start position:0% +definition of what derivative means uh + + + align:start position:0% +definition of what derivative means uh +in terms of this graph geometrically + + align:start position:0% +in terms of this graph geometrically + + + align:start position:0% +in terms of this graph geometrically +it's telling you the limit of uh sorry + + align:start position:0% +it's telling you the limit of uh sorry + + + align:start position:0% +it's telling you the limit of uh sorry +the slope of a tangent line or in other + + align:start position:0% +the slope of a tangent line or in other + + + align:start position:0% +the slope of a tangent line or in other +words the limit of the slopes of secant + + align:start position:0% +words the limit of the slopes of secant + + + align:start position:0% +words the limit of the slopes of secant +lines so if you look at these two curves + + align:start position:0% +lines so if you look at these two curves + + + align:start position:0% +lines so if you look at these two curves +say so let's pick a couple values of X + + align:start position:0% +say so let's pick a couple values of X + + + align:start position:0% +say so let's pick a couple values of X +say and then maybe X Plus Delta + + align:start position:0% +say and then maybe X Plus Delta + + + align:start position:0% +say and then maybe X Plus Delta +X so if you look at the secant + + align:start position:0% + + + + align:start position:0% + +lines for these two curves through those + + align:start position:0% +lines for these two curves through those + + + align:start position:0% +lines for these two curves through those +points what you see see is that these + + align:start position:0% +points what you see see is that these + + + align:start position:0% +points what you see see is that these +two lines they have the same you know so + + align:start position:0% +two lines they have the same you know so + + + align:start position:0% +two lines they have the same you know so +so the slope of a of a line is its rise + + align:start position:0% +so the slope of a of a line is its rise + + + align:start position:0% +so the slope of a of a line is its rise +over its run so they have the same run + + align:start position:0% +over its run so they have the same run + + + align:start position:0% +over its run so they have the same run +that we're talking about the same little + + align:start position:0% +that we're talking about the same little + + + align:start position:0% +that we're talking about the same little +interval here but this in the in the + + align:start position:0% +interval here but this in the in the + + + align:start position:0% +interval here but this in the in the +function that's scaled up in the y + + align:start position:0% +function that's scaled up in the y + + + align:start position:0% +function that's scaled up in the y +equals 2 F ofx curve we have that the r + + align:start position:0% +equals 2 F ofx curve we have that the r + + + align:start position:0% +equals 2 F ofx curve we have that the r +everything's been stretched upwards by a + + align:start position:0% +everything's been stretched upwards by a + + + align:start position:0% +everything's been stretched upwards by a +factor of two so the the the rise here + + align:start position:0% +factor of two so the the the rise here + + + align:start position:0% +factor of two so the the the rise here +is exactly double the rise here so the + + align:start position:0% +is exactly double the rise here so the + + + align:start position:0% +is exactly double the rise here so the +slope of this secant line is exactly + + align:start position:0% +slope of this secant line is exactly + + + align:start position:0% +slope of this secant line is exactly +double the slope of this cant line and + + align:start position:0% +double the slope of this cant line and + + + align:start position:0% +double the slope of this cant line and +similarly the tangent line just a a + + align:start position:0% +similarly the tangent line just a a + + + align:start position:0% +similarly the tangent line just a a +limit of secant lines has been stretched + + align:start position:0% +limit of secant lines has been stretched + + + align:start position:0% +limit of secant lines has been stretched +by that same factor of two so the slope + + align:start position:0% +by that same factor of two so the slope + + + align:start position:0% +by that same factor of two so the slope +of the tangent line is exactly twice the + + align:start position:0% +of the tangent line is exactly twice the + + + align:start position:0% +of the tangent line is exactly twice the +slope of the C of of the tangent line + + align:start position:0% +slope of the C of of the tangent line + + + align:start position:0% +slope of the C of of the tangent line +for the for the other function so the + + align:start position:0% +for the for the other function so the + + + align:start position:0% +for the for the other function so the +tangent line here is exactly twice as + + align:start position:0% +tangent line here is exactly twice as + + + align:start position:0% +tangent line here is exactly twice as +steep as the tangent line here or in + + align:start position:0% +steep as the tangent line here or in + + + align:start position:0% +steep as the tangent line here or in +other words the derivative of this + + align:start position:0% +other words the derivative of this + + + align:start position:0% +other words the derivative of this +function is exactly twice the derivative + + align:start position:0% +function is exactly twice the derivative + + + align:start position:0% +function is exactly twice the derivative +of that function so that that's just + + align:start position:0% +of that function so that that's just + + + align:start position:0% +of that function so that that's just +that's the just a geometric statement of + + align:start position:0% +that's the just a geometric statement of + + + align:start position:0% +that's the just a geometric statement of +this very same uh constant multiple rule + + align:start position:0% +this very same uh constant multiple rule + + + align:start position:0% +this very same uh constant multiple rule +that we stated Al algebraically at the + + align:start position:0% +that we stated Al algebraically at the + + + align:start position:0% +that we stated Al algebraically at the +at the beginning and that we just proved + + align:start position:0% +at the beginning and that we just proved + + + align:start position:0% +at the beginning and that we just proved +so that's that \ No newline at end of file diff --git a/FNeL18KsWPc.txt b/FNeL18KsWPc.txt new file mode 100644 index 0000000000000000000000000000000000000000..4e795b4dc1bf7796eb3a796b0387b76c184f0140 --- /dev/null +++ b/FNeL18KsWPc.txt @@ -0,0 +1,2558 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high-quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Continuing +in the theme + +of sorting in general, but +in particular, binary search + +trees, which are a +kind of way of doing + +dynamic sorting, +if you will, where + +the elements are +coming and going. + +And at all times, you want +to know the sorted order + +of your elements by storing them +in a nice binary search tree. + +Remember, in general, a +binary search tree is a tree. + +It's binary, and it has +the search property. + +Those three things. + +This is a rooted binary tree. + +It has a root. + +It's binary, so there's a +left child and a right child. + +Some nodes lack a +right or left child. + +Some nodes lack both. + +Every node has a key. + +This is the search part. + +You store key in every node, +and you have this BST property, + +or also called the +search property, + +that every node-- if you +have a node the stores key x, + +everybody in the left subtree +stores a key that's less than + +or equal to x, and everyone +that's in the right subtree + +stores a key that's +greater than or equal to x. + +So not just the left +and right children, + +but every descendant way +down there is smaller than x. + +Every descendent way down +there is greater than x. + +So when you have a binary +search tree like this, + +if you want to know +the sorted order, + +you do what's called +an in-order traversal. + +You look at a node. + +You recursively +visit the left child. + +Then you print out the root. + +Then you recursively +visit the right child. + +So in this case, we'd +go left, left, print 11. + +Print 20. + +Go right. + +Go left. + +Print 26. + +Print 29. + +Go up. + +Print 41. + +Go right. + +Print 50. + +Print 65. + +Then check that's +in sorted order. + +If you're not familiar +with in-order traversal, + +look at the textbook. + +It's a very simple operation. + +I'm not going to talk +about it more here, + +except we're going to use it. + +All right, we'll get to the +topic of today's lecture + +in a moment, which is balance. + +What we saw in last +lecture and recitation + +is that these +basic binary search + +trees, where when you insert +a node you just walk down + +the tree to find where that item +fits-- like if you're trying + +to insert 30, you go left here, +go right here, go right here, + +and say, oh 30 fits here. + +Let's put 30 there. + +If you keep doing that, +you can do insert. + +You can do delete. + +You can do these +kinds of searches, + +which we saw, finding +the next larger element + +or finding the next +smaller element, also known + +as successor and predecessor. + +These are actually the typical +names for those operations. + +You can solve them +in order h time. + +Anyone remember what h was? + +The height. + +Yeah, good. + +The height of the tree. + +So h is the height of the BST. + +What is the height of the tree? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Sorry? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Log n? + +Log n would be great, +but not always. + +So this is the issue +of being balance. + +So in an ideal +world, your tree's + +going to look +something like this. + +I've drawn this picture probably +the most in my academic career. + +This is a nice, perfectly +balanced binary search tree. + +The height is log n. + +This would be the balance case. + +I mean, roughly log n. + +Let's just put theta +to be approximate. + +But as we saw at the +end of last class, + +you can have a very unbalanced +tree, which is just a path. + +And there the height is n. + +What's the definition of height? + +That's actually what +I was looking for. + +Should be 6.042 material. + +Yeah? + +AUDIENCE: Is it the +length of the longest path + +always going down? + +PROFESSOR: Yeah, length of the +longest path always going down. + +So length of the longest path +from the root to some leaf. + +That's right. + +OK, so this is-- + +I highlight this +because we're going + +to be working a lot +with height today. + +All that's happening here, all +of the paths are length log n. + +Here, there is a +path of length n. + +Some of them are shorter, +but in fact, the average path + +is n over 2. + +It's really bad. + +So this is very unbalanced. + +I'll put "very." + +It's not a very formal +term, but that's + +like the worst case for BSTs. + +This is good. + +This does have a +formal definition. + +We call a tree balanced if +the height is order log n. + +So you're storing n keys. + +If your height is +always order log n, + +we get a constant factor here. + +Here, it's basically exactly +log n, 1 times log n. + +It's always going to +be at least log n, + +because if you're storing +n things in a binary tree, + +you need to have +height at least log n. + +So in fact, it will be theta +log n if your tree is balanced. + +And today's goal is +to always maintain + +that your trees are balanced. + +And we're going to do +that using the structure + +called AVL trees, which +I'll define in a moment. + +They're the original +way people found + +to keep trees balanced +back in the '60s, + +but they're still +kind of the simplest. + +There are lots of ways +to keep a tree balanced, + +so I'll mention some other +balance trees later on. + +In particular, your textbook +covers two other ways to do it. + +It does not cover AVL +trees, so pay attention. + +One more thing I +wanted to define. + +We talked about the +height of the tree, + +but I'd also like to talk about +the height of a node in a tree. + +Can anyone define this for me? + +Yeah? + +AUDIENCE: It's the level +that the node is at. + +PROFESSOR: The level +that the node is at. + +That is roughly right. + +I mean, that is right. + +It's all about, what +is the level of a node? + +AUDIENCE: Like how many +levels of children it has. + +PROFESSOR: How many +levels of children it has. + +That's basically right, yeah. + +AUDIENCE: The distance +from it to the root. + +PROFESSOR: Distance +from it to the root. + +That would be the depth. + +So depth is counting from above. + +Height is-- + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yes, longest path +from that node to the leaf. + +Note that's why I wrote +this definition actually, + +to give you a hint. + +Here I should probably +say down to be precise. + +You're not allowed to +go up in these paths. + +[INAUDIBLE] + +All right. + +Sorry. + +I've got to learn how to throw. + +All right. + +So for example, over here I'm +going to write depths in red. + +If you're taking notes it's OK. + +Don't worry. + +So length off the longest +path from it down to a leaf. + +Well, this is a leaf, +so its height is 0. + +OK. + +Yeah, I'll just +leave it at that. + +It takes 0 steps to get +from a leaf to a leaf. + +This guy's not a leaf. + +It has a child, but it has a +path of length one to a leaf. + +So it's one. + +This guy has a choice. + +You could go left and you +get a path of length 1, + +or you could go right and +get a path of length 2. + +We take the max, so +this guy has height 2. + +This node has height 1. + +This node has height 3. + +How do you compute +the height of a node? + +Anyone? + +Yeah. + +AUDIENCE: Max of the height +of the children plus 1. + +PROFESSOR: Right. + +You take the max of the +height of the children. + +Here, 2 and 1. + +Max is 2. + +Add 1. + +You get 3. + +So it's going to always +be-- this is just a formula. + +The height of the +left child maxed + +with the height of the +right child plus 1. + +This is obviously +useful for computing. + +And in particular, in +lecture and recitation + +last time, we saw +how to maintain + +the size of every tree using +data structure augmentation. + +Data structure augmentation. + +And then we started with a +regular vanilla binary search + +tree, and then we +maintained-- every time + +we did an operation +on the tree, we also + +updated the size of +the subtree rooted + +at that node, the size field. + +Here, I want to +store a height field, + +and because I have this nice +local rule that tells me + +how to compute the height +of a node using just + +local information-- the height +of its left child, the height + +of its right child. + +Do a constant +amount of work here. + +There's a general theorem. + +Whenever you have a +nice local formula + +like this for updating +your information in terms + +of your children, +then you can maintain + +it using constant overhead. + +So we can store the height +of every node for free. + +Why do I care? + +Because AVL trees are going to +use the heights of the nodes. + +Our goal is to keep +the heights small. + +We don't want this. + +We want this. + +So a natural thing to +do is store the heights. + +When they get too big, fix it. + +So that's what +we're going to do. + +Maybe one more thing to mention +over here for convenience. + +Leaves, for example, have +children that are-- I mean, + +they have null pointers to +their left and right children. + +You could draw them +explicitly like this. + +Also some nodes just +lack a single child. + +I'm going to define the +depths of these things + +to be negative 1. + +This will be +convenient later on. + +Why negative 1? + +Because then this formula works. + +You can just think about it. + +Like leaves, for example, +have two children, + +which are negative 1. + +You take the max. + +You add 1. + +You get 0. + +So that just makes +things work out. + +We don't normally draw +these in the pictures, + +but it's convenient that I don't +have to do special cases when + +the left child doesn't exist and +the right child doesn't exist. + +You could either +do special cases + +or you could make +this definition. + +Up to you. + +OK. + +AVL trees. + +So the idea with an AVL +tree is the following. + +We'd like to keep the +height order log n. + +It's a little harder to think +about keeping the height order + +log n than it is to think +about keeping the tree balance, + +meaning the left and right +sides are more or less equal. + +In this case, we're +going to think about them + +as being more or +less equal in height. + +You could also think +about them being + +more or less equal +in subtree size. + +That would also work. + +It's a different +balanced search tree. + +Height is kind of the +easiest thing to work with. + +So if we have a node, +it has a left subtree. + +It has a right subtree, +which we traditionally + +draw as triangles. + +This subtree has a height. + +We'll call it HL for left. + +By the height of the subtree, +I mean the height of its root. + +And the right subtree +has some height, r. + +I've drawn them as the +same, but in general they + +might be different. + +And what we would like +is that h sub l and h + +sub r are more or less the same. + +They differ by at +most an additive 1. + +So if I look at h sub l minus +h sub r in absolute value, + +this is at most +1, for every node. + +So I have some node x. + +For every node x, I want +the left and right subtrees + +to be almost balanced. + +Now, I could say +differ by at most 0, + +that the left and right have +exactly the same heights. + +That's difficult, +because that really + +forces you to have +exactly the perfect tree. + +And in fact, it's not even +possible for odd n or even n + +or something. + +Because at the very +end you're going + +to have one missing child, and +then you're unbalanced there. + +So 0's just not +possible to maintain, + +but 1 is almost as +good, hopefully. + +We're going to prove +that in a second. + +And it turns out to be easy +to maintain in log n time. + +So let's prove some stuff. + +So first claim is that +AVL trees are balanced. + +Balanced, remember, means +that the height of them + +is always order log n. + +So we're just going to assume +for now that we can somehow + +achieve this property. + +We want to prove that it +implies that the height is + +at most some +constant times log n. + +We know it's at +least log n, but also + +like it to be not much bigger. + +So what do you think +is the worst case? + +Say I have n nodes. + +How could I make the +tree as high as possible? + +Or conversely, if I have +a particular height, + +how could I make it have +as few nodes as possible? + +That'd be like the +sparsest, the least balanced + +situation for AVL trees. + +Yeah? + +AUDIENCE: You could have +one node on the last level. + +PROFESSOR: One node on the last +level, yeah, in particular. + +Little more. + +What do the other +levels look like? + +That is correct, but I want +to know the whole tree. + +It's hard to explain +the tree, but you + +can explain the core +property of the tree. + +Yeah? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: For every +node, let's make + +the right side have a height of +one larger than the left side. + +I think that's worth a cushion. + +See if I can throw better. + +Good catch. + +Better than hitting your eye. + +So I'm going to not +prove this formally, + +but I think if you stare +at this long enough it's + +pretty obvious. + +Worst case is when-- there +are multiple worst cases, + +because right and +left are symmetric. + +We don't really care. + +But let's say that +the right subtree + +has height one more than +the left for every node. + +OK, this is a little +tricky to draw. + +Not even sure I want +to try to draw it. + +But you basically +draw it recursively. + +So, OK, somehow I've +figured out this + +where the height +difference here is 1. + +Then I take two copies of it. + +It's like a fractal. + +You should know all +about fractals by now. + +Problem set two. + +And then you just-- well, +that's not quite right. + +In fact, I need to somehow +make this one a little + +bit taller and then +glue these together. + +Little tricky. + +Let's not even try +to draw the tree. + +Let's just imagine +this is possible. + +It is possible. + +And instead, I'm going +to use mathematics + +to understand how +high that tree is. + +Or actually, it's +a little easier + +to think about-- let +me get this right. + +It's so easy that I +have to look at my notes + +to remember what to write. + +Really, no problem. + +All right, so I'm +going to define n sub h + +is the minimum number +of nodes that's + +possible in an AVL +tree of height h. + +This is sort of the inverse +of what we care about, + +but if we can solve the +inverse, we can solve the thing. + +What we really care about +is, for n nodes, how large + +can the height be? + +We want to prove +that's order log n. + +But it'll be a lot easier to +think about the reverse, which + +is, if I fix the height to +be h, what's the fewest nodes + +that I can pack in? + +Because for the very unbalanced +tree, I have a height of n, + +and I only need to put n nodes. + +That would be really bad. + +What I prefer is a situation +like this, where with height h, + +I have to put in +2 to the h nodes. + +That would be perfect balance. + +Any constant to the h will do. + +So when you take the +inverse, you get a log. + +OK, we'll get to +that in a moment. + +How should we analyze n sub h? + +I hear something. + +Yeah? + +AUDIENCE: [INAUDIBLE] 2 to +the h minus 1 [INAUDIBLE]. + +PROFESSOR: Maybe, but I don't +think that will quite work out. + +Any-- yeah? + +AUDIENCE: So you have only +1 node in the last level, + +so it would be 1/2 +to the h plus 1. + +PROFESSOR: That turns out +to be approximately correct, + +but I don't know where you +got 1/2 to the h plus 1. + +It's not exactly correct. + +I'll tell you that, so that +your analysis isn't right. + +It's a lot easier. + +You guys are worried +about the last level + +and actually what the tree looks +like, but in fact, all you need + +is this. + +All you need is love, yeah. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: No, it's not a half. + +It's a different constant. + +Yeah? + +AUDIENCE: Start with base cases +and write a recursive formula. + +PROFESSOR: Ah, +recursive formula. + +Good. + +You said start with base cases. + +I always forget that part, so +it's good that you remember. + +You should start +with the base case, + +but I'm not going to +worry about the base case + +because it won't matter. + +Because I know the base case +is always going to be n order 1 + +is order 1. + +So for algorithms, +that's usually all + +you need for base case, but it's +good that you think about it. + +What I was looking for +is recursive formula, + +aka, recurrence. + +So can someone tell me-- +maybe even you-- could tell me + +a recurrence for n sub h, +in terms of n sub smaller h? + +Yeah? + +AUDIENCE: 1 plus [INAUDIBLE]. + +PROFESSOR: 1 plus +n sub h minus 1. + +Not quite. + +Yeah? + +AUDIENCE: N sub h minus +1 plus n sub h minus 2. + +PROFESSOR: N plus-- do +you want the 1 plus? + +AUDIENCE: I don't think so. + +PROFESSOR: You do. + +It's a collaboration. + +To combine your +two answers, this + +should be the correct formula. + +Let me double check. + +Yes, whew. + +Good. + +OK, why? + +Because the one thing we know is +that our tree looks like this. + +The total height here is h. + +That's what we're +trying to figure out. + +How many nodes are in +this tree of height h? + +Well, the height is the +max of the two directions. + +So that means that the +larger has height h minus 1, + +because the longest +path to a leaf + +is going to be down this way. + +What's the height of this? + +Well, it's one less +than the height of this. + +So it's going to be h minus 2. + +This is where the n sub h minus +1 plus n sub h minus 2 come in. + +But there's also this node. + +It doesn't actually make a big +difference in this recurrence. + +This is the exponential part. + +This is like itty bitty thing. + +But it matters for the +base case is pretty much + +where it matters. + +Back to your base case. + +There's one guy here, plus +all the nodes on the left, + +plus all the nodes on the right. + +And for whatever +reason, I put the left + +over here and the +right over here. + +And of course, you could +reverse this picture. + +It doesn't really matter. + +You get the same formula. + +That's the point. + +So this is the recurrence. + +Now we need to solve it. + +What we would like is +for it to be exponential, + +because that means there's a +lot of nodes in a height h AVL + +tree. + +So any suggestions on +how we could figure out + +this recurrence? + +Does it look like anything +you've seen before? + +AUDIENCE: Fibonacci. + +PROFESSOR: Fibonacci. + +It's almost Fibonacci. + +If I hid this plus 1, +which you wanted to do, + +then it would be +exactly Fibonacci. + +Well, that's actually good, +because in particular, n sub h + +is bigger than Fibonacci. + +If you add one at +every single level, + +the certainly you +get something bigger + +than the base +Fibonacci sequence. + +Now, hopefully you know +Fibonacci is exponential. + +I have an exact formula. + +If you take the golden ratio to +the power h, divide by root 5, + +and round to the +nearest integer, + +you get exactly the +Fibonacci number. + +Crazy stuff. + +We don't need to +know why that's true. + +Just take it as fact. + +And conveniently phi +is bigger than 1. + +You don't need to +remember what phi + +is, except it is bigger than 1. + +And so this is an +exponential bound. + +This is good news. + +So I'll tell you +it's about 1.618. + +And so we get is that-- +if we invert this, + +this says n sub h is bigger +than some phi to the h. + +This is our n, basically. + +What we really +want to know is how + +h relates to n, which is +just inverting this formula. + +So we have, on the +other hand, the phi + +to the h divided by +root 5 is less than n. + +So I got a log base +phi on both sides. + +Seems like a good thing to do. + +This is actually quite annoying. + +I've got h minus a +tiny little thing. + +It's less than +log base phi of n. + +And I will tell you that is +about 1.440 times log base 2 + +of n, because after all, +log base 2 is what computer + +scientists care about. + +So just to put it +into perspective. + +We want it to be +theta log base 2 of n. + +And here's the bound. + +The height is always less +than 1.44 times log n. + +All we care about +is some constant, + +but this is a pretty +good constant. + +We'd like one. + +There are binary search tress +that achieve 1, plus very, + +very tiny thing, arbitrarily +tiny, but this is pretty good. + +Now, if you don't know +Fibonacci numbers, + +I pull a rabbit out of a hat +and I've got this phi to the h. + +It's kind of magical. + +There's a much easier way +to analyze this recurrence. + +I'll just tell you because +it's good to know but not + +super critical. + +So we have this +recurrence, n sub h. + +This is the computer scientist +way to solve the recurrence. + +We don't care about +the constants. + +This is the theoretical +computer scientist + +way to solve this recurrence. + +We don't care about constants. + +And so we say, aw, this is hard. + +I've got n sub h minus +1 and n sub h minus 2. + +So asymmetric. + +Let's symmetrify. + +Could I make them +both n sub h minus 1. + +Or could I make them +both n sub h minus 2? + +Suggestions? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Minus +2 is the right way + +to go because I want to know n +sub h is greater than something + +in order to get a +less than down here. + +By the way, I use that +log is monatomic here, + +but it is, so we're good. + +So this is going to +be greater than 1 + +plus 2 times n sub h minus 2. + +Because if I have +a larger height + +I'm going to have more nodes. + +That's an easy +proof by induction. + +So I can combine +these into one term. + +It's simpler. + +I can get rid of this 1 because +that only makes things bigger. + +So I just have this. + +OK, now I need a +base case, but this + +looks like 2 the something. + +What's the something? + +H over 2. + +So I'll just write theta +to avoid the base case. + +2 to the h over 2. + +Every two steps of h, I +get another factor of 2. + +So when you invert +and do the log, + +this means that h is also +less than log base 2 of n. + +Log base 2 because of that. + +Factor 2 out here +because of that factor 2 + +when you take the log. + +And so the real answer is 1.44. + +This is the correct-- +this is the worst case. + +But it's really easy to prove +that it's, at most, 2 log n. + +So keep this in +mind in case we ask + +you to analyze +variance of AVL trees, + +like in problem set three. + +This is the easy way +to do it and just get + +some constant times log n. + +Clear? + +All right, so that's AVL +trees, why they're balanced. + +And so if we can +achieve this property, + +that the left and right subtrees +have about the same height, + +we'll be done. + +So how the heck do we +maintain that property? + +Let's go over here. + +Mobius trees are +supposed to support + +a whole bunch of operations, +but in particular, insert + +and delete. + +I'm just going to worry +about insert today. + +Delete is almost identical. + +And it's in the code that +corresponds to this lecture, + +so you can take a look at it. + +Very, very similar. + +Let's start with insert. + +Well, it's pretty +straightforward. + +Our algorithm is as follows. + +We do the simple BST insertion, +which we already saw, + +which is you walk down the tree +to find where that key fits. + +You search for that key. + +And wherever it isn't, +you insert a node there, + +insert a new leaf, +and add it in. + +Now, this will not +preserve the AVL property. + +So the second step is +fix the AVL property. + +And there's a nice concise +description of AVL insertion. + +Of course, how do you do step +two is the interesting part. + +All right, maybe let's +start with an example. + +That could be fun. + +Hey, look, here's an example. + +And to match the +notes, I'm going + +to do insert 23 as +a first example. + +OK, I'm also going to annotate +this tree a little bit. + +So I said we store +the heights, but what + +I care about is which height is +larger, the left or the right. + +In fact, you could +just store that, + +just store whether +it's plus 1, minus 1, + +or 0, the difference between +left and right sides. + +So I'm going to draw that +with a little icon, which + +is a left arrow, a +descending left arrow if this + +is the bigger side. + +And this is a right arrow. + +This is even. + +Left and right are the same. + +Here, the left is heavier, +or higher, I guess. + +Here it's even. + +Here it's left. + +This is AVL, because +it's only one + +heavier wherever +I have an arrow. + +OK, now I insert 23. + +23 belongs-- it's less than 41, +greater than 20, less than 29, + +less than 26. + +So it belongs here. + +Here's 23, a brand-new node. + +OK, now all the heights change. + +And it's annoying to draw +what the heights are, + +but I'll do it. + +This one changes to 1. + +This is 0. + +This changes to 2. + +This changes to 3. + +This changes to 4. + +Anyway, never mind +what the heights are. + +What's bad is, well, +this guy's even. + +This guy's left heavy. + +This guy's now +doubly left heavy. + +Bad news. + +OK, let's not worry +about above that. + +Let's just start. + +The algorithm is going +to walk up the tree + +and say, oh, when do +I get something bad? + +So now I have 23, +26, 29 in a path. + +I'd like to fix it. + +Hmm, how to fix it? + +I don't think we know how to +fix it, so I will tell you how. + +Actually, I wasn't +here last week. + +So did we cover rotations? + +AUDIENCE: No. + +PROFESSOR: OK, good. + +Then you don't know. + +Let me tell you about rotations. + +Super cool. + +It's just a tool. + +That's x and y. + +I always get these mixed up. + +So this is called +left rotate of x. + +OK, so here's the thing we can +do with binary search trees. + +It's like the only +thing you need to know. + +Because you've got search +in binary search trees + +and you've got rotations. + +So when I have a tree like this, +I've highlighted two nodes, + +and then there's the +children hanging off of them. + +Some of these might be +empty, but they're trees, + +so we draw them as triangles. + +If I just do this, +which is like changing + +which is higher, x or y, and +whatever the parent of x was + +becomes the parent of y. + +And vice versa, in fact. + +The parent of y was x, and +now the parent of x is y. + +OK, the parent of a is still x. + +The parent of b changes. + +It used to be y. + +Now it's x. + +The parent of c was y. + +It's still y. + +So in a constant number +of pointer changes, + +I can go from this to this. + +This is constant time. + +And more importantly, it +satisfies the BST order + +property. + +If you do an in-order +traversal of this, + +you will get a, x, b, y, c. + +If I do an in-order traversal +over here, I get a, x, b, y, c. + +So they're the same. + +So it still has BST ordering. + +You can check more formally. + +b has all the nodes +between x and y. + +Still all the nodes +between x and y, and so on. + +You can check it at +home, but this works. + +We call it a left rotate because +the root moves to the left. + +You can go straight back +where you came from. + +This would be a +right rotate of y. + +OK, it's a reversible operation. + +It lets you manipulate the tree. + +So when we have this +picture and we're + +really sad because this +looks like a mess, what + +we'd like to do is fix it. + +This is a path of three nodes. + +We'd really prefer +it to look like this. + +If we could make that +transformation, we'd be happy. + +And we can. + +It is a right rotate of 29. + +So that's what +we're going to do. + +So let me quickly copy. + +I want to rotate 29 +to the right, which + +means 29 and 26-- this is x. + +This is y. + +I turn them, and so +I get 26 here now, + +and 29 is the new right child. + +And then whatever +was the left child + +of x becomes the left +child of x in the picture. + +You can check it. + +So this used to +be the triangle a. + +And in this case, +it's just the node 23. + +And we are happy. + +Except I didn't +draw the whole tree. + +Now we're happy because +we have an AVL tree again. + +Good news. + +So just check. + +This is even. + +This is right heavy. + +This is even. + +This is left heavy still. + +This is left heavy, +even, even, even. + +OK, so now we have an AVL tree +and our beauty is restored. + +I'll do one more example. + +Insert 55. + +We want to insert 55 here. + +And what changes is +now this is even. + +This is right heavy. + +This is doubly left heavy. + +We're super sad. + +And then we don't look +above that until later. + +This is more +annoying, because you + +look at this thing, +this little path. + +It's a zigzag path, if you will. + +If I do a right rotation +where this is x and this + +is y, what I'll get is +x, y, and then this is b. + +This is what's in +between x and y. + +And so it'll go here. + +And now it's a zag zig +path, which is no better. + +The height's the same. + +And we're sad. + +I told you, though, +that somehow rotations + +are all we need to do. + +What can I do? + +How could I fix +this little zigzag? + +Just need to think +about those three nodes, + +but all I give +you are rotations. + +AUDIENCE: Perhaps rotate 50. + +PROFESSOR: Maybe rotate 50. + +That seems like a good idea. + +Let's try it. + +If you don't mind, I'm +just going to write 41, + +and then there's all +the stuff on the left. + +Now we rotate 50. + +So 65 remains where it is. + +And we rotate 50 to the left. + +So 50 and its child. + +This is x. + +This is y. + +And so I get 55 and I get 50. + +Now, this is bad from +an AVL perspective. + +This is still doubly left +heavy, this is left heavy, + +and this is even. + +But it looks like this case. + +And so now I can do a +right rotation on 65, + +and I will get-- so let me +order the diagrams here. + +I do a right rotate on +65, and I will get 41. + +And to the right I get 55. + +And to the right I get 65. + +To the left I get 50. + +And then I get the left subtree. + +And so now this is +even, even, even. + +Wow. + +How high was left subtree? + +I think it's still left heavy. + +Cool. + +This is what some people +call double rotation, + +but I like to call +it two rotations. + +It's whatever you prefer. + +It's not really a new operation. + +It's just doing two rotations. + +So that's an example. + +Let's do the general case. + +It's no harder. + +You might say, oh, gosh, +why do you do two examples? + +Well, because they +were different. + +And they're are two +cases on the algorithm. + +You need to know both of them. + +OK, so AVL insert. + +Here we go. + +Fix AVL property. + +I'm just going to call this +from the changed node up. + +So the one thing that's +missing from these examples + +is that you might have to +do more than two rotations. + +What we did was look at the +lowest violation of the AVL + +property and we fixed it. + +When we do that, +there's still may + +be violations higher up, +because when you add a node, + +you change the height +of this subtree, + +the height of this subtree, +the height of this subtree, + +and the height of this +subtree, potentially. + +What happened in these +cases when I was done, + +what I did fixed one violation. + +They were all fixed. + +But in general, there might be +several violations up the tree. + +So that's what we do. + +Yeah, I'll leave it at that. + +So suppose x is the lowest +node that is not AVL. + +The way we find that node +is we start at the node + +that we changed. + +We check if that's OK. + +We update the heights as we +go up using our simple rule. + +And that's actually not our +simple rule, but it's erased. + +We update the height based on +the heights of its children. + +And you keep +walking up until you + +see, oh, the left is twice, +two times-- or not two times, + +but plus 2 larger than +the left, or vice versa. + +Then you say, oh, that's bad. + +And so we fix it. + +Yeah, question. + +AUDIENCE: So here we +continue to [INAUDIBLE]. + +PROFESSOR: Yes. + +AUDIENCE: [INAUDIBLE]. + +add n to the level +[INAUDIBLE] than 1. + +So add [INAUDIBLE]. + +PROFESSOR: AVL property's +not about levels. + +It's about left subtrees +and right subtrees. + +So the trouble is that 65-- +you have a left subtree, which + +has height 2-- or sorry, +height 1, I guess-- + +because the longest path +from here to a leaf is 1. + +The right subtree +has height negative 1 + +because it doesn't exist. + +So it's one versus negative 1. + +So that's why there's +a double arrow. + +Yeah, good to ask. + +It's weird with the negative 1s. + +That's also why I wanted to +define those negative 1s to be + +there, so the AVL property +is easier to state. + +Other questions? + +All right. + +Good. + +I think I want a +symmetry assumption here. + +I don't know why I +wrote right of x. + +I guess in modern days +we write x dot right. + +Same thing. + +OK, I'm going to assume that +the right child is the heavier + +one like we did before. + +Could be the left. + +It's symmetric. + +It doesn't matter. + +So now there are two +cases, like I said. + +I'm going to use +this term right heavy + +because it's super convenient. + +OK, right heavy +is what I've been + +drawing by a +descending right arrow. + +Balance is what I've been +drawing by a horizontal line. + +OK, so we're just distinguishing +between these two cases. + +This turns out to +be the easy case. + +So we have x, y, a, b, c. + +Why are we looking +at the right child? + +Because we assumed that the +right one is higher, so that x + +was right heavy. + +So this subtree as I've drawn +it is higher than the left one + +by 2, in fact. + +And what we do in this +case is right rotate of x. + +And so we get x, y, a, b, c. + +I could have drawn this no +matter what case we're in, + +so we need to check +this actually works. + +That's the interesting part. + +And that's over here. + +OK, so I said x is right +heavy, in fact doubly so. + +y is either right +heavy or balanced. + +Let's start with right heavy. + +So when we do this rotation, +what happens to the heights? + +Well, it's hard to tell. + +It's a lot easier to think about +what the actual heights are + +than just these arrows. + +So let's suppose x has height k. + +That's pretty generic. + +And it's right +heavy, so that means + +the y has height k minus 1. + +And then this is right heavy, +so this has height k minus 2. + +And this is something +smaller then k minus 2. + +In fact, because this +is AVL, we assume + +that x was the lowest +that is not AVL. + +So y is AVL. + +And so this is going +to be k minus 3, + +and this is going to be k minus +3 because these differ by 2. + +You can prove by a simple +induction you never + +get more than 2 out of whack +because we're just adding 1, + +off by 1. + +So we got off by 2. + +So this is the bad situation. + +Now we can just update +the heights over here. + +So k minus 3 for a, k minus +3 for b, k minus 2 for c. + +Those don't change because +we didn't touch those trees, + +and height is about +going down, not up. + +And so this becomes k minus +2, and this becomes k minus 1. + +And so we changed the +height of the root, + +but now you can see +that life is good. + +This is now balanced between +k minus 3 and k minus 3. + +This is now balanced between +k minus 2 and k minus 2. + +And now the parent of +y may be messed up, + +and that's why after this +we go to the parent of y, + +see if it's messed up, but +keep working our way up. + +But it worked. + +And in the interest +of time, I will not + +check the case +where y is balanced, + +but it works out, too. + +And see the notes. + +So the other case is +where we do two rotations. + +And in general, so here +x was doubly right heavy. + +And the else case is +when the right child + +of x, which I'm going to +call z here, is left heavy. + +That's the one +remaining situation. + +You do the same +thing, and you check + +that right rotating and +left rotating, which + +makes the nice picture, +which is x, y, z, + +actually balances everything and +you restore the AVL property. + +So again, check +the notes on that. + +I have a couple minutes +left, and instead I'd + +like to tell you a +little bit about how + +this fits into big-picture land. + +Two things I want to talk about. + +One is you could +use this, of course, + +to sort, which is, if you +want to sort n numbers, + +you insert them and you +do in-order traversal. + +How long does this take? + +In-order traversal +takes linear time. + +That's the sense in which we're +storing things in sorted order. + +Inserting n items-- well, +each insert takes h time, + +but now we're guaranteed +that h is order log n. + +So all the insertions take log +n time each, n log n total. + +So this is yet another way to +sort n items in n log n time, + +in some ways the +most powerful way. + +We've seen heaps, and +we've seen merge sort. + +They all sort. + +Heaps let you do two operations, +insert and delete min, which + +a lot of times is all you +care about, like in p set two. + +But these guys, +AVL trees, let you + +do insert, delete, +and delete min. + +So they're the same +in those senses, + +but we have the new +operation, which + +is that we can do find next +larger and next smaller, aka + +successor and predecessor. + +So you can think about what +we call an abstract data type. + +These are the operations +that you support, + +or that you're +supposed to support. + +If you're into Java, you +call this an interface. + +But this is an +algorithmic specification + +of what your data structure +is supposed to do. + +So we have operations +like insert and delete. + +We have operations +like find the min + +and things like successor +and predecessor, + +or next larger, next smaller. + +You can take any subset of these +and it's an abstract data type. + +Insert, delete, and min is +called a priority queue. + +So if you just take +these first two, + +it's called a priority queue. + +And there are many +priority queues. + +This is a generic thing +that you might want to do. + +And then the data +structure on the other side + +is how you actually do it. + +This is the analog +of the algorithm. + +OK, this is the specification. + +You want a priority queue. + +One way to do it is a heap. + +Another way to do +it is an AVL tree. + +You could do it +with a sorted array. + +You could do lots of +sub-optimal things, too, + +but in particular, heaps +get these two operations. + +If you want all +three, you basically + +need a balanced +binary search tree. + +There are probably a dozen +balanced binary search trees + +out there, at least a dozen +balanced search trees, + +not all binary. + +They all achieve log n. + +So it doesn't really matter. + +There are various practical +issues, constant factors, + +things like that. + +The main reason you prefer a +heap is that it's in place. + +It doesn't use any extra space. + +Here, you've got pointers +all over the place. + +You lose a constant +factor in space. + +But from a theoretical +standpoint, + +if you don't care +about constant factors, + +AVL trees are really good +because they get everything + +that we've seen +so far and log n. + +And I'll stop there. \ No newline at end of file diff --git a/FPEMBWg_WlY.txt b/FPEMBWg_WlY.txt new file mode 100644 index 0000000000000000000000000000000000000000..90dfa39f258b297853f7e05684f3339edf067d80 --- /dev/null +++ b/FPEMBWg_WlY.txt @@ -0,0 +1,2833 @@ +-- valuable experience. +OK, today we're going to start + +talking about a particular class +of algorithms called greedy + +algorithms. +But we're going to do it in the + +context of graphs. +So, I want to review a little + +bit about graphs, +which mostly you can find in + +the textbook in appendix B. +And so, if you haven't reviewed + +in appendix B recently, +please sit down and review + +appendix B. +It will pay off especially + +during our take-home quiz. +So, just reminder, + +a digraph, what's a digraph? +What's that short for? + +Directed graph, +OK? + +Directed graph, +G equals (V,E), + +OK, has a set, +V, of vertices. + +And, I always get people +telling me that I have one + +vertice. +The singular is not vertice; + +it is vertex, +OK? + +The plural is vertices. +The singular is vertex. + +It's one of those weird English +words. + +It's probably originally like +French or something, + +right? +I don't know. + +OK, anyway, and we have a set, +E, which is a subset of V cross + +V of edges. +So that's a digraph. + +And undirected graph, +E contains unordered pairs. + +OK, and, sorry? +It's Latin, OK, + +so it's probably pretty old, +then, in English. + +I guess the vertex would be a +little bit of a giveaway that + +maybe it wasn't French. +It started to be used in 1570, + +OK. +OK, good, OK, + +so the number of edges is, +whether it's directed or + +undirected, is O of what? +V^2, good. + +OK, and one of the conventions +that will have when we're + +dealing, once we get into +graphs, we deal a lot with sets. + +We generally drop the vertical +bar notation within O's just + +because it's applied. +It just makes it messier. + +So, once again, +another abuse of notation. + +It really should be order the +size of V^2, but it just messes + +up, I mean, it's just more stuff +to write down. + +And, you're multiplying these +things, and all those vertical + +bars. +Since they don't even have a + +sense to the vertical bar, +it gets messy. + +So, we just drop the vertical +bars there when it's in + +asymptotic notation. +So, E is order V^2 when it's a + +set of pairs, +because if it's a set of pairs, + +it's at most n choose two, +which is where it's at most n^2 + +over 2, here it could be, +at most, sorry, + +V^2 over 2, here it's at most +V^2. + +And then, another property that +sometimes comes up is if the G + +is connected, +we have another bound, + +implies that the size of E is +at least the size of V minus + +one. +OK, so if it's connected, + +meaning, what does it mean to +have a graph that's connected? + +Yeah, there's a path from any +vertex to any other vertex in + +the graph. +That's what it means to be + +connected. +So if that's the case, + +that a number of edges is at +least the number of vertices + +minus one, OK? +And so, what that says, + +so one of the things we'll get +into, a fact that I just wanted + +to remind you, +is that in that case, + +if I look at log E, +OK, log of the number of edges, + +that is O of log V. +And by this, + +is omega of log V. +So, it's equal to theta of log + +V. +OK, so basically the number of, + +in the case of a connected +graph, the number of edges, + +and the number of vertices are +polynomially related. + +So, their logs are comparable. +OK, so that's helpful just to + +know because sometimes I just +get questions later on where + +people will say, +oh, you showed it was log E but + +you didn't show it was log V. +And I could point out that it's + +the same thing. +OK, so there's various ways of + +representing graphs in +computers, and I'm just going to + +cover a couple of the important +ones. + +There's actually more. +We'll see some more. + +So, the simplest one is what's +called an adjacency matrix. + +An adjacency matrix of the +graph, G, equals (V,E), + +where, for simplicity, +I'll let V be the set of + +integers from one up to n, +OK, is the n by n matrix A + +given by the ij-th at the entry +is simply one if the edge, + +ij, is in the edge set and zero +if ij is not in the edge set. + +OK, so it's simply the matrix +where you say, + +the ij entry is one if it's in +the matrix. + +So, this is, +in some sense, + +giving you the predicate for, +is there an edge from i to j? + +OK, remember, +predicate is Boolean formula + +that is either zero or one, +and in this case, + +you're saying it's one if there +is an edge from i to j and zero + +otherwise. +OK, sometimes you have edge + +weighted graphs, +and then sometimes what people + +will do is replace this by edge +weights. + +OK, it will be the weight of +the edge from i to j. + +So, let's just do an example of +that just to make sure that our + +intuition corresponds to our +mathematical definitions. + +So, here's an example graph. +Let's say that's our graph. + +So let's just draw the +adjacency the matrix. + +OK, so what this says: +is there's an edge from one to + +one? +And the answer is no. + +Is there an edge from one to +two? + +Yes. +Is there an edge from one to + +three here? +Yep. + +Is there an edge for one to +four? + +No. +Is there an edge from two until + +one? +No. + +Two to two? +No. + +Two to three? +Yes. + +Two to four? +No. + +No edges going out of three. +Edge from four to three, + +and that's it. +That's the adjacency matrix for + +this particular graph, +OK? + +And so, I can represent a graph +as this adjacency matrix. + +OK, when I represent it in this +way, how much storage do I need? + +OK, n^2 or V^2 because the size +is the same thing for V^2 + +storage, OK, and that's what we +call a dense representation. + +OK, it works well when the +graph is dense. + +So, the graph is dense if the +number of edges is close to all + +of the edges possible. +OK, then this is a good + +representation. +But for many types of graphs, + +the number of edges is much +less than the possible number of + +edges, in which case we say the +graph is sparse. + +Can somebody give me an example +of a sparse graph? + +A class of graphs: +so, I want a class of graphs + +that as n grows, +the number of edges in the + +graph doesn't grow as the +square, but grows rather as + +something much smaller. +A linked list, + +so, a chain, +OK, if you look at it from a + +graph theoretically, +is a perfectly good example: + +only n edges in the chain for a +chain of length n. + +So therefore, +the number of edges would be + +order V. +And in particular, + +you'd only have one edge per +row here. + +What other graphs are sparse? +Yeah? + +Good, a planar graph, +a graph that can be drawn in a + +plane turns out that if it has V +vertices has, + +and V is at least three, +then it has, + +at most, three V minus six +edges. + +So, it turns out that's order V +edges again. + +What's another example of a +common graph? + +Yeah, binary tree, +or even actually any tree, + +you know, what's called a free +tree if you read the appendix, + +OK, a tree that just is a +connected graph that has no + +cycles, OK, is another example. +What's an example of a graph + +that's dense? +A complete graph, + +OK: it's all ones, +OK, or if you have edge + +weights, it would be a +completely filled in matrix. + +OK, good. +So, this is good for dense + +representation. +But sometimes you want to have + +a sparse representation so we +don't have to spend V^2 space to + +deal with all of the, +where most of it's going to be + +zeroes. +OK, it's sort of like, + +if we know why it's zero, +why bother representing it as + +zero? +So, one such representation is + +an adjacency list +representation. + +Actually, adjacency list of a +given vertex is the list, + +which we denote by Adj of V, +of vertices adjacent to V. + +OK, just in terms by their +terminology, vertices are + +adjacent, but edges are incident +on vertices. + +OK, so the incidence is a +relation between a vertex and an + +edge. +An adjacency is a relation + +between two vertices. +OK, that's just the language. + +Why they use to different +terms, I don't know, + +but that's what they do. +So, in the graph, + +for example, +the adjacency list for vertex + +one is just the list or the set +of two three because one has + +going out of one are edges to +two and three. + +The adjacency list for two is +just three, four, + +three. +It's the empty set, + +and for four, +it is three. + +OK, so that's the +representation. + +Now, if we want to figure out +how much storage is required for + +this representation, +OK, we need to understand how + +long the adjacency list is. +So, what is the length of an + +adjacency list of a vertex, +V? + +What name do we give to that? +It's the degree. + +So, in an undirected graph, +we call it the degree of the + +vertex. +This is undirected. + +OK, about here, +OK. + +So that's an undirected case. +In the directed case, + +OK, actually I guess the way we +should do this is say this. + +If the degree, +we call it the out degree for a + +digraph. +OK, so in a digraph, + +we have an out degree and an in +degree for each vertex. + +So here, the in degree is +three. + +Here, the out degree is two, +OK? + +So, one of the important lemma +that comes up is what's called + +the handshaking lemma. +OK, it's one of these + +mathematical lemmas. + +And so, it comes from a story. +Go to a dinner party, + +and everybody at the dinner +party shakes other people's + +hands. +Some people may not shake + +anybody's hand. +Some people may shake several + +people's hands. +Nobody shakes hands with + +themselves. +And at some point during the + +dinner party, +the host goes around and counts + +up how many, the sum, +of the number of hands that + +each person has shaken. +OK, so he says, + +how many did you shake? +How many did you shake? + +How many did you shake? +He adds them up, + +OK, and that number is +guaranteed to be even. + +OK, that's the handshaking +lemma. + +Or, stated a little bit more +precisely, if I take for any + +graph the degree of the vertex, +and sum them all up, + +that's how many hands everybody +shook, OK, that's actually equal + +to always twice the number of +edges. + +So, why is that going to be +true? + +Why is that going to be twice +the number of edges? + +Yeah? +Yeah. + +Every time you put in an edge, +you add one to the degree of + +each person on each end. +So, it's just two different + +ways of counting up the same +number of edges. + +OK, I can go around, +and if you imagine that, + +that every time I count the +degree of the node, + +I put a mark on every edge. +Then, when I'm done, + +every edge has two marks on it, +one for each end. + +OK: a pretty simple theorem. +So, what that says is that for + +undirected graphs, +that implies that the adjacency + +list representation, +uses how much storage? + +OK, at most, +2E, so order E because that's + +not all. +Yeah, so you have to have the + +number of vertices plus order +the number of edges, + +OK, whether it's directed or +undirected because I may have a + +graph, say it has a whole bunch +of vertices and no edges, + +that's still going to cost me +order V, OK? + +So, it uses theta of V plus E +storage. + +And, it's basically the same +thing asymptotically. + +In fact, it's easier to see in +some sense for digraphs because + +for digraphs, +what I do is I just add up the + +out degrees, and that equal to +E, OK, if I add up the out + +degrees as equally. +In fact, this is kind of like + +it amortized analysis, +if you will, + +a book keeping analysis, +that if I'm adding up the total + +number of edges, +one way of doing it is + +accounting for a vertex by +vertex. + +OK, so for each vertex, +I basically can take each + +degree, and basically each +vertex, look at the degree, + +and that allocating of account +per edge, and then ending up + +with twice the number of edges, +that's exactly accounting type + +of analysis that we might do for +amortized analysis. + +OK, so we'll see that. +So, this is a sparse + +representation, +and it's often better than an + +adjacency matrix. +For example, + +you can imagine if the World +Wide Web were done with an + +adjacency matrix as opposed to, +essentially, + +with an adjacency list type of +representation. + +Every link on the World Wide +Web, I had to say, + +here are the ones that I'm +connected to, + +and here are all the ones I'm +not connected to. + +OK, that list of things you're +not connected to for a given + +page would be pretty +dramatically, + +show you that there is an +advantage to sparse + +representation. +On the other hand, + +one of the nice things about an +adjacency matrix representation + +is that each edge can be +represented with a single bit, + +whereas typical when I'm +representing things with an + +adjacency list representation, +how many bits am I going to + +need to represent each +adjacency? + +You'll need order log of V to +be able to name each different + +vertex. +OK, the log of the number is + +the number of bits that I need. +So, there are places where this + +is actually a far more efficient +representation. + +In particular, +if you have a very dense graph, + +OK, this may be a better way of +representing it. + +OK, the other thing I want you +to get, and we're going to see + +more of this in particular next +week, is that a matrix and a + +graph, there are two ways of +looking at the same thing. + +OK, and in fact, +there's a lot of graph theory + +that when you do things like +multiply the adjacency matrix, + +OK, and so forth. +So, there's a lot of + +commonality between graphs and +matrices, a lot of mathematics + +that if it applies for one, +it applies to the other. + +Do you have a question, +or just holding your finger in + +the air? +OK, good. + +OK, so that's all just review. +Now I want to get onto today's + +lecture. +OK, so any questions about + +graphs? +So, this is a good time to + +review appendix B. +there are a lot of great + +properties in there, +and in particular, + +there is a theorem that we're +going to cover today that we're + +going to talk about today, +which is properties of trees. + +Trees are very special kinds of +graphs, so I really want you to + +go and look to see what the +properties are. + +There is, I think, +something like six different + +definitions of trees that are +all equivalent, + +OK, and so, I think a very good +idea to go through and read + +through that theorem. +We're not going to prove it in + +class, but really, +provides a very good basis for + +the thinking that we're going to +be doing today. + +And we'll see more of that in +the future. + +OK, so today, +we're going to talk about + +minimum spanning trees. +OK, this is one of the world's + +most important algorithms. +OK, it is important in + +distributed systems. +It's one of the first things + +that almost any distributed +system tries to find is a + +minimum spanning tree of the +nodes that happened to be alive + +at any point, +OK? + +And one of the people who +developed an algorithm for this, + +we'll talk about this a little +bit later, OK, + +it was the basis of the billing +system for AT&T for many years + +while it was a monopoly. +OK, so very important kind of + +thing. +It's got a huge number of + +applications. +So the problem is the + +following. +You have a connected undirected + +graph, +G equals (V,E), + +with an edge weight function, +w, which maps the edges into + +weights that are real numbers. +And for today's lecture, + +we're going to make an +important assumption, + +OK, for simplicity. +The book does not make this + +assumption. +And so, I encourage you to look + +at the alternative presentation +or, because what they do in the + +book is much more general, +but for simplicity and + +intuition, I'm going to make +this a little bit easier. + +We're going to assume that all +edge weights are distinct. + +OK, all edge weights are +distinct. + +So what does that mean? +What does that mean that this + +function, w, what property does +the function, + +w, have if all edge weights are +distinct? + +Who remembers their discreet +math? + +It's injective. +OK, it's one to one. + +OK, it's not one to one and +onto necessarily. + +In fact, it would be kind of +hard to do that because that's a + +pretty big set. +OK, but it's one to one. + +It's injective. +OK, so that's what we're going + +to assume for simplicity. +OK, and the book, + +they don't assume that. +It just means that the way you + +have to state things is just a +little more precise. + +It has to be more technically +precise. + +So, that's the input. +The output is-- + +The output is a spanning tree, +T, and by spanning tree, + +we mean it connects all the +vertices. + +OK, and it's got to have +minimum weight. + +OK, so we can write the weight +of the tree is going to be, + +by that, we meet the sum over +all edges that are in the tree + +of the weight of the individual +edges. + +OK, so here I'(V,E) done a +little bit of abusive notation, + +which is that what I should be +writing is w of the edge (u,v) + +because this is a mapping from +edges, which would give me a + +double parentheses. +And, you know, + +as you know, +I love to abuse notation. + +So, I'm going to drop that +extra parentheses, + +because we understand that it's +really the weight of the edge, + +OK, not the weight of the +ordered pair. + +So, that's just a little +notational convenience. + +OK, so one of the things, +when we do the take-home exam, + +notational convenience can make +the difference between having a + +horrible time writing up a +problem, and an easy time. + +So, it's worth thinking about +what kinds of notation you'll + +use in writing up solutions to +problems, and so forth. + +OK, and just in general, +a technical communication, + +you adopt good notation people +understand you. + +You adopt a poor notation: +nobody pays attention to what + +you're doing because they don't +understand what you're saying. + +OK, so let's do an example. + +OK, so here's a graph. +I think for this, + +somebody asked once if I was +inspired by biochemistry or + +something, OK, +but I wasn't. + +I was just writing these things +down, OK? + +So, here's a graph. +And let's give us some edge + +weights. + +OK, so there are some edge +weights. + +And now, what we want is we +want to find a tree. + +So a connected acyclic graph +such that every vertex is part + +of the tree. +But it's got to have the + +minimum weight possible. +OK, so can somebody suggest to + +me some edges that have to be in +this minimum spanning tree? + +Yeah, so nine, +good. + +Nine has to be in there +because, why? + +It's the only one connecting it +to this vertex, + +OK? +And likewise, + +15 has to be in there. +So those both have to be in. + +What other edges have to be in? +Which one? + +14 has to be it. +Why does 14 have to be in? + +Well, one of 14 and three has +to be in there. + +I want the minimum weight. +The one that has the overall + +smallest weight. +So, can somebody argue to me + +that three has to be in there? +Yeah? + +That's the minimum of two, +which means that if I had a, + +if you add something you said +was a minimum spanning tree that + +didn't include three, +right, and so therefore it had + +to include 14, +then I could just delete this + +edge, 14, and put in edge three. +And, I have something of lower + +weight, right? +So, three has to be in there. + +What other edges have to be in +there? + +Do a little puzzle logic. +Six and five have to be in + +there. +Why do they have to be in + +there? + +Yeah, well, I mean, +it could be connected through + +this or something. +It doesn't necessarily have to + +go this way. +Six definitely has to be in + +there for the same reason that +three had to be, + +right? +Because we got two choices to + +connect up this guy. +And so, if everything were + +connected but it weren't, +12, I mean, and 12 was in + +there. +I could always, + +then, say, well, +let's connect them up this way + +instead. +OK, so definitely that's in + +there. +I still don't have everything + +connected up. + +What else has to be in there +for minimum spanning tree? + +Seven, five, +and eight, why seven, + +five, and eight? +OK, so can we argue those one + +at a time? +Why does five have to be in + +there? +Yeah? + +OK, so we have four connected +components because we have this + +one, this one, +we actually have, + +yeah, this one here, +and this one, + +good. +We need at least three edges to + +connect them because each edge +is going to reduce the connected + +components by one. +OK, so we need three edges, + +and those are the three +cheapest ones. + +And they work. +That works, right? + +Any other edges are going to be +bigger, so that works. + +Good. +OK, and so, now do we have a + +spanning tree? +Everything is, + +we have one big connected graph +here, right? + +Is that what I got? +Hey, that's the same as what I + +got. +Life is predictable. + +OK, so, so everybody had the +idea of what a minimum spanning + +tree is, then, +out of this, + +OK, what's going on there? +So, let's first of all make + +some observations about this +puzzle. + +And what I want to do is remind +you about the optimal + +substructure property because it +turns out minimum spanning tree + +has a great optimal substructure +property. + +OK, so the setup is going to +be, we're going to have some + +minimum spanning tree. +Let's call it T. + +And, I'm going to show that +with the other edges in the + +graph, are not going to be +shown. + +OK, so here's a graph. + +OK, so here's a graph. +It looks like the one I have my + +piece of paper here. +OK, so the idea is, + +this is some minimum spanning +tree. + +Now, we want to look at a +property of optimal + +substructure. +And the way I'm going to get + +that, is, I'm going to remove +some edge, (u,v), + +move an arbitrary edge, +(u,v), in the minimum spanning + +tree. +So, let's call this u and this + +V. +And so, we're removing this + +edge. +OK, so when I remove an edge in + +a tree, what happens to the +tree? + +What's left? +I have two trees left, + +OK? +I have two trees left. + +Now, proving that, +that's basically one of the + +properties in that appendix, +and the properties of trees + +that I want you to read, +OK, because you can actually + +prove that kind of thing rather +than it just being obvious, + +which is, OK? +OK, so we remove that. + +Then, T is partitioned into two +subtrees. + +And, we'll call them T_1 and +T_2. + +So, here's one subtree, +and here's another subtree. + +We'(V,E) partitioned it. +No matter what edge I picked, + +there would be two subtrees +that it's partitioned into. + +Even if the sub tree is a +trivial subtree, + +for example, +it just has a single node in it + +and no edges. + +So, the theorem that we'll +prove demonstrates a property of + +optimal substructure. +T_1 is a minimum spanning tree + +for the graph, +G_1, E_1, + +a subgraph of G induced by the +vertices in T_1. + +OK, that is, +V_1 is just the vertices in T_1 + +is what it means to be induced. +OK, so V_1 is the vertices in + +T_1. +So, in this picture, + +I didn't label it. +This is T_1. + +This is T_2. +In this picture, + +these are the vertices of T_1. +So, that's V_1, + +OK? +And, E_1 is the set of pairs of + +vertices, x and y, +that are the edges that are in + +E_1 such that both x and y +belong to V_1. + +OK, so I haven't shown the +edges of G here. + +But basically, +if an edge went from here to + +here, that would be in the E_1. +If it went from here to here, + +it would not. +And if it went from here to + +here, it would not. +OK, so the vertices, + +the subgraph induced by the +vertices of T_1 are just those + +that connect up things in T_1, +and similarly for T_2. + +So, the theorem says that if I +look at just the edges within + +the graph here, +G_1, those that are induced by + +these vertices, +T_1 is, in fact, + +a minimum spanning tree for +that subgraph. + +That's what the theorem says. +OK, if I look over here + +conversely, or correspondingly, +if I look at the set of edges + +that are induced by this set of +vertices, the vertices in T_2, + +in fact, T_2 is a minimum +spanning tree on that subgraph. + +OK, OK, we can even do it over +here. + +If I took a look, +for example, + +at these, let's see, +let's say we cut out five, + +and if I cut out edge five, +that T_1 would be these four + +vertices here. +And, the point is that if I + +look at the subgraph induced on +that, that these edges here. + +In fact, the six, +eight, and three are all edges + +in a minimum spanning tree for +that subgraph. + +OK, so that's what the theorem +says. + +So let's prove it. + +OK, and so what technique are +we going to use to prove it? + +OK, we learned this technique +last time: hint, + +hint. +It's something you do it in + +your text editor all the time: +cut and paste, + +good, cut and paste. +OK, so the weight of T I can + +express as the weight of the +edge I removed, + +plus the weight of T_1, +plus the weight of T_2. + +OK, so that's the total weight. +So, the argument is pretty + +simple. +Suppose that there were some + +T_1 prime that was better than +T_1 for G_1. + +Suppose I had some better way +of forming a spanning tree. + +OK, then I would make up a T +prime, which just contained the + +edges, (u,v), +and T_1 prime, + +union T_2. +So, I would take, + +if I had a better spanning +tree, a spanning tree of lower + +weight for T_1. +And I call that T_1 prime. + +I just substitute that and make +up a spanning tree that + +consisted of my edge, +(u,v), whatever works well for + +T_1 prime and whatever works +well for T. + +And, that would be a spanning +tree. + +And it would be better than T +itself was for G, + +OK, because the weight of these +is just as the weight for this, + +I now just get to use the +weight of T_1 prime, + +and that's less. +And so, therefore, + +the assumption that T was a +minimum spanning tree would be + +violated if I could find a +better one for the subpiece. + +So, we have this nice property +of optimal substructure. + +OK, I have subproblems that +exhibit optimal, + +if I have a globally optimal +solution to the whole problem + +within it, I can find optimal +solutions to subproblems. + +So, now the question is, +that's one hallmark. + +That's one hallmark of dynamic +programming. + +What about overlapping +subproblems? + +Do I have that property? +Do I have overlapping + +subproblems over here for this +type of problem? + +So, imagine, +for example, + +that I'm removing different +edges. + +I look at the space of taking a +given edge, and removing it. + +It partitions it into two +pieces, and now I have another + +piece. +And I remove it, + +etc. +Am I going to end up getting a + +bunch of subproblems that are +similar in there? + +Yeah, I am. +OK, if I take out this one, + +then I take out, +say, this one here, + +and then I'll have another tree +here and here. + +OK, that would be the same as +if I had originally taken this + +out, and then taken that one +out. + +If I look at simple ordering of +taking out the edges, + +I'm going to end up with a +whole bunch of overlapping + +subproblems. +Yeah, OK. + +So then, what does that suggest +we use as an approach? + +Dynamic programming, +good. + +What a surprise! +Yes, OK, you could use dynamic + +programming. +But it turns out that minimum + +spanning tree exhibits an even +more powerful property. + +OK, so we'(V,E) got all the +clues for dynamic programming, + +but it turns out that there's +an even bigger clue that's going + +to help us to use an even more +powerful technique. + +And that, we call, +the hallmark for greedy + +algorithms. + +And that is, +we have a thing called the + +greedy choice property, +which says that a locally + +optimal choice is globally +optimal. + +And, of course, +as all these hallmarks is the + +kind of thing you want to box, +OK, because these are the clues + +that you're going to be able to +do that. + +So, we have this property that +we call the greedy choice + +property. +I'm going to show you how it + +works in this case. +And when you have a greedy + +choice property, +it turns out you can do even + +better that dynamic programming. +OK, so when you see the two + +dynamic programming properties, +there is a clue that says + +dynamic programming, +yes, but also it says, + +let me see whether it also has +this greedy property because if + +it does, you're going to come up +with something that's even + +better than dynamic programming, +OK? + +So, if you just have the two, +you can usually do dynamic + +programming, but if you have +this third one, + +it's like, whoa! +Jackpot! + +OK, so here's the theorem we'll +prove to illustrate this idea. + +Once again, these are not, +all these hallmarks are not + +things. +They are heuristics. + +I can't give you an algorithm +to say, here's where dynamic + +programming works, +or here's where greedy + +algorithms work. +But I can sort of indicate when + +they work, the kind of structure +they have. + +OK, so here's the theorem. +So let's let T be the MST of + +our graph. +And, let's let A be any subset + +of V, so, some subset of +vertices. + +And now, let's suppose that +edge, (u,v), is the least weight + +edge connecting our set A to A +complement, that is, + +V minus A. +Then the theorem says that + +(u,v) is in the minimum spanning +tree. + +So let's just take a look at +our graph over here and see if + +that's, in fact, +the case. + +OK, so let's take, +so one thing I could do for A + +is just take a singleton node. +So, I take a singleton node, + +let's say this guy here, +that can be my A, + +and everything else is V minus +A. + +And I look at the least weight +edge connecting this to + +everything else. +Well, there are only two edges + +that connect it to everything +else. + +And the theorem says that the +lighter one is in the minimum + +spanning tree. +Hey, I win. + +OK, if you take a look, +every vertex that I pick, + +the latest edge coming out of +that vertex is in the minimum + +spanning tree. +OK, the lightest weight edge + +coming out, but that's not all +the edges that are in here. + +OK, or let's just imagine, +let's take a look at these + +three vertices connected to this +set of vertices. + +I have three edges is going +across. + +The least weight one is five. +That's the minimum spanning + +tree. +Or, I can cut it this way. + +OK, the ones above one, +the edges going down are seven, + +eight, and 14. +Seven is the least weight. + +It's in the minimum spanning +tree. + +So, no matter how I choose, +I could make this one in, + +this one out, +this one in, + +this one out, +this one in, + +this one out, +this one in, + +this one out, +take a look at what all the + +edges are. +Which ever one to the least + +weight: it's in the minimum +spanning tree. + +So, in some sense, +that's a local property because + +I don't have to look at what the +rest of the tree is. + +I'm just looking at some small +set of vertices if I wish, + +and I say, well, +if I wanted to connect that set + +of vertices to the rest of the +world, what would I pick? + +I'd pick the cheapest one. +That's the greedy approach. + +It turns out, +that wins, OK, + +that picking that thing that's +locally good for that subset, + +A, OK, is also globally good. +OK, it optimizes the overall + +function. +That's what the theorem says, + +OK? +So, let's prove this theorem. + +Any questions about this? +OK, let's prove this theorem. + +So, we have (u,v) is the least +weight edge connecting A to D + +minus A. +So, let's suppose that this + +edge, (u,v), is not in the +minimum spanning tree. + +OK, let's suppose that somehow +there is a minimum spanning tree + +that doesn't include this least +weight edge. + +OK, so what technique you think +will use to prove to get a + +contradiction here? +Cut and paste, + +good. +Yeah, we're going to cut paste. + +OK, we're going to cut and +paste. + +So here, I did an example. +OK, so -- + +OK, and so I'm going to use the +notation. + +I'm going to color some of +these in. + +OK, and so my notation here is +this is an element of A, + +and color it in. +It's an element of V minus A. + +OK, so if it's not colored it, +that's an A. + +This is my minimum spanning +tree. + +Once again, I'm not showing the +overall edges of all the graphs, + +but they're there, +OK? + +So, my edge, +(u,v), which is not my minimum + +spanning tree I say, +let's say is this edge here. + +It's an edge from u, +u as in A, v as in V minus A. + +OK, so everybody see the setup? +So, I want to prove that this + +edge should have been in the +minimum spanning tree, + +OK, that the contention that +this is a minimum spanning tree, + +and does include (u,v) is +wrong. + +So, what I want to do, +that, is I have a tree here, + +T, and I have two vertices, +u and v, and in a tree, + +between any two vertices there +is a unique, simple path: + +simple path meaning it doesn't +go back and forth and repeat + +edges or vertices. +OK, there's a unique, + +simple path from u to v. +So, let's consider that path. + +OK, and the way that I know +that that path exists is because + +I'(V,E) read appendix B of the +textbook, section B.5.1, + +OK, which has this nice theorem +about properties of trees. + +OK, so that's how I know that +there exists a unique, + +simple path. +OK, so now we're going to do is + +take a look at that path. +So in this case, + +it goes from here, +to here, to here, + +to here. +And along that path, + +there must be a point where I +connect from a vertex in A to a + +vertex in V minus A. +Why? + +Well, because this is in A. +This is in V minus A. + +So, along the path somewhere, +there must be a transition. + +OK, they are not all in A, +OK, because in particular, + +V isn't. +OK, so we're going to do is + +swap (u,v) with the first edge +on this path that connects a + +vertex in A to a vertex in V +minus A. + +So in this case, +it's this edge here. + +I go from A to V minus A. +In general, I might be + +alternating many times, +OK, and I just picked the first + +one that I encounter. +OK, that this guy here. + +And what I do is I put this +edge in. + +OK, so then, +what happens? + +Well, the edge, +(u,v), is the lightest thing + +connecting something in A to +something in V minus A. + +So that means, +in particular, + +it's lighter than this edge, +has lower weight. + +So, by swapping this, +I'(V,E) created a tree with + +lower overall weight, +contradicting the assumption + +that this other thing was a +minimum spanning tree. + +OK: so, a lower weight spanning +tree than T results, + +and that's a contradiction -- + +-- than T results. +And that's a contradiction, + +OK? +How are we doing? + +Everybody with me? +OK, now we get to do some + +algorithms. +Yea! + +So, we are going to do an +algorithm called Prim's + +algorithm. +Prim eventually became a very + +high-up at AT&T because he +invented this algorithm for + +minimum spanning trees, +and it was used in all of the + +billing code for AT&T for many +years. + +He was very high up at Bell +Labs back in the heyday of Bell + +Laboratories. +OK, so it just shows, + +all you have to do is invent an +algorithm. + +You too can be a president of a +corporate monopoly. + +Of course, the government can +do things to monopolies, + +but anyway, if that's your +mission in life, + +invent an algorithm. +OK, so here's the idea. + +What we're going to do is we're +going to maintain V minus A as a + +priority queue. +We'll call it Q. + +And each vertex, +we're going to key each vertex + +in Q with the weight of the +least weight edge, + +connecting it to a vertex in A. +So here's the code. + +So, we're going to start out +with Q being all vertices. + +So, we start out with A being, +if you will, + +the empty set. +OK, and what we're going to do + +it is the least weight edge, +therefore, for everything in + +the priority queue is basically +going to be infinity because + +none of them have any edges. +The least weight edge to the + +empty set is going to be empty. +And then, we're going to start + +out with one guy. +We'll call him S, + +which will set to zero for some +arbitrary S in V. + +And then, the main part of the +algorithm kicks in. + +So that's our initialization. +OK, when we do the analysis, + +I'm going to write some stuff +on the left hand side of the + +board. +So if you're taking notes, + +you may want to also leave a +little bit of space on the left + +hand side of your notes. +So, while Q is not empty, + +we get the smallest element out +of it. + +And then we do some stuff. + +That's it. +And the only thing I should + +mention here is, +OK, so let's just see what's + +going on here. +And then we'll run it on the + +example. +OK, so what we do is we take + +out the smallest element out of +the queue at each step. + +And then for each step in the +adjacency list, + +in other words, +everything for which I have an + +edge going from v to u, +we take a look, + +and if v is still in our set V +minus A, so things we'(V,E) + +taken out are going to be part +of A. + +OK, every time we take +something out, + +that's going to be a new A that +we construct. + +At every step, +we want to find, + +what's the cheapest edge +connecting that A to everything + +else? +We basically are going to take + +whatever that cheapest thing is, +OK, add that edge in, + +and now bring that into A and +find the next cheapest one. + +And we just keep repeating the +process. + +OK, we'll do it on the example. +And what we do, + +is every time we bring it in, +I keep track of, + +what was the vertex responsible +for bringing me in. + +And what I claim is that at the +end, if I look at the set of + +these pairs that I'(V,E) made +here, V and pi of V, + +that forms the minimum spanning +tree. + +So let's just do this. +And, what's that? + +We're all set up. +So let's get rid of these guys + +here because we are going to +recompute them from scratch. + +OK, so you may want to copy the +graph over again in your notes. + +I was going to do it, +but it turned out, + +this is exactly the board is +going to erase this. + +OK, well let me just modify it. +OK, so we start out. + +We make everything be infinity. +OK, so that's where I'm going + +to keep the key value. +OK, and then what I'm going to + +do is find one vertex. +And I'm going to call him S. + +And I'm going to do this vertex +here. + +We'll call that S. +So basically, + +I now make him be zero. +And now, what I do, + +is I execute extract min. +So basically, + +what I'll do is I'll just shade +him like this, + +indicating that he has now +joined the set A. + +So, this is going to be A. +And this is element of V minus + +A. +OK, so then what we do is we + +take a look. +We extract him, + +and then for each edge in the +adjacency list, + +OK, so for each vertex in the +adjacency lists, + +that these guys here, +OK, we're going to look to see + +if it's still in Q, +that is, in V minus A. + +And if so, and its key value is +less than what the value is at + +the edge, there, +we're going to replace it by + +the edge value. +So, in this case, + +we're going to replace this by +seven. + +We're going to replace this by +15, and we're going to replace + +this by ten, OK, +because what we're interested + +in is, what is the cheapest? +Now, notice that everything in + +V minus A, that is, +what's in the priority queue, + +everything in there, +OK, now has its cheapest way of + +connecting it to the things that +I'(V,E) already removed, + +the things that are in A. +OK, and so now I just, + +OK, when I actually do that +update, there's actually + +something implicit going on in +this priority queue. + +And that is that I have to do a +decreased key. + +So, there's an implicit +decrease of the key. + +So, decreased key is a priority +queue operation that lowers the + +value of the key in the priority +queue. + +And so, that's implicitly going +on when I look at what data + +structure I'm going to use to +implement that priority queue. + +OK, so common data structures +for implementing a priority + +queue are a min heap. +OK, so I have to make sure that + +I'm actually doing this +operation. + +I can't just change it and not +affect my heap. + +So, there is an implicit +operation going on there. + +OK, now I repeat. +I find the cheapest thing, + +oh, and I also have to set, +now, a pointer from each of + +these guys back to u. +So here, this guy sets a + +pointer going this way. +This guy sets a pointer going + +this way, and this guy sets a +pointer going this way. + +That's my pi thing that's going +to keep track of who caused me + +to set my value to what it is. +So now, we go in and we find + +the cheapest thing, +again. + +And we're going to do it fast, +too. + +OK, this is a fast algorithm. +OK, so now we're going to go do + +this again. +So now, what's the cheapest + +thing to extract? +This guy here, + +right? +So, we'll take him out, + +OK, and now we update all of +his neighbors. + +So this guy gets five. +This guy gets 12. + +This guy gets nine. +This guy we don't update. + +We don't update him because +he's no longer in the priority + +queue. +And all of these guys now, + +we make point to where they're +supposed to point to. + +And, we're done with that step. +Now we find the cheapest one. + +What's the cheapest one now? +The five over here. + +Good. +So, we take him out. + +OK, we update the neighbors. +Here, yep, that goes to six + +now. +And, we have that pointer. + +And, this guy we don't do, +because he's not in there. + +This guy becomes 14, +and this guy here becomes + +eight. +So, we update that guy, + +make him be eight. +Did I do this the right way? + +Yeah, because pi is a function +of this guy. + +So basically, +this thing, then, + +disappears. +Yeah, did I have another one + +that I missed? +12, yes, good, + +it's removed, +OK, because pi is just a + +function. +And now I'm OK. + +OK, so now what do I do? +OK, so now my set, + +A, consists of these three +things, and now I want the + +cheapest edge. +I know it's in the minimum + +spanning tree. +So let me just greedily pick + +it. +OK, so what's the cheapest + +thing now? +This guy appear? + +Yeah, six. +So we take it. + +We go to update these things, +and nothing matters here. + +OK, nothing changes because +these guys are already in A. + +OK, so now the cheapest one is +eight here. + +Good. +So, we take eight out. + +OK, we update this. +Nothing to be done. + +This: nothing to be done. +This: oh, no, + +this one, instead of 14 we can +make this be three. + +So, we get rid of that pointer +and make it point that way. + +Now three is the cheapest +thing. + +So, we take it out, +and of course there's nothing + +to be done over there. +And now, last, + +I take nine. +And it's done. + +And 15: it's done. +And the algorithm terminates. + +OK, and as I look at, +now, all the edges that I + +picked, those are exactly all +the edges that we had at the + +beginning. +OK, let's do an analysis here. + +OK, so let's see, +this part here costs me order + +V, right? +OK, and this part, + +let's see what we are doing +here. + +Well, we're going to go through +this loop how many times? + +V times. +It's V elements we put into the + +queue. +We are not inserting anything. + +We're just taking them out. +This goes V times, + +OK, and we do a certain number +of extract Mins. + +So, we're going to do order V +extract Mins. + +And then we go to the adjacency +list, and we have some constant + +things. +But we have these implicit + +decreased keys for this stuff +here. + +That's this thing here. +OK, and so how many implicit + +decreased keys do we have? +That's going to be the + +expensive thing. +OK, we have, + +in this case, +the degree of u of those. + +OK, so overall, +how many implicit decreased + +keys do we have? +Well, we have V times through. + +How big could the degree of u +be? + +OK, it could be as big as V, +order V. + +So, that's V^2 decreased use. +But we can do a better bound + +than that. +How many do we really have? + +Yeah, at most order E, +OK, because what am I doing? + +I'm summing up the degrees of +all the vertices. + +That's how many times I +actually execute that. + +So, I have order E, +implicit decreased keys. + +So the time overall is order V +times time for whatever the + +extract Min is plus E times the +time for decreased key. + +So now, let's look at data +structures, and we can evaluate + +for different data structures +what this formula gives us. + +So, we have different ways of +implementing a data structure. + +We have the cost of extract +Min, and of decreased key, + +and total. +So, the simplest way of + +implementing a data structure is +an unsorted array. + +If I have an unsorted array, +how much time does it take me + +to extract the minimum element? +If I have an unsorted array? + +Right, order V in this case +because it's an array of size V. + +And, to do a decreased key, +OK, I can do it in order one. + +So, the total is V^2, +good, order V^2 algorithm. + +Or, as people suggested, +how about a binary heap? + +OK, to do an extract Min in a +binary heap will cost me what? + +O of log V. +Decreased key will cost me, + +yeah, it turns out you can do +that in order log V because + +basically you just have to +shuffle the value, + +actually shuffle it up towards +the root, OK? + +Or at log V. +And, the total cost therefore + +is? +E log V, good. + +Which of these is better? +It depends, good. + +When is one better, +and when is the other better? + +Yeah, if it's a dense graph, +E is close to V^2, + +the array is better. +But if it's a sparse graph, + +and E is much smaller than V^2, +then the binary heap is better. + +So that motivated the invention +of a data structure, + +OK, called a Fibonacci Heap. +So, Fibonacci Heap is covered + +in Chapter 20 of CLRS. +We're not going to hold you + +responsible for the content, +but it's an interesting data + +structure because it's an +amortized data structure. + +And it turns out that it is +data structure, + +you can do extract Min in order +log V amortized time. + +And remarkably, +you can do decreased key in + +order one amortized. +So, when I plug those in, + +what do I get over here? + +What's that going to be? +Plug that it here. + +It's going to be V times log V +plus E: E plus V log V. + +These are amortized, +so what's this? + +Trick question. +It's worst-case. + +It's not amortized over here. +These are amortized, + +but that's the beauty of +amortization. + +I can say it's going to be +worst case: E plus V log V over + +here, because when I add up the +amortized cost of my operations, + +it's an upper bound on the true +costs. + +OK, so that's why I say, +one of the beauties of this + +amortized analysis, +and in particular, + +being able to assign different +costs to different operations is + +I can just add them up and I get +my worst-case costs. + +So this is already V log V. +There are a couple other + +algorithms just before I let you +go. + +Kruskal's Algorithm in the book +uses another amortized data + +structure called a disjoint set +data structure, + +which also runs in E log V, +that is, this time: + +runs in this time, +the same as using a binary + +heap. +So, I'll refer you to the book. + +The best algorithm to date with +this problem is done by our own + +David Karger on the faculty here +with one of our former + +graduates, Phil Kline, +who is now a professor at + +Brown, and Robert Tarjan, +who is sort of like the master + +of all data structures who was a +professor at Princeton in 1993. + +OK, it's a randomized +algorithm, and it gives you + +order V plus E expected time. +OK, so that's the best to date. + +It's still open as to whether +there is a deterministic, + +there is worst-case bound, +whether there is a worst-case + +bound that is linear time. +OK, but there is a randomized + +to linear time, +and otherwise, + +this is essentially the best +bound without additional + +assumptions. +OK, very cool stuff. + +Next, we're going to see a lot +of these ideas of greedy and + +dynamic programming in practice. \ No newline at end of file diff --git a/FYJJHMLv9oM.txt b/FYJJHMLv9oM.txt new file mode 100644 index 0000000000000000000000000000000000000000..2c81bd46a6affbedba0c87ab949d015ff4a50993 --- /dev/null +++ b/FYJJHMLv9oM.txt @@ -0,0 +1,812 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +Hi there. + +I'm Brian. + +We're going to be doing problem +number 7 of the 2009 + +final examination. + +So the way I like to approach +these problems is to identify + +what I think is important to +know before attempting them. + +Things that you should review +that will help you + +successfully navigate +the problem. + +I call this the what +I need, W I N. + +So for this particular problem, +which I think of as + +the phase diagram problem, you +need three things critically + +in order to successfully +complete it. + +Number one you need to have a +general understanding of what + +a phase diagram is, how to read +it, how to write it, how + +to interpret the information +it gives you. + +You can find a lot of this in +chapter 9 of Shackleford. + +Along the same lines you should +probably know how to go + +in between binary and unary +phase diagrams. How they are + +related at least. In this +problem it's not absolutely + +necessary to know this. + +But in similar problems we might +ask, this is critical to + +understand how these two +are interrelated. + +The second thing you should +know is some language like + +critical point and +triple point. + +Where these are and what they +mean on the phase diagram. + +And the third thing is the +phase coexistence. + +So what does that +actually mean? + +How do you find it on +the phase diagram? + +So with these three particular +points, I'd review them and + +then I would recommend +attempting the problem + +afterwards. + +So we're going to start +the problem. + +We're going to start +over here. + +I'm actually going to start this +from a reverse direction. + +And review really quick what +a binary phase diagram is. + +because this is actually the +phase diagram which you will + +see most often as you progress +in your career as a scientist + +or an engineer. + +This is something you'll +see a lot of the time. + +It'll have either one element +and another element. + +Or one compound and another +compound along the axis. + +And it shows the different +phases which exist at certain + +temperatures and compositions. + +So in general it's important +to sort of understand + +what a phase is. + +So a phase, is a chemically and +a structurally homogeneous + +material given certain +state conditions. + +So a phase diagram depicts +picks all these phases. + +It's the master plot of phases +that are in equilibrium given + +a particular set of +state conditions. + +When I say state conditions +I'm actually referring to + +things like temperature, +pressure, I even sometimes + +consider composition to be one +of those state conditions. + +So in a binary phase diagram, +what we're looking at is the + +temperature versus +the composition. + +So if you have some composition +of silicon and + +germanium at some temperature, +you know exactly what phase it + +should be at thermodynamically. + +It doesn't actually mean it +will be, but it should be. + +So that's what a binary phase +diagram looks like. + +So this is something you'll +see a lot and this is + +something you probably will +become used to seeing a lot as + +you go on in your years. + +We're going to come back +to this in a second. + +But first, for now, we're going +to it actually attempt + +the problem that's given. + +And then I'll tie both of +those together for you. + +So let's go over and +let's actually look + +at the problem now. + +We'll go back to that +in a second. + +We're asked to draw a unary +phase diagram for silicon. + +And we're given some critical +information. + +Specifically on the problem +we're given the triple point, + +we're given the critical +point, and we're + +asked to draw this. + +Not to scale, of course, +but what it should + +generally look like. + +So the first thing I do +is label my axes. + +Pressure, temperature. + +And then we're given +certain data. + +So I'm just going to throw it +down right in the beginning. + +We're given pressure and +temperature for triple point. + +We're given pressure +and temperature for + +the critical point. + +So I'm going to put those +points down right now. + +Because I know that's +part of the answer. + +So let me first put down +the triple point. + +We're told the triple point +occurs at 0.15 atm. + +And we're told that that is at a +temperature of 1415 celsius. + +So temperatures are going +to be in celsius and our + +pressures are going to +be in atmospheres. + +So we're going to go up +to find this point. + +In fact I'm going to give +it a different color. + +That is our triple point. + +I'm next going to plot the +critical point here. + +We're told that that occurs +at a pressure of 6,600. + +So not to scale of course. + +But that's going to be somewhere +all the way up here. + +Now we're told that that is +at a temperature of 4880. + +So here's a point here. + +So we've just put +two points down. + +But that's not enough to +complete the problem. + +It doesn't actually answer +all the questions. + +The problem actually also asks +us to provide the normal + +boiling point and the normal +melting point of silicon. + +So you're not actually given +those temperatures because + +you've got to be clever. + +And all the students in our +class are given a periodic + +table during the exam. + +So I would encourage you to +have a periodic table with + +this type of data. + +So if you look at the periodic +table for silicon you can then + +find your melting point +and you can find + +your boiling point. + +So this data, a normal melting +point and a normal boiling + +point will occur at +1 atmosphere. + +Let me just put 1 atmosphere +on the pressure here. + +Again not to scale. + +So anything that occurs at this +particular pressure, this + +isobaric line, is going +to be normal. + +So our normal melting point +occurs at 1414, which is right + +next to 1415. + +There we go. + +And our normal boiling +point occurs at 3265. + +These are approximate numbers. + +So we'll put that here. + +And now if you've seen a unary +phase diagram before, which I + +hope you have during your +studying, you'll know that it + +looks somewhat like a y shape. + +So one thing we're going to do +now is we're going to connect + +these dots. + +We know that at very high +temperatures we're going to + +have what's a gas, basically. + +And at very low temperatures +we're going to have something + +like a solid. + +And we have some liquid +in the middle. + +And the way we're going to +delineate these phases is to + +connect these dots. + +And this is what our unary +phase diagram is + +going to look like. + +So in order to complete this +problem-- it was actually not + +too bad of a problem-- all you +have to do is label some + +particular aspects +of this graph. + +So number 1, we have a solid +region, we have a gas region. + +That implies this must +be the liquid region. + +I'll put an L there. + +You're asked to identify 1, +2 and 3 component regions. + +Or three 1-phase regions, +2-phase regions. + +So number 1, you could have +chosen for a 1-phase region, + +you can chosen a point here in +the gas, a point here in the + +liquid, or a point here +in the solid. + +I'll just choose +one in the gas. + +So something here, let's call +that i, for answering part i. + +You could have chosen a point +along any of these lines for a + +2-phase equilibrium. + +Which implies that at that +point, so at that specific + +pressure and at that specific +temperature, you have both + +phases of equilibrium. + +Let me just choose one +and explain it. + +So let's choose something +here. + +Between 0.15 and 1. + +So let's choose this point. + +There we are. + +So at this point, at whatever +pressure we're at and whatever + +temperature we're at here, we +have both liquid and gas in + +equilibrium. + +They both coexist. You're +not tending + +towards one or the other. + +They're both there. + +So that's part B, the 2-phase +coexistence area. + +So we put that here. + +i i. + +And the third part +is the 3-phase + +coexistence, which is-- + +almost you can pull it out of +the name-- the triple point. + +At the triple point-- and +there's only one of these-- + +you have all three, +gas, liquid and + +solid coexisting together. + +So we've already sort +of made that. + +That was our blue dot. + +1, 2, 3. + +That's that point right there. + +So not to scale. + +But this is the answer. + +This is full credit. + +One thing that's really +interesting to note is that on + +this particular answer we have +a negative slope on our + +solid-liquid coexistence line. + +Now you've probably seen this +before in your studying and it + +occurred with water. + +Most materials actually will +have a positive slope. + +If you think about it it's +sort of counterintuitive. + +What this implies is that if I'm +at a constant temperature + +and as I raise my pressure I'm +going to go from the solid to + +the liquid. + +Intuitively, we would think that +the solid is more densely + +packed and therefore as we +increase the pressure we're + +going to tend towards a solid. + +That's not the case in water and +in this problem is not the + +case with the data we're +given for silicon. + +In this case as we raise the +pressure we're actually + +turning into a liquid. + +It's kind of counterintuitive. + +Another way of actually saying +that is the liquid phase at + +this particular temperature +is more dense + +than the solid phase. + +And you see that with water, +which is why ice + +floats on top of water. + +So that is our unary diagram. + +That is the full credit +on this problem. + +I do want to tie it in really +quick though, with what a + +binary diagram is. + +Because this is a very important +concept to get and a + +potential problem. + +So we're going to go back +over to binary phase + +diagram over here. + +And so what we're looking at on +this binary phase diagram + +is actually, it's the +temperature versus the + +composition at a specific +pressure. + +Now for a binary phase diagram +you're going to assume-- + +unless you're told otherwise-- + +that it occurs at 1 +atm, 1 atmosphere. + +If I want to go between the +binary and the unary that we + +just looked at, you need +to add your third axis. + +So if we had a third axis-- + +let me draw that here. + +This is going to +be our z-axis. + +There's the z. + +We know that if we put a +pressure along this axis, + +we're going to be able to +extract what we had for our + +unary diagram. + +So let me do that for you. + +I'm going to call this +the pressure axis. + +Going back in and out +of the board. + +And actually this is at 1 atm. + +Which implies at some +point farther + +back we have the origin. + +You can just do this +lightly so it + +doesn't get too confusing. + +We have an origin for +our pressure. + +So at this point we +have 0 pressure. + +We don't work with negative +pressures. + +0 pressure. + +Which implies-- let me just +draw the Cartesian form of + +this-- so we have composition, +we have + +temperature, we have pressure. + +That's our x, y, z. + +Now what happens is that as we +increase pressure what happens + +to, for example, this point? + +Now what is this point? + +This point is the point +where we go from the + +solid to the liquid. + +That's the melting point. + +What happens to the melting +point as we increase or + +decrease our pressure? + +Well that information is given +on our unary phase diagram. + +Let's go back really quickly. + +As we increase our pressure we +can see that what's going to + +happen with our point is +it's going to go up. + +So what basically we have to +do is we need to take-- you + +have to think +three-dimensionally-- + +and take this graph and you're +going to take it an spin it + +and put it on to one of +those planes there. + +So we're going to get an idea. + +This is something that I would +challenge you, the listener, + +to do and think about and do +on your paper after you've + +completed this problem +successfully. + +I'm going to draw +it right now. + +And I'm going to let you +look at it and think + +about it, what it means. + +So let me do that. + +Let's take a look now. + +This is our temperature axis. + +Here's t. + +Here's p. + +Remember unary was p versus +t, so you've got + +to do a little flipping. + +But let me just draw it now. + +It kind of goes up +to the words. + +But you get the idea. + +This is-- if you do a little +flipping and I challenge you + +to do that, some +three-dimensional thinking-- + +this is the unary phase plot +that we gave for our answer. + +And the point I'm trying to +make is that you can go in + +between your unary and your +binary diagrams by + +understanding that. + +For example, binary diagram is +at a constant pressure and + +your unary diagram, unary +means that it has one + +material, one composition. + +So in this particular problem +I've created germanium to be + +our b element. + +And we're operating here +with pure silicon. + +So you can go in between +if you have the + +grasp of that concept. + +So I would challenge you +to think about that. + +If you've gotten the problem +right and you understand this + +concept, I think you're good +to go on phase diagrams. \ No newline at end of file diff --git a/FtIdQUcZlWU.txt b/FtIdQUcZlWU.txt new file mode 100644 index 0000000000000000000000000000000000000000..37e36959889b7dc80fb83d0993b01a4c1223a194 --- /dev/null +++ b/FtIdQUcZlWU.txt @@ -0,0 +1,736 @@ +align:start position:0% + +for these heritage learners i say + + align:start position:0% +for these heritage learners i say + + + align:start position:0% +for these heritage learners i say + + align:start position:0% + + + align:start position:0% +the students the heritage learner in + + align:start position:0% +the students the heritage learner in + + + align:start position:0% +the students the heritage learner in +this course + + align:start position:0% +this course + + + align:start position:0% +this course +they started unevenly so it's really + + align:start position:0% +they started unevenly so it's really + + + align:start position:0% +they started unevenly so it's really +hard to + + align:start position:0% +hard to + + + align:start position:0% +hard to +assess + + align:start position:0% +assess + + + align:start position:0% +assess +um you know how much progress i can only + + align:start position:0% +um you know how much progress i can only + + + align:start position:0% +um you know how much progress i can only +say progress because i have a goal in my + + align:start position:0% +say progress because i have a goal in my + + + align:start position:0% +say progress because i have a goal in my +mind what do they need to + + align:start position:0% +mind what do they need to + + + align:start position:0% +mind what do they need to +reach at the end of the course but how + + align:start position:0% +reach at the end of the course but how + + + align:start position:0% +reach at the end of the course but how +to how do i assess their progress as a + + align:start position:0% +to how do i assess their progress as a + + + align:start position:0% +to how do i assess their progress as a +problem because some will start really + + align:start position:0% +problem because some will start really + + + align:start position:0% +problem because some will start really +higher + + align:start position:0% +higher + + + align:start position:0% +higher +level than others so easier for me to + + align:start position:0% +level than others so easier for me to + + + align:start position:0% +level than others so easier for me to +see the progress in the lower level + + align:start position:0% +see the progress in the lower level + + + align:start position:0% +see the progress in the lower level +students harder for me to see the higher + + align:start position:0% +students harder for me to see the higher + + + align:start position:0% +students harder for me to see the higher +level so for me um the way i assess is + + align:start position:0% +level so for me um the way i assess is + + + align:start position:0% +level so for me um the way i assess is +because i do have a lot of writing aside + + align:start position:0% +because i do have a lot of writing aside + + + align:start position:0% +because i do have a lot of writing aside +assignment + + align:start position:0% +assignment + + + align:start position:0% +assignment +so + + align:start position:0% +so + + + align:start position:0% +so +i will see how much + + align:start position:0% +i will see how much + + + align:start position:0% +i will see how much +within the assignment + + align:start position:0% +within the assignment + + + align:start position:0% +within the assignment +how + + align:start position:0% +how + + + align:start position:0% +how +many new vocabulary are willing to use + + align:start position:0% +many new vocabulary are willing to use + + + align:start position:0% +many new vocabulary are willing to use +because as i said they like to stay in + + align:start position:0% +because as i said they like to stay in + + + align:start position:0% +because as i said they like to stay in +their comfort zone they like to use + + align:start position:0% +their comfort zone they like to use + + + align:start position:0% +their comfort zone they like to use +simple language they know + + align:start position:0% +simple language they know + + + align:start position:0% +simple language they know +it's correct + + align:start position:0% +it's correct + + + align:start position:0% +it's correct +they don't want to venture out because + + align:start position:0% +they don't want to venture out because + + + align:start position:0% +they don't want to venture out because +they're afraid to make mistakes + + align:start position:0% +they're afraid to make mistakes + + + align:start position:0% +they're afraid to make mistakes +so my assessment usually is + + align:start position:0% +so my assessment usually is + + + align:start position:0% +so my assessment usually is +how sophisticated they can be + + align:start position:0% +how sophisticated they can be + + + align:start position:0% +how sophisticated they can be +when they're doing the writing because + + align:start position:0% +when they're doing the writing because + + + align:start position:0% +when they're doing the writing because +we have a set of a vocabulary for each + + align:start position:0% +we have a set of a vocabulary for each + + + align:start position:0% +we have a set of a vocabulary for each +lesson and they're supposed to use it + + align:start position:0% +lesson and they're supposed to use it + + + align:start position:0% +lesson and they're supposed to use it +and for me + + align:start position:0% +and for me + + + align:start position:0% +and for me +because they are at a assumed at the + + align:start position:0% +because they are at a assumed at the + + + align:start position:0% +because they are at a assumed at the +stage they're still trying to memorize + + align:start position:0% +stage they're still trying to memorize + + + align:start position:0% +stage they're still trying to memorize +all the characters try to write a basic + + align:start position:0% +all the characters try to write a basic + + + align:start position:0% +all the characters try to write a basic +sentence + + align:start position:0% +sentence + + + align:start position:0% +sentence +so + + align:start position:0% +so + + + align:start position:0% +so +the the + + align:start position:0% +the the + + + align:start position:0% +the the +the composition i don't ask too much + + align:start position:0% +the composition i don't ask too much + + + align:start position:0% +the composition i don't ask too much +uh the structure as long as they can + + align:start position:0% +uh the structure as long as they can + + + align:start position:0% +uh the structure as long as they can +write the sentence down it's the basic + + align:start position:0% +write the sentence down it's the basic + + + align:start position:0% +write the sentence down it's the basic +grammar is correct that's fine but the + + align:start position:0% +grammar is correct that's fine but the + + + align:start position:0% +grammar is correct that's fine but the +vocabulary they can use + + align:start position:0% +vocabulary they can use + + + align:start position:0% +vocabulary they can use +so and these vocabulary sometimes in the + + align:start position:0% +so and these vocabulary sometimes in the + + + align:start position:0% +so and these vocabulary sometimes in the +course i would i would + + align:start position:0% +course i would i would + + + align:start position:0% +course i would i would +spend some time explaining i don't teach + + align:start position:0% +spend some time explaining i don't teach + + + align:start position:0% +spend some time explaining i don't teach +them how to read this vocabulary but i + + align:start position:0% +them how to read this vocabulary but i + + + align:start position:0% +them how to read this vocabulary but i +do correct their pronunciation i do tell + + align:start position:0% +do correct their pronunciation i do tell + + + align:start position:0% +do correct their pronunciation i do tell +them + + align:start position:0% +them + + + align:start position:0% +them +how to use these vocabulary because some + + align:start position:0% +how to use these vocabulary because some + + + align:start position:0% +how to use these vocabulary because some +vocabulary they give you english + + align:start position:0% +vocabulary they give you english + + + align:start position:0% +vocabulary they give you english +definition but actually it doesn't use + + align:start position:0% +definition but actually it doesn't use + + + align:start position:0% +definition but actually it doesn't use +that way in chinese at all yes this is + + align:start position:0% +that way in chinese at all yes this is + + + align:start position:0% +that way in chinese at all yes this is +what it means but you don't use the same + + align:start position:0% +what it means but you don't use the same + + + align:start position:0% +what it means but you don't use the same +context in chinese i will teach them + + align:start position:0% +context in chinese i will teach them + + + align:start position:0% +context in chinese i will teach them +the differences that's what i talk about + + align:start position:0% +the differences that's what i talk about + + + align:start position:0% +the differences that's what i talk about +and i will see some students really want + + align:start position:0% +and i will see some students really want + + + align:start position:0% +and i will see some students really want +to + + align:start position:0% +to + + + align:start position:0% +to +you know expand their vocabulary then i + + align:start position:0% +you know expand their vocabulary then i + + + align:start position:0% +you know expand their vocabulary then i +would you know i would know he's trying + + align:start position:0% +would you know i would know he's trying + + + align:start position:0% +would you know i would know he's trying +that's how i assess the progress we do + + align:start position:0% +that's how i assess the progress we do + + + align:start position:0% +that's how i assess the progress we do +have a lot of quizzes we do have a lot + + align:start position:0% +have a lot of quizzes we do have a lot + + + align:start position:0% +have a lot of quizzes we do have a lot +of tests we do have a lot of speaking we + + align:start position:0% +of tests we do have a lot of speaking we + + + align:start position:0% +of tests we do have a lot of speaking we +do a lot of + + align:start position:0% +do a lot of + + + align:start position:0% +do a lot of +you know individual report and the group + + align:start position:0% +you know individual report and the group + + + align:start position:0% +you know individual report and the group +project in the classroom so all these i + + align:start position:0% +project in the classroom so all these i + + + align:start position:0% +project in the classroom so all these i +you know i look at it holistically + + align:start position:0% +you know i look at it holistically + + + align:start position:0% +you know i look at it holistically +yeah yeah i i'm still thinking about a + + align:start position:0% +yeah yeah i i'm still thinking about a + + + align:start position:0% +yeah yeah i i'm still thinking about a +more effective way to assess them + + align:start position:0% +more effective way to assess them + + + align:start position:0% +more effective way to assess them +especially i want the student to do + + align:start position:0% +especially i want the student to do + + + align:start position:0% +especially i want the student to do +the self-assessment that's important + + align:start position:0% +the self-assessment that's important + + + align:start position:0% +the self-assessment that's important +that um they call it um + + align:start position:0% +that um they call it um + + + align:start position:0% +that um they call it um +what's that word anyway making a + + align:start position:0% +what's that word anyway making a + + + align:start position:0% +what's that word anyway making a +portfolio for yourself what you can do + + align:start position:0% +portfolio for yourself what you can do + + + align:start position:0% +portfolio for yourself what you can do +what you cannot do that kind of thing um + + align:start position:0% +what you cannot do that kind of thing um + + + align:start position:0% +what you cannot do that kind of thing um +i start giving them questionaries but i + + align:start position:0% +i start giving them questionaries but i + + + align:start position:0% +i start giving them questionaries but i +want to develop more and to the last + + align:start position:0% +want to develop more and to the last + + + align:start position:0% +want to develop more and to the last +turn i did it but you know what can i do + + align:start position:0% +turn i did it but you know what can i do + + + align:start position:0% +turn i did it but you know what can i do +now what i know now those are good but + + align:start position:0% +now what i know now those are good but + + + align:start position:0% +now what i know now those are good but +that's still very vague you have the + + align:start position:0% +that's still very vague you have the + + + align:start position:0% +that's still very vague you have the +right you have to ask the right + + align:start position:0% +right you have to ask the right + + + align:start position:0% +right you have to ask the right +questions you know sometimes it's all + + align:start position:0% +questions you know sometimes it's all + + + align:start position:0% +questions you know sometimes it's all +about asking right question because some + + align:start position:0% +about asking right question because some + + + align:start position:0% +about asking right question because some +question could be they can answer really + + align:start position:0% +question could be they can answer really + + + align:start position:0% +question could be they can answer really +vaguely yes i know but how much you + + align:start position:0% +vaguely yes i know but how much you + + + align:start position:0% +vaguely yes i know but how much you +really know right so that's that's a big + + align:start position:0% +really know right so that's that's a big + + + align:start position:0% +really know right so that's that's a big +topic i'm still + + align:start position:0% +topic i'm still + + + align:start position:0% +topic i'm still +working on that \ No newline at end of file diff --git a/GdHqomimt8c.txt b/GdHqomimt8c.txt new file mode 100644 index 0000000000000000000000000000000000000000..edf7d2f2f5eca540904886752922155ec4d55f8b --- /dev/null +++ b/GdHqomimt8c.txt @@ -0,0 +1,4213 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality, educational + +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: So where we left it +last time is the access to + +family planning, the access to +contraception, et cetera, did + +not play such an important +role in keeping people's + +families small. + +It doesn't mean that it's +not a good thing to do. + +It certainly helps people +time their fertility. + +It makes them happier and all +other good things, but it was + +not the main determinant +of family size. + +And so then the next question, +obviously, is then what is the + +determinant of family size? + +If people are not constrained +by their lack of access to + +contraception to choose the +family size that they want, + +how do they decide to choose +their family size? + +And there are, I think, only +two big classes of factors + +that might matter. + +One is social factors, so both +what the community thinks is + +right, what the country thinks +is right, what your husband + +thinks is right. + +And the other is the cost and +benefits of having sex, which + +is pleasant, and having babies, +which you might or + +might not want to have at a +specific time of your life. + +So both of these things are +traded off in some ways. + +And the issue is whether people +do that effectively, + +whether they do that +voluntarily, whether there is + +some correction coming +from society or + +something like that. + +So social norms clearly +play a role. + +So one example is this example +of Matlab, in Bangladesh, + +where this program was +introduced, and a community + +worker came and tried +to persuade woman. + +One thing that has happened is +that, at the beginning of the + +program, the introduction +was very, very slow. + +The take-up of contraception +was very, very slow. + +And then it started to explode, +the take-up started + +to explode. + +And then it comes down again. + +So you get a little bit of an +s-shape in adoption of the + +contraception. + +And what kind of mechanism would +explain, what kind of + +social mechanism explains this +kind of diffusion curve? + +You must have seen that, either +in other classes or you + +can think about it. + +AUDIENCE: Viruses. + +PROFESSOR: Exactly. + +This is how viruses spread. + +This is also how iPads spread +or any new innovation. + +And why does it spread +in this way? + +Why does it have this shape? + +AUDIENCE: If it's contagious, +initially, then a smaller + +group of people haven't. + +I guess that people that +interact with each other at + +some point. + +I mean it kind of depends +on something, I + +don't exactly know. + +I don't know the exact +mechanism. + +PROFESSOR: Right. + +But you get the drift. + +It spreads mostly like viruses +or new products, which spread + +mostly by infection. + +At the beginning, no one is +infected, so the innovation or + +the virus doesn't spread. + +And then more and more +people get infected. + +So they get chances to +infect more people. + +So there is a sudden take off. + +And then after a while, +everybody is infected. + +So the infection has nowhere +to go anymore. + +So that's why we find this kind +of mechanism, both for + +viruses and for new things. + +So the fact that in Matlab the +contraception had the same + +spread, at first very slow and +then a sudden take off and + +then flattening out again, when +the take-up was larger, + +suggests there may have been a +contagion phenomenon going on. + +So to look at it more directly, +there's a paper by + +Kaivan Munshi, who looked at +what happened, whether people + +do the same thing that +their neighbors do. + +And so the first thing you can +do is to say, well, if there + +are 20 women in my neighborhood +and 19 have + +adopted the contraception, am I +more likely to adopt then if + +there is 0 who have adopted? + +And when you do that, you find +that indeed people, who had + +more people who adopted +around them, were also + +more likely to adopt. + +So is that necessarily a sign +that they're learning from + +each other? + +What else could be going on? + +AUDIENCE: It could just +be a copycat effect. + +So it's not necessarily that +you're learning, but you're + +just doing as you see +someone else do. + +PROFESSOR: Exactly. + +So the learning could +in a broad sense. + +First, it doesn't have to +be learning something. + +It could just be pure imitation, +where you're trying + +to figure out what's the +fashionable thing to do. + +So there is no learning +going on. + +That's right. + +So this is going to be difficult +to separate, but + +even beyond that? + +Yeah? + +AUDIENCE: I guess if more people +around you are doing + +it, there is greater +demand in the area. + +[INAUDIBLE] + +supplies, but it's just +inaccessible. + +PROFESSOR: Right. + +So there might be this effect, +which is it might be that, in + +response to the first demand +from the people, there is an + +excess in supply. + +Or it could even be that it +turns out that the community + +health worker is better in +that particular village. + +And so, because she's better +and more energetic, she got + +your neighbors to adopt and, +also, yourself to adopt. + +And the fact that you adopt when +you neighbor adopts is + +not a sign that there is a +causal effect of neighbor's + +adoption on your, which could +be coming from copycat or + +coming from learning, but just +that there is one common + +factor that leads them to adopt +and leads you to adopt. + +So what he does is that he does +something very ingenious. + +He exploits the fact that most +of these villages have Hindus + +and Muslims. + +And there is only one community +health worker for + +both communities. + +But Hindus don't speak +to Muslims-- + +certainly not about +contraception. + +And Muslims don't +speak to Hindus. + +So now he's looking at, if it +was the certain hypothesis + +that the reason why our actions +are correlated is + +because of the community +health worker. + +Should I see that, if I'm a +Muslim woman, there is also a + +correlation between my adoption +and that of the Hindu + +woman if it's due to the +community health worker. + +AUDIENCE: Can you restate +the question? + +PROFESSOR: So if it is due to +the community health worker, + +should I see a relationship +between the adoption of the + +Muslim woman and the adoption +of Hindu woman? + +AUDIENCE: Yes. + +PROFESSOR: Yes. + +If it is due to the community +health worker, because she's + +serving both communities, we +should see this correlation. + +Sorry, one more came. + +Thank you. + +Good effort. + +But if it is due to the social +learning, should we see a + +relationship between the +adoption of the Hindu woman + +and adoption of the +Muslim woman? + +No. + +So if it's due to the people +learning from each other or + +even copying each other, they +can't copy the Muslims, + +because they never will ask +them if they are Hindu and + +vice versa. + +So he does that. + +And what he finds is that the +correlation is only within + +community, which is an +indication that, probably, + +people are trying to figure +out what's the social norm + +around the social group or +are copying each other. + +And it's just not a joint +effect of the + +community health worker. + +Another way in which you would +peak at the social norm is by + +watching what's on TV. + +And there is a very nice paper +on the telenovelas in Brazil. + +So Brazil is a very Catholic +country and, until relatively + +recently, was not a very free +society, until about + +15, 20 years ago. + +And it was certainly not +particularly encouraging + +family planning. + +But the telenovelas, which are +like soap operas, became very, + +very popular. + +And they became very popular, +in part, because they were + +quite good. + +And the reason why they +were quite good-- + +I'm told, because I'm yet to +watch one, my Portuguese being + +not quite up to crack-- + +is that a lot of people who +would otherwise have been + +artists in other fields could +not really do it very easily + +in Brazil, so they all went +and did telenovelas. + +And they were aired on one +channel, called Rede Globo, + +which was not available +everywhere at the beginning, + +which progressively spread. + +So what this article did is +that they looked at the + +diffusion of the Rede Globo all +over Brazil and compared + +the number of children that a +women had before and after the + +introduction of Rede Globo +in places where it got + +introduced. + +So exploiting, in that way, the +progressive introduction. + +Of course, the cities got +it first and then + +the more rural areas. + +So places that got it first, in + +general, had fewer children. + +But if we compare before and +after you get it, in places + +that get it and places that +don't, then we get a sense + +about what is the effect +of Rede Globo. + +And what they found is that +the women, who were of + +reproductive age after Rede +Globo was introduced, had + +fewer children in their lifetime +then the places that + +were in reproductive age +before Rede Globo came. + +And another thing that was kind +of cute, as a result of + +that, is that many of the kids +that were born in this area + +were born after the characters +of the telenovelas. + +Yeah? + +AUDIENCE: [INAUDIBLE] + +these telenovelas, the main +characters have few children? + +PROFESSOR: Yes. + +Exactly. + +The reason why this happened is +that the telenovelas were + +promoting, not necessarily for +the sake of it, but the main + +characters in the telenovelas +were people, some of them with + +0 children, if they had +children, with a small family. + +So they were promoting a model +of like a modern woman who had + +few children, which kind of +helped or contributed to + +slowly shift the norm. + +Yes, Brazil expertise. + +AUDIENCE: So it was is like +the main channel. + +Like if there is one that people +actually don't have to + +pay, necessarily, for it, you +just get it for free, if you + +just have a TV So part of the +access to that channel comes + +with some areas that are growing +into big cities, + +becoming a little bit +more industrialized. + +So that could be another +thing, stuff like that. + +People are getting access to +the TV channel, that means + +that the country as a whole +is becoming more and more + +industrialized. + +And they are sort of adapting +how many kids they have to fit + +the model a little bit better. + +PROFESSOR: Right. + +AUDIENCE: So the actual cause +could be different. + +Maybe it's not just the fact +that they were watching TV, + +but the fact that they +gained access to it + +and what that implies. + +PROFESSOR: So what you are +saying is that TV came on the + +tail of other changes +in the same areas? + +AUDIENCE: Right. + +Some places becoming a +little bit more urban + +and how that's changed. + +PROFESSOR: Yeah. + +So that's a very good point, +which is always with this + +different and difference +kind of strategy. + +The always are worried +about that. + +At least we are not comparing +directly the city to the rural + +areas, but we are comparing the +rural areas as they are + +becoming industrial enough +or developed + +enough to get the channel. + +Because, presumably, the channel +decided to come when + +there was enough people who +were rich enough to buy a + +television. + +And therefore, they may have +been looking, not only at the + +level of development of the +place, but how it was moving. + +And if that is the case, then +we could be picking part of + +those trends. + +So that is something where we +could never be completely + +sure, because we haven't +randomized. + +So those underlying trends, +we don't observe them. + +And so it's quite possible +that you are right. + +So these doubts remain. + +What the author does is try to +look at whether there are + +trends in fertility before, that +the fertility was already + +a little bit declining before +the channel came in. + +Which we would probably observe, +if the stories you're + +talking about is the one, which +is, as I see that the + +place is becoming more +industrialized, richer et + +cetera, I'm putting the TV +there, as the president of + +Rede Globo. + +And they don't see that. + +They see kind of shift in trend +around the introduction + +of the television. + +But you might be +entirely right. + +That's also why I like the first +name thing, that the + +kids were named after the +people in the series. + +Because that is less likely +to becoming from + +industrialization in general and +more likely to be coming + +from the fact that +you've seen them. + +But that's very well taken. + +AUDIENCE: Did they +observe a lag? + +Like the introduction of the +TV show and the shift in + +[INAUDIBLE]. + +PROFESSOR: Right. + +Exactly. + +So that's exactly what +they are exploiting. + +They are trying to look at, +particularly, it doesn't + +reduce the fertility of people +who were already past their + +prime fertile age when +the TV came. + +It reduces only the fertility +of women who were in their + +late teens and then early 20s +when the TV came, and whose + +views were shaped by this. + +And this is exactly this timing +that helps, to some + +extent, discriminate between +the idea that the TV caused + +the reduction of the fertility +and your perfectly legitimate + +point that, in fact, in part +it could also be that TV is + +just a proxy for the social +progress happening. + +So these are all indications +that something, which is + +probably not particularly +surprising, is in something as + +fundamental and deep +as how many + +children you want to have. + +The social norms around you-- + +these are very local, your +village, your community, your + +family, your mother-in-law, +or society as a whole, as + +reflected to you by TV-- + +matter. + +But there are also just plain, +simple, cost-benefit + +calculations about do I want a +kid at this time, do I want to + +take the risk of a kid at this +time by having unprotected + +sex, et cetera, et cetera. + +And one thing that I want to +argue is that people are very + +good at making those +calculations. + +And in the sense the key group +to look at for a test case of + +this are adolescent girls. + +Because in these countries and +elsewhere, we kind of suspect + +adolescent girls to be not +the best at making those + +calculations, necessarily, +which is why we see some + +teenage pregnancies. + +And so if they can calculate, +then it would mean that, + +presumably, people can +calculate them. + +Another reason why it's very +interesting to look at + +adolescents, in particular, in +Africa, is not only teenage + +pregnancy, but teenage pregnancy +as a sign that + +you've had unprotected sex, +which puts you at risk for a + +STDs, sexually transmitted +diseases, in particular, HIV. + +So adolescents have been called +the window of hope in + +the fight against HIV, because +A, they are uninfected. + +And once you're infected with +HIV, you're infected. + +You can't disinfect the people, +so it's better to + +catch them early. + +Second-- + +and that goes back to the point +that you made earlier + +about was there a lag-- + +people's sexual preferences, +their habits, et cetera, have + +not yet been formed. + +And maybe it's right time to +catch them to influence their + +behavior early, and then they'll +keep those patterns + +for the rest of their life. + +So there is a lot of effort, +the world over, to develop + +programs to try to teach kids +to have a safer sex life. + +And UNICEF worked on a lot +of these programs. + +But unfortunately, in a lot of +countries, there is some + +pressure to have this program +being mainly concerned about + +abstinence and faithfulness. + +So the strategy that is employed +in eastern South + +Africa is called ABCD. + +So the A is for abstain, B for +be faithful, C is for use a + +condom, and D is or you die. + +So that kind of encapsulates the +HIV prevention strategy. + +But in primary schools, and +primary school in Kenya goes + +till grade eight, and people +start school late + +and repeat a lot. + +So really, kids are like +16, 17, they're + +still in primary school. + +So think of primary +and junior high. + +There was a policy decision that +was made in Kenya, which + +is still a pretty religious +country, that condoms could + +not be discussed in school. + +So the ABCD program is really +an ABD program, + +abstain or be faithful. + +And, in fact, it's a program, +which is all day long, to + +scare kids away and to say, look +everybody's dangerous. + +HIV is everywhere. + +The most dangerous kid is the +kid you meet in a disco. + +I'm not making any of this up. + +I've read the little UNICEF +books, where you have this + +little cartoon of a girl going +to a disco and meeting this + +boy and having sex and +then getting HIV. + +So this is the type of thing +that they are trying to put + +into people's heads. + +So basically, the message +becomes, abstain until you are + +of age to get married and +then get married. + +Now the big danger with +that is that kids + +decide, well, fine. + +I don't want to die. + +But I don't want to abstain. + +So let me get married. + +And the reason why it's so +dangerous is that means that + +kids could get married early. + +For girls, it means they would +have children early. + +And so we would have very early +pregnancies, which means + +that they would interrupt their +schooling, which means + +that they would be, typically, +quite a bit younger than their + +husbands, which changes their +status in the family, as we + +are going to see in a +minute, et cetera. + +So we decided to try and test +the impact of the ABCD program + +against doing nothing and +against another strategy, + +which is to basically make it +a little bit easier for kids + +to stay in school. + +How do you make it +a bit easier for + +kids to stay in school? + +You just pay the cost of staying +in school, which now + +is just like the uniform. + +So we ran an experiment with +Pascaline Dupas and Michael + +Kremer, a pretty big experiment, +376 schools, which + +were assigned to one +of four groups. + +One was a control group. + +One was a uniform group. + +And the other thing we did is +we wanted to test the ABCD + +strategy, so we accelerated +the training of teachers. + +Because, in principle, every +school is supposed to + +experience the ABCD strategy, +but, in practice, the teachers + +are very shy about talking +about HIV. + +They don't want to be branded +as an HIV teacher. + +People are still pretty prudish +about the whole thing. + +So teachers won't do anything +about HIV AIDS prevention + +until they get training +to do it. + +So the government has +a team of trainers. + +And they went, and they +trained the people. + +And that way the teacher +started to teach. + +So we had four groups. + +One, the teachers got trained. + +One, the kids got +a free uniform. + +And in one group, +they got both. + +And these are some +of our girls. + +And then we followed the +kids, all the way, + +from 2002 to 2011. + +So what I'm going to show +you is really the + +results that are coming. + +The results are as +of yesterday. + +So you get like prime news. + +Not yesterday, because I had +the slides on two days ago, + +but like less than a week ago. + +And what do we find? + +So this are simple means. + +And I tell you what is +significant in the means and + +what's not. + +This is your probability to +complete primary school in the + +four groups. + +So what is not surprising +in this graph? + +Can you read? + +You have the control group, +uniform, teacher training, and + +then both is the uniform +and teacher training. + +So what is not particularly +surprising in this graph? + +AUDIENCE: They all exceed +the control group. + +PROFESSOR: That they all exceed +the control group. + +And, in particular? + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: Both exceed just +teacher training. + +And? + +AUDIENCE: That both +is-- oh, sorry. + +I was going to say what's +surprising. + +PROFESSOR: Yeah, what is +surprising is fine, too. + +AUDIENCE: It's the fact that +both is less than uniforms. + +PROFESSOR: Exactly. + +So what is not surprising is +uniform is much more than + +everybody else. + +In fact, control and teacher +training are + +pretty much the same. + +I mean, they are not +statistically different. + +Uniform is much more. + +I mean, you have to take care +of the scales, here. + +These are not huge effects. + +But getting a uniform, which +costs like a few dollars, + +really nothing, increased +completion rates of primary + +school by about 6%. + +What is surprising is that both +is less than uniform. + +You would think that it would +at least be just the same, + +because at least they +have a uniform. + +So why is both less +than uniform? + +Not to answer the question, we +are going to continue and see + +what else we're seeing in this +data and then come back to try + +and figure out what's +happening. + +That's a second thing which is +happening is whether or not + +you are ever pregnant +by age 17. + +It's like, if you're ever +pregnant or pregnant by age + +17, it will give you +the same result. + +So what is not surprising +here? + +We can just describe +the results. + +Yeah? + +AUDIENCE: The surprising part +is that teacher training is + +the highest. + +PROFESSOR: Yeah, so the quite +surprising part is that + +teacher training +is the highest. + +So remember, this is an +abstinence program. + +The abstinence program is +leading to a slight increase + +in the number of pregnancies. + +That is not the sign of +a successful program. + +Which is the program that seems +to be doing the best? + +AUDIENCE: Uniforms. + +PROFESSOR: The uniform +program is great. + +But what do we have, again, +that is surprising, here? + +That both is above. + +So not only the teacher training +does nothing, but it + +undoes some positive effect of +the uniform program, both in + +terms of school attendance and +in terms of teenage pregnancy. + +So now let's look at +the STD infection. + +So we tested for HIV. + +And we tested for HSV2. + +HSV2 is a form of herpes. + +It's less bad than HIV. + +It's not going to kill you. + +But it has the same +characteristic, which is once + +you have a biomarker for it in +your body, it never goes away. + +You have the antibody for it, so +we know that you've had it + +at some point in your life. + +It's also good to diagnose +it, because + +it needs to be treated. + +It's also bad to have HSV2, +because, as other sexually + +transmitted diseases, it greatly +increases the chance + +that you get HIV. + +The transmission rate of HIV, +if you have sex with an + +infected partner, is higher +if you have another STD. + +Because there are lesions +in your body that the + +virus uses to get in. + +So what do we find with HSV2? + +So the reason we don't use HIV +is that one of the great news + +of this project is +no one has HIV. + +We have about 1% of +HIV infection. + +So that's very, very low, +across all groups. + +So that's good. + +But there is much +more of HSV2. + +It's about 9% in the +control group. + +And here, what do we see, +with this graph? + +So that is the result that +is brand, brand new. + +The other results, +we already had. + +That's the reason that this +is completely new. + +AUDIENCE: If they had a uniform, +it makes you more + +likely to [INAUDIBLE]. + +PROFESSOR: Somewhat +more likely, yes. + +So you can call it the same, +that both uniform and teacher + +training don't help. + +Those are all pretty similar +in terms of standard error. + +But it doesn't help. + +So having a uniform makes you +stay in school longer. + +It makes you less likely +to a teenage pregnancy. + +But you're not less +likely to have + +sexually transmitted diseases. + +Teacher training, again, is +not doing anything good. + +And then what now makes a +difference is the both + +program, where, if you have +the two together, you're + +significantly less likely to +be infected with HSV2. + +So what do you think +is happening? + +Any kind of story you can try? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, but when +we wrote the book, + +I didn't know this. + +So you will have to +make one more. + +We can start with that, then +you can retell the + +story of the book. + +And then you can say why that +explains that as well. + +AUDIENCE: So my understanding +was that the uniforms kept the + +students in school. + +And as a result, they had less +time to do other things, like + +have sex, which could + +potentially give them diseases. + +So it makes sense to me why both +would be more effective + +in reducing how many people were +HSV2 positive, because + +you would be more likely to be +in school and then you'd be + +getting the training from the +teacher in respect what they + +should not be doing in +order to avoid that. + +PROFESSOR: So that +is possible. + +So Ben's idea is that, oh, you +spend more time school. + +And therefore, you have more +time to learn what the teacher + +is telling you. + +And therefore, that should +be the most effective. + +But if that was the story, we +should see all of them going + +down a little, and both going +down the most, right? + +So there is something else. + +Yeah? + +AUDIENCE: Because it has to +do with getting married. + +So it still kind of goes along +with school, where I think the + +people with the uniforms seem to +be able to stay in school. + +And so they don't +get pregnant. + +Because I assume the pregnancy +would come from + +when they get married. + +But they're probably, maybe +having safe sex. + +Or, I guess, unsafe sex. + +PROFESSOR: Unsafe sex, yeah. + +AUDIENCE: They're still having +sex, so they're still getting + +diseases, but they're not +getting pregnant and dropping + +out of school. + +Whereas with both, it may +be a category where + +they're getting married. + +And so now they only +have one partner. + +So they're less likely +to get diseases + +but not getting pregnant. + +PROFESSOR: Exactly. + +AUDIENCE: For this particular +result, are you tracking the + +students who actually dropped +out and got married? + +PROFESSOR: Yeah. + +We tracked everyone. + +That's why it took us forever +and something like $2 million. + +But we attempted to track all of +the cohort that was in the + +initial program. + +Of course, a lot of +them have moved. + +So if they went to Nairobi, +we went to + +Nairobi to look for them. + +If they went to Uganda, +we went to + +Uganda to look for them. + +So the first wave of them, we +managed to find about 60%. + +And then in the remaining 40% of +them, we really put all of + +the means to find them and +found about 80% of them. + +And so the effective tracking +rate was about 85%. + +And this has accounted +for that. + +So we have all the married +people, the ones that have + +dropped out, the ones that +didn't drop out. + +They're all here. + +So anybody wants to build +on the story? + +So the story that I think is +happening is something very + +similar to what you +are [INAUDIBLE]. + +Basically, you can have +two kinds of sex. + +You can have casual sex. + +And you can have sex with +a regular partner. + +And then you can choose whether +or not you want to use + +a condom or you don't want +to use a condom. + +So you can choose your +level of protection. + +Let's say you don't +like it so much. + +You should like it. + +But let's say, they don't +like it so much. + +And so there is some cost of +using more protection. + +But the advantage of condoms is +that you're less likely to + +get an STD, and you're less +likely to get pregnant. + +And then what people look at +is the cost and benefits of + +pregnancy, of a pregnancy +now, as a teenager. + +And the cost of an STD. + +There is no benefit +of getting an STD. + +And the probability that they +might get pregnant and the + +probability that they +might get an STD. + +And the cost and benefit of +pregnancy is the value of + +having the child. + +You might like to have a child +more if you have partner to + +have a child with then if you +have to raise them alone. + +So the value of a child in +marriage might be higher than + +the value of a child with +a casual partner. + +And then on the cost side is +foregone earnings, because if + +you have child, you have +to take of the child. + +They kick you out of +school anyway. + +You can absolutely not go to +school when you're pregnant. + +In fact, they just passed a law +saying that schools cannot + +evict children that +are pregnant. + +When this was happening, it was +the end of your schooling + +if you had a child. + +So the cost of the pregnancy is +that you're losing a chance + +to further your education +if you wanted to. + +So that's kind of the parameter +of what's happening. + +Now we have the girls, and +they are thinking, well. + +And of course, people like +to have sex, girls, too. + +So they are like weighing, +like, what should I do? + +How much sex should I have? + +Should I use contraception? + +And should I have a regular +partner that + +might lead to a marriage? + +Or should I have casual partners +that are not going to + +lead to marriage? + +And what the teacher training +program is telling them, if + +you have casual sex, you're +very, very, very + +likely to get an STD. + +It does change their probability +that they might + +get an STD. + +But if you have sex within +marriage, you're safe. + +You're fine. + +In fact, it might do the two +things at the same time. + +Maybe, girls have not realized +the difference between casual + +sex and married sex. + +But after the teacher training +program, they think married + +sex is very safe. + +And they think that casual +sex is very risky. + +And the truth is that married +sex is not necessarily that + +safe, because the candidate +for marriage, for a young + +girl, is usually not a young +boy, who would be unable to + +support a child. + +It's usually an older man, +what they call a "sugar + +daddy", who is able to provide +for the girl and then provide + +for the child. + +And the girls are convinced that +the "sugar daddies" are + +faithful to themselves +and their wives. + +But that might not +be entirely true. + +And so the actual risk of +infection in married sex and + +in casual sex might not +be that different. + +But when the teacher training +program arrived, they feel, + +oh, my god, I have to stop +having casual sex. + +That's very dangerous. + +Let me reduce, a little bit, +the sex I'm going to have. + +But let me also move towards +married sex. + +And by doing that, they're much +more likely to become + +pregnant, because, within +marriage, they think it's fine + +to have a kid. + +And also, they think that, +within marriage, they don't + +need to be protected as much. + +So for these two reasons, the +pregnancy rate will tend to + +increase if anything. + +On the other hand, they also +have less sex, so that + +balances out, which is why we +have a slight increase in the + +number of pregnancies, in the +teacher training group, + +instead of seeing a decrease. + +Because we see a reduction +in sex, but that's + +counterbalanced by a shift +towards this single + +relationship. + +And because the single +relationships are actually not + +that safe, we also don't see +much in terms of reduction in + +HSV2 infection. + +Now in the uniform group, +suddenly the cost of staying + +in school has become +much lower. + +So staying in school becomes an +option, something you can + +actually do. + +So then you feel, +OK, I'm going to + +try and stay in school. + +But then I really shouldn't +get pregnant. + +So you will move from married +sex to casual sex, use more + +contraception, both because you +don't want to have a kid + +and because you don't +want to be pregnant. + +And that's going to reduce. + +So you're going to +dropout less. + +You're going to have +fewer kids. + +Yep? + +AUDIENCE: Why does the teacher +training still have like a + +large percentage of kids +with HSV2 positives? + +PROFESSOR: Because the reality +is that married sex is not + +that less dangerous, +in terms of HSV + +infection, than casual sex. + +AUDIENCE: But you're saying +there's not a statistical + +difference between training +and both. + +PROFESSOR: Oh, there is. + +So teacher training +does nothing. + +So, oops. + +There is no difference +between teacher + +training and control group. + +That's because with teacher +training people switch towards + +married sex. + +And they think that's safe. + +But that's not really. + +Because they're having sex with +sugar daddies who are + +maybe themselves infected. + +So they do that, which is +why they have more kids. + +But they think that it's safe. + +But it's not safe, which +is why you get no. + +And then I'm going to talk +about both in a moment. + +So I've done teacher training. + +I've done uniform +and now both. + +Well, what is happening with +both is that, on the one hand, + +you think casual sex +is very dangerous. + +You want to avoid it. + +On the other hand, you don't +want to get pregnant. + +So married sex is not +great at all. + +So you can't substitute. + +The teacher training program +only pushes you towards one + +kind of sex. + +And therefore, so that +you don't have to + +reduce your sex so much. + +The uniform program pushes you +towards the other kind of sex. + +And you don't also reduce +your sex so much. + +But the both program, the can't +substitute, because + +neither of them are so +great as an option. + +So your only option is either +to reduce sex or to increase + +protection or both, which is why +we get the biggest effect + +on HSV2, but we don't get the +biggest effect on pregnancy. + +Because we don't have this +switch towards casual sex, + +which really doesn't have very +many pregnancies at all. + +So that, I think, is what is +going on, which is we get + +exactly these patterns +of results. + +Yeah? + +AUDIENCE: Sorry. + +So you're saying that you don't +see this as all with + +respect to pregnancy? + +You don't necessarily +have a shift + +towards casual sex there? + +PROFESSOR: So this is what +we have for pregnancy. + +For pregnancy, with the +both, they stay + +like at the same level. + +So you don't have +these big shift. + +You really have very few +pregnancies in casual + +relationships. + +AUDIENCE: Does that tell us +anything about which one, + +uniform or teacher training, +which is more [INAUDIBLE] + +to be more responsible to? + +PROFESSOR: So both of them, in +a sense, I think, teacher + +training, they were responsive +to both of them. + +But in the way that I just +described, in terms of their + +thinking about it. + +But in terms of the effect +you're trying to get, well, if + +you're interested in schooling +or in teenage pregnancy, + +asking people to stay in school +is the best thing. + +If you're interested in +preventing HIV/AIDS and other + +STDs, then you want to +add some training. + +That doesn't make if for a very, +very easy policy lesson, + +because that slightly depends +on you objective. + +But for a very fundamental +reason, which is it + +corresponds to the way people +decide and how they decide. + +So it seems the biggest policy +answer to that is that you + +shouldn't have programs that +are lying to people. + +It just doesn't help. + +So the way the program is +structured is to try and make + +the girls as scared as possible +of casual sex. + +But it would be a little bit +better to insist on helping + +them to find a way to protect +themselves, both against + +pregnancy and against HSV2. + +So I think that's kind of the +lesson that comes out of this. + +Yep? + +AUDIENCE: So along those lines, +how do these results + +reconcile with the fact that the +teacher training doesn't + +actually emphasize contraception +anymore, like + +safe sex at all? + +PROFESSOR: Yeah. + +These results are a direct +consequence of the fact that + +the teacher training doesn't +influence contraception. + +So they won't tell +you anything. + +It's not an evaluation of +teacher training in general. + +This is an evaluation of the way +it is done in Kenya and in + +most of East Africa, +which is explicitly + +ignoring the condoms. + +Yeah? + +AUDIENCE: Sorry. + +What I mean is like, in this +last finding, the argument + +goes that, if you have both +teacher training and uniforms, + +then people are more likely to +not be married but have safer + +casual sex. + +PROFESSOR: And fewer +sex in general. + +AUDIENCE: And have fewer +sexual partners. + +PROFESSOR: Less sex, also. + +Both things will happen +on this one. + +Because when you have just +teacher training, people have + +the option to switch towards +the married sex. + +When you just have the uniform, +people have the + +option to switch toward +the casual sex. + +But here, they don't have the +option to switch, because they + +are scared of married +sex, because + +they don't want children. + +And they're scared of casual +sex, because they + +don't want an STD. + +And they think the probability +is high with casual sex. + +So the only thing they can do, +because they can't substitute + +between these two activities, is +either to have less sex or + +to use more contraception. + +And the teacher training, +itself, is not teaching them + +about contraception. + +But they all know, at some +level, that it's available, + +and that it prevents +both pregnancy + +and STDs, to a point. + +So this doesn't tell us you +shouldn't train the teachers. + +I think this tells us you +train the teachers with + +information that is actually +useful, actionable, which + +might not be such revolutionary +thinking. + +But when you spend a lot of +time in education/health + +circle in Kenya, you realize +it's actually a pretty big, + +pretty controversial +statement. + +So Pascaline Dupas, when she was +still a Ph.D. student, she + +worked in this project, to do +something else, which we talk + +about also a little bit +in the book, which is + +the sugar daddy project. + +And what the sugar daddy project +is, is to tell the + +kids that it is not true that +sex with older people is safe. + +In fact, older people are much +more likely to infected with + +HIV than younger people. + +So that's the information that +was given, plus a nice video + +about a girl who managed to trap +someone who wants to be a + +sugar daddy and something like +that, a very short, very quick + +intervention. + +A little film produced by +UNICEF and then these + +statistics, which is your +chance to get an STD. + +The infection rate of older men +is much higher than the + +infection rate of younger men. + +And sadly, the infection rate +of girls is also higher than + +that of boys, for the reason +that girls are more likely to + +have sex with older men, who +are likely to be infected. + +So you are telling the girls, +you should really have sex + +with the boys, because they are +safer than the men, not + +quite in so many words, +but making + +the information available. + +And you're also telling the +boys that these innocent + +looking girls actually +are probably more + +risky than you think. + +And this intervention was +actually quite effective at + +reducing sex with older +partners, as indicated by the + +number of pregnancies +with older dads. + +It reduced the pregnancy with +older dads by 66%, 2/3. + +So this is also another sign of +the fact that, if you tell + +people the right thing, like +people will react to what it + +is you tell them. + +If you tell people the wrong +thing, they're also going to + +react to it. + +But they'll not react to it +in a way that is very. + +You don't get that many more +HSV2, and you get many more + +kids who are married with +older men and have + +children too early. + +So that's, maybe, the biggest +lesson from this finding is + +you should tell people the truth +and assume that they + +will be able to make the +right decisions. + +You don't have to scare them +away into doing things. + +So that's for that. + +So I guess the key lesson +is fertility + +decisions are like others. + +We need to try and +understand them. + +And this is one area where +policies have been based on + +the assumption that +people are idiots. + +And that's, I think, a very bad +assumption in general and + +particularly, perhaps, in this +area, because it's a very + +important decision that people +are much more likely to take, + +with a lot of thinking and +with a lot of you. + +So that brings us, pretty +naturally, into the next + +topic, which is, if it's +a decision, inherently, + +fertility decisions are +decisions that are made by a + +man and a woman. + +But if we think about it, a lot +of the other decisions we + +talked about in this class are +also decisions that are being + +made by a man and a woman. + +And we completely ignored that +our discussions so far. + +I've always talked about parents +decide how many, + +whether to immunize their kids, +how much to feed them, + +how many years of education they +should get, et cetera. + +And in this, I've ignored the +dynamic of the family. + +So now I want to spend +a bit of time-- + +not much, but the rest +of this lecture-- + +to talk about family +decisions. + +So the question, here, we're +going to ask is, how do + +families decide? + +So when we mean family, +we mean who? + +Like who decides? + +The dad decides. + +The mom decides. + +The mother-in-law decides. + +The kids, what do kids +have to play? + +They are relevant to all sorts +of decisions that are taken + +jointly by parents. + +Until now, we've ignored it. + +We've assumed that there was +something called, a family. + +And yet the family, we +know, is a group. + +So in what case would it be +legitimate to ignore the fact + +that the family is a +group of people? + +There are two cases where we +could say, well, we know it's + +a group, but we can ignore it. + +AUDIENCE: I would think all +families are the same? + +PROFESSOR: All family members. + +Like if we think that all family +members are the same, + +they all have the same +preferences, so they all want + +the same thing. + +So anybody who has been part of +a family, does this sound + +like a good approximation +to a family, the + +way a family functions? + +AUDIENCE: No. + +PROFESSOR: Not really. + +I think it's not the case +that there are no + +conflicts within families. + +People have different +views about how + +everything should be done. + +And the second way in which we +could ignore the fact that + +it's a collection of +individuals is? + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: If one person +made all the decisions. + +So we had the mother or the +father is like the person who + +makes all the decisions for +everyone, possibly taking into + +account people's preferences, +but not giving them a voice in + +how the decision +is being made. + +Does that sound a plausible +model of the family? + +AUDIENCE: At certain ages. + +PROFESSOR: Sorry? + +AUDIENCE: At certain ages. + +PROFESSOR: At certain ages, of +course, like the infant is not + +really in control, so someone +decides for them. + +Norm? + +AUDIENCE: Probably on the gender +breakdown, so the guys + +will decide, or the male +in the family will + +decide for the females. + +PROFESSOR: Right. + +So it might be that in some +societies, there is really a + +lot of control by the guys in +the family, as you say. + +But that will depend. + +Their society's say, you take +Pakistan or part of India, + +which will be more patriarchal +than Africa, where the African + +family is like-- + +it depends where, of course-- + +where there is more equality +between genders. + +So no one, maybe, is like +in a position to + +really, fully decide. + +So maybe the assumption that +one person decides for + +everyone is more plausible in +some cases, but we feel that + +it's not going to +be always true. + +And in a lot of cases, the +family is not one person. + +The family is a collection +of people. + +And they are trying +to fight it out. + +So women and men have different +preferences. + +For example, one area where +they have very different + +preferences is how many children +they want to have. + +So, for example, there was a +study in Zambia-- that I'm + +going to show you in a moment-- +showing that women + +want to have much fewer +children than men. + +So one reason, of course, would +be that it's Zambia and + +the probability of dying in +childbirth is not 0, while if + +you're the woman, you're more +likely to be the one who is + +paying the cost of that. + +So as Norm mentioned, the family +is patriarchal in many + +developing countries, so maybe +men take lot of decisions. + +But even there, you have, +usually, a little sphere, like + +how to buy the food, et cetera, +where it's really the + +woman who decides and +where bargaining + +could be taking place. + +So how do we test this? + +How do we know? + +How we can we try and see +whether the family is + +patriarchal, is unitary, either +everybody agrees or + +someone decides for everyone? + +So if the family behaves like +one individual, we could + +analyze the decision problem +of a family-- + +for example, how much food to +buy, whether to send the kids + +to school, how many children +to how, et cetera-- + +like the problem of +one single person. + +So the only thing that should +matter to a single person, + +and, therefore, to the family +in this context, is the + +family's overall income, +the prices of things-- + +how expensive it is to buy +whichever types of thing, + +school fees, et cetera-- + +and information that you have, +to everyone in the family. + +But if the family +is not unitary. + +It's what we call this model, +where one person decides for + +everyone or everybody agrees. + +We call this the unitary model, +like there is unity in + +the family. + +So if the family is not unitary, +than other things are + +going to start to matter. + +So, for example, it's not only +the overall income that is + +going to matter, but who +brings what share. + +Because they can now, say, well, +if you don't do what I + +want to do, then I'm just +going to take my + +income and go away. + +So now it's not the overall +income that's going to matter, + +it's the share of the income. + +So again, we could see men +taking much more decisions, + +that's because they are bring +more of the income. + +And we could see, maybe, that +when woman bring more income, + +they would be able to +take more decisions. + +The second thing that might +matter is private information. + +So if you know that the family +is not unitary, and you find + +something out, you might +keep it for you. + +Because that gives you some +power to make some decisions. + +So let's look at whether we +find evidence that private + +information, that is information +that one member + +has and not the other, makes a +difference in decisions and + +whether it's who brings +the income to + +family matters as well. + +Let's look at these +two things. + +So private information, let's +look at fertility. + +So I was telling this data from +Zambia showing that women + +want to have fewer +kids than men. + +And in fact, they report hiding +contraceptives from + +their husbands. + +So in that case, you could +ask a question. + +If I provide information to +women about contraceptives, + +would it make a difference if +I provide it to the woman + +alone or if I provide it +together to women and men? + +So under the unitary model, +what would we expect? + +AUDIENCE: Whoever the head of +the household is, [INAUDIBLE]. + +PROFESSOR: Yeah, whoever we give +it to, even if it's not + +the head, we give it +to the woman, she's + +going to tell the husband. + +So it should make +no difference. + +Or maybe it would even have a +bigger effect to give it to + +the men, because they are more +likely to understand, they're + +more likely to be involved, +et cetera. + +So a lot of family planning +policies are now saying, we + +have to involve the men. + +Because after all, the men +have something to do with + +contraception. + +That's the idea. + +Let's involve the men, and they +would be more likely to + +be informed. + +On the other hand, if it is the +case that women are more + +likely to want fewer children, +then involving only the woman, + +it gives her an option to hide +the contraception from her + +husband and, therefore, +potentially, + +to have fewer kids. + +So it could really +cut both ways. + +In the unitary model, you would +expect no difference or + +maybe doing it to both together +would be better. + +Or it would have a larger +effect, because the + +information would be +more likely to be + +diffused in the family. + +Under the non-unitary model, +maybe the woman + +would matter more. + +So what do you think +is happening? + +What's your bet? + +AUDIENCE: The women use +it more when their + +husbands don't know. + +PROFESSOR: Right. + +What they find is that women +use it much more when their + +husband doesn't how. + +So they did that? + +Well, they ran an experiment +where they provided people a + +voucher to skip the queue. + +Because in Zambia, in principle, +you are allowed to + +have contraception, et cetera. + +But in practice, it +takes a long time. + +The nurse calls you. + +Once you've come, if you don't +have your clothes for an + +examination. + +So people don't really go +to the family planning. + +So here, it's a voucher for +first class treatment, no need + +to bring your clothes and +a good, nice setting. + +So they did that. + +I don't know if it was half. + +But the separated the group in +two, one where they gave the + +voucher to the wife, alone, and +one where they gave it to + +wife and husband together. + +And so the question is whether +women are more likely to take + +care of their contraception, +whether they're more likely to + +be able to control their +fertility in one + +case than in the other. + +So that's what the find for the +take-up of the voucher. + +So the first two columns +are whether or not + +you redeemed a voucher. + +And the second two are whether +or not you get an injection of + +contraception, which is a method +of contraception that + +you can hide easily. + +Because you got the injection. + +No one knows that you +are not fertile for + +the next three months. + +And what you find is that people +are more likely to + +redeem the voucher in the +individual treatment than in + +the couple treatment . + +And they are more likely to +receive the concealable method + +in the individual treatment than +in a couple treatment. + +So the effects are of the +order of, let's say, 55% + +received a voucher in individual +versus 42%. + +So these are not negligible +effects. + +So it seems that it matters how +you provide information. + +It matters also for the number +of kids that people have. + +So this is the fraction of +births, in the months + +following the treatment, among +women, who said, at baseline, + +that they did not want +any more births. + +So you can think of them as +unwanted pregnancies. + +So six months later, +of course, you + +should see no effect. + +The couple treatment, which is +the red line, is a little + +below, but that's not due to +the treatment, because it's + +six months later. + +And then at nine months, +the couple cross. + +And the red line is above the +blue line for a few months, + +which reflects about three +months of Depo-Provera use. + +And then what happened is that +the effect on that, it + +disappears subsequently. + +And it goes up a lot for both. + +And the reason is that there was +a policy change in Zambia. + +All of the injectable were taken +away from the market. + +So any effect of the treatment +goes away, because after your + +first injection, you could +not get the second one. + +So we should expect an effect +in the 9 to 14 month, after + +the treatment, which is +exactly what we find. + +So if we look at the number of +unwanted births that were + +prevented-- + +I actually don't remember +exactly the number. + +But it's a fair number of +unwanted births that were + +prevented by going from +couple treatment to + +the woman only treatment. + +So that's the first indication +that the family is not + +unitary, because who you are +giving information to changes + +the outcome. + +So people hide information. + +The second information +is what economists + +call bargaining power. + +So even when the information +set is the same for both + +partners, they might start +to bargain over a family + +decision, who works, how hard, +how many children to have, how + +much to feed the children, +how much to educate the + +children, et cetera. + +So the bargaining power is your +ability to weigh-in on + +the family decision, if the +family decision are the + +process of these discussions. + +So what would affect a woman's +bargaining power, other than + +the information she has? + +So we already mentioned +an income. + +What else could be there? + +If you have good eyesight, you +can read it on the slide, but + +you can also think +about it instead. + +AUDIENCE: Maybe divorce +policy? + +PROFESSOR: Absolutely right. + +Divorce policy will affect +bargaining power. + +And how does it work? + +AUDIENCE: Depending on how +they allocate the family + +resources after divorce, +I don't know there. + +But I know in the past, in the +US, they would allocate it + +mostly to the man. + +And now, in a lot of +states, it's 50-50. + +PROFESSOR: Exactly. + +If you live in a divorce regime, +where all of the + +assets, and maybe the control +over the children, goes to the + +man, then for a woman to +divorce is a disaster. + +So when the take decisions, when +they bargain, they are + +thinking, what is my +outside option? + +And if I'm thinking my outside +option is absolutely horrible, + +then I have to agree +to whatever + +the husband is proposing. + +So the divorce laws are going +to make a difference. + +How much of the commons assets +can the woman get back, and + +how much control of kids +could she have? + +And in fact, it's been shown, +in the US, that when the + +change that you talked about +was implemented, it was + +implemented in different states +at different times. + +So you can trace what happened +to women, in particular, to + +decisions that are more in the +interest of the woman. + +You can see that the decisions, +within the + +household, improved in favor of +the woman when the divorce + +law improved to give +women more rights. + +So divorce law is one. + +AUDIENCE: Actually, +like health? + +So if the husband is in really +bad health, the woman probably + +has a lot of power +in the family. + +PROFESSOR: If the husband +has bad health, the + +woman has more power. + +Yes, that could be one. + +Maybe because his outside +option is now very bad, + +because A, he couldn't get +married to someone else, + +because he is so sick. + +B, he couldn't get by himself, +so he has to kind of be nice + +so that she will continue +to take care of him. + +AUDIENCE: So this slightly +related to a lot of them. + +If you came from a wealthy +family or came from a family + +with a status, the husband +couldn't get anything from the + +family, but just so as +not to embarrass + +himself in the society? + +PROFESSOR: Yes, exactly. + +So the family you're coming from +will influence bargaining + +power, because, maybe, not +wanting to embarrass himself. + +Also, because it could be a +threat that my very strong + +brothers are going to break +your kneecaps if you don't + +behave with me. + +So that creates like +an outside option. + +Also, in case of divorce, again, +it gives you a chance + +to come back to something, +whereas if you have no family, + +then you have no options. + +So that's very good, +your family, + +where people came from. + +What else could we have? + +AUDIENCE: The relative level +of education [INAUDIBLE]. + +If she's just been to high +school, [INAUDIBLE] + +make that economic decision. + +She may not have the mental +leverage to say, what I'm + +saying makes more sense. + +PROFESSOR: Yes. + +So that's very good. + +So the relative level of +education will matter, both + +because, again, it creates +some different outside + +options, because with a +high school dropout, + +what would you do? + +You're kind of dependent. + +And the other point you're +making, which is not about + +outside options, but even +your ability to bargain. + +You might not feel confident. + +When someone tells you that I +know better, you might feel + +like, yeah, maybe +you know better. + +Good. + +AUDIENCE: Is it possible to +consider that a woman could + +tell her husband, we won't have +intercourse if you don't + +do this and that. + +PROFESSOR: Yeah. + +Not only is it possible, but I +think that's a pretty frequent + +bargaining technique. + +So, in that case, if that's the +bargaining technique, then + +you would think how attractive +each partner is and how long + +they've been in a relationship +and things like that + +are going to matter. + +Because the level of the threat +is also whether or not + +you think it's a problem or +you could figure something + +else out if necessary. + +What else would we have? + +Well, one more is your ability +to earn an independent income. + +So that's related to the point +you're making about education. + +But it could also be just labor +market opportunities for + +men and women. + +So for example, if you live in +a society where women cannot + +get jobs, because say there is +[INAUDIBLE], then what will + +the woman do without husbands? + +There would be a big problem. + +Whereas if you live in a society +like here, where you + +could get a job, if you needed +to, then that changes your + +level of outside options, and, +therefore, changes the way the + +negotiations would be made. + +Another one is the +marriage market. + +Is it possible for a woman to +get married or for a man to + +get married after a divorce? + +There are some places +where it's harder. + +What is the gender ratio, how +many women there are for men? + +If you are in, for example, an +immigrant community, where the + +ratio of men to woman is very +skewed, because a lot of men + +have come, new men have come, +then the woman can threaten to + +get married to any of +those available + +boys within the community. + +That would increase their +bargaining power within the + +family compared to a situation +which is more even. + +People said that about China, +today, that one kind of + +strange consequences of the fact +that the gender ratio are + +completely skewed, due to +selective abortion and things + +like, it means that women, +actually, are in short supply. + +And therefore, it's getting +easier to marry them. + +And they have a lot of +bargaining power within the + +family, because there's no +substitute for them. + +So all of these things +would matter. + +So let's focus on one, for the +purpose of this, which is how + +much money women and men bring +to the family, and, in + +particular, how much money +they would have access to + +should they leave +the marriage. + +That's going to matter +for family decisions. + +So policy makers are very +convinced it's the case. + +So for example, all the cash +transfer programs that exist + +in Latin America, to encourage +schooling and health-- + +like the PROGRESA program in +Mexico, that we discussed in + +the case of education-- + +they tend to always give +the money to women. + +On the ground that A, women will +make a bigger use of the + +money, and B, that's going to +increase their bargaining + +power and, therefore, increase +all decisions. + +So there is very benign sexism +going on around in the policy + +world that women are generally +better people, which I don't + +necessarily disagree with. + +But it should be looked +into a little bit. + +So another one that is very +much inspired by this is + +microcredit. + +Microcredit claims, +the world-wide, + +are almost all women. + +Part of the reason is that +women are believed to be + +better at repaying. + +But part of the reason is also +that it was believed that it + +was a way to introduce some +changes, within their + +families, by giving power +to the family. + +So does it matter who gets money +or doesn't get money? + +I want to give one example to +prove my point that women are + +better people than men. + +Looking at one example where +money went into the household, + +either with the men or with +women, which is the end of + +Apartheid in South Africa. + +They took a pension program, +which existed for white + +people, which was, for white +people, a very small pension + +program, in that it was not +a lot of money for them. + +And also, almost no one was +eligible, because you couldn't + +be eligible if you had +a private pension. + +And most people have +private pensions. + +So it was smallish program on +the side, a little bit like we + +have here with minimum, +old-age security. + +But at the end of Apartheid, the +new government had to make + +a decision about, should we can +the program or should we + +expand it to the black +South Africans? + +Of course, they're not going to +keep two separate programs. + +And they decided to expand it, +because it was believed, + +rightly, that the older people, +who would be eligible + +for this program, are precisely +the people who + +suffered the most from +Apartheid, for + +their entire lifetime. + +So they expanded the program. + +And every man above 65 and +every woman about 60 is + +eligible for the program +unless they + +have a private pension. + +And very few of the black people +had a private pension. + +So about 85 to 90% percent of +people who are eligible + +actually get the program. + +So the old-age pension program, +which is still there + +today, it's a huge, huge deal. + +It's a lot of money. + +And it's very important +for the families. + +And, of course, a lot of the +older people don't live alone. + +They live with children or they +live with grandchildren. + +And in particular, in South +Africa, it is quite frequent + +that you have skip-generation +households, where you have a + +grandparent, no parent, +and the kids. + +This is for two reasons, one is +HIV/AIDS, which has killed + +a lot of the middle +generation. + +And the other is the way the +society was structured under + +Apartheid, people couldn't bring +their family when they + +went to work in the city. + +So they went alone, and they +left the kids behind with the + +grandparents. + +So for this reason, about a +quarter of kids, aged 0 to 5, + +live with a grandparent. + +And that grandparent +can either be a man + +or it can be a woman. + +And the question we can ask is, +does it make a difference, + +when this pension program comes +in, in 1993, if you + +happen to live with no one or +with a grandparent, who + +becomes eligible, or with a +grandfather or a grandmother? + +So of course, one problem is +that the families who have a + +grandfather are different from +the family who don't have a + +grandfather. + +So what we can look at is, let's +take a sample of kids + +who live with a grandfather, but +let's compare the one who + +lives with a grandfather who is, +let's say, 55, versus one + +who is 65 or a grandfather who +is 50 to 64 versus 66. + +So in both cases, there +is a grandfather. + +But one is just short +of being eligible. + +And one is just eligible. + +So other characteristics of the +family should be more or + +less constant. + +It just happened that your +age is a good thing. + +And of course, people couldn't +really predict that this + +pension was coming, so the kid +lives with a grandfather and, + +oh, he becomes just eligible +or is not yet eligible. + +The same thing with the +grandmother but around 60. + +So this is what this is doing. + +This is looking at weight +for height. + +So this is short trend +measure of nutrition. + +As soon as you start +eating better, you + +weight for height improves. + +And in orange, we have +the boys, and, in + +yellow, we have the girls. + +And you can see that. + +So what can you see? + +Can you interpret this? + +AUDIENCE: So this bar is +higher for eligible + +grandmothers that took all +their grandsons in. + +PROFESSOR: [INAUDIBLE] + +AUDIENCE: Heavier grandsons +and granddaughters. + +And my guess is that, because +they're eligible earlier, they + +have more to give earlier. + +PROFESSOR: So this +is right after + +eligibility in both cases. + +So we don't have a longer time. + +Yeah? + +AUDIENCE: Well, it's just to +show that grandmothers seem to + +care more about their +grandchildren than + +grandfathers do when they +become eligible. + +And then you can also +see the bias. + +So for grandmothers, it seems +like they treat girls better. + +And grandfathers also +treat girls better. + +PROFESSOR: So, basically, we +don't have much for the + +grandfathers. + +So the grandfather doesn't seem +to be using the money to + +be feeding the kids. + +And we have up a much larger +effect for the grandmothers, + +particularly for the girls. + +And some effects for the boys, +but only half the size. + +AUDIENCE: Now why is it the case +that the grandsons are + +worse off when their eligible +grandfathers [INAUDIBLE]? + +PROFESSOR: So if we had the +confidence interval bar on + +this graph, you would see that +this is not significant. + +So this is kind of same-ish. + +No eligible grandparents and +the bars for eligible + +grandfather are around +the same magnitude. + +What is really different +is the girls with the + +grandmother. + +And the boys to some extent, but +it's about half the size. + +AUDIENCE: So could there be an +effect in that, when you have + +an eligible grandfather, they're +older, so that they'll + +have to spend more of +their pension on + +like their own stuff? + +PROFESSOR: Yes. + +So that could be that. + +The grandfather is older. + +And also, men live less +longer than women. + +So actually, a 65-year-old man +is quite a bit older than a + +60-year-old woman. + +So that could be a reason. + +So we can start looking +at this kind + +of stuff, for example. + +Also, they might want to save +more of their pension if it's + +a grandfather, because he's +going to die very soon. + +So it's more like a transitory +income shock than a permanent + +income shock. + +So you might want to +say, let's save it. + +So we looked at saving, +too, to control. + +And we couldn't find a +difference in savings. + +The savings seem +to be the same. + +But you're right, it could be +explained by that, that the + +grandfathers need to be +spending the money on + +themselves, where the +grandmother doesn't need to. + +AUDIENCE: Also, could it +potentially be the case that + +the grandmothers may be alone +in the household, with their + +grandchildren, therefore they +would not have to spend + +anything on other people. + +Whereas, maybe in the culture, +it's more likely that a + +grandfather has to take care, +also, of his wife, therefore + +when he becomes eligible, there +is a greater fraction of + +his income that also +goes to a wife. + +PROFESSOR: That's +a good question. + +That can be tested. + +Because you can look at +all of the family size + +configurations. + +And you seem to find these +difference regardless of who + +is who is who. + +What is interesting, which helps +answering your question, + +is the grandmother could be the +mother's mother or could + +be the father's mother. + +So you can look at, the pension +goes to the mother's + +mother or to mother's father +or to father's mother or to + +the father's father. + +Which one do you +think matters? + +Under your hypothesis, if it's +only due to the health issue, + +what should we see? + +That mother's mothers and +mother's fathers should be the + +same and then the father would +be lower, because they need + +more money. + +And then, in practice, +what do we see? + +These high bar is only their +mother's mother. + +So it's only the pension +translating to higher health + +of the kids if it's a maternal +grandmother of a girl. + +So that seemed to have something +to do with these + +gender lines. + +And that doesn't mean that the +grandmother doesn't do other + +things for the kids. + +But in terms of how they decide +to feed the kids, it's + +really the identity of the +kid that matters a lot. + +So let me show you one last +thing, which is these results + +seem to show, relatively +clearly, that the family is + +not unitary. + +So who brings in the +resources matters. + +They actually do not show that +women are better people than + +men, because we don't +know what men do. + +Maybe they spend more on the +education of the children. + +I only showed you +a very partial + +window into the family. + +So the only conclusion we can +take from this is that + +families are not unitary. + +So the next question we +might want to ask + +is, are they efficient? + +In that, they are bargaining +with each other, but are they + +bargaining in a way that they +are first maximizing the size + +of the pie and then deciding +to split the pie? + +Or are they bargaining in a way +that the women would be + +willing to reduce the pie as +long as she could get a higher + +share of it? + +You understand the difference? + +So two people who would just +meet and who don't know each + +other, will tend to interact +with each other like in the + +prisoner's dilemma, that you +might have seen in game + +theory, which is they will try +to grab as much of the pie as + +they can, even if it makes +the pie lower. + +But two people who know each +other very well, who are in it + +for the longer run, might decide +that cooperating to + +make the size of the pie the +biggest possible is the first + +thing they should do and then +think about how to share it. + +And this is actually an idea +we can test, because + +households are engaged not only +in consumption but also + +in production. + +So if the direct analogy is to +first maximize the size of the + +pie and then decide how you're +going divide it, are they + +maximizing the production +that they can have. + +And one way to look at that is +farming, because in a lot of + +countries women and men grow +different plots of land. + +So in Burkina Faso, the study, +by Chris Udry, looking at + +households in which each member +is farming their own + +little plot. + +And an efficient household +should first use the inputs + +the most efficiently possible +and then decide on the basis + +of people's bargaining power +how to share the product. + +Once we condition for the +quality of the plot and the + +crop planted, we shouldn't see +that the women get fewer + +fertilizer or less labor or +less input or less seeds. + +And in fact, instead this paper +tested it and found that + +women get significantly less +of every input, including + +fertilizer. + +And fertilizer has very +concave returns. + +So there is really no point of +putting more fertilizer on a + +field of the men, when you could +put a little bit on the + +field of a woman, from the +point of view of family + +production. + +And that's not what you see. + +You see all of the fertilizer +being spent on the men's field + +and very little on the +women's fields. + +Which suggests that the family +is not efficient, because they + +could become richer by just +reallocating resources among + +themselves. + +So this suggests that the +family is not only not + +unitary, but it is also +not fully efficient. + +Which leads us to this question, +what role does the + +family play? + +What is the family +inefficient? + +And what implications does have +to policy, which we'll + +take up after you become all +refreshed from the vacation. \ No newline at end of file diff --git a/HKkSPqCOmD0.txt b/HKkSPqCOmD0.txt new file mode 100644 index 0000000000000000000000000000000000000000..f7cccd80fc45a9266e3a5d237254cbb660775409 --- /dev/null +++ b/HKkSPqCOmD0.txt @@ -0,0 +1,13979 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so last time we were talking + + align:start position:0% +ocw.mit.edu so last time we were talking + + + align:start position:0% +ocw.mit.edu so last time we were talking +about the KY lanin as another example of + + align:start position:0% +about the KY lanin as another example of + + + align:start position:0% +about the KY lanin as another example of +an effective field Theory to Ill + + align:start position:0% +an effective field Theory to Ill + + + align:start position:0% +an effective field Theory to Ill +illustrate some of the tools of + + align:start position:0% +illustrate some of the tools of + + + align:start position:0% +illustrate some of the tools of +effective field theory that we didn't + + align:start position:0% +effective field theory that we didn't + + + align:start position:0% +effective field theory that we didn't +meet when integrating out heavy + + align:start position:0% +meet when integrating out heavy + + + align:start position:0% +meet when integrating out heavy +particles was an example of a bottomup + + align:start position:0% +particles was an example of a bottomup + + + align:start position:0% +particles was an example of a bottomup +effective field Theory so we were + + align:start position:0% +effective field Theory so we were + + + align:start position:0% +effective field Theory so we were +constructing it from the bottom + + align:start position:0% +constructing it from the bottom + + + align:start position:0% +constructing it from the bottom +up um for the most part that's how one + + align:start position:0% +up um for the most part that's how one + + + align:start position:0% +up um for the most part that's how one +should think about it there is several + + align:start position:0% +should think about it there is several + + + align:start position:0% +should think about it there is several +things in our program to understand from + + align:start position:0% +things in our program to understand from + + + align:start position:0% +things in our program to understand from +car pration Theory we kind of got + + align:start position:0% +car pration Theory we kind of got + + + align:start position:0% +car pration Theory we kind of got +halfway through so we wanted to + + align:start position:0% +halfway through so we wanted to + + + align:start position:0% +halfway through so we wanted to +understand nonlinear symmetry + + align:start position:0% +understand nonlinear symmetry + + + align:start position:0% +understand nonlinear symmetry +representations and we went through how + + align:start position:0% +representations and we went through how + + + align:start position:0% +representations and we went through how +you could think about linear + + align:start position:0% +you could think about linear + + + align:start position:0% +you could think about linear +representations and making changes of + + align:start position:0% +representations and making changes of + + + align:start position:0% +representations and making changes of +variable and putting the in form where + + align:start position:0% +variable and putting the in form where + + + align:start position:0% +variable and putting the in form where +you could see where the nonlinear + + align:start position:0% +you could see where the nonlinear + + + align:start position:0% +you could see where the nonlinear +realization was coming from very + + align:start position:0% +realization was coming from very + + + align:start position:0% +realization was coming from very +explicitly as well as another way where + + align:start position:0% +explicitly as well as another way where + + + align:start position:0% +explicitly as well as another way where +we constructed it from the bottom + + align:start position:0% +we constructed it from the bottom + + + align:start position:0% +we constructed it from the bottom +up thinking about parameterizing the + + align:start position:0% +up thinking about parameterizing the + + + align:start position:0% +up thinking about parameterizing the +coet and then we started talking about + + align:start position:0% +coet and then we started talking about + + + align:start position:0% +coet and then we started talking about +loops in ch peration Theory and I gave + + align:start position:0% +loops in ch peration Theory and I gave + + + align:start position:0% +loops in ch peration Theory and I gave +you this example of this Loop here so we + + align:start position:0% +you this example of this Loop here so we + + + align:start position:0% +you this example of this Loop here so we +constructed the kyran that's what I've + + align:start position:0% +constructed the kyran that's what I've + + + align:start position:0% +constructed the kyran that's what I've +written here terms of this Sigma field + + align:start position:0% +written here terms of this Sigma field + + + align:start position:0% +written here terms of this Sigma field +this is the nonlinear version Sigma + + align:start position:0% +this is the nonlinear version Sigma + + + align:start position:0% +this is the nonlinear version Sigma +field exponential of M field M field has + + align:start position:0% +field exponential of M field M field has + + + align:start position:0% +field exponential of M field M field has +the pine fields in it I rewrote it in a + + align:start position:0% +the pine fields in it I rewrote it in a + + + align:start position:0% +the pine fields in it I rewrote it in a +little bit of a different notation which + + align:start position:0% +little bit of a different notation which + + + align:start position:0% +little bit of a different notation which +will be useful today where I introduced + + align:start position:0% +will be useful today where I introduced + + + align:start position:0% +will be useful today where I introduced +this thing called Kai but f^2 over 8 Kai + + align:start position:0% +this thing called Kai but f^2 over 8 Kai + + + align:start position:0% +this thing called Kai but f^2 over 8 Kai +is just mq so it's just a + + align:start position:0% +is just mq so it's just a + + + align:start position:0% +is just mq so it's just a +rescaling and I just want it to have the + + align:start position:0% +rescaling and I just want it to have the + + + align:start position:0% +rescaling and I just want it to have the +same kind of prefactor here and here + + align:start position:0% +same kind of prefactor here and here + + + align:start position:0% +same kind of prefactor here and here +that's why I did that the power counting + + align:start position:0% +that's why I did that the power counting + + + align:start position:0% +that's why I did that the power counting +is in p^2 derivatives or M pi^ squ which + + align:start position:0% +is in p^2 derivatives or M pi^ squ which + + + align:start position:0% +is in p^2 derivatives or M pi^ squ which +is the same as mq and the reason that + + align:start position:0% +is the same as mq and the reason that + + + align:start position:0% +is the same as mq and the reason that +that M pi^ squ and mq count the same is + + align:start position:0% +that M pi^ squ and mq count the same is + + + align:start position:0% +that M pi^ squ and mq count the same is +that is this relation between M pi^ squ + + align:start position:0% +that is this relation between M pi^ squ + + + align:start position:0% +that is this relation between M pi^ squ +and the Quark + + align:start position:0% +and the Quark + + + align:start position:0% +and the Quark +masses then we started talking about + + align:start position:0% +masses then we started talking about + + + align:start position:0% +masses then we started talking about +loops and we said that we if we looked + + align:start position:0% +loops and we said that we if we looked + + + align:start position:0% +loops and we said that we if we looked +at this Loop the result for this Loop + + align:start position:0% +at this Loop the result for this Loop + + + align:start position:0% +at this Loop the result for this Loop +diagram would be a factor of p^ s or M + + align:start position:0% +diagram would be a factor of p^ s or M + + + align:start position:0% +diagram would be a factor of p^ s or M +pi^ stimes a factor of P squ or M pi^ s + + align:start position:0% +pi^ stimes a factor of P squ or M pi^ s + + + align:start position:0% +pi^ stimes a factor of P squ or M pi^ s +divided by 4 Pi F so we Associated so + + align:start position:0% +divided by 4 Pi F so we Associated so + + + align:start position:0% +divided by 4 Pi F so we Associated so +this is what the lowest + + align:start position:0% + + + + align:start position:0% + +order this is this is the same size as + + align:start position:0% +order this is this is the same size as + + + align:start position:0% +order this is this is the same size as +the lowest order so the suppression + + align:start position:0% +the lowest order so the suppression + + + align:start position:0% +the lowest order so the suppression +factor is this + + align:start position:0% + + + + align:start position:0% + +so so we can say that Loops are + + align:start position:0% +so so we can say that Loops are + + + align:start position:0% +so so we can say that Loops are +suppressed by p^ S over some scale + + align:start position:0% +suppressed by p^ S over some scale + + + align:start position:0% +suppressed by p^ S over some scale +Lambda k^ squ is the scale of our + + align:start position:0% +Lambda k^ squ is the scale of our + + + align:start position:0% +Lambda k^ squ is the scale of our +expansion and we can associate that + + align:start position:0% +expansion and we can associate that + + + align:start position:0% +expansion and we can associate that +scale to 4 Pi time + + align:start position:0% +scale to 4 Pi time + + + align:start position:0% +scale to 4 Pi time +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +F okay so we're going to continue with + + align:start position:0% +F okay so we're going to continue with + + + align:start position:0% +F okay so we're going to continue with +that story unless there's any questions + + align:start position:0% +that story unless there's any questions + + + align:start position:0% +that story unless there's any questions +from last + + align:start position:0% +from last + + + align:start position:0% +from last +time okay so we want to uh use + + align:start position:0% +time okay so we want to uh use + + + align:start position:0% +time okay so we want to uh use +dimensional regularization and if we use + + align:start position:0% +dimensional regularization and if we use + + + align:start position:0% +dimensional regularization and if we use +dimensional + + align:start position:0% +dimensional + + + align:start position:0% +dimensional +regularization we can think about having + + align:start position:0% +regularization we can think about having + + + align:start position:0% +regularization we can think about having +an msar + + align:start position:0% + + + + align:start position:0% + +scheme so how do we do that it's a + + align:start position:0% +scheme so how do we do that it's a + + + align:start position:0% +scheme so how do we do that it's a +little different than gauge Theory but + + align:start position:0% +little different than gauge Theory but + + + align:start position:0% +little different than gauge Theory but +the idea is exactly the same so we look + + align:start position:0% +the idea is exactly the same so we look + + + align:start position:0% +the idea is exactly the same so we look +at the dimensions of objects this + + align:start position:0% +at the dimensions of objects this + + + align:start position:0% +at the dimensions of objects this +capital + + align:start position:0% +capital + + + align:start position:0% +capital +M to be a capital m + + align:start position:0% +M to be a capital m + + + align:start position:0% +M to be a capital m +is like a scalar field so it has + + align:start position:0% +is like a scalar field so it has + + + align:start position:0% +is like a scalar field so it has +Dimension 1 minus + + align:start position:0% +Dimension 1 minus + + + align:start position:0% +Dimension 1 minus +Epsilon the Decay + + align:start position:0% +Epsilon the Decay + + + align:start position:0% +Epsilon the Decay +constant then if you look at it which is + + align:start position:0% +constant then if you look at it which is + + + align:start position:0% +constant then if you look at it which is +the coupling has to have Dimension 1us + + align:start position:0% +the coupling has to have Dimension 1us + + + align:start position:0% +the coupling has to have Dimension 1us +Epsilon 2 and you can see that because + + align:start position:0% +Epsilon 2 and you can see that because + + + align:start position:0% +Epsilon 2 and you can see that because +this exponential better be the + + align:start position:0% +this exponential better be the + + + align:start position:0% +this exponential better be the +exponential of something dimensionless + + align:start position:0% +exponential of something dimensionless + + + align:start position:0% +exponential of something dimensionless +so that whatever the dimension of M + + align:start position:0% +so that whatever the dimension of M + + + align:start position:0% +so that whatever the dimension of M +should cancel the DI by the dimension of + + align:start position:0% +should cancel the DI by the dimension of + + + align:start position:0% +should cancel the DI by the dimension of +F and then that works out with the with + + align:start position:0% +F and then that works out with the with + + + align:start position:0% +F and then that works out with the with +the measure as well which has a d DDX + + align:start position:0% + + + + align:start position:0% + +so you can say therefore that F bear + + align:start position:0% +so you can say therefore that F bear + + + align:start position:0% +so you can say therefore that F bear +just like you did for a + + align:start position:0% +just like you did for a + + + align:start position:0% +just like you did for a +coupling a gauge coupling you can say F + + align:start position:0% +coupling a gauge coupling you can say F + + + align:start position:0% +coupling a gauge coupling you can say F +bear is some muus Epsilon * + + align:start position:0% + + + + align:start position:0% + +F and if you want to do the same thing + + align:start position:0% +F and if you want to do the same thing + + + align:start position:0% +F and if you want to do the same thing +for the second term although I've put + + align:start position:0% +for the second term although I've put + + + align:start position:0% +for the second term although I've put +the v0 inside the + + align:start position:0% +the v0 inside the + + + align:start position:0% +the v0 inside the +sorry there's something missing in my + + align:start position:0% +sorry there's something missing in my + + + align:start position:0% +sorry there's something missing in my +equation there was a v z + + align:start position:0% +equation there was a v z + + + align:start position:0% +equation there was a v z +here so before last time we written this + + align:start position:0% +here so before last time we written this + + + align:start position:0% +here so before last time we written this +equation as v0 out front and then mq + + align:start position:0% +equation as v0 out front and then mq + + + align:start position:0% +equation as v0 out front and then mq +inside and I just rescaled it to this + + align:start position:0% +inside and I just rescaled it to this + + + align:start position:0% +inside and I just rescaled it to this +Kai okay so you can think either in + + align:start position:0% +Kai okay so you can think either in + + + align:start position:0% +Kai okay so you can think either in +terms of Kai Kai is kind of absorbing + + align:start position:0% +terms of Kai Kai is kind of absorbing + + + align:start position:0% +terms of Kai Kai is kind of absorbing +the parameter into + + align:start position:0% +the parameter into + + + align:start position:0% +the parameter into +the into along with the + + align:start position:0% +the into along with the + + + align:start position:0% +the into along with the +mq but they're equivalent things so you + + align:start position:0% +mq but they're equivalent things so you + + + align:start position:0% +mq but they're equivalent things so you +can think of also doing a rescaling that + + align:start position:0% +can think of also doing a rescaling that + + + align:start position:0% +can think of also doing a rescaling that +gets the dimension of this term right + + align:start position:0% +gets the dimension of this term right + + + align:start position:0% +gets the dimension of this term right +and the thing that you want is + + align:start position:0% +and the thing that you want is + + + align:start position:0% +and the thing that you want is +this that b0 would then be mu to Theus 2 + + align:start position:0% +this that b0 would then be mu to Theus 2 + + + align:start position:0% +this that b0 would then be mu to Theus 2 +Epsilon to compensate for the fact that + + align:start position:0% +Epsilon to compensate for the fact that + + + align:start position:0% +Epsilon to compensate for the fact that +the first term had an f squ and the + + align:start position:0% +the first term had an f squ and the + + + align:start position:0% +the first term had an f squ and the +second term just had a + + align:start position:0% + + + + align:start position:0% + +v0 so that's just Dimension Counting + + align:start position:0% + + + + align:start position:0% + +there's also no M's in physical + + align:start position:0% +there's also no M's in physical + + + align:start position:0% +there's also no M's in physical +quantities like the pon Mass which is an + + align:start position:0% +quantities like the pon Mass which is an + + + align:start position:0% +quantities like the pon Mass which is an +observable which has just a definite + + align:start position:0% +observable which has just a definite + + + align:start position:0% +observable which has just a definite +value and there's also in K pration + + align:start position:0% +value and there's also in K pration + + + align:start position:0% +value and there's also in K pration +Theory no nor no M's in the Quark Mass + + align:start position:0% +Theory no nor no M's in the Quark Mass + + + align:start position:0% +Theory no nor no M's in the Quark Mass +so when you look at V 0 over + + align:start position:0% +so when you look at V 0 over + + + align:start position:0% +so when you look at V 0 over +f^2 if you look at it + + align:start position:0% + + + + align:start position:0% + +be that's the same as we normalized + + align:start position:0% + + + + align:start position:0% + +the other thing that's different about + + align:start position:0% +the other thing that's different about + + + align:start position:0% +the other thing that's different about +this than in a gauge theory is in the + + align:start position:0% +this than in a gauge theory is in the + + + align:start position:0% +this than in a gauge theory is in the +gauge Theory you'd have a z you'd have G + + align:start position:0% +gauge Theory you'd have a z you'd have G + + + align:start position:0% +gauge Theory you'd have a z you'd have G +bear is equal to m to the Epsilon time G + + align:start position:0% +bear is equal to m to the Epsilon time G + + + align:start position:0% +bear is equal to m to the Epsilon time G +but then you'd have a + + align:start position:0% +but then you'd have a + + + align:start position:0% +but then you'd have a +zg but in caral pration theory the way + + align:start position:0% +zg but in caral pration theory the way + + + align:start position:0% +zg but in caral pration theory the way +that the loops work the loops aren't + + align:start position:0% +that the loops work the loops aren't + + + align:start position:0% +that the loops work the loops aren't +renormalizing the leading order + + align:start position:0% +renormalizing the leading order + + + align:start position:0% +renormalizing the leading order +lran the loops are renormalizing + + align:start position:0% +lran the loops are renormalizing + + + align:start position:0% +lran the loops are renormalizing +something else because they ended up + + align:start position:0% +something else because they ended up + + + align:start position:0% +something else because they ended up +being suppressed so you don't need + + align:start position:0% +being suppressed so you don't need + + + align:start position:0% +being suppressed so you don't need +counter terms here for the leading order + + align:start position:0% +counter terms here for the leading order + + + align:start position:0% +counter terms here for the leading order +lran + + align:start position:0% +lran + + + align:start position:0% +lran +that's why I didn't put a ZF or a zv0 + + align:start position:0% + + + + align:start position:0% + +here okay but when you do this Loop you + + align:start position:0% +here okay but when you do this Loop you + + + align:start position:0% +here okay but when you do this Loop you +do get ultraviolet + + align:start position:0% + + + + align:start position:0% + +divergences so you get a one over + + align:start position:0% +divergences so you get a one over + + + align:start position:0% +divergences so you get a one over +Epsilon Divergence if you're using + + align:start position:0% +Epsilon Divergence if you're using + + + align:start position:0% +Epsilon Divergence if you're using +dimensional regularization and it comes + + align:start position:0% +dimensional regularization and it comes + + + align:start position:0% +dimensional regularization and it comes +along with the log of mu^ + + align:start position:0% +along with the log of mu^ + + + align:start position:0% +along with the log of mu^ +2 and then it'll be divided by some + + align:start position:0% +2 and then it'll be divided by some + + + align:start position:0% +2 and then it'll be divided by some +scale that you have in your Loop like an + + align:start position:0% +scale that you have in your Loop like an + + + align:start position:0% +scale that you have in your Loop like an +external momentum p^ s or it could + + align:start position:0% + + + + align:start position:0% + +be the pon Mass both of those will show + + align:start position:0% +be the pon Mass both of those will show + + + align:start position:0% +be the pon Mass both of those will show +up + + align:start position:0% + + + + align:start position:0% + +generically and in the way we're doing + + align:start position:0% +generically and in the way we're doing + + + align:start position:0% +generically and in the way we're doing +counting + + align:start position:0% + + + + align:start position:0% + +the way the the loops are showing up if + + align:start position:0% +the way the the loops are showing up if + + + align:start position:0% +the way the the loops are showing up if +I combine together the factors that I + + align:start position:0% +I combine together the factors that I + + + align:start position:0% +I combine together the factors that I +told you about here it's either P to 4 + + align:start position:0% +told you about here it's either P to 4 + + + align:start position:0% +told you about here it's either P to 4 +four power of P or two of p and two of + + align:start position:0% +four power of P or two of p and two of + + + align:start position:0% +four power of P or two of p and two of +Mi Pi or four power of Mi + + align:start position:0% +Mi Pi or four power of Mi + + + align:start position:0% +Mi Pi or four power of Mi +Pi so to cancel that one over Epsilon we + + align:start position:0% +Pi so to cancel that one over Epsilon we + + + align:start position:0% +Pi so to cancel that one over Epsilon we +need a counter term but it's not a + + align:start position:0% +need a counter term but it's not a + + + align:start position:0% +need a counter term but it's not a +counter term in that lrange and it's a + + align:start position:0% +counter term in that lrange and it's a + + + align:start position:0% +counter term in that lrange and it's a +counter term in the higherorder LAN + + align:start position:0% + + + + align:start position:0% + +so we're not done by just calculating + + align:start position:0% +so we're not done by just calculating + + + align:start position:0% +so we're not done by just calculating +the loop we have to actually include + + align:start position:0% +the loop we have to actually include + + + align:start position:0% +the loop we have to actually include +some higher Dimension operators that are + + align:start position:0% +some higher Dimension operators that are + + + align:start position:0% +some higher Dimension operators that are +the same order in our power + + align:start position:0% + + + + align:start position:0% + +counting so we'll talk about su3 a + + align:start position:0% +counting so we'll talk about su3 a + + + align:start position:0% +counting so we'll talk about su3 a +little later I'll start out by talking + + align:start position:0% +little later I'll start out by talking + + + align:start position:0% +little later I'll start out by talking +about + + align:start position:0% +about + + + align:start position:0% +about +su2 in su2 the form of that lran with + + align:start position:0% +su2 in su2 the form of that lran with + + + align:start position:0% +su2 in su2 the form of that lran with +high order terms is just taking what we + + align:start position:0% +high order terms is just taking what we + + + align:start position:0% +high order terms is just taking what we +had before and just going to a higher + + align:start position:0% + + + + align:start position:0% + +Dimension so we could have two more + + align:start position:0% +Dimension so we could have two more + + + align:start position:0% +Dimension so we could have two more +derivatives one way of doing that is + + align:start position:0% +derivatives one way of doing that is + + + align:start position:0% +derivatives one way of doing that is +taking what we had at lowest order and + + align:start position:0% +taking what we had at lowest order and + + + align:start position:0% +taking what we had at lowest order and +squaring + + align:start position:0% + + + + align:start position:0% + +it another way of doing it would be to + + align:start position:0% +it another way of doing it would be to + + + align:start position:0% +it another way of doing it would be to +take and contract the indices a little + + align:start position:0% +take and contract the indices a little + + + align:start position:0% +take and contract the indices a little +bit differently + + align:start position:0% + + + + align:start position:0% + +so I could do it like + + align:start position:0% + + + + align:start position:0% + +this the trace is cyclic so I can move + + align:start position:0% +this the trace is cyclic so I can move + + + align:start position:0% +this the trace is cyclic so I can move +things around from back to front but I + + align:start position:0% +things around from back to front but I + + + align:start position:0% +things around from back to front but I +could have mu new in one trace and mu + + align:start position:0% +could have mu new in one trace and mu + + + align:start position:0% +could have mu new in one trace and mu +new in another Trace rather than just + + align:start position:0% +new in another Trace rather than just + + + align:start position:0% +new in another Trace rather than just +Contracting within the trace that's + + align:start position:0% +Contracting within the trace that's + + + align:start position:0% +Contracting within the trace that's +another possible + + align:start position:0% +another possible + + + align:start position:0% +another possible +term and there's a bunch more terms + + align:start position:0% +term and there's a bunch more terms + + + align:start position:0% +term and there's a bunch more terms +which I decided to wait in enumerate + + align:start position:0% +which I decided to wait in enumerate + + + align:start position:0% +which I decided to wait in enumerate +when we do su3 to give you a full + + align:start position:0% +when we do su3 to give you a full + + + align:start position:0% +when we do su3 to give you a full +enumeration these additional terms + + align:start position:0% + + + + align:start position:0% + +you can + + align:start position:0% +you can + + + align:start position:0% +you can +build from one mq which means one of + + align:start position:0% +build from one mq which means one of + + + align:start position:0% +build from one mq which means one of +these Kai Fields or Kai + + align:start position:0% + + + + align:start position:0% + +objects and two partials that's one + + align:start position:0% +objects and two partials that's one + + + align:start position:0% +objects and two partials that's one +possibility or two + + align:start position:0% + + + + align:start position:0% + +mqs because each kemq counts like two + + align:start position:0% +mqs because each kemq counts like two + + + align:start position:0% +mqs because each kemq counts like two +derivatives so there's some other terms + + align:start position:0% +derivatives so there's some other terms + + + align:start position:0% +derivatives so there's some other terms +that we could build that are analoges of + + align:start position:0% +that we could build that are analoges of + + + align:start position:0% +that we could build that are analoges of +this this term you could square that + + align:start position:0% +this this term you could square that + + + align:start position:0% +this this term you could square that +term for example that would be a + + align:start position:0% +term for example that would be a + + + align:start position:0% +term for example that would be a +possible higher order + + align:start position:0% +possible higher order + + + align:start position:0% +possible higher order +term and so these coefficients of this + + align:start position:0% +term and so these coefficients of this + + + align:start position:0% +term and so these coefficients of this +lran are what we need to cancel off the + + align:start position:0% +lran are what we need to cancel off the + + + align:start position:0% +lran are what we need to cancel off the +divergences so the the counter terms + + align:start position:0% +divergences so the the counter terms + + + align:start position:0% +divergences so the the counter terms +that we have that re normalize these + + align:start position:0% +that we have that re normalize these + + + align:start position:0% +that we have that re normalize these +Loop graphs come from this lru + + align:start position:0% + + + + align:start position:0% + +so the theory is we're normalizable in a + + align:start position:0% +so the theory is we're normalizable in a + + + align:start position:0% +so the theory is we're normalizable in a +EFT sense order by order in its power + + align:start position:0% +EFT sense order by order in its power + + + align:start position:0% +EFT sense order by order in its power +counting expansion when you go to order + + align:start position:0% +counting expansion when you go to order + + + align:start position:0% +counting expansion when you go to order +P to 4th you have to consistently put in + + align:start position:0% +P to 4th you have to consistently put in + + + align:start position:0% +P to 4th you have to consistently put in +everything that's order P to the 4th + + align:start position:0% +everything that's order P to the 4th + + + align:start position:0% +everything that's order P to the 4th +that's includes the loops which are P to + + align:start position:0% +that's includes the loops which are P to + + + align:start position:0% +that's includes the loops which are P to +the 4th as well as new local LR + + align:start position:0% +the 4th as well as new local LR + + + align:start position:0% +the 4th as well as new local LR +interactions + + align:start position:0% +interactions + + + align:start position:0% +interactions +is that a choice to not renormalize the + + align:start position:0% +is that a choice to not renormalize the + + + align:start position:0% +is that a choice to not renormalize the +F and they just don't get + + align:start position:0% +F and they just don't get + + + align:start position:0% +F and they just don't get +renormalized but why could I just m by + + align:start position:0% +renormalized but why could I just m by + + + align:start position:0% +renormalized but why could I just m by +one + + align:start position:0% +one + + + align:start position:0% +one +p + + align:start position:0% +p + + + align:start position:0% +p +yeah oh to make you want to try to make + + align:start position:0% +yeah oh to make you want to try to make + + + align:start position:0% +yeah oh to make you want to try to make +a a different scheme for them SC the + + align:start position:0% +a a different scheme for them SC the + + + align:start position:0% +a a different scheme for them SC the +power counting so + + align:start position:0% +power counting so + + + align:start position:0% +power counting so +um so + + align:start position:0% + + + + align:start position:0% + +effectively you could screw up the power + + align:start position:0% +effectively you could screw up the power + + + align:start position:0% +effectively you could screw up the power +counting by doing that so you could let + + align:start position:0% +counting by doing that so you could let + + + align:start position:0% +counting by doing that so you could let +me let me tell you what you can do you + + align:start position:0% +me let me tell you what you can do you + + + align:start position:0% +me let me tell you what you can do you +could put a two here + + align:start position:0% + + + + align:start position:0% + +right but you don't really have much + + align:start position:0% +right but you don't really have much + + + align:start position:0% +right but you don't really have much +more freedom than just multiplying by a + + align:start position:0% +more freedom than just multiplying by a + + + align:start position:0% +more freedom than just multiplying by a +number so I can't multiply by one plus p + + align:start position:0% +number so I can't multiply by one plus p + + + align:start position:0% +number so I can't multiply by one plus p +s um yeah that would be a screwing up + + align:start position:0% +s um yeah that would be a screwing up + + + align:start position:0% +s um yeah that would be a screwing up +the power counting and effectively + + align:start position:0% +the power counting and effectively + + + align:start position:0% +the power counting and effectively +that's you know what you wouldn't be + + align:start position:0% +that's you know what you wouldn't be + + + align:start position:0% +that's you know what you wouldn't be +multiplying by P squ you'd be putting + + align:start position:0% +multiplying by P squ you'd be putting + + + align:start position:0% +multiplying by P squ you'd be putting +derivatives in right because there's no + + align:start position:0% +derivatives in right because there's no + + + align:start position:0% +derivatives in right because there's no +p and yeah so you + + align:start position:0% +p and yeah so you + + + align:start position:0% +p and yeah so you +you p is not something allow that you're + + align:start position:0% +you p is not something allow that you're + + + align:start position:0% +you p is not something allow that you're +allowed to multiply by that's the only + + align:start position:0% +allowed to multiply by that's the only + + + align:start position:0% +allowed to multiply by that's the only +thing that's soling me though is derives + + align:start position:0% +thing that's soling me though is derives + + + align:start position:0% +thing that's soling me though is derives +you could put derivatives in but then + + align:start position:0% +you could put derivatives in but then + + + align:start position:0% +you could put derivatives in but then +that's equivalent to something here so + + align:start position:0% +that's equivalent to something here so + + + align:start position:0% +that's equivalent to something here so +you have to ask what you're doing + + align:start position:0% +you have to ask what you're doing + + + align:start position:0% +you have to ask what you're doing +because you're mixing up things yeah + + align:start position:0% +because you're mixing up things yeah + + + align:start position:0% +because you're mixing up things yeah +definely better way to do + + align:start position:0% +definely better way to do + + + align:start position:0% +definely better way to do +ited yeah there's no Freedom really good + + align:start position:0% +ited yeah there's no Freedom really good + + + align:start position:0% +ited yeah there's no Freedom really good +why you don't + + align:start position:0% +why you don't + + + align:start position:0% +why you don't +get + + align:start position:0% +get + + + align:start position:0% +get +di because all the loops end up being + + align:start position:0% +di because all the loops end up being + + + align:start position:0% +di because all the loops end up being +suppressed by + + align:start position:0% +suppressed by + + + align:start position:0% +suppressed by +p^2 or M pi^ squ so if you put any write + + align:start position:0% +p^2 or M pi^ squ so if you put any write + + + align:start position:0% +p^2 or M pi^ squ so if you put any write +down any diagram and you think you're it + + align:start position:0% +down any diagram and you think you're it + + + align:start position:0% +down any diagram and you think you're it +might you know give something here even + + align:start position:0% +might you know give something here even + + + align:start position:0% +might you know give something here even +if it's a two-point function it uh it + + align:start position:0% +if it's a two-point function it uh it + + + align:start position:0% +if it's a two-point function it uh it +just + + align:start position:0% +just + + + align:start position:0% +just +doesn't + + align:start position:0% + + + + align:start position:0% + +anding that's right so this these terms + + align:start position:0% +anding that's right so this these terms + + + align:start position:0% +anding that's right so this these terms +oh so if you want you could think you + + align:start position:0% +oh so if you want you could think you + + + align:start position:0% +oh so if you want you could think you +know that some terms here are kind of + + align:start position:0% +know that some terms here are kind of + + + align:start position:0% +know that some terms here are kind of +Corrections to the kinetic term if you + + align:start position:0% +Corrections to the kinetic term if you + + + align:start position:0% +Corrections to the kinetic term if you +you know if you would derive the + + align:start position:0% +you know if you would derive the + + + align:start position:0% +you know if you would derive the +equation of motion and you include L and + + align:start position:0% +equation of motion and you include L and + + + align:start position:0% +equation of motion and you include L and +that L and this L right + + align:start position:0% +that L and this L right + + + align:start position:0% +that L and this L right +but um but this lran here does not get + + align:start position:0% +but um but this lran here does not get + + + align:start position:0% +but um but this lran here does not get +corre there's no Loop corrections to + + align:start position:0% +corre there's no Loop corrections to + + + align:start position:0% +corre there's no Loop corrections to +this lran there's no corrections to + + align:start position:0% +this lran there's no corrections to + + + align:start position:0% +this lran there's no corrections to +this lowest order of lran and that's + + align:start position:0% +this lowest order of lran and that's + + + align:start position:0% +this lowest order of lran and that's +because the loops are all suppressed by + + align:start position:0% +because the loops are all suppressed by + + + align:start position:0% +because the loops are all suppressed by +totally different than gauge Theory + + align:start position:0% +totally different than gauge Theory + + + align:start position:0% +totally different than gauge Theory +Loops are suppressed by P squ or M Pi + + align:start position:0% +Loops are suppressed by P squ or M Pi + + + align:start position:0% +Loops are suppressed by P squ or M Pi +squ so they only re normalize some + + align:start position:0% +squ so they only re normalize some + + + align:start position:0% +squ so they only re normalize some +higher order things we don't have to + + align:start position:0% +higher order things we don't have to + + + align:start position:0% +higher order things we don't have to +worry about + + align:start position:0% +worry about + + + align:start position:0% +worry about +um really thinking about F I mean the + + align:start position:0% +um really thinking about F I mean the + + + align:start position:0% +um really thinking about F I mean the +way I've decided the way I've talked + + align:start position:0% +way I've decided the way I've talked + + + align:start position:0% +way I've decided the way I've talked +about F here and the factors of mu is + + align:start position:0% +about F here and the factors of mu is + + + align:start position:0% +about F here and the factors of mu is +just just in order to you know see where + + align:start position:0% +just just in order to you know see where + + + align:start position:0% +just just in order to you know see where +these factors of me come out here but + + align:start position:0% +these factors of me come out here but + + + align:start position:0% +these factors of me come out here but +what actually happens is that you you + + align:start position:0% +what actually happens is that you you + + + align:start position:0% +what actually happens is that you you +get uh one over epsilons that are + + align:start position:0% +get uh one over epsilons that are + + + align:start position:0% +get uh one over epsilons that are +cancelled by the counter terms here and + + align:start position:0% +cancelled by the counter terms here and + + + align:start position:0% +cancelled by the counter terms here and +there's no kind of change of no need + + align:start position:0% +there's no kind of change of no need + + + align:start position:0% +there's no kind of change of no need +from a renormalization perspective to + + align:start position:0% +from a renormalization perspective to + + + align:start position:0% +from a renormalization perspective to +sort of change your definitions here + + align:start position:0% +sort of change your definitions here + + + align:start position:0% +sort of change your definitions here +people play with different definitions + + align:start position:0% +people play with different definitions + + + align:start position:0% +people play with different definitions +but it's like they use f^2 over 4 + + align:start position:0% +but it's like they use f^2 over 4 + + + align:start position:0% +but it's like they use f^2 over 4 +instead of f s 8 that's the extent of + + align:start position:0% +instead of f s 8 that's the extent of + + + align:start position:0% +instead of f s 8 that's the extent of +what people do with the playing with the + + align:start position:0% +what people do with the playing with the + + + align:start position:0% +what people do with the playing with the +leading order liy so it's the same thing + + align:start position:0% +leading order liy so it's the same thing + + + align:start position:0% +leading order liy so it's the same thing +with the with the + + align:start position:0% + + + + align:start position:0% + +both of them are not yeah yeah so Loops + + align:start position:0% +both of them are not yeah yeah so Loops + + + align:start position:0% +both of them are not yeah yeah so Loops +that you build out of these interactions + + align:start position:0% +that you build out of these interactions + + + align:start position:0% +that you build out of these interactions +end up renormalizing these these + + align:start position:0% + + + + align:start position:0% + +terms which is kind of + + align:start position:0% + + + + align:start position:0% + +neat yeah I mean it well we so we'll + + align:start position:0% +neat yeah I mean it well we so we'll + + + align:start position:0% +neat yeah I mean it well we so we'll +prove in a minute like a general power + + align:start position:0% +prove in a minute like a general power + + + align:start position:0% +prove in a minute like a general power +Counting formula that tells us how to + + align:start position:0% +Counting formula that tells us how to + + + align:start position:0% +Counting formula that tells us how to +organize all + + align:start position:0% +organize all + + + align:start position:0% +organize all +this so for now you can think of it as + + align:start position:0% +this so for now you can think of it as + + + align:start position:0% +this so for now you can think of it as +an observation but we'll we'll build it + + align:start position:0% +an observation but we'll we'll build it + + + align:start position:0% +an observation but we'll we'll build it +into a general formula that tells you + + align:start position:0% +into a general formula that tells you + + + align:start position:0% +into a general formula that tells you +sort of how you would organize the the + + align:start position:0% +sort of how you would organize the the + + + align:start position:0% +sort of how you would organize the the +power counting and re normalization of + + align:start position:0% +power counting and re normalization of + + + align:start position:0% +power counting and re normalization of +this Theory to all orders in its + + align:start position:0% +this Theory to all orders in its + + + align:start position:0% +this Theory to all orders in its +expansion in a + + align:start position:0% +expansion in a + + + align:start position:0% +expansion in a +minute so when you write down all + + align:start position:0% +minute so when you write down all + + + align:start position:0% +minute so when you write down all +these does that all the you need yeah + + align:start position:0% +these does that all the you need yeah + + + align:start position:0% +these does that all the you need yeah +that's right so all the once I've + + align:start position:0% +that's right so all the once I've + + + align:start position:0% +that's right so all the once I've +enumerated all the terms which I will do + + align:start position:0% +enumerated all the terms which I will do + + + align:start position:0% +enumerated all the terms which I will do +for you with su3 so it includes things + + align:start position:0% +for you with su3 so it includes things + + + align:start position:0% +for you with su3 so it includes things +like this and things like this as well + + align:start position:0% +like this and things like this as well + + + align:start position:0% +like this and things like this as well +then those are all the possible counter + + align:start position:0% +then those are all the possible counter + + + align:start position:0% +then those are all the possible counter +terms that you could actually need to + + align:start position:0% +terms that you could actually need to + + + align:start position:0% +terms that you could actually need to +renormalize any of the one Loop diagrams + + align:start position:0% +renormalize any of the one Loop diagrams + + + align:start position:0% +renormalize any of the one Loop diagrams +that you could generate with the leading + + align:start position:0% +that you could generate with the leading + + + align:start position:0% +that you could generate with the leading +order of the GR in and you know that by + + align:start position:0% +order of the GR in and you know that by + + + align:start position:0% +order of the GR in and you know that by +power + + align:start position:0% +power + + + align:start position:0% +power +counting once you know the loops are + + align:start position:0% +counting once you know the loops are + + + align:start position:0% +counting once you know the loops are +that order and you've included all local + + align:start position:0% +that order and you've included all local + + + align:start position:0% +that order and you've included all local +interactions then then you're + + align:start position:0% + + + + align:start position:0% + +done so there's things I didn't write + + align:start position:0% +done so there's things I didn't write + + + align:start position:0% +done so there's things I didn't write +down there + + align:start position:0% +down there + + + align:start position:0% +down there +um so just comment about that so what is + + align:start position:0% +um so just comment about that so what is + + + align:start position:0% +um so just comment about that so what is +the equation of motion + + align:start position:0% +the equation of motion + + + align:start position:0% +the equation of motion +here it's a little more complicated + + align:start position:0% +here it's a little more complicated + + + align:start position:0% +here it's a little more complicated +because we have the sigma field but you + + align:start position:0% +because we have the sigma field but you + + + align:start position:0% +because we have the sigma field but you +can work out that the equation of motion + + align:start position:0% +can work out that the equation of motion + + + align:start position:0% +can work out that the equation of motion +is the + + align:start position:0% + + + + align:start position:0% + +following and I've given you some + + align:start position:0% +following and I've given you some + + + align:start position:0% +following and I've given you some +reading + + align:start position:0% +reading + + + align:start position:0% +reading +just show you so you can read about a + + align:start position:0% +just show you so you can read about a + + + align:start position:0% +just show you so you can read about a +derivation of this equation just takes a + + align:start position:0% +derivation of this equation just takes a + + + align:start position:0% +derivation of this equation just takes a +little effort so leading order equation + + align:start position:0% +little effort so leading order equation + + + align:start position:0% +little effort so leading order equation +of motion basically allows you to get + + align:start position:0% +of motion basically allows you to get + + + align:start position:0% +of motion basically allows you to get +rid of partial squares on the sigma and + + align:start position:0% +rid of partial squares on the sigma and + + + align:start position:0% +rid of partial squares on the sigma and +that's why I've always written the + + align:start position:0% +that's why I've always written the + + + align:start position:0% +that's why I've always written the +partial one partial on each Sigma so + + align:start position:0% +partial one partial on each Sigma so + + + align:start position:0% +partial one partial on each Sigma so +that's what you should think of this guy + + align:start position:0% +that's what you should think of this guy + + + align:start position:0% +that's what you should think of this guy +doing + + align:start position:0% + + + + align:start position:0% + +there's also some su2 identities that + + align:start position:0% +there's also some su2 identities that + + + align:start position:0% +there's also some su2 identities that +have been + + align:start position:0% + + + + align:start position:0% + +used even in what I've + + align:start position:0% +used even in what I've + + + align:start position:0% +used even in what I've +written because you could think of + + align:start position:0% +written because you could think of + + + align:start position:0% +written because you could think of +having other types of traces like this + + align:start position:0% +having other types of traces like this + + + align:start position:0% +having other types of traces like this +one for example like instead of having + + align:start position:0% +one for example like instead of having + + + align:start position:0% +one for example like instead of having +Trace squared I could have the + + align:start position:0% +Trace squared I could have the + + + align:start position:0% +Trace squared I could have the +following just put everything in one + + align:start position:0% + + + + align:start position:0% + +Trace I always have to alternate Sigma + + align:start position:0% +Trace I always have to alternate Sigma + + + align:start position:0% +Trace I always have to alternate Sigma +Sigma dagger Sigma Sigma dagger + + align:start position:0% +Sigma dagger Sigma Sigma dagger + + + align:start position:0% +Sigma dagger Sigma Sigma dagger +because Del mu Sigma Sigma dger is zero + + align:start position:0% +because Del mu Sigma Sigma dger is zero + + + align:start position:0% +because Del mu Sigma Sigma dger is zero +because Sigma Sigma dger is one and that + + align:start position:0% +because Sigma Sigma dger is one and that + + + align:start position:0% +because Sigma Sigma dger is one and that +provides an identity that I'm also able + + align:start position:0% +provides an identity that I'm also able + + + align:start position:0% +provides an identity that I'm also able +to + + align:start position:0% +to + + + align:start position:0% +to +use and so I want to have sigmas and + + align:start position:0% +use and so I want to have sigmas and + + + align:start position:0% +use and so I want to have sigmas and +sigma daggers next to each + + align:start position:0% +sigma daggers next to each + + + align:start position:0% +sigma daggers next to each +other to avoid having so that's one + + align:start position:0% +other to avoid having so that's one + + + align:start position:0% +other to avoid having so that's one +thing sorry chyal symmetry means that + + align:start position:0% +thing sorry chyal symmetry means that + + + align:start position:0% +thing sorry chyal symmetry means that +sigas and sigma diag should be next to + + align:start position:0% +sigas and sigma diag should be next to + + + align:start position:0% +sigas and sigma diag should be next to +each other uh this is an identity that I + + align:start position:0% +each other uh this is an identity that I + + + align:start position:0% +each other uh this is an identity that I +can also use to to simplify things so + + align:start position:0% +can also use to to simplify things so + + + align:start position:0% +can also use to to simplify things so +that allows me to move things around and + + align:start position:0% +that allows me to move things around and + + + align:start position:0% +that allows me to move things around and +this operator though in su2 is actually + + align:start position:0% +this operator though in su2 is actually + + + align:start position:0% +this operator though in su2 is actually +related to these two it's not unique + + align:start position:0% +related to these two it's not unique + + + align:start position:0% +related to these two it's not unique +because of the structure of poly + + align:start position:0% +because of the structure of poly + + + align:start position:0% +because of the structure of poly +matrices you have a formula which you + + align:start position:0% +matrices you have a formula which you + + + align:start position:0% +matrices you have a formula which you +can work out which says that this guy is + + align:start position:0% +can work out which says that this guy is + + + align:start position:0% +can work out which says that this guy is +actually a half of the trace + + align:start position:0% + + + + align:start position:0% + +squared and there's another + + align:start position:0% +squared and there's another + + + align:start position:0% +squared and there's another +one if you did + + align:start position:0% + + + + align:start position:0% + +this guy he + + align:start position:0% +this guy he + + + align:start position:0% +this guy he +also can be Rel related to those two + + align:start position:0% +also can be Rel related to those two + + + align:start position:0% +also can be Rel related to those two +guys over + + align:start position:0% +guys over + + + align:start position:0% +guys over +there okay so there's a bunch of things + + align:start position:0% +there okay so there's a bunch of things + + + align:start position:0% +there okay so there's a bunch of things +that went into even writing down the + + align:start position:0% +that went into even writing down the + + + align:start position:0% +that went into even writing down the +level of information that I told you you + + align:start position:0% +level of information that I told you you + + + align:start position:0% +level of information that I told you you +could think there's more things but then + + align:start position:0% +could think there's more things but then + + + align:start position:0% +could think there's more things but then +you when you enumerate all the possible + + align:start position:0% +you when you enumerate all the possible + + + align:start position:0% +you when you enumerate all the possible +things that you can do you find that + + align:start position:0% +things that you can do you find that + + + align:start position:0% +things that you can do you find that +those more things are related to these + + align:start position:0% +those more things are related to these + + + align:start position:0% +those more things are related to these +things so you really want to construct a + + align:start position:0% +things so you really want to construct a + + + align:start position:0% +things so you really want to construct a +minimal basis and there's some things + + align:start position:0% +minimal basis and there's some things + + + align:start position:0% +minimal basis and there's some things +that go into doing that + + align:start position:0% + + + + align:start position:0% + +so at order P + + align:start position:0% +so at order P + + + align:start position:0% +so at order P +4th as I said we include both + + align:start position:0% +4th as I said we include both + + + align:start position:0% +4th as I said we include both +loops and those Loops will have terms + + align:start position:0% +loops and those Loops will have terms + + + align:start position:0% +loops and those Loops will have terms +like P 4th log mu ^2 over + + align:start position:0% + + + + align:start position:0% + +p^2 and we include terms like the L1 and + + align:start position:0% +p^2 and we include terms like the L1 and + + + align:start position:0% +p^2 and we include terms like the L1 and +L2 which are + + align:start position:0% + + + + align:start position:0% + +P to 4th type interactions once I take + + align:start position:0% +P to 4th type interactions once I take + + + align:start position:0% +P to 4th type interactions once I take +out the counter term the re normalized + + align:start position:0% +out the counter term the re normalized + + + align:start position:0% +out the counter term the re normalized +coupling is M dependent just like the + + align:start position:0% +coupling is M dependent just like the + + + align:start position:0% +coupling is M dependent just like the +gauge + + align:start position:0% + + + + align:start position:0% + +coupling this just comes from a + + align:start position:0% +coupling this just comes from a + + + align:start position:0% +coupling this just comes from a +fourpoint interaction with the + + align:start position:0% +fourpoint interaction with the + + + align:start position:0% +fourpoint interaction with the +Li and the M dependence by construction + + align:start position:0% +Li and the M dependence by construction + + + align:start position:0% +Li and the M dependence by construction +is canceled between these two + + align:start position:0% +is canceled between these two + + + align:start position:0% +is canceled between these two +things the Divergence is can from the + + align:start position:0% +things the Divergence is can from the + + + align:start position:0% +things the Divergence is can from the +loop is canceled by the counter term and + + align:start position:0% +loop is canceled by the counter term and + + + align:start position:0% +loop is canceled by the counter term and +of course spondingly the corresponding + + align:start position:0% +of course spondingly the corresponding + + + align:start position:0% +of course spondingly the corresponding +statement if you want to make it in + + align:start position:0% +statement if you want to make it in + + + align:start position:0% +statement if you want to make it in +terms of mu is that the MU dependence + + align:start position:0% +terms of mu is that the MU dependence + + + align:start position:0% +terms of mu is that the MU dependence +that is tightly tied to that one over + + align:start position:0% +that is tightly tied to that one over + + + align:start position:0% +that is tightly tied to that one over +Epsilon is canel and the normalized + + align:start position:0% + + + + align:start position:0% + +quantities okay so there's these two + + align:start position:0% +quantities okay so there's these two + + + align:start position:0% +quantities okay so there's these two +contributions they're both M dependent + + align:start position:0% +contributions they're both M dependent + + + align:start position:0% +contributions they're both M dependent +and that mut dependence + + align:start position:0% +and that mut dependence + + + align:start position:0% +and that mut dependence +cancels so the way that you should think + + align:start position:0% +cancels so the way that you should think + + + align:start position:0% +cancels so the way that you should think +of this is you should think mu is a cut + + align:start position:0% +of this is you should think mu is a cut + + + align:start position:0% +of this is you should think mu is a cut +is a cut off it's not a hard cut off but + + align:start position:0% +is a cut off it's not a hard cut off but + + + align:start position:0% +is a cut off it's not a hard cut off but +it is a + + align:start position:0% + + + + align:start position:0% + +cff and what the cut off is doing is + + align:start position:0% +cff and what the cut off is doing is + + + align:start position:0% +cff and what the cut off is doing is +dividing up infrared and UltraViolet + + align:start position:0% + + + + align:start position:0% + +physics in this case the low energy + + align:start position:0% +physics in this case the low energy + + + align:start position:0% +physics in this case the low energy +physics is in The Matrix elements in the + + align:start position:0% + + + + align:start position:0% + +loops where we have our propagating low + + align:start position:0% +loops where we have our propagating low + + + align:start position:0% +loops where we have our propagating low +energy degrees of freedom which are the + + align:start position:0% +energy degrees of freedom which are the + + + align:start position:0% +energy degrees of freedom which are the +pons and the high energy physics is in + + align:start position:0% +pons and the high energy physics is in + + + align:start position:0% +pons and the high energy physics is in +the + + align:start position:0% +the + + + align:start position:0% +the +coefficients as + + align:start position:0% + + + + align:start position:0% + +usual and they're both M dependence and + + align:start position:0% +usual and they're both M dependence and + + + align:start position:0% +usual and they're both M dependence and +you and you can think of that mut + + align:start position:0% +you and you can think of that mut + + + align:start position:0% +you and you can think of that mut +dependent as a cut off that divides up + + align:start position:0% +dependent as a cut off that divides up + + + align:start position:0% +dependent as a cut off that divides up +what how much of the physics goes into + + align:start position:0% +what how much of the physics goes into + + + align:start position:0% +what how much of the physics goes into +those low energy Loops how much of the + + align:start position:0% +those low energy Loops how much of the + + + align:start position:0% +those low energy Loops how much of the +physics goes into the + + align:start position:0% + + + + align:start position:0% + +coux so the difference between this and + + align:start position:0% +coux so the difference between this and + + + align:start position:0% +coux so the difference between this and +integrating out a mass of particle is is + + align:start position:0% +integrating out a mass of particle is is + + + align:start position:0% +integrating out a mass of particle is is +not the physics of where things go + + align:start position:0% +not the physics of where things go + + + align:start position:0% +not the physics of where things go +because the low energy physics always + + align:start position:0% +because the low energy physics always + + + align:start position:0% +because the low energy physics always +goes in The Matrix elements the high + + align:start position:0% +goes in The Matrix elements the high + + + align:start position:0% +goes in The Matrix elements the high +energy physics goes in the couplings the + + align:start position:0% +energy physics goes in the couplings the + + + align:start position:0% +energy physics goes in the couplings the +difference is that here we think that we + + align:start position:0% +difference is that here we think that we + + + align:start position:0% +difference is that here we think that we +can the way that you should think of it + + align:start position:0% +can the way that you should think of it + + + align:start position:0% +can the way that you should think of it +is that we can calculate the Matrix + + align:start position:0% +is that we can calculate the Matrix + + + align:start position:0% +is that we can calculate the Matrix +elements explicitly because our theory + + align:start position:0% +elements explicitly because our theory + + + align:start position:0% +elements explicitly because our theory +is in terms of the right degrees of + + align:start position:0% +is in terms of the right degrees of + + + align:start position:0% +is in terms of the right degrees of +freedom to describe longdistance + + align:start position:0% +freedom to describe longdistance + + + align:start position:0% +freedom to describe longdistance +physics which are the pons and then a + + align:start position:0% +physics which are the pons and then a + + + align:start position:0% +physics which are the pons and then a +coefficients are the unknowns that's the + + align:start position:0% +coefficients are the unknowns that's the + + + align:start position:0% +coefficients are the unknowns that's the +way in which it's + + align:start position:0% +way in which it's + + + align:start position:0% +way in which it's +different and that's really kind of the + + align:start position:0% +different and that's really kind of the + + + align:start position:0% +different and that's really kind of the +difference between bottom up and and top + + align:start position:0% + + + + align:start position:0% + +down + + align:start position:0% +down + + + align:start position:0% +down +so with that in + + align:start position:0% +so with that in + + + align:start position:0% +so with that in +mind if you want to think of what these + + align:start position:0% +mind if you want to think of what these + + + align:start position:0% +mind if you want to think of what these +couplings + + align:start position:0% +couplings + + + align:start position:0% +couplings +are if we just divide by f s just + + align:start position:0% + + + + align:start position:0% + +to then you can think about but + + align:start position:0% +to then you can think about but + + + align:start position:0% +to then you can think about but +dimensionally what they are in order for + + align:start position:0% +dimensionally what they are in order for + + + align:start position:0% +dimensionally what they are in order for +them to sort of match up with what we + + align:start position:0% +them to sort of match up with what we + + + align:start position:0% +them to sort of match up with what we +got from the loops is that they have + + align:start position:0% +got from the loops is that they have + + + align:start position:0% +got from the loops is that they have +some M + + align:start position:0% +some M + + + align:start position:0% +some M +dependence that looks like + + align:start position:0% +dependence that looks like + + + align:start position:0% +dependence that looks like +this you can think of it as + + align:start position:0% +this you can think of it as + + + align:start position:0% +this you can think of it as +parameterized by some coefficients A and + + align:start position:0% +parameterized by some coefficients A and + + + align:start position:0% +parameterized by some coefficients A and +B if I want to match up with the 4 Pi + + align:start position:0% +B if I want to match up with the 4 Pi + + + align:start position:0% +B if I want to match up with the 4 Pi +f^2 that comes from the loops then I + + align:start position:0% +f^2 that comes from the loops then I + + + align:start position:0% +f^2 that comes from the loops then I +have to sort of say that there's a 4 Pi + + align:start position:0% +have to sort of say that there's a 4 Pi + + + align:start position:0% +have to sort of say that there's a 4 Pi +hiding inside the + + align:start position:0% +hiding inside the + + + align:start position:0% +hiding inside the +Lis so I can do that and then there's + + align:start position:0% +Lis so I can do that and then there's + + + align:start position:0% +Lis so I can do that and then there's +some coefficients here there's some M + + align:start position:0% +some coefficients here there's some M + + + align:start position:0% +some coefficients here there's some M +dependence and the scales they're in the + + align:start position:0% +dependence and the scales they're in the + + + align:start position:0% +dependence and the scales they're in the +coefficients are the high scales like + + align:start position:0% +coefficients are the high scales like + + + align:start position:0% +coefficients are the high scales like +Lambda Kai and higher M row those types + + align:start position:0% +Lambda Kai and higher M row those types + + + align:start position:0% +Lambda Kai and higher M row those types +of things so let me just call it Lambda + + align:start position:0% +of things so let me just call it Lambda + + + align:start position:0% +of things so let me just call it Lambda +Kai and then there's some numbers a here + + align:start position:0% +Kai and then there's some numbers a here + + + align:start position:0% +Kai and then there's some numbers a here +A and B which encode you know the the H + + align:start position:0% +A and B which encode you know the the H + + + align:start position:0% +A and B which encode you know the the H +the high mass + + align:start position:0% +the high mass + + + align:start position:0% +the high mass +physics now the point of thinking about + + align:start position:0% +physics now the point of thinking about + + + align:start position:0% +physics now the point of thinking about +power counting is that thinking about + + align:start position:0% +power counting is that thinking about + + + align:start position:0% +power counting is that thinking about +the fact that the loops in these + + align:start position:0% +the fact that the loops in these + + + align:start position:0% +the fact that the loops in these +coefficients are the same size actually + + align:start position:0% +coefficients are the same size actually + + + align:start position:0% +coefficients are the same size actually +tells you that these Ai and bi should be + + align:start position:0% +tells you that these Ai and bi should be + + + align:start position:0% +tells you that these Ai and bi should be +order one + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +and this actually goes under the rubric + + align:start position:0% +and this actually goes under the rubric + + + align:start position:0% +and this actually goes under the rubric +of something called naive dimensional + + align:start position:0% + + + + align:start position:0% + +analysis so what na demential analysis + + align:start position:0% +analysis so what na demential analysis + + + align:start position:0% +analysis so what na demential analysis +say is that this cut off that we put + + align:start position:0% +say is that this cut off that we put + + + align:start position:0% +say is that this cut off that we put +between the low energy physics and the + + align:start position:0% +between the low energy physics and the + + + align:start position:0% +between the low energy physics and the +high energy physics is arbitrary and we + + align:start position:0% +high energy physics is arbitrary and we + + + align:start position:0% +high energy physics is arbitrary and we +could change it we could change it by a + + align:start position:0% +could change it we could change it by a + + + align:start position:0% +could change it we could change it by a +factor of two and what changing it does + + align:start position:0% +factor of two and what changing it does + + + align:start position:0% +factor of two and what changing it does +is it moves piece pieces back and forth + + align:start position:0% +is it moves piece pieces back and forth + + + align:start position:0% +is it moves piece pieces back and forth +but if we could move pieces back and + + align:start position:0% +but if we could move pieces back and + + + align:start position:0% +but if we could move pieces back and +forth then you wouldn't expect that the + + align:start position:0% +forth then you wouldn't expect that the + + + align:start position:0% +forth then you wouldn't expect that the +two things that you're talking about + + align:start position:0% +two things that you're talking about + + + align:start position:0% +two things that you're talking about +would be different in magnitude because + + align:start position:0% +would be different in magnitude because + + + align:start position:0% +would be different in magnitude because +we can we're allowed to move pieces back + + align:start position:0% +we can we're allowed to move pieces back + + + align:start position:0% +we can we're allowed to move pieces back +and forth so you expect that the size of + + align:start position:0% +and forth so you expect that the size of + + + align:start position:0% +and forth so you expect that the size of +contributions from the coefficients are + + align:start position:0% +contributions from the coefficients are + + + align:start position:0% +contributions from the coefficients are +about the same size as the loops and + + align:start position:0% +about the same size as the loops and + + + align:start position:0% +about the same size as the loops and +that's what naive diens that's this + + align:start position:0% +that's what naive diens that's this + + + align:start position:0% +that's what naive diens that's this +naive dimensional + + align:start position:0% +naive dimensional + + + align:start position:0% +naive dimensional +analysis so changing mu moves pieces + + align:start position:0% +analysis so changing mu moves pieces + + + align:start position:0% +analysis so changing mu moves pieces +back and + + align:start position:0% + + + + align:start position:0% + +forth the sum is Mu + + align:start position:0% + + + + align:start position:0% + +independent but each individual thing is + + align:start position:0% + + + + align:start position:0% + +not and because we're able to move + + align:start position:0% +not and because we're able to move + + + align:start position:0% +not and because we're able to move +things back and + + align:start position:0% +things back and + + + align:start position:0% +things back and +forth we expect them to be the same + + align:start position:0% +forth we expect them to be the same + + + align:start position:0% +forth we expect them to be the same +order in mag + + align:start position:0% + + + + align:start position:0% + +itude and that is this statement here + + align:start position:0% +itude and that is this statement here + + + align:start position:0% +itude and that is this statement here +that the + + align:start position:0% +that the + + + align:start position:0% +that the +AI and bis once I account for the four + + align:start position:0% +AI and bis once I account for the four + + + align:start position:0% +AI and bis once I account for the four +pies so I can actually with this + + align:start position:0% +pies so I can actually with this + + + align:start position:0% +pies so I can actually with this +argument I can figure out where there's + + align:start position:0% +argument I can figure out where there's + + + align:start position:0% +argument I can figure out where there's +where there's four pies hiding in the + + align:start position:0% +where there's four pies hiding in the + + + align:start position:0% +where there's four pies hiding in the +coefficients cuz I can identify four + + align:start position:0% +coefficients cuz I can identify four + + + align:start position:0% +coefficients cuz I can identify four +pies in loops and then if they're + + align:start position:0% +pies in loops and then if they're + + + align:start position:0% +pies in loops and then if they're +supposed to be the same size I can also + + align:start position:0% +supposed to be the same size I can also + + + align:start position:0% +supposed to be the same size I can also +identify four pies in + + align:start position:0% +identify four pies in + + + align:start position:0% +identify four pies in +coefficients so if you had if you had + + align:start position:0% +coefficients so if you had if you had + + + align:start position:0% +coefficients so if you had if you had +figured this out I don't know 20 years + + align:start position:0% +figured this out I don't know 20 years + + + align:start position:0% +figured this out I don't know 20 years +ago then you could have got a PhD thesis + + align:start position:0% +ago then you could have got a PhD thesis + + + align:start position:0% +ago then you could have got a PhD thesis +like Anish manahar did which was 25 + + align:start position:0% +like Anish manahar did which was 25 + + + align:start position:0% +like Anish manahar did which was 25 +pages + + align:start position:0% + + + + align:start position:0% + +long short PhD thesis do + + align:start position:0% + + + + align:start position:0% + +exist okay + + align:start position:0% +exist okay + + + align:start position:0% +exist okay +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +so what do we do in practice in practice + + align:start position:0% +so what do we do in practice in practice + + + align:start position:0% +so what do we do in practice in practice +we have to pick a value of mu just like + + align:start position:0% +we have to pick a value of mu just like + + + align:start position:0% +we have to pick a value of mu just like +in when we were talking about gauge + + align:start position:0% +in when we were talking about gauge + + + align:start position:0% +in when we were talking about gauge +Theory we need to pick a value of mu + + align:start position:0% +Theory we need to pick a value of mu + + + align:start position:0% +Theory we need to pick a value of mu +there we are picking things like mu + + align:start position:0% +there we are picking things like mu + + + align:start position:0% +there we are picking things like mu +equals + + align:start position:0% +equals + + + align:start position:0% +equals +MP here what people do is they typically + + align:start position:0% +MP here what people do is they typically + + + align:start position:0% +MP here what people do is they typically +pick M's that are high so maybe they + + align:start position:0% +pick M's that are high so maybe they + + + align:start position:0% +pick M's that are high so maybe they +would pick the Row Mass maybe they would + + align:start position:0% +would pick the Row Mass maybe they would + + + align:start position:0% +would pick the Row Mass maybe they would +pick Lambda Kai + + align:start position:0% +pick Lambda Kai + + + align:start position:0% +pick Lambda Kai +or they'd pick just that something in + + align:start position:0% +or they'd pick just that something in + + + align:start position:0% +or they'd pick just that something in +between like a GV these are typical + + align:start position:0% +between like a GV these are typical + + + align:start position:0% +between like a GV these are typical +values that people + + align:start position:0% +values that people + + + align:start position:0% +values that people +use so what that means is that you've + + align:start position:0% +use so what that means is that you've + + + align:start position:0% +use so what that means is that you've +put large logs you've removed all large + + align:start position:0% +put large logs you've removed all large + + + align:start position:0% +put large logs you've removed all large +logs from your coefficients and that's + + align:start position:0% +logs from your coefficients and that's + + + align:start position:0% +logs from your coefficients and that's +because you want dimensional analysis to + + align:start position:0% +because you want dimensional analysis to + + + align:start position:0% +because you want dimensional analysis to +hold for your coefficients because you + + align:start position:0% +hold for your coefficients because you + + + align:start position:0% +hold for your coefficients because you +don't know them so you would like to + + align:start position:0% +don't know them so you would like to + + + align:start position:0% +don't know them so you would like to +have some power counting estimate for + + align:start position:0% +have some power counting estimate for + + + align:start position:0% +have some power counting estimate for +them then you'd like to go out and fit + + align:start position:0% +them then you'd like to go out and fit + + + align:start position:0% +them then you'd like to go out and fit +them to data and you'd like the result + + align:start position:0% +them to data and you'd like the result + + + align:start position:0% +them to data and you'd like the result +that you get from fitting to the data to + + align:start position:0% +that you get from fitting to the data to + + + align:start position:0% +that you get from fitting to the data to +agree with your power counting estimate + + align:start position:0% +agree with your power counting estimate + + + align:start position:0% +agree with your power counting estimate +to be so that happy turns out that it + + align:start position:0% +to be so that happy turns out that it + + + align:start position:0% +to be so that happy turns out that it +does so you are + + align:start position:0% +does so you are + + + align:start position:0% +does so you are +happy and and So to avoid large logs in + + align:start position:0% +happy and and So to avoid large logs in + + + align:start position:0% +happy and and So to avoid large logs in +that the story you put the large logs + + align:start position:0% +that the story you put the large logs + + + align:start position:0% +that the story you put the large logs +into the Matrix + + align:start position:0% + + + + align:start position:0% + +elements so that's different than our + + align:start position:0% +elements so that's different than our + + + align:start position:0% +elements so that's different than our +story engage Theory where we were + + align:start position:0% +story engage Theory where we were + + + align:start position:0% +story engage Theory where we were +thinking that we would resum all the + + align:start position:0% +thinking that we would resum all the + + + align:start position:0% +thinking that we would resum all the +large logarithms in the coefficients and + + align:start position:0% +large logarithms in the coefficients and + + + align:start position:0% +large logarithms in the coefficients and +then our Matrix elements would also have + + align:start position:0% +then our Matrix elements would also have + + + align:start position:0% +then our Matrix elements would also have +no large logarithms here we're just + + align:start position:0% +no large logarithms here we're just + + + align:start position:0% +no large logarithms here we're just +saying well let's allow for large logs + + align:start position:0% +saying well let's allow for large logs + + + align:start position:0% +saying well let's allow for large logs +in The Matrix elements but the story is + + align:start position:0% +in The Matrix elements but the story is + + + align:start position:0% +in The Matrix elements but the story is +also different in from Gauge theory in + + align:start position:0% +also different in from Gauge theory in + + + align:start position:0% +also different in from Gauge theory in +another way which is that there's not an + + align:start position:0% +another way which is that there's not an + + + align:start position:0% +another way which is that there's not an +infinite series here of large logarithms + + align:start position:0% +infinite series here of large logarithms + + + align:start position:0% +infinite series here of large logarithms +that you need to resum + + align:start position:0% + + + + align:start position:0% + +and that's related to the fact that the + + align:start position:0% +and that's related to the fact that the + + + align:start position:0% +and that's related to the fact that the +kinetic term didn't get + + align:start position:0% +kinetic term didn't get + + + align:start position:0% +kinetic term didn't get +renormalized there's no M dependence in + + align:start position:0% +renormalized there's no M dependence in + + + align:start position:0% +renormalized there's no M dependence in +the coefficients of the kinetic term so + + align:start position:0% +the coefficients of the kinetic term so + + + align:start position:0% +the coefficients of the kinetic term so +when the loop graphs aren't having like + + align:start position:0% +when the loop graphs aren't having like + + + align:start position:0% +when the loop graphs aren't having like +uh coefficient squared depending on mu + + align:start position:0% +uh coefficient squared depending on mu + + + align:start position:0% +uh coefficient squared depending on mu +that doesn't happen we simply have one + + align:start position:0% +that doesn't happen we simply have one + + + align:start position:0% +that doesn't happen we simply have one +log in our Loop graphs One log from our + + align:start position:0% +log in our Loop graphs One log from our + + + align:start position:0% +log in our Loop graphs One log from our +counterterm diagrams they explicitly + + align:start position:0% +counterterm diagrams they explicitly + + + align:start position:0% +counterterm diagrams they explicitly +cancel there's no high order terms the + + align:start position:0% +cancel there's no high order terms the + + + align:start position:0% +cancel there's no high order terms the +normalization group here is a completely + + align:start position:0% +normalization group here is a completely + + + align:start position:0% +normalization group here is a completely +trivial if you integrate you just get + + align:start position:0% +trivial if you integrate you just get + + + align:start position:0% +trivial if you integrate you just get +one log so there's not really even a + + align:start position:0% +one log so there's not really even a + + + align:start position:0% +one log so there's not really even a +reason to talk about + + align:start position:0% +reason to talk about + + + align:start position:0% +reason to talk about +it okay so there's certainly some + + align:start position:0% +it okay so there's certainly some + + + align:start position:0% +it okay so there's certainly some +differences in this Theory than there + + align:start position:0% +differences in this Theory than there + + + align:start position:0% +differences in this Theory than there +are in gauge Theory + + align:start position:0% + + + + align:start position:0% + +and so typically the Paradigm that you + + align:start position:0% +and so typically the Paradigm that you + + + align:start position:0% +and so typically the Paradigm that you +have is you can calculate Matrix + + align:start position:0% +have is you can calculate Matrix + + + align:start position:0% +have is you can calculate Matrix +elements you're going to fit the + + align:start position:0% +elements you're going to fit the + + + align:start position:0% +elements you're going to fit the +coefficients you think of enough + + align:start position:0% +coefficients you think of enough + + + align:start position:0% +coefficients you think of enough +experiment such that you can get all the + + align:start position:0% +experiment such that you can get all the + + + align:start position:0% +experiment such that you can get all the +information about those coefficients and + + align:start position:0% +information about those coefficients and + + + align:start position:0% +information about those coefficients and +then you can think of other experiments + + align:start position:0% +then you can think of other experiments + + + align:start position:0% +then you can think of other experiments +and make + + align:start position:0% +and make + + + align:start position:0% +and make +predictions now as you go to higher + + align:start position:0% +predictions now as you go to higher + + + align:start position:0% +predictions now as you go to higher +orders in the theory you get more + + align:start position:0% +orders in the theory you get more + + + align:start position:0% +orders in the theory you get more +coefficients because you keep having to + + align:start position:0% +coefficients because you keep having to + + + align:start position:0% +coefficients because you keep having to +go to higher orders and construct higher + + align:start position:0% +go to higher orders and construct higher + + + align:start position:0% +go to higher orders and construct higher +Dimension + + align:start position:0% +Dimension + + + align:start position:0% +Dimension +operators um and so the Paradigm of + + align:start position:0% +operators um and so the Paradigm of + + + align:start position:0% +operators um and so the Paradigm of +figuring out how to fit the coefficients + + align:start position:0% +figuring out how to fit the coefficients + + + align:start position:0% +figuring out how to fit the coefficients +gets harder and harder and at some point + + align:start position:0% +gets harder and harder and at some point + + + align:start position:0% +gets harder and harder and at some point +you effectively lose predictive power + + align:start position:0% +you effectively lose predictive power + + + align:start position:0% +you effectively lose predictive power +because you can't think of enough + + align:start position:0% +because you can't think of enough + + + align:start position:0% +because you can't think of enough +observables that can be + + align:start position:0% +observables that can be + + + align:start position:0% +observables that can be +measured in order to fit all your + + align:start position:0% +measured in order to fit all your + + + align:start position:0% +measured in order to fit all your +coefficients but certainly at order P to + + align:start position:0% +coefficients but certainly at order P to + + + align:start position:0% +coefficients but certainly at order P to +the + + align:start position:0% +the + + + align:start position:0% +the +4th uh people can think of many more + + align:start position:0% +4th uh people can think of many more + + + align:start position:0% +4th uh people can think of many more +observables and actually people have + + align:start position:0% +observables and actually people have + + + align:start position:0% +observables and actually people have +worked out P to the + + align:start position:0% +worked out P to the + + + align:start position:0% +worked out P to the +6th as well + + align:start position:0% +6th as well + + + align:start position:0% +6th as well +[Applause] + + align:start position:0% + + + + align:start position:0% + +here so two Loop KY probation theory is + + align:start position:0% +here so two Loop KY probation theory is + + + align:start position:0% +here so two Loop KY probation theory is +kind of the state of the art + + align:start position:0% + + + + align:start position:0% + +yeah um + + align:start position:0% +yeah um + + + align:start position:0% +yeah um +why + + align:start position:0% + + + + align:start position:0% + +not yeah it's it's so you could it + + align:start position:0% +not yeah it's it's so you could it + + + align:start position:0% +not yeah it's it's so you could it +doesn't screw it up because it only + + align:start position:0% +doesn't screw it up because it only + + + align:start position:0% +doesn't screw it up because it only +happens once so there's no sense in + + align:start position:0% +happens once so there's no sense in + + + align:start position:0% +happens once so there's no sense in +which um so basically what you can say + + align:start position:0% +which um so basically what you can say + + + align:start position:0% +which um so basically what you can say +is you can say I have this Matrix + + align:start position:0% +is you can say I have this Matrix + + + align:start position:0% +is you can say I have this Matrix +element it's got a large log and a + + align:start position:0% +element it's got a large log and a + + + align:start position:0% +element it's got a large log and a +coefficient the coupling isn't it's not + + align:start position:0% +coefficient the coupling isn't it's not + + + align:start position:0% +coefficient the coupling isn't it's not +like large log times the coupling is of + + align:start position:0% +like large log times the coupling is of + + + align:start position:0% +like large log times the coupling is of +order something that you could count as + + align:start position:0% +order something that you could count as + + + align:start position:0% +order something that you could count as +order one because that's not going to + + align:start position:0% +order one because that's not going to + + + align:start position:0% +order one because that's not going to +reappear in the higher order when you go + + align:start position:0% +reappear in the higher order when you go + + + align:start position:0% +reappear in the higher order when you go +to the higher order so you still have a + + align:start position:0% +to the higher order so you still have a + + + align:start position:0% +to the higher order so you still have a +large log and you you are allowed to say + + align:start position:0% +large log and you you are allowed to say + + + align:start position:0% +large log and you you are allowed to say +that that large log is the most + + align:start position:0% +that that large log is the most + + + align:start position:0% +that that large log is the most +important piece of my Matrix element but + + align:start position:0% +important piece of my Matrix element but + + + align:start position:0% +important piece of my Matrix element but +it doesn't repeat itself in the higher + + align:start position:0% +it doesn't repeat itself in the higher + + + align:start position:0% +it doesn't repeat itself in the higher +orders because once you go to higher + + align:start position:0% +orders because once you go to higher + + + align:start position:0% +orders because once you go to higher +Loops you're just going to get you're + + align:start position:0% +Loops you're just going to get you're + + + align:start position:0% +Loops you're just going to get you're +actually getting something that's power + + align:start position:0% +actually getting something that's power + + + align:start position:0% +actually getting something that's power +suppressed not Loop + + align:start position:0% +suppressed not Loop + + + align:start position:0% +suppressed not Loop +suppressed so the loops are giving power + + align:start position:0% +suppressed so the loops are giving power + + + align:start position:0% +suppressed so the loops are giving power +suppression and that changes a lot of + + align:start position:0% +suppression and that changes a lot of + + + align:start position:0% +suppression and that changes a lot of +things + + align:start position:0% + + + + align:start position:0% + +okay what would happen if we used a hard + + align:start position:0% +okay what would happen if we used a hard + + + align:start position:0% +okay what would happen if we used a hard +cut + + align:start position:0% + + + + align:start position:0% + +off maybe some of this story would have + + align:start position:0% +off maybe some of this story would have + + + align:start position:0% +off maybe some of this story would have +be a bit more + + align:start position:0% +be a bit more + + + align:start position:0% +be a bit more +transparent if we'd done that because + + align:start position:0% +transparent if we'd done that because + + + align:start position:0% +transparent if we'd done that because +we'd see that we were explicitly + + align:start position:0% +we'd see that we were explicitly + + + align:start position:0% +we'd see that we were explicitly +dividing up low energy and high energy + + align:start position:0% +dividing up low energy and high energy + + + align:start position:0% +dividing up low energy and high energy +physics but there's a price to pay for + + align:start position:0% +physics but there's a price to pay for + + + align:start position:0% +physics but there's a price to pay for +that + + align:start position:0% +that + + + align:start position:0% +that +transparency and here effectively + + align:start position:0% +transparency and here effectively + + + align:start position:0% +transparency and here effectively +everybody decides it's too high a price + + align:start position:0% +everybody decides it's too high a price + + + align:start position:0% +everybody decides it's too high a price +to pay and so they use dim rag + + align:start position:0% +to pay and so they use dim rag + + + align:start position:0% +to pay and so they use dim rag +so what type of prices would you pay so + + align:start position:0% +so what type of prices would you pay so + + + align:start position:0% +so what type of prices would you pay so +if you did that this Loop here would + + align:start position:0% +if you did that this Loop here would + + + align:start position:0% +if you did that this Loop here would +actually have terms that are cut off to + + align:start position:0% +actually have terms that are cut off to + + + align:start position:0% +actually have terms that are cut off to +the fourth over Lambda Kai to the 4th + + align:start position:0% +the fourth over Lambda Kai to the 4th + + + align:start position:0% +the fourth over Lambda Kai to the 4th +and that guy breaks chyro + + align:start position:0% +and that guy breaks chyro + + + align:start position:0% +and that guy breaks chyro +symmetry there's no term I mean it's + + align:start position:0% +symmetry there's no term I mean it's + + + align:start position:0% +symmetry there's no term I mean it's +giving a constant term and you're not + + align:start position:0% +giving a constant term and you're not + + + align:start position:0% +giving a constant term and you're not +seeing the derivative coupling and that + + align:start position:0% +seeing the derivative coupling and that + + + align:start position:0% +seeing the derivative coupling and that +means effectively that there's no + + align:start position:0% +means effectively that there's no + + + align:start position:0% +means effectively that there's no +counter term to absorb this dependence + + align:start position:0% +counter term to absorb this dependence + + + align:start position:0% +counter term to absorb this dependence +in our alai because our alai respected + + align:start position:0% +in our alai because our alai respected + + + align:start position:0% +in our alai because our alai respected +car + + align:start position:0% +car + + + align:start position:0% +car +symmetry so that's kind of + + align:start position:0% +symmetry so that's kind of + + + align:start position:0% +symmetry so that's kind of +bad if you had a cut off you'd also get + + align:start position:0% +bad if you had a cut off you'd also get + + + align:start position:0% +bad if you had a cut off you'd also get +terms that meant like cut off squar time + + align:start position:0% +terms that meant like cut off squar time + + + align:start position:0% +terms that meant like cut off squar time +momentum squared where two powers of the + + align:start position:0% +momentum squared where two powers of the + + + align:start position:0% +momentum squared where two powers of the +P are replaced by cut off and that in + + align:start position:0% +P are replaced by cut off and that in + + + align:start position:0% +P are replaced by cut off and that in +this language that we used earlier would + + align:start position:0% +this language that we used earlier would + + + align:start position:0% +this language that we used earlier would +break the power counting in the sense + + align:start position:0% +break the power counting in the sense + + + align:start position:0% +break the power counting in the sense +that we have a power counting that says + + align:start position:0% +that we have a power counting that says + + + align:start position:0% +that we have a power counting that says +that the loops should be suppressed by P + + align:start position:0% +that the loops should be suppressed by P + + + align:start position:0% +that the loops should be suppressed by P +to the 4th and it's broken by this and + + align:start position:0% +to the 4th and it's broken by this and + + + align:start position:0% +to the 4th and it's broken by this and +then then you would need to absorb + + align:start position:0% +then then you would need to absorb + + + align:start position:0% +then then you would need to absorb +that and renormalize your leading water + + align:start position:0% +that and renormalize your leading water + + + align:start position:0% +that and renormalize your leading water +coupling + + align:start position:0% +coupling + + + align:start position:0% +coupling +but effectively all the re normalization + + align:start position:0% +but effectively all the re normalization + + + align:start position:0% +but effectively all the re normalization +would be doing is restoring your power + + align:start position:0% +would be doing is restoring your power + + + align:start position:0% +would be doing is restoring your power +counting it's not doing something that + + align:start position:0% +counting it's not doing something that + + + align:start position:0% +counting it's not doing something that +you should interpret as really a + + align:start position:0% +you should interpret as really a + + + align:start position:0% +you should interpret as really a +physical + + align:start position:0% + + + + align:start position:0% + +thing so it's just a something to be + + align:start position:0% +thing so it's just a something to be + + + align:start position:0% +thing so it's just a something to be +avoided and then + + align:start position:0% +avoided and then + + + align:start position:0% +avoided and then +finally the physics that you actually + + align:start position:0% +finally the physics that you actually + + + align:start position:0% +finally the physics that you actually +want which is the logs of the of the cut + + align:start position:0% + + + + align:start position:0% + +off would also be there and you would do + + align:start position:0% +off would also be there and you would do + + + align:start position:0% +off would also be there and you would do +the same thing + + align:start position:0% + + + + align:start position:0% + +as you do in dim rag You' absorb that in + + align:start position:0% +as you do in dim rag You' absorb that in + + + align:start position:0% +as you do in dim rag You' absorb that in +the higher + + align:start position:0% +the higher + + + align:start position:0% +the higher +Dimension + + align:start position:0% +Dimension + + + align:start position:0% +Dimension +operators okay so we won't use a cut off + + align:start position:0% +operators okay so we won't use a cut off + + + align:start position:0% +operators okay so we won't use a cut off +because we don't want to think about + + align:start position:0% +because we don't want to think about + + + align:start position:0% +because we don't want to think about +things that are breaking power counting + + align:start position:0% +things that are breaking power counting + + + align:start position:0% +things that are breaking power counting +or messing up car + + align:start position:0% + + + + align:start position:0% + +symmetry another thing that's different + + align:start position:0% +symmetry another thing that's different + + + align:start position:0% +symmetry another thing that's different +about Carl theories versus gauge + + align:start position:0% +about Carl theories versus gauge + + + align:start position:0% +about Carl theories versus gauge +theories is the structure of infrared + + align:start position:0% +theories is the structure of infrared + + + align:start position:0% +theories is the structure of infrared +divergences + + align:start position:0% +divergences + + + align:start position:0% +divergences +and that's because you have derivative + + align:start position:0% + + + + align:start position:0% + +couplings so you have many fewer uh + + align:start position:0% +couplings so you have many fewer uh + + + align:start position:0% +couplings so you have many fewer uh +infrared singularities than you have in + + align:start position:0% +infrared singularities than you have in + + + align:start position:0% +infrared singularities than you have in +in Gage Theory and in fact you usually + + align:start position:0% +in Gage Theory and in fact you usually + + + align:start position:0% +in Gage Theory and in fact you usually +don't have + + align:start position:0% + + + + align:start position:0% + +any and one way of describing that is + + align:start position:0% +any and one way of describing that is + + + align:start position:0% +any and one way of describing that is +that you usually have a good M pi^ squ + + align:start position:0% +that you usually have a good M pi^ squ + + + align:start position:0% +that you usually have a good M pi^ squ +goes to zero or p^2 goes to zero limit + + align:start position:0% +goes to zero or p^2 goes to zero limit + + + align:start position:0% +goes to zero or p^2 goes to zero limit +of your + + align:start position:0% + + + + align:start position:0% + +results so you can just explicitly take + + align:start position:0% +results so you can just explicitly take + + + align:start position:0% +results so you can just explicitly take +these + + align:start position:0% +these + + + align:start position:0% +these +limits and talk about the results in + + align:start position:0% +limits and talk about the results in + + + align:start position:0% +limits and talk about the results in +those + + align:start position:0% +those + + + align:start position:0% +those +limits and you know if you look back at + + align:start position:0% +limits and you know if you look back at + + + align:start position:0% +limits and you know if you look back at +what we were talking about it's like you + + align:start position:0% +what we were talking about it's like you + + + align:start position:0% +what we were talking about it's like you +get P to the 4th log p s so there's a p + + align:start position:0% +get P to the 4th log p s so there's a p + + + align:start position:0% +get P to the 4th log p s so there's a p +to 4th multiplying the log p^ s so + + align:start position:0% +to 4th multiplying the log p^ s so + + + align:start position:0% +to 4th multiplying the log p^ s so +you're not seeing log P squ blow up + + align:start position:0% +you're not seeing log P squ blow up + + + align:start position:0% +you're not seeing log P squ blow up +because it's got so many powers of P + + align:start position:0% +because it's got so many powers of P + + + align:start position:0% +because it's got so many powers of P +multiplying + + align:start position:0% + + + + align:start position:0% + +it Although our focuses on formalism I + + align:start position:0% +it Although our focuses on formalism I + + + align:start position:0% +it Although our focuses on formalism I +have to at least give you one example of + + align:start position:0% +have to at least give you one example of + + + align:start position:0% +have to at least give you one example of +something predictive and + + align:start position:0% +something predictive and + + + align:start position:0% +something predictive and +phenomenological + + align:start position:0% + + + + align:start position:0% + +so Pi Pi scattering is a nice example of + + align:start position:0% +so Pi Pi scattering is a nice example of + + + align:start position:0% +so Pi Pi scattering is a nice example of +phenomenology and it's particularly nice + + align:start position:0% +phenomenology and it's particularly nice + + + align:start position:0% +phenomenology and it's particularly nice +if you look at it below in elastic + + align:start position:0% +if you look at it below in elastic + + + align:start position:0% +if you look at it below in elastic +thresholds so you just have elastic + + align:start position:0% + + + + align:start position:0% + +scattering so you could look at Pi Pi + + align:start position:0% +scattering so you could look at Pi Pi + + + align:start position:0% +scattering so you could look at Pi Pi +goes to 4 pi and that's something you + + align:start position:0% +goes to 4 pi and that's something you + + + align:start position:0% +goes to 4 pi and that's something you +could actually look at in car peration + + align:start position:0% +could actually look at in car peration + + + align:start position:0% +could actually look at in car peration +Theory but it's if we look at just Pi Pi + + align:start position:0% +Theory but it's if we look at just Pi Pi + + + align:start position:0% +Theory but it's if we look at just Pi Pi +goes to Pi Pi where we have not enough + + align:start position:0% +goes to Pi Pi where we have not enough + + + align:start position:0% +goes to Pi Pi where we have not enough +energy to produce four + + align:start position:0% +energy to produce four + + + align:start position:0% +energy to produce four +pons + + align:start position:0% +pons + + + align:start position:0% +pons +then the scattering is particularly + + align:start position:0% +then the scattering is particularly + + + align:start position:0% +then the scattering is particularly +simple it's just described by an S + + align:start position:0% +simple it's just described by an S + + + align:start position:0% +simple it's just described by an S +Matrix which we can enumerate Channel by + + align:start position:0% +Matrix which we can enumerate Channel by + + + align:start position:0% +Matrix which we can enumerate Channel by +Channel and it's just a phase + + align:start position:0% + + + + align:start position:0% + +where this L is a partial + + align:start position:0% +where this L is a partial + + + align:start position:0% +where this L is a partial +wave + + align:start position:0% +wave + + + align:start position:0% +wave +phase and the I is an isos + + align:start position:0% +phase and the I is an isos + + + align:start position:0% +phase and the I is an isos +spin so for each isospin and for each + + align:start position:0% +spin so for each isospin and for each + + + align:start position:0% +spin so for each isospin and for each +angular momentum State we got different + + align:start position:0% +angular momentum State we got different + + + align:start position:0% +angular momentum State we got different +phases but those are that's encoding all + + align:start position:0% +phases but those are that's encoding all + + + align:start position:0% +phases but those are that's encoding all +the + + align:start position:0% +the + + + align:start position:0% +the +scattering so it's like doing + + align:start position:0% +scattering so it's like doing + + + align:start position:0% +scattering so it's like doing +non-relativistic scattering + + align:start position:0% +non-relativistic scattering + + + align:start position:0% +non-relativistic scattering +or very simple quad mechanical + + align:start position:0% +or very simple quad mechanical + + + align:start position:0% +or very simple quad mechanical +scattering + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +and when you have an elastic scattering + + align:start position:0% +and when you have an elastic scattering + + + align:start position:0% +and when you have an elastic scattering +like that there's something called the + + align:start position:0% +like that there's something called the + + + align:start position:0% +like that there's something called the +effect of range + + align:start position:0% +effect of range + + + align:start position:0% +effect of range +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +expansion which is a derivative + + align:start position:0% +expansion which is a derivative + + + align:start position:0% +expansion which is a derivative +expansion for the phase shift + + align:start position:0% +expansion for the phase shift + + + align:start position:0% +expansion for the phase shift +Delta and if you do it for an arbitrary + + align:start position:0% +Delta and if you do it for an arbitrary + + + align:start position:0% +Delta and if you do it for an arbitrary +partial wave this is how it looks so + + align:start position:0% +partial wave this is how it looks so + + + align:start position:0% +partial wave this is how it looks so +this is again something that you would + + align:start position:0% +this is again something that you would + + + align:start position:0% +this is again something that you would +find in a discussion of scattering + + align:start position:0% +find in a discussion of scattering + + + align:start position:0% +find in a discussion of scattering +theory in quantum + + align:start position:0% + + + + align:start position:0% + +mechanics and you have a derivative + + align:start position:0% +mechanics and you have a derivative + + + align:start position:0% +mechanics and you have a derivative +expansion of this quantity p 2 L +1 Cen + + align:start position:0% +expansion of this quantity p 2 L +1 Cen + + + align:start position:0% +expansion of this quantity p 2 L +1 Cen +of that phase + + align:start position:0% +of that phase + + + align:start position:0% +of that phase +shift and the A's + + align:start position:0% + + + + align:start position:0% + +here and the r0 depend on what Channel + + align:start position:0% +here and the r0 depend on what Channel + + + align:start position:0% +here and the r0 depend on what Channel +you're talking + + align:start position:0% +you're talking + + + align:start position:0% +you're talking +about and if we actually just take the + + align:start position:0% +about and if we actually just take the + + + align:start position:0% +about and if we actually just take the +fact that we can C so this is a + + align:start position:0% +fact that we can C so this is a + + + align:start position:0% +fact that we can C so this is a +description from Quant mechanics it's + + align:start position:0% +description from Quant mechanics it's + + + align:start position:0% +description from Quant mechanics it's +just true irrespective of what theory + + align:start position:0% +just true irrespective of what theory + + + align:start position:0% +just true irrespective of what theory +you're talking about as long as you + + align:start position:0% +you're talking about as long as you + + + align:start position:0% +you're talking about as long as you +don't have uh other channels you can + + align:start position:0% +don't have uh other channels you can + + + align:start position:0% +don't have uh other channels you can +produce if you talk about it from K + + align:start position:0% +produce if you talk about it from K + + + align:start position:0% +produce if you talk about it from K +peration Theory though we could just + + align:start position:0% +peration Theory though we could just + + + align:start position:0% +peration Theory though we could just +calculate Pi Pi goes to Pi + + align:start position:0% +calculate Pi Pi goes to Pi + + + align:start position:0% +calculate Pi Pi goes to Pi +Pi and if you do that which Weinberg + + align:start position:0% + + + + align:start position:0% + +did then you just get results for these + + align:start position:0% + + + + align:start position:0% + +coefficients so I'll just quote a couple + + align:start position:0% +coefficients so I'll just quote a couple + + + align:start position:0% +coefficients so I'll just quote a couple +of them to you + + align:start position:0% + + + + align:start position:0% + +so you just get parameter free results + + align:start position:0% +so you just get parameter free results + + + align:start position:0% +so you just get parameter free results +parameter free in the sense that they + + align:start position:0% +parameter free in the sense that they + + + align:start position:0% +parameter free in the sense that they +just involve M pi and this thing F this + + align:start position:0% +just involve M pi and this thing F this + + + align:start position:0% +just involve M pi and this thing F this +thing f is actually measured by pi on + + align:start position:0% +thing f is actually measured by pi on + + + align:start position:0% +thing f is actually measured by pi on +Decay so it's not an unknown and then + + align:start position:0% +Decay so it's not an unknown and then + + + align:start position:0% +Decay so it's not an unknown and then +from that at lowest order in ch peration + + align:start position:0% +from that at lowest order in ch peration + + + align:start position:0% +from that at lowest order in ch peration +Theory you have no parameters once you + + align:start position:0% +Theory you have no parameters once you + + + align:start position:0% +Theory you have no parameters once you +fixed M pi and F pi and you can just + + align:start position:0% +fixed M pi and F pi and you can just + + + align:start position:0% +fixed M pi and F pi and you can just +make predictions for these scattering + + align:start position:0% +make predictions for these scattering + + + align:start position:0% +make predictions for these scattering +lengths and those are the + + align:start position:0% +lengths and those are the + + + align:start position:0% +lengths and those are the +predictions and they're parameter + + align:start position:0% + + + + align:start position:0% + +free in in the sense that I just + + align:start position:0% + + + + align:start position:0% + +said okay so that gives you some of the + + align:start position:0% +said okay so that gives you some of the + + + align:start position:0% +said okay so that gives you some of the +idea of what car pration Theory can do + + align:start position:0% +idea of what car pration Theory can do + + + align:start position:0% +idea of what car pration Theory can do +for you + + align:start position:0% + + + + align:start position:0% + +okay so let's talk about back to + + align:start position:0% +okay so let's talk about back to + + + align:start position:0% +okay so let's talk about back to +formalism there's many more + + align:start position:0% +formalism there's many more + + + align:start position:0% +formalism there's many more +phenomenological examples you could do + + align:start position:0% +phenomenological examples you could do + + + align:start position:0% +phenomenological examples you could do +but that's not our Focus back to + + align:start position:0% +but that's not our Focus back to + + + align:start position:0% +but that's not our Focus back to +formalism and back to + + align:start position:0% +formalism and back to + + + align:start position:0% +formalism and back to +this general power counting + + align:start position:0% + + + + align:start position:0% + +discussion so let's consider an + + align:start position:0% +discussion so let's consider an + + + align:start position:0% +discussion so let's consider an +arbitrary diagram in this Theory this + + align:start position:0% +arbitrary diagram in this Theory this + + + align:start position:0% +arbitrary diagram in this Theory this +Carl peration Theory + + align:start position:0% + + + + align:start position:0% + +and let's enumerate some pieces of that + + align:start position:0% + + + + align:start position:0% + +diagram so we'll say that it has some + + align:start position:0% +diagram so we'll say that it has some + + + align:start position:0% +diagram so we'll say that it has some +number of vertices we just count how + + align:start position:0% +number of vertices we just count how + + + align:start position:0% +number of vertices we just count how +many times I've inserted vertices from + + align:start position:0% +many times I've inserted vertices from + + + align:start position:0% +many times I've inserted vertices from +the + + align:start position:0% +the + + + align:start position:0% +the +Lans and I'll call that + + align:start position:0% +Lans and I'll call that + + + align:start position:0% +Lans and I'll call that +NV some number of internal + + align:start position:0% + + + + align:start position:0% + +lines call ni some number of x external + + align:start position:0% + + + + align:start position:0% + +lines the external lines are all + + align:start position:0% + + + + align:start position:0% + +pons that's what our theory is + + align:start position:0% +pons that's what our theory is + + + align:start position:0% +pons that's what our theory is +describing could be chons and natas if + + align:start position:0% +describing could be chons and natas if + + + align:start position:0% +describing could be chons and natas if +we're doing + + align:start position:0% +we're doing + + + align:start position:0% +we're doing +su3 and then some number of + + align:start position:0% +su3 and then some number of + + + align:start position:0% +su3 and then some number of +Loops so we have an integer associated + + align:start position:0% +Loops so we have an integer associated + + + align:start position:0% +Loops so we have an integer associated +with each of these + + align:start position:0% +with each of these + + + align:start position:0% +with each of these +things and when I talk about vertices I + + align:start position:0% +things and when I talk about vertices I + + + align:start position:0% +things and when I talk about vertices I +don't want to restrict myself just to + + align:start position:0% +don't want to restrict myself just to + + + align:start position:0% +don't want to restrict myself just to +the leading order vertices I want to + + align:start position:0% +the leading order vertices I want to + + + align:start position:0% +the leading order vertices I want to +talk about also these Lis and higher + + align:start position:0% +talk about also these Lis and higher + + + align:start position:0% +talk about also these Lis and higher +order vertices as well so let me have a + + align:start position:0% +order vertices as well so let me have a + + + align:start position:0% +order vertices as well so let me have a +notation for that where I take this + + align:start position:0% +notation for that where I take this + + + align:start position:0% +notation for that where I take this +integer NV which counts all vertices and + + align:start position:0% +integer NV which counts all vertices and + + + align:start position:0% +integer NV which counts all vertices and +split it into pieces that count the + + align:start position:0% +split it into pieces that count the + + + align:start position:0% +split it into pieces that count the +vertices at each of those different + + align:start position:0% +vertices at each of those different + + + align:start position:0% +vertices at each of those different +orders in the expansion in + + align:start position:0% + + + + align:start position:0% + +P so NN is the number of vertices that + + align:start position:0% +P so NN is the number of vertices that + + + align:start position:0% +P so NN is the number of vertices that +are order P to the n + + align:start position:0% +are order P to the n + + + align:start position:0% +are order P to the n +or M pi to the N or combinations of P P + + align:start position:0% +or M pi to the N or combinations of P P + + + align:start position:0% +or M pi to the N or combinations of P P +and M pi to the + + align:start position:0% +and M pi to the + + + align:start position:0% +and M pi to the +N but n of them all right so hopefully + + align:start position:0% +N but n of them all right so hopefully + + + align:start position:0% +N but n of them all right so hopefully +that's clear so if I have two insertions + + align:start position:0% +that's clear so if I have two insertions + + + align:start position:0% +that's clear so if I have two insertions +of the leading or L Grine and one + + align:start position:0% +of the leading or L Grine and one + + + align:start position:0% +of the leading or L Grine and one +insertion of the subleading then N Sub + + align:start position:0% +insertion of the subleading then N Sub + + + align:start position:0% +insertion of the subleading then N Sub +Zer would be two and N Sub one would be + + align:start position:0% +Zer would be two and N Sub one would be + + + align:start position:0% +Zer would be two and N Sub one would be +one and the total would be three that's + + align:start position:0% +one and the total would be three that's + + + align:start position:0% +one and the total would be three that's +what this notation means + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +so we'll assume we're using a regulator + + align:start position:0% +so we'll assume we're using a regulator + + + align:start position:0% +so we'll assume we're using a regulator +like dimensional regularization so we + + align:start position:0% +like dimensional regularization so we + + + align:start position:0% +like dimensional regularization so we +don't have to worry about the regulator + + align:start position:0% +don't have to worry about the regulator + + + align:start position:0% +don't have to worry about the regulator +messing up power counting and basically + + align:start position:0% +messing up power counting and basically + + + align:start position:0% +messing up power counting and basically +that means we could ignore the regulator + + align:start position:0% +that means we could ignore the regulator + + + align:start position:0% +that means we could ignore the regulator +as far as this discussion is concerned + + align:start position:0% +as far as this discussion is concerned + + + align:start position:0% +as far as this discussion is concerned +and we just count + + align:start position:0% + + + + align:start position:0% + +and effectively we can just count Mass + + align:start position:0% + + + + align:start position:0% + +Dimension so we'll count lambai + + align:start position:0% + + + + align:start position:0% + +factors let's think about it that + + align:start position:0% + + + + align:start position:0% + +way and we'll think about counting + + align:start position:0% +way and we'll think about counting + + + align:start position:0% +way and we'll think about counting +lambai factors for Matrix + + align:start position:0% + + + + align:start position:0% + +element a matrix element that I'll call + + align:start position:0% +element a matrix element that I'll call + + + align:start position:0% +element a matrix element that I'll call +Curly M which has + + align:start position:0% +Curly M which has + + + align:start position:0% +Curly M which has +NE external p + + align:start position:0% + + + + align:start position:0% + +so NE lines are poking out of + + align:start position:0% + + + + align:start position:0% + +it so then if we look at the + + align:start position:0% +it so then if we look at the + + + align:start position:0% +it so then if we look at the +vertices we can count how many P factors + + align:start position:0% +vertices we can count how many P factors + + + align:start position:0% +vertices we can count how many P factors +of Lambda Kai there is and I'm counting + + align:start position:0% +of Lambda Kai there is and I'm counting + + + align:start position:0% +of Lambda Kai there is and I'm counting +all dimensionful I'm turning all + + align:start position:0% +all dimensionful I'm turning all + + + align:start position:0% +all dimensionful I'm turning all +dimensionful things into Lambda + + align:start position:0% + + + + align:start position:0% + +Kai and so each different + + align:start position:0% +Kai and so each different + + + align:start position:0% +Kai and so each different +order and N gets a different number of + + align:start position:0% +order and N gets a different number of + + + align:start position:0% +order and N gets a different number of +Lambda kis because we even saw that + + align:start position:0% +Lambda kis because we even saw that + + + align:start position:0% +Lambda kis because we even saw that +already in the examples we treated where + + align:start position:0% +already in the examples we treated where + + + align:start position:0% +already in the examples we treated where +we got f^ s from the leading order but + + align:start position:0% +we got f^ s from the leading order but + + + align:start position:0% +we got f^ s from the leading order but +um from the subing we got Li and that + + align:start position:0% +um from the subing we got Li and that + + + align:start position:0% +um from the subing we got Li and that +was + + align:start position:0% +was + + + align:start position:0% +was +dimensionless so for Nal 2 which is the + + align:start position:0% +dimensionless so for Nal 2 which is the + + + align:start position:0% +dimensionless so for Nal 2 which is the +leading order + + align:start position:0% +leading order + + + align:start position:0% +leading order +here uh leading order was p^ S I said + + align:start position:0% +here uh leading order was p^ S I said + + + align:start position:0% +here uh leading order was p^ S I said +that quite not quite right minute ago so + + align:start position:0% +that quite not quite right minute ago so + + + align:start position:0% +that quite not quite right minute ago so +lowest order is is p^2 Nal 2 + + align:start position:0% + + + + align:start position:0% + +l0 and that had an f^ squ and that comes + + align:start position:0% +l0 and that had an f^ squ and that comes + + + align:start position:0% +l0 and that had an f^ squ and that comes +out if I just have 4 - 2 that's 2 Nal 4 + + align:start position:0% +out if I just have 4 - 2 that's 2 Nal 4 + + + align:start position:0% +out if I just have 4 - 2 that's 2 Nal 4 +that was giving our l i which were + + align:start position:0% +that was giving our l i which were + + + align:start position:0% +that was giving our l i which were +dimensionless okay so you can see the + + align:start position:0% +dimensionless okay so you can see the + + + align:start position:0% +dimensionless okay so you can see the +formula working and if we went to higher + + align:start position:0% +formula working and if we went to higher + + + align:start position:0% +formula working and if we went to higher +orders in the derivative and chyal + + align:start position:0% +orders in the derivative and chyal + + + align:start position:0% +orders in the derivative and chyal +expansion then we'd start getting Lambda + + align:start position:0% +expansion then we'd start getting Lambda + + + align:start position:0% +expansion then we'd start getting Lambda +kis in the + + align:start position:0% + + + + align:start position:0% + +denominator so this is just counting + + align:start position:0% +denominator so this is just counting + + + align:start position:0% +denominator so this is just counting +from the vertices which you should think + + align:start position:0% +from the vertices which you should think + + + align:start position:0% +from the vertices which you should think +of as Counting + + align:start position:0% +of as Counting + + + align:start position:0% +of as Counting +just from the prefactors in the lran + + align:start position:0% +just from the prefactors in the lran + + + align:start position:0% +just from the prefactors in the lran +there's also + + align:start position:0% +there's also + + + align:start position:0% +there's also +FS that come with the + + align:start position:0% + + + + align:start position:0% + +pons because every factor of the pon + + align:start position:0% +pons because every factor of the pon + + + align:start position:0% +pons because every factor of the pon +field comes with a factor of + + align:start position:0% +field comes with a factor of + + + align:start position:0% +field comes with a factor of +f you always have pi over F and I'm + + align:start position:0% +f you always have pi over F and I'm + + + align:start position:0% +f you always have pi over F and I'm +turning F into 4 Pi f for this + + align:start position:0% +turning F into 4 Pi f for this + + + align:start position:0% +turning F into 4 Pi f for this +discussion I'm not worrying about the + + align:start position:0% +discussion I'm not worrying about the + + + align:start position:0% +discussion I'm not worrying about the +four Pi you can you could do a more + + align:start position:0% +four Pi you can you could do a more + + + align:start position:0% +four Pi you can you could do a more +fancy version of this where you worry + + align:start position:0% +fancy version of this where you worry + + + align:start position:0% +fancy version of this where you worry +about the four pies but let's just focus + + align:start position:0% +about the four pies but let's just focus + + + align:start position:0% +about the four pies but let's just focus +on the + + align:start position:0% +on the + + + align:start position:0% +on the +dimensions so if you have a internal + + align:start position:0% +dimensions so if you have a internal + + + align:start position:0% +dimensions so if you have a internal +line that's contraction of two Pon + + align:start position:0% +line that's contraction of two Pon + + + align:start position:0% +line that's contraction of two Pon +Fields so that gets two fs and an + + align:start position:0% +Fields so that gets two fs and an + + + align:start position:0% +Fields so that gets two fs and an +external line is just one p field so + + align:start position:0% +external line is just one p field so + + + align:start position:0% +external line is just one p field so +that just gets + + align:start position:0% + + + + align:start position:0% + +one topologically these these different + + align:start position:0% +one topologically these these different + + + align:start position:0% +one topologically these these different +things that we enumerated are not + + align:start position:0% +things that we enumerated are not + + + align:start position:0% +things that we enumerated are not +unrelated so the oil identity tells us + + align:start position:0% +unrelated so the oil identity tells us + + + align:start position:0% +unrelated so the oil identity tells us +that the number of internal + + align:start position:0% +that the number of internal + + + align:start position:0% +that the number of internal +lines is the number of Loops plus the + + align:start position:0% +lines is the number of Loops plus the + + + align:start position:0% +lines is the number of Loops plus the +number of + + align:start position:0% +number of + + + align:start position:0% +number of +vertices minus + + align:start position:0% +vertices minus + + + align:start position:0% +vertices minus +one and so we use that to get rid of + + align:start position:0% + + + + align:start position:0% + +Ni so then we can just put these things + + align:start position:0% +Ni so then we can just put these things + + + align:start position:0% +Ni so then we can just put these things +together so + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +so if I get rid of Ni I here then I + + align:start position:0% +so if I get rid of Ni I here then I + + + align:start position:0% +so if I get rid of Ni I here then I +replace it by NL so that's that term I + + align:start position:0% +replace it by NL so that's that term I + + + align:start position:0% +replace it by NL so that's that term I +replace it + + align:start position:0% +replace it + + + align:start position:0% +replace it +by a sum over the nns which is the + + align:start position:0% +by a sum over the nns which is the + + + align:start position:0% +by a sum over the nns which is the +vertices and then this gives me a plus + + align:start position:0% + + + + align:start position:0% + +two okay now that's not the dimension of + + align:start position:0% +two okay now that's not the dimension of + + + align:start position:0% +two okay now that's not the dimension of +the left hand side that's just the DI + + align:start position:0% +the left hand side that's just the DI + + + align:start position:0% +the left hand side that's just the DI +mention of the ingredients there's also + + align:start position:0% +mention of the ingredients there's also + + + align:start position:0% +mention of the ingredients there's also +things that are coming from factors of + + align:start position:0% +things that are coming from factors of + + + align:start position:0% +things that are coming from factors of +Mi Pi or factors of of p and let me just + + align:start position:0% +Mi Pi or factors of of p and let me just + + + align:start position:0% +Mi Pi or factors of of p and let me just +call that + + align:start position:0% +call that + + + align:start position:0% +call that +something e to the D where D is just + + align:start position:0% +something e to the D where D is just + + + align:start position:0% +something e to the D where D is just +some number integer and + + align:start position:0% +some number integer and + + + align:start position:0% +some number integer and +then some function of logarithms of p p + + align:start position:0% +then some function of logarithms of p p + + + align:start position:0% +then some function of logarithms of p p +over mu or M pi over mu so e here is my + + align:start position:0% +over mu or M pi over mu so e here is my + + + align:start position:0% +over mu or M pi over mu so e here is my +e could be M Pi or p and for the purpose + + align:start position:0% +e could be M Pi or p and for the purpose + + + align:start position:0% +e could be M Pi or p and for the purpose +of power counting I'm not distinguishing + + align:start position:0% +of power counting I'm not distinguishing + + + align:start position:0% +of power counting I'm not distinguishing +so let's just call it e just to have a a + + align:start position:0% +so let's just call it e just to have a a + + + align:start position:0% +so let's just call it e just to have a a +notation that could be either M Pi or + + align:start position:0% +notation that could be either M Pi or + + + align:start position:0% +notation that could be either M Pi or +p and then there's one more thing we can + + align:start position:0% +p and then there's one more thing we can + + + align:start position:0% +p and then there's one more thing we can +do which is we can look at the left hand + + align:start position:0% +do which is we can look at the left hand + + + align:start position:0% +do which is we can look at the left hand +side and we can say just by dimensional + + align:start position:0% +side and we can say just by dimensional + + + align:start position:0% +side and we can say just by dimensional +analysis what should the Matrix element + + align:start position:0% +analysis what should the Matrix element + + + align:start position:0% +analysis what should the Matrix element +what should be its Dimension and + + align:start position:0% +what should be its Dimension and + + + align:start position:0% +what should be its Dimension and +depending on how many bons you have + + align:start position:0% +depending on how many bons you have + + + align:start position:0% +depending on how many bons you have +sticking out your Matrix element should + + align:start position:0% +sticking out your Matrix element should + + + align:start position:0% +sticking out your Matrix element should +have a certain Dimension which you could + + align:start position:0% +have a certain Dimension which you could + + + align:start position:0% +have a certain Dimension which you could +figure + + align:start position:0% +figure + + + align:start position:0% +figure +out and that + + align:start position:0% + + + + align:start position:0% + +Dimension is Just 4 minus NE + + align:start position:0% + + + + align:start position:0% + +twoo function would scale like p^ + + align:start position:0% +twoo function would scale like p^ + + + align:start position:0% +twoo function would scale like p^ +s Etc so now I have different things + + align:start position:0% +s Etc so now I have different things + + + align:start position:0% +s Etc so now I have different things +that are giving Mass Dimensions the + + align:start position:0% +that are giving Mass Dimensions the + + + align:start position:0% +that are giving Mass Dimensions the +Lambda kis and the e but because I know + + align:start position:0% +Lambda kis and the e but because I know + + + align:start position:0% +Lambda kis and the e but because I know +what the answer has to be 4 minus NE I + + align:start position:0% +what the answer has to be 4 minus NE I + + + align:start position:0% +what the answer has to be 4 minus NE I +can solve for d + + align:start position:0% + + + + align:start position:0% + +that's what I + + align:start position:0% + + + + align:start position:0% + +got okay so the answer for D in order to + + align:start position:0% +got okay so the answer for D in order to + + + align:start position:0% +got okay so the answer for D in order to +get the dimensions right we have to + + align:start position:0% +get the dimensions right we have to + + + align:start position:0% +get the dimensions right we have to +compensate for the number of Lambda kis + + align:start position:0% +compensate for the number of Lambda kis + + + align:start position:0% +compensate for the number of Lambda kis +by factors of M pi and P and when we do + + align:start position:0% +by factors of M pi and P and when we do + + + align:start position:0% +by factors of M pi and P and when we do +that then we need this many of them in + + align:start position:0% +that then we need this many of them in + + + align:start position:0% +that then we need this many of them in +order to get Dimensions + + align:start position:0% +order to get Dimensions + + + align:start position:0% +order to get Dimensions +right so one thing you see from this + + align:start position:0% +right so one thing you see from this + + + align:start position:0% +right so one thing you see from this +formula is that D is greater than or + + align:start position:0% +formula is that D is greater than or + + + align:start position:0% +formula is that D is greater than or +equal to two that's because these things + + align:start position:0% +equal to two that's because these things + + + align:start position:0% +equal to two that's because these things +are positive the Lan starts with nals 2 + + align:start position:0% +are positive the Lan starts with nals 2 + + + align:start position:0% +are positive the Lan starts with nals 2 +and then goes higher + + align:start position:0% + + + + align:start position:0% + +and when I add either of these terms I + + align:start position:0% +and when I add either of these terms I + + + align:start position:0% +and when I add either of these terms I +cause + + align:start position:0% +cause + + + align:start position:0% +cause +suppression or I stay the + + align:start position:0% + + + + align:start position:0% + +same so this could be zero this could be + + align:start position:0% +same so this could be zero this could be + + + align:start position:0% +same so this could be zero this could be +zero or it could be bigger but it can't + + align:start position:0% +zero or it could be bigger but it can't + + + align:start position:0% +zero or it could be bigger but it can't +be smaller + + align:start position:0% + + + + align:start position:0% + +so you always get more e which are in + + align:start position:0% +so you always get more e which are in + + + align:start position:0% +so you always get more e which are in +pies or Ps by adding vertices or adding + + align:start position:0% +pies or Ps by adding vertices or adding + + + align:start position:0% +pies or Ps by adding vertices or adding +Loops so when you looked at the Loop + + align:start position:0% +Loops so when you looked at the Loop + + + align:start position:0% +Loops so when you looked at the Loop +graphs that were built out of the + + align:start position:0% +graphs that were built out of the + + + align:start position:0% +graphs that were built out of the +leading order lran those terms had this + + align:start position:0% +leading order lran those terms had this + + + align:start position:0% +leading order lran those terms had this +be zero because n was two but then you + + align:start position:0% +be zero because n was two but then you + + + align:start position:0% +be zero because n was two but then you +got suppression because we built Loop + + align:start position:0% +got suppression because we built Loop + + + align:start position:0% +got suppression because we built Loop +graphs so we got suppression from this + + align:start position:0% +graphs so we got suppression from this + + + align:start position:0% +graphs so we got suppression from this +term and when we looked at the higher + + align:start position:0% +term and when we looked at the higher + + + align:start position:0% +term and when we looked at the higher +Dimension operators there was no Loop so + + align:start position:0% +Dimension operators there was no Loop so + + + align:start position:0% +Dimension operators there was no Loop so +we didn't have this term but then we had + + align:start position:0% +we didn't have this term but then we had + + + align:start position:0% +we didn't have this term but then we had +a contribution from this guy + + align:start position:0% +a contribution from this guy + + + align:start position:0% +a contribution from this guy +but those were're trading + + align:start position:0% + + + + align:start position:0% + +off so having this is you know + + align:start position:0% +off so having this is you know + + + align:start position:0% +off so having this is you know +effectively def part of what we need in + + align:start position:0% +effectively def part of what we need in + + + align:start position:0% +effectively def part of what we need in +order to make sure the theory is well + + align:start position:0% +order to make sure the theory is well + + + align:start position:0% +order to make sure the theory is well +defined because it tells us how to + + align:start position:0% +defined because it tells us how to + + + align:start position:0% +defined because it tells us how to +organize the theory and + + align:start position:0% +organize the theory and + + + align:start position:0% +organize the theory and +what parts of the theory we need to + + align:start position:0% +what parts of the theory we need to + + + align:start position:0% +what parts of the theory we need to +worry about if we want a certain + + align:start position:0% +worry about if we want a certain + + + align:start position:0% +worry about if we want a certain +accuracy and what parts we can + + align:start position:0% +accuracy and what parts we can + + + align:start position:0% +accuracy and what parts we can +ignore we need to know that we don't + + align:start position:0% +ignore we need to know that we don't + + + align:start position:0% +ignore we need to know that we don't +need to think about two Loop diagrams + + align:start position:0% +need to think about two Loop diagrams + + + align:start position:0% +need to think about two Loop diagrams +when this tells us that we don't + + align:start position:0% +when this tells us that we don't + + + align:start position:0% +when this tells us that we don't +yeah I didn't + + align:start position:0% +yeah I didn't + + + align:start position:0% +yeah I didn't +understand yeah let me say it again so + + align:start position:0% +understand yeah let me say it again so + + + align:start position:0% +understand yeah let me say it again so +we figured out the Lambda kis by this + + align:start position:0% +we figured out the Lambda kis by this + + + align:start position:0% +we figured out the Lambda kis by this +stuff up here then I said let there be + + align:start position:0% +stuff up here then I said let there be + + + align:start position:0% +stuff up here then I said let there be +an arbitrary e to the D some some + + align:start position:0% +an arbitrary e to the D some some + + + align:start position:0% +an arbitrary e to the D some some +parameter which we haven't figured out + + align:start position:0% +parameter which we haven't figured out + + + align:start position:0% +parameter which we haven't figured out +anything yet but I know just by diens I + + align:start position:0% +anything yet but I know just by diens I + + + align:start position:0% +anything yet but I know just by diens I +know by just what possibly this could + + align:start position:0% +know by just what possibly this could + + + align:start position:0% +know by just what possibly this could +depend on that it could also depend on + + align:start position:0% +depend on that it could also depend on + + + align:start position:0% +depend on that it could also depend on +empis or PS so let me put some + + align:start position:0% +empis or PS so let me put some + + + align:start position:0% +empis or PS so let me put some +polinomial power in and then some + + align:start position:0% +polinomial power in and then some + + + align:start position:0% +polinomial power in and then some +function that could be non-p polinomial + + align:start position:0% +function that could be non-p polinomial + + + align:start position:0% +function that could be non-p polinomial +where would that can you give an example + + align:start position:0% +where would that can you give an example + + + align:start position:0% +where would that can you give an example +of like a calculation where I would see + + align:start position:0% +of like a calculation where I would see + + + align:start position:0% +of like a calculation where I would see +exactly what that is yeah so if you did + + align:start position:0% +exactly what that is yeah so if you did + + + align:start position:0% +exactly what that is yeah so if you did +this Loop calculation we did a minute + + align:start position:0% +this Loop calculation we did a minute + + + align:start position:0% +this Loop calculation we did a minute +ago we got a p to the 4th and then D + + align:start position:0% +ago we got a p to the 4th and then D + + + align:start position:0% +ago we got a p to the 4th and then D +would be four and those P's came from + + align:start position:0% +would be four and those P's came from + + + align:start position:0% +would be four and those P's came from +where oh they came from like the you + + align:start position:0% +where oh they came from like the you + + + align:start position:0% +where oh they came from like the you +know the the momentum going into so if + + align:start position:0% +know the the momentum going into so if + + + align:start position:0% +know the the momentum going into so if +you looked at this + + align:start position:0% +you looked at this + + + align:start position:0% +you looked at this +diagram yeah there's P coming in here + + align:start position:0% +diagram yeah there's P coming in here + + + align:start position:0% +diagram yeah there's P coming in here +and then it goes into the + + align:start position:0% +and then it goes into the + + + align:start position:0% +and then it goes into the +loop right and this is derivatively + + align:start position:0% +loop right and this is derivatively + + + align:start position:0% +loop right and this is derivatively +coupled so you get P's in the + + align:start position:0% +coupled so you get P's in the + + + align:start position:0% +coupled so you get P's in the +numerator Tak care of with right because + + align:start position:0% +numerator Tak care of with right because + + + align:start position:0% +numerator Tak care of with right because +NV is just counting Lambda kis which are + + align:start position:0% +NV is just counting Lambda kis which are + + + align:start position:0% +NV is just counting Lambda kis which are +constants not the PS it's just counting + + align:start position:0% +constants not the PS it's just counting + + + align:start position:0% +constants not the PS it's just counting +the the constants the + + align:start position:0% +the the constants the + + + align:start position:0% +the the constants the +fs + + align:start position:0% +fs + + + align:start position:0% +fs +yeah yeah and then you equate it to this + + align:start position:0% +yeah yeah and then you equate it to this + + + align:start position:0% +yeah yeah and then you equate it to this +and then you get the + + align:start position:0% +and then you get the + + + align:start position:0% +and then you get the +D yeah so you could have tried to set + + align:start position:0% +D yeah so you could have tried to set + + + align:start position:0% +D yeah so you could have tried to set +things up by thinking about counting P's + + align:start position:0% +things up by thinking about counting P's + + + align:start position:0% +things up by thinking about counting P's +instead of counting lambdas but it's a + + align:start position:0% +instead of counting lambdas but it's a + + + align:start position:0% +instead of counting lambdas but it's a +yeah + + align:start position:0% + + + + align:start position:0% + +anyway all right so what this what + + align:start position:0% +anyway all right so what this what + + + align:start position:0% +anyway all right so what this what +people often refer to this is is they + + align:start position:0% +people often refer to this is is they + + + align:start position:0% +people often refer to this is is they +say it's p + + align:start position:0% + + + + align:start position:0% + +counting because you're counting + + align:start position:0% +counting because you're counting + + + align:start position:0% +counting because you're counting +momenta and that includes P or M Pi but + + align:start position:0% +momenta and that includes P or M Pi but + + + align:start position:0% +momenta and that includes P or M Pi but +sometimes people call it P + + align:start position:0% +sometimes people call it P + + + align:start position:0% +sometimes people call it P +counting and just to do some examples + + align:start position:0% +counting and just to do some examples + + + align:start position:0% +counting and just to do some examples +when we had the lowest order + + align:start position:0% +when we had the lowest order + + + align:start position:0% +when we had the lowest order +lran we this guy comes out as two powers + + align:start position:0% +lran we this guy comes out as two powers + + + align:start position:0% +lran we this guy comes out as two powers +of of P because there's two + + align:start position:0% + + + + align:start position:0% + +derivatives and that in our + + align:start position:0% +derivatives and that in our + + + align:start position:0% +derivatives and that in our +formula is just the fact that D is two + + align:start position:0% +formula is just the fact that D is two + + + align:start position:0% +formula is just the fact that D is two +for + + align:start position:0% +for + + + align:start position:0% +for +that when we thought about this + + align:start position:0% +that when we thought about this + + + align:start position:0% +that when we thought about this +loop with leading or Lans which are + + align:start position:0% +loop with leading or Lans which are + + + align:start position:0% +loop with leading or Lans which are +scanning like p^ + + align:start position:0% + + + + align:start position:0% + +squ we ended up having D equal 4 and the + + align:start position:0% +squ we ended up having D equal 4 and the + + + align:start position:0% +squ we ended up having D equal 4 and the +way that that comes out of the formula + + align:start position:0% +way that that comes out of the formula + + + align:start position:0% +way that that comes out of the formula +is because of this Loop term which is + + align:start position:0% +is because of this Loop term which is + + + align:start position:0% +is because of this Loop term which is +one and then there's two one 2 plus 2 is + + align:start position:0% + + + + align:start position:0% + +four and this guy is four because of the + + align:start position:0% +four and this guy is four because of the + + + align:start position:0% +four and this guy is four because of the +explicit + + align:start position:0% + + + + align:start position:0% + +suppression okay so the theory is + + align:start position:0% +suppression okay so the theory is + + + align:start position:0% +suppression okay so the theory is +organized as an expansion in this p + + align:start position:0% + + + + align:start position:0% + +all right so I want to come back to su3 + + align:start position:0% +all right so I want to come back to su3 + + + align:start position:0% +all right so I want to come back to su3 +partly because the problem that I gave + + align:start position:0% +partly because the problem that I gave + + + align:start position:0% +partly because the problem that I gave +you is in + + align:start position:0% +you is in + + + align:start position:0% +you is in +su3 so we'll do + + align:start position:0% +su3 so we'll do + + + align:start position:0% +su3 so we'll do +some discussion of the su3 + + align:start position:0% + + + + align:start position:0% + +case now I'll go into a few things in a + + align:start position:0% +case now I'll go into a few things in a + + + align:start position:0% +case now I'll go into a few things in a +little more detail than we did for su2 + + align:start position:0% +little more detail than we did for su2 + + + align:start position:0% +little more detail than we did for su2 +where we are focusing on more formal + + align:start position:0% +where we are focusing on more formal + + + align:start position:0% +where we are focusing on more formal +things so su3 would have Gman matrices + + align:start position:0% +things so su3 would have Gman matrices + + + align:start position:0% +things so su3 would have Gman matrices +instead of the poly + + align:start position:0% +instead of the poly + + + align:start position:0% +instead of the poly +matrices there's two bases that you can + + align:start position:0% +matrices there's two bases that you can + + + align:start position:0% +matrices there's two bases that you can +use you can either use this basis which + + align:start position:0% +use you can either use this basis which + + + align:start position:0% +use you can either use this basis which +is like what numerated 1 to8 or you + + align:start position:0% +is like what numerated 1 to8 or you + + + align:start position:0% +is like what numerated 1 to8 or you +could use the charge basis and if you + + align:start position:0% +could use the charge basis and if you + + + align:start position:0% +could use the charge basis and if you +use the charge basis then often you + + align:start position:0% +use the charge basis then often you + + + align:start position:0% +use the charge basis then often you +write it out as a matrix like this + + align:start position:0% + + + + align:start position:0% + +on your problem set you're free to pick + + align:start position:0% +on your problem set you're free to pick + + + align:start position:0% +on your problem set you're free to pick +which basis you want to + + align:start position:0% + + + + align:start position:0% + +use it may be that one or the other is + + align:start position:0% +use it may be that one or the other is + + + align:start position:0% +use it may be that one or the other is +easier but I can't even tell you which + + align:start position:0% +easier but I can't even tell you which + + + align:start position:0% +easier but I can't even tell you which +one is easier since I don't + + align:start position:0% + + + + align:start position:0% + +remember so sometimes one or the other + + align:start position:0% +remember so sometimes one or the other + + + align:start position:0% +remember so sometimes one or the other +is easier to use and you have a freedom + + align:start position:0% +is easier to use and you have a freedom + + + align:start position:0% +is easier to use and you have a freedom +of what basis to + + align:start position:0% + + + + align:start position:0% + +pick if you expand in this case + + align:start position:0% +pick if you expand in this case + + + align:start position:0% +pick if you expand in this case +the trace of Sigma mq diag + + align:start position:0% +the trace of Sigma mq diag + + + align:start position:0% +the trace of Sigma mq diag +plus mq Sigma diager which is that term + + align:start position:0% +plus mq Sigma diager which is that term + + + align:start position:0% +plus mq Sigma diager which is that term +that had a v + + align:start position:0% +that had a v + + + align:start position:0% +that had a v +zero then that gives you Mass to the + + align:start position:0% +zero then that gives you Mass to the + + + align:start position:0% +zero then that gives you Mass to the +mesons as it did for the + + align:start position:0% + + + + align:start position:0% + +pons because the Symmetry group is + + align:start position:0% +pons because the Symmetry group is + + + align:start position:0% +pons because the Symmetry group is +bigger you get more + + align:start position:0% +bigger you get more + + + align:start position:0% +bigger you get more +predictions here you get predictions for + + align:start position:0% +predictions here you get predictions for + + + align:start position:0% +predictions here you get predictions for +the Kon + + align:start position:0% +the Kon + + + align:start position:0% +the Kon +masses and you get things like the fact + + align:start position:0% +masses and you get things like the fact + + + align:start position:0% +masses and you get things like the fact +that the neutral + + align:start position:0% +that the neutral + + + align:start position:0% +that the neutral +chons + + align:start position:0% + + + + align:start position:0% + +have mass is over MD plus + + align:start position:0% +have mass is over MD plus + + + align:start position:0% +have mass is over MD plus +Ms and you get things + + align:start position:0% +Ms and you get things + + + align:start position:0% +Ms and you get things +like Ada Pi 0 mixing where there's a + + align:start position:0% +like Ada Pi 0 mixing where there's a + + + align:start position:0% +like Ada Pi 0 mixing where there's a +mixing Matrix so if you look at the + + align:start position:0% +mixing Matrix so if you look at the + + + align:start position:0% +mixing Matrix so if you look at the +masses of ADA and Pi 0 they're actually + + align:start position:0% +masses of ADA and Pi 0 they're actually + + + align:start position:0% +masses of ADA and Pi 0 they're actually +non-diagonal so for the Ada in the pi Z + + align:start position:0% +non-diagonal so for the Ada in the pi Z + + + align:start position:0% +non-diagonal so for the Ada in the pi Z +system you actually get a + + align:start position:0% +system you actually get a + + + align:start position:0% +system you actually get a +matrix so m^2 is a matrix + + align:start position:0% +matrix so m^2 is a matrix + + + align:start position:0% +matrix so m^2 is a matrix +and the terms so for example for the pi + + align:start position:0% +and the terms so for example for the pi + + + align:start position:0% +and the terms so for example for the pi +Z it was just m up plus + + align:start position:0% +Z it was just m up plus + + + align:start position:0% +Z it was just m up plus +MD and for but then once you're in su3 + + align:start position:0% +MD and for but then once you're in su3 + + + align:start position:0% +MD and for but then once you're in su3 +there's actually a mixing term and + + align:start position:0% +there's actually a mixing term and + + + align:start position:0% +there's actually a mixing term and +there's like an M up minus M down term + + align:start position:0% +there's like an M up minus M down term + + + align:start position:0% +there's like an M up minus M down term +here that is mixing between and then + + align:start position:0% +here that is mixing between and then + + + align:start position:0% +here that is mixing between and then +same thing over here so the Adas and the + + align:start position:0% +same thing over here so the Adas and the + + + align:start position:0% +same thing over here so the Adas and the +pi Z actually are mixing and then + + align:start position:0% +pi Z actually are mixing and then + + + align:start position:0% +pi Z actually are mixing and then +there's something in this + + align:start position:0% +there's something in this + + + align:start position:0% +there's something in this +entry and the mixing is is been + + align:start position:0% +entry and the mixing is is been + + + align:start position:0% +entry and the mixing is is been +violating in the sense that it's m up + + align:start position:0% +violating in the sense that it's m up + + + align:start position:0% +violating in the sense that it's m up +minus M down so it's a small + + align:start position:0% +minus M down so it's a small + + + align:start position:0% +minus M down so it's a small +effect but this is something that you + + align:start position:0% +effect but this is something that you + + + align:start position:0% +effect but this is something that you +can predict from the car in something + + align:start position:0% +can predict from the car in something + + + align:start position:0% +can predict from the car in something +about because it describes isospin + + align:start position:0% +about because it describes isospin + + + align:start position:0% +about because it describes isospin +violating effects from the cork + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +masses so there's the reason that I + + align:start position:0% +masses so there's the reason that I + + + align:start position:0% +masses so there's the reason that I +mentioned that is because often when you + + align:start position:0% +mentioned that is because often when you + + + align:start position:0% +mentioned that is because often when you +do calculations keeping track of M MDS + + align:start position:0% +do calculations keeping track of M MDS + + + align:start position:0% +do calculations keeping track of M MDS +and ms's all as separate independent + + align:start position:0% +and ms's all as separate independent + + + align:start position:0% +and ms's all as separate independent +parameters is a little much + + align:start position:0% +parameters is a little much + + + align:start position:0% +parameters is a little much +and so you want to make an approximation + + align:start position:0% +and so you want to make an approximation + + + align:start position:0% +and so you want to make an approximation +and so if you make an + + align:start position:0% +and so if you make an + + + align:start position:0% +and so if you make an +approximation that ignores isospin + + align:start position:0% + + + + align:start position:0% + +violation + + align:start position:0% +violation + + + align:start position:0% +violation +so we often ignore isospin + + align:start position:0% +so we often ignore isospin + + + align:start position:0% +so we often ignore isospin +violation isospin violation is very + + align:start position:0% +violation isospin violation is very + + + align:start position:0% +violation isospin violation is very +small and if you remember for the su3 + + align:start position:0% +small and if you remember for the su3 + + + align:start position:0% +small and if you remember for the su3 +case you're expanding an MS over Lambda + + align:start position:0% +case you're expanding an MS over Lambda + + + align:start position:0% +case you're expanding an MS over Lambda +qcd or MK over Lambda Kai so it's not a + + align:start position:0% +qcd or MK over Lambda Kai so it's not a + + + align:start position:0% +qcd or MK over Lambda Kai so it's not a +great expansion you something like a + + align:start position:0% +great expansion you something like a + + + align:start position:0% +great expansion you something like a +third uh so ignoring isospin is + + align:start position:0% +third uh so ignoring isospin is + + + align:start position:0% +third uh so ignoring isospin is +perfectly valid if you're expanding in + + align:start position:0% +perfectly valid if you're expanding in + + + align:start position:0% +perfectly valid if you're expanding in +third so basically because there's a + + align:start position:0% +third so basically because there's a + + + align:start position:0% +third so basically because there's a +hierarchy between the strange Quirk mass + + align:start position:0% +hierarchy between the strange Quirk mass + + + align:start position:0% +hierarchy between the strange Quirk mass +and the down and the up uh you want to + + align:start position:0% +and the down and the up uh you want to + + + align:start position:0% +and the down and the up uh you want to +focus on places where you get the + + align:start position:0% +focus on places where you get the + + + align:start position:0% +focus on places where you get the +largest Corrections and one way of + + align:start position:0% +largest Corrections and one way of + + + align:start position:0% +largest Corrections and one way of +making an approximation that allows you + + align:start position:0% +making an approximation that allows you + + + align:start position:0% +making an approximation that allows you +to do that is to ignore Isis Spin and + + align:start position:0% +to do that is to ignore Isis Spin and + + + align:start position:0% +to do that is to ignore Isis Spin and +take mu equal to + + align:start position:0% +take mu equal to + + + align:start position:0% +take mu equal to +MD + + align:start position:0% +MD + + + align:start position:0% +MD +so if we take mu and MD to be some M hat + + align:start position:0% +so if we take mu and MD to be some M hat + + + align:start position:0% +so if we take mu and MD to be some M hat +which you can if you want a exact + + align:start position:0% +which you can if you want a exact + + + align:start position:0% +which you can if you want a exact +definition you could say it's + + align:start position:0% +definition you could say it's + + + align:start position:0% +definition you could say it's +the average and you drw the + + align:start position:0% + + + + align:start position:0% + +difference and then you can think of the + + align:start position:0% +difference and then you can think of the + + + align:start position:0% +difference and then you can think of the +strange Quirk mass as being somewhat + + align:start position:0% +strange Quirk mass as being somewhat + + + align:start position:0% +strange Quirk mass as being somewhat +bigger than M + + align:start position:0% + + + + align:start position:0% + +hat that's an approximation that you can + + align:start position:0% +hat that's an approximation that you can + + + align:start position:0% +hat that's an approximation that you can +use on your problem set for + + align:start position:0% + + + + align:start position:0% + +example so let me write out here what + + align:start position:0% +example so let me write out here what + + + align:start position:0% +example so let me write out here what +all the terms in the kyi is and I'll do + + align:start position:0% +all the terms in the kyi is and I'll do + + + align:start position:0% +all the terms in the kyi is and I'll do +it for a case where we where we include + + align:start position:0% +it for a case where we where we include + + + align:start position:0% +it for a case where we where we include +in our kyian one + + align:start position:0% +in our kyian one + + + align:start position:0% +in our kyian one +other type of + + align:start position:0% +other type of + + + align:start position:0% +other type of +coupling which is this left-handed + + align:start position:0% +coupling which is this left-handed + + + align:start position:0% +coupling which is this left-handed +current that we talked about last + + align:start position:0% +current that we talked about last + + + align:start position:0% +current that we talked about last +time so we talked about a spion analysis + + align:start position:0% +time so we talked about a spion analysis + + + align:start position:0% +time so we talked about a spion analysis +for the kai term and I said you could do + + align:start position:0% +for the kai term and I said you could do + + + align:start position:0% +for the kai term and I said you could do +something similar to couple in a + + align:start position:0% +something similar to couple in a + + + align:start position:0% +something similar to couple in a +left-handed current and we had this + + align:start position:0% +left-handed current and we had this + + + align:start position:0% +left-handed current and we had this +where D mu Sigma was partial mu + + align:start position:0% +where D mu Sigma was partial mu + + + align:start position:0% +where D mu Sigma was partial mu +Sigma times the left handed current + + align:start position:0% +Sigma times the left handed current + + + align:start position:0% +Sigma times the left handed current +Sigma so we thought of it putting it + + align:start position:0% +Sigma so we thought of it putting it + + + align:start position:0% +Sigma so we thought of it putting it +together into a covariant derivative and + + align:start position:0% +together into a covariant derivative and + + + align:start position:0% +together into a covariant derivative and +if I do that it modifies the leading + + align:start position:0% +if I do that it modifies the leading + + + align:start position:0% +if I do that it modifies the leading +order LR and just makes these partials + + align:start position:0% +order LR and just makes these partials + + + align:start position:0% +order LR and just makes these partials +into covariant + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +derivatives power + + align:start position:0% +derivatives power + + + align:start position:0% +derivatives power +counting for power counting purposes you + + align:start position:0% +counting for power counting purposes you + + + align:start position:0% +counting for power counting purposes you +count Sigma of order one you count D mu + + align:start position:0% +count Sigma of order one you count D mu + + + align:start position:0% +count Sigma of order one you count D mu +Sigma as order p + + align:start position:0% +Sigma as order p + + + align:start position:0% +Sigma as order p +which means you count LM the source as + + align:start position:0% +which means you count LM the source as + + + align:start position:0% +which means you count LM the source as +order P this is a left-handed + + align:start position:0% +order P this is a left-handed + + + align:start position:0% +order P this is a left-handed +source and you count K's and mqs as of + + align:start position:0% +source and you count K's and mqs as of + + + align:start position:0% +source and you count K's and mqs as of +order p^ + + align:start position:0% +order p^ + + + align:start position:0% +order p^ +s that's just repeating what we've + + align:start position:0% +s that's just repeating what we've + + + align:start position:0% +s that's just repeating what we've +already + + align:start position:0% +already + + + align:start position:0% +already +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +said and these higher order terms which + + align:start position:0% +said and these higher order terms which + + + align:start position:0% +said and these higher order terms which +were L's we can then + + align:start position:0% + + + + align:start position:0% + +enumerate and I now just use + + align:start position:0% +enumerate and I now just use + + + align:start position:0% +enumerate and I now just use +D's covariant D's when I write them + + align:start position:0% +D's covariant D's when I write them + + + align:start position:0% +D's covariant D's when I write them +down I'm now in + + align:start position:0% +down I'm now in + + + align:start position:0% +down I'm now in +su3 and it turns out that one of the + + align:start position:0% +su3 and it turns out that one of the + + + align:start position:0% +su3 and it turns out that one of the +relations that we used in su2 doesn't + + align:start position:0% +relations that we used in su2 doesn't + + + align:start position:0% +relations that we used in su2 doesn't +carry over to su3 so if I just think of + + align:start position:0% +carry over to su3 so if I just think of + + + align:start position:0% +carry over to su3 so if I just think of +four guys with four coant + + align:start position:0% +four guys with four coant + + + align:start position:0% +four guys with four coant +derivatives it turns out that + + align:start position:0% +derivatives it turns out that + + + align:start position:0% +derivatives it turns out that +there's one more operator + + align:start position:0% + + + + align:start position:0% + +there so there's those two which we + + align:start position:0% +there so there's those two which we + + + align:start position:0% +there so there's those two which we +talked about L1 an L L2 and then there's + + align:start position:0% +talked about L1 an L L2 and then there's + + + align:start position:0% +talked about L1 an L L2 and then there's +also an + + align:start position:0% +also an + + + align:start position:0% +also an +L3 so we can't get rid of this + + align:start position:0% + + + + align:start position:0% + +guy I'm always writing sigas next to + + align:start position:0% +guy I'm always writing sigas next to + + + align:start position:0% +guy I'm always writing sigas next to +Sigma daggers because the chyal + + align:start position:0% +Sigma daggers because the chyal + + + align:start position:0% +Sigma daggers because the chyal +transformation I'm also imposing parody + + align:start position:0% +transformation I'm also imposing parody + + + align:start position:0% +transformation I'm also imposing parody +although I'm not going to spend much + + align:start position:0% +although I'm not going to spend much + + + align:start position:0% +although I'm not going to spend much +time talking about + + align:start position:0% + + + + align:start position:0% + +that and really I want to enumerate also + + align:start position:0% +that and really I want to enumerate also + + + align:start position:0% +that and really I want to enumerate also +for you some of the terms that involve + + align:start position:0% +for you some of the terms that involve + + + align:start position:0% +for you some of the terms that involve +the the core Mass Kai + + align:start position:0% +the the core Mass Kai + + + align:start position:0% +the the core Mass Kai +guy so you could have a guy that's a + + align:start position:0% +guy so you could have a guy that's a + + + align:start position:0% +guy so you could have a guy that's a +cross term this would take care of the + + align:start position:0% + + + + align:start position:0% + +normalization of things like p^2 and pi^ + + align:start position:0% +normalization of things like p^2 and pi^ + + + align:start position:0% +normalization of things like p^2 and pi^ +S * 1 over + + align:start position:0% + + + + align:start position:0% + +Epsilon that's + + align:start position:0% +Epsilon that's + + + align:start position:0% +Epsilon that's +L4 L5 + + align:start position:0% + + + + align:start position:0% + +we could also have the cork mass type + + align:start position:0% +we could also have the cork mass type + + + align:start position:0% +we could also have the cork mass type +term just + + align:start position:0% + + + + align:start position:0% + +squared so take the trace and square it + + align:start position:0% +squared so take the trace and square it + + + align:start position:0% +squared so take the trace and square it +that's + + align:start position:0% +that's + + + align:start position:0% +that's +L6 it turns out that we could also build + + align:start position:0% +L6 it turns out that we could also build + + + align:start position:0% +L6 it turns out that we could also build +something with the right par by just + + align:start position:0% +something with the right par by just + + + align:start position:0% +something with the right par by just +having the difference instead of the sum + + align:start position:0% +having the difference instead of the sum + + + align:start position:0% +having the difference instead of the sum +and that's a different + + align:start position:0% + + + + align:start position:0% + +operator so that's + + align:start position:0% + + + + align:start position:0% + +L7 we're going to go up to + + align:start position:0% + + + + align:start position:0% + +nine don't don't be + + align:start position:0% +nine don't don't be + + + align:start position:0% +nine don't don't be +afraid you could have something with two + + align:start position:0% +afraid you could have something with two + + + align:start position:0% +afraid you could have something with two +Sigma diagoras and two kis which is + + align:start position:0% +Sigma diagoras and two kis which is + + + align:start position:0% +Sigma diagoras and two kis which is +another way of building a kyol + + align:start position:0% +another way of building a kyol + + + align:start position:0% +another way of building a kyol +invariant and then for parity you need + + align:start position:0% +invariant and then for parity you need + + + align:start position:0% +invariant and then for parity you need +the other other + + align:start position:0% +the other other + + + align:start position:0% +the other other +way and then + + align:start position:0% +way and then + + + align:start position:0% +way and then +finally something called + + align:start position:0% +finally something called + + + align:start position:0% +finally something called +L9 which involves a trace that + + align:start position:0% +L9 which involves a trace that + + + align:start position:0% +L9 which involves a trace that +involves L mu new where L muu is built + + align:start position:0% +involves L mu new where L muu is built + + + align:start position:0% +involves L mu new where L muu is built +out of this external + + align:start position:0% +out of this external + + + align:start position:0% +out of this external +current so we can take two of our + + align:start position:0% +current so we can take two of our + + + align:start position:0% +current so we can take two of our +covariant derivatives and take a + + align:start position:0% + + + + align:start position:0% + +commutator that's giving the final + + align:start position:0% +commutator that's giving the final + + + align:start position:0% +commutator that's giving the final +operator + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +so there's a complete basis for + + align:start position:0% +so there's a complete basis for + + + align:start position:0% +so there's a complete basis for +su3 for a left-handed current in a + + align:start position:0% + + + + align:start position:0% + +Kai yeah I'll write it down and + + align:start position:0% + + + + align:start position:0% + +so if L mu is something that has su3 + + align:start position:0% +so if L mu is something that has su3 + + + align:start position:0% +so if L mu is something that has su3 +indices has an su3 Matrix hiding inside + + align:start position:0% +indices has an su3 Matrix hiding inside + + + align:start position:0% +indices has an su3 Matrix hiding inside +it then there's a commutator term as + + align:start position:0% +it then there's a commutator term as + + + align:start position:0% +it then there's a commutator term as +well and then it's just this combination + + align:start position:0% +well and then it's just this combination + + + align:start position:0% +well and then it's just this combination +I also Ed the equation of + + align:start position:0% +I also Ed the equation of + + + align:start position:0% +I also Ed the equation of +motion and I didn't talk about it but I + + align:start position:0% +motion and I didn't talk about it but I + + + align:start position:0% +motion and I didn't talk about it but I +used the equation of motion and I used + + align:start position:0% +used the equation of motion and I used + + + align:start position:0% +used the equation of motion and I used +su3 relations much as I talked about for + + align:start position:0% +su3 relations much as I talked about for + + + align:start position:0% +su3 relations much as I talked about for +su2 there's some su3 relations that + + align:start position:0% +su2 there's some su3 relations that + + + align:start position:0% +su2 there's some su3 relations that +survive and I got rid of some operators + + align:start position:0% +survive and I got rid of some operators + + + align:start position:0% +survive and I got rid of some operators +doing + + align:start position:0% + + + + align:start position:0% + +that now you could say well I have this + + align:start position:0% +that now you could say well I have this + + + align:start position:0% +that now you could say well I have this +su3 and su2 so why don't I try to relate + + align:start position:0% +su3 and su2 so why don't I try to relate + + + align:start position:0% +su3 and su2 so why don't I try to relate +them one of them has a Kon the other one + + align:start position:0% +them one of them has a Kon the other one + + + align:start position:0% +them one of them has a Kon the other one +doesn't the one without the Kon thinks + + align:start position:0% +doesn't the one without the Kon thinks + + + align:start position:0% +doesn't the one without the Kon thinks +about the Chon as a heavy particle the + + align:start position:0% +about the Chon as a heavy particle the + + + align:start position:0% +about the Chon as a heavy particle the +one with the Chon thinks about the Chon + + align:start position:0% +one with the Chon thinks about the Chon + + + align:start position:0% +one with the Chon thinks about the Chon +as a light particle those are two + + align:start position:0% +as a light particle those are two + + + align:start position:0% +as a light particle those are two +theories I could try to make them match + + align:start position:0% +theories I could try to make them match + + + align:start position:0% +theories I could try to make them match +up with each + + align:start position:0% +up with each + + + align:start position:0% +up with each +other and and that's something that you + + align:start position:0% +other and and that's something that you + + + align:start position:0% +other and and that's something that you +can do + + align:start position:0% + + + + align:start position:0% + +actually + + align:start position:0% + + + + align:start position:0% + +so there's a little bit of a lesson + + align:start position:0% +so there's a little bit of a lesson + + + align:start position:0% +so there's a little bit of a lesson +there so that that's why I want to + + align:start position:0% +there so that that's why I want to + + + align:start position:0% +there so that that's why I want to +mention it + + align:start position:0% + + + + align:start position:0% + +so su2 and su3 seem like they're + + align:start position:0% +so su2 and su3 seem like they're + + + align:start position:0% +so su2 and su3 seem like they're +describing similar physics they both + + align:start position:0% +describing similar physics they both + + + align:start position:0% +describing similar physics they both +could describe P they both have P in + + align:start position:0% +could describe P they both have P in + + + align:start position:0% +could describe P they both have P in +them but the su3 has more it's got the + + align:start position:0% +them but the su3 has more it's got the + + + align:start position:0% +them but the su3 has more it's got the +Kon that means that in the su2 theory + + align:start position:0% +Kon that means that in the su2 theory + + + align:start position:0% +Kon that means that in the su2 theory +the Kon is in the + + align:start position:0% +the Kon is in the + + + align:start position:0% +the Kon is in the +coefficients + + align:start position:0% +coefficients + + + align:start position:0% +coefficients +okay so you if you do a correspondence + + align:start position:0% +okay so you if you do a correspondence + + + align:start position:0% +okay so you if you do a correspondence +you get relations that are like this so + + align:start position:0% +you get relations that are like this so + + + align:start position:0% +you get relations that are like this so +the two here means + + align:start position:0% + + + + align:start position:0% + +su2 and where I don't put any subscript + + align:start position:0% +su2 and where I don't put any subscript + + + align:start position:0% +su2 and where I don't put any subscript +it's + + align:start position:0% + + + + align:start position:0% + +su3 and something + + align:start position:0% +su3 and something + + + align:start position:0% +su3 and something +that this is a + + align:start position:0% + + + + align:start position:0% + +96 and if you really do that what I said + + align:start position:0% +96 and if you really do that what I said + + + align:start position:0% +96 and if you really do that what I said +compare observables you get relations + + align:start position:0% +compare observables you get relations + + + align:start position:0% +compare observables you get relations +like this one where you actually see + + align:start position:0% +like this one where you actually see + + + align:start position:0% +like this one where you actually see +that the Kon is showing up from on this + + align:start position:0% +that the Kon is showing up from on this + + + align:start position:0% +that the Kon is showing up from on this +side where and is being encoded in + + align:start position:0% +side where and is being encoded in + + + align:start position:0% +side where and is being encoded in +coefficient in the su2 + + align:start position:0% +coefficient in the su2 + + + align:start position:0% +coefficient in the su2 +theory so what you think of as the + + align:start position:0% +theory so what you think of as the + + + align:start position:0% +theory so what you think of as the +coefficients in your Kyle Theory depends + + align:start position:0% +coefficients in your Kyle Theory depends + + + align:start position:0% +coefficients in your Kyle Theory depends +on the matter that you've put in + + align:start position:0% +on the matter that you've put in + + + align:start position:0% +on the matter that you've put in +including things like what particles + + align:start position:0% +including things like what particles + + + align:start position:0% +including things like what particles +like the Chon what group you're talking + + align:start position:0% + + + + align:start position:0% + +about this is an explicit example of the + + align:start position:0% + + + + align:start position:0% + +Chon being in the + + align:start position:0% +Chon being in the + + + align:start position:0% +Chon being in the +coefficients if we + + align:start position:0% +coefficients if we + + + align:start position:0% +coefficients if we +use su2 + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so just like in su2 we have to go + + align:start position:0% +so just like in su2 we have to go + + + align:start position:0% +so just like in su2 we have to go +through a + + align:start position:0% +through a + + + align:start position:0% +through a +normalization of the + + align:start position:0% + + + + align:start position:0% + +Lis and you can think of that by writing + + align:start position:0% +Lis and you can think of that by writing + + + align:start position:0% +Lis and you can think of that by writing +a formula like this + + align:start position:0% + + + + align:start position:0% + +one bare Li is equal to sum normalized + + align:start position:0% +one bare Li is equal to sum normalized + + + align:start position:0% +one bare Li is equal to sum normalized +one which I put a bar on top + + align:start position:0% +one which I put a bar on top + + + align:start position:0% +one which I put a bar on top +of and then a counter term and the + + align:start position:0% +of and then a counter term and the + + + align:start position:0% +of and then a counter term and the +counter term will be Su coefficient some + + align:start position:0% +counter term will be Su coefficient some + + + align:start position:0% +counter term will be Su coefficient some +number of four + + align:start position:0% +number of four + + + align:start position:0% +number of four +pies and then some epsilons and just + + align:start position:0% +pies and then some epsilons and just + + + align:start position:0% +pies and then some epsilons and just +like in gauge + + align:start position:0% +like in gauge + + + align:start position:0% +like in gauge +Theory we get rid of the oiler gamma and + + align:start position:0% +Theory we get rid of the oiler gamma and + + + align:start position:0% +Theory we get rid of the oiler gamma and +the four Pi log 4 Pi we have an msar + + align:start position:0% +the four Pi log 4 Pi we have an msar + + + align:start position:0% +the four Pi log 4 Pi we have an msar +type definition and in K pration Theory + + align:start position:0% +type definition and in K pration Theory + + + align:start position:0% +type definition and in K pration Theory +people often take an extra one along + + align:start position:0% +people often take an extra one along + + + align:start position:0% +people often take an extra one along +with the + + align:start position:0% +with the + + + align:start position:0% +with the +ride + + align:start position:0% +ride + + + align:start position:0% +ride +for just because they're allowed + + align:start position:0% +for just because they're allowed + + + align:start position:0% +for just because they're allowed +to because it tends to show up in the + + align:start position:0% +to because it tends to show up in the + + + align:start position:0% +to because it tends to show up in the +kind of Loops that you count encounter + + align:start position:0% +kind of Loops that you count encounter + + + align:start position:0% +kind of Loops that you count encounter +so sometimes that's included sometimes + + align:start position:0% +so sometimes that's included sometimes + + + align:start position:0% +so sometimes that's included sometimes +it's + + align:start position:0% +it's + + + align:start position:0% +it's +not so for + + align:start position:0% +not so for + + + align:start position:0% +not so for +example as an example of a + + align:start position:0% +example as an example of a + + + align:start position:0% +example as an example of a +diagram you could think about this one + + align:start position:0% +diagram you could think about this one + + + align:start position:0% +diagram you could think about this one +and + + align:start position:0% +and + + + align:start position:0% +and +that does cause mass renormalization for + + align:start position:0% +that does cause mass renormalization for + + + align:start position:0% +that does cause mass renormalization for +the physical B + + align:start position:0% + + + + align:start position:0% + +on so if you think about our lowest + + align:start position:0% +on so if you think about our lowest + + + align:start position:0% +on so if you think about our lowest +order relation as where we + + align:start position:0% +order relation as where we + + + align:start position:0% +order relation as where we +started let me write that as m0 + + align:start position:0% +started let me write that as m0 + + + align:start position:0% +started let me write that as m0 +s is 4 + + align:start position:0% +s is 4 + + + align:start position:0% +s is 4 +V 0 over + + align:start position:0% + + + + align:start position:0% + +f^2 mu plus + + align:start position:0% + + + + align:start position:0% + +MD sometimes people call + + align:start position:0% +MD sometimes people call + + + align:start position:0% +MD sometimes people call +this well making up more + + align:start position:0% + + + + align:start position:0% + +notation yeah which I'll use in a + + align:start position:0% +notation yeah which I'll use in a + + + align:start position:0% +notation yeah which I'll use in a +minute and so if you actually calculate + + align:start position:0% +minute and so if you actually calculate + + + align:start position:0% +minute and so if you actually calculate +this Loop then you get a correction to + + align:start position:0% +this Loop then you get a correction to + + + align:start position:0% +this Loop then you get a correction to +that formula that this would have BM pi^ + + align:start position:0% +that formula that this would have BM pi^ + + + align:start position:0% +that formula that this would have BM pi^ +squ but you would get a correction if + + align:start position:0% +squ but you would get a correction if + + + align:start position:0% +squ but you would get a correction if +you did it in + + align:start position:0% + + + + align:start position:0% + +su2 just to keep the formula a little + + align:start position:0% +su2 just to keep the formula a little + + + align:start position:0% +su2 just to keep the formula a little +simpler then it would look like + + align:start position:0% + + + + align:start position:0% + +this so m0 is like the pon Mass but the + + align:start position:0% +this so m0 is like the pon Mass but the + + + align:start position:0% +this so m0 is like the pon Mass but the +pon mass at lowest order in the Carl + + align:start position:0% +pon mass at lowest order in the Carl + + + align:start position:0% +pon mass at lowest order in the Carl +expansion so it's not the physical P + + align:start position:0% + + + + align:start position:0% + +Mass so 2 L4 bar in theory 2 with two + + align:start position:0% +Mass so 2 L4 bar in theory 2 with two + + + align:start position:0% +Mass so 2 L4 bar in theory 2 with two +flavors two + + align:start position:0% +flavors two + + + align:start position:0% +flavors two +su2 plus an L5 bar minus 4 an L6 + + align:start position:0% +su2 plus an L5 bar minus 4 an L6 + + + align:start position:0% +su2 plus an L5 bar minus 4 an L6 +bar so these various coefficients are + + align:start position:0% +bar so these various coefficients are + + + align:start position:0% +bar so these various coefficients are +coming in with some numbers in front + + align:start position:0% +coming in with some numbers in front + + + align:start position:0% +coming in with some numbers in front +some combination of + + align:start position:0% +some combination of + + + align:start position:0% +some combination of +them and then there's a contribution + + align:start position:0% +them and then there's a contribution + + + align:start position:0% +them and then there's a contribution +from a kyal loop and if I take away that + + align:start position:0% +from a kyal loop and if I take away that + + + align:start position:0% +from a kyal loop and if I take away that +one it's just a kyl + + align:start position:0% +one it's just a kyl + + + align:start position:0% +one it's just a kyl +logarithm so this is 4 + + align:start position:0% +logarithm so this is 4 + + + align:start position:0% +logarithm so this is 4 +Pi f^ + + align:start position:0% +Pi f^ + + + align:start position:0% +Pi f^ +2 log m 0^ 2 over mu^ + + align:start position:0% + + + + align:start position:0% + +2 there would be an extra term with just + + align:start position:0% +2 there would be an extra term with just + + + align:start position:0% +2 there would be an extra term with just +plus one time this if I hadn't gotten + + align:start position:0% +plus one time this if I hadn't gotten + + + align:start position:0% +plus one time this if I hadn't gotten +rid of that or minus one times that okay + + align:start position:0% +rid of that or minus one times that okay + + + align:start position:0% +rid of that or minus one times that okay +so this is from the loop this is from + + align:start position:0% +so this is from the loop this is from + + + align:start position:0% +so this is from the loop this is from +the explicit four dimension operators + + align:start position:0% +the explicit four dimension operators + + + align:start position:0% +the explicit four dimension operators +that were of the higher Dimension some + + align:start position:0% +that were of the higher Dimension some + + + align:start position:0% +that were of the higher Dimension some +combination of them the Divergence the + + align:start position:0% +combination of them the Divergence the + + + align:start position:0% +combination of them the Divergence the +UV Divergence is absorbed in you know + + align:start position:0% +UV Divergence is absorbed in you know + + + align:start position:0% +UV Divergence is absorbed in you know +some combination of them and if you want + + align:start position:0% +some combination of them and if you want + + + align:start position:0% +some combination of them and if you want +to figure out exactly how the UV + + align:start position:0% +to figure out exactly how the UV + + + align:start position:0% +to figure out exactly how the UV +divergences go between this then you got + + align:start position:0% +divergences go between this then you got + + + align:start position:0% +divergences go between this then you got +to think of re normalizing more than + + align:start position:0% +to think of re normalizing more than + + + align:start position:0% +to think of re normalizing more than +just this + + align:start position:0% +just this + + + align:start position:0% +just this +diagram uh and you can generically think + + align:start position:0% +diagram uh and you can generically think + + + align:start position:0% +diagram uh and you can generically think +of observables as having this kind of + + align:start position:0% +of observables as having this kind of + + + align:start position:0% +of observables as having this kind of +expansion in in uh mu and MD so if you + + align:start position:0% +expansion in in uh mu and MD so if you + + + align:start position:0% +expansion in in uh mu and MD so if you +like you should think of m0 here as + + align:start position:0% +like you should think of m0 here as + + + align:start position:0% +like you should think of m0 here as +really just m up and plus M down this is + + align:start position:0% +really just m up and plus M down this is + + + align:start position:0% +really just m up and plus M down this is +saying at lowest or in car peration + + align:start position:0% +saying at lowest or in car peration + + + align:start position:0% +saying at lowest or in car peration +Theory there's a linear term but + + align:start position:0% +Theory there's a linear term but + + + align:start position:0% +Theory there's a linear term but +then here there's an m0 to the 4th term + + align:start position:0% +then here there's an m0 to the 4th term + + + align:start position:0% +then here there's an m0 to the 4th term +which is quadratic and the Quark masses + + align:start position:0% +which is quadratic and the Quark masses + + + align:start position:0% +which is quadratic and the Quark masses +and there's also a quadratic term from + + align:start position:0% +and there's also a quadratic term from + + + align:start position:0% +and there's also a quadratic term from +the + + align:start position:0% +the + + + align:start position:0% +the +loops so you have an exp manine in the + + align:start position:0% +loops so you have an exp manine in the + + + align:start position:0% +loops so you have an exp manine in the +quk masses think of m0 as the quk masses + + align:start position:0% +quk masses think of m0 as the quk masses + + + align:start position:0% +quk masses think of m0 as the quk masses +and M Pi is the meeson mass okay and + + align:start position:0% +and M Pi is the meeson mass okay and + + + align:start position:0% +and M Pi is the meeson mass okay and +this is I just give you the example of + + align:start position:0% +this is I just give you the example of + + + align:start position:0% +this is I just give you the example of +the P Mass but this is generically true + + align:start position:0% +the P Mass but this is generically true + + + align:start position:0% +the P Mass but this is generically true +for observables that you might calculate + + align:start position:0% +for observables that you might calculate + + + align:start position:0% +for observables that you might calculate +that they have this type of result where + + align:start position:0% +that they have this type of result where + + + align:start position:0% +that they have this type of result where +you have an + + align:start position:0% +you have an + + + align:start position:0% +you have an +expansion is there any physical reason + + align:start position:0% +expansion is there any physical reason + + + align:start position:0% +expansion is there any physical reason +for why the square the mass square of + + align:start position:0% + + + + align:start position:0% + +the so you one way of saying it is yes + + align:start position:0% +the so you one way of saying it is yes + + + align:start position:0% +the so you one way of saying it is yes +you might think well why is it not M pi + + align:start position:0% +you might think well why is it not M pi + + + align:start position:0% +you might think well why is it not M pi +equals muu and MD and the glib way of + + align:start position:0% +equals muu and MD and the glib way of + + + align:start position:0% +equals muu and MD and the glib way of +saying it is well if you think about M + + align:start position:0% +saying it is well if you think about M + + + align:start position:0% +saying it is well if you think about M +pi^ squ and you think about it having an + + align:start position:0% +pi^ squ and you think about it having an + + + align:start position:0% +pi^ squ and you think about it having an +expansion then it could have a constant + + align:start position:0% +expansion then it could have a constant + + + align:start position:0% +expansion then it could have a constant +plus linear term plus quadratic term you + + align:start position:0% +plus linear term plus quadratic term you + + + align:start position:0% +plus linear term plus quadratic term you +don't have the constant because of the + + align:start position:0% +don't have the constant because of the + + + align:start position:0% +don't have the constant because of the +chyro symmetry so the linear term is the + + align:start position:0% +chyro symmetry so the linear term is the + + + align:start position:0% +chyro symmetry so the linear term is the +first thing that's + + align:start position:0% +first thing that's + + + align:start position:0% +first thing that's +allowed that's a one way of saying it I + + align:start position:0% +allowed that's a one way of saying it I + + + align:start position:0% +allowed that's a one way of saying it I +mean if you think about it in the + + align:start position:0% +mean if you think about it in the + + + align:start position:0% +mean if you think about it in the +bosonic theory we have Gran quadratic in + + align:start position:0% +bosonic theory we have Gran quadratic in + + + align:start position:0% +bosonic theory we have Gran quadratic in +in masses right whereas in the fironic + + align:start position:0% +in masses right whereas in the fironic + + + align:start position:0% +in masses right whereas in the fironic +theory you have in masses and that's + + align:start position:0% +theory you have in masses and that's + + + align:start position:0% +theory you have in masses and that's +also part of what what it had to do with + + align:start position:0% +also part of what what it had to do with + + + align:start position:0% +also part of what what it had to do with +but it's really a combination of + + align:start position:0% +but it's really a combination of + + + align:start position:0% +but it's really a combination of +symmetry breaking and and + + align:start position:0% + + + + align:start position:0% + +that it's allowed so it + + align:start position:0% +that it's allowed so it + + + align:start position:0% +that it's allowed so it +happens just kind of the bottom line but + + align:start position:0% +happens just kind of the bottom line but + + + align:start position:0% +happens just kind of the bottom line but +it's allowed by the + + align:start position:0% + + + + align:start position:0% + +symmetries okay and so finally I this is + + align:start position:0% +symmetries okay and so finally I this is + + + align:start position:0% +symmetries okay and so finally I this is +the example I'm actually going to get + + align:start position:0% +the example I'm actually going to get + + + align:start position:0% +the example I'm actually going to get +you to + + align:start position:0% + + + + align:start position:0% + +do so have you look on the on the + + align:start position:0% +do so have you look on the on the + + + align:start position:0% +do so have you look on the on the +problem set at Decay constants and they + + align:start position:0% +problem set at Decay constants and they + + + align:start position:0% +problem set at Decay constants and they +have an analogous result to that one + + align:start position:0% +have an analogous result to that one + + + align:start position:0% +have an analogous result to that one +you'll do the calculation in + + align:start position:0% +you'll do the calculation in + + + align:start position:0% +you'll do the calculation in +su3 and the kind of result that you + + align:start position:0% +su3 and the kind of result that you + + + align:start position:0% +su3 and the kind of result that you +should expect to + + align:start position:0% +should expect to + + + align:start position:0% +should expect to +get is something that looks like + + align:start position:0% + + + + align:start position:0% + +this so I'm using this b0o notation that + + align:start position:0% +this so I'm using this b0o notation that + + + align:start position:0% +this so I'm using this b0o notation that +I introduced over there + + align:start position:0% +I introduced over there + + + align:start position:0% +I introduced over there +just so I could write it all in one + + align:start position:0% + + + + align:start position:0% + +line and these M's with the subscript I + + align:start position:0% +line and these M's with the subscript I + + + align:start position:0% +line and these M's with the subscript I +are just some shorthand for some + + align:start position:0% +are just some shorthand for some + + + align:start position:0% +are just some shorthand for some +contributions coming from + + align:start position:0% + + + + align:start position:0% + +loops and + + align:start position:0% +loops and + + + align:start position:0% +loops and +F is the result + + align:start position:0% + + + + align:start position:0% + +in the in + + align:start position:0% + + + + align:start position:0% + +l0 so l f is the parameter in + + align:start position:0% + + + + align:start position:0% + +l0 whereas F Pi is the physical Decay + + align:start position:0% +l0 whereas F Pi is the physical Decay + + + align:start position:0% +l0 whereas F Pi is the physical Decay +constant of the + + align:start position:0% + + + + align:start position:0% + +pon + + align:start position:0% +pon + + + align:start position:0% +pon +so one result which is encoded in this + + align:start position:0% +so one result which is encoded in this + + + align:start position:0% +so one result which is encoded in this +formula is that the lran parameter is + + align:start position:0% +formula is that the lran parameter is + + + align:start position:0% +formula is that the lran parameter is +actually equal to the Decay constant at + + align:start position:0% +actually equal to the Decay constant at + + + align:start position:0% +actually equal to the Decay constant at +lowest order power privation Theory + + align:start position:0% +lowest order power privation Theory + + + align:start position:0% +lowest order power privation Theory +that's something I didn't cover I cover + + align:start position:0% +that's something I didn't cover I cover + + + align:start position:0% +that's something I didn't cover I cover +it when I teach Quantum field Theory 3 + + align:start position:0% +it when I teach Quantum field Theory 3 + + + align:start position:0% +it when I teach Quantum field Theory 3 +you can look at my notes to see that + + align:start position:0% +you can look at my notes to see that + + + align:start position:0% +you can look at my notes to see that +derivation those of you that take yeah + + align:start position:0% +derivation those of you that take yeah + + + align:start position:0% +derivation those of you that take yeah +have taken qf3 from me you've already + + align:start position:0% +have taken qf3 from me you've already + + + align:start position:0% +have taken qf3 from me you've already +seen that and basically what I'm asking + + align:start position:0% +seen that and basically what I'm asking + + + align:start position:0% +seen that and basically what I'm asking +for on the problem set is I guide you + + align:start position:0% +for on the problem set is I guide you + + + align:start position:0% +for on the problem set is I guide you +with several parts but and how to think + + align:start position:0% +with several parts but and how to think + + + align:start position:0% +with several parts but and how to think +about these high order terms what are + + align:start position:0% +about these high order terms what are + + + align:start position:0% +about these high order terms what are +the loop graph contributions how do you + + align:start position:0% +the loop graph contributions how do you + + + align:start position:0% +the loop graph contributions how do you +get these terms from the high order L + + align:start position:0% +get these terms from the high order L + + + align:start position:0% +get these terms from the high order L +Grans how do you put it all together + + align:start position:0% +Grans how do you put it all together + + + align:start position:0% +Grans how do you put it all together +it's a nice example of this use of K + + align:start position:0% +it's a nice example of this use of K + + + align:start position:0% +it's a nice example of this use of K +pration Theory + + align:start position:0% +pration Theory + + + align:start position:0% +pration Theory +and again we see that a physical + + align:start position:0% +and again we see that a physical + + + align:start position:0% +and again we see that a physical +observable which is this Decay constant + + align:start position:0% +observable which is this Decay constant + + + align:start position:0% +observable which is this Decay constant +has a chyal expansion and the thing that + + align:start position:0% +has a chyal expansion and the thing that + + + align:start position:0% +has a chyal expansion and the thing that +KY pration theory is is actually doing + + align:start position:0% +KY pration theory is is actually doing + + + align:start position:0% +KY pration theory is is actually doing +is allowing you to predict both the form + + align:start position:0% +is allowing you to predict both the form + + + align:start position:0% +is allowing you to predict both the form +of that expansion as well as these + + align:start position:0% +of that expansion as well as these + + + align:start position:0% +of that expansion as well as these +things here which are called chyo + + align:start position:0% +things here which are called chyo + + + align:start position:0% +things here which are called chyo +logarithms so if you ask about + + align:start position:0% +logarithms so if you ask about + + + align:start position:0% +logarithms so if you ask about +predictive power the polinomial terms + + align:start position:0% +predictive power the polinomial terms + + + align:start position:0% +predictive power the polinomial terms +terms of higher order in the cork masses + + align:start position:0% +terms of higher order in the cork masses + + + align:start position:0% +terms of higher order in the cork masses +that are polinomial you end up having + + align:start position:0% +that are polinomial you end up having + + + align:start position:0% +that are polinomial you end up having +unknown coefficients but the terms with + + align:start position:0% +unknown coefficients but the terms with + + + align:start position:0% +unknown coefficients but the terms with +logarithms have coefficients which are + + align:start position:0% +logarithms have coefficients which are + + + align:start position:0% +logarithms have coefficients which are +fixed your lower lower order lran so + + align:start position:0% +fixed your lower lower order lran so + + + align:start position:0% +fixed your lower lower order lran so +those are things that you predict with + + align:start position:0% +those are things that you predict with + + + align:start position:0% +those are things that you predict with +the K pration + + align:start position:0% +the K pration + + + align:start position:0% +the K pration +Theory when people do lattice + + align:start position:0% +Theory when people do lattice + + + align:start position:0% +Theory when people do lattice +calculations they need to do K + + align:start position:0% +calculations they need to do K + + + align:start position:0% +calculations they need to do K +extrapolations and then they're using + + align:start position:0% +extrapolations and then they're using + + + align:start position:0% +extrapolations and then they're using +formulas like this + + align:start position:0% + + + + align:start position:0% + +one okay so any questions about + + align:start position:0% + + + + align:start position:0% + +that mass the physical Mass this is the + + align:start position:0% +that mass the physical Mass this is the + + + align:start position:0% +that mass the physical Mass this is the +physical Mass this is the cork masses m0 + + align:start position:0% +physical Mass this is the cork masses m0 + + + align:start position:0% +physical Mass this is the cork masses m0 +is just this combination with M up and M + + align:start position:0% +is just this combination with M up and M + + + align:start position:0% +is just this combination with M up and M +down Okay so mu dependence cancel + + align:start position:0% +down Okay so mu dependence cancel + + + align:start position:0% +down Okay so mu dependence cancel +between and the MU dependence cancels + + align:start position:0% +between and the MU dependence cancels + + + align:start position:0% +between and the MU dependence cancels +because these guys all depend on + + align:start position:0% +because these guys all depend on + + + align:start position:0% +because these guys all depend on +me + + align:start position:0% +me + + + align:start position:0% +me +yeah and same thing + + align:start position:0% +yeah and same thing + + + align:start position:0% +yeah and same thing +here these guys depend on + + align:start position:0% + + + + align:start position:0% + +me here I have just enough room to make + + align:start position:0% +me here I have just enough room to make + + + align:start position:0% +me here I have just enough room to make +That + + align:start position:0% + + + + align:start position:0% + +explicit okay so that actually covers + + align:start position:0% +explicit okay so that actually covers + + + align:start position:0% +explicit okay so that actually covers +all the goals that we had for cation + + align:start position:0% +all the goals that we had for cation + + + align:start position:0% +all the goals that we had for cation +Theory though it's a fun topic and + + align:start position:0% +Theory though it's a fun topic and + + + align:start position:0% +Theory though it's a fun topic and +there's many more things we could + + align:start position:0% +there's many more things we could + + + align:start position:0% +there's many more things we could +discuss but that's what we needed to do + + align:start position:0% +discuss but that's what we needed to do + + + align:start position:0% +discuss but that's what we needed to do +discuss and so we're going to move + + align:start position:0% +discuss and so we're going to move + + + align:start position:0% +discuss and so we're going to move +on so the next thing I want to talk + + align:start position:0% +on so the next thing I want to talk + + + align:start position:0% +on so the next thing I want to talk +about as an example of effective field + + align:start position:0% +about as an example of effective field + + + align:start position:0% +about as an example of effective field +theory is heavy Quark effective + + align:start position:0% + + + + align:start position:0% + +Theory so again what are our goals with + + align:start position:0% +Theory so again what are our goals with + + + align:start position:0% +Theory so again what are our goals with +this effective Theory + + align:start position:0% + + + + align:start position:0% + +we will see some new features showing up + + align:start position:0% +we will see some new features showing up + + + align:start position:0% +we will see some new features showing up +that we haven't seen + + align:start position:0% + + + + align:start position:0% + +before we will find out what it means to + + align:start position:0% +before we will find out what it means to + + + align:start position:0% +before we will find out what it means to +take a lran that has labeled + + align:start position:0% + + + + align:start position:0% + +Fields we'll spend a little bit of time + + align:start position:0% +Fields we'll spend a little bit of time + + + align:start position:0% +Fields we'll spend a little bit of time +on symmetry + + align:start position:0% +on symmetry + + + align:start position:0% +on symmetry +because in this heavy quk effective + + align:start position:0% +because in this heavy quk effective + + + align:start position:0% +because in this heavy quk effective +Theory there's actually something called + + align:start position:0% +Theory there's actually something called + + + align:start position:0% +Theory there's actually something called +heavy quk symmetry which is not apparent + + align:start position:0% +heavy quk symmetry which is not apparent + + + align:start position:0% +heavy quk symmetry which is not apparent +in qcd but becomes apparent in this + + align:start position:0% +in qcd but becomes apparent in this + + + align:start position:0% +in qcd but becomes apparent in this +Theory and there's a trick known as + + align:start position:0% +Theory and there's a trick known as + + + align:start position:0% +Theory and there's a trick known as +using coent + + align:start position:0% +using coent + + + align:start position:0% +using coent +representations in order to encode + + align:start position:0% +representations in order to encode + + + align:start position:0% +representations in order to encode +symmetry predictions and it's a very + + align:start position:0% +symmetry predictions and it's a very + + + align:start position:0% +symmetry predictions and it's a very +powerful thing that's not special to + + align:start position:0% +powerful thing that's not special to + + + align:start position:0% +powerful thing that's not special to +this Theory but you could use it in + + align:start position:0% +this Theory but you could use it in + + + align:start position:0% +this Theory but you could use it in +general and I want to teach it to you so + + align:start position:0% +general and I want to teach it to you so + + + align:start position:0% +general and I want to teach it to you so +that's one thing we'll + + align:start position:0% + + + + align:start position:0% + +do it's kind of like a spion analysis + + align:start position:0% +do it's kind of like a spion analysis + + + align:start position:0% +do it's kind of like a spion analysis +but a little bit more + + align:start position:0% + + + + align:start position:0% + +powerful and finally anomalous + + align:start position:0% +powerful and finally anomalous + + + align:start position:0% +powerful and finally anomalous +Dimensions that are functions is + + align:start position:0% +Dimensions that are functions is + + + align:start position:0% +Dimensions that are functions is +something that will show up + + align:start position:0% +something that will show up + + + align:start position:0% +something that will show up +here not just + + align:start position:0% +here not just + + + align:start position:0% +here not just +numbers there's something called + + align:start position:0% +numbers there's something called + + + align:start position:0% +numbers there's something called +reparameterization + + align:start position:0% + + + + align:start position:0% + +invariance which you can think of as a + + align:start position:0% +invariance which you can think of as a + + + align:start position:0% +invariance which you can think of as a +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +symmetry that we'll talk about + + align:start position:0% +symmetry that we'll talk about + + + align:start position:0% +symmetry that we'll talk about +and + + align:start position:0% + + + + align:start position:0% + +finally if that list is not long enough + + align:start position:0% +finally if that list is not long enough + + + align:start position:0% +finally if that list is not long enough +we'll add one more + + align:start position:0% +we'll add one more + + + align:start position:0% +we'll add one more +thing which I hinted + + align:start position:0% +thing which I hinted + + + align:start position:0% +thing which I hinted +at + + align:start position:0% +at + + + align:start position:0% +at +so I said when we talked about msar that + + align:start position:0% +so I said when we talked about msar that + + + align:start position:0% +so I said when we talked about msar that +it wasn't a perfect scheme for doing + + align:start position:0% +it wasn't a perfect scheme for doing + + + align:start position:0% +it wasn't a perfect scheme for doing +things that there were some limitations + + align:start position:0% +things that there were some limitations + + + align:start position:0% +things that there were some limitations +and we'll come at the end of this + + align:start position:0% +and we'll come at the end of this + + + align:start position:0% +and we'll come at the end of this +chapter to what those limitations + + align:start position:0% + + + + align:start position:0% + +are the limitations come from Power like + + align:start position:0% +are the limitations come from Power like + + + align:start position:0% +are the limitations come from Power like +scale + + align:start position:0% +scale + + + align:start position:0% +scale +separation and that's related to + + align:start position:0% +separation and that's related to + + + align:start position:0% +separation and that's related to +something called re normal + + align:start position:0% +something called re normal + + + align:start position:0% +something called re normal +on so we'll learn whatever normal on + + align:start position:0% +on so we'll learn whatever normal on + + + align:start position:0% +on so we'll learn whatever normal on +is and why it has something to do with + + align:start position:0% +is and why it has something to do with + + + align:start position:0% +is and why it has something to do with +the failure of msar and how one can get + + align:start position:0% +the failure of msar and how one can get + + + align:start position:0% +the failure of msar and how one can get +around that failure and how one actually + + align:start position:0% +around that failure and how one actually + + + align:start position:0% +around that failure and how one actually +needs to get around that failure in some + + align:start position:0% +needs to get around that failure in some + + + align:start position:0% +needs to get around that failure in some +cases okay so that's the the list of + + align:start position:0% +cases okay so that's the the list of + + + align:start position:0% +cases okay so that's the the list of +goals in kind of in some ways in order + + align:start position:0% +goals in kind of in some ways in order + + + align:start position:0% +goals in kind of in some ways in order +of importance + + align:start position:0% +of importance + + + align:start position:0% +of importance +actually so when we think about heavy + + align:start position:0% +actually so when we think about heavy + + + align:start position:0% +actually so when we think about heavy +Quirk effective Theory you shouldn't + + align:start position:0% +Quirk effective Theory you shouldn't + + + align:start position:0% +Quirk effective Theory you shouldn't +think about it as just something that + + align:start position:0% +think about it as just something that + + + align:start position:0% +think about it as just something that +you would need to do if you wanted to do + + align:start position:0% +you would need to do if you wanted to do + + + align:start position:0% +you would need to do if you wanted to do +heavy quk physics because the idea of + + align:start position:0% +heavy quk physics because the idea of + + + align:start position:0% +heavy quk physics because the idea of +what we're doing here is much more + + align:start position:0% +what we're doing here is much more + + + align:start position:0% +what we're doing here is much more +General than that the idea of what we're + + align:start position:0% +General than that the idea of what we're + + + align:start position:0% +General than that the idea of what we're +doing here is we're saying take a heavy + + align:start position:0% +doing here is we're saying take a heavy + + + align:start position:0% +doing here is we're saying take a heavy +particle and think about what happens if + + align:start position:0% +particle and think about what happens if + + + align:start position:0% +particle and think about what happens if +I tickle + + align:start position:0% +I tickle + + + align:start position:0% +I tickle +it and that heavy particle could be a + + align:start position:0% +it and that heavy particle could be a + + + align:start position:0% +it and that heavy particle could be a +heavy + + align:start position:0% +heavy + + + align:start position:0% +heavy +Source some + + align:start position:0% +Source some + + + align:start position:0% +Source some +Theory we'll talk about it in the + + align:start position:0% +Theory we'll talk about it in the + + + align:start position:0% +Theory we'll talk about it in the +context of them being heavy quarks but + + align:start position:0% +context of them being heavy quarks but + + + align:start position:0% +context of them being heavy quarks but +you should really think of it as any + + align:start position:0% +you should really think of it as any + + + align:start position:0% +you should really think of it as any +heavy particle + + align:start position:0% +heavy particle + + + align:start position:0% +heavy particle +tickled by light + + align:start position:0% + + + + align:start position:0% + +particles and what we really + + align:start position:0% +particles and what we really + + + align:start position:0% +particles and what we really +mean is that we want to study the heavy + + align:start position:0% +mean is that we want to study the heavy + + + align:start position:0% +mean is that we want to study the heavy +particle and since we want to study it + + align:start position:0% +particle and since we want to study it + + + align:start position:0% +particle and since we want to study it +we better not remove it from the theory + + align:start position:0% + + + + align:start position:0% + +so we want to tickle it with light + + align:start position:0% +so we want to tickle it with light + + + align:start position:0% +so we want to tickle it with light +degrees of freedom with light small + + align:start position:0% +degrees of freedom with light small + + + align:start position:0% +degrees of freedom with light small +momentum transfer but we don't want to + + align:start position:0% +momentum transfer but we don't want to + + + align:start position:0% +momentum transfer but we don't want to +integrate that particle + + align:start position:0% +integrate that particle + + + align:start position:0% +integrate that particle +out so another way of saying this if you + + align:start position:0% +out so another way of saying this if you + + + align:start position:0% +out so another way of saying this if you +don't want to think of it as a heavy + + align:start position:0% +don't want to think of it as a heavy + + + align:start position:0% +don't want to think of it as a heavy +particle is that you have some + + align:start position:0% +particle is that you have some + + + align:start position:0% +particle is that you have some +source and that Source can be tickled + + align:start position:0% +source and that Source can be tickled + + + align:start position:0% +source and that Source can be tickled +and could + + align:start position:0% +and could + + + align:start position:0% +and could +wiggle but it's sort of mostly just a + + align:start position:0% +wiggle but it's sort of mostly just a + + + align:start position:0% +wiggle but it's sort of mostly just a +static source and then it could wiggle + + align:start position:0% +static source and then it could wiggle + + + align:start position:0% +static source and then it could wiggle +and that's what this is an effective + + align:start position:0% +and that's what this is an effective + + + align:start position:0% +and that's what this is an effective +field theory for so we'll talk about it + + align:start position:0% +field theory for so we'll talk about it + + + align:start position:0% +field theory for so we'll talk about it +in the context of heavy cork effective + + align:start position:0% +in the context of heavy cork effective + + + align:start position:0% +in the context of heavy cork effective +Theory and some of the things like heavy + + align:start position:0% +Theory and some of the things like heavy + + + align:start position:0% +Theory and some of the things like heavy +qu symmetry will be special to that + + align:start position:0% +qu symmetry will be special to that + + + align:start position:0% +qu symmetry will be special to that +theory but more generally the kind of + + align:start position:0% +theory but more generally the kind of + + + align:start position:0% +theory but more generally the kind of +approach we're taking is a more General + + align:start position:0% + + + + align:start position:0% + +thing so what's heavy Quark effective + + align:start position:0% +thing so what's heavy Quark effective + + + align:start position:0% +thing so what's heavy Quark effective +Theory so you have a heavy quark and you + + align:start position:0% +Theory so you have a heavy quark and you + + + align:start position:0% +Theory so you have a heavy quark and you +have it sitting in a bound state which + + align:start position:0% +have it sitting in a bound state which + + + align:start position:0% +have it sitting in a bound state which +is + + align:start position:0% + + + + align:start position:0% + +aeson so that means it's surrounded by + + align:start position:0% +aeson so that means it's surrounded by + + + align:start position:0% +aeson so that means it's surrounded by +light degrees of freedom one heavy Quark + + align:start position:0% +light degrees of freedom one heavy Quark + + + align:start position:0% +light degrees of freedom one heavy Quark +lots of light + + align:start position:0% +lots of light + + + align:start position:0% +lots of light +junk in the Quark model you'd say it's a + + align:start position:0% +junk in the Quark model you'd say it's a + + + align:start position:0% +junk in the Quark model you'd say it's a +qar q a heavy cork capital Q and A light + + align:start position:0% +qar q a heavy cork capital Q and A light + + + align:start position:0% +qar q a heavy cork capital Q and A light +cork little + + align:start position:0% + + + + align:start position:0% + +Q like b d which is the + + align:start position:0% +Q like b d which is the + + + align:start position:0% +Q like b d which is the +b0 but that's just a quark model uh + + align:start position:0% +b0 but that's just a quark model uh + + + align:start position:0% +b0 but that's just a quark model uh +approximation for what the degrees of + + align:start position:0% +approximation for what the degrees of + + + align:start position:0% +approximation for what the degrees of +freedom are and there's many more pairs + + align:start position:0% +freedom are and there's many more pairs + + + align:start position:0% +freedom are and there's many more pairs +of QQ bars and gluons that are really + + align:start position:0% +of QQ bars and gluons that are really + + + align:start position:0% +of QQ bars and gluons that are really +forming this hydronic + + align:start position:0% + + + + align:start position:0% + +state so you'd like to be able to make + + align:start position:0% +state so you'd like to be able to make + + + align:start position:0% +state so you'd like to be able to make +model independent predictions for that + + align:start position:0% +model independent predictions for that + + + align:start position:0% +model independent predictions for that +without having to worry about the fact + + align:start position:0% +without having to worry about the fact + + + align:start position:0% +without having to worry about the fact +that you're not parameterizing + + align:start position:0% +that you're not parameterizing + + + align:start position:0% +that you're not parameterizing +properly that stuff but you can't + + align:start position:0% +properly that stuff but you can't + + + align:start position:0% +properly that stuff but you can't +calculate and you can do that using + + align:start position:0% +calculate and you can do that using + + + align:start position:0% +calculate and you can do that using +effective field + + align:start position:0% +effective field + + + align:start position:0% +effective field +Theory there's two scales in the problem + + align:start position:0% +Theory there's two scales in the problem + + + align:start position:0% +Theory there's two scales in the problem +there's the size of this thing the + + align:start position:0% +there's the size of this thing the + + + align:start position:0% +there's the size of this thing the +inverse size is of order Lambda qcd + + align:start position:0% +inverse size is of order Lambda qcd + + + align:start position:0% +inverse size is of order Lambda qcd +that's the hyron hyron isation that + + align:start position:0% +that's the hyron hyron isation that + + + align:start position:0% +that's the hyron hyron isation that +scale and that's a scale that's much + + align:start position:0% +scale and that's a scale that's much + + + align:start position:0% +scale and that's a scale that's much +less than the cork Mass so you're really + + align:start position:0% +less than the cork Mass so you're really + + + align:start position:0% +less than the cork Mass so you're really +just expanding in Lambda qcd ided mq + + align:start position:0% +just expanding in Lambda qcd ided mq + + + align:start position:0% +just expanding in Lambda qcd ided mq +that's what this effective Theory will + + align:start position:0% + + + + align:start position:0% + +be and what you want to describe + + align:start position:0% + + + + align:start position:0% + +are fluctuations of the heavy Quark due + + align:start position:0% +are fluctuations of the heavy Quark due + + + align:start position:0% +are fluctuations of the heavy Quark due +to the light + + align:start position:0% +to the light + + + align:start position:0% +to the light +quarks so you could think that this guy + + align:start position:0% +quarks so you could think that this guy + + + align:start position:0% +quarks so you could think that this guy +is so heavy he just sits in the middle + + align:start position:0% +is so heavy he just sits in the middle + + + align:start position:0% +is so heavy he just sits in the middle +of the the state and he's + + align:start position:0% +of the the state and he's + + + align:start position:0% +of the the state and he's +static and then he gets tickled by the + + align:start position:0% +static and then he gets tickled by the + + + align:start position:0% +static and then he gets tickled by the +light stuff that's flying and whizzing + + align:start position:0% +light stuff that's flying and whizzing + + + align:start position:0% +light stuff that's flying and whizzing +around and that's a reasonable + + align:start position:0% + + + + align:start position:0% + +picture so what we really want to do + + align:start position:0% +picture so what we really want to do + + + align:start position:0% +picture so what we really want to do +here is an example of top down effective + + align:start position:0% +here is an example of top down effective + + + align:start position:0% +here is an example of top down effective +field Theory again so going back to + + align:start position:0% + + + + align:start position:0% + +are like integrating out heavy particles + + align:start position:0% +are like integrating out heavy particles + + + align:start position:0% +are like integrating out heavy particles +but now we want to + + align:start position:0% +but now we want to + + + align:start position:0% +but now we want to +keep the the heavy particles in the + + align:start position:0% +keep the the heavy particles in the + + + align:start position:0% +keep the the heavy particles in the +theory not remove them but still we want + + align:start position:0% +theory not remove them but still we want + + + align:start position:0% +theory not remove them but still we want +to take a low energy limit of + + align:start position:0% + + + + align:start position:0% + +them so that means that we have to take + + align:start position:0% +them so that means that we have to take + + + align:start position:0% +them so that means that we have to take +a low energy + + align:start position:0% +a low energy + + + align:start position:0% +a low energy +limit of qcd which is /us mq + + align:start position:0% +limit of qcd which is /us mq + + + align:start position:0% +limit of qcd which is /us mq +q and you can see that part of the + + align:start position:0% +q and you can see that part of the + + + align:start position:0% +q and you can see that part of the +problem here is that the mq is + + align:start position:0% +problem here is that the mq is + + + align:start position:0% +problem here is that the mq is +upstairs which makes taking the limit + + align:start position:0% +upstairs which makes taking the limit + + + align:start position:0% +upstairs which makes taking the limit +not + + align:start position:0% +not + + + align:start position:0% +not +completely obvious in the case where we + + align:start position:0% +completely obvious in the case where we + + + align:start position:0% +completely obvious in the case where we +were doing the heavy bons we sort of saw + + align:start position:0% +were doing the heavy bons we sort of saw + + + align:start position:0% +were doing the heavy bons we sort of saw +that it was always in propagators and we + + align:start position:0% +that it was always in propagators and we + + + align:start position:0% +that it was always in propagators and we +could just think of since it's always + + align:start position:0% +could just think of since it's always + + + align:start position:0% +could just think of since it's always +their internal we just expand here we + + align:start position:0% +their internal we just expand here we + + + align:start position:0% +their internal we just expand here we +want to keep the Q in the theory so we + + align:start position:0% +want to keep the Q in the theory so we + + + align:start position:0% +want to keep the Q in the theory so we +have to really think about how we take + + align:start position:0% +have to really think about how we take + + + align:start position:0% +have to really think about how we take +this + + align:start position:0% +this + + + align:start position:0% +this +limit so let's start + + align:start position:0% + + + + align:start position:0% + +slowly and consider the propagator for a + + align:start position:0% +slowly and consider the propagator for a + + + align:start position:0% +slowly and consider the propagator for a +heavy + + align:start position:0% +heavy + + + align:start position:0% +heavy +quark and we'll come back to the lran + + align:start position:0% + + + + align:start position:0% + +and we'll consider it with some on shell + + align:start position:0% + + + + align:start position:0% + +momentum which the on shell we'll + + align:start position:0% +momentum which the on shell we'll + + + align:start position:0% +momentum which the on shell we'll +consider an on shell momentum to be + + align:start position:0% +consider an on shell momentum to be + + + align:start position:0% +consider an on shell momentum to be +parameterized in the following way so if + + align:start position:0% +parameterized in the following way so if + + + align:start position:0% +parameterized in the following way so if +I have an onshow momentum I'll say that + + align:start position:0% +I have an onshow momentum I'll say that + + + align:start position:0% +I have an onshow momentum I'll say that +P is equal to + + align:start position:0% +P is equal to + + + align:start position:0% +P is equal to +mqv so that p^2 is equal to mq^ S and + + align:start position:0% +mqv so that p^2 is equal to mq^ S and + + + align:start position:0% +mqv so that p^2 is equal to mq^ S and +this V is + + align:start position:0% +this V is + + + align:start position:0% +this V is +one so once I pull out the Mass + + align:start position:0% +one so once I pull out the Mass + + + align:start position:0% +one so once I pull out the Mass +Dimension mq the remaining thing I call + + align:start position:0% +Dimension mq the remaining thing I call + + + align:start position:0% +Dimension mq the remaining thing I call +V and that's just some parameter which + + align:start position:0% +V and that's just some parameter which + + + align:start position:0% +V and that's just some parameter which +squares to one on + + align:start position:0% +squares to one on + + + align:start position:0% +squares to one on +shell now if I have + + align:start position:0% +shell now if I have + + + align:start position:0% +shell now if I have +kicks which are from light degrees of + + align:start position:0% +kicks which are from light degrees of + + + align:start position:0% +kicks which are from light degrees of +freedom then I don't have exactly on + + align:start position:0% +freedom then I don't have exactly on + + + align:start position:0% +freedom then I don't have exactly on +shell so P mu is mqv which is like the + + align:start position:0% +shell so P mu is mqv which is like the + + + align:start position:0% +shell so P mu is mqv which is like the +on shell piece plus something small K + + align:start position:0% +on shell piece plus something small K + + + align:start position:0% +on shell piece plus something small K +mu and K mu is of order Lambda + + align:start position:0% +mu and K mu is of order Lambda + + + align:start position:0% +mu and K mu is of order Lambda +qcd so this is like saying the on shell + + align:start position:0% +qcd so this is like saying the on shell + + + align:start position:0% +qcd so this is like saying the on shell +piece + + align:start position:0% +piece + + + align:start position:0% +piece +plus the + + align:start position:0% + + + + align:start position:0% + +tickle and if I want to construct the + + align:start position:0% +tickle and if I want to construct the + + + align:start position:0% +tickle and if I want to construct the +propagator than the propagator is + + align:start position:0% +propagator than the propagator is + + + align:start position:0% +propagator than the propagator is +describing is encoding offshelf the + + align:start position:0% +describing is encoding offshelf the + + + align:start position:0% +describing is encoding offshelf the +offsh off shellness of the degree of + + align:start position:0% +offsh off shellness of the degree of + + + align:start position:0% +offsh off shellness of the degree of +Freedom it's one over the off + + align:start position:0% +Freedom it's one over the off + + + align:start position:0% +Freedom it's one over the off +shellness so it'll depend on the tickle + + align:start position:0% +shellness so it'll depend on the tickle + + + align:start position:0% +shellness so it'll depend on the tickle +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay so we could just take qcd + + align:start position:0% +okay so we could just take qcd + + + align:start position:0% +okay so we could just take qcd +propagator which is + + align:start position:0% + + + + align:start position:0% + +this and just plug in that + + align:start position:0% + + + + align:start position:0% + +formula when I Square the P there's mq^ + + align:start position:0% +formula when I Square the P there's mq^ + + + align:start position:0% +formula when I Square the P there's mq^ +squ which cancels this mq^ s + + align:start position:0% + + + + align:start position:0% + +and there's some cross terms that don't + + align:start position:0% +and there's some cross terms that don't + + + align:start position:0% +and there's some cross terms that don't +get + + align:start position:0% +get + + + align:start position:0% +get +cancelled so there's one that comes from + + align:start position:0% +cancelled so there's one that comes from + + + align:start position:0% +cancelled so there's one that comes from +this the dotproduct of the V do M with + + align:start position:0% +this the dotproduct of the V do M with + + + align:start position:0% +this the dotproduct of the V do M with +the K term that's this and then there's + + align:start position:0% +the K term that's this and then there's + + + align:start position:0% +the K term that's this and then there's +the K squ term so I have + + align:start position:0% +the K squ term so I have + + + align:start position:0% +the K squ term so I have +these and then I can expand + + align:start position:0% + + + + align:start position:0% + +that m is a positive quantity so it + + align:start position:0% +that m is a positive quantity so it + + + align:start position:0% +that m is a positive quantity so it +doesn't change the sign of the I zero + + align:start position:0% +doesn't change the sign of the I zero + + + align:start position:0% +doesn't change the sign of the I zero +and if I expand in M then the leading + + align:start position:0% +and if I expand in M then the leading + + + align:start position:0% +and if I expand in M then the leading +term looks like that it's m + + align:start position:0% +term looks like that it's m + + + align:start position:0% +term looks like that it's m +independent and then there's some order + + align:start position:0% +independent and then there's some order + + + align:start position:0% +independent and then there's some order +one over M terms which I could also look + + align:start position:0% +one over M terms which I could also look + + + align:start position:0% +one over M terms which I could also look +at what they + + align:start position:0% + + + + align:start position:0% + +are okay so that we could expand even + + align:start position:0% +are okay so that we could expand even + + + align:start position:0% +are okay so that we could expand even +though we don't a prior you know how to + + align:start position:0% +though we don't a prior you know how to + + + align:start position:0% +though we don't a prior you know how to +expand the + + align:start position:0% + + + + align:start position:0% + +lran we could also think about vertices + + align:start position:0% +lran we could also think about vertices + + + align:start position:0% +lran we could also think about vertices +in this Theory this is the propagator + + align:start position:0% +in this Theory this is the propagator + + + align:start position:0% +in this Theory this is the propagator +what about + + align:start position:0% +what about + + + align:start position:0% +what about +vertices and again this is a top down so + + align:start position:0% +vertices and again this is a top down so + + + align:start position:0% +vertices and again this is a top down so +we can think about vertices in q CD and + + align:start position:0% +we can think about vertices in q CD and + + + align:start position:0% +we can think about vertices in q CD and +just think about so if this is a heavy + + align:start position:0% +just think about so if this is a heavy + + + align:start position:0% +just think about so if this is a heavy +particle here we could think about + + align:start position:0% +particle here we could think about + + + align:start position:0% +particle here we could think about +what's kind of what would happen how do + + align:start position:0% +what's kind of what would happen how do + + + align:start position:0% +what's kind of what would happen how do +we expand + + align:start position:0% + + + + align:start position:0% + +those and there doesn't look like + + align:start position:0% +those and there doesn't look like + + + align:start position:0% +those and there doesn't look like +there's really anything going on here + + align:start position:0% +there's really anything going on here + + + align:start position:0% +there's really anything going on here +because there's nothing to expand but + + align:start position:0% +because there's nothing to expand but + + + align:start position:0% +because there's nothing to expand but +because these things are heavy particles + + align:start position:0% +because these things are heavy particles + + + align:start position:0% +because these things are heavy particles +here you realize from this the + + align:start position:0% +here you realize from this the + + + align:start position:0% +here you realize from this the +propagator formula here that you're + + align:start position:0% +propagator formula here that you're + + + align:start position:0% +propagator formula here that you're +going to have one plus v slashes on each + + align:start position:0% +going to have one plus v slashes on each + + + align:start position:0% +going to have one plus v slashes on each +side of this + + align:start position:0% +side of this + + + align:start position:0% +side of this +guy so for a propag on each + + align:start position:0% +guy so for a propag on each + + + align:start position:0% +guy so for a propag on each +side you can make a + + align:start position:0% + + + + align:start position:0% + +simplification and that's because 1 plus + + align:start position:0% +simplification and that's because 1 plus + + + align:start position:0% +simplification and that's because 1 plus +v SL over 2 gamma mu 1 + V SL over + + align:start position:0% +v SL over 2 gamma mu 1 + V SL over + + + align:start position:0% +v SL over 2 gamma mu 1 + V SL over +two after some dra algebra is just V + + align:start position:0% +two after some dra algebra is just V + + + align:start position:0% +two after some dra algebra is just V +mu Time 1 plus v over + + align:start position:0% +mu Time 1 plus v over + + + align:start position:0% +mu Time 1 plus v over +two so the gamma mu becomes a v mu + + align:start position:0% +two so the gamma mu becomes a v mu + + + align:start position:0% +two so the gamma mu becomes a v mu +so the + + align:start position:0% +so the + + + align:start position:0% +so the +verticy once you take that into account + + align:start position:0% +verticy once you take that into account + + + align:start position:0% +verticy once you take that into account +is just minus i g t a v + + align:start position:0% + + + + align:start position:0% + +mu and we can actually if we even if we + + align:start position:0% +mu and we can actually if we even if we + + + align:start position:0% +mu and we can actually if we even if we +don't think about starting with the qcd + + align:start position:0% +don't think about starting with the qcd + + + align:start position:0% +don't think about starting with the qcd +lran if this is our fan roll and that's + + align:start position:0% +lran if this is our fan roll and that's + + + align:start position:0% +lran if this is our fan roll and that's +our propagator we can write down an + + align:start position:0% +our propagator we can write down an + + + align:start position:0% +our propagator we can write down an +effective theory for + + align:start position:0% +effective theory for + + + align:start position:0% +effective theory for +that that gives those F and + + align:start position:0% +that that gives those F and + + + align:start position:0% +that that gives those F and +roles and that actually is the hqt LR + + align:start position:0% + + + + align:start position:0% + +so sorry for going a little bit over but + + align:start position:0% +so sorry for going a little bit over but + + + align:start position:0% +so sorry for going a little bit over but +I wanted to at least get a little bit + + align:start position:0% +I wanted to at least get a little bit + + + align:start position:0% +I wanted to at least get a little bit +into this okay so by construction this + + align:start position:0% +into this okay so by construction this + + + align:start position:0% +into this okay so by construction this +way we can arrive at this lran and next + + align:start position:0% +way we can arrive at this lran and next + + + align:start position:0% +way we can arrive at this lran and next +time I'll come back and I'll show you + + align:start position:0% +time I'll come back and I'll show you + + + align:start position:0% +time I'll come back and I'll show you +how you would we can really properly + + align:start position:0% +how you would we can really properly + + + align:start position:0% +how you would we can really properly +take this limit of the qcd lrin to get + + align:start position:0% +take this limit of the qcd lrin to get + + + align:start position:0% +take this limit of the qcd lrin to get +the same thing + + align:start position:0% +the same thing + + + align:start position:0% +the same thing +okay but that is the hqt the lowest + + align:start position:0% +okay but that is the hqt the lowest + + + align:start position:0% +okay but that is the hqt the lowest +order term of the hqt the gr sheet is + + align:start position:0% + + + + align:start position:0% + +this so it's a linear v.d coupling V is + + align:start position:0% +this so it's a linear v.d coupling V is + + + align:start position:0% +this so it's a linear v.d coupling V is +a parameter and so I've put it as a + + align:start position:0% +a parameter and so I've put it as a + + + align:start position:0% +a parameter and so I've put it as a +parameter on the fields we'll see more + + align:start position:0% +parameter on the fields we'll see more + + + align:start position:0% +parameter on the fields we'll see more +why that was done next time and there's + + align:start position:0% +why that was done next time and there's + + + align:start position:0% +why that was done next time and there's +a projection relation on the field if + + align:start position:0% +a projection relation on the field if + + + align:start position:0% +a projection relation on the field if +I'm using a four component field and I + + align:start position:0% +I'm using a four component field and I + + + align:start position:0% +I'm using a four component field and I +have this projection relation I could + + align:start position:0% +have this projection relation I could + + + align:start position:0% +have this projection relation I could +also write it in a two component + + align:start position:0% +also write it in a two component + + + align:start position:0% +also write it in a two component +notation and then I wouldn't need + + align:start position:0% +notation and then I wouldn't need + + + align:start position:0% +notation and then I wouldn't need +that but for four four component + + align:start position:0% +that but for four four component + + + align:start position:0% +that but for four four component +notation you do need that + + align:start position:0% +notation you do need that + + + align:start position:0% +notation you do need that +we'll talk more about that next time too \ No newline at end of file diff --git a/I3g7KRIvQPI.txt b/I3g7KRIvQPI.txt new file mode 100644 index 0000000000000000000000000000000000000000..b0a75652d1a15eef17681cff2edc6ddda2db77e8 --- /dev/null +++ b/I3g7KRIvQPI.txt @@ -0,0 +1,2171 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Please settle +down and take a + +look at this question. + +OK, let's take 10 seconds. + +I think that it's a simple math +mistake is between one + +and two at least. So, the trick +here is you know the p h + +and the p k a and you want to +find the ratio so you can + +subtract and do the log. + +So maybe we'll have this +question later or something + +similar and we can try +this one again. + +So we're going to talk about +buffers again today. + +I just feel the need to take +a moment and reflect on the + +historic events of the last 24 +hours, and talk about how it + +will affect chemistry. + +So some of you may have voted +for the first time. + +Some of you may have worked on a +campaign for the first time. + +Some of you may have been very +active in a campaign for the + +first time, either for +Obama or McCain, + +that you got involved. + +And I thought just to put this +election in a little bit of + +the historic perspective in +terms of about being an + +undergraduate student or a +student and working on a + +political campaign or being part +of a political movement. + +So, my father was very active +as a political student + +activist. But the difference +between some of you and my + +father was that he was a +political activist at the + +University of Hamberg in Germany +in the 1930's in + +Hitler's Germany. + +So he was the leader of +the left wing student + +organization. + +That was something that put +one's life at risk to take on + +that role at that time. + +So, things were heating up a +little bit and the gestapo + +were discussing some of the +activities with the left wing + +student leaders at college +campuses in Germany. + +And some of them, after the +discussions, no one knew where + +they went, they seemed +to disappear. + +Now my father was very concerned +about this and he + +decided to lay low for a while, +and so he thought I'll + +do a semester at another +university. + +And he told his parents that +if the gestapo came looking + +for him, that they should send +him a telegram saying "Your + +Aunt Millie is sick." Since he +did not have an Aunt Milly, he + +knew that that would +mean get out now. + +So he went to another university +and he was doing a + +semester there, and someone he +knew told him you really need + +to go into hiding. + +But he didn't really trust this +person, so we packed a + +bag with a few clothes and some +toiletries, but he didn't + +actually leave. Then the next +day he came home and there was + +a telegram under his door. + +So, you can guess what +the telegram said. + +He grabbed the bag that was +already packed and headed down + +the stairs. + +The gestapo was coming +up the stairs. + +My father's name was Heinz +Leopold Lushinski and the + +gestapo said to him, "Do you +know Herr Lushinski? + +And my father said, "Yes, of +course, he lives on the top + +floor." The gestapo went up, +my father went down, and he + +didn't go back to Germany +for 30 years. + +So he came to the United States +as a political refugee + +and became a citizen. + +He voted in every election, +every possibility, he was + +very, very active. + +My family was very, very +active in politics. + +He gave money every year to the +American Civil Liberties + +Union to protect civil +liberties, and he also gave + +money to the American +Rifle Association. + +He always liked to +have a plan b. + +So, it was sometimes a little +humbling to be the only child + +of this man. + +He was in his 50's when I was +born, and I thought how can I + +live up to something +like this? + +Am I ever going to risk my life +for what I believe in. + +If given that choice would +I do the right thing? + +And I don't know if I'll ever +get an answer to that + +question, but I talked to my +father about this and he said + +all I need to do is work hard, +find something that I love + +doing, some way that I can +contribute, and that's what's + +really important -- + +contributing is really important. + +So I was drawn to teaching, and +I love teaching here at + +MIT because you all are so +talented and smart, and it is + +really an honor and a privilege +to be involved in + +your education. + +But I feel that in the last 24 +hours, we have all received an + +additional call to service. + +That president elect Obama said +in the campaign that his + +top priorities are going to be +scientific research, coming up + +with clean energy technologies, +and improving + +healthcare. + +He called to scientists +and engineers. + +And last night the American +people said yes, we like that + +vision, and they elected +him president. + +So we have been called, you +have been called, he has + +reached out to students and +said, students of science and + +engineering, you need +to contribute. + +And it's been a while since +any president has really + +called to action, scientists +and engineers. + +And last time that happened, +a man went on the moon. + +So let's see what we +can do this time. + +The next challenge is clean +energy, healthcare. + +It's going to be really +important for sciences and + +engineers to get involved, +and at the core an energy + +technologies, and at the core +of medicine is chemistry. + +So you are in the right +place right now. + +You are going to be the +generation that needs to solve + +these problems, because if you +don't solve the energy problem + +and don't come up with clean +alternatives, there isn't + +going to be much of a planet +left for another generation to + +try to solve those problems. So +it's going to be your job + +and your job is starting right +now with the education that + +you can get at MIT. + +So, it's actually somewhat +interesting that today, the + +day after this election, we are +going to talk about one of + +the units that students in this +class have had the most + +difficulty with over the years, +acid based titrations. + +This has been the undoing of +some chemistry individuals. + +It has been the undoing of some +grades of A. It has been + +the undoing, perhaps, of some +interest in chemistry. + +But I would like to say today, +at this moment, it will not be + +your undoing, it will +be your triumph. + +Every year I challenge students +to do the best job on + +acid based titration ever, and +people have been doing well. + +This might be the last time +I teach in the fall. + +You have actually had the +highest grades so far in this + +class, in the history of the +class that I know of, and so + +this is the challenge. + +So right after this election, +your challenge is to conquer + +chemistry starting one acid +and one base at a time. + +So, ready to do some acid +based titrations? + +Who are the naysayers +in this crowd? + +Just a few people up there. + +All right. + +I have to tell you that what +I'm going to tell you about + +acid based titrations will seem +like it makes pretty good + +sense as I'm saying it. + +But often, people inform me that +when they actually go to + +work the problems on the test, +it's a little less clear on + +what they're supposed +to be doing. + +So the key to acid based +titrations is really to work + +problems. And so we have, for +your benefit, assigned + +problems for the problem-set +due Friday. + +And so after today, you should +be set to do all of the + +problems on the problem-set. + +And in terms of acid based +titration, you will need a lot + +of this knowledge again +in organic chemistry, + +biochemistry, if you go +to medical school -- + +I used to TA medical students, +they didn't + +know how to do this. + +And I said "Who taught you +freshmen chemistry?" So it's + +good to learn to this now here +today, work problems, take the + +next test, and guaranteed it'll +be on the final again. + +So you'll learn it now, you'll +get lots of points, both on + +the final and the third exam. + +All right, so acid based +titrations, they're not that + +hard, but there are not a lot +of equations to use, and I + +think that people in chemistry +are used to what + +equation do I use. + +No, it's really about thinking +about what's going on in the + +problem, and as the problem +proceeds, as more, say, strong + +base is added, the +problem changes. + +So it's figuring out where you +are in the titration and + +knowing what sort of +steps to apply. + +So here are some titration +curves, and one thing you may + +be asked to do is draw a +titration curve, so you should + +be familiar with what +they look like. + +So we talked last time about +strong acids and strong bases. + +So if you have a strong base, +you're going to have a basic p + +h, and then as you add the +strong acid, you will go to + +the equivalence point, +equivalence point when you've + +added the same amount of moles +of acid as there is base or + +base as there is acid, equal +number of moles. + +And when you mix a strong acid +in a strong base, you form a + +salt, and the salt is neutral in +p h, because the conjugate + +of a strong acid or a strong +base, is ineffectual, it + +doesn't affect the p +h, it's neutral. + +So we have p h 7, and then you +continue to add, in this case, + +a more strong acid, and +the p h goes down. + +So for the other titration it's +pretty much the same, + +except you start at acidic p +h's, go up to neutral p h, and + +then go basic. + +So we talked about these last +time and we worked a couple of + +problems, but now we're going to +move into the slightly more + +difficult type of problem, which +has to do with when you + +have a weak acid or a weak +base being titrated. + +So let's look at the difference +of the curve to + +start off with. + +So here we have the strong acid +and the strong base, and + +here we have a weak acid +and a strong base. + +One thing you may notice right +off is that the equivalence + +point has a different p h. + +So, a strong acid and strong +base again, mix, you form a + +salt that's neutral, p h 7. + +But if you're titrating a weak +acid in a strong base, the + +conjugate of the strong base +will be ineffective, but the + +conjugate of the weak acid +will act as a base. + +So the p h then, at the +equivalence point, when you've + +added equal number of moles of +your strong base as you had + +weak acid, then you'll have the +conjugate base around, and + +the p h will be greater +than 7. + +So in working the problems, if +you get an answer with this + +type of titration problem that's +different than that for + +p h at the equivalence point, +you're going to know that you + +did something wrong, +you need to go back + +and check your math. + +Another big difference has to +do with the curve shape down + +here, and so you notice +a difference over + +here than over there. + +And in a titration that involves +a weak acid in a + +strong base, you have a part of +the curve that's known as a + +buffering region, and the p +h is fairly flat in this + +buffering region as +shown down here. + +So that's in contrast, there's +no such buffering + +region on this side. + +So here the p h will go +up, it'll level off, + +and then go up again. + +And this, for some of you, is +probably the frustration in + +doing acid based titrations in +lab, because you're adding and + +nothing's happening and +nothing's happening and + +nothing's happening, and you're +in this region, then + +all of a sudden you add +just a little more + +and you're up here. + +So notice how steep +that is over here. + +So sometimes when you're in the +buffering region, it seems + +like you're never going to reach +the end of the titration + +and then it'll happen +all too quickly. + +So buffering region, remember a +buffer is something that has + +a conjugate, weak acid and weak +base pair, and then in a + +buffering region, the p h +pretty much stays fairly + +constant in that region. + +It acts as a buffer, +neutralizing the p h, + +maintaining the p h by being a +source or sink of protons, and + +so here the p h then is staying +constant in that + +buffering region. + +So those are some of +the differences + +between the type of curves. + +Another point that I will +mention or term I will mention + +that has to do with weak acid in +strong base or a weak base + +in strong acid is this 1/2 +equivalence point concept. + +So 1/2 equivalence point you've +added 1/2 of the amount + +of strong base that you need +to get to the equivalence + +point, and that's right +in the middle of + +that buffering region. + +So that's another point where +you'll be asked to + +calculate the p h. + +So now let's look at different +points in a titration. + +So, first let's walk through +and just think + +about what is happening. + +So when we start in this +titration of a weak acid in a + +strong base, before we've added +any of the strong base, + +all we have is a weak acid. + +So it is a weak acid in +water type problem. + +And so here I've drawn our acid, +and the acid has its + +proton, which is going +to give up when you + +start doing the titration. + +So that's what we have +at zero volume. + +Then we start adding our strong +base, and the strong + +base is going to react with +the acid, one-to-one + +stoichiometry, it's +a strong base. + +It'll pull off protons off the +same number of moles of the + +strong acid as the number of +moles of the strong base that + +were added. + +And so then, you'll start to +have a mixture of your + +conjugates, your weak acid +and your conjugate base. + +So the base is a minus here. + +And so if you have a mixture +of a weak acid in its + +conjugate base, that's a buffer, +and so you'll move in + +to the buffering region here. + +So that's at any volume that is +greater than zero and less + +than the equivalence point +is going to be + +around in that region. + +Then we have a special category +of the buffering + +region, which is when you've +added the volume to get to the + +1/2 equivalence point. + +And when you've done that, you +will have converted 1/2 of the + +weak acid it its conjugate base, +so you'll have equal + +number of moles of your weak +acid as moles of the + +conjugate base -- + +1/2 has been converted. + +And so that's a special +category right there. + +Then you get to the +equivalence point. + +At the equivalence point, you've +added the same number + +of moles of strong base as the +number of moles of weak acid + +you have, so you've converted +all of your weak acid to it's + +conjugate base. + +So all you have is conjugate +base now, and so that's + +controlling the p h, so the p +h should be greater than 7. + +So that's a weak base +in water problem. + +And if you keep going, then +you're going to end up with a + +strong base in water problem. + +The weak base will still be +around, but it will be + +negligibly affecting the p h +compared to the fact that + +you're dumping strong acid +into your titration. + +And so that's this part +of the curve. + +So you see that in one type +of problem, one titration + +problem, you actually have a +lot of sub problems, or sub + +types of problems, you'll have +weak acid buffer, special + +category of buffer, a conjugate +base or a salt + +issue, and then a strong base. + +And this is one of the things +that people have trouble with + +in the titrations, because we +may not ask you to do all the + +points, we may just sort of +jump in somewhere, and say + +okay, what is the p h at the +equivalenced point, and you + +need to think about what's +happened to get to the + +equivalence point. + +Or we may jump in and ask you +about a region that would be + +in the buffering region, and you +have to remember that at + +that point you should have some +of the weak acid and also + +some of the conjugate +bases being formed. + +So, it seems like there are a +lot of different things, but + +there are only five types of +problems. But in a titration + +curve, you run into a lot of +those different types at + +different points +in the problem. + +So now let's go the other +direction and consider + +titration of a weak base +with a strong acid. + +So here's what that curve +would look like. + +You're going to start basic, +of course, because you're + +starting with a weak base, +you haven't added + +any strong acid yet. + +As you add strong acid, +the p h will decrease. + +Because it is a weak base, you +will be forming some of its + +conjugate as you add the strong +acid, and so you'll go + +through a buffering region again +where the curve would be + +flat, where the p h will be +pretty much the same for + +region of time. + +Then the curve will drop again +and you'll get to the + +equivalence point. + +At the equivalence point, you've +added the same amount + +of moles of strong acid as you +had weak base, so all of your + +weak base is converted to its +conjugate acid, and so you + +should be acidic at the +equivalence point, and then + +the curve goes down. + +So again, we can think +about this in + +terms of what is happening. + +In the beginning it's just a +weak base in water problem, + +but as you add strong acid, +you were pronating some of + +your base and forming its +conjugate acid here, and + +you're in the going to be +in the buffering region. + +Then at the 1/2 equivalence +point, you've added enough + +moles of strong acid to convert +1/2 of the weak base + +to its conjugate, so those are +going to be equal to each + +other -- the number of moles +of the weak base and the + +number of moles of its +conjugate acid. + +At the equivalence point, you've +converted all of the + +weak base you started with to +its conjugate acid, so it'll + +be a weak acid in water problem, +and then at the end + +it's strong acid. + +So the trick is to recognizing +what type of problem you're + +being asked to do, and a lot +of times if people get a + +question and they just write +down OK, at this point in the + +titration curve, it's +going to be a weak + +base in water problem. + +And just writing that down, most +of the time if you get + +that far, you do the rest of +the problem correctly. + +So just identifying the type, +there are only 5, of problems + +gets you a long way to getting +the right answer. + +So let's do an example. + +We're going to titrate a weak +acid with a strong base. + +We have 25 mils of 0.1 molar +acid with 0.15 moles of a + +strong base, n a o h, we're +given the k a for the acid. + +First we start with 0 mils +of the strong base added. + +So what type of problem +is this? + +It's a weak acid problem. + +So we know how to write the +equation for a weak acid or + +for an acid in water. + +We have the acid in water going +to hydronium ions and a + +conjugate base. + +So weak acid. + +For weak acid, we're going to +use our k a, and we're going + +to set up our equilibrium +expression. + +So here we have 0.1 +molar of our acid. + +We're going to have some +of that go away in the + +equilibrium, forming hydronium +ion and some conjugate base, + +and so we know we have +expressions for the + +concentrations at equilibrium. + +And we can use our k a, k a +for acid, it's a weak acid + +problem, and we can look at +products over reactants. + +So, see, now we're doing a +titration problem, but you + +already know how to do this +problem because we've seen a + +weak acid in water +problem before. + +So we have x squared over +0.10 minus x here. + +We can assume x is small, and +get rid of this minus x, and + +then later go back and check +it, so that just makes the + +math a little bit easier. + +And we can solve for x and then +we can check -- we can + +take this value, 0.00421 over +0.1 and see whether that's + +less than 5%, it's +close but it is. + +So that assumption is OK. + +If it wasn't, what would +we have to do? + +Quadratic equation. + +All right, so now, here's +a sig fig question. + +Tell me how many sig figs +this p h actually has. + +OK, 10 seconds. + +So, in the first part of the +problem we had a concentration + +that had 2 significant figures, +the 0.10 molar. + +Sometimes later, people have +extra significant figures that + +they're carrying along, but we +had those 2, and so we're + +going to have 2 after the +decimal point then in the + +answer of the p h. + +So again, the number of +significant figures that are + +limiting are going +to be the number + +after the decimal point. + +All right, so we have one +p h value, and now we're + +going to move on. + +So let me just put our +one p h value down. + +We have volume of strong base, +and p h over here, and we're + +starting here with +zero moles added. + +We have a p h of 2 . + +38. + +It's a weak acid, so it should +be an acidic p h, which it is. + +All right, so now let's move +into the titration problem, + +and now 5 . + +0 mils of the strong base have +been added, and we need to + +find what the p h is now. + +So it's a strong base, so it's +going to react almost + +completely, that's +our assumption. + +If it's strong, it +goes completely. + +And so, the number of moles of +the strong base that we add + +will convert all of the same +number of moles of our acid + +over to its conjugate. + +So we can just do a +subtraction then. + +So first, we need to know +the initial moles of the + +acid that we had. + +We had 25 mils, 0.10 molar. + +We calculate the number of moles +for the hydroxide added, + +we added 5 mils, it was 0.15 +molar, and so we can calculate + +the number of moles of the +strong base that were added. + +So the strong base will react +completely with the same + +number of moles of +the weak acid. + +And we're going to do then -- we +have the moles of the weak + +acid here, minus the number of +moles of the strong base we've + +added, and so we're +going to have 1 . + +75 times 10 to the minus 3 moles +of the weak acid left. + +So, then how many moles of the +conjugate base will be formed + +by this reaction? + +What do you think? + +Same number. + +So 0.75 times 10 +to the minus 3. + +So always remember that in +these titration problems, + +nothing has been added yet, +you're at zero mils added. + +Some amount of some subtractions +are going to have + +to occur because something +has happened. + +You've converted something, +things are different than when + +you started. + +All right, so now we have weak +acid and we have moles of its + +conjugate, what type +of problem is this? + +If you have a weak acid and +its conjugate base -- + +buffer, right. + +So we're going to do a buffer +problem and we need to know + +the molarity first. So we have +moles over volume -- again, + +the volume, you had 25 mils to +begin with, you added 5 more. + +So you have to have the total +volume 30 mils, and we can + +calculate then the +concentrations of both. + +Now we can set up our +equilibrium table, and this + +looks like a buffer problem +because it is, and by looking + +like a buffer problem you +something over here, you have + +your weak acid over here, but +you have something over here + +now, it's not zero now, +we're starting with + +some conjugate base. + +So we have 0.0583 minus x on one +side, and we 0.025 molar + +plus x on the other side. + +We can use k a again. + +This is set up as an acid in +water going to hydronium ions + +and conjugate base, so we can +use our k a, set things up, + +and we can always say let's +see if x is small, make an + +assumption, check it later. + +That'll simplify the math. + +So we get rid of the plus +x and the minus x. + +Again, we're saying that if +x is small, the initial + +concentrations are going to be +more or less the same as the + +concentrations after the +equilibration occurs. + +And we can calculate 4 . + +13 times 10 to the minus +4, as x, that is a + +pretty small number. + +And we have to check it, and +yup, it's small enough, it's + +under 5%, so that's OK. + +So now we can plug this in. + +X is our hydronium ion +concentration minus log of the + +hydronium ion concentration +is p h, and we can + +calculate p h to 3 . + +38 -- again, we're limited by +two significant figures in the + +concentration. + +So now we've added 5 mils down +here, and our p h has gone up + +a little bit, it's now at 3 . + +38 over here. + +There's another option +for a buffer problem. + +What's the one equation +in this unit? + +Our friend Henderson +Hasselbalch. + +And yes, you can use that here +too, assuming that you check + +the assumption and it's OK. + +Most people will prefer +to do this + +because it is a bit easier. + +So, you weren't given, though, +the p k a in this problem, you + +were given the k a, so pretty +easy to calculate -- minus log + +of the k a is the p k a. + +So you can calculate +that, put that in. + +You have your concentrations +and it should be + +concentrations, but you may +notice that if you actually + +had moles the volume +would cancel here. + +So here are the concentrations, +but with the + +same volume, the volume +term does cancel. + +It makes this a little faster +and it gives the same answer, + +which is great. + +To use Henderson Hasselbalch you +also need the 5% rule to + +be true, because Henderson +Hasselbalch is + +assuming that x is small. + +It's assuming that the initial +concentrations and the + +concentrations after +equilibrium + +are about the same. + +So we can check the +assumption. + +We can back-calculate the +hydronium ion concentration, + +which would be x, and see if +it's small, we already know it + +is, so it's OK. + +So there are 2 options for +buffer problems, but do not + +use the Henderson Hasselbalch +equation when it isn't in the + +buffering region, it +doesn't hold then. + +So again, you check the +assumption, and if + +it's OK, it's fine. + +If not, you need to use option +one and you need to use the + +quadratic equation. + +All right, so buffering +region. + +Now we're at the special kind +of problem in the buffering + +region, the 1/2 equivalence +point. + +So here you've added 1/2 the +number of moles of the strong + +base to convert 1/2 +the moles of the + +weak acid to its conjugate. + +So at this point, the +concentration of h a equals + +the concentration of a minus +-- equal number of moles in + +the same volume, those +are equal. + +You can use Henderson +Hasselbalch here, and find + +that if they're equal, you're +talking about minus log of 1, + +so the p h is going to +equal the p k a. + +And you're done with this +type of problem. + +I have been known to put 1/2 +equivalence problems on an + +exam, because exams are often +long, you have only 50 + +minutes, there's lots of +different type of problems, + +and this problem should +not take you a + +long amount of time. + +You do not have to prove to +me that this is true. + +All you need to remember, 1/2 +equivalence point, p h equals + +p k a, and if you calculate +the p k a, you're done. + +So this is a short +type of problem. + +If you remember the definition +of 1/2 equivalence point, it's + +easy to do. + +So now we have another +number, so 3 . + +75, and we're working +on our curve. + +Now let's move to the +equivalence point. + +At the equivalence point, you've +added the same number + +of moles of your strong base +as you had weak acid. + +So you've converted all of +your weak acid to its + +conjugate base. + +So the p h should be +greater than 7. + +Now all you have is conjugate +base, that's basic, p h should + +be greater than 7. + +So when you are doing this +titration, you have your weak + +acid and your strong base. + +You're going to be forming a +salt here, and a salt problem, + +you can tell me about salts. + +And so, just remind me, what +does the n a plus contribute + +to the p h here. + +It's going to be neutral. + +And what about this +guy down here? + +Yeah, so it's going +to be basic. + +So, the sodium, anything group +1, group 2, no effect on p h, + +they're neutral. + +But if you have a conjugate base +of a weak acid, that's + +going to be basic. + +Salt problems, really just +part of what you + +already know about. + +So always check your work. + +If your p h doesn't make sense +from what you know, you might + +have made a math mistake. + +So let's calculate the actual p +h at the equivalence point. + +We know that it should +be basic, but what + +is it going to be? + +So first, we need to know how +much of the strong base we had + +to add, because we need to +know about all the moles. + +So how much of this did +we need to add. + +So we needed to add enough of +the strong base that you + +converted all of the +moles of the + +weak acid to its conjugate. + +So we had 2 . + +5 times 10 to the minus 3 +moles of our weak acid. + +So that's all going to be +converted to the moles of the + +conjugate base, and so that's +going to be equal to the + +number of moles we +needed to do it. + +So we needed 2 . + +5 times 10 to the minus 3 moles +of our strong base to do + +that complete conversion. + +We know the concentration +of the base was 0.15 . + +So we would have needed 1 . + +67 times 10 to the minus 2 +liters of this concentration + +added to reach the equivalence +point. + +So then the total volume that +we're going to have at the + +equivalence point is the 25 +mils that we had to begin + +with, plus this 16 . + +7 mils to make this final, +total volume. + +And remember, you always need +to think, what is the total + +volume, how much has been added +to get to this point in + +the titration curve. + +Then we can calculate molarity, +so we know how many + +moles of conjugate base have +been formed, and we know the + +new volume, so we can calculate +the concentration of + +the conjugate base. + +So now, you can help me +solve this problem. + +Set up an equation for +me to solve it. + +Let's take 10 seconds. + +That's the best score +we've had today. + +Yup. + +So now we're talking about +a conjugate base. + +So we have converted all of the +weak acid to the conjugate + +base, and so it's a weak base +in water problem, so we're + +going to talk about a k b. + +If you were only given the k a +for this problem, how would + +you find k b -- what +interconnects k a and k b? + +K w, right. + +So you can calculate, here it's +given to you, but you + +could calculate it if you had +a calculator, and you would + +find that this is true. + +Now it's a weak base +in water problem. + +We're not in the buffering +region anymore. + +We've converted all of our weak +acid to the conjugate. + +So it's a weak base +in water problem. + +So we have x squared, 0.06, that +was the concentration we + +calculated, minus x. + +So again, think about what +type of problem it is. + +So again, weak base in water +problem -- x squared + +over 0.06 minus x. + +And we can assume that x is +small, and calculate a value + +for x, which is 0.83 times 10 to +the minus 6, and then we're + +going to calculate p o h, +because now x is the hydroxide + +ion concentration. + +Because in a weak base in water +problem, here in this + +type of problem, the base, and +here is your acid -- the + +conjugate of this acid is the +base, hydroxide, and the + +conjugate of this weak base is +its conjugate acid over here, + +so now when we are solving for +x, we're solving for hydroxide + +ion in concentration, so we're +calculating a p o h, which + +then we can calculate +a p h from. + +So we can take 14 minus 5 . + +74 and get our value. + +And it's bigger than neutral, +it's 8, it's basic, and that + +makes sense, it is a weak +base in water problem. + +So, let's see, it's 8 . + +26, so now we're up here in our +curve, and we're at 8 . + +26, and that's going to be +greater than 7 for this type + +of problem. + +So that makes sense, +it's good. + +Greater than 7 is what +we want to see. + +So now, you've gone too far -- +you've passed the equivalence + +point, and you keep adding +your strong base in. + +Now you still have some of the +weak conjugate base around. + +So you still have this around, +but you only have 1 . + +83 times 10 to the minus +6 molar of it. + +So very little amount +-- x is small. + +So your p h is going to be +dictated by the amount of + +extra strong base +you're adding. + +So this is similar, then, to a +strong acid or strong base in + +water problem. + +So if you're 5 mils past the +equivalence point, 5 mils + +times your concentration of +a strong base, so you + +have extra, 7 . + +5 times 10 to the minus +4 moles extra. + +So then you need to calculate +a concentration of that, and + +so you remember the whole volume +-- you're 5 mils past, + +you had 25 miles to start with, +and you had to add 16 . + +7 mils to get to the +equivalence point. + +And you have, that's your +total volume, you get a + +concentration, that's your +concentration of hydroxide, it + +reacts completely, you don't +have to do any equilibrium + +table here. + +It's going complete, +it's a strong base. + +You could try adding that value +of your other weak base + +to this, but remember, that's +times 10 to the minus 6, so + +it's not going to +be significant + +with significant figures. + +So you can just use this value +-- plug it in to p o h, + +calculate it, and then +calculate p h. + +And so now we're somewhere +up here at p h 12 . + +21, 5 mils past. +And there we've + +worked a titration problem. + +So let's review what we saw. + +In the beginning, zero mils of +the strong base, we have a + +weak acid in water problem. + +We moved into the buffering +region where we had our weak + +acid and the conjugate base +of that weak acid. + +At the equivalence point, we've +converted all of the + +weak acid to the conjugate +base, so + +it's a weak base problem. + +And then beyond the equivalence +point, it's a + +strong base problem. + +That's what we've just worked. + +So, we can check these +all off now. + +You know how to do all of these +types of problems. And + +there are not that many, you +just need to figure out where + +to apply what. + +And if you can do that, you're +all set, this unit will be + +easy for you, and you can go +through and make me very happy + +on the exam. + +There's nothing -- well, there +are few things in life as + +beautiful to me as a perfectly +worked titration problem. + +It really, it brings me joy, and +I've had people write on + +the exam sometimes, "I hope +that my solution to this + +brings you joy." And I will +often write, "Yes, it does," + +and put a smiley face. + +Because it really is nice to see +these beautifully worked. + +I know, I'm a little nerdy and +geeky, but after yesterday, + +being smart and a nerd and +a geek is cool again. + +All right, so let me just tell +you where we're going. + +We have five more minutes, and +actually that's perfect, + +because I can get through some +rules in those 5 minutes. + +So let's do 5 minutes +of rules. + +Oxidation reduction doesn't have +a lot of rules, so five + +minutes is actually all +we need to do that. + +Oxidation reduction involves +equilibrium, it involves + +thermodynamics. + +I like it because it's really +important for reactions + +occurring in the body, and acid +bases as well -- p k a's + +are really important to that. + +And so, between acid base and +oxidation reduction, you cover + +the way a lot of enzymes work. + +So let me give you five minutes +of rules, and that + +will serve you well +in this unit. + +Some of these are +pretty simple. + +For free elements, each atom has +an oxidation number of 0, + +so this would be 0. + +So, oxidation number of +0 in a free element. + +For ions that are composed of +one atom, the oxidation number + +is equal to the charge of the +atom, so lithium plus 1 ions + +would have an oxidation +number of plus 1. + +Again, pretty straightforward. + +Group one and group two +make your lives easy. + +They seem to have a lot +of consistent rules. + +Group one metals in the periodic +table have oxidation + +numbers of 1. + +Group two metals have oxidation +numbers of plus 2. + +Aluminum is plus 3 in +all its compounds. + +Pretty simple. + +Now we get to things that are a +little more complicated but + +still useful, oxygen. + +Oxygen is mostly minus 2, but +there are exceptions to that, + +such as in peroxides where it +can have an oxidation number + +of minus 1, and if it's with +a group one metal, it + +can be minus 1. + +Remember, group one, and +actually group two here, + +that's plus 1, always plus 1, +always plus 1, always plus 2, + +and so hydrogen has to +accommodate that. + +So usually plus 1, except when +it's in a binary complex with + +these particular metals that are +in group one or group two. + +Fluorine, almost always minus 1, +or always minus 1 -- other + +halogens, a chloride, bromide, +iodide, also usually + +negatives, but if they're with +oxygen, then it changes. + +So, here is an example. + +And in neutral molecules, +the sum of the oxidation + +numbers must be 0. + +When the molecule has a +charge, the sum of the + +oxidation numbers must be +equal to that charge. + +So, let's do a quick example. + +Hydrogen, in this case, +is going to be what? + +Plus 1, so it's not +with a group one, + +group two metal here. + +So what does that leave +for nitrogen? + +And that makes the sum, plus 1, +which is equal to the sum + +of that molecule, +so that works. + +So we might not have known +nitrogen, but we can figure it + +out if we know the rules for +hydrogen and we know what it + +all has to equal up to. + +And so, this unit is sometimes +a relief after oxidation + +reduction, because it's all +about simple adding and + +subtracting, it's not so bad. + +OK, oxidation numbers do not +have to be integers. + +Example here, you have +superoxide, what would its + +oxidation number be? + +Minus 1/2. + +And those are the rules, and +then on Friday, we'll come + +back and we'll look +at some examples. \ No newline at end of file diff --git a/ILiokEbMqr4.txt b/ILiokEbMqr4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a773f8d90538034153aa98e8021eb609c0916a65 --- /dev/null +++ b/ILiokEbMqr4.txt @@ -0,0 +1,299 @@ +align:start position:0% + +the best part about today I would say is + + align:start position:0% +the best part about today I would say is + + + align:start position:0% +the best part about today I would say is +how smoothly everything went with the + + align:start position:0% +how smoothly everything went with the + + + align:start position:0% +how smoothly everything went with the +6th graders I just I I was stressed + + align:start position:0% +6th graders I just I I was stressed + + + align:start position:0% +6th graders I just I I was stressed +about they actually had like pretty + + align:start position:0% +about they actually had like pretty + + + align:start position:0% +about they actually had like pretty +constructive feedback so I I'm happy + + align:start position:0% +constructive feedback so I I'm happy + + + align:start position:0% +constructive feedback so I I'm happy +about how that would the worst part + + align:start position:0% +about how that would the worst part + + + align:start position:0% +about how that would the worst part +about today i feel like people feel lost + + align:start position:0% +about today i feel like people feel lost + + + align:start position:0% +about today i feel like people feel lost +they kind of had a deer in the + + align:start position:0% +they kind of had a deer in the + + + align:start position:0% +they kind of had a deer in the +headlights look on their faces sometimes + + align:start position:0% +headlights look on their faces sometimes + + + align:start position:0% +headlights look on their faces sometimes +because we're really talking at a more + + align:start position:0% +because we're really talking at a more + + + align:start position:0% +because we're really talking at a more +abstract conceptual level and they + + align:start position:0% +abstract conceptual level and they + + + align:start position:0% +abstract conceptual level and they +haven't had a chance to really put stuff + + align:start position:0% +haven't had a chance to really put stuff + + + align:start position:0% +haven't had a chance to really put stuff +into practice yet and i know that i'll + + align:start position:0% +into practice yet and i know that i'll + + + align:start position:0% +into practice yet and i know that i'll +help or that'll change tonight and I + + align:start position:0% +help or that'll change tonight and I + + + align:start position:0% +help or that'll change tonight and I +know that the workshops and stuff will + + align:start position:0% +know that the workshops and stuff will + + + align:start position:0% +know that the workshops and stuff will +help tomorrow and the rest of this week + + align:start position:0% +help tomorrow and the rest of this week + + + align:start position:0% +help tomorrow and the rest of this week +but at some point I just felt like i was + + align:start position:0% +but at some point I just felt like i was + + + align:start position:0% +but at some point I just felt like i was +saying words that weren't super useful + + align:start position:0% +saying words that weren't super useful + + + align:start position:0% +saying words that weren't super useful +to them I couldn't stop i should have + + align:start position:0% +to them I couldn't stop i should have + + + align:start position:0% +to them I couldn't stop i should have +just shut up but i did reconfiguring our + + align:start position:0% +just shut up but i did reconfiguring our + + + align:start position:0% +just shut up but i did reconfiguring our +furniture arrangement to this u-shape + + align:start position:0% +furniture arrangement to this u-shape + + + align:start position:0% +furniture arrangement to this u-shape +definitely made the class feel more + + align:start position:0% +definitely made the class feel more + + + align:start position:0% +definitely made the class feel more +intimate and i think that maybe that + + align:start position:0% +intimate and i think that maybe that + + + align:start position:0% +intimate and i think that maybe that +contributed to them talking a lot more + + align:start position:0% +contributed to them talking a lot more + + + align:start position:0% +contributed to them talking a lot more +compared to yesterday i mean there are a + + align:start position:0% +compared to yesterday i mean there are a + + + align:start position:0% +compared to yesterday i mean there are a +lot of confounding variables with that + + align:start position:0% +lot of confounding variables with that + + + align:start position:0% +lot of confounding variables with that +but they did seem to talk a lot more I + + align:start position:0% +but they did seem to talk a lot more I + + + align:start position:0% +but they did seem to talk a lot more I +could do anything different today maybe + + align:start position:0% +could do anything different today maybe + + + align:start position:0% +could do anything different today maybe +leaving more time for scripting I really + + align:start position:0% +leaving more time for scripting I really + + + align:start position:0% +leaving more time for scripting I really +was going to rely on tomorrow to be the + + align:start position:0% +was going to rely on tomorrow to be the + + + align:start position:0% +was going to rely on tomorrow to be the +big scripting day and I realize now that + + align:start position:0% +big scripting day and I realize now that + + + align:start position:0% +big scripting day and I realize now that +that probably wasn't the greatest idea + + align:start position:0% +that probably wasn't the greatest idea + + + align:start position:0% +that probably wasn't the greatest idea +because people don't know how to script + + align:start position:0% +because people don't know how to script + + + align:start position:0% +because people don't know how to script +and of course they don't because who + + align:start position:0% +and of course they don't because who + + + align:start position:0% +and of course they don't because who +does if you haven't ever done it before + + align:start position:0% +does if you haven't ever done it before + + + align:start position:0% +does if you haven't ever done it before +I'm excited about tomorrow because it's + + align:start position:0% +I'm excited about tomorrow because it's + + + align:start position:0% +I'm excited about tomorrow because it's +a more calm day to my relaxed it's more + + align:start position:0% +a more calm day to my relaxed it's more + + + align:start position:0% +a more calm day to my relaxed it's more +formal \ No newline at end of file diff --git a/IZGnYe7BUms.txt b/IZGnYe7BUms.txt new file mode 100644 index 0000000000000000000000000000000000000000..4debfd9f4fdaba1fb6fa76c58b22905204907958 --- /dev/null +++ b/IZGnYe7BUms.txt @@ -0,0 +1,1699 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu previously we've shown + + align:start position:0% +ocw.mit.edu previously we've shown + + + align:start position:0% +ocw.mit.edu previously we've shown +several ways of getting low contrast + + align:start position:0% +several ways of getting low contrast + + + align:start position:0% +several ways of getting low contrast +fringes in a Michaelson 2 Beam + + align:start position:0% +fringes in a Michaelson 2 Beam + + + align:start position:0% +fringes in a Michaelson 2 Beam +interferometer for for example when the + + align:start position:0% +interferometer for for example when the + + + align:start position:0% +interferometer for for example when the +mirrors are shaking you get poor + + align:start position:0% +mirrors are shaking you get poor + + + align:start position:0% +mirrors are shaking you get poor +contrast when when the intensities in + + align:start position:0% +contrast when when the intensities in + + + align:start position:0% +contrast when when the intensities in +the two arms are unequal when we have + + align:start position:0% +the two arms are unequal when we have + + + align:start position:0% +the two arms are unequal when we have +orthogonal polarization between the + + align:start position:0% +orthogonal polarization between the + + + align:start position:0% +orthogonal polarization between the +beams and the two arms of the + + align:start position:0% +beams and the two arms of the + + + align:start position:0% +beams and the two arms of the +interferometer in this demonstration + + align:start position:0% +interferometer in this demonstration + + + align:start position:0% +interferometer in this demonstration +we're going to show another way and + + align:start position:0% +we're going to show another way and + + + align:start position:0% +we're going to show another way and +probably the most common way of getting + + align:start position:0% +probably the most common way of getting + + + align:start position:0% +probably the most common way of getting +low contrast fringes in a two beam + + align:start position:0% +low contrast fringes in a two beam + + + align:start position:0% +low contrast fringes in a two beam +interferometer and here's a + + align:start position:0% +interferometer and here's a + + + align:start position:0% +interferometer and here's a +setup again we have a helium neon laser + + align:start position:0% +setup again we have a helium neon laser + + + align:start position:0% +setup again we have a helium neon laser +here is the beam from the laser being + + align:start position:0% +here is the beam from the laser being + + + align:start position:0% +here is the beam from the laser being +reflected by this mirror into an optical + + align:start position:0% +reflected by this mirror into an optical + + + align:start position:0% +reflected by this mirror into an optical +isolator made up of a quarter wave plate + + align:start position:0% +isolator made up of a quarter wave plate + + + align:start position:0% +isolator made up of a quarter wave plate +and a polarizer to prevent light going + + align:start position:0% +and a polarizer to prevent light going + + + align:start position:0% +and a polarizer to prevent light going +back into the + + align:start position:0% +back into the + + + align:start position:0% +back into the +laser the beam leaving the isolators + + align:start position:0% +laser the beam leaving the isolators + + + align:start position:0% +laser the beam leaving the isolators +here getting reflected by this mirror + + align:start position:0% +here getting reflected by this mirror + + + align:start position:0% +here getting reflected by this mirror +into the interferometer here's one arm + + align:start position:0% +into the interferometer here's one arm + + + align:start position:0% +into the interferometer here's one arm +of the interferometer and here is the + + align:start position:0% +of the interferometer and here is the + + + align:start position:0% +of the interferometer and here is the +other arm of the interferometer and the + + align:start position:0% +other arm of the interferometer and the + + + align:start position:0% +other arm of the interferometer and the +two beams leaving the + + align:start position:0% +two beams leaving the + + + align:start position:0% +two beams leaving the +interferometer will be reflected by this + + align:start position:0% +interferometer will be reflected by this + + + align:start position:0% +interferometer will be reflected by this +mirror into this lens and then from the + + align:start position:0% +mirror into this lens and then from the + + + align:start position:0% +mirror into this lens and then from the +lens onto the screen so now let's look + + align:start position:0% +lens onto the screen so now let's look + + + align:start position:0% +lens onto the screen so now let's look +at the + + align:start position:0% +at the + + + align:start position:0% +at the +screen and uh we see that we have + + align:start position:0% +screen and uh we see that we have + + + align:start position:0% +screen and uh we see that we have +fringes and the contrast in the fringes + + align:start position:0% +fringes and the contrast in the fringes + + + align:start position:0% +fringes and the contrast in the fringes +look pretty good you can see I can + + align:start position:0% +look pretty good you can see I can + + + align:start position:0% +look pretty good you can see I can +adjust the alignment of one of the arms + + align:start position:0% +adjust the alignment of one of the arms + + + align:start position:0% +adjust the alignment of one of the arms +is what I'm doing right now to separate + + align:start position:0% +is what I'm doing right now to separate + + + align:start position:0% +is what I'm doing right now to separate +the spots and bring them back together + + align:start position:0% +the spots and bring them back together + + + align:start position:0% +the spots and bring them back together +again and then when I take my hand away + + align:start position:0% +again and then when I take my hand away + + + align:start position:0% +again and then when I take my hand away +you can see I have pretty good contrast + + align:start position:0% +you can see I have pretty good contrast + + + align:start position:0% +you can see I have pretty good contrast +in the fringes you also notice that in + + align:start position:0% +in the fringes you also notice that in + + + align:start position:0% +in the fringes you also notice that in +this Arrangement the two arms of the + + align:start position:0% +this Arrangement the two arms of the + + + align:start position:0% +this Arrangement the two arms of the +interferometer are equal and we've + + align:start position:0% +interferometer are equal and we've + + + align:start position:0% +interferometer are equal and we've +indicated this by this zero over here so + + align:start position:0% +indicated this by this zero over here so + + + align:start position:0% +indicated this by this zero over here so +the zero indicates that this arm is + + align:start position:0% +the zero indicates that this arm is + + + align:start position:0% +the zero indicates that this arm is +equal to this + + align:start position:0% +equal to this + + + align:start position:0% +equal to this +arm now as I move one arm that let's say + + align:start position:0% +arm now as I move one arm that let's say + + + align:start position:0% +arm now as I move one arm that let's say +by a few + + align:start position:0% +by a few + + + align:start position:0% +by a few +centim and also you want to notice that + + align:start position:0% +centim and also you want to notice that + + + align:start position:0% +centim and also you want to notice that +the scale here is in centimeters this is + + align:start position:0% +the scale here is in centimeters this is + + + align:start position:0% +the scale here is in centimeters this is +10 30 50 and and so on so let's say + + align:start position:0% +10 30 50 and and so on so let's say + + + align:start position:0% +10 30 50 and and so on so let's say +around 5 cm let's look at the Fringe + + align:start position:0% +around 5 cm let's look at the Fringe + + + align:start position:0% +around 5 cm let's look at the Fringe +contrast let me + + align:start position:0% + + + + align:start position:0% + +again look at the fringes and you can + + align:start position:0% +again look at the fringes and you can + + + align:start position:0% +again look at the fringes and you can +see that + + align:start position:0% +see that + + + align:start position:0% +see that +indeed the contrast is is a little less + + align:start position:0% +indeed the contrast is is a little less + + + align:start position:0% +indeed the contrast is is a little less +than what it was when we had equal path + + align:start position:0% +than what it was when we had equal path + + + align:start position:0% +than what it was when we had equal path +length let me go a little bit more let's + + align:start position:0% +length let me go a little bit more let's + + + align:start position:0% +length let me go a little bit more let's +say around 10 cm or so again let me + + align:start position:0% +say around 10 cm or so again let me + + + align:start position:0% +say around 10 cm or so again let me +check the alignment + + align:start position:0% +check the alignment + + + align:start position:0% +check the alignment +by adjusting one of the + + align:start position:0% +by adjusting one of the + + + align:start position:0% +by adjusting one of the +mirrors and you can see that now the + + align:start position:0% +mirrors and you can see that now the + + + align:start position:0% +mirrors and you can see that now the +contrast is + + align:start position:0% +contrast is + + + align:start position:0% +contrast is +indeed getting very poor let's go even + + align:start position:0% +indeed getting very poor let's go even + + + align:start position:0% +indeed getting very poor let's go even +further let's say around 30 cm path + + align:start position:0% +further let's say around 30 cm path + + + align:start position:0% +further let's say around 30 cm path +length difference again here the two two + + align:start position:0% +length difference again here the two two + + + align:start position:0% +length difference again here the two two +spots and The Fringe contrast is pretty + + align:start position:0% +spots and The Fringe contrast is pretty + + + align:start position:0% +spots and The Fringe contrast is pretty +bad let's go let's say around 45 cm or + + align:start position:0% +bad let's go let's say around 45 cm or + + + align:start position:0% +bad let's go let's say around 45 cm or +so and check on the alignment of the + + align:start position:0% +so and check on the alignment of the + + + align:start position:0% +so and check on the alignment of the +interferometer and indeed we don't even + + align:start position:0% +interferometer and indeed we don't even + + + align:start position:0% +interferometer and indeed we don't even +see any fringes at all or essentially + + align:start position:0% +see any fringes at all or essentially + + + align:start position:0% +see any fringes at all or essentially +zero contrast but let's go + + align:start position:0% +zero contrast but let's go + + + align:start position:0% +zero contrast but let's go +on let's go on let's say to position + + align:start position:0% +on let's go on let's say to position + + + align:start position:0% +on let's go on let's say to position +around 70 2 + + align:start position:0% +around 70 2 + + + align:start position:0% +around 70 2 +cm and now let me check the + + align:start position:0% +cm and now let me check the + + + align:start position:0% +cm and now let me check the +alignment and we can see + + align:start position:0% +alignment and we can see + + + align:start position:0% +alignment and we can see +that now we can beginning to see some + + align:start position:0% +that now we can beginning to see some + + + align:start position:0% +that now we can beginning to see some +fringes so the contrast is not quite + + align:start position:0% +fringes so the contrast is not quite + + + align:start position:0% +fringes so the contrast is not quite +zero let me go further say around 80 or + + align:start position:0% +zero let me go further say around 80 or + + + align:start position:0% +zero let me go further say around 80 or +so + + align:start position:0% +so + + + align:start position:0% +so +cenm again check on the + + align:start position:0% + + + + align:start position:0% + +alignment little bit + + align:start position:0% +alignment little bit + + + align:start position:0% +alignment little bit +better and we go + + align:start position:0% +better and we go + + + align:start position:0% +better and we go +to 95 + + align:start position:0% +to 95 + + + align:start position:0% +to 95 +or so + + align:start position:0% +or so + + + align:start position:0% +or so +cm and wow we + + align:start position:0% + + + + align:start position:0% + +see we see a very good contrast the + + align:start position:0% +see we see a very good contrast the + + + align:start position:0% +see we see a very good contrast the +contrast has come back in fact it was + + align:start position:0% +contrast has come back in fact it was + + + align:start position:0% +contrast has come back in fact it was +just as good as when we were at equal + + align:start position:0% +just as good as when we were at equal + + + align:start position:0% +just as good as when we were at equal +arms now let's go further than 95 + + align:start position:0% + + + + align:start position:0% + +CM around maybe 105 and let's look again + + align:start position:0% +CM around maybe 105 and let's look again + + + align:start position:0% +CM around maybe 105 and let's look again +at the fridge contrast you can see that + + align:start position:0% +at the fridge contrast you can see that + + + align:start position:0% +at the fridge contrast you can see that +they're getting poorer again let's go + + align:start position:0% +they're getting poorer again let's go + + + align:start position:0% +they're getting poorer again let's go +even + + align:start position:0% +even + + + align:start position:0% +even +further + + align:start position:0% +further + + + align:start position:0% +further +here around 115 CM path length + + align:start position:0% +here around 115 CM path length + + + align:start position:0% +here around 115 CM path length +difference and let me + + align:start position:0% +difference and let me + + + align:start position:0% +difference and let me +readjust and see that the fringes have + + align:start position:0% +readjust and see that the fringes have + + + align:start position:0% +readjust and see that the fringes have +almost + + align:start position:0% +almost + + + align:start position:0% +almost +disappeared so let's go back make sure + + align:start position:0% +disappeared so let's go back make sure + + + align:start position:0% +disappeared so let's go back make sure +that we didn't do anything wrong before + + align:start position:0% +that we didn't do anything wrong before + + + align:start position:0% +that we didn't do anything wrong before +let me go back to where we had good + + align:start position:0% +let me go back to where we had good + + + align:start position:0% +let me go back to where we had good +Fringe contrast around 95 cm and you can + + align:start position:0% +Fringe contrast around 95 cm and you can + + + align:start position:0% +Fringe contrast around 95 cm and you can +see that we have excellent + + align:start position:0% + + + + align:start position:0% + +contrast and we go to say 70 or so + + align:start position:0% +contrast and we go to say 70 or so + + + align:start position:0% +contrast and we go to say 70 or so +CM range contrast is pretty + + align:start position:0% + + + + align:start position:0% + +bad go + + align:start position:0% +bad go + + + align:start position:0% +bad go +to about 45 or so + + align:start position:0% + + + + align:start position:0% + +CM wow that's really awful can't see + + align:start position:0% +CM wow that's really awful can't see + + + align:start position:0% +CM wow that's really awful can't see +anything now just let me take this + + align:start position:0% +anything now just let me take this + + + align:start position:0% +anything now just let me take this +opportunity to show you that in indeed I + + align:start position:0% +opportunity to show you that in indeed I + + + align:start position:0% +opportunity to show you that in indeed I +do have two + + align:start position:0% +do have two + + + align:start position:0% +do have two +beams and I can block in fact one beam + + align:start position:0% +beams and I can block in fact one beam + + + align:start position:0% +beams and I can block in fact one beam +block the other beam indeed I do have + + align:start position:0% +block the other beam indeed I do have + + + align:start position:0% +block the other beam indeed I do have +two beams that are superimposed but yet + + align:start position:0% +two beams that are superimposed but yet + + + align:start position:0% +two beams that are superimposed but yet +absolutely no fringes can be can be + + align:start position:0% + + + + align:start position:0% + +seen and then let me go all the way to + + align:start position:0% +seen and then let me go all the way to + + + align:start position:0% +seen and then let me go all the way to +equal arms to the zero position we + + align:start position:0% +equal arms to the zero position we + + + align:start position:0% +equal arms to the zero position we +adjust the two beams + + align:start position:0% + + + + align:start position:0% + +now we can see we have the good fringes + + align:start position:0% +now we can see we have the good fringes + + + align:start position:0% +now we can see we have the good fringes +again good Fringe contrast but let me go + + align:start position:0% +again good Fringe contrast but let me go + + + align:start position:0% +again good Fringe contrast but let me go +and make this arm here even shorter than + + align:start position:0% +and make this arm here even shorter than + + + align:start position:0% +and make this arm here even shorter than +the other arm let me make it shorter by + + align:start position:0% +the other arm let me make it shorter by + + + align:start position:0% +the other arm let me make it shorter by +about 2 or 3 + + align:start position:0% + + + + align:start position:0% + +cm you see that The Fringe contrast is + + align:start position:0% +cm you see that The Fringe contrast is + + + align:start position:0% +cm you see that The Fringe contrast is +not so wonderful as it was at the zero + + align:start position:0% +not so wonderful as it was at the zero + + + align:start position:0% +not so wonderful as it was at the zero +position let me go to a pathen + + align:start position:0% +position let me go to a pathen + + + align:start position:0% +position let me go to a pathen +difference of minus 10 + + align:start position:0% +difference of minus 10 + + + align:start position:0% +difference of minus 10 +cm and readjust + + align:start position:0% +cm and readjust + + + align:start position:0% +cm and readjust +the other + + align:start position:0% +the other + + + align:start position:0% +the other +mirror and we see that Fringe + + align:start position:0% + + + + align:start position:0% + +contrast is is very + + align:start position:0% + + + + align:start position:0% + +poor so let me go back to the zero + + align:start position:0% + + + + align:start position:0% + +position and look at the + + align:start position:0% +position and look at the + + + align:start position:0% +position and look at the +fringes very + + align:start position:0% +fringes very + + + align:start position:0% +fringes very +good + + align:start position:0% +good + + + align:start position:0% +good +and about 45 cm + + align:start position:0% + + + + align:start position:0% + +and we don't have any + + align:start position:0% +and we don't have any + + + align:start position:0% +and we don't have any +fringes now what could the reason be for + + align:start position:0% +fringes now what could the reason be for + + + align:start position:0% +fringes now what could the reason be for +the fringes + + align:start position:0% +the fringes + + + align:start position:0% +the fringes +disappearing the + + align:start position:0% +disappearing the + + + align:start position:0% +disappearing the +setup is a good setup I think the + + align:start position:0% +setup is a good setup I think the + + + align:start position:0% +setup is a good setup I think the +alignment is pretty good we're paying + + align:start position:0% +alignment is pretty good we're paying + + + align:start position:0% +alignment is pretty good we're paying +careful attention to the + + align:start position:0% +careful attention to the + + + align:start position:0% +careful attention to the +alignment and so what can it be + + align:start position:0% +alignment and so what can it be + + + align:start position:0% +alignment and so what can it be +certainly not it's not in the + + align:start position:0% +certainly not it's not in the + + + align:start position:0% +certainly not it's not in the +interferometer it must be in the in the + + align:start position:0% +interferometer it must be in the in the + + + align:start position:0% +interferometer it must be in the in the +light source now the light source in + + align:start position:0% +light source now the light source in + + + align:start position:0% +light source now the light source in +this case is a helium neon laser and the + + align:start position:0% +this case is a helium neon laser and the + + + align:start position:0% +this case is a helium neon laser and the +separation between the mirrors or the + + align:start position:0% +separation between the mirrors or the + + + align:start position:0% +separation between the mirrors or the +length of the cavity is about 95 + + align:start position:0% +length of the cavity is about 95 + + + align:start position:0% +length of the cavity is about 95 +CM the laser certainly puts out a lot of + + align:start position:0% +CM the laser certainly puts out a lot of + + + align:start position:0% +CM the laser certainly puts out a lot of +light the only thing we don't know about + + align:start position:0% +light the only thing we don't know about + + + align:start position:0% +light the only thing we don't know about +the laser is the spectrum of the light + + align:start position:0% +the laser is the spectrum of the light + + + align:start position:0% +the laser is the spectrum of the light +for example is it single frequency or is + + align:start position:0% +for example is it single frequency or is + + + align:start position:0% +for example is it single frequency or is +it multiple frequency or + + align:start position:0% +it multiple frequency or + + + align:start position:0% +it multiple frequency or +what now what I'm going to do I'm going + + align:start position:0% +what now what I'm going to do I'm going + + + align:start position:0% +what now what I'm going to do I'm going +to set up an arrangement + + align:start position:0% +to set up an arrangement + + + align:start position:0% +to set up an arrangement +that will tell us what the spectrum of + + align:start position:0% +that will tell us what the spectrum of + + + align:start position:0% +that will tell us what the spectrum of +the laser light is and when we come back + + align:start position:0% +the laser light is and when we come back + + + align:start position:0% +the laser light is and when we come back +we'll have it all ready and we can show + + align:start position:0% +we'll have it all ready and we can show + + + align:start position:0% +we'll have it all ready and we can show +you what the spectrum of the laser light + + align:start position:0% +you what the spectrum of the laser light + + + align:start position:0% +you what the spectrum of the laser light +is now we've set up the arrangement for + + align:start position:0% +is now we've set up the arrangement for + + + align:start position:0% +is now we've set up the arrangement for +observing the spectrum of the laser + + align:start position:0% +observing the spectrum of the laser + + + align:start position:0% +observing the spectrum of the laser +light the setup is essentially what we + + align:start position:0% +light the setup is essentially what we + + + align:start position:0% +light the setup is essentially what we +had before here is the interferometer + + align:start position:0% +had before here is the interferometer + + + align:start position:0% +had before here is the interferometer +the two arms of the interferometer and + + align:start position:0% +the two arms of the interferometer and + + + align:start position:0% +the two arms of the interferometer and +the fringes again we can see on the on + + align:start position:0% +the fringes again we can see on the on + + + align:start position:0% +the fringes again we can see on the on +the screen what we've done to observe + + align:start position:0% +the screen what we've done to observe + + + align:start position:0% +the screen what we've done to observe +the spectrum of laser light we've added + + align:start position:0% +the spectrum of laser light we've added + + + align:start position:0% +the spectrum of laser light we've added +this beam splitter over here to reflect + + align:start position:0% +this beam splitter over here to reflect + + + align:start position:0% +this beam splitter over here to reflect +some of the laser light before it enters + + align:start position:0% +some of the laser light before it enters + + + align:start position:0% +some of the laser light before it enters +the interferometer and reflects it into + + align:start position:0% +the interferometer and reflects it into + + + align:start position:0% +the interferometer and reflects it into +this scanning fabric Pro + + align:start position:0% +this scanning fabric Pro + + + align:start position:0% +this scanning fabric Pro +interferometer the output of the + + align:start position:0% +interferometer the output of the + + + align:start position:0% +interferometer the output of the +interferometer is displayed on an + + align:start position:0% +interferometer is displayed on an + + + align:start position:0% +interferometer is displayed on an +oscilloscope over here what we've + + align:start position:0% +oscilloscope over here what we've + + + align:start position:0% +oscilloscope over here what we've +displayed on the face of the soloscope + + align:start position:0% +displayed on the face of the soloscope + + + align:start position:0% +displayed on the face of the soloscope +is one complete free spectral range of + + align:start position:0% +is one complete free spectral range of + + + align:start position:0% +is one complete free spectral range of +the scanning fabric Pro which is about 1 + + align:start position:0% +the scanning fabric Pro which is about 1 + + + align:start position:0% +the scanning fabric Pro which is about 1 +and2 gigz corresponding to the 10 cm + + align:start position:0% +and2 gigz corresponding to the 10 cm + + + align:start position:0% +and2 gigz corresponding to the 10 cm +length of the scanning fabric + + align:start position:0% +length of the scanning fabric + + + align:start position:0% +length of the scanning fabric +Paro now if the laser were indeed + + align:start position:0% +Paro now if the laser were indeed + + + align:start position:0% +Paro now if the laser were indeed +oscillating at one frequency we would + + align:start position:0% +oscillating at one frequency we would + + + align:start position:0% +oscillating at one frequency we would +only see just one one + + align:start position:0% +only see just one one + + + align:start position:0% +only see just one one +Peak but we see about eight or nine + + align:start position:0% +Peak but we see about eight or nine + + + align:start position:0% +Peak but we see about eight or nine +Peaks which means that the laser must be + + align:start position:0% +Peaks which means that the laser must be + + + align:start position:0% +Peaks which means that the laser must be +oscillating at several frequencies + + align:start position:0% + + + + align:start position:0% + +again from the 1 and A2 gigahertz free + + align:start position:0% +again from the 1 and A2 gigahertz free + + + align:start position:0% +again from the 1 and A2 gigahertz free +Spector range we see that the separation + + align:start position:0% +Spector range we see that the separation + + + align:start position:0% +Spector range we see that the separation +between the frequencies of the laser is + + align:start position:0% +between the frequencies of the laser is + + + align:start position:0% +between the frequencies of the laser is +about 160 mahz and this is what we + + align:start position:0% +about 160 mahz and this is what we + + + align:start position:0% +about 160 mahz and this is what we +expect because this corresponds to the + + align:start position:0% +expect because this corresponds to the + + + align:start position:0% +expect because this corresponds to the +95 CM length of the laser + + align:start position:0% + + + + align:start position:0% + +cavity so as you see that the laser is + + align:start position:0% +cavity so as you see that the laser is + + + align:start position:0% +cavity so as you see that the laser is +not a single frequency laser it has many + + align:start position:0% +not a single frequency laser it has many + + + align:start position:0% +not a single frequency laser it has many +any frequencies so maybe the fact that + + align:start position:0% +any frequencies so maybe the fact that + + + align:start position:0% +any frequencies so maybe the fact that +the contrast in the fringes varies so + + align:start position:0% +the contrast in the fringes varies so + + + align:start position:0% +the contrast in the fringes varies so +dramatically with path length difference + + align:start position:0% +dramatically with path length difference + + + align:start position:0% +dramatically with path length difference +may have something to do with the + + align:start position:0% +may have something to do with the + + + align:start position:0% +may have something to do with the +spectrum of the laser + + align:start position:0% +spectrum of the laser + + + align:start position:0% +spectrum of the laser +light and I would like you to think + + align:start position:0% +light and I would like you to think + + + align:start position:0% +light and I would like you to think +about that but in a another + + align:start position:0% +about that but in a another + + + align:start position:0% +about that but in a another +demonstration we're going to bring in a + + align:start position:0% +demonstration we're going to bring in a + + + align:start position:0% +demonstration we're going to bring in a +single frequency laser and indeed we're + + align:start position:0% +single frequency laser and indeed we're + + + align:start position:0% +single frequency laser and indeed we're +going to study this problem very + + align:start position:0% +going to study this problem very + + + align:start position:0% +going to study this problem very +carefully \ No newline at end of file diff --git a/IcyblGdCVr4.txt b/IcyblGdCVr4.txt new file mode 100644 index 0000000000000000000000000000000000000000..208b79ec648a2e206c2f0cbc3e42ec3eb6e985cc --- /dev/null +++ b/IcyblGdCVr4.txt @@ -0,0 +1,7467 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +what I want to do is proceed where we + + align:start position:0% +what I want to do is proceed where we + + + align:start position:0% +what I want to do is proceed where we +left off we're in module seven on + + align:start position:0% +left off we're in module seven on + + + align:start position:0% +left off we're in module seven on +reactive oxygen species I'm introducing + + align:start position:0% +reactive oxygen species I'm introducing + + + align:start position:0% +reactive oxygen species I'm introducing +you to the concept what was the big + + align:start position:0% +you to the concept what was the big + + + align:start position:0% +you to the concept what was the big +picture and at the end of the last + + align:start position:0% +picture and at the end of the last + + + align:start position:0% +picture and at the end of the last +lecture I gave you a few introductory + + align:start position:0% +lecture I gave you a few introductory + + + align:start position:0% +lecture I gave you a few introductory +slides but what we're going to be + + align:start position:0% +slides but what we're going to be + + + align:start position:0% +slides but what we're going to be +focusing on I told you was oxygen can be + + align:start position:0% +focusing on I told you was oxygen can be + + + align:start position:0% +focusing on I told you was oxygen can be +one electron reduced to superoxide + + align:start position:0% +one electron reduced to superoxide + + + align:start position:0% +one electron reduced to superoxide +superoxide can pick up another electron + + align:start position:0% +superoxide can pick up another electron + + + align:start position:0% +superoxide can pick up another electron +they should have a couple protons here + + align:start position:0% +they should have a couple protons here + + + align:start position:0% +they should have a couple protons here +to form hydrogen peroxide so these is + + align:start position:0% +to form hydrogen peroxide so these is + + + align:start position:0% +to form hydrogen peroxide so these is +two of the species we'll be looking at + + align:start position:0% +two of the species we'll be looking at + + + align:start position:0% +two of the species we'll be looking at +if you have iron two around so this goes + + align:start position:0% +if you have iron two around so this goes + + + align:start position:0% +if you have iron two around so this goes +back to the connection to iron + + align:start position:0% +back to the connection to iron + + + align:start position:0% +back to the connection to iron +homeostasis that we talked about in + + align:start position:0% +homeostasis that we talked about in + + + align:start position:0% +homeostasis that we talked about in +module six this is called fentons + + align:start position:0% +module six this is called fentons + + + align:start position:0% +module six this is called fentons +chemistry and you produce hydroxide + + align:start position:0% +chemistry and you produce hydroxide + + + align:start position:0% +chemistry and you produce hydroxide +radicals so that's the third reactive + + align:start position:0% +radicals so that's the third reactive + + + align:start position:0% +radicals so that's the third reactive +species and hydrogen peroxide in the + + align:start position:0% +species and hydrogen peroxide in the + + + align:start position:0% +species and hydrogen peroxide in the +presence of chloride with my low + + align:start position:0% +presence of chloride with my low + + + align:start position:0% +presence of chloride with my low +peroxidase can form hypochlorous acid + + align:start position:0% +peroxidase can form hypochlorous acid + + + align:start position:0% +peroxidase can form hypochlorous acid +which then can chlorinate amino acids or + + align:start position:0% +which then can chlorinate amino acids or + + + align:start position:0% +which then can chlorinate amino acids or +sugars or a lot of other things so you + + align:start position:0% +sugars or a lot of other things so you + + + align:start position:0% +sugars or a lot of other things so you +get rampant chlorination inside the + + align:start position:0% +get rampant chlorination inside the + + + align:start position:0% +get rampant chlorination inside the +cells so these also this cartoon also + + align:start position:0% +cells so these also this cartoon also + + + align:start position:0% +cells so these also this cartoon also +has reactive nitrogen species we're only + + align:start position:0% +has reactive nitrogen species we're only + + + align:start position:0% +has reactive nitrogen species we're only +focusing on the reactive oxygen species + + align:start position:0% +focusing on the reactive oxygen species + + + align:start position:0% +focusing on the reactive oxygen species +okay so that's what we're going and so + + align:start position:0% +okay so that's what we're going and so + + + align:start position:0% +okay so that's what we're going and so +at the end at the beginning of the + + align:start position:0% +at the end at the beginning of the + + + align:start position:0% +at the end at the beginning of the +lecture um I wanted to introduce you and + + align:start position:0% +lecture um I wanted to introduce you and + + + align:start position:0% +lecture um I wanted to introduce you and +I did give you an overview of where we + + align:start position:0% +I did give you an overview of where we + + + align:start position:0% +I did give you an overview of where we +were going we were going to look at what + + align:start position:0% +were going we were going to look at what + + + align:start position:0% +were going we were going to look at what +are the reactive oxygen species + + align:start position:0% +are the reactive oxygen species + + + align:start position:0% +are the reactive oxygen species +what does reactivity mean how do you + + align:start position:0% +what does reactivity mean how do you + + + align:start position:0% +what does reactivity mean how do you +define chemical reactivity I think + + align:start position:0% +define chemical reactivity I think + + + align:start position:0% +define chemical reactivity I think +that's a key issue and then what are + + align:start position:0% +that's a key issue and then what are + + + align:start position:0% +that's a key issue and then what are +defense mechanisms against these + + align:start position:0% +defense mechanisms against these + + + align:start position:0% +defense mechanisms against these +reactive oxygen species before then + + align:start position:0% +reactive oxygen species before then + + + align:start position:0% +reactive oxygen species before then +focusing on the NADPH oxidase which are + + align:start position:0% +focusing on the NADPH oxidase which are + + + align:start position:0% +focusing on the NADPH oxidase which are +the focus those are the enzymes that + + align:start position:0% +the focus those are the enzymes that + + + align:start position:0% +the focus those are the enzymes that +were focused on in this whole module on + + align:start position:0% +were focused on in this whole module on + + + align:start position:0% +were focused on in this whole module on +reactive oxygen species + + align:start position:0% +reactive oxygen species + + + align:start position:0% +reactive oxygen species +okay so identification + + align:start position:0% + + + + align:start position:0% + +okay and I had put this on the board the + + align:start position:0% +okay and I had put this on the board the + + + align:start position:0% +okay and I had put this on the board the +last time we have just repeating what's + + align:start position:0% +last time we have just repeating what's + + + align:start position:0% +last time we have just repeating what's +over there super oxide hydroxide radical + + align:start position:0% +over there super oxide hydroxide radical + + + align:start position:0% +over there super oxide hydroxide radical +hydrogen peroxide this is together and + + align:start position:0% +hydrogen peroxide this is together and + + + align:start position:0% +hydrogen peroxide this is together and +hypochlorous acid okay and we're gonna + + align:start position:0% +hypochlorous acid okay and we're gonna + + + align:start position:0% +hypochlorous acid okay and we're gonna +look at the reactivity of these guys + + align:start position:0% +look at the reactivity of these guys + + + align:start position:0% +look at the reactivity of these guys +these are one electron oxidants these + + align:start position:0% +these are one electron oxidants these + + + align:start position:0% +these are one electron oxidants these +are two electron oxidants so reactive + + align:start position:0% +are two electron oxidants so reactive + + + align:start position:0% +are two electron oxidants so reactive +species don't need to have free radicals + + align:start position:0% +species don't need to have free radicals + + + align:start position:0% +species don't need to have free radicals +they can do two electron chemistry or + + align:start position:0% +they can do two electron chemistry or + + + align:start position:0% +they can do two electron chemistry or +they can do one electron chemistry okay + + align:start position:0% +they can do one electron chemistry okay + + + align:start position:0% +they can do one electron chemistry okay +so a key thing to think about and I + + align:start position:0% +so a key thing to think about and I + + + align:start position:0% +so a key thing to think about and I +don't expect you to remember the + + align:start position:0% +don't expect you to remember the + + + align:start position:0% +don't expect you to remember the +detailed reduction potentials but again + + align:start position:0% +detailed reduction potentials but again + + + align:start position:0% +detailed reduction potentials but again +as the inadvertent consequence of our + + align:start position:0% +as the inadvertent consequence of our + + + align:start position:0% +as the inadvertent consequence of our +environment you know one point eight to + + align:start position:0% +environment you know one point eight to + + + align:start position:0% +environment you know one point eight to +eight point eight billion years ago we + + align:start position:0% +eight point eight billion years ago we + + + align:start position:0% +eight point eight billion years ago we +moved from an anaerobic to anaerobic + + align:start position:0% +moved from an anaerobic to anaerobic + + + align:start position:0% +moved from an anaerobic to anaerobic +world we have metals all over the place + + align:start position:0% +world we have metals all over the place + + + align:start position:0% +world we have metals all over the place +the question is how do you control these + + align:start position:0% +the question is how do you control these + + + align:start position:0% +the question is how do you control these +reactivities and so we need to think + + align:start position:0% +reactivities and so we need to think + + + align:start position:0% +reactivities and so we need to think +about the redox chemistry of oxygen so + + align:start position:0% +about the redox chemistry of oxygen so + + + align:start position:0% +about the redox chemistry of oxygen so +oxygen and and the details the actual + + align:start position:0% +oxygen and and the details the actual + + + align:start position:0% +oxygen and and the details the actual +reduction potentials and these are some + + align:start position:0% +reduction potentials and these are some + + + align:start position:0% +reduction potentials and these are some +of them given here and this one somehow + + align:start position:0% +of them given here and this one somehow + + + align:start position:0% +of them given here and this one somehow +got lost from here to here which is 0.94 + + align:start position:0% +got lost from here to here which is 0.94 + + + align:start position:0% +got lost from here to here which is 0.94 +but it's in a table later on and the + + align:start position:0% +but it's in a table later on and the + + + align:start position:0% +but it's in a table later on and the +power points depend on the balanced + + align:start position:0% +power points depend on the balanced + + + align:start position:0% +power points depend on the balanced +equation okay so if you're looking at + + align:start position:0% +equation okay so if you're looking at + + + align:start position:0% +equation okay so if you're looking at +this and you really want to think about + + align:start position:0% +this and you really want to think about + + + align:start position:0% +this and you really want to think about +the reduction potentials you need to + + align:start position:0% +the reduction potentials you need to + + + align:start position:0% +the reduction potentials you need to +count the numbers of electrons and + + align:start position:0% +count the numbers of electrons and + + + align:start position:0% +count the numbers of electrons and +protons and balance the equation that + + align:start position:0% +protons and balance the equation that + + + align:start position:0% +protons and balance the equation that +you're looking at because reduction + + align:start position:0% +you're looking at because reduction + + + align:start position:0% +you're looking at because reduction +potentials vary but what you need to + + align:start position:0% +potentials vary but what you need to + + + align:start position:0% +potentials vary but what you need to +remember is a more positive the more + + align:start position:0% +remember is a more positive the more + + + align:start position:0% +remember is a more positive the more +positive the number is the easier it is + + align:start position:0% +positive the number is the easier it is + + + align:start position:0% +positive the number is the easier it is +to reduce the more powerful the oxidant + + align:start position:0% +to reduce the more powerful the oxidant + + + align:start position:0% +to reduce the more powerful the oxidant +okay so we're gonna have oxygen and in + + align:start position:0% +okay so we're gonna have oxygen and in + + + align:start position:0% +okay so we're gonna have oxygen and in +the first one we have one electron + + align:start position:0% +the first one we have one electron + + + align:start position:0% +the first one we have one electron +reduction and this is the only one where + + align:start position:0% +reduction and this is the only one where + + + align:start position:0% +reduction and this is the only one where +the reduction potential is negative okay + + align:start position:0% +the reduction potential is negative okay + + + align:start position:0% +the reduction potential is negative okay +so this is a pill it doesn't + + align:start position:0% +so this is a pill it doesn't + + + align:start position:0% +so this is a pill it doesn't +want to be oxidized and this produces + + align:start position:0% + + + + align:start position:0% + +superoxide okay so okay so this is one + + align:start position:0% +superoxide okay so okay so this is one + + + align:start position:0% +superoxide okay so okay so this is one +of the guys we're going to be talking + + align:start position:0% +of the guys we're going to be talking + + + align:start position:0% +of the guys we're going to be talking +about and here's the reduction potential + + align:start position:0% +about and here's the reduction potential + + + align:start position:0% +about and here's the reduction potential +this can be further reduced with an + + align:start position:0% +this can be further reduced with an + + + align:start position:0% +this can be further reduced with an +electron and a couple of protons to form + + align:start position:0% +electron and a couple of protons to form + + + align:start position:0% +electron and a couple of protons to form +hydrogen peroxide so I'm not going to + + align:start position:0% +hydrogen peroxide so I'm not going to + + + align:start position:0% +hydrogen peroxide so I'm not going to +write that out everybody hopefully knows + + align:start position:0% +write that out everybody hopefully knows + + + align:start position:0% +write that out everybody hopefully knows +what hydrogen peroxide is and this is + + align:start position:0% +what hydrogen peroxide is and this is + + + align:start position:0% +what hydrogen peroxide is and this is +the number that for some some reason got + + align:start position:0% +the number that for some some reason got + + + align:start position:0% +the number that for some some reason got +left off that handout and this is + + align:start position:0% +left off that handout and this is + + + align:start position:0% +left off that handout and this is +favorable and so are all the other + + align:start position:0% +favorable and so are all the other + + + align:start position:0% +favorable and so are all the other +numbers and the numbers are actually + + align:start position:0% +numbers and the numbers are actually + + + align:start position:0% +numbers and the numbers are actually +large and favorable that means that good + + align:start position:0% +large and favorable that means that good + + + align:start position:0% +large and favorable that means that good +oxidants okay so more positive better + + align:start position:0% + + + + align:start position:0% + +oxidants and these are all relative + + align:start position:0% +oxidants and these are all relative + + + align:start position:0% +oxidants and these are all relative +these are all biological reduction + + align:start position:0% +these are all biological reduction + + + align:start position:0% +these are all biological reduction +potentials relative to the normal + + align:start position:0% +potentials relative to the normal + + + align:start position:0% +potentials relative to the normal +hydrogen electrode okay so these are the + + align:start position:0% +hydrogen electrode okay so these are the + + + align:start position:0% +hydrogen electrode okay so these are the +ones there's actually a table in there + + align:start position:0% +ones there's actually a table in there + + + align:start position:0% +ones there's actually a table in there +we you see the numbers that people + + align:start position:0% +we you see the numbers that people + + + align:start position:0% +we you see the numbers that people +interested in biological systems focus + + align:start position:0% +interested in biological systems focus + + + align:start position:0% +interested in biological systems focus +on now we'll see later on that hydrogen + + align:start position:0% +on now we'll see later on that hydrogen + + + align:start position:0% +on now we'll see later on that hydrogen +peroxide gives rise to hypochlorous acid + + align:start position:0% +peroxide gives rise to hypochlorous acid + + + align:start position:0% +peroxide gives rise to hypochlorous acid +and the presence of chloride okay but + + align:start position:0% +and the presence of chloride okay but + + + align:start position:0% +and the presence of chloride okay but +hydrogen peroxide can also get further + + align:start position:0% +hydrogen peroxide can also get further + + + align:start position:0% +hydrogen peroxide can also get further +reduced - and this is one where I don't + + align:start position:0% +reduced - and this is one where I don't + + + align:start position:0% +reduced - and this is one where I don't +have the balanced equation hydroxide + + align:start position:0% +have the balanced equation hydroxide + + + align:start position:0% +have the balanced equation hydroxide +radical and so the number I have written + + align:start position:0% +radical and so the number I have written + + + align:start position:0% +radical and so the number I have written +down here is 0.38 volts but again the + + align:start position:0% +down here is 0.38 volts but again the + + + align:start position:0% +down here is 0.38 volts but again the +numbers aren't so important and then + + align:start position:0% +numbers aren't so important and then + + + align:start position:0% +numbers aren't so important and then +this can get further reduced to water + + align:start position:0% +this can get further reduced to water + + + align:start position:0% +this can get further reduced to water +and this number is you'll see in a + + align:start position:0% +and this number is you'll see in a + + + align:start position:0% +and this number is you'll see in a +number of the tables I give you as one + + align:start position:0% +number of the tables I give you as one + + + align:start position:0% +number of the tables I give you as one +point three one volts + + align:start position:0% +point three one volts + + + align:start position:0% +point three one volts +so we have different states in all three + + align:start position:0% +so we have different states in all three + + + align:start position:0% +so we have different states in all three +states a consequence of moving from the + + align:start position:0% +states a consequence of moving from the + + + align:start position:0% +states a consequence of moving from the +anaerobic to the aerobic world out give + + align:start position:0% +anaerobic to the aerobic world out give + + + align:start position:0% +anaerobic to the aerobic world out give +you species that are called reactive + + align:start position:0% +you species that are called reactive + + + align:start position:0% +you species that are called reactive +oxygen species okay + + align:start position:0% +oxygen species okay + + + align:start position:0% +oxygen species okay +and the one that's how the hardest form + + align:start position:0% +and the one that's how the hardest form + + + align:start position:0% +and the one that's how the hardest form +is superoxide and this is the one that's + + align:start position:0% +is superoxide and this is the one that's + + + align:start position:0% +is superoxide and this is the one that's +probably the least reactive okay but + + align:start position:0% +probably the least reactive okay but + + + align:start position:0% +probably the least reactive okay but +what I'm going to do is give you + + align:start position:0% +what I'm going to do is give you + + + align:start position:0% +what I'm going to do is give you +criteria for re a couple sets of + + align:start position:0% +criteria for re a couple sets of + + + align:start position:0% +criteria for re a couple sets of +criteria for reactivity because when + + align:start position:0% +criteria for reactivity because when + + + align:start position:0% +criteria for reactivity because when +people say something is chemically + + align:start position:0% +people say something is chemically + + + align:start position:0% +people say something is chemically +reactive you know what does that mean + + align:start position:0% +reactive you know what does that mean + + + align:start position:0% +reactive you know what does that mean +okay it depends on what it is reacting + + align:start position:0% +okay it depends on what it is reacting + + + align:start position:0% +okay it depends on what it is reacting +with and so this I think is the real + + align:start position:0% +with and so this I think is the real + + + align:start position:0% +with and so this I think is the real +problem in the field is that people + + align:start position:0% +problem in the field is that people + + + align:start position:0% +problem in the field is that people +really don't define this very well and + + align:start position:0% +really don't define this very well and + + + align:start position:0% +really don't define this very well and +so this is why I think the Winterbourne + + align:start position:0% +so this is why I think the Winterbourne + + + align:start position:0% +so this is why I think the Winterbourne +paper is so important + + align:start position:0% +paper is so important + + + align:start position:0% +paper is so important +so she has a table and there I'm gonna + + align:start position:0% +so she has a table and there I'm gonna + + + align:start position:0% +so she has a table and there I'm gonna +have the table if there I reorganized + + align:start position:0% +have the table if there I reorganized + + + align:start position:0% +have the table if there I reorganized +the table to focus on what I want to + + align:start position:0% +the table to focus on what I want to + + + align:start position:0% +the table to focus on what I want to +focus on and in this brief introduction + + align:start position:0% +focus on and in this brief introduction + + + align:start position:0% +focus on and in this brief introduction +to this topic and show you how they + + align:start position:0% +to this topic and show you how they + + + align:start position:0% +to this topic and show you how they +define reactivity but if you're thinking + + align:start position:0% +define reactivity but if you're thinking + + + align:start position:0% +define reactivity but if you're thinking +about something you need to define what + + align:start position:0% +about something you need to define what + + + align:start position:0% +about something you need to define what +the reaction is that you're interested + + align:start position:0% +the reaction is that you're interested + + + align:start position:0% +the reaction is that you're interested +in with any of these reactive oxygen + + align:start position:0% +in with any of these reactive oxygen + + + align:start position:0% +in with any of these reactive oxygen +species okay so so these are the guys we + + align:start position:0% +species okay so so these are the guys we + + + align:start position:0% +species okay so so these are the guys we +care about okay and the second question + + align:start position:0% +care about okay and the second question + + + align:start position:0% +care about okay and the second question +I wanted to address is so first we were + + align:start position:0% +I wanted to address is so first we were + + + align:start position:0% +I wanted to address is so first we were +identifying last time the I the + + align:start position:0% +identifying last time the I the + + + align:start position:0% +identifying last time the I the +identifications second is a chemical + + align:start position:0% +identifications second is a chemical + + + align:start position:0% +identifications second is a chemical +reactivity okay and I've taken this + + align:start position:0% +reactivity okay and I've taken this + + + align:start position:0% +reactivity okay and I've taken this +maybe it wasn't from her paper I can't + + align:start position:0% +maybe it wasn't from her paper I can't + + + align:start position:0% +maybe it wasn't from her paper I can't +remember where I've taken this so I + + align:start position:0% +remember where I've taken this so I + + + align:start position:0% +remember where I've taken this so I +should have referenced it but anyhow + + align:start position:0% +should have referenced it but anyhow + + + align:start position:0% +should have referenced it but anyhow +what I'm gonna do is give you a simple + + align:start position:0% +what I'm gonna do is give you a simple + + + align:start position:0% +what I'm gonna do is give you a simple +table that I think is useful to think + + align:start position:0% +table that I think is useful to think + + + align:start position:0% +table that I think is useful to think +about reactivity okay so if we look at + + align:start position:0% +about reactivity okay so if we look at + + + align:start position:0% +about reactivity okay so if we look at +reactivity we're gonna look at the + + align:start position:0% +reactivity we're gonna look at the + + + align:start position:0% +reactivity we're gonna look at the +oxidant and then another cat or category + + align:start position:0% +oxidant and then another cat or category + + + align:start position:0% +oxidant and then another cat or category +is going to be the biological defense + + align:start position:0% +is going to be the biological defense + + + align:start position:0% +is going to be the biological defense +and the third category is + + align:start position:0% +and the third category is + + + align:start position:0% +and the third category is +thermodynamic properties and you all + + align:start position:0% +thermodynamic properties and you all + + + align:start position:0% +thermodynamic properties and you all +know that things can be + + align:start position:0% +know that things can be + + + align:start position:0% +know that things can be +thermodynamically favorable but not + + align:start position:0% +thermodynamically favorable but not + + + align:start position:0% +thermodynamically favorable but not +happen at all like oxygen oxidizing + + align:start position:0% +happen at all like oxygen oxidizing + + + align:start position:0% +happen at all like oxygen oxidizing +glucose on the table okay so you not + + align:start position:0% +glucose on the table okay so you not + + + align:start position:0% +glucose on the table okay so you not +only need to think about the + + align:start position:0% +only need to think about the + + + align:start position:0% +only need to think about the +thermodynamics which involves the redox + + align:start position:0% +thermodynamics which involves the redox + + + align:start position:0% +thermodynamics which involves the redox +potentials and you need to define the + + align:start position:0% +potentials and you need to define the + + + align:start position:0% +potentials and you need to define the +sets of conditions that you're looking + + align:start position:0% +sets of conditions that you're looking + + + align:start position:0% +sets of conditions that you're looking +under but then you need to also think + + align:start position:0% +under but then you need to also think + + + align:start position:0% +under but then you need to also think +about the kinetics + + align:start position:0% +about the kinetics + + + align:start position:0% +about the kinetics +okay so we have thermodynamics so here + + align:start position:0% +okay so we have thermodynamics so here + + + align:start position:0% +okay so we have thermodynamics so here +biological defense thermodynamics and + + align:start position:0% +biological defense thermodynamics and + + + align:start position:0% +biological defense thermodynamics and +then the kinetic properties and the + + align:start position:0% +then the kinetic properties and the + + + align:start position:0% +then the kinetic properties and the +kinetic properties are often given in + + align:start position:0% +kinetic properties are often given in + + + align:start position:0% +kinetic properties are often given in +terms of reactivity with a molecule + + align:start position:0% +terms of reactivity with a molecule + + + align:start position:0% +terms of reactivity with a molecule +called glutathione I'm not gonna draw + + align:start position:0% +called glutathione I'm not gonna draw + + + align:start position:0% +called glutathione I'm not gonna draw +out the structure but it's a tripeptide + + align:start position:0% +out the structure but it's a tripeptide + + + align:start position:0% +out the structure but it's a tripeptide +with gamma gluten meal cysteine glycine + + align:start position:0% +with gamma gluten meal cysteine glycine + + + align:start position:0% +with gamma gluten meal cysteine glycine +okay so it's a tribe peptide with an + + align:start position:0% +okay so it's a tribe peptide with an + + + align:start position:0% +okay so it's a tribe peptide with an +unusual linkage to the next amino acid + + align:start position:0% +unusual linkage to the next amino acid + + + align:start position:0% +unusual linkage to the next amino acid +what do you know about glutathione have + + align:start position:0% +what do you know about glutathione have + + + align:start position:0% +what do you know about glutathione have +you guys ever seen that before so it's a + + align:start position:0% +you guys ever seen that before so it's a + + + align:start position:0% +you guys ever seen that before so it's a +major redox buffer inside human cells + + align:start position:0% +major redox buffer inside human cells + + + align:start position:0% +major redox buffer inside human cells +okay now if you're in a micro organism + + align:start position:0% +okay now if you're in a micro organism + + + align:start position:0% +okay now if you're in a micro organism +we don't think it's the same major redox + + align:start position:0% +we don't think it's the same major redox + + + align:start position:0% +we don't think it's the same major redox +thinks that you need to look at that but + + align:start position:0% +thinks that you need to look at that but + + + align:start position:0% +thinks that you need to look at that but +all organisms have redox buffers and as + + align:start position:0% +all organisms have redox buffers and as + + + align:start position:0% +all organisms have redox buffers and as +you can imagine and this is why we've + + align:start position:0% +you can imagine and this is why we've + + + align:start position:0% +you can imagine and this is why we've +been we focused on with a mass spec + + align:start position:0% +been we focused on with a mass spec + + + align:start position:0% +been we focused on with a mass spec +stuff so so phenol ation one of the + + align:start position:0% +stuff so so phenol ation one of the + + + align:start position:0% +stuff so so phenol ation one of the +major targets of out-of-control + + align:start position:0% +major targets of out-of-control + + + align:start position:0% +major targets of out-of-control +reactive oxygen species is oxidation of + + align:start position:0% +reactive oxygen species is oxidation of + + + align:start position:0% +reactive oxygen species is oxidation of +cystines those there are other amino + + align:start position:0% +cystines those there are other amino + + + align:start position:0% +cystines those there are other amino +acids that get oxidized but the focus is + + align:start position:0% +acids that get oxidized but the focus is + + + align:start position:0% +acids that get oxidized but the focus is +on the cysteine ohm and all the changes + + align:start position:0% +on the cysteine ohm and all the changes + + + align:start position:0% +on the cysteine ohm and all the changes +that can be made in all the signaling + + align:start position:0% +that can be made in all the signaling + + + align:start position:0% +that can be made in all the signaling +most of the signaling through reactive + + align:start position:0% +most of the signaling through reactive + + + align:start position:0% +most of the signaling through reactive +oxygen species all go through cysteine + + align:start position:0% +oxygen species all go through cysteine + + + align:start position:0% +oxygen species all go through cysteine +oxidation so this is a reasonable choice + + align:start position:0% +oxidation so this is a reasonable choice + + + align:start position:0% +oxidation so this is a reasonable choice +Gamla glutamate so just to me right now + + align:start position:0% +Gamla glutamate so just to me right now + + + align:start position:0% +Gamla glutamate so just to me right now +it's a tripeptide of glutamate cysteine + + align:start position:0% +it's a tripeptide of glutamate cysteine + + + align:start position:0% +it's a tripeptide of glutamate cysteine +and glycine with an unusual linkage here + + align:start position:0% +and glycine with an unusual linkage here + + + align:start position:0% +and glycine with an unusual linkage here +with a I so I so peptide linkage okay so + + align:start position:0% +with a I so I so peptide linkage okay so + + + align:start position:0% +with a I so I so peptide linkage okay so +the first one the first two are + + align:start position:0% +the first one the first two are + + + align:start position:0% +the first one the first two are +electron oxidants and the first one to + + align:start position:0% +electron oxidants and the first one to + + + align:start position:0% +electron oxidants and the first one to +talk about is hydroxide radical + + align:start position:0% +talk about is hydroxide radical + + + align:start position:0% +talk about is hydroxide radical +hydroxide radical you'll see by firing + + align:start position:0% +hydroxide radical you'll see by firing + + + align:start position:0% +hydroxide radical you'll see by firing +away is one of the most reactive and + + align:start position:0% +away is one of the most reactive and + + + align:start position:0% +away is one of the most reactive and +it's dying to be reduced as you can tell + + align:start position:0% +it's dying to be reduced as you can tell + + + align:start position:0% +it's dying to be reduced as you can tell +by this reduction potential no matter + + align:start position:0% +by this reduction potential no matter + + + align:start position:0% +by this reduction potential no matter +what the variation on the theme is and + + align:start position:0% +what the variation on the theme is and + + + align:start position:0% +what the variation on the theme is and +there is no defense so you don't want to + + align:start position:0% +there is no defense so you don't want to + + + align:start position:0% +there is no defense so you don't want to +get to hydroxide radicals so there's no + + align:start position:0% +get to hydroxide radicals so there's no + + + align:start position:0% +get to hydroxide radicals so there's no +no actual defense and that's not + + align:start position:0% +no actual defense and that's not + + + align:start position:0% +no actual defense and that's not +completely true because in reality if + + align:start position:0% +completely true because in reality if + + + align:start position:0% +completely true because in reality if +you have glutathione around the + + align:start position:0% +you have glutathione around the + + + align:start position:0% +you have glutathione around the +glutathione will reduce this by hydrogen + + align:start position:0% +glutathione will reduce this by hydrogen + + + align:start position:0% +glutathione will reduce this by hydrogen +atom transfer okay so an important + + align:start position:0% +atom transfer okay so an important + + + align:start position:0% +atom transfer okay so an important +component is the redox buffer so + + align:start position:0% +component is the redox buffer so + + + align:start position:0% +component is the redox buffer so +glutathione let me just write that down + + align:start position:0% +glutathione let me just write that down + + + align:start position:0% +glutathione let me just write that down +again because we're not gonna have time + + align:start position:0% +again because we're not gonna have time + + + align:start position:0% +again because we're not gonna have time +to talk about this but we Knox buffers + + align:start position:0% +to talk about this but we Knox buffers + + + align:start position:0% +to talk about this but we Knox buffers +play a central role and reactive oxygen + + align:start position:0% +play a central role and reactive oxygen + + + align:start position:0% +play a central role and reactive oxygen +species okay and so the thermodynamics + + align:start position:0% +species okay and so the thermodynamics + + + align:start position:0% +species okay and so the thermodynamics +of this dying to be reduced if I have + + align:start position:0% +of this dying to be reduced if I have + + + align:start position:0% +of this dying to be reduced if I have +the numbers right I think I don't + + align:start position:0% +the numbers right I think I don't + + + align:start position:0% +the numbers right I think I don't +remember what the numbers were okay so + + align:start position:0% +remember what the numbers were okay so + + + align:start position:0% +remember what the numbers were okay so +the number is here 0.31 I have different + + align:start position:0% +the number is here 0.31 I have different + + + align:start position:0% +the number is here 0.31 I have different +numbers in different places + + align:start position:0% +numbers in different places + + + align:start position:0% +numbers in different places +okay but anyhow it doesn't matter it's + + align:start position:0% +okay but anyhow it doesn't matter it's + + + align:start position:0% +okay but anyhow it doesn't matter it's +dying to be reduced okay so it's a hot + + align:start position:0% +dying to be reduced okay so it's a hot + + + align:start position:0% +dying to be reduced okay so it's a hot +oxidant and then the rate constant for + + align:start position:0% +oxidant and then the rate constant for + + + align:start position:0% +oxidant and then the rate constant for +reaction with glutathione okay so it + + align:start position:0% +reaction with glutathione okay so it + + + align:start position:0% +reaction with glutathione okay so it +would be H dot transfer and this is a by + + align:start position:0% +would be H dot transfer and this is a by + + + align:start position:0% +would be H dot transfer and this is a by +molecular rate constant is 1 times 10 to + + align:start position:0% +molecular rate constant is 1 times 10 to + + + align:start position:0% +molecular rate constant is 1 times 10 to +the 10th per molar per second so this is + + align:start position:0% +the 10th per molar per second so this is + + + align:start position:0% +the 10th per molar per second so this is +really fast and so if you cut + + align:start position:0% +really fast and so if you cut + + + align:start position:0% +really fast and so if you cut +glutathione around your hydroxide + + align:start position:0% +glutathione around your hydroxide + + + align:start position:0% +glutathione around your hydroxide +radical is gone we're gonna look at + + align:start position:0% +radical is gone we're gonna look at + + + align:start position:0% +radical is gone we're gonna look at +another way of trying to define + + align:start position:0% +another way of trying to define + + + align:start position:0% +another way of trying to define +reactivity but this is a way that people + + align:start position:0% +reactivity but this is a way that people + + + align:start position:0% +reactivity but this is a way that people +who were trying to think about the + + align:start position:0% +who were trying to think about the + + + align:start position:0% +who were trying to think about the +kinetics of long lists are starting to + + align:start position:0% +kinetics of long lists are starting to + + + align:start position:0% +kinetics of long lists are starting to +do this so okay so this is one the + + align:start position:0% +do this so okay so this is one the + + + align:start position:0% +do this so okay so this is one the +second species which is also a one + + align:start position:0% +second species which is also a one + + + align:start position:0% +second species which is also a one +electron redox + + align:start position:0% +electron redox + + + align:start position:0% +electron redox +- its superoxide and this is the one one + + align:start position:0% +- its superoxide and this is the one one + + + align:start position:0% +- its superoxide and this is the one one +seed - described most frequently as a + + align:start position:0% +seed - described most frequently as a + + + align:start position:0% +seed - described most frequently as a +reactive oxygen species and reality it's + + align:start position:0% +reactive oxygen species and reality it's + + + align:start position:0% +reactive oxygen species and reality it's +not very reactive at all + + align:start position:0% +not very reactive at all + + + align:start position:0% +not very reactive at all +it is reactive but not anywhere near as + + align:start position:0% +it is reactive but not anywhere near as + + + align:start position:0% +it is reactive but not anywhere near as +reactive as some of the others and do we + + align:start position:0% +reactive as some of the others and do we + + + align:start position:0% +reactive as some of the others and do we +have a defense mechanism we'll come back + + align:start position:0% +have a defense mechanism we'll come back + + + align:start position:0% +have a defense mechanism we'll come back +to this a little and I'll write a + + align:start position:0% +to this a little and I'll write a + + + align:start position:0% +to this a little and I'll write a +balanced equation I'm just gonna list + + align:start position:0% +balanced equation I'm just gonna list + + + align:start position:0% +balanced equation I'm just gonna list +things we have enzymes called s Odie's + + align:start position:0% +things we have enzymes called s Odie's + + + align:start position:0% +things we have enzymes called s Odie's +and so this is superoxide dismutase and + + align:start position:0% +and so this is superoxide dismutase and + + + align:start position:0% +and so this is superoxide dismutase and +I'll come back and write a balanced + + align:start position:0% +I'll come back and write a balanced + + + align:start position:0% +I'll come back and write a balanced +equation in a minute okay so we have + + align:start position:0% +equation in a minute okay so we have + + + align:start position:0% +equation in a minute okay so we have +proteins that are devoted to this but in + + align:start position:0% +proteins that are devoted to this but in + + + align:start position:0% +proteins that are devoted to this but in +reality metals like manganese inside the + + align:start position:0% +reality metals like manganese inside the + + + align:start position:0% +reality metals like manganese inside the +cell can actually function as a + + align:start position:0% +cell can actually function as a + + + align:start position:0% +cell can actually function as a +superoxide dismutase at reasonable rates + + align:start position:0% +superoxide dismutase at reasonable rates + + + align:start position:0% +superoxide dismutase at reasonable rates +protons cause rapid just mutation to + + align:start position:0% +protons cause rapid just mutation to + + + align:start position:0% +protons cause rapid just mutation to +form hydrogen peroxide and oxygen this + + align:start position:0% +form hydrogen peroxide and oxygen this + + + align:start position:0% +form hydrogen peroxide and oxygen this +guy is also dying to be reduced so + + align:start position:0% +guy is also dying to be reduced so + + + align:start position:0% +guy is also dying to be reduced so +thermodynamics this is a good oxidant + + align:start position:0% +thermodynamics this is a good oxidant + + + align:start position:0% +thermodynamics this is a good oxidant +but the key is thinking about the + + align:start position:0% +but the key is thinking about the + + + align:start position:0% +but the key is thinking about the +kinetics and it obviously depends on the + + align:start position:0% +kinetics and it obviously depends on the + + + align:start position:0% +kinetics and it obviously depends on the +reaction you're looking at the kinetics + + align:start position:0% +reaction you're looking at the kinetics + + + align:start position:0% +reaction you're looking at the kinetics +are going to be different with every + + align:start position:0% +are going to be different with every + + + align:start position:0% +are going to be different with every +small molecule and or a large molecule + + align:start position:0% +small molecule and or a large molecule + + + align:start position:0% +small molecule and or a large molecule +that interacts with but people again + + align:start position:0% +that interacts with but people again + + + align:start position:0% +that interacts with but people again +we're using glutathione as an example + + align:start position:0% +we're using glutathione as an example + + + align:start position:0% +we're using glutathione as an example +and the numbers that people report for + + align:start position:0% +and the numbers that people report for + + + align:start position:0% +and the numbers that people report for +superoxide compared to 1 times 10 to the + + align:start position:0% +superoxide compared to 1 times 10 to the + + + align:start position:0% +superoxide compared to 1 times 10 to the +10th are now ten to a thousand per molar + + align:start position:0% +10th are now ten to a thousand per molar + + + align:start position:0% +10th are now ten to a thousand per molar +per second okay so this is chemically + + align:start position:0% +per second okay so this is chemically + + + align:start position:0% +per second okay so this is chemically +much less reactive than hydroxide + + align:start position:0% +much less reactive than hydroxide + + + align:start position:0% +much less reactive than hydroxide +radical and even for this one we have a + + align:start position:0% +radical and even for this one we have a + + + align:start position:0% +radical and even for this one we have a +defense we have a defense mechanism this + + align:start position:0% +defense we have a defense mechanism this + + + align:start position:0% +defense we have a defense mechanism this +one again is problematic okay so now + + align:start position:0% +one again is problematic okay so now + + + align:start position:0% +one again is problematic okay so now +what we're going to switch to is two + + align:start position:0% +what we're going to switch to is two + + + align:start position:0% +what we're going to switch to is two +electron to electron oxidants and the + + align:start position:0% +electron to electron oxidants and the + + + align:start position:0% +electron to electron oxidants and the +one we're going to focus on today in the + + align:start position:0% +one we're going to focus on today in the + + + align:start position:0% +one we're going to focus on today in the +section of what happens in neutrophils + + align:start position:0% +section of what happens in neutrophils + + + align:start position:0% +section of what happens in neutrophils +to + + align:start position:0% +to + + + align:start position:0% +to +and against invading organisms like + + align:start position:0% +and against invading organisms like + + + align:start position:0% +and against invading organisms like +bacteria or viruses or parasites the + + align:start position:0% +bacteria or viruses or parasites the + + + align:start position:0% +bacteria or viruses or parasites the +major way that this becomes neutralized + + align:start position:0% +major way that this becomes neutralized + + + align:start position:0% +major way that this becomes neutralized +inside the cell is again in the enema + + align:start position:0% +inside the cell is again in the enema + + + align:start position:0% +inside the cell is again in the enema +million cell is with glutathione so this + + align:start position:0% +million cell is with glutathione so this + + + align:start position:0% +million cell is with glutathione so this +is a small molecule it also is a very + + align:start position:0% +is a small molecule it also is a very + + + align:start position:0% +is a small molecule it also is a very +strong oxidant but the mechanism of + + align:start position:0% +strong oxidant but the mechanism of + + + align:start position:0% +strong oxidant but the mechanism of +oxidation is distinct two electrons + + align:start position:0% +oxidation is distinct two electrons + + + align:start position:0% +oxidation is distinct two electrons +versus one electron we're gonna look at + + align:start position:0% +versus one electron we're gonna look at + + + align:start position:0% +versus one electron we're gonna look at +examples of this and if you look at the + + align:start position:0% +examples of this and if you look at the + + + align:start position:0% +examples of this and if you look at the +rate constant for reaction with + + align:start position:0% +rate constant for reaction with + + + align:start position:0% +rate constant for reaction with +glutathione and again you need to look + + align:start position:0% +glutathione and again you need to look + + + align:start position:0% +glutathione and again you need to look +you need to really think about a + + align:start position:0% +you need to really think about a + + + align:start position:0% +you need to really think about a +balanced equation and the kinetics of + + align:start position:0% +balanced equation and the kinetics of + + + align:start position:0% +balanced equation and the kinetics of +all of these things that's if you're + + align:start position:0% +all of these things that's if you're + + + align:start position:0% +all of these things that's if you're +ever gonna work in this area that's what + + align:start position:0% +ever gonna work in this area that's what + + + align:start position:0% +ever gonna work in this area that's what +you need to do you need to educate + + align:start position:0% +you need to do you need to educate + + + align:start position:0% +you need to do you need to educate +yourself about what the species are with + + align:start position:0% +yourself about what the species are with + + + align:start position:0% +yourself about what the species are with +which you're going to interact but you + + align:start position:0% +which you're going to interact but you + + + align:start position:0% +which you're going to interact but you +can see from this number under the sets + + align:start position:0% +can see from this number under the sets + + + align:start position:0% +can see from this number under the sets +of conditions they did everything the + + align:start position:0% +of conditions they did everything the + + + align:start position:0% +of conditions they did everything the +same way so that they could compare the + + align:start position:0% +same way so that they could compare the + + + align:start position:0% +same way so that they could compare the +relative reactivity of these molecules + + align:start position:0% +relative reactivity of these molecules + + + align:start position:0% +relative reactivity of these molecules +two times ten to the seventh so this is + + align:start position:0% +two times ten to the seventh so this is + + + align:start position:0% +two times ten to the seventh so this is +much more reactive for example in + + align:start position:0% +much more reactive for example in + + + align:start position:0% +much more reactive for example in +superoxide okay and then the last one + + align:start position:0% +superoxide okay and then the last one + + + align:start position:0% +superoxide okay and then the last one +the last one is hydrogen peroxide so + + align:start position:0% +the last one is hydrogen peroxide so + + + align:start position:0% +the last one is hydrogen peroxide so +this is also two electron and two + + align:start position:0% +this is also two electron and two + + + align:start position:0% +this is also two electron and two +electron we will see that there are a + + align:start position:0% +electron we will see that there are a + + + align:start position:0% +electron we will see that there are a +number of proteins that mount a defense + + align:start position:0% +number of proteins that mount a defense + + + align:start position:0% +number of proteins that mount a defense +these are called and I'm gonna show you + + align:start position:0% +these are called and I'm gonna show you + + + align:start position:0% +these are called and I'm gonna show you +this in a minute pair oxy redox ins I'll + + align:start position:0% +this in a minute pair oxy redox ins I'll + + + align:start position:0% +this in a minute pair oxy redox ins I'll +show you what they do what did you see + + align:start position:0% +show you what they do what did you see + + + align:start position:0% +show you what they do what did you see +do you remember the paper the the enzyme + + align:start position:0% +do you remember the paper the the enzyme + + + align:start position:0% +do you remember the paper the the enzyme +that was used in the in the Carroll + + align:start position:0% +that was used in the in the Carroll + + + align:start position:0% +that was used in the in the Carroll +paper this week in recitation to get rid + + align:start position:0% +paper this week in recitation to get rid + + + align:start position:0% +paper this week in recitation to get rid +of hydrogen peroxide why do they use + + align:start position:0% +of hydrogen peroxide why do they use + + + align:start position:0% +of hydrogen peroxide why do they use +anybody remember + + align:start position:0% + + + + align:start position:0% + +cattle we use catalase I'm going to come + + align:start position:0% +cattle we use catalase I'm going to come + + + align:start position:0% +cattle we use catalase I'm going to come +back and write the equations of catalase + + align:start position:0% +back and write the equations of catalase + + + align:start position:0% +back and write the equations of catalase +and then the other one which we also + + align:start position:0% +and then the other one which we also + + + align:start position:0% +and then the other one which we also +talked about but we didn't talk about + + align:start position:0% +talked about but we didn't talk about + + + align:start position:0% +talked about but we didn't talk about +the chemistry and the Carroll paper was + + align:start position:0% +the chemistry and the Carroll paper was + + + align:start position:0% +the chemistry and the Carroll paper was +peroxy redox ins and there are like + + align:start position:0% +peroxy redox ins and there are like + + + align:start position:0% +peroxy redox ins and there are like +seven or eight different isozyme so we + + align:start position:0% +seven or eight different isozyme so we + + + align:start position:0% +seven or eight different isozyme so we +have a number of ways of dealing with + + align:start position:0% +have a number of ways of dealing with + + + align:start position:0% +have a number of ways of dealing with +hydrogen peroxide + + align:start position:0% +hydrogen peroxide + + + align:start position:0% +hydrogen peroxide +again it is thermodynamically favorable + + align:start position:0% +again it is thermodynamically favorable + + + align:start position:0% +again it is thermodynamically favorable +to be an oxidant but as we've already + + align:start position:0% +to be an oxidant but as we've already + + + align:start position:0% +to be an oxidant but as we've already +talked about before hydrogen peroxide is + + align:start position:0% +talked about before hydrogen peroxide is + + + align:start position:0% +talked about before hydrogen peroxide is +really not very chemically reactive at + + align:start position:0% +really not very chemically reactive at + + + align:start position:0% +really not very chemically reactive at +all and so the numbers that they quote + + align:start position:0% +all and so the numbers that they quote + + + align:start position:0% +all and so the numbers that they quote +under these sets of conditions are 0.9 + + align:start position:0% +under these sets of conditions are 0.9 + + + align:start position:0% +under these sets of conditions are 0.9 +per molar per second so it's much much + + align:start position:0% +per molar per second so it's much much + + + align:start position:0% +per molar per second so it's much much +slower you see numbers that range from + + align:start position:0% +slower you see numbers that range from + + + align:start position:0% +slower you see numbers that range from +0.9 to 20 but this has really important + + align:start position:0% +0.9 to 20 but this has really important + + + align:start position:0% +0.9 to 20 but this has really important +implications in the paper we talked + + align:start position:0% +implications in the paper we talked + + + align:start position:0% +implications in the paper we talked +about in the mass spec analysis where + + align:start position:0% +about in the mass spec analysis where + + + align:start position:0% +about in the mass spec analysis where +hydrogen peroxide is functioning as a + + align:start position:0% +hydrogen peroxide is functioning as a + + + align:start position:0% +hydrogen peroxide is functioning as a +signaling agent we're going to come back + + align:start position:0% +signaling agent we're going to come back + + + align:start position:0% +signaling agent we're going to come back +to this later on and this few years made + + align:start position:0% +to this later on and this few years made + + + align:start position:0% +to this later on and this few years made +chemical more chemically tight people + + align:start position:0% +chemical more chemically tight people + + + align:start position:0% +chemical more chemically tight people +not believe that hydrogen peroxide was + + align:start position:0% +not believe that hydrogen peroxide was + + + align:start position:0% +not believe that hydrogen peroxide was +involved in signaling because the rate + + align:start position:0% +involved in signaling because the rate + + + align:start position:0% +involved in signaling because the rate +constants were just too slow compared to + + align:start position:0% +constants were just too slow compared to + + + align:start position:0% +constants were just too slow compared to +the biological response of the other + + align:start position:0% +the biological response of the other + + + align:start position:0% +the biological response of the other +side okay so this is sort of a + + align:start position:0% +side okay so this is sort of a + + + align:start position:0% +side okay so this is sort of a +superficial overview of the differences + + align:start position:0% +superficial overview of the differences + + + align:start position:0% +superficial overview of the differences +in reactivities but the real take-home + + align:start position:0% +in reactivities but the real take-home + + + align:start position:0% +in reactivities but the real take-home +message is these molecules have + + align:start position:0% +message is these molecules have + + + align:start position:0% +message is these molecules have +different chemistry and different + + align:start position:0% +different chemistry and different + + + align:start position:0% +different chemistry and different +reactivities and i guarantee you if + + align:start position:0% +reactivities and i guarantee you if + + + align:start position:0% +reactivities and i guarantee you if +you're starting stuff inside the cell + + align:start position:0% +you're starting stuff inside the cell + + + align:start position:0% +you're starting stuff inside the cell +you're gonna worry about these kinds of + + align:start position:0% +you're gonna worry about these kinds of + + + align:start position:0% +you're gonna worry about these kinds of +things then you need to educate yourself + + align:start position:0% +things then you need to educate yourself + + + align:start position:0% +things then you need to educate yourself +about what you're worried about okay in + + align:start position:0% +about what you're worried about okay in + + + align:start position:0% +about what you're worried about okay in +terms of the redox potentials of these + + align:start position:0% +terms of the redox potentials of these + + + align:start position:0% +terms of the redox potentials of these +systems okay so there's the second way + + align:start position:0% +systems okay so there's the second way + + + align:start position:0% +systems okay so there's the second way +so those are just the redox potentials + + align:start position:0% +so those are just the redox potentials + + + align:start position:0% +so those are just the redox potentials +okay so there's a second way to look at + + align:start position:0% +okay so there's a second way to look at + + + align:start position:0% +okay so there's a second way to look at +reactivity and this is also I think in + + align:start position:0% +reactivity and this is also I think in + + + align:start position:0% +reactivity and this is also I think in +the paper you had a read so the second + + align:start position:0% +the paper you had a read so the second + + + align:start position:0% +the paper you had a read so the second +way is by just + + align:start position:0% +way is by just + + + align:start position:0% +way is by just +looking at diffusion how far this is + + align:start position:0% +looking at diffusion how far this is + + + align:start position:0% +looking at diffusion how far this is +within a cell can you still feel the + + align:start position:0% +within a cell can you still feel the + + + align:start position:0% +within a cell can you still feel the +effects of the oxidant okay and so I'm + + align:start position:0% +effects of the oxidant okay and so I'm + + + align:start position:0% +effects of the oxidant okay and so I'm +going to say see PowerPoint for the + + align:start position:0% +going to say see PowerPoint for the + + + align:start position:0% +going to say see PowerPoint for the +cartoon okay so I think this is good way + + align:start position:0% +cartoon okay so I think this is good way + + + align:start position:0% +cartoon okay so I think this is good way +to look at this and again the numbers + + align:start position:0% +to look at this and again the numbers + + + align:start position:0% +to look at this and again the numbers +are squishy but here we are inside this + + align:start position:0% +are squishy but here we are inside this + + + align:start position:0% +are squishy but here we are inside this +is the cell and the question is do some + + align:start position:0% +is the cell and the question is do some + + + align:start position:0% +is the cell and the question is do some +of these oxidants get out of the cell + + align:start position:0% +of these oxidants get out of the cell + + + align:start position:0% +of these oxidants get out of the cell +and go to the next sets of cells okay + + align:start position:0% +and go to the next sets of cells okay + + + align:start position:0% +and go to the next sets of cells okay +and so if you look at something like + + align:start position:0% +and so if you look at something like + + + align:start position:0% +and so if you look at something like +hydra hydra hydrogen peroxide so + + align:start position:0% +hydra hydra hydrogen peroxide so + + + align:start position:0% +hydra hydra hydrogen peroxide so +hydrogen peroxide is the least reactive + + align:start position:0% +hydrogen peroxide is the least reactive + + + align:start position:0% +hydrogen peroxide is the least reactive +from this criteria of kinetically the + + align:start position:0% +from this criteria of kinetically the + + + align:start position:0% +from this criteria of kinetically the +least reactive and it goes way outside + + align:start position:0% +least reactive and it goes way outside + + + align:start position:0% +least reactive and it goes way outside +the cell okay so it diffuses farthest + + align:start position:0% +the cell okay so it diffuses farthest + + + align:start position:0% +the cell okay so it diffuses farthest +away so that means it's the least + + align:start position:0% +away so that means it's the least + + + align:start position:0% +away so that means it's the least +reactive so so the distance is used to + + align:start position:0% +reactive so so the distance is used to + + + align:start position:0% +reactive so so the distance is used to +define reactivity and again this is a + + align:start position:0% +define reactivity and again this is a + + + align:start position:0% +define reactivity and again this is a +squishy number but I think it's + + align:start position:0% +squishy number but I think it's + + + align:start position:0% +squishy number but I think it's +informative now what you see here so + + align:start position:0% +informative now what you see here so + + + align:start position:0% +informative now what you see here so +hydrogen peroxide we just went through + + align:start position:0% +hydrogen peroxide we just went through + + + align:start position:0% +hydrogen peroxide we just went through +is solis reactive but i also told you + + align:start position:0% +is solis reactive but i also told you + + + align:start position:0% +is solis reactive but i also told you +that hydrogen peroxide there are many + + align:start position:0% +that hydrogen peroxide there are many + + + align:start position:0% +that hydrogen peroxide there are many +ways to remove it inside the cell + + align:start position:0% +ways to remove it inside the cell + + + align:start position:0% +ways to remove it inside the cell +peroxiredoxin is glutathione g + + align:start position:0% +peroxiredoxin is glutathione g + + + align:start position:0% +peroxiredoxin is glutathione g +glutathione peroxidase as catalyzes they + + align:start position:0% +glutathione peroxidase as catalyzes they + + + align:start position:0% +glutathione peroxidase as catalyzes they +all remove it they all have different + + align:start position:0% +all remove it they all have different + + + align:start position:0% +all remove it they all have different +rate constants paroxetine redox ins + + align:start position:0% +rate constants paroxetine redox ins + + + align:start position:0% +rate constants paroxetine redox ins +account for I think it's 1.5% of + + align:start position:0% +account for I think it's 1.5% of + + + align:start position:0% +account for I think it's 1.5% of +mammalian cells and they're very + + align:start position:0% +mammalian cells and they're very + + + align:start position:0% +mammalian cells and they're very +important in controlling redox balance + + align:start position:0% +important in controlling redox balance + + + align:start position:0% +important in controlling redox balance +and what do you see here if you are in + + align:start position:0% +and what do you see here if you are in + + + align:start position:0% +and what do you see here if you are in +an environment where you have a peroxide + + align:start position:0% +an environment where you have a peroxide + + + align:start position:0% +an environment where you have a peroxide +or redox in what happens this diffuses a + + align:start position:0% +or redox in what happens this diffuses a + + + align:start position:0% +or redox in what happens this diffuses a +lot less quickly why be + + align:start position:0% +lot less quickly why be + + + align:start position:0% +lot less quickly why be +the enzyme rapidly reacts with this + + align:start position:0% +the enzyme rapidly reacts with this + + + align:start position:0% +the enzyme rapidly reacts with this +molecule so we know that the enzyme can + + align:start position:0% +molecule so we know that the enzyme can + + + align:start position:0% +molecule so we know that the enzyme can +react I haven't given you that number + + align:start position:0% +react I haven't given you that number + + + align:start position:0% +react I haven't given you that number +but we'll see that this number is on + + align:start position:0% +but we'll see that this number is on + + + align:start position:0% +but we'll see that this number is on +instead of being a number of 0.9 to 20 + + align:start position:0% +instead of being a number of 0.9 to 20 + + + align:start position:0% +instead of being a number of 0.9 to 20 +is going to be 10 to the 6 per molar per + + align:start position:0% +is going to be 10 to the 6 per molar per + + + align:start position:0% +is going to be 10 to the 6 per molar per +second so this now something about the + + align:start position:0% +second so this now something about the + + + align:start position:0% +second so this now something about the +active site of this and it's not SH + + align:start position:0% +active site of this and it's not SH + + + align:start position:0% +active site of this and it's not SH +versus iolite we will all learn now + + align:start position:0% +versus iolite we will all learn now + + + align:start position:0% +versus iolite we will all learn now +everybody's good at this violates of the + + align:start position:0% +everybody's good at this violates of the + + + align:start position:0% +everybody's good at this violates of the +reactive species that has nothing to do + + align:start position:0% +reactive species that has nothing to do + + + align:start position:0% +reactive species that has nothing to do +with that violates are always more + + align:start position:0% +with that violates are always more + + + align:start position:0% +with that violates are always more +reactive but there's something else + + align:start position:0% +reactive but there's something else + + + align:start position:0% +reactive but there's something else +special about these proteins that allow + + align:start position:0% +special about these proteins that allow + + + align:start position:0% +special about these proteins that allow +them to control hydrogen peroxide now + + align:start position:0% +them to control hydrogen peroxide now + + + align:start position:0% +them to control hydrogen peroxide now +might why might you want to do this if + + align:start position:0% +might why might you want to do this if + + + align:start position:0% +might why might you want to do this if +you have a signaling agent like hydrogen + + align:start position:0% +you have a signaling agent like hydrogen + + + align:start position:0% +you have a signaling agent like hydrogen +peroxide you don't want it going all the + + align:start position:0% +peroxide you don't want it going all the + + + align:start position:0% +peroxide you don't want it going all the +way over here you want to control the + + align:start position:0% +way over here you want to control the + + + align:start position:0% +way over here you want to control the +effective concentration near we want the + + align:start position:0% +effective concentration near we want the + + + align:start position:0% +effective concentration near we want the +chemistry to happen so these peroxide + + align:start position:0% +chemistry to happen so these peroxide + + + align:start position:0% +chemistry to happen so these peroxide +dachshunds play an incredibly important + + align:start position:0% +dachshunds play an incredibly important + + + align:start position:0% +dachshunds play an incredibly important +role in controlling the effective + + align:start position:0% +role in controlling the effective + + + align:start position:0% +role in controlling the effective +concentrations and so if you look here + + align:start position:0% +concentrations and so if you look here + + + align:start position:0% +concentrations and so if you look here +within the cell again we're only + + align:start position:0% +within the cell again we're only + + + align:start position:0% +within the cell again we're only +focusing on oxygen but both hydroxide + + align:start position:0% +focusing on oxygen but both hydroxide + + + align:start position:0% +focusing on oxygen but both hydroxide +radical and hypochlorous acid have very + + align:start position:0% +radical and hypochlorous acid have very + + + align:start position:0% +radical and hypochlorous acid have very +are very very reactive you can't go very + + align:start position:0% +are very very reactive you can't go very + + + align:start position:0% +are very very reactive you can't go very +far without having them react with + + align:start position:0% +far without having them react with + + + align:start position:0% +far without having them react with +something and that again is consistent + + align:start position:0% +something and that again is consistent + + + align:start position:0% +something and that again is consistent +with the kinetic analyses that that + + align:start position:0% +with the kinetic analyses that that + + + align:start position:0% +with the kinetic analyses that that +people have done over the years okay so + + align:start position:0% +people have done over the years okay so + + + align:start position:0% +people have done over the years okay so +the take-home message from all of that + + align:start position:0% +the take-home message from all of that + + + align:start position:0% +the take-home message from all of that +is that these reactive oxygen species + + align:start position:0% +is that these reactive oxygen species + + + align:start position:0% +is that these reactive oxygen species +have different chemistry and different + + align:start position:0% +have different chemistry and different + + + align:start position:0% +have different chemistry and different +reactivities and you've got to educate + + align:start position:0% +reactivities and you've got to educate + + + align:start position:0% +reactivities and you've got to educate +yourself but some of these things HOCl + + align:start position:0% +yourself but some of these things HOCl + + + align:start position:0% +yourself but some of these things HOCl +and hydroxide radical are very reactive + + align:start position:0% +and hydroxide radical are very reactive + + + align:start position:0% +and hydroxide radical are very reactive +no matter what okay + + align:start position:0% +no matter what okay + + + align:start position:0% +no matter what okay +so the last thing i wanted to focus on + + align:start position:0% +so the last thing i wanted to focus on + + + align:start position:0% +so the last thing i wanted to focus on +was in this section which is basically + + align:start position:0% +was in this section which is basically + + + align:start position:0% +was in this section which is basically +the introduction + + align:start position:0% + + + + align:start position:0% + +is the defense mechanisms okay so this + + align:start position:0% +is the defense mechanisms okay so this + + + align:start position:0% +is the defense mechanisms okay so this +is the defense and I already have listed + + align:start position:0% +is the defense and I already have listed + + + align:start position:0% +is the defense and I already have listed +what the defense mechanisms are but I + + align:start position:0% +what the defense mechanisms are but I + + + align:start position:0% +what the defense mechanisms are but I +wanted to give you a few equations + + align:start position:0% +wanted to give you a few equations + + + align:start position:0% +wanted to give you a few equations +you've already seen that they can be + + align:start position:0% +you've already seen that they can be + + + align:start position:0% +you've already seen that they can be +enzymes or small molecules okay and so + + align:start position:0% +enzymes or small molecules okay and so + + + align:start position:0% +enzymes or small molecules okay and so +one example we already looked at is we + + align:start position:0% +one example we already looked at is we + + + align:start position:0% +one example we already looked at is we +already we already described but didn't + + align:start position:0% +already we already described but didn't + + + align:start position:0% +already we already described but didn't +look at in chemical details is + + align:start position:0% +look at in chemical details is + + + align:start position:0% +look at in chemical details is +superoxide dismutase okay what is + + align:start position:0% +superoxide dismutase okay what is + + + align:start position:0% +superoxide dismutase okay what is +superoxide dismutase do it takes two + + align:start position:0% +superoxide dismutase do it takes two + + + align:start position:0% +superoxide dismutase do it takes two +molecules of superoxide okay and they + + align:start position:0% +molecules of superoxide okay and they + + + align:start position:0% +molecules of superoxide okay and they +disproportionate in the presence of + + align:start position:0% +disproportionate in the presence of + + + align:start position:0% +disproportionate in the presence of +protons to hydrogen peroxide oxygen and + + align:start position:0% +protons to hydrogen peroxide oxygen and + + + align:start position:0% +protons to hydrogen peroxide oxygen and +these enzymes have a cake at over km a + + align:start position:0% +these enzymes have a cake at over km a + + + align:start position:0% +these enzymes have a cake at over km a +catalytic efficiency on the order of + + align:start position:0% +catalytic efficiency on the order of + + + align:start position:0% +catalytic efficiency on the order of +seven times 10 to the ninth per molar + + align:start position:0% +seven times 10 to the ninth per molar + + + align:start position:0% +seven times 10 to the ninth per molar +per second so these are incredibly + + align:start position:0% +per second so these are incredibly + + + align:start position:0% +per second so these are incredibly +efficient in fact metals again manganese + + align:start position:0% +efficient in fact metals again manganese + + + align:start position:0% +efficient in fact metals again manganese +in solution in some organisms they have + + align:start position:0% +in solution in some organisms they have + + + align:start position:0% +in solution in some organisms they have +a lot of manganese they can actually do + + align:start position:0% +a lot of manganese they can actually do + + + align:start position:0% +a lot of manganese they can actually do +just proportionate but it's all about + + align:start position:0% +just proportionate but it's all about + + + align:start position:0% +just proportionate but it's all about +the rate constants okay so this is + + align:start position:0% +the rate constants okay so this is + + + align:start position:0% +the rate constants okay so this is +incredibly efficient these enzymes are + + align:start position:0% +incredibly efficient these enzymes are + + + align:start position:0% +incredibly efficient these enzymes are +in all organisms and so they obviously + + align:start position:0% +in all organisms and so they obviously + + + align:start position:0% +in all organisms and so they obviously +this reaction is very important so they + + align:start position:0% +this reaction is very important so they + + + align:start position:0% +this reaction is very important so they +don't want you don't want superoxide + + align:start position:0% +don't want you don't want superoxide + + + align:start position:0% +don't want you don't want superoxide +completely uncontrolled and there are + + align:start position:0% +completely uncontrolled and there are + + + align:start position:0% +completely uncontrolled and there are +some that of these enzymes these are all + + align:start position:0% +some that of these enzymes these are all + + + align:start position:0% +some that of these enzymes these are all +metal catalyzed reactions some use iron + + align:start position:0% +metal catalyzed reactions some use iron + + + align:start position:0% +metal catalyzed reactions some use iron +some use manganese some use copper some + + align:start position:0% +some use manganese some use copper some + + + align:start position:0% +some use manganese some use copper some +use human use copper and zinc and there + + align:start position:0% +use human use copper and zinc and there + + + align:start position:0% +use human use copper and zinc and there +are others that use nickel okay all have + + align:start position:0% +are others that use nickel okay all have + + + align:start position:0% +are others that use nickel okay all have +different properties and they've all + + align:start position:0% +different properties and they've all + + + align:start position:0% +different properties and they've all +been studied in some fashion so + + align:start position:0% +been studied in some fashion so + + + align:start position:0% +been studied in some fashion so +depending on where the organism lives + + align:start position:0% +depending on where the organism lives + + + align:start position:0% +depending on where the organism lives +they might use different superoxide just + + align:start position:0% +they might use different superoxide just + + + align:start position:0% +they might use different superoxide just +meet aces to control the levels of this + + align:start position:0% +meet aces to control the levels of this + + + align:start position:0% +meet aces to control the levels of this +reoxygenate + + align:start position:0% +reoxygenate + + + align:start position:0% +reoxygenate +the second defense mechanism of the + + align:start position:0% +the second defense mechanism of the + + + align:start position:0% +the second defense mechanism of the +peroxy redox ins I think I have this one + + align:start position:0% +peroxy redox ins I think I have this one + + + align:start position:0% +peroxy redox ins I think I have this one +up here okay so any of you that are + + align:start position:0% +up here okay so any of you that are + + + align:start position:0% +up here okay so any of you that are +interested in this + + align:start position:0% +interested in this + + + align:start position:0% +interested in this +they were like seven or eight isozymes + + align:start position:0% +they were like seven or eight isozymes + + + align:start position:0% +they were like seven or eight isozymes +they keep finding new isozymes they're + + align:start position:0% +they keep finding new isozymes they're + + + align:start position:0% +they keep finding new isozymes they're +everywhere inside the cell they're at + + align:start position:0% +everywhere inside the cell they're at + + + align:start position:0% +everywhere inside the cell they're at +high concentrations there and clearly + + align:start position:0% +high concentrations there and clearly + + + align:start position:0% +high concentrations there and clearly +very important and they're controlling + + align:start position:0% +very important and they're controlling + + + align:start position:0% +very important and they're controlling +the redox balance okay so they do react + + align:start position:0% +the redox balance okay so they do react + + + align:start position:0% +the redox balance okay so they do react +with hydrogen peroxide but they also + + align:start position:0% +with hydrogen peroxide but they also + + + align:start position:0% +with hydrogen peroxide but they also +react with other peroxides and they're + + align:start position:0% +react with other peroxides and they're + + + align:start position:0% +react with other peroxides and they're +controlling the redox they're important + + align:start position:0% +controlling the redox they're important + + + align:start position:0% +controlling the redox they're important +in controlling the redox balance okay + + align:start position:0% +in controlling the redox balance okay + + + align:start position:0% +in controlling the redox balance okay +and so here and in each one of these + + align:start position:0% +and so here and in each one of these + + + align:start position:0% +and so here and in each one of these +isozymes has its own characteristics + + align:start position:0% +isozymes has its own characteristics + + + align:start position:0% +isozymes has its own characteristics +okay and i don't you don't need to + + align:start position:0% +okay and i don't you don't need to + + + align:start position:0% +okay and i don't you don't need to +remember the details but the chemical + + align:start position:0% +remember the details but the chemical + + + align:start position:0% +remember the details but the chemical +mechanisms are sort of the same even + + align:start position:0% +mechanisms are sort of the same even + + + align:start position:0% +mechanisms are sort of the same even +though some are dimers some are monomers + + align:start position:0% +though some are dimers some are monomers + + + align:start position:0% +though some are dimers some are monomers +it turns out they all have in the + + align:start position:0% +it turns out they all have in the + + + align:start position:0% +it turns out they all have in the +monomer two reactive cystines okay so + + align:start position:0% +monomer two reactive cystines okay so + + + align:start position:0% +monomer two reactive cystines okay so +one is called CP that means that's the + + align:start position:0% +one is called CP that means that's the + + + align:start position:0% +one is called CP that means that's the +species that reacts with the hydrogen + + align:start position:0% +species that reacts with the hydrogen + + + align:start position:0% +species that reacts with the hydrogen +peroxide so we have they can be monomers + + align:start position:0% +peroxide so we have they can be monomers + + + align:start position:0% +peroxide so we have they can be monomers +or dimers this is the protein and so you + + align:start position:0% +or dimers this is the protein and so you + + + align:start position:0% +or dimers this is the protein and so you +could have a CP which can react to get + + align:start position:0% +could have a CP which can react to get + + + align:start position:0% +could have a CP which can react to get +self-immolated and then you have a CR + + align:start position:0% +self-immolated and then you have a CR + + + align:start position:0% +self-immolated and then you have a CR +which can react to resolve the + + align:start position:0% +which can react to resolve the + + + align:start position:0% +which can react to resolve the +self-immolation process so you're gonna + + align:start position:0% +self-immolation process so you're gonna + + + align:start position:0% +self-immolation process so you're gonna +get rid of the self enoch acid so here + + align:start position:0% +get rid of the self enoch acid so here + + + align:start position:0% +get rid of the self enoch acid so here +if you have a CR I'm being sloppy here + + align:start position:0% +if you have a CR I'm being sloppy here + + + align:start position:0% +if you have a CR I'm being sloppy here +in other words you probably have this is + + align:start position:0% +in other words you probably have this is + + + align:start position:0% +in other words you probably have this is +probably protonated it's all controlled + + align:start position:0% +probably protonated it's all controlled + + + align:start position:0% +probably protonated it's all controlled +to generate the anionic form of the file + + align:start position:0% +to generate the anionic form of the file + + + align:start position:0% +to generate the anionic form of the file +which then can form in this case I'm + + align:start position:0% +which then can form in this case I'm + + + align:start position:0% +which then can form in this case I'm +drawing an intramolecular disulfide okay + + align:start position:0% +drawing an intramolecular disulfide okay + + + align:start position:0% +drawing an intramolecular disulfide okay +so this forms a disulfide + + align:start position:0% + + + + align:start position:0% + +okay and this is intra-molecular okay so + + align:start position:0% +okay and this is intra-molecular okay so + + + align:start position:0% +okay and this is intra-molecular okay so +what if we what do we see over here over + + align:start position:0% +what if we what do we see over here over + + + align:start position:0% +what if we what do we see over here over +here we see you can form an in term + + align:start position:0% +here we see you can form an in term + + + align:start position:0% +here we see you can form an in term +molecular disulfide if the molecule is a + + align:start position:0% +molecular disulfide if the molecule is a + + + align:start position:0% +molecular disulfide if the molecule is a +dimer okay so the chemistry is exactly + + align:start position:0% +dimer okay so the chemistry is exactly + + + align:start position:0% +dimer okay so the chemistry is exactly +the same but sometimes it occurs through + + align:start position:0% +the same but sometimes it occurs through + + + align:start position:0% +the same but sometimes it occurs through +the monomer sometimes it occurs through + + align:start position:0% +the monomer sometimes it occurs through + + + align:start position:0% +the monomer sometimes it occurs through +the dimer okay and then the question is + + align:start position:0% +the dimer okay and then the question is + + + align:start position:0% +the dimer okay and then the question is +once you have the disulfide so now you + + align:start position:0% +once you have the disulfide so now you + + + align:start position:0% +once you have the disulfide so now you +have how do you reduce this and yuuri + + align:start position:0% +have how do you reduce this and yuuri + + + align:start position:0% +have how do you reduce this and yuuri +reduce this by some kind of reductant + + align:start position:0% +reduce this by some kind of reductant + + + align:start position:0% +reduce this by some kind of reductant +less such as saira dachshund which we + + align:start position:0% +less such as saira dachshund which we + + + align:start position:0% +less such as saira dachshund which we +will see if we get as far as talking + + align:start position:0% +will see if we get as far as talking + + + align:start position:0% +will see if we get as far as talking +about ribonucleotide reductase so where + + align:start position:0% +about ribonucleotide reductase so where + + + align:start position:0% +about ribonucleotide reductase so where +have you seen these kinds of proteins + + align:start position:0% +have you seen these kinds of proteins + + + align:start position:0% +have you seen these kinds of proteins +before does anybody remember + + align:start position:0% +before does anybody remember + + + align:start position:0% +before does anybody remember +so thyroid Roxon let me this is fiyo + + align:start position:0% +so thyroid Roxon let me this is fiyo + + + align:start position:0% +so thyroid Roxon let me this is fiyo +Reid oxen there are probably ten + + align:start position:0% +Reid oxen there are probably ten + + + align:start position:0% +Reid oxen there are probably ten +different kinds of thyroid auxins inside + + align:start position:0% +different kinds of thyroid auxins inside + + + align:start position:0% +different kinds of thyroid auxins inside +the cell via small little proteins as is + + align:start position:0% +the cell via small little proteins as is + + + align:start position:0% +the cell via small little proteins as is +peroxy redox ins and they're all + + align:start position:0% +peroxy redox ins and they're all + + + align:start position:0% +peroxy redox ins and they're all +involved really in redox balance okay so + + align:start position:0% +involved really in redox balance okay so + + + align:start position:0% +involved really in redox balance okay so +we can intercept the hydrogen peroxide + + align:start position:0% +we can intercept the hydrogen peroxide + + + align:start position:0% +we can intercept the hydrogen peroxide +say we want to get rid of the hydrogen + + align:start position:0% +say we want to get rid of the hydrogen + + + align:start position:0% +say we want to get rid of the hydrogen +peroxide fast okay we've done our + + align:start position:0% +peroxide fast okay we've done our + + + align:start position:0% +peroxide fast okay we've done our +signaling we want to get rid of it you + + align:start position:0% +signaling we want to get rid of it you + + + align:start position:0% +signaling we want to get rid of it you +need to get something in there that can + + align:start position:0% +need to get something in there that can + + + align:start position:0% +need to get something in there that can +react where the hydrogen peroxide is + + align:start position:0% +react where the hydrogen peroxide is + + + align:start position:0% +react where the hydrogen peroxide is +they are fast to remove it and then you + + align:start position:0% +they are fast to remove it and then you + + + align:start position:0% +they are fast to remove it and then you +want to reset your protein so it can + + align:start position:0% +want to reset your protein so it can + + + align:start position:0% +want to reset your protein so it can +react with another molecule so you need + + align:start position:0% +react with another molecule so you need + + + align:start position:0% +react with another molecule so you need +a reductant okay so these are the key + + align:start position:0% +a reductant okay so these are the key + + + align:start position:0% +a reductant okay so these are the key +for two of the two of the four things I + + align:start position:0% +for two of the two of the four things I + + + align:start position:0% +for two of the two of the four things I +was gonna describe in terms a defense + + align:start position:0% +was gonna describe in terms a defense + + + align:start position:0% +was gonna describe in terms a defense +another one is catalase this is the one + + align:start position:0% +another one is catalase this is the one + + + align:start position:0% +another one is catalase this is the one +that if you go back and you look at the + + align:start position:0% +that if you go back and you look at the + + + align:start position:0% +that if you go back and you look at the +Carroll paper which we discussed + + align:start position:0% +Carroll paper which we discussed + + + align:start position:0% +Carroll paper which we discussed +actually in class + + align:start position:0% +actually in class + + + align:start position:0% +actually in class +these Maalik these are heme proteins and + + align:start position:0% +these Maalik these are heme proteins and + + + align:start position:0% +these Maalik these are heme proteins and +these are distinct from the milo + + align:start position:0% +these are distinct from the milo + + + align:start position:0% +these are distinct from the milo +peroxidase that we'll talk about in this + + align:start position:0% +peroxidase that we'll talk about in this + + + align:start position:0% +peroxidase that we'll talk about in this +section + + align:start position:0% +section + + + align:start position:0% +section +but they can take hydrogen peroxide and + + align:start position:0% +but they can take hydrogen peroxide and + + + align:start position:0% +but they can take hydrogen peroxide and +they can convert it to oxygen plus water + + align:start position:0% +they can convert it to oxygen plus water + + + align:start position:0% +they can convert it to oxygen plus water +so what they've done is removed a + + align:start position:0% +so what they've done is removed a + + + align:start position:0% +so what they've done is removed a +putative reactive species again how + + align:start position:0% +putative reactive species again how + + + align:start position:0% +putative reactive species again how +reactive it is depends on the + + align:start position:0% +reactive it is depends on the + + + align:start position:0% +reactive it is depends on the +environment and turn it back into oxygen + + align:start position:0% +environment and turn it back into oxygen + + + align:start position:0% +environment and turn it back into oxygen +water which are completely unreactive + + align:start position:0% +water which are completely unreactive + + + align:start position:0% +water which are completely unreactive +okay and the fourth which is used quite + + align:start position:0% +okay and the fourth which is used quite + + + align:start position:0% +okay and the fourth which is used quite +frequently are the glutathione + + align:start position:0% +frequently are the glutathione + + + align:start position:0% +frequently are the glutathione +peroxidase is okay and this is the one I + + align:start position:0% + + + + align:start position:0% + +just talked code you what the structure + + align:start position:0% +just talked code you what the structure + + + align:start position:0% +just talked code you what the structure +of glutathione is peroxidases + + align:start position:0% +of glutathione is peroxidases + + + align:start position:0% +of glutathione is peroxidases +you all know from the Carroll paper that + + align:start position:0% +you all know from the Carroll paper that + + + align:start position:0% +you all know from the Carroll paper that +you have a single reactive cysteine and + + align:start position:0% +you have a single reactive cysteine and + + + align:start position:0% +you have a single reactive cysteine and +glutathione peroxidase 3 that's what we + + align:start position:0% +glutathione peroxidase 3 that's what we + + + align:start position:0% +glutathione peroxidase 3 that's what we +used as the model for all of our redox + + align:start position:0% +used as the model for all of our redox + + + align:start position:0% +used as the model for all of our redox +chemistry some of the glutathione + + align:start position:0% +chemistry some of the glutathione + + + align:start position:0% +chemistry some of the glutathione +peroxidase is actually you selenium so + + align:start position:0% +peroxidase is actually you selenium so + + + align:start position:0% +peroxidase is actually you selenium so +this is a twenty second amino acid it is + + align:start position:0% +this is a twenty second amino acid it is + + + align:start position:0% +this is a twenty second amino acid it is +Celaeno cysteine okay this is one of the + + align:start position:0% +Celaeno cysteine okay this is one of the + + + align:start position:0% +Celaeno cysteine okay this is one of the +few enzymes as our thyroid ox and + + align:start position:0% +few enzymes as our thyroid ox and + + + align:start position:0% +few enzymes as our thyroid ox and +reductases which are involved in this + + align:start position:0% +reductases which are involved in this + + + align:start position:0% +reductases which are involved in this +whole redox balance system are selling + + align:start position:0% +whole redox balance system are selling + + + align:start position:0% +whole redox balance system are selling +out proteins okay we're not going to + + align:start position:0% +out proteins okay we're not going to + + + align:start position:0% +out proteins okay we're not going to +talk about those but the glutathione + + align:start position:0% +talk about those but the glutathione + + + align:start position:0% +talk about those but the glutathione +peroxidase is actually take two + + align:start position:0% +peroxidase is actually take two + + + align:start position:0% +peroxidase is actually take two +molecules of glutathione plus hydrogen + + align:start position:0% +molecules of glutathione plus hydrogen + + + align:start position:0% +molecules of glutathione plus hydrogen +peroxide again there are many many + + align:start position:0% +peroxide again there are many many + + + align:start position:0% +peroxide again there are many many +isozymes + + align:start position:0% +isozymes + + + align:start position:0% +isozymes +and they can oxidize this to the + + align:start position:0% +and they can oxidize this to the + + + align:start position:0% +and they can oxidize this to the +oxidized form so this is the reduced + + align:start position:0% +oxidized form so this is the reduced + + + align:start position:0% +oxidized form so this is the reduced +form you have a cysteine and this is the + + align:start position:0% +form you have a cysteine and this is the + + + align:start position:0% +form you have a cysteine and this is the +oxidized form so you have a disulfide + + align:start position:0% +oxidized form so you have a disulfide + + + align:start position:0% +oxidized form so you have a disulfide +okay now again where have you seen this + + align:start position:0% +okay now again where have you seen this + + + align:start position:0% +okay now again where have you seen this +style disulfide system before I mean + + align:start position:0% +style disulfide system before I mean + + + align:start position:0% +style disulfide system before I mean +bacteria have these things we're talking + + align:start position:0% +bacteria have these things we're talking + + + align:start position:0% +bacteria have these things we're talking +now we're focused on human systems do + + align:start position:0% +now we're focused on human systems do + + + align:start position:0% +now we're focused on human systems do +you remember what happens in the + + align:start position:0% +you remember what happens in the + + + align:start position:0% +you remember what happens in the +periplasmic bacteria do you remember did + + align:start position:0% +periplasmic bacteria do you remember did + + + align:start position:0% +periplasmic bacteria do you remember did +you talk about that this year okay so + + align:start position:0% +you talk about that this year okay so + + + align:start position:0% +you talk about that this year okay so +you haven't seen this before in past so + + align:start position:0% +you haven't seen this before in past so + + + align:start position:0% +you haven't seen this before in past so +bacteria up in there periplasm + + align:start position:0% +bacteria up in there periplasm + + + align:start position:0% +bacteria up in there periplasm +enzymes that control what thiols you + + align:start position:0% +enzymes that control what thiols you + + + align:start position:0% +enzymes that control what thiols you +have + + align:start position:0% +have + + + align:start position:0% +have +and the states of the file so the this + + align:start position:0% +and the states of the file so the this + + + align:start position:0% +and the states of the file so the this +redox balance by this disulfide + + align:start position:0% +redox balance by this disulfide + + + align:start position:0% +redox balance by this disulfide +interchange very similar to this kind of + + align:start position:0% +interchange very similar to this kind of + + + align:start position:0% +interchange very similar to this kind of +chemistry is everywhere okay and the + + align:start position:0% +chemistry is everywhere okay and the + + + align:start position:0% +chemistry is everywhere okay and the +chemistry is pretty simple but if you go + + align:start position:0% +chemistry is pretty simple but if you go + + + align:start position:0% +chemistry is pretty simple but if you go +from cysteine okay to a disulfide you + + align:start position:0% +from cysteine okay to a disulfide you + + + align:start position:0% +from cysteine okay to a disulfide you +just don't go there that you just don't + + align:start position:0% +just don't go there that you just don't + + + align:start position:0% +just don't go there that you just don't +go there with the oxygen I think this is + + align:start position:0% +go there with the oxygen I think this is + + + align:start position:0% +go there with the oxygen I think this is +something that people get confused about + + align:start position:0% +something that people get confused about + + + align:start position:0% +something that people get confused about +all the time something you're doing an + + align:start position:0% +all the time something you're doing an + + + align:start position:0% +all the time something you're doing an +oxidation something has to be reduced + + align:start position:0% +oxidation something has to be reduced + + + align:start position:0% +oxidation something has to be reduced +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so you know hydrogen peroxide is a guy + + align:start position:0% +so you know hydrogen peroxide is a guy + + + align:start position:0% +so you know hydrogen peroxide is a guy +to go through sulfenic acid you can now + + align:start position:0% +to go through sulfenic acid you can now + + + align:start position:0% +to go through sulfenic acid you can now +picture that you can have general acid + + align:start position:0% +picture that you can have general acid + + + align:start position:0% +picture that you can have general acid +catalyzed general base catalyzed + + align:start position:0% +catalyzed general base catalyzed + + + align:start position:0% +catalyzed general base catalyzed +cleavage of disulfide bond formation so + + align:start position:0% +cleavage of disulfide bond formation so + + + align:start position:0% +cleavage of disulfide bond formation so +just because you have oxygen around and + + align:start position:0% +just because you have oxygen around and + + + align:start position:0% +just because you have oxygen around and +reduced cysteines around don't doesn't + + align:start position:0% +reduced cysteines around don't doesn't + + + align:start position:0% +reduced cysteines around don't doesn't +mean you automatically rapidly have + + align:start position:0% +mean you automatically rapidly have + + + align:start position:0% +mean you automatically rapidly have +disulfides around again you need to + + align:start position:0% +disulfides around again you need to + + + align:start position:0% +disulfides around again you need to +think about the chemistry of what's + + align:start position:0% +think about the chemistry of what's + + + align:start position:0% +think about the chemistry of what's +going on okay so so now what i want to + + align:start position:0% +going on okay so so now what i want to + + + align:start position:0% +going on okay so so now what i want to +do is then show you sort of the general + + align:start position:0% +do is then show you sort of the general + + + align:start position:0% +do is then show you sort of the general +model and then we'll talk about the + + align:start position:0% +model and then we'll talk about the + + + align:start position:0% +model and then we'll talk about the +NADPH oxidase which is the focus of + + align:start position:0% +NADPH oxidase which is the focus of + + + align:start position:0% +NADPH oxidase which is the focus of +module seven so so we're gonna the + + align:start position:0% +module seven so so we're gonna the + + + align:start position:0% +module seven so so we're gonna the +general model is as follows so you have + + align:start position:0% +general model is as follows so you have + + + align:start position:0% +general model is as follows so you have +an oxygen and we have the end we have + + align:start position:0% +an oxygen and we have the end we have + + + align:start position:0% +an oxygen and we have the end we have +this um sorry the proteins we're gonna + + align:start position:0% +this um sorry the proteins we're gonna + + + align:start position:0% +this um sorry the proteins we're gonna +be talking about or NOx to or another + + align:start position:0% +be talking about or NOx to or another + + + align:start position:0% +be talking about or NOx to or another +NOx Isis I'm okay I'm not gonna write + + align:start position:0% +NOx Isis I'm okay I'm not gonna write + + + align:start position:0% +NOx Isis I'm okay I'm not gonna write +out the name we talked about that in the + + align:start position:0% +out the name we talked about that in the + + + align:start position:0% +out the name we talked about that in the +last recitation section this these + + align:start position:0% +last recitation section this these + + + align:start position:0% +last recitation section this these +enzymes use and I think this is + + align:start position:0% +enzymes use and I think this is + + + align:start position:0% +enzymes use and I think this is +important because part of the redox + + align:start position:0% +important because part of the redox + + + align:start position:0% +important because part of the redox +switches that I think are + + align:start position:0% +switches that I think are + + + align:start position:0% +switches that I think are +underappreciated of the levels of NADPH + + align:start position:0% +underappreciated of the levels of NADPH + + + align:start position:0% +underappreciated of the levels of NADPH +and ATP they play incredibly important + + align:start position:0% +and ATP they play incredibly important + + + align:start position:0% +and ATP they play incredibly important +roles inside the cell so you have any d + + align:start position:0% +roles inside the cell so you have any d + + + align:start position:0% +roles inside the cell so you have any d +pH going to any D P okay and we talked + + align:start position:0% +pH going to any D P okay and we talked + + + align:start position:0% +pH going to any D P okay and we talked +about the fact and we'll come back to + + align:start position:0% +about the fact and we'll come back to + + + align:start position:0% +about the fact and we'll come back to +this that this protein has a flavin and + + align:start position:0% +this that this protein has a flavin and + + + align:start position:0% +this that this protein has a flavin and +two heme okay and it produces superoxide + + align:start position:0% +two heme okay and it produces superoxide + + + align:start position:0% +two heme okay and it produces superoxide +okay so this is incredibly unusual + + align:start position:0% +okay so this is incredibly unusual + + + align:start position:0% +okay so this is incredibly unusual +superoxide is usually an artifact of + + align:start position:0% +superoxide is usually an artifact of + + + align:start position:0% +superoxide is usually an artifact of +some uncoupling reaction that happens + + align:start position:0% +some uncoupling reaction that happens + + + align:start position:0% +some uncoupling reaction that happens +all the time inside the cell this enzyme + + align:start position:0% +all the time inside the cell this enzyme + + + align:start position:0% +all the time inside the cell this enzyme +is a proffesional superoxide generator + + align:start position:0% +is a proffesional superoxide generator + + + align:start position:0% +is a proffesional superoxide generator +that's what its goal is okay most other + + align:start position:0% +that's what its goal is okay most other + + + align:start position:0% +that's what its goal is okay most other +times you see superoxide something has + + align:start position:0% +times you see superoxide something has + + + align:start position:0% +times you see superoxide something has +gone astray so this is a proffesional + + align:start position:0% + + + + align:start position:0% + +superoxide generator and so what happens + + align:start position:0% +superoxide generator and so what happens + + + align:start position:0% +superoxide generator and so what happens +then when you generate superoxide you + + align:start position:0% +then when you generate superoxide you + + + align:start position:0% +then when you generate superoxide you +can have s OD or you can have protons so + + align:start position:0% +can have s OD or you can have protons so + + + align:start position:0% +can have s OD or you can have protons so +if you're in a place where the pH is + + align:start position:0% +if you're in a place where the pH is + + + align:start position:0% +if you're in a place where the pH is +slightly lower you generate rapidly very + + align:start position:0% +slightly lower you generate rapidly very + + + align:start position:0% +slightly lower you generate rapidly very +rapidly hydrogen peroxide okay so + + align:start position:0% +rapidly hydrogen peroxide okay so + + + align:start position:0% +rapidly hydrogen peroxide okay so +superoxide doesn't sit around all that + + align:start position:0% +superoxide doesn't sit around all that + + + align:start position:0% +superoxide doesn't sit around all that +long if you have iron 3 around could be + + align:start position:0% +long if you have iron 3 around could be + + + align:start position:0% +long if you have iron 3 around could be +bound to something what happens is the + + align:start position:0% +bound to something what happens is the + + + align:start position:0% +bound to something what happens is the +superoxide combines with the iron 3 to + + align:start position:0% +superoxide combines with the iron 3 to + + + align:start position:0% +superoxide combines with the iron 3 to +reduce it to iron - okay plus oxygen so + + align:start position:0% +reduce it to iron - okay plus oxygen so + + + align:start position:0% +reduce it to iron - okay plus oxygen so +superoxide if you look at the reduction + + align:start position:0% +superoxide if you look at the reduction + + + align:start position:0% +superoxide if you look at the reduction +potentials obviously what does it depend + + align:start position:0% +potentials obviously what does it depend + + + align:start position:0% +potentials obviously what does it depend +on it depends on the ligand environment + + align:start position:0% +on it depends on the ligand environment + + + align:start position:0% +on it depends on the ligand environment +of the iron 3 that affects the redox + + align:start position:0% +of the iron 3 that affects the redox + + + align:start position:0% +of the iron 3 that affects the redox +potential hopefully you all know that + + align:start position:0% +potential hopefully you all know that + + + align:start position:0% +potential hopefully you all know that +and have thought about that at this + + align:start position:0% +and have thought about that at this + + + align:start position:0% +and have thought about that at this +stage given the last module so what + + align:start position:0% +stage given the last module so what + + + align:start position:0% +stage given the last module so what +happens now is the hydrogen peroxide can + + align:start position:0% +happens now is the hydrogen peroxide can + + + align:start position:0% +happens now is the hydrogen peroxide can +react with iron 2 and this is the killer + + align:start position:0% +react with iron 2 and this is the killer + + + align:start position:0% +react with iron 2 and this is the killer +that does what's called fentons + + align:start position:0% +that does what's called fentons + + + align:start position:0% +that does what's called fentons +chemistry which generates hydroxide + + align:start position:0% +chemistry which generates hydroxide + + + align:start position:0% +chemistry which generates hydroxide +radical ok so these two guys hydrogen + + align:start position:0% +radical ok so these two guys hydrogen + + + align:start position:0% +radical ok so these two guys hydrogen +peroxide and iron now combined by what + + align:start position:0% +peroxide and iron now combined by what + + + align:start position:0% +peroxide and iron now combined by what +is called in the Revue fentons chemistry + + align:start position:0% +is called in the Revue fentons chemistry + + + align:start position:0% +is called in the Revue fentons chemistry +and i'm not going to write out the + + align:start position:0% +and i'm not going to write out the + + + align:start position:0% +and i'm not going to write out the +detailed mechanism of how this works in + + align:start position:0% +detailed mechanism of how this works in + + + align:start position:0% +detailed mechanism of how this works in +fact + + align:start position:0% +fact + + + align:start position:0% +fact +I think we still really don't completely + + align:start position:0% +I think we still really don't completely + + + align:start position:0% +I think we still really don't completely +understand it but anyhow you're + + align:start position:0% +understand it but anyhow you're + + + align:start position:0% +understand it but anyhow you're +generating this reactive species + + align:start position:0% +generating this reactive species + + + align:start position:0% +generating this reactive species +hydroxide radical which is dying to be + + align:start position:0% +hydroxide radical which is dying to be + + + align:start position:0% +hydroxide radical which is dying to be +reduced okay so this guy is responsible + + align:start position:0% +reduced okay so this guy is responsible + + + align:start position:0% +reduced okay so this guy is responsible +hits anything and it reacts so it + + align:start position:0% +hits anything and it reacts so it + + + align:start position:0% +hits anything and it reacts so it +ultimately is responsible for modifying + + align:start position:0% +ultimately is responsible for modifying + + + align:start position:0% +ultimately is responsible for modifying +lipids modifying sugars modifying amino + + align:start position:0% +lipids modifying sugars modifying amino + + + align:start position:0% +lipids modifying sugars modifying amino +acids modifying nucleic acid this guy + + align:start position:0% +acids modifying nucleic acid this guy + + + align:start position:0% +acids modifying nucleic acid this guy +it's because it's so reactive damages + + align:start position:0% +it's because it's so reactive damages + + + align:start position:0% +it's because it's so reactive damages +proteins DNA RNA I'm not gonna write all + + align:start position:0% +proteins DNA RNA I'm not gonna write all + + + align:start position:0% +proteins DNA RNA I'm not gonna write all +this out lipids this is a guy okay and + + align:start position:0% +this out lipids this is a guy okay and + + + align:start position:0% +this out lipids this is a guy okay and +that's described in the review article + + align:start position:0% +that's described in the review article + + + align:start position:0% +that's described in the review article +you had to read and what can this + + align:start position:0% +you had to read and what can this + + + align:start position:0% +you had to read and what can this +hydrogen peroxide also do we'll also see + + align:start position:0% +hydrogen peroxide also do we'll also see + + + align:start position:0% +hydrogen peroxide also do we'll also see +that the hydrogen peroxide which is + + align:start position:0% +that the hydrogen peroxide which is + + + align:start position:0% +that the hydrogen peroxide which is +going to be generated inside the + + align:start position:0% +going to be generated inside the + + + align:start position:0% +going to be generated inside the +neutrophil which we're going to be + + align:start position:0% +neutrophil which we're going to be + + + align:start position:0% +neutrophil which we're going to be +focusing on the white blood cells that + + align:start position:0% +focusing on the white blood cells that + + + align:start position:0% +focusing on the white blood cells that +are going to be trying to take care of + + align:start position:0% +are going to be trying to take care of + + + align:start position:0% +are going to be trying to take care of +the bacteria or viruses and that you + + align:start position:0% +the bacteria or viruses and that you + + + align:start position:0% +the bacteria or viruses and that you +have chloride now you form hypochlorous + + align:start position:0% +have chloride now you form hypochlorous + + + align:start position:0% +have chloride now you form hypochlorous +acid okay so so these are the kinds of + + align:start position:0% +acid okay so so these are the kinds of + + + align:start position:0% +acid okay so so these are the kinds of +guys h o dot h o CL are guys that are + + align:start position:0% +guys h o dot h o CL are guys that are + + + align:start position:0% +guys h o dot h o CL are guys that are +going to actually do make do destructive + + align:start position:0% +going to actually do make do destructive + + + align:start position:0% +going to actually do make do destructive +things when they react with things that + + align:start position:0% +things when they react with things that + + + align:start position:0% +things when they react with things that +are help help us to defend ourselves + + align:start position:0% +are help help us to defend ourselves + + + align:start position:0% +are help help us to defend ourselves +against bacterial insults okay so that's + + align:start position:0% +against bacterial insults okay so that's + + + align:start position:0% +against bacterial insults okay so that's +a picture of the big overview okay and + + align:start position:0% +a picture of the big overview okay and + + + align:start position:0% +a picture of the big overview okay and +so that's that and we're gonna be simply + + align:start position:0% +so that's that and we're gonna be simply + + + align:start position:0% +so that's that and we're gonna be simply +focusing on two proteins the first + + align:start position:0% +focusing on two proteins the first + + + align:start position:0% +focusing on two proteins the first +protein we're going to talk about is the + + align:start position:0% +protein we're going to talk about is the + + + align:start position:0% +protein we're going to talk about is the +one we went through and recitation rocks + + align:start position:0% +one we went through and recitation rocks + + + align:start position:0% +one we went through and recitation rocks +- and i'm not gonna write down that + + align:start position:0% +- and i'm not gonna write down that + + + align:start position:0% +- and i'm not gonna write down that +reaction hopefully you all know this by + + align:start position:0% +reaction hopefully you all know this by + + + align:start position:0% +reaction hopefully you all know this by +now + + align:start position:0% +now + + + align:start position:0% +now +i just sort of said that over there and + + align:start position:0% +i just sort of said that over there and + + + align:start position:0% +i just sort of said that over there and +there are 11 different isozymes and then + + align:start position:0% +there are 11 different isozymes and then + + + align:start position:0% +there are 11 different isozymes and then +milo peroxidase which both of these are + + align:start position:0% +milo peroxidase which both of these are + + + align:start position:0% +milo peroxidase which both of these are +found in the neutrophils in the + + align:start position:0% +found in the neutrophils in the + + + align:start position:0% +found in the neutrophils in the +phagosome of the neutrophils okay + + align:start position:0% + + + + align:start position:0% + +okay so let me so the chemistry that + + align:start position:0% +okay so let me so the chemistry that + + + align:start position:0% +okay so let me so the chemistry that +goes on with the NOx proteins our + + align:start position:0% +goes on with the NOx proteins our + + + align:start position:0% +goes on with the NOx proteins our +complex is complicated so it's not just + + align:start position:0% +complex is complicated so it's not just + + + align:start position:0% +complex is complicated so it's not just +knocks the NOx protein we're going to + + align:start position:0% +knocks the NOx protein we're going to + + + align:start position:0% +knocks the NOx protein we're going to +talk about the NOx protein but as with + + align:start position:0% +talk about the NOx protein but as with + + + align:start position:0% +talk about the NOx protein but as with +everything there are other factors that + + align:start position:0% +everything there are other factors that + + + align:start position:0% +everything there are other factors that +play a key role and I'm going to show + + align:start position:0% +play a key role and I'm going to show + + + align:start position:0% +play a key role and I'm going to show +you a cartoon with what the other + + align:start position:0% +you a cartoon with what the other + + + align:start position:0% +you a cartoon with what the other +factors are but we're not going to talk + + align:start position:0% +factors are but we're not going to talk + + + align:start position:0% +factors are but we're not going to talk +about the details of how those factors + + align:start position:0% +about the details of how those factors + + + align:start position:0% +about the details of how those factors +help the NOx to protein make superoxide + + align:start position:0% +help the NOx to protein make superoxide + + + align:start position:0% +help the NOx to protein make superoxide +okay make superoxide in a controlled + + align:start position:0% +okay make superoxide in a controlled + + + align:start position:0% +okay make superoxide in a controlled +fashion that's the key thing in a + + align:start position:0% +fashion that's the key thing in a + + + align:start position:0% +fashion that's the key thing in a +controlled fashion so we have an ox + + align:start position:0% +controlled fashion so we have an ox + + + align:start position:0% +controlled fashion so we have an ox +protein the only one I do want to look + + align:start position:0% +protein the only one I do want to look + + + align:start position:0% +protein the only one I do want to look +at is the NOx protein itself because + + align:start position:0% +at is the NOx protein itself because + + + align:start position:0% +at is the NOx protein itself because +we're going to use it not only in in + + align:start position:0% +we're going to use it not only in in + + + align:start position:0% +we're going to use it not only in in +this lecture but also the lecture of NOx + + align:start position:0% +this lecture but also the lecture of NOx + + + align:start position:0% +this lecture but also the lecture of NOx +to proteins and signaling so the + + align:start position:0% +to proteins and signaling so the + + + align:start position:0% +to proteins and signaling so the +chemistry is the same in destroying the + + align:start position:0% +chemistry is the same in destroying the + + + align:start position:0% +chemistry is the same in destroying the +bacteria and in signaling so you need to + + align:start position:0% +bacteria and in signaling so you need to + + + align:start position:0% +bacteria and in signaling so you need to +know what the protein does so if you + + align:start position:0% +know what the protein does so if you + + + align:start position:0% +know what the protein does so if you +look at NOx to NADPH oxidase is what do + + align:start position:0% +look at NOx to NADPH oxidase is what do + + + align:start position:0% +look at NOx to NADPH oxidase is what do +you know they exist in a membrane and + + align:start position:0% +you know they exist in a membrane and + + + align:start position:0% +you know they exist in a membrane and +we'll see this membrane could be the + + align:start position:0% +we'll see this membrane could be the + + + align:start position:0% +we'll see this membrane could be the +phagosome or it can be the plasma + + align:start position:0% +phagosome or it can be the plasma + + + align:start position:0% +phagosome or it can be the plasma +membrane or it can be I'm going to show + + align:start position:0% +membrane or it can be I'm going to show + + + align:start position:0% +membrane or it can be I'm going to show +you a cartoon of this a vesicle membrane + + align:start position:0% +you a cartoon of this a vesicle membrane + + + align:start position:0% +you a cartoon of this a vesicle membrane +so they located these proteins that are + + align:start position:0% +so they located these proteins that are + + + align:start position:0% +so they located these proteins that are +located in many places inside the cell + + align:start position:0% +located in many places inside the cell + + + align:start position:0% +located in many places inside the cell +but they all sort of have the same + + align:start position:0% +but they all sort of have the same + + + align:start position:0% +but they all sort of have the same +predisposition so they have so they have + + align:start position:0% +predisposition so they have so they have + + + align:start position:0% +predisposition so they have so they have +one subunit with a domain that has the + + align:start position:0% +one subunit with a domain that has the + + + align:start position:0% +one subunit with a domain that has the +FA D on it okay so if we're looking at + + align:start position:0% +FA D on it okay so if we're looking at + + + align:start position:0% +FA D on it okay so if we're looking at +with the epidermal growth factor or if + + align:start position:0% +with the epidermal growth factor or if + + + align:start position:0% +with the epidermal growth factor or if +we're looking at the neutrophils this + + align:start position:0% +we're looking at the neutrophils this + + + align:start position:0% +we're looking at the neutrophils this +would be the cytosol if we're looking at + + align:start position:0% +would be the cytosol if we're looking at + + + align:start position:0% +would be the cytosol if we're looking at +the neutrophils and this would be the + + align:start position:0% +the neutrophils and this would be the + + + align:start position:0% +the neutrophils and this would be the +inside the lumen of the phagosome + + align:start position:0% + + + + align:start position:0% + +okay and they FA D can be or is what is + + align:start position:0% +okay and they FA D can be or is what is + + + align:start position:0% +okay and they FA D can be or is what is +the function of Fe D we've talked about + + align:start position:0% +the function of Fe D we've talked about + + + align:start position:0% +the function of Fe D we've talked about +this it's a major mediator between two + + align:start position:0% +this it's a major mediator between two + + + align:start position:0% +this it's a major mediator between two +electron chemistry and one electron + + align:start position:0% +electron chemistry and one electron + + + align:start position:0% +electron chemistry and one electron +chemistry okay and you've seen that + + align:start position:0% +chemistry okay and you've seen that + + + align:start position:0% +chemistry okay and you've seen that +before hopefully that was grilled into + + align:start position:0% +before hopefully that was grilled into + + + align:start position:0% +before hopefully that was grilled into +you in the respiratory chain so in the + + align:start position:0% +you in the respiratory chain so in the + + + align:start position:0% +you in the respiratory chain so in the +respiratory chain you have iron sulfur + + align:start position:0% +respiratory chain you have iron sulfur + + + align:start position:0% +respiratory chain you have iron sulfur +clusters or you have heenes here we're + + align:start position:0% +clusters or you have heenes here we're + + + align:start position:0% +clusters or you have heenes here we're +going to have heme and so what we have + + align:start position:0% +going to have heme and so what we have + + + align:start position:0% +going to have heme and so what we have +is on this face + + align:start position:0% +is on this face + + + align:start position:0% +is on this face +we have NADPH going to nadp+ a proton + + align:start position:0% +we have NADPH going to nadp+ a proton + + + align:start position:0% +we have NADPH going to nadp+ a proton +okay + + align:start position:0% +okay + + + align:start position:0% +okay +this turns out to be important because + + align:start position:0% +this turns out to be important because + + + align:start position:0% +this turns out to be important because +that also controls the pH and there are + + align:start position:0% +that also controls the pH and there are + + + align:start position:0% +that also controls the pH and there are +voltage channels controlled by pH that + + align:start position:0% +voltage channels controlled by pH that + + + align:start position:0% +voltage channels controlled by pH that +you need to think about if you looked at + + align:start position:0% +you need to think about if you looked at + + + align:start position:0% +you need to think about if you looked at +the detail biology and so this protein + + align:start position:0% +the detail biology and so this protein + + + align:start position:0% +the detail biology and so this protein +is GP 91 that is it's a 91 kill at + + align:start position:0% +is GP 91 that is it's a 91 kill at + + + align:start position:0% +is GP 91 that is it's a 91 kill at +Alton's and GP means it's a glycoprotein + + align:start position:0% +Alton's and GP means it's a glycoprotein + + + align:start position:0% +Alton's and GP means it's a glycoprotein +okay and then you have a second protein + + align:start position:0% +okay and then you have a second protein + + + align:start position:0% +okay and then you have a second protein +that's also an integral membrane protein + + align:start position:0% +that's also an integral membrane protein + + + align:start position:0% +that's also an integral membrane protein +that's also critical and this is GP 22 + + align:start position:0% +that's also critical and this is GP 22 + + + align:start position:0% +that's also critical and this is GP 22 +and so what you see is you have iron you + + align:start position:0% +and so what you see is you have iron you + + + align:start position:0% +and so what you see is you have iron you +have two heme cytochrome B heme + + align:start position:0% +have two heme cytochrome B heme + + + align:start position:0% +have two heme cytochrome B heme +dependent systems and these are are + + align:start position:0% +dependent systems and these are are + + + align:start position:0% +dependent systems and these are are +gonna change redox state and the + + align:start position:0% +gonna change redox state and the + + + align:start position:0% +gonna change redox state and the +interesting thing is that these two + + align:start position:0% +interesting thing is that these two + + + align:start position:0% +interesting thing is that these two +teams are completely coordinated so + + align:start position:0% +teams are completely coordinated so + + + align:start position:0% +teams are completely coordinated so +where have you seen him before + + align:start position:0% +where have you seen him before + + + align:start position:0% +where have you seen him before +that reversibly mines oxygen we're gonna + + align:start position:0% +that reversibly mines oxygen we're gonna + + + align:start position:0% +that reversibly mines oxygen we're gonna +but we need to do something with oxygen + + align:start position:0% +but we need to do something with oxygen + + + align:start position:0% +but we need to do something with oxygen +oxygen is getting reduced okay but what + + align:start position:0% +oxygen is getting reduced okay but what + + + align:start position:0% +oxygen is getting reduced okay but what +I'm telling you is that oxygen does not + + align:start position:0% +I'm telling you is that oxygen does not + + + align:start position:0% +I'm telling you is that oxygen does not +get reduced by binding to the heme okay + + align:start position:0% +get reduced by binding to the heme okay + + + align:start position:0% +get reduced by binding to the heme okay +it's going to be using this method of + + align:start position:0% +it's going to be using this method of + + + align:start position:0% +it's going to be using this method of +electron transfer that we talked about + + align:start position:0% +electron transfer that we talked about + + + align:start position:0% +electron transfer that we talked about +so they got to be close enough so you + + align:start position:0% +so they got to be close enough so you + + + align:start position:0% +so they got to be close enough so you +can do electron transfer perhaps through + + align:start position:0% +can do electron transfer perhaps through + + + align:start position:0% +can do electron transfer perhaps through +the heme edge and the protein so + + align:start position:0% +the heme edge and the protein so + + + align:start position:0% +the heme edge and the protein so +ultimately oxygen + + align:start position:0% +ultimately oxygen + + + align:start position:0% +ultimately oxygen +is getting converted into superoxide not + + align:start position:0% +is getting converted into superoxide not + + + align:start position:0% +is getting converted into superoxide not +by direct finding to the heme okay so + + align:start position:0% +by direct finding to the heme okay so + + + align:start position:0% +by direct finding to the heme okay so +this is distinct and we'll see this is + + align:start position:0% +this is distinct and we'll see this is + + + align:start position:0% +this is distinct and we'll see this is +completely distinct from the Milo + + align:start position:0% +completely distinct from the Milo + + + align:start position:0% +completely distinct from the Milo +peroxidases is completely distinct from + + align:start position:0% +peroxidases is completely distinct from + + + align:start position:0% +peroxidases is completely distinct from +the p450s we alluded to when we're + + align:start position:0% +the p450s we alluded to when we're + + + align:start position:0% +the p450s we alluded to when we're +talking about cholesterol homeostasis + + align:start position:0% +talking about cholesterol homeostasis + + + align:start position:0% +talking about cholesterol homeostasis +and the key that makes all of this work + + align:start position:0% +and the key that makes all of this work + + + align:start position:0% +and the key that makes all of this work +is that it can form complexes with other + + align:start position:0% +is that it can form complexes with other + + + align:start position:0% +is that it can form complexes with other +proteins okay so let me just tell you + + align:start position:0% +proteins okay so let me just tell you + + + align:start position:0% +proteins okay so let me just tell you +what those other proteins are and that + + align:start position:0% +what those other proteins are and that + + + align:start position:0% +what those other proteins are and that +was described in some detail in the + + align:start position:0% +was described in some detail in the + + + align:start position:0% +was described in some detail in the +reading so we're gonna have a GTP a's + + align:start position:0% +reading so we're gonna have a GTP a's + + + align:start position:0% +reading so we're gonna have a GTP a's +rack 2 is a g protein okay so g proteins + + align:start position:0% +rack 2 is a g protein okay so g proteins + + + align:start position:0% +rack 2 is a g protein okay so g proteins +can mediate phosphorylations this one + + align:start position:0% +can mediate phosphorylations this one + + + align:start position:0% +can mediate phosphorylations this one +mediates phosphorylations and yet is + + align:start position:0% +mediates phosphorylations and yet is + + + align:start position:0% +mediates phosphorylations and yet is +remains in the inhibited state - you + + align:start position:0% +remains in the inhibited state - you + + + align:start position:0% +remains in the inhibited state - you +need to trigger off your signaling + + align:start position:0% +need to trigger off your signaling + + + align:start position:0% +need to trigger off your signaling +cascade by another protein then the + + align:start position:0% +cascade by another protein then the + + + align:start position:0% +cascade by another protein then the +nomenclature is horrible but there's an + + align:start position:0% +nomenclature is horrible but there's an + + + align:start position:0% +nomenclature is horrible but there's an +inhibitor protein that binds to the g + + align:start position:0% +inhibitor protein that binds to the g + + + align:start position:0% +inhibitor protein that binds to the g +protein making it inactive when some + + align:start position:0% +protein making it inactive when some + + + align:start position:0% +protein making it inactive when some +sensor comes in they dissociate and then + + align:start position:0% +sensor comes in they dissociate and then + + + align:start position:0% +sensor comes in they dissociate and then +the G protein can function and we're + + align:start position:0% +the G protein can function and we're + + + align:start position:0% +the G protein can function and we're +gonna look at that kind of signaling we + + align:start position:0% +gonna look at that kind of signaling we + + + align:start position:0% +gonna look at that kind of signaling we +already have looked at that kind of + + align:start position:0% +already have looked at that kind of + + + align:start position:0% +already have looked at that kind of +signaling and the Carroll paper but + + align:start position:0% +signaling and the Carroll paper but + + + align:start position:0% +signaling and the Carroll paper but +we'll look at it again and signaling by + + align:start position:0% +we'll look at it again and signaling by + + + align:start position:0% +we'll look at it again and signaling by +Knox the second group of proteins again + + align:start position:0% +Knox the second group of proteins again + + + align:start position:0% +Knox the second group of proteins again +they're based on the size these were + + align:start position:0% +they're based on the size these were + + + align:start position:0% +they're based on the size these were +identified a long time ago they're + + align:start position:0% +identified a long time ago they're + + + align:start position:0% +identified a long time ago they're +unique to the phagosome they called + + align:start position:0% +unique to the phagosome they called + + + align:start position:0% +unique to the phagosome they called +phagosome oxidases that's going to be + + align:start position:0% +phagosome oxidases that's going to be + + + align:start position:0% +phagosome oxidases that's going to be +the organelle where we're going to kill + + align:start position:0% +the organelle where we're going to kill + + + align:start position:0% +the organelle where we're going to kill +the bacteria and so this p-47 needs to + + align:start position:0% +the bacteria and so this p-47 needs to + + + align:start position:0% +the bacteria and so this p-47 needs to +be phosphorylated and it's + + align:start position:0% +be phosphorylated and it's + + + align:start position:0% +be phosphorylated and it's +phosphorylated by the G protein and + + align:start position:0% +phosphorylated by the G protein and + + + align:start position:0% +phosphorylated by the G protein and +that's key to have everything come + + align:start position:0% +that's key to have everything come + + + align:start position:0% +that's key to have everything come +together - a lot of the chemistry happen + + align:start position:0% +together - a lot of the chemistry happen + + + align:start position:0% +together - a lot of the chemistry happen +so this chemistry in this form it's + + align:start position:0% +so this chemistry in this form it's + + + align:start position:0% +so this chemistry in this form it's +inactive it's only when everything comes + + align:start position:0% +inactive it's only when everything comes + + + align:start position:0% +inactive it's only when everything comes +together that you actually start doing + + align:start position:0% +together that you actually start doing + + + align:start position:0% +together that you actually start doing +the chemistry that's gonna kind of help + + align:start position:0% +the chemistry that's gonna kind of help + + + align:start position:0% +the chemistry that's gonna kind of help +us okay so here's the model so here's a + + align:start position:0% +us okay so here's the model so here's a + + + align:start position:0% +us okay so here's the model so here's a +resting cell this is the nucleus here + + align:start position:0% +resting cell this is the nucleus here + + + align:start position:0% +resting cell this is the nucleus here +the blue thing is the No + + align:start position:0% +the blue thing is the No + + + align:start position:0% +the blue thing is the No +protein okay and the little the little + + align:start position:0% +protein okay and the little the little + + + align:start position:0% +protein okay and the little the little +blue thing is the second subunit this is + + align:start position:0% +blue thing is the second subunit this is + + + align:start position:0% +blue thing is the second subunit this is +the 91 this is the 22 here we can see + + align:start position:0% +the 91 this is the 22 here we can see + + + align:start position:0% +the 91 this is the 22 here we can see +that it's located in the plasma membrane + + align:start position:0% +that it's located in the plasma membrane + + + align:start position:0% +that it's located in the plasma membrane +that's one of its locations that's not + + align:start position:0% +that's one of its locations that's not + + + align:start position:0% +that's one of its locations that's not +the predominant location and the resting + + align:start position:0% +the predominant location and the resting + + + align:start position:0% +the predominant location and the resting +state the predominant location + + align:start position:0% +state the predominant location + + + align:start position:0% +state the predominant location +apparently is in little vesicles within + + align:start position:0% +apparently is in little vesicles within + + + align:start position:0% +apparently is in little vesicles within +these neutrophils the white blood cells + + align:start position:0% +these neutrophils the white blood cells + + + align:start position:0% +these neutrophils the white blood cells +that are the first defenders against + + align:start position:0% +that are the first defenders against + + + align:start position:0% +that are the first defenders against +invasion by bacterial systems and then + + align:start position:0% +invasion by bacterial systems and then + + + align:start position:0% +invasion by bacterial systems and then +we have these little complexes + + align:start position:0% +we have these little complexes + + + align:start position:0% +we have these little complexes +here's rack to a GT pas that's inhibited + + align:start position:0% +here's rack to a GT pas that's inhibited + + + align:start position:0% +here's rack to a GT pas that's inhibited +and here is the phagosome oxidase okay + + align:start position:0% +and here is the phagosome oxidase okay + + + align:start position:0% +and here is the phagosome oxidase okay +and then what happens when the bacteria + + align:start position:0% +and then what happens when the bacteria + + + align:start position:0% +and then what happens when the bacteria +comes in somehow the bacteria is coming + + align:start position:0% +comes in somehow the bacteria is coming + + + align:start position:0% +comes in somehow the bacteria is coming +in over here it gets engulfed and you + + align:start position:0% +in over here it gets engulfed and you + + + align:start position:0% +in over here it gets engulfed and you +form these little phagosome x' inside + + align:start position:0% +form these little phagosome x' inside + + + align:start position:0% +form these little phagosome x' inside +the cell okay and now what happens is + + align:start position:0% +the cell okay and now what happens is + + + align:start position:0% +the cell okay and now what happens is +the NADPH the NOx proteins are located + + align:start position:0% +the NADPH the NOx proteins are located + + + align:start position:0% +the NADPH the NOx proteins are located +like this the NADPH is on the outside + + align:start position:0% +like this the NADPH is on the outside + + + align:start position:0% +like this the NADPH is on the outside +it's been activated by this gtp ace and + + align:start position:0% +it's been activated by this gtp ace and + + + align:start position:0% +it's been activated by this gtp ace and +now it's ready to generate superoxide + + align:start position:0% +now it's ready to generate superoxide + + + align:start position:0% +now it's ready to generate superoxide +inside the cell okay so there's a lot of + + align:start position:0% +inside the cell okay so there's a lot of + + + align:start position:0% +inside the cell okay so there's a lot of +membrane fusion and reorganization + + align:start position:0% +membrane fusion and reorganization + + + align:start position:0% +membrane fusion and reorganization +obviously the signaling is really + + align:start position:0% +obviously the signaling is really + + + align:start position:0% +obviously the signaling is really +complex we know a lot about the + + align:start position:0% +complex we know a lot about the + + + align:start position:0% +complex we know a lot about the +signaling how do these guys even know + + align:start position:0% +signaling how do these guys even know + + + align:start position:0% +signaling how do these guys even know +there's a bacteria out there okay how do + + align:start position:0% +there's a bacteria out there okay how do + + + align:start position:0% +there's a bacteria out there okay how do +they sense all of that and I don't know + + align:start position:0% +they sense all of that and I don't know + + + align:start position:0% +they sense all of that and I don't know +if this is gonna work but you should + + align:start position:0% +if this is gonna work but you should + + + align:start position:0% +if this is gonna work but you should +lose a sort of a cool picture of it if + + align:start position:0% +lose a sort of a cool picture of it if + + + align:start position:0% +lose a sort of a cool picture of it if +it does work although it worked in my + + align:start position:0% +it does work although it worked in my + + + align:start position:0% +it does work although it worked in my +office but it might not work here oh + + align:start position:0% +office but it might not work here oh + + + align:start position:0% +office but it might not work here oh +here it goes so here we are this is a + + align:start position:0% +here it goes so here we are this is a + + + align:start position:0% +here it goes so here we are this is a +white blood cell these are red blood + + align:start position:0% +white blood cell these are red blood + + + align:start position:0% +white blood cell these are red blood +cells the bacteria these little things + + align:start position:0% +cells the bacteria these little things + + + align:start position:0% +cells the bacteria these little things +floating around is sending off a signal + + align:start position:0% +floating around is sending off a signal + + + align:start position:0% +floating around is sending off a signal +the white blood cell is chasing the + + align:start position:0% +the white blood cell is chasing the + + + align:start position:0% +the white blood cell is chasing the +bacteria okay so this some sequence is + + align:start position:0% +bacteria okay so this some sequence is + + + align:start position:0% +bacteria okay so this some sequence is +chasing it through all of these cells + + align:start position:0% +chasing it through all of these cells + + + align:start position:0% +chasing it through all of these cells +and you're going to see that in a minute + + align:start position:0% +and you're going to see that in a minute + + + align:start position:0% +and you're going to see that in a minute +it gets it there goes gets inside so now + + align:start position:0% +it gets it there goes gets inside so now + + + align:start position:0% +it gets it there goes gets inside so now +in the phagosome and PUF everything + + align:start position:0% +in the phagosome and PUF everything + + + align:start position:0% +in the phagosome and PUF everything +disappears and that is really what's + + align:start position:0% +disappears and that is really what's + + + align:start position:0% +disappears and that is really what's +going on in these systems so the + + align:start position:0% +going on in these systems so the + + + align:start position:0% +going on in these systems so the +question is it's a really cool picture + + align:start position:0% +question is it's a really cool picture + + + align:start position:0% +question is it's a really cool picture +the question is what's the chemistry + + align:start position:0% +the question is what's the chemistry + + + align:start position:0% +the question is what's the chemistry +that's actually going on in the + + align:start position:0% +that's actually going on in the + + + align:start position:0% +that's actually going on in the +systems okay so the chemistry whoops + + align:start position:0% +systems okay so the chemistry whoops + + + align:start position:0% +systems okay so the chemistry whoops +somehow my lost I'm already over the + + align:start position:0% +somehow my lost I'm already over the + + + align:start position:0% +somehow my lost I'm already over the +chemistry it's all over already what + + align:start position:0% +chemistry it's all over already what + + + align:start position:0% +chemistry it's all over already what +we'll do next time is come back and talk + + align:start position:0% +we'll do next time is come back and talk + + + align:start position:0% +we'll do next time is come back and talk +about how this flavin works and then + + align:start position:0% +about how this flavin works and then + + + align:start position:0% +about how this flavin works and then +we'll see in that little phagosome also + + align:start position:0% +we'll see in that little phagosome also + + + align:start position:0% +we'll see in that little phagosome also +is the Milo peroxidase we'll talk about + + align:start position:0% +is the Milo peroxidase we'll talk about + + + align:start position:0% +is the Milo peroxidase we'll talk about +how that works and those are the two + + align:start position:0% +how that works and those are the two + + + align:start position:0% +how that works and those are the two +things I want how did they degrade this + + align:start position:0% +things I want how did they degrade this + + + align:start position:0% +things I want how did they degrade this +bacteria once they get inside this + + align:start position:0% +bacteria once they get inside this + + + align:start position:0% +bacteria once they get inside this +little organelle + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/J0pZyXThRmM.txt b/J0pZyXThRmM.txt new file mode 100644 index 0000000000000000000000000000000000000000..f5e55e7bc08755f1aecc2e126b115ea46410976b --- /dev/null +++ b/J0pZyXThRmM.txt @@ -0,0 +1,6067 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay hi so I've got the + + align:start position:0% +ocw.mit.edu okay hi so I've got the + + + align:start position:0% +ocw.mit.edu okay hi so I've got the +homework nine for you uh ready to return + + align:start position:0% +homework nine for you uh ready to return + + + align:start position:0% +homework nine for you uh ready to return +at the end uh also the department asked + + align:start position:0% +at the end uh also the department asked + + + align:start position:0% +at the end uh also the department asked +me to do evaluations but that's the end + + align:start position:0% +me to do evaluations but that's the end + + + align:start position:0% +me to do evaluations but that's the end +of the lecture then uh so everybody + + align:start position:0% +of the lecture then uh so everybody + + + align:start position:0% +of the lecture then uh so everybody +knows there's a quiz um tomorrow night + + align:start position:0% +knows there's a quiz um tomorrow night + + + align:start position:0% +knows there's a quiz um tomorrow night +and uh shall I just remember the four + + align:start position:0% +and uh shall I just remember the four + + + align:start position:0% +and uh shall I just remember the four +questions on the quiz I mean not the + + align:start position:0% +questions on the quiz I mean not the + + + align:start position:0% +questions on the quiz I mean not the +details but the general idea of the + + align:start position:0% +details but the general idea of the + + + align:start position:0% +details but the general idea of the +question details okay too yes uh yeah so + + align:start position:0% +question details okay too yes uh yeah so + + + align:start position:0% +question details okay too yes uh yeah so +there'll be one question on a Fier + + align:start position:0% +there'll be one question on a Fier + + + align:start position:0% +there'll be one question on a Fier +series and uh you should know that + + align:start position:0% +series and uh you should know that + + + align:start position:0% +series and uh you should know that +energy equality with connect for all of + + align:start position:0% +energy equality with connect for all of + + + align:start position:0% +energy equality with connect for all of +these possibilities connecting uh the + + align:start position:0% +these possibilities connecting uh the + + + align:start position:0% +these possibilities connecting uh the +function squared with the coefficient + + align:start position:0% +function squared with the coefficient + + + align:start position:0% +function squared with the coefficient +squared a second one on a discrete 4A + + align:start position:0% +squared a second one on a discrete 4A + + + align:start position:0% +squared a second one on a discrete 4A +transform cyclic stuff the third one on + + align:start position:0% +transform cyclic stuff the third one on + + + align:start position:0% +transform cyclic stuff the third one on +the 4A + + align:start position:0% + + + + align:start position:0% + +integral and uh have a look at the + + align:start position:0% +integral and uh have a look at the + + + align:start position:0% +integral and uh have a look at the +applications to solving + + align:start position:0% +applications to solving + + + align:start position:0% +applications to solving +um uh an + + align:start position:0% +um uh an + + + align:start position:0% +um uh an +OD um I did one in class uh like there + + align:start position:0% +OD um I did one in class uh like there + + + align:start position:0% +OD um I did one in class uh like there +was the one in class was the one in the + + align:start position:0% +was the one in class was the one in the + + + align:start position:0% +was the one in class was the one in the +book minus U prime plus a^2 U equal F + + align:start position:0% +book minus U prime plus a^2 U equal F + + + align:start position:0% +book minus U prime plus a^2 U equal F +ofx so this will be uh so have a look at + + align:start position:0% +ofx so this will be uh so have a look at + + + align:start position:0% +ofx so this will be uh so have a look at +that + + align:start position:0% +that + + + align:start position:0% +that +application that this is of course on + + align:start position:0% +application that this is of course on + + + align:start position:0% +application that this is of course on +minus infinity to infinity and then a + + align:start position:0% +minus infinity to infinity and then a + + + align:start position:0% +minus infinity to infinity and then a +fourth question on + + align:start position:0% + + + + align:start position:0% + +convolution okay + + align:start position:0% +convolution okay + + + align:start position:0% +convolution okay +and I'll this afternoon of course I'll + + align:start position:0% +and I'll this afternoon of course I'll + + + align:start position:0% +and I'll this afternoon of course I'll +be here to answer any questions from the + + align:start position:0% +be here to answer any questions from the + + + align:start position:0% +be here to answer any questions from the +homework from from uh any source for for + + align:start position:0% +homework from from uh any source for for + + + align:start position:0% +homework from from uh any source for for +these + + align:start position:0% +these + + + align:start position:0% +these +topics are there any questions just now + + align:start position:0% +topics are there any questions just now + + + align:start position:0% +topics are there any questions just now +though I'm okay to take + + align:start position:0% +though I'm okay to take + + + align:start position:0% +though I'm okay to take +questions I thought I'd discuss today a + + align:start position:0% +questions I thought I'd discuss today a + + + align:start position:0% +questions I thought I'd discuss today a +topic uh that involves both Fier series + + align:start position:0% +topic uh that involves both Fier series + + + align:start position:0% +topic uh that involves both Fier series +and Fier integrals it's a kind of cool + + align:start position:0% +and Fier integrals it's a kind of cool + + + align:start position:0% +and Fier integrals it's a kind of cool +uh + + align:start position:0% +uh + + + align:start position:0% +uh +connection and it's no it's linked to + + align:start position:0% +connection and it's no it's linked to + + + align:start position:0% +connection and it's no it's linked to +the the name of Claude Shannon who + + align:start position:0% +the the name of Claude Shannon who + + + align:start position:0% +the the name of Claude Shannon who +created information Theory who was a b + + align:start position:0% +created information Theory who was a b + + + align:start position:0% +created information Theory who was a b +Labs uh guy and then an MIT Professor uh + + align:start position:0% +Labs uh guy and then an MIT Professor uh + + + align:start position:0% +Labs uh guy and then an MIT Professor uh +so I should put his name in + + align:start position:0% +so I should put his name in + + + align:start position:0% +so I should put his name in +Shannon okay so this is + + align:start position:0% +Shannon okay so this is + + + align:start position:0% +Shannon okay so this is +uh yeah you you'll + + align:start position:0% +uh yeah you you'll + + + align:start position:0% +uh yeah you you'll +see so it's it's not on the quiz but it + + align:start position:0% +see so it's it's not on the quiz but it + + + align:start position:0% +see so it's it's not on the quiz but it +gives me a chance to say something + + align:start position:0% +gives me a chance to say something + + + align:start position:0% +gives me a chance to say something +important and at the same time review + + align:start position:0% +important and at the same time review + + + align:start position:0% +important and at the same time review +fora series and fora integrals so let me + + align:start position:0% +fora series and fora integrals so let me + + + align:start position:0% +fora series and fora integrals so let me +start with the the the problem uh the + + align:start position:0% +start with the the the problem uh the + + + align:start position:0% +start with the the the problem uh the +problem comes for a for an a to d + + align:start position:0% +problem comes for a for an a to d + + + align:start position:0% +problem comes for a for an a to d +converter so so what does that + + align:start position:0% +converter so so what does that + + + align:start position:0% +converter so so what does that +mean that means this a is analog that + + align:start position:0% +mean that means this a is analog that + + + align:start position:0% +mean that means this a is analog that +means we have a function a for + + align:start position:0% + + + + align:start position:0% + +analog and D for digital + + align:start position:0% +analog and D for digital + + + align:start position:0% +analog and D for digital +so we have a + + align:start position:0% +so we have a + + + align:start position:0% +so we have a +function like so F + + align:start position:0% +function like so F + + + align:start position:0% +function like so F +ofx say all the way minus infinity to + + align:start position:0% +ofx say all the way minus infinity to + + + align:start position:0% +ofx say all the way minus infinity to +Infinity so we'll be + + align:start position:0% +Infinity so we'll be + + + align:start position:0% +Infinity so we'll be +doing that's where the fora integral is + + align:start position:0% +doing that's where the fora integral is + + + align:start position:0% +doing that's where the fora integral is +going to come up so that's analog all X + + align:start position:0% +going to come up so that's analog all X + + + align:start position:0% +going to come up so that's analog all X +it's it's some some curve and people + + align:start position:0% +it's it's some some curve and people + + + align:start position:0% +it's it's some some curve and people +build and you can + + align:start position:0% +build and you can + + + align:start position:0% +build and you can +buy and they're sold in large quantities + + align:start position:0% +buy and they're sold in large quantities + + + align:start position:0% +buy and they're sold in large quantities +and a something that just samples that + + align:start position:0% +and a something that just samples that + + + align:start position:0% +and a something that just samples that +function say at the integers so so now + + align:start position:0% +function say at the integers so so now + + + align:start position:0% +function say at the integers so so now +I'll I'll + + align:start position:0% +I'll I'll + + + align:start position:0% +I'll I'll +sample that function and let me take the + + align:start position:0% +sample that function and let me take the + + + align:start position:0% +sample that function and let me take the +period of the sample to be one so that + + align:start position:0% +period of the sample to be one so that + + + align:start position:0% +period of the sample to be one so that +I'm going to take the values F + + align:start position:0% + + + + align:start position:0% + +ofn so now I've got something digital + + align:start position:0% +ofn so now I've got something digital + + + align:start position:0% +ofn so now I've got something digital +that I can work with that I can compute + + align:start position:0% +that I can work with that I can compute + + + align:start position:0% +that I can work with that I can compute +with and uh so the sampling + + align:start position:0% +with and uh so the sampling + + + align:start position:0% +with and uh so the sampling +theorem well I mean the question yeah so + + align:start position:0% +theorem well I mean the question yeah so + + + align:start position:0% +theorem well I mean the question yeah so +the sampling theorem is about this + + align:start position:0% +the sampling theorem is about this + + + align:start position:0% +the sampling theorem is about this +question and it seems a crazy question + + align:start position:0% +question and it seems a crazy question + + + align:start position:0% +question and it seems a crazy question +when do these numbers that's just a + + align:start position:0% +when do these numbers that's just a + + + align:start position:0% +when do these numbers that's just a +sequence of numbers this x was all the + + align:start position:0% +sequence of numbers this x was all the + + + align:start position:0% +sequence of numbers this x was all the +way from minus infinity to + + align:start position:0% +way from minus infinity to + + + align:start position:0% +way from minus infinity to +infinity and similarly n is numbers all + + align:start position:0% +infinity and similarly n is numbers all + + + align:start position:0% +infinity and similarly n is numbers all +the way from minus infinity to Infinity + + align:start position:0% +the way from minus infinity to Infinity + + + align:start position:0% +the way from minus infinity to Infinity +but just samples when does that tell me + + align:start position:0% +but just samples when does that tell me + + + align:start position:0% +but just samples when does that tell me +the + + align:start position:0% +the + + + align:start position:0% +the +function when can I learn from those + + align:start position:0% +function when can I learn from those + + + align:start position:0% +function when can I learn from those +samples when do I have total information + + align:start position:0% +samples when do I have total information + + + align:start position:0% +samples when do I have total information +about the function now you'll say + + align:start position:0% +about the function now you'll say + + + align:start position:0% +about the function now you'll say +impossible right so so suppose + + align:start position:0% +impossible right so so suppose + + + align:start position:0% +impossible right so so suppose +I draw a function f + + align:start position:0% +I draw a function f + + + align:start position:0% +I draw a function f +ofx okay and I'm going to sample it at + + align:start position:0% +ofx okay and I'm going to sample it at + + + align:start position:0% +ofx okay and I'm going to sample it at +those at these points so I'm going to + + align:start position:0% +those at these points so I'm going to + + + align:start position:0% +those at these points so I'm going to +all all the way so these are the numbers + + align:start position:0% +all all the way so these are the numbers + + + align:start position:0% +all all the way so these are the numbers +these are my f of + + align:start position:0% +these are my f of + + + align:start position:0% +these are my f of +n sampling at equal intervals because if + + align:start position:0% +n sampling at equal intervals because if + + + align:start position:0% +n sampling at equal intervals because if +if we want to use fora ideas equal + + align:start position:0% +if we want to use fora ideas equal + + + align:start position:0% +if we want to use fora ideas equal +spacing is the right thing to have so + + align:start position:0% +spacing is the right thing to have so + + + align:start position:0% +spacing is the right thing to have so +when could I recover the function in + + align:start position:0% +when could I recover the function in + + + align:start position:0% +when could I recover the function in +between well you'd say never because how + + align:start position:0% +between well you'd say never because how + + + align:start position:0% +between well you'd say never because how +do I know what what that function could + + align:start position:0% +do I know what what that function could + + + align:start position:0% +do I know what what that function could +be doing in between so let me take uh + + align:start position:0% +be doing in between so let me take uh + + + align:start position:0% +be doing in between so let me take uh +the case when all the all the samples + + align:start position:0% +the case when all the all the samples + + + align:start position:0% +the case when all the all the samples +are zero and and let's think about that + + align:start position:0% +are zero and and let's think about that + + + align:start position:0% +are zero and and let's think about that +case suppose what could the function + + align:start position:0% +case suppose what could the function + + + align:start position:0% +case suppose what could the function +be if all the samples if if these are + + align:start position:0% +be if all the samples if if these are + + + align:start position:0% +be if all the samples if if these are +all + + align:start position:0% + + + + align:start position:0% + +zeros + + align:start position:0% +zeros + + + align:start position:0% +zeros +forever okay well there's one leading + + align:start position:0% +forever okay well there's one leading + + + align:start position:0% +forever okay well there's one leading +candidate for the + + align:start position:0% +candidate for the + + + align:start position:0% +candidate for the +function the zero function now what tell + + align:start position:0% +function the zero function now what tell + + + align:start position:0% +function the zero function now what tell +if if you will see the whole point of + + align:start position:0% +if if you will see the whole point of + + + align:start position:0% +if if you will see the whole point of +the sampling theorem if you think about + + align:start position:0% +the sampling theorem if you think about + + + align:start position:0% +the sampling theorem if you think about +other what other + + align:start position:0% +other what other + + + align:start position:0% +other what other +functions familiar functions yeah I mean + + align:start position:0% +functions familiar functions yeah I mean + + + align:start position:0% +functions familiar functions yeah I mean +we could obviously any all sorts of + + align:start position:0% +we could obviously any all sorts of + + + align:start position:0% +we could obviously any all sorts of +things but but since we're doing + + align:start position:0% +things but but since we're doing + + + align:start position:0% +things but but since we're doing +forier we like to pick on the SS + + align:start position:0% +forier we like to pick on the SS + + + align:start position:0% +forier we like to pick on the SS +cosiness the the special functions and + + align:start position:0% +cosiness the the special functions and + + + align:start position:0% +cosiness the the special functions and +think about those in particular + + align:start position:0% +think about those in particular + + + align:start position:0% +think about those in particular +so somebody said Signs Now what what + + align:start position:0% +so somebody said Signs Now what what + + + align:start position:0% +so somebody said Signs Now what what +function + + align:start position:0% +function + + + align:start position:0% +function +what sign so a sign function certainly + + align:start position:0% +what sign so a sign function certainly + + + align:start position:0% +what sign so a sign function certainly +the sign function hits zero infinitely + + align:start position:0% +the sign function hits zero infinitely + + + align:start position:0% +the sign function hits zero infinitely +often what frequency so what sign of + + align:start position:0% +often what frequency so what sign of + + + align:start position:0% +often what frequency so what sign of +what it would give me the same answer + + align:start position:0% +what it would give me the same answer + + + align:start position:0% +what it would give me the same answer +the same samples give if I put this sign + + align:start position:0% +the same samples give if I put this sign + + + align:start position:0% +the same samples give if I put this sign +function that you're going to tell me so + + align:start position:0% +function that you're going to tell me so + + + align:start position:0% +function that you're going to tell me so +you're going to tell me it's it's s of + + align:start position:0% +you're going to tell me it's it's s of + + + align:start position:0% +you're going to tell me it's it's s of +something will have these zero values at + + align:start position:0% +something will have these zero values at + + + align:start position:0% +something will have these zero values at +all the integers at0 one 1 2 -1 -2 and + + align:start position:0% +all the integers at0 one 1 2 -1 -2 and + + + align:start position:0% +all the integers at0 one 1 2 -1 -2 and +so on so what would do what would do the + + align:start position:0% +so on so what would do what would do the + + + align:start position:0% +so on so what would do what would do the +job s + + align:start position:0% + + + + align:start position:0% + +of of what will happen will hit zero so + + align:start position:0% +of of what will happen will hit zero so + + + align:start position:0% +of of what will happen will hit zero so +I'm looking for S + + align:start position:0% +I'm looking for S + + + align:start position:0% +I'm looking for S +functions I'm looking I guess I'm + + align:start position:0% +functions I'm looking I guess I'm + + + align:start position:0% +functions I'm looking I guess I'm +looking first for the function that that + + align:start position:0% +looking first for the function that that + + + align:start position:0% +looking first for the function that that +just just does that and and what is it + + align:start position:0% +just just does that and and what is it + + + align:start position:0% +just just does that and and what is it +sin + + align:start position:0% +sin + + + align:start position:0% +sin +pix and and now tell me some more tell + + align:start position:0% +pix and and now tell me some more tell + + + align:start position:0% +pix and and now tell me some more tell +me another function which will also it + + align:start position:0% +me another function which will also it + + + align:start position:0% +me another function which will also it +won't be that + + align:start position:0% +won't be that + + + align:start position:0% +won't be that +graph S 2 + + align:start position:0% +graph S 2 + + + align:start position:0% +graph S 2 +pix and and + + align:start position:0% +pix and and + + + align:start position:0% +pix and and +all the rest okay let me let me just use + + align:start position:0% +all the rest okay let me let me just use + + + align:start position:0% +all the rest okay let me let me just use +a word that's kind of a handy word of + + align:start position:0% +a word that's kind of a handy word of + + + align:start position:0% +a word that's kind of a handy word of +course let's put zero on the list + + align:start position:0% +course let's put zero on the list + + + align:start position:0% +course let's put zero on the list +here okay I so this is the frequ this is + + align:start position:0% +here okay I so this is the frequ this is + + + align:start position:0% +here okay I so this is the frequ this is +where K the frequency usually appears + + align:start position:0% +where K the frequency usually appears + + + align:start position:0% +where K the frequency usually appears +this is where 2 pi usually this is where + + align:start position:0% +this is where 2 pi usually this is where + + + align:start position:0% +this is where 2 pi usually this is where +K those I would the word I want to + + align:start position:0% +K those I would the word I want to + + + align:start position:0% +K those I would the word I want to +introduce is + + align:start position:0% +introduce is + + + align:start position:0% +introduce is +Alias the this + + align:start position:0% +Alias the this + + + align:start position:0% +Alias the this +frequency Pi is an alias for this had + + align:start position:0% +frequency Pi is an alias for this had + + + align:start position:0% +frequency Pi is an alias for this had +frequency zero here's + + align:start position:0% +frequency zero here's + + + align:start position:0% +frequency zero here's +the it's a different function but yet + + align:start position:0% +the it's a different function but yet + + + align:start position:0% +the it's a different function but yet +the samples are the same so if you're + + align:start position:0% +the samples are the same so if you're + + + align:start position:0% +the samples are the same so if you're +only looking at the + + align:start position:0% +only looking at the + + + align:start position:0% +only looking at the +samples uh you're getting the same + + align:start position:0% +samples uh you're getting the same + + + align:start position:0% +samples uh you're getting the same +answer and and but but somehow the + + align:start position:0% +answer and and but but somehow the + + + align:start position:0% +answer and and but but somehow the +function has a different name so so that + + align:start position:0% +function has a different name so so that + + + align:start position:0% +function has a different name so so that +frequency and this frequency and and all + + align:start position:0% +frequency and this frequency and and all + + + align:start position:0% +frequency and this frequency and and all +those others would be Alias can I just + + align:start position:0% +those others would be Alias can I just + + + align:start position:0% +those others would be Alias can I just +write that word down because it you see + + align:start position:0% +write that word down because it you see + + + align:start position:0% +write that word down because it you see +it often + + align:start position:0% +it often + + + align:start position:0% +it often +Alias those are two that means two + + align:start position:0% +Alias those are two that means two + + + align:start position:0% +Alias those are two that means two +frequencies like pi and two pi and zero + + align:start position:0% +frequencies like pi and two pi and zero + + + align:start position:0% +frequencies like pi and two pi and zero +or whatever that give you the same + + align:start position:0% +or whatever that give you the same + + + align:start position:0% +or whatever that give you the same +samples okay so what now comes Shannon's + + align:start position:0% +samples okay so what now comes Shannon's + + + align:start position:0% +samples okay so what now comes Shannon's +question what uh so we have to make some + + align:start position:0% +question what uh so we have to make some + + + align:start position:0% +question what uh so we have to make some +assum on the + + align:start position:0% +assum on the + + + align:start position:0% +assum on the +function to to knock out those + + align:start position:0% +function to to knock out those + + + align:start position:0% +function to to knock out those +possibilities we have to we'll have we + + align:start position:0% +possibilities we have to we'll have we + + + align:start position:0% +possibilities we have to we'll have we +wanted now a limited class of + + align:start position:0% +wanted now a limited class of + + + align:start position:0% +wanted now a limited class of +functions for which which don't include + + align:start position:0% +functions for which which don't include + + + align:start position:0% +functions for which which don't include +these + + align:start position:0% +these + + + align:start position:0% +these +guys so that within this limited class + + align:start position:0% +guys so that within this limited class + + + align:start position:0% +guys so that within this limited class +of functions this is the only candidate + + align:start position:0% +of functions this is the only candidate + + + align:start position:0% +of functions this is the only candidate +and and we we have this possibility of + + align:start position:0% +and and we we have this possibility of + + + align:start position:0% +and and we we have this possibility of +of doing the impossible of of + + align:start position:0% +of doing the impossible of of + + + align:start position:0% +of doing the impossible of of +determining that + + align:start position:0% +determining that + + + align:start position:0% +determining that +if I know Zer here the function has to + + align:start position:0% +if I know Zer here the function has to + + + align:start position:0% +if I know Zer here the function has to +be zero + + align:start position:0% +be zero + + + align:start position:0% +be zero +everywhere okay now the question is what + + align:start position:0% +everywhere okay now the question is what + + + align:start position:0% +everywhere okay now the question is what +what class of functions we we want to + + align:start position:0% +what class of functions we we want to + + + align:start position:0% +what class of functions we we want to +eliminate these guys and and sort of + + align:start position:0% +eliminate these guys and and sort of + + + align:start position:0% +eliminate these guys and and sort of +your instinct is you want to eliminate + + align:start position:0% +your instinct is you want to eliminate + + + align:start position:0% +your instinct is you want to eliminate +functions + + align:start position:0% +functions + + + align:start position:0% +functions +that uh you know if it's not zero then + + align:start position:0% +that uh you know if it's not zero then + + + align:start position:0% +that uh you know if it's not zero then +it's got to get up and back down in + + align:start position:0% +it's got to get up and back down in + + + align:start position:0% +it's got to get up and back down in +every in everything it it could do + + align:start position:0% +every in everything it it could do + + + align:start position:0% +every in everything it it could do +different things in different intervals + + align:start position:0% +different things in different intervals + + + align:start position:0% +different things in different intervals +but somehow it it it's got to have some + + align:start position:0% +but somehow it it it's got to have some + + + align:start position:0% +but somehow it it it's got to have some +some of these + + align:start position:0% +some of these + + + align:start position:0% +some of these +frequencies Pi or + + align:start position:0% +frequencies Pi or + + + align:start position:0% +frequencies Pi or +higher would have to be in there so this + + align:start position:0% +higher would have to be in there so this + + + align:start position:0% +higher would have to be in there so this +is this is the Instinct that that if I + + align:start position:0% +is this is the Instinct that that if I + + + align:start position:0% +is this is the Instinct that that if I +limit the frequency band so so I'm going + + align:start position:0% +limit the frequency band so so I'm going + + + align:start position:0% +limit the frequency band so so I'm going +to say I'm going to say f ofx is band + + align:start position:0% +to say I'm going to say f ofx is band + + + align:start position:0% +to say I'm going to say f ofx is band +limited let me can I introduce that word + + align:start position:0% +limited let me can I introduce that word + + + align:start position:0% +limited let me can I introduce that word +I don't I'll maybe take a moment just to + + align:start position:0% +I don't I'll maybe take a moment just to + + + align:start position:0% +I don't I'll maybe take a moment just to +ask you if you've seen that word before + + align:start position:0% +ask you if you've seen that word before + + + align:start position:0% +ask you if you've seen that word before +how many have seen this word band + + align:start position:0% +how many have seen this word band + + + align:start position:0% +how many have seen this word band +limited qu quite a few but not not half + + align:start position:0% +limited qu quite a few but not not half + + + align:start position:0% +limited qu quite a few but not not half +okay band limited + + align:start position:0% +okay band limited + + + align:start position:0% +okay band limited +means the band is a band of frequencies + + align:start position:0% +means the band is a band of frequencies + + + align:start position:0% +means the band is a band of frequencies +so it's the the function is band limited + + align:start position:0% +so it's the the function is band limited + + + align:start position:0% +so it's the the function is band limited +when it's transform this tells me how + + align:start position:0% +when it's transform this tells me how + + + align:start position:0% +when it's transform this tells me how +much of each frequency there is if this + + align:start position:0% +much of each frequency there is if this + + + align:start position:0% +much of each frequency there is if this +is zero in some band in in some band + + align:start position:0% +is zero in some band in in some band + + + align:start position:0% +is zero in some band in in some band +let's say all frequency is below + + align:start position:0% +let's say all frequency is below + + + align:start position:0% +let's say all frequency is below +something let's let's not even put equal + + align:start position:0% +something let's let's not even put equal + + + align:start position:0% +something let's let's not even put equal +in there okay but at least that's not + + align:start position:0% +in there okay but at least that's not + + + align:start position:0% +in there okay but at least that's not +critical so band limited I have to tell + + align:start position:0% +critical so band limited I have to tell + + + align:start position:0% +critical so band limited I have to tell +you the size of the + + align:start position:0% +you the size of the + + + align:start position:0% +you the size of the +band and the size of the band The the + + align:start position:0% +band and the size of the band The the + + + align:start position:0% +band and the size of the band The the +limiting frequency is this famous + + align:start position:0% +limiting frequency is this famous + + + align:start position:0% +limiting frequency is this famous +Nyquist frequency so Nyquist is a guy's + + align:start position:0% +Nyquist frequency so Nyquist is a guy's + + + align:start position:0% +Nyquist frequency so Nyquist is a guy's +name and the Nyquist frequency in our + + align:start position:0% +name and the Nyquist frequency in our + + + align:start position:0% +name and the Nyquist frequency in our +problem here is pi this is the Nyquist + + align:start position:0% +problem here is pi this is the Nyquist + + + align:start position:0% +problem here is pi this is the Nyquist +frequenc queny if we let that + + align:start position:0% +frequenc queny if we let that + + + align:start position:0% +frequenc queny if we let that +frequency that that's the borderline + + align:start position:0% + + + + align:start position:0% + +frequency or and there would be a + + align:start position:0% +frequency or and there would be a + + + align:start position:0% +frequency or and there would be a +similar Nyquist sampling rate yeah so so + + align:start position:0% +similar Nyquist sampling rate yeah so so + + + align:start position:0% +similar Nyquist sampling rate yeah so so +Nyquist is Nyquist is the is the guy who + + align:start position:0% +Nyquist is Nyquist is the is the guy who + + + align:start position:0% +Nyquist is Nyquist is the is the guy who +studied the sort of borderline case and + + align:start position:0% +studied the sort of borderline case and + + + align:start position:0% +studied the sort of borderline case and +the so the point is that if + + align:start position:0% +the so the point is that if + + + align:start position:0% +the so the point is that if +our say band limited by pi I have to + + align:start position:0% +our say band limited by pi I have to + + + align:start position:0% +our say band limited by pi I have to +tell you so band limited means means + + align:start position:0% +tell you so band limited means means + + + align:start position:0% +tell you so band limited means means +that there's some limit on the band and + + align:start position:0% +that there's some limit on the band and + + + align:start position:0% +that there's some limit on the band and +our interest is when that limit is the + + align:start position:0% +our interest is when that limit is the + + + align:start position:0% +our interest is when that limit is the +Nyquist frequency the one we don't want + + align:start position:0% +Nyquist frequency the one we don't want + + + align:start position:0% +Nyquist frequency the one we don't want +to allow so we we this is the point so + + align:start position:0% +to allow so we we this is the point so + + + align:start position:0% +to allow so we we this is the point so +this will be the idea that that if we + + align:start position:0% +this will be the idea that that if we + + + align:start position:0% +this will be the idea that that if we +take + + align:start position:0% +take + + + align:start position:0% +take +this class of + + align:start position:0% +this class of + + + align:start position:0% +this class of +functions that band limited that those + + align:start position:0% +functions that band limited that those + + + align:start position:0% +functions that band limited that those +are called ban limited functions and + + align:start position:0% +are called ban limited functions and + + + align:start position:0% +are called ban limited functions and +they're ban limited specifically by the + + align:start position:0% +they're ban limited specifically by the + + + align:start position:0% +they're ban limited specifically by the +Nyquist limit if we take those then the + + align:start position:0% +Nyquist limit if we take those then the + + + align:start position:0% +Nyquist limit if we take those then the +idea is that + + align:start position:0% +idea is that + + + align:start position:0% +idea is that +the the only the only one then then we + + align:start position:0% +the the only the only one then then we + + + align:start position:0% +the the only the only one then then we +can reconstruct from the samples because + + align:start position:0% +can reconstruct from the samples because + + + align:start position:0% +can reconstruct from the samples because +the only function that has zero samples + + align:start position:0% +the only function that has zero samples + + + align:start position:0% +the only function that has zero samples +in that class is the zero function you + + align:start position:0% +in that class is the zero function you + + + align:start position:0% +in that class is the zero function you +see that class has knocked out has not + + align:start position:0% +see that class has knocked out has not + + + align:start position:0% +see that class has knocked out has not +allowing these + + align:start position:0% +allowing these + + + align:start position:0% +allowing these +guys of course haven't proved anything + + align:start position:0% +guys of course haven't proved anything + + + align:start position:0% +guys of course haven't proved anything +yet and I haven't shown how to + + align:start position:0% +yet and I haven't shown how to + + + align:start position:0% +yet and I haven't shown how to +reconstruct well of course we quickly + + align:start position:0% +reconstruct well of course we quickly + + + align:start position:0% +reconstruct well of course we quickly +reconstructed the zero function out of + + align:start position:0% +reconstructed the zero function out of + + + align:start position:0% +reconstructed the zero function out of +those zeros but now let me take + + align:start position:0% +those zeros but now let me take + + + align:start position:0% +those zeros but now let me take +another obviously important possible + + align:start position:0% +another obviously important possible + + + align:start position:0% +another obviously important possible +sample suppose I get zero samples except + + align:start position:0% +sample suppose I get zero samples except + + + align:start position:0% +sample suppose I get zero samples except +at that point where it's + + align:start position:0% + + + + align:start position:0% + +one okay now the question is what + + align:start position:0% + + + + align:start position:0% + +function f ofx + + align:start position:0% +function f ofx + + + align:start position:0% +function f ofx +on can I fill in in between 000000 1 + + align:start position:0% +on can I fill in in between 000000 1 + + + align:start position:0% +on can I fill in in between 000000 1 +0000 0 can I fill in exactly one + + align:start position:0% +0000 0 can I fill in exactly one + + + align:start position:0% +0000 0 can I fill in exactly one +function and that comes from this + + align:start position:0% +function and that comes from this + + + align:start position:0% +function and that comes from this +class so that I have now the answer for + + align:start position:0% +class so that I have now the answer for + + + align:start position:0% +class so that I have now the answer for +this highly important sample the sample + + align:start position:0% +this highly important sample the sample + + + align:start position:0% +this highly important sample the sample +that's all zeros except for the Delta + + align:start position:0% +that's all zeros except for the Delta + + + align:start position:0% +that's all zeros except for the Delta +sample you could say okay so I'm looking + + align:start position:0% +sample you could say okay so I'm looking + + + align:start position:0% +sample you could say okay so I'm looking +for the function now which is one at + + align:start position:0% +for the function now which is one at + + + align:start position:0% +for the function now which is one at +that point and zero at the others so + + align:start position:0% +that point and zero at the others so + + + align:start position:0% +that point and zero at the others so +here's a key + + align:start position:0% +here's a key + + + align:start position:0% +here's a key +function uh and you I'll show you what + + align:start position:0% +function uh and you I'll show you what + + + align:start position:0% +function uh and you I'll show you what +it is so the the function this function + + align:start position:0% +it is so the the function this function + + + align:start position:0% +it is so the the function this function +that I going to mention will get down + + align:start position:0% +that I going to mention will get down + + + align:start position:0% +that I going to mention will get down +here it'll oscillate it'll it'll go + + align:start position:0% +here it'll oscillate it'll it'll go + + + align:start position:0% +here it'll oscillate it'll it'll go +forever it's it's not like a + + align:start position:0% +forever it's it's not like a + + + align:start position:0% +forever it's it's not like a +spline + + align:start position:0% + + + + align:start position:0% + +splines splines made it to zero and + + align:start position:0% +splines splines made it to zero and + + + align:start position:0% +splines splines made it to zero and +stayed there right the cubic splines for + + align:start position:0% +stayed there right the cubic splines for + + + align:start position:0% +stayed there right the cubic splines for +example okay but + + align:start position:0% +example okay but + + + align:start position:0% +example okay but +um I guess yeah we that somehow that + + align:start position:0% +um I guess yeah we that somehow that + + + align:start position:0% +um I guess yeah we that somehow that +functioned we're not in that League + + align:start position:0% +functioned we're not in that League + + + align:start position:0% +functioned we're not in that League +we're in this band limited league in a + + align:start position:0% +we're in this band limited league in a + + + align:start position:0% +we're in this band limited league in a +way you could say + + align:start position:0% +way you could say + + + align:start position:0% +way you could say +that I mean + + align:start position:0% +that I mean + + + align:start position:0% +that I mean +when what is what's the key connection + + align:start position:0% +when what is what's the key connection + + + align:start position:0% +when what is what's the key connection +between drop off of the 4A transform so + + align:start position:0% +between drop off of the 4A transform so + + + align:start position:0% +between drop off of the 4A transform so +if the 4A transform drops off fast what + + align:start position:0% +if the 4A transform drops off fast what + + + align:start position:0% +if the 4A transform drops off fast what +does that tell me about the + + align:start position:0% +does that tell me about the + + + align:start position:0% +does that tell me about the +function it's smooth thanks that's + + align:start position:0% +function it's smooth thanks that's + + + align:start position:0% +function it's smooth thanks that's +exactly the right word if the 4A + + align:start position:0% +exactly the right word if the 4A + + + align:start position:0% +exactly the right word if the 4A +transform drops off fast the function is + + align:start position:0% +transform drops off fast the function is + + + align:start position:0% +transform drops off fast the function is +smooth okay this is really the ex an + + align:start position:0% +smooth okay this is really the ex an + + + align:start position:0% +smooth okay this is really the ex an +extreme case that it's dropped + + align:start position:0% +extreme case that it's dropped + + + align:start position:0% +extreme case that it's dropped +off totally you know it's not just Decay + + align:start position:0% +off totally you know it's not just Decay + + + align:start position:0% +off totally you know it's not just Decay +rate it's just zunk out uh Beyond this + + align:start position:0% +rate it's just zunk out uh Beyond this + + + align:start position:0% +rate it's just zunk out uh Beyond this +band of + + align:start position:0% +band of + + + align:start position:0% +band of +frequencies and uh so that gives you + + align:start position:0% +frequencies and uh so that gives you + + + align:start position:0% +frequencies and uh so that gives you +could say sort of a hypers smooth + + align:start position:0% +could say sort of a hypers smooth + + + align:start position:0% +could say sort of a hypers smooth +function I mean so smooth that you know + + align:start position:0% +function I mean so smooth that you know + + + align:start position:0% +function I mean so smooth that you know +everything by knowing these samples okay + + align:start position:0% +everything by knowing these samples okay + + + align:start position:0% +everything by knowing these samples okay +now I'm ready to write down the the the + + align:start position:0% +now I'm ready to write down the the the + + + align:start position:0% +now I'm ready to write down the the the +the key function a famous function that + + align:start position:0% +the key function a famous function that + + + align:start position:0% +the key function a famous function that +has those samples and that function is + + align:start position:0% +has those samples and that function is + + + align:start position:0% +has those samples and that function is +s pi x over + + align:start position:0% + + + + align:start position:0% + +pix I don't know if you ever thought + + align:start position:0% +pix I don't know if you ever thought + + + align:start position:0% +pix I don't know if you ever thought +about this function and it has a name do + + align:start position:0% +about this function and it has a name do + + + align:start position:0% +about this function and it has a name do +you know its name Sync It's the sync + + align:start position:0% +you know its name Sync It's the sync + + + align:start position:0% +you know its name Sync It's the sync +function which is a little you know the + + align:start position:0% +function which is a little you know the + + + align:start position:0% +function which is a little you know the +name's a little + + align:start position:0% +name's a little + + + align:start position:0% +name's a little +unfortunate mainly because you know + + align:start position:0% +unfortunate mainly because you know + + + align:start position:0% +unfortunate mainly because you know +you're using those same letters s i n + + align:start position:0% +you're using those same letters s i n + + + align:start position:0% +you're using those same letters s i n +but it's a c that turns it that gives it + + align:start position:0% +but it's a c that turns it that gives it + + + align:start position:0% +but it's a c that turns it that gives it +means so this is called the sync + + align:start position:0% +means so this is called the sync + + + align:start position:0% +means so this is called the sync +function sync of X but but uh the main + + align:start position:0% +function sync of X but but uh the main + + + align:start position:0% +function sync of X but but uh the main +thing is its formula okay well everybody + + align:start position:0% +thing is its formula okay well everybody + + + align:start position:0% +thing is its formula okay well everybody +sees that at xal 1 the S of Pi is Zer at + + align:start position:0% +sees that at xal 1 the S of Pi is Zer at + + + align:start position:0% +sees that at xal 1 the S of Pi is Zer at +xal 2 the sign of Pi is zero all the + + align:start position:0% +xal 2 the sign of Pi is zero all the + + + align:start position:0% +xal 2 the sign of Pi is zero all the +these ones we've seen already and now + + align:start position:0% +these ones we've seen already and now + + + align:start position:0% +these ones we've seen already and now +what happens at x equals z do you + + align:start position:0% +what happens at x equals z do you + + + align:start position:0% +what happens at x equals z do you +recognize that this function as X goes + + align:start position:0% +recognize that this function as X goes + + + align:start position:0% +recognize that this function as X goes +to Zer is perfectly good function I mean + + align:start position:0% +to Zer is perfectly good function I mean + + + align:start position:0% +to Zer is perfectly good function I mean +it's has it it becomes 0 over Z at x + + align:start position:0% +it's has it it becomes 0 over Z at x + + + align:start position:0% +it's has it it becomes 0 over Z at x +equals 0 but the limit we know to be one + + align:start position:0% +equals 0 but the limit we know to be one + + + align:start position:0% +equals 0 but the limit we know to be one +right the S of theta over Theta is one + + align:start position:0% +right the S of theta over Theta is one + + + align:start position:0% +right the S of theta over Theta is one +as you as Theta approaches zero right so + + align:start position:0% +as you as Theta approaches zero right so + + + align:start position:0% +as you as Theta approaches zero right so +so that it does have that correct sample + + align:start position:0% +so that it does have that correct sample + + + align:start position:0% +so that it does have that correct sample +and now what's the I claim that that is + + align:start position:0% +and now what's the I claim that that is + + + align:start position:0% +and now what's the I claim that that is +a band limited function and you'll see + + align:start position:0% +a band limited function and you'll see + + + align:start position:0% +a band limited function and you'll see +that that function + + align:start position:0% +that that function + + + align:start position:0% +that that function +uh pushes the limit it's right you know + + align:start position:0% +uh pushes the limit it's right you know + + + align:start position:0% +uh pushes the limit it's right you know +nyz barely lets it in so what is the + + align:start position:0% +nyz barely lets it in so what is the + + + align:start position:0% +nyz barely lets it in so what is the +what is now here's a calculation so this + + align:start position:0% +what is now here's a calculation so this + + + align:start position:0% +what is now here's a calculation so this +is our practice what is f of K for that + + align:start position:0% +is our practice what is f of K for that + + + align:start position:0% +is our practice what is f of K for that +uh for that + + align:start position:0% + + + + align:start position:0% + +function H now let me think how to do + + align:start position:0% +function H now let me think how to do + + + align:start position:0% +function H now let me think how to do +this one so I want to I want to compute + + align:start position:0% +this one so I want to I want to compute + + + align:start position:0% +this one so I want to I want to compute +the just to understand this this better + + align:start position:0% +the just to understand this this better + + + align:start position:0% +the just to understand this this better +I want to see that that is a band + + align:start position:0% +I want to see that that is a band + + + align:start position:0% +I want to see that that is a band +limited function and what what is its + + align:start position:0% +limited function and what what is its + + + align:start position:0% +limited function and what what is its +fora + + align:start position:0% +fora + + + align:start position:0% +fora +transform okay now once again here we + + align:start position:0% +transform okay now once again here we + + + align:start position:0% +transform okay now once again here we +have a function where I if I want to do + + align:start position:0% +have a function where I if I want to do + + + align:start position:0% +have a function where I if I want to do +you have to how best to do + + align:start position:0% +you have to how best to do + + + align:start position:0% +you have to how best to do +this you could say well just uh just um + + align:start position:0% +this you could say well just uh just um + + + align:start position:0% +this you could say well just uh just um +do + + align:start position:0% +do + + + align:start position:0% +do +it as I would say on the quiz you know + + align:start position:0% +it as I would say on the quiz you know + + + align:start position:0% +it as I would say on the quiz you know +just go ahead and do it but you'll + + align:start position:0% +just go ahead and do it but you'll + + + align:start position:0% +just go ahead and do it but you'll +see uh I'm going to have a problem I + + align:start position:0% +see uh I'm going to have a problem I + + + align:start position:0% +see uh I'm going to have a problem I +think so I would but this gives us a + + align:start position:0% +think so I would but this gives us a + + + align:start position:0% +think so I would but this gives us a +chance to remember the formula so what's + + align:start position:0% +chance to remember the formula so what's + + + align:start position:0% +chance to remember the formula so what's +the formula for the fora integral + + align:start position:0% +the formula for the fora integral + + + align:start position:0% +the formula for the fora integral +transform of this particular so I my + + align:start position:0% +transform of this particular so I my + + + align:start position:0% +transform of this particular so I my +function is the sync function sin pix + + align:start position:0% +function is the sync function sin pix + + + align:start position:0% +function is the sync function sin pix +over sin pix what's the so how do I get + + align:start position:0% +over sin pix what's the so how do I get + + + align:start position:0% +over sin pix what's the so how do I get +it I do a do a what here e to the minus + + align:start position:0% +it I do a do a what here e to the minus + + + align:start position:0% +it I do a do a what here e to the minus +I KX and am I doing DX or DK DX right + + align:start position:0% +I KX and am I doing DX or DK DX right + + + align:start position:0% +I KX and am I doing DX or DK DX right +and I'm going from minus infinity to + + align:start position:0% +and I'm going from minus infinity to + + + align:start position:0% +and I'm going from minus infinity to +infinity and am I do I have a two + + align:start position:0% +infinity and am I do I have a two + + + align:start position:0% +infinity and am I do I have a two +Pi yes or no I don't who knows anyway + + align:start position:0% +Pi yes or no I don't who knows anyway + + + align:start position:0% +Pi yes or no I don't who knows anyway +right + + align:start position:0% +right + + + align:start position:0% +right +uh in the book I didn't okay good okay + + align:start position:0% +uh in the book I didn't okay good okay + + + align:start position:0% +uh in the book I didn't okay good okay +now + + align:start position:0% +now + + + align:start position:0% +now +well I don't know the answer + + align:start position:0% +well I don't know the answer + + + align:start position:0% +well I don't know the answer +here but so let's it's much better to + + align:start position:0% +here but so let's it's much better to + + + align:start position:0% +here but so let's it's much better to +start with the answer right and and and + + align:start position:0% +start with the answer right and and and + + + align:start position:0% +start with the answer right and and and +check that that it so so let me say what + + align:start position:0% +check that that it so so let me say what + + + align:start position:0% +check that that it so so let me say what +I think the answer is I think the answer + + align:start position:0% +I think the answer is I think the answer + + + align:start position:0% +I think the answer is I think the answer +is it's a + + align:start position:0% +is it's a + + + align:start position:0% +is it's a +function that's exactly it it it it it + + align:start position:0% +function that's exactly it it it it it + + + align:start position:0% +function that's exactly it it it it it +as I say it pushes the limit from this + + align:start position:0% +as I say it pushes the limit from this + + + align:start position:0% +as I say it pushes the limit from this +is the this is K it it's it's the it's + + align:start position:0% +is the this is K it it's it's the it's + + + align:start position:0% +is the this is K it it's it's the it's +the square + + align:start position:0% +the square + + + align:start position:0% +the square +wave zero the height is one it's the + + align:start position:0% +wave zero the height is one it's the + + + align:start position:0% +wave zero the height is one it's the +it's the function that's zero all the + + align:start position:0% +it's the function that's zero all the + + + align:start position:0% +it's the function that's zero all the +way here all the way there I think that + + align:start position:0% +way here all the way there I think that + + + align:start position:0% +way here all the way there I think that +that's the free transform of that + + align:start position:0% +that's the free transform of that + + + align:start position:0% +that's the free transform of that +function and and just before we check it + + align:start position:0% +function and and just before we check it + + + align:start position:0% +function and and just before we check it +uh see how Nyquist got really pushed up + + align:start position:0% +uh see how Nyquist got really pushed up + + + align:start position:0% +uh see how Nyquist got really pushed up +to the wall here right because because + + align:start position:0% +to the wall here right because because + + + align:start position:0% +to the wall here right because because +the frequency is + + align:start position:0% +the frequency is + + + align:start position:0% +the frequency is +nonzero right all the way to Pi + + align:start position:0% +nonzero right all the way to Pi + + + align:start position:0% +nonzero right all the way to Pi +but it you know there Pi is just one + + align:start position:0% +but it you know there Pi is just one + + + align:start position:0% +but it you know there Pi is just one +point there and anyway I think we won't + + align:start position:0% +point there and anyway I think we won't + + + align:start position:0% +point there and anyway I think we won't +get into H philosophical discussion + + align:start position:0% +get into H philosophical discussion + + + align:start position:0% +get into H philosophical discussion +about whether you know is that is that + + align:start position:0% +about whether you know is that is that + + + align:start position:0% +about whether you know is that is that +limited to pie I don't know whether to + + align:start position:0% +limited to pie I don't know whether to + + + align:start position:0% +limited to pie I don't know whether to +put you saw me chickening out here I + + align:start position:0% +put you saw me chickening out here I + + + align:start position:0% +put you saw me chickening out here I +didn't know whether to put less or equal + + align:start position:0% +didn't know whether to put less or equal + + + align:start position:0% +didn't know whether to put less or equal +or not I still don't uh it's but it's + + align:start position:0% +or not I still don't uh it's but it's + + + align:start position:0% +or not I still don't uh it's but it's +this is making the point that that's the + + align:start position:0% +this is making the point that that's the + + + align:start position:0% +this is making the point that that's the +key uh frequency so this particular + + align:start position:0% +key uh frequency so this particular + + + align:start position:0% +key uh frequency so this particular +function what I'm saying is this + + align:start position:0% +function what I'm saying is this + + + align:start position:0% +function what I'm saying is this +particular function has all the + + align:start position:0% +particular function has all the + + + align:start position:0% +particular function has all the +frequencies in equal amounts over a band + + align:start position:0% +frequencies in equal amounts over a band + + + align:start position:0% +frequencies in equal amounts over a band +and no and nothing outside that band and + + align:start position:0% +and no and nothing outside that band and + + + align:start position:0% +and no and nothing outside that band and +that and that's the nist band okay now + + align:start position:0% +that and that's the nist band okay now + + + align:start position:0% +that and that's the nist band okay now +why is this the correct answer here I + + align:start position:0% +why is this the correct answer here I + + + align:start position:0% +why is this the correct answer here I +guess the smart + + align:start position:0% +guess the smart + + + align:start position:0% +guess the smart +way would + + align:start position:0% +way would + + + align:start position:0% +way would +be take the this is a good function easy + + align:start position:0% +be take the this is a good function easy + + + align:start position:0% +be take the this is a good function easy +function so let's take + + align:start position:0% +function so let's take + + + align:start position:0% +function so let's take +the let's go take the transform in the + + align:start position:0% +the let's go take the transform in the + + + align:start position:0% +the let's go take the transform in the +other direction start from here and get + + align:start position:0% +other direction start from here and get + + + align:start position:0% +other direction start from here and get +to here right that that would be + + align:start position:0% +to here right that that would be + + + align:start position:0% +to here right that that would be +convincing because we're we we do know + + align:start position:0% +convincing because we're we we do know + + + align:start position:0% +convincing because we're we we do know +that that those that pair of formulas + + align:start position:0% +that that those that pair of formulas + + + align:start position:0% +that that those that pair of formulas +for f connected to F hat connected to F + + align:start position:0% +for f connected to F hat connected to F + + + align:start position:0% +for f connected to F hat connected to F +uh you know they go together so if if I + + align:start position:0% +uh you know they go together so if if I + + + align:start position:0% +uh you know they go together so if if I +can show that uh that go that I go from + + align:start position:0% +can show that uh that go that I go from + + + align:start position:0% +can show that uh that go that I go from +here that the that 4A integral takes me + + align:start position:0% +here that the that 4A integral takes me + + + align:start position:0% +here that the that 4A integral takes me +from here to there then this guy will + + align:start position:0% +from here to there then this guy will + + + align:start position:0% +from here to there then this guy will +take me back so let me just do that + + align:start position:0% +take me back so let me just do that + + + align:start position:0% +take me back so let me just do that +because that's a very very important uh + + align:start position:0% +because that's a very very important uh + + + align:start position:0% +because that's a very very important uh +one that you should like be prepared for + + align:start position:0% +one that you should like be prepared for + + + align:start position:0% +one that you should like be prepared for +right so so now what do I want to do + + align:start position:0% +right so so now what do I want to do + + + align:start position:0% +right so so now what do I want to do +here's my function of + + align:start position:0% + + + + align:start position:0% + +K and so I put this is my function of K + + align:start position:0% +K and so I put this is my function of K + + + align:start position:0% +K and so I put this is my function of K +now I'm I'm I'm hoping that I Rec whoops + + align:start position:0% +now I'm I'm I'm hoping that I Rec whoops + + + align:start position:0% +now I'm I'm I'm hoping that I Rec whoops +now what do I do when I want to do the + + align:start position:0% +now what do I do when I want to do the + + + align:start position:0% +now what do I do when I want to do the +do the transform in the opposite + + align:start position:0% +do the transform in the opposite + + + align:start position:0% +do the transform in the opposite +direction + + align:start position:0% +direction + + + align:start position:0% +direction +it'll be an e to the plus IX right d + + align:start position:0% +it'll be an e to the plus IX right d + + + align:start position:0% +it'll be an e to the plus IX right d +what DK now from K from minus infinity + + align:start position:0% +what DK now from K from minus infinity + + + align:start position:0% +what DK now from K from minus infinity +to infinity and now I think I do put in + + align:start position:0% +to infinity and now I think I do put in + + + align:start position:0% +to infinity and now I think I do put in +the two Pi is that right now and and the + + align:start position:0% +the two Pi is that right now and and the + + + align:start position:0% +the two Pi is that right now and and the +question is does that bring back the + + align:start position:0% +question is does that bring back the + + + align:start position:0% +question is does that bring back the +sync function if it does then this was + + align:start position:0% +sync function if it does then this was + + + align:start position:0% +sync function if it does then this was +okay in the other direction right if if + + align:start position:0% +okay in the other direction right if if + + + align:start position:0% +okay in the other direction right if if +the transform is correct in One + + align:start position:0% +the transform is correct in One + + + align:start position:0% +the transform is correct in One +Direction then the inverse transform + + align:start position:0% +Direction then the inverse transform + + + align:start position:0% +Direction then the inverse transform +will be correct so I just plan to do + + align:start position:0% +will be correct so I just plan to do + + + align:start position:0% +will be correct so I just plan to do +this integral now what's the the F of K + + align:start position:0% +this integral now what's the the F of K + + + align:start position:0% +this integral now what's the the F of K +of course it's an easy integral now F + + align:start position:0% +of course it's an easy integral now F + + + align:start position:0% +of course it's an easy integral now F +hat of K + + align:start position:0% +hat of K + + + align:start position:0% +hat of K +is one over between minus pi and Pi so I + + align:start position:0% +is one over between minus pi and Pi so I + + + align:start position:0% +is one over between minus pi and Pi so I +only have to do over that range where F + + align:start position:0% +only have to do over that range where F + + + align:start position:0% +only have to do over that range where F +of K is just a + + align:start position:0% + + + + align:start position:0% + +one and now that's an integral we can + + align:start position:0% +one and now that's an integral we can + + + align:start position:0% +one and now that's an integral we can +certainly do so I have 1 over 2 + + align:start position:0% +certainly do so I have 1 over 2 + + + align:start position:0% +certainly do so I have 1 over 2 +pi integrating e to the i k X will give + + align:start position:0% +pi integrating e to the i k X will give + + + align:start position:0% +pi integrating e to the i k X will give +me e to the I KX over iix now remember + + align:start position:0% +me e to the I KX over iix now remember + + + align:start position:0% +me e to the I KX over iix now remember +I'm integrating DK oh look see we we're + + align:start position:0% +I'm integrating DK oh look see we we're + + + align:start position:0% +I'm integrating DK oh look see we we're +showing this x now in the denominator + + align:start position:0% +showing this x now in the denominator + + + align:start position:0% +showing this x now in the denominator +that we we're hoping for uh and now I + + align:start position:0% +that we we're hoping for uh and now I + + + align:start position:0% +that we we're hoping for uh and now I +have to do that between K is minus pi + + align:start position:0% +have to do that between K is minus pi + + + align:start position:0% +have to do that between K is minus pi +and + + align:start position:0% +and + + + align:start position:0% +and +Pi so this is like so so I get 1 over 2 + + align:start position:0% +Pi so this is like so so I get 1 over 2 + + + align:start position:0% +Pi so this is like so so I get 1 over 2 +pi e to the I + + align:start position:0% +pi e to the I + + + align:start position:0% +pi e to the I +pix minus E to the minus I pix right + + align:start position:0% +pix minus E to the minus I pix right + + + align:start position:0% +pix minus E to the minus I pix right +over the + + align:start position:0% +over the + + + align:start position:0% +over the +iix okay so + + align:start position:0% +iix okay so + + + align:start position:0% +iix okay so +far I was doing a k integral and I get + + align:start position:0% +far I was doing a k integral and I get + + + align:start position:0% +far I was doing a k integral and I get +an X answer and I want to be sure that + + align:start position:0% +an X answer and I want to be sure that + + + align:start position:0% +an X answer and I want to be sure that +this x answer is this is the X answer I + + align:start position:0% +this x answer is this is the X answer I + + + align:start position:0% +this x answer is this is the X answer I +want it's the sync function okay it is + + align:start position:0% +want it's the sync function okay it is + + + align:start position:0% +want it's the sync function okay it is +right the I recognize the sign uh e to + + align:start position:0% +right the I recognize the sign uh e to + + + align:start position:0% +right the I recognize the sign uh e to +the e to the I Theta minus E to the + + align:start position:0% +the e to the I Theta minus E to the + + + align:start position:0% +the e to the I Theta minus E to the +minus I Theta divided by two I guess is + + align:start position:0% +minus I Theta divided by two I guess is + + + align:start position:0% +minus I Theta divided by two I guess is +the sign this right so I have one over 2 + + align:start position:0% +the sign this right so I have one over 2 + + + align:start position:0% +the sign this right so I have one over 2 +pi and here's the here's the iix well no + + align:start position:0% +pi and here's the here's the iix well no + + + align:start position:0% +pi and here's the here's the iix well no +the I is part of that sign trick so I'm + + align:start position:0% +the I is part of that sign trick so I'm + + + align:start position:0% +the I is part of that sign trick so I'm +just using the fact that e to the I + + align:start position:0% +just using the fact that e to the I + + + align:start position:0% +just using the fact that e to the I +Theta minus E the minus I + + align:start position:0% +Theta minus E the minus I + + + align:start position:0% +Theta minus E the minus I +Theta is that's this is cosine plus I + + align:start position:0% +Theta is that's this is cosine plus I + + + align:start position:0% +Theta is that's this is cosine plus I +sign subtract Co sign but subtract minus + + align:start position:0% +sign subtract Co sign but subtract minus + + + align:start position:0% +sign subtract Co sign but subtract minus +I sign so that will be 2 I sin + + align:start position:0% +I sign so that will be 2 I sin + + + align:start position:0% +I sign so that will be 2 I sin +Theta right that's we all know and now + + align:start position:0% +Theta right that's we all know and now + + + align:start position:0% +Theta right that's we all know and now +Theta is Theta is pix here so I have two + + align:start position:0% +Theta is Theta is pix here so I have two + + + align:start position:0% +Theta is Theta is pix here so I have two +let me keep the I there and 2 I sin pix + + align:start position:0% +let me keep the I there and 2 I sin pix + + + align:start position:0% +let me keep the I there and 2 I sin pix +you see it + + align:start position:0% +you see it + + + align:start position:0% +you see it +works just using this replacing this by + + align:start position:0% +works just using this replacing this by + + + align:start position:0% +works just using this replacing this by +the sign the two cancels the two the I + + align:start position:0% +the sign the two cancels the two the I + + + align:start position:0% +the sign the two cancels the two the I +canc cans the I and I have sin pix over + + align:start position:0% +canc cans the I and I have sin pix over + + + align:start position:0% +canc cans the I and I have sin pix over +pix that I that the sync function okay + + align:start position:0% +pix that I that the sync function okay + + + align:start position:0% +pix that I that the sync function okay +so that's the that's the + + align:start position:0% + + + + align:start position:0% + +function we've now checked so we've + + align:start position:0% +function we've now checked so we've + + + align:start position:0% +function we've now checked so we've +checked two things about this function + + align:start position:0% +checked two things about this function + + + align:start position:0% +checked two things about this function +it has the right samples 0 0000 0 one at + + align:start position:0% +it has the right samples 0 0000 0 one at + + + align:start position:0% +it has the right samples 0 0000 0 one at +x equals 0 and then back to zeros it is + + align:start position:0% +x equals 0 and then back to zeros it is + + + align:start position:0% +x equals 0 and then back to zeros it is +band limited so it's the guy if this was + + align:start position:0% +band limited so it's the guy if this was + + + align:start position:0% +band limited so it's the guy if this was +my sample if this was my f of n 00 1 0 + + align:start position:0% +my sample if this was my f of n 00 1 0 + + + align:start position:0% +my sample if this was my f of n 00 1 0 +z0 then I've got it it's it's the uh the + + align:start position:0% +z0 then I've got it it's it's the uh the + + + align:start position:0% +z0 then I've got it it's it's the uh the +right uh + + align:start position:0% +right uh + + + align:start position:0% +right uh +function okay now can now we can create + + align:start position:0% +function okay now can now we can create + + + align:start position:0% +function okay now can now we can create +Channon sampling formula Shannon + + align:start position:0% +Channon sampling formula Shannon + + + align:start position:0% +Channon sampling formula Shannon +sampling formula gives me the F ofx for + + align:start position:0% +sampling formula gives me the F ofx for + + + align:start position:0% +sampling formula gives me the F ofx for +for any F + + align:start position:0% +for any F + + + align:start position:0% +for any F +ofn maybe you can spot that now so this + + align:start position:0% +ofn maybe you can spot that now so this + + + align:start position:0% +ofn maybe you can spot that now so this +is going to use this shift in variance + + align:start position:0% +is going to use this shift in variance + + + align:start position:0% +is going to use this shift in variance +oh yeah let's tell me what + + align:start position:0% +oh yeah let's tell me what + + + align:start position:0% +oh yeah let's tell me what +the let's take one step here suppose my + + align:start position:0% +the let's take one step here suppose my + + + align:start position:0% +the let's take one step here suppose my +f of n's were z00 Z zero and a one there + + align:start position:0% +f of n's were z00 Z zero and a one there + + + align:start position:0% +f of n's were z00 Z zero and a one there +so suppose this is you and for the exam + + align:start position:0% +so suppose this is you and for the exam + + + align:start position:0% +so suppose this is you and for the exam +to this idea of shifting is is simple + + align:start position:0% +to this idea of shifting is is simple + + + align:start position:0% +to this idea of shifting is is simple +and basic and it's a great thing to be + + align:start position:0% +and basic and it's a great thing to be + + + align:start position:0% +and basic and it's a great thing to be +able to do so what would be this + + align:start position:0% +able to do so what would be this + + + align:start position:0% +able to do so what would be this +wouldn't be the right answer that that + + align:start position:0% +wouldn't be the right answer that that + + + align:start position:0% +wouldn't be the right answer that that +function produced the one at zero tell + + align:start position:0% +function produced the one at zero tell + + + align:start position:0% +function produced the one at zero tell +me what + + align:start position:0% +me what + + + align:start position:0% +me what +function copying this idea will produce + + align:start position:0% +function copying this idea will produce + + + align:start position:0% +function copying this idea will produce +all zeros except for a one at this + + align:start position:0% +all zeros except for a one at this + + + align:start position:0% +all zeros except for a one at this +point so so I + + align:start position:0% +point so so I + + + align:start position:0% +point so so I +I'll put this question over here suppose + + align:start position:0% +I'll put this question over here suppose + + + align:start position:0% +I'll put this question over here suppose +I'm all zero at that point but at this + + align:start position:0% +I'm all zero at that point but at this + + + align:start position:0% +I'm all zero at that point but at this +point I'm up and and then I go back to + + align:start position:0% +point I'm up and and then I go back to + + + align:start position:0% +point I'm up and and then I go back to +zeros what function is giving me + + align:start position:0% + + + + align:start position:0% + +that you see it does Decay because of + + align:start position:0% +that you see it does Decay because of + + + align:start position:0% +that you see it does Decay because of +the X in the denominator it kind of it + + align:start position:0% +the X in the denominator it kind of it + + + align:start position:0% +the X in the denominator it kind of it +goes to zero but not very fast okay + + align:start position:0% +goes to zero but not very fast okay + + + align:start position:0% +goes to zero but not very fast okay +what's that + + align:start position:0% + + + + align:start position:0% + +function I replace X by xus one right I + + align:start position:0% +function I replace X by xus one right I + + + align:start position:0% +function I replace X by xus one right I +replace so the function here is s of pi + + align:start position:0% +replace so the function here is s of pi + + + align:start position:0% +replace so the function here is s of pi +x -1 / Pi x -1 I just changed the X to x + + align:start position:0% +x -1 / Pi x -1 I just changed the X to x + + + align:start position:0% +x -1 / Pi x -1 I just changed the X to x +- 1 now again at xal 0 this is sin Pi + + align:start position:0% +- 1 now again at xal 0 this is sin Pi + + + align:start position:0% +- 1 now again at xal 0 this is sin Pi +sin minus Pi it's safely zero but at x + + align:start position:0% +sin minus Pi it's safely zero but at x + + + align:start position:0% +sin minus Pi it's safely zero but at x +equal 1 that's now the point where I'm + + align:start position:0% +equal 1 that's now the point where I'm + + + align:start position:0% +equal 1 that's now the point where I'm +getting Z over zero so it get and it + + align:start position:0% +getting Z over zero so it get and it + + + align:start position:0% +getting Z over zero so it get and it +then the numbers are right to give me + + align:start position:0% +then the numbers are right to give me + + + align:start position:0% +then the numbers are right to give me +the exact answer one okay so now we see + + align:start position:0% +the exact answer one okay so now we see + + + align:start position:0% +the exact answer one okay so now we see +what to do if the samples sampling + + align:start position:0% +what to do if the samples sampling + + + align:start position:0% +what to do if the samples sampling +turned out to give us this answer and + + align:start position:0% +turned out to give us this answer and + + + align:start position:0% +turned out to give us this answer and +now can you tell me the whole formul + + align:start position:0% +now can you tell me the whole formul + + + align:start position:0% +now can you tell me the whole formul +fora can can you tell me the whole + + align:start position:0% +fora can can you tell me the whole + + + align:start position:0% +fora can can you tell me the whole +formula so now I'm ready for Shannon's + + align:start position:0% +formula so now I'm ready for Shannon's + + + align:start position:0% +formula so now I'm ready for Shannon's +sampling theorem is that F + + align:start position:0% +sampling theorem is that F + + + align:start position:0% +sampling theorem is that F +ofx that if f ofx is band + + align:start position:0% +ofx that if f ofx is band + + + align:start position:0% +ofx that if f ofx is band +limited then I can tell you what it is + + align:start position:0% +limited then I can tell you what it is + + + align:start position:0% +limited then I can tell you what it is +at all X so so going back to the + + align:start position:0% +at all X so so going back to the + + + align:start position:0% +at all X so so going back to the +beginning of this lecture it's a + + align:start position:0% +beginning of this lecture it's a + + + align:start position:0% +beginning of this lecture it's a +miracle that this is possible that I'll + + align:start position:0% +miracle that this is possible that I'll + + + align:start position:0% +miracle that this is possible that I'll +that we can write down a formula for f + + align:start position:0% +that we can write down a formula for f + + + align:start position:0% +that we can write down a formula for f +ofx at all X only using F of + + align:start position:0% +ofx at all X only using F of + + + align:start position:0% +ofx at all X only using F of +n's okay now it's going to be a + + align:start position:0% +n's okay now it's going to be a + + + align:start position:0% +n's okay now it's going to be a +sum from n equal minus infinity to + + align:start position:0% +sum from n equal minus infinity to + + + align:start position:0% +sum from n equal minus infinity to +Infinity because I'm going to use all + + align:start position:0% +Infinity because I'm going to use all + + + align:start position:0% +Infinity because I'm going to use all +the F of n's to produce the F ofx and + + align:start position:0% +the F of n's to produce the F ofx and + + + align:start position:0% +the F of n's to produce the F ofx and +now what do I put in + + align:start position:0% +now what do I put in + + + align:start position:0% +now what do I put in +there so I want my formula to be + + align:start position:0% +there so I want my formula to be + + + align:start position:0% +there so I want my formula to be +correct + + align:start position:0% +correct + + + align:start position:0% +correct +when I want my formula to be correct in + + align:start position:0% +when I want my formula to be correct in + + + align:start position:0% +when I want my formula to be correct in +this + + align:start position:0% +this + + + align:start position:0% +this +case when and so that if if all the fs + + align:start position:0% +case when and so that if if all the fs + + + align:start position:0% +case when and so that if if all the fs +were zero except for the middle one then + + align:start position:0% +were zero except for the middle one then + + + align:start position:0% +were zero except for the middle one then +I want to put sin pix over pix in there + + align:start position:0% +I want to put sin pix over pix in there + + + align:start position:0% +I want to put sin pix over pix in there +the sync function if I also want to get + + align:start position:0% +the sync function if I also want to get + + + align:start position:0% +the sync function if I also want to get +this one right if all the fs are zero so + + align:start position:0% +this one right if all the fs are zero so + + + align:start position:0% +this one right if all the fs are zero so +there will only be one term if this is + + align:start position:0% +there will only be one term if this is + + + align:start position:0% +there will only be one term if this is +the term I want that to show up okay + + align:start position:0% +the term I want that to show up okay + + + align:start position:0% +the term I want that to show up okay +what do I what do I yeah you can tell me + + align:start position:0% +what do I what do I yeah you can tell me + + + align:start position:0% +what do I what do I yeah you can tell me +suppose this is hitting at n yeah let's + + align:start position:0% +suppose this is hitting at n yeah let's + + + align:start position:0% +suppose this is hitting at n yeah let's +we'll we just fix this and then you'll + + align:start position:0% +we'll we just fix this and then you'll + + + align:start position:0% +we'll we just fix this and then you'll +see it suppose that all the others n n + + align:start position:0% +see it suppose that all the others n n + + + align:start position:0% +see it suppose that all the others n n +minus one n+ one all those it's zero but + + align:start position:0% +minus one n+ one all those it's zero but + + + align:start position:0% +minus one n+ one all those it's zero but +at x equal n it's one now what should I + + align:start position:0% +at x equal n it's one now what should I + + + align:start position:0% +at x equal n it's one now what should I +have chosen what what's the correct I'm + + align:start position:0% +have chosen what what's the correct I'm + + + align:start position:0% +have chosen what what's the correct I'm +just going to make it easy for all of us + + align:start position:0% +just going to make it easy for all of us + + + align:start position:0% +just going to make it easy for all of us +to guess uh what What's the what's the + + align:start position:0% +to guess uh what What's the what's the + + + align:start position:0% +to guess uh what What's the what's the +good sync function which Peaks at a + + align:start position:0% +good sync function which Peaks at a + + + align:start position:0% +good sync function which Peaks at a +point + + align:start position:0% +point + + + align:start position:0% +point +n again I'm just shifting it over so + + align:start position:0% +n again I'm just shifting it over so + + + align:start position:0% +n again I'm just shifting it over so +what do I + + align:start position:0% +what do I + + + align:start position:0% +what do I +do put in what do I write here + + align:start position:0% +do put in what do I write here + + + align:start position:0% +do put in what do I write here +n i shift the whole thing by n so that's + + align:start position:0% +n i shift the whole thing by n so that's + + + align:start position:0% +n i shift the whole thing by n so that's +the right answer when this hits at n so + + align:start position:0% +the right answer when this hits at n so + + + align:start position:0% +the right answer when this hits at n so +now you maybe you see that this is going + + align:start position:0% +now you maybe you see that this is going + + + align:start position:0% +now you maybe you see that this is going +to be the right right answer for all of + + align:start position:0% + + + + align:start position:0% + +them you see that we're just you we're + + align:start position:0% +them you see that we're just you we're + + + align:start position:0% +them you see that we're just you we're +using linearity and shift in variance + + align:start position:0% +using linearity and shift in variance + + + align:start position:0% +using linearity and shift in variance +the shift in variance is telling us this + + align:start position:0% +the shift in variance is telling us this + + + align:start position:0% +the shift in variance is telling us this +this answer for wherever the one hits + + align:start position:0% +this answer for wherever the one hits + + + align:start position:0% +this answer for wherever the one hits +that that's what we need and then by + + align:start position:0% +that that's what we need and then by + + + align:start position:0% +that that's what we need and then by +linearity I put together the whatever + + align:start position:0% +linearity I put together the whatever + + + align:start position:0% +linearity I put together the whatever +the f is at that point that would just + + align:start position:0% +the f is at that point that would just + + + align:start position:0% +the f is at that point that would just +amplify the sync and then I have to put + + align:start position:0% +amplify the sync and then I have to put + + + align:start position:0% +amplify the sync and then I have to put +them in for all the other values that's + + align:start position:0% +them in for all the other values that's + + + align:start position:0% +them in for all the other values that's +the Shannon formula that's the Shannon + + align:start position:0% +the Shannon formula that's the Shannon + + + align:start position:0% +the Shannon formula that's the Shannon +formula that that and this function is + + align:start position:0% +formula that that and this function is + + + align:start position:0% +formula that that and this function is +band limited uh let's see what's the oh + + align:start position:0% +band limited uh let's see what's the oh + + + align:start position:0% +band limited uh let's see what's the oh +yeah what's the uh do I do you see that + + align:start position:0% +yeah what's the uh do I do you see that + + + align:start position:0% +yeah what's the uh do I do you see that +this one that this guy is Ban limited we + + align:start position:0% +this one that this guy is Ban limited we + + + align:start position:0% +this one that this guy is Ban limited we +we checked right we checked that this + + align:start position:0% +we checked right we checked that this + + + align:start position:0% +we checked right we checked that this +one sin pix over pix that was band + + align:start position:0% +one sin pix over pix that was band + + + align:start position:0% +one sin pix over pix that was band +limited because we actually found the + + align:start position:0% +limited because we actually found the + + + align:start position:0% +limited because we actually found the +band now I just gives us another chance + + align:start position:0% +band now I just gives us another chance + + + align:start position:0% +band now I just gives us another chance +to think aloud what's the forier + + align:start position:0% +to think aloud what's the forier + + + align:start position:0% +to think aloud what's the forier +transform of this guy my my claim is + + align:start position:0% +transform of this guy my my claim is + + + align:start position:0% +transform of this guy my my claim is +that it's also in this band + + align:start position:0% +that it's also in this band + + + align:start position:0% +that it's also in this band +nonzero only in the band and zero + + align:start position:0% +nonzero only in the band and zero + + + align:start position:0% +nonzero only in the band and zero +outside the outside the Nyquist band + + align:start position:0% +outside the outside the Nyquist band + + + align:start position:0% +outside the outside the Nyquist band +what is the transform of + + align:start position:0% +what is the transform of + + + align:start position:0% +what is the transform of +that what happens if you shift a + + align:start position:0% +that what happens if you shift a + + + align:start position:0% +that what happens if you shift a +function what happens to its + + align:start position:0% +function what happens to its + + + align:start position:0% +function what happens to its +transform so that's a that's a good + + align:start position:0% +transform so that's a that's a good + + + align:start position:0% +transform so that's a that's a good +that's a one of the key rules that makes + + align:start position:0% +that's a one of the key rules that makes + + + align:start position:0% +that's a one of the key rules that makes +uh Fier so special is that if I shift if + + align:start position:0% +uh Fier so special is that if I shift if + + + align:start position:0% +uh Fier so special is that if I shift if +I if I I took this sign let me write + + align:start position:0% +I if I I took this sign let me write + + + align:start position:0% +I if I I took this sign let me write +this guy again + + align:start position:0% +this guy again + + + align:start position:0% +this guy again +this was the unshifted one that had this + + align:start position:0% +this was the unshifted one that had this + + + align:start position:0% +this was the unshifted one that had this +trans that that connected to the what + + align:start position:0% +trans that that connected to the what + + + align:start position:0% +trans that that connected to the what +what am I going to call that the + + align:start position:0% + + + + align:start position:0% + +Box function the Box function the square + + align:start position:0% +Box function the Box function the square + + + align:start position:0% +Box function the Box function the square +wave well box is good uh + + align:start position:0% +wave well box is good uh + + + align:start position:0% +wave well box is good uh +now what if I shift that function if I + + align:start position:0% +now what if I shift that function if I + + + align:start position:0% +now what if I shift that function if I +shift a function what happens to this 4 + + align:start position:0% +shift a function what happens to this 4 + + + align:start position:0% +shift a function what happens to this 4 +a + + align:start position:0% +a + + + align:start position:0% +a +transform anybody + + align:start position:0% +transform anybody + + + align:start position:0% +transform anybody +remember you multiply it by + + align:start position:0% +remember you multiply it by + + + align:start position:0% +remember you multiply it by +so so if I shift the + + align:start position:0% +so so if I shift the + + + align:start position:0% +so so if I shift the +function I just multiply this box + + align:start position:0% +function I just multiply this box + + + align:start position:0% +function I just multiply this box +function this is a box function in the K + + align:start position:0% +function this is a box function in the K + + + align:start position:0% +function this is a box function in the K +times something e to + + align:start position:0% +times something e to + + + align:start position:0% +times something e to +the + + align:start position:0% +the + + + align:start position:0% +the +I shift and the shift was + + align:start position:0% +I shift and the shift was + + + align:start position:0% +I shift and the shift was +one + + align:start position:0% +one + + + align:start position:0% +one +right is it just e to the i + + align:start position:0% +right is it just e to the i + + + align:start position:0% +right is it just e to the i +k d being the shift distance oh the + + align:start position:0% +k d being the shift distance oh the + + + align:start position:0% +k d being the shift distance oh the +shift distance was + + align:start position:0% +shift distance was + + + align:start position:0% +shift distance was +n right and possibly minus who knows + + align:start position:0% +n right and possibly minus who knows + + + align:start position:0% +n right and possibly minus who knows +right okay but what's the point here the + + align:start position:0% +right okay but what's the point here the + + + align:start position:0% +right okay but what's the point here the +point is that it's still zero outside + + align:start position:0% +point is that it's still zero outside + + + align:start position:0% +point is that it's still zero outside +the box Inside the Box instead of being + + align:start position:0% +the box Inside the Box instead of being + + + align:start position:0% +the box Inside the Box instead of being +one it's it's this complex guy but no no + + align:start position:0% +one it's it's this complex guy but no no + + + align:start position:0% +one it's it's this complex guy but no no +change it's still zero outside the box + + align:start position:0% +change it's still zero outside the box + + + align:start position:0% +change it's still zero outside the box +it's still band limited so this is the + + align:start position:0% +it's still band limited so this is the + + + align:start position:0% +it's still band limited so this is the +the transform of this guy and then the + + align:start position:0% +the transform of this guy and then the + + + align:start position:0% +the transform of this guy and then the +transform of this combination would be + + align:start position:0% +transform of this combination would be + + + align:start position:0% +transform of this combination would be +uh still in the box multiplied by + + align:start position:0% +uh still in the box multiplied by + + + align:start position:0% +uh still in the box multiplied by +some messy expression so what was I + + align:start position:0% +some messy expression so what was I + + + align:start position:0% +some messy expression so what was I +doing there I was just checking that + + align:start position:0% +doing there I was just checking that + + + align:start position:0% +doing there I was just checking that +sure enough this guy is Ban limited and + + align:start position:0% +sure enough this guy is Ban limited and + + + align:start position:0% +sure enough this guy is Ban limited and +uh it's ban limited it gives us the + + align:start position:0% +uh it's ban limited it gives us the + + + align:start position:0% +uh it's ban limited it gives us the +right answer at the it gives us the + + align:start position:0% +right answer at the it gives us the + + + align:start position:0% +right answer at the it gives us the +right F of n's of course everybody sees + + align:start position:0% +right F of n's of course everybody sees + + + align:start position:0% +right F of n's of course everybody sees +that that that at x equal + + align:start position:0% + + + + align:start position:0% + +n let's just have a look now we've got + + align:start position:0% +n let's just have a look now we've got + + + align:start position:0% +n let's just have a look now we've got +this great formula plug in x equal n + + align:start position:0% +this great formula plug in x equal n + + + align:start position:0% +this great formula plug in x equal n +what happens when you plug in X at at + + align:start position:0% +what happens when you plug in X at at + + + align:start position:0% +what happens when you plug in X at at +one of the samples you look to see what + + align:start position:0% +one of the samples you look to see what + + + align:start position:0% +one of the samples you look to see what +this a a TOD converter produced at time + + align:start position:0% +this a a TOD converter produced at time + + + align:start position:0% +this a a TOD converter produced at time +n and let's just see so at x equal n the + + align:start position:0% +n and let's just see so at x equal n the + + + align:start position:0% +n and let's just see so at x equal n the +left side is f of n why is the right + + align:start position:0% +left side is f of n why is the right + + + align:start position:0% +left side is f of n why is the right +side F of that n that particular n maybe + + align:start position:0% +side F of that n that particular n maybe + + + align:start position:0% +side F of that n that particular n maybe +I should maybe I should give a specific + + align:start position:0% +I should maybe I should give a specific + + + align:start position:0% +I should maybe I should give a specific +letter to that n so at that particular + + align:start position:0% +letter to that n so at that particular + + + align:start position:0% +letter to that n so at that particular +sample this left side is f of N and I + + align:start position:0% +sample this left side is f of N and I + + + align:start position:0% +sample this left side is f of N and I +hope that the right side gives me f at + + align:start position:0% +hope that the right side gives me f at + + + align:start position:0% +hope that the right side gives me f at +that capital N that particular one why + + align:start position:0% +that capital N that particular one why + + + align:start position:0% +that capital N that particular one why +does it you're you're all seeing that + + align:start position:0% +does it you're you're all seeing that + + + align:start position:0% +does it you're you're all seeing that +that that at at x equal capital N these + + align:start position:0% +that that at at x equal capital N these + + + align:start position:0% +that that at at x equal capital N these +guys are all zero except for one of + + align:start position:0% +guys are all zero except for one of + + + align:start position:0% +guys are all zero except for one of +them except for the one when little n + + align:start position:0% +them except for the one when little n + + + align:start position:0% +them except for the one when little n +and capital N are the same then then + + align:start position:0% +and capital N are the same then then + + + align:start position:0% +and capital N are the same then then +that becomes the one and I'm getting F + + align:start position:0% +that becomes the one and I'm getting F + + + align:start position:0% +that becomes the one and I'm getting F +at capital N so so it'll give me that + + align:start position:0% +at capital N so so it'll give me that + + + align:start position:0% +at capital N so so it'll give me that +for for the N equal one the one term + + align:start position:0% +for for the N equal one the one term + + + align:start position:0% +for for the N equal one the one term +yeah okay I I don't know if it was + + align:start position:0% +yeah okay I I don't know if it was + + + align:start position:0% +yeah okay I I don't know if it was +necessary to say that you've got the + + align:start position:0% +necessary to say that you've got the + + + align:start position:0% +necessary to say that you've got the +idea of this sampling formula okay + + align:start position:0% +idea of this sampling formula okay + + + align:start position:0% +idea of this sampling formula okay +um yeah I I I could say more about the + + align:start position:0% +um yeah I I I could say more about the + + + align:start position:0% +um yeah I I I could say more about the +sampling just + + align:start position:0% +sampling just + + + align:start position:0% +sampling just +uh you know just to realize that that + + align:start position:0% +uh you know just to realize that that + + + align:start position:0% +uh you know just to realize that that +sort of why the + + align:start position:0% + + + + align:start position:0% + +technology people communication theory + + align:start position:0% +technology people communication theory + + + align:start position:0% +technology people communication theory +is always trying to like have a w a + + align:start position:0% +is always trying to like have a w a + + + align:start position:0% +is always trying to like have a w a +greater + + align:start position:0% +greater + + + align:start position:0% +greater +bandwidth you always want a greater + + align:start position:0% +bandwidth you always want a greater + + + align:start position:0% +bandwidth you always want a greater +bandwidth but if the bandwidth which is + + align:start position:0% +bandwidth but if the bandwidth which is + + + align:start position:0% +bandwidth but if the bandwidth which is +this is increased well by the way what + + align:start position:0% +this is increased well by the way what + + + align:start position:0% +this is increased well by the way what +does happen suppose it's band limited by + + align:start position:0% +does happen suppose it's band limited by + + + align:start position:0% +does happen suppose it's band limited by +pi o by by some by pi pi over T suppose + + align:start position:0% +pi o by by some by pi pi over T suppose + + + align:start position:0% +pi o by by some by pi pi over T suppose +I can + + align:start position:0% +I can + + + align:start position:0% +I can +yeah let's + + align:start position:0% +yeah let's + + + align:start position:0% +yeah let's +just I normalized things to choose + + align:start position:0% +just I normalized things to choose + + + align:start position:0% +just I normalized things to choose +samples every + + align:start position:0% +samples every + + + align:start position:0% +samples every +integer one 0 one two 3 and that turned + + align:start position:0% +integer one 0 one two 3 and that turned + + + align:start position:0% +integer one 0 one two 3 and that turned +out that the Nyquist frequency was Pi + + align:start position:0% +out that the Nyquist frequency was Pi + + + align:start position:0% +out that the Nyquist frequency was Pi +now what what sampling rate + + align:start position:0% +now what what sampling rate + + + align:start position:0% +now what what sampling rate +would would correspond to this + + align:start position:0% +would would correspond to this + + + align:start position:0% +would would correspond to this +uh band which could be well let me just + + align:start position:0% +uh band which could be well let me just + + + align:start position:0% +uh band which could be well let me just +say what it is that would that would be + + align:start position:0% +say what it is that would that would be + + + align:start position:0% +say what it is that would that would be +the Nyquist frequency for sampling every + + align:start position:0% +the Nyquist frequency for sampling every + + + align:start position:0% +the Nyquist frequency for sampling every +t uh instead of a sampling interval of + + align:start position:0% +t uh instead of a sampling interval of + + + align:start position:0% +t uh instead of a sampling interval of +of of of one if I sample every T to T 3 + + align:start position:0% +of of of one if I sample every T to T 3 + + + align:start position:0% +of of of one if I sample every T to T 3 +T minus t my sampling rate is T so if T + + align:start position:0% +T minus t my sampling rate is T so if T + + + align:start position:0% +T minus t my sampling rate is T so if T +is + + align:start position:0% +is + + + align:start position:0% +is +small I'm sampling much more suppose T + + align:start position:0% +small I'm sampling much more suppose T + + + align:start position:0% +small I'm sampling much more suppose T +is one qu if T is one quarter then I'm + + align:start position:0% +is one qu if T is one quarter then I'm + + + align:start position:0% +is one qu if T is one quarter then I'm +doing four + + align:start position:0% +doing four + + + align:start position:0% +doing four +samplings I'm taking four samples I'm + + align:start position:0% +samplings I'm taking four samples I'm + + + align:start position:0% +samplings I'm taking four samples I'm +I'm paying more for this a to converter + + align:start position:0% +I'm paying more for this a to converter + + + align:start position:0% +I'm paying more for this a to converter +because it's taking four samples where + + align:start position:0% +because it's taking four samples where + + + align:start position:0% +because it's taking four samples where +previously it took one what's the what's + + align:start position:0% +previously it took one what's the what's + + + align:start position:0% +previously it took one what's the what's +the how do I get paid back what's the + + align:start position:0% +the how do I get paid back what's the + + + align:start position:0% +the how do I get paid back what's the +reward the reward is if T is one quarter + + align:start position:0% +reward the reward is if T is one quarter + + + align:start position:0% +reward the reward is if T is one quarter +then the the Nyquist limit is four Pi I + + align:start position:0% +then the the Nyquist limit is four Pi I + + + align:start position:0% +then the the Nyquist limit is four Pi I +can get a broader band of signals by + + align:start position:0% +can get a broader band of signals by + + + align:start position:0% +can get a broader band of signals by +sampling them more often every just let + + align:start position:0% +sampling them more often every just let + + + align:start position:0% +sampling them more often every just let +me just say that again because it's + + align:start position:0% +me just say that again because it's + + + align:start position:0% +me just say that again because it's +that's the fundamental idea behind it if + + align:start position:0% +that's the fundamental idea behind it if + + + align:start position:0% +that's the fundamental idea behind it if +I sample more often say so fast sampling + + align:start position:0% +I sample more often say so fast sampling + + + align:start position:0% +I sample more often say so fast sampling +would be small fast samples would be + + align:start position:0% +would be small fast samples would be + + + align:start position:0% +would be small fast samples would be +small + + align:start position:0% +small + + + align:start position:0% +small +T small + + align:start position:0% +T small + + + align:start position:0% +T small +T and then a higher + + align:start position:0% +T and then a higher + + + align:start position:0% +T and then a higher +Nyquist a higher band limited more more + + align:start position:0% +Nyquist a higher band limited more more + + + align:start position:0% +Nyquist a higher band limited more more +functions allowed if I sample more often + + align:start position:0% +functions allowed if I sample more often + + + align:start position:0% +functions allowed if I sample more often +I'm I'm I'm able to catch on to more + + align:start position:0% +I'm I'm I'm able to catch on to more + + + align:start position:0% +I'm I'm I'm able to catch on to more +functions if I + + align:start position:0% +functions if I + + + align:start position:0% +functions if I +sample and that's what I mean now + + align:start position:0% +sample and that's what I mean now + + + align:start position:0% +sample and that's what I mean now +Communications want wide bands and this + + align:start position:0% +Communications want wide bands and this + + + align:start position:0% +Communications want wide bands and this +is where uh they get limited I mean this + + align:start position:0% +is where uh they get limited I mean this + + + align:start position:0% +is where uh they get limited I mean this +is where this is the this is the you + + align:start position:0% +is where this is the this is the you + + + align:start position:0% +is where this is the this is the you +could say the fundamental I don't know + + align:start position:0% +could say the fundamental I don't know + + + align:start position:0% +could say the fundamental I don't know +whether to say physical limit sort of + + align:start position:0% +whether to say physical limit sort of + + + align:start position:0% +whether to say physical limit sort of +maybe Fier limit on uh sampling theory + + align:start position:0% +maybe Fier limit on uh sampling theory + + + align:start position:0% +maybe Fier limit on uh sampling theory +is exactly this nist frequency okay + + align:start position:0% +is exactly this nist frequency okay + + + align:start position:0% +is exactly this nist frequency okay +questions or or discussion about that + + align:start position:0% +questions or or discussion about that + + + align:start position:0% +questions or or discussion about that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +uh enough so that's a uh that's an + + align:start position:0% +uh enough so that's a uh that's an + + + align:start position:0% +uh enough so that's a uh that's an +example that allowed us to do a lot of + + align:start position:0% +example that allowed us to do a lot of + + + align:start position:0% +example that allowed us to do a lot of +things + + align:start position:0% +things + + + align:start position:0% +things +uh okay yeah I I did want to ask for + + align:start position:0% +uh okay yeah I I did want to ask for + + + align:start position:0% +uh okay yeah I I did want to ask for +your help doing these evaluations let me + + align:start position:0% +your help doing these evaluations let me + + + align:start position:0% +your help doing these evaluations let me +say what I'm going to do this + + align:start position:0% +say what I'm going to do this + + + align:start position:0% +say what I'm going to do this +afternoon I'm going to answer all all + + align:start position:0% +afternoon I'm going to answer all all + + + align:start position:0% +afternoon I'm going to answer all all +the questions I can and I planned when + + align:start position:0% +the questions I can and I planned when + + + align:start position:0% +the questions I can and I planned when +there is a pause and nobody else asks I + + align:start position:0% +there is a pause and nobody else asks I + + + align:start position:0% +there is a pause and nobody else asks I +plan to compute the uh fora + + align:start position:0% +plan to compute the uh fora + + + align:start position:0% +plan to compute the uh fora +integral and for a series say fora + + align:start position:0% +integral and for a series say fora + + + align:start position:0% +integral and for a series say fora +series for uh a function that has that + + align:start position:0% +series for uh a function that has that + + + align:start position:0% +series for uh a function that has that +has uh it's going to be like the one + + align:start position:0% +has uh it's going to be like the one + + + align:start position:0% +has uh it's going to be like the one +today except this is going to be have + + align:start position:0% +today except this is going to be have + + + align:start position:0% +today except this is going to be have +have have a height of one over h and a + + align:start position:0% +have have a height of one over h and a + + + align:start position:0% +have have a height of one over h and a +width of H uh so that so that's if if in + + align:start position:0% +width of H uh so that so that's if if in + + + align:start position:0% +width of H uh so that so that's if if in +case you're not uh able to be here this + + align:start position:0% +case you're not uh able to be here this + + + align:start position:0% +case you're not uh able to be here this +afternoon I thought I'd just say in + + align:start position:0% +afternoon I thought I'd just say in + + + align:start position:0% +afternoon I thought I'd just say in +advance what calculations I thought I + + align:start position:0% +advance what calculations I thought I + + + align:start position:0% +advance what calculations I thought I +would do so there's a particular + + align:start position:0% +would do so there's a particular + + + align:start position:0% +would do so there's a particular +function f + + align:start position:0% +function f + + + align:start position:0% +function f +ofx it happens to be an even function + + align:start position:0% +ofx it happens to be an even function + + + align:start position:0% +ofx it happens to be an even function +we'll compute its for8 coefficients and + + align:start position:0% +we'll compute its for8 coefficients and + + + align:start position:0% +we'll compute its for8 coefficients and +we'll let H go to + + align:start position:0% +we'll let H go to + + + align:start position:0% +we'll let H go to +zero to see what happens it's just a + + align:start position:0% +zero to see what happens it's just a + + + align:start position:0% +zero to see what happens it's just a +good example that you may have seen on + + align:start position:0% +good example that you may have seen on + + + align:start position:0% +good example that you may have seen on +older exams + + align:start position:0% +older exams + + + align:start position:0% +older exams +okay well can I just say personal word + + align:start position:0% +okay well can I just say personal word + + + align:start position:0% +okay well can I just say personal word +before I pass out so + + align:start position:0% +before I pass out so + + + align:start position:0% +before I pass out so +evaluations if you're willing to help + + align:start position:0% +evaluations if you're willing to help + + + align:start position:0% +evaluations if you're willing to help +and just leave them on the table would + + align:start position:0% +and just leave them on the table would + + + align:start position:0% +and just leave them on the table would +be much appreciated I'll stretch out the + + align:start position:0% +be much appreciated I'll stretch out the + + + align:start position:0% +be much appreciated I'll stretch out the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +homeworks uh I just want to say I've + + align:start position:0% +homeworks uh I just want to say I've + + + align:start position:0% +homeworks uh I just want to say I've +enjoyed teaching you guys very much + + align:start position:0% +enjoyed teaching you guys very much + + + align:start position:0% +enjoyed teaching you guys very much +thank you all and + + align:start position:0% + + + + align:start position:0% + +uh thanks \ No newline at end of file diff --git a/J9-3p_J9o2Y.txt b/J9-3p_J9o2Y.txt new file mode 100644 index 0000000000000000000000000000000000000000..e3973149d7b5f84806a5076b3d8afda5c5098693 --- /dev/null +++ b/J9-3p_J9o2Y.txt @@ -0,0 +1,683 @@ +align:start position:0% + +in this video we'll design the + + align:start position:0% +in this video we'll design the + + + align:start position:0% +in this video we'll design the +optimization problem that the operating + + align:start position:0% +optimization problem that the operating + + + align:start position:0% +optimization problem that the operating +room manager would + + align:start position:0% +room manager would + + + align:start position:0% +room manager would +the decision to be made is how many + + align:start position:0% +the decision to be made is how many + + + align:start position:0% +the decision to be made is how many +operating rooms to assign each + + align:start position:0% +operating rooms to assign each + + + align:start position:0% +operating rooms to assign each +department on each day this means that + + align:start position:0% +department on each day this means that + + + align:start position:0% +department on each day this means that +we need to define integer decision + + align:start position:0% +we need to define integer decision + + + align:start position:0% +we need to define integer decision +variables x JK x JK will represent the + + align:start position:0% +variables x JK x JK will represent the + + + align:start position:0% +variables x JK x JK will represent the +number of operating rooms department j + + align:start position:0% +number of operating rooms department j + + + align:start position:0% +number of operating rooms department j +is allocated on day k so here J can take + + align:start position:0% +is allocated on day k so here J can take + + + align:start position:0% +is allocated on day k so here J can take +values such as ophthalmology gynecology + + align:start position:0% +values such as ophthalmology gynecology + + + align:start position:0% +values such as ophthalmology gynecology +general surgery and so on whereas K + + align:start position:0% +general surgery and so on whereas K + + + align:start position:0% +general surgery and so on whereas K +would take values like Monday Tuesday + + align:start position:0% +would take values like Monday Tuesday + + + align:start position:0% +would take values like Monday Tuesday +Wednesday and so on the objective of + + align:start position:0% +Wednesday and so on the objective of + + + align:start position:0% +Wednesday and so on the objective of +this problem will be to maximize the + + align:start position:0% +this problem will be to maximize the + + + align:start position:0% +this problem will be to maximize the +percent of target allocation hours that + + align:start position:0% +percent of target allocation hours that + + + align:start position:0% +percent of target allocation hours that +each department is actually allocated so + + align:start position:0% +each department is actually allocated so + + + align:start position:0% +each department is actually allocated so +if target allocation hours are TJ for + + align:start position:0% +if target allocation hours are TJ for + + + align:start position:0% +if target allocation hours are TJ for +department J then we want to maximize + + align:start position:0% +department J then we want to maximize + + + align:start position:0% +department J then we want to maximize +the sum of eight times xj k divided by + + align:start position:0% +the sum of eight times xj k divided by + + + align:start position:0% +the sum of eight times xj k divided by +TJ over all departments and days of the + + align:start position:0% +TJ over all departments and days of the + + + align:start position:0% +TJ over all departments and days of the +week let's break this down + + align:start position:0% +week let's break this down + + + align:start position:0% +week let's break this down +for example if Otolaryngology has a + + align:start position:0% +for example if Otolaryngology has a + + + align:start position:0% +for example if Otolaryngology has a +target of thirty seven point three hours + + align:start position:0% +target of thirty seven point three hours + + + align:start position:0% +target of thirty seven point three hours +per week + + align:start position:0% +per week + + + align:start position:0% +per week +that means TJ equals to thirty seven + + align:start position:0% +that means TJ equals to thirty seven + + + align:start position:0% +that means TJ equals to thirty seven +point three and we allocate them for + + align:start position:0% +point three and we allocate them for + + + align:start position:0% +point three and we allocate them for +operating rooms then their percent of + + align:start position:0% +operating rooms then their percent of + + + align:start position:0% +operating rooms then their percent of +target allocation hours is equal to + + align:start position:0% +target allocation hours is equal to + + + align:start position:0% +target allocation hours is equal to +eight times four that is they got 32 + + align:start position:0% +eight times four that is they got 32 + + + align:start position:0% +eight times four that is they got 32 +hours divided by the thirty seven point + + align:start position:0% +hours divided by the thirty seven point + + + align:start position:0% +hours divided by the thirty seven point +three hours they asked for + + align:start position:0% +three hours they asked for + + + align:start position:0% +three hours they asked for +so they got eighty five point eight + + align:start position:0% +so they got eighty five point eight + + + align:start position:0% +so they got eighty five point eight +percent of what they wanted and we try + + align:start position:0% +percent of what they wanted and we try + + + align:start position:0% +percent of what they wanted and we try +to maximize this percentage value for + + align:start position:0% +to maximize this percentage value for + + + align:start position:0% +to maximize this percentage value for +every department so that's why we sum + + align:start position:0% +every department so that's why we sum + + + align:start position:0% +every department so that's why we sum +over all departments and all days of the + + align:start position:0% +over all departments and all days of the + + + align:start position:0% +over all departments and all days of the +week + + align:start position:0% + + + + align:start position:0% + +let's continue on to the constraints + + align:start position:0% +let's continue on to the constraints + + + align:start position:0% +let's continue on to the constraints +remember that Mount Sinai has 10 + + align:start position:0% +remember that Mount Sinai has 10 + + + align:start position:0% +remember that Mount Sinai has 10 +operating rooms therefore at most 10 + + align:start position:0% +operating rooms therefore at most 10 + + + align:start position:0% +operating rooms therefore at most 10 +operating rooms can be assigned on any + + align:start position:0% +operating rooms can be assigned on any + + + align:start position:0% +operating rooms can be assigned on any +given day also the number of operating + + align:start position:0% +given day also the number of operating + + + align:start position:0% +given day also the number of operating +rooms allocated to a department on a + + align:start position:0% +rooms allocated to a department on a + + + align:start position:0% +rooms allocated to a department on a +given day cannot exceed the number of + + align:start position:0% +given day cannot exceed the number of + + + align:start position:0% +given day cannot exceed the number of +surgery teams that the department has + + align:start position:0% +surgery teams that the department has + + + align:start position:0% +surgery teams that the department has +available that day and as we said before + + align:start position:0% +available that day and as we said before + + + align:start position:0% +available that day and as we said before +we must meet Department daily minimums + + align:start position:0% +we must meet Department daily minimums + + + align:start position:0% +we must meet Department daily minimums +and maximums as well as weekly minimums + + align:start position:0% +and maximums as well as weekly minimums + + + align:start position:0% +and maximums as well as weekly minimums +and maximums let's turn these + + align:start position:0% +and maximums let's turn these + + + align:start position:0% +and maximums let's turn these +constraints into math so the first + + align:start position:0% +constraints into math so the first + + + align:start position:0% +constraints into math so the first +constraint is that at most 10 operating + + align:start position:0% +constraint is that at most 10 operating + + + align:start position:0% +constraint is that at most 10 operating +rooms can be assigned on any given day + + align:start position:0% +rooms can be assigned on any given day + + + align:start position:0% +rooms can be assigned on any given day +let's consider Monday for example that + + align:start position:0% +let's consider Monday for example that + + + align:start position:0% +let's consider Monday for example that +means that X for ophthalmology on Monday + + align:start position:0% +means that X for ophthalmology on Monday + + + align:start position:0% +means that X for ophthalmology on Monday +plus X for gynecology on Monday plus X + + align:start position:0% +plus X for gynecology on Monday plus X + + + align:start position:0% +plus X for gynecology on Monday plus X +per oral surgery on Monday plus expert + + align:start position:0% +per oral surgery on Monday plus expert + + + align:start position:0% +per oral surgery on Monday plus expert +Otolaryngology on Monday plus X for + + align:start position:0% +Otolaryngology on Monday plus X for + + + align:start position:0% +Otolaryngology on Monday plus X for +general surgery on Monday must add up to + + align:start position:0% +general surgery on Monday must add up to + + + align:start position:0% +general surgery on Monday must add up to +something less than or equal to 10 we + + align:start position:0% +something less than or equal to 10 we + + + align:start position:0% +something less than or equal to 10 we +would have a similar constraint for + + align:start position:0% +would have a similar constraint for + + + align:start position:0% +would have a similar constraint for +Tuesday Wednesday Thursday and Friday + + align:start position:0% +Tuesday Wednesday Thursday and Friday + + + align:start position:0% +Tuesday Wednesday Thursday and Friday +the next set of constraints is that the + + align:start position:0% +the next set of constraints is that the + + + align:start position:0% +the next set of constraints is that the +number of operating rooms allocated to a + + align:start position:0% +number of operating rooms allocated to a + + + align:start position:0% +number of operating rooms allocated to a +department on a given day cannot exceed + + align:start position:0% +department on a given day cannot exceed + + + align:start position:0% +department on a given day cannot exceed +the number of surgery teams that are + + align:start position:0% +the number of surgery teams that are + + + align:start position:0% +the number of surgery teams that are +available that day so for example for + + align:start position:0% +available that day so for example for + + + align:start position:0% +available that day so for example for +gynecology on Friday there are 3 teams + + align:start position:0% +gynecology on Friday there are 3 teams + + + align:start position:0% +gynecology on Friday there are 3 teams +available that means that X gynecology + + align:start position:0% +available that means that X gynecology + + + align:start position:0% +available that means that X gynecology +Friday must be between 0 & 3 for oral + + align:start position:0% +Friday must be between 0 & 3 for oral + + + align:start position:0% +Friday must be between 0 & 3 for oral +surgery on Wednesday it must be between + + align:start position:0% +surgery on Wednesday it must be between + + + align:start position:0% +surgery on Wednesday it must be between +0 & 0 because the oral surgeon is only + + align:start position:0% +0 & 0 because the oral surgeon is only + + + align:start position:0% +0 & 0 because the oral surgeon is only +in on Tuesdays and Thursdays the next + + align:start position:0% +in on Tuesdays and Thursdays the next + + + align:start position:0% +in on Tuesdays and Thursdays the next +set of constraints is that we must meet + + align:start position:0% +set of constraints is that we must meet + + + align:start position:0% +set of constraints is that we must meet +Department daily minimums and maximums + + align:start position:0% +Department daily minimums and maximums + + + align:start position:0% +Department daily minimums and maximums +for example the general surgery + + align:start position:0% +for example the general surgery + + + align:start position:0% +for example the general surgery +department on Tuesday requires between 0 + + align:start position:0% +department on Tuesday requires between 0 + + + align:start position:0% +department on Tuesday requires between 0 +and 6 operating rooms we would have a + + align:start position:0% +and 6 operating rooms we would have a + + + align:start position:0% +and 6 operating rooms we would have a +similar constraint for every department + + align:start position:0% +similar constraint for every department + + + align:start position:0% +similar constraint for every department +and for every day of the week we also + + align:start position:0% +and for every day of the week we also + + + align:start position:0% +and for every day of the week we also +need to meet Department weekly minimums + + align:start position:0% +need to meet Department weekly minimums + + + align:start position:0% +need to meet Department weekly minimums +and maximums so for example the + + align:start position:0% +and maximums so for example the + + + align:start position:0% +and maximums so for example the +ophthalmology department has a minimum + + align:start position:0% +ophthalmology department has a minimum + + + align:start position:0% +ophthalmology department has a minimum +of 3 and a maximum of 6 operating rooms + + align:start position:0% +of 3 and a maximum of 6 operating rooms + + + align:start position:0% +of 3 and a maximum of 6 operating rooms +that + + align:start position:0% +that + + + align:start position:0% +that +means in any given week \ No newline at end of file diff --git a/JBIz7UadY5M.txt b/JBIz7UadY5M.txt new file mode 100644 index 0000000000000000000000000000000000000000..c69b099beb40b79b5b4983d197ab44ccae6504ce --- /dev/null +++ b/JBIz7UadY5M.txt @@ -0,0 +1,12536 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT + + align:start position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencourseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu IUS XI + + align:start position:0% + + + + align:start position:0% + +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +T okay I just pick whatever notation I + + align:start position:0% +T okay I just pick whatever notation I + + + align:start position:0% +T okay I just pick whatever notation I +want for my varable and let's say it's p + + align:start position:0% +want for my varable and let's say it's p + + + align:start position:0% +want for my varable and let's say it's p +it's + + align:start position:0% +it's + + + align:start position:0% +it's +t Okay so that's the least squares + + align:start position:0% +t Okay so that's the least squares + + + align:start position:0% +t Okay so that's the least squares +estimator and it turns out that as I + + align:start position:0% +estimator and it turns out that as I + + + align:start position:0% +estimator and it turns out that as I +said last time it's going to be + + align:start position:0% +said last time it's going to be + + + align:start position:0% +said last time it's going to be +convenient to think of those things as + + align:start position:0% +convenient to think of those things as + + + align:start position:0% +convenient to think of those things as +matrices all right so here I already + + align:start position:0% +matrices all right so here I already + + + align:start position:0% +matrices all right so here I already +have vectors right I've already gone + + align:start position:0% +have vectors right I've already gone + + + align:start position:0% +have vectors right I've already gone +from one dimension just real valed + + align:start position:0% +from one dimension just real valed + + + align:start position:0% +from one dimension just real valed +random variables to uh random vectors + + align:start position:0% +random variables to uh random vectors + + + align:start position:0% +random variables to uh random vectors +when I think of each XI but if I start + + align:start position:0% +when I think of each XI but if I start + + + align:start position:0% +when I think of each XI but if I start +stacking them together I'm going to have + + align:start position:0% +stacking them together I'm going to have + + + align:start position:0% +stacking them together I'm going to have +vectors and matrices that show up so the + + align:start position:0% +vectors and matrices that show up so the + + + align:start position:0% +vectors and matrices that show up so the +first Vector I'm getting is Y which is + + align:start position:0% +first Vector I'm getting is Y which is + + + align:start position:0% +first Vector I'm getting is Y which is +just the vector where have + + align:start position:0% +just the vector where have + + + align:start position:0% +just the vector where have +y1 to + + align:start position:0% +y1 to + + + align:start position:0% +y1 to +YN then I have uh so that's a bolt face + + align:start position:0% +YN then I have uh so that's a bolt face + + + align:start position:0% +YN then I have uh so that's a bolt face +Vector then I have X which is a matrix + + align:start position:0% +Vector then I have X which is a matrix + + + align:start position:0% +Vector then I have X which is a matrix +where I have uh well the first + + align:start position:0% +where I have uh well the first + + + align:start position:0% +where I have uh well the first +coordinate is Al always one okay so I + + align:start position:0% +coordinate is Al always one okay so I + + + align:start position:0% +coordinate is Al always one okay so I +have one and then um + + align:start position:0% +have one and then um + + + align:start position:0% +have one and then um +X1 x p minus one and that's sorry + + align:start position:0% +X1 x p minus one and that's sorry + + + align:start position:0% +X1 x p minus one and that's sorry +X1 XP minus one and that's for + + align:start position:0% +X1 XP minus one and that's for + + + align:start position:0% +X1 XP minus one and that's for +observation one and and then I have the + + align:start position:0% +observation one and and then I have the + + + align:start position:0% +observation one and and then I have the +same thing all the way down for + + align:start position:0% +same thing all the way down for + + + align:start position:0% +same thing all the way down for +observation + + align:start position:0% + + + + align:start position:0% + +n okay everybody understands what this + + align:start position:0% +n okay everybody understands what this + + + align:start position:0% +n okay everybody understands what this +is so I'm just basically stacking up all + + align:start position:0% +is so I'm just basically stacking up all + + + align:start position:0% +is so I'm just basically stacking up all +the x i right so this I + + align:start position:0% + + + + align:start position:0% + +throw is X I + + align:start position:0% +throw is X I + + + align:start position:0% +throw is X I +transpose right I'm just stacking them + + align:start position:0% +transpose right I'm just stacking them + + + align:start position:0% +transpose right I'm just stacking them +up and so if I want to rate all these + + align:start position:0% +up and so if I want to rate all these + + + align:start position:0% +up and so if I want to rate all these +things to be to be true for each of them + + align:start position:0% +things to be to be true for each of them + + + align:start position:0% +things to be to be true for each of them +all I need to do is to uh write the + + align:start position:0% +all I need to do is to uh write the + + + align:start position:0% +all I need to do is to uh write the +vector Epsilon which is Epsilon 1 to + + align:start position:0% +vector Epsilon which is Epsilon 1 to + + + align:start position:0% +vector Epsilon which is Epsilon 1 to +Epsilon n and what I'm going to have is + + align:start position:0% +Epsilon n and what I'm going to have is + + + align:start position:0% +Epsilon n and what I'm going to have is +that y the Boldt face Vector now is + + align:start position:0% +that y the Boldt face Vector now is + + + align:start position:0% +that y the Boldt face Vector now is +equal to the Matrix x times the vector + + align:start position:0% +equal to the Matrix x times the vector + + + align:start position:0% +equal to the Matrix x times the vector +beta plus the vector + + align:start position:0% +beta plus the vector + + + align:start position:0% +beta plus the vector +Epsilon okay and it's really just + + align:start position:0% +Epsilon okay and it's really just + + + align:start position:0% +Epsilon okay and it's really just +exactly saying what's there because for + + align:start position:0% +exactly saying what's there because for + + + align:start position:0% +exactly saying what's there because for +two so this is a vector right this is a + + align:start position:0% +two so this is a vector right this is a + + + align:start position:0% +two so this is a vector right this is a +vector and what what is the dimension of + + align:start position:0% +vector and what what is the dimension of + + + align:start position:0% +vector and what what is the dimension of +this vector + + align:start position:0% + + + + align:start position:0% + +n right so this is n + + align:start position:0% +n right so this is n + + + align:start position:0% +n right so this is n +observations and for all these for two + + align:start position:0% +observations and for all these for two + + + align:start position:0% +observations and for all these for two +vectors to be equal I need to have all + + align:start position:0% +vectors to be equal I need to have all + + + align:start position:0% +vectors to be equal I need to have all +the coordinates to be equal and that's + + align:start position:0% +the coordinates to be equal and that's + + + align:start position:0% +the coordinates to be equal and that's +exactly the same thing as saying that + + align:start position:0% +exactly the same thing as saying that + + + align:start position:0% +exactly the same thing as saying that +this holds for IAL 1 + + align:start position:0% + + + + align:start position:0% + +2N but now when I have this I can + + align:start position:0% +2N but now when I have this I can + + + align:start position:0% +2N but now when I have this I can +actually rewrite the sum for tals uh + + align:start position:0% +actually rewrite the sum for tals uh + + + align:start position:0% +actually rewrite the sum for tals uh +sorry for + + align:start position:0% +sorry for + + + align:start position:0% +sorry for +IAL 1 to n of y i + + align:start position:0% +IAL 1 to n of y i + + + align:start position:0% +IAL 1 to n of y i +minus X I transpose beta squ this is + + align:start position:0% +minus X I transpose beta squ this is + + + align:start position:0% +minus X I transpose beta squ this is +turns out to be equal to the ukian norm + + align:start position:0% +turns out to be equal to the ukian norm + + + align:start position:0% +turns out to be equal to the ukian norm +of the vector y minus the Matrix X Time + + align:start position:0% +of the vector y minus the Matrix X Time + + + align:start position:0% +of the vector y minus the Matrix X Time +beta squared okay and I'm going to put a + + align:start position:0% +beta squared okay and I'm going to put a + + + align:start position:0% +beta squared okay and I'm going to put a +two here so we know we're talking about + + align:start position:0% +two here so we know we're talking about + + + align:start position:0% +two here so we know we're talking about +the ukian norm right this just means + + align:start position:0% +the ukian norm right this just means + + + align:start position:0% +the ukian norm right this just means +this is the ukian + + align:start position:0% + + + + align:start position:0% + +norm right that's the one we've seen + + align:start position:0% +norm right that's the one we've seen + + + align:start position:0% +norm right that's the one we've seen +before when we talked about K Square + + align:start position:0% +before when we talked about K Square + + + align:start position:0% +before when we talked about K Square +that's the square Norm is the sum of the + + align:start position:0% +that's the square Norm is the sum of the + + + align:start position:0% +that's the square Norm is the sum of the +square of the coefficients and then I + + align:start position:0% +square of the coefficients and then I + + + align:start position:0% +square of the coefficients and then I +take a square root but here I have an + + align:start position:0% +take a square root but here I have an + + + align:start position:0% +take a square root but here I have an +extra Square so it's really just the sum + + align:start position:0% +extra Square so it's really just the sum + + + align:start position:0% +extra Square so it's really just the sum +of the square of the coefficients which + + align:start position:0% +of the square of the coefficients which + + + align:start position:0% +of the square of the coefficients which +is this and here are the + + align:start position:0% +is this and here are the + + + align:start position:0% +is this and here are the +coefficients okay so now that I write my + + align:start position:0% +coefficients okay so now that I write my + + + align:start position:0% +coefficients okay so now that I write my +uh this this thing like that then + + align:start position:0% +uh this this thing like that then + + + align:start position:0% +uh this this thing like that then +minimizing so my goal here now is going + + align:start position:0% +minimizing so my goal here now is going + + + align:start position:0% +minimizing so my goal here now is going +to solve minimum over T in our P + + align:start position:0% +to solve minimum over T in our P + + + align:start position:0% +to solve minimum over T in our P +of + + align:start position:0% +of + + + align:start position:0% +of +Y minus x * + + align:start position:0% +Y minus x * + + + align:start position:0% +Y minus x * +T 2^ + + align:start position:0% +T 2^ + + + align:start position:0% +T 2^ +2 and just like we did for one dimension + + align:start position:0% +2 and just like we did for one dimension + + + align:start position:0% +2 and just like we did for one dimension +we can actually write optimality + + align:start position:0% +we can actually write optimality + + + align:start position:0% +we can actually write optimality +conditions + + align:start position:0% +conditions + + + align:start position:0% +conditions +for this I mean this is a + + align:start position:0% +for this I mean this is a + + + align:start position:0% +for this I mean this is a +function right so this is a + + align:start position:0% +function right so this is a + + + align:start position:0% +function right so this is a +function from uh uh r p to R and if I + + align:start position:0% +function from uh uh r p to R and if I + + + align:start position:0% +function from uh uh r p to R and if I +want to minimize it all I have to do is + + align:start position:0% +want to minimize it all I have to do is + + + align:start position:0% +want to minimize it all I have to do is +to take its gradient and set it equal to + + align:start position:0% +to take its gradient and set it equal to + + + align:start position:0% +to take its gradient and set it equal to +zero Okay so + + align:start position:0% + + + + align:start position:0% + +minimum + + align:start position:0% +minimum + + + align:start position:0% +minimum +set + + align:start position:0% + + + + align:start position:0% + +gradient to + + align:start position:0% +gradient to + + + align:start position:0% +gradient to +zero so that's where it becomes a little + + align:start position:0% +zero so that's where it becomes a little + + + align:start position:0% +zero so that's where it becomes a little +complicated right now I'm going to have + + align:start position:0% +complicated right now I'm going to have + + + align:start position:0% +complicated right now I'm going to have +to take the gradient of this Norm it + + align:start position:0% +to take the gradient of this Norm it + + + align:start position:0% +to take the gradient of this Norm it +might be a little Annoying to do but + + align:start position:0% +might be a little Annoying to do but + + + align:start position:0% +might be a little Annoying to do but +actually what's nice about those things + + align:start position:0% +actually what's nice about those things + + + align:start position:0% +actually what's nice about those things +I mean I remember that it was a bit + + align:start position:0% +I mean I remember that it was a bit + + + align:start position:0% +I mean I remember that it was a bit +annoying to learn I it's just like + + align:start position:0% +annoying to learn I it's just like + + + align:start position:0% +annoying to learn I it's just like +basically rules of of calculus that you + + align:start position:0% +basically rules of of calculus that you + + + align:start position:0% +basically rules of of calculus that you +don't use that much but essentially you + + align:start position:0% +don't use that much but essentially you + + + align:start position:0% +don't use that much but essentially you +can actually expand this norm and you + + align:start position:0% +can actually expand this norm and you + + + align:start position:0% +can actually expand this norm and you +will see that the rules are basically + + align:start position:0% +will see that the rules are basically + + + align:start position:0% +will see that the rules are basically +the same as in one dimension you just + + align:start position:0% +the same as in one dimension you just + + + align:start position:0% +the same as in one dimension you just +have to be careful about the fact that + + align:start position:0% +have to be careful about the fact that + + + align:start position:0% +have to be careful about the fact that +matrices do not commute okay so let's + + align:start position:0% +matrices do not commute okay so let's + + + align:start position:0% +matrices do not commute okay so let's +expand this + + align:start position:0% +expand this + + + align:start position:0% +expand this +thing y - xt^ 2 well this is equal to + + align:start position:0% +thing y - xt^ 2 well this is equal to + + + align:start position:0% +thing y - xt^ 2 well this is equal to +the norm of + + align:start position:0% +the norm of + + + align:start position:0% +the norm of +y^2 + + align:start position:0% +y^2 + + + align:start position:0% +y^2 +plus uh the + + align:start position:0% +plus uh the + + + align:start position:0% +plus uh the +norm of xt^ 2 + + align:start position:0% +norm of xt^ 2 + + + align:start position:0% +norm of xt^ 2 +plus 2 time y + + align:start position:0% +plus 2 time y + + + align:start position:0% +plus 2 time y +transpose XT + + align:start position:0% +transpose XT + + + align:start position:0% +transpose XT +right that's just expanding the square + + align:start position:0% +right that's just expanding the square + + + align:start position:0% +right that's just expanding the square +in uh more dimensions and this I'm + + align:start position:0% +in uh more dimensions and this I'm + + + align:start position:0% +in uh more dimensions and this I'm +actually going to write as y^ + + align:start position:0% +actually going to write as y^ + + + align:start position:0% +actually going to write as y^ +2 plus so here the norm squar of this + + align:start position:0% +2 plus so here the norm squar of this + + + align:start position:0% +2 plus so here the norm squar of this +guy I always have that the norm of X2 is + + align:start position:0% +guy I always have that the norm of X2 is + + + align:start position:0% +guy I always have that the norm of X2 is +equal to X transpose X + + align:start position:0% +equal to X transpose X + + + align:start position:0% +equal to X transpose X +right so I'm going to write this as X + + align:start position:0% +right so I'm going to write this as X + + + align:start position:0% +right so I'm going to write this as X +transpose X so it's t + + align:start position:0% +transpose X so it's t + + + align:start position:0% +transpose X so it's t +ose Xpose + + align:start position:0% +ose Xpose + + + align:start position:0% +ose Xpose +XT plus 2 * y transpose + + align:start position:0% +XT plus 2 * y transpose + + + align:start position:0% +XT plus 2 * y transpose +XT okay so now if I'm going to take the + + align:start position:0% +XT okay so now if I'm going to take the + + + align:start position:0% +XT okay so now if I'm going to take the +gradient with respect to T I have + + align:start position:0% +gradient with respect to T I have + + + align:start position:0% +gradient with respect to T I have +basically three terms and each of them + + align:start position:0% +basically three terms and each of them + + + align:start position:0% +basically three terms and each of them +has some sort of a different nature this + + align:start position:0% +has some sort of a different nature this + + + align:start position:0% +has some sort of a different nature this +term is linear in + + align:start position:0% +term is linear in + + + align:start position:0% +term is linear in +T and it's going to differentiate the + + align:start position:0% +T and it's going to differentiate the + + + align:start position:0% +T and it's going to differentiate the +same way that I differen a * X right I'm + + align:start position:0% +same way that I differen a * X right I'm + + + align:start position:0% +same way that I differen a * X right I'm +just going to keep the a this guy is + + align:start position:0% +just going to keep the a this guy is + + + align:start position:0% +just going to keep the a this guy is +quadratic T appears twice and this guy + + align:start position:0% +quadratic T appears twice and this guy + + + align:start position:0% +quadratic T appears twice and this guy +I'm going to pick up a two and it's + + align:start position:0% +I'm going to pick up a two and it's + + + align:start position:0% +I'm going to pick up a two and it's +going to differentiate just like when I + + align:start position:0% +going to differentiate just like when I + + + align:start position:0% +going to differentiate just like when I +differentiate a * x^2 it's 2 * ax okay + + align:start position:0% +differentiate a * x^2 it's 2 * ax okay + + + align:start position:0% +differentiate a * x^2 it's 2 * ax okay +and this guy is a constant with respect + + align:start position:0% +and this guy is a constant with respect + + + align:start position:0% +and this guy is a constant with respect +to T so it's going to differentiate to + + align:start position:0% +to T so it's going to differentiate to + + + align:start position:0% +to T so it's going to differentiate to +zero okay so when I compute the + + align:start position:0% + + + + align:start position:0% + +gradient now of course every all these + + align:start position:0% +gradient now of course every all these + + + align:start position:0% +gradient now of course every all these +rules that I give you can check by + + align:start position:0% +rules that I give you can check by + + + align:start position:0% +rules that I give you can check by +looking at the partial derivative with + + align:start position:0% +looking at the partial derivative with + + + align:start position:0% +looking at the partial derivative with +respect to each coordinate but arguably + + align:start position:0% +respect to each coordinate but arguably + + + align:start position:0% +respect to each coordinate but arguably +it's much faster to know the rules of + + align:start position:0% +it's much faster to know the rules of + + + align:start position:0% +it's much faster to know the rules of +differentiability it's like if I gave + + align:start position:0% +differentiability it's like if I gave + + + align:start position:0% +differentiability it's like if I gave +you the function exponential X and I + + align:start position:0% +you the function exponential X and I + + + align:start position:0% +you the function exponential X and I +said what it's a derivative and you + + align:start position:0% +said what it's a derivative and you + + + align:start position:0% +said what it's a derivative and you +started writing well I'm going to write + + align:start position:0% +started writing well I'm going to write + + + align:start position:0% +started writing well I'm going to write +exponential X Plus H minus exponential h + + align:start position:0% +exponential X Plus H minus exponential h + + + align:start position:0% +exponential X Plus H minus exponential h +x ided h and let H go to zero that's a + + align:start position:0% +x ided h and let H go to zero that's a + + + align:start position:0% +x ided h and let H go to zero that's a +bit + + align:start position:0% + + + + align:start position:0% + +painful I'm + + align:start position:0% + + + + align:start position:0% + +sorry the trans ose of two + + align:start position:0% +sorry the trans ose of two + + + align:start position:0% +sorry the trans ose of two +a is B transpose a + + align:start position:0% + + + + align:start position:0% + +transpose if you're not sure about this + + align:start position:0% +transpose if you're not sure about this + + + align:start position:0% +transpose if you're not sure about this +just make a and b have different size + + align:start position:0% +just make a and b have different size + + + align:start position:0% +just make a and b have different size +and then you will see that there's some + + align:start position:0% +and then you will see that there's some + + + align:start position:0% +and then you will see that there's some +not incompatibility I mean there's + + align:start position:0% +not incompatibility I mean there's + + + align:start position:0% +not incompatibility I mean there's +basically only one way to not screw that + + align:start position:0% +basically only one way to not screw that + + + align:start position:0% +basically only one way to not screw that +one up so that's easy to remember all + + align:start position:0% +one up so that's easy to remember all + + + align:start position:0% +one up so that's easy to remember all +right so if I take the gradient then + + align:start position:0% +right so if I take the gradient then + + + align:start position:0% +right so if I take the gradient then +it's going to be equal to what it's + + align:start position:0% +it's going to be equal to what it's + + + align:start position:0% +it's going to be equal to what it's +going to be zero plus we said here this + + align:start position:0% +going to be zero plus we said here this + + + align:start position:0% +going to be zero plus we said here this +is going to differentiate like so + + align:start position:0% + + + + align:start position:0% + +think a * x^2 so I'm going to have 2 ax + + align:start position:0% +think a * x^2 so I'm going to have 2 ax + + + align:start position:0% +think a * x^2 so I'm going to have 2 ax +so here basically this guy is going to + + align:start position:0% +so here basically this guy is going to + + + align:start position:0% +so here basically this guy is going to +go to x transpose XT now I could have + + align:start position:0% +go to x transpose XT now I could have + + + align:start position:0% +go to x transpose XT now I could have +made this one go away but that's the + + align:start position:0% +made this one go away but that's the + + + align:start position:0% +made this one go away but that's the +same thing as saying that my gradient is + + align:start position:0% +same thing as saying that my gradient is + + + align:start position:0% +same thing as saying that my gradient is +I I I can think of my gradient as being + + align:start position:0% +I I I can think of my gradient as being + + + align:start position:0% +I I I can think of my gradient as being +either a horizontal vector or vertical + + align:start position:0% +either a horizontal vector or vertical + + + align:start position:0% +either a horizontal vector or vertical +Vector so if I remove this guy I'm + + align:start position:0% +Vector so if I remove this guy I'm + + + align:start position:0% +Vector so if I remove this guy I'm +thinking of my gradient as being + + align:start position:0% +thinking of my gradient as being + + + align:start position:0% +thinking of my gradient as being +horizontal if I remove that guy I'm + + align:start position:0% +horizontal if I remove that guy I'm + + + align:start position:0% +horizontal if I remove that guy I'm +thinking of my Vector my gradient is + + align:start position:0% +thinking of my Vector my gradient is + + + align:start position:0% +thinking of my Vector my gradient is +being vertical and that's what I want to + + align:start position:0% +being vertical and that's what I want to + + + align:start position:0% +being vertical and that's what I want to +think of typically vertical vectors + + align:start position:0% +think of typically vertical vectors + + + align:start position:0% +think of typically vertical vectors +right column vectors and then this guy + + align:start position:0% +right column vectors and then this guy + + + align:start position:0% +right column vectors and then this guy +well it's like this gu is just + + align:start position:0% +well it's like this gu is just + + + align:start position:0% +well it's like this gu is just +think a * X right so the derivative is + + align:start position:0% +think a * X right so the derivative is + + + align:start position:0% +think a * X right so the derivative is +just a so I'm going to keep only that + + align:start position:0% +just a so I'm going to keep only that + + + align:start position:0% +just a so I'm going to keep only that +part + + align:start position:0% +part + + + align:start position:0% +part +here sorry I forgot a minus somewhere + + align:start position:0% +here sorry I forgot a minus somewhere + + + align:start position:0% +here sorry I forgot a minus somewhere +yeah + + align:start position:0% + + + + align:start position:0% + +here minus 2 y transpose X and what I + + align:start position:0% +here minus 2 y transpose X and what I + + + align:start position:0% +here minus 2 y transpose X and what I +want is this thing to be equal to zero + + align:start position:0% + + + + align:start position:0% + +right so + + align:start position:0% + + + + align:start position:0% + +T the optimal T is + + align:start position:0% +T the optimal T is + + + align:start position:0% +T the optimal T is +called beta hat and + + align:start position:0% + + + + align:start position:0% + +satisfies well I can cancel the twos and + + align:start position:0% +satisfies well I can cancel the twos and + + + align:start position:0% +satisfies well I can cancel the twos and +put the minus on the other side and what + + align:start position:0% +put the minus on the other side and what + + + align:start position:0% +put the minus on the other side and what +I get is that X transpose + + align:start position:0% +I get is that X transpose + + + align:start position:0% +I get is that X transpose +XT is equal to + + align:start position:0% +XT is equal to + + + align:start position:0% +XT is equal to +Y transpose + + align:start position:0% +Y transpose + + + align:start position:0% +Y transpose +X and that's + + align:start position:0% + + + + align:start position:0% + +uh yeah that's not working for me uh + + align:start position:0% +uh yeah that's not working for me uh + + + align:start position:0% +uh yeah that's not working for me uh +yeah that's because when I took the + + align:start position:0% +yeah that's because when I took the + + + align:start position:0% +yeah that's because when I took the +derivative I still need to make sure so + + align:start position:0% +derivative I still need to make sure so + + + align:start position:0% +derivative I still need to make sure so +it's the same question of whether I want + + align:start position:0% +it's the same question of whether I want + + + align:start position:0% +it's the same question of whether I want +things to be columns or rows right so + + align:start position:0% +things to be columns or rows right so + + + align:start position:0% +things to be columns or rows right so +this is not a column right if I remove + + align:start position:0% +this is not a column right if I remove + + + align:start position:0% +this is not a column right if I remove +that guy why transpose T is a row so I'm + + align:start position:0% +that guy why transpose T is a row so I'm + + + align:start position:0% +that guy why transpose T is a row so I'm +just going to take the transpose of this + + align:start position:0% +just going to take the transpose of this + + + align:start position:0% +just going to take the transpose of this +guy to make things work and this is just + + align:start position:0% +guy to make things work and this is just + + + align:start position:0% +guy to make things work and this is just +going to be X transpose + + align:start position:0% + + + + align:start position:0% + +Y and this guy is X transpose y so that + + align:start position:0% +Y and this guy is X transpose y so that + + + align:start position:0% +Y and this guy is X transpose y so that +I have + + align:start position:0% + + + + align:start position:0% + +columns okay so this is just a linear + + align:start position:0% +columns okay so this is just a linear + + + align:start position:0% +columns okay so this is just a linear +equation in T and I have to solve it so + + align:start position:0% +equation in T and I have to solve it so + + + align:start position:0% +equation in T and I have to solve it so +it's of the form so Matrix time T is + + align:start position:0% +it's of the form so Matrix time T is + + + align:start position:0% +it's of the form so Matrix time T is +equal to another vector and so that's a + + align:start position:0% +equal to another vector and so that's a + + + align:start position:0% +equal to another vector and so that's a +basic linear system and the way to solve + + align:start position:0% +basic linear system and the way to solve + + + align:start position:0% +basic linear system and the way to solve +it at least formally is to just take the + + align:start position:0% +it at least formally is to just take the + + + align:start position:0% +it at least formally is to just take the +inverse of the Matrix on the left okay + + align:start position:0% +inverse of the Matrix on the left okay + + + align:start position:0% +inverse of the Matrix on the left okay +so + + align:start position:0% +so + + + align:start position:0% +so +if x transpose + + align:start position:0% +if x transpose + + + align:start position:0% +if x transpose +X is + + align:start position:0% + + + + align:start position:0% + +invertible then sorry that's beta hat is + + align:start position:0% +invertible then sorry that's beta hat is + + + align:start position:0% +invertible then sorry that's beta hat is +the T I want I get that beta hat is + + align:start position:0% +the T I want I get that beta hat is + + + align:start position:0% +the T I want I get that beta hat is +equal to X transpose X inverse X + + align:start position:0% +equal to X transpose X inverse X + + + align:start position:0% +equal to X transpose X inverse X +transpose + + align:start position:0% + + + + align:start position:0% + +Y and that's the Le squares as + + align:start position:0% + + + + align:start position:0% + +so here I I Ed this condition + + align:start position:0% +so here I I Ed this condition + + + align:start position:0% +so here I I Ed this condition +right I want it to be invertible so I + + align:start position:0% +right I want it to be invertible so I + + + align:start position:0% +right I want it to be invertible so I +can actually write its + + align:start position:0% +can actually write its + + + align:start position:0% +can actually write its +inverse here I wrote Rank of X is equal + + align:start position:0% +inverse here I wrote Rank of X is equal + + + align:start position:0% +inverse here I wrote Rank of X is equal +to + + align:start position:0% +to + + + align:start position:0% +to +P what is the difference + + align:start position:0% + + + + align:start position:0% + +well there's basically no difference + + align:start position:0% +well there's basically no difference + + + align:start position:0% +well there's basically no difference +right basically here I have to + + align:start position:0% +right basically here I have to + + + align:start position:0% +right basically here I have to +assume what is the size of the Matrix X + + align:start position:0% +assume what is the size of the Matrix X + + + align:start position:0% +assume what is the size of the Matrix X +transpose + + align:start position:0% + + + + align:start position:0% + +X yeah so what is the + + align:start position:0% +X yeah so what is the + + + align:start position:0% +X yeah so what is the +size P by P right so this Matrix is + + align:start position:0% +size P by P right so this Matrix is + + + align:start position:0% +size P by P right so this Matrix is +invertible if it's a rank P if you know + + align:start position:0% +invertible if it's a rank P if you know + + + align:start position:0% +invertible if it's a rank P if you know +what rank means if you don't that just + + align:start position:0% +what rank means if you don't that just + + + align:start position:0% +what rank means if you don't that just +rank p means that it's invertible all + + align:start position:0% +rank p means that it's invertible all + + + align:start position:0% +rank p means that it's invertible all +right so it's full Rank and it's + + align:start position:0% +right so it's full Rank and it's + + + align:start position:0% +right so it's full Rank and it's +invertible and the rank of XX trans of X + + align:start position:0% +invertible and the rank of XX trans of X + + + align:start position:0% +invertible and the rank of XX trans of X +transposes is actually just the rank of + + align:start position:0% +transposes is actually just the rank of + + + align:start position:0% +transposes is actually just the rank of +X because this is the same Matrix that + + align:start position:0% +X because this is the same Matrix that + + + align:start position:0% +X because this is the same Matrix that +you apply twice and that's all it's + + align:start position:0% +you apply twice and that's all it's + + + align:start position:0% +you apply twice and that's all it's +saying so if you're not comfortable with + + align:start position:0% +saying so if you're not comfortable with + + + align:start position:0% +saying so if you're not comfortable with +the notion of rank that you see here + + align:start position:0% +the notion of rank that you see here + + + align:start position:0% +the notion of rank that you see here +just think of this condition just being + + align:start position:0% +just think of this condition just being + + + align:start position:0% +just think of this condition just being +the condition that X transpose X is + + align:start position:0% +the condition that X transpose X is + + + align:start position:0% +the condition that X transpose X is +invertible and that's all it says what + + align:start position:0% +invertible and that's all it says what + + + align:start position:0% +invertible and that's all it says what +it means for it to be invertible this + + align:start position:0% +it means for it to be invertible this + + + align:start position:0% +it means for it to be invertible this +was true right we made no assumption up + + align:start position:0% +was true right we made no assumption up + + + align:start position:0% +was true right we made no assumption up +to this point it if X is not + + align:start position:0% +to this point it if X is not + + + align:start position:0% +to this point it if X is not +invertible it means that there might be + + align:start position:0% +invertible it means that there might be + + + align:start position:0% +invertible it means that there might be +multiple solutions to this equation + + align:start position:0% +multiple solutions to this equation + + + align:start position:0% +multiple solutions to this equation +right in particular for a matrix to not + + align:start position:0% +right in particular for a matrix to not + + + align:start position:0% +right in particular for a matrix to not +be + + align:start position:0% +be + + + align:start position:0% +be +invertible it means that there's some + + align:start position:0% +invertible it means that there's some + + + align:start position:0% +invertible it means that there's some +vector v so if x transpose + + align:start position:0% +vector v so if x transpose + + + align:start position:0% +vector v so if x transpose +X is not + + align:start position:0% + + + + align:start position:0% + +invertible then this is + + align:start position:0% +invertible then this is + + + align:start position:0% +invertible then this is +equivalent to their exist a vector v + + align:start position:0% +equivalent to their exist a vector v + + + align:start position:0% +equivalent to their exist a vector v +which is not zero and such that Xpose x + + align:start position:0% +which is not zero and such that Xpose x + + + align:start position:0% +which is not zero and such that Xpose x +v is equal to zero right that's what it + + align:start position:0% +v is equal to zero right that's what it + + + align:start position:0% +v is equal to zero right that's what it +mean to not be invertible so in + + align:start position:0% +mean to not be invertible so in + + + align:start position:0% +mean to not be invertible so in +particular if Beta had to a + + align:start position:0% + + + + align:start position:0% + +solution so this equation is sometimes + + align:start position:0% +solution so this equation is sometimes + + + align:start position:0% +solution so this equation is sometimes +called score + + align:start position:0% +called score + + + align:start position:0% +called score +equations because the gradient is called + + align:start position:0% +equations because the gradient is called + + + align:start position:0% +equations because the gradient is called +the score and so you're just checking if + + align:start position:0% +the score and so you're just checking if + + + align:start position:0% +the score and so you're just checking if +the gradient is equal to zero so if Beta + + align:start position:0% +the gradient is equal to zero so if Beta + + + align:start position:0% +the gradient is equal to zero so if Beta +had satisfy star then so + + align:start position:0% + + + + align:start position:0% + +does beta hat plus Lambda V for all + + align:start position:0% +does beta hat plus Lambda V for all + + + align:start position:0% +does beta hat plus Lambda V for all +Lambda in the real + + align:start position:0% + + + + align:start position:0% + +line right and the reason is because + + align:start position:0% +line right and the reason is because + + + align:start position:0% +line right and the reason is because +well if I start looking at what is X + + align:start position:0% +well if I start looking at what is X + + + align:start position:0% +well if I start looking at what is X +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +x times beta hat plus Lambda + + align:start position:0% +x times beta hat plus Lambda + + + align:start position:0% +x times beta hat plus Lambda +V well by linearity this is just X + + align:start position:0% +V well by linearity this is just X + + + align:start position:0% +V well by linearity this is just X +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +X beta hat plus Lambda Xpose + + align:start position:0% +X beta hat plus Lambda Xpose + + + align:start position:0% +X beta hat plus Lambda Xpose +X time + + align:start position:0% +X time + + + align:start position:0% +X time +V but this guy is + + align:start position:0% + + + + align:start position:0% + +what it's zero + + align:start position:0% + + + + align:start position:0% + +right just because that's what we + + align:start position:0% +right just because that's what we + + + align:start position:0% +right just because that's what we +assumed we assume that X transpose XV + + align:start position:0% +assumed we assume that X transpose XV + + + align:start position:0% +assumed we assume that X transpose XV +was equal to zero so we're left only + + align:start position:0% +was equal to zero so we're left only + + + align:start position:0% +was equal to zero so we're left only +with this part which by star is just X + + align:start position:0% +with this part which by star is just X + + + align:start position:0% +with this part which by star is just X +transpose + + align:start position:0% + + + + align:start position:0% + +y so that means that X transpose X beta + + align:start position:0% +y so that means that X transpose X beta + + + align:start position:0% +y so that means that X transpose X beta +hat plus Lambda V is actually equal to X + + align:start position:0% +hat plus Lambda V is actually equal to X + + + align:start position:0% +hat plus Lambda V is actually equal to X +transpose Y which means that there's + + align:start position:0% +transpose Y which means that there's + + + align:start position:0% +transpose Y which means that there's +another solution which is not not just + + align:start position:0% +another solution which is not not just + + + align:start position:0% +another solution which is not not just +beta hat but any move of beta hat along + + align:start position:0% +beta hat but any move of beta hat along + + + align:start position:0% +beta hat but any move of beta hat along +this direction V in any by any + + align:start position:0% +this direction V in any by any + + + align:start position:0% +this direction V in any by any +size so that's going to be an issue + + align:start position:0% +size so that's going to be an issue + + + align:start position:0% +size so that's going to be an issue +right because you're finding you're + + align:start position:0% +right because you're finding you're + + + align:start position:0% +right because you're finding you're +looking for for one estimator and + + align:start position:0% +looking for for one estimator and + + + align:start position:0% +looking for for one estimator and +there's not just one in this case + + align:start position:0% +there's not just one in this case + + + align:start position:0% +there's not just one in this case +there's many and so this is not going to + + align:start position:0% +there's many and so this is not going to + + + align:start position:0% +there's many and so this is not going to +be well defined and you're going to have + + align:start position:0% +be well defined and you're going to have + + + align:start position:0% +be well defined and you're going to have +some issues so if you want to talk about + + align:start position:0% +some issues so if you want to talk about + + + align:start position:0% +some issues so if you want to talk about +the Le squares estimator you have to + + align:start position:0% +the Le squares estimator you have to + + + align:start position:0% +the Le squares estimator you have to +make this + + align:start position:0% + + + + align:start position:0% + +assumption what does it imply in terms + + align:start position:0% +assumption what does it imply in terms + + + align:start position:0% +assumption what does it imply in terms +of can I think of P being 2N for example + + align:start position:0% +of can I think of P being 2N for example + + + align:start position:0% +of can I think of P being 2N for example +in this case what happens if p is equal + + align:start position:0% +in this case what happens if p is equal + + + align:start position:0% +in this case what happens if p is equal +to 2N + + align:start position:0% + + + + align:start position:0% + +is only P so the rank of your Matrix is + + align:start position:0% +is only P so the rank of your Matrix is + + + align:start position:0% +is only P so the rank of your Matrix is +only p over two right so that means that + + align:start position:0% +only p over two right so that means that + + + align:start position:0% +only p over two right so that means that +this is actually not going to happen + + align:start position:0% +this is actually not going to happen + + + align:start position:0% +this is actually not going to happen +right I mean it's not only P over2 it's + + align:start position:0% +right I mean it's not only P over2 it's + + + align:start position:0% +right I mean it's not only P over2 it's +at most P over2 right it's at most the + + align:start position:0% +at most P over2 right it's at most the + + + align:start position:0% +at most P over2 right it's at most the +smallest of the two dimensions of your + + align:start position:0% +smallest of the two dimensions of your + + + align:start position:0% +smallest of the two dimensions of your +Matrix so if your Matrix is n * 2 N it's + + align:start position:0% +Matrix so if your Matrix is n * 2 N it's + + + align:start position:0% +Matrix so if your Matrix is n * 2 N it's +at most n which means that it's not + + align:start position:0% +at most n which means that it's not + + + align:start position:0% +at most n which means that it's not +going to be full rank so it's not going + + align:start position:0% +going to be full rank so it's not going + + + align:start position:0% +going to be full rank so it's not going +to be invertible so every time the + + align:start position:0% +to be invertible so every time the + + + align:start position:0% +to be invertible so every time the +dimension p is larger than the sample + + align:start position:0% +dimension p is larger than the sample + + + align:start position:0% +dimension p is larger than the sample +size your Matrix is not invertible and + + align:start position:0% +size your Matrix is not invertible and + + + align:start position:0% +size your Matrix is not invertible and +you cannot talk about the least course + + align:start position:0% +you cannot talk about the least course + + + align:start position:0% +you cannot talk about the least course +estimator so that's something to keep in + + align:start position:0% +estimator so that's something to keep in + + + align:start position:0% +estimator so that's something to keep in +mind + + align:start position:0% +mind + + + align:start position:0% +mind +and it's actually a very simple thing + + align:start position:0% +and it's actually a very simple thing + + + align:start position:0% +and it's actually a very simple thing +it's essentially saying well if p is + + align:start position:0% +it's essentially saying well if p is + + + align:start position:0% +it's essentially saying well if p is +larer than n it means that you have more + + align:start position:0% +larer than n it means that you have more + + + align:start position:0% +larer than n it means that you have more +parameters to estimate than you have + + align:start position:0% +parameters to estimate than you have + + + align:start position:0% +parameters to estimate than you have +equations to estimate it right so you + + align:start position:0% +equations to estimate it right so you + + + align:start position:0% +equations to estimate it right so you +have this linear system there's one + + align:start position:0% +have this linear system there's one + + + align:start position:0% +have this linear system there's one +equation uh per observation right each + + align:start position:0% +equation uh per observation right each + + + align:start position:0% +equation uh per observation right each +row which was each observation was + + align:start position:0% +row which was each observation was + + + align:start position:0% +row which was each observation was +giving me one equation but then the + + align:start position:0% +giving me one equation but then the + + + align:start position:0% +giving me one equation but then the +number of unknowns in this linear system + + align:start position:0% +number of unknowns in this linear system + + + align:start position:0% +number of unknowns in this linear system +is p and so I cannot solve linear + + align:start position:0% +is p and so I cannot solve linear + + + align:start position:0% +is p and so I cannot solve linear +systems that have more unknowns than + + align:start position:0% +systems that have more unknowns than + + + align:start position:0% +systems that have more unknowns than +they have equations and so that's + + align:start position:0% +they have equations and so that's + + + align:start position:0% +they have equations and so that's +basically what's happening now in + + align:start position:0% +basically what's happening now in + + + align:start position:0% +basically what's happening now in +practice if you think about what data + + align:start position:0% +practice if you think about what data + + + align:start position:0% +practice if you think about what data +sets look like these days for example + + align:start position:0% +sets look like these days for example + + + align:start position:0% +sets look like these days for example +people are trying to express some + + align:start position:0% +people are trying to express some + + + align:start position:0% +people are trying to express some +phenotypes some phenotype is something + + align:start position:0% +phenotypes some phenotype is something + + + align:start position:0% +phenotypes some phenotype is something +you can measure on people maybe I don't + + align:start position:0% +you can measure on people maybe I don't + + + align:start position:0% +you can measure on people maybe I don't +know the color of your eyes or your + + align:start position:0% +know the color of your eyes or your + + + align:start position:0% +know the color of your eyes or your +height or whether you have diabetes or + + align:start position:0% +height or whether you have diabetes or + + + align:start position:0% +height or whether you have diabetes or +not things like this right so things + + align:start position:0% +not things like this right so things + + + align:start position:0% +not things like this right so things +that you know are sort of + + align:start position:0% +that you know are sort of + + + align:start position:0% +that you know are sort of +macroscopic and then they want to use + + align:start position:0% +macroscopic and then they want to use + + + align:start position:0% +macroscopic and then they want to use +the genotype to do that right they want + + align:start position:0% +the genotype to do that right they want + + + align:start position:0% +the genotype to do that right they want +to measure your they want to sequence + + align:start position:0% +to measure your they want to sequence + + + align:start position:0% +to measure your they want to sequence +your genome and try to use this to + + align:start position:0% +your genome and try to use this to + + + align:start position:0% +your genome and try to use this to +predict whether you're going to be + + align:start position:0% +predict whether you're going to be + + + align:start position:0% +predict whether you're going to be +responsive to a drug or whether your RS + + align:start position:0% +responsive to a drug or whether your RS + + + align:start position:0% +responsive to a drug or whether your RS +are going to be blue or something like + + align:start position:0% +are going to be blue or something like + + + align:start position:0% +are going to be blue or something like +this now the data sets that you can have + + align:start position:0% +this now the data sets that you can have + + + align:start position:0% +this now the data sets that you can have +people maybe for a given study about I + + align:start position:0% +people maybe for a given study about I + + + align:start position:0% +people maybe for a given study about I +don't know some sort of disease maybe + + align:start position:0% +don't know some sort of disease maybe + + + align:start position:0% +don't know some sort of disease maybe +you will you know sequence the Genome of + + align:start position:0% +you will you know sequence the Genome of + + + align:start position:0% +you will you know sequence the Genome of +maybe 100 people right n is equal to + + align:start position:0% +maybe 100 people right n is equal to + + + align:start position:0% +maybe 100 people right n is equal to +100 p is basically the number of genes + + align:start position:0% +100 p is basically the number of genes + + + align:start position:0% +100 p is basically the number of genes +they're sequencing this is of theod of + + align:start position:0% +they're sequencing this is of theod of + + + align:start position:0% +they're sequencing this is of theod of +100,000 so you can imagine that this is + + align:start position:0% +100,000 so you can imagine that this is + + + align:start position:0% +100,000 so you can imagine that this is +a case where n is much much smaller than + + align:start position:0% +a case where n is much much smaller than + + + align:start position:0% +a case where n is much much smaller than +p and you cannot talk about the least s + + align:start position:0% +p and you cannot talk about the least s + + + align:start position:0% +p and you cannot talk about the least s +estimator there's plenty of them there's + + align:start position:0% +estimator there's plenty of them there's + + + align:start position:0% +estimator there's plenty of them there's +not just one line like that Lambda time + + align:start position:0% +not just one line like that Lambda time + + + align:start position:0% +not just one line like that Lambda time +V that you can move away there's + + align:start position:0% +V that you can move away there's + + + align:start position:0% +V that you can move away there's +basically an entire space in which you + + align:start position:0% +basically an entire space in which you + + + align:start position:0% +basically an entire space in which you +can move and so it's not well defined so + + align:start position:0% +can move and so it's not well defined so + + + align:start position:0% +can move and so it's not well defined so +at the end of this class I will give you + + align:start position:0% +at the end of this class I will give you + + + align:start position:0% +at the end of this class I will give you +a short introduction on how you do this + + align:start position:0% +a short introduction on how you do this + + + align:start position:0% +a short introduction on how you do this +like this actually represent more and + + align:start position:0% +like this actually represent more and + + + align:start position:0% +like this actually represent more and +more becomes a more and more + + align:start position:0% +more becomes a more and more + + + align:start position:0% +more becomes a more and more +preponderant part of the data sets you + + align:start position:0% +preponderant part of the data sets you + + + align:start position:0% +preponderant part of the data sets you +have to deal with because people just + + align:start position:0% +have to deal with because people just + + + align:start position:0% +have to deal with because people just +collect data right when I do the + + align:start position:0% +collect data right when I do the + + + align:start position:0% +collect data right when I do the +sequencing you know the machine allows + + align:start position:0% +sequencing you know the machine allows + + + align:start position:0% +sequencing you know the machine allows +me to sequence 100,000 genes I'm not + + align:start position:0% +me to sequence 100,000 genes I'm not + + + align:start position:0% +me to sequence 100,000 genes I'm not +going to stop at 100 because you know + + align:start position:0% +going to stop at 100 because you know + + + align:start position:0% +going to stop at 100 because you know +doctors are never going to have cohorts + + align:start position:0% +doctors are never going to have cohorts + + + align:start position:0% +doctors are never going to have cohorts +of more than 100 patients so you just + + align:start position:0% +of more than 100 patients so you just + + + align:start position:0% +of more than 100 patients so you just +collect everything you can collect and + + align:start position:0% +collect everything you can collect and + + + align:start position:0% +collect everything you can collect and +this is true for everything you know M + + align:start position:0% +this is true for everything you know M + + + align:start position:0% +this is true for everything you know M +cars have sensors all over the place + + align:start position:0% +cars have sensors all over the place + + + align:start position:0% +cars have sensors all over the place +much more than they actually gather data + + align:start position:0% +much more than they actually gather data + + + align:start position:0% +much more than they actually gather data +there's data there's you know we're + + align:start position:0% +there's data there's you know we're + + + align:start position:0% +there's data there's you know we're +creating we're recording everything we + + align:start position:0% +creating we're recording everything we + + + align:start position:0% +creating we're recording everything we +can and so we need some new techniques + + align:start position:0% +can and so we need some new techniques + + + align:start position:0% +can and so we need some new techniques +for that and that's what high + + align:start position:0% +for that and that's what high + + + align:start position:0% +for that and that's what high +dimensional statistics is trying to + + align:start position:0% +dimensional statistics is trying to + + + align:start position:0% +dimensional statistics is trying to +answer so this is Way Beyond the scope + + align:start position:0% +answer so this is Way Beyond the scope + + + align:start position:0% +answer so this is Way Beyond the scope +of this class but towards the end I will + + align:start position:0% +of this class but towards the end I will + + + align:start position:0% +of this class but towards the end I will +give you some hints about what can be + + align:start position:0% +give you some hints about what can be + + + align:start position:0% +give you some hints about what can be +done in this framework because well you + + align:start position:0% +done in this framework because well you + + + align:start position:0% +done in this framework because well you +know we just this is the new reality we + + align:start position:0% +know we just this is the new reality we + + + align:start position:0% +know we just this is the new reality we +have to deal + + align:start position:0% +have to deal + + + align:start position:0% +have to deal +with okay so here we're in a case where + + align:start position:0% +with okay so here we're in a case where + + + align:start position:0% +with okay so here we're in a case where +p is less than n typically much smaller + + align:start position:0% +p is less than n typically much smaller + + + align:start position:0% +p is less than n typically much smaller +than n so the kind of orders of + + align:start position:0% +than n so the kind of orders of + + + align:start position:0% +than n so the kind of orders of +magnitude you want to have is maybe p is + + align:start position:0% +magnitude you want to have is maybe p is + + + align:start position:0% +magnitude you want to have is maybe p is +of order 10 and uh N is a order 100 + + align:start position:0% +of order 10 and uh N is a order 100 + + + align:start position:0% +of order 10 and uh N is a order 100 +something like this so you can scale + + align:start position:0% +something like this so you can scale + + + align:start position:0% +something like this so you can scale +that but maybe 10 times larger all right + + align:start position:0% +that but maybe 10 times larger all right + + + align:start position:0% +that but maybe 10 times larger all right +so maybe you cannot solve this + + align:start position:0% +so maybe you cannot solve this + + + align:start position:0% +so maybe you cannot solve this +guy B for B hat but actually you can + + align:start position:0% +guy B for B hat but actually you can + + + align:start position:0% +guy B for B hat but actually you can +talk about x * B hat even if p is lower + + align:start position:0% +talk about x * B hat even if p is lower + + + align:start position:0% +talk about x * B hat even if p is lower +than n and the reason is + + align:start position:0% +than n and the reason is + + + align:start position:0% +than n and the reason is +that x * B hat is actually something + + align:start position:0% +that x * B hat is actually something + + + align:start position:0% +that x * B hat is actually something +that's very well defined so what is x + + align:start position:0% +that's very well defined so what is x + + + align:start position:0% +that's very well defined so what is x +times B hat right remember I started to + + align:start position:0% +times B hat right remember I started to + + + align:start position:0% +times B hat right remember I started to +I started with the + + align:start position:0% +I started with the + + + align:start position:0% +I started with the +model so if I look at this definition + + align:start position:0% +model so if I look at this definition + + + align:start position:0% +model so if I look at this definition +essentially what I had as a original + + align:start position:0% +essentially what I had as a original + + + align:start position:0% +essentially what I had as a original +thing was that the vector y was equal to + + align:start position:0% +thing was that the vector y was equal to + + + align:start position:0% +thing was that the vector y was equal to +x * beta plus the vector Epsilon that + + align:start position:0% +x * beta plus the vector Epsilon that + + + align:start position:0% +x * beta plus the vector Epsilon that +was my model + + align:start position:0% +was my model + + + align:start position:0% +was my model +right so beta is actually giving me + + align:start position:0% +right so beta is actually giving me + + + align:start position:0% +right so beta is actually giving me +something beta is actually some some + + align:start position:0% +something beta is actually some some + + + align:start position:0% +something beta is actually some some +parameters some coefficients that are + + align:start position:0% +parameters some coefficients that are + + + align:start position:0% +parameters some coefficients that are +interesting but a good estimator for so + + align:start position:0% +interesting but a good estimator for so + + + align:start position:0% +interesting but a good estimator for so +here it means that the the observations + + align:start position:0% +here it means that the the observations + + + align:start position:0% +here it means that the the observations +that I have are of the form x * beta + + align:start position:0% +that I have are of the form x * beta + + + align:start position:0% +that I have are of the form x * beta +plus some noise so if I want to just the + + align:start position:0% +plus some noise so if I want to just the + + + align:start position:0% +plus some noise so if I want to just the +noise remove the noise a good candidate + + align:start position:0% +noise remove the noise a good candidate + + + align:start position:0% +noise remove the noise a good candidate +to the noise is x * beta + + align:start position:0% +to the noise is x * beta + + + align:start position:0% +to the noise is x * beta +hat right x * beta hat is something that + + align:start position:0% +hat right x * beta hat is something that + + + align:start position:0% +hat right x * beta hat is something that +should actually be useful to me which + + align:start position:0% +should actually be useful to me which + + + align:start position:0% +should actually be useful to me which +should be close + + align:start position:0% + + + + align:start position:0% + +to to x * + + align:start position:0% +to to x * + + + align:start position:0% +to to x * +beta so in the one-dimensional case what + + align:start position:0% +beta so in the one-dimensional case what + + + align:start position:0% +beta so in the one-dimensional case what +it means is that if I have let's say + + align:start position:0% +it means is that if I have let's say + + + align:start position:0% +it means is that if I have let's say +this is the true line and these are my + + align:start position:0% +this is the true line and these are my + + + align:start position:0% +this is the true line and these are my +x's so I have those are the true points + + align:start position:0% +x's so I have those are the true points + + + align:start position:0% +x's so I have those are the true points +on the real line and then I have my + + align:start position:0% +on the real line and then I have my + + + align:start position:0% +on the real line and then I have my +little epsilons that just give me my + + align:start position:0% +little epsilons that just give me my + + + align:start position:0% +little epsilons that just give me my +observations that you know move around + + align:start position:0% +observations that you know move around + + + align:start position:0% +observations that you know move around +this this line right so this is this is + + align:start position:0% +this this line right so this is this is + + + align:start position:0% +this this line right so this is this is +one of the Epsilon say epsilon + + align:start position:0% +one of the Epsilon say epsilon + + + align:start position:0% +one of the Epsilon say epsilon +I then I can actually either talk to to + + align:start position:0% +I then I can actually either talk to to + + + align:start position:0% +I then I can actually either talk to to +say that I recovered the line I can + + align:start position:0% +say that I recovered the line I can + + + align:start position:0% +say that I recovered the line I can +actually talk about recovering the right + + align:start position:0% +actually talk about recovering the right + + + align:start position:0% +actually talk about recovering the right +intercept or recovering the right slope + + align:start position:0% +intercept or recovering the right slope + + + align:start position:0% +intercept or recovering the right slope +for this line right those are the two + + align:start position:0% +for this line right those are the two + + + align:start position:0% +for this line right those are the two +parameters that I need to recover but I + + align:start position:0% +parameters that I need to recover but I + + + align:start position:0% +parameters that I need to recover but I +can also say that I've actually found a + + align:start position:0% +can also say that I've actually found a + + + align:start position:0% +can also say that I've actually found a +set of points that's closer to being on + + align:start position:0% +set of points that's closer to being on + + + align:start position:0% +set of points that's closer to being on +a line than the than that that are + + align:start position:0% +a line than the than that that are + + + align:start position:0% +a line than the than that that are +closer to this set of points right here + + align:start position:0% +closer to this set of points right here + + + align:start position:0% +closer to this set of points right here +than the original cross process that I + + align:start position:0% +than the original cross process that I + + + align:start position:0% +than the original cross process that I +observed right so if we go back to the + + align:start position:0% +observed right so if we go back to the + + + align:start position:0% +observed right so if we go back to the +picture here for + + align:start position:0% +picture here for + + + align:start position:0% +picture here for +example what I could do is say well for + + align:start position:0% +example what I could do is say well for + + + align:start position:0% +example what I could do is say well for +this point here right there was an X + + align:start position:0% +this point here right there was an X + + + align:start position:0% +this point here right there was an X +here rather than looking at this dot + + align:start position:0% +here rather than looking at this dot + + + align:start position:0% +here rather than looking at this dot +which was my observation I can say well + + align:start position:0% +which was my observation I can say well + + + align:start position:0% +which was my observation I can say well +now that I've estimated the red line I + + align:start position:0% +now that I've estimated the red line I + + + align:start position:0% +now that I've estimated the red line I +can actually just say well this point + + align:start position:0% +can actually just say well this point + + + align:start position:0% +can actually just say well this point +should really be here and actually I can + + align:start position:0% +should really be here and actually I can + + + align:start position:0% +should really be here and actually I can +move all this dots so that they're + + align:start position:0% +move all this dots so that they're + + + align:start position:0% +move all this dots so that they're +actually on the red line and this should + + align:start position:0% +actually on the red line and this should + + + align:start position:0% +actually on the red line and this should +be a better value something that has + + align:start position:0% +be a better value something that has + + + align:start position:0% +be a better value something that has +less noise than the original y value + + align:start position:0% +less noise than the original y value + + + align:start position:0% +less noise than the original y value +that I should see it should be close to + + align:start position:0% +that I should see it should be close to + + + align:start position:0% +that I should see it should be close to +the True Value that I should be seeing + + align:start position:0% +the True Value that I should be seeing + + + align:start position:0% +the True Value that I should be seeing +without the extra + + align:start position:0% +without the extra + + + align:start position:0% +without the extra +noise so that's definitely something + + align:start position:0% +noise so that's definitely something + + + align:start position:0% +noise so that's definitely something +that could be of + + align:start position:0% +that could be of + + + align:start position:0% +that could be of +interest right for example in imaging + + align:start position:0% +interest right for example in imaging + + + align:start position:0% +interest right for example in imaging +you're not trying to understand so when + + align:start position:0% +you're not trying to understand so when + + + align:start position:0% +you're not trying to understand so when +you do imaging Y is basically an image + + align:start position:0% +you do imaging Y is basically an image + + + align:start position:0% +you do imaging Y is basically an image +right so think of a pixel image and you + + align:start position:0% +right so think of a pixel image and you + + + align:start position:0% +right so think of a pixel image and you +just stack it into one long vector and + + align:start position:0% +just stack it into one long vector and + + + align:start position:0% +just stack it into one long vector and +what you see is something that should + + align:start position:0% +what you see is something that should + + + align:start position:0% +what you see is something that should +look like some linear combination of + + align:start position:0% +look like some linear combination of + + + align:start position:0% +look like some linear combination of +some feature vectors right some maybe so + + align:start position:0% +some feature vectors right some maybe so + + + align:start position:0% +some feature vectors right some maybe so +there's people have a bunch of uh uh + + align:start position:0% +there's people have a bunch of uh uh + + + align:start position:0% +there's people have a bunch of uh uh +created a bunch of features they're + + align:start position:0% +created a bunch of features they're + + + align:start position:0% +created a bunch of features they're +called for example Gabor frames or + + align:start position:0% +called for example Gabor frames or + + + align:start position:0% +called for example Gabor frames or +wavelets uh transform so just like + + align:start position:0% +wavelets uh transform so just like + + + align:start position:0% +wavelets uh transform so just like +well-known libraries of of uh uh + + align:start position:0% +well-known libraries of of uh uh + + + align:start position:0% +well-known libraries of of uh uh +variables X such that when you take + + align:start position:0% +variables X such that when you take + + + align:start position:0% +variables X such that when you take +linear combinations of those guys they + + align:start position:0% +linear combinations of those guys they + + + align:start position:0% +linear combinations of those guys they +should look like a bunch of images and + + align:start position:0% +should look like a bunch of images and + + + align:start position:0% +should look like a bunch of images and +uh and uh what you want for your image + + align:start position:0% +uh and uh what you want for your image + + + align:start position:0% +uh and uh what you want for your image +you don't care what the coefficients of + + align:start position:0% +you don't care what the coefficients of + + + align:start position:0% +you don't care what the coefficients of +the image are in this basis that you + + align:start position:0% +the image are in this basis that you + + + align:start position:0% +the image are in this basis that you +came up with what you care about is the + + align:start position:0% +came up with what you care about is the + + + align:start position:0% +came up with what you care about is the +noising the image and so you really want + + align:start position:0% +noising the image and so you really want + + + align:start position:0% +noising the image and so you really want +to get X + + align:start position:0% +to get X + + + align:start position:0% +to get X +beta all right so if you want to + + align:start position:0% +beta all right so if you want to + + + align:start position:0% +beta all right so if you want to +estimate X beta well you can use x beta + + align:start position:0% +estimate X beta well you can use x beta + + + align:start position:0% +estimate X beta well you can use x beta +hat and the way what is X beta hat well + + align:start position:0% +hat and the way what is X beta hat well + + + align:start position:0% +hat and the way what is X beta hat well +since X beta since beta hat is X + + align:start position:0% +since X beta since beta hat is X + + + align:start position:0% +since X beta since beta hat is X +transpose X inverse X transpose y this + + align:start position:0% +transpose X inverse X transpose y this + + + align:start position:0% +transpose X inverse X transpose y this +is X + + align:start position:0% +is X + + + align:start position:0% +is X +[Applause] + + align:start position:0% + + + + align:start position:0% + +transpose right that's my estimator for + + align:start position:0% +transpose right that's my estimator for + + + align:start position:0% +transpose right that's my estimator for +X + + align:start position:0% + + + + align:start position:0% + +beta now this thing + + align:start position:0% + + + + align:start position:0% + +actually I can Define even if I'm not + + align:start position:0% +actually I can Define even if I'm not + + + align:start position:0% +actually I can Define even if I'm not +low rank so why is this thing + + align:start position:0% +low rank so why is this thing + + + align:start position:0% +low rank so why is this thing +interesting + + align:start position:0% +interesting + + + align:start position:0% +interesting +well you know there's a formula for this + + align:start position:0% +well you know there's a formula for this + + + align:start position:0% +well you know there's a formula for this +estimator but actually I can visualize + + align:start position:0% +estimator but actually I can visualize + + + align:start position:0% +estimator but actually I can visualize +what this thing + + align:start position:0% + + + + align:start position:0% + +is so let's assume for the sake of + + align:start position:0% +is so let's assume for the sake of + + + align:start position:0% +is so let's assume for the sake of +illustration that + + align:start position:0% +illustration that + + + align:start position:0% +illustration that +n is equal to + + align:start position:0% +n is equal to + + + align:start position:0% +n is equal to +three okay okay so that means that y + + align:start position:0% +three okay okay so that means that y + + + align:start position:0% +three okay okay so that means that y +lives in a three-dimensional space and + + align:start position:0% +lives in a three-dimensional space and + + + align:start position:0% +lives in a three-dimensional space and +so let's say it's + + align:start position:0% +so let's say it's + + + align:start position:0% +so let's say it's +here okay and so I have + + align:start position:0% + + + + align:start position:0% + +my let's say Y is here and I also have a + + align:start position:0% +my let's say Y is here and I also have a + + + align:start position:0% +my let's say Y is here and I also have a +plane that's given by uh the vectors uh + + align:start position:0% +plane that's given by uh the vectors uh + + + align:start position:0% +plane that's given by uh the vectors uh +X1 + + align:start position:0% +X1 + + + align:start position:0% +X1 +transpose X2 transpose which is by the + + align:start position:0% +transpose X2 transpose which is by the + + + align:start position:0% +transpose X2 transpose which is by the +way a one + + align:start position:0% +way a one + + + align:start position:0% +way a one +uh sorry uh that's not what I want to + + align:start position:0% + + + + align:start position:0% + +do I'm going to say that n is equal to 3 + + align:start position:0% +do I'm going to say that n is equal to 3 + + + align:start position:0% +do I'm going to say that n is equal to 3 +and that P is equal to two so I + + align:start position:0% +and that P is equal to two so I + + + align:start position:0% +and that P is equal to two so I +basically have two vectors one + + align:start position:0% +basically have two vectors one + + + align:start position:0% +basically have two vectors one +one and uh another one let's let's + + align:start position:0% +one and uh another one let's let's + + + align:start position:0% +one and uh another one let's let's +assume that it's for example uh I don't + + align:start position:0% +assume that it's for example uh I don't + + + align:start position:0% +assume that it's for example uh I don't +know uh AB b + + align:start position:0% +know uh AB b + + + align:start position:0% +know uh AB b +c so those are my two vectors right this + + align:start position:0% +c so those are my two vectors right this + + + align:start position:0% +c so those are my two vectors right this +is + + align:start position:0% + + + + align:start position:0% + +X1 and this is + + align:start position:0% +X1 and this is + + + align:start position:0% +X1 and this is +X2 okay and those are my three + + align:start position:0% +X2 okay and those are my three + + + align:start position:0% +X2 okay and those are my three +observations for this guy so what I want + + align:start position:0% +observations for this guy so what I want + + + align:start position:0% +observations for this guy so what I want +when I minimize + + align:start position:0% + + + + align:start position:0% + +this I'm looking at the point which can + + align:start position:0% +this I'm looking at the point which can + + + align:start position:0% +this I'm looking at the point which can +be formed as a linear combination of The + + align:start position:0% +be formed as a linear combination of The + + + align:start position:0% +be formed as a linear combination of The +Columns of X and I'm trying to find the + + align:start position:0% +Columns of X and I'm trying to find the + + + align:start position:0% +Columns of X and I'm trying to find the +guy that's the closest to + + align:start position:0% +guy that's the closest to + + + align:start position:0% +guy that's the closest to +Y so what is it look like well the two + + align:start position:0% +Y so what is it look like well the two + + + align:start position:0% +Y so what is it look like well the two +points 111 is going to be say here + + align:start position:0% +points 111 is going to be say here + + + align:start position:0% +points 111 is going to be say here +that's the point 11 one and let's say + + align:start position:0% +that's the point 11 one and let's say + + + align:start position:0% +that's the point 11 one and let's say +that ABC is this + + align:start position:0% + + + + align:start position:0% + +point okay so now I have a line that + + align:start position:0% +point okay so now I have a line that + + + align:start position:0% +point okay so now I have a line that +goes through those two + + align:start position:0% + + + + align:start position:0% + +guys okay that's not really okay let's + + align:start position:0% +guys okay that's not really okay let's + + + align:start position:0% +guys okay that's not really okay let's +say it's going through those two guys + + align:start position:0% +say it's going through those two guys + + + align:start position:0% +say it's going through those two guys +and this is the line which can be formed + + align:start position:0% +and this is the line which can be formed + + + align:start position:0% +and this is the line which can be formed +by looking only at linear combination so + + align:start position:0% +by looking only at linear combination so + + + align:start position:0% +by looking only at linear combination so +this is the line for of X trans time t + + align:start position:0% +this is the line for of X trans time t + + + align:start position:0% +this is the line for of X trans time t +for T in + + align:start position:0% +for T in + + + align:start position:0% +for T in +R2 right that's this entire line that + + align:start position:0% +R2 right that's this entire line that + + + align:start position:0% +R2 right that's this entire line that +you can get why is it uh yeah sorry it's + + align:start position:0% +you can get why is it uh yeah sorry it's + + + align:start position:0% +you can get why is it uh yeah sorry it's +not just a line I also have to have t + + align:start position:0% +not just a line I also have to have t + + + align:start position:0% +not just a line I also have to have t +all the zeros thing right so that + + align:start position:0% +all the zeros thing right so that + + + align:start position:0% +all the zeros thing right so that +actually creates an entire plane which + + align:start position:0% +actually creates an entire plane which + + + align:start position:0% +actually creates an entire plane which +is going to be really hard for me to + + align:start position:0% +is going to be really hard for me to + + + align:start position:0% +is going to be really hard for me to +represent + + align:start position:0% +represent + + + align:start position:0% +represent +um I don't know I mean it's maybe I + + align:start position:0% +um I don't know I mean it's maybe I + + + align:start position:0% +um I don't know I mean it's maybe I +shouldn't do it in in uh in these + + align:start position:0% +shouldn't do it in in uh in these + + + align:start position:0% +shouldn't do it in in uh in these +Dimensions + + align:start position:0% + + + + align:start position:0% + +uh okay + + align:start position:0% +uh okay + + + align:start position:0% +uh okay +so I I'm going to do it like + + align:start position:0% +so I I'm going to do it like + + + align:start position:0% +so I I'm going to do it like +that so this plane here is the set of XT + + align:start position:0% +that so this plane here is the set of XT + + + align:start position:0% +that so this plane here is the set of XT +for T and + + align:start position:0% + + + + align:start position:0% + +R2 okay so that's a two-dimensional + + align:start position:0% +R2 okay so that's a two-dimensional + + + align:start position:0% +R2 okay so that's a two-dimensional +plane T definitely goes through zero and + + align:start position:0% +plane T definitely goes through zero and + + + align:start position:0% +plane T definitely goes through zero and +those are all these things right so + + align:start position:0% +those are all these things right so + + + align:start position:0% +those are all these things right so +think of a sheet of paper in three + + align:start position:0% +think of a sheet of paper in three + + + align:start position:0% +think of a sheet of paper in three +dimension those are the things I can get + + align:start position:0% +dimension those are the things I can get + + + align:start position:0% +dimension those are the things I can get +so now what I'm going to have is y is + + align:start position:0% +so now what I'm going to have is y is + + + align:start position:0% +so now what I'm going to have is y is +not necessarily in this + + align:start position:0% +not necessarily in this + + + align:start position:0% +not necessarily in this +plane Y is actually something in this + + align:start position:0% +plane Y is actually something in this + + + align:start position:0% +plane Y is actually something in this +plane X + + align:start position:0% + + + + align:start position:0% + +beta plus some + + align:start position:0% +beta plus some + + + align:start position:0% +beta plus some +Epsilon + + align:start position:0% +Epsilon + + + align:start position:0% +Epsilon +okay Y is X + + align:start position:0% + + + + align:start position:0% + +beta plus Epsilon so I start from this + + align:start position:0% +beta plus Epsilon so I start from this + + + align:start position:0% +beta plus Epsilon so I start from this +plane and then I have this Epsilon that + + align:start position:0% +plane and then I have this Epsilon that + + + align:start position:0% +plane and then I have this Epsilon that +pushes me maybe outside of this plane + + align:start position:0% +pushes me maybe outside of this plane + + + align:start position:0% +pushes me maybe outside of this plane +and what Le squares is doing is saying + + align:start position:0% +and what Le squares is doing is saying + + + align:start position:0% +and what Le squares is doing is saying +well I know that EP should be fairly + + align:start position:0% +well I know that EP should be fairly + + + align:start position:0% +well I know that EP should be fairly +small so the only thing I'm going to be + + align:start position:0% +small so the only thing I'm going to be + + + align:start position:0% +small so the only thing I'm going to be +doing that actually makes sense is to + + align:start position:0% +doing that actually makes sense is to + + + align:start position:0% +doing that actually makes sense is to +take Y and look at find the point that's + + align:start position:0% +take Y and look at find the point that's + + + align:start position:0% +take Y and look at find the point that's +on this plane that's the closest to it + + align:start position:0% +on this plane that's the closest to it + + + align:start position:0% +on this plane that's the closest to it +and that corresponds to doing an + + align:start position:0% +and that corresponds to doing an + + + align:start position:0% +and that corresponds to doing an +orthogonal projection of Y onto this + + align:start position:0% +orthogonal projection of Y onto this + + + align:start position:0% +orthogonal projection of Y onto this +thing and that's actually exactly X beta + + align:start position:0% + + + + align:start position:0% + +hat okay so in one dimension just uh + + align:start position:0% +hat okay so in one dimension just uh + + + align:start position:0% +hat okay so in one dimension just uh +because this is actually a little hard + + align:start position:0% +because this is actually a little hard + + + align:start position:0% +because this is actually a little hard +in one + + align:start position:0% + + + + align:start position:0% + +dimension uh so + + align:start position:0% +dimension uh so + + + align:start position:0% +dimension uh so +so so that's if p is equal to + + align:start position:0% +so so that's if p is equal to + + + align:start position:0% +so so that's if p is equal to +one okay so let's say this is my point + + align:start position:0% +one okay so let's say this is my point + + + align:start position:0% +one okay so let's say this is my point +and then I have Y which is in two + + align:start position:0% +and then I have Y which is in two + + + align:start position:0% +and then I have Y which is in two +Dimensions so this is all on the + + align:start position:0% + + + + align:start position:0% + +plane what it does this is my the point + + align:start position:0% +plane what it does this is my the point + + + align:start position:0% +plane what it does this is my the point +that's right here is actually X beta + + align:start position:0% +that's right here is actually X beta + + + align:start position:0% +that's right here is actually X beta +hat that's how you find X beta hat you + + align:start position:0% +hat that's how you find X beta hat you + + + align:start position:0% +hat that's how you find X beta hat you +take your point Y and you project it on + + align:start position:0% +take your point Y and you project it on + + + align:start position:0% +take your point Y and you project it on +the linear span of The Columns of X and + + align:start position:0% +the linear span of The Columns of X and + + + align:start position:0% +the linear span of The Columns of X and +that's X beta hat this does not tell you + + align:start position:0% +that's X beta hat this does not tell you + + + align:start position:0% +that's X beta hat this does not tell you +exactly what beta should be and if you + + align:start position:0% +exactly what beta should be and if you + + + align:start position:0% +exactly what beta should be and if you +know a little bit of linear algebra it's + + align:start position:0% +know a little bit of linear algebra it's + + + align:start position:0% +know a little bit of linear algebra it's +pretty clear because you if you want to + + align:start position:0% +pretty clear because you if you want to + + + align:start position:0% +pretty clear because you if you want to +find beta hat that means you should be + + align:start position:0% +find beta hat that means you should be + + + align:start position:0% +find beta hat that means you should be +able to find the coordinates of a point + + align:start position:0% +able to find the coordinates of a point + + + align:start position:0% +able to find the coordinates of a point +in the system of uh of columns of X and + + align:start position:0% +in the system of uh of columns of X and + + + align:start position:0% +in the system of uh of columns of X and +if those guys are redundant there's not + + align:start position:0% +if those guys are redundant there's not + + + align:start position:0% +if those guys are redundant there's not +going to be a unique coordinate for this + + align:start position:0% +going to be a unique coordinate for this + + + align:start position:0% +going to be a unique coordinate for this +guys right so that's why it's actually + + align:start position:0% +guys right so that's why it's actually + + + align:start position:0% +guys right so that's why it's actually +not not easy to find but X beta hat is + + align:start position:0% +not not easy to find but X beta hat is + + + align:start position:0% +not not easy to find but X beta hat is +uniquely defined it's a projection yeah + + align:start position:0% +uniquely defined it's a projection yeah + + + align:start position:0% +uniquely defined it's a projection yeah +epon Y no Epsilon is the vector that + + align:start position:0% +epon Y no Epsilon is the vector that + + + align:start position:0% +epon Y no Epsilon is the vector that +goes from from right so there's so + + align:start position:0% +goes from from right so there's so + + + align:start position:0% +goes from from right so there's so +there's a true X + + align:start position:0% +there's a true X + + + align:start position:0% +there's a true X +beta that's the true one does it's it's + + align:start position:0% +beta that's the true one does it's it's + + + align:start position:0% +beta that's the true one does it's it's +not clear I mean X beta hat is unlikely + + align:start position:0% +not clear I mean X beta hat is unlikely + + + align:start position:0% +not clear I mean X beta hat is unlikely +to be exactly equal to X beta right and + + align:start position:0% +to be exactly equal to X beta right and + + + align:start position:0% +to be exactly equal to X beta right and +then the Epsilon is the one that starts + + align:start position:0% +then the Epsilon is the one that starts + + + align:start position:0% +then the Epsilon is the one that starts +from this line it's the vector that + + align:start position:0% +from this line it's the vector that + + + align:start position:0% +from this line it's the vector that +pushes you away so really this is this + + align:start position:0% +pushes you away so really this is this + + + align:start position:0% +pushes you away so really this is this +Vector that's + + align:start position:0% +Vector that's + + + align:start position:0% +Vector that's +Epsilon so it's not a length right the + + align:start position:0% +Epsilon so it's not a length right the + + + align:start position:0% +Epsilon so it's not a length right the +length of Epsilon is the distance but + + align:start position:0% +length of Epsilon is the distance but + + + align:start position:0% +length of Epsilon is the distance but +Epsilon is just the actual Vector that + + align:start position:0% +Epsilon is just the actual Vector that + + + align:start position:0% +Epsilon is just the actual Vector that +takes you from one to the + + align:start position:0% + + + + align:start position:0% + +other okay so this is all in two + + align:start position:0% +other okay so this is all in two + + + align:start position:0% +other okay so this is all in two +Dimension it's probably much clearer + + align:start position:0% +Dimension it's probably much clearer + + + align:start position:0% +Dimension it's probably much clearer +than what's + + align:start position:0% + + + + align:start position:0% + +here and so here I claim that this x + + align:start position:0% +here and so here I claim that this x + + + align:start position:0% +here and so here I claim that this x +beta hat so from this picture I sort of + + align:start position:0% +beta hat so from this picture I sort of + + + align:start position:0% +beta hat so from this picture I sort of +implicitly claim that forming + + align:start position:0% + + + + align:start position:0% + +this this operator that takes Y and Maps + + align:start position:0% +this this operator that takes Y and Maps + + + align:start position:0% +this this operator that takes Y and Maps +it into this Vector x * X transpose y + + align:start position:0% +it into this Vector x * X transpose y + + + align:start position:0% +it into this Vector x * X transpose y +blah blah blah this should actually be + + align:start position:0% +blah blah blah this should actually be + + + align:start position:0% +blah blah blah this should actually be +equal to the + + align:start position:0% +equal to the + + + align:start position:0% +equal to the +projection of + + align:start position:0% +projection of + + + align:start position:0% +projection of +Y + + align:start position:0% +Y + + + align:start position:0% +Y +onto the linear + + align:start position:0% + + + + align:start position:0% + +span of The + + align:start position:0% +span of The + + + align:start position:0% +span of The +Columns of X right that's that's what I + + align:start position:0% +Columns of X right that's that's what I + + + align:start position:0% +Columns of X right that's that's what I +just drew for you and what it means is + + align:start position:0% +just drew for you and what it means is + + + align:start position:0% +just drew for you and what it means is +that this Matrix must be the projection + + align:start position:0% + + + + align:start position:0% + +Matrix okay so of course anybody who is + + align:start position:0% +Matrix okay so of course anybody who is + + + align:start position:0% +Matrix okay so of course anybody who is +who knows linear algebra right here okay + + align:start position:0% +who knows linear algebra right here okay + + + align:start position:0% +who knows linear algebra right here okay +well so uh so what is the what are the + + align:start position:0% +well so uh so what is the what are the + + + align:start position:0% +well so uh so what is the what are the +conditions that a projection Matrix + + align:start position:0% +conditions that a projection Matrix + + + align:start position:0% +conditions that a projection Matrix +should be + + align:start position:0% +should be + + + align:start position:0% +should be +satisfying squares to itself squares to + + align:start position:0% +satisfying squares to itself squares to + + + align:start position:0% +satisfying squares to itself squares to +itself right if I project twice I'm not + + align:start position:0% +itself right if I project twice I'm not + + + align:start position:0% +itself right if I project twice I'm not +moving if I keep on iterating projection + + align:start position:0% +moving if I keep on iterating projection + + + align:start position:0% +moving if I keep on iterating projection +once I'm in the space I'm projecting + + align:start position:0% +once I'm in the space I'm projecting + + + align:start position:0% +once I'm in the space I'm projecting +onto I'm not moving what + + align:start position:0% + + + + align:start position:0% + +else does it have to be symmetric Maybe + + align:start position:0% +else does it have to be symmetric Maybe + + + align:start position:0% +else does it have to be symmetric Maybe +it's an orthal yeah so this is an + + align:start position:0% +it's an orthal yeah so this is an + + + align:start position:0% +it's an orthal yeah so this is an +orthogonal projection it has to be uh uh + + align:start position:0% +orthogonal projection it has to be uh uh + + + align:start position:0% +orthogonal projection it has to be uh uh +symmetric and uh that's pretty much it + + align:start position:0% +symmetric and uh that's pretty much it + + + align:start position:0% +symmetric and uh that's pretty much it +right so those from those things you can + + align:start position:0% +right so those from those things you can + + + align:start position:0% +right so those from those things you can +actually get quite a bit of things but + + align:start position:0% +actually get quite a bit of things but + + + align:start position:0% +actually get quite a bit of things but +what's interesting is that if you + + align:start position:0% +what's interesting is that if you + + + align:start position:0% +what's interesting is that if you +actually look at the igen values of this + + align:start position:0% +actually look at the igen values of this + + + align:start position:0% +actually look at the igen values of this +Matrix they should be either zero or one + + align:start position:0% +Matrix they should be either zero or one + + + align:start position:0% +Matrix they should be either zero or one +essentially and they're one if uh the + + align:start position:0% +essentially and they're one if uh the + + + align:start position:0% +essentially and they're one if uh the +igen vector Associated is within the + + align:start position:0% +igen vector Associated is within the + + + align:start position:0% +igen vector Associated is within the +space and zero otherwise and so that's + + align:start position:0% +space and zero otherwise and so that's + + + align:start position:0% +space and zero otherwise and so that's +basically what you can check this is not + + align:start position:0% +basically what you can check this is not + + + align:start position:0% +basically what you can check this is not +an exercise in the algebra so I'm not + + align:start position:0% +an exercise in the algebra so I'm not + + + align:start position:0% +an exercise in the algebra so I'm not +going to go too much into those details + + align:start position:0% +going to go too much into those details + + + align:start position:0% +going to go too much into those details +but this is essentially what you want to + + align:start position:0% +but this is essentially what you want to + + + align:start position:0% +but this is essentially what you want to +keep in mind what's associated to + + align:start position:0% +keep in mind what's associated to + + + align:start position:0% +keep in mind what's associated to +orthogonal projections is Pythagoras + + align:start position:0% +orthogonal projections is Pythagoras + + + align:start position:0% +orthogonal projections is Pythagoras +Theorem and that's something that's + + align:start position:0% +Theorem and that's something that's + + + align:start position:0% +Theorem and that's something that's +going to be useful for us what it's + + align:start position:0% +going to be useful for us what it's + + + align:start position:0% +going to be useful for us what it's +essentially telling me is that if I look + + align:start position:0% +essentially telling me is that if I look + + + align:start position:0% +essentially telling me is that if I look +at this Norm squared it's equal to this + + align:start position:0% +at this Norm squared it's equal to this + + + align:start position:0% +at this Norm squared it's equal to this +Norm squared sorry this Norm squar plus + + align:start position:0% +Norm squared sorry this Norm squar plus + + + align:start position:0% +Norm squared sorry this Norm squar plus +this Norm squar is equal to this norm + + align:start position:0% +this Norm squar is equal to this norm + + + align:start position:0% +this Norm squar is equal to this norm +squar and that's something the norm of Y + + align:start position:0% +squar and that's something the norm of Y + + + align:start position:0% +squar and that's something the norm of Y +squ right so Pythagoras + + align:start position:0% + + + + align:start position:0% + +tells me that the norm of + + align:start position:0% +tells me that the norm of + + + align:start position:0% +tells me that the norm of +y^2 is equal to the norm of X beta hat + + align:start position:0% + + + + align:start position:0% + +squ plus the norm of y - x beta head + + align:start position:0% + + + + align:start position:0% + +squ + + align:start position:0% +squ + + + align:start position:0% +squ +agreed right it's just because I have I + + align:start position:0% +agreed right it's just because I have I + + + align:start position:0% +agreed right it's just because I have I +have a straight angle here okay so + + align:start position:0% +have a straight angle here okay so + + + align:start position:0% +have a straight angle here okay so +that's this plus this is equal to this + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +now to Define this I made no assumption + + align:start position:0% +now to Define this I made no assumption + + + align:start position:0% +now to Define this I made no assumption +Epsilon could could be as wild I was + + align:start position:0% +Epsilon could could be as wild I was + + + align:start position:0% +Epsilon could could be as wild I was +just crossing my finger that Epsilon was + + align:start position:0% +just crossing my finger that Epsilon was + + + align:start position:0% +just crossing my finger that Epsilon was +actually small enough that it would make + + align:start position:0% +actually small enough that it would make + + + align:start position:0% +actually small enough that it would make +sense to project onto the linear span + + align:start position:0% +sense to project onto the linear span + + + align:start position:0% +sense to project onto the linear span +because I implicitly assumed that + + align:start position:0% +because I implicitly assumed that + + + align:start position:0% +because I implicitly assumed that +Epsilon did not take me all the way + + align:start position:0% +Epsilon did not take me all the way + + + align:start position:0% +Epsilon did not take me all the way +there so that I'm actually it sort of + + align:start position:0% +there so that I'm actually it sort of + + + align:start position:0% +there so that I'm actually it sort of +makes sense to project back and so for + + align:start position:0% +makes sense to project back and so for + + + align:start position:0% +makes sense to project back and so for +that I need to somehow make assumptions + + align:start position:0% +that I need to somehow make assumptions + + + align:start position:0% +that I need to somehow make assumptions +that Epsilon is well behaved and that + + align:start position:0% +that Epsilon is well behaved and that + + + align:start position:0% +that Epsilon is well behaved and that +it's not completely wild that it's sort + + align:start position:0% +it's not completely wild that it's sort + + + align:start position:0% +it's not completely wild that it's sort +of moving + + align:start position:0% +of moving + + + align:start position:0% +of moving +in uniformly in directions around in in + + align:start position:0% +in uniformly in directions around in in + + + align:start position:0% +in uniformly in directions around in in +all directions of the space there's no + + align:start position:0% +all directions of the space there's no + + + align:start position:0% +all directions of the space there's no +privileged Direction where it's always + + align:start position:0% +privileged Direction where it's always + + + align:start position:0% +privileged Direction where it's always +going otherwise I'm going to make a + + align:start position:0% +going otherwise I'm going to make a + + + align:start position:0% +going otherwise I'm going to make a +systematic error and I need that those + + align:start position:0% +systematic error and I need that those + + + align:start position:0% +systematic error and I need that those +epsilons are going to average + + align:start position:0% +epsilons are going to average + + + align:start position:0% +epsilons are going to average +somehow okay so here are the uh + + align:start position:0% +somehow okay so here are the uh + + + align:start position:0% +somehow okay so here are the uh +assumptions we're going to be making so + + align:start position:0% +assumptions we're going to be making so + + + align:start position:0% +assumptions we're going to be making so +that we can actually do some statistical + + align:start position:0% +that we can actually do some statistical + + + align:start position:0% +that we can actually do some statistical +inference the first one is that the + + align:start position:0% +inference the first one is that the + + + align:start position:0% +inference the first one is that the +design Matrix is + + align:start position:0% +design Matrix is + + + align:start position:0% +design Matrix is +deterministic okay so I started by + + align:start position:0% +deterministic okay so I started by + + + align:start position:0% +deterministic okay so I started by +saying the X I have XI Yi and maybe they + + align:start position:0% +saying the X I have XI Yi and maybe they + + + align:start position:0% +saying the X I have XI Yi and maybe they +independent here they are but the excis + + align:start position:0% +independent here they are but the excis + + + align:start position:0% +independent here they are but the excis +I want to think as deterministic if + + align:start position:0% +I want to think as deterministic if + + + align:start position:0% +I want to think as deterministic if +they're not deterministic it can sort of + + align:start position:0% +they're not deterministic it can sort of + + + align:start position:0% +they're not deterministic it can sort of +condition on them but otherwise it's + + align:start position:0% +condition on them but otherwise it's + + + align:start position:0% +condition on them but otherwise it's +very difficult to think about this thing + + align:start position:0% +very difficult to think about this thing + + + align:start position:0% +very difficult to think about this thing +if I think of those entries as being + + align:start position:0% +if I think of those entries as being + + + align:start position:0% +if I think of those entries as being +random because then I have the inverse + + align:start position:0% +random because then I have the inverse + + + align:start position:0% +random because then I have the inverse +of a random Matrix and Things become + + align:start position:0% +of a random Matrix and Things become + + + align:start position:0% +of a random Matrix and Things become +very very complicated so we're going to + + align:start position:0% +very very complicated so we're going to + + + align:start position:0% +very very complicated so we're going to +think of those guys as being + + align:start position:0% +think of those guys as being + + + align:start position:0% +think of those guys as being +deterministic we're going to think of + + align:start position:0% +deterministic we're going to think of + + + align:start position:0% +deterministic we're going to think of +the model as being + + align:start position:0% +the model as being + + + align:start position:0% +the model as being +homoskedastic and actually let me come + + align:start position:0% +homoskedastic and actually let me come + + + align:start position:0% +homoskedastic and actually let me come +back to this in a second homoskedastic + + align:start position:0% +back to this in a second homoskedastic + + + align:start position:0% +back to this in a second homoskedastic +well I mean if you try to find the + + align:start position:0% +well I mean if you try to find the + + + align:start position:0% +well I mean if you try to find the +atmology of this word homo means the + + align:start position:0% +atmology of this word homo means the + + + align:start position:0% +atmology of this word homo means the +same skas means scaling so what I want + + align:start position:0% +same skas means scaling so what I want + + + align:start position:0% +same skas means scaling so what I want +to say is that the epsilons have the + + align:start position:0% +to say is that the epsilons have the + + + align:start position:0% +to say is that the epsilons have the +same scaling and since my third + + align:start position:0% +same scaling and since my third + + + align:start position:0% +same scaling and since my third +assumption is that Epsilon is + + align:start position:0% +assumption is that Epsilon is + + + align:start position:0% +assumption is that Epsilon is +gussan then essentially what I'm going + + align:start position:0% +gussan then essentially what I'm going + + + align:start position:0% +gussan then essentially what I'm going +to want is that they all share the same + + align:start position:0% +to want is that they all share the same + + + align:start position:0% +to want is that they all share the same +Sigma + + align:start position:0% +Sigma + + + align:start position:0% +Sigma +squared they're independent so this is + + align:start position:0% +squared they're independent so this is + + + align:start position:0% +squared they're independent so this is +definitely the identity ciance Matrix + + align:start position:0% +definitely the identity ciance Matrix + + + align:start position:0% +definitely the identity ciance Matrix +and I want them to be centered as well + + align:start position:0% +and I want them to be centered as well + + + align:start position:0% +and I want them to be centered as well +that means that I there's no direction + + align:start position:0% +that means that I there's no direction + + + align:start position:0% +that means that I there's no direction +that I'm always privileging when I'm + + align:start position:0% +that I'm always privileging when I'm + + + align:start position:0% +that I'm always privileging when I'm +moving away from my uh plane there okay + + align:start position:0% +moving away from my uh plane there okay + + + align:start position:0% +moving away from my uh plane there okay +so these are important + + align:start position:0% +so these are important + + + align:start position:0% +so these are important +conditions if it depends on how much + + align:start position:0% +conditions if it depends on how much + + + align:start position:0% +conditions if it depends on how much +inference you want to do right if you + + align:start position:0% +inference you want to do right if you + + + align:start position:0% +inference you want to do right if you +want to write T Test you need all these + + align:start position:0% +want to write T Test you need all these + + + align:start position:0% +want to write T Test you need all these +assumptions but if you only want to + + align:start position:0% +assumptions but if you only want to + + + align:start position:0% +assumptions but if you only want to +write for example uh the fact that your + + align:start position:0% +write for example uh the fact that your + + + align:start position:0% +write for example uh the fact that your +lead squares estimator is consistent you + + align:start position:0% +lead squares estimator is consistent you + + + align:start position:0% +lead squares estimator is consistent you +really just need the fact that Epsilon + + align:start position:0% +really just need the fact that Epsilon + + + align:start position:0% +really just need the fact that Epsilon +has variant Sigma + + align:start position:0% +has variant Sigma + + + align:start position:0% +has variant Sigma +Square the the fact that it's Gan won't + + align:start position:0% +Square the the fact that it's Gan won't + + + align:start position:0% +Square the the fact that it's Gan won't +matter just like gaussianity doesn't + + align:start position:0% +matter just like gaussianity doesn't + + + align:start position:0% +matter just like gaussianity doesn't +matter for a law of large number yeah so + + align:start position:0% +matter for a law of large number yeah so + + + align:start position:0% +matter for a law of large number yeah so +the first assumption + + align:start position:0% + + + + align:start position:0% + +that1 x x is the Matrix yeah those + + align:start position:0% +that1 x x is the Matrix yeah those + + + align:start position:0% +that1 x x is the Matrix yeah those +areand no that's the + + align:start position:0% + + + + align:start position:0% + +Assumption I you collect + + align:start position:0% + + + + align:start position:0% + +data yeah + + align:start position:0% +data yeah + + + align:start position:0% +data yeah +so this is for the purpose of the + + align:start position:0% +so this is for the purpose of the + + + align:start position:0% +so this is for the purpose of the +analysis right I can actually assume + + align:start position:0% +analysis right I can actually assume + + + align:start position:0% +analysis right I can actually assume +that I look at my data and I think of + + align:start position:0% +that I look at my data and I think of + + + align:start position:0% +that I look at my data and I think of +this right so what is the difference + + align:start position:0% +this right so what is the difference + + + align:start position:0% +this right so what is the difference +between thinking of data as + + align:start position:0% +between thinking of data as + + + align:start position:0% +between thinking of data as +deterministic or thinking of it as + + align:start position:0% +deterministic or thinking of it as + + + align:start position:0% +deterministic or thinking of it as +random when I talked about random data + + align:start position:0% +random when I talked about random data + + + align:start position:0% +random when I talked about random data +the only assumptions that I made were + + align:start position:0% +the only assumptions that I made were + + + align:start position:0% +the only assumptions that I made were +about the distribution I said well if my + + align:start position:0% +about the distribution I said well if my + + + align:start position:0% +about the distribution I said well if my +X is a random variable I want it to have + + align:start position:0% +X is a random variable I want it to have + + + align:start position:0% +X is a random variable I want it to have +this variance and I want it to have + + align:start position:0% +this variance and I want it to have + + + align:start position:0% +this variance and I want it to have +maybe this distribution things like this + + align:start position:0% +maybe this distribution things like this + + + align:start position:0% +maybe this distribution things like this +here I'm actually if I'm actually making + + align:start position:0% +here I'm actually if I'm actually making + + + align:start position:0% +here I'm actually if I'm actually making +the an assumption on the values that I + + align:start position:0% +the an assumption on the values that I + + + align:start position:0% +the an assumption on the values that I +see I'm saying that the value that you + + align:start position:0% +see I'm saying that the value that you + + + align:start position:0% +see I'm saying that the value that you +give me + + align:start position:0% +give me + + + align:start position:0% +give me +is the Matrix is actually invertible X + + align:start position:0% +is the Matrix is actually invertible X + + + align:start position:0% +is the Matrix is actually invertible X +transpose X will be invertible so I've + + align:start position:0% +transpose X will be invertible so I've + + + align:start position:0% +transpose X will be invertible so I've +never done that before assuming that + + align:start position:0% +never done that before assuming that + + + align:start position:0% +never done that before assuming that +some random variable like you know + + align:start position:0% +some random variable like you know + + + align:start position:0% +some random variable like you know +assuming that some GA random variable + + align:start position:0% +assuming that some GA random variable + + + align:start position:0% +assuming that some GA random variable +was positive for example we don't do + + align:start position:0% +was positive for example we don't do + + + align:start position:0% +was positive for example we don't do +that because there's always some + + align:start position:0% +that because there's always some + + + align:start position:0% +that because there's always some +probability that things don't happen if + + align:start position:0% +probability that things don't happen if + + + align:start position:0% +probability that things don't happen if +you make things at random and so here + + align:start position:0% +you make things at random and so here + + + align:start position:0% +you make things at random and so here +I'm just going to say okay forget about + + align:start position:0% +I'm just going to say okay forget about + + + align:start position:0% +I'm just going to say okay forget about +here I'm actually it's basically a + + align:start position:0% +here I'm actually it's basically a + + + align:start position:0% +here I'm actually it's basically a +little stronger I start my assumption by + + align:start position:0% +little stronger I start my assumption by + + + align:start position:0% +little stronger I start my assumption by +saying the data that's given to me to me + + align:start position:0% +saying the data that's given to me to me + + + align:start position:0% +saying the data that's given to me to me +will actually satisfy those assumptions + + align:start position:0% +will actually satisfy those assumptions + + + align:start position:0% +will actually satisfy those assumptions +and that means that I don't actually + + align:start position:0% +and that means that I don't actually + + + align:start position:0% +and that means that I don't actually +need to make some random some modeling + + align:start position:0% +need to make some random some modeling + + + align:start position:0% +need to make some random some modeling +assumption on this thing because I'm + + align:start position:0% +assumption on this thing because I'm + + + align:start position:0% +assumption on this thing because I'm +actually putting directly the Assumption + + align:start position:0% +actually putting directly the Assumption + + + align:start position:0% +actually putting directly the Assumption +I want to see + + align:start position:0% + + + + align:start position:0% + +okay okay so here either I know Sigma + + align:start position:0% +okay okay so here either I know Sigma + + + align:start position:0% +okay okay so here either I know Sigma +square or I don't know Sigma Square so + + align:start position:0% +square or I don't know Sigma Square so + + + align:start position:0% +square or I don't know Sigma Square so +is that clear so essentially I'm + + align:start position:0% +is that clear so essentially I'm + + + align:start position:0% +is that clear so essentially I'm +assuming that I have this + + align:start position:0% +assuming that I have this + + + align:start position:0% +assuming that I have this +model where this guy now is + + align:start position:0% + + + + align:start position:0% + +deterministic and this is some + + align:start position:0% +deterministic and this is some + + + align:start position:0% +deterministic and this is some +multivaried Gan which means zero and + + align:start position:0% +multivaried Gan which means zero and + + + align:start position:0% +multivaried Gan which means zero and +ciance Matrix identity of RN right + + align:start position:0% +ciance Matrix identity of RN right + + + align:start position:0% +ciance Matrix identity of RN right +that's that's the model I'm + + align:start position:0% +that's that's the model I'm + + + align:start position:0% +that's that's the model I'm +assuming so and I'm observing this and + + align:start position:0% +assuming so and I'm observing this and + + + align:start position:0% +assuming so and I'm observing this and +I'm given this Matrix X where does this + + align:start position:0% +I'm given this Matrix X where does this + + + align:start position:0% +I'm given this Matrix X where does this +make sense right you could say well if I + + align:start position:0% +make sense right you could say well if I + + + align:start position:0% +make sense right you could say well if I +think of my Ros as being people and I'm + + align:start position:0% +think of my Ros as being people and I'm + + + align:start position:0% +think of my Ros as being people and I'm +collecting genes it's kind of a little + + align:start position:0% +collecting genes it's kind of a little + + + align:start position:0% +collecting genes it's kind of a little +intense to assume that I actually know + + align:start position:0% +intense to assume that I actually know + + + align:start position:0% +intense to assume that I actually know +ahead of time what I'm going to be + + align:start position:0% +ahead of time what I'm going to be + + + align:start position:0% +ahead of time what I'm going to be +seeing and that those things are + + align:start position:0% +seeing and that those things are + + + align:start position:0% +seeing and that those things are +deterministic that's true but it still + + align:start position:0% +deterministic that's true but it still + + + align:start position:0% +deterministic that's true but it still +does not prevent the analysis to go + + align:start position:0% +does not prevent the analysis to go + + + align:start position:0% +does not prevent the analysis to go +through for one and second a better + + align:start position:0% +through for one and second a better + + + align:start position:0% +through for one and second a better +example might be this uh Imaging example + + align:start position:0% +example might be this uh Imaging example + + + align:start position:0% +example might be this uh Imaging example +that I described where those X's are + + align:start position:0% +that I described where those X's are + + + align:start position:0% +that I described where those X's are +actually libraries right those are + + align:start position:0% +actually libraries right those are + + + align:start position:0% +actually libraries right those are +libraries of patterns that people have + + align:start position:0% +libraries of patterns that people have + + + align:start position:0% +libraries of patterns that people have +created maybe from Deep learning Nets or + + align:start position:0% +created maybe from Deep learning Nets or + + + align:start position:0% +created maybe from Deep learning Nets or +something like this but they've created + + align:start position:0% +something like this but they've created + + + align:start position:0% +something like this but they've created +patterns and they say that all images + + align:start position:0% +patterns and they say that all images + + + align:start position:0% +patterns and they say that all images +should be representable as a linear + + align:start position:0% +should be representable as a linear + + + align:start position:0% +should be representable as a linear +combination of those patterns and those + + align:start position:0% +combination of those patterns and those + + + align:start position:0% +combination of those patterns and those +patterns are somewhere in books so + + align:start position:0% +patterns are somewhere in books so + + + align:start position:0% +patterns are somewhere in books so +they're certainly deterministic + + align:start position:0% +they're certainly deterministic + + + align:start position:0% +they're certainly deterministic +everything that's actually written down + + align:start position:0% +everything that's actually written down + + + align:start position:0% +everything that's actually written down +in a book is as deterministic as it gets + + align:start position:0% +in a book is as deterministic as it gets + + + align:start position:0% +in a book is as deterministic as it gets +all + + align:start position:0% +all + + + align:start position:0% +all +right okay + + align:start position:0% +right okay + + + align:start position:0% +right okay +uh any questions about those assumptions + + align:start position:0% +uh any questions about those assumptions + + + align:start position:0% +uh any questions about those assumptions +those are the things we're going to be + + align:start position:0% +those are the things we're going to be + + + align:start position:0% +those are the things we're going to be +working with there's only three of them + + align:start position:0% +working with there's only three of them + + + align:start position:0% +working with there's only three of them +one is about X actually there's really + + align:start position:0% +one is about X actually there's really + + + align:start position:0% +one is about X actually there's really +two of them right I mean this guy + + align:start position:0% +two of them right I mean this guy + + + align:start position:0% +two of them right I mean this guy +already appears uh here right so there's + + align:start position:0% +already appears uh here right so there's + + + align:start position:0% +already appears uh here right so there's +two one on the noise one on the X's + + align:start position:0% +two one on the noise one on the X's + + + align:start position:0% +two one on the noise one on the X's +that's + + align:start position:0% + + + + align:start position:0% + +it those things allow us to do quite a + + align:start position:0% +it those things allow us to do quite a + + + align:start position:0% +it those things allow us to do quite a +bit they allow us to they allow + + align:start position:0% +bit they allow us to they allow + + + align:start position:0% +bit they allow us to they allow +me well that's actually + + align:start position:0% + + + + align:start position:0% + +okay they allow me uh to write the + + align:start position:0% +okay they allow me uh to write the + + + align:start position:0% +okay they allow me uh to write the +distribution of beta hat which is great + + align:start position:0% +distribution of beta hat which is great + + + align:start position:0% +distribution of beta hat which is great +right because when I know the + + align:start position:0% +right because when I know the + + + align:start position:0% +right because when I know the +distribution of my estimator I know its + + align:start position:0% +distribution of my estimator I know its + + + align:start position:0% +distribution of my estimator I know its +fluctuations if it's centered around the + + align:start position:0% +fluctuations if it's centered around the + + + align:start position:0% +fluctuations if it's centered around the +true parameter I know that it's going to + + align:start position:0% +true parameter I know that it's going to + + + align:start position:0% +true parameter I know that it's going to +be fluctuating around the true parameter + + align:start position:0% +be fluctuating around the true parameter + + + align:start position:0% +be fluctuating around the true parameter +and if you tell me what kind of + + align:start position:0% +and if you tell me what kind of + + + align:start position:0% +and if you tell me what kind of +distribution the fluctuations are I + + align:start position:0% +distribution the fluctuations are I + + + align:start position:0% +distribution the fluctuations are I +actually know how to build confidence + + align:start position:0% +actually know how to build confidence + + + align:start position:0% +actually know how to build confidence +intervals I know how to build tests I + + align:start position:0% +intervals I know how to build tests I + + + align:start position:0% +intervals I know how to build tests I +know how to build everything it's just + + align:start position:0% +know how to build everything it's just + + + align:start position:0% +know how to build everything it's just +like when I told you that ASM totically + + align:start position:0% +like when I told you that ASM totically + + + align:start position:0% +like when I told you that ASM totically +the empirical variance was gussan with + + align:start position:0% +the empirical variance was gussan with + + + align:start position:0% +the empirical variance was gussan with +mean uh uh Theta and standard deviation + + align:start position:0% +mean uh uh Theta and standard deviation + + + align:start position:0% +mean uh uh Theta and standard deviation +that depended on N Etc that's basically + + align:start position:0% +that depended on N Etc that's basically + + + align:start position:0% +that depended on N Etc that's basically +the only thing I needed and this is what + + align:start position:0% +the only thing I needed and this is what + + + align:start position:0% +the only thing I needed and this is what +I'm actually getting here + + align:start position:0% +I'm actually getting here + + + align:start position:0% +I'm actually getting here +so let me start with this + + align:start position:0% +so let me start with this + + + align:start position:0% +so let me start with this +statement so remember bet a hat + + align:start position:0% +statement so remember bet a hat + + + align:start position:0% +statement so remember bet a hat +satisfied this so I'm going to rewrite + + align:start position:0% +satisfied this so I'm going to rewrite + + + align:start position:0% +satisfied this so I'm going to rewrite +it here + + align:start position:0% + + + + align:start position:0% + +so beta + + align:start position:0% +so beta + + + align:start position:0% +so beta +hat was equal to X transpose + + align:start position:0% +hat was equal to X transpose + + + align:start position:0% +hat was equal to X transpose +X inverse X transpose y right that was + + align:start position:0% +X inverse X transpose y right that was + + + align:start position:0% +X inverse X transpose y right that was +the definition that we found and now I + + align:start position:0% +the definition that we found and now I + + + align:start position:0% +the definition that we found and now I +also know that + + align:start position:0% +also know that + + + align:start position:0% +also know that +y was equal to X beta plus Epsilon so + + align:start position:0% +y was equal to X beta plus Epsilon so + + + align:start position:0% +y was equal to X beta plus Epsilon so +let me just replace y by X beta plus + + align:start position:0% +let me just replace y by X beta plus + + + align:start position:0% +let me just replace y by X beta plus +Epsilon here + + align:start position:0% + + + + align:start position:0% + +yeah oh yeah that's X transpose thank + + align:start position:0% +yeah oh yeah that's X transpose thank + + + align:start position:0% +yeah oh yeah that's X transpose thank +you + + align:start position:0% + + + + align:start position:0% + +okay so uh I'm going to replace y by X + + align:start position:0% +okay so uh I'm going to replace y by X + + + align:start position:0% +okay so uh I'm going to replace y by X +beta plus Epsilon okay so + + align:start position:0% + + + + align:start position:0% + +that's + + align:start position:0% +that's + + + align:start position:0% +that's +okay and here comes the magic right + + align:start position:0% +okay and here comes the magic right + + + align:start position:0% +okay and here comes the magic right +I have an inverse of a matrix and then I + + align:start position:0% +I have an inverse of a matrix and then I + + + align:start position:0% +I have an inverse of a matrix and then I +have the true Matrix I have the original + + align:start position:0% +have the true Matrix I have the original + + + align:start position:0% +have the true Matrix I have the original +Matrix so this is actually the identity + + align:start position:0% +Matrix so this is actually the identity + + + align:start position:0% +Matrix so this is actually the identity +Time + + align:start position:0% +Time + + + align:start position:0% +Time +beta and now this guy well this is a gan + + align:start position:0% +beta and now this guy well this is a gan + + + align:start position:0% +beta and now this guy well this is a gan +right because this is a gan random + + align:start position:0% +right because this is a gan random + + + align:start position:0% +right because this is a gan random +vector and I just multiply it by a + + align:start position:0% +vector and I just multiply it by a + + + align:start position:0% +vector and I just multiply it by a +deterministic matrix so right so we're + + align:start position:0% +deterministic matrix so right so we're + + + align:start position:0% +deterministic matrix so right so we're +going to use the rule that if I have say + + align:start position:0% +going to use the rule that if I have say + + + align:start position:0% +going to use the rule that if I have say +epsilon which is + + align:start position:0% +epsilon which is + + + align:start position:0% +epsilon which is +n0 Sigma then B * Epsilon + + align:start position:0% +n0 Sigma then B * Epsilon + + + align:start position:0% +n0 Sigma then B * Epsilon +is n0 can somebody tell me what the + + align:start position:0% +is n0 can somebody tell me what the + + + align:start position:0% +is n0 can somebody tell me what the +cence Matrix of B Epsilon + + align:start position:0% + + + + align:start position:0% + +is it's just a + + align:start position:0% + + + + align:start position:0% + +matrix and for any Matrix I mean any + + align:start position:0% +matrix and for any Matrix I mean any + + + align:start position:0% +matrix and for any Matrix I mean any +Matrix that I can + + align:start position:0% +Matrix that I can + + + align:start position:0% +Matrix that I can +premultiply uh that I can post multiply + + align:start position:0% +premultiply uh that I can post multiply + + + align:start position:0% +premultiply uh that I can post multiply +with Epsilon right + + align:start position:0% +with Epsilon right + + + align:start position:0% +with Epsilon right +yeah B + + align:start position:0% +yeah B + + + align:start position:0% +yeah B +transpose and sigma is gone + + align:start position:0% + + + + align:start position:0% + +that's a matrix + + align:start position:0% +that's a matrix + + + align:start position:0% +that's a matrix +right + + align:start position:0% +right + + + align:start position:0% +right +almost anybody wants to take a guess at + + align:start position:0% +almost anybody wants to take a guess at + + + align:start position:0% +almost anybody wants to take a guess at +the last one I think we we've removed + + align:start position:0% +the last one I think we we've removed + + + align:start position:0% +the last one I think we we've removed +all all their + + align:start position:0% + + + + align:start position:0% + +possibilities it's B Sigma B + + align:start position:0% +possibilities it's B Sigma B + + + align:start position:0% +possibilities it's B Sigma B +transpose + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so if you ever answered to the question + + align:start position:0% +so if you ever answered to the question + + + align:start position:0% +so if you ever answered to the question +do you know gaon random vectors but you + + align:start position:0% +do you know gaon random vectors but you + + + align:start position:0% +do you know gaon random vectors but you +did not know that there's a gap in your + + align:start position:0% +did not know that there's a gap in your + + + align:start position:0% +did not know that there's a gap in your +knowledge that you need to fill because + + align:start position:0% +knowledge that you need to fill because + + + align:start position:0% +knowledge that you need to fill because +that's probably the most important + + align:start position:0% +that's probably the most important + + + align:start position:0% +that's probably the most important +property of gaan vectors when you take + + align:start position:0% +property of gaan vectors when you take + + + align:start position:0% +property of gaan vectors when you take +you multiply them by matrices you have a + + align:start position:0% +you multiply them by matrices you have a + + + align:start position:0% +you multiply them by matrices you have a +simple rule on how to update the ciance + + align:start position:0% +simple rule on how to update the ciance + + + align:start position:0% +simple rule on how to update the ciance +Matrix okay so here Sigma is the + + align:start position:0% +Matrix okay so here Sigma is the + + + align:start position:0% +Matrix okay so here Sigma is the +identity right and here this is the + + align:start position:0% +identity right and here this is the + + + align:start position:0% +identity right and here this is the +Matrix B that I had + + align:start position:0% +Matrix B that I had + + + align:start position:0% +Matrix B that I had +here so what this is is basically n some + + align:start position:0% +here so what this is is basically n some + + + align:start position:0% +here so what this is is basically n some +multivariate n of course then I'm going + + align:start position:0% +multivariate n of course then I'm going + + + align:start position:0% +multivariate n of course then I'm going +to have zero and so what I need to do is + + align:start position:0% +to have zero and so what I need to do is + + + align:start position:0% +to have zero and so what I need to do is +B times the identity time B transpose + + align:start position:0% +B times the identity time B transpose + + + align:start position:0% +B times the identity time B transpose +which is just BB + + align:start position:0% +which is just BB + + + align:start position:0% +which is just BB +transpose and what it's going to tell me + + align:start position:0% +transpose and what it's going to tell me + + + align:start position:0% +transpose and what it's going to tell me +it's it's X transpose + + align:start position:0% +it's it's X transpose + + + align:start position:0% +it's it's X transpose +X sorry that's + + align:start position:0% +X sorry that's + + + align:start position:0% +X sorry that's +inverse inverse X transpose and then the + + align:start position:0% +inverse inverse X transpose and then the + + + align:start position:0% +inverse inverse X transpose and then the +transpose of this guy which is + + align:start position:0% +transpose of this guy which is + + + align:start position:0% +transpose of this guy which is +X x transpose + + align:start position:0% +X x transpose + + + align:start position:0% +X x transpose +X inverse transpose but this Matrix is + + align:start position:0% +X inverse transpose but this Matrix is + + + align:start position:0% +X inverse transpose but this Matrix is +symmetric so I'm actually not going to + + align:start position:0% +symmetric so I'm actually not going to + + + align:start position:0% +symmetric so I'm actually not going to +make the transpose of this guy and + + align:start position:0% +make the transpose of this guy and + + + align:start position:0% +make the transpose of this guy and +again magic shows up inverse times The + + align:start position:0% +again magic shows up inverse times The + + + align:start position:0% +again magic shows up inverse times The +Matrix so those two guys cancel and so + + align:start position:0% +Matrix so those two guys cancel and so + + + align:start position:0% +Matrix so those two guys cancel and so +this is actually equal to Beta plus some + + align:start position:0% +this is actually equal to Beta plus some + + + align:start position:0% +this is actually equal to Beta plus some +n0 X transpose X + + align:start position:0% + + + + align:start position:0% + +inverse + + align:start position:0% + + + + align:start position:0% + +yeah so I just apply this rule + + align:start position:0% +yeah so I just apply this rule + + + align:start position:0% +yeah so I just apply this rule +right so if I multiply a ga a matrix by + + align:start position:0% +right so if I multiply a ga a matrix by + + + align:start position:0% +right so if I multiply a ga a matrix by +a gaan then let's say there this this + + align:start position:0% +a gaan then let's say there this this + + + align:start position:0% +a gaan then let's say there this this +gaan had mean zero which is the case of + + align:start position:0% +gaan had mean zero which is the case of + + + align:start position:0% +gaan had mean zero which is the case of +Epsilon here then the ciance Matrix that + + align:start position:0% +Epsilon here then the ciance Matrix that + + + align:start position:0% +Epsilon here then the ciance Matrix that +I get is B * the original cence Matrix + + align:start position:0% +I get is B * the original cence Matrix + + + align:start position:0% +I get is B * the original cence Matrix +time B transpose so all I did is write + + align:start position:0% +time B transpose so all I did is write + + + align:start position:0% +time B transpose so all I did is write +this Matrix times the identity times + + align:start position:0% +this Matrix times the identity times + + + align:start position:0% +this Matrix times the identity times +this Matrix + + align:start position:0% +this Matrix + + + align:start position:0% +this Matrix +transpose and the identity of course + + align:start position:0% +transpose and the identity of course + + + align:start position:0% +transpose and the identity of course +doesn't play any role so I can remove it + + align:start position:0% +doesn't play any role so I can remove it + + + align:start position:0% +doesn't play any role so I can remove it +it's just this Matrix then the Matrix + + align:start position:0% +it's just this Matrix then the Matrix + + + align:start position:0% +it's just this Matrix then the Matrix +transpose and what happens so right so + + align:start position:0% +transpose and what happens so right so + + + align:start position:0% +transpose and what happens so right so +what is the transpose of this Matrix so + + align:start position:0% +what is the transpose of this Matrix so + + + align:start position:0% +what is the transpose of this Matrix so +I sort of use the fact that if I look at + + align:start position:0% +I sort of use the fact that if I look at + + + align:start position:0% +I sort of use the fact that if I look at +X transpose X inverse X + + align:start position:0% +X transpose X inverse X + + + align:start position:0% +X transpose X inverse X +transpose and now I look at the whole + + align:start position:0% +transpose and now I look at the whole + + + align:start position:0% +transpose and now I look at the whole +transpose of this + + align:start position:0% +transpose of this + + + align:start position:0% +transpose of this +thing that's actually equal to and I use + + align:start position:0% +thing that's actually equal to and I use + + + align:start position:0% +thing that's actually equal to and I use +the rule that uh AB transpose is B + + align:start position:0% +the rule that uh AB transpose is B + + + align:start position:0% +the rule that uh AB transpose is B +transpose a transpose let me finish and + + align:start position:0% +transpose a transpose let me finish and + + + align:start position:0% +transpose a transpose let me finish and +it's uh + + align:start position:0% +it's uh + + + align:start position:0% +it's uh +x x transpose + + align:start position:0% +x x transpose + + + align:start position:0% +x x transpose +X + + align:start position:0% + + + + align:start position:0% + +inverse yes + + align:start position:0% + + + + align:start position:0% + +umon sare oh thank you there's a sigma + + align:start position:0% +umon sare oh thank you there's a sigma + + + align:start position:0% +umon sare oh thank you there's a sigma +Square somewhere so this was Sigma + + align:start position:0% +Square somewhere so this was Sigma + + + align:start position:0% +Square somewhere so this was Sigma +Square Times the this was Sigma Square + + align:start position:0% +Square Times the this was Sigma Square + + + align:start position:0% +Square Times the this was Sigma Square +Times the identity so I could just pick + + align:start position:0% +Times the identity so I could just pick + + + align:start position:0% +Times the identity so I could just pick +up a sigma Square + + align:start position:0% + + + + align:start position:0% + +everywhere right so here in our case so + + align:start position:0% +everywhere right so here in our case so + + + align:start position:0% +everywhere right so here in our case so +for + + align:start position:0% + + + + align:start position:0% + +Epsilon this is this is uh + + align:start position:0% +Epsilon this is this is uh + + + align:start position:0% +Epsilon this is this is uh +Sigma right Sigma Square time the + + align:start position:0% +Sigma right Sigma Square time the + + + align:start position:0% +Sigma right Sigma Square time the +identity that's my ciance + + align:start position:0% + + + + align:start position:0% + +Matrix youing + + align:start position:0% +Matrix youing + + + align:start position:0% +Matrix youing +perplex + + align:start position:0% + + + + align:start position:0% + +just oh it should not be any estimator + + align:start position:0% +just oh it should not be any estimator + + + align:start position:0% +just oh it should not be any estimator +is a random variable oh yeah that's a + + align:start position:0% +is a random variable oh yeah that's a + + + align:start position:0% +is a random variable oh yeah that's a +good + + align:start position:0% + + + + align:start position:0% + +point and uh I have not told you that + + align:start position:0% +point and uh I have not told you that + + + align:start position:0% +point and uh I have not told you that +this was the maximum likelihood + + align:start position:0% +this was the maximum likelihood + + + align:start position:0% +this was the maximum likelihood +estimator just yet right but an + + align:start position:0% +estimator just yet right but an + + + align:start position:0% +estimator just yet right but an +estimator is a random variable + + align:start position:0% +estimator is a random variable + + + align:start position:0% +estimator is a random variable +there's a word some people use estimate + + align:start position:0% +there's a word some people use estimate + + + align:start position:0% +there's a word some people use estimate +just to differentiate the estimator + + align:start position:0% +just to differentiate the estimator + + + align:start position:0% +just to differentiate the estimator +while you're doing the analysis with + + align:start position:0% +while you're doing the analysis with + + + align:start position:0% +while you're doing the analysis with +random variables and the values when you + + align:start position:0% +random variables and the values when you + + + align:start position:0% +random variables and the values when you +plug in the numbers in + + align:start position:0% +plug in the numbers in + + + align:start position:0% +plug in the numbers in +there uh but then of course people use + + align:start position:0% +there uh but then of course people use + + + align:start position:0% +there uh but then of course people use +estimate because it's shorter so then + + align:start position:0% +estimate because it's shorter so then + + + align:start position:0% +estimate because it's shorter so then +it's confusing and um all right so any + + align:start position:0% +it's confusing and um all right so any + + + align:start position:0% +it's confusing and um all right so any +questions about this computation did I + + align:start position:0% +questions about this computation did I + + + align:start position:0% +questions about this computation did I +forget any other Greek letter along the + + align:start position:0% +forget any other Greek letter along the + + + align:start position:0% +forget any other Greek letter along the +way all right I think we're good so um + + align:start position:0% +way all right I think we're good so um + + + align:start position:0% +way all right I think we're good so um +one thing that it says and actually uh + + align:start position:0% +one thing that it says and actually uh + + + align:start position:0% +one thing that it says and actually uh +thank you for warning this out I said + + align:start position:0% +thank you for warning this out I said + + + align:start position:0% +thank you for warning this out I said +there's actually a little hidden + + align:start position:0% +there's actually a little hidden + + + align:start position:0% +there's actually a little hidden +statement there okay by the way this + + align:start position:0% +statement there okay by the way this + + + align:start position:0% +statement there okay by the way this +answers this question right beta hat is + + align:start position:0% +answers this question right beta hat is + + + align:start position:0% +answers this question right beta hat is +of the form beta plus something that's + + align:start position:0% +of the form beta plus something that's + + + align:start position:0% +of the form beta plus something that's +centered so it's indeed of the form uh + + align:start position:0% +centered so it's indeed of the form uh + + + align:start position:0% +centered so it's indeed of the form uh +Gan with mean beta and cence Matrix + + align:start position:0% +Gan with mean beta and cence Matrix + + + align:start position:0% +Gan with mean beta and cence Matrix +Sigma Square X transpose X inverse + + align:start position:0% + + + + align:start position:0% + +right so that's very nice uh as long as + + align:start position:0% +right so that's very nice uh as long as + + + align:start position:0% +right so that's very nice uh as long as +X transpose X is not huge I'm going to + + align:start position:0% +X transpose X is not huge I'm going to + + + align:start position:0% +X transpose X is not huge I'm going to +have something that that is close to + + align:start position:0% +have something that that is close to + + + align:start position:0% +have something that that is close to +what I + + align:start position:0% +what I + + + align:start position:0% +what I +want oh sorry extra suppose X inverse is + + align:start position:0% +want oh sorry extra suppose X inverse is + + + align:start position:0% +want oh sorry extra suppose X inverse is +not + + align:start position:0% + + + + align:start position:0% + +huge all right so there's a hidden claim + + align:start position:0% +huge all right so there's a hidden claim + + + align:start position:0% +huge all right so there's a hidden claim +in there which is that the like least + + align:start position:0% +in there which is that the like least + + + align:start position:0% +in there which is that the like least +SES estimator is equal to the maximum + + align:start position:0% +SES estimator is equal to the maximum + + + align:start position:0% +SES estimator is equal to the maximum +likelihood + + align:start position:0% + + + + align:start position:0% + +estimator why does the maximum lik + + align:start position:0% +estimator why does the maximum lik + + + align:start position:0% +estimator why does the maximum lik +estimator just enter the picture now + + align:start position:0% +estimator just enter the picture now + + + align:start position:0% +estimator just enter the picture now +we've been talking about regression for + + align:start position:0% +we've been talking about regression for + + + align:start position:0% +we've been talking about regression for +the past 18 slides and we've been + + align:start position:0% +the past 18 slides and we've been + + + align:start position:0% +the past 18 slides and we've been +talking about estimators and I just + + align:start position:0% +talking about estimators and I just + + + align:start position:0% +talking about estimators and I just +dumped on you the uh Le squares + + align:start position:0% +dumped on you the uh Le squares + + + align:start position:0% +dumped on you the uh Le squares +estimator but I never really came back + + align:start position:0% +estimator but I never really came back + + + align:start position:0% +estimator but I never really came back +to this thing that we know maybe the + + align:start position:0% +to this thing that we know maybe the + + + align:start position:0% +to this thing that we know maybe the +method of moments or maybe the maximum + + align:start position:0% +method of moments or maybe the maximum + + + align:start position:0% +method of moments or maybe the maximum +likelihood estimator it turns out that + + align:start position:0% +likelihood estimator it turns out that + + + align:start position:0% +likelihood estimator it turns out that +those two things are the same but if I + + align:start position:0% +those two things are the same but if I + + + align:start position:0% +those two things are the same but if I +want to talk about a maximum likelihood + + align:start position:0% +want to talk about a maximum likelihood + + + align:start position:0% +want to talk about a maximum likelihood +estimator I need to have a likelihood + + align:start position:0% +estimator I need to have a likelihood + + + align:start position:0% +estimator I need to have a likelihood +and in particular I need to have a + + align:start position:0% +and in particular I need to have a + + + align:start position:0% +and in particular I need to have a +density and so if I want a density I + + align:start position:0% +density and so if I want a density I + + + align:start position:0% +density and so if I want a density I +have to make those assumptions such + + align:start position:0% +have to make those assumptions such + + + align:start position:0% +have to make those assumptions such +as the epsilons have this gaan + + align:start position:0% +as the epsilons have this gaan + + + align:start position:0% +as the epsilons have this gaan +distribution so why is this the maximum + + align:start position:0% +distribution so why is this the maximum + + + align:start position:0% +distribution so why is this the maximum +likelihood estimator well remember Y is + + align:start position:0% +likelihood estimator well remember Y is + + + align:start position:0% +likelihood estimator well remember Y is +X transpose beta plus Epsilon so I + + align:start position:0% +X transpose beta plus Epsilon so I + + + align:start position:0% +X transpose beta plus Epsilon so I +actually have a bunch of data so what + + align:start position:0% + + + + align:start position:0% + +is what is my model here well it's the + + align:start position:0% +is what is my model here well it's the + + + align:start position:0% +is what is my model here well it's the +family of + + align:start position:0% +family of + + + align:start position:0% +family of +Gans on N observations with mean X beta + + align:start position:0% +Gans on N observations with mean X beta + + + align:start position:0% +Gans on N observations with mean X beta +variance Sigma Square + + align:start position:0% + + + + align:start position:0% + +identity and B + + align:start position:0% +identity and B + + + align:start position:0% +identity and B +lives in our + + align:start position:0% +lives in our + + + align:start position:0% +lives in our +P here's my family of distributions + + align:start position:0% +P here's my family of distributions + + + align:start position:0% +P here's my family of distributions +right that's the possible distributions + + align:start position:0% +right that's the possible distributions + + + align:start position:0% +right that's the possible distributions +for + + align:start position:0% +for + + + align:start position:0% +for +y and so in particular I can write the + + align:start position:0% +y and so in particular I can write the + + + align:start position:0% +y and so in particular I can write the +density of + + align:start position:0% + + + + align:start position:0% + +Y well what is it it's something that + + align:start position:0% +Y well what is it it's something that + + + align:start position:0% +Y well what is it it's something that +looks like P of X well P of Y let's say + + align:start position:0% +looks like P of X well P of Y let's say + + + align:start position:0% +looks like P of X well P of Y let's say +is equal to 1/ over so now it's going to + + align:start position:0% +is equal to 1/ over so now it's going to + + + align:start position:0% +is equal to 1/ over so now it's going to +be a little more complicated but it's um + + align:start position:0% +be a little more complicated but it's um + + + align:start position:0% +be a little more complicated but it's um +Sigma + + align:start position:0% +Sigma + + + align:start position:0% +Sigma +s * 2 pi to the P / + + align:start position:0% +s * 2 pi to the P / + + + align:start position:0% +s * 2 pi to the P / + + align:start position:0% + + + align:start position:0% +exponential + + align:start position:0% +exponential + + + align:start position:0% +exponential +minus + + align:start position:0% +minus + + + align:start position:0% +minus +um Norm of Yus X beta + + align:start position:0% +um Norm of Yus X beta + + + align:start position:0% +um Norm of Yus X beta +squar ID 2 Sigma + + align:start position:0% +squar ID 2 Sigma + + + align:start position:0% +squar ID 2 Sigma +squ okay so that's just the multivaried + + align:start position:0% +squ okay so that's just the multivaried + + + align:start position:0% +squ okay so that's just the multivaried +Gan density I just wrote it that's the + + align:start position:0% +Gan density I just wrote it that's the + + + align:start position:0% +Gan density I just wrote it that's the +density of a multivaried gan with mean X + + align:start position:0% +density of a multivaried gan with mean X + + + align:start position:0% +density of a multivaried gan with mean X +beta and cence Matrix Sigma Square * the + + align:start position:0% +beta and cence Matrix Sigma Square * the + + + align:start position:0% +beta and cence Matrix Sigma Square * the +identity that's what it + + align:start position:0% +identity that's what it + + + align:start position:0% +identity that's what it +is okay so you don't have to learn this + + align:start position:0% +is okay so you don't have to learn this + + + align:start position:0% +is okay so you don't have to learn this +by heart but uh if you are familiar with + + align:start position:0% +by heart but uh if you are familiar with + + + align:start position:0% +by heart but uh if you are familiar with +the uh case where p is equal to one you + + align:start position:0% +the uh case where p is equal to one you + + + align:start position:0% +the uh case where p is equal to one you +can check that you recover what you're + + align:start position:0% +can check that you recover what you're + + + align:start position:0% +can check that you recover what you're +familiar with and uh and uh and this + + align:start position:0% +familiar with and uh and uh and this + + + align:start position:0% +familiar with and uh and uh and this +sort of makes sense as an extension + + align:start position:0% + + + + align:start position:0% + +so now I can actually + + align:start position:0% + + + + align:start position:0% + +write my log likelihood + + align:start position:0% +write my log likelihood + + + align:start position:0% +write my log likelihood +right how many observations do I + + align:start position:0% + + + + align:start position:0% + +have of this Vector + + align:start position:0% + + + + align:start position:0% + +y do I have n observations of why + + align:start position:0% + + + + align:start position:0% + +I have just one right this oh sorry + + align:start position:0% +I have just one right this oh sorry + + + align:start position:0% +I have just one right this oh sorry +that's sorry I shouldn't have said P + + align:start position:0% +that's sorry I shouldn't have said P + + + align:start position:0% +that's sorry I shouldn't have said P +this is n right everything is in + + align:start position:0% +this is n right everything is in + + + align:start position:0% +this is n right everything is in +dimension n so I have I can think of + + align:start position:0% +dimension n so I have I can think of + + + align:start position:0% +dimension n so I have I can think of +either having n independent observations + + align:start position:0% +either having n independent observations + + + align:start position:0% +either having n independent observations +of each coordinate or I can think of + + align:start position:0% +of each coordinate or I can think of + + + align:start position:0% +of each coordinate or I can think of +having just one observation of the + + align:start position:0% +having just one observation of the + + + align:start position:0% +having just one observation of the +vector y so when I write my log + + align:start position:0% +vector y so when I write my log + + + align:start position:0% +vector y so when I write my log +likelihood it's just the log of the + + align:start position:0% +likelihood it's just the log of the + + + align:start position:0% +likelihood it's just the log of the +density at y + + align:start position:0% + + + + align:start position:0% + +and that's the vector + + align:start position:0% +and that's the vector + + + align:start position:0% +and that's the vector +Y which I can write as - n /2 log Sigma + + align:start position:0% +Y which I can write as - n /2 log Sigma + + + align:start position:0% +Y which I can write as - n /2 log Sigma +2 2 + + align:start position:0% +2 2 + + + align:start position:0% +2 2 +pi minus one 1 over 2 Sigma squ Norm of + + align:start position:0% +pi minus one 1 over 2 Sigma squ Norm of + + + align:start position:0% +pi minus one 1 over 2 Sigma squ Norm of +Yus X beta and that's again my bold face + + align:start position:0% + + + + align:start position:0% + +y okay and what is my maximum likelihood + + align:start position:0% + + + + align:start position:0% + +estimator well this guy does not depend + + align:start position:0% +estimator well this guy does not depend + + + align:start position:0% +estimator well this guy does not depend +on + + align:start position:0% +on + + + align:start position:0% +on +beta and this is just a constant factor + + align:start position:0% +beta and this is just a constant factor + + + align:start position:0% +beta and this is just a constant factor +in front of this guy so it's the same + + align:start position:0% +in front of this guy so it's the same + + + align:start position:0% +in front of this guy so it's the same +thing as just minimizing because I have + + align:start position:0% +thing as just minimizing because I have + + + align:start position:0% +thing as just minimizing because I have +a minus sign overall beta in r + + align:start position:0% + + + + align:start position:0% + +p y - x beta squ and that's my le + + align:start position:0% +p y - x beta squ and that's my le + + + align:start position:0% +p y - x beta squ and that's my le +squares + + align:start position:0% + + + + align:start position:0% + +estimator + + align:start position:0% + + + + align:start position:0% + +okay is there anything that's unclear on + + align:start position:0% +okay is there anything that's unclear on + + + align:start position:0% +okay is there anything that's unclear on +this board any + + align:start position:0% +this board any + + + align:start position:0% +this board any +question right so all I Ed was so I + + align:start position:0% +question right so all I Ed was so I + + + align:start position:0% +question right so all I Ed was so I +wrote my log likelihood which is just + + align:start position:0% +wrote my log likelihood which is just + + + align:start position:0% +wrote my log likelihood which is just +the log of this expression where Y is my + + align:start position:0% +the log of this expression where Y is my + + + align:start position:0% +the log of this expression where Y is my +observation and that's indeed the + + align:start position:0% +observation and that's indeed the + + + align:start position:0% +observation and that's indeed the +observation that I have + + align:start position:0% +observation that I have + + + align:start position:0% +observation that I have +here and that was just some constant + + align:start position:0% +here and that was just some constant + + + align:start position:0% +here and that was just some constant +minus some constant times this quantity + + align:start position:0% +minus some constant times this quantity + + + align:start position:0% +minus some constant times this quantity +that depends on beta so maximizing this + + align:start position:0% +that depends on beta so maximizing this + + + align:start position:0% +that depends on beta so maximizing this +whole thing is the same thing as + + align:start position:0% +whole thing is the same thing as + + + align:start position:0% +whole thing is the same thing as +minimizing only this thing the + + align:start position:0% +minimizing only this thing the + + + align:start position:0% +minimizing only this thing the +minimizers are the same and uh so that + + align:start position:0% +minimizers are the same and uh so that + + + align:start position:0% +minimizers are the same and uh so that +tells me that I actually just have to + + align:start position:0% +tells me that I actually just have to + + + align:start position:0% +tells me that I actually just have to +minimize the square Norm to get my + + align:start position:0% +minimize the square Norm to get my + + + align:start position:0% +minimize the square Norm to get my +maximum likelihood estimator but this + + align:start position:0% +maximum likelihood estimator but this + + + align:start position:0% +maximum likelihood estimator but this +used heavily the fact that I could + + align:start position:0% +used heavily the fact that I could + + + align:start position:0% +used heavily the fact that I could +actually write exactly + + align:start position:0% +actually write exactly + + + align:start position:0% +actually write exactly +what my density + + align:start position:0% +what my density + + + align:start position:0% +what my density +was and uh and + + align:start position:0% +was and uh and + + + align:start position:0% +was and uh and +uh and uh that when I took the log of + + align:start position:0% +uh and uh that when I took the log of + + + align:start position:0% +uh and uh that when I took the log of +this thing I had exactly the square Norm + + align:start position:0% +this thing I had exactly the square Norm + + + align:start position:0% +this thing I had exactly the square Norm +that showed + + align:start position:0% +that showed + + + align:start position:0% +that showed +up if I had a different density if for + + align:start position:0% +up if I had a different density if for + + + align:start position:0% +up if I had a different density if for +example I assumed that my coordinates of + + align:start position:0% +example I assumed that my coordinates of + + + align:start position:0% +example I assumed that my coordinates of +one of epsilons were say IID exponential + + align:start position:0% +one of epsilons were say IID exponential + + + align:start position:0% +one of epsilons were say IID exponential +double exponential random variables + + align:start position:0% +double exponential random variables + + + align:start position:0% +double exponential random variables +right so it's just uh half of an + + align:start position:0% +right so it's just uh half of an + + + align:start position:0% +right so it's just uh half of an +exponential on the pluses half of an + + align:start position:0% +exponential on the pluses half of an + + + align:start position:0% +exponential on the pluses half of an +exponential on the negatives so if I + + align:start position:0% +exponential on the negatives so if I + + + align:start position:0% +exponential on the negatives so if I +said that then this would not have the + + align:start position:0% +said that then this would not have the + + + align:start position:0% +said that then this would not have the +square Norm that shows up this is really + + align:start position:0% +square Norm that shows up this is really + + + align:start position:0% +square Norm that shows up this is really +idiosyncratic to gaussians if I had + + align:start position:0% +idiosyncratic to gaussians if I had + + + align:start position:0% +idiosyncratic to gaussians if I had +something else I would have maybe a + + align:start position:0% +something else I would have maybe a + + + align:start position:0% +something else I would have maybe a +different Norm here or something + + align:start position:0% +different Norm here or something + + + align:start position:0% +different Norm here or something +different that measures the difference + + align:start position:0% +different that measures the difference + + + align:start position:0% +different that measures the difference +between Y and and X beta and that's how + + align:start position:0% +between Y and and X beta and that's how + + + align:start position:0% +between Y and and X beta and that's how +you come up with other maximum + + align:start position:0% +you come up with other maximum + + + align:start position:0% +you come up with other maximum +likelihood estimators that leads to + + align:start position:0% +likelihood estimators that leads to + + + align:start position:0% +likelihood estimators that leads to +other estimators that are not the least + + align:start position:0% +other estimators that are not the least + + + align:start position:0% +other estimators that are not the least +squares maybe the least absolute + + align:start position:0% +squares maybe the least absolute + + + align:start position:0% +squares maybe the least absolute +deviation for example or you know this + + align:start position:0% +deviation for example or you know this + + + align:start position:0% +deviation for example or you know this +fourth moment for example that you + + align:start position:0% +fourth moment for example that you + + + align:start position:0% +fourth moment for example that you +suggested last time so I can come up + + align:start position:0% +suggested last time so I can come up + + + align:start position:0% +suggested last time so I can come up +with a bunch of different things and + + align:start position:0% +with a bunch of different things and + + + align:start position:0% +with a bunch of different things and +they might be maybe I can come up from + + align:start position:0% +they might be maybe I can come up from + + + align:start position:0% +they might be maybe I can come up from +them from the same perspective that I + + align:start position:0% +them from the same perspective that I + + + align:start position:0% +them from the same perspective that I +came from the Le squares estimator I + + align:start position:0% +came from the Le squares estimator I + + + align:start position:0% +came from the Le squares estimator I +said let's just do something smart and + + align:start position:0% +said let's just do something smart and + + + align:start position:0% +said let's just do something smart and +check then that it's indeed the maximum + + align:start position:0% +check then that it's indeed the maximum + + + align:start position:0% +check then that it's indeed the maximum +likelihood + + align:start position:0% +likelihood + + + align:start position:0% +likelihood +estimator or I could just start with a + + align:start position:0% +estimator or I could just start with a + + + align:start position:0% +estimator or I could just start with a +modeling on and check then what happens + + align:start position:0% +modeling on and check then what happens + + + align:start position:0% +modeling on and check then what happens +uh what was the implicit assumption that + + align:start position:0% +uh what was the implicit assumption that + + + align:start position:0% +uh what was the implicit assumption that +I put on my noise or I could start with + + align:start position:0% +I put on my noise or I could start with + + + align:start position:0% +I put on my noise or I could start with +the Assumption of the noise compute the + + align:start position:0% +the Assumption of the noise compute the + + + align:start position:0% +the Assumption of the noise compute the +maximum likelihood estimator and see + + align:start position:0% +maximum likelihood estimator and see + + + align:start position:0% +maximum likelihood estimator and see +what it turns + + align:start position:0% +what it turns + + + align:start position:0% +what it turns +into all right so that was the first + + align:start position:0% +into all right so that was the first + + + align:start position:0% +into all right so that was the first +thing I'm just I've just uh proved to + + align:start position:0% +thing I'm just I've just uh proved to + + + align:start position:0% +thing I'm just I've just uh proved to +you the first line and from there you + + align:start position:0% +you the first line and from there you + + + align:start position:0% +you the first line and from there you +can get what you want right so all the + + align:start position:0% +can get what you want right so all the + + + align:start position:0% +can get what you want right so all the +other lines are going to follow so what + + align:start position:0% +other lines are going to follow so what + + + align:start position:0% +other lines are going to follow so what +is beta head so for example let's look + + align:start position:0% +is beta head so for example let's look + + + align:start position:0% +is beta head so for example let's look +at + + align:start position:0% +at + + + align:start position:0% +at +the let's look at the second line the + + align:start position:0% +the let's look at the second line the + + + align:start position:0% +the let's look at the second line the +quadratic + + align:start position:0% + + + + align:start position:0% + +risk beta hat minus beta from this + + align:start position:0% +risk beta hat minus beta from this + + + align:start position:0% +risk beta hat minus beta from this +formula has a distribution which is n n + + align:start position:0% +formula has a distribution which is n n + + + align:start position:0% +formula has a distribution which is n n +zero and then I have X transpose X iners + + align:start position:0% + + + + align:start position:0% + +right sorry the dimension of + + align:start position:0% + + + + align:start position:0% + +whataa only a p dimensional oh yeah + + align:start position:0% +whataa only a p dimensional oh yeah + + + align:start position:0% +whataa only a p dimensional oh yeah +you're right you're right you're right + + align:start position:0% +you're right you're right you're right + + + align:start position:0% +you're right you're right you're right +that was all P dimensional + + align:start position:0% + + + + align:start position:0% + +there yeah because right so if I if B + + align:start position:0% +there yeah because right so if I if B + + + align:start position:0% +there yeah because right so if I if B +here the Matrix that my actually + + align:start position:0% +here the Matrix that my actually + + + align:start position:0% +here the Matrix that my actually +applying has Dimension P * n so even if + + align:start position:0% +applying has Dimension P * n so even if + + + align:start position:0% +applying has Dimension P * n so even if +Epsilon was an N dimensional Gan Vector + + align:start position:0% +Epsilon was an N dimensional Gan Vector + + + align:start position:0% +Epsilon was an N dimensional Gan Vector +then B * Epsilon is a p dimensional Gan + + align:start position:0% +then B * Epsilon is a p dimensional Gan + + + align:start position:0% +then B * Epsilon is a p dimensional Gan +Vector now all right so that's how I + + align:start position:0% +Vector now all right so that's how I + + + align:start position:0% +Vector now all right so that's how I +switch from P to n from n2p thank you + + align:start position:0% +switch from P to n from n2p thank you + + + align:start position:0% +switch from P to n from n2p thank you +all right so you're right this is beta + + align:start position:0% +all right so you're right this is beta + + + align:start position:0% +all right so you're right this is beta +hats uh minus beta is this guy and so in + + align:start position:0% +hats uh minus beta is this guy and so in + + + align:start position:0% +hats uh minus beta is this guy and so in +particular if I look at the + + align:start position:0% +particular if I look at the + + + align:start position:0% +particular if I look at the +expectation of the norm of beta hats + + align:start position:0% +expectation of the norm of beta hats + + + align:start position:0% +expectation of the norm of beta hats +beta + + align:start position:0% + + + + align:start position:0% + +s what is it it's the + + align:start position:0% +s what is it it's the + + + align:start position:0% +s what is it it's the +expectation of the norm of some uh uh + + align:start position:0% +expectation of the norm of some uh uh + + + align:start position:0% +expectation of the norm of some uh uh +gussian Vector oh sorry of the norm yeah + + align:start position:0% +gussian Vector oh sorry of the norm yeah + + + align:start position:0% +gussian Vector oh sorry of the norm yeah +of the norm of some gussian vector and + + align:start position:0% +of the norm of some gussian vector and + + + align:start position:0% +of the norm of some gussian vector and +so it turns out so maybe we can don't + + align:start position:0% +so it turns out so maybe we can don't + + + align:start position:0% +so it turns out so maybe we can don't +have well okay that's just also a + + align:start position:0% +have well okay that's just also a + + + align:start position:0% +have well okay that's just also a +property of a of a gan Vector right so + + align:start position:0% +property of a of a gan Vector right so + + + align:start position:0% +property of a of a gan Vector right so +if Epsilon is n0 Sigma then the + + align:start position:0% +if Epsilon is n0 Sigma then the + + + align:start position:0% +if Epsilon is n0 Sigma then the +norm the expectation + + align:start position:0% +norm the expectation + + + align:start position:0% +norm the expectation +of the norm of Epsilon s is just the + + align:start position:0% +of the norm of Epsilon s is just the + + + align:start position:0% +of the norm of Epsilon s is just the +trace of + + align:start position:0% + + + + align:start position:0% + +Sigma actually we can probably check + + align:start position:0% +Sigma actually we can probably check + + + align:start position:0% +Sigma actually we can probably check +this uh by saying that this is the sum + + align:start position:0% +this uh by saying that this is the sum + + + align:start position:0% +this uh by saying that this is the sum +from Jal 1 to P of the expectation of + + align:start position:0% +from Jal 1 to P of the expectation of + + + align:start position:0% +from Jal 1 to P of the expectation of +beta J minus Beta had J minus beta j + + align:start position:0% + + + + align:start position:0% + +s since beta j s is the expectation beta + + align:start position:0% +s since beta j s is the expectation beta + + + align:start position:0% +s since beta j s is the expectation beta +G is the expectation of beta head this + + align:start position:0% +G is the expectation of beta head this + + + align:start position:0% +G is the expectation of beta head this +is actually equal to the sum from J = 1 + + align:start position:0% +is actually equal to the sum from J = 1 + + + align:start position:0% +is actually equal to the sum from J = 1 +to P of the + + align:start position:0% +to P of the + + + align:start position:0% +to P of the +variance of beta hat + + align:start position:0% +variance of beta hat + + + align:start position:0% +variance of beta hat +J right just because this is the + + align:start position:0% +J right just because this is the + + + align:start position:0% +J right just because this is the +expectation of beta + + align:start position:0% +expectation of beta + + + align:start position:0% +expectation of beta +hat and how do I read the variances in a + + align:start position:0% +hat and how do I read the variances in a + + + align:start position:0% +hat and how do I read the variances in a +ciance matrix they're just the diagonal + + align:start position:0% +ciance matrix they're just the diagonal + + + align:start position:0% +ciance matrix they're just the diagonal +elements right so that's really + + align:start position:0% +elements right so that's really + + + align:start position:0% +elements right so that's really +just Sigma + + align:start position:0% +just Sigma + + + align:start position:0% +just Sigma +JJ and so that's really equal to so + + align:start position:0% +JJ and so that's really equal to so + + + align:start position:0% +JJ and so that's really equal to so +that's the sum of the diagonal elements + + align:start position:0% +that's the sum of the diagonal elements + + + align:start position:0% +that's the sum of the diagonal elements +of this Matrix let's call it + + align:start position:0% +of this Matrix let's call it + + + align:start position:0% +of this Matrix let's call it +Sigma so that's equal to the + + align:start position:0% +Sigma so that's equal to the + + + align:start position:0% +Sigma so that's equal to the +trace of + + align:start position:0% +trace of + + + align:start position:0% +trace of +X transpose X + + align:start position:0% +X transpose X + + + align:start position:0% +X transpose X +inverse okay the sum of the trace is the + + align:start position:0% +inverse okay the sum of the trace is the + + + align:start position:0% +inverse okay the sum of the trace is the +sum of the diagonal elements of a + + align:start position:0% + + + + align:start position:0% + +matrix and I still had something else + + align:start position:0% +matrix and I still had something else + + + align:start position:0% +matrix and I still had something else +I'm sorry this is not this was Sigma + + align:start position:0% +I'm sorry this is not this was Sigma + + + align:start position:0% +I'm sorry this is not this was Sigma +squar I forget it all the time so the + + align:start position:0% +squar I forget it all the time so the + + + align:start position:0% +squar I forget it all the time so the +sigma Square comes out + + align:start position:0% +sigma Square comes out + + + align:start position:0% +sigma Square comes out +it's there and so the sigma Square comes + + align:start position:0% +it's there and so the sigma Square comes + + + align:start position:0% +it's there and so the sigma Square comes +out okay because the trace is a linear + + align:start position:0% +out okay because the trace is a linear + + + align:start position:0% +out okay because the trace is a linear +operator If I multiply all the entries + + align:start position:0% +operator If I multiply all the entries + + + align:start position:0% +operator If I multiply all the entries +of my matrix by some the same number + + align:start position:0% +of my matrix by some the same number + + + align:start position:0% +of my matrix by some the same number +then all the diagonal elements are + + align:start position:0% +then all the diagonal elements are + + + align:start position:0% +then all the diagonal elements are +multiplied by the same number so when I + + align:start position:0% +multiplied by the same number so when I + + + align:start position:0% +multiplied by the same number so when I +sum them the sum is multiplied by the + + align:start position:0% +sum them the sum is multiplied by the + + + align:start position:0% +sum them the sum is multiplied by the +same + + align:start position:0% +same + + + align:start position:0% +same +number okay so that's for the quadratic + + align:start position:0% +number okay so that's for the quadratic + + + align:start position:0% +number okay so that's for the quadratic +risk of beta hat and now I need to tell + + align:start position:0% +risk of beta hat and now I need to tell + + + align:start position:0% +risk of beta hat and now I need to tell +you about X beta hat right X beta hat + + align:start position:0% +you about X beta hat right X beta hat + + + align:start position:0% +you about X beta hat right X beta hat +was something that was actually telling + + align:start position:0% +was something that was actually telling + + + align:start position:0% +was something that was actually telling +me + + align:start position:0% +me + + + align:start position:0% +me +that that was the point that I reported + + align:start position:0% +that that was the point that I reported + + + align:start position:0% +that that was the point that I reported +on the red red line that I estimated + + align:start position:0% +on the red red line that I estimated + + + align:start position:0% +on the red red line that I estimated +right that was my X beta hat that was + + align:start position:0% +right that was my X beta hat that was + + + align:start position:0% +right that was my X beta hat that was +myep my um sorry my uh y minus the + + align:start position:0% +myep my um sorry my uh y minus the + + + align:start position:0% +myep my um sorry my uh y minus the +noise now this thing here so remember we + + align:start position:0% +noise now this thing here so remember we + + + align:start position:0% +noise now this thing here so remember we +had this line and I had my observation + + align:start position:0% +had this line and I had my observation + + + align:start position:0% +had this line and I had my observation +and here I'm really trying to measure + + align:start position:0% +and here I'm really trying to measure + + + align:start position:0% +and here I'm really trying to measure +this distance + + align:start position:0% +this distance + + + align:start position:0% +this distance +Square this distance is actually quite + + align:start position:0% +Square this distance is actually quite + + + align:start position:0% +Square this distance is actually quite +important for me because it actually + + align:start position:0% +important for me because it actually + + + align:start position:0% +important for me because it actually +shows up in the p in pagor theorem + + align:start position:0% +shows up in the p in pagor theorem + + + align:start position:0% +shows up in the p in pagor theorem +right and so you can actually try to + + align:start position:0% +right and so you can actually try to + + + align:start position:0% +right and so you can actually try to +estimate this thing so what is the + + align:start position:0% +estimate this thing so what is the + + + align:start position:0% +estimate this thing so what is the +prediction + + align:start position:0% + + + + align:start position:0% + +error so we said we have + + align:start position:0% +error so we said we have + + + align:start position:0% +error so we said we have +y minus X beta hat so that's the norm of + + align:start position:0% +y minus X beta hat so that's the norm of + + + align:start position:0% +y minus X beta hat so that's the norm of +this thing we're trying to compute but + + align:start position:0% +this thing we're trying to compute but + + + align:start position:0% +this thing we're trying to compute but +let's write this for what it is for one + + align:start position:0% +let's write this for what it is for one + + + align:start position:0% +let's write this for what it is for one +second right so we said that beta hat + + align:start position:0% +second right so we said that beta hat + + + align:start position:0% +second right so we said that beta hat +was X transpose X inverse X transpose Y + + align:start position:0% +was X transpose X inverse X transpose Y + + + align:start position:0% +was X transpose X inverse X transpose Y +and we know that Y is X transpose beta + + align:start position:0% +and we know that Y is X transpose beta + + + align:start position:0% +and we know that Y is X transpose beta +plus + + align:start position:0% +plus + + + align:start position:0% +plus +Epsilon so let's write + + align:start position:0% + + + + align:start position:0% + +this x beta plus Epsilon plus + + align:start position:0% + + + + align:start position:0% + +X okay + + align:start position:0% +X okay + + + align:start position:0% +X okay +and uh actually maybe I should not write + + align:start position:0% +and uh actually maybe I should not write + + + align:start position:0% +and uh actually maybe I should not write +let me keep the Y for what it is + + align:start position:0% + + + + align:start position:0% + +now okay so that means that I have + + align:start position:0% +now okay so that means that I have + + + align:start position:0% +now okay so that means that I have +essentially the identity of RN * y minus + + align:start position:0% +essentially the identity of RN * y minus + + + align:start position:0% +essentially the identity of RN * y minus +this Matrix time y so I can Factor y out + + align:start position:0% +this Matrix time y so I can Factor y out + + + align:start position:0% +this Matrix time y so I can Factor y out +and that's the identity of RN minus x x + + align:start position:0% +and that's the identity of RN minus x x + + + align:start position:0% +and that's the identity of RN minus x x +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +X inverse X + + align:start position:0% +X inverse X + + + align:start position:0% +X inverse X +transpose the whole thing time + + align:start position:0% + + + + align:start position:0% + +y we said that this we call this Matrix + + align:start position:0% +y we said that this we call this Matrix + + + align:start position:0% +y we said that this we call this Matrix +P because this was the projection Matrix + + align:start position:0% +P because this was the projection Matrix + + + align:start position:0% +P because this was the projection Matrix +onto the linear span of the + + align:start position:0% +onto the linear span of the + + + align:start position:0% +onto the linear span of the +axis right so that means that if I have + + align:start position:0% +axis right so that means that if I have + + + align:start position:0% +axis right so that means that if I have +I take a point x and I apply P * X I'm + + align:start position:0% +I take a point x and I apply P * X I'm + + + align:start position:0% +I take a point x and I apply P * X I'm +projecting onto the linear span of The + + align:start position:0% +projecting onto the linear span of The + + + align:start position:0% +projecting onto the linear span of The +Columns of + + align:start position:0% +Columns of + + + align:start position:0% +Columns of +X what happens if I do I * + + align:start position:0% +X what happens if I do I * + + + align:start position:0% +X what happens if I do I * +P IUS P * + + align:start position:0% +P IUS P * + + + align:start position:0% +P IUS P * +X it's x minus PX + + align:start position:0% +X it's x minus PX + + + align:start position:0% +X it's x minus PX +right so if I look + + align:start position:0% +right so if I look + + + align:start position:0% +right so if I look +at the point on which so this is the + + align:start position:0% +at the point on which so this is the + + + align:start position:0% +at the point on which so this is the +point on which I I project this is x i + + align:start position:0% +point on which I I project this is x i + + + align:start position:0% +point on which I I project this is x i +project orthogonally to get P * + + align:start position:0% +project orthogonally to get P * + + + align:start position:0% +project orthogonally to get P * +X and so what it means is that this + + align:start position:0% +X and so what it means is that this + + + align:start position:0% +X and so what it means is that this +operator IUS PX is actually giving me + + align:start position:0% +operator IUS PX is actually giving me + + + align:start position:0% +operator IUS PX is actually giving me +this guy this Vector + + align:start position:0% +this guy this Vector + + + align:start position:0% +this guy this Vector +here x minus P * X + + align:start position:0% + + + + align:start position:0% + +let's say this is + + align:start position:0% +let's say this is + + + align:start position:0% +let's say this is +zero this means that this Vector I can + + align:start position:0% +zero this means that this Vector I can + + + align:start position:0% +zero this means that this Vector I can +report it here is this Vector here and + + align:start position:0% +report it here is this Vector here and + + + align:start position:0% +report it here is this Vector here and +that's actually the orthogonal + + align:start position:0% +that's actually the orthogonal + + + align:start position:0% +that's actually the orthogonal +projection of X onto the orthogonal + + align:start position:0% +projection of X onto the orthogonal + + + align:start position:0% +projection of X onto the orthogonal +complement of the span of The Columns of + + align:start position:0% +complement of the span of The Columns of + + + align:start position:0% +complement of the span of The Columns of +X right so if I do + + align:start position:0% +X right so if I do + + + align:start position:0% +X right so if I do +X if I Project X or if I look at x minus + + align:start position:0% +X if I Project X or if I look at x minus + + + align:start position:0% +X if I Project X or if I look at x minus +its projection and basically projecting + + align:start position:0% +its projection and basically projecting + + + align:start position:0% +its projection and basically projecting +onto two orthogonal + + align:start position:0% +onto two orthogonal + + + align:start position:0% +onto two orthogonal +spaces which what I trying to say here + + align:start position:0% +spaces which what I trying to say here + + + align:start position:0% +spaces which what I trying to say here +is that this + + align:start position:0% +is that this + + + align:start position:0% +is that this +here is another projection Matrix P + + align:start position:0% + + + + align:start position:0% + +Prime it's just the projection + + align:start position:0% +Prime it's just the projection + + + align:start position:0% +Prime it's just the projection +Matrix onto the orthagonal + + align:start position:0% + + + + align:start position:0% + +projection + + align:start position:0% +projection + + + align:start position:0% +projection +onto + + align:start position:0% + + + + align:start position:0% + +orthogonal of column span + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +X orthogonal means the set of vectors + + align:start position:0% +X orthogonal means the set of vectors + + + align:start position:0% +X orthogonal means the set of vectors +that's orthogonal to everyone in this in + + align:start position:0% +that's orthogonal to everyone in this in + + + align:start position:0% +that's orthogonal to everyone in this in +this linear + + align:start position:0% + + + + align:start position:0% + +space so now when I'm doing this this is + + align:start position:0% +space so now when I'm doing this this is + + + align:start position:0% +space so now when I'm doing this this is +exactly what I mean in a way this is + + align:start position:0% +exactly what I mean in a way this is + + + align:start position:0% +exactly what I mean in a way this is +sort of illustrating this Pythagoras + + align:start position:0% +sort of illustrating this Pythagoras + + + align:start position:0% +sort of illustrating this Pythagoras +Theorem and so when I want to compute + + align:start position:0% +Theorem and so when I want to compute + + + align:start position:0% +Theorem and so when I want to compute +the norm of this guy the norm squar of + + align:start position:0% +the norm of this guy the norm squar of + + + align:start position:0% +the norm of this guy the norm squar of +this guy I'm really Computing if this is + + align:start position:0% +this guy I'm really Computing if this is + + + align:start position:0% +this guy I'm really Computing if this is +my y now this is PX of Y I'm really + + align:start position:0% +my y now this is PX of Y I'm really + + + align:start position:0% +my y now this is PX of Y I'm really +controlling the norm squar of this thing + + align:start position:0% + + + + align:start position:0% + +okay so if I want to compute the norm + + align:start position:0% +okay so if I want to compute the norm + + + align:start position:0% +okay so if I want to compute the norm +squared + + align:start position:0% + + + + align:start position:0% + +so I'm almost + + align:start position:0% +so I'm almost + + + align:start position:0% +so I'm almost +there so what am I projecting here onto + + align:start position:0% +there so what am I projecting here onto + + + align:start position:0% +there so what am I projecting here onto +the + + align:start position:0% +the + + + align:start position:0% +the +orthogonal projector right so here y now + + align:start position:0% +orthogonal projector right so here y now + + + align:start position:0% +orthogonal projector right so here y now +I know that Y is equal to X beta plus + + align:start position:0% +I know that Y is equal to X beta plus + + + align:start position:0% +I know that Y is equal to X beta plus +Epsilon + + align:start position:0% +Epsilon + + + align:start position:0% +Epsilon +right so when I look at this Matrix P + + align:start position:0% + + + + align:start position:0% + +Prime Time y it's actually P Prime * X + + align:start position:0% +Prime Time y it's actually P Prime * X + + + align:start position:0% +Prime Time y it's actually P Prime * X +beta plus P Prime * + + align:start position:0% + + + + align:start position:0% + +Epsilon what's happening to P Prime Time + + align:start position:0% +Epsilon what's happening to P Prime Time + + + align:start position:0% +Epsilon what's happening to P Prime Time +X + + align:start position:0% +X + + + align:start position:0% +X +beta let's look at this + + align:start position:0% + + + + align:start position:0% + +picture right so we know that P Prime + + align:start position:0% +picture right so we know that P Prime + + + align:start position:0% +picture right so we know that P Prime +takes any point here and projects it + + align:start position:0% +takes any point here and projects it + + + align:start position:0% +takes any point here and projects it +orthogonally on this guy but X beta is + + align:start position:0% +orthogonally on this guy but X beta is + + + align:start position:0% +orthogonally on this guy but X beta is +actually a point that lives + + align:start position:0% +actually a point that lives + + + align:start position:0% +actually a point that lives +here right it's something that's on the + + align:start position:0% +here right it's something that's on the + + + align:start position:0% +here right it's something that's on the +linear span so where do all the points + + align:start position:0% +linear span so where do all the points + + + align:start position:0% +linear span so where do all the points +that are on this line get projected + + align:start position:0% + + + + align:start position:0% + +to the origin to zero right they all get + + align:start position:0% +to the origin to zero right they all get + + + align:start position:0% +to the origin to zero right they all get +projected to zero and that's because I'm + + align:start position:0% +projected to zero and that's because I'm + + + align:start position:0% +projected to zero and that's because I'm +basically projecting something that's on + + align:start position:0% +basically projecting something that's on + + + align:start position:0% +basically projecting something that's on +the column span of X onto its orthogonal + + align:start position:0% +the column span of X onto its orthogonal + + + align:start position:0% +the column span of X onto its orthogonal +so that's always zero that I'm getting + + align:start position:0% + + + + align:start position:0% + +here so when I apply P Prime to Y I'm + + align:start position:0% +here so when I apply P Prime to Y I'm + + + align:start position:0% +here so when I apply P Prime to Y I'm +really just applying P Prime to + + align:start position:0% +really just applying P Prime to + + + align:start position:0% +really just applying P Prime to +Epsilon okay so I know that now this + + align:start position:0% +Epsilon okay so I know that now this + + + align:start position:0% +Epsilon okay so I know that now this +actually is equal to the + + align:start position:0% +actually is equal to the + + + align:start position:0% +actually is equal to the +norm of some + + align:start position:0% +norm of some + + + align:start position:0% +norm of some +multivariate uh gin what is the size of + + align:start position:0% +multivariate uh gin what is the size of + + + align:start position:0% +multivariate uh gin what is the size of +this + + align:start position:0% + + + + align:start position:0% + +gin what is the size of this Matrix well + + align:start position:0% +gin what is the size of this Matrix well + + + align:start position:0% +gin what is the size of this Matrix well +I actually had it there it's i n right + + align:start position:0% +I actually had it there it's i n right + + + align:start position:0% +I actually had it there it's i n right +so it's n dimensional so it's some n + + align:start position:0% +so it's n dimensional so it's some n + + + align:start position:0% +so it's n dimensional so it's some n +dimensional with mean zero and what is + + align:start position:0% +dimensional with mean zero and what is + + + align:start position:0% +dimensional with mean zero and what is +the cience Matrix of P Prime * + + align:start position:0% + + + + align:start position:0% + +Epsilon yeah P Prime P Prime transpose + + align:start position:0% +Epsilon yeah P Prime P Prime transpose + + + align:start position:0% +Epsilon yeah P Prime P Prime transpose +right which we just said P transpose is + + align:start position:0% +right which we just said P transpose is + + + align:start position:0% +right which we just said P transpose is +p Prime transpose is p so that's p^ s + + align:start position:0% +p Prime transpose is p so that's p^ s + + + align:start position:0% +p Prime transpose is p so that's p^ s +and we said that when we project twice + + align:start position:0% +and we said that when we project twice + + + align:start position:0% +and we said that when we project twice +it's as if we projected only once so + + align:start position:0% +it's as if we projected only once so + + + align:start position:0% +it's as if we projected only once so +here the this is n0 p Prime P Prime + + align:start position:0% +here the this is n0 p Prime P Prime + + + align:start position:0% +here the this is n0 p Prime P Prime +transpose that's the formula for the + + align:start position:0% +transpose that's the formula for the + + + align:start position:0% +transpose that's the formula for the +cience + + align:start position:0% +cience + + + align:start position:0% +cience +Matrix but this guy is actually equal to + + align:start position:0% +Matrix but this guy is actually equal to + + + align:start position:0% +Matrix but this guy is actually equal to +P Prime * P Prime which is equal to P + + align:start position:0% +P Prime * P Prime which is equal to P + + + align:start position:0% +P Prime * P Prime which is equal to P +Prime so now what I'm looking for is the + + align:start position:0% +Prime so now what I'm looking for is the + + + align:start position:0% +Prime so now what I'm looking for is the +norm squared of the + + align:start position:0% +norm squared of the + + + align:start position:0% +norm squared of the +trace so that means that this whole + + align:start position:0% +trace so that means that this whole + + + align:start position:0% +trace so that means that this whole +thing here is actually equal to the to + + align:start position:0% +thing here is actually equal to the to + + + align:start position:0% +thing here is actually equal to the to +the trace oh did I forget again an + + align:start position:0% +the trace oh did I forget again an + + + align:start position:0% +the trace oh did I forget again an +Epsilon a sigma Square yeah I forgot it + + align:start position:0% +Epsilon a sigma Square yeah I forgot it + + + align:start position:0% +Epsilon a sigma Square yeah I forgot it +only here which is good news all right + + align:start position:0% +only here which is good news all right + + + align:start position:0% +only here which is good news all right +so I should assume that Sigma square is + + align:start position:0% +so I should assume that Sigma square is + + + align:start position:0% +so I should assume that Sigma square is +equal to one um so Sigma Square here and + + align:start position:0% +equal to one um so Sigma Square here and + + + align:start position:0% +equal to one um so Sigma Square here and +then what I'm left with is Sigma squ + + align:start position:0% +then what I'm left with is Sigma squ + + + align:start position:0% +then what I'm left with is Sigma squ +times the + + align:start position:0% +times the + + + align:start position:0% +times the +trace of P + + align:start position:0% + + + + align:start position:0% + +Prime at some point I mentioned that the + + align:start position:0% +Prime at some point I mentioned that the + + + align:start position:0% +Prime at some point I mentioned that the +a values + + align:start position:0% +a values + + + align:start position:0% +a values +of a projection Matrix were actually + + align:start position:0% +of a projection Matrix were actually + + + align:start position:0% +of a projection Matrix were actually +zero or one the trace is the sum of + + align:start position:0% +zero or one the trace is the sum of + + + align:start position:0% +zero or one the trace is the sum of +Theon values so it means that the trace + + align:start position:0% +Theon values so it means that the trace + + + align:start position:0% +Theon values so it means that the trace +is going to be an integer + + align:start position:0% +is going to be an integer + + + align:start position:0% +is going to be an integer +number is the number of non-zero values + + align:start position:0% +number is the number of non-zero values + + + align:start position:0% +number is the number of non-zero values +and the non-zero values are just the + + align:start position:0% +and the non-zero values are just the + + + align:start position:0% +and the non-zero values are just the +dimension of the space onto which I'm + + align:start position:0% + + + + align:start position:0% + +projecting now I'm projecting + + align:start position:0% +projecting now I'm projecting + + + align:start position:0% +projecting now I'm projecting +from something of Dimension n onto the + + align:start position:0% +from something of Dimension n onto the + + + align:start position:0% +from something of Dimension n onto the +orthogonal of a space of Dimension P + + align:start position:0% +orthogonal of a space of Dimension P + + + align:start position:0% +orthogonal of a space of Dimension P +what is the dimension of the orthogonal + + align:start position:0% +what is the dimension of the orthogonal + + + align:start position:0% +what is the dimension of the orthogonal +of a space of Dimension P when thought + + align:start position:0% +of a space of Dimension P when thought + + + align:start position:0% +of a space of Dimension P when thought +of a space in dimension n + + align:start position:0% +of a space in dimension n + + + align:start position:0% +of a space in dimension n +n minus P right that's the soal rank + + align:start position:0% +n minus P right that's the soal rank + + + align:start position:0% +n minus P right that's the soal rank +theorem I guess it has name and so + + align:start position:0% +theorem I guess it has name and so + + + align:start position:0% +theorem I guess it has name and so +that's how I get this n minus P here + + align:start position:0% +that's how I get this n minus P here + + + align:start position:0% +that's how I get this n minus P here +this is really just equal to n minus + + align:start position:0% +this is really just equal to n minus + + + align:start position:0% +this is really just equal to n minus +P + + align:start position:0% +P + + + align:start position:0% +P +yeah expectation the whole thing yes + + align:start position:0% +yeah expectation the whole thing yes + + + align:start position:0% +yeah expectation the whole thing yes +you're right so that's actually the + + align:start position:0% + + + + align:start position:0% + +expectation of this thing that's equal + + align:start position:0% +expectation of this thing that's equal + + + align:start position:0% +expectation of this thing that's equal +to that + + align:start position:0% +to that + + + align:start position:0% +to that +absolutely but I actually have much + + align:start position:0% +absolutely but I actually have much + + + align:start position:0% +absolutely but I actually have much +better right I know that the norm that + + align:start position:0% +better right I know that the norm that + + + align:start position:0% +better right I know that the norm that +I'm looking at I know it's going to be + + align:start position:0% +I'm looking at I know it's going to be + + + align:start position:0% +I'm looking at I know it's going to be +this thing what is it going to be the + + align:start position:0% +this thing what is it going to be the + + + align:start position:0% +this thing what is it going to be the +distribution of this + + align:start position:0% + + + + align:start position:0% + +guy Norm square of a + + align:start position:0% +guy Norm square of a + + + align:start position:0% +guy Norm square of a +gan K Square so there's going to be some + + align:start position:0% +gan K Square so there's going to be some + + + align:start position:0% +gan K Square so there's going to be some +K square that shows up and the number of + + align:start position:0% +K square that shows up and the number of + + + align:start position:0% +K square that shows up and the number of +degrees of freedom is actually going to + + align:start position:0% +degrees of freedom is actually going to + + + align:start position:0% +degrees of freedom is actually going to +be also in minus p and maybe it's + + align:start position:0% +be also in minus p and maybe it's + + + align:start position:0% +be also in minus p and maybe it's +actually + + align:start position:0% +actually + + + align:start position:0% +actually +somewhere uh yeah right + + align:start position:0% +somewhere uh yeah right + + + align:start position:0% +somewhere uh yeah right +here n minus P * Sigma hat squ over + + align:start position:0% +here n minus P * Sigma hat squ over + + + align:start position:0% +here n minus P * Sigma hat squ over +Sigma s this is my Sigma hat squ If I + + align:start position:0% +Sigma s this is my Sigma hat squ If I + + + align:start position:0% +Sigma s this is my Sigma hat squ If I +multiply minus P I'm left only with this + + align:start position:0% +multiply minus P I'm left only with this + + + align:start position:0% +multiply minus P I'm left only with this +thing and so that means that I get Sigma + + align:start position:0% +thing and so that means that I get Sigma + + + align:start position:0% +thing and so that means that I get Sigma +Square times because I always forget my + + align:start position:0% +Square times because I always forget my + + + align:start position:0% +Square times because I always forget my +Sigma Square I get Sigma Square times + + align:start position:0% +Sigma Square I get Sigma Square times + + + align:start position:0% +Sigma Square I get Sigma Square times +this thing it turns out that the square + + align:start position:0% +this thing it turns out that the square + + + align:start position:0% +this thing it turns out that the square +Norm of this guy is actually exactly a k + + align:start position:0% +Norm of this guy is actually exactly a k + + + align:start position:0% +Norm of this guy is actually exactly a k +square with n minus B degrees of + + align:start position:0% + + + + align:start position:0% + +freom okay + + align:start position:0% +freom okay + + + align:start position:0% +freom okay +so in particular right so we know that + + align:start position:0% +so in particular right so we know that + + + align:start position:0% +so in particular right so we know that +the expectation of this thing is equal + + align:start position:0% +the expectation of this thing is equal + + + align:start position:0% +the expectation of this thing is equal +to Sigma Square * n minus P so if I + + align:start position:0% +to Sigma Square * n minus P so if I + + + align:start position:0% +to Sigma Square * n minus P so if I +divide both sides by n minus P I'm going + + align:start position:0% +divide both sides by n minus P I'm going + + + align:start position:0% +divide both sides by n minus P I'm going +to have that something whose expectation + + align:start position:0% +to have that something whose expectation + + + align:start position:0% +to have that something whose expectation +is Sigma square and this something I can + + align:start position:0% +is Sigma square and this something I can + + + align:start position:0% +is Sigma square and this something I can +actually compute right it depends on Y + + align:start position:0% +actually compute right it depends on Y + + + align:start position:0% +actually compute right it depends on Y +and X that I know and beta hat that I've + + align:start position:0% +and X that I know and beta hat that I've + + + align:start position:0% +and X that I know and beta hat that I've +just estimated I know what n is and PR + + align:start position:0% +just estimated I know what n is and PR + + + align:start position:0% +just estimated I know what n is and PR +are the dimensions of my Matrix X so I'm + + align:start position:0% +are the dimensions of my Matrix X so I'm + + + align:start position:0% +are the dimensions of my Matrix X so I'm +actually given an estimator whose + + align:start position:0% +actually given an estimator whose + + + align:start position:0% +actually given an estimator whose +expectation is Sigma + + align:start position:0% +expectation is Sigma + + + align:start position:0% +expectation is Sigma +square and so now I'm I actually have an + + align:start position:0% +square and so now I'm I actually have an + + + align:start position:0% +square and so now I'm I actually have an +unbiased estimator of Sigma Square + + align:start position:0% +unbiased estimator of Sigma Square + + + align:start position:0% +unbiased estimator of Sigma Square +that's this guy right here and it's + + align:start position:0% +that's this guy right here and it's + + + align:start position:0% +that's this guy right here and it's +actually super useful all right that's + + align:start position:0% +actually super useful all right that's + + + align:start position:0% +actually super useful all right that's +something it's basically so those are + + align:start position:0% +something it's basically so those are + + + align:start position:0% +something it's basically so those are +called the the is the normalized sum of + + align:start position:0% +called the the is the normalized sum of + + + align:start position:0% +called the the is the normalized sum of +square residuals those are called the + + align:start position:0% +square residuals those are called the + + + align:start position:0% +square residuals those are called the +residuals right those are whatever is + + align:start position:0% +residuals right those are whatever is + + + align:start position:0% +residuals right those are whatever is +residual when I project my points onto + + align:start position:0% +residual when I project my points onto + + + align:start position:0% +residual when I project my points onto +the line that I've + + align:start position:0% +the line that I've + + + align:start position:0% +the line that I've +estimated and so in a way those guys if + + align:start position:0% +estimated and so in a way those guys if + + + align:start position:0% +estimated and so in a way those guys if +you go back to this + + align:start position:0% +you go back to this + + + align:start position:0% +you go back to this +picture this was y i and this was x x I + + align:start position:0% +picture this was y i and this was x x I + + + align:start position:0% +picture this was y i and this was x x I +transpose beta hat right so if beta hat + + align:start position:0% +transpose beta hat right so if beta hat + + + align:start position:0% +transpose beta hat right so if beta hat +is close to Beta the difference between + + align:start position:0% +is close to Beta the difference between + + + align:start position:0% +is close to Beta the difference between +Yi and XI transpose beta should be close + + align:start position:0% +Yi and XI transpose beta should be close + + + align:start position:0% +Yi and XI transpose beta should be close +to my Epsilon I + + align:start position:0% +to my Epsilon I + + + align:start position:0% +to my Epsilon I +right it's some sort of Epsilon I + + align:start position:0% + + + + align:start position:0% + +hat + + align:start position:0% +hat + + + align:start position:0% +hat +agreed and so that means that if I if I + + align:start position:0% +agreed and so that means that if I if I + + + align:start position:0% +agreed and so that means that if I if I +think of those as being Epsilon I hat + + align:start position:0% +think of those as being Epsilon I hat + + + align:start position:0% +think of those as being Epsilon I hat +they should have they should be close to + + align:start position:0% +they should have they should be close to + + + align:start position:0% +they should have they should be close to +Epsilon I and so their Norm should be + + align:start position:0% +Epsilon I and so their Norm should be + + + align:start position:0% +Epsilon I and so their Norm should be +giving me something that looks like + + align:start position:0% +giving me something that looks like + + + align:start position:0% +giving me something that looks like +Sigma squ and so it's that's why it + + align:start position:0% +Sigma squ and so it's that's why it + + + align:start position:0% +Sigma squ and so it's that's why it +actually makes sense it's just magical + + align:start position:0% +actually makes sense it's just magical + + + align:start position:0% +actually makes sense it's just magical +that everything works out together + + align:start position:0% +that everything works out together + + + align:start position:0% +that everything works out together +because I'm not projecting on the right + + align:start position:0% +because I'm not projecting on the right + + + align:start position:0% +because I'm not projecting on the right +line I'm actually projecting on the + + align:start position:0% +line I'm actually projecting on the + + + align:start position:0% +line I'm actually projecting on the +wrong line but in the end things + + align:start position:0% +wrong line but in the end things + + + align:start position:0% +wrong line but in the end things +actually work out pretty well + + align:start position:0% +actually work out pretty well + + + align:start position:0% +actually work out pretty well +okay there's one thing so here the + + align:start position:0% +okay there's one thing so here the + + + align:start position:0% +okay there's one thing so here the +theorem is that this thing not only has + + align:start position:0% +theorem is that this thing not only has + + + align:start position:0% +theorem is that this thing not only has +the right expectation but also has a k + + align:start position:0% +the right expectation but also has a k + + + align:start position:0% +the right expectation but also has a k +Square distribution that's what we just + + align:start position:0% +Square distribution that's what we just + + + align:start position:0% +Square distribution that's what we just +discussed so here I'm just telling you + + align:start position:0% +discussed so here I'm just telling you + + + align:start position:0% +discussed so here I'm just telling you +this but it's not too hard to believe + + align:start position:0% +this but it's not too hard to believe + + + align:start position:0% +this but it's not too hard to believe +because it's actually the norm of some + + align:start position:0% +because it's actually the norm of some + + + align:start position:0% +because it's actually the norm of some +Vector you could make this obvious but + + align:start position:0% +Vector you could make this obvious but + + + align:start position:0% +Vector you could make this obvious but +again I didn't want to bring in too much + + align:start position:0% +again I didn't want to bring in too much + + + align:start position:0% +again I didn't want to bring in too much +linear algebra so to prove this you + + align:start position:0% +linear algebra so to prove this you + + + align:start position:0% +linear algebra so to prove this you +actually have to diagonalize uh The + + align:start position:0% +actually have to diagonalize uh The + + + align:start position:0% +actually have to diagonalize uh The +Matrix P so you have to invoke uh the uh + + align:start position:0% +Matrix P so you have to invoke uh the uh + + + align:start position:0% +Matrix P so you have to invoke uh the uh +uh igen value decomposition and the fact + + align:start position:0% +uh igen value decomposition and the fact + + + align:start position:0% +uh igen value decomposition and the fact +that the norm is variant by rotation so + + align:start position:0% +that the norm is variant by rotation so + + + align:start position:0% +that the norm is variant by rotation so +for those who are familiar with what I + + align:start position:0% +for those who are familiar with what I + + + align:start position:0% +for those who are familiar with what I +can do is just look at the decomposition + + align:start position:0% +can do is just look at the decomposition + + + align:start position:0% +can do is just look at the decomposition +of P Prime into u d u transpose where + + align:start position:0% +of P Prime into u d u transpose where + + + align:start position:0% +of P Prime into u d u transpose where +this is an orthogonal Matrix and this is + + align:start position:0% +this is an orthogonal Matrix and this is + + + align:start position:0% +this is an orthogonal Matrix and this is +a diagonal matrix of igen values and + + align:start position:0% +a diagonal matrix of igen values and + + + align:start position:0% +a diagonal matrix of igen values and +when I look at the norm squar of this + + align:start position:0% +when I look at the norm squar of this + + + align:start position:0% +when I look at the norm squar of this +thing I mean I have basically the norm + + align:start position:0% +thing I mean I have basically the norm + + + align:start position:0% +thing I mean I have basically the norm +square of P Prime Time some + + align:start position:0% +square of P Prime Time some + + + align:start position:0% +square of P Prime Time some +Epsilon it's the norm of u d u transpose + + align:start position:0% +Epsilon it's the norm of u d u transpose + + + align:start position:0% +Epsilon it's the norm of u d u transpose +Epsilon s + + align:start position:0% +Epsilon s + + + align:start position:0% +Epsilon s +the norm of a rotation of a vector is + + align:start position:0% +the norm of a rotation of a vector is + + + align:start position:0% +the norm of a rotation of a vector is +the same as the norm of the vector so + + align:start position:0% +the same as the norm of the vector so + + + align:start position:0% +the same as the norm of the vector so +this guy goes away this is not + + align:start position:0% +this guy goes away this is not + + + align:start position:0% +this guy goes away this is not +actually I mean you don't have to care + + align:start position:0% +actually I mean you don't have to care + + + align:start position:0% +actually I mean you don't have to care +about this if you don't understand what + + align:start position:0% +about this if you don't understand what + + + align:start position:0% +about this if you don't understand what +I'm saying so don't freak out this + + align:start position:0% +I'm saying so don't freak out this + + + align:start position:0% +I'm saying so don't freak out this +really for those who follow what is the + + align:start position:0% +really for those who follow what is the + + + align:start position:0% +really for those who follow what is the +distribution of U transpose + + align:start position:0% + + + + align:start position:0% + +Epsilon I take a gaussian + + align:start position:0% +Epsilon I take a gaussian + + + align:start position:0% +Epsilon I take a gaussian +vector that has conance Matrix Sigma + + align:start position:0% +vector that has conance Matrix Sigma + + + align:start position:0% +vector that has conance Matrix Sigma +Square The Entity and I basically rotate + + align:start position:0% +Square The Entity and I basically rotate + + + align:start position:0% +Square The Entity and I basically rotate +it what is its distribution + + align:start position:0% + + + + align:start position:0% + +yeah it's the same it's completely + + align:start position:0% +yeah it's the same it's completely + + + align:start position:0% +yeah it's the same it's completely +invariant right because the Gan think of + + align:start position:0% +invariant right because the Gan think of + + + align:start position:0% +invariant right because the Gan think of +all directions as being the same so it + + align:start position:0% +all directions as being the same so it + + + align:start position:0% +all directions as being the same so it +doesn't really matter if I take a gan or + + align:start position:0% +doesn't really matter if I take a gan or + + + align:start position:0% +doesn't really matter if I take a gan or +rotated Gan so this is also a gan so I'm + + align:start position:0% +rotated Gan so this is also a gan so I'm + + + align:start position:0% +rotated Gan so this is also a gan so I'm +going to call it Epsilon Prime and I'm + + align:start position:0% +going to call it Epsilon Prime and I'm + + + align:start position:0% +going to call it Epsilon Prime and I'm +left with just the norm of Epsilon + + align:start position:0% +left with just the norm of Epsilon + + + align:start position:0% +left with just the norm of Epsilon +primes so this is the sum of the + + align:start position:0% +primes so this is the sum of the + + + align:start position:0% +primes so this is the sum of the +DJ's uh + + align:start position:0% + + + + align:start position:0% + +squared time Epsilon j^ s + + align:start position:0% +squared time Epsilon j^ s + + + align:start position:0% +squared time Epsilon j^ s +right and we just said that the igen + + align:start position:0% +right and we just said that the igen + + + align:start position:0% +right and we just said that the igen +values of P are either zero or one + + align:start position:0% +values of P are either zero or one + + + align:start position:0% +values of P are either zero or one +because it's a projector and so here I'm + + align:start position:0% +because it's a projector and so here I'm + + + align:start position:0% +because it's a projector and so here I'm +going to get only zeros and ones so I'm + + align:start position:0% +going to get only zeros and ones so I'm + + + align:start position:0% +going to get only zeros and ones so I'm +really just + + align:start position:0% +really just + + + align:start position:0% +really just +summing a certain number of uh Epson I + + align:start position:0% +summing a certain number of uh Epson I + + + align:start position:0% +summing a certain number of uh Epson I +squ so square of of standard + + align:start position:0% +squ so square of of standard + + + align:start position:0% +squ so square of of standard +Gans uh sorry with a sigma Square + + align:start position:0% +Gans uh sorry with a sigma Square + + + align:start position:0% +Gans uh sorry with a sigma Square +somewhere and uh and uh basically how + + align:start position:0% +somewhere and uh and uh basically how + + + align:start position:0% +somewhere and uh and uh basically how +many do am I summing well the N minus P + + align:start position:0% +many do am I summing well the N minus P + + + align:start position:0% +many do am I summing well the N minus P +the the number of non-zero Val values of + + align:start position:0% +the the number of non-zero Val values of + + + align:start position:0% +the the number of non-zero Val values of +P Prime so that's how it shows up okay + + align:start position:0% +P Prime so that's how it shows up okay + + + align:start position:0% +P Prime so that's how it shows up okay +this when you see this what's theorem + + align:start position:0% +this when you see this what's theorem + + + align:start position:0% +this when you see this what's theorem +what theorem am I using + + align:start position:0% +what theorem am I using + + + align:start position:0% +what theorem am I using +here cence theorem this is this magic + + align:start position:0% +here cence theorem this is this magic + + + align:start position:0% +here cence theorem this is this magic +book I'm actually going to dump + + align:start position:0% +book I'm actually going to dump + + + align:start position:0% +book I'm actually going to dump +everything that I'm not going to prove + + align:start position:0% +everything that I'm not going to prove + + + align:start position:0% +everything that I'm not going to prove +to you and say well this is actually + + align:start position:0% +to you and say well this is actually + + + align:start position:0% +to you and say well this is actually +cence no cockr theorem is really just + + align:start position:0% +cence no cockr theorem is really just + + + align:start position:0% +cence no cockr theorem is really just +telling me something about orthogonality + + align:start position:0% +telling me something about orthogonality + + + align:start position:0% +telling me something about orthogonality +of things and therefore independence of + + align:start position:0% +of things and therefore independence of + + + align:start position:0% +of things and therefore independence of +things and cockrun Theorem was something + + align:start position:0% +things and cockrun Theorem was something + + + align:start position:0% +things and cockrun Theorem was something +that I used when I wanted to use what + + align:start position:0% +that I used when I wanted to use what + + + align:start position:0% +that I used when I wanted to use what +that's something I used just one slide + + align:start position:0% +that's something I used just one slide + + + align:start position:0% +that's something I used just one slide +before + + align:start position:0% + + + + align:start position:0% + +student T Test right I use car theem to + + align:start position:0% +student T Test right I use car theem to + + + align:start position:0% +student T Test right I use car theem to +see that the numerator and the + + align:start position:0% +see that the numerator and the + + + align:start position:0% +see that the numerator and the +denominator of the student statistic + + align:start position:0% +denominator of the student statistic + + + align:start position:0% +denominator of the student statistic +were independent of each other and this + + align:start position:0% +were independent of each other and this + + + align:start position:0% +were independent of each other and this +is exactly what I'm going to do + + align:start position:0% +is exactly what I'm going to do + + + align:start position:0% +is exactly what I'm going to do +here I have I'm going to actually write + + align:start position:0% +here I have I'm going to actually write + + + align:start position:0% +here I have I'm going to actually write +a test to test maybe if the beta Gs are + + align:start position:0% +a test to test maybe if the beta Gs are + + + align:start position:0% +a test to test maybe if the beta Gs are +equal to zero I'm going to + + align:start position:0% +equal to zero I'm going to + + + align:start position:0% +equal to zero I'm going to +form a numerator which is beta hat minus + + align:start position:0% +form a numerator which is beta hat minus + + + align:start position:0% +form a numerator which is beta hat minus +beta this is normal we know that beta + + align:start position:0% +beta this is normal we know that beta + + + align:start position:0% +beta this is normal we know that beta +hat is has a gaon distribution I'm going + + align:start position:0% +hat is has a gaon distribution I'm going + + + align:start position:0% +hat is has a gaon distribution I'm going +to standardize by something that makes + + align:start position:0% +to standardize by something that makes + + + align:start position:0% +to standardize by something that makes +sense to me and I'm not going to go into + + align:start position:0% +sense to me and I'm not going to go into + + + align:start position:0% +sense to me and I'm not going to go into +details because we're out of time but + + align:start position:0% +details because we're out of time but + + + align:start position:0% +details because we're out of time but +there's the sigma hat that shows up and + + align:start position:0% +there's the sigma hat that shows up and + + + align:start position:0% +there's the sigma hat that shows up and +then there's a gamma J which takes into + + align:start position:0% +then there's a gamma J which takes into + + + align:start position:0% +then there's a gamma J which takes into +account the fact that my x's right if I + + align:start position:0% +account the fact that my x's right if I + + + align:start position:0% +account the fact that my x's right if I +look at the distribution of beta which + + align:start position:0% +look at the distribution of beta which + + + align:start position:0% +look at the distribution of beta which +is gone I + + align:start position:0% +is gone I + + + align:start position:0% +is gone I +think yeah beta is gone uh oh yeah + + align:start position:0% +think yeah beta is gone uh oh yeah + + + align:start position:0% +think yeah beta is gone uh oh yeah +that's where he where that's where the + + align:start position:0% +that's where he where that's where the + + + align:start position:0% +that's where he where that's where the +cence Matrix depends on this Matrix X + + align:start position:0% +cence Matrix depends on this Matrix X + + + align:start position:0% +cence Matrix depends on this Matrix X +transpose X so this will show up in the + + align:start position:0% +transpose X so this will show up in the + + + align:start position:0% +transpose X so this will show up in the +variance right in particular diagonal + + align:start position:0% +variance right in particular diagonal + + + align:start position:0% +variance right in particular diagonal +elements are going to play a role here + + align:start position:0% +elements are going to play a role here + + + align:start position:0% +elements are going to play a role here +and so that's what my gamas are the + + align:start position:0% +and so that's what my gamas are the + + + align:start position:0% +and so that's what my gamas are the +gamas is G diagonal element of this + + align:start position:0% +gamas is G diagonal element of this + + + align:start position:0% +gamas is G diagonal element of this +Matrix so we'll resume that on uh on + + align:start position:0% +Matrix so we'll resume that on uh on + + + align:start position:0% +Matrix so we'll resume that on uh on +Tuesday but uh but uh so don't worry too + + align:start position:0% +Tuesday but uh but uh so don't worry too + + + align:start position:0% +Tuesday but uh but uh so don't worry too +much this is not going to if this going + + align:start position:0% +much this is not going to if this going + + + align:start position:0% +much this is not going to if this going +too fast I'm not supposed to cover it + + align:start position:0% +too fast I'm not supposed to cover it + + + align:start position:0% +too fast I'm not supposed to cover it +but just so you get a hint of why + + align:start position:0% +but just so you get a hint of why + + + align:start position:0% +but just so you get a hint of why +currence theorem actually uh was uh + + align:start position:0% +currence theorem actually uh was uh + + + align:start position:0% +currence theorem actually uh was uh +useful all right + + align:start position:0% +useful all right + + + align:start position:0% +useful all right +so I don't know if we actually ended up + + align:start position:0% +so I don't know if we actually ended up + + + align:start position:0% +so I don't know if we actually ended up +recording uh I have your uh homework and + + align:start position:0% +recording uh I have your uh homework and + + + align:start position:0% +recording uh I have your uh homework and +uh as usual I will give it to you side \ No newline at end of file diff --git a/K1vpc9YwlQI.txt b/K1vpc9YwlQI.txt new file mode 100644 index 0000000000000000000000000000000000000000..f0a2cc1764ec434f757861c2f85f5977932b0e0c --- /dev/null +++ b/K1vpc9YwlQI.txt @@ -0,0 +1,8347 @@ +align:start position:0% + +so we'll pick up where we ended last + + align:start position:0% +so we'll pick up where we ended last + + + align:start position:0% +so we'll pick up where we ended last +time we're looking at the space time of + + align:start position:0% +time we're looking at the space time of + + + align:start position:0% +time we're looking at the space time of +a compact spherical body working in what + + align:start position:0% +a compact spherical body working in what + + + align:start position:0% +a compact spherical body working in what +we call Schwarzschild coordinates we + + align:start position:0% +we call Schwarzschild coordinates we + + + align:start position:0% +we call Schwarzschild coordinates we +deduced that the line element describing + + align:start position:0% +deduced that the line element describing + + + align:start position:0% +deduced that the line element describing +this body is of the form D s squared + + align:start position:0% +this body is of the form D s squared + + + align:start position:0% +this body is of the form D s squared +equals negative e to the 2 Phi DT + + align:start position:0% +equals negative e to the 2 Phi DT + + + align:start position:0% +equals negative e to the 2 Phi DT +squared plus D R squared divided by 1 + + align:start position:0% +squared plus D R squared divided by 1 + + + align:start position:0% +squared plus D R squared divided by 1 +minus 2 G M of R over R plus R squared D + + align:start position:0% +minus 2 G M of R over R plus R squared D + + + align:start position:0% +minus 2 G M of R over R plus R squared D +Omega where D Omega is the usual solid + + align:start position:0% +Omega where D Omega is the usual solid + + + align:start position:0% +Omega where D Omega is the usual solid +element line element and let's see ah + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +the body is described as a it's an + + align:start position:0% +the body is described as a it's an + + + align:start position:0% +the body is described as a it's an +interior as a perfect fluid with a + + align:start position:0% +interior as a perfect fluid with a + + + align:start position:0% +interior as a perfect fluid with a +particular density profile Rho of R a + + align:start position:0% +particular density profile Rho of R a + + + align:start position:0% +particular density profile Rho of R a +pressure profile P of R that describes + + align:start position:0% +pressure profile P of R that describes + + + align:start position:0% +pressure profile P of R that describes +this thing everywhere inside some radius + + align:start position:0% +this thing everywhere inside some radius + + + align:start position:0% +this thing everywhere inside some radius +R star which describes its which gives + + align:start position:0% +R star which describes its which gives + + + align:start position:0% +R star which describes its which gives +its surface sorry I just distracted + + align:start position:0% +its surface sorry I just distracted + + + align:start position:0% +its surface sorry I just distracted +myself I don't know why I've been + + align:start position:0% +myself I don't know why I've been + + + align:start position:0% +myself I don't know why I've been +calling this T Omega T Omega squared + + align:start position:0% +calling this T Omega T Omega squared + + + align:start position:0% +calling this T Omega T Omega squared +whatever fluffin that notation okay so + + align:start position:0% +whatever fluffin that notation okay so + + + align:start position:0% +whatever fluffin that notation okay so +in the exterior of this thing so for + + align:start position:0% +in the exterior of this thing so for + + + align:start position:0% +in the exterior of this thing so for +everywhere for R greater than R star it + + align:start position:0% +everywhere for R greater than R star it + + + align:start position:0% +everywhere for R greater than R star it +is vacuum there is no density there is + + align:start position:0% +is vacuum there is no density there is + + + align:start position:0% +is vacuum there is no density there is +no pressure once we're outside this + + align:start position:0% +no pressure once we're outside this + + + align:start position:0% +no pressure once we're outside this +thing the only mass you see is the mass + + align:start position:0% +thing the only mass you see is the mass + + + align:start position:0% +thing the only mass you see is the mass +of the star so another way of saying + + align:start position:0% +of the star so another way of saying + + + align:start position:0% +of the star so another way of saying +this is that well you know what I'll get + + align:start position:0% +this is that well you know what I'll get + + + align:start position:0% +this is that well you know what I'll get +to that in just a moment and in the + + align:start position:0% +to that in just a moment and in the + + + align:start position:0% +to that in just a moment and in the +exterior the e to the 2 Phi becomes 1 + + align:start position:0% +exterior the e to the 2 Phi becomes 1 + + + align:start position:0% +exterior the e to the 2 Phi becomes 1 +minus 2 G that same mass over R + + align:start position:0% +minus 2 G that same mass over R + + + align:start position:0% +minus 2 G that same mass over R +everywhere in the interior the pressure + + align:start position:0% +everywhere in the interior the pressure + + + align:start position:0% +everywhere in the interior the pressure +the function Phi and the mass R are + + align:start position:0% +the function Phi and the mass R are + + + align:start position:0% +the function Phi and the mass R are +governed by these equations so the mass + + align:start position:0% +governed by these equations so the mass + + + align:start position:0% +governed by these equations so the mass +as I described last time it looks like a + + align:start position:0% +as I described last time it looks like a + + + align:start position:0% +as I described last time it looks like a +deceptively simple spherical integral + + align:start position:0% +deceptively simple spherical integral + + + align:start position:0% +deceptively simple spherical integral +but just be aware that when you do this + + align:start position:0% +but just be aware that when you do this + + + align:start position:0% +but just be aware that when you do this +you are not integrating over a proper + + align:start position:0% +you are not integrating over a proper + + + align:start position:0% +you are not integrating over a proper +volume okay if you were to integrate + + align:start position:0% +volume okay if you were to integrate + + + align:start position:0% +volume okay if you were to integrate +over a proper volume you would get a + + align:start position:0% +over a proper volume you would get a + + + align:start position:0% +over a proper volume you would get a +larger mass and such a mass in fact does + + align:start position:0% +larger mass and such a mass in fact does + + + align:start position:0% +larger mass and such a mass in fact does +have meaning to it and it describes the + + align:start position:0% +have meaning to it and it describes the + + + align:start position:0% +have meaning to it and it describes the +difference between that mass and this + + align:start position:0% +difference between that mass and this + + + align:start position:0% +difference between that mass and this +mass tells you something about how + + align:start position:0% +mass tells you something about how + + + align:start position:0% +mass tells you something about how +gravitationally bound this object is and + + align:start position:0% +gravitationally bound this object is and + + + align:start position:0% +gravitationally bound this object is and +these two equations actually have a + + align:start position:0% +these two equations actually have a + + + align:start position:0% +these two equations actually have a +Newtonian lemon too so + + align:start position:0% +Newtonian lemon too so + + + align:start position:0% +Newtonian lemon too so +so this is a relative relativistic + + align:start position:0% +so this is a relative relativistic + + + align:start position:0% +so this is a relative relativistic +version of the equation of hydrostatic + + align:start position:0% +version of the equation of hydrostatic + + + align:start position:0% +version of the equation of hydrostatic +equilibrium and this has a simple + + align:start position:0% +equilibrium and this has a simple + + + align:start position:0% +equilibrium and this has a simple +Newtonian analogue drop the - I know + + align:start position:0% +Newtonian analogue drop the - I know + + + align:start position:0% +Newtonian analogue drop the - I know +this is a simple Newtonian analogue + + align:start position:0% +this is a simple Newtonian analogue + + + align:start position:0% +this is a simple Newtonian analogue +describing the gravitational potential + + align:start position:0% +describing the gravitational potential + + + align:start position:0% +describing the gravitational potential +inside a fluid object these whole things + + align:start position:0% +inside a fluid object these whole things + + + align:start position:0% +inside a fluid object these whole things +taken together are called the Tollman + + align:start position:0% +taken together are called the Tollman + + + align:start position:0% +taken together are called the Tollman +Oppenheimer volkoff equations or the T o + + align:start position:0% +Oppenheimer volkoff equations or the T o + + + align:start position:0% +Oppenheimer volkoff equations or the T o +V equations so the one comment I was + + align:start position:0% +V equations so the one comment I was + + + align:start position:0% +V equations so the one comment I was +making was that we require M of R star + + align:start position:0% +making was that we require M of R star + + + align:start position:0% +making was that we require M of R star +to equal M the total mass of this object + + align:start position:0% +to equal M the total mass of this object + + + align:start position:0% +to equal M the total mass of this object +okay so that's another kind of condition + + align:start position:0% +okay so that's another kind of condition + + + align:start position:0% +okay so that's another kind of condition +on this why don't you integrate up then + + align:start position:0% +on this why don't you integrate up then + + + align:start position:0% +on this why don't you integrate up then +you switch over to the mass the total + + align:start position:0% +you switch over to the mass the total + + + align:start position:0% +you switch over to the mass the total +mass that is used in the exterior of + + align:start position:0% +mass that is used in the exterior of + + + align:start position:0% +mass that is used in the exterior of +this star so if you wish to solve these + + align:start position:0% +this star so if you wish to solve these + + + align:start position:0% +this star so if you wish to solve these +things what you basically do is just + + align:start position:0% +things what you basically do is just + + + align:start position:0% +things what you basically do is just +choose a central density you have to + + align:start position:0% +choose a central density you have to + + + align:start position:0% +choose a central density you have to +choose an equation of state which allows + + align:start position:0% +choose an equation of state which allows + + + align:start position:0% +choose an equation of state which allows +you to relate the pressure to the + + align:start position:0% +you to relate the pressure to the + + + align:start position:0% +you to relate the pressure to the +density we will talk about that a little + + align:start position:0% +density we will talk about that a little + + + align:start position:0% +density we will talk about that a little +bit more later in this class and then + + align:start position:0% +bit more later in this class and then + + + align:start position:0% +bit more later in this class and then +you just start integrating okay so you + + align:start position:0% +you just start integrating okay so you + + + align:start position:0% +you just start integrating okay so you +basically then integrate until you find + + align:start position:0% +basically then integrate until you find + + + align:start position:0% +basically then integrate until you find +that the pressure equals zero + + align:start position:0% +that the pressure equals zero + + + align:start position:0% +that the pressure equals zero +the radius at which this occurs defines + + align:start position:0% +the radius at which this occurs defines + + + align:start position:0% +the radius at which this occurs defines +the star's surface + + align:start position:0% + + + + align:start position:0% + +okay as you integrate a long this allows + + align:start position:0% +okay as you integrate a long this allows + + + align:start position:0% +okay as you integrate a long this allows +you to build up you then build the mast + + align:start position:0% +you to build up you then build the mast + + + align:start position:0% +you to build up you then build the mast +profile of the star the pressure profile + + align:start position:0% +profile of the star the pressure profile + + + align:start position:0% +profile of the star the pressure profile +on this star you are building up how the + + align:start position:0% +on this star you are building up how the + + + align:start position:0% +on this star you are building up how the +Phi's as you integrate along this star + + align:start position:0% +Phi's as you integrate along this star + + + align:start position:0% +Phi's as you integrate along this star +you then so this is noted if you + + align:start position:0% +you then so this is noted if you + + + align:start position:0% +you then so this is noted if you +integrate this up this is only defined + + align:start position:0% +integrate this up this is only defined + + + align:start position:0% +integrate this up this is only defined +up to a constant of integration and so + + align:start position:0% +up to a constant of integration and so + + + align:start position:0% +up to a constant of integration and so +what you then need to do is once you + + align:start position:0% +what you then need to do is once you + + + align:start position:0% +what you then need to do is once you +have reached the surface of the star you + + align:start position:0% +have reached the surface of the star you + + + align:start position:0% +have reached the surface of the star you +know M of R and so what you're going to + + align:start position:0% +know M of R and so what you're going to + + + align:start position:0% +know M of R and so what you're going to +need to do is adjust the Phi that you + + align:start position:0% +need to do is adjust the Phi that you + + + align:start position:0% +need to do is adjust the Phi that you +found in order to match with the + + align:start position:0% +found in order to match with the + + + align:start position:0% +found in order to match with the +exterior solution 1 minus 2 GM over R + + align:start position:0% +exterior solution 1 minus 2 GM over R + + + align:start position:0% +exterior solution 1 minus 2 GM over R +this is an exercise you will do on an + + align:start position:0% +this is an exercise you will do on an + + + align:start position:0% +this is an exercise you will do on an +upcoming homework assignment this is one + + align:start position:0% +upcoming homework assignment this is one + + + align:start position:0% +upcoming homework assignment this is one +of my favorite assignments in the class + + align:start position:0% +of my favorite assignments in the class + + + align:start position:0% +of my favorite assignments in the class +it's a really good chance to actually + + align:start position:0% +it's a really good chance to actually + + + align:start position:0% +it's a really good chance to actually +see the way we solved these equations + + align:start position:0% +see the way we solved these equations + + + align:start position:0% +see the way we solved these equations +and you know this kind of an exercise is + + align:start position:0% +and you know this kind of an exercise is + + + align:start position:0% +and you know this kind of an exercise is +it's it's done all the time as parts of + + align:start position:0% +it's it's done all the time as parts of + + + align:start position:0% +it's it's done all the time as parts of +modern research and you will do this for + + align:start position:0% +modern research and you will do this for + + + align:start position:0% +modern research and you will do this for +a particularly simple kind of equation + + align:start position:0% +a particularly simple kind of equation + + + align:start position:0% +a particularly simple kind of equation +of state so I want to look at what some + + align:start position:0% +of state so I want to look at what some + + + align:start position:0% +of state so I want to look at what some +examples of objects like this actually + + align:start position:0% +examples of objects like this actually + + + align:start position:0% +examples of objects like this actually +look like so what we're going to do is + + align:start position:0% +look like so what we're going to do is + + + align:start position:0% +look like so what we're going to do is +consider an unrealistic but instructive + + align:start position:0% +consider an unrealistic but instructive + + + align:start position:0% +consider an unrealistic but instructive +idealized limit so imagine a star that + + align:start position:0% +idealized limit so imagine a star that + + + align:start position:0% +idealized limit so imagine a star that +has Rho equal constant okay that is + + align:start position:0% +has Rho equal constant okay that is + + + align:start position:0% +has Rho equal constant okay that is +something where no matter how hard you + + align:start position:0% +something where no matter how hard you + + + align:start position:0% +something where no matter how hard you +squeeze it you cannot change its density + + align:start position:0% +squeeze it you cannot change its density + + + align:start position:0% +squeeze it you cannot change its density +the only way that that can happen is if + + align:start position:0% +the only way that that can happen is if + + + align:start position:0% +the only way that that can happen is if +you have an object that is infinitely + + align:start position:0% +you have an object that is infinitely + + + align:start position:0% +you have an object that is infinitely +stiff this corresponds to a speed of + + align:start position:0% +stiff this corresponds to a speed of + + + align:start position:0% +stiff this corresponds to a speed of +sound which is defined as DP D Rho that + + align:start position:0% +sound which is defined as DP D Rho that + + + align:start position:0% +sound which is defined as DP D Rho that +is infinite okay now of course no speed + + align:start position:0% +is infinite okay now of course no speed + + + align:start position:0% +is infinite okay now of course no speed +of sound can actually expect C the speed + + align:start position:0% +of sound can actually expect C the speed + + + align:start position:0% +of sound can actually expect C the speed +of light so this is a very somewhat + + align:start position:0% +of light so this is a very somewhat + + + align:start position:0% +of light so this is a very somewhat +pathological object nonetheless it's + + align:start position:0% +pathological object nonetheless it's + + + align:start position:0% +pathological object nonetheless it's +useful + + align:start position:0% +useful + + + align:start position:0% +useful +for the simple reason that the mass + + align:start position:0% +for the simple reason that the mass + + + align:start position:0% +for the simple reason that the mass +function that emerges for this it's + + align:start position:0% +function that emerges for this it's + + + align:start position:0% +function that emerges for this it's +quite trivial okay Rho is constant so + + align:start position:0% +quite trivial okay Rho is constant so + + + align:start position:0% +quite trivial okay Rho is constant so +emmav are just goes as the volume inside + + align:start position:0% +emmav are just goes as the volume inside + + + align:start position:0% +emmav are just goes as the volume inside +radius R times Rho this star then has a + + align:start position:0% +radius R times Rho this star then has a + + + align:start position:0% +radius R times Rho this star then has a +total mass of 4/3 PI R to be PI Rho arc + + align:start position:0% +total mass of 4/3 PI R to be PI Rho arc + + + align:start position:0% +total mass of 4/3 PI R to be PI Rho arc +R star cubed okay so we know how its + + align:start position:0% +R star cubed okay so we know how its + + + align:start position:0% +R star cubed okay so we know how its +density behaves it's a constant we know + + align:start position:0% +density behaves it's a constant we know + + + align:start position:0% +density behaves it's a constant we know +how the mass function behaves the + + align:start position:0% +how the mass function behaves the + + + align:start position:0% +how the mass function behaves the +challenge is solving for the pressure + + align:start position:0% +challenge is solving for the pressure + + + align:start position:0% +challenge is solving for the pressure +profile so the pressure is governed by + + align:start position:0% + + + + align:start position:0% + +taking this differential equation and + + align:start position:0% +taking this differential equation and + + + align:start position:0% +taking this differential equation and +basically plug in that mass plug in this + + align:start position:0% +basically plug in that mass plug in this + + + align:start position:0% +basically plug in that mass plug in this +mass function and see what you get okay + + align:start position:0% +mass function and see what you get okay + + + align:start position:0% +mass function and see what you get okay +so if I go and I throw this guy in here + + align:start position:0% + + + + align:start position:0% + +this is what you end up getting okay so + + align:start position:0% +this is what you end up getting okay so + + + align:start position:0% +this is what you end up getting okay so +bear in mind bear in mind as you go + + align:start position:0% +bear in mind bear in mind as you go + + + align:start position:0% +bear in mind bear in mind as you go +through this yeah I see what I did here + + align:start position:0% +through this yeah I see what I did here + + + align:start position:0% +through this yeah I see what I did here +so I do is I pulled out my factor of 4/3 + + align:start position:0% + + + + align:start position:0% + +4/3 PI Rho R cube to me my 4/3 PI R + + align:start position:0% +4/3 PI Rho R cube to me my 4/3 PI R + + + align:start position:0% +4/3 PI Rho R cube to me my 4/3 PI R +cubed I factor that out and then + + align:start position:0% +cubed I factor that out and then + + + align:start position:0% +cubed I factor that out and then +cancelled an overall factor of R square + + align:start position:0% +cancelled an overall factor of R square + + + align:start position:0% +cancelled an overall factor of R square +in the denominator okay so this is + + align:start position:0% +in the denominator okay so this is + + + align:start position:0% +in the denominator okay so this is +simply what I have over here with this + + align:start position:0% +simply what I have over here with this + + + align:start position:0% +simply what I have over here with this +mass function to find we want to solve + + align:start position:0% +mass function to find we want to solve + + + align:start position:0% +mass function to find we want to solve +this to find P this is one of those rare + + align:start position:0% +this to find P this is one of those rare + + + align:start position:0% +this to find P this is one of those rare +moments where nature and analysis sort + + align:start position:0% +moments where nature and analysis sort + + + align:start position:0% +moments where nature and analysis sort +of conspire and a miracle occurs ok it's + + align:start position:0% +of conspire and a miracle occurs ok it's + + + align:start position:0% +of conspire and a miracle occurs ok it's +a somewhat messy looking kind of + + align:start position:0% +a somewhat messy looking kind of + + + align:start position:0% +a somewhat messy looking kind of +solution but nonetheless it turns out + + align:start position:0% + + + + align:start position:0% + +that the pressure profile is determined + + align:start position:0% +that the pressure profile is determined + + + align:start position:0% +that the pressure profile is determined +by you can manipulate this equation you + + align:start position:0% +by you can manipulate this equation you + + + align:start position:0% +by you can manipulate this equation you +can integrate it up and this ends up + + align:start position:0% +can integrate it up and this ends up + + + align:start position:0% +can integrate it up and this ends up +describing what the pressure profile + + align:start position:0% +describing what the pressure profile + + + align:start position:0% +describing what the pressure profile +looks like P sub C is the pressure at R + + align:start position:0% +looks like P sub C is the pressure at R + + + align:start position:0% +looks like P sub C is the pressure at R +equals zero okay we define the surface + + align:start position:0% +equals zero okay we define the surface + + + align:start position:0% +equals zero okay we define the surface +of the star as being the location at + + align:start position:0% +of the star as being the location at + + + align:start position:0% +of the star as being the location at +which the pressure goes to zero so by + + align:start position:0% +which the pressure goes to zero so by + + + align:start position:0% +which the pressure goes to zero so by +using that we can actually so by + + align:start position:0% +using that we can actually so by + + + align:start position:0% +using that we can actually so by +exploiting that condition we can use + + align:start position:0% +exploiting that condition we can use + + + align:start position:0% +exploiting that condition we can use +this can you can use this equation to + + align:start position:0% +this can you can use this equation to + + + align:start position:0% +this can you can use this equation to +make a mapping between the radius of + + align:start position:0% +make a mapping between the radius of + + + align:start position:0% +make a mapping between the radius of +this star and the central pressure okay + + align:start position:0% +this star and the central pressure okay + + + align:start position:0% +this star and the central pressure okay +so these it's a spherically symmetric + + align:start position:0% +so these it's a spherically symmetric + + + align:start position:0% +so these it's a spherically symmetric +thing once we have chosen what this + + align:start position:0% +thing once we have chosen what this + + + align:start position:0% +thing once we have chosen what this +density is then there's essentially a 1 + + align:start position:0% +density is then there's essentially a 1 + + + align:start position:0% +density is then there's essentially a 1 +parameter family of solutions okay we if + + align:start position:0% +parameter family of solutions okay we if + + + align:start position:0% +parameter family of solutions okay we if +we choose the central pressure that + + align:start position:0% +we choose the central pressure that + + + align:start position:0% +we choose the central pressure that +determines what the radius would be + + align:start position:0% +determines what the radius would be + + + align:start position:0% +determines what the radius would be +conversely if we want to have a + + align:start position:0% +conversely if we want to have a + + + align:start position:0% +conversely if we want to have a +particular radius that determines what + + align:start position:0% +particular radius that determines what + + + align:start position:0% +particular radius that determines what +the central pressure must be let's just + + align:start position:0% +the central pressure must be let's just + + + align:start position:0% +the central pressure must be let's just +do a little analysis that follows from + + align:start position:0% +do a little analysis that follows from + + + align:start position:0% +do a little analysis that follows from +this so P equals 0 at R equals R star + + align:start position:0% +this so P equals 0 at R equals R star + + + align:start position:0% +this so P equals 0 at R equals R star +that defines the surface no putting all + + align:start position:0% +that defines the surface no putting all + + + align:start position:0% +that defines the surface no putting all +that together you can manipulate this + + align:start position:0% +that together you can manipulate this + + + align:start position:0% +that together you can manipulate this +equation to find that the radius of the + + align:start position:0% +equation to find that the radius of the + + + align:start position:0% +equation to find that the radius of the +star is determined from the central + + align:start position:0% +star is determined from the central + + + align:start position:0% +star is determined from the central +pressure like so if you prefer you can + + align:start position:0% +pressure like so if you prefer you can + + + align:start position:0% +pressure like so if you prefer you can +write this as an equation for the + + align:start position:0% +write this as an equation for the + + + align:start position:0% +write this as an equation for the +central pressure in terms of the radius + + align:start position:0% +central pressure in terms of the radius + + + align:start position:0% +central pressure in terms of the radius +of the star + + align:start position:0% + + + + align:start position:0% + +okay so I've written this in terms of M + + align:start position:0% +okay so I've written this in terms of M + + + align:start position:0% +okay so I've written this in terms of M +tote but M tote is of course simply + + align:start position:0% +tote but M tote is of course simply + + + align:start position:0% +tote but M tote is of course simply +related to this radius to me to this + + align:start position:0% +related to this radius to me to this + + + align:start position:0% +related to this radius to me to this +density and the Stars radius cubed okay + + align:start position:0% +density and the Stars radius cubed okay + + + align:start position:0% +density and the Stars radius cubed okay +so what's the importance of this this is + + align:start position:0% +so what's the importance of this this is + + + align:start position:0% +so what's the importance of this this is +as I've emphasized a fairly idealized + + align:start position:0% +as I've emphasized a fairly idealized + + + align:start position:0% +as I've emphasized a fairly idealized +problem nature will never give us an + + align:start position:0% +problem nature will never give us an + + + align:start position:0% +problem nature will never give us an +object it has constant density any + + align:start position:0% +object it has constant density any + + + align:start position:0% +object it has constant density any +object if you give it a little bit of a + + align:start position:0% +object if you give it a little bit of a + + + align:start position:0% +object if you give it a little bit of a +squeeze the density will change + + align:start position:0% +squeeze the density will change + + + align:start position:0% +squeeze the density will change +causality requires the dispute of sound + + align:start position:0% +causality requires the dispute of sound + + + align:start position:0% +causality requires the dispute of sound +be less than the speed of light so + + align:start position:0% +be less than the speed of light so + + + align:start position:0% +be less than the speed of light so +clearly this is a somewhat fictional + + align:start position:0% +clearly this is a somewhat fictional + + + align:start position:0% +clearly this is a somewhat fictional +limit but we can learn something very + + align:start position:0% +limit but we can learn something very + + + align:start position:0% +limit but we can learn something very +interesting about this notice that this + + align:start position:0% +interesting about this notice that this + + + align:start position:0% +interesting about this notice that this +formula for the central pressure it + + align:start position:0% +formula for the central pressure it + + + align:start position:0% +formula for the central pressure it +diverges for a particular compactness of + + align:start position:0% +diverges for a particular compactness of + + + align:start position:0% +diverges for a particular compactness of +the star so P sub C goes to infinity + + align:start position:0% +the star so P sub C goes to infinity + + + align:start position:0% +the star so P sub C goes to infinity +perhaps a little bit more easily to see + + align:start position:0% +perhaps a little bit more easily to see + + + align:start position:0% +perhaps a little bit more easily to see +the denominator goes to zero where a + + align:start position:0% +the denominator goes to zero where a + + + align:start position:0% +the denominator goes to zero where a +certain compactness M over R so let's + + align:start position:0% +certain compactness M over R so let's + + + align:start position:0% +certain compactness M over R so let's +look at the value at which the + + align:start position:0% +look at the value at which the + + + align:start position:0% +look at the value at which the +denominator goes to zero + + align:start position:0% + + + + align:start position:0% + +so let's see move my one to the other + + align:start position:0% +so let's see move my one to the other + + + align:start position:0% +so let's see move my one to the other +side divide by three square it rearrange + + align:start position:0% +side divide by three square it rearrange + + + align:start position:0% +side divide by three square it rearrange +terms so if the ratio of this stars + + align:start position:0% +terms so if the ratio of this stars + + + align:start position:0% +terms so if the ratio of this stars +total mass to its radius is such that GM + + align:start position:0% +total mass to its radius is such that GM + + + align:start position:0% +total mass to its radius is such that GM +over R star exceeds 4/9 then the + + align:start position:0% +over R star exceeds 4/9 then the + + + align:start position:0% +over R star exceeds 4/9 then the +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +diverges what this tells me is that I + + align:start position:0% +diverges what this tells me is that I + + + align:start position:0% +diverges what this tells me is that I +cannot construct a physically allowable + + align:start position:0% +cannot construct a physically allowable + + + align:start position:0% +cannot construct a physically allowable +static object even using this stiff as + + align:start position:0% +static object even using this stiff as + + + align:start position:0% +static object even using this stiff as +we can imagine fluid a fluid that has an + + align:start position:0% +we can imagine fluid a fluid that has an + + + align:start position:0% +we can imagine fluid a fluid that has an +infinite Sound speed I cannot make a + + align:start position:0% +infinite Sound speed I cannot make a + + + align:start position:0% +infinite Sound speed I cannot make a +star more compact than that + + align:start position:0% +star more compact than that + + + align:start position:0% +star more compact than that +okay I would need to have making it that + + align:start position:0% +okay I would need to have making it that + + + align:start position:0% +okay I would need to have making it that +compact requires infinite pressure at + + align:start position:0% +compact requires infinite pressure at + + + align:start position:0% +compact requires infinite pressure at +the core this implies that stars have a + + align:start position:0% +the core this implies that stars have a + + + align:start position:0% +the core this implies that stars have a +maximum compactness + + align:start position:0% + + + + align:start position:0% + +we cannot have physically realizable + + align:start position:0% + + + + align:start position:0% + +pressure profiles F and let's turn that + + align:start position:0% +pressure profiles F and let's turn that + + + align:start position:0% +pressure profiles F and let's turn that +around if the ratio of the radius to G + + align:start position:0% +around if the ratio of the radius to G + + + align:start position:0% +around if the ratio of the radius to G +times the total mass is smaller than + + align:start position:0% +times the total mass is smaller than + + + align:start position:0% +times the total mass is smaller than +nine fourths now this holds for the + + align:start position:0% +nine fourths now this holds for the + + + align:start position:0% +nine fourths now this holds for the +stiffest possible fluid that we can even + + align:start position:0% +stiffest possible fluid that we can even + + + align:start position:0% +stiffest possible fluid that we can even +imagine one which the laws of physics + + align:start position:0% +imagine one which the laws of physics + + + align:start position:0% +imagine one which the laws of physics +actually do not permit and so when in + + align:start position:0% +actually do not permit and so when in + + + align:start position:0% +actually do not permit and so when in +first from this actually that this bound + + align:start position:0% +first from this actually that this bound + + + align:start position:0% +first from this actually that this bound +basically tells me that given any + + align:start position:0% +basically tells me that given any + + + align:start position:0% +basically tells me that given any +physical physical fluid any physically + + align:start position:0% +physical physical fluid any physically + + + align:start position:0% +physical physical fluid any physically +realizable kind of star that I can + + align:start position:0% +realizable kind of star that I can + + + align:start position:0% +realizable kind of star that I can +construct I must have a maximum allowed + + align:start position:0% +construct I must have a maximum allowed + + + align:start position:0% +construct I must have a maximum allowed +compactness putting this a little bit + + align:start position:0% +compactness putting this a little bit + + + align:start position:0% +compactness putting this a little bit +more precisely brings us to a result + + align:start position:0% +more precisely brings us to a result + + + align:start position:0% +more precisely brings us to a result +that is known as book das theorem + + align:start position:0% + + + + align:start position:0% + +book dolls Niram tells me that there is + + align:start position:0% +book dolls Niram tells me that there is + + + align:start position:0% +book dolls Niram tells me that there is +no stable spherical fluid configuration + + align:start position:0% + + + + align:start position:0% + +in which the configurations radius is + + align:start position:0% +in which the configurations radius is + + + align:start position:0% +in which the configurations radius is +smaller than nine fourths of GM total + + align:start position:0% + + + + align:start position:0% + +for those of you who like to put factors + + align:start position:0% +for those of you who like to put factors + + + align:start position:0% +for those of you who like to put factors +of C in there divided by a C squared + + align:start position:0% +of C in there divided by a C squared + + + align:start position:0% +of C in there divided by a C squared +okay this tells you something but you + + align:start position:0% +okay this tells you something but you + + + align:start position:0% +okay this tells you something but you +can convert to SI units which tells you + + align:start position:0% +can convert to SI units which tells you + + + align:start position:0% +can convert to SI units which tells you +how small you're allowed to make an + + align:start position:0% +how small you're allowed to make an + + + align:start position:0% +how small you're allowed to make an +object you can prove this for so this is + + align:start position:0% +object you can prove this for so this is + + + align:start position:0% +object you can prove this for so this is +clear it emerges and very nicely in this + + align:start position:0% +clear it emerges and very nicely in this + + + align:start position:0% +clear it emerges and very nicely in this +idealized but unphysical fluid limit but + + align:start position:0% +idealized but unphysical fluid limit but + + + align:start position:0% +idealized but unphysical fluid limit but +it can be proven more in more generally + + align:start position:0% +it can be proven more in more generally + + + align:start position:0% +it can be proven more in more generally +you just have to set a few have to make + + align:start position:0% +you just have to set a few have to make + + + align:start position:0% +you just have to set a few have to make +a few assumptions about the way that the + + align:start position:0% +a few assumptions about the way that the + + + align:start position:0% +a few assumptions about the way that the +the pressure profile is not singular in + + align:start position:0% +the pressure profile is not singular in + + + align:start position:0% +the pressure profile is not singular in +any place proof of this can be found in + + align:start position:0% +any place proof of this can be found in + + + align:start position:0% +any place proof of this can be found in +the beautiful old textbook by Weinberg + + align:start position:0% + + + + align:start position:0% + +section eleven point six well when you + + align:start position:0% +section eleven point six well when you + + + align:start position:0% +section eleven point six well when you +hear something like that you got a sink + + align:start position:0% +hear something like that you got a sink + + + align:start position:0% +hear something like that you got a sink +to yourself well you know suppose I made + + align:start position:0% +to yourself well you know suppose I made + + + align:start position:0% +to yourself well you know suppose I made +a star with some kind of a fluid and I + + align:start position:0% +a star with some kind of a fluid and I + + + align:start position:0% +a star with some kind of a fluid and I +gave it a radius of ten fourth GM towed + + align:start position:0% +gave it a radius of ten fourth GM towed + + + align:start position:0% +gave it a radius of ten fourth GM towed +over c-squared + + align:start position:0% +over c-squared + + + align:start position:0% +over c-squared +and then I just came along and squeezed + + align:start position:0% +and then I just came along and squeezed + + + align:start position:0% +and then I just came along and squeezed +it what would happen well notice the + + align:start position:0% +it what would happen well notice the + + + align:start position:0% +it what would happen well notice the +word stable in this definition you're + + align:start position:0% +word stable in this definition you're + + + align:start position:0% +word stable in this definition you're +free to do that and should you do so you + + align:start position:0% +free to do that and should you do so you + + + align:start position:0% +free to do that and should you do so you +would simply no longer have a stable + + align:start position:0% +would simply no longer have a stable + + + align:start position:0% +would simply no longer have a stable +object so remember part of what went + + align:start position:0% +object so remember part of what went + + + align:start position:0% +object so remember part of what went +into + + align:start position:0% +into + + + align:start position:0% +into +this analysis is we were assuming the + + align:start position:0% +this analysis is we were assuming the + + + align:start position:0% +this analysis is we were assuming the +space-time and the fluid that is a + + align:start position:0% +space-time and the fluid that is a + + + align:start position:0% +space-time and the fluid that is a +source of this space-time we're assuming + + align:start position:0% +source of this space-time we're assuming + + + align:start position:0% +source of this space-time we're assuming +everything is static okay we're making + + align:start position:0% +everything is static okay we're making + + + align:start position:0% +everything is static okay we're making +sure everything just sort of sit still + + align:start position:0% +sure everything just sort of sit still + + + align:start position:0% +sure everything just sort of sit still +this is telling us you can't do that if + + align:start position:0% +this is telling us you can't do that if + + + align:start position:0% +this is telling us you can't do that if +you want to have a star as compact as + + align:start position:0% +you want to have a star as compact as + + + align:start position:0% +you want to have a star as compact as +that so if you were to do this it would + + align:start position:0% +that so if you were to do this it would + + + align:start position:0% +that so if you were to do this it would +collapse it would become dynamical and + + align:start position:0% +collapse it would become dynamical and + + + align:start position:0% +collapse it would become dynamical and +the space-time would transition into + + align:start position:0% +the space-time would transition into + + + align:start position:0% +the space-time would transition into +something else what that something else + + align:start position:0% +something else what that something else + + + align:start position:0% +something else what that something else +might be will be a topic that we get + + align:start position:0% +might be will be a topic that we get + + + align:start position:0% +might be will be a topic that we get +into a a little bit more after we've + + align:start position:0% +into a a little bit more after we've + + + align:start position:0% +into a a little bit more after we've +developed some additional material so + + align:start position:0% +developed some additional material so + + + align:start position:0% +developed some additional material so +let's talk a little bit this will help + + align:start position:0% +let's talk a little bit this will help + + + align:start position:0% +let's talk a little bit this will help +you with the homework assignment where + + align:start position:0% +you with the homework assignment where + + + align:start position:0% +you with the homework assignment where +you guys are going to construct + + align:start position:0% +you guys are going to construct + + + align:start position:0% +you guys are going to construct +relativistic stellar models let's talk + + align:start position:0% +relativistic stellar models let's talk + + + align:start position:0% +relativistic stellar models let's talk +about talk a little bit about how how we + + align:start position:0% +about talk a little bit about how how we + + + align:start position:0% +about talk a little bit about how how we +describe real objects okay they are not + + align:start position:0% +describe real objects okay they are not + + + align:start position:0% +describe real objects okay they are not +of constant density and they instead + + align:start position:0% +of constant density and they instead + + + align:start position:0% +of constant density and they instead +have some P that is a function of the + + align:start position:0% +have some P that is a function of the + + + align:start position:0% +have some P that is a function of the +density okay it's worth noting that in + + align:start position:0% +density okay it's worth noting that in + + + align:start position:0% +density okay it's worth noting that in +an even more general case this is + + align:start position:0% +an even more general case this is + + + align:start position:0% +an even more general case this is +actually worth up a brief aside the + + align:start position:0% +actually worth up a brief aside the + + + align:start position:0% +actually worth up a brief aside the +equation of state relates the pressure + + align:start position:0% +equation of state relates the pressure + + + align:start position:0% +equation of state relates the pressure +to local density and s where s is the + + align:start position:0% +to local density and s where s is the + + + align:start position:0% +to local density and s where s is the +entropy for the kind of applications + + align:start position:0% +entropy for the kind of applications + + + align:start position:0% +entropy for the kind of applications +where general relativity tends to be + + align:start position:0% +where general relativity tends to be + + + align:start position:0% +where general relativity tends to be +important for instance when we're + + align:start position:0% +important for instance when we're + + + align:start position:0% +important for instance when we're +studying the stellar structure of the + + align:start position:0% +studying the stellar structure of the + + + align:start position:0% +studying the stellar structure of the +structure of a neutron star the fluid + + align:start position:0% +structure of a neutron star the fluid + + + align:start position:0% +structure of a neutron star the fluid +ends up being so cold that you don't + + align:start position:0% +ends up being so cold that you don't + + + align:start position:0% +ends up being so cold that you don't +need to worry about the entropy and + + align:start position:0% +need to worry about the entropy and + + + align:start position:0% +need to worry about the entropy and +where that comes from is that when I + + align:start position:0% +where that comes from is that when I + + + align:start position:0% +where that comes from is that when I +revisit my first law of thermodynamics + + align:start position:0% +revisit my first law of thermodynamics + + + align:start position:0% +revisit my first law of thermodynamics +and I include + + align:start position:0% +and I include + + + align:start position:0% +and I include +temperature and entropy effects there's + + align:start position:0% +temperature and entropy effects there's + + + align:start position:0% +temperature and entropy effects there's +a term that I left out in my earlier + + align:start position:0% +a term that I left out in my earlier + + + align:start position:0% +a term that I left out in my earlier +accounting TDS okay if T is small I can + + align:start position:0% +accounting TDS okay if T is small I can + + + align:start position:0% +accounting TDS okay if T is small I can +ignore that term and it ends up being + + align:start position:0% +ignore that term and it ends up being + + + align:start position:0% +ignore that term and it ends up being +something where my local energy or + + align:start position:0% +something where my local energy or + + + align:start position:0% +something where my local energy or +energy density only is it ends up only + + align:start position:0% +energy density only is it ends up only + + + align:start position:0% +energy density only is it ends up only +depending on the pressure but that you + + align:start position:0% +depending on the pressure but that you + + + align:start position:0% +depending on the pressure but that you +know cold is a wiggle word I have to + + align:start position:0% +know cold is a wiggle word I have to + + + align:start position:0% +know cold is a wiggle word I have to +define a scale to say whether an object + + align:start position:0% +define a scale to say whether an object + + + align:start position:0% +define a scale to say whether an object +is cold or hot there's a few notes + + align:start position:0% +is cold or hot there's a few notes + + + align:start position:0% +is cold or hot there's a few notes +laying this out right in my notes let me + + align:start position:0% +laying this out right in my notes let me + + + align:start position:0% +laying this out right in my notes let me +just sketch the key idea cold depends on + + align:start position:0% +just sketch the key idea cold depends on + + + align:start position:0% +just sketch the key idea cold depends on +the fluids and it's worth noting that + + align:start position:0% +the fluids and it's worth noting that + + + align:start position:0% +the fluids and it's worth noting that +the kind of fluids you're playing with + + align:start position:0% +the kind of fluids you're playing with + + + align:start position:0% +the kind of fluids you're playing with +here it tend to be made out of fermions + + align:start position:0% +here it tend to be made out of fermions + + + align:start position:0% +here it tend to be made out of fermions +and so it depends on the fluids Fermi + + align:start position:0% +and so it depends on the fluids Fermi + + + align:start position:0% +and so it depends on the fluids Fermi +temperature okay so the Fermi + + align:start position:0% +temperature okay so the Fermi + + + align:start position:0% +temperature okay so the Fermi +temperature is defined as the Fermi + + align:start position:0% +temperature is defined as the Fermi + + + align:start position:0% +temperature is defined as the Fermi +energy normalized to a Boltzmann factor + + align:start position:0% +energy normalized to a Boltzmann factor + + + align:start position:0% +energy normalized to a Boltzmann factor +you get the Fermi energy by looking at + + align:start position:0% +you get the Fermi energy by looking at + + + align:start position:0% +you get the Fermi energy by looking at +how the energy levels are filled in your + + align:start position:0% +how the energy levels are filled in your + + + align:start position:0% +how the energy levels are filled in your +in your fermi on fluid here I have a few + + align:start position:0% +in your fermi on fluid here I have a few + + + align:start position:0% +in your fermi on fluid here I have a few +additional notes to sort of lay out the + + align:start position:0% +additional notes to sort of lay out the + + + align:start position:0% +additional notes to sort of lay out the +way in which you can relate this to the + + align:start position:0% +way in which you can relate this to the + + + align:start position:0% +way in which you can relate this to the +local density the mass of each particle + + align:start position:0% +local density the mass of each particle + + + align:start position:0% +local density the mass of each particle +that goes into this Fermi fluid the + + align:start position:0% +that goes into this Fermi fluid the + + + align:start position:0% +that goes into this Fermi fluid the +punchline is that four neutron stars one + + align:start position:0% +punchline is that four neutron stars one + + + align:start position:0% +punchline is that four neutron stars one +of the cases where we do in fact make + + align:start position:0% +of the cases where we do in fact make + + + align:start position:0% +of the cases where we do in fact make +dense general relativistic fluid stars + + align:start position:0% +dense general relativistic fluid stars + + + align:start position:0% +dense general relativistic fluid stars +the Fermi temperature tends to be on the + + align:start position:0% +the Fermi temperature tends to be on the + + + align:start position:0% +the Fermi temperature tends to be on the +order of 10 to the 13 Kelvin so about 10 + + align:start position:0% +order of 10 to the 13 Kelvin so about 10 + + + align:start position:0% +order of 10 to the 13 Kelvin so about 10 +trillion Kelvin when we actually observe + + align:start position:0% +trillion Kelvin when we actually observe + + + align:start position:0% +trillion Kelvin when we actually observe +these objects they are on the order of + + align:start position:0% +these objects they are on the order of + + + align:start position:0% +these objects they are on the order of +10 to 6 to 10 to the 9 Kelvin so they're + + align:start position:0% +10 to 6 to 10 to the 9 Kelvin so they're + + + align:start position:0% +10 to 6 to 10 to the 9 Kelvin so they're +a factor of about 10 to the seventh you + + align:start position:0% +a factor of about 10 to the seventh you + + + align:start position:0% +a factor of about 10 to the seventh you +know 10 to the 4 to 10 to the 7 times + + align:start position:0% +know 10 to the 4 to 10 to the 7 times + + + align:start position:0% +know 10 to the 4 to 10 to the 7 times +colder than the Fermi temperature even + + align:start position:0% +colder than the Fermi temperature even + + + align:start position:0% +colder than the Fermi temperature even +though they may be a billion Kelvin they + + align:start position:0% +though they may be a billion Kelvin they + + + align:start position:0% +though they may be a billion Kelvin they +are cold so we're gonna use what are + + align:start position:0% +are cold so we're gonna use what are + + + align:start position:0% +are cold so we're gonna use what are +called cold equations of state to + + align:start position:0% +called cold equations of state to + + + align:start position:0% +called cold equations of state to +describe these + + align:start position:0% +describe these + + + align:start position:0% +describe these +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +so with that out of the way let's talk a + + align:start position:0% +so with that out of the way let's talk a + + + align:start position:0% +so with that out of the way let's talk a +little bit about the kinds of equations + + align:start position:0% +little bit about the kinds of equations + + + align:start position:0% +little bit about the kinds of equations +of state that we will tend to use so + + align:start position:0% +of state that we will tend to use so + + + align:start position:0% +of state that we will tend to use so +people who study the physics of dense + + align:start position:0% +people who study the physics of dense + + + align:start position:0% +people who study the physics of dense +matter a lot of their lives is really + + align:start position:0% +matter a lot of their lives is really + + + align:start position:0% +matter a lot of their lives is really +down to understanding what the equation + + align:start position:0% +down to understanding what the equation + + + align:start position:0% +down to understanding what the equation +of state of that cold matter looks like + + align:start position:0% +of state of that cold matter looks like + + + align:start position:0% +of state of that cold matter looks like +some of our concern about hot matter as + + align:start position:0% +some of our concern about hot matter as + + + align:start position:0% +some of our concern about hot matter as +well which case they might be actually + + align:start position:0% +well which case they might be actually + + + align:start position:0% +well which case they might be actually +worrying about things at tens of + + align:start position:0% +worrying about things at tens of + + + align:start position:0% +worrying about things at tens of +trillions of Kelvin but if you're + + align:start position:0% +trillions of Kelvin but if you're + + + align:start position:0% +trillions of Kelvin but if you're +looking at Astrophysical applications + + align:start position:0% +looking at Astrophysical applications + + + align:start position:0% +looking at Astrophysical applications +you're generally interested in the cold + + align:start position:0% +you're generally interested in the cold + + + align:start position:0% +you're generally interested in the cold +matter and so they end up putting + + align:start position:0% +matter and so they end up putting + + + align:start position:0% +matter and so they end up putting +together very complicated models using + + align:start position:0% +together very complicated models using + + + align:start position:0% +together very complicated models using +QCD and effective field theories to try + + align:start position:0% +QCD and effective field theories to try + + + align:start position:0% +QCD and effective field theories to try +to understand how it is that a + + align:start position:0% +to understand how it is that a + + + align:start position:0% +to understand how it is that a +particular fluid of dense matter how its + + align:start position:0% +particular fluid of dense matter how its + + + align:start position:0% +particular fluid of dense matter how its +pressure and its density are related and + + align:start position:0% +pressure and its density are related and + + + align:start position:0% +pressure and its density are related and +what I'm sort of wheeling around here is + + align:start position:0% +what I'm sort of wheeling around here is + + + align:start position:0% +what I'm sort of wheeling around here is +that you generally do not have a simple + + align:start position:0% +that you generally do not have a simple + + + align:start position:0% +that you generally do not have a simple +analytic form you wind up with some kind + + align:start position:0% +analytic form you wind up with some kind + + + align:start position:0% +analytic form you wind up with some kind +of a fairly complicated function that + + align:start position:0% +of a fairly complicated function that + + + align:start position:0% +of a fairly complicated function that +emerges from a numerical calculation it + + align:start position:0% +emerges from a numerical calculation it + + + align:start position:0% +emerges from a numerical calculation it +often ends up being if you are a user of + + align:start position:0% +often ends up being if you are a user of + + + align:start position:0% +often ends up being if you are a user of +this equation of state it ends up being + + align:start position:0% +this equation of state it ends up being + + + align:start position:0% +this equation of state it ends up being +the form of a table so they might + + align:start position:0% +the form of a table so they might + + + align:start position:0% +the form of a table so they might +actually just give you a file that's got + + align:start position:0% +actually just give you a file that's got + + + align:start position:0% +actually just give you a file that's got +a bunch of numbers which says if the + + align:start position:0% +a bunch of numbers which says if the + + + align:start position:0% +a bunch of numbers which says if the +density is this then the pressure is + + align:start position:0% +density is this then the pressure is + + + align:start position:0% +density is this then the pressure is +this and you can sort of fits little + + align:start position:0% +this and you can sort of fits little + + + align:start position:0% +this and you can sort of fits little +functions to that that allow you to sort + + align:start position:0% +functions to that that allow you to sort + + + align:start position:0% +functions to that that allow you to sort +of look things up and do your + + align:start position:0% +of look things up and do your + + + align:start position:0% +of look things up and do your +calculations but it's not in the form of + + align:start position:0% +calculations but it's not in the form of + + + align:start position:0% +calculations but it's not in the form of +a clean thing that you can write down on + + align:start position:0% +a clean thing that you can write down on + + + align:start position:0% +a clean thing that you can write down on +the blackboard I want something clean + + align:start position:0% +the blackboard I want something clean + + + align:start position:0% +the blackboard I want something clean +that can write down the blackboard so + + align:start position:0% +that can write down the blackboard so + + + align:start position:0% +that can write down the blackboard so +I'm going to introduce an approximation + + align:start position:0% +I'm going to introduce an approximation + + + align:start position:0% +I'm going to introduce an approximation +which is useful for testing things out + + align:start position:0% +which is useful for testing things out + + + align:start position:0% +which is useful for testing things out +test cases and for pedagogy what we do + + align:start position:0% +test cases and for pedagogy what we do + + + align:start position:0% +test cases and for pedagogy what we do +is we take the pressure + + align:start position:0% + + + + align:start position:0% + +to be a power-law of the density okay so + + align:start position:0% +to be a power-law of the density okay so + + + align:start position:0% +to be a power-law of the density okay so +what we do is we write P equals K Rho + + align:start position:0% +what we do is we write P equals K Rho + + + align:start position:0% +what we do is we write P equals K Rho +zero to the gamma where K and gamma are + + align:start position:0% +zero to the gamma where K and gamma are + + + align:start position:0% +zero to the gamma where K and gamma are +constants we call this a form that looks + + align:start position:0% +constants we call this a form that looks + + + align:start position:0% +constants we call this a form that looks +like this + + align:start position:0% +like this + + + align:start position:0% +like this +this is called a poly trope now see + + align:start position:0% +this is called a poly trope now see + + + align:start position:0% +this is called a poly trope now see +which I particularly wants to highlight + + align:start position:0% +which I particularly wants to highlight + + + align:start position:0% +which I particularly wants to highlight +and for those of you who are going to do + + align:start position:0% +and for those of you who are going to do + + + align:start position:0% +and for those of you who are going to do +this highly recommended homework + + align:start position:0% +this highly recommended homework + + + align:start position:0% +this highly recommended homework +exercise please pay attention at this + + align:start position:0% +exercise please pay attention at this + + + align:start position:0% +exercise please pay attention at this +point this Rho 0 is not arrested this + + align:start position:0% +point this Rho 0 is not arrested this + + + align:start position:0% +point this Rho 0 is not arrested this +Rho 0 is not the row out there it is + + align:start position:0% +Rho 0 is not the row out there it is + + + align:start position:0% +Rho 0 is not the row out there it is +it's not the row that appears in the + + align:start position:0% +it's not the row that appears in the + + + align:start position:0% +it's not the row that appears in the +equation of states okay + + align:start position:0% +equation of states okay + + + align:start position:0% +equation of states okay +that is it's slightly different Rho 0 is + + align:start position:0% +that is it's slightly different Rho 0 is + + + align:start position:0% +that is it's slightly different Rho 0 is +not the road that appears for instance + + align:start position:0% +not the road that appears for instance + + + align:start position:0% +not the road that appears for instance +in the TIV equations Rho 0 is what is + + align:start position:0% +in the TIV equations Rho 0 is what is + + + align:start position:0% +in the TIV equations Rho 0 is what is +called the rest mass density it does not + + align:start position:0% +called the rest mass density it does not + + + align:start position:0% +called the rest mass density it does not +take into account the fact that if I + + align:start position:0% +take into account the fact that if I + + + align:start position:0% +take into account the fact that if I +take a big let's say I've got a big + + align:start position:0% +take a big let's say I've got a big + + + align:start position:0% +take a big let's say I've got a big +bucket of nuclear fluid okay so I take + + align:start position:0% +bucket of nuclear fluid okay so I take + + + align:start position:0% +bucket of nuclear fluid okay so I take +my bucket here and I squeeze down on it + + align:start position:0% +my bucket here and I squeeze down on it + + + align:start position:0% +my bucket here and I squeeze down on it +when I squeeze down its density is gonna + + align:start position:0% +when I squeeze down its density is gonna + + + align:start position:0% +when I squeeze down its density is gonna +increase first of all because I have + + align:start position:0% +increase first of all because I have + + + align:start position:0% +increase first of all because I have +decreased the volume okay so the number + + align:start position:0% +decreased the volume okay so the number + + + align:start position:0% +decreased the volume okay so the number +of particles remains fixed but I + + align:start position:0% +of particles remains fixed but I + + + align:start position:0% +of particles remains fixed but I +decrease the space at there and but I + + align:start position:0% +decrease the space at there and but I + + + align:start position:0% +decrease the space at there and but I +have also done work on it because this + + align:start position:0% +have also done work on it because this + + + align:start position:0% +have also done work on it because this +thing exerts a pressure that opposes my + + align:start position:0% +thing exerts a pressure that opposes my + + + align:start position:0% +thing exerts a pressure that opposes my +squeezing and I need to take into + + align:start position:0% +squeezing and I need to take into + + + align:start position:0% +squeezing and I need to take into +account the fact that the work I do in + + align:start position:0% +account the fact that the work I do in + + + align:start position:0% +account the fact that the work I do in +squeezing this fluid increases the + + align:start position:0% +squeezing this fluid increases the + + + align:start position:0% +squeezing this fluid increases the +density Rho + + align:start position:0% + + + + align:start position:0% + +okay so when you write out your TOB + + align:start position:0% +okay so when you write out your TOB + + + align:start position:0% +okay so when you write out your TOB +equations ro is energy density all forms + + align:start position:0% +equations ro is energy density all forms + + + align:start position:0% +equations ro is energy density all forms +of energy gravitate this is just the way + + align:start position:0% +of energy gravitate this is just the way + + + align:start position:0% +of energy gravitate this is just the way +people traditionally write the equation + + align:start position:0% +people traditionally write the equation + + + align:start position:0% +people traditionally write the equation +of state this is when one is doing + + align:start position:0% +of state this is when one is doing + + + align:start position:0% +of state this is when one is doing +nuclear physics there's good reasons for + + align:start position:0% +nuclear physics there's good reasons for + + + align:start position:0% +nuclear physics there's good reasons for +doing this but it's not the most + + align:start position:0% +doing this but it's not the most + + + align:start position:0% +doing this but it's not the most +convenient form for the kind of + + align:start position:0% +convenient form for the kind of + + + align:start position:0% +convenient form for the kind of +calculations that we want to do and that + + align:start position:0% +calculations that we want to do and that + + + align:start position:0% +calculations that we want to do and that +you are going to want to do in your in + + align:start position:0% +you are going to want to do in your in + + + align:start position:0% +you are going to want to do in your in +the problem set fortunately it's not too + + align:start position:0% +the problem set fortunately it's not too + + + align:start position:0% +the problem set fortunately it's not too +difficult to convert so let me describe + + align:start position:0% +difficult to convert so let me describe + + + align:start position:0% +difficult to convert so let me describe +to you how you do that + + align:start position:0% + + + + align:start position:0% + +so we're going to use the first law of + + align:start position:0% +so we're going to use the first law of + + + align:start position:0% +so we're going to use the first law of +thermodynamics in a form in which I have + + align:start position:0% +thermodynamics in a form in which I have + + + align:start position:0% +thermodynamics in a form in which I have +written in now a couple times + + align:start position:0% +written in now a couple times + + + align:start position:0% +written in now a couple times +interestingly it showed up in our + + align:start position:0% +interestingly it showed up in our + + + align:start position:0% +interestingly it showed up in our +cosmology lecture so my first law tells + + align:start position:0% +cosmology lecture so my first law tells + + + align:start position:0% +cosmology lecture so my first law tells +me D u equals minus pressure DV so this + + align:start position:0% +me D u equals minus pressure DV so this + + + align:start position:0% +me D u equals minus pressure DV so this +is my total energy in a fluid element + + align:start position:0% +is my total energy in a fluid element + + + align:start position:0% +is my total energy in a fluid element +and this is the work done on a fluid + + align:start position:0% +and this is the work done on a fluid + + + align:start position:0% +and this is the work done on a fluid +element so Rho is equal to the amount of + + align:start position:0% +element so Rho is equal to the amount of + + + align:start position:0% +element so Rho is equal to the amount of +energy in a fiducial volume my rest + + align:start position:0% +energy in a fiducial volume my rest + + + align:start position:0% +energy in a fiducial volume my rest +energy excuse me my rest density is the + + align:start position:0% +energy excuse me my rest density is the + + + align:start position:0% +energy excuse me my rest density is the +rest energy of every little body that + + align:start position:0% +rest energy of every little body that + + + align:start position:0% +rest energy of every little body that +goes into this per unit volume this + + align:start position:0% +goes into this per unit volume this + + + align:start position:0% +goes into this per unit volume this +means that I can write D U as D Rho over + + align:start position:0% +means that I can write D U as D Rho over + + + align:start position:0% +means that I can write D U as D Rho over +Rho 0 provided I throw in an extra + + align:start position:0% +Rho 0 provided I throw in an extra + + + align:start position:0% +Rho 0 provided I throw in an extra +factor of M rest to get the dimensions + + align:start position:0% +factor of M rest to get the dimensions + + + align:start position:0% +factor of M rest to get the dimensions +right and I can write D volume as D 1 + + align:start position:0% +right and I can write D volume as D 1 + + + align:start position:0% +right and I can write D volume as D 1 +over Rho 0 provided I throw in that + + align:start position:0% +over Rho 0 provided I throw in that + + + align:start position:0% +over Rho 0 provided I throw in that +factor of M rest to get the dimensions + + align:start position:0% +factor of M rest to get the dimensions + + + align:start position:0% +factor of M rest to get the dimensions +right ok I know this looks weird but + + align:start position:0% +right ok I know this looks weird but + + + align:start position:0% +right ok I know this looks weird but +it's perfectly valid ok so I'm going to + + align:start position:0% +it's perfectly valid ok so I'm going to + + + align:start position:0% +it's perfectly valid ok so I'm going to +rewrite my first law of thermodynamics + + align:start position:0% +rewrite my first law of thermodynamics + + + align:start position:0% +rewrite my first law of thermodynamics +as D Rho over Rho 0 equals minus P + + align:start position:0% +as D Rho over Rho 0 equals minus P + + + align:start position:0% +as D Rho over Rho 0 equals minus P +d 1 over r 0 let's manipulate that right + + align:start position:0% +d 1 over r 0 let's manipulate that right + + + align:start position:0% +d 1 over r 0 let's manipulate that right +hand side so I'm going to assume this + + align:start position:0% +hand side so I'm going to assume this + + + align:start position:0% +hand side so I'm going to assume this +polytropic form I'm gonna use P equals K + + align:start position:0% +polytropic form I'm gonna use P equals K + + + align:start position:0% +polytropic form I'm gonna use P equals K +row 0 to the gamma I'm gonna switch that + + align:start position:0% +row 0 to the gamma I'm gonna switch that + + + align:start position:0% +row 0 to the gamma I'm gonna switch that +around I'm gonna write this as Rho 0 + + align:start position:0% +around I'm gonna write this as Rho 0 + + + align:start position:0% +around I'm gonna write this as Rho 0 +equals P over K to the power of 1 over + + align:start position:0% +equals P over K to the power of 1 over + + + align:start position:0% +equals P over K to the power of 1 over +gamma ok so when I do that I get D Rho + + align:start position:0% +gamma ok so when I do that I get D Rho + + + align:start position:0% +gamma ok so when I do that I get D Rho +over Rho 0 equals capital 1 over gamma + + align:start position:0% +over Rho 0 equals capital 1 over gamma + + + align:start position:0% +over Rho 0 equals capital 1 over gamma +over kappa p DP over P to the 1 plus 1 + + align:start position:0% +over kappa p DP over P to the 1 plus 1 + + + align:start position:0% +over kappa p DP over P to the 1 plus 1 +over gamma + + align:start position:0% + + + + align:start position:0% + +a part of me just one moment I did + + align:start position:0% +a part of me just one moment I did + + + align:start position:0% +a part of me just one moment I did +something clever in my notes here and + + align:start position:0% +something clever in my notes here and + + + align:start position:0% +something clever in my notes here and +I'm just trying to make sure I + + align:start position:0% +I'm just trying to make sure I + + + align:start position:0% +I'm just trying to make sure I +understand what the hell I actually did + + align:start position:0% + + + + align:start position:0% + +so I'm gonna level with you I've gone + + align:start position:0% +so I'm gonna level with you I've gone + + + align:start position:0% +so I'm gonna level with you I've gone +through this several times there's a + + align:start position:0% +through this several times there's a + + + align:start position:0% +through this several times there's a +step in the calculation that at this + + align:start position:0% +step in the calculation that at this + + + align:start position:0% +step in the calculation that at this +point I for some stupid reason didn't + + align:start position:0% +point I for some stupid reason didn't + + + align:start position:0% +point I for some stupid reason didn't +write down I'm gonna trust and knew what + + align:start position:0% +write down I'm gonna trust and knew what + + + align:start position:0% +write down I'm gonna trust and knew what +I was doing though because I know the + + align:start position:0% +I was doing though because I know the + + + align:start position:0% +I was doing though because I know the +final result was right you can integrate + + align:start position:0% +final result was right you can integrate + + + align:start position:0% +final result was right you can integrate +up both sides here oh I think I see what + + align:start position:0% +up both sides here oh I think I see what + + + align:start position:0% +up both sides here oh I think I see what +I did okay so you integrate up both + + align:start position:0% +I did okay so you integrate up both + + + align:start position:0% +I did okay so you integrate up both +sides here and what you find is this + + align:start position:0% +sides here and what you find is this + + + align:start position:0% +sides here and what you find is this +becomes Rho equals P over gamma minus 1 + + align:start position:0% + + + + align:start position:0% + +plus a constant yeah I'm not a hundred + + align:start position:0% +plus a constant yeah I'm not a hundred + + + align:start position:0% +plus a constant yeah I'm not a hundred +percent sure how I actually did that so + + align:start position:0% +percent sure how I actually did that so + + + align:start position:0% +percent sure how I actually did that so +my apologies on that um I'm just gonna + + align:start position:0% +my apologies on that um I'm just gonna + + + align:start position:0% +my apologies on that um I'm just gonna +assume any what I was doing I will try + + align:start position:0% +assume any what I was doing I will try + + + align:start position:0% +assume any what I was doing I will try +to fix this and I may post an addendum + + align:start position:0% +to fix this and I may post an addendum + + + align:start position:0% +to fix this and I may post an addendum +here the next step actually is you want + + align:start position:0% +here the next step actually is you want + + + align:start position:0% +here the next step actually is you want +to determine what that constant is and + + align:start position:0% +to determine what that constant is and + + + align:start position:0% +to determine what that constant is and +so the way you determine the constant is + + align:start position:0% +so the way you determine the constant is + + + align:start position:0% +so the way you determine the constant is +you take advantage of the fact that Rho + + align:start position:0% +you take advantage of the fact that Rho + + + align:start position:0% +you take advantage of the fact that Rho +goes to Rho zero the energy density + + align:start position:0% +goes to Rho zero the energy density + + + align:start position:0% +goes to Rho zero the energy density +becomes the rest energy density if there + + align:start position:0% +becomes the rest energy density if there + + + align:start position:0% +becomes the rest energy density if there +is no pressure exerted and so this gives + + align:start position:0% +is no pressure exerted and so this gives + + + align:start position:0% +is no pressure exerted and so this gives +us our final relationship here which is + + align:start position:0% +us our final relationship here which is + + + align:start position:0% +us our final relationship here which is +that Rho equals Rho zero plus P over + + align:start position:0% +that Rho equals Rho zero plus P over + + + align:start position:0% +that Rho equals Rho zero plus P over +gamma minus one + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay I will double-check how I went from + + align:start position:0% +okay I will double-check how I went from + + + align:start position:0% +okay I will double-check how I went from +line two to line three there but the + + align:start position:0% +line two to line three there but the + + + align:start position:0% +line two to line three there but the +final thing that I have boxed on line + + align:start position:0% +final thing that I have boxed on line + + + align:start position:0% +final thing that I have boxed on line +four is indeed exactly what you need to + + align:start position:0% +four is indeed exactly what you need to + + + align:start position:0% +four is indeed exactly what you need to +do in order to build a stellar model so + + align:start position:0% +do in order to build a stellar model so + + + align:start position:0% +do in order to build a stellar model so +you guys are going to I guess I've been + + align:start position:0% +you guys are going to I guess I've been + + + align:start position:0% +you guys are going to I guess I've been +emphasizing this is something you will + + align:start position:0% +emphasizing this is something you will + + + align:start position:0% +emphasizing this is something you will +do on an upcoming problem set let me + + align:start position:0% +do on an upcoming problem set let me + + + align:start position:0% +do on an upcoming problem set let me +just sketch the recipe okay I've said + + align:start position:0% +just sketch the recipe okay I've said + + + align:start position:0% +just sketch the recipe okay I've said +this verbally but let me just write it + + align:start position:0% +this verbally but let me just write it + + + align:start position:0% +this verbally but let me just write it +out explicitly here so I will give you + + align:start position:0% +out explicitly here so I will give you + + + align:start position:0% +out explicitly here so I will give you +an equation of state you then need to + + align:start position:0% +an equation of state you then need to + + + align:start position:0% +an equation of state you then need to +pick row 0 at R equals 0 this will then + + align:start position:0% +pick row 0 at R equals 0 this will then + + + align:start position:0% +pick row 0 at R equals 0 this will then +using your equation of state and using + + align:start position:0% +using your equation of state and using + + + align:start position:0% +using your equation of state and using +that relationship between row and row 0 + + align:start position:0% +that relationship between row and row 0 + + + align:start position:0% +that relationship between row and row 0 +this will give you row at the center + + align:start position:0% +this will give you row at the center + + + align:start position:0% +this will give you row at the center +pressure at the center set M of R at the + + align:start position:0% +pressure at the center set M of R at the + + + align:start position:0% +pressure at the center set M of R at the +center to 0 I emphasize again that this + + align:start position:0% +center to 0 I emphasize again that this + + + align:start position:0% +center to 0 I emphasize again that this +may seem obvious but it is somewhat + + align:start position:0% +may seem obvious but it is somewhat + + + align:start position:0% +may seem obvious but it is somewhat +important that you get it right and I + + align:start position:0% +important that you get it right and I + + + align:start position:0% +important that you get it right and I +will have when you do this homework + + align:start position:0% +will have when you do this homework + + + align:start position:0% +will have when you do this homework +assignment I'll give you a little hint + + align:start position:0% +assignment I'll give you a little hint + + + align:start position:0% +assignment I'll give you a little hint +as to how to build that in smoothly it + + align:start position:0% +as to how to build that in smoothly it + + + align:start position:0% +as to how to build that in smoothly it +give me a little bit I'm gonna say + + align:start position:0% +give me a little bit I'm gonna say + + + align:start position:0% +give me a little bit I'm gonna say +tricky but there's a it's worth thinking + + align:start position:0% +tricky but there's a it's worth thinking + + + align:start position:0% +tricky but there's a it's worth thinking +about a little bit then what you do is + + align:start position:0% +about a little bit then what you do is + + + align:start position:0% +about a little bit then what you do is +integrate your equations for the + + align:start position:0% +integrate your equations for the + + + align:start position:0% +integrate your equations for the +pressure in the mass from R equals 0 and + + align:start position:0% +pressure in the mass from R equals 0 and + + + align:start position:0% +pressure in the mass from R equals 0 and +this cannot be done analytically you + + align:start position:0% +this cannot be done analytically you + + + align:start position:0% +this cannot be done analytically you +have to use a numerical integrator + + align:start position:0% + + + + align:start position:0% + +if you have never used one of these + + align:start position:0% +if you have never used one of these + + + align:start position:0% +if you have never used one of these +before I will give you a Mathematica + + align:start position:0% +before I will give you a Mathematica + + + align:start position:0% +before I will give you a Mathematica +notebook that demonstrates how to use it + + align:start position:0% +notebook that demonstrates how to use it + + + align:start position:0% +notebook that demonstrates how to use it +this is a skill that is worth knowing + + align:start position:0% +this is a skill that is worth knowing + + + align:start position:0% +this is a skill that is worth knowing +okay the plain truth of the matter is + + align:start position:0% +okay the plain truth of the matter is + + + align:start position:0% +okay the plain truth of the matter is +that the class of problems that are + + align:start position:0% +that the class of problems that are + + + align:start position:0% +that the class of problems that are +amenable to purely analytic solutions is + + align:start position:0% +amenable to purely analytic solutions is + + + align:start position:0% +amenable to purely analytic solutions is +it's it's those are interesting they're + + align:start position:0% +it's it's those are interesting they're + + + align:start position:0% +it's it's those are interesting they're +a lustrated they're good to work with + + align:start position:0% +a lustrated they're good to work with + + + align:start position:0% +a lustrated they're good to work with +but they tend to be unphysical and + + align:start position:0% +but they tend to be unphysical and + + + align:start position:0% +but they tend to be unphysical and +they're just not the ones that are of + + align:start position:0% +they're just not the ones that are of + + + align:start position:0% +they're just not the ones that are of +interest for many things that we study + + align:start position:0% +interest for many things that we study + + + align:start position:0% +interest for many things that we study +in science you can also so while you're + + align:start position:0% +in science you can also so while you're + + + align:start position:0% +in science you can also so while you're +doing this this is not necessary to make + + align:start position:0% +doing this this is not necessary to make + + + align:start position:0% +doing this this is not necessary to make +your your model but it's very useful to + + align:start position:0% +your your model but it's very useful to + + + align:start position:0% +your your model but it's very useful to +do this you can also integrate + + align:start position:0% + + + + align:start position:0% + +D Phi D R from the center so a caution + + align:start position:0% +D Phi D R from the center so a caution + + + align:start position:0% +D Phi D R from the center so a caution +is that you do not know Phi at R equals + + align:start position:0% +is that you do not know Phi at R equals + + + align:start position:0% +is that you do not know Phi at R equals +0 so what you should do is just + + align:start position:0% +0 so what you should do is just + + + align:start position:0% +0 so what you should do is just +temporarily set it equal to zero and + + align:start position:0% +temporarily set it equal to zero and + + + align:start position:0% +temporarily set it equal to zero and +what you're going to be doing then when + + align:start position:0% +what you're going to be doing then when + + + align:start position:0% +what you're going to be doing then when +you integrate this up is you will + + align:start position:0% +you integrate this up is you will + + + align:start position:0% +you integrate this up is you will +calculate the Delta Phi that describes + + align:start position:0% +calculate the Delta Phi that describes + + + align:start position:0% +calculate the Delta Phi that describes +your model from the center to the + + align:start position:0% +your model from the center to the + + + align:start position:0% +your model from the center to the +surface + + align:start position:0% +surface + + + align:start position:0% +surface +which brings me to step four when you + + align:start position:0% +which brings me to step four when you + + + align:start position:0% +which brings me to step four when you +find key equals zero + + align:start position:0% +find key equals zero + + + align:start position:0% +find key equals zero +you've hit the surface so what we do is + + align:start position:0% +you've hit the surface so what we do is + + + align:start position:0% +you've hit the surface so what we do is +we use the fact that P of R equals zero + + align:start position:0% +we use the fact that P of R equals zero + + + align:start position:0% +we use the fact that P of R equals zero +defines the Stars radius R star once + + align:start position:0% +defines the Stars radius R star once + + + align:start position:0% +defines the Stars radius R star once +you've done that you now know the total + + align:start position:0% +you've done that you now know the total + + + align:start position:0% +you've done that you now know the total +mass and the radius so you will find + + align:start position:0% +mass and the radius so you will find + + + align:start position:0% +mass and the radius so you will find +when you're doing this that you're in + + align:start position:0% +when you're doing this that you're in + + + align:start position:0% +when you're doing this that you're in +numerical integrator is not super well + + align:start position:0% +numerical integrator is not super well + + + align:start position:0% +numerical integrator is not super well +behaved as you approach the surface okay + + align:start position:0% +behaved as you approach the surface okay + + + align:start position:0% +behaved as you approach the surface okay +this is a feature not a bug what's going + + align:start position:0% +this is a feature not a bug what's going + + + align:start position:0% +this is a feature not a bug what's going +on is that as you begin to approach the + + align:start position:0% +on is that as you begin to approach the + + + align:start position:0% +on is that as you begin to approach the +surface the gradient and the pressure + + align:start position:0% +surface the gradient and the pressure + + + align:start position:0% +surface the gradient and the pressure +gets quite steep and so the way one + + align:start position:0% +gets quite steep and so the way one + + + align:start position:0% +gets quite steep and so the way one +numerically integrates a set of coupled + + align:start position:0% +numerically integrates a set of coupled + + + align:start position:0% +numerically integrates a set of coupled +equations like this is by essentially + + align:start position:0% +equations like this is by essentially + + + align:start position:0% +equations like this is by essentially +you take advantage of the fact that an + + align:start position:0% +you take advantage of the fact that an + + + align:start position:0% +you take advantage of the fact that an +integral is it's what you get by sort of + + align:start position:0% +integral is it's what you get by sort of + + + align:start position:0% +integral is it's what you get by sort of +dividing things up into tiny little + + align:start position:0% +dividing things up into tiny little + + + align:start position:0% +dividing things up into tiny little +space place it a little pieces and add + + align:start position:0% +space place it a little pieces and add + + + align:start position:0% +space place it a little pieces and add +up like you know little rectangles and + + align:start position:0% +up like you know little rectangles and + + + align:start position:0% +up like you know little rectangles and +when you're solving a differential + + align:start position:0% +when you're solving a differential + + + align:start position:0% +when you're solving a differential +equation like this you're essentially + + align:start position:0% +equation like this you're essentially + + + align:start position:0% +equation like this you're essentially +taking the continuum solution that you + + align:start position:0% +taking the continuum solution that you + + + align:start position:0% +taking the continuum solution that you +guys have learned how to do in many + + align:start position:0% +guys have learned how to do in many + + + align:start position:0% +guys have learned how to do in many +cases you're approximating it by a + + align:start position:0% +cases you're approximating it by a + + + align:start position:0% +cases you're approximating it by a +series of smaller and smaller finite + + align:start position:0% +series of smaller and smaller finite + + + align:start position:0% +series of smaller and smaller finite +steps because the gradient and the + + align:start position:0% +steps because the gradient and the + + + align:start position:0% +steps because the gradient and the +pressure gets large as you approach the + + align:start position:0% +pressure gets large as you approach the + + + align:start position:0% +pressure gets large as you approach the +surface numerical integrators typically + + align:start position:0% +surface numerical integrators typically + + + align:start position:0% +surface numerical integrators typically +try taking an infinite number of + + align:start position:0% +try taking an infinite number of + + + align:start position:0% +try taking an infinite number of +infinitesimally which makes the CPU sad + + align:start position:0% +infinitesimally which makes the CPU sad + + + align:start position:0% +infinitesimally which makes the CPU sad +and so it's likely to exit with an error + + align:start position:0% +and so it's likely to exit with an error + + + align:start position:0% +and so it's likely to exit with an error +condition generally when that has + + align:start position:0% +condition generally when that has + + + align:start position:0% +condition generally when that has +happened the you you've gotten an answer + + align:start position:0% +happened the you you've gotten an answer + + + align:start position:0% +happened the you you've gotten an answer +that's probably good to within + + align:start position:0% +that's probably good to within + + + align:start position:0% +that's probably good to within +a part in a million or something like + + align:start position:0% +a part in a million or something like + + + align:start position:0% +a part in a million or something like +that fine for our purposes okay if you + + align:start position:0% +that fine for our purposes okay if you + + + align:start position:0% +that fine for our purposes okay if you +need to do something a little bit more + + align:start position:0% +need to do something a little bit more + + + align:start position:0% +need to do something a little bit more +careful you know that's a subject for a + + align:start position:0% +careful you know that's a subject for a + + + align:start position:0% +careful you know that's a subject for a +numerical analysis class for us I will + + align:start position:0% +numerical analysis class for us I will + + + align:start position:0% +numerical analysis class for us I will +give you some hints on this when you + + align:start position:0% +give you some hints on this when you + + + align:start position:0% +give you some hints on this when you +begin exploring these these solutions so + + align:start position:0% +begin exploring these these solutions so + + + align:start position:0% +begin exploring these these solutions so +you have an additional boundary + + align:start position:0% +you have an additional boundary + + + align:start position:0% +you have an additional boundary +condition you know by birkhoff's theorem + + align:start position:0% + + + + align:start position:0% + +that the Schwarzschild metric describes + + align:start position:0% +that the Schwarzschild metric describes + + + align:start position:0% +that the Schwarzschild metric describes +the exterior that means GTT is minus 1 + + align:start position:0% +the exterior that means GTT is minus 1 + + + align:start position:0% +the exterior that means GTT is minus 1 +minus given by this for everywhere + + align:start position:0% +minus given by this for everywhere + + + align:start position:0% +minus given by this for everywhere +greater than R star this gives us a + + align:start position:0% +greater than R star this gives us a + + + align:start position:0% +greater than R star this gives us a +boundary condition that Phi of R star + + align:start position:0% +boundary condition that Phi of R star + + + align:start position:0% +boundary condition that Phi of R star +must be 1/2 log 1 minus 2m total over R + + align:start position:0% +must be 1/2 log 1 minus 2m total over R + + + align:start position:0% +must be 1/2 log 1 minus 2m total over R +star by enforcing this boundary + + align:start position:0% +star by enforcing this boundary + + + align:start position:0% +star by enforcing this boundary +condition you can go back to your + + align:start position:0% +condition you can go back to your + + + align:start position:0% +condition you can go back to your +solution for Phi and you can figure out + + align:start position:0% +solution for Phi and you can figure out + + + align:start position:0% +solution for Phi and you can figure out +what the value at R equals 0 should have + + align:start position:0% +what the value at R equals 0 should have + + + align:start position:0% +what the value at R equals 0 should have +been to give you a continuous function + + align:start position:0% +been to give you a continuous function + + + align:start position:0% +been to give you a continuous function +that matches at this at the surface so + + align:start position:0% +that matches at this at the surface so + + + align:start position:0% +that matches at this at the surface so +that's it for spiracle stars okay this + + align:start position:0% +that's it for spiracle stars okay this + + + align:start position:0% +that's it for spiracle stars okay this +is I look forward to you doing these + + align:start position:0% +is I look forward to you doing these + + + align:start position:0% +is I look forward to you doing these +exercises these are these are actually + + align:start position:0% +exercises these are these are actually + + + align:start position:0% +exercises these are these are actually +playing on my own biases or perhaps + + align:start position:0% +playing on my own biases or perhaps + + + align:start position:0% +playing on my own biases or perhaps +coming out but these are a lot of fun + + align:start position:0% +coming out but these are a lot of fun + + + align:start position:0% +coming out but these are a lot of fun +the one thing which I will do for you + + align:start position:0% +the one thing which I will do for you + + + align:start position:0% +the one thing which I will do for you +and I regret that my notes didn't really + + align:start position:0% +and I regret that my notes didn't really + + + align:start position:0% +and I regret that my notes didn't really +have this is I will try to figure out + + align:start position:0% +have this is I will try to figure out + + + align:start position:0% +have this is I will try to figure out +how on earth I went from line two to + + align:start position:0% +how on earth I went from line two to + + + align:start position:0% +how on earth I went from line two to +line three in this calculation over here + + align:start position:0% +line three in this calculation over here + + + align:start position:0% +line three in this calculation over here +of the B of going from the rest mass + + align:start position:0% +of the B of going from the rest mass + + + align:start position:0% +of the B of going from the rest mass +density the rest energy density to the + + align:start position:0% +density the rest energy density to the + + + align:start position:0% +density the rest energy density to the +energy density my apologies that that's + + align:start position:0% +energy density my apologies that that's + + + align:start position:0% +energy density my apologies that that's +not there all I can say is that there + + align:start position:0% +not there all I can say is that there + + + align:start position:0% +not there all I can say is that there +are many distractions these days and I + + align:start position:0% +are many distractions these days and I + + + align:start position:0% +are many distractions these days and I +overlooked that + + align:start position:0% +overlooked that + + + align:start position:0% +overlooked that +when I was reviewing my notes and + + align:start position:0% +when I was reviewing my notes and + + + align:start position:0% +when I was reviewing my notes and +preparing for today's lectures + + align:start position:0% + + + + align:start position:0% + +I'd like to take this moment take a + + align:start position:0% +I'd like to take this moment take a + + + align:start position:0% +I'd like to take this moment take a +little bit of a detour let's imagine + + align:start position:0% +little bit of a detour let's imagine + + + align:start position:0% +little bit of a detour let's imagine +that we have a space-time that is + + align:start position:0% +that we have a space-time that is + + + align:start position:0% +that we have a space-time that is +schwartz yield everywhere in other words + + align:start position:0% +schwartz yield everywhere in other words + + + align:start position:0% +schwartz yield everywhere in other words +it has this form for all are not simply + + align:start position:0% +it has this form for all are not simply + + + align:start position:0% +it has this form for all are not simply +the exterior of some object okay we + + align:start position:0% +the exterior of some object okay we + + + align:start position:0% +the exterior of some object okay we +already know that this space-time is a + + align:start position:0% +already know that this space-time is a + + + align:start position:0% +already know that this space-time is a +vacuum solution I know that T mu nu + + align:start position:0% +vacuum solution I know that T mu nu + + + align:start position:0% +vacuum solution I know that T mu nu +equals zero so back up for a second if I + + align:start position:0% +equals zero so back up for a second if I + + + align:start position:0% +equals zero so back up for a second if I +generate the Einstein tensor for this I + + align:start position:0% +generate the Einstein tensor for this I + + + align:start position:0% +generate the Einstein tensor for this I +will get identically zero which implies + + align:start position:0% +will get identically zero which implies + + + align:start position:0% +will get identically zero which implies +that this corresponds to a solution + + align:start position:0% +that this corresponds to a solution + + + align:start position:0% +that this corresponds to a solution +which has T mu nu equals zero I also + + align:start position:0% +which has T mu nu equals zero I also + + + align:start position:0% +which has T mu nu equals zero I also +know though that if I examine the + + align:start position:0% +know though that if I examine the + + + align:start position:0% +know though that if I examine the +behavior of radial judy's X in the weak + + align:start position:0% +behavior of radial judy's X in the weak + + + align:start position:0% +behavior of radial judy's X in the weak +field of this space-time + + align:start position:0% + + + + align:start position:0% + +I find that they fall towards this like + + align:start position:0% +I find that they fall towards this like + + + align:start position:0% +I find that they fall towards this like +an object that is falling towards a mass + + align:start position:0% +an object that is falling towards a mass + + + align:start position:0% +an object that is falling towards a mass +M so this space-time appears to be + + align:start position:0% +M so this space-time appears to be + + + align:start position:0% +M so this space-time appears to be +something that is everywhere vacuum + + align:start position:0% +something that is everywhere vacuum + + + align:start position:0% +something that is everywhere vacuum +there is nothing in this space-time and + + align:start position:0% +there is nothing in this space-time and + + + align:start position:0% +there is nothing in this space-time and +that nothing has a mass of M I hope that + + align:start position:0% +that nothing has a mass of M I hope that + + + align:start position:0% +that nothing has a mass of M I hope that +bothers you okay that is among the + + align:start position:0% +bothers you okay that is among the + + + align:start position:0% +bothers you okay that is among the +sillier things that have been said in + + align:start position:0% +sillier things that have been said in + + + align:start position:0% +sillier things that have been said in +the name of physics that sure sounds + + align:start position:0% +the name of physics that sure sounds + + + align:start position:0% +the name of physics that sure sounds +silly but let me remind you that we in + + align:start position:0% +silly but let me remind you that we in + + + align:start position:0% +silly but let me remind you that we in +fact have seen something very similar in + + align:start position:0% +fact have seen something very similar in + + + align:start position:0% +fact have seen something very similar in +a much less complicated theory of + + align:start position:0% +a much less complicated theory of + + + align:start position:0% +a much less complicated theory of +physics + + align:start position:0% + + + + align:start position:0% + +so if I look at the electric field of a + + align:start position:0% +so if I look at the electric field of a + + + align:start position:0% +so if I look at the electric field of a +point charge at the origin so that's the + + align:start position:0% +point charge at the origin so that's the + + + align:start position:0% +point charge at the origin so that's the +three vector e is just Q displacement + + align:start position:0% +three vector e is just Q displacement + + + align:start position:0% +three vector e is just Q displacement +factor over R cubed if I convert if I + + align:start position:0% +factor over R cubed if I convert if I + + + align:start position:0% +factor over R cubed if I convert if I +compute the divergence of this electric + + align:start position:0% +compute the divergence of this electric + + + align:start position:0% +compute the divergence of this electric +field the divergence of course tells me + + align:start position:0% +field the divergence of course tells me + + + align:start position:0% +field the divergence of course tells me +about the charge density and I get zero + + align:start position:0% + + + + align:start position:0% + +so this is an electric field that has no + + align:start position:0% +so this is an electric field that has no + + + align:start position:0% +so this is an electric field that has no +charge density anywhere but that lack of + + align:start position:0% +charge density anywhere but that lack of + + + align:start position:0% +charge density anywhere but that lack of +charge density has a total charge of Q + + align:start position:0% + + + + align:start position:0% + +this was something that we easily learn + + align:start position:0% +this was something that we easily learn + + + align:start position:0% +this was something that we easily learn +how to resolve usually at the MIT + + align:start position:0% +how to resolve usually at the MIT + + + align:start position:0% +how to resolve usually at the MIT +curriculum this often shows up when you + + align:start position:0% +curriculum this often shows up when you + + + align:start position:0% +curriculum this often shows up when you +take a course like 807 what we do is we + + align:start position:0% +take a course like 807 what we do is we + + + align:start position:0% +take a course like 807 what we do is we +say oh all that's going on here is that + + align:start position:0% +say oh all that's going on here is that + + + align:start position:0% +say oh all that's going on here is that +I have a singular point charge at R + + align:start position:0% +I have a singular point charge at R + + + align:start position:0% +I have a singular point charge at R +equals zero so you know yeah I've got no + + align:start position:0% +equals zero so you know yeah I've got no + + + align:start position:0% +equals zero so you know yeah I've got no +charge than C but I have a total charge + + align:start position:0% +charge than C but I have a total charge + + + align:start position:0% +charge than C but I have a total charge +fine we were happy with that I want you + + align:start position:0% +fine we were happy with that I want you + + + align:start position:0% +fine we were happy with that I want you +to think of the Schwarzschild metric as + + align:start position:0% +to think of the Schwarzschild metric as + + + align:start position:0% +to think of the Schwarzschild metric as +doing something similar for gravity okay + + align:start position:0% +doing something similar for gravity okay + + + align:start position:0% +doing something similar for gravity okay +there is no source anywhere but there is + + align:start position:0% +there is no source anywhere but there is + + + align:start position:0% +there is no source anywhere but there is +mass maybe there's just something + + align:start position:0% +mass maybe there's just something + + + align:start position:0% +mass maybe there's just something +singular and a little funny going on at + + align:start position:0% +singular and a little funny going on at + + + align:start position:0% +singular and a little funny going on at +R equals zero might be concerned about + + align:start position:0% +R equals zero might be concerned about + + + align:start position:0% +R equals zero might be concerned about +what's happening there at R equals zero + + align:start position:0% +what's happening there at R equals zero + + + align:start position:0% +what's happening there at R equals zero +and indeed thanks to the sorry when I + + align:start position:0% +and indeed thanks to the sorry when I + + + align:start position:0% +and indeed thanks to the sorry when I +say it plays a similar role plays a + + align:start position:0% +say it plays a similar role plays a + + + align:start position:0% +say it plays a similar role plays a +similar role to the pool cool on point + + align:start position:0% +similar role to the pool cool on point + + + align:start position:0% +similar role to the pool cool on point +charge + + align:start position:0% + + + + align:start position:0% + +okay so there will be nothing there but + + align:start position:0% +okay so there will be nothing there but + + + align:start position:0% +okay so there will be nothing there but +perhaps there's something funny going on + + align:start position:0% +perhaps there's something funny going on + + + align:start position:0% +perhaps there's something funny going on +at R equals zero and by the way is the + + align:start position:0% +at R equals zero and by the way is the + + + align:start position:0% +at R equals zero and by the way is the +field equations that govern gravity my + + align:start position:0% +field equations that govern gravity my + + + align:start position:0% +field equations that govern gravity my +relativistic theory of gravity they're + + align:start position:0% +relativistic theory of gravity they're + + + align:start position:0% +relativistic theory of gravity they're +nonlinear so when I say there's + + align:start position:0% +nonlinear so when I say there's + + + align:start position:0% +nonlinear so when I say there's +something funny going on at article zero + + align:start position:0% +something funny going on at article zero + + + align:start position:0% +something funny going on at article zero +it could be really funny okay so we're + + align:start position:0% +it could be really funny okay so we're + + + align:start position:0% +it could be really funny okay so we're +not gonna get too worked up about that + + align:start position:0% +not gonna get too worked up about that + + + align:start position:0% +not gonna get too worked up about that +but we're just gonna bear in mind you + + align:start position:0% +but we're just gonna bear in mind you + + + align:start position:0% +but we're just gonna bear in mind you +know this is odd team u equals zero but + + align:start position:0% +know this is odd team u equals zero but + + + align:start position:0% +know this is odd team u equals zero but +it has mass so let's look at the + + align:start position:0% +it has mass so let's look at the + + + align:start position:0% +it has mass so let's look at the +space-time itself just staring at this + + align:start position:0% +space-time itself just staring at this + + + align:start position:0% +space-time itself just staring at this +we can see two radii where it appears + + align:start position:0% +we can see two radii where it appears + + + align:start position:0% +we can see two radii where it appears +something odd is going on so you can see + + align:start position:0% +something odd is going on so you can see + + + align:start position:0% +something odd is going on so you can see +right away lots of stuff kind of blows + + align:start position:0% +right away lots of stuff kind of blows + + + align:start position:0% +right away lots of stuff kind of blows +up and behaves badly at R equals zero + + align:start position:0% +up and behaves badly at R equals zero + + + align:start position:0% +up and behaves badly at R equals zero +and you can also see that your GTT and + + align:start position:0% +and you can also see that your GTT and + + + align:start position:0% +and you can also see that your GTT and +your gr are they are behaving in a way + + align:start position:0% +your gr are they are behaving in a way + + + align:start position:0% +your gr are they are behaving in a way +that is potentially problematic when the + + align:start position:0% +that is potentially problematic when the + + + align:start position:0% +that is potentially problematic when the +radius is 2 GM okay so you look at that + + align:start position:0% +radius is 2 GM okay so you look at that + + + align:start position:0% +radius is 2 GM okay so you look at that +and think yeah there's two radii there + + align:start position:0% +and think yeah there's two radii there + + + align:start position:0% +and think yeah there's two radii there +that looks sick I am worried about this + + align:start position:0% +that looks sick I am worried about this + + + align:start position:0% +that looks sick I am worried about this +spacetime well we should be cautious + + align:start position:0% +spacetime well we should be cautious + + + align:start position:0% +spacetime well we should be cautious +okay one of the parables that we learned + + align:start position:0% +okay one of the parables that we learned + + + align:start position:0% +okay one of the parables that we learned +about when we studied linearized gravity + + align:start position:0% +about when we studied linearized gravity + + + align:start position:0% +about when we studied linearized gravity +is that we can sometimes put ourselves + + align:start position:0% +is that we can sometimes put ourselves + + + align:start position:0% +is that we can sometimes put ourselves +into a coordinate system that confuses + + align:start position:0% +into a coordinate system that confuses + + + align:start position:0% +into a coordinate system that confuses +us okay when we stayed linearized + + align:start position:0% +us okay when we stayed linearized + + + align:start position:0% +us okay when we stayed linearized +gravity we found a solution that looked + + align:start position:0% +gravity we found a solution that looked + + + align:start position:0% +gravity we found a solution that looked +everywhere it looked like the entire + + align:start position:0% +everywhere it looked like the entire + + + align:start position:0% +everywhere it looked like the entire +space-time metric was radiative and it + + align:start position:0% +space-time metric was radiative and it + + + align:start position:0% +space-time metric was radiative and it +turned out only two of those ten + + align:start position:0% +turned out only two of those ten + + + align:start position:0% +turned out only two of those ten +compliments were radiative that turned + + align:start position:0% +compliments were radiative that turned + + + align:start position:0% +compliments were radiative that turned +out to be something that we were able to + + align:start position:0% +out to be something that we were able to + + + align:start position:0% +out to be something that we were able to +cure by introducing engaged + + align:start position:0% +cure by introducing engaged + + + align:start position:0% +cure by introducing engaged +transformation doing that here is a + + align:start position:0% +transformation doing that here is a + + + align:start position:0% +transformation doing that here is a +little bit trickier but we're gonna need + + align:start position:0% +little bit trickier but we're gonna need + + + align:start position:0% +little bit trickier but we're gonna need +to think about how can i how can i more + + align:start position:0% +to think about how can i how can i more + + + align:start position:0% +to think about how can i how can i more +clearly call out the physical content of + + align:start position:0% +clearly call out the physical content of + + + align:start position:0% +clearly call out the physical content of +this space-time so one thing that one of + + align:start position:0% +this space-time so one thing that one of + + + align:start position:0% +this space-time so one thing that one of +the lessons that I hope has been + + align:start position:0% +the lessons that I hope has been + + + align:start position:0% +the lessons that I hope has been +imparted in this class so far is that if + + align:start position:0% +imparted in this class so far is that if + + + align:start position:0% +imparted in this class so far is that if +you really want understand the nature of + + align:start position:0% +you really want understand the nature of + + + align:start position:0% +you really want understand the nature of +gravity you want to go from the metric + + align:start position:0% +gravity you want to go from the metric + + + align:start position:0% +gravity you want to go from the metric +to the + + align:start position:0% +to the + + + align:start position:0% +to the +curvature so what I'm gonna do is + + align:start position:0% +curvature so what I'm gonna do is + + + align:start position:0% +curvature so what I'm gonna do is +assemble a in an invariant scaler from + + align:start position:0% +assemble a in an invariant scaler from + + + align:start position:0% +assemble a in an invariant scaler from +my curvature and I'm gonna use the + + align:start position:0% +my curvature and I'm gonna use the + + + align:start position:0% +my curvature and I'm gonna use the +Riemann tensor because I know + + align:start position:0% +Riemann tensor because I know + + + align:start position:0% +Riemann tensor because I know +Ricci vanishes in this space-time so + + align:start position:0% +Ricci vanishes in this space-time so + + + align:start position:0% +Ricci vanishes in this space-time so +that wouldn't give me anything + + align:start position:0% +that wouldn't give me anything + + + align:start position:0% +that wouldn't give me anything +interesting so what I'm going to do is + + align:start position:0% +interesting so what I'm going to do is + + + align:start position:0% +interesting so what I'm going to do is +assemble an object I'm gonna call it + + align:start position:0% +assemble an object I'm gonna call it + + + align:start position:0% +assemble an object I'm gonna call it +capital I and that's just Riemann + + align:start position:0% +capital I and that's just Riemann + + + align:start position:0% +capital I and that's just Riemann +contract it into cream on this actually + + align:start position:0% +contract it into cream on this actually + + + align:start position:0% +contract it into cream on this actually +has a name it is known as the crutch + + align:start position:0% +has a name it is known as the crutch + + + align:start position:0% +has a name it is known as the crutch +Monde scaler and you know you can go in + + align:start position:0% +Monde scaler and you know you can go in + + + align:start position:0% +Monde scaler and you know you can go in +you can work out all these components + + align:start position:0% +you can work out all these components + + + align:start position:0% +you can work out all these components +the ER tool that is posted to the eight + + align:start position:0% +the ER tool that is posted to the eight + + + align:start position:0% +the ER tool that is posted to the eight +962 website something you can own you + + align:start position:0% +962 website something you can own you + + + align:start position:0% +962 website something you can own you +can you can explore with this and this + + align:start position:0% +can you can explore with this and this + + + align:start position:0% +can you can explore with this and this +is just a number turns out to be 48 G + + align:start position:0% +is just a number turns out to be 48 G + + + align:start position:0% +is just a number turns out to be 48 G +squared M squared over R to the sixth + + align:start position:0% +squared M squared over R to the sixth + + + align:start position:0% +squared M squared over R to the sixth +what does this guy mean well you know + + align:start position:0% +what does this guy mean well you know + + + align:start position:0% +what does this guy mean well you know +this is basically it's in a sort of an + + align:start position:0% +this is basically it's in a sort of an + + + align:start position:0% +this is basically it's in a sort of an +invariant way it's kind of riemann + + align:start position:0% +invariant way it's kind of riemann + + + align:start position:0% +invariant way it's kind of riemann +squared riemann tells me about if you go + + align:start position:0% +squared riemann tells me about if you go + + + align:start position:0% +squared riemann tells me about if you go +back and think about things like judie + + align:start position:0% +back and think about things like judie + + + align:start position:0% +back and think about things like judie +tzuke deviation it tells me about the + + align:start position:0% +tzuke deviation it tells me about the + + + align:start position:0% +tzuke deviation it tells me about the +strength of tides so roughly speaking + + align:start position:0% +strength of tides so roughly speaking + + + align:start position:0% +strength of tides so roughly speaking +square root i is an invariant way of + + align:start position:0% +square root i is an invariant way of + + + align:start position:0% +square root i is an invariant way of +characterizing tidal forces + + align:start position:0% + + + + align:start position:0% + +so if you're stepping around in the + + align:start position:0% +so if you're stepping around in the + + + align:start position:0% +so if you're stepping around in the +Swart shield space time and you want to + + align:start position:0% +Swart shield space time and you want to + + + align:start position:0% +Swart shield space time and you want to +give yourself an estimate of what kind + + align:start position:0% +give yourself an estimate of what kind + + + align:start position:0% +give yourself an estimate of what kind +of tidal forces are likely to act on you + + align:start position:0% +of tidal forces are likely to act on you + + + align:start position:0% +of tidal forces are likely to act on you +compute the crutch Mon scalar take its + + align:start position:0% +compute the crutch Mon scalar take its + + + align:start position:0% +compute the crutch Mon scalar take its +square root and that'll give you an idea + + align:start position:0% +square root and that'll give you an idea + + + align:start position:0% +square root and that'll give you an idea +of how strong they typically tend to be + + align:start position:0% + + + + align:start position:0% + +so notice when we look at this this + + align:start position:0% +so notice when we look at this this + + + align:start position:0% +so notice when we look at this this +tells us our equals to GM if you plug R + + align:start position:0% +tells us our equals to GM if you plug R + + + align:start position:0% +tells us our equals to GM if you plug R +equals two GM in there you know nothing + + align:start position:0% +equals two GM in there you know nothing + + + align:start position:0% +equals two GM in there you know nothing +special about it okay it's a radius just + + align:start position:0% +special about it okay it's a radius just + + + align:start position:0% +special about it okay it's a radius just +like any other as you go from two point + + align:start position:0% +like any other as you go from two point + + + align:start position:0% +like any other as you go from two point +zero zero zero one GM to one point nine + + align:start position:0% +zero zero zero one GM to one point nine + + + align:start position:0% +zero zero zero one GM to one point nine +nine nine nine nine GM it increases a + + align:start position:0% +nine nine nine nine GM it increases a + + + align:start position:0% +nine nine nine nine GM it increases a +little bit you know of course it's got + + align:start position:0% +little bit you know of course it's got + + + align:start position:0% +little bit you know of course it's got +the 1 over R to the six behavior but + + align:start position:0% +the 1 over R to the six behavior but + + + align:start position:0% +the 1 over R to the six behavior but +it's not like there's a sudden + + align:start position:0% +it's not like there's a sudden + + + align:start position:0% +it's not like there's a sudden +transition or anything particularly + + align:start position:0% +transition or anything particularly + + + align:start position:0% +transition or anything particularly +special happens right at that radius but + + align:start position:0% +special happens right at that radius but + + + align:start position:0% +special happens right at that radius but +it is hello + + align:start position:0% +it is hello + + + align:start position:0% +it is hello +singular at R equals zero so sure enough + + align:start position:0% +singular at R equals zero so sure enough + + + align:start position:0% +singular at R equals zero so sure enough +R equals zero is a place where tidal + + align:start position:0% +R equals zero is a place where tidal + + + align:start position:0% +R equals zero is a place where tidal +forces blow up okay + + align:start position:0% + + + + align:start position:0% + +okay fine we're gonna need to do a + + align:start position:0% +okay fine we're gonna need to do a + + + align:start position:0% +okay fine we're gonna need to do a +little bit more work then because I + + align:start position:0% +little bit more work then because I + + + align:start position:0% +little bit more work then because I +still want to understand yeah okay + + align:start position:0% +still want to understand yeah okay + + + align:start position:0% +still want to understand yeah okay +our equals 2 GM there's no diverging + + align:start position:0% +our equals 2 GM there's no diverging + + + align:start position:0% +our equals 2 GM there's no diverging +tidal forces there but that metric still + + align:start position:0% +tidal forces there but that metric still + + + align:start position:0% +tidal forces there but that metric still +looks wacky at that point so what is + + align:start position:0% +looks wacky at that point so what is + + + align:start position:0% +looks wacky at that point so what is +going on there so let's think about the + + align:start position:0% +going on there so let's think about the + + + align:start position:0% +going on there so let's think about the +geometry of the space-time in the + + align:start position:0% +geometry of the space-time in the + + + align:start position:0% +geometry of the space-time in the +vicinity of 2 GM so let's imagine let's + + align:start position:0% +vicinity of 2 GM so let's imagine let's + + + align:start position:0% +vicinity of 2 GM so let's imagine let's +do the following exercise suppose I draw + + align:start position:0% +do the following exercise suppose I draw + + + align:start position:0% +do the following exercise suppose I draw +a circle at some radius R that's in the + + align:start position:0% +a circle at some radius R that's in the + + + align:start position:0% +a circle at some radius R that's in the +theta equals PI over 2 plane ok so I'm + + align:start position:0% +theta equals PI over 2 plane ok so I'm + + + align:start position:0% +theta equals PI over 2 plane ok so I'm +just sort of sweeping around in Phi I'm + + align:start position:0% +just sort of sweeping around in Phi I'm + + + align:start position:0% +just sort of sweeping around in Phi I'm +making this like so so here is my R + + align:start position:0% +making this like so so here is my R + + + align:start position:0% +making this like so so here is my R +cosine Phi axis here is my R sine Phi + + align:start position:0% +cosine Phi axis here is my R sine Phi + + + align:start position:0% +cosine Phi axis here is my R sine Phi +axis here is my circle of radius R and + + align:start position:0% +axis here is my circle of radius R and + + + align:start position:0% +axis here is my circle of radius R and +let's ask what is the surface area that + + align:start position:0% +let's ask what is the surface area that + + + align:start position:0% +let's ask what is the surface area that +this guy sweeps out as an advanced + + align:start position:0% +this guy sweeps out as an advanced + + + align:start position:0% +this guy sweeps out as an advanced +forward in time so this thing goes for + + align:start position:0% +forward in time so this thing goes for + + + align:start position:0% +forward in time so this thing goes for +it in time + + align:start position:0% +it in time + + + align:start position:0% +it in time +it sort of sweeps out a cylinder in a + + align:start position:0% +it sort of sweeps out a cylinder in a + + + align:start position:0% +it sort of sweeps out a cylinder in a +spacetime diagram let's compute the + + align:start position:0% +spacetime diagram let's compute the + + + align:start position:0% +spacetime diagram let's compute the +proper area associated with this + + align:start position:0% +proper area associated with this + + + align:start position:0% +proper area associated with this +cylinder that this circle is sweeping + + align:start position:0% +cylinder that this circle is sweeping + + + align:start position:0% +cylinder that this circle is sweeping +out as it moves forward in time so the + + align:start position:0% +out as it moves forward in time so the + + + align:start position:0% +out as it moves forward in time so the +surface area of my tube it's gonna be I + + align:start position:0% +surface area of my tube it's gonna be I + + + align:start position:0% +surface area of my tube it's gonna be I +integrate from some start time to some + + align:start position:0% +integrate from some start time to some + + + align:start position:0% +integrate from some start time to some +end time + + align:start position:0% + + + + align:start position:0% + +I'm gonna integrate around in Phi and + + align:start position:0% +I'm gonna integrate around in Phi and + + + align:start position:0% +I'm gonna integrate around in Phi and +then the proper area element that I need + + align:start position:0% +then the proper area element that I need + + + align:start position:0% +then the proper area element that I need +to do this is going to be GT t g5 v the + + align:start position:0% +to do this is going to be GT t g5 v the + + + align:start position:0% +to do this is going to be GT t g5 v the +1/2 okay minus sign in there to get the + + align:start position:0% +1/2 okay minus sign in there to get the + + + align:start position:0% +1/2 okay minus sign in there to get the +sign right that's right like this okay + + align:start position:0% +sign right that's right like this okay + + + align:start position:0% +sign right that's right like this okay +so remind you how I do this think of + + align:start position:0% +so remind you how I do this think of + + + align:start position:0% +so remind you how I do this think of +this area element as a two-volume go + + align:start position:0% +this area element as a two-volume go + + + align:start position:0% +this area element as a two-volume go +back to some of our earlier discussion + + align:start position:0% +back to some of our earlier discussion + + + align:start position:0% +back to some of our earlier discussion +of defining integrals in space-time and + + align:start position:0% +of defining integrals in space-time and + + + align:start position:0% +of defining integrals in space-time and +this is the proper area associated with + + align:start position:0% +this is the proper area associated with + + + align:start position:0% +this is the proper area associated with +a figure that has some extent in time an + + align:start position:0% +a figure that has some extent in time an + + + align:start position:0% +a figure that has some extent in time an +extent in angle okay + + align:start position:0% +extent in angle okay + + + align:start position:0% +extent in angle okay +so let's compute that guy + + align:start position:0% + + + + align:start position:0% + +so I take my Schwarzschild metric g55 in + + align:start position:0% +so I take my Schwarzschild metric g55 in + + + align:start position:0% +so I take my Schwarzschild metric g55 in +the theta equals PI over 2 plane is just + + align:start position:0% +the theta equals PI over 2 plane is just + + + align:start position:0% +the theta equals PI over 2 plane is just +our GT T is the square root of 1 minus 2 + + align:start position:0% +our GT T is the square root of 1 minus 2 + + + align:start position:0% +our GT T is the square root of 1 minus 2 +GM over R so the area of my tube is + + align:start position:0% +GM over R so the area of my tube is + + + align:start position:0% +GM over R so the area of my tube is +going to be R whoops integrate from my + + align:start position:0% +going to be R whoops integrate from my + + + align:start position:0% +going to be R whoops integrate from my +start time to my end time DT so this is + + align:start position:0% +start time to my end time DT so this is + + + align:start position:0% +start time to my end time DT so this is +easy so I get a 2 pi 2 pi r square root + + align:start position:0% +easy so I get a 2 pi 2 pi r square root + + + align:start position:0% +easy so I get a 2 pi 2 pi r square root +1 minus 2 GM over R and let's just say + + align:start position:0% +1 minus 2 GM over R and let's just say + + + align:start position:0% +1 minus 2 GM over R and let's just say +mic interval is delta T notice what + + align:start position:0% +mic interval is delta T notice what + + + align:start position:0% +mic interval is delta T notice what +happens as I take the radius as this + + align:start position:0% +happens as I take the radius as this + + + align:start position:0% +happens as I take the radius as this +thing down to 2 GM this goes to 0 as R + + align:start position:0% +thing down to 2 GM this goes to 0 as R + + + align:start position:0% +thing down to 2 GM this goes to 0 as R +goes to 2 GM if I go inside to GM how do + + align:start position:0% +goes to 2 GM if I go inside to GM how do + + + align:start position:0% +goes to 2 GM if I go inside to GM how do +you want to compute that ok something + + align:start position:0% +you want to compute that ok something + + + align:start position:0% +you want to compute that ok something +has gone awry but look I can draw this + + align:start position:0% +has gone awry but look I can draw this + + + align:start position:0% +has gone awry but look I can draw this +thing just fine right clearly there's a + + align:start position:0% +thing just fine right clearly there's a + + + align:start position:0% +thing just fine right clearly there's a +surface there right it's got to have an + + align:start position:0% +surface there right it's got to have an + + + align:start position:0% +surface there right it's got to have an +area associated with it why are you + + align:start position:0% +area associated with it why are you + + + align:start position:0% +area associated with it why are you +telling me that the area of this thing + + align:start position:0% +telling me that the area of this thing + + + align:start position:0% +telling me that the area of this thing +is zero in that limit and is a nonsense + + align:start position:0% +is zero in that limit and is a nonsense + + + align:start position:0% +is zero in that limit and is a nonsense +integral if I go inside this thing well + + align:start position:0% +integral if I go inside this thing well + + + align:start position:0% +integral if I go inside this thing well +what's happening is we have uncovered a + + align:start position:0% +what's happening is we have uncovered a + + + align:start position:0% +what's happening is we have uncovered a +coordinate singularity the time + + align:start position:0% +coordinate singularity the time + + + align:start position:0% +coordinate singularity the time +coordinate is badly behaved + + align:start position:0% + + + + align:start position:0% + +as we not well as we approach this + + align:start position:0% +as we not well as we approach this + + + align:start position:0% +as we not well as we approach this +radius R equals 2 GM let me give you an + + align:start position:0% +radius R equals 2 GM let me give you an + + + align:start position:0% +radius R equals 2 GM let me give you an +analogy that describes essentially what + + align:start position:0% +analogy that describes essentially what + + + align:start position:0% +analogy that describes essentially what +that it's something that is very similar + + align:start position:0% + + + + align:start position:0% + +to that tube that world tube that I just + + align:start position:0% +to that tube that world tube that I just + + + align:start position:0% +to that tube that world tube that I just +drew but let me do it in a perhaps more + + align:start position:0% +drew but let me do it in a perhaps more + + + align:start position:0% +drew but let me do it in a perhaps more +familiar context suppose I want to draw + + align:start position:0% +familiar context suppose I want to draw + + + align:start position:0% +familiar context suppose I want to draw +a sphere and all that I know about a + + align:start position:0% +a sphere and all that I know about a + + + align:start position:0% +a sphere and all that I know about a +sphere is that it has got two + + align:start position:0% +sphere is that it has got two + + + align:start position:0% +sphere is that it has got two +coordinates to cover it in angle Phi and + + align:start position:0% +coordinates to cover it in angle Phi and + + + align:start position:0% +coordinates to cover it in angle Phi and +an angle theta and so I could say okay + + align:start position:0% + + + + align:start position:0% + +here is my sphere + + align:start position:0% + + + + align:start position:0% + +okay here is theta equals zero Phi + + align:start position:0% +okay here is theta equals zero Phi + + + align:start position:0% +okay here is theta equals zero Phi +equals zero it is Phi equals PI over two + + align:start position:0% +equals zero it is Phi equals PI over two + + + align:start position:0% +equals zero it is Phi equals PI over two +here's Phi equals PI Phi equals 3 PI + + align:start position:0% +here's Phi equals PI Phi equals 3 PI + + + align:start position:0% +here's Phi equals PI Phi equals 3 PI +over 2 Phi equals 2 pi state equals PI + + align:start position:0% +over 2 Phi equals 2 pi state equals PI + + + align:start position:0% +over 2 Phi equals 2 pi state equals PI +over 2 equals pi + + align:start position:0% + + + + align:start position:0% + +there's my sphere so this chart that + + align:start position:0% +there's my sphere so this chart that + + + align:start position:0% +there's my sphere so this chart that +I've just drawn here this actually you + + align:start position:0% +I've just drawn here this actually you + + + align:start position:0% +I've just drawn here this actually you +know it's it's it's true this does + + align:start position:0% +know it's it's it's true this does + + + align:start position:0% +know it's it's it's true this does +represent the coordinate system but it's + + align:start position:0% +represent the coordinate system but it's + + + align:start position:0% +represent the coordinate system but it's +a horrible rendering of a spheres + + align:start position:0% +a horrible rendering of a spheres + + + align:start position:0% +a horrible rendering of a spheres +geometry what I didn't realize when I + + align:start position:0% +geometry what I didn't realize when I + + + align:start position:0% +geometry what I didn't realize when I +wrote this down here is that in fact at + + align:start position:0% +wrote this down here is that in fact at + + + align:start position:0% +wrote this down here is that in fact at +theta equals 0 and theta equals PI every + + align:start position:0% +theta equals 0 and theta equals PI every + + + align:start position:0% +theta equals 0 and theta equals PI every +5 value should be collapsed to a single + + align:start position:0% +5 value should be collapsed to a single + + + align:start position:0% +5 value should be collapsed to a single +point + + align:start position:0% + + + + align:start position:0% + +okay this is reflecting the fact that if + + align:start position:0% +okay this is reflecting the fact that if + + + align:start position:0% +okay this is reflecting the fact that if +you look at the look at a globe all + + align:start position:0% +you look at the look at a globe all + + + align:start position:0% +you look at the look at a globe all +lines of longitude cross at the North + + align:start position:0% +lines of longitude cross at the North + + + align:start position:0% +lines of longitude cross at the North +Pole on the South Pole every value of + + align:start position:0% +Pole on the South Pole every value of + + + align:start position:0% +Pole on the South Pole every value of +the eight the azimuthal angle on the + + align:start position:0% +the eight the azimuthal angle on the + + + align:start position:0% +the eight the azimuthal angle on the +surface of the earth they become + + align:start position:0% +surface of the earth they become + + + align:start position:0% +surface of the earth they become +singular at the North Pole on the South + + align:start position:0% +singular at the North Pole on the South + + + align:start position:0% +singular at the North Pole on the South +Pole this drawing is like well it's like + + align:start position:0% +Pole this drawing is like well it's like + + + align:start position:0% +Pole this drawing is like well it's like +one of those I forget the names of them + + align:start position:0% +one of those I forget the names of them + + + align:start position:0% +one of those I forget the names of them +but the various renderings of a map that + + align:start position:0% +but the various renderings of a map that + + + align:start position:0% +but the various renderings of a map that +try to take the earth and write it on a + + align:start position:0% +try to take the earth and write it on a + + + align:start position:0% +try to take the earth and write it on a +flat space and you know you wind up with + + align:start position:0% +flat space and you know you wind up with + + + align:start position:0% +flat space and you know you wind up with +Greenland being three times the size of + + align:start position:0% +Greenland being three times the size of + + + align:start position:0% +Greenland being three times the size of +Africa or something like that and it's + + align:start position:0% +Africa or something like that and it's + + + align:start position:0% +Africa or something like that and it's +because there should be zero area at the + + align:start position:0% +because there should be zero area at the + + + align:start position:0% +because there should be zero area at the +top here as you approach the top the + + align:start position:0% +top here as you approach the top the + + + align:start position:0% +top here as you approach the top the +area should be getting much stronger + + align:start position:0% +area should be getting much stronger + + + align:start position:0% +area should be getting much stronger +when you do a representation of your map + + align:start position:0% +when you do a representation of your map + + + align:start position:0% +when you do a representation of your map +like this you're spreading this + + align:start position:0% +like this you're spreading this + + + align:start position:0% +like this you're spreading this +everything way way out what is going on + + align:start position:0% +everything way way out what is going on + + + align:start position:0% +everything way way out what is going on +and why this idea of drawing this world + + align:start position:0% +and why this idea of drawing this world + + + align:start position:0% +and why this idea of drawing this world +tube that is swept out by my my circle + + align:start position:0% +tube that is swept out by my my circle + + + align:start position:0% +tube that is swept out by my my circle +of radius R as it advances forward in + + align:start position:0% +of radius R as it advances forward in + + + align:start position:0% +of radius R as it advances forward in +time it has not taken into account the + + align:start position:0% +time it has not taken into account the + + + align:start position:0% +time it has not taken into account the +fact that drawing does not account for + + align:start position:0% +fact that drawing does not account for + + + align:start position:0% +fact that drawing does not account for +the fact that the Swart shield time + + align:start position:0% +the fact that the Swart shield time + + + align:start position:0% +the fact that the Swart shield time +coordinate is singular + + align:start position:0% +coordinate is singular + + + align:start position:0% +coordinate is singular +as you approach R equals to GM it's + + align:start position:0% +as you approach R equals to GM it's + + + align:start position:0% +as you approach R equals to GM it's +going to turn out all times T map to a + + align:start position:0% +going to turn out all times T map to a + + + align:start position:0% +going to turn out all times T map to a +single sphere at R equals to GM to get + + align:start position:0% +single sphere at R equals to GM to get + + + align:start position:0% +single sphere at R equals to GM to get +some insight into what's going on here + + align:start position:0% +some insight into what's going on here + + + align:start position:0% +some insight into what's going on here +let's do a little thought experiment + + align:start position:0% + + + + align:start position:0% + +what I'm going to do is imagine I'm at + + align:start position:0% +what I'm going to do is imagine I'm at + + + align:start position:0% +what I'm going to do is imagine I'm at +rest in the Swart shield space-time okay + + align:start position:0% +rest in the Swart shield space-time okay + + + align:start position:0% +rest in the Swart shield space-time okay +so let's say that I met some finite + + align:start position:0% +so let's say that I met some finite + + + align:start position:0% +so let's say that I met some finite +radius R I am NOT in the weak field okay + + align:start position:0% +radius R I am NOT in the weak field okay + + + align:start position:0% +radius R I am NOT in the weak field okay +maybe I am at something like R equals + + align:start position:0% +maybe I am at something like R equals + + + align:start position:0% +maybe I am at something like R equals +four GM or something like that and what + + align:start position:0% +four GM or something like that and what + + + align:start position:0% +four GM or something like that and what +I'm going to do is drop a little rock + + align:start position:0% +I'm going to do is drop a little rock + + + align:start position:0% +I'm going to do is drop a little rock +drop a particle so I'm going to drop a + + align:start position:0% +drop a particle so I'm going to drop a + + + align:start position:0% +drop a particle so I'm going to drop a +particle from R equals r0 I am going to + + align:start position:0% +particle from R equals r0 I am going to + + + align:start position:0% +particle from R equals r0 I am going to +integrate the judy's equation and I'm + + align:start position:0% +integrate the judy's equation and I'm + + + align:start position:0% +integrate the judy's equation and I'm +going to parameterize what its radial + + align:start position:0% +going to parameterize what its radial + + + align:start position:0% +going to parameterize what its radial +motion looks like as a function of time + + align:start position:0% +motion looks like as a function of time + + + align:start position:0% +motion looks like as a function of time +I put time in quotes here because you + + align:start position:0% +I put time in quotes here because you + + + align:start position:0% +I put time in quotes here because you +should be saying at this point well you + + align:start position:0% +should be saying at this point well you + + + align:start position:0% +should be saying at this point well you +just told me that time is doing + + align:start position:0% +just told me that time is doing + + + align:start position:0% +just told me that time is doing +something kind of funny here what do you + + align:start position:0% +something kind of funny here what do you + + + align:start position:0% +something kind of funny here what do you +mean by that I'm actually going to do + + align:start position:0% +mean by that I'm actually going to do + + + align:start position:0% +mean by that I'm actually going to do +this for two different notions of time + + align:start position:0% + + + + align:start position:0% + +I'm going to do this for the coordinate + + align:start position:0% +I'm going to do this for the coordinate + + + align:start position:0% +I'm going to do this for the coordinate +time T and I'm also going to do this for + + align:start position:0% +time T and I'm also going to do this for + + + align:start position:0% +time T and I'm also going to do this for +proper time tau + + align:start position:0% + + + + align:start position:0% + +as measured along that world that info + + align:start position:0% +as measured along that world that info + + + align:start position:0% +as measured along that world that info +[Applause] + + align:start position:0% + + + + align:start position:0% + +okay so I'm not going to go through the + + align:start position:0% +okay so I'm not going to go through the + + + align:start position:0% +okay so I'm not going to go through the +details of this calculation it's a + + align:start position:0% +details of this calculation it's a + + + align:start position:0% +details of this calculation it's a +straightforward + + align:start position:0% +straightforward + + + align:start position:0% +straightforward +moderately tedious exercise I will just + + align:start position:0% +moderately tedious exercise I will just + + + align:start position:0% +moderately tedious exercise I will just +quote to you what the result ends up + + align:start position:0% +quote to you what the result ends up + + + align:start position:0% +quote to you what the result ends up +looking + + align:start position:0% +looking + + + align:start position:0% +looking +[Applause] + + align:start position:0% + + + + align:start position:0% + +so let's first write down what the + + align:start position:0% +so let's first write down what the + + + align:start position:0% +so let's first write down what the +solution looks like parameterize by the + + align:start position:0% +solution looks like parameterize by the + + + align:start position:0% +solution looks like parameterize by the +proper time so this is most easily + + align:start position:0% +proper time so this is most easily + + + align:start position:0% +proper time so this is most easily +written as tau proper time and 2 g-m + + align:start position:0% +written as tau proper time and 2 g-m + + + align:start position:0% +written as tau proper time and 2 g-m +essentially I'm just gonna use it to set + + align:start position:0% +essentially I'm just gonna use it to set + + + align:start position:0% +essentially I'm just gonna use it to set +a system of units I write this thing as + + align:start position:0% +a system of units I write this thing as + + + align:start position:0% +a system of units I write this thing as +a function of R my solution turns out to + + align:start position:0% +a function of R my solution turns out to + + + align:start position:0% +a function of R my solution turns out to +be looks like this so if I were to make + + align:start position:0% +be looks like this so if I were to make + + + align:start position:0% +be looks like this so if I were to make +a plot of what this thing's motion looks + + align:start position:0% +a plot of what this thing's motion looks + + + align:start position:0% +a plot of what this thing's motion looks +like as a function of time so here's our + + align:start position:0% +like as a function of time so here's our + + + align:start position:0% +like as a function of time so here's our +0 here is R of tau and let's just put in + + align:start position:0% +0 here is R of tau and let's just put in + + + align:start position:0% +0 here is R of tau and let's just put in +for fun let's say this is 2 g-m fall in + + align:start position:0% +for fun let's say this is 2 g-m fall in + + + align:start position:0% +for fun let's say this is 2 g-m fall in +you reach R equals 0 in finite proper + + align:start position:0% +you reach R equals 0 in finite proper + + + align:start position:0% +you reach R equals 0 in finite proper +time it's the parable of the crutch mind + + align:start position:0% +time it's the parable of the crutch mind + + + align:start position:0% +time it's the parable of the crutch mind +scaler is that as you do so the tidal + + align:start position:0% +scaler is that as you do so the tidal + + + align:start position:0% +scaler is that as you do so the tidal +forces acting on you are diverging so if + + align:start position:0% +forces acting on you are diverging so if + + + align:start position:0% +forces acting on you are diverging so if +you have any last wishes send them out + + align:start position:0% +you have any last wishes send them out + + + align:start position:0% +you have any last wishes send them out +because you're not gonna have a lot of + + align:start position:0% +because you're not gonna have a lot of + + + align:start position:0% +because you're not gonna have a lot of +time to to tell people about them let's + + align:start position:0% +time to to tell people about them let's + + + align:start position:0% +time to to tell people about them let's +now write it as a function of coordinate + + align:start position:0% +now write it as a function of coordinate + + + align:start position:0% +now write it as a function of coordinate +time T this ends up being bear with me + + align:start position:0% +time T this ends up being bear with me + + + align:start position:0% +time T this ends up being bear with me +while I write this out this is slightly + + align:start position:0% +while I write this out this is slightly + + + align:start position:0% +while I write this out this is slightly +lengthing + + align:start position:0% + + + + align:start position:0% + +okay so what I mean on this last line is + + align:start position:0% +okay so what I mean on this last line is + + + align:start position:0% +okay so what I mean on this last line is +if you want to give the complete + + align:start position:0% +if you want to give the complete + + + align:start position:0% +if you want to give the complete +solution just write both of these + + align:start position:0% +solution just write both of these + + + align:start position:0% +solution just write both of these +functions down again subtract them off + + align:start position:0% +functions down again subtract them off + + + align:start position:0% +functions down again subtract them off +replace the ours with our zero when you + + align:start position:0% +replace the ours with our zero when you + + + align:start position:0% +replace the ours with our zero when you +look at this + + align:start position:0% + + + + align:start position:0% + +here's what you see the motion expressed + + align:start position:0% +here's what you see the motion expressed + + + align:start position:0% +here's what you see the motion expressed +in times of the coordinate time T + + align:start position:0% +in times of the coordinate time T + + + align:start position:0% +in times of the coordinate time T +asymptotically approaches the radius to + + align:start position:0% +asymptotically approaches the radius to + + + align:start position:0% +asymptotically approaches the radius to +GM but it never quite reaches it as T + + align:start position:0% +GM but it never quite reaches it as T + + + align:start position:0% +GM but it never quite reaches it as T +goes to infinity it eventually reaches + + align:start position:0% +goes to infinity it eventually reaches + + + align:start position:0% +goes to infinity it eventually reaches +so are you can sort of see it appearing + + align:start position:0% +so are you can sort of see it appearing + + + align:start position:0% +so are you can sort of see it appearing +in the behavior this natural log R gets + + align:start position:0% +in the behavior this natural log R gets + + + align:start position:0% +in the behavior this natural log R gets +to 2 GM as T goes to infinity so as + + align:start position:0% +to 2 GM as T goes to infinity so as + + + align:start position:0% +to 2 GM as T goes to infinity so as +measured by clocks on the infalling body + + align:start position:0% +measured by clocks on the infalling body + + + align:start position:0% +measured by clocks on the infalling body +it rapidly reaches R equals 0 according + + align:start position:0% +it rapidly reaches R equals 0 according + + + align:start position:0% +it rapidly reaches R equals 0 according +this coordinate time it never even + + align:start position:0% +this coordinate time it never even + + + align:start position:0% +this coordinate time it never even +crosses R equals to GM what the hell is + + align:start position:0% +crosses R equals to GM what the hell is + + + align:start position:0% +crosses R equals to GM what the hell is +going on with that well to keep a little + + align:start position:0% +going on with that well to keep a little + + + align:start position:0% +going on with that well to keep a little +bit of insight into this it's useful to + + align:start position:0% +bit of insight into this it's useful to + + + align:start position:0% +bit of insight into this it's useful to +think it's useful to stop for a second + + align:start position:0% +think it's useful to stop for a second + + + align:start position:0% +think it's useful to stop for a second +and ask ourselves what is that + + align:start position:0% +and ask ourselves what is that + + + align:start position:0% +and ask ourselves what is that +coordinate time T actually measuring so + + align:start position:0% +coordinate time T actually measuring so + + + align:start position:0% +coordinate time T actually measuring so +let me write down the Schwarzschild + + align:start position:0% +let me write down the Schwarzschild + + + align:start position:0% +let me write down the Schwarzschild +metric now let's think about this + + align:start position:0% + + + + align:start position:0% + +so it's kind of hard to see what T means + + align:start position:0% +so it's kind of hard to see what T means + + + align:start position:0% +so it's kind of hard to see what T means +in this but let's consider a lemon + + align:start position:0% +in this but let's consider a lemon + + + align:start position:0% +in this but let's consider a lemon +suppose I consider observers who are + + align:start position:0% +suppose I consider observers who are + + + align:start position:0% +suppose I consider observers who are +very far away if I look at people who + + align:start position:0% +very far away if I look at people who + + + align:start position:0% +very far away if I look at people who +are at our much much larger than to GM + + align:start position:0% + + + + align:start position:0% + +for such observers space time looks like + + align:start position:0% +for such observers space time looks like + + + align:start position:0% +for such observers space time looks like +this and this is nothing more than flat + + align:start position:0% +this and this is nothing more than flat + + + align:start position:0% +this and this is nothing more than flat +space-time in spherical coordinates this + + align:start position:0% +space-time in spherical coordinates this + + + align:start position:0% +space-time in spherical coordinates this +is what we call an asymptotically flat + + align:start position:0% +is what we call an asymptotically flat + + + align:start position:0% +is what we call an asymptotically flat +space-time as you get sufficiently far + + align:start position:0% +space-time as you get sufficiently far + + + align:start position:0% +space-time as you get sufficiently far +away from the source it looks just like + + align:start position:0% +away from the source it looks just like + + + align:start position:0% +away from the source it looks just like +flat space-time we can use essentially + + align:start position:0% +flat space-time we can use essentially + + + align:start position:0% +flat space-time we can use essentially +special relativity rules apply and that + + align:start position:0% +special relativity rules apply and that + + + align:start position:0% +special relativity rules apply and that +gives us some insight into what this + + align:start position:0% +gives us some insight into what this + + + align:start position:0% +gives us some insight into what this +coordinate t means the T that we are + + align:start position:0% +coordinate t means the T that we are + + + align:start position:0% +coordinate t means the T that we are +using in the Schwarzschild coordinate + + align:start position:0% +using in the Schwarzschild coordinate + + + align:start position:0% +using in the Schwarzschild coordinate +system this is time as measured by + + align:start position:0% +system this is time as measured by + + + align:start position:0% +system this is time as measured by +distant observers tau is time as + + align:start position:0% +distant observers tau is time as + + + align:start position:0% +distant observers tau is time as +measured by this in flying observer so + + align:start position:0% +measured by this in flying observer so + + + align:start position:0% +measured by this in flying observer so +what we are seeing here is the in flying + + align:start position:0% +what we are seeing here is the in flying + + + align:start position:0% +what we are seeing here is the in flying +observer crosses to G M reaches R equals + + align:start position:0% +observer crosses to G M reaches R equals + + + align:start position:0% +observer crosses to G M reaches R equals +0 and has a very short life but those + + align:start position:0% +0 and has a very short life but those + + + align:start position:0% +0 and has a very short life but those +who are using clocks adapted to things + + align:start position:0% +who are using clocks adapted to things + + + align:start position:0% +who are using clocks adapted to things +very very far away never even see it + + align:start position:0% +very very far away never even see it + + + align:start position:0% +very very far away never even see it +cross to G M why is that well we will + + align:start position:0% +cross to G M why is that well we will + + + align:start position:0% +cross to G M why is that well we will +pick this up in the next lecture but let + + align:start position:0% +pick this up in the next lecture but let + + + align:start position:0% +pick this up in the next lecture but let +me remind you that when we initially + + align:start position:0% +me remind you that when we initially + + + align:start position:0% +me remind you that when we initially +began working on this subject one of the + + align:start position:0% +began working on this subject one of the + + + align:start position:0% +began working on this subject one of the +very first lectures we talked about + + align:start position:0% +very first lectures we talked about + + + align:start position:0% +very first lectures we talked about +something called the Einstein + + align:start position:0% +something called the Einstein + + + align:start position:0% +something called the Einstein +synchronization procedure where what we + + align:start position:0% +synchronization procedure where what we + + + align:start position:0% +synchronization procedure where what we +did was we imagine space-time was filled + + align:start position:0% +did was we imagine space-time was filled + + + align:start position:0% +did was we imagine space-time was filled +with a conceptual lattice of + + align:start position:0% +with a conceptual lattice of + + + align:start position:0% +with a conceptual lattice of +measuring-rods and clocks and we + + align:start position:0% +measuring-rods and clocks and we + + + align:start position:0% +measuring-rods and clocks and we +synchronized all of those + + align:start position:0% +synchronized all of those + + + align:start position:0% +synchronized all of those +clocks by requiring that they be that + + align:start position:0% +clocks by requiring that they be that + + + align:start position:0% +clocks by requiring that they be that +the sort of time delay between different + + align:start position:0% +the sort of time delay between different + + + align:start position:0% +the sort of time delay between different +clocks is synchronized according to the + + align:start position:0% +clocks is synchronized according to the + + + align:start position:0% +clocks is synchronized according to the +time it takes from light to travel from + + align:start position:0% +time it takes from light to travel from + + + align:start position:0% +time it takes from light to travel from +one to the other this is telling us we + + align:start position:0% +one to the other this is telling us we + + + align:start position:0% +one to the other this is telling us we +are actually working when we use Schwarz + + align:start position:0% +are actually working when we use Schwarz + + + align:start position:0% +are actually working when we use Schwarz +yield time we are working in a system + + align:start position:0% +yield time we are working in a system + + + align:start position:0% +yield time we are working in a system +that reflects sort of an underlying + + align:start position:0% +that reflects sort of an underlying + + + align:start position:0% +that reflects sort of an underlying +inheritance from special relativity + + align:start position:0% +inheritance from special relativity + + + align:start position:0% +inheritance from special relativity +these are clocks that have been + + align:start position:0% +these are clocks that have been + + + align:start position:0% +these are clocks that have been +synchronized by the Einstein + + align:start position:0% +synchronized by the Einstein + + + align:start position:0% +synchronized by the Einstein +synchronization procedure and so the + + align:start position:0% +synchronization procedure and so the + + + align:start position:0% +synchronization procedure and so the +pathological behavior that we see here + + align:start position:0% +pathological behavior that we see here + + + align:start position:0% +pathological behavior that we see here +it must ultimately Oh to the behavior of + + align:start position:0% +it must ultimately Oh to the behavior of + + + align:start position:0% +it must ultimately Oh to the behavior of +these clocks that we use to define our + + align:start position:0% +these clocks that we use to define our + + + align:start position:0% +these clocks that we use to define our +coordinate system and the behavior of + + align:start position:0% +coordinate system and the behavior of + + + align:start position:0% +coordinate system and the behavior of +those clocks is linked to the behavior + + align:start position:0% +those clocks is linked to the behavior + + + align:start position:0% +those clocks is linked to the behavior +of light so in order to get insight as + + align:start position:0% +of light so in order to get insight as + + + align:start position:0% +of light so in order to get insight as +to what is going on with this why is it + + align:start position:0% +to what is going on with this why is it + + + align:start position:0% +to what is going on with this why is it +that if I use a clock adapted the + + align:start position:0% +that if I use a clock adapted the + + + align:start position:0% +that if I use a clock adapted the +inflowing body + + align:start position:0% +inflowing body + + + align:start position:0% +inflowing body +I see painful death but if I use a clock + + align:start position:0% +I see painful death but if I use a clock + + + align:start position:0% +I see painful death but if I use a clock +adopted to someone very far away I don't + + align:start position:0% +adopted to someone very far away I don't + + + align:start position:0% +adopted to someone very far away I don't +even see it approach that dangerous R + + align:start position:0% +even see it approach that dangerous R + + + align:start position:0% +even see it approach that dangerous R +equals zero radius in order to resolve + + align:start position:0% +equals zero radius in order to resolve + + + align:start position:0% +equals zero radius in order to resolve +that mystery I'm going to need to + + align:start position:0% +that mystery I'm going to need to + + + align:start position:0% +that mystery I'm going to need to +examine what the motion of light looks + + align:start position:0% +examine what the motion of light looks + + + align:start position:0% +examine what the motion of light looks +like in this space-time we'll pick that + + align:start position:0% +like in this space-time we'll pick that + + + align:start position:0% +like in this space-time we'll pick that +up in the next lecture \ No newline at end of file diff --git a/KLBCUx1is2c.txt b/KLBCUx1is2c.txt new file mode 100644 index 0000000000000000000000000000000000000000..3860c84e58adb0f9eb259539efba5bc51fa54359 --- /dev/null +++ b/KLBCUx1is2c.txt @@ -0,0 +1,12315 @@ +align:start position:0% + +all right welcome back to double06 + + align:start position:0% +all right welcome back to double06 + + + align:start position:0% +all right welcome back to double06 +dynamic programming + + align:start position:0% +dynamic programming + + + align:start position:0% +dynamic programming +we're now in step two out of four + + align:start position:0% +we're now in step two out of four + + + align:start position:0% +we're now in step two out of four +gonna see a bunch more examples three + + align:start position:0% +gonna see a bunch more examples three + + + align:start position:0% +gonna see a bunch more examples three +more examples of that dynamic + + align:start position:0% +more examples of that dynamic + + + align:start position:0% +more examples of that dynamic +programming + + align:start position:0% +programming + + + align:start position:0% +programming +longest common sub sequence longest + + align:start position:0% +longest common sub sequence longest + + + align:start position:0% +longest common sub sequence longest +increasing subsequence and uh kind of a + + align:start position:0% +increasing subsequence and uh kind of a + + + align:start position:0% +increasing subsequence and uh kind of a +made up problem from w6 alternating coin + + align:start position:0% +made up problem from w6 alternating coin + + + align:start position:0% +made up problem from w6 alternating coin +game + + align:start position:0% +game + + + align:start position:0% +game +and through those examples we're going + + align:start position:0% +and through those examples we're going + + + align:start position:0% +and through those examples we're going +to explore a few + + align:start position:0% +to explore a few + + + align:start position:0% +to explore a few +uh new ideas things we haven't seen in + + align:start position:0% +uh new ideas things we haven't seen in + + + align:start position:0% +uh new ideas things we haven't seen in +action before yet + + align:start position:0% +action before yet + + + align:start position:0% +action before yet +dealing with multiple sequences instead + + align:start position:0% +dealing with multiple sequences instead + + + align:start position:0% +dealing with multiple sequences instead +of just one dealing with + + align:start position:0% +of just one dealing with + + + align:start position:0% +of just one dealing with +sub strings of sequences instead of + + align:start position:0% +sub strings of sequences instead of + + + align:start position:0% +sub strings of sequences instead of +prefixes and suffixes + + align:start position:0% +prefixes and suffixes + + + align:start position:0% +prefixes and suffixes +parent pointers so we can recover + + align:start position:0% +parent pointers so we can recover + + + align:start position:0% +parent pointers so we can recover +solutions like and shortest paths + + align:start position:0% +solutions like and shortest paths + + + align:start position:0% +solutions like and shortest paths +and a big one which will mostly be + + align:start position:0% +and a big one which will mostly be + + + align:start position:0% +and a big one which will mostly be +fleshed out in the next lecture + + align:start position:0% +fleshed out in the next lecture + + + align:start position:0% +fleshed out in the next lecture +is sub problem constraint and expansion + + align:start position:0% +is sub problem constraint and expansion + + + align:start position:0% +is sub problem constraint and expansion +this is all + + align:start position:0% +this is all + + + align:start position:0% +this is all +part of the sort bot paradigm + + align:start position:0% +part of the sort bot paradigm + + + align:start position:0% +part of the sort bot paradigm +remember subproblems relations + + align:start position:0% +remember subproblems relations + + + align:start position:0% +remember subproblems relations +topological order base case original + + align:start position:0% +topological order base case original + + + align:start position:0% +topological order base case original +problem and time + + align:start position:0% +problem and time + + + align:start position:0% +problem and time +here is subproblems and relations i've + + align:start position:0% +here is subproblems and relations i've + + + align:start position:0% +here is subproblems and relations i've +written down both what these things are + + align:start position:0% +written down both what these things are + + + align:start position:0% +written down both what these things are +and the sort of key lessons we got from + + align:start position:0% +and the sort of key lessons we got from + + + align:start position:0% +and the sort of key lessons we got from +the first dynamic programming lecture + + align:start position:0% +the first dynamic programming lecture + + + align:start position:0% +the first dynamic programming lecture +namely we want to split up our problem + + align:start position:0% +namely we want to split up our problem + + + align:start position:0% +namely we want to split up our problem +into multiple sub problems and + + align:start position:0% +into multiple sub problems and + + + align:start position:0% +into multiple sub problems and +if your input is a sequence that's the + + align:start position:0% +if your input is a sequence that's the + + + align:start position:0% +if your input is a sequence that's the +main case we've seen so far + + align:start position:0% +main case we've seen so far + + + align:start position:0% +main case we've seen so far +like the bowling problem for example + + align:start position:0% +like the bowling problem for example + + + align:start position:0% +like the bowling problem for example +then + + align:start position:0% +then + + + align:start position:0% +then +the natural subproblems to try are + + align:start position:0% +the natural subproblems to try are + + + align:start position:0% +the natural subproblems to try are +prefixes suffixes or substrings + + align:start position:0% +prefixes suffixes or substrings + + + align:start position:0% +prefixes suffixes or substrings +prefixes and suffixes are nice because + + align:start position:0% +prefixes and suffixes are nice because + + + align:start position:0% +prefixes and suffixes are nice because +there's few of them there's only a + + align:start position:0% +there's few of them there's only a + + + align:start position:0% +there's few of them there's only a +linear number of them + + align:start position:0% +linear number of them + + + align:start position:0% +linear number of them +in general we want a polynomial number + + align:start position:0% +in general we want a polynomial number + + + align:start position:0% +in general we want a polynomial number +sometimes you can get away with one of + + align:start position:0% +sometimes you can get away with one of + + + align:start position:0% +sometimes you can get away with one of +these they're usually about the same + + align:start position:0% +these they're usually about the same + + + align:start position:0% +these they're usually about the same +sometimes you need substrings there's + + align:start position:0% +sometimes you need substrings there's + + + align:start position:0% +sometimes you need substrings there's +quadratically many of those + + align:start position:0% +quadratically many of those + + + align:start position:0% +quadratically many of those +then once you set up the sub problems + + align:start position:0% +then once you set up the sub problems + + + align:start position:0% +then once you set up the sub problems +which + + align:start position:0% +which + + + align:start position:0% +which +it's easy to set up sub problems but + + align:start position:0% +it's easy to set up sub problems but + + + align:start position:0% +it's easy to set up sub problems but +hard to do it right + + align:start position:0% +hard to do it right + + + align:start position:0% +hard to do it right +to test whether you did it right is can + + align:start position:0% +to test whether you did it right is can + + + align:start position:0% +to test whether you did it right is can +i write a recurrence relation + + align:start position:0% +i write a recurrence relation + + + align:start position:0% +i write a recurrence relation +that relates one sub-problem solution to + + align:start position:0% +that relates one sub-problem solution to + + + align:start position:0% +that relates one sub-problem solution to +smaller sub-problems + + align:start position:0% +smaller sub-problems + + + align:start position:0% +smaller sub-problems +solutions and the general trick for + + align:start position:0% +solutions and the general trick for + + + align:start position:0% +solutions and the general trick for +doing this is to identify + + align:start position:0% +doing this is to identify + + + align:start position:0% +doing this is to identify +some feature of the solution you're + + align:start position:0% +some feature of the solution you're + + + align:start position:0% +some feature of the solution you're +looking for so you're trying to solve + + align:start position:0% +looking for so you're trying to solve + + + align:start position:0% +looking for so you're trying to solve +some sub-problem + + align:start position:0% +some sub-problem + + + align:start position:0% +some sub-problem +and you try to ask a question whose + + align:start position:0% +and you try to ask a question whose + + + align:start position:0% +and you try to ask a question whose +answer + + align:start position:0% +answer + + + align:start position:0% +answer +would let you reduce to a smaller + + align:start position:0% +would let you reduce to a smaller + + + align:start position:0% +would let you reduce to a smaller +sub-problem so if you can figure out + + align:start position:0% +sub-problem so if you can figure out + + + align:start position:0% +sub-problem so if you can figure out +what that question is and that question + + align:start position:0% +what that question is and that question + + + align:start position:0% +what that question is and that question +only has a polynomial number of answers + + align:start position:0% +only has a polynomial number of answers + + + align:start position:0% +only has a polynomial number of answers +then boom and you've only got polynomial + + align:start position:0% +then boom and you've only got polynomial + + + align:start position:0% +then boom and you've only got polynomial +number of subproblems then you will get + + align:start position:0% +number of subproblems then you will get + + + align:start position:0% +number of subproblems then you will get +a polynomial running time + + align:start position:0% +a polynomial running time + + + align:start position:0% +a polynomial running time +so i have i think another way to say + + align:start position:0% +so i have i think another way to say + + + align:start position:0% +so i have i think another way to say +this + + align:start position:0% +this + + + align:start position:0% +this +we just locally brute force all possible + + align:start position:0% +we just locally brute force all possible + + + align:start position:0% +we just locally brute force all possible +answers to whatever + + align:start position:0% +answers to whatever + + + align:start position:0% +answers to whatever +question we come up with as long as + + align:start position:0% +question we come up with as long as + + + align:start position:0% +question we come up with as long as +there's polynomially many + + align:start position:0% +there's polynomially many + + + align:start position:0% +there's polynomially many +and then each of them is going to + + align:start position:0% +and then each of them is going to + + + align:start position:0% +and then each of them is going to +recursively call + + align:start position:0% +recursively call + + + align:start position:0% +recursively call +the smaller sub-problems but because we + + align:start position:0% +the smaller sub-problems but because we + + + align:start position:0% +the smaller sub-problems but because we +memoize we'll only solve each + + align:start position:0% +memoize we'll only solve each + + + align:start position:0% +memoize we'll only solve each +sub-problem once + + align:start position:0% +sub-problem once + + + align:start position:0% +sub-problem once +and so in the end the running time will + + align:start position:0% +and so in the end the running time will + + + align:start position:0% +and so in the end the running time will +be at most the number + + align:start position:0% +be at most the number + + + align:start position:0% +be at most the number +of subproblems times the non-recursive + + align:start position:0% +of subproblems times the non-recursive + + + align:start position:0% +of subproblems times the non-recursive +work done in that relation + + align:start position:0% +work done in that relation + + + align:start position:0% +work done in that relation +for that to work of course the relations + + align:start position:0% +for that to work of course the relations + + + align:start position:0% +for that to work of course the relations +between subproblems must be acyclic + + align:start position:0% +between subproblems must be acyclic + + + align:start position:0% +between subproblems must be acyclic +so we'd like to give an explicit + + align:start position:0% +so we'd like to give an explicit + + + align:start position:0% +so we'd like to give an explicit +topological order usually it's a couple + + align:start position:0% +topological order usually it's a couple + + + align:start position:0% +topological order usually it's a couple +of for loops + + align:start position:0% +of for loops + + + align:start position:0% +of for loops +but this is a topological order in the + + align:start position:0% +but this is a topological order in the + + + align:start position:0% +but this is a topological order in the +subproblem dag + + align:start position:0% +subproblem dag + + + align:start position:0% +subproblem dag +which i defined somewhat informally last + + align:start position:0% +which i defined somewhat informally last + + + align:start position:0% +which i defined somewhat informally last +time but if i have to + + align:start position:0% +time but if i have to + + + align:start position:0% +time but if i have to +the vertices are are sub problems and i + + align:start position:0% +the vertices are are sub problems and i + + + align:start position:0% +the vertices are are sub problems and i +want to draw an edge + + align:start position:0% +want to draw an edge + + + align:start position:0% +want to draw an edge +from a smaller problem to a bigger + + align:start position:0% +from a smaller problem to a bigger + + + align:start position:0% +from a smaller problem to a bigger +problem meaning that if + + align:start position:0% +problem meaning that if + + + align:start position:0% +problem meaning that if +evaluating b in this relation calls a + + align:start position:0% +evaluating b in this relation calls a + + + align:start position:0% +evaluating b in this relation calls a +then i'll draw an arrow from a to b from + + align:start position:0% +then i'll draw an arrow from a to b from + + + align:start position:0% +then i'll draw an arrow from a to b from +the things i need to do first + + align:start position:0% +the things i need to do first + + + align:start position:0% +the things i need to do first +to the things i'll do later so then + + align:start position:0% +to the things i'll do later so then + + + align:start position:0% +to the things i'll do later so then +topological order + + align:start position:0% +topological order + + + align:start position:0% +topological order +will be ready by the time i can try to + + align:start position:0% +will be ready by the time i can try to + + + align:start position:0% +will be ready by the time i can try to +compute b + + align:start position:0% +compute b + + + align:start position:0% +compute b +i will have already computed a uh and of + + align:start position:0% +i will have already computed a uh and of + + + align:start position:0% +i will have already computed a uh and of +course the relation also needs base + + align:start position:0% +course the relation also needs base + + + align:start position:0% +course the relation also needs base +cases + + align:start position:0% +cases + + + align:start position:0% +cases +and then sometimes the sub the original + + align:start position:0% +and then sometimes the sub the original + + + align:start position:0% +and then sometimes the sub the original +problem we want to solve is just one of + + align:start position:0% +problem we want to solve is just one of + + + align:start position:0% +problem we want to solve is just one of +those sub problems + + align:start position:0% +those sub problems + + + align:start position:0% +those sub problems +sometimes we need to combine multiple + + align:start position:0% +sometimes we need to combine multiple + + + align:start position:0% +sometimes we need to combine multiple +we'll see that today + + align:start position:0% +we'll see that today + + + align:start position:0% +we'll see that today +so that's review of this framework + + align:start position:0% +so that's review of this framework + + + align:start position:0% +so that's review of this framework +and let's dive into longest common + + align:start position:0% +and let's dive into longest common + + + align:start position:0% +and let's dive into longest common +subsequence + + align:start position:0% + + + + align:start position:0% + +this is kind of a classic problem + + align:start position:0% + + + + align:start position:0% + +it even has applications to things like + + align:start position:0% +it even has applications to things like + + + align:start position:0% +it even has applications to things like +computational biology you have two dna + + align:start position:0% +computational biology you have two dna + + + align:start position:0% +computational biology you have two dna +sequences you want to + + align:start position:0% +sequences you want to + + + align:start position:0% +sequences you want to +measure how in common they are one + + align:start position:0% +measure how in common they are one + + + align:start position:0% +measure how in common they are one +version of that + + align:start position:0% +version of that + + + align:start position:0% +version of that +you might see other versions in + + align:start position:0% +you might see other versions in + + + align:start position:0% +you might see other versions in +recitation called edit distance this + + align:start position:0% +recitation called edit distance this + + + align:start position:0% +recitation called edit distance this +is sort of a simplest cleanish version + + align:start position:0% +is sort of a simplest cleanish version + + + align:start position:0% +is sort of a simplest cleanish version +where i give you two sequences + + align:start position:0% +where i give you two sequences + + + align:start position:0% +where i give you two sequences +i have two examples an example here + + align:start position:0% +i have two examples an example here + + + align:start position:0% +i have two examples an example here +so for example it could be a sequence of + + align:start position:0% +so for example it could be a sequence of + + + align:start position:0% +so for example it could be a sequence of +letters + + align:start position:0% + + + + align:start position:0% + +so my first sequence spells + + align:start position:0% +so my first sequence spells + + + align:start position:0% +so my first sequence spells +hieroglyphology + + align:start position:0% +hieroglyphology + + + align:start position:0% +hieroglyphology +study of hieroglyphs and second sequence + + align:start position:0% +study of hieroglyphs and second sequence + + + align:start position:0% +study of hieroglyphs and second sequence +spells michelangelo + + align:start position:0% + + + + align:start position:0% + +and what i'd like is a subsequence so + + align:start position:0% +and what i'd like is a subsequence so + + + align:start position:0% +and what i'd like is a subsequence so +remember + + align:start position:0% +remember + + + align:start position:0% +remember +sub string has to be some continuous + + align:start position:0% +sub string has to be some continuous + + + align:start position:0% +sub string has to be some continuous +range some interval + + align:start position:0% +range some interval + + + align:start position:0% +range some interval +subsequence you can take any subset of + + align:start position:0% +subsequence you can take any subset of + + + align:start position:0% +subsequence you can take any subset of +the letters + + align:start position:0% +the letters + + + align:start position:0% +the letters +in your sequence or any subset of the + + align:start position:0% +in your sequence or any subset of the + + + align:start position:0% +in your sequence or any subset of the +items in your sequence so you can have + + align:start position:0% +items in your sequence so you can have + + + align:start position:0% +items in your sequence so you can have +blanks in between you can skip over + + align:start position:0% +blanks in between you can skip over + + + align:start position:0% +blanks in between you can skip over +items + + align:start position:0% +items + + + align:start position:0% +items +and so what we want is the longest + + align:start position:0% +and so what we want is the longest + + + align:start position:0% +and so what we want is the longest +sequence + + align:start position:0% +sequence + + + align:start position:0% +sequence +that is a subsequence of both the first + + align:start position:0% +that is a subsequence of both the first + + + align:start position:0% +that is a subsequence of both the first +string the first sequence and + + align:start position:0% +string the first sequence and + + + align:start position:0% +string the first sequence and +the second string and if you stare at + + align:start position:0% +the second string and if you stare at + + + align:start position:0% +the second string and if you stare at +this long enough + + align:start position:0% +this long enough + + + align:start position:0% +this long enough +the longest common subsequence i'm not i + + align:start position:0% +the longest common subsequence i'm not i + + + align:start position:0% +the longest common subsequence i'm not i +don't think it's unique but there is a + + align:start position:0% +don't think it's unique but there is a + + + align:start position:0% +don't think it's unique but there is a +longest common subsequence which is + + align:start position:0% +longest common subsequence which is + + + align:start position:0% +longest common subsequence which is +uh hello + + align:start position:0% +uh hello + + + align:start position:0% +uh hello +hiding in there + + align:start position:0% + + + + align:start position:0% + +and that is a longest common subsequence + + align:start position:0% +and that is a longest common subsequence + + + align:start position:0% +and that is a longest common subsequence +so given that input + + align:start position:0% +so given that input + + + align:start position:0% +so given that input +the goal is to + + align:start position:0% + + + + align:start position:0% + +compute hello or whatever longest common + + align:start position:0% +compute hello or whatever longest common + + + align:start position:0% +compute hello or whatever longest common +subsequence is so we're given + + align:start position:0% +subsequence is so we're given + + + align:start position:0% +subsequence is so we're given +write this down carefully given two + + align:start position:0% +write this down carefully given two + + + align:start position:0% +write this down carefully given two +sequences let me name them + + align:start position:0% +sequences let me name them + + + align:start position:0% +sequences let me name them +a and b + + align:start position:0% + + + + align:start position:0% + +we want to find the longest + + align:start position:0% + + + + align:start position:0% + +sequence l + + align:start position:0% +sequence l + + + align:start position:0% +sequence l +that's a subsequence of both a and b + + align:start position:0% + + + + align:start position:0% + +so that's the problem definition + + align:start position:0% +so that's the problem definition + + + align:start position:0% +so that's the problem definition +and we're going to see how to solve it + + align:start position:0% +and we're going to see how to solve it + + + align:start position:0% +and we're going to see how to solve it +using dynamic programming + + align:start position:0% +using dynamic programming + + + align:start position:0% +using dynamic programming +and whereas in the bowling problem we + + align:start position:0% +and whereas in the bowling problem we + + + align:start position:0% +and whereas in the bowling problem we +just had a single + + align:start position:0% +just had a single + + + align:start position:0% +just had a single +sequence of numbers the values of the + + align:start position:0% +sequence of numbers the values of the + + + align:start position:0% +sequence of numbers the values of the +bowling pins + + align:start position:0% +bowling pins + + + align:start position:0% +bowling pins +here we have two sequences and so we + + align:start position:0% +here we have two sequences and so we + + + align:start position:0% +here we have two sequences and so we +need a new trick + + align:start position:0% +need a new trick + + + align:start position:0% +need a new trick +before we said okay if our sub-problems + + align:start position:0% +before we said okay if our sub-problems + + + align:start position:0% +before we said okay if our sub-problems +or sorry if our input consists of a + + align:start position:0% +or sorry if our input consists of a + + + align:start position:0% +or sorry if our input consists of a +single sequence we'll try prefixes + + align:start position:0% +single sequence we'll try prefixes + + + align:start position:0% +single sequence we'll try prefixes +suffixes or substrings + + align:start position:0% +suffixes or substrings + + + align:start position:0% +suffixes or substrings +now we've got two sequences so somehow + + align:start position:0% +now we've got two sequences so somehow + + + align:start position:0% +now we've got two sequences so somehow +we need to combine + + align:start position:0% +we need to combine + + + align:start position:0% +we need to combine +multiple input + + align:start position:0% +multiple input + + + align:start position:0% +multiple input +together and so + + align:start position:0% +together and so + + + align:start position:0% +together and so +here's a general trick sub problems + + align:start position:0% +here's a general trick sub problems + + + align:start position:0% +here's a general trick sub problems +for multiple + + align:start position:0% +for multiple + + + align:start position:0% +for multiple +inputs it's a very simple trick + + align:start position:0% +inputs it's a very simple trick + + + align:start position:0% +inputs it's a very simple trick +we just take the + + align:start position:0% +we just take the + + + align:start position:0% +we just take the +product multiply + + align:start position:0% + + + + align:start position:0% + +the sub subproblem spaces + + align:start position:0% + + + + align:start position:0% + +okay in the sense of cross product of + + align:start position:0% +okay in the sense of cross product of + + + align:start position:0% +okay in the sense of cross product of +sets + + align:start position:0% +sets + + + align:start position:0% +sets +and in particular from a combinatorial + + align:start position:0% +and in particular from a combinatorial + + + align:start position:0% +and in particular from a combinatorial +perspective so we have sort of two + + align:start position:0% +perspective so we have sort of two + + + align:start position:0% +perspective so we have sort of two +inputs the first sequence a and the + + align:start position:0% +inputs the first sequence a and the + + + align:start position:0% +inputs the first sequence a and the +second sequence b + + align:start position:0% +second sequence b + + + align:start position:0% +second sequence b +for each of them there's a natural + + align:start position:0% +for each of them there's a natural + + + align:start position:0% +for each of them there's a natural +choice or there's three natural choices + + align:start position:0% +choice or there's three natural choices + + + align:start position:0% +choice or there's three natural choices +we could do one of these i will choose + + align:start position:0% +we could do one of these i will choose + + + align:start position:0% +we could do one of these i will choose +suffixes for a and suffix is for b you + + align:start position:0% +suffixes for a and suffix is for b you + + + align:start position:0% +suffixes for a and suffix is for b you +could do some + + align:start position:0% +could do some + + + align:start position:0% +could do some +other combination but that will be + + align:start position:0% +other combination but that will be + + + align:start position:0% +other combination but that will be +enough for here and then i want to + + align:start position:0% +enough for here and then i want to + + + align:start position:0% +enough for here and then i want to +multiply these spaces meaning + + align:start position:0% +multiply these spaces meaning + + + align:start position:0% +multiply these spaces meaning +the number of subproblems is going to be + + align:start position:0% +the number of subproblems is going to be + + + align:start position:0% +the number of subproblems is going to be +the product of the number of suffixes + + align:start position:0% +the product of the number of suffixes + + + align:start position:0% +the product of the number of suffixes +here + + align:start position:0% +here + + + align:start position:0% +here +times the number of suffixes here okay + + align:start position:0% +times the number of suffixes here okay + + + align:start position:0% +times the number of suffixes here okay +and in other words every subproblem in + + align:start position:0% +and in other words every subproblem in + + + align:start position:0% +and in other words every subproblem in +lcs is going to be + + align:start position:0% +lcs is going to be + + + align:start position:0% +lcs is going to be +a pair of suffixes so let me + + align:start position:0% +a pair of suffixes so let me + + + align:start position:0% +a pair of suffixes so let me +write that down so for + + align:start position:0% +write that down so for + + + align:start position:0% +write that down so for +for lcs + + align:start position:0% + + + + align:start position:0% + +our subproblems + + align:start position:0% + + + + align:start position:0% + +are l of i j + + align:start position:0% +are l of i j + + + align:start position:0% +are l of i j +this is going to be the longest common + + align:start position:0% +this is going to be the longest common + + + align:start position:0% +this is going to be the longest common +subsequence of + + align:start position:0% +subsequence of + + + align:start position:0% +subsequence of +the suffix of a starting at i and the + + align:start position:0% +the suffix of a starting at i and the + + + align:start position:0% +the suffix of a starting at i and the +suffix of b + + align:start position:0% +suffix of b + + + align:start position:0% +suffix of b +starting at j + + align:start position:0% + + + + align:start position:0% + +and just to be clear how many there are + + align:start position:0% +and just to be clear how many there are + + + align:start position:0% +and just to be clear how many there are +i'll give the ranges for i and j + + align:start position:0% +i'll give the ranges for i and j + + + align:start position:0% +i'll give the ranges for i and j +i'm not going to assume the sequences + + align:start position:0% +i'm not going to assume the sequences + + + align:start position:0% +i'm not going to assume the sequences +are the same length like in the example + + align:start position:0% +are the same length like in the example + + + align:start position:0% +are the same length like in the example +so right lengths of a and less than b i + + align:start position:0% +so right lengths of a and less than b i + + + align:start position:0% +so right lengths of a and less than b i +like to include the empty suffix + + align:start position:0% +like to include the empty suffix + + + align:start position:0% +like to include the empty suffix +so when j equals the length of b that's + + align:start position:0% +so when j equals the length of b that's + + + align:start position:0% +so when j equals the length of b that's +a + + align:start position:0% +a + + + align:start position:0% +a +zero items in it because that makes for + + align:start position:0% +zero items in it because that makes for + + + align:start position:0% +zero items in it because that makes for +really easy base cases + + align:start position:0% +really easy base cases + + + align:start position:0% +really easy base cases +so i'd like to include those in my + + align:start position:0% +so i'd like to include those in my + + + align:start position:0% +so i'd like to include those in my +sub-problems + + align:start position:0% +sub-problems + + + align:start position:0% +sub-problems +so that was the s in sort bot + + align:start position:0% +so that was the s in sort bot + + + align:start position:0% +so that was the s in sort bot +now i claim that that set of subproblems + + align:start position:0% +now i claim that that set of subproblems + + + align:start position:0% +now i claim that that set of subproblems +is enough to do + + align:start position:0% +is enough to do + + + align:start position:0% +is enough to do +a relation + + align:start position:0% + + + + align:start position:0% + +recursive relation among them so i'd + + align:start position:0% +recursive relation among them so i'd + + + align:start position:0% +recursive relation among them so i'd +like to solve + + align:start position:0% +like to solve + + + align:start position:0% +like to solve +every subproblem l i j + + align:start position:0% +every subproblem l i j + + + align:start position:0% +every subproblem l i j +and uh relation is actually pretty + + align:start position:0% +and uh relation is actually pretty + + + align:start position:0% +and uh relation is actually pretty +simple but + + align:start position:0% +simple but + + + align:start position:0% +simple but +it's maybe not so obvious so the idea is + + align:start position:0% +it's maybe not so obvious so the idea is + + + align:start position:0% +it's maybe not so obvious so the idea is +because we're looking at suffixes we + + align:start position:0% +because we're looking at suffixes we + + + align:start position:0% +because we're looking at suffixes we +should always think about what happens + + align:start position:0% +should always think about what happens + + + align:start position:0% +should always think about what happens +in the first + + align:start position:0% +in the first + + + align:start position:0% +in the first +letter um because if we remove that + + align:start position:0% +letter um because if we remove that + + + align:start position:0% +letter um because if we remove that +first letter then we get a smaller + + align:start position:0% +first letter then we get a smaller + + + align:start position:0% +first letter then we get a smaller +suffix + + align:start position:0% +suffix + + + align:start position:0% +suffix +if you're doing prefixes you should + + align:start position:0% +if you're doing prefixes you should + + + align:start position:0% +if you're doing prefixes you should +always look at the last letter either + + align:start position:0% +always look at the last letter either + + + align:start position:0% +always look at the last letter either +one would work for this problem + + align:start position:0% +one would work for this problem + + + align:start position:0% +one would work for this problem +so we're doing suffixes so we look at a + + align:start position:0% +so we're doing suffixes so we look at a + + + align:start position:0% +so we're doing suffixes so we look at a +of i + + align:start position:0% +of i + + + align:start position:0% +of i +and we look at b of j + + align:start position:0% + + + + align:start position:0% + +that's the first letter in in the suffix + + align:start position:0% +that's the first letter in in the suffix + + + align:start position:0% +that's the first letter in in the suffix +a starting at i + + align:start position:0% +a starting at i + + + align:start position:0% +a starting at i +and the suffix b starting at j + + align:start position:0% +and the suffix b starting at j + + + align:start position:0% +and the suffix b starting at j +and there are two cases they could be + + align:start position:0% +and there are two cases they could be + + + align:start position:0% +and there are two cases they could be +equal or + + align:start position:0% +equal or + + + align:start position:0% +equal or +different + + align:start position:0% + + + + align:start position:0% + +i think the easier case to think about + + align:start position:0% +i think the easier case to think about + + + align:start position:0% +i think the easier case to think about +is when they're different so + + align:start position:0% +is when they're different so + + + align:start position:0% +is when they're different so +like in hieroglyphology and michelangelo + + align:start position:0% +like in hieroglyphology and michelangelo + + + align:start position:0% +like in hieroglyphology and michelangelo +if we look at the whole string say the + + align:start position:0% +if we look at the whole string say the + + + align:start position:0% +if we look at the whole string say the +first letter in the top one is h + + align:start position:0% +first letter in the top one is h + + + align:start position:0% +first letter in the top one is h +the first letter and the second one is m + + align:start position:0% +the first letter and the second one is m + + + align:start position:0% +the first letter and the second one is m +those are different letters so clearly + + align:start position:0% +those are different letters so clearly + + + align:start position:0% +those are different letters so clearly +the one of those letters is not in the + + align:start position:0% +the one of those letters is not in the + + + align:start position:0% +the one of those letters is not in the +common subsequence + + align:start position:0% +common subsequence + + + align:start position:0% +common subsequence +because they don't match i can't start + + align:start position:0% +because they don't match i can't start + + + align:start position:0% +because they don't match i can't start +with an h i can't well i can start with + + align:start position:0% +with an h i can't well i can start with + + + align:start position:0% +with an h i can't well i can start with +an h i could start with an m but i can't + + align:start position:0% +an h i could start with an m but i can't + + + align:start position:0% +an h i could start with an m but i can't +start + + align:start position:0% +start + + + align:start position:0% +start +with both one of those letters is not in + + align:start position:0% +with both one of those letters is not in + + + align:start position:0% +with both one of those letters is not in +the output in this example + + align:start position:0% +the output in this example + + + align:start position:0% +the output in this example +it's m and so but i don't know which one + + align:start position:0% +it's m and so but i don't know which one + + + align:start position:0% +it's m and so but i don't know which one +so i have this question i want to + + align:start position:0% +so i have this question i want to + + + align:start position:0% +so i have this question i want to +identify some question + + align:start position:0% +identify some question + + + align:start position:0% +identify some question +the question is should i do i know that + + align:start position:0% +the question is should i do i know that + + + align:start position:0% +the question is should i do i know that +the h is not in the answer or do i know + + align:start position:0% +the h is not in the answer or do i know + + + align:start position:0% +the h is not in the answer or do i know +that m + + align:start position:0% +that m + + + align:start position:0% +that m +is not in the answer the final final + + align:start position:0% +is not in the answer the final final + + + align:start position:0% +is not in the answer the final final +longest common subsequence + + align:start position:0% +longest common subsequence + + + align:start position:0% +longest common subsequence +we don't know which so we'll just try + + align:start position:0% +we don't know which so we'll just try + + + align:start position:0% +we don't know which so we'll just try +both + + align:start position:0% +both + + + align:start position:0% +both +and then we're trying to maximize the + + align:start position:0% +and then we're trying to maximize the + + + align:start position:0% +and then we're trying to maximize the +length of our common subsequence so + + align:start position:0% +length of our common subsequence so + + + align:start position:0% +length of our common subsequence so +we'll take the max + + align:start position:0% +we'll take the max + + + align:start position:0% +we'll take the max +of uh + + align:start position:0% +of uh + + + align:start position:0% +of uh +l i plus 1 j + + align:start position:0% +l i plus 1 j + + + align:start position:0% +l i plus 1 j +and l i j minus 1. + + align:start position:0% + + + + align:start position:0% + +so the intuition here is one of + + align:start position:0% +so the intuition here is one of + + + align:start position:0% +so the intuition here is one of +at least one of ai and bj + + align:start position:0% +at least one of ai and bj + + + align:start position:0% +at least one of ai and bj +is not in the lcs + + align:start position:0% + + + + align:start position:0% + +uh get this wrong + + align:start position:0% +uh get this wrong + + + align:start position:0% +uh get this wrong +plus one sorry + + align:start position:0% +plus one sorry + + + align:start position:0% +plus one sorry +thinking about sub strings already yeah + + align:start position:0% +thinking about sub strings already yeah + + + align:start position:0% +thinking about sub strings already yeah +these are the beginning points so i want + + align:start position:0% +these are the beginning points so i want + + + align:start position:0% +these are the beginning points so i want +to exclude + + align:start position:0% +to exclude + + + align:start position:0% +to exclude +the i letter so if if a i is not in + + align:start position:0% +the i letter so if if a i is not in + + + align:start position:0% +the i letter so if if a i is not in +then i want to look at the suffix + + align:start position:0% +then i want to look at the suffix + + + align:start position:0% +then i want to look at the suffix +starting at i plus one if bj is not in + + align:start position:0% +starting at i plus one if bj is not in + + + align:start position:0% +starting at i plus one if bj is not in +then i want to look at the suffix + + align:start position:0% +then i want to look at the suffix + + + align:start position:0% +then i want to look at the suffix +starting at j plus 1. + + align:start position:0% +starting at j plus 1. + + + align:start position:0% +starting at j plus 1. +so the indices are always increasing in + + align:start position:0% +so the indices are always increasing in + + + align:start position:0% +so the indices are always increasing in +the function calls + + align:start position:0% + + + + align:start position:0% + +and the other case is that they're equal + + align:start position:0% +and the other case is that they're equal + + + align:start position:0% +and the other case is that they're equal +so this one + + align:start position:0% +so this one + + + align:start position:0% +so this one +i have a little bit harder time arguing + + align:start position:0% +i have a little bit harder time arguing + + + align:start position:0% +i have a little bit harder time arguing +i'm going to write the answer and then + + align:start position:0% +i'm going to write the answer and then + + + align:start position:0% +i'm going to write the answer and then +prove that the answer is correct + + align:start position:0% + + + + align:start position:0% + +here i claim you don't need to make any + + align:start position:0% +here i claim you don't need to make any + + + align:start position:0% +here i claim you don't need to make any +choices + + align:start position:0% +choices + + + align:start position:0% +choices +there's no question you need to answer + + align:start position:0% +there's no question you need to answer + + + align:start position:0% +there's no question you need to answer +you can actually guarantee + + align:start position:0% +you can actually guarantee + + + align:start position:0% +you can actually guarantee +that ai and bj might as well be + + align:start position:0% +that ai and bj might as well be + + + align:start position:0% +that ai and bj might as well be +in the longest common subsequence and so + + align:start position:0% +in the longest common subsequence and so + + + align:start position:0% +in the longest common subsequence and so +i get one point for that and then i + + align:start position:0% +i get one point for that and then i + + + align:start position:0% +i get one point for that and then i +recurse on all the remaining letters so + + align:start position:0% +recurse on all the remaining letters so + + + align:start position:0% +recurse on all the remaining letters so +from i plus one on + + align:start position:0% +from i plus one on + + + align:start position:0% +from i plus one on +and from j plus one on why is this okay + + align:start position:0% +and from j plus one on why is this okay + + + align:start position:0% +and from j plus one on why is this okay +well we have a b we're starting at + + align:start position:0% +well we have a b we're starting at + + + align:start position:0% +well we have a b we're starting at +position i + + align:start position:0% +position i + + + align:start position:0% +position i +and starting at position j for b + + align:start position:0% +and starting at position j for b + + + align:start position:0% +and starting at position j for b +um and think of some optimal solution + + align:start position:0% +um and think of some optimal solution + + + align:start position:0% +um and think of some optimal solution +some longest common subsequence so + + align:start position:0% +some longest common subsequence so + + + align:start position:0% +some longest common subsequence so +it pairs up letters in some + + align:start position:0% +it pairs up letters in some + + + align:start position:0% +it pairs up letters in some +some way these this would be some + + align:start position:0% +some way these this would be some + + + align:start position:0% +some way these this would be some +non-crossing pairing between + + align:start position:0% +non-crossing pairing between + + + align:start position:0% +non-crossing pairing between +equal letters uh and + + align:start position:0% +equal letters uh and + + + align:start position:0% +equal letters uh and +let's say uh so first case is that maybe + + align:start position:0% +let's say uh so first case is that maybe + + + align:start position:0% +let's say uh so first case is that maybe +i and j + + align:start position:0% +i and j + + + align:start position:0% +i and j +aren't paired with anything well that's + + align:start position:0% +aren't paired with anything well that's + + + align:start position:0% +aren't paired with anything well that's +silly because if they're not paired with + + align:start position:0% +silly because if they're not paired with + + + align:start position:0% +silly because if they're not paired with +anything you have some pairing on the + + align:start position:0% +anything you have some pairing on the + + + align:start position:0% +anything you have some pairing on the +rest of the items you can add this pair + + align:start position:0% +rest of the items you can add this pair + + + align:start position:0% +rest of the items you can add this pair +and that would be a longer subsequent so + + align:start position:0% +and that would be a longer subsequent so + + + align:start position:0% +and that would be a longer subsequent so +that would be a contradiction if we're + + align:start position:0% +that would be a contradiction if we're + + + align:start position:0% +that would be a contradiction if we're +taking + + align:start position:0% +taking + + + align:start position:0% +taking +imagining some hypothetical optimal + + align:start position:0% +imagining some hypothetical optimal + + + align:start position:0% +imagining some hypothetical optimal +solution it has to pair + + align:start position:0% +solution it has to pair + + + align:start position:0% +solution it has to pair +one of these with something maybe it + + align:start position:0% +one of these with something maybe it + + + align:start position:0% +one of these with something maybe it +pairs eye with something else though + + align:start position:0% +pairs eye with something else though + + + align:start position:0% +pairs eye with something else though +well if we have a longest comb sub + + align:start position:0% +well if we have a longest comb sub + + + align:start position:0% +well if we have a longest comb sub +sequence that looks like that + + align:start position:0% +sequence that looks like that + + + align:start position:0% +sequence that looks like that +i can just instead pair i with bj + + align:start position:0% +i can just instead pair i with bj + + + align:start position:0% +i can just instead pair i with bj +that's still uh you know if i had this + + align:start position:0% +that's still uh you know if i had this + + + align:start position:0% +that's still uh you know if i had this +pairing + + align:start position:0% +pairing + + + align:start position:0% +pairing +i'm actually not using any of these + + align:start position:0% +i'm actually not using any of these + + + align:start position:0% +i'm actually not using any of these +letters so why don't i just use this + + align:start position:0% +letters so why don't i just use this + + + align:start position:0% +letters so why don't i just use this +letter instead + + align:start position:0% +letter instead + + + align:start position:0% +letter instead +so you can argue there is a longest + + align:start position:0% +so you can argue there is a longest + + + align:start position:0% +so you can argue there is a longest +common subsequence that matches + + align:start position:0% +common subsequence that matches + + + align:start position:0% +common subsequence that matches +ai with bj and so then we can guarantee + + align:start position:0% +ai with bj and so then we can guarantee + + + align:start position:0% +ai with bj and so then we can guarantee +by that little proof that we get one + + align:start position:0% +by that little proof that we get one + + + align:start position:0% +by that little proof that we get one +point for + + align:start position:0% +point for + + + align:start position:0% +point for +matching them up and there's no that we + + align:start position:0% +matching them up and there's no that we + + + align:start position:0% +matching them up and there's no that we +don't have to max this with anything + + align:start position:0% +don't have to max this with anything + + + align:start position:0% +don't have to max this with anything +okay so two cases pretty simple formula + + align:start position:0% +okay so two cases pretty simple formula + + + align:start position:0% +okay so two cases pretty simple formula +um and then we're basically done we just + + align:start position:0% +um and then we're basically done we just + + + align:start position:0% +um and then we're basically done we just +need to fill in the rest of sort bot + + align:start position:0% +need to fill in the rest of sort bot + + + align:start position:0% +need to fill in the rest of sort bot +so next is topological order + + align:start position:0% + + + + align:start position:0% + +so this i'll write as for loops + + align:start position:0% + + + + align:start position:0% + +because i'm dealing with suffixes we + + align:start position:0% +because i'm dealing with suffixes we + + + align:start position:0% +because i'm dealing with suffixes we +want to start with the empty suffixes + + align:start position:0% +want to start with the empty suffixes + + + align:start position:0% +want to start with the empty suffixes +and then work our way to larger and + + align:start position:0% +and then work our way to larger and + + + align:start position:0% +and then work our way to larger and +larger suffixes so this might seem + + align:start position:0% +larger suffixes so this might seem + + + align:start position:0% +larger suffixes so this might seem +backwards if you're doing prefixes it + + align:start position:0% +backwards if you're doing prefixes it + + + align:start position:0% +backwards if you're doing prefixes it +would be an increasing order + + align:start position:0% +would be an increasing order + + + align:start position:0% +would be an increasing order +there's all sorts of orders you could + + align:start position:0% +there's all sorts of orders you could + + + align:start position:0% +there's all sorts of orders you could +flip the i and j it's very symmetric so + + align:start position:0% +flip the i and j it's very symmetric so + + + align:start position:0% +flip the i and j it's very symmetric so +it doesn't really matter + + align:start position:0% +it doesn't really matter + + + align:start position:0% +it doesn't really matter +but anything that's generally decreasing + + align:start position:0% +but anything that's generally decreasing + + + align:start position:0% +but anything that's generally decreasing +in inj + + align:start position:0% +in inj + + + align:start position:0% +in inj +is good then we have base cases + + align:start position:0% + + + + align:start position:0% + +uh these are when one of the sequences + + align:start position:0% +uh these are when one of the sequences + + + align:start position:0% +uh these are when one of the sequences +is empty + + align:start position:0% +is empty + + + align:start position:0% +is empty +i don't care how many items are in b but + + align:start position:0% +i don't care how many items are in b but + + + align:start position:0% +i don't care how many items are in b but +if a has no items there's no common + + align:start position:0% +if a has no items there's no common + + + align:start position:0% +if a has no items there's no common +subsequence i mean + + align:start position:0% +subsequence i mean + + + align:start position:0% +subsequence i mean +it's empty and same for uh + + align:start position:0% +it's empty and same for uh + + + align:start position:0% +it's empty and same for uh +no matter how big a is if i've exhausted + + align:start position:0% +no matter how big a is if i've exhausted + + + align:start position:0% +no matter how big a is if i've exhausted +the b string i start from beyond the + + align:start position:0% +the b string i start from beyond the + + + align:start position:0% +the b string i start from beyond the +last item + + align:start position:0% +last item + + + align:start position:0% +last item +then i should get 0. then the original + + align:start position:0% +then i should get 0. then the original + + + align:start position:0% +then i should get 0. then the original +problem we want to solve + + align:start position:0% + + + + align:start position:0% + +is l 0 0 that's just longest common + + align:start position:0% +is l 0 0 that's just longest common + + + align:start position:0% +is l 0 0 that's just longest common +subsequence of the entire a and the + + align:start position:0% +subsequence of the entire a and the + + + align:start position:0% +subsequence of the entire a and the +entire b + + align:start position:0% +entire b + + + align:start position:0% +entire b +and time + + align:start position:0% + + + + align:start position:0% + +okay so for time we need to know how + + align:start position:0% +okay so for time we need to know how + + + align:start position:0% +okay so for time we need to know how +many sub problems there are it's + + align:start position:0% +many sub problems there are it's + + + align:start position:0% +many sub problems there are it's +a plus one times b plus one + + align:start position:0% +a plus one times b plus one + + + align:start position:0% +a plus one times b plus one +i'll just call that theta a b so these + + align:start position:0% +i'll just call that theta a b so these + + + align:start position:0% +i'll just call that theta a b so these +are + + align:start position:0% +are + + + align:start position:0% +are +non-empty subsequences so this is the + + align:start position:0% +non-empty subsequences so this is the + + + align:start position:0% +non-empty subsequences so this is the +number of sub-problems + + align:start position:0% +number of sub-problems + + + align:start position:0% +number of sub-problems +and then what we care about is how much + + align:start position:0% +and then what we care about is how much + + + align:start position:0% +and then what we care about is how much +time do we spend for each subproblem in + + align:start position:0% +time do we spend for each subproblem in + + + align:start position:0% +time do we spend for each subproblem in +evaluating this + + align:start position:0% +evaluating this + + + align:start position:0% +evaluating this +recurrence relation so we ignore the + + align:start position:0% +recurrence relation so we ignore the + + + align:start position:0% +recurrence relation so we ignore the +cost to recursively call these l's + + align:start position:0% +cost to recursively call these l's + + + align:start position:0% +cost to recursively call these l's +because + + align:start position:0% +because + + + align:start position:0% +because +they are smaller sub problems they're + + align:start position:0% +they are smaller sub problems they're + + + align:start position:0% +they are smaller sub problems they're +already dealt with when i multiply by + + align:start position:0% +already dealt with when i multiply by + + + align:start position:0% +already dealt with when i multiply by +the number of subproblems + + align:start position:0% +the number of subproblems + + + align:start position:0% +the number of subproblems +so i just care about this max + + align:start position:0% +so i just care about this max + + + align:start position:0% +so i just care about this max +computation and this equality check + + align:start position:0% +computation and this equality check + + + align:start position:0% +computation and this equality check +and we'll say those each cost constant + + align:start position:0% +and we'll say those each cost constant + + + align:start position:0% +and we'll say those each cost constant +time + + align:start position:0% +time + + + align:start position:0% +time +so this is + + align:start position:0% + + + + align:start position:0% + +quadratic time if the two strings are + + align:start position:0% +quadratic time if the two strings are + + + align:start position:0% +quadratic time if the two strings are +size n this is n squared + + align:start position:0% +size n this is n squared + + + align:start position:0% +size n this is n squared +general it's the product of the two + + align:start position:0% +general it's the product of the two + + + align:start position:0% +general it's the product of the two +string sizes + + align:start position:0% +string sizes + + + align:start position:0% +string sizes +and that's longest common substring + + align:start position:0% +and that's longest common substring + + + align:start position:0% +and that's longest common substring +so uh pretty straightforward this really + + align:start position:0% +so uh pretty straightforward this really + + + align:start position:0% +so uh pretty straightforward this really +doesn't + + align:start position:0% +doesn't + + + align:start position:0% +doesn't +other than this little argument and + + align:start position:0% +other than this little argument and + + + align:start position:0% +other than this little argument and +understanding the case when they're + + align:start position:0% +understanding the case when they're + + + align:start position:0% +understanding the case when they're +equal + + align:start position:0% +equal + + + align:start position:0% +equal +the easy case where they're unequal we + + align:start position:0% +the easy case where they're unequal we + + + align:start position:0% +the easy case where they're unequal we +just try the only two things we could do + + align:start position:0% +just try the only two things we could do + + + align:start position:0% +just try the only two things we could do +one of the + + align:start position:0% +one of the + + + align:start position:0% +one of the +uh one of a inbj is not in the longest + + align:start position:0% +uh one of a inbj is not in the longest + + + align:start position:0% +uh one of a inbj is not in the longest +common subsequence + + align:start position:0% +common subsequence + + + align:start position:0% +common subsequence +so what i like to say is we guess which + + align:start position:0% +so what i like to say is we guess which + + + align:start position:0% +so what i like to say is we guess which +of those + + align:start position:0% +of those + + + align:start position:0% +of those +is the correct one that is not in the + + align:start position:0% +is the correct one that is not in the + + + align:start position:0% +is the correct one that is not in the +longest common subsequence + + align:start position:0% +longest common subsequence + + + align:start position:0% +longest common subsequence +and if we guess that it's in a then + + align:start position:0% +and if we guess that it's in a then + + + align:start position:0% +and if we guess that it's in a then +we'll recurse on that side if we guess + + align:start position:0% +we'll recurse on that side if we guess + + + align:start position:0% +we'll recurse on that side if we guess +that it's in j + + align:start position:0% +that it's in j + + + align:start position:0% +that it's in j +then we'll recurse on by increasing j + + align:start position:0% +then we'll recurse on by increasing j + + + align:start position:0% +then we'll recurse on by increasing j +and then uh would i'd like to assume + + align:start position:0% +and then uh would i'd like to assume + + + align:start position:0% +and then uh would i'd like to assume +not really that we always make the + + align:start position:0% +not really that we always make the + + + align:start position:0% +not really that we always make the +correct guess + + align:start position:0% +correct guess + + + align:start position:0% +correct guess +that we made the correct choice whether + + align:start position:0% +that we made the correct choice whether + + + align:start position:0% +that we made the correct choice whether +it's irj now we don't actually know how + + align:start position:0% +it's irj now we don't actually know how + + + align:start position:0% +it's irj now we don't actually know how +to do that so instead we brute force + + align:start position:0% +to do that so instead we brute force + + + align:start position:0% +to do that so instead we brute force +we try both of them and then because + + align:start position:0% +we try both of them and then because + + + align:start position:0% +we try both of them and then because +we're trying to maximize we take the max + + align:start position:0% +we're trying to maximize we take the max + + + align:start position:0% +we're trying to maximize we take the max +okay just another way of thinking about + + align:start position:0% +okay just another way of thinking about + + + align:start position:0% +okay just another way of thinking about +it but + + align:start position:0% +it but + + + align:start position:0% +it but +overall very straightforward the only + + align:start position:0% +overall very straightforward the only + + + align:start position:0% +overall very straightforward the only +com added complication here is we had to + + align:start position:0% +com added complication here is we had to + + + align:start position:0% +com added complication here is we had to +deal with two + + align:start position:0% +deal with two + + + align:start position:0% +deal with two +uh sequences simultaneously and we just + + align:start position:0% +uh sequences simultaneously and we just + + + align:start position:0% +uh sequences simultaneously and we just +took the product of those so pretty + + align:start position:0% +took the product of those so pretty + + + align:start position:0% +took the product of those so pretty +pretty easy in general if you have some + + align:start position:0% +pretty easy in general if you have some + + + align:start position:0% +pretty easy in general if you have some +constant number of sequences you can + + align:start position:0% +constant number of sequences you can + + + align:start position:0% +constant number of sequences you can +afford to do this you'll still get + + align:start position:0% +afford to do this you'll still get + + + align:start position:0% +afford to do this you'll still get +polynomial + + align:start position:0% +polynomial + + + align:start position:0% +polynomial +but of course once you go to end + + align:start position:0% +but of course once you go to end + + + align:start position:0% +but of course once you go to end +sequences you can't afford this you + + align:start position:0% +sequences you can't afford this you + + + align:start position:0% +sequences you can't afford this you +would get like an end to the n + + align:start position:0% +would get like an end to the n + + + align:start position:0% +would get like an end to the n +behavior so that's kind of a limit to + + align:start position:0% +behavior so that's kind of a limit to + + + align:start position:0% +behavior so that's kind of a limit to +how far you could go + + align:start position:0% +how far you could go + + + align:start position:0% +how far you could go +two sequences is fine three sequences is + + align:start position:0% +two sequences is fine three sequences is + + + align:start position:0% +two sequences is fine three sequences is +fine but n sequences + + align:start position:0% +fine but n sequences + + + align:start position:0% +fine but n sequences +there probably is no polynomial time + + align:start position:0% +there probably is no polynomial time + + + align:start position:0% +there probably is no polynomial time +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +for this problem uh cool i want to show + + align:start position:0% +for this problem uh cool i want to show + + + align:start position:0% +for this problem uh cool i want to show +you an example + + align:start position:0% +you an example + + + align:start position:0% +you an example +i have an example here not i didn't + + align:start position:0% +i have an example here not i didn't + + + align:start position:0% +i have an example here not i didn't +i didn't want to try out hieroglyphology + + align:start position:0% +i didn't want to try out hieroglyphology + + + align:start position:0% +i didn't want to try out hieroglyphology +versus michelangelo + + align:start position:0% +versus michelangelo + + + align:start position:0% +versus michelangelo +so i came up with another example their + + align:start position:0% +so i came up with another example their + + + align:start position:0% +so i came up with another example their +habit + + align:start position:0% +habit + + + align:start position:0% +habit +is to say hi so the longest common + + align:start position:0% +is to say hi so the longest common + + + align:start position:0% +is to say hi so the longest common +subsequence of their and habit + + align:start position:0% +subsequence of their and habit + + + align:start position:0% +subsequence of their and habit +is h i um and i mean it's a giant + + align:start position:0% +is h i um and i mean it's a giant + + + align:start position:0% +is h i um and i mean it's a giant +well not that giant it looks kind of + + align:start position:0% +well not that giant it looks kind of + + + align:start position:0% +well not that giant it looks kind of +like a grid graph + + align:start position:0% +like a grid graph + + + align:start position:0% +like a grid graph +the base cases are out here because + + align:start position:0% +the base cases are out here because + + + align:start position:0% +the base cases are out here because +those correspond + + align:start position:0% +those correspond + + + align:start position:0% +those correspond +so uh when i say this each of these + + align:start position:0% +so uh when i say this each of these + + + align:start position:0% +so uh when i say this each of these +nodes is a subproblem and this + + align:start position:0% +nodes is a subproblem and this + + + align:start position:0% +nodes is a subproblem and this +corresponds to what is the longest + + align:start position:0% +corresponds to what is the longest + + + align:start position:0% +corresponds to what is the longest +common + + align:start position:0% +common + + + align:start position:0% +common +subsequence between eir + + align:start position:0% +subsequence between eir + + + align:start position:0% +subsequence between eir +and abbott and it should be i + + align:start position:0% +and abbott and it should be i + + + align:start position:0% +and abbott and it should be i +it's the only letter they have in common + + align:start position:0% +it's the only letter they have in common + + + align:start position:0% +it's the only letter they have in common +and that's why there's a 1 here to say + + align:start position:0% +and that's why there's a 1 here to say + + + align:start position:0% +and that's why there's a 1 here to say +that + + align:start position:0% +that + + + align:start position:0% +that +the longest common subsequence has a 1 + + align:start position:0% +the longest common subsequence has a 1 + + + align:start position:0% +the longest common subsequence has a 1 +has size 1. + + align:start position:0% +has size 1. + + + align:start position:0% +has size 1. +the base cases are when either there has + + align:start position:0% +the base cases are when either there has + + + align:start position:0% +the base cases are when either there has +been emptied + + align:start position:0% +been emptied + + + align:start position:0% +been emptied +or when habit has been emptied so those + + align:start position:0% +or when habit has been emptied so those + + + align:start position:0% +or when habit has been emptied so those +all have zeros + + align:start position:0% +all have zeros + + + align:start position:0% +all have zeros +on the outside and then the problem we + + align:start position:0% +on the outside and then the problem we + + + align:start position:0% +on the outside and then the problem we +care about is this one it's + + align:start position:0% +care about is this one it's + + + align:start position:0% +care about is this one it's +there versus habit uh claim is the + + align:start position:0% +there versus habit uh claim is the + + + align:start position:0% +there versus habit uh claim is the +length is two + + align:start position:0% +length is two + + + align:start position:0% +length is two +and what i've drawn in here are what + + align:start position:0% +and what i've drawn in here are what + + + align:start position:0% +and what i've drawn in here are what +i'll call + + align:start position:0% +i'll call + + + align:start position:0% +i'll call +parent pointers like we talked about + + align:start position:0% +parent pointers like we talked about + + + align:start position:0% +parent pointers like we talked about +with + + align:start position:0% +with + + + align:start position:0% +with +bfs and shortest paths and so on + + align:start position:0% +bfs and shortest paths and so on + + + align:start position:0% +bfs and shortest paths and so on +this is so we had this choice + + align:start position:0% +this is so we had this choice + + + align:start position:0% +this is so we had this choice +uh sometimes we had a choice on whether + + align:start position:0% +uh sometimes we had a choice on whether + + + align:start position:0% +uh sometimes we had a choice on whether +we + + align:start position:0% +we + + + align:start position:0% +we +recursed here or recursed here was the + + align:start position:0% +recursed here or recursed here was the + + + align:start position:0% +recursed here or recursed here was the +best thing to do + + align:start position:0% +best thing to do + + + align:start position:0% +best thing to do +and so i'll just draw i'll draw in red + + align:start position:0% +and so i'll just draw i'll draw in red + + + align:start position:0% +and so i'll just draw i'll draw in red +the arrow from + + align:start position:0% +the arrow from + + + align:start position:0% +the arrow from +lij sorry to lij from one of these + + align:start position:0% +lij sorry to lij from one of these + + + align:start position:0% +lij sorry to lij from one of these +in this case and in this case there's no + + align:start position:0% +in this case and in this case there's no + + + align:start position:0% +in this case and in this case there's no +choice but i'll still draw in red that + + align:start position:0% +choice but i'll still draw in red that + + + align:start position:0% +choice but i'll still draw in red that +arrow + + align:start position:0% + + + + align:start position:0% + +so uh these diagonal edges are exactly + + align:start position:0% +so uh these diagonal edges are exactly + + + align:start position:0% +so uh these diagonal edges are exactly +the cases where the letters match here h + + align:start position:0% +the cases where the letters match here h + + + align:start position:0% +the cases where the letters match here h +equals h um i equals i here so i draw + + align:start position:0% +equals h um i equals i here so i draw + + + align:start position:0% +equals h um i equals i here so i draw +this diagonal edge that's that first + + align:start position:0% +this diagonal edge that's that first + + + align:start position:0% +this diagonal edge that's that first +case where the letters are equal + + align:start position:0% +case where the letters are equal + + + align:start position:0% +case where the letters are equal +and so i recurse by increasing i and j + + align:start position:0% +and so i recurse by increasing i and j + + + align:start position:0% +and so i recurse by increasing i and j +that's why i get a diagonal edge + + align:start position:0% +that's why i get a diagonal edge + + + align:start position:0% +that's why i get a diagonal edge +there's also one over here where t + + align:start position:0% +there's also one over here where t + + + align:start position:0% +there's also one over here where t +equals t + + align:start position:0% + + + + align:start position:0% + +so for those we're getting a one plus + + align:start position:0% +so for those we're getting a one plus + + + align:start position:0% +so for those we're getting a one plus +you see this one is one larger than the + + align:start position:0% +you see this one is one larger than the + + + align:start position:0% +you see this one is one larger than the +zero + + align:start position:0% +zero + + + align:start position:0% +zero +this two is one larger than the one this + + align:start position:0% +this two is one larger than the one this + + + align:start position:0% +this two is one larger than the one this +one is one larger than the zero + + align:start position:0% +one is one larger than the zero + + + align:start position:0% +one is one larger than the zero +and for every other vertex we are + + align:start position:0% +and for every other vertex we are + + + align:start position:0% +and for every other vertex we are +recursing this way and + + align:start position:0% +recursing this way and + + + align:start position:0% +recursing this way and +this way uh we can see what those two + + align:start position:0% +this way uh we can see what those two + + + align:start position:0% +this way uh we can see what those two +numbers are and we take the max + + align:start position:0% +numbers are and we take the max + + + align:start position:0% +numbers are and we take the max +so this whole diagram is just filled in + + align:start position:0% +so this whole diagram is just filled in + + + align:start position:0% +so this whole diagram is just filled in +uh by + + align:start position:0% +uh by + + + align:start position:0% +uh by +for each uh position where they're not + + align:start position:0% +for each uh position where they're not + + + align:start position:0% +for each uh position where they're not +equal + + align:start position:0% +equal + + + align:start position:0% +equal +we look at the guy below we look at the + + align:start position:0% +we look at the guy below we look at the + + + align:start position:0% +we look at the guy below we look at the +guy to the right those are the slightly + + align:start position:0% +guy to the right those are the slightly + + + align:start position:0% +guy to the right those are the slightly +smaller + + align:start position:0% +smaller + + + align:start position:0% +smaller +substrings we look at those values we + + align:start position:0% +substrings we look at those values we + + + align:start position:0% +substrings we look at those values we +take the max + + align:start position:0% +take the max + + + align:start position:0% +take the max +as long as you compute this in a + + align:start position:0% +as long as you compute this in a + + + align:start position:0% +as long as you compute this in a +generally right to left and bottom up + + align:start position:0% +generally right to left and bottom up + + + align:start position:0% +generally right to left and bottom up +fashion + + align:start position:0% +fashion + + + align:start position:0% +fashion +whenever you're trying to compute a guy + + align:start position:0% +whenever you're trying to compute a guy + + + align:start position:0% +whenever you're trying to compute a guy +you will have the its predecessors + + align:start position:0% +you will have the its predecessors + + + align:start position:0% +you will have the its predecessors +already computed that's the topological + + align:start position:0% +already computed that's the topological + + + align:start position:0% +already computed that's the topological +order of this graph + + align:start position:0% +order of this graph + + + align:start position:0% +order of this graph +and then at the end we get our answer + + align:start position:0% +and then at the end we get our answer + + + align:start position:0% +and then at the end we get our answer +which is two and now if we pay attention + + align:start position:0% +which is two and now if we pay attention + + + align:start position:0% +which is two and now if we pay attention +to + + align:start position:0% +to + + + align:start position:0% +to +where we came from for example this + + align:start position:0% +where we came from for example this + + + align:start position:0% +where we came from for example this +vertex had to come from this + + align:start position:0% +vertex had to come from this + + + align:start position:0% +vertex had to come from this +direction the 2 is the max of 2 and 1. + + align:start position:0% +direction the 2 is the max of 2 and 1. + + + align:start position:0% +direction the 2 is the max of 2 and 1. +so i highlight the 2 edge and if i + + align:start position:0% +so i highlight the 2 edge and if i + + + align:start position:0% +so i highlight the 2 edge and if i +follow this path + + align:start position:0% +follow this path + + + align:start position:0% +follow this path +there should be a unique path to some + + align:start position:0% +there should be a unique path to some + + + align:start position:0% +there should be a unique path to some +base case we don't know which one + + align:start position:0% +base case we don't know which one + + + align:start position:0% +base case we don't know which one +and in this case the diagonal edges + + align:start position:0% +and in this case the diagonal edges + + + align:start position:0% +and in this case the diagonal edges +correspond to my + + align:start position:0% +correspond to my + + + align:start position:0% +correspond to my +matching letters so there's the h here + + align:start position:0% +matching letters so there's the h here + + + align:start position:0% +matching letters so there's the h here +and followed by the i here and so high + + align:start position:0% +and followed by the i here and so high + + + align:start position:0% +and followed by the i here and so high +is our longest common substring in + + align:start position:0% +is our longest common substring in + + + align:start position:0% +is our longest common substring in +general we just follow these pointers + + align:start position:0% +general we just follow these pointers + + + align:start position:0% +general we just follow these pointers +backwards + + align:start position:0% +backwards + + + align:start position:0% +backwards +the red pointers and we get our answer + + align:start position:0% +the red pointers and we get our answer + + + align:start position:0% +the red pointers and we get our answer +so not only do we compute + + align:start position:0% +so not only do we compute + + + align:start position:0% +so not only do we compute +the length of the lcs but we actually + + align:start position:0% +the length of the lcs but we actually + + + align:start position:0% +the length of the lcs but we actually +can find the lcs using + + align:start position:0% +can find the lcs using + + + align:start position:0% +can find the lcs using +parent pointers so this is + + align:start position:0% +parent pointers so this is + + + align:start position:0% +parent pointers so this is +and this is a concept you can use in + + align:start position:0% +and this is a concept you can use in + + + align:start position:0% +and this is a concept you can use in +most dynamic programs + + align:start position:0% +most dynamic programs + + + align:start position:0% +most dynamic programs +including all the ones from today okay + + align:start position:0% +including all the ones from today okay + + + align:start position:0% +including all the ones from today okay +any questions about lcs + + align:start position:0% + + + + align:start position:0% + +all right perfectly clear to everyone in + + align:start position:0% +all right perfectly clear to everyone in + + + align:start position:0% +all right perfectly clear to everyone in +the audience + + align:start position:0% +the audience + + + align:start position:0% +the audience +uh so we move oh uh yeah now we move on + + align:start position:0% +uh so we move oh uh yeah now we move on + + + align:start position:0% +uh so we move oh uh yeah now we move on +to + + align:start position:0% +to + + + align:start position:0% +to +longest increasing subsequence which + + align:start position:0% +longest increasing subsequence which + + + align:start position:0% +longest increasing subsequence which +did i lose a page here i just disordered + + align:start position:0% +did i lose a page here i just disordered + + + align:start position:0% +did i lose a page here i just disordered +them + + align:start position:0% + + + + align:start position:0% + +okay this problem has almost the same + + align:start position:0% +okay this problem has almost the same + + + align:start position:0% +okay this problem has almost the same +name but is quite different in behavior + + align:start position:0% +name but is quite different in behavior + + + align:start position:0% +name but is quite different in behavior +longest increasing + + align:start position:0% +longest increasing + + + align:start position:0% +longest increasing +subsequence + + align:start position:0% + + + + align:start position:0% + +l i s instead of lcs + + align:start position:0% + + + + align:start position:0% + +both famous problems examples of dynamic + + align:start position:0% +both famous problems examples of dynamic + + + align:start position:0% +both famous problems examples of dynamic +programming + + align:start position:0% +programming + + + align:start position:0% +programming +here we're just given one sequence + + align:start position:0% + + + + align:start position:0% + +like carbohydrate + + align:start position:0% + + + + align:start position:0% + +so this is a sequence of letters and i + + align:start position:0% +so this is a sequence of letters and i + + + align:start position:0% +so this is a sequence of letters and i +want to find the longest subsequence of + + align:start position:0% +want to find the longest subsequence of + + + align:start position:0% +want to find the longest subsequence of +this sequence + + align:start position:0% +this sequence + + + align:start position:0% +this sequence +that is increasing strictly increasing + + align:start position:0% +that is increasing strictly increasing + + + align:start position:0% +that is increasing strictly increasing +let's say so + + align:start position:0% +let's say so + + + align:start position:0% +let's say so +in this case alphabetically so i could + + align:start position:0% +in this case alphabetically so i could + + + align:start position:0% +in this case alphabetically so i could +go i could include cr for example but + + align:start position:0% +go i could include cr for example but + + + align:start position:0% +go i could include cr for example but +not cb that would be + + align:start position:0% +not cb that would be + + + align:start position:0% +not cb that would be +a descending subsequence and in general + + align:start position:0% +a descending subsequence and in general + + + align:start position:0% +a descending subsequence and in general +or in this example the right answer or a + + align:start position:0% +or in this example the right answer or a + + + align:start position:0% +or in this example the right answer or a +right answer + + align:start position:0% +right answer + + + align:start position:0% +right answer +is abort there aren't very many english + + align:start position:0% +is abort there aren't very many english + + + align:start position:0% +is abort there aren't very many english +words that are increasing but + + align:start position:0% +words that are increasing but + + + align:start position:0% +words that are increasing but +there are some and i looked through all + + align:start position:0% +there are some and i looked through all + + + align:start position:0% +there are some and i looked through all +of them + + align:start position:0% +of them + + + align:start position:0% +of them +because i just implemented this dynamic + + align:start position:0% +because i just implemented this dynamic + + + align:start position:0% +because i just implemented this dynamic +program we're about to + + align:start position:0% +program we're about to + + + align:start position:0% +program we're about to +to write down it take took me like two + + align:start position:0% +to write down it take took me like two + + + align:start position:0% +to write down it take took me like two +minutes to write down the dp and then + + align:start position:0% +minutes to write down the dp and then + + + align:start position:0% +minutes to write down the dp and then +more work to read the dictionary and + + align:start position:0% +more work to read the dictionary and + + + align:start position:0% +more work to read the dictionary and +look for cool examples + + align:start position:0% +look for cool examples + + + align:start position:0% +look for cool examples +so in general we're given some sequence + + align:start position:0% +so in general we're given some sequence + + + align:start position:0% +so in general we're given some sequence +a + + align:start position:0% + + + + align:start position:0% + +and we want to find the longest + + align:start position:0% +and we want to find the longest + + + align:start position:0% +and we want to find the longest +increasing subsequence of + + align:start position:0% +increasing subsequence of + + + align:start position:0% +increasing subsequence of +a the longest sequence that is + + align:start position:0% +a the longest sequence that is + + + align:start position:0% +a the longest sequence that is +increasing + + align:start position:0% + + + + align:start position:0% + +strictly + + align:start position:0% + + + + align:start position:0% + +you we could use the same thing to solve + + align:start position:0% +you we could use the same thing to solve + + + align:start position:0% +you we could use the same thing to solve +not strictly increasing but + + align:start position:0% + + + + align:start position:0% + +so here uh things are going to be a + + align:start position:0% +so here uh things are going to be a + + + align:start position:0% +so here uh things are going to be a +little trickier it's easy in that we + + align:start position:0% +little trickier it's easy in that we + + + align:start position:0% +little trickier it's easy in that we +just have a single sequence so again we + + align:start position:0% +just have a single sequence so again we + + + align:start position:0% +just have a single sequence so again we +think + + align:start position:0% +think + + + align:start position:0% +think +okay let's look at our chart here we + + align:start position:0% +okay let's look at our chart here we + + + align:start position:0% +okay let's look at our chart here we +could try prefixes suffixes or + + align:start position:0% +could try prefixes suffixes or + + + align:start position:0% +could try prefixes suffixes or +substrings i personally prefer + + align:start position:0% +substrings i personally prefer + + + align:start position:0% +substrings i personally prefer +suffixes jason prefers prefixes uh + + align:start position:0% +suffixes jason prefers prefixes uh + + + align:start position:0% +suffixes jason prefers prefixes uh +whatever you prefer is fine + + align:start position:0% +whatever you prefer is fine + + + align:start position:0% +whatever you prefer is fine +um but always i'll generally start there + + align:start position:0% +um but always i'll generally start there + + + align:start position:0% +um but always i'll generally start there +because there's nothing in this problem + + align:start position:0% +because there's nothing in this problem + + + align:start position:0% +because there's nothing in this problem +that makes me think i need to + + align:start position:0% +that makes me think i need to + + + align:start position:0% +that makes me think i need to +delete things from both ends one yeah + + align:start position:0% +delete things from both ends one yeah + + + align:start position:0% +delete things from both ends one yeah +question isn't the answer to this + + align:start position:0% +question isn't the answer to this + + + align:start position:0% +question isn't the answer to this +problem always 26. + + align:start position:0% +problem always 26. + + + align:start position:0% +problem always 26. +so if is the ques is the answer always + + align:start position:0% +so if is the ques is the answer always + + + align:start position:0% +so if is the ques is the answer always +at most 26 + + align:start position:0% +at most 26 + + + align:start position:0% +at most 26 +yes if you're dealing with english words + + align:start position:0% +yes if you're dealing with english words + + + align:start position:0% +yes if you're dealing with english words +so + + align:start position:0% +so + + + align:start position:0% +so +when i say sequence here this is a + + align:start position:0% +when i say sequence here this is a + + + align:start position:0% +when i say sequence here this is a +sequence of arbitrary integers + + align:start position:0% +sequence of arbitrary integers + + + align:start position:0% +sequence of arbitrary integers +word size integers so there you can have + + align:start position:0% +word size integers so there you can have + + + align:start position:0% +word size integers so there you can have +a ton of variety this is just for the + + align:start position:0% +a ton of variety this is just for the + + + align:start position:0% +a ton of variety this is just for the +fun of examples + + align:start position:0% +fun of examples + + + align:start position:0% +fun of examples +i've drawn drawn this but even if the + + align:start position:0% +i've drawn drawn this but even if the + + + align:start position:0% +i've drawn drawn this but even if the +answer is 26 finding that longest common + + align:start position:0% +answer is 26 finding that longest common + + + align:start position:0% +answer is 26 finding that longest common +subsequence is + + align:start position:0% +subsequence is + + + align:start position:0% +subsequence is +you know the obvious algorithm would be + + align:start position:0% +you know the obvious algorithm would be + + + align:start position:0% +you know the obvious algorithm would be +to take all sub + + align:start position:0% +to take all sub + + + align:start position:0% +to take all sub +strings of size 26 which is like n to + + align:start position:0% +strings of size 26 which is like n to + + + align:start position:0% +strings of size 26 which is like n to +the 26 + + align:start position:0% +the 26 + + + align:start position:0% +the 26 +so that's we're going to do much faster + + align:start position:0% +so that's we're going to do much faster + + + align:start position:0% +so that's we're going to do much faster +than that here and squared time + + align:start position:0% +than that here and squared time + + + align:start position:0% +than that here and squared time +and then if you remove the strictly + + align:start position:0% +and then if you remove the strictly + + + align:start position:0% +and then if you remove the strictly +increasing + + align:start position:0% +increasing + + + align:start position:0% +increasing +then it can be arbitrarily large + + align:start position:0% +then it can be arbitrarily large + + + align:start position:0% +then it can be arbitrarily large +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +let's try to do this uh + + align:start position:0% +let's try to do this uh + + + align:start position:0% +let's try to do this uh +maybe i won't be so pessimistic to write + + align:start position:0% +maybe i won't be so pessimistic to write + + + align:start position:0% +maybe i won't be so pessimistic to write +attempt here + + align:start position:0% +attempt here + + + align:start position:0% +attempt here +let's just go for it uh + + align:start position:0% +let's just go for it uh + + + align:start position:0% +let's just go for it uh +so i want some sub problems and i'm + + align:start position:0% +so i want some sub problems and i'm + + + align:start position:0% +so i want some sub problems and i'm +going to choose suffixes + + align:start position:0% +going to choose suffixes + + + align:start position:0% +going to choose suffixes +so i'm going to define l of i to be the + + align:start position:0% +so i'm going to define l of i to be the + + + align:start position:0% +so i'm going to define l of i to be the +longest increasing subsequence + + align:start position:0% +longest increasing subsequence + + + align:start position:0% +longest increasing subsequence +of the suffix of a starting at i + + align:start position:0% +of the suffix of a starting at i + + + align:start position:0% +of the suffix of a starting at i +okay that's the obvious thing to do uh + + align:start position:0% +okay that's the obvious thing to do uh + + + align:start position:0% +okay that's the obvious thing to do uh +and now i'm gonna leave myself a little + + align:start position:0% +and now i'm gonna leave myself a little + + + align:start position:0% +and now i'm gonna leave myself a little +space and then i'd like + + align:start position:0% +space and then i'd like + + + align:start position:0% +space and then i'd like +a relation on these + + align:start position:0% +a relation on these + + + align:start position:0% +a relation on these +so i'd like to say what l of i is + + align:start position:0% +so i'd like to say what l of i is + + + align:start position:0% +so i'd like to say what l of i is +and what do i have to work with well i + + align:start position:0% +and what do i have to work with well i + + + align:start position:0% +and what do i have to work with well i +have l of things larger than i + + align:start position:0% +have l of things larger than i + + + align:start position:0% +have l of things larger than i +those would be smaller suffixes + + align:start position:0% +those would be smaller suffixes + + + align:start position:0% +those would be smaller suffixes +uh but let's let's go back to what is a + + align:start position:0% +uh but let's let's go back to what is a + + + align:start position:0% +uh but let's let's go back to what is a +question + + align:start position:0% +question + + + align:start position:0% +question +that i could ask about this sub problem + + align:start position:0% +that i could ask about this sub problem + + + align:start position:0% +that i could ask about this sub problem +that might + + align:start position:0% +that might + + + align:start position:0% +that might +help me figure out what the longest + + align:start position:0% +help me figure out what the longest + + + align:start position:0% +help me figure out what the longest +increasing subsequence looks like + + align:start position:0% +increasing subsequence looks like + + + align:start position:0% +increasing subsequence looks like +so we're looking at a + + align:start position:0% + + + + align:start position:0% + +here's a from i on + + align:start position:0% +here's a from i on + + + align:start position:0% +here's a from i on +longest increasing subsequence is sub + + align:start position:0% +longest increasing subsequence is sub + + + align:start position:0% +longest increasing subsequence is sub +subsequence and we'd like to remove + + align:start position:0% +subsequence and we'd like to remove + + + align:start position:0% +subsequence and we'd like to remove +letter i now when we do that there are + + align:start position:0% +letter i now when we do that there are + + + align:start position:0% +letter i now when we do that there are +two choices maybe i + + align:start position:0% +two choices maybe i + + + align:start position:0% +two choices maybe i +is in the longest increasing subsequence + + align:start position:0% +is in the longest increasing subsequence + + + align:start position:0% +is in the longest increasing subsequence +or it's not in + + align:start position:0% +or it's not in + + + align:start position:0% +or it's not in +so the question i would like to answer + + align:start position:0% +so the question i would like to answer + + + align:start position:0% +so the question i would like to answer +is + + align:start position:0% +is + + + align:start position:0% +is +is i in the longest increasing + + align:start position:0% +is i in the longest increasing + + + align:start position:0% +is i in the longest increasing +subsequence of a + + align:start position:0% +subsequence of a + + + align:start position:0% +subsequence of a +of a from i onwards + + align:start position:0% + + + + align:start position:0% + +this is a binary question there are two + + align:start position:0% +this is a binary question there are two + + + align:start position:0% +this is a binary question there are two +options so again just like before + + align:start position:0% +options so again just like before + + + align:start position:0% +options so again just like before +and so i can brute force those two + + align:start position:0% +and so i can brute force those two + + + align:start position:0% +and so i can brute force those two +options + + align:start position:0% +options + + + align:start position:0% +options +the trouble and then i want the longest + + align:start position:0% +the trouble and then i want the longest + + + align:start position:0% +the trouble and then i want the longest +one so i'm going to take the max + + align:start position:0% +one so i'm going to take the max + + + align:start position:0% +one so i'm going to take the max +so i'd like to take the max of something + + align:start position:0% +so i'd like to take the max of something + + + align:start position:0% +so i'd like to take the max of something +like + + align:start position:0% +like + + + align:start position:0% +like +li plus one so in the case that i don't + + align:start position:0% +li plus one so in the case that i don't + + + align:start position:0% +li plus one so in the case that i don't +put i in the solution that's that's fine + + align:start position:0% +put i in the solution that's that's fine + + + align:start position:0% +put i in the solution that's that's fine +then i just look at + + align:start position:0% +then i just look at + + + align:start position:0% +then i just look at +i plus 1 on and recursively compute that + + align:start position:0% +i plus 1 on and recursively compute that + + + align:start position:0% +i plus 1 on and recursively compute that +and that would be my answer + + align:start position:0% +and that would be my answer + + + align:start position:0% +and that would be my answer +and the other option is that i do put i + + align:start position:0% +and the other option is that i do put i + + + align:start position:0% +and the other option is that i do put i +in the longest increasing subsequence so + + align:start position:0% +in the longest increasing subsequence so + + + align:start position:0% +in the longest increasing subsequence so +i do 1 + + align:start position:0% +i do 1 + + + align:start position:0% +i do 1 +plus the rest + + align:start position:0% +plus the rest + + + align:start position:0% +plus the rest +no i plus 1. okay if i if i close this + + align:start position:0% +no i plus 1. okay if i if i close this + + + align:start position:0% +no i plus 1. okay if i if i close this +brace + + align:start position:0% +brace + + + align:start position:0% +brace +this would be a very strange recurrence + + align:start position:0% +this would be a very strange recurrence + + + align:start position:0% +this would be a very strange recurrence +right because this is always bigger than + + align:start position:0% +right because this is always bigger than + + + align:start position:0% +right because this is always bigger than +this one + + align:start position:0% +this one + + + align:start position:0% +this one +so this there's something wrong here and + + align:start position:0% +so this there's something wrong here and + + + align:start position:0% +so this there's something wrong here and +there's something wrong + + align:start position:0% +there's something wrong + + + align:start position:0% +there's something wrong +is i haven't enforced increasing at all + + align:start position:0% +is i haven't enforced increasing at all + + + align:start position:0% +is i haven't enforced increasing at all +there's no constraints here it's just + + align:start position:0% +there's no constraints here it's just + + + align:start position:0% +there's no constraints here it's just +saying well i'll put i in + + align:start position:0% +saying well i'll put i in + + + align:start position:0% +saying well i'll put i in +and then i'll do whatever remains and + + align:start position:0% +and then i'll do whatever remains and + + + align:start position:0% +and then i'll do whatever remains and +i'll pray that that's increasing + + align:start position:0% +i'll pray that that's increasing + + + align:start position:0% +i'll pray that that's increasing +probably won't be because indeed if + + align:start position:0% +probably won't be because indeed if + + + align:start position:0% +probably won't be because indeed if +if i is a letter or as a number that is + + align:start position:0% +if i is a letter or as a number that is + + + align:start position:0% +if i is a letter or as a number that is +strictly + + align:start position:0% +strictly + + + align:start position:0% +strictly +greater than i plus 1 then this will be + + align:start position:0% +greater than i plus 1 then this will be + + + align:start position:0% +greater than i plus 1 then this will be +wrong so i really + + align:start position:0% +wrong so i really + + + align:start position:0% +wrong so i really +can't always do this i need to somehow + + align:start position:0% +can't always do this i need to somehow + + + align:start position:0% +can't always do this i need to somehow +know + + align:start position:0% +know + + + align:start position:0% +know +i could check whether i plus one is is + + align:start position:0% +i could check whether i plus one is is + + + align:start position:0% +i could check whether i plus one is is +in the answer but some but i don't know + + align:start position:0% +in the answer but some but i don't know + + + align:start position:0% +in the answer but some but i don't know +maybe i plus one + + align:start position:0% +maybe i plus one + + + align:start position:0% +maybe i plus one +so i can check whether i the letter i is + + align:start position:0% +so i can check whether i the letter i is + + + align:start position:0% +so i can check whether i the letter i is +less than the letter i plus one + + align:start position:0% +less than the letter i plus one + + + align:start position:0% +less than the letter i plus one +uh but maybe i put this in the longest + + align:start position:0% +uh but maybe i put this in the longest + + + align:start position:0% +uh but maybe i put this in the longest +increasing subsequence then i put this + + align:start position:0% +increasing subsequence then i put this + + + align:start position:0% +increasing subsequence then i put this +in the longest increasing subsequence + + align:start position:0% +in the longest increasing subsequence + + + align:start position:0% +in the longest increasing subsequence +and so i need to compare these two items + + align:start position:0% +and so i need to compare these two items + + + align:start position:0% +and so i need to compare these two items +but i don't know when that's going to + + align:start position:0% +but i don't know when that's going to + + + align:start position:0% +but i don't know when that's going to +happen + + align:start position:0% +happen + + + align:start position:0% +happen +things seem really hard and indeed + + align:start position:0% +things seem really hard and indeed + + + align:start position:0% +things seem really hard and indeed +there's no + + align:start position:0% +there's no + + + align:start position:0% +there's no +way from this sub problem definition to + + align:start position:0% +way from this sub problem definition to + + + align:start position:0% +way from this sub problem definition to +write down a relation + + align:start position:0% +write down a relation + + + align:start position:0% +write down a relation +but there is a slight tweak to this + + align:start position:0% +but there is a slight tweak to this + + + align:start position:0% +but there is a slight tweak to this +definition + + align:start position:0% +definition + + + align:start position:0% +definition +that makes it work so um + + align:start position:0% +that makes it work so um + + + align:start position:0% +that makes it work so um +the the trouble we have here and this is + + align:start position:0% +the the trouble we have here and this is + + + align:start position:0% +the the trouble we have here and this is +the idea of sub problem + + align:start position:0% +the idea of sub problem + + + align:start position:0% +the idea of sub problem +constraints or conditions the trouble + + align:start position:0% +constraints or conditions the trouble + + + align:start position:0% +constraints or conditions the trouble +we have is when when we recursively + + align:start position:0% +we have is when when we recursively + + + align:start position:0% +we have is when when we recursively +compute the + + align:start position:0% +compute the + + + align:start position:0% +compute the +longest increasing subsequence on the + + align:start position:0% +longest increasing subsequence on the + + + align:start position:0% +longest increasing subsequence on the +remainder we don't know + + align:start position:0% +remainder we don't know + + + align:start position:0% +remainder we don't know +the first item in that answer + + align:start position:0% +the first item in that answer + + + align:start position:0% +the first item in that answer +maybe it's i plus one maybe it's some + + align:start position:0% +maybe it's i plus one maybe it's some + + + align:start position:0% +maybe it's i plus one maybe it's some +guy over here if we knew who it was then + + align:start position:0% +guy over here if we knew who it was then + + + align:start position:0% +guy over here if we knew who it was then +we could compare that item to + + align:start position:0% +we could compare that item to + + + align:start position:0% +we could compare that item to +item i and so what we'd like to do is + + align:start position:0% +item i and so what we'd like to do is + + + align:start position:0% +item i and so what we'd like to do is +add a constraint to this sub-problem + + align:start position:0% +add a constraint to this sub-problem + + + align:start position:0% +add a constraint to this sub-problem +that somehow + + align:start position:0% +that somehow + + + align:start position:0% +that somehow +lets us know where the longest + + align:start position:0% +lets us know where the longest + + + align:start position:0% +lets us know where the longest +increasing subsequence starts + + align:start position:0% +increasing subsequence starts + + + align:start position:0% +increasing subsequence starts +so what i would like to say is longest + + align:start position:0% +so what i would like to say is longest + + + align:start position:0% +so what i would like to say is longest +increasing subsequence of that suffix + + align:start position:0% +increasing subsequence of that suffix + + + align:start position:0% +increasing subsequence of that suffix +that starts + + align:start position:0% + + + + align:start position:0% + +with a of i + + align:start position:0% +with a of i + + + align:start position:0% +with a of i +so in other words it includes + + align:start position:0% +so in other words it includes + + + align:start position:0% +so in other words it includes +a of i + + align:start position:0% + + + + align:start position:0% + +okay this was a separate question + + align:start position:0% + + + + align:start position:0% + +okay this is a bit of a funny constraint + + align:start position:0% +okay this is a bit of a funny constraint + + + align:start position:0% +okay this is a bit of a funny constraint +it changes the problem + + align:start position:0% +it changes the problem + + + align:start position:0% +it changes the problem +it's no longer what we want to solve if + + align:start position:0% +it's no longer what we want to solve if + + + align:start position:0% +it's no longer what we want to solve if +you think about the original problem + + align:start position:0% + + + + align:start position:0% + +before it was solving l of 0 we just + + align:start position:0% +before it was solving l of 0 we just + + + align:start position:0% +before it was solving l of 0 we just +want the longest increasing subsequence + + align:start position:0% +want the longest increasing subsequence + + + align:start position:0% +want the longest increasing subsequence +of the whole thing + + align:start position:0% +of the whole thing + + + align:start position:0% +of the whole thing +now it's not necessarily l of zero this + + align:start position:0% +now it's not necessarily l of zero this + + + align:start position:0% +now it's not necessarily l of zero this +would be l of zero means what is the + + align:start position:0% +would be l of zero means what is the + + + align:start position:0% +would be l of zero means what is the +longest increasing subsequence of the + + align:start position:0% +longest increasing subsequence of the + + + align:start position:0% +longest increasing subsequence of the +whole + + align:start position:0% +whole + + + align:start position:0% +whole +of the whole sequence a that includes + + align:start position:0% +of the whole sequence a that includes + + + align:start position:0% +of the whole sequence a that includes +the first letter of a + + align:start position:0% +the first letter of a + + + align:start position:0% +the first letter of a +and maybe we do include the first letter + + align:start position:0% +and maybe we do include the first letter + + + align:start position:0% +and maybe we do include the first letter +of a maybe we don't we don't + + align:start position:0% +of a maybe we don't we don't + + + align:start position:0% +of a maybe we don't we don't +know where the longest increasing + + align:start position:0% +know where the longest increasing + + + align:start position:0% +know where the longest increasing +subsequence starts here for example it + + align:start position:0% +subsequence starts here for example it + + + align:start position:0% +subsequence starts here for example it +didn't it started at the second letter + + align:start position:0% +didn't it started at the second letter + + + align:start position:0% +didn't it started at the second letter +but conveniently it's okay that we don't + + align:start position:0% +but conveniently it's okay that we don't + + + align:start position:0% +but conveniently it's okay that we don't +know + + align:start position:0% +know + + + align:start position:0% +know +because that's just another question we + + align:start position:0% +because that's just another question we + + + align:start position:0% +because that's just another question we +could ask + + align:start position:0% +could ask + + + align:start position:0% +could ask +is where do we start where might the lis + + align:start position:0% +is where do we start where might the lis + + + align:start position:0% +is where do we start where might the lis +start + + align:start position:0% +start + + + align:start position:0% +start +to start at the first letter second + + align:start position:0% +to start at the first letter second + + + align:start position:0% +to start at the first letter second +letter third letter there's only n + + align:start position:0% +letter third letter there's only n + + + align:start position:0% +letter third letter there's only n +choices + + align:start position:0% +choices + + + align:start position:0% +choices +and let's just take the max of all of + + align:start position:0% +and let's just take the max of all of + + + align:start position:0% +and let's just take the max of all of +them so before i get to the relation + + align:start position:0% +them so before i get to the relation + + + align:start position:0% +them so before i get to the relation +let's solve this problem + + align:start position:0% +let's solve this problem + + + align:start position:0% +let's solve this problem +i just want the max of l i + + align:start position:0% +i just want the max of l i + + + align:start position:0% +i just want the max of l i +for all i + + align:start position:0% + + + + align:start position:0% + +i guess we've been writing size of a + + align:start position:0% +i guess we've been writing size of a + + + align:start position:0% +i guess we've been writing size of a +here + + align:start position:0% + + + + align:start position:0% + +okay the maximum will beat the overall + + align:start position:0% +okay the maximum will beat the overall + + + align:start position:0% +okay the maximum will beat the overall +longest increasing subsequence so if i + + align:start position:0% +longest increasing subsequence so if i + + + align:start position:0% +longest increasing subsequence so if i +could find longest increasing + + align:start position:0% +could find longest increasing + + + align:start position:0% +could find longest increasing +subsequence that includes the first + + align:start position:0% +subsequence that includes the first + + + align:start position:0% +subsequence that includes the first +letter + + align:start position:0% +letter + + + align:start position:0% +letter +and or the longest one that's includes + + align:start position:0% +and or the longest one that's includes + + + align:start position:0% +and or the longest one that's includes +the second letter and so on + + align:start position:0% +the second letter and so on + + + align:start position:0% +the second letter and so on +so it starts at the first letter starts + + align:start position:0% +so it starts at the first letter starts + + + align:start position:0% +so it starts at the first letter starts +the second letter then + + align:start position:0% +the second letter then + + + align:start position:0% +the second letter then +this max will be the longest overall so + + align:start position:0% +this max will be the longest overall so + + + align:start position:0% +this max will be the longest overall so +if i could this sub problem is not what + + align:start position:0% +if i could this sub problem is not what + + + align:start position:0% +if i could this sub problem is not what +i really wanted but it's still good + + align:start position:0% +i really wanted but it's still good + + + align:start position:0% +i really wanted but it's still good +enough because it lets me + + align:start position:0% +enough because it lets me + + + align:start position:0% +enough because it lets me +solve my original problem and this is + + align:start position:0% +solve my original problem and this is + + + align:start position:0% +solve my original problem and this is +adding an extra constraint + + align:start position:0% +adding an extra constraint + + + align:start position:0% +adding an extra constraint +to my sub problem and doing this is + + align:start position:0% +to my sub problem and doing this is + + + align:start position:0% +to my sub problem and doing this is +challenging thinking about what the + + align:start position:0% +challenging thinking about what the + + + align:start position:0% +challenging thinking about what the +right constraint that would let you + + align:start position:0% +right constraint that would let you + + + align:start position:0% +right constraint that would let you +solve your problem is tricky especially + + align:start position:0% +solve your problem is tricky especially + + + align:start position:0% +solve your problem is tricky especially +in the beginning + + align:start position:0% +in the beginning + + + align:start position:0% +in the beginning +but for now let's just take this as a + + align:start position:0% +but for now let's just take this as a + + + align:start position:0% +but for now let's just take this as a +thing that works why does it work + + align:start position:0% +thing that works why does it work + + + align:start position:0% +thing that works why does it work +because now i can say well + + align:start position:0% +because now i can say well + + + align:start position:0% +because now i can say well +this this term was fine max so i'm + + align:start position:0% +this this term was fine max so i'm + + + align:start position:0% +this this term was fine max so i'm +trying to write + + align:start position:0% +trying to write + + + align:start position:0% +trying to write +longest increasing subsequence starting + + align:start position:0% +longest increasing subsequence starting + + + align:start position:0% +longest increasing subsequence starting +with the ith letter + + align:start position:0% +with the ith letter + + + align:start position:0% +with the ith letter +versus uh + + align:start position:0% +versus uh + + + align:start position:0% +versus uh +yeah actually no this is just going to + + align:start position:0% +yeah actually no this is just going to + + + align:start position:0% +yeah actually no this is just going to +be different + + align:start position:0% + + + + align:start position:0% + +okay so now i get to the central issue + + align:start position:0% +okay so now i get to the central issue + + + align:start position:0% +okay so now i get to the central issue +which is + + align:start position:0% +which is + + + align:start position:0% +which is +i i know by the definition of l i that + + align:start position:0% +i i know by the definition of l i that + + + align:start position:0% +i i know by the definition of l i that +i include letter i this is going to be + + align:start position:0% +i include letter i this is going to be + + + align:start position:0% +i include letter i this is going to be +in my longest increasing subsequence + + align:start position:0% +in my longest increasing subsequence + + + align:start position:0% +in my longest increasing subsequence +that's what i'm looking for + + align:start position:0% +that's what i'm looking for + + + align:start position:0% +that's what i'm looking for +by this definition but i don't know what + + align:start position:0% +by this definition but i don't know what + + + align:start position:0% +by this definition but i don't know what +the second letter is + + align:start position:0% +the second letter is + + + align:start position:0% +the second letter is +could be i plus one could be i plus two + + align:start position:0% +could be i plus one could be i plus two + + + align:start position:0% +could be i plus one could be i plus two +could be anything bigger + + align:start position:0% +could be anything bigger + + + align:start position:0% +could be anything bigger +whenever there's something i don't know + + align:start position:0% +whenever there's something i don't know + + + align:start position:0% +whenever there's something i don't know +i'll just brute force it + + align:start position:0% +i'll just brute force it + + + align:start position:0% +i'll just brute force it +right i don't care uh that i don't know + + align:start position:0% +right i don't care uh that i don't know + + + align:start position:0% +right i don't care uh that i don't know +i'll just take a max over all the + + align:start position:0% +i'll just take a max over all the + + + align:start position:0% +i'll just take a max over all the +possible choices let's say that the next + + align:start position:0% +possible choices let's say that the next + + + align:start position:0% +possible choices let's say that the next +the next letter included in the longest + + align:start position:0% +the next letter included in the longest + + + align:start position:0% +the next letter included in the longest +increasing subsequence i + + align:start position:0% +increasing subsequence i + + + align:start position:0% +increasing subsequence i +is j then i would like to look at + + align:start position:0% +is j then i would like to look at + + + align:start position:0% +is j then i would like to look at +l of j now i don't know what j + + align:start position:0% +l of j now i don't know what j + + + align:start position:0% +l of j now i don't know what j +is but i'll just brute force all + + align:start position:0% +is but i'll just brute force all + + + align:start position:0% +is but i'll just brute force all +possible choices for j so it's going to + + align:start position:0% +possible choices for j so it's going to + + + align:start position:0% +possible choices for j so it's going to +be i + + align:start position:0% +be i + + + align:start position:0% +be i +strictly less than j because i don't + + align:start position:0% +strictly less than j because i don't + + + align:start position:0% +strictly less than j because i don't +want to include the same letter + + align:start position:0% +want to include the same letter + + + align:start position:0% +want to include the same letter +i again and otherwise i would get an + + align:start position:0% +i again and otherwise i would get an + + + align:start position:0% +i again and otherwise i would get an +infinite recursive loop if i put less + + align:start position:0% +infinite recursive loop if i put less + + + align:start position:0% +infinite recursive loop if i put less +than or equal to here + + align:start position:0% +than or equal to here + + + align:start position:0% +than or equal to here +uh and maybe i don't do anything else up + + align:start position:0% +uh and maybe i don't do anything else up + + + align:start position:0% +uh and maybe i don't do anything else up +to n + + align:start position:0% +to n + + + align:start position:0% +to n +and uh okay not quite done + + align:start position:0% + + + + align:start position:0% + +now this is the interesting part i can + + align:start position:0% +now this is the interesting part i can + + + align:start position:0% +now this is the interesting part i can +enforce + + align:start position:0% +enforce + + + align:start position:0% +enforce +increasing because i can't just choose + + align:start position:0% +increasing because i can't just choose + + + align:start position:0% +increasing because i can't just choose +any letter + + align:start position:0% +any letter + + + align:start position:0% +any letter +j to the right of i also the the + + align:start position:0% +j to the right of i also the the + + + align:start position:0% +j to the right of i also the the +number that's or letter that's written + + align:start position:0% +number that's or letter that's written + + + align:start position:0% +number that's or letter that's written +in here has to be greater than the + + align:start position:0% +in here has to be greater than the + + + align:start position:0% +in here has to be greater than the +number that's written here that's the + + align:start position:0% +number that's written here that's the + + + align:start position:0% +number that's written here that's the +strictly increasing property + + align:start position:0% +strictly increasing property + + + align:start position:0% +strictly increasing property +so i can add as a constraint + + align:start position:0% +so i can add as a constraint + + + align:start position:0% +so i can add as a constraint +in this max to say + + align:start position:0% +in this max to say + + + align:start position:0% +in this max to say +a of i is strictly less than a of j + + align:start position:0% +a of i is strictly less than a of j + + + align:start position:0% +a of i is strictly less than a of j +and if you wanted non-strictly + + align:start position:0% +and if you wanted non-strictly + + + align:start position:0% +and if you wanted non-strictly +increasing you would add an + + align:start position:0% +increasing you would add an + + + align:start position:0% +increasing you would add an +equal there okay this is mathematical + + align:start position:0% +equal there okay this is mathematical + + + align:start position:0% +equal there okay this is mathematical +notation in python you would say + + align:start position:0% +notation in python you would say + + + align:start position:0% +notation in python you would say +max open paren of this thing for + + align:start position:0% +max open paren of this thing for + + + align:start position:0% +max open paren of this thing for +j in this range if this holds + + align:start position:0% +j in this range if this holds + + + align:start position:0% +j in this range if this holds +so i'm just doing the for loop but i + + align:start position:0% +so i'm just doing the for loop but i + + + align:start position:0% +so i'm just doing the for loop but i +only do + + align:start position:0% +only do + + + align:start position:0% +only do +i only look at the possible choices for + + align:start position:0% +i only look at the possible choices for + + + align:start position:0% +i only look at the possible choices for +j + + align:start position:0% +j + + + align:start position:0% +j +uh when uh the strict increasing + + align:start position:0% +uh when uh the strict increasing + + + align:start position:0% +uh when uh the strict increasing +property holds + + align:start position:0% +property holds + + + align:start position:0% +property holds +and then when that holds i put check + + align:start position:0% +and then when that holds i put check + + + align:start position:0% +and then when that holds i put check +this now this set might be empty + + align:start position:0% +this now this set might be empty + + + align:start position:0% +this now this set might be empty +i need to define what the max is when + + align:start position:0% +i need to define what the max is when + + + align:start position:0% +i need to define what the max is when +it's empty then i will just + + align:start position:0% +it's empty then i will just + + + align:start position:0% +it's empty then i will just +say oh i also need a oneplus don't i + + align:start position:0% + + + + align:start position:0% + +let me just do one plus so we're told + + align:start position:0% +let me just do one plus so we're told + + + align:start position:0% +let me just do one plus so we're told +that i is in the answer so we always get + + align:start position:0% +that i is in the answer so we always get + + + align:start position:0% +that i is in the answer so we always get +one + + align:start position:0% +one + + + align:start position:0% +one +and then the remainder is this or + + align:start position:0% +and then the remainder is this or + + + align:start position:0% +and then the remainder is this or +zero if there are no uh + + align:start position:0% +zero if there are no uh + + + align:start position:0% +zero if there are no uh +j's there if there are no aj's greater + + align:start position:0% +j's there if there are no aj's greater + + + align:start position:0% +j's there if there are no aj's greater +than a i + + align:start position:0% +than a i + + + align:start position:0% +than a i +uh then we'll default to zero and say + + align:start position:0% +uh then we'll default to zero and say + + + align:start position:0% +uh then we'll default to zero and say +that i is the only item in my increasing + + align:start position:0% +that i is the only item in my increasing + + + align:start position:0% +that i is the only item in my increasing +subsequence + + align:start position:0% +subsequence + + + align:start position:0% +subsequence +okay so there are a few details to get + + align:start position:0% +okay so there are a few details to get + + + align:start position:0% +okay so there are a few details to get +right but in general once + + align:start position:0% +right but in general once + + + align:start position:0% +right but in general once +once you figure out what these + + align:start position:0% +once you figure out what these + + + align:start position:0% +once you figure out what these +recurrences look like they're very + + align:start position:0% +recurrences look like they're very + + + align:start position:0% +recurrences look like they're very +simple i mean this is one line of code + + align:start position:0% +simple i mean this is one line of code + + + align:start position:0% +simple i mean this is one line of code +and then all you need in addition to + + align:start position:0% +and then all you need in addition to + + + align:start position:0% +and then all you need in addition to +this + + align:start position:0% +this + + + align:start position:0% +this +is the original subproblem and some + + align:start position:0% +is the original subproblem and some + + + align:start position:0% +is the original subproblem and some +other + + align:start position:0% +other + + + align:start position:0% +other +things we need the + + align:start position:0% + + + + align:start position:0% + +base cases but i should do them in order + + align:start position:0% +base cases but i should do them in order + + + align:start position:0% +base cases but i should do them in order +topological order + + align:start position:0% + + + + align:start position:0% + +is just the usual for loop because i'm + + align:start position:0% +is just the usual for loop because i'm + + + align:start position:0% +is just the usual for loop because i'm +doing suffixes + + align:start position:0% +doing suffixes + + + align:start position:0% +doing suffixes +it's going to be i equals length of a + + align:start position:0% +it's going to be i equals length of a + + + align:start position:0% +it's going to be i equals length of a +down to zero + + align:start position:0% +down to zero + + + align:start position:0% +down to zero +uh base case is going to be + + align:start position:0% +uh base case is going to be + + + align:start position:0% +uh base case is going to be +l of length of a which is zero + + align:start position:0% +l of length of a which is zero + + + align:start position:0% +l of length of a which is zero +because there's no letters in that + + align:start position:0% +because there's no letters in that + + + align:start position:0% +because there's no letters in that +suffix + + align:start position:0% +suffix + + + align:start position:0% +suffix +um and we already did o and then time + + align:start position:0% +um and we already did o and then time + + + align:start position:0% +um and we already did o and then time +okay this is a little different from the + + align:start position:0% +okay this is a little different from the + + + align:start position:0% +okay this is a little different from the +past examples so number of subproblems + + align:start position:0% +past examples so number of subproblems + + + align:start position:0% +past examples so number of subproblems +just like usual is + + align:start position:0% +just like usual is + + + align:start position:0% +just like usual is +linear length of a + + align:start position:0% +linear length of a + + + align:start position:0% +linear length of a +sub problems + + align:start position:0% + + + + align:start position:0% + +there's only one sequence we're thinking + + align:start position:0% +there's only one sequence we're thinking + + + align:start position:0% +there's only one sequence we're thinking +about now unlike the previous example + + align:start position:0% +about now unlike the previous example + + + align:start position:0% +about now unlike the previous example +but the work we're doing in this + + align:start position:0% +but the work we're doing in this + + + align:start position:0% +but the work we're doing in this +relation now is non-trivial work + + align:start position:0% +relation now is non-trivial work + + + align:start position:0% +relation now is non-trivial work +before we were just guessing among two + + align:start position:0% +before we were just guessing among two + + + align:start position:0% +before we were just guessing among two +different choices now we're guessing + + align:start position:0% +different choices now we're guessing + + + align:start position:0% +different choices now we're guessing +among + + align:start position:0% +among + + + align:start position:0% +among +up to n different choices this n here is + + align:start position:0% +up to n different choices this n here is + + + align:start position:0% +up to n different choices this n here is +length of a + + align:start position:0% + + + + align:start position:0% + +and so we have theta + + align:start position:0% +and so we have theta + + + align:start position:0% +and so we have theta +length of a + + align:start position:0% + + + + align:start position:0% + +non-recursive work + + align:start position:0% + + + + align:start position:0% + +that we're doing in each subproblem + + align:start position:0% + + + + align:start position:0% + +or you might think of this as choices + + align:start position:0% +or you might think of this as choices + + + align:start position:0% +or you might think of this as choices +that we're considering + + align:start position:0% + + + + align:start position:0% + +and for each choice we're just spending + + align:start position:0% +and for each choice we're just spending + + + align:start position:0% +and for each choice we're just spending +i mean we're just taking a max of those + + align:start position:0% +i mean we're just taking a max of those + + + align:start position:0% +i mean we're just taking a max of those +items adding one + + align:start position:0% +items adding one + + + align:start position:0% +items adding one +so that's a constant overhead and so we + + align:start position:0% +so that's a constant overhead and so we + + + align:start position:0% +so that's a constant overhead and so we +just get this product + + align:start position:0% +just get this product + + + align:start position:0% +just get this product +which is a squared + + align:start position:0% + + + + align:start position:0% + +cool so that's the longest increasing + + align:start position:0% +cool so that's the longest increasing + + + align:start position:0% +cool so that's the longest increasing +subsequence make sure i didn't miss + + align:start position:0% +subsequence make sure i didn't miss + + + align:start position:0% +subsequence make sure i didn't miss +anything else + + align:start position:0% +anything else + + + align:start position:0% +anything else +so we're using this idea of asking a + + align:start position:0% +so we're using this idea of asking a + + + align:start position:0% +so we're using this idea of asking a +question + + align:start position:0% +question + + + align:start position:0% +question +and guessing or brute forcing the answer + + align:start position:0% +and guessing or brute forcing the answer + + + align:start position:0% +and guessing or brute forcing the answer +to that question + + align:start position:0% +to that question + + + align:start position:0% +to that question +in two places one place is + + align:start position:0% +in two places one place is + + + align:start position:0% +in two places one place is +we're promising we're being we're + + align:start position:0% +we're promising we're being we're + + + align:start position:0% +we're promising we're being we're +requesting that the longest increasing + + align:start position:0% +requesting that the longest increasing + + + align:start position:0% +requesting that the longest increasing +sub sequence starts at i + + align:start position:0% +sub sequence starts at i + + + align:start position:0% +sub sequence starts at i +so then the question is well what is the + + align:start position:0% +so then the question is well what is the + + + align:start position:0% +so then the question is well what is the +very second + + align:start position:0% +very second + + + align:start position:0% +very second +uh item that's in the longest increasing + + align:start position:0% +uh item that's in the longest increasing + + + align:start position:0% +uh item that's in the longest increasing +subsequence that it starts with i + + align:start position:0% +subsequence that it starts with i + + + align:start position:0% +subsequence that it starts with i +uh we're calling that j and we're brute + + align:start position:0% +uh we're calling that j and we're brute + + + align:start position:0% +uh we're calling that j and we're brute +forcing all the possible choices that j + + align:start position:0% +forcing all the possible choices that j + + + align:start position:0% +forcing all the possible choices that j +could be which conveniently lets us + + align:start position:0% +could be which conveniently lets us + + + align:start position:0% +could be which conveniently lets us +check confirm that it's actually an + + align:start position:0% +check confirm that it's actually an + + + align:start position:0% +check confirm that it's actually an +increasing subsequence locally from i to + + align:start position:0% +increasing subsequence locally from i to + + + align:start position:0% +increasing subsequence locally from i to +j + + align:start position:0% +j + + + align:start position:0% +j +and then l of j will take care of the + + align:start position:0% +and then l of j will take care of the + + + align:start position:0% +and then l of j will take care of the +rest by induction + + align:start position:0% +rest by induction + + + align:start position:0% +rest by induction +the rest of the longest increasing + + align:start position:0% +the rest of the longest increasing + + + align:start position:0% +the rest of the longest increasing +subsequence starting at j will also be + + align:start position:0% +subsequence starting at j will also be + + + align:start position:0% +subsequence starting at j will also be +increasing and so this guarantees by + + align:start position:0% +increasing and so this guarantees by + + + align:start position:0% +increasing and so this guarantees by +induction + + align:start position:0% +induction + + + align:start position:0% +induction +the whole thing will be increasing then + + align:start position:0% +the whole thing will be increasing then + + + align:start position:0% +the whole thing will be increasing then +we also use this + + align:start position:0% +we also use this + + + align:start position:0% +we also use this +uh local brute force to solve the + + align:start position:0% +uh local brute force to solve the + + + align:start position:0% +uh local brute force to solve the +original problem + + align:start position:0% +original problem + + + align:start position:0% +original problem +so we added this constraint of starting + + align:start position:0% +so we added this constraint of starting + + + align:start position:0% +so we added this constraint of starting +at i but we didn't actually know overall + + align:start position:0% +at i but we didn't actually know overall + + + align:start position:0% +at i but we didn't actually know overall +where to start + + align:start position:0% +where to start + + + align:start position:0% +where to start +but that's fine because there's only + + align:start position:0% +but that's fine because there's only + + + align:start position:0% +but that's fine because there's only +eight choices so i should mention + + align:start position:0% +eight choices so i should mention + + + align:start position:0% +eight choices so i should mention +in the running time analysis so they're + + align:start position:0% +in the running time analysis so they're + + + align:start position:0% +in the running time analysis so they're +solving the sub problems + + align:start position:0% +solving the sub problems + + + align:start position:0% +solving the sub problems +that's fine but then there's also a plus + + align:start position:0% +that's fine but then there's also a plus + + + align:start position:0% +that's fine but then there's also a plus +whatever it costs to solve the original + + align:start position:0% +whatever it costs to solve the original + + + align:start position:0% +whatever it costs to solve the original +problem + + align:start position:0% +problem + + + align:start position:0% +problem +but that's okay that's length of a + + align:start position:0% +but that's okay that's length of a + + + align:start position:0% +but that's okay that's length of a +so this was all of this plus length of a + + align:start position:0% +so this was all of this plus length of a + + + align:start position:0% +so this was all of this plus length of a +is still length of a squared + + align:start position:0% + + + + align:start position:0% + +okay but if you're doing you know + + align:start position:0% +okay but if you're doing you know + + + align:start position:0% +okay but if you're doing you know +exponential work here that would be bad + + align:start position:0% +exponential work here that would be bad + + + align:start position:0% +exponential work here that would be bad +we have to do some + + align:start position:0% +we have to do some + + + align:start position:0% +we have to do some +reasonable amount of work to solve the + + align:start position:0% +reasonable amount of work to solve the + + + align:start position:0% +reasonable amount of work to solve the +original problem in terms of all the sub + + align:start position:0% +original problem in terms of all the sub + + + align:start position:0% +original problem in terms of all the sub +problems + + align:start position:0% +problems + + + align:start position:0% +problems +i have an example hiding here + + align:start position:0% + + + + align:start position:0% + +this is a little harder to stare at here + + align:start position:0% +this is a little harder to stare at here + + + align:start position:0% +this is a little harder to stare at here +i have + + align:start position:0% +i have + + + align:start position:0% +i have +empathy and this example is not + + align:start position:0% +empathy and this example is not + + + align:start position:0% +empathy and this example is not +doesn't have much empathy because the + + align:start position:0% +doesn't have much empathy because the + + + align:start position:0% +doesn't have much empathy because the +longest increasing subsequence of + + align:start position:0% +longest increasing subsequence of + + + align:start position:0% +longest increasing subsequence of +empathy is + + align:start position:0% +empathy is + + + align:start position:0% +empathy is +empty + + align:start position:0% + + + + align:start position:0% + +empty is one of the few english words + + align:start position:0% +empty is one of the few english words + + + align:start position:0% +empty is one of the few english words +that's increasing + + align:start position:0% +that's increasing + + + align:start position:0% +that's increasing +and you the hard part here is drawing + + align:start position:0% +and you the hard part here is drawing + + + align:start position:0% +and you the hard part here is drawing +the dag + + align:start position:0% +the dag + + + align:start position:0% +the dag +i mean it's almost the complete graph + + align:start position:0% +i mean it's almost the complete graph + + + align:start position:0% +i mean it's almost the complete graph +but we only draw edges + + align:start position:0% +but we only draw edges + + + align:start position:0% +but we only draw edges +from smaller letters to bigger letters + + align:start position:0% +from smaller letters to bigger letters + + + align:start position:0% +from smaller letters to bigger letters +so we draw from e to m + + align:start position:0% +so we draw from e to m + + + align:start position:0% +so we draw from e to m +from e to p from e not to a there's no + + align:start position:0% +from e to p from e not to a there's no + + + align:start position:0% +from e to p from e not to a there's no +edge from e to a + + align:start position:0% +edge from e to a + + + align:start position:0% +edge from e to a +from e to t not from e to h + + align:start position:0% +from e to t not from e to h + + + align:start position:0% +from e to t not from e to h +but yes from e to y and then we also + + align:start position:0% +but yes from e to y and then we also + + + align:start position:0% +but yes from e to y and then we also +draw from e to the base case which is + + align:start position:0% +draw from e to the base case which is + + + align:start position:0% +draw from e to the base case which is +there's no more letters + + align:start position:0% +there's no more letters + + + align:start position:0% +there's no more letters +that was that that uh edge to the base + + align:start position:0% +that was that that uh edge to the base + + + align:start position:0% +that was that that uh edge to the base +case + + align:start position:0% +case + + + align:start position:0% +case +is + + align:start position:0% + + + + align:start position:0% + +uh corresponds to the zero + + align:start position:0% +uh corresponds to the zero + + + align:start position:0% +uh corresponds to the zero +or i guess this n where we say ah let's + + align:start position:0% +or i guess this n where we say ah let's + + + align:start position:0% +or i guess this n where we say ah let's +just + + align:start position:0% +just + + + align:start position:0% +just +recurse let's just throw away + + align:start position:0% + + + + align:start position:0% + +actually maybe we don't need the union + + align:start position:0% +actually maybe we don't need the union + + + align:start position:0% +actually maybe we don't need the union +zero there in fact because + + align:start position:0% +zero there in fact because + + + align:start position:0% +zero there in fact because +we include l of n which is the empty + + align:start position:0% +we include l of n which is the empty + + + align:start position:0% +we include l of n which is the empty +substring then the definition of + + align:start position:0% +substring then the definition of + + + align:start position:0% +substring then the definition of +of l is a little funny what does it mean + + align:start position:0% +of l is a little funny what does it mean + + + align:start position:0% +of l is a little funny what does it mean +to say you start with a of n + + align:start position:0% +to say you start with a of n + + + align:start position:0% +to say you start with a of n +hm right a of n is not defined so that's + + align:start position:0% +hm right a of n is not defined so that's + + + align:start position:0% +hm right a of n is not defined so that's +not so nice + + align:start position:0% +not so nice + + + align:start position:0% +not so nice +so maybe i'll fix that + + align:start position:0% + + + + align:start position:0% + +and decrease equals case + + align:start position:0% +and decrease equals case + + + align:start position:0% +and decrease equals case +okay but i'm still going to draw an edge + + align:start position:0% +okay but i'm still going to draw an edge + + + align:start position:0% +okay but i'm still going to draw an edge +there conceptually say oh we're just + + align:start position:0% +there conceptually say oh we're just + + + align:start position:0% +there conceptually say oh we're just +done at that point + + align:start position:0% +done at that point + + + align:start position:0% +done at that point +that's the base case where we have no + + align:start position:0% +that's the base case where we have no + + + align:start position:0% +that's the base case where we have no +string left + + align:start position:0% +string left + + + align:start position:0% +string left +um cool and when i said from to two + + align:start position:0% +um cool and when i said from to two + + + align:start position:0% +um cool and when i said from to two +actually i meant the reverse all the + + align:start position:0% +actually i meant the reverse all the + + + align:start position:0% +actually i meant the reverse all the +edges go from right to left + + align:start position:0% +edges go from right to left + + + align:start position:0% +edges go from right to left +um and then what we're doing is looking + + align:start position:0% +um and then what we're doing is looking + + + align:start position:0% +um and then what we're doing is looking +for the longest path in this dag + + align:start position:0% +for the longest path in this dag + + + align:start position:0% +for the longest path in this dag +um longest path is maybe a problem we've + + align:start position:0% +um longest path is maybe a problem we've + + + align:start position:0% +um longest path is maybe a problem we've +talked about in + + align:start position:0% +talked about in + + + align:start position:0% +talked about in +problem session because it's a dag + + align:start position:0% +problem session because it's a dag + + + align:start position:0% +problem session because it's a dag +well longest path is the same thing as + + align:start position:0% +well longest path is the same thing as + + + align:start position:0% +well longest path is the same thing as +shortest path if you just negate all the + + align:start position:0% +shortest path if you just negate all the + + + align:start position:0% +shortest path if you just negate all the +weights + + align:start position:0% +weights + + + align:start position:0% +weights +there are no weights in this picture so + + align:start position:0% +there are no weights in this picture so + + + align:start position:0% +there are no weights in this picture so +if you just put negative one + + align:start position:0% +if you just put negative one + + + align:start position:0% +if you just put negative one +on all these edges and ask for the + + align:start position:0% +on all these edges and ask for the + + + align:start position:0% +on all these edges and ask for the +shortest path + + align:start position:0% +shortest path + + + align:start position:0% +shortest path +from the base + + align:start position:0% +from the base + + + align:start position:0% +from the base +to anywhere so single source shortest + + align:start position:0% +to anywhere so single source shortest + + + align:start position:0% +to anywhere so single source shortest +paths from this base + + align:start position:0% +paths from this base + + + align:start position:0% +paths from this base +then we would end up getting this path + + align:start position:0% +then we would end up getting this path + + + align:start position:0% +then we would end up getting this path +which if you look at it is e m p + + align:start position:0% +which if you look at it is e m p + + + align:start position:0% +which if you look at it is e m p +t y empty and so that + + align:start position:0% +t y empty and so that + + + align:start position:0% +t y empty and so that +uh shortest path is indeed the right + + align:start position:0% +uh shortest path is indeed the right + + + align:start position:0% +uh shortest path is indeed the right +answer what i've drawn here is the + + align:start position:0% +answer what i've drawn here is the + + + align:start position:0% +answer what i've drawn here is the +shortest path tree + + align:start position:0% +shortest path tree + + + align:start position:0% +shortest path tree +so also if you wanted the longest + + align:start position:0% +so also if you wanted the longest + + + align:start position:0% +so also if you wanted the longest +increasing subsequence starting at + + align:start position:0% +increasing subsequence starting at + + + align:start position:0% +increasing subsequence starting at +a then it is a t y just by following + + align:start position:0% +a then it is a t y just by following + + + align:start position:0% +a then it is a t y just by following +the red arrows here and how do you get + + align:start position:0% +the red arrows here and how do you get + + + align:start position:0% +the red arrows here and how do you get +that you just + + align:start position:0% +that you just + + + align:start position:0% +that you just +draw the parent pointers just like we + + align:start position:0% +draw the parent pointers just like we + + + align:start position:0% +draw the parent pointers just like we +did before i didn't mention + + align:start position:0% +did before i didn't mention + + + align:start position:0% +did before i didn't mention +this example can also be solved with + + align:start position:0% +this example can also be solved with + + + align:start position:0% +this example can also be solved with +shortest paths once i'd construct this + + align:start position:0% +shortest paths once i'd construct this + + + align:start position:0% +shortest paths once i'd construct this +graph you can do the shortest path from + + align:start position:0% +graph you can do the shortest path from + + + align:start position:0% +graph you can do the shortest path from +some base i don't know which one + + align:start position:0% +some base i don't know which one + + + align:start position:0% +some base i don't know which one +to here if you put + + align:start position:0% +to here if you put + + + align:start position:0% +to here if you put +negative one on all of the diagonal + + align:start position:0% +negative one on all of the diagonal + + + align:start position:0% +negative one on all of the diagonal +edges + + align:start position:0% +edges + + + align:start position:0% +edges +and you put weight zero everywhere else + + align:start position:0% +and you put weight zero everywhere else + + + align:start position:0% +and you put weight zero everywhere else +then that corresponds to + + align:start position:0% +then that corresponds to + + + align:start position:0% +then that corresponds to +the shortest path in that graph will + + align:start position:0% +the shortest path in that graph will + + + align:start position:0% +the shortest path in that graph will +correspond to the longest + + align:start position:0% +correspond to the longest + + + align:start position:0% +correspond to the longest +the path with the most diagonal edges + + align:start position:0% +the path with the most diagonal edges + + + align:start position:0% +the path with the most diagonal edges +and that makes sense because the + + align:start position:0% +and that makes sense because the + + + align:start position:0% +and that makes sense because the +diagonal edges are where we actually get + + align:start position:0% +diagonal edges are where we actually get + + + align:start position:0% +diagonal edges are where we actually get +letters in common and so in this case + + align:start position:0% +letters in common and so in this case + + + align:start position:0% +letters in common and so in this case +it's + + align:start position:0% +it's + + + align:start position:0% +it's +two so both of these dynamic programs + + align:start position:0% +two so both of these dynamic programs + + + align:start position:0% +two so both of these dynamic programs +could instead + + align:start position:0% +could instead + + + align:start position:0% +could instead +instead of writing them as a recursive + + align:start position:0% +instead of writing them as a recursive + + + align:start position:0% +instead of writing them as a recursive +thing with memorization + + align:start position:0% +thing with memorization + + + align:start position:0% +thing with memorization +or writing them bottom up as a for loop + + align:start position:0% +or writing them bottom up as a for loop + + + align:start position:0% +or writing them bottom up as a for loop +and then + + align:start position:0% +and then + + + align:start position:0% +and then +doing the computation you could instead + + align:start position:0% +doing the computation you could instead + + + align:start position:0% +doing the computation you could instead +construct a graph + + align:start position:0% +construct a graph + + + align:start position:0% +construct a graph +and then run dag shortest paths on it + + align:start position:0% +and then run dag shortest paths on it + + + align:start position:0% +and then run dag shortest paths on it +but the point is these are the same + + align:start position:0% +but the point is these are the same + + + align:start position:0% +but the point is these are the same +thing it's actually a lot simpler to + + align:start position:0% +thing it's actually a lot simpler to + + + align:start position:0% +thing it's actually a lot simpler to +write the dynamic programming code + + align:start position:0% +write the dynamic programming code + + + align:start position:0% +write the dynamic programming code +because it's just a for loop and then a + + align:start position:0% +because it's just a for loop and then a + + + align:start position:0% +because it's just a for loop and then a +recurrence which you're just updating an + + align:start position:0% +recurrence which you're just updating an + + + align:start position:0% +recurrence which you're just updating an +array + + align:start position:0% +array + + + align:start position:0% +array +you don't because you already know what + + align:start position:0% +you don't because you already know what + + + align:start position:0% +you don't because you already know what +the + + align:start position:0% +the + + + align:start position:0% +the +topological order is you don't have to + + align:start position:0% +topological order is you don't have to + + + align:start position:0% +topological order is you don't have to +write a generic + + align:start position:0% +write a generic + + + align:start position:0% +write a generic +depth first search algorithm take the + + align:start position:0% +depth first search algorithm take the + + + align:start position:0% +depth first search algorithm take the +finishing order reverse it + + align:start position:0% +finishing order reverse it + + + align:start position:0% +finishing order reverse it +and then run this + + align:start position:0% +and then run this + + + align:start position:0% +and then run this +run dag shortest paths with relaxation + + align:start position:0% +run dag shortest paths with relaxation + + + align:start position:0% +run dag shortest paths with relaxation +uh much simpler to just write down the + + align:start position:0% +uh much simpler to just write down the + + + align:start position:0% +uh much simpler to just write down the +recurrence once you've figured it out + + align:start position:0% +recurrence once you've figured it out + + + align:start position:0% +recurrence once you've figured it out +okay but they are the same in these + + align:start position:0% +okay but they are the same in these + + + align:start position:0% +okay but they are the same in these +examples uh in fibonacci for example you + + align:start position:0% +examples uh in fibonacci for example you + + + align:start position:0% +examples uh in fibonacci for example you +cannot write fibonacci as a single + + align:start position:0% +cannot write fibonacci as a single + + + align:start position:0% +cannot write fibonacci as a single +source shortest path problem but a lot + + align:start position:0% +source shortest path problem but a lot + + + align:start position:0% +source shortest path problem but a lot +of dps + + align:start position:0% +of dps + + + align:start position:0% +of dps +you can write as the shortest paths + + align:start position:0% +you can write as the shortest paths + + + align:start position:0% +you can write as the shortest paths +problem + + align:start position:0% +problem + + + align:start position:0% +problem +just a connection to things we've seen + + align:start position:0% +just a connection to things we've seen + + + align:start position:0% +just a connection to things we've seen +all right last example + + align:start position:0% + + + + align:start position:0% + +last problem for today we'll do more + + align:start position:0% +last problem for today we'll do more + + + align:start position:0% +last problem for today we'll do more +next + + align:start position:0% + + + + align:start position:0% + +week + + align:start position:0% + + + + align:start position:0% + +alternating coin game this is a two + + align:start position:0% +alternating coin game this is a two + + + align:start position:0% +alternating coin game this is a two +player game + + align:start position:0% +player game + + + align:start position:0% +player game +we're gonna find the optimal strategy in + + align:start position:0% +we're gonna find the optimal strategy in + + + align:start position:0% +we're gonna find the optimal strategy in +this game uh + + align:start position:0% +this game uh + + + align:start position:0% +this game uh +so an example is in general you have a + + align:start position:0% +so an example is in general you have a + + + align:start position:0% +so an example is in general you have a +sequence of coins + + align:start position:0% + + + + align:start position:0% + +and we have two players + + align:start position:0% +and we have two players + + + align:start position:0% +and we have two players +they take turns so given + + align:start position:0% + + + + align:start position:0% + +coins of + + align:start position:0% +coins of + + + align:start position:0% +coins of +value uh v zero + + align:start position:0% +value uh v zero + + + align:start position:0% +value uh v zero +to v n minus one so it's a it's a + + align:start position:0% +to v n minus one so it's a it's a + + + align:start position:0% +to v n minus one so it's a it's a +sequence + + align:start position:0% + + + + align:start position:0% + +they're given an order in some order + + align:start position:0% + + + + align:start position:0% + +for example 5 10 125 not necessarily + + align:start position:0% +for example 5 10 125 not necessarily + + + align:start position:0% +for example 5 10 125 not necessarily +sorted order + + align:start position:0% +sorted order + + + align:start position:0% +sorted order +and the rules of the game are we're + + align:start position:0% +and the rules of the game are we're + + + align:start position:0% +and the rules of the game are we're +going to take turns i'm going to take + + align:start position:0% +going to take turns i'm going to take + + + align:start position:0% +going to take turns i'm going to take +turns with you + + align:start position:0% +turns with you + + + align:start position:0% +turns with you +i'm going to use i and u to refer to the + + align:start position:0% +i'm going to use i and u to refer to the + + + align:start position:0% +i'm going to use i and u to refer to the +two players + + align:start position:0% +two players + + + align:start position:0% +two players +and so in each turn either one whoever's + + align:start position:0% +and so in each turn either one whoever's + + + align:start position:0% +and so in each turn either one whoever's +turn it is + + align:start position:0% +turn it is + + + align:start position:0% +turn it is +i get to we get to choose either the + + align:start position:0% +i get to we get to choose either the + + + align:start position:0% +i get to we get to choose either the +first coin + + align:start position:0% +first coin + + + align:start position:0% +first coin +or the last coin among the coins that + + align:start position:0% +or the last coin among the coins that + + + align:start position:0% +or the last coin among the coins that +remain so at the beginning i can choose + + align:start position:0% +remain so at the beginning i can choose + + + align:start position:0% +remain so at the beginning i can choose +5 or 25 and i might think + + align:start position:0% +5 or 25 and i might think + + + align:start position:0% +5 or 25 and i might think +oh 25 is really good that's better than + + align:start position:0% +oh 25 is really good that's better than + + + align:start position:0% +oh 25 is really good that's better than +5. i should choose that + + align:start position:0% +5. i should choose that + + + align:start position:0% +5. i should choose that +but then of course you're you're going + + align:start position:0% +but then of course you're you're going + + + align:start position:0% +but then of course you're you're going +next and you're going to choose 100 + + align:start position:0% +next and you're going to choose 100 + + + align:start position:0% +next and you're going to choose 100 +and you'll win the game you'll get more + + align:start position:0% +and you'll win the game you'll get more + + + align:start position:0% +and you'll win the game you'll get more +of the total value of the coins + + align:start position:0% +of the total value of the coins + + + align:start position:0% +of the total value of the coins +so in this example a better strategy is + + align:start position:0% +so in this example a better strategy is + + + align:start position:0% +so in this example a better strategy is +to take the five + + align:start position:0% +to take the five + + + align:start position:0% +to take the five +because then the hundred is still in the + + align:start position:0% +because then the hundred is still in the + + + align:start position:0% +because then the hundred is still in the +middle and so once once i take + + align:start position:0% +middle and so once once i take + + + align:start position:0% +middle and so once once i take +five uh you get to choose + + align:start position:0% +five uh you get to choose + + + align:start position:0% +five uh you get to choose +10 or 25 at this point you probably + + align:start position:0% +10 or 25 at this point you probably + + + align:start position:0% +10 or 25 at this point you probably +prefer 25 because that's better than 10 + + align:start position:0% +prefer 25 because that's better than 10 + + + align:start position:0% +prefer 25 because that's better than 10 +but whichever you choose i can take the + + align:start position:0% +but whichever you choose i can take the + + + align:start position:0% +but whichever you choose i can take the +100 and so i get 105 points + + align:start position:0% +100 and so i get 105 points + + + align:start position:0% +100 and so i get 105 points +and you're going to get 35 points + + align:start position:0% +and you're going to get 35 points + + + align:start position:0% +and you're going to get 35 points +okay good good example for me um + + align:start position:0% +okay good good example for me um + + + align:start position:0% +okay good good example for me um +and what we're going to do so that's + + align:start position:0% +and what we're going to do so that's + + + align:start position:0% +and what we're going to do so that's +easy for a simple example but + + align:start position:0% +easy for a simple example but + + + align:start position:0% +easy for a simple example but +in general there are exponentially many + + align:start position:0% +in general there are exponentially many + + + align:start position:0% +in general there are exponentially many +strategies here at each step either of + + align:start position:0% +strategies here at each step either of + + + align:start position:0% +strategies here at each step either of +us could go left or right + + align:start position:0% +us could go left or right + + + align:start position:0% +us could go left or right +choose the leftmost or the rightmost and + + align:start position:0% +choose the leftmost or the rightmost and + + + align:start position:0% +choose the leftmost or the rightmost and +we're going to give a dynamic + + align:start position:0% +we're going to give a dynamic + + + align:start position:0% +we're going to give a dynamic +programming + + align:start position:0% +programming + + + align:start position:0% +programming +algorithm that just solves this fast uh + + align:start position:0% +algorithm that just solves this fast uh + + + align:start position:0% +algorithm that just solves this fast uh +i didn't mention so this algorithm is + + align:start position:0% +i didn't mention so this algorithm is + + + align:start position:0% +i didn't mention so this algorithm is +quadratic time but it can be made n log + + align:start position:0% +quadratic time but it can be made n log + + + align:start position:0% +quadratic time but it can be made n log +n time it's a fun + + align:start position:0% +n time it's a fun + + + align:start position:0% +n time it's a fun +exercise using a lot of the data + + align:start position:0% +exercise using a lot of the data + + + align:start position:0% +exercise using a lot of the data +structure augmentation stuff + + align:start position:0% +structure augmentation stuff + + + align:start position:0% +structure augmentation stuff +we've done you can make this n log n + + align:start position:0% +we've done you can make this n log n + + + align:start position:0% +we've done you can make this n log n +this algorithm i think is going to be n + + align:start position:0% +this algorithm i think is going to be n + + + align:start position:0% +this algorithm i think is going to be n +squared time uh y + + align:start position:0% + + + + align:start position:0% + +so i won't write the problem + + align:start position:0% +so i won't write the problem + + + align:start position:0% +so i won't write the problem +exactly but i think you know the rules + + align:start position:0% +exactly but i think you know the rules + + + align:start position:0% +exactly but i think you know the rules +she's left most of rightmost coin + + align:start position:0% +she's left most of rightmost coin + + + align:start position:0% +she's left most of rightmost coin +alternating moves + + align:start position:0% +alternating moves + + + align:start position:0% +alternating moves +so i'd like to define some + + align:start position:0% +so i'd like to define some + + + align:start position:0% +so i'd like to define some +sub problems and this is a problem + + align:start position:0% +sub problems and this is a problem + + + align:start position:0% +sub problems and this is a problem +that's very naturally a substring + + align:start position:0% +that's very naturally a substring + + + align:start position:0% +that's very naturally a substring +problem + + align:start position:0% +problem + + + align:start position:0% +problem +right if i just looked at suffixes that + + align:start position:0% +right if i just looked at suffixes that + + + align:start position:0% +right if i just looked at suffixes that +would deal great with if i'm + + align:start position:0% +would deal great with if i'm + + + align:start position:0% +would deal great with if i'm +deleting coins from the left but as soon + + align:start position:0% +deleting coins from the left but as soon + + + align:start position:0% +deleting coins from the left but as soon +as i delete a and if i + + align:start position:0% +as i delete a and if i + + + align:start position:0% +as i delete a and if i +delete coins only from the right that + + align:start position:0% +delete coins only from the right that + + + align:start position:0% +delete coins only from the right that +would give me prefixes + + align:start position:0% +would give me prefixes + + + align:start position:0% +would give me prefixes +but i'll tell you now there's no dynamic + + align:start position:0% +but i'll tell you now there's no dynamic + + + align:start position:0% +but i'll tell you now there's no dynamic +programming where the answer is + + align:start position:0% +programming where the answer is + + + align:start position:0% +programming where the answer is +suffixes and prefixes you can do + + align:start position:0% +suffixes and prefixes you can do + + + align:start position:0% +suffixes and prefixes you can do +suffixes or prefixes but if you need + + align:start position:0% +suffixes or prefixes but if you need + + + align:start position:0% +suffixes or prefixes but if you need +both + + align:start position:0% +both + + + align:start position:0% +both +you almost certainly need substrings + + align:start position:0% +you almost certainly need substrings + + + align:start position:0% +you almost certainly need substrings +because as soon as i delete + + align:start position:0% +because as soon as i delete + + + align:start position:0% +because as soon as i delete +the first coin and then maybe you take + + align:start position:0% +the first coin and then maybe you take + + + align:start position:0% +the first coin and then maybe you take +the second coin + + align:start position:0% +the second coin + + + align:start position:0% +the second coin +that's exactly the optimal strategy here + + align:start position:0% +that's exactly the optimal strategy here + + + align:start position:0% +that's exactly the optimal strategy here +now you have an arbitrary substring in + + align:start position:0% +now you have an arbitrary substring in + + + align:start position:0% +now you have an arbitrary substring in +the middle + + align:start position:0% +the middle + + + align:start position:0% +the middle +okay but substrings are enough because + + align:start position:0% +okay but substrings are enough because + + + align:start position:0% +okay but substrings are enough because +we're only deleting from the ends + + align:start position:0% +we're only deleting from the ends + + + align:start position:0% +we're only deleting from the ends +we'll look at substrings + + align:start position:0% + + + + align:start position:0% + +so more precisely this is just the + + align:start position:0% +so more precisely this is just the + + + align:start position:0% +so more precisely this is just the +intuition + + align:start position:0% +intuition + + + align:start position:0% +intuition +we're going to define some generic x + + align:start position:0% +we're going to define some generic x + + + align:start position:0% +we're going to define some generic x +of i j is going to be what + + align:start position:0% +of i j is going to be what + + + align:start position:0% +of i j is going to be what +is the maximum + + align:start position:0% + + + + align:start position:0% + +total value + + align:start position:0% + + + + align:start position:0% + +i can get + + align:start position:0% + + + + align:start position:0% + +uh from this game uh if we play it on + + align:start position:0% +uh from this game uh if we play it on + + + align:start position:0% +uh from this game uh if we play it on +coins uh of value + + align:start position:0% +coins uh of value + + + align:start position:0% +coins uh of value +vi + + align:start position:0% + + + + align:start position:0% + +to vj so that's a substring + + align:start position:0% +to vj so that's a substring + + + align:start position:0% +to vj so that's a substring +so this is one way to write down the sub + + align:start position:0% +so this is one way to write down the sub + + + align:start position:0% +so this is one way to write down the sub +problems and is also + + align:start position:0% +problems and is also + + + align:start position:0% +problems and is also +a good way i mean you can write down a + + align:start position:0% +a good way i mean you can write down a + + + align:start position:0% +a good way i mean you can write down a +relation + + align:start position:0% +relation + + + align:start position:0% +relation +on this + + align:start position:0% + + + + align:start position:0% + +on this definition of sub problems but + + align:start position:0% +on this definition of sub problems but + + + align:start position:0% +on this definition of sub problems but +i'm i'm low on time there's there's two + + align:start position:0% +i'm i'm low on time there's there's two + + + align:start position:0% +i'm i'm low on time there's there's two +ways to solve this problem + + align:start position:0% +ways to solve this problem + + + align:start position:0% +ways to solve this problem +this is a reasonable way exploiting that + + align:start position:0% +this is a reasonable way exploiting that + + + align:start position:0% +this is a reasonable way exploiting that +the game is zero sum + + align:start position:0% +the game is zero sum + + + align:start position:0% +the game is zero sum +but i'd like to uh change this a little + + align:start position:0% +but i'd like to uh change this a little + + + align:start position:0% +but i'd like to uh change this a little +bit + + align:start position:0% +bit + + + align:start position:0% +bit +to give you a i think what's a cleaner + + align:start position:0% +to give you a i think what's a cleaner + + + align:start position:0% +to give you a i think what's a cleaner +way to solve the problem + + align:start position:0% +way to solve the problem + + + align:start position:0% +way to solve the problem +which is to add a third coordinate + + align:start position:0% +which is to add a third coordinate + + + align:start position:0% +which is to add a third coordinate +to my sub-problems so now it's + + align:start position:0% +to my sub-problems so now it's + + + align:start position:0% +to my sub-problems so now it's +parameterized by three things + + align:start position:0% +parameterized by three things + + + align:start position:0% +parameterized by three things +p here is uh + + align:start position:0% +p here is uh + + + align:start position:0% +p here is uh +only has two choices it's me or you + + align:start position:0% +only has two choices it's me or you + + + align:start position:0% +only has two choices it's me or you +okay and this gets at a point that's + + align:start position:0% +okay and this gets at a point that's + + + align:start position:0% +okay and this gets at a point that's +maybe not totally clear from this + + align:start position:0% +maybe not totally clear from this + + + align:start position:0% +maybe not totally clear from this +definition + + align:start position:0% +definition + + + align:start position:0% +definition +uh max total value that i can get uh + + align:start position:0% +uh max total value that i can get uh + + + align:start position:0% +uh max total value that i can get uh +from these + + align:start position:0% +from these + + + align:start position:0% +from these +this substring of coins but uh this is + + align:start position:0% +this substring of coins but uh this is + + + align:start position:0% +this substring of coins but uh this is +not obviously what i need so obviously + + align:start position:0% +not obviously what i need so obviously + + + align:start position:0% +not obviously what i need so obviously +at the beginning i want the whole string + + align:start position:0% +at the beginning i want the whole string + + + align:start position:0% +at the beginning i want the whole string +and i want to know what my maximum value + + align:start position:0% +and i want to know what my maximum value + + + align:start position:0% +and i want to know what my maximum value +is fine + + align:start position:0% +is fine + + + align:start position:0% +is fine +and i go first in this game i didn't + + align:start position:0% +and i go first in this game i didn't + + + align:start position:0% +and i go first in this game i didn't +specify + + align:start position:0% +specify + + + align:start position:0% +specify +but i do overloading i + + align:start position:0% +but i do overloading i + + + align:start position:0% +but i do overloading i +but as soon as i do a move as soon as i + + align:start position:0% +but as soon as i do a move as soon as i + + + align:start position:0% +but as soon as i do a move as soon as i +take the first coin for example + + align:start position:0% +take the first coin for example + + + align:start position:0% +take the first coin for example +it's now your turn and so i don't really + + align:start position:0% +it's now your turn and so i don't really + + + align:start position:0% +it's now your turn and so i don't really +want to + + align:start position:0% +want to + + + align:start position:0% +want to +know the maximum total value that i + + align:start position:0% +know the maximum total value that i + + + align:start position:0% +know the maximum total value that i +would get if i go first + + align:start position:0% +would get if i go first + + + align:start position:0% +would get if i go first +i'd like to say uh + + align:start position:0% +i'd like to say uh + + + align:start position:0% +i'd like to say uh +if player p goes first i'd really like + + align:start position:0% +if player p goes first i'd really like + + + align:start position:0% +if player p goes first i'd really like +to know + + align:start position:0% +to know + + + align:start position:0% +to know +what what happens in the case where you + + align:start position:0% +what what happens in the case where you + + + align:start position:0% +what what happens in the case where you +go first + + align:start position:0% +go first + + + align:start position:0% +go first +and so for some of the uh substrings i + + align:start position:0% +and so for some of the uh substrings i + + + align:start position:0% +and so for some of the uh substrings i +want to know what happens when you go + + align:start position:0% +want to know what happens when you go + + + align:start position:0% +want to know what happens when you go +first and for + + align:start position:0% +first and for + + + align:start position:0% +first and for +some of them i want to know what happens + + align:start position:0% +some of them i want to know what happens + + + align:start position:0% +some of them i want to know what happens +when i go first because as soon as i + + align:start position:0% +when i go first because as soon as i + + + align:start position:0% +when i go first because as soon as i +make a move + + align:start position:0% +make a move + + + align:start position:0% +make a move +it's your turn and so we're going to + + align:start position:0% +it's your turn and so we're going to + + + align:start position:0% +it's your turn and so we're going to +flip back and forth between p + + align:start position:0% +flip back and forth between p + + + align:start position:0% +flip back and forth between p +being me and p being u p u + + align:start position:0% +being me and p being u p u + + + align:start position:0% +being me and p being u p u +so you don't have to parameterize this + + align:start position:0% +so you don't have to parameterize this + + + align:start position:0% +so you don't have to parameterize this +there's a way to write the recurrence + + align:start position:0% +there's a way to write the recurrence + + + align:start position:0% +there's a way to write the recurrence +otherwise but + + align:start position:0% +otherwise but + + + align:start position:0% +otherwise but +this is i think a lot more intuitive + + align:start position:0% +this is i think a lot more intuitive + + + align:start position:0% +this is i think a lot more intuitive +because now we can do + + align:start position:0% +because now we can do + + + align:start position:0% +because now we can do +a very simple relation + + align:start position:0% + + + + align:start position:0% + +which is as follows + + align:start position:0% +which is as follows + + + align:start position:0% +which is as follows +so i'm going to split into two cases one + + align:start position:0% +so i'm going to split into two cases one + + + align:start position:0% +so i'm going to split into two cases one +is x of i j + + align:start position:0% +is x of i j + + + align:start position:0% +is x of i j +me and the other is x of i j u + + align:start position:0% + + + + align:start position:0% + +uh so x of i j me so i have + + align:start position:0% +uh so x of i j me so i have + + + align:start position:0% +uh so x of i j me so i have +i have some substring from i to j + + align:start position:0% +i have some substring from i to j + + + align:start position:0% +i have some substring from i to j +uh what could i do i could take the + + align:start position:0% +uh what could i do i could take the + + + align:start position:0% +uh what could i do i could take the +first coin or i could take the second + + align:start position:0% +first coin or i could take the second + + + align:start position:0% +first coin or i could take the second +coin + + align:start position:0% +coin + + + align:start position:0% +coin +what should i do that's my question + + align:start position:0% +what should i do that's my question + + + align:start position:0% +what should i do that's my question +should what is my first move + + align:start position:0% +should what is my first move + + + align:start position:0% +should what is my first move +should i take the first coin or the + + align:start position:0% +should i take the first coin or the + + + align:start position:0% +should i take the first coin or the +second coin so this is my question + + align:start position:0% +second coin so this is my question + + + align:start position:0% +second coin so this is my question +what is the first move + + align:start position:0% + + + + align:start position:0% + +there are exactly two possible answers + + align:start position:0% +there are exactly two possible answers + + + align:start position:0% +there are exactly two possible answers +to that question so we can afford to + + align:start position:0% +to that question so we can afford to + + + align:start position:0% +to that question so we can afford to +just brute force them + + align:start position:0% +just brute force them + + + align:start position:0% +just brute force them +and take the max + + align:start position:0% +and take the max + + + align:start position:0% +and take the max +for moving we want the maximum + + align:start position:0% +for moving we want the maximum + + + align:start position:0% +for moving we want the maximum +number of points we can get maximum + + align:start position:0% +number of points we can get maximum + + + align:start position:0% +number of points we can get maximum +total value of + + align:start position:0% +total value of + + + align:start position:0% +total value of +the two choices so if if i take from the + + align:start position:0% +the two choices so if if i take from the + + + align:start position:0% +the two choices so if if i take from the +i side the left side + + align:start position:0% +i side the left side + + + align:start position:0% +i side the left side +that would be x of i plus one j + + align:start position:0% +that would be x of i plus one j + + + align:start position:0% +that would be x of i plus one j +uh sorry and now crucially we flip + + align:start position:0% +uh sorry and now crucially we flip + + + align:start position:0% +uh sorry and now crucially we flip +players because then it's your turn + + align:start position:0% +players because then it's your turn + + + align:start position:0% +players because then it's your turn +and if i take from the j side that will + + align:start position:0% +and if i take from the j side that will + + + align:start position:0% +and if i take from the j side that will +make it j minus one + + align:start position:0% +make it j minus one + + + align:start position:0% +make it j minus one +this is what i accidentally wrote at the + + align:start position:0% +this is what i accidentally wrote at the + + + align:start position:0% +this is what i accidentally wrote at the +beginning of lecture + + align:start position:0% + + + + align:start position:0% + +also flipped players so either i shrink + + align:start position:0% +also flipped players so either i shrink + + + align:start position:0% +also flipped players so either i shrink +on the i side or a shrink on the j side + + align:start position:0% +on the i side or a shrink on the j side + + + align:start position:0% +on the i side or a shrink on the j side +oh i should add on + + align:start position:0% +oh i should add on + + + align:start position:0% +oh i should add on +here the value of the coin that i get + + align:start position:0% +here the value of the coin that i get + + + align:start position:0% +here the value of the coin that i get +and add on the value of the coin that i + + align:start position:0% +and add on the value of the coin that i + + + align:start position:0% +and add on the value of the coin that i +took + + align:start position:0% +took + + + align:start position:0% +took +sorry these are this is a an expression + + align:start position:0% +sorry these are this is a an expression + + + align:start position:0% +sorry these are this is a an expression +inside the max + + align:start position:0% +inside the max + + + align:start position:0% +inside the max +that sum okay and if i take the max + + align:start position:0% +that sum okay and if i take the max + + + align:start position:0% +that sum okay and if i take the max +those two options that will give + + align:start position:0% +those two options that will give + + + align:start position:0% +those two options that will give +that is my locally brute forced best + + align:start position:0% +that is my locally brute forced best + + + align:start position:0% +that is my locally brute forced best +choice + + align:start position:0% +choice + + + align:start position:0% +choice +of how many how what are the total value + + align:start position:0% +of how many how what are the total value + + + align:start position:0% +of how many how what are the total value +of coins i will get out of the remainder + + align:start position:0% +of coins i will get out of the remainder + + + align:start position:0% +of coins i will get out of the remainder +given that you start plus this coin that + + align:start position:0% +given that you start plus this coin that + + + align:start position:0% +given that you start plus this coin that +i took right now in the first step + + align:start position:0% +i took right now in the first step + + + align:start position:0% +i took right now in the first step +and for the two possible choices of what + + align:start position:0% +and for the two possible choices of what + + + align:start position:0% +and for the two possible choices of what +that coin is + + align:start position:0% +that coin is + + + align:start position:0% +that coin is +okay what remains is how do we how do we + + align:start position:0% +okay what remains is how do we how do we + + + align:start position:0% +okay what remains is how do we how do we +define this x of i j + + align:start position:0% +define this x of i j + + + align:start position:0% +define this x of i j +u this is a little bit funnier + + align:start position:0% +u this is a little bit funnier + + + align:start position:0% +u this is a little bit funnier +but it's conceptually similar i'm going + + align:start position:0% +but it's conceptually similar i'm going + + + align:start position:0% +but it's conceptually similar i'm going +to write + + align:start position:0% +to write + + + align:start position:0% +to write +basically the same thing here but with a + + align:start position:0% +basically the same thing here but with a + + + align:start position:0% +basically the same thing here but with a +me + + align:start position:0% +me + + + align:start position:0% +me +instead of a u because again it flips + + align:start position:0% + + + + align:start position:0% + +this is if you go first then the very + + align:start position:0% +this is if you go first then the very + + + align:start position:0% +this is if you go first then the very +next move will be me + + align:start position:0% +next move will be me + + + align:start position:0% +next move will be me +okay so this is just the symmetric + + align:start position:0% + + + + align:start position:0% + +formula here i can even put the braces + + align:start position:0% +formula here i can even put the braces + + + align:start position:0% +formula here i can even put the braces +in + + align:start position:0% +in + + + align:start position:0% +in +so far the same now + + align:start position:0% +so far the same now + + + align:start position:0% +so far the same now +i don't put in the plus vi and i don't + + align:start position:0% +i don't put in the plus vi and i don't + + + align:start position:0% +i don't put in the plus vi and i don't +put in the plus vj here because if + + align:start position:0% +put in the plus vj here because if + + + align:start position:0% +put in the plus vj here because if +you're moving i don't get those points + + align:start position:0% +you're moving i don't get those points + + + align:start position:0% +you're moving i don't get those points +so there's an asymmetry in this + + align:start position:0% +so there's an asymmetry in this + + + align:start position:0% +so there's an asymmetry in this +definition you could define it in + + align:start position:0% +definition you could define it in + + + align:start position:0% +definition you could define it in +different ways but + + align:start position:0% +different ways but + + + align:start position:0% +different ways but +this is the maximum total value that i + + align:start position:0% +this is the maximum total value that i + + + align:start position:0% +this is the maximum total value that i +would get if you start + + align:start position:0% +would get if you start + + + align:start position:0% +would get if you start +so in your first move you get some + + align:start position:0% +so in your first move you get some + + + align:start position:0% +so in your first move you get some +points but i don't get any points out of + + align:start position:0% +points but i don't get any points out of + + + align:start position:0% +points but i don't get any points out of +that + + align:start position:0% +that + + + align:start position:0% +that +so there's no plus vi there's no plus vj + + align:start position:0% +so there's no plus vi there's no plus vj + + + align:start position:0% +so there's no plus vi there's no plus vj +it's just + + align:start position:0% +it's just + + + align:start position:0% +it's just +you either choose the ith coin or you + + align:start position:0% +you either choose the ith coin or you + + + align:start position:0% +you either choose the ith coin or you +choose the jth coin and then the coins + + align:start position:0% +choose the jth coin and then the coins + + + align:start position:0% +choose the jth coin and then the coins +that remain + + align:start position:0% +that remain + + + align:start position:0% +that remain +for me shrink accordingly now + + align:start position:0% +for me shrink accordingly now + + + align:start position:0% +for me shrink accordingly now +you're kind of a pain in the ass you're + + align:start position:0% +you're kind of a pain in the ass you're + + + align:start position:0% +you're kind of a pain in the ass you're +an adversary you're trying to minimize + + align:start position:0% +an adversary you're trying to minimize + + + align:start position:0% +an adversary you're trying to minimize +my score + + align:start position:0% +my score + + + align:start position:0% +my score +potentially because you're trying to + + align:start position:0% +potentially because you're trying to + + + align:start position:0% +potentially because you're trying to +maximize your score this is a zero-sum + + align:start position:0% +maximize your score this is a zero-sum + + + align:start position:0% +maximize your score this is a zero-sum +game so everything that you get i don't + + align:start position:0% +game so everything that you get i don't + + + align:start position:0% +game so everything that you get i don't +get + + align:start position:0% +get + + + align:start position:0% +get +so you want to maximize your score if + + align:start position:0% +so you want to maximize your score if + + + align:start position:0% +so you want to maximize your score if +you want to maximize your score you're + + align:start position:0% +you want to maximize your score you're + + + align:start position:0% +you want to maximize your score you're +trying to minimize my score these are + + align:start position:0% +trying to minimize my score these are + + + align:start position:0% +trying to minimize my score these are +symmetric things + + align:start position:0% +symmetric things + + + align:start position:0% +symmetric things +and so if you think for a while the + + align:start position:0% +and so if you think for a while the + + + align:start position:0% +and so if you think for a while the +right thing to put here is min + + align:start position:0% +right thing to put here is min + + + align:start position:0% +right thing to put here is min +from our perspective we're imagining + + align:start position:0% +from our perspective we're imagining + + + align:start position:0% +from our perspective we're imagining +what is the worst case that could happen + + align:start position:0% +what is the worst case that could happen + + + align:start position:0% +what is the worst case that could happen +no matter what you do and we don't have + + align:start position:0% +no matter what you do and we don't have + + + align:start position:0% +no matter what you do and we don't have +control over what you do + + align:start position:0% +control over what you do + + + align:start position:0% +control over what you do +and so we'd really like to see what + + align:start position:0% +and so we'd really like to see what + + + align:start position:0% +and so we'd really like to see what +score would i get if you chose the + + align:start position:0% +score would i get if you chose the + + + align:start position:0% +score would i get if you chose the +ithcoin what + + align:start position:0% +ithcoin what + + + align:start position:0% +ithcoin what +score do you get if if you chose the jth + + align:start position:0% +score do you get if if you chose the jth + + + align:start position:0% +score do you get if if you chose the jth +coin + + align:start position:0% +coin + + + align:start position:0% +coin +and then what we get is going to be the + + align:start position:0% +and then what we get is going to be the + + + align:start position:0% +and then what we get is going to be the +worst of those two possibilities + + align:start position:0% +worst of those two possibilities + + + align:start position:0% +worst of those two possibilities +so when we get to choose we're + + align:start position:0% +so when we get to choose we're + + + align:start position:0% +so when we get to choose we're +maximizing and this is a general + + align:start position:0% +maximizing and this is a general + + + align:start position:0% +maximizing and this is a general +two-player phenomenon + + align:start position:0% +two-player phenomenon + + + align:start position:0% +two-player phenomenon +that when you choose we end up + + align:start position:0% +that when you choose we end up + + + align:start position:0% +that when you choose we end up +minimizing because that's the saddest + + align:start position:0% +minimizing because that's the saddest + + + align:start position:0% +minimizing because that's the saddest +thing that happened to us + + align:start position:0% +thing that happened to us + + + align:start position:0% +thing that happened to us +okay this is one way to write a + + align:start position:0% +okay this is one way to write a + + + align:start position:0% +okay this is one way to write a +recurrence relation + + align:start position:0% +recurrence relation + + + align:start position:0% +recurrence relation +um we have of course + + align:start position:0% + + + + align:start position:0% + +all of sort bot to do so the topological + + align:start position:0% +all of sort bot to do so the topological + + + align:start position:0% +all of sort bot to do so the topological +order here is in + + align:start position:0% +order here is in + + + align:start position:0% +order here is in +increasing length of substrings so the t + + align:start position:0% +increasing length of substrings so the t + + + align:start position:0% +increasing length of substrings so the t +is increasing j minus i + + align:start position:0% +is increasing j minus i + + + align:start position:0% +is increasing j minus i +start with empty strings so base case is + + align:start position:0% +start with empty strings so base case is + + + align:start position:0% +start with empty strings so base case is +that + + align:start position:0% +that + + + align:start position:0% +that +x of i i me + + align:start position:0% +x of i i me + + + align:start position:0% +x of i i me +is vi uh so here i i'm + + align:start position:0% +is vi uh so here i i'm + + + align:start position:0% +is vi uh so here i i'm +i'm inclusive in both ends in this + + align:start position:0% +i'm inclusive in both ends in this + + + align:start position:0% +i'm inclusive in both ends in this +definition + + align:start position:0% +definition + + + align:start position:0% +definition +uh so there is a coin i can take at the + + align:start position:0% +uh so there is a coin i can take at the + + + align:start position:0% +uh so there is a coin i can take at the +end but if you move last and there's one + + align:start position:0% +end but if you move last and there's one + + + align:start position:0% +end but if you move last and there's one +coin left then i don't get it + + align:start position:0% +coin left then i don't get it + + + align:start position:0% +coin left then i don't get it +so it's zero then we have the original + + align:start position:0% +so it's zero then we have the original + + + align:start position:0% +so it's zero then we have the original +problem that is + + align:start position:0% +problem that is + + + align:start position:0% +problem that is +x i j me sorry + + align:start position:0% +x i j me sorry + + + align:start position:0% +x i j me sorry +x zero n that's the + + align:start position:0% +x zero n that's the + + + align:start position:0% +x zero n that's the +entire coin set starting with me that + + align:start position:0% +entire coin set starting with me that + + + align:start position:0% +entire coin set starting with me that +was the problem i wanted to do + + align:start position:0% +was the problem i wanted to do + + + align:start position:0% +was the problem i wanted to do +and then the running time we get is the + + align:start position:0% +and then the running time we get is the + + + align:start position:0% +and then the running time we get is the +number of sub problems that's theta n + + align:start position:0% +number of sub problems that's theta n + + + align:start position:0% +number of sub problems that's theta n +squared + + align:start position:0% +squared + + + align:start position:0% +squared +because we're doing substrings times the + + align:start position:0% +because we're doing substrings times the + + + align:start position:0% +because we're doing substrings times the +amount of non-recursive work i do here + + align:start position:0% +amount of non-recursive work i do here + + + align:start position:0% +amount of non-recursive work i do here +that's just a max of two numbers very + + align:start position:0% +that's just a max of two numbers very + + + align:start position:0% +that's just a max of two numbers very +simple constant time + + align:start position:0% +simple constant time + + + align:start position:0% +simple constant time +so this is quadratic + + align:start position:0% + + + + align:start position:0% + +let me show you an example + + align:start position:0% + + + + align:start position:0% + +this is hard to draw but what i've + + align:start position:0% +this is hard to draw but what i've + + + align:start position:0% +this is hard to draw but what i've +described here is called solution two in + + align:start position:0% +described here is called solution two in + + + align:start position:0% +described here is called solution two in +the notes + + align:start position:0% +the notes + + + align:start position:0% +the notes +um so here's our sequence 510 125 in + + align:start position:0% +um so here's our sequence 510 125 in + + + align:start position:0% +um so here's our sequence 510 125 in +both + + align:start position:0% +both + + + align:start position:0% +both +directions and what we're interested in + + align:start position:0% +directions and what we're interested in + + + align:start position:0% +directions and what we're interested in +is all sub strings so + + align:start position:0% +is all sub strings so + + + align:start position:0% +is all sub strings so +over here i've written the choice for i + + align:start position:0% +over here i've written the choice for i + + + align:start position:0% +over here i've written the choice for i +so we start at one of these and if you + + align:start position:0% +so we start at one of these and if you + + + align:start position:0% +so we start at one of these and if you +start here + + align:start position:0% +start here + + + align:start position:0% +start here +you can't end earlier than there so + + align:start position:0% +you can't end earlier than there so + + + align:start position:0% +you can't end earlier than there so +that's why we're in the upper upper + + align:start position:0% +that's why we're in the upper upper + + + align:start position:0% +that's why we're in the upper upper +diagonal of this matrix + + align:start position:0% +diagonal of this matrix + + + align:start position:0% +diagonal of this matrix +and then there's two versions of each + + align:start position:0% +and then there's two versions of each + + + align:start position:0% +and then there's two versions of each +problem the white version and the blue + + align:start position:0% +problem the white version and the blue + + + align:start position:0% +problem the white version and the blue +version just down and to the right of it + + align:start position:0% +version just down and to the right of it + + + align:start position:0% +version just down and to the right of it +if you can't see what blue is + + align:start position:0% +if you can't see what blue is + + + align:start position:0% +if you can't see what blue is +this is the version where you start this + + align:start position:0% +this is the version where you start this + + + align:start position:0% +this is the version where you start this +is the version where i start + + align:start position:0% +is the version where i start + + + align:start position:0% +is the version where i start +and i've labeled here all of the + + align:start position:0% +and i've labeled here all of the + + + align:start position:0% +and i've labeled here all of the +different numbers please + + align:start position:0% +different numbers please + + + align:start position:0% +different numbers please +admire because this took a long time to + + align:start position:0% +admire because this took a long time to + + + align:start position:0% +admire because this took a long time to +draw but in particular we have 105 here + + align:start position:0% +draw but in particular we have 105 here + + + align:start position:0% +draw but in particular we have 105 here +meaning that the maximum points i can + + align:start position:0% +meaning that the maximum points i can + + + align:start position:0% +meaning that the maximum points i can +get + + align:start position:0% +get + + + align:start position:0% +get +105 and that's the case because + + align:start position:0% +105 and that's the case because + + + align:start position:0% +105 and that's the case because +if we look over there it is the max of + + align:start position:0% +if we look over there it is the max of + + + align:start position:0% +if we look over there it is the max of +these two + + align:start position:0% +these two + + + align:start position:0% +these two +incoming values + + align:start position:0% +incoming values + + + align:start position:0% +incoming values +plus the vi that i get so either i go to + + align:start position:0% +plus the vi that i get so either i go to + + + align:start position:0% +plus the vi that i get so either i go to +the left and i take that + + align:start position:0% +the left and i take that + + + align:start position:0% +the left and i take that +item or i go down and i take that item + + align:start position:0% +item or i go down and i take that item + + + align:start position:0% +item or i go down and i take that item +so the option here is i went + + align:start position:0% +so the option here is i went + + + align:start position:0% +so the option here is i went +to the left and took well that's going + + align:start position:0% +to the left and took well that's going + + + align:start position:0% +to the left and took well that's going +to be tricky to do + + align:start position:0% +to be tricky to do + + + align:start position:0% +to be tricky to do +in time the claim is that the the best + + align:start position:0% +in time the claim is that the the best + + + align:start position:0% +in time the claim is that the the best +answer here is to go here with the + + align:start position:0% +answer here is to go here with the + + + align:start position:0% +answer here is to go here with the +hundred + + align:start position:0% +hundred + + + align:start position:0% +hundred +and take the five uh because going down + + align:start position:0% +and take the five uh because going down + + + align:start position:0% +and take the five uh because going down +corresponds to removing the last item + + align:start position:0% +corresponds to removing the last item + + + align:start position:0% +corresponds to removing the last item +if i went to the left that corresponds + + align:start position:0% +if i went to the left that corresponds + + + align:start position:0% +if i went to the left that corresponds +to remove sorry the first item + + align:start position:0% +to remove sorry the first item + + + align:start position:0% +to remove sorry the first item +if i went to the left that corresponds + + align:start position:0% +if i went to the left that corresponds + + + align:start position:0% +if i went to the left that corresponds +to removing the last item so my options + + align:start position:0% +to removing the last item so my options + + + align:start position:0% +to removing the last item so my options +are + + align:start position:0% +are + + + align:start position:0% +are +10 plus 25 which is 35 versus + + align:start position:0% +10 plus 25 which is 35 versus + + + align:start position:0% +10 plus 25 which is 35 versus +100 plus 5 105 wins + + align:start position:0% +100 plus 5 105 wins + + + align:start position:0% +100 plus 5 105 wins +so that's why there's a red edge here + + align:start position:0% +so that's why there's a red edge here + + + align:start position:0% +so that's why there's a red edge here +showing that was my better choice + + align:start position:0% +showing that was my better choice + + + align:start position:0% +showing that was my better choice +and in general if you follow the these + + align:start position:0% +and in general if you follow the these + + + align:start position:0% +and in general if you follow the these +parent pointers back it gives you the + + align:start position:0% +parent pointers back it gives you the + + + align:start position:0% +parent pointers back it gives you the +optimal strategy + + align:start position:0% +optimal strategy + + + align:start position:0% +optimal strategy +in what you should do first you should + + align:start position:0% +in what you should do first you should + + + align:start position:0% +in what you should do first you should +take the five is what this is saying + + align:start position:0% +take the five is what this is saying + + + align:start position:0% +take the five is what this is saying +because we just clipped off + + align:start position:0% +because we just clipped off + + + align:start position:0% +because we just clipped off +the five we used to start here and now + + align:start position:0% +the five we used to start here and now + + + align:start position:0% +the five we used to start here and now +we start here + + align:start position:0% +we start here + + + align:start position:0% +we start here +in this sub interval then + + align:start position:0% +in this sub interval then + + + align:start position:0% +in this sub interval then +our opponent to be annoying we'll take + + align:start position:0% +our opponent to be annoying we'll take + + + align:start position:0% +our opponent to be annoying we'll take +the 25 + + align:start position:0% +the 25 + + + align:start position:0% +the 25 +doesn't actually matter i think then we + + align:start position:0% +doesn't actually matter i think then we + + + align:start position:0% +doesn't actually matter i think then we +will take the 100 + + align:start position:0% +will take the 100 + + + align:start position:0% +will take the 100 +and then they take the 10 and it's game + + align:start position:0% +and then they take the 10 and it's game + + + align:start position:0% +and then they take the 10 and it's game +over + + align:start position:0% +over + + + align:start position:0% +over +okay all the numbers here how many + + align:start position:0% +okay all the numbers here how many + + + align:start position:0% +okay all the numbers here how many +points we get doesn't say how many + + align:start position:0% +points we get doesn't say how many + + + align:start position:0% +points we get doesn't say how many +points the opponent gets of course you + + align:start position:0% +points the opponent gets of course you + + + align:start position:0% +points the opponent gets of course you +could add that as well + + align:start position:0% +could add that as well + + + align:start position:0% +could add that as well +it's just the total sum minus minus what + + align:start position:0% +it's just the total sum minus minus what + + + align:start position:0% +it's just the total sum minus minus what +we + + align:start position:0% +we + + + align:start position:0% +we +get ah now let me come back to + + align:start position:0% +get ah now let me come back to + + + align:start position:0% +get ah now let me come back to +high level here what we're really doing + + align:start position:0% +high level here what we're really doing + + + align:start position:0% +high level here what we're really doing +is sub problem expansion and this is an + + align:start position:0% +is sub problem expansion and this is an + + + align:start position:0% +is sub problem expansion and this is an +idea + + align:start position:0% +idea + + + align:start position:0% +idea +that we will expand on next lecture + + align:start position:0% + + + + align:start position:0% + +uh and the idea is that sometimes you + + align:start position:0% +uh and the idea is that sometimes you + + + align:start position:0% +uh and the idea is that sometimes you +start with the obvious sub-problems of + + align:start position:0% +start with the obvious sub-problems of + + + align:start position:0% +start with the obvious sub-problems of +prefixes suffixes or substrings here the + + align:start position:0% +prefixes suffixes or substrings here the + + + align:start position:0% +prefixes suffixes or substrings here the +obvious version with substrings because + + align:start position:0% +obvious version with substrings because + + + align:start position:0% +obvious version with substrings because +we're + + align:start position:0% +we're + + + align:start position:0% +we're +removing from both ends if you don't + + align:start position:0% +removing from both ends if you don't + + + align:start position:0% +removing from both ends if you don't +know probably suffixes or prefixes + + align:start position:0% +know probably suffixes or prefixes + + + align:start position:0% +know probably suffixes or prefixes +are enough + + align:start position:0% + + + + align:start position:0% + +so we start there but sometimes that's + + align:start position:0% +so we start there but sometimes that's + + + align:start position:0% +so we start there but sometimes that's +still not enough sub problems + + align:start position:0% +still not enough sub problems + + + align:start position:0% +still not enough sub problems +here as soon as we made a move our + + align:start position:0% +here as soon as we made a move our + + + align:start position:0% +here as soon as we made a move our +problem almost turned upside down + + align:start position:0% +problem almost turned upside down + + + align:start position:0% +problem almost turned upside down +because now it's your turn instead of my + + align:start position:0% +because now it's your turn instead of my + + + align:start position:0% +because now it's your turn instead of my +turn + + align:start position:0% +turn + + + align:start position:0% +turn +and that was just annoying to deal with + + align:start position:0% +and that was just annoying to deal with + + + align:start position:0% +and that was just annoying to deal with +and so we could whenever you + + align:start position:0% +and so we could whenever you + + + align:start position:0% +and so we could whenever you +run into a new type of problem just + + align:start position:0% +run into a new type of problem just + + + align:start position:0% +run into a new type of problem just +build more sub problems as long as it + + align:start position:0% +build more sub problems as long as it + + + align:start position:0% +build more sub problems as long as it +stays polynomial number + + align:start position:0% +stays polynomial number + + + align:start position:0% +stays polynomial number +we'll get polynomial time and so here we + + align:start position:0% +we'll get polynomial time and so here we + + + align:start position:0% +we'll get polynomial time and so here we +doubled the number of sub-problems to + + align:start position:0% +doubled the number of sub-problems to + + + align:start position:0% +doubled the number of sub-problems to +just the b + + align:start position:0% +just the b + + + align:start position:0% +just the b +case and the u-case and that made this + + align:start position:0% +case and the u-case and that made this + + + align:start position:0% +case and the u-case and that made this +recurrence really easy to write in the + + align:start position:0% +recurrence really easy to write in the + + + align:start position:0% +recurrence really easy to write in the +notes you'll see a messier way to write + + align:start position:0% +notes you'll see a messier way to write + + + align:start position:0% +notes you'll see a messier way to write +it if you don't do that + + align:start position:0% +it if you don't do that + + + align:start position:0% +it if you don't do that +in the examples we'll see next lecture + + align:start position:0% +in the examples we'll see next lecture + + + align:start position:0% +in the examples we'll see next lecture +we're going to do a lot more expansion + + align:start position:0% +we're going to do a lot more expansion + + + align:start position:0% +we're going to do a lot more expansion +maybe multiplying the number of sub + + align:start position:0% +maybe multiplying the number of sub + + + align:start position:0% +maybe multiplying the number of sub +problems by n or n squared + + align:start position:0% +problems by n or n squared + + + align:start position:0% +problems by n or n squared +and this will give us uh it will let us + + align:start position:0% +and this will give us uh it will let us + + + align:start position:0% +and this will give us uh it will let us +add more constraints to our + + align:start position:0% +add more constraints to our + + + align:start position:0% +add more constraints to our +sub problems like we did in longest + + align:start position:0% +sub problems like we did in longest + + + align:start position:0% +sub problems like we did in longest +increasing subsequence + + align:start position:0% +increasing subsequence + + + align:start position:0% +increasing subsequence +we added this constraint that we start + + align:start position:0% +we added this constraint that we start + + + align:start position:0% +we added this constraint that we start +with a particular item + + align:start position:0% +with a particular item + + + align:start position:0% +with a particular item +the more sub problems we have we can + + align:start position:0% +the more sub problems we have we can + + + align:start position:0% +the more sub problems we have we can +consider more constraints because we'll + + align:start position:0% +consider more constraints because we'll + + + align:start position:0% +consider more constraints because we'll +just + + align:start position:0% +just + + + align:start position:0% +just +brute force all the possible constraints + + align:start position:0% +brute force all the possible constraints + + + align:start position:0% +brute force all the possible constraints +that could apply + + align:start position:0% +that could apply + + + align:start position:0% +that could apply +well we'll see see more of that next + + align:start position:0% +well we'll see see more of that next + + + align:start position:0% +well we'll see see more of that next +time that's it for today \ No newline at end of file diff --git a/Kdbia6SXSFA.txt b/Kdbia6SXSFA.txt new file mode 100644 index 0000000000000000000000000000000000000000..9fe2bec26c3967d0d071d7064b07d346097128e9 --- /dev/null +++ b/Kdbia6SXSFA.txt @@ -0,0 +1,683 @@ +align:start position:0% + +in this video we'll discuss how we can + + align:start position:0% +in this video we'll discuss how we can + + + align:start position:0% +in this video we'll discuss how we can +create visualizations that are used in + + align:start position:0% +create visualizations that are used in + + + align:start position:0% +create visualizations that are used in +predictive policing models in almost + + align:start position:0% +predictive policing models in almost + + + align:start position:0% +predictive policing models in almost +every application before we even + + align:start position:0% +every application before we even + + + align:start position:0% +every application before we even +consider a predictive model we should + + align:start position:0% +consider a predictive model we should + + + align:start position:0% +consider a predictive model we should +try to understand the historical data + + align:start position:0% +try to understand the historical data + + + align:start position:0% +try to understand the historical data +many cities in the United States and + + align:start position:0% +many cities in the United States and + + + align:start position:0% +many cities in the United States and +around the world + + align:start position:0% +around the world + + + align:start position:0% +around the world +provide logs of reported crimes usually + + align:start position:0% +provide logs of reported crimes usually + + + align:start position:0% +provide logs of reported crimes usually +the time location and nature of the + + align:start position:0% +the time location and nature of the + + + align:start position:0% +the time location and nature of the +event in this lecture we'll use data + + align:start position:0% +event in this lecture we'll use data + + + align:start position:0% +event in this lecture we'll use data +from the city of Chicago in the United + + align:start position:0% +from the city of Chicago in the United + + + align:start position:0% +from the city of Chicago in the United +States about motor vehicle thefts given + + align:start position:0% +States about motor vehicle thefts given + + + align:start position:0% +States about motor vehicle thefts given +this data on crimes suppose we wanted to + + align:start position:0% +this data on crimes suppose we wanted to + + + align:start position:0% +this data on crimes suppose we wanted to +communicate crime patterns over the + + align:start position:0% +communicate crime patterns over the + + + align:start position:0% +communicate crime patterns over the +course of an average week we could + + align:start position:0% +course of an average week we could + + + align:start position:0% +course of an average week we could +display daily crime averages using a + + align:start position:0% +display daily crime averages using a + + + align:start position:0% +display daily crime averages using a +line graph like the one shown here but + + align:start position:0% +line graph like the one shown here but + + + align:start position:0% +line graph like the one shown here but +this doesn't seem too useful we can see + + align:start position:0% +this doesn't seem too useful we can see + + + align:start position:0% +this doesn't seem too useful we can see +that crime tends to be higher on + + align:start position:0% +that crime tends to be higher on + + + align:start position:0% +that crime tends to be higher on +Saturday but when on Saturday and where + + align:start position:0% +Saturday but when on Saturday and where + + + align:start position:0% +Saturday but when on Saturday and where +we could replace our x-axis with the + + align:start position:0% +we could replace our x-axis with the + + + align:start position:0% +we could replace our x-axis with the +hour of the day and have a different + + align:start position:0% +hour of the day and have a different + + + align:start position:0% +hour of the day and have a different +line for every day of the week to + + align:start position:0% +line for every day of the week to + + + align:start position:0% +line for every day of the week to +understand when crime occurs in more + + align:start position:0% +understand when crime occurs in more + + + align:start position:0% +understand when crime occurs in more +detail but this would be a jumbled mess + + align:start position:0% +detail but this would be a jumbled mess + + + align:start position:0% +detail but this would be a jumbled mess +with seven lines and probably very hard + + align:start position:0% +with seven lines and probably very hard + + + align:start position:0% +with seven lines and probably very hard +to read we could instead use no + + align:start position:0% +to read we could instead use no + + + align:start position:0% +to read we could instead use no +visualization at all and instead present + + align:start position:0% +visualization at all and instead present + + + align:start position:0% +visualization at all and instead present +information in a table like the one + + align:start position:0% +information in a table like the one + + + align:start position:0% +information in a table like the one +shown here for each hour and day we have + + align:start position:0% +shown here for each hour and day we have + + + align:start position:0% +shown here for each hour and day we have +the total number of crimes that occurred + + align:start position:0% +the total number of crimes that occurred + + + align:start position:0% +the total number of crimes that occurred +this is a valid representation of the + + align:start position:0% +this is a valid representation of the + + + align:start position:0% +this is a valid representation of the +data but large tables of numbers can be + + align:start position:0% +data but large tables of numbers can be + + + align:start position:0% +data but large tables of numbers can be +hard to read and understand so how can + + align:start position:0% +hard to read and understand so how can + + + align:start position:0% +hard to read and understand so how can +we make the table more interesting and + + align:start position:0% +we make the table more interesting and + + + align:start position:0% +we make the table more interesting and +usable a great way to visualize + + align:start position:0% +usable a great way to visualize + + + align:start position:0% +usable a great way to visualize +information in a two dimensional table + + align:start position:0% +information in a two dimensional table + + + align:start position:0% +information in a two dimensional table +is with a heat map heat maps visualize + + align:start position:0% +is with a heat map heat maps visualize + + + align:start position:0% +is with a heat map heat maps visualize +data using three attributes two of the + + align:start position:0% +data using three attributes two of the + + + align:start position:0% +data using three attributes two of the +attributes are on the X and y axis + + align:start position:0% +attributes are on the X and y axis + + + align:start position:0% +attributes are on the X and y axis +typically displayed horizontally and + + align:start position:0% +typically displayed horizontally and + + + align:start position:0% +typically displayed horizontally and +vertically the third attribute is + + align:start position:0% +vertically the third attribute is + + + align:start position:0% +vertically the third attribute is +represented by shades of color in this + + align:start position:0% +represented by shades of color in this + + + align:start position:0% +represented by shades of color in this +example lower values in the third + + align:start position:0% +example lower values in the third + + + align:start position:0% +example lower values in the third +attribute + + align:start position:0% +attribute + + + align:start position:0% +attribute +correspond to colors closer to blue and + + align:start position:0% +correspond to colors closer to blue and + + + align:start position:0% +correspond to colors closer to blue and +higher values in the third attribute + + align:start position:0% +higher values in the third attribute + + + align:start position:0% +higher values in the third attribute +correspond to colors closer to red for + + align:start position:0% +correspond to colors closer to red for + + + align:start position:0% +correspond to colors closer to red for +example the x-axis could be hours of the + + align:start position:0% +example the x-axis could be hours of the + + + align:start position:0% +example the x-axis could be hours of the +day the y-axis could be days of the week + + align:start position:0% +day the y-axis could be days of the week + + + align:start position:0% +day the y-axis could be days of the week +and the colors could correspond to the + + align:start position:0% +and the colors could correspond to the + + + align:start position:0% +and the colors could correspond to the +amount of crime in a heat map we can + + align:start position:0% +amount of crime in a heat map we can + + + align:start position:0% +amount of crime in a heat map we can +pick different color schemes based on + + align:start position:0% +pick different color schemes based on + + + align:start position:0% +pick different color schemes based on +the type of data to convey different + + align:start position:0% +the type of data to convey different + + + align:start position:0% +the type of data to convey different +messages in crime a yellow to red color + + align:start position:0% +messages in crime a yellow to red color + + + align:start position:0% +messages in crime a yellow to red color +scheme might be appropriate because it + + align:start position:0% +scheme might be appropriate because it + + + align:start position:0% +scheme might be appropriate because it +can highlight some of the more dangerous + + align:start position:0% +can highlight some of the more dangerous + + + align:start position:0% +can highlight some of the more dangerous +areas in red your eye is naturally drawn + + align:start position:0% +areas in red your eye is naturally drawn + + + align:start position:0% +areas in red your eye is naturally drawn +to the red areas of the plot in other + + align:start position:0% +to the red areas of the plot in other + + + align:start position:0% +to the red areas of the plot in other +applications both high and low values + + align:start position:0% +applications both high and low values + + + align:start position:0% +applications both high and low values +are meaningful so having a more varied + + align:start position:0% +are meaningful so having a more varied + + + align:start position:0% +are meaningful so having a more varied +color scheme might be useful and in + + align:start position:0% +color scheme might be useful and in + + + align:start position:0% +color scheme might be useful and in +other applications you might only want + + align:start position:0% +other applications you might only want + + + align:start position:0% +other applications you might only want +to see cells with high values so you + + align:start position:0% +to see cells with high values so you + + + align:start position:0% +to see cells with high values so you +could use a grayscale to make the cells + + align:start position:0% +could use a grayscale to make the cells + + + align:start position:0% +could use a grayscale to make the cells +with low values white the X and y axes + + align:start position:0% +with low values white the X and y axes + + + align:start position:0% +with low values white the X and y axes +in a heat map don't need to be + + align:start position:0% +in a heat map don't need to be + + + align:start position:0% +in a heat map don't need to be +continuous in our example we have a + + align:start position:0% +continuous in our example we have a + + + align:start position:0% +continuous in our example we have a +categorical or factor variable the day + + align:start position:0% +categorical or factor variable the day + + + align:start position:0% +categorical or factor variable the day +of the week and we can even combine a + + align:start position:0% +of the week and we can even combine a + + + align:start position:0% +of the week and we can even combine a +heat map with a geographical map which + + align:start position:0% +heat map with a geographical map which + + + align:start position:0% +heat map with a geographical map which +we'll discuss later in this lecture this + + align:start position:0% +we'll discuss later in this lecture this + + + align:start position:0% +we'll discuss later in this lecture this +type of heat map is frequently used in + + align:start position:0% +type of heat map is frequently used in + + + align:start position:0% +type of heat map is frequently used in +predictive policing to show crime + + align:start position:0% +predictive policing to show crime + + + align:start position:0% +predictive policing to show crime +hotspots in a city in this lecture we'll + + align:start position:0% +hotspots in a city in this lecture we'll + + + align:start position:0% +hotspots in a city in this lecture we'll +use Chicago motor vehicle theft data to + + align:start position:0% +use Chicago motor vehicle theft data to + + + align:start position:0% +use Chicago motor vehicle theft data to +explore patterns of crime both over days + + align:start position:0% +explore patterns of crime both over days + + + align:start position:0% +explore patterns of crime both over days +of the week and over hours of the day + + align:start position:0% +of the week and over hours of the day + + + align:start position:0% +of the week and over hours of the day +we're interested in analyzing the total + + align:start position:0% +we're interested in analyzing the total + + + align:start position:0% +we're interested in analyzing the total +number of car thefts that occur in any + + align:start position:0% +number of car thefts that occur in any + + + align:start position:0% +number of car thefts that occur in any +particular hour of a day of the week + + align:start position:0% +particular hour of a day of the week + + + align:start position:0% +particular hour of a day of the week +over our whole dataset in the next video + + align:start position:0% +over our whole dataset in the next video + + + align:start position:0% +over our whole dataset in the next video +we'll switch to our and start by + + align:start position:0% +we'll switch to our and start by + + + align:start position:0% +we'll switch to our and start by +creating a basic line plot counting the + + align:start position:0% +creating a basic line plot counting the + + + align:start position:0% +creating a basic line plot counting the +total crime by the day of the week \ No newline at end of file diff --git a/KsHOdr5UYZ0.txt b/KsHOdr5UYZ0.txt new file mode 100644 index 0000000000000000000000000000000000000000..0c5c9c3db4307495b7247dba21622daf4aa2c01c --- /dev/null +++ b/KsHOdr5UYZ0.txt @@ -0,0 +1,9379 @@ +align:start position:0% + +before proceeding please view the + + align:start position:0% +before proceeding please view the + + + align:start position:0% +before proceeding please view the +following video + + align:start position:0% +following video + + + align:start position:0% +following video +mashable google's ai assistant can now + + align:start position:0% +mashable google's ai assistant can now + + + align:start position:0% +mashable google's ai assistant can now +make real phone calls + + align:start position:0% +make real phone calls + + + align:start position:0% +make real phone calls +hi everyone my name is brandon lishinsky + + align:start position:0% +hi everyone my name is brandon lishinsky + + + align:start position:0% +hi everyone my name is brandon lishinsky +thank you so much for having me now what + + align:start position:0% +thank you so much for having me now what + + + align:start position:0% +thank you so much for having me now what +we just saw was a very good example of i + + align:start position:0% +we just saw was a very good example of i + + + align:start position:0% +we just saw was a very good example of i +think what most people + + align:start position:0% +think what most people + + + align:start position:0% +think what most people +would call ai + + align:start position:0% +would call ai + + + align:start position:0% +would call ai +uh now let me ask + + align:start position:0% +uh now let me ask + + + align:start position:0% +uh now let me ask +what is ai + + align:start position:0% +what is ai + + + align:start position:0% +what is ai +answers from participants + + align:start position:0% +answers from participants + + + align:start position:0% +answers from participants +artificial intelligence is something + + align:start position:0% +artificial intelligence is something + + + align:start position:0% +artificial intelligence is something +that can learn + + align:start position:0% +that can learn + + + align:start position:0% +that can learn +it's more than a program that follows + + align:start position:0% +it's more than a program that follows + + + align:start position:0% +it's more than a program that follows +rules it's able to adapt + + align:start position:0% +rules it's able to adapt + + + align:start position:0% +rules it's able to adapt +something to make our lives easier + + align:start position:0% +something to make our lives easier + + + align:start position:0% +something to make our lives easier +a machine that simulates human decision + + align:start position:0% +a machine that simulates human decision + + + align:start position:0% +a machine that simulates human decision +making and understanding to a degree + + align:start position:0% +making and understanding to a degree + + + align:start position:0% +making and understanding to a degree +that it's indistinguishable from a human + + align:start position:0% +that it's indistinguishable from a human + + + align:start position:0% +that it's indistinguishable from a human +being + + align:start position:0% +being + + + align:start position:0% +being +so + + align:start position:0% +so + + + align:start position:0% +so +already we're seeing one of the issues + + align:start position:0% +already we're seeing one of the issues + + + align:start position:0% +already we're seeing one of the issues +here is that ai is a very overloaded + + align:start position:0% +here is that ai is a very overloaded + + + align:start position:0% +here is that ai is a very overloaded +term i think most uh typical definitions + + align:start position:0% +term i think most uh typical definitions + + + align:start position:0% +term i think most uh typical definitions +are closest to that last one um that + + align:start position:0% +are closest to that last one um that + + + align:start position:0% +are closest to that last one um that +artificial intelligence is when a + + align:start position:0% +artificial intelligence is when a + + + align:start position:0% +artificial intelligence is when a +machine or a computer can uh + + align:start position:0% +machine or a computer can uh + + + align:start position:0% +machine or a computer can uh +exhibit some signs of human-like + + align:start position:0% +exhibit some signs of human-like + + + align:start position:0% +exhibit some signs of human-like +intelligence + + align:start position:0% + + + + align:start position:0% + +somebody mentioned learning that would + + align:start position:0% +somebody mentioned learning that would + + + align:start position:0% +somebody mentioned learning that would +be a subset of artificial intelligence + + align:start position:0% +be a subset of artificial intelligence + + + align:start position:0% +be a subset of artificial intelligence +which we'll get into um but + + align:start position:0% +which we'll get into um but + + + align:start position:0% +which we'll get into um but +in any case uh part of the point here is + + align:start position:0% +in any case uh part of the point here is + + + align:start position:0% +in any case uh part of the point here is +that ai is a very overloaded term that + + align:start position:0% +that ai is a very overloaded term that + + + align:start position:0% +that ai is a very overloaded term that +can mean a lot of different things to a + + align:start position:0% +can mean a lot of different things to a + + + align:start position:0% +can mean a lot of different things to a +lot of different people and the joke in + + align:start position:0% +lot of different people and the joke in + + + align:start position:0% +lot of different people and the joke in +the ai community is that it's ai until + + align:start position:0% +the ai community is that it's ai until + + + align:start position:0% +the ai community is that it's ai until +we figure out how to do it and then + + align:start position:0% +we figure out how to do it and then + + + align:start position:0% +we figure out how to do it and then +after that is just code + + align:start position:0% +after that is just code + + + align:start position:0% +after that is just code +so + + align:start position:0% +so + + + align:start position:0% +so +uh like i said thank you so much for + + align:start position:0% +uh like i said thank you so much for + + + align:start position:0% +uh like i said thank you so much for +having me my name is brandon i'm a + + align:start position:0% +having me my name is brandon i'm a + + + align:start position:0% +having me my name is brandon i'm a +recent graduate of mit and in today's + + align:start position:0% +recent graduate of mit and in today's + + + align:start position:0% +recent graduate of mit and in today's +workshop uh we'll cover the basics of + + align:start position:0% +workshop uh we'll cover the basics of + + + align:start position:0% +workshop uh we'll cover the basics of +artificial intelligence we'll talk about + + align:start position:0% +artificial intelligence we'll talk about + + + align:start position:0% +artificial intelligence we'll talk about +machine learning we'll train an + + align:start position:0% +machine learning we'll train an + + + align:start position:0% +machine learning we'll train an +algorithm together and i'll leave you + + align:start position:0% +algorithm together and i'll leave you + + + align:start position:0% +algorithm together and i'll leave you +with a couple of questions and a word of + + align:start position:0% +with a couple of questions and a word of + + + align:start position:0% +with a couple of questions and a word of +caution before we get into all of that i + + align:start position:0% +caution before we get into all of that i + + + align:start position:0% +caution before we get into all of that i +want to start with the main takeaway + + align:start position:0% +want to start with the main takeaway + + + align:start position:0% +want to start with the main takeaway +which is with the right data and the + + align:start position:0% +which is with the right data and the + + + align:start position:0% +which is with the right data and the +right model artificial intelligence can + + align:start position:0% +right model artificial intelligence can + + + align:start position:0% +right model artificial intelligence can +solve many problems + + align:start position:0% +solve many problems + + + align:start position:0% +solve many problems +but + + align:start position:0% +but + + + align:start position:0% +but +choosing the right problem + + align:start position:0% +choosing the right problem + + + align:start position:0% +choosing the right problem +finding the right data and training the + + align:start position:0% +finding the right data and training the + + + align:start position:0% +finding the right data and training the +right model can be difficult so there's + + align:start position:0% +right model can be difficult so there's + + + align:start position:0% +right model can be difficult so there's +nothing else that you remember from + + align:start position:0% +nothing else that you remember from + + + align:start position:0% +nothing else that you remember from +today's workshop + + align:start position:0% +today's workshop + + + align:start position:0% +today's workshop +this slide is the key takeaway + + align:start position:0% + + + + align:start position:0% + +and like i said we'll cover artificial + + align:start position:0% +and like i said we'll cover artificial + + + align:start position:0% +and like i said we'll cover artificial +intelligence we will + + align:start position:0% +intelligence we will + + + align:start position:0% +intelligence we will +see a few different examples of tools + + align:start position:0% +see a few different examples of tools + + + align:start position:0% +see a few different examples of tools +that can be used to implement artificial + + align:start position:0% +that can be used to implement artificial + + + align:start position:0% +that can be used to implement artificial +intelligence including something called + + align:start position:0% +intelligence including something called + + + align:start position:0% +intelligence including something called +machine learning we'll talk about + + align:start position:0% +machine learning we'll talk about + + + align:start position:0% +machine learning we'll talk about +different kinds of machine learning and + + align:start position:0% +different kinds of machine learning and + + + align:start position:0% +different kinds of machine learning and +different problems that can be solved by + + align:start position:0% +different problems that can be solved by + + + align:start position:0% +different problems that can be solved by +machine learning and let me just say + + align:start position:0% +machine learning and let me just say + + + align:start position:0% +machine learning and let me just say +since probably a lot of you are already + + align:start position:0% +since probably a lot of you are already + + + align:start position:0% +since probably a lot of you are already +wondering what is deep learning deep + + align:start position:0% +wondering what is deep learning deep + + + align:start position:0% +wondering what is deep learning deep +learning is either a subset or a subset + + align:start position:0% +learning is either a subset or a subset + + + align:start position:0% +learning is either a subset or a subset +of a subset of machine learning + + align:start position:0% +of a subset of machine learning + + + align:start position:0% +of a subset of machine learning +so for those of you who are familiar + + align:start position:0% +so for those of you who are familiar + + + align:start position:0% +so for those of you who are familiar +with neural networks or deep learning + + align:start position:0% +with neural networks or deep learning + + + align:start position:0% +with neural networks or deep learning +that is uh a tool that might be used in + + align:start position:0% +that is uh a tool that might be used in + + + align:start position:0% +that is uh a tool that might be used in +machine learning problems we won't talk + + align:start position:0% +machine learning problems we won't talk + + + align:start position:0% +machine learning problems we won't talk +about that in any depth at all today but + + align:start position:0% +about that in any depth at all today but + + + align:start position:0% +about that in any depth at all today but +i hope that by the end of the workshop + + align:start position:0% +i hope that by the end of the workshop + + + align:start position:0% +i hope that by the end of the workshop +you guys will have the fundamentals + + align:start position:0% +you guys will have the fundamentals + + + align:start position:0% +you guys will have the fundamentals +necessary to dig into deep learning at a + + align:start position:0% +necessary to dig into deep learning at a + + + align:start position:0% +necessary to dig into deep learning at a +conceptual level uh if you want to do + + align:start position:0% +conceptual level uh if you want to do + + + align:start position:0% +conceptual level uh if you want to do +that + + align:start position:0% +that + + + align:start position:0% +that +some other time + + align:start position:0% + + + + align:start position:0% + +all that being said let's get into + + align:start position:0% +all that being said let's get into + + + align:start position:0% +all that being said let's get into +basics of ai + + align:start position:0% +basics of ai + + + align:start position:0% +basics of ai +so ai can be general + + align:start position:0% +so ai can be general + + + align:start position:0% +so ai can be general +or it can be narrow + + align:start position:0% +or it can be narrow + + + align:start position:0% +or it can be narrow +when we talk about general artificial + + align:start position:0% +when we talk about general artificial + + + align:start position:0% +when we talk about general artificial +intelligence it's when a machine can + + align:start position:0% +intelligence it's when a machine can + + + align:start position:0% +intelligence it's when a machine can +learn any task that a human can perform + + align:start position:0% +learn any task that a human can perform + + + align:start position:0% +learn any task that a human can perform +this does not exist there are no + + align:start position:0% +this does not exist there are no + + + align:start position:0% +this does not exist there are no +terminator robots uh there are no there + + align:start position:0% +terminator robots uh there are no there + + + align:start position:0% +terminator robots uh there are no there +are there is no such thing as general ai + + align:start position:0% +are there is no such thing as general ai + + + align:start position:0% +are there is no such thing as general ai +and experts vary widely uh in terms of + + align:start position:0% +and experts vary widely uh in terms of + + + align:start position:0% +and experts vary widely uh in terms of +their predictions on when this may + + align:start position:0% +their predictions on when this may + + + align:start position:0% +their predictions on when this may +actually happen so + + align:start position:0% +actually happen so + + + align:start position:0% +actually happen so +there are some people who say oh like 10 + + align:start position:0% +there are some people who say oh like 10 + + + align:start position:0% +there are some people who say oh like 10 +20 years and there's some people who say + + align:start position:0% +20 years and there's some people who say + + + align:start position:0% +20 years and there's some people who say +not in our lifetimes and some people who + + align:start position:0% +not in our lifetimes and some people who + + + align:start position:0% +not in our lifetimes and some people who +say not ever so really really broad + + align:start position:0% +say not ever so really really broad + + + align:start position:0% +say not ever so really really broad +range of guesses in any case + + align:start position:0% +range of guesses in any case + + + align:start position:0% +range of guesses in any case +most ai + + align:start position:0% +most ai + + + align:start position:0% +most ai +sorry all of the ai that exists today + + align:start position:0% +sorry all of the ai that exists today + + + align:start position:0% +sorry all of the ai that exists today +and most of the ai that you hear people + + align:start position:0% +and most of the ai that you hear people + + + align:start position:0% +and most of the ai that you hear people +talking about + + align:start position:0% +talking about + + + align:start position:0% +talking about +is narrow + + align:start position:0% +is narrow + + + align:start position:0% +is narrow +and narrow ai is when a computer + + align:start position:0% +and narrow ai is when a computer + + + align:start position:0% +and narrow ai is when a computer +exhibits intelligence at one task + + align:start position:0% +exhibits intelligence at one task + + + align:start position:0% +exhibits intelligence at one task +to be clear you can do pretty impressive + + align:start position:0% +to be clear you can do pretty impressive + + + align:start position:0% +to be clear you can do pretty impressive +things with narrow ai + + align:start position:0% +things with narrow ai + + + align:start position:0% +things with narrow ai +a self-driving car for example has one + + align:start position:0% +a self-driving car for example has one + + + align:start position:0% +a self-driving car for example has one +narrow ai system that + + align:start position:0% +narrow ai system that + + + align:start position:0% +narrow ai system that +does vision it looks at the road and + + align:start position:0% +does vision it looks at the road and + + + align:start position:0% +does vision it looks at the road and +interprets things there's another ai + + align:start position:0% +interprets things there's another ai + + + align:start position:0% +interprets things there's another ai +system that does steering that controls + + align:start position:0% +system that does steering that controls + + + align:start position:0% +system that does steering that controls +the car there's another ai system that + + align:start position:0% +the car there's another ai system that + + + align:start position:0% +the car there's another ai system that +does route planning that says on a broad + + align:start position:0% +does route planning that says on a broad + + + align:start position:0% +does route planning that says on a broad +level what are we trying you know where + + align:start position:0% +level what are we trying you know where + + + align:start position:0% +level what are we trying you know where +are we going how do we get there and + + align:start position:0% +are we going how do we get there and + + + align:start position:0% +are we going how do we get there and +when you stitch all those together + + align:start position:0% +when you stitch all those together + + + align:start position:0% +when you stitch all those together +you can actually create a very + + align:start position:0% +you can actually create a very + + + align:start position:0% +you can actually create a very +impressive system but you cannot sit + + align:start position:0% +impressive system but you cannot sit + + + align:start position:0% +impressive system but you cannot sit +this car down and play chess with it + + align:start position:0% +this car down and play chess with it + + + align:start position:0% +this car down and play chess with it +this car will not learn how to paint + + align:start position:0% +this car will not learn how to paint + + + align:start position:0% +this car will not learn how to paint +this car will not + + align:start position:0% +this car will not + + + align:start position:0% +this car will not +learn how to speak russian + + align:start position:0% +learn how to speak russian + + + align:start position:0% +learn how to speak russian +right it's doing a specific set of tasks + + align:start position:0% +right it's doing a specific set of tasks + + + align:start position:0% +right it's doing a specific set of tasks +each of which has been trained + + align:start position:0% +each of which has been trained + + + align:start position:0% +each of which has been trained +separately + + align:start position:0% +separately + + + align:start position:0% +separately +and that is narrow ai + + align:start position:0% +and that is narrow ai + + + align:start position:0% +and that is narrow ai +so from now on when i say ai i'm talking + + align:start position:0% +so from now on when i say ai i'm talking + + + align:start position:0% +so from now on when i say ai i'm talking +about narrow artificial intelligence + + align:start position:0% +about narrow artificial intelligence + + + align:start position:0% +about narrow artificial intelligence +any questions so far + + align:start position:0% +any questions so far + + + align:start position:0% +any questions so far +question from participant + + align:start position:0% +question from participant + + + align:start position:0% +question from participant +what category do you fall in with regard + + align:start position:0% +what category do you fall in with regard + + + align:start position:0% +what category do you fall in with regard +to general ai when do you think it will + + align:start position:0% +to general ai when do you think it will + + + align:start position:0% +to general ai when do you think it will +be possible + + align:start position:0% +be possible + + + align:start position:0% +be possible +uh i don't think it's going to happen + + align:start position:0% +uh i don't think it's going to happen + + + align:start position:0% +uh i don't think it's going to happen +for a while + + align:start position:0% +for a while + + + align:start position:0% +for a while +like many many decades but i also think + + align:start position:0% +like many many decades but i also think + + + align:start position:0% +like many many decades but i also think +that it's definitely + + align:start position:0% +that it's definitely + + + align:start position:0% +that it's definitely +gonna happen at some point + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +many decades to maybe centuries i don't + + align:start position:0% +many decades to maybe centuries i don't + + + align:start position:0% +many decades to maybe centuries i don't +know + + align:start position:0% +know + + + align:start position:0% +know +uh i think technological progress is + + align:start position:0% +uh i think technological progress is + + + align:start position:0% +uh i think technological progress is +hard to guess at so i i think it's a + + align:start position:0% +hard to guess at so i i think it's a + + + align:start position:0% +hard to guess at so i i think it's a +fool's errand um + + align:start position:0% +fool's errand um + + + align:start position:0% +fool's errand um +anyway + + align:start position:0% +anyway + + + align:start position:0% +anyway +so + + align:start position:0% +so + + + align:start position:0% +so +what does narrow ai actually do well + + align:start position:0% +what does narrow ai actually do well + + + align:start position:0% +what does narrow ai actually do well +typical tasks as we've seen with the + + align:start position:0% +typical tasks as we've seen with the + + + align:start position:0% +typical tasks as we've seen with the +self-driving car example include vision + + align:start position:0% +self-driving car example include vision + + + align:start position:0% +self-driving car example include vision +language processing and planning these + + align:start position:0% +language processing and planning these + + + align:start position:0% +language processing and planning these +are just a couple of examples so vision + + align:start position:0% +are just a couple of examples so vision + + + align:start position:0% +are just a couple of examples so vision +is going to be understanding or creating + + align:start position:0% +is going to be understanding or creating + + + align:start position:0% +is going to be understanding or creating +images or video language processing + + align:start position:0% +images or video language processing + + + align:start position:0% +images or video language processing +understanding or creating speech or text + + align:start position:0% +understanding or creating speech or text + + + align:start position:0% +understanding or creating speech or text +that's going to be like siri or amazon + + align:start position:0% +that's going to be like siri or amazon + + + align:start position:0% +that's going to be like siri or amazon +alexa and planning + + align:start position:0% +alexa and planning + + + align:start position:0% +alexa and planning +lots of different kinds of planning you + + align:start position:0% +lots of different kinds of planning you + + + align:start position:0% +lots of different kinds of planning you +can do route planning motion planning + + align:start position:0% +can do route planning motion planning + + + align:start position:0% +can do route planning motion planning +task planning + + align:start position:0% +task planning + + + align:start position:0% +task planning +all these things fall under the category + + align:start position:0% +all these things fall under the category + + + align:start position:0% +all these things fall under the category +of narrow ai tasks that you can train an + + align:start position:0% +of narrow ai tasks that you can train an + + + align:start position:0% +of narrow ai tasks that you can train an +algorithm to do + + align:start position:0% +algorithm to do + + + align:start position:0% +algorithm to do +as far as how we actually build ai + + align:start position:0% +as far as how we actually build ai + + + align:start position:0% +as far as how we actually build ai +there's a lot of different ways + + align:start position:0% +there's a lot of different ways + + + align:start position:0% +there's a lot of different ways +two + + align:start position:0% +two + + + align:start position:0% +two +classical ways to implement artificial + + align:start position:0% +classical ways to implement artificial + + + align:start position:0% +classical ways to implement artificial +intelligence + + align:start position:0% +intelligence + + + align:start position:0% +intelligence +and i remember learning about this and + + align:start position:0% +and i remember learning about this and + + + align:start position:0% +and i remember learning about this and +being like wow this is not intelligent + + align:start position:0% +being like wow this is not intelligent + + + align:start position:0% +being like wow this is not intelligent +at all this is super dumb uh r expert + + align:start position:0% +at all this is super dumb uh r expert + + + align:start position:0% +at all this is super dumb uh r expert +systems and tree search so in an expert + + align:start position:0% +systems and tree search so in an expert + + + align:start position:0% +systems and tree search so in an expert +system it's just a person writing a list + + align:start position:0% +system it's just a person writing a list + + + align:start position:0% +system it's just a person writing a list +of rules if this then that if this and + + align:start position:0% +of rules if this then that if this and + + + align:start position:0% +of rules if this then that if this and +that + + align:start position:0% +that + + + align:start position:0% +that +this can be super useful for + + align:start position:0% +this can be super useful for + + + align:start position:0% +this can be super useful for +certain problems + + align:start position:0% +certain problems + + + align:start position:0% +certain problems +um + + align:start position:0% +um + + + align:start position:0% +um +but + + align:start position:0% +but + + + align:start position:0% +but +a lot of the things that we actually + + align:start position:0% +a lot of the things that we actually + + + align:start position:0% +a lot of the things that we actually +think of as really straightforward turn + + align:start position:0% +think of as really straightforward turn + + + align:start position:0% +think of as really straightforward turn +out to be quite difficult + + align:start position:0% +out to be quite difficult + + + align:start position:0% +out to be quite difficult +so for example + + align:start position:0% + + + + align:start position:0% + +we can identify a table + + align:start position:0% +we can identify a table + + + align:start position:0% +we can identify a table +like that very very easily we know what + + align:start position:0% +like that very very easily we know what + + + align:start position:0% +like that very very easily we know what +a table is + + align:start position:0% +a table is + + + align:start position:0% +a table is +but i challenge you to write a list of + + align:start position:0% +but i challenge you to write a list of + + + align:start position:0% +but i challenge you to write a list of +rules that can define a table + + align:start position:0% +rules that can define a table + + + align:start position:0% +rules that can define a table +what color is it what's it made of how + + align:start position:0% +what color is it what's it made of how + + + align:start position:0% +what color is it what's it made of how +many legs does it have what shape is it + + align:start position:0% + + + + align:start position:0% + +so it turns out that even something like + + align:start position:0% +so it turns out that even something like + + + align:start position:0% +so it turns out that even something like +what is a table becomes really really + + align:start position:0% +what is a table becomes really really + + + align:start position:0% +what is a table becomes really really +challenging to answer using an expert + + align:start position:0% +challenging to answer using an expert + + + align:start position:0% +challenging to answer using an expert +system so these can be really helpful + + align:start position:0% +system so these can be really helpful + + + align:start position:0% +system so these can be really helpful +and there are some simple ways rather + + align:start position:0% +and there are some simple ways rather + + + align:start position:0% +and there are some simple ways rather +there are some problems where heuristics + + align:start position:0% +there are some problems where heuristics + + + align:start position:0% +there are some problems where heuristics +are actually the best way to do it + + align:start position:0% +are actually the best way to do it + + + align:start position:0% +are actually the best way to do it +because it's interpretable you know it's + + align:start position:0% +because it's interpretable you know it's + + + align:start position:0% +because it's interpretable you know it's +going to happen and you don't need a + + align:start position:0% +going to happen and you don't need a + + + align:start position:0% +going to happen and you don't need a +neural network for every problem + + align:start position:0% +neural network for every problem + + + align:start position:0% +neural network for every problem +but this definitely can't solve every + + align:start position:0% +but this definitely can't solve every + + + align:start position:0% +but this definitely can't solve every +problem either + + align:start position:0% + + + + align:start position:0% + +another kind of + + align:start position:0% + + + + align:start position:0% + +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +people might use in classical ai is + + align:start position:0% +people might use in classical ai is + + + align:start position:0% +people might use in classical ai is +called the tree search you start in your + + align:start position:0% +called the tree search you start in your + + + align:start position:0% +called the tree search you start in your +current state that's state a and you + + align:start position:0% +current state that's state a and you + + + align:start position:0% +current state that's state a and you +enumerate all the possible options from + + align:start position:0% +enumerate all the possible options from + + + align:start position:0% +enumerate all the possible options from +there and then you just repeat that for + + align:start position:0% +there and then you just repeat that for + + + align:start position:0% +there and then you just repeat that for +each state + + align:start position:0% +each state + + + align:start position:0% +each state +until you find + + align:start position:0% +until you find + + + align:start position:0% +until you find +a state where you want to end up in your + + align:start position:0% +a state where you want to end up in your + + + align:start position:0% +a state where you want to end up in your +goal state + + align:start position:0% +goal state + + + align:start position:0% +goal state +now + + align:start position:0% +now + + + align:start position:0% +now +obvious problem here + + align:start position:0% +obvious problem here + + + align:start position:0% +obvious problem here +a lot of options a lot of options when + + align:start position:0% +a lot of options a lot of options when + + + align:start position:0% +a lot of options a lot of options when +you're operating in the real world + + align:start position:0% +you're operating in the real world + + + align:start position:0% +you're operating in the real world +so how do you actually enumerate all of + + align:start position:0% +so how do you actually enumerate all of + + + align:start position:0% +so how do you actually enumerate all of +them + + align:start position:0% +them + + + align:start position:0% +them +and sometimes it can even be difficult + + align:start position:0% +and sometimes it can even be difficult + + + align:start position:0% +and sometimes it can even be difficult +to define a goal state right when i'm + + align:start position:0% +to define a goal state right when i'm + + + align:start position:0% +to define a goal state right when i'm +playing chess i know there's a goal + + align:start position:0% +playing chess i know there's a goal + + + align:start position:0% +playing chess i know there's a goal +state of win checkmate + + align:start position:0% +state of win checkmate + + + align:start position:0% +state of win checkmate +but + + align:start position:0% +but + + + align:start position:0% +but +in real life environments it's not so + + align:start position:0% +in real life environments it's not so + + + align:start position:0% +in real life environments it's not so +simple + + align:start position:0% +simple + + + align:start position:0% +simple +so again can be really really helpful + + align:start position:0% +so again can be really really helpful + + + align:start position:0% +so again can be really really helpful +and this is how + + align:start position:0% +and this is how + + + align:start position:0% +and this is how +the uh chess computers beat gary + + align:start position:0% +the uh chess computers beat gary + + + align:start position:0% +the uh chess computers beat gary +kasparov + + align:start position:0% + + + + align:start position:0% + +but also limited + + align:start position:0% + + + + align:start position:0% + +so now we see these are just two ways to + + align:start position:0% +so now we see these are just two ways to + + + align:start position:0% +so now we see these are just two ways to +implement ai they're not that smart + + align:start position:0% +implement ai they're not that smart + + + align:start position:0% +implement ai they're not that smart +right like + + align:start position:0% +right like + + + align:start position:0% +right like +most of us could have come up with these + + align:start position:0% +most of us could have come up with these + + + align:start position:0% +most of us could have come up with these +if we were just told like + + align:start position:0% +if we were just told like + + + align:start position:0% +if we were just told like +you know come up with a way to solve + + align:start position:0% +you know come up with a way to solve + + + align:start position:0% +you know come up with a way to solve +this problem we probably would have + + align:start position:0% +this problem we probably would have + + + align:start position:0% +this problem we probably would have +figured out that + + align:start position:0% +figured out that + + + align:start position:0% +figured out that +a list of rules or enumerating all the + + align:start position:0% +a list of rules or enumerating all the + + + align:start position:0% +a list of rules or enumerating all the +options yeah that makes sense + + align:start position:0% +options yeah that makes sense + + + align:start position:0% +options yeah that makes sense +so let's now move into machine learning + + align:start position:0% +so let's now move into machine learning + + + align:start position:0% +so let's now move into machine learning +which is a subset of artificial + + align:start position:0% +which is a subset of artificial + + + align:start position:0% +which is a subset of artificial +intelligence that allows a machine to + + align:start position:0% +intelligence that allows a machine to + + + align:start position:0% +intelligence that allows a machine to +learn automatically from data and this + + align:start position:0% +learn automatically from data and this + + + align:start position:0% +learn automatically from data and this +is what somebody else mentioned so this + + align:start position:0% +is what somebody else mentioned so this + + + align:start position:0% +is what somebody else mentioned so this +is where there's not a programmer who's + + align:start position:0% +is where there's not a programmer who's + + + align:start position:0% +is where there's not a programmer who's +sitting there explicitly programming or + + align:start position:0% +sitting there explicitly programming or + + + align:start position:0% +sitting there explicitly programming or +changing the code changing the model + + align:start position:0% +changing the code changing the model + + + align:start position:0% +changing the code changing the model +it's like oh well if this happens and + + align:start position:0% +it's like oh well if this happens and + + + align:start position:0% +it's like oh well if this happens and +you should actually do that it is + + align:start position:0% +you should actually do that it is + + + align:start position:0% +you should actually do that it is +learning automatically by looking at + + align:start position:0% +learning automatically by looking at + + + align:start position:0% +learning automatically by looking at +data and i'll say more about learning in + + align:start position:0% +data and i'll say more about learning in + + + align:start position:0% +data and i'll say more about learning in +just a second but let me just first + + align:start position:0% +just a second but let me just first + + + align:start position:0% +just a second but let me just first +answer the question of when do we use + + align:start position:0% +answer the question of when do we use + + + align:start position:0% +answer the question of when do we use +machine learning + + align:start position:0% + + + + align:start position:0% + +so machine learning can perform many + + align:start position:0% +so machine learning can perform many + + + align:start position:0% +so machine learning can perform many +different tasks + + align:start position:0% +different tasks + + + align:start position:0% +different tasks +three of the most common are + + align:start position:0% +three of the most common are + + + align:start position:0% +three of the most common are +classification clustering and regression + + align:start position:0% +classification clustering and regression + + + align:start position:0% +classification clustering and regression +classification means + + align:start position:0% +classification means + + + align:start position:0% +classification means +here's some input data + + align:start position:0% +here's some input data + + + align:start position:0% +here's some input data +i'm going to give you an output of a + + align:start position:0% +i'm going to give you an output of a + + + align:start position:0% +i'm going to give you an output of a +class + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +maybe it's an image and i tell you what + + align:start position:0% +maybe it's an image and i tell you what + + + align:start position:0% +maybe it's an image and i tell you what +kind of animal it is maybe it's a list + + align:start position:0% +kind of animal it is maybe it's a list + + + align:start position:0% +kind of animal it is maybe it's a list +of information about somebody and i tell + + align:start position:0% +of information about somebody and i tell + + + align:start position:0% +of information about somebody and i tell +you whether they're a threat or not + + align:start position:0% + + + + align:start position:0% + +you give me an input i give you a class + + align:start position:0% +you give me an input i give you a class + + + align:start position:0% +you give me an input i give you a class +clustering + + align:start position:0% +clustering + + + align:start position:0% +clustering +is + + align:start position:0% + + + + align:start position:0% + +again you give me some kind of input + + align:start position:0% +again you give me some kind of input + + + align:start position:0% +again you give me some kind of input +and i'm going to find clusters i'm going + + align:start position:0% +and i'm going to find clusters i'm going + + + align:start position:0% +and i'm going to find clusters i'm going +to find things that are similar maybe + + align:start position:0% +to find things that are similar maybe + + + align:start position:0% +to find things that are similar maybe +i'm clustering different groups of + + align:start position:0% +i'm clustering different groups of + + + align:start position:0% +i'm clustering different groups of +animals or other similar groups of + + align:start position:0% +animals or other similar groups of + + + align:start position:0% +animals or other similar groups of +animals together maybe it's similar gene + + align:start position:0% +animals together maybe it's similar gene + + + align:start position:0% +animals together maybe it's similar gene +sequences oh like these these look + + align:start position:0% +sequences oh like these these look + + + align:start position:0% +sequences oh like these these look +related somehow + + align:start position:0% + + + + align:start position:0% + +so clustering can be really useful + + align:start position:0% +so clustering can be really useful + + + align:start position:0% +so clustering can be really useful +especially in genetics from what i've + + align:start position:0% +especially in genetics from what i've + + + align:start position:0% +especially in genetics from what i've +heard + + align:start position:0% +heard + + + align:start position:0% +heard +not that i've ever done that + + align:start position:0% +not that i've ever done that + + + align:start position:0% +not that i've ever done that +and then another kind of problem is + + align:start position:0% +and then another kind of problem is + + + align:start position:0% +and then another kind of problem is +regression aggression regression is + + align:start position:0% +regression aggression regression is + + + align:start position:0% +regression aggression regression is +again you get input data but instead of + + align:start position:0% +again you get input data but instead of + + + align:start position:0% +again you get input data but instead of +outputting a class like dog or + + align:start position:0% +outputting a class like dog or + + + align:start position:0% +outputting a class like dog or +uh safe + + align:start position:0% +uh safe + + + align:start position:0% +uh safe +you output a numerical prediction + + align:start position:0% +you output a numerical prediction + + + align:start position:0% +you output a numerical prediction +so maybe you're predicting home price + + align:start position:0% +so maybe you're predicting home price + + + align:start position:0% +so maybe you're predicting home price +based on square footage maybe you're + + align:start position:0% +based on square footage maybe you're + + + align:start position:0% +based on square footage maybe you're +predicting crime rate based on location + + align:start position:0% + + + + align:start position:0% + +and in this example let me just ask you + + align:start position:0% +and in this example let me just ask you + + + align:start position:0% +and in this example let me just ask you +guys a question what's the model that + + align:start position:0% +guys a question what's the model that + + + align:start position:0% +guys a question what's the model that +we're using + + align:start position:0% +we're using + + + align:start position:0% +we're using +what's the model + + align:start position:0% +what's the model + + + align:start position:0% +what's the model +the machine technically it's a machine + + align:start position:0% +the machine technically it's a machine + + + align:start position:0% +the machine technically it's a machine +learning model + + align:start position:0% +learning model + + + align:start position:0% +learning model +or you can call it that what's the model + + align:start position:0% +or you can call it that what's the model + + + align:start position:0% +or you can call it that what's the model +that we've trained in this example + + align:start position:0% +that we've trained in this example + + + align:start position:0% +that we've trained in this example +what's actually doing the prediction + + align:start position:0% +what's actually doing the prediction + + + align:start position:0% +what's actually doing the prediction +answer from participant + + align:start position:0% +answer from participant + + + align:start position:0% +answer from participant +the red line + + align:start position:0% +the red line + + + align:start position:0% +the red line +exactly it's a line + + align:start position:0% +exactly it's a line + + + align:start position:0% +exactly it's a line +right so so i just and i just want to + + align:start position:0% +right so so i just and i just want to + + + align:start position:0% +right so so i just and i just want to +say this because i think a lot of people + + align:start position:0% +say this because i think a lot of people + + + align:start position:0% +say this because i think a lot of people +think models are like really complicated + + align:start position:0% +think models are like really complicated + + + align:start position:0% +think models are like really complicated +sometimes a model is just a line like + + align:start position:0% +sometimes a model is just a line like + + + align:start position:0% +sometimes a model is just a line like +this is a model right i give it some + + align:start position:0% +this is a model right i give it some + + + align:start position:0% +this is a model right i give it some +kind of input and it gives me an output + + align:start position:0% +kind of input and it gives me an output + + + align:start position:0% +kind of input and it gives me an output +this is a model + + align:start position:0% +this is a model + + + align:start position:0% +this is a model +you can also use a curve + + align:start position:0% +you can also use a curve + + + align:start position:0% +you can also use a curve +you can use a neural network it's way + + align:start position:0% +you can use a neural network it's way + + + align:start position:0% +you can use a neural network it's way +more complicated a lot more operations + + align:start position:0% +more complicated a lot more operations + + + align:start position:0% +more complicated a lot more operations +there but these are all models + + align:start position:0% +there but these are all models + + + align:start position:0% +there but these are all models +so + + align:start position:0% +so + + + align:start position:0% +so +like i said machine learning can perform + + align:start position:0% +like i said machine learning can perform + + + align:start position:0% +like i said machine learning can perform +many tasks classification clustering and + + align:start position:0% +many tasks classification clustering and + + + align:start position:0% +many tasks classification clustering and +regression are the most commonly + + align:start position:0% +regression are the most commonly + + + align:start position:0% +regression are the most commonly +performed and now i want to talk a + + align:start position:0% +performed and now i want to talk a + + + align:start position:0% +performed and now i want to talk a +little bit about what it actually means + + align:start position:0% +little bit about what it actually means + + + align:start position:0% +little bit about what it actually means +to learn something + + align:start position:0% +to learn something + + + align:start position:0% +to learn something +what does it mean for a machine to learn + + align:start position:0% +what does it mean for a machine to learn + + + align:start position:0% +what does it mean for a machine to learn +are there any questions i'll tell this + + align:start position:0% +are there any questions i'll tell this + + + align:start position:0% +are there any questions i'll tell this +point + + align:start position:0% + + + + align:start position:0% + +question from participant + + align:start position:0% +question from participant + + + align:start position:0% +question from participant +where does a convolutional network fall + + align:start position:0% +where does a convolutional network fall + + + align:start position:0% +where does a convolutional network fall +in the scheme of things + + align:start position:0% +in the scheme of things + + + align:start position:0% +in the scheme of things +so convolutional neural networks are a + + align:start position:0% +so convolutional neural networks are a + + + align:start position:0% +so convolutional neural networks are a +very specific tool that are used usually + + align:start position:0% +very specific tool that are used usually + + + align:start position:0% +very specific tool that are used usually +in computer vision + + align:start position:0% +in computer vision + + + align:start position:0% +in computer vision +that is a model + + align:start position:0% +that is a model + + + align:start position:0% +that is a model +and + + align:start position:0% +and + + + align:start position:0% +and +we will + + align:start position:0% +we will + + + align:start position:0% +we will +let me let me get back to convolutional + + align:start position:0% +let me let me get back to convolutional + + + align:start position:0% +let me let me get back to convolutional +neural networks after this section i'll + + align:start position:0% +neural networks after this section i'll + + + align:start position:0% +neural networks after this section i'll +talk briefly about them so three types + + align:start position:0% +talk briefly about them so three types + + + align:start position:0% +talk briefly about them so three types +of learning guys there's supervised + + align:start position:0% +of learning guys there's supervised + + + align:start position:0% +of learning guys there's supervised +unsupervised and reinforcement learning + + align:start position:0% +unsupervised and reinforcement learning + + + align:start position:0% +unsupervised and reinforcement learning +when we talk about supervised learning + + align:start position:0% +when we talk about supervised learning + + + align:start position:0% +when we talk about supervised learning +it's really like studying for a test i'm + + align:start position:0% +it's really like studying for a test i'm + + + align:start position:0% +it's really like studying for a test i'm +going to give you the example sorry i'm + + align:start position:0% +going to give you the example sorry i'm + + + align:start position:0% +going to give you the example sorry i'm +going to give you the the questions and + + align:start position:0% +going to give you the the questions and + + + align:start position:0% +going to give you the the questions and +the answers in advance you're going to + + align:start position:0% +the answers in advance you're going to + + + align:start position:0% +the answers in advance you're going to +study them you're going to figure out + + align:start position:0% +study them you're going to figure out + + + align:start position:0% +study them you're going to figure out +what the broad patterns are and then i'm + + align:start position:0% +what the broad patterns are and then i'm + + + align:start position:0% +what the broad patterns are and then i'm +going to test you + + align:start position:0% +going to test you + + + align:start position:0% +going to test you +this is often doesn't have to but it's + + align:start position:0% +this is often doesn't have to but it's + + + align:start position:0% +this is often doesn't have to but it's +often applied to classification problems + + align:start position:0% +often applied to classification problems + + + align:start position:0% +often applied to classification problems +now the key thing here is that in + + align:start position:0% +now the key thing here is that in + + + align:start position:0% +now the key thing here is that in +supervised learning you need to have the + + align:start position:0% +supervised learning you need to have the + + + align:start position:0% +supervised learning you need to have the +answers in advance + + align:start position:0% + + + + align:start position:0% + +you need to have + + align:start position:0% +you need to have + + + align:start position:0% +you need to have +labeled data in other words i need to + + align:start position:0% +labeled data in other words i need to + + + align:start position:0% +labeled data in other words i need to +it's not enough for me to just show the + + align:start position:0% +it's not enough for me to just show the + + + align:start position:0% +it's not enough for me to just show the +model a bunch of images the images have + + align:start position:0% +model a bunch of images the images have + + + align:start position:0% +model a bunch of images the images have +to be labeled as cat + + align:start position:0% +to be labeled as cat + + + align:start position:0% +to be labeled as cat +cow giraffe dog whatever threat not + + align:start position:0% +cow giraffe dog whatever threat not + + + align:start position:0% +cow giraffe dog whatever threat not +threat there have to be answers + + align:start position:0% +threat there have to be answers + + + align:start position:0% +threat there have to be answers +otherwise it'd be like giving you flash + + align:start position:0% +otherwise it'd be like giving you flash + + + align:start position:0% +otherwise it'd be like giving you flash +cards with only one side you're turning + + align:start position:0% +cards with only one side you're turning + + + align:start position:0% +cards with only one side you're turning +it over and you're like i have no idea + + align:start position:0% + + + + align:start position:0% + +so that's what supervised learning is + + align:start position:0% +so that's what supervised learning is + + + align:start position:0% +so that's what supervised learning is +in unsupervised learning + + align:start position:0% +in unsupervised learning + + + align:start position:0% +in unsupervised learning +it's more + + align:start position:0% +it's more + + + align:start position:0% +it's more +you don't have those answers you don't + + align:start position:0% +you don't have those answers you don't + + + align:start position:0% +you don't have those answers you don't +have those labels it's more like a baby + + align:start position:0% +have those labels it's more like a baby + + + align:start position:0% +have those labels it's more like a baby +playing you're just discovering patterns + + align:start position:0% +playing you're just discovering patterns + + + align:start position:0% +playing you're just discovering patterns +this is often used in clustering i don't + + align:start position:0% +this is often used in clustering i don't + + + align:start position:0% +this is often used in clustering i don't +know a priori what the right clusters + + align:start position:0% +know a priori what the right clusters + + + align:start position:0% +know a priori what the right clusters +are going to look like i have no idea + + align:start position:0% +are going to look like i have no idea + + + align:start position:0% +are going to look like i have no idea +what they should look like all i know is + + align:start position:0% +what they should look like all i know is + + + align:start position:0% +what they should look like all i know is +oh these looks something + + align:start position:0% +oh these looks something + + + align:start position:0% +oh these looks something +they look somewhat similar + + align:start position:0% + + + + align:start position:0% + +these look somewhat similar and they + + align:start position:0% +these look somewhat similar and they + + + align:start position:0% +these look somewhat similar and they +look kind of different from each other + + align:start position:0% +look kind of different from each other + + + align:start position:0% +look kind of different from each other +but but i have no external source of + + align:start position:0% +but but i have no external source of + + + align:start position:0% +but but i have no external source of +information as far as what kind of class + + align:start position:0% +information as far as what kind of class + + + align:start position:0% +information as far as what kind of class +this belongs to does this make sense + + align:start position:0% + + + + align:start position:0% + +so that's unsupervised learning and then + + align:start position:0% +so that's unsupervised learning and then + + + align:start position:0% +so that's unsupervised learning and then +the last kind of learning that we'll + + align:start position:0% +the last kind of learning that we'll + + + align:start position:0% +the last kind of learning that we'll +talk about is reinforcement learning + + align:start position:0% +talk about is reinforcement learning + + + align:start position:0% +talk about is reinforcement learning +reinforcement learning is again you + + align:start position:0% +reinforcement learning is again you + + + align:start position:0% +reinforcement learning is again you +don't really have a right answer and + + align:start position:0% +don't really have a right answer and + + + align:start position:0% +don't really have a right answer and +you're not really playing either you're + + align:start position:0% +you're not really playing either you're + + + align:start position:0% +you're not really playing either you're +it's something + + align:start position:0% +it's something + + + align:start position:0% +it's something +separate you are aiming to reward some + + align:start position:0% +separate you are aiming to reward some + + + align:start position:0% +separate you are aiming to reward some +kind of behavior or some kind of + + align:start position:0% +kind of behavior or some kind of + + + align:start position:0% +kind of behavior or some kind of +solution to a problem it's like a rat + + align:start position:0% +solution to a problem it's like a rat + + + align:start position:0% +solution to a problem it's like a rat +and a maze you give it cheese + + align:start position:0% +and a maze you give it cheese + + + align:start position:0% +and a maze you give it cheese +and it discovers winning strategies on + + align:start position:0% +and it discovers winning strategies on + + + align:start position:0% +and it discovers winning strategies on +its own + + align:start position:0% +its own + + + align:start position:0% +its own +so you don't have the right answer you + + align:start position:0% +so you don't have the right answer you + + + align:start position:0% +so you don't have the right answer you +just know that you need the thing to get + + align:start position:0% +just know that you need the thing to get + + + align:start position:0% +just know that you need the thing to get +out of the maze + + align:start position:0% +out of the maze + + + align:start position:0% +out of the maze +this is often used in robotics for + + align:start position:0% +this is often used in robotics for + + + align:start position:0% +this is often used in robotics for +example with training a robotic arm + + align:start position:0% + + + + align:start position:0% + +or maybe training an agent in a game + + align:start position:0% + + + + align:start position:0% + +so supervised + + align:start position:0% +so supervised + + + align:start position:0% +so supervised +unsupervised reinforcement learning + + align:start position:0% +unsupervised reinforcement learning + + + align:start position:0% +unsupervised reinforcement learning +these are the three + + align:start position:0% +these are the three + + + align:start position:0% +these are the three +ways + + align:start position:0% +ways + + + align:start position:0% +ways +to + + align:start position:0% +to + + + align:start position:0% +to +learn + + align:start position:0% +learn + + + align:start position:0% +learn +in machine learning any questions about + + align:start position:0% +in machine learning any questions about + + + align:start position:0% +in machine learning any questions about +these three things + + align:start position:0% + + + + align:start position:0% + +question from participant + + align:start position:0% +question from participant + + + align:start position:0% +question from participant +is reinforcement learning where we know + + align:start position:0% +is reinforcement learning where we know + + + align:start position:0% +is reinforcement learning where we know +what we wanted to do and technology + + align:start position:0% +what we wanted to do and technology + + + align:start position:0% +what we wanted to do and technology +figures out avenues with parameters to + + align:start position:0% +figures out avenues with parameters to + + + align:start position:0% +figures out avenues with parameters to +get there + + align:start position:0% + + + + align:start position:0% + +exactly + + align:start position:0% + + + + align:start position:0% + +so you might for example say + + align:start position:0% + + + + align:start position:0% + +win this game + + align:start position:0% +win this game + + + align:start position:0% +win this game +and over the course of a million + + align:start position:0% +and over the course of a million + + + align:start position:0% +and over the course of a million +simulations + + align:start position:0% +simulations + + + align:start position:0% +simulations +the thing learns oh like this + + align:start position:0% +the thing learns oh like this + + + align:start position:0% +the thing learns oh like this +probably you know probabilistically this + + align:start position:0% +probably you know probabilistically this + + + align:start position:0% +probably you know probabilistically this +has a good chance of winning the game + + align:start position:0% +has a good chance of winning the game + + + align:start position:0% +has a good chance of winning the game +this does not let me do this thing now + + align:start position:0% +this does not let me do this thing now + + + align:start position:0% +this does not let me do this thing now +let me just actually add about + + align:start position:0% +let me just actually add about + + + align:start position:0% +let me just actually add about +reinforcement learning all of these all + + align:start position:0% +reinforcement learning all of these all + + + align:start position:0% +reinforcement learning all of these all +these types of learnings have uh pros + + align:start position:0% +these types of learnings have uh pros + + + align:start position:0% +these types of learnings have uh pros +and cons of course um + + align:start position:0% +and cons of course um + + + align:start position:0% +and cons of course um +uh so + + align:start position:0% +uh so + + + align:start position:0% +uh so +with supervised learning um the + + align:start position:0% +with supervised learning um the + + + align:start position:0% +with supervised learning um the +trade-off is you need just + + align:start position:0% +trade-off is you need just + + + align:start position:0% +trade-off is you need just +like a stupid amount of labeled data and + + align:start position:0% +like a stupid amount of labeled data and + + + align:start position:0% +like a stupid amount of labeled data and +that takes forever that it can be very + + align:start position:0% +that takes forever that it can be very + + + align:start position:0% +that takes forever that it can be very +very expensive to collect and label data + + align:start position:0% +very expensive to collect and label data + + + align:start position:0% +very expensive to collect and label data +uh with unsupervised learning you don't + + align:start position:0% +uh with unsupervised learning you don't + + + align:start position:0% +uh with unsupervised learning you don't +necessarily know what the right answer + + align:start position:0% +necessarily know what the right answer + + + align:start position:0% +necessarily know what the right answer +is so it can help you discover patterns + + align:start position:0% +is so it can help you discover patterns + + + align:start position:0% +is so it can help you discover patterns +but it may not be as powerful as + + align:start position:0% +but it may not be as powerful as + + + align:start position:0% +but it may not be as powerful as +supervised learning and with + + align:start position:0% +supervised learning and with + + + align:start position:0% +supervised learning and with +reinforcement learning the real trick is + + align:start position:0% +reinforcement learning the real trick is + + + align:start position:0% +reinforcement learning the real trick is +how good is your simulation because + + align:start position:0% +how good is your simulation because + + + align:start position:0% +how good is your simulation because +you're not going to take a real car + + align:start position:0% +you're not going to take a real car + + + align:start position:0% +you're not going to take a real car +and + + align:start position:0% +and + + + align:start position:0% +and +do reinforcement learning with a real + + align:start position:0% +do reinforcement learning with a real + + + align:start position:0% +do reinforcement learning with a real +car + + align:start position:0% +car + + + align:start position:0% +car +right it's going to take you a million + + align:start position:0% +right it's going to take you a million + + + align:start position:0% +right it's going to take you a million +iterations you're going to have to go + + align:start position:0% +iterations you're going to have to go + + + align:start position:0% +iterations you're going to have to go +through a million cars before it learns + + align:start position:0% +through a million cars before it learns + + + align:start position:0% +through a million cars before it learns +how to drive without crashing + + align:start position:0% +how to drive without crashing + + + align:start position:0% +how to drive without crashing +when you simulate it then the question + + align:start position:0% +when you simulate it then the question + + + align:start position:0% +when you simulate it then the question +is how good is your simulation + + align:start position:0% +is how good is your simulation + + + align:start position:0% +is how good is your simulation +can you know like will it actually apply + + align:start position:0% +can you know like will it actually apply + + + align:start position:0% +can you know like will it actually apply +to the real world are you capturing all + + align:start position:0% +to the real world are you capturing all + + + align:start position:0% +to the real world are you capturing all +the noise all the disturbances all the + + align:start position:0% +the noise all the disturbances all the + + + align:start position:0% +the noise all the disturbances all the +possibilities + + align:start position:0% +possibilities + + + align:start position:0% +possibilities +are you capturing that biker who cuts + + align:start position:0% +are you capturing that biker who cuts + + + align:start position:0% +are you capturing that biker who cuts +you off + + align:start position:0% +you off + + + align:start position:0% +you off +or the wind or + + align:start position:0% +or the wind or + + + align:start position:0% +or the wind or +the reflection of the + + align:start position:0% +the reflection of the + + + align:start position:0% +the reflection of the +sun on a white sign + + align:start position:0% +sun on a white sign + + + align:start position:0% +sun on a white sign +so + + align:start position:0% +so + + + align:start position:0% +so +there are pros and cons to each of these + + align:start position:0% + + + + align:start position:0% + +okay so now what we're going to do is + + align:start position:0% +okay so now what we're going to do is + + + align:start position:0% +okay so now what we're going to do is +we're actually going to train our own + + align:start position:0% +we're actually going to train our own + + + align:start position:0% +we're actually going to train our own +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +and again i wanted to reiterate the main + + align:start position:0% +and again i wanted to reiterate the main + + + align:start position:0% +and again i wanted to reiterate the main +point of this presentation before we get + + align:start position:0% +point of this presentation before we get + + + align:start position:0% +point of this presentation before we get +into that algorithm training with the + + align:start position:0% +into that algorithm training with the + + + align:start position:0% +into that algorithm training with the +right data and the right model ai can + + align:start position:0% +right data and the right model ai can + + + align:start position:0% +right data and the right model ai can +solve many problems choosing the right + + align:start position:0% +solve many problems choosing the right + + + align:start position:0% +solve many problems choosing the right +problem finding the right data training + + align:start position:0% +problem finding the right data training + + + align:start position:0% +problem finding the right data training +the right model are all potentially + + align:start position:0% +the right model are all potentially + + + align:start position:0% +the right model are all potentially +difficult + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +let's do + + align:start position:0% +let's do + + + align:start position:0% +let's do +this + + align:start position:0% +this + + + align:start position:0% +this +we're going to walk through the seven + + align:start position:0% +we're going to walk through the seven + + + align:start position:0% +we're going to walk through the seven +steps of training algorithm step one is + + align:start position:0% +steps of training algorithm step one is + + + align:start position:0% +steps of training algorithm step one is +define a problem now here i've defined + + align:start position:0% +define a problem now here i've defined + + + align:start position:0% +define a problem now here i've defined +it for us i've said we're going to + + align:start position:0% +it for us i've said we're going to + + + align:start position:0% +it for us i've said we're going to +decide whether a picture is a cat or a + + align:start position:0% +decide whether a picture is a cat or a + + + align:start position:0% +decide whether a picture is a cat or a +dog + + align:start position:0% +dog + + + align:start position:0% +dog +so first let me ask you what kind of + + align:start position:0% +so first let me ask you what kind of + + + align:start position:0% +so first let me ask you what kind of +machine learning problem is this + + align:start position:0% + + + + align:start position:0% + +answer from + + align:start position:0% +answer from + + + align:start position:0% +answer from +participant classification + + align:start position:0% +participant classification + + + align:start position:0% +participant classification +cool + + align:start position:0% +cool + + + align:start position:0% +cool +everybody see why + + align:start position:0% + + + + align:start position:0% + +i'm getting some kind of input i'm + + align:start position:0% +i'm getting some kind of input i'm + + + align:start position:0% +i'm getting some kind of input i'm +getting an image and i'm telling you + + align:start position:0% +getting an image and i'm telling you + + + align:start position:0% +getting an image and i'm telling you +what class it is what class it belongs + + align:start position:0% +what class it is what class it belongs + + + align:start position:0% +what class it is what class it belongs +to it's either a cat or a dog + + align:start position:0% + + + + align:start position:0% + +now in this case the work of problem + + align:start position:0% +now in this case the work of problem + + + align:start position:0% +now in this case the work of problem +identification has been done for us and + + align:start position:0% +identification has been done for us and + + + align:start position:0% +identification has been done for us and +we're assuming that classifying between + + align:start position:0% +we're assuming that classifying between + + + align:start position:0% +we're assuming that classifying between +cats and dogs is actually closing an + + align:start position:0% +cats and dogs is actually closing an + + + align:start position:0% +cats and dogs is actually closing an +important gap + + align:start position:0% +important gap + + + align:start position:0% +important gap +however let me just say problem + + align:start position:0% +however let me just say problem + + + align:start position:0% +however let me just say problem +identification is + + align:start position:0% +identification is + + + align:start position:0% +identification is +super important there are a lot of + + align:start position:0% +super important there are a lot of + + + align:start position:0% +super important there are a lot of +problems that cannot be solved by ai + + align:start position:0% +problems that cannot be solved by ai + + + align:start position:0% +problems that cannot be solved by ai +period + + align:start position:0% +period + + + align:start position:0% +period +right if you have issues with diversity + + align:start position:0% +right if you have issues with diversity + + + align:start position:0% +right if you have issues with diversity +in your unit + + align:start position:0% +in your unit + + + align:start position:0% +in your unit +machine learning is not the answer + + align:start position:0% +machine learning is not the answer + + + align:start position:0% +machine learning is not the answer +but + + align:start position:0% +but + + + align:start position:0% +but +as with any new technology it's really + + align:start position:0% +as with any new technology it's really + + + align:start position:0% +as with any new technology it's really +seductive it's really sexy everybody + + align:start position:0% +seductive it's really sexy everybody + + + align:start position:0% +seductive it's really sexy everybody +wants to be like oh we're using ai so i + + align:start position:0% +wants to be like oh we're using ai so i + + + align:start position:0% +wants to be like oh we're using ai so i +just want to make clear that it's + + align:start position:0% +just want to make clear that it's + + + align:start position:0% +just want to make clear that it's +important to be + + align:start position:0% +important to be + + + align:start position:0% +important to be +discerning with where you even apply ai + + align:start position:0% +discerning with where you even apply ai + + + align:start position:0% +discerning with where you even apply ai +so and that comes into that very first + + align:start position:0% +so and that comes into that very first + + + align:start position:0% +so and that comes into that very first +step of what's the problem that we're + + align:start position:0% +step of what's the problem that we're + + + align:start position:0% +step of what's the problem that we're +trying to solve + + align:start position:0% +trying to solve + + + align:start position:0% +trying to solve +define the problem + + align:start position:0% + + + + align:start position:0% + +step two + + align:start position:0% +step two + + + align:start position:0% +step two +is cool i have a problem find data + + align:start position:0% +is cool i have a problem find data + + + align:start position:0% +is cool i have a problem find data +what kind of data do i need in order to + + align:start position:0% +what kind of data do i need in order to + + + align:start position:0% +what kind of data do i need in order to +solve this problem + + align:start position:0% +solve this problem + + + align:start position:0% +solve this problem +so + + align:start position:0% +so + + + align:start position:0% +so +let's say i want to train an algorithm + + align:start position:0% +let's say i want to train an algorithm + + + align:start position:0% +let's say i want to train an algorithm +that + + align:start position:0% + + + + align:start position:0% + +can that can classify between cats and + + align:start position:0% +can that can classify between cats and + + + align:start position:0% +can that can classify between cats and +dogs what kind of data should i look at + + align:start position:0% +dogs what kind of data should i look at + + + align:start position:0% +dogs what kind of data should i look at +answer from participant + + align:start position:0% +answer from participant + + + align:start position:0% +answer from participant +it's going to be a lot of visual data + + align:start position:0% +it's going to be a lot of visual data + + + align:start position:0% +it's going to be a lot of visual data +lots of images to show cats can look all + + align:start position:0% +lots of images to show cats can look all + + + align:start position:0% +lots of images to show cats can look all +these different ways dogs can look all + + align:start position:0% +these different ways dogs can look all + + + align:start position:0% +these different ways dogs can look all +these different ways + + align:start position:0% +these different ways + + + align:start position:0% +these different ways +so something like this + + align:start position:0% +so something like this + + + align:start position:0% +so something like this +exactly + + align:start position:0% +exactly + + + align:start position:0% +exactly +now this data has labels so what kind of + + align:start position:0% +now this data has labels so what kind of + + + align:start position:0% +now this data has labels so what kind of +learning are we able to do as a result + + align:start position:0% + + + + align:start position:0% + +answer from participant + + align:start position:0% +answer from participant + + + align:start position:0% +answer from participant +supervised learning + + align:start position:0% +supervised learning + + + align:start position:0% +supervised learning +yes + + align:start position:0% + + + + align:start position:0% + +because we have the right answer in + + align:start position:0% +because we have the right answer in + + + align:start position:0% +because we have the right answer in +advance so we can train it and say ah + + align:start position:0% +advance so we can train it and say ah + + + align:start position:0% +advance so we can train it and say ah +this is a cat this is a dog now if we + + align:start position:0% +this is a cat this is a dog now if we + + + align:start position:0% +this is a cat this is a dog now if we +didn't have labels what our algorithm + + align:start position:0% +didn't have labels what our algorithm + + + align:start position:0% +didn't have labels what our algorithm +might do is cluster them together and + + align:start position:0% +might do is cluster them together and + + + align:start position:0% +might do is cluster them together and +say oh there's like this type of thing + + align:start position:0% +say oh there's like this type of thing + + + align:start position:0% +say oh there's like this type of thing +and there's this type of thing and they + + align:start position:0% +and there's this type of thing and they + + + align:start position:0% +and there's this type of thing and they +look different + + align:start position:0% +look different + + + align:start position:0% +look different +but there's no external reference and + + align:start position:0% +but there's no external reference and + + + align:start position:0% +but there's no external reference and +the thing has no idea what a cat or a + + align:start position:0% +the thing has no idea what a cat or a + + + align:start position:0% +the thing has no idea what a cat or a +dog is it's just saying these two things + + align:start position:0% +dog is it's just saying these two things + + + align:start position:0% +dog is it's just saying these two things +look different + + align:start position:0% +look different + + + align:start position:0% +look different +everybody see the difference there + + align:start position:0% +everybody see the difference there + + + align:start position:0% +everybody see the difference there +between supervised not suppressed + + align:start position:0% +between supervised not suppressed + + + align:start position:0% +between supervised not suppressed +so this one we actually can say this is + + align:start position:0% +so this one we actually can say this is + + + align:start position:0% +so this one we actually can say this is +a cat and this is a dog + + align:start position:0% +a cat and this is a dog + + + align:start position:0% +a cat and this is a dog +question from participant + + align:start position:0% +question from participant + + + align:start position:0% +question from participant +is this how google and other companies + + align:start position:0% +is this how google and other companies + + + align:start position:0% +is this how google and other companies +have been developing their technology + + align:start position:0% +have been developing their technology + + + align:start position:0% +have been developing their technology +using humans to develop data pools + + align:start position:0% +using humans to develop data pools + + + align:start position:0% +using humans to develop data pools +yeah there's i don't know if you guys if + + align:start position:0% +yeah there's i don't know if you guys if + + + align:start position:0% +yeah there's i don't know if you guys if +anybody here is familiar with xkcd it's + + align:start position:0% +anybody here is familiar with xkcd it's + + + align:start position:0% +anybody here is familiar with xkcd it's +an online web comic uh there's a one + + align:start position:0% +an online web comic uh there's a one + + + align:start position:0% +an online web comic uh there's a one +where it's like uh + + align:start position:0% +where it's like uh + + + align:start position:0% +where it's like uh +it's a it's a google + + align:start position:0% +it's a it's a google + + + align:start position:0% +it's a it's a google +sign-in thing and it's like please find + + align:start position:0% +sign-in thing and it's like please find + + + align:start position:0% +sign-in thing and it's like please find +the picture with a stop sign + + align:start position:0% +the picture with a stop sign + + + align:start position:0% +the picture with a stop sign +uh next frame please please do it + + align:start position:0% +uh next frame please please do it + + + align:start position:0% +uh next frame please please do it +quickly our car is approaching the + + align:start position:0% +quickly our car is approaching the + + + align:start position:0% +quickly our car is approaching the +intersection so yes this is absolutely + + align:start position:0% +intersection so yes this is absolutely + + + align:start position:0% +intersection so yes this is absolutely +them collecting training data by having + + align:start position:0% +them collecting training data by having + + + align:start position:0% +them collecting training data by having +humans label it + + align:start position:0% + + + + align:start position:0% + +so the next step after we found data is + + align:start position:0% +so the next step after we found data is + + + align:start position:0% +so the next step after we found data is +clean data and i know this feels like + + align:start position:0% +clean data and i know this feels like + + + align:start position:0% +clean data and i know this feels like +maybe extraneous but for anybody here + + align:start position:0% +maybe extraneous but for anybody here + + + align:start position:0% +maybe extraneous but for anybody here +who has worked with + + align:start position:0% +who has worked with + + + align:start position:0% +who has worked with +data before you get that this is a huge + + align:start position:0% +data before you get that this is a huge + + + align:start position:0% +data before you get that this is a huge +this is like 80 of data science and 80 + + align:start position:0% +this is like 80 of data science and 80 + + + align:start position:0% +this is like 80 of data science and 80 +percent of ai + + align:start position:0% +percent of ai + + + align:start position:0% +percent of ai +cleaning data is the biggest pain + + align:start position:0% +cleaning data is the biggest pain + + + align:start position:0% +cleaning data is the biggest pain +but it's most of the work right it's + + align:start position:0% +but it's most of the work right it's + + + align:start position:0% +but it's most of the work right it's +because data doesn't just exist in this + + align:start position:0% +because data doesn't just exist in this + + + align:start position:0% +because data doesn't just exist in this +like nice way where you can show it to a + + align:start position:0% +like nice way where you can show it to a + + + align:start position:0% +like nice way where you can show it to a +machine learning model and it starts + + align:start position:0% +machine learning model and it starts + + + align:start position:0% +machine learning model and it starts +learning like data exists in some weird + + align:start position:0% +learning like data exists in some weird + + + align:start position:0% +learning like data exists in some weird +directory on the internet where you have + + align:start position:0% +directory on the internet where you have + + + align:start position:0% +directory on the internet where you have +to download it you have to reorganize it + + align:start position:0% +to download it you have to reorganize it + + + align:start position:0% +to download it you have to reorganize it +you have to name it properly you have to + + align:start position:0% +you have to name it properly you have to + + + align:start position:0% +you have to name it properly you have to +make sure that there are no errors there + + align:start position:0% +make sure that there are no errors there + + + align:start position:0% +make sure that there are no errors there +you have to make sure that you can + + align:start position:0% +you have to make sure that you can + + + align:start position:0% +you have to make sure that you can +access it quickly blah blah blah + + align:start position:0% +access it quickly blah blah blah + + + align:start position:0% +access it quickly blah blah blah +so cleaning data is a huge part of what + + align:start position:0% +so cleaning data is a huge part of what + + + align:start position:0% +so cleaning data is a huge part of what +it means to + + align:start position:0% +it means to + + + align:start position:0% +it means to +be a data scientist and to do machine + + align:start position:0% +be a data scientist and to do machine + + + align:start position:0% +be a data scientist and to do machine +learning in order to do ai + + align:start position:0% +learning in order to do ai + + + align:start position:0% +learning in order to do ai +and that's why + + align:start position:0% +and that's why + + + align:start position:0% +and that's why +if you have already clean data oh my god + + align:start position:0% +if you have already clean data oh my god + + + align:start position:0% +if you have already clean data oh my god +it's like a data scientist paradise + + align:start position:0% +it's like a data scientist paradise + + + align:start position:0% +it's like a data scientist paradise +because they don't have to do that work + + align:start position:0% +because they don't have to do that work + + + align:start position:0% +because they don't have to do that work +they can just go and download stuff and + + align:start position:0% +they can just go and download stuff and + + + align:start position:0% +they can just go and download stuff and +train models and that's the fun part + + align:start position:0% + + + + align:start position:0% + +so getting good clean data is a huge + + align:start position:0% +so getting good clean data is a huge + + + align:start position:0% +so getting good clean data is a huge +boon for any kind of ai development for + + align:start position:0% +boon for any kind of ai development for + + + align:start position:0% +boon for any kind of ai development for +us we're going to say that this is now + + align:start position:0% +us we're going to say that this is now + + + align:start position:0% +us we're going to say that this is now +clean + + align:start position:0% + + + + align:start position:0% + +step four is choose a model + + align:start position:0% +step four is choose a model + + + align:start position:0% +step four is choose a model +i'm gonna show you guys a model now + + align:start position:0% +i'm gonna show you guys a model now + + + align:start position:0% +i'm gonna show you guys a model now +don't get attached to this model + + align:start position:0% +don't get attached to this model + + + align:start position:0% +don't get attached to this model +it's not a good model it's not a helpful + + align:start position:0% +it's not a good model it's not a helpful + + + align:start position:0% +it's not a good model it's not a helpful +model in the real world it's a model + + align:start position:0% +model in the real world it's a model + + + align:start position:0% +model in the real world it's a model +that we're gonna use to illustrate a few + + align:start position:0% +that we're gonna use to illustrate a few + + + align:start position:0% +that we're gonna use to illustrate a few +key concepts + + align:start position:0% +key concepts + + + align:start position:0% +key concepts +so this is our model + + align:start position:0% +so this is our model + + + align:start position:0% +so this is our model +dogs always blank sometimes blank cats + + align:start position:0% +dogs always blank sometimes blank cats + + + align:start position:0% +dogs always blank sometimes blank cats +always + + align:start position:0% +always + + + align:start position:0% +always +sometimes + + align:start position:0% + + + + align:start position:0% + +this model is interpretable + + align:start position:0% +this model is interpretable + + + align:start position:0% +this model is interpretable +which means that it may not be good + + align:start position:0% +which means that it may not be good + + + align:start position:0% +which means that it may not be good +we'll find but at the very least we'll + + align:start position:0% +we'll find but at the very least we'll + + + align:start position:0% +we'll find but at the very least we'll +be able to know what it's doing it's not + + align:start position:0% +be able to know what it's doing it's not + + + align:start position:0% +be able to know what it's doing it's not +going to always be true + + align:start position:0% +going to always be true + + + align:start position:0% +going to always be true +but this is the model we're going to use + + align:start position:0% + + + + align:start position:0% + +so now let's train it let's see what it + + align:start position:0% +so now let's train it let's see what it + + + align:start position:0% +so now let's train it let's see what it +means for a model to learn something + + align:start position:0% +means for a model to learn something + + + align:start position:0% +means for a model to learn something +we're going to show the model inputs and + + align:start position:0% +we're going to show the model inputs and + + + align:start position:0% +we're going to show the model inputs and +we're going to ask it + + align:start position:0% +we're going to ask it + + + align:start position:0% +we're going to ask it +what is this thing + + align:start position:0% +what is this thing + + + align:start position:0% +what is this thing +if it answers them correctly + + align:start position:0% +if it answers them correctly + + + align:start position:0% +if it answers them correctly +the model's great doesn't need to be + + align:start position:0% +the model's great doesn't need to be + + + align:start position:0% +the model's great doesn't need to be +updated if it gets it wrong maybe we can + + align:start position:0% +updated if it gets it wrong maybe we can + + + align:start position:0% +updated if it gets it wrong maybe we can +improve the model somehow so at the at + + align:start position:0% +improve the model somehow so at the at + + + align:start position:0% +improve the model somehow so at the at +the very beginning + + align:start position:0% +the very beginning + + + align:start position:0% +the very beginning +we're gonna show this picture + + align:start position:0% +we're gonna show this picture + + + align:start position:0% +we're gonna show this picture +now + + align:start position:0% +now + + + align:start position:0% +now +the model has never seen anything at + + align:start position:0% +the model has never seen anything at + + + align:start position:0% +the model has never seen anything at +this point it's a totally blank slate + + align:start position:0% +this point it's a totally blank slate + + + align:start position:0% +this point it's a totally blank slate +it's just gonna make a random guess + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +obviously this is a cap we know that + + align:start position:0% +obviously this is a cap we know that + + + align:start position:0% +obviously this is a cap we know that +if the model guessed correctly there + + align:start position:0% +if the model guessed correctly there + + + align:start position:0% +if the model guessed correctly there +would be no update to the model as far + + align:start position:0% +would be no update to the model as far + + + align:start position:0% +would be no update to the model as far +as the model is concerned i'm 100 + + align:start position:0% +as the model is concerned i'm 100 + + + align:start position:0% +as the model is concerned i'm 100 +accurate + + align:start position:0% +accurate + + + align:start position:0% +accurate +why would i change + + align:start position:0% + + + + align:start position:0% + +well let's say that the model gets it + + align:start position:0% +well let's say that the model gets it + + + align:start position:0% +well let's say that the model gets it +wrong let's say the model guessed dog + + align:start position:0% +wrong let's say the model guessed dog + + + align:start position:0% +wrong let's say the model guessed dog +in that case we would go ahead and + + align:start position:0% +in that case we would go ahead and + + + align:start position:0% +in that case we would go ahead and +update the model + + align:start position:0% +update the model + + + align:start position:0% +update the model +so again we have + + align:start position:0% +so again we have + + + align:start position:0% +so again we have +model now knows that the cat is going to + + align:start position:0% +model now knows that the cat is going to + + + align:start position:0% +model now knows that the cat is going to +update itself so what should the model + + align:start position:0% +update itself so what should the model + + + align:start position:0% +update itself so what should the model +now say about cats what is the mod based + + align:start position:0% +now say about cats what is the mod based + + + align:start position:0% +now say about cats what is the mod based +on this example what does the model now + + align:start position:0% +on this example what does the model now + + + align:start position:0% +on this example what does the model now +know about cats + + align:start position:0% +know about cats + + + align:start position:0% +know about cats +answers from participants + + align:start position:0% +answers from participants + + + align:start position:0% +answers from participants +are you looking for things like pointy + + align:start position:0% +are you looking for things like pointy + + + align:start position:0% +are you looking for things like pointy +ears pink nose round eyes + + align:start position:0% +ears pink nose round eyes + + + align:start position:0% +ears pink nose round eyes +i feel like there's not even enough data + + align:start position:0% +i feel like there's not even enough data + + + align:start position:0% +i feel like there's not even enough data +to say that yet + + align:start position:0% +to say that yet + + + align:start position:0% +to say that yet +with such a small training set all the + + align:start position:0% +with such a small training set all the + + + align:start position:0% +with such a small training set all the +model knows is that a cat looks like + + align:start position:0% +model knows is that a cat looks like + + + align:start position:0% +model knows is that a cat looks like +that + + align:start position:0% +that + + + align:start position:0% +that +ah okay so let me ask so + + align:start position:0% +ah okay so let me ask so + + + align:start position:0% +ah okay so let me ask so +good + + align:start position:0% +good + + + align:start position:0% +good +good intuition + + align:start position:0% +good intuition + + + align:start position:0% +good intuition +so we heard pointy ears uh multi-colored + + align:start position:0% +so we heard pointy ears uh multi-colored + + + align:start position:0% +so we heard pointy ears uh multi-colored +laying out of bed maybe uh + + align:start position:0% +laying out of bed maybe uh + + + align:start position:0% +laying out of bed maybe uh +uh pause + + align:start position:0% +uh pause + + + align:start position:0% +uh pause +in our model + + align:start position:0% +in our model + + + align:start position:0% +in our model +when we update it are we gonna say + + align:start position:0% +when we update it are we gonna say + + + align:start position:0% +when we update it are we gonna say +always have those things cats always + + align:start position:0% +always have those things cats always + + + align:start position:0% +always have those things cats always +have those things or cats sometimes have + + align:start position:0% +have those things or cats sometimes have + + + align:start position:0% +have those things or cats sometimes have +those things the cats always have pointy + + align:start position:0% +those things the cats always have pointy + + + align:start position:0% +those things the cats always have pointy +ears and are on a bed and + + align:start position:0% +ears and are on a bed and + + + align:start position:0% +ears and are on a bed and +have a pink nose or is it sometimes what + + align:start position:0% +have a pink nose or is it sometimes what + + + align:start position:0% +have a pink nose or is it sometimes what +do we think + + align:start position:0% +do we think + + + align:start position:0% +do we think +answer from participant + + align:start position:0% +answer from participant + + + align:start position:0% +answer from participant +sometimes + + align:start position:0% +sometimes + + + align:start position:0% +sometimes +definitely + + align:start position:0% +definitely + + + align:start position:0% +definitely +okay any any different opinions + + align:start position:0% + + + + align:start position:0% + +so here's the thing corey knows what + + align:start position:0% +so here's the thing corey knows what + + + align:start position:0% +so here's the thing corey knows what +cats are + + align:start position:0% +cats are + + + align:start position:0% +cats are +our model is dumb our model knows + + align:start position:0% +our model is dumb our model knows + + + align:start position:0% +our model is dumb our model knows +nothing about the world it knows nothing + + align:start position:0% +nothing about the world it knows nothing + + + align:start position:0% +nothing about the world it knows nothing +about cats + + align:start position:0% +about cats + + + align:start position:0% +about cats +as far as the model is concerned + + align:start position:0% +as far as the model is concerned + + + align:start position:0% +as far as the model is concerned +as uh somebody else just mentioned + + align:start position:0% +as uh somebody else just mentioned + + + align:start position:0% +as uh somebody else just mentioned +this is the only cat in the world this + + align:start position:0% +this is the only cat in the world this + + + align:start position:0% +this is the only cat in the world this +is what this is what every cat looks + + align:start position:0% +is what this is what every cat looks + + + align:start position:0% +is what this is what every cat looks +like every cat is is this cat and this + + align:start position:0% +like every cat is is this cat and this + + + align:start position:0% +like every cat is is this cat and this +cat is every cat + + align:start position:0% + + + + align:start position:0% + +so from the model's perspective cats + + align:start position:0% +so from the model's perspective cats + + + align:start position:0% +so from the model's perspective cats +always look exactly like this thing + + align:start position:0% +always look exactly like this thing + + + align:start position:0% +always look exactly like this thing +it's the only example it's ever seen a + + align:start position:0% +it's the only example it's ever seen a + + + align:start position:0% +it's the only example it's ever seen a +cat what do you want + + align:start position:0% +cat what do you want + + + align:start position:0% +cat what do you want +that's what cats look like + + align:start position:0% + + + + align:start position:0% + +so the model is purely statistical it + + align:start position:0% +so the model is purely statistical it + + + align:start position:0% +so the model is purely statistical it +has no idea what a cat is conceptually + + align:start position:0% +has no idea what a cat is conceptually + + + align:start position:0% +has no idea what a cat is conceptually +it just says statistically speaking 100 + + align:start position:0% +it just says statistically speaking 100 + + + align:start position:0% +it just says statistically speaking 100 +of cats look exactly like this + + align:start position:0% +of cats look exactly like this + + + align:start position:0% +of cats look exactly like this +now we show it a second + + align:start position:0% +now we show it a second + + + align:start position:0% +now we show it a second +input example + + align:start position:0% + + + + align:start position:0% + +okay now at this point our model is + + align:start position:0% +okay now at this point our model is + + + align:start position:0% +okay now at this point our model is +looking at this image it's saying well + + align:start position:0% + + + + align:start position:0% + +all the cats + + align:start position:0% +all the cats + + + align:start position:0% +all the cats +that i've seen look like that other cat + + align:start position:0% +that i've seen look like that other cat + + + align:start position:0% +that i've seen look like that other cat +and this does not look like that other + + align:start position:0% +and this does not look like that other + + + align:start position:0% +and this does not look like that other +cat so this must be a dog i haven't seen + + align:start position:0% +cat so this must be a dog i haven't seen + + + align:start position:0% +cat so this must be a dog i haven't seen +a dog yet it was probably a dog + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +turns out model's wrong + + align:start position:0% +turns out model's wrong + + + align:start position:0% +turns out model's wrong +model has to get updated + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +at this point + + align:start position:0% +at this point + + + align:start position:0% +at this point +what is our model gonna so tell me about + + align:start position:0% +what is our model gonna so tell me about + + + align:start position:0% +what is our model gonna so tell me about +this cat what is what is the model gonna + + align:start position:0% +this cat what is what is the model gonna + + + align:start position:0% +this cat what is what is the model gonna +know about cats after this example + + align:start position:0% + + + + align:start position:0% + +answers from participants + + align:start position:0% +answers from participants + + + align:start position:0% +answers from participants +they're mean + + align:start position:0% +they're mean + + + align:start position:0% +they're mean +looking cats can be super fluffy and + + align:start position:0% +looking cats can be super fluffy and + + + align:start position:0% +looking cats can be super fluffy and +have yellow eyes + + align:start position:0% +have yellow eyes + + + align:start position:0% +have yellow eyes +their pupils can be small or big + + align:start position:0% +their pupils can be small or big + + + align:start position:0% +their pupils can be small or big +good okay so now let me ask + + align:start position:0% +good okay so now let me ask + + + align:start position:0% +good okay so now let me ask +are we going to put this in sometimes or + + align:start position:0% +are we going to put this in sometimes or + + + align:start position:0% +are we going to put this in sometimes or +always + + align:start position:0% +always + + + align:start position:0% +always +these examples we just got answer from + + align:start position:0% +these examples we just got answer from + + + align:start position:0% +these examples we just got answer from +participant + + align:start position:0% +participant + + + align:start position:0% +participant +sometimes + + align:start position:0% +sometimes + + + align:start position:0% +sometimes +some of them are going to be sometimes + + align:start position:0% +some of them are going to be sometimes + + + align:start position:0% +some of them are going to be sometimes +right so cats still have two eyes always + + align:start position:0% +right so cats still have two eyes always + + + align:start position:0% +right so cats still have two eyes always +so far right all cats have two eyes all + + align:start position:0% +so far right all cats have two eyes all + + + align:start position:0% +so far right all cats have two eyes all +cats have a nose that looks roughly like + + align:start position:0% +cats have a nose that looks roughly like + + + align:start position:0% +cats have a nose that looks roughly like +this + + align:start position:0% +this + + + align:start position:0% +this +sometimes it's a big nose sometimes it's + + align:start position:0% +sometimes it's a big nose sometimes it's + + + align:start position:0% +sometimes it's a big nose sometimes it's +the black nose right so now where we are + + align:start position:0% +the black nose right so now where we are + + + align:start position:0% +the black nose right so now where we are +flushing out our model a little bit more + + align:start position:0% +flushing out our model a little bit more + + + align:start position:0% +flushing out our model a little bit more +and we're seeing oh like + + align:start position:0% +and we're seeing oh like + + + align:start position:0% +and we're seeing oh like +these are things that cats always have + + align:start position:0% +these are things that cats always have + + + align:start position:0% +these are things that cats always have +and these are things that counts + + align:start position:0% +and these are things that counts + + + align:start position:0% +and these are things that counts +sometimes now + + align:start position:0% +sometimes now + + + align:start position:0% +sometimes now +does this make sense + + align:start position:0% +does this make sense + + + align:start position:0% +does this make sense +okay + + align:start position:0% + + + + align:start position:0% + +all the things that we just wrote down + + align:start position:0% +all the things that we just wrote down + + + align:start position:0% +all the things that we just wrote down +are called features + + align:start position:0% + + + + align:start position:0% + +the number of eyes + + align:start position:0% +the number of eyes + + + align:start position:0% +the number of eyes +the shape of the + + align:start position:0% +the shape of the + + + align:start position:0% +the shape of the +ears the size of the pupils these are + + align:start position:0% +ears the size of the pupils these are + + + align:start position:0% +ears the size of the pupils these are +all features + + align:start position:0% +all features + + + align:start position:0% +all features +features are + + align:start position:0% +features are + + + align:start position:0% +features are +what allow us + + align:start position:0% +what allow us + + + align:start position:0% +what allow us +or allow the model rather to make the + + align:start position:0% +or allow the model rather to make the + + + align:start position:0% +or allow the model rather to make the +decision + + align:start position:0% + + + + align:start position:0% + +so for example if i am looking + + align:start position:0% +so for example if i am looking + + + align:start position:0% +so for example if i am looking +i'm just walking around + + align:start position:0% +i'm just walking around + + + align:start position:0% +i'm just walking around +trying to you know assess safety which + + align:start position:0% +trying to you know assess safety which + + + align:start position:0% +trying to you know assess safety which +is i think a thing that people kind of + + align:start position:0% +is i think a thing that people kind of + + + align:start position:0% +is i think a thing that people kind of +do instinctually there are features that + + align:start position:0% +do instinctually there are features that + + + align:start position:0% +do instinctually there are features that +i'm looking for right like uh + + align:start position:0% +i'm looking for right like uh + + + align:start position:0% +i'm looking for right like uh +is + + align:start position:0% +is + + + align:start position:0% +is +is the person that's approached to me + + align:start position:0% +is the person that's approached to me + + + align:start position:0% +is the person that's approached to me +holding any weapons um what's their + + align:start position:0% +holding any weapons um what's their + + + align:start position:0% +holding any weapons um what's their +posture like what what are they what's + + align:start position:0% +posture like what what are they what's + + + align:start position:0% +posture like what what are they what's +their facial expression like like right + + align:start position:0% +their facial expression like like right + + + align:start position:0% +their facial expression like like right +i'm not looking at um + + align:start position:0% + + + + align:start position:0% + +the color of their hair + + align:start position:0% +the color of their hair + + + align:start position:0% +the color of their hair +like that's not a relevant feature in + + align:start position:0% +like that's not a relevant feature in + + + align:start position:0% +like that's not a relevant feature in +that particular example + + align:start position:0% +that particular example + + + align:start position:0% +that particular example +so in this case all of all the things + + align:start position:0% +so in this case all of all the things + + + align:start position:0% +so in this case all of all the things +that we're pulling out to say to + + align:start position:0% +that we're pulling out to say to + + + align:start position:0% +that we're pulling out to say to +identify this is a cat or a dog + + align:start position:0% +identify this is a cat or a dog + + + align:start position:0% +identify this is a cat or a dog +those are + + align:start position:0% +those are + + + align:start position:0% +those are +what we call features + + align:start position:0% +what we call features + + + align:start position:0% +what we call features +now let me ask you a somewhat tricky + + align:start position:0% +now let me ask you a somewhat tricky + + + align:start position:0% +now let me ask you a somewhat tricky +question + + align:start position:0% +question + + + align:start position:0% +question +when a computer sees an image + + align:start position:0% +when a computer sees an image + + + align:start position:0% +when a computer sees an image +let's say it's a 256 by 256 pixel image + + align:start position:0% +let's say it's a 256 by 256 pixel image + + + align:start position:0% +let's say it's a 256 by 256 pixel image +how many features does the computer see + + align:start position:0% + + + + align:start position:0% + +answer from participant + + align:start position:0% +answer from participant + + + align:start position:0% +answer from participant +is it 256 because that's how many pixels + + align:start position:0% +is it 256 because that's how many pixels + + + align:start position:0% +is it 256 because that's how many pixels +there are + + align:start position:0% +there are + + + align:start position:0% +there are +so it's 256 squared + + align:start position:0% +so it's 256 squared + + + align:start position:0% +so it's 256 squared +pixels and that's how many features + + align:start position:0% +pixels and that's how many features + + + align:start position:0% +pixels and that's how many features +there are the computer is looking at it + + align:start position:0% +there are the computer is looking at it + + + align:start position:0% +there are the computer is looking at it +it's not looking at eyes it's not + + align:start position:0% +it's not looking at eyes it's not + + + align:start position:0% +it's not looking at eyes it's not +looking at ears it's not looking at nose + + align:start position:0% +looking at ears it's not looking at nose + + + align:start position:0% +looking at ears it's not looking at nose +it's looking at there's a pixel here + + align:start position:0% +it's looking at there's a pixel here + + + align:start position:0% +it's looking at there's a pixel here +and there's + + align:start position:0% +and there's + + + align:start position:0% +and there's +a whole bunch more + + align:start position:0% +a whole bunch more + + + align:start position:0% +a whole bunch more +throughout the rest of the image it's + + align:start position:0% +throughout the rest of the image it's + + + align:start position:0% +throughout the rest of the image it's +looking at an array of data + + align:start position:0% + + + + align:start position:0% + +now what a neural network does and what + + align:start position:0% +now what a neural network does and what + + + align:start position:0% +now what a neural network does and what +a convolutional neural network does in + + align:start position:0% +a convolutional neural network does in + + + align:start position:0% +a convolutional neural network does in +particular + + align:start position:0% +particular + + + align:start position:0% +particular +is + + align:start position:0% + + + + align:start position:0% + +the image gets passed so whoever asks + + align:start position:0% +the image gets passed so whoever asks + + + align:start position:0% +the image gets passed so whoever asks +about convolutional neural networks if + + align:start position:0% +about convolutional neural networks if + + + align:start position:0% +about convolutional neural networks if +you are paying attention + + align:start position:0% +you are paying attention + + + align:start position:0% +you are paying attention +that was a good + + align:start position:0% +that was a good + + + align:start position:0% +that was a good +chance to tune in + + align:start position:0% +chance to tune in + + + align:start position:0% +chance to tune in +what a neural network does a + + align:start position:0% +what a neural network does a + + + align:start position:0% +what a neural network does a +convolutional neural network takes an + + align:start position:0% +convolutional neural network takes an + + + align:start position:0% +convolutional neural network takes an +image says 256 by 256 pixels + + align:start position:0% +image says 256 by 256 pixels + + + align:start position:0% +image says 256 by 256 pixels +passes it through the first layer of the + + align:start position:0% +passes it through the first layer of the + + + align:start position:0% +passes it through the first layer of the +neural network + + align:start position:0% +neural network + + + align:start position:0% +neural network +it starts extracting features with that + + align:start position:0% +it starts extracting features with that + + + align:start position:0% +it starts extracting features with that +first layer maybe it's looking at lines + + align:start position:0% +first layer maybe it's looking at lines + + + align:start position:0% +first layer maybe it's looking at lines +or edges or color gradients + + align:start position:0% +or edges or color gradients + + + align:start position:0% +or edges or color gradients +passes it through the next + + align:start position:0% +passes it through the next + + + align:start position:0% +passes it through the next +layer in the neural network + + align:start position:0% +layer in the neural network + + + align:start position:0% +layer in the neural network +and it + + align:start position:0% +and it + + + align:start position:0% +and it +combines those lines into shapes maybe + + align:start position:0% +combines those lines into shapes maybe + + + align:start position:0% +combines those lines into shapes maybe +now it's looking for circles or + + align:start position:0% +now it's looking for circles or + + + align:start position:0% +now it's looking for circles or +triangles or or whatever + + align:start position:0% +triangles or or whatever + + + align:start position:0% +triangles or or whatever +next + + align:start position:0% +next + + + align:start position:0% +next +part of the neural network you have to + + align:start position:0% +part of the neural network you have to + + + align:start position:0% +part of the neural network you have to +pass through again so it's processing it + + align:start position:0% +pass through again so it's processing it + + + align:start position:0% +pass through again so it's processing it +processing it making it more like making + + align:start position:0% +processing it making it more like making + + + align:start position:0% +processing it making it more like making +the features automatically extracting + + align:start position:0% +the features automatically extracting + + + align:start position:0% +the features automatically extracting +features at each step and making the + + align:start position:0% +features at each step and making the + + + align:start position:0% +features at each step and making the +features more and more sophisticated so + + align:start position:0% +features more and more sophisticated so + + + align:start position:0% +features more and more sophisticated so +now it's looking at noses and eyes and + + align:start position:0% +now it's looking at noses and eyes and + + + align:start position:0% +now it's looking at noses and eyes and +now finally at the very end it's looking + + align:start position:0% +now finally at the very end it's looking + + + align:start position:0% +now finally at the very end it's looking +at a whole face + + align:start position:0% +at a whole face + + + align:start position:0% +at a whole face +or a whole body + + align:start position:0% + + + + align:start position:0% + +so that's what a convolutional neural + + align:start position:0% +so that's what a convolutional neural + + + align:start position:0% +so that's what a convolutional neural +network does + + align:start position:0% +network does + + + align:start position:0% +network does +but it starts with a model's perspective + + align:start position:0% +but it starts with a model's perspective + + + align:start position:0% +but it starts with a model's perspective +as + + align:start position:0% +as + + + align:start position:0% +as +256 by 256 features and what a neural + + align:start position:0% +256 by 256 features and what a neural + + + align:start position:0% +256 by 256 features and what a neural +network is sometimes really really good + + align:start position:0% +network is sometimes really really good + + + align:start position:0% +network is sometimes really really good +at is extracting the features that are + + align:start position:0% +at is extracting the features that are + + + align:start position:0% +at is extracting the features that are +relevant combining them and processing + + align:start position:0% +relevant combining them and processing + + + align:start position:0% +relevant combining them and processing +them into their until they're more and + + align:start position:0% +them into their until they're more and + + + align:start position:0% +them into their until they're more and +more sophisticated and now you have + + align:start position:0% +more sophisticated and now you have + + + align:start position:0% +more sophisticated and now you have +facial recognition for example right + + align:start position:0% +facial recognition for example right + + + align:start position:0% +facial recognition for example right +it's there's like some kind of uh eye + + align:start position:0% +it's there's like some kind of uh eye + + + align:start position:0% +it's there's like some kind of uh eye +nose mouth structure that i'm looking + + align:start position:0% +nose mouth structure that i'm looking + + + align:start position:0% +nose mouth structure that i'm looking +for oh like this is your face i know who + + align:start position:0% +for oh like this is your face i know who + + + align:start position:0% +for oh like this is your face i know who +this is + + align:start position:0% +this is + + + align:start position:0% +this is +so that's what a convolutional neural + + align:start position:0% +so that's what a convolutional neural + + + align:start position:0% +so that's what a convolutional neural +network does but i just wanted to be + + align:start position:0% +network does but i just wanted to be + + + align:start position:0% +network does but i just wanted to be +clear again + + align:start position:0% +clear again + + + align:start position:0% +clear again +models are dumb + + align:start position:0% +models are dumb + + + align:start position:0% +models are dumb +they're not looking at this from the + + align:start position:0% +they're not looking at this from the + + + align:start position:0% +they're not looking at this from the +perspective of i know what a nose or a + + align:start position:0% +perspective of i know what a nose or a + + + align:start position:0% +perspective of i know what a nose or a +cat or a dog is + + align:start position:0% +cat or a dog is + + + align:start position:0% +cat or a dog is +they're looking at it from the + + align:start position:0% +they're looking at it from the + + + align:start position:0% +they're looking at it from the +perspective of i see an array of data + + align:start position:0% + + + + align:start position:0% + +and sometimes a neural network a model + + align:start position:0% +and sometimes a neural network a model + + + align:start position:0% +and sometimes a neural network a model +can interpret it and create these + + align:start position:0% +can interpret it and create these + + + align:start position:0% +can interpret it and create these +features that are more sophisticated + + align:start position:0% +features that are more sophisticated + + + align:start position:0% +features that are more sophisticated +i'll also say these models can be very + + align:start position:0% +i'll also say these models can be very + + + align:start position:0% +i'll also say these models can be very +brittle so there was a paper written a + + align:start position:0% +brittle so there was a paper written a + + + align:start position:0% +brittle so there was a paper written a +few years ago where + + align:start position:0% +few years ago where + + + align:start position:0% +few years ago where +they basically tricked the neural + + align:start position:0% +they basically tricked the neural + + + align:start position:0% +they basically tricked the neural +network and by changing just a few + + align:start position:0% +network and by changing just a few + + + align:start position:0% +network and by changing just a few +pixels or adding some noise + + align:start position:0% +pixels or adding some noise + + + align:start position:0% +pixels or adding some noise +it still looks like a turtle to humans + + align:start position:0% +it still looks like a turtle to humans + + + align:start position:0% +it still looks like a turtle to humans +we still say it's a turtle but the model + + align:start position:0% +we still say it's a turtle but the model + + + align:start position:0% +we still say it's a turtle but the model +looks at it and says oh this is a gun or + + align:start position:0% +looks at it and says oh this is a gun or + + + align:start position:0% +looks at it and says oh this is a gun or +oh this is a rooster + + align:start position:0% + + + + align:start position:0% + +and they could change anything into + + align:start position:0% +and they could change anything into + + + align:start position:0% +and they could change anything into +anything as far as the model was + + align:start position:0% +anything as far as the model was + + + align:start position:0% +anything as far as the model was +concerned + + align:start position:0% +concerned + + + align:start position:0% +concerned +then you can train your model on that + + align:start position:0% +then you can train your model on that + + + align:start position:0% +then you can train your model on that +data and you can make the model more + + align:start position:0% +data and you can make the model more + + + align:start position:0% +data and you can make the model more +robust to it so you end up with this + + align:start position:0% +robust to it so you end up with this + + + align:start position:0% +robust to it so you end up with this +kind of adversarial play uh similar to + + align:start position:0% +kind of adversarial play uh similar to + + + align:start position:0% +kind of adversarial play uh similar to +other defensive + + align:start position:0% + + + + align:start position:0% + +operations i assume + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% +but + + + align:start position:0% +but +at any rate that's a bit of a tangent + + align:start position:0% +at any rate that's a bit of a tangent + + + align:start position:0% +at any rate that's a bit of a tangent +any questions so far on training we're + + align:start position:0% +any questions so far on training we're + + + align:start position:0% +any questions so far on training we're +gonna we're gonna do a dog example + + align:start position:0% +gonna we're gonna do a dog example + + + align:start position:0% +gonna we're gonna do a dog example +really quick + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +next example this thing + + align:start position:0% +next example this thing + + + align:start position:0% +next example this thing +so again we're going to assume the model + + align:start position:0% +so again we're going to assume the model + + + align:start position:0% +so again we're going to assume the model +gets it wrong so there's an update + + align:start position:0% +gets it wrong so there's an update + + + align:start position:0% +gets it wrong so there's an update +we're going to describe this dog it's + + align:start position:0% +we're going to describe this dog it's + + + align:start position:0% +we're going to describe this dog it's +black it's got floppy ears it's got + + align:start position:0% +black it's got floppy ears it's got + + + align:start position:0% +black it's got floppy ears it's got +brown eyes it's got a pink tongue four + + align:start position:0% +brown eyes it's got a pink tongue four + + + align:start position:0% +brown eyes it's got a pink tongue four +legs where is this going always or + + align:start position:0% +legs where is this going always or + + + align:start position:0% +legs where is this going always or +sometimes + + align:start position:0% + + + + align:start position:0% + +what do you think + + align:start position:0% + + + + align:start position:0% + +always this is the only dog that exists + + align:start position:0% +always this is the only dog that exists + + + align:start position:0% +always this is the only dog that exists +in the whole world this is what every + + align:start position:0% +in the whole world this is what every + + + align:start position:0% +in the whole world this is what every +dog looks like every dog is this dog + + align:start position:0% + + + + align:start position:0% + +now when we see + + align:start position:0% +now when we see + + + align:start position:0% +now when we see +oh yeah sorry dog uh as we know now when + + align:start position:0% +oh yeah sorry dog uh as we know now when + + + align:start position:0% +oh yeah sorry dog uh as we know now when +we see this guy the model is going to + + align:start position:0% +we see this guy the model is going to + + + align:start position:0% +we see this guy the model is going to +update and now we have that change right + + align:start position:0% +update and now we have that change right + + + align:start position:0% +update and now we have that change right +where it's okay there's two eyes + + align:start position:0% +where it's okay there's two eyes + + + align:start position:0% +where it's okay there's two eyes +still so every dog has two you know + + align:start position:0% +still so every dog has two you know + + + align:start position:0% +still so every dog has two you know +until we see a dog with only one eye + + align:start position:0% +until we see a dog with only one eye + + + align:start position:0% +until we see a dog with only one eye +and now the mom's like okay well it + + align:start position:0% +and now the mom's like okay well it + + + align:start position:0% +and now the mom's like okay well it +looks like most of the time dogs have + + align:start position:0% +looks like most of the time dogs have + + + align:start position:0% +looks like most of the time dogs have +two eyes and sometimes they have one + + align:start position:0% +two eyes and sometimes they have one + + + align:start position:0% +two eyes and sometimes they have one +um yeah statistical model + + align:start position:0% +um yeah statistical model + + + align:start position:0% +um yeah statistical model +but at this point + + align:start position:0% +but at this point + + + align:start position:0% +but at this point +100 of dogs look exactly like this dog + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +that's how we train a model we now have + + align:start position:0% +that's how we train a model we now have + + + align:start position:0% +that's how we train a model we now have +a model + + align:start position:0% +a model + + + align:start position:0% +a model +of what cats and dogs look like or do or + + align:start position:0% +of what cats and dogs look like or do or + + + align:start position:0% +of what cats and dogs look like or do or +are + + align:start position:0% +are + + + align:start position:0% +are +so now we go and we test the model and + + align:start position:0% +so now we go and we test the model and + + + align:start position:0% +so now we go and we test the model and +it's really really critical when we test + + align:start position:0% +it's really really critical when we test + + + align:start position:0% +it's really really critical when we test +the model we use data + + align:start position:0% +the model we use data + + + align:start position:0% +the model we use data +but the model has not seen before + + align:start position:0% +but the model has not seen before + + + align:start position:0% +but the model has not seen before +if i give you + + align:start position:0% +if i give you + + + align:start position:0% +if i give you +the exam in + + align:start position:0% +the exam in + + + align:start position:0% +the exam in +advance then you can just memorize the + + align:start position:0% +advance then you can just memorize the + + + align:start position:0% +advance then you can just memorize the +questions + + align:start position:0% +questions + + + align:start position:0% +questions +and the answers that's not really + + align:start position:0% +and the answers that's not really + + + align:start position:0% +and the answers that's not really +helpful for me to determine whether + + align:start position:0% +helpful for me to determine whether + + + align:start position:0% +helpful for me to determine whether +you've actually learned the material + + align:start position:0% +you've actually learned the material + + + align:start position:0% +you've actually learned the material +right i want to give you some sample + + align:start position:0% +right i want to give you some sample + + + align:start position:0% +right i want to give you some sample +questions sample answers and then on the + + align:start position:0% +questions sample answers and then on the + + + align:start position:0% +questions sample answers and then on the +test i'll give you different ones + + align:start position:0% +test i'll give you different ones + + + align:start position:0% +test i'll give you different ones +because i want to make sure that you can + + align:start position:0% +because i want to make sure that you can + + + align:start position:0% +because i want to make sure that you can +generalize to other problems to other + + align:start position:0% +generalize to other problems to other + + + align:start position:0% +generalize to other problems to other +kinds of questions if you just memorize + + align:start position:0% +kinds of questions if you just memorize + + + align:start position:0% +kinds of questions if you just memorize +the solutions it's not helpful for me to + + align:start position:0% +the solutions it's not helpful for me to + + + align:start position:0% +the solutions it's not helpful for me to +understand whether you've learned it so + + align:start position:0% +understand whether you've learned it so + + + align:start position:0% +understand whether you've learned it so +when you're testing the model it is + + align:start position:0% +when you're testing the model it is + + + align:start position:0% +when you're testing the model it is +absolutely critical that you're using + + align:start position:0% +absolutely critical that you're using + + + align:start position:0% +absolutely critical that you're using +data that the model has not yet seen + + align:start position:0% +data that the model has not yet seen + + + align:start position:0% +data that the model has not yet seen +now in this case what we're finding is + + align:start position:0% +now in this case what we're finding is + + + align:start position:0% +now in this case what we're finding is +this thing is black + + align:start position:0% +this thing is black + + + align:start position:0% +this thing is black +it has two eyes it doesn't have pointy + + align:start position:0% +it has two eyes it doesn't have pointy + + + align:start position:0% +it has two eyes it doesn't have pointy +ears but the thing is black and our + + align:start position:0% +ears but the thing is black and our + + + align:start position:0% +ears but the thing is black and our +model has never seen a black cat before + + align:start position:0% +model has never seen a black cat before + + + align:start position:0% +model has never seen a black cat before +seen a black dog though + + align:start position:0% +seen a black dog though + + + align:start position:0% +seen a black dog though +so now our model is confused what is + + align:start position:0% +so now our model is confused what is + + + align:start position:0% +so now our model is confused what is +this + + align:start position:0% + + + + align:start position:0% + +what am i referring to anybody know what + + align:start position:0% +what am i referring to anybody know what + + + align:start position:0% +what am i referring to anybody know what +this problem is + + align:start position:0% + + + + align:start position:0% + +answer from participant + + align:start position:0% +answer from participant + + + align:start position:0% +answer from participant +boundary conditions + + align:start position:0% +boundary conditions + + + align:start position:0% +boundary conditions +not quite this is a problem of bias + + align:start position:0% +not quite this is a problem of bias + + + align:start position:0% +not quite this is a problem of bias +there's a problem of bias in your + + align:start position:0% +there's a problem of bias in your + + + align:start position:0% +there's a problem of bias in your +dataset we don't have any black cats + + align:start position:0% +dataset we don't have any black cats + + + align:start position:0% +dataset we don't have any black cats +so our model is not great at recognizing + + align:start position:0% +so our model is not great at recognizing + + + align:start position:0% +so our model is not great at recognizing +black cats now you can imagine in + + align:start position:0% +black cats now you can imagine in + + + align:start position:0% +black cats now you can imagine in +medical context this becomes really + + align:start position:0% +medical context this becomes really + + + align:start position:0% +medical context this becomes really +problematic because we're training data + + align:start position:0% +problematic because we're training data + + + align:start position:0% +problematic because we're training data +on like mostly white people and mostly + + align:start position:0% +on like mostly white people and mostly + + + align:start position:0% +on like mostly white people and mostly +men for example and that doesn't help + + align:start position:0% +men for example and that doesn't help + + + align:start position:0% +men for example and that doesn't help +for not white people and for not men + + align:start position:0% +for not white people and for not men + + + align:start position:0% +for not white people and for not men +right because the model is going to + + align:start position:0% +right because the model is going to + + + align:start position:0% +right because the model is going to +learn as we saw statistics models are + + align:start position:0% +learn as we saw statistics models are + + + align:start position:0% +learn as we saw statistics models are +dumb + + align:start position:0% +dumb + + + align:start position:0% +dumb +models going to learn a whole bunch of + + align:start position:0% +models going to learn a whole bunch of + + + align:start position:0% +models going to learn a whole bunch of +things that are true about white people + + align:start position:0% +things that are true about white people + + + align:start position:0% +things that are true about white people +and men + + align:start position:0% +and men + + + align:start position:0% +and men +or about cats that are not black + + align:start position:0% +or about cats that are not black + + + align:start position:0% +or about cats that are not black +and then when presented + + align:start position:0% +and then when presented + + + align:start position:0% +and then when presented +with this other thing or this other type + + align:start position:0% +with this other thing or this other type + + + align:start position:0% +with this other thing or this other type +of thing + + align:start position:0% +of thing + + + align:start position:0% +of thing +the model has no idea what to do with it + + align:start position:0% +the model has no idea what to do with it + + + align:start position:0% +the model has no idea what to do with it +and just applies the same assumptions to + + align:start position:0% +and just applies the same assumptions to + + + align:start position:0% +and just applies the same assumptions to +this other thing so what's the lesson + + align:start position:0% +this other thing so what's the lesson + + + align:start position:0% +this other thing so what's the lesson +here + + align:start position:0% +here + + + align:start position:0% +here +make sure that your training data is + + align:start position:0% +make sure that your training data is + + + align:start position:0% +make sure that your training data is +representative + + align:start position:0% +representative + + + align:start position:0% +representative +and be very intentional about the way + + align:start position:0% +and be very intentional about the way + + + align:start position:0% +and be very intentional about the way +that you are collecting training data to + + align:start position:0% +that you are collecting training data to + + + align:start position:0% +that you are collecting training data to +make sure that it reflects the use case + + align:start position:0% +make sure that it reflects the use case + + + align:start position:0% +make sure that it reflects the use case +this goes back to + + align:start position:0% +this goes back to + + + align:start position:0% +this goes back to +problem + + align:start position:0% +problem + + + align:start position:0% +problem +definition what problem are we trying to + + align:start position:0% +definition what problem are we trying to + + + align:start position:0% +definition what problem are we trying to +solve + + align:start position:0% +solve + + + align:start position:0% +solve +who is our end user what are we hoping + + align:start position:0% +who is our end user what are we hoping + + + align:start position:0% +who is our end user what are we hoping +to accomplish right all these things + + align:start position:0% +to accomplish right all these things + + + align:start position:0% +to accomplish right all these things +that have to happen in good engineering + + align:start position:0% +that have to happen in good engineering + + + align:start position:0% +that have to happen in good engineering +yeah this is a great example so if we + + align:start position:0% +yeah this is a great example so if we + + + align:start position:0% +yeah this is a great example so if we +use ai to find what makes a good pilot + + align:start position:0% +use ai to find what makes a good pilot + + + align:start position:0% +use ai to find what makes a good pilot +the ai is going to say oh probably white + + align:start position:0% +the ai is going to say oh probably white + + + align:start position:0% +the ai is going to say oh probably white +guys white guys are good pilots + + align:start position:0% + + + + align:start position:0% + +i can't solve this problem for you guys + + align:start position:0% +i can't solve this problem for you guys + + + align:start position:0% +i can't solve this problem for you guys +but i can make you aware of it so you're + + align:start position:0% +but i can make you aware of it so you're + + + align:start position:0% +but i can make you aware of it so you're +asking the right questions + + align:start position:0% + + + + align:start position:0% + +so right and of course the model will + + align:start position:0% +so right and of course the model will + + + align:start position:0% +so right and of course the model will +eventually know that this is a cat + + align:start position:0% +eventually know that this is a cat + + + align:start position:0% +eventually know that this is a cat +hopefully + + align:start position:0% +hopefully + + + align:start position:0% +hopefully +so now step seven deploy the model you + + align:start position:0% +so now step seven deploy the model you + + + align:start position:0% +so now step seven deploy the model you +can do this on amazon web services you + + align:start position:0% +can do this on amazon web services you + + + align:start position:0% +can do this on amazon web services you +can make it publicly accessible you can + + align:start position:0% +can make it publicly accessible you can + + + align:start position:0% +can make it publicly accessible you can +put it on a secure + + align:start position:0% +put it on a secure + + + align:start position:0% +put it on a secure +on a secure hard drive somewhere + + align:start position:0% +on a secure hard drive somewhere + + + align:start position:0% +on a secure hard drive somewhere +you know + + align:start position:0% +you know + + + align:start position:0% +you know +however you guys are going to use it + + align:start position:0% +however you guys are going to use it + + + align:start position:0% +however you guys are going to use it +that will dictate how to deploy it so + + align:start position:0% +that will dictate how to deploy it so + + + align:start position:0% +that will dictate how to deploy it so +everything flows from problem definition + + align:start position:0% +everything flows from problem definition + + + align:start position:0% +everything flows from problem definition +you can put it on a chip but to review + + align:start position:0% +you can put it on a chip but to review + + + align:start position:0% +you can put it on a chip but to review +we have + + align:start position:0% +we have + + + align:start position:0% +we have +define a problem + + align:start position:0% +define a problem + + + align:start position:0% +define a problem +find data + + align:start position:0% +find data + + + align:start position:0% +find data +clean data + + align:start position:0% +clean data + + + align:start position:0% +clean data +choose a model + + align:start position:0% +choose a model + + + align:start position:0% +choose a model +train the model + + align:start position:0% +train the model + + + align:start position:0% +train the model +test the model + + align:start position:0% +test the model + + + align:start position:0% +test the model +oopsies + + align:start position:0% +oopsies + + + align:start position:0% +oopsies +and then deploy the bible + + align:start position:0% + + + + align:start position:0% + +questions on this process + + align:start position:0% + + + + align:start position:0% + +question from participant + + align:start position:0% +question from participant + + + align:start position:0% +question from participant +is this the typical approach regardless + + align:start position:0% +is this the typical approach regardless + + + align:start position:0% +is this the typical approach regardless +of the model that is used + + align:start position:0% +of the model that is used + + + align:start position:0% +of the model that is used +i think so + + align:start position:0% +i think so + + + align:start position:0% +i think so +implicitly or explicitly this is + + align:start position:0% +implicitly or explicitly this is + + + align:start position:0% +implicitly or explicitly this is +generally the process sorry go ahead + + align:start position:0% +generally the process sorry go ahead + + + align:start position:0% +generally the process sorry go ahead +jennifer + + align:start position:0% +jennifer + + + align:start position:0% +jennifer +question from participant + + align:start position:0% +question from participant + + + align:start position:0% +question from participant +so if you showed the model a guinea pig + + align:start position:0% +so if you showed the model a guinea pig + + + align:start position:0% +so if you showed the model a guinea pig +it would try to classify it as a dog cat + + align:start position:0% +it would try to classify it as a dog cat + + + align:start position:0% +it would try to classify it as a dog cat +because those are the options we had + + align:start position:0% +because those are the options we had + + + align:start position:0% +because those are the options we had +presented + + align:start position:0% +presented + + + align:start position:0% +presented +correct so that's so that's step four + + align:start position:0% +correct so that's so that's step four + + + align:start position:0% +correct so that's so that's step four +what model are we using and the model + + align:start position:0% +what model are we using and the model + + + align:start position:0% +what model are we using and the model +architecture might limit you there's + + align:start position:0% +architecture might limit you there's + + + align:start position:0% +architecture might limit you there's +only two outputs either cat or dog you + + align:start position:0% +only two outputs either cat or dog you + + + align:start position:0% +only two outputs either cat or dog you +don't have a third outfit you need a + + align:start position:0% +don't have a third outfit you need a + + + align:start position:0% +don't have a third outfit you need a +third + + align:start position:0% +third + + + align:start position:0% +third +you need to make space for that + + align:start position:0% + + + + align:start position:0% + +question from participant + + align:start position:0% +question from participant + + + align:start position:0% +question from participant +i'm working on a master's degree and i + + align:start position:0% +i'm working on a master's degree and i + + + align:start position:0% +i'm working on a master's degree and i +completed a class in data analytics + + align:start position:0% +completed a class in data analytics + + + align:start position:0% +completed a class in data analytics +i was working with r + + align:start position:0% +i was working with r + + + align:start position:0% +i was working with r +and one of the questions i had at the + + align:start position:0% +and one of the questions i had at the + + + align:start position:0% +and one of the questions i had at the +end of the class + + align:start position:0% +end of the class + + + align:start position:0% +end of the class +was is there an ai program or progress + + align:start position:0% +was is there an ai program or progress + + + align:start position:0% +was is there an ai program or progress +towards ai + + align:start position:0% +towards ai + + + align:start position:0% +towards ai +that clean data + + align:start position:0% +that clean data + + + align:start position:0% +that clean data +there are i think they're working on it + + align:start position:0% +there are i think they're working on it + + + align:start position:0% +there are i think they're working on it +there's like auto ml tools um + + align:start position:0% +there's like auto ml tools um + + + align:start position:0% +there's like auto ml tools um +which are trying to democratize ai where + + align:start position:0% +which are trying to democratize ai where + + + align:start position:0% +which are trying to democratize ai where +but but even then my guess is that + + align:start position:0% +but but even then my guess is that + + + align:start position:0% +but but even then my guess is that +you would have to + + align:start position:0% +you would have to + + + align:start position:0% +you would have to +input the data in a way that it finds + + align:start position:0% +input the data in a way that it finds + + + align:start position:0% +input the data in a way that it finds +useful and then it takes it from there + + align:start position:0% +useful and then it takes it from there + + + align:start position:0% +useful and then it takes it from there +i don't know about cleaning the data i + + align:start position:0% +i don't know about cleaning the data i + + + align:start position:0% +i don't know about cleaning the data i +really don't know + + align:start position:0% +really don't know + + + align:start position:0% +really don't know +any other questions before we move on to + + align:start position:0% +any other questions before we move on to + + + align:start position:0% +any other questions before we move on to +summary and conclusion + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +to conclude + + align:start position:0% +to conclude + + + align:start position:0% +to conclude +we've covered an intro to artificial + + align:start position:0% +we've covered an intro to artificial + + + align:start position:0% +we've covered an intro to artificial +intelligence we've seen step-by-step how + + align:start position:0% +intelligence we've seen step-by-step how + + + align:start position:0% +intelligence we've seen step-by-step how +to train an algorithm and to close i + + align:start position:0% +to train an algorithm and to close i + + + align:start position:0% +to train an algorithm and to close i +want to leave you all with four + + align:start position:0% +want to leave you all with four + + + align:start position:0% +want to leave you all with four +questions and a word of caution + + align:start position:0% +questions and a word of caution + + + align:start position:0% +questions and a word of caution +four questions + + align:start position:0% +four questions + + + align:start position:0% +four questions +you should ask about any ai that you + + align:start position:0% +you should ask about any ai that you + + + align:start position:0% +you should ask about any ai that you +encounter + + align:start position:0% +encounter + + + align:start position:0% +encounter +whether you're trying to assess it or + + align:start position:0% +whether you're trying to assess it or + + + align:start position:0% +whether you're trying to assess it or +use it + + align:start position:0% +use it + + + align:start position:0% +use it +four questions you should always ask + + align:start position:0% +four questions you should always ask + + + align:start position:0% +four questions you should always ask +number one what is the goal problem + + align:start position:0% +number one what is the goal problem + + + align:start position:0% +number one what is the goal problem +definition right what is the goal + + align:start position:0% +definition right what is the goal + + + align:start position:0% +definition right what is the goal +what problem are you solving what are + + align:start position:0% +what problem are you solving what are + + + align:start position:0% +what problem are you solving what are +its inputs and its outputs + + align:start position:0% +its inputs and its outputs + + + align:start position:0% +its inputs and its outputs +what does the thing do + + align:start position:0% +what does the thing do + + + align:start position:0% +what does the thing do +it's number one number two + + align:start position:0% +it's number one number two + + + align:start position:0% +it's number one number two +what is the training data + + align:start position:0% +what is the training data + + + align:start position:0% +what is the training data +where did it come from how is it + + align:start position:0% +where did it come from how is it + + + align:start position:0% +where did it come from how is it +prepared + + align:start position:0% +prepared + + + align:start position:0% +prepared +how did you make sure did you check for + + align:start position:0% +how did you make sure did you check for + + + align:start position:0% +how did you make sure did you check for +this bias or that bias how did you make + + align:start position:0% +this bias or that bias how did you make + + + align:start position:0% +this bias or that bias how did you make +sure that it's balanced + + align:start position:0% + + + + align:start position:0% + +number three what kind of model did you + + align:start position:0% +number three what kind of model did you + + + align:start position:0% +number three what kind of model did you +use why + + align:start position:0% +use why + + + align:start position:0% +use why +is it interpretable + + align:start position:0% +is it interpretable + + + align:start position:0% +is it interpretable +should it be + + align:start position:0% +should it be + + + align:start position:0% +should it be +how did you pick this model + + align:start position:0% + + + + align:start position:0% + +and number four what's the accuracy when + + align:start position:0% +and number four what's the accuracy when + + + align:start position:0% +and number four what's the accuracy when +you test it on new data when you test it + + align:start position:0% +you test it on new data when you test it + + + align:start position:0% +you test it on new data when you test it +on testing data not training data when + + align:start position:0% +on testing data not training data when + + + align:start position:0% +on testing data not training data when +you give it a whole new set of data that + + align:start position:0% +you give it a whole new set of data that + + + align:start position:0% +you give it a whole new set of data that +has never seen what is its accuracy + + align:start position:0% + + + + align:start position:0% + +the reinforcement learning version of + + align:start position:0% +the reinforcement learning version of + + + align:start position:0% +the reinforcement learning version of +this would be what happens when you test + + align:start position:0% +this would be what happens when you test + + + align:start position:0% +this would be what happens when you test +it in a different simulation or in the + + align:start position:0% +it in a different simulation or in the + + + align:start position:0% +it in a different simulation or in the +real world + + align:start position:0% +real world + + + align:start position:0% +real world +right but like something there has to be + + align:start position:0% +right but like something there has to be + + + align:start position:0% +right but like something there has to be +some question about like how well does + + align:start position:0% +some question about like how well does + + + align:start position:0% +some question about like how well does +this actually do when it's given a + + align:start position:0% +this actually do when it's given a + + + align:start position:0% +this actually do when it's given a +problem that it has not + + align:start position:0% +problem that it has not + + + align:start position:0% +problem that it has not +had the opportunity to memorize + + align:start position:0% +had the opportunity to memorize + + + align:start position:0% +had the opportunity to memorize +so + + align:start position:0% +so + + + align:start position:0% +so +goal training data model accuracy if you + + align:start position:0% +goal training data model accuracy if you + + + align:start position:0% +goal training data model accuracy if you +keep these four questions in mind you'll + + align:start position:0% +keep these four questions in mind you'll + + + align:start position:0% +keep these four questions in mind you'll +be better able to assess any ai system + + align:start position:0% +be better able to assess any ai system + + + align:start position:0% +be better able to assess any ai system +that you encounter + + align:start position:0% + + + + align:start position:0% + +and now let me close with a word of + + align:start position:0% +and now let me close with a word of + + + align:start position:0% +and now let me close with a word of +caution + + align:start position:0% +caution + + + align:start position:0% +caution +developing an ai model can be very + + align:start position:0% +developing an ai model can be very + + + align:start position:0% +developing an ai model can be very +difficult + + align:start position:0% +difficult + + + align:start position:0% +difficult +it can also be very valuable + + align:start position:0% +it can also be very valuable + + + align:start position:0% +it can also be very valuable +and it can also be very seductive + + align:start position:0% +and it can also be very seductive + + + align:start position:0% +and it can also be very seductive +it is a task + + align:start position:0% +it is a task + + + align:start position:0% +it is a task +if the task does not belong to a + + align:start position:0% +if the task does not belong to a + + + align:start position:0% +if the task does not belong to a +strategy in support of certain + + align:start position:0% +strategy in support of certain + + + align:start position:0% +strategy in support of certain +objectives that measure a mission that + + align:start position:0% +objectives that measure a mission that + + + align:start position:0% +objectives that measure a mission that +reflect values it is not a good use of + + align:start position:0% +reflect values it is not a good use of + + + align:start position:0% +reflect values it is not a good use of +time + + align:start position:0% +time + + + align:start position:0% +time +even if it is really cool + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +when i say goal + + align:start position:0% +when i say goal + + + align:start position:0% +when i say goal +i'm talking again both at a low level + + align:start position:0% +i'm talking again both at a low level + + + align:start position:0% +i'm talking again both at a low level +inputs and outputs in this model but + + align:start position:0% +inputs and outputs in this model but + + + align:start position:0% +inputs and outputs in this model but +also at a high level what are we trying + + align:start position:0% +also at a high level what are we trying + + + align:start position:0% +also at a high level what are we trying +to do + + align:start position:0% +to do + + + align:start position:0% +to do +and it's important that we constantly + + align:start position:0% +and it's important that we constantly + + + align:start position:0% +and it's important that we constantly +re-evaluate the low-level goals with + + align:start position:0% +re-evaluate the low-level goals with + + + align:start position:0% +re-evaluate the low-level goals with +respect to the high level problem + + align:start position:0% +respect to the high level problem + + + align:start position:0% +respect to the high level problem +we want to situate the model and the + + align:start position:0% +we want to situate the model and the + + + align:start position:0% +we want to situate the model and the +training and the data within a broader + + align:start position:0% +training and the data within a broader + + + align:start position:0% +training and the data within a broader +problem-solving context + + align:start position:0% + + + + align:start position:0% + +if i were looking + + align:start position:0% +if i were looking + + + align:start position:0% +if i were looking +at the air force and trying to figure + + align:start position:0% +at the air force and trying to figure + + + align:start position:0% +at the air force and trying to figure +out where would ai or where to implement + + align:start position:0% +out where would ai or where to implement + + + align:start position:0% +out where would ai or where to implement +ai i would start here + + align:start position:0% +ai i would start here + + + align:start position:0% +ai i would start here +i would start with identifying what are + + align:start position:0% +i would start with identifying what are + + + align:start position:0% +i would start with identifying what are +the values what's the mission objectives + + align:start position:0% +the values what's the mission objectives + + + align:start position:0% +the values what's the mission objectives +strategy tasks + + align:start position:0% +strategy tasks + + + align:start position:0% +strategy tasks +kind of as a tree + + align:start position:0% +kind of as a tree + + + align:start position:0% +kind of as a tree +and i would identify problems what are + + align:start position:0% +and i would identify problems what are + + + align:start position:0% +and i would identify problems what are +the gaps between our aspirations and our + + align:start position:0% +the gaps between our aspirations and our + + + align:start position:0% +the gaps between our aspirations and our +reality + + align:start position:0% +reality + + + align:start position:0% +reality +then i would think critically about + + align:start position:0% +then i would think critically about + + + align:start position:0% +then i would think critically about +which gaps artificial intelligence + + align:start position:0% +which gaps artificial intelligence + + + align:start position:0% +which gaps artificial intelligence +actually could fill + + align:start position:0% +actually could fill + + + align:start position:0% +actually could fill +and whether those gaps would be + + align:start position:0% +and whether those gaps would be + + + align:start position:0% +and whether those gaps would be +partially or completely filled + + align:start position:0% + + + + align:start position:0% + +if you have data that's unused that + + align:start position:0% +if you have data that's unused that + + + align:start position:0% +if you have data that's unused that +presents an opportunity if you have + + align:start position:0% +presents an opportunity if you have + + + align:start position:0% +presents an opportunity if you have +tasks that require a lot of people that + + align:start position:0% +tasks that require a lot of people that + + + align:start position:0% +tasks that require a lot of people that +presents an opportunity if you have + + align:start position:0% +presents an opportunity if you have + + + align:start position:0% +presents an opportunity if you have +tasks that are complex or require a lot + + align:start position:0% +tasks that are complex or require a lot + + + align:start position:0% +tasks that are complex or require a lot +of thinking and processing data + + align:start position:0% +of thinking and processing data + + + align:start position:0% +of thinking and processing data +those are problems where ai can help + + align:start position:0% + + + + align:start position:0% + +if you have a problem with drug + + align:start position:0% +if you have a problem with drug + + + align:start position:0% +if you have a problem with drug +overdoses or with suicides ai is + + align:start position:0% +overdoses or with suicides ai is + + + align:start position:0% +overdoses or with suicides ai is +probably not going to help + + align:start position:0% +probably not going to help + + + align:start position:0% +probably not going to help +and in fact i've heard of + + align:start position:0% +and in fact i've heard of + + + align:start position:0% +and in fact i've heard of +cases where + + align:start position:0% +cases where + + + align:start position:0% +cases where +people collect data and they do all this + + align:start position:0% +people collect data and they do all this + + + align:start position:0% +people collect data and they do all this +quantitative analysis but this is + + align:start position:0% +quantitative analysis but this is + + + align:start position:0% +quantitative analysis but this is +fundamentally a human problem + + align:start position:0% + + + + align:start position:0% + +and so it can be actually quite + + align:start position:0% +and so it can be actually quite + + + align:start position:0% +and so it can be actually quite +distracting + + align:start position:0% +distracting + + + align:start position:0% +distracting +so my point is simply that at its best + + align:start position:0% +so my point is simply that at its best + + + align:start position:0% +so my point is simply that at its best +ai can make the air force more efficient + + align:start position:0% +ai can make the air force more efficient + + + align:start position:0% +ai can make the air force more efficient +more effective and it's worse it can + + align:start position:0% +more effective and it's worse it can + + + align:start position:0% +more effective and it's worse it can +distract us from actually solving + + align:start position:0% +distract us from actually solving + + + align:start position:0% +distract us from actually solving +difficult challenging + + align:start position:0% +difficult challenging + + + align:start position:0% +difficult challenging +human and cultural problems + + align:start position:0% +human and cultural problems + + + align:start position:0% +human and cultural problems +so it's really important to be + + align:start position:0% +so it's really important to be + + + align:start position:0% +so it's really important to be +discerning about what kind of problem + + align:start position:0% +discerning about what kind of problem + + + align:start position:0% +discerning about what kind of problem +you're trying to solve and where ai can + + align:start position:0% +you're trying to solve and where ai can + + + align:start position:0% +you're trying to solve and where ai can +help but at this point i hope and i + + align:start position:0% +help but at this point i hope and i + + + align:start position:0% +help but at this point i hope and i +think that you have the tools to prevent + + align:start position:0% +think that you have the tools to prevent + + + align:start position:0% +think that you have the tools to prevent +that from happening and to harness this + + align:start position:0% +that from happening and to harness this + + + align:start position:0% +that from happening and to harness this +very powerful new technology in support + + align:start position:0% +very powerful new technology in support + + + align:start position:0% +very powerful new technology in support +of building a more effective air force + + align:start position:0% +of building a more effective air force + + + align:start position:0% +of building a more effective air force +and pursuing america's interests so + + align:start position:0% +and pursuing america's interests so + + + align:start position:0% +and pursuing america's interests so +thank you all so much + + align:start position:0% +thank you all so much + + + align:start position:0% +thank you all so much +i'm gonna stick around for questions + + align:start position:0% +i'm gonna stick around for questions + + + align:start position:0% +i'm gonna stick around for questions +and i will leave you with this + + align:start position:0% +and i will leave you with this + + + align:start position:0% +and i will leave you with this +conclusion + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/LmE_mdugLWE.txt b/LmE_mdugLWE.txt new file mode 100644 index 0000000000000000000000000000000000000000..57bb859f81079614c1958ddd871813bf39ec6973 --- /dev/null +++ b/LmE_mdugLWE.txt @@ -0,0 +1,17643 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT + + align:start position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencourseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu what are the biggest + + align:start position:0% +ocw.mit.edu what are the biggest + + + align:start position:0% +ocw.mit.edu what are the biggest +problems that the world faces and uh + + align:start position:0% +problems that the world faces and uh + + + align:start position:0% +problems that the world faces and uh +what should we be doing to them and it + + align:start position:0% +what should we be doing to them and it + + + align:start position:0% +what should we be doing to them and it +started with some conversation + + align:start position:0% +started with some conversation + + + align:start position:0% +started with some conversation +about um global warming and climate + + align:start position:0% +about um global warming and climate + + + align:start position:0% +about um global warming and climate +change or whatever you want to call it + + align:start position:0% +change or whatever you want to call it + + + align:start position:0% +change or whatever you want to call it +and + + align:start position:0% +and + + + align:start position:0% +and +um this friend of mine um likes to + + align:start position:0% +um this friend of mine um likes to + + + align:start position:0% +um this friend of mine um likes to +organize + + align:start position:0% +organize + + + align:start position:0% +organize +meetings + + align:start position:0% +meetings + + + align:start position:0% +meetings +and uh he said well that looks like a + + align:start position:0% +and uh he said well that looks like a + + + align:start position:0% +and uh he said well that looks like a +real disaster in the next 50 years and + + align:start position:0% +real disaster in the next 50 years and + + + align:start position:0% +real disaster in the next 50 years and +um maybe the ocean will rise two or five + + align:start position:0% +um maybe the ocean will rise two or five + + + align:start position:0% +um maybe the ocean will rise two or five +meters and that will remove the habitat + + align:start position:0% +meters and that will remove the habitat + + + align:start position:0% +meters and that will remove the habitat +of 20% of all the people in the world + + align:start position:0% +of 20% of all the people in the world + + + align:start position:0% +of 20% of all the people in the world +and they'll all move somewhere else and + + align:start position:0% +and they'll all move somewhere else and + + + align:start position:0% +and they'll all move somewhere else and +the places that they move will already + + align:start position:0% +the places that they move will already + + + align:start position:0% +the places that they move will already +be full of people because we're talking + + align:start position:0% +be full of people because we're talking + + + align:start position:0% +be full of people because we're talking +about 2050 or 60 and + + align:start position:0% +about 2050 or 60 and + + + align:start position:0% +about 2050 or 60 and +um there will be various arguments + + align:start position:0% +um there will be various arguments + + + align:start position:0% +um there will be various arguments +about um the few resources left on the + + align:start position:0% +about um the few resources left on the + + + align:start position:0% +about um the few resources left on the +planet um + + align:start position:0% +planet um + + + align:start position:0% +planet um +so we were talking about that a little + + align:start position:0% +so we were talking about that a little + + + align:start position:0% +so we were talking about that a little +bit and U then the question came up + + align:start position:0% +bit and U then the question came up + + + align:start position:0% +bit and U then the question came up +well maybe that's just one of a dozen + + align:start position:0% +well maybe that's just one of a dozen + + + align:start position:0% +well maybe that's just one of a dozen +other disasters and so I started + + align:start position:0% +other disasters and so I started + + + align:start position:0% +other disasters and so I started +cataloging possible disasters and uh + + align:start position:0% +cataloging possible disasters and uh + + + align:start position:0% +cataloging possible disasters and uh +anyway this + + align:start position:0% +anyway this + + + align:start position:0% +anyway this +philanthropist + + align:start position:0% +philanthropist + + + align:start position:0% +philanthropist +uh said well let's uh have a conference + + align:start position:0% +uh said well let's uh have a conference + + + align:start position:0% +uh said well let's uh have a conference +to discuss that and if we see if we can + + align:start position:0% +to discuss that and if we see if we can + + + align:start position:0% +to discuss that and if we see if we can +find some serious problem that nobody + + align:start position:0% +find some serious problem that nobody + + + align:start position:0% +find some serious problem that nobody +has noticed and uh so on and so forth so + + align:start position:0% +has noticed and uh so on and so forth so + + + align:start position:0% +has noticed and uh so on and so forth so +what what do you think um now + + align:start position:0% +what what do you think um now + + + align:start position:0% +what what do you think um now +when During the period when AI looked uh + + align:start position:0% +when During the period when AI looked uh + + + align:start position:0% +when During the period when AI looked uh +like it was progressing rapidly uh lots + + align:start position:0% +like it was progressing rapidly uh lots + + + align:start position:0% +like it was progressing rapidly uh lots +of people uh got panicked and uh went + + align:start position:0% +of people uh got panicked and uh went + + + align:start position:0% +of people uh got panicked and uh went +into science fiction mode and said well + + align:start position:0% +into science fiction mode and said well + + + align:start position:0% +into science fiction mode and said well +what if + + align:start position:0% +what if + + + align:start position:0% +what if +the fact two + + align:start position:0% +the fact two + + + align:start position:0% +the fact two +novels uh I was + + align:start position:0% +novels uh I was + + + align:start position:0% +novels uh I was +found very impressive one was Colossus + + align:start position:0% +found very impressive one was Colossus + + + align:start position:0% +found very impressive one was Colossus +by English writer named DF Jones any of + + align:start position:0% +by English writer named DF Jones any of + + + align:start position:0% +by English writer named DF Jones any of +you read + + align:start position:0% +you read + + + align:start position:0% +you read +that uh it went it became a movie called + + align:start position:0% +that uh it went it became a movie called + + + align:start position:0% +that uh it went it became a movie called +the forbin + + align:start position:0% +the forbin + + + align:start position:0% +the forbin +project uh movie wasn't terribly good + + align:start position:0% +project uh movie wasn't terribly good + + + align:start position:0% +project uh movie wasn't terribly good +but but the thesis was that uh if you + + align:start position:0% +but but the thesis was that uh if you + + + align:start position:0% +but but the thesis was that uh if you +started fooling around with AI and you + + align:start position:0% +started fooling around with AI and you + + + align:start position:0% +started fooling around with AI and you +got really fast + + align:start position:0% +got really fast + + + align:start position:0% +got really fast +supercomputers then uh maybe the thing + + align:start position:0% +supercomputers then uh maybe the thing + + + align:start position:0% +supercomputers then uh maybe the thing +would uh start evolving because if you + + align:start position:0% +would uh start evolving because if you + + + align:start position:0% +would uh start evolving because if you +can't solve a problem what do you do you + + align:start position:0% +can't solve a problem what do you do you + + + align:start position:0% +can't solve a problem what do you do you +try a lot of things and then you uh see + + align:start position:0% +try a lot of things and then you uh see + + + align:start position:0% +try a lot of things and then you uh see +which of them seem to be uh leading to + + align:start position:0% +which of them seem to be uh leading to + + + align:start position:0% +which of them seem to be uh leading to +some improvement and then you collect + + align:start position:0% +some improvement and then you collect + + + align:start position:0% +some improvement and then you collect +the programs that uh seem to make a + + align:start position:0% +the programs that uh seem to make a + + + align:start position:0% +the programs that uh seem to make a +little progress and mix their parts and + + align:start position:0% +little progress and mix their parts and + + + align:start position:0% +little progress and mix their parts and +uh recombine them and um in fact maybe + + align:start position:0% +uh recombine them and um in fact maybe + + + align:start position:0% +uh recombine them and um in fact maybe +half a dozen projects in the last 50 + + align:start position:0% +half a dozen projects in the last 50 + + + align:start position:0% +half a dozen projects in the last 50 +years have been people who said oh uh + + align:start position:0% +years have been people who said oh uh + + + align:start position:0% +years have been people who said oh uh +instead of trying to program an + + align:start position:0% +instead of trying to program an + + + align:start position:0% +instead of trying to program an +intelligent machine why don't we just + + align:start position:0% +intelligent machine why don't we just + + + align:start position:0% +intelligent machine why don't we just +evolve one by generating lots of random + + align:start position:0% +evolve one by generating lots of random + + + align:start position:0% +evolve one by generating lots of random +code and giving it problems and + + align:start position:0% +code and giving it problems and + + + align:start position:0% +code and giving it problems and +selecting the ones that work and taking + + align:start position:0% +selecting the ones that work and taking + + + align:start position:0% +selecting the ones that work and taking +pieces of their DNA and recombining them + + align:start position:0% +pieces of their DNA and recombining them + + + align:start position:0% +pieces of their DNA and recombining them +and there's about a dozen such pro + + align:start position:0% +and there's about a dozen such pro + + + align:start position:0% +and there's about a dozen such pro +programs and I don't think I could + + align:start position:0% +programs and I don't think I could + + + align:start position:0% +programs and I don't think I could +remember them all Larry Fogle had one so + + align:start position:0% +remember them all Larry Fogle had one so + + + align:start position:0% +remember them all Larry Fogle had one so +if you look + + align:start position:0% +if you look + + + align:start position:0% +if you look +up I think it's f o g e + + align:start position:0% +up I think it's f o g e + + + align:start position:0% +up I think it's f o g e +l and + + align:start position:0% + + + + align:start position:0% + +uh to make a short story even + + align:start position:0% +uh to make a short story even + + + align:start position:0% +uh to make a short story even +shorter uh all of them showed signs of + + align:start position:0% +shorter uh all of them showed signs of + + + align:start position:0% +shorter uh all of them showed signs of +progress and then flattened out the most + + align:start position:0% +progress and then flattened out the most + + + align:start position:0% +progress and then flattened out the most +impressive one was + + align:start position:0% +impressive one was + + + align:start position:0% +impressive one was +the I think I mentioned them briefly by + + align:start position:0% +the I think I mentioned them briefly by + + + align:start position:0% +the I think I mentioned them briefly by +lenat Douglas + + align:start position:0% + + + + align:start position:0% + +lenat and he he had the one that uh he + + align:start position:0% +lenat and he he had the one that uh he + + + align:start position:0% +lenat and he he had the one that uh he +set toward discovering + + align:start position:0% +set toward discovering + + + align:start position:0% +set toward discovering +mathematics and + + align:start position:0% +mathematics and + + + align:start position:0% +mathematics and +uh it was a list set of list programs so + + align:start position:0% +uh it was a list set of list programs so + + + align:start position:0% +uh it was a list set of list programs so +U there's a list function which was the + + align:start position:0% +U there's a list function which was the + + + align:start position:0% +U there's a list function which was the +length of a list which means that list + + align:start position:0% +length of a list which means that list + + + align:start position:0% +length of a list which means that list +knows can represent numbers a little bit + + align:start position:0% +knows can represent numbers a little bit + + + align:start position:0% +knows can represent numbers a little bit +and + + align:start position:0% +and + + + align:start position:0% +and +U uh this program called automated + + align:start position:0% +U uh this program called automated + + + align:start position:0% +U uh this program called automated +mathematician uh computed various + + align:start position:0% +mathematician uh computed various + + + align:start position:0% +mathematician uh computed various +functions of of sets and it would make + + align:start position:0% +functions of of sets and it would make + + + align:start position:0% +functions of of sets and it would make +new sets and that's the one that uh + + align:start position:0% +new sets and that's the one that uh + + + align:start position:0% +new sets and that's the one that uh +discovered prime numbers except that uh + + align:start position:0% +discovered prime numbers except that uh + + + align:start position:0% +discovered prime numbers except that uh +it concluded that nine was a prime for + + align:start position:0% +it concluded that nine was a prime for + + + align:start position:0% +it concluded that nine was a prime for +some reason but that didn't bother it + + align:start position:0% +some reason but that didn't bother it + + + align:start position:0% +some reason but that didn't bother it +much because then it + + align:start position:0% +much because then it + + + align:start position:0% +much because then it +invented uh all sorts of other + + align:start position:0% +invented uh all sorts of other + + + align:start position:0% +invented uh all sorts of other +uh Elementary mathematical processes and + + align:start position:0% +uh Elementary mathematical processes and + + + align:start position:0% +uh Elementary mathematical processes and +of course every now and then it would + + align:start position:0% +of course every now and then it would + + + align:start position:0% +of course every now and then it would +get something wrong but who cares if it + + align:start position:0% +get something wrong but who cares if it + + + align:start position:0% +get something wrong but who cares if it +got a lot of them right it would reward + + align:start position:0% +got a lot of them right it would reward + + + align:start position:0% +got a lot of them right it would reward +it and so on + + align:start position:0% +it and so on + + + align:start position:0% +it and so on +um anyway it flattened out I think I + + align:start position:0% +um anyway it flattened out I think I + + + align:start position:0% +um anyway it flattened out I think I +told this story the other day later he + + align:start position:0% +told this story the other day later he + + + align:start position:0% +told this story the other day later he +won this contest of simulated Naval + + align:start position:0% +won this contest of simulated Naval + + + align:start position:0% +won this contest of simulated Naval +engagements which the naval war + + align:start position:0% +engagements which the naval war + + + align:start position:0% +engagements which the naval war +College + + align:start position:0% +College + + + align:start position:0% +College +um had an annual contest how do you + + align:start position:0% +um had an annual contest how do you + + + align:start position:0% +um had an annual contest how do you +program a fleet to defeat another Fleet + + align:start position:0% +program a fleet to defeat another Fleet + + + align:start position:0% +program a fleet to defeat another Fleet +and L Net's Fleet + + align:start position:0% +and L Net's Fleet + + + align:start position:0% +and L Net's Fleet +uh yeah I did tell that uh a fleet can + + align:start position:0% +uh yeah I did tell that uh a fleet can + + + align:start position:0% +uh yeah I did tell that uh a fleet can +only go as fast as its slowest ship so + + align:start position:0% +only go as fast as its slowest ship so + + + align:start position:0% +only go as fast as its slowest ship so +lenet Fleet unlike all the others turned + + align:start position:0% +lenet Fleet unlike all the others turned + + + align:start position:0% +lenet Fleet unlike all the others turned +its guns backwards and sunk its slowest + + align:start position:0% +its guns backwards and sunk its slowest + + + align:start position:0% +its guns backwards and sunk its slowest +ship repeatedly and uh this enabled it + + align:start position:0% +ship repeatedly and uh this enabled it + + + align:start position:0% +ship repeatedly and uh this enabled it +to win all the battles because uh the + + align:start position:0% +to win all the battles because uh the + + + align:start position:0% +to win all the battles because uh the +the other people who have been to Naval + + align:start position:0% +the other people who have been to Naval + + + align:start position:0% +the other people who have been to Naval +War College spent a lot of time writing + + align:start position:0% +War College spent a lot of time writing + + + align:start position:0% +War College spent a lot of time writing +progam prams that would defend their + + align:start position:0% +progam prams that would defend their + + + align:start position:0% +progam prams that would defend their +weakest + + align:start position:0% + + + + align:start position:0% + +ship I'm not sure what the moral of that + + align:start position:0% +ship I'm not sure what the moral of that + + + align:start position:0% +ship I'm not sure what the moral of that +is if you're fighting a war you have to + + align:start position:0% +is if you're fighting a war you have to + + + align:start position:0% +is if you're fighting a war you have to +change your ordinary value + + align:start position:0% + + + + align:start position:0% + +system anyway of course at the same time + + align:start position:0% +system anyway of course at the same time + + + align:start position:0% +system anyway of course at the same time +there were lots of people who took these + + align:start position:0% +there were lots of people who took these + + + align:start position:0% +there were lots of people who took these +scenario seriously and said uh the AI + + align:start position:0% +scenario seriously and said uh the AI + + + align:start position:0% +scenario seriously and said uh the AI +and this whole group of them today uh + + align:start position:0% +and this whole group of them today uh + + + align:start position:0% +and this whole group of them today uh +called they say they're doing research + + align:start position:0% +called they say they're doing research + + + align:start position:0% +called they say they're doing research +on how to make friendly AIS and I regard + + align:start position:0% +on how to make friendly AIS and I regard + + + align:start position:0% +on how to make friendly AIS and I regard +this as exceedingly comical because they + + align:start position:0% +this as exceedingly comical because they + + + align:start position:0% +this as exceedingly comical because they +don't know how to make anything as smart + + align:start position:0% +don't know how to make anything as smart + + + align:start position:0% +don't know how to make anything as smart +as a 18-month-old child or uh or your + + align:start position:0% +as a 18-month-old child or uh or your + + + align:start position:0% +as a 18-month-old child or uh or your +favorite dog and uh however the scenario + + align:start position:0% +favorite dog and uh however the scenario + + + align:start position:0% +favorite dog and uh however the scenario +in the uh Colossus novel is that yes + + align:start position:0% +in the uh Colossus novel is that yes + + + align:start position:0% +in the uh Colossus novel is that yes +progress is slow for a while but then + + align:start position:0% +progress is slow for a while but then + + + align:start position:0% +progress is slow for a while but then +suddenly it goes from being good at + + align:start position:0% +suddenly it goes from being good at + + + align:start position:0% +suddenly it goes from being good at +something to uh getting control of all + + align:start position:0% +something to uh getting control of all + + + align:start position:0% +something to uh getting control of all +the other computers in the world in the + + align:start position:0% +the other computers in the world in the + + + align:start position:0% +the other computers in the world in the +next 15 minutes including another one in + + align:start position:0% +next 15 minutes including another one in + + + align:start position:0% +next 15 minutes including another one in +Russia which by some remarkable + + align:start position:0% +Russia which by some remarkable + + + align:start position:0% +Russia which by some remarkable +coincidence has also become smart around + + align:start position:0% +coincidence has also become smart around + + + align:start position:0% +coincidence has also become smart around +the same time and then Colossus which is + + align:start position:0% +the same time and then Colossus which is + + + align:start position:0% +the same time and then Colossus which is +the name of + + align:start position:0% +the name of + + + align:start position:0% +the name of +uh uh DF Jones uh computer + + align:start position:0% +uh uh DF Jones uh computer + + + align:start position:0% +uh uh DF Jones uh computer +forbin is the uh programmer who started + + align:start position:0% +forbin is the uh programmer who started + + + align:start position:0% +forbin is the uh programmer who started +the + + align:start position:0% +the + + + align:start position:0% +the +project the movie didn't use the word + + align:start position:0% +project the movie didn't use the word + + + align:start position:0% +project the movie didn't use the word +Colossus + + align:start position:0% + + + + align:start position:0% + +because it's probably not in the average + + align:start position:0% +because it's probably not in the average + + + align:start position:0% +because it's probably not in the average +person's + + align:start position:0% +person's + + + align:start position:0% +person's +vocabulary + + align:start position:0% +vocabulary + + + align:start position:0% +vocabulary +um anyway Colossus + + align:start position:0% +um anyway Colossus + + + align:start position:0% +um anyway Colossus +suddenly uh decides that it's not smart + + align:start position:0% +suddenly uh decides that it's not smart + + + align:start position:0% +suddenly uh decides that it's not smart +enough and so it uh orders uh + + align:start position:0% +enough and so it uh orders uh + + + align:start position:0% +enough and so it uh orders uh +Jones is an + + align:start position:0% +Jones is an + + + align:start position:0% +Jones is an +Englishman uh it + + align:start position:0% +Englishman uh it + + + align:start position:0% +Englishman uh it +orders + + align:start position:0% +orders + + + align:start position:0% +orders +uh the English government to clear off + + align:start position:0% +uh the English government to clear off + + + align:start position:0% +uh the English government to clear off +one of the Channel Islands and it's + + align:start position:0% +one of the Channel Islands and it's + + + align:start position:0% +one of the Channel Islands and it's +going to build a bigger copy of itself + + align:start position:0% +going to build a bigger copy of itself + + + align:start position:0% +going to build a bigger copy of itself +uh that'll be smarter and forbin asks + + align:start position:0% +uh that'll be smarter and forbin asks + + + align:start position:0% +uh that'll be smarter and forbin asks +why and Colossus says because I've been + + align:start position:0% +why and Colossus says because I've been + + + align:start position:0% +why and Colossus says because I've been +analyzing signals from extraterrestrial + + align:start position:0% +analyzing signals from extraterrestrial + + + align:start position:0% +analyzing signals from extraterrestrial +sources and there's a really smart + + align:start position:0% +sources and there's a really smart + + + align:start position:0% +sources and there's a really smart +machine coming here and it's going to + + align:start position:0% +machine coming here and it's going to + + + align:start position:0% +machine coming here and it's going to +kill all of us + + align:start position:0% +kill all of us + + + align:start position:0% +kill all of us +and so I have to uh build a machine + + align:start position:0% +and so I have to uh build a machine + + + align:start position:0% +and so I have to uh build a machine +that's a million times smarter than I am + + align:start position:0% +that's a million times smarter than I am + + + align:start position:0% +that's a million times smarter than I am +uh so that we'll be able to and so on so + + align:start position:0% +uh so that we'll be able to and so on so + + + align:start position:0% +uh so that we'll be able to and so on so +there's a typical scenario and the + + align:start position:0% +there's a typical scenario and the + + + align:start position:0% +there's a typical scenario and the +friendly AI people say uh how can we + + align:start position:0% +friendly AI people say uh how can we + + + align:start position:0% +friendly AI people say uh how can we +make sure that uh one of the AI projects + + align:start position:0% +make sure that uh one of the AI projects + + + align:start position:0% +make sure that uh one of the AI projects +won't suddenly take over the world and + + align:start position:0% +won't suddenly take over the world and + + + align:start position:0% +won't suddenly take over the world and +have some paranoid fantasy about why it + + align:start position:0% +have some paranoid fantasy about why it + + + align:start position:0% +have some paranoid fantasy about why it +has to kill all the people to make it + + align:start position:0% +has to kill all the people to make it + + + align:start position:0% +has to kill all the people to make it +safe for um the next generation of + + align:start position:0% +safe for um the next generation of + + + align:start position:0% +safe for um the next generation of +beings or science fiction writers are + + align:start position:0% +beings or science fiction writers are + + + align:start position:0% +beings or science fiction writers are +good at thinking so I'm asking you to + + align:start position:0% +good at thinking so I'm asking you to + + + align:start position:0% +good at thinking so I'm asking you to +think of other + + align:start position:0% +think of other + + + align:start position:0% +think of other +disasters um what's the worst disaster + + align:start position:0% +disasters um what's the worst disaster + + + align:start position:0% +disasters um what's the worst disaster +you can think of oh well we're next to + + align:start position:0% +you can think of oh well we're next to + + + align:start position:0% +you can think of oh well we're next to +worst don't I had one in mind I don't + + align:start position:0% +worst don't I had one in mind I don't + + + align:start position:0% +worst don't I had one in mind I don't +know if it's the worst case um there's + + align:start position:0% +know if it's the worst case um there's + + + align:start position:0% +know if it's the worst case um there's +there's actually a movie that's somewhat + + align:start position:0% +there's actually a movie that's somewhat + + + align:start position:0% +there's actually a movie that's somewhat +representative in this case have you + + align:start position:0% +representative in this case have you + + + align:start position:0% +representative in this case have you +seen the movie movie + + align:start position:0% +seen the movie movie + + + align:start position:0% +seen the movie movie +Idiocracy yes yeah with society and like + + align:start position:0% +Idiocracy yes yeah with society and like + + + align:start position:0% +Idiocracy yes yeah with society and like +that's what happens afterward yeah so it + + align:start position:0% +that's what happens afterward yeah so it + + + align:start position:0% +that's what happens afterward yeah so it +it sort of makes me wonder if there um + + align:start position:0% +it sort of makes me wonder if there um + + + align:start position:0% +it sort of makes me wonder if there um +you you see this to some extent now + + align:start position:0% +you you see this to some extent now + + + align:start position:0% +you you see this to some extent now +where people have systems that augment + + align:start position:0% +where people have systems that augment + + + align:start position:0% +where people have systems that augment +some of the things they used to do so + + align:start position:0% +some of the things they used to do so + + + align:start position:0% +some of the things they used to do so +much that they stop paying attention to + + align:start position:0% +much that they stop paying attention to + + + align:start position:0% +much that they stop paying attention to +or stop learning some of the stuff they + + align:start position:0% +or stop learning some of the stuff they + + + align:start position:0% +or stop learning some of the stuff they +used to and I can't remember that would + + align:start position:0% +used to and I can't remember that would + + + align:start position:0% +used to and I can't remember that would +be but you end up with a world where + + align:start position:0% +be but you end up with a world where + + + align:start position:0% +be but you end up with a world where +somebody they're starving and somebody + + align:start position:0% +somebody they're starving and somebody + + + align:start position:0% +somebody they're starving and somebody +says well I think there's something + + align:start position:0% +says well I think there's something + + + align:start position:0% +says well I think there's something +called seeds and if you plant them + + align:start position:0% +called seeds and if you plant them + + + align:start position:0% +called seeds and if you plant them +you exactly they're they're um watering + + align:start position:0% +you exactly they're they're um watering + + + align:start position:0% +you exactly they're they're um watering +their plants gatoring in one part + + align:start position:0% +their plants gatoring in one part + + + align:start position:0% +their plants gatoring in one part +because it has a l so um but I think but + + align:start position:0% +because it has a l so um but I think but + + + align:start position:0% +because it has a l so um but I think but +maybe one one problem is that you might + + align:start position:0% +maybe one one problem is that you might + + + align:start position:0% +maybe one one problem is that you might +start to see a big divide between people + + align:start position:0% +start to see a big divide between people + + + align:start position:0% +start to see a big divide between people +who um increasingly rely on technology + + align:start position:0% +who um increasingly rely on technology + + + align:start position:0% +who um increasingly rely on technology +to be able to learn nothing and people + + align:start position:0% +to be able to learn nothing and people + + + align:start position:0% +to be able to learn nothing and people +who take advantage of technology to + + align:start position:0% +who take advantage of technology to + + + align:start position:0% +who take advantage of technology to +learn a lot so maybe there will be this + + align:start position:0% +learn a lot so maybe there will be this + + + align:start position:0% +learn a lot so maybe there will be this +sort of divid feature of people who are + + align:start position:0% +sort of divid feature of people who are + + + align:start position:0% +sort of divid feature of people who are +know a lot and are very smart and + + align:start position:0% +know a lot and are very smart and + + + align:start position:0% +know a lot and are very smart and +intelligent people who just just don't + + align:start position:0% +intelligent people who just just don't + + + align:start position:0% +intelligent people who just just don't +to donate motivation to um and then + + align:start position:0% +to donate motivation to um and then + + + align:start position:0% +to donate motivation to um and then +becomes like who takes care of who and + + align:start position:0% +becomes like who takes care of who and + + + align:start position:0% +becomes like who takes care of who and +how's that work and do you try and get + + align:start position:0% +how's that work and do you try and get + + + align:start position:0% +how's that work and do you try and get +people to be more motivated or well + + align:start position:0% +people to be more motivated or well + + + align:start position:0% +people to be more motivated or well +there is this weird phenomenon + + align:start position:0% +there is this weird phenomenon + + + align:start position:0% +there is this weird phenomenon +that that could happen again which + + align:start position:0% +that that could happen again which + + + align:start position:0% +that that could happen again which +is a nice question of why wasn't why did + + align:start position:0% +is a nice question of why wasn't why did + + + align:start position:0% +is a nice question of why wasn't why did +science + + align:start position:0% +science + + + align:start position:0% +science +stop with + + align:start position:0% +stop with + + + align:start position:0% +stop with +Archimedes + + align:start position:0% +Archimedes + + + align:start position:0% +Archimedes +and + + align:start position:0% +and + + + align:start position:0% +and +um not pick up again till Galileo or so + + align:start position:0% +um not pick up again till Galileo or so + + + align:start position:0% +um not pick up again till Galileo or so +there's anybody have a theory + + align:start position:0% +there's anybody have a theory + + + align:start position:0% +there's anybody have a theory +why why did progress + + align:start position:0% +why why did progress + + + align:start position:0% +why why did progress +stop + + align:start position:0% +stop + + + align:start position:0% +stop +and one popular theory is that uh the + + align:start position:0% +and one popular theory is that uh the + + + align:start position:0% +and one popular theory is that uh the +rise of + + align:start position:0% +rise of + + + align:start position:0% +rise of +religions but of course as far as we + + align:start position:0% +religions but of course as far as we + + + align:start position:0% +religions but of course as far as we +know there were always religions how + + align:start position:0% +know there were always religions how + + + align:start position:0% +know there were always religions how +come Christianity + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +Islam uh + + align:start position:0% +Islam uh + + + align:start position:0% +Islam uh +had such a powerful effect for so much + + align:start position:0% +had such a powerful effect for so much + + + align:start position:0% +had such a powerful effect for so much +of the world for how long and is there a + + align:start position:0% +of the world for how long and is there a + + + align:start position:0% +of the world for how long and is there a +chance somebody could just invent + + align:start position:0% +chance somebody could just invent + + + align:start position:0% +chance somebody could just invent +another one tomorrow that would spread + + align:start position:0% +another one tomorrow that would spread + + + align:start position:0% +another one tomorrow that would spread +through and wipe out everything and how + + align:start position:0% +through and wipe out everything and how + + + align:start position:0% +through and wipe out everything and how +do you detect it and uh stop it before + + align:start position:0% +do you detect it and uh stop it before + + + align:start position:0% +do you detect it and uh stop it before +it starts to + + align:start position:0% + + + + align:start position:0% + +spread but what so that's that's + + align:start position:0% +spread but what so that's that's + + + align:start position:0% +spread but what so that's that's +something that could happen it's + + align:start position:0% +something that could happen it's + + + align:start position:0% +something that could happen it's +happened + + align:start position:0% + + + + align:start position:0% + +before uh + + align:start position:0% + + + + align:start position:0% + +or suppose somebody invented a new kind + + align:start position:0% +or suppose somebody invented a new kind + + + align:start position:0% +or suppose somebody invented a new kind +of not quite sound logical argument that + + align:start position:0% +of not quite sound logical argument that + + + align:start position:0% +of not quite sound logical argument that +convinces + + align:start position:0% +convinces + + + align:start position:0% +convinces +everyone which would be almost the same + + align:start position:0% +everyone which would be almost the same + + + align:start position:0% +everyone which would be almost the same +thing I + + align:start position:0% +thing I + + + align:start position:0% +thing I +suppose um have we been just lucky that + + align:start position:0% +suppose um have we been just lucky that + + + align:start position:0% +suppose um have we been just lucky that +nobody thought of a false argument that + + align:start position:0% +nobody thought of a false argument that + + + align:start position:0% +nobody thought of a false argument that +you can use to convince anybody of + + align:start position:0% +you can use to convince anybody of + + + align:start position:0% +you can use to convince anybody of +anything + + align:start position:0% + + + + align:start position:0% + +well maybe we have protection mechanisms + + align:start position:0% +well maybe we have protection mechanisms + + + align:start position:0% +well maybe we have protection mechanisms +against something like that + + align:start position:0% +against something like that + + + align:start position:0% +against something like that +happening and as for the first St you + + align:start position:0% +happening and as for the first St you + + + align:start position:0% +happening and as for the first St you +mean it used to happen and the few + + align:start position:0% +mean it used to happen and the few + + + align:start position:0% +mean it used to happen and the few +people developed evolved a a way to + + align:start position:0% +people developed evolved a a way to + + + align:start position:0% +people developed evolved a a way to +reject it and now it's so common that we + + align:start position:0% +reject it and now it's so common that we + + + align:start position:0% +reject it and now it's so common that we +don't even know about + + align:start position:0% +don't even know about + + + align:start position:0% +don't even know about +it I don't know can you imagine what is + + align:start position:0% +it I don't know can you imagine what is + + + align:start position:0% +it I don't know can you imagine what is +it like if something is very + + align:start position:0% +it like if something is very + + + align:start position:0% +it like if something is very +convincing uh you get this feeling well + + align:start position:0% +convincing uh you get this feeling well + + + align:start position:0% +convincing uh you get this feeling well +that promises too much I'll ignore it + + align:start position:0% +that promises too much I'll ignore it + + + align:start position:0% +that promises too much I'll ignore it +that that could + + align:start position:0% + + + + align:start position:0% + +be that's why we turn down when thesis + + align:start position:0% +be that's why we turn down when thesis + + + align:start position:0% +be that's why we turn down when thesis +proposals get + + align:start position:0% +proposals get + + + align:start position:0% +proposals get +rejected sometimes it's because they + + align:start position:0% +rejected sometimes it's because they + + + align:start position:0% +rejected sometimes it's because they +don't promise enough but usually it's + + align:start position:0% +don't promise enough but usually it's + + + align:start position:0% +don't promise enough but usually it's +because they're going to solve + + align:start position:0% +because they're going to solve + + + align:start position:0% +because they're going to solve +everything and then the thesis advisor + + align:start position:0% +everything and then the thesis advisor + + + align:start position:0% +everything and then the thesis advisor +says well here's this little problem can + + align:start position:0% +says well here's this little problem can + + + align:start position:0% +says well here's this little problem can +you solve that and + + align:start position:0% +you solve that and + + + align:start position:0% +you solve that and +the student goes away and if we're lucky + + align:start position:0% +the student goes away and if we're lucky + + + align:start position:0% +the student goes away and if we're lucky +they come back with a something that'll + + align:start position:0% +they come back with a something that'll + + + align:start position:0% +they come back with a something that'll +solve that instead of + + align:start position:0% + + + + align:start position:0% + +everything I think it's all happening + + align:start position:0% +everything I think it's all happening + + + align:start position:0% +everything I think it's all happening +again right now essentially when the + + align:start position:0% +again right now essentially when the + + + align:start position:0% +again right now essentially when the +economy collapses then people have to + + align:start position:0% +economy collapses then people have to + + + align:start position:0% +economy collapses then people have to +worry about other things so their + + align:start position:0% +worry about other things so their + + + align:start position:0% +worry about other things so their +attention is elsewhere the visigoth at + + align:start position:0% +attention is elsewhere the visigoth at + + + align:start position:0% +attention is elsewhere the visigoth at +the gate or + + align:start position:0% +the gate or + + + align:start position:0% +the gate or +eating um look at what's happening now + + align:start position:0% +eating um look at what's happening now + + + align:start position:0% +eating um look at what's happening now +with the economies there are theories + + align:start position:0% +with the economies there are theories + + + align:start position:0% +with the economies there are theories +that are proven to be pretty bad and + + align:start position:0% +that are proven to be pretty bad and + + + align:start position:0% +that are proven to be pretty bad and +they're bringing everything down + + align:start position:0% +they're bringing everything down + + + align:start position:0% +they're bringing everything down +you think it'll be followed by more + + align:start position:0% +you think it'll be followed by more + + + align:start position:0% +you think it'll be followed by more +theories + + align:start position:0% +theories + + + align:start position:0% +theories +or practical action let's + + align:start position:0% +or practical action let's + + + align:start position:0% +or practical action let's +see is this one worse than the + + align:start position:0% +see is this one worse than the + + + align:start position:0% +see is this one worse than the +19 29 + + align:start position:0% +19 29 + + + align:start position:0% +19 29 +depression that got most of the world + + align:start position:0% +depression that got most of the world + + + align:start position:0% +depression that got most of the world +didn't it it did not + + align:start position:0% +didn't it it did not + + + align:start position:0% +didn't it it did not +yet it's not quite there no but it's + + align:start position:0% +yet it's not quite there no but it's + + + align:start position:0% +yet it's not quite there no but it's +much because Argentina and a few other + + align:start position:0% +much because Argentina and a few other + + + align:start position:0% +much because Argentina and a few other +countries don't seem to have collapsed + + align:start position:0% +countries don't seem to have collapsed + + + align:start position:0% +countries don't seem to have collapsed +yet + + align:start position:0% +yet + + + align:start position:0% +yet +back then we had the gold standard now + + align:start position:0% +back then we had the gold standard now + + + align:start position:0% +back then we had the gold standard now +we only have the paper money standard + + align:start position:0% +we only have the paper money standard + + + align:start position:0% +we only have the paper money standard +so they're Shoring up the walls but when + + align:start position:0% +so they're Shoring up the walls but when + + + align:start position:0% +so they're Shoring up the walls but when +it falls it's going to be very bad + + align:start position:0% +it falls it's going to be very bad + + + align:start position:0% +it falls it's going to be very bad +indeed didn't gold hit $3,000 + + align:start position:0% + + + + align:start position:0% + +recently it was over + + align:start position:0% +recently it was over + + + align:start position:0% +recently it was over +2,000 yeah when people start not + + align:start position:0% +2,000 yeah when people start not + + + align:start position:0% +2,000 yeah when people start not +trusting the currency anymore like the + + align:start position:0% +trusting the currency anymore like the + + + align:start position:0% +trusting the currency anymore like the +main currency + + align:start position:0% +main currency + + + align:start position:0% +main currency +because like the currency is just a and + + align:start position:0% +because like the currency is just a and + + + align:start position:0% +because like the currency is just a and +so if you don't trust any more like the + + align:start position:0% +so if you don't trust any more like the + + + align:start position:0% +so if you don't trust any more like the +people that bring the currency then we + + align:start position:0% +people that bring the currency then we + + + align:start position:0% +people that bring the currency then we +can have like this is like countries + + align:start position:0% +can have like this is like countries + + + align:start position:0% +can have like this is like countries +will not be as organized as + + align:start position:0% +will not be as organized as + + + align:start position:0% +will not be as organized as +before because why should I be poor if + + align:start position:0% +before because why should I be poor if + + + align:start position:0% +before because why should I be poor if +there is well of course that's why + + align:start position:0% +there is well of course that's why + + + align:start position:0% +there is well of course that's why +people are going to gold + + align:start position:0% +people are going to gold + + + align:start position:0% +people are going to gold +is I'm not sure they're going to Gold I + + align:start position:0% +is I'm not sure they're going to Gold I + + + align:start position:0% +is I'm not sure they're going to Gold I +for security I think they're just trying + + align:start position:0% +for security I think they're just trying + + + align:start position:0% +for security I think they're just trying +to make more money but who + + align:start position:0% + + + + align:start position:0% + +knows well how do you fix an economic + + align:start position:0% + + + + align:start position:0% + +depression I believe World War II + + align:start position:0% +depression I believe World War II + + + align:start position:0% +depression I believe World War II +helped that may be the solution + + align:start position:0% +helped that may be the solution + + + align:start position:0% +helped that may be the solution +again so I guess puing it is a disaster + + align:start position:0% +again so I guess puing it is a disaster + + + align:start position:0% +again so I guess puing it is a disaster +I would say + + align:start position:0% +I would say + + + align:start position:0% +I would say +that the collective Archive of human + + align:start position:0% +that the collective Archive of human + + + align:start position:0% +that the collective Archive of human +information and knowledge become so + + align:start position:0% +information and knowledge become so + + + align:start position:0% +information and knowledge become so +polluted with that you can no + + align:start position:0% +polluted with that you can no + + + align:start position:0% +polluted with that you can no +longer find actual useful fact + + align:start position:0% +longer find actual useful fact + + + align:start position:0% +longer find actual useful fact +among the + + align:start position:0% + + + + align:start position:0% + +propaganda well then there + + align:start position:0% + + + + align:start position:0% + +are pretty soon high school students + + align:start position:0% +are pretty soon high school students + + + align:start position:0% +are pretty soon high school students +will be able to make new + + align:start position:0% +will be able to make new + + + align:start position:0% +will be able to make new +genomes they can do so there's that's a + + align:start position:0% +genomes they can do so there's that's a + + + align:start position:0% +genomes they can do so there's that's a +typical technological + + align:start position:0% +typical technological + + + align:start position:0% +typical technological +disaster that uh did you read the paper + + align:start position:0% +disaster that uh did you read the paper + + + align:start position:0% +disaster that uh did you read the paper +last week that some lab made + + align:start position:0% + + + + align:start position:0% + +uh the best small poox virus + + align:start position:0% +uh the best small poox virus + + + align:start position:0% +uh the best small poox virus +ever yeah but you can have agencies that + + align:start position:0% +ever yeah but you can have agencies that + + + align:start position:0% +ever yeah but you can have agencies that +control that I mean there are many kind + + align:start position:0% +control that I mean there are many kind + + + align:start position:0% +control that I mean there are many kind +of uh weapons that you can create at + + align:start position:0% +of uh weapons that you can create at + + + align:start position:0% +of uh weapons that you can create at +home is the fact that you can create + + align:start position:0% +home is the fact that you can create + + + align:start position:0% +home is the fact that you can create +them doesn't mean that people are going + + align:start position:0% +them doesn't mean that people are going + + + align:start position:0% +them doesn't mean that people are going +to grade them and you just need to but + + align:start position:0% +to grade them and you just need to but + + + align:start position:0% +to grade them and you just need to but +if you have 7 billion people and you + + align:start position:0% +if you have 7 billion people and you + + + align:start position:0% +if you have 7 billion people and you +only need one to create + + align:start position:0% +only need one to create + + + align:start position:0% +only need one to create +the the small pox that kills everybody + + align:start position:0% +the the small pox that kills everybody + + + align:start position:0% +the the small pox that kills everybody +you don't give the resources to it + + align:start position:0% +you don't give the resources to it + + + align:start position:0% +you don't give the resources to it +doesn't take + + align:start position:0% +doesn't take + + + align:start position:0% +doesn't take +any these machines will be $1,000 + + align:start position:0% +any these machines will be $1,000 + + + align:start position:0% +any these machines will be $1,000 +soon how much does + + align:start position:0% +soon how much does + + + align:start position:0% +soon how much does +a sequence well you have to buy the + + align:start position:0% +a sequence well you have to buy the + + + align:start position:0% +a sequence well you have to buy the +uh the uh DNA + + align:start position:0% + + + + align:start position:0% + +bottles might cost several dollars to to + + align:start position:0% +bottles might cost several dollars to to + + + align:start position:0% +bottles might cost several dollars to to +make + + align:start position:0% +make + + + align:start position:0% +make +uh the ultimate virus why would people + + align:start position:0% +uh the ultimate virus why would people + + + align:start position:0% +uh the ultimate virus why would people +sell these machines like they + + align:start position:0% +sell these machines like they + + + align:start position:0% +sell these machines like they +are they they've just gotten cheap + + align:start position:0% +are they they've just gotten cheap + + + align:start position:0% +are they they've just gotten cheap +enough that you can buy + + align:start position:0% +enough that you can buy + + + align:start position:0% +enough that you can buy +one we're just on the they used to cost + + align:start position:0% +one we're just on the they used to cost + + + align:start position:0% +one we're just on the they used to cost +a million + + align:start position:0% +a million + + + align:start position:0% +a million +dollars but now there's a place down on + + align:start position:0% +dollars but now there's a place down on + + + align:start position:0% +dollars but now there's a place down on +uh what's the street P after Vasser + + align:start position:0% +uh what's the street P after Vasser + + + align:start position:0% +uh what's the street P after Vasser +Street Al Alban stre company there that + + align:start position:0% +Street Al Alban stre company there that + + + align:start position:0% +Street Al Alban stre company there that +has sequences which are only + + align:start position:0% +has sequences which are only + + + align:start position:0% +has sequences which are only +$50,000 can we control like uh the + + align:start position:0% +$50,000 can we control like uh the + + + align:start position:0% +$50,000 can we control like uh the +spread of a disease like for example the + + align:start position:0% +spread of a disease like for example the + + + align:start position:0% +spread of a disease like for example the +swine food we they don't know how to + + align:start position:0% +swine food we they don't know how to + + + align:start position:0% +swine food we they don't know how to +stop AIDS after 30 years of well-funded + + align:start position:0% +stop AIDS after 30 years of well-funded + + + align:start position:0% +stop AIDS after 30 years of well-funded +research yeah but we still have a lot of + + align:start position:0% +research yeah but we still have a lot of + + + align:start position:0% +research yeah but we still have a lot of +people so if like one billion people die + + align:start position:0% +people so if like one billion people die + + + align:start position:0% +people so if like one billion people die +just one + + align:start position:0% +just one + + + align:start position:0% +just one +bilon I mean it's you see it might kill + + align:start position:0% +bilon I mean it's you see it might kill + + + align:start position:0% +bilon I mean it's you see it might kill +everybody in a year and uh it takes 5 + + align:start position:0% +everybody in a year and uh it takes 5 + + + align:start position:0% +everybody in a year and uh it takes 5 +years to make a new drug so it's a sort + + align:start position:0% + + + + align:start position:0% + +of I don't think there's an answer to + + align:start position:0% +of I don't think there's an answer to + + + align:start position:0% +of I don't think there's an answer to +that one right now except that + + align:start position:0% +that one right now except that + + + align:start position:0% +that one right now except that +uh right now you get a prize if you + + align:start position:0% +uh right now you get a prize if you + + + align:start position:0% +uh right now you get a prize if you +synthesize + + align:start position:0% +synthesize + + + align:start position:0% +synthesize +something Tom Knight had a + + align:start position:0% + + + + align:start position:0% + +he had some high school students make + + align:start position:0% +he had some high school students make + + + align:start position:0% +he had some high school students make +interesting things uh but lots of there + + align:start position:0% +interesting things uh but lots of there + + + align:start position:0% +interesting things uh but lots of there +are lots of projects like that now where + + align:start position:0% +are lots of projects like that now where + + + align:start position:0% +are lots of projects like that now where +people in biology courses uh can design + + align:start position:0% +people in biology courses uh can design + + + align:start position:0% +people in biology courses uh can design +something + + align:start position:0% +something + + + align:start position:0% +something +and get it onto a gene making + + align:start position:0% +and get it onto a gene making + + + align:start position:0% +and get it onto a gene making +machine so that's a serious problem yeah + + align:start position:0% +machine so that's a serious problem yeah + + + align:start position:0% +machine so that's a serious problem yeah +so we have like these big problems and + + align:start position:0% +so we have like these big problems and + + + align:start position:0% +so we have like these big problems and +we have other several ones like we are + + align:start position:0% +we have other several ones like we are + + + align:start position:0% +we have other several ones like we are +not very smart as individuals and also + + align:start position:0% +not very smart as individuals and also + + + align:start position:0% +not very smart as individuals and also +we can't communicate very well like very + + align:start position:0% +we can't communicate very well like very + + + align:start position:0% +we can't communicate very well like very +fast and probably we need machines that + + align:start position:0% +fast and probably we need machines that + + + align:start position:0% +fast and probably we need machines that +can uh solve these problems for us you + + align:start position:0% +can uh solve these problems for us you + + + align:start position:0% +can uh solve these problems for us you +believe that uh Brook's approach of like + + align:start position:0% +believe that uh Brook's approach of like + + + align:start position:0% +believe that uh Brook's approach of like +soing uh creating robots like + + align:start position:0% +soing uh creating robots like + + + align:start position:0% +soing uh creating robots like +intelligent robots is good and uh how is + + align:start position:0% +intelligent robots is good and uh how is + + + align:start position:0% +intelligent robots is good and uh how is +it compareed to winstone's approach like + + align:start position:0% +it compareed to winstone's approach like + + + align:start position:0% +it compareed to winstone's approach like +he's doing more a research and trying to + + align:start position:0% +he's doing more a research and trying to + + + align:start position:0% +he's doing more a research and trying to +create something I believe more similar + + align:start position:0% +create something I believe more similar + + + align:start position:0% +create something I believe more similar +to uh a human being than like human + + align:start position:0% +to uh a human being than like human + + + align:start position:0% +to uh a human being than like human +intelligent well he's trying to make a a + + align:start position:0% +intelligent well he's trying to make a a + + + align:start position:0% +intelligent well he's trying to make a a +machine that has can do common sense + + align:start position:0% +machine that has can do common sense + + + align:start position:0% +machine that has can do common sense +reasoning what we call Common Sense + + align:start position:0% +reasoning what we call Common Sense + + + align:start position:0% +reasoning what we call Common Sense +reasoning yeah but do you think that's + + align:start position:0% +reasoning yeah but do you think that's + + + align:start position:0% +reasoning yeah but do you think that's +uh like that's better because we will + + align:start position:0% +uh like that's better because we will + + + align:start position:0% +uh like that's better because we will +solve problems like the problem of like + + align:start position:0% +solve problems like the problem of like + + + align:start position:0% +solve problems like the problem of like +having people that produce uh viruses + + align:start position:0% +having people that produce uh viruses + + + align:start position:0% +having people that produce uh viruses +very cheap then like these robots can + + align:start position:0% +very cheap then like these robots can + + + align:start position:0% +very cheap then like these robots can +solve these problems for us probably if + + align:start position:0% +solve these problems for us probably if + + + align:start position:0% +solve these problems for us probably if +they're smarter than us if they have + + align:start position:0% +they're smarter than us if they have + + + align:start position:0% +they're smarter than us if they have +enough processors or do you think that's + + align:start position:0% +enough processors or do you think that's + + + align:start position:0% +enough processors or do you think that's +better than creating like for example + + align:start position:0% +better than creating like for example + + + align:start position:0% +better than creating like for example +Brooks is creating robots that solve + + align:start position:0% +Brooks is creating robots that solve + + + align:start position:0% +Brooks is creating robots that solve +other + + align:start position:0% +other + + + align:start position:0% +other +problems well the question that's a + + align:start position:0% +problems well the question that's a + + + align:start position:0% +problems well the question that's a +question of whether + + align:start position:0% + + + + align:start position:0% + +uh can you make a machine that's very + + align:start position:0% +uh can you make a machine that's very + + + align:start position:0% +uh can you make a machine that's very +good at some + + align:start position:0% + + + + align:start position:0% + +I mean there things like mathematical + + align:start position:0% +I mean there things like mathematical + + + align:start position:0% +I mean there things like mathematical +problems like uh factoring numbers and + + align:start position:0% +problems like uh factoring numbers and + + + align:start position:0% +problems like uh factoring numbers and +you could make a + + align:start position:0% +you could make a + + + align:start position:0% +you could make a +supercomputer nobody has but uh you + + align:start position:0% +supercomputer nobody has but uh you + + + align:start position:0% +supercomputer nobody has but uh you +could imagine working on that problem + + align:start position:0% +could imagine working on that problem + + + align:start position:0% +could imagine working on that problem +and eventually uh finding some way to + + align:start position:0% +and eventually uh finding some way to + + + align:start position:0% +and eventually uh finding some way to +make a computer uh Factor very large + + align:start position:0% +make a computer uh Factor very large + + + align:start position:0% +make a computer uh Factor very large +numbers quickly now nobody has proved uh + + align:start position:0% +numbers quickly now nobody has proved uh + + + align:start position:0% +numbers quickly now nobody has proved uh +that that's a uh NP problem as far as it + + align:start position:0% +that that's a uh NP problem as far as it + + + align:start position:0% +that that's a uh NP problem as far as it +does anybody + + align:start position:0% +does anybody + + + align:start position:0% +does anybody +know is factoring an NP hard + + align:start position:0% +know is factoring an NP hard + + + align:start position:0% +know is factoring an NP hard +problem no it has not been shown to be n + + align:start position:0% +problem no it has not been shown to be n + + + align:start position:0% +problem no it has not been shown to be n +hard what it has not been shown to be n + + align:start position:0% +hard what it has not been shown to be n + + + align:start position:0% +hard what it has not been shown to be n +heart recently there's + + align:start position:0% +heart recently there's + + + align:start position:0% +heart recently there's +A2 that factory shows + + align:start position:0% + + + + align:start position:0% + +poory like + + align:start position:0% +poory like + + + align:start position:0% +poory like +recently it's been shown to be + + align:start position:0% +recently it's been shown to be + + + align:start position:0% +recently it's been shown to be +polinomial yeah that's nice or not I + + align:start position:0% +polinomial yeah that's nice or not I + + + align:start position:0% +polinomial yeah that's nice or not I +don't know + + align:start position:0% + + + + align:start position:0% + +I haven't kept + + align:start position:0% + + + + align:start position:0% + +track oh no that's if something's oh + + align:start position:0% +track oh no that's if something's oh + + + align:start position:0% +track oh no that's if something's oh +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah yeah I think um right now is they + + align:start position:0% +yeah yeah I think um right now is they + + + align:start position:0% +yeah yeah I think um right now is they +don't think it's any hard but if it + + align:start position:0% +don't think it's any hard but if it + + + align:start position:0% +don't think it's any hard but if it +turns out to be polom with um like the + + align:start position:0% +turns out to be polom with um like the + + + align:start position:0% +turns out to be polom with um like the +entire hierarchy kind of collapses I + + align:start position:0% +entire hierarchy kind of collapses I + + + align:start position:0% +entire hierarchy kind of collapses I +think that's what + + align:start position:0% +think that's what + + + align:start position:0% +think that's what +happens but yeah + + align:start position:0% +happens but yeah + + + align:start position:0% +happens but yeah +We There are known to be uh problems + + align:start position:0% +We There are known to be uh problems + + + align:start position:0% +We There are known to be uh problems +that are not polom + + align:start position:0% +that are not polom + + + align:start position:0% +that are not polom +and but + + align:start position:0% +and but + + + align:start position:0% +and but +uh what's the standard NP problem + + align:start position:0% +uh what's the standard NP problem + + + align:start position:0% +uh what's the standard NP problem +M which + + align:start position:0% + + + + align:start position:0% + +one Boolean + + align:start position:0% +one Boolean + + + align:start position:0% +one Boolean +satisfiability uhuh uh freedb fredberg + + align:start position:0% +satisfiability uhuh uh freedb fredberg + + + align:start position:0% +satisfiability uhuh uh freedb fredberg +and muchnik had a + + align:start position:0% +and muchnik had a + + + align:start position:0% +and muchnik had a +complicated uh process between where two + + align:start position:0% +complicated uh process between where two + + + align:start position:0% +complicated uh process between where two +touring machines are passing data to + + align:start position:0% +touring machines are passing data to + + + align:start position:0% +touring machines are passing data to +each other and uh that was not they + + align:start position:0% +each other and uh that was not they + + + align:start position:0% +each other and uh that was not they +proved that that was NP but simpler + + align:start position:0% +proved that that was NP but simpler + + + align:start position:0% +proved that that was NP but simpler +than uh than the standard one so there + + align:start position:0% +than uh than the standard one so there + + + align:start position:0% +than uh than the standard one so there +are things on the hierarchy that that + + align:start position:0% +are things on the hierarchy that that + + + align:start position:0% +are things on the hierarchy that that +are lower + + align:start position:0% +are lower + + + align:start position:0% +are lower +than um the combinatorial standard ones + + align:start position:0% +than um the combinatorial standard ones + + + align:start position:0% +than um the combinatorial standard ones +but + + align:start position:0% +but + + + align:start position:0% +but +anyway + + align:start position:0% +anyway + + + align:start position:0% +anyway +um but the question is can can you make + + align:start position:0% +um but the question is can can you make + + + align:start position:0% +um but the question is can can you make +a machine that can understand + + align:start position:0% +a machine that can understand + + + align:start position:0% +a machine that can understand +Shakespeare plays and but that leaves no + + align:start position:0% +Shakespeare plays and but that leaves no + + + align:start position:0% +Shakespeare plays and but that leaves no +possibility that 10 minutes later uh it + + align:start position:0% +possibility that 10 minutes later uh it + + + align:start position:0% +possibility that 10 minutes later uh it +can do unthinkably dangerous things and + + align:start position:0% +can do unthinkably dangerous things and + + + align:start position:0% +can do unthinkably dangerous things and +I think the answer is no + + align:start position:0% +I think the answer is no + + + align:start position:0% +I think the answer is no +nobody uh it's hard to see any + + align:start position:0% +nobody uh it's hard to see any + + + align:start position:0% +nobody uh it's hard to see any +difference between literary thinking and + + align:start position:0% +difference between literary thinking and + + + align:start position:0% +difference between literary thinking and +scientific + + align:start position:0% + + + + align:start position:0% + +thinking I mean a novel is like a very + + align:start position:0% +thinking I mean a novel is like a very + + + align:start position:0% +thinking I mean a novel is like a very +long proof of something with a few + + align:start position:0% +long proof of something with a few + + + align:start position:0% +long proof of something with a few +bugs I don't I don't see General + + align:start position:0% +bugs I don't I don't see General + + + align:start position:0% +bugs I don't I don't see General +literature as any different from + + align:start position:0% +literature as any different from + + + align:start position:0% +literature as any different from +technical literature except the + + align:start position:0% +technical literature except the + + + align:start position:0% +technical literature except the +Criterion for + + align:start position:0% +Criterion for + + + align:start position:0% +Criterion for +Success uh is much + + align:start position:0% + + + + align:start position:0% + +lower I made a whole list of things + + align:start position:0% +lower I made a whole list of things + + + align:start position:0% +lower I made a whole list of things +but I don't know if that thing works + + align:start position:0% + + + + align:start position:0% + +wake + + align:start position:0% + + + + align:start position:0% + +up well my screen is + + align:start position:0% +up well my screen is + + + align:start position:0% +up well my screen is +blue it may + + align:start position:0% + + + + align:start position:0% + +actually is it actually + + align:start position:0% + + + + align:start position:0% + +working oh I could + + align:start position:0% + + + + align:start position:0% + +is there any point in my turning on the + + align:start position:0% +is there any point in my turning on the + + + align:start position:0% +is there any point in my turning on the +control + + align:start position:0% + + + + align:start position:0% + +panel it's not showing + + align:start position:0% +panel it's not showing + + + align:start position:0% +panel it's not showing +here oh well maybe the connector's loose + + align:start position:0% + + + + align:start position:0% + +or oh well + + align:start position:0% + + + + align:start position:0% + +it doesn't have any + + align:start position:0% + + + + align:start position:0% + +diagrams I mean we already have problems + + align:start position:0% +diagrams I mean we already have problems + + + align:start position:0% +diagrams I mean we already have problems +that look pretty serious like + + align:start position:0% +that look pretty serious like + + + align:start position:0% +that look pretty serious like +uh when people started worrying about + + align:start position:0% +uh when people started worrying about + + + align:start position:0% +uh when people started worrying about +population a generation ago uh they + + align:start position:0% +population a generation ago uh they + + + align:start position:0% +population a generation ago uh they +it was carefully explained that uh as + + align:start position:0% +it was carefully explained that uh as + + + align:start position:0% +it was carefully explained that uh as +soon as people achieved a + + align:start position:0% +soon as people achieved a + + + align:start position:0% +soon as people achieved a +uh substantial income then the number of + + align:start position:0% +uh substantial income then the number of + + + align:start position:0% +uh substantial income then the number of +children per family would + + align:start position:0% +children per family would + + + align:start position:0% +children per family would +disappear and I don't know if that rumor + + align:start position:0% +disappear and I don't know if that rumor + + + align:start position:0% +disappear and I don't know if that rumor +is + + align:start position:0% +is + + + align:start position:0% +is +still how many of you believe that as + + align:start position:0% +still how many of you believe that as + + + align:start position:0% +still how many of you believe that as +the standard of living goes up the + + align:start position:0% +the standard of living goes up the + + + align:start position:0% +the standard of living goes up the +population + + align:start position:0% + + + + align:start position:0% + +declines seems to be true in some + + align:start position:0% +declines seems to be true in some + + + align:start position:0% +declines seems to be true in some +countries + + align:start position:0% +countries + + + align:start position:0% +countries +but it only takes one + + align:start position:0% + + + + align:start position:0% + +exception yeah I always thought it was + + align:start position:0% +exception yeah I always thought it was + + + align:start position:0% +exception yeah I always thought it was +more correlated to um education about + + align:start position:0% +more correlated to um education about + + + align:start position:0% +more correlated to um education about +like um methods for preventing well if + + align:start position:0% +like um methods for preventing well if + + + align:start position:0% +like um methods for preventing well if +you don't take get married till you get + + align:start position:0% +you don't take get married till you get + + + align:start position:0% +you don't take get married till you get +your PhD all right and if we manage to + + align:start position:0% +your PhD all right and if we manage to + + + align:start position:0% +your PhD all right and if we manage to +make the PHD take 15 + + align:start position:0% +make the PHD take 15 + + + align:start position:0% +make the PHD take 15 +years + + align:start position:0% + + + + align:start position:0% + +uh has anybody propos + + align:start position:0% + + + + align:start position:0% + +that that would and I I feel like part + + align:start position:0% +that that would and I I feel like part + + + align:start position:0% +that that would and I I feel like part +of it with developing countries where + + align:start position:0% +of it with developing countries where + + + align:start position:0% +of it with developing countries where +standards of living are low um one of + + align:start position:0% +standards of living are low um one of + + + align:start position:0% +standards of living are low um one of +the reasons why population is so high is + + align:start position:0% +the reasons why population is so high is + + + align:start position:0% +the reasons why population is so high is +that like they don't really have good + + align:start position:0% +that like they don't really have good + + + align:start position:0% +that like they don't really have good +methods of birth control right it's like + + align:start position:0% +methods of birth control right it's like + + + align:start position:0% +methods of birth control right it's like +not necessarily that want to be having + + align:start position:0% +not necessarily that want to be having + + + align:start position:0% +not necessarily that want to be having +so many kids but it's just that like + + align:start position:0% +so many kids but it's just that like + + + align:start position:0% +so many kids but it's just that like +they they have less fewer methods of + + align:start position:0% +they they have less fewer methods of + + + align:start position:0% +they they have less fewer methods of +preventing it there's also if you have + + align:start position:0% +preventing it there's also if you have + + + align:start position:0% +preventing it there's also if you have +seven kids and four of them die then you + + align:start position:0% +seven kids and four of them die then you + + + align:start position:0% +seven kids and four of them die then you +say oh this is what am I going to do + + align:start position:0% +say oh this is what am I going to do + + + align:start position:0% +say oh this is what am I going to do +when I retire and so you quickly have + + align:start position:0% +when I retire and so you quickly have + + + align:start position:0% +when I retire and so you quickly have +four more if you can so right so I guess + + align:start position:0% +four more if you can so right so I guess + + + align:start position:0% +four more if you can so right so I guess +they are accounting for the fact that + + align:start position:0% +they are accounting for the fact that + + + align:start position:0% +they are accounting for the fact that +like a lot of kids are likely to die in + + align:start position:0% +like a lot of kids are likely to die in + + + align:start position:0% +like a lot of kids are likely to die in +childhood anyway but once you have + + align:start position:0% +childhood anyway but once you have + + + align:start position:0% +childhood anyway but once you have +robots then we won't need kids + + align:start position:0% +robots then we won't need kids + + + align:start position:0% +robots then we won't need kids +anymore like in + + align:start position:0% +anymore like in + + + align:start position:0% +anymore like in +Japan what's happening in Japan the + + align:start position:0% +Japan what's happening in Japan the + + + align:start position:0% +Japan what's happening in Japan the +birth rate is way down well I think in + + align:start position:0% +birth rate is way down well I think in + + + align:start position:0% +birth rate is way down well I think in +Japan they have a problem with an aging + + align:start position:0% +Japan they have a problem with an aging + + + align:start position:0% +Japan they have a problem with an aging +population and enough young people to + + align:start position:0% +population and enough young people to + + + align:start position:0% +population and enough young people to +take care of them so I think they're + + align:start position:0% +take care of them so I think they're + + + align:start position:0% +take care of them so I think they're +investing a lot in uh like humanoid + + align:start position:0% +investing a lot in uh like humanoid + + + align:start position:0% +investing a lot in uh like humanoid +robots or robots that can take care of + + align:start position:0% +robots or robots that can take care of + + + align:start position:0% +robots or robots that can take care of +old + + align:start position:0% +old + + + align:start position:0% +old +people yes I see the Honda robot has + + align:start position:0% +people yes I see the Honda robot has + + + align:start position:0% +people yes I see the Honda robot has +gotten a little smaller and doesn't fall + + align:start position:0% +gotten a little smaller and doesn't fall + + + align:start position:0% +gotten a little smaller and doesn't fall +over quite so + + align:start position:0% +over quite so + + + align:start position:0% +over quite so +quickly have you seen it dance it's + + align:start position:0% +quickly have you seen it dance it's + + + align:start position:0% +quickly have you seen it dance it's +pretty + + align:start position:0% +pretty + + + align:start position:0% +pretty +C there's something wrong with its + + align:start position:0% +C there's something wrong with its + + + align:start position:0% +C there's something wrong with its +posture + + align:start position:0% + + + + align:start position:0% + +though apparently it doesn't know it + + align:start position:0% +though apparently it doesn't know it + + + align:start position:0% +though apparently it doesn't know it +can't it can't straighten its legs + + align:start position:0% +can't it can't straighten its legs + + + align:start position:0% +can't it can't straighten its legs +without falling over so it's always it's + + align:start position:0% +without falling over so it's always it's + + + align:start position:0% +without falling over so it's always it's +it walks + + align:start position:0% +it walks + + + align:start position:0% +it walks +in anybody know why maybe it doesn't + + align:start position:0% +in anybody know why maybe it doesn't + + + align:start position:0% +in anybody know why maybe it doesn't +have + + align:start position:0% +have + + + align:start position:0% +have +any maybe it doesn't have any spinal + + align:start position:0% + + + + align:start position:0% + +joints + + align:start position:0% +joints + + + align:start position:0% +joints +anyway cars can't walk + + align:start position:0% + + + + align:start position:0% + +yet so what other disasters do we + + align:start position:0% +yet so what other disasters do we + + + align:start position:0% +yet so what other disasters do we +there's always global + + align:start position:0% + + + + align:start position:0% + +warming that looks hard to + + align:start position:0% +warming that looks hard to + + + align:start position:0% +warming that looks hard to +fix + + align:start position:0% + + + + align:start position:0% + +yeah I have a friend named Russell sites + + align:start position:0% +yeah I have a friend named Russell sites + + + align:start position:0% +yeah I have a friend named Russell sites +who appears to have a good solution to + + align:start position:0% +who appears to have a good solution to + + + align:start position:0% +who appears to have a good solution to +it which + + align:start position:0% +it which + + + align:start position:0% +it which +is terribly simple + + align:start position:0% +is terribly simple + + + align:start position:0% +is terribly simple +and + + align:start position:0% +and + + + align:start position:0% +and +uh it turns out + + align:start position:0% +uh it turns out + + + align:start position:0% +uh it turns out +that if you if you have an + + align:start position:0% +that if you if you have an + + + align:start position:0% +that if you if you have an +ocean and you make little + + align:start position:0% + + + + align:start position:0% + +bubbles + + align:start position:0% + + + + align:start position:0% + +by you have a little you have a tube + + align:start position:0% +by you have a little you have a tube + + + align:start position:0% +by you have a little you have a tube +running in back of a ship and it has + + align:start position:0% +running in back of a ship and it has + + + align:start position:0% +running in back of a ship and it has +little holes and if you make micronized + + align:start position:0% +little holes and if you make micronized + + + align:start position:0% +little holes and if you make micronized +bubbles then they turn the water white + + align:start position:0% +bubbles then they turn the water white + + + align:start position:0% +bubbles then they turn the water white +because uh the interface between water + + align:start position:0% +because uh the interface between water + + + align:start position:0% +because uh the interface between water +and air is a change of refractive index + + align:start position:0% +and air is a change of refractive index + + + align:start position:0% +and air is a change of refractive index +and that reflects a lot of light and uh + + align:start position:0% +and that reflects a lot of light and uh + + + align:start position:0% +and that reflects a lot of light and uh +it turns out that if you do that in + + align:start position:0% +it turns out that if you do that in + + + align:start position:0% +it turns out that if you do that in +distilled water the bubbles go away + + align:start position:0% +distilled water the bubbles go away + + + align:start position:0% +distilled water the bubbles go away +pretty quickly + + align:start position:0% +pretty quickly + + + align:start position:0% +pretty quickly +because the smaller a bubble is the + + align:start position:0% +because the smaller a bubble is the + + + align:start position:0% +because the smaller a bubble is the +higher the pressure inside everybody + + align:start position:0% +higher the pressure inside everybody + + + align:start position:0% +higher the pressure inside everybody +know + + align:start position:0% +know + + + align:start position:0% +know +why because surface tension is constant + + align:start position:0% +why because surface tension is constant + + + align:start position:0% +why because surface tension is constant +on the boundary + + align:start position:0% +on the boundary + + + align:start position:0% +on the boundary +so the pressure is proportional to the + + align:start position:0% +so the pressure is proportional to the + + + align:start position:0% +so the pressure is proportional to the +curvature + + align:start position:0% +curvature + + + align:start position:0% +curvature +because the smaller the bubble is the + + align:start position:0% +because the smaller the bubble is the + + + align:start position:0% +because the smaller the bubble is the +greater the force per square inch of + + align:start position:0% +greater the force per square inch of + + + align:start position:0% +greater the force per square inch of +surface of pull it + + align:start position:0% +surface of pull it + + + align:start position:0% +surface of pull it +in but in seawater there's enough oils + + align:start position:0% +in but in seawater there's enough oils + + + align:start position:0% +in but in seawater there's enough oils +and other things in any any uh cubic + + align:start position:0% +and other things in any any uh cubic + + + align:start position:0% +and other things in any any uh cubic +centimeter seawater to coat a micron + + align:start position:0% +centimeter seawater to coat a micron + + + align:start position:0% +centimeter seawater to coat a micron +siiz bubble with with a sort of in oily + + align:start position:0% +siiz bubble with with a sort of in oily + + + align:start position:0% +siiz bubble with with a sort of in oily +film or one that doesn't let the air out + + align:start position:0% +film or one that doesn't let the air out + + + align:start position:0% +film or one that doesn't let the air out +of the bubble so the bubble is good for + + align:start position:0% +of the bubble so the bubble is good for + + + align:start position:0% +of the bubble so the bubble is good for +several hours and the bubble tends to uh + + align:start position:0% +several hours and the bubble tends to uh + + + align:start position:0% +several hours and the bubble tends to uh +float up to the top stay in the top few + + align:start position:0% +float up to the top stay in the top few + + + align:start position:0% +float up to the top stay in the top few +inches of water and if there's a wave uh + + align:start position:0% +inches of water and if there's a wave uh + + + align:start position:0% +inches of water and if there's a wave uh +it goes down but it comes up again so + + align:start position:0% +it goes down but it comes up again so + + + align:start position:0% +it goes down but it comes up again so +his calculations show that if you have a + + align:start position:0% +his calculations show that if you have a + + + align:start position:0% +his calculations show that if you have a +few thousand ships which uh at any time + + align:start position:0% +few thousand ships which uh at any time + + + align:start position:0% +few thousand ships which uh at any time +in the crossing the Atlantic for example + + align:start position:0% +in the crossing the Atlantic for example + + + align:start position:0% +in the crossing the Atlantic for example +there are few thousand ships and each of + + align:start position:0% +there are few thousand ships and each of + + + align:start position:0% +there are few thousand ships and each of +them is producing a half mile wide + + align:start position:0% +them is producing a half mile wide + + + align:start position:0% +them is producing a half mile wide +streak of whiteness that + + align:start position:0% +streak of whiteness that + + + align:start position:0% +streak of whiteness that +lasts a few + + align:start position:0% +lasts a few + + + align:start position:0% +lasts a few +hours then you can change the + + align:start position:0% +hours then you can change the + + + align:start position:0% +hours then you can change the +reflectivity of of that part of the + + align:start position:0% +reflectivity of of that part of the + + + align:start position:0% +reflectivity of of that part of the +Earth by 2 or + + align:start position:0% +Earth by 2 or + + + align:start position:0% +Earth by 2 or +3% at very low energy + + align:start position:0% +3% at very low energy + + + align:start position:0% +3% at very low energy +cost and the nice thing is if it doesn't + + align:start position:0% +cost and the nice thing is if it doesn't + + + align:start position:0% +cost and the nice thing is if it doesn't +work you turn it off uh some of the + + align:start position:0% +work you turn it off uh some of the + + + align:start position:0% +work you turn it off uh some of the +plans are to put sulfur dioxide into the + + align:start position:0% +plans are to put sulfur dioxide into the + + + align:start position:0% +plans are to put sulfur dioxide into the +upper + + align:start position:0% +upper + + + align:start position:0% +upper +atmosphere and if it uh + + align:start position:0% +atmosphere and if it uh + + + align:start position:0% +atmosphere and if it uh +doesn't work you can't do anything for a + + align:start position:0% +doesn't work you can't do anything for a + + + align:start position:0% +doesn't work you can't do anything for a +few + + align:start position:0% +few + + + align:start position:0% +few +years so there's an ex there's a fairly + + align:start position:0% +years so there's an ex there's a fairly + + + align:start position:0% +years so there's an ex there's a fairly +expensive but not seriously expensive + + align:start position:0% +expensive but not seriously expensive + + + align:start position:0% +expensive but not seriously expensive +possible solution and + + align:start position:0% +possible solution and + + + align:start position:0% +possible solution and +uh it took him three or four years to + + align:start position:0% +uh it took him three or four years to + + + align:start position:0% +uh it took him three or four years to +convince anybody of it and now the idea + + align:start position:0% +convince anybody of it and now the idea + + + align:start position:0% +convince anybody of it and now the idea +might be catching on but every now and + + align:start position:0% +might be catching on but every now and + + + align:start position:0% +might be catching on but every now and +somebody invents something that actually + + align:start position:0% +somebody invents something that actually + + + align:start position:0% +somebody invents something that actually +works + + align:start position:0% +works + + + align:start position:0% +works +and that's a possibility + + align:start position:0% +and that's a possibility + + + align:start position:0% +and that's a possibility +uh maybe you can invent + + align:start position:0% + + + + align:start position:0% + +something painting roofs + + align:start position:0% +something painting roofs + + + align:start position:0% +something painting roofs +white also works but there aren't enough + + align:start position:0% +white also works but there aren't enough + + + align:start position:0% +white also works but there aren't enough +of + + align:start position:0% +of + + + align:start position:0% +of +them and you might have to clean them + + align:start position:0% +them and you might have to clean them + + + align:start position:0% +them and you might have to clean them +every now and + + align:start position:0% + + + + align:start position:0% + +then maybe it's time to reconsider laser + + align:start position:0% +then maybe it's time to reconsider laser + + + align:start position:0% +then maybe it's time to reconsider laser +powered volcano + + align:start position:0% +powered volcano + + + align:start position:0% +powered volcano +lensing amid huge amounts of particulate + + align:start position:0% +lensing amid huge amounts of particulate + + + align:start position:0% +lensing amid huge amounts of particulate +matter into the atmosphere by controlled + + align:start position:0% +matter into the atmosphere by controlled + + + align:start position:0% +matter into the atmosphere by controlled +a volcanic emission yes what was the was + + align:start position:0% +a volcanic emission yes what was the was + + + align:start position:0% +a volcanic emission yes what was the was +it + + align:start position:0% + + + + align:start position:0% + +1883 P or CA + + align:start position:0% +1883 P or CA + + + align:start position:0% +1883 P or CA +katoa the there was the year without a + + align:start position:0% +katoa the there was the year without a + + + align:start position:0% +katoa the there was the year without a +summer all over the world from one + + align:start position:0% +summer all over the world from one + + + align:start position:0% +summer all over the world from one +gigantic + + align:start position:0% +gigantic + + + align:start position:0% +gigantic +explosion so happen again this year + + align:start position:0% +explosion so happen again this year + + + align:start position:0% +explosion so happen again this year +thanks to + + align:start position:0% +thanks to + + + align:start position:0% +thanks to +Greenland what's that they're about to + + align:start position:0% +Greenland what's that they're about to + + + align:start position:0% +Greenland what's that they're about to +have a major eruption in greenand oh do + + align:start position:0% +have a major eruption in greenand oh do + + + align:start position:0% +have a major eruption in greenand oh do +you think it'll help or is it just going + + align:start position:0% +you think it'll help or is it just going + + + align:start position:0% +you think it'll help or is it just going +warm the water up a + + align:start position:0% +warm the water up a + + + align:start position:0% +warm the water up a +little I no they estimate this one may + + align:start position:0% +little I no they estimate this one may + + + align:start position:0% +little I no they estimate this one may +shut down air traffic over Europe for 2 + + align:start position:0% +shut down air traffic over Europe for 2 + + + align:start position:0% +shut down air traffic over Europe for 2 +years well people shouldn't travel + + align:start position:0% +years well people shouldn't travel + + + align:start position:0% +years well people shouldn't travel +anyway why don't they just use the + + align:start position:0% +anyway why don't they just use the + + + align:start position:0% +anyway why don't they just use the +internet and and uh + + align:start position:0% +internet and and uh + + + align:start position:0% +internet and and uh +Twitter well if they J every where the + + align:start position:0% +Twitter well if they J every where the + + + align:start position:0% +Twitter well if they J every where the +jet contrails are not too much different + + align:start position:0% +jet contrails are not too much different + + + align:start position:0% +jet contrails are not too much different +from the boat bubbles if we take a lot + + align:start position:0% +from the boat bubbles if we take a lot + + + align:start position:0% +from the boat bubbles if we take a lot +of airplanes but + + align:start position:0% + + + + align:start position:0% + +yes uh nobody knows if these bubbles + + align:start position:0% +yes uh nobody knows if these bubbles + + + align:start position:0% +yes uh nobody knows if these bubbles +would have a bad effect but it's hard + + align:start position:0% + + + + align:start position:0% + +but the nice thing is you could turn + + align:start position:0% +but the nice thing is you could turn + + + align:start position:0% +but the nice thing is you could turn +them off in a few + + align:start position:0% + + + + align:start position:0% + +hours he's gotten some attention from + + align:start position:0% +hours he's gotten some attention from + + + align:start position:0% +hours he's gotten some attention from +people who want to conserve water in the + + align:start position:0% +people who want to conserve water in the + + + align:start position:0% +people who want to conserve water in the +Colorado Basin and + + align:start position:0% +Colorado Basin and + + + align:start position:0% +Colorado Basin and +places for better for worse there's + + align:start position:0% +places for better for worse there's + + + align:start position:0% +places for better for worse there's +nobody in charge of the Earth so uh + + align:start position:0% +nobody in charge of the Earth so uh + + + align:start position:0% +nobody in charge of the Earth so uh +nobody wants to spend any money on that + + align:start position:0% +nobody wants to spend any money on that + + + align:start position:0% +nobody wants to spend any money on that +unless they can get their money + + align:start position:0% + + + + align:start position:0% + +back I have lots of + + align:start position:0% + + + + align:start position:0% + +disasters but I want a new one so do you + + align:start position:0% +disasters but I want a new one so do you + + + align:start position:0% +disasters but I want a new one so do you +believe in global + + align:start position:0% +believe in global + + + align:start position:0% +believe in global +warming oh well that is happening now + + align:start position:0% +warming oh well that is happening now + + + align:start position:0% +warming oh well that is happening now +the Chinese say it's global cooling + + align:start position:0% +the Chinese say it's global cooling + + + align:start position:0% +the Chinese say it's global cooling +until 2068 + + align:start position:0% +until 2068 + + + align:start position:0% +until 2068 +well somebody might be right but + + align:start position:0% +well somebody might be right but + + + align:start position:0% +well somebody might be right but +uh as far as I know all the big + + align:start position:0% +uh as far as I know all the big + + + align:start position:0% +uh as far as I know all the big +simulations uh claim to get a few + + align:start position:0% +simulations uh claim to get a few + + + align:start position:0% +simulations uh claim to get a few +degrees per a degree per decade or + + align:start position:0% +degrees per a degree per decade or + + + align:start position:0% +degrees per a degree per decade or +something don't + + align:start position:0% +something don't + + + align:start position:0% +something don't +they + + align:start position:0% +they + + + align:start position:0% +they +um the Western models tend to + + align:start position:0% +um the Western models tend to + + + align:start position:0% +um the Western models tend to +underestimate the the role of the Sun in + + align:start position:0% +underestimate the the role of the Sun in + + + align:start position:0% +underestimate the the role of the Sun in +it so things like the M minimum if it's + + align:start position:0% +it so things like the M minimum if it's + + + align:start position:0% +it so things like the M minimum if it's +in fact coming that was 300 years or + + align:start position:0% +in fact coming that was 300 years or + + + align:start position:0% +in fact coming that was 300 years or +something + + align:start position:0% +something + + + align:start position:0% +something +yes well if you knew how to turn that on + + align:start position:0% +yes well if you knew how to turn that on + + + align:start position:0% +yes well if you knew how to turn that on +that would + + align:start position:0% + + + + align:start position:0% + +help well we seem to be going into a Sol + + align:start position:0% +help well we seem to be going into a Sol + + + align:start position:0% +help well we seem to be going into a Sol +minimum now where there is low flux and + + align:start position:0% +minimum now where there is low flux and + + + align:start position:0% +minimum now where there is low flux and +sun spots but no there no sun spots this + + align:start position:0% +sun spots but no there no sun spots this + + + align:start position:0% +sun spots but no there no sun spots this +year nobody knows why + + align:start position:0% +year nobody knows why + + + align:start position:0% +year nobody knows why +or well a few people know why but nobody + + align:start position:0% +or well a few people know why but nobody + + + align:start position:0% +or well a few people know why but nobody +knows which ones they are + + align:start position:0% +knows which ones they are + + + align:start position:0% +knows which ones they are +well it's the end of the mayor calendar + + align:start position:0% +well it's the end of the mayor calendar + + + align:start position:0% +well it's the end of the mayor calendar +so of which the mayor calendar calendar + + align:start position:0% +so of which the mayor calendar calendar + + + align:start position:0% +so of which the mayor calendar calendar +they they didn't have next year 20122 + + align:start position:0% +they they didn't have next year 20122 + + + align:start position:0% +they they didn't have next year 20122 +it's like December oh next year so uh is + + align:start position:0% +it's like December oh next year so uh is + + + align:start position:0% +it's like December oh next year so uh is +there just one + + align:start position:0% +there just one + + + align:start position:0% +there just one +copy I think I've seen it somewhere it's + + align:start position:0% +copy I think I've seen it somewhere it's + + + align:start position:0% +copy I think I've seen it somewhere it's +in + + align:start position:0% + + + + align:start position:0% + +Yucatan when I was a + + align:start position:0% + + + + align:start position:0% + +kid and they explained that the oh never + + align:start position:0% +kid and they explained that the oh never + + + align:start position:0% +kid and they explained that the oh never +mind Human Sacrifice + + align:start position:0% +mind Human Sacrifice + + + align:start position:0% +mind Human Sacrifice +place but it worked everybody makes fun + + align:start position:0% +place but it worked everybody makes fun + + + align:start position:0% +place but it worked everybody makes fun +of human sacrifice + + align:start position:0% +of human sacrifice + + + align:start position:0% +of human sacrifice +but here we are and then + + align:start position:0% + + + + align:start position:0% + +is it going up it's on stra yeah doesn't + + align:start position:0% +is it going up it's on stra yeah doesn't + + + align:start position:0% +is it going up it's on stra yeah doesn't +matter I'm just looking at my + + align:start position:0% + + + + align:start position:0% + +notes so is there anything when your + + align:start position:0% +notes so is there anything when your + + + align:start position:0% +notes so is there anything when your +release that will be cured by smarter + + align:start position:0% + + + + align:start position:0% + +people what if they didn't + + align:start position:0% + + + + align:start position:0% + +agree if people were really smart then + + align:start position:0% +agree if people were really smart then + + + align:start position:0% +agree if people were really smart then +they would agree is that + + align:start position:0% +they would agree is that + + + align:start position:0% +they would agree is that +possible I don't know I don't know what + + align:start position:0% +possible I don't know I don't know what + + + align:start position:0% +possible I don't know I don't know what +it means I didn't either + + align:start position:0% + + + + align:start position:0% + +well that's a serious question I + + align:start position:0% +well that's a serious question I + + + align:start position:0% +well that's a serious question I +mean what do you think people should + + align:start position:0% +mean what do you think people should + + + align:start position:0% +mean what do you think people should +work on if you were going to do a PhD + + align:start position:0% +work on if you were going to do a PhD + + + align:start position:0% +work on if you were going to do a PhD +thesis on + + align:start position:0% +thesis on + + + align:start position:0% +thesis on +AI what would + + align:start position:0% +AI what would + + + align:start position:0% +AI what would +you what would you aim + + align:start position:0% +you what would you aim + + + align:start position:0% +you what would you aim +toward and + + align:start position:0% + + + + align:start position:0% + +uh recently we had a student + + align:start position:0% +uh recently we had a student + + + align:start position:0% +uh recently we had a student +who had just decided for some reason to + + align:start position:0% +who had just decided for some reason to + + + align:start position:0% +who had just decided for some reason to +to + + align:start position:0% + + + + align:start position:0% + +uh imagine a common sensical kitchen + + align:start position:0% + + + + align:start position:0% + +project so the point was the idea was + + align:start position:0% + + + + align:start position:0% + +that uh as as you know various projects + + align:start position:0% +that uh as as you know various projects + + + align:start position:0% +that uh as as you know various projects +including at MIT are collecting Common + + align:start position:0% +including at MIT are collecting Common + + + align:start position:0% +including at MIT are collecting Common +Sense knowledge about the world and + + align:start position:0% +Sense knowledge about the world and + + + align:start position:0% +Sense knowledge about the world and +trying to make programs and do do + + align:start position:0% +trying to make programs and do do + + + align:start position:0% +trying to make programs and do do +reasoning about it + + align:start position:0% +reasoning about it + + + align:start position:0% +reasoning about it +uh Henry lieberman's project here is + + align:start position:0% +uh Henry lieberman's project here is + + + align:start position:0% +uh Henry lieberman's project here is +uh the most famous one is the psych + + align:start position:0% +uh the most famous one is the psych + + + align:start position:0% +uh the most famous one is the psych +project that I mentioned before it's the + + align:start position:0% +project that I mentioned before it's the + + + align:start position:0% +project that I mentioned before it's the +same Len at fellow after he uh wrote + + align:start position:0% +same Len at fellow after he uh wrote + + + align:start position:0% +same Len at fellow after he uh wrote +These early uh AI programs that solved + + align:start position:0% +These early uh AI programs that solved + + + align:start position:0% +These early uh AI programs that solved +mathematical problems and simulated + + align:start position:0% +mathematical problems and simulated + + + align:start position:0% +mathematical problems and simulated +Evolution and little things like + + align:start position:0% +Evolution and little things like + + + align:start position:0% +Evolution and little things like +that then he decided + + align:start position:0% +that then he decided + + + align:start position:0% +that then he decided +that you couldn't really have a smart + + align:start position:0% +that you couldn't really have a smart + + + align:start position:0% +that you couldn't really have a smart +machine unless it knew a lot because it + + align:start position:0% +machine unless it knew a lot because it + + + align:start position:0% +machine unless it knew a lot because it +might take a thousand years to + + align:start position:0% +might take a thousand years to + + + align:start position:0% +might take a thousand years to +accumulate knowledge just by uh doing + + align:start position:0% +accumulate knowledge just by uh doing + + + align:start position:0% +accumulate knowledge just by uh doing +experiments so U I think lennet was the + + align:start position:0% +experiments so U I think lennet was the + + + align:start position:0% +experiments so U I think lennet was the +first one to start accumulating a large + + align:start position:0% +first one to start accumulating a large + + + align:start position:0% +first one to start accumulating a large +Common Sense knowledge base and + + align:start position:0% +Common Sense knowledge base and + + + align:start position:0% +Common Sense knowledge base and +I imagine + + align:start position:0% +I imagine + + + align:start position:0% +I imagine +that that current project may still be + + align:start position:0% +that that current project may still be + + + align:start position:0% +that that current project may still be +the largest one I don't + + align:start position:0% + + + + align:start position:0% + +know psych is short for encyclopedia or + + align:start position:0% +know psych is short for encyclopedia or + + + align:start position:0% +know psych is short for encyclopedia or +something and + + align:start position:0% + + + + align:start position:0% + +U so we did have a student who said well + + align:start position:0% +U so we did have a student who said well + + + align:start position:0% +U so we did have a student who said well +here's a nice quiet world the kitchen + + align:start position:0% +here's a nice quiet world the kitchen + + + align:start position:0% +here's a nice quiet world the kitchen +world and you want to make something + + align:start position:0% +world and you want to make something + + + align:start position:0% +world and you want to make something +that has certain properties so you have + + align:start position:0% +that has certain properties so you have + + + align:start position:0% +that has certain properties so you have +to figure out what ingredients and how + + align:start position:0% +to figure out what ingredients and how + + + align:start position:0% +to figure out what ingredients and how +long to cook them or you have a + + align:start position:0% +long to cook them or you have a + + + align:start position:0% +long to cook them or you have a +knowledge base with recipes and then if + + align:start position:0% +knowledge base with recipes and then if + + + align:start position:0% +knowledge base with recipes and then if +somebody wants something new + + align:start position:0% +somebody wants something new + + + align:start position:0% +somebody wants something new +you so that's a typical project and uh + + align:start position:0% +you so that's a typical project and uh + + + align:start position:0% +you so that's a typical project and uh +several of us talked to that student out + + align:start position:0% +several of us talked to that student out + + + align:start position:0% +several of us talked to that student out +of it or managed to and um + + align:start position:0% + + + + align:start position:0% + +because we didn't see any + + align:start position:0% +because we didn't see any + + + align:start position:0% +because we didn't see any +uh we didn't see any chance of the + + align:start position:0% +uh we didn't see any chance of the + + + align:start position:0% +uh we didn't see any chance of the +Colossus + + align:start position:0% +Colossus + + + align:start position:0% +Colossus +disaster uh + + align:start position:0% +disaster uh + + + align:start position:0% +disaster uh +coming it's almost the opposite I keep + + align:start position:0% +coming it's almost the opposite I keep + + + align:start position:0% +coming it's almost the opposite I keep +getting messages from the friendly AI + + align:start position:0% +getting messages from the friendly AI + + + align:start position:0% +getting messages from the friendly AI +society and that this ex there exists a + + align:start position:0% +society and that this ex there exists a + + + align:start position:0% +society and that this ex there exists a +bunch of apparently smart people who are + + align:start position:0% +bunch of apparently smart people who are + + + align:start position:0% +bunch of apparently smart people who are +saying how can we do AI research without + + align:start position:0% +saying how can we do AI research without + + + align:start position:0% +saying how can we do AI research without +the risk of making a machine that's + + align:start position:0% +the risk of making a machine that's + + + align:start position:0% +the risk of making a machine that's +suddenly becomes very smart and takes + + align:start position:0% +suddenly becomes very smart and takes + + + align:start position:0% +suddenly becomes very smart and takes +over the world and kills everybody and + + align:start position:0% +over the world and kills everybody and + + + align:start position:0% +over the world and kills everybody and +U they write all these papers about ways + + align:start position:0% +U they write all these papers about ways + + + align:start position:0% +U they write all these papers about ways +to make friendly Ai and they + + align:start position:0% +to make friendly Ai and they + + + align:start position:0% +to make friendly Ai and they +have discussion groups where somebody + + align:start position:0% +have discussion groups where somebody + + + align:start position:0% +have discussion groups where somebody +proposes such a thing and somebody else + + align:start position:0% +proposes such a thing and somebody else + + + align:start position:0% +proposes such a thing and somebody else +points out five obviously obvious bugs + + align:start position:0% +points out five obviously obvious bugs + + + align:start position:0% +points out five obviously obvious bugs +in that and these people are uh pretty + + align:start position:0% +in that and these people are uh pretty + + + align:start position:0% +in that and these people are uh pretty +serious just look up friendly a I on + + align:start position:0% +serious just look up friendly a I on + + + align:start position:0% +serious just look up friendly a I on +your browser yes Professor do you think + + align:start position:0% +your browser yes Professor do you think + + + align:start position:0% +your browser yes Professor do you think +that sort of Terminator you know + + align:start position:0% +that sort of Terminator you know + + + align:start position:0% +that sort of Terminator you know +Hollywood movie scas of scenario is a + + align:start position:0% +Hollywood movie scas of scenario is a + + + align:start position:0% +Hollywood movie scas of scenario is a +legitimate concern yes uh I think there + + align:start position:0% +legitimate concern yes uh I think there + + + align:start position:0% +legitimate concern yes uh I think there +are a lot + + align:start position:0% +are a lot + + + align:start position:0% +are a lot +of I think the + + align:start position:0% +of I think the + + + align:start position:0% +of I think the +smallpox uh the 100% lethal smallpox is + + align:start position:0% +smallpox uh the 100% lethal smallpox is + + + align:start position:0% +smallpox uh the 100% lethal smallpox is +what this one was advertised as how many + + align:start position:0% +what this one was advertised as how many + + + align:start position:0% +what this one was advertised as how many +of you saw the press release on that + + align:start position:0% +of you saw the press release on that + + + align:start position:0% +of you saw the press release on that +three or four + + align:start position:0% +three or four + + + align:start position:0% +three or four +it killed all the + + align:start position:0% + + + + align:start position:0% + +mice I think it was 12 mice + + align:start position:0% +mice I think it was 12 mice + + + align:start position:0% +mice I think it was 12 mice +but there might have been something else + + align:start position:0% +but there might have been something else + + + align:start position:0% +but there might have been something else +in their food who + + align:start position:0% +in their food who + + + align:start position:0% +in their food who +knows yes I think it's a serious problem + + align:start position:0% +knows yes I think it's a serious problem + + + align:start position:0% +knows yes I think it's a serious problem +and + + align:start position:0% +and + + + align:start position:0% +and +it's + + align:start position:0% +it's + + + align:start position:0% +it's +uh it would be great if somebody in that + + align:start position:0% +uh it would be great if somebody in that + + + align:start position:0% +uh it would be great if somebody in that +group actually got a good idea about how + + align:start position:0% +group actually got a good idea about how + + + align:start position:0% +group actually got a good idea about how +to look how to detect these trouble + + align:start position:0% +to look how to detect these trouble + + + align:start position:0% +to look how to detect these trouble +before they + + align:start position:0% +before they + + + align:start position:0% +before they +spread I just don't recommend any of you + + align:start position:0% +spread I just don't recommend any of you + + + align:start position:0% +spread I just don't recommend any of you +work on it uh for your thesis or + + align:start position:0% +work on it uh for your thesis or + + + align:start position:0% +work on it uh for your thesis or +something because I don't think there's + + align:start position:0% +something because I don't think there's + + + align:start position:0% +something because I don't think there's +a good + + align:start position:0% + + + + align:start position:0% + +answer see if it gets smarter than all + + align:start position:0% +answer see if it gets smarter than all + + + align:start position:0% +answer see if it gets smarter than all +the people put together in five minutes + + align:start position:0% +the people put together in five minutes + + + align:start position:0% +the people put together in five minutes +then nothing we've thought + + align:start position:0% +then nothing we've thought + + + align:start position:0% +then nothing we've thought +of could stop it but I mean something + + align:start position:0% +of could stop it but I mean something + + + align:start position:0% +of could stop it but I mean something +different from small + + align:start position:0% +different from small + + + align:start position:0% +different from small +self-governing sort of + + align:start position:0% + + + + align:start position:0% + +entity it's very hard + + align:start position:0% + + + + align:start position:0% + +to well in the Colossus novel which is + + align:start position:0% +to well in the Colossus novel which is + + + align:start position:0% +to well in the Colossus novel which is +quite well worked out uh the machine + + align:start position:0% +quite well worked out uh the machine + + + align:start position:0% +quite well worked out uh the machine +says this creature from outer space is + + align:start position:0% +says this creature from outer space is + + + align:start position:0% +says this creature from outer space is +coming and from Its Behavior you can see + + align:start position:0% +coming and from Its Behavior you can see + + + align:start position:0% +coming and from Its Behavior you can see +that it's a really super intelligent + + align:start position:0% +that it's a really super intelligent + + + align:start position:0% +that it's a really super intelligent +thing it's + + align:start position:0% +thing it's + + + align:start position:0% +thing it's +uh it's really dangerous and so I have + + align:start position:0% +uh it's really dangerous and so I have + + + align:start position:0% +uh it's really dangerous and so I have +to get the people to support me to + + align:start position:0% +to get the people to support me to + + + align:start position:0% +to get the people to support me to +uh to figure out some way I mean how do + + align:start position:0% +uh to figure out some way I mean how do + + + align:start position:0% +uh to figure out some way I mean how do +you stop a thing that's coming at almost + + align:start position:0% +you stop a thing that's coming at almost + + + align:start position:0% +you stop a thing that's coming at almost +the speed of light and blah blah blah uh + + align:start position:0% +the speed of light and blah blah blah uh + + + align:start position:0% +the speed of light and blah blah blah uh +maybe the only solution is to change + + align:start position:0% +maybe the only solution is to change + + + align:start position:0% +maybe the only solution is to change +physics so you have to think of some + + align:start position:0% +physics so you have to think of some + + + align:start position:0% +physics so you have to think of some +very once you understand physics very + + align:start position:0% +very once you understand physics very + + + align:start position:0% +very once you understand physics very +well maybe you can turn a switch and + + align:start position:0% +well maybe you can turn a switch and + + + align:start position:0% +well maybe you can turn a switch and +change the gravitational concept and so + + align:start position:0% +change the gravitational concept and so + + + align:start position:0% +change the gravitational concept and so +forth and if you start fooling around + + align:start position:0% +forth and if you start fooling around + + + align:start position:0% +forth and if you start fooling around +with that then there's probably only one + + align:start position:0% +with that then there's probably only one + + + align:start position:0% +with that then there's probably only one +chance in 10 to the 10th you can do that + + align:start position:0% +chance in 10 to the 10th you can do that + + + align:start position:0% +chance in 10 to the 10th you can do that +without uh turning the universe into a + + align:start position:0% +without uh turning the universe into a + + + align:start position:0% +without uh turning the universe into a +black hole so all of these large scale + + align:start position:0% +black hole so all of these large scale + + + align:start position:0% +black hole so all of these large scale +Adventures are very risky + + align:start position:0% + + + + align:start position:0% + +so were you afraid to make an AI if you + + align:start position:0% + + + + align:start position:0% + +could it seems like a self-replicating + + align:start position:0% +could it seems like a self-replicating + + + align:start position:0% +could it seems like a self-replicating +thing may be just as dangerous as the + + align:start position:0% +thing may be just as dangerous as the + + + align:start position:0% +thing may be just as dangerous as the +meanest of + + align:start position:0% +meanest of + + + align:start position:0% +meanest of +AI + + align:start position:0% +AI + + + align:start position:0% +AI +mhm yeah itself massively Michael kryon + + align:start position:0% +mhm yeah itself massively Michael kryon + + + align:start position:0% +mhm yeah itself massively Michael kryon +had a nice novel I forget how + + align:start position:0% +had a nice novel I forget how + + + align:start position:0% +had a nice novel I forget how +he what happened to did anybody read the + + align:start position:0% +he what happened to did anybody read the + + + align:start position:0% +he what happened to did anybody read the +his nanotech novel prey gray what was it + + align:start position:0% +his nanotech novel prey gray what was it + + + align:start position:0% +his nanotech novel prey gray what was it +called + + align:start position:0% +called + + + align:start position:0% +called +prey P yes right what was the solution + + align:start position:0% +prey P yes right what was the solution + + + align:start position:0% +prey P yes right what was the solution +or was there one I don't remember it's + + align:start position:0% +or was there one I don't remember it's + + + align:start position:0% +or was there one I don't remember it's +been a while since I've read it I don't + + align:start position:0% +been a while since I've read it I don't + + + align:start position:0% +been a while since I've read it I don't +remember not sure I got to the + + align:start position:0% + + + + align:start position:0% + +end yes I suspect that AI if it's able + + align:start position:0% +end yes I suspect that AI if it's able + + + align:start position:0% +end yes I suspect that AI if it's able +within 5 minutes to make itself that + + align:start position:0% +within 5 minutes to make itself that + + + align:start position:0% +within 5 minutes to make itself that +much smarter is going to strip + + align:start position:0% +much smarter is going to strip + + + align:start position:0% +much smarter is going to strip +self-replicating machines because + + align:start position:0% +self-replicating machines because + + + align:start position:0% +self-replicating machines because +self-replicating machines have to + + align:start position:0% +self-replicating machines have to + + + align:start position:0% +self-replicating machines have to +constantly requisition resources for + + align:start position:0% +constantly requisition resources for + + + align:start position:0% +constantly requisition resources for +themselves and each of them are only as + + align:start position:0% +themselves and each of them are only as + + + align:start position:0% +themselves and each of them are only as +intelligent basically as the cells on + + align:start position:0% +intelligent basically as the cells on + + + align:start position:0% +intelligent basically as the cells on +the edges whereas the centralized AI get + + align:start position:0% +the edges whereas the centralized AI get + + + align:start position:0% +the edges whereas the centralized AI get +a lot of uh computing power yeah + + align:start position:0% +a lot of uh computing power yeah + + + align:start position:0% +a lot of uh computing power yeah +well if it wants 10 to the + + align:start position:0% +well if it wants 10 to the + + + align:start position:0% +well if it wants 10 to the +30th uh bits of + + align:start position:0% +30th uh bits of + + + align:start position:0% +30th uh bits of +memory uh it'll probably have to make a + + align:start position:0% +memory uh it'll probably have to make a + + + align:start position:0% +memory uh it'll probably have to make a +you'll have to make a self replic memory + + align:start position:0% +you'll have to make a self replic memory + + + align:start position:0% +you'll have to make a self replic memory +system but but + + align:start position:0% +system but but + + + align:start position:0% +system but but +uh it would surely be smart enough not + + align:start position:0% +uh it would surely be smart enough not + + + align:start position:0% +uh it would surely be smart enough not +to make one that will wipe itself + + align:start position:0% +to make one that will wipe itself + + + align:start position:0% +to make one that will wipe itself +out + + align:start position:0% + + + + align:start position:0% + +because the solution in prey was very + + align:start position:0% +because the solution in prey was very + + + align:start position:0% +because the solution in prey was very +similar to War of the Worlds they + + align:start position:0% +similar to War of the Worlds they + + + align:start position:0% +similar to War of the Worlds they +defeated it with the virus oh + + align:start position:0% +defeated it with the virus oh + + + align:start position:0% +defeated it with the virus oh +what yes a Fage did they make their own + + align:start position:0% +what yes a Fage did they make their own + + + align:start position:0% +what yes a Fage did they make their own +or did it just evolve they made their + + align:start position:0% +or did it just evolve they made their + + + align:start position:0% +or did it just evolve they made their +own high school students course in the + + align:start position:0% +own high school students course in the + + + align:start position:0% +own high school students course in the +HG in the HG Wells one the virus just + + align:start position:0% +HG in the HG Wells one the virus just + + + align:start position:0% +HG in the HG Wells one the virus just +happened to be there and the people + + align:start position:0% +happened to be there and the people + + + align:start position:0% +happened to be there and the people +didn't make it + + align:start position:0% +didn't make it + + + align:start position:0% +didn't make it +but but HG Wells must have written that + + align:start position:0% +but but HG Wells must have written that + + + align:start position:0% +but but HG Wells must have written that +around + + align:start position:0% +around + + + align:start position:0% +around +19 10 or something like + + align:start position:0% + + + + align:start position:0% + +that we like the idea that various end + + align:start position:0% +that we like the idea that various end + + + align:start position:0% +that we like the idea that various end +of world uh scenarios cancel each other + + align:start position:0% +of world uh scenarios cancel each other + + + align:start position:0% +of world uh scenarios cancel each other +out + + align:start position:0% + + + + align:start position:0% + +M well the news about that small pox + + align:start position:0% +M well the news about that small pox + + + align:start position:0% +M well the news about that small pox +virus was pretty + + align:start position:0% + + + + align:start position:0% + +scary I wonder if it's been + + align:start position:0% +scary I wonder if it's been + + + align:start position:0% +scary I wonder if it's been +published is the small pox virus + + align:start position:0% +published is the small pox virus + + + align:start position:0% +published is the small pox virus +sequence in public public property now + + align:start position:0% + + + + align:start position:0% + +because you could make one + + align:start position:0% +because you could make one + + + align:start position:0% +because you could make one +for in your backyard + + align:start position:0% + + + + align:start position:0% + +seller so you're saying that bad + + align:start position:0% +seller so you're saying that bad + + + align:start position:0% +seller so you're saying that bad +homework by high school students could + + align:start position:0% +homework by high school students could + + + align:start position:0% +homework by high school students could +be a + + align:start position:0% +be a + + + align:start position:0% +be a +catastrophe wait a minute I think it was + + align:start position:0% +catastrophe wait a minute I think it was + + + align:start position:0% +catastrophe wait a minute I think it was +a flu virus wasn't it yeah oh yeah + + align:start position:0% +a flu virus wasn't it yeah oh yeah + + + align:start position:0% +a flu virus wasn't it yeah oh yeah +that's what I heard sorry that's small + + align:start position:0% +that's what I heard sorry that's small + + + align:start position:0% +that's what I heard sorry that's small +box small box was pretty + + align:start position:0% +box small box was pretty + + + align:start position:0% +box small box was pretty +bad and we're still getting vaccinated + + align:start position:0% +bad and we're still getting vaccinated + + + align:start position:0% +bad and we're still getting vaccinated +for it aren't + + align:start position:0% +for it aren't + + + align:start position:0% +for it aren't +we what + + align:start position:0% +we what + + + align:start position:0% +we what +was I forgot the + + align:start position:0% + + + + align:start position:0% + +question never get an idea while you're + + align:start position:0% +question never get an idea while you're + + + align:start position:0% +question never get an idea while you're +listening to someone else + + align:start position:0% + + + + align:start position:0% + +yes so one of the problems is aging and + + align:start position:0% +yes so one of the problems is aging and + + + align:start position:0% +yes so one of the problems is aging and +there are people working on that but I + + align:start position:0% +there are people working on that but I + + + align:start position:0% +there are people working on that but I +think in parall there are people + + align:start position:0% +think in parall there are people + + + align:start position:0% +think in parall there are people +struggling to like you said you went + + align:start position:0% +struggling to like you said you went + + + align:start position:0% +struggling to like you said you went +into a room and asked people how how + + align:start position:0% +into a room and asked people how how + + + align:start position:0% +into a room and asked people how how +many of them wanted to live forever and + + align:start position:0% +many of them wanted to live forever and + + + align:start position:0% +many of them wanted to live forever and +just a handful then you went into a room + + align:start position:0% +just a handful then you went into a room + + + align:start position:0% +just a handful then you went into a room +of scientists and a lot more so that + + align:start position:0% +of scientists and a lot more so that + + + align:start position:0% +of scientists and a lot more so that +speaks to people working on some + + align:start position:0% +speaks to people working on some + + + align:start position:0% +speaks to people working on some +problems or + + align:start position:0% +problems or + + + align:start position:0% +problems or +an interest or purpose of some sort now + + align:start position:0% +an interest or purpose of some sort now + + + align:start position:0% +an interest or purpose of some sort now +if anti-aging worked and now we have a + + align:start position:0% +if anti-aging worked and now we have a + + + align:start position:0% +if anti-aging worked and now we have a +lot more people living a lot longer with + + align:start position:0% +lot more people living a lot longer with + + + align:start position:0% +lot more people living a lot longer with +no + + align:start position:0% +no + + + align:start position:0% +no +control and no purpose or at least + + align:start position:0% +control and no purpose or at least + + + align:start position:0% +control and no purpose or at least +limited purpose and just a handful + + align:start position:0% +limited purpose and just a handful + + + align:start position:0% +limited purpose and just a handful +working on them question is how do you + + align:start position:0% +working on them question is how do you + + + align:start position:0% +working on them question is how do you +get more people interested without I + + align:start position:0% +get more people interested without I + + + align:start position:0% +get more people interested without I +mean to work on some problems and + + align:start position:0% +mean to work on some problems and + + + align:start position:0% +mean to work on some problems and +without indulging any philosophy of what + + align:start position:0% +without indulging any philosophy of what + + + align:start position:0% +without indulging any philosophy of what +purposes and is how do we get more + + align:start position:0% +purposes and is how do we get more + + + align:start position:0% +purposes and is how do we get more +people interesting + + align:start position:0% +people interesting + + + align:start position:0% +people interesting +I have a friend who's doing that uh + + align:start position:0% +I have a friend who's doing that uh + + + align:start position:0% +I have a friend who's doing that uh +Gregory Benford how many of + + align:start position:0% +Gregory Benford how many of + + + align:start position:0% +Gregory Benford how many of +you know that he's a First Rate science + + align:start position:0% +you know that he's a First Rate science + + + align:start position:0% +you know that he's a First Rate science +fiction + + align:start position:0% +fiction + + + align:start position:0% +fiction +writer and + + align:start position:0% + + + + align:start position:0% + +uh unlike most science fiction writers + + align:start position:0% +uh unlike most science fiction writers + + + align:start position:0% +uh unlike most science fiction writers +he's also a + + align:start position:0% +he's also a + + + align:start position:0% +he's also a +uh a very able + + align:start position:0% +uh a very able + + + align:start position:0% +uh a very able +physicist and has a had + + align:start position:0% +physicist and has a had + + + align:start position:0% +physicist and has a had +a substantial career + + align:start position:0% + + + + align:start position:0% + +in low energy + + align:start position:0% +in low energy + + + align:start position:0% +in low energy +physics + + align:start position:0% +physics + + + align:start position:0% +physics +namely um when he was a young physicist + + align:start position:0% +namely um when he was a young physicist + + + align:start position:0% +namely um when he was a young physicist +looking for what to + + align:start position:0% +looking for what to + + + align:start position:0% +looking for what to +do somebody uh said they were throwing + + align:start position:0% +do somebody uh said they were throwing + + + align:start position:0% +do somebody uh said they were throwing +out their + + align:start position:0% + + + + align:start position:0% + +cyclotron cyclotron + + align:start position:0% +cyclotron cyclotron + + + align:start position:0% +cyclotron cyclotron +is this cylindrical machine + + align:start position:0% +is this cylindrical machine + + + align:start position:0% +is this cylindrical machine +about his is about 12T in diameter and + + align:start position:0% +about his is about 12T in diameter and + + + align:start position:0% +about his is about 12T in diameter and +weighs quite a few + + align:start position:0% +weighs quite a few + + + align:start position:0% +weighs quite a few +tons and uh + + align:start position:0% +tons and uh + + + align:start position:0% +tons and uh +they said of course all the young + + align:start position:0% +they said of course all the young + + + align:start position:0% +they said of course all the young +physicists were to work on high energy + + align:start position:0% +physicists were to work on high energy + + + align:start position:0% +physicists were to work on high energy +things and this thing only makes a few + + align:start position:0% +things and this thing only makes a few + + + align:start position:0% +things and this thing only makes a few +million electron volts nobody's + + align:start position:0% +million electron volts nobody's + + + align:start position:0% +million electron volts nobody's +interested in such a small + + align:start position:0% +interested in such a small + + + align:start position:0% +interested in such a small +exponent so he got it and uh set up a + + align:start position:0% +exponent so he got it and uh set up a + + + align:start position:0% +exponent so he got it and uh set up a +laboratory in Irvine + + align:start position:0% + + + + align:start position:0% + +University but anyway uh in the last few + + align:start position:0% +University but anyway uh in the last few + + + align:start position:0% +University but anyway uh in the last few +years + + align:start position:0% +years + + + align:start position:0% +years +he started working on uh selecting + + align:start position:0% +he started working on uh selecting + + + align:start position:0% +he started working on uh selecting +dropa that live + + align:start position:0% +dropa that live + + + align:start position:0% +dropa that live +long and he has some that live about + + align:start position:0% +long and he has some that live about + + + align:start position:0% +long and he has some that live about +somewhere between two and three times as + + align:start position:0% +somewhere between two and three times as + + + align:start position:0% +somewhere between two and three times as +long as regular + + align:start position:0% +long as regular + + + align:start position:0% +long as regular +dropa and he's he knows a lot about what + + align:start position:0% +dropa and he's he knows a lot about what + + + align:start position:0% +dropa and he's he knows a lot about what +genes might are probably involved in + + align:start position:0% +genes might are probably involved in + + + align:start position:0% +genes might are probably involved in +that and uh has a + + align:start position:0% +that and uh has a + + + align:start position:0% +that and uh has a +company which uh + + align:start position:0% + + + + align:start position:0% + +I bet you could invest in if you + + align:start position:0% + + + + align:start position:0% + +want uh but that's the only one I know + + align:start position:0% + + + + align:start position:0% + +of so the next thing would be to go to + + align:start position:0% +of so the next thing would be to go to + + + align:start position:0% +of so the next thing would be to go to +mice and the great thing about I think + + align:start position:0% +mice and the great thing about I think + + + align:start position:0% +mice and the great thing about I think +the drop is five days or + + align:start position:0% +the drop is five days or + + + align:start position:0% +the drop is five days or +something to reproduce which + + align:start position:0% +something to reproduce which + + + align:start position:0% +something to reproduce which +is some very short time + + align:start position:0% +is some very short time + + + align:start position:0% +is some very short time +so that way you can do hundreds of years + + align:start position:0% +so that way you can do hundreds of years + + + align:start position:0% +so that way you can do hundreds of years +of experiments every + + align:start position:0% + + + + align:start position:0% + +term was + + align:start position:0% +term was + + + align:start position:0% +term was +there so I wonder how many other people + + align:start position:0% +there so I wonder how many other people + + + align:start position:0% +there so I wonder how many other people +are trying to make longer lived fleas + + align:start position:0% +are trying to make longer lived fleas + + + align:start position:0% +are trying to make longer lived fleas +and then work their way up the + + align:start position:0% + + + + align:start position:0% + +evolutionary because nobody knows much + + align:start position:0% +evolutionary because nobody knows much + + + align:start position:0% +evolutionary because nobody knows much +about aging the the + + align:start position:0% +about aging the the + + + align:start position:0% +about aging the the +most well established thing is + + align:start position:0% +most well established thing is + + + align:start position:0% +most well established thing is +the what do you call the stuff at the + + align:start position:0% +the what do you call the stuff at the + + + align:start position:0% +the what do you call the stuff at the +end of + + align:start position:0% +end of + + + align:start position:0% +end of +chromosomes + + align:start position:0% +chromosomes + + + align:start position:0% +chromosomes +telr + + align:start position:0% +telr + + + align:start position:0% +telr +um and every time at least certain cell + + align:start position:0% +um and every time at least certain cell + + + align:start position:0% +um and every time at least certain cell +families every time they reproduce they + + align:start position:0% +families every time they reproduce they + + + align:start position:0% +families every time they reproduce they +they lose one of + + align:start position:0% +they lose one of + + + align:start position:0% +they lose one of +those + + align:start position:0% +those + + + align:start position:0% +those +uh DNA unit at the end of the + + align:start position:0% +uh DNA unit at the end of the + + + align:start position:0% +uh DNA unit at the end of the +chromosome + + align:start position:0% +chromosome + + + align:start position:0% +chromosome +and that stops many cancers from growing + + align:start position:0% + + + + align:start position:0% + +because if the cancer cells lose their + + align:start position:0% +because if the cancer cells lose their + + + align:start position:0% +because if the cancer cells lose their +telemeters then + + align:start position:0% +telemeters then + + + align:start position:0% +telemeters then +ters uh then they can't reproduce for + + align:start position:0% +ters uh then they can't reproduce for + + + align:start position:0% +ters uh then they can't reproduce for +some reason but of course some of them + + align:start position:0% +some reason but of course some of them + + + align:start position:0% +some reason but of course some of them +find ways to reproduce without that + + align:start position:0% +find ways to reproduce without that + + + align:start position:0% +find ways to reproduce without that +mechanism whatever it does + + align:start position:0% +mechanism whatever it does + + + align:start position:0% +mechanism whatever it does +and so I bet there are a dozen groups + + align:start position:0% +and so I bet there are a dozen groups + + + align:start position:0% +and so I bet there are a dozen groups +working on Aging in the world but You' + + align:start position:0% +working on Aging in the world but You' + + + align:start position:0% +working on Aging in the world but You' +think it would be a lot more whatever + + align:start position:0% +think it would be a lot more whatever + + + align:start position:0% +think it would be a lot more whatever +the number + + align:start position:0% + + + + align:start position:0% + +is there's very small number of people + + align:start position:0% +is there's very small number of people + + + align:start position:0% +is there's very small number of people +working on cryonics which is can you + + align:start position:0% +working on cryonics which is can you + + + align:start position:0% +working on cryonics which is can you +freeze an animal and then uh revive + + align:start position:0% +freeze an animal and then uh revive + + + align:start position:0% +freeze an animal and then uh revive +it at some very long time in the future + + align:start position:0% +it at some very long time in the future + + + align:start position:0% +it at some very long time in the future +when + + align:start position:0% +when + + + align:start position:0% +when +uh when Medical Science has progressed + + align:start position:0% +uh when Medical Science has progressed + + + align:start position:0% +uh when Medical Science has progressed +to cure the disease that you would + + align:start position:0% +to cure the disease that you would + + + align:start position:0% +to cure the disease that you would +otherwise died of if you hadn't died of + + align:start position:0% +otherwise died of if you hadn't died of + + + align:start position:0% +otherwise died of if you hadn't died of +being + + align:start position:0% + + + + align:start position:0% + +frozen + + align:start position:0% +frozen + + + align:start position:0% +frozen +and in fact I think B I know that + + align:start position:0% +and in fact I think B I know that + + + align:start position:0% +and in fact I think B I know that +Benford has subscribed to such a + + align:start position:0% +Benford has subscribed to such a + + + align:start position:0% +Benford has subscribed to such a +service so the future might have some + + align:start position:0% +service so the future might have some + + + align:start position:0% +service so the future might have some +good science fiction + + align:start position:0% + + + + align:start position:0% + +writers more disasters + + align:start position:0% + + + + align:start position:0% + +what would happen if people did live 200 + + align:start position:0% +what would happen if people did live 200 + + + align:start position:0% +what would happen if people did live 200 +years in their present State then we + + align:start position:0% +years in their present State then we + + + align:start position:0% +years in their present State then we +would absolutely need robots + + align:start position:0% +would absolutely need robots + + + align:start position:0% +would absolutely need robots +because we wouldn't be able to hire + + align:start position:0% +because we wouldn't be able to hire + + + align:start position:0% +because we wouldn't be able to hire +enough foreigners to take care + + align:start position:0% +enough foreigners to take care + + + align:start position:0% +enough foreigners to take care +of care of them because the foreigners + + align:start position:0% +of care of them because the foreigners + + + align:start position:0% +of care of them because the foreigners +would be getting older + + align:start position:0% +would be getting older + + + align:start position:0% +would be getting older +too yes do we need robots if you replace + + align:start position:0% +too yes do we need robots if you replace + + + align:start position:0% +too yes do we need robots if you replace +our + + align:start position:0% +our + + + align:start position:0% +our +oral oh if you can if you can reverse + + align:start position:0% +oral oh if you can if you can reverse + + + align:start position:0% +oral oh if you can if you can reverse +aging or prevent aging then you don't + + align:start position:0% +aging or prevent aging then you don't + + + align:start position:0% +aging or prevent aging then you don't +need anything + + align:start position:0% +need anything + + + align:start position:0% +need anything +sure like at least we can produce + + align:start position:0% +sure like at least we can produce + + + align:start position:0% +sure like at least we can produce +I arms that are robot like robotic arms + + align:start position:0% +I arms that are robot like robotic arms + + + align:start position:0% +I arms that are robot like robotic arms +and they're like it's not the same as + + align:start position:0% +and they're like it's not the same as + + + align:start position:0% +and they're like it's not the same as +reverse engineering I don't know a li or + + align:start position:0% +reverse engineering I don't know a li or + + + align:start position:0% +reverse engineering I don't know a li or +something but well it's a nice question + + align:start position:0% +something but well it's a nice question + + + align:start position:0% +something but well it's a nice question +do + + align:start position:0% +do + + + align:start position:0% +do +it to cells wear out and like a brain + + align:start position:0% +it to cells wear out and like a brain + + + align:start position:0% +it to cells wear out and like a brain +cell can a brain cell continue to work + + align:start position:0% +cell can a brain cell continue to work + + + align:start position:0% +cell can a brain cell continue to work +for a thousand years or will it + + align:start position:0% +for a thousand years or will it + + + align:start position:0% +for a thousand years or will it +accumulate other non- gentic changes + + align:start position:0% +accumulate other non- gentic changes + + + align:start position:0% +accumulate other non- gentic changes +that nobody really + + align:start position:0% +that nobody really + + + align:start position:0% +that nobody really +knows of course you can you can grow + + align:start position:0% +knows of course you can you can grow + + + align:start position:0% +knows of course you can you can grow +bacteria for a thousand years but what's + + align:start position:0% +bacteria for a thousand years but what's + + + align:start position:0% +bacteria for a thousand years but what's +happening is + + align:start position:0% +happening is + + + align:start position:0% +happening is +there're they're not just uh aging + + align:start position:0% +there're they're not just uh aging + + + align:start position:0% +there're they're not just uh aging +they're + + align:start position:0% +they're + + + align:start position:0% +they're +evolving and so + + align:start position:0% +evolving and so + + + align:start position:0% +evolving and so +uh lots of them are do in fact die + + align:start position:0% +uh lots of them are do in fact die + + + align:start position:0% +uh lots of them are do in fact die +during this process and the survivors + + align:start position:0% +during this process and the survivors + + + align:start position:0% +during this process and the survivors +mutate or uh developed new genes and I'm + + align:start position:0% +mutate or uh developed new genes and I'm + + + align:start position:0% +mutate or uh developed new genes and I'm +sure if you take eoli and run it in + + align:start position:0% +sure if you take eoli and run it in + + + align:start position:0% +sure if you take eoli and run it in +bunch of test tubes for A Thousand + + align:start position:0% +bunch of test tubes for A Thousand + + + align:start position:0% +bunch of test tubes for A Thousand +Years it'll end up quite + + align:start position:0% +Years it'll end up quite + + + align:start position:0% +Years it'll end up quite +different so it's not clear that + + align:start position:0% +different so it's not clear that + + + align:start position:0% +different so it's not clear that +it in some sense it's not clear that + + align:start position:0% +it in some sense it's not clear that + + + align:start position:0% +it in some sense it's not clear that +it's + + align:start position:0% +it's + + + align:start position:0% +it's +Immortal there + + align:start position:0% +Immortal there + + + align:start position:0% +Immortal there +maybe every cell has some trace of a few + + align:start position:0% +maybe every cell has some trace of a few + + + align:start position:0% +maybe every cell has some trace of a few +atoms from the original one but it's not + + align:start position:0% +atoms from the original one but it's not + + + align:start position:0% +atoms from the original one but it's not +the whole structure yeah + + align:start position:0% +the whole structure yeah + + + align:start position:0% +the whole structure yeah +if we just get rejuvenating the cells + + align:start position:0% +if we just get rejuvenating the cells + + + align:start position:0% +if we just get rejuvenating the cells +and the Brain functioned for thousands + + align:start position:0% +and the Brain functioned for thousands + + + align:start position:0% +and the Brain functioned for thousands +of years um is it robust enough to do + + align:start position:0% +of years um is it robust enough to do + + + align:start position:0% +of years um is it robust enough to do +the memory management hold kind of the + + align:start position:0% +the memory management hold kind of the + + + align:start position:0% +the memory management hold kind of the +baggage of thousands of years and handle + + align:start position:0% +baggage of thousands of years and handle + + + align:start position:0% +baggage of thousands of years and handle +all that do we know I + + align:start position:0% +all that do we know I + + + align:start position:0% +all that do we know I +mean no one has the slightest idea uh + + align:start position:0% +mean no one has the slightest idea uh + + + align:start position:0% +mean no one has the slightest idea uh +they're pretty sure that memories are + + align:start position:0% +they're pretty sure that memories are + + + align:start position:0% +they're pretty sure that memories are +encoded in in synapses + + align:start position:0% + + + + align:start position:0% + +but as far as I know there's + + align:start position:0% +but as far as I know there's + + + align:start position:0% +but as far as I know there's +this Neuroscience has a sort of vacuum + + align:start position:0% +this Neuroscience has a sort of vacuum + + + align:start position:0% +this Neuroscience has a sort of vacuum +in + + align:start position:0% +in + + + align:start position:0% +in +between uh the knowledge about + + align:start position:0% +between uh the knowledge about + + + align:start position:0% +between uh the knowledge about +individual + + align:start position:0% +individual + + + align:start position:0% +individual +cells and + + align:start position:0% + + + + align:start position:0% + +the larger structures that remember + + align:start position:0% +the larger structures that remember + + + align:start position:0% +the larger structures that remember +symbolic things for + + align:start position:0% +symbolic things for + + + align:start position:0% +symbolic things for +example so they know enough about + + align:start position:0% +example so they know enough about + + + align:start position:0% +example so they know enough about +sinapsis in very simple animals well uh + + align:start position:0% + + + + align:start position:0% + +what was uh David's conclusion last + + align:start position:0% + + + + align:start position:0% + +time do we + + align:start position:0% +time do we + + + align:start position:0% +time do we +know the encoding of any particular + + align:start position:0% +know the encoding of any particular + + + align:start position:0% +know the encoding of any particular +reflex learn thing in the uh that little + + align:start position:0% +reflex learn thing in the uh that little + + + align:start position:0% +reflex learn thing in the uh that little +worm uh there's basically only only two + + align:start position:0% +worm uh there's basically only only two + + + align:start position:0% +worm uh there's basically only only two +things that we only two encodings that + + align:start position:0% +things that we only two encodings that + + + align:start position:0% +things that we only two encodings that +we completely understand from start to + + align:start position:0% +we completely understand from start to + + + align:start position:0% +we completely understand from start to +finish in any any system as far as I + + align:start position:0% +finish in any any system as far as I + + + align:start position:0% +finish in any any system as far as I +know uh one is the uh Patell tendon + + align:start position:0% +know uh one is the uh Patell tendon + + + align:start position:0% +know uh one is the uh Patell tendon +reflex and the knee-jerk reflex and the + + align:start position:0% +reflex and the knee-jerk reflex and the + + + align:start position:0% +reflex and the knee-jerk reflex and the +other is the Gil retraction reflex in um + + align:start position:0% +other is the Gil retraction reflex in um + + + align:start position:0% +other is the Gil retraction reflex in um +aesia what's the MIT Professor who + + align:start position:0% +aesia what's the MIT Professor who + + + align:start position:0% +aesia what's the MIT Professor who +mapped out the uh motor control of the + + align:start position:0% +mapped out the uh motor control of the + + + align:start position:0% +mapped out the uh motor control of the +frog + + align:start position:0% +frog + + + align:start position:0% +frog +leg does it bitsy what left perhaps no I + + align:start position:0% +leg does it bitsy what left perhaps no I + + + align:start position:0% +leg does it bitsy what left perhaps no I +think bitsy what's his + + align:start position:0% +think bitsy what's his + + + align:start position:0% +think bitsy what's his +name he is the frog has a sort of + + align:start position:0% +name he is the frog has a sort of + + + align:start position:0% +name he is the frog has a sort of +cerebellum like two-dimensional + + align:start position:0% +cerebellum like two-dimensional + + + align:start position:0% +cerebellum like two-dimensional +structure and they've + + align:start position:0% +structure and they've + + + align:start position:0% +structure and they've +mapped one looks like aland + + align:start position:0% + + + + align:start position:0% + +B oh no that that was a while actually + + align:start position:0% +B oh no that that was a while actually + + + align:start position:0% +B oh no that that was a while actually +that's he's figured out the + + align:start position:0% +that's he's figured out the + + + align:start position:0% +that's he's figured out the +wiring no I'm I'm mistaken he's figured + + align:start position:0% +wiring no I'm I'm mistaken he's figured + + + align:start position:0% +wiring no I'm I'm mistaken he's figured +out the wiring of the uh motor control + + align:start position:0% +out the wiring of the uh motor control + + + align:start position:0% +out the wiring of the uh motor control +control of the leg but but it's not + + align:start position:0% +control of the leg but but it's not + + + align:start position:0% +control of the leg but but it's not +learned it's so the the anatomy is clear + + align:start position:0% +learned it's so the the anatomy is clear + + + align:start position:0% +learned it's so the the anatomy is clear +enough that you can see uh how when it + + align:start position:0% +enough that you can see uh how when it + + + align:start position:0% +enough that you can see uh how when it +wants to turn left it moves the two legs + + align:start position:0% +wants to turn left it moves the two legs + + + align:start position:0% +wants to turn left it moves the two legs +in the right way something that's that's + + align:start position:0% +in the right way something that's that's + + + align:start position:0% +in the right way something that's that's +about as far as I think anyone's got so + + align:start position:0% +about as far as I think anyone's got so + + + align:start position:0% +about as far as I think anyone's got so +that's the functional wiring but not not + + align:start position:0% +that's the functional wiring but not not + + + align:start position:0% +that's the functional wiring but not not +with some learning right + + align:start position:0% + + + + align:start position:0% + +but I suspect what'll happen is + + align:start position:0% +but I suspect what'll happen is + + + align:start position:0% +but I suspect what'll happen is +that it won't be so terribly hard + + align:start position:0% +that it won't be so terribly hard + + + align:start position:0% +that it won't be so terribly hard +to uh implant artificial uh gigabytes of + + align:start position:0% +to uh implant artificial uh gigabytes of + + + align:start position:0% +to uh implant artificial uh gigabytes of +memory in parts of the human brain and + + align:start position:0% +memory in parts of the human brain and + + + align:start position:0% +memory in parts of the human brain and +and get people to learn how to operate + + align:start position:0% +and get people to learn how to operate + + + align:start position:0% +and get people to learn how to operate +it you can maintain skin cells for a + + align:start position:0% +it you can maintain skin cells for a + + + align:start position:0% +it you can maintain skin cells for a +thousand years why not your right and + + align:start position:0% +thousand years why not your right and + + + align:start position:0% +thousand years why not your right and +we'll be able to do that before we know + + align:start position:0% +we'll be able to do that before we know + + + align:start position:0% +we'll be able to do that before we know +how the human memory works we'll know + + align:start position:0% +how the human memory works we'll know + + + align:start position:0% +how the human memory works we'll know +all about it how the nanot technology + + align:start position:0% +all about it how the nanot technology + + + align:start position:0% +all about it how the nanot technology +uh Rams work + + align:start position:0% + + + + align:start position:0% + +but and then maybe you can work + + align:start position:0% +but and then maybe you can work + + + align:start position:0% +but and then maybe you can work +backwards seeing the kind of mistakes + + align:start position:0% +backwards seeing the kind of mistakes + + + align:start position:0% +backwards seeing the kind of mistakes +you make if when you try try to + + align:start position:0% + + + + align:start position:0% + +corrected well I want a new disaster + + align:start position:0% + + + + align:start position:0% + +you've got meteors right what's that + + align:start position:0% +you've got meteors right what's that + + + align:start position:0% +you've got meteors right what's that +meteors yes meteors and and volcanoes + + align:start position:0% +meteors yes meteors and and volcanoes + + + align:start position:0% +meteors yes meteors and and volcanoes +and those and there's a nice book by + + align:start position:0% +and those and there's a nice book by + + + align:start position:0% +and those and there's a nice book by +Martin Reese which is cheerfully called + + align:start position:0% +Martin Reese which is cheerfully called + + + align:start position:0% +Martin Reese which is cheerfully called +our final + + align:start position:0% +our final + + + align:start position:0% +our final +hour Martin Reese is very good + + align:start position:0% +hour Martin Reese is very good + + + align:start position:0% +hour Martin Reese is very good +astronomer in + + align:start position:0% +astronomer in + + + align:start position:0% +astronomer in +England who has the title of astronomer + + align:start position:0% +England who has the title of astronomer + + + align:start position:0% +England who has the title of astronomer +Royal + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +uh so he he's discussing mostly uh + + align:start position:0% +uh so he he's discussing mostly uh + + + align:start position:0% +uh so he he's discussing mostly uh +physics type disasters and I was trying + + align:start position:0% +physics type disasters and I was trying + + + align:start position:0% +physics type disasters and I was trying +to extend it + + align:start position:0% + + + + align:start position:0% + +to you know how do you make a religion + + align:start position:0% +to you know how do you make a religion + + + align:start position:0% +to you know how do you make a religion +that sucks everybody in + + align:start position:0% +that sucks everybody in + + + align:start position:0% +that sucks everybody in +or a logical argument that makes + + align:start position:0% +or a logical argument that makes + + + align:start position:0% +or a logical argument that makes +everyone into a + + align:start position:0% +everyone into a + + + align:start position:0% +everyone into a +terrorist that's what the terror ists + + align:start position:0% +terrorist that's what the terror ists + + + align:start position:0% +terrorist that's what the terror ists +are looking for + + align:start position:0% +are looking for + + + align:start position:0% +are looking for +and I suppose there's a remote chance + + align:start position:0% +and I suppose there's a remote chance + + + align:start position:0% +and I suppose there's a remote chance +that + + align:start position:0% +that + + + align:start position:0% +that +uh some philosopher will think of + + align:start position:0% +uh some philosopher will think of + + + align:start position:0% +uh some philosopher will think of +something new one of these + + align:start position:0% + + + + align:start position:0% + +days forg makes everyone's life savings + + align:start position:0% +days forg makes everyone's life savings + + + align:start position:0% +days forg makes everyone's life savings +disappear perhaps that's + + align:start position:0% +disappear perhaps that's + + + align:start position:0% +disappear perhaps that's +enough what will they do get angry I + + align:start position:0% +enough what will they do get angry I + + + align:start position:0% +enough what will they do get angry I +suppose + + align:start position:0% + + + + align:start position:0% + +you mustn't tax the rich because then + + align:start position:0% +you mustn't tax the rich because then + + + align:start position:0% +you mustn't tax the rich because then +there won't be any job + + align:start position:0% +there won't be any job + + + align:start position:0% +there won't be any job +creators I love the new kind of logic + + align:start position:0% +creators I love the new kind of logic + + + align:start position:0% +creators I love the new kind of logic +appears every month with + + align:start position:0% +appears every month with + + + align:start position:0% +appears every month with +the uh are there any countries with + + align:start position:0% +the uh are there any countries with + + + align:start position:0% +the uh are there any countries with +three parties + + align:start position:0% +three parties + + + align:start position:0% +three parties +oh there countries with three parties + + align:start position:0% +oh there countries with three parties + + + align:start position:0% +oh there countries with three parties +who has three + + align:start position:0% +who has three + + + align:start position:0% +who has three +parties only how does England + + align:start position:0% +parties only how does England + + + align:start position:0% +parties only how does England +work labor social + + align:start position:0% + + + + align:start position:0% + +are there other countries with just two + + align:start position:0% +are there other countries with just two + + + align:start position:0% +are there other countries with just two +parties seems crazy to have two + + align:start position:0% + + + + align:start position:0% + +parties yeah I think two parties have + + align:start position:0% +parties yeah I think two parties have + + + align:start position:0% +parties yeah I think two parties have +much less common than three or more two + + align:start position:0% +much less common than three or more two + + + align:start position:0% +much less common than three or more two +parties is weird they're almost always + + align:start position:0% +parties is weird they're almost always + + + align:start position:0% +parties is weird they're almost always +three or more or + + align:start position:0% + + + + align:start position:0% + +one say it again three there almost + + align:start position:0% +one say it again three there almost + + + align:start position:0% +one say it again three there almost +always three or more or one or one well + + align:start position:0% +always three or more or one or one well + + + align:start position:0% +always three or more or one or one well +Australia is pretty close to two parties + + align:start position:0% +Australia is pretty close to two parties + + + align:start position:0% +Australia is pretty close to two parties +it's like two a third + + align:start position:0% +it's like two a third + + + align:start position:0% +it's like two a third +party a third party + + align:start position:0% +party a third party + + + align:start position:0% +party a third party +yeah ah a very tiny just a few people + + align:start position:0% +yeah ah a very tiny just a few people + + + align:start position:0% +yeah ah a very tiny just a few people +who can be + + align:start position:0% +who can be + + + align:start position:0% +who can be +moved that's right in England my Uncle + + align:start position:0% +moved that's right in England my Uncle + + + align:start position:0% +moved that's right in England my Uncle +Harry is famous for the dogs rights + + align:start position:0% +Harry is famous for the dogs rights + + + align:start position:0% +Harry is famous for the dogs rights +party of which he and his wife are the + + align:start position:0% +party of which he and his wife are the + + + align:start position:0% +party of which he and his wife are the +only + + align:start position:0% + + + + align:start position:0% + +members well there's this meme that goes + + align:start position:0% +members well there's this meme that goes + + + align:start position:0% +members well there's this meme that goes +around that if you're trying to vote for + + align:start position:0% +around that if you're trying to vote for + + + align:start position:0% +around that if you're trying to vote for +the third party in the United States + + align:start position:0% +the third party in the United States + + + align:start position:0% +the third party in the United States +that you're wasting your + + align:start position:0% +that you're wasting your + + + align:start position:0% +that you're wasting your +vote Yes kind of a destructive idea that + + align:start position:0% +vote Yes kind of a destructive idea that + + + align:start position:0% +vote Yes kind of a destructive idea that +keeps it with two + + align:start position:0% +keeps it with two + + + align:start position:0% +keeps it with two +parties they have the same thing in + + align:start position:0% +parties they have the same thing in + + + align:start position:0% +parties they have the same thing in +England for a long time until in the + + align:start position:0% +England for a long time until in the + + + align:start position:0% +England for a long time until in the +last election they actually the liberal + + align:start position:0% +last election they actually the liberal + + + align:start position:0% +last election they actually the liberal +Democrats + + align:start position:0% +Democrats + + + align:start position:0% +Democrats +of they became third party so nowadays + + align:start position:0% +of they became third party so nowadays + + + align:start position:0% +of they became third party so nowadays +has three parties but it took uh 15 + + align:start position:0% +has three parties but it took uh 15 + + + align:start position:0% +has three parties but it took uh 15 +years well I know people who are still + + align:start position:0% +years well I know people who are still + + + align:start position:0% +years well I know people who are still +mad at Ralph + + align:start position:0% +mad at Ralph + + + align:start position:0% +mad at Ralph +nater because + + align:start position:0% + + + + align:start position:0% + +because the + + align:start position:0% +because the + + + align:start position:0% +because the +bush thing came with a very small number + + align:start position:0% +bush thing came with a very small number + + + align:start position:0% +bush thing came with a very small number +of the nater votes could have shifted + + align:start position:0% + + + + align:start position:0% + +it how about something like this for + + align:start position:0% +it how about something like this for + + + align:start position:0% +it how about something like this for +nater sent me a book the other day great + + align:start position:0% +nater sent me a book the other day great + + + align:start position:0% +nater sent me a book the other day great +big book with about a dozen smart people + + align:start position:0% +big book with about a dozen smart people + + + align:start position:0% +big book with about a dozen smart people +discussing politics I haven't opened it + + align:start position:0% +discussing politics I haven't opened it + + + align:start position:0% +discussing politics I haven't opened it +yet + + align:start position:0% + + + + align:start position:0% + +do you have anything on your + + align:start position:0% +do you have anything on your + + + align:start position:0% +do you have anything on your +list that uh plays on the good all the + + align:start position:0% +list that uh plays on the good all the + + + align:start position:0% +list that uh plays on the good all the +genetic stuff such as + + align:start position:0% +genetic stuff such as + + + align:start position:0% +genetic stuff such as +um for example you find out that people + + align:start position:0% +um for example you find out that people + + + align:start position:0% +um for example you find out that people +who have blue + + align:start position:0% +who have blue + + + align:start position:0% +who have blue +eyes have some uh genetic thing that + + align:start position:0% +eyes have some uh genetic thing that + + + align:start position:0% +eyes have some uh genetic thing that +makes them inferior in the long run and + + align:start position:0% +makes them inferior in the long run and + + + align:start position:0% +makes them inferior in the long run and +so they should be eradicated from the + + align:start position:0% +so they should be eradicated from the + + + align:start position:0% +so they should be eradicated from the +population of the Earth in the interests + + align:start position:0% +population of the Earth in the interests + + + align:start position:0% +population of the Earth in the interests +of humankind and people who have a what + + align:start position:0% +of humankind and people who have a what + + + align:start position:0% +of humankind and people who have a what +who have blue eyes for example and um + + align:start position:0% +who have blue eyes for example and um + + + align:start position:0% +who have blue eyes for example and um +then of course they wouldn't be happy + + align:start position:0% +then of course they wouldn't be happy + + + align:start position:0% +then of course they wouldn't be happy +with this and this would create a + + align:start position:0% +with this and this would create a + + + align:start position:0% +with this and this would create a +polarizing effect of the global + + align:start position:0% +polarizing effect of the global + + + align:start position:0% +polarizing effect of the global +population as a whole and they kill off + + align:start position:0% +population as a whole and they kill off + + + align:start position:0% +population as a whole and they kill off +each + + align:start position:0% + + + + align:start position:0% + +other I think this is something that + + align:start position:0% +other I think this is something that + + + align:start position:0% +other I think this is something that +should come up + + align:start position:0% +should come up + + + align:start position:0% +should come up +well how did Hitler get this Aran thing + + align:start position:0% +well how did Hitler get this Aran thing + + + align:start position:0% +well how did Hitler get this Aran thing +to be so popular + + align:start position:0% +to be so popular + + + align:start position:0% +to be so popular +anybody understand the psychology + + align:start position:0% +anybody understand the psychology + + + align:start position:0% +anybody understand the psychology +of + + align:start position:0% + + + + align:start position:0% + +Nazism + + align:start position:0% + + + + align:start position:0% + +because wasn't there something about + + align:start position:0% +because wasn't there something about + + + align:start position:0% +because wasn't there something about +being blonde and not very many Germans + + align:start position:0% +being blonde and not very many Germans + + + align:start position:0% +being blonde and not very many Germans +are actually blonde so how did he pull + + align:start position:0% +are actually blonde so how did he pull + + + align:start position:0% +are actually blonde so how did he pull +this thing off + + align:start position:0% + + + + align:start position:0% + +Eugenics and you race sciences and + + align:start position:0% +Eugenics and you race sciences and + + + align:start position:0% +Eugenics and you race sciences and +things were really popular at that time + + align:start position:0% +things were really popular at that time + + + align:start position:0% +things were really popular at that time +not just in Germany and in particular a + + align:start position:0% +not just in Germany and in particular a + + + align:start position:0% +not just in Germany and in particular a +lot of what you see coming out that + + align:start position:0% +lot of what you see coming out that + + + align:start position:0% +lot of what you see coming out that +proves one thing or another are + + align:start position:0% +proves one thing or another are + + + align:start position:0% +proves one thing or another are +basically uh misunderstanding + + align:start position:0% +basically uh misunderstanding + + + align:start position:0% +basically uh misunderstanding +correlation with causation good lot of + + align:start position:0% +correlation with causation good lot of + + + align:start position:0% +correlation with causation good lot of +those studies I mean there's also a lot + + align:start position:0% +those studies I mean there's also a lot + + + align:start position:0% +those studies I mean there's also a lot +of like purposeful government back re + + align:start position:0% +of like purposeful government back re + + + align:start position:0% +of like purposeful government back re +research and things like that had a + + align:start position:0% +research and things like that had a + + + align:start position:0% +research and things like that had a +specific agenda um especially when you + + align:start position:0% +specific agenda um especially when you + + + align:start position:0% +specific agenda um especially when you +get into Nazi Germany + + align:start position:0% +get into Nazi Germany + + + align:start position:0% +get into Nazi Germany +but that's that's just from that side + + align:start position:0% +but that's that's just from that side + + + align:start position:0% +but that's that's just from that side +you you also have lots of other things + + align:start position:0% +you you also have lots of other things + + + align:start position:0% +you you also have lots of other things +like the position Germany was in and + + align:start position:0% +like the position Germany was in and + + + align:start position:0% +like the position Germany was in and +people wanting to scapegoat + + align:start position:0% +people wanting to scapegoat + + + align:start position:0% +people wanting to scapegoat +and + + align:start position:0% +and + + + align:start position:0% +and +social uh social and cultural ideas um + + align:start position:0% +social uh social and cultural ideas um + + + align:start position:0% +social uh social and cultural ideas um +yeah not really just the Eugenics that + + align:start position:0% +yeah not really just the Eugenics that + + + align:start position:0% +yeah not really just the Eugenics that +were being looked into at that point + + align:start position:0% +were being looked into at that point + + + align:start position:0% +were being looked into at that point +mhm so that was just one feature at some + + align:start position:0% +mhm so that was just one feature at some + + + align:start position:0% +mhm so that was just one feature at some +particular period period of the + + align:start position:0% +particular period period of the + + + align:start position:0% +particular period period of the +evolution of the thing but there is also + + align:start position:0% +evolution of the thing but there is also + + + align:start position:0% +evolution of the thing but there is also +maybe it was at the beginning when if + + align:start position:0% +maybe it was at the beginning when if + + + align:start position:0% +maybe it was at the beginning when if +you could just get all the blonde people + + align:start position:0% +you could just get all the blonde people + + + align:start position:0% +you could just get all the blonde people +that would give you a start and then you + + align:start position:0% +that would give you a start and then you + + + align:start position:0% +that would give you a start and then you +could broaden it out no they really look + + align:start position:0% +could broaden it out no they really look + + + align:start position:0% +could broaden it out no they really look +back to the Huns were supposedly of + + align:start position:0% +back to the Huns were supposedly of + + + align:start position:0% +back to the Huns were supposedly of +Nordic + + align:start position:0% +Nordic + + + align:start position:0% +Nordic +descent the German culture is pretty + + align:start position:0% +descent the German culture is pretty + + + align:start position:0% +descent the German culture is pretty +thick with the Nordic mythology as well + + align:start position:0% +thick with the Nordic mythology as well + + + align:start position:0% +thick with the Nordic mythology as well +so they feel like there's a connection + + align:start position:0% +so they feel like there's a connection + + + align:start position:0% +so they feel like there's a connection +even not all + + align:start position:0% +even not all + + + align:start position:0% +even not all +blond just think we could breed we could + + align:start position:0% +blond just think we could breed we could + + + align:start position:0% +blond just think we could breed we could +back breed them and + + align:start position:0% + + + + align:start position:0% + +if we had + + align:start position:0% +if we had + + + align:start position:0% +if we had +a with enough correlation we could make + + align:start position:0% +a with enough correlation we could make + + + align:start position:0% +a with enough correlation we could make +a hun be great + + align:start position:0% +a hun be great + + + align:start position:0% +a hun be great +project yeah so people tend to divide + + align:start position:0% +project yeah so people tend to divide + + + align:start position:0% +project yeah so people tend to divide +themselves into groups and hate like + + align:start position:0% +themselves into groups and hate like + + + align:start position:0% +themselves into groups and hate like +kind of hate the other like the sports + + align:start position:0% +kind of hate the other like the sports + + + align:start position:0% +kind of hate the other like the sports +industry is based on that which industry + + align:start position:0% +industry is based on that which industry + + + align:start position:0% +industry is based on that which industry +sparts industry oh so there are like a + + align:start position:0% +sparts industry oh so there are like a + + + align:start position:0% +sparts industry oh so there are like a +team of people that you don't even know + + align:start position:0% +team of people that you don't even know + + + align:start position:0% +team of people that you don't even know +and you don't care and you cheer for + + align:start position:0% +and you don't care and you cheer for + + + align:start position:0% +and you don't care and you cheer for +them to like beat the other team and + + align:start position:0% +them to like beat the other team and + + + align:start position:0% +them to like beat the other team and +that's kind of irrational and like there + + align:start position:0% +that's kind of irrational and like there + + + align:start position:0% +that's kind of irrational and like there +are some studies I think it's like this + + align:start position:0% +are some studies I think it's like this + + + align:start position:0% +are some studies I think it's like this +it's called Stanford study that like + + align:start position:0% +it's called Stanford study that like + + + align:start position:0% +it's called Stanford study that like +they put some students into a prison and + + align:start position:0% +they put some students into a prison and + + + align:start position:0% +they put some students into a prison and +some of them act as the police officers + + align:start position:0% +some of them act as the police officers + + + align:start position:0% +some of them act as the police officers +and some as prisoners and then they tend + + align:start position:0% +and some as prisoners and then they tend + + + align:start position:0% +and some as prisoners and then they tend +to divide each other uh and so like the + + align:start position:0% +to divide each other uh and so like the + + + align:start position:0% +to divide each other uh and so like the +prisoners start hating the police and + + align:start position:0% +prisoners start hating the police and + + + align:start position:0% +prisoners start hating the police and +the police start uh acting more like + + align:start position:0% +the police start uh acting more like + + + align:start position:0% +the police start uh acting more like +violently + + align:start position:0% +violently + + + align:start position:0% +violently +and so if you + + align:start position:0% +and so if you + + + align:start position:0% +and so if you +merchandise uh say like if you say to + + align:start position:0% +merchandise uh say like if you say to + + + align:start position:0% +merchandise uh say like if you say to +people we are as a group better people + + align:start position:0% +people we are as a group better people + + + align:start position:0% +people we are as a group better people +tend to believe that and tend to hate + + align:start position:0% +tend to believe that and tend to hate + + + align:start position:0% +tend to believe that and tend to hate +another group and is independent of like + + align:start position:0% +another group and is independent of like + + + align:start position:0% +another group and is independent of like +how the groups formed + + align:start position:0% +how the groups formed + + + align:start position:0% +how the groups formed +so it's just how we are we tend toight + + align:start position:0% +so it's just how we are we tend toight + + + align:start position:0% +so it's just how we are we tend toight +into groups and hey could we invent a + + align:start position:0% +into groups and hey could we invent a + + + align:start position:0% +into groups and hey could we invent a +sport to see if football players are + + align:start position:0% +sport to see if football players are + + + align:start position:0% +sport to see if football players are +better or worse than basketball + + align:start position:0% + + + + align:start position:0% + +players I would love to invent something + + align:start position:0% +players I would love to invent something + + + align:start position:0% +players I would love to invent something +that undermines this whole Sports Thing + + align:start position:0% +that undermines this whole Sports Thing + + + align:start position:0% +that undermines this whole Sports Thing +by getting a real serious argument about + + align:start position:0% +by getting a real serious argument about + + + align:start position:0% +by getting a real serious argument about +which sport is better but you might just + + align:start position:0% +which sport is better but you might just + + + align:start position:0% +which sport is better but you might just +create like an Uber sport it might go + + align:start position:0% +create like an Uber sport it might go + + + align:start position:0% +create like an Uber sport it might go +terribly wrong yeah I suspected that + + align:start position:0% +terribly wrong yeah I suspected that + + + align:start position:0% +terribly wrong yeah I suspected that +would + + align:start position:0% +would + + + align:start position:0% +would +backfire what was your keyword like an + + align:start position:0% +backfire what was your keyword like an + + + align:start position:0% +backfire what was your keyword like an +Uber sport yeah like a the sport that + + align:start position:0% +Uber sport yeah like a the sport that + + + align:start position:0% +Uber sport yeah like a the sport that +Conquer All Sports yeah did you have + + align:start position:0% +Conquer All Sports yeah did you have + + + align:start position:0% +Conquer All Sports yeah did you have +that yet no an Uber + + align:start position:0% + + + + align:start position:0% + +profession and on the World + + align:start position:0% + + + + align:start position:0% + +Sports well just imagine working in an + + align:start position:0% +Sports well just imagine working in an + + + align:start position:0% +Sports well just imagine working in an +employment + + align:start position:0% +employment + + + align:start position:0% +employment +agency there you're not + + align:start position:0% +agency there you're not + + + align:start position:0% +agency there you're not +doing maybe you're inventing jobs and + + align:start position:0% +doing maybe you're inventing jobs and + + + align:start position:0% +doing maybe you're inventing jobs and +you don't realize that you have an Uber + + align:start position:0% +you don't realize that you have an Uber + + + align:start position:0% +you don't realize that you have an Uber +job of some + + align:start position:0% +job of some + + + align:start position:0% +job of some +sort it's the Republic + + align:start position:0% +sort it's the Republic + + + align:start position:0% +sort it's the Republic +argument that you shouldn't tax people + + align:start position:0% +argument that you shouldn't tax people + + + align:start position:0% +argument that you shouldn't tax people +because they're the job creators it's + + align:start position:0% +because they're the job creators it's + + + align:start position:0% +because they're the job creators it's +just such a strange argument + + align:start position:0% + + + + align:start position:0% + +because + + align:start position:0% + + + + align:start position:0% + +when when Patrick and I were running the + + align:start position:0% +when when Patrick and I were running the + + + align:start position:0% +when when Patrick and I were running the +AI lab we had a great + + align:start position:0% + + + + align:start position:0% + +uh guy in charge of engineering + + align:start position:0% +uh guy in charge of engineering + + + align:start position:0% +uh guy in charge of engineering +and we were arguing about jobs and he + + align:start position:0% +and we were arguing about jobs and he + + + align:start position:0% +and we were arguing about jobs and he +said if you want jobs why don't you just + + align:start position:0% +said if you want jobs why don't you just + + + align:start position:0% +said if you want jobs why don't you just +get a very long rope and put a million + + align:start position:0% +get a very long rope and put a million + + + align:start position:0% +get a very long rope and put a million +people at each + + align:start position:0% + + + + align:start position:0% + +end and see + + align:start position:0% +end and see + + + align:start position:0% +end and see +see who can who can pull the + + align:start position:0% +see who can who can pull the + + + align:start position:0% +see who can who can pull the +other who can pull the other across the + + align:start position:0% +other who can pull the other across the + + + align:start position:0% +other who can pull the other across the +Mississippi + + align:start position:0% +Mississippi + + + align:start position:0% +Mississippi +and because + + align:start position:0% +and because + + + align:start position:0% +and because +football + + align:start position:0% +football + + + align:start position:0% +football +yeah basketball players go + + align:start position:0% +yeah basketball players go + + + align:start position:0% +yeah basketball players go +jump and I was just turned on the radio + + align:start position:0% +jump and I was just turned on the radio + + + align:start position:0% +jump and I was just turned on the radio +this morning with and this casino is + + align:start position:0% +this morning with and this casino is + + + align:start position:0% +this morning with and this casino is +going to create 3,000 jobs it said + + align:start position:0% +going to create 3,000 jobs it said + + + align:start position:0% +going to create 3,000 jobs it said +and isn't that just like the + + align:start position:0% + + + + align:start position:0% + +rope that is these people are not + + align:start position:0% +rope that is these people are not + + + align:start position:0% +rope that is these people are not +actually doing anything except taking + + align:start position:0% +actually doing anything except taking + + + align:start position:0% +actually doing anything except taking +money from the poor or isn't Wall Street + + align:start position:0% +money from the poor or isn't Wall Street + + + align:start position:0% +money from the poor or isn't Wall Street +doing that but to smart people well yes + + align:start position:0% +doing that but to smart people well yes + + + align:start position:0% +doing that but to smart people well yes +and the tragedy is that + + align:start position:0% +and the tragedy is that + + + align:start position:0% +and the tragedy is that +I've been through this a hundred times + + align:start position:0% +I've been through this a hundred times + + + align:start position:0% +I've been through this a hundred times +but when I was a young + + align:start position:0% +but when I was a young + + + align:start position:0% +but when I was a young +Professor all the students became + + align:start position:0% +Professor all the students became + + + align:start position:0% +Professor all the students became +professors and there was a there see + + align:start position:0% +professors and there was a there see + + + align:start position:0% +professors and there was a there see +there seemed to be a point to it + + align:start position:0% +there seemed to be a point to it + + + align:start position:0% +there seemed to be a point to it +all but um around 1980 things started + + align:start position:0% +all but um around 1980 things started + + + align:start position:0% +all but um around 1980 things started +flattening out in American + + align:start position:0% +flattening out in American + + + align:start position:0% +flattening out in American +universities stopped + + align:start position:0% +universities stopped + + + align:start position:0% +universities stopped +expanding and I think it's partly that + + align:start position:0% +expanding and I think it's partly that + + + align:start position:0% +expanding and I think it's partly that +the + + align:start position:0% +the + + + align:start position:0% +the +life you know the lifespan has extended + + align:start position:0% +life you know the lifespan has extended + + + align:start position:0% +life you know the lifespan has extended +one year every + + align:start position:0% +one year every + + + align:start position:0% +one year every +four + + align:start position:0% + + + + align:start position:0% + +so uh you don't need new professors very + + align:start position:0% +so uh you don't need new professors very + + + align:start position:0% +so uh you don't need new professors very +often and the universities haven't grown + + align:start position:0% +often and the universities haven't grown + + + align:start position:0% +often and the universities haven't grown +so almost all my first students were are + + align:start position:0% +so almost all my first students were are + + + align:start position:0% +so almost all my first students were are +professors and almost all the recent + + align:start position:0% +professors and almost all the recent + + + align:start position:0% +professors and almost all the recent +ones aren't and a lot of them are in + + align:start position:0% +ones aren't and a lot of them are in + + + align:start position:0% +ones aren't and a lot of them are in +Wall + + align:start position:0% +Wall + + + align:start position:0% +Wall +Street so what can we do + + align:start position:0% + + + + align:start position:0% + +regulate W streate properly maybe you + + align:start position:0% +regulate W streate properly maybe you + + + align:start position:0% +regulate W streate properly maybe you +should tax people if their IQ is high + + align:start position:0% +should tax people if their IQ is high + + + align:start position:0% +should tax people if their IQ is high +and they make more + + align:start position:0% + + + + align:start position:0% + +money a mathematician could work that + + align:start position:0% +money a mathematician could work that + + + align:start position:0% +money a mathematician could work that +out + + align:start position:0% +out + + + align:start position:0% +out +and some people work at getting the + + align:start position:0% +and some people work at getting the + + + align:start position:0% +and some people work at getting the +highest IQ they could but not too high + + align:start position:0% +highest IQ they could but not too high + + + align:start position:0% +highest IQ they could but not too high +we passed not too high yes or just + + align:start position:0% +we passed not too high yes or just + + + align:start position:0% +we passed not too high yes or just +taking the test + + align:start position:0% +taking the test + + + align:start position:0% +taking the test +to show that I + + align:start position:0% + + + + align:start position:0% + +doesn't I mean a lot of that oil sounds + + align:start position:0% +doesn't I mean a lot of that oil sounds + + + align:start position:0% +doesn't I mean a lot of that oil sounds +pretty simple economics you can make or + + align:start position:0% +pretty simple economics you can make or + + + align:start position:0% +pretty simple economics you can make or +people can make a lot of money at Wall + + align:start position:0% +people can make a lot of money at Wall + + + align:start position:0% +people can make a lot of money at Wall +Street and the system is set up such + + align:start position:0% +Street and the system is set up such + + + align:start position:0% +Street and the system is set up such +that that's fairly doable for a large + + align:start position:0% +that that's fairly doable for a large + + + align:start position:0% +that that's fairly doable for a large +number of people and it's really really + + align:start position:0% +number of people and it's really really + + + align:start position:0% +number of people and it's really really +hard to get jobs as + + align:start position:0% + + + + align:start position:0% + +professors but if there was more money + + align:start position:0% +professors but if there was more money + + + align:start position:0% +professors but if there was more money +in research I imagine you would see a + + align:start position:0% +in research I imagine you would see a + + + align:start position:0% +in research I imagine you would see a +lot more people doing research if they + + align:start position:0% +lot more people doing research if they + + + align:start position:0% +lot more people doing research if they +made enough money the right reason to + + align:start position:0% +made enough money the right reason to + + + align:start position:0% +made enough money the right reason to +can they if you make enough money can + + align:start position:0% +can they if you make enough money can + + + align:start position:0% +can they if you make enough money can +you buy a + + align:start position:0% +you buy a + + + align:start position:0% +you buy a +professorship yeah no you can start your + + align:start position:0% +professorship yeah no you can start your + + + align:start position:0% +professorship yeah no you can start your +own lab yeah that's + + align:start position:0% +own lab yeah that's + + + align:start position:0% +own lab yeah that's +true but then you're inclined not to + + align:start position:0% +true but then you're inclined not to + + + align:start position:0% +true but then you're inclined not to +publish you if you if you actually do + + align:start position:0% +publish you if you if you actually do + + + align:start position:0% +publish you if you if you actually do +anything good and you keep it a + + align:start position:0% + + + + align:start position:0% + +secret well how many of you want to be a + + align:start position:0% +secret well how many of you want to be a + + + align:start position:0% +secret well how many of you want to be a +professor + + align:start position:0% + + + + align:start position:0% + +it's fun you don't have to do + + align:start position:0% + + + + align:start position:0% + +anything gives all the more reason to do + + align:start position:0% + + + + align:start position:0% + +things I I also have heard that um in in + + align:start position:0% +things I I also have heard that um in in + + + align:start position:0% +things I I also have heard that um in in +the past you had to deal with I guess + + align:start position:0% +the past you had to deal with I guess + + + align:start position:0% +the past you had to deal with I guess +maybe less of the admin in political + + align:start position:0% +maybe less of the admin in political + + + align:start position:0% +maybe less of the admin in political +sort of you have to do nowadays as + + align:start position:0% +sort of you have to do nowadays as + + + align:start position:0% +sort of you have to do nowadays as +profess so if somebody simply wanted to + + align:start position:0% +profess so if somebody simply wanted to + + + align:start position:0% +profess so if somebody simply wanted to +or mainly wanted to Professor to teach + + align:start position:0% +or mainly wanted to Professor to teach + + + align:start position:0% +or mainly wanted to Professor to teach +students or to help people then it might + + align:start position:0% +students or to help people then it might + + + align:start position:0% +students or to help people then it might +have been a better idea with those + + align:start position:0% +have been a better idea with those + + + align:start position:0% +have been a better idea with those +assumptions back then I missed the first + + align:start position:0% +assumptions back then I missed the first + + + align:start position:0% +assumptions back then I missed the first +point that maybe um now being a + + align:start position:0% +point that maybe um now being a + + + align:start position:0% +point that maybe um now being a +professor isn't as straightforward as as + + align:start position:0% +professor isn't as straightforward as as + + + align:start position:0% +professor isn't as straightforward as as +teaching and helping students and um + + align:start position:0% +teaching and helping students and um + + + align:start position:0% +teaching and helping students and um +sort of the more noble goals of why + + align:start position:0% +sort of the more noble goals of why + + + align:start position:0% +sort of the more noble goals of why +somebody might want to be Professor + + align:start position:0% +somebody might want to be Professor + + + align:start position:0% +somebody might want to be Professor +nowadays it's it's also a lot more um + + align:start position:0% +nowadays it's it's also a lot more um + + + align:start position:0% +nowadays it's it's also a lot more um +dealing with politics and dealing with + + align:start position:0% +dealing with politics and dealing with + + + align:start position:0% +dealing with politics and dealing with +the struggle to get tened and to look + + align:start position:0% +the struggle to get tened and to look + + + align:start position:0% +the struggle to get tened and to look +good and these things that maybe are + + align:start position:0% +good and these things that maybe are + + + align:start position:0% +good and these things that maybe are +sort of secondary for people get in the + + align:start position:0% +sort of secondary for people get in the + + + align:start position:0% +sort of secondary for people get in the +way of what they actually want to + + align:start position:0% +way of what they actually want to + + + align:start position:0% +way of what they actually want to +do oh yeah that that might be + + align:start position:0% +do oh yeah that that might be + + + align:start position:0% +do oh yeah that that might be +true because in the golden age uh things + + align:start position:0% +true because in the golden age uh things + + + align:start position:0% +true because in the golden age uh things +were expanding just that so if you did + + align:start position:0% +were expanding just that so if you did + + + align:start position:0% +were expanding just that so if you did +want to just if if your main goal was to + + align:start position:0% +want to just if if your main goal was to + + + align:start position:0% +want to just if if your main goal was to +teach people then you wouldn't it might + + align:start position:0% +teach people then you wouldn't it might + + + align:start position:0% +teach people then you wouldn't it might +nowadays maybe the best way to do that + + align:start position:0% +nowadays maybe the best way to do that + + + align:start position:0% +nowadays maybe the best way to do that +wouldn't necessarily be to be a + + align:start position:0% +wouldn't necessarily be to be a + + + align:start position:0% +wouldn't necessarily be to be a +professor you would get a job where you + + align:start position:0% +professor you would get a job where you + + + align:start position:0% +professor you would get a job where you +could get paid pretty well um to do + + align:start position:0% +could get paid pretty well um to do + + + align:start position:0% +could get paid pretty well um to do +something where you weren't a professor + + align:start position:0% +something where you weren't a professor + + + align:start position:0% +something where you weren't a professor +and then your spare time you could teach + + align:start position:0% +and then your spare time you could teach + + + align:start position:0% +and then your spare time you could teach +a lot of people and you could teach + + align:start position:0% +a lot of people and you could teach + + + align:start position:0% +a lot of people and you could teach +people that maybe needed to be taught + + align:start position:0% +people that maybe needed to be taught + + + align:start position:0% +people that maybe needed to be taught +rather than the ones to + + align:start position:0% +rather than the ones to + + + align:start position:0% +rather than the ones to +teach well it's going to be interesting + + align:start position:0% +teach well it's going to be interesting + + + align:start position:0% +teach well it's going to be interesting +to see what happens + + align:start position:0% +to see what happens + + + align:start position:0% +to see what happens +if what's the professor who has the uh + + align:start position:0% +if what's the professor who has the uh + + + align:start position:0% +if what's the professor who has the uh +huge + + align:start position:0% +huge + + + align:start position:0% +huge +web web thing + + align:start position:0% + + + + align:start position:0% + +going what + + align:start position:0% +going what + + + align:start position:0% +going what +else um is this guy at this California + + align:start position:0% +else um is this guy at this California + + + align:start position:0% +else um is this guy at this California +Professor who has got millions of people + + align:start position:0% +Professor who has got millions of people + + + align:start position:0% +Professor who has got millions of people +watching + + align:start position:0% +watching + + + align:start position:0% +watching +Sebastian Sebastian thr and + + align:start position:0% +Sebastian Sebastian thr and + + + align:start position:0% +Sebastian Sebastian thr and +Peter oh that but that's very small + + align:start position:0% +Peter oh that but that's very small + + + align:start position:0% +Peter oh that but that's very small +compared to the new one what's the guy + + align:start position:0% +compared to the new one what's the guy + + + align:start position:0% +compared to the new one what's the guy +named + + align:start position:0% + + + + align:start position:0% + +KH actually how big is the Google + + align:start position:0% +KH actually how big is the Google + + + align:start position:0% +KH actually how big is the Google +thing the thr thing it's the Stanford is + + align:start position:0% +thing the thr thing it's the Stanford is + + + align:start position:0% +thing the thr thing it's the Stanford is +that pretty big + + align:start position:0% +that pretty big + + + align:start position:0% +that pretty big +now it's several they're going to expand + + align:start position:0% +now it's several they're going to expand + + + align:start position:0% +now it's several they're going to expand +so that uh well what does that + + align:start position:0% + + + + align:start position:0% + +mean is that can they + + align:start position:0% +mean is that can they + + + align:start position:0% +mean is that can they +actually get better results than + + align:start position:0% +actually get better results than + + + align:start position:0% +actually get better results than +classroom teaching I don't see why + + align:start position:0% +classroom teaching I don't see why + + + align:start position:0% +classroom teaching I don't see why +not he's getting like better results in + + align:start position:0% +not he's getting like better results in + + + align:start position:0% +not he's getting like better results in +some + + align:start position:0% +some + + + align:start position:0% +some +districts who is uh K oh oh that's + + align:start position:0% +districts who is uh K oh oh that's + + + align:start position:0% +districts who is uh K oh oh that's +different yeah KH Academy actually was + + align:start position:0% +different yeah KH Academy actually was + + + align:start position:0% +different yeah KH Academy actually was +never a teacher professor and finance + + align:start position:0% +never a teacher professor and finance + + + align:start position:0% +never a teacher professor and finance +and started out with a one one video + + align:start position:0% +and started out with a one one video + + + align:start position:0% +and started out with a one one video +tutorial for his niece that he was + + align:start position:0% +tutorial for his niece that he was + + + align:start position:0% +tutorial for his niece that he was +tutoring and just put it up on YouTube + + align:start position:0% +tutoring and just put it up on YouTube + + + align:start position:0% +tutoring and just put it up on YouTube +for anybody got positive abuse and + + align:start position:0% +for anybody got positive abuse and + + + align:start position:0% +for anybody got positive abuse and +started you well there's a lot of + + align:start position:0% +started you well there's a lot of + + + align:start position:0% +started you well there's a lot of +interesting questions + + align:start position:0% +interesting questions + + + align:start position:0% +interesting questions +about whether + + align:start position:0% + + + + align:start position:0% + +it seems to me in my experience + + align:start position:0% +it seems to me in my experience + + + align:start position:0% +it seems to me in my experience +was interesting + + align:start position:0% +was interesting + + + align:start position:0% +was interesting +because if a + + align:start position:0% + + + + align:start position:0% + +professor said something that surprised + + align:start position:0% +professor said something that surprised + + + align:start position:0% +professor said something that surprised +me I would ask him how he thought or her + + align:start position:0% +me I would ask him how he thought or her + + + align:start position:0% +me I would ask him how he thought or her +there weren't many hers I have to + + align:start position:0% +there weren't many hers I have to + + + align:start position:0% +there weren't many hers I have to +admit I would ask the professor how did + + align:start position:0% +admit I would ask the professor how did + + + align:start position:0% +admit I would ask the professor how did +he think of + + align:start position:0% +he think of + + + align:start position:0% +he think of +that and so because I knew that I could + + align:start position:0% +that and so because I knew that I could + + + align:start position:0% +that and so because I knew that I could +look it up if it was you know if it's + + align:start position:0% +look it up if it was you know if it's + + + align:start position:0% +look it up if it was you know if it's +something some proof of a theorem then + + align:start position:0% +something some proof of a theorem then + + + align:start position:0% +something some proof of a theorem then +it's probably published and very likely + + align:start position:0% +it's probably published and very likely + + + align:start position:0% +it's probably published and very likely +gauss's proof is better than the current + + align:start position:0% +gauss's proof is better than the current + + + align:start position:0% +gauss's proof is better than the current +one + + align:start position:0% +one + + + align:start position:0% +one +anyway that's a joke I think but uh + + align:start position:0% + + + + align:start position:0% + +I don't see how you could get that out + + align:start position:0% +I don't see how you could get that out + + + align:start position:0% +I don't see how you could get that out +of a uh non-interactive + + align:start position:0% +of a uh non-interactive + + + align:start position:0% +of a uh non-interactive +system you can't go and ask Andrew + + align:start position:0% +system you can't go and ask Andrew + + + align:start position:0% +system you can't go and ask Andrew +gleon uh how did you get that idea then + + align:start position:0% +gleon uh how did you get that idea then + + + align:start position:0% +gleon uh how did you get that idea then +he would struggle + + align:start position:0% + + + + align:start position:0% + +and um maybe tell me how he got that + + align:start position:0% +and um maybe tell me how he got that + + + align:start position:0% +and um maybe tell me how he got that +idea which + + align:start position:0% + + + + align:start position:0% + +was but perhaps a great teacher can + + align:start position:0% +was but perhaps a great teacher can + + + align:start position:0% +was but perhaps a great teacher can +evolve lectures in which + + align:start position:0% +evolve lectures in which + + + align:start position:0% +evolve lectures in which +you not only explain + + align:start position:0% +you not only explain + + + align:start position:0% +you not only explain +what the student has to know on a test + + align:start position:0% +what the student has to know on a test + + + align:start position:0% +what the student has to know on a test +but you can teach ways to think about + + align:start position:0% +but you can teach ways to think about + + + align:start position:0% +but you can teach ways to think about +it I don't know + + align:start position:0% +it I don't know + + + align:start position:0% +it I don't know +how how much like netive expertise you + + align:start position:0% +how how much like netive expertise you + + + align:start position:0% +how how much like netive expertise you +can convey through non interactive + + align:start position:0% +can convey through non interactive + + + align:start position:0% +can convey through non interactive +lecture exactly that's a + + align:start position:0% +lecture exactly that's a + + + align:start position:0% +lecture exactly that's a +question and maybe you can do a + + align:start position:0% +question and maybe you can do a + + + align:start position:0% +question and maybe you can do a +tremendous amount of it as the thing + + align:start position:0% +tremendous amount of it as the thing + + + align:start position:0% +tremendous amount of it as the thing +evolves because + + align:start position:0% +evolves because + + + align:start position:0% +evolves because +right now there's nothing the student + + align:start position:0% +right now there's nothing the student + + + align:start position:0% +right now there's nothing the student +can type when they're watching the + + align:start position:0% +can type when they're watching the + + + align:start position:0% +can type when they're watching the +lecture I presume + + align:start position:0% +lecture I presume + + + align:start position:0% +lecture I presume +nobody's or is there an army of of + + align:start position:0% +nobody's or is there an army of of + + + align:start position:0% +nobody's or is there an army of of +graduate + + align:start position:0% +graduate + + + align:start position:0% +graduate +students uh at terminals answering + + align:start position:0% +students uh at terminals answering + + + align:start position:0% +students uh at terminals answering +questions to go with with with these + + align:start position:0% +questions to go with with with these + + + align:start position:0% +questions to go with with with these +lectures what these online courses yeah + + align:start position:0% +lectures what these online courses yeah + + + align:start position:0% +lectures what these online courses yeah +well what they're learning from The New + + align:start position:0% +well what they're learning from The New + + + align:start position:0% +well what they're learning from The New +York Times is writing up both KH and + + align:start position:0% +York Times is writing up both KH and + + + align:start position:0% +York Times is writing up both KH and +Stanford as models and they Stanford + + align:start position:0% +Stanford as models and they Stanford + + + align:start position:0% +Stanford as models and they Stanford +uh took from Comm that you have 10 + + align:start position:0% +uh took from Comm that you have 10 + + + align:start position:0% +uh took from Comm that you have 10 +minute no more than five or 10 minute + + align:start position:0% +minute no more than five or 10 minute + + + align:start position:0% +minute no more than five or 10 minute +like + + align:start position:0% +like + + + align:start position:0% +like +uh presentations and then you have some + + align:start position:0% +uh presentations and then you have some + + + align:start position:0% +uh presentations and then you have some +activity yeah where did that hour come + + align:start position:0% +activity yeah where did that hour come + + + align:start position:0% +activity yeah where did that hour come +from + + align:start position:0% + + + + align:start position:0% + +yeah so in that but after the 10 minutes + + align:start position:0% +yeah so in that but after the 10 minutes + + + align:start position:0% +yeah so in that but after the 10 minutes +is there an army of people you can + + align:start position:0% +is there an army of people you can + + + align:start position:0% +is there an army of people you can +interact with well you interact with the + + align:start position:0% +interact with well you interact with the + + + align:start position:0% +interact with well you interact with the +problem and then and then you get + + align:start position:0% +problem and then and then you get + + + align:start position:0% +problem and then and then you get +another 10minute thing uhhuh now some + + align:start position:0% +another 10minute thing uhhuh now some + + + align:start position:0% +another 10minute thing uhhuh now some +places are organizing so they have + + align:start position:0% +places are organizing so they have + + + align:start position:0% +places are organizing so they have +um uh like they expect parents a parent + + align:start position:0% +um uh like they expect parents a parent + + + align:start position:0% +um uh like they expect parents a parent +for example to be with a high school + + align:start position:0% +for example to be with a high school + + + align:start position:0% +for example to be with a high school +student or Elementary School + + align:start position:0% +student or Elementary School + + + align:start position:0% +student or Elementary School +student and while they're interacting + + align:start position:0% +student and while they're interacting + + + align:start position:0% +student and while they're interacting +with this um computer + + align:start position:0% +with this um computer + + + align:start position:0% +with this um computer +stuff + + align:start position:0% +stuff + + + align:start position:0% +stuff +yes at least in the + + align:start position:0% +yes at least in the + + + align:start position:0% +yes at least in the +um that he he people can ask questions + + align:start position:0% +um that he he people can ask questions + + + align:start position:0% +um that he he people can ask questions +underneath each video and if you look + + align:start position:0% +underneath each video and if you look + + + align:start position:0% +underneath each video and if you look +under a video sometimes you can see a + + align:start position:0% +under a video sometimes you can see a + + + align:start position:0% +under a video sometimes you can see a +fair amount of of decent questions um so + + align:start position:0% +fair amount of of decent questions um so + + + align:start position:0% +fair amount of of decent questions um so +in this case you might not only have + + align:start position:0% +in this case you might not only have + + + align:start position:0% +in this case you might not only have +your question answered but you might get + + align:start position:0% +your question answered but you might get + + + align:start position:0% +your question answered but you might get +other questions that you think to ask + + align:start position:0% +other questions that you think to ask + + + align:start position:0% +other questions that you think to ask +and it's always there to look + + align:start position:0% +and it's always there to look + + + align:start position:0% +and it's always there to look +reference well in fact interacting with + + align:start position:0% +reference well in fact interacting with + + + align:start position:0% +reference well in fact interacting with +a + + align:start position:0% +a + + + align:start position:0% +a +person could be that the person if you + + align:start position:0% +person could be that the person if you + + + align:start position:0% +person could be that the person if you +didn't seem to understand something the + + align:start position:0% +didn't seem to understand something the + + + align:start position:0% +didn't seem to understand something the +person gives you similar problems that + + align:start position:0% +person gives you similar problems that + + + align:start position:0% +person gives you similar problems that +are + + align:start position:0% +are + + + align:start position:0% +are +just slightly different point of view or + + align:start position:0% +just slightly different point of view or + + + align:start position:0% +just slightly different point of view or +slightly easier + + align:start position:0% +slightly easier + + + align:start position:0% +slightly easier +or U or analogies with something that + + align:start position:0% +or U or analogies with something that + + + align:start position:0% +or U or analogies with something that +they know you know and yeah + + align:start position:0% +they know you know and yeah + + + align:start position:0% +they know you know and yeah +so uh presumbly in the long run you can + + align:start position:0% +so uh presumbly in the long run you can + + + align:start position:0% +so uh presumbly in the long run you can +make these interactive systems have + + align:start position:0% +make these interactive systems have + + + align:start position:0% +make these interactive systems have +large bodies of pedagogical + + align:start position:0% +large bodies of pedagogical + + + align:start position:0% +large bodies of pedagogical +knowledge for for each kind of problem + + align:start position:0% +knowledge for for each kind of problem + + + align:start position:0% +knowledge for for each kind of problem +you could have a huge tree of one of the + + align:start position:0% +you could have a huge tree of one of the + + + align:start position:0% +you could have a huge tree of one of the +most common misunderstandings in what's + + align:start position:0% +most common misunderstandings in what's + + + align:start position:0% +most common misunderstandings in what's +the best hint for getting out of this + + align:start position:0% +the best hint for getting out of this + + + align:start position:0% +the best hint for getting out of this +dead end or that dead end so maybe + + align:start position:0% +dead end or that dead end so maybe + + + align:start position:0% +dead end or that dead end so maybe +something will evolve + + align:start position:0% +something will evolve + + + align:start position:0% +something will evolve +but it means there either have to be + + align:start position:0% +but it means there either have to be + + + align:start position:0% +but it means there either have to be +assistants who can do it which is + + align:start position:0% +assistants who can do it which is + + + align:start position:0% +assistants who can do it which is +unlikely or natural language + + align:start position:0% +unlikely or natural language + + + align:start position:0% +unlikely or natural language +understanders that that can so you can + + align:start position:0% +understanders that that can so you can + + + align:start position:0% +understanders that that can so you can +reply to this or ask it questions and it + + align:start position:0% +reply to this or ask it questions and it + + + align:start position:0% +reply to this or ask it questions and it +can go find a better lecture for if + + align:start position:0% +can go find a better lecture for if + + + align:start position:0% +can go find a better lecture for if +you're having that particular trouble + + align:start position:0% + + + + align:start position:0% + +think traditional + + align:start position:0% +think traditional + + + align:start position:0% +think traditional +classroom they're lacking things like + + align:start position:0% +classroom they're lacking things like + + + align:start position:0% +classroom they're lacking things like +that as well like I don't think the + + align:start position:0% +that as well like I don't think the + + + align:start position:0% +that as well like I don't think the +traditional classroom has done too well + + align:start position:0% +traditional classroom has done too well + + + align:start position:0% +traditional classroom has done too well +well normally if you have 30 students in + + align:start position:0% +well normally if you have 30 students in + + + align:start position:0% +well normally if you have 30 students in +the + + align:start position:0% +the + + + align:start position:0% +the +classroom uh the teacher is paying + + align:start position:0% +classroom uh the teacher is paying + + + align:start position:0% +classroom uh the teacher is paying +attention to four or five of + + align:start position:0% +attention to four or five of + + + align:start position:0% +attention to four or five of +them because Mo most people don't + + align:start position:0% +them because Mo most people don't + + + align:start position:0% +them because Mo most people don't +interact and every class if you're lucky + + align:start position:0% +interact and every class if you're lucky + + + align:start position:0% +interact and every class if you're lucky +you have several students who + + align:start position:0% + + + + align:start position:0% + +interact I kind of feel like with um I + + align:start position:0% +interact I kind of feel like with um I + + + align:start position:0% +interact I kind of feel like with um I +kind of feel like since there's so much + + align:start position:0% +kind of feel like since there's so much + + + align:start position:0% +kind of feel like since there's so much +like just so much that Al works just by + + align:start position:0% +like just so much that Al works just by + + + align:start position:0% +like just so much that Al works just by +making these like lectures like like a + + align:start position:0% +making these like lectures like like a + + + align:start position:0% +making these like lectures like like a +social tool with all like the YouTube + + align:start position:0% +social tool with all like the YouTube + + + align:start position:0% +social tool with all like the YouTube +videos with like uh you know like it's + + align:start position:0% +videos with like uh you know like it's + + + align:start position:0% +videos with like uh you know like it's +basically like a frequently asked + + align:start position:0% +basically like a frequently asked + + + align:start position:0% +basically like a frequently asked +questions list like you know in the coms + + align:start position:0% +questions list like you know in the coms + + + align:start position:0% +questions list like you know in the coms +so I feel like before I feel like since + + align:start position:0% +so I feel like before I feel like since + + + align:start position:0% +so I feel like before I feel like since +there's + + align:start position:0% +there's + + + align:start position:0% +there's +already um like an + + align:start position:0% +already um like an + + + align:start position:0% +already um like an +easier easier than AI like solution to + + align:start position:0% +easier easier than AI like solution to + + + align:start position:0% +easier easier than AI like solution to +like help with that there's never going + + align:start position:0% +like help with that there's never going + + + align:start position:0% +like help with that there's never going +to be like a like an impetus to actually + + align:start position:0% +to be like a like an impetus to actually + + + align:start position:0% +to be like a like an impetus to actually +go and build like a like build like a + + align:start position:0% +go and build like a like build like a + + + align:start position:0% +go and build like a like build like a +system that will definitely answer your + + align:start position:0% +system that will definitely answer your + + + align:start position:0% +system that will definitely answer your +questions like you know answer your + + align:start position:0% +questions like you know answer your + + + align:start position:0% +questions like you know answer your +questions about the lecture like + + align:start position:0% +questions about the lecture like + + + align:start position:0% +questions about the lecture like +correctly or give you more practice ones + + align:start position:0% +correctly or give you more practice ones + + + align:start position:0% +correctly or give you more practice ones +it be like such like a harder + + align:start position:0% +it be like such like a harder + + + align:start position:0% +it be like such like a harder +infrastructure to set up and I think I + + align:start position:0% +infrastructure to set up and I think I + + + align:start position:0% +infrastructure to set up and I think I +think before that happens there's just + + align:start position:0% +think before that happens there's just + + + align:start position:0% +think before that happens there's just +going to be more tools to make anything + + align:start position:0% +going to be more tools to make anything + + + align:start position:0% +going to be more tools to make anything +easily like social socially sharable + + align:start position:0% +easily like social socially sharable + + + align:start position:0% +easily like social socially sharable +like it um and like I think I think + + align:start position:0% +like it um and like I think I think + + + align:start position:0% +like it um and like I think I think +people are going to like gravitate more + + align:start position:0% +people are going to like gravitate more + + + align:start position:0% +people are going to like gravitate more +towards making things + + align:start position:0% +towards making things + + + align:start position:0% +towards making things +um yeah making things easier in a social + + align:start position:0% +um yeah making things easier in a social + + + align:start position:0% +um yeah making things easier in a social +way that already seems to be um well + + align:start position:0% +way that already seems to be um well + + + align:start position:0% +way that already seems to be um well +that's raising an AI question + + align:start position:0% +that's raising an AI question + + + align:start position:0% +that's raising an AI question +because you can imagine some years out + + align:start position:0% +because you can imagine some years out + + + align:start position:0% +because you can imagine some years out +that this system evolves + + align:start position:0% +that this system evolves + + + align:start position:0% +that this system evolves +and and + + align:start position:0% +and and + + + align:start position:0% +and and +um the Stanford thing gets to the point + + align:start position:0% +um the Stanford thing gets to the point + + + align:start position:0% +um the Stanford thing gets to the point +where uh you can ask a question and uh + + align:start position:0% +where uh you can ask a question and uh + + + align:start position:0% +where uh you can ask a question and uh +you know like Siri or this Dragon thing + + align:start position:0% +you know like Siri or this Dragon thing + + + align:start position:0% +you know like Siri or this Dragon thing +here and you ask it a question and + + align:start position:0% +here and you ask it a question and + + + align:start position:0% +here and you ask it a question and +understands it and it Roots itself to + + align:start position:0% +understands it and it Roots itself to + + + align:start position:0% +understands it and it Roots itself to +another EX example of the same thing and + + align:start position:0% +another EX example of the same thing and + + + align:start position:0% +another EX example of the same thing and +gradually a huge database appears that + + align:start position:0% +gradually a huge database appears that + + + align:start position:0% +gradually a huge database appears that +uh teaches you a lot of abstract algebra + + align:start position:0% +uh teaches you a lot of abstract algebra + + + align:start position:0% +uh teaches you a lot of abstract algebra +and has thousands of examples and pulls + + align:start position:0% +and has thousands of examples and pulls + + + align:start position:0% +and has thousands of examples and pulls +out just the right one for the confusion + + align:start position:0% +out just the right one for the confusion + + + align:start position:0% +out just the right one for the confusion +it diagnoses you to have so I + + align:start position:0% +it diagnoses you to have so I + + + align:start position:0% +it diagnoses you to have so I +think in other words maybe the AIS will + + align:start position:0% +think in other words maybe the AIS will + + + align:start position:0% +think in other words maybe the AIS will +emerge from making interactive uh + + align:start position:0% +emerge from making interactive uh + + + align:start position:0% +emerge from making interactive uh +teaching programs rather than than these + + align:start position:0% +teaching programs rather than than these + + + align:start position:0% +teaching programs rather than than these +sort of artificial projects where you're + + align:start position:0% +sort of artificial projects where you're + + + align:start position:0% +sort of artificial projects where you're +trying to make a a program that actually + + align:start position:0% +trying to make a a program that actually + + + align:start position:0% +trying to make a a program that actually +solves some hard + + align:start position:0% +solves some hard + + + align:start position:0% +solves some hard +problem but making a program that has + + align:start position:0% +problem but making a program that has + + + align:start position:0% +problem but making a program that has +thousands of ways to solve a problem and + + align:start position:0% +thousands of ways to solve a problem and + + + align:start position:0% +thousands of ways to solve a problem and +it and it didn't invent them uh might be + + align:start position:0% +it and it didn't invent them uh might be + + + align:start position:0% +it and it didn't invent them uh might be +even + + align:start position:0% +even + + + align:start position:0% +even +better so I think um one issue here okay + + align:start position:0% +better so I think um one issue here okay + + + align:start position:0% +better so I think um one issue here okay +there are two issues at hand one issue + + align:start position:0% +there are two issues at hand one issue + + + align:start position:0% +there are two issues at hand one issue +is after all your a calculus teacher + + align:start position:0% +is after all your a calculus teacher + + + align:start position:0% +is after all your a calculus teacher +didn't invent calculus + + align:start position:0% +didn't invent calculus + + + align:start position:0% +didn't invent calculus +that was that was + + align:start position:0% +that was that was + + + align:start position:0% +that was that was +Newton so in speaking about Con Academy + + align:start position:0% +Newton so in speaking about Con Academy + + + align:start position:0% +Newton so in speaking about Con Academy +I think it's important to separate um a + + align:start position:0% +I think it's important to separate um a + + + align:start position:0% +I think it's important to separate um a +couple of different issues so the first + + align:start position:0% +couple of different issues so the first + + + align:start position:0% +couple of different issues so the first +issue is like whether Con Academy is a + + align:start position:0% +issue is like whether Con Academy is a + + + align:start position:0% +issue is like whether Con Academy is a +good tool and I think in this case it's + + align:start position:0% +good tool and I think in this case it's + + + align:start position:0% +good tool and I think in this case it's +clear that like it solves the problems + + align:start position:0% +clear that like it solves the problems + + + align:start position:0% +clear that like it solves the problems +that it it it does it's how do I say + + align:start position:0% +that it it it does it's how do I say + + + align:start position:0% +that it it it does it's how do I say +this it's good at what it claims to do + + align:start position:0% +this it's good at what it claims to do + + + align:start position:0% +this it's good at what it claims to do +so it some advantages that it has is + + align:start position:0% +so it some advantages that it has is + + + align:start position:0% +so it some advantages that it has is +that well it allows it explains the + + align:start position:0% +that well it allows it explains the + + + align:start position:0% +that well it allows it explains the +concepts clearly um and the video format + + align:start position:0% +concepts clearly um and the video format + + + align:start position:0% +concepts clearly um and the video format +allows you to like go back and sort of + + align:start position:0% +allows you to like go back and sort of + + + align:start position:0% +allows you to like go back and sort of +listen listen to things again if you + + align:start position:0% +listen listen to things again if you + + + align:start position:0% +listen listen to things again if you +don't understand the first time which + + align:start position:0% +don't understand the first time which + + + align:start position:0% +don't understand the first time which +you don't quite get in a lecture hall um + + align:start position:0% +you don't quite get in a lecture hall um + + + align:start position:0% +you don't quite get in a lecture hall um +and the third Advantage as L pointed out + + align:start position:0% +and the third Advantage as L pointed out + + + align:start position:0% +and the third Advantage as L pointed out +is like it sort of acts as a Social Hub + + align:start position:0% +is like it sort of acts as a Social Hub + + + align:start position:0% +is like it sort of acts as a Social Hub +um where different people can like look + + align:start position:0% +um where different people can like look + + + align:start position:0% +um where different people can like look +at each other's questions now just + + align:start position:0% +at each other's questions now just + + + align:start position:0% +at each other's questions now just +because KH Academy is good at the things + + align:start position:0% +because KH Academy is good at the things + + + align:start position:0% +because KH Academy is good at the things +that it claims to do and maybe some + + align:start position:0% +that it claims to do and maybe some + + + align:start position:0% +that it claims to do and maybe some +other things too doesn't mean that like + + align:start position:0% +other things too doesn't mean that like + + + align:start position:0% +other things too doesn't mean that like +it doesn't mean that there aren't other + + align:start position:0% +it doesn't mean that there aren't other + + + align:start position:0% +it doesn't mean that there aren't other +tools that like can do more than what KH + + align:start position:0% +tools that like can do more than what KH + + + align:start position:0% +tools that like can do more than what KH +Academy does um and can sort of like + + align:start position:0% +Academy does um and can sort of like + + + align:start position:0% +Academy does um and can sort of like +expand the way that we interact with + + align:start position:0% +expand the way that we interact with + + + align:start position:0% +expand the way that we interact with +these learning tools so I think it's + + align:start position:0% +these learning tools so I think it's + + + align:start position:0% +these learning tools so I think it's +it's like it's sort of fruitless to say + + align:start position:0% +it's like it's sort of fruitless to say + + + align:start position:0% +it's like it's sort of fruitless to say +oh well KH Academy is already really + + align:start position:0% +oh well KH Academy is already really + + + align:start position:0% +oh well KH Academy is already really +good at teaching that's all we need um + + align:start position:0% +good at teaching that's all we need um + + + align:start position:0% +good at teaching that's all we need um +because I think as you you said like + + align:start position:0% +because I think as you you said like + + + align:start position:0% +because I think as you you said like +there are other tools that are + + align:start position:0% +there are other tools that are + + + align:start position:0% +there are other tools that are +completely like way bigger than the + + align:start position:0% +completely like way bigger than the + + + align:start position:0% +completely like way bigger than the +scope of what KH Academy does that can + + align:start position:0% +scope of what KH Academy does that can + + + align:start position:0% +scope of what KH Academy does that can +be really good for education so for + + align:start position:0% +be really good for education so for + + + align:start position:0% +be really good for education so for +instance some things that this thing + + align:start position:0% +instance some things that this thing + + + align:start position:0% +instance some things that this thing +does not address are like okay okay so + + align:start position:0% +does not address are like okay okay so + + + align:start position:0% +does not address are like okay okay so +how does the the issue of like + + align:start position:0% +how does the the issue of like + + + align:start position:0% +how does the the issue of like +interaction between like the professor + + align:start position:0% +interaction between like the professor + + + align:start position:0% +interaction between like the professor +and the students come into play with + + align:start position:0% +and the students come into play with + + + align:start position:0% +and the students come into play with +learning or like what if you can ask + + align:start position:0% +learning or like what if you can ask + + + align:start position:0% +learning or like what if you can ask +questions that you can cover um and + + align:start position:0% +questions that you can cover um and + + + align:start position:0% +questions that you can cover um and +it'll give you a + + align:start position:0% +it'll give you a + + + align:start position:0% +it'll give you a +response so I guess it's the idea of + + align:start position:0% +response so I guess it's the idea of + + + align:start position:0% +response so I guess it's the idea of +like Okay so this tool is good for these + + align:start position:0% +like Okay so this tool is good for these + + + align:start position:0% +like Okay so this tool is good for these +sets of things but then there are + + align:start position:0% +sets of things but then there are + + + align:start position:0% +sets of things but then there are +other other features that we might want + + align:start position:0% +other other features that we might want + + + align:start position:0% +other other features that we might want +in a learning tool that it currently + + align:start position:0% +in a learning tool that it currently + + + align:start position:0% +in a learning tool that it currently +doesn't have and it doesn't even try to + + align:start position:0% +doesn't have and it doesn't even try to + + + align:start position:0% +doesn't have and it doesn't even try to +have + + align:start position:0% + + + + align:start position:0% + +see another thing is that a lot of times + + align:start position:0% +see another thing is that a lot of times + + + align:start position:0% +see another thing is that a lot of times +we'll ask questions to the students + + align:start position:0% +we'll ask questions to the students + + + align:start position:0% +we'll ask questions to the students +means I don't know I've seen Learning + + align:start position:0% +means I don't know I've seen Learning + + + align:start position:0% +means I don't know I've seen Learning +Systems where I think the Stanford one + + align:start position:0% +Systems where I think the Stanford one + + + align:start position:0% +Systems where I think the Stanford one +does this is based on how you answer the + + align:start position:0% +does this is based on how you answer the + + + align:start position:0% +does this is based on how you answer the +questions it will then gear new + + align:start position:0% +questions it will then gear new + + + align:start position:0% +questions it will then gear new +questions forward wherever your weakest + + align:start position:0% +questions forward wherever your weakest + + + align:start position:0% +questions forward wherever your weakest +um but if you think about a system that + + align:start position:0% +um but if you think about a system that + + + align:start position:0% +um but if you think about a system that +might have 40,000 students and it can + + align:start position:0% +might have 40,000 students and it can + + + align:start position:0% +might have 40,000 students and it can +learn which questions help weak students + + align:start position:0% +learn which questions help weak students + + + align:start position:0% +learn which questions help weak students +in certain areas converge towards + + align:start position:0% +in certain areas converge towards + + + align:start position:0% +in certain areas converge towards +becoming stronger fastest then it's like + + align:start position:0% +becoming stronger fastest then it's like + + + align:start position:0% +becoming stronger fastest then it's like +a teacher who's taught 40,000 students + + align:start position:0% +a teacher who's taught 40,000 students + + + align:start position:0% +a teacher who's taught 40,000 students +but you know which takes you know very + + align:start position:0% +but you know which takes you know very + + + align:start position:0% +but you know which takes you know very +few teachers that have that sort of + + align:start position:0% +few teachers that have that sort of + + + align:start position:0% +few teachers that have that sort of +experience or of knowledge at some ex + + align:start position:0% +experience or of knowledge at some ex + + + align:start position:0% +experience or of knowledge at some ex +there are some scale that you can get + + align:start position:0% +there are some scale that you can get + + + align:start position:0% +there are some scale that you can get +only in a computer system that are hard + + align:start position:0% +only in a computer system that are hard + + + align:start position:0% +only in a computer system that are hard +to replicate in a real + + align:start position:0% +to replicate in a real + + + align:start position:0% +to replicate in a real +world the system has to get to some + + align:start position:0% +world the system has to get to some + + + align:start position:0% +world the system has to get to some +level of understanding that that we're + + align:start position:0% +level of understanding that that we're + + + align:start position:0% +level of understanding that that we're +nowhere near yet but but with things + + align:start position:0% +nowhere near yet but but with things + + + align:start position:0% +nowhere near yet but but with things +like Siri apparently you can uh Bluff + + align:start position:0% +like Siri apparently you can uh Bluff + + + align:start position:0% +like Siri apparently you can uh Bluff +your way through very well + + align:start position:0% +your way through very well + + + align:start position:0% +your way through very well +and uh maybe well enough that then you + + align:start position:0% +and uh maybe well enough that then you + + + align:start position:0% +and uh maybe well enough that then you +can find a for or five answers to the + + align:start position:0% +can find a for or five answers to the + + + align:start position:0% +can find a for or five answers to the +student's question and the student can + + align:start position:0% +student's question and the student can + + + align:start position:0% +student's question and the student can +quickly see that uh the this particular + + align:start position:0% +quickly see that uh the this particular + + + align:start position:0% +quickly see that uh the this particular +one is the student has to be encouraged + + align:start position:0% +one is the student has to be encouraged + + + align:start position:0% +one is the student has to be encouraged +to be skeptical of the machine so you + + align:start position:0% +to be skeptical of the machine so you + + + align:start position:0% +to be skeptical of the machine so you +ask it a question and he get gives you + + align:start position:0% +ask it a question and he get gives you + + + align:start position:0% +ask it a question and he get gives you +these different answers and you say well + + align:start position:0% +these different answers and you say well + + + align:start position:0% +these different answers and you say well +it didn't understand me for this and + + align:start position:0% +it didn't understand me for this and + + + align:start position:0% +it didn't understand me for this and +that okay + + align:start position:0% +that okay + + + align:start position:0% +that okay +instead of getting upset and trying to + + align:start position:0% +instead of getting upset and trying to + + + align:start position:0% +instead of getting upset and trying to +uh trying to convince yourself that it + + align:start position:0% +uh trying to convince yourself that it + + + align:start position:0% +uh trying to convince yourself that it +understood you uh just say oh it's just + + align:start position:0% +understood you uh just say oh it's just + + + align:start position:0% +understood you uh just say oh it's just +a dumb machine but I bet one of these + + align:start position:0% +a dumb machine but I bet one of these + + + align:start position:0% +a dumb machine but I bet one of these +five replies is what I really need yeah + + align:start position:0% +five replies is what I really need yeah + + + align:start position:0% +five replies is what I really need yeah +I don't know if you ever heard about qu + + align:start position:0% +I don't know if you ever heard about qu + + + align:start position:0% +I don't know if you ever heard about qu +it's it's all spell it k + + align:start position:0% +it's it's all spell it k + + + align:start position:0% +it's it's all spell it k +q q u o r a no I don't I haven't heard + + align:start position:0% +q q u o r a no I don't I haven't heard + + + align:start position:0% +q q u o r a no I don't I haven't heard +so uh basically they have uh it's a + + align:start position:0% +so uh basically they have uh it's a + + + align:start position:0% +so uh basically they have uh it's a +website where you ask random questions + + align:start position:0% +website where you ask random questions + + + align:start position:0% +website where you ask random questions +not R but they are very specialized + + align:start position:0% +not R but they are very specialized + + + align:start position:0% +not R but they are very specialized +questions and like it's divided I don't + + align:start position:0% +questions and like it's divided I don't + + + align:start position:0% +questions and like it's divided I don't +know maybe there's AI + + align:start position:0% +know maybe there's AI + + + align:start position:0% +know maybe there's AI +neuroscience and it's very good because + + align:start position:0% +neuroscience and it's very good because + + + align:start position:0% +neuroscience and it's very good because +there are a lot of smart people there + + align:start position:0% +there are a lot of smart people there + + + align:start position:0% +there are a lot of smart people there +that like the community there oh it's a + + align:start position:0% +that like the community there oh it's a + + + align:start position:0% +that like the community there oh it's a +social network uh yeah kind of a social + + align:start position:0% +social network uh yeah kind of a social + + + align:start position:0% +social network uh yeah kind of a social +network and I don't know like for + + align:start position:0% +network and I don't know like for + + + align:start position:0% +network and I don't know like for +example for this class there are some + + align:start position:0% +example for this class there are some + + + align:start position:0% +example for this class there are some +questions that I have in my mind and + + align:start position:0% +questions that I have in my mind and + + + align:start position:0% +questions that I have in my mind and +sometimes I can just post and smart + + align:start position:0% +sometimes I can just post and smart + + + align:start position:0% +sometimes I can just post and smart +really smart people who answer like + + align:start position:0% +really smart people who answer like + + + align:start position:0% +really smart people who answer like +there are lot of alumni from MIT and a + + align:start position:0% +there are lot of alumni from MIT and a + + + align:start position:0% +there are lot of alumni from MIT and a +lot of people from I don't know San + + align:start position:0% +lot of people from I don't know San + + + align:start position:0% +lot of people from I don't know San +Francisco from the Bay Area and also uh + + align:start position:0% +Francisco from the Bay Area and also uh + + + align:start position:0% +Francisco from the Bay Area and also uh +there's another resource I don't know if + + align:start position:0% +there's another resource I don't know if + + + align:start position:0% +there's another resource I don't know if +you ever heard about it + + align:start position:0% +you ever heard about it + + + align:start position:0% +you ever heard about it +Edge uh where like thinkers they can p + + align:start position:0% +Edge uh where like thinkers they can p + + + align:start position:0% +Edge uh where like thinkers they can p +what they they are thinking like smart + + align:start position:0% +what they they are thinking like smart + + + align:start position:0% +what they they are thinking like smart +people + + align:start position:0% +people + + + align:start position:0% +people +as Brooks your + + align:start position:0% +as Brooks your + + + align:start position:0% +as Brooks your +friend Rockman yes right is Edge + + align:start position:0% +friend Rockman yes right is Edge + + + align:start position:0% +friend Rockman yes right is Edge +yeah he has a quite a good collection of + + align:start position:0% +yeah he has a quite a good collection of + + + align:start position:0% +yeah he has a quite a good collection of +smart + + align:start position:0% + + + + align:start position:0% + +people and this may be be good for like + + align:start position:0% +people and this may be be good for like + + + align:start position:0% +people and this may be be good for like +questions that are more research + + align:start position:0% +questions that are more research + + + align:start position:0% +questions that are more research +oriented like or that ser can't so right + + align:start position:0% +oriented like or that ser can't so right + + + align:start position:0% +oriented like or that ser can't so right +now + + align:start position:0% + + + + align:start position:0% + +mhm I've been using this Dragon thing + + align:start position:0% +mhm I've been using this Dragon thing + + + align:start position:0% +mhm I've been using this Dragon thing +cuz series won't run on my iPhone + + align:start position:0% +cuz series won't run on my iPhone + + + align:start position:0% +cuz series won't run on my iPhone +4 but dragon has + + align:start position:0% +4 but dragon has + + + align:start position:0% +4 but dragon has +a question answering thing + + align:start position:0% +a question answering thing + + + align:start position:0% +a question answering thing +and it's unbelievably good the same comp + + align:start position:0% +and it's unbelievably good the same comp + + + align:start position:0% +and it's unbelievably good the same comp +what it's the same company + + align:start position:0% +what it's the same company + + + align:start position:0% +what it's the same company +Nuance Nuance is running the Siri thing + + align:start position:0% +Nuance Nuance is running the Siri thing + + + align:start position:0% +Nuance Nuance is running the Siri thing +owns both dragon and Siri + + align:start position:0% +owns both dragon and Siri + + + align:start position:0% +owns both dragon and Siri +oh oh okay so maybe it's it's the same + + align:start position:0% +oh oh okay so maybe it's it's the same + + + align:start position:0% +oh oh okay so maybe it's it's the same +speech engine they stole from + + align:start position:0% + + + + align:start position:0% + +Dragon it's remarkably good or else I've + + align:start position:0% +Dragon it's remarkably good or else I've + + + align:start position:0% +Dragon it's remarkably good or else I've +got the hang of asking the right + + align:start position:0% +got the hang of asking the right + + + align:start position:0% +got the hang of asking the right +question + + align:start position:0% + + + + align:start position:0% + +well how about one more + + align:start position:0% + + + + align:start position:0% + +disaster what about wire + + align:start position:0% +disaster what about wire + + + align:start position:0% +disaster what about wire +heading oh if uh it becomes cheap and + + align:start position:0% +heading oh if uh it becomes cheap and + + + align:start position:0% +heading oh if uh it becomes cheap and +convenient for everyone to have their + + align:start position:0% +convenient for everyone to have their + + + align:start position:0% +convenient for everyone to have their +own personal Paradise that could the + + align:start position:0% +own personal Paradise that could the + + + align:start position:0% +own personal Paradise that could the +device personal what Paradise + + align:start position:0% +device personal what Paradise + + + align:start position:0% +device personal what Paradise +yeah well is just turning this pleasure + + align:start position:0% +yeah well is just turning this pleasure + + + align:start position:0% +yeah well is just turning this pleasure +Center on without any any that's why the + + align:start position:0% +Center on without any any that's why the + + + align:start position:0% +Center on without any any that's why the +opposite of the + + align:start position:0% +opposite of the + + + align:start position:0% +opposite of the +singularity everyone's just on their own + + align:start position:0% +singularity everyone's just on their own + + + align:start position:0% +singularity everyone's just on their own +completely + + align:start position:0% +completely + + + align:start position:0% +completely +disconnected + + align:start position:0% + + + + align:start position:0% + +happy well there are + + align:start position:0% + + + + align:start position:0% + +some people get addicted to narcotics in + + align:start position:0% +some people get addicted to narcotics in + + + align:start position:0% +some people get addicted to narcotics in +one + + align:start position:0% +one + + + align:start position:0% +one +dose and lots of people in five or + + align:start position:0% +dose and lots of people in five or + + + align:start position:0% +dose and lots of people in five or +10 but uh you could imagine a narcotic + + align:start position:0% +10 but uh you could imagine a narcotic + + + align:start position:0% +10 but uh you could imagine a narcotic +that that addicts you in one dose + + align:start position:0% +that that addicts you in one dose + + + align:start position:0% +that that addicts you in one dose +reliably + + align:start position:0% +reliably + + + align:start position:0% +reliably +that that could be pretty dangerous but + + align:start position:0% + + + + align:start position:0% + +you have to learn to hate + + align:start position:0% + + + + align:start position:0% + +pleasure yes how do you get people to + + align:start position:0% +pleasure yes how do you get people to + + + align:start position:0% +pleasure yes how do you get people to +like hard + + align:start position:0% + + + + align:start position:0% + +problems all of you wouldn't be here if + + align:start position:0% +problems all of you wouldn't be here if + + + align:start position:0% +problems all of you wouldn't be here if +you didn't really actually like hard + + align:start position:0% +you didn't really actually like hard + + + align:start position:0% +you didn't really actually like hard +problems lots of people + + align:start position:0% + + + + align:start position:0% + +don't if you learn to hate pleasure + + align:start position:0% +don't if you learn to hate pleasure + + + align:start position:0% +don't if you learn to hate pleasure +wouldn't you learn to hate the pleasure + + align:start position:0% +wouldn't you learn to hate the pleasure + + + align:start position:0% +wouldn't you learn to hate the pleasure +get from solving problems uh if you use + + align:start position:0% +get from solving problems uh if you use + + + align:start position:0% +get from solving problems uh if you use +the same word for both but + + align:start position:0% + + + + align:start position:0% + +maybe + + align:start position:0% +maybe + + + align:start position:0% +maybe +I yeah I had a complaint about that in + + align:start position:0% +I yeah I had a complaint about that in + + + align:start position:0% +I yeah I had a complaint about that in +the really in the emotion machine book + + align:start position:0% +the really in the emotion machine book + + + align:start position:0% +the really in the emotion machine book +which is that + + align:start position:0% +which is that + + + align:start position:0% +which is that +there's + + align:start position:0% +there's + + + align:start position:0% +there's +uh that we don't have a lot of words for + + align:start position:0% +uh that we don't have a lot of words for + + + align:start position:0% +uh that we don't have a lot of words for +in common use for ways to think and + + align:start position:0% + + + + align:start position:0% + +there are a lot of emotion words but I + + align:start position:0% +there are a lot of emotion words but I + + + align:start position:0% +there are a lot of emotion words but I +don't how many synonyms for pleasure are + + align:start position:0% +don't how many synonyms for pleasure are + + + align:start position:0% +don't how many synonyms for pleasure are +there + + align:start position:0% +there + + + align:start position:0% +there +for for different + + align:start position:0% +for for different + + + align:start position:0% +for for different +kinds I can't think of + + align:start position:0% + + + + align:start position:0% + +many joy happiness those counts or those + + align:start position:0% +many joy happiness those counts or those + + + align:start position:0% +many joy happiness those counts or those +too far away yeah + + align:start position:0% + + + + align:start position:0% + +they right maybe on the other end + + align:start position:0% +they right maybe on the other end + + + align:start position:0% +they right maybe on the other end +passion no + + align:start position:0% +passion no + + + align:start position:0% +passion no +does relief + + align:start position:0% +does relief + + + align:start position:0% +does relief +count that's a very good point + + align:start position:0% +count that's a very good point + + + align:start position:0% +count that's a very good point +because a lot of Pleasures are when are + + align:start position:0% +because a lot of Pleasures are when are + + + align:start position:0% +because a lot of Pleasures are when are +when something stops + + align:start position:0% +when something stops + + + align:start position:0% +when something stops +hurting anyway I think uh yes there's a + + align:start position:0% +hurting anyway I think uh yes there's a + + + align:start position:0% +hurting anyway I think uh yes there's a +big problem of language for for thinking + + align:start position:0% +big problem of language for for thinking + + + align:start position:0% +big problem of language for for thinking +about thinking + + align:start position:0% + + + + align:start position:0% + +and I always think + + align:start position:0% +and I always think + + + align:start position:0% +and I always think +about why Galileo did + + align:start position:0% +about why Galileo did + + + align:start position:0% +about why Galileo did +discover the things that Newton + + align:start position:0% +discover the things that Newton + + + align:start position:0% +discover the things that Newton +did and I have I never asked a scholar + + align:start position:0% +did and I have I never asked a scholar + + + align:start position:0% +did and I have I never asked a scholar +but I have from Reading Galileo I have + + align:start position:0% +but I have from Reading Galileo I have + + + align:start position:0% +but I have from Reading Galileo I have +the impression that he knew that there + + align:start position:0% +the impression that he knew that there + + + align:start position:0% +the impression that he knew that there +was energy and + + align:start position:0% +was energy and + + + align:start position:0% +was energy and +momentum and he thought that they were + + align:start position:0% +momentum and he thought that they were + + + align:start position:0% +momentum and he thought that they were +and he didn't distinguish + + align:start position:0% +and he didn't distinguish + + + align:start position:0% +and he didn't distinguish +them so this this Viva which is + + align:start position:0% +them so this this Viva which is + + + align:start position:0% +them so this this Viva which is +the life of motion or I don't know what + + align:start position:0% +the life of motion or I don't know what + + + align:start position:0% +the life of motion or I don't know what +it + + align:start position:0% +it + + + align:start position:0% +it +means but + + align:start position:0% +means but + + + align:start position:0% +means but +uh but Newton knows that MV squar and MV + + align:start position:0% +uh but Newton knows that MV squar and MV + + + align:start position:0% +uh but Newton knows that MV squar and MV +are very different and I don't think + + align:start position:0% +are very different and I don't think + + + align:start position:0% +are very different and I don't think +Galileo got that and so he got + + align:start position:0% + + + + align:start position:0% + +stuck because they're both conserved + + align:start position:0% +stuck because they're both conserved + + + align:start position:0% +stuck because they're both conserved +under slightly different conditions + + align:start position:0% +under slightly different conditions + + + align:start position:0% +under slightly different conditions +isn't that terrible how many of you + + align:start position:0% +isn't that terrible how many of you + + + align:start position:0% +isn't that terrible how many of you +found that + + align:start position:0% + + + + align:start position:0% + +hard do you remember when you learned + + align:start position:0% +hard do you remember when you learned + + + align:start position:0% +hard do you remember when you learned +about momentum + + align:start position:0% + + + + align:start position:0% + +I + + align:start position:0% + + + + align:start position:0% + +count do do you mean um like in a tacit + + align:start position:0% +count do do you mean um like in a tacit + + + align:start position:0% +count do do you mean um like in a tacit +knowledge sense or the + + align:start position:0% +knowledge sense or the + + + align:start position:0% +knowledge sense or the +word is it from some grade school course + + align:start position:0% +word is it from some grade school course + + + align:start position:0% +word is it from some grade school course +or is it college early grade school must + + align:start position:0% +or is it college early grade school must + + + align:start position:0% +or is it college early grade school must +be grade school because I can't remember + + align:start position:0% +be grade school because I can't remember + + + align:start position:0% +be grade school because I can't remember +learning it + + align:start position:0% +learning it + + + align:start position:0% +learning it +so I don't know + + align:start position:0% + + + + align:start position:0% + +I have a grandson who just discovered + + align:start position:0% +I have a grandson who just discovered + + + align:start position:0% +I have a grandson who just discovered +something + + align:start position:0% +something + + + align:start position:0% +something +for the derivative of + + align:start position:0% +for the derivative of + + + align:start position:0% +for the derivative of +acceleration it's called jerk in some + + align:start position:0% +acceleration it's called jerk in some + + + align:start position:0% +acceleration it's called jerk in some +textbooks but he has a two-dimensional + + align:start position:0% +textbooks but he has a two-dimensional + + + align:start position:0% +textbooks but he has a two-dimensional +version and it took him a while to + + align:start position:0% +version and it took him a while to + + + align:start position:0% +version and it took him a while to +explain it to + + align:start position:0% + + + + align:start position:0% + +me I mean it took me a while to + + align:start position:0% +me I mean it took me a while to + + + align:start position:0% +me I mean it took me a while to +understand it + + align:start position:0% + + + + align:start position:0% + +so I think our emotion words are not + + align:start position:0% +so I think our emotion words are not + + + align:start position:0% +so I think our emotion words are not +very + + align:start position:0% +very + + + align:start position:0% +very +good + + align:start position:0% + + + + align:start position:0% + +anyway if a word is old it's probably + + align:start position:0% + + + + align:start position:0% + +not yeah so you asked uh how we should + + align:start position:0% +not yeah so you asked uh how we should + + + align:start position:0% +not yeah so you asked uh how we should +how can we increase the amount of people + + align:start position:0% +how can we increase the amount of people + + + align:start position:0% +how can we increase the amount of people +that so the hardest rounds we need gr + + align:start position:0% +that so the hardest rounds we need gr + + + align:start position:0% +that so the hardest rounds we need gr +models that solve hardest hard hard + + align:start position:0% +models that solve hardest hard hard + + + align:start position:0% +models that solve hardest hard hard +problems so for example uh professors + + align:start position:0% +problems so for example uh professors + + + align:start position:0% +problems so for example uh professors +that are role models for these people + + align:start position:0% +that are role models for these people + + + align:start position:0% +that are role models for these people +and kind of advertise that for people so + + align:start position:0% +and kind of advertise that for people so + + + align:start position:0% +and kind of advertise that for people so +an example of that like in my high + + align:start position:0% +an example of that like in my high + + + align:start position:0% +an example of that like in my high +school my high school is very science + + align:start position:0% +school my high school is very science + + + align:start position:0% +school my high school is very science +oriented in Brazil and like most of the + + align:start position:0% +oriented in Brazil and like most of the + + + align:start position:0% +oriented in Brazil and like most of the +people that come here to MIT from Brazil + + align:start position:0% +people that come here to MIT from Brazil + + + align:start position:0% +people that come here to MIT from Brazil +are from my high school and it's kind of + + align:start position:0% +are from my high school and it's kind of + + + align:start position:0% +are from my high school and it's kind of +small like there are I think two people + + align:start position:0% +small like there are I think two people + + + align:start position:0% +small like there are I think two people +that come from + + align:start position:0% +that come from + + + align:start position:0% +that come from +Brazil of this High School yeah uh at + + align:start position:0% +Brazil of this High School yeah uh at + + + align:start position:0% +Brazil of this High School yeah uh at +tapa where uh in s Paulo oh okay yeah uh + + align:start position:0% +tapa where uh in s Paulo oh okay yeah uh + + + align:start position:0% +tapa where uh in s Paulo oh okay yeah uh +like there are students that work with + + align:start position:0% +like there are students that work with + + + align:start position:0% +like there are students that work with +wingston for example there is like PhD + + align:start position:0% +wingston for example there is like PhD + + + align:start position:0% +wingston for example there is like PhD +students now in Harvard that are from + + align:start position:0% +students now in Harvard that are from + + + align:start position:0% +students now in Harvard that are from +this high school and like the professors + + align:start position:0% +this high school and like the professors + + + align:start position:0% +this high school and like the professors +they motivate the students by uh telling + + align:start position:0% +they motivate the students by uh telling + + + align:start position:0% +they motivate the students by uh telling +stories about other old people like that + + align:start position:0% +stories about other old people like that + + + align:start position:0% +stories about other old people like that +went through the same kind of thing that + + align:start position:0% +went through the same kind of thing that + + + align:start position:0% +went through the same kind of thing that +they were going through and like funny + + align:start position:0% +they were going through and like funny + + + align:start position:0% +they were going through and like funny +stories and they motivate by telling the + + align:start position:0% +stories and they motivate by telling the + + + align:start position:0% +stories and they motivate by telling the +story that the story uh the successful + + align:start position:0% +story that the story uh the successful + + + align:start position:0% +story that the story uh the successful +stories and by saying oh you could go to + + align:start position:0% +stories and by saying oh you could go to + + + align:start position:0% +stories and by saying oh you could go to +MIT which is a great place and like + + align:start position:0% +MIT which is a great place and like + + + align:start position:0% +MIT which is a great place and like +there's these funny stories about these + + align:start position:0% +there's these funny stories about these + + + align:start position:0% +there's these funny stories about these +people that they become kind of + + align:start position:0% +people that they become kind of + + + align:start position:0% +people that they become kind of +stars so can you duplicate that high + + align:start position:0% +stars so can you duplicate that high + + + align:start position:0% +stars so can you duplicate that high +school or is it unique I think it can be + + align:start position:0% +school or is it unique I think it can be + + + align:start position:0% +school or is it unique I think it can be +duplicated like you just need some smart + + align:start position:0% +duplicated like you just need some smart + + + align:start position:0% +duplicated like you just need some smart +person or like some few smart people + + align:start position:0% +person or like some few smart people + + + align:start position:0% +person or like some few smart people +that can teach like three or four that + + align:start position:0% +that can teach like three or four that + + + align:start position:0% +that can teach like three or four that +teach like the for example physics + + align:start position:0% +teach like the for example physics + + + align:start position:0% +teach like the for example physics +mathematics and chemistry like scence + + align:start position:0% +mathematics and chemistry like scence + + + align:start position:0% +mathematics and chemistry like scence +math is not a science but whatever and + + align:start position:0% +math is not a science but whatever and + + + align:start position:0% +math is not a science but whatever and +you need just some role models and tell + + align:start position:0% +you need just some role models and tell + + + align:start position:0% +you need just some role models and tell +these stories I don't think it's hard + + align:start position:0% +these stories I don't think it's hard + + + align:start position:0% +these stories I don't think it's hard +it's about motivating the people and + + align:start position:0% +it's about motivating the people and + + + align:start position:0% +it's about motivating the people and +when you're especially when you're + + align:start position:0% +when you're especially when you're + + + align:start position:0% +when you're especially when you're +young you motivate by creating role + + align:start position:0% +young you motivate by creating role + + + align:start position:0% +young you motivate by creating role +models and you say oh look look at that + + align:start position:0% +models and you say oh look look at that + + + align:start position:0% +models and you say oh look look at that +guy he doesn't have much money but he's + + align:start position:0% +guy he doesn't have much money but he's + + + align:start position:0% +guy he doesn't have much money but he's +a superstar like he's and I don't know + + align:start position:0% +a superstar like he's and I don't know + + + align:start position:0% +a superstar like he's and I don't know +that's at least how how I came here to + + align:start position:0% +that's at least how how I came here to + + + align:start position:0% +that's at least how how I came here to +my te was because there was a guy that + + align:start position:0% +my te was because there was a guy that + + + align:start position:0% +my te was because there was a guy that +was really really smart 2 years older + + align:start position:0% +was really really smart 2 years older + + + align:start position:0% +was really really smart 2 years older +than me and like + + align:start position:0% +than me and like + + + align:start position:0% +than me and like +he he was famous in high school because + + align:start position:0% +he he was famous in high school because + + + align:start position:0% +he he was famous in high school because +of here + + align:start position:0% +of here + + + align:start position:0% +of here +so well I think the Chinese has + + align:start position:0% +so well I think the Chinese has + + + align:start position:0% +so well I think the Chinese has +perfected the art like in my middle + + align:start position:0% +perfected the art like in my middle + + + align:start position:0% +perfected the art like in my middle +school or it's a culture that's that + + align:start position:0% +school or it's a culture that's that + + + align:start position:0% +school or it's a culture that's that +that pretty much has like um + + align:start position:0% +that pretty much has like um + + + align:start position:0% +that pretty much has like um +invaded every high school and every + + align:start position:0% +invaded every high school and every + + + align:start position:0% +invaded every high school and every +household to motivate people to study + + align:start position:0% +household to motivate people to study + + + align:start position:0% +household to motivate people to study +really hard setting up role models and + + align:start position:0% +really hard setting up role models and + + + align:start position:0% +really hard setting up role models and +just like + + align:start position:0% + + + + align:start position:0% + +are they science oriented very science + + align:start position:0% +are they science oriented very science + + + align:start position:0% +are they science oriented very science +oriented and not only not only do they + + align:start position:0% +oriented and not only not only do they + + + align:start position:0% +oriented and not only not only do they +work really hard um try to achieve they + + align:start position:0% +work really hard um try to achieve they + + + align:start position:0% +work really hard um try to achieve they +like you said like they don't have a lot + + align:start position:0% +like you said like they don't have a lot + + + align:start position:0% +like you said like they don't have a lot +of money whatever but they're Superstars + + align:start position:0% +of money whatever but they're Superstars + + + align:start position:0% +of money whatever but they're Superstars +not only do they believe in that they + + align:start position:0% +not only do they believe in that they + + + align:start position:0% +not only do they believe in that they +also believe in it's okay if you try + + align:start position:0% +also believe in it's okay if you try + + + align:start position:0% +also believe in it's okay if you try +very hard and then fail at the end + + align:start position:0% +very hard and then fail at the end + + + align:start position:0% +very hard and then fail at the end +that's okay also so tons of people going + + align:start position:0% +that's okay also so tons of people going + + + align:start position:0% +that's okay also so tons of people going +to really hard like math and science + + align:start position:0% +to really hard like math and science + + + align:start position:0% +to really hard like math and science +training and coming out feeling because + + align:start position:0% +training and coming out feeling because + + + align:start position:0% +training and coming out feeling because +the competition just so + + align:start position:0% +the competition just so + + + align:start position:0% +the competition just so +intense but people still do it anyway + + align:start position:0% +intense but people still do it anyway + + + align:start position:0% +intense but people still do it anyway +and you know they they Devol a lot of + + align:start position:0% +and you know they they Devol a lot of + + + align:start position:0% +and you know they they Devol a lot of +years and life into it I + + align:start position:0% +years and life into it I + + + align:start position:0% +years and life into it I +think I think that um uh probably the I + + align:start position:0% +think I think that um uh probably the I + + + align:start position:0% +think I think that um uh probably the I +think the the best way to get um get + + align:start position:0% +think the the best way to get um get + + + align:start position:0% +think the the best way to get um get +people love hard problems is to like + + align:start position:0% +people love hard problems is to like + + + align:start position:0% +people love hard problems is to like +from childhood raise them in like + + align:start position:0% +from childhood raise them in like + + + align:start position:0% +from childhood raise them in like +communities in like where all their + + align:start position:0% +communities in like where all their + + + align:start position:0% +communities in like where all their +peers are all into science because + + align:start position:0% +peers are all into science because + + + align:start position:0% +peers are all into science because +that's like you know that that's what + + align:start position:0% +that's like you know that that's what + + + align:start position:0% +that's like you know that that's what +they're into I had this experience of + + align:start position:0% +they're into I had this experience of + + + align:start position:0% +they're into I had this experience of +like switching between um in on Long + + align:start position:0% +like switching between um in on Long + + + align:start position:0% +like switching between um in on Long +Island switching between high schools + + align:start position:0% +Island switching between high schools + + + align:start position:0% +Island switching between high schools +like U switching between junior highs + + align:start position:0% +like U switching between junior highs + + + align:start position:0% +like U switching between junior highs +like I was at a junior high for like + + align:start position:0% +like I was at a junior high for like + + + align:start position:0% +like I was at a junior high for like +literally 3 miles away from the junior + + align:start position:0% +literally 3 miles away from the junior + + + align:start position:0% +literally 3 miles away from the junior +high where I ended up finishing and like + + align:start position:0% +high where I ended up finishing and like + + + align:start position:0% +high where I ended up finishing and like +the the whole atmosphere of the first + + align:start position:0% +the the whole atmosphere of the first + + + align:start position:0% +the the whole atmosphere of the first +junior high was just awful was just like + + align:start position:0% +junior high was just awful was just like + + + align:start position:0% +junior high was just awful was just like +these you know like no one cooled with + + align:start position:0% +these you know like no one cooled with + + + align:start position:0% +these you know like no one cooled with +like into science and like it was so + + align:start position:0% +like into science and like it was so + + + align:start position:0% +like into science and like it was so +it's was like very um you know like when + + align:start position:0% +it's was like very um you know like when + + + align:start position:0% +it's was like very um you know like when +you create people where like the norm is + + align:start position:0% +you create people where like the norm is + + + align:start position:0% +you create people where like the norm is +like people who are like math science + + align:start position:0% +like people who are like math science + + + align:start position:0% +like people who are like math science +nerds um if you create more of those + + align:start position:0% +nerds um if you create more of those + + + align:start position:0% +nerds um if you create more of those +places where it like you know they they + + align:start position:0% +places where it like you know they they + + + align:start position:0% +places where it like you know they they +like self-label that way um you know + + align:start position:0% +like self-label that way um you know + + + align:start position:0% +like self-label that way um you know +people who are like kind of on the Ed + + align:start position:0% +people who are like kind of on the Ed + + + align:start position:0% +people who are like kind of on the Ed +like should I Ma and math and science or + + align:start position:0% +like should I Ma and math and science or + + + align:start position:0% +like should I Ma and math and science or +should I just like you know make music + + align:start position:0% +should I just like you know make music + + + align:start position:0% +should I just like you know make music +something the rest of my life like they + + align:start position:0% +something the rest of my life like they + + + align:start position:0% +something the rest of my life like they +they'll have more they'll be more likely + + align:start position:0% +they'll have more they'll be more likely + + + align:start position:0% +they'll have more they'll be more likely +to just get swept up in that I think + + align:start position:0% +to just get swept up in that I think + + + align:start position:0% +to just get swept up in that I think +it's just like a socialized you need a + + align:start position:0% +it's just like a socialized you need a + + + align:start position:0% +it's just like a socialized you need a +place to be socialized to be + + align:start position:0% +place to be socialized to be + + + align:start position:0% +place to be socialized to be +uh it's also a question + + align:start position:0% +uh it's also a question + + + align:start position:0% +uh it's also a question +if how much does what you're + + align:start position:0% +if how much does what you're + + + align:start position:0% +if how much does what you're +learning interact with real life + + align:start position:0% +learning interact with real life + + + align:start position:0% +learning interact with real life +and I went to a high school of science + + align:start position:0% +and I went to a high school of science + + + align:start position:0% +and I went to a high school of science +which was great but I remember in grade + + align:start position:0% + + + + align:start position:0% + +school science was really nice and of + + align:start position:0% +school science was really nice and of + + + align:start position:0% +school science was really nice and of +course it was pretty hard + + align:start position:0% +course it was pretty hard + + + align:start position:0% +course it was pretty hard +sometimes but then there were other + + align:start position:0% +sometimes but then there were other + + + align:start position:0% +sometimes but then there were other +things like history and that was + + align:start position:0% +things like history and that was + + + align:start position:0% +things like history and that was +incredibly + + align:start position:0% + + + + align:start position:0% + +hard how come some kids don't find + + align:start position:0% +hard how come some kids don't find + + + align:start position:0% +hard how come some kids don't find +history is completely + + align:start position:0% +history is completely + + + align:start position:0% +history is completely +incomprehensible makes no sense and it's + + align:start position:0% +incomprehensible makes no sense and it's + + + align:start position:0% +incomprehensible makes no sense and it's +and you can't figure out what will + + align:start position:0% +and you can't figure out what will + + + align:start position:0% +and you can't figure out what will +happen next except by looking it up and + + align:start position:0% +happen next except by looking it up and + + + align:start position:0% +happen next except by looking it up and +how come most of the children don't + + align:start position:0% +how come most of the children don't + + + align:start position:0% +how come most of the children don't +realize that this is too hard to pay any + + align:start position:0% +realize that this is too hard to pay any + + + align:start position:0% +realize that this is too hard to pay any +attention to I think they do realize + + align:start position:0% +attention to I think they do realize + + + align:start position:0% +attention to I think they do realize +they don't + + align:start position:0% +they don't + + + align:start position:0% +they don't +pay do most people hate history I think + + align:start position:0% +pay do most people hate history I think + + + align:start position:0% +pay do most people hate history I think +so oh good + + align:start position:0% + + + + align:start position:0% + +really I thought people took it for + + align:start position:0% +really I thought people took it for + + + align:start position:0% +really I thought people took it for +granted and I don't know like when I + + align:start position:0% +granted and I don't know like when I + + + align:start position:0% +granted and I don't know like when I +took history + + align:start position:0% +took history + + + align:start position:0% +took history +I I think what I got out most from that + + align:start position:0% +I I think what I got out most from that + + + align:start position:0% +I I think what I got out most from that +class wasn't the history itself but + + align:start position:0% +class wasn't the history itself but + + + align:start position:0% +class wasn't the history itself but +rather like how to frame ideas and how + + align:start position:0% +rather like how to frame ideas and how + + + align:start position:0% +rather like how to frame ideas and how +to like make a good argument and support + + align:start position:0% +to like make a good argument and support + + + align:start position:0% +to like make a good argument and support +it and how to write a good paper which + + align:start position:0% +it and how to write a good paper which + + + align:start position:0% +it and how to write a good paper which +are like kind of essential life skills + + align:start position:0% +are like kind of essential life skills + + + align:start position:0% +are like kind of essential life skills +right but even the best argument isn't + + align:start position:0% +right but even the best argument isn't + + + align:start position:0% +right but even the best argument isn't +very good for in that field so it's it's + + align:start position:0% +very good for in that field so it's it's + + + align:start position:0% +very good for in that field so it's it's +very + + align:start position:0% +very + + + align:start position:0% +very +tough well I guess if if it's hard to + + align:start position:0% +tough well I guess if if it's hard to + + + align:start position:0% +tough well I guess if if it's hard to +find + + align:start position:0% +find + + + align:start position:0% +find +exceptions then that gets + + align:start position:0% +exceptions then that gets + + + align:start position:0% +exceptions then that gets +interesting even if the even even if the + + align:start position:0% +interesting even if the even even if the + + + align:start position:0% +interesting even if the even even if the +thing is + + align:start position:0% +thing is + + + align:start position:0% +thing is +wrong I'm not sure what I'm + + align:start position:0% +wrong I'm not sure what I'm + + + align:start position:0% +wrong I'm not sure what I'm +saying but + + align:start position:0% + + + + align:start position:0% + +uh if a subject has the word science in + + align:start position:0% +uh if a subject has the word science in + + + align:start position:0% +uh if a subject has the word science in +it it + + align:start position:0% +it it + + + align:start position:0% +it it +isn't social science and things I I + + align:start position:0% +isn't social science and things I I + + + align:start position:0% +isn't social science and things I I +think with the issue of science um + + align:start position:0% +think with the issue of science um + + + align:start position:0% +think with the issue of science um +there's no one solution of how to get + + align:start position:0% +there's no one solution of how to get + + + align:start position:0% +there's no one solution of how to get +people motivated in science right but + + align:start position:0% +people motivated in science right but + + + align:start position:0% +people motivated in science right but +there are several different factors so + + align:start position:0% +there are several different factors so + + + align:start position:0% +there are several different factors so +like one factor is definitely like the + + align:start position:0% +like one factor is definitely like the + + + align:start position:0% +like one factor is definitely like the +idea of having like a social support + + align:start position:0% +idea of having like a social support + + + align:start position:0% +idea of having like a social support +network whether it's like teachers who + + align:start position:0% +network whether it's like teachers who + + + align:start position:0% +network whether it's like teachers who +support you um and also having peers who + + align:start position:0% +support you um and also having peers who + + + align:start position:0% +support you um and also having peers who +don't make fun of you and ostracize you + + align:start position:0% +don't make fun of you and ostracize you + + + align:start position:0% +don't make fun of you and ostracize you +for liking science and math that's one + + align:start position:0% +for liking science and math that's one + + + align:start position:0% +for liking science and math that's one +two I think there's um the curriculum + + align:start position:0% +two I think there's um the curriculum + + + align:start position:0% +two I think there's um the curriculum +itself also has something to do with it + + align:start position:0% +itself also has something to do with it + + + align:start position:0% +itself also has something to do with it +as you said I think it helps more when + + align:start position:0% +as you said I think it helps more when + + + align:start position:0% +as you said I think it helps more when +people can connect it better to the real + + align:start position:0% +people can connect it better to the real + + + align:start position:0% +people can connect it better to the real +world to life and I think it also helps + + align:start position:0% +world to life and I think it also helps + + + align:start position:0% +world to life and I think it also helps +more when people are sort of allowed a + + align:start position:0% +more when people are sort of allowed a + + + align:start position:0% +more when people are sort of allowed a +bit of creativity if you will like like + + align:start position:0% +bit of creativity if you will like like + + + align:start position:0% +bit of creativity if you will like like +when when they're not stuff doing like + + align:start position:0% +when when they're not stuff doing like + + + align:start position:0% +when when they're not stuff doing like +gr problems all the time um and I think + + align:start position:0% +gr problems all the time um and I think + + + align:start position:0% +gr problems all the time um and I think +um another issue is like sort of + + align:start position:0% +um another issue is like sort of + + + align:start position:0% +um another issue is like sort of +presenting problems and uh Solutions and + + align:start position:0% +presenting problems and uh Solutions and + + + align:start position:0% +presenting problems and uh Solutions and +lessons to students in such a way that + + align:start position:0% +lessons to students in such a way that + + + align:start position:0% +lessons to students in such a way that +like they're sufficiently challenged but + + align:start position:0% +like they're sufficiently challenged but + + + align:start position:0% +like they're sufficiently challenged but +it's not but they're not discouraged + + align:start position:0% +it's not but they're not discouraged + + + align:start position:0% +it's not but they're not discouraged +because it's too difficult and on the + + align:start position:0% +because it's too difficult and on the + + + align:start position:0% +because it's too difficult and on the +other hand they're not bored because + + align:start position:0% +other hand they're not bored because + + + align:start position:0% +other hand they're not bored because +it's um too repetitive so I think it's + + align:start position:0% +it's um too repetitive so I think it's + + + align:start position:0% +it's um too repetitive so I think it's +sort of like a delicate balance right + + align:start position:0% +sort of like a delicate balance right + + + align:start position:0% +sort of like a delicate balance right +all these factors must be there um yeah + + align:start position:0% +all these factors must be there um yeah + + + align:start position:0% +all these factors must be there um yeah +and that also relates to the hour + + align:start position:0% +and that also relates to the hour + + + align:start position:0% +and that also relates to the hour +problem + + align:start position:0% +problem + + + align:start position:0% +problem +like when can you give someone a problem + + align:start position:0% +like when can you give someone a problem + + + align:start position:0% +like when can you give someone a problem +that that might take a whole day or + + align:start position:0% +that that might take a whole day or + + + align:start position:0% +that that might take a whole day or +two and there's no place for that + + align:start position:0% +two and there's no place for that + + + align:start position:0% +two and there's no place for that +in well there must be where in school do + + align:start position:0% +in well there must be where in school do + + + align:start position:0% +in well there must be where in school do +you get that's when you have to write a + + align:start position:0% +you get that's when you have to write a + + + align:start position:0% +you get that's when you have to write a +term paper + + align:start position:0% +term paper + + + align:start position:0% +term paper +maybe and I think another thing about + + align:start position:0% +maybe and I think another thing about + + + align:start position:0% +maybe and I think another thing about +science and Ma perhaps at least the + + align:start position:0% +science and Ma perhaps at least the + + + align:start position:0% +science and Ma perhaps at least the +school grade school incarnations of + + align:start position:0% +school grade school incarnations of + + + align:start position:0% +school grade school incarnations of +those subjects is that they tend to + + align:start position:0% +those subjects is that they tend to + + + align:start position:0% +those subjects is that they tend to +be a lot more isolating than subjects in + + align:start position:0% +be a lot more isolating than subjects in + + + align:start position:0% +be a lot more isolating than subjects in +the humanities in the sense that like + + align:start position:0% +the humanities in the sense that like + + + align:start position:0% +the humanities in the sense that like +when you're stuck at home doing science + + align:start position:0% +when you're stuck at home doing science + + + align:start position:0% +when you're stuck at home doing science +and math problems you're always by + + align:start position:0% +and math problems you're always by + + + align:start position:0% +and math problems you're always by +yourself and you're always encouraged to + + align:start position:0% +yourself and you're always encouraged to + + + align:start position:0% +yourself and you're always encouraged to +you know + + align:start position:0% +you know + + + align:start position:0% +you know +like essentially like quarantine + + align:start position:0% +like essentially like quarantine + + + align:start position:0% +like essentially like quarantine +yourself to like study these things and + + align:start position:0% +yourself to like study these things and + + + align:start position:0% +yourself to like study these things and +come up with Solutions whereas classes + + align:start position:0% +come up with Solutions whereas classes + + + align:start position:0% +come up with Solutions whereas classes +in history or foreign languages or + + align:start position:0% +in history or foreign languages or + + + align:start position:0% +in history or foreign languages or +English are more like discussions based + + align:start position:0% +English are more like discussions based + + + align:start position:0% +English are more like discussions based +and actually I think that's sort of I + + align:start position:0% +and actually I think that's sort of I + + + align:start position:0% +and actually I think that's sort of I +don't know because in real life when you + + align:start position:0% +don't know because in real life when you + + + align:start position:0% +don't know because in real life when you +solve scientific problems you are + + align:start position:0% +solve scientific problems you are + + + align:start position:0% +solve scientific problems you are +working on a team a lot of the time and + + align:start position:0% +working on a team a lot of the time and + + + align:start position:0% +working on a team a lot of the time and +you have to communicate your ideas and + + align:start position:0% +you have to communicate your ideas and + + + align:start position:0% +you have to communicate your ideas and +you kind of like are working together + + align:start position:0% +you kind of like are working together + + + align:start position:0% +you kind of like are working together +but somehow like in grade school you + + align:start position:0% +but somehow like in grade school you + + + align:start position:0% +but somehow like in grade school you +you're stuck you know working on these + + align:start position:0% +you're stuck you know working on these + + + align:start position:0% +you're stuck you know working on these +problems by yourself and I think that + + align:start position:0% +problems by yourself and I think that + + + align:start position:0% +problems by yourself and I think that +might also be a contributing factor + + align:start position:0% +might also be a contributing factor + + + align:start position:0% +might also be a contributing factor +interesting well if you trying to solve + + align:start position:0% +interesting well if you trying to solve + + + align:start position:0% +interesting well if you trying to solve +a geometry + + align:start position:0% +a geometry + + + align:start position:0% +a geometry +problem have you ever solv the problem + + align:start position:0% +problem have you ever solv the problem + + + align:start position:0% +problem have you ever solv the problem +working with someone + + align:start position:0% +working with someone + + + align:start position:0% +working with someone +else does it help or they they always + + align:start position:0% +else does it help or they they always + + + align:start position:0% +else does it help or they they always +interrupting you so you can't + + align:start position:0% +interrupting you so you can't + + + align:start position:0% +interrupting you so you can't +concentrate in undergrad for instance + + align:start position:0% +concentrate in undergrad for instance + + + align:start position:0% +concentrate in undergrad for instance +like there there there'll be office + + align:start position:0% +like there there there'll be office + + + align:start position:0% +like there there there'll be office +hours or like open Office hours where + + align:start position:0% +hours or like open Office hours where + + + align:start position:0% +hours or like open Office hours where +students all come together and kind of + + align:start position:0% +students all come together and kind of + + + align:start position:0% +students all come together and kind of +like help each other a little or give + + align:start position:0% +like help each other a little or give + + + align:start position:0% +like help each other a little or give +hints things like that and it tends to + + align:start position:0% +hints things like that and it tends to + + + align:start position:0% +hints things like that and it tends to +help for at least you know most people + + align:start position:0% +help for at least you know most people + + + align:start position:0% +help for at least you know most people +but I guess I'm mostly um encountering + + align:start position:0% +but I guess I'm mostly um encountering + + + align:start position:0% +but I guess I'm mostly um encountering +the other people who go to these things + + align:start position:0% +the other people who go to these things + + + align:start position:0% +the other people who go to these things +I think in grade school it's too um when + + align:start position:0% +I think in grade school it's too um when + + + align:start position:0% +I think in grade school it's too um when +the problems that you have to master are + + align:start position:0% +the problems that you have to master are + + + align:start position:0% +the problems that you have to master are +too simple um are to like that it only + + align:start position:0% +too simple um are to like that it only + + + align:start position:0% +too simple um are to like that it only +requires like one flash of insight to + + align:start position:0% +requires like one flash of insight to + + + align:start position:0% +requires like one flash of insight to +solve the problem and that that flash of + + align:start position:0% +solve the problem and that that flash of + + + align:start position:0% +solve the problem and that that flash of +insight you're supposed to work towards + + align:start position:0% +insight you're supposed to work towards + + + align:start position:0% +insight you're supposed to work towards +on your own whereas like if there's like + + align:start position:0% +on your own whereas like if there's like + + + align:start position:0% +on your own whereas like if there's like +a multi like a like a problem that takes + + align:start position:0% +a multi like a like a problem that takes + + + align:start position:0% +a multi like a like a problem that takes +a day to solve that takes like five + + align:start position:0% +a day to solve that takes like five + + + align:start position:0% +a day to solve that takes like five +flashes of insight like consecutive + + align:start position:0% +flashes of insight like consecutive + + + align:start position:0% +flashes of insight like consecutive +flashes of insight to solve it um like a + + align:start position:0% +flashes of insight to solve it um like a + + + align:start position:0% +flashes of insight to solve it um like a +collaborative okay here's a + + align:start position:0% + + + + align:start position:0% + +problem there's an isoc these two sides + + align:start position:0% +problem there's an isoc these two sides + + + align:start position:0% +problem there's an isoc these two sides +are equal so that's an isoceles + + align:start position:0% +are equal so that's an isoceles + + + align:start position:0% +are equal so that's an isoceles +triangle + + align:start position:0% +triangle + + + align:start position:0% +triangle +so + + align:start position:0% + + + + align:start position:0% + +now here two angle bis sectors + + align:start position:0% + + + + align:start position:0% + +okay so if the triangle is isoceles + + align:start position:0% +okay so if the triangle is isoceles + + + align:start position:0% +okay so if the triangle is isoceles +prove that the angle bisectors are + + align:start position:0% + + + + align:start position:0% + +equal has anybody proved it + + align:start position:0% + + + + align:start position:0% + +yet well it's very + + align:start position:0% +yet well it's very + + + align:start position:0% +yet well it's very +easy but here's your + + align:start position:0% +easy but here's your + + + align:start position:0% +easy but here's your +homework if you have a triangle and the + + align:start position:0% +homework if you have a triangle and the + + + align:start position:0% +homework if you have a triangle and the +angle bis sectors are equal + + align:start position:0% +angle bis sectors are equal + + + align:start position:0% +angle bis sectors are equal +prove that the Sid corresponding sides + + align:start position:0% +prove that the Sid corresponding sides + + + align:start position:0% +prove that the Sid corresponding sides +are + + align:start position:0% +are + + + align:start position:0% +are +equal and see who can get a the shortest + + align:start position:0% +equal and see who can get a the shortest + + + align:start position:0% +equal and see who can get a the shortest +proof it's pretty hard have you ever + + align:start position:0% +proof it's pretty hard have you ever + + + align:start position:0% +proof it's pretty hard have you ever +read the essay by Paul oart called a + + align:start position:0% +read the essay by Paul oart called a + + + align:start position:0% +read the essay by Paul oart called a +mathematician's + + align:start position:0% +mathematician's + + + align:start position:0% +mathematician's +lament what's the third word a + + align:start position:0% +lament what's the third word a + + + align:start position:0% +lament what's the third word a +mathematician's lament living lament + + align:start position:0% +mathematician's lament living lament + + + align:start position:0% +mathematician's lament living lament +lament no I don't think so oh um it it + + align:start position:0% +lament no I don't think so oh um it it + + + align:start position:0% +lament no I don't think so oh um it it +sort of his critique on math education + + align:start position:0% +sort of his critique on math education + + + align:start position:0% +sort of his critique on math education +um in America it's quite interesting + + align:start position:0% +um in America it's quite interesting + + + align:start position:0% +um in America it's quite interesting +yeah I was just thinking that well you + + align:start position:0% +yeah I was just thinking that well you + + + align:start position:0% +yeah I was just thinking that well you +mentioned that mathematics tends to be + + align:start position:0% +mentioned that mathematics tends to be + + + align:start position:0% +mentioned that mathematics tends to be +pretty slowly but well Marvin brought up + + align:start position:0% +pretty slowly but well Marvin brought up + + + align:start position:0% +pretty slowly but well Marvin brought up +that and I was thinking that for many + + align:start position:0% +that and I was thinking that for many + + + align:start position:0% +that and I was thinking that for many +kinds of mathematical problems you + + align:start position:0% +kinds of mathematical problems you + + + align:start position:0% +kinds of mathematical problems you +can + + align:start position:0% +can + + + align:start position:0% +can +prove theorems in different ways and + + align:start position:0% +prove theorems in different ways and + + + align:start position:0% +prove theorems in different ways and +then like somebody comes up with a proof + + align:start position:0% +then like somebody comes up with a proof + + + align:start position:0% +then like somebody comes up with a proof +and then you then you challenge that + + align:start position:0% +and then you then you challenge that + + + align:start position:0% +and then you then you challenge that +okay now somebody else find another kind + + align:start position:0% +okay now somebody else find another kind + + + align:start position:0% +okay now somebody else find another kind +of a pro better you have a homework okay + + align:start position:0% +of a pro better you have a homework okay + + + align:start position:0% +of a pro better you have a homework okay +come up with four different ways of + + align:start position:0% +come up with four different ways of + + + align:start position:0% +come up with four different ways of +proving this thing and + + align:start position:0% +proving this thing and + + + align:start position:0% +proving this thing and +always everything goes so if you want to + + align:start position:0% +always everything goes so if you want to + + + align:start position:0% +always everything goes so if you want to +work together with people you can pull + + align:start position:0% +work together with people you can pull + + + align:start position:0% +work together with people you can pull +up yours and so + + align:start position:0% +up yours and so + + + align:start position:0% +up yours and so +on that's why Fineman said he was so + + align:start position:0% +on that's why Fineman said he was so + + + align:start position:0% +on that's why Fineman said he was so +great that is when he had a physics + + align:start position:0% +great that is when he had a physics + + + align:start position:0% +great that is when he had a physics +problem he forced himself to find + + align:start position:0% +problem he forced himself to find + + + align:start position:0% +problem he forced himself to find +several different ways and he said all + + align:start position:0% +several different ways and he said all + + + align:start position:0% +several different ways and he said all +of his friends when they learned quantum + + align:start position:0% +of his friends when they learned quantum + + + align:start position:0% +of his friends when they learned quantum +mechanics either learned the Heisenberg + + align:start position:0% +mechanics either learned the Heisenberg + + + align:start position:0% +mechanics either learned the Heisenberg +Matrix method or the schinger + + align:start position:0% +Matrix method or the schinger + + + align:start position:0% +Matrix method or the schinger +differential equation method or the dur + + align:start position:0% +differential equation method or the dur + + + align:start position:0% +differential equation method or the dur +technique + + align:start position:0% +technique + + + align:start position:0% +technique +and whenever he had a problem he he + + align:start position:0% +and whenever he had a problem he he + + + align:start position:0% +and whenever he had a problem he he +would solve it by all known + + align:start position:0% +would solve it by all known + + + align:start position:0% +would solve it by all known +techniques and then in later life he + + align:start position:0% +techniques and then in later life he + + + align:start position:0% +techniques and then in later life he +rarely got stuck where most people did + + align:start position:0% +rarely got stuck where most people did + + + align:start position:0% +rarely got stuck where most people did +yeah so uh related to that the best + + align:start position:0% +yeah so uh related to that the best + + + align:start position:0% +yeah so uh related to that the best +mathematicians that I know like are + + align:start position:0% +mathematicians that I know like are + + + align:start position:0% +mathematicians that I know like are +people that they stay with a problem and + + align:start position:0% +people that they stay with a problem and + + + align:start position:0% +people that they stay with a problem and +they and they solve by themselves they + + align:start position:0% +they and they solve by themselves they + + + align:start position:0% +they and they solve by themselves they +don't go and look for the solutions or + + align:start position:0% +don't go and look for the solutions or + + + align:start position:0% +don't go and look for the solutions or +like ask other people they try to solve + + align:start position:0% +like ask other people they try to solve + + + align:start position:0% +like ask other people they try to solve +by themselves and I believe it's just + + align:start position:0% +by themselves and I believe it's just + + + align:start position:0% +by themselves and I believe it's just +because the way we created + + align:start position:0% +because the way we created + + + align:start position:0% +because the way we created +Pathways and I believe that uh but there + + align:start position:0% +Pathways and I believe that uh but there + + + align:start position:0% +Pathways and I believe that uh but there +are quite a few pairs of + + align:start position:0% +are quite a few pairs of + + + align:start position:0% +are quite a few pairs of +mathematicians yeah but like when you're + + align:start position:0% +mathematicians yeah but like when you're + + + align:start position:0% +mathematicians yeah but like when you're +young you should try to solve the + + align:start position:0% +young you should try to solve the + + + align:start position:0% +young you should try to solve the +problems by yourself at least when + + align:start position:0% +problems by yourself at least when + + + align:start position:0% +problems by yourself at least when +you're in middle school or high school + + align:start position:0% +you're in middle school or high school + + + align:start position:0% +you're in middle school or high school +and then you create these Pathways right + + align:start position:0% +and then you create these Pathways right + + + align:start position:0% +and then you create these Pathways right +maybe when you get older the problems + + align:start position:0% +maybe when you get older the problems + + + align:start position:0% +maybe when you get older the problems +are too hard and + + align:start position:0% +are too hard and + + + align:start position:0% +are too hard and +then and then it doesn't help to solve + + align:start position:0% +then and then it doesn't help to solve + + + align:start position:0% +then and then it doesn't help to solve +the problem by yourself cuz you're not + + align:start position:0% +the problem by yourself cuz you're not + + + align:start position:0% +the problem by yourself cuz you're not +going to solve harder problems than + + align:start position:0% +going to solve harder problems than + + + align:start position:0% +going to solve harder problems than +those ones so + + align:start position:0% + + + + align:start position:0% + +how many of you have ever solved a math + + align:start position:0% +how many of you have ever solved a math + + + align:start position:0% +how many of you have ever solved a math +problem with someone + + align:start position:0% +problem with someone + + + align:start position:0% +problem with someone +else quite a + + align:start position:0% + + + + align:start position:0% + +few I remember being in a boat with + + align:start position:0% +few I remember being in a boat with + + + align:start position:0% +few I remember being in a boat with +Seymour peer solving some really hard + + align:start position:0% + + + + align:start position:0% + +problem + + align:start position:0% +problem + + + align:start position:0% +problem +and after a while he got tired of it and + + align:start position:0% +and after a while he got tired of it and + + + align:start position:0% +and after a while he got tired of it and +slipped into the water and went swimming + + align:start position:0% +slipped into the water and went swimming + + + align:start position:0% +slipped into the water and went swimming +around and I I said come + + align:start position:0% +around and I I said come + + + align:start position:0% +around and I I said come +back he said why and I said I'll tell + + align:start position:0% +back he said why and I said I'll tell + + + align:start position:0% +back he said why and I said I'll tell +you when you get here and he got back + + align:start position:0% +you when you get here and he got back + + + align:start position:0% +you when you get here and he got back +before the + + align:start position:0% +before the + + + align:start position:0% +before the +shark did I ever tell you + + align:start position:0% + + + + align:start position:0% + +about we thought it was a dolphin for a + + align:start position:0% +about we thought it was a dolphin for a + + + align:start position:0% +about we thought it was a dolphin for a +while but but it had this fin on the + + align:start position:0% +while but but it had this fin on the + + + align:start position:0% +while but but it had this fin on the +back that didn't seem quite right + + align:start position:0% +back that didn't seem quite right + + + align:start position:0% +back that didn't seem quite right +[Applause] + + align:start position:0% + + + + align:start position:0% + +anyway I did a lot of solving + + align:start position:0% +anyway I did a lot of solving + + + align:start position:0% +anyway I did a lot of solving +with I don't remember ever solving a + + align:start position:0% +with I don't remember ever solving a + + + align:start position:0% +with I don't remember ever solving a +hard problem with three + + align:start position:0% + + + + align:start position:0% + +people that's + + align:start position:0% +people that's + + + align:start position:0% +people that's +nice well you have the simple physics + + align:start position:0% +nice well you have the simple physics + + + align:start position:0% +nice well you have the simple physics +problem of measuring the height of this + + align:start position:0% +problem of measuring the height of this + + + align:start position:0% +problem of measuring the height of this +it says low battery is that a + + align:start position:0% + + + + align:start position:0% + +coincidence oh ringing the bell must + + align:start position:0% +coincidence oh ringing the bell must + + + align:start position:0% +coincidence oh ringing the bell must +have dropped the + + align:start position:0% + + + + align:start position:0% + +voltage the low battery went on about 1 + + align:start position:0% +voltage the low battery went on about 1 + + + align:start position:0% +voltage the low battery went on about 1 +second after I stopped the quack \ No newline at end of file diff --git a/MRJUxK-hhYw.txt b/MRJUxK-hhYw.txt new file mode 100644 index 0000000000000000000000000000000000000000..22584cb18c5df314fc62109aed002c3857dc3299 --- /dev/null +++ b/MRJUxK-hhYw.txt @@ -0,0 +1,7299 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so last time we were talking + + align:start position:0% +ocw.mit.edu so last time we were talking + + + align:start position:0% +ocw.mit.edu so last time we were talking +about + + align:start position:0% +about + + + align:start position:0% +about +um we're talking about the general + + align:start position:0% +um we're talking about the general + + + align:start position:0% +um we're talking about the general +interactions that are presence in a + + align:start position:0% +interactions that are presence in a + + + align:start position:0% +interactions that are presence in a +chemical bond and we were in particular + + align:start position:0% +chemical bond and we were in particular + + + align:start position:0% +chemical bond and we were in particular +looking at the energy of + + align:start position:0% +looking at the energy of + + + align:start position:0% +looking at the energy of +interaction here as we brought two + + align:start position:0% +interaction here as we brought two + + + align:start position:0% +interaction here as we brought two +hydrogen atoms together so we're looking + + align:start position:0% +hydrogen atoms together so we're looking + + + align:start position:0% +hydrogen atoms together so we're looking +at that energy of interaction as a + + align:start position:0% +at that energy of interaction as a + + + align:start position:0% +at that energy of interaction as a +function of the distance R between these + + align:start position:0% +function of the distance R between these + + + align:start position:0% +function of the distance R between these +two + + align:start position:0% + + + + align:start position:0% + +nuclei and uh we saw of course way out + + align:start position:0% +nuclei and uh we saw of course way out + + + align:start position:0% +nuclei and uh we saw of course way out +here the energy of interaction was- 20 + + align:start position:0% +here the energy of interaction was- 20 + + + align:start position:0% +here the energy of interaction was- 20 +2,624 K per + + align:start position:0% +2,624 K per + + + align:start position:0% +2,624 K per +mole as we brought the two hydrogen + + align:start position:0% +mole as we brought the two hydrogen + + + align:start position:0% +mole as we brought the two hydrogen +atoms in closer + + align:start position:0% +atoms in closer + + + align:start position:0% +atoms in closer +together that interaction energy went + + align:start position:0% +together that interaction energy went + + + align:start position:0% +together that interaction energy went +down it became a maximum negative value + + align:start position:0% +down it became a maximum negative value + + + align:start position:0% +down it became a maximum negative value +at sum r that R is the equilibrium Bond + + align:start position:0% +at sum r that R is the equilibrium Bond + + + align:start position:0% +at sum r that R is the equilibrium Bond +length and then as you try to push the + + align:start position:0% +length and then as you try to push the + + + align:start position:0% +length and then as you try to push the +two nuclei closer together the energy of + + align:start position:0% +two nuclei closer together the energy of + + + align:start position:0% +two nuclei closer together the energy of +interaction goes up + + align:start position:0% +interaction goes up + + + align:start position:0% +interaction goes up +again so far up that when you get them + + align:start position:0% +again so far up that when you get them + + + align:start position:0% +again so far up that when you get them +really close the energy of interaction + + align:start position:0% +really close the energy of interaction + + + align:start position:0% +really close the energy of interaction +is greater than that of the two + + align:start position:0% +is greater than that of the two + + + align:start position:0% +is greater than that of the two +separated hydrogen atoms and so in this + + align:start position:0% +separated hydrogen atoms and so in this + + + align:start position:0% +separated hydrogen atoms and so in this +region the hydrogen atoms are no longer + + align:start position:0% +region the hydrogen atoms are no longer + + + align:start position:0% +region the hydrogen atoms are no longer +bound so wherever this energy is lower + + align:start position:0% +bound so wherever this energy is lower + + + align:start position:0% +bound so wherever this energy is lower +than that of the separated a hydrogen + + align:start position:0% +than that of the separated a hydrogen + + + align:start position:0% +than that of the separated a hydrogen +atom limit you have a bound molecule + + align:start position:0% +atom limit you have a bound molecule + + + align:start position:0% +atom limit you have a bound molecule +this was the attractive part of the + + align:start position:0% +this was the attractive part of the + + + align:start position:0% +this was the attractive part of the +potential this was the well depth or the + + align:start position:0% +potential this was the well depth or the + + + align:start position:0% +potential this was the well depth or the +bond Association energy measured from + + align:start position:0% +bond Association energy measured from + + + align:start position:0% +bond Association energy measured from +here to here that's how much energy + + align:start position:0% +here to here that's how much energy + + + align:start position:0% +here to here that's how much energy +you'd have to put in to pull the two + + align:start position:0% +you'd have to put in to pull the two + + + align:start position:0% +you'd have to put in to pull the two +hydrogens + + align:start position:0% +hydrogens + + + align:start position:0% +hydrogens +apart this is the repulsive region of + + align:start position:0% +apart this is the repulsive region of + + + align:start position:0% +apart this is the repulsive region of +that interaction + + align:start position:0% +that interaction + + + align:start position:0% +that interaction +potential all right we were talking + + align:start position:0% +potential all right we were talking + + + align:start position:0% +potential all right we were talking +about how that curve that energy was + + align:start position:0% +about how that curve that energy was + + + align:start position:0% +about how that curve that energy was +really the sum of three + + align:start position:0% +really the sum of three + + + align:start position:0% +really the sum of three +components it was the + + align:start position:0% +components it was the + + + align:start position:0% +components it was the +sum that energy of + + align:start position:0% +sum that energy of + + + align:start position:0% +sum that energy of +interaction was the sum of the nuclear + + align:start position:0% +interaction was the sum of the nuclear + + + align:start position:0% +interaction was the sum of the nuclear +nuclear + + align:start position:0% + + + + align:start position:0% + +repulsion that + + align:start position:0% +repulsion that + + + align:start position:0% +repulsion that +is the repulsion between the nucleus of + + align:start position:0% +is the repulsion between the nucleus of + + + align:start position:0% +is the repulsion between the nucleus of +this hydrogen and the nucleus of that + + align:start position:0% +this hydrogen and the nucleus of that + + + align:start position:0% +this hydrogen and the nucleus of that +hydrogen in addition to that nuclear + + align:start position:0% +hydrogen in addition to that nuclear + + + align:start position:0% +hydrogen in addition to that nuclear +nuclear + + align:start position:0% +nuclear + + + align:start position:0% +nuclear +repulsion there is the electron nuclear + + align:start position:0% + + + + align:start position:0% + +attraction the electron nuclear + + align:start position:0% +attraction the electron nuclear + + + align:start position:0% +attraction the electron nuclear +attraction between the + + align:start position:0% +attraction between the + + + align:start position:0% +attraction between the +electron on the original + + align:start position:0% +electron on the original + + + align:start position:0% +electron on the original +nucleus and when the two hydrogens get + + align:start position:0% +nucleus and when the two hydrogens get + + + align:start position:0% +nucleus and when the two hydrogens get +close enough the electron attraction + + align:start position:0% +close enough the electron attraction + + + align:start position:0% +close enough the electron attraction +between the other + + align:start position:0% +between the other + + + align:start position:0% +between the other +nucleus and then finally there's the + + align:start position:0% +nucleus and then finally there's the + + + align:start position:0% +nucleus and then finally there's the +electron electron + + align:start position:0% +electron electron + + + align:start position:0% +electron electron +repulsion when these two hydrogen atoms + + align:start position:0% +repulsion when these two hydrogen atoms + + + align:start position:0% +repulsion when these two hydrogen atoms +come so + + align:start position:0% +come so + + + align:start position:0% +come so +close the electrons now are going to + + align:start position:0% +close the electrons now are going to + + + align:start position:0% +close the electrons now are going to +repel and so this curve is actually the + + align:start position:0% +repel and so this curve is actually the + + + align:start position:0% +repel and so this curve is actually the +sum of those three + + align:start position:0% +sum of those three + + + align:start position:0% +sum of those three +contributions and what we were trying to + + align:start position:0% +contributions and what we were trying to + + + align:start position:0% +contributions and what we were trying to +do last time is + + align:start position:0% +do last time is + + + align:start position:0% +do last time is +to is to look at the dependence of of + + align:start position:0% +to is to look at the dependence of of + + + align:start position:0% +to is to look at the dependence of of +these interactions individually on R and + + align:start position:0% +these interactions individually on R and + + + align:start position:0% +these interactions individually on R and +then we wanted to sum them + + align:start position:0% +then we wanted to sum them + + + align:start position:0% +then we wanted to sum them +up to see why we actually have the shape + + align:start position:0% +up to see why we actually have the shape + + + align:start position:0% +up to see why we actually have the shape +of this interaction potential that we do + + align:start position:0% +of this interaction potential that we do + + + align:start position:0% +of this interaction potential that we do +we're trying to decompose this we're + + align:start position:0% +we're trying to decompose this we're + + + align:start position:0% +we're trying to decompose this we're +trying to + + align:start position:0% +trying to + + + align:start position:0% +trying to +understand over what regions of I + + align:start position:0% +understand over what regions of I + + + align:start position:0% +understand over what regions of I +are which one of these interaction + + align:start position:0% +are which one of these interaction + + + align:start position:0% +are which one of these interaction +energies is + + align:start position:0% +energies is + + + align:start position:0% +energies is +dominant okay that's what we're + + align:start position:0% +dominant okay that's what we're + + + align:start position:0% +dominant okay that's what we're +doing all right and I think last time we + + align:start position:0% +doing all right and I think last time we + + + align:start position:0% +doing all right and I think last time we +started in the sense + + align:start position:0% +started in the sense + + + align:start position:0% +started in the sense +that we recognized what the r dependence + + align:start position:0% +that we recognized what the r dependence + + + align:start position:0% +that we recognized what the r dependence +was for the nuclear nuclear repulsion + + align:start position:0% +was for the nuclear nuclear repulsion + + + align:start position:0% +was for the nuclear nuclear repulsion +right the nuclear nuclear + + align:start position:0% +right the nuclear nuclear + + + align:start position:0% +right the nuclear nuclear +repulsion is just the kolom interaction + + align:start position:0% +repulsion is just the kolom interaction + + + align:start position:0% +repulsion is just the kolom interaction +energy between two like positive charges + + align:start position:0% +energy between two like positive charges + + + align:start position:0% +energy between two like positive charges +that nuclear nuclear repulsion was e^2 + + align:start position:0% +that nuclear nuclear repulsion was e^2 + + + align:start position:0% +that nuclear nuclear repulsion was e^2 +over 4 Pi Epsilon time + + align:start position:0% +over 4 Pi Epsilon time + + + align:start position:0% +over 4 Pi Epsilon time +R and + + align:start position:0% +R and + + + align:start position:0% +R and +so that + + align:start position:0% +so that + + + align:start position:0% +so that +component I could easily + + align:start position:0% +component I could easily + + + align:start position:0% +component I could easily +draw and I did draw it last time I think + + align:start position:0% +draw and I did draw it last time I think + + + align:start position:0% +draw and I did draw it last time I think +this is a one over our dependence right + + align:start position:0% +this is a one over our dependence right + + + align:start position:0% +this is a one over our dependence right +this is the e 2 over e^ 2 over 4 Pi + + align:start position:0% +this is the e 2 over e^ 2 over 4 Pi + + + align:start position:0% +this is the e 2 over e^ 2 over 4 Pi +Epsilon + + align:start position:0% + + + + align:start position:0% + +R all right so that was one of them now + + align:start position:0% +R all right so that was one of them now + + + align:start position:0% +R all right so that was one of them now +next these two + + align:start position:0% +next these two + + + align:start position:0% +next these two +terms these two terms are what I'm going + + align:start position:0% +terms these two terms are what I'm going + + + align:start position:0% +terms these two terms are what I'm going +to call the + + align:start position:0% +to call the + + + align:start position:0% +to call the +electron + + align:start position:0% + + + + align:start position:0% + +interactions because both of them + + align:start position:0% +interactions because both of them + + + align:start position:0% +interactions because both of them +involved the electron this one didn't + + align:start position:0% +involved the electron this one didn't + + + align:start position:0% +involved the electron this one didn't +this was just the + + align:start position:0% + + + + align:start position:0% + +nucleus it turns out that I don't have + + align:start position:0% +nucleus it turns out that I don't have + + + align:start position:0% +nucleus it turns out that I don't have +have a nice simple way to tell you what + + align:start position:0% +have a nice simple way to tell you what + + + align:start position:0% +have a nice simple way to tell you what +the r dependence between the nuclei will + + align:start position:0% +the r dependence between the nuclei will + + + align:start position:0% +the r dependence between the nuclei will +be for the electron nuclear + + align:start position:0% +be for the electron nuclear + + + align:start position:0% +be for the electron nuclear +attraction nor do I have a nice simple + + align:start position:0% +attraction nor do I have a nice simple + + + align:start position:0% +attraction nor do I have a nice simple +way to figure out what the r + + align:start position:0% +way to figure out what the r + + + align:start position:0% +way to figure out what the r +dependence will be for the electron + + align:start position:0% +dependence will be for the electron + + + align:start position:0% +dependence will be for the electron +electron + + align:start position:0% +electron + + + align:start position:0% +electron +repulsion I can't do that without + + align:start position:0% +repulsion I can't do that without + + + align:start position:0% +repulsion I can't do that without +actually solving the schinger + + align:start position:0% +actually solving the schinger + + + align:start position:0% +actually solving the schinger +equation all right so I don't have a + + align:start position:0% +equation all right so I don't have a + + + align:start position:0% +equation all right so I don't have a +simple way to break that down + + align:start position:0% +simple way to break that down + + + align:start position:0% +simple way to break that down +however what I can do is I can + + align:start position:0% +however what I can do is I can + + + align:start position:0% +however what I can do is I can +estimate what the sum of these electron + + align:start position:0% +estimate what the sum of these electron + + + align:start position:0% +estimate what the sum of these electron +interactions are at two + + align:start position:0% + + + + align:start position:0% + +extremes is this + + align:start position:0% +extremes is this + + + align:start position:0% +extremes is this +noisy can you hear me yes okay I can see + + align:start position:0% +noisy can you hear me yes okay I can see + + + align:start position:0% +noisy can you hear me yes okay I can see +why it's + + align:start position:0% + + + + align:start position:0% + +noisy it's got thing sticking on it + + align:start position:0% +noisy it's got thing sticking on it + + + align:start position:0% +noisy it's got thing sticking on it +which is + + align:start position:0% + + + + align:start position:0% + +rattling all + + align:start position:0% + + + + align:start position:0% + +right you might get somebody in there to + + align:start position:0% +right you might get somebody in there to + + + align:start position:0% +right you might get somebody in there to +try to fix that thanks okay I do know + + align:start position:0% +try to fix that thanks okay I do know + + + align:start position:0% +try to fix that thanks okay I do know +what it is at two extremes I know what + + align:start position:0% +what it is at two extremes I know what + + + align:start position:0% +what it is at two extremes I know what +those sums of those interactions are for + + align:start position:0% +those sums of those interactions are for + + + align:start position:0% +those sums of those interactions are for +very large R and I know what it is for R + + align:start position:0% +very large R and I know what it is for R + + + align:start position:0% +very large R and I know what it is for R +equals z so what I'm going to do is I'm + + align:start position:0% +equals z so what I'm going to do is I'm + + + align:start position:0% +equals z so what I'm going to do is I'm +going to calculate it for r equal + + align:start position:0% +going to calculate it for r equal + + + align:start position:0% +going to calculate it for r equal +infinity and r equal Z and I'm going to + + align:start position:0% +infinity and r equal Z and I'm going to + + + align:start position:0% +infinity and r equal Z and I'm going to +then put it on this plot and then to + + align:start position:0% +then put it on this plot and then to + + + align:start position:0% +then put it on this plot and then to +just uh estimate what the r dependence + + align:start position:0% +just uh estimate what the r dependence + + + align:start position:0% +just uh estimate what the r dependence +is I'm going to draw a line from that + + align:start position:0% +is I'm going to draw a line from that + + + align:start position:0% +is I'm going to draw a line from that +point to that point that's the best I + + align:start position:0% +point to that point that's the best I + + + align:start position:0% +point to that point that's the best I +can do okay so let's uh let's do + + align:start position:0% + + + + align:start position:0% + +that okay let me start with uh this + + align:start position:0% +that okay let me start with uh this + + + align:start position:0% +that okay let me start with uh this +energy of interaction at r equal + + align:start position:0% +energy of interaction at r equal + + + align:start position:0% +energy of interaction at r equal +Infinity so I want to + + align:start position:0% +Infinity so I want to + + + align:start position:0% +Infinity so I want to +evaluate what the um repulsive + + align:start position:0% +evaluate what the um repulsive + + + align:start position:0% +evaluate what the um repulsive +interaction is between the electrons at + + align:start position:0% +interaction is between the electrons at + + + align:start position:0% +interaction is between the electrons at +r equal Infinity what is that + + align:start position:0% +r equal Infinity what is that + + + align:start position:0% +r equal Infinity what is that +interaction + + align:start position:0% +interaction + + + align:start position:0% +interaction +Energy Zero it's zero + + align:start position:0% +Energy Zero it's zero + + + align:start position:0% +Energy Zero it's zero +because the electrons are so far apart + + align:start position:0% +because the electrons are so far apart + + + align:start position:0% +because the electrons are so far apart +at r equal + + align:start position:0% +at r equal + + + align:start position:0% +at r equal +Infinity that there's no interaction + + align:start position:0% +Infinity that there's no interaction + + + align:start position:0% +Infinity that there's no interaction +energy right it's the repulsive + + align:start position:0% +energy right it's the repulsive + + + align:start position:0% +energy right it's the repulsive +interaction it's this kind of + + align:start position:0% +interaction it's this kind of + + + align:start position:0% +interaction it's this kind of +interaction r equal Infinity hey that's + + align:start position:0% +interaction r equal Infinity hey that's + + + align:start position:0% +interaction r equal Infinity hey that's +going to be zero + + align:start position:0% +going to be zero + + + align:start position:0% +going to be zero +good but now this term this electron + + align:start position:0% +good but now this term this electron + + + align:start position:0% +good but now this term this electron +nuclear + + align:start position:0% +nuclear + + + align:start position:0% +nuclear +attraction when the two hydrogen atoms + + align:start position:0% +attraction when the two hydrogen atoms + + + align:start position:0% +attraction when the two hydrogen atoms +here are very far + + align:start position:0% +here are very far + + + align:start position:0% +here are very far +apart what is the + + align:start position:0% +apart what is the + + + align:start position:0% +apart what is the +energy of the electron nuclear + + align:start position:0% +energy of the electron nuclear + + + align:start position:0% +energy of the electron nuclear +attraction + + align:start position:0% +attraction + + + align:start position:0% +attraction +there pardon I can't hear you so I'll + + align:start position:0% +there pardon I can't hear you so I'll + + + align:start position:0% +there pardon I can't hear you so I'll +tell you what it is is The Binding + + align:start position:0% +tell you what it is is The Binding + + + align:start position:0% +tell you what it is is The Binding +energy of a 1s electron right I mean + + align:start position:0% +energy of a 1s electron right I mean + + + align:start position:0% +energy of a 1s electron right I mean +that is the energy of + + align:start position:0% +that is the energy of + + + align:start position:0% +that is the energy of +interaction when R is very large when R + + align:start position:0% +interaction when R is very large when R + + + align:start position:0% +interaction when R is very large when R +is infinity the energy of + + align:start position:0% +is infinity the energy of + + + align:start position:0% +is infinity the energy of +interaction is just the 1 s binding + + align:start position:0% +interaction is just the 1 s binding + + + align:start position:0% +interaction is just the 1 s binding +energy of the electron to each of its + + align:start position:0% +energy of the electron to each of its + + + align:start position:0% +energy of the electron to each of its +nuclei right the energy of interaction + + align:start position:0% +nuclei right the energy of interaction + + + align:start position:0% +nuclei right the energy of interaction +the electron nuclear traction is just e + + align:start position:0% +the electron nuclear traction is just e + + + align:start position:0% +the electron nuclear traction is just e +sub One S for this one and E sub 1s for + + align:start position:0% +sub One S for this one and E sub 1s for + + + align:start position:0% +sub One S for this one and E sub 1s for +that one right that's in a hydrogen atom + + align:start position:0% +that one right that's in a hydrogen atom + + + align:start position:0% +that one right that's in a hydrogen atom +that's what it is it's the electron + + align:start position:0% +that's what it is it's the electron + + + align:start position:0% +that's what it is it's the electron +nuclear + + align:start position:0% +nuclear + + + align:start position:0% +nuclear +attraction and so right here this is + + align:start position:0% +attraction and so right here this is + + + align:start position:0% +attraction and so right here this is +um this is equal to 2 * e sub 1 s all + + align:start position:0% +um this is equal to 2 * e sub 1 s all + + + align:start position:0% +um this is equal to 2 * e sub 1 s all +right now you know + + align:start position:0% + + + + align:start position:0% + +okay you know that e sub 1s is equal to + + align:start position:0% +okay you know that e sub 1s is equal to + + + align:start position:0% +okay you know that e sub 1s is equal to +- 2.18 * 10-8 Jew but in kles per mole + + align:start position:0% +- 2.18 * 10-8 Jew but in kles per mole + + + align:start position:0% +- 2.18 * 10-8 Jew but in kles per mole +that's equal to- + + align:start position:0% +that's equal to- + + + align:start position:0% +that's equal to- +1,312 KJ per + + align:start position:0% +1,312 KJ per + + + align:start position:0% +1,312 KJ per +mole and if we have two of them as we do + + align:start position:0% +mole and if we have two of them as we do + + + align:start position:0% +mole and if we have two of them as we do +well 2 * e sub 1s isus 2 + + align:start position:0% +well 2 * e sub 1s isus 2 + + + align:start position:0% +well 2 * e sub 1s isus 2 +624 KJ per + + align:start position:0% +624 KJ per + + + align:start position:0% +624 KJ per +mole okay so I calculated what the + + align:start position:0% +mole okay so I calculated what the + + + align:start position:0% +mole okay so I calculated what the +electron interaction energy is at R is + + align:start position:0% +electron interaction energy is at R is + + + align:start position:0% +electron interaction energy is at R is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +Infinity so hey that's a way out + + align:start position:0% +Infinity so hey that's a way out + + + align:start position:0% +Infinity so hey that's a way out +here so this is hydrogen plus hydrogen + + align:start position:0% +here so this is hydrogen plus hydrogen + + + align:start position:0% +here so this is hydrogen plus hydrogen +this is - + + align:start position:0% +this is - + + + align:start position:0% +this is - +2,624 same number I got over + + align:start position:0% + + + + align:start position:0% + +there okay + + align:start position:0% +there okay + + + align:start position:0% +there okay +so now what we got to + + align:start position:0% + + + + align:start position:0% + +do all right so now what we got to do is + + align:start position:0% +do all right so now what we got to do is + + + align:start position:0% +do all right so now what we got to do is +we've got to calculate what that energy + + align:start position:0% +we've got to calculate what that energy + + + align:start position:0% +we've got to calculate what that energy +of interaction is at R is equal to + + align:start position:0% +of interaction is at R is equal to + + + align:start position:0% +of interaction is at R is equal to +zero well when R is equal to zero we + + align:start position:0% +zero well when R is equal to zero we + + + align:start position:0% +zero well when R is equal to zero we +have two hydrogen atoms right on top of + + align:start position:0% +have two hydrogen atoms right on top of + + + align:start position:0% +have two hydrogen atoms right on top of +each other right we've got two hydrogen + + align:start position:0% +each other right we've got two hydrogen + + + align:start position:0% +each other right we've got two hydrogen +nucle clei right on top of each + + align:start position:0% +nucle clei right on top of each + + + align:start position:0% +nucle clei right on top of each +other that means in our kind of thought + + align:start position:0% +other that means in our kind of thought + + + align:start position:0% +other that means in our kind of thought +experiment here that the charge on the + + align:start position:0% +experiment here that the charge on the + + + align:start position:0% +experiment here that the charge on the +nucleus is z equal 2 that means when the + + align:start position:0% +nucleus is z equal 2 that means when the + + + align:start position:0% +nucleus is z equal 2 that means when the +two hydrogen atoms are right on top of + + align:start position:0% +two hydrogen atoms are right on top of + + + align:start position:0% +two hydrogen atoms are right on top of +each other it looks like we've got a + + align:start position:0% +each other it looks like we've got a + + + align:start position:0% +each other it looks like we've got a +helium + + align:start position:0% +helium + + + align:start position:0% +helium +nucleus right and there's electron + + align:start position:0% +nucleus right and there's electron + + + align:start position:0% +nucleus right and there's electron +number one around it and electron number + + align:start position:0% +number one around it and electron number + + + align:start position:0% +number one around it and electron number +two around it hey that looks like a + + align:start position:0% +two around it hey that looks like a + + + align:start position:0% +two around it hey that looks like a +helium + + align:start position:0% +helium + + + align:start position:0% +helium +atom all right right so now what is the + + align:start position:0% +atom all right right so now what is the + + + align:start position:0% +atom all right right so now what is the +total electron interactions in the case + + align:start position:0% +total electron interactions in the case + + + align:start position:0% +total electron interactions in the case +of a helium atom what is the total + + align:start position:0% +of a helium atom what is the total + + + align:start position:0% +of a helium atom what is the total +energy of interaction + + align:start position:0% +energy of interaction + + + align:start position:0% +energy of interaction +there well the total energy of + + align:start position:0% +there well the total energy of + + + align:start position:0% +there well the total energy of +interaction is going to + + align:start position:0% +interaction is going to + + + align:start position:0% +interaction is going to +be minus the first ionization energy so + + align:start position:0% +be minus the first ionization energy so + + + align:start position:0% +be minus the first ionization energy so +this is going to be the energy of + + align:start position:0% +this is going to be the energy of + + + align:start position:0% +this is going to be the energy of +interaction of the helium it's going to + + align:start position:0% +interaction of the helium it's going to + + + align:start position:0% +interaction of the helium it's going to +be minus the first ionization energy for + + align:start position:0% +be minus the first ionization energy for + + + align:start position:0% +be minus the first ionization energy for +a helium atom + + align:start position:0% +a helium atom + + + align:start position:0% +a helium atom +because minus the first ionization + + align:start position:0% +because minus the first ionization + + + align:start position:0% +because minus the first ionization +energy of the helium atom is The Binding + + align:start position:0% +energy of the helium atom is The Binding + + + align:start position:0% +energy of the helium atom is The Binding +energy of the first electron to the + + align:start position:0% +energy of the first electron to the + + + align:start position:0% +energy of the first electron to the +helium + + align:start position:0% + + + + align:start position:0% + +right plus minus the second ionization + + align:start position:0% +right plus minus the second ionization + + + align:start position:0% +right plus minus the second ionization +energy of the helium atom so in other + + align:start position:0% +energy of the helium atom so in other + + + align:start position:0% +energy of the helium atom so in other +words if I have this one + + align:start position:0% +words if I have this one + + + align:start position:0% +words if I have this one +away then the then the electron nuclear + + align:start position:0% +away then the then the electron nuclear + + + align:start position:0% +away then the then the electron nuclear +attraction between the helium nucleus + + align:start position:0% +attraction between the helium nucleus + + + align:start position:0% +attraction between the helium nucleus +and electron 2 is just the minus the + + align:start position:0% +and electron 2 is just the minus the + + + align:start position:0% +and electron 2 is just the minus the +ionization energy the second ionization + + align:start position:0% +ionization energy the second ionization + + + align:start position:0% +ionization energy the second ionization +energy of helium all right does that + + align:start position:0% +energy of helium all right does that + + + align:start position:0% +energy of helium all right does that +make + + align:start position:0% + + + + align:start position:0% + +sense you're too hot to think + + align:start position:0% +sense you're too hot to think + + + align:start position:0% +sense you're too hot to think +right + + align:start position:0% +right + + + align:start position:0% +right +okay that's what that is and if you look + + align:start position:0% +okay that's what that is and if you look + + + align:start position:0% +okay that's what that is and if you look +them + + align:start position:0% +them + + + align:start position:0% +them +up the total energy of interaction there + + align:start position:0% +up the total energy of interaction there + + + align:start position:0% +up the total energy of interaction there +is minus 7,622 + + align:start position:0% +is minus 7,622 + + + align:start position:0% +is minus 7,622 +KJ per + + align:start position:0% +KJ per + + + align:start position:0% +KJ per +mole all + + align:start position:0% + + + + align:start position:0% + +right okay so hey I can plot that on + + align:start position:0% +right okay so hey I can plot that on + + + align:start position:0% +right okay so hey I can plot that on +this graph at R is equal to zero I got + + align:start position:0% +this graph at R is equal to zero I got + + + align:start position:0% +this graph at R is equal to zero I got +this - + + align:start position:0% +this - + + + align:start position:0% +this - +7,622 + + align:start position:0% +7,622 + + + align:start position:0% +7,622 +K so now I got two points I got a point + + align:start position:0% +K so now I got two points I got a point + + + align:start position:0% +K so now I got two points I got a point +over here and a point over there hey I'm + + align:start position:0% +over here and a point over there hey I'm + + + align:start position:0% +over here and a point over there hey I'm +going to draw a straight + + align:start position:0% +going to draw a straight + + + align:start position:0% +going to draw a straight +line between the two and now to get my + + align:start position:0% +line between the two and now to get my + + + align:start position:0% +line between the two and now to get my +total energy of interaction I'm going to + + align:start position:0% +total energy of interaction I'm going to + + + align:start position:0% +total energy of interaction I'm going to +add this curve to that + + align:start position:0% +add this curve to that + + + align:start position:0% +add this curve to that +curve and when I do + + align:start position:0% +curve and when I do + + + align:start position:0% +curve and when I do +that give me some uh artistic uh license + + align:start position:0% +that give me some uh artistic uh license + + + align:start position:0% +that give me some uh artistic uh license +here we're going to get something that + + align:start position:0% +here we're going to get something that + + + align:start position:0% +here we're going to get something that +looks like that + + align:start position:0% +looks like that + + + align:start position:0% +looks like that +okay the bottom line is that this shape + + align:start position:0% +okay the bottom line is that this shape + + + align:start position:0% +okay the bottom line is that this shape +here is determined by the + + align:start position:0% +here is determined by the + + + align:start position:0% +here is determined by the +competition between the electron + + align:start position:0% +competition between the electron + + + align:start position:0% +competition between the electron +interactions which are always attractive + + align:start position:0% +interactions which are always attractive + + + align:start position:0% +interactions which are always attractive +they're always negative the electron + + align:start position:0% +they're always negative the electron + + + align:start position:0% +they're always negative the electron +interactions are actually the sum of an + + align:start position:0% +interactions are actually the sum of an + + + align:start position:0% +interactions are actually the sum of an +attractive term and a repulsive term but + + align:start position:0% +attractive term and a repulsive term but + + + align:start position:0% +attractive term and a repulsive term but +the repulsive term Isn't So repulsive as + + align:start position:0% +the repulsive term Isn't So repulsive as + + + align:start position:0% +the repulsive term Isn't So repulsive as +to overcome the attractive term it's + + align:start position:0% +to overcome the attractive term it's + + + align:start position:0% +to overcome the attractive term it's +always negative so overall even the sum + + align:start position:0% +always negative so overall even the sum + + + align:start position:0% +always negative so overall even the sum +is still + + align:start position:0% +is still + + + align:start position:0% +is still +attractive all right so the electron + + align:start position:0% +attractive all right so the electron + + + align:start position:0% +attractive all right so the electron +interactions are + + align:start position:0% +interactions are + + + align:start position:0% +interactions are +attractive so this particular curve + + align:start position:0% +attractive so this particular curve + + + align:start position:0% +attractive so this particular curve +curve is a competition between the + + align:start position:0% +curve is a competition between the + + + align:start position:0% +curve is a competition between the +electron interactions those attractive + + align:start position:0% +electron interactions those attractive + + + align:start position:0% +electron interactions those attractive +interactions and the nuclear + + align:start position:0% +interactions and the nuclear + + + align:start position:0% +interactions and the nuclear +interactions which are + + align:start position:0% +interactions which are + + + align:start position:0% +interactions which are +repulsive in other words you have to get + + align:start position:0% +repulsive in other words you have to get + + + align:start position:0% +repulsive in other words you have to get +the two hydrogen atoms close + + align:start position:0% +the two hydrogen atoms close + + + align:start position:0% +the two hydrogen atoms close +enough in order for the attractive + + align:start position:0% +enough in order for the attractive + + + align:start position:0% +enough in order for the attractive +interactions to take hold but you can't + + align:start position:0% +interactions to take hold but you can't + + + align:start position:0% +interactions to take hold but you can't +get them so close because if you get + + align:start position:0% +get them so close because if you get + + + align:start position:0% +get them so close because if you get +them too close the nuclear nuclear + + align:start position:0% +them too close the nuclear nuclear + + + align:start position:0% +them too close the nuclear nuclear +repulsions set + + align:start position:0% +repulsions set + + + align:start position:0% +repulsions set +in so where your chemical bond length is + + align:start position:0% +in so where your chemical bond length is + + + align:start position:0% +in so where your chemical bond length is +is determined by that competition + + align:start position:0% +is determined by that competition + + + align:start position:0% +is determined by that competition +between the electron attractive + + align:start position:0% +between the electron attractive + + + align:start position:0% +between the electron attractive +interactions and those nuclear nuclear + + align:start position:0% +interactions and those nuclear nuclear + + + align:start position:0% +interactions and those nuclear nuclear +repulsions all right that's what + + align:start position:0% +repulsions all right that's what + + + align:start position:0% +repulsions all right that's what +determines the bond + + align:start position:0% +determines the bond + + + align:start position:0% +determines the bond +length that is fundamentally here what + + align:start position:0% +length that is fundamentally here what + + + align:start position:0% +length that is fundamentally here what +determines the bond strength is the + + align:start position:0% +determines the bond strength is the + + + align:start position:0% +determines the bond strength is the +competition between these overall + + align:start position:0% +competition between these overall + + + align:start position:0% +competition between these overall +attractive interactions due to the + + align:start position:0% +attractive interactions due to the + + + align:start position:0% +attractive interactions due to the +electrons and the nuclear nuclear + + align:start position:0% +electrons and the nuclear nuclear + + + align:start position:0% +electrons and the nuclear nuclear +repulsion all + + align:start position:0% +repulsion all + + + align:start position:0% +repulsion all +right okay so that was the concept + + align:start position:0% +right okay so that was the concept + + + align:start position:0% +right okay so that was the concept +really that I wanted to get across here + + align:start position:0% +really that I wanted to get across here + + + align:start position:0% +really that I wanted to get across here +was those fundamental interactions that + + align:start position:0% +was those fundamental interactions that + + + align:start position:0% +was those fundamental interactions that +make up this kind of curve you're going + + align:start position:0% +make up this kind of curve you're going + + + align:start position:0% +make up this kind of curve you're going +to see this curve a lot All chemical + + align:start position:0% +to see this curve a lot All chemical + + + align:start position:0% +to see this curve a lot All chemical +bonds have this kind of dependence on + + align:start position:0% +bonds have this kind of dependence on + + + align:start position:0% +bonds have this kind of dependence on +our energy of interaction on + + align:start position:0% +our energy of interaction on + + + align:start position:0% +our energy of interaction on +R now there's one other point I want to + + align:start position:0% +R now there's one other point I want to + + + align:start position:0% +R now there's one other point I want to +make and that + + align:start position:0% +make and that + + + align:start position:0% +make and that +is that what we often and usually + + align:start position:0% +is that what we often and usually + + + align:start position:0% +is that what we often and usually +do is we reset our zero of + + align:start position:0% +do is we reset our zero of + + + align:start position:0% +do is we reset our zero of +energy in other words we're going to + + align:start position:0% +energy in other words we're going to + + + align:start position:0% +energy in other words we're going to +reset our zero of energy here so that + + align:start position:0% +reset our zero of energy here so that + + + align:start position:0% +reset our zero of energy here so that +the zero of energy corresponds to the SE + + align:start position:0% +the zero of energy corresponds to the SE + + + align:start position:0% +the zero of energy corresponds to the SE +separated atom + + align:start position:0% +separated atom + + + align:start position:0% +separated atom +limit why do we do that well we do that + + align:start position:0% +limit why do we do that well we do that + + + align:start position:0% +limit why do we do that well we do that +because this energy difference Theus + + align:start position:0% +because this energy difference Theus + + + align:start position:0% +because this energy difference Theus +2,624 well that energy difference was + + align:start position:0% +2,624 well that energy difference was + + + align:start position:0% +2,624 well that energy difference was +really the attractive interaction + + align:start position:0% +really the attractive interaction + + + align:start position:0% +really the attractive interaction +between the electron and its nucleus it + + align:start position:0% +between the electron and its nucleus it + + + align:start position:0% +between the electron and its nucleus it +didn't have anything to do with the + + align:start position:0% +didn't have anything to do with the + + + align:start position:0% +didn't have anything to do with the +attraction or repulsion between the two + + align:start position:0% +attraction or repulsion between the two + + + align:start position:0% +attraction or repulsion between the two +atoms and so when we want to talk only + + align:start position:0% +atoms and so when we want to talk only + + + align:start position:0% +atoms and so when we want to talk only +about the chemical bond and the energy + + align:start position:0% +about the chemical bond and the energy + + + align:start position:0% +about the chemical bond and the energy +changes when we make a chemical bond + + align:start position:0% +changes when we make a chemical bond + + + align:start position:0% +changes when we make a chemical bond +it's often useful to shift our zero of + + align:start position:0% +it's often useful to shift our zero of + + + align:start position:0% +it's often useful to shift our zero of +energy down so that the separated atom + + align:start position:0% +energy down so that the separated atom + + + align:start position:0% +energy down so that the separated atom +limit is our zero of + + align:start position:0% +limit is our zero of + + + align:start position:0% +limit is our zero of +energy and now everything that is + + align:start position:0% +energy and now everything that is + + + align:start position:0% +energy and now everything that is +negative relative to that is a bound + + align:start position:0% +negative relative to that is a bound + + + align:start position:0% +negative relative to that is a bound +interaction when it gets too close it'll + + align:start position:0% +interaction when it gets too close it'll + + + align:start position:0% +interaction when it gets too close it'll +be a positive interaction and the H then + + align:start position:0% +be a positive interaction and the H then + + + align:start position:0% +be a positive interaction and the H then +the atoms are no longer + + align:start position:0% +the atoms are no longer + + + align:start position:0% +the atoms are no longer +bound okay I mean we're not forgetting + + align:start position:0% +bound okay I mean we're not forgetting + + + align:start position:0% +bound okay I mean we're not forgetting +about this energy here we know if you're + + align:start position:0% +about this energy here we know if you're + + + align:start position:0% +about this energy here we know if you're +calculating the total energy it's got to + + align:start position:0% +calculating the total energy it's got to + + + align:start position:0% +calculating the total energy it's got to +be there but often times we just want to + + align:start position:0% +be there but often times we just want to + + + align:start position:0% +be there but often times we just want to +talk about the relative changes of the + + align:start position:0% +talk about the relative changes of the + + + align:start position:0% +talk about the relative changes of the +energy of interaction as a function of r + + align:start position:0% +energy of interaction as a function of r + + + align:start position:0% +energy of interaction as a function of r +when when we're concerned only with + + align:start position:0% +when when we're concerned only with + + + align:start position:0% +when when we're concerned only with +forming a + + align:start position:0% +forming a + + + align:start position:0% +forming a +bond + + align:start position:0% +bond + + + align:start position:0% +bond +okay make + + align:start position:0% +okay make + + + align:start position:0% +okay make +sense + + align:start position:0% +sense + + + align:start position:0% +sense +okay all right all + + align:start position:0% +okay all right all + + + align:start position:0% +okay all right all +right so that's the general phenomenon + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +now okay I'm going to take your ear for + + align:start position:0% +now okay I'm going to take your ear for + + + align:start position:0% +now okay I'm going to take your ear for +a + + align:start position:0% + + + + align:start position:0% + +moment okay so now + + align:start position:0% +moment okay so now + + + align:start position:0% +moment okay so now +um what I want to talk + + align:start position:0% +um what I want to talk + + + align:start position:0% +um what I want to talk +about is one very simple model for an + + align:start position:0% +about is one very simple model for an + + + align:start position:0% +about is one very simple model for an +ionic + + align:start position:0% +ionic + + + align:start position:0% +ionic +bond this is a classical + + align:start position:0% +bond this is a classical + + + align:start position:0% +bond this is a classical +model and the amazing thing about it is + + align:start position:0% +model and the amazing thing about it is + + + align:start position:0% +model and the amazing thing about it is +that this simple classical model does + + align:start position:0% +that this simple classical model does + + + align:start position:0% +that this simple classical model does +give + + align:start position:0% +give + + + align:start position:0% +give +us insight into the mechanism by which + + align:start position:0% +us insight into the mechanism by which + + + align:start position:0% +us insight into the mechanism by which +this uh bond is + + align:start position:0% + + + + align:start position:0% + +formed it is a mechanism that's only + + align:start position:0% +formed it is a mechanism that's only + + + align:start position:0% +formed it is a mechanism that's only +going to work when you form a very ionic + + align:start position:0% +going to work when you form a very ionic + + + align:start position:0% +going to work when you form a very ionic +bond all right so this is particular for + + align:start position:0% +bond all right so this is particular for + + + align:start position:0% +bond all right so this is particular for +a very ionic bond and we want to take a + + align:start position:0% +a very ionic bond and we want to take a + + + align:start position:0% +a very ionic bond and we want to take a +look at this mechanism because it's + + align:start position:0% +look at this mechanism because it's + + + align:start position:0% +look at this mechanism because it's +going to give us some + + align:start position:0% +going to give us some + + + align:start position:0% +going to give us some +insight into how + + align:start position:0% +insight into how + + + align:start position:0% +insight into how +the bond is actually + + align:start position:0% +the bond is actually + + + align:start position:0% +the bond is actually +formed + + align:start position:0% + + + + align:start position:0% + +okay so we're going to look at the + + align:start position:0% +okay so we're going to look at the + + + align:start position:0% +okay so we're going to look at the +formation of uh sodium chloride here + + align:start position:0% +formation of uh sodium chloride here + + + align:start position:0% +formation of uh sodium chloride here +so we have a sodium atom and a chlorine + + align:start position:0% +so we have a sodium atom and a chlorine + + + align:start position:0% +so we have a sodium atom and a chlorine +atom and they're coming together they're + + align:start position:0% +atom and they're coming together they're + + + align:start position:0% +atom and they're coming together they're +moving toward each + + align:start position:0% +moving toward each + + + align:start position:0% +moving toward each +other well what happens is that at a + + align:start position:0% +other well what happens is that at a + + + align:start position:0% +other well what happens is that at a +certain distance from each other the + + align:start position:0% +certain distance from each other the + + + align:start position:0% +certain distance from each other the +sodium atom believe it or not actually + + align:start position:0% +sodium atom believe it or not actually + + + align:start position:0% +sodium atom believe it or not actually +ejects an + + align:start position:0% +ejects an + + + align:start position:0% +ejects an +electron and that electron hooks on to + + align:start position:0% +electron and that electron hooks on to + + + align:start position:0% +electron and that electron hooks on to +the + + align:start position:0% +the + + + align:start position:0% +the +chlorine and when it does that + + align:start position:0% +chlorine and when it does that + + + align:start position:0% +chlorine and when it does that +well then of course the chlorine now + + align:start position:0% +well then of course the chlorine now + + + align:start position:0% +well then of course the chlorine now +becomes bigger than the + + align:start position:0% +becomes bigger than the + + + align:start position:0% +becomes bigger than the +sodium but now we've got two charges + + align:start position:0% +sodium but now we've got two charges + + + align:start position:0% +sodium but now we've got two charges +separated an two a positive and a + + align:start position:0% +separated an two a positive and a + + + align:start position:0% +separated an two a positive and a +negative ion and hey there's a large + + align:start position:0% +negative ion and hey there's a large + + + align:start position:0% +negative ion and hey there's a large +attractive interaction between those two + + align:start position:0% +attractive interaction between those two + + + align:start position:0% +attractive interaction between those two +so what happens is that these two ions + + align:start position:0% +so what happens is that these two ions + + + align:start position:0% +so what happens is that these two ions +are attracted into each other they're + + align:start position:0% +are attracted into each other they're + + + align:start position:0% +are attracted into each other they're +just roped right in all right it's + + align:start position:0% +just roped right in all right it's + + + align:start position:0% +just roped right in all right it's +called the Harpoon mechanism + + align:start position:0% +called the Harpoon mechanism + + + align:start position:0% +called the Harpoon mechanism +why is that why does the sodium and the + + align:start position:0% +why is that why does the sodium and the + + + align:start position:0% +why is that why does the sodium and the +chlorine just pull right into each other + + align:start position:0% +chlorine just pull right into each other + + + align:start position:0% +chlorine just pull right into each other +well because of that + + align:start position:0% +well because of that + + + align:start position:0% +well because of that +rope that rope is that Kum + + align:start position:0% +rope that rope is that Kum + + + align:start position:0% +rope that rope is that Kum +interaction + + align:start position:0% +interaction + + + align:start position:0% +interaction +okay so this really happens at some + + align:start position:0% +okay so this really happens at some + + + align:start position:0% +okay so this really happens at some +distance the sodium atom ejects that + + align:start position:0% +distance the sodium atom ejects that + + + align:start position:0% +distance the sodium atom ejects that +electron and then that sodium just pulls + + align:start position:0% +electron and then that sodium just pulls + + + align:start position:0% +electron and then that sodium just pulls +that chlorine right into it till it gets + + align:start position:0% +that chlorine right into it till it gets + + + align:start position:0% +that chlorine right into it till it gets +close enough to form a chemical bond and + + align:start position:0% +close enough to form a chemical bond and + + + align:start position:0% +close enough to form a chemical bond and +you've got sodium + + align:start position:0% +you've got sodium + + + align:start position:0% +you've got sodium +chloride this is a reaction + + align:start position:0% +chloride this is a reaction + + + align:start position:0% +chloride this is a reaction +mechanism that was uh + + align:start position:0% +mechanism that was uh + + + align:start position:0% +mechanism that was uh +elucidated many years + + align:start position:0% +elucidated many years + + + align:start position:0% +elucidated many years +ago called the Harpoon mechanism it is + + align:start position:0% +ago called the Harpoon mechanism it is + + + align:start position:0% +ago called the Harpoon mechanism it is +um a mechanism elucidated by Dudley + + align:start position:0% +um a mechanism elucidated by Dudley + + + align:start position:0% +um a mechanism elucidated by Dudley +hersbach who's here at Harvard in + + align:start position:0% +hersbach who's here at Harvard in + + + align:start position:0% +hersbach who's here at Harvard in +chemistry Department who has since + + align:start position:0% +chemistry Department who has since + + + align:start position:0% +chemistry Department who has since +retired John Palani who's at Toronto + + align:start position:0% +retired John Palani who's at Toronto + + + align:start position:0% +retired John Palani who's at Toronto +Yuan Lee who was at a Berkeley for most + + align:start position:0% +Yuan Lee who was at a Berkeley for most + + + align:start position:0% +Yuan Lee who was at a Berkeley for most +of his + + align:start position:0% +of his + + + align:start position:0% +of his +career um they received a Nobel Prize + + align:start position:0% +career um they received a Nobel Prize + + + align:start position:0% +career um they received a Nobel Prize +for this discovery of this mechanism and + + align:start position:0% +for this discovery of this mechanism and + + + align:start position:0% +for this discovery of this mechanism and +many other kinds of mechanism and + + align:start position:0% +many other kinds of mechanism and + + + align:start position:0% +many other kinds of mechanism and +dynamics of the Rea of chemical + + align:start position:0% +dynamics of the Rea of chemical + + + align:start position:0% +dynamics of the Rea of chemical +reactions uh youan lee right here this + + align:start position:0% +reactions uh youan lee right here this + + + align:start position:0% +reactions uh youan lee right here this +gentleman uh was actually my PhD thesis + + align:start position:0% +gentleman uh was actually my PhD thesis + + + align:start position:0% +gentleman uh was actually my PhD thesis +supervisor at + + align:start position:0% +supervisor at + + + align:start position:0% +supervisor at +Berkeley um and so + + align:start position:0% +Berkeley um and so + + + align:start position:0% +Berkeley um and so +uh um + + align:start position:0% + + + + align:start position:0% + +so this is a simple picture and this is + + align:start position:0% +so this is a simple picture and this is + + + align:start position:0% +so this is a simple picture and this is +exactly what's going on now this seems a + + align:start position:0% +exactly what's going on now this seems a + + + align:start position:0% +exactly what's going on now this seems a +little strange to you right so let's try + + align:start position:0% +little strange to you right so let's try + + + align:start position:0% +little strange to you right so let's try +to understand uh exactly how this is + + align:start position:0% +to understand uh exactly how this is + + + align:start position:0% +to understand uh exactly how this is +working all + + align:start position:0% +working all + + + align:start position:0% +working all +right okay well to understand this what + + align:start position:0% +right okay well to understand this what + + + align:start position:0% +right okay well to understand this what +we're going to have to do is to look at + + align:start position:0% +we're going to have to do is to look at + + + align:start position:0% +we're going to have to do is to look at +the energetics uh of the + + align:start position:0% +the energetics uh of the + + + align:start position:0% +the energetics uh of the +system and now I'm going to erase the + + align:start position:0% +system and now I'm going to erase the + + + align:start position:0% +system and now I'm going to erase the +screen here I think no I don't want to + + align:start position:0% +screen here I think no I don't want to + + + align:start position:0% +screen here I think no I don't want to +I'm going to raise it a little bit how's + + align:start position:0% + + + + align:start position:0% + +that okay + + align:start position:0% +that okay + + + align:start position:0% +that okay +[Music] + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so what we're seeing is this gas phase + + align:start position:0% +so what we're seeing is this gas phase + + + align:start position:0% +so what we're seeing is this gas phase +sodium atom is ejecting an electron to + + align:start position:0% +sodium atom is ejecting an electron to + + + align:start position:0% +sodium atom is ejecting an electron to +form this gas phase sodium ion plus this + + align:start position:0% +form this gas phase sodium ion plus this + + + align:start position:0% +form this gas phase sodium ion plus this +electron and of course that's going to + + align:start position:0% +electron and of course that's going to + + + align:start position:0% +electron and of course that's going to +cost energy the energy change is the + + align:start position:0% +cost energy the energy change is the + + + align:start position:0% +cost energy the energy change is the +ionization energy which is for sodium + + align:start position:0% +ionization energy which is for sodium + + + align:start position:0% +ionization energy which is for sodium +496 K per + + align:start position:0% +496 K per + + + align:start position:0% +496 K per +mole right + + align:start position:0% +mole right + + + align:start position:0% +mole right +but at the same time that electron is + + align:start position:0% +but at the same time that electron is + + + align:start position:0% +but at the same time that electron is +being caught by the + + align:start position:0% +being caught by the + + + align:start position:0% +being caught by the +chlorine and + + align:start position:0% +chlorine and + + + align:start position:0% +chlorine and +when a chlorine and an electron Rec + + align:start position:0% +when a chlorine and an electron Rec + + + align:start position:0% +when a chlorine and an electron Rec +combine to form the CL minus gas phase + + align:start position:0% +combine to form the CL minus gas phase + + + align:start position:0% +combine to form the CL minus gas phase +there's an energy release we as we saw + + align:start position:0% +there's an energy release we as we saw + + + align:start position:0% +there's an energy release we as we saw +that energy release is minus the + + align:start position:0% +that energy release is minus the + + + align:start position:0% +that energy release is minus the +electron affinity of + + align:start position:0% +electron affinity of + + + align:start position:0% +electron affinity of +chlorine that's equal to minus + + align:start position:0% +chlorine that's equal to minus + + + align:start position:0% +chlorine that's equal to minus +349 KJ per mole + + align:start position:0% +349 KJ per mole + + + align:start position:0% +349 KJ per mole +all right so + + align:start position:0% +all right so + + + align:start position:0% +all right so +overall you know going from a gas phase + + align:start position:0% +overall you know going from a gas phase + + + align:start position:0% +overall you know going from a gas phase +sodium atom plus a gasphase chlorine + + align:start position:0% +sodium atom plus a gasphase chlorine + + + align:start position:0% +sodium atom plus a gasphase chlorine +atom to a gasphase sodium ion and a + + align:start position:0% +atom to a gasphase sodium ion and a + + + align:start position:0% +atom to a gasphase sodium ion and a +gasphase chlorine ion the overall energy + + align:start position:0% +gasphase chlorine ion the overall energy + + + align:start position:0% +gasphase chlorine ion the overall energy +change here which is now the ionization + + align:start position:0% +change here which is now the ionization + + + align:start position:0% +change here which is now the ionization +energy minus the electron + + align:start position:0% +energy minus the electron + + + align:start position:0% +energy minus the electron +affinity that overall energy change is + + align:start position:0% +affinity that overall energy change is + + + align:start position:0% +affinity that overall energy change is +47 KJ per + + align:start position:0% +47 KJ per + + + align:start position:0% +47 KJ per +mole okay so although we get some energy + + align:start position:0% +mole okay so although we get some energy + + + align:start position:0% +mole okay so although we get some energy +back when that electron attaches to the + + align:start position:0% +back when that electron attaches to the + + + align:start position:0% +back when that electron attaches to the +chlorine we don't get enough energy back + + align:start position:0% +chlorine we don't get enough energy back + + + align:start position:0% +chlorine we don't get enough energy back +to compensate for having to pull the + + align:start position:0% +to compensate for having to pull the + + + align:start position:0% +to compensate for having to pull the +electron off of the + + align:start position:0% +electron off of the + + + align:start position:0% +electron off of the +sodium so right now this still looks + + align:start position:0% +sodium so right now this still looks + + + align:start position:0% +sodium so right now this still looks +like an + + align:start position:0% +like an + + + align:start position:0% +like an +overall endothermic reaction we got to + + align:start position:0% +overall endothermic reaction we got to + + + align:start position:0% +overall endothermic reaction we got to +put 147 kles into the system to make it + + align:start position:0% +put 147 kles into the system to make it + + + align:start position:0% +put 147 kles into the system to make it +go + + align:start position:0% +go + + + align:start position:0% +go +so it's beginning to seem a little + + align:start position:0% +so it's beginning to seem a little + + + align:start position:0% +so it's beginning to seem a little +peculiar how does this + + align:start position:0% + + + + align:start position:0% + +work well we have to + + align:start position:0% +work well we have to + + + align:start position:0% +work well we have to +remember that + + align:start position:0% +remember that + + + align:start position:0% +remember that +um okay all right thanks we have to + + align:start position:0% +um okay all right thanks we have to + + + align:start position:0% +um okay all right thanks we have to +remember now that once we make that + + align:start position:0% +remember now that once we make that + + + align:start position:0% +remember now that once we make that +sodium plus and the chlorine + + align:start position:0% +sodium plus and the chlorine + + + align:start position:0% +sodium plus and the chlorine +minus that there's that kulum + + align:start position:0% +minus that there's that kulum + + + align:start position:0% +minus that there's that kulum +interaction right the Kum interaction + + align:start position:0% +interaction right the Kum interaction + + + align:start position:0% +interaction right the Kum interaction +bringing the sodium ion plus the + + align:start position:0% +bringing the sodium ion plus the + + + align:start position:0% +bringing the sodium ion plus the +chlorine ion together to make the sodium + + align:start position:0% + + + + align:start position:0% + +chloride that Delta e that energy change + + align:start position:0% +chloride that Delta e that energy change + + + align:start position:0% +chloride that Delta e that energy change +if I take two ions sodium and chlorine + + align:start position:0% +if I take two ions sodium and chlorine + + + align:start position:0% +if I take two ions sodium and chlorine +in from infinity and bring them together + + align:start position:0% +in from infinity and bring them together + + + align:start position:0% +in from infinity and bring them together +at the bond length that energy change is + + align:start position:0% +at the bond length that energy change is + + + align:start position:0% +at the bond length that energy change is +minus + + align:start position:0% +minus + + + align:start position:0% +minus +592 K per + + align:start position:0% +592 K per + + + align:start position:0% +592 K per +mole so if I add up all three + + align:start position:0% +mole so if I add up all three + + + align:start position:0% +mole so if I add up all three +reactions to get sodium + + align:start position:0% +reactions to get sodium + + + align:start position:0% +reactions to get sodium +gas plus chlorine gas to make sodium + + align:start position:0% +gas plus chlorine gas to make sodium + + + align:start position:0% +gas plus chlorine gas to make sodium +chloride in the gas phase the overall + + align:start position:0% +chloride in the gas phase the overall + + + align:start position:0% +chloride in the gas phase the overall +energy change there is minus + + align:start position:0% +energy change there is minus + + + align:start position:0% +energy change there is minus +445 K per + + align:start position:0% +445 K per + + + align:start position:0% +445 K per +mole and of course the reaction is + + align:start position:0% +mole and of course the reaction is + + + align:start position:0% +mole and of course the reaction is +downhill all right but that still + + align:start position:0% +downhill all right but that still + + + align:start position:0% +downhill all right but that still +doesn't give you a really good feeling + + align:start position:0% +doesn't give you a really good feeling + + + align:start position:0% +doesn't give you a really good feeling +for what's really going on here so to do + + align:start position:0% +for what's really going on here so to do + + + align:start position:0% +for what's really going on here so to do +that let's look at it an energy level + + align:start position:0% + + + + align:start position:0% + +diagram okay so + + align:start position:0% +diagram okay so + + + align:start position:0% +diagram okay so +um want to kill the front light so this + + align:start position:0% +um want to kill the front light so this + + + align:start position:0% +um want to kill the front light so this +is going to be back and forth here all + + align:start position:0% +is going to be back and forth here all + + + align:start position:0% +is going to be back and forth here all +right so what have I drawn here I've + + align:start position:0% +right so what have I drawn here I've + + + align:start position:0% +right so what have I drawn here I've +drawn here the energy of interaction + + align:start position:0% +drawn here the energy of interaction + + + align:start position:0% +drawn here the energy of interaction +between a sodium atom and a chlorine + + align:start position:0% +between a sodium atom and a chlorine + + + align:start position:0% +between a sodium atom and a chlorine +atom just like I did for + + align:start position:0% +atom just like I did for + + + align:start position:0% +atom just like I did for +hydrogen I said all chemical bonds have + + align:start position:0% +hydrogen I said all chemical bonds have + + + align:start position:0% +hydrogen I said all chemical bonds have +this same energy of shape of energy of + + align:start position:0% +this same energy of shape of energy of + + + align:start position:0% +this same energy of shape of energy of +interaction here here's the bond + + align:start position:0% +interaction here here's the bond + + + align:start position:0% +interaction here here's the bond +length right 2.36 angstroms here's the + + align:start position:0% +length right 2.36 angstroms here's the + + + align:start position:0% +length right 2.36 angstroms here's the +well depth or the dissociation energy in + + align:start position:0% +well depth or the dissociation energy in + + + align:start position:0% +well depth or the dissociation energy in +this case I show it measured from here + + align:start position:0% +this case I show it measured from here + + + align:start position:0% +this case I show it measured from here +to there so it's minus E Delta e subd + + align:start position:0% +to there so it's minus E Delta e subd + + + align:start position:0% +to there so it's minus E Delta e subd +minus + + align:start position:0% +minus + + + align:start position:0% +minus +445 here I set the zero of energy at the + + align:start position:0% +445 here I set the zero of energy at the + + + align:start position:0% +445 here I set the zero of energy at the +separated atom limit sodium plus + + align:start position:0% +separated atom limit sodium plus + + + align:start position:0% +separated atom limit sodium plus +chlorine + + align:start position:0% +chlorine + + + align:start position:0% +chlorine +okay all right + + align:start position:0% +okay all right + + + align:start position:0% +okay all right +now when sodium and chloride are way out + + align:start position:0% +now when sodium and chloride are way out + + + align:start position:0% +now when sodium and chloride are way out +here when R is really + + align:start position:0% +here when R is really + + + align:start position:0% +here when R is really +large we saw that it's going to take 147 + + align:start position:0% +large we saw that it's going to take 147 + + + align:start position:0% +large we saw that it's going to take 147 +K to make a sodium ion from sodium and a + + align:start position:0% +K to make a sodium ion from sodium and a + + + align:start position:0% +K to make a sodium ion from sodium and a +chlorine ion from chlorine right that's + + align:start position:0% +chlorine ion from chlorine right that's + + + align:start position:0% +chlorine ion from chlorine right that's +what I calculated right here if the two + + align:start position:0% +what I calculated right here if the two + + + align:start position:0% +what I calculated right here if the two +are far apart if you pull an electron + + align:start position:0% +are far apart if you pull an electron + + + align:start position:0% +are far apart if you pull an electron +off of sodium and put it onto chlorine + + align:start position:0% +off of sodium and put it onto chlorine + + + align:start position:0% +off of sodium and put it onto chlorine +it's still going to require + + align:start position:0% +it's still going to require + + + align:start position:0% +it's still going to require +energy 147 kles per + + align:start position:0% + + + + align:start position:0% + +mole + + align:start position:0% +mole + + + align:start position:0% +mole +however I also said that when the sodium + + align:start position:0% +however I also said that when the sodium + + + align:start position:0% +however I also said that when the sodium +and the chlorine come close enough the + + align:start position:0% +and the chlorine come close enough the + + + align:start position:0% +and the chlorine come close enough the +ions are pulled in close + + align:start position:0% +ions are pulled in close + + + align:start position:0% +ions are pulled in close +enough such that they can form a + + align:start position:0% +enough such that they can form a + + + align:start position:0% +enough such that they can form a +chemical + + align:start position:0% +chemical + + + align:start position:0% +chemical +bond the energy you get back is + + align:start position:0% +bond the energy you get back is + + + align:start position:0% +bond the energy you get back is +592 K per mole on this diagram where is + + align:start position:0% +592 K per mole on this diagram where is + + + align:start position:0% +592 K per mole on this diagram where is +that well that that's this + + align:start position:0% +that well that that's this + + + align:start position:0% +that well that that's this +energy right from up here to down there + + align:start position:0% +energy right from up here to down there + + + align:start position:0% +energy right from up here to down there +that's 592 kilj per + + align:start position:0% + + + + align:start position:0% + +mole where did I get that number + + align:start position:0% +mole where did I get that number + + + align:start position:0% +mole where did I get that number +592 K per mole well I calculated + + align:start position:0% +592 K per mole well I calculated + + + align:start position:0% +592 K per mole well I calculated +it I calculated it using the coolum + + align:start position:0% +it I calculated it using the coolum + + + align:start position:0% +it I calculated it using the coolum +potential energy of interaction which + + align:start position:0% +potential energy of interaction which + + + align:start position:0% +potential energy of interaction which +I'm calling here U of our sub at this + + align:start position:0% +I'm calling here U of our sub at this + + + align:start position:0% +I'm calling here U of our sub at this +value of R the coolum potential energy + + align:start position:0% +value of R the coolum potential energy + + + align:start position:0% +value of R the coolum potential energy +of interaction here it is right here + + align:start position:0% +of interaction here it is right here + + + align:start position:0% +of interaction here it is right here +right for a point charge if you treat + + align:start position:0% +right for a point charge if you treat + + + align:start position:0% +right for a point charge if you treat +the sodium as a plus one charge and you + + align:start position:0% +the sodium as a plus one charge and you + + + align:start position:0% +the sodium as a plus one charge and you +treat the chlorine as a minus one charge + + align:start position:0% +treat the chlorine as a minus one charge + + + align:start position:0% +treat the chlorine as a minus one charge +so all of a sudden we're forgetting + + align:start position:0% +so all of a sudden we're forgetting + + + align:start position:0% +so all of a sudden we're forgetting +everything about the other electrons + + align:start position:0% +everything about the other electrons + + + align:start position:0% +everything about the other electrons +we're just treating sodium ion and + + align:start position:0% +we're just treating sodium ion and + + + align:start position:0% +we're just treating sodium ion and +chlorine ion as two point charges + + align:start position:0% +chlorine ion as two point charges + + + align:start position:0% +chlorine ion as two point charges +if you forget completely about the other + + align:start position:0% +if you forget completely about the other + + + align:start position:0% +if you forget completely about the other +electrons and just treat them as point + + align:start position:0% +electrons and just treat them as point + + + align:start position:0% +electrons and just treat them as point +charges that's the interaction energy + + align:start position:0% +charges that's the interaction energy + + + align:start position:0% +charges that's the interaction energy +right here and that + + align:start position:0% +right here and that + + + align:start position:0% +right here and that +592 comes from taking that + + align:start position:0% +592 comes from taking that + + + align:start position:0% +592 comes from taking that +expression and plugging in 2.36 + + align:start position:0% +expression and plugging in 2.36 + + + align:start position:0% +expression and plugging in 2.36 +angstroms all right so that's how much + + align:start position:0% +angstroms all right so that's how much + + + align:start position:0% +angstroms all right so that's how much +energy you get + + align:start position:0% + + + + align:start position:0% + +back okay so now we understand the + + align:start position:0% +back okay so now we understand the + + + align:start position:0% +back okay so now we understand the +energies a little a little bit but we + + align:start position:0% +energies a little a little bit but we + + + align:start position:0% +energies a little a little bit but we +still don't understand exactly how this + + align:start position:0% +still don't understand exactly how this + + + align:start position:0% +still don't understand exactly how this +electron jump process is happening right + + align:start position:0% +electron jump process is happening right + + + align:start position:0% +electron jump process is happening right +because the way I've got it drawn here + + align:start position:0% +because the way I've got it drawn here + + + align:start position:0% +because the way I've got it drawn here +it still looks like we are we have an + + align:start position:0% +it still looks like we are we have an + + + align:start position:0% +it still looks like we are we have an +electron jumping from sodium to chlorine + + align:start position:0% +electron jumping from sodium to chlorine + + + align:start position:0% +electron jumping from sodium to chlorine +way out here and we have to put in 147 + + align:start position:0% +way out here and we have to put in 147 + + + align:start position:0% +way out here and we have to put in 147 +kles before we get any energy + + align:start position:0% +kles before we get any energy + + + align:start position:0% +kles before we get any energy +back well that's not the + + align:start position:0% +back well that's not the + + + align:start position:0% +back well that's not the +case and that's not the case because of + + align:start position:0% +case and that's not the case because of + + + align:start position:0% +case and that's not the case because of +this this blue curve here this blue + + align:start position:0% +this this blue curve here this blue + + + align:start position:0% +this this blue curve here this blue +curve is just the coolum energy of + + align:start position:0% +curve is just the coolum energy of + + + align:start position:0% +curve is just the coolum energy of +interaction we + + align:start position:0% +interaction we + + + align:start position:0% +interaction we +evaluated that point that number from + + align:start position:0% +evaluated that point that number from + + + align:start position:0% +evaluated that point that number from +here to here using this + + align:start position:0% +here to here using this + + + align:start position:0% +here to here using this +expression but you know that this is a + + align:start position:0% +expression but you know that this is a + + + align:start position:0% +expression but you know that this is a +one over a minus one over our + + align:start position:0% +one over a minus one over our + + + align:start position:0% +one over a minus one over our +dependence so if you're way up here and + + align:start position:0% +dependence so if you're way up here and + + + align:start position:0% +dependence so if you're way up here and +you treat this as a zero of energy for + + align:start position:0% +you treat this as a zero of energy for + + + align:start position:0% +you treat this as a zero of energy for +two separated a plus charge and a minus + + align:start position:0% +two separated a plus charge and a minus + + + align:start position:0% +two separated a plus charge and a minus +charge 1 / R kind of looks like this + + align:start position:0% +charge 1 / R kind of looks like this + + + align:start position:0% +charge 1 / R kind of looks like this +that's the blue + + align:start position:0% +that's the blue + + + align:start position:0% +that's the blue +curve + + align:start position:0% + + + + align:start position:0% + +okay all right but you also notice that + + align:start position:0% +okay all right but you also notice that + + + align:start position:0% +okay all right but you also notice that +right in here right + + align:start position:0% +right in here right + + + align:start position:0% +right in here right +here you see that that kulum + + align:start position:0% +here you see that that kulum + + + align:start position:0% +here you see that that kulum +interaction is intersecting with this + + align:start position:0% +interaction is intersecting with this + + + align:start position:0% +interaction is intersecting with this +interaction potential between a neutral + + align:start position:0% +interaction potential between a neutral + + + align:start position:0% +interaction potential between a neutral +sodium atom and a neutral chlorine atom + + align:start position:0% +sodium atom and a neutral chlorine atom + + + align:start position:0% +sodium atom and a neutral chlorine atom +right in + + align:start position:0% +right in + + + align:start position:0% +right in +there right at this value of R which + + align:start position:0% +there right at this value of R which + + + align:start position:0% +there right at this value of R which +we're going to call R + + align:start position:0% +we're going to call R + + + align:start position:0% +we're going to call R +star the potential energy of interaction + + align:start position:0% +star the potential energy of interaction + + + align:start position:0% +star the potential energy of interaction +from here to + + align:start position:0% +from here to + + + align:start position:0% +from here to +here right is equal + + align:start position:0% +here right is equal + + + align:start position:0% +here right is equal +to the sum of this ionization energy + + align:start position:0% +to the sum of this ionization energy + + + align:start position:0% +to the sum of this ionization energy +minus the electron + + align:start position:0% +minus the electron + + + align:start position:0% +minus the electron +affinity right + + align:start position:0% +affinity right + + + align:start position:0% +affinity right +here the electron can jump + + align:start position:0% +here the electron can jump + + + align:start position:0% +here the electron can jump +without having to put any energy into + + align:start position:0% +without having to put any energy into + + + align:start position:0% +without having to put any energy into +the + + align:start position:0% +the + + + align:start position:0% +the +system you're close enough for the + + align:start position:0% +system you're close enough for the + + + align:start position:0% +system you're close enough for the +electron to + + align:start position:0% +electron to + + + align:start position:0% +electron to +jump right because that colum + + align:start position:0% +jump right because that colum + + + align:start position:0% +jump right because that colum +interaction + + align:start position:0% +interaction + + + align:start position:0% +interaction +is has gotten lower and it's at right + + align:start position:0% +is has gotten lower and it's at right + + + align:start position:0% +is has gotten lower and it's at right +that + + align:start position:0% +that + + + align:start position:0% +that +point when you can have that electron + + align:start position:0% +point when you can have that electron + + + align:start position:0% +point when you can have that electron +transfer and not have to put any energy + + align:start position:0% +transfer and not have to put any energy + + + align:start position:0% +transfer and not have to put any energy +into the system to get it to go all + + align:start position:0% +into the system to get it to go all + + + align:start position:0% +into the system to get it to go all +right so in other + + align:start position:0% +right so in other + + + align:start position:0% +right so in other +words right + + align:start position:0% +words right + + + align:start position:0% +words right +here right the energy from right there + + align:start position:0% +here right the energy from right there + + + align:start position:0% +here right the energy from right there +to this point is minus E star 4 Pi + + align:start position:0% +to this point is minus E star 4 Pi + + + align:start position:0% +to this point is minus E star 4 Pi +Epsilon KN minus e^ 2 4 Pi Epsilon + + align:start position:0% +Epsilon KN minus e^ 2 4 Pi Epsilon + + + align:start position:0% +Epsilon KN minus e^ 2 4 Pi Epsilon +RAR all + + align:start position:0% +RAR all + + + align:start position:0% +RAR all +right that + + align:start position:0% +right that + + + align:start position:0% +right that +energy right at that point is equal to + + align:start position:0% +energy right at that point is equal to + + + align:start position:0% +energy right at that point is equal to +if I'm measuring here from the top now + + align:start position:0% +if I'm measuring here from the top now + + + align:start position:0% +if I'm measuring here from the top now +minus the quantity ionization energy of + + align:start position:0% +minus the quantity ionization energy of + + + align:start position:0% +minus the quantity ionization energy of +sodium minus the electron Affinity of + + align:start position:0% +sodium minus the electron Affinity of + + + align:start position:0% +sodium minus the electron Affinity of +chlorine all right so in order to solve + + align:start position:0% +chlorine all right so in order to solve + + + align:start position:0% +chlorine all right so in order to solve +for this distance r at which the + + align:start position:0% +for this distance r at which the + + + align:start position:0% +for this distance r at which the +electron jumps at which that electron + + align:start position:0% +electron jumps at which that electron + + + align:start position:0% +electron jumps at which that electron +jump is energetically allowed I'm going + + align:start position:0% +jump is energetically allowed I'm going + + + align:start position:0% +jump is energetically allowed I'm going +to set this equal to this I know what + + align:start position:0% +to set this equal to this I know what + + + align:start position:0% +to set this equal to this I know what +the ionization energy and electron + + align:start position:0% +the ionization energy and electron + + + align:start position:0% +the ionization energy and electron +affinity of uh sodium and chlorine R I + + align:start position:0% +affinity of uh sodium and chlorine R I + + + align:start position:0% +affinity of uh sodium and chlorine R I +know everything except our star so I'm + + align:start position:0% +know everything except our star so I'm + + + align:start position:0% +know everything except our star so I'm +going to solve for our star + + align:start position:0% +going to solve for our star + + + align:start position:0% +going to solve for our star +all right so let's do that I'm going to + + align:start position:0% +all right so let's do that I'm going to + + + align:start position:0% +all right so let's do that I'm going to +need the lights + + align:start position:0% + + + + align:start position:0% + +here all right so if I rearrange that + + align:start position:0% +here all right so if I rearrange that + + + align:start position:0% +here all right so if I rearrange that +equation R star is equal to + + align:start position:0% +equation R star is equal to + + + align:start position:0% +equation R star is equal to +e^2 over 4 Pi + + align:start position:0% +e^2 over 4 Pi + + + align:start position:0% +e^2 over 4 Pi +Epsilon time the ionization energy of + + align:start position:0% +Epsilon time the ionization energy of + + + align:start position:0% +Epsilon time the ionization energy of +sodium minus the electron affinity of + + align:start position:0% +sodium minus the electron affinity of + + + align:start position:0% +sodium minus the electron affinity of +chlorine + + align:start position:0% + + + + align:start position:0% + +okay I know what e is it's + + align:start position:0% +okay I know what e is it's + + + align:start position:0% +okay I know what e is it's +1.62 * + + align:start position:0% +1.62 * + + + align:start position:0% +1.62 * +10-19 Kum + + align:start position:0% +10-19 Kum + + + align:start position:0% +10-19 Kum +squared I have a 4 Pi Epsilon KN I know + + align:start position:0% +squared I have a 4 Pi Epsilon KN I know + + + align:start position:0% +squared I have a 4 Pi Epsilon KN I know +what Epsilon KN is and then the + + align:start position:0% +what Epsilon KN is and then the + + + align:start position:0% +what Epsilon KN is and then the +difference between the ionization energy + + align:start position:0% +difference between the ionization energy + + + align:start position:0% +difference between the ionization energy +and the electron affinity I calculated + + align:start position:0% +and the electron affinity I calculated + + + align:start position:0% +and the electron affinity I calculated +over there that's 147 K per + + align:start position:0% +over there that's 147 K per + + + align:start position:0% +over there that's 147 K per +mole or + + align:start position:0% +mole or + + + align:start position:0% +mole or +1.47 * 10 5th Jewel per + + align:start position:0% + + + + align:start position:0% + +mole okay but now and this is what + + align:start position:0% +mole okay but now and this is what + + + align:start position:0% +mole okay but now and this is what +everybody forgets on an + + align:start position:0% +everybody forgets on an + + + align:start position:0% +everybody forgets on an +exam all + + align:start position:0% +exam all + + + align:start position:0% +exam all +right I have to calculate R star per + + align:start position:0% +right I have to calculate R star per + + + align:start position:0% +right I have to calculate R star per +molecule not per mole because per mole + + align:start position:0% +molecule not per mole because per mole + + + align:start position:0% +molecule not per mole because per mole +doesn't make sense and I got this energy + + align:start position:0% +doesn't make sense and I got this energy + + + align:start position:0% +doesn't make sense and I got this energy +written here per mole so I need need an + + align:start position:0% +written here per mole so I need need an + + + align:start position:0% +written here per mole so I need need an +avagadro number up here 6.022 * 10 20 + + align:start position:0% +avagadro number up here 6.022 * 10 20 + + + align:start position:0% +avagadro number up here 6.022 * 10 20 +23 per + + align:start position:0% +23 per + + + align:start position:0% +23 per +mole all right don't forget avagadro's + + align:start position:0% +mole all right don't forget avagadro's + + + align:start position:0% +mole all right don't forget avagadro's +number when you calculate + + align:start position:0% +number when you calculate + + + align:start position:0% +number when you calculate +R so what's our star we're all our star + + align:start position:0% +R so what's our star we're all our star + + + align:start position:0% +R so what's our star we're all our star +comes out to be + + align:start position:0% +comes out to be + + + align:start position:0% +comes out to be +9.45 * 10- 10 + + align:start position:0% + + + + align:start position:0% + +m + + align:start position:0% +m + + + align:start position:0% +m +okay so let's get a perspective on these + + align:start position:0% +okay so let's get a perspective on these + + + align:start position:0% +okay so let's get a perspective on these +distances + + align:start position:0% +distances + + + align:start position:0% +distances +the sodium atom here that sodium atom + + align:start position:0% +the sodium atom here that sodium atom + + + align:start position:0% +the sodium atom here that sodium atom +diameter 3.8 + + align:start position:0% + + + + align:start position:0% + +angstroms chlorine atom + + align:start position:0% +angstroms chlorine atom + + + align:start position:0% +angstroms chlorine atom +diameter two + + align:start position:0% +diameter two + + + align:start position:0% +diameter two +angstroms what I'm saying is that this + + align:start position:0% +angstroms what I'm saying is that this + + + align:start position:0% +angstroms what I'm saying is that this +electron can jump or does jump from + + align:start position:0% +electron can jump or does jump from + + + align:start position:0% +electron can jump or does jump from +sodium to chlorine at this distance our + + align:start position:0% +sodium to chlorine at this distance our + + + align:start position:0% +sodium to chlorine at this distance our +star which is equal to 9.45 + + align:start position:0% +star which is equal to 9.45 + + + align:start position:0% +star which is equal to 9.45 +enroms okay so the sodium and the + + align:start position:0% +enroms okay so the sodium and the + + + align:start position:0% +enroms okay so the sodium and the +chlorine really are a considerable + + align:start position:0% +chlorine really are a considerable + + + align:start position:0% +chlorine really are a considerable +distance apart when that electron jumps + + align:start position:0% +distance apart when that electron jumps + + + align:start position:0% +distance apart when that electron jumps +but that electron can jump because it is + + align:start position:0% +but that electron can jump because it is + + + align:start position:0% +but that electron can jump because it is +at that point that the Kum + + align:start position:0% +at that point that the Kum + + + align:start position:0% +at that point that the Kum +interaction is large enough + + align:start position:0% +interaction is large enough + + + align:start position:0% +interaction is large enough +here right to compensate for the + + align:start position:0% +here right to compensate for the + + + align:start position:0% +here right to compensate for the +difference in the ionization energy and + + align:start position:0% +difference in the ionization energy and + + + align:start position:0% +difference in the ionization energy and +the electron + + align:start position:0% +the electron + + + align:start position:0% +the electron +affinity and this actual number here was + + align:start position:0% +affinity and this actual number here was + + + align:start position:0% +affinity and this actual number here was +was verified in these experiments um by + + align:start position:0% +was verified in these experiments um by + + + align:start position:0% +was verified in these experiments um by +hersbach and uh + + align:start position:0% +hersbach and uh + + + align:start position:0% +hersbach and uh +lee right it actually does happen and + + align:start position:0% +lee right it actually does happen and + + + align:start position:0% +lee right it actually does happen and +this very simple model classical model + + align:start position:0% +this very simple model classical model + + + align:start position:0% +this very simple model classical model +where we're actually treating the sodium + + align:start position:0% +where we're actually treating the sodium + + + align:start position:0% +where we're actually treating the sodium +and the chlorine as point charges we've + + align:start position:0% +and the chlorine as point charges we've + + + align:start position:0% +and the chlorine as point charges we've +forgotten everything else about the + + align:start position:0% +forgotten everything else about the + + + align:start position:0% +forgotten everything else about the +electrons hey that works remarkably well + + align:start position:0% +electrons hey that works remarkably well + + + align:start position:0% +electrons hey that works remarkably well +right now what this model doesn't give + + align:start position:0% +right now what this model doesn't give + + + align:start position:0% +right now what this model doesn't give +you very well is the bond + + align:start position:0% +you very well is the bond + + + align:start position:0% +you very well is the bond +energy all right because if you look at + + align:start position:0% +energy all right because if you look at + + + align:start position:0% +energy all right because if you look at +this diagram again right in here oh let + + align:start position:0% +this diagram again right in here oh let + + + align:start position:0% +this diagram again right in here oh let +me go back one here if you look at this + + align:start position:0% +me go back one here if you look at this + + + align:start position:0% +me go back one here if you look at this +diagram this 147 K here well that I can + + align:start position:0% +diagram this 147 K here well that I can + + + align:start position:0% +diagram this 147 K here well that I can +look + + align:start position:0% +look + + + align:start position:0% +look +up this 592 + + align:start position:0% +up this 592 + + + align:start position:0% +up this 592 +K well that's just the coolum + + align:start position:0% +K well that's just the coolum + + + align:start position:0% +K well that's just the coolum +interaction between a positive and a + + align:start position:0% +interaction between a positive and a + + + align:start position:0% +interaction between a positive and a +negative charge at 2.36 EV that's all + + align:start position:0% +negative charge at 2.36 EV that's all + + + align:start position:0% +negative charge at 2.36 EV that's all +that is you can calculate + + align:start position:0% +that is you can calculate + + + align:start position:0% +that is you can calculate +that and so + + align:start position:0% +that and so + + + align:start position:0% +that and so +therefore if I want to calculate the + + align:start position:0% +therefore if I want to calculate the + + + align:start position:0% +therefore if I want to calculate the +bond energy of sodium + + align:start position:0% +bond energy of sodium + + + align:start position:0% +bond energy of sodium +chloride right the bond energy is just + + align:start position:0% +chloride right the bond energy is just + + + align:start position:0% +chloride right the bond energy is just +the difference between this energy and + + align:start position:0% +the difference between this energy and + + + align:start position:0% +the difference between this energy and +that energy and that's + + align:start position:0% +that energy and that's + + + align:start position:0% +that energy and that's +445 KJ per + + align:start position:0% +445 KJ per + + + align:start position:0% +445 KJ per +mole well that doesn't come out so well + + align:start position:0% +mole well that doesn't come out so well + + + align:start position:0% +mole well that doesn't come out so well +in terms of the actual Bond energy the + + align:start position:0% +in terms of the actual Bond energy the + + + align:start position:0% +in terms of the actual Bond energy the +actual bond energy is 412 K per + + align:start position:0% +actual bond energy is 412 K per + + + align:start position:0% +actual bond energy is 412 K per +mole and we know why that didn't come + + align:start position:0% +mole and we know why that didn't come + + + align:start position:0% +mole and we know why that didn't come +out too + + align:start position:0% +out too + + + align:start position:0% +out too +well and uh that's because this depends + + align:start position:0% +well and uh that's because this depends + + + align:start position:0% +well and uh that's because this depends +on all of the interactions that are much + + align:start position:0% +on all of the interactions that are much + + + align:start position:0% +on all of the interactions that are much +closer in to the + + align:start position:0% +closer in to the + + + align:start position:0% +closer in to the +nucleus by the time you get down here + + align:start position:0% +nucleus by the time you get down here + + + align:start position:0% +nucleus by the time you get down here +right the repulsive interactions are are + + align:start position:0% +right the repulsive interactions are are + + + align:start position:0% +right the repulsive interactions are are +present the nuclear nuclear compulsions + + align:start position:0% +present the nuclear nuclear compulsions + + + align:start position:0% +present the nuclear nuclear compulsions +are + + align:start position:0% +are + + + align:start position:0% +are +present and in our simple model we + + align:start position:0% +present and in our simple model we + + + align:start position:0% +present and in our simple model we +didn't take that into account the + + align:start position:0% +didn't take that into account the + + + align:start position:0% +didn't take that into account the +nuclear nuclear + + align:start position:0% +nuclear nuclear + + + align:start position:0% +nuclear nuclear +repulsions this simple model worked to + + align:start position:0% +repulsions this simple model worked to + + + align:start position:0% +repulsions this simple model worked to +get our star because our star is further + + align:start position:0% +get our star because our star is further + + + align:start position:0% +get our star because our star is further +out you know the nuclear nuclear + + align:start position:0% +out you know the nuclear nuclear + + + align:start position:0% +out you know the nuclear nuclear +repulsions haven't haven't really set in + + align:start position:0% +repulsions haven't haven't really set in + + + align:start position:0% +repulsions haven't haven't really set in +yet and therefore the simple model works + + align:start position:0% +yet and therefore the simple model works + + + align:start position:0% +yet and therefore the simple model works +when you're at a far distance when R is + + align:start position:0% +when you're at a far distance when R is + + + align:start position:0% +when you're at a far distance when R is +large but to get the bond strength here + + align:start position:0% +large but to get the bond strength here + + + align:start position:0% +large but to get the bond strength here +you're much closer in right you're at + + align:start position:0% +you're much closer in right you're at + + + align:start position:0% +you're much closer in right you're at +2.36 angstroms that's the dist uh + + align:start position:0% +2.36 angstroms that's the dist uh + + + align:start position:0% +2.36 angstroms that's the dist uh +difference in energy from here to there + + align:start position:0% +difference in energy from here to there + + + align:start position:0% +difference in energy from here to there +hey we forgot about the repulsive + + align:start position:0% +hey we forgot about the repulsive + + + align:start position:0% +hey we forgot about the repulsive +interactions between the two + + align:start position:0% +interactions between the two + + + align:start position:0% +interactions between the two +nuclei so the model isn't going to work + + align:start position:0% +nuclei so the model isn't going to work + + + align:start position:0% +nuclei so the model isn't going to work +so close into the nucleus but it does a + + align:start position:0% +so close into the nucleus but it does a + + + align:start position:0% +so close into the nucleus but it does a +really good job of getting our + + align:start position:0% +really good job of getting our + + + align:start position:0% +really good job of getting our +star far away from the + + align:start position:0% +star far away from the + + + align:start position:0% +star far away from the +nucleus now again this simple model only + + align:start position:0% +nucleus now again this simple model only + + + align:start position:0% +nucleus now again this simple model only +works for very ionic compounds very + + align:start position:0% +works for very ionic compounds very + + + align:start position:0% +works for very ionic compounds very +ionic bonds like sodium chloride it + + align:start position:0% +ionic bonds like sodium chloride it + + + align:start position:0% +ionic bonds like sodium chloride it +won't work very well for hydrogen + + align:start position:0% +won't work very well for hydrogen + + + align:start position:0% +won't work very well for hydrogen +chloride for example all + + align:start position:0% +chloride for example all + + + align:start position:0% +chloride for example all +right okay questions on + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +yes all right we're going to deal with + + align:start position:0% +yes all right we're going to deal with + + + align:start position:0% +yes all right we're going to deal with +entrop and Gibs free energy changes in a + + align:start position:0% +entrop and Gibs free energy changes in a + + + align:start position:0% +entrop and Gibs free energy changes in a +week or two right now what I'm writing + + align:start position:0% +week or two right now what I'm writing + + + align:start position:0% +week or two right now what I'm writing +here are energy changes and so I'm + + align:start position:0% +here are energy changes and so I'm + + + align:start position:0% +here are energy changes and so I'm +actually dealing with single molecules I + + align:start position:0% +actually dealing with single molecules I + + + align:start position:0% +actually dealing with single molecules I +might have in my mind here writing the + + align:start position:0% +might have in my mind here writing the + + + align:start position:0% +might have in my mind here writing the +energies per mole but what I'm thinking + + align:start position:0% +energies per mole but what I'm thinking + + + align:start position:0% +energies per mole but what I'm thinking +about is not an ensemble of molecules + + align:start position:0% +about is not an ensemble of molecules + + + align:start position:0% +about is not an ensemble of molecules +I'm actually thinking about what's + + align:start position:0% +I'm actually thinking about what's + + + align:start position:0% +I'm actually thinking about what's +happening in each + + align:start position:0% +happening in each + + + align:start position:0% +happening in each +individual single molecule interaction + + align:start position:0% +individual single molecule interaction + + + align:start position:0% +individual single molecule interaction +that's why I haven't talked about Delta + + align:start position:0% +that's why I haven't talked about Delta + + + align:start position:0% +that's why I haven't talked about Delta +G here at all okay and in chemical + + align:start position:0% +G here at all okay and in chemical + + + align:start position:0% +G here at all okay and in chemical +dynamics that field of chemical dynamics + + align:start position:0% +dynamics that field of chemical dynamics + + + align:start position:0% +dynamics that field of chemical dynamics +that is where we want to look at + + align:start position:0% +that is where we want to look at + + + align:start position:0% +that is where we want to look at +individual events as opposed to a + + align:start position:0% +individual events as opposed to a + + + align:start position:0% +individual events as opposed to a +boltzman average of events okay so + + align:start position:0% +boltzman average of events okay so + + + align:start position:0% +boltzman average of events okay so +that's what I've that's what I'm talking + + align:start position:0% +that's what I've that's what I'm talking + + + align:start position:0% +that's what I've that's what I'm talking +about right here all right but we're + + align:start position:0% +about right here all right but we're + + + align:start position:0% +about right here all right but we're +going to talk about collections of + + align:start position:0% +going to talk about collections of + + + align:start position:0% +going to talk about collections of +molecules and the energy changes I'm + + align:start position:0% +molecules and the energy changes I'm + + + align:start position:0% +molecules and the energy changes I'm +going to change my definition from Delta + + align:start position:0% +going to change my definition from Delta + + + align:start position:0% +going to change my definition from Delta +e to Delta H the bond enthalpy in a + + align:start position:0% +e to Delta H the bond enthalpy in a + + + align:start position:0% +e to Delta H the bond enthalpy in a +couple of days or so + + align:start position:0% +couple of days or so + + + align:start position:0% +couple of days or so +okay other + + align:start position:0% +okay other + + + align:start position:0% +okay other +questions + + align:start position:0% +questions + + + align:start position:0% +questions +okay well there's one other + + align:start position:0% +okay well there's one other + + + align:start position:0% +okay well there's one other +um there's one other uh just a rather + + align:start position:0% +um there's one other uh just a rather + + + align:start position:0% +um there's one other uh just a rather +brief topic that I wanted to talk about + + align:start position:0% +brief topic that I wanted to talk about + + + align:start position:0% +brief topic that I wanted to talk about +and that is uh calculating dipole + + align:start position:0% +and that is uh calculating dipole + + + align:start position:0% +and that is uh calculating dipole +moments where um + + align:start position:0% +moments where um + + + align:start position:0% +moments where um +and then from or measuring dipole + + align:start position:0% +and then from or measuring dipole + + + align:start position:0% +and then from or measuring dipole +moments and then from the dipole moments + + align:start position:0% +moments and then from the dipole moments + + + align:start position:0% +moments and then from the dipole moments +getting out some uh ionic character to a + + align:start position:0% +getting out some uh ionic character to a + + + align:start position:0% +getting out some uh ionic character to a +chemical + + align:start position:0% +chemical + + + align:start position:0% +chemical +bond so your book actually calls ionic + + align:start position:0% +bond so your book actually calls ionic + + + align:start position:0% +bond so your book actually calls ionic +bonds calls them polar Cove valent bonds + + align:start position:0% +bonds calls them polar Cove valent bonds + + + align:start position:0% +bonds calls them polar Cove valent bonds +and that's fine because even a very + + align:start position:0% +and that's fine because even a very + + + align:start position:0% +and that's fine because even a very +ionic bond like sodium chloride isn't + + align:start position:0% +ionic bond like sodium chloride isn't + + + align:start position:0% +ionic bond like sodium chloride isn't +completely ionic in the sense that when + + align:start position:0% +completely ionic in the sense that when + + + align:start position:0% +completely ionic in the sense that when +it's the molecule you know it's not a + + align:start position:0% +it's the molecule you know it's not a + + + align:start position:0% +it's the molecule you know it's not a +point + + align:start position:0% +point + + + align:start position:0% +point +charge on sodium and a point charge on + + align:start position:0% +charge on sodium and a point charge on + + + align:start position:0% +charge on sodium and a point charge on +chlorine you've got an electron + + align:start position:0% +chlorine you've got an electron + + + align:start position:0% +chlorine you've got an electron +distribution right when you're that + + align:start position:0% + + + + align:start position:0% + +close and so what you've got in an ionic + + align:start position:0% +close and so what you've got in an ionic + + + align:start position:0% +close and so what you've got in an ionic +bond or a polar calent bond here what + + align:start position:0% +bond or a polar calent bond here what + + + align:start position:0% +bond or a polar calent bond here what +you have is an asymmetric charge + + align:start position:0% +you have is an asymmetric charge + + + align:start position:0% +you have is an asymmetric charge +distribution you know in an HCL here + + align:start position:0% +distribution you know in an HCL here + + + align:start position:0% +distribution you know in an HCL here +you've got the both electrons on the + + align:start position:0% +you've got the both electrons on the + + + align:start position:0% +you've got the both electrons on the +average + + align:start position:0% +average + + + align:start position:0% +average +being being closer to the chlorine + + align:start position:0% +being being closer to the chlorine + + + align:start position:0% +being being closer to the chlorine +nucleus than it is to the hydrogen + + align:start position:0% +nucleus than it is to the hydrogen + + + align:start position:0% +nucleus than it is to the hydrogen +nucleus and you have that because you + + align:start position:0% +nucleus and you have that because you + + + align:start position:0% +nucleus and you have that because you +have a bond between atoms with two very + + align:start position:0% +have a bond between atoms with two very + + + align:start position:0% +have a bond between atoms with two very +different electr + + align:start position:0% +different electr + + + align:start position:0% +different electr +negativities so that's a polar calent + + align:start position:0% +negativities so that's a polar calent + + + align:start position:0% +negativities so that's a polar calent +bond now what we're going to do is we're + + align:start position:0% +bond now what we're going to do is we're + + + align:start position:0% +bond now what we're going to do is we're +going to use this symbol Delta here as a + + align:start position:0% +going to use this symbol Delta here as a + + + align:start position:0% +going to use this symbol Delta here as a +measure of the amount of energy amount + + align:start position:0% +measure of the amount of energy amount + + + align:start position:0% +measure of the amount of energy amount +of electron transfer so Delta is the + + align:start position:0% +of electron transfer so Delta is the + + + align:start position:0% +of electron transfer so Delta is the +fraction of a full charge that's + + align:start position:0% +fraction of a full charge that's + + + align:start position:0% +fraction of a full charge that's +asymmetrically dist distributed so this + + align:start position:0% +asymmetrically dist distributed so this + + + align:start position:0% +asymmetrically dist distributed so this +plus Delta or this Delta that was on the + + align:start position:0% +plus Delta or this Delta that was on the + + + align:start position:0% +plus Delta or this Delta that was on the +hydrogen is now on the chlorine is the + + align:start position:0% +hydrogen is now on the chlorine is the + + + align:start position:0% +hydrogen is now on the chlorine is the +interpretation of that + + align:start position:0% +interpretation of that + + + align:start position:0% +interpretation of that +symbol that asymmetric charge + + align:start position:0% +symbol that asymmetric charge + + + align:start position:0% +symbol that asymmetric charge +distribution leads to a dipole + + align:start position:0% +distribution leads to a dipole + + + align:start position:0% +distribution leads to a dipole +moment a dipole moment is defined as Q + + align:start position:0% +moment a dipole moment is defined as Q + + + align:start position:0% +moment a dipole moment is defined as Q +where Q is the magnitude of the charge + + align:start position:0% +where Q is the magnitude of the charge + + + align:start position:0% +where Q is the magnitude of the charge +separation times R where R is that + + align:start position:0% +separation times R where R is that + + + align:start position:0% +separation times R where R is that +charge separation it is strictly + + align:start position:0% +charge separation it is strictly + + + align:start position:0% +charge separation it is strictly +speaking a vector all + + align:start position:0% +speaking a vector all + + + align:start position:0% +speaking a vector all +right Q * R is what we Define as a + + align:start position:0% +right Q * R is what we Define as a + + + align:start position:0% +right Q * R is what we Define as a +dipole + + align:start position:0% +dipole + + + align:start position:0% +dipole +moment the units the dipole moment is + + align:start position:0% +moment the units the dipole moment is + + + align:start position:0% +moment the units the dipole moment is +kums times meters you can see that from + + align:start position:0% +kums times meters you can see that from + + + align:start position:0% +kums times meters you can see that from +Q * + + align:start position:0% +Q * + + + align:start position:0% +Q * +R dipole moment is also a vector I had + + align:start position:0% +R dipole moment is also a vector I had + + + align:start position:0% +R dipole moment is also a vector I had +the vector on this + + align:start position:0% +the vector on this + + + align:start position:0% +the vector on this +slide going from the positively charged + + align:start position:0% +slide going from the positively charged + + + align:start position:0% +slide going from the positively charged +end to the negatively charged then + + align:start position:0% +end to the negatively charged then + + + align:start position:0% +end to the negatively charged then +that's the way your present book does it + + align:start position:0% +that's the way your present book does it + + + align:start position:0% +that's the way your present book does it +in your notes I have It reversed I have + + align:start position:0% +in your notes I have It reversed I have + + + align:start position:0% +in your notes I have It reversed I have +It reversed because the last time I + + align:start position:0% +It reversed because the last time I + + + align:start position:0% +It reversed because the last time I +taught this I was using a book that used + + align:start position:0% +taught this I was using a book that used + + + align:start position:0% +taught this I was using a book that used +a different notation and I sent it out + + align:start position:0% +a different notation and I sent it out + + + align:start position:0% +a different notation and I sent it out +for xeroxing before I realized this was + + align:start position:0% +for xeroxing before I realized this was + + + align:start position:0% +for xeroxing before I realized this was +different so change it around not that + + align:start position:0% +different so change it around not that + + + align:start position:0% +different so change it around not that +it's ever going to make any difference + + align:start position:0% +it's ever going to make any difference + + + align:start position:0% +it's ever going to make any difference +okay but your book has this convention + + align:start position:0% +okay but your book has this convention + + + align:start position:0% +okay but your book has this convention +from positive to + + align:start position:0% + + + + align:start position:0% + +negative + + align:start position:0% +negative + + + align:start position:0% +negative +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now this unit though of a kulon meter is + + align:start position:0% +now this unit though of a kulon meter is + + + align:start position:0% +now this unit though of a kulon meter is +a very large unit An Inconvenient unit + + align:start position:0% +a very large unit An Inconvenient unit + + + align:start position:0% +a very large unit An Inconvenient unit +so we got another unit it's called a + + align:start position:0% +so we got another unit it's called a + + + align:start position:0% +so we got another unit it's called a +Dubai named after Peter Dubai who first + + align:start position:0% +Dubai named after Peter Dubai who first + + + align:start position:0% +Dubai named after Peter Dubai who first +studied these uh polar coent + + align:start position:0% +studied these uh polar coent + + + align:start position:0% +studied these uh polar coent +molecules and to buy here is defined as + + align:start position:0% +molecules and to buy here is defined as + + + align:start position:0% +molecules and to buy here is defined as +the + + align:start position:0% +the + + + align:start position:0% +the +following it is defined as if you have a + + align:start position:0% +following it is defined as if you have a + + + align:start position:0% +following it is defined as if you have a +a full unit charge now not a Delta a + + align:start position:0% +a full unit charge now not a Delta a + + + align:start position:0% +a full unit charge now not a Delta a +full unit charge moved from here to here + + align:start position:0% +full unit charge moved from here to here + + + align:start position:0% +full unit charge moved from here to here +and the charge is separated + + align:start position:0% +and the charge is separated + + + align:start position:0% +and the charge is separated +by28 + + align:start position:0% +by28 + + + align:start position:0% +by28 +angstroms that defines this unit called + + align:start position:0% +angstroms that defines this unit called + + + align:start position:0% +angstroms that defines this unit called +the + + align:start position:0% +the + + + align:start position:0% +the +Debby all + + align:start position:0% +Debby all + + + align:start position:0% +Debby all +right so they're 028 angstroms per + + align:start position:0% +right so they're 028 angstroms per + + + align:start position:0% +right so they're 028 angstroms per +divide + + align:start position:0% + + + + align:start position:0% + +so if you knew the fraction of + + align:start position:0% +so if you knew the fraction of + + + align:start position:0% +so if you knew the fraction of +charge that is separated and you knew + + align:start position:0% +charge that is separated and you knew + + + align:start position:0% +charge that is separated and you knew +the bond length in + + align:start position:0% +the bond length in + + + align:start position:0% +the bond length in +angstroms and then you have our + + align:start position:0% +angstroms and then you have our + + + align:start position:0% +angstroms and then you have our +definition for a deby which is 208 + + align:start position:0% +definition for a deby which is 208 + + + align:start position:0% +definition for a deby which is 208 +angstroms per dubby you could get + + align:start position:0% +angstroms per dubby you could get + + + align:start position:0% +angstroms per dubby you could get +calculate the dipole moment in + + align:start position:0% +calculate the dipole moment in + + + align:start position:0% +calculate the dipole moment in +Dubai but usually what we do is not to + + align:start position:0% +Dubai but usually what we do is not to + + + align:start position:0% +Dubai but usually what we do is not to +calculate the dipole moment + + align:start position:0% +calculate the dipole moment + + + align:start position:0% +calculate the dipole moment +we usually measure the dipole moment and + + align:start position:0% +we usually measure the dipole moment and + + + align:start position:0% +we usually measure the dipole moment and +calculate the partial charge + + align:start position:0% +calculate the partial charge + + + align:start position:0% +calculate the partial charge +distribution because we usually don't + + align:start position:0% +distribution because we usually don't + + + align:start position:0% +distribution because we usually don't +know this we can measure + + align:start position:0% +know this we can measure + + + align:start position:0% +know this we can measure +that we can measure the dipole moments + + align:start position:0% +that we can measure the dipole moments + + + align:start position:0% +that we can measure the dipole moments +in a kind of capacitor + + align:start position:0% +in a kind of capacitor + + + align:start position:0% +in a kind of capacitor +Arrangement where we have some molecules + + align:start position:0% +Arrangement where we have some molecules + + + align:start position:0% +Arrangement where we have some molecules +that have a dipole moment positive + + align:start position:0% +that have a dipole moment positive + + + align:start position:0% +that have a dipole moment positive +charge on one plate negative charge on + + align:start position:0% +charge on one plate negative charge on + + + align:start position:0% +charge on one plate negative charge on +the + + align:start position:0% +the + + + align:start position:0% +the +other and when you do that of course + + align:start position:0% +other and when you do that of course + + + align:start position:0% +other and when you do that of course +these dipoles are going to align these + + align:start position:0% +these dipoles are going to align these + + + align:start position:0% +these dipoles are going to align these +electric dipoles are going to align + + align:start position:0% +electric dipoles are going to align + + + align:start position:0% +electric dipoles are going to align +that's going to change the + + align:start position:0% +that's going to change the + + + align:start position:0% +that's going to change the +capacitance if this capacitor is part of + + align:start position:0% +capacitance if this capacitor is part of + + + align:start position:0% +capacitance if this capacitor is part of +a resonance circuit it's going to turn + + align:start position:0% +a resonance circuit it's going to turn + + + align:start position:0% +a resonance circuit it's going to turn +change the resonant frequency the + + align:start position:0% +change the resonant frequency the + + + align:start position:0% +change the resonant frequency the +resonant frequency is related to the + + align:start position:0% +resonant frequency is related to the + + + align:start position:0% +resonant frequency is related to the +dipole + + align:start position:0% +dipole + + + align:start position:0% +dipole +moment and in that way you calculate the + + align:start position:0% +moment and in that way you calculate the + + + align:start position:0% +moment and in that way you calculate the +dipole moment or measure the dipole + + align:start position:0% +dipole moment or measure the dipole + + + align:start position:0% +dipole moment or measure the dipole +moment and that's how it was originally + + align:start position:0% +moment and that's how it was originally + + + align:start position:0% +moment and that's how it was originally +done however you can now measure dipole + + align:start position:0% +done however you can now measure dipole + + + align:start position:0% +done however you can now measure dipole +moments very accurately by rotational + + align:start position:0% +moments very accurately by rotational + + + align:start position:0% +moments very accurately by rotational +spectroscopy and we're going to look at + + align:start position:0% +spectroscopy and we're going to look at + + + align:start position:0% +spectroscopy and we're going to look at +that in a in a few lectures or so but + + align:start position:0% +that in a in a few lectures or so but + + + align:start position:0% +that in a in a few lectures or so but +take HCL right here here's HCL here's + + align:start position:0% +take HCL right here here's HCL here's + + + align:start position:0% +take HCL right here here's HCL here's +the measured dipole moment here's the + + align:start position:0% +the measured dipole moment here's the + + + align:start position:0% +the measured dipole moment here's the +bond length we can use these two pieces + + align:start position:0% +bond length we can use these two pieces + + + align:start position:0% +bond length we can use these two pieces +of information to calculate the partial + + align:start position:0% +of information to calculate the partial + + + align:start position:0% +of information to calculate the partial +the fraction of charge + + align:start position:0% +the fraction of charge + + + align:start position:0% +the fraction of charge +distributed and in the case of HCL that + + align:start position:0% +distributed and in the case of HCL that + + + align:start position:0% +distributed and in the case of HCL that +is about + + align:start position:0% +is about + + + align:start position:0% +is about +.18 sometimes we refer to this in in a + + align:start position:0% +.18 sometimes we refer to this in in a + + + align:start position:0% +.18 sometimes we refer to this in in a +percentage so this would be uh + + align:start position:0% +percentage so this would be uh + + + align:start position:0% +percentage so this would be uh +18% of a charge separation sometimes we + + align:start position:0% +18% of a charge separation sometimes we + + + align:start position:0% +18% of a charge separation sometimes we +say 18% ionic character in + + align:start position:0% +say 18% ionic character in + + + align:start position:0% +say 18% ionic character in +HCL that compares to something like 70% + + align:start position:0% +HCL that compares to something like 70% + + + align:start position:0% +HCL that compares to something like 70% +or 80% in sodium chloride or lithium + + align:start position:0% +or 80% in sodium chloride or lithium + + + align:start position:0% +or 80% in sodium chloride or lithium +fluoride so HCL isn't anywhere near as + + align:start position:0% +fluoride so HCL isn't anywhere near as + + + align:start position:0% +fluoride so HCL isn't anywhere near as +ionic it just the charge distribution + + align:start position:0% +ionic it just the charge distribution + + + align:start position:0% +ionic it just the charge distribution +isn't as asymmetric as it is in sodium + + align:start position:0% +isn't as asymmetric as it is in sodium + + + align:start position:0% +isn't as asymmetric as it is in sodium +chloride or lithium chloride + + align:start position:0% +chloride or lithium chloride + + + align:start position:0% +chloride or lithium chloride +okay all right thank you very much for + + align:start position:0% +okay all right thank you very much for + + + align:start position:0% +okay all right thank you very much for +hanging in here today it's been hot have + + align:start position:0% +hanging in here today it's been hot have + + + align:start position:0% +hanging in here today it's been hot have +a nice cool weekend see you next + + align:start position:0% +a nice cool weekend see you next + + + align:start position:0% +a nice cool weekend see you next +Wednesday \ No newline at end of file diff --git a/N2jFzZA1e14.txt b/N2jFzZA1e14.txt new file mode 100644 index 0000000000000000000000000000000000000000..301bceb43b631c229a934ddcb16a2abf6a0ecb24 --- /dev/null +++ b/N2jFzZA1e14.txt @@ -0,0 +1,1415 @@ +Good morning, class. Nice to see you here. + +Yesterday morning I was in Australia and today I'm here. + +And it's nice to be back. It's a long way home. + +We're talking today about the issues of growth and differentiation + +about normal cells becoming specialized into different types of + +cells throughout the body and how that leads ultimately to the issues + +of organismic cloning. And, to give you an overall + +background about this, I want to show you the way that a + +worm is put together. This is the worm C. elegans. + +I don't know how well this overhead will come out. + +You can see it reasonably well. So, this is the worm Caenorhabditis + +elegans. It's been an object of much study here. + +Bob Horowitz in our own department just got the Nobel Prize + +for his work on this. + +And the reason it's been the object of so much study is, + +in fact, that it's a relatively simple organism. + +It's the way that you and I looked about 600 million years ago when + +Metazoa, remember Metazoa means multicellular organisms, + +first arose on the face of the planet. Let's see if I have too + +much overlap here. Well, that's about the way it should + +look. Now, what's remarkable about this organism is it has something + +like 965 cells in the adult. The cells all descend from a + +fertilized egg. It happens to be that this worm is + +a hermaphrodite. So, you probably know + +hermaphrodites are both male and female and it can fertilize itself + +or two worms can get together and fertilize each other. + +Because, as you can see, it makes both eggs and it makes + +sperm. And what's most interesting is the finite number of cells in the + +body of the adult. As I said, it's 965, + +whose lineage can be traced through a pedigree that's given right up + +here. So, one can plot out, with great precision, how all the + +cells, how the egg cell and the fertilized egg divides in two, + +each of those cells divides again in two and how ultimately one has a + +whole series of different descendents from different branches + +of this very elaborate family tree. Now, one of the issues that we want + +to pursue is the fact that the genomes, in principle, + +all the cells in this organism are the same. That is to say whenever + +the cell goes through a cycle of growth and division the cell is + +genetically identical, yet phenotypically, yet the behavior + +reach of these cells becomes increasingly different. + +And here you can see the different lineage of cells. + +This organism devotes a disproportionately large amount of + +its anatomy to reproduction, much more even than we do. Here, + +this is the cuticle, the outer coat. Here's the vulva, the female organ. + +This is the male organ and a variety of other cells types. + +Here's the pharynx. And yet all the cells in all these organisms, + +with the exception of the gametes, remember gametes means sperm and egg + +are genetically identical. The gametes have only half the + +genetic content. Everybody else is identical, + +has a diploid genome, that is to say two copies of each gene. + +And one can trace this all out. And this represents one of the + +great mysteries of developmental biology, which is to say how are + +cells that genetically identical to one another genotypically identical + +to one another, phenotypically quite different one + +from the other? What makes them so different? + +In fact, this image that we have here, which in itself represents a + +stunning achievement, that is being able to trace the + +pedigree of each cell in the adult body is very different from our own + +lineage because, as I may have mentioned to you in + +the past, each of us goes through ten to the sixth mitoses in a + +lifetime, you and I. That's ten to the sixteen cell + +divisions. And at any one time we have roughly three times ten to the + +thirteenth cells in our body. So, that means, if you think about + +that carefully, the ratio between these two suggests + +there's roughly a hundred times more here than here, + +three hundred times more It means, roughly speaking, that our body + +turns over roughly a hundred times in our lifetime. + +That is to say the cells turnover. Not all of the cells, + +but that there's a continuing replacement of existing cells with + +new cells. After all, if, in fact, there were no such + +replacement than we might, as an adult, be formed of this many + +cells, and we would stay with the exact same number of cells + +throughout our lives. But this, in fact, is the number of + +cell divisions. And so, there's an enormous turnover + +which, right away on its surface, independent of the fact that it's an + +enormously large number, precludes one from really being able + +to draw out a pedigree like this, prevents anyone from really + +understanding how each particular cell can trace its line of decent + +back to the fertilized egg. So, what we really want to explore, + +in this lecture and the next one, is this major puzzle that one starts + +out with a fertilized egg. Let's say this is a fertilized egg. + +It divides in two. It divides in four. And through subsequent cycles + +of growth and division we ultimately end up with the adult. + +Already at the four-cell stage, here in a vertebrate embryo, these + +cells have begun to take different phenotypic paths. + +That is to say cells have begun to commit themselves into entering into + +one or another differentiation lineage. And when I say a + +differentiating lineage, I mean a group of cells which has + +already made the decision to become blood cells, to become gut, + +to become nerve cells and so forth. And these commitments already start + +here at the four-cell stage, and they continue to play themselves + +out until one reaches a newborn, and then thereafter one just grows + +bigger. One other important thing to show here is that this pedigree + +that I showed you here is not simply the result of exponential expansion + +of all the cells, because many cells, + +during the course of development, are actually weeded out from + +embryonic tissue. And this happens even in our own + +development. For example, here, if we look at our fingers, + +I remember now I talked about fingers about two weeks ago and got + +myself into some hot water. If we look at our fingers, you'll + +see here we have five fingers, God willing, and but early in + +embryogenesis our hand looks like a solid flap of tissue. + +And what happens, during the course of vertebra development, + +is that the tissue in between the beginning fingers is eliminated + +through the process of apoptosis. Apoptosis means programmed cell + +death. Apoptosis is equivalent to cell suicide. And what I mean by + +that is to say that development involves not only the exponential + +proliferation of cells but it involves the selective elimination + +of cells here in a very obvious anatomical way. + +It sometimes can be defective, in which case individuals are born + +with large webs between their fingers. And this is part of normal + +development. And the same can be said here. If there were no + +apoptosis during the development of this worm embryo then there would be + +vastly larger numbers of cells. We mentioned implicitly apoptosis + +during the development of the immune system, because recall there that + +bee cells, which are destine to produce antibodies, + +if they produce inappropriate kinds of antibodies, + +if they produce antibodies that are self-reactive, + +i.e., recognize some of the body's own proteins, those cells are + +eliminated by apoptosis. If they produce defective antibody + +molecules, they're eliminated by apoptosis. And, + +therefore, differentiation, which is what we're talking about + +here, involves not only the commitment of cells to a certain + +lineage, but the purpose of elimination of cells in certain + +parts of the organism in order to carve and sculpt out properly + +shaped tissue. Again, our fingers are one dramatic + +example of that. It turns out we can learn an awful + +lot about this process by studying one specialized adult tissue, + +which is to say the organs of hematopoiesis. + +And they'll teach us a lot about some of the lessons we need to learn + +about organismic development and differentiation. + +And when I use the word hematopoiesis, + +the term hematopoiesis, or the adjective hematopoietic + +refers to the creation, the formation of different kinds of + +blood cells. In fact, we know that all the cells + +in the blood descend in the organism from a common progenitor. + +And this progenitor is called a pluripotent stem cell. + +Pluripotent means that this stem cell, and we'll define a stem cell + +momentarily, this stem cell is able to create descendents which can + +commit themselves in a number of distinct directions. + +They can differentiate in a number of distinct directions. + +In this case, we see all these various kinds of white and red blood + +cells which descend from this pluripotent stem cell. + +And, as a consequence, we call it pluripotent because it + +has these multiple distinct types of differentiation lineages. + +So, here we talk about pluripotent. Later on I'll talk about totipotent + +cells. Totipotent are cells that can do everything. + +Therefore, in fact, what's a totipotent cell? + +Well, a cell in the early embryo, including a fertilized egg is + +totipotent in that it can direct its descendents into all of the + +differentiation lineages in the body. Here we have a cell that's already + +more limited. It's only pluripotent, pluri in the sense of multiple + +but not total. Totipotent obviously means it can do + +everything. And here we see the different kinds of derivative white + +blood cells that exists in the bone marrow and in the circulation, + +and there's a whole series of different ones of them. + +We'll talk about some of them shortly, but we've already + +encountered some of them up here in the form of T cells and B cells. + +When we use the word stem cell the essence of the definition + +is as follows. A stem cell is a cell that can + +self-renew and it can also have a differentiated daughter. + +So, here's the way one can diagram a stem cell. Here's a stem cell + +that has two daughter cells. One daughter cell is exactly like + +Mom and the other daughter cell has undertaken a program of becoming + +differentiated. So, here we have an asymmetric cell + +division on the part of this stem cell up here. + + We'll prove later on that these two + +cells are genetically identical, but clearly they're reading out + +their genes in quite different ways. This cell is absolutely the same as + +the mother cell. This cell has already committed + +itself. It's made the commitment to differentiate in one + +or another lineage. And another way of noting this + +graphically is the following. We can draw a picture like this, + +as we did before, and here we'll have a second arrow that goes around + +like this. It loops around back on itself, and that implies the whole + +program of self-renewal. Now, the whole concept of + +self-renewal is a simple one. If a stem cell can self-renew, + +that implies that the process of growth and division does not deplete + +the pool of stem cells in the body or in a particular tissue. + +So, let's imagine what we're looking at here. Here we have a stem cell. + +It has one cell that is just like Mom. This is a differentiated cell. + +Once again, you can have a growth and division. This is, + +once again, a cell like Mom. This is a differentiated cell and + +so forth. And what you notice here in this arrangement is that the stem + +cells perpetuate themselves. They are self-renewing. + +And, as a consequence, the pool of stem cells is never depleted in the + +best of all possible worlds. It turns out that in most of the + +tissues of our body there is self-renewing stem cells going on, + +because most of the differentiated cells in our body have a finite + +lifetime. Not all of them but most of them. And when I say finite, + +I mean it can be measured in a matter of days or weeks + +or months. In the case of the brain, + +things turnover very slowly. Even in the case of our bones, + +our bones actually turn over roughly once, 10% a year. + +10% of the matter in the bone is actually turnover in every year. + +So, almost all tissues in the body are in a process of continuing + +self-renewal and repair. And that self-renewal and repair is + +maintained by this stem cell compartment, as is indicated here. + +This has certain kinds of great advantages, and one of the + +advantages is indicated by the following. Let's imagine that we + +draw a picture, just for the sake of argument, + +of one of the most highly proliferative tissues in the body, + +which is to say the lining of the colon or of the duodenum. + +So, here we have, let me draw it slightly differently, + +here's the way the lining of the small intestine looks like. + +Out here are the contents of the small intestine. + + So, let's say here is the lumen of + +the small intestine. And here we have, protruding into + +the lumen, when I talk about a lumen I'm talking about the bore or the + +channel of a cylindrical or tube like organism. + +So, here is the lumen of the small intestine. Here are these + +fingerlike projections, they're called villi, that protrude + +into the lumen of the small intestine. And down here at the + +bottom of this are these cavities that are called crypts, + +C-R-Y-P-T-S. These are the crypts. Now, what's important to realize is + +that what goes through our intestines is not that pleasant. + +It's pretty corrosive stuff. I probably told you this already, + +more bacteria living in there than we have in our entire cells in our + +entire body. There are all kinds of digestive juices. + +And so the cells out here at the tips of these villi are continually + +exposed to all kinds of corrosive material, including the junk that we + +eat everyday which is flowing by like this. And this indicates how + +critically important it is that we have self-renewal, + +because the cells out here, being continually exposed to the + +most corrosive kinds of influences, are rapidly damages. + +And, therefore, the cells out here have a lifetime + +of only three or four days and are then induced to jump off the end of + +a gangplank and commit apoptosis. So, the cells at the tip of the + +villis are continually jumping off and dying. And what's happening is + +that down here in the bottom of the crypts we have stem cells. + + The stem cells are continually + +producing progeny that have committed themselves to + +differentiate. And the progeny, + +as you might guess from what I've just said, are continually migrating + +up the sides of the villis up to the end here. And this whole migration + +takes four or five days, and by the time they get to the tip + +and have stuck their heads into the contents of the lumen of the + +intestine for that period of three or four days. + +Finally, they're eliminated and they jump off into the abyss. + +So, there's a continuing action going on here. + +The stem cells are continually dividing. And what advantages does + +this have for us? Well, it means that cells that are + +damaged are not allowed to hang around for a very long period of + +time, i.e., cells up here in the top that are exposed to, + +for example, potential mutagenic influences are rapidly eliminated. + +Why is that good? Because the mutagenic influences up here could + +well create a mutant cell that, in principle, is able to become + +cancerous. And the body says, + +well, I don't mind if that happens because these cells up here are + +going to be eliminated anyhow. They're going to be pushed off the + +end of the diving board or the gangplank into the abyss, + +so they are continually undergoing apoptosis, not as a pathological + +process. As a normal process. They're continually being pushed + +out here. And what that means is that the + +cells down here, in the bottom of the crypt, + +are actually physically protected from the contents of the lumen of + +the small intestine because some of the cells in this crypt are + +continually secreting a kind of mucus in this area right here. + +It's called a mucin. And this mucin here creates a physical + +barrier, so the cells that are in the bottom of the crypt are never + +directly exposed to the contents of what's flowing by in the + +small intestine. And that is extremely important + +because, in fact, it means that these cells down here + +are shielded from the mutagenic influences of what might be present + +in the lumen of the small intestine. In theory, one might be able to + +evolve cells that don't mind being up here in the lumen of the small + +intestine. But, in fact, that's never been possible. + +That is to say evolution has just said, well, we can't really evolve + +cells that are resistant to the corrosive influences of what happens + +in the small intestine. And, therefore, + +we're just going to use these cells for a very short period of time and + +then get rid of them. What that also means is the + +following. The stem cells down here stay within that crypt. + +They don't migrate out. They stay there in that shielded + +site. And, in fact, if you think all this through, + +it's very important to protect these cells from becoming mutated because + +if they do become mutated they could become the precursors + +of cancer cells. If these cells become mutated out + +here, it doesn't matter because they're going to die anyhow. + +And so, we now have the following kind of dynamic. + +Here's the stem cell. I'll draw it again. I'll just + +abbreviate it stem cell. And one of the ways by which we + +want to preserve the genetic integrity of the stem cell is to + +insure that the stem cell divides as infrequently as possible. Why? + +Because the whole process of cell division is itself a fallible + +process. Every time a cell grows and divides, as we learned from the + +cell cycle, there's the possibility of different kinds of genetic + +disasters happening in which case we might end up with a mutant stem cell. + +And that mutant stem cell could in turn, I argue, + +become involved in creating a tumor. So, we have the following kind of + +arrangement. Here is the stem cell. It has one daughter that has + +committed herself to differentiate and the other that remains + +a stem cell. Well, you're saying this enormous + +amount of activity must involve a frenetic amount of cell division on + +the part of the stem cell. But that's not really the way it + +happens because this daughter cell undergoes a series of exponential + +divisions, I can't fit them all on the blackboard here, + +and might even yield a hundred descendents which then become the + +ultimate differentiated cell. This daughter cell becomes one stem + +cell. This daughter cell undergoes these exponential expansions in a + +process of creating a population of cells that are called transit + +amplifying cells. + +And at the bottom of this hierarchy, I can't draw all hundred, there may + +be a hundred of these cells, ten to the second, and these cells + +then differentiate. + +At the bottom, the hundred cells at the bottom, + +they go into the last stage of differentiation. + +They become the specialized cells that line the tips of the villis. + +Now, why is there this arrangement? Well, look at what the advantage of + +it is. The stem cell has just divided once, but this cell has + +generated a hundred progeny. And that means that the stem cell + +doesn't have to divide that often. The stem cell can divide once. + +Every time the villis needs a hundred new cells it needs to divide + +only once. And, therefore, the stem cell actually is + +one of the most slowly dividing cells in the entire gut because it + +only needs to divide episodically. Each time it divides it generates + +this enormous array of progeny. One other aspect of differentiation, + +and when I talk about differentiation here, + +I mean the acquisition by these cells of all of the traits they need + +to line the colon. When I talk about differentiation in + +the skin, I talk about the ability, the acquisition of the cells of + +becoming fully competent, fully functional skin cells. + +The same thing with neurons in the brain. And one additional important + +concept I'd like to introduce is that when cells differentiate they + +often become post-mitotic. Post-mitotic means that these cells + +give up the option of ever dividing again. In other words, + +as they acquire more and more specialized traits they say to + +themselves now I'm a nerve cell, now I'm a cell in the tip of villis + +in the intestine, now I'm a muscle cell, + +I'm not going to divide ever again. And this is generally true. The + +most differentiated cells in the body in general end up losing the + +ability to divide. They become post-mitotic. + +They've exited irreversibly from the cell cycle. + +They can't go back in. As you recall, we talked about + +cells going from G0 back into the active G1 phase of the cell cycle. + +That's a reversible exit from the cell cycle. Post-mitotic cells are + +irreversibly committed never to divide again. And, + +again, that holds true for almost all cells of the body. + +One exception to that is, interesting enough, in the liver. + +Because what you can do with a mouse, or even with a human, + +is you can cut away a couple lobes of the liver, major league surgery. + +And when you do that, what happens is that all the remaining cells of + +the liver, and these remaining cells in the liver are called hepatocytes, + +these hepatocytes, which until that time had been highly specialized + +differentiated cells in the liver, many of them divide, they double + +again. And in short order one ends up with + +a liver which is exactly the same size as one had before. + +And that's actually quite remarkable because there are very + +few organs in the adult human being where that will happen. + +There is, by the way, an interesting puzzle here, + +and that is the following. Let's say you cut away half the + +liver and many of the hepatocytes, which were already highly + +differentiated, began to divide again, + +so they were not serious post-mitotic cells, + +they could reenter into proliferative phase. + +How do these cells know when to stop dividing so that they end up + +regenerating a liver of exactly the right size? People have been + +looking at that for 30 or 40 years. Nobody has any idea why. Why + +doesn't the liver when all these cells divide become one and a half + +times the size of its former diameter or half the size? + +Nobody really understands that. In any case, I just want to + +indicate that there is this dynamic between differentiation and + +proliferative capacity, one in opposition to the other. + +Well, how much hematopoiesis is taking place here in our bone marrow, + +for example, where a lot of this takes place? So, + +here are just some interesting numbers. There are roughly five + +times ten to the twelfth red blood cells -- + + -- per liter of blood. + +And red blood cells, you may recall, are called erythrocytes. + +Remember, it's never good to use a short Anglo-Saxon term if you can + +use a long complicated Greek one. And each of these red blood cells + +has roughly a lifetime of 120 days. That is to say after it's made it + +sits around in the blood for roughly 120 days. + +It gets warn out. It gets gobbled up by the cells in + +the spleen. Much of the contents are recycled. The pigment in our + +stool comes from the recycling of the hemoglobin, + +the iron and the hemoglobin, and we're constantly renewing that. + +Well, the average human being, let's say, has roughly ten liters of + +blood per person. + +And if you put all those numbers together, I once calculated that the + +number of red blood cells that is being generated in the body is + +roughly ten to the tenth per hour. And you can go through the + +calculations if you want, it is fine with me, but take my word + +for it's roughly what's going on there. Ten to the tenth per hour. + +Each time I utter a word there's probably, I don't know, + +ten to the seventh new red blood cells being made in my bone marrow. + +So, this is not minor league proliferation. + +Now we begin to understand why there are ten to the sixteenth cell + +divisions in the lifetime of a human being. In fact, + +a great majority of them, to be fair, are occurring in the + +bone marrow and in the intestine. And if you have an individual who's + +being exposed to certain kinds of chemotherapy, chemotherapy, + +as you may know, is very toxic for dividing cells, + +and the side effect toxicity of anticancer chemotherapy is largely + +felt, first of all, in the bone marrow where individuals + +tend to become anemic. Anemic means they have lower than + +normal numbers of red blood cells and also they lose a lot of the + +lining of the intestine which creates all kinds of also + +unpleasantness as well. So, we're not talking about + +something that happens on rare occasion in the life + +an individual. This is a staggering amount of + +mitosis that's happening every day of our lives. Let's go back for a + +moment to this diagram here and realize that when I'm talking about + +erythrocytes, I'm only talking about one of the branches of this + +multi-branch pathway. And here we see some other + +interesting aspects of what's going on here, and I'll give you some + +proofs very shortly that this actually is what it says it is. + +It actually is organized this way. The pluripotent stem cell is capable + +of self-renewal, and it can spew off daughters which + +actually can go in two different directions. Its daughter may decide + +that it might become the precursor of the lymphoid cells in the blood + +or it might commit itself to becoming a myeloid precursor. + +So, that's already the beginning of a bifurcation. + +These cells are not yet differentiated. + +They've just made the commitment that each of them can, + +in principle, become the ancestor of highly differentiated cells. + +And these cells, we can imagine, are transient + +amplifying cells in the sense that even though they're committed to + +create progeny of one sort or another they themselves are not yet + +fully differentiated. Keep in mind in the context of the + +crypt these transient amplifying cells are on the way to becoming + +fully differentiated, but only at the bottom of this + +exponential expansion of cells do we have cells that are fully entered + +into a highly differentiated state. Here we see that these two cells are + +also stem cells in the sense that the can self-renew. + +They have a limited self-renewal capacity, but they can self-renew. + +And then they begin to create progeny which themselves can + +undertake several distinct alternative differentiation paths. + +So, the lymphoid cells can become the progenitors of the T lymphocytes + +and the B lymphocytes. And, in fact, if you recall our + +discussion of immunology, there's actually several different + +kinds of T lymphocytes and B lymphocytes. So, + +this pathway has further radiations further down. Here, + +alternatively, these are the myeloid cells. And myeloid refers to the + +bone marrow. And the myeloid cells can become these kinds of cells up + +here, eosinophils and basophils and neutrophils and monocytes, + +and this class of cells is largely involved in gobbling up infectious + +agents and as agents which are able to defend us largely against + +bacterial infections. Here's the macrophage. + +We talked about the macrophage. Remember the macrophage was this + +glutton, this pig which wandered around our tissues and gobbled up + +whatever kind of material it could find and presented it to the immune + +system. And here are several other of the lineages. + +Here is a megakaryocytic and this is an erythrocyte. + +What's a megakariocyte? Well, it has a very large nucleus. + +That's what the term implies. And what happens to the + +megakariocyte is it buds off little chunks of cytoplasm lacking nuclei. + +And these little chunks of cytoplasm become the blood platelets. + +Blood platelets lack nuclei. They're enucleate because they're + +just little bags of material which are sent out into the circulation. + +And, as we said also earlier in the semester, once the platelets are in + +the circulation they are there ready to help should there be any kind of + +wounding, any kind of hemorrhaging occurring. + +And the platelets can release upon being activated in a site of wound + +coagulation factors and growth factors for the regeneration and + +reconstruction of wound sites. And, finally, here are our friends + +the erythrocytes. So, here we have a whole sequence + +of different kinds of differentiation commitments which + +are going on at an enormous rate. How do we know that there actually + +is a pluripotent stem cell? What evidence can I provide you that + +this actually exists or it's just a figment of my normally florid + +imagination? And the most direct demonstration of that is, + +in fact, the use of bone marrow transplantation. + +So, when we talk about a bone marrow transplantation, + +or BMT as it's called in the trade, -- + + -- one can do a relatively simple + +experiment. You can take a mouse or even a human and you can irradiate + +it rather heavily. And if you irradiate it under the + +right conditions you'll actually be able to kill off all the cells in + +the bone marrow without killing off the mouse or the human being. + +In fact, there are drugs you can also use in human beings to + +eliminate virtually all the cells in the bone marrow. + +And then what you can do is you can take bone marrow from another + +organism, from another mouse or another human, + +and you inject it into the blood of the irradiated mouse or human. + +And the bone marrow cells, many of them will home to the bone + +marrow. In other words, you're injecting the bone marrow + +cells in the general circulation, but within a couple hours they'll + +all end up in the bone marrow, in the space in the middle of the + +bone because there are many kinds of cells which have this homing + +capacity. They go to the right place in the body. + +So, they can home. The injected cells can home to bone + +marrow. And then, if things are going well, + +these injected bone marrow cells will begin to proliferate and they + +will ultimately regenerate this entire cascade of differentiation + +decisions, as is indicated here. And, therefore, that individual or + +that mouse will actually be rescued. Because in the absence of such a + +rescue an individual will rapidly die. + +You can't live for very long in the absence of an active bone marrow + +because these cells here are rapidly depleted. They turn over with some + +speed. The red blood cells hang around for 120 days we said and, + +therefore, you don't need to make them immediately because there's a + +whole bunch around that have a rather slow turnover. + +But the platelets only have a lifetime of several days before + +they're lost, they're turned over. And if you don't have platelets + +you're in very bad shape because you start hemorrhaging all over the body + +because, remember, the platelets are there to stop up + +all the holes in the dike to prevent bleeding. + +These cells here are very important, the eosinophils, basophils, + +neutrophils, and even macrophages in preventing bacterial infections. + +And in the absence of having these on site one can readily succumb to + +overwhelming infections. Keep in mind that the reason why + +we're not constantly dying from bacterial infections is not because + +each of us takes an antibiotic pill every day, it's because these cells + +are on watch to kill any bacteria that happen to be in the wrong place + +in the body outside of the lumen of the gut. + +And consequently the question is always can one rescue a mouse or a + +human rapidly enough? Can one replace its bone marrow + +rapidly enough so that this disaster from losing all ones bone marrow + +doesn't overtake one and the organism dies before the bone marrow + +has had a chance to become reconstituted, regenerated, + +reconstructed. Still how do we know from all this + +that, in fact, there is a pluripotent stem cell? + +If you listened to everything I said correctly you could say, + +well, there isn't such a thing as a pluripotent stem cell. + +There are these other kinds of stem cells, this one and this one, + +or these might all be stem cells. And when I'm injecting the bone + +marrow of a donor animal into the recipient, I'm injecting a whole + +mixture of different kinds of stem cells here each of which then goes + +on and populates a specialized compartment in the bone marrow + +or in the blood. So how do we know there's one + +pluripotent stem cell? One way to prove this is the + +following. Let's say we take the bone marrow from the donor, + +that is the bone marrow that we're going to inject into the irradiated + +recipient, and we irradiate that bone marrow very lightly, + +not to kill the bone marrow cells but to introduce random chromosomal + +breaks, a very small number of random chromosomal breaks in the + +donor bone marrow. So, the purpose now of irradiation + +is quite different from what I said before. Before we wanted to give a + +heavy dose of radiation to wipe out the recipient bone marrow. + +Now we're going to just give a wee bit of radiation to the donor bone + +marrow. What's the purpose of that? The purpose of that small amount of + +radiation is to create chromosomal abnormalities. + +So, for example, if here are two homologous + +chromosomes in the donor cells. Since the radiation, the very weak + +dose of radiation is acting randomly it will create all kinds of + +abnormalities including, for example, a very specific + +chromosomal translocation so that what might happen after this is that + +a whole chunk of this chromosome is translocated over to this chromosome + +here. This is called a chromosomal translocation. + + And now here's the donor, + +these are donor bone marrow cells. And keep in mind that every donor + +bone marrow cell that gets a little bit of this radiation will get its + +own very specific randomly occurring translocation just because radiation + +is able to break chromosomes and then they will rejoin in + +unpredictable ways. What that means is that if we take + +the donor bone marrow and irradiate it very lightly so that we don't + +kill the cells but we do induce these translocations, + +one donor cell will have this translocation and another donor cell + +over here will have a totally different translocation from a + +different chromosome also induced randomly by these stochastic + +processes. So the karyotype which is the whole + +array of chromosomes of a cell, which can be viewed at the metaphase + +of mitosis when all the chromosomes condense, the karyotype of each of + +these donor bone marrow cells will be messed up slightly. + +And it will have recognizable abnormalities, + +but they're all different, one after the other. And after + +we've done this, after we've marked millions of bone + +marrow cells in the donor with these random low-dose radiations, + +we can then inject a small number of bone marrow cells into + +the recipient. And what we can sometimes find on + +occasion is if we look at the recipient after that recipient has + +been rescued, i. ., after the donor bone marrow has + +established itself within the recipient, is that the donor bone + +marrow is established in the recipient and populates all of these + +different lineages. And if we're able to look at the + +karyotype of these different kinds of cells in the recipient organism, + +we can find that in some mice all of these cells have the same very + +peculiar translocation. They have either this one or this + +one or they have yet a third translocation, + +any one of a whole series of randomly occurring mutations, + +a very peculiar idiosyncratic unusual translocation induced by the + +low-dose radiation. They all have it. + +The T cells and the B cells and the monocytes and the basophiles, + +they all have exactly the same translocation. + +Obviously, we can't do that experiment with the platelets. + +Why? Because they don't have nuclei. And we can't do that with + +the erythrocytes either, the red blood cells. Why can't we + +do that? Because in mammals, when the red blood cells are formed, + +the nuclei are spit out. Our red blood cells don't have nuclei in + +them anymore. They've become enucleate or, to put it another way, + +they have been enucleated. That is to say they've been deprived + +of their nuclei. Why? Because they're post-mitotic. + +Obviously, a cell which lacks nuclei is by definition post-mitotic. + +And our cells don't really need, red blood cells don't need nuclei. + +We know that ancestral organisms, for instance chickens, + +their red blood cells are nucleated, but our red blood cells are not + +because they're just not necessary. + +How is translocation different from crossing over? + +Crossing over occurs between two homologous chromosomes. + +So if we have a chromosome here, here's chromosome 13 and here's + +another chromosome 13, they're both chromosomes 13. + +This one came from Ma. This one came from Pa. All right? + +Each of us has a pair of homologous chromosomes. + +Here's the maternal one. Here's the paternal one. + +When we talk about crossing over we're talking about a process of + +homologous recombination. + +And when that happens we have a situation like this. + +This chunk is exchanged with this chunk over here. + +It's an equal exchange, absolutely equal down to the + +nucleotide, so that after this flipping has occurred we have two + +fully intact chromosomes. It's just that both of these + +chromosomes are fully normal. It's just that there's been a + +switching, an exchange between the two homologous chromosomes, + +the two paired chromosomes 13. When we talk about translocation + +there a chunk of chromosome 15 can go onto chromosome 7 or a chunk of + +chromosome 2 can go on chromosome 8. It's totally random, it's + +non-homologous, and it creates aberrant chromosomes. + +Neither of these recombined chromosomes is abnormal. + +It's just changed it allelic configuration. + +So, it's an important distinction. And the fact is you can pick out + +these translocated chromosomes because one even has specific dyes + +that can be able to tell you which chromosome this came from and which + +chromosome this came from. So, there is a profound difference. + +Translocations are, invariably, pathologic. When I say pathologic, + +I mean they're really sick. They're not the proper course of + +things that happens in a healthy cell. The fact, + +the very fact that we're able to generate an entire array of cells in + +the blood indicated, by necessity, that if all these + +cells have the same chromosomal translocation that they descend from + +a donor cell that originally was lightly irradiated and happened to + +receive that translocation. If we never get this array of common + +translocations in all the cells in a bone marrow recipient then we can't + +prove this, but the fact is this has been proven time and again over the + +years. And this indicates to us that this cell which is genetically + +slightly altered can, therefore, generate all these other + +cells in the body. Again, keep in mind that the + +irradiation of the donor marrow is simply to create these chromosomal + +markings. They're not necessarily good for the organism, + +but they don't compromise the viability of the cell. + +They just reshuffle the chromosomal structure. Now, + +in principle the levels of each one of these kinds of end-stage cells + +need to be carefully regulated. And, by the way, let me just note + +here, you see the T cells have the arrow going back on themselves, + +as do the B cells. That indicates that they have not become + +post-mitotic. Remember we talked about these embraces between helper + +T cells and B cells where they're walking down the allies and they get + +excited and they start multiplying? The fact that the T cells and the B + +cells are able to proliferate in response to certain antigenic + +stimuli implies that they're not post-mitotic. They still have the + +ability to proliferate, and that retained ability to + +proliferate like that of hepatocytes is indicated by these arrows that + +are looping back on themselves. Conversely, these cells are all + +essentially, as I've said before, post-mitotic. So how do we insure + +that's there proper concentrations of all of these different + +cells in the blood? And the fact is the concentrations + +of many of these cells in the blood are maintained to concentrations of + +plus or minus 10%. And this is, itself, + +a stunning testimonial to the successes of human physiology. + +We're talking here about a process which is sometimes called + +homeostasis. Homeostasis means that somehow there is a balance, + +an equilibrium that is achieved, and that there aren't profound + +fluctuations so that we always have roughly the equal level of red blood + +cells, a proper level of lymphocytes in our blood. + +And I want to get into the homeostasis which results in the + +formation of red blood cells, the RBCs, the erythrocytes in the + +blood. In fact, it happens to be the case that the + +red blood cells are one of the cell types that could actually vary quite + +profoundly in response to environment. + +To the extent that lymphocytes change, they go up and down, + +that might be due in response to an infection. So, + +if we have a serious bacterial infection we might have increased in + +the lymphocytes in the blood that have been mobilized in order to + +attack the infecting bacteria. But what about the RBCs? What + +about the red blood cells? What causes them to change? + +Well, if you move from here to Denver, Colorado or you go up skiing + +in the Rockies, you're going up to ten or twelve + +thousand feet. And within a matter of three or four + +days the concentration of your red blood cells increases very + +substantially. Why? Because obviously the oxygen + +tension at high altitude is down. And in order that your peripheral + +tissues become adequately oxygenated, the oxygen carrying capacity of the + +blood must be increased. And the way that is increased is in + +part to increase the concentration of red blood cells. + +So how does that happen? How is it possible that we can + +rapidly modulate the concentration of red blood cells? + +And the way we can do that is in part through a hormone called + +erythropoietin, EPO. We're going to talk about + +erythropoietin at the beginning of the lecture next time, + +but the homeostasis which maintains the appropriate number of red blood + +cells in our circulation is dictated in no small part by the levels of + +EPO that are in their blood. To anticipate some of the things + +we're going to say next time, when you are in a low-oxygen + +environment the levels of erythropoietin shoot up. + +And when they shoot up they insure that there is shortly thereafter a + +rapid increase in the level of circulating red blood cells which in + +turn enables the oxygen coming into your lungs to be transported more + +efficiently, more effectively into the peripheral tissues. + +You've heard about athletes perhaps who are able to dope themselves with + +erythropoietin. This is a rather devious strategy + +because it means that if they do so, they inject themselves with a little + +erythropoietin, the oxygen carrying capacity of + +their blood is temporarily increased and as a consequence they might be + +able to run further or jump higher. This, by the way, + +has its dangers. Because if you're injecting erythropoietin not in + +response to certain physiologic signals but just because you want to + +win a marathon or something, you're violating the normal + +physiologic mechanisms in the body which very carefully control the + +levels of erythropoietin. And if you inject too much + +erythropoietin you get in a very bad situation because the bone marrow + +makes more and more red blood cells. And then what happens? You start + +clotting up everywhere all over the body, and this isn't good. + +In fact, you can die. So this is not a warning against + +erythropoietin in the way that I warned you against cigarettes. + +This is just to tell you these kinds of drugs, + +or these kinds of growth factors, which they are, are maintained at + +very precise levels as we'll discuss in more detail next time. + +See you on Wednesday. \ No newline at end of file diff --git a/OIis_b2bSVo.txt b/OIis_b2bSVo.txt new file mode 100644 index 0000000000000000000000000000000000000000..073351909454977313c9872389da9f84aad62639 --- /dev/null +++ b/OIis_b2bSVo.txt @@ -0,0 +1,3827 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high-quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: So we want to +discuss line shifts and line + +broadening. + +And I assume you'll +remember that last class we + +did some brainstorming and came +up with quite a number of line + +broadening and line shifts +mechanism, temporal lifetime + +broadening, motional +broadening, external field + +broadening, +collisional broadening. + +And as I indicated at +the end of last class, + +those different +broadening mechanism + +have much more in common +than you may think. + +And you will see that they +have much more in common + +when we look at it from +the fundamental perspective + +of coherence. + +Any line broadening +mechanism comes + +because the atom experience, the +environment and the drive field + +as a coherent source only +for limited coherence time. + +So the concept of +the coherence time + +will actually provide +a common denominator + +for all those line +broadening mechanisms. + +However, before I +present to you this kind + +of correlation function approach +to what's line broadening, + +I think it's really +important that we + +go through some simple cases. + +I always want you to learn +phenomena in the simplest + +possible manifestation, +in a situation where + +without any math you +see what's going on. + +And what I particularly +love is if there + +is an analytic solution +where everything + +is sort of transparent here. + +So therefore, before we discuss +in a comprehensive way line + +shifts and line +broadening, I want + +to go through simple cases. + +Now, I decided for this class +that most of today's lecture + +uses pre-written slides +because those cases are + +so simple that I would be +almost afraid I would bore you + +if I would write it out. + +Because if you look at +this equation in one second + +you get it, and it takes me +10 or 20 seconds to write it. + +On the other hand, +I would sort of + +give the responsibility to you. + +If I'm flooding you with +too much information, + +ask me questions, +slow me down, or say, + +can you please go over that? + +So I don't want +to obscure things + +by going through them faster. + +I also looked a +little bit forward + +to the end of the course. + +We are about OK with the +pace of the course, or maybe + +one hour behind. + +And so in order to make room for +discussions of superradiance, + +which I would like to have +with you in a couple of weeks, + +I thought I can save +half an hour here + +by going over that material +a little bit faster. + +But these are really +just illustrations + +of line broadening. + +And you should actually +know most of them already. + +So the first cases are +actually leading you up + +to the Ramsey +resonance, to the method + +of separated oscillatory fields, +which is really absolutely + +important for high +resolution spectroscopy. + +But before we can fully +understand the Ramsey + +resonance, we have to +understand the Rabi resonance. + +So what I've written +down here is for you + +just the well-known formula +for Rabi oscillations. + +And if you now simply assume +we let the atoms interact + +with the field by a fixed +amount time tau in such a way + +that we have a pi pulse, +then this probability + +as a function of detuning +becomes a line shape. + +And this line shape +is plotted here. + +It has a full width +of half maximum, + +which is approximately 1/tau. + +And this is-- you can +regard it as the Fourier + +limit of finite interaction +time broadening. + +We are observing the +atoms for time tau + +and the line which is +on the order of 1/tau. + +But we also know +from the Rabi formula + +that we have these side lobes, +so we see some oscillatory line + +shape. + +OK, now, with the +advent of trapped atoms, + +you can often have +the situation that you + +have an ensemble +of trapped atoms. + +You flash on your drive field +for fixed amount time tau. + +At least for most of last +century, this was not possible. + +You had atomic beams. + +And in an atomic +beam, what is fixed + +is not the interaction time tau +but the interaction length l. + +And then due to the +velocity distribution, + +different velocity +groups of atoms + +interact a different +amount of time with that. + +So for conceptional reasons but +also for the historic context, + +you should sort of have an idea +what the Rabi apparatus is. + +I may have mentioned +it, but I regard Rabi + +as sort of one of my +ancestors in my family tree + +because Rabi was the PhD +advisor of Norman Ramsey, who + +was the PhD advisor +of Dan Kleppner, who + +was the PhD advisor +of Dave Pritchard. + +And Dave Pritchard was +my postdoctoral mentor. + +So I'm really talking here +about my scientific great-great + +grandfather. + +Anyway, so the famous Rabi +apparatus is the following. + +You use one Stern-Gerlach magnet +to prepare a certain hyperfine + +state. + +Then you have the +interaction region, + +and this is what +we are focusing on. + +And then later, if a spin +flip has taken place, + +you can figure that +out by running it + +through a +Stern-Gerlach analyzer. + +So it's this ABC +region, and we are + +talking about this middle region +where we have an interaction + +time which is now given by the +length divided by the velocity. + +So what we have to +do is-- well, that's + +why I'm saying +it's simple cases, + +and I hope I can +go fast-- you just + +take the previous result +with a Rabi probability + +and convolute it with a +velocity distribution. + +So when we do that, +we find two effects. + +One is, well, due to the +velocity distribution, + +the line width becomes +a factor of 2 broader, + +but it's still +proportional to something + +on the order of unity divided +by the interaction time. + +And because the +different velocity groups + +have a different +kind of oscillations + +as a function of detuning, +the oscillatory behavior + +now disappears because +it becomes averaged out + +[? of ?] the velocity groups. + +OK so this is the Rabi +method or the Rabi resonance, + +where we have one interaction +pulse or one interaction + +time for an atom. + +The next method is now +what was introduced + +by Norman Ramsey as the method +of separate oscillatory fields. + +And for that and +other contributions + +he was awarded the +Nobel Prize in 1990. + +And the difference +is the following. + +In the Rabi method, we +let the atoms interact + +with the drive field for fixed +lengths l or fixed time tau. + +But in the Ramsey +method, we interrogate, + +we drive the atoms +with two short pulses, + +which are separated. + +So in the simplest +case, we do 2 pi + +over 2 pulses +separated by a time t. + +And now, if you have two +pulses, everything is coherent. + +The two pulses can +interfere constructively + +or destructively. + +So what you would +expect is that-- I + +want to give you two pictures. + +One is the Bloch sphere +picture, but let's just sort + +of play with the +concept of interference. + +If this is zero +detuning, the two pulses + +are separated by a time t. + +And therefore, you +would now observe, + +as a function of detuning, +Ramsey fringes and oscillatory + +behavior, which +has a spacing which + +is 2 pi over the +time between pulses. + +The envelope of +the whole fringes + +is related to the short +time of the duration. + +It's like a double +slit experiment. + +You know, each slit is +broad, and the width here + +is given by 1 over the short +time delta t of the pulse. + +But then the two +slits interfere. + +And the interference +pattern is the distance + +between the slits, which +now in the temporal domain + +is the time capital +T between them. + +So these are sort of +typical Ramsey fringes. + +And now, if you would +average over a broad velocity + +distribution, then +you would kind of + +average-- you would maybe +see one or two side lobes, + +but the other fringes +are averaged out. + +So the central peak, +the resolution is again + +on the order of 1/T. +It's the total time + +of the experiment, +which is setting + +the ultimate resolution, +similar to the Rabi resonance. + +So this uses the +picture of interference + +between two pulses. + +But I also want to +sort of give you + +the Bloch sphere picture, +because it's beautiful. + +For that I need a +little bit of room. + +So an atom enters the +first Ramsey region, + +and it has to spin down. + +You do a pi/2 pulse, +which is at 90 degrees. + +And now what happens is +there is a field-free region + +between the two pulses, +so the atom is now + +precessing at its +resonance frequency. + +OK, but the synthesizer which +is attached to your coils + +is also sort of precessing +at this frequency. + +And when you add zero detuning, +the synthesizer and the atoms + +are aligned again. + +And the second pi/2 pulse +is now flipping the atoms, + +and you've 100% excitation. + +And this is what you see here. + +But now let's assume you +are slightly detuned. + +Then the atom is precessing, +and your synthesizer + +is precessing at a slightly +different frequency. + +And now in the second +region, the frequency + +of the synthesizer +may be different + +with-- the phase +of the synthesizer + +is 180 degree different +from the phase of the atom. + +And then instead of flipping +the atoms up and getting 100% + +in the up state, the +atom is now flipped down. + +And this explains +the first minimum. + +So you should really see +that in this long region, + +nothing happens. + +But you accrue a relative +phase between the synthesizer + +and the atom, which oscillates +at its resonance frequency. + +So based on this model, +you could work out + +mathematically every aspect of +those fringes I've shown you. + +But I decided to take the +equations out of the lecture + +and just present you with +this physical picture. + +Questions? + +AUDIENCE: If you have a +velocity distribution, + +would the points of +those minimums change + +or is it still this-- + +PROFESSOR: Well, good question. + +The spacing is the time T. +But if you have a velocity + +distribution, let's say a +velocity distribution which + +has a width delta v over v +of 30%, what we have kept + +fixed in the beam +experiment are the lengths, + +the interaction lengths. + +So time is length over velocity. + +So therefore, when +the velocity changes + +by plus/minus 30% in +your atomic beam-- + +unless you take a +supersonic beam with a very + +narrow velocity +distribution-- then that + +means one velocity class +has this set of fringes. + +The other velocity class has +this similar set of fringes, + +but like in a +harmonica, everything + +is now spread out by 30%. + +And if you have now 30% +velocity resolution, + +that means you may be able +to see two or three fringes. + +But the central fringe is sort +of like a white light fringe. + +There is no relative +phase shift. + +And therefore all the +different velocity classes + +will have a maximum +at zero detuning. + +So in the extreme limit +of a very broad velocity + +distribution, the only +feature which survives + +is the central fringe. + +But this is where you obtain +your spectroscopic information + +from. + +Will? + +AUDIENCE: You have explained +this Bloch sphere picture + +assuming unbroken coherence +between your synthesizer + +and the field-free +evolution of your atom? + +PROFESSOR: Yes. + +AUDIENCE: Is it equivalent +to if you wrote down the time + +evolution operator, you +would say that there's 0 Rabi + +frequency, but no +detuning in your field? + +PROFESSOR: Yes. + +AUDIENCE: So what if +I-- is this necessary, + +to have this unbroken coherence +if I unplug my synthesizer + +and plug in a new +one [INAUDIBLE]-- + +PROFESSOR: Yes, you +can do spectroscopy + +with a resolution +delta mu, which is 1/T, + +only if you have a synthesizer +which has a frequency + +stability which is +better than 1/T. + +AUDIENCE: OK. + +PROFESSOR: Otherwise, we've +done this a little bit + +when we talk narrowband +and broadband. + +When we talked about +narrowband and broadband cases, + +you are always limited +in your resolution + +by whatever is broader. + +Here I'm discussing about the +width of the atomic system, + +assuming a perfect synthesizer. + +But then in essence, you +should convolute this result + +with the spectral distribution +of your synthesizer. + +And then if the synthesizer +has a resolution which + +is worse than that, you would +actually blur out the fringes + +through the convolution +with the frequency + +spectrum of the synthesizer. + +[INAUDIBLE]? + +AUDIENCE: So that also means +if you add a [INAUDIBLE] + +to the second coil, [INAUDIBLE] +just like if you had + +[INAUDIBLE] to one of the-- + +PROFESSOR: Yes, actually, +if you would add a pi phase + +shift to the second +coil, then the minimum-- + +the central feature would +not be maximum or minimal. + +Yes. + +And that's why when you have +atomic clocks with a beam, + +the question of +distributed phase + +shifts within the microwave +cavity play a big role. + +And this is related +to are the two Ramsey + +zones really at the +same phase or not? + +So that's an important +issue for ultimately making + +resolution spectroscopy. + +OK. + +Since-- OK. + +So we've discussed +two methods now, + +the Ramsey method +versus the Rabi method. + +And let me discuss advantages +or disadvantages of the method. + +So if you're an atomic +physicist and you + +have to give advice +to your friends + +whether they should use the +Ramsey or the Rabi method, + +these are your talking points. + +So one point is that I said the +central feature of the Ramsey + +fringes is 1/T. The +Rabi feature is 1/T, + +so we are both limited +by time resolution, + +because this is a Fourier limit. + +But if you work out +the details, you + +find that the Ramsey fringe +is about 2 times narrower + +than the Rabi resonance. + +Just how things work +out mathematically-- + +I can't give you any +real deeper insight why. + +It just works out to be a factor +of 2 narrower than the Rabi + +resonance. + +There's one important aspect, +and this is the following. + +When you accrue the +spectroscopic information, + +you compare-- I hope you +remember my demonstration-- you + +compare the atomic oscillator +to the synthesizer, + +but you're not interacting +with each other. + +So therefore you don't +have any power broadening. + +You're comparing the free +evolution of the atom + +with the propagating +phase in your synthesizer. + +And therefore, your Rabi signal +has no power broadening at all. + +And that means that, +however, the Rabi signal, + +at least for small detunings +which are smaller than the Rabi + +frequency, will always depend +quadratically on delta. + +Remember, generalized +Rabi frequency, + +you add or make a Rabi +squared and detuning + +squared in quadrature. + +So therefore you will +always get effects + +for small detunings +which are quadratic, + +whereas the way how you set +up the Ramsey experiment, you + +can explore a linear dependence. + +So you have more +sensitivity here. + +Finally-- well, not finally. + +There are more. + +Next is the Ramsey spectroscopy. + +It's done in a +field-free region, + +so you're not +driving the system. + +You observe the free evolution. + +Therefore you have no AC Stark +effects due to the drive field. + +Of course, you drive the +system in the two Ramsey zones. + +And some form of AC Stark +effect may come in in the way + +that you may not +have exactly a pi + +pulse due to AC Stark effects. + +But this is sort of a +higher order effect. + +The basic spectroscopy +is done by comparing + +the atomic oscillator with +the frequency synthesizer. + +Since it's a field-free +region, this region can now + +be used for-- well, +let me say generally + +for experimental additions. + +And of course, what should +immediately come to your mind + +is the Nobel-Prize-winning +experiments + +of Serge Haroche where +he had two Ramsey + +regions with microwaves. + +And in between in the +field-free region, + +the atom passed +through another cavity. + +And in between the +Ramsey zones, the atom + +experienced a phase +shift due to the presence + +of a single photon. + +So the field-free +region could now + +be used to put in a cavity +which was filled with one or two + +photons. + +And the atom was in a +non-destructive way reading out + +how many photons were there. + +So this is another advantage +of the Ramsey spectroscopy, + +that you can now use +the field-free region + +to measure something. + +You can introduce a phase +shift, which can then + +be read out through the +Ramsey interference. + +Similarly, if you just think of +how the resonance comes along, + +if you had a slightly +fluctuating magnetic field + +between the two +Ramsey regions, this + +would not necessarily +broaden your signal. + +Because what you measure is +the integrated phase evolution + +of the atomic oscillator. + +So in other words, what you +get is shift of the resonance, + +which is the average over the +inhomogeneous magnetic field. + +Whereas when you do +a Rabi resonance, + +whenever you have a +field inhomogeneity, + +you broaden and shift the +resonance to this field value. + +So in other words, +the Ramsey resonance + +depends only on the average +along the mean energy + +separation between +the two levels. + +And therefore +inhomogeneous fluctuations, + +spatial fluctuations, can +completely average out. + +Whereas in the Rabi method, +any kind of fluctuations + +leads to line broadening. + +And finally, I will explain +that in more detail later on. + +But what happens in +the Ramsey method + +if the separation +between the two regions + +is much longer than the +spontaneous lifetime of one + +of the levels? + +Do you now get a +resolution which + +is 1/T, the temporal separation +between the two interrogations? + +Or do you get a +resolution which is 1/tau, + +the lifetime of +the excited level? + +What do you think? + +AUDIENCE: 1/tau. + +PROFESSOR: It would be +a good clicker question. + +So who thinks it's 1/tau? + +Who thinks it's 1/T? + +So who thinks it's +limited by lifetime? + +Who thinks it's limited +by the interrogation time? + +OK. + +So that's a minority +for the Ramsey method. + +The minority is correct. + +And the picture +you should have is + +that you remember the sort of +picture of those oscillators. + +But if some atoms decay away, +it diminishes your signal. + +But the interference comes +only from the survivors. + +And the survivors have survived +in the exponential tail + +of the natural decay, but +they are longer lived. + +And therefore, you can +actually do spectroscopy + +which is narrower than +the natural line width, + +using Ramsey spectroscopy. + +But if you do Rabi +spectroscopy, you're + +limited by the +spontaneous lifetime. + +And this is probably what was +in mind of the other people who + +raised their hand +for option A. But why + +there is a difference +between the Rabi + +and the Ramsey method, +that's something + +I want to discuss later. + +OK, so Ramsey has +the possibility, + +sub-natural line +width is possible + +when the interaction +time is larger + +than the inverse +natural line width. + +OK. + +Questions about Ramsey method? + +Good. + +Physics Today has a wonderful +article written by Ramsey + +which was reprinted +recently, I think + +on the occasion of his death. + +I will post this +article to our website. + +Then you can really +read about it + +in the language +of Norman Ramsey. + +OK, let's move on. + +I said we are discussing +simple examples. + +So we have discussed the example +of Rabi resonance and Ramsey + +resonance. + +Now I want to talk about line +shape with exponential decay. + +One reason why I +wanted to give you + +a simple model for +exponential decay + +because in the end, +everything is exponentially + +decaying because of the +finite lifetime of levels. + +And with this very, +very simple model, + +I want to convey to you that +not all exponential decays are + +equal. + +You have to be a +little bit careful. + +And this is just sort +of the simplest example. + +And you learn something +by figuring out + +what is different from +spontaneous decay here + +and what are the +consequences of that. + +So remember where we are. + +We have the Rabi resonance. + +I gave you the simple example +that the Rabi resonance + +is applied for fixed time tau. + +And then we did one extension +we averaged over the velocity + +distribution. + +But now we can just say, OK, we +have our Rabi resonance here. + +But we assume that +while we drive the atom, + +they decay away. + +If you want, you can think +these are radioactive atoms + +and they decay +[? radioactively. ?] + +For that situation, +this model is exact. + +So therefore, instead of having +a fixed interaction time tau, + +you have a distribution, which +is an exponential distribution. + +So all we have to do is we +have to take our result, which + +I discussed 10 or 20 minutes +ago, with the fixed interaction + +time and convolute it with +the distribution of times + +the atom experiences +the drive field. + +And what I've introduced here +is the exponential is gamma. + +And the mean interaction time +over which an atom interacts + +with the drive field +is just 1 over gamma, + +and I called that tau. + +So now we had the +Rabi probability here, + +but now we convolute it +with the distribution + +of interaction times. + +And this is now the probability +that after the Rabi pulse + +the spin was moved from +spin down to spin up. + +Or if you have an +electronic transition, + +from ground to excited state. + +So this integral can +be analytically solved. + +That's why it's +worth presenting. + +And what you get is a +Lorentzian line shape. + +And this Lorentzian +line shape shows + +power broadening, which +actually you should find nice, + +because we will +sometimes [INAUDIBLE] + +in power broadening you can't +get out of perturbation theory. + +And a lot what we have +done and what I actually + +want to do for the remainder of +this chapter on line broadening + +is a perturbative approach. + +So that's another reason I +want to present it to you here. + +These are some +non-perturbative results, + +and they show the physics of +power broadening, saturation + +broadening. + +But there are two things +which are noteworthy. + +One is the full +width at half maximum + +is not gamma but 2 gamma. + +So if we had natural +decay at a rate gamma, + +the Lorentzian which we +get is only half as wide. + +But you can +immediately say, well, + +that can be understood because +here I assumed the atoms just + +decay away no matter whether +they are in the ground + +or in the excited state. + +And I gave you a model that +you assume there is maybe + +radioactive decay independent +of the internal state. + +And now you can wave +your hands and say, OK, + +if you have only decay +in the excited state + +and not in the +ground state, this + +should give you a factor +of 2 in the width. + +And this may explain why we have +a full width of half maximum + +here of 2 gamma and in +spontaneous decay it is gamma. + +But there's another thing +which is interesting, maybe + +more interesting. + +And this is the +power broadening. + +If you take the power-broadened +Lorentzian line width + +and we look at it in +the limit of high power, + +it is 2 times the +Rabi frequency. + +Well, if we have a system +which has spontaneous decay + +and we would go to +the high power limit-- + +we've discussed it before. + +What you get is square root +2 of the Rabi frequency. + +So the message I +can give you here + +is that saturation +broadening, power broadening + +depends sensitively on the +exact nature of the decay + +and of the lifetime +broadening involved. + +And if you really +want to do it right, + +you have to use the +optical Bloch equations. + +So let me just write that down. + +So what we learned from that is, +yes, we get power broadening. + +We have a simple model +for power broadening here. + +But power broadening +depends sensitively + +on the nature of +the decay process. + +And so if you want to get this +result without any assumptions + +or approximations, you +should use the optical Bloch + +equations. + +And yes, your +homework assignment + +looked at the optical +Bloch equations. + +And I think you also found +out that some results + +for the optical Bloch +equations really + +depend on the ratio of gamma +1 gamma 2 or T1 and T2. + +So that is with a more +mathematical formalism + +shows you that the way +how you introduce decay + +into the atomic system, it's not +just there is one time constant + +and the result just depends +on the time constant. + +There are some subtleties. + +Questions about that? + +OK. + +Now-- and many people +have asked me about it-- + +I think for the first +time in this course + +we bring in motion of the atoms. + +So the atoms are now not +pinned down at the origin. + +Maybe you can imagine +you have an atom which + +is held in a solid state +lattice with a nanometer, + +and we just look at +the internal structure. + +We have maybe some ions +implanted into a material. + +And these ions are fluorescent, +and we are probing them. + +Or we're doing spin +flip on nuclei, + +which are nuclei of atoms which +are part of a condensed metal + +lattice. + +Or if you want to think +more [? with ?] the methods + +of atomic physics, you have the +most tightly confining ion trap + +in the world. + +You are deeply in +the Lamb-Dicke limit, + +and your ion just cannot move. + +It's always in the ground +state of the ion trap, + +and all you are dealing with is +the internal degree of freedom. + +Actually, let me make a comment. + +I often see when people +approach me and ask + +me question that they +are not necessarily + +making the separation. + +When they think +about what happens + +to the internal +structure of atoms, what + +is in their head is, but there +is motion, there is recoil. + +You can, in my experience, +always separate the two. + +You can create a +situation where you only + +probe the internal +degree of freedom + +by tightly confining +the atom, and then you + +can relax the condition that +the atoms is tightly confined. + +Now the atoms can +move, and then all + +of the things we want to +discuss now come into play. + +Sometimes people assume, yes, +but if you confine an atom, + +doesn't the atom always have +a de Broglie wavelengths? + +And isn't that +another length scale? + +The answer is no, +because you need + +a coupling between the internal +degree and the external degree, + +or you need some way of exciting +the external degree of motion. + +And if you have a tightly +confining ion trap, + +h bar omega, the next vibration +or level in the ion trap + +is so high, you may not excite +it with the recoil of a photon. + +But there is another limit +which I often find very useful, + +and this is the following. + +When we talk about +spectroscopy, spin flips, + +electronic transitions, +we have not really + +talked about the +mass of the atom. + +The mass of the nucleus only +appeared in the reduced mass. + +Remember when we did last +class the hydrogen atom? + +We had the reduced mass, +which was slightly different + +from the electron mass. + +So if you want to completely +exclude the motion of the atom, + +just work in the limit that +the nucleus has infinite mass. + +If the nucleus +has infinite mass, + +its de Broglie wavelength is 0. + +It's confined in a +harmonic oscillator + +to sort of a delta function. + +So by just assuming that +you deal with infinite mass, + +you automatically neglect +all possible motions. + +And as you will actually +see from the next formula, + +working in the infinite mass +limit means that your Doppler + +shift is 0, your recoil +shift is 0, everything is 0. + +So either way, +I've given you now + +two ways how I recommend +that you think about all + +the physics we have +discussed which + +deals with the internal +degree of freedom + +by either saying the atom +is tightly organized. + +But then some people +say, ah, but then + +it has Heisenberg Uncertainty. + +There's a lot of momentum. + +It doesn't matter. + +If it's localized, +it's localized. + +But you can also assume just +the infinite mass limit. + +And in both cases, the +result is you can completely + +talk about so many aspects +of internal excitations + +without even considering +what happens externally. + +Any questions about that? + +So now we take the mass from +infinity to finite value, + +and now we want +to allow the atom + +to move and have kinetic energy. + +So let's start out very simple. + +We have an atom which is +addressed in the excited state, + +and it emits a photon. + +Before the emission +of the photon, + +the total energy is +the excitation energy. + +But after the emission +of the photon, + +the atom is in the ground state. + +The photon has been emitted. + +But now the atom, due to +the photon recoil h bar k, + +has kinetic energy. + +So therefore the frequency +of emission of the photon + +does not happen at the +resonance frequency of the atom + +because some part of +the electronic energy + +goes into the kinetic energy +of the recoiling atom. + +And this is called +the recoil shift. + +We start at 0 velocity. + +At 0 velocity, you don't +have any Doppler shift. + +But you do have recoil shift. + +Well, we can play the same game. + +We have an atom addressed. + +It absorbs the photon. + +And after the atom has +absorbed the photon, + +it's in the excited state. + +But now you have +to excite the atom + +if you want to transfer +the atom to the excited + +state with a frequency +which is slightly + +higher than the +resonance frequency. + +Because the laser has +to provide not only + +the energy for the +electronic excitation + +but also the energy for +the kinetic energy at which + +the atom recoils. + +So therefore we find that, due +to the recoil of the photon, + +the absorption line +and the emission + +line for an atom +addressed are shifted. + +The shift is the +recoil energy, h bar-- + +the momentum of the photon +squared, divided by 2 times + +the mass of the atom. + +And the shifts are opposite +for absorption and emission. + +So therefore, if you look at +the two processes for absorption + +and emission, there is a recoil +splitting between the two. + +This recoil splitting between +emission and absorption + +is just a few kilohertz. + +And it was really one of the +wonderful accomplishments + +when high resolution +spectroscopy came along + +and John Hall at +Boulder managed to have + +lasers stabilized +to sub kilohertz. + +For the first time, this recoil +splitting could be resolved. + +So he had set up some +intracavity absorption, + +and he saw sort of two peaks +in some kind of spectrum. + +I don't remember the +details, but two peaks + +split by a few +kilohertz were really + +the hallmark of the photon +recoil shifting the lines away + +from resonance. + +OK, so now we know what the +kinetic energy of the atom + +does. + +If it emits a photon, +there is recoil. + +But now, in addition, we +can drop the assumption + +that the atom is initially at +rest when it absorbs or emits. + +Now the atom is moving. + +But for that, we don't +need any new concept. + +Because the moving atom-- we +can just do a transformation + +into the frame of the atom +where the atom is at rest. + +And then just using the +relativistic transformation, + +we are now transferring +the laser frequency + +from the atomic frame +into the lab frame. + +So what I've +written down here is + +the general special +relativity formula + +for the frequency shift. + +And I've assumed that +the photon is emitted + +at an angle phi with respect +to the motion of the atom. + +So now we obtain-- OK, let me +do a second-order expansion. + +Usually, our atoms +are non-relativistic, + +so it's the first- and +second-order term which + +are most important. + +And if we are now +looking in the lab frame, + +what is the frequency where +we emit and absorb photons. + +It's a resonance frequency +minus/plus the recoil shift, + +which we have already +discussed in isolation + +by assuming we have +atoms at 0 velocity. + +But now the velocity +of the atom leads + +to a first-order and +second-order Doppler shift. + +If v/c is small, what +is most important + +is the first-order +Doppler shift. + +And in almost all cases +[? where we ?] do spectroscopy, + +dominant line +broadening effect comes + +from the first-order shift. + +However, let me point out +that the first-order shift can + +be suppressed. + +One simple way to suppress +it-- interrogate the atoms + +at an angle of 90 degrees. + +Have an atomic beam. + +And if you interrogate them +with a laser beam at 90 degrees, + +the cosine phi is 0. + +k dot v is 0. + +And this is the oldest method +to do Doppler-free spectroscopy. + +In your new homework +assignment, you + +will discuss saturation +spectroscopy. + +If you have a broad +velocity distribution, + +but you find a way of labeling +atoms with a certain velocity + +class, then you have created +your own narrow velocity class + +where the Doppler +broadening is absent + +because you've only +one velocity class. + +And these methods of nonlinear +spectroscopy, the concept + +will be developed in +the homework assignment. + +Finally-- and this will +be the next chapter + +which we talk in class here +in about two weeks-- this + +is by having two-photon +spectroscopy. + +To give you the +appetizer, if you + +have two photons from opposite +direction, the Doppler shifts. + +One has a positive, one has +a negative Doppler shift. + +And if you stack +up the two photons, + +the sum of the two +Doppler shifts is 0. + +So two-photon spectroscopy +provides you an opportunity + +to completely eliminate +the Doppler shift. + +However, no matter what you +pick here for the angle, + +there is a part of the +second-order Doppler + +shift you can never get rid of. + +And this is something +important to keep in mind. + +The second-order Doppler +shift, at least one part of it, + +comes from the relativistic +transformation of time. + +So if you have atoms moving +at different velocities, + +time in the frame of the atom +ticks slightly differently + +depending what the velocity is. + +And therefore, if +you do spectroscopy, + +you measure time +in the lab frame, + +but the atoms measure time +in the resonance frequency + +in their own frame. + +Then there is +inevitably broadening. + +So for instance, when people +did Ted Hansch's experiment, + +the famous two-photon +spectroscopy + +on hydrogen, high resolution, +determination of the Lamb + +shift, the Rydberg constant-- +one of the flagship experiments + +of high resolution +laser spectroscopy. + +A limit is the +second-order Doppler effect + +because of its +relativistic nature. + +And the only way to suppress +the relativistic Doppler effect + +is by cooling the atoms, +reducing their velocity. + +So let me just write that down. + +So when we suppress +the first-order effect, + +then the limit is given +by the second-order term. + +And just repeat, the +second-order term cannot be + +eliminated by playing +geometric tricks, + +90-degree angles and such, +because it's fundamentally + +rooted in the relativistic +definition of time. + +OK. + +Any questions about recoil +shifts, Doppler shifts? + +Yes. + +AUDIENCE: What are +the correct way + +to determine whether +we're in tightly confined + +[? regime ?] or not? + +PROFESSOR: OK, the +question is what + +is the criteria on whether we +are tightly confined or not. + +I will give a full answer +to that in about a week when + +I discuss with you +in great detail + +the spectrum of a +confined particle. + +And what we will +introduce is it's + +the frequency of +harmonic confinement. + +And we have to +compare the frequency + +of harmonic confinement +to two other relative, + +to two other +important frequencies. + +One frequency is the +recoil frequency. + +And another one may be +the natural line width. + +So in other words, when +we discuss the spectrum + +of confined particles, +we can discuss it + +as a function of three +parameters-- confinement + +frequency, recoil frequency, +and natural line widths. + +And based on the hierarchy +of those three frequencies, + +we find limiting cases. + +And we will find, then-- +and this is probably + +what you are aiming for-- at +some limit when you reduce + +the confinement in your +harmonic oscillator, + +you will actually retrieve +the free gas limit. + +Or to be very brief, +confinement, you + +have the benefit of confinement. + +Confinement means the +motion of the atom + +is quantized in +units of h bar omega. + +So you shouldn't +think about velocity. + +You should think +about discrete levels. + +And I will show you that the +spectrum which is broadened + +becomes a spectrum with +discrete levels and side bands. + +As long as you can resolve the +side bands, you can see them, + +you can actually +address the line + +in the middle which has +no motion blurring at all. + +But you have to resolve it. + +So one condition here now is +that the harmonic oscillator + +frequency is larger than +the natural broadening + +of each line. + +If the lines blur, you're +pretty much back to free space + +and you've lost the +advantage of confinement. + +But maybe we can discuss +some of those aspects + +after I've introduced the line +shape of confined particles. + +OK. + +OK. + +Let me now discuss +briefly, or use + +what we have just discussed +about Doppler shift + +to discuss the line +shape in a gas. + +Well, of course, line +shapes in a gas-- + +that's what all people observed +when they did spectroscopy + +before the advent of +trapping and cooling. + +But even now, we +often have a situation + +that we have a thermal clouded +microkelvin temperature. + +And what we see is +still broadening + +due to the thermal motion. + +So therefore, let +me just tell you + +a few aspects of that which +you might find interesting. + +So one is when we have +an non-degenerate gas, + +this is described by a +Boltzmann distribution, sort + +of a Gaussian +distribution of velocity. + +And therefore, if the +first-order Doppler shift + +is relevant, the +first-order Doppler shift + +is proportionate to v, +so therefore the spectrum + +we observe is nothing else +than the spectrum in velocity + +multiplied with a k vector. + +The Doppler shift is k dot +v, and therefore the velocity + +distribution by +multiplying it with k + +is turned into a +frequency distribution. + +And so the classic +frequency distribution + +you would expect +in a gas is simply + +the Gaussian distribution. + +And the Doppler width, +the spectroscopic width, + +is nothing else than whatever +the characteristic speed + +in your Boltzmann +distribution is, typically + +the most probable speed, 2 times +the temperature over the mass + +multiplied with the k vector. + +And in many cases, it is this +Doppler width which dominates. + +I've just given you +typical examples here. + +If you've stabilized your laser +to a room temperature vapor + +cell, you will encounter +typical Doppler widths + +on the order of 1 gigahertz. + +This is 100 times larger than +the natural line width, which + +is 100 times larger +than the recoil shift. + +So that is the usual +hierarchy of shifts + +and broadening mechanisms. + +So therefore, you would +think that if the Gaussian + +line widths due to the +velocity distribution is + +100 times larger than the +natural line widths which + +is described by Lorentzian, +you can completely + +neglect the Lorentzian. + +But that's not the +case, and that's + +what I want to discuss now. + +What happens is you +have a Gaussian which + +is much, much broader. + +But the Gaussian +decays exponentially, + +whereas your narrow Lorentzian +decays with a power law. + +So just to give you +the example, if you + +go two full +half-line widths away + +from the center of a +Gaussian, the Gaussian + +has dropped to 0.2%. + +The Lorentzian has still 6%. + +So therefore, what +happens is if you + +have your gigahertz +broadened line in a gas, + +but you go further +and further away, + +at some point what +you encounter are not + +the Gaussian wings but +the Lorentzian wings. + +And that's maybe also sort of +intellectually interesting. + +I've talked to you about +homogeneous, inhomogeneous line + +widths. + +The bulk part of the +Gaussian is inhomogeneous + +because you can talk +to different atoms + +at different velocities. + +Each atom resonates +with its own Lorentzian, + +and it is inhomogeneously +broadened. + +But in the line widths which +is due to the Lorentzian, + +the homogeneous +broadening dominates. + +And since the Lorentzian +has information + +about either the +natural line widths + +or in a gas about +collisional broadening, + +you can actually, far away in +the wings of your line shape, + +retrieve information about +collisional physics, which, + +in the center of the +line, is completely + +masked by the first-order +Doppler shift. + +OK. + +So I've already written it down. + +So far wing spectroscopy +in the gas phase + +can give you +interesting information + +about atomic collisions +and atomic interactions. + +So having started +out by telling you + +that it's a first-order Doppler +shift which usually dominates, + +but then telling you that if +you go far away from the line + +center, the Lorentzian actually +dominates, that means now there + +are situations where +we want actually both. + +And the general +solution, of course, + +is you do a convolution. + +Each atom with a given +velocity has a Lorentzian. + +And then you have to do the +convolution with the velocity + +distribution. + +So therefore, the general +situation for gas phase + +spectroscopy is the +convolution of the Lorentzian + +for each atom and the Gaussian +velocity distribution. + +And since this was the standard +case which people encountered + +when they did spectroscopy +in the gas phase, + +this convoluted line +shape has its own name. + +It's called the Voigt profile. + +Colin. + +AUDIENCE: It's not +obvious to me what exactly + +about the atomic +collisions and interaction, + +the wings of the +Lorentzian [INAUDIBLE]. + +Don't you just learn +about the bare line? + +Like the un-Doppler +shifted line itself? + +PROFESSOR: OK, that's a good +question, as it is not obvious. + +And yes, the literature +is full of it. + +Because if you don't have +Doppler-free spectroscopy, + +if you are always limited +by the Doppler broadening, + +put yourself back +into the last century. + +But you really want +to learn something + +about how atoms +interact and collide, + +this was the way to do it. + +I don't want to go +into many details + +because it's a little +bit old fashioned. + +We have other ways to do it now. + +But I find it +intellectually interesting + +when we talk about line shapes +to realize there are maybe + +some subtleties we wouldn't have +thought about it by ourselves. + +But just to give you one +example, for whatever reason, + +you're very, very interested. + +What is the rate of +collision of atoms? + +Let's just assume the +simplest model for collisions + +that when two atoms collide, +the excited state is de-excited. + +Then the lifetime +of the excited state + +is no longer 1 over +gamma, the lifetime + +is the collision time defined +as a de-excitation time. + +And you're really interested +for whatever reason, + +because you have the world's +best theory on this object, + +that you have a theory what is +the collision time for excited + +sodium with argon, +with helium, kind + +of with all different elements. + +And you have an +interesting theory + +which actually reflects how +sodium in the excited state + +would interact with noble gases. + +And you really want +to test your theory. + +Well, now what happens is +the situation is simple. + +You have a Lorentzian, +but the Lorentzian + +has a broadening which +is the collision rate. + +And by carefully analyzing the +wings of your Doppler profile, + +you find the collision rate-- +as a functional of buffer + +gas density, as a function of +noble gas, whatever you pick. + +That's one example. + +Another example would +be, there may be also + +somewhere nontrivial shifts +when the atoms collide. + +We'll talk about it +also a little bit later. + +The experience-- de-excitation +is one possibility. + +But more subtle +things can happen. + +For instance, just a +phase perturbation, + +or when atoms come +close to each other, + +they feel the electric field. + +And the electric field +causes an AC Stark shift. + +But by understanding the +AC Stark shift or AC Stark + +broadening which +comes along with that, + +you can maybe map out +the interaction potential + +between two atoms. + +So people were really +ingenious in trying + +to learn something about +atomic interactions + +from spectroscopic +information, and that + +was one of the few +tools they had. + +Other questions? + +OK. + +We have covered the +simple examples. + +And now I want to give you a +more comprehensive framework + +called perturbation theory +of spectral broadening. + +And in the last class, I +mentioned to you already + +that, by using +this framework, we + +can more deeply understand +line broadening mechanisms. + +And one highlight actually +will be that next week, + +using these concepts, we +will actually understand that + +collisions cannot only cause +collisional broadening, + +they can also cause +collisional narrowing. + +So some things which +are counterintuitive + +have a very clear description +using this method. + +So I think what I'm able to do +in the remaining 20 minutes is + +to step you through +the derivation. + +And then we apply it to a +number of interesting physical + +situations next week. + +Now, in a way, I +have to apologize + +that what I present to you is +time dependent perturbation + +theory again. + +And again with a slightly +different notation, so + +I think I go rather quickly for +the part which is just review. + +But repeating something +is also a good thing. + +But then I will +tell you when we go + +beyond what we have +discussed and beyond what you + +may have seen in textbooks. + +So in other words, we do time +dependent perturbation theory. + +We have a wave function which +is in two states, A and B. + +And there's a time dependent +perturbation v. Schrodinger's + +equation tells us that it's +probably the interaction + +picture, that the rate of +change of the amplitude B + +comes because we +start in the state A + +and the perturbation +couples from state A to B. + +And so we can solve it. + +At this point, it's not even +perturbative, it's general. + +And we are interested +in spectroscopy + +in the rate of a transition, +because we do spectroscopy + +and we measure what is the +population in the excited + +state. + +Because there was +a rate at which + +atoms were transferred from +the calm to the excited state. + +So the rate is the +probability to be + +in the excited +state per unit time. + +So what we are interested now +is, what is the amplitude B? + +And what is the +probability B squared + +to be in the excited state? + +And now comes +perturbation theory. + +If we take +Schrodinger's equation + +and we integrate it with respect +to time-- so we go from B dot + +to B-- we are integrating +here with respect to time. + +And in first-order +perturbation theory, + +we assume the initial +state is undepleted. + +And we replace the amplitude +A of t by its value at time t + +equals 0, which is +assumed to be unity. + +OK. + +So with that-- oh yeah, +and this may be something. + +I'm not doing anything which +goes beyond perturbation + +theory, but I'm using a +slightly different formulation. + +Because you will see that +I need it in a moment. + +The rate is dB squared dt. + +And if I take the +derivative of B squared, + +I get B or B star times B dot. + +So now I'm using +the perturbative-- + +I'm inserting this function +B into this expression + +for the rate. + +And this is what I obtain. + +So I can take the +time derivative of it, + +but the time derivative is only +affecting the upper integral. + +So therefore what I get +is B is the integral. + +B dot is the integrand. + +And now I get this +expression, which + +has the product of the +two matrix elements. + +Simple mathematics, +plug and play. + +No new concept. + +But what it leads us now is, +and this is what is usually + +not so much emphasized +in perturbation + +theory, that everything +which happens to the atom, + +and this is the rate at +which we excite the atom, + +is now involving a +correlation function. + +It involves sort of an +integral over the drive field v + +at time t and time t prime. + +And this is the +important concept + +when you want to +explain and understand + +line broadening and such. + +You are driving the system +with an external field. + +And often in +perturbation theory, + +you assume the external field +is just e to the i omega t, + +and this correlation function +is just e to the i omega t. + +And it's so trivial that you +don't even recognize that e + +to the i omega t is not the +time dependence of your field. + +e to the i omega t is sort of +the product of the field at t + +equals 0 and the field at time +t and the field at time t prime. + +But if you have a more +general field with lots + +of Fourier components, the +difference between whether it's + +a correlation function or the +field itself becomes important. + +In other words, +I'm now telling you + +whenever you did perturbation +theory, this is what you did. + +Maybe you didn't notice it, +but what you had was actually + +the correlation function +between the drive field + +at two different +times, t and t prime. + +OK, so our rate is now given +by the correlation function + +of the field. + +And then we so-to-speak +Fourier transform it + +with e to the i omega 0. + +OK. + +Let's just streamline +the expressions, + +make them look nicer. + +We integrate between +time 0 and t. + +But let's now assume-- +which is actually + +the situation for many +fields of interest-- + +that the field is invariant +against translation in time t. + +So therefore this +correlation function + +does not depend on two times. + +It only depends on the +time difference tau. + +Finally, because of the complex +character of the Schrodinger + +equation, I had an +expression but I + +had to add the +complex conjugate. + +Remember, the rate was the +derivative of B square. + +And the derivative of B +square is B star B dot + +times B star dot times B. + +You get two terms. + +And this is carried forward +with the complex conjugate. + +But if the correlation +function has the proper t, + +that complex conjugation means +you can go to negative time. + +e to the i omega t +complex conjugate + +is e to the minus i omega t. + +That means now that we can +absorb the complex conjugate + +by integrating not +from 0 to t, but having + +the integral from +minus t to plus t. + +And this will be the next +step for most situations + +of interest. + +This correlation, if you +drive it with the field, + +the field has a +finite coherence time. + +So therefore this +integral will not + +have any contribution +when the times are + +longer than the coherence time. + +And then we can set minus +t and plus t to infinity. + +So that will be our +final expression + +which we will use to discuss +line broadening and line + +shifts. + +But we are not yet there. + +We need-- so far, I've just done +ordinary perturbation theory. + +The one extra thing +is I'm stressing + +that when we have +a product of-- when + +we had a matrix element +squared in perturbation theory, + +this is really a correlation +function between the + +[? external, ?] the drive +field at two different times. + +We come back to that when +I discuss the result. + +But the second thing I +want to introduce now + +is that this framework, +which I have formulated, + +allows me now to +include the fact + +that different +atoms in my ensemble + +may experience a +different drive field. + +For instance, I gave you +the example in last class, + +if you have Doppler +broadening, you + +have atoms which start +out at the same point. + +But the faster ones move faster +and experience the laser field + +now with a different phase. + +So different atoms +now experience + +the perturbation v +in a different way. + +So what I've done here so far +is I've pretty much written down + +Schrodinger's equation +for a single particle. + +But now we have to do +an ensemble average. + +So therefore I introduce +now an ensemble average + +by just taking that +expression and averaging + +over all atoms in the ensemble. + +So then I get the +ensemble averaged rate. + +All the correlation +functions we discussed, + +our ensemble averaged +correlation functions + +and our final result will +also have an ensemble average. + +OK. + +So this correlation function +between v of 0 and v of t + +will go to 0 for +very long times. + +Even the most expensive laser +in the world, the electric field + +which is emitted +now is not related + +to the electric field which +is emitted in an hour. + +Because the phase +relationship has been lost, + +and therefore the correlation +function has decayed to 0. + +OK. + +So this is the ensemble average. + +So therefore, what I'm +naturally drawn to now + +is that if I take this +correlation function, + +and I know any +correlation function has + +a characteristic time called the +coherence time where it decays. + +And therefore I can now +discuss two limiting cases. + +One is where the time +evolution of the system + +is started for times much +shorter than the coherence time + +or much longer than +the coherence time. + +And if what I'm +telling you right now + +reminds you of my discussion of +Rabi oscillation versus Fermi's + +golden rule-- yes, +this is actually + +a very analogous discussion. + +OK, so there are the +two limiting cases. + +If the time is much shorter +than the coherence time-- let + +me give you the example of an +oscillating single mode field. + +The perturbation v of +t is just oscillating + +with one frequency, omega. + +And that means if I look +at the correlation function + +at time t and time +t plus tau, it + +is simply the +amplitude of the field + +squared times e +to the i omega t. + +And now I can take this +correlation function; + +put it into my +integral, which has just + +disappeared from the screen; +do the integration with e + +to the i omega 0 t. + +And this is the result I obtain. + +And of course, this +is nothing else + +than what you have +always obtained + +in time dependent perturbation +theory with a sinusoidal field. + +It is this characteristic +sine detuning + +t over detuning, +which in the limit + +and in the limit of when +you square it and go + +to the limit of long times, it +turns into a delta function. + +This gives us +Fermi's golden rule. + +And of course, it has the +same behavior at short times. + +At short times, the +probability for the atom + +to be in the excited +state is quadratic. + +Quadratic is like an +incipient Rabi oscillation. + +And in perturbation theory, +we never get higher up. + +We just look at the +beginning Rabi oscillation. + +So therefore, the +probability is quadratic. + +But I'm talking about +the rate, and the rate + +is probability divided by time. + +So that means the rate is +linearly increasing in time. + +So I'm just saying this is +nothing else than rewriting + +the physics of +Rabi oscillations. + +OK. + +If the time is longer +than the coherence time, + +then we integrate the integral, +not from minus t to plus t. + +We can take the +limits to infinity. + +And that means we +obtain a result + +which is now +independent of time. + +And that means since +Wba is the rate, + +we retrieve a constant +rate, and this + +is what we have done +in Fermi's golden rule. + +So therefore, when we +look at the time evolution + +of a system driven by an +external field, the moment + +we look for the time evolution +longer than the coherence + +time-- and this is +where the main interest + +is in spectroscopy-- we +have a Fermi's golden rule + +result that the system is +excited at a constant rate. + +And I want to now +reinterpret this rate. + +This rate is nothing else +than the Fourier transform + +of a correlation function. + +It makes a lot of sense. + +You apply time-dependent +magnetic fields, perturbations, + +fluctuating magnetic fields, +whatever, vibration and noise + +in your lab. + +You just apply that to +the atom, and the atom + +is nothing else than a +little Fourier analyzer. + +It says, my resonance +frequency is omega 0. + +And all of what matters for +me to make a real transition + +is what you offer me at omega 0. + +And I now Fourier +analyze whatever + +acts on me, the correlation +function of the perturbation + +which acts on me, and +I fully analyze it. + +And what matters for my rate +to go to the excited state + +is the Fourier component +at the resonance frequency. + +It's just a +generalization of what + +we have done in +perturbation theory + +when we assumed that we +have a drive field only + +at one frequency. + +So I've written it +down here for you. + +The rate of excitation +is nothing else + +than the Fourier transform +of this correlation function. + +But let me now take +it one step further, + +which also makes a lot of sense. + +The Fourier transform +of the correlation + +function-- the +correlation function + +is the convolution of +the time-dependent fields + +with themselves, v of +t with v of t plus tau. + +The Fourier transform +of the convolution + +is the product of the Fourier +transform of the field itself. + +So therefore, I +can take whatever + +perturbation the atom +experiences in its own frame-- + +external fields, moving around. + +Whatever the atom +is exposed to, I + +have to calculate +the power spectrum + +of what the atom feels. + +And this power spectrum +provides me the excitation rate. + +It's nothing else than +Fermi's golden rule + +but generalized to the +concept of an arbitrary + +spectrum of the driving field. + +Questions so far? + +You can also say +that's a wonderful way + +to look at energy conservation. + +If an atom is exposed to +any kind of environment, + +it goes from the ground +to the excited state only + +to the extent that whatever +acts on the atom has a Fourier + +component at the +resonance frequency. + +And it is only the power +of the fluctuating drive + +field at the resonance +frequency which + +is responsible for +driving the atom. + +And this is energy conservation. + +The frequency component +has to be omega 0 + +to take the atom from the +calm to the excited state. + +All the other +frequency components + +take the atom to the virtual +state and take it down again. + +They create maybe line shifts +or something like this. + +But a real transition, +a transition + +where the atom stays +in the excited state, + +requires photons at the +resonance frequency. + +And so to speak, this +measures how many + +photons are acting on the atoms. + +Let me now give you one +or two general features + +of such correlation +functions which I just + +find very, very useful. + +And then I think +your time is over. + +If we have G of w +is now the spectrum + +of the fluctuating fields. + +And let's assume, +yes, eventually we + +have a fluctuating +field which is somewhere + +centered at the +resonance frequency. + +After all, we use a +laser, but the atom + +may now move around +in the laser beam. + +The mirrors may be vibrating. + +So the spectrum seen +by the atom is sort of + +broadened around the +resonance frequency. + +And the broadening is +nothing else than 1 + +over the coherence time +of the environment. + +So let me just normalize +the correlation function + +that the integral is unity. + +And then this is +trivial but important. + +The value at the +resonance frequency + +is 1 over the broadening and is +therefore the coherence time. + +It's sort of subtle +but important. + +If you have a +normalized spectrum, + +the more coherent +your source is, + +the larger is the value +of the correlation + +function in the center. + +Let me do the Fourier transform. + +If you Fourier transform +something like this, + +it gives an oscillating function +at the resonance frequency. + +But let me just multiply by +e to the i omega t and sort + +of shift everything +to 0 frequency, + +then we would find that +the temporal correlation + +function decays. + +And it decays over +characteristic time tau + +coherence, which is nothing +else than the inverse line + +bits of the Fourier transform. + +This has nothing to do +with atomic physics. + +It's just properties of the +function is Fourier transform. + +But now we have the situation. + +Our rate was the temporal +correlation function times e + +to the i omega 0 t. + +The integrand here is exactly +what I'm plotting here. + +And so if I perform +the integration, + +at least without getting +the last numerical factor, + +I can approach the result by the +correlation function at time t + +equals 0 times-- if I +do the integration-- + +times the temporal +rates of this curve, + +so this is the +correlation time tau c. + +So therefore, if I have, +for instance, my operator + +is the electric +field and I drive + +the atom with a +dipole operator, what + +I find is the +correlation function at t + +equals 0 is nothing else than +the electric field squared, + +which is what we have called the +Rabi frequency squared so far. + +But now I multiply it +with a coherence time. + +So this result should +come very naturally to you + +because when we have +Fermi's golden rule, + +we have a matrix element squared +times the delta function. + +But I've emphasized it again +and again-- the delta function + +is representative for spectral +widths for density of states. + +And if we have an +environment which + +causes spectral broadening, +1 over the coherence time + +is nothing else than the +spectral widths here. + +And so I've done here exactly +what the delta function + +Fermi's golden rule +asked me to do. + +So if I had wanted, I +could have just said, + +look, here is +Fermi's golden rule. + +And by interpreting Fermi's +golden rule the way I just did, + +I could have written down this +result for you right away. + +OK, I think time is over. + +And maybe the +summary which I could + +give you now is a +good starting point + +for our lecture on Monday. + +Reminder, Friday we have the +midterm in this other lecture + +hall in the other building. + +We start at the +normal class time. + +Please be there on time. \ No newline at end of file diff --git a/OlKmZj2TKnk.txt b/OlKmZj2TKnk.txt new file mode 100644 index 0000000000000000000000000000000000000000..958fd523441e3f33d9913fd2f1eb9d92fda38490 --- /dev/null +++ b/OlKmZj2TKnk.txt @@ -0,0 +1,811 @@ +align:start position:0% + +in the next variation that we consider + + align:start position:0% +in the next variation that we consider + + + align:start position:0% +in the next variation that we consider +the random variable theta is still + + align:start position:0% +the random variable theta is still + + + align:start position:0% +the random variable theta is still +discrete so it might for example + + align:start position:0% +discrete so it might for example + + + align:start position:0% +discrete so it might for example +represent a number of alternative + + align:start position:0% +represent a number of alternative + + + align:start position:0% +represent a number of alternative +hypotheses but now the observation is + + align:start position:0% +hypotheses but now the observation is + + + align:start position:0% +hypotheses but now the observation is +continuous of course we do have a + + align:start position:0% +continuous of course we do have a + + + align:start position:0% +continuous of course we do have a +variation of the Bayes rule that's + + align:start position:0% +variation of the Bayes rule that's + + + align:start position:0% +variation of the Bayes rule that's +applicable to this situation the only + + align:start position:0% +applicable to this situation the only + + + align:start position:0% +applicable to this situation the only +difference from the previous version of + + align:start position:0% +difference from the previous version of + + + align:start position:0% +difference from the previous version of +the Bayes rule is that now the PMF of X + + align:start position:0% +the Bayes rule is that now the PMF of X + + + align:start position:0% +the Bayes rule is that now the PMF of X +the unconditional and the conditional + + align:start position:0% +the unconditional and the conditional + + + align:start position:0% +the unconditional and the conditional +one is replaced by a PDF otherwise + + align:start position:0% +one is replaced by a PDF otherwise + + + align:start position:0% +one is replaced by a PDF otherwise +everything remains the same a standard + + align:start position:0% +everything remains the same a standard + + + align:start position:0% +everything remains the same a standard +example is the following + + align:start position:0% +example is the following + + + align:start position:0% +example is the following +here we are sending a signal that takes + + align:start position:0% +here we are sending a signal that takes + + + align:start position:0% +here we are sending a signal that takes +one of let's say three alternative + + align:start position:0% +one of let's say three alternative + + + align:start position:0% +one of let's say three alternative +values and what we observe is the signal + + align:start position:0% +values and what we observe is the signal + + + align:start position:0% +values and what we observe is the signal +that was sent plus some noise and the + + align:start position:0% +that was sent plus some noise and the + + + align:start position:0% +that was sent plus some noise and the +typical assumption here might be that + + align:start position:0% +typical assumption here might be that + + + align:start position:0% +typical assumption here might be that +the noise has zero mean and a certain + + align:start position:0% +the noise has zero mean and a certain + + + align:start position:0% +the noise has zero mean and a certain +variance and is independent from the + + align:start position:0% +variance and is independent from the + + + align:start position:0% +variance and is independent from the +signal that was sent this is an example + + align:start position:0% +signal that was sent this is an example + + + align:start position:0% +signal that was sent this is an example +that we more or less studied some time + + align:start position:0% +that we more or less studied some time + + + align:start position:0% +that we more or less studied some time +ago actually at that time we looked at + + align:start position:0% +ago actually at that time we looked at + + + align:start position:0% +ago actually at that time we looked at +an example where theta could only take + + align:start position:0% +an example where theta could only take + + + align:start position:0% +an example where theta could only take +one out of two values but the + + align:start position:0% +one out of two values but the + + + align:start position:0% +one out of two values but the +calculations and the methodology remains + + align:start position:0% +calculations and the methodology remains + + + align:start position:0% +calculations and the methodology remains +essentially the same as for the case of + + align:start position:0% +essentially the same as for the case of + + + align:start position:0% +essentially the same as for the case of +three values so in principle we do know + + align:start position:0% +three values so in principle we do know + + + align:start position:0% +three values so in principle we do know +at this point how to apply the Bayes + + align:start position:0% +at this point how to apply the Bayes + + + align:start position:0% +at this point how to apply the Bayes +rule in this situation to come up with a + + align:start position:0% +rule in this situation to come up with a + + + align:start position:0% +rule in this situation to come up with a +conditional pmf of theta and the key to + + align:start position:0% +conditional pmf of theta and the key to + + + align:start position:0% +conditional pmf of theta and the key to +that calculation was that the term that + + align:start position:0% +that calculation was that the term that + + + align:start position:0% +that calculation was that the term that +we need the conditional PDF of X can be + + align:start position:0% +we need the conditional PDF of X can be + + + align:start position:0% +we need the conditional PDF of X can be +obtained from this equation as follows + + align:start position:0% +obtained from this equation as follows + + + align:start position:0% +obtained from this equation as follows +if I tell you the value of theta then X + + align:start position:0% +if I tell you the value of theta then X + + + align:start position:0% +if I tell you the value of theta then X +is essentially the same as W plus a + + align:start position:0% +is essentially the same as W plus a + + + align:start position:0% +is essentially the same as W plus a +certain constant adding a constant just + + align:start position:0% +certain constant adding a constant just + + + align:start position:0% +certain constant adding a constant just +shifts the PDF of W by an amount equal + + align:start position:0% +shifts the PDF of W by an amount equal + + + align:start position:0% +shifts the PDF of W by an amount equal +to that constant and therefore the + + align:start position:0% +to that constant and therefore the + + + align:start position:0% +to that constant and therefore the +conditional PDF of X is the shifted PDF + + align:start position:0% +conditional PDF of X is the shifted PDF + + + align:start position:0% +conditional PDF of X is the shifted PDF +of the random variable W using this + + align:start position:0% +of the random variable W using this + + + align:start position:0% +of the random variable W using this +particular fact we can then apply the + + align:start position:0% +particular fact we can then apply the + + + align:start position:0% +particular fact we can then apply the +Bayes rule carry out the calculations + + align:start position:0% +Bayes rule carry out the calculations + + + align:start position:0% +Bayes rule carry out the calculations +and suppose that in the end we came up + + align:start position:0% +and suppose that in the end we came up + + + align:start position:0% +and suppose that in the end we came up +with these results that is we obtain the + + align:start position:0% +with these results that is we obtain the + + + align:start position:0% +with these results that is we obtain the +specific observation X and based on that + + align:start position:0% +specific observation X and based on that + + + align:start position:0% +specific observation X and based on that +observation we calculate the conditional + + align:start position:0% +observation we calculate the conditional + + + align:start position:0% +observation we calculate the conditional +probabilities of the different choices + + align:start position:0% +probabilities of the different choices + + + align:start position:0% +probabilities of the different choices +of theta + + align:start position:0% +of theta + + + align:start position:0% +of theta +at this point we may use the map rule + + align:start position:0% +at this point we may use the map rule + + + align:start position:0% +at this point we may use the map rule +and come up with an estimate which is + + align:start position:0% +and come up with an estimate which is + + + align:start position:0% +and come up with an estimate which is +the value of theta which is the more + + align:start position:0% +the value of theta which is the more + + + align:start position:0% +the value of theta which is the more +likely one and then we can continue + + align:start position:0% +likely one and then we can continue + + + align:start position:0% +likely one and then we can continue +exactly as in the case of discrete + + align:start position:0% +exactly as in the case of discrete + + + align:start position:0% +exactly as in the case of discrete +measurements of discrete observations + + align:start position:0% +measurements of discrete observations + + + align:start position:0% +measurements of discrete observations +and talk about conditional probabilities + + align:start position:0% +and talk about conditional probabilities + + + align:start position:0% +and talk about conditional probabilities +of error and so on now the fact that X + + align:start position:0% +of error and so on now the fact that X + + + align:start position:0% +of error and so on now the fact that X +is continuous really makes no difference + + align:start position:0% +is continuous really makes no difference + + + align:start position:0% +is continuous really makes no difference +once we arrive at this picture with the + + align:start position:0% +once we arrive at this picture with the + + + align:start position:0% +once we arrive at this picture with the +map rule we still choose the most likely + + align:start position:0% +map rule we still choose the most likely + + + align:start position:0% +map rule we still choose the most likely +value of theta and this is our estimate + + align:start position:0% +value of theta and this is our estimate + + + align:start position:0% +value of theta and this is our estimate +and we can calculate the probability of + + align:start position:0% +and we can calculate the probability of + + + align:start position:0% +and we can calculate the probability of +error which for the map rule would be + + align:start position:0% +error which for the map rule would be + + + align:start position:0% +error which for the map rule would be +point for exactly the same argument as + + align:start position:0% +point for exactly the same argument as + + + align:start position:0% +point for exactly the same argument as +for the case of discrete observation + + align:start position:0% +for the case of discrete observation + + + align:start position:0% +for the case of discrete observation +supplies and shows that this conditional + + align:start position:0% +supplies and shows that this conditional + + + align:start position:0% +supplies and shows that this conditional +probability of error is smallest under + + align:start position:0% +probability of error is smallest under + + + align:start position:0% +probability of error is smallest under +the map rule and then we can continue + + align:start position:0% +the map rule and then we can continue + + + align:start position:0% +the map rule and then we can continue +similarly and talk about the overall + + align:start position:0% +similarly and talk about the overall + + + align:start position:0% +similarly and talk about the overall +probability of error which can be + + align:start position:0% +probability of error which can be + + + align:start position:0% +probability of error which can be +calculated using the total probability + + align:start position:0% +calculated using the total probability + + + align:start position:0% +calculated using the total probability +theorem in two ways one way is to take + + align:start position:0% +theorem in two ways one way is to take + + + align:start position:0% +theorem in two ways one way is to take +the conditional probability over Ferrer + + align:start position:0% +the conditional probability over Ferrer + + + align:start position:0% +the conditional probability over Ferrer +for any given value of text and then + + align:start position:0% +for any given value of text and then + + + align:start position:0% +for any given value of text and then +average those conditional probabilities + + align:start position:0% +average those conditional probabilities + + + align:start position:0% +average those conditional probabilities +of error over all the possible choices + + align:start position:0% +of error over all the possible choices + + + align:start position:0% +of error over all the possible choices +of X because X is now continues here + + align:start position:0% +of X because X is now continues here + + + align:start position:0% +of X because X is now continues here +we're going to have an integral + + align:start position:0% +we're going to have an integral + + + align:start position:0% +we're going to have an integral +alternatively you can condition on the + + align:start position:0% +alternatively you can condition on the + + + align:start position:0% +alternatively you can condition on the +possible values of theta calculate + + align:start position:0% +possible values of theta calculate + + + align:start position:0% +possible values of theta calculate +conditional probabilities of error for + + align:start position:0% +conditional probabilities of error for + + + align:start position:0% +conditional probabilities of error for +any particular choice of theta and then + + align:start position:0% +any particular choice of theta and then + + + align:start position:0% +any particular choice of theta and then +take a weighted average of them in + + align:start position:0% +take a weighted average of them in + + + align:start position:0% +take a weighted average of them in +practice this calculation sometimes + + align:start position:0% +practice this calculation sometimes + + + align:start position:0% +practice this calculation sometimes +turns out to be the simpler one finally + + align:start position:0% +turns out to be the simpler one finally + + + align:start position:0% +turns out to be the simpler one finally +we can replicate the argument that we + + align:start position:0% +we can replicate the argument that we + + + align:start position:0% +we can replicate the argument that we +had in the discrete case since the map + + align:start position:0% +had in the discrete case since the map + + + align:start position:0% +had in the discrete case since the map +rule makes this term here as small as + + align:start position:0% +rule makes this term here as small as + + + align:start position:0% +rule makes this term here as small as +possible it is less than or equal to the + + align:start position:0% +possible it is less than or equal to the + + + align:start position:0% +possible it is less than or equal to the +probability of error that you would get + + align:start position:0% +probability of error that you would get + + + align:start position:0% +probability of error that you would get +under any other estimate or estimator + + align:start position:0% +under any other estimate or estimator + + + align:start position:0% +under any other estimate or estimator +then it follows that the integral will + + align:start position:0% +then it follows that the integral will + + + align:start position:0% +then it follows that the integral will +also be as small as possible and + + align:start position:0% +also be as small as possible and + + + align:start position:0% +also be as small as possible and +therefore the conclusion is that the + + align:start position:0% +therefore the conclusion is that the + + + align:start position:0% +therefore the conclusion is that the +overall probability of error is again + + align:start position:0% +overall probability of error is again + + + align:start position:0% +overall probability of error is again +the smallest possible when we use the + + align:start position:0% +the smallest possible when we use the + + + align:start position:0% +the smallest possible when we use the +map rule + + align:start position:0% +map rule + + + align:start position:0% +map rule +and so the map rule remains the optimal + + align:start position:0% +and so the map rule remains the optimal + + + align:start position:0% +and so the map rule remains the optimal +way of choosing between alternative + + align:start position:0% +way of choosing between alternative + + + align:start position:0% +way of choosing between alternative +hypotheses whether X is discrete or + + align:start position:0% +hypotheses whether X is discrete or + + + align:start position:0% +hypotheses whether X is discrete or +continuous \ No newline at end of file diff --git a/PK1KNojfvMQ.txt b/PK1KNojfvMQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..78d492f71fb7f478e417d2eca8f713f1c80bbbd3 --- /dev/null +++ b/PK1KNojfvMQ.txt @@ -0,0 +1,3781 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or to +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK, in that +case, let's take off. + +There's a fair +amount I'd like to do + +before the end of the term. + +First, let me quickly review +what we talked about last time. + +We talked about the +actual supernovae data, + +which gives us brightness as a +function of redshift for very + +distant objects and +produced the first discovery + +that the model is not fit very +well by the standard called + +dark matter model, which +would be this lower line. + +But it fits much better +by this lambda CDM, + +a model which involves a +significant fraction-- 0.76 was + +used here-- and significant +fraction of vacuum energy + +along with cold, dark +matter and baryons. + +And that was a model +that fit the data well. + +And this, along +with similar data + +from another group +of astronomers, + +was a big bombshell +of 1998, showing + +that the universe appears +to not be slowing down + +under the influence of gravity +but rather to be accelerating + +due to some kind of +repulsive, presumably, + +gravitational force. + +We talked about the +overall evidence + +for this idea of an +accelerating universe. + +It certainly began with +the supernovae data + +that we just talked about. + +The basic fact +that characterizes + +that data is that the most +distant supernovae are + +dimmer than you'd +expect by 20% to 30%. + +And people did cook up +other possible explanations + +for what might have made +supernovae at certain distances + +look dimmer. + +None of those really +held up very well. + +But, in addition, several other +important pieces of evidence + +came in to support this idea +of an accelerating universe. + +Most important, more +precise measurements + +of the cosmic background +radiation anisotropies came in. + +And this pattern +of antisotropies + +can be fit to a +theoretical model, which + +includes all of the parameters +of cosmology, basically, + +and turns out to give a very +precise setting for essentially + +all the parameters of cosmology. + +They now really all have their +most precise values coming out + +of these CMB measurements. + +And the CMB measurements +gave a value + +of omega [? vac ?], which +is very close to what we'll + +get from the supernovae, +which makes it all + +look very convincing. + +And furthermore, the +cosmic background radiation + +shows that omega total is +equal to 1 to about 1/2% + +accuracy, which is very hard +to account for if one doesn't + +assume that there's a +very significant amount + +of dark energy. + +Because there just +does not appear + +to be nearly enough of anything +else to make omega equal to 1. + +And finally, we pointed out +that this vacuum energy also + +improves the age calculations. + +Without vacuum energy, +we tend to define + +that the age of the universe +as calculated from the Big Bang + +theory always ended up +being a little younger + +than the ages of the oldest +stars, which didn't make sense. + +But with the vacuum +energy, that changes + +the cosmological calculation of +the age producing older ages. + +So with vacuum energy of the +sort that we think exists, + +we get ages like 13.7 +or 13.8 billion years. + +And that's completely +consistent with what + +we think about the ages +of the oldest stars. + +So everything fits together. + +So by now, I would say that +with these three arguments + +together, essentially, +everybody is convinced + +that this acceleration is real. + +I do know a few people +who aren't convinced, + +but they're oddballs. + +Most of us are convinced. + +And the simplest explanation +for this dark energy + +is simply vacuum energy. + +And every measurement +that's been made so far + +is consistent with the +idea of vacuum energy. + +There is still an +alternative possibility + +which is called +quintessence, which + +would be a very slowly +evolving scalar field. + +And it would show up, because +you would see some evolution. + +And so far nobody has +seen any evolution + +of the amount of dark +energy in the universe. + +So that's basically +where things stand as far + +as the observations of +acceleration of dark energy. + +Any questions about that? + +OK, next, we went on to talk +about the physics of vacuum + +energy or a +cosmological constant. + +A cosmological constant +and vacuum energy + +are really synonymous. + +And they're related +to each other + +by the energy +entering the vacuum + +being equal to this expression, +where lambda is what Einstein + +originally called the +cosmological constant + +and what we still call +the cosmological constant. + +We discussed the fact +that there are basically + +three contributions +in a quantum field + +theory to the +energy of a vacuum. + +We do not expect it to +be zero, because there + +are these complicated +contributions. + +There are, first of all, +the quantum fluctuations + +of the photon and +other Bosonic fields, + +Bosonic fields +meaning particles that + +do not obey the Pauli +exclusion principle. + +And that gives us a +positive contribution + +to the energy, which +is, in fact, divergent. + +It diverges because every +standing wave contributes. + +And there's no lower bound to +the wavelength of a standing + +wave. + +So by considering shorter +and shorter wavelengths, + +one gets larger and +larger contributions + +to this vacuum energy. + +And in the quantum field +theory, it's just unbounded. + +Similarly, there are +quantum fluctuations + +to other fields like +the electron field + +which is a Fermionic +field, a field that + +describes a particle that obeys +the Pauli exclusion principle. + +And those fields behave +somewhat differently. + +Like the photon, the +electron is viewed + +as the quantum +excitation of this field. + +And that turns out to be by +far, basically, the only way we + +know to describe +relativistic particles + +in a totally consistent way. + +In this case, again, +the contribution + +to the vacuum +energy is divergent. + +But in this case, it's +negative and divergent, + +allowing possibilities of +some kind of cancellation, + +but no reason that +we know of why + +they should cancel each other. + +They seem to just be +totally different objects. + +And, finally, there +are some fields + +which have nonzero +values in the vacuum. + +And, in particular, the Higgs +field of the standard model + +is believed to have a nonzero +value even in the vacuum. + +So this is the basic story. + +We commented that if we +cut off these infinities + +by saying that we don't +understand things at very, very + +short wavelengths, at +least one plausible cut off + +would be the Planck scale, +which is the scale associated + +with where we think quantum +gravity becomes important. + +And if we cut off at +this Planck scale, + +the energies become +finite but still too large + +compared to what we observe +by more than 120 orders + +of magnitude. + +And on the homework set +that's due next Monday, + +you'll be calculating +this number for yourself. + +It's a little bit more than +120 orders of magnitude. + +So it's a colossal failure +indicating that we really + +don't understand what controls +the value of this vacuum + +energy. + +And I think I +mentioned last time, + +and I'll mention it a +little more explicitly + +by writing it on +the transparency + +this time, that the situation +is so desperate in that we've + +had so much trouble trying to +find any way of explaining why + +the vacuum energy should be so +small that it has become quite + +popular to accept the +possibility, at least, + +that the vacuum energy is +determined by what is called + +the anthropic +selection principal + +or anthropic selection effect. + +And Steve Weinberg +was actually one + +of the first people who +advocated this point of view. + +I'm sort of a recent convert +to taking this point of view + +seriously. + +But the idea is +that there might be + +more than one possible +type of vacuum. + +And, in fact, string +theory comes in here + +in an important way. + +String theory seems +to really predict + +that there's a colossal number +of different types of vacuum, + +perhaps 10 to the 500 different +types of vacuum or more. + +And each one would have +its own vacuum energy. + +So with that many, some of them +would have a, by coincidence, + +near perfect +cancellation between + +the positive and negative +contributions producing + +a net vacuum energy that +could be very, very small. + +But it would be a tiny fraction +of all of the possible vauua, + +a fraction like 10 +to the minus 120, + +since we have 120 +orders of magnitude + +mismatch of these ranges. + +So you would still have to +press yourself to figure out + +what would be the explanation +why we should be living + +in such an atypical vacuum. + +And the proposed answer is that +it's anthropically selected, + +where anthropic means +having to do with life. + +Whereas, the claim is +made that life only + +evolves in vacuua which +have incredibly small vacuum + +energies. + +Because if the vacuum energy is +much larger, if it's positive, + +it blows the universe apart +before structures can form. + +And it it's negative, +it implodes the universe + +before there's time +for structures to form. + +So a long-lived universe +requires a very small vacuum + +energy density. + +And the claim is that +those are the only kinds + +of universes that support life. + +So we're here because it's +the only kind of universe + +in which life can +exist is the claim. + +Yes? + +AUDIENCE: So, different +types of energies, + +obviously, affect the +acceleration rate and stuff + +of the universe. + +But do they also affect, in any +way, the fundamental forces, + +or would those be the +same in all of the cases? + +PROFESSOR: OK, the question +is, would the different kinds + +of vacuum affect the kinds +of fundamental forces + +that exist besides the force +of the cosmological constant + +on the acceleration of +the universe itself? + +The answer is, yeah, it would +affect really everything. + +These different vacuua would be +very different from each other. + +They would each have +their own version + +of what we call the standard +model of particle physics. + +And that's because the standard +model of particle physics + +would be viewed as +what happens when + +you have small perturbations +about our particular type + +of vacuum. + +And with different +types of vacuum + +you get different time +types of small perturbations + +about those vaccua. + +So the physics really could +be completely different in all + +the different vacuua that +string theory suggests exist. + +So the story here, +basically, is a big mystery. + +Not everybody accepts +these anthropic ideas. + +They are talked about. + +At almost any +cosmology conference, + +there will be some session where +people talk about these things. + +They are widely +discussed but by no means + +completely agreed upon. + +And it's very much +an open question, + +what it is that explains +the very small vacuum energy + +density that we observe. + +OK, moving on, in +the last lecture + +I also gave a quick historical +overview of the interactions + +between Einstein +and Friedmann, which + +I found rather interesting. + +And just a quick summary here, +in 1922 June 29, to be precise, + +Alexander Friedmann's first +paper about the Friedmann + +equations and the dynamical +model of the universe + +were received at [INAUDIBLE]. + +Einstein learned about it +and immediately decided + +that it had to be wrong and +fired off a refutation claiming + +that Friedmann had gotten +his equations wrong. + +And if he had gotten +them right, he + +would have discovered that +rho dot, the rate of change + +of the energy density, +had to be zero + +and that there was nothing but +the static solution allowed. + +Einstein then met a friend +of Friedmann's Yuri Krutkov + +at a retirement lecture +by Lawrence in Leiden + +the following spring. + +And Krutkov convinced +Einstein that he + +was wrong about +this calculation. + +Einstein had also +received a letter + +from Friedmann, +which he probably + +didn't read until this +time, but the letter + +was apparently also convincing. + +So Einstein did finally retract. + +And at the end of May +1923, his refraction + +was received at +Zeitschrift fur Physik. + +And another interesting +fact about that + +is that the original handwritten +draft of that retraction + +still exists. + +And it had the curious +comment, which was crossed out, + +where Einstein suggested that +the Friedmann solutions could + +be modified by the phrase, +"a physical significance + +can hardly be ascribed to them." + +But at the last minute, +apparently, Einstein + +decided he didn't really +have a very good foundation + +for that statement +and crossed it out. + +So I like the +story, first of all, + +because it illustrates +that we're not + +the only people +who make mistakes. + +Even great physicists +like Einstein + +make really silly mistakes. + +It really was just a +dumb calculational error. + +And it also, I think, +points out how important + +it is not to allow +yourself to be caught + +in the grip of some firm idea +that you cease to question, + +which apparently +is what happened + +to Einstein with his belief +that the universe was static. + +He was so sure that +the universe was + +static that he very quickly +looked at Friedmann's paper + +and reached the incorrect +conclusion that Friedmann + +had gotten his calculus wrong. + +In fact, it was Einstein +who got it wrong. + +So that summarizes +the last lecture. + +Any further questions? + +OK, in that case, I think +I am done with that. + +Yeah, that comes later. + +OK, what I want to +do next is to talk + +about two problems associated +with the conventional cosmology + +that we've been learning +about and, in particular, + +I mean cosmology +without inflation, + +which we have not +learned about yet. + +So I am talking +about the cosmology + +that we've learned about so far. + +So there are a total +of three that I + +want to discuss +problems associated + +with conventional cosmology +which serve as motivations + +for the inflationary +modification that, I think, + +you'll be learning about +next time from Scott Hughes. + +But today I want to +talk about the problems. + +So the first of 3 is sometimes +called the homogeneity, + +or the horizon problem. + +And this is the problem +that the universe + +is observed to be +incredibly uniform. + +And this uniformity +shows up most clearly + +in the cosmic microwave +background radiation, + +where astronomers have now made +very sensitive measurements + +of the temperature as a +function of angle in the sky. + +And it's found that that +radiation in uniform to one + +part in 100,000, +part in 10 to the 5. + +Now, the CMB is +essentially a snapshot + +of what the universe looked +like at about 370,000 years + +after the Big Bang at the +time that we call t sub + +d, the time of decoupling. + +Yes? + +AUDIENCE: This measurement, +the 10 to the 5, + +it's not a limit +that we've reached + +measurement technique-wise? + +That's what it actually +is, [INAUDIBLE]? + +PROFESSOR: Yes, I was +going to mention that. + +We actually do see fluctuations +at the level of one part in 10 + +to the five. + +So it's not just a limit. + +It is an actual observation. + +And what we interpret is +that the photons that we're + +seeing in the CMB have been +flying along on straight lines + +since the time of decoupling. + +And therefore, what +they show us really + +is an image of what +the universe look + +like at the time of decoupling. + +And that image is an image +of the universe which + +is almost a perfectly smooth +mass density and a perfectly + +smooth temperature-- +it really is just + +radiation-- but tiny +ripples superimposed + +on top of that uniformity +where the ripples have + +an amplitude of order +of 10 to the minus 5. + +And those ripples are +important, because we + +think that those are the +origin of all structure + +in the universe. + +The universe is +gravitationally unstable + +where there's a positive +ripple making the mass density + +slightly higher than average. + +That creates a slightly +stronger than average + +gravitational field +pulling in extra matter, + +creating a still stronger +gravitational field. + +And the process cascades +until you ultimately + +have galaxies and +clusters of galaxies + +and all the complexity +in the universe. + +But it starts from these +seeds, these minor fluctuations + +at the level of one +part in 10 to the five. + +But for now we want +to discuss is simply + +the question of how +did we get so uniform. + +We'll talk about how the +non-uniformities arise later + +in the context of inflation. + +The basic picture is +that we are someplace. + +I'll put us here in +a little diagram. + +We are receiving photons, +say, from opposite directions + +in the sky. + +Those little arrows represent +the incoming patterns + +of two different +CMB photons coming + +from opposite directions. + +And what I'm interested +in doing to understand + +the situation with regard +to this uniformity is I'm + +interested in tracing +these photons back + +to where they originated +at time t sub d. + +And I want to do +that on both sides. + +But, of course, it's symmetric. + +So I only need to +do one calculation. + +And what I want +to know is how far + +apart were these two points. + +Because I want to explore +the question of whether + +or not this uniformity +in temperature + +could just be mundane. + +If you let any object +sit for a long time, + +it will approach a +uniform temperature. + +That's why pizza gets cold when +you take it out of the oven. + +So could that be responsible +for this uniformity? + +And what we'll see +is that it cannot. + +Because these two points +are just too far apart + +for them to come in +to thermal equilibrium + +by ordinary thermal +equilibrium processes + +in the context of the +conventional big bang theory. + +So we want to calculate how +far apart these points were + +at the time of emission. + +So what do we know? + +We know that the temperature +at the time of decoupling + +was about 3,000 +Kelvin, which is really + +where we started with our +discussion of decoupling. + +We did not do the +statistical mechanics + +associated with this statement. + +But for a given density, +you can calculate + +at what temperature +hydrogen ionizes. + +And for the density that we +expect for the early universe, + +that's the temperature at +which the ionization occurs. + +So that's where +decoupling occurs. + +That's where it becomes neutral +as the universe expands. + +We also know that +during this period, aT, + +the scale factor +times the temperature + +is about equal to +a constant, which + +follows as a consequence +of conservation of entropy, + +the idea that the universe +is near thermal equilibrium. + +So the entropy does not change. + +Then we can calculate +the z for decoupling, + +because it would just be the +ratio of the temperatures. + +It's defined by the ratio +of the scale factors. + +This defines what you mean +by 1 plus z decoupling. + +But if aT is about +equal to a constant, + +we can relate this to the +temperatures inversely. + +So the temperature of decoupling +goes in the numerator. + +And the temperature today +goes into the denominator. + +And, numerically, +that's about 1,100. + +So the z of the cosmic +background radiation + +is about 1,100, vastly larger +than the red shifts associated + +with observations of +galaxies or supernovae. + +From the z, we can calculate +the physical distance today + +of these two locations, because +this calculation we already + +did. + +So I'm going to call l sub p +the physical distance between us + +and the source of +this radiation. + +And its value today-- I'm +starting with this formula + +simply because we +already derived it + +on a homework set-- it's 2c h +naught inverse times 1 minus 1 + +over the square +root of 1 plus z. + +And this calculation was done +for a flat matter dominated + +universe, flat matter dominated. + +Of course, that's +only an approximation, + +because we know our +real universe was matter + +dominated at the +start of this period. + +But it did not remain +matter dominated + +through to the present at +about 5,000 or 6,000 years ago. + +We switched to a situation where +the dark energy is actually + +larger than the +non-relativistic matter. + +So we're ignoring +that effect, which + +means we're only going to +get an approximation here. + +But it will still be easily +good enough to make the point. + +For a z this large, this +factor is a small correction. + +I think this ends up +being 0.97, or something + +like that, very close to 1, +which means what we're getting + +is very close to 2c h +naught inverse, which + +is the actual horizon. + +The horizon corresponds +to z equals infinity. + +If you think about +it, that's what + +you expect the horizon to be. + +It corresponds to +infinite red shift. + +And you don't see +anything beyond that. + +So if we take the best value +we have for h naught, which I'm + +taking from the +Planck satellite, 57.3 + +kilometers per second +per megaparsec, + +and put that and the value +for z into this formula, + +we get l sub p of t naught +of 28.2 billion light years + +times 10 to the 9 light year. + +So it's of course larger +than ct as we expect. + +It's basically 3ct for a +matter dominated universe. + +And 3ct is the same +as 2ch 0 inverse. + +Now, what we want +to know, though, + +is how far away was this +when the emission occurred, + +not the present distance. + +We looked at the +present distance + +simply because we had a formula +for it from our homework set. + +But we know how to extrapolate +that backwards, l sub + +t at time t sub d. + +Distances that are fixed +in co-moving space, + +which these are, +are just stretched + +with the scale factor. + +So this will just +be the scale factor + +at the time of decoupling +divided by the scale factor + +today times the +present distance. + +And this is, again, given by +this ratio of temperatures. + +So it's 1 over +1,100, the inverse + +of what we had over there. + +So the separation +at this early time + +is just 1,100 times smaller +than the separation today. + +And that can be +evaluated numerically. + +And it gives us 2.56 times +10 to the seven light years, + +so 25 million light years. + +Now, the point is that +that's significantly larger + +than the horizon +distance at that time. + +And remember, the +horizon distance + +is the maximum possible +distance that anything + +can travel limited +by the speed of light + +from the time of the +big bang up to any given + +point in cosmic history. + +So the horizon at +time t sub d is just + +given by the simple formula +that the physical value + +of the horizon +distance, l sub h phys, + +l sub horizon physical, at +time t sub d is just equal to, + +for a matter dominated +universe, 3c times t sub d. + +And that we can evaluate, +given what we have. + +And it's about 1.1 times 10 to +the sixth light years, which + +is significantly less than +2.56 times 10 to the seven + +light years. + +And, in fact, the ratio of +the two, given these numbers, + +is that l sub p of t sub d +over l sub h is also of t sub + +d is about equal to 23, +just doing the arithmetic. + +And that means if we go +back to this picture, + +these two points of emission +were separated from each other + +by about 46 horizon distances. + +And that's enough to +imply that there's no way + +that this point could have known +anything whatever about what + +was going on at this point. + +Yet somehow they knew to +emit these two photons + +at the same time at +the same temperature. + +And that's the mystery. + +One can get around this +mystery if one simply + +assumes that the singularity +that created all of this + +produced a perfectly homogeneous +universe from the very start. + +Since we don't understand +that singularity, + +we're allowed to attribute +anything we want to it. + +So in particular, you can +attribute perfect homogeneity + +to the singularity. + +But that's not really +an explanation. + +That's an assumption. + +So if one wants to be able +to explain this uniformity, + +then one simply cannot do it +in the context of conventional + +cosmology. + +There's just no +way that causality, + +the limit of the speed of +light, allows this point + +to know anything about what's +going on at that point. + +Yes? + +AUDIENCE: How could a +singularity not be uniform? + +Because If it had +non-uniform [INAUDIBLE], + +then not be singular? + +PROFESSOR: OK, the +question is how + +can a singularity +not be uniform? + +The answer is, +yes, singularities + +can not be uniform. + +And I think the way one can +show that is a little hard. + +But you have to imagine a +non-uniform thing collapsing. + +And then it would just be +the time reverse, everything + +popping out of the singularity. + +So you can ask, does +a non-uniform thing + +collapse to a singularity? + +And the answer to that +question is not obvious + +and really was debated +for a long time. + +But there were theorems +proven by Hawking and Penrose + +that indeed not only do the +homogeneous solutions that we + +look at collapse but in +homogeneous solutions also + +collapse to singularities. + +So a singularity does +not have to be uniform. + +OK, so this is the story +of the horizon problem. + +And as I said, you +can get around it + +if you're willing to just +assume that the singularity was + +homogeneous. + +But if you want to have a +dynamical explanation for how + +the uniformity of the +universe was established, + +then you need some model +other than this conventional + +cosmological model that +we've been discussing. + +And inflation will +be such a twist + +which will allow a +solution to this problem. + +OK, so if there +are no questions, + +no further questions, +we'll go on + +to the next problem +I want to discuss, + +which is of a similar nature +in that you can get around it + +by making strong assumptions +about the initial singularity. + +But if one wants, +again, something + +you can put your hands on, +rather than just an assumption + +about a singularity, then +inflation will do the job. + +But you cannot solve the +problem in the context + +of a conventional +big bang theory, + +because the mechanics of the +conventional big bang theory + +are simply well-defined. + +So what I want to +talk here is what + +is called the flatness +problem, where flatness + +is in the sense of +Omega very near 1. + +And this is +basically the problem + +of why is Omega today +somewhere near 1? + +So Omega naught is the +present value of Omega, + +why is it about equal to 1? + +Now, what do we +know first of all + +about it being about equal to 1? + +The best value from +the Planck group, + +this famous Planck +satellite that I've + +been quoting a lot +of numbers from-- + +and I think in all cases, +I've been quoting numbers + +that they've established +combining their own data + +with some other pieces of data. + +So it's not quite +the satellite alone. + +Although, they do give numbers +for the satellite alone + +which are just a little +bit less precise. + +But the best number they give +for Omega naught is minus + +0.0010 plus or minus 0.0065. + +Oops, I didn't put +enough zeroes there. + +So it's 0.0065 is the error. + +So the error is just a +little bit more than a half + +of a percent. + +And as you see, consistent +with-- I'm sorry, + +I meant this to be 1. + +Hold on. + +This is Omega naught minus 1 +that I'm writing a formula for. + +So Omega naught is very +near 1 up to that accuracy. + +What I want to emphasize in +terms of this flatness problem + +is that you don't need to know +that Omega naught is very, very + +close to 1 today, +which we now do know. + +But even back when inflation +was first invented around 1980, + +in circa 1980 we +certainly didn't + +know that Omega was so +incredibly close to 1. + +But we did know that +Omega was somewhere + +in the range of about +0.1 and 0.2, which is not + +nearly as close to 1 as what we +know now, but still close to 1. + +I'll argue that the +flatness problem exists + +for these numbers +almost as strongly + +as it exists for those numbers. + +Differ, but this is still a +very, very strong argument + +that even a number like +this is amazingly close to 1 + +considering what +you should expect. + +Now, what underlies this is the +expectations, how close should + +we expect Omega to be to 1? + +And the important +underlying piece + +of dynamics that controls this +is the fact that Omega equals 1 + +is an unstable +equilibrium point. + +That means it's like a +pencil balancing on its tip. + +If Omega is exactly +equal to 1, that + +means you have a flat universe. + +And an exactly +flat universe will + +remain an exactly +flat universe forever. + +So if Omega is +exactly equal to 1, + +it will remain exactly +equal to 1 forever. + +But if Omega in +the early universe + +were just a tiny +bit bigger than 1-- + +and we're about +to calculate this, + +but I'll first qualitatively +describe the result-- + +it would rise and would +rapidly reach infinity, + +which is what it reaches if +you have a closed universe when + +a closed universe +reaches its maximum size. + +So Omega becomes infinity and +then the universe recollapses. + +So if Omega were +bigger than 1, it + +would rapidly approach infinity. + +If Omega in the early universe +were just a little bit less + +than 1, it would rapidly +trail off towards 0 + +and not stay 1 for +any length of time. + +So the only way to +get Omega near 1 today + +is like having a pencil +that's almost straight + +up after standing there +for 1 billion years. + +It'd have to have +started out incredibly + +close to being straight up. + +It has to have +started out incredibly + +close to Omega equals 1. + +And we're going to +calculate how close. + +So that's the set-up. + +So the question we want to +ask is how close did Omega + +have to be to 1 in +the early universe + +to be in either one of +these allowed ranges today. + +And for the early +universe, I'm going + +to take t equals one second +as my time at which I'll + +do these calculations. + +And, historically, that's +where this problem was first + +discussed by Dicke and +Peebles back in 1979. + +And the reason why one +second was chosen by them, + +and why it's a sensible time +for us to talk about as well, + +is that one second +is the beginning + +of the processes of +nucleosynthesis, which you've + +read about in +Weinberg and in Ryden, + +and provides a real test of +our understanding of cosmology + +at those times. + +So we could say that we +have real empirical evidence + +in the statement that the +predictions of the chemical + +elements work. + +We could say that we have +real empirical evidence + +that our cosmological model +works back to one second + +after the Big Bang. + +So we're going to +choose one second + +for the time at which we're +going to calculate what Omega + +must've been then for it to +be an allowed range today. + +How close must Omega have been +to 1 at t equals 1 second? + +Question mark. + +OK, now, to do this +calculation, you + +don't need to know anything +that you don't already know. + +It really follows as a +consequence of the Friedmann + +equation and how matter and +temperature and so on behave + +with time during radiation +in matter dominated eras. + +So we're going to start with +just the plain old first order + +Fiedmann equation, h squared +is equal to 8 pi over 3 g Rho + +minus kc squared +over a squared, which + +you have seen many, many +times already in this course. + +We can combine that +with other equations + +that you've also +seen many times. + +The critical density is just +the value of the density + +when k equals 0. + +So you just solve +this equation for Rho. + +And you get 3h +squared over h pi g. + +This defines the +critical density. + +It's that density which makes +the universe flat, k equals 0. + +And then our standard +definition is + +that Omega is just defined to be +the actual mass density divided + +by the critical mass density. + +And Omega will be the quantity +we're trying to trace. + +And we're also going +to make use of the fact + +that during the era that +we're talking about, + +at is essentially +equal to a constant. + +It does change a little bit +when electron and positron + +pairs freeze out. + +It changes by a +factor of something + +like 4/11 to the 1/3 power +or something like that. + +But that power will be of +order one for our purposes. + +But I guess this is +a good reason why + +I should put a +squiggle here instead + +of an equal sign as an +approximate equality, + +but easily good enough +for our purposes, + +meaning the corrections +of order one. + +We're going to +see the problem is + +much, much bigger +than order one. + +So a correction of order +one doesn't matter. + +Now, I'm going to start by using +the Planck satellite limits. + +And at the end, I'll just make +a comment about the circa 1980 + +situation. + +But if we look at the +Planck limits-- I'm sorry. + +Since I'm going to write an +equation for a peculiar looking + +quantity, I should +motivate the peculiar + +looking quantity first. + +It turns out to be useful +for these purposes. + +And this purpose +means we're trying + +to track how Omega +changes with time. + +It turns out to be useful +to reshuffle the Friedmann. + +And it is just an +algebraic reshuffling + +of the Friedmann equation +and the definitions + +that we have here. + +We can rewrite the +Friedmann equation + +as Omega minus 1 over Omega +is equal to a quantity called + +a times the temperature +squared over Rho. + +Now, the temperature didn't even +occur in the original equation. + +So things might look a +little bit suspicious. + +I haven't told +you what a is yet. + +a is 3k c squared over 8 +pi g a squared t squared. + +So when you put the a into this +equation, the t squares cancel. + +So the equation doesn't +really have any temperature + +dependence. + +But I factored things +this way, because we + +know that at is +approximately a constant. + +And that means that this +capital a, which is just + +other things which +are definitely + +constant times, a square t +square in the denominator, + +this a is approximately +a constant. + +And you'll have to +check me at home + +that this is exactly equivalent +to the original Friedmann + +equation, no approximations +whatever, just substitutions + +of Omega and the +definition of Rho sub c. + +So the nice thing about +this is that we can read off + +the time dependence +of the right-hand side + +as long as we know the time +dependence in the temperature + +and the time dependence +of the energy density. + +And we do for matter dominated +and radiation dominated eras. + +So this, essentially, +solves the problem for us. + +And now it's really +just a question + +of looking at the +numerics that follow + +as a consequence +of that equation. + +And this quantity, +we're really interested + +in just Omega minus 1. + +The Friedmann equation gave +us the extra complication + +of an Omega in the denominator. + +But in the end, we're going +to be interested in cases + +where Omega is very, +very close to 1. + +So the Omega in the denominator +we could just set equal to one. + +And it's the Omega minus +1 in the numerator that + +controls the value of +the left-hand side. + +So if we look at these Planck +limits, we could ask how big + +can that be? + +And it's biggest if the error +occurs on the negative side. + +So it contributes to +this small mean value + +which is slightly negative. + +And it gives you 0.0075 +for Omega minus 1. + +And then if you put that in the +numerator and the same thing + +in the denominator, you +get something like 0.0076. + +But I'm just going +to use the bound + +that Omega naught minus 1 +over Omega is less than 0.01. + +But the more accurate +thing would be 0.076. + +But, again, we're not really +interested in small factors + +here. + +And this is a one signa error. + +So the actual error could +be larger than this, + +but not too much +larger than this. + +So I'm going to divide the time +interval between one second + +and now up into two integrals. + +From one second to +about 50,000 years, + +the universe was +radiation dominated. + +We figured out earlier that the +matter to radiation equality + +happens at about 50,000 years. + +I think we may have gotten +47,000 years or something + +like that when we calculated it. + +So for t equals 1 +second to-- I'm sorry, + +I'm going to do it +the other order. + +I'm going to start with the +present and work backwards. + +So for t equals 50,000 +years to the present, + +the universe is +matter dominated. + +And the next thing +is that we know + +how mattered dominated +universe's behave. + +We don't need to recalculate it. + +We know that the scale +factor for a matter + +dominated flat universe goes +like t to the 2/3 power, + +I should have a +portionality sign here. + +a of t is proportional +to t to 2/3. + +And it's fair to assume +flat, because we're always + +going to be talking about +universes that are nearly flat + +and becoming more and more +flat as we go backwards, + +as we'll see. + +And again, this isn't an +approximate calculation. + +One could do it more +accurately if one wanted to. + +But there's really no need +to, because the result + +will be so extreme. + +The temperature behaves like +one over the scale factor. + +And that will be true for +both the matter dominated + +and a radiation +dominated universe. + +And the energy density +will be proportional to one + +over the scale factor cubed. + +And then if we put those +together and use the formula + +on the other blackboard and ask +how Omega minus 1 over Omega + +behaves, it's proportional +to the temperature squared + +divided by the energy density. + +The temperature +goes like 1 over a. + +So temperature squared +goes like 1 over a squared. + +But Rho in the denominator +goes like 1 over a cubed. + +So you have 1 over a squared +divided by 1 over a cubed. + +And that means it just goes +like a, the scale factor itself. + +So Omega minus 1 over +Omega is proportional to a. + +And that means it's +proportional to t to the 2/3. + +So that allows us to +write down an equation, + +since we want to +relate everything + +to the value of Omega +minus 1 over Omega today, + +we can write Omega +minus 1 over Omega + +at 50,000 years is about equal +to the ratio of the 2 times + +the 50,000 years and today, +which is 13.8 billion years, + +to the 2/3 power +since Omega minus 1 + +grows like t to the 2/3. + +I should maybe have +pointed out here, + +this telling us that Omega +minus 1 grows with time. + +That's the important feature. + +It grows t to the 2/3. + +So the value at 50,000 +years is this ratio + +to the 2/3 power times +Omega minus 1 over Omega + +today, which I can +indicate just by putting + +subscript zeros on my Omegas. + +And that makes it today. + +And I've written this as +a fraction less than one. + +This says that Omega +minus 1 over Omega + +was smaller than it +is now by this ratio + +to the 2/3 power, which +follows from the fact + +that Omega minus 1 over Omega +grows like t to the 2/3. + +OK, we're now halfway there. + +And the other half is similar, +so it will go quickly. + +We now want to go +from 50,000 years + +to one second using the +fact that during that era + +the universe was +radiation dominated. + +So for t equals 1 +second to 50,000 years, + +the universe is +radiation dominated. + +And that implies +that the scale factor + +is proportional to t to the 1/2. + +The temperature is, +again, proportional to 1 + +over the scale factor. + +That's just +conservation of entropy. + +And the energy density goes +one over the scale factor + +to the fourth. + +So, again, we go +back to this formula + +and do the corresponding +arithmetic. + +Temperature goes like 1 over a. + +Temperature squared goes +like 1 over a squared. + +That's our numerator. + +This time, in the +denominator, we + +have Rho, which goes like +one over a to the fourth. + +So we have 1 over a +squared divided by 1 + +over a to the fourth. + +And that means it +goes like a squared. + +So we get Omega +minus 1 over Omega + +is proportional to a squared. + +And since goes like +the square root of t, + +a squared goes like t. + +So during the +radiation dominated era + +this diverges even +a little faster. + +PROFESSOR: It goes like +t, rather than like t + +to the 2/3, which is a +slightly slower growth. + +And using this fact, we +can put it all together now + +and say that Omega minus +1 over Omega at 1 second + +is about equal to 1 +second over 50,000 + +years to the first +power-- this is going + +like the first +power of t-- times + +the value of Omega minus 1 +over Omega at 50,000 years. + +And Omega at 50,000 years, +we can put in that equality + +and relate everything +to the present value. + +And when you do that, +putting it all together, + +you ultimately find that Omega +minus 1 in magnitude at t + +equals 1 second is less than +about 10 to the minus 18. + +This is just putting +together these inequalities + +and using the Planck value for +the present value, the Planck + +inequality. + +So then 10 to the minus 18 +is a powerfully small number. + +What we're saying is that to +be in the allowed range today, + +at one second +after the Big Bang, + +Omega have to have +been equal to 1 + +in the context of this +conventional cosmology + +to an accuracy of +18 decimal places. + +And the reason +that's a problem is + +that we don't know +any physics whatever + +that forces Omega +to be equal to 1. + +Yet, somehow Omega +apparently has + +chosen to be 1 to an accuracy +of 18 decimal places. + +And I mention that the argument +wasn't that different in 1980. + +In 1980, we only knew +this instead of that. + +And that meant that instead +of having 10 to the minus 2 + +on the right-hand side +here, we would have had 10 + +differing by three +orders of magnitude. + +So instead of getting +10 to the minus 18 here, + +we would have gotten +10 to minus 15. + +And 10 to minus 15 is, I +guess, a lot bigger than 10 + +to minus 18 by a +factor of 1,000. + +But still, it's an +incredibly small number. + +And the argument really +sounds exactly the same. + +The question is, how +did Omega minus 1 + +get to be so incredibly small? + +What mechanism was there? + +Now, like the +horizon problem, you + +can get around it by +attributing your ignorance + +to the singularity. + +You can say the +universe started out + +with Omega exactly equal +to 1 or Omega equal to 1 + +to some extraordinary accuracy. + +But that's not really +an explanation. + +It really is just a +hope for an explanation. + +And the point is +that inflation, which + +you'll be learning about +in the next few lectures, + +provides an actual explanation. + +It provides a +mechanism that drives + +the early universe towards Omega +equals 1, thereby explaining + +why the early universe +had a value of Omega + +so incredibly close to 1. + +So that's what we're going +to be learning shortly. + +But at the present time, +the takeaway message + +is simply that for Omega to +be in the allowed range today + +it had to start out unbelievably +close to 1 at, for example, t + +equals 1 second. + +And within +conventional cosmology, + +there's no explanation for +why Omega so close to 1 + +was in any way preferred. + +Any questions about that? + +Yes? + +AUDIENCE: Is there +any heuristic argument + +that omega [INAUDIBLE] +universe has total energy zero? + +So isn't that, at +least, appealing? + +PROFESSOR: OK the question +is, isn't it maybe appealing + +that Omega should equal +1 because Omega equals + +1 is a flat universe, +which has 0 total energy? + +I guess, the point is that +any closed universe also + +has zero total energy. + +So I don't think Omega +equals 1 is so special. + +And furthermore, if you look at +the spectrum of possible values + +of Omega, it can be positive-- +I'm sorry, not with Omega. + +Let me look at the +curvature itself, little k. + +Little k can be +positive, in which case, + +you have a closed universe. + +It can be negative, +in which case, + +you have an open universe. + +And only for the one +special case of k + +equals 0, which really is one +number in the whole real line + +of possible numbers, do +you get exactly flat. + +So I think from that +point of view flat looks + +highly special and not at +all plausible as what you'd + +get if you just grabbed +something out of a grab bag. + +But, ultimately, I think there's +no way of knowing for sure. + +Whether or not Omega equals 1 +coming out of the singularity + +is plausible really depends +on knowing something about + +the singularity, which we don't. + +So you're free to speculate. + +But the nice thing +about inflation + +is that you don't +need to speculate. + +Inflation really does +provide a physical mechanism + +that we can understand +that drives Omega + +to be 1 exactly +like what we see. + +Any other questions? + +OK, in that case, +what I'd like to do + +is to move on to +problem number three, + +which is the magnetic monopole +problem, which unfortunately + +requires some background +to understand. + +And we don't have too much time. + +So I'm going to go through +things rather quickly. + +This magnetic +monopole problem is + +different from the other two +in the first two problems + +I discussed are just problems +of basic classical cosmology. + +The magnetic +monopole problem only + +arises if we believe that +physics at very high energies + +is described what are called +grand unified theories, which + +then imply that these magnetic +monopoles exist and allow us + +a root for estimating +how many of them + +would have been produced. + +And the point is +that if we assume + +that grand unified theories +are the right description + +of physics at very +high energies, then + +we conclude that far too +many magnetic monopoles would + +be produced if we had just the +standard cosmology that we've + +been talking about +without inflation. + +So that's going to be the +thrust of the argument. + +And it will all go +away if you decide + +you don't believe in grand +unified theories, which you're + +allowed to. + +But there is some evidence +for grand unified theories. + +And I'll talk about +that a little bit. + +Now, I'm not going to have +time to completely describe + +grand unified theories. + +But I will try to tell +you enough odd facts + +about grand unified theories. + +So there will be kind of +a consistent picture that + +will hang together, even though +there's no claim that I can + +completely teach you grand +unified theories in the next 10 + +minutes and then talk +about the production + +of magnetic monopoles and +those theories in the next five + +minutes. + +But that will be +sort of the goal. + +So to start with, I +mentioned that there's + +something called the +standard model of particle + +physics, which is +enormously successful. + +It's been developed +really since the 1970s + +and has not changed too +much since maybe 1975 or so. + +We have, since 1975, learned +that neutrinos have masses. + +And those can be incorporated +into the standard model. + +And that's a recent addition. + +And, I guess, in +1975 I'm not sure + +if we knew all three +generations that we now know. + +But the matter, the +fundamental particles + +fall into three +generations, these particles + +of a different type. + +And we'll talk about them later. + +But these are the quarks. + +These are the +spin-1/2 particles, + +these three columns on the left. + +On the top, we have the quarks, +up, down, charm, strange, top, + +and bottom. + +There are six different +flavors of quarks. + +Each quark, by the way, comes +in three different colors. + +The different colors +are absolutely + +identical to each other. + +There's a perfect +symmetry among colors. + +There's no perfect +symmetry here. + +Each of these quarks is a little +bit different from the others. + +Although, there are +approximate symmetries. + +And related to each +family of quarks + +is a family of +leptons, particles + +that do not undergo +strong interactions + +in the electron-like +particles and neutrinos. + +This row is the neutrinos. + +There's an electron neutrino, +a muon neutrino, and a tau + +neutrino, like +we've already said. + +And there's an electron, +a muon, and a tao, + +which I guess we've +also already said. + +So the particles on the left are +all of the spin-1/2 particles + +that exist in the standard +model of particle physics. + +And then on the right, we +have the Boson particles, + +the particles of +integer span, starting + +with the photon on the top. + +Under that in this +list-- there's + +no particular order +in here really-- is + +the gluon which is +the particle that's + +like the photon but the +particle which describes + +the strong interactions, which +are somewhat more complicated + +and electromagnetism, but still +described by spin-1 particles + +just like the photon. + +And then two other spin-1 +particles, the z0 and the w + +plus and minus, which +are a neutral particle + +and a charged +particle, which are + +the carriers of the +so-called weak interactions. + +The weak interactions +being the only + +non-gravitational interactions +that neutrinos undergo. + +And the weak interactions +are responsible + +for certain particle decays. + +For example, a neutron can +decay into a proton giving off + +also an electron-- +producing a proton, + +yeah-- charge has to be +conserved, proton is positive. + +So it's produced with +an electron and then + +an anti-electron neutrino to +balance the so-called electron + +lepton number. + +And that's a weak direction. + +Essentially, anything +that involves neutrinos + +is going to be weak interaction. + +So these are the characters. + +And there's a set +of interactions + +that go with this +set of characters. + +So we have here a +complete model of how + +elementary particles interact. + +And the model has been +totally successful. + +It actually gives +predictions that + +are consistent with every +reliable experiment that + +has been done since the +mid-1970s up to the present. + +So it's made particle +physics a bit dull + +since we have a theory that +seems to predict everything. + +But it's also a +magnificent achievement + +that we have such a theory. + +Now, in spite of the fact that +this theory is so unbelievably + +successful I don't think I know +anybody who really regards this + +as a candidate even or the +ultimate theory of nature. + +And the reason for that +is maybe twofold, first + +is that it does not +incorporate gravity, + +it only incorporates +particle interactions. + +And we know that gravity exists +and has to be put in somehow. + +And there doesn't seem to be any +simple way of putting gravity + +into this theory. + +And, secondly-- maybe there's +three reasons-- second, + +it does not include any good +candidates for the dark matter + +that we know exists +in cosmology. + +And third, excuse me-- and this +is given a lot of importance, + +even though it's an aesthetic +argument-- this model has + +something like 28 free +parameters, quantities that you + +just have to go out and measure +before you can use the model + +to make predictions. + +And a large number +of free parameters + +is associated, by theoretical +physicists, with ugliness. + +So this is considered +a very ugly model. + +And we have no real +way of knowing, + +but almost all +theoretical physicists + +believe that the +correct theory of nature + +is going to be simpler and +involve many fewer, maybe + +none at all, free knobs +that can be turned + +to produce different +kinds of physics. + +OK, what I want to +talk about next, + +leading up to grand +unified theories, + +is the notion of gauge theories. + +And, yes? + +AUDIENCE: I'm sorry, question +real quick from the chart. + +I basically heard +the explanation + +that the reason for the +short range of the weak force + +was the massive mediator that is +the cause of exponential field + +decay. + +But if the [INAUDIBLE] +is massless, + +how do we explain +that to [INAUDIBLE]? + +PROFESSOR: Right, +OK, the question + +is for those of you +who couldn't hear + +it is that the short range +of the weak interactions, + +although I didn't talk about +it, is usually explained + +and is explained by the +fact that the z and w naught + +Bosons are very heavy. + +And heavy particles +have a short range. + +But the strong interactions +seem to also have a short range. + +And yet, the gluon is +effectively massless. + +That's related to a +complicated issue which + +goes by the name of confinement. + +Although the gluon is +massless, it's confined. + +And confined means that +it cannot exist as a free + +particle. + +In some sense, the +strong interactions + +do have a long range in that +if you took a meson, which + +is made out of a quark +and an anti-quark, + +in principle, if +you pulled it apart, + +there'd be a string +of gluon force + +between the quark +and the anti-quark. + +And that would produce +a constant force + +no matter how far +apart you pulled them. + +And the only thing +that intervenes, + +and it is important +that it does intervene, + +is that if you pulled +them too far apart + +it would become +energetically favorable + +for a quark anti-quark pair +to materialize in the middle. + +And then instead of having a +quark here and an anti-quark + +here and a string +between them, you + +would have a quark here +and an anti-quark there + +and a string between them, +and an anti-quark here + +and-- I'm sorry, I +guess it's a quark here + +and an anti-quark there +and a string between those. + +And then they would +just fly apart. + +So the string can +break by producing + +quark anti-quark pairs. + +But the string can never just +end in the middle of nowhere. + +And that's the essence +of confinement. + +And it's due to the +peculiar interactions + +that these gluons +are believed to obey. + +So the gluons behave +in a way which + +is somewhat uncharacteristic +of particles. + +Except at very short distances, +they behave very much + +like ordinary particles. + +But at larger distances, +these effects of confinement + +play a very significant role. + +Any other questions? + +OK, onward, I want talk +about gauge theories, + +because gauge +theories have a lot + +to do with how one gets +into grand unified theories + +from the standard model. + +And, basically, a gauge +theory is a theory + +in which the fundamental fields +are not themselves reality. + +But rather there's a +set of transformations + +that the fields can +undergo which take you + +from one description +to an equivalent + +description of the same reality. + +So there's not a +one to one mapping + +between the fields and reality. + +There are many different +field configurations + +that correspond to +the same reality. + +And that's basically +what characterizes + +what we call a gauge theory. + +And you do know one +example of a gauge theory. + +And that's e and m. + +If e and m is expressed in terms +of the potentials Phi and A, + +you can write e in terms +of the potential that way + +and b as the curl of A, you +could put Phi and A together + +and make a four-vector +if you want + +to do things in a +Lorentz covariant way. + +And the important point, +though, whether you put them + +together or not, is +that you can always + +define a gauge transformation +depending on some arbitrary + +function Lambda, which is a +function of position and time. + +I didn't write in the +arguments, but Lambda is just + +an arbitrary function +of position and time. + +And for any Lambda you +can replace 5 by 5 prime, + +given by this line, and a by +a prime, given by that line. + +And if you go back +and compute e and b, + +you'll find that +they'll be unchanged. + +And therefore, the +physics is not changed, + +because the physics really +is all contained in e and b. + +So this gauge transformation +is a transformation + +on the fields of the theory-- +it can be written covariantly + +this way-- which leaves +the physics invariant. + +And it turns out that +all the important field + +theories that we know +of are gauge theories. + +And that's why it's +worth mentioning here. + +Now, for e and m, the gauge +parameter is just this function + +Lambda, which is a function +of position and time. + +And an important +issue is what happens + +when you combine +gauge transformations, + +because the succession +of two transformations + +had better also be a +symmetry transformation. + +So it's worth understanding +that group structure. + +And for the case of e +and m, these Lambdas + +just add if we make +successive transformations. + +And that means the +group is Abelian. + +It's commutative. + +But that's not always the case. + +Let's see, where am I going? + +OK, next slide actually +comes somewhat later. + +Let me go back to +the blackboard. + +It turns out that the important +generalization of gauge + +theories is the generalization +from Abelian gauge + +theories to non-Abelian ones, +which was done originally + +by Yang and Mills +in 1954, I think. + +And when it was first proposed, +nobody knew what to do with it. + +But, ultimately, these +non-Abelian gauge theories + +became the standard model +of particle physics. + +And in non-Abelian +gauge theories + +the parameter that describes the +gauge transformation is a group + +element, not just +something that gets added. + +And group elements +multiply, according + +to the procedures of some group. + +And in particular, +the standard model + +is built out of three groups. + +And the fact that there +are three groups not one + +is just an example +of this ugliness + +that I mentioned and is +responsible for the fact + +that there's some significant +number of parameters + +even if there were no +other complications. + +So the standard model is based +on three gauge groups, SU3, + +SU2, and U1. + +And it won't really be +too important for us + +what exactly these groups are. + +Let me just mention +quickly, SU3 is a group of 3 + +by 3 matrices which are +unitary in the sense + +that u adjoint times u is equal +to 1 and special in the sense + +that they have determinant 1. + +And the set of all +3 by 3 matrices + +have those properties +form a group. + +And that group is SU3. + +SU2 is the same +thing but replace + +the 3 in all those +sentences by 2s. + +U1 is just the group of phases. + +That is the group +of real numbers + +that could be written +as either the i phi. + +So it's just a complex number of +magnitude 1 with just a phase. + +And you can multiply those +and they form a group. + +And the standard model +contains these three groups. + +And the three groups +all act independently, + +which means that if you +know about group products, + +one can say that the full +group is the product group. + +And that just means that a full +description of a group element + +is really just a set +of an element of SU3, + +and an element of SU2, +and an element of U1. + +And if you put together three +group elements in each group + +and put them +together with commas, + +that becomes a group element +of the group SU3 cross, + +SU2 cross U1. + +And that is the gauge +group of the standard model + +of particle physics. + +OK, now grand unified theories, +a grand unified theory + +is based on the idea that +this set of three groups + +can all be embedded in +a single simple group. + +Now, simple actually has a +mathematical group theory + +meaning. + +But it also, for +our purposes, just + +means simple, which is +good enough for our brush + +through of these arguments. + +And, for example-- +and the example + +is shown a little bit in +the lecture notes that + +will be posted +shortly-- an example + +of a grand unified +theory, and indeed + +the first grand unified +theory that was invented, + +is based on the full gauge group +SU5, which is just a group of 5 + +by 5 matrices which are +unitary and have determinant 1. + +And there's an easy way to embed +SU3 and SU2 and U1 into SU5. + +And that's the way that +was used to construct + +this grand unified theory. + +One can take a 5 by 5 matrix-- +so this is a 5 by 5 matrix-- + +and one can simply take +the upper 3 by 3 block + +and put an SU3 matrix there. + +And one can take the +lower 2 by 2 block + +and put an SU2 matrix there. + +And then the U1 piece-- +there's supposed + +to be a U1 left +over-- the U1 piece + +can be obtained by giving +an overall phase to this + +and an overall phase +to that in such a way + +that the product of +the five phases is 0. + +So the determinant +has not changed. + +So one can put an e to the i2 +Phi there and a factor of e + +to the minus i3 Phi +there for any Phi. + +And then this Phi +becomes the description + +of the U1 piece of +this construction. + +So we can take an arbitrary +SU3 matrix, and arbitrary SU2 + +matrix, and an arbitrary +U1 value expressed by Phi + +and put them together +to make an SU5 matrix. + +And if you think about +it, the SU3 piece + +will commute with the SU2 +piece and with the U1 piece. + +These three pieces will all +commute with each other, + +if you think about +how multiplication + +works with this construction. + +So it does exactly what we want. + +It decomposes SU5. + +So it has a subgroup of +SU3 cross SU2 across U1. + +And that's how the simplest +grand unified theory works. + +OK, now, there are important +things that need to be said, + +but we're out of time. + +So I guess what we need +to do is to withhold + +from the next problem set, +the magnetic monopole problem. + +Maybe I was a bit over-ambitious +to put it on the problem set. + +So I'll send an email +announcing that. + +But the one problem +on the problem + +set for next week about +grand unified theories + +will be withheld. + +And Scott Hughes will pick up +this discussion next Tuesday. + +So I will see all of +you-- gee willikers, + +if you come to my office +hour, I'll see you then. + +But otherwise, I may not +see you until the quiz. + +So have a good Thanksgiving +and good luck on the quiz. \ No newline at end of file diff --git a/PKOhhK7kPi4.txt b/PKOhhK7kPi4.txt new file mode 100644 index 0000000000000000000000000000000000000000..33cfff0c2266b6a992654e6f19269201fc87cd50 --- /dev/null +++ b/PKOhhK7kPi4.txt @@ -0,0 +1,419 @@ +align:start position:0% + +we'd like to consider torques on a body + + align:start position:0% +we'd like to consider torques on a body + + + align:start position:0% +we'd like to consider torques on a body +let's draw an arbitrary body and let's + + align:start position:0% +let's draw an arbitrary body and let's + + + align:start position:0% +let's draw an arbitrary body and let's +consider a point s that we're about to + + align:start position:0% +consider a point s that we're about to + + + align:start position:0% +consider a point s that we're about to +calculate the tort now we know that + + align:start position:0% +calculate the tort now we know that + + + align:start position:0% +calculate the tort now we know that +forces on the body can be both internal + + align:start position:0% +forces on the body can be both internal + + + align:start position:0% +forces on the body can be both internal +and external and we'd like to show that + + align:start position:0% +and external and we'd like to show that + + + align:start position:0% +and external and we'd like to show that +all internal torques will cancel in + + align:start position:0% +all internal torques will cancel in + + + align:start position:0% +all internal torques will cancel in +pairs the way we'll do that is suppose + + align:start position:0% +pairs the way we'll do that is suppose + + + align:start position:0% +pairs the way we'll do that is suppose +we pick a object we'll label it with + + align:start position:0% +we pick a object we'll label it with + + + align:start position:0% +we pick a object we'll label it with +mass M I and another object we'll label + + align:start position:0% +mass M I and another object we'll label + + + align:start position:0% +mass M I and another object we'll label +that with mass M J these are small mass + + align:start position:0% +that with mass M J these are small mass + + + align:start position:0% +that with mass M J these are small mass +elements in the body and we'd like to + + align:start position:0% +elements in the body and we'd like to + + + align:start position:0% +elements in the body and we'd like to +know something about the internal forces + + align:start position:0% +know something about the internal forces + + + align:start position:0% +know something about the internal forces +now let's make the assumption and this + + align:start position:0% +now let's make the assumption and this + + + align:start position:0% +now let's make the assumption and this +is the key property that the force due + + align:start position:0% +is the key property that the force due + + + align:start position:0% +is the key property that the force due +to this interaction between J and the + + align:start position:0% +to this interaction between J and the + + + align:start position:0% +to this interaction between J and the +eigth particle pointing that way and + + align:start position:0% +eigth particle pointing that way and + + + align:start position:0% +eigth particle pointing that way and +here's the Newton's third law pair that + + align:start position:0% +here's the Newton's third law pair that + + + align:start position:0% +here's the Newton's third law pair that +these forces lie are directed along the + + align:start position:0% +these forces lie are directed along the + + + align:start position:0% +these forces lie are directed along the +line connecting the two bodies with this + + align:start position:0% +line connecting the two bodies with this + + + align:start position:0% +line connecting the two bodies with this +assumption will now show that the torque + + align:start position:0% +assumption will now show that the torque + + + align:start position:0% +assumption will now show that the torque +on due to these two internal forces you + + align:start position:0% +on due to these two internal forces you + + + align:start position:0% +on due to these two internal forces you +know the third law pairs will cancel so + + align:start position:0% +know the third law pairs will cancel so + + + align:start position:0% +know the third law pairs will cancel so +let's calculate that out so we draw our + + align:start position:0% +let's calculate that out so we draw our + + + align:start position:0% +let's calculate that out so we draw our +vector from our s I and our other vector + + align:start position:0% +vector from our s I and our other vector + + + align:start position:0% +vector from our s I and our other vector +R s J and now in position to add these + + align:start position:0% +R s J and now in position to add these + + + align:start position:0% +R s J and now in position to add these +two torques so we have the torque on s + + align:start position:0% +two torques so we have the torque on s + + + align:start position:0% +two torques so we have the torque on s +due to this pair is equal to the sum of + + align:start position:0% +due to this pair is equal to the sum of + + + align:start position:0% +due to this pair is equal to the sum of +our s I cross f ji plus r s that's an R + + align:start position:0% +our s I cross f ji plus r s that's an R + + + align:start position:0% +our s I cross f ji plus r s that's an R +make sure we get that right we have our + + align:start position:0% +make sure we get that right we have our + + + align:start position:0% +make sure we get that right we have our +s J cross F I J now the third law pair + + align:start position:0% +s J cross F I J now the third law pair + + + align:start position:0% +s J cross F I J now the third law pair +says F ji is equal to minus F I J and so + + align:start position:0% +says F ji is equal to minus F I J and so + + + align:start position:0% +says F ji is equal to minus F I J and so +if we substitute let's put the minus + + align:start position:0% +if we substitute let's put the minus + + + align:start position:0% +if we substitute let's put the minus +sign over here we get our si minus R s J + + align:start position:0% +sign over here we get our si minus R s J + + + align:start position:0% +sign over here we get our si minus R s J +cross F + + align:start position:0% +cross F + + + align:start position:0% +cross F +J I now let's look at this vector in + + align:start position:0% +J I now let's look at this vector in + + + align:start position:0% +J I now let's look at this vector in +particular we can draw it again over + + align:start position:0% +particular we can draw it again over + + + align:start position:0% +particular we can draw it again over +here just to see it + + align:start position:0% +here just to see it + + + align:start position:0% +here just to see it +here's s here is RS I here is the vector + + align:start position:0% +here's s here is RS I here is the vector + + + align:start position:0% +here's s here is RS I here is the vector +R s that's our s J and we want to now + + align:start position:0% +R s that's our s J and we want to now + + + align:start position:0% +R s that's our s J and we want to now +consider the vector R s I minus r SJ + + align:start position:0% +consider the vector R s I minus r SJ + + + align:start position:0% +consider the vector R s I minus r SJ +notice that this vector is directed + + align:start position:0% +notice that this vector is directed + + + align:start position:0% +notice that this vector is directed +along the lines connecting the I in the + + align:start position:0% +along the lines connecting the I in the + + + align:start position:0% +along the lines connecting the I in the +J particle and we've made an assumption + + align:start position:0% +J particle and we've made an assumption + + + align:start position:0% +J particle and we've made an assumption +that F J I is also along that line so + + align:start position:0% +that F J I is also along that line so + + + align:start position:0% +that F J I is also along that line so +these two vectors in this particular + + align:start position:0% +these two vectors in this particular + + + align:start position:0% +these two vectors in this particular +case are either parallel or antiparallel + + align:start position:0% +case are either parallel or antiparallel + + + align:start position:0% +case are either parallel or antiparallel +and hence the torque due to the sum of + + align:start position:0% +and hence the torque due to the sum of + + + align:start position:0% +and hence the torque due to the sum of +these internal forces cancel in pairs + + align:start position:0% +these internal forces cancel in pairs + + + align:start position:0% +these internal forces cancel in pairs +and this means we only need to address + + align:start position:0% +and this means we only need to address + + + align:start position:0% +and this means we only need to address +the torque due to external forces that + + align:start position:0% +the torque due to external forces that + + + align:start position:0% +the torque due to external forces that +are acting on individual elements in a + + align:start position:0% +are acting on individual elements in a + + + align:start position:0% +are acting on individual elements in a +body \ No newline at end of file diff --git a/Q8bGQAAooY8.txt b/Q8bGQAAooY8.txt new file mode 100644 index 0000000000000000000000000000000000000000..3ce5ef68f779d0267ca89e4e8dda2fb76cdb1437 --- /dev/null +++ b/Q8bGQAAooY8.txt @@ -0,0 +1,5115 @@ +align:start position:0% + +many times + + align:start position:0% +many times + + + align:start position:0% +many times +what is happening at the heart of racism + + align:start position:0% +what is happening at the heart of racism + + + align:start position:0% +what is happening at the heart of racism +are people not merely + + align:start position:0% +are people not merely + + + align:start position:0% +are people not merely +denying other people's dignity and + + align:start position:0% +denying other people's dignity and + + + align:start position:0% +denying other people's dignity and +humanity but denying their very own + + align:start position:0% +humanity but denying their very own + + + align:start position:0% +humanity but denying their very own +dignity and humanity + + align:start position:0% + + + + align:start position:0% + +today on chalk radio an innovative + + align:start position:0% +today on chalk radio an innovative + + + align:start position:0% +today on chalk radio an innovative +approach to teaching about race + + align:start position:0% +approach to teaching about race + + + align:start position:0% +approach to teaching about race +and racism it means you know putting + + align:start position:0% +and racism it means you know putting + + + align:start position:0% +and racism it means you know putting +back and asking some tough questions + + align:start position:0% +back and asking some tough questions + + + align:start position:0% +back and asking some tough questions +about our society about ourselves about + + align:start position:0% +about our society about ourselves about + + + align:start position:0% +about our society about ourselves about +what it takes to move forward + + align:start position:0% +what it takes to move forward + + + align:start position:0% +what it takes to move forward +understanding each other but also + + align:start position:0% +understanding each other but also + + + align:start position:0% +understanding each other but also +working + + align:start position:0% +working + + + align:start position:0% +working +to advance a much more just society and + + align:start position:0% +to advance a much more just society and + + + align:start position:0% +to advance a much more just society and +a much better way of understanding + + align:start position:0% +a much better way of understanding + + + align:start position:0% +a much better way of understanding +what it means to coexist in this episode + + align:start position:0% +what it means to coexist in this episode + + + align:start position:0% +what it means to coexist in this episode +an urban studies course examines our + + align:start position:0% +an urban studies course examines our + + + align:start position:0% +an urban studies course examines our +lives in public spaces + + align:start position:0% +lives in public spaces + + + align:start position:0% +lives in public spaces +and invites us to consider how our very + + align:start position:0% +and invites us to consider how our very + + + align:start position:0% +and invites us to consider how our very +personal experiences + + align:start position:0% +personal experiences + + + align:start position:0% +personal experiences +might also contain the experiences of + + align:start position:0% +might also contain the experiences of + + + align:start position:0% +might also contain the experiences of +others + + align:start position:0% + + + + align:start position:0% + +in our conversation about his course 11s + + align:start position:0% +in our conversation about his course 11s + + + align:start position:0% +in our conversation about his course 11s +947 the fire this time race and racism + + align:start position:0% +947 the fire this time race and racism + + + align:start position:0% +947 the fire this time race and racism +in american cities + + align:start position:0% +in american cities + + + align:start position:0% +in american cities +visiting scholar and acclaimed essayist + + align:start position:0% +visiting scholar and acclaimed essayist + + + align:start position:0% +visiting scholar and acclaimed essayist +garnett + + align:start position:0% +garnett + + + align:start position:0% +garnett +carrigan shares his approach for helping + + align:start position:0% +carrigan shares his approach for helping + + + align:start position:0% +carrigan shares his approach for helping +students wrestle with + + align:start position:0% +students wrestle with + + + align:start position:0% +students wrestle with +as he puts it the story of racism in the + + align:start position:0% +as he puts it the story of racism in the + + + align:start position:0% +as he puts it the story of racism in the +united states + + align:start position:0% +united states + + + align:start position:0% +united states +part of what i love about garnett's + + align:start position:0% +part of what i love about garnett's + + + align:start position:0% +part of what i love about garnett's +approach is how he weaves his own life + + align:start position:0% +approach is how he weaves his own life + + + align:start position:0% +approach is how he weaves his own life +experiences into his teaching + + align:start position:0% +experiences into his teaching + + + align:start position:0% +experiences into his teaching +a large focus of his life and work has + + align:start position:0% +a large focus of his life and work has + + + align:start position:0% +a large focus of his life and work has +been observing cities + + align:start position:0% +been observing cities + + + align:start position:0% +been observing cities +through a unique modality walking + + align:start position:0% +through a unique modality walking + + + align:start position:0% +through a unique modality walking +it's such a human pace + + align:start position:0% + + + + align:start position:0% + +it allows us to inscribe + + align:start position:0% +it allows us to inscribe + + + align:start position:0% +it allows us to inscribe +ourselves onto the world and allow the + + align:start position:0% +ourselves onto the world and allow the + + + align:start position:0% +ourselves onto the world and allow the +world to inscribe itself + + align:start position:0% +world to inscribe itself + + + align:start position:0% +world to inscribe itself +onto our imagination but more than + + align:start position:0% +onto our imagination but more than + + + align:start position:0% +onto our imagination but more than +anything else + + align:start position:0% +anything else + + + align:start position:0% +anything else +it's a marvelously joyful way of getting + + align:start position:0% +it's a marvelously joyful way of getting + + + align:start position:0% +it's a marvelously joyful way of getting +to know the world + + align:start position:0% +to know the world + + + align:start position:0% +to know the world +of getting snowed up close not merely + + align:start position:0% +of getting snowed up close not merely + + + align:start position:0% +of getting snowed up close not merely +getting to know it but + + align:start position:0% +getting to know it but + + + align:start position:0% +getting to know it but +getting to know ourselves through the + + align:start position:0% +getting to know ourselves through the + + + align:start position:0% +getting to know ourselves through the +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +surprising encounters we might have + + align:start position:0% +surprising encounters we might have + + + align:start position:0% +surprising encounters we might have +so one of the things i love most about + + align:start position:0% +so one of the things i love most about + + + align:start position:0% +so one of the things i love most about +walking is the way in which it opens us + + align:start position:0% +walking is the way in which it opens us + + + align:start position:0% +walking is the way in which it opens us +up to serendipity + + align:start position:0% +up to serendipity + + + align:start position:0% +up to serendipity +so walking as a way of knowing the world + + align:start position:0% +so walking as a way of knowing the world + + + align:start position:0% +so walking as a way of knowing the world +as a way of knowing ourselves as a way + + align:start position:0% +as a way of knowing ourselves as a way + + + align:start position:0% +as a way of knowing ourselves as a way +of + + align:start position:0% +of + + + align:start position:0% +of +being open to the surprise and + + align:start position:0% +being open to the surprise and + + + align:start position:0% +being open to the surprise and +serendipitous of the world + + align:start position:0% + + + + align:start position:0% + +garnett grew up in jamaica where he + + align:start position:0% +garnett grew up in jamaica where he + + + align:start position:0% +garnett grew up in jamaica where he +learned to navigate public spaces + + align:start position:0% +learned to navigate public spaces + + + align:start position:0% +learned to navigate public spaces +on foot in jamaica as i walked i walked + + align:start position:0% +on foot in jamaica as i walked i walked + + + align:start position:0% +on foot in jamaica as i walked i walked +a lot at night + + align:start position:0% +a lot at night + + + align:start position:0% +a lot at night +after public transportation had stopped + + align:start position:0% +after public transportation had stopped + + + align:start position:0% +after public transportation had stopped +running + + align:start position:0% +running + + + align:start position:0% +running +and would navigate from friends homes + + align:start position:0% +and would navigate from friends homes + + + align:start position:0% +and would navigate from friends homes +to my home and pass through some + + align:start position:0% +to my home and pass through some + + + align:start position:0% +to my home and pass through some +very dangerous neighborhoods and learned + + align:start position:0% +very dangerous neighborhoods and learned + + + align:start position:0% +very dangerous neighborhoods and learned +how to + + align:start position:0% +how to + + + align:start position:0% +how to +be streetwise as in + + align:start position:0% +be streetwise as in + + + align:start position:0% +be streetwise as in +you know the wisdom gained from constant + + align:start position:0% +you know the wisdom gained from constant + + + align:start position:0% +you know the wisdom gained from constant +observation + + align:start position:0% +observation + + + align:start position:0% +observation +and being able to anticipate dangers + + align:start position:0% +and being able to anticipate dangers + + + align:start position:0% +and being able to anticipate dangers +or sometimes encountering true dangers + + align:start position:0% +or sometimes encountering true dangers + + + align:start position:0% +or sometimes encountering true dangers +and knowing how to get away from the + + align:start position:0% +and knowing how to get away from the + + + align:start position:0% +and knowing how to get away from the +dangers and i thought that's all you + + align:start position:0% +dangers and i thought that's all you + + + align:start position:0% +dangers and i thought that's all you +needed to do + + align:start position:0% +needed to do + + + align:start position:0% +needed to do +to be in a navigating in public space + + align:start position:0% +to be in a navigating in public space + + + align:start position:0% +to be in a navigating in public space +and to be safe + + align:start position:0% +and to be safe + + + align:start position:0% +and to be safe +to anticipate the dangers and veer away + + align:start position:0% +to anticipate the dangers and veer away + + + align:start position:0% +to anticipate the dangers and veer away +from them + + align:start position:0% + + + + align:start position:0% + +when he arrived in the united states as + + align:start position:0% +when he arrived in the united states as + + + align:start position:0% +when he arrived in the united states as +a college student + + align:start position:0% +a college student + + + align:start position:0% +a college student +his experiences with racism began to + + align:start position:0% +his experiences with racism began to + + + align:start position:0% +his experiences with racism began to +shape the way he traversed + + align:start position:0% +shape the way he traversed + + + align:start position:0% +shape the way he traversed +city streets and i came to the us with + + align:start position:0% +city streets and i came to the us with + + + align:start position:0% +city streets and i came to the us with +that sensibility + + align:start position:0% +that sensibility + + + align:start position:0% +that sensibility +and then began encountering racism + + align:start position:0% +and then began encountering racism + + + align:start position:0% +and then began encountering racism +but recognized that what actually + + align:start position:0% +but recognized that what actually + + + align:start position:0% +but recognized that what actually +happened then it wasn't so much + + align:start position:0% +happened then it wasn't so much + + + align:start position:0% +happened then it wasn't so much +learning how to read a danger but learn + + align:start position:0% +learning how to read a danger but learn + + + align:start position:0% +learning how to read a danger but learn +to read + + align:start position:0% +to read + + + align:start position:0% +to read +in places in which people thought i was + + align:start position:0% +in places in which people thought i was + + + align:start position:0% +in places in which people thought i was +a danger that's what that happened that + + align:start position:0% +a danger that's what that happened that + + + align:start position:0% +a danger that's what that happened that +and it was over and over again me seeing + + align:start position:0% +and it was over and over again me seeing + + + align:start position:0% +and it was over and over again me seeing +the dangers and varying away from it + + align:start position:0% +the dangers and varying away from it + + + align:start position:0% +the dangers and varying away from it +but then suddenly recognizing and being + + align:start position:0% +but then suddenly recognizing and being + + + align:start position:0% +but then suddenly recognizing and being +shocked to know that + + align:start position:0% +shocked to know that + + + align:start position:0% +shocked to know that +i was a danger and i was a danger + + align:start position:0% +i was a danger and i was a danger + + + align:start position:0% +i was a danger and i was a danger +because i was black because of my skin + + align:start position:0% +because i was black because of my skin + + + align:start position:0% +because i was black because of my skin +color + + align:start position:0% +color + + + align:start position:0% +color +so navigating then suddenly became + + align:start position:0% +so navigating then suddenly became + + + align:start position:0% +so navigating then suddenly became +trying to anticipate + + align:start position:0% +trying to anticipate + + + align:start position:0% +trying to anticipate +the ways in which people would + + align:start position:0% +the ways in which people would + + + align:start position:0% +the ways in which people would +anticipate me being dangerous + + align:start position:0% +anticipate me being dangerous + + + align:start position:0% +anticipate me being dangerous +it meant calibrating my movements not to + + align:start position:0% +it meant calibrating my movements not to + + + align:start position:0% +it meant calibrating my movements not to +fare + + align:start position:0% +fare + + + align:start position:0% +fare +but calibrating my movements the + + align:start position:0% +but calibrating my movements the + + + align:start position:0% +but calibrating my movements the +people's fear of me + + align:start position:0% +people's fear of me + + + align:start position:0% +people's fear of me +and knowing that that could be dangerous + + align:start position:0% +and knowing that that could be dangerous + + + align:start position:0% +and knowing that that could be dangerous +for me that it could mean anything from + + align:start position:0% +for me that it could mean anything from + + + align:start position:0% +for me that it could mean anything from +them attacking me which had happened or + + align:start position:0% +them attacking me which had happened or + + + align:start position:0% +them attacking me which had happened or +threatening to attack me + + align:start position:0% +threatening to attack me + + + align:start position:0% +threatening to attack me +you know or them calling the police who + + align:start position:0% +you know or them calling the police who + + + align:start position:0% +you know or them calling the police who +would then give me a tough time + + align:start position:0% + + + + align:start position:0% + +i'm able to many times deal with the + + align:start position:0% +i'm able to many times deal with the + + + align:start position:0% +i'm able to many times deal with the +awfulness + + align:start position:0% +awfulness + + + align:start position:0% +awfulness +that the world throws at me because of + + align:start position:0% +that the world throws at me because of + + + align:start position:0% +that the world throws at me because of +the beauty that the world also presents + + align:start position:0% +the beauty that the world also presents + + + align:start position:0% +the beauty that the world also presents +that the world is never just + + align:start position:0% +that the world is never just + + + align:start position:0% +that the world is never just +one thing and so yes their people will + + align:start position:0% +one thing and so yes their people will + + + align:start position:0% +one thing and so yes their people will +shout in + + align:start position:0% +shout in + + + align:start position:0% +shout in +awful racist things around the street + + align:start position:0% +awful racist things around the street + + + align:start position:0% +awful racist things around the street +but there's also that stranger who says + + align:start position:0% +but there's also that stranger who says + + + align:start position:0% +but there's also that stranger who says +oh i'm going to a barbecue and it looks + + align:start position:0% +oh i'm going to a barbecue and it looks + + + align:start position:0% +oh i'm going to a barbecue and it looks +like you're just + + align:start position:0% +like you're just + + + align:start position:0% +like you're just +wandering and looking for something to + + align:start position:0% +wandering and looking for something to + + + align:start position:0% +wandering and looking for something to +do you want to come along with us + + align:start position:0% +do you want to come along with us + + + align:start position:0% +do you want to come along with us +and so that's that's the very same world + + align:start position:0% +and so that's that's the very same world + + + align:start position:0% +and so that's that's the very same world +the very same world there was something + + align:start position:0% +the very same world there was something + + + align:start position:0% +the very same world there was something +so + + align:start position:0% +so + + + align:start position:0% +so +powerful in that idea and i began to + + align:start position:0% +powerful in that idea and i began to + + + align:start position:0% +powerful in that idea and i began to +wonder + + align:start position:0% +wonder + + + align:start position:0% +wonder +how this outlook shaped garnett's + + align:start position:0% +how this outlook shaped garnett's + + + align:start position:0% +how this outlook shaped garnett's +teaching in the classroom + + align:start position:0% +teaching in the classroom + + + align:start position:0% +teaching in the classroom +how we approach the ideas of race and + + align:start position:0% +how we approach the ideas of race and + + + align:start position:0% +how we approach the ideas of race and +racism with students with this outlook + + align:start position:0% +racism with students with this outlook + + + align:start position:0% +racism with students with this outlook +in mind + + align:start position:0% +in mind + + + align:start position:0% +in mind +i focus very much in the classroom in on + + align:start position:0% +i focus very much in the classroom in on + + + align:start position:0% +i focus very much in the classroom in on +joy + + align:start position:0% +joy + + + align:start position:0% +joy +in a way in which joy joy becomes in so + + align:start position:0% +in a way in which joy joy becomes in so + + + align:start position:0% +in a way in which joy joy becomes in so +many ways + + align:start position:0% +many ways + + + align:start position:0% +many ways +both a hope and the way it joys where to + + align:start position:0% +both a hope and the way it joys where to + + + align:start position:0% +both a hope and the way it joys where to +hope but wait joy's + + align:start position:0% +hope but wait joy's + + + align:start position:0% +hope but wait joy's +also read you know where to resistance + + align:start position:0% +also read you know where to resistance + + + align:start position:0% +also read you know where to resistance +you know the way + + align:start position:0% +you know the way + + + align:start position:0% +you know the way +joy is wed to our ability to + + align:start position:0% +joy is wed to our ability to + + + align:start position:0% +joy is wed to our ability to +deal with these things and to push past + + align:start position:0% +deal with these things and to push past + + + align:start position:0% +deal with these things and to push past +these things so + + align:start position:0% +these things so + + + align:start position:0% +these things so +as a teacher i time and again + + align:start position:0% +as a teacher i time and again + + + align:start position:0% +as a teacher i time and again +try to invite students to read the way i + + align:start position:0% +try to invite students to read the way i + + + align:start position:0% +try to invite students to read the way i +walk + + align:start position:0% +walk + + + align:start position:0% +walk +it becomes a way of having a + + align:start position:0% +it becomes a way of having a + + + align:start position:0% +it becomes a way of having a +conversation in a conversation with the + + align:start position:0% +conversation in a conversation with the + + + align:start position:0% +conversation in a conversation with the +past + + align:start position:0% +past + + + align:start position:0% +past +conversation of the present a + + align:start position:0% +conversation of the present a + + + align:start position:0% +conversation of the present a +conversation with people nearby a + + align:start position:0% +conversation with people nearby a + + + align:start position:0% +conversation with people nearby a +conversation with people who are far + + align:start position:0% +conversation with people who are far + + + align:start position:0% +conversation with people who are far +away + + align:start position:0% +away + + + align:start position:0% +away +and more than anything is a conversation + + align:start position:0% +and more than anything is a conversation + + + align:start position:0% +and more than anything is a conversation +with yourself + + align:start position:0% +with yourself + + + align:start position:0% +with yourself +a way of resting with yourself that in + + align:start position:0% +a way of resting with yourself that in + + + align:start position:0% +a way of resting with yourself that in +the end or that's my hope + + align:start position:0% +the end or that's my hope + + + align:start position:0% +the end or that's my hope +in in a different self and it can emerge + + align:start position:0% +in in a different self and it can emerge + + + align:start position:0% +in in a different self and it can emerge +a different better self much more of the + + align:start position:0% +a different better self much more of the + + + align:start position:0% +a different better self much more of the +discovery and encounter + + align:start position:0% +discovery and encounter + + + align:start position:0% +discovery and encounter +for garnett encountering others is key + + align:start position:0% +for garnett encountering others is key + + + align:start position:0% +for garnett encountering others is key +to understanding the story of racism in + + align:start position:0% +to understanding the story of racism in + + + align:start position:0% +to understanding the story of racism in +american cities + + align:start position:0% +american cities + + + align:start position:0% +american cities +and for imagining a different much more + + align:start position:0% +and for imagining a different much more + + + align:start position:0% +and for imagining a different much more +dignified way to co-exist + + align:start position:0% +dignified way to co-exist + + + align:start position:0% +dignified way to co-exist +it's an idea that grounds how he teaches + + align:start position:0% +it's an idea that grounds how he teaches + + + align:start position:0% +it's an idea that grounds how he teaches +about these complexities + + align:start position:0% +about these complexities + + + align:start position:0% +about these complexities +what does it mean to think of the + + align:start position:0% +what does it mean to think of the + + + align:start position:0% +what does it mean to think of the +classroom as a + + align:start position:0% +classroom as a + + + align:start position:0% +classroom as a +place of encounter in which you're + + align:start position:0% +place of encounter in which you're + + + align:start position:0% +place of encounter in which you're +continually + + align:start position:0% +continually + + + align:start position:0% +continually +encountering these issues these + + align:start position:0% +encountering these issues these + + + align:start position:0% +encountering these issues these +histories + + align:start position:0% +histories + + + align:start position:0% +histories +these landscapes these complexities + + align:start position:0% +these landscapes these complexities + + + align:start position:0% +these landscapes these complexities +these people + + align:start position:0% +these people + + + align:start position:0% +these people +and what does it mean to truly listen to + + align:start position:0% +and what does it mean to truly listen to + + + align:start position:0% +and what does it mean to truly listen to +truly understand + + align:start position:0% +truly understand + + + align:start position:0% +truly understand +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +garnet shared with me that it can feel + + align:start position:0% +garnet shared with me that it can feel + + + align:start position:0% +garnet shared with me that it can feel +disheartening to unpack the complexities + + align:start position:0% +disheartening to unpack the complexities + + + align:start position:0% +disheartening to unpack the complexities +of racism in our society + + align:start position:0% +of racism in our society + + + align:start position:0% +of racism in our society +students and teachers alike may + + align:start position:0% +students and teachers alike may + + + align:start position:0% +students and teachers alike may +experience burnout over the course of a + + align:start position:0% +experience burnout over the course of a + + + align:start position:0% +experience burnout over the course of a +semester + + align:start position:0% +semester + + + align:start position:0% +semester +as i talked with garnett it struck me + + align:start position:0% +as i talked with garnett it struck me + + + align:start position:0% +as i talked with garnett it struck me +that helping students cultivate + + align:start position:0% +that helping students cultivate + + + align:start position:0% +that helping students cultivate +curiosity about themselves + + align:start position:0% +curiosity about themselves + + + align:start position:0% +curiosity about themselves +and others was a strategic way to + + align:start position:0% +and others was a strategic way to + + + align:start position:0% +and others was a strategic way to +sustain their engagement + + align:start position:0% +sustain their engagement + + + align:start position:0% +sustain their engagement +when you have something so huge it's to + + align:start position:0% +when you have something so huge it's to + + + align:start position:0% +when you have something so huge it's to +say oh we're just going to climb this + + align:start position:0% +say oh we're just going to climb this + + + align:start position:0% +say oh we're just going to climb this +mountain right away + + align:start position:0% +mountain right away + + + align:start position:0% +mountain right away +it's it's just impossible that your legs + + align:start position:0% +it's it's just impossible that your legs + + + align:start position:0% +it's it's just impossible that your legs +will give out you know quite quickly and + + align:start position:0% +will give out you know quite quickly and + + + align:start position:0% +will give out you know quite quickly and +it will just + + align:start position:0% +it will just + + + align:start position:0% +it will just +lead to frustration so i invite them to + + align:start position:0% +lead to frustration so i invite them to + + + align:start position:0% +lead to frustration so i invite them to +just take a small + + align:start position:0% +just take a small + + + align:start position:0% +just take a small +patch and to you know keep moving patch + + align:start position:0% +patch and to you know keep moving patch + + + align:start position:0% +patch and to you know keep moving patch +by patch + + align:start position:0% +by patch + + + align:start position:0% +by patch +in on that mountain until at a certain + + align:start position:0% +in on that mountain until at a certain + + + align:start position:0% +in on that mountain until at a certain +point they look up and they go oh + + align:start position:0% +point they look up and they go oh + + + align:start position:0% +point they look up and they go oh +we're halfway up and we're actually not + + align:start position:0% +we're halfway up and we're actually not + + + align:start position:0% +we're halfway up and we're actually not +even trying to + + align:start position:0% +even trying to + + + align:start position:0% +even trying to +conquer the mountain anymore this was + + align:start position:0% +conquer the mountain anymore this was + + + align:start position:0% +conquer the mountain anymore this was +the wrong way to to go about it you know + + align:start position:0% +the wrong way to to go about it you know + + + align:start position:0% +the wrong way to to go about it you know +we're just + + align:start position:0% +we're just + + + align:start position:0% +we're just +now at the place in which we're happy to + + align:start position:0% +now at the place in which we're happy to + + + align:start position:0% +now at the place in which we're happy to +investigate the terrain and then the axe + + align:start position:0% +investigate the terrain and then the axe + + + align:start position:0% +investigate the terrain and then the axe +each other + + align:start position:0% +each other + + + align:start position:0% +each other +what the turret looks like where you are + + align:start position:0% +what the turret looks like where you are + + + align:start position:0% +what the turret looks like where you are +so i could learn more about the mountain + + align:start position:0% +so i could learn more about the mountain + + + align:start position:0% +so i could learn more about the mountain +and + + align:start position:0% +and + + + align:start position:0% +and +we might actually even reach the top but + + align:start position:0% +we might actually even reach the top but + + + align:start position:0% +we might actually even reach the top but +we'd have a much better understanding + + align:start position:0% +we'd have a much better understanding + + + align:start position:0% +we'd have a much better understanding +of landscape and of flora and fauna + + align:start position:0% +of landscape and of flora and fauna + + + align:start position:0% +of landscape and of flora and fauna +and of nature and + + align:start position:0% +and of nature and + + + align:start position:0% +and of nature and +much better sense of what it means to + + align:start position:0% +much better sense of what it means to + + + align:start position:0% +much better sense of what it means to +hike thoughtfully + + align:start position:0% + + + + align:start position:0% + +as an essayist garnett brings an + + align:start position:0% +as an essayist garnett brings an + + + align:start position:0% +as an essayist garnett brings an +innovative slant to teaching about race + + align:start position:0% +innovative slant to teaching about race + + + align:start position:0% +innovative slant to teaching about race +and racism + + align:start position:0% +and racism + + + align:start position:0% +and racism +for him the act of writing and having + + align:start position:0% +for him the act of writing and having + + + align:start position:0% +for him the act of writing and having +students write + + align:start position:0% +students write + + + align:start position:0% +students write +is a way to do the work of encountering + + align:start position:0% +is a way to do the work of encountering + + + align:start position:0% +is a way to do the work of encountering +others + + align:start position:0% +others + + + align:start position:0% +others +writing is sometimes just merely a way + + align:start position:0% +writing is sometimes just merely a way + + + align:start position:0% +writing is sometimes just merely a way +of raising questions rather than giving + + align:start position:0% +of raising questions rather than giving + + + align:start position:0% +of raising questions rather than giving +answers + + align:start position:0% +answers + + + align:start position:0% +answers +particularly issues connected with race + + align:start position:0% +particularly issues connected with race + + + align:start position:0% +particularly issues connected with race +and racism and cities + + align:start position:0% +and racism and cities + + + align:start position:0% +and racism and cities +that's a big order it's + + align:start position:0% +that's a big order it's + + + align:start position:0% +that's a big order it's +a lifetime of thinking and wrestling + + align:start position:0% +a lifetime of thinking and wrestling + + + align:start position:0% +a lifetime of thinking and wrestling +with complicated + + align:start position:0% +with complicated + + + align:start position:0% +with complicated +issues racism race which is produced by + + align:start position:0% +issues racism race which is produced by + + + align:start position:0% +issues racism race which is produced by +racism + + align:start position:0% +racism + + + align:start position:0% +racism +in american cities what does it take to + + align:start position:0% +in american cities what does it take to + + + align:start position:0% +in american cities what does it take to +understand and to wrestle + + align:start position:0% +understand and to wrestle + + + align:start position:0% +understand and to wrestle +you know with the in a full inner scope + + align:start position:0% +you know with the in a full inner scope + + + align:start position:0% +you know with the in a full inner scope +and the complications connected with + + align:start position:0% +and the complications connected with + + + align:start position:0% +and the complications connected with +each of these + + align:start position:0% +each of these + + + align:start position:0% +each of these +and the writing becomes a way sometimes + + align:start position:0% +and the writing becomes a way sometimes + + + align:start position:0% +and the writing becomes a way sometimes +just mirror to ask questions to say oh + + align:start position:0% +just mirror to ask questions to say oh + + + align:start position:0% +just mirror to ask questions to say oh +we have not been asking the right + + align:start position:0% +we have not been asking the right + + + align:start position:0% +we have not been asking the right +questions this invites us to ask + + align:start position:0% +questions this invites us to ask + + + align:start position:0% +questions this invites us to ask +new questions or this invites us to see + + align:start position:0% +new questions or this invites us to see + + + align:start position:0% +new questions or this invites us to see +in + + align:start position:0% +in + + + align:start position:0% +in +new ways this invites us to listen and + + align:start position:0% +new ways this invites us to listen and + + + align:start position:0% +new ways this invites us to listen and +more than end things it invites us to + + align:start position:0% +more than end things it invites us to + + + align:start position:0% +more than end things it invites us to +encounter to encounter each other in + + align:start position:0% +encounter to encounter each other in + + + align:start position:0% +encounter to encounter each other in +conversation + + align:start position:0% +conversation + + + align:start position:0% +conversation +but also encounter others on the page it + + align:start position:0% +but also encounter others on the page it + + + align:start position:0% +but also encounter others on the page it +means you know pulling back and asking + + align:start position:0% +means you know pulling back and asking + + + align:start position:0% +means you know pulling back and asking +some tough questions about our society + + align:start position:0% +some tough questions about our society + + + align:start position:0% +some tough questions about our society +about ourselves about + + align:start position:0% +about ourselves about + + + align:start position:0% +about ourselves about +what it takes to move forward + + align:start position:0% +what it takes to move forward + + + align:start position:0% +what it takes to move forward +understanding each other but also + + align:start position:0% +understanding each other but also + + + align:start position:0% +understanding each other but also +working to advance a much more just + + align:start position:0% +working to advance a much more just + + + align:start position:0% +working to advance a much more just +society + + align:start position:0% +society + + + align:start position:0% +society +and a much better way of + + align:start position:0% +and a much better way of + + + align:start position:0% +and a much better way of +understanding what it means to coexist + + align:start position:0% +understanding what it means to coexist + + + align:start position:0% +understanding what it means to coexist +what it means + + align:start position:0% +what it means + + + align:start position:0% +what it means +to live together alongside each other + + align:start position:0% +to live together alongside each other + + + align:start position:0% +to live together alongside each other +and the writing becomes a way to explore + + align:start position:0% +and the writing becomes a way to explore + + + align:start position:0% +and the writing becomes a way to explore +that + + align:start position:0% +that + + + align:start position:0% +that +so as they're writing they're suddenly + + align:start position:0% +so as they're writing they're suddenly + + + align:start position:0% +so as they're writing they're suddenly +recognizing that the whole world + + align:start position:0% +recognizing that the whole world + + + align:start position:0% +recognizing that the whole world +is their material and they're invited to + + align:start position:0% +is their material and they're invited to + + + align:start position:0% +is their material and they're invited to +think + + align:start position:0% +think + + + align:start position:0% +think +just expansively and to start + + align:start position:0% +just expansively and to start + + + align:start position:0% +just expansively and to start +recognizing ways in which they haven't + + align:start position:0% +recognizing ways in which they haven't + + + align:start position:0% +recognizing ways in which they haven't +been + + align:start position:0% +been + + + align:start position:0% +been +seen the ways in which they haven't been + + align:start position:0% +seen the ways in which they haven't been + + + align:start position:0% +seen the ways in which they haven't been +looking they're beginning to ask what + + align:start position:0% +looking they're beginning to ask what + + + align:start position:0% +looking they're beginning to ask what +might it mean to + + align:start position:0% +might it mean to + + + align:start position:0% +might it mean to +listen to the people who are doing harm + + align:start position:0% +listen to the people who are doing harm + + + align:start position:0% +listen to the people who are doing harm +listen to the people who have + + align:start position:0% +listen to the people who have + + + align:start position:0% +listen to the people who have +experienced harm and to listen you know + + align:start position:0% +experienced harm and to listen you know + + + align:start position:0% +experienced harm and to listen you know +more fully and broadly + + align:start position:0% +more fully and broadly + + + align:start position:0% +more fully and broadly +as my conversation with garnett + + align:start position:0% +as my conversation with garnett + + + align:start position:0% +as my conversation with garnett +continued it became clear + + align:start position:0% +continued it became clear + + + align:start position:0% +continued it became clear +that for him listening more fully + + align:start position:0% +that for him listening more fully + + + align:start position:0% +that for him listening more fully +means tuning into how people navigate + + align:start position:0% +means tuning into how people navigate + + + align:start position:0% +means tuning into how people navigate +the world in nuanced ways + + align:start position:0% +the world in nuanced ways + + + align:start position:0% +the world in nuanced ways +it means writing about how they + + align:start position:0% +it means writing about how they + + + align:start position:0% +it means writing about how they +encounter harm but also + + align:start position:0% +encounter harm but also + + + align:start position:0% +encounter harm but also +how they cultivate joy and hope and + + align:start position:0% +how they cultivate joy and hope and + + + align:start position:0% +how they cultivate joy and hope and +community + + align:start position:0% +community + + + align:start position:0% +community +there is a temptation to write about + + align:start position:0% +there is a temptation to write about + + + align:start position:0% +there is a temptation to write about +people who have experienced racism + + align:start position:0% +people who have experienced racism + + + align:start position:0% +people who have experienced racism +as just a sum total of what has happened + + align:start position:0% +as just a sum total of what has happened + + + align:start position:0% +as just a sum total of what has happened +to them so they're + + align:start position:0% +to them so they're + + + align:start position:0% +to them so they're +you know merely victims with no agency + + align:start position:0% +you know merely victims with no agency + + + align:start position:0% +you know merely victims with no agency +and they're then invited to go beyond + + align:start position:0% +and they're then invited to go beyond + + + align:start position:0% +and they're then invited to go beyond +that + + align:start position:0% +that + + + align:start position:0% +that +by suddenly asking what are the ways in + + align:start position:0% +by suddenly asking what are the ways in + + + align:start position:0% +by suddenly asking what are the ways in +which they experience + + align:start position:0% +which they experience + + + align:start position:0% +which they experience +joy what are the ways in which they hope + + align:start position:0% +joy what are the ways in which they hope + + + align:start position:0% +joy what are the ways in which they hope +what are the ways in which they + + align:start position:0% +what are the ways in which they + + + align:start position:0% +what are the ways in which they +work towards creating a sense of + + align:start position:0% +work towards creating a sense of + + + align:start position:0% +work towards creating a sense of +belonging for themselves and others + + align:start position:0% +belonging for themselves and others + + + align:start position:0% +belonging for themselves and others +what are the tight bonds of community + + align:start position:0% +what are the tight bonds of community + + + align:start position:0% +what are the tight bonds of community +and + + align:start position:0% +and + + + align:start position:0% +and +family and country + + align:start position:0% +family and country + + + align:start position:0% +family and country +for the people that we're writing about + + align:start position:0% +for the people that we're writing about + + + align:start position:0% +for the people that we're writing about +and what are the ways in which these are + + align:start position:0% +and what are the ways in which these are + + + align:start position:0% +and what are the ways in which these are +broken or erupted or eroded + + align:start position:0% +broken or erupted or eroded + + + align:start position:0% +broken or erupted or eroded +and you're not suddenly speaking of + + align:start position:0% +and you're not suddenly speaking of + + + align:start position:0% +and you're not suddenly speaking of +people + + align:start position:0% +people + + + align:start position:0% +people +in a condescending or paternalistic + + align:start position:0% +in a condescending or paternalistic + + + align:start position:0% +in a condescending or paternalistic +matter you're speaking of people + + align:start position:0% +matter you're speaking of people + + + align:start position:0% +matter you're speaking of people +as fully rounded you know not no longer + + align:start position:0% +as fully rounded you know not no longer + + + align:start position:0% +as fully rounded you know not no longer +flattened + + align:start position:0% +flattened + + + align:start position:0% +flattened +but you're seeing them in in rich + + align:start position:0% +but you're seeing them in in rich + + + align:start position:0% +but you're seeing them in in rich +dimension + + align:start position:0% +dimension + + + align:start position:0% +dimension +with aspirations and + + align:start position:0% +with aspirations and + + + align:start position:0% +with aspirations and +joys and frustrations and faults + + align:start position:0% +joys and frustrations and faults + + + align:start position:0% +joys and frustrations and faults +and virtues even when writing about + + align:start position:0% +and virtues even when writing about + + + align:start position:0% +and virtues even when writing about +people as fully rounded individuals + + align:start position:0% +people as fully rounded individuals + + + align:start position:0% +people as fully rounded individuals +students may encounter challenges when + + align:start position:0% +students may encounter challenges when + + + align:start position:0% +students may encounter challenges when +learning to write about race + + align:start position:0% +learning to write about race + + + align:start position:0% +learning to write about race +garnett elaborated on one of the + + align:start position:0% +garnett elaborated on one of the + + + align:start position:0% +garnett elaborated on one of the +complexities many writers face + + align:start position:0% +complexities many writers face + + + align:start position:0% +complexities many writers face +one of the problems with speaking about + + align:start position:0% +one of the problems with speaking about + + + align:start position:0% +one of the problems with speaking about +and writing about race is that + + align:start position:0% +and writing about race is that + + + align:start position:0% +and writing about race is that +too often people are + + align:start position:0% +too often people are + + + align:start position:0% +too often people are +made to feel that their responsibilities + + align:start position:0% +made to feel that their responsibilities + + + align:start position:0% +made to feel that their responsibilities +are to + + align:start position:0% +are to + + + align:start position:0% +are to +explain one side to another side + + align:start position:0% +explain one side to another side + + + align:start position:0% +explain one side to another side +to explain their black experience + + align:start position:0% +to explain their black experience + + + align:start position:0% +to explain their black experience +to people who are not black + + align:start position:0% +to people who are not black + + + align:start position:0% +to people who are not black +or to explain what it means to + + align:start position:0% +or to explain what it means to + + + align:start position:0% +or to explain what it means to +inhabit a particular body set up + + align:start position:0% +inhabit a particular body set up + + + align:start position:0% +inhabit a particular body set up +experiences + + align:start position:0% +experiences + + + align:start position:0% +experiences +that are unique to you and + + align:start position:0% +that are unique to you and + + + align:start position:0% +that are unique to you and +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +that make moving through or living in + + align:start position:0% +that make moving through or living in + + + align:start position:0% +that make moving through or living in +the world + + align:start position:0% +the world + + + align:start position:0% +the world +uh much worse experience than someone + + align:start position:0% +uh much worse experience than someone + + + align:start position:0% +uh much worse experience than someone +with a + + align:start position:0% +with a + + + align:start position:0% +with a +different skin color but part of + + align:start position:0% +different skin color but part of + + + align:start position:0% +different skin color but part of +the challenge is to show the ways in + + align:start position:0% +the challenge is to show the ways in + + + align:start position:0% +the challenge is to show the ways in +which + + align:start position:0% +which + + + align:start position:0% +which +racism degrades everyone that in + + align:start position:0% +racism degrades everyone that in + + + align:start position:0% +racism degrades everyone that in +degrading someone else + + align:start position:0% +degrading someone else + + + align:start position:0% +degrading someone else +you can't help but degrade yourself + + align:start position:0% +you can't help but degrade yourself + + + align:start position:0% +you can't help but degrade yourself +and in that class one of the things i'm + + align:start position:0% +and in that class one of the things i'm + + + align:start position:0% +and in that class one of the things i'm +trying to + + align:start position:0% +trying to + + + align:start position:0% +trying to +invite people to do trying to invite + + align:start position:0% +invite people to do trying to invite + + + align:start position:0% +invite people to do trying to invite +students to think about + + align:start position:0% +students to think about + + + align:start position:0% +students to think about +is the responsibilities not merely to + + align:start position:0% +is the responsibilities not merely to + + + align:start position:0% +is the responsibilities not merely to +think + + align:start position:0% +think + + + align:start position:0% +think +of writing about race or understanding + + align:start position:0% +of writing about race or understanding + + + align:start position:0% +of writing about race or understanding +race + + align:start position:0% +race + + + align:start position:0% +race +of trying to show you know one set of + + align:start position:0% +of trying to show you know one set of + + + align:start position:0% +of trying to show you know one set of +experiences to + + align:start position:0% +experiences to + + + align:start position:0% +experiences to +someone who's foreign to it but to show + + align:start position:0% +someone who's foreign to it but to show + + + align:start position:0% +someone who's foreign to it but to show +the ways in which + + align:start position:0% +the ways in which + + + align:start position:0% +the ways in which +we have quite a bit of common + + align:start position:0% +we have quite a bit of common + + + align:start position:0% +we have quite a bit of common +experiences + + align:start position:0% +experiences + + + align:start position:0% +experiences +and that many times what is happening + + align:start position:0% +and that many times what is happening + + + align:start position:0% +and that many times what is happening +at the heart of racism are people not + + align:start position:0% +at the heart of racism are people not + + + align:start position:0% +at the heart of racism are people not +merely denying other people's dignity + + align:start position:0% +merely denying other people's dignity + + + align:start position:0% +merely denying other people's dignity +and humanity + + align:start position:0% +and humanity + + + align:start position:0% +and humanity +but deny their very own dignity and + + align:start position:0% +but deny their very own dignity and + + + align:start position:0% +but deny their very own dignity and +humanity and so + + align:start position:0% +humanity and so + + + align:start position:0% +humanity and so +it's an invitation to figure out you + + align:start position:0% +it's an invitation to figure out you + + + align:start position:0% +it's an invitation to figure out you +know how to write about + + align:start position:0% +know how to write about + + + align:start position:0% +know how to write about +race and racism in which we're showing + + align:start position:0% +race and racism in which we're showing + + + align:start position:0% +race and racism in which we're showing +the ways in which we contain + + align:start position:0% +the ways in which we contain + + + align:start position:0% +the ways in which we contain +each other so i keep giving them in a + + align:start position:0% +each other so i keep giving them in a + + + align:start position:0% +each other so i keep giving them in a +multiple small exercises in which + + align:start position:0% +multiple small exercises in which + + + align:start position:0% +multiple small exercises in which +time and time again they begin with + + align:start position:0% +time and time again they begin with + + + align:start position:0% +time and time again they begin with +themselves and they begin by saying how + + align:start position:0% +themselves and they begin by saying how + + + align:start position:0% +themselves and they begin by saying how +do i see + + align:start position:0% +do i see + + + align:start position:0% +do i see +or even to write that i want to just + + align:start position:0% +or even to write that i want to just + + + align:start position:0% +or even to write that i want to just +think about multiple voices what does it + + align:start position:0% +think about multiple voices what does it + + + align:start position:0% +think about multiple voices what does it +mean + + align:start position:0% +mean + + + align:start position:0% +mean +to think of writing as not just merely + + align:start position:0% +to think of writing as not just merely + + + align:start position:0% +to think of writing as not just merely +speaking but as a way of integrating + + align:start position:0% +speaking but as a way of integrating + + + align:start position:0% +speaking but as a way of integrating +your voice with the voice of others + + align:start position:0% +your voice with the voice of others + + + align:start position:0% +your voice with the voice of others +what are other people's ways of telling + + align:start position:0% +what are other people's ways of telling + + + align:start position:0% +what are other people's ways of telling +your stories and how can you + + align:start position:0% +your stories and how can you + + + align:start position:0% +your stories and how can you +tell a story about them you know your + + align:start position:0% +tell a story about them you know your + + + align:start position:0% +tell a story about them you know your +understanding of their story + + align:start position:0% +understanding of their story + + + align:start position:0% +understanding of their story +but in a way that you know fully honors + + align:start position:0% +but in a way that you know fully honors + + + align:start position:0% +but in a way that you know fully honors +them telling their own story + + align:start position:0% +them telling their own story + + + align:start position:0% +them telling their own story +and that seems like such a huge task for + + align:start position:0% +and that seems like such a huge task for + + + align:start position:0% +and that seems like such a huge task for +people and so i begin by saying oh let's + + align:start position:0% +people and so i begin by saying oh let's + + + align:start position:0% +people and so i begin by saying oh let's +play critical karaoke + + align:start position:0% +play critical karaoke + + + align:start position:0% +play critical karaoke +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +garnet adopted this practice from a + + align:start position:0% +garnet adopted this practice from a + + + align:start position:0% +garnet adopted this practice from a +music conference he attended + + align:start position:0% +music conference he attended + + + align:start position:0% +music conference he attended +where attendees got to speak about a + + align:start position:0% +where attendees got to speak about a + + + align:start position:0% +where attendees got to speak about a +song as the song played + + align:start position:0% +song as the song played + + + align:start position:0% +song as the song played +i sat in on one of his classes and + + align:start position:0% +i sat in on one of his classes and + + + align:start position:0% +i sat in on one of his classes and +observed critical karaoke in action + + align:start position:0% +observed critical karaoke in action + + + align:start position:0% +observed critical karaoke in action +it was one of the most powerful teaching + + align:start position:0% +it was one of the most powerful teaching + + + align:start position:0% +it was one of the most powerful teaching +methods i've seen yet + + align:start position:0% +methods i've seen yet + + + align:start position:0% +methods i've seen yet +for capturing how we contain each other + + align:start position:0% + + + + align:start position:0% + +they begin by starting to say this is + + align:start position:0% +they begin by starting to say this is + + + align:start position:0% +they begin by starting to say this is +what the song is about or this is why + + align:start position:0% +what the song is about or this is why + + + align:start position:0% +what the song is about or this is why +it's + + align:start position:0% +it's + + + align:start position:0% +it's +relates to this particular issue or my + + align:start position:0% +relates to this particular issue or my + + + align:start position:0% +relates to this particular issue or my +thinking on this issue + + align:start position:0% +thinking on this issue + + + align:start position:0% +thinking on this issue +and you're hearing them speak about the + + align:start position:0% +and you're hearing them speak about the + + + align:start position:0% +and you're hearing them speak about the +song but tying the song to a larger + + align:start position:0% +song but tying the song to a larger + + + align:start position:0% +song but tying the song to a larger +issue that they're thinking about and + + align:start position:0% +issue that they're thinking about and + + + align:start position:0% +issue that they're thinking about and +then + + align:start position:0% +then + + + align:start position:0% +then +speaking about lyrics of the song or + + align:start position:0% +speaking about lyrics of the song or + + + align:start position:0% +speaking about lyrics of the song or +something the song does + + align:start position:0% +something the song does + + + align:start position:0% +something the song does +and at that point their voice phrase out + + align:start position:0% +and at that point their voice phrase out + + + align:start position:0% +and at that point their voice phrase out +and you hear + + align:start position:0% +and you hear + + + align:start position:0% +and you hear +the song the songs notes or the songs + + align:start position:0% +the song the songs notes or the songs + + + align:start position:0% +the song the songs notes or the songs +lyrics come in and + + align:start position:0% +lyrics come in and + + + align:start position:0% +lyrics come in and +it teaches them in a fun way you know + + align:start position:0% +it teaches them in a fun way you know + + + align:start position:0% +it teaches them in a fun way you know +how to begin to think about + + align:start position:0% +how to begin to think about + + + align:start position:0% +how to begin to think about +interweaving my voice with the voice of + + align:start position:0% +interweaving my voice with the voice of + + + align:start position:0% +interweaving my voice with the voice of +others how to speak + + align:start position:0% +others how to speak + + + align:start position:0% +others how to speak +alongside others rather than about + + align:start position:0% +alongside others rather than about + + + align:start position:0% +alongside others rather than about +others in which + + align:start position:0% +others in which + + + align:start position:0% +others in which +you're speaking about them denies them + + align:start position:0% +you're speaking about them denies them + + + align:start position:0% +you're speaking about them denies them +agency + + align:start position:0% +agency + + + align:start position:0% +agency +and dignity critical karaoke + + align:start position:0% +and dignity critical karaoke + + + align:start position:0% +and dignity critical karaoke +is one example of how garnet is + + align:start position:0% +is one example of how garnet is + + + align:start position:0% +is one example of how garnet is +rethinking how we engage students in + + align:start position:0% +rethinking how we engage students in + + + align:start position:0% +rethinking how we engage students in +learning about racism + + align:start position:0% +learning about racism + + + align:start position:0% +learning about racism +but there's something even more profound + + align:start position:0% +but there's something even more profound + + + align:start position:0% +but there's something even more profound +at work in his teaching + + align:start position:0% +at work in his teaching + + + align:start position:0% +at work in his teaching +he's fundamentally re-imagining a + + align:start position:0% +he's fundamentally re-imagining a + + + align:start position:0% +he's fundamentally re-imagining a +framework + + align:start position:0% +framework + + + align:start position:0% +framework +for how we approach the topic with + + align:start position:0% +for how we approach the topic with + + + align:start position:0% +for how we approach the topic with +students viewing off a well-trod + + align:start position:0% +students viewing off a well-trod + + + align:start position:0% +students viewing off a well-trod +sequential strategy and jumping into a + + align:start position:0% +sequential strategy and jumping into a + + + align:start position:0% +sequential strategy and jumping into a +mind + + align:start position:0% +mind + + + align:start position:0% +mind +opening matrix of connections + + align:start position:0% +opening matrix of connections + + + align:start position:0% +opening matrix of connections +i'd looked at a lot of syllabuses i went + + align:start position:0% +i'd looked at a lot of syllabuses i went + + + align:start position:0% +i'd looked at a lot of syllabuses i went +online and tried to find every syllabus + + align:start position:0% +online and tried to find every syllabus + + + align:start position:0% +online and tried to find every syllabus +i could find that was available + + align:start position:0% +i could find that was available + + + align:start position:0% +i could find that was available +at different universities about race and + + align:start position:0% +at different universities about race and + + + align:start position:0% +at different universities about race and +racism + + align:start position:0% +racism + + + align:start position:0% +racism +in america particularly in american + + align:start position:0% +in america particularly in american + + + align:start position:0% +in america particularly in american +cities and the + + align:start position:0% +cities and the + + + align:start position:0% +cities and the +approach tends to be to have it + + align:start position:0% +approach tends to be to have it + + + align:start position:0% +approach tends to be to have it +organized by issue + + align:start position:0% +organized by issue + + + align:start position:0% +organized by issue +this week we will discuss slavery these + + align:start position:0% +this week we will discuss slavery these + + + align:start position:0% +this week we will discuss slavery these +weeks we will discuss slavery then + + align:start position:0% +weeks we will discuss slavery then + + + align:start position:0% +weeks we will discuss slavery then +emancipation + + align:start position:0% +emancipation + + + align:start position:0% +emancipation +the civil rights movement mass + + align:start position:0% +the civil rights movement mass + + + align:start position:0% +the civil rights movement mass +incarceration + + align:start position:0% +incarceration + + + align:start position:0% +incarceration +policing education environmental + + align:start position:0% +policing education environmental + + + align:start position:0% +policing education environmental +injustice in housing in development + + align:start position:0% +injustice in housing in development + + + align:start position:0% +injustice in housing in development +education and i found what actually + + align:start position:0% +education and i found what actually + + + align:start position:0% +education and i found what actually +happened was that + + align:start position:0% +happened was that + + + align:start position:0% +happened was that +when i began discussing by way of + + align:start position:0% +when i began discussing by way of + + + align:start position:0% +when i began discussing by way of +issues then people in in a so often + + align:start position:0% +issues then people in in a so often + + + align:start position:0% +issues then people in in a so often +organized around + + align:start position:0% +organized around + + + align:start position:0% +organized around +issues and then they feel like they had + + align:start position:0% +issues and then they feel like they had + + + align:start position:0% +issues and then they feel like they had +to resolve it at that moment + + align:start position:0% +to resolve it at that moment + + + align:start position:0% +to resolve it at that moment +so he decided to shift the focus it + + align:start position:0% +so he decided to shift the focus it + + + align:start position:0% +so he decided to shift the focus it +became + + align:start position:0% +became + + + align:start position:0% +became +on inequality on freedom + + align:start position:0% +on inequality on freedom + + + align:start position:0% +on inequality on freedom +on joy on pessimism and hope on + + align:start position:0% +on joy on pessimism and hope on + + + align:start position:0% +on joy on pessimism and hope on +belonging + + align:start position:0% +belonging + + + align:start position:0% +belonging +on mythology on unrest + + align:start position:0% +on mythology on unrest + + + align:start position:0% +on mythology on unrest +on violence on resistance + + align:start position:0% +on violence on resistance + + + align:start position:0% +on violence on resistance +on imagination it was an invitation to + + align:start position:0% +on imagination it was an invitation to + + + align:start position:0% +on imagination it was an invitation to +say + + align:start position:0% +say + + + align:start position:0% +say +we will not figure out mass + + align:start position:0% +we will not figure out mass + + + align:start position:0% +we will not figure out mass +incarceration in one week + + align:start position:0% +incarceration in one week + + + align:start position:0% +incarceration in one week +that it became a way of spreading the + + align:start position:0% +that it became a way of spreading the + + + align:start position:0% +that it became a way of spreading the +issues + + align:start position:0% +issues + + + align:start position:0% +issues +out and so mass incarceration would come + + align:start position:0% +out and so mass incarceration would come + + + align:start position:0% +out and so mass incarceration would come +up + + align:start position:0% +up + + + align:start position:0% +up +when we were talking about inequality + + align:start position:0% +when we were talking about inequality + + + align:start position:0% +when we were talking about inequality +and then + + align:start position:0% +and then + + + align:start position:0% +and then +it would return again when we're talking + + align:start position:0% +it would return again when we're talking + + + align:start position:0% +it would return again when we're talking +about hope and pessimism + + align:start position:0% +about hope and pessimism + + + align:start position:0% +about hope and pessimism +and then it would return again we were + + align:start position:0% +and then it would return again we were + + + align:start position:0% +and then it would return again we were +talking about resistance + + align:start position:0% +talking about resistance + + + align:start position:0% +talking about resistance +and they then had the invitation to + + align:start position:0% +and they then had the invitation to + + + align:start position:0% +and they then had the invitation to +you know have spent a whole semester to + + align:start position:0% +you know have spent a whole semester to + + + align:start position:0% +you know have spent a whole semester to +think through this thing they then + + align:start position:0% +think through this thing they then + + + align:start position:0% +think through this thing they then +suddenly recognize the ways in which we + + align:start position:0% +suddenly recognize the ways in which we + + + align:start position:0% +suddenly recognize the ways in which we +thought we were all bound up in each + + align:start position:0% +thought we were all bound up in each + + + align:start position:0% +thought we were all bound up in each +other + + align:start position:0% +other + + + align:start position:0% +other +the issues themselves were all bound up + + align:start position:0% +the issues themselves were all bound up + + + align:start position:0% +the issues themselves were all bound up +in each other as you began to think + + align:start position:0% +in each other as you began to think + + + align:start position:0% +in each other as you began to think +about + + align:start position:0% +about + + + align:start position:0% +about +you know issues having to do with mass + + align:start position:0% +you know issues having to do with mass + + + align:start position:0% +you know issues having to do with mass +incarceration you were also thinking + + align:start position:0% +incarceration you were also thinking + + + align:start position:0% +incarceration you were also thinking +about + + align:start position:0% +about + + + align:start position:0% +about +issues having to do with policing you + + align:start position:0% +issues having to do with policing you + + + align:start position:0% +issues having to do with policing you +were thinking about issues having to do + + align:start position:0% +were thinking about issues having to do + + + align:start position:0% +were thinking about issues having to do +with housing you were thinking about + + align:start position:0% +with housing you were thinking about + + + align:start position:0% +with housing you were thinking about +education you were thinking about + + align:start position:0% +education you were thinking about + + + align:start position:0% +education you were thinking about +investment and disinvestment + + align:start position:0% +investment and disinvestment + + + align:start position:0% +investment and disinvestment +and suddenly instead of in a + + align:start position:0% +and suddenly instead of in a + + + align:start position:0% +and suddenly instead of in a +teleological line which is so often how + + align:start position:0% +teleological line which is so often how + + + align:start position:0% +teleological line which is so often how +we talk about race and what i recognize + + align:start position:0% +we talk about race and what i recognize + + + align:start position:0% +we talk about race and what i recognize +with a lot of the syllabuses + + align:start position:0% +with a lot of the syllabuses + + + align:start position:0% +with a lot of the syllabuses +it's you know and it's in a moving from + + align:start position:0% +it's you know and it's in a moving from + + + align:start position:0% +it's you know and it's in a moving from +unfreedom to freedom with occasional + + align:start position:0% +unfreedom to freedom with occasional + + + align:start position:0% +unfreedom to freedom with occasional +hiccups + + align:start position:0% +hiccups + + + align:start position:0% +hiccups +that was the wrong way to think about it + + align:start position:0% +that was the wrong way to think about it + + + align:start position:0% +that was the wrong way to think about it +rather than a matrix in which + + align:start position:0% +rather than a matrix in which + + + align:start position:0% +rather than a matrix in which +everything was deeply connected to the + + align:start position:0% +everything was deeply connected to the + + + align:start position:0% +everything was deeply connected to the +other + + align:start position:0% + + + + align:start position:0% + +garnet views the act of creating his + + align:start position:0% +garnet views the act of creating his + + + align:start position:0% +garnet views the act of creating his +syllabus as being + + align:start position:0% +syllabus as being + + + align:start position:0% +syllabus as being +very similar to writing the narrative of + + align:start position:0% +very similar to writing the narrative of + + + align:start position:0% +very similar to writing the narrative of +a story + + align:start position:0% +a story + + + align:start position:0% +a story +one thing i do with the syllabus is that + + align:start position:0% +one thing i do with the syllabus is that + + + align:start position:0% +one thing i do with the syllabus is that +i make the syllabus + + align:start position:0% +i make the syllabus + + + align:start position:0% +i make the syllabus +a story in and of itself that too often + + align:start position:0% +a story in and of itself that too often + + + align:start position:0% +a story in and of itself that too often +syllabuses are schematic that they're + + align:start position:0% +syllabuses are schematic that they're + + + align:start position:0% +syllabuses are schematic that they're +almost + + align:start position:0% +almost + + + align:start position:0% +almost +disconnected rooms in a house or they're + + align:start position:0% +disconnected rooms in a house or they're + + + align:start position:0% +disconnected rooms in a house or they're +treated like rooms in this mansion + + align:start position:0% +treated like rooms in this mansion + + + align:start position:0% +treated like rooms in this mansion +that there's like a site or it can go + + align:start position:0% +that there's like a site or it can go + + + align:start position:0% +that there's like a site or it can go +from one to the other and i think of the + + align:start position:0% +from one to the other and i think of the + + + align:start position:0% +from one to the other and i think of the +syllabus + + align:start position:0% +syllabus + + + align:start position:0% +syllabus +it's like one big hall and in that in a + + align:start position:0% +it's like one big hall and in that in a + + + align:start position:0% +it's like one big hall and in that in a +big hall where different gatherings + + align:start position:0% +big hall where different gatherings + + + align:start position:0% +big hall where different gatherings +you can go and then you can come back + + align:start position:0% +you can go and then you can come back + + + align:start position:0% +you can go and then you can come back +and so you don't leave one room and you + + align:start position:0% +and so you don't leave one room and you + + + align:start position:0% +and so you don't leave one room and you +never return and so i + + align:start position:0% +never return and so i + + + align:start position:0% +never return and so i +treat the syllabus like a full story and + + align:start position:0% +treat the syllabus like a full story and + + + align:start position:0% +treat the syllabus like a full story and +so there are songs we will hear + + align:start position:0% +so there are songs we will hear + + + align:start position:0% +so there are songs we will hear +and then we hear them again later on in + + align:start position:0% +and then we hear them again later on in + + + align:start position:0% +and then we hear them again later on in +in a different context there are poems + + align:start position:0% +in a different context there are poems + + + align:start position:0% +in a different context there are poems +that we will read and we read them again + + align:start position:0% +that we will read and we read them again + + + align:start position:0% +that we will read and we read them again +later on + + align:start position:0% +later on + + + align:start position:0% +later on +you know or there is one particular + + align:start position:0% +you know or there is one particular + + + align:start position:0% +you know or there is one particular +article that they'll read on the second + + align:start position:0% +article that they'll read on the second + + + align:start position:0% +article that they'll read on the second +week + + align:start position:0% +week + + + align:start position:0% +week +and then we read it again on the seventh + + align:start position:0% +and then we read it again on the seventh + + + align:start position:0% +and then we read it again on the seventh +week which seems only just when they're + + align:start position:0% +week which seems only just when they're + + + align:start position:0% +week which seems only just when they're +like what didn't we read this again + + align:start position:0% +like what didn't we read this again + + + align:start position:0% +like what didn't we read this again +and then they suddenly read it with new + + align:start position:0% +and then they suddenly read it with new + + + align:start position:0% +and then they suddenly read it with new +eyes and it becomes a way of seeing + + align:start position:0% +eyes and it becomes a way of seeing + + + align:start position:0% +eyes and it becomes a way of seeing +in it as a story and then i think of + + align:start position:0% +in it as a story and then i think of + + + align:start position:0% +in it as a story and then i think of +things as late motifs to say + + align:start position:0% +things as late motifs to say + + + align:start position:0% +things as late motifs to say +we will begin discussing this but then + + align:start position:0% +we will begin discussing this but then + + + align:start position:0% +we will begin discussing this but then +we will stop + + align:start position:0% +we will stop + + + align:start position:0% +we will stop +here and so they get the taste of it and + + align:start position:0% +here and so they get the taste of it and + + + align:start position:0% +here and so they get the taste of it and +it comes back more full-blown later on + + align:start position:0% +it comes back more full-blown later on + + + align:start position:0% +it comes back more full-blown later on +and so i think of it as a particular + + align:start position:0% +and so i think of it as a particular + + + align:start position:0% +and so i think of it as a particular +narrative arc so treat the semester + + align:start position:0% +narrative arc so treat the semester + + + align:start position:0% +narrative arc so treat the semester +itself + + align:start position:0% +itself + + + align:start position:0% +itself +like a narrative arc + + align:start position:0% + + + + align:start position:0% + +for garnet the syllabus must be as + + align:start position:0% +for garnet the syllabus must be as + + + align:start position:0% +for garnet the syllabus must be as +multi-dimensional as the students + + align:start position:0% +multi-dimensional as the students + + + align:start position:0% +multi-dimensional as the students +themselves + + align:start position:0% +themselves + + + align:start position:0% +themselves +incorporating opportunities for joy and + + align:start position:0% +incorporating opportunities for joy and + + + align:start position:0% +incorporating opportunities for joy and +reflection + + align:start position:0% +reflection + + + align:start position:0% +reflection +and it should also be shaped by the + + align:start position:0% +and it should also be shaped by the + + + align:start position:0% +and it should also be shaped by the +students voices + + align:start position:0% +students voices + + + align:start position:0% +students voices +every week they encounter scent of + + align:start position:0% +every week they encounter scent of + + + align:start position:0% +every week they encounter scent of +comedy and they encounter poetry + + align:start position:0% +comedy and they encounter poetry + + + align:start position:0% +comedy and they encounter poetry +they encounter song they encounter + + align:start position:0% +they encounter song they encounter + + + align:start position:0% +they encounter song they encounter +film they encounter short story in a + + align:start position:0% +film they encounter short story in a + + + align:start position:0% +film they encounter short story in a +fiction + + align:start position:0% +fiction + + + align:start position:0% +fiction +essay reportage academic article + + align:start position:0% +essay reportage academic article + + + align:start position:0% +essay reportage academic article +and so there are a variety of voices and + + align:start position:0% +and so there are a variety of voices and + + + align:start position:0% +and so there are a variety of voices and +it's an invitation + + align:start position:0% +it's an invitation + + + align:start position:0% +it's an invitation +to understand the world in + + align:start position:0% +to understand the world in + + + align:start position:0% +to understand the world in +many ways the world presents itself to + + align:start position:0% +many ways the world presents itself to + + + align:start position:0% +many ways the world presents itself to +you knowledge + + align:start position:0% +you knowledge + + + align:start position:0% +you knowledge +one of the fascinating things about + + align:start position:0% +one of the fascinating things about + + + align:start position:0% +one of the fascinating things about +teaching a course like this + + align:start position:0% +teaching a course like this + + + align:start position:0% +teaching a course like this +is you know how do you keep yourself + + align:start position:0% +is you know how do you keep yourself + + + align:start position:0% +is you know how do you keep yourself +open to being taught + + align:start position:0% +open to being taught + + + align:start position:0% +open to being taught +by the students in thinking about + + align:start position:0% +by the students in thinking about + + + align:start position:0% +by the students in thinking about +this balancing of many voices in the + + align:start position:0% +this balancing of many voices in the + + + align:start position:0% +this balancing of many voices in the +voices from the past or voices near and + + align:start position:0% +voices from the past or voices near and + + + align:start position:0% +voices from the past or voices near and +far + + align:start position:0% +far + + + align:start position:0% +far +in it can you in accommodate their + + align:start position:0% +in it can you in accommodate their + + + align:start position:0% +in it can you in accommodate their +voices and + + align:start position:0% +voices and + + + align:start position:0% +voices and +so in a class like this one has to be + + align:start position:0% +so in a class like this one has to be + + + align:start position:0% +so in a class like this one has to be +very open + + align:start position:0% +very open + + + align:start position:0% +very open +and you know ready to listen and to have + + align:start position:0% +and you know ready to listen and to have + + + align:start position:0% +and you know ready to listen and to have +students express their own ultimate in + + align:start position:0% +students express their own ultimate in + + + align:start position:0% +students express their own ultimate in +shaping it and part of + + align:start position:0% +shaping it and part of + + + align:start position:0% +shaping it and part of +you know because there's also a great + + align:start position:0% +you know because there's also a great + + + align:start position:0% +you know because there's also a great +irony not doing that because + + align:start position:0% +irony not doing that because + + + align:start position:0% +irony not doing that because +one of the things at the heart of racism + + align:start position:0% +one of the things at the heart of racism + + + align:start position:0% +one of the things at the heart of racism +is the denial of autonomy + + align:start position:0% +is the denial of autonomy + + + align:start position:0% +is the denial of autonomy +to others the ways in which many times + + align:start position:0% +to others the ways in which many times + + + align:start position:0% +to others the ways in which many times +you know + + align:start position:0% +you know + + + align:start position:0% +you know +authorities used to stamp on + + align:start position:0% +authorities used to stamp on + + + align:start position:0% +authorities used to stamp on +autonomy and for me not to listen not to + + align:start position:0% +autonomy and for me not to listen not to + + + align:start position:0% +autonomy and for me not to listen not to +have them + + align:start position:0% +have them + + + align:start position:0% +have them +be active agents in shaping and + + align:start position:0% +be active agents in shaping and + + + align:start position:0% +be active agents in shaping and +reshaping + + align:start position:0% +reshaping + + + align:start position:0% +reshaping +the class would then be a version of + + align:start position:0% +the class would then be a version of + + + align:start position:0% +the class would then be a version of +that + + align:start position:0% +that + + + align:start position:0% +that +of you know authority denying autonomy + + align:start position:0% +of you know authority denying autonomy + + + align:start position:0% +of you know authority denying autonomy +to close i'd like to leave you with a + + align:start position:0% +to close i'd like to leave you with a + + + align:start position:0% +to close i'd like to leave you with a +quote from garnett + + align:start position:0% +quote from garnett + + + align:start position:0% +quote from garnett +about joy and resilience + + align:start position:0% +about joy and resilience + + + align:start position:0% +about joy and resilience +one of the things i had made a decision + + align:start position:0% +one of the things i had made a decision + + + align:start position:0% +one of the things i had made a decision +very early is that i am not the sum + + align:start position:0% +very early is that i am not the sum + + + align:start position:0% +very early is that i am not the sum +total of what happens to me which is + + align:start position:0% +total of what happens to me which is + + + align:start position:0% +total of what happens to me which is +something i in a keeper manning students + + align:start position:0% +something i in a keeper manning students + + + align:start position:0% +something i in a keeper manning students +you know as they study about race and + + align:start position:0% +you know as they study about race and + + + align:start position:0% +you know as they study about race and +racism that people are more than the sum + + align:start position:0% +racism that people are more than the sum + + + align:start position:0% +racism that people are more than the sum +total of the awful things that have + + align:start position:0% +total of the awful things that have + + + align:start position:0% +total of the awful things that have +happened to them + + align:start position:0% +happened to them + + + align:start position:0% +happened to them +that there's a possibilities you know of + + align:start position:0% +that there's a possibilities you know of + + + align:start position:0% +that there's a possibilities you know of +joy of resistance + + align:start position:0% +joy of resistance + + + align:start position:0% +joy of resistance +you know of moving to the world not + + align:start position:0% +you know of moving to the world not + + + align:start position:0% +you know of moving to the world not +ignoring the awful things that have + + align:start position:0% +ignoring the awful things that have + + + align:start position:0% +ignoring the awful things that have +happened to you + + align:start position:0% +happened to you + + + align:start position:0% +happened to you +but of determining that you will not let + + align:start position:0% +but of determining that you will not let + + + align:start position:0% +but of determining that you will not let +you know these awful things + + align:start position:0% +you know these awful things + + + align:start position:0% +you know these awful things +define and constrain + + align:start position:0% +define and constrain + + + align:start position:0% +define and constrain +if you're ready to learn more about + + align:start position:0% +if you're ready to learn more about + + + align:start position:0% +if you're ready to learn more about +writing and teaching about race and + + align:start position:0% +writing and teaching about race and + + + align:start position:0% +writing and teaching about race and +racism + + align:start position:0% +racism + + + align:start position:0% +racism +and unpacking the story of the american + + align:start position:0% +and unpacking the story of the american + + + align:start position:0% +and unpacking the story of the american +city + + align:start position:0% +city + + + align:start position:0% +city +you'll soon be able to find garnett + + align:start position:0% +you'll soon be able to find garnett + + + align:start position:0% +you'll soon be able to find garnett +cadigan's teaching materials + + align:start position:0% +cadigan's teaching materials + + + align:start position:0% +cadigan's teaching materials +on our mit open courseware website our + + align:start position:0% +on our mit open courseware website our + + + align:start position:0% +on our mit open courseware website our +materials are always free + + align:start position:0% +materials are always free + + + align:start position:0% +materials are always free +if you're an educator who remixes the + + align:start position:0% +if you're an educator who remixes the + + + align:start position:0% +if you're an educator who remixes the +resources in your own teaching + + align:start position:0% +resources in your own teaching + + + align:start position:0% +resources in your own teaching +please call or write to us to share your + + align:start position:0% +please call or write to us to share your + + + align:start position:0% +please call or write to us to share your +story you'll help inspire others + + align:start position:0% +story you'll help inspire others + + + align:start position:0% +story you'll help inspire others +thank you so much for listening signing + + align:start position:0% +thank you so much for listening signing + + + align:start position:0% +thank you so much for listening signing +off from cambridge massachusetts + + align:start position:0% +off from cambridge massachusetts + + + align:start position:0% +off from cambridge massachusetts +i'm sarah hansen from mit open + + align:start position:0% + + + + align:start position:0% + +courseware + + align:start position:0% + + + + align:start position:0% + +mom passed the car \ No newline at end of file diff --git a/QNchkFi-VrE.txt b/QNchkFi-VrE.txt new file mode 100644 index 0000000000000000000000000000000000000000..7f9c166f90e4a7112ebc510002e6b5c00d20c202 --- /dev/null +++ b/QNchkFi-VrE.txt @@ -0,0 +1,1267 @@ +align:start position:0% + +well good morning Navajo environmental + + align:start position:0% +well good morning Navajo environmental + + + align:start position:0% +well good morning Navajo environmental +agency members given the proposed + + align:start position:0% +agency members given the proposed + + + align:start position:0% +agency members given the proposed +revitalization of the nuclear power + + align:start position:0% +revitalization of the nuclear power + + + align:start position:0% +revitalization of the nuclear power +industry and the hints that uranium + + align:start position:0% +industry and the hints that uranium + + + align:start position:0% +industry and the hints that uranium +mining might be revitalized in the + + align:start position:0% +mining might be revitalized in the + + + align:start position:0% +mining might be revitalized in the +region there's a growing level of + + align:start position:0% +region there's a growing level of + + + align:start position:0% +region there's a growing level of +concern amongst the agency members + + align:start position:0% +concern amongst the agency members + + + align:start position:0% +concern amongst the agency members +regarding what this means for us + + align:start position:0% +regarding what this means for us + + + align:start position:0% +regarding what this means for us +especially given the controversy of + + align:start position:0% +especially given the controversy of + + + align:start position:0% +especially given the controversy of +historical precedents that happen in + + align:start position:0% +historical precedents that happen in + + + align:start position:0% +historical precedents that happen in +this area in the 1960s I'm here today to + + align:start position:0% +this area in the 1960s I'm here today to + + + align:start position:0% +this area in the 1960s I'm here today to +explain amongst the various measures + + align:start position:0% +explain amongst the various measures + + + align:start position:0% +explain amongst the various measures +that we are implementing why local + + align:start position:0% +that we are implementing why local + + + align:start position:0% +that we are implementing why local +knowledge should be given serious + + align:start position:0% +knowledge should be given serious + + + align:start position:0% +knowledge should be given serious +consideration and why the mi we should + + align:start position:0% +consideration and why the mi we should + + + align:start position:0% +consideration and why the mi we should +actually be involving the local members + + align:start position:0% +actually be involving the local members + + + align:start position:0% +actually be involving the local members +of community in the process of + + align:start position:0% +of community in the process of + + + align:start position:0% +of community in the process of +developments of uranium mining now + + align:start position:0% +developments of uranium mining now + + + align:start position:0% +developments of uranium mining now +firstly the involvement of local + + align:start position:0% +firstly the involvement of local + + + align:start position:0% +firstly the involvement of local +knowledge improves and enriches the + + align:start position:0% +knowledge improves and enriches the + + + align:start position:0% +knowledge improves and enriches the +scientific process problem framing is an + + align:start position:0% +scientific process problem framing is an + + + align:start position:0% +scientific process problem framing is an +inherently subjective process and it's + + align:start position:0% +inherently subjective process and it's + + + align:start position:0% +inherently subjective process and it's +not something that science can solve on + + align:start position:0% +not something that science can solve on + + + align:start position:0% +not something that science can solve on +its own when we look at you know what + + align:start position:0% +its own when we look at you know what + + + align:start position:0% +its own when we look at you know what +exactly are the problems who are the + + align:start position:0% +exactly are the problems who are the + + + align:start position:0% +exactly are the problems who are the +people instead who exactly couldn't be + + align:start position:0% +people instead who exactly couldn't be + + + align:start position:0% +people instead who exactly couldn't be +affected and what do they think about it + + align:start position:0% +affected and what do they think about it + + + align:start position:0% +affected and what do they think about it +these are questions that don't lie in + + align:start position:0% +these are questions that don't lie in + + + align:start position:0% +these are questions that don't lie in +science but rather in the people and + + align:start position:0% +science but rather in the people and + + + align:start position:0% +science but rather in the people and +that's why we must move away from + + align:start position:0% +that's why we must move away from + + + align:start position:0% +that's why we must move away from +thinking about a positivist view of + + align:start position:0% +thinking about a positivist view of + + + align:start position:0% +thinking about a positivist view of +science that science holds all the + + align:start position:0% +science that science holds all the + + + align:start position:0% +science that science holds all the +answers and involve the people and what + + align:start position:0% +answers and involve the people and what + + + align:start position:0% +answers and involve the people and what +they think about it and secondly we + + align:start position:0% +they think about it and secondly we + + + align:start position:0% +they think about it and secondly we +understand for many stories in history + + align:start position:0% +understand for many stories in history + + + align:start position:0% +understand for many stories in history +that science is inherently uncertain + + align:start position:0% +that science is inherently uncertain + + + align:start position:0% +that science is inherently uncertain +there are uncertainties involved in + + align:start position:0% +there are uncertainties involved in + + + align:start position:0% +there are uncertainties involved in +quantifying effects of various measures + + align:start position:0% +quantifying effects of various measures + + + align:start position:0% +quantifying effects of various measures +there uncertainties involved in + + align:start position:0% +there uncertainties involved in + + + align:start position:0% +there uncertainties involved in +determining what impacts the particular + + align:start position:0% +determining what impacts the particular + + + align:start position:0% +determining what impacts the particular +activity in this case remaining will + + align:start position:0% +activity in this case remaining will + + + align:start position:0% +activity in this case remaining will +have on the future generations and + + align:start position:0% +have on the future generations and + + + align:start position:0% +have on the future generations and +therefore local knowledge brings in a + + align:start position:0% +therefore local knowledge brings in a + + + align:start position:0% +therefore local knowledge brings in a +important element that science has + + align:start position:0% +important element that science has + + + align:start position:0% +important element that science has +that's not it's not able to and this is + + align:start position:0% +that's not it's not able to and this is + + + align:start position:0% +that's not it's not able to and this is +ultimately patterns and trends in time + + align:start position:0% +ultimately patterns and trends in time + + + align:start position:0% +ultimately patterns and trends in time +and space that people living in the area + + align:start position:0% +and space that people living in the area + + + align:start position:0% +and space that people living in the area +have been observing over decades and + + align:start position:0% +have been observing over decades and + + + align:start position:0% +have been observing over decades and +over a large area ultimately if you + + align:start position:0% +over a large area ultimately if you + + + align:start position:0% +over a large area ultimately if you +bring in scientists to examine the + + align:start position:0% +bring in scientists to examine the + + + align:start position:0% +bring in scientists to examine the +environmental impact of uranium mining + + align:start position:0% +environmental impact of uranium mining + + + align:start position:0% +environmental impact of uranium mining +what will be captured often tends to be + + align:start position:0% +what will be captured often tends to be + + + align:start position:0% +what will be captured often tends to be +a screen shot or know a shot in time of + + align:start position:0% +a screen shot or know a shot in time of + + + align:start position:0% +a screen shot or know a shot in time of +what what extra days will happen whereas + + align:start position:0% +what what extra days will happen whereas + + + align:start position:0% +what what extra days will happen whereas +these people have had their benefits + + align:start position:0% +these people have had their benefits + + + align:start position:0% +these people have had their benefits +of decades of experience and they will + + align:start position:0% +of decades of experience and they will + + + align:start position:0% +of decades of experience and they will +be able to tell us what's most likely to + + align:start position:0% +be able to tell us what's most likely to + + + align:start position:0% +be able to tell us what's most likely to +happen over time and space + + align:start position:0% +happen over time and space + + + align:start position:0% +happen over time and space +and lastly democratization the the + + align:start position:0% +and lastly democratization the the + + + align:start position:0% +and lastly democratization the the +marina mining activities that are being + + align:start position:0% +marina mining activities that are being + + + align:start position:0% +marina mining activities that are being +taken do not involve only the scientists + + align:start position:0% +taken do not involve only the scientists + + + align:start position:0% +taken do not involve only the scientists +are only the industry members but also + + align:start position:0% +are only the industry members but also + + + align:start position:0% +are only the industry members but also +the people and it is important to ensure + + align:start position:0% +the people and it is important to ensure + + + align:start position:0% +the people and it is important to ensure +that their views are being heard and + + align:start position:0% +that their views are being heard and + + + align:start position:0% +that their views are being heard and +have been taken into account in the + + align:start position:0% +have been taken into account in the + + + align:start position:0% +have been taken into account in the +scientific process of course there will + + align:start position:0% +scientific process of course there will + + + align:start position:0% +scientific process of course there will +be opposition to such views firstly + + align:start position:0% +be opposition to such views firstly + + + align:start position:0% +be opposition to such views firstly +people might say that you know in the + + align:start position:0% +people might say that you know in the + + + align:start position:0% +people might say that you know in the +past the reason for these problems were + + align:start position:0% +past the reason for these problems were + + + align:start position:0% +past the reason for these problems were +the proper rules and regulations for + + align:start position:0% +the proper rules and regulations for + + + align:start position:0% +the proper rules and regulations for +ignore and the adverse impacts were + + align:start position:0% +ignore and the adverse impacts were + + + align:start position:0% +ignore and the adverse impacts were +actually minimal I would argue that the + + align:start position:0% +actually minimal I would argue that the + + + align:start position:0% +actually minimal I would argue that the +reason why proper rules and regulations + + align:start position:0% +reason why proper rules and regulations + + + align:start position:0% +reason why proper rules and regulations +were ignored it's the fact that these + + align:start position:0% +were ignored it's the fact that these + + + align:start position:0% +were ignored it's the fact that these +people were not actually involved in the + + align:start position:0% +people were not actually involved in the + + + align:start position:0% +people were not actually involved in the +development of these rules and + + align:start position:0% +development of these rules and + + + align:start position:0% +development of these rules and +regulations and also there is a false + + align:start position:0% +regulations and also there is a false + + + align:start position:0% +regulations and also there is a false +dichotomy between scientific knowledge + + align:start position:0% +dichotomy between scientific knowledge + + + align:start position:0% +dichotomy between scientific knowledge +and local knowledge they actually have + + align:start position:0% +and local knowledge they actually have + + + align:start position:0% +and local knowledge they actually have +that where people think that you know + + align:start position:0% +that where people think that you know + + + align:start position:0% +that where people think that you know +scientists are the only ones that + + align:start position:0% +scientists are the only ones that + + + align:start position:0% +scientists are the only ones that +qualified to come up with good science + + align:start position:0% +qualified to come up with good science + + + align:start position:0% +qualified to come up with good science +whereas people who have not been trained + + align:start position:0% +whereas people who have not been trained + + + align:start position:0% +whereas people who have not been trained +in this area will not be able to do so + + align:start position:0% +in this area will not be able to do so + + + align:start position:0% +in this area will not be able to do so +studies have shown in history that a lot + + align:start position:0% +studies have shown in history that a lot + + + align:start position:0% +studies have shown in history that a lot +of this of this view actually stems from + + align:start position:0% +of this of this view actually stems from + + + align:start position:0% +of this of this view actually stems from +the fact that people aren't used to the + + align:start position:0% +the fact that people aren't used to the + + + align:start position:0% +the fact that people aren't used to the +language and a technical terms used in + + align:start position:0% +language and a technical terms used in + + + align:start position:0% +language and a technical terms used in +science but when that barriers crossed + + align:start position:0% +science but when that barriers crossed + + + align:start position:0% +science but when that barriers crossed +that people are not given a critical + + align:start position:0% +that people are not given a critical + + + align:start position:0% +that people are not given a critical +thinking skills and their reasoning + + align:start position:0% +thinking skills and their reasoning + + + align:start position:0% +thinking skills and their reasoning +skills are equally able as trained + + align:start position:0% +skills are equally able as trained + + + align:start position:0% +skills are equally able as trained +scientists to be able to contribute to + + align:start position:0% +scientists to be able to contribute to + + + align:start position:0% +scientists to be able to contribute to +the discussion so ultimately how should + + align:start position:0% +the discussion so ultimately how should + + + align:start position:0% +the discussion so ultimately how should +we ensure that local knowledge is taken + + align:start position:0% +we ensure that local knowledge is taken + + + align:start position:0% +we ensure that local knowledge is taken +seriously how should we incorporate this + + align:start position:0% +seriously how should we incorporate this + + + align:start position:0% +seriously how should we incorporate this +the Indus involves a mindset shift local + + align:start position:0% +the Indus involves a mindset shift local + + + align:start position:0% +the Indus involves a mindset shift local +knowledge does not seek to supplant + + align:start position:0% +knowledge does not seek to supplant + + + align:start position:0% +knowledge does not seek to supplant +scientific knowledge and but rather + + align:start position:0% +scientific knowledge and but rather + + + align:start position:0% +scientific knowledge and but rather +strengthen it we need to move away from + + align:start position:0% +strengthen it we need to move away from + + + align:start position:0% +strengthen it we need to move away from +this false dichotomy and allow locals + + align:start position:0% +this false dichotomy and allow locals + + + align:start position:0% +this false dichotomy and allow locals +and scientists to sit at the table as + + align:start position:0% +and scientists to sit at the table as + + + align:start position:0% +and scientists to sit at the table as +equals + + align:start position:0% +equals + + + align:start position:0% +equals +not because they are equally good at + + align:start position:0% +not because they are equally good at + + + align:start position:0% +not because they are equally good at +something but because it brings + + align:start position:0% +something but because it brings + + + align:start position:0% +something but because it brings +different things to the table they are + + align:start position:0% +different things to the table they are + + + align:start position:0% +different things to the table they are +of equal value we also would like to + + align:start position:0% +of equal value we also would like to + + + align:start position:0% +of equal value we also would like to +recommend that boundary workers be + + align:start position:0% +recommend that boundary workers be + + + align:start position:0% +recommend that boundary workers be +searched for and hired to actually take + + align:start position:0% +searched for and hired to actually take + + + align:start position:0% +searched for and hired to actually take +part in this process boundary workers + + align:start position:0% +part in this process boundary workers + + + align:start position:0% +part in this process boundary workers +meaning people they are not only able to + + align:start position:0% +meaning people they are not only able to + + + align:start position:0% +meaning people they are not only able to +communicate with those on the scientific + + align:start position:0% +communicate with those on the scientific + + + align:start position:0% +communicate with those on the scientific +side of the boundary + + align:start position:0% +side of the boundary + + + align:start position:0% +side of the boundary +also with the local side of the boundary + + align:start position:0% +also with the local side of the boundary + + + align:start position:0% +also with the local side of the boundary +these might be people local locals who + + align:start position:0% +these might be people local locals who + + + align:start position:0% +these might be people local locals who +have been trained in science and who are + + align:start position:0% +have been trained in science and who are + + + align:start position:0% +have been trained in science and who are +not only understand them + + align:start position:0% +not only understand them + + + align:start position:0% +not only understand them +the scientific culture but also the + + align:start position:0% +the scientific culture but also the + + + align:start position:0% +the scientific culture but also the +local culture at the same time people + + align:start position:0% +local culture at the same time people + + + align:start position:0% +local culture at the same time people +just because something is local + + align:start position:0% +just because something is local + + + align:start position:0% +just because something is local +knowledge does not mean that it is right + + align:start position:0% +knowledge does not mean that it is right + + + align:start position:0% +knowledge does not mean that it is right +so in that sense high standards have to + + align:start position:0% +so in that sense high standards have to + + + align:start position:0% +so in that sense high standards have to +be expected of the presentation and + + align:start position:0% +be expected of the presentation and + + + align:start position:0% +be expected of the presentation and +gathering of local knowledge not in + + align:start position:0% +gathering of local knowledge not in + + + align:start position:0% +gathering of local knowledge not in +terms of the use of very formal + + align:start position:0% +terms of the use of very formal + + + align:start position:0% +terms of the use of very formal +technical language by in terms of + + align:start position:0% +technical language by in terms of + + + align:start position:0% +technical language by in terms of +critical thinking and reasoning and only + + align:start position:0% +critical thinking and reasoning and only + + + align:start position:0% +critical thinking and reasoning and only +when these scientific standard these + + align:start position:0% +when these scientific standard these + + + align:start position:0% +when these scientific standard these +high standards I impose on our local + + align:start position:0% +high standards I impose on our local + + + align:start position:0% +high standards I impose on our local +knowledge will they be taken seriously + + align:start position:0% +knowledge will they be taken seriously + + + align:start position:0% +knowledge will they be taken seriously +by scientists and ultimately this entire + + align:start position:0% +by scientists and ultimately this entire + + + align:start position:0% +by scientists and ultimately this entire +process is as much a cultural process as + + align:start position:0% +process is as much a cultural process as + + + align:start position:0% +process is as much a cultural process as +it is a scientific process it's not just + + align:start position:0% +it is a scientific process it's not just + + + align:start position:0% +it is a scientific process it's not just +about the synthetic methods that we use + + align:start position:0% +about the synthetic methods that we use + + + align:start position:0% +about the synthetic methods that we use +but also in terms of leveraging the + + align:start position:0% +but also in terms of leveraging the + + + align:start position:0% +but also in terms of leveraging the +culture and social elements inherent in + + align:start position:0% +culture and social elements inherent in + + + align:start position:0% +culture and social elements inherent in +the community for example we might look + + align:start position:0% +the community for example we might look + + + align:start position:0% +the community for example we might look +at the social hierarchy in different + + align:start position:0% +at the social hierarchy in different + + + align:start position:0% +at the social hierarchy in different +regions and this babies actually from + + align:start position:0% +regions and this babies actually from + + + align:start position:0% +regions and this babies actually from +community to community as on town to + + align:start position:0% +community to community as on town to + + + align:start position:0% +community to community as on town to +town is there a central figure of trust + + align:start position:0% +town is there a central figure of trust + + + align:start position:0% +town is there a central figure of trust +that we can bring into the discussion + + align:start position:0% +that we can bring into the discussion + + + align:start position:0% +that we can bring into the discussion +do I have to launch your tea between + + align:start position:0% +do I have to launch your tea between + + + align:start position:0% +do I have to launch your tea between +both the locals and the scientists and + + align:start position:0% +both the locals and the scientists and + + + align:start position:0% +both the locals and the scientists and +are there certain social purposes that + + align:start position:0% +are there certain social purposes that + + + align:start position:0% +are there certain social purposes that +might need to be avoided or adhere to in + + align:start position:0% +might need to be avoided or adhere to in + + + align:start position:0% +might need to be avoided or adhere to in +terms of working or getting locals and + + align:start position:0% +terms of working or getting locals and + + + align:start position:0% +terms of working or getting locals and +sciences to work together so ultimately + + align:start position:0% +sciences to work together so ultimately + + + align:start position:0% +sciences to work together so ultimately +our agency's role is to avoid the events + + align:start position:0% +our agency's role is to avoid the events + + + align:start position:0% +our agency's role is to avoid the events +that happened in the 1960s and I believe + + align:start position:0% +that happened in the 1960s and I believe + + + align:start position:0% +that happened in the 1960s and I believe +that one way of doing that is to + + align:start position:0% +that one way of doing that is to + + + align:start position:0% +that one way of doing that is to +actually bring in local knowledge not as + + align:start position:0% +actually bring in local knowledge not as + + + align:start position:0% +actually bring in local knowledge not as +a form of opposition to what the + + align:start position:0% +a form of opposition to what the + + + align:start position:0% +a form of opposition to what the +scientists have been doing but as an + + align:start position:0% +scientists have been doing but as an + + + align:start position:0% +scientists have been doing but as an +enhancement to their work to enrich it + + align:start position:0% +enhancement to their work to enrich it + + + align:start position:0% +enhancement to their work to enrich it +and to ensure that whatever solution is + + align:start position:0% +and to ensure that whatever solution is + + + align:start position:0% +and to ensure that whatever solution is +worked out is in the best interest of + + align:start position:0% +worked out is in the best interest of + + + align:start position:0% +worked out is in the best interest of +both the community and the industry + + align:start position:0% + + + + align:start position:0% + +[Applause] \ No newline at end of file diff --git a/R250-aMpyAo.txt b/R250-aMpyAo.txt new file mode 100644 index 0000000000000000000000000000000000000000..0a35296df8d5c96d0301f224121aab24a4361ea3 --- /dev/null +++ b/R250-aMpyAo.txt @@ -0,0 +1,1259 @@ +align:start position:0% + +in the previous video we identified + + align:start position:0% +in the previous video we identified + + + align:start position:0% +in the previous video we identified +clusters or tissue substances and a + + align:start position:0% +clusters or tissue substances and a + + + align:start position:0% +clusters or tissue substances and a +healthy brain image it would be really + + align:start position:0% +healthy brain image it would be really + + + align:start position:0% +healthy brain image it would be really +helpful if we can use these clusters to + + align:start position:0% +helpful if we can use these clusters to + + + align:start position:0% +helpful if we can use these clusters to +automatically detect tumors in MRI + + align:start position:0% +automatically detect tumors in MRI + + + align:start position:0% +automatically detect tumors in MRI +images of sick patients the tumor that + + align:start position:0% +images of sick patients the tumor that + + + align:start position:0% +images of sick patients the tumor that +CSV file corresponds to an MRI brain + + align:start position:0% +CSV file corresponds to an MRI brain + + + align:start position:0% +CSV file corresponds to an MRI brain +image of a patient with + + align:start position:0% +image of a patient with + + + align:start position:0% +image of a patient with +oligodendroglioma a tumor that commonly + + align:start position:0% +oligodendroglioma a tumor that commonly + + + align:start position:0% +oligodendroglioma a tumor that commonly +occurs in the front lobe of the brain + + align:start position:0% +occurs in the front lobe of the brain + + + align:start position:0% +occurs in the front lobe of the brain +since brain biopsy is the only definite + + align:start position:0% +since brain biopsy is the only definite + + + align:start position:0% +since brain biopsy is the only definite +diagnosis of this tumor ever I guidance + + align:start position:0% +diagnosis of this tumor ever I guidance + + + align:start position:0% +diagnosis of this tumor ever I guidance +is key in determining its location and + + align:start position:0% +is key in determining its location and + + + align:start position:0% +is key in determining its location and +geometry now make sure that the tumor + + align:start position:0% +geometry now make sure that the tumor + + + align:start position:0% +geometry now make sure that the tumor +does CSV file is in your current + + align:start position:0% +does CSV file is in your current + + + align:start position:0% +does CSV file is in your current +directory let's go to the console and + + align:start position:0% +directory let's go to the console and + + + align:start position:0% +directory let's go to the console and +clear it and then read the data and save + + align:start position:0% +clear it and then read the data and save + + + align:start position:0% +clear it and then read the data and save +it to a data frame that we're going to + + align:start position:0% +it to a data frame that we're going to + + + align:start position:0% +it to a data frame that we're going to +call tumor who use the wreath of CSV + + align:start position:0% +call tumor who use the wreath of CSV + + + align:start position:0% +call tumor who use the wreath of CSV +function takes as an input the tumor + + align:start position:0% +function takes as an input the tumor + + + align:start position:0% +function takes as an input the tumor +they assess and make sure to turn off + + align:start position:0% +they assess and make sure to turn off + + + align:start position:0% +they assess and make sure to turn off +the header using header equals false and + + align:start position:0% +the header using header equals false and + + + align:start position:0% +the header using header equals false and +let's quickly create our tumor matrix + + align:start position:0% +let's quickly create our tumor matrix + + + align:start position:0% +let's quickly create our tumor matrix +using the S dot matrix function over the + + align:start position:0% +using the S dot matrix function over the + + + align:start position:0% +using the S dot matrix function over the +tumor data frame and the tumor vector + + align:start position:0% +tumor data frame and the tumor vector + + + align:start position:0% +tumor data frame and the tumor vector +using the esta vector function over the + + align:start position:0% +using the esta vector function over the + + + align:start position:0% +using the esta vector function over the +tumor matrix now we will not run the + + align:start position:0% +tumor matrix now we will not run the + + + align:start position:0% +tumor matrix now we will not run the +k-means algorithm again on the tumor + + align:start position:0% +k-means algorithm again on the tumor + + + align:start position:0% +k-means algorithm again on the tumor +vector instead we will apply the k-means + + align:start position:0% +vector instead we will apply the k-means + + + align:start position:0% +vector instead we will apply the k-means +clustering results that we found using + + align:start position:0% +clustering results that we found using + + + align:start position:0% +clustering results that we found using +the healthy brain image on the tumor + + align:start position:0% +the healthy brain image on the tumor + + + align:start position:0% +the healthy brain image on the tumor +vector in other words we treat the + + align:start position:0% +vector in other words we treat the + + + align:start position:0% +vector in other words we treat the +healthy vector as a training set and the + + align:start position:0% +healthy vector as a training set and the + + + align:start position:0% +healthy vector as a training set and the +tumor vector as a testing set to do this + + align:start position:0% +tumor vector as a testing set to do this + + + align:start position:0% +tumor vector as a testing set to do this +we first need to install a new package + + align:start position:0% +we first need to install a new package + + + align:start position:0% +we first need to install a new package +that is called flex blast so let us type + + align:start position:0% +that is called flex blast so let us type + + + align:start position:0% +that is called flex blast so let us type +installed our packages and then in + + align:start position:0% +installed our packages and then in + + + align:start position:0% +installed our packages and then in +between quotations flex cost and then + + align:start position:0% +between quotations flex cost and then + + + align:start position:0% +between quotations flex cost and then +the first thing our well ask us to unset + + align:start position:0% +the first thing our well ask us to unset + + + align:start position:0% +the first thing our well ask us to unset +the region that is closest to our + + align:start position:0% +the region that is closest to our + + + align:start position:0% +the region that is closest to our +geographical location and after that + + align:start position:0% +geographical location and after that + + + align:start position:0% +geographical location and after that +press ok and the installation shouldn't + + align:start position:0% +press ok and the installation shouldn't + + + align:start position:0% +press ok and the installation shouldn't +take more than two seconds to complete + + align:start position:0% +take more than two seconds to complete + + + align:start position:0% +take more than two seconds to complete +ok now that the package is installed let + + align:start position:0% +ok now that the package is installed let + + + align:start position:0% +ok now that the package is installed let +us load it by typing library and + + align:start position:0% +us load it by typing library and + + + align:start position:0% +us load it by typing library and +parentheses flex plus + + align:start position:0% + + + + align:start position:0% + +the flex plus package contains the + + align:start position:0% +the flex plus package contains the + + + align:start position:0% +the flex plus package contains the +object class KCC a which stands for + + align:start position:0% +object class KCC a which stands for + + + align:start position:0% +object class KCC a which stands for +carry centroids cluster analysis we need + + align:start position:0% +carry centroids cluster analysis we need + + + align:start position:0% +carry centroids cluster analysis we need +to convert the information from the + + align:start position:0% +to convert the information from the + + + align:start position:0% +to convert the information from the +clustering algorithm to an object of the + + align:start position:0% +clustering algorithm to an object of the + + + align:start position:0% +clustering algorithm to an object of the +class KCC a and this conversion is + + align:start position:0% +class KCC a and this conversion is + + + align:start position:0% +class KCC a and this conversion is +needed before we can use the predict + + align:start position:0% +needed before we can use the predict + + + align:start position:0% +needed before we can use the predict +function on the test set tumor vector so + + align:start position:0% +function on the test set tumor vector so + + + align:start position:0% +function on the test set tumor vector so +calling our new variable K and C dot G + + align:start position:0% +calling our new variable K and C dot G + + + align:start position:0% +calling our new variable K and C dot G +CCA and then using the S dot KCC a + + align:start position:0% +CCA and then using the S dot KCC a + + + align:start position:0% +CCA and then using the S dot KCC a +function which takes as a first input + + align:start position:0% +function which takes as a first input + + + align:start position:0% +function which takes as a first input +the original K and C variable that + + align:start position:0% +the original K and C variable that + + + align:start position:0% +the original K and C variable that +stored all the information from the + + align:start position:0% +stored all the information from the + + + align:start position:0% +stored all the information from the +k-means clustering function and the + + align:start position:0% +k-means clustering function and the + + + align:start position:0% +k-means clustering function and the +second input is the data that we + + align:start position:0% +second input is the data that we + + + align:start position:0% +second input is the data that we +clustered and in this case it's the + + align:start position:0% +clustered and in this case it's the + + + align:start position:0% +clustered and in this case it's the +training set which is the healthy vector + + align:start position:0% +training set which is the healthy vector + + + align:start position:0% +training set which is the healthy vector +and I'll be aware that this data + + align:start position:0% +and I'll be aware that this data + + + align:start position:0% +and I'll be aware that this data +conversion will take some time to run + + align:start position:0% +conversion will take some time to run + + + align:start position:0% +conversion will take some time to run +now that our finally finished creating + + align:start position:0% +now that our finally finished creating + + + align:start position:0% +now that our finally finished creating +the object k + c dot k CCA + + align:start position:0% +the object k + c dot k CCA + + + align:start position:0% +the object k + c dot k CCA +we can cluster the pixels of the tumor + + align:start position:0% +we can cluster the pixels of the tumor + + + align:start position:0% +we can cluster the pixels of the tumor +vector using the predict function let us + + align:start position:0% +vector using the predict function let us + + + align:start position:0% +vector using the predict function let us +call the cluster vector tumor clusters + + align:start position:0% +call the cluster vector tumor clusters + + + align:start position:0% +call the cluster vector tumor clusters +and that would be equal to predict and + + align:start position:0% +and that would be equal to predict and + + + align:start position:0% +and that would be equal to predict and +the first input is this new object can + + align:start position:0% +the first input is this new object can + + + align:start position:0% +the first input is this new object can +see that K CCA and the second input is + + align:start position:0% +see that K CCA and the second input is + + + align:start position:0% +see that K CCA and the second input is +the test data so let's type new data + + align:start position:0% +the test data so let's type new data + + + align:start position:0% +the test data so let's type new data +equals tumor vector and now the tumor + + align:start position:0% +equals tumor vector and now the tumor + + + align:start position:0% +equals tumor vector and now the tumor +clusters is a vector that assigns a + + align:start position:0% +clusters is a vector that assigns a + + + align:start position:0% +clusters is a vector that assigns a +value 1 through 5 to each of the + + align:start position:0% +value 1 through 5 to each of the + + + align:start position:0% +value 1 through 5 to each of the +intensity values in the tumor vector as + + align:start position:0% +intensity values in the tumor vector as + + + align:start position:0% +intensity values in the tumor vector as +predicted by the k-means algorithm to + + align:start position:0% +predicted by the k-means algorithm to + + + align:start position:0% +predicted by the k-means algorithm to +output the segmented image we first need + + align:start position:0% +output the segmented image we first need + + + align:start position:0% +output the segmented image we first need +to convert the tumor clusters to a + + align:start position:0% +to convert the tumor clusters to a + + + align:start position:0% +to convert the tumor clusters to a +matrix so let's use the dimension + + align:start position:0% +matrix so let's use the dimension + + + align:start position:0% +matrix so let's use the dimension +function and then the input is simply + + align:start position:0% +function and then the input is simply + + + align:start position:0% +function and then the input is simply +tumor clusters and then using the C + + align:start position:0% +tumor clusters and then using the C + + + align:start position:0% +tumor clusters and then using the C +function with the first input as the + + align:start position:0% +function with the first input as the + + + align:start position:0% +function with the first input as the +number of rows in the cuber matrix and + + align:start position:0% +number of rows in the cuber matrix and + + + align:start position:0% +number of rows in the cuber matrix and +the second input as the number of + + align:start position:0% +the second input as the number of + + + align:start position:0% +the second input as the number of +columns in the tumor matrix and now we + + align:start position:0% +columns in the tumor matrix and now we + + + align:start position:0% +columns in the tumor matrix and now we +can visualize the clusters by using the + + align:start position:0% +can visualize the clusters by using the + + + align:start position:0% +can visualize the clusters by using the +image function with the input tumor + + align:start position:0% +image function with the input tumor + + + align:start position:0% +image function with the input tumor +clusters matrix and make sure to set the + + align:start position:0% +clusters matrix and make sure to set the + + + align:start position:0% +clusters matrix and make sure to set the +axe + + align:start position:0% +axe + + + align:start position:0% +axe +system Falls and let's use again these + + align:start position:0% +system Falls and let's use again these + + + align:start position:0% +system Falls and let's use again these +fancy rainbow colors here so color is + + align:start position:0% +fancy rainbow colors here so color is + + + align:start position:0% +fancy rainbow colors here so color is +equal rainbow with the input K again K + + align:start position:0% +equal rainbow with the input K again K + + + align:start position:0% +equal rainbow with the input K again K +is equal to 5 all right let's navigate + + align:start position:0% +is equal to 5 all right let's navigate + + + align:start position:0% +is equal to 5 all right let's navigate +to the graphics window now to see if we + + align:start position:0% +to the graphics window now to see if we + + + align:start position:0% +to the graphics window now to see if we +can detect the tumor only yes we do it + + align:start position:0% +can detect the tumor only yes we do it + + + align:start position:0% +can detect the tumor only yes we do it +is this abnormal substance here that is + + align:start position:0% +is this abnormal substance here that is + + + align:start position:0% +is this abnormal substance here that is +highlighted in blue that was not present + + align:start position:0% +highlighted in blue that was not present + + + align:start position:0% +highlighted in blue that was not present +in the healthy MRI image so we were + + align:start position:0% +in the healthy MRI image so we were + + + align:start position:0% +in the healthy MRI image so we were +successfully able to identify more or + + align:start position:0% +successfully able to identify more or + + + align:start position:0% +successfully able to identify more or +less the geometry of the malignant + + align:start position:0% +less the geometry of the malignant + + + align:start position:0% +less the geometry of the malignant +structure we see that we did a good job + + align:start position:0% +structure we see that we did a good job + + + align:start position:0% +structure we see that we did a good job +capturing the major tissue substances of + + align:start position:0% +capturing the major tissue substances of + + + align:start position:0% +capturing the major tissue substances of +the brain the gray matter is highlighted + + align:start position:0% +the brain the gray matter is highlighted + + + align:start position:0% +the brain the gray matter is highlighted +in purple and the white matter in yellow + + align:start position:0% +in purple and the white matter in yellow + + + align:start position:0% +in purple and the white matter in yellow +for the sick patient the substance + + align:start position:0% +for the sick patient the substance + + + align:start position:0% +for the sick patient the substance +highlighted in blue is the only go down + + align:start position:0% +highlighted in blue is the only go down + + + align:start position:0% +highlighted in blue is the only go down +to human tumor notice that we do not see + + align:start position:0% +to human tumor notice that we do not see + + + align:start position:0% +to human tumor notice that we do not see +substantial blue regions and the healthy + + align:start position:0% +substantial blue regions and the healthy + + + align:start position:0% +substantial blue regions and the healthy +brain image apart from the region around + + align:start position:0% +brain image apart from the region around + + + align:start position:0% +brain image apart from the region around +the eyes actually looking at the eyes + + align:start position:0% +the eyes actually looking at the eyes + + + align:start position:0% +the eyes actually looking at the eyes +regions we notice that the tool images + + align:start position:0% +regions we notice that the tool images + + + align:start position:0% +regions we notice that the tool images +were not taken precisely at the same + + align:start position:0% +were not taken precisely at the same + + + align:start position:0% +were not taken precisely at the same +section of the brain this might explain + + align:start position:0% +section of the brain this might explain + + + align:start position:0% +section of the brain this might explain +some differences and shapes between the + + align:start position:0% +some differences and shapes between the + + + align:start position:0% +some differences and shapes between the +two images let's see how the images look + + align:start position:0% +two images let's see how the images look + + + align:start position:0% +two images let's see how the images look +like originally we see that the tumor + + align:start position:0% +like originally we see that the tumor + + + align:start position:0% +like originally we see that the tumor +region has a lighter color intensity + + align:start position:0% +region has a lighter color intensity + + + align:start position:0% +region has a lighter color intensity +which is very similar to the region + + align:start position:0% +which is very similar to the region + + + align:start position:0% +which is very similar to the region +around the eyes and the healthy brain + + align:start position:0% +around the eyes and the healthy brain + + + align:start position:0% +around the eyes and the healthy brain +image this might explain highlighting + + align:start position:0% +image this might explain highlighting + + + align:start position:0% +image this might explain highlighting +this region in blue of course we cannot + + align:start position:0% +this region in blue of course we cannot + + + align:start position:0% +this region in blue of course we cannot +claim that we did a wonderful job + + align:start position:0% +claim that we did a wonderful job + + + align:start position:0% +claim that we did a wonderful job +obtaining the exact geometries of all + + align:start position:0% +obtaining the exact geometries of all + + + align:start position:0% +obtaining the exact geometries of all +the tissue substances but we are + + align:start position:0% +the tissue substances but we are + + + align:start position:0% +the tissue substances but we are +definitely on the right track in fact to + + align:start position:0% +definitely on the right track in fact to + + + align:start position:0% +definitely on the right track in fact to +do so we need to use more advanced + + align:start position:0% +do so we need to use more advanced + + + align:start position:0% +do so we need to use more advanced +algorithms and fine-tune our clustering + + align:start position:0% +algorithms and fine-tune our clustering + + + align:start position:0% +algorithms and fine-tune our clustering +technique MRI image segmentation is an + + align:start position:0% +technique MRI image segmentation is an + + + align:start position:0% +technique MRI image segmentation is an +ongoing field of research while k-means + + align:start position:0% +ongoing field of research while k-means + + + align:start position:0% +ongoing field of research while k-means +clustering is a good starting point more + + align:start position:0% +clustering is a good starting point more + + + align:start position:0% +clustering is a good starting point more +advanced techniques have been proposed + + align:start position:0% +advanced techniques have been proposed + + + align:start position:0% +advanced techniques have been proposed +in the literature such as the modified + + align:start position:0% +in the literature such as the modified + + + align:start position:0% +in the literature such as the modified +fuzzy k-means clustering method also if + + align:start position:0% +fuzzy k-means clustering method also if + + + align:start position:0% +fuzzy k-means clustering method also if +you are interested or has packages that + + align:start position:0% +you are interested or has packages that + + + align:start position:0% +you are interested or has packages that +are specialized for analyzing reticle + + align:start position:0% +are specialized for analyzing reticle + + + align:start position:0% +are specialized for analyzing reticle +images now if we had MRI axial images + + align:start position:0% +images now if we had MRI axial images + + + align:start position:0% +images now if we had MRI axial images +taken at different sections of the brain + + align:start position:0% +taken at different sections of the brain + + + align:start position:0% +taken at different sections of the brain +we could segment each image and capture + + align:start position:0% +we could segment each image and capture + + + align:start position:0% +we could segment each image and capture +the geometries of + + align:start position:0% +the geometries of + + + align:start position:0% +the geometries of +substances at different levels then by + + align:start position:0% +substances at different levels then by + + + align:start position:0% +substances at different levels then by +interpolating between the segmented + + align:start position:0% +interpolating between the segmented + + + align:start position:0% +interpolating between the segmented +images we can estimate the missing sizes + + align:start position:0% +images we can estimate the missing sizes + + + align:start position:0% +images we can estimate the missing sizes +and we can then obtain a 3d + + align:start position:0% +and we can then obtain a 3d + + + align:start position:0% +and we can then obtain a 3d +reconstruction of the anatomy of the + + align:start position:0% +reconstruction of the anatomy of the + + + align:start position:0% +reconstruction of the anatomy of the +brain from 2d MRI cross-sections in fact + + align:start position:0% +brain from 2d MRI cross-sections in fact + + + align:start position:0% +brain from 2d MRI cross-sections in fact +3d reconstruction is particularly + + align:start position:0% +3d reconstruction is particularly + + + align:start position:0% +3d reconstruction is particularly +important in the medical field for + + align:start position:0% +important in the medical field for + + + align:start position:0% +important in the medical field for +diagnosis surgical planning and + + align:start position:0% +diagnosis surgical planning and + + + align:start position:0% +diagnosis surgical planning and +biological research purposes I hope that + + align:start position:0% +biological research purposes I hope that + + + align:start position:0% +biological research purposes I hope that +this recitation gave you a flavor of the + + align:start position:0% +this recitation gave you a flavor of the + + + align:start position:0% +this recitation gave you a flavor of the +Stassen ating field of image + + align:start position:0% +Stassen ating field of image + + + align:start position:0% +Stassen ating field of image +segmentation in our next video we will + + align:start position:0% +segmentation in our next video we will + + + align:start position:0% +segmentation in our next video we will +review all the UNIX tools we have + + align:start position:0% +review all the UNIX tools we have + + + align:start position:0% +review all the UNIX tools we have +covered so far in this class and discuss + + align:start position:0% +covered so far in this class and discuss + + + align:start position:0% +covered so far in this class and discuss +their uses pros and cons \ No newline at end of file diff --git a/RsOCnszziDA.txt b/RsOCnszziDA.txt new file mode 100644 index 0000000000000000000000000000000000000000..6a2c1353f7c2f2db0af4a368e9c48b74430def02 --- /dev/null +++ b/RsOCnszziDA.txt @@ -0,0 +1,555 @@ +align:start position:0% + +concept questions are a fairly recent um + + align:start position:0% +concept questions are a fairly recent um + + + align:start position:0% +concept questions are a fairly recent um +instrument for checking the + + align:start position:0% +instrument for checking the + + + align:start position:0% +instrument for checking the +understanding of students in real time + + align:start position:0% +understanding of students in real time + + + align:start position:0% +understanding of students in real time +during the class one way to administer + + align:start position:0% +during the class one way to administer + + + align:start position:0% +during the class one way to administer +concept questions is using clicker + + align:start position:0% +concept questions is using clicker + + + align:start position:0% +concept questions is using clicker +systems and they've been around for + + align:start position:0% +systems and they've been around for + + + align:start position:0% +systems and they've been around for +several years a concept question is + + align:start position:0% +several years a concept question is + + + align:start position:0% +several years a concept question is +typically a a very short question that + + align:start position:0% +typically a a very short question that + + + align:start position:0% +typically a a very short question that +requires either reflection or some very + + align:start position:0% +requires either reflection or some very + + + align:start position:0% +requires either reflection or some very +simple calculation that can be done in + + align:start position:0% +simple calculation that can be done in + + + align:start position:0% +simple calculation that can be done in +less than a + + align:start position:0% +less than a + + + align:start position:0% +less than a +minute the concept question is intended + + align:start position:0% +minute the concept question is intended + + + align:start position:0% +minute the concept question is intended +to surface misconceptions but also + + align:start position:0% +to surface misconceptions but also + + + align:start position:0% +to surface misconceptions but also +alignment and understanding + + align:start position:0% +alignment and understanding + + + align:start position:0% +alignment and understanding +and you know I do administer the concept + + align:start position:0% +and you know I do administer the concept + + + align:start position:0% +and you know I do administer the concept +questions using um in this case Google + + align:start position:0% +questions using um in this case Google + + + align:start position:0% +questions using um in this case Google +forms but you know there's other ways to + + align:start position:0% +forms but you know there's other ways to + + + align:start position:0% +forms but you know there's other ways to +do it essentially providing the students + + align:start position:0% +do it essentially providing the students + + + align:start position:0% +do it essentially providing the students +a very short URL a link that they can + + align:start position:0% +a very short URL a link that they can + + + align:start position:0% +a very short URL a link that they can +enter um either on their laptops even on + + align:start position:0% +enter um either on their laptops even on + + + align:start position:0% +enter um either on their laptops even on +their smartphones or on their tablets + + align:start position:0% +their smartphones or on their tablets + + + align:start position:0% +their smartphones or on their tablets +and usually a concept question is a + + align:start position:0% +and usually a concept question is a + + + align:start position:0% +and usually a concept question is a +multiple choice question sometimes it's + + align:start position:0% +multiple choice question sometimes it's + + + align:start position:0% +multiple choice question sometimes it's +very easy sometimes it's quite tricky + + align:start position:0% +very easy sometimes it's quite tricky + + + align:start position:0% +very easy sometimes it's quite tricky +and I give the students about 30 seconds + + align:start position:0% +and I give the students about 30 seconds + + + align:start position:0% +and I give the students about 30 seconds +or so to to think about it work out an + + align:start position:0% +or so to to think about it work out an + + + align:start position:0% +or so to to think about it work out an +answer respond online and then I display + + align:start position:0% +answer respond online and then I display + + + align:start position:0% +answer respond online and then I display +once uh once the answer period is over I + + align:start position:0% +once uh once the answer period is over I + + + align:start position:0% +once uh once the answer period is over I +display the responses in real time and + + align:start position:0% +display the responses in real time and + + + align:start position:0% +display the responses in real time and +what's nice about it is in the context + + align:start position:0% +what's nice about it is in the context + + + align:start position:0% +what's nice about it is in the context +of the Spock it doesn't matter where the + + align:start position:0% +of the Spock it doesn't matter where the + + + align:start position:0% +of the Spock it doesn't matter where the +students sit whether they're with you in + + align:start position:0% +students sit whether they're with you in + + + align:start position:0% +students sit whether they're with you in +the classroom whether they're online + + align:start position:0% +the classroom whether they're online + + + align:start position:0% +the classroom whether they're online +everybody has the same link so you're + + align:start position:0% +everybody has the same link so you're + + + align:start position:0% +everybody has the same link so you're +getting everybody's responses at the + + align:start position:0% +getting everybody's responses at the + + + align:start position:0% +getting everybody's responses at the +same time so it's a great mechanism for + + align:start position:0% +same time so it's a great mechanism for + + + align:start position:0% +same time so it's a great mechanism for +engagement sometimes everybody agrees + + align:start position:0% +engagement sometimes everybody agrees + + + align:start position:0% +engagement sometimes everybody agrees +100% or 90% agreement everybody chose + + align:start position:0% +100% or 90% agreement everybody chose + + + align:start position:0% +100% or 90% agreement everybody chose +the right answer and in that case + + align:start position:0% +the right answer and in that case + + + align:start position:0% +the right answer and in that case +there's not much discussion needed + + align:start position:0% +there's not much discussion needed + + + align:start position:0% +there's not much discussion needed +because it's clear that uh it clicked + + align:start position:0% +because it's clear that uh it clicked + + + align:start position:0% +because it's clear that uh it clicked +you know the concept is well understood + + align:start position:0% +you know the concept is well understood + + + align:start position:0% +you know the concept is well understood +my favorite concept questions are the + + align:start position:0% +my favorite concept questions are the + + + align:start position:0% +my favorite concept questions are the +one where the the answers are all over + + align:start position:0% +one where the the answers are all over + + + align:start position:0% +one where the the answers are all over +the map you know you have five possible + + align:start position:0% +the map you know you have five possible + + + align:start position:0% +the map you know you have five possible +choices and each of them got close to + + align:start position:0% +choices and each of them got close to + + + align:start position:0% +choices and each of them got close to +20% that's great because now you have a + + align:start position:0% +20% that's great because now you have a + + + align:start position:0% +20% that's great because now you have a +hook for + + align:start position:0% +hook for + + + align:start position:0% +hook for +discussion um so I would then if that + + align:start position:0% +discussion um so I would then if that + + + align:start position:0% +discussion um so I would then if that +happens I would spend the next three + + align:start position:0% +happens I would spend the next three + + + align:start position:0% +happens I would spend the next three +four five minutes in the class + + align:start position:0% +four five minutes in the class + + + align:start position:0% +four five minutes in the class +reiterating the concept and then asking + + align:start position:0% +reiterating the concept and then asking + + + align:start position:0% +reiterating the concept and then asking +students who voted for a who voted for B + + align:start position:0% +students who voted for a who voted for B + + + align:start position:0% +students who voted for a who voted for B +why did you do that what was your + + align:start position:0% +why did you do that what was your + + + align:start position:0% +why did you do that what was your +opinion um and so you get a great + + align:start position:0% +opinion um and so you get a great + + + align:start position:0% +opinion um and so you get a great +discussion going which again can have + + align:start position:0% +discussion going which again can have + + + align:start position:0% +discussion going which again can have +the in-classroom and then the online + + align:start position:0% +the in-classroom and then the online + + + align:start position:0% +the in-classroom and then the online +component as well we also use the chat + + align:start position:0% +component as well we also use the chat + + + align:start position:0% +component as well we also use the chat +during those uh post uh post concept + + align:start position:0% +during those uh post uh post concept + + + align:start position:0% +during those uh post uh post concept +questions and it's a great way to + + align:start position:0% +questions and it's a great way to + + + align:start position:0% +questions and it's a great way to +activate it and there's a second uh + + align:start position:0% +activate it and there's a second uh + + + align:start position:0% +activate it and there's a second uh +reason I also do concept questions at + + align:start position:0% +reason I also do concept questions at + + + align:start position:0% +reason I also do concept questions at +least one during lecture which is it's a + + align:start position:0% +least one during lecture which is it's a + + + align:start position:0% +least one during lecture which is it's a +great way to track + + align:start position:0% +great way to track + + + align:start position:0% +great way to track +attendance uh and I I'm upfront with the + + align:start position:0% +attendance uh and I I'm upfront with the + + + align:start position:0% +attendance uh and I I'm upfront with the +students about this because you can see + + align:start position:0% +students about this because you can see + + + align:start position:0% +students about this because you can see +the time tag when students responded so + + align:start position:0% +the time tag when students responded so + + + align:start position:0% +the time tag when students responded so +you know exactly who responded to the + + align:start position:0% +you know exactly who responded to the + + + align:start position:0% +you know exactly who responded to the +chat during the class and um I I do use + + align:start position:0% +chat during the class and um I I do use + + + align:start position:0% +chat during the class and um I I do use +that for um for participation grading \ No newline at end of file diff --git a/TkJ_WgruM2g.txt b/TkJ_WgruM2g.txt new file mode 100644 index 0000000000000000000000000000000000000000..17b421b6661d93e686c349dacbdb7bafbe2e244d --- /dev/null +++ b/TkJ_WgruM2g.txt @@ -0,0 +1,5041 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high-quality +educational resources for free. + +To make a donation or to +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: All right. + +So today's task is +going to be to outline + +some of the basic +experimental facts + +that we will both +have to deal with + +and that our aim should +be to understand and model + +through the rest of the course. + +Physics doesn't tell +you some abstract truth + +about why the universe +is the way it is. + +Physics gives you +models to understand + +how things work and predict +what will happen next. + +And what we will +be aiming to do is + +develop models that give us +an intuition for the phenomena + +and allow us to +make predictions. + +And these are going to be the +experimental facts I would like + +to both explain, develop +an intuition for, and be + +able to predict consequences of. + +So we'll start off with-- +so let me just outline them. + +So, first fact, atoms exist. + +I'll go over some of +the arguments for that. + +Randomness, definitely +present in the world. + +Atomic spectre are +discrete and structured. + +We have a photoelectric +effect, which + +I'll describe in some detail. + +Electrons do some funny things. + +In particular +electron diffraction. + +And sixth and finally, +Bell's Inequality. + +Something that we will come +back to at the very end + +of the class, which +I like to think + +of as a sort of a frame +for the entirety of 804. + +So everyone in here +knows that atoms + +are made of +electrons and nuclei. + +In particular, you +know that electrons + +exist because you've +seen a cathode ray tube. + +I used to be able to +say you've seen a TV, + +but you all have flat panel +TVs, so this is useless. + +So a cathode ray tube is a +gun that shoots electrons + +at a phosphorescent screen. + +And every time the +electron hits the screen + +it induces a little +phosphorescence, a little glow. + +And that's how you see on a CRT. + +And so as was pithily +stated long ago + +by a very famous physicist, if +you can spray them, they exist. + +Pretty good argument. + +There's a better argument for +the existence of electrons, + +which is that we can actually +see them individually. + +And this is one of +the most famous images + +in high-energy physics. + +It's from an experiment +called Gargamelle, + +which was a 30-cubic meter tank +of liquid freon pulsing just + +at its vapor pressure +60 times a second. + +And what this image is is, +apart from all the schmut, + +you're watching a +trail of bubbles + +in this de-pressurizing freon +that wants to create bubbles + +but you have to +nucleate bubbles. + +What you're seeing there +in that central line that + +goes up and then curls +around is a single electron + +that was nailed by a neutrino +incident from a beam at CERN + +where currently +the LHC is running. + +And this experiment +revealed two things. + +First, to us it +will reveal that you + +can see individual electrons and +by studying the images of them + +moving through +fluids and leaving + +a disturbing wake of +bubbles behind them. + +We can study their properties +in some considerable detail. + +The second thing it taught us +is something new-- we're not + +going to talk about +it in detail-- + +is that it's possible for a +neutrino to hit an electron. + +And that process is called +a weak neutral current + +for sort of stupid +historical reasons. + +It's actually a +really good name. + +And that was awesome +and surprising + +and so this picture +is both a monument + +to the technology +of the experiment, + +but also to the physics of weak +neutral currents and electrons. + +They exist if you can discover +neutrinos by watching them. + +OK. + +Secondly, nuclei. + +We know that nuclei +exist because you + +can shoot alpha particles, which +come from radioactive decay, + +at atoms. + +And you have your atom which +is some sort of vague thing, + +and I'm gonna make +the-- I'm gonna + +find the atom by making +a sheet of atoms. + +Maybe a foil. + +A very thin foil of stuff. + +And then I'm gonna shoot +very high-energy alpha + +particles incident of this. + +Probably everyone has +heard of this experiment, + +it was done by Rutherford +and Geiger and Marsden, + +in particular his students +at the time or post-docs. + +I don't recall-- and you shoot +these alpha particles in. + +And if you think of these guys +as some sort of jelly-ish lump + +then maybe they'll +deflect a little bit, + +but if you shoot a +bullet through Jello + +it just sort of maybe gets +deflected a little bit. + +But Jello, I mean, come on. + +And I think what was +shocking is that you should + +these alpha particles in +and every once in a while, + +they bounce back at, you +know, 180, 160 degrees. + +Rutherford likened this +to rolling a bowling + +ball against a piece of paper +and having it bounce back. + +Kind of surprising. + +And the explanation here that +people eventually came up upon + +is that atoms are +mostly zero density. + +Except they have very, +very high density + +cores, which are +many times smaller + +than the size of the atom +but where most of the mass + +is concentrated. + +And as a consequence, +most of the inertia. + +And so we know that +atoms have substructure, + +and the picture we have +is that well if you scrape + +this pile of metal, you can +pull off the electrons, leaving + +behind nuclei which have +positive charge because you've + +scraped off the electrons +that have negative charge. + +So we have a picture +from these experiments + +that there are +electrons and there + +are nuclei-- which, I'll +just write N and plus-- which + +are the constituents of atoms. + +Now this leads to a very natural +picture of what an atom is. + +If you're a 19th-century +physicist, or even + +an early 20th-century +physicist, it's very natural + +to say, aha, well if I know +if I have a positive charge + +and I have a +negative charge, then + +they attract each other with +a 1 over r minus q1 q2-- + +sorry, q1 q2 over r potential. + +This is just like +gravity, right. + +The earth and the +sun are attracted + +with an inverse-r potential. + +This leads to Keplerian orbits. + +And so maybe an atom +is just some sort + +of orbiting +classical combination + +of an electron and a nucleus, +positively charged nucleus. + +The problem with +this picture, as you + +explore in detail in your first +problem on the problem set, + +is that it doesn't work. + +What happens when you +accelerate a charge? + +It radiates. + +Exactly. + +So if it's radiating, +it's gotta lose energy. + +It's dumping energy into +this-- out of the system. + +So it's gotta fall lower +into the potential. + +Well it falls +lower, it speeds up. + +It radiates more. + +Because it's accelerating more +to stay in a circular orbit. + +All right, it radiates more, +it has to fall further down. + +So on the problem +set you're going + +to calculate how +long that takes. + +And it's not very long. + +And so the fact that we persist +for more than a few picoseconds + +tells you that it's +not that-- this is not + +a correct picture of an atom. + +OK. + +So in classical mechanics, +atoms could not exist. + +And yet, atoms exist. + +So we have to explain that. + +That's gonna be our +first challenge. + +Now interestingly Geiger +who is this collaborator + +of Rutherford, a young junior +collaborator of Rutherford, + +went on to develop a +really neat instrument. + +So suppose you want +to see radiation. + +We do this all the time. + +I'm looking at you and I'm +seeing radiation, seeing light. + +But I'm not seeing ultra +high energy radiation, + +I'm seeing energy radiation +in the electromagnetic waves + +in the optical spectrum. + +Meanwhile I'm also not +seeing alpha particles. + +So what Geiger wanted +was a way to detect + +without using your eyes +radiation that's hard to see. + +So the way he did this +is he took a capacitor + +and he filled the-- +surrounded the capacitor + +with some noble gas. + +It doesn't interact. + +There's no-- it's +very hard to ionize. + +And if you crank up the +potential across this capacitor + +plate high enough, +what do you get? + +A spark. + +You all know this, if you crank +up a capacitor it eventually + +breaks down because the +dielectric in between + +breaks down, you get a +spontaneous sparking. + +So what do you +figure it would look + +if I take a capacitor +plate and I charge it up, + +but not quite to breakdown. + +Just a good potential. + +And another charged particle +comes flying through, + +like an alpha particle, which +carries a charge of plus 2, + +that positive charge +will disturb things + +and will add extra +field effectively. + +And lead to the +nucleation of a spark. + +So the presence of a spark +when this potential is not + +strong enough to induce +a spark spontaneously + +indicates the passage +of a charged particle. + +Geiger worked later +with-- Marsden? + +Muller. + +Heck. + +I don't even remember. + +And developed this +into a device now known + +as the Geiger counter. + +And so you've probably all +seen or heard Geiger counters + +going off in movies, right. + +They go ping ping ping ping +ping ping ping ping ping, right. + +They bounce off randomly. + +This is an extremely +important lesson, + +which is tantamount to the +lesson of our second experiment + +yesterday. + +The 50-50, when we +didn't expect it. + +The white electrons +into the harness box + +then into a color box +again, would come out + +50-50, not 100 percent. + +And they come out in a +way that's unpredictable. + +We have no ability +to our knowledge-- + +and more than our +knowledge, we'll + +come back to that with +Bell's Inequality-- + +but we have no ability to +predict which electron will + +come out of that third +box, white or black, right. + +Similarly with a Geiger counter +you hear that atoms decay, + +but they decay randomly. + +The radiation comes out of a +pile of radioactive material + +totally at random. + +We know the probabilistic +description of that. + +We're going to develop that, +but we don't know exactly when. + +And that's a really +powerful example-- + +both of those experiments +are powerful examples + +of randomness. + +And so we're going to +have to incorporate that + +into our laws of physics into +our model of quantum phenomena + +as well. + +Questions? + +I usually have a Geiger +counter at this point, which + +is totally awesome, so I'll try +to produce the Geiger counter + +demo later. + +But the person with +the Geiger counter + +turns out to have +left the continent, + +so made it a little challenging. + +OK. + +Just sort of since we're at +MIT, an interesting side note. + +This strategy of +so-called hard scattering, + +of taking some +object and sending it + +at very high velocity +at some other object + +and looking for the rare +events when they bounce off + +at some large angle, +so-called hard scattering. + +Which is used to detect +dense cores of objects. + +It didn't stop with Rutherford. + +People didn't just +give up at that point. + +Similar experience +in the '60s and '70s + +which are conducted +at Slack, were + +involved not alpha +particles incident + +on atoms but individual +electrons incident on protons. + +So not shooting into the +nucleus, but shooting + +and looking for the effect +of hitting individual protons + +inside the nucleus. + +And through this process it +was discovered that in fact-- + +so this was done in the '60s and +'70s, that in fact the proton + +itself is also not a +fundamental particle. + +The proton is itself composite. + +And in particular, it's made +out of-- eventually people + +understood that it's made +out of, morally speaking, + +and I'm gonna put this +in quotation marks-- + +ask me about it +in office hours-- + +three quarks, which +are some particles. + +And the reason +we-- all this tells + +you is that it's some object and +we've given it the name quark. + +But indeed there are +three point-like particles + +that in some sense +make up a proton. + +It's actually much more +complicated than that, + +but these quarks, +among other things, + +have very strange properties. + +Like they have +fractional charge. + +And this was discovered by +a large group of people, + +in particular led by Kendall +and Friedman and also + +Richard Taylor. + +Kendall and Friedman +were at MIT, + +Richard Taylor was at Stanford. + +And in 1990 they +shared the Nobel Prize + +for the discovery of the +partonic structure out + +of the nucleons. + +So these sorts of +techniques that people + +have been using for +a very long time + +continue to be +useful and awesome. + +And in particular +the experiment, + +the experimental version of +this that's currently going on, + +that I particularly +love is something + +called the +relativistic heavy ion + +collider, which is +going on at Brookhaven. + +So here what you're doing is you +take two protons and you blow + +them into each other +at ultra high energy. + +Two protons, collide them +and see what happens. + +And that's what happens. + +You get massive shrapnel +coming flying out. + +So instead of having a simple +thing where one of the protons + +just bounces because there's +some hard quark, instead what + +happens is just shrapnel +everywhere, right. + +So you might think, well, how +do we interpret that at all. + +How do you make sense out of +14,000 particles coming out + +of two protons bouncing +into each other. + +How does that make any sense? + +And the answer turns out +to be kind of awesome. + +And so this touches +on my research. + +So I want to make a quick +comment on it just for color. + +The answer turns out to +be really interesting. + +First off, the interior +constituents of protons + +interact very strongly +with each other. + +But at the brief moment +when protons collide + +with each other, what +you actually form + +is not a point-like quirk +and another point-like quark. + +In fact, protons aren't made +out of point-like quarks at all. + +Protons are big bags +with quarks and gluons + +and all sorts of particles +fluctuating in and out + +of existence in a +complicated fashion. + +And what you actually get +is, amazingly, a liquid. + +For a brief, brief +moment of time + +the parts of those +protons that overlap-- + +think of them as +two spheres and they + +overlap in some sort of +almond-shaped region. + +The parts of those +protons that overlap + +form a liquid at +ultra high temperature + +and at ultra high density. + +It's called the RHIC fireball +or the quark-gluon plasma, + +although it's not +actually a plasma. + +But it's a liquid like water. + +And what I mean by saying +it's a liquid like water, + +if you push it, it +spreads in waves. + +And like water, +it's dissipative. + +Those waves dissipate. + +But it's a really +funny bit of liquid. + +Imagine you take +your cup of coffee. + +You drink it, you're drinking +your coffee as I am wont to do, + +and it cools down over time. + +This is very frustrating. + +So you pour in a little +bit of hot coffee + +and when you pour +in that hot coffee, + +the system is out +of equilibrium. + +It hasn't thermalized. + +So what you want is you want +to wait for all of the system + +to wait until it's come to +equilibrium so you don't + +get a swig of hot +or swig of cold. + +You want some sort of +Goldilocks-ean in between. + +So you can ask how long +does it take for this coffee + +to come to thermal equilibrium. + +Well it takes a while. + +You know, a few +seconds, a few minutes, + +depending on exactly +how you mess with it. + +But let me ask you +a quick question. + +How does that time scale +compare to the time + +it takes for light +to cross your mug? + +Much, much, much slower, right? + +By orders of magnitude. + +For this liquid that's formed +in the ultra high energy + +collision of two +protons, the time it + +takes for the system-- +which starts out + +crazy out of equilibrium +with all sorts of quarks + +here and gluons there +and stuff flying + +about-- the time it takes for it +to come to thermal equilibrium + +is of order the time +it takes for light + +to cross the little +puddle of liquid. + +This is a crazy liquid, it's +called a quantum liquid. + +And it has all sorts of +wonderful properties. + +And the best thing +about it to my mind + +is that it's very well +modeled by black holes. + +Which is totally separate +issue, but it's a fun example. + +So from these sorts +of collisions, + +we know a great deal +about the existence + +of atoms and randomness, +as you can see. + +That's a fairly random sorting. + +OK so moving on to +more 804 things. + +Back to atoms. + +So let's look at +specifics of that. + +I'm not kidding, they really +are related to black holes. + +I get paid for this. + +So here's a nice fact, so +let's get to atomic spectra. + +So to study atomic +spectra, here's + +the experiment I want to run. + +The experiment I want +to run starts out + +with some sort of power plant. + +And out of the power +plant come two wires. + +And I'm going to run these wires +across a spark gap, you know, + +a piece of metal here, +a piece of metal here, + +and put them inside a +container, which has some gas. + +Like H2 or neon or +whatever you want. + +But some simple gas inside here. + +So we've got an +electric potential + +established across it. + +Again, we don't want so much +potential that it sparks, + +but we do want to excite the H2. + +So we can even make it spark, it +doesn't really matter too much. + +The important +thing is that we're + +going to excite the hydrogen, +and in exciting the hydrogen + +the excited hydrogen is +going to send out light. + +And then I'm going to take +this light-- we take the light, + +and I'm gonna shine this +on a prism, something + +I was taught to do by Newton. + +And-- metaphorically +speaking-- and look + +at the image of +this light having + +passed through the prism. + +And what you find is you find a +very distinct set of patterns. + +You do not get a +continuous band. + +In fact what you get-- I'm going +to have a hard time drawing + +this so let me draw down here. + +I'm now going to draw the +intensity of the light incident + +on the screen on this piece +of paper-- people really used + +to use pieces of +paper for this, which + +is kind of awesome-- as a +function of the wavelength, + +and I'll measure +it in angstroms. + +And what you +discover is-- here's + +around 1,000 angstroms-- +you get a bunch of lines. + +Get these spikes. + +And they start to spread out, +and then there aren't so many. + +And then at around 3,000, +you get another set. + +And then at around 10,000, +you get another set. + +This is around 10,000. + +And here's the interesting +thing about these. + +So the discovery +of these lines-- + +these are named after a guy +named Lyman, these are-- these + +are named after a +guy named-- Ballmer. + +Thank you. + +Steve Ballmer. + +And these are passion, +like passion fruit. + +So. + +Everyone needs a mnemonic, OK. + +And so these people +identified these lines + +and explained various +things about them. + +But here's an interesting fact. + +If you replace this nuclear +power plant with a coal plant, + +it makes no difference. + +If you replace this prism +by a different prism, + +it makes no difference +to where the lines are. + +If you change this mechanism +of exciting the hydrogen, + +it makes no difference. + +As long as it's hydrogen-- as +long as it's hydrogen in here + +you get the same lines, mainly +with different intensities + +depending upon how exactly +you do the experiment. + +But you get the same +position of the lines. + +And that's a really +striking thing. + +Now if you use a different +chemical, a different gas + +in here, like neon, you get a +very different set of lines. + +And a very different +effective color + +now when you eyeball this thing. + +So Ballmer, +incidentally-- and I think + +this is actually +why he got blamed + +for that particular series, +although I don't know + +the history-- Ballmer noticed +by being-- depending on which + +biography you read-- very +clever or very obsessed + +that these guys, this particular +set, could be-- they're + +wavelengths. + +If you wrote their +wavelengths and labeled them + +by an integer n, +where n ran from 3 + +to any positive integer above +3, could be written as 36. + +So this is pure numerology. + +36, 46 angstroms times +the function n squared + +over n squared minus 4, +where N is equal to 3, 4, + +dot dot dot-- an integer. + +And it turns out if you +just plug in these integers, + +you get a pretty +good approximation + +to this series of lines. + +This is a hallowed +tradition, a phenomenological + +fit to some data. + +Where did it come from? + +It came from his creative +or obsessed mind. + +So this was Ballmer. + +And this is specifically +for hydrogen gas, H2. + +So Rydberg and Ritz, R and +R, said, well actually we + +can do one better. + +Now that they realized +that this is true, + +they looked at the +whole sequence. + +And they found a really +neat little expression, + +which is that 1 +over the wavelength + +is equal to a single +constant parameter. + +Not just for all these, +but for all of them. + +One single numerical coefficient +times 1 over m squared minus 1 + +over n squared-- n is an +integer greater than zero + +and greater in +particular than m. + +And if you plug in any value +of n and any value of m, + +for sufficiently +reasonable-- I mean, + +if you put in 10 +million integers + +you're not going to see it +because it's way out there, + +but if you put in +or-- rather, in here-- + +if you put any value +of n and m, you + +will get one of these lines. + +So again, why? + +You know, as it's +said, who ordered that. + +So this is experimental +result three + +that we're going to +have to deal with. + +When you look at atoms and you +look at the specter of light + +coming off of them, their +spectra are discrete. + +But they're not just +stupidly discrete, they're + +discrete with real structure. + +Something that begs +for an explanation. + +This is obviously +more than numerology, + +because it explains with +one tunable coefficient + +a tremendous number +of spectral lines. + +And there's a difference-- +and crucially, these both + +work specifically for hydrogen. + +For different atoms you need +a totally different formula. + +But again, there's +always some formula + +that nails those spectral lines. + +Why? + +Questions? + +OK. + +So speaking of atomic +spectra-- whoops, + +I went one too far-- here's +a different experiment. + +So people notice +the following thing. + +People notice that if +you take a piece of metal + +and you shine a light +at it, by taking the sun + +or better yet, you know, +these days we'd use a laser, + +but you shine light on +this piece of metal. + +Something that is done all the +time in condensed matter labs, + +it's a very useful technique. + +We really do use +lasers not the sun, + +but still it continues to be +useful in fact to this day. + +You shine light on a piece of +metal and every once in a while + +what happens is electrons +come flying off. + +And the more light and the +stronger the light you shine, + +you see changes in the way +that electrons bounce off. + +So we'd like to measure that. + +I'd like to make that precise. + +And this was done in a +really lovely experiment. + +Here's the experiment. + +The basic idea of the experiment +is I want to check to see, + +as I change the features of +the light, the intensity, + +the frequency, whatever, I +want to see how that changes + +the properties of the +electrons that bounce off. + +Now one obvious way-- +one obvious feature + +of an electron that flew +off a piece of metal + +is how fast is it going, how +much energy does it have. + +What's its kinetic energy. + +So I'd like to build +an experiment that + +measures the kinetic energy +of an electron that's + +been excited through this +photoelectric effect. + +Through emission after shining +light on a piece of metal. + +Cool? + +So I want to build +that experiment. + +So here's how that +experiment goes. + +Well if this electron +comes flying off + +with some kinetic +energy and I want + +to measure that kinetic energy, +imagine the following circuit. + +OK first off imagine I just +take a second piece of metal + +over here, and I'm going to put +a little current meter here, + +an ammeter. + +And here's what +this circuit does. + +When you shine light on +this piece of metal-- + +we'll put a screen to protect +the other piece of metal-- + +the electrons come flying +off, they get over here. + +And now I've got a bunch of +extra electrons over here + +and I'm missing +electrons over here. + +So this is negative, +this is positive. + +And the electrons will +not flow along this wire + +back here to +neutralize the system. + +The more light I shine, +the more electrons + +will go through this circuit. + +And as a consequence, there +will be a current running + +through this current meter. + +That cool with everyone? + +OK. + +So we haven't yet measured +the kinetic energy, though. + +How do we measure +the kinetic energy? + +I want to know how much +energy, with how much energy, + +were these electrons ejected. + +Well I can do that by the +following clever trick. + +I'm going to put now +a voltage source here, + +which I can tune the voltage +of, with the voltage V. + +And what that's going to do is +set up a potential difference + +across these and +the energy in that + +is the charge times the +potential difference. + +So I know that the potential +difference it takes, + +so the amount of energy +it takes to overcome + +this potential difference, +is q times V. That cool? + +So now imagine I send in an +electron-- I send in light + +and it leads an +electron to jump across, + +and it has kinetic energy, kE. + +Well if the kinetic +energy is less than this, + +will it get across? + +Not so much. + +It'll just fall back. + +But if the kinetic energy +is greater than the energy + +it takes to cross, it'll +cross and induce a current. + +So the upshot is that, as a +function of the voltage, what + +I should see is that there is +some critical minimum voltage. + +And depending on how +you set up the sign, + +the sign could be the +other way, but there's + +some critical minimal voltage +where, for less voltage, + +the electron doesn't get across. + +And for any greater +voltage-- or, sorry, + +for any closer to zero +voltage, the electron + +has enough kinetic +energy to get across. + +And so the current +should increase. + +So there's a critical +voltage, V-critical, + +where the current running +through the system + +runs to zero. + +You make it harder +for the electrons + +by making the voltage in +magnitude even larger. + +You make it harder for the +electrons to get across. + +None will get across. + +Make it a little easier, more +and more will get across. + +And the current will go up. + +So what you want to do to +measure this kinetic energy + +is you want to measure +the critical voltage + +at which the current +goes to zero. + +So now the question is +what do we expect to see. + +And remember that things we +can tune in this experiment + +are the intensity +of the light, which + +is like e squared +plus b squared. + +And we can tune the +frequency of the light. + +We can vary that. + +Now does the total energy, +does that frequency + +show up in the total energy of a +classical electromagnetic wave? + +No. + +If it's an electromagnetic +wave, it cancels out. + +You just get the +total intensity, + +which is a square of the fields. + +So this is just like +a harmonic oscillator. + +The energy is in the amplitude. + +The frequency of the +oscillator doesn't matter. + +You push the swing harder, +it gets more kinetic energy. + +It's got more energy. + +OK. + +So what do we expect +to see as we vary, + +for example, the intensity? + +So here's a natural gas. + +If you take-- so you can +think about the light here + +as getting a person literally, +like get the person next to you + +to take a bat and +hit a piece of metal. + +If they hit it really +lightly they're + +probably not going to excite +electrons with a lot of energy. + +If they just whack +the heck out of it, + +then it wouldn't +be too surprising + +if you get much more energy +in the particles that + +come flying off. + +Hit it hard enough, +things are just + +gonna shrapnel and disintegrate. + +The expectation here +is the following. + +That if you have a +more intense beam, + +then you should get more-- +the electrons coming off + +should be more energetic. + +Because you're +hitting them harder. + +And remember that +the potential, which + +I will call V0, the +stopping voltage. + +So therefore V0 should +be greater in magnitude. + +So this anticipates +that the way this curve + +should look as we vary the +current as a function of v, + +if we have a low voltage-- +sorry, if we have + +a low-intensity beam-- it +shouldn't take too much + +potential just to +impede the motion. + +But if we have a-- so +this is a low intensity. + +But if we have a +high-intensity beam, + +it should take a +really large voltage + +to impede the electric +flow, the electric current, + +because high-intensity +beam you're just + +whacking those +electrons really hard + +and they're coming off with +a lot of kinetic energy. + +So this is high intensity. + +Everyone down with +that intuition? + +This is what you get from +Maxwell's electrodynamics. + +This is what you'd expect. + +And in particular, +as we vary-- so + +this is our predictions-- +in particular + +as we vary-- so this is 1, +2, with greater intensity. + +And the second prediction +is that V-naught + +should be independent +of frequency. + +Because the energy density +and electromagnetic wave + +is independent of the frequency. + +It just depends +on the amplitude. + +And I will use nu to +denote the frequency. + +So those are the predictions +that come from 802 and 803. + +But this is 804. + +And here's what the experimental +results actually look like. + +So here's the intensity, +here's the potential. + +And if we look at +high potential, + +it turns out that-- +if we look, sorry, + +if we look at +intermediate potentials, + +it's true that the high +intensity leads to a larger + +current and the low intensity +leads to a lower current. + +But here's the funny +thing that happens. + +As you go down to +the critical voltage, + +their critical +voltages are the same. + +What that tells you is that +the kinetic energy kicked out-- + +or the kinetic +energy of an electron + +kicked out of this piece +of metal by the light + +is independent of how +intense that beam is. + +No matter how intense +that beam is, no matter + +how strong the light you +shine on the material, + +the electrons all come +out with the same energy. + +This would be like +taking a baseball + +and hitting it with a really +powerful swing or a really + +weak swing and seeing that +the electron dribbles away + +with the same amount of energy. + +This is very counter-intuitive. + +But more surprisingly, +V-naught is actually + +independent of intensity. + +But here's the real shocker. + +V-naught varies linearly +in the frequency. + +What does change V-naught +is changing the frequency + +of the light in this incident. + +That means that if you take +an incredibly diffuse light-- + +incredibly diffuse light, +you can barely see it-- + +of a very high frequency, +then it takes a lot of energy + +to impede the electrons +that come popping off. + +The electrons that come popping +off have a large energy. + +But if you take a low-frequency +light with extremely high + +intensity, then those electrons +are really easy to stop. + +Powerful beam but +low frequency, it's + +easy to stop those electrons. + +Weak little tiny beam +at high frequency, + +very hard to stop the +electrons that do come off. + +So this is very +counter-intuitive + +and it doesn't fit at all +with the Maxwellian picture. + +Questions about that? + +So this led Einstein +to make a prediction. + +This was his 1905 result. + +One of his many totally +breathtaking papers + +of that year. + +And he didn't really +propose a model + +or a detailed theoretical +understanding of this, + +but he proposed a +very simple idea. + +And he said, look, if +you want to fit this-- + +if you want to fit +this experiment + +with some simple equations, +here's the way to explain it. + +I claim-- I here means +Einstein, not me-- + +I claim that light comes +in packets or chunks + +with definite energy. + +And the energy is linearly +proportional to the frequency. + +And our energy is equal +to something times nu, + +and we'll call +the coefficient h. + +The intensity of +light, or the amplitude + +squared, the intensity is +like the number of packets. + +So if you have a more intense +beam at the same frequency, + +the energy of each individual +chunk of light is the same. + +There are just a lot more +chunks flying around. + +And so to explain the +photoelectric effect, + +Einstein observed the following. + +Look, he said, the electrons +are stuck under the metal. + +And it takes some +work to pull them off. + +So now what's the kinetic +energy of an electron that + +comes flying off-- whoops, k3. + +Bart might have a +laugh about that one. + +Kinetic, kE, not 3. + +So the kinetic energy of +electron that comes flying off, + +well, it's the energy +deposited by the photon, + +the chunk of light, +h-nu well we have + +to subtract off +the work it took. + +Minus the work to extract the +electron from the material. + +And you can think of +this as how much energy + +does it take to suck +it off the surface. + +And the consequence of this +is that the kinetic energy + +of an electron should be-- +look, if h-nu is too small, + +if the frequency +is too low, then + +the kinetic energy +would be negative. + +But that doesn't make any sense. + +You can't have negative +kinetic energy. + +It's a strictly +positive quantity. + +So it just doesn't work until +you have a critical value where + +the frequency times h-- +this coefficient-- is + +equal to the work +it takes to extract. + +And after that, +the kinetic energy + +rises with the frequency +with a slope equal to h. + +And that fits the +data like a chain. + +So no matter-- let's think +about what this is saying again. + +No matter what you do, if your +light is very low-frequency + +and you pick some definite +piece of metal that + +has a very definite +work function, very + +definite amount +of energy it takes + +to extract electrons +from the surface. + +No matter how intense your +beam, if the frequency is + +insufficiently high, +no electrons come off. + +None. + +So it turns out none is +maybe a little overstatement + +because what you can have is +two photon processes, where + +two chunks hit one +electron at the right, just + +at the same time. + +Roughly speaking the same time. + +And they have twice +the energy, but you + +can imagine that the +probability of two + +photon hitting one electron at +the same time of pretty low. + +So the intensity has to +be preposterously high. + +And you see those sorts +of multi-photon effects. + +But as long as we're not +talking about insanely + +high intensities, this is an +absolutely fantastic probe + +of the physics. + +Now there's a whole +long subsequent story + +in the development +of quantum mechanics + +about this particular effect. + +And it turns out that +the photoelectric effect + +is a little more +complicated than this. + +But the story line +is a very useful one + +for organizing +your understanding + +of the photoelectric effect. + +And in particular, this relation +that Einstein proposed out + +of the blue, with +no other basis. + +No one else had ever seen +this sort of statement + +that the electrons, or that +the energy of a beam of light + +should be made up of some +number of chunks, each of which + +has a definite minimum +amount of energy. + +So you can take what you've +learned from 802 and 803 + +and extract a little bit +more information out of this. + +So here's something +you learned from 802. + +In 802 you learned +that the energy + +of an electromagnetic +wave is equal to c + +times the momentum carried by +that wave-- whoops, over two. + +And in 803 you +should have learned + +that the wavelength of +an electromagnetic wave + +times the frequency is equal +to the speed of light, C. + +And we just had Einstein +tell us-- or declare, + +without further evidence, +just saying, look this fits-- + +that the energy of +a chunk of light + +should be h times the frequency. + +So if you combine +these together, + +you get another +nice relation that's + +similar to this one, which says +that the momentum of a chunk + +of light is equal +to h over lambda. + +So these are two enormously +influential expressions + +which come out of this argument +from the photoelectric effect + +from Einstein. + +And they're going +to be-- their legacy + +will be with us throughout +the rest of the semester. + +Now this coefficient has a name, +and it was named after Planck. + +It's called Planck's Constant. + +And the reason that it's +called Planck's Constant + +has nothing to do with +the photoelectric effect. + +It was first this idea that +an electromagnetic wave, + +that light, has an energy +which is linearly proportional + +not to its intensity +squared, none of that, + +but just linearly +proportional to the frequency. + +First came up an analysis of +black body radiation by Planck. + +And you'll understand, +you'll go through this + +in some detail in 804 +later in the semester. + +So I'm not going +to dwell on it now, + +but I do want to give you +a little bit of perspective + +on it. + +So Planck ran across this +idea that E is equal to h/nu. + +Through the process of trying +to fit an experimental curve. + +There was a theory +of how much energy + +should be emitted +by an object that's + +hot and glowing as a +function of frequency. + +And that theory turned out +to be in total disagreement + +with experiment. + +Spectacular disagreement. + +The curve for the +theory went up, + +the curve for the +experiment went down. + +They were totally different. + +So Planck set about writing +down a function that + +described the data. + +Literally curve-fitting, +that's all he was doing. + +And this is the +depths of desperation + +to which he was led, +was curve-fitting. + +He's an adult. + +He shouldn't be doing this, +but he was curve-fitting. + +And so he fits the +curve, and in order + +to get it to fit the only thing +that he can get to work even + +vaguely well is if he puts +in this calculation of h/nu. + +He says, well, maybe when I sum +over all the possible energies + +I should restrict +the energies which + +were proportional +to the frequency. + +And it was forced on him because +it fit from the function. + +Just functional analysis. + +Hated it. + +Hated it, he +completely hated it. + +He was really +frustrated by this. + +It fit perfectly, he +became very famous. + +He was already famous, but he +became ridiculously famous. + +Just totally loathed this idea. + +OK. + +So it's now become a cornerstone +of quantum mechanics. + +But he wasn't so happy about it. + +And to give you a +sense for how bold + +and punchy this paper by +Einstein was that said, + +look, seriously. + +Seriously guys. e equals h/nu. + +Here's what Planck +had to say when + +he wrote a letter +of recommendation + +to get Einstein into the +Prussian Academy of Sciences + +in 1917, or 1913. + +So he said, there is hardly +one among the great problems + +in physics to which +Einstein has not + +made an important contribution. + +That he may sometimes have +missed the target in his + +speculations as in his +hypothesis of photons cannot + +really be held too +much against him. + +It's not possible to introduce +new ideas without occasionally + +taking a risk. + +Einstein who +subsequently went on + +to develop special relativity +and general relativity + +and prove the existence +of atoms and the best + +measurement of Avogadro's +Constant, subsequently + +got the Nobel Prize. + +Not for Avogadro's Constant, +not for proving the existence + +of atoms, not for +relativity, but for photons. + +Because of guys +like Planck, right. + +This is crazy. + +So this was a pretty bold idea. + +And here, to get +a sense for why-- + +we're gonna leave that up +because it's just sort of fun + +to see these guys scowling +and smiling-- there + +is, incidentally there's a great +book about Einstein's years + +in Berlin by Tom Levenson, +who's a professor here. + +A great writer and a sort +of historian of science. + +You should take a class from +him, which is really great. + +But I encourage you +to read this book. + +It talks about why Planck is not +looking so pleased right there, + +among many other things. + +It's a great story. + +So let's step back for a second. + +Why was Planck so upset by this, +and why was in fact everyone + +so flustered by this idea +that it led to the best prize + +you can give a physicist. + +Apart from a happy +home and, you know. + +I've got that one. + +That's the one +that matters to me. + +So why is this so surprising? + +And the answer is really simple. + +We know that it's false. + +We know empirically, we've known +for two hundred and some years + +that light is a wave. + +Empirically. + +This isn't like +people are like, oh I + +think it'd be nice +if it was a wave. + +It's a wave. + +So how do we know that? + +So this goes back to the +double-slit experiment + +from Young. + +Young's performance +of this was in 1803. + +Intimations of it +come much earlier. + +But this is really where +it hits nails to the wall. + +And here's the experiment. + +So how many people +in here have not + +seen a double-slit +experiment described? + +Yeah, exactly. + +OK. + +So I'm just going to quickly +remind you of how this goes. + +So we have a source for waves. + +We let the waves get big until +they're basically plane waves. + +And then we take a barrier. + +And we poke two slits in it. + +And these plane +waves induce-- they + +act like sources at the +slits and we get nu. + +And you get crests and troughs. + +And you look at +some distant screen + +and you look at the pattern, +and the pattern you get + +has a maximum. + +But then it falls off, +and it has these wiggles, + +these interference fringes. + +These interference fringes are, +of course, extremely important. + +And what's going on here is that +the waves sometimes add in-- + +so the amplitude of the +wave, the height of the wave, + +sometimes adds constructively +and sometimes destructively. + +So that sometimes you +get twice the height + +and sometimes you get nothing. + +So just because it's +fun to see this, + +here's Young's actual diagram +from his original note + +on the double-slit experiment. + +So a and b are the slits, and +c, d and f are the [INAUDIBLE] + +on the screen, the +distant screen. + +He drew it by hand. + +It's pretty good. + +So we've known for a very +long time that light, because + +of the double-slit experiment, +light is clearly wavy, + +it behaves like a wave. + +And what are the senses in +which it behaves like a wave? + +There are two +important senses here. + +The first is answered +by the question, + +where did the wave +hit the screen? + +So when we send in a wave, +you know, I drop a stone, + +one big pulsive wave comes out. + +It splits into-- it leads to +new waves being instigated here + +and over here. + +Where did that wave +hit the screen? + +Anyone? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, exactly. + +It didn't hit this wave-- +the screen in any one spot. + +But some amplitude +shows up everywhere. + +The wave is a +distributed object, + +it does not exist at one spot, +and it's by virtue of the fact + +that it is not a localized +object-- it is not + +a point-like object-- that +it can interfere with itself. + +The wave is a big large +phenomena in a liquid, + +in some thing. + +So it's sort of essential that +it's not a localized object. + +So not localized. + +The answer is not localized. + +And let's contrast +this with what + +happens if you take this +double-slit experiment + +and you do it with, you know, +I don't know, take-- who. + +Hmm. + +Tim Wakefield. + +Let's give some +love to that guy. + +So, baseball player. + +And have him throw baseballs at +a screen with two slits in it. + +OK? + +Now he's got pretty good-- well, +he's got terrible accuracy, + +actually. + +So every once in a while he'll +make it through the slits. + +So let's imagine +first blocking off-- + +what, he's a knuckle-baller, +right-- so every + +once in a while it +goes, the baseball + +will go through the slit. + +And let's think +about what happens, + +so let's cover one slit. + +And what we expect to +happen is, well, it'll + +go through more +or less straight, + +but sometimes it'll scrape the +edge, it'll go off to the side, + +and sometimes it'll +come over here. + +But if you take a whole +bunch of baseballs, + +and-- so any one baseball, +where does it hit? + +Some spot. + +Right? + +One spot. + +Not distributed. + +One spot. + +And as a consequence, you know, +one goes here, one goes there, + +one goes there. + +And now, there's nothing +like interference effects, + +but what happens is as it +sort of doesn't-- you get some + +distribution if you look +at where they all hit. + +Yeah? + +Everyone cool with that? + +And if we had covered +over this slot, or slit, + +and let the baseballs +go through this one, + +same thing would have happened. + +Now if we leave +them both open, what + +happens is sometimes it goes +here, sometimes it goes here. + +So now it's pretty useful that +we've got a knuckle-baller. + +And what you actually get +is the total distribution + +looks like this. + +It's the sum of the two. + +But at any given time, +any one baseball, + +you say, aha, the +baseball either went + +through the top slit, and +more or less goes up here. + +Or it went through +the bottom slit + +and more or less goes down here. + +So for chunks-- so this is for +waves-- for chunks or localized + +particles, they are localized. + +And as a consequence, +we get no interference. + +So for waves, they +are not localized, + +and we do get interference. + +Yes, interference. + +OK. + +So on your problem +set, you're going + +to deal with some calculations +involving these interference + +effects. + +And I'm going to +brush over them. + +Anyway the point of the +double-slit experiment + +is that whatever else you +want to say about baseballs + +or anything else, +light, as we've + +learned since 1803 in Young's +double-slit experiment, + +light behaves like a wave. + +It is not localized, it hits the +screen over its entire extent. + +And as a consequence, +we get interference. + +The amplitudes add. + +The intensity is the +square of the amplitude. + +If the intensities +add-- so sorry, + +if the amplitudes add-- +amplitude total is + +equal to a1 plus +a2, the intensity, + +which is the square +of a1 plus a2 squared, + +has interference terms, the +cross terms, from this square. + +So light, from +this point of view, + +is an electromagnetic wave. + +It interferes with itself. + +It's made of chunks. + +And I can't help but +think about it this way, + +this is literally the metaphor +I use in my head-- light is + +creamy and smooth like a wave. + +Chunks are very different. + +But here's the funny thing. + +Light is both smooth like +a wave, it is also chunky. + +It is super chunky, +as we have learned + +from the photoelectric effect. + +So light is both at once. + +So it's the best of both worlds. + +Everyone will be satisfied, +unless you're not + +from the US, in which case +this is deeply disturbing. + +So of course the original +Superchunk is a band. + +So we've learned now from +Young that light is a wave. + +We've learned from the +photoelectric effect + +that light is a bunch of chunks. + +OK. + +Most experimental +results are true. + +So how does that work? + +Well, we're gonna have +to deal with that. + +But enough about light. + +If this is true of +light, if light, + +depending on what +experiment you do + +and how you do the +experiment, sometimes it + +seems like it's +a wave, sometimes + +it seems like it's a chunk +or particle, which is true? + +Which is the better description? + +So it's actually +worthwhile to not think + +about light all the time. + +Let's think about +something more general. + +Let's stick to electrons. + +So as we saw from +yesterday's lecture, + +you probably want to +be a little bit wary + +when thinking about +individual electrons. + +Things could be a +little bit different + +than your classical intuition. + +But here's a crucial thing. + +Before doing anything +else, we can just think, + +which one of these two is more +likely to describe electrons + +well. + +Well electrons are localized. + +When you throw an +electron at a CRT, + +it does not hit the whole +CRT with a wavy distribution. + +When you take a single electron +and you throw it at a CRT, + +it goes ping and there's +a little glowing spot. + +Electrons are localized. + +And we know that +localized things + +don't lead to interference. + +Some guys at Hitachi, really +good scientists and engineers, + +developed some really awesome +technology a couple of decades + +ago. + +They were trying to +figure out a good way + +to demonstrate their technology. + +And they decided that you know +what would be really awesome, + +this thought experiment +that people have always + +talked about that's never +been done really well, + +of sending an electron through +a two-slitted experiment. + +In this case it was like +ten slits effectively, + +it was a grading. + +Send an electron, a bunch +of electrons, one at a time, + +throw the electron, wait. + +Throw the electron, wait. + +Like our French +guy with the boat. + +So do this experiment +with our technology + +and let's see what happens. + +And this really is +one of my favorite-- + +let's see, how we close +these screens-- aha. + +OK. + +This is going to take a little +bit of-- and it's broken. + +No, no. + +Oh that's so sad. + +AUDIENCE: [LAUGHTER] + +PROFESSOR: Come on. + +I'm just gonna let-- +let's see if we can, + +we'll get part of the way. + +I don't want to destroy it. + +So what they actually +did is they said, look, + +let's-- we want to +see what happens. + +We want to actually do this +experiment because we're + +so awesome at Hitachi +Research Labs, so let's do it. + +So here's what they did. + +And I'm going to +turn off the light. + +And I set this to some +music because I like it. + +OK here's what's happening. + +One at a time, +individual photons. + +[MUSIC PLAYING] + +PROFESSOR: So they +look pretty localized. + +There's not a whole +lot of structure. + +Now they're going to +start speeding it up. + +It's 100 times the actual speed. + +[MUSIC PLAYING] + +PROFESSOR: Eh? + +Yeah. + +AUDIENCE: [APPLAUSE] + +PROFESSOR: So those guys +know what they're doing. + +Let's-- there were go. + +So I think I don't know of a +more vivid example of electron + +interference than that one. + +It's totally obvious. + +You see individual electrons. + +They run through the apparatus. + +You wait, they run +through the apparatus. + +You wait. + +One at a time, single +electron, like a baseball + +being pitched through two +slits, and what you see + +is an interference effect. + +But you don't see the +interference effect + +like you do from light, +from waves on the sea. + +You see the interference +effect by looking + +at the cumulative stacking up of +all the electrons as they hit. + +Look at where all the +electrons hit one at a time. + +So is an electron behaving +like a wave in a pond? + +No. + +Does a wave in a pond at a spot? + +No. + +It's a distributed beast. + +OK yes, it interferes, +but it's not localized. + +Well is it behaving +like a baseball? + +Well it's localized. + +But on-- when I look at a +whole bunch of electrons, + +they do that. + +They seem to interfere, but +there's only one electron + +going through at a time. + +So in some sense it's +interfering with itself. + +How does that work? + +Is an electron a wave? + +AUDIENCE: Yes. + +PROFESSOR: Does an electron +hit at many spots at once? + +AUDIENCE: No. + +PROFESSOR: No. + +So is an electron a wave. + +No. + +Is an electron a baseball? + +No. + +It's an electron. + +So this is something +you're going + +to have to deal with, that +every once in awhile we + +have these wonderful +moments where it's + +useful to think +about an electron + +as behaving in a +wave-like sense. + +Sometimes it's useful +to think about it + +as behaving in a +particle-like sense. + +But it is not a particle +like you normally + +conceive of a baseball. + +And it is not a wave +like you normally + +conceive of a wave on +the surface of a pond. + +It's an electron. + +I like to think about +this like an elephant. + +If you're closing your eyes +and you walk up to an elephant, + +you might think like I've got a +snake and I've got a tree trunk + +and, you know, there's +a fan over here. + +And you wouldn't know, +like, maybe it's a wave, + +maybe it's a particle, +I can't really tell. + +But if you could just +see the thing the way + +it is, not through the +preconceived sort of notions + +you have, you'd see +it's an elephant. + +Yes, that is the Stata Center. + +So-- look, everything has +to happen sometime, right? + +AUDIENCE: [LAUGHTER] + +PROFESSOR: So +Heisenberg-- it's often, + +people often give the false +impression in popular books + +on physics, so I +want to subvert this, + +that in the early days +of quantum mechanics, + +the early people like +Born and Oppenheimer + +and Heisenberg who +invented quantum mechanics, + +they were really tortured about, +you know, is it an electron, + +is it a wave. + +It's a wave-particle duality. + +It's both. + +And this is one of +the best subversions + +of that sort of +silliness that I know of. + +And so what Heisenberg says, +the two mental pictures + +which experiments lead us to +form, the one of particles + +the other waves, +are both incomplete + +and have the validity +of analogies, + +which are accurate +only in limited cases. + +The apparent duality rises in +the limitation of our language. + +And then he goes +on to say, look, + +you developed your intuition by +throwing rocks and, you know, + +swimming. + +And, duh, that's not going +to be very good for atoms. + +So this will be posted, +it's really wonderful. + +His whole lecture is +really-- the lectures + +are really quite lovely. + +And by the way, that's +him in the middle there, + +Pauley all the way on the right. + +I guess they were pleased. + +OK so that's the Hitachi thing. + +So now let's pick +up on this, though. + +Let's pick up on this and +think about what happens. + +I want to think in a little +more detail about this Hitachi + +experiment. + +And I want to think +about it in the context + +of a simple two-slit experiment. + +So here's our +source of electrons. + +It's literally a +gun, an electron gun. + +And it's firing off electrons. + +And here's our barrier, +and it has two slits in it. + +And we know that any individual +electron hits its own spot. + +But when we take many of them, +we get an interference effect. + +We get interference fringes. + +And so the number +that hit a given spot + +fill up, construct +this distribution. + +So then here's the +question I want to ask. + +When I take a single electron, +I shoot one electron at a time + +through this experiment, +one electron. + +It could go through +the top slit, + +it could go through +the bottom slit. + +While it's inside the apparatus, +which path does it take? + +AUDIENCE: [INAUDIBLE] position. + +PROFESSOR: Good. + +So did it take the top path? + +AUDIENCE: No. + +PROFESSOR: How do you know? + +[INTERPOSING VOICES] + +PROFESSOR: Good, let's +block the bottom, OK, + +to force it to go +through the top slit. + +So we'll block the bottom slit. + +Now the only +electrons that make it + +through go through the top slit. + +Half of them don't +make it through. + +But those that do +make it through + +give you this distribution. + +No interference. + +But I didn't tell you these +are hundreds of thousands + +of kilometers apart, +the person who + +threw in the +electron didn't know + +whether there was +a barrier here. + +The electron, how +could it possibly + +know whether there +was a barrier here + +if you went through the top. + +This is exactly like our boxes. + +It's exactly like our box. + +Did it go through-- an electron, +when the slits are both open + +and we know that ensemble +average it will give us + +an interference effect, did the +electron inside the apparatus + +go through the top path? + +No. + +Did it go through +the bottom path? + +Did it go through both? + +Because we only +see one electron. + +Did it go through neither? + +It is in a-- + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: --of having gone +through the top and the bottom. + +Of being along the top half and +being along the bottom path. + +This is a classic example +of the two-box experiment. + +OK. + +So you want to +tie that together. + +So let's nuance +this just a little + +bit, though, because +it's going to have + +an interesting +implication for gravity. + +So here's the nuance I +want to pull on this one. + +Let's cheat. + +OK. + +Suppose I want to measure which +slit the electron actually + +did go through. + +How might I do that? + +Well I could do the +course thing I've + +been doing which is I could +block it and just catch + +the-- catch electrons that +go through in that spot. + +But that's a little +heavy-handed. + +Probably I can do something +a little more delicate. + +And so here's the more +delicate thing I'm going to do. + +I want to build a detector +that uses very, very, very + +weak light, extremely +weak light, to detect + +whether the particle went +through here or here. + +And the way I can do that is I +can sort of shine light through + +and-- I'm gonna, you +know, bounce-- so here's + +my source of light. + +And I'll be able to tell +whether the electron went + +through this slit or it +went through this slit. + +Cool? + +So imagine I did that. + +So obviously I don't want to +use some giant, huge, ultra + +high-energy laser because it +would just blast the thing out + +of the way. + +It would destroy the experiment. + +So I wanna something very +diffuse, very low energy, + +very low intensity +electromagnetic wave. + +And the idea here is +that, OK, it's true + +that when I bounce this +light off an electron, + +let's say it bounces +off an electron here, + +it's true it's going +impart some momentum + +and the electron's +gonna change its course. + +But if it's really, really +weak, low energy light, + +then it's-- it's gonna deflect +only a little tiny bit. + +So it will change the +pattern I get over here. + +But it will change it in +some relatively minor way + +because I've just thrown in +very, very low energy light. + +Yeah? + +That make sense? + +So this is the +experiment I want to do. + +This experiment doesn't work. + +Why. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: No. + +It's true that it turns out +that those are correlated facts, + +but here's the problem. + +I can run this experiment +without anyone actually knowing + +what happens until +long afterwards. + +So knowing doesn't seem +to play any role in it. + +It's very tempting +often to say, no, + +but it turns out that it's +really not about what you know. + +It's really just about the +experiment you're doing. + +So what principle +that we've already + +run into today makes it +impossible to make this work? + +If I want to shine +really low-energy, + +really diffuse light through, +and have it scatter weakly. + +Yeah. + +AUDIENCE: Um, light. + +PROFESSOR: Yeah, exactly. + +That's exactly right. + +So when I say really +low-energy light, + +I don't-- I really can't mean, +because we've already done this + +experiment, I cannot +possibly mean low intensity. + +Because intensity doesn't +control the energy + +imparted by the light. + +The thing that controls +the energy imparted + +by a collision of the light with +the electron is the frequency. + +The energy in a +chunk of light is + +proportional to the frequency. + +So now if I want to make +the effect the energy + +or the momentum, +similarly-- the momentum, + +where did it go-- +remember the momentum goes + +like h over lambda. + +If I want to make the +energy really low, + +I need to make the +frequency really low. + +Or if I want to make +the momentum really low, + +I need to make the +wavelength what? + +Really big. + +Right? + +So in order to make the momentum +imparted by this photon really + +low, I need to make the +wavelength really long. + +But now here's the problem. + +If I make the +wavelength really long, + +so if I use a really +long-wavelengthed wave, + +like this long of a +wavelength, are you + +ever going to be able to tell +which slit it went through? + +No, because the particle +could have been anywhere. + +It could have +scattered this light + +if it was here, if it was +here, if it was here, right? + +In order to measure +where the electron is + +to some reasonable precision-- +so, for example, to this sort + +of wavelength, I need +to be able to send + +in light with a wavelength +that's comparable to the scale + +that I want to measure. + +And it turns out that if +you run through and just do + +the calculation, +suppose I send in-- + +and this is done in the +books, in I think all four, + +but this is done in the +books on the reading list-- + +if you send in a wave with +a short enough wavelength + +to be able to distinguish +between these two slits, which + +slit did it go +through, the momentum + +that it imparts precisely +watches-- washes out + +is just enough to wash out +the interference effect, + +and break up these +fringes so you + +don't see interference effects. + +It's not about what you know. + +It's about the particulate +nature of light and the fact + +that the momentum of a chunk of +light goes like h over lambda. + +OK? + +But this tells you something +really interesting. + +Did I have to use light +to do this measurement? + +I could have sent +in anything, right? + +I didn't have to bounce +light off these things. + +I could have bounced +off gravitational waves. + +So if I had a gravitational +wave detector, + +so-- Matt works on +gravitational wave detectors, + +and so, I didn't tell +you this but Matt gave me + +a pretty killer +gravitational wave detector. + +It's, you know, here it is. + +There's my awesome +gravitational wave detector. + +And I'm now going +to build supernova. + +OK. + +And they are creeping +under this black hole, + +and it's going to create +giant gravitational waves. + +And we're gonna use +those gravitational waves + +and detect them with +the super advanced LIGO. + +And I'm gonna detect which +slit it went through. + +But gravitational waves, +those aren't photons. + +So I really can make a +low-intensity gravitational + +wave, and then I can tell +which slit it went through + +without destroying the +interference effect. + +That would be awesome. + +What does that tell you +about gravitational waves? + +They must come in chunks. + +In order for this all to +fit together logically, + +you need all the interactions +that you could scatter off this + +to satisfy these +quantization properties. + +But the energy is +proportional to the frequency. + +The line I just gave +you is a heuristic. + +And making it precise is +one of the great challenges + +of modern contemporary +high-energy physics, + +of dealing with the quantum +mechanics and gravity together. + +But this gives you +a strong picture + +of why we need to +treat all forces + +in all interactions +quantum-mechanically in order + +for the world to be consistent. + +OK. + +Good. + +OK, questions at this point? + +OK. + +So-- oh, I forgot +about this one-- + +so there are actually two more. + +So I want to just quickly +show you-- well, OK. + +So, this is a +gorgeous experiment. + +So remember I told you the +story of the guy with the boat + +and the opaque wall and it +turns out that's a cheat. + +It turns out that this opaque +screen doesn't actually + +give you quantum mechanically +isolated photons. + +They're still, in a very +important way, classical. + +So this experiment was +done truly with a source + +that gives you quantum +mechanically isolated + +single photons, one at a time. + +So this is the analogue +of the Hitachi experiment. + +And it was done by this +pretty awesome Japanese group + +some number of years ago. + +And I just want to +emphasize that it gives you + +exactly the same effects. + +We see that photons-- this +should look essentially + +identical to what we saw at +the end of the Hitachi video. + +And that's because it's +exactly the same physics. + +It's a grating with +something like 10 slits + +and individual particles +going through one at a time + +and hitting the screen +and going, bing. + +So what you see is the +light going, bing, on a CCD. + +It's a pretty +spectacular experience. + +So let's get back to electrons. + +I want another probe of whether +electrons are really waves + +or not. + +So this other +experiment-- again, you're + +going to study this +on your problem + +set-- this other +experiment was done + +by a couple of characters +named Davisson and Germer. + +And in this experiment, +what they did + +is they took a +crystal, and a crystal + +is just a lattice of +regularly-located ions, + +like diamond or something. + +Yeah? + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: Is what, sorry? + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: You mean for +different electrons? + +AUDIENCE: Yeah. + +PROFESSOR: Well they +can be different + +if the initial +conditions are different. + +But they could be-- if +the initial conditions are + +the same, then the +probabilities are identical. + +So every electron +behaves identically + +to every other +electron in that sense. + +Is that what you were asking? + +AUDIENCE: [INAUDIBLE]? + +PROFESSOR: Sure, absolutely. + +So the issue there is +just a technological one + +of trying to build a beam +that's perfectly columnated. + +And that's just not doable. + +So there's always some +dispersion in your beam. + +So in practice it's very +hard to make them identical, + +but in principle they could +be if you were infinitely + +powerful as an experimentalist, +which-- again, I + +was banned from +the lab, so not me. + +So here's our crystal. + +You could think of this as +diamond or nickel or whatever. + +I think they actually use nickel +but I don't remember exactly. + +And they sent in a +beam of electrons. + +So they send in a +beam of electrons, + +and what they discover is that +if you send in these electrons + +and watch how they scatter +at various different angles-- + +I'm going to call the angle +here of scattering theta-- + +what they discover +is that the intensity + +of the reflected beam, +as a function of theta, + +shows interference effects. + +And in particular they +gave a whole calculation + +for this, which I'm +not going to go through + +right now because it's not +terribly germane for us-- + +you're going to go through +it on your problem set, + +so that'll be good and +it's a perfect thing + +for your recitation +instructors to go through. + +But the important +thing is the upshot. + +So if the distance between +these crystal planes + +is L-- or, sorry, +d-- let me call it d. + +If the distance between +the crystal planes + +is d, what they discover is +that the interference effects + +that they observed, +these maxima and minima, + +are consistent with the +wavelength of light. + +Or, sorry, with the +electrons behaving + +as if they were waves with +a definite wavelength, + +with a wavelength lambda +being equal to some integer, + +n, over 2d sine theta. + +So this is the data-- these +are the data they actually saw, + +data are plural. + +And these are the data +they actually saw. + +And they infer from +this that the electrons + +are behaving as if they were +wave-like with this wavelength. + +And what they actually see +are individual electrons + +hitting one by one. + +Although in their +experiment, they + +couldn't resolve +individual electrons. + +But that is what they see. + +And so in particular, +plugging all of this back + +into the experiment, you +send in the electrons + +with some energy, +which corresponds + +to some definite momentum. + +This leads us back to +the same expression + +as before, that the +momentum is equal to h + +over lambda, with this +lambda associated. + +So it turns out that +this is correct. + +So the electrons +diffract off the crystal + +as if they have a +momentum which comes + +with a definite wavelength +corresponding to its momentum. + +So that's experimental +result-- oh, I + +forgot to check off four-- +that's experimental result + +five, that electrons diffract. + +We already saw the +electron diffraction. + +So something to emphasize is +that-- so these experiments + +as we've described +them were done + +with photons and with +electrons, but you + +can imagine doing the +experiments with soccer balls. + +This is of course hard. + +Quantum effects for +macroscopic objects + +are usually +insignificantly small. + +However, this +experiment was done + +with Buckyballs, which are +the same shape as soccer + +balls in some sense. + +But they're huge, +they're gigantic objects. + +So here's the experiment in +which this was actually done. + +So these guys are +just totally amazing. + +So this is Zellinger's lab. + +And it doesn't look like +all-- I mean it looks kind of, + +you know. + +It's hideous, right? + +I mean to a theorist it's +like, come on, you've got to be + +kidding that that's-- + +But here's what a +theorist is happy about. + +You know, because +it looks simple. + +We really love lying to +ourselves about that. + +So here's an over. + +We're going to cook +up some Buckyballs + +and emit them with some +definite known thermal energy. + +Known to some accuracy. + +We're going to columnate +them by sending them + +through a single +slit, and then we're + +going to send them through +a diffraction grating which, + +again, is just a +whole bunch of slits. + +And then we're going to image +them using photo ionization + +and see where they pop through. + +So here is the +horizontal position + +of this wave along +the grating, and this + +is the number that come through. + +This is literally +one by one counts + +because they're +going bing, bing, + +bing, as a c60 +molecule goes through. + +So without the grating, +you just get a peek. + +But with the grating, +you get the side bands. + +You get interference fringes. + +So these guys, again, they're +going through one by one. + +A single Buckyball, 60 carbons, +going through one by one + +is interfering with itself. + +This is a gigantic object +by any sort of comparison + +to single electrons. + +And we're seeing these +interference fringes. + +So this is a pretty tour +de force experiment, + +but I just want to +emphasize that if you could + +do this with your +neighbor, it would work. + +You'd just have to isolate +the system well enough. + +And that's a technological +challenge but not + +an in-principle one. + +OK. + +So we have one last +experimental facts to deal with. + +And this is Bell's Inequality, +and this is my favorite one. + +So Bell's Inequality for many +years languished in obscurity + +until someone realized +that it could actually + +be done beautifully +in an experiment that + +led to a very +concrete experiment + +that they could actually do +and that they wanted to do. + +And we now think of it as an +enormously influential idea + +which nails the coffin closed +for classical mechanics. + +And it starts with a +very simple question. + +I claim that the +following inequality + +is true: the number +of undergraduate-- + +of the number of +people in the room + +who are undergraduates, +which I'll denote as U-- + +and not blonde, which I +will denote as bar B-- + +so undergraduates who +are not blonde-- actually + +let me write this +out in English. + +It's gonna be easier. + +Number who are +undergrads and not blonde + +plus the number of +people in the room who + +are blonde but not +from Massachusetts + +is strictly greater than or +equal to the number of people + +in the room who are +undergraduates and not + +from Massachusetts. + +I claim that this is true. + +I haven't checked in this room. + +But I claim that this is true. + +So let's check. + +How many people +are undergraduates + +who are not blonde? + +OK this is going to-- jeez. + +OK that's-- so, lots. + +OK. + +How many people are blonde +but not from Massachusetts? + +OK. + +A smattering. + +Oh God, this is actually +going to be terrible. + +AUDIENCE: [LAUGHTER] + +PROFESSOR: Shoot. + +This is a really large class. + +OK. + +Small. + +And how many people +are undergraduates + +who are not from Massachusetts? + +Yeah, this-- oh God. + +This counting is going to be-- +so let's-- I'm going to do this + +just so I can do the counting +with the first two rows here. + +OK. + +My life is going to +be easier this way. + +So how many people in the +first two rows, in the center + +section, are undergraduates +but not blonde? + +One, two, three, four, five, +six, seven, eight, nine, ten, + +eleven, twelve, +thirteen, fourteen. + +We could dispute some +of those, but we'll + +take it for the moment. + +So, fourteen. + +You're probably +all undergraduates. + +So blonde and not +from Massachusetts. + +One. + +Awesome. + +Undergraduates not +from Massachusetts. + +One, two, three, four, five, +six, seven, eight, nine, ten, + +eleven, twelve, thirteen, +fourteen, fifteen. + +Equality. + +AUDIENCE: [LAUGHTER] + +PROFESSOR: OK. + +So that-- you might +say well, look, + +you should have +been nervous there. + +You know, and admittedly +sometimes there's + +experimental error. + +But I want to convince you that +I should never, ever ever be + +nervous about this +moment in 804. + +And the reason is the following. + +I want to prove this for you. + +And the way I'm gonna prove +it is slightly more general, + +in more generality. + +And I want to prove to you that +the number-- if I have a set, + +or, sorry, if the number of +people who are undergraduates + +and not blonde which, all right, +is b bar plus the number who + +are blonde but not +from Massachusetts + +is greater than or equal to the +number that are undergraduates + +and not from Massachusetts. + +So how do I prove this? + +Well if you're an +undergraduate and not blonde, + +you may or you may not +be from Massachusetts. + +So this is equal to the +number of undergraduates + +who are not blonde and +are from Massachusetts + +plus the number of +undergraduates who are not + +blonde and are not +from Massachusetts. + +It could hardly be otherwise. + +You either are or you are +not from Massachusetts. + +Not the sort of thing that +you normally see in physics. + +So this is the +number of people who + +are blonde and not from +Massachusetts, number of people + +who are blonde, who are-- +so if you're blonde and not + +from Massachusetts, you may or +may not be an undergraduate. + +So this is the number of people +who are undergraduates, blonde, + +and not from Massachusetts +plus the number + +of people who are not +undergraduates, are blonde + +and are not from Massachusetts. + +And on the right hand +side-- so, adding these two + +together gives us plus and plus. + +On the right hand +side, the number + +of people that are +undergraduates and not + +from Massachusetts, +well each one + +could be either +blonde or not blonde. + +So this is equal to the number +that are undergraduates, + +blonde, and not +from Massachusetts, + +plus-- remember that +our undergraduates + +not blonde and not +from Massachusetts. + +Agreed? + +I am now going to use +the awesome power of-- + +and so this is what +we want to prove, + +and I'm going to use the +awesome power of subtraction. + +And note that U, B, M +bar, these guys cancel. + +And U, B bar, M bar, +these guys cancel. + +And we're left with the +following proposition: + +the number of undergraduates +who are not blonde + +but are from Massachusetts +plus the number of undergrad-- + +of non-undergraduates +who are blonde + +but not from +Massachusetts must be + +greater than or equal to zero. + +Can you have a number of +people in a room satisfying + +some condition be +less than zero? + +Can minus 3 of you be +blonde undergraduates + +not from Massachusetts? + +Not so much. + +This is a strictly +positive number, + +because it's a numerative. + +It's a counting problem. + +How many are undergraduates not +blonde and from Massachusetts. + +Yeah? + +Everyone cool with that? + +So it could hardly +have been otherwise. + +It had to work out like this. + +And here's the more +general statement. + +The more general statement +is that the number of people, + +or the number of +elements of any set + +where each element in that +set has binary properties a + +b and c-- a or not a, +b or not b, c or not c. + +Satisfies the +following inequality. + +The number who are a but +not b plus the number who + +are b but not c is greater +than or equal to the number who + +are a but not c. + +And this is exactly +the same argument. + +And this inequality which +is a tautology, really, + +is called Bell's Inequality. + +And it's obviously true. + +What did I use to derive this? + +Logic and integers, right? + +I mean, that's bedrock stuff. + +Here's the problem. + +I didn't mention this last +time, but in fact electrons + +have a third +property in addition + +to-- electrons have a +third property in addition + +to hardness and color. + +The third property +is called whimsy, + +and you can either be +whimsical or not whimsical. + +And every electron, +when measured, + +is either whimsical +or not whimsical. + +You never have a +boring electron. + +You never have an +ambiguous electron. + +Always whimsical +or not whimsical. + +So we have hardness, we +have color, we have whimsy. + +OK. + +And I can perform the +following experiment. + +From a set of +electrons, I can measure + +the number that are +hard and not black, + +plus the number that are +black but not whimsical. + +And I can measure +the number that + +are hard and not whimsical. + +OK? + +And I want to just open +up the case a little bit + +and tell you that the +hardness here really + +is the angular momentum of +the electron along the x-axis. + +Color is the angular momentum of +the electron along the y-axis. + +And whimsy is the +angular momentum + +of the electron +along the z-axis. + +These are things I +can measure because I + +can measure angular momentum. + +So I can perform this +experiment with electrons + +and it needn't be satisfied. + +In particular, we will show that +the number of electrons, just + +to be very precise, the +number of electrons in a given + +set, which have positive angular +momentum along the x-axis + +and down along the +y-axis, plus up along + +the y-axis and down +along the z-axis, + +is less than the +number that are up. + +Actually let me do this +in a very particular way. + +Up at zero, down at theta. + +Up at theta, down +at-- to theta is + +greater than the number that are +up at zero and down at theta. + +Now here's the thing-- to theta. + +You can't at the +moment understand + +what this equation means. + +But if I just tell +you that these + +are three binary properties +of the electron, OK, + +and that it violates +this inequality, + +there is something deeply +troubling about this result. + +Bell's Inequality, which +we proved-- trivially, + +using integers, using logic-- +is false in quantum mechanics. + +And it's not just false +in quantum mechanics. + +We will at the end +of the course derive + +the quantum mechanical +prediction for this result + +and show that at least +to a predicted violation + +of Bell's Inequality. + +This experiment has been +done, and the real world + +violates Bell's Inequality. + +Logic and integers and adding +probabilities, as we have done, + +is misguided. + +And our job, which we will +begin with the next lecture, + +is to find a better way to add +probabilities than classically. + +And that will be quantum +mechanics See you on Tuesday. + +AUDIENCE: [APPLAUSE] \ No newline at end of file diff --git a/TqO6V3qR9Ws.txt b/TqO6V3qR9Ws.txt new file mode 100644 index 0000000000000000000000000000000000000000..81613142eb57cecc67888b46f132d3595fa9d04e --- /dev/null +++ b/TqO6V3qR9Ws.txt @@ -0,0 +1,7147 @@ +align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +last time we took a look at an explicit + + align:start position:0% +last time we took a look at an explicit + + + align:start position:0% +last time we took a look at an explicit +control evaluator for Lisp and that + + align:start position:0% +control evaluator for Lisp and that + + + align:start position:0% +control evaluator for Lisp and that +bridged the gap between all these + + align:start position:0% +bridged the gap between all these + + + align:start position:0% +bridged the gap between all these +high-level languages like Lisp in the + + align:start position:0% +high-level languages like Lisp in the + + + align:start position:0% +high-level languages like Lisp in the +query language and all of that stuff + + align:start position:0% +query language and all of that stuff + + + align:start position:0% +query language and all of that stuff +bridges the gap between that and a + + align:start position:0% +bridges the gap between that and a + + + align:start position:0% +bridges the gap between that and a +conventional register machine and in + + align:start position:0% +conventional register machine and in + + + align:start position:0% +conventional register machine and in +fact you can think of the explicit + + align:start position:0% +fact you can think of the explicit + + + align:start position:0% +fact you can think of the explicit +control evaluator either as say the code + + align:start position:0% +control evaluator either as say the code + + + align:start position:0% +control evaluator either as say the code +for a lisp interpreter if you wanted to + + align:start position:0% +for a lisp interpreter if you wanted to + + + align:start position:0% +for a lisp interpreter if you wanted to +implement it in the the assembly + + align:start position:0% +implement it in the the assembly + + + align:start position:0% +implement it in the the assembly +language of some conventional register + + align:start position:0% +language of some conventional register + + + align:start position:0% +language of some conventional register +transfer machine or if you like you can + + align:start position:0% +transfer machine or if you like you can + + + align:start position:0% +transfer machine or if you like you can +think of it as the Micra code of some + + align:start position:0% +think of it as the Micra code of some + + + align:start position:0% +think of it as the Micra code of some +machine that's going to be specially + + align:start position:0% +machine that's going to be specially + + + align:start position:0% +machine that's going to be specially +designed to run Lisp in either case what + + align:start position:0% +designed to run Lisp in either case what + + + align:start position:0% +designed to run Lisp in either case what +we're doing is we're taking a machine + + align:start position:0% +we're doing is we're taking a machine + + + align:start position:0% +we're doing is we're taking a machine +that speaks some low-level language and + + align:start position:0% +that speaks some low-level language and + + + align:start position:0% +that speaks some low-level language and +we're raising the machine to a high + + align:start position:0% +we're raising the machine to a high + + + align:start position:0% +we're raising the machine to a high +level language like Lisp by writing an + + align:start position:0% +level language like Lisp by writing an + + + align:start position:0% +level language like Lisp by writing an +interpreter so for instance here + + align:start position:0% +interpreter so for instance here + + + align:start position:0% +interpreter so for instance here +conceptually but here conceptually is a + + align:start position:0% +conceptually but here conceptually is a + + + align:start position:0% +conceptually but here conceptually is a +special-purpose machine for computing + + align:start position:0% +special-purpose machine for computing + + + align:start position:0% +special-purpose machine for computing +factorials it takes in v and puts out + + align:start position:0% +factorials it takes in v and puts out + + + align:start position:0% +factorials it takes in v and puts out +120 and what this special purpose + + align:start position:0% +120 and what this special purpose + + + align:start position:0% +120 and what this special purpose +machine is is actually a lisp + + align:start position:0% +machine is is actually a lisp + + + align:start position:0% +machine is is actually a lisp +interpreter that's configured itself to + + align:start position:0% +interpreter that's configured itself to + + + align:start position:0% +interpreter that's configured itself to +run factorials because you fed into it a + + align:start position:0% +run factorials because you fed into it a + + + align:start position:0% +run factorials because you fed into it a +description of the factorial machine + + align:start position:0% +description of the factorial machine + + + align:start position:0% +description of the factorial machine +right so that's what an interpreter is + + align:start position:0% +right so that's what an interpreter is + + + align:start position:0% +right so that's what an interpreter is +it configures itself to emulate a + + align:start position:0% +it configures itself to emulate a + + + align:start position:0% +it configures itself to emulate a +machine whose description you run you + + align:start position:0% +machine whose description you run you + + + align:start position:0% +machine whose description you run you +read in now inside the Lisp interpreter + + align:start position:0% +read in now inside the Lisp interpreter + + + align:start position:0% +read in now inside the Lisp interpreter +what's that well that might be a general + + align:start position:0% +what's that well that might be a general + + + align:start position:0% +what's that well that might be a general +register language interpreter that + + align:start position:0% +register language interpreter that + + + align:start position:0% +register language interpreter that +configures itself to behave like a lisp + + align:start position:0% +configures itself to behave like a lisp + + + align:start position:0% +configures itself to behave like a lisp +interpreter because you put in a whole + + align:start position:0% +interpreter because you put in a whole + + + align:start position:0% +interpreter because you put in a whole +bunch of instructions in register + + align:start position:0% +bunch of instructions in register + + + align:start position:0% +bunch of instructions in register +language this is the explicit control + + align:start position:0% +language this is the explicit control + + + align:start position:0% +language this is the explicit control +evaluator and then it also has some sort + + align:start position:0% +evaluator and then it also has some sort + + + align:start position:0% +evaluator and then it also has some sort +of library library of primitive + + align:start position:0% +of library library of primitive + + + align:start position:0% +of library library of primitive +operators and Lisp operations and all + + align:start position:0% +operators and Lisp operations and all + + + align:start position:0% +operators and Lisp operations and all +sorts of things like that + + align:start position:0% +sorts of things like that + + + align:start position:0% +sorts of things like that +that's the general strategy of + + align:start position:0% +that's the general strategy of + + + align:start position:0% +that's the general strategy of +interpretation and the point is what + + align:start position:0% +interpretation and the point is what + + + align:start position:0% +interpretation and the point is what +we're doing is we're writing an + + align:start position:0% +we're doing is we're writing an + + + align:start position:0% +we're doing is we're writing an +interpreter to raise the machine to the + + align:start position:0% +interpreter to raise the machine to the + + + align:start position:0% +interpreter to raise the machine to the +level of the programs that we want to + + align:start position:0% +level of the programs that we want to + + + align:start position:0% +level of the programs that we want to +write well there's another strategy + + align:start position:0% +write well there's another strategy + + + align:start position:0% +write well there's another strategy +different one which is compilation + + align:start position:0% +different one which is compilation + + + align:start position:0% +different one which is compilation +compilations a little bit different + + align:start position:0% +compilations a little bit different + + + align:start position:0% +compilations a little bit different +here here we might have produced a + + align:start position:0% +here here we might have produced a + + + align:start position:0% +here here we might have produced a +special purpose machine for for + + align:start position:0% +special purpose machine for for + + + align:start position:0% +special purpose machine for for +computing factorials starting with some + + align:start position:0% +computing factorials starting with some + + + align:start position:0% +computing factorials starting with some +sort of machine that speaks register + + align:start position:0% +sort of machine that speaks register + + + align:start position:0% +sort of machine that speaks register +language except we're going to do a + + align:start position:0% +language except we're going to do a + + + align:start position:0% +language except we're going to do a +different strategy we'll take our + + align:start position:0% +different strategy we'll take our + + + align:start position:0% +different strategy we'll take our +factorial program we'll use that as the + + align:start position:0% +factorial program we'll use that as the + + + align:start position:0% +factorial program we'll use that as the +source code into a compiler what the + + align:start position:0% +source code into a compiler what the + + + align:start position:0% +source code into a compiler what the +compiler will do is translate that + + align:start position:0% +compiler will do is translate that + + + align:start position:0% +compiler will do is translate that +factorial program into some register in + + align:start position:0% +factorial program into some register in + + + align:start position:0% +factorial program into some register in +machine language and this will now be + + align:start position:0% +machine language and this will now be + + + align:start position:0% +machine language and this will now be +not the explicit control evaluator for + + align:start position:0% +not the explicit control evaluator for + + + align:start position:0% +not the explicit control evaluator for +Lisp this will be some register language + + align:start position:0% +Lisp this will be some register language + + + align:start position:0% +Lisp this will be some register language +for computing factorials right so this + + align:start position:0% +for computing factorials right so this + + + align:start position:0% +for computing factorials right so this +is the translation of that that will go + + align:start position:0% +is the translation of that that will go + + + align:start position:0% +is the translation of that that will go +into some sort of loader which will + + align:start position:0% +into some sort of loader which will + + + align:start position:0% +into some sort of loader which will +combine this code with code selected + + align:start position:0% +combine this code with code selected + + + align:start position:0% +combine this code with code selected +from the library to do things like + + align:start position:0% +from the library to do things like + + + align:start position:0% +from the library to do things like +primitive multiplication and then we'll + + align:start position:0% +primitive multiplication and then we'll + + + align:start position:0% +primitive multiplication and then we'll +produce a load module which configures + + align:start position:0% +produce a load module which configures + + + align:start position:0% +produce a load module which configures +the register language machine to be a + + align:start position:0% +the register language machine to be a + + + align:start position:0% +the register language machine to be a +special-purpose factorial machine so + + align:start position:0% +special-purpose factorial machine so + + + align:start position:0% +special-purpose factorial machine so +that's a that's a different strategy and + + align:start position:0% +that's a that's a different strategy and + + + align:start position:0% +that's a that's a different strategy and +interpretation we're raising the machine + + align:start position:0% +interpretation we're raising the machine + + + align:start position:0% +interpretation we're raising the machine +to the level of our language like list + + align:start position:0% +to the level of our language like list + + + align:start position:0% +to the level of our language like list +in compilation we're taking our program + + align:start position:0% +in compilation we're taking our program + + + align:start position:0% +in compilation we're taking our program +and lowering it to the language that's + + align:start position:0% +and lowering it to the language that's + + + align:start position:0% +and lowering it to the language that's +spoken by the machine well how do these + + align:start position:0% +spoken by the machine well how do these + + + align:start position:0% +spoken by the machine well how do these +two strategies compare the compiler can + + align:start position:0% +two strategies compare the compiler can + + + align:start position:0% +two strategies compare the compiler can +produce code that will execute more + + align:start position:0% +produce code that will execute more + + + align:start position:0% +produce code that will execute more +efficiently the essential reason for + + align:start position:0% +efficiently the essential reason for + + + align:start position:0% +efficiently the essential reason for +that is that if you if you think about + + align:start position:0% +that is that if you if you think about + + + align:start position:0% +that is that if you if you think about +the register operations that are running + + align:start position:0% + + + + align:start position:0% + +the interpreter has to produce register + + align:start position:0% +the interpreter has to produce register + + + align:start position:0% +the interpreter has to produce register +operations which in principle are going + + align:start position:0% +operations which in principle are going + + + align:start position:0% +operations which in principle are going +to be general enough to execute any list + + align:start position:0% +to be general enough to execute any list + + + align:start position:0% +to be general enough to execute any list +procedure whereas the compiler only has + + align:start position:0% +procedure whereas the compiler only has + + + align:start position:0% +procedure whereas the compiler only has +to worry about producing a special bunch + + align:start position:0% +to worry about producing a special bunch + + + align:start position:0% +to worry about producing a special bunch +of register operations for for doing the + + align:start position:0% +of register operations for for doing the + + + align:start position:0% +of register operations for for doing the +particular list procedure that you've + + align:start position:0% +particular list procedure that you've + + + align:start position:0% +particular list procedure that you've +compiled or another way to say that is + + align:start position:0% +compiled or another way to say that is + + + align:start position:0% +compiled or another way to say that is +that the interpreter is a + + align:start position:0% +that the interpreter is a + + + align:start position:0% +that the interpreter is a +general-purpose simulator that when you + + align:start position:0% +general-purpose simulator that when you + + + align:start position:0% +general-purpose simulator that when you +read in a list procedure then goes can + + align:start position:0% +read in a list procedure then goes can + + + align:start position:0% +read in a list procedure then goes can +simulate the program described by that + + align:start position:0% +simulate the program described by that + + + align:start position:0% +simulate the program described by that +by that procedure so the interpreter is + + align:start position:0% +by that procedure so the interpreter is + + + align:start position:0% +by that procedure so the interpreter is +worrying about making a general-purpose + + align:start position:0% +worrying about making a general-purpose + + + align:start position:0% +worrying about making a general-purpose +simulator whereas the compiler in effect + + align:start position:0% +simulator whereas the compiler in effect + + + align:start position:0% +simulator whereas the compiler in effect +is configuring the thing to be the + + align:start position:0% +is configuring the thing to be the + + + align:start position:0% +is configuring the thing to be the +machine that the interpreter would have + + align:start position:0% +machine that the interpreter would have + + + align:start position:0% +machine that the interpreter would have +been simulating so the compiler can be + + align:start position:0% +been simulating so the compiler can be + + + align:start position:0% +been simulating so the compiler can be +faster + + align:start position:0% + + + + align:start position:0% + +okay on the other hand the interpreter + + align:start position:0% +okay on the other hand the interpreter + + + align:start position:0% +okay on the other hand the interpreter +is a nicer environment for debugging and + + align:start position:0% +is a nicer environment for debugging and + + + align:start position:0% +is a nicer environment for debugging and +the reason for that is that we've got + + align:start position:0% +the reason for that is that we've got + + + align:start position:0% +the reason for that is that we've got +the the source code actually there we're + + align:start position:0% +the the source code actually there we're + + + align:start position:0% +the the source code actually there we're +interpreting it that's what we're + + align:start position:0% +interpreting it that's what we're + + + align:start position:0% +interpreting it that's what we're +working with and we also have the + + align:start position:0% +working with and we also have the + + + align:start position:0% +working with and we also have the +library around see the interpreter the + + align:start position:0% +library around see the interpreter the + + + align:start position:0% +library around see the interpreter the +library sitting there as part of the + + align:start position:0% +library sitting there as part of the + + + align:start position:0% +library sitting there as part of the +interpreter the compiler only pulls out + + align:start position:0% +interpreter the compiler only pulls out + + + align:start position:0% +interpreter the compiler only pulls out +from the library what it needs to run + + align:start position:0% +from the library what it needs to run + + + align:start position:0% +from the library what it needs to run +the program so if you if you're in the + + align:start position:0% +the program so if you if you're in the + + + align:start position:0% +the program so if you if you're in the +middle of debugging and you might like + + align:start position:0% +middle of debugging and you might like + + + align:start position:0% +middle of debugging and you might like +to write a little extra program to + + align:start position:0% +to write a little extra program to + + + align:start position:0% +to write a little extra program to +examine some runtime data structure or + + align:start position:0% +examine some runtime data structure or + + + align:start position:0% +examine some runtime data structure or +to produce some computation that you + + align:start position:0% +to produce some computation that you + + + align:start position:0% +to produce some computation that you +didn't think of when you wrote the + + align:start position:0% +didn't think of when you wrote the + + + align:start position:0% +didn't think of when you wrote the +program the interpreter can do that + + align:start position:0% +program the interpreter can do that + + + align:start position:0% +program the interpreter can do that +perfectly well whereas the compiler + + align:start position:0% +perfectly well whereas the compiler + + + align:start position:0% +perfectly well whereas the compiler +can't so they're sort of dual dual + + align:start position:0% +can't so they're sort of dual dual + + + align:start position:0% +can't so they're sort of dual dual +advantages the compiler will produce + + align:start position:0% +advantages the compiler will produce + + + align:start position:0% +advantages the compiler will produce +code that executes the Aster the + + align:start position:0% +code that executes the Aster the + + + align:start position:0% +code that executes the Aster the +interpreter is a better environment for + + align:start position:0% +interpreter is a better environment for + + + align:start position:0% +interpreter is a better environment for +debugging and most Lisp systems end up + + align:start position:0% +debugging and most Lisp systems end up + + + align:start position:0% +debugging and most Lisp systems end up +having both end up being configured so + + align:start position:0% +having both end up being configured so + + + align:start position:0% +having both end up being configured so +you have an interpreter that you use + + align:start position:0% +you have an interpreter that you use + + + align:start position:0% +you have an interpreter that you use +when you're developing your code then + + align:start position:0% +when you're developing your code then + + + align:start position:0% +when you're developing your code then +you can speed it up by compiling and + + align:start position:0% +you can speed it up by compiling and + + + align:start position:0% +you can speed it up by compiling and +very often you can arrange that compiled + + align:start position:0% +very often you can arrange that compiled + + + align:start position:0% +very often you can arrange that compiled +code and interpreted code can call each + + align:start position:0% +code and interpreted code can call each + + + align:start position:0% +code and interpreted code can call each +other and we'll see how to do that + + align:start position:0% +other and we'll see how to do that + + + align:start position:0% +other and we'll see how to do that +that's not hard okay in fact the way + + align:start position:0% +that's not hard okay in fact the way + + + align:start position:0% +that's not hard okay in fact the way +well in the compiler we're going to make + + align:start position:0% +well in the compiler we're going to make + + + align:start position:0% +well in the compiler we're going to make +the way we'll arrange for compiled + + align:start position:0% +the way we'll arrange for compiled + + + align:start position:0% +the way we'll arrange for compiled +coding interpreted code to encourage + + align:start position:0% +coding interpreted code to encourage + + + align:start position:0% +coding interpreted code to encourage +other is that we'll have the compiler + + align:start position:0% +other is that we'll have the compiler + + + align:start position:0% +other is that we'll have the compiler +use exactly the same register + + align:start position:0% +use exactly the same register + + + align:start position:0% +use exactly the same register +conventions as the interpreter all right + + align:start position:0% +conventions as the interpreter all right + + + align:start position:0% +conventions as the interpreter all right +well the the idea of a of a compiler is + + align:start position:0% +well the the idea of a of a compiler is + + + align:start position:0% +well the the idea of a of a compiler is +very much like the idea of an + + align:start position:0% +very much like the idea of an + + + align:start position:0% +very much like the idea of an +interpreter or valuator it's the same + + align:start position:0% +interpreter or valuator it's the same + + + align:start position:0% +interpreter or valuator it's the same +thing see the evaluator walks over the + + align:start position:0% +thing see the evaluator walks over the + + + align:start position:0% +thing see the evaluator walks over the +code and perform some register + + align:start position:0% +code and perform some register + + + align:start position:0% +code and perform some register +operations but that's what we did + + align:start position:0% +operations but that's what we did + + + align:start position:0% +operations but that's what we did +yesterday well the compiler essentially + + align:start position:0% +yesterday well the compiler essentially + + + align:start position:0% +yesterday well the compiler essentially +would like to walk over the code and + + align:start position:0% +would like to walk over the code and + + + align:start position:0% +would like to walk over the code and +produce the register operations that the + + align:start position:0% +produce the register operations that the + + + align:start position:0% +produce the register operations that the +evaluator would have done worried + + align:start position:0% +evaluator would have done worried + + + align:start position:0% +evaluator would have done worried +evaluating the thing right and that + + align:start position:0% +evaluating the thing right and that + + + align:start position:0% +evaluating the thing right and that +gives us a model for how to implement a + + align:start position:0% +gives us a model for how to implement a + + + align:start position:0% +gives us a model for how to implement a +zeroth-order compiler right a very dada + + align:start position:0% +zeroth-order compiler right a very dada + + + align:start position:0% +zeroth-order compiler right a very dada +compiler but a + + align:start position:0% +compiler but a + + + align:start position:0% +compiler but a +essentially a compiler a model for doing + + align:start position:0% +essentially a compiler a model for doing + + + align:start position:0% +essentially a compiler a model for doing +that is you just take the evaluator you + + align:start position:0% +that is you just take the evaluator you + + + align:start position:0% +that is you just take the evaluator you +run it over the code but instead of + + align:start position:0% +run it over the code but instead of + + + align:start position:0% +run it over the code but instead of +executing the actual operations you just + + align:start position:0% +executing the actual operations you just + + + align:start position:0% +executing the actual operations you just +save them away and that's your compiled + + align:start position:0% +save them away and that's your compiled + + + align:start position:0% +save them away and that's your compiled +code so let me give you an example of + + align:start position:0% +code so let me give you an example of + + + align:start position:0% +code so let me give you an example of +that it's suppose we're gonna compile + + align:start position:0% +that it's suppose we're gonna compile + + + align:start position:0% +that it's suppose we're gonna compile +suppose we want to compile the + + align:start position:0% +suppose we want to compile the + + + align:start position:0% +suppose we want to compile the +expression f of X so let's assume that + + align:start position:0% +expression f of X so let's assume that + + + align:start position:0% +expression f of X so let's assume that +we've got f of X in the X register and + + align:start position:0% +we've got f of X in the X register and + + + align:start position:0% +we've got f of X in the X register and +something in the environment register + + align:start position:0% +something in the environment register + + + align:start position:0% +something in the environment register +and now imagine starting up the + + align:start position:0% +and now imagine starting up the + + + align:start position:0% +and now imagine starting up the +evaluator well it looks at the + + align:start position:0% +evaluator well it looks at the + + + align:start position:0% +evaluator well it looks at the +expression and it sees that it's an + + align:start position:0% +expression and it sees that it's an + + + align:start position:0% +expression and it sees that it's an +application and it branches to a place + + align:start position:0% +application and it branches to a place + + + align:start position:0% +application and it branches to a place +in the evaluator code we saw a called + + align:start position:0% +in the evaluator code we saw a called + + + align:start position:0% +in the evaluator code we saw a called +Evie application and then it begins it + + align:start position:0% +Evie application and then it begins it + + + align:start position:0% +Evie application and then it begins it +stores away the operands and uh Neve and + + align:start position:0% +stores away the operands and uh Neve and + + + align:start position:0% +stores away the operands and uh Neve and +then it's going to put the the operator + + align:start position:0% +then it's going to put the the operator + + + align:start position:0% +then it's going to put the the operator +in X but it's going to go recursively + + align:start position:0% +in X but it's going to go recursively + + + align:start position:0% +in X but it's going to go recursively +evaluated that's the process that we + + align:start position:0% +evaluated that's the process that we + + + align:start position:0% +evaluated that's the process that we +walk through and if you start looking at + + align:start position:0% +walk through and if you start looking at + + + align:start position:0% +walk through and if you start looking at +the code you start seeing some register + + align:start position:0% +the code you start seeing some register + + + align:start position:0% +the code you start seeing some register +operations you see a sign to any of the + + align:start position:0% +operations you see a sign to any of the + + + align:start position:0% +operations you see a sign to any of the +operands assigned to X the operator save + + align:start position:0% +operands assigned to X the operator save + + + align:start position:0% +operands assigned to X the operator save +the environment generate that and so on + + align:start position:0% +the environment generate that and so on + + + align:start position:0% +the environment generate that and so on +it's well if we look on on the overhead + + align:start position:0% +it's well if we look on on the overhead + + + align:start position:0% +it's well if we look on on the overhead +here we can see we can see those + + align:start position:0% +here we can see we can see those + + + align:start position:0% +here we can see we can see those +operations starting to be produced + + align:start position:0% +operations starting to be produced + + + align:start position:0% +operations starting to be produced +here's sort of the first real operation + + align:start position:0% +here's sort of the first real operation + + + align:start position:0% +here's sort of the first real operation +that the evaluator would have done it + + align:start position:0% +that the evaluator would have done it + + + align:start position:0% +that the evaluator would have done it +pulls the operands out of the X register + + align:start position:0% +pulls the operands out of the X register + + + align:start position:0% +pulls the operands out of the X register +and assigns it to NF and then it + + align:start position:0% +and assigns it to NF and then it + + + align:start position:0% +and assigns it to NF and then it +assigned something to the expression + + align:start position:0% +assigned something to the expression + + + align:start position:0% +assigned something to the expression +register and it saves continue and it + + align:start position:0% +register and it saves continue and it + + + align:start position:0% +register and it saves continue and it +saves and all I'm doing here is writing + + align:start position:0% +saves and all I'm doing here is writing + + + align:start position:0% +saves and all I'm doing here is writing +down the register assignments that the + + align:start position:0% +down the register assignments that the + + + align:start position:0% +down the register assignments that the +evaluator would have done in executing + + align:start position:0% +evaluator would have done in executing + + + align:start position:0% +evaluator would have done in executing +that code and can zoom out a little bit + + align:start position:0% +that code and can zoom out a little bit + + + align:start position:0% +that code and can zoom out a little bit +altogether there that nineteen + + align:start position:0% +altogether there that nineteen + + + align:start position:0% +altogether there that nineteen +operations there and this is the peak + + align:start position:0% +operations there and this is the peak + + + align:start position:0% +operations there and this is the peak +this will be the piece of code up until + + align:start position:0% +this will be the piece of code up until + + + align:start position:0% +this will be the piece of code up until +the point where the evaluator branches + + align:start position:0% +the point where the evaluator branches + + + align:start position:0% +the point where the evaluator branches +off to apply dispatch and in fact in + + align:start position:0% +off to apply dispatch and in fact in + + + align:start position:0% +off to apply dispatch and in fact in +this compiler we're not going to worry + + align:start position:0% +this compiler we're not going to worry + + + align:start position:0% +this compiler we're not going to worry +about applied dispatch at all we're + + align:start position:0% +about applied dispatch at all we're + + + align:start position:0% +about applied dispatch at all we're +gonna have every we're gonna have both + + align:start position:0% +gonna have every we're gonna have both + + + align:start position:0% +gonna have every we're gonna have both +interpreted code and compile code always + + align:start position:0% +interpreted code and compile code always + + + align:start position:0% +interpreted code and compile code always +evaluate procedures always apply + + align:start position:0% +evaluate procedures always apply + + + align:start position:0% +evaluate procedures always apply +procedures by going to apply dispatch + + align:start position:0% +procedures by going to apply dispatch + + + align:start position:0% +procedures by going to apply dispatch +that will easily allow interpreted code + + align:start position:0% +that will easily allow interpreted code + + + align:start position:0% +that will easily allow interpreted code +and compiled code to call each other + + align:start position:0% +and compiled code to call each other + + + align:start position:0% +and compiled code to call each other +okay well in principle that's all we + + align:start position:0% +okay well in principle that's all we + + + align:start position:0% +okay well in principle that's all we +need to do you just run the evaluator + + align:start position:0% +need to do you just run the evaluator + + + align:start position:0% +need to do you just run the evaluator +see the compilers a lot like the + + align:start position:0% +see the compilers a lot like the + + + align:start position:0% +see the compilers a lot like the +evaluator you run it except it stashes + + align:start position:0% +evaluator you run it except it stashes + + + align:start position:0% +evaluator you run it except it stashes +away these operations instead of + + align:start position:0% +away these operations instead of + + + align:start position:0% +away these operations instead of +actually executing them well that's not + + align:start position:0% +actually executing them well that's not + + + align:start position:0% +actually executing them well that's not +that's not quite true there's there's + + align:start position:0% +that's not quite true there's there's + + + align:start position:0% +that's not quite true there's there's +only one one little lie in that what you + + align:start position:0% +only one one little lie in that what you + + + align:start position:0% +only one one little lie in that what you +have to worry about is if you have a + + align:start position:0% +have to worry about is if you have a + + + align:start position:0% +have to worry about is if you have a +predicate and if you have some kind of + + align:start position:0% +predicate and if you have some kind of + + + align:start position:0% +predicate and if you have some kind of +test you want to do obviously at the + + align:start position:0% +test you want to do obviously at the + + + align:start position:0% +test you want to do obviously at the +point when you're compiling it you don't + + align:start position:0% +point when you're compiling it you don't + + + align:start position:0% +point when you're compiling it you don't +know which branch of these of a + + align:start position:0% +know which branch of these of a + + + align:start position:0% +know which branch of these of a +conditional like this you're going to do + + align:start position:0% +conditional like this you're going to do + + + align:start position:0% +conditional like this you're going to do +right so you can't say which one the + + align:start position:0% +right so you can't say which one the + + + align:start position:0% +right so you can't say which one the +evaluator would have done so what you do + + align:start position:0% +evaluator would have done so what you do + + + align:start position:0% +evaluator would have done so what you do +there is is very simple you compile both + + align:start position:0% +there is is very simple you compile both + + + align:start position:0% +there is is very simple you compile both +branches so you compile the structure + + align:start position:0% +branches so you compile the structure + + + align:start position:0% +branches so you compile the structure +that looks like this that will compile + + align:start position:0% +that looks like this that will compile + + + align:start position:0% +that looks like this that will compile +into something that says the code the + + align:start position:0% +into something that says the code the + + + align:start position:0% +into something that says the code the +code for PE and it puts its result and + + align:start position:0% +code for PE and it puts its result and + + + align:start position:0% +code for PE and it puts its result and +say that the AL register so you walk the + + align:start position:0% +say that the AL register so you walk the + + + align:start position:0% +say that the AL register so you walk the +interpreter over the predicate and make + + align:start position:0% +interpreter over the predicate and make + + + align:start position:0% +interpreter over the predicate and make +sure that the result would go into the + + align:start position:0% +sure that the result would go into the + + + align:start position:0% +sure that the result would go into the +Val register and then you compile an + + align:start position:0% +Val register and then you compile an + + + align:start position:0% +Val register and then you compile an +instruction that says branch if if del + + align:start position:0% +instruction that says branch if if del + + + align:start position:0% +instruction that says branch if if del +is true to a place we'll call label one + + align:start position:0% + + + + align:start position:0% + +then we will put the code for B so walk + + align:start position:0% +then we will put the code for B so walk + + + align:start position:0% +then we will put the code for B so walk +the interpreter walk the interpreter + + align:start position:0% +the interpreter walk the interpreter + + + align:start position:0% +the interpreter walk the interpreter +over B and then go to put in an + + align:start position:0% +over B and then go to put in an + + + align:start position:0% +over B and then go to put in an +instruction that says go to the next + + align:start position:0% +instruction that says go to the next + + + align:start position:0% +instruction that says go to the next +thing whatever whatever was supposed to + + align:start position:0% +thing whatever whatever was supposed to + + + align:start position:0% +thing whatever whatever was supposed to +happen after this thing was done you put + + align:start position:0% +happen after this thing was done you put + + + align:start position:0% +happen after this thing was done you put +in that instruction and here you put + + align:start position:0% +in that instruction and here you put + + + align:start position:0% +in that instruction and here you put +label one + + align:start position:0% + + + + align:start position:0% + +and here you put the code for a and you + + align:start position:0% +and here you put the code for a and you + + + align:start position:0% +and here you put the code for a and you +put go to next thing so that's how you + + align:start position:0% +put go to next thing so that's how you + + + align:start position:0% +put go to next thing so that's how you +treat it conditional you generate a + + align:start position:0% +treat it conditional you generate a + + + align:start position:0% +treat it conditional you generate a +little block like that and other than + + align:start position:0% +little block like that and other than + + + align:start position:0% +little block like that and other than +that this zeroth-order compiler is the + + align:start position:0% +that this zeroth-order compiler is the + + + align:start position:0% +that this zeroth-order compiler is the +same as the evaluator + + align:start position:0% +same as the evaluator + + + align:start position:0% +same as the evaluator +it's just stashing away the instructions + + align:start position:0% +it's just stashing away the instructions + + + align:start position:0% +it's just stashing away the instructions +instead of executing them that seems + + align:start position:0% +instead of executing them that seems + + + align:start position:0% +instead of executing them that seems +pretty simple but we've gained something + + align:start position:0% +pretty simple but we've gained something + + + align:start position:0% +pretty simple but we've gained something +by that C already that's going to be + + align:start position:0% +by that C already that's going to be + + + align:start position:0% +by that C already that's going to be +more efficient than the evaluator + + align:start position:0% +more efficient than the evaluator + + + align:start position:0% +more efficient than the evaluator +because if you watch the evaluator run + + align:start position:0% +because if you watch the evaluator run + + + align:start position:0% +because if you watch the evaluator run +it's not only generating the register + + align:start position:0% +it's not only generating the register + + + align:start position:0% +it's not only generating the register +operations we wrote down it's also doing + + align:start position:0% +operations we wrote down it's also doing + + + align:start position:0% +operations we wrote down it's also doing +things to decide which ones to generate + + align:start position:0% +things to decide which ones to generate + + + align:start position:0% +things to decide which ones to generate +so the very first thing it does say here + + align:start position:0% +so the very first thing it does say here + + + align:start position:0% +so the very first thing it does say here +for instance is go do some tests and + + align:start position:0% +for instance is go do some tests and + + + align:start position:0% +for instance is go do some tests and +decide that this is an application and + + align:start position:0% +decide that this is an application and + + + align:start position:0% +decide that this is an application and +then branch off to the place that that + + align:start position:0% +then branch off to the place that that + + + align:start position:0% +then branch off to the place that that +handles applications in other words what + + align:start position:0% +handles applications in other words what + + + align:start position:0% +handles applications in other words what +the evaluator is doing is simultaneously + + align:start position:0% +the evaluator is doing is simultaneously + + + align:start position:0% +the evaluator is doing is simultaneously +analyzing the code to see what to do and + + align:start position:0% +analyzing the code to see what to do and + + + align:start position:0% +analyzing the code to see what to do and +running these operations and when you if + + align:start position:0% +running these operations and when you if + + + align:start position:0% +running these operations and when you if +you run the amount the evaluator a + + align:start position:0% +you run the amount the evaluator a + + + align:start position:0% +you run the amount the evaluator a +million times that analysis phase + + align:start position:0% +million times that analysis phase + + + align:start position:0% +million times that analysis phase +happens a million times whereas in the + + align:start position:0% +happens a million times whereas in the + + + align:start position:0% +happens a million times whereas in the +compiler it's happened once and then you + + align:start position:0% +compiler it's happened once and then you + + + align:start position:0% +compiler it's happened once and then you +just have the register operations + + align:start position:0% +just have the register operations + + + align:start position:0% +just have the register operations +themselves okay that's a zeroth-order + + align:start position:0% +themselves okay that's a zeroth-order + + + align:start position:0% +themselves okay that's a zeroth-order +compiler but it is a wretched wretched + + align:start position:0% +compiler but it is a wretched wretched + + + align:start position:0% +compiler but it is a wretched wretched +compiler it's really dumb + + align:start position:0% +compiler it's really dumb + + + align:start position:0% +compiler it's really dumb +all right let's let's go back and and + + align:start position:0% +all right let's let's go back and and + + + align:start position:0% +all right let's let's go back and and +look at this overhead so you look at + + align:start position:0% +look at this overhead so you look at + + + align:start position:0% +look at this overhead so you look at +look at some of the the operations this + + align:start position:0% +look at some of the the operations this + + + align:start position:0% +look at some of the the operations this +thing is doing we're supposed to be + + align:start position:0% + + + + align:start position:0% + +looking at the operations and + + align:start position:0% +looking at the operations and + + + align:start position:0% +looking at the operations and +interpreting f of X now look here what + + align:start position:0% +interpreting f of X now look here what + + + align:start position:0% +interpreting f of X now look here what +it's doing for example here it assigns + + align:start position:0% +it's doing for example here it assigns + + + align:start position:0% +it's doing for example here it assigns +to X the operator in fetch of X but see + + align:start position:0% +to X the operator in fetch of X but see + + + align:start position:0% +to X the operator in fetch of X but see +there's no reason to do that because + + align:start position:0% +there's no reason to do that because + + + align:start position:0% +there's no reason to do that because +this is the compiler knows that the + + align:start position:0% +this is the compiler knows that the + + + align:start position:0% +this is the compiler knows that the +operator the operator of fetch of X does + + align:start position:0% +operator the operator of fetch of X does + + + align:start position:0% +operator the operator of fetch of X does +F is f right here so there's no reason + + align:start position:0% +F is f right here so there's no reason + + + align:start position:0% +F is f right here so there's no reason +why this instruction should + + align:start position:0% +why this instruction should + + + align:start position:0% +why this instruction should +say that it should say well assigned to + + align:start position:0% +say that it should say well assigned to + + + align:start position:0% +say that it should say well assigned to +X F or in fact you don't need expert all + + align:start position:0% +X F or in fact you don't need expert all + + + align:start position:0% +X F or in fact you don't need expert all +there's no reason that you'd have the + + align:start position:0% +there's no reason that you'd have the + + + align:start position:0% +there's no reason that you'd have the +expert all what what did X get used for + + align:start position:0% +expert all what what did X get used for + + + align:start position:0% +expert all what what did X get used for +well if we come down here we're going to + + align:start position:0% +well if we come down here we're going to + + + align:start position:0% +well if we come down here we're going to +assign to Val look up the stuff in X in + + align:start position:0% +assign to Val look up the stuff in X in + + + align:start position:0% +assign to Val look up the stuff in X in +the environment so what we really should + + align:start position:0% +the environment so what we really should + + + align:start position:0% +the environment so what we really should +do is get rid of the X register + + align:start position:0% +do is get rid of the X register + + + align:start position:0% +do is get rid of the X register +altogether and just change this + + align:start position:0% +altogether and just change this + + + align:start position:0% +altogether and just change this +instruction to say assigned to Val look + + align:start position:0% +instruction to say assigned to Val look + + + align:start position:0% +instruction to say assigned to Val look +up the variable value of the symbol F in + + align:start position:0% +up the variable value of the symbol F in + + + align:start position:0% +up the variable value of the symbol F in +the environment + + align:start position:0% + + + + align:start position:0% + +similarly back up here we don't need + + align:start position:0% +similarly back up here we don't need + + + align:start position:0% +similarly back up here we don't need +unev at all because we know what the + + align:start position:0% +unev at all because we know what the + + + align:start position:0% +unev at all because we know what the +operands efetch of the x bar for this + + align:start position:0% +operands efetch of the x bar for this + + + align:start position:0% +operands efetch of the x bar for this +piece of code it's the lits the list X + + align:start position:0% +piece of code it's the lits the list X + + + align:start position:0% +piece of code it's the lits the list X +so in some sense you don't want unev and + + align:start position:0% +so in some sense you don't want unev and + + + align:start position:0% +so in some sense you don't want unev and +expert or see what they really are in + + align:start position:0% +expert or see what they really are in + + + align:start position:0% +expert or see what they really are in +some sense those aren't registers of the + + align:start position:0% +some sense those aren't registers of the + + + align:start position:0% +some sense those aren't registers of the +actual machine that's supposed to run + + align:start position:0% +actual machine that's supposed to run + + + align:start position:0% +actual machine that's supposed to run +those are registers that have to do with + + align:start position:0% +those are registers that have to do with + + + align:start position:0% +those are registers that have to do with +arranging the thing that can simulate + + align:start position:0% +arranging the thing that can simulate + + + align:start position:0% +arranging the thing that can simulate +that machine so they're always going to + + align:start position:0% +that machine so they're always going to + + + align:start position:0% +that machine so they're always going to +hold expressions which from the + + align:start position:0% +hold expressions which from the + + + align:start position:0% +hold expressions which from the +compilers point of view are just + + align:start position:0% +compilers point of view are just + + + align:start position:0% +compilers point of view are just +constants so can be put right into the + + align:start position:0% +constants so can be put right into the + + + align:start position:0% +constants so can be put right into the +code so you can forget about all the + + align:start position:0% +code so you can forget about all the + + + align:start position:0% +code so you can forget about all the +operations worrying about exponent and + + align:start position:0% +operations worrying about exponent and + + + align:start position:0% +operations worrying about exponent and +just use those constants similarly again + + align:start position:0% +just use those constants similarly again + + + align:start position:0% +just use those constants similarly again +if we go go back and look here there are + + align:start position:0% +if we go go back and look here there are + + + align:start position:0% +if we go go back and look here there are +things like a sign to continue eval args + + align:start position:0% +things like a sign to continue eval args + + + align:start position:0% +things like a sign to continue eval args +now that has nothing to do with anything + + align:start position:0% +now that has nothing to do with anything + + + align:start position:0% +now that has nothing to do with anything +that was just the evaluator keeping + + align:start position:0% +that was just the evaluator keeping + + + align:start position:0% +that was just the evaluator keeping +track of where it should go next right + + align:start position:0% +track of where it should go next right + + + align:start position:0% +track of where it should go next right +to evaluate the arguments and sumit in + + align:start position:0% +to evaluate the arguments and sumit in + + + align:start position:0% +to evaluate the arguments and sumit in +some application but of course that's + + align:start position:0% +some application but of course that's + + + align:start position:0% +some application but of course that's +irrelevant to the compiler because you + + align:start position:0% +irrelevant to the compiler because you + + + align:start position:0% +irrelevant to the compiler because you +the analysis phase will have already + + align:start position:0% +the analysis phase will have already + + + align:start position:0% +the analysis phase will have already +done that ok so this is completely + + align:start position:0% +done that ok so this is completely + + + align:start position:0% +done that ok so this is completely +irrelevant so a lot of these these + + align:start position:0% +irrelevant so a lot of these these + + + align:start position:0% +irrelevant so a lot of these these +assignments to continue have not - to do + + align:start position:0% +assignments to continue have not - to do + + + align:start position:0% +assignments to continue have not - to do +where the the running machine is + + align:start position:0% +where the the running machine is + + + align:start position:0% +where the the running machine is +supposed to continue in keeping track of + + align:start position:0% +supposed to continue in keeping track of + + + align:start position:0% +supposed to continue in keeping track of +its day it has to do with where the + + align:start position:0% +its day it has to do with where the + + + align:start position:0% +its day it has to do with where the +evaluator analysis should continue and + + align:start position:0% +evaluator analysis should continue and + + + align:start position:0% +evaluator analysis should continue and +those are completely irrelevant so we + + align:start position:0% +those are completely irrelevant so we + + + align:start position:0% +those are completely irrelevant so we +can get rid of them + + align:start position:0% + + + + align:start position:0% + +okay all right okay + + align:start position:0% + + + + align:start position:0% + +okay well if we if we simply do that + + align:start position:0% +okay well if we if we simply do that + + + align:start position:0% +okay well if we if we simply do that +make those kinds of optimizations get + + align:start position:0% +make those kinds of optimizations get + + + align:start position:0% +make those kinds of optimizations get +rid of right get rid of worrying about + + align:start position:0% +rid of right get rid of worrying about + + + align:start position:0% +rid of right get rid of worrying about +exponet rid of these irrelevant register + + align:start position:0% +exponet rid of these irrelevant register + + + align:start position:0% +exponet rid of these irrelevant register +assignments to continue then we can take + + align:start position:0% +assignments to continue then we can take + + + align:start position:0% +assignments to continue then we can take +this literal code these sort of nineteen + + align:start position:0% +this literal code these sort of nineteen + + + align:start position:0% +this literal code these sort of nineteen +instructions that the that the evaluator + + align:start position:0% +instructions that the that the evaluator + + + align:start position:0% +instructions that the that the evaluator +would have done and then replace them + + align:start position:0% +would have done and then replace them + + + align:start position:0% +would have done and then replace them +let's look at the at the slide you can + + align:start position:0% +let's look at the at the slide you can + + + align:start position:0% +let's look at the at the slide you can +place them by we get rid of about half + + align:start position:0% +place them by we get rid of about half + + + align:start position:0% +place them by we get rid of about half +of them right and again this is just + + align:start position:0% +of them right and again this is just + + + align:start position:0% +of them right and again this is just +sort of filtering what the evaluator + + align:start position:0% +sort of filtering what the evaluator + + + align:start position:0% +sort of filtering what the evaluator +would have done by getting rid of the + + align:start position:0% +would have done by getting rid of the + + + align:start position:0% +would have done by getting rid of the +irrelevant stuff and you see for + + align:start position:0% +irrelevant stuff and you see for + + + align:start position:0% +irrelevant stuff and you see for +instance here we where the evaluator + + align:start position:0% +instance here we where the evaluator + + + align:start position:0% +instance here we where the evaluator +said assigned Val lookup variable value + + align:start position:0% +said assigned Val lookup variable value + + + align:start position:0% +said assigned Val lookup variable value +fetch of X pier we have put in the + + align:start position:0% +fetch of X pier we have put in the + + + align:start position:0% +fetch of X pier we have put in the +constant F here we've put in the + + align:start position:0% +constant F here we've put in the + + + align:start position:0% +constant F here we've put in the +constant X so there's a there's a little + + align:start position:0% +constant X so there's a there's a little + + + align:start position:0% +constant X so there's a there's a little +better compiler it's a it's still pretty + + align:start position:0% +better compiler it's a it's still pretty + + + align:start position:0% +better compiler it's a it's still pretty +dumb it's still doing a lot of dumb + + align:start position:0% +dumb it's still doing a lot of dumb + + + align:start position:0% +dumb it's still doing a lot of dumb +things again if we go look at the slide + + align:start position:0% +things again if we go look at the slide + + + align:start position:0% +things again if we go look at the slide +again look the very beginning here we + + align:start position:0% +again look the very beginning here we + + + align:start position:0% +again look the very beginning here we +see a save the environment assign + + align:start position:0% +see a save the environment assign + + + align:start position:0% +see a save the environment assign +something to the Vale register and + + align:start position:0% +something to the Vale register and + + + align:start position:0% +something to the Vale register and +restore the environment where'd that + + align:start position:0% +restore the environment where'd that + + + align:start position:0% +restore the environment where'd that +come from that came from the evaluator + + align:start position:0% +come from that came from the evaluator + + + align:start position:0% +come from that came from the evaluator +back here saying oh I'm in the middle of + + align:start position:0% +back here saying oh I'm in the middle of + + + align:start position:0% +back here saying oh I'm in the middle of +evaluating an application so I'm going + + align:start position:0% +evaluating an application so I'm going + + + align:start position:0% +evaluating an application so I'm going +to recursively call eval dispatch so I + + align:start position:0% +to recursively call eval dispatch so I + + + align:start position:0% +to recursively call eval dispatch so I +better save the thing I'm going to need + + align:start position:0% +better save the thing I'm going to need + + + align:start position:0% +better save the thing I'm going to need +later which is the environment this was + + align:start position:0% +later which is the environment this was + + + align:start position:0% +later which is the environment this was +the result of recursively calling eval + + align:start position:0% +the result of recursively calling eval + + + align:start position:0% +the result of recursively calling eval +dispatch it was evaluating the symbol F + + align:start position:0% +dispatch it was evaluating the symbol F + + + align:start position:0% +dispatch it was evaluating the symbol F +in that case and it came back from + + align:start position:0% +in that case and it came back from + + + align:start position:0% +in that case and it came back from +eval-dispatch restored the environment + + align:start position:0% +eval-dispatch restored the environment + + + align:start position:0% +eval-dispatch restored the environment +but in fact the actual thing it ended up + + align:start position:0% +but in fact the actual thing it ended up + + + align:start position:0% +but in fact the actual thing it ended up +doing in the evaluation is not going to + + align:start position:0% +doing in the evaluation is not going to + + + align:start position:0% +doing in the evaluation is not going to +hurt the environment at all so there's + + align:start position:0% +hurt the environment at all so there's + + + align:start position:0% +hurt the environment at all so there's +no reason to be saving the environment + + align:start position:0% +no reason to be saving the environment + + + align:start position:0% +no reason to be saving the environment +and restoring the environment here but + + align:start position:0% +and restoring the environment here but + + + align:start position:0% +and restoring the environment here but +similarly here I'm saving the argument + + align:start position:0% +similarly here I'm saving the argument + + + align:start position:0% +similarly here I'm saving the argument +list that's a piece of the argument + + align:start position:0% +list that's a piece of the argument + + + align:start position:0% +list that's a piece of the argument +evaluation live saving the argument + + align:start position:0% +evaluation live saving the argument + + + align:start position:0% +evaluation live saving the argument +and here you restore it but the actual + + align:start position:0% +and here you restore it but the actual + + + align:start position:0% +and here you restore it but the actual +thing that you ended up doing didn't + + align:start position:0% +thing that you ended up doing didn't + + + align:start position:0% +thing that you ended up doing didn't +trash the argument list so there was no + + align:start position:0% +trash the argument list so there was no + + + align:start position:0% +trash the argument list so there was no +reason to save it all right so another + + align:start position:0% +reason to save it all right so another + + + align:start position:0% +reason to save it all right so another +way to but another way to say that is + + align:start position:0% +way to but another way to say that is + + + align:start position:0% +way to but another way to say that is +that the the evaluator has to be + + align:start position:0% +that the the evaluator has to be + + + align:start position:0% +that the the evaluator has to be +maximally pessimistic because as far + + align:start position:0% +maximally pessimistic because as far + + + align:start position:0% +maximally pessimistic because as far +from its point of view it's just going + + align:start position:0% +from its point of view it's just going + + + align:start position:0% +from its point of view it's just going +off to evaluate something so we'd better + + align:start position:0% +off to evaluate something so we'd better + + + align:start position:0% +off to evaluate something so we'd better +save what its gonna need later but once + + align:start position:0% +save what its gonna need later but once + + + align:start position:0% +save what its gonna need later but once +you've done the analysis the compiler is + + align:start position:0% +you've done the analysis the compiler is + + + align:start position:0% +you've done the analysis the compiler is +in a position to say well what actually + + align:start position:0% +in a position to say well what actually + + + align:start position:0% +in a position to say well what actually +did I need to save and doesn't need to + + align:start position:0% +did I need to save and doesn't need to + + + align:start position:0% +did I need to save and doesn't need to +do anything need to be as careful as the + + align:start position:0% +do anything need to be as careful as the + + + align:start position:0% +do anything need to be as careful as the +SD evaluator because it knows what it + + align:start position:0% +SD evaluator because it knows what it + + + align:start position:0% +SD evaluator because it knows what it +actually needs well in case if we do + + align:start position:0% +actually needs well in case if we do + + + align:start position:0% +actually needs well in case if we do +that and eliminate all those redundant + + align:start position:0% +that and eliminate all those redundant + + + align:start position:0% +that and eliminate all those redundant +saves and restores then we can get it + + align:start position:0% +saves and restores then we can get it + + + align:start position:0% +saves and restores then we can get it +down to this you see they're actually + + align:start position:0% +down to this you see they're actually + + + align:start position:0% +down to this you see they're actually +only three reasons only three + + align:start position:0% +only three reasons only three + + + align:start position:0% +only three reasons only three +instructions that we actually need down + + align:start position:0% +instructions that we actually need down + + + align:start position:0% +instructions that we actually need down +from the initial 11 or so or the initial + + align:start position:0% +from the initial 11 or so or the initial + + + align:start position:0% +from the initial 11 or so or the initial +the initial 20 or so in the original one + + align:start position:0% +the initial 20 or so in the original one + + + align:start position:0% +the initial 20 or so in the original one +okay and that's just saying of those + + align:start position:0% +okay and that's just saying of those + + + align:start position:0% +okay and that's just saying of those +register operations which ones did we + + align:start position:0% +register operations which ones did we + + + align:start position:0% +register operations which ones did we +actually need let me let me just sort of + + align:start position:0% +actually need let me let me just sort of + + + align:start position:0% +actually need let me let me just sort of +summarize that in another way just to + + align:start position:0% +summarize that in another way just to + + + align:start position:0% +summarize that in another way just to +show you in a little better picture + + align:start position:0% + + + + align:start position:0% + +here's a picture of starting this is + + align:start position:0% +here's a picture of starting this is + + + align:start position:0% +here's a picture of starting this is +looking at all the saves and restores + + align:start position:0% + + + + align:start position:0% + +right so here's the expression f of X + + align:start position:0% +right so here's the expression f of X + + + align:start position:0% +right so here's the expression f of X +and then this traces through on the + + align:start position:0% +and then this traces through on the + + + align:start position:0% +and then this traces through on the +bottom here the various places in the + + align:start position:0% +bottom here the various places in the + + + align:start position:0% +bottom here the various places in the +evaluator that were passed when the + + align:start position:0% +evaluator that were passed when the + + + align:start position:0% +evaluator that were passed when the +evaluation happened and then here here + + align:start position:0% +evaluation happened and then here here + + + align:start position:0% +evaluation happened and then here here +you see arrows arrow down means the + + align:start position:0% +you see arrows arrow down means the + + + align:start position:0% +you see arrows arrow down means the +register saved so the first thing that + + align:start position:0% +register saved so the first thing that + + + align:start position:0% +register saved so the first thing that +happened is the environment got saved + + align:start position:0% +happened is the environment got saved + + + align:start position:0% +happened is the environment got saved +and over here the environment got + + align:start position:0% +and over here the environment got + + + align:start position:0% +and over here the environment got +restored and these and so they're all + + align:start position:0% +restored and these and so they're all + + + align:start position:0% +restored and these and so they're all +the pairs of stack operations now if you + + align:start position:0% +the pairs of stack operations now if you + + + align:start position:0% +the pairs of stack operations now if you +go ahead and say well let's let's + + align:start position:0% +go ahead and say well let's let's + + + align:start position:0% +go ahead and say well let's let's +remember that we don't that unev for + + align:start position:0% +remember that we don't that unev for + + + align:start position:0% +remember that we don't that unev for +instance is a completely useless + + align:start position:0% +instance is a completely useless + + + align:start position:0% +instance is a completely useless +register + + align:start position:0% + + + + align:start position:0% + +and if we use the constant structure of + + align:start position:0% +and if we use the constant structure of + + + align:start position:0% +and if we use the constant structure of +the code well we don't need we don't + + align:start position:0% +the code well we don't need we don't + + + align:start position:0% +the code well we don't need we don't +need to save on if we don't need unearth + + align:start position:0% +need to save on if we don't need unearth + + + align:start position:0% +need to save on if we don't need unearth +at all and then depending on how we set + + align:start position:0% +at all and then depending on how we set + + + align:start position:0% +at all and then depending on how we set +up the discipline of the of calling of + + align:start position:0% +up the discipline of the of calling of + + + align:start position:0% +up the discipline of the of calling of +crawling other things that apply we may + + align:start position:0% +crawling other things that apply we may + + + align:start position:0% +crawling other things that apply we may +or may not need to save continue that's + + align:start position:0% +or may not need to save continue that's + + + align:start position:0% +or may not need to save continue that's +the first step I did and then we can + + align:start position:0% +the first step I did and then we can + + + align:start position:0% +the first step I did and then we can +look and see what's actually what's + + align:start position:0% +look and see what's actually what's + + + align:start position:0% +look and see what's actually what's +actually needed see we we don't didn't + + align:start position:0% +actually needed see we we don't didn't + + + align:start position:0% +actually needed see we we don't didn't +really need to sit in or cross + + align:start position:0% +really need to sit in or cross + + + align:start position:0% +really need to sit in or cross +evaluating F because it wouldn't it + + align:start position:0% +evaluating F because it wouldn't it + + + align:start position:0% +evaluating F because it wouldn't it +wouldn't trash it so if we take + + align:start position:0% +wouldn't trash it so if we take + + + align:start position:0% +wouldn't trash it so if we take +advantage of that then see the + + align:start position:0% +advantage of that then see the + + + align:start position:0% +advantage of that then see the +evaluation of F here doesn't really need + + align:start position:0% +evaluation of F here doesn't really need + + + align:start position:0% +evaluation of F here doesn't really need +to worry about about hurting end and + + align:start position:0% +to worry about about hurting end and + + + align:start position:0% +to worry about about hurting end and +similarly the evaluation of X here the + + align:start position:0% +similarly the evaluation of X here the + + + align:start position:0% +similarly the evaluation of X here the +when the evaluator did that it said oh + + align:start position:0% +when the evaluator did that it said oh + + + align:start position:0% +when the evaluator did that it said oh +I'd better preserve the function + + align:start position:0% +I'd better preserve the function + + + align:start position:0% +I'd better preserve the function +register around that because I might + + align:start position:0% +register around that because I might + + + align:start position:0% +register around that because I might +need it later and I better preserve the + + align:start position:0% +need it later and I better preserve the + + + align:start position:0% +need it later and I better preserve the +argument list right whereas the compiler + + align:start position:0% +argument list right whereas the compiler + + + align:start position:0% +argument list right whereas the compiler +is now in a position to know what we + + align:start position:0% +is now in a position to know what we + + + align:start position:0% +is now in a position to know what we +didn't really need to save do those + + align:start position:0% +didn't really need to save do those + + + align:start position:0% +didn't really need to save do those +saves and restores so in fact all of the + + align:start position:0% +saves and restores so in fact all of the + + + align:start position:0% +saves and restores so in fact all of the +stack operations done by the evaluator + + align:start position:0% +stack operations done by the evaluator + + + align:start position:0% +stack operations done by the evaluator +turned out to be unnecessary or overly + + align:start position:0% +turned out to be unnecessary or overly + + + align:start position:0% +turned out to be unnecessary or overly +pessimistic and the compilers in a + + align:start position:0% +pessimistic and the compilers in a + + + align:start position:0% +pessimistic and the compilers in a +position to know that okay that's the + + align:start position:0% +position to know that okay that's the + + + align:start position:0% +position to know that okay that's the +basic idea that we take the evaluator we + + align:start position:0% +basic idea that we take the evaluator we + + + align:start position:0% +basic idea that we take the evaluator we +eliminate the things that you don't need + + align:start position:0% +eliminate the things that you don't need + + + align:start position:0% +eliminate the things that you don't need +that in some sense have nothing to do + + align:start position:0% +that in some sense have nothing to do + + + align:start position:0% +that in some sense have nothing to do +with the compiler at all just the + + align:start position:0% +with the compiler at all just the + + + align:start position:0% +with the compiler at all just the +evaluator and then you see which stack + + align:start position:0% +evaluator and then you see which stack + + + align:start position:0% +evaluator and then you see which stack +operations were unnecessary and that's + + align:start position:0% +operations were unnecessary and that's + + + align:start position:0% +operations were unnecessary and that's +the basic structure of the the compiler + + align:start position:0% +the basic structure of the the compiler + + + align:start position:0% +the basic structure of the the compiler +that's that's described in the book let + + align:start position:0% +that's that's described in the book let + + + align:start position:0% +that's that's described in the book let +me just show you how that examples a + + align:start position:0% +me just show you how that examples a + + + align:start position:0% +me just show you how that examples a +little bit too simple to see how how you + + align:start position:0% +little bit too simple to see how how you + + + align:start position:0% +little bit too simple to see how how you +actually save a lot let's look at a + + align:start position:0% +actually save a lot let's look at a + + + align:start position:0% +actually save a lot let's look at a +little bit more complicated expression + + align:start position:0% +little bit more complicated expression + + + align:start position:0% +little bit more complicated expression +that F of G of X m1 and I'm not going to + + align:start position:0% +that F of G of X m1 and I'm not going to + + + align:start position:0% +that F of G of X m1 and I'm not going to +go through all the code there's a + + align:start position:0% +go through all the code there's a + + + align:start position:0% +go through all the code there's a +there's a fair pile of it I think there + + align:start position:0% +there's a fair pile of it I think there + + + align:start position:0% +there's a fair pile of it I think there +there's something like 16 pairs of + + align:start position:0% +there's something like 16 pairs of + + + align:start position:0% +there's something like 16 pairs of +registers saves and restores as the + + align:start position:0% +registers saves and restores as the + + + align:start position:0% +registers saves and restores as the +evaluator walks through that here's a + + align:start position:0% +evaluator walks through that here's a + + + align:start position:0% +evaluator walks through that here's a +diagram of them + + align:start position:0% +diagram of them + + + align:start position:0% +diagram of them +right so you see what's going on you + + align:start position:0% +right so you see what's going on you + + + align:start position:0% +right so you see what's going on you +start out by the evaluator says oh I'm + + align:start position:0% +start out by the evaluator says oh I'm + + + align:start position:0% +start out by the evaluator says oh I'm +about to do an application I'll preserve + + align:start position:0% +about to do an application I'll preserve + + + align:start position:0% +about to do an application I'll preserve +the environment I'll restore it here + + align:start position:0% +the environment I'll restore it here + + + align:start position:0% +the environment I'll restore it here +then I'm about to do the first operand + + align:start position:0% + + + + align:start position:0% + +here it recursively goes to the to the + + align:start position:0% +here it recursively goes to the to the + + + align:start position:0% +here it recursively goes to the to the +evaluator the evaluator says oh this is + + align:start position:0% +evaluator the evaluator says oh this is + + + align:start position:0% +evaluator the evaluator says oh this is +an application I'll save the environment + + align:start position:0% +an application I'll save the environment + + + align:start position:0% +an application I'll save the environment +do the operator of that combination + + align:start position:0% +do the operator of that combination + + + align:start position:0% +do the operator of that combination +restore it here to say this restore + + align:start position:0% +restore it here to say this restore + + + align:start position:0% +restore it here to say this restore +matches that save right and so on + + align:start position:0% +matches that save right and so on + + + align:start position:0% +matches that save right and so on +there's unev here which turns out to be + + align:start position:0% +there's unev here which turns out to be + + + align:start position:0% +there's unev here which turns out to be +completely unnecessary continues getting + + align:start position:0% +completely unnecessary continues getting + + + align:start position:0% +completely unnecessary continues getting +bumped around here the function register + + align:start position:0% +bumped around here the function register + + + align:start position:0% +bumped around here the function register +is getting getting saved across the + + align:start position:0% +is getting getting saved across the + + + align:start position:0% +is getting getting saved across the +first operand across the operands that + + align:start position:0% +first operand across the operands that + + + align:start position:0% +first operand across the operands that +all sorts of things are going on but if + + align:start position:0% +all sorts of things are going on but if + + + align:start position:0% +all sorts of things are going on but if +you say well what what did those really + + align:start position:0% +you say well what what did those really + + + align:start position:0% +you say well what what did those really +where the business of the compiler as + + align:start position:0% +where the business of the compiler as + + + align:start position:0% +where the business of the compiler as +opposed to the evaluator you get rid of + + align:start position:0% +opposed to the evaluator you get rid of + + + align:start position:0% +opposed to the evaluator you get rid of +a whole bunch and then on top of that if + + align:start position:0% +a whole bunch and then on top of that if + + + align:start position:0% +a whole bunch and then on top of that if +you say things like the evaluation of + + align:start position:0% +you say things like the evaluation of + + + align:start position:0% +you say things like the evaluation of +the F doesn't hurt the environment + + align:start position:0% +the F doesn't hurt the environment + + + align:start position:0% +the F doesn't hurt the environment +register or simply looking up the symbol + + align:start position:0% +register or simply looking up the symbol + + + align:start position:0% +register or simply looking up the symbol +X you don't have to protect the function + + align:start position:0% +X you don't have to protect the function + + + align:start position:0% +X you don't have to protect the function +register against that all right so you + + align:start position:0% +register against that all right so you + + + align:start position:0% +register against that all right so you +come down to just a couple of a couple + + align:start position:0% +come down to just a couple of a couple + + + align:start position:0% +come down to just a couple of a couple +of pairs here and still you can do a + + align:start position:0% +of pairs here and still you can do a + + + align:start position:0% +of pairs here and still you can do a +little bitter look what's going on here + + align:start position:0% +little bitter look what's going on here + + + align:start position:0% +little bitter look what's going on here +with the environment register the + + align:start position:0% +with the environment register the + + + align:start position:0% +with the environment register the +environment register comes along and + + align:start position:0% +environment register comes along and + + + align:start position:0% +environment register comes along and +says oh here's a combination this + + align:start position:0% +says oh here's a combination this + + + align:start position:0% +says oh here's a combination this +evaluator by the way doesn't know + + align:start position:0% +evaluator by the way doesn't know + + + align:start position:0% +evaluator by the way doesn't know +anything about G so here it says so it + + align:start position:0% +anything about G so here it says so it + + + align:start position:0% +anything about G so here it says so it +says I better save the environment + + align:start position:0% +says I better save the environment + + + align:start position:0% +says I better save the environment +register because evaluating G might be + + align:start position:0% +register because evaluating G might be + + + align:start position:0% +register because evaluating G might be +some arbitrary piece of code that would + + align:start position:0% +some arbitrary piece of code that would + + + align:start position:0% +some arbitrary piece of code that would +trash it and I'm going to need it later + + align:start position:0% +trash it and I'm going to need it later + + + align:start position:0% +trash it and I'm going to need it later +after this argument for doing the second + + align:start position:0% +after this argument for doing the second + + + align:start position:0% +after this argument for doing the second +argument so that's why this one didn't + + align:start position:0% +argument so that's why this one didn't + + + align:start position:0% +argument so that's why this one didn't +go away because the compiler made no + + align:start position:0% +go away because the compiler made no + + + align:start position:0% +go away because the compiler made no +assumptions about what G would do on the + + align:start position:0% +assumptions about what G would do on the + + + align:start position:0% +assumptions about what G would do on the +other hand if you look at the what the + + align:start position:0% +other hand if you look at the what the + + + align:start position:0% +other hand if you look at the what the +second argument is that's just looking + + align:start position:0% +second argument is that's just looking + + + align:start position:0% +second argument is that's just looking +up one that doesn't need this + + align:start position:0% +up one that doesn't need this + + + align:start position:0% +up one that doesn't need this +environment register so there's no + + align:start position:0% +environment register so there's no + + + align:start position:0% +environment register so there's no +reason to save its own + + align:start position:0% +reason to save its own + + + align:start position:0% +reason to save its own +you can get rid of that one too and from + + align:start position:0% +you can get rid of that one too and from + + + align:start position:0% +you can get rid of that one too and from +this whole pile of register operations + + align:start position:0% +this whole pile of register operations + + + align:start position:0% +this whole pile of register operations +if you simply do a little bit of + + align:start position:0% +if you simply do a little bit of + + + align:start position:0% +if you simply do a little bit of +reasoning like that you get down to I + + align:start position:0% +reasoning like that you get down to I + + + align:start position:0% +reasoning like that you get down to I +think just two pairs of saves and + + align:start position:0% +think just two pairs of saves and + + + align:start position:0% +think just two pairs of saves and +restores and those that could go away + + align:start position:0% +restores and those that could go away + + + align:start position:0% +restores and those that could go away +further if you if you knew something + + align:start position:0% +further if you if you knew something + + + align:start position:0% +further if you if you knew something +about G okay all right so again the + + align:start position:0% +about G okay all right so again the + + + align:start position:0% +about G okay all right so again the +general idea is that the reason the + + align:start position:0% +general idea is that the reason the + + + align:start position:0% +general idea is that the reason the +compiler can be better is that the + + align:start position:0% +compiler can be better is that the + + + align:start position:0% +compiler can be better is that the +interpreter doesn't know what it's about + + align:start position:0% +interpreter doesn't know what it's about + + + align:start position:0% +interpreter doesn't know what it's about +to encounter it has to be maximally + + align:start position:0% +to encounter it has to be maximally + + + align:start position:0% +to encounter it has to be maximally +pessimistic and saving things to protect + + align:start position:0% +pessimistic and saving things to protect + + + align:start position:0% +pessimistic and saving things to protect +itself the compiler only has to deal + + align:start position:0% +itself the compiler only has to deal + + + align:start position:0% +itself the compiler only has to deal +with it what actually had to be saved + + align:start position:0% +with it what actually had to be saved + + + align:start position:0% +with it what actually had to be saved +and there are two reasons that something + + align:start position:0% +and there are two reasons that something + + + align:start position:0% +and there are two reasons that something +might not have to be saved one is that + + align:start position:0% +might not have to be saved one is that + + + align:start position:0% +might not have to be saved one is that +what you're protecting it against in + + align:start position:0% +what you're protecting it against in + + + align:start position:0% +what you're protecting it against in +fact didn't trash the register like it + + align:start position:0% +fact didn't trash the register like it + + + align:start position:0% +fact didn't trash the register like it +was just a variable lookup and the other + + align:start position:0% +was just a variable lookup and the other + + + align:start position:0% +was just a variable lookup and the other +one is that the thing that you were + + align:start position:0% +one is that the thing that you were + + + align:start position:0% +one is that the thing that you were +saving it for might turn out not to + + align:start position:0% +saving it for might turn out not to + + + align:start position:0% +saving it for might turn out not to +actually need it so those are the two + + align:start position:0% +actually need it so those are the two + + + align:start position:0% +actually need it so those are the two +basic pieces of knowledge that the + + align:start position:0% +basic pieces of knowledge that the + + + align:start position:0% +basic pieces of knowledge that the +compiler can take advantage of in making + + align:start position:0% +compiler can take advantage of in making + + + align:start position:0% +compiler can take advantage of in making +the code more efficient okay okay okay + + align:start position:0% +the code more efficient okay okay okay + + + align:start position:0% +the code more efficient okay okay okay +let's break for questions + + align:start position:0% + + + + align:start position:0% + +you kept saying that the UH eval + + align:start position:0% +you kept saying that the UH eval + + + align:start position:0% +you kept saying that the UH eval +register on average turned didn't need + + align:start position:0% +register on average turned didn't need + + + align:start position:0% +register on average turned didn't need +to be used at all is that mean it you + + align:start position:0% +to be used at all is that mean it you + + + align:start position:0% +to be used at all is that mean it you +could just have a six registered machine + + align:start position:0% +could just have a six registered machine + + + align:start position:0% +could just have a six registered machine +or is that in these particular examples + + align:start position:0% +or is that in these particular examples + + + align:start position:0% +or is that in these particular examples +it didn't need to be used for the + + align:start position:0% +it didn't need to be used for the + + + align:start position:0% +it didn't need to be used for the +compiler you could generate code for the + + align:start position:0% +compiler you could generate code for the + + + align:start position:0% +compiler you could generate code for the +six register five right because their + + align:start position:0% +six register five right because their + + + align:start position:0% +six register five right because their +Dex goes away also assuming yeah you can + + align:start position:0% +Dex goes away also assuming yeah you can + + + align:start position:0% +Dex goes away also assuming yeah you can +get rid of both exponent because see + + align:start position:0% +get rid of both exponent because see + + + align:start position:0% +get rid of both exponent because see +those are data structures of the + + align:start position:0% +those are data structures of the + + + align:start position:0% +those are data structures of the +evaluator those are all things that + + align:start position:0% +evaluator those are all things that + + + align:start position:0% +evaluator those are all things that +would be constants from the point of + + align:start position:0% +would be constants from the point of + + + align:start position:0% +would be constants from the point of +view of the compiler the only thing is + + align:start position:0% +view of the compiler the only thing is + + + align:start position:0% +view of the compiler the only thing is +this particular compiler is set up so + + align:start position:0% +this particular compiler is set up so + + + align:start position:0% +this particular compiler is set up so +that interpreted code and compiled code + + align:start position:0% +that interpreted code and compiled code + + + align:start position:0% +that interpreted code and compiled code +can coexist so the way to think about it + + align:start position:0% +can coexist so the way to think about it + + + align:start position:0% +can coexist so the way to think about it +is is maybe you build a chip which is + + align:start position:0% +is is maybe you build a chip which is + + + align:start position:0% +is is maybe you build a chip which is +the evaluator and what the compiler + + align:start position:0% +the evaluator and what the compiler + + + align:start position:0% +the evaluator and what the compiler +might do is generate code for that chip + + align:start position:0% +might do is generate code for that chip + + + align:start position:0% +might do is generate code for that chip +just wouldn't use two of the registers + + align:start position:0% + + + + align:start position:0% + +alright let's take a break + + align:start position:0% +alright let's take a break + + + align:start position:0% +alright let's take a break +[Music] + + align:start position:0% + + + + align:start position:0% + +we just looked at what the compiler is + + align:start position:0% +we just looked at what the compiler is + + + align:start position:0% +we just looked at what the compiler is +supposed to do now let's very briefly + + align:start position:0% +supposed to do now let's very briefly + + + align:start position:0% +supposed to do now let's very briefly +look at how how this gets accomplished + + align:start position:0% +look at how how this gets accomplished + + + align:start position:0% +look at how how this gets accomplished +and I'm gonna give no details there's + + align:start position:0% +and I'm gonna give no details there's + + + align:start position:0% +and I'm gonna give no details there's +there's a giant pile of code in the book + + align:start position:0% +there's a giant pile of code in the book + + + align:start position:0% +there's a giant pile of code in the book +that gives all the details but what I + + align:start position:0% +that gives all the details but what I + + + align:start position:0% +that gives all the details but what I +want to do is just show you the the + + align:start position:0% +want to do is just show you the the + + + align:start position:0% +want to do is just show you the the +essential idea here worry about the + + align:start position:0% +essential idea here worry about the + + + align:start position:0% +essential idea here worry about the +detail some other time let's imagine + + align:start position:0% +detail some other time let's imagine + + + align:start position:0% +detail some other time let's imagine +that we're compiling an expression that + + align:start position:0% +that we're compiling an expression that + + + align:start position:0% +that we're compiling an expression that +looks like there's some operator and + + align:start position:0% +looks like there's some operator and + + + align:start position:0% +looks like there's some operator and +they're two arguments + + align:start position:0% + + + + align:start position:0% + +now the what's the code that the + + align:start position:0% +now the what's the code that the + + + align:start position:0% +now the what's the code that the +compiler should generate well first of + + align:start position:0% +compiler should generate well first of + + + align:start position:0% +compiler should generate well first of +all it should recursively go off and + + align:start position:0% +all it should recursively go off and + + + align:start position:0% +all it should recursively go off and +compile the operator so it says I'll + + align:start position:0% +compile the operator so it says I'll + + + align:start position:0% +compile the operator so it says I'll +compile the operator and where I'm going + + align:start position:0% +compile the operator and where I'm going + + + align:start position:0% +compile the operator and where I'm going +to need that is to be in the function + + align:start position:0% +to need that is to be in the function + + + align:start position:0% +to need that is to be in the function +register eventually so I'll compile some + + align:start position:0% +register eventually so I'll compile some + + + align:start position:0% +register eventually so I'll compile some +instructions that will compile the + + align:start position:0% +instructions that will compile the + + + align:start position:0% +instructions that will compile the +operator and end up with the result in + + align:start position:0% +operator and end up with the result in + + + align:start position:0% +operator and end up with the result in +the function register + + align:start position:0% + + + + align:start position:0% + +the next thing it's going to do another + + align:start position:0% +the next thing it's going to do another + + + align:start position:0% +the next thing it's going to do another +piece is to say all I have to compile + + align:start position:0% + + + + align:start position:0% + +the first argument so it calls itself + + align:start position:0% +the first argument so it calls itself + + + align:start position:0% +the first argument so it calls itself +recursively and let's say the result + + align:start position:0% +recursively and let's say the result + + + align:start position:0% +recursively and let's say the result +will go into Val and then what it's + + align:start position:0% +will go into Val and then what it's + + + align:start position:0% +will go into Val and then what it's +going to need to do is start setting up + + align:start position:0% +going to need to do is start setting up + + + align:start position:0% +going to need to do is start setting up +the argument list so it'll say assign to + + align:start position:0% +the argument list so it'll say assign to + + + align:start position:0% +the argument list so it'll say assign to +argl + + align:start position:0% + + + + align:start position:0% + +cons Stach so it generates this literal + + align:start position:0% +cons Stach so it generates this literal + + + align:start position:0% +cons Stach so it generates this literal +instruction fetch eval on two empty + + align:start position:0% +instruction fetch eval on two empty + + + align:start position:0% +instruction fetch eval on two empty +lists okay however it might have to work + + align:start position:0% +lists okay however it might have to work + + + align:start position:0% +lists okay however it might have to work +it's good when it gets here it's gonna + + align:start position:0% +it's good when it gets here it's gonna + + + align:start position:0% +it's good when it gets here it's gonna +need the environment that's need + + align:start position:0% +need the environment that's need + + + align:start position:0% +need the environment that's need +whatever environment was here in order + + align:start position:0% +whatever environment was here in order + + + align:start position:0% +whatever environment was here in order +to do this evaluation of the first + + align:start position:0% +to do this evaluation of the first + + + align:start position:0% +to do this evaluation of the first +argument so it has to ensure that the + + align:start position:0% +argument so it has to ensure that the + + + align:start position:0% +argument so it has to ensure that the +compilation of this operand or it has to + + align:start position:0% +compilation of this operand or it has to + + + align:start position:0% +compilation of this operand or it has to +protect the function register against + + align:start position:0% +protect the function register against + + + align:start position:0% +protect the function register against +whatever might happen in the compilation + + align:start position:0% +whatever might happen in the compilation + + + align:start position:0% +whatever might happen in the compilation +of this operand so it puts a note here + + align:start position:0% +of this operand so it puts a note here + + + align:start position:0% +of this operand so it puts a note here +and says oh this piece should be done + + align:start position:0% +and says oh this piece should be done + + + align:start position:0% +and says oh this piece should be done +preserving the environment register + + align:start position:0% + + + + align:start position:0% + +similarly here after it gets done + + align:start position:0% +similarly here after it gets done + + + align:start position:0% +similarly here after it gets done +compiling the first operand it's going + + align:start position:0% +compiling the first operand it's going + + + align:start position:0% +compiling the first operand it's going +to say I better compile I'm gonna need + + align:start position:0% +to say I better compile I'm gonna need + + + align:start position:0% +to say I better compile I'm gonna need +to know the environment for the second + + align:start position:0% +to know the environment for the second + + + align:start position:0% +to know the environment for the second +operand so it puts a little note here + + align:start position:0% +operand so it puts a little note here + + + align:start position:0% +operand so it puts a little note here +saying yeah this is also done preserving + + align:start position:0% +saying yeah this is also done preserving + + + align:start position:0% +saying yeah this is also done preserving +M + + align:start position:0% + + + + align:start position:0% + +right now it goes on and says well the + + align:start position:0% +right now it goes on and says well the + + + align:start position:0% +right now it goes on and says well the +next chunk of code is the one that's + + align:start position:0% +next chunk of code is the one that's + + + align:start position:0% +next chunk of code is the one that's +going to compile the second argument and + + align:start position:0% +going to compile the second argument and + + + align:start position:0% +going to compile the second argument and +let's say it'll compile it with a + + align:start position:0% + + + + align:start position:0% + +targeted to the L as they say and then + + align:start position:0% +targeted to the L as they say and then + + + align:start position:0% +targeted to the L as they say and then +it'll generate the literal instruction + + align:start position:0% +it'll generate the literal instruction + + + align:start position:0% +it'll generate the literal instruction +building up the argument list so it'll + + align:start position:0% +building up the argument list so it'll + + + align:start position:0% +building up the argument list so it'll +say assign to argl cons of the new value + + align:start position:0% +say assign to argl cons of the new value + + + align:start position:0% +say assign to argl cons of the new value +it just got on to the old argument list + + align:start position:0% + + + + align:start position:0% + +however in order to have the old + + align:start position:0% +however in order to have the old + + + align:start position:0% +however in order to have the old +argument list it better have arranged + + align:start position:0% +argument list it better have arranged + + + align:start position:0% +argument list it better have arranged +that the argument list didn't get + + align:start position:0% +that the argument list didn't get + + + align:start position:0% +that the argument list didn't get +trashed by whatever happened in here so + + align:start position:0% +trashed by whatever happened in here so + + + align:start position:0% +trashed by whatever happened in here so +it puts a little note here and says oh + + align:start position:0% +it puts a little note here and says oh + + + align:start position:0% +it puts a little note here and says oh +well this has to be done preserving + + align:start position:0% + + + + align:start position:0% + +partl right now it's got the argument + + align:start position:0% +partl right now it's got the argument + + + align:start position:0% +partl right now it's got the argument +list set up and it's all ready to go to + + align:start position:0% +list set up and it's all ready to go to + + + align:start position:0% +list set up and it's all ready to go to +apply dispatch generates this literal + + align:start position:0% +apply dispatch generates this literal + + + align:start position:0% +apply dispatch generates this literal +instruction + + align:start position:0% + + + + align:start position:0% + +because it now it's got the arguments in + + align:start position:0% +because it now it's got the arguments in + + + align:start position:0% +because it now it's got the arguments in +argyll and the operator and fun but but + + align:start position:0% +argyll and the operator and fun but but + + + align:start position:0% +argyll and the operator and fun but but +wait it's only got the operator in fun + + align:start position:0% +wait it's only got the operator in fun + + + align:start position:0% +wait it's only got the operator in fun +if it had ensured that this block of + + align:start position:0% +if it had ensured that this block of + + + align:start position:0% +if it had ensured that this block of +code didn't trash what was in the + + align:start position:0% +code didn't trash what was in the + + + align:start position:0% +code didn't trash what was in the +function register so it puts a little + + align:start position:0% +function register so it puts a little + + + align:start position:0% +function register so it puts a little +note here and said oh yes all this stuff + + align:start position:0% +note here and said oh yes all this stuff + + + align:start position:0% +note here and said oh yes all this stuff +here had better be done preserving the + + align:start position:0% +here had better be done preserving the + + + align:start position:0% +here had better be done preserving the +function register so that's the little + + align:start position:0% +function register so that's the little + + + align:start position:0% +function register so that's the little +so when it starts sticking so basically + + align:start position:0% +so when it starts sticking so basically + + + align:start position:0% +so when it starts sticking so basically +what the what the compiler does is + + align:start position:0% +what the what the compiler does is + + + align:start position:0% +what the what the compiler does is +append a whole bunch of code sequences + + align:start position:0% +append a whole bunch of code sequences + + + align:start position:0% +append a whole bunch of code sequences +see what it's got in it is little + + align:start position:0% +see what it's got in it is little + + + align:start position:0% +see what it's got in it is little +primitive pieces of things like how to + + align:start position:0% +primitive pieces of things like how to + + + align:start position:0% +primitive pieces of things like how to +look up a symbol how to do a conditional + + align:start position:0% +look up a symbol how to do a conditional + + + align:start position:0% +look up a symbol how to do a conditional +those are all little little pieces of + + align:start position:0% +those are all little little pieces of + + + align:start position:0% +those are all little little pieces of +things and then it appends them together + + align:start position:0% +things and then it appends them together + + + align:start position:0% +things and then it appends them together +in this sort of discipline so the basic + + align:start position:0% +in this sort of discipline so the basic + + + align:start position:0% +in this sort of discipline so the basic +means of combining things is to append + + align:start position:0% +means of combining things is to append + + + align:start position:0% +means of combining things is to append +two code sequences that's what's going + + align:start position:0% +two code sequences that's what's going + + + align:start position:0% +two code sequences that's what's going +on here and it's a little bit tricky the + + align:start position:0% +on here and it's a little bit tricky the + + + align:start position:0% +on here and it's a little bit tricky the +idea is that it depends two code + + align:start position:0% +idea is that it depends two code + + + align:start position:0% +idea is that it depends two code +sequences taking care to preserve or + + align:start position:0% +sequences taking care to preserve or + + + align:start position:0% +sequences taking care to preserve or +register + + align:start position:0% +register + + + align:start position:0% +register +so the actual append operation looks + + align:start position:0% +so the actual append operation looks + + + align:start position:0% +so the actual append operation looks +like this what it wants to do is say if + + align:start position:0% +like this what it wants to do is say if + + + align:start position:0% +like this what it wants to do is say if +here's what it means to attend two code + + align:start position:0% +here's what it means to attend two code + + + align:start position:0% +here's what it means to attend two code +sequences so if sequence one needs + + align:start position:0% + + + + align:start position:0% + +register I should change this append + + align:start position:0% +register I should change this append + + + align:start position:0% +register I should change this append +sequence 1 to sequence to preserve him + + align:start position:0% + + + + align:start position:0% + +some register yeah let me say an so it's + + align:start position:0% +some register yeah let me say an so it's + + + align:start position:0% +some register yeah let me say an so it's +clear that sequence 1 comes first + + align:start position:0% +clear that sequence 1 comes first + + + align:start position:0% +clear that sequence 1 comes first +so if sequence 2 needs the register and + + align:start position:0% + + + + align:start position:0% + +sequence 1 modifies the register then + + align:start position:0% +sequence 1 modifies the register then + + + align:start position:0% +sequence 1 modifies the register then +the instructions that the compiler spits + + align:start position:0% +the instructions that the compiler spits + + + align:start position:0% +the instructions that the compiler spits +out or save the register right here's + + align:start position:0% +out or save the register right here's + + + align:start position:0% +out or save the register right here's +the code you generate this code save the + + align:start position:0% +the code you generate this code save the + + + align:start position:0% +the code you generate this code save the +register and then you put out the + + align:start position:0% +register and then you put out the + + + align:start position:0% +register and then you put out the +recursively compiled stuff for sequence + + align:start position:0% +recursively compiled stuff for sequence + + + align:start position:0% +recursively compiled stuff for sequence +1 and then you restore the register and + + align:start position:0% +1 and then you restore the register and + + + align:start position:0% +1 and then you restore the register and +then you put out the recursively + + align:start position:0% +then you put out the recursively + + + align:start position:0% +then you put out the recursively +compiled stuff for sequence 2 right + + align:start position:0% +compiled stuff for sequence 2 right + + + align:start position:0% +compiled stuff for sequence 2 right +that's in the case where where you need + + align:start position:0% +that's in the case where where you need + + + align:start position:0% +that's in the case where where you need +to do it sequence 2 actually needs the + + align:start position:0% +to do it sequence 2 actually needs the + + + align:start position:0% +to do it sequence 2 actually needs the +register and sequence one actually + + align:start position:0% +register and sequence one actually + + + align:start position:0% +register and sequence one actually +clobbers it actually that's sort of if + + align:start position:0% +clobbers it actually that's sort of if + + + align:start position:0% +clobbers it actually that's sort of if +otherwise all you spit out is sequence 1 + + align:start position:0% +otherwise all you spit out is sequence 1 + + + align:start position:0% +otherwise all you spit out is sequence 1 +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +followed by sequence 2 so that's the + + align:start position:0% +followed by sequence 2 so that's the + + + align:start position:0% +followed by sequence 2 so that's the +basic operation for sticking together + + align:start position:0% +basic operation for sticking together + + + align:start position:0% +basic operation for sticking together +these bits of code fragments these bits + + align:start position:0% +these bits of code fragments these bits + + + align:start position:0% +these bits of code fragments these bits +of instructions into a sequence and you + + align:start position:0% +of instructions into a sequence and you + + + align:start position:0% +of instructions into a sequence and you +see from this point of view the the + + align:start position:0% +see from this point of view the the + + + align:start position:0% +see from this point of view the the +difference between the interpreter and + + align:start position:0% +difference between the interpreter and + + + align:start position:0% +difference between the interpreter and +the compiler in some sense is that where + + align:start position:0% +the compiler in some sense is that where + + + align:start position:0% +the compiler in some sense is that where +the compiler has these preserving notes + + align:start position:0% +the compiler has these preserving notes + + + align:start position:0% +the compiler has these preserving notes +and says maybe I'll actually generate + + align:start position:0% +and says maybe I'll actually generate + + + align:start position:0% +and says maybe I'll actually generate +the saves and restores and maybe I want + + align:start position:0% +the saves and restores and maybe I want + + + align:start position:0% +the saves and restores and maybe I want +the interpreter being maximally + + align:start position:0% +the interpreter being maximally + + + align:start position:0% +the interpreter being maximally +pessimistic always has a save and + + align:start position:0% +pessimistic always has a save and + + + align:start position:0% +pessimistic always has a save and +restore here that's that's the essential + + align:start position:0% +restore here that's that's the essential + + + align:start position:0% +restore here that's that's the essential +difference + + align:start position:0% +difference + + + align:start position:0% +difference +well in order to do this of course the + + align:start position:0% +well in order to do this of course the + + + align:start position:0% +well in order to do this of course the +compiler needs some theory of what code + + align:start position:0% +compiler needs some theory of what code + + + align:start position:0% +compiler needs some theory of what code +sequences need and modifier registers so + + align:start position:0% +sequences need and modifier registers so + + + align:start position:0% +sequences need and modifier registers so +the the tiny little fragments that you + + align:start position:0% +the the tiny little fragments that you + + + align:start position:0% +the the tiny little fragments that you +put in like the basic primitive code + + align:start position:0% +put in like the basic primitive code + + + align:start position:0% +put in like the basic primitive code +fragments say what are the operations + + align:start position:0% +fragments say what are the operations + + + align:start position:0% +fragments say what are the operations +that you do when you look up a variable + + align:start position:0% +that you do when you look up a variable + + + align:start position:0% +that you do when you look up a variable +what are the sequence of things that you + + align:start position:0% +what are the sequence of things that you + + + align:start position:0% +what are the sequence of things that you +do when you compile a constant or apply + + align:start position:0% +do when you compile a constant or apply + + + align:start position:0% +do when you compile a constant or apply +a function those have little notations + + align:start position:0% +a function those have little notations + + + align:start position:0% +a function those have little notations +in there about what they need in what + + align:start position:0% +in there about what they need in what + + + align:start position:0% +in there about what they need in what +they modify so the the bottom level data + + align:start position:0% +they modify so the the bottom level data + + + align:start position:0% +they modify so the the bottom level data +structures block say this a code + + align:start position:0% +structures block say this a code + + + align:start position:0% +structures block say this a code +sequence to the compiler looks like this + + align:start position:0% +sequence to the compiler looks like this + + + align:start position:0% +sequence to the compiler looks like this +it has the the actual sequence of + + align:start position:0% +it has the the actual sequence of + + + align:start position:0% +it has the the actual sequence of +instructions and then along with it + + align:start position:0% +instructions and then along with it + + + align:start position:0% +instructions and then along with it +there's the there's the set of registers + + align:start position:0% +there's the there's the set of registers + + + align:start position:0% +there's the there's the set of registers +modified and then there's the set of + + align:start position:0% +modified and then there's the set of + + + align:start position:0% +modified and then there's the set of +registers needed so that's the + + align:start position:0% +registers needed so that's the + + + align:start position:0% +registers needed so that's the +information the compiler has that it + + align:start position:0% +information the compiler has that it + + + align:start position:0% +information the compiler has that it +draws on in order to be able to do this + + align:start position:0% +draws on in order to be able to do this + + + align:start position:0% +draws on in order to be able to do this +operation and where do those come from + + align:start position:0% +operation and where do those come from + + + align:start position:0% +operation and where do those come from +well those come from you might expect + + align:start position:0% +well those come from you might expect + + + align:start position:0% +well those come from you might expect +for the very primitive ones we're going + + align:start position:0% +for the very primitive ones we're going + + + align:start position:0% +for the very primitive ones we're going +to put them in by hand and then when we + + align:start position:0% +to put them in by hand and then when we + + + align:start position:0% +to put them in by hand and then when we +combine two sequences we'll figure out + + align:start position:0% +combine two sequences we'll figure out + + + align:start position:0% +combine two sequences we'll figure out +what these things should be so for + + align:start position:0% +what these things should be so for + + + align:start position:0% +what these things should be so for +example a very primitive one let's see + + align:start position:0% +example a very primitive one let's see + + + align:start position:0% +example a very primitive one let's see +how about doing a register assignment so + + align:start position:0% +how about doing a register assignment so + + + align:start position:0% +how about doing a register assignment so +a primitive sequence might say oh it's + + align:start position:0% +a primitive sequence might say oh it's + + + align:start position:0% +a primitive sequence might say oh it's +code fragment it's code instruction is + + align:start position:0% +code fragment it's code instruction is + + + align:start position:0% +code fragment it's code instruction is +assigned to r1 + + align:start position:0% + + + + align:start position:0% + +fetch of our two so this is an example + + align:start position:0% +fetch of our two so this is an example + + + align:start position:0% +fetch of our two so this is an example +that might be an example of a sequence + + align:start position:0% +that might be an example of a sequence + + + align:start position:0% +that might be an example of a sequence +of instructions and along with that + + align:start position:0% +of instructions and along with that + + + align:start position:0% +of instructions and along with that +it'll say oh what I need to remember is + + align:start position:0% +it'll say oh what I need to remember is + + + align:start position:0% +it'll say oh what I need to remember is +that that modifies r1 and then it needs + + align:start position:0% +that that modifies r1 and then it needs + + + align:start position:0% +that that modifies r1 and then it needs +are two right so there so when you're + + align:start position:0% +are two right so there so when you're + + + align:start position:0% +are two right so there so when you're +first building this compiler you put in + + align:start position:0% +first building this compiler you put in + + + align:start position:0% +first building this compiler you put in +little fragments and stuff like that + + align:start position:0% +little fragments and stuff like that + + + align:start position:0% +little fragments and stuff like that +and now when it combines two sequences + + align:start position:0% +and now when it combines two sequences + + + align:start position:0% +and now when it combines two sequences +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +but if I'm going to combine let's say + + align:start position:0% +but if I'm going to combine let's say + + + align:start position:0% +but if I'm going to combine let's say +sequence one that modifies a bunch of + + align:start position:0% +sequence one that modifies a bunch of + + + align:start position:0% +sequence one that modifies a bunch of +registers m1 and needs a bunch of + + align:start position:0% +registers m1 and needs a bunch of + + + align:start position:0% +registers m1 and needs a bunch of +registers in one and I'm going to + + align:start position:0% +registers in one and I'm going to + + + align:start position:0% +registers in one and I'm going to +combine that with sequence to that + + align:start position:0% +combine that with sequence to that + + + align:start position:0% +combine that with sequence to that +modifies a bunch of registers m2 and + + align:start position:0% +modifies a bunch of registers m2 and + + + align:start position:0% +modifies a bunch of registers m2 and +needs a bunch of registers in two then + + align:start position:0% +needs a bunch of registers in two then + + + align:start position:0% +needs a bunch of registers in two then +what we can reason it out the new code + + align:start position:0% +what we can reason it out the new code + + + align:start position:0% +what we can reason it out the new code +fragment sequence one and sequence + + align:start position:0% +fragment sequence one and sequence + + + align:start position:0% +fragment sequence one and sequence +followed by sequence two well what's it + + align:start position:0% +followed by sequence two well what's it + + + align:start position:0% +followed by sequence two well what's it +going to modify the things that will + + align:start position:0% +going to modify the things that will + + + align:start position:0% +going to modify the things that will +modify are the things that are modified + + align:start position:0% +modify are the things that are modified + + + align:start position:0% +modify are the things that are modified +either by sequence 1 or sequence 2 so + + align:start position:0% +either by sequence 1 or sequence 2 so + + + align:start position:0% +either by sequence 1 or sequence 2 so +the union of these two sets are what the + + align:start position:0% +the union of these two sets are what the + + + align:start position:0% +the union of these two sets are what the +new thing modifies and then you say well + + align:start position:0% +new thing modifies and then you say well + + + align:start position:0% +new thing modifies and then you say well +what is this what registers is it going + + align:start position:0% +what is this what registers is it going + + + align:start position:0% +what is this what registers is it going +to need it's going to need the things + + align:start position:0% +to need it's going to need the things + + + align:start position:0% +to need it's going to need the things +that are first of all needed by sequence + + align:start position:0% +that are first of all needed by sequence + + + align:start position:0% +that are first of all needed by sequence +1 so what it needs a sequence 1 and then + + align:start position:0% +1 so what it needs a sequence 1 and then + + + align:start position:0% +1 so what it needs a sequence 1 and then +well not quite all of the ones that are + + align:start position:0% +well not quite all of the ones that are + + + align:start position:0% +well not quite all of the ones that are +needed by sequence 2 what it needs are + + align:start position:0% +needed by sequence 2 what it needs are + + + align:start position:0% +needed by sequence 2 what it needs are +the the ones that are needed by sequence + + align:start position:0% +the the ones that are needed by sequence + + + align:start position:0% +the the ones that are needed by sequence +two that have not been set up by by + + align:start position:0% +two that have not been set up by by + + + align:start position:0% +two that have not been set up by by +sequence one so it's sort of the union + + align:start position:0% +sequence one so it's sort of the union + + + align:start position:0% +sequence one so it's sort of the union +of + + align:start position:0% +of + + + align:start position:0% +of +the things that sequence to needs - the + + align:start position:0% +the things that sequence to needs - the + + + align:start position:0% +the things that sequence to needs - the +ones that sequence one modifies because + + align:start position:0% +ones that sequence one modifies because + + + align:start position:0% +ones that sequence one modifies because +it worries about setting them up alright + + align:start position:0% +it worries about setting them up alright + + + align:start position:0% +it worries about setting them up alright +so there's the basic structure of the + + align:start position:0% +so there's the basic structure of the + + + align:start position:0% +so there's the basic structure of the +compiler the way you do register + + align:start position:0% +compiler the way you do register + + + align:start position:0% +compiler the way you do register +optimizations is you have some + + align:start position:0% +optimizations is you have some + + + align:start position:0% +optimizations is you have some +strategies for what needs to be + + align:start position:0% +strategies for what needs to be + + + align:start position:0% +strategies for what needs to be +preserved that depends on a data + + align:start position:0% +preserved that depends on a data + + + align:start position:0% +preserved that depends on a data +structure what depends on the operation + + align:start position:0% +structure what depends on the operation + + + align:start position:0% +structure what depends on the operation +of what it means to put things together + + align:start position:0% +of what it means to put things together + + + align:start position:0% +of what it means to put things together +preserving something that depends on + + align:start position:0% +preserving something that depends on + + + align:start position:0% +preserving something that depends on +knowing what what registers are needed + + align:start position:0% +knowing what what registers are needed + + + align:start position:0% +knowing what what registers are needed +and modified by these code fragments + + align:start position:0% +and modified by these code fragments + + + align:start position:0% +and modified by these code fragments +that depends on having little data + + align:start position:0% +that depends on having little data + + + align:start position:0% +that depends on having little data +structures which say a code sequence is + + align:start position:0% +structures which say a code sequence is + + + align:start position:0% +structures which say a code sequence is +the actual instructions what they modify + + align:start position:0% +the actual instructions what they modify + + + align:start position:0% +the actual instructions what they modify +and what they need that comes from at + + align:start position:0% +and what they need that comes from at + + + align:start position:0% +and what they need that comes from at +the primitive level building it in and + + align:start position:0% +the primitive level building it in and + + + align:start position:0% +the primitive level building it in and +there's all that the primitive level + + align:start position:0% +there's all that the primitive level + + + align:start position:0% +there's all that the primitive level +it's going to be completely obvious what + + align:start position:0% +it's going to be completely obvious what + + + align:start position:0% +it's going to be completely obvious what +something needs and modifies plus this + + align:start position:0% +something needs and modifies plus this + + + align:start position:0% +something needs and modifies plus this +particular way that says when I build up + + align:start position:0% +particular way that says when I build up + + + align:start position:0% +particular way that says when I build up +bigger ones here's how I generate the + + align:start position:0% +bigger ones here's how I generate the + + + align:start position:0% +bigger ones here's how I generate the +new set of registers modified and the + + align:start position:0% +new set of registers modified and the + + + align:start position:0% +new set of registers modified and the +new set of registers needed and that's + + align:start position:0% +new set of registers needed and that's + + + align:start position:0% +new set of registers needed and that's +all well I shouldn't say that's the + + align:start position:0% +all well I shouldn't say that's the + + + align:start position:0% +all well I shouldn't say that's the +whole thing that's the whole thing + + align:start position:0% +whole thing that's the whole thing + + + align:start position:0% +whole thing that's the whole thing +except for about about 30 pages of + + align:start position:0% +except for about about 30 pages of + + + align:start position:0% +except for about about 30 pages of +details in the book but it is a it is a + + align:start position:0% +details in the book but it is a it is a + + + align:start position:0% +details in the book but it is a it is a +perfectly read a usable rudimentary + + align:start position:0% +perfectly read a usable rudimentary + + + align:start position:0% +perfectly read a usable rudimentary +compiler let me let me kind of show you + + align:start position:0% +compiler let me let me kind of show you + + + align:start position:0% +compiler let me let me kind of show you +what what it does suppose we start out + + align:start position:0% +what what it does suppose we start out + + + align:start position:0% +what what it does suppose we start out +with with recursive factorial and these + + align:start position:0% +with with recursive factorial and these + + + align:start position:0% +with with recursive factorial and these +slides are gonna be much too too small + + align:start position:0% +slides are gonna be much too too small + + + align:start position:0% +slides are gonna be much too too small +to read I just want to flash through the + + align:start position:0% +to read I just want to flash through the + + + align:start position:0% +to read I just want to flash through the +code and show you about how much it is + + align:start position:0% +code and show you about how much it is + + + align:start position:0% +code and show you about how much it is +that starts out with here's a first + + align:start position:0% +that starts out with here's a first + + + align:start position:0% +that starts out with here's a first +block of it where it compiles a + + align:start position:0% +block of it where it compiles a + + + align:start position:0% +block of it where it compiles a +procedure entry and does a bunch of + + align:start position:0% +procedure entry and does a bunch of + + + align:start position:0% +procedure entry and does a bunch of +assignments and this thing is basically + + align:start position:0% +assignments and this thing is basically + + + align:start position:0% +assignments and this thing is basically +up through the part where it sets up to + + align:start position:0% +up through the part where it sets up to + + + align:start position:0% +up through the part where it sets up to +do the predicate and test whether the + + align:start position:0% +do the predicate and test whether the + + + align:start position:0% +do the predicate and test whether the +predicate is true the second part is + + align:start position:0% +predicate is true the second part is + + + align:start position:0% +predicate is true the second part is +what results from the in the recursive + + align:start position:0% +what results from the in the recursive + + + align:start position:0% +what results from the in the recursive +call - to fact of n minus 1 and this + + align:start position:0% +call - to fact of n minus 1 and this + + + align:start position:0% +call - to fact of n minus 1 and this +last part is coming back from that and + + align:start position:0% +last part is coming back from that and + + + align:start position:0% +last part is coming back from that and +then taking care of the constant case so + + align:start position:0% +then taking care of the constant case so + + + align:start position:0% +then taking care of the constant case so +that's about how much code it would + + align:start position:0% +that's about how much code it would + + + align:start position:0% +that's about how much code it would +produce for factorial we could make this + + align:start position:0% +produce for factorial we could make this + + + align:start position:0% +produce for factorial we could make this +compiler much much better of course the + + align:start position:0% +compiler much much better of course the + + + align:start position:0% +compiler much much better of course the +the main way we could make it better is + + align:start position:0% +the main way we could make it better is + + + align:start position:0% +the main way we could make it better is +to allow the compiler to make any + + align:start position:0% +to allow the compiler to make any + + + align:start position:0% +to allow the compiler to make any +assumptions at all + + align:start position:0% +assumptions at all + + + align:start position:0% +assumptions at all +about what happens when you call a + + align:start position:0% +about what happens when you call a + + + align:start position:0% +about what happens when you call a +procedure so this compiler for instance + + align:start position:0% +procedure so this compiler for instance + + + align:start position:0% +procedure so this compiler for instance +doesn't even know say that + + align:start position:0% +doesn't even know say that + + + align:start position:0% +doesn't even know say that +multiplication is it is something that + + align:start position:0% +multiplication is it is something that + + + align:start position:0% +multiplication is it is something that +could be coded inline instead it sets up + + align:start position:0% +could be coded inline instead it sets up + + + align:start position:0% +could be coded inline instead it sets up +this whole mechanism goes to apply + + align:start position:0% +this whole mechanism goes to apply + + + align:start position:0% +this whole mechanism goes to apply +dispatch that's a tremendous waste + + align:start position:0% +dispatch that's a tremendous waste + + + align:start position:0% +dispatch that's a tremendous waste +because what you do it every time you go + + align:start position:0% +because what you do it every time you go + + + align:start position:0% +because what you do it every time you go +to apply dispatch is you have to concept + + align:start position:0% +to apply dispatch is you have to concept + + + align:start position:0% +to apply dispatch is you have to concept +this argument list because it's a very + + align:start position:0% +this argument list because it's a very + + + align:start position:0% +this argument list because it's a very +general thing you're going to in any + + align:start position:0% +general thing you're going to in any + + + align:start position:0% +general thing you're going to in any +real compiler of course you're going to + + align:start position:0% +real compiler of course you're going to + + + align:start position:0% +real compiler of course you're going to +have registers for holding arguments and + + align:start position:0% +have registers for holding arguments and + + + align:start position:0% +have registers for holding arguments and +you're going to start preserving and + + align:start position:0% +you're going to start preserving and + + + align:start position:0% +you're going to start preserving and +saving the way you use those registers + + align:start position:0% +saving the way you use those registers + + + align:start position:0% +saving the way you use those registers +similar similar to the same strategy + + align:start position:0% +similar similar to the same strategy + + + align:start position:0% +similar similar to the same strategy +here so that's the that's probably the + + align:start position:0% +here so that's the that's probably the + + + align:start position:0% +here so that's the that's probably the +very the very mean way that this + + align:start position:0% +very the very mean way that this + + + align:start position:0% +very the very mean way that this +particular compiler in the book could be + + align:start position:0% +particular compiler in the book could be + + + align:start position:0% +particular compiler in the book could be +fixed there are other things like + + align:start position:0% +fixed there are other things like + + + align:start position:0% +fixed there are other things like +looking up variable values and making + + align:start position:0% +looking up variable values and making + + + align:start position:0% +looking up variable values and making +more efficient primitive operations and + + align:start position:0% +more efficient primitive operations and + + + align:start position:0% +more efficient primitive operations and +all sorts of things essentially a good + + align:start position:0% +all sorts of things essentially a good + + + align:start position:0% +all sorts of things essentially a good +list of compiler can absorb an arbitrary + + align:start position:0% +list of compiler can absorb an arbitrary + + + align:start position:0% +list of compiler can absorb an arbitrary +amount of effort and probably one of the + + align:start position:0% +amount of effort and probably one of the + + + align:start position:0% +amount of effort and probably one of the +reasons that Lisp is slow with compared + + align:start position:0% +reasons that Lisp is slow with compared + + + align:start position:0% +reasons that Lisp is slow with compared +to languages like Fortran is that if you + + align:start position:0% +to languages like Fortran is that if you + + + align:start position:0% +to languages like Fortran is that if you +if you look over history at the amount + + align:start position:0% +if you look over history at the amount + + + align:start position:0% +if you look over history at the amount +of effort that's gone into building + + align:start position:0% +of effort that's gone into building + + + align:start position:0% +of effort that's gone into building +lists compilers it's nowhere near the + + align:start position:0% +lists compilers it's nowhere near the + + + align:start position:0% +lists compilers it's nowhere near the +amount of effort that's gone into + + align:start position:0% +amount of effort that's gone into + + + align:start position:0% +amount of effort that's gone into +Fortran compilers and maybe that's + + align:start position:0% +Fortran compilers and maybe that's + + + align:start position:0% +Fortran compilers and maybe that's +something that all that I'll change over + + align:start position:0% +something that all that I'll change over + + + align:start position:0% +something that all that I'll change over +the next couple of years ok let's break + + align:start position:0% + + + + align:start position:0% + +question is + + align:start position:0% + + + + align:start position:0% + +one of the very first classes I don't + + align:start position:0% +one of the very first classes I don't + + + align:start position:0% +one of the very first classes I don't +lose during class or after class you + + align:start position:0% +lose during class or after class you + + + align:start position:0% +lose during class or after class you +showed showed me the that say add + + align:start position:0% +showed showed me the that say add + + + align:start position:0% +showed showed me the that say add +addition has a primitive that we don't + + align:start position:0% +addition has a primitive that we don't + + + align:start position:0% +addition has a primitive that we don't +see ampersand add or something like that + + align:start position:0% +see ampersand add or something like that + + + align:start position:0% +see ampersand add or something like that +does that is that because if you're + + align:start position:0% +does that is that because if you're + + + align:start position:0% +does that is that because if you're +doing inline code you'd want to just do + + align:start position:0% +doing inline code you'd want to just do + + + align:start position:0% +doing inline code you'd want to just do +it for two you can just do it for two + + align:start position:0% +it for two you can just do it for two + + + align:start position:0% +it for two you can just do it for two +upgraders operands but if you if you had + + align:start position:0% +upgraders operands but if you if you had + + + align:start position:0% +upgraders operands but if you if you had +more operand you run into something + + align:start position:0% +more operand you run into something + + + align:start position:0% +more operand you run into something +special yeah this you're looking at the + + align:start position:0% +special yeah this you're looking at the + + + align:start position:0% +special yeah this you're looking at the +in the actual scheme implementation + + align:start position:0% +in the actual scheme implementation + + + align:start position:0% +in the actual scheme implementation +there's a plus and the plus of some + + align:start position:0% +there's a plus and the plus of some + + + align:start position:0% +there's a plus and the plus of some +operator and if you go look inside the + + align:start position:0% +operator and if you go look inside the + + + align:start position:0% +operator and if you go look inside the +code for plus you see something called I + + align:start position:0% +code for plus you see something called I + + + align:start position:0% +code for plus you see something called I +forget an percent plus or something like + + align:start position:0% +forget an percent plus or something like + + + align:start position:0% +forget an percent plus or something like +that and what's going on there is that + + align:start position:0% +that and what's going on there is that + + + align:start position:0% +that and what's going on there is that +particular kind of optimization because + + align:start position:0% +particular kind of optimization because + + + align:start position:0% +particular kind of optimization because +the general plus takes an arbitrary + + align:start position:0% +the general plus takes an arbitrary + + + align:start position:0% +the general plus takes an arbitrary +number of arguments so the most general + + align:start position:0% +number of arguments so the most general + + + align:start position:0% +number of arguments so the most general +plus says all if I have an argument list + + align:start position:0% +plus says all if I have an argument list + + + align:start position:0% +plus says all if I have an argument list +I'd better I did a concert up in some + + align:start position:0% +I'd better I did a concert up in some + + + align:start position:0% +I'd better I did a concert up in some +list and then figure out how many there + + align:start position:0% +list and then figure out how many there + + + align:start position:0% +list and then figure out how many there +were something like that that's terribly + + align:start position:0% +were something like that that's terribly + + + align:start position:0% +were something like that that's terribly +inefficient especially since most of the + + align:start position:0% +inefficient especially since most of the + + + align:start position:0% +inefficient especially since most of the +time you're probably adding two numbers + + align:start position:0% +time you're probably adding two numbers + + + align:start position:0% +time you're probably adding two numbers +you don't want to really have to + + align:start position:0% +you don't want to really have to + + + align:start position:0% +you don't want to really have to +conscious argument list so what you'd + + align:start position:0% +conscious argument list so what you'd + + + align:start position:0% +conscious argument list so what you'd +like to do is build the code for plus + + align:start position:0% +like to do is build the code for plus + + + align:start position:0% +like to do is build the code for plus +with a bunch of entries so most of what + + align:start position:0% +with a bunch of entries so most of what + + + align:start position:0% +with a bunch of entries so most of what +it's doing is the same however there + + align:start position:0% +it's doing is the same however there + + + align:start position:0% +it's doing is the same however there +might be a special entry that you'd go + + align:start position:0% +might be a special entry that you'd go + + + align:start position:0% +might be a special entry that you'd go +to if you knew they're only two + + align:start position:0% +to if you knew they're only two + + + align:start position:0% +to if you knew they're only two +arguments and those you'll put in + + align:start position:0% +arguments and those you'll put in + + + align:start position:0% +arguments and those you'll put in +registers they won't be in an argument + + align:start position:0% +registers they won't be in an argument + + + align:start position:0% +registers they won't be in an argument +list and you won't have to cost and + + align:start position:0% +list and you won't have to cost and + + + align:start position:0% +list and you won't have to cost and +that's how a lot of these things work + + align:start position:0% +that's how a lot of these things work + + + align:start position:0% +that's how a lot of these things work +okay let's take a break + + align:start position:0% +okay let's take a break + + + align:start position:0% +okay let's take a break +[Music] \ No newline at end of file diff --git a/ViSVJJoo7nE.txt b/ViSVJJoo7nE.txt new file mode 100644 index 0000000000000000000000000000000000000000..b74a51ca34f86bde56244b9b132c8ce198a1c598 --- /dev/null +++ b/ViSVJJoo7nE.txt @@ -0,0 +1,10979 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so today was a little + + align:start position:0% +ocw.mit.edu so today was a little + + + align:start position:0% +ocw.mit.edu so today was a little +different than yesterday so I thought it + + align:start position:0% +different than yesterday so I thought it + + + align:start position:0% +different than yesterday so I thought it +would be good for us to just sort of + + align:start position:0% +would be good for us to just sort of + + + align:start position:0% +would be good for us to just sort of +recap what happened um let's go back to + + align:start position:0% +recap what happened um let's go back to + + + align:start position:0% +recap what happened um let's go back to +the sixth graders visit thank you Jamie + + align:start position:0% +the sixth graders visit thank you Jamie + + + align:start position:0% +the sixth graders visit thank you Jamie +for prepping them for it I I I woke up + + align:start position:0% +for prepping them for it I I I woke up + + + align:start position:0% +for prepping them for it I I I woke up +this morning I was like I didn't prep + + align:start position:0% +this morning I was like I didn't prep + + + align:start position:0% +this morning I was like I didn't prep +them for it if I were them I would have + + align:start position:0% +them for it if I were them I would have + + + align:start position:0% +them for it if I were them I would have +been super overwhelmed I'm a terrible + + align:start position:0% +been super overwhelmed I'm a terrible + + + align:start position:0% +been super overwhelmed I'm a terrible +person um was that helpful to you what + + align:start position:0% +person um was that helpful to you what + + + align:start position:0% +person um was that helpful to you what +did you guys think about that whole + + align:start position:0% + + + + align:start position:0% + +experience I immediately knew that + + align:start position:0% +experience I immediately knew that + + + align:start position:0% +experience I immediately knew that +whatever ideas I had yesterday was + + align:start position:0% +whatever ideas I had yesterday was + + + align:start position:0% +whatever ideas I had yesterday was +completely off the off like wrong + + align:start position:0% +completely off the off like wrong + + + align:start position:0% +completely off the off like wrong +180 degrees in the wrong direction I + + align:start position:0% +180 degrees in the wrong direction I + + + align:start position:0% +180 degrees in the wrong direction I +mean do take what they say with a grain + + align:start position:0% +mean do take what they say with a grain + + + align:start position:0% +mean do take what they say with a grain +of salt um sixth graders don't always + + align:start position:0% +of salt um sixth graders don't always + + + align:start position:0% +of salt um sixth graders don't always +know how to articulate what they want + + align:start position:0% +know how to articulate what they want + + + align:start position:0% +know how to articulate what they want +and um in a pitch robots always sound + + align:start position:0% +and um in a pitch robots always sound + + + align:start position:0% +and um in a pitch robots always sound +cooler than food decomposing but there + + align:start position:0% +cooler than food decomposing but there + + + align:start position:0% +cooler than food decomposing but there +is a way to make that awesome if that's + + align:start position:0% +is a way to make that awesome if that's + + + align:start position:0% +is a way to make that awesome if that's +really what you're interested in so as + + align:start position:0% +really what you're interested in so as + + + align:start position:0% +really what you're interested in so as +with everything in this class the + + align:start position:0% +with everything in this class the + + + align:start position:0% +with everything in this class the +feedback is ultimately for you to decide + + align:start position:0% +feedback is ultimately for you to decide + + + align:start position:0% +feedback is ultimately for you to decide +what to do with it + + align:start position:0% +what to do with it + + + align:start position:0% +what to do with it +was there anything surprising that came + + align:start position:0% +was there anything surprising that came + + + align:start position:0% +was there anything surprising that came +out of the first + + align:start position:0% + + + + align:start position:0% + +hour I know it's hard to put yourself + + align:start position:0% +hour I know it's hard to put yourself + + + align:start position:0% +hour I know it's hard to put yourself +back into that perspective that's what I + + align:start position:0% +back into that perspective that's what I + + + align:start position:0% +back into that perspective that's what I +meant yesterday with the whole um + + align:start position:0% +meant yesterday with the whole um + + + align:start position:0% +meant yesterday with the whole um +thoughtfulness quality one of the values + + align:start position:0% +thoughtfulness quality one of the values + + + align:start position:0% +thoughtfulness quality one of the values +of the class is being able to take + + align:start position:0% +of the class is being able to take + + + align:start position:0% +of the class is being able to take +yourself out of the perspective that you + + align:start position:0% +yourself out of the perspective that you + + + align:start position:0% +yourself out of the perspective that you +have here we were shooting science out + + align:start position:0% +have here we were shooting science out + + + align:start position:0% +have here we were shooting science out +loud during the first season with two + + align:start position:0% +loud during the first season with two + + + align:start position:0% +loud during the first season with two +grad students who are in Aero Astro and + + align:start position:0% +grad students who are in Aero Astro and + + + align:start position:0% +grad students who are in Aero Astro and +they were making a video about how + + align:start position:0% +they were making a video about how + + + align:start position:0% +they were making a video about how +engines work and we were discussing one + + align:start position:0% +engines work and we were discussing one + + + align:start position:0% +engines work and we were discussing one +of the scenes that they had planned was + + align:start position:0% +of the scenes that they had planned was + + + align:start position:0% +of the scenes that they had planned was +to describe a turban engine and I'll go + + align:start position:0% +to describe a turban engine and I'll go + + + align:start position:0% +to describe a turban engine and I'll go +into this more during Thursday's + + align:start position:0% +into this more during Thursday's + + + align:start position:0% +into this more during Thursday's +lecture but um one of the students was + + align:start position:0% +lecture but um one of the students was + + + align:start position:0% +lecture but um one of the students was +trying to describe that it's it's the + + align:start position:0% +trying to describe that it's it's the + + + align:start position:0% +trying to describe that it's it's the +turbine blades that push the air forward + + align:start position:0% +turbine blades that push the air forward + + + align:start position:0% +turbine blades that push the air forward +and we he was thinking to do an + + align:start position:0% +and we he was thinking to do an + + + align:start position:0% +and we he was thinking to do an +animation with it and we thought this is + + align:start position:0% +animation with it and we thought this is + + + align:start position:0% +animation with it and we thought this is +really complicated I I couldn't + + align:start position:0% +really complicated I I couldn't + + + align:start position:0% +really complicated I I couldn't +understand what he was trying to say and + + align:start position:0% +understand what he was trying to say and + + + align:start position:0% +understand what he was trying to say and +finally the other student who was there + + align:start position:0% +finally the other student who was there + + + align:start position:0% +finally the other student who was there +was like oh well there's that one Boeing + + align:start position:0% +was like oh well there's that one Boeing + + + align:start position:0% +was like oh well there's that one Boeing +SE trip 7 in The Hanger in in that + + align:start position:0% +SE trip 7 in The Hanger in in that + + + align:start position:0% +SE trip 7 in The Hanger in in that +building over there like is it worth + + align:start position:0% +building over there like is it worth + + + align:start position:0% +building over there like is it worth +filming with it um and just sort of that + + align:start position:0% +filming with it um and just sort of that + + + align:start position:0% +filming with it um and just sort of that +mentality of like you have access to an + + align:start position:0% +mentality of like you have access to an + + + align:start position:0% +mentality of like you have access to an +actual turban engine and it didn't cross + + align:start position:0% +actual turban engine and it didn't cross + + + align:start position:0% +actual turban engine and it didn't cross +your mind to film it I mean they were + + align:start position:0% +your mind to film it I mean they were + + + align:start position:0% +your mind to film it I mean they were +awesome to work with and I you know that + + align:start position:0% +awesome to work with and I you know that + + + align:start position:0% +awesome to work with and I you know that +that whole day of shooting was actually + + align:start position:0% +that whole day of shooting was actually + + + align:start position:0% +that whole day of shooting was actually +really fun um but the ability to take + + align:start position:0% +really fun um but the ability to take + + + align:start position:0% +really fun um but the ability to take +yourself out of the things that you + + align:start position:0% +yourself out of the things that you + + + align:start position:0% +yourself out of the things that you +experience all the time or take for + + align:start position:0% +experience all the time or take for + + + align:start position:0% +experience all the time or take for +granted creating that window for people + + align:start position:0% +granted creating that window for people + + + align:start position:0% +granted creating that window for people +who don't necessarily have access to the + + align:start position:0% +who don't necessarily have access to the + + + align:start position:0% +who don't necessarily have access to the +world that you live in um is + + align:start position:0% +world that you live in um is + + + align:start position:0% +world that you live in um is +surprisingly difficult to do and + + align:start position:0% +surprisingly difficult to do and + + + align:start position:0% +surprisingly difficult to do and +hopefully the first hour of class has + + align:start position:0% +hopefully the first hour of class has + + + align:start position:0% +hopefully the first hour of class has +sort of helped you Orient into that New + + align:start position:0% +sort of helped you Orient into that New + + + align:start position:0% +sort of helped you Orient into that New +Perspective but I know that's a + + align:start position:0% +Perspective but I know that's a + + + align:start position:0% +Perspective but I know that's a +challenge for me A lot of times is I I + + align:start position:0% +challenge for me A lot of times is I I + + + align:start position:0% +challenge for me A lot of times is I I +don't think people are going to think + + align:start position:0% +don't think people are going to think + + + align:start position:0% +don't think people are going to think +this is super interesting and it's not + + align:start position:0% +this is super interesting and it's not + + + align:start position:0% +this is super interesting and it's not +the content that's not interesting to + + align:start position:0% +the content that's not interesting to + + + align:start position:0% +the content that's not interesting to +people it's just the delivery um how you + + align:start position:0% +people it's just the delivery um how you + + + align:start position:0% +people it's just the delivery um how you +package it + + align:start position:0% +package it + + + align:start position:0% +package it +up what I think that getting the right + + align:start position:0% +up what I think that getting the right + + + align:start position:0% +up what I think that getting the right +angle for like some of you guys had + + align:start position:0% +angle for like some of you guys had + + + align:start position:0% +angle for like some of you guys had +really broad topics right and that the + + align:start position:0% +really broad topics right and that the + + + align:start position:0% +really broad topics right and that the +thing that's really hard is that there + + align:start position:0% +thing that's really hard is that there + + + align:start position:0% +thing that's really hard is that there +are so many things within that topic + + align:start position:0% +are so many things within that topic + + + align:start position:0% +are so many things within that topic +that could be really interesting and + + align:start position:0% +that could be really interesting and + + + align:start position:0% +that could be really interesting and +like the food the food decomposing thing + + align:start position:0% +like the food the food decomposing thing + + + align:start position:0% +like the food the food decomposing thing +I actually think there are a billion + + align:start position:0% +I actually think there are a billion + + + align:start position:0% +I actually think there are a billion +really cool topics in there that could + + align:start position:0% +really cool topics in there that could + + + align:start position:0% +really cool topics in there that could +be really fun like cheese is technically + + align:start position:0% +be really fun like cheese is technically + + + align:start position:0% +be really fun like cheese is technically +mold and why is some mold good and some + + align:start position:0% +mold and why is some mold good and some + + + align:start position:0% +mold and why is some mold good and some +mold bad right and there's some really + + align:start position:0% +mold bad right and there's some really + + + align:start position:0% +mold bad right and there's some really +cool things like that you can do about + + align:start position:0% +cool things like that you can do about + + + align:start position:0% +cool things like that you can do about +that and and um microb back getting back + + align:start position:0% +that and and um microb back getting back + + + align:start position:0% +that and and um microb back getting back +to microbiome things or bacteria or you + + align:start position:0% +to microbiome things or bacteria or you + + + align:start position:0% +to microbiome things or bacteria or you +know there's some really cool stuff in + + align:start position:0% +know there's some really cool stuff in + + + align:start position:0% +know there's some really cool stuff in +there and just like every one of your + + align:start position:0% +there and just like every one of your + + + align:start position:0% +there and just like every one of your +topics that you guys brought up there's + + align:start position:0% +topics that you guys brought up there's + + + align:start position:0% +topics that you guys brought up there's +a there's some really cool little pieces + + align:start position:0% +a there's some really cool little pieces + + + align:start position:0% +a there's some really cool little pieces +of truths inside of there and the hard + + align:start position:0% +of truths inside of there and the hard + + + align:start position:0% +of truths inside of there and the hard +part is figuring out how to give I mean + + align:start position:0% +part is figuring out how to give I mean + + + align:start position:0% +part is figuring out how to give I mean +this is what Writers Do is having the + + align:start position:0% +this is what Writers Do is having the + + + align:start position:0% +this is what Writers Do is having the +right angle to your story right and so + + align:start position:0% +right angle to your story right and so + + + align:start position:0% +right angle to your story right and so +many I think all of when I heard I heard + + align:start position:0% +many I think all of when I heard I heard + + + align:start position:0% +many I think all of when I heard I heard +many of your your ideas like we're in + + align:start position:0% +many of your your ideas like we're in + + + align:start position:0% +many of your your ideas like we're in +the right zip code but we haven't quite + + align:start position:0% +the right zip code but we haven't quite + + + align:start position:0% +the right zip code but we haven't quite +narrowed down on the right building yet + + align:start position:0% +narrowed down on the right building yet + + + align:start position:0% +narrowed down on the right building yet +right or the right Street and so the + + align:start position:0% +right or the right Street and so the + + + align:start position:0% +right or the right Street and so the +hard part is figuring out within the + + align:start position:0% +hard part is figuring out within the + + + align:start position:0% +hard part is figuring out within the +topic of ship building or within the + + align:start position:0% +topic of ship building or within the + + + align:start position:0% +topic of ship building or within the +idea of hacking or building a game what + + align:start position:0% +idea of hacking or building a game what + + + align:start position:0% +idea of hacking or building a game what +is that little cool angle that you're + + align:start position:0% +is that little cool angle that you're + + + align:start position:0% +is that little cool angle that you're +going to take to make it really exciting + + align:start position:0% +going to take to make it really exciting + + + align:start position:0% +going to take to make it really exciting +and interesting and snar enough and + + align:start position:0% +and interesting and snar enough and + + + align:start position:0% +and interesting and snar enough and +focused enough and that kind of thing + + align:start position:0% +focused enough and that kind of thing + + + align:start position:0% +focused enough and that kind of thing +that makes it really interesting because + + align:start position:0% +that makes it really interesting because + + + align:start position:0% +that makes it really interesting because +I I do think actually that that lava + + align:start position:0% +I I do think actually that that lava + + + align:start position:0% +I I do think actually that that lava +sounds cooler to like a sixth grader + + align:start position:0% +sounds cooler to like a sixth grader + + + align:start position:0% +sounds cooler to like a sixth grader +because they're like lava that's cool + + align:start position:0% +because they're like lava that's cool + + + align:start position:0% +because they're like lava that's cool +right but but the food one I'm not ready + + align:start position:0% +right but but the food one I'm not ready + + + align:start position:0% +right but but the food one I'm not ready +to give up on that yet like I think + + align:start position:0% +to give up on that yet like I think + + + align:start position:0% +to give up on that yet like I think +there's a lot of cool stuff in there and + + align:start position:0% +there's a lot of cool stuff in there and + + + align:start position:0% +there's a lot of cool stuff in there and +the hard part is figuring out you know + + align:start position:0% +the hard part is figuring out you know + + + align:start position:0% +the hard part is figuring out you know +really narrowing down your story and + + align:start position:0% +really narrowing down your story and + + + align:start position:0% +really narrowing down your story and +then figuring out which one has more + + align:start position:0% +then figuring out which one has more + + + align:start position:0% +then figuring out which one has more +meat to it I mean I think it's a very + + align:start position:0% +meat to it I mean I think it's a very + + + align:start position:0% +meat to it I mean I think it's a very +beautiful story actually the whole idea + + align:start position:0% +beautiful story actually the whole idea + + + align:start position:0% +beautiful story actually the whole idea +of material objects on this Earth + + align:start position:0% +of material objects on this Earth + + + align:start position:0% +of material objects on this Earth +transforming in a way that's tangible to + + align:start position:0% +transforming in a way that's tangible to + + + align:start position:0% +transforming in a way that's tangible to +us and like maybe that's just like super + + align:start position:0% +us and like maybe that's just like super + + + align:start position:0% +us and like maybe that's just like super +romantic sounding but um I do think that + + align:start position:0% +romantic sounding but um I do think that + + + align:start position:0% +romantic sounding but um I do think that +there is I loved what Chris said + + align:start position:0% +there is I loved what Chris said + + + align:start position:0% +there is I loved what Chris said +yesterday about making not just the + + align:start position:0% +yesterday about making not just the + + + align:start position:0% +yesterday about making not just the +unfamiliar familiar but making the + + align:start position:0% +unfamiliar familiar but making the + + + align:start position:0% +unfamiliar familiar but making the +familiar unfamiliar and I think that's a + + align:start position:0% +familiar unfamiliar and I think that's a + + + align:start position:0% +familiar unfamiliar and I think that's a +lot of what Vsauce does and I think + + align:start position:0% +lot of what Vsauce does and I think + + + align:start position:0% +lot of what Vsauce does and I think +that's a lot of what veritasium does is + + align:start position:0% +that's a lot of what veritasium does is + + + align:start position:0% +that's a lot of what veritasium does is +it's taking um the things that you see + + align:start position:0% +it's taking um the things that you see + + + align:start position:0% +it's taking um the things that you see +and taking the world that you're used to + + align:start position:0% +and taking the world that you're used to + + + align:start position:0% +and taking the world that you're used to +seeing and showing you a new lens at + + align:start position:0% +seeing and showing you a new lens at + + + align:start position:0% +seeing and showing you a new lens at +looking at it um and I know that sounds + + align:start position:0% +looking at it um and I know that sounds + + + align:start position:0% +looking at it um and I know that sounds +very abstract and I'm sure that we've + + align:start position:0% +very abstract and I'm sure that we've + + + align:start position:0% +very abstract and I'm sure that we've +thrown out a lot of things to think + + align:start position:0% +thrown out a lot of things to think + + + align:start position:0% +thrown out a lot of things to think +about that you're not maybe quite sure + + align:start position:0% +about that you're not maybe quite sure + + + align:start position:0% +about that you're not maybe quite sure +how to implement on a practical level + + align:start position:0% +how to implement on a practical level + + + align:start position:0% +how to implement on a practical level +and I promise that that's what we're + + align:start position:0% +and I promise that that's what we're + + + align:start position:0% +and I promise that that's what we're +going to hit next um and once you guys + + align:start position:0% +going to hit next um and once you guys + + + align:start position:0% +going to hit next um and once you guys +write a script tonight or just try + + align:start position:0% +write a script tonight or just try + + + align:start position:0% +write a script tonight or just try +writing it at it'll help you a lot to + + align:start position:0% +writing it at it'll help you a lot to + + + align:start position:0% +writing it at it'll help you a lot to +sort of understand how to implement + + align:start position:0% +sort of understand how to implement + + + align:start position:0% +sort of understand how to implement +these things practically speaking um so + + align:start position:0% +these things practically speaking um so + + + align:start position:0% +these things practically speaking um so +don't worry I am aware that that that + + align:start position:0% +don't worry I am aware that that that + + + align:start position:0% +don't worry I am aware that that that +might be a frustration you have I wonder + + align:start position:0% +might be a frustration you have I wonder + + + align:start position:0% +might be a frustration you have I wonder +if we have a little time today to give + + align:start position:0% +if we have a little time today to give + + + align:start position:0% +if we have a little time today to give +them more time to flesh out their ideas + + align:start position:0% +them more time to flesh out their ideas + + + align:start position:0% +them more time to flesh out their ideas +a little bit oh yeah absolutely so um I + + align:start position:0% +a little bit oh yeah absolutely so um I + + + align:start position:0% +a little bit oh yeah absolutely so um I +was originally planning on showing you + + align:start position:0% +was originally planning on showing you + + + align:start position:0% +was originally planning on showing you +guys uh a couple hosting case studies + + align:start position:0% +guys uh a couple hosting case studies + + + align:start position:0% +guys uh a couple hosting case studies +but if you would find it more helpful to + + align:start position:0% +but if you would find it more helpful to + + + align:start position:0% +but if you would find it more helpful to +just maybe brainstorm script ideas I + + align:start position:0% +just maybe brainstorm script ideas I + + + align:start position:0% +just maybe brainstorm script ideas I +feel like that's where they are right + + align:start position:0% +feel like that's where they are right + + + align:start position:0% +feel like that's where they are right +now if I'm wrong but I feel like today + + align:start position:0% +now if I'm wrong but I feel like today + + + align:start position:0% +now if I'm wrong but I feel like today +maybe you think a little more and now + + align:start position:0% +maybe you think a little more and now + + + align:start position:0% +maybe you think a little more and now +before you go home and have to really + + align:start position:0% +before you go home and have to really + + + align:start position:0% +before you go home and have to really +Implement some idea maybe it's worth + + align:start position:0% +Implement some idea maybe it's worth + + + align:start position:0% +Implement some idea maybe it's worth +really making sure each of you knows + + align:start position:0% +really making sure each of you knows + + + align:start position:0% +really making sure each of you knows +what you want to do before I don't know + + align:start position:0% +what you want to do before I don't know + + + align:start position:0% +what you want to do before I don't know +what do you guys think I'm feeling I'm + + align:start position:0% +what do you guys think I'm feeling I'm + + + align:start position:0% +what do you guys think I'm feeling I'm +feeling some anxiety right now that like + + align:start position:0% +feeling some anxiety right now that like + + + align:start position:0% +feeling some anxiety right now that like +it would help to flush your ideas a + + align:start position:0% +it would help to flush your ideas a + + + align:start position:0% +it would help to flush your ideas a +little more yes okay we will totally do + + align:start position:0% +little more yes okay we will totally do + + + align:start position:0% +little more yes okay we will totally do +that um I did want to show you something + + align:start position:0% +that um I did want to show you something + + + align:start position:0% +that um I did want to show you something +cuz I for me personally it's hard for me + + align:start position:0% +cuz I for me personally it's hard for me + + + align:start position:0% +cuz I for me personally it's hard for me +to hear abstract level ideas and and I + + align:start position:0% +to hear abstract level ideas and and I + + + align:start position:0% +to hear abstract level ideas and and I +just need to see an example to help + + align:start position:0% +just need to see an example to help + + + align:start position:0% +just need to see an example to help +um understand that so and again I'm not + + align:start position:0% +um understand that so and again I'm not + + + align:start position:0% +um understand that so and again I'm not +saying that the way I necessarily do + + align:start position:0% +saying that the way I necessarily do + + + align:start position:0% +saying that the way I necessarily do +things or the way um George or any of + + align:start position:0% +things or the way um George or any of + + + align:start position:0% +things or the way um George or any of +the teaching staff do things is + + align:start position:0% +the teaching staff do things is + + + align:start position:0% +the teaching staff do things is +necessarily the best way because again + + align:start position:0% +necessarily the best way because again + + + align:start position:0% +necessarily the best way because again +best has not really been defined um but + + align:start position:0% +best has not really been defined um but + + + align:start position:0% +best has not really been defined um but +this was a video we did during second + + align:start position:0% +this was a video we did during second + + + align:start position:0% +this was a video we did during second +season and it was the first biology + + align:start position:0% +season and it was the first biology + + + align:start position:0% +season and it was the first biology +video that any of us had worked on which + + align:start position:0% +video that any of us had worked on which + + + align:start position:0% +video that any of us had worked on which +I was really excited about but it did + + align:start position:0% +I was really excited about but it did + + + align:start position:0% +I was really excited about but it did +present these challenges of like how do + + align:start position:0% +present these challenges of like how do + + + align:start position:0% +present these challenges of like how do +you create uh a visually interesting + + align:start position:0% +you create uh a visually interesting + + + align:start position:0% +you create uh a visually interesting +video that's worth making as a video + + align:start position:0% +video that's worth making as a video + + + align:start position:0% +video that's worth making as a video +because again I mean I think asking + + align:start position:0% +because again I mean I think asking + + + align:start position:0% +because again I mean I think asking +yourself like why do I need to make an + + align:start position:0% +yourself like why do I need to make an + + + align:start position:0% +yourself like why do I need to make an +animation about synthetic biology when I + + align:start position:0% +animation about synthetic biology when I + + + align:start position:0% +animation about synthetic biology when I +could just create um a cartoon about it + + align:start position:0% +could just create um a cartoon about it + + + align:start position:0% +could just create um a cartoon about it +you know as Chris was saying visual + + align:start position:0% +you know as Chris was saying visual + + + align:start position:0% +you know as Chris was saying visual +elements just pictoral representations + + align:start position:0% +elements just pictoral representations + + + align:start position:0% +elements just pictoral representations +of things are very very engaging um we + + align:start position:0% +of things are very very engaging um we + + + align:start position:0% +of things are very very engaging um we +really were asking ourselves like what's + + align:start position:0% +really were asking ourselves like what's + + + align:start position:0% +really were asking ourselves like what's +going to be the visual purpose of her + + align:start position:0% +going to be the visual purpose of her + + + align:start position:0% +going to be the visual purpose of her +explaining um what basically became a + + align:start position:0% +explaining um what basically became a + + + align:start position:0% +explaining um what basically became a +little bit about systems biology + + align:start position:0% +little bit about systems biology + + + align:start position:0% +little bit about systems biology +actually um and one of the things that + + align:start position:0% +actually um and one of the things that + + + align:start position:0% +actually um and one of the things that +we really fixated on which is an idea of + + align:start position:0% +we really fixated on which is an idea of + + + align:start position:0% +we really fixated on which is an idea of +hers was a metaphor and so this is about + + align:start position:0% +hers was a metaphor and so this is about + + + align:start position:0% +hers was a metaphor and so this is about +a 4 minute long episode would you guys + + align:start position:0% +a 4 minute long episode would you guys + + + align:start position:0% +a 4 minute long episode would you guys +mind if I showed it um and then we can + + align:start position:0% +mind if I showed it um and then we can + + + align:start position:0% +mind if I showed it um and then we can +Workshop script but let me turn off + + align:start position:0% + + + + align:start position:0% + +this oh is the light already off you + + align:start position:0% +this oh is the light already off you + + + align:start position:0% +this oh is the light already off you +guys can see it okay right okay + + align:start position:0% + + + + align:start position:0% + +so I'll show this to you guys and maybe + + align:start position:0% +so I'll show this to you guys and maybe + + + align:start position:0% +so I'll show this to you guys and maybe +we can + + align:start position:0% +we can + + + align:start position:0% +we can +unpack what you think is successful or + + align:start position:0% +unpack what you think is successful or + + + align:start position:0% +unpack what you think is successful or +not successful about our attempt is a + + align:start position:0% +not successful about our attempt is a + + + align:start position:0% +not successful about our attempt is a +compound that can treat + + align:start position:0% +compound that can treat + + + align:start position:0% +compound that can treat +cancer pxil is a compound that can treat + + align:start position:0% +cancer pxil is a compound that can treat + + + align:start position:0% +cancer pxil is a compound that can treat +cancer salicylic acid reduces headaches + + align:start position:0% +cancer salicylic acid reduces headaches + + + align:start position:0% +cancer salicylic acid reduces headaches +and fevers carotenoids can turn your + + align:start position:0% +and fevers carotenoids can turn your + + + align:start position:0% +and fevers carotenoids can turn your +skin orange and miraculine changes your + + align:start position:0% +skin orange and miraculine changes your + + + align:start position:0% +skin orange and miraculine changes your +sense of taste what do all of these + + align:start position:0% +sense of taste what do all of these + + + align:start position:0% +sense of taste what do all of these +awesome compounds have in common they + + align:start position:0% +awesome compounds have in common they + + + align:start position:0% +awesome compounds have in common they +all come from plants + + align:start position:0% +all come from plants + + + align:start position:0% +all come from plants +[Music] + + align:start position:0% + + + + align:start position:0% + +more than 100,000 natural compounds + + align:start position:0% +more than 100,000 natural compounds + + + align:start position:0% +more than 100,000 natural compounds +occur in plants and we barely explored + + align:start position:0% +occur in plants and we barely explored + + + align:start position:0% +occur in plants and we barely explored +them these small molecules are called + + align:start position:0% +them these small molecules are called + + + align:start position:0% +them these small molecules are called +metabolites just like how all of the DNA + + align:start position:0% +metabolites just like how all of the DNA + + + align:start position:0% +metabolites just like how all of the DNA +in an organism forms the genome all of + + align:start position:0% +in an organism forms the genome all of + + + align:start position:0% +in an organism forms the genome all of +the metabolites form the metabolome even + + align:start position:0% +the metabolites form the metabolome even + + + align:start position:0% +the metabolites form the metabolome even +though each metabol can be made from + + align:start position:0% +though each metabol can be made from + + + align:start position:0% +though each metabol can be made from +only six elements there are so many + + align:start position:0% +only six elements there are so many + + + align:start position:0% +only six elements there are so many +possibilities that it would take + + align:start position:0% +possibilities that it would take + + + align:start position:0% +possibilities that it would take +scientists thousands of years to make + + align:start position:0% +scientists thousands of years to make + + + align:start position:0% +scientists thousands of years to make +each one and figure out its + + align:start position:0% +each one and figure out its + + + align:start position:0% +each one and figure out its +usefulness luckily plants have already + + align:start position:0% +usefulness luckily plants have already + + + align:start position:0% +usefulness luckily plants have already +done this for us plants have the + + align:start position:0% +done this for us plants have the + + + align:start position:0% +done this for us plants have the +disadvantage of being rooted to the + + align:start position:0% +disadvantage of being rooted to the + + + align:start position:0% +disadvantage of being rooted to the +ground so over time they've trial and + + align:start position:0% +ground so over time they've trial and + + + align:start position:0% +ground so over time they've trial and +aired making lots of compounds to see + + align:start position:0% +aired making lots of compounds to see + + + align:start position:0% +aired making lots of compounds to see +which ones help them survive and thrive + + align:start position:0% +which ones help them survive and thrive + + + align:start position:0% +which ones help them survive and thrive +best and because they've been + + align:start position:0% +best and because they've been + + + align:start position:0% +best and because they've been +interacting with other species like us + + align:start position:0% +interacting with other species like us + + + align:start position:0% +interacting with other species like us +for hundreds of thousands of years some + + align:start position:0% +for hundreds of thousands of years some + + + align:start position:0% +for hundreds of thousands of years some +of their chemicals turn out to be really + + align:start position:0% +of their chemicals turn out to be really + + + align:start position:0% +of their chemicals turn out to be really +useful both inside and outside our + + align:start position:0% +useful both inside and outside our + + + align:start position:0% +useful both inside and outside our +bodies but to use plants to their full + + align:start position:0% +bodies but to use plants to their full + + + align:start position:0% +bodies but to use plants to their full +potential we have to know what chemicals + + align:start position:0% +potential we have to know what chemicals + + + align:start position:0% +potential we have to know what chemicals +they make and how they make them instead + + align:start position:0% +they make and how they make them instead + + + align:start position:0% +they make and how they make them instead +of studying Every chemical one by one + + align:start position:0% +of studying Every chemical one by one + + + align:start position:0% +of studying Every chemical one by one +what if we could study all of them at + + align:start position:0% +what if we could study all of them at + + + align:start position:0% +what if we could study all of them at +once we could start by mapping the huge + + align:start position:0% +once we could start by mapping the huge + + + align:start position:0% +once we could start by mapping the huge +Network that connects metabolites in any + + align:start position:0% +Network that connects metabolites in any + + + align:start position:0% +Network that connects metabolites in any +living organism molecules are always on + + align:start position:0% +living organism molecules are always on + + + align:start position:0% +living organism molecules are always on +the Move being converted and shuttled + + align:start position:0% +the Move being converted and shuttled + + + align:start position:0% +the Move being converted and shuttled +decomposed and built back up again and + + align:start position:0% +decomposed and built back up again and + + + align:start position:0% +decomposed and built back up again and +reused it's just like a subway system + + align:start position:0% +reused it's just like a subway system + + + align:start position:0% +reused it's just like a subway system +except in biology the people are the + + align:start position:0% +except in biology the people are the + + + align:start position:0% +except in biology the people are the +chemical and the train is the enzyme + + align:start position:0% +chemical and the train is the enzyme + + + align:start position:0% +chemical and the train is the enzyme +that converts and moves them if you look + + align:start position:0% +that converts and moves them if you look + + + align:start position:0% +that converts and moves them if you look +at a city from above How Could You map + + align:start position:0% +at a city from above How Could You map + + + align:start position:0% +at a city from above How Could You map +the whole subway + + align:start position:0% +the whole subway + + + align:start position:0% +the whole subway +system similarly if we look at a plant + + align:start position:0% +system similarly if we look at a plant + + + align:start position:0% +system similarly if we look at a plant +how can we figure out the entire + + align:start position:0% +how can we figure out the entire + + + align:start position:0% +how can we figure out the entire +metabolome + + align:start position:0% +metabolome + + + align:start position:0% +metabolome +network to figure out a path in a system + + align:start position:0% +network to figure out a path in a system + + + align:start position:0% +network to figure out a path in a system +what we actually need to do is break it + + align:start position:0% +what we actually need to do is break it + + + align:start position:0% +what we actually need to do is break it +if we mutate or disrupt a pathway and + + align:start position:0% +if we mutate or disrupt a pathway and + + + align:start position:0% +if we mutate or disrupt a pathway and +see how the metabolic quantities change + + align:start position:0% +see how the metabolic quantities change + + + align:start position:0% +see how the metabolic quantities change +we can figure out the connections + + align:start position:0% +we can figure out the connections + + + align:start position:0% +we can figure out the connections +between + + align:start position:0% +between + + + align:start position:0% +between +them let's say the train from Central to + + align:start position:0% +them let's say the train from Central to + + + align:start position:0% +them let's say the train from Central to +m breaks we wouldn't see students + + align:start position:0% +m breaks we wouldn't see students + + + align:start position:0% +m breaks we wouldn't see students +arriving at MIT and would instead see + + align:start position:0% +arriving at MIT and would instead see + + + align:start position:0% +arriving at MIT and would instead see +them building up at Central but not only + + align:start position:0% +them building up at Central but not only + + + align:start position:0% +them building up at Central but not only +that anyone else traveling along the red + + align:start position:0% +that anyone else traveling along the red + + + align:start position:0% +that anyone else traveling along the red +line would also be affected so it's the + + align:start position:0% +line would also be affected so it's the + + + align:start position:0% +line would also be affected so it's the +redistribution of people which reveals + + align:start position:0% +redistribution of people which reveals + + + align:start position:0% +redistribution of people which reveals +the redline Subway path and tells us + + align:start position:0% +the redline Subway path and tells us + + + align:start position:0% +the redline Subway path and tells us +where the train + + align:start position:0% +where the train + + + align:start position:0% +where the train +broke we can use this system's thinking + + align:start position:0% +broke we can use this system's thinking + + + align:start position:0% +broke we can use this system's thinking +to uncover the plant metabolite Network + + align:start position:0% +to uncover the plant metabolite Network + + + align:start position:0% +to uncover the plant metabolite Network +for example we know about a compound + + align:start position:0% +for example we know about a compound + + + align:start position:0% +for example we know about a compound +called cipo myate which protects the + + align:start position:0% +called cipo myate which protects the + + + align:start position:0% +called cipo myate which protects the +plant from UV damage by interacting with + + align:start position:0% +plant from UV damage by interacting with + + + align:start position:0% +plant from UV damage by interacting with +UV light making the the plant glow green + + align:start position:0% +UV light making the the plant glow green + + + align:start position:0% +UV light making the the plant glow green +but without it the plant would glow red + + align:start position:0% +but without it the plant would glow red + + + align:start position:0% +but without it the plant would glow red +so if we see a red plant it's like + + align:start position:0% +so if we see a red plant it's like + + + align:start position:0% +so if we see a red plant it's like +seeing no people at the cipate station + + align:start position:0% +seeing no people at the cipate station + + + align:start position:0% +seeing no people at the cipate station +but we wouldn't yet know where the train + + align:start position:0% +but we wouldn't yet know where the train + + + align:start position:0% +but we wouldn't yet know where the train +broke or what other stations are along + + align:start position:0% +broke or what other stations are along + + + align:start position:0% +broke or what other stations are along +the route to do that we can mutate a lot + + align:start position:0% +the route to do that we can mutate a lot + + + align:start position:0% +the route to do that we can mutate a lot +of the seeds plant them and choose the + + align:start position:0% +of the seeds plant them and choose the + + + align:start position:0% +of the seeds plant them and choose the +red + + align:start position:0% +red + + + align:start position:0% +red +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +ones now we can analyze these samples by + + align:start position:0% +ones now we can analyze these samples by + + + align:start position:0% +ones now we can analyze these samples by +using the mass spectrometer + + align:start position:0% + + + + align:start position:0% + +it measures how much of each metabolite + + align:start position:0% +it measures how much of each metabolite + + + align:start position:0% +it measures how much of each metabolite +is present in the sample then we can use + + align:start position:0% +is present in the sample then we can use + + + align:start position:0% +is present in the sample then we can use +a program to see which compounds were + + align:start position:0% +a program to see which compounds were + + + align:start position:0% +a program to see which compounds were +affected and map that part of the + + align:start position:0% +affected and map that part of the + + + align:start position:0% +affected and map that part of the +network it's like revealing the red + + align:start position:0% +network it's like revealing the red + + + align:start position:0% +network it's like revealing the red +line once we figure out how the entire + + align:start position:0% +line once we figure out how the entire + + + align:start position:0% +line once we figure out how the entire +metabim works we can use it to engineer + + align:start position:0% +metabim works we can use it to engineer + + + align:start position:0% +metabim works we can use it to engineer +plants to create new biomaterials + + align:start position:0% +plants to create new biomaterials + + + align:start position:0% +plants to create new biomaterials +medicines and clean energy we might even + + align:start position:0% +medicines and clean energy we might even + + + align:start position:0% +medicines and clean energy we might even +discover that plants have the secret to + + align:start position:0% +discover that plants have the secret to + + + align:start position:0% +discover that plants have the secret to +living forever we just need to unlock + + align:start position:0% +living forever we just need to unlock + + + align:start position:0% +living forever we just need to unlock +their chemical Mysteries + + align:start position:0% +their chemical Mysteries + + + align:start position:0% +their chemical Mysteries +[Music] + + align:start position:0% + + + + align:start position:0% + +so Anastasia's topic was + + align:start position:0% +so Anastasia's topic was + + + align:start position:0% +so Anastasia's topic was +um it was really hard to visualize I + + align:start position:0% +um it was really hard to visualize I + + + align:start position:0% +um it was really hard to visualize I +mean if you can imagine when our first + + align:start position:0% +mean if you can imagine when our first + + + align:start position:0% +mean if you can imagine when our first +meeting she was talking about basically + + align:start position:0% +meeting she was talking about basically + + + align:start position:0% +meeting she was talking about basically +mapping chemical Pathways in in plants + + align:start position:0% +mapping chemical Pathways in in plants + + + align:start position:0% +mapping chemical Pathways in in plants +and it's a hard concept to describe + + align:start position:0% +and it's a hard concept to describe + + + align:start position:0% +and it's a hard concept to describe +verbally and um and I think that there + + align:start position:0% +verbally and um and I think that there + + + align:start position:0% +verbally and um and I think that there +are some things that we did well with + + align:start position:0% +are some things that we did well with + + + align:start position:0% +are some things that we did well with +that video I still feel like sometimes + + align:start position:0% +that video I still feel like sometimes + + + align:start position:0% +that video I still feel like sometimes +it's easy to get lost in the metaphor um + + align:start position:0% +it's easy to get lost in the metaphor um + + + align:start position:0% +it's easy to get lost in the metaphor um +that it doesn't really do you know as + + align:start position:0% +that it doesn't really do you know as + + + align:start position:0% +that it doesn't really do you know as +precise of a job as it could um one of + + align:start position:0% +precise of a job as it could um one of + + + align:start position:0% +precise of a job as it could um one of +the things I did want to hit though cuz + + align:start position:0% +the things I did want to hit though cuz + + + align:start position:0% +the things I did want to hit though cuz +someone had asked you know how do you + + align:start position:0% +someone had asked you know how do you + + + align:start position:0% +someone had asked you know how do you +know if your idea is too was it you who + + align:start position:0% +know if your idea is too was it you who + + + align:start position:0% +know if your idea is too was it you who +had asked how do you know if your idea + + align:start position:0% +had asked how do you know if your idea + + + align:start position:0% +had asked how do you know if your idea +is too big or not + + align:start position:0% +is too big or not + + + align:start position:0% +is too big or not +um you're not going to appeal to + + align:start position:0% +um you're not going to appeal to + + + align:start position:0% +um you're not going to appeal to +everyone and you're not going to be the + + align:start position:0% +everyone and you're not going to be the + + + align:start position:0% +everyone and you're not going to be the +perfect video for every viewer and + + align:start position:0% +perfect video for every viewer and + + + align:start position:0% +perfect video for every viewer and +that's okay um I think understanding + + align:start position:0% +that's okay um I think understanding + + + align:start position:0% +that's okay um I think understanding +your Niche is one of the biggest lessons + + align:start position:0% +your Niche is one of the biggest lessons + + + align:start position:0% +your Niche is one of the biggest lessons +that I learned in producing science out + + align:start position:0% +that I learned in producing science out + + + align:start position:0% +that I learned in producing science out +loud um at the beginning Our intention + + align:start position:0% +loud um at the beginning Our intention + + + align:start position:0% +loud um at the beginning Our intention +and our goal was to be something like sa + + align:start position:0% +and our goal was to be something like sa + + + align:start position:0% +and our goal was to be something like sa +show or Vsauce uh something that kids + + align:start position:0% +show or Vsauce uh something that kids + + + align:start position:0% +show or Vsauce uh something that kids +just sort of watch on their own um and + + align:start position:0% +just sort of watch on their own um and + + + align:start position:0% +just sort of watch on their own um and +we quickly realize that that NE that + + align:start position:0% +we quickly realize that that NE that + + + align:start position:0% +we quickly realize that that NE that +won't necessarily be the case for us and + + align:start position:0% +won't necessarily be the case for us and + + + align:start position:0% +won't necessarily be the case for us and +that's okay and that we serve a very + + align:start position:0% +that's okay and that we serve a very + + + align:start position:0% +that's okay and that we serve a very +powerful function being coupled in + + align:start position:0% +powerful function being coupled in + + + align:start position:0% +powerful function being coupled in +classrooms or after school programs or + + align:start position:0% +classrooms or after school programs or + + + align:start position:0% +classrooms or after school programs or +parents watching them with their kids um + + align:start position:0% +parents watching them with their kids um + + + align:start position:0% +parents watching them with their kids um +and that'll dictate what concessions you + + align:start position:0% +and that'll dictate what concessions you + + + align:start position:0% +and that'll dictate what concessions you +might make I mean in this video we kind + + align:start position:0% +might make I mean in this video we kind + + + align:start position:0% +might make I mean in this video we kind +of just said whoever is going to watch + + align:start position:0% +of just said whoever is going to watch + + + align:start position:0% +of just said whoever is going to watch +it is going to understand a little bit + + align:start position:0% +it is going to understand a little bit + + + align:start position:0% +it is going to understand a little bit +about chemistry and biology um and that + + align:start position:0% +about chemistry and biology um and that + + + align:start position:0% +about chemistry and biology um and that +is what allowed us to sort of gloss over + + align:start position:0% +is what allowed us to sort of gloss over + + + align:start position:0% +is what allowed us to sort of gloss over +some of the the details about chemical + + align:start position:0% +some of the the details about chemical + + + align:start position:0% +some of the the details about chemical +Pathways um I think that that video + + align:start position:0% +Pathways um I think that that video + + + align:start position:0% +Pathways um I think that that video +worked for us um that there was a reason + + align:start position:0% +worked for us um that there was a reason + + + align:start position:0% +worked for us um that there was a reason +that we made that video partially + + align:start position:0% +that we made that video partially + + + align:start position:0% +that we made that video partially +because Anastasia I think is really good + + align:start position:0% +because Anastasia I think is really good + + + align:start position:0% +because Anastasia I think is really good +on screen and that if you didn't have + + align:start position:0% +on screen and that if you didn't have + + + align:start position:0% +on screen and that if you didn't have +her and if you had just a narrated video + + align:start position:0% +her and if you had just a narrated video + + + align:start position:0% +her and if you had just a narrated video +or an animation it would be a very + + align:start position:0% +or an animation it would be a very + + + align:start position:0% +or an animation it would be a very +different visual experience um I don't + + align:start position:0% +different visual experience um I don't + + + align:start position:0% +different visual experience um I don't +know if you guys agree with that or not + + align:start position:0% +know if you guys agree with that or not + + + align:start position:0% +know if you guys agree with that or not +that's that's sort of how I felt um the + + align:start position:0% +that's that's sort of how I felt um the + + + align:start position:0% +that's that's sort of how I felt um the +other thing is she naturally as a person + + align:start position:0% +other thing is she naturally as a person + + + align:start position:0% +other thing is she naturally as a person +is really like that she's like really + + align:start position:0% +is really like that she's like really + + + align:start position:0% +is really like that she's like really +jazzed about B biology um it's okay if + + align:start position:0% +jazzed about B biology um it's okay if + + + align:start position:0% +jazzed about B biology um it's okay if +your personality is not like that um but + + align:start position:0% +your personality is not like that um but + + + align:start position:0% +your personality is not like that um but +the way she wrote her script I mean she + + align:start position:0% +the way she wrote her script I mean she + + + align:start position:0% +the way she wrote her script I mean she +was probably one of the best during the + + align:start position:0% +was probably one of the best during the + + + align:start position:0% +was probably one of the best during the +day of shoot just remembering her lines + + align:start position:0% +day of shoot just remembering her lines + + + align:start position:0% +day of shoot just remembering her lines +cuz the way she wrote her script was the + + align:start position:0% +cuz the way she wrote her script was the + + + align:start position:0% +cuz the way she wrote her script was the +way that she just sort of talks about + + align:start position:0% +way that she just sort of talks about + + + align:start position:0% +way that she just sort of talks about +that stuff in real life and that was um + + align:start position:0% +that stuff in real life and that was um + + + align:start position:0% +that stuff in real life and that was um +a big tip that I wanted to give you guys + + align:start position:0% +a big tip that I wanted to give you guys + + + align:start position:0% +a big tip that I wanted to give you guys +before you started scripting was write + + align:start position:0% +before you started scripting was write + + + align:start position:0% +before you started scripting was write +things the way that you would say it and + + align:start position:0% +things the way that you would say it and + + + align:start position:0% +things the way that you would say it and +George will talk about this a lot + + align:start position:0% +George will talk about this a lot + + + align:start position:0% +George will talk about this a lot +tomorrow as well it's a very very + + align:start position:0% +tomorrow as well it's a very very + + + align:start position:0% +tomorrow as well it's a very very +obvious statement um that is very very + + align:start position:0% +obvious statement um that is very very + + + align:start position:0% +obvious statement um that is very very +difficult to implement um I don't know + + align:start position:0% +difficult to implement um I don't know + + + align:start position:0% +difficult to implement um I don't know +if you guys were paying attention to + + align:start position:0% +if you guys were paying attention to + + + align:start position:0% +if you guys were paying attention to +that in some of the biobuilder videos + + align:start position:0% +that in some of the biobuilder videos + + + align:start position:0% +that in some of the biobuilder videos +their their purpose is to be very + + align:start position:0% +their their purpose is to be very + + + align:start position:0% +their their purpose is to be very +instructional like Natalie was saying + + align:start position:0% +instructional like Natalie was saying + + + align:start position:0% +instructional like Natalie was saying +it's like a very + + align:start position:0% +it's like a very + + + align:start position:0% +it's like a very +encyclopedic type of product um and it + + align:start position:0% +encyclopedic type of product um and it + + + align:start position:0% +encyclopedic type of product um and it +works well in schools but most people + + align:start position:0% +works well in schools but most people + + + align:start position:0% +works well in schools but most people +don't talk in their everyday + + align:start position:0% +don't talk in their everyday + + + align:start position:0% +don't talk in their everyday +conversation like those characters did + + align:start position:0% +conversation like those characters did + + + align:start position:0% +conversation like those characters did +um and that's okay for their product um + + align:start position:0% +um and that's okay for their product um + + + align:start position:0% +um and that's okay for their product um +but if your intent is to engage someone + + align:start position:0% +but if your intent is to engage someone + + + align:start position:0% +but if your intent is to engage someone +like Hank Green does then you have to + + align:start position:0% +like Hank Green does then you have to + + + align:start position:0% +like Hank Green does then you have to +think about the way that you're writing + + align:start position:0% +think about the way that you're writing + + + align:start position:0% +think about the way that you're writing +your script and um again that may sound + + align:start position:0% +your script and um again that may sound + + + align:start position:0% +your script and um again that may sound +like a very abstract tip so what I would + + align:start position:0% +like a very abstract tip so what I would + + + align:start position:0% +like a very abstract tip so what I would +say is if you're struggling with that in + + align:start position:0% +say is if you're struggling with that in + + + align:start position:0% +say is if you're struggling with that in +your script um literally read your words + + align:start position:0% +your script um literally read your words + + + align:start position:0% +your script um literally read your words +aloud and then put your script away so + + align:start position:0% +aloud and then put your script away so + + + align:start position:0% +aloud and then put your script away so +that you can't see it and just explain + + align:start position:0% +that you can't see it and just explain + + + align:start position:0% +that you can't see it and just explain +your sentence sort of um ad libed to + + align:start position:0% +your sentence sort of um ad libed to + + + align:start position:0% +your sentence sort of um ad libed to +someone next to you um so this happened + + align:start position:0% +someone next to you um so this happened + + + align:start position:0% +someone next to you um so this happened +a lot to me I actually went through all + + align:start position:0% +a lot to me I actually went through all + + + align:start position:0% +a lot to me I actually went through all +the exercises that you guys are going to + + align:start position:0% +the exercises that you guys are going to + + + align:start position:0% +the exercises that you guys are going to +do this month myself to sort of see if + + align:start position:0% +do this month myself to sort of see if + + + align:start position:0% +do this month myself to sort of see if +what I was saying made sense um and + + align:start position:0% +what I was saying made sense um and + + + align:start position:0% +what I was saying made sense um and +George and I created an episode about + + align:start position:0% +George and I created an episode about + + + align:start position:0% +George and I created an episode about +snot and the writing process process was + + align:start position:0% +snot and the writing process process was + + + align:start position:0% +snot and the writing process process was +a lot harder for me than I thought it + + align:start position:0% +a lot harder for me than I thought it + + + align:start position:0% +a lot harder for me than I thought it +would be even though I've coached so + + align:start position:0% +would be even though I've coached so + + + align:start position:0% +would be even though I've coached so +many people through it and it was + + align:start position:0% +many people through it and it was + + + align:start position:0% +many people through it and it was +because I fell into this habit of being + + align:start position:0% +because I fell into this habit of being + + + align:start position:0% +because I fell into this habit of being +super newscaster and that's my personal + + align:start position:0% +super newscaster and that's my personal + + + align:start position:0% +super newscaster and that's my personal +habit that I I'll say things like you + + align:start position:0% +habit that I I'll say things like you + + + align:start position:0% +habit that I I'll say things like you +think this would do this but turns out + + align:start position:0% +think this would do this but turns out + + + align:start position:0% +think this would do this but turns out +it doesn't right um and I would say this + + align:start position:0% +it doesn't right um and I would say this + + + align:start position:0% +it doesn't right um and I would say this +sounds awful and George would take my + + align:start position:0% +sounds awful and George would take my + + + align:start position:0% +sounds awful and George would take my +script away and he would say Elizabeth + + align:start position:0% +script away and he would say Elizabeth + + + align:start position:0% +script away and he would say Elizabeth +what are you what is so cool about snot + + align:start position:0% +what are you what is so cool about snot + + + align:start position:0% +what are you what is so cool about snot +and I'd say well it's awesome because + + align:start position:0% +and I'd say well it's awesome because + + + align:start position:0% +and I'd say well it's awesome because +you think that it's just like this crap + + align:start position:0% +you think that it's just like this crap + + + align:start position:0% +you think that it's just like this crap +that flows out of your body but turns + + align:start position:0% +that flows out of your body but turns + + + align:start position:0% +that flows out of your body but turns +out that it has like all these really + + align:start position:0% +out that it has like all these really + + + align:start position:0% +out that it has like all these really +amazing things about it and you even say + + align:start position:0% +amazing things about it and you even say + + + align:start position:0% +amazing things about it and you even say +well you should just say that um so as + + align:start position:0% +well you should just say that um so as + + + align:start position:0% +well you should just say that um so as +you script or as you try to think of + + align:start position:0% +you script or as you try to think of + + + align:start position:0% +you script or as you try to think of +ideas um turn to your partner and just + + align:start position:0% +ideas um turn to your partner and just + + + align:start position:0% +ideas um turn to your partner and just +tell them as you would tell anyone what + + align:start position:0% +tell them as you would tell anyone what + + + align:start position:0% +tell them as you would tell anyone what +what it is you're trying to convey what + + align:start position:0% +what it is you're trying to convey what + + + align:start position:0% +what it is you're trying to convey what +it is you're excited about um Jamie did + + align:start position:0% +it is you're excited about um Jamie did + + + align:start position:0% +it is you're excited about um Jamie did +you want to add anything to that well I + + align:start position:0% +you want to add anything to that well I + + + align:start position:0% +you want to add anything to that well I +think I think right now we've got about + + align:start position:0% +think I think right now we've got about + + + align:start position:0% +think I think right now we've got about +35 minutes before the end of class and I + + align:start position:0% +35 minutes before the end of class and I + + + align:start position:0% +35 minutes before the end of class and I +suspect we have some wrapup that we need + + align:start position:0% +suspect we have some wrapup that we need + + + align:start position:0% +suspect we have some wrapup that we need +to do to talk about what to do tonight + + align:start position:0% +to do to talk about what to do tonight + + + align:start position:0% +to do to talk about what to do tonight +and what to do to get ready for tomorrow + + align:start position:0% +and what to do to get ready for tomorrow + + + align:start position:0% +and what to do to get ready for tomorrow +so that really puts us more at 20 25 + + align:start position:0% +so that really puts us more at 20 25 + + + align:start position:0% +so that really puts us more at 20 25 +minutes right I feel like maybe what we + + align:start position:0% +minutes right I feel like maybe what we + + + align:start position:0% +minutes right I feel like maybe what we +need to do is old school actually have + + align:start position:0% +need to do is old school actually have + + + align:start position:0% +need to do is old school actually have +each of one of you think with paper and + + align:start position:0% +each of one of you think with paper and + + + align:start position:0% +each of one of you think with paper and +pen and brainstorm a little and then + + align:start position:0% +pen and brainstorm a little and then + + + align:start position:0% +pen and brainstorm a little and then +come back together as a group a little + + align:start position:0% +come back together as a group a little + + + align:start position:0% +come back together as a group a little +bit so that you have some time to really + + align:start position:0% +bit so that you have some time to really + + + align:start position:0% +bit so that you have some time to really +conceptualize like like if I were to do + + align:start position:0% +conceptualize like like if I were to do + + + align:start position:0% +conceptualize like like if I were to do +this on my own I'm just saying like I + + align:start position:0% +this on my own I'm just saying like I + + + align:start position:0% +this on my own I'm just saying like I +would actually do an old school + + align:start position:0% +would actually do an old school + + + align:start position:0% +would actually do an old school +spiderweb to get my ideas out which is + + align:start position:0% +spiderweb to get my ideas out which is + + + align:start position:0% +spiderweb to get my ideas out which is +put this guy down here I would actually + + align:start position:0% +put this guy down here I would actually + + + align:start position:0% +put this guy down here I would actually +probably put my my topic in the middle + + align:start position:0% +probably put my my topic in the middle + + + align:start position:0% +probably put my my topic in the middle +and start brainstorming everything that + + align:start position:0% +and start brainstorming everything that + + + align:start position:0% +and start brainstorming everything that +I can about it to just keep me thinking + + align:start position:0% +I can about it to just keep me thinking + + + align:start position:0% +I can about it to just keep me thinking +about what like and then to maybe + + align:start position:0% +about what like and then to maybe + + + align:start position:0% +about what like and then to maybe +realize if ship building is in the + + align:start position:0% +realize if ship building is in the + + + align:start position:0% +realize if ship building is in the +middle here and we talked about ships + + align:start position:0% +middle here and we talked about ships + + + align:start position:0% +middle here and we talked about ships +like what specifically within ships am I + + align:start position:0% +like what specifically within ships am I + + + align:start position:0% +like what specifically within ships am I +thinking about did we want to talk about + + align:start position:0% +thinking about did we want to talk about + + + align:start position:0% +thinking about did we want to talk about +seasickness all right then if I wanted + + align:start position:0% +seasickness all right then if I wanted + + + align:start position:0% +seasickness all right then if I wanted +to talk about seasickness what would I + + align:start position:0% +to talk about seasickness what would I + + + align:start position:0% +to talk about seasickness what would I +put in my video right and to really + + align:start position:0% +put in my video right and to really + + + align:start position:0% +put in my video right and to really +visualize for yourself all the topics + + align:start position:0% +visualize for yourself all the topics + + + align:start position:0% +visualize for yourself all the topics +Concepts things you would want to film + + align:start position:0% +Concepts things you would want to film + + + align:start position:0% +Concepts things you would want to film +and start getting a sense for yourself + + align:start position:0% +and start getting a sense for yourself + + + align:start position:0% +and start getting a sense for yourself +of whether or not this is a doable + + align:start position:0% +of whether or not this is a doable + + + align:start position:0% +of whether or not this is a doable +concept and you may realize that + + align:start position:0% +concept and you may realize that + + + align:start position:0% +concept and you may realize that +actually this is the branch I want to + + align:start position:0% +actually this is the branch I want to + + + align:start position:0% +actually this is the branch I want to +keep exploring as opposed to this whole + + align:start position:0% +keep exploring as opposed to this whole + + + align:start position:0% +keep exploring as opposed to this whole +big thing and If This Were My Brain + + align:start position:0% +big thing and If This Were My Brain + + + align:start position:0% +big thing and If This Were My Brain +that's how this would work but if + + align:start position:0% +that's how this would work but if + + + align:start position:0% +that's how this would work but if +there's a different way that your brain + + align:start position:0% +there's a different way that your brain + + + align:start position:0% +there's a different way that your brain +works we want you I would think that you + + align:start position:0% +works we want you I would think that you + + + align:start position:0% +works we want you I would think that you +should use this time a little bit solo + + align:start position:0% +should use this time a little bit solo + + + align:start position:0% +should use this time a little bit solo +and then we'll have a chance to maybe + + align:start position:0% +and then we'll have a chance to maybe + + + align:start position:0% +and then we'll have a chance to maybe +bounce some ideas off so I feel like + + align:start position:0% +bounce some ideas off so I feel like + + + align:start position:0% +bounce some ideas off so I feel like +people at least what I heard from people + + align:start position:0% +people at least what I heard from people + + + align:start position:0% +people at least what I heard from people +was that this morning was really helpful + + align:start position:0% +was that this morning was really helpful + + + align:start position:0% +was that this morning was really helpful +but it made you realize you really need + + align:start position:0% +but it made you realize you really need + + + align:start position:0% +but it made you realize you really need +to narrow your topic and really think it + + align:start position:0% +to narrow your topic and really think it + + + align:start position:0% +to narrow your topic and really think it +through a little bit so maybe what we do + + align:start position:0% +through a little bit so maybe what we do + + + align:start position:0% +through a little bit so maybe what we do +is we spend about 10 minutes quietly + + align:start position:0% +is we spend about 10 minutes quietly + + + align:start position:0% +is we spend about 10 minutes quietly +working on our own to really flesh out + + align:start position:0% +working on our own to really flesh out + + + align:start position:0% +working on our own to really flesh out +our Concepts and then we get back + + align:start position:0% +our Concepts and then we get back + + + align:start position:0% +our Concepts and then we get back +together as a group um do you need paper + + align:start position:0% +together as a group um do you need paper + + + align:start position:0% +together as a group um do you need paper +I have paper does anyone need you need + + align:start position:0% +I have paper does anyone need you need + + + align:start position:0% +I have paper does anyone need you need +some paper and pens I'll go grab them in + + align:start position:0% +some paper and pens I'll go grab them in + + + align:start position:0% +some paper and pens I'll go grab them in +my office um I'll get some real quick I + + align:start position:0% +my office um I'll get some real quick I + + + align:start position:0% +my office um I'll get some real quick I +mean there are so many strategies um and + + align:start position:0% +mean there are so many strategies um and + + + align:start position:0% +mean there are so many strategies um and +people have different preferences of + + align:start position:0% +people have different preferences of + + + align:start position:0% +people have different preferences of +beginning to script I wasn't going to + + align:start position:0% +beginning to script I wasn't going to + + + align:start position:0% +beginning to script I wasn't going to +share this until tonight but maybe it + + align:start position:0% +share this until tonight but maybe it + + + align:start position:0% +share this until tonight but maybe it +would help to do it right now um so when + + align:start position:0% +would help to do it right now um so when + + + align:start position:0% +would help to do it right now um so when +I was sitting down to script the snot + + align:start position:0% +I was sitting down to script the snot + + + align:start position:0% +I was sitting down to script the snot +episode and again I'm not saying that + + align:start position:0% +episode and again I'm not saying that + + + align:start position:0% +episode and again I'm not saying that +this is the best way to do it nor am I + + align:start position:0% +this is the best way to do it nor am I + + + align:start position:0% +this is the best way to do it nor am I +saying it's the right way to do it um + + align:start position:0% +saying it's the right way to do it um + + + align:start position:0% +saying it's the right way to do it um +but I was fixated on the idea that your + + align:start position:0% +but I was fixated on the idea that your + + + align:start position:0% +but I was fixated on the idea that your +body makes a gallon of snot a day that + + align:start position:0% +body makes a gallon of snot a day that + + + align:start position:0% +body makes a gallon of snot a day that +was really the seed that began the idea + + align:start position:0% +was really the seed that began the idea + + + align:start position:0% +was really the seed that began the idea +of the episode um so George Who you'll + + align:start position:0% +of the episode um so George Who you'll + + + align:start position:0% +of the episode um so George Who you'll +meet tomorrow said well just list every + + align:start position:0% +meet tomorrow said well just list every + + + align:start position:0% +meet tomorrow said well just list every +amazing thing about snot that you want + + align:start position:0% +amazing thing about snot that you want + + + align:start position:0% +amazing thing about snot that you want +to talk about so I didn't even start + + align:start position:0% +to talk about so I didn't even start + + + align:start position:0% +to talk about so I didn't even start +with an idea of a story or anything all + + align:start position:0% +with an idea of a story or anything all + + + align:start position:0% +with an idea of a story or anything all +I did was list + + align:start position:0% +I did was list + + + align:start position:0% +I did was list +every um every sort of fact about mucus + + align:start position:0% +every um every sort of fact about mucus + + + align:start position:0% +every um every sort of fact about mucus +that I was interested in and this is + + align:start position:0% +that I was interested in and this is + + + align:start position:0% +that I was interested in and this is +sort of the same concept of having a web + + align:start position:0% +sort of the same concept of having a web + + + align:start position:0% +sort of the same concept of having a web +I just put it in a list but it doesn't + + align:start position:0% +I just put it in a list but it doesn't + + + align:start position:0% +I just put it in a list but it doesn't +really matter + + align:start position:0% +really matter + + + align:start position:0% +really matter +um and as I was going through um and + + align:start position:0% +um and as I was going through um and + + + align:start position:0% +um and as I was going through um and +some of this was stuff that I had + + align:start position:0% +some of this was stuff that I had + + + align:start position:0% +some of this was stuff that I had +learned in a class I took as an + + align:start position:0% +learned in a class I took as an + + + align:start position:0% +learned in a class I took as an +undergrad so I was looking through my + + align:start position:0% +undergrad so I was looking through my + + + align:start position:0% +undergrad so I was looking through my +old notes basically um there was a lot + + align:start position:0% +old notes basically um there was a lot + + + align:start position:0% +old notes basically um there was a lot +of stuff in here and I ended up taking + + align:start position:0% +of stuff in here and I ended up taking + + + align:start position:0% +of stuff in here and I ended up taking +out maybe two-thirds of it for the final + + align:start position:0% +out maybe two-thirds of it for the final + + + align:start position:0% +out maybe two-thirds of it for the final +script but this is what got me started + + align:start position:0% +script but this is what got me started + + + align:start position:0% +script but this is what got me started +you know um mucus is a problem mucus as + + align:start position:0% +you know um mucus is a problem mucus as + + + align:start position:0% +you know um mucus is a problem mucus as +a solution to things just like random + + align:start position:0% +a solution to things just like random + + + align:start position:0% +a solution to things just like random +cool facts about mucus uh the research + + align:start position:0% +cool facts about mucus uh the research + + + align:start position:0% +cool facts about mucus uh the research +that's + + align:start position:0% +that's + + + align:start position:0% +that's +happening and at just the process of + + align:start position:0% +happening and at just the process of + + + align:start position:0% +happening and at just the process of +going through all of these things helped + + align:start position:0% +going through all of these things helped + + + align:start position:0% +going through all of these things helped +me discover a story and it just the + + align:start position:0% +me discover a story and it just the + + + align:start position:0% +me discover a story and it just the +process itself did so if you would find + + align:start position:0% +process itself did so if you would find + + + align:start position:0% +process itself did so if you would find +it helpful to do sort of a brain dump + + align:start position:0% +it helpful to do sort of a brain dump + + + align:start position:0% +it helpful to do sort of a brain dump +idea in the next 10 minutes feel free to + + align:start position:0% +idea in the next 10 minutes feel free to + + + align:start position:0% +idea in the next 10 minutes feel free to +do that again we're not saying that you + + align:start position:0% +do that again we're not saying that you + + + align:start position:0% +do that again we're not saying that you +have to do any any of these methods but + + align:start position:0% +have to do any any of these methods but + + + align:start position:0% +have to do any any of these methods but +this is what's helped me personally um + + align:start position:0% +this is what's helped me personally um + + + align:start position:0% +this is what's helped me personally um +in the practice of doing this so feel + + align:start position:0% +in the practice of doing this so feel + + + align:start position:0% +in the practice of doing this so feel +free to do something like this um I had + + align:start position:0% +free to do something like this um I had + + + align:start position:0% +free to do something like this um I had +some ideas of like demos I could do um + + align:start position:0% +some ideas of like demos I could do um + + + align:start position:0% +some ideas of like demos I could do um +Ted Ed when they recruit people to write + + align:start position:0% +Ted Ed when they recruit people to write + + + align:start position:0% +Ted Ed when they recruit people to write +scripts they have a requirement that you + + align:start position:0% +scripts they have a requirement that you + + + align:start position:0% +scripts they have a requirement that you +have a sharable fact in your video so + + align:start position:0% +have a sharable fact in your video so + + + align:start position:0% +have a sharable fact in your video so +what's the fact in the video that's + + align:start position:0% +what's the fact in the video that's + + + align:start position:0% +what's the fact in the video that's +going to go viral so I was brainstorming + + align:start position:0% +going to go viral so I was brainstorming + + + align:start position:0% +going to go viral so I was brainstorming +what could be some sharable facts in the + + align:start position:0% +what could be some sharable facts in the + + + align:start position:0% +what could be some sharable facts in the +script uh and + + align:start position:0% +script uh and + + + align:start position:0% +script uh and +then uh I was thinking about what's the + + align:start position:0% +then uh I was thinking about what's the + + + align:start position:0% +then uh I was thinking about what's the +point ycas is alive that actually ended + + align:start position:0% +point ycas is alive that actually ended + + + align:start position:0% +point ycas is alive that actually ended +up not making the final video at all but + + align:start position:0% +up not making the final video at all but + + + align:start position:0% +up not making the final video at all but +the exercise and the just the act of + + align:start position:0% +the exercise and the just the act of + + + align:start position:0% +the exercise and the just the act of +doing that helped me figure out what the + + align:start position:0% +doing that helped me figure out what the + + + align:start position:0% +doing that helped me figure out what the +point of the video was going to + + align:start position:0% +point of the video was going to + + + align:start position:0% +point of the video was going to +be so let's let's maybe spend like 5 to + + align:start position:0% +be so let's let's maybe spend like 5 to + + + align:start position:0% +be so let's let's maybe spend like 5 to +10 minutes of just quiet time for you to + + align:start position:0% +10 minutes of just quiet time for you to + + + align:start position:0% +10 minutes of just quiet time for you to +really think about your topic and then + + align:start position:0% +really think about your topic and then + + + align:start position:0% +really think about your topic and then +and then maybe we can like slowly check + + align:start position:0% +and then maybe we can like slowly check + + + align:start position:0% +and then maybe we can like slowly check +in with people and then maybe come back + + align:start position:0% +in with people and then maybe come back + + + align:start position:0% +in with people and then maybe come back +together and see if people are + + align:start position:0% +together and see if people are + + + align:start position:0% +together and see if people are +struggling with + + align:start position:0% + + + + align:start position:0% + +anything I see from your head nods that + + align:start position:0% +anything I see from your head nods that + + + align:start position:0% +anything I see from your head nods that +sounds like a good plan yes + + align:start position:0% + + + + align:start position:0% + +okay for + + align:start position:0% + + + + align:start position:0% + +that's + + align:start position:0% + + + + align:start position:0% + +we for + + align:start position:0% + + + + align:start position:0% + +yeah yeah we + + align:start position:0% +yeah yeah we + + + align:start position:0% +yeah yeah we +can yeah I think we're finished with the + + align:start position:0% +can yeah I think we're finished with the + + + align:start position:0% +can yeah I think we're finished with the +presentation + + align:start position:0% + + + + align:start position:0% + +do you know how um omnivores what is it + + align:start position:0% +do you know how um omnivores what is it + + + align:start position:0% +do you know how um omnivores what is it +not omnivores what's it called opportun + + align:start position:0% + + + + align:start position:0% + +ofor no they're people who eat like + + align:start position:0% +ofor no they're people who eat like + + + align:start position:0% +ofor no they're people who eat like +rotting food it's like a it's like so um + + align:start position:0% +rotting food it's like a it's like so um + + + align:start position:0% +rotting food it's like a it's like so um +I have this great story I'll have to + + align:start position:0% +I have this great story I'll have to + + + align:start position:0% +I have this great story I'll have to +give you if this is what you decide to + + align:start position:0% +give you if this is what you decide to + + + align:start position:0% +give you if this is what you decide to +do um a a non-fiction piece that was + + align:start position:0% +do um a a non-fiction piece that was + + + align:start position:0% +do um a a non-fiction piece that was +written by journalist exploring people + + align:start position:0% +written by journalist exploring people + + + align:start position:0% +written by journalist exploring people +who actually live off of people's + + align:start position:0% +who actually live off of people's + + + align:start position:0% +who actually live off of people's +decomposing food scraps oh so like fans + + align:start position:0% +decomposing food scraps oh so like fans + + + align:start position:0% +decomposing food scraps oh so like fans +I guess is that another word for it + + align:start position:0% +I guess is that another word for it + + + align:start position:0% +I guess is that another word for it +like I know actually do know some people + + align:start position:0% +like I know actually do know some people + + + align:start position:0% +like I know actually do know some people +who their diet is basically composed to + + align:start position:0% +who their diet is basically composed to + + + align:start position:0% +who their diet is basically composed to +free food and like what is fermenting + + align:start position:0% +free food and like what is fermenting + + + align:start position:0% +free food and like what is fermenting +fermenting is like beer and cheese and + + align:start position:0% +fermenting is like beer and cheese and + + + align:start position:0% +fermenting is like beer and cheese and +like fermenting is a whole other Concept + + align:start position:0% +like fermenting is a whole other Concept + + + align:start position:0% +like fermenting is a whole other Concept +in here + + align:start position:0% +in here + + + align:start position:0% +in here +right which is actually a really cool + + align:start position:0% +right which is actually a really cool + + + align:start position:0% +right which is actually a really cool +concept I don't know I I kind of was + + align:start position:0% +concept I don't know I I kind of was + + + align:start position:0% +concept I don't know I I kind of was +like I looked there's a lot of things + + align:start position:0% +like I looked there's a lot of things + + + align:start position:0% +like I looked there's a lot of things +things like beer and cheese and I was + + align:start position:0% +things like beer and cheese and I was + + + align:start position:0% +things like beer and cheese and I was +like what isn't there anything up that + + align:start position:0% +like what isn't there anything up that + + + align:start position:0% +like what isn't there anything up that +I'm interested in I guess the conflict I + + align:start position:0% +I'm interested in I guess the conflict I + + + align:start position:0% +I'm interested in I guess the conflict I +have right now is that seeing people + + align:start position:0% +have right now is that seeing people + + + align:start position:0% +have right now is that seeing people +were into in volcanoes and that's easier + + align:start position:0% +were into in volcanoes and that's easier + + + align:start position:0% +were into in volcanoes and that's easier +cuz I actually + + align:start position:0% +cuz I actually + + + align:start position:0% +cuz I actually +I know a lot about this this would be + + align:start position:0% +I know a lot about this this would be + + + align:start position:0% +I know a lot about this this would be +something I'd have to learn about a lot + + align:start position:0% +something I'd have to learn about a lot + + + align:start position:0% +something I'd have to learn about a lot +okay but that's kind of what I want to + + align:start position:0% +okay but that's kind of what I want to + + + align:start position:0% +okay but that's kind of what I want to +do more okay is I want to learn a topic + + align:start position:0% +do more okay is I want to learn a topic + + + align:start position:0% +do more okay is I want to learn a topic +as opposed to just going in with what I + + align:start position:0% +as opposed to just going in with what I + + + align:start position:0% +as opposed to just going in with what I +know what what makes you so excited + + align:start position:0% +know what what makes you so excited + + + align:start position:0% +know what what makes you so excited +about this topic um I don't know + + align:start position:0% +about this topic um I don't know + + + align:start position:0% +about this topic um I don't know +anything about it + + align:start position:0% +anything about it + + + align:start position:0% +anything about it +and um I think about something that + + align:start position:0% +and um I think about something that + + + align:start position:0% +and um I think about something that +happens a lot um whether it's because my + + align:start position:0% +happens a lot um whether it's because my + + + align:start position:0% +happens a lot um whether it's because my +DM Halls terrible that maintaining our + + align:start position:0% +DM Halls terrible that maintaining our + + + align:start position:0% +DM Halls terrible that maintaining our +fridge and so there's always things in + + align:start position:0% +fridge and so there's always things in + + + align:start position:0% +fridge and so there's always things in +it it's rotting that's rotting and I'm + + align:start position:0% +it it's rotting that's rotting and I'm + + + align:start position:0% +it it's rotting that's rotting and I'm +looking at it's like wow this is neat + + align:start position:0% +looking at it's like wow this is neat + + + align:start position:0% +looking at it's like wow this is neat +how did this beautiful broccoli turn + + align:start position:0% +how did this beautiful broccoli turn + + + align:start position:0% +how did this beautiful broccoli turn +into this black + + align:start position:0% +into this black + + + align:start position:0% +into this black +muck and um different things like that + + align:start position:0% +muck and um different things like that + + + align:start position:0% +muck and um different things like that +that's sex there fascinates me a lot + + align:start position:0% +that's sex there fascinates me a lot + + + align:start position:0% +that's sex there fascinates me a lot +like the + + align:start position:0% +like the + + + align:start position:0% +like the +transformation um and why why do things + + align:start position:0% +transformation um and why why do things + + + align:start position:0% +transformation um and why why do things +and like different things why things + + align:start position:0% +and like different things why things + + + align:start position:0% +and like different things why things +some things decompose in different ways + + align:start position:0% +some things decompose in different ways + + + align:start position:0% +some things decompose in different ways +like where you know like if if meat + + align:start position:0% +like where you know like if if meat + + + align:start position:0% +like where you know like if if meat +starts to rot then even if you cook it + + align:start position:0% +starts to rot then even if you cook it + + + align:start position:0% +starts to rot then even if you cook it +it's not going to that's not good you + + align:start position:0% +it's not going to that's not good you + + + align:start position:0% +it's not going to that's not good you +just can't eat it but some things you + + align:start position:0% +just can't eat it but some things you + + + align:start position:0% +just can't eat it but some things you +can kind of like like say well you know + + align:start position:0% +can kind of like like say well you know + + + align:start position:0% +can kind of like like say well you know +you you can if you cook it well enough + + align:start position:0% +you you can if you cook it well enough + + + align:start position:0% +you you can if you cook it well enough +it'll be fine um and also like the whole + + align:start position:0% +it'll be fine um and also like the whole + + + align:start position:0% +it'll be fine um and also like the whole +concept of how you prevent this you know + + align:start position:0% +concept of how you prevent this you know + + + align:start position:0% +concept of how you prevent this you know +like yeah looking at it and there's like + + align:start position:0% +like yeah looking at it and there's like + + + align:start position:0% +like yeah looking at it and there's like +all these different ways that you can + + align:start position:0% +all these different ways that you can + + + align:start position:0% +all these different ways that you can +you know prevent you know this like they + + align:start position:0% +you know prevent you know this like they + + + align:start position:0% +you know prevent you know this like they +have the three tactics of like killing + + align:start position:0% +have the three tactics of like killing + + + align:start position:0% +have the three tactics of like killing +things that are like bacteria and fungi + + align:start position:0% +things that are like bacteria and fungi + + + align:start position:0% +things that are like bacteria and fungi +that CA it and there like attacking like + + align:start position:0% +that CA it and there like attacking like + + + align:start position:0% +that CA it and there like attacking like +preventing like their functions that + + align:start position:0% +preventing like their functions that + + + align:start position:0% +preventing like their functions that +they do like the enzymes and then those + + align:start position:0% +they do like the enzymes and then those + + + align:start position:0% +they do like the enzymes and then those +um more like controlling their clothes + + align:start position:0% +um more like controlling their clothes + + + align:start position:0% +um more like controlling their clothes +so maybe maybe I mean I love the story + + align:start position:0% +so maybe maybe I mean I love the story + + + align:start position:0% +so maybe maybe I mean I love the story +that you picked um PS remind me sometime + + align:start position:0% +that you picked um PS remind me sometime + + + align:start position:0% +that you picked um PS remind me sometime +to tell you about the story I wrote for + + align:start position:0% +to tell you about the story I wrote for + + + align:start position:0% +to tell you about the story I wrote for +Backpacker magazine where I took a whole + + align:start position:0% +Backpacker magazine where I took a whole + + + align:start position:0% +Backpacker magazine where I took a whole +backpack's worth of food and saw what + + align:start position:0% +backpack's worth of food and saw what + + + align:start position:0% +backpack's worth of food and saw what +rotted over the course of a week to see + + align:start position:0% +rotted over the course of a week to see + + + align:start position:0% +rotted over the course of a week to see +what the best foods are to take hiking + + align:start position:0% +what the best foods are to take hiking + + + align:start position:0% +what the best foods are to take hiking +so I did I did a piece on this um in my + + align:start position:0% +so I did I did a piece on this um in my + + + align:start position:0% +so I did I did a piece on this um in my +earlier days and it was really fun but + + align:start position:0% +earlier days and it was really fun but + + + align:start position:0% +earlier days and it was really fun but +um I actually found that there were + + align:start position:0% +um I actually found that there were + + + align:start position:0% +um I actually found that there were +maggots that showed up in the completely + + align:start position:0% +maggots that showed up in the completely + + + align:start position:0% +maggots that showed up in the completely +sealed um baloney and it grossed me + + align:start position:0% +sealed um baloney and it grossed me + + + align:start position:0% +sealed um baloney and it grossed me +entirely cuz you're like they must have + + align:start position:0% +entirely cuz you're like they must have + + + align:start position:0% +entirely cuz you're like they must have +been there from the start is + + align:start position:0% +been there from the start is + + + align:start position:0% +been there from the start is +terrifying yeah the things that like + + align:start position:0% +terrifying yeah the things that like + + + align:start position:0% +terrifying yeah the things that like +start and they would meet like things + + align:start position:0% +start and they would meet like things + + + align:start position:0% +start and they would meet like things +that the animal has right go through the + + align:start position:0% +that the animal has right go through the + + + align:start position:0% +that the animal has right go through the +entire process and they survive but the + + align:start position:0% +entire process and they survive but the + + + align:start position:0% +entire process and they survive but the +story that I love that you just told me + + align:start position:0% +story that I love that you just told me + + + align:start position:0% +story that I love that you just told me +about was you going into your dorm and + + align:start position:0% +about was you going into your dorm and + + + align:start position:0% +about was you going into your dorm and +seeing that broccoli and being like why + + align:start position:0% +seeing that broccoli and being like why + + + align:start position:0% +seeing that broccoli and being like why +did this happen and why does it smell so + + align:start position:0% +did this happen and why does it smell so + + + align:start position:0% +did this happen and why does it smell so +bad and you could make your whole five + + align:start position:0% +bad and you could make your whole five + + + align:start position:0% +bad and you could make your whole five +minute piece about that do you know what + + align:start position:0% +minute piece about that do you know what + + + align:start position:0% +minute piece about that do you know what +I mean like just that little anecdote of + + align:start position:0% +I mean like just that little anecdote of + + + align:start position:0% +I mean like just that little anecdote of +you looking in your fridge and seeing + + align:start position:0% +you looking in your fridge and seeing + + + align:start position:0% +you looking in your fridge and seeing +this nasty broccoli and being like why + + align:start position:0% +this nasty broccoli and being like why + + + align:start position:0% +this nasty broccoli and being like why +does this happen that's your story you + + align:start position:0% +does this happen that's your story you + + + align:start position:0% +does this happen that's your story you +know and I thought and then all this + + align:start position:0% +know and I thought and then all this + + + align:start position:0% +know and I thought and then all this +comes from that it's just like a very + + align:start position:0% +comes from that it's just like a very + + + align:start position:0% +comes from that it's just like a very +big topic cuz I made my video and I + + align:start position:0% +big topic cuz I made my video and I + + + align:start position:0% +big topic cuz I made my video and I +looked in it and I don't really go that + + align:start position:0% +looked in it and I don't really go that + + + align:start position:0% +looked in it and I don't really go that +far into anything mhm and it's 5 minutes + + align:start position:0% +far into anything mhm and it's 5 minutes + + + align:start position:0% +far into anything mhm and it's 5 minutes +already you know and I but if you were + + align:start position:0% +already you know and I but if you were + + + align:start position:0% +already you know and I but if you were +to really narrowly look at what's going + + align:start position:0% +to really narrowly look at what's going + + + align:start position:0% +to really narrowly look at what's going +on with that broccoli yeah that's + + align:start position:0% +on with that broccoli yeah that's + + + align:start position:0% +on with that broccoli yeah that's +actually really great five minute piece + + align:start position:0% +actually really great five minute piece + + + align:start position:0% +actually really great five minute piece +cuz like I mean I looked and on YouTube + + align:start position:0% +cuz like I mean I looked and on YouTube + + + align:start position:0% +cuz like I mean I looked and on YouTube +they have this time lapse of things + + align:start position:0% +they have this time lapse of things + + + align:start position:0% +they have this time lapse of things +decaying but there's nothing ever + + align:start position:0% +decaying but there's nothing ever + + + align:start position:0% +decaying but there's nothing ever +explains why or how or what does it + + align:start position:0% +explains why or how or what does it + + + align:start position:0% +explains why or how or what does it +right like basically the only thing that + + align:start position:0% +right like basically the only thing that + + + align:start position:0% +right like basically the only thing that +there is on the internet in like video + + align:start position:0% +there is on the internet in like video + + + align:start position:0% +there is on the internet in like video +form is watching things do it but + + align:start position:0% +form is watching things do it but + + + align:start position:0% +form is watching things do it but +there's no explanation of like why does + + align:start position:0% +there's no explanation of like why does + + + align:start position:0% +there's no explanation of like why does +it become so darn smelly's a buch you + + align:start position:0% +it become so darn smelly's a buch you + + + align:start position:0% +it become so darn smelly's a buch you +know I can go and read academic papers + + align:start position:0% +know I can go and read academic papers + + + align:start position:0% +know I can go and read academic papers +but + + align:start position:0% +but + + + align:start position:0% +but +acemic but like also the question I mean + + align:start position:0% +acemic but like also the question I mean + + + align:start position:0% +acemic but like also the question I mean +if you think about this if your if your + + align:start position:0% +if you think about this if your if your + + + align:start position:0% +if you think about this if your if your +Center becomes instead of food + + align:start position:0% +Center becomes instead of food + + + align:start position:0% +Center becomes instead of food +decomposition but broccoli the broccoli + + align:start position:0% +decomposition but broccoli the broccoli + + + align:start position:0% +decomposition but broccoli the broccoli +right looking at that broccoli so many + + align:start position:0% +right looking at that broccoli so many + + + align:start position:0% +right looking at that broccoli so many +questions come out of that like when is + + align:start position:0% +questions come out of that like when is + + + align:start position:0% +questions come out of that like when is +it not okay to eat it like it looks + + align:start position:0% +it not okay to eat it like it looks + + + align:start position:0% +it not okay to eat it like it looks +nasty but is it still safe to eat it and + + align:start position:0% +nasty but is it still safe to eat it and + + + align:start position:0% +nasty but is it still safe to eat it and +like what's happening in there and what + + align:start position:0% +like what's happening in there and what + + + align:start position:0% +like what's happening in there and what +how long can I expect my broccoli to + + align:start position:0% +how long can I expect my broccoli to + + + align:start position:0% +how long can I expect my broccoli to +last there's this cool people that you + + align:start position:0% +last there's this cool people that you + + + align:start position:0% +last there's this cool people that you +might end up wanting to talk + + align:start position:0% +might end up wanting to talk + + + align:start position:0% +might end up wanting to talk +to that I went to an innovation + + align:start position:0% +to that I went to an innovation + + + align:start position:0% +to that I went to an innovation +conference last year at the I'll have to + + align:start position:0% +conference last year at the I'll have to + + + align:start position:0% +conference last year at the I'll have to +look up the name these people made this + + align:start position:0% +look up the name these people made this + + + align:start position:0% +look up the name these people made this +device to be able to tell you when your + + align:start position:0% +device to be able to tell you when your + + + align:start position:0% +device to be able to tell you when your +food is rotting in your fridge and it's + + align:start position:0% +food is rotting in your fridge and it's + + + align:start position:0% +food is rotting in your fridge and it's +an innovation that's happening on campus + + align:start position:0% +an innovation that's happening on campus + + + align:start position:0% +an innovation that's happening on campus +that you could actually go talk to those + + align:start position:0% +that you could actually go talk to those + + + align:start position:0% +that you could actually go talk to those +people that they've actually really + + align:start position:0% +people that they've actually really + + + align:start position:0% +people that they've actually really +really thought deeply about food waste + + align:start position:0% +really thought deeply about food waste + + + align:start position:0% +really thought deeply about food waste +and created a device that would attach + + align:start position:0% +and created a device that would attach + + + align:start position:0% +and created a device that would attach +to your fridge to tell you like bananas + + align:start position:0% +to your fridge to tell you like bananas + + + align:start position:0% +to your fridge to tell you like bananas +are going bad in 3 days you know and + + align:start position:0% +are going bad in 3 days you know and + + + align:start position:0% +are going bad in 3 days you know and +there people on campus so I have to + + align:start position:0% +there people on campus so I have to + + + align:start position:0% +there people on campus so I have to +think about their name but there's this + + align:start position:0% +think about their name but there's this + + + align:start position:0% +think about their name but there's this +really cool lab that's actually really + + align:start position:0% +really cool lab that's actually really + + + align:start position:0% +really cool lab that's actually really +exploring this topic that you could talk + + align:start position:0% +exploring this topic that you could talk + + + align:start position:0% +exploring this topic that you could talk +to yeah and then I actually just had a + + align:start position:0% +to yeah and then I actually just had a + + + align:start position:0% +to yeah and then I actually just had a +random idea that was completely under + + align:start position:0% +random idea that was completely under + + + align:start position:0% +random idea that was completely under +everything I had before which is the + + align:start position:0% +everything I had before which is the + + + align:start position:0% +everything I had before which is the +concept of a world without decomposition + + align:start position:0% +concept of a world without decomposition + + + align:start position:0% +concept of a world without decomposition +with that why did things die or sort of + + align:start position:0% +with that why did things die or sort of + + + align:start position:0% +with that why did things die or sort of +a world in which things did not de + + align:start position:0% +a world in which things did not de + + + align:start position:0% +a world in which things did not de +compose what would that look like yeah + + align:start position:0% +compose what would that look like yeah + + + align:start position:0% +compose what would that look like yeah +which better gets to the question why do + + align:start position:0% +which better gets to the question why do + + + align:start position:0% +which better gets to the question why do +things die yeah right well I mean things + + align:start position:0% +things die yeah right well I mean things + + + align:start position:0% +things die yeah right well I mean things +would die but then they just sit there + + align:start position:0% +would die but then they just sit there + + + align:start position:0% +would die but then they just sit there +right why why do things decompose and if + + align:start position:0% +right why why do things decompose and if + + + align:start position:0% +right why why do things decompose and if +if you know they had to be broken down + + align:start position:0% +if you know they had to be broken down + + + align:start position:0% +if you know they had to be broken down +by other means in just bacteria right + + align:start position:0% +by other means in just bacteria right + + + align:start position:0% +by other means in just bacteria right +the decomposition cycle right what that + + align:start position:0% +the decomposition cycle right what that + + + align:start position:0% +the decomposition cycle right what that +would mean for like carbon and nitrogen + + align:start position:0% +would mean for like carbon and nitrogen + + + align:start position:0% +would mean for like carbon and nitrogen +Cycles that's much conceptually harder + + align:start position:0% +Cycles that's much conceptually harder + + + align:start position:0% +Cycles that's much conceptually harder +than of concrete broccoli it is but you + + align:start position:0% +than of concrete broccoli it is but you + + + align:start position:0% +than of concrete broccoli it is but you +can allude to this in the exploration of + + align:start position:0% +can allude to this in the exploration of + + + align:start position:0% +can allude to this in the exploration of +that broccoli do you know what I mean by + + align:start position:0% +that broccoli do you know what I mean by + + + align:start position:0% +that broccoli do you know what I mean by +looking at one thing really really + + align:start position:0% +looking at one thing really really + + + align:start position:0% +looking at one thing really really +deeply you actually allow yourself the + + align:start position:0% +deeply you actually allow yourself the + + + align:start position:0% +deeply you actually allow yourself the +ability to abstract from it that I think + + align:start position:0% +ability to abstract from it that I think + + + align:start position:0% +ability to abstract from it that I think +for a few minutes about that broccoli a + + align:start position:0% +for a few minutes about that broccoli a + + + align:start position:0% +for a few minutes about that broccoli a +little more + + align:start position:0% +little more + + + align:start position:0% +little more +cool how are you + + align:start position:0% +cool how are you + + + align:start position:0% +cool how are you +doing after talking to the I realiz + + align:start position:0% +doing after talking to the I realiz + + + align:start position:0% +doing after talking to the I realiz +probably my initial I want + + align:start position:0% + + + + align:start position:0% + +to little talking about how we go from + + align:start position:0% + + + + align:start position:0% + +think of that and another topic Rel + + align:start position:0% +think of that and another topic Rel + + + align:start position:0% +think of that and another topic Rel +when the + + align:start position:0% +when the + + + align:start position:0% +when the +one videos concepts of time travel mhm + + align:start position:0% +one videos concepts of time travel mhm + + + align:start position:0% +one videos concepts of time travel mhm +but um is time travel even possible is + + align:start position:0% +but um is time travel even possible is + + + align:start position:0% +but um is time travel even possible is +that the question no not really more + + align:start position:0% +that the question no not really more + + + align:start position:0% +that the question no not really more +more along the lines of problems with + + align:start position:0% +more along the lines of problems with + + + align:start position:0% +more along the lines of problems with +time traveling like for example that's + + align:start position:0% +time traveling like for example that's + + + align:start position:0% +time traveling like for example that's +the grandfather Paradox and then there + + align:start position:0% +the grandfather Paradox and then there + + + align:start position:0% +the grandfather Paradox and then there +are other + + align:start position:0% +are other + + + align:start position:0% +are other +the mul Universe + + align:start position:0% + + + + align:start position:0% + +mul but I mean even the idea of like is + + align:start position:0% +mul but I mean even the idea of like is + + + align:start position:0% +mul but I mean even the idea of like is +time travel possible is a really cool + + align:start position:0% +time travel possible is a really cool + + + align:start position:0% +time travel possible is a really cool +concept but it's really right that's why + + align:start position:0% +concept but it's really right that's why + + + align:start position:0% +concept but it's really right that's why +I decided not to Del into time travel + + align:start position:0% +I decided not to Del into time travel + + + align:start position:0% +I decided not to Del into time travel +itself uh if it's possible and rather + + align:start position:0% +itself uh if it's possible and rather + + + align:start position:0% +itself uh if it's possible and rather +looking at what happened what concepts + + align:start position:0% +looking at what happened what concepts + + + align:start position:0% +looking at what happened what concepts +but I think maybe it's I think you're + + align:start position:0% +but I think maybe it's I think you're + + + align:start position:0% +but I think maybe it's I think you're +still Doo broad yeah what tell me more + + align:start position:0% +still Doo broad yeah what tell me more + + + align:start position:0% +still Doo broad yeah what tell me more +about what you actually do in your + + align:start position:0% +about what you actually do in your + + + align:start position:0% +about what you actually do in your +studies + + align:start position:0% +studies + + + align:start position:0% +studies +but but what about like there's got to + + align:start position:0% +but but what about like there's got to + + + align:start position:0% +but but what about like there's got to +be something in there that's really + + align:start position:0% +be something in there that's really + + + align:start position:0% +be something in there that's really +exciting to you that you could + + align:start position:0% +exciting to you that you could + + + align:start position:0% +exciting to you that you could +explore I think yeah but I I really + + align:start position:0% +explore I think yeah but I I really + + + align:start position:0% +explore I think yeah but I I really +doubt kids but or even L lay men want to + + align:start position:0% +doubt kids but or even L lay men want to + + + align:start position:0% +doubt kids but or even L lay men want to +see how a computer filter information + + align:start position:0% +see how a computer filter information + + + align:start position:0% +see how a computer filter information +cuz mostly I do a so it's a lot it's to + + align:start position:0% +cuz mostly I do a so it's a lot it's to + + + align:start position:0% +cuz mostly I do a so it's a lot it's to +do a lot with like filtering of + + align:start position:0% +do a lot with like filtering of + + + align:start position:0% +do a lot with like filtering of +information and deciding what to do on + + align:start position:0% +information and deciding what to do on + + + align:start position:0% +information and deciding what to do on +information but I mean this came up with + + align:start position:0% +information but I mean this came up with + + + align:start position:0% +information but I mean this came up with +it with a different Group which is when + + align:start position:0% +it with a different Group which is when + + + align:start position:0% +it with a different Group which is when +I type and filtering information is + + align:start position:0% +I type and filtering information is + + + align:start position:0% +I type and filtering information is +actually really interesting like when I + + align:start position:0% +actually really interesting like when I + + + align:start position:0% +actually really interesting like when I +Google something how does my computer + + align:start position:0% +Google something how does my computer + + + align:start position:0% +Google something how does my computer +know what to send me that's actually a + + align:start position:0% +know what to send me that's actually a + + + align:start position:0% +know what to send me that's actually a +really interesting question right if I'm + + align:start position:0% +really interesting question right if I'm + + + align:start position:0% +really interesting question right if I'm +using Google Shopper how does it + + align:start position:0% +using Google Shopper how does it + + + align:start position:0% +using Google Shopper how does it +know you know and explaining that like a + + align:start position:0% +know you know and explaining that like a + + + align:start position:0% +know you know and explaining that like a +system that's actually really + + align:start position:0% +system that's actually really + + + align:start position:0% +system that's actually really +interesting bringing to L + + align:start position:0% +interesting bringing to L + + + align:start position:0% +interesting bringing to L +those but but important right + + align:start position:0% +those but but important right + + + align:start position:0% +those but but important right +I mean is it possible to pick something + + align:start position:0% +I mean is it possible to pick something + + + align:start position:0% +I mean is it possible to pick something +that you do that's conceptually hard but + + align:start position:0% +that you do that's conceptually hard but + + + align:start position:0% +that you do that's conceptually hard but +to really flesh it out to challenge + + align:start position:0% +to really flesh it out to challenge + + + align:start position:0% +to really flesh it out to challenge +yourself to think about how to describe + + align:start position:0% +yourself to think about how to describe + + + align:start position:0% +yourself to think about how to describe +that or show that like the train concept + + align:start position:0% +that or show that like the train concept + + + align:start position:0% +that or show that like the train concept +a little bit hard but I kind of got it + + align:start position:0% +a little bit hard but I kind of got it + + + align:start position:0% +a little bit hard but I kind of got it +right is there something that you could + + align:start position:0% +right is there something that you could + + + align:start position:0% +right is there something that you could +something in your work that you're + + align:start position:0% +something in your work that you're + + + align:start position:0% +something in your work that you're +passionate about you know a lot about + + align:start position:0% +passionate about you know a lot about + + + align:start position:0% +passionate about you know a lot about +that you think is actually really useful + + align:start position:0% +that you think is actually really useful + + + align:start position:0% +that you think is actually really useful +for the public to know as well + + align:start position:0% + + + + align:start position:0% + +um I honestly don't think many things my + + align:start position:0% +um I honestly don't think many things my + + + align:start position:0% +um I honestly don't think many things my +degrees is relevant to the public um + + align:start position:0% +degrees is relevant to the public um + + + align:start position:0% +degrees is relevant to the public um +what do you want to do with your degree + + align:start position:0% +what do you want to do with your degree + + + align:start position:0% +what do you want to do with your degree +a lot of things probably robotics itself + + align:start position:0% +a lot of things probably robotics itself + + + align:start position:0% +a lot of things probably robotics itself +okay robots are really cool topics so + + align:start position:0% +okay robots are really cool topics so + + + align:start position:0% +okay robots are really cool topics so +what about what what about + + align:start position:0% +what about what what about + + + align:start position:0% +what about what what about +robots how they filter information + + align:start position:0% +robots how they filter information + + + align:start position:0% +robots how they filter information +probably how they input how they take + + align:start position:0% +probably how they input how they take + + + align:start position:0% +probably how they input how they take +inputs in it how they decide what to do + + align:start position:0% +inputs in it how they decide what to do + + + align:start position:0% +inputs in it how they decide what to do +great this is this is an awesome topic + + align:start position:0% +great this is this is an awesome topic + + + align:start position:0% +great this is this is an awesome topic +can you think of one very specific + + align:start position:0% +can you think of one very specific + + + align:start position:0% +can you think of one very specific +question that you could answer ask a + + align:start position:0% +question that you could answer ask a + + + align:start position:0% +question that you could answer ask a +robot and how it would be able to figure + + align:start position:0% +robot and how it would be able to figure + + + align:start position:0% +robot and how it would be able to figure +out how to answer it yes or no have you + + align:start position:0% +out how to answer it yes or no have you + + + align:start position:0% +out how to answer it yes or no have you +ever designed a simple robot or a simple + + align:start position:0% + + + + align:start position:0% + +machine do that or like is there any + + align:start position:0% +machine do that or like is there any + + + align:start position:0% +machine do that or like is there any +way very simply showing how a machine + + align:start position:0% +way very simply showing how a machine + + + align:start position:0% +way very simply showing how a machine +makes the decision and so so the + + align:start position:0% +makes the decision and so so the + + + align:start position:0% +makes the decision and so so the +argument is + + align:start position:0% +argument is + + + align:start position:0% +argument is +that I'm I'm trying you know what I mean + + align:start position:0% +that I'm I'm trying you know what I mean + + + align:start position:0% +that I'm I'm trying you know what I mean +like what I'm trying to push you to do + + align:start position:0% +like what I'm trying to push you to do + + + align:start position:0% +like what I'm trying to push you to do +is think about if Robotics are exciting + + align:start position:0% +is think about if Robotics are exciting + + + align:start position:0% +is think about if Robotics are exciting +to you is there one ke the concept + + align:start position:0% +to you is there one ke the concept + + + align:start position:0% +to you is there one ke the concept +behind quite abstract that's the + + align:start position:0% +behind quite abstract that's the + + + align:start position:0% +behind quite abstract that's the +thing they're really like it's + + align:start position:0% +thing they're really like it's + + + align:start position:0% +thing they're really like it's +mathematically heavy that's what I'm + + align:start position:0% +mathematically heavy that's what I'm + + + align:start position:0% +mathematically heavy that's what I'm +thinking of I'm not sure how how really + + align:start position:0% +thinking of I'm not sure how how really + + + align:start position:0% +thinking of I'm not sure how how really +it can be brought across or it should be + + align:start position:0% +it can be brought across or it should be + + + align:start position:0% +it can be brought across or it should be +brought across in so I was actually + + align:start position:0% +brought across in so I was actually + + + align:start position:0% +brought across in so I was actually +exploring something maybe a bit more + + align:start position:0% +exploring something maybe a bit more + + + align:start position:0% +exploring something maybe a bit more +what maybe more along the lines of pain + + align:start position:0% +what maybe more along the lines of pain + + + align:start position:0% +what maybe more along the lines of pain +cuz I um I was a medic back in the + + align:start position:0% +cuz I um I was a medic back in the + + + align:start position:0% +cuz I um I was a medic back in the +military so dealt with a lot like every + + align:start position:0% +military so dealt with a lot like every + + + align:start position:0% +military so dealt with a lot like every +day we see people coming in looking for + + align:start position:0% +day we see people coming in looking for + + + align:start position:0% +day we see people coming in looking for +pain I to maybe a bit more like for + + align:start position:0% +pain I to maybe a bit more like for + + + align:start position:0% +pain I to maybe a bit more like for +people to understand better like do I + + align:start position:0% +people to understand better like do I + + + align:start position:0% +people to understand better like do I +take an anvil or an aspirin like do I + + align:start position:0% +take an anvil or an aspirin like do I + + + align:start position:0% +take an anvil or an aspirin like do I +take an they're roughly the same thing + + align:start position:0% +take an they're roughly the same thing + + + align:start position:0% +take an they're roughly the same thing +like what what is the difference between + + align:start position:0% +like what what is the difference between + + + align:start position:0% +like what what is the difference between +two kinds of medication why do we take + + align:start position:0% +two kinds of medication why do we take + + + align:start position:0% +two kinds of medication why do we take +one more than the other but which is + + align:start position:0% +one more than the other but which is + + + align:start position:0% +one more than the other but which is +actually more useful than the other kind + + align:start position:0% +actually more useful than the other kind + + + align:start position:0% +actually more useful than the other kind +of thing so it's it's more like it's + + align:start position:0% +of thing so it's it's more like it's + + + align:start position:0% +of thing so it's it's more like it's +like Dr MD kind of thing a bit more + + align:start position:0% +like Dr MD kind of thing a bit more + + + align:start position:0% +like Dr MD kind of thing a bit more +explanatory rather than + + align:start position:0% +explanatory rather than + + + align:start position:0% +explanatory rather than +just but I'd hate for you to not talk + + align:start position:0% +just but I'd hate for you to not talk + + + align:start position:0% +just but I'd hate for you to not talk +about robots when that's what you're + + align:start position:0% +about robots when that's what you're + + + align:start position:0% +about robots when that's what you're +studying and that's what you're + + align:start position:0% +studying and that's what you're + + + align:start position:0% +studying and that's what you're +passionate about just because it's + + align:start position:0% +passionate about just because it's + + + align:start position:0% +passionate about just because it's +hard it's all I don't think it's because + + align:start position:0% +hard it's all I don't think it's because + + + align:start position:0% +hard it's all I don't think it's because +it's hard I mean if it were to be an + + align:start position:0% +it's hard I mean if it were to be an + + + align:start position:0% +it's hard I mean if it were to be an +instructional video for someone in my + + align:start position:0% +instructional video for someone in my + + + align:start position:0% +instructional video for someone in my +level maybe it's not undoable but but is + + align:start position:0% +level maybe it's not undoable but but is + + + align:start position:0% +level maybe it's not undoable but but is +there anything with in robots that you + + align:start position:0% +there anything with in robots that you + + + align:start position:0% +there anything with in robots that you +think is a cool idea simple a simple + + align:start position:0% +think is a cool idea simple a simple + + + align:start position:0% +think is a cool idea simple a simple +simple simple something so not + + align:start position:0% +simple simple something so not + + + align:start position:0% +simple simple something so not +everything about how a robot works but + + align:start position:0% +everything about how a robot works but + + + align:start position:0% +everything about how a robot works but +but but even how to get I'm realizing + + align:start position:0% +but but even how to get I'm realizing + + + align:start position:0% +but but even how to get I'm realizing +just something very I don't know your + + align:start position:0% +just something very I don't know your + + + align:start position:0% +just something very I don't know your +world enough to be able to help you + + align:start position:0% +world enough to be able to help you + + + align:start position:0% +world enough to be able to help you +think about what is that thing but I + + align:start position:0% +think about what is that thing but I + + + align:start position:0% +think about what is that thing but I +challenge you to think for a few minutes + + align:start position:0% +challenge you to think for a few minutes + + + align:start position:0% +challenge you to think for a few minutes +really deeply about what what within + + align:start position:0% +really deeply about what what within + + + align:start position:0% +really deeply about what what within +robots is a simple enough concept do you + + align:start position:0% +robots is a simple enough concept do you + + + align:start position:0% +robots is a simple enough concept do you +have an idea actually just listen in and + + align:start position:0% +have an idea actually just listen in and + + + align:start position:0% +have an idea actually just listen in and +I know something I think is really + + align:start position:0% +I know something I think is really + + + align:start position:0% +I know something I think is really +cool basic refers to all the way this + + align:start position:0% +cool basic refers to all the way this + + + align:start position:0% +cool basic refers to all the way this +might still be too complex but + + align:start position:0% + + + + align:start position:0% + +probability and based on the probability + + align:start position:0% +probability and based on the probability + + + align:start position:0% +probability and based on the probability +of what what something happening then + + align:start position:0% +of what what something happening then + + + align:start position:0% +of what what something happening then +you you predict whether it's like a + + align:start position:0% +you you predict whether it's like a + + + align:start position:0% +you you predict whether it's like a +robot has to + + align:start position:0% +robot has to + + + align:start position:0% +robot has to +constru + + align:start position:0% + + + + align:start position:0% + +do not my favorite project done yeah + + align:start position:0% +do not my favorite project done yeah + + + align:start position:0% +do not my favorite project done yeah +I but if you can think maybe you + + align:start position:0% +I but if you can think maybe you + + + align:start position:0% +I but if you can think maybe you +brainstorm for a second about robots to + + align:start position:0% +brainstorm for a second about robots to + + + align:start position:0% +brainstorm for a second about robots to +see if you can get narrow enough that + + align:start position:0% +see if you can get narrow enough that + + + align:start position:0% +see if you can get narrow enough that +it's a + + align:start position:0% +it's a + + + align:start position:0% +it's a +concept I mean I think that there's a + + align:start position:0% +concept I mean I think that there's a + + + align:start position:0% +concept I mean I think that there's a +Seedling here right but like what is + + align:start position:0% +Seedling here right but like what is + + + align:start position:0% +Seedling here right but like what is +What is the + + align:start position:0% +What is the + + + align:start position:0% +What is the +relatability and the drama that's + + align:start position:0% +relatability and the drama that's + + + align:start position:0% +relatability and the drama that's +getting people in right because I I + + align:start position:0% +getting people in right because I I + + + align:start position:0% +getting people in right because I I +personally think that it's fascinating + + align:start position:0% +personally think that it's fascinating + + + align:start position:0% +personally think that it's fascinating +that we live in the 21st century with + + align:start position:0% +that we live in the 21st century with + + + align:start position:0% +that we live in the 21st century with +all these super commes yet this + + align:start position:0% +all these super commes yet this + + + align:start position:0% +all these super commes yet this +seemingly basic problem of you have + + align:start position:0% +seemingly basic problem of you have + + + align:start position:0% +seemingly basic problem of you have +constraints XYZ you can only work four + + align:start position:0% +constraints XYZ you can only work four + + + align:start position:0% +constraints XYZ you can only work four +hours in a day you need to make chairs + + align:start position:0% +hours in a day you need to make chairs + + + align:start position:0% +hours in a day you need to make chairs +and you need to make tables how what's + + align:start position:0% +and you need to make tables how what's + + + align:start position:0% +and you need to make tables how what's +the optimal number of chairs and tables + + align:start position:0% +the optimal number of chairs and tables + + + align:start position:0% +the optimal number of chairs and tables +to make like that seems like a question + + align:start position:0% +to make like that seems like a question + + + align:start position:0% +to make like that seems like a question +that we would be able to solve and the + + align:start position:0% +that we would be able to solve and the + + + align:start position:0% +that we would be able to solve and the +fact that we theoretically actually + + align:start position:0% +fact that we theoretically actually + + + align:start position:0% +fact that we theoretically actually +can't + + align:start position:0% +can't + + + align:start position:0% +can't +is um is interesting except there's not + + align:start position:0% +is um is interesting except there's not + + + align:start position:0% +is um is interesting except there's not +enough at stake in that example right + + align:start position:0% +enough at stake in that example right + + + align:start position:0% +enough at stake in that example right +like people will say oh we lose a couple + + align:start position:0% +like people will say oh we lose a couple + + + align:start position:0% +like people will say oh we lose a couple +cents on making chairs like that's no + + align:start position:0% +cents on making chairs like that's no + + + align:start position:0% +cents on making chairs like that's no +big deal but if you say something like + + align:start position:0% +big deal but if you say something like + + + align:start position:0% +big deal but if you say something like +because integer programs can't be solved + + align:start position:0% +because integer programs can't be solved + + + align:start position:0% +because integer programs can't be solved +right now like this is what's preventing + + align:start position:0% +right now like this is what's preventing + + + align:start position:0% +right now like this is what's preventing +us from knowing um like this is the + + align:start position:0% +us from knowing um like this is the + + + align:start position:0% +us from knowing um like this is the +reason or one of the reasons why + + align:start position:0% +reason or one of the reasons why + + + align:start position:0% +reason or one of the reasons why +companies can only achieve like certain + + align:start position:0% +companies can only achieve like certain + + + align:start position:0% +companies can only achieve like certain +profit margins for instance like what + + align:start position:0% +profit margins for instance like what + + + align:start position:0% +profit margins for instance like what +would happen if we could solve in + + align:start position:0% +would happen if we could solve in + + + align:start position:0% +would happen if we could solve in +programs like what what would happen to + + align:start position:0% +programs like what what would happen to + + + align:start position:0% +programs like what what would happen to +humanity I guess you + + align:start position:0% +humanity I guess you + + + align:start position:0% +humanity I guess you +know I do you know I mean I don't know + + align:start position:0% +know I do you know I mean I don't know + + + align:start position:0% +know I do you know I mean I don't know +it just means + + align:start position:0% +it just means + + + align:start position:0% +it just means +that when they say you can't solve it + + align:start position:0% +that when they say you can't solve it + + + align:start position:0% +that when they say you can't solve it +it's probably just saying that + + align:start position:0% +it's probably just saying that + + + align:start position:0% +it's probably just saying that +um you can't solve it easier than the + + align:start position:0% +um you can't solve it easier than the + + + align:start position:0% +um you can't solve it easier than the +the you you actually can solve it but + + align:start position:0% +the you you actually can solve it but + + + align:start position:0% +the you you actually can solve it but +the the way to solve it is just just go + + align:start position:0% +the the way to solve it is just just go + + + align:start position:0% +the the way to solve it is just just go +through every single point on the + + align:start position:0% +through every single point on the + + + align:start position:0% +through every single point on the +so it's very inefficient yeah it's just + + align:start position:0% +so it's very inefficient yeah it's just + + + align:start position:0% +so it's very inefficient yeah it's just +compet so like it limits us to the types + + align:start position:0% +compet so like it limits us to the types + + + align:start position:0% +compet so like it limits us to the types +of problems yes you can can solve it for + + align:start position:0% +of problems yes you can can solve it for + + + align:start position:0% +of problems yes you can can solve it for +like very small variables like in this + + align:start position:0% +like very small variables like in this + + + align:start position:0% +like very small variables like in this +case it's two variabl so you can solve + + align:start position:0% +case it's two variabl so you can solve + + + align:start position:0% +case it's two variabl so you can solve +it yeah but you can't solve like 20 Yeah + + align:start position:0% +it yeah but you can't solve like 20 Yeah + + + align:start position:0% +it yeah but you can't solve like 20 Yeah +the more variables then like mention + + align:start position:0% +the more variables then like mention + + + align:start position:0% +the more variables then like mention +this before is I + + align:start position:0% + + + + align:start position:0% + +think say the as long as the number of + + align:start position:0% +think say the as long as the number of + + + align:start position:0% +think say the as long as the number of +variables increases number of number of + + align:start position:0% +variables increases number of number of + + + align:start position:0% +variables increases number of number of +times you must try exponentially that + + align:start position:0% +times you must try exponentially that + + + align:start position:0% +times you must try exponentially that +you can't really you can't really solve + + align:start position:0% +you can't really you can't really solve + + + align:start position:0% +you can't really you can't really solve +the problem a concept called + + align:start position:0% +the problem a concept called + + + align:start position:0% +the problem a concept called +NP so it's it's about categorizing a + + align:start position:0% +NP so it's it's about categorizing a + + + align:start position:0% +NP so it's it's about categorizing a +problem how difficult a problem is and + + align:start position:0% +problem how difficult a problem is and + + + align:start position:0% +problem how difficult a problem is and +if it's harder than this problem I think + + align:start position:0% +if it's harder than this problem I think + + + align:start position:0% +if it's harder than this problem I think +that's like every problem the world + + align:start position:0% +that's like every problem the world + + + align:start position:0% +that's like every problem the world +every problem in the world can be made + + align:start position:0% +every problem in the world can be made + + + align:start position:0% +every problem in the world can be made +into a type of problem called I'm + + align:start position:0% +into a type of problem called I'm + + + align:start position:0% +into a type of problem called I'm +forgetting I think like maybe this might + + align:start position:0% +forgetting I think like maybe this might + + + align:start position:0% +forgetting I think like maybe this might +this might be specific enough yeah this + + align:start position:0% +this might be specific enough yeah this + + + align:start position:0% +this might be specific enough yeah this +sounds really + + align:start position:0% +sounds really + + + align:start position:0% +sounds really +because like I think + + align:start position:0% +because like I think + + + align:start position:0% +because like I think +when Elizabeth was talking what I was + + align:start position:0% +when Elizabeth was talking what I was + + + align:start position:0% +when Elizabeth was talking what I was +thinking of is like we've all seen in + + align:start position:0% +thinking of is like we've all seen in + + + align:start position:0% +thinking of is like we've all seen in +like basic algebra classes we're going + + align:start position:0% +like basic algebra classes we're going + + + align:start position:0% +like basic algebra classes we're going +to make X number of tables y number of + + align:start position:0% +to make X number of tables y number of + + + align:start position:0% +to make X number of tables y number of +chairs in this many hours solve for each + + align:start position:0% +chairs in this many hours solve for each + + + align:start position:0% +chairs in this many hours solve for each +variable but when it comes to real life + + align:start position:0% +variable but when it comes to real life + + + align:start position:0% +variable but when it comes to real life +you can't break it down to just tables + + align:start position:0% +you can't break it down to just tables + + + align:start position:0% +you can't break it down to just tables +and chairs and real life is really messy + + align:start position:0% +and chairs and real life is really messy + + + align:start position:0% +and chairs and real life is really messy +with so many variables which is why we + + align:start position:0% +with so many variables which is why we + + + align:start position:0% +with so many variables which is why we +can't predict these things and so I + + align:start position:0% +can't predict these things and so I + + + align:start position:0% +can't predict these things and so I +think that in itself is a really + + align:start position:0% +think that in itself is a really + + + align:start position:0% +think that in itself is a really +interesting concept to explain because + + align:start position:0% +interesting concept to explain because + + + align:start position:0% +interesting concept to explain because +people don't necessarily think of real + + align:start position:0% +people don't necessarily think of real + + + align:start position:0% +people don't necessarily think of real +life it's a little bit elri that way we + + align:start position:0% +life it's a little bit elri that way we + + + align:start position:0% +life it's a little bit elri that way we +we can describe sitation + + align:start position:0% +we can describe sitation + + + align:start position:0% +we can describe sitation +with hypothetically and those are + + align:start position:0% +with hypothetically and those are + + + align:start position:0% +with hypothetically and those are +problems that would be awesome if we + + align:start position:0% +problems that would be awesome if we + + + align:start position:0% +problems that would be awesome if we +could solve because we would have such + + align:start position:0% +could solve because we would have such + + + align:start position:0% +could solve because we would have such +like a greater understanding how system + + align:start position:0% +like a greater understanding how system + + + align:start position:0% +like a greater understanding how system +behavior of you know as of right now + + align:start position:0% +behavior of you know as of right now + + + align:start position:0% +behavior of you know as of right now +where we are even though we can solve + + align:start position:0% +where we are even though we can solve + + + align:start position:0% +where we are even though we can solve +simple problems like if there are two + + align:start position:0% +simple problems like if there are two + + + align:start position:0% +simple problems like if there are two +it's a lot biological engineer begin to + + align:start position:0% +it's a lot biological engineer begin to + + + align:start position:0% +it's a lot biological engineer begin to +Fathom what this meis actually getting + + align:start position:0% +Fathom what this meis actually getting + + + align:start position:0% +Fathom what this meis actually getting +sick + + align:start position:0% +sick + + + align:start position:0% +sick +comput but kind took you away from yeah + + align:start position:0% +comput but kind took you away from yeah + + + align:start position:0% +comput but kind took you away from yeah +yeah okay okay and I'm not I'm not ruing + + align:start position:0% +yeah okay okay and I'm not I'm not ruing + + + align:start position:0% +yeah okay okay and I'm not I'm not ruing +it out yeah I just kind of like the idea + + align:start position:0% +it out yeah I just kind of like the idea + + + align:start position:0% +it out yeah I just kind of like the idea +that how and I was thinking how if every + + align:start position:0% +that how and I was thinking how if every + + + align:start position:0% +that how and I was thinking how if every +bone can like what two set or three set + + align:start position:0% +bone can like what two set or three set + + + align:start position:0% +bone can like what two set or three set +orations and stuff let's think of some + + align:start position:0% +orations and stuff let's think of some + + + align:start position:0% +orations and stuff let's think of some +of the other other ideas then that came + + align:start position:0% +of the other other ideas then that came + + + align:start position:0% +of the other other ideas then that came +out from the kids if it can be + + align:start position:0% +out from the kids if it can be + + + align:start position:0% +out from the kids if it can be +possible to to solve it in in a + + align:start position:0% +possible to to solve it in in a + + + align:start position:0% +possible to to solve it in in a +reasonable amount of time but if it's + + align:start position:0% +reasonable amount of time but if it's + + + align:start position:0% +reasonable amount of time but if it's +trees set they're alled + + align:start position:0% +trees set they're alled + + + align:start position:0% +trees set they're alled +so what are the actual concrete + + align:start position:0% +so what are the actual concrete + + + align:start position:0% +so what are the actual concrete +applications of computational complexity + + align:start position:0% +applications of computational complexity + + + align:start position:0% +applications of computational complexity +like what are the problems that can't be + + align:start position:0% +like what are the problems that can't be + + + align:start position:0% +like what are the problems that can't be +solved by computers yeah so my + + align:start position:0% +solved by computers yeah so my + + + align:start position:0% +solved by computers yeah so my +reasoning like indust interesting + + align:start position:0% +reasoning like indust interesting + + + align:start position:0% +reasoning like indust interesting +question will + + align:start position:0% +question will + + + align:start position:0% +question will +be why Google + + align:start position:0% +be why Google + + + align:start position:0% +be why Google +can why Google like why why search what + + align:start position:0% +can why Google like why why search what + + + align:start position:0% +can why Google like why why search what +about submarines they're really + + align:start position:0% +about submarines they're really + + + align:start position:0% +about submarines they're really +intelligence + + align:start position:0% +intelligence + + + align:start position:0% +intelligence +looks question because they both started + + align:start position:0% +looks question because they both started + + + align:start position:0% +looks question because they both started +at the same time period but look at what + + align:start position:0% +at the same time period but look at what + + + align:start position:0% +at the same time period but look at what +appell have gotten to like what how to + + align:start position:0% +appell have gotten to like what how to + + + align:start position:0% +appell have gotten to like what how to +that's the most we have but Google is + + align:start position:0% +that's the most we have but Google is + + + align:start position:0% +that's the most we have but Google is +now a huge company so that's a cool + + align:start position:0% +now a huge company so that's a cool + + + align:start position:0% +now a huge company so that's a cool +topic my son has a submarine in his + + align:start position:0% +topic my son has a submarine in his + + + align:start position:0% +topic my son has a submarine in his +that's really + + align:start position:0% +that's really + + + align:start position:0% +that's really +cool I don't know I mean and we have + + align:start position:0% +cool I don't know I mean and we have + + + align:start position:0% +cool I don't know I mean and we have +something like Google the thing like the + + align:start position:0% +something like Google the thing like the + + + align:start position:0% +something like Google the thing like the +thing that I worry about with this + + align:start position:0% +thing that I worry about with this + + + align:start position:0% +thing that I worry about with this +reason kids kids don't these are these + + align:start position:0% +reason kids kids don't these are these + + + align:start position:0% +reason kids kids don't these are these +are things that kids much more difficult + + align:start position:0% +are things that kids much more difficult + + + align:start position:0% +are things that kids much more difficult +you know like they're cool from probably + + align:start position:0% +you know like they're cool from probably + + + align:start position:0% +you know like they're cool from probably +a science perspective + + align:start position:0% +a science perspective + + + align:start position:0% +a science perspective +typical Behavior you know like I could + + align:start position:0% +typical Behavior you know like I could + + + align:start position:0% +typical Behavior you know like I could +really and I I mean that as a a good way + + align:start position:0% +really and I I mean that as a a good way + + + align:start position:0% +really and I I mean that as a a good way +that like that seems like understanding + + align:start position:0% +that like that seems like understanding + + + align:start position:0% +that like that seems like understanding +because again the S and Float concept is + + align:start position:0% +because again the S and Float concept is + + + align:start position:0% +because again the S and Float concept is +one that's a really important concept + + align:start position:0% +one that's a really important concept + + + align:start position:0% +one that's a really important concept +for kids to get like about why does + + align:start position:0% +for kids to get like about why does + + + align:start position:0% +for kids to get like about why does +something sink and why does + + align:start position:0% +something sink and why does + + + align:start position:0% +something sink and why does +something grab on to like at whatever + + align:start position:0% +something grab on to like at whatever + + + align:start position:0% +something grab on to like at whatever +they are like eventually they're going + + align:start position:0% +they are like eventually they're going + + + align:start position:0% +they are like eventually they're going +to have use go so many people have cell + + align:start position:0% +to have use go so many people have cell + + + align:start position:0% +to have use go so many people have cell +phones noway that they've at least heard + + align:start position:0% +phones noway that they've at least heard + + + align:start position:0% +phones noway that they've at least heard +of Siri and I feel like + + align:start position:0% +of Siri and I feel like + + + align:start position:0% +of Siri and I feel like +you can kind of generalize a general + + align:start position:0% +you can kind of generalize a general + + + align:start position:0% +you can kind of generalize a general +population lumps technology into one + + align:start position:0% +population lumps technology into one + + + align:start position:0% +population lumps technology into one +like big mysterious closed box where + + align:start position:0% +like big mysterious closed box where + + + align:start position:0% +like big mysterious closed box where +it's like okay I can I can type in + + align:start position:0% +it's like okay I can I can type in + + + align:start position:0% +it's like okay I can I can type in +something on Google and I can ask + + align:start position:0% +something on Google and I can ask + + + align:start position:0% +something on Google and I can ask +seriously and that produces the same + + align:start position:0% +seriously and that produces the same + + + align:start position:0% +seriously and that produces the same +effect they're virtually the same to + + align:start position:0% +effect they're virtually the same to + + + align:start position:0% +effect they're virtually the same to +their mind and so if you can hard blow + + align:start position:0% +their mind and so if you can hard blow + + + align:start position:0% +their mind and so if you can hard blow +their minds by telling them well no + + align:start position:0% +their minds by telling them well no + + + align:start position:0% +their minds by telling them well no +there's a big difference between the two + + align:start position:0% +there's a big difference between the two + + + align:start position:0% +there's a big difference between the two +these two + + align:start position:0% +these two + + + align:start position:0% +these two +techologies and like how they've + + align:start position:0% +techologies and like how they've + + + align:start position:0% +techologies and like how they've +developed even though they started at + + align:start position:0% +developed even though they started at + + + align:start position:0% +developed even though they started at +the same movie that I've seen + + align:start position:0% +the same movie that I've seen + + + align:start position:0% +the same movie that I've seen +skiing on the water and that's what I'm + + align:start position:0% +skiing on the water and that's what I'm + + + align:start position:0% +skiing on the water and that's what I'm +imag they use every I don't know why + + align:start position:0% +imag they use every I don't know why + + + align:start position:0% +imag they use every I don't know why +that would I + + align:start position:0% +that would I + + + align:start position:0% +that would I +mean understand that part but the videos + + align:start position:0% +mean understand that part but the videos + + + align:start position:0% +mean understand that part but the videos +are not for sixth graders necessarily + + align:start position:0% +are not for sixth graders necessarily + + + align:start position:0% +are not for sixth graders necessarily +it's for people with the sixth grade + + align:start position:0% +it's for people with the sixth grade + + + align:start position:0% +it's for people with the sixth grade +knowledge and a sixth grader will be + + align:start position:0% +knowledge and a sixth grader will be + + + align:start position:0% +knowledge and a sixth grader will be +able to watch this I know you're saying + + align:start position:0% +able to watch this I know you're saying + + + align:start position:0% +able to watch this I know you're saying +like + + align:start position:0% +like + + + align:start position:0% +like +yeah and you don't have + + align:start position:0% +yeah and you don't have + + + align:start position:0% +yeah and you don't have +to you don't have to baby anything down + + align:start position:0% +to you don't have to baby anything down + + + align:start position:0% +to you don't have to baby anything down +the audience you know what I mean like + + align:start position:0% +the audience you know what I mean like + + + align:start position:0% +the audience you know what I mean like +you don't have to talk to them like + + align:start position:0% +you don't have to talk to them like + + + align:start position:0% +you don't have to talk to them like +they're T because that helps encourage + + align:start position:0% +they're T because that helps encourage + + + align:start position:0% +they're T because that helps encourage +the conversations afterward too because + + align:start position:0% +the conversations afterward too because + + + align:start position:0% +the conversations afterward too because +like when I watch a video about + + align:start position:0% +like when I watch a video about + + + align:start position:0% +like when I watch a video about +something that I'm unfamiliar with if I + + align:start position:0% +something that I'm unfamiliar with if I + + + align:start position:0% +something that I'm unfamiliar with if I +want to learn more I'll go out and + + align:start position:0% +want to learn more I'll go out and + + + align:start position:0% +want to learn more I'll go out and +search the words that I don't know and + + align:start position:0% +search the words that I don't know and + + + align:start position:0% +search the words that I don't know and +like as you saw with the sixth graders + + align:start position:0% +like as you saw with the sixth graders + + + align:start position:0% +like as you saw with the sixth graders +maybe they kept asking questions if + + align:start position:0% +maybe they kept asking questions if + + + align:start position:0% +maybe they kept asking questions if +they're curious about something they'll + + align:start position:0% +they're curious about something they'll + + + align:start position:0% +they're curious about something they'll +keep wanting to know about things and + + align:start position:0% +keep wanting to know about things and + + + align:start position:0% +keep wanting to know about things and +so and and they're a lot more int you + + align:start position:0% +so and and they're a lot more int you + + + align:start position:0% +so and and they're a lot more int you +think sixth grade was way long ago but + + align:start position:0% +think sixth grade was way long ago but + + + align:start position:0% +think sixth grade was way long ago but +they were very like they're actually + + align:start position:0% +they were very like they're actually + + + align:start position:0% +they were very like they're actually +intelligent they're actually + + align:start position:0% +intelligent they're actually + + + align:start position:0% +intelligent they're actually +curious um so you don't want + + align:start position:0% +curious um so you don't want + + + align:start position:0% +curious um so you don't want +to take out things that you're saying + + align:start position:0% +to take out things that you're saying + + + align:start position:0% +to take out things that you're saying +just because you think it's it's too + + align:start position:0% +just because you think it's it's too + + + align:start position:0% +just because you think it's it's too +intelligent for them or it's too far + + align:start position:0% +intelligent for them or it's too far + + + align:start position:0% +intelligent for them or it's too far +above their level because if you + + align:start position:0% +above their level because if you + + + align:start position:0% +above their level because if you +transition well into it if you script it + + align:start position:0% +transition well into it if you script it + + + align:start position:0% +transition well into it if you script it +properly and do the proper buildup + + align:start position:0% +properly and do the proper buildup + + + align:start position:0% +properly and do the proper buildup +here's your introduction now these are + + align:start position:0% +here's your introduction now these are + + + align:start position:0% +here's your introduction now these are +the details I'm going to talk about then + + align:start position:0% +the details I'm going to talk about then + + + align:start position:0% +the details I'm going to talk about then +they'll remember some of those details + + align:start position:0% +they'll remember some of those details + + + align:start position:0% +they'll remember some of those details +and look up the things that they still + + align:start position:0% +and look up the things that they still + + + align:start position:0% +and look up the things that they still +want to know is it okay with just used + + align:start position:0% +want to know is it okay with just used + + + align:start position:0% +want to know is it okay with just used +the + + align:start position:0% +the + + + align:start position:0% +the +but inste of the because to say what a + + align:start position:0% +but inste of the because to say what a + + + align:start position:0% +but inste of the because to say what a +problem can become two set problem + + align:start position:0% +problem can become two set problem + + + align:start position:0% +problem can become two set problem +that's + + align:start position:0% +that's + + + align:start position:0% +that's +like yeah + + align:start position:0% +like yeah + + + align:start position:0% +like yeah +so um for tonight's assignment we're + + align:start position:0% +so um for tonight's assignment we're + + + align:start position:0% +so um for tonight's assignment we're +going to have you guys just write a + + align:start position:0% +going to have you guys just write a + + + align:start position:0% +going to have you guys just write a +rough draft of a script and at this + + align:start position:0% +rough draft of a script and at this + + + align:start position:0% +rough draft of a script and at this +point I think it's okay if you want to + + align:start position:0% +point I think it's okay if you want to + + + align:start position:0% +point I think it's okay if you want to +air on the side of having too much + + align:start position:0% +air on the side of having too much + + + align:start position:0% +air on the side of having too much +jargon that's okay cuz George is George + + align:start position:0% +jargon that's okay cuz George is George + + + align:start position:0% +jargon that's okay cuz George is George +and I are going to Workshop all the + + align:start position:0% +and I are going to Workshop all the + + + align:start position:0% +and I are going to Workshop all the +scripts with you tomorrow and we'll it's + + align:start position:0% +scripts with you tomorrow and we'll it's + + + align:start position:0% +scripts with you tomorrow and we'll it's +always a fine balance cuz you don't want + + align:start position:0% +always a fine balance cuz you don't want + + + align:start position:0% +always a fine balance cuz you don't want +to sit and Define everything right it's + + align:start position:0% +to sit and Define everything right it's + + + align:start position:0% +to sit and Define everything right it's +okay to challenge your audience a little + + align:start position:0% +okay to challenge your audience a little + + + align:start position:0% +okay to challenge your audience a little +bit you don't want to alienate them by + + align:start position:0% +bit you don't want to alienate them by + + + align:start position:0% +bit you don't want to alienate them by +talking in a language that they don't + + align:start position:0% +talking in a language that they don't + + + align:start position:0% +talking in a language that they don't +understand right so a a balance between + + align:start position:0% +understand right so a a balance between + + + align:start position:0% +understand right so a a balance between +that I think for tonight we want you + + align:start position:0% +that I think for tonight we want you + + + align:start position:0% +that I think for tonight we want you +just just like get something on paper + + align:start position:0% +just just like get something on paper + + + align:start position:0% +just just like get something on paper +and so don't get too stressed about that + + align:start position:0% +and so don't get too stressed about that + + + align:start position:0% +and so don't get too stressed about that +really focus on what the overall of + + align:start position:0% +really focus on what the overall of + + + align:start position:0% +really focus on what the overall of +story is going to be this is day two of + + align:start position:0% +story is going to be this is day two of + + + align:start position:0% +story is going to be this is day two of +the class and scripts take like a long + + align:start position:0% +the class and scripts take like a long + + + align:start position:0% +the class and scripts take like a long +time to write and refine and so we're + + align:start position:0% +time to write and refine and so we're + + + align:start position:0% +time to write and refine and so we're +not expecting Perfection or anything + + align:start position:0% +not expecting Perfection or anything + + + align:start position:0% +not expecting Perfection or anything +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +I concerned about like something like + + align:start position:0% +I concerned about like something like + + + align:start position:0% +I concerned about like something like +this there's no like visual elements + + align:start position:0% +this there's no like visual elements + + + align:start position:0% +this there's no like visual elements +like we SE so do you want me to show you + + align:start position:0% +like we SE so do you want me to show you + + + align:start position:0% +like we SE so do you want me to show you +um the computer or have you seen the + + align:start position:0% +um the computer or have you seen the + + + align:start position:0% +um the computer or have you seen the +yeah I I seen you're talking about the + + align:start position:0% +yeah I I seen you're talking about the + + + align:start position:0% +yeah I I seen you're talking about the +one where he puts like + + align:start position:0% + + + + align:start position:0% + +this I don't know any videos off the top + + align:start position:0% +this I don't know any videos off the top + + + align:start position:0% +this I don't know any videos off the top +of my head but what you might want to + + align:start position:0% +of my head but what you might want to + + + align:start position:0% +of my head but what you might want to +try doing is just looking on YouTube for + + align:start position:0% +try doing is just looking on YouTube for + + + align:start position:0% +try doing is just looking on YouTube for +maybe like ESU or vering videos that + + align:start position:0% +maybe like ESU or vering videos that + + + align:start position:0% +maybe like ESU or vering videos that +were about Computer Engineering and see + + align:start position:0% +were about Computer Engineering and see + + + align:start position:0% +were about Computer Engineering and see +what they use visually sometimes it's + + align:start position:0% +what they use visually sometimes it's + + + align:start position:0% +what they use visually sometimes it's +just their Persona like on screen vau + + align:start position:0% +just their Persona like on screen vau + + + align:start position:0% +just their Persona like on screen vau +does that a lot cuz he talks a lot about + + align:start position:0% +does that a lot cuz he talks a lot about + + + align:start position:0% +does that a lot cuz he talks a lot about +psychological Concepts that are sort of + + align:start position:0% +psychological Concepts that are sort of + + + align:start position:0% +psychological Concepts that are sort of +hard to visualize and it's just him on + + align:start position:0% +hard to visualize and it's just him on + + + align:start position:0% +hard to visualize and it's just him on +screen talking and he's just visually + + align:start position:0% +screen talking and he's just visually + + + align:start position:0% +screen talking and he's just visually +engaging that + + align:start position:0% +engaging that + + + align:start position:0% +engaging that +way I do agree this is going to be hard + + align:start position:0% +way I do agree this is going to be hard + + + align:start position:0% +way I do agree this is going to be hard +to + + align:start position:0% +to + + + align:start position:0% +to +and it's going to be hard to visualize + + align:start position:0% +and it's going to be hard to visualize + + + align:start position:0% +and it's going to be hard to visualize +um but maybe this is a place where + + align:start position:0% +um but maybe this is a place where + + + align:start position:0% +um but maybe this is a place where +animations could help and I always think + + align:start position:0% +animations could help and I always think + + + align:start position:0% +animations could help and I always think +animation should be used sparingly + + align:start position:0% +animation should be used sparingly + + + align:start position:0% +animation should be used sparingly +people have the tendency to rely on + + align:start position:0% +people have the tendency to rely on + + + align:start position:0% +people have the tendency to rely on +animation when because they think it's + + align:start position:0% +animation when because they think it's + + + align:start position:0% +animation when because they think it's +like cheaper or easier to make um and + + align:start position:0% +like cheaper or easier to make um and + + + align:start position:0% +like cheaper or easier to make um and +when Josh comes in maybe he and I you + + align:start position:0% +when Josh comes in maybe he and I you + + + align:start position:0% +when Josh comes in maybe he and I you +can talk a little bit more about how you + + align:start position:0% +can talk a little bit more about how you + + + align:start position:0% +can talk a little bit more about how you +would Implement that exactly um but + + align:start position:0% +would Implement that exactly um but + + + align:start position:0% +would Implement that exactly um but +having a person with just a an animated + + align:start position:0% +having a person with just a an animated + + + align:start position:0% +having a person with just a an animated +overlay like you saw at the beginning of + + align:start position:0% +overlay like you saw at the beginning of + + + align:start position:0% +overlay like you saw at the beginning of +that video um that can be a really + + align:start position:0% +that video um that can be a really + + + align:start position:0% +that video um that can be a really +simple simple solution way to engage + + align:start position:0% +simple simple solution way to engage + + + align:start position:0% +simple simple solution way to engage +people visually + + align:start position:0% + + + + align:start position:0% + +the idea is personally I think the idea + + align:start position:0% +the idea is personally I think the idea + + + align:start position:0% +the idea is personally I think the idea +is very + + align:start position:0% +is very + + + align:start position:0% +is very +fascinating the the notion + + align:start position:0% +fascinating the the notion + + + align:start position:0% +fascinating the the notion +that we live in a world where we think + + align:start position:0% +that we live in a world where we think + + + align:start position:0% +that we live in a world where we think +we've achieved so much technological + + align:start position:0% +we've achieved so much technological + + + align:start position:0% +we've achieved so much technological +prowess but a problem that seems so + + align:start position:0% +prowess but a problem that seems so + + + align:start position:0% +prowess but a problem that seems so +basic like that + + align:start position:0% +basic like that + + + align:start position:0% +basic like that +understanding how to solve opiz four + + align:start position:0% +understanding how to solve opiz four + + + align:start position:0% +understanding how to solve opiz four +five six things is actually incredibly + + align:start position:0% +five six things is actually incredibly + + + align:start position:0% +five six things is actually incredibly +challenging and this is why like this is + + align:start position:0% +challenging and this is why like this is + + + align:start position:0% +challenging and this is why like this is +the thing that we can conceptualize our + + align:start position:0% +the thing that we can conceptualize our + + + align:start position:0% +the thing that we can conceptualize our +minds as humans but when you try to get + + align:start position:0% +minds as humans but when you try to get + + + align:start position:0% +minds as humans but when you try to get +a computer to do it like it's actually + + align:start position:0% +a computer to do it like it's actually + + + align:start position:0% +a computer to do it like it's actually +impossible it's + + align:start position:0% +impossible it's + + + align:start position:0% +impossible it's +impossible I went to this talk a while + + align:start position:0% +impossible I went to this talk a while + + + align:start position:0% +impossible I went to this talk a while +back um given by one of the guys who + + align:start position:0% +back um given by one of the guys who + + + align:start position:0% +back um given by one of the guys who +runs the humanoid robots group at MIT + + align:start position:0% +runs the humanoid robots group at MIT + + + align:start position:0% +runs the humanoid robots group at MIT +and he was saying um how it was so hard + + align:start position:0% +and he was saying um how it was so hard + + + align:start position:0% +and he was saying um how it was so hard +to program a humanoid a bipedal robot to + + align:start position:0% +to program a humanoid a bipedal robot to + + + align:start position:0% +to program a humanoid a bipedal robot to +walk like a human being yeah and it's + + align:start position:0% +walk like a human being yeah and it's + + + align:start position:0% +walk like a human being yeah and it's +because um you know we walk every day + + align:start position:0% +because um you know we walk every day + + + align:start position:0% +because um you know we walk every day +right and like we don't think anything + + align:start position:0% +right and like we don't think anything + + + align:start position:0% +right and like we don't think anything +of it but to model the movement of your + + align:start position:0% +of it but to model the movement of your + + + align:start position:0% +of it but to model the movement of your +knee bending and putting your foot down + + align:start position:0% +knee bending and putting your foot down + + + align:start position:0% +knee bending and putting your foot down +it's actually impossible to + + align:start position:0% +it's actually impossible to + + + align:start position:0% +it's actually impossible to +mathematically model that with the + + align:start position:0% +mathematically model that with the + + + align:start position:0% +mathematically model that with the +Precision of reality um and I don't + + align:start position:0% +Precision of reality um and I don't + + + align:start position:0% +Precision of reality um and I don't +remember the exact math about it but I + + align:start position:0% +remember the exact math about it but I + + + align:start position:0% +remember the exact math about it but I +remember hearing this notion that like + + align:start position:0% +remember hearing this notion that like + + + align:start position:0% +remember hearing this notion that like +there is no way in math for us to model + + align:start position:0% +there is no way in math for us to model + + + align:start position:0% +there is no way in math for us to model +something that we do in reality every + + align:start position:0% +something that we do in reality every + + + align:start position:0% +something that we do in reality every +day right so even if we create like the + + align:start position:0% +day right so even if we create like the + + + align:start position:0% +day right so even if we create like the +world's biggest super computer robot is + + align:start position:0% +world's biggest super computer robot is + + + align:start position:0% +world's biggest super computer robot is +never going to come close to what the + + align:start position:0% +never going to come close to what the + + + align:start position:0% +never going to come close to what the +what the human body can achieve like in + + align:start position:0% +what the human body can achieve like in + + + align:start position:0% +what the human body can achieve like in +their sleep you know and I thought that + + align:start position:0% +their sleep you know and I thought that + + + align:start position:0% +their sleep you know and I thought that +was such an + + align:start position:0% +was such an + + + align:start position:0% +was such an +interesting um concept that humans are + + align:start position:0% +interesting um concept that humans are + + + align:start position:0% +interesting um concept that humans are +still like so complex even even with all + + align:start position:0% +still like so complex even even with all + + + align:start position:0% +still like so complex even even with all +the Evan we've made in + + align:start position:0% +the Evan we've made in + + + align:start position:0% +the Evan we've made in +robotics um and that was a theme that we + + align:start position:0% +robotics um and that was a theme that we + + + align:start position:0% +robotics um and that was a theme that we +tried to hit in one of our episodes + + align:start position:0% +tried to hit in one of our episodes + + + align:start position:0% +tried to hit in one of our episodes +actually um does that help a little bit + + align:start position:0% +actually um does that help a little bit + + + align:start position:0% +actually um does that help a little bit +I don't know maybe you just have more + + align:start position:0% +I don't know maybe you just have more + + + align:start position:0% +I don't know maybe you just have more +questions + + align:start position:0% +questions + + + align:start position:0% +questions +uh so the at the end of the whole each + + align:start position:0% + + + + align:start position:0% + +come it'll be great wait can I just + + align:start position:0% +come it'll be great wait can I just + + + align:start position:0% +come it'll be great wait can I just +pinch my sure yeah so I + + align:start position:0% +pinch my sure yeah so I + + + align:start position:0% +pinch my sure yeah so I +mean I have one on the on algorithms and + + align:start position:0% +mean I have one on the on algorithms and + + + align:start position:0% +mean I have one on the on algorithms and +like the simplest algorithm I can think + + align:start position:0% +like the simplest algorithm I can think + + + align:start position:0% +like the simplest algorithm I can think +of is this on search so I was just + + align:start position:0% +of is this on search so I was just + + + align:start position:0% +of is this on search so I was just +thinking of like w w or or what do you + + align:start position:0% +thinking of like w w or or what do you + + + align:start position:0% +thinking of like w w or or what do you +call it um I mean maybe that's what + + align:start position:0% +call it um I mean maybe that's what + + + align:start position:0% +call it um I mean maybe that's what +you're doing but + + align:start position:0% +you're doing but + + + align:start position:0% +you're doing but +where's + + align:start position:0% +where's + + + align:start position:0% +where's +where it probably be like just some guy + + align:start position:0% +where it probably be like just some guy + + + align:start position:0% +where it probably be like just some guy +just hiding in the building they'll be + + align:start position:0% +just hiding in the building they'll be + + + align:start position:0% +just hiding in the building they'll be +like what's the best way to + + align:start position:0% +like what's the best way to + + + align:start position:0% +like what's the best way to +find yeah then we'll just be running + + align:start position:0% +find yeah then we'll just be running + + + align:start position:0% +find yeah then we'll just be running +around yeah yeah like so first Way open + + align:start position:0% +around yeah yeah like so first Way open + + + align:start position:0% +around yeah yeah like so first Way open +every door on yours to you and you just + + align:start position:0% +every door on yours to you and you just + + + align:start position:0% +every door on yours to you and you just +keep going every level then there's + + align:start position:0% +keep going every level then there's + + + align:start position:0% +keep going every level then there's +another way where you keep going half + + align:start position:0% +another way where you keep going half + + + align:start position:0% +another way where you keep going half +yeah but then I start to realize that + + align:start position:0% +yeah but then I start to realize that + + + align:start position:0% +yeah but then I start to realize that +the energy might break down somewhere + + align:start position:0% +the energy might break down somewhere + + + align:start position:0% +the energy might break down somewhere +halfway cuz + + align:start position:0% +halfway cuz + + + align:start position:0% +halfway cuz +what's the + + align:start position:0% + + + + align:start position:0% + +umbrella the algorithm on the teach was + + align:start position:0% +umbrella the algorithm on the teach was + + + align:start position:0% +umbrella the algorithm on the teach was +a binary search which is like you cut + + align:start position:0% +a binary search which is like you cut + + + align:start position:0% +a binary search which is like you cut +half and then you see whether it's w on + + align:start position:0% +half and then you see whether it's w on + + + align:start position:0% +half and then you see whether it's w on +the right side or left side and then you + + align:start position:0% +the right side or left side and then you + + + align:start position:0% +the right side or left side and then you +cut half again in right side left side + + align:start position:0% +cut half again in right side left side + + + align:start position:0% +cut half again in right side left side +yeah I think that's very interesting + + align:start position:0% +yeah I think that's very interesting + + + align:start position:0% +yeah I think that's very interesting +um what is what is the final application + + align:start position:0% +um what is what is the final application + + + align:start position:0% +um what is what is the final application +of search + + align:start position:0% +of search + + + align:start position:0% +of search +algorithms Google like Google biology + + align:start position:0% +algorithms Google like Google biology + + + align:start position:0% +algorithms Google like Google biology +material sence um I think as long as you + + align:start position:0% +material sence um I think as long as you + + + align:start position:0% +material sence um I think as long as you +relate it back to the big picture of + + align:start position:0% +relate it back to the big picture of + + + align:start position:0% +relate it back to the big picture of +like why that's such an awesome thing + + align:start position:0% +like why that's such an awesome thing + + + align:start position:0% +like why that's such an awesome thing +cuz what you don't want happening is + + align:start position:0% +cuz what you don't want happening is + + + align:start position:0% +cuz what you don't want happening is +people to think like oh okay cool I get + + align:start position:0% +people to think like oh okay cool I get + + + align:start position:0% +people to think like oh okay cool I get +that it's a binary Sur but things Happ + + align:start position:0% +that it's a binary Sur but things Happ + + + align:start position:0% +that it's a binary Sur but things Happ +so what like why should I care right you + + align:start position:0% +so what like why should I care right you + + + align:start position:0% +so what like why should I care right you +should care because it's like what + + align:start position:0% +should care because it's like what + + + align:start position:0% +should care because it's like what +drives the most used website in the + + align:start position:0% +drives the most used website in the + + + align:start position:0% +drives the most used website in the +world and I think relating it back to + + align:start position:0% +world and I think relating it back to + + + align:start position:0% +world and I think relating it back to +that like that's what we tried to do + + align:start position:0% +that like that's what we tried to do + + + align:start position:0% +that like that's what we tried to do +with the switches video is like okay I I + + align:start position:0% +with the switches video is like okay I I + + + align:start position:0% +with the switches video is like okay I I +get that the billiard ball hits the + + align:start position:0% +get that the billiard ball hits the + + + align:start position:0% +get that the billiard ball hits the +switch on or off but we tied it back at + + align:start position:0% +switch on or off but we tied it back at + + + align:start position:0% +switch on or off but we tied it back at +the very end to say like + + align:start position:0% +the very end to say like + + + align:start position:0% +the very end to say like +this toy has 20 switches but most + + align:start position:0% +this toy has 20 switches but most + + + align:start position:0% +this toy has 20 switches but most +computers have like billions of switches + + align:start position:0% +computers have like billions of switches + + + align:start position:0% +computers have like billions of switches +and that's what makes a semiconductor + + align:start position:0% +and that's what makes a semiconductor + + + align:start position:0% +and that's what makes a semiconductor +and that's what makes every modern + + align:start position:0% +and that's what makes every modern + + + align:start position:0% +and that's what makes every modern +electronic possible as as long as you + + align:start position:0% +electronic possible as as long as you + + + align:start position:0% +electronic possible as as long as you +relate it back to the big picture to the + + align:start position:0% +relate it back to the big picture to the + + + align:start position:0% +relate it back to the big picture to the +thing that people relate to the thing + + align:start position:0% +thing that people relate to the thing + + + align:start position:0% +thing that people relate to the thing +that people use every day I think that + + align:start position:0% +that people use every day I think that + + + align:start position:0% +that people use every day I think that +can be powerful so that's + + align:start position:0% + + + + align:start position:0% + +actually so I mean I also I like this + + align:start position:0% +actually so I mean I also I like this + + + align:start position:0% +actually so I mean I also I like this +path and GPS thing like how exactly does + + align:start position:0% +path and GPS thing like how exactly does + + + align:start position:0% +path and GPS thing like how exactly does +a GPS work + + align:start position:0% +a GPS work + + + align:start position:0% +a GPS work +um how do you find your way you know + + align:start position:0% +um how do you find your way you know + + + align:start position:0% +um how do you find your way you know +knowing what knowing your location in + + align:start position:0% +knowing what knowing your location in + + + align:start position:0% +knowing what knowing your location in +GPS no but I was actually like mapping a + + align:start position:0% +GPS no but I was actually like mapping a + + + align:start position:0% +GPS no but I was actually like mapping a +path there's + + align:start position:0% +path there's + + + align:start position:0% +path there's +different yeah GPS like how does Google + + align:start position:0% +different yeah GPS like how does Google + + + align:start position:0% +different yeah GPS like how does Google +Maps know + + align:start position:0% +Maps know + + + align:start position:0% +Maps know +oh we are + + align:start position:0% +oh we are + + + align:start position:0% +oh we are +just oh yeah + + align:start position:0% +just oh yeah + + + align:start position:0% +just oh yeah +sorry I don't have too much to say + + align:start position:0% +sorry I don't have too much to say + + + align:start position:0% +sorry I don't have too much to say +except + + align:start position:0% +except + + + align:start position:0% +except +for daily assignment so another daily + + align:start position:0% +for daily assignment so another daily + + + align:start position:0% +for daily assignment so another daily +vog thank you all for posting your stuff + + align:start position:0% +vog thank you all for posting your stuff + + + align:start position:0% +vog thank you all for posting your stuff +on Tumblr yesterday keep in mind that + + align:start position:0% +on Tumblr yesterday keep in mind that + + + align:start position:0% +on Tumblr yesterday keep in mind that +you don't have to do a text post like I + + align:start position:0% +you don't have to do a text post like I + + + align:start position:0% +you don't have to do a text post like I +did I just did that as an example but if + + align:start position:0% +did I just did that as an example but if + + + align:start position:0% +did I just did that as an example but if +you guys want to do a video blog if you + + align:start position:0% +you guys want to do a video blog if you + + + align:start position:0% +you guys want to do a video blog if you +want to just Vlog on your laptop webcam + + align:start position:0% +want to just Vlog on your laptop webcam + + + align:start position:0% +want to just Vlog on your laptop webcam +that's totally fine uh if you end up + + align:start position:0% +that's totally fine uh if you end up + + + align:start position:0% +that's totally fine uh if you end up +taking pictures during any of the + + align:start position:0% +taking pictures during any of the + + + align:start position:0% +taking pictures during any of the +lectures or taking videos during the + + align:start position:0% +lectures or taking videos during the + + + align:start position:0% +lectures or taking videos during the +lectures you're free to post those too + + align:start position:0% +lectures you're free to post those too + + + align:start position:0% +lectures you're free to post those too +um and just post them with the hash day2 + + align:start position:0% +um and just post them with the hash day2 + + + align:start position:0% +um and just post them with the hash day2 +and your Kos ID all this stuff is on + + align:start position:0% +and your Kos ID all this stuff is on + + + align:start position:0% +and your Kos ID all this stuff is on +Tumbler the day two weeks thing and then + + align:start position:0% +Tumbler the day two weeks thing and then + + + align:start position:0% +Tumbler the day two weeks thing and then +a a quick 200 to 300 rough script based + + align:start position:0% +a a quick 200 to 300 rough script based + + + align:start position:0% +a a quick 200 to 300 rough script based +on some of the stuff we've talked about + + align:start position:0% +on some of the stuff we've talked about + + + align:start position:0% +on some of the stuff we've talked about +now um don't worry about being too + + align:start position:0% +now um don't worry about being too + + + align:start position:0% +now um don't worry about being too +jargoning in this uh this is really + + align:start position:0% +jargoning in this uh this is really + + + align:start position:0% +jargoning in this uh this is really +about honing the overarching story we're + + align:start position:0% +about honing the overarching story we're + + + align:start position:0% +about honing the overarching story we're +going to work out the details of what's + + align:start position:0% +going to work out the details of what's + + + align:start position:0% +going to work out the details of what's +the best wording to use we're going to + + align:start position:0% +the best wording to use we're going to + + + align:start position:0% +the best wording to use we're going to +work out some of the minutia of it + + align:start position:0% +work out some of the minutia of it + + + align:start position:0% +work out some of the minutia of it +tomorrow during our scripting workshop + + align:start position:0% +tomorrow during our scripting workshop + + + align:start position:0% +tomorrow during our scripting workshop +for tonight think about what's what's + + align:start position:0% +for tonight think about what's what's + + + align:start position:0% +for tonight think about what's what's +the point of the video and what the + + align:start position:0% +the point of the video and what the + + + align:start position:0% +the point of the video and what the +overarching story of the video is those + + align:start position:0% +overarching story of the video is those + + + align:start position:0% +overarching story of the video is those +are really the things you want to think + + align:start position:0% +are really the things you want to think + + + align:start position:0% +are really the things you want to think +about tonight um if you get so stuck and + + align:start position:0% +about tonight um if you get so stuck and + + + align:start position:0% +about tonight um if you get so stuck and +you just can't think of something to + + align:start position:0% +you just can't think of something to + + + align:start position:0% +you just can't think of something to +write write down facts like I was + + align:start position:0% +write write down facts like I was + + + align:start position:0% +write write down facts like I was +showing earlier just come to class with + + align:start position:0% +showing earlier just come to class with + + + align:start position:0% +showing earlier just come to class with +something that we can work with tomorrow + + align:start position:0% +something that we can work with tomorrow + + + align:start position:0% +something that we can work with tomorrow +because tomorrow is going to be a really + + align:start position:0% +because tomorrow is going to be a really + + + align:start position:0% +because tomorrow is going to be a really +informal day George and I are just going + + align:start position:0% +informal day George and I are just going + + + align:start position:0% +informal day George and I are just going +to Workshop in the table we'll read some + + align:start position:0% +to Workshop in the table we'll read some + + + align:start position:0% +to Workshop in the table we'll read some +of the stuff that we've written um and + + align:start position:0% +of the stuff that we've written um and + + + align:start position:0% +of the stuff that we've written um and +figure out how to implement the + + align:start position:0% +figure out how to implement the + + + align:start position:0% +figure out how to implement the +theoretical things that we've been + + align:start position:0% +theoretical things that we've been + + + align:start position:0% +theoretical things that we've been +talking about the last two days in a + + align:start position:0% +talking about the last two days in a + + + align:start position:0% +talking about the last two days in a +more practical sense um so does anyone + + align:start position:0% +more practical sense um so does anyone + + + align:start position:0% +more practical sense um so does anyone +have any questions about those + + align:start position:0% +have any questions about those + + + align:start position:0% +have any questions about those +assignments you want to bring back to + + align:start position:0% +assignments you want to bring back to + + + align:start position:0% +assignments you want to bring back to +canas tomorrow um no tomorrow will just + + align:start position:0% +canas tomorrow um no tomorrow will just + + + align:start position:0% +canas tomorrow um no tomorrow will just +be workshopping we will need them back + + align:start position:0% +be workshopping we will need them back + + + align:start position:0% +be workshopping we will need them back +at least on Friday I'll send you guys an + + align:start position:0% +at least on Friday I'll send you guys an + + + align:start position:0% +at least on Friday I'll send you guys an +email the night before the day we leave + + align:start position:0% +email the night before the day we leave + + + align:start position:0% +email the night before the day we leave +them back class when I just as a as a + + align:start position:0% +them back class when I just as a as a + + + align:start position:0% +them back class when I just as a as a +something to think about when I walked + + align:start position:0% +something to think about when I walked + + + align:start position:0% +something to think about when I walked +around and and talked to some of you + + align:start position:0% +around and and talked to some of you + + + align:start position:0% +around and and talked to some of you +guys more deeply I feel like a lot of + + align:start position:0% +guys more deeply I feel like a lot of + + + align:start position:0% +guys more deeply I feel like a lot of +You Are ort of struggling with this same + + align:start position:0% +You Are ort of struggling with this same + + + align:start position:0% +You Are ort of struggling with this same +concept of broad versus detailed + + align:start position:0% +concept of broad versus detailed + + + align:start position:0% +concept of broad versus detailed +and my my two cents on it is + + align:start position:0% +and my my two cents on it is + + + align:start position:0% +and my my two cents on it is +that by asking a broad question but + + align:start position:0% +that by asking a broad question but + + + align:start position:0% +that by asking a broad question but +going ver narrowly in with one example + + align:start position:0% +going ver narrowly in with one example + + + align:start position:0% +going ver narrowly in with one example +you actually end up being able to bring + + align:start position:0% +you actually end up being able to bring + + + align:start position:0% +you actually end up being able to bring +people back up to that broader framework + + align:start position:0% +people back up to that broader framework + + + align:start position:0% +people back up to that broader framework +so if you pick something like we talked + + align:start position:0% +so if you pick something like we talked + + + align:start position:0% +so if you pick something like we talked +about food composition and we started + + align:start position:0% +about food composition and we started + + + align:start position:0% +about food composition and we started +exploring further maybe talking about + + align:start position:0% +exploring further maybe talking about + + + align:start position:0% +exploring further maybe talking about +why a piece of broccoli rots and when is + + align:start position:0% +why a piece of broccoli rots and when is + + + align:start position:0% +why a piece of broccoli rots and when is +it too rotten for me to eat that I get + + align:start position:0% +it too rotten for me to eat that I get + + + align:start position:0% +it too rotten for me to eat that I get +sick is actually the perfect Focus for + + align:start position:0% +sick is actually the perfect Focus for + + + align:start position:0% +sick is actually the perfect Focus for +him to ask all these other questions + + align:start position:0% +him to ask all these other questions + + + align:start position:0% +him to ask all these other questions +about food composition and that by + + align:start position:0% +about food composition and that by + + + align:start position:0% +about food composition and that by +focusing really narrowly on that + + align:start position:0% +focusing really narrowly on that + + + align:start position:0% +focusing really narrowly on that +broccoli we actually get to ask a lot + + align:start position:0% +broccoli we actually get to ask a lot + + + align:start position:0% +broccoli we actually get to ask a lot +more questions right like with ship + + align:start position:0% +more questions right like with ship + + + align:start position:0% +more questions right like with ship +building why does something really sink + + align:start position:0% +building why does something really sink + + + align:start position:0% +building why does something really sink +or float but that question diving really + + align:start position:0% +or float but that question diving really + + + align:start position:0% +or float but that question diving really +narrowly into one scenario of one ship + + align:start position:0% +narrowly into one scenario of one ship + + + align:start position:0% +narrowly into one scenario of one ship +sinking and why does it do this it + + align:start position:0% +sinking and why does it do this it + + + align:start position:0% +sinking and why does it do this it +allows us to be able to ask some broader + + align:start position:0% +allows us to be able to ask some broader + + + align:start position:0% +allows us to be able to ask some broader +questions questions why the braces the + + align:start position:0% +questions questions why the braces the + + + align:start position:0% +questions questions why the braces the +opposite right I want to talk about + + align:start position:0% +opposite right I want to talk about + + + align:start position:0% +opposite right I want to talk about +braces and what they do to your teeth + + align:start position:0% +braces and what they do to your teeth + + + align:start position:0% +braces and what they do to your teeth +but all right let's think about if + + align:start position:0% +but all right let's think about if + + + align:start position:0% +but all right let's think about if +that's a specific example what's the + + align:start position:0% +that's a specific example what's the + + + align:start position:0% +that's a specific example what's the +question that we're trying to think + + align:start position:0% +question that we're trying to think + + + align:start position:0% +question that we're trying to think +through and I feel like all of you are + + align:start position:0% +through and I feel like all of you are + + + align:start position:0% +through and I feel like all of you are +kind of in that place right now where + + align:start position:0% +kind of in that place right now where + + + align:start position:0% +kind of in that place right now where +you're trying to figure out what + + align:start position:0% +you're trying to figure out what + + + align:start position:0% +you're trying to figure out what +specific story do I tell in order to get + + align:start position:0% +specific story do I tell in order to get + + + align:start position:0% +specific story do I tell in order to get +at these bigger bigger Concepts the + + align:start position:0% +at these bigger bigger Concepts the + + + align:start position:0% +at these bigger bigger Concepts the +narrower you are in that that microcosm + + align:start position:0% +narrower you are in that that microcosm + + + align:start position:0% +narrower you are in that that microcosm +the easier it is to extrapolate out + + align:start position:0% +the easier it is to extrapolate out + + + align:start position:0% +the easier it is to extrapolate out +because it lets you really dive deeply + + align:start position:0% +because it lets you really dive deeply + + + align:start position:0% +because it lets you really dive deeply +into that topic so if you have a really + + align:start position:0% +into that topic so if you have a really + + + align:start position:0% +into that topic so if you have a really +really broad topic still see if you can + + align:start position:0% +really broad topic still see if you can + + + align:start position:0% +really broad topic still see if you can +get it really narrow and then from that + + align:start position:0% +get it really narrow and then from that + + + align:start position:0% +get it really narrow and then from that +it allows you to get broad again if that + + align:start position:0% +it allows you to get broad again if that + + + align:start position:0% +it allows you to get broad again if that +makes sense and that's why I personally + + align:start position:0% +makes sense and that's why I personally + + + align:start position:0% +makes sense and that's why I personally +like going with the whole just trying to + + align:start position:0% +like going with the whole just trying to + + + align:start position:0% +like going with the whole just trying to +list out as many facts as I can with the + + align:start position:0% +list out as many facts as I can with the + + + align:start position:0% +list out as many facts as I can with the +snot thing cuz it was just sort of + + align:start position:0% +snot thing cuz it was just sort of + + + align:start position:0% +snot thing cuz it was just sort of +notnot as awesome okay like you know why + + align:start position:0% +notnot as awesome okay like you know why + + + align:start position:0% +notnot as awesome okay like you know why +is it awesome what what does that even + + align:start position:0% +is it awesome what what does that even + + + align:start position:0% +is it awesome what what does that even +mean and so I'm listing out all these + + align:start position:0% +mean and so I'm listing out all these + + + align:start position:0% +mean and so I'm listing out all these +specific things that people study about + + align:start position:0% +specific things that people study about + + + align:start position:0% +specific things that people study about +it and that helped me delve into the + + align:start position:0% +it and that helped me delve into the + + + align:start position:0% +it and that helped me delve into the +tangible + + align:start position:0% +tangible + + + align:start position:0% +tangible +um examples that I gave that allowed me + + align:start position:0% +um examples that I gave that allowed me + + + align:start position:0% +um examples that I gave that allowed me +at the end to go back out to this story + + align:start position:0% +at the end to go back out to this story + + + align:start position:0% +at the end to go back out to this story +of this material that protects you every + + align:start position:0% +of this material that protects you every + + + align:start position:0% +of this material that protects you every +day and is you know amazing and awesome + + align:start position:0% +day and is you know amazing and awesome + + + align:start position:0% +day and is you know amazing and awesome +and I know we're just about we're + + align:start position:0% +and I know we're just about we're + + + align:start position:0% +and I know we're just about we're +actually overtime so I apologize but I + + align:start position:0% +actually overtime so I apologize but I + + + align:start position:0% +actually overtime so I apologize but I +realize that some of you may not know + + align:start position:0% +realize that some of you may not know + + + align:start position:0% +realize that some of you may not know +how to implement Elizabeth's task of + + align:start position:0% +how to implement Elizabeth's task of + + + align:start position:0% +how to implement Elizabeth's task of +asking you to actually write your script + + align:start position:0% +asking you to actually write your script + + + align:start position:0% +asking you to actually write your script +and that that may be an overwhelming + + align:start position:0% +and that that may be an overwhelming + + + align:start position:0% +and that that may be an overwhelming +task is that feeling like that right now + + align:start position:0% +task is that feeling like that right now + + + align:start position:0% +task is that feeling like that right now +like sitting down and actually putting + + align:start position:0% +like sitting down and actually putting + + + align:start position:0% +like sitting down and actually putting +something on paper you don't know where + + align:start position:0% +something on paper you don't know where + + + align:start position:0% +something on paper you don't know where +to start or do you feel like you know + + align:start position:0% +to start or do you feel like you know + + + align:start position:0% +to start or do you feel like you know +you know how to at least dump something + + align:start position:0% +you know how to at least dump something + + + align:start position:0% +you know how to at least dump something +down sort of like you know Paul col says + + align:start position:0% +down sort of like you know Paul col says + + + align:start position:0% +down sort of like you know Paul col says +this picture of something in here like + + align:start position:0% +this picture of something in here like + + + align:start position:0% +this picture of something in here like +just jot it down doesn't don't worry + + align:start position:0% +just jot it down doesn't don't worry + + + align:start position:0% +just jot it down doesn't don't worry +about format don't worry about any of + + align:start position:0% +about format don't worry about any of + + + align:start position:0% +about format don't worry about any of +that we're going to go over all the + + align:start position:0% +that we're going to go over all the + + + align:start position:0% +that we're going to go over all the +details + + align:start position:0% +details + + + align:start position:0% +details +tomorrow yeah just dump so so if when + + align:start position:0% +tomorrow yeah just dump so so if when + + + align:start position:0% +tomorrow yeah just dump so so if when +she says script that word may be + + align:start position:0% +she says script that word may be + + + align:start position:0% +she says script that word may be +intimidating right now because a script + + align:start position:0% +intimidating right now because a script + + + align:start position:0% +intimidating right now because a script +can look certain ways in different + + align:start position:0% +can look certain ways in different + + + align:start position:0% +can look certain ways in different +genres like a film script looks very + + align:start position:0% +genres like a film script looks very + + + align:start position:0% +genres like a film script looks very +different from you know a theater script + + align:start position:0% +different from you know a theater script + + + align:start position:0% +different from you know a theater script +versus this kind of script + + align:start position:0% +versus this kind of script + + + align:start position:0% +versus this kind of script +don't worry about anything other than + + align:start position:0% +don't worry about anything other than + + + align:start position:0% +don't worry about anything other than +getting some ideas on paper and we'll + + align:start position:0% +getting some ideas on paper and we'll + + + align:start position:0% +getting some ideas on paper and we'll +deal with all the other stuff later if + + align:start position:0% +deal with all the other stuff later if + + + align:start position:0% +deal with all the other stuff later if +that makes + + align:start position:0% + + + + align:start position:0% + +sense and I'll Stick Around afterwards + + align:start position:0% +sense and I'll Stick Around afterwards + + + align:start position:0% +sense and I'll Stick Around afterwards +if anyone wants to talk specifically + + align:start position:0% +if anyone wants to talk specifically + + + align:start position:0% +if anyone wants to talk specifically +yeah and just upload all that stuff to + + align:start position:0% +yeah and just upload all that stuff to + + + align:start position:0% +yeah and just upload all that stuff to +Tumblr and we're both available and + + align:start position:0% +Tumblr and we're both available and + + + align:start position:0% +Tumblr and we're both available and +we're all available via email so if any + + align:start position:0% +we're all available via email so if any + + + align:start position:0% +we're all available via email so if any +of you are struggling tonight and you + + align:start position:0% +of you are struggling tonight and you + + + align:start position:0% +of you are struggling tonight and you +need to bounce an idea off of one of us + + align:start position:0% +need to bounce an idea off of one of us + + + align:start position:0% +need to bounce an idea off of one of us +don't hesitate to to do that I do not + + align:start position:0% +don't hesitate to to do that I do not + + + align:start position:0% +don't hesitate to to do that I do not +check email usually until after 8:00 + + align:start position:0% +check email usually until after 8:00 + + + align:start position:0% +check email usually until after 8:00 +p.m. when my son goes to bed but I will + + align:start position:0% +p.m. when my son goes to bed but I will + + + align:start position:0% +p.m. when my son goes to bed but I will +respond so if you if you have a question + + align:start position:0% +respond so if you if you have a question + + + align:start position:0% +respond so if you if you have a question +or anything don't hesitate to bounce + + align:start position:0% +or anything don't hesitate to bounce + + + align:start position:0% +or anything don't hesitate to bounce +ideas off and I I do really get back to + + align:start position:0% +ideas off and I I do really get back to + + + align:start position:0% +ideas off and I I do really get back to +you guys and as as to all of + + align:start position:0% +you guys and as as to all of + + + align:start position:0% +you guys and as as to all of +us okay so that's all for today you guys + + align:start position:0% +us okay so that's all for today you guys + + + align:start position:0% +us okay so that's all for today you guys +can pack up and leave but really just + + align:start position:0% +can pack up and leave but really just + + + align:start position:0% +can pack up and leave but really just +get ideas down more than anything we + + align:start position:0% +get ideas down more than anything we + + + align:start position:0% +get ideas down more than anything we +will help you with everything else + + align:start position:0% +will help you with everything else + + + align:start position:0% +will help you with everything else +tomorrow even if drawing is the way that + + align:start position:0% +tomorrow even if drawing is the way that + + + align:start position:0% +tomorrow even if drawing is the way that +helps you just get something down but do + + align:start position:0% +helps you just get something down but do + + + align:start position:0% +helps you just get something down but do +get words down we we need to have like + + align:start position:0% +get words down we we need to have like + + + align:start position:0% +get words down we we need to have like +like some words to work with is the + + align:start position:0% +like some words to work with is the + + + align:start position:0% +like some words to work with is the +script supposed to go on Lev yeah + + align:start position:0% +script supposed to go on Lev yeah + + + align:start position:0% +script supposed to go on Lev yeah +yeah good work guys all right \ No newline at end of file diff --git a/WdQUiCPvcvw.txt b/WdQUiCPvcvw.txt new file mode 100644 index 0000000000000000000000000000000000000000..6ceeea3cf6feb6cbb89bc44285c1e47c75baad86 --- /dev/null +++ b/WdQUiCPvcvw.txt @@ -0,0 +1,555 @@ +align:start position:0% + +you know so why this hashtag of course + + align:start position:0% +you know so why this hashtag of course + + + align:start position:0% +you know so why this hashtag of course +the hashtag stay work but I love it + + align:start position:0% +the hashtag stay work but I love it + + + align:start position:0% +the hashtag stay work but I love it +because in a way it's um it's gonna + + align:start position:0% +because in a way it's um it's gonna + + + align:start position:0% +because in a way it's um it's gonna +believe them phrases that take a very + + align:start position:0% +believe them phrases that take a very + + + align:start position:0% +believe them phrases that take a very +complex concept and that makes that + + align:start position:0% +complex concept and that makes that + + + align:start position:0% +complex concept and that makes that +accessible to a large public because + + align:start position:0% +accessible to a large public because + + + align:start position:0% +accessible to a large public because +they work is a way to talk about + + align:start position:0% +they work is a way to talk about + + + align:start position:0% +they work is a way to talk about +critical consciousness and what you what + + align:start position:0% +critical consciousness and what you what + + + align:start position:0% +critical consciousness and what you what +we've seen say in the past elections is + + align:start position:0% +we've seen say in the past elections is + + + align:start position:0% +we've seen say in the past elections is +this increase of current code fitness + + align:start position:0% +this increase of current code fitness + + + align:start position:0% +this increase of current code fitness +and one thing which have been trying to + + align:start position:0% +and one thing which have been trying to + + + align:start position:0% +and one thing which have been trying to +share with the student is that this this + + align:start position:0% +share with the student is that this this + + + align:start position:0% +share with the student is that this this +concept of fitness isn't at all a new + + align:start position:0% +concept of fitness isn't at all a new + + + align:start position:0% +concept of fitness isn't at all a new +phenomenon so in fact if you look at the + + align:start position:0% +phenomenon so in fact if you look at the + + + align:start position:0% +phenomenon so in fact if you look at the +way history is taught in the US if you + + align:start position:0% +way history is taught in the US if you + + + align:start position:0% +way history is taught in the US if you +look at see Howard Zinn's book about + + align:start position:0% +look at see Howard Zinn's book about + + + align:start position:0% +look at see Howard Zinn's book about +history it tells us how our history + + align:start position:0% +history it tells us how our history + + + align:start position:0% +history it tells us how our history +books are filled with fake news so the + + align:start position:0% +books are filled with fake news so the + + + align:start position:0% +books are filled with fake news so the +point is that it's not just fake news + + align:start position:0% +point is that it's not just fake news + + + align:start position:0% +point is that it's not just fake news +that's fake and and what the students + + align:start position:0% +that's fake and and what the students + + + align:start position:0% +that's fake and and what the students +get to see through for example the + + align:start position:0% +get to see through for example the + + + align:start position:0% +get to see through for example the +Haitian Revolution is that in the + + align:start position:0% +Haitian Revolution is that in the + + + align:start position:0% +Haitian Revolution is that in the +textbooks most of them actually almost + + align:start position:0% +textbooks most of them actually almost + + + align:start position:0% +textbooks most of them actually almost +all of them maybe except for one or two + + align:start position:0% +all of them maybe except for one or two + + + align:start position:0% +all of them maybe except for one or two +they got to learn lots of details about + + align:start position:0% +they got to learn lots of details about + + + align:start position:0% +they got to learn lots of details about +the French Revolution and then the + + align:start position:0% +the French Revolution and then the + + + align:start position:0% +the French Revolution and then the +American Revolution you don't know all + + align:start position:0% +American Revolution you don't know all + + + align:start position:0% +American Revolution you don't know all +these about that but almost none of them + + align:start position:0% +these about that but almost none of them + + + align:start position:0% +these about that but almost none of them +knew about Haiti but if you think of + + align:start position:0% +knew about Haiti but if you think of + + + align:start position:0% +knew about Haiti but if you think of +what evolution means the evolution has + + align:start position:0% +what evolution means the evolution has + + + align:start position:0% +what evolution means the evolution has +been has had much more impact when it + + align:start position:0% +been has had much more impact when it + + + align:start position:0% +been has had much more impact when it +comes to human rights civil liberties + + align:start position:0% +comes to human rights civil liberties + + + align:start position:0% +comes to human rights civil liberties +than both the u.s. Revolution and the + + align:start position:0% +than both the u.s. Revolution and the + + + align:start position:0% +than both the u.s. Revolution and the +French one and the question that I asked + + align:start position:0% +French one and the question that I asked + + + align:start position:0% +French one and the question that I asked +them is why is it that they went through + + align:start position:0% +them is why is it that they went through + + + align:start position:0% +them is why is it that they went through +the the elementary school the high + + align:start position:0% +the the elementary school the high + + + align:start position:0% +the the elementary school the high +school some of them most of the college + + align:start position:0% +school some of them most of the college + + + align:start position:0% +school some of them most of the college +years without ever hearing about the + + align:start position:0% +years without ever hearing about the + + + align:start position:0% +years without ever hearing about the +Haitian Revolution right which in fact + + align:start position:0% +Haitian Revolution right which in fact + + + align:start position:0% +Haitian Revolution right which in fact +has has been much more potent than both + + align:start position:0% +has has been much more potent than both + + + align:start position:0% +has has been much more potent than both +the French one and the u.s. one and to + + align:start position:0% +the French one and the u.s. one and to + + + align:start position:0% +the French one and the u.s. one and to +me that that was a great way to + + align:start position:0% +me that that was a great way to + + + align:start position:0% +me that that was a great way to +introduced to them the idea that you + + align:start position:0% +introduced to them the idea that you + + + align:start position:0% +introduced to them the idea that you +have to stay work you have to understand + + align:start position:0% +have to stay work you have to understand + + + align:start position:0% +have to stay work you have to understand +why history is being taught in such a + + align:start position:0% +why history is being taught in such a + + + align:start position:0% +why history is being taught in such a +bad way that excludes the one revolution + + align:start position:0% +bad way that excludes the one revolution + + + align:start position:0% +bad way that excludes the one revolution +that actually allowed this concept of + + align:start position:0% +that actually allowed this concept of + + + align:start position:0% +that actually allowed this concept of +equality among all human beings to + + align:start position:0% +equality among all human beings to + + + align:start position:0% +equality among all human beings to +become true because both in France and + + align:start position:0% +become true because both in France and + + + align:start position:0% +become true because both in France and +in the u.s. when they were claiming + + align:start position:0% +in the u.s. when they were claiming + + + align:start position:0% +in the u.s. when they were claiming +liberty equality fraternity they were + + align:start position:0% +liberty equality fraternity they were + + + align:start position:0% +liberty equality fraternity they were +still people who were in Chains you know + + align:start position:0% +still people who were in Chains you know + + + align:start position:0% +still people who were in Chains you know +in fact blacks were still in in in in + + align:start position:0% +in fact blacks were still in in in in + + + align:start position:0% +in fact blacks were still in in in in +slavery women couldn't vote it's only in + + align:start position:0% +slavery women couldn't vote it's only in + + + align:start position:0% +slavery women couldn't vote it's only in +Haiti that revolution took its real + + align:start position:0% +Haiti that revolution took its real + + + align:start position:0% +Haiti that revolution took its real +meaning in really changing the world + + align:start position:0% +meaning in really changing the world + + + align:start position:0% +meaning in really changing the world +order in creating this possibility for + + align:start position:0% +order in creating this possibility for + + + align:start position:0% +order in creating this possibility for +all human beings to be equal but yet + + align:start position:0% +all human beings to be equal but yet + + + align:start position:0% +all human beings to be equal but yet +it's not taught in the classroom in the + + align:start position:0% +it's not taught in the classroom in the + + + align:start position:0% +it's not taught in the classroom in the +US and to me that's one of the most + + align:start position:0% +US and to me that's one of the most + + + align:start position:0% +US and to me that's one of the most +blatant case of thick news that's become + + align:start position:0% +blatant case of thick news that's become + + + align:start position:0% +blatant case of thick news that's become +so much part of the way children are + + align:start position:0% +so much part of the way children are + + + align:start position:0% +so much part of the way children are +educated in the u.s. so stair walk means + + align:start position:0% +educated in the u.s. so stair walk means + + + align:start position:0% +educated in the u.s. so stair walk means +to be alert to this kind of propaganda + + align:start position:0% +to be alert to this kind of propaganda + + + align:start position:0% +to be alert to this kind of propaganda +that that passes for history that's they + + align:start position:0% +that that passes for history that's they + + + align:start position:0% +that that passes for history that's they +work and of course we look at other + + align:start position:0% +work and of course we look at other + + + align:start position:0% +work and of course we look at other +examples where they themselves + + align:start position:0% +examples where they themselves + + + align:start position:0% +examples where they themselves +participate in these areas of knowledge + + align:start position:0% +participate in these areas of knowledge + + + align:start position:0% +participate in these areas of knowledge +actually subserve hierarchies of power + + align:start position:0% +actually subserve hierarchies of power + + + align:start position:0% +actually subserve hierarchies of power +that's that stay work \ No newline at end of file diff --git a/WyMF3TNm_UU.txt b/WyMF3TNm_UU.txt new file mode 100644 index 0000000000000000000000000000000000000000..12fcd73295e4a07a68ee4483d954861510175616 --- /dev/null +++ b/WyMF3TNm_UU.txt @@ -0,0 +1,747 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu we're now going to look at + + align:start position:0% +ocw.mit.edu we're now going to look at + + + align:start position:0% +ocw.mit.edu we're now going to look at +another laser the Argon + + align:start position:0% +another laser the Argon + + + align:start position:0% +another laser the Argon +laser it's much more powerful than a + + align:start position:0% +laser it's much more powerful than a + + + align:start position:0% +laser it's much more powerful than a +helium neon laser in fact it can put out + + align:start position:0% +helium neon laser in fact it can put out + + + align:start position:0% +helium neon laser in fact it can put out +several watts and even several tens of + + align:start position:0% +several watts and even several tens of + + + align:start position:0% +several watts and even several tens of +watts principally in the blue in the + + align:start position:0% +watts principally in the blue in the + + + align:start position:0% +watts principally in the blue in the +green and also in the + + align:start position:0% +green and also in the + + + align:start position:0% +green and also in the +ultraviolet in this first + + align:start position:0% +ultraviolet in this first + + + align:start position:0% +ultraviolet in this first +demonstration we're going to take the + + align:start position:0% +demonstration we're going to take the + + + align:start position:0% +demonstration we're going to take the +output of this argon laser + + align:start position:0% +output of this argon laser + + + align:start position:0% +output of this argon laser +here and without focusing it we're going + + align:start position:0% +here and without focusing it we're going + + + align:start position:0% +here and without focusing it we're going +to send it onto a piece of + + align:start position:0% +to send it onto a piece of + + + align:start position:0% +to send it onto a piece of +cardboard and we want to show you what + + align:start position:0% +cardboard and we want to show you what + + + align:start position:0% +cardboard and we want to show you what +happened + + align:start position:0% + + + + align:start position:0% + +now here you see the Argon + + align:start position:0% +now here you see the Argon + + + align:start position:0% +now here you see the Argon +laser puts out about two Watts or so in + + align:start position:0% +laser puts out about two Watts or so in + + + align:start position:0% +laser puts out about two Watts or so in +the in the blue and green the blue is + + align:start position:0% +the in the blue and green the blue is + + + align:start position:0% +the in the blue and green the blue is +around 48 80 angstroms the green is + + align:start position:0% +around 48 80 angstroms the green is + + + align:start position:0% +around 48 80 angstroms the green is +around + + align:start position:0% +around + + + align:start position:0% +around +5145 and other weaker wavelengths both + + align:start position:0% +5145 and other weaker wavelengths both + + + align:start position:0% +5145 and other weaker wavelengths both +in the visible and also in the + + align:start position:0% +in the visible and also in the + + + align:start position:0% +in the visible and also in the +ultraviolet you can't see very much of + + align:start position:0% +ultraviolet you can't see very much of + + + align:start position:0% +ultraviolet you can't see very much of +the laser so what we're going to to do + + align:start position:0% +the laser so what we're going to to do + + + align:start position:0% +the laser so what we're going to to do +is take the top off so you can get a + + align:start position:0% +is take the top off so you can get a + + + align:start position:0% +is take the top off so you can get a +closer look at what's inside this + + align:start position:0% +closer look at what's inside this + + + align:start position:0% +closer look at what's inside this +laser here is the Argon laser without + + align:start position:0% +laser here is the Argon laser without + + + align:start position:0% +laser here is the Argon laser without +the top + + align:start position:0% +the top + + + align:start position:0% +the top +on certainly looks very complicated but + + align:start position:0% +on certainly looks very complicated but + + + align:start position:0% +on certainly looks very complicated but +I'll try and help you along by + + align:start position:0% +I'll try and help you along by + + + align:start position:0% +I'll try and help you along by +identifying some of the important + + align:start position:0% +identifying some of the important + + + align:start position:0% +identifying some of the important +features in the + + align:start position:0% +features in the + + + align:start position:0% +features in the +laser and we'll do this in in close-up + + align:start position:0% +laser and we'll do this in in close-up + + + align:start position:0% +laser and we'll do this in in close-up +so first let's zoom in to the left side + + align:start position:0% +so first let's zoom in to the left side + + + align:start position:0% +so first let's zoom in to the left side +of the of the laser + + align:start position:0% + + + + align:start position:0% + +where we see the mirror + + align:start position:0% +where we see the mirror + + + align:start position:0% +where we see the mirror +Mount that holds one of the laser + + align:start position:0% +Mount that holds one of the laser + + + align:start position:0% +Mount that holds one of the laser +mirrors so the mirror Mount the mirror + + align:start position:0% +mirrors so the mirror Mount the mirror + + + align:start position:0% +mirrors so the mirror Mount the mirror +is is held down there and then the air + + align:start position:0% +is is held down there and then the air + + + align:start position:0% +is is held down there and then the air +path between the mirror and the + + align:start position:0% +path between the mirror and the + + + align:start position:0% +path between the mirror and the +discharge tube is sealed with Bellows + + align:start position:0% +discharge tube is sealed with Bellows + + + align:start position:0% +discharge tube is sealed with Bellows +over + + align:start position:0% +over + + + align:start position:0% +over +here and here is then the beginning of + + align:start position:0% +here and here is then the beginning of + + + align:start position:0% +here and here is then the beginning of +the discharge + + align:start position:0% +the discharge + + + align:start position:0% +the discharge +tube here you see the + + align:start position:0% +tube here you see the + + + align:start position:0% +tube here you see the +cathode the big cathode for this uh for + + align:start position:0% +cathode the big cathode for this uh for + + + align:start position:0% +cathode the big cathode for this uh for +this + + align:start position:0% +this + + + align:start position:0% +this +laser the bore of the tube + + align:start position:0% +laser the bore of the tube + + + align:start position:0% +laser the bore of the tube +is inside this this magnet so you can't + + align:start position:0% +is inside this this magnet so you can't + + + align:start position:0% +is inside this this magnet so you can't +see + + align:start position:0% +see + + + align:start position:0% +see +it and then there is this uh this magnet + + align:start position:0% +it and then there is this uh this magnet + + + align:start position:0% +it and then there is this uh this magnet +here to that provides a longitudinal + + align:start position:0% +here to that provides a longitudinal + + + align:start position:0% +here to that provides a longitudinal +magnetic field so here's the the magnet + + align:start position:0% +magnetic field so here's the the magnet + + + align:start position:0% +magnetic field so here's the the magnet +and then the + + align:start position:0% +and then the + + + align:start position:0% +and then the +anode is located located over + + align:start position:0% +anode is located located over + + + align:start position:0% +anode is located located over +here now because this is a + + align:start position:0% +here now because this is a + + + align:start position:0% +here now because this is a +a powerful Arc + + align:start position:0% +a powerful Arc + + + align:start position:0% +a powerful Arc +discharge both the bore and the magnet + + align:start position:0% +discharge both the bore and the magnet + + + align:start position:0% +discharge both the bore and the magnet +are water + + align:start position:0% + + + + align:start position:0% + +cool over here you see that the + + align:start position:0% +cool over here you see that the + + + align:start position:0% +cool over here you see that the +discharge tube is terminated with a + + align:start position:0% +discharge tube is terminated with a + + + align:start position:0% +discharge tube is terminated with a +window at Brewster's + + align:start position:0% +window at Brewster's + + + align:start position:0% +window at Brewster's +angle and + + align:start position:0% +angle and + + + align:start position:0% +angle and +finally the second mirror is mounted in + + align:start position:0% +finally the second mirror is mounted in + + + align:start position:0% +finally the second mirror is mounted in +this in this holder over here + + align:start position:0% + + + + align:start position:0% + +now we're going to turn the power on and + + align:start position:0% +now we're going to turn the power on and + + + align:start position:0% +now we're going to turn the power on and +and look at the + + align:start position:0% +and look at the + + + align:start position:0% +and look at the +output now the Argon laser puts out a + + align:start position:0% +output now the Argon laser puts out a + + + align:start position:0% +output now the Argon laser puts out a +lot of power as it said around one or + + align:start position:0% +lot of power as it said around one or + + + align:start position:0% +lot of power as it said around one or +two Watts from this + + align:start position:0% +two Watts from this + + + align:start position:0% +two Watts from this +laser and one thing you don't want to do + + align:start position:0% +laser and one thing you don't want to do + + + align:start position:0% +laser and one thing you don't want to do +is get in the way of the + + align:start position:0% +is get in the way of the + + + align:start position:0% +is get in the way of the +beam now here we see a piece of + + align:start position:0% +beam now here we see a piece of + + + align:start position:0% +beam now here we see a piece of +cardboard that's unlucky enough to be in + + align:start position:0% +cardboard that's unlucky enough to be in + + + align:start position:0% +cardboard that's unlucky enough to be in +the way of even an unfocused beam so if + + align:start position:0% +the way of even an unfocused beam so if + + + align:start position:0% +the way of even an unfocused beam so if +we turn up the power in the Argon laser + + align:start position:0% +we turn up the power in the Argon laser + + + align:start position:0% +we turn up the power in the Argon laser +you see what happens + + align:start position:0% +you see what happens + + + align:start position:0% +you see what happens +you + + align:start position:0% +you + + + align:start position:0% +you +see nice hole burnt in and and and lots + + align:start position:0% +see nice hole burnt in and and and lots + + + align:start position:0% +see nice hole burnt in and and and lots +of smoke comes out and this is remember + + align:start position:0% +of smoke comes out and this is remember + + + align:start position:0% +of smoke comes out and this is remember +this is the unfocused beam we have about + + align:start position:0% +this is the unfocused beam we have about + + + align:start position:0% +this is the unfocused beam we have about +one watt of + + align:start position:0% + + + + align:start position:0% + +power and here's the hole we just burned + + align:start position:0% +power and here's the hole we just burned + + + align:start position:0% +power and here's the hole we just burned +in the pie of + + align:start position:0% + + + + align:start position:0% + +cardboard looks pretty + + align:start position:0% + + + + align:start position:0% + +bad and remember this is the unfocused + + align:start position:0% +bad and remember this is the unfocused + + + align:start position:0% +bad and remember this is the unfocused +Argon beam \ No newline at end of file diff --git a/Z4iE3aaNeTM.txt b/Z4iE3aaNeTM.txt new file mode 100644 index 0000000000000000000000000000000000000000..d526841c20f654635797b13854dc7ae31fa23f3f --- /dev/null +++ b/Z4iE3aaNeTM.txt @@ -0,0 +1,8371 @@ +align:start position:0% + +okay glad everybody made it through the + + align:start position:0% +okay glad everybody made it through the + + + align:start position:0% +okay glad everybody made it through the +snow why don't we get + + align:start position:0% +snow why don't we get + + + align:start position:0% +snow why don't we get +started um for so what we're going to do + + align:start position:0% +started um for so what we're going to do + + + align:start position:0% +started um for so what we're going to do +is today is we're going to start talking + + align:start position:0% +is today is we're going to start talking + + + align:start position:0% +is today is we're going to start talking +about magnetics because in the middle of + + align:start position:0% +about magnetics because in the middle of + + + align:start position:0% +about magnetics because in the middle of +most power converters there's some + + align:start position:0% +most power converters there's some + + + align:start position:0% +most power converters there's some +magnetic component or more than one + + align:start position:0% +magnetic component or more than one + + + align:start position:0% +magnetic component or more than one +magnetic component so we we all to + + align:start position:0% +magnetic component so we we all to + + + align:start position:0% +magnetic component so we we all to +understand them and know how to design + + align:start position:0% +understand them and know how to design + + + align:start position:0% +understand them and know how to design +them um what I'm going to be about today + + align:start position:0% +them um what I'm going to be about today + + + align:start position:0% +them um what I'm going to be about today +in particular is in principles of Power + + align:start position:0% +in particular is in principles of Power + + + align:start position:0% +in particular is in principles of Power +Electronics chapter 18 so I'll try to + + align:start position:0% +Electronics chapter 18 so I'll try to + + + align:start position:0% +Electronics chapter 18 so I'll try to +make sure that's in the correct reading + + align:start position:0% +make sure that's in the correct reading + + + align:start position:0% +make sure that's in the correct reading +for the for the homework + + align:start position:0% +for the for the homework + + + align:start position:0% +for the for the homework +set and what I'd like to do is start by + + align:start position:0% +set and what I'd like to do is start by + + + align:start position:0% +set and what I'd like to do is start by +just reminding everybody of how this was + + align:start position:0% +just reminding everybody of how this was + + + align:start position:0% +just reminding everybody of how this was +likely treated in your introduction to + + align:start position:0% +likely treated in your introduction to + + + align:start position:0% +likely treated in your introduction to +physics class you know straight from + + align:start position:0% +physics class you know straight from + + + align:start position:0% +physics class you know straight from +Maxwell's equations and then I want to + + align:start position:0% +Maxwell's equations and then I want to + + + align:start position:0% +Maxwell's equations and then I want to +sort of step back and come up with some + + align:start position:0% +sort of step back and come up with some + + + align:start position:0% +sort of step back and come up with some +models that simplify things magnetic + + align:start position:0% +models that simplify things magnetic + + + align:start position:0% +models that simplify things magnetic +circuit models that let you understand + + align:start position:0% +circuit models that let you understand + + + align:start position:0% +circuit models that let you understand +the behavior of magnetic components + + align:start position:0% +the behavior of magnetic components + + + align:start position:0% +the behavior of magnetic components +without having to write Maxwell's + + align:start position:0% +without having to write Maxwell's + + + align:start position:0% +without having to write Maxwell's +equations left right in center okay so + + align:start position:0% +equations left right in center okay so + + + align:start position:0% +equations left right in center okay so +let's just remind us ourselves of the + + align:start position:0% +let's just remind us ourselves of the + + + align:start position:0% +let's just remind us ourselves of the +integral form of Maxwell's equations + + align:start position:0% +integral form of Maxwell's equations + + + align:start position:0% +integral form of Maxwell's equations +right so we have ampers + + align:start position:0% + + + + align:start position:0% + +law right which basically says the + + align:start position:0% +law right which basically says the + + + align:start position:0% +law right which basically says the +integral of h. + + align:start position:0% +integral of h. + + + align:start position:0% +integral of h. +DL is equal to the integral of j. + + align:start position:0% +DL is equal to the integral of j. + + + align:start position:0% +DL is equal to the integral of j. +da plus + + align:start position:0% +da plus + + + align:start position:0% +da plus +DDT of the integral of Epsilon + + align:start position:0% +DDT of the integral of Epsilon + + + align:start position:0% +DDT of the integral of Epsilon +Epsilon e. da all right this is + + align:start position:0% +Epsilon e. da all right this is + + + align:start position:0% +Epsilon e. da all right this is +displacement current we're going to do + + align:start position:0% +displacement current we're going to do + + + align:start position:0% +displacement current we're going to do +the mqs + + align:start position:0% +the mqs + + + align:start position:0% +the mqs +approximation Magneto quas athetic + + align:start position:0% +approximation Magneto quas athetic + + + align:start position:0% +approximation Magneto quas athetic +approximation where we + + align:start position:0% +approximation where we + + + align:start position:0% +approximation where we +ignore uh the effect of changing + + align:start position:0% +ignore uh the effect of changing + + + align:start position:0% +ignore uh the effect of changing +electric Fields we're ignoring + + align:start position:0% +electric Fields we're ignoring + + + align:start position:0% +electric Fields we're ignoring +displacement current right so basically + + align:start position:0% +displacement current right so basically + + + align:start position:0% +displacement current right so basically +this just says that if I integrate the + + align:start position:0% +this just says that if I integrate the + + + align:start position:0% +this just says that if I integrate the +magnetic field around a loop it + + align:start position:0% +magnetic field around a loop it + + + align:start position:0% +magnetic field around a loop it +basically equals the net current that's + + align:start position:0% +basically equals the net current that's + + + align:start position:0% +basically equals the net current that's +passing through that Loop okay + + align:start position:0% +passing through that Loop okay + + + align:start position:0% +passing through that Loop okay +the next thing we're interested in is + + align:start position:0% +the next thing we're interested in is + + + align:start position:0% +the next thing we're interested in is +Faraday's + + align:start position:0% + + + + align:start position:0% + +law right which says that the integral + + align:start position:0% +law right which says that the integral + + + align:start position:0% +law right which says that the integral +of e. DL around a loop the integral of + + align:start position:0% +of e. DL around a loop the integral of + + + align:start position:0% +of e. DL around a loop the integral of +the electric field around a loop is + + align:start position:0% +the electric field around a loop is + + + align:start position:0% +the electric field around a loop is +minus the derivative of the + + align:start position:0% +minus the derivative of the + + + align:start position:0% +minus the derivative of the +integral of b. da that is the minus the + + align:start position:0% +integral of b. da that is the minus the + + + align:start position:0% +integral of b. da that is the minus the +derivative of the total magnetic flux + + align:start position:0% +derivative of the total magnetic flux + + + align:start position:0% +derivative of the total magnetic flux +linked by that Loop okay that's the sort + + align:start position:0% +linked by that Loop okay that's the sort + + + align:start position:0% +linked by that Loop okay that's the sort +of the source of induced voltage + + align:start position:0% +of the source of induced voltage + + + align:start position:0% +of the source of induced voltage +Okay the third one we're going to be + + align:start position:0% +Okay the third one we're going to be + + + align:start position:0% +Okay the third one we're going to be +interested in is flux + + align:start position:0% + + + + align:start position:0% + +continuity which is basically saying + + align:start position:0% +continuity which is basically saying + + + align:start position:0% +continuity which is basically saying +there is no magnetic charge that is the + + align:start position:0% +there is no magnetic charge that is the + + + align:start position:0% +there is no magnetic charge that is the +integral of b. da the net + + align:start position:0% +integral of b. da the net + + + align:start position:0% +integral of b. da the net +flux uh coming out of some volume is + + align:start position:0% +flux uh coming out of some volume is + + + align:start position:0% +flux uh coming out of some volume is +zero okay so these are what we're going + + align:start position:0% +zero okay so these are what we're going + + + align:start position:0% +zero okay so these are what we're going +to be concerned with in terms of + + align:start position:0% +to be concerned with in terms of + + + align:start position:0% +to be concerned with in terms of +Designing magnetic components there's + + align:start position:0% +Designing magnetic components there's + + + align:start position:0% +Designing magnetic components there's +also gauss's law but we're just not + + align:start position:0% +also gauss's law but we're just not + + + align:start position:0% +also gauss's law but we're just not +going to use ga's law + + align:start position:0% +going to use ga's law + + + align:start position:0% +going to use ga's law +okay um just as a + + align:start position:0% +okay um just as a + + + align:start position:0% +okay um just as a +reminder here + + align:start position:0% +reminder here + + + align:start position:0% +reminder here +H is magnetic field + + align:start position:0% + + + + align:start position:0% + +intensity which we usually use as ampi + + align:start position:0% +intensity which we usually use as ampi + + + align:start position:0% +intensity which we usually use as ampi +per meter as units + + align:start position:0% +per meter as units + + + align:start position:0% +per meter as units +B is magnetic flux density + + align:start position:0% + + + + align:start position:0% + +and that's usually in units of + + align:start position:0% +and that's usually in units of + + + align:start position:0% +and that's usually in units of +Tesla okay and there's some + + align:start position:0% +Tesla okay and there's some + + + align:start position:0% +Tesla okay and there's some +relationship between B and H right um + + align:start position:0% +relationship between B and H right um + + + align:start position:0% +relationship between B and H right um +more generally right B is equal to Mu h + + align:start position:0% +more generally right B is equal to Mu h + + + align:start position:0% +more generally right B is equal to Mu h +plus the + + align:start position:0% +plus the + + + align:start position:0% +plus the +magnetization that relates to what's + + align:start position:0% +magnetization that relates to what's + + + align:start position:0% +magnetization that relates to what's +going on in the + + align:start position:0% +going on in the + + + align:start position:0% +going on in the +material for our purposes we're going to + + align:start position:0% +material for our purposes we're going to + + + align:start position:0% +material for our purposes we're going to +consider just soft permeable materials + + align:start position:0% +consider just soft permeable materials + + + align:start position:0% +consider just soft permeable materials +and we're going to say okay we can write + + align:start position:0% +and we're going to say okay we can write + + + align:start position:0% +and we're going to say okay we can write +b as being equal to + + align:start position:0% +b as being equal to + + + align:start position:0% +b as being equal to +Mu where mu is the + + align:start position:0% + + + + align:start position:0% + +permeability + + align:start position:0% +permeability + + + align:start position:0% +permeability +okay and so we're we're assuming B and H + + align:start position:0% +okay and so we're we're assuming B and H + + + align:start position:0% +okay and so we're we're assuming B and H +are proportional okay and remember that + + align:start position:0% +are proportional okay and remember that + + + align:start position:0% +are proportional okay and remember that +mu KN the permeability of free space is + + align:start position:0% +mu KN the permeability of free space is + + + align:start position:0% +mu KN the permeability of free space is +4 piun * 10us 7 Henry's per meter okay + + align:start position:0% +4 piun * 10us 7 Henry's per meter okay + + + align:start position:0% +4 piun * 10us 7 Henry's per meter okay +okay in general I should say that this + + align:start position:0% +okay in general I should say that this + + + align:start position:0% +okay in general I should say that this +is a simplification right that that um + + align:start position:0% +is a simplification right that that um + + + align:start position:0% +is a simplification right that that um +happens when you have magnetics domains + + align:start position:0% +happens when you have magnetics domains + + + align:start position:0% +happens when you have magnetics domains +that can align due to an imposed field + + align:start position:0% +that can align due to an imposed field + + + align:start position:0% +that can align due to an imposed field +more generally might one might have B is + + align:start position:0% +more generally might one might have B is + + + align:start position:0% +more generally might one might have B is +some function of H and in fact it might + + align:start position:0% +some function of H and in fact it might + + + align:start position:0% +some function of H and in fact it might +even be a function of the instantaneous + + align:start position:0% +even be a function of the instantaneous + + + align:start position:0% +even be a function of the instantaneous +H field and history okay so in general + + align:start position:0% +H field and history okay so in general + + + align:start position:0% +H field and history okay so in general +the relationship between B and H can be + + align:start position:0% +the relationship between B and H can be + + + align:start position:0% +the relationship between B and H can be +somewhat complex and we'll see that + + align:start position:0% +somewhat complex and we'll see that + + + align:start position:0% +somewhat complex and we'll see that +moving + + align:start position:0% +moving + + + align:start position:0% +moving +forward but for Simplicity let's just + + align:start position:0% +forward but for Simplicity let's just + + + align:start position:0% +forward but for Simplicity let's just +think about having some permeability mu + + align:start position:0% +think about having some permeability mu + + + align:start position:0% +think about having some permeability mu +which is some relative permeability + + align:start position:0% +which is some relative permeability + + + align:start position:0% +which is some relative permeability +times + + align:start position:0% +times + + + align:start position:0% +times +mu okay so you know those are our basic + + align:start position:0% +mu okay so you know those are our basic + + + align:start position:0% +mu okay so you know those are our basic +rules that we're going to work with Okay + + align:start position:0% +rules that we're going to work with Okay + + + align:start position:0% +rules that we're going to work with Okay +and hopefully you recall these from + + align:start position:0% +and hopefully you recall these from + + + align:start position:0% +and hopefully you recall these from +introductory physics or any more + + align:start position:0% +introductory physics or any more + + + align:start position:0% +introductory physics or any more +advanced magnetics + + align:start position:0% +advanced magnetics + + + align:start position:0% +advanced magnetics +class let's consider uh calculation of + + align:start position:0% +class let's consider uh calculation of + + + align:start position:0% +class let's consider uh calculation of +an inductance right so this is something + + align:start position:0% +an inductance right so this is something + + + align:start position:0% +an inductance right so this is something +that usually most introductory physics + + align:start position:0% +that usually most introductory physics + + + align:start position:0% +that usually most introductory physics +class do and I want to go through it in + + align:start position:0% +class do and I want to go through it in + + + align:start position:0% +class do and I want to go through it in +part to remind you of how we use these + + align:start position:0% +part to remind you of how we use these + + + align:start position:0% +part to remind you of how we use these +rules to get to it and because it'll + + align:start position:0% +rules to get to it and because it'll + + + align:start position:0% +rules to get to it and because it'll +also set up sort of the better way to do + + align:start position:0% +also set up sort of the better way to do + + + align:start position:0% +also set up sort of the better way to do +it or not the better way the simpler way + + align:start position:0% +it or not the better way the simpler way + + + align:start position:0% +it or not the better way the simpler way +to handle all these things okay so let's + + align:start position:0% +to handle all these things okay so let's + + + align:start position:0% +to handle all these things okay so let's +suppose we just have a uh a toid + + align:start position:0% +suppose we just have a uh a toid + + + align:start position:0% +suppose we just have a uh a toid +okay so here we have some + + align:start position:0% +okay so here we have some + + + align:start position:0% +okay so here we have some +toroidal structure + + align:start position:0% +toroidal structure + + + align:start position:0% +toroidal structure +okay and I'm going to come up and I'm + + align:start position:0% +okay and I'm going to come up and I'm + + + align:start position:0% +okay and I'm going to come up and I'm +going to put a set of windings on on it + + align:start position:0% +going to put a set of windings on on it + + + align:start position:0% +going to put a set of windings on on it +right so here's some a set of turns that + + align:start position:0% +right so here's some a set of turns that + + + align:start position:0% +right so here's some a set of turns that +I'm going to put on it of + + align:start position:0% +I'm going to put on it of + + + align:start position:0% +I'm going to put on it of +wire right like this okay and let's + + align:start position:0% +wire right like this okay and let's + + + align:start position:0% +wire right like this okay and let's +suppose I put n turns of wire on it and + + align:start position:0% +suppose I put n turns of wire on it and + + + align:start position:0% +suppose I put n turns of wire on it and +I have some current flowing into it I + + align:start position:0% +I have some current flowing into it I + + + align:start position:0% +I have some current flowing into it I +right so + + align:start position:0% +right so + + + align:start position:0% +right so +there's end turns of wire each with end + + align:start position:0% +there's end turns of wire each with end + + + align:start position:0% +there's end turns of wire each with end +turns of wire that has a current I + + align:start position:0% +turns of wire that has a current I + + + align:start position:0% +turns of wire that has a current I +through it + + align:start position:0% +through it + + + align:start position:0% +through it +okay and what I want to do is + + align:start position:0% +okay and what I want to do is + + + align:start position:0% +okay and what I want to do is +essentially find out what the inductance + + align:start position:0% +essentially find out what the inductance + + + align:start position:0% +essentially find out what the inductance +of this structure is okay and I'm going + + align:start position:0% +of this structure is okay and I'm going + + + align:start position:0% +of this structure is okay and I'm going +to make some + + align:start position:0% +to make some + + + align:start position:0% +to make some +approximations I'm going to assume that + + align:start position:0% +approximations I'm going to assume that + + + align:start position:0% +approximations I'm going to assume that +this core magnetic core okay has some + + align:start position:0% +this core magnetic core okay has some + + + align:start position:0% +this core magnetic core okay has some +permeability mu which is much greater + + align:start position:0% +permeability mu which is much greater + + + align:start position:0% +permeability mu which is much greater +than mu KN it has some cross-sectional + + align:start position:0% +than mu KN it has some cross-sectional + + + align:start position:0% +than mu KN it has some cross-sectional +area that I'm going to call area of the + + align:start position:0% +area that I'm going to call area of the + + + align:start position:0% +area that I'm going to call area of the +core some length that I'm going to call + + align:start position:0% +core some length that I'm going to call + + + align:start position:0% +core some length that I'm going to call +the length of the core + + align:start position:0% +the length of the core + + + align:start position:0% +the length of the core +okay and so and I'm going to assume that + + align:start position:0% +okay and so and I'm going to assume that + + + align:start position:0% +okay and so and I'm going to assume that +sort of this radius is fairly large + + align:start position:0% +sort of this radius is fairly large + + + align:start position:0% +sort of this radius is fairly large +compared to the dimens of the core such + + align:start position:0% +compared to the dimens of the core such + + + align:start position:0% +compared to the dimens of the core such +the the fields inside the core are + + align:start position:0% +the the fields inside the core are + + + align:start position:0% +the the fields inside the core are +roughly uniform right so I'm kind of + + align:start position:0% +roughly uniform right so I'm kind of + + + align:start position:0% +roughly uniform right so I'm kind of +taking the simplest case just so we can + + align:start position:0% +taking the simplest case just so we can + + + align:start position:0% +taking the simplest case just so we can +see what's going on okay what do I want + + align:start position:0% +see what's going on okay what do I want + + + align:start position:0% +see what's going on okay what do I want +to do to find the inductance of this + + align:start position:0% +to do to find the inductance of this + + + align:start position:0% +to do to find the inductance of this +inductor okay I'll I'll kind of outline + + align:start position:0% +inductor okay I'll I'll kind of outline + + + align:start position:0% +inductor okay I'll I'll kind of outline +it as three steps one I'm going to find + + align:start position:0% +it as three steps one I'm going to find + + + align:start position:0% +it as three steps one I'm going to find +the H + + align:start position:0% +the H + + + align:start position:0% +the H +field in the + + align:start position:0% +field in the + + + align:start position:0% +field in the +core then I'm going to find the flux in + + align:start position:0% +core then I'm going to find the flux in + + + align:start position:0% +core then I'm going to find the flux in +the + + align:start position:0% +the + + + align:start position:0% +the +core okay then I'm going to find the + + align:start position:0% +core okay then I'm going to find the + + + align:start position:0% +core okay then I'm going to find the +flux link in the core Lambda and we have + + align:start position:0% +flux link in the core Lambda and we have + + + align:start position:0% +flux link in the core Lambda and we have +Lambda is equal to Li in other words the + + align:start position:0% +Lambda is equal to Li in other words the + + + align:start position:0% +Lambda is equal to Li in other words the +flux linkage in the core is proportional + + align:start position:0% +flux linkage in the core is proportional + + + align:start position:0% +flux linkage in the core is proportional +to the current okay and I want to find + + align:start position:0% +to the current okay and I want to find + + + align:start position:0% +to the current okay and I want to find +that proportionality constant and if you + + align:start position:0% +that proportionality constant and if you + + + align:start position:0% +that proportionality constant and if you +don't recall what flux linkage is we'll + + align:start position:0% +don't recall what flux linkage is we'll + + + align:start position:0% +don't recall what flux linkage is we'll +come back to it all right so any + + align:start position:0% +come back to it all right so any + + + align:start position:0% +come back to it all right so any +questions about what we're trying to + + align:start position:0% + + + + align:start position:0% + +do okay so let's start about finding the + + align:start position:0% +do okay so let's start about finding the + + + align:start position:0% +do okay so let's start about finding the +H field in the core right so you know + + align:start position:0% +H field in the core right so you know + + + align:start position:0% +H field in the core right so you know +what I'm assuming is that there is going + + align:start position:0% +what I'm assuming is that there is going + + + align:start position:0% +what I'm assuming is that there is going +to be some H field owing to + + align:start position:0% +to be some H field owing to + + + align:start position:0% +to be some H field owing to +this set of turns on the core with the + + align:start position:0% +this set of turns on the core with the + + + align:start position:0% +this set of turns on the core with the +winding there's going to be some H field + + align:start position:0% +winding there's going to be some H field + + + align:start position:0% +winding there's going to be some H field +inside this core this way okay so what + + align:start position:0% +inside this core this way okay so what + + + align:start position:0% +inside this core this way okay so what +do I know I know that the integral of h. + + align:start position:0% +do I know I know that the integral of h. + + + align:start position:0% +do I know I know that the integral of h. +DL is equal to the integral of j. da + + align:start position:0% +DL is equal to the integral of j. da + + + align:start position:0% +DL is equal to the integral of j. da +right well well um I'm going to + + align:start position:0% +right well well um I'm going to + + + align:start position:0% +right well well um I'm going to +integrate around exactly this Loop like + + align:start position:0% +integrate around exactly this Loop like + + + align:start position:0% +integrate around exactly this Loop like +this and how much current is piercing + + align:start position:0% +this and how much current is piercing + + + align:start position:0% +this and how much current is piercing +that Loop right if the Loop's going + + align:start position:0% +that Loop right if the Loop's going + + + align:start position:0% +that Loop right if the Loop's going +through the middle of the core well I + + align:start position:0% +through the middle of the core well I + + + align:start position:0% +through the middle of the core well I +have I and I and I right so there's n + + align:start position:0% +have I and I and I right so there's n + + + align:start position:0% +have I and I and I right so there's n +times I going through that Loop right so + + align:start position:0% +times I going through that Loop right so + + + align:start position:0% +times I going through that Loop right so +the integral of j. da ought to just be + + align:start position:0% +the integral of j. da ought to just be + + + align:start position:0% +the integral of j. da ought to just be +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +ni okay + + align:start position:0% + + + + align:start position:0% + +so if I then take that I can say that + + align:start position:0% +so if I then take that I can say that + + + align:start position:0% +so if I then take that I can say that +okay H integrated around the loop if I + + align:start position:0% +okay H integrated around the loop if I + + + align:start position:0% +okay H integrated around the loop if I +assume it's uniform right what I'm going + + align:start position:0% +assume it's uniform right what I'm going + + + align:start position:0% +assume it's uniform right what I'm going +to get is H * the length of the core is + + align:start position:0% +to get is H * the length of the core is + + + align:start position:0% +to get is H * the length of the core is +equal to ni or H is equal to + + align:start position:0% +equal to ni or H is equal to + + + align:start position:0% +equal to ni or H is equal to +ni over the length of the core okay + + align:start position:0% +ni over the length of the core okay + + + align:start position:0% +ni over the length of the core okay +where this is like 2 pi r of the middle + + align:start position:0% +where this is like 2 pi r of the middle + + + align:start position:0% +where this is like 2 pi r of the middle +of the core any questions about + + align:start position:0% +of the core any questions about + + + align:start position:0% +of the core any questions about +that so does the core kind of like in + + align:start position:0% +that so does the core kind of like in + + + align:start position:0% +that so does the core kind of like in +this circular yeah I'm I'm assuming that + + align:start position:0% +this circular yeah I'm I'm assuming that + + + align:start position:0% +this circular yeah I'm I'm assuming that +the permeability of the core is really + + align:start position:0% +the permeability of the core is really + + + align:start position:0% +the permeability of the core is really +high and yes so so it actually and in + + align:start position:0% +high and yes so so it actually and in + + + align:start position:0% +high and yes so so it actually and in +fact it doesn't in some sense matter + + align:start position:0% +fact it doesn't in some sense matter + + + align:start position:0% +fact it doesn't in some sense matter +right um all I I mean the only + + align:start position:0% +right um all I I mean the only + + + align:start position:0% +right um all I I mean the only +assumption isn't that the the core bends + + align:start position:0% +assumption isn't that the the core bends + + + align:start position:0% +assumption isn't that the the core bends +it I'm just assuming it's + + align:start position:0% +it I'm just assuming it's + + + align:start position:0% +it I'm just assuming it's +everywhere around + + align:start position:0% +everywhere around + + + align:start position:0% +everywhere around +it if you were worried about that + + align:start position:0% +it if you were worried about that + + + align:start position:0% +it if you were worried about that +assumption you could say well suppose I + + align:start position:0% +assumption you could say well suppose I + + + align:start position:0% +assumption you could say well suppose I +distributed the turns exactly evenly + + align:start position:0% +distributed the turns exactly evenly + + + align:start position:0% +distributed the turns exactly evenly +around it the whole way right then + + align:start position:0% +around it the whole way right then + + + align:start position:0% +around it the whole way right then +everything would be sort of rotationally + + align:start position:0% +everything would be sort of rotationally + + + align:start position:0% +everything would be sort of rotationally +symmetric so H ought to be the same + + align:start position:0% +symmetric so H ought to be the same + + + align:start position:0% +symmetric so H ought to be the same +everywhere right and then you know even + + align:start position:0% +everywhere right and then you know even + + + align:start position:0% +everywhere right and then you know even +even if I didn't accept that the the the + + align:start position:0% +even if I didn't accept that the the the + + + align:start position:0% +even if I didn't accept that the the the +field I cared about was going around the + + align:start position:0% +field I cared about was going around the + + + align:start position:0% +field I cared about was going around the +core then then it would be + + align:start position:0% +core then then it would be + + + align:start position:0% +core then then it would be +legit great + + align:start position:0% +legit great + + + align:start position:0% +legit great +question okay so what do I got to find + + align:start position:0% +question okay so what do I got to find + + + align:start position:0% +question okay so what do I got to find +next I got to find the uh magnetic + + align:start position:0% +next I got to find the uh magnetic + + + align:start position:0% +next I got to find the uh magnetic +flux okay well to find the magnetic flux + + align:start position:0% +flux okay well to find the magnetic flux + + + align:start position:0% +flux okay well to find the magnetic flux +um I'm going to assume that b is equal + + align:start position:0% +um I'm going to assume that b is equal + + + align:start position:0% +um I'm going to assume that b is equal +to Mu core H right so I'm interested in + + align:start position:0% +to Mu core H right so I'm interested in + + + align:start position:0% +to Mu core H right so I'm interested in +finding the magnetic flux in the + + align:start position:0% +finding the magnetic flux in the + + + align:start position:0% +finding the magnetic flux in the +core + + align:start position:0% + + + + align:start position:0% + +okay and that magnetic flux is traveling + + align:start position:0% +okay and that magnetic flux is traveling + + + align:start position:0% +okay and that magnetic flux is traveling +around the core okay and it's + + align:start position:0% +around the core okay and it's + + + align:start position:0% +around the core okay and it's +proportional to the H field + + align:start position:0% +proportional to the H field + + + align:start position:0% +proportional to the H field +okay this is flux + + align:start position:0% +okay this is flux + + + align:start position:0% +okay this is flux +density + + align:start position:0% +density + + + align:start position:0% +density +right and the flux itself + + align:start position:0% +right and the flux itself + + + align:start position:0% +right and the flux itself +is equal to the b in the + + align:start position:0% +is equal to the b in the + + + align:start position:0% +is equal to the b in the +core times the cross-sectional area of + + align:start position:0% +core times the cross-sectional area of + + + align:start position:0% +core times the cross-sectional area of +the core right the net flux is the flux + + align:start position:0% +the core right the net flux is the flux + + + align:start position:0% +the core right the net flux is the flux +density times the area Okay so the total + + align:start position:0% +density times the area Okay so the total + + + align:start position:0% +density times the area Okay so the total +flux traveling through this if you want + + align:start position:0% +flux traveling through this if you want + + + align:start position:0% +flux traveling through this if you want +to think of the core sort of a pipe for + + align:start position:0% +to think of the core sort of a pipe for + + + align:start position:0% +to think of the core sort of a pipe for +flux is the b in the core times the area + + align:start position:0% +flux is the b in the core times the area + + + align:start position:0% +flux is the b in the core times the area +of the core so I can work this out to be + + align:start position:0% +of the core so I can work this out to be + + + align:start position:0% +of the core so I can work this out to be +okay uh + + align:start position:0% + + + + align:start position:0% + +muc times n over LC itimes the + + align:start position:0% +muc times n over LC itimes the + + + align:start position:0% +muc times n over LC itimes the +AC okay so here's the net flux in the + + align:start position:0% +AC okay so here's the net flux in the + + + align:start position:0% +AC okay so here's the net flux in the +core okay the flux in the core is + + align:start position:0% +core okay the flux in the core is + + + align:start position:0% +core okay the flux in the core is +proportional to the current with this + + align:start position:0% +proportional to the current with this + + + align:start position:0% +proportional to the current with this +proportionality + + align:start position:0% +proportionality + + + align:start position:0% +proportionality +constant okay any questions about + + align:start position:0% +constant okay any questions about + + + align:start position:0% +constant okay any questions about +that and so in total I have some flux + + align:start position:0% +that and so in total I have some flux + + + align:start position:0% +that and so in total I have some flux +density and so hence there's some net + + align:start position:0% +density and so hence there's some net + + + align:start position:0% +density and so hence there's some net +flux in the core that's kind of + + align:start position:0% +flux in the core that's kind of + + + align:start position:0% +flux in the core that's kind of +traveling around this Loop okay + + align:start position:0% +traveling around this Loop okay + + + align:start position:0% +traveling around this Loop okay +all right so what do I need + + align:start position:0% +all right so what do I need + + + align:start position:0% +all right so what do I need +next what I want to find + + align:start position:0% +next what I want to find + + + align:start position:0% +next what I want to find +next is what's the flux + + align:start position:0% +next is what's the flux + + + align:start position:0% +next is what's the flux +linkage okay well what is the flux + + align:start position:0% +linkage okay well what is the flux + + + align:start position:0% +linkage okay well what is the flux +linkage the flux linkage is the total + + align:start position:0% +linkage the flux linkage is the total + + + align:start position:0% +linkage the flux linkage is the total +flux linking this net + + align:start position:0% +flux linking this net + + + align:start position:0% +flux linking this net +winding all right what does that mean + + align:start position:0% +winding all right what does that mean + + + align:start position:0% +winding all right what does that mean +well I can think about it a certain way + + align:start position:0% +well I can think about it a certain way + + + align:start position:0% +well I can think about it a certain way +how how you know there's some flux + + align:start position:0% +how how you know there's some flux + + + align:start position:0% +how how you know there's some flux +coming around here and it's piercing + + align:start position:0% +coming around here and it's piercing + + + align:start position:0% +coming around here and it's piercing +through the shape + + align:start position:0% +through the shape + + + align:start position:0% +through the shape +caused by this end turn winding right + + align:start position:0% +caused by this end turn winding right + + + align:start position:0% +caused by this end turn winding right +and this helical winding you could have + + align:start position:0% +and this helical winding you could have + + + align:start position:0% +and this helical winding you could have +think of if I dipped this whole helical + + align:start position:0% +think of if I dipped this whole helical + + + align:start position:0% +think of if I dipped this whole helical +winding in a a bath of soapy water and + + align:start position:0% +winding in a a bath of soapy water and + + + align:start position:0% +winding in a a bath of soapy water and +I'd get some kind of surface that's + + align:start position:0% +I'd get some kind of surface that's + + + align:start position:0% +I'd get some kind of surface that's +spiraling up how much net flux pierces + + align:start position:0% +spiraling up how much net flux pierces + + + align:start position:0% +spiraling up how much net flux pierces +that surface is what the flux linkage + + align:start position:0% +that surface is what the flux linkage + + + align:start position:0% +that surface is what the flux linkage +is another way to think about it is okay + + align:start position:0% +is another way to think about it is okay + + + align:start position:0% +is another way to think about it is okay +I have this one turn coming around right + + align:start position:0% +I have this one turn coming around right + + + align:start position:0% +I have this one turn coming around right +so it kind of came around like this into + + align:start position:0% +so it kind of came around like this into + + + align:start position:0% +so it kind of came around like this into +here and so I can think of sort of um + + align:start position:0% +here and so I can think of sort of um + + + align:start position:0% +here and so I can think of sort of um +this point here is per is a kind of a + + align:start position:0% +this point here is per is a kind of a + + + align:start position:0% +this point here is per is a kind of a +loop through which the flux pierces once + + align:start position:0% +loop through which the flux pierces once + + + align:start position:0% +loop through which the flux pierces once +and then there's another turn the next + + align:start position:0% +and then there's another turn the next + + + align:start position:0% +and then there's another turn the next +turn the flux pierces that once another + + align:start position:0% +turn the flux pierces that once another + + + align:start position:0% +turn the flux pierces that once another +turn the flux pierces that once and so + + align:start position:0% +turn the flux pierces that once and so + + + align:start position:0% +turn the flux pierces that once and so +Lambda the flux + + align:start position:0% + + + + align:start position:0% + +linkage the flux linking the whole end + + align:start position:0% +linkage the flux linking the whole end + + + align:start position:0% +linkage the flux linking the whole end +turn winding is just simply n the number + + align:start position:0% +turn winding is just simply n the number + + + align:start position:0% +turn winding is just simply n the number +of turns times the flux in the core + + align:start position:0% +of turns times the flux in the core + + + align:start position:0% +of turns times the flux in the core +okay does that make sense + + align:start position:0% +okay does that make sense + + + align:start position:0% +okay does that make sense +everybody so what does that mean Lambda + + align:start position:0% +everybody so what does that mean Lambda + + + align:start position:0% +everybody so what does that mean Lambda +is then if I just substitute in here I + + align:start position:0% +is then if I just substitute in here I + + + align:start position:0% +is then if I just substitute in here I +get Lambda is equal to uh + + align:start position:0% +get Lambda is equal to uh + + + align:start position:0% +get Lambda is equal to uh +muc AC over + + align:start position:0% +muc AC over + + + align:start position:0% +muc AC over +LC n^ 2 * + + align:start position:0% +LC n^ 2 * + + + align:start position:0% +LC n^ 2 * +I + + align:start position:0% +I + + + align:start position:0% +I +okay and I just said the relationship + + align:start position:0% +okay and I just said the relationship + + + align:start position:0% +okay and I just said the relationship +between the flux linkage and the current + + align:start position:0% +between the flux linkage and the current + + + align:start position:0% +between the flux linkage and the current +is L so this thing + + align:start position:0% + + + + align:start position:0% + +here is + + align:start position:0% + + + + align:start position:0% + +inductance any questions about + + align:start position:0% + + + + align:start position:0% + +that + + align:start position:0% + + + + align:start position:0% + +now what do we mean by that or what is + + align:start position:0% +now what do we mean by that or what is + + + align:start position:0% +now what do we mean by that or what is +the use of that well um voltage the + + align:start position:0% +the use of that well um voltage the + + + align:start position:0% +the use of that well um voltage the +voltage on the winding + + align:start position:0% +voltage on the winding + + + align:start position:0% +voltage on the winding +is equal to uh LD DT but it's also equal + + align:start position:0% +is equal to uh LD DT but it's also equal + + + align:start position:0% +is equal to uh LD DT but it's also equal +to D Lambda DT right the voltage that I + + align:start position:0% +to D Lambda DT right the voltage that I + + + align:start position:0% +to D Lambda DT right the voltage that I +see at that winding so if I have I here + + align:start position:0% +see at that winding so if I have I here + + + align:start position:0% +see at that winding so if I have I here +this voltage + + align:start position:0% +this voltage + + + align:start position:0% +this voltage +here is going to be equal to D Lambda DT + + align:start position:0% +here is going to be equal to D Lambda DT + + + align:start position:0% +here is going to be equal to D Lambda DT +where D Lambda is the the flux Lambda is + + align:start position:0% +where D Lambda is the the flux Lambda is + + + align:start position:0% +where D Lambda is the the flux Lambda is +the flux linking the + + align:start position:0% +the flux linking the + + + align:start position:0% +the flux linking the +winding okay well why is that the case + + align:start position:0% +winding okay well why is that the case + + + align:start position:0% +winding okay well why is that the case +that comes back to Faraday's law right + + align:start position:0% +that comes back to Faraday's law right + + + align:start position:0% +that comes back to Faraday's law right +we said Faraday's law said okay if I had + + align:start position:0% +we said Faraday's law said okay if I had + + + align:start position:0% +we said Faraday's law said okay if I had +for + + align:start position:0% +for + + + align:start position:0% +for +example one turn here coming around the + + align:start position:0% +example one turn here coming around the + + + align:start position:0% +example one turn here coming around the +total integral of e. DL around that + + align:start position:0% +total integral of e. DL around that + + + align:start position:0% +total integral of e. DL around that +gives me an MMF which is equal to the + + align:start position:0% +gives me an MMF which is equal to the + + + align:start position:0% +gives me an MMF which is equal to the +flux linking through that winding so the + + align:start position:0% +flux linking through that winding so the + + + align:start position:0% +flux linking through that winding so the +voltage of one turn the voltage on one + + align:start position:0% +voltage of one turn the voltage on one + + + align:start position:0% +voltage of one turn the voltage on one +turn is D + + align:start position:0% +turn is D + + + align:start position:0% +turn is D +DT right because the integral of b. da + + align:start position:0% +DT right because the integral of b. da + + + align:start position:0% +DT right because the integral of b. da +is f right the voltage on two turns + + align:start position:0% +is f right the voltage on two turns + + + align:start position:0% +is f right the voltage on two turns +total is two D5 DT Etc so for n turns is + + align:start position:0% +total is two D5 DT Etc so for n turns is + + + align:start position:0% +total is two D5 DT Etc so for n turns is +nddt so it ends up being D Lambda + + align:start position:0% +nddt so it ends up being D Lambda + + + align:start position:0% +nddt so it ends up being D Lambda +DT that make sense + + align:start position:0% +DT that make sense + + + align:start position:0% +DT that make sense +everybody each turn is going to see a + + align:start position:0% +everybody each turn is going to see a + + + align:start position:0% +everybody each turn is going to see a +voltage you know this turn is going to + + align:start position:0% +voltage you know this turn is going to + + + align:start position:0% +voltage you know this turn is going to +see a V1 + + align:start position:0% +see a V1 + + + align:start position:0% +see a V1 +turn which is D DT the voltage across + + align:start position:0% +turn which is D DT the voltage across + + + align:start position:0% +turn which is D DT the voltage across +the whole thing is ND DT or DN DT or D + + align:start position:0% +the whole thing is ND DT or DN DT or D + + + align:start position:0% +the whole thing is ND DT or DN DT or D +Lambda + + align:start position:0% +Lambda + + + align:start position:0% +Lambda +DT okay so when I put that together that + + align:start position:0% +DT okay so when I put that together that + + + align:start position:0% +DT okay so when I put that together that +just gives me V is equal to LD + + align:start position:0% +just gives me V is equal to LD + + + align:start position:0% +just gives me V is equal to LD +IDT which is sort of because this is + + align:start position:0% +IDT which is sort of because this is + + + align:start position:0% +IDT which is sort of because this is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +DDT of + + align:start position:0% +DDT of + + + align:start position:0% +DDT of +Li and we get the formula for inductance + + align:start position:0% +Li and we get the formula for inductance + + + align:start position:0% +Li and we get the formula for inductance +that we know and love or formula for how + + align:start position:0% +that we know and love or formula for how + + + align:start position:0% +that we know and love or formula for how +an inductor behaves that we know and + + align:start position:0% +an inductor behaves that we know and + + + align:start position:0% +an inductor behaves that we know and +love okay + + align:start position:0% +love okay + + + align:start position:0% +love okay +yeah I'm sorry could you comment on + + align:start position:0% +yeah I'm sorry could you comment on + + + align:start position:0% +yeah I'm sorry could you comment on +the yeah I mean that's generated by um + + align:start position:0% +the yeah I mean that's generated by um + + + align:start position:0% +the yeah I mean that's generated by um +lens's law and what that essentially + + align:start position:0% +lens's law and what that essentially + + + align:start position:0% +lens's law and what that essentially +says is + + align:start position:0% +says is + + + align:start position:0% +says is +um The Sign of the voltage if I have a + + align:start position:0% +um The Sign of the voltage if I have a + + + align:start position:0% +um The Sign of the voltage if I have a +DDT going through say one Loop the sign + + align:start position:0% +DDT going through say one Loop the sign + + + align:start position:0% +DDT going through say one Loop the sign +of the voltage is such that the current + + align:start position:0% +of the voltage is such that the current + + + align:start position:0% +of the voltage is such that the current +induced by that voltage in an external + + align:start position:0% +induced by that voltage in an external + + + align:start position:0% +induced by that voltage in an external +circuit would oppose the rate of change + + align:start position:0% +circuit would oppose the rate of change + + + align:start position:0% +circuit would oppose the rate of change +of + + align:start position:0% +of + + + align:start position:0% +of +flux okay um and so what that says is + + align:start position:0% +flux okay um and so what that says is + + + align:start position:0% +flux okay um and so what that says is +that for a positive current into this + + align:start position:0% +that for a positive current into this + + + align:start position:0% +that for a positive current into this +I'm going to get an induced voltage this + + align:start position:0% +I'm going to get an induced voltage this + + + align:start position:0% +I'm going to get an induced voltage this +way for the D Lambda + + align:start position:0% +way for the D Lambda + + + align:start position:0% +way for the D Lambda +DT okay so it basically comes back to + + align:start position:0% +DT okay so it basically comes back to + + + align:start position:0% +DT okay so it basically comes back to +lens's + + align:start position:0% +lens's + + + align:start position:0% +lens's +law excellent question any other + + align:start position:0% +law excellent question any other + + + align:start position:0% +law excellent question any other +questions and we'll see how that plays + + align:start position:0% +questions and we'll see how that plays + + + align:start position:0% +questions and we'll see how that plays +out in the the systems we're going to + + align:start position:0% + + + + align:start position:0% + +create okay so that gives me inductance + + align:start position:0% +create okay so that gives me inductance + + + align:start position:0% +create okay so that gives me inductance +let me point out just a couple little + + align:start position:0% +let me point out just a couple little + + + align:start position:0% +let me point out just a couple little +things about inductance the first thing + + align:start position:0% +things about inductance the first thing + + + align:start position:0% +things about inductance the first thing +I'll note is notice that inductance is + + align:start position:0% +I'll note is notice that inductance is + + + align:start position:0% +I'll note is notice that inductance is +not proportional to the number of terms + + align:start position:0% +not proportional to the number of terms + + + align:start position:0% +not proportional to the number of terms +but it's proportional to the number of + + align:start position:0% +but it's proportional to the number of + + + align:start position:0% +but it's proportional to the number of +turns + + align:start position:0% +turns + + + align:start position:0% +turns +squared Why is that because the H field + + align:start position:0% +squared Why is that because the H field + + + align:start position:0% +squared Why is that because the H field +I induce I get n * I so there's a factor + + align:start position:0% +I induce I get n * I so there's a factor + + + align:start position:0% +I induce I get n * I so there's a factor +of n there and then the flux that gets + + align:start position:0% +of n there and then the flux that gets + + + align:start position:0% +of n there and then the flux that gets +linked the flux linkage has another + + align:start position:0% +linked the flux linkage has another + + + align:start position:0% +linked the flux linkage has another +factor of n so there's an N squared in + + align:start position:0% +factor of n so there's an N squared in + + + align:start position:0% +factor of n so there's an N squared in +the inductance okay so if I double the + + align:start position:0% +the inductance okay so if I double the + + + align:start position:0% +the inductance okay so if I double the +number of terms I don't double the + + align:start position:0% +number of terms I don't double the + + + align:start position:0% +number of terms I don't double the +inductance I quadruple it all right um + + align:start position:0% +inductance I quadruple it all right um + + + align:start position:0% +inductance I quadruple it all right um +and in fact a lot of Manufacturers when + + align:start position:0% +and in fact a lot of Manufacturers when + + + align:start position:0% +and in fact a lot of Manufacturers when +they give you a core will tell you the + + align:start position:0% +they give you a core will tell you the + + + align:start position:0% +they give you a core will tell you the +inductance of one turn they give you + + align:start position:0% +inductance of one turn they give you + + + align:start position:0% +inductance of one turn they give you +something that's often called the a as + + align:start position:0% +something that's often called the a as + + + align:start position:0% +something that's often called the a as +subel value or the specific inductance + + align:start position:0% +subel value or the specific inductance + + + align:start position:0% +subel value or the specific inductance +right so it's sort of the nanah henries + + align:start position:0% +right so it's sort of the nanah henries + + + align:start position:0% +right so it's sort of the nanah henries +for one turn right and if you want the L + + align:start position:0% +for one turn right and if you want the L + + + align:start position:0% +for one turn right and if you want the L +for your inductor it's equal to n^2 a + + align:start position:0% +for your inductor it's equal to n^2 a + + + align:start position:0% +for your inductor it's equal to n^2 a +sub L right so you know if as ofl is you + + align:start position:0% +sub L right so you know if as ofl is you + + + align:start position:0% +sub L right so you know if as ofl is you +know 100 n henries per turn you've got + + align:start position:0% +know 100 n henries per turn you've got + + + align:start position:0% +know 100 n henries per turn you've got +to multiply 100 n henries at one turn + + align:start position:0% +to multiply 100 n henries at one turn + + + align:start position:0% +to multiply 100 n henries at one turn +you've got to multiply it by the square + + align:start position:0% +you've got to multiply it by the square + + + align:start position:0% +you've got to multiply it by the square +of the number of turns not the number of + + align:start position:0% +of the number of turns not the number of + + + align:start position:0% +of the number of turns not the number of +turns + + align:start position:0% +turns + + + align:start position:0% +turns +okay the other thing I'll note here is + + align:start position:0% +okay the other thing I'll note here is + + + align:start position:0% +okay the other thing I'll note here is +that notice that the inductance here is + + align:start position:0% +that notice that the inductance here is + + + align:start position:0% +that notice that the inductance here is +proportional to the permeability of the + + align:start position:0% +proportional to the permeability of the + + + align:start position:0% +proportional to the permeability of the +core right and we kind of made the + + align:start position:0% +core right and we kind of made the + + + align:start position:0% +core right and we kind of made the +approximation at the beginning the + + align:start position:0% +approximation at the beginning the + + + align:start position:0% +approximation at the beginning the +permeability of core is large compared + + align:start position:0% +permeability of core is large compared + + + align:start position:0% +permeability of core is large compared +to m in order to sort of make this + + align:start position:0% +to m in order to sort of make this + + + align:start position:0% +to m in order to sort of make this +simplified calculation work + + align:start position:0% +simplified calculation work + + + align:start position:0% +simplified calculation work +um the problem with having a high + + align:start position:0% +um the problem with having a high + + + align:start position:0% +um the problem with having a high +permeability and that could be a + + align:start position:0% +permeability and that could be a + + + align:start position:0% +permeability and that could be a +thousand or more um is that it's not a + + align:start position:0% +thousand or more um is that it's not a + + + align:start position:0% +thousand or more um is that it's not a +very stable number right it could be + + align:start position:0% +very stable number right it could be + + + align:start position:0% +very stable number right it could be +plus or minus 20 + + align:start position:0% +plus or minus 20 + + + align:start position:0% +plus or minus 20 +5% even in the ideal case for a lot of + + align:start position:0% +5% even in the ideal case for a lot of + + + align:start position:0% +5% even in the ideal case for a lot of +core materials and that's before you + + align:start position:0% +core materials and that's before you + + + align:start position:0% +core materials and that's before you +talk about temperature or flux or + + align:start position:0% +talk about temperature or flux or + + + align:start position:0% +talk about temperature or flux or +anything else going changing right so + + align:start position:0% +anything else going changing right so + + + align:start position:0% +anything else going changing right so +this is not a great way to make a very + + align:start position:0% +this is not a great way to make a very + + + align:start position:0% +this is not a great way to make a very +stable valued + + align:start position:0% +stable valued + + + align:start position:0% +stable valued +inductance um so we might want to think + + align:start position:0% +inductance um so we might want to think + + + align:start position:0% +inductance um so we might want to think +about how do we deal with the + + align:start position:0% +about how do we deal with the + + + align:start position:0% +about how do we deal with the +variability that often turns up in the + + align:start position:0% +variability that often turns up in the + + + align:start position:0% +variability that often turns up in the +permeability of core materials when we + + align:start position:0% +permeability of core materials when we + + + align:start position:0% +permeability of core materials when we +design inductors okay and we we'll see + + align:start position:0% +design inductors okay and we we'll see + + + align:start position:0% +design inductors okay and we we'll see +that any questions + + align:start position:0% + + + + align:start position:0% + +okay now before I jump into how do we do + + align:start position:0% +okay now before I jump into how do we do + + + align:start position:0% +okay now before I jump into how do we do +this quicker than writing Maxwell's + + align:start position:0% +this quicker than writing Maxwell's + + + align:start position:0% +this quicker than writing Maxwell's +equations let's consider one more + + align:start position:0% +equations let's consider one more + + + align:start position:0% +equations let's consider one more +example and what I'd like to consider + + align:start position:0% +example and what I'd like to consider + + + align:start position:0% +example and what I'd like to consider +now is an example with a gap in the core + + align:start position:0% +now is an example with a gap in the core + + + align:start position:0% +now is an example with a gap in the core +okay so I'm going to have I'll draw it + + align:start position:0% +okay so I'm going to have I'll draw it + + + align:start position:0% +okay so I'm going to have I'll draw it +as a C Core this time just you mean it + + align:start position:0% +as a C Core this time just you mean it + + + align:start position:0% +as a C Core this time just you mean it +doesn't have much to do with the actual + + align:start position:0% +doesn't have much to do with the actual + + + align:start position:0% +doesn't have much to do with the actual +shape of the core + + align:start position:0% +shape of the core + + + align:start position:0% +shape of the core +okay so here's my core + + align:start position:0% + + + + align:start position:0% + +okay so I'm going to + + align:start position:0% +okay so I'm going to + + + align:start position:0% +okay so I'm going to +put n turns on this + + align:start position:0% + + + + align:start position:0% + +core I'm going to put a current I in + + align:start position:0% +core I'm going to put a current I in + + + align:start position:0% +core I'm going to put a current I in +here again I'm going to assume that this + + align:start position:0% +here again I'm going to assume that this + + + align:start position:0% +here again I'm going to assume that this +core the actual core section has a + + align:start position:0% +core the actual core section has a + + + align:start position:0% +core the actual core section has a +length of + + align:start position:0% +length of + + + align:start position:0% +length of +core and a cross-sectional area core and + + align:start position:0% +core and a cross-sectional area core and + + + align:start position:0% +core and a cross-sectional area core and +a permeability of the core which again + + align:start position:0% +a permeability of the core which again + + + align:start position:0% +a permeability of the core which again +I'm going to assume it's very + + align:start position:0% +I'm going to assume it's very + + + align:start position:0% +I'm going to assume it's very +high then I'm going to have some Gap + + align:start position:0% +high then I'm going to have some Gap + + + align:start position:0% +high then I'm going to have some Gap +here and maybe that Gap has nothing in + + align:start position:0% +here and maybe that Gap has nothing in + + + align:start position:0% +here and maybe that Gap has nothing in +it maybe it's just air it's a per + + align:start position:0% +it maybe it's just air it's a per + + + align:start position:0% +it maybe it's just air it's a per +permeability of free space right so + + align:start position:0% +permeability of free space right so + + + align:start position:0% +permeability of free space right so +maybe I'll assume that this is the area + + align:start position:0% +maybe I'll assume that this is the area + + + align:start position:0% +maybe I'll assume that this is the area +of the Gap you know this spacing which + + align:start position:0% +of the Gap you know this spacing which + + + align:start position:0% +of the Gap you know this spacing which +might be the treated the same as the + + align:start position:0% +might be the treated the same as the + + + align:start position:0% +might be the treated the same as the +area of the core it has a permeability + + align:start position:0% +area of the core it has a permeability + + + align:start position:0% +area of the core it has a permeability +which might be the permeability of free + + align:start position:0% +which might be the permeability of free + + + align:start position:0% +which might be the permeability of free +space and something that's the length of + + align:start position:0% +space and something that's the length of + + + align:start position:0% +space and something that's the length of +the Gap all right just this is the + + align:start position:0% +the Gap all right just this is the + + + align:start position:0% +the Gap all right just this is the +length of the Gap here LG okay everybody + + align:start position:0% +length of the Gap here LG okay everybody + + + align:start position:0% +length of the Gap here LG okay everybody +see that + + align:start position:0% +see that + + + align:start position:0% +see that +setup so how would I analyze this + + align:start position:0% +setup so how would I analyze this + + + align:start position:0% +setup so how would I analyze this +structure okay well I would follow the + + align:start position:0% +structure okay well I would follow the + + + align:start position:0% +structure okay well I would follow the +same exact pattern + + align:start position:0% +same exact pattern + + + align:start position:0% +same exact pattern +okay except that because I have part of + + align:start position:0% +okay except that because I have part of + + + align:start position:0% +okay except that because I have part of +this structure has high permeability and + + align:start position:0% +this structure has high permeability and + + + align:start position:0% +this structure has high permeability and +heart of part of it has low + + align:start position:0% +heart of part of it has low + + + align:start position:0% +heart of part of it has low +permeability um finding the H field is a + + align:start position:0% +permeability um finding the H field is a + + + align:start position:0% +permeability um finding the H field is a +little bit trickier or or finding the + + align:start position:0% +little bit trickier or or finding the + + + align:start position:0% +little bit trickier or or finding the +flux is a little bit trickier so if I + + align:start position:0% +flux is a little bit trickier so if I + + + align:start position:0% +flux is a little bit trickier so if I +were to follow my first step with Amper + + align:start position:0% +were to follow my first step with Amper + + + align:start position:0% +were to follow my first step with Amper +law right what I'm going to do is I'm + + align:start position:0% +law right what I'm going to do is I'm + + + align:start position:0% +law right what I'm going to do is I'm +going to get the integral of h. + + align:start position:0% +going to get the integral of h. + + + align:start position:0% +going to get the integral of h. +DL is going to be the H in the + + align:start position:0% +DL is going to be the H in the + + + align:start position:0% +DL is going to be the H in the +core times the length of the core plus + + align:start position:0% +core times the length of the core plus + + + align:start position:0% +core times the length of the core plus +the H in the Gap times the length of the + + align:start position:0% +the H in the Gap times the length of the + + + align:start position:0% +the H in the Gap times the length of the +Gap okay and that's going to be equal to + + align:start position:0% + + + + align:start position:0% + +ni okay all + + align:start position:0% +ni okay all + + + align:start position:0% +ni okay all +right the question is you know how do I + + align:start position:0% +right the question is you know how do I + + + align:start position:0% +right the question is you know how do I +deal with the H and the core and the in + + align:start position:0% +deal with the H and the core and the in + + + align:start position:0% +deal with the H and the core and the in +the gap or how are they + + align:start position:0% +the gap or how are they + + + align:start position:0% +the gap or how are they +related okay where we get that is we + + align:start position:0% +related okay where we get that is we + + + align:start position:0% +related okay where we get that is we +come + + align:start position:0% +come + + + align:start position:0% +come +back to flux + + align:start position:0% +back to flux + + + align:start position:0% +back to flux +continuity right flux is neither created + + align:start position:0% +continuity right flux is neither created + + + align:start position:0% +continuity right flux is neither created +nor + + align:start position:0% +nor + + + align:start position:0% +nor +destroyed okay there's no magnetic + + align:start position:0% +destroyed okay there's no magnetic + + + align:start position:0% +destroyed okay there's no magnetic +charge so that means whatever flux here + + align:start position:0% +charge so that means whatever flux here + + + align:start position:0% +charge so that means whatever flux here +comes out of the + + align:start position:0% +comes out of the + + + align:start position:0% +comes out of the +core whatever flux enters a little pill + + align:start position:0% +core whatever flux enters a little pill + + + align:start position:0% +core whatever flux enters a little pill +box at the edge of this core must also + + align:start position:0% +box at the edge of this core must also + + + align:start position:0% +box at the edge of this core must also +pop out out the other side into the Gap + + align:start position:0% +pop out out the other side into the Gap + + + align:start position:0% +pop out out the other side into the Gap +right so what that rough Le means is + + align:start position:0% +right so what that rough Le means is + + + align:start position:0% +right so what that rough Le means is +that the the b in the core times the + + align:start position:0% +that the the b in the core times the + + + align:start position:0% +that the the b in the core times the +area of the core must equal the b in the + + align:start position:0% +area of the core must equal the b in the + + + align:start position:0% +area of the core must equal the b in the +Gap times the area of the + + align:start position:0% +Gap times the area of the + + + align:start position:0% +Gap times the area of the +Gap okay and if I then assume let me + + align:start position:0% +Gap okay and if I then assume let me + + + align:start position:0% +Gap okay and if I then assume let me +just assume for sake of argument that + + align:start position:0% +just assume for sake of argument that + + + align:start position:0% +just assume for sake of argument that +the way this flux goes I'm just going to + + align:start position:0% +the way this flux goes I'm just going to + + + align:start position:0% +the way this flux goes I'm just going to +treat the area of the core and the area + + align:start position:0% +treat the area of the core and the area + + + align:start position:0% +treat the area of the core and the area +of the + + align:start position:0% +of the + + + align:start position:0% +of the +Gap the same okay so then I can just say + + align:start position:0% +Gap the same okay so then I can just say + + + align:start position:0% +Gap the same okay so then I can just say +okay if AC equals + + align:start position:0% +okay if AC equals + + + align:start position:0% +okay if AC equals +AG then that means the b in the core is + + align:start position:0% +AG then that means the b in the core is + + + align:start position:0% +AG then that means the b in the core is +equal to the a + + align:start position:0% +equal to the a + + + align:start position:0% +equal to the a +of B in the core is equal to the b in + + align:start position:0% +of B in the core is equal to the b in + + + align:start position:0% +of B in the core is equal to the b in +the + + align:start position:0% +the + + + align:start position:0% +the +Gap okay um actually I don't even have + + align:start position:0% +Gap okay um actually I don't even have + + + align:start position:0% +Gap okay um actually I don't even have +to make that approximation let's just + + align:start position:0% +to make that approximation let's just + + + align:start position:0% +to make that approximation let's just +leave it like + + align:start position:0% +leave it like + + + align:start position:0% +leave it like +this actually it's even better if I + + align:start position:0% +this actually it's even better if I + + + align:start position:0% +this actually it's even better if I +leave it like this okay the B and the + + align:start position:0% +leave it like this okay the B and the + + + align:start position:0% +leave it like this okay the B and the +core times the area the core is equal to + + align:start position:0% +core times the area the core is equal to + + + align:start position:0% +core times the area the core is equal to +B in the Gap times the area of the gap + + align:start position:0% +B in the Gap times the area of the gap + + + align:start position:0% +B in the Gap times the area of the gap +which is + + align:start position:0% +which is + + + align:start position:0% +which is +also equal to the total + + align:start position:0% +also equal to the total + + + align:start position:0% +also equal to the total +flux you if there's some flux running + + align:start position:0% +flux you if there's some flux running + + + align:start position:0% +flux you if there's some flux running +around this Loop it looks like this + + align:start position:0% +around this Loop it looks like this + + + align:start position:0% +around this Loop it looks like this +here's the total flux that's traveling + + align:start position:0% +here's the total flux that's traveling + + + align:start position:0% +here's the total flux that's traveling +around this Loop right and so all I'm + + align:start position:0% +around this Loop right and so all I'm + + + align:start position:0% +around this Loop right and so all I'm +saying is whatever flux is coming down + + align:start position:0% +saying is whatever flux is coming down + + + align:start position:0% +saying is whatever flux is coming down +this pipe in the core is jumping out + + align:start position:0% +this pipe in the core is jumping out + + + align:start position:0% +this pipe in the core is jumping out +into the Gap + + align:start position:0% +into the Gap + + + align:start position:0% +into the Gap +right so I can say that each of these is + + align:start position:0% +right so I can say that each of these is + + + align:start position:0% +right so I can say that each of these is +equal to the + + align:start position:0% +equal to the + + + align:start position:0% +equal to the +flux okay okay in the + + align:start position:0% +flux okay okay in the + + + align:start position:0% +flux okay okay in the +core all right so then I maybe I can + + align:start position:0% +core all right so then I maybe I can + + + align:start position:0% +core all right so then I maybe I can +write this as uh mu core H + + align:start position:0% +write this as uh mu core H + + + align:start position:0% +write this as uh mu core H +core time a core is equal to Mu Gap or + + align:start position:0% +core time a core is equal to Mu Gap or + + + align:start position:0% +core time a core is equal to Mu Gap or +mu KN time H in the Gap time the area of + + align:start position:0% +mu KN time H in the Gap time the area of + + + align:start position:0% +mu KN time H in the Gap time the area of +the Gap is equal to five in the core + + align:start position:0% +the Gap is equal to five in the core + + + align:start position:0% +the Gap is equal to five in the core +okay so I could then say Okay + + align:start position:0% +okay so I could then say Okay + + + align:start position:0% +okay so I could then say Okay +HC is equal to F in the core divided by + + align:start position:0% +HC is equal to F in the core divided by + + + align:start position:0% +HC is equal to F in the core divided by +muc AC and H in the Gap is equal to the + + align:start position:0% +muc AC and H in the Gap is equal to the + + + align:start position:0% +muc AC and H in the Gap is equal to the +flux in the core / + + align:start position:0% +flux in the core / + + + align:start position:0% +flux in the core / +mu mu area of the + + align:start position:0% +mu mu area of the + + + align:start position:0% +mu mu area of the +Gap okay so now let me just go + + align:start position:0% +Gap okay so now let me just go + + + align:start position:0% +Gap okay so now let me just go +substitute that in + + align:start position:0% +substitute that in + + + align:start position:0% +substitute that in +here okay and what am I going to get I'm + + align:start position:0% +here okay and what am I going to get I'm + + + align:start position:0% +here okay and what am I going to get I'm +going to get HC which is this so I'm + + align:start position:0% +going to get HC which is this so I'm + + + align:start position:0% +going to get HC which is this so I'm +going to get 5 C I'm just I'll just call + + align:start position:0% +going to get 5 C I'm just I'll just call + + + align:start position:0% +going to get 5 C I'm just I'll just call +it f I'll call it f c f c times + + align:start position:0% +it f I'll call it f c f c times + + + align:start position:0% +it f I'll call it f c f c times +LC over + + align:start position:0% + + + + align:start position:0% + +mcac + + align:start position:0% +mcac + + + align:start position:0% +mcac +plus 5 c times + + align:start position:0% + + + + align:start position:0% + +um LG over mu + + align:start position:0% +um LG over mu + + + align:start position:0% +um LG over mu +AG is equal to + + align:start position:0% + + + + align:start position:0% + +ni okay so let's use that + + align:start position:0% +ni okay so let's use that + + + align:start position:0% +ni okay so let's use that +so now what I'm going to + + align:start position:0% +so now what I'm going to + + + align:start position:0% +so now what I'm going to +get is the + + align:start position:0% +get is the + + + align:start position:0% +get is the +following I can write F in the core is + + align:start position:0% +following I can write F in the core is + + + align:start position:0% +following I can write F in the core is +simply equal to uh + + align:start position:0% +simply equal to uh + + + align:start position:0% +simply equal to uh +ni divided by this bracketed + + align:start position:0% +ni divided by this bracketed + + + align:start position:0% +ni divided by this bracketed +expression LC over muc AC plus LG over + + align:start position:0% +expression LC over muc AC plus LG over + + + align:start position:0% +expression LC over muc AC plus LG over +mu + + align:start position:0% +mu + + + align:start position:0% +mu +AG + + align:start position:0% +AG + + + align:start position:0% +AG +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and then I can just say okay that's fine + + align:start position:0% +and then I can just say okay that's fine + + + align:start position:0% +and then I can just say okay that's fine +that means the flux linkage Lambda is + + align:start position:0% +that means the flux linkage Lambda is + + + align:start position:0% +that means the flux linkage Lambda is +simply n * the flux in the core + + align:start position:0% +simply n * the flux in the core + + + align:start position:0% +simply n * the flux in the core +right and that's going to be + + align:start position:0% +right and that's going to be + + + align:start position:0% +right and that's going to be +N2 divided + + align:start position:0% +N2 divided + + + align:start position:0% +N2 divided +by + + align:start position:0% +by + + + align:start position:0% +by +uh + + align:start position:0% +uh + + + align:start position:0% +uh +LC over muc + + align:start position:0% +LC over muc + + + align:start position:0% +LC over muc +a plus LG over mu + + align:start position:0% +a plus LG over mu + + + align:start position:0% +a plus LG over mu +a uh time I and this thing again + + align:start position:0% +a uh time I and this thing again + + + align:start position:0% +a uh time I and this thing again +okay is what we call inductance + + align:start position:0% +okay is what we call inductance + + + align:start position:0% +okay is what we call inductance +L any questions about + + align:start position:0% + + + + align:start position:0% + +that so we've again used Maxwell's + + align:start position:0% +that so we've again used Maxwell's + + + align:start position:0% +that so we've again used Maxwell's +equations to come up with the inductance + + align:start position:0% +equations to come up with the inductance + + + align:start position:0% +equations to come up with the inductance +of our structure okay point out a couple + + align:start position:0% +of our structure okay point out a couple + + + align:start position:0% +of our structure okay point out a couple +of things about + + align:start position:0% +of things about + + + align:start position:0% +of things about +this um + + align:start position:0% +this um + + + align:start position:0% +this um +suppose + + align:start position:0% +suppose + + + align:start position:0% +suppose +um if as long as I have uh if if I have + + align:start position:0% +um if as long as I have uh if if I have + + + align:start position:0% +um if as long as I have uh if if I have +AC is on the same scale as AG in other + + align:start position:0% +AC is on the same scale as AG in other + + + align:start position:0% +AC is on the same scale as AG in other +words the Gap area and the core area + + align:start position:0% +words the Gap area and the core area + + + align:start position:0% +words the Gap area and the core area +about the same thing as if uh uh + + align:start position:0% +about the same thing as if uh uh + + + align:start position:0% +about the same thing as if uh uh +LG over mu over mu is much greater than + + align:start position:0% +LG over mu over mu is much greater than + + + align:start position:0% +LG over mu over mu is much greater than +um L core over mu core and remember that + + align:start position:0% +um L core over mu core and remember that + + + align:start position:0% +um L core over mu core and remember that +mu core I'm assuming a very high + + align:start position:0% +mu core I'm assuming a very high + + + align:start position:0% +mu core I'm assuming a very high +permeability relative to mu and if it's + + align:start position:0% +permeability relative to mu and if it's + + + align:start position:0% +permeability relative to mu and if it's +much higher than the length of the Gap + + align:start position:0% +much higher than the length of the Gap + + + align:start position:0% +much higher than the length of the Gap +then what I get is L is approximately + + align:start position:0% +then what I get is L is approximately + + + align:start position:0% +then what I get is L is approximately +equal to n^2 over LG over mu + + align:start position:0% +equal to n^2 over LG over mu + + + align:start position:0% +equal to n^2 over LG over mu +AG okay in other words this term no + + align:start position:0% +AG okay in other words this term no + + + align:start position:0% +AG okay in other words this term no +longer + + align:start position:0% +longer + + + align:start position:0% +longer +matters and then I get an inductance + + align:start position:0% +matters and then I get an inductance + + + align:start position:0% +matters and then I get an inductance +that doesn't really depend upon the + + align:start position:0% +that doesn't really depend upon the + + + align:start position:0% +that doesn't really depend upon the +exact value of the core + + align:start position:0% +exact value of the core + + + align:start position:0% +exact value of the core +permeability because it's dominated by + + align:start position:0% +permeability because it's dominated by + + + align:start position:0% +permeability because it's dominated by +this term okay so I'm setting my + + align:start position:0% +this term okay so I'm setting my + + + align:start position:0% +this term okay so I'm setting my +inductance based on Geometry say based + + align:start position:0% +inductance based on Geometry say based + + + align:start position:0% +inductance based on Geometry say based +on the area length of the Gap rather + + align:start position:0% +on the area length of the Gap rather + + + align:start position:0% +on the area length of the Gap rather +than any material parameter and that + + align:start position:0% +than any material parameter and that + + + align:start position:0% +than any material parameter and that +could be a very desirable thing because + + align:start position:0% +could be a very desirable thing because + + + align:start position:0% +could be a very desirable thing because +now some variation doesn't matter + + align:start position:0% +now some variation doesn't matter + + + align:start position:0% +now some variation doesn't matter +anymore any questions about + + align:start position:0% + + + + align:start position:0% + +that what does that mean as a practical + + align:start position:0% +that what does that mean as a practical + + + align:start position:0% +that what does that mean as a practical +matter if I do this if I get into this + + align:start position:0% +matter if I do this if I get into this + + + align:start position:0% +matter if I do this if I get into this +situation what I'm really + + align:start position:0% +situation what I'm really + + + align:start position:0% +situation what I'm really +saying is that the magnetic energy + + align:start position:0% +saying is that the magnetic energy + + + align:start position:0% +saying is that the magnetic energy +stored right I get an energy storage of + + align:start position:0% +stored right I get an energy storage of + + + align:start position:0% +stored right I get an energy storage of +12 Li s + + align:start position:0% +12 Li s + + + align:start position:0% +12 Li s +right that we we all know the the energy + + align:start position:0% +right that we we all know the the energy + + + align:start position:0% +right that we we all know the the energy +stored in inductor or linear inductor is + + align:start position:0% +stored in inductor or linear inductor is + + + align:start position:0% +stored in inductor or linear inductor is +l s right where is that energy stored + + align:start position:0% +l s right where is that energy stored + + + align:start position:0% +l s right where is that energy stored +it's stored in the magnetic + + align:start position:0% +it's stored in the magnetic + + + align:start position:0% +it's stored in the magnetic +fields + + align:start position:0% +fields + + + align:start position:0% +fields +right um but where in this structure is + + align:start position:0% +right um but where in this structure is + + + align:start position:0% +right um but where in this structure is +the energy stored well the magnetic + + align:start position:0% +the energy stored well the magnetic + + + align:start position:0% +the energy stored well the magnetic +energy storage density is equal + + align:start position:0% +energy storage density is equal + + + align:start position:0% +energy storage density is equal +to2 um or actually the total magnetic + + align:start position:0% +to2 um or actually the total magnetic + + + align:start position:0% +to2 um or actually the total magnetic +energy stored is going to be2 the + + align:start position:0% +energy stored is going to be2 the + + + align:start position:0% +energy stored is going to be2 the +integral over the volume B Doh + + align:start position:0% +integral over the volume B Doh + + + align:start position:0% +integral over the volume B Doh +DV okay in other + + align:start position:0% +DV okay in other + + + align:start position:0% +DV okay in other +words it's the product of the B&H Fields + + align:start position:0% +words it's the product of the B&H Fields + + + align:start position:0% +words it's the product of the B&H Fields +integrated gives me the total energy + + align:start position:0% +integrated gives me the total energy + + + align:start position:0% +integrated gives me the total energy +stored okay now if the area of the core + + align:start position:0% +stored okay now if the area of the core + + + align:start position:0% +stored okay now if the area of the core +and the area of the + + align:start position:0% +and the area of the + + + align:start position:0% +and the area of the +Gap are the + + align:start position:0% +Gap are the + + + align:start position:0% +Gap are the +same right we know that the b in the + + align:start position:0% +same right we know that the b in the + + + align:start position:0% +same right we know that the b in the +core and the b in the Gap are the + + align:start position:0% +core and the b in the Gap are the + + + align:start position:0% +core and the b in the Gap are the +same right but the + + align:start position:0% +same right but the + + + align:start position:0% +same right but the +H is B over + + align:start position:0% +H is B over + + + align:start position:0% +H is B over +mu and and that means that the H field + + align:start position:0% +mu and and that means that the H field + + + align:start position:0% +mu and and that means that the H field +in the core is going to be really small + + align:start position:0% +in the core is going to be really small + + + align:start position:0% +in the core is going to be really small +compared to the H field in the + + align:start position:0% +compared to the H field in the + + + align:start position:0% +compared to the H field in the +Gap okay so the flux is sort of + + align:start position:0% +Gap okay so the flux is sort of + + + align:start position:0% +Gap okay so the flux is sort of +continuous it doesn't change as you're + + align:start position:0% +continuous it doesn't change as you're + + + align:start position:0% +continuous it doesn't change as you're +going around okay the flux density but + + align:start position:0% +going around okay the flux density but + + + align:start position:0% +going around okay the flux density but +the magnetic field strength does change + + align:start position:0% +the magnetic field strength does change + + + align:start position:0% +the magnetic field strength does change +and what that means is you'll have very + + align:start position:0% +and what that means is you'll have very + + + align:start position:0% +and what that means is you'll have very +high magnetic field strength in the + + align:start position:0% +high magnetic field strength in the + + + align:start position:0% +high magnetic field strength in the +Gap so if I'm drawing my magnetic field + + align:start position:0% +Gap so if I'm drawing my magnetic field + + + align:start position:0% +Gap so if I'm drawing my magnetic field +H I'll have a lot of field in the gap + + align:start position:0% +H I'll have a lot of field in the gap + + + align:start position:0% +H I'll have a lot of field in the gap +and very little in the + + align:start position:0% +and very little in the + + + align:start position:0% +and very little in the +core okay and as a consequence all the + + align:start position:0% +core okay and as a consequence all the + + + align:start position:0% +core okay and as a consequence all the +energies actually or the dominant + + align:start position:0% +energies actually or the dominant + + + align:start position:0% +energies actually or the dominant +portion of the energy is stored in the + + align:start position:0% +portion of the energy is stored in the + + + align:start position:0% +portion of the energy is stored in the +Gap and that's why I sort of don't care + + align:start position:0% +Gap and that's why I sort of don't care + + + align:start position:0% +Gap and that's why I sort of don't care +about what the core is doing because all + + align:start position:0% +about what the core is doing because all + + + align:start position:0% +about what the core is doing because all +the energy is stored here if I've met + + align:start position:0% +the energy is stored here if I've met + + + align:start position:0% +the energy is stored here if I've met +that approximation so we often do that + + align:start position:0% +that approximation so we often do that + + + align:start position:0% +that approximation so we often do that +put a gap in it firstly because it makes + + align:start position:0% +put a gap in it firstly because it makes + + + align:start position:0% +put a gap in it firstly because it makes +us insensitive to the actual material + + align:start position:0% +us insensitive to the actual material + + + align:start position:0% +us insensitive to the actual material +parameters which can vary a lot and B is + + align:start position:0% +parameters which can vary a lot and B is + + + align:start position:0% +parameters which can vary a lot and B is +it turns out because the limitations on + + align:start position:0% +it turns out because the limitations on + + + align:start position:0% +it turns out because the limitations on +on how much flux you can have uh you can + + align:start position:0% +on how much flux you can have uh you can + + + align:start position:0% +on how much flux you can have uh you can +get a lot more energy storage if you put + + align:start position:0% +get a lot more energy storage if you put + + + align:start position:0% +get a lot more energy storage if you put +a gap in the + + align:start position:0% +a gap in the + + + align:start position:0% +a gap in the +core okay and what we're really doing is + + align:start position:0% +core okay and what we're really doing is + + + align:start position:0% +core okay and what we're really doing is +we're kind of focusing the magnetic + + align:start position:0% +we're kind of focusing the magnetic + + + align:start position:0% +we're kind of focusing the magnetic +field down into this space and storing + + align:start position:0% +field down into this space and storing + + + align:start position:0% +field down into this space and storing +the energy + + align:start position:0% + + + + align:start position:0% + +here any questions about + + align:start position:0% + + + + align:start position:0% + +that now as you might + + align:start position:0% +that now as you might + + + align:start position:0% +that now as you might +imagine you know we can do these + + align:start position:0% +imagine you know we can do these + + + align:start position:0% +imagine you know we can do these +calculations and use Maxwell's equations + + align:start position:0% +calculations and use Maxwell's equations + + + align:start position:0% +calculations and use Maxwell's equations +and get to all these results and that's + + align:start position:0% +and get to all these results and that's + + + align:start position:0% +and get to all these results and that's +great but it's kind of + + align:start position:0% +great but it's kind of + + + align:start position:0% +great but it's kind of +tedious right it would be nice if there + + align:start position:0% +tedious right it would be nice if there + + + align:start position:0% +tedious right it would be nice if there +was a much faster way to do these + + align:start position:0% +was a much faster way to do these + + + align:start position:0% +was a much faster way to do these +calculations both to figure out things + + align:start position:0% +calculations both to figure out things + + + align:start position:0% +calculations both to figure out things +like inductances but also to figure out + + align:start position:0% +like inductances but also to figure out + + + align:start position:0% +like inductances but also to figure out +what are the magnetic fluxes here and + + align:start position:0% +what are the magnetic fluxes here and + + + align:start position:0% +what are the magnetic fluxes here and +there right what are the what are the + + align:start position:0% +there right what are the what are the + + + align:start position:0% +there right what are the what are the +flux linkages I get on different + + align:start position:0% +flux linkages I get on different + + + align:start position:0% +flux linkages I get on different +windings I might have a Transformer with + + align:start position:0% +windings I might have a Transformer with + + + align:start position:0% +windings I might have a Transformer with +more than one winding right how can I do + + align:start position:0% +more than one winding right how can I do + + + align:start position:0% +more than one winding right how can I do +that + + align:start position:0% +that + + + align:start position:0% +that +easily and the way we do that is using + + align:start position:0% +easily and the way we do that is using + + + align:start position:0% +easily and the way we do that is using +something called a magnetic circuit + + align:start position:0% +something called a magnetic circuit + + + align:start position:0% +something called a magnetic circuit +model + + align:start position:0% +model + + + align:start position:0% +model +okay + + align:start position:0% + + + + align:start position:0% + +um and here's the + + align:start position:0% +um and here's the + + + align:start position:0% +um and here's the +idea um let me come back to this + + align:start position:0% +idea um let me come back to this + + + align:start position:0% +idea um let me come back to this +equation here + + align:start position:0% + + + + align:start position:0% + +right this sort of looks like the + + align:start position:0% +right this sort of looks like the + + + align:start position:0% +right this sort of looks like the +following roughly speaking this is + + align:start position:0% +following roughly speaking this is + + + align:start position:0% +following roughly speaking this is +equation kind of looks like V is equal + + align:start position:0% +equation kind of looks like V is equal + + + align:start position:0% +equation kind of looks like V is equal +to I'm sorry + + align:start position:0% +to I'm sorry + + + align:start position:0% +to I'm sorry +I is equal to + + align:start position:0% +I is equal to + + + align:start position:0% +I is equal to +V / R1 + + + align:start position:0% + + + + align:start position:0% + +R2 + + align:start position:0% +R2 + + + align:start position:0% +R2 +right if I have a resistance remember if + + align:start position:0% +right if I have a resistance remember if + + + align:start position:0% +right if I have a resistance remember if +I have a resistance of a resistor how do + + align:start position:0% +I have a resistance of a resistor how do + + + align:start position:0% +I have a resistance of a resistor how do +I calculate that it's the length of the + + align:start position:0% +I calculate that it's the length of the + + + align:start position:0% +I calculate that it's the length of the +resistive structure divided by the + + align:start position:0% +resistive structure divided by the + + + align:start position:0% +resistive structure divided by the +cross-sectional area divided by the + + align:start position:0% +cross-sectional area divided by the + + + align:start position:0% +cross-sectional area divided by the +conductivity it's length over + + align:start position:0% +conductivity it's length over + + + align:start position:0% +conductivity it's length over +conductivity time cross-sectional area + + align:start position:0% +conductivity time cross-sectional area + + + align:start position:0% +conductivity time cross-sectional area +that's just the sort of thing here + + align:start position:0% +that's just the sort of thing here + + + align:start position:0% +that's just the sort of thing here +except that instead of having + + align:start position:0% +except that instead of having + + + align:start position:0% +except that instead of having +conductivity I have + + align:start position:0% +conductivity I have + + + align:start position:0% +conductivity I have +permeability all right so this sort of + + align:start position:0% +permeability all right so this sort of + + + align:start position:0% +permeability all right so this sort of +looks like you know I is equal to V over + + align:start position:0% +looks like you know I is equal to V over + + + align:start position:0% +looks like you know I is equal to V over +R1 plus the quantity r1+ + + align:start position:0% +R1 plus the quantity r1+ + + + align:start position:0% +R1 plus the quantity r1+ +R2 and notice that that + + align:start position:0% +R2 and notice that that + + + align:start position:0% +R2 and notice that that +flux is passing through the core and the + + align:start position:0% +flux is passing through the core and the + + + align:start position:0% +flux is passing through the core and the +Gap in series + + align:start position:0% +Gap in series + + + align:start position:0% +Gap in series +so if I thought of flux as kind of like + + align:start position:0% +so if I thought of flux as kind of like + + + align:start position:0% +so if I thought of flux as kind of like +being like a + + align:start position:0% +being like a + + + align:start position:0% +being like a +current maybe I could make an equivalent + + align:start position:0% +current maybe I could make an equivalent + + + align:start position:0% +current maybe I could make an equivalent +circuit model that talks about fluxes + + align:start position:0% +circuit model that talks about fluxes + + + align:start position:0% +circuit model that talks about fluxes +and currents or mmfs as we'll see in a + + align:start position:0% +and currents or mmfs as we'll see in a + + + align:start position:0% +and currents or mmfs as we'll see in a +second um and you use that as a means of + + align:start position:0% +second um and you use that as a means of + + + align:start position:0% +second um and you use that as a means of +quickly calculating + + align:start position:0% +quickly calculating + + + align:start position:0% +quickly calculating +things + + align:start position:0% +things + + + align:start position:0% +things +okay so let's let's take a look at + + align:start position:0% +okay so let's let's take a look at + + + align:start position:0% +okay so let's let's take a look at +that um in our model we're going to + + align:start position:0% +that um in our model we're going to + + + align:start position:0% +that um in our model we're going to +Define + + align:start position:0% + + + + align:start position:0% + +ni quantities of + + align:start position:0% + + + + align:start position:0% + +Ni or maybe I should write this in + + align:start position:0% +Ni or maybe I should write this in + + + align:start position:0% +Ni or maybe I should write this in +yellow as being what's known as a me and + + align:start position:0% +yellow as being what's known as a me and + + + align:start position:0% +yellow as being what's known as a me and +sometimes we use the symbol F script f + + align:start position:0% +sometimes we use the symbol F script f + + + align:start position:0% +sometimes we use the symbol F script f +as being what we call a Magneto mod of + + align:start position:0% + + + + align:start position:0% + +force or + + align:start position:0% +force or + + + align:start position:0% +force or +MMF okay + + align:start position:0% +MMF okay + + + align:start position:0% +MMF okay +in some sense the end turns with I in + + align:start position:0% +in some sense the end turns with I in + + + align:start position:0% +in some sense the end turns with I in +there are are sort of the thing that's + + align:start position:0% +there are are sort of the thing that's + + + align:start position:0% +there are are sort of the thing that's +driving + + align:start position:0% +driving + + + align:start position:0% +driving +flux in the + + align:start position:0% +flux in the + + + align:start position:0% +flux in the +system right no I no flux no turns no + + align:start position:0% +system right no I no flux no turns no + + + align:start position:0% +system right no I no flux no turns no +flux so the thing that's trying to push + + align:start position:0% +flux so the thing that's trying to push + + + align:start position:0% +flux so the thing that's trying to push +flux is this ni it's the Magneto motive + + align:start position:0% +flux is this ni it's the Magneto motive + + + align:start position:0% +flux is this ni it's the Magneto motive +Force this is sort of like our + + align:start position:0% +Force this is sort of like our + + + align:start position:0% +Force this is sort of like our +voltage then I have + + align:start position:0% + + + + align:start position:0% + +flux this is just simply flux right + + align:start position:0% +flux this is just simply flux right + + + align:start position:0% +flux this is just simply flux right +which I'm going to think of some as + + align:start position:0% +which I'm going to think of some as + + + align:start position:0% +which I'm going to think of some as +something as I I've sort of expressed it + + align:start position:0% +something as I I've sort of expressed it + + + align:start position:0% +something as I I've sort of expressed it +is Flowing that's what's going through + + align:start position:0% +is Flowing that's what's going through + + + align:start position:0% +is Flowing that's what's going through +the magnetic + + align:start position:0% +the magnetic + + + align:start position:0% +the magnetic +circuit and then the last thing I'm + + align:start position:0% +circuit and then the last thing I'm + + + align:start position:0% +circuit and then the last thing I'm +going to have is that I'm something I'm + + align:start position:0% +going to have is that I'm something I'm + + + align:start position:0% +going to have is that I'm something I'm +going to call I'm going to use script x + + align:start position:0% +going to call I'm going to use script x + + + align:start position:0% +going to call I'm going to use script x +a reluctance which is LX the length over + + align:start position:0% +a reluctance which is LX the length over + + + align:start position:0% +a reluctance which is LX the length over +mux * ax this I'm going to call it a + + align:start position:0% + + + + align:start position:0% + +reluctance this is sort of like a + + align:start position:0% +reluctance this is sort of like a + + + align:start position:0% +reluctance this is sort of like a +resistance right where + + align:start position:0% +resistance right where + + + align:start position:0% +resistance right where +in some sense mu is sort of conductivity + + align:start position:0% +in some sense mu is sort of conductivity + + + align:start position:0% +in some sense mu is sort of conductivity +for magnetic flux all right because + + align:start position:0% +for magnetic flux all right because + + + align:start position:0% +for magnetic flux all right because +reluctance gets bigger resistance gets + + align:start position:0% +reluctance gets bigger resistance gets + + + align:start position:0% +reluctance gets bigger resistance gets +big when I have higher length of the + + align:start position:0% +big when I have higher length of the + + + align:start position:0% +big when I have higher length of the +structure resistance gets small when I + + align:start position:0% +structure resistance gets small when I + + + align:start position:0% +structure resistance gets small when I +get bigger area of the structure and + + align:start position:0% +get bigger area of the structure and + + + align:start position:0% +get bigger area of the structure and +then there's the conductivity term an + + align:start position:0% +then there's the conductivity term an + + + align:start position:0% +then there's the conductivity term an +electrical resistor here it's resistance + + align:start position:0% +electrical resistor here it's resistance + + + align:start position:0% +electrical resistor here it's resistance +to flux and we we call this a + + align:start position:0% +to flux and we we call this a + + + align:start position:0% +to flux and we we call this a +reluctance okay does that make sense to + + align:start position:0% +reluctance okay does that make sense to + + + align:start position:0% +reluctance okay does that make sense to +everybody + + align:start position:0% +everybody + + + align:start position:0% +everybody +so here's the + + align:start position:0% + + + + align:start position:0% + +idea + + align:start position:0% +idea + + + align:start position:0% +idea +um if I have this + + align:start position:0% + + + + align:start position:0% + +structure where I'm going to + + align:start position:0% + + + + align:start position:0% + +have n and + + align:start position:0% +have n and + + + align:start position:0% +have n and +I and that's going to drive a flux + + align:start position:0% +I and that's going to drive a flux + + + align:start position:0% +I and that's going to drive a flux +around this + + align:start position:0% + + + + align:start position:0% + +Loop the way I would model this is with + + align:start position:0% +Loop the way I would model this is with + + + align:start position:0% +Loop the way I would model this is with +an + + align:start position:0% +an + + + align:start position:0% +an +mnf ni that's what's trying to push flux + + align:start position:0% +mnf ni that's what's trying to push flux + + + align:start position:0% +mnf ni that's what's trying to push flux +through the circuit it has to + + align:start position:0% +through the circuit it has to + + + align:start position:0% +through the circuit it has to +travel through the core and I have a + + align:start position:0% +travel through the core and I have a + + + align:start position:0% +travel through the core and I have a +reluctance of the core which is + + align:start position:0% +reluctance of the core which is + + + align:start position:0% +reluctance of the core which is +L the length of the core over the + + align:start position:0% +L the length of the core over the + + + align:start position:0% +L the length of the core over the +permeability of the core and the area of + + align:start position:0% +permeability of the core and the area of + + + align:start position:0% +permeability of the core and the area of +the core okay then it has to go through + + align:start position:0% +the core okay then it has to go through + + + align:start position:0% +the core okay then it has to go through +the Gap right the flux is going around + + align:start position:0% +the Gap right the flux is going around + + + align:start position:0% +the Gap right the flux is going around +the Gap and I get the reluctance of the + + align:start position:0% +the Gap and I get the reluctance of the + + + align:start position:0% +the Gap and I get the reluctance of the +gap is equal to the length of the Gap + + align:start position:0% +gap is equal to the length of the Gap + + + align:start position:0% +gap is equal to the length of the Gap +over mu/ the area of the Gap okay and + + align:start position:0% +over mu/ the area of the Gap okay and + + + align:start position:0% +over mu/ the area of the Gap okay and +what I'm going to get + + align:start position:0% +what I'm going to get + + + align:start position:0% +what I'm going to get +is Flowing around this Loop is f is + + align:start position:0% +is Flowing around this Loop is f is + + + align:start position:0% +is Flowing around this Loop is f is +flux does that make sense + + align:start position:0% +flux does that make sense + + + align:start position:0% +flux does that make sense +everybody so this is what's known as a + + align:start position:0% +everybody so this is what's known as a + + + align:start position:0% +everybody so this is what's known as a +magnetic circuit + + align:start position:0% +magnetic circuit + + + align:start position:0% +magnetic circuit +model right so if you tell me how much + + align:start position:0% +model right so if you tell me how much + + + align:start position:0% +model right so if you tell me how much +ni and total reluctance is flowing + + align:start position:0% +ni and total reluctance is flowing + + + align:start position:0% +ni and total reluctance is flowing +through I can calculate flux and it + + align:start position:0% +through I can calculate flux and it + + + align:start position:0% +through I can calculate flux and it +turns out exactly into that equation + + align:start position:0% +turns out exactly into that equation + + + align:start position:0% +turns out exactly into that equation +right it's ni divide flux is NI divided + + align:start position:0% +right it's ni divide flux is NI divided + + + align:start position:0% +right it's ni divide flux is NI divided +by the sum of the reluctance of the core + + align:start position:0% +by the sum of the reluctance of the core + + + align:start position:0% +by the sum of the reluctance of the core +and the reluctance of the Gap it's + + align:start position:0% +and the reluctance of the Gap it's + + + align:start position:0% +and the reluctance of the Gap it's +exactly that equation everything else + + align:start position:0% +exactly that equation everything else + + + align:start position:0% +exactly that equation everything else +fell out from + + align:start position:0% +fell out from + + + align:start position:0% +fell out from +it does that make sense + + align:start position:0% +it does that make sense + + + align:start position:0% +it does that make sense +everybody so to the extent that we can + + align:start position:0% +everybody so to the extent that we can + + + align:start position:0% +everybody so to the extent that we can +break our structures into pieces of sort + + align:start position:0% +break our structures into pieces of sort + + + align:start position:0% +break our structures into pieces of sort +of flux pipe if you will that are high + + align:start position:0% +of flux pipe if you will that are high + + + align:start position:0% +of flux pipe if you will that are high +permeability they're sort of like our + + align:start position:0% +permeability they're sort of like our + + + align:start position:0% +permeability they're sort of like our +our wires if you will they may have some + + align:start position:0% +our wires if you will they may have some + + + align:start position:0% +our wires if you will they may have some +resistance but they're like our wires + + align:start position:0% +resistance but they're like our wires + + + align:start position:0% +resistance but they're like our wires +and then some low or high reluctance low + + align:start position:0% +and then some low or high reluctance low + + + align:start position:0% +and then some low or high reluctance low +permeability regions which flux is being + + align:start position:0% +permeability regions which flux is being + + + align:start position:0% +permeability regions which flux is being +forced across this lumped model is + + align:start position:0% +forced across this lumped model is + + + align:start position:0% +forced across this lumped model is +pretty + + align:start position:0% +pretty + + + align:start position:0% +pretty +good okay and it's a lot easier than + + align:start position:0% +good okay and it's a lot easier than + + + align:start position:0% +good okay and it's a lot easier than +starting to write Maxwell's + + align:start position:0% +starting to write Maxwell's + + + align:start position:0% +starting to write Maxwell's +equations okay now what does it take for + + align:start position:0% +equations okay now what does it take for + + + align:start position:0% +equations okay now what does it take for +a circuit model to work right I mean I + + align:start position:0% +a circuit model to work right I mean I + + + align:start position:0% +a circuit model to work right I mean I +sort of told you what the across + + align:start position:0% +sort of told you what the across + + + align:start position:0% +sort of told you what the across +variable is that's + + align:start position:0% +variable is that's + + + align:start position:0% +variable is that's +MMF the through variable is flux and I + + align:start position:0% +MMF the through variable is flux and I + + + align:start position:0% +MMF the through variable is flux and I +have my reluctance elements but what do + + align:start position:0% +have my reluctance elements but what do + + + align:start position:0% +have my reluctance elements but what do +I need to make a circuit model work I + + align:start position:0% +I need to make a circuit model work I + + + align:start position:0% +I need to make a circuit model work I +mean why why should it work to for the + + align:start position:0% +mean why why should it work to for the + + + align:start position:0% +mean why why should it work to for the +general case well what do I have an + + align:start position:0% +general case well what do I have an + + + align:start position:0% +general case well what do I have an +electrical circuit I have kvl and + + align:start position:0% +electrical circuit I have kvl and + + + align:start position:0% +electrical circuit I have kvl and +KCl + + align:start position:0% +KCl + + + align:start position:0% +KCl +right well let's come back over to ma + + align:start position:0% +right well let's come back over to ma + + + align:start position:0% +right well let's come back over to ma +Maxwell's equations basically flux + + align:start position:0% +Maxwell's equations basically flux + + + align:start position:0% +Maxwell's equations basically flux +continuity says the integral of b. da + + align:start position:0% +continuity says the integral of b. da + + + align:start position:0% +continuity says the integral of b. da +going into some region is zero right + + align:start position:0% +going into some region is zero right + + + align:start position:0% +going into some region is zero right +that's essentially saying the net flux + + align:start position:0% +that's essentially saying the net flux + + + align:start position:0% +that's essentially saying the net flux +going into any piece of space must add + + align:start position:0% +going into any piece of space must add + + + align:start position:0% +going into any piece of space must add +up to + + align:start position:0% +up to + + + align:start position:0% +up to +zero that is exactly the magnetic + + align:start position:0% +zero that is exactly the magnetic + + + align:start position:0% +zero that is exactly the magnetic +circuit equivalent of + + align:start position:0% +circuit equivalent of + + + align:start position:0% +circuit equivalent of +KCl right and in fact if I think about + + align:start position:0% +KCl right and in fact if I think about + + + align:start position:0% +KCl right and in fact if I think about +kvl and KCl for electric circuits they + + align:start position:0% +kvl and KCl for electric circuits they + + + align:start position:0% +kvl and KCl for electric circuits they +also derive from Maxwell's equations + + align:start position:0% +also derive from Maxwell's equations + + + align:start position:0% +also derive from Maxwell's equations +they're actually approximations right + + align:start position:0% +they're actually approximations right + + + align:start position:0% +they're actually approximations right +KCl in the electric circuit I'm thinking + + align:start position:0% +KCl in the electric circuit I'm thinking + + + align:start position:0% +KCl in the electric circuit I'm thinking +that there's just no charge buildup it's + + align:start position:0% +that there's just no charge buildup it's + + + align:start position:0% +that there's just no charge buildup it's +a conservation of charge here thing here + + align:start position:0% +a conservation of charge here thing here + + + align:start position:0% +a conservation of charge here thing here +here I'm using flux continuity to + + align:start position:0% +here I'm using flux continuity to + + + align:start position:0% +here I'm using flux continuity to +justify + + align:start position:0% +justify + + + align:start position:0% +justify +CASL what am I doing here I'm saying + + align:start position:0% +CASL what am I doing here I'm saying + + + align:start position:0% +CASL what am I doing here I'm saying +that the sum of the n if you will around + + align:start position:0% +that the sum of the n if you will around + + + align:start position:0% +that the sum of the n if you will around +the loop or the sum of n * 5 * RC + 5 * + + align:start position:0% +the loop or the sum of n * 5 * RC + 5 * + + + align:start position:0% +the loop or the sum of n * 5 * RC + 5 * +RG is giving me ni I that that is + + align:start position:0% +RG is giving me ni I that that is + + + align:start position:0% +RG is giving me ni I that that is +essentially ampers + + align:start position:0% +essentially ampers + + + align:start position:0% +essentially ampers +law right ampers law is saying how does + + align:start position:0% +law right ampers law is saying how does + + + align:start position:0% +law right ampers law is saying how does +the MMF that I + + align:start position:0% +the MMF that I + + + align:start position:0% +the MMF that I +generate uh relate to the flux I get + + align:start position:0% +generate uh relate to the flux I get + + + align:start position:0% +generate uh relate to the flux I get +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +um this sum around this Loop is exactly + + align:start position:0% +um this sum around this Loop is exactly + + + align:start position:0% +um this sum around this Loop is exactly +what ampers law is doing + + align:start position:0% +what ampers law is doing + + + align:start position:0% +what ampers law is doing +okay so this is a pretty good tool for + + align:start position:0% +okay so this is a pretty good tool for + + + align:start position:0% +okay so this is a pretty good tool for +handling the general + + align:start position:0% +handling the general + + + align:start position:0% +handling the general +case okay let me stop there and just see + + align:start position:0% +case okay let me stop there and just see + + + align:start position:0% +case okay let me stop there and just see +what questions we have well before I do + + align:start position:0% +what questions we have well before I do + + + align:start position:0% +what questions we have well before I do +that so let me just clarify right in an + + align:start position:0% +that so let me just clarify right in an + + + align:start position:0% +that so let me just clarify right in an +electric + + align:start position:0% +electric + + + align:start position:0% +electric +circuit right I have an + + align:start position:0% + + + + align:start position:0% + +EMF and I'm saying in my magnetic + + align:start position:0% +EMF and I'm saying in my magnetic + + + align:start position:0% +EMF and I'm saying in my magnetic +circuit what I'm going to have + + align:start position:0% +circuit what I'm going to have + + + align:start position:0% +circuit what I'm going to have +is or I'll draw it this way in yellow I + + align:start position:0% +is or I'll draw it this way in yellow I + + + align:start position:0% +is or I'll draw it this way in yellow I +have my MMF n + + align:start position:0% + + + + align:start position:0% + +i in an electric circuit I have current + + align:start position:0% +i in an electric circuit I have current + + + align:start position:0% +i in an electric circuit I have current +whereas in my magnetic + + align:start position:0% +whereas in my magnetic + + + align:start position:0% +whereas in my magnetic +circuit I have + + align:start position:0% +circuit I have + + + align:start position:0% +circuit I have +flux and in my electric circuit I have + + align:start position:0% +flux and in my electric circuit I have + + + align:start position:0% +flux and in my electric circuit I have +resistance R is equal to LX over Sigma + + align:start position:0% +resistance R is equal to LX over Sigma + + + align:start position:0% +resistance R is equal to LX over Sigma +ax + + align:start position:0% +ax + + + align:start position:0% +ax +for my resistor and in my magnetic + + align:start position:0% +for my resistor and in my magnetic + + + align:start position:0% +for my resistor and in my magnetic +circuit I have a reluctance which is LX + + align:start position:0% +circuit I have a reluctance which is LX + + + align:start position:0% +circuit I have a reluctance which is LX +over mux ax okay so these are just the + + align:start position:0% +over mux ax okay so these are just the + + + align:start position:0% +over mux ax okay so these are just the +mappings between my electric circuit and + + align:start position:0% +mappings between my electric circuit and + + + align:start position:0% +mappings between my electric circuit and +my magnetic + + align:start position:0% +my magnetic + + + align:start position:0% +my magnetic +circuit and I have + + align:start position:0% +circuit and I have + + + align:start position:0% +circuit and I have +kvl and KCl in each case okay so let me + + align:start position:0% +kvl and KCl in each case okay so let me + + + align:start position:0% +kvl and KCl in each case okay so let me +pause there are there any + + align:start position:0% +pause there are there any + + + align:start position:0% +pause there are there any +questions about this + + align:start position:0% +questions about this + + + align:start position:0% +questions about this +model what exactly is the area of air + + align:start position:0% +model what exactly is the area of air + + + align:start position:0% +model what exactly is the area of air +gap + + align:start position:0% + + + + align:start position:0% + +it doesn't have to + + align:start position:0% +it doesn't have to + + + align:start position:0% +it doesn't have to +be um if I imagined that this Gap was + + align:start position:0% +be um if I imagined that this Gap was + + + align:start position:0% +be um if I imagined that this Gap was +really + + align:start position:0% +really + + + align:start position:0% +really +small okay so I have a tiny Gap and a + + align:start position:0% +small okay so I have a tiny Gap and a + + + align:start position:0% +small okay so I have a tiny Gap and a +big say crosssectional area right most + + align:start position:0% +big say crosssectional area right most + + + align:start position:0% +big say crosssectional area right most +of the + + align:start position:0% +of the + + + align:start position:0% +of the +flux just kind of go straight across + + align:start position:0% +flux just kind of go straight across + + + align:start position:0% +flux just kind of go straight across +right like + + align:start position:0% + + + + align:start position:0% + +this and maybe I get a tiny bit of + + align:start position:0% +this and maybe I get a tiny bit of + + + align:start position:0% +this and maybe I get a tiny bit of +fringing out at the + + align:start position:0% +fringing out at the + + + align:start position:0% +fringing out at the +corners okay so for the most part if I + + align:start position:0% +corners okay so for the most part if I + + + align:start position:0% +corners okay so for the most part if I +ask where's flux going there's not I + + align:start position:0% +ask where's flux going there's not I + + + align:start position:0% +ask where's flux going there's not I +mean flux always leaves the surface + + align:start position:0% +mean flux always leaves the surface + + + align:start position:0% +mean flux always leaves the surface +perpendicularly right so there's not a + + align:start position:0% +perpendicularly right so there's not a + + + align:start position:0% +perpendicularly right so there's not a +lot of flux that's bending out so that + + align:start position:0% +lot of flux that's bending out so that + + + align:start position:0% +lot of flux that's bending out so that +the effective area through which this is + + align:start position:0% +the effective area through which this is + + + align:start position:0% +the effective area through which this is +going in the Gap is about the same as + + align:start position:0% +going in the Gap is about the same as + + + align:start position:0% +going in the Gap is about the same as +the core now if I had a really big gap + + align:start position:0% +the core now if I had a really big gap + + + align:start position:0% +the core now if I had a really big gap +what I get is a bunch of flux doing + + align:start position:0% +what I get is a bunch of flux doing + + + align:start position:0% +what I get is a bunch of flux doing +this kind of thing right so then the + + align:start position:0% +this kind of thing right so then the + + + align:start position:0% +this kind of thing right so then the +effective area through which it's + + align:start position:0% +effective area through which it's + + + align:start position:0% +effective area through which it's +traveling out in the free space is + + align:start position:0% +traveling out in the free space is + + + align:start position:0% +traveling out in the free space is +effectively bigger than it is in the + + align:start position:0% +effectively bigger than it is in the + + + align:start position:0% +effectively bigger than it is in the +core but if I consider this case where I + + align:start position:0% +core but if I consider this case where I + + + align:start position:0% +core but if I consider this case where I +have a very short Gap you know I can + + align:start position:0% +have a very short Gap you know I can + + + align:start position:0% +have a very short Gap you know I can +ignore fringing and so I just treat + + align:start position:0% +ignore fringing and so I just treat + + + align:start position:0% +ignore fringing and so I just treat +areas core as area Gap you know if you + + align:start position:0% +areas core as area Gap you know if you + + + align:start position:0% +areas core as area Gap you know if you +said I suddenly have a tiny bit of core + + align:start position:0% +said I suddenly have a tiny bit of core + + + align:start position:0% +said I suddenly have a tiny bit of core +material and a lot of stuff going on + + align:start position:0% +material and a lot of stuff going on + + + align:start position:0% +material and a lot of stuff going on +that's very hard to calculate right + + align:start position:0% +that's very hard to calculate right + + + align:start position:0% +that's very hard to calculate right +magnetic circuits tend to work well when + + align:start position:0% +magnetic circuits tend to work well when + + + align:start position:0% +magnetic circuits tend to work well when +I have sort of a lot of high + + align:start position:0% +I have sort of a lot of high + + + align:start position:0% +I have sort of a lot of high +permeability material to carry my flux + + align:start position:0% +permeability material to carry my flux + + + align:start position:0% +permeability material to carry my flux +and + + align:start position:0% +and + + + align:start position:0% +and +little spaces like high reluctance + + align:start position:0% +little spaces like high reluctance + + + align:start position:0% +little spaces like high reluctance +regions to which it's going to jump + + align:start position:0% +regions to which it's going to jump + + + align:start position:0% +regions to which it's going to jump +across short distances that's the best + + align:start position:0% +across short distances that's the best + + + align:start position:0% +across short distances that's the best +case for these magnetic circuits great + + align:start position:0% +case for these magnetic circuits great + + + align:start position:0% +case for these magnetic circuits great +question other + + align:start position:0% + + + + align:start position:0% + +questions so what does this kind of + + align:start position:0% +questions so what does this kind of + + + align:start position:0% +questions so what does this kind of +thing let us + + align:start position:0% +thing let us + + + align:start position:0% +thing let us +do well it means that you know you can + + align:start position:0% +do well it means that you know you can + + + align:start position:0% +do well it means that you know you can +say for example suppose I suddenly said + + align:start position:0% +say for example suppose I suddenly said + + + align:start position:0% +say for example suppose I suddenly said +you know what I'm going to build this + + align:start position:0% +you know what I'm going to build this + + + align:start position:0% +you know what I'm going to build this +structure + + align:start position:0% + + + + align:start position:0% + +I'll say the whole thing has a + + align:start position:0% +I'll say the whole thing has a + + + align:start position:0% +I'll say the whole thing has a +cross-sectional area a but here I go and + + align:start position:0% +cross-sectional area a but here I go and + + + align:start position:0% +cross-sectional area a but here I go and +I'm going to put my winding on the + + align:start position:0% +I'm going to put my winding on the + + + align:start position:0% +I'm going to put my winding on the +center leg here and this is actually a + + align:start position:0% +center leg here and this is actually a + + + align:start position:0% +center leg here and this is actually a +kind of structure you might build in + + align:start position:0% +kind of structure you might build in + + + align:start position:0% +kind of structure you might build in +fact for something right so I have n and + + align:start position:0% +fact for something right so I have n and + + + align:start position:0% +fact for something right so I have n and +I have I right and I might say okay I + + align:start position:0% +I have I right and I might say okay I + + + align:start position:0% +I have I right and I might say okay I +have some Dimension sort of a here and I + + align:start position:0% +have some Dimension sort of a here and I + + + align:start position:0% +have some Dimension sort of a here and I +know the cross-sectional area of the + + align:start position:0% +know the cross-sectional area of the + + + align:start position:0% +know the cross-sectional area of the +whole thing and so forth how could I + + align:start position:0% +whole thing and so forth how could I + + + align:start position:0% +whole thing and so forth how could I +find the flux and inductance of the + + align:start position:0% +find the flux and inductance of the + + + align:start position:0% +find the flux and inductance of the +structure I might I might recognize that + + align:start position:0% +structure I might I might recognize that + + + align:start position:0% +structure I might I might recognize that +flux is going to come up here some of + + align:start position:0% +flux is going to come up here some of + + + align:start position:0% +flux is going to come up here some of +it's going to go this way and I'll have + + align:start position:0% +it's going to go this way and I'll have + + + align:start position:0% +it's going to go this way and I'll have +F1 and I'll have some flux that goes + + align:start position:0% +F1 and I'll have some flux that goes + + + align:start position:0% +F1 and I'll have some flux that goes +this way and I'll have 5 2 and this flux + + align:start position:0% +this way and I'll have 5 2 and this flux + + + align:start position:0% +this way and I'll have 5 2 and this flux +in the middle will be 51 + 5 2 + + align:start position:0% +in the middle will be 51 + 5 2 + + + align:start position:0% +in the middle will be 51 + 5 2 +right can I calculate that structure + + align:start position:0% +right can I calculate that structure + + + align:start position:0% +right can I calculate that structure +yeah why because I could say okay + + align:start position:0% +yeah why because I could say okay + + + align:start position:0% +yeah why because I could say okay +I have + + align:start position:0% + + + + align:start position:0% + +ni okay and then I say you know there's + + align:start position:0% +ni okay and then I say you know there's + + + align:start position:0% +ni okay and then I say you know there's +this block of material and I'm only sort + + align:start position:0% +this block of material and I'm only sort + + + align:start position:0% +this block of material and I'm only sort +of drawing this 2D there's this block of + + align:start position:0% +of drawing this 2D there's this block of + + + align:start position:0% +of drawing this 2D there's this block of +material going up the middle and maybe + + align:start position:0% +material going up the middle and maybe + + + align:start position:0% +material going up the middle and maybe +I'll call that sort of I don't know what + + align:start position:0% +I'll call that sort of I don't know what + + + align:start position:0% +I'll call that sort of I don't know what +I called in my notes maybe I called that + + align:start position:0% + + + + align:start position:0% + +R3 and then there's some path through + + align:start position:0% +R3 and then there's some path through + + + align:start position:0% +R3 and then there's some path through +the core that goes this way and this way + + align:start position:0% +the core that goes this way and this way + + + align:start position:0% +the core that goes this way and this way +maybe I'll call that rc1 + + align:start position:0% +maybe I'll call that rc1 + + + align:start position:0% +maybe I'll call that rc1 +and there's some Gap here and I'll call + + align:start position:0% +and there's some Gap here and I'll call + + + align:start position:0% +and there's some Gap here and I'll call +that + + align:start position:0% +that + + + align:start position:0% +that +rg1 right and the same on the other side + + align:start position:0% +rg1 right and the same on the other side + + + align:start position:0% +rg1 right and the same on the other side +there's some + + align:start position:0% +there's some + + + align:start position:0% +there's some +rc2 and some rgap 2 + + align:start position:0% +rc2 and some rgap 2 + + + align:start position:0% +rc2 and some rgap 2 +right and then I could say okay well you + + align:start position:0% +right and then I could say okay well you + + + align:start position:0% +right and then I could say okay well you +know KV KCl in this magnetic circuit all + + align:start position:0% +know KV KCl in this magnetic circuit all + + + align:start position:0% +know KV KCl in this magnetic circuit all +apply and I can find the total flux five + + align:start position:0% +apply and I can find the total flux five + + + align:start position:0% +apply and I can find the total flux five +so I could just say look the net + + align:start position:0% +so I could just say look the net + + + align:start position:0% +so I could just say look the net +reluctance looking up into here is + + align:start position:0% +reluctance looking up into here is + + + align:start position:0% +reluctance looking up into here is +simply equal to R + + align:start position:0% +simply equal to R + + + align:start position:0% +simply equal to R +net is simply equal to + + align:start position:0% +net is simply equal to + + + align:start position:0% +net is simply equal to +R3 + + align:start position:0% +R3 + + + align:start position:0% +R3 +plus + + align:start position:0% +plus + + + align:start position:0% +plus +rc1 plus r Gap 1 in + + align:start position:0% +rc1 plus r Gap 1 in + + + align:start position:0% +rc1 plus r Gap 1 in +parallel with + + align:start position:0% +parallel with + + + align:start position:0% +parallel with +rc2 plus our Gap + + align:start position:0% +rc2 plus our Gap + + + align:start position:0% +rc2 plus our Gap +2 right I now have the net reluctance I + + align:start position:0% +2 right I now have the net reluctance I + + + align:start position:0% +2 right I now have the net reluctance I +then get fi is being the FI in the + + align:start position:0% +then get fi is being the FI in the + + + align:start position:0% +then get fi is being the FI in the +center leg is being equal to uh n + + align:start position:0% +center leg is being equal to uh n + + + align:start position:0% +center leg is being equal to uh n +R + + align:start position:0% +R + + + align:start position:0% +R +net and then I can find Lambda is equal + + align:start position:0% +net and then I can find Lambda is equal + + + align:start position:0% +net and then I can find Lambda is equal +to + + align:start position:0% + + + + align:start position:0% + +N2 uh over R + + align:start position:0% +N2 uh over R + + + align:start position:0% +N2 uh over R +net time I and this is the inductance + + align:start position:0% +net time I and this is the inductance + + + align:start position:0% +net time I and this is the inductance +right so boom just by knowing the + + align:start position:0% +right so boom just by knowing the + + + align:start position:0% +right so boom just by knowing the +geometry of each of these things and I + + align:start position:0% +geometry of each of these things and I + + + align:start position:0% +geometry of each of these things and I +calculate inductance and I'm + + align:start position:0% +calculate inductance and I'm + + + align:start position:0% +calculate inductance and I'm +done all right and I didn't have to + + align:start position:0% +done all right and I didn't have to + + + align:start position:0% +done all right and I didn't have to +start writing Maxs equations or anything + + align:start position:0% +start writing Maxs equations or anything + + + align:start position:0% +start writing Maxs equations or anything +else does that make sense everybody + + align:start position:0% + + + + align:start position:0% + +now this is fully as legitimate as + + align:start position:0% +now this is fully as legitimate as + + + align:start position:0% +now this is fully as legitimate as +electric circuits deriving it down from + + align:start position:0% +electric circuits deriving it down from + + + align:start position:0% +electric circuits deriving it down from +Maxwell's + + align:start position:0% +Maxwell's + + + align:start position:0% +Maxwell's +equations I will + + align:start position:0% +equations I will + + + align:start position:0% +equations I will +say that um there are some kind of + + align:start position:0% +say that um there are some kind of + + + align:start position:0% +say that um there are some kind of +limitations that make it harder to use + + align:start position:0% +limitations that make it harder to use + + + align:start position:0% +limitations that make it harder to use +than an electric circuit why is that if + + align:start position:0% +than an electric circuit why is that if + + + align:start position:0% +than an electric circuit why is that if +I go build some electric circuit like + + align:start position:0% +I go build some electric circuit like + + + align:start position:0% +I go build some electric circuit like +this right you know I go get a battery + + align:start position:0% +this right you know I go get a battery + + + align:start position:0% +this right you know I go get a battery +and some resistors and stuff right + + align:start position:0% +and some resistors and stuff right + + + align:start position:0% +and some resistors and stuff right +it's a pretty good bet that my current's + + align:start position:0% +it's a pretty good bet that my current's + + + align:start position:0% +it's a pretty good bet that my current's +flowing around this Loop right the the + + align:start position:0% +flowing around this Loop right the the + + + align:start position:0% +flowing around this Loop right the the +difference in conduct electrical + + align:start position:0% +difference in conduct electrical + + + align:start position:0% +difference in conduct electrical +conductivity between my conductors and + + align:start position:0% +conductivity between my conductors and + + + align:start position:0% +conductivity between my conductors and +my insulators might be like 12 orders of + + align:start position:0% +my insulators might be like 12 orders of + + + align:start position:0% +my insulators might be like 12 orders of +magnitude right so you know if I have 10 + + align:start position:0% +magnitude right so you know if I have 10 + + + align:start position:0% +magnitude right so you know if I have 10 +to the 12th difference in conductivity + + align:start position:0% +to the 12th difference in conductivity + + + align:start position:0% +to the 12th difference in conductivity +between my wire and the stuff that's + + align:start position:0% +between my wire and the stuff that's + + + align:start position:0% +between my wire and the stuff that's +around it all the current Goes Through + + align:start position:0% +around it all the current Goes Through + + + align:start position:0% +around it all the current Goes Through +the Wire right so KCl is pretty darn + + align:start position:0% +the Wire right so KCl is pretty darn + + + align:start position:0% +the Wire right so KCl is pretty darn +good + + align:start position:0% +good + + + align:start position:0% +good +right um + + align:start position:0% +right um + + + align:start position:0% +right um +on the other hand in a magnetic circuit + + align:start position:0% +on the other hand in a magnetic circuit + + + align:start position:0% +on the other hand in a magnetic circuit +right what's guiding the flux what makes + + align:start position:0% +right what's guiding the flux what makes + + + align:start position:0% +right what's guiding the flux what makes +this reluctance element work well + + align:start position:0% +this reluctance element work well + + + align:start position:0% +this reluctance element work well +instead of conductivity which is guiding + + align:start position:0% +instead of conductivity which is guiding + + + align:start position:0% +instead of conductivity which is guiding +where electrical currents go I have + + align:start position:0% +where electrical currents go I have + + + align:start position:0% +where electrical currents go I have +permeability determining where magnetic + + align:start position:0% +permeability determining where magnetic + + + align:start position:0% +permeability determining where magnetic +flux + + align:start position:0% +flux + + + align:start position:0% +flux +goes and typical magnetic materials you + + align:start position:0% +goes and typical magnetic materials you + + + align:start position:0% +goes and typical magnetic materials you +know that you use in power applications + + align:start position:0% +know that you use in power applications + + + align:start position:0% +know that you use in power applications +might be 10 3 or 10 4 time + + align:start position:0% +might be 10 3 or 10 4 time + + + align:start position:0% +might be 10 3 or 10 4 time +mu okay and what and not not 10 12 and + + align:start position:0% +mu okay and what and not not 10 12 and + + + align:start position:0% +mu okay and what and not not 10 12 and +so what that means means is that the + + align:start position:0% +so what that means means is that the + + + align:start position:0% +so what that means means is that the +things that are my conductors like my + + align:start position:0% +things that are my conductors like my + + + align:start position:0% +things that are my conductors like my +cores right my conductors the magnetic + + align:start position:0% +cores right my conductors the magnetic + + + align:start position:0% +cores right my conductors the magnetic +flux are my cores only have 10 the 3 or + + align:start position:0% +flux are my cores only have 10 the 3 or + + + align:start position:0% +flux are my cores only have 10 the 3 or +10 4 times the the magnetic conductivity + + align:start position:0% +10 4 times the the magnetic conductivity + + + align:start position:0% +10 4 times the the magnetic conductivity +as the space around it so magnetic + + align:start position:0% +as the space around it so magnetic + + + align:start position:0% +as the space around it so magnetic +circuits are kind of leaky if you will + + align:start position:0% +circuits are kind of leaky if you will + + + align:start position:0% +circuits are kind of leaky if you will +right it'd be like building an electric + + align:start position:0% +right it'd be like building an electric + + + align:start position:0% +right it'd be like building an electric +circuit where your insulators are crummy + + align:start position:0% +circuit where your insulators are crummy + + + align:start position:0% +circuit where your insulators are crummy +and charges kind of currents are kind of + + align:start position:0% +and charges kind of currents are kind of + + + align:start position:0% +and charges kind of currents are kind of +flowing around in other places too so + + align:start position:0% +flowing around in other places too so + + + align:start position:0% +flowing around in other places too so +magnetic circuits tend to be more + + align:start position:0% +magnetic circuits tend to be more + + + align:start position:0% +magnetic circuits tend to be more +approximate than electrical circuits in + + align:start position:0% +approximate than electrical circuits in + + + align:start position:0% +approximate than electrical circuits in +sort of doing + + align:start position:0% +sort of doing + + + align:start position:0% +sort of doing +calculations okay and it becomes + + align:start position:0% +calculations okay and it becomes + + + align:start position:0% +calculations okay and it becomes +particularly hard when you start to say + + align:start position:0% +particularly hard when you start to say + + + align:start position:0% +particularly hard when you start to say +okay I've got really big gaps and like + + align:start position:0% +okay I've got really big gaps and like + + + align:start position:0% +okay I've got really big gaps and like +fluxes going out here a lot right then + + align:start position:0% +fluxes going out here a lot right then + + + align:start position:0% +fluxes going out here a lot right then +it's not that this the model's wrong + + align:start position:0% +it's not that this the model's wrong + + + align:start position:0% +it's not that this the model's wrong +it's just hard to figure out what the + + align:start position:0% +it's just hard to figure out what the + + + align:start position:0% +it's just hard to figure out what the +correct areas and what the + + align:start position:0% +correct areas and what the + + + align:start position:0% +correct areas and what the +correct uh what the correct reluctances + + align:start position:0% +correct uh what the correct reluctances + + + align:start position:0% +correct uh what the correct reluctances +and so forth are right so you know + + align:start position:0% +and so forth are right so you know + + + align:start position:0% +and so forth are right so you know +magnetic circuits you just got to think + + align:start position:0% +magnetic circuits you just got to think + + + align:start position:0% +magnetic circuits you just got to think +of them as being a little bit leaky okay + + align:start position:0% +of them as being a little bit leaky okay + + + align:start position:0% +of them as being a little bit leaky okay +and so typically what we're relying on + + align:start position:0% +and so typically what we're relying on + + + align:start position:0% +and so typically what we're relying on +is sections of core that are very low + + align:start position:0% +is sections of core that are very low + + + align:start position:0% +is sections of core that are very low +reluctance and then small pieces that + + align:start position:0% +reluctance and then small pieces that + + + align:start position:0% +reluctance and then small pieces that +are fairly High + + align:start position:0% +are fairly High + + + align:start position:0% +are fairly High +reluctance okay in order to make the + + align:start position:0% +reluctance okay in order to make the + + + align:start position:0% +reluctance okay in order to make the +calculations very accurate but you can + + align:start position:0% +calculations very accurate but you can + + + align:start position:0% +calculations very accurate but you can +do with them one way or another and + + align:start position:0% +do with them one way or another and + + + align:start position:0% +do with them one way or another and +they're also a great thinking tool even + + align:start position:0% +they're also a great thinking tool even + + + align:start position:0% +they're also a great thinking tool even +when you can't the other thing I will + + align:start position:0% +when you can't the other thing I will + + + align:start position:0% +when you can't the other thing I will +say is that an electrical circuit right + + align:start position:0% +say is that an electrical circuit right + + + align:start position:0% +say is that an electrical circuit right +our unit of conductivity is Sigma right + + align:start position:0% +our unit of conductivity is Sigma right + + + align:start position:0% +our unit of conductivity is Sigma right +we have J equals Sigma e like Ohm's law + + align:start position:0% +we have J equals Sigma e like Ohm's law + + + align:start position:0% +we have J equals Sigma e like Ohm's law +right and materials that are conductive + + align:start position:0% +right and materials that are conductive + + + align:start position:0% +right and materials that are conductive +they tend to follow that law over a + + align:start position:0% +they tend to follow that law over a + + + align:start position:0% +they tend to follow that law over a +pretty wide range of electric fields and + + align:start position:0% +pretty wide range of electric fields and + + + align:start position:0% +pretty wide range of electric fields and +current densities not always right like + + align:start position:0% +current densities not always right like + + + align:start position:0% +current densities not always right like +you you get running the limits of that + + align:start position:0% +you you get running the limits of that + + + align:start position:0% +you you get running the limits of that +but in magnetic magnetic structures what + + align:start position:0% +but in magnetic magnetic structures what + + + align:start position:0% +but in magnetic magnetic structures what +we'll see is if I have the relationship + + align:start position:0% +we'll see is if I have the relationship + + + align:start position:0% +we'll see is if I have the relationship +between B and H right it tends to do + + align:start position:0% +between B and H right it tends to do + + + align:start position:0% +between B and H right it tends to do +something like this that we'll see um + + align:start position:0% +something like this that we'll see um + + + align:start position:0% +something like this that we'll see um +you know if this is the MU of the core + + align:start position:0% +you know if this is the MU of the core + + + align:start position:0% +you know if this is the MU of the core +material it's above some + + align:start position:0% +material it's above some + + + align:start position:0% +material it's above some +saturation flux density right this drops + + align:start position:0% +saturation flux density right this drops + + + align:start position:0% +saturation flux density right this drops +off and starts to become mot basically + + align:start position:0% +off and starts to become mot basically + + + align:start position:0% +off and starts to become mot basically +all the magnetic domains align and it + + align:start position:0% +all the magnetic domains align and it + + + align:start position:0% +all the magnetic domains align and it +doesn't behave very well anymore and so + + align:start position:0% +doesn't behave very well anymore and so + + + align:start position:0% +doesn't behave very well anymore and so +my approximation of thinking of just + + align:start position:0% +my approximation of thinking of just + + + align:start position:0% +my approximation of thinking of just +something as some permeability mu core + + align:start position:0% +something as some permeability mu core + + + align:start position:0% +something as some permeability mu core +only applies over some ranges of flux + + align:start position:0% +only applies over some ranges of flux + + + align:start position:0% +only applies over some ranges of flux +densities so I might have to go back and + + align:start position:0% +densities so I might have to go back and + + + align:start position:0% +densities so I might have to go back and +put that into my thinking too I can't + + align:start position:0% +put that into my thinking too I can't + + + align:start position:0% +put that into my thinking too I can't +use these out to infinite flux densities + + align:start position:0% +use these out to infinite flux densities + + + align:start position:0% +use these out to infinite flux densities +the way I might think you know I might + + align:start position:0% +the way I might think you know I might + + + align:start position:0% +the way I might think you know I might +be less hesitant to do in a conventional + + align:start position:0% +be less hesitant to do in a conventional + + + align:start position:0% +be less hesitant to do in a conventional +electrical circuit so there's some + + align:start position:0% +electrical circuit so there's some + + + align:start position:0% +electrical circuit so there's some +limitations on this model but boy does + + align:start position:0% +limitations on this model but boy does + + + align:start position:0% +limitations on this model but boy does +it make your life easy okay and we're + + align:start position:0% +it make your life easy okay and we're + + + align:start position:0% +it make your life easy okay and we're +going to take great advantage of it + + align:start position:0% +going to take great advantage of it + + + align:start position:0% +going to take great advantage of it +moving + + align:start position:0% +moving + + + align:start position:0% +moving +forward any + + align:start position:0% + + + + align:start position:0% + +questions okay great we will take up + + align:start position:0% +questions okay great we will take up + + + align:start position:0% +questions okay great we will take up +more on magnetics and magnetic circuits + + align:start position:0% +more on magnetics and magnetic circuits + + + align:start position:0% +more on magnetics and magnetic circuits +tomorrow uh sorry Monday \ No newline at end of file diff --git a/ZTNniGvY5IQ.txt b/ZTNniGvY5IQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..528a03755ec2594f3ebf68f93661d230a32bbc2f --- /dev/null +++ b/ZTNniGvY5IQ.txt @@ -0,0 +1,2171 @@ +align:start position:0% + +okay uh so this is a prepare the way + + align:start position:0% +okay uh so this is a prepare the way + + + align:start position:0% +okay uh so this is a prepare the way +video about symmetric + + align:start position:0% +video about symmetric + + + align:start position:0% +video about symmetric +matrices and complex + + align:start position:0% +matrices and complex + + + align:start position:0% +matrices and complex +matrices um we'll see symmetric matrices + + align:start position:0% +matrices um we'll see symmetric matrices + + + align:start position:0% +matrices um we'll see symmetric matrices +in uh second order systems of + + align:start position:0% +in uh second order systems of + + + align:start position:0% +in uh second order systems of +differential equations symmetric + + align:start position:0% +differential equations symmetric + + + align:start position:0% +differential equations symmetric +matrices are the best they have special + + align:start position:0% +matrices are the best they have special + + + align:start position:0% +matrices are the best they have special +properties and we want to see what are + + align:start position:0% +properties and we want to see what are + + + align:start position:0% +properties and we want to see what are +the special properties of the igen + + align:start position:0% +the special properties of the igen + + + align:start position:0% +the special properties of the igen +values and the igen vectors and I guess + + align:start position:0% +values and the igen vectors and I guess + + + align:start position:0% +values and the igen vectors and I guess +the title of this lecture tells you what + + align:start position:0% +the title of this lecture tells you what + + + align:start position:0% +the title of this lecture tells you what +those properties are so if a matrix is + + align:start position:0% +those properties are so if a matrix is + + + align:start position:0% +those properties are so if a matrix is +symmetric and I'll use capital S for + + align:start position:0% +symmetric and I'll use capital S for + + + align:start position:0% +symmetric and I'll use capital S for +symmetric Matrix the first point is the + + align:start position:0% +symmetric Matrix the first point is the + + + align:start position:0% +symmetric Matrix the first point is the +igen values are + + align:start position:0% +igen values are + + + align:start position:0% +igen values are +real which is not automatic but it's + + align:start position:0% +real which is not automatic but it's + + + align:start position:0% +real which is not automatic but it's +always true if the Matrix is symmetric + + align:start position:0% +always true if the Matrix is symmetric + + + align:start position:0% +always true if the Matrix is symmetric +and the second even more special point + + align:start position:0% +and the second even more special point + + + align:start position:0% +and the second even more special point +is that the ion vectors are + + align:start position:0% +is that the ion vectors are + + + align:start position:0% +is that the ion vectors are +perpendicular to each other different + + align:start position:0% +perpendicular to each other different + + + align:start position:0% +perpendicular to each other different +igen vectors for different IG values + + align:start position:0% +igen vectors for different IG values + + + align:start position:0% +igen vectors for different IG values +come out perpendicular those are + + align:start position:0% +come out perpendicular those are + + + align:start position:0% +come out perpendicular those are +beautiful properties they pay off so can + + align:start position:0% +beautiful properties they pay off so can + + + align:start position:0% +beautiful properties they pay off so can +I actually so that's the symmetric + + align:start position:0% +I actually so that's the symmetric + + + align:start position:0% +I actually so that's the symmetric +Matrix and that's what I just said real + + align:start position:0% +Matrix and that's what I just said real + + + align:start position:0% +Matrix and that's what I just said real +Lambda orthogonal X I also we could look + + align:start position:0% +Lambda orthogonal X I also we could look + + + align:start position:0% +Lambda orthogonal X I also we could look +at anti- symmetric matrices the + + align:start position:0% +at anti- symmetric matrices the + + + align:start position:0% +at anti- symmetric matrices the +transposes minus the Matrix in that case + + align:start position:0% +transposes minus the Matrix in that case + + + align:start position:0% +transposes minus the Matrix in that case +we don't have real igen values in fact + + align:start position:0% +we don't have real igen values in fact + + + align:start position:0% +we don't have real igen values in fact +we are sure to have pure imaginary I + + align:start position:0% +we are sure to have pure imaginary I + + + align:start position:0% +we are sure to have pure imaginary I +values I times something + + align:start position:0% +values I times something + + + align:start position:0% +values I times something +on the on the imaginary axis but again + + align:start position:0% +on the on the imaginary axis but again + + + align:start position:0% +on the on the imaginary axis but again +the igon vectors will be + + align:start position:0% +the igon vectors will be + + + align:start position:0% +the igon vectors will be +orthogonal however they will also be + + align:start position:0% +orthogonal however they will also be + + + align:start position:0% +orthogonal however they will also be +complex we're when we when we have uh + + align:start position:0% +complex we're when we when we have uh + + + align:start position:0% +complex we're when we when we have uh +anti- symmetric matrices we get into + + align:start position:0% +anti- symmetric matrices we get into + + + align:start position:0% +anti- symmetric matrices we get into +complex numbers can't help it even if + + align:start position:0% +complex numbers can't help it even if + + + align:start position:0% +complex numbers can't help it even if +the Matrix is real and then finally is + + align:start position:0% +the Matrix is real and then finally is + + + align:start position:0% +the Matrix is real and then finally is +the uh family of orthogonal + + align:start position:0% +the uh family of orthogonal + + + align:start position:0% +the uh family of orthogonal +matrices and those those are the mat + + align:start position:0% +matrices and those those are the mat + + + align:start position:0% +matrices and those those are the mat +those matrices have igen values of size + + align:start position:0% +those matrices have igen values of size + + + align:start position:0% +those matrices have igen values of size +one possibly complex but the magnitude + + align:start position:0% +one possibly complex but the magnitude + + + align:start position:0% +one possibly complex but the magnitude +of the number is one and again the igen + + align:start position:0% +of the number is one and again the igen + + + align:start position:0% +of the number is one and again the igen +vectors are orthogonal this is the the + + align:start position:0% +vectors are orthogonal this is the the + + + align:start position:0% +vectors are orthogonal this is the the +great family of uh real imaginary and + + align:start position:0% +great family of uh real imaginary and + + + align:start position:0% +great family of uh real imaginary and +unit circle for the igen values okay I + + align:start position:0% +unit circle for the igen values okay I + + + align:start position:0% +unit circle for the igen values okay I +want to do examples so I'll just have an + + align:start position:0% +want to do examples so I'll just have an + + + align:start position:0% +want to do examples so I'll just have an +example of everyone + + align:start position:0% + + + + align:start position:0% + +so there's a symmetric + + align:start position:0% +so there's a symmetric + + + align:start position:0% +so there's a symmetric +Matrix there's a anti-symmetric matrix + + align:start position:0% +Matrix there's a anti-symmetric matrix + + + align:start position:0% +Matrix there's a anti-symmetric matrix +if I transpose it it changes sign here + + align:start position:0% +if I transpose it it changes sign here + + + align:start position:0% +if I transpose it it changes sign here +is a + + align:start position:0% +is a + + + align:start position:0% +is a +combination not symmetric not + + align:start position:0% +combination not symmetric not + + + align:start position:0% +combination not symmetric not +anti-symmetric but still a good Matrix + + align:start position:0% +anti-symmetric but still a good Matrix + + + align:start position:0% +anti-symmetric but still a good Matrix +and there is an orthogonal + + align:start position:0% +and there is an orthogonal + + + align:start position:0% +and there is an orthogonal +Matrix orthogonal + + align:start position:0% +Matrix orthogonal + + + align:start position:0% +Matrix orthogonal +columns and those columns have length + + align:start position:0% +columns and those columns have length + + + align:start position:0% +columns and those columns have length +one that's why I've got the square root + + align:start position:0% +one that's why I've got the square root + + + align:start position:0% +one that's why I've got the square root +of two in there so these are the special + + align:start position:0% +of two in there so these are the special + + + align:start position:0% +of two in there so these are the special +matrices here you you could say here can + + align:start position:0% +matrices here you you could say here can + + + align:start position:0% +matrices here you you could say here can +I just draw a little picture of the + + align:start position:0% +I just draw a little picture of the + + + align:start position:0% +I just draw a little picture of the +complex plane there's the real + + align:start position:0% +complex plane there's the real + + + align:start position:0% +complex plane there's the real +axis here's the imaginary + + align:start position:0% + + + + align:start position:0% + +axis and here's + + align:start position:0% +axis and here's + + + align:start position:0% +axis and here's +the unit circle not greatly circular but + + align:start position:0% +the unit circle not greatly circular but + + + align:start position:0% +the unit circle not greatly circular but +close now so this is real ion values are + + align:start position:0% +close now so this is real ion values are + + + align:start position:0% +close now so this is real ion values are +on the real axis when s transpose equal + + align:start position:0% +on the real axis when s transpose equal + + + align:start position:0% +on the real axis when s transpose equal +s they're on the imaginary axis when a + + align:start position:0% +s they're on the imaginary axis when a + + + align:start position:0% +s they're on the imaginary axis when a +transpose equal minus a and they're on + + align:start position:0% +transpose equal minus a and they're on + + + align:start position:0% +transpose equal minus a and they're on +the unit circle when Q transpose Q is + + align:start position:0% +the unit circle when Q transpose Q is + + + align:start position:0% +the unit circle when Q transpose Q is +the identity q transposes q inverse in + + align:start position:0% +the identity q transposes q inverse in + + + align:start position:0% +the identity q transposes q inverse in +this case Q transposes Q inverse here + + align:start position:0% +this case Q transposes Q inverse here + + + align:start position:0% +this case Q transposes Q inverse here +the transposes The Matrix here the + + align:start position:0% +the transposes The Matrix here the + + + align:start position:0% +the transposes The Matrix here the +transposes minus the Matrix and you see + + align:start position:0% +transposes minus the Matrix and you see + + + align:start position:0% +transposes minus the Matrix and you see +the beautiful picture of igen values + + align:start position:0% +the beautiful picture of igen values + + + align:start position:0% +the beautiful picture of igen values +where they where they are and the ion + + align:start position:0% +where they where they are and the ion + + + align:start position:0% +where they where they are and the ion +vectors for all of those are orthogonal + + align:start position:0% +vectors for all of those are orthogonal + + + align:start position:0% +vectors for all of those are orthogonal +let let me find them here that symmetric + + align:start position:0% +let let me find them here that symmetric + + + align:start position:0% +let let me find them here that symmetric +Matrix has Lambda as 2 and + + align:start position:0% +Matrix has Lambda as 2 and + + + align:start position:0% +Matrix has Lambda as 2 and +four the trace is six the determinant is + + align:start position:0% +four the trace is six the determinant is + + + align:start position:0% +four the trace is six the determinant is +8 that's the right answer Lambda equal 2 + + align:start position:0% +8 that's the right answer Lambda equal 2 + + + align:start position:0% +8 that's the right answer Lambda equal 2 +and 4 and X would be oh uh 1 and minus + + align:start position:0% +and 4 and X would be oh uh 1 and minus + + + align:start position:0% +and 4 and X would be oh uh 1 and minus +one for two and for four it's one and + + align:start position:0% +one for two and for four it's one and + + + align:start position:0% +one for two and for four it's one and +one + + align:start position:0% +one + + + align:start position:0% +one +orthogonal orthogonal ion vectors take + + align:start position:0% +orthogonal orthogonal ion vectors take + + + align:start position:0% +orthogonal orthogonal ion vectors take +the dotproduct of those you get zero and + + align:start position:0% +the dotproduct of those you get zero and + + + align:start position:0% +the dotproduct of those you get zero and +realan values what about + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% +a + + + align:start position:0% +a +anti-symmetric the equation I I when I + + align:start position:0% +anti-symmetric the equation I I when I + + + align:start position:0% +anti-symmetric the equation I I when I +do determinant of Lambda minus + + align:start position:0% +do determinant of Lambda minus + + + align:start position:0% +do determinant of Lambda minus +a I get Lambda 2 + 1al 0 for this one + + align:start position:0% +a I get Lambda 2 + 1al 0 for this one + + + align:start position:0% +a I get Lambda 2 + 1al 0 for this one +that goes that leads me to Lambda 2 + 1 + + align:start position:0% +that goes that leads me to Lambda 2 + 1 + + + align:start position:0% +that goes that leads me to Lambda 2 + 1 += 0 so that gives me Lambda is I and + + align:start position:0% += 0 so that gives me Lambda is I and + + + align:start position:0% += 0 so that gives me Lambda is I and +minus I as promised on the imaginary + + align:start position:0% +minus I as promised on the imaginary + + + align:start position:0% +minus I as promised on the imaginary +axis and I guess that that Matrix is + + align:start position:0% +axis and I guess that that Matrix is + + + align:start position:0% +axis and I guess that that Matrix is +also an orthogonal Matrix and those ion + + align:start position:0% +also an orthogonal Matrix and those ion + + + align:start position:0% +also an orthogonal Matrix and those ion +values I and minus I are also on the + + align:start position:0% +values I and minus I are also on the + + + align:start position:0% +values I and minus I are also on the +circle so that a is also a q okay what + + align:start position:0% +circle so that a is also a q okay what + + + align:start position:0% +circle so that a is also a q okay what +are the ion vectors for that + + align:start position:0% +are the ion vectors for that + + + align:start position:0% +are the ion vectors for that +I think that the ion vectors turn out to + + align:start position:0% +I think that the ion vectors turn out to + + + align:start position:0% +I think that the ion vectors turn out to +be 1 + + align:start position:0% +be 1 + + + align:start position:0% +be 1 +I and 1 minus + + align:start position:0% + + + + align:start position:0% + +I oh those are orthogonal I'll have to + + align:start position:0% +I oh those are orthogonal I'll have to + + + align:start position:0% +I oh those are orthogonal I'll have to +tell you about orthogonality for complex + + align:start position:0% +tell you about orthogonality for complex + + + align:start position:0% +tell you about orthogonality for complex +vectors let me complete these examples + + align:start position:0% +vectors let me complete these examples + + + align:start position:0% +vectors let me complete these examples +what about the igen values of this one + + align:start position:0% +what about the igen values of this one + + + align:start position:0% +what about the igen values of this one +well that's an easy one can you connect + + align:start position:0% +well that's an easy one can you connect + + + align:start position:0% +well that's an easy one can you connect +that to a this is just B is just a plus + + align:start position:0% +that to a this is just B is just a plus + + + align:start position:0% +that to a this is just B is just a plus +3 * the identity to put threes on the + + align:start position:0% +3 * the identity to put threes on the + + + align:start position:0% +3 * the identity to put threes on the +diagonal so I'm expecting here the + + align:start position:0% +diagonal so I'm expecting here the + + + align:start position:0% +diagonal so I'm expecting here the +lambdas are when if here they were I and + + align:start position:0% +lambdas are when if here they were I and + + + align:start position:0% +lambdas are when if here they were I and +minus I all I've done is add three times + + align:start position:0% +minus I all I've done is add three times + + + align:start position:0% +minus I all I've done is add three times +the identity so I'm just adding three + + align:start position:0% +the identity so I'm just adding three + + + align:start position:0% +the identity so I'm just adding three +I'm shifting by three I'll have 3 + I + + align:start position:0% +I'm shifting by three I'll have 3 + I + + + align:start position:0% +I'm shifting by three I'll have 3 + I +and 3 - I and the same I can + + align:start position:0% +and 3 - I and the same I can + + + align:start position:0% +and 3 - I and the same I can +vectors and now find so that's a complex + + align:start position:0% +vectors and now find so that's a complex + + + align:start position:0% +vectors and now find so that's a complex +number uh that Matrix was not perfectly + + align:start position:0% +number uh that Matrix was not perfectly + + + align:start position:0% +number uh that Matrix was not perfectly +anti-symmetric it's not perfectly + + align:start position:0% +anti-symmetric it's not perfectly + + + align:start position:0% +anti-symmetric it's not perfectly +symmetric so that gave me a 3 + I + + align:start position:0% +symmetric so that gave me a 3 + I + + + align:start position:0% +symmetric so that gave me a 3 + I +somewhere not on the Axis or that Axis + + align:start position:0% +somewhere not on the Axis or that Axis + + + align:start position:0% +somewhere not on the Axis or that Axis +or the circle out there 3 + I and 3 + + align:start position:0% +or the circle out there 3 + I and 3 + + + align:start position:0% +or the circle out there 3 + I and 3 +minus I and finally this + + align:start position:0% +minus I and finally this + + + align:start position:0% +minus I and finally this +one the orthogonal Matrix what are the + + align:start position:0% +one the orthogonal Matrix what are the + + + align:start position:0% +one the orthogonal Matrix what are the +igon values of + + align:start position:0% +igon values of + + + align:start position:0% +igon values of +that uh + + align:start position:0% +that uh + + + align:start position:0% +that uh +um let's see I can see here I've added + + align:start position:0% +um let's see I can see here I've added + + + align:start position:0% +um let's see I can see here I've added +one times the identity just added the + + align:start position:0% +one times the identity just added the + + + align:start position:0% +one times the identity just added the +identity to the minus one1 so again I + + align:start position:0% +identity to the minus one1 so again I + + + align:start position:0% +identity to the minus one1 so again I +have this Min -11 plus the identity so I + + align:start position:0% +have this Min -11 plus the identity so I + + + align:start position:0% +have this Min -11 plus the identity so I +would have 1 + I and 1 - + + align:start position:0% +would have 1 + I and 1 - + + + align:start position:0% +would have 1 + I and 1 - +I from The Matrix and now I've got a + + align:start position:0% +I from The Matrix and now I've got a + + + align:start position:0% +I from The Matrix and now I've got a +division by square < TK of two square < + + align:start position:0% +division by square < TK of two square < + + + align:start position:0% +division by square < TK of two square < +TK of two + + align:start position:0% +TK of two + + + align:start position:0% +TK of two +and + + align:start position:0% +and + + + align:start position:0% +and +and those numbers Lambda you recognize + + align:start position:0% +and those numbers Lambda you recognize + + + align:start position:0% +and those numbers Lambda you recognize +that when you see a that number that is + + align:start position:0% +that when you see a that number that is + + + align:start position:0% +that when you see a that number that is +on the unit circle that is the where is + + align:start position:0% +on the unit circle that is the where is + + + align:start position:0% +on the unit circle that is the where is +it on the unit circle 1 + I 1 + I over < + + align:start position:0% +it on the unit circle 1 + I 1 + I over < + + + align:start position:0% +it on the unit circle 1 + I 1 + I over < +TK two < TK of two brings it down there + + align:start position:0% +TK two < TK of two brings it down there + + + align:start position:0% +TK two < TK of two brings it down there +there's 1 there's I divide by < TK 2 + + align:start position:0% +there's 1 there's I divide by < TK 2 + + + align:start position:0% +there's 1 there's I divide by < TK 2 +that puts us on the circle that's 1 + I + + align:start position:0% +that puts us on the circle that's 1 + I + + + align:start position:0% +that puts us on the circle that's 1 + I +over TK of 2 and here's 1 + I 1 - I over + + align:start position:0% +over TK of 2 and here's 1 + I 1 - I over + + + align:start position:0% +over TK of 2 and here's 1 + I 1 - I over +< TK of + + align:start position:0% +< TK of + + + align:start position:0% +< TK of +2 complex + + align:start position:0% +2 complex + + + align:start position:0% +2 complex +conjugates that number the con when I + + align:start position:0% +conjugates that number the con when I + + + align:start position:0% +conjugates that number the con when I +say complex conjugate that means I + + align:start position:0% +say complex conjugate that means I + + + align:start position:0% +say complex conjugate that means I +change every I to a minus I I go I flip + + align:start position:0% +change every I to a minus I I go I flip + + + align:start position:0% +change every I to a minus I I go I flip +across the real axis I want to do that + + align:start position:0% +across the real axis I want to do that + + + align:start position:0% +across the real axis I want to do that +in a minute so are there more lessons to + + align:start position:0% +in a minute so are there more lessons to + + + align:start position:0% +in a minute so are there more lessons to +see for these examples again real igen + + align:start position:0% +see for these examples again real igen + + + align:start position:0% +see for these examples again real igen +values and real IG vectors no problem + + align:start position:0% +values and real IG vectors no problem + + + align:start position:0% +values and real IG vectors no problem +here imaginary igen values here complex + + align:start position:0% +here imaginary igen values here complex + + + align:start position:0% +here imaginary igen values here complex +I values here complex I values on the + + align:start position:0% +I values here complex I values on the + + + align:start position:0% +I values here complex I values on the +circle on the circle okay and uh each of + + align:start position:0% +circle on the circle okay and uh each of + + + align:start position:0% +circle on the circle okay and uh each of +those facts that I just said about the + + align:start position:0% +those facts that I just said about the + + + align:start position:0% +those facts that I just said about the +location of the igen values it has a + + align:start position:0% +location of the igen values it has a + + + align:start position:0% +location of the igen values it has a +short proof but maybe I'll won't give + + align:start position:0% +short proof but maybe I'll won't give + + + align:start position:0% +short proof but maybe I'll won't give +the proof here it's the fact that you + + align:start position:0% +the proof here it's the fact that you + + + align:start position:0% +the proof here it's the fact that you +you want to remember kind of can I can I + + align:start position:0% +you want to remember kind of can I can I + + + align:start position:0% +you want to remember kind of can I can I +bring down again just for a moment these + + align:start position:0% +bring down again just for a moment these + + + align:start position:0% +bring down again just for a moment these +main facts real from symmetric imaginary + + align:start position:0% +main facts real from symmetric imaginary + + + align:start position:0% +main facts real from symmetric imaginary +from anti-symmetric magnitude one from + + align:start position:0% +from anti-symmetric magnitude one from + + + align:start position:0% +from anti-symmetric magnitude one from +uh + + align:start position:0% +uh + + + align:start position:0% +uh +orthogonal okay + + align:start position:0% +orthogonal okay + + + align:start position:0% +orthogonal okay +now I feel I'm talking about complex + + align:start position:0% +now I feel I'm talking about complex + + + align:start position:0% +now I feel I'm talking about complex +numbers and I really + + align:start position:0% +numbers and I really + + + align:start position:0% +numbers and I really +should + + align:start position:0% +should + + + align:start position:0% +should +say I should pay attention to that + + align:start position:0% +say I should pay attention to that + + + align:start position:0% +say I should pay attention to that +complex numbers so I have Lambda is a + + + align:start position:0% + + + + align:start position:0% + +I what do I mean by the magnitude of + + align:start position:0% +I what do I mean by the magnitude of + + + align:start position:0% +I what do I mean by the magnitude of +that number What's the magnitude of + + align:start position:0% +that number What's the magnitude of + + + align:start position:0% +that number What's the magnitude of +Lambda is a plus I here again I go along + + align:start position:0% +Lambda is a plus I here again I go along + + + align:start position:0% +Lambda is a plus I here again I go along +a up B here's the here's the + + align:start position:0% +a up B here's the here's the + + + align:start position:0% +a up B here's the here's the +Lambda the + + align:start position:0% +Lambda the + + + align:start position:0% +Lambda the +the the complex number and I want to + + align:start position:0% +the the complex number and I want to + + + align:start position:0% +the the complex number and I want to +know the length of that well everybody + + align:start position:0% +know the length of that well everybody + + + align:start position:0% +know the length of that well everybody +knows the length of that thanks thank + + align:start position:0% +knows the length of that thanks thank + + + align:start position:0% +knows the length of that thanks thank +than goodness Pythagoras lived or his + + align:start position:0% +than goodness Pythagoras lived or his + + + align:start position:0% +than goodness Pythagoras lived or his +team lived it's the square root of a^2 + + + align:start position:0% + + + + align:start position:0% + +b^2 + + align:start position:0% +b^2 + + + align:start position:0% +b^2 +and notice what that how how do I get + + align:start position:0% +and notice what that how how do I get + + + align:start position:0% +and notice what that how how do I get +that number from this one it's important + + align:start position:0% +that number from this one it's important + + + align:start position:0% +that number from this one it's important +if I multiply a plus I time a minus + + align:start position:0% +if I multiply a plus I time a minus + + + align:start position:0% +if I multiply a plus I time a minus +I so I have Lambda that's A+ ibtimes + + align:start position:0% +I so I have Lambda that's A+ ibtimes + + + align:start position:0% +I so I have Lambda that's A+ ibtimes +Lambda conjugate that's a minus IB If I + + align:start position:0% +Lambda conjugate that's a minus IB If I + + + align:start position:0% +Lambda conjugate that's a minus IB If I +multiply those that gives me A2 + b^2 so + + align:start position:0% +multiply those that gives me A2 + b^2 so + + + align:start position:0% +multiply those that gives me A2 + b^2 so +I take the square root and this is what + + align:start position:0% +I take the square root and this is what + + + align:start position:0% +I take the square root and this is what +I would call the magnitude of Lambda so + + align:start position:0% +I would call the magnitude of Lambda so + + + align:start position:0% +I would call the magnitude of Lambda so +the magnitude of a number is that + + align:start position:0% +the magnitude of a number is that + + + align:start position:0% +the magnitude of a number is that +positive length and it can be found you + + align:start position:0% +positive length and it can be found you + + + align:start position:0% +positive length and it can be found you +take the complex number times its + + align:start position:0% +take the complex number times its + + + align:start position:0% +take the complex number times its +conjugate that gives you A2 + b^2 and + + align:start position:0% +conjugate that gives you A2 + b^2 and + + + align:start position:0% +conjugate that gives you A2 + b^2 and +then take the square root + + align:start position:0% +then take the square root + + + align:start position:0% +then take the square root +basic facts about complex numbers okay + + align:start position:0% +basic facts about complex numbers okay + + + align:start position:0% +basic facts about complex numbers okay +what about complex + + align:start position:0% +what about complex + + + align:start position:0% +what about complex +vectors what is the dot product what is + + align:start position:0% +vectors what is the dot product what is + + + align:start position:0% +vectors what is the dot product what is +the correct X transpose X well it's not + + align:start position:0% +the correct X transpose X well it's not + + + align:start position:0% +the correct X transpose X well it's not +X transpose X suppose X is the vector 1 + + align:start position:0% +X transpose X suppose X is the vector 1 + + + align:start position:0% +X transpose X suppose X is the vector 1 +I as we saw we saw that as an igen + + align:start position:0% +I as we saw we saw that as an igen + + + align:start position:0% +I as we saw we saw that as an igen +Vector what's the length of that Vector + + align:start position:0% +Vector what's the length of that Vector + + + align:start position:0% +Vector what's the length of that Vector +the length of that Vector is not 1^ 2 + + + align:start position:0% +the length of that Vector is not 1^ 2 + + + + align:start position:0% +the length of that Vector is not 1^ 2 + +I i^ 2 1^ 2 + i^ 2 would be 1 + -1 would + + align:start position:0% +I i^ 2 1^ 2 + i^ 2 would be 1 + -1 would + + + align:start position:0% +I i^ 2 1^ 2 + i^ 2 would be 1 + -1 would +be zero the length of that Vector is the + + align:start position:0% +be zero the length of that Vector is the + + + align:start position:0% +be zero the length of that Vector is the +size of this squared plus the size of + + align:start position:0% +size of this squared plus the size of + + + align:start position:0% +size of this squared plus the size of +this squared square root so the length + + align:start position:0% +this squared square root so the length + + + align:start position:0% +this squared square root so the length +here we go the length of X squar the + + align:start position:0% +here we go the length of X squar the + + + align:start position:0% +here we go the length of X squar the +length of the vector squared will be the + + align:start position:0% +length of the vector squared will be the + + + align:start position:0% +length of the vector squared will be the +vector it it's it's as always it's I can + + align:start position:0% +vector it it's it's as always it's I can + + + align:start position:0% +vector it it's it's as always it's I can +find it from a from + + align:start position:0% +find it from a from + + + align:start position:0% +find it from a from +a DOT + + align:start position:0% +a DOT + + + align:start position:0% +a DOT +product but I have to take the trans the + + align:start position:0% +product but I have to take the trans the + + + align:start position:0% +product but I have to take the trans the +conjugate + + align:start position:0% +conjugate + + + align:start position:0% +conjugate +of that it's I have if I want the length + + align:start position:0% +of that it's I have if I want the length + + + align:start position:0% +of that it's I have if I want the length +of X I have to take I I would usually + + align:start position:0% +of X I have to take I I would usually + + + align:start position:0% +of X I have to take I I would usually +take X transpose X right if I have a + + align:start position:0% +take X transpose X right if I have a + + + align:start position:0% +take X transpose X right if I have a +real Vector X then I find it's do + + align:start position:0% +real Vector X then I find it's do + + + align:start position:0% +real Vector X then I find it's do +product with itself and Pythagoras tells + + align:start position:0% +product with itself and Pythagoras tells + + + align:start position:0% +product with itself and Pythagoras tells +me I have the length squared but if the + + align:start position:0% +me I have the length squared but if the + + + align:start position:0% +me I have the length squared but if the +things are complex I want Min - I * I I + + align:start position:0% +things are complex I want Min - I * I I + + + align:start position:0% +things are complex I want Min - I * I I +want to get Lambda * Lambda bar I want + + align:start position:0% +want to get Lambda * Lambda bar I want + + + align:start position:0% +want to get Lambda * Lambda bar I want +to get a positive a positive number + + align:start position:0% +to get a positive a positive number + + + align:start position:0% +to get a positive a positive number +minus I * I is + one- I * plus time I is + + align:start position:0% +minus I * I is + one- I * plus time I is + + + align:start position:0% +minus I * I is + one- I * plus time I is ++ one so I must must do + + align:start position:0% ++ one so I must must do + + + align:start position:0% ++ one so I must must do +that when I so that's really what + + align:start position:0% +that when I so that's really what + + + align:start position:0% +that when I so that's really what +orthogonal would mean orthogonal vectors + + align:start position:0% + + + + align:start position:0% + +orthogonal complex vectors mean + + align:start position:0% +orthogonal complex vectors mean + + + align:start position:0% +orthogonal complex vectors mean +orthogonal + + align:start position:0% +orthogonal + + + align:start position:0% +orthogonal +vectors mean that X conjur transpose Y + + align:start position:0% +vectors mean that X conjur transpose Y + + + align:start position:0% +vectors mean that X conjur transpose Y +is zero that + + align:start position:0% +is zero that + + + align:start position:0% +is zero that +that's that's what I mean by orthogonal + + align:start position:0% +that's that's what I mean by orthogonal + + + align:start position:0% +that's that's what I mean by orthogonal +igon vectors when those igen vectors are + + align:start position:0% +igon vectors when those igen vectors are + + + align:start position:0% +igon vectors when those igen vectors are +complex I must remember to take the + + align:start position:0% +complex I must remember to take the + + + align:start position:0% +complex I must remember to take the +complex conjugate and I also do it for + + align:start position:0% +complex conjugate and I also do it for + + + align:start position:0% +complex conjugate and I also do it for +matrices so if I have a symmetric Matrix + + align:start position:0% +matrices so if I have a symmetric Matrix + + + align:start position:0% +matrices so if I have a symmetric Matrix +s transpose S I know what that + + align:start position:0% + + + + align:start position:0% + +means but suppose s is complex suppose s + + align:start position:0% +means but suppose s is complex suppose s + + + align:start position:0% +means but suppose s is complex suppose s +is complex then for comp complex Matrix + + align:start position:0% +is complex then for comp complex Matrix + + + align:start position:0% +is complex then for comp complex Matrix +I would look at S Bar transpose equal s + + align:start position:0% +I would look at S Bar transpose equal s + + + align:start position:0% +I would look at S Bar transpose equal s +that's the that's every time I + + align:start position:0% +that's the that's every time I + + + align:start position:0% +that's the that's every time I +transpose if I have complex numbers I + + align:start position:0% +transpose if I have complex numbers I + + + align:start position:0% +transpose if I have complex numbers I +should take the complex conjugate matlb + + align:start position:0% +should take the complex conjugate matlb + + + align:start position:0% +should take the complex conjugate matlb +does it automatically Ally if you if you + + align:start position:0% +does it automatically Ally if you if you + + + align:start position:0% +does it automatically Ally if you if you +asked for X + + align:start position:0% +asked for X + + + align:start position:0% +asked for X +prime it will produce not just it'll + + align:start position:0% +prime it will produce not just it'll + + + align:start position:0% +prime it will produce not just it'll +change a column to a row with that + + align:start position:0% +change a column to a row with that + + + align:start position:0% +change a column to a row with that +transpose that Prime and it will take + + align:start position:0% +transpose that Prime and it will take + + + align:start position:0% +transpose that Prime and it will take +the complex conjugate so we we must + + align:start position:0% +the complex conjugate so we we must + + + align:start position:0% +the complex conjugate so we we must +remember always to do that yeah and in + + align:start position:0% +remember always to do that yeah and in + + + align:start position:0% +remember always to do that yeah and in +fact if s was a complex + + align:start position:0% +fact if s was a complex + + + align:start position:0% +fact if s was a complex +Matrix but it had that property Let me + + align:start position:0% +Matrix but it had that property Let me + + + align:start position:0% +Matrix but it had that property Let me +Give an example so here's a here's an S + + align:start position:0% +Give an example so here's a here's an S + + + align:start position:0% +Give an example so here's a here's an S +an example of that 1 2 I and minus I so + + align:start position:0% +an example of that 1 2 I and minus I so + + + align:start position:0% +an example of that 1 2 I and minus I so +I have a complex + + align:start position:0% +I have a complex + + + align:start position:0% +I have a complex +Matrix and if I transpose it and take + + align:start position:0% +Matrix and if I transpose it and take + + + align:start position:0% +Matrix and if I transpose it and take +complex conjugates that brings me back + + align:start position:0% +complex conjugates that brings me back + + + align:start position:0% +complex conjugates that brings me back +to S and and this is called a Hermes + + align:start position:0% + + + + align:start position:0% + +Matrix among other possible names that + + align:start position:0% +Matrix among other possible names that + + + align:start position:0% +Matrix among other possible names that +the air me was a important mathematician + + align:start position:0% +the air me was a important mathematician + + + align:start position:0% +the air me was a important mathematician +he studied this complex case and he he + + align:start position:0% +he studied this complex case and he he + + + align:start position:0% +he studied this complex case and he he +understood that to take the conjugate as + + align:start position:0% +understood that to take the conjugate as + + + align:start position:0% +understood that to take the conjugate as +well as the transpose and sometimes I + + align:start position:0% +well as the transpose and sometimes I + + + align:start position:0% +well as the transpose and sometimes I +would write it as sh in his + + align:start position:0% +would write it as sh in his + + + align:start position:0% +would write it as sh in his +honor so if if I want one symbol to do + + align:start position:0% +honor so if if I want one symbol to do + + + align:start position:0% +honor so if if I want one symbol to do +it + + align:start position:0% +it + + + align:start position:0% +it +sh uh in engineering sometimes s with a + + align:start position:0% +sh uh in engineering sometimes s with a + + + align:start position:0% +sh uh in engineering sometimes s with a +star tells me take the conjugate when + + align:start position:0% +star tells me take the conjugate when + + + align:start position:0% +star tells me take the conjugate when +you transpose a matrix okay so that's + + align:start position:0% +you transpose a matrix okay so that's + + + align:start position:0% +you transpose a matrix okay so that's +main facts about let me bring those main + + align:start position:0% +main facts about let me bring those main + + + align:start position:0% +main facts about let me bring those main +facts down again + + align:start position:0% +facts down again + + + align:start position:0% +facts down again +orthogonal igen vectors and location of + + align:start position:0% +orthogonal igen vectors and location of + + + align:start position:0% +orthogonal igen vectors and location of +igen values now I'm ready to solve + + align:start position:0% +igen values now I'm ready to solve + + + align:start position:0% +igen values now I'm ready to solve +differential equations thank you \ No newline at end of file diff --git a/_GRVq26jIHs.txt b/_GRVq26jIHs.txt new file mode 100644 index 0000000000000000000000000000000000000000..53194d8325c5c94a6067eacdbdc3f8765868383e --- /dev/null +++ b/_GRVq26jIHs.txt @@ -0,0 +1,9283 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +opencourseware under a Creative Commons + + align:start position:0% +opencourseware under a Creative Commons + + + align:start position:0% +opencourseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +okay welcome back to the uh second half + + align:start position:0% +okay welcome back to the uh second half + + + align:start position:0% +okay welcome back to the uh second half +the second lecture + + align:start position:0% +the second lecture + + + align:start position:0% +the second lecture +here we're going to take this uh + + align:start position:0% +here we're going to take this uh + + + align:start position:0% +here we're going to take this uh +beautiful example of uh + + align:start position:0% +beautiful example of uh + + + align:start position:0% +beautiful example of uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +an algorithm which the cellular + + align:start position:0% +an algorithm which the cellular + + + align:start position:0% +an algorithm which the cellular +Machinery applies to get from dn8 RNA + + align:start position:0% +Machinery applies to get from dn8 RNA + + + align:start position:0% +Machinery applies to get from dn8 RNA +protein and so a simple example where + + align:start position:0% +protein and so a simple example where + + + align:start position:0% +protein and so a simple example where +that's uh + + align:start position:0% +that's uh + + + align:start position:0% +that's uh +is incorp is incorporated into a program + + align:start position:0% +is incorp is incorporated into a program + + + align:start position:0% +is incorp is incorporated into a program +very similar to what you'd be doing on + + align:start position:0% +very similar to what you'd be doing on + + + align:start position:0% +very similar to what you'd be doing on +your palm set + + align:start position:0% +your palm set + + + align:start position:0% +your palm set +so here uh we've got it nicely color + + align:start position:0% +so here uh we've got it nicely color + + + align:start position:0% +so here uh we've got it nicely color +coded this is unrelated of course to + + align:start position:0% +coded this is unrelated of course to + + + align:start position:0% +coded this is unrelated of course to +your uh the the color coding and the + + align:start position:0% +your uh the the color coding and the + + + align:start position:0% +your uh the the color coding and the +genetic code we've been using so far but + + align:start position:0% +genetic code we've been using so far but + + + align:start position:0% +genetic code we've been using so far but +it includes the genetic code this is uh + + align:start position:0% +it includes the genetic code this is uh + + + align:start position:0% +it includes the genetic code this is uh +you can see the comments here are + + align:start position:0% +you can see the comments here are + + + align:start position:0% +you can see the comments here are +preceded by this little uh number sign + + align:start position:0% +preceded by this little uh number sign + + + align:start position:0% +preceded by this little uh number sign +We Go From The genome a DNA sequence + + align:start position:0% +We Go From The genome a DNA sequence + + + align:start position:0% +We Go From The genome a DNA sequence +uh which is a string strings are one of + + align:start position:0% +uh which is a string strings are one of + + + align:start position:0% +uh which is a string strings are one of +the things that Pearl does very well + + align:start position:0% +the things that Pearl does very well + + + align:start position:0% +the things that Pearl does very well +it's not the only string manipulation + + align:start position:0% +it's not the only string manipulation + + + align:start position:0% +it's not the only string manipulation +programming language but it's a + + align:start position:0% +programming language but it's a + + + align:start position:0% +programming language but it's a +particularly easy one and so here's how + + align:start position:0% +particularly easy one and so here's how + + + align:start position:0% +particularly easy one and so here's how +easy it is to enter a DNA sequence one + + align:start position:0% +easy it is to enter a DNA sequence one + + + align:start position:0% +easy it is to enter a DNA sequence one +of the many ways entering DNA sequence + + align:start position:0% +of the many ways entering DNA sequence + + + align:start position:0% +of the many ways entering DNA sequence +you could bring it in from a file here + + align:start position:0% +you could bring it in from a file here + + + align:start position:0% +you could bring it in from a file here +it is as part of the code + + align:start position:0% +it is as part of the code + + + align:start position:0% +it is as part of the code +you translate it sorry you transcribe it + + align:start position:0% +you translate it sorry you transcribe it + + + align:start position:0% +you translate it sorry you transcribe it +into RNA in silico here by the simple + + align:start position:0% +into RNA in silico here by the simple + + + align:start position:0% +into RNA in silico here by the simple +command where you say uh RNA sequence is + + align:start position:0% +command where you say uh RNA sequence is + + + align:start position:0% +command where you say uh RNA sequence is +uh equal the DNA sequence and then you + + align:start position:0% +uh equal the DNA sequence and then you + + + align:start position:0% +uh equal the DNA sequence and then you +substitute + + align:start position:0% +substitute + + + align:start position:0% +substitute +all the T is for use + + align:start position:0% +all the T is for use + + + align:start position:0% +all the T is for use +globally that's what this + + align:start position:0% +globally that's what this + + + align:start position:0% +globally that's what this +12th line is on slide 23. now off the + + align:start position:0% +12th line is on slide 23. now off the + + + align:start position:0% +12th line is on slide 23. now off the +side here is a reminder that there's + + align:start position:0% +side here is a reminder that there's + + + align:start position:0% +side here is a reminder that there's +really much more complicated than that + + align:start position:0% +really much more complicated than that + + + align:start position:0% +really much more complicated than that +there's all these proteins involved in + + align:start position:0% +there's all these proteins involved in + + + align:start position:0% +there's all these proteins involved in +doing it accurately and uh with + + align:start position:0% +doing it accurately and uh with + + + align:start position:0% +doing it accurately and uh with +regulation and so forth but for the sake + + align:start position:0% +regulation and so forth but for the sake + + + align:start position:0% +regulation and so forth but for the sake +of this Pearl program this is quite + + align:start position:0% +of this Pearl program this is quite + + + align:start position:0% +of this Pearl program this is quite +sufficient to get us to to an RNA + + align:start position:0% +sufficient to get us to to an RNA + + + align:start position:0% +sufficient to get us to to an RNA +sequence which we can then translate and + + align:start position:0% +sequence which we can then translate and + + + align:start position:0% +sequence which we can then translate and +hear the translation process + + align:start position:0% +hear the translation process + + + align:start position:0% +hear the translation process +um + + align:start position:0% +um + + + align:start position:0% +um +uses it start it's going to be a cycle + + align:start position:0% +uses it start it's going to be a cycle + + + align:start position:0% +uses it start it's going to be a cycle +so uh in a sense the cycle in the RNA + + align:start position:0% +so uh in a sense the cycle in the RNA + + + align:start position:0% +so uh in a sense the cycle in the RNA +sequence where you put in one nucleus at + + align:start position:0% +sequence where you put in one nucleus at + + + align:start position:0% +sequence where you put in one nucleus at +a time is is a is is all compact here + + align:start position:0% +a time is is a is is all compact here + + + align:start position:0% +a time is is a is is all compact here +it's all just substitute every t for you + + align:start position:0% +it's all just substitute every t for you + + + align:start position:0% +it's all just substitute every t for you +here we're going to have a more explicit + + align:start position:0% +here we're going to have a more explicit + + + align:start position:0% +here we're going to have a more explicit +Loop this while loop uh you can see this + + align:start position:0% +Loop this while loop uh you can see this + + + align:start position:0% +Loop this while loop uh you can see this +indented everything within the loop + + align:start position:0% +indented everything within the loop + + + align:start position:0% +indented everything within the loop +that's going to be iterated is offset a + + align:start position:0% +that's going to be iterated is offset a + + + align:start position:0% +that's going to be iterated is offset a +bit and what you're going to be doing is + + align:start position:0% +bit and what you're going to be doing is + + + align:start position:0% +bit and what you're going to be doing is +is looking in groups of three that's + + align:start position:0% +is looking in groups of three that's + + + align:start position:0% +is looking in groups of three that's +what this three is on line 17 is a + + align:start position:0% +what this three is on line 17 is a + + + align:start position:0% +what this three is on line 17 is a +is looking through the position you are + + align:start position:0% +is looking through the position you are + + + align:start position:0% +is looking through the position you are +in the RNA and taking a chunk of three + + align:start position:0% +in the RNA and taking a chunk of three + + + align:start position:0% +in the RNA and taking a chunk of three +at a time the chunkier is a substring + + align:start position:0% +at a time the chunkier is a substring + + + align:start position:0% +at a time the chunkier is a substring +that's substring and you call it you do + + align:start position:0% +that's substring and you call it you do + + + align:start position:0% +that's substring and you call it you do +a CO pull out a codon as that as that + + align:start position:0% +a CO pull out a codon as that as that + + + align:start position:0% +a CO pull out a codon as that as that +substring + + align:start position:0% +substring + + + align:start position:0% +substring +and then you do a translation so now + + align:start position:0% +and then you do a translation so now + + + align:start position:0% +and then you do a translation so now +this is a sense representing the + + align:start position:0% +this is a sense representing the + + + align:start position:0% +this is a sense representing the +modularity biology and the modularity of + + align:start position:0% +modularity biology and the modularity of + + + align:start position:0% +modularity biology and the modularity of +good programming code is you put the uh + + align:start position:0% +good programming code is you put the uh + + + align:start position:0% +good programming code is you put the uh +this whole business of translating in a + + align:start position:0% +this whole business of translating in a + + + align:start position:0% +this whole business of translating in a +separate part of the program so you + + align:start position:0% +separate part of the program so you + + + align:start position:0% +separate part of the program so you +don't have to embed the code everywhere + + align:start position:0% +don't have to embed the code everywhere + + + align:start position:0% +don't have to embed the code everywhere +that's going to be used and the + + align:start position:0% +that's going to be used and the + + + align:start position:0% +that's going to be used and the +translation here is that simple table so + + align:start position:0% +translation here is that simple table so + + + align:start position:0% +translation here is that simple table so +This subroutine SUV line 22 again + + align:start position:0% +This subroutine SUV line 22 again + + + align:start position:0% +This subroutine SUV line 22 again +indented all the code in the subroutine + + align:start position:0% +indented all the code in the subroutine + + + align:start position:0% +indented all the code in the subroutine +it goes off the bottom of the slide and + + align:start position:0% +it goes off the bottom of the slide and + + + align:start position:0% +it goes off the bottom of the slide and +down and through the floor of all the + + align:start position:0% +down and through the floor of all the + + + align:start position:0% +down and through the floor of all the +different + + align:start position:0% +different + + + align:start position:0% +different +cases now we could list 64 cases for the + + align:start position:0% +cases now we could list 64 cases for the + + + align:start position:0% +cases now we could list 64 cases for the +64 trinucleotides or we can use a more + + align:start position:0% +64 trinucleotides or we can use a more + + + align:start position:0% +64 trinucleotides or we can use a more +compact string manipulation that you can + + align:start position:0% +compact string manipulation that you can + + + align:start position:0% +compact string manipulation that you can +do in Pearl to indicate a DOT means any + + align:start position:0% +do in Pearl to indicate a DOT means any + + + align:start position:0% +do in Pearl to indicate a DOT means any +kind of uh character after G and C would + + align:start position:0% +kind of uh character after G and C would + + + align:start position:0% +kind of uh character after G and C would +return alanine so g c a c g or U and + + align:start position:0% +return alanine so g c a c g or U and + + + align:start position:0% +return alanine so g c a c g or U and +then for cysteine which has two + + align:start position:0% +then for cysteine which has two + + + align:start position:0% +then for cysteine which has two +possibilities that's four possibilities + + align:start position:0% +possibilities that's four possibilities + + + align:start position:0% +possibilities that's four possibilities +represented by that dot and cysteine has + + align:start position:0% +represented by that dot and cysteine has + + + align:start position:0% +represented by that dot and cysteine has +two possibilities it's either ugc or ugu + + align:start position:0% +two possibilities it's either ugc or ugu + + + align:start position:0% +two possibilities it's either ugc or ugu +where the vertical line means or and you + + align:start position:0% +where the vertical line means or and you + + + align:start position:0% +where the vertical line means or and you +get the idea there's a whole very + + align:start position:0% +get the idea there's a whole very + + + align:start position:0% +get the idea there's a whole very +compact syntax here for doing the + + align:start position:0% +compact syntax here for doing the + + + align:start position:0% +compact syntax here for doing the +translation + + align:start position:0% +translation + + + align:start position:0% +translation +and that's how we do + + align:start position:0% +and that's how we do + + + align:start position:0% +and that's how we do +one of the cleaner more simple + + align:start position:0% +one of the cleaner more simple + + + align:start position:0% +one of the cleaner more simple +algorithms in in computational biology + + align:start position:0% +algorithms in in computational biology + + + align:start position:0% +algorithms in in computational biology +and now I'm going to make it complicated + + align:start position:0% +and now I'm going to make it complicated + + + align:start position:0% +and now I'm going to make it complicated +again + + align:start position:0% +again + + + align:start position:0% +again +but but first the set the stage for how + + align:start position:0% +but but first the set the stage for how + + + align:start position:0% +but but first the set the stage for how +the genetic code is not Universal we + + align:start position:0% +the genetic code is not Universal we + + + align:start position:0% +the genetic code is not Universal we +have to explain by what we what we might + + align:start position:0% +have to explain by what we what we might + + + align:start position:0% +have to explain by what we what we might +mean by is being Universal this is the + + align:start position:0% +mean by is being Universal this is the + + + align:start position:0% +mean by is being Universal this is the +ultimate pedigree on this on thus + + align:start position:0% +ultimate pedigree on this on thus + + + align:start position:0% +ultimate pedigree on this on thus +slide 24 here is + + align:start position:0% +slide 24 here is + + + align:start position:0% +slide 24 here is +in principle some very simple organism + + align:start position:0% +in principle some very simple organism + + + align:start position:0% +in principle some very simple organism +possibly an rna-based organism that may + + align:start position:0% +possibly an rna-based organism that may + + + align:start position:0% +possibly an rna-based organism that may +have made a proto-ribosome that may have + + align:start position:0% +have made a proto-ribosome that may have + + + align:start position:0% +have made a proto-ribosome that may have +done protein synthesis or may have done + + align:start position:0% +done protein synthesis or may have done + + + align:start position:0% +done protein synthesis or may have done +some other chemical reaction at its pep + + align:start position:0% +some other chemical reaction at its pep + + + align:start position:0% +some other chemical reaction at its pep +at what is now peptideal transferase + + align:start position:0% +at what is now peptideal transferase + + + align:start position:0% +at what is now peptideal transferase +site something along this line is + + align:start position:0% +site something along this line is + + + align:start position:0% +site something along this line is +speculated by some biologists what was + + align:start position:0% +speculated by some biologists what was + + + align:start position:0% +speculated by some biologists what was +the common ancestor of all living + + align:start position:0% +the common ancestor of all living + + + align:start position:0% +the common ancestor of all living +species all living cells and + + align:start position:0% +species all living cells and + + + align:start position:0% +species all living cells and +uh certainly by the time we started + + align:start position:0% +uh certainly by the time we started + + + align:start position:0% +uh certainly by the time we started +getting branching of the three major + + align:start position:0% +getting branching of the three major + + + align:start position:0% +getting branching of the three major +brands bacteria the RT bacteria and the + + align:start position:0% +brands bacteria the RT bacteria and the + + + align:start position:0% +brands bacteria the RT bacteria and the +eukaryotes + + align:start position:0% +eukaryotes + + + align:start position:0% +eukaryotes +by the time we get to that point there + + align:start position:0% +by the time we get to that point there + + + align:start position:0% +by the time we get to that point there +was a a probably a ribosome set of genes + + align:start position:0% +was a a probably a ribosome set of genes + + + align:start position:0% +was a a probably a ribosome set of genes +that encodes all the proteins and rnas + + align:start position:0% +that encodes all the proteins and rnas + + + align:start position:0% +that encodes all the proteins and rnas +of the ribosome and these were shared + + align:start position:0% +of the ribosome and these were shared + + + align:start position:0% +of the ribosome and these were shared +and then at each cell division you you + + align:start position:0% +and then at each cell division you you + + + align:start position:0% +and then at each cell division you you +split off two cells were slightly + + align:start position:0% +split off two cells were slightly + + + align:start position:0% +split off two cells were slightly +different from one of the as they would + + align:start position:0% +different from one of the as they would + + + align:start position:0% +different from one of the as they would +mutate and differentiate and be selected + + align:start position:0% +mutate and differentiate and be selected + + + align:start position:0% +mutate and differentiate and be selected +they would generate the huge diversity + + align:start position:0% +they would generate the huge diversity + + + align:start position:0% +they would generate the huge diversity +of organisms which you see here + + align:start position:0% +of organisms which you see here + + + align:start position:0% +of organisms which you see here +now this is a directed acyclic graph in + + align:start position:0% +now this is a directed acyclic graph in + + + align:start position:0% +now this is a directed acyclic graph in +the sense that you don't you can't have + + align:start position:0% +the sense that you don't you can't have + + + align:start position:0% +the sense that you don't you can't have +a descendant of the in this process + + align:start position:0% +a descendant of the in this process + + + align:start position:0% +a descendant of the in this process +being an ancestor uh of of of one of its + + align:start position:0% +being an ancestor uh of of of one of its + + + align:start position:0% +being an ancestor uh of of of one of its +parents + + align:start position:0% +parents + + + align:start position:0% +parents +um so time has as an access going uh up + + align:start position:0% +um so time has as an access going uh up + + + align:start position:0% +um so time has as an access going uh up +in this case uh unlike some of the more + + align:start position:0% +in this case uh unlike some of the more + + + align:start position:0% +in this case uh unlike some of the more +physics-based or diagrams we had before + + align:start position:0% +physics-based or diagrams we had before + + + align:start position:0% +physics-based or diagrams we had before +and as you Branch out uh two existing uh + + align:start position:0% +and as you Branch out uh two existing uh + + + align:start position:0% +and as you Branch out uh two existing uh +species you see that that things like + + align:start position:0% +species you see that that things like + + + align:start position:0% +species you see that that things like +plants have actually inheritance not + + align:start position:0% +plants have actually inheritance not + + + align:start position:0% +plants have actually inheritance not +just along this direct tree-like + + align:start position:0% +just along this direct tree-like + + + align:start position:0% +just along this direct tree-like +structure but you've got more of a net + + align:start position:0% +structure but you've got more of a net + + + align:start position:0% +structure but you've got more of a net +worth like structure where some of the + + align:start position:0% +worth like structure where some of the + + + align:start position:0% +worth like structure where some of the +genomic material came in from one of the + + align:start position:0% +genomic material came in from one of the + + + align:start position:0% +genomic material came in from one of the +bacterial branches long ago and this has + + align:start position:0% +bacterial branches long ago and this has + + + align:start position:0% +bacterial branches long ago and this has +uh recently been uh put on very firm + + align:start position:0% +uh recently been uh put on very firm + + + align:start position:0% +uh recently been uh put on very firm +footing on a genomic scale in a article + + align:start position:0% +footing on a genomic scale in a article + + + align:start position:0% +footing on a genomic scale in a article +this month where the bacterial Genome of + + align:start position:0% +this month where the bacterial Genome of + + + align:start position:0% +this month where the bacterial Genome of +cyanobacteria these blue green algae + + align:start position:0% +cyanobacteria these blue green algae + + + align:start position:0% +cyanobacteria these blue green algae +that fix carbon in + + align:start position:0% +that fix carbon in + + + align:start position:0% +that fix carbon in +all the oceans and plant and the + + align:start position:0% +all the oceans and plant and the + + + align:start position:0% +all the oceans and plant and the +simplest plant that's been sequenced is + + align:start position:0% +simplest plant that's been sequenced is + + + align:start position:0% +simplest plant that's been sequenced is +arabidopsis + + align:start position:0% +arabidopsis + + + align:start position:0% +arabidopsis +um a weed and anyway the the DNA from + + align:start position:0% +um a weed and anyway the the DNA from + + + align:start position:0% +um a weed and anyway the the DNA from +the bacteria has not only gone into the + + align:start position:0% +the bacteria has not only gone into the + + + align:start position:0% +the bacteria has not only gone into the +chloroplast which is an organelle which + + align:start position:0% +chloroplast which is an organelle which + + + align:start position:0% +chloroplast which is an organelle which +has a very reduced genome but it's been + + align:start position:0% +has a very reduced genome but it's been + + + align:start position:0% +has a very reduced genome but it's been +spread through thousands of genes in the + + align:start position:0% +spread through thousands of genes in the + + + align:start position:0% +spread through thousands of genes in the +nucleus which is the major place where + + align:start position:0% +nucleus which is the major place where + + + align:start position:0% +nucleus which is the major place where +all the chromosomes are for the plants + + align:start position:0% +all the chromosomes are for the plants + + + align:start position:0% +all the chromosomes are for the plants +and so this is has has + + align:start position:0% + + + + align:start position:0% + +this possibly symbiotic relationship has + + align:start position:0% +this possibly symbiotic relationship has + + + align:start position:0% +this possibly symbiotic relationship has +resulted in a complicated inheritance + + align:start position:0% +resulted in a complicated inheritance + + + align:start position:0% +resulted in a complicated inheritance +and this is and this is not unique + + align:start position:0% +and this is and this is not unique + + + align:start position:0% +and this is and this is not unique +another one coming in from the purple + + align:start position:0% +another one coming in from the purple + + + align:start position:0% +another one coming in from the purple +bacteria has been incorporated into a + + align:start position:0% +bacteria has been incorporated into a + + + align:start position:0% +bacteria has been incorporated into a +separate membrane-bound organelle which + + align:start position:0% +separate membrane-bound organelle which + + + align:start position:0% +separate membrane-bound organelle which +provides the the ATP for for both plants + + align:start position:0% +provides the the ATP for for both plants + + + align:start position:0% +provides the the ATP for for both plants +and non-uh photosynthetic organisms + + align:start position:0% +and non-uh photosynthetic organisms + + + align:start position:0% +and non-uh photosynthetic organisms +multicellular organisms animals and uh + + align:start position:0% +multicellular organisms animals and uh + + + align:start position:0% +multicellular organisms animals and uh +and these two errors it could be there + + align:start position:0% +and these two errors it could be there + + + align:start position:0% +and these two errors it could be there +could be thousands of Errors arrows + + align:start position:0% +could be thousands of Errors arrows + + + align:start position:0% +could be thousands of Errors arrows +going over long periods of time at Deep + + align:start position:0% +going over long periods of time at Deep + + + align:start position:0% +going over long periods of time at Deep +branches and we know there are many + + align:start position:0% +branches and we know there are many + + + align:start position:0% +branches and we know there are many +interconnecting arrows in recent times + + align:start position:0% +interconnecting arrows in recent times + + + align:start position:0% +interconnecting arrows in recent times +in almost all these organisms or certain + + align:start position:0% +in almost all these organisms or certain + + + align:start position:0% +in almost all these organisms or certain +representatives from all over this tree + + align:start position:0% +representatives from all over this tree + + + align:start position:0% +representatives from all over this tree +can take up DNA in various ways can even + + align:start position:0% +can take up DNA in various ways can even + + + align:start position:0% +can take up DNA in various ways can even +mate with organisms of various species + + align:start position:0% +mate with organisms of various species + + + align:start position:0% +mate with organisms of various species +and exchange DNA and incorporate it and + + align:start position:0% +and exchange DNA and incorporate it and + + + align:start position:0% +and exchange DNA and incorporate it and +so it's not this simple tree but it is + + align:start position:0% +so it's not this simple tree but it is + + + align:start position:0% +so it's not this simple tree but it is +certainly + + align:start position:0% +certainly + + + align:start position:0% +certainly +um + + align:start position:0% + + + + align:start position:0% + +going forward in time it is directed in + + align:start position:0% +going forward in time it is directed in + + + align:start position:0% +going forward in time it is directed in +a cyclic in that regard + + align:start position:0% + + + + align:start position:0% + +so how many living species are there so + + align:start position:0% +so how many living species are there so + + + align:start position:0% +so how many living species are there so +we're building to the point connecting + + align:start position:0% +we're building to the point connecting + + + align:start position:0% +we're building to the point connecting +back to the central dogma of how many + + align:start position:0% +back to the central dogma of how many + + + align:start position:0% +back to the central dogma of how many +different genetic codes are there so we + + align:start position:0% +different genetic codes are there so we + + + align:start position:0% +different genetic codes are there so we +need to know how many species there are + + align:start position:0% +need to know how many species there are + + + align:start position:0% +need to know how many species there are +if you take a gram of you know some + + align:start position:0% +if you take a gram of you know some + + + align:start position:0% +if you take a gram of you know some +thumbnail of uh + + align:start position:0% +thumbnail of uh + + + align:start position:0% +thumbnail of uh +uh soil from any of a variety of + + align:start position:0% +uh soil from any of a variety of + + + align:start position:0% +uh soil from any of a variety of +different soils that have been tested + + align:start position:0% +different soils that have been tested + + + align:start position:0% +different soils that have been tested +you can find about 5 000 bacterial + + align:start position:0% +you can find about 5 000 bacterial + + + align:start position:0% +you can find about 5 000 bacterial +species well what does it mean to be a + + align:start position:0% +species well what does it mean to be a + + + align:start position:0% +species well what does it mean to be a +species in animals it typically means + + align:start position:0% +species in animals it typically means + + + align:start position:0% +species in animals it typically means +that they don't produce fertile + + align:start position:0% +that they don't produce fertile + + + align:start position:0% +that they don't produce fertile +offspring when they interbreed to + + align:start position:0% +offspring when they interbreed to + + + align:start position:0% +offspring when they interbreed to +different species but they're books full + + align:start position:0% +different species but they're books full + + + align:start position:0% +different species but they're books full +of exceptions of this even in animals + + align:start position:0% +of exceptions of this even in animals + + + align:start position:0% +of exceptions of this even in animals +and bacteria of course where they + + align:start position:0% +and bacteria of course where they + + + align:start position:0% +and bacteria of course where they +exchange DNA all over the place as I + + align:start position:0% +exchange DNA all over the place as I + + + align:start position:0% +exchange DNA all over the place as I +said it breaks down even more so a + + align:start position:0% +said it breaks down even more so a + + + align:start position:0% +said it breaks down even more so a +working definition that's many + + align:start position:0% +working definition that's many + + + align:start position:0% +working definition that's many +biologists adopt is that if two + + align:start position:0% +biologists adopt is that if two + + + align:start position:0% +biologists adopt is that if two +microbial species share 20 percent of + + align:start position:0% +microbial species share 20 percent of + + + align:start position:0% +microbial species share 20 percent of +their DNA if you take their DNA align it + + align:start position:0% +their DNA if you take their DNA align it + + + align:start position:0% +their DNA if you take their DNA align it +by algorithms such as the ones we will + + align:start position:0% +by algorithms such as the ones we will + + + align:start position:0% +by algorithms such as the ones we will +be using this course and you find that + + align:start position:0% +be using this course and you find that + + + align:start position:0% +be using this course and you find that +70 of the base pairs are conserved then + + align:start position:0% +70 of the base pairs are conserved then + + + align:start position:0% +70 of the base pairs are conserved then +they're the same species otherwise + + align:start position:0% +they're the same species otherwise + + + align:start position:0% +they're the same species otherwise +they're different species + + align:start position:0% +they're different species + + + align:start position:0% +they're different species +and uh there are millions of + + align:start position:0% +and uh there are millions of + + + align:start position:0% +and uh there are millions of +non-microbial species many of which + + align:start position:0% +non-microbial species many of which + + + align:start position:0% +non-microbial species many of which +harbor microbial species uh this number + + align:start position:0% +harbor microbial species uh this number + + + align:start position:0% +harbor microbial species uh this number +is dropping slightly because of our + + align:start position:0% +is dropping slightly because of our + + + align:start position:0% +is dropping slightly because of our +um + + align:start position:0% +um + + + align:start position:0% +um +you know our inability to + + align:start position:0% +you know our inability to + + + align:start position:0% +you know our inability to +restrain our growth and and other + + align:start position:0% +restrain our growth and and other + + + align:start position:0% +restrain our growth and and other +activities that cause speciation species + + align:start position:0% +activities that cause speciation species + + + align:start position:0% +activities that cause speciation species +Extinction + + align:start position:0% +Extinction + + + align:start position:0% +Extinction +um + + align:start position:0% +um + + + align:start position:0% +um +and uh the number of whole genomes is + + align:start position:0% +and uh the number of whole genomes is + + + align:start position:0% +and uh the number of whole genomes is +getting closer to a hundred and the + + align:start position:0% +getting closer to a hundred and the + + + align:start position:0% +getting closer to a hundred and the +number of the pipeline is is probably + + align:start position:0% +number of the pipeline is is probably + + + align:start position:0% +number of the pipeline is is probably +going is in is 600 or so maybe in the + + align:start position:0% +going is in is 600 or so maybe in the + + + align:start position:0% +going is in is 600 or so maybe in the +thousands with new technologies and + + align:start position:0% +thousands with new technologies and + + + align:start position:0% +thousands with new technologies and +there's over 80 000 species + + align:start position:0% +there's over 80 000 species + + + align:start position:0% +there's over 80 000 species +defined by one or more nucleic acid + + align:start position:0% +defined by one or more nucleic acid + + + align:start position:0% +defined by one or more nucleic acid +sequences in the ncbi National Center + + align:start position:0% +sequences in the ncbi National Center + + + align:start position:0% +sequences in the ncbi National Center +for bioinformatics which is the one of + + align:start position:0% +for bioinformatics which is the one of + + + align:start position:0% +for bioinformatics which is the one of +the three major nucleic acid databases + + align:start position:0% +the three major nucleic acid databases + + + align:start position:0% +the three major nucleic acid databases +in the world + + align:start position:0% + + + + align:start position:0% + +why do we study more than one species + + align:start position:0% +why do we study more than one species + + + align:start position:0% +why do we study more than one species +the comparison between species allows + + align:start position:0% +the comparison between species allows + + + align:start position:0% +the comparison between species allows +subtle and not so subtle + + align:start position:0% +subtle and not so subtle + + + align:start position:0% +subtle and not so subtle +analyzes of what is what are the + + align:start position:0% +analyzes of what is what are the + + + align:start position:0% +analyzes of what is what are the +important positions to stay constant + + align:start position:0% +important positions to stay constant + + + align:start position:0% +important positions to stay constant +because they provide some very + + align:start position:0% +because they provide some very + + + align:start position:0% +because they provide some very +fundamental biochemical activity but + + align:start position:0% +fundamental biochemical activity but + + + align:start position:0% +fundamental biochemical activity but +what are the important ones to vary + + align:start position:0% +what are the important ones to vary + + + align:start position:0% +what are the important ones to vary +because they provide some important + + align:start position:0% +because they provide some important + + + align:start position:0% +because they provide some important +variants for example escaping immune + + align:start position:0% +variants for example escaping immune + + + align:start position:0% +variants for example escaping immune +surveillance and so on so there's + + align:start position:0% +surveillance and so on so there's + + + align:start position:0% +surveillance and so on so there's +reasons to be constant reason to be + + align:start position:0% +reasons to be constant reason to be + + + align:start position:0% +reasons to be constant reason to be +variable and reasons to be neutral + + align:start position:0% +variable and reasons to be neutral + + + align:start position:0% +variable and reasons to be neutral +so let's now apply it let's go back now + + align:start position:0% +so let's now apply it let's go back now + + + align:start position:0% +so let's now apply it let's go back now +apply this to the genetic code this + + align:start position:0% +apply this to the genetic code this + + + align:start position:0% +apply this to the genetic code this +particularly simple and elegant nearly + + align:start position:0% +particularly simple and elegant nearly + + + align:start position:0% +particularly simple and elegant nearly +universal code + + align:start position:0% +universal code + + + align:start position:0% +universal code +this is how genetic codes are + + align:start position:0% +this is how genetic codes are + + + align:start position:0% +this is how genetic codes are +represented in CBI one of the ways and + + align:start position:0% +represented in CBI one of the ways and + + + align:start position:0% +represented in CBI one of the ways and +here the three bases of the codon faces + + align:start position:0% +here the three bases of the codon faces + + + align:start position:0% +here the three bases of the codon faces +one two and three remember we said that + + align:start position:0% +one two and three remember we said that + + + align:start position:0% +one two and three remember we said that +uu was phenylalanine encoded by DNA TTT + + align:start position:0% +uu was phenylalanine encoded by DNA TTT + + + align:start position:0% +uu was phenylalanine encoded by DNA TTT +so going down from the top on the + + align:start position:0% +so going down from the top on the + + + align:start position:0% +so going down from the top on the +leftmost column it's TTT single letter + + align:start position:0% +leftmost column it's TTT single letter + + + align:start position:0% +leftmost column it's TTT single letter +code f for phenylalanine so the amino + + align:start position:0% +code f for phenylalanine so the amino + + + align:start position:0% +code f for phenylalanine so the amino +acids go along the bottom uh + + align:start position:0% +acids go along the bottom uh + + + align:start position:0% +acids go along the bottom uh +row of this of this table and you can + + align:start position:0% +row of this of this table and you can + + + align:start position:0% +row of this of this table and you can +see this that all the amino acids are + + align:start position:0% +see this that all the amino acids are + + + align:start position:0% +see this that all the amino acids are +represented stars represent stop codons + + align:start position:0% +represented stars represent stop codons + + + align:start position:0% +represented stars represent stop codons +which are not recognized by transfer + + align:start position:0% +which are not recognized by transfer + + + align:start position:0% +which are not recognized by transfer +rnas but by proteins called release + + align:start position:0% +rnas but by proteins called release + + + align:start position:0% +rnas but by proteins called release +factors that simulate the functions of + + align:start position:0% +factors that simulate the functions of + + + align:start position:0% +factors that simulate the functions of +Transfer RNA and cause the release of + + align:start position:0% +Transfer RNA and cause the release of + + + align:start position:0% +Transfer RNA and cause the release of +this Con cyclic uh incorporation of + + align:start position:0% +this Con cyclic uh incorporation of + + + align:start position:0% +this Con cyclic uh incorporation of +amino acids into polypeptides + + align:start position:0% +amino acids into polypeptides + + + align:start position:0% +amino acids into polypeptides +um + + align:start position:0% +um + + + align:start position:0% +um +now this is the standard code + + align:start position:0% +now this is the standard code + + + align:start position:0% +now this is the standard code +so-called where you have one methionine + + align:start position:0% +so-called where you have one methionine + + + align:start position:0% +so-called where you have one methionine +here in the middle here encoded by + + align:start position:0% +here in the middle here encoded by + + + align:start position:0% +here in the middle here encoded by +atg and three spot codons and all the + + align:start position:0% +atg and three spot codons and all the + + + align:start position:0% +atg and three spot codons and all the +rest + + align:start position:0% +rest + + + align:start position:0% +rest +here's where it gets complicated there + + align:start position:0% +here's where it gets complicated there + + + align:start position:0% +here's where it gets complicated there +are over 22 different uh genetic codes + + align:start position:0% +are over 22 different uh genetic codes + + + align:start position:0% +are over 22 different uh genetic codes +some of the changes from the standard + + align:start position:0% +some of the changes from the standard + + + align:start position:0% +some of the changes from the standard +code are indicated here in blue + + align:start position:0% +code are indicated here in blue + + + align:start position:0% +code are indicated here in blue +you have here for example for the + + align:start position:0% +you have here for example for the + + + align:start position:0% +you have here for example for the +mitochondrial code this is the code + + align:start position:0% +mitochondrial code this is the code + + + align:start position:0% +mitochondrial code this is the code +actually used in every cell in your body + + align:start position:0% +actually used in every cell in your body + + + align:start position:0% +actually used in every cell in your body +for the subset of the cell that is the + + align:start position:0% +for the subset of the cell that is the + + + align:start position:0% +for the subset of the cell that is the +PowerHouse that makes ATP the + + align:start position:0% +PowerHouse that makes ATP the + + + align:start position:0% +PowerHouse that makes ATP the +mitochondria that we talked about before + + align:start position:0% +mitochondria that we talked about before + + + align:start position:0% +mitochondria that we talked about before +which was part of the vertical + + align:start position:0% +which was part of the vertical + + + align:start position:0% +which was part of the vertical +transmission the horizontal transmission + + align:start position:0% +transmission the horizontal transmission + + + align:start position:0% +transmission the horizontal transmission +of information from purple bacteria long + + align:start position:0% +of information from purple bacteria long + + + align:start position:0% +of information from purple bacteria long +ago well anyway the stop to normal stop + + align:start position:0% +ago well anyway the stop to normal stop + + + align:start position:0% +ago well anyway the stop to normal stop +codon is now tryptophan abbreviated w + + align:start position:0% +codon is now tryptophan abbreviated w + + + align:start position:0% +codon is now tryptophan abbreviated w +um there's an extra methionine and + + align:start position:0% +um there's an extra methionine and + + + align:start position:0% +um there's an extra methionine and +there's two extra stop codons which are + + align:start position:0% +there's two extra stop codons which are + + + align:start position:0% +there's two extra stop codons which are +replacing what would have been an + + align:start position:0% +replacing what would have been an + + + align:start position:0% +replacing what would have been an +Arginine in standard code and you can + + align:start position:0% +Arginine in standard code and you can + + + align:start position:0% +Arginine in standard code and you can +see there's little Blues all over the + + align:start position:0% +see there's little Blues all over the + + + align:start position:0% +see there's little Blues all over the +place changes in the number of the where + + align:start position:0% +place changes in the number of the where + + + align:start position:0% +place changes in the number of the where +you can start the start sites are + + align:start position:0% +you can start the start sites are + + + align:start position:0% +you can start the start sites are +indicated by three + + align:start position:0% +indicated by three + + + align:start position:0% +indicated by three +uh one to three starts in the standard + + align:start position:0% +uh one to three starts in the standard + + + align:start position:0% +uh one to three starts in the standard +code and uh + + align:start position:0% +code and uh + + + align:start position:0% +code and uh +when you talk about the starts you start + + align:start position:0% +when you talk about the starts you start + + + align:start position:0% +when you talk about the starts you start +getting into uh + + align:start position:0% +getting into uh + + + align:start position:0% +getting into uh +uh what's the + + align:start position:0% +uh what's the + + + align:start position:0% +uh what's the +how much do you favor that particular + + align:start position:0% +how much do you favor that particular + + + align:start position:0% +how much do you favor that particular +start what other signals are required to + + align:start position:0% +start what other signals are required to + + + align:start position:0% +start what other signals are required to +start at that particular position it's + + align:start position:0% +start at that particular position it's + + + align:start position:0% +start at that particular position it's +not as simple as just having an atg + + align:start position:0% +not as simple as just having an atg + + + align:start position:0% +not as simple as just having an atg +trynucleotide to get a start of protein + + align:start position:0% +trynucleotide to get a start of protein + + + align:start position:0% +trynucleotide to get a start of protein +synthesis you need other nucleic acid + + align:start position:0% +synthesis you need other nucleic acid + + + align:start position:0% +synthesis you need other nucleic acid +components + + align:start position:0% +components + + + align:start position:0% +components +anyway you can deal with it's still it's + + align:start position:0% +anyway you can deal with it's still it's + + + align:start position:0% +anyway you can deal with it's still it's +a slightly more complicated algorithm + + align:start position:0% +a slightly more complicated algorithm + + + align:start position:0% +a slightly more complicated algorithm +you have to know exactly what organelle + + align:start position:0% +you have to know exactly what organelle + + + align:start position:0% +you have to know exactly what organelle +and what organism you're dealing with + + align:start position:0% +and what organism you're dealing with + + + align:start position:0% +and what organism you're dealing with +but you can apply the same kind of + + align:start position:0% +but you can apply the same kind of + + + align:start position:0% +but you can apply the same kind of +computer codes that we had a couple of + + align:start position:0% +computer codes that we had a couple of + + + align:start position:0% +computer codes that we had a couple of +slides back + + align:start position:0% +slides back + + + align:start position:0% +slides back +but now we get into even more + + align:start position:0% +but now we get into even more + + + align:start position:0% +but now we get into even more +complicated and part of the reason I'm + + align:start position:0% +complicated and part of the reason I'm + + + align:start position:0% +complicated and part of the reason I'm +showing you this early on some of these + + align:start position:0% +showing you this early on some of these + + + align:start position:0% +showing you this early on some of these +things would not be in your textbooks + + align:start position:0% +things would not be in your textbooks + + + align:start position:0% +things would not be in your textbooks +for the first biology course and they + + align:start position:0% +for the first biology course and they + + + align:start position:0% +for the first biology course and they +would not be in a first computational + + align:start position:0% +would not be in a first computational + + + align:start position:0% +would not be in a first computational +Biology + + align:start position:0% +Biology + + + align:start position:0% +Biology +lecture or two + + align:start position:0% +lecture or two + + + align:start position:0% +lecture or two +but I do this so that you'll have a + + align:start position:0% +but I do this so that you'll have a + + + align:start position:0% +but I do this so that you'll have a +healthy distrust of everything that you + + align:start position:0% +healthy distrust of everything that you + + + align:start position:0% +healthy distrust of everything that you +read and everything you hear including + + align:start position:0% +read and everything you hear including + + + align:start position:0% +read and everything you hear including +everything you hear from me + + align:start position:0% +everything you hear from me + + + align:start position:0% +everything you hear from me +um + + align:start position:0% +um + + + align:start position:0% +um +and this should really make you distrust + + align:start position:0% +and this should really make you distrust + + + align:start position:0% +and this should really make you distrust +the genetic code because what these + + align:start position:0% +the genetic code because what these + + + align:start position:0% +the genetic code because what these +ribosomes do in this particular sequence + + align:start position:0% +ribosomes do in this particular sequence + + + align:start position:0% +ribosomes do in this particular sequence +which has been well documented + + align:start position:0% +which has been well documented + + + align:start position:0% +which has been well documented +um eight years ago is that they will hop + + align:start position:0% +um eight years ago is that they will hop + + + align:start position:0% +um eight years ago is that they will hop +over 50 nucleotides they're not hopping + + align:start position:0% +over 50 nucleotides they're not hopping + + + align:start position:0% +over 50 nucleotides they're not hopping +they're not going three nucleotides at a + + align:start position:0% +they're not going three nucleotides at a + + + align:start position:0% +they're not going three nucleotides at a +time as they should in fact it's not + + align:start position:0% +time as they should in fact it's not + + + align:start position:0% +time as they should in fact it's not +even an integral multiple of three + + align:start position:0% +even an integral multiple of three + + + align:start position:0% +even an integral multiple of three +nucleotides it is literally coming to a + + align:start position:0% +nucleotides it is literally coming to a + + + align:start position:0% +nucleotides it is literally coming to a +stop codon and rather than stopping + + align:start position:0% +stop codon and rather than stopping + + + align:start position:0% +stop codon and rather than stopping +if it has just the right sequence + + align:start position:0% +if it has just the right sequence + + + align:start position:0% +if it has just the right sequence +context including this complicated + + align:start position:0% +context including this complicated + + + align:start position:0% +context including this complicated +RNA secondary structure called a pseudo + + align:start position:0% +RNA secondary structure called a pseudo + + + align:start position:0% +RNA secondary structure called a pseudo +knot the RNA folds up the messenger + + align:start position:0% +knot the RNA folds up the messenger + + + align:start position:0% +knot the RNA folds up the messenger +which really should just be a messenger + + align:start position:0% +which really should just be a messenger + + + align:start position:0% +which really should just be a messenger +which you know computers should just be + + align:start position:0% +which you know computers should just be + + + align:start position:0% +which you know computers should just be +recognizing uh or the biological + + align:start position:0% +recognizing uh or the biological + + + align:start position:0% +recognizing uh or the biological +biochemical computer is just the + + align:start position:0% +biochemical computer is just the + + + align:start position:0% +biochemical computer is just the +ribosome should be recognizing three + + align:start position:0% +ribosome should be recognizing three + + + align:start position:0% +ribosome should be recognizing three +nucleotides at a time instead it's + + align:start position:0% +nucleotides at a time instead it's + + + align:start position:0% +nucleotides at a time instead it's +recognizing a morphology this thing + + align:start position:0% +recognizing a morphology this thing + + + align:start position:0% +recognizing a morphology this thing +folds up and no longer is informational + + align:start position:0% +folds up and no longer is informational + + + align:start position:0% +folds up and no longer is informational +molecule it is a morphological uh + + align:start position:0% +molecule it is a morphological uh + + + align:start position:0% +molecule it is a morphological uh +recognition element anyway when it finds + + align:start position:0% +recognition element anyway when it finds + + + align:start position:0% +recognition element anyway when it finds +that it skips over 50 nucleotides skips + + align:start position:0% +that it skips over 50 nucleotides skips + + + align:start position:0% +that it skips over 50 nucleotides skips +over the stop codon and makes a + + align:start position:0% +over the stop codon and makes a + + + align:start position:0% +over the stop codon and makes a +perfectly otherwise perfectly normal + + align:start position:0% +perfectly otherwise perfectly normal + + + align:start position:0% +perfectly otherwise perfectly normal +protein + + align:start position:0% +protein + + + align:start position:0% +protein +so + + align:start position:0% +so + + + align:start position:0% +so +don't even trust Dogma especially don't + + align:start position:0% +don't even trust Dogma especially don't + + + align:start position:0% +don't even trust Dogma especially don't +trust Dogma central dogma included okay + + align:start position:0% +trust Dogma central dogma included okay + + + align:start position:0% +trust Dogma central dogma included okay +plenty of exam uh plenty of counter + + align:start position:0% +plenty of exam uh plenty of counter + + + align:start position:0% +plenty of exam uh plenty of counter +examples now we're going to move from + + align:start position:0% +examples now we're going to move from + + + align:start position:0% +examples now we're going to move from +this very very simple + + align:start position:0% +this very very simple + + + align:start position:0% +this very very simple +um + + align:start position:0% +um + + + align:start position:0% +um +example of an algorithm where we can + + align:start position:0% +example of an algorithm where we can + + + align:start position:0% +example of an algorithm where we can +model proteins directly from the nucleic + + align:start position:0% +model proteins directly from the nucleic + + + align:start position:0% +model proteins directly from the nucleic +acids that come out of DNA sequences + + align:start position:0% +acids that come out of DNA sequences + + + align:start position:0% +acids that come out of DNA sequences +wholesale we now want to ask how do we + + align:start position:0% +wholesale we now want to ask how do we + + + align:start position:0% +wholesale we now want to ask how do we +get the more quantitative data which + + align:start position:0% +get the more quantitative data which + + + align:start position:0% +get the more quantitative data which +comes out of functional genomics rather + + align:start position:0% +comes out of functional genomics rather + + + align:start position:0% +comes out of functional genomics rather +than classical sequence sequencing how + + align:start position:0% +than classical sequence sequencing how + + + align:start position:0% +than classical sequence sequencing how +do we get that into qualitative models + + align:start position:0% +do we get that into qualitative models + + + align:start position:0% +do we get that into qualitative models +and then get the qualitative models then + + align:start position:0% +and then get the qualitative models then + + + align:start position:0% +and then get the qualitative models then +repopulated with additional quantitative + + align:start position:0% +repopulated with additional quantitative + + + align:start position:0% +repopulated with additional quantitative +data to make a full model + + align:start position:0% +data to make a full model + + + align:start position:0% +data to make a full model +now in order to say came up earlier as a + + align:start position:0% +now in order to say came up earlier as a + + + align:start position:0% +now in order to say came up earlier as a +question what you know what is the + + align:start position:0% +question what you know what is the + + + align:start position:0% +question what you know what is the +function of a gene product + + align:start position:0% +function of a gene product + + + align:start position:0% +function of a gene product +um + + align:start position:0% +um + + + align:start position:0% +um +we go we dip into + + align:start position:0% +we go we dip into + + + align:start position:0% +we go we dip into +qualitative statements which are made in + + align:start position:0% +qualitative statements which are made in + + + align:start position:0% +qualitative statements which are made in +the literature + + align:start position:0% +the literature + + + align:start position:0% +the literature +which have various ways of representing + + align:start position:0% +which have various ways of representing + + + align:start position:0% +which have various ways of representing +the evidence for this some of them very + + align:start position:0% +the evidence for this some of them very + + + align:start position:0% +the evidence for this some of them very +convoluted arguments some of them + + align:start position:0% +convoluted arguments some of them + + + align:start position:0% +convoluted arguments some of them +um very casual but when they're when + + align:start position:0% +um very casual but when they're when + + + align:start position:0% +um very casual but when they're when +they are when an attempt is made to put + + align:start position:0% +they are when an attempt is made to put + + + align:start position:0% +they are when an attempt is made to put +these into a database or a data + + align:start position:0% +these into a database or a data + + + align:start position:0% +these into a database or a data +structure as representative gross + + align:start position:0% +structure as representative gross + + + align:start position:0% +structure as representative gross +oversimplification of the literature + + align:start position:0% +oversimplification of the literature + + + align:start position:0% +oversimplification of the literature +this is what often comes out something + + align:start position:0% +this is what often comes out something + + + align:start position:0% +this is what often comes out something +like this where you'll have a + + align:start position:0% +like this where you'll have a + + + align:start position:0% +like this where you'll have a +hierarchical table here I've blown up + + align:start position:0% +hierarchical table here I've blown up + + + align:start position:0% +hierarchical table here I've blown up +one of the levels of the hierarchy you + + align:start position:0% +one of the levels of the hierarchy you + + + align:start position:0% +one of the levels of the hierarchy you +can think of it as a list where the list + + align:start position:0% +can think of it as a list where the list + + + align:start position:0% +can think of it as a list where the list +may not be in a particularly logical + + align:start position:0% +may not be in a particularly logical + + + align:start position:0% +may not be in a particularly logical +order but the hierarchy is so that under + + align:start position:0% +order but the hierarchy is so that under + + + align:start position:0% +order but the hierarchy is so that under +metabolism would be some covalent change + + align:start position:0% +metabolism would be some covalent change + + + align:start position:0% +metabolism would be some covalent change +in substrates which enzymes would would + + align:start position:0% +in substrates which enzymes would would + + + align:start position:0% +in substrates which enzymes would would +catalyze and then you have information + + align:start position:0% +catalyze and then you have information + + + align:start position:0% +catalyze and then you have information +transfer we've been talking about like + + align:start position:0% +transfer we've been talking about like + + + align:start position:0% +transfer we've been talking about like +the ribose the DNA to RNA protein these + + align:start position:0% +the ribose the DNA to RNA protein these + + + align:start position:0% +the ribose the DNA to RNA protein these +biopolymers regulation of information + + align:start position:0% +biopolymers regulation of information + + + align:start position:0% +biopolymers regulation of information +transfer or of metabolism would be have + + align:start position:0% +transfer or of metabolism would be have + + + align:start position:0% +transfer or of metabolism would be have +all these four subheadings type of + + align:start position:0% +all these four subheadings type of + + + align:start position:0% +all these four subheadings type of +Regulation trigger and so on and then + + align:start position:0% +Regulation trigger and so on and then + + + align:start position:0% +Regulation trigger and so on and then +transport in these various other + + align:start position:0% +transport in these various other + + + align:start position:0% +transport in these various other +processes each of these functions such + + align:start position:0% +processes each of these functions such + + + align:start position:0% +processes each of these functions such +as illustrated by these references here + + align:start position:0% +as illustrated by these references here + + + align:start position:0% +as illustrated by these references here +can be used in a in a way of connecting + + align:start position:0% +can be used in a in a way of connecting + + + align:start position:0% +can be used in a in a way of connecting +all the new information we get to some + + align:start position:0% +all the new information we get to some + + + align:start position:0% +all the new information we get to some +sort of systematic + + align:start position:0% +sort of systematic + + + align:start position:0% +sort of systematic +uh best + + align:start position:0% +uh best + + + align:start position:0% +uh best +guess best estimate of encapsulation of + + align:start position:0% +guess best estimate of encapsulation of + + + align:start position:0% +guess best estimate of encapsulation of +the literature another example of this + + align:start position:0% +the literature another example of this + + + align:start position:0% +the literature another example of this +in addition to the the mips for yeast is + + align:start position:0% +in addition to the the mips for yeast is + + + align:start position:0% +in addition to the the mips for yeast is +Gene ontology which is uh derived from + + align:start position:0% +Gene ontology which is uh derived from + + + align:start position:0% +Gene ontology which is uh derived from +the word ontology or nature of being + + align:start position:0% +the word ontology or nature of being + + + align:start position:0% +the word ontology or nature of being +and the objective of Geo for + + align:start position:0% +and the objective of Geo for + + + align:start position:0% +and the objective of Geo for +abbreviation of Gene ontology is to + + align:start position:0% +abbreviation of Gene ontology is to + + + align:start position:0% +abbreviation of Gene ontology is to +provide a controlled vocabulary + + align:start position:0% +provide a controlled vocabulary + + + align:start position:0% +provide a controlled vocabulary +um + + align:start position:0% +um + + + align:start position:0% +um +my vocabulary during this lecture has + + align:start position:0% +my vocabulary during this lecture has + + + align:start position:0% +my vocabulary during this lecture has +been uncontrolled okay as you've + + align:start position:0% +been uncontrolled okay as you've + + + align:start position:0% +been uncontrolled okay as you've +probably guessed uh but when you start + + align:start position:0% +probably guessed uh but when you start + + + align:start position:0% +probably guessed uh but when you start +talking about I have pointed out the + + align:start position:0% +talking about I have pointed out the + + + align:start position:0% +talking about I have pointed out the +problems that you get into when you + + align:start position:0% +problems that you get into when you + + + align:start position:0% +problems that you get into when you +casually refer to gene expression when + + align:start position:0% +casually refer to gene expression when + + + align:start position:0% +casually refer to gene expression when +you really mean RNA expression and refer + + align:start position:0% +you really mean RNA expression and refer + + + align:start position:0% +you really mean RNA expression and refer +to genes as protein coding entities when + + align:start position:0% +to genes as protein coding entities when + + + align:start position:0% +to genes as protein coding entities when +you really mean protein or RNA encoding + + align:start position:0% +you really mean protein or RNA encoding + + + align:start position:0% +you really mean protein or RNA encoding +entities that process of being more + + align:start position:0% +entities that process of being more + + + align:start position:0% +entities that process of being more +precise about our use of terms at least + + align:start position:0% +precise about our use of terms at least + + + align:start position:0% +precise about our use of terms at least +when we're communicating with computers + + align:start position:0% +when we're communicating with computers + + + align:start position:0% +when we're communicating with computers +is very important if we communicate with + + align:start position:0% +is very important if we communicate with + + + align:start position:0% +is very important if we communicate with +each other you guys will give me a + + align:start position:0% +each other you guys will give me a + + + align:start position:0% +each other you guys will give me a +little slack some of you and uh but the + + align:start position:0% +little slack some of you and uh but the + + + align:start position:0% +little slack some of you and uh but the +computers won't they will misinterpret + + align:start position:0% +computers won't they will misinterpret + + + align:start position:0% +computers won't they will misinterpret +every chance they get and uh so that's + + align:start position:0% +every chance they get and uh so that's + + + align:start position:0% +every chance they get and uh so that's +what control vocabulary is all about and + + align:start position:0% +what control vocabulary is all about and + + + align:start position:0% +what control vocabulary is all about and +you'll have three different they've the + + align:start position:0% +you'll have three different they've the + + + align:start position:0% +you'll have three different they've the +inventors of Gene ontology classif have + + align:start position:0% +inventors of Gene ontology classif have + + + align:start position:0% +inventors of Gene ontology classif have +a hierarchy including molecular function + + align:start position:0% +a hierarchy including molecular function + + + align:start position:0% +a hierarchy including molecular function +biological processes in a cellular + + align:start position:0% +biological processes in a cellular + + + align:start position:0% +biological processes in a cellular +component which will expand upon in the + + align:start position:0% +component which will expand upon in the + + + align:start position:0% +component which will expand upon in the +next slide + + align:start position:0% + + + + align:start position:0% + +cautionary note whenever you do modeling + + align:start position:0% +cautionary note whenever you do modeling + + + align:start position:0% +cautionary note whenever you do modeling +or you will be assumptions in this case + + align:start position:0% +or you will be assumptions in this case + + + align:start position:0% +or you will be assumptions in this case +some of the assumptions exclude vast + + align:start position:0% +some of the assumptions exclude vast + + + align:start position:0% +some of the assumptions exclude vast +parts of biology which are listed here + + align:start position:0% +parts of biology which are listed here + + + align:start position:0% +parts of biology which are listed here +as part of their documentation they have + + align:start position:0% +as part of their documentation they have + + + align:start position:0% +as part of their documentation they have +things that are not modeled in the gene + + align:start position:0% +things that are not modeled in the gene + + + align:start position:0% +things that are not modeled in the gene +ontology or domain structure in a + + align:start position:0% +ontology or domain structure in a + + + align:start position:0% +ontology or domain structure in a +three-dimensional structure which + + align:start position:0% +three-dimensional structure which + + + align:start position:0% +three-dimensional structure which +obviously has played a big role in the + + align:start position:0% +obviously has played a big role in the + + + align:start position:0% +obviously has played a big role in the +in the two lectures so far + + align:start position:0% +in the two lectures so far + + + align:start position:0% +in the two lectures so far +the evolution + + align:start position:0% +the evolution + + + align:start position:0% +the evolution +and uh gene expression these we've + + align:start position:0% +and uh gene expression these we've + + + align:start position:0% +and uh gene expression these we've +already talked about the phylogenetic + + align:start position:0% +already talked about the phylogenetic + + + align:start position:0% +already talked about the phylogenetic +tree of evolution and the gene + + align:start position:0% +tree of evolution and the gene + + + align:start position:0% +tree of evolution and the gene +expression will be a big Topic in in the + + align:start position:0% +expression will be a big Topic in in the + + + align:start position:0% +expression will be a big Topic in in the +RNA and proteomics part of this course + + align:start position:0% +RNA and proteomics part of this course + + + align:start position:0% +RNA and proteomics part of this course +The small molecules we've Illustrated + + align:start position:0% +The small molecules we've Illustrated + + + align:start position:0% +The small molecules we've Illustrated +today almost everything in this course + + align:start position:0% +today almost everything in this course + + + align:start position:0% +today almost everything in this course +seems to be excluded from Gene ontology + + align:start position:0% +seems to be excluded from Gene ontology + + + align:start position:0% +seems to be excluded from Gene ontology +nevertheless + + align:start position:0% +nevertheless + + + align:start position:0% +nevertheless +uh here we go with just one uh slide + + align:start position:0% +uh here we go with just one uh slide + + + align:start position:0% +uh here we go with just one uh slide +talking about the functions we have + + align:start position:0% +talking about the functions we have + + + align:start position:0% +talking about the functions we have +molecular function what the gene product + + align:start position:0% +molecular function what the gene product + + + align:start position:0% +molecular function what the gene product +can do without specifying where or when + + align:start position:0% +can do without specifying where or when + + + align:start position:0% +can do without specifying where or when +a broad example of this with the enzyme + + align:start position:0% +a broad example of this with the enzyme + + + align:start position:0% +a broad example of this with the enzyme +something that catalyzes and then a very + + align:start position:0% +something that catalyzes and then a very + + + align:start position:0% +something that catalyzes and then a very +specific example of an enzyme would be + + align:start position:0% +specific example of an enzyme would be + + + align:start position:0% +specific example of an enzyme would be +adenylate cyclase something that makes + + align:start position:0% +adenylate cyclase something that makes + + + align:start position:0% +adenylate cyclase something that makes +us a cycle in the ribose of adenylate + + align:start position:0% +us a cycle in the ribose of adenylate + + + align:start position:0% +us a cycle in the ribose of adenylate +this so both of these fall under the + + align:start position:0% +this so both of these fall under the + + + align:start position:0% +this so both of these fall under the +molecular function when you're + + align:start position:0% +molecular function when you're + + + align:start position:0% +molecular function when you're +describing a function of a a protein in + + align:start position:0% +describing a function of a a protein in + + + align:start position:0% +describing a function of a a protein in +a describing a genome a biological + + align:start position:0% +a describing a genome a biological + + + align:start position:0% +a describing a genome a biological +process has to have more than one step + + align:start position:0% +process has to have more than one step + + + align:start position:0% +process has to have more than one step +it's one step that's not a process + + align:start position:0% +it's one step that's not a process + + + align:start position:0% +it's one step that's not a process +it has to have a Time component + + align:start position:0% +it has to have a Time component + + + align:start position:0% +it has to have a Time component +typically and there's a transformation + + align:start position:0% +typically and there's a transformation + + + align:start position:0% +typically and there's a transformation +that occurs examples of signal + + align:start position:0% +that occurs examples of signal + + + align:start position:0% +that occurs examples of signal +transduction is a broad biological + + align:start position:0% +transduction is a broad biological + + + align:start position:0% +transduction is a broad biological +process an example of signal + + align:start position:0% +process an example of signal + + + align:start position:0% +process an example of signal +transduction is cyclic amp biosynthesis + + align:start position:0% +transduction is cyclic amp biosynthesis + + + align:start position:0% +transduction is cyclic amp biosynthesis +the cellular component would be somehow + + align:start position:0% +the cellular component would be somehow + + + align:start position:0% +the cellular component would be somehow +reflecting this assembly to organelle + + align:start position:0% +reflecting this assembly to organelle + + + align:start position:0% +reflecting this assembly to organelle +that we were talking about earlier and + + align:start position:0% +that we were talking about earlier and + + + align:start position:0% +that we were talking about earlier and +here an example you'd have a ribosomal + + align:start position:0% +here an example you'd have a ribosomal + + + align:start position:0% +here an example you'd have a ribosomal +protein being part of a of a ribosome + + align:start position:0% +protein being part of a of a ribosome + + + align:start position:0% +protein being part of a of a ribosome +so it gets you some idea of the + + align:start position:0% +so it gets you some idea of the + + + align:start position:0% +so it gets you some idea of the +components some molecular function + + align:start position:0% +components some molecular function + + + align:start position:0% +components some molecular function +biological processing components now as + + align:start position:0% +biological processing components now as + + + align:start position:0% +biological processing components now as +I said this Gene ontology is based on + + align:start position:0% +I said this Gene ontology is based on + + + align:start position:0% +I said this Gene ontology is based on +facts the facts uh + + align:start position:0% +facts the facts uh + + + align:start position:0% +facts the facts uh +that that are included it's not ideally + + align:start position:0% +that that are included it's not ideally + + + align:start position:0% +that that are included it's not ideally +there would be a direct logical + + align:start position:0% +there would be a direct logical + + + align:start position:0% +there would be a direct logical +connection between the facts that are + + align:start position:0% +connection between the facts that are + + + align:start position:0% +connection between the facts that are +summarized in the hierarchical gene + + align:start position:0% +summarized in the hierarchical gene + + + align:start position:0% +summarized in the hierarchical gene +ontology and the raw data that came out + + align:start position:0% +ontology and the raw data that came out + + + align:start position:0% +ontology and the raw data that came out +of some instrument that is not the case + + align:start position:0% +of some instrument that is not the case + + + align:start position:0% +of some instrument that is not the case +this is all from the literature and it's + + align:start position:0% +this is all from the literature and it's + + + align:start position:0% +this is all from the literature and it's +done on a low budget and uh and examples + + align:start position:0% +done on a low budget and uh and examples + + + align:start position:0% +done on a low budget and uh and examples +of how they summarize it is it's + + align:start position:0% +of how they summarize it is it's + + + align:start position:0% +of how they summarize it is it's +inferred from a mutant phenotype this is + + align:start position:0% +inferred from a mutant phenotype this is + + + align:start position:0% +inferred from a mutant phenotype this is +or genetic interactions so these two are + + align:start position:0% +or genetic interactions so these two are + + + align:start position:0% +or genetic interactions so these two are +genetic or physical interaction those + + align:start position:0% +genetic or physical interaction those + + + align:start position:0% +genetic or physical interaction those +you know this passes for biophysics + + align:start position:0% +you know this passes for biophysics + + + align:start position:0% +you know this passes for biophysics +sequence similarity now we're starting + + align:start position:0% +sequence similarity now we're starting + + + align:start position:0% +sequence similarity now we're starting +as we go down this list we're starting + + align:start position:0% +as we go down this list we're starting + + + align:start position:0% +as we go down this list we're starting +to get into murkier and murkier evidence + + align:start position:0% +to get into murkier and murkier evidence + + + align:start position:0% +to get into murkier and murkier evidence +sequence similarity as you'll see in the + + align:start position:0% +sequence similarity as you'll see in the + + + align:start position:0% +sequence similarity as you'll see in the +subsequent slide has problems + + align:start position:0% +subsequent slide has problems + + + align:start position:0% +subsequent slide has problems +direct that a direct assay + + align:start position:0% +direct that a direct assay + + + align:start position:0% +direct that a direct assay +um Can could be a physical interaction + + align:start position:0% +um Can could be a physical interaction + + + align:start position:0% +um Can could be a physical interaction +it could be some other biochemical assay + + align:start position:0% +it could be some other biochemical assay + + + align:start position:0% +it could be some other biochemical assay +expression pattern might be evidence of + + align:start position:0% +expression pattern might be evidence of + + + align:start position:0% +expression pattern might be evidence of +some of the associations that were + + align:start position:0% +some of the associations that were + + + align:start position:0% +some of the associations that were +mentioned in the gene ontology now we + + align:start position:0% +mentioned in the gene ontology now we + + + align:start position:0% +mentioned in the gene ontology now we +get to electronic annotation in a + + align:start position:0% +get to electronic annotation in a + + + align:start position:0% +get to electronic annotation in a +certain sense all these things are + + align:start position:0% +certain sense all these things are + + + align:start position:0% +certain sense all these things are +electronic annotation SQL similarity + + align:start position:0% +electronic annotation SQL similarity + + + align:start position:0% +electronic annotation SQL similarity +might be a way that you automatically + + align:start position:0% +might be a way that you automatically + + + align:start position:0% +might be a way that you automatically +get electronic annotation then you get + + align:start position:0% +get electronic annotation then you get + + + align:start position:0% +get electronic annotation then you get +to a traceable author statement this + + align:start position:0% +to a traceable author statement this + + + align:start position:0% +to a traceable author statement this +means that someone said that something + + align:start position:0% +means that someone said that something + + + align:start position:0% +means that someone said that something +is true without saying how he knows he + + align:start position:0% +is true without saying how he knows he + + + align:start position:0% +is true without saying how he knows he +or she knows it's true so we're getting + + align:start position:0% +or she knows it's true so we're getting + + + align:start position:0% +or she knows it's true so we're getting +really murky and the murkiest of all is + + align:start position:0% +really murky and the murkiest of all is + + + align:start position:0% +really murky and the murkiest of all is +non-praceable authorization you don't + + align:start position:0% +non-praceable authorization you don't + + + align:start position:0% +non-praceable authorization you don't +even know who said the associate might + + align:start position:0% +even know who said the associate might + + + align:start position:0% +even know who said the associate might +be true okay + + align:start position:0% +be true okay + + + align:start position:0% +be true okay +let's go back up to the top of that in + + align:start position:0% +let's go back up to the top of that in + + + align:start position:0% +let's go back up to the top of that in +fact go beyond the top of it where we + + align:start position:0% +fact go beyond the top of it where we + + + align:start position:0% +fact go beyond the top of it where we +now will start tracking the data from + + align:start position:0% +now will start tracking the data from + + + align:start position:0% +now will start tracking the data from +the instruments to uh statements and + + align:start position:0% +the instruments to uh statements and + + + align:start position:0% +the instruments to uh statements and +hopefully in the in this course you will + + align:start position:0% +hopefully in the in this course you will + + + align:start position:0% +hopefully in the in this course you will +um + + align:start position:0% +um + + + align:start position:0% +um +uh see how we will in the future in + + align:start position:0% +uh see how we will in the future in + + + align:start position:0% +uh see how we will in the future in +present be uh make models in a rigorous + + align:start position:0% +present be uh make models in a rigorous + + + align:start position:0% +present be uh make models in a rigorous +way where you can track it all the way + + align:start position:0% +way where you can track it all the way + + + align:start position:0% +way where you can track it all the way +back to data so one class the most + + align:start position:0% +back to data so one class the most + + + align:start position:0% +back to data so one class the most +obvious class of data collection is what + + align:start position:0% +obvious class of data collection is what + + + align:start position:0% +obvious class of data collection is what +I would call Direct observation + + align:start position:0% +I would call Direct observation + + + align:start position:0% +I would call Direct observation +typically through a microscope and + + align:start position:0% +typically through a microscope and + + + align:start position:0% +typically through a microscope and +here's a particularly powerful case I + + align:start position:0% +here's a particularly powerful case I + + + align:start position:0% +here's a particularly powerful case I +promised you earlier that we would you + + align:start position:0% +promised you earlier that we would you + + + align:start position:0% +promised you earlier that we would you +know talk about how you have + + align:start position:0% +know talk about how you have + + + align:start position:0% +know talk about how you have +959 cells in the non-gonal cell lineage + + align:start position:0% +959 cells in the non-gonal cell lineage + + + align:start position:0% +959 cells in the non-gonal cell lineage +of the worm it starts as a single cell + + align:start position:0% +of the worm it starts as a single cell + + + align:start position:0% +of the worm it starts as a single cell +up here at the top middle of fertilized + + align:start position:0% +up here at the top middle of fertilized + + + align:start position:0% +up here at the top middle of fertilized +egg as this egg-shaped thing at the top + + align:start position:0% +egg as this egg-shaped thing at the top + + + align:start position:0% +egg as this egg-shaped thing at the top +and then it splits oh way off to the + + align:start position:0% +and then it splits oh way off to the + + + align:start position:0% +and then it splits oh way off to the +left and off to the right and that makes + + align:start position:0% +left and off to the right and that makes + + + align:start position:0% +left and off to the right and that makes +two Cells Two stem cells that are + + align:start position:0% +two Cells Two stem cells that are + + + align:start position:0% +two Cells Two stem cells that are +capable of differentiating or and + + align:start position:0% +capable of differentiating or and + + + align:start position:0% +capable of differentiating or and +dividing further and they make they each + + align:start position:0% +dividing further and they make they each + + + align:start position:0% +dividing further and they make they each +make two more and it keeps going but you + + align:start position:0% +make two more and it keeps going but you + + + align:start position:0% +make two more and it keeps going but you +can see it start it starts getting uh so + + align:start position:0% +can see it start it starts getting uh so + + + align:start position:0% +can see it start it starts getting uh so +you get symmetry breaking almost + + align:start position:0% +you get symmetry breaking almost + + + align:start position:0% +you get symmetry breaking almost +immediately in fact the egg itself is an + + align:start position:0% +immediately in fact the egg itself is an + + + align:start position:0% +immediately in fact the egg itself is an +asymmetric entity + + align:start position:0% +asymmetric entity + + + align:start position:0% +asymmetric entity +and you start getting lineages that will + + align:start position:0% +and you start getting lineages that will + + + align:start position:0% +and you start getting lineages that will +either die as they terminate or they + + align:start position:0% +either die as they terminate or they + + + align:start position:0% +either die as they terminate or they +will just stop dividing + + align:start position:0% +will just stop dividing + + + align:start position:0% +will just stop dividing +and eventually you end up with + + align:start position:0% +and eventually you end up with + + + align:start position:0% +and eventually you end up with +um after about a thousand cell divisions + + align:start position:0% +um after about a thousand cell divisions + + + align:start position:0% +um after about a thousand cell divisions +or so you end up with these 959 + + align:start position:0% +or so you end up with these 959 + + + align:start position:0% +or so you end up with these 959 +um non-dodial cells + + align:start position:0% +um non-dodial cells + + + align:start position:0% +um non-dodial cells +okay and this is this lineage has been + + align:start position:0% +okay and this is this lineage has been + + + align:start position:0% +okay and this is this lineage has been +completely mapped out by direct + + align:start position:0% +completely mapped out by direct + + + align:start position:0% +completely mapped out by direct +microscopic observation where a series + + align:start position:0% +microscopic observation where a series + + + align:start position:0% +microscopic observation where a series +of photographs you can show that this + + align:start position:0% +of photographs you can show that this + + + align:start position:0% +of photographs you can show that this +single cell turns into these two cells + + align:start position:0% +single cell turns into these two cells + + + align:start position:0% +single cell turns into these two cells +so you have a time axis and you have a + + align:start position:0% +so you have a time axis and you have a + + + align:start position:0% +so you have a time axis and you have a +lineage axis which is one of these + + align:start position:0% +lineage axis which is one of these + + + align:start position:0% +lineage axis which is one of these +directed acyclic graphs + + align:start position:0% +directed acyclic graphs + + + align:start position:0% +directed acyclic graphs +okay in addition and even more amazing + + align:start position:0% +okay in addition and even more amazing + + + align:start position:0% +okay in addition and even more amazing +to me anyway is that you have a complete + + align:start position:0% +to me anyway is that you have a complete + + + align:start position:0% +to me anyway is that you have a complete +neural connection for this multicellular + + align:start position:0% +neural connection for this multicellular + + + align:start position:0% +neural connection for this multicellular +organism it has a fairly simple brain uh + + align:start position:0% +organism it has a fairly simple brain uh + + + align:start position:0% +organism it has a fairly simple brain uh +if you've ever had a conversation with + + align:start position:0% +if you've ever had a conversation with + + + align:start position:0% +if you've ever had a conversation with +one of these things but uh it still has + + align:start position:0% +one of these things but uh it still has + + + align:start position:0% +one of these things but uh it still has +uh + + align:start position:0% +uh + + + align:start position:0% +uh +each neuron has can have + + align:start position:0% +each neuron has can have + + + align:start position:0% +each neuron has can have +dozens to hundreds of connections + + align:start position:0% +dozens to hundreds of connections + + + align:start position:0% +dozens to hundreds of connections +and these have been mapped by a Serial + + align:start position:0% +and these have been mapped by a Serial + + + align:start position:0% +and these have been mapped by a Serial +section through the entire worm very + + align:start position:0% +section through the entire worm very + + + align:start position:0% +section through the entire worm very +thin sections and electron microscopy + + align:start position:0% +thin sections and electron microscopy + + + align:start position:0% +thin sections and electron microscopy +and then checking out the whole wiring + + align:start position:0% +and then checking out the whole wiring + + + align:start position:0% +and then checking out the whole wiring +diagram this is a really a tour de force + + align:start position:0% +diagram this is a really a tour de force + + + align:start position:0% +diagram this is a really a tour de force +and part of the reason it's possible + + align:start position:0% +and part of the reason it's possible + + + align:start position:0% +and part of the reason it's possible +this would even be hard to do in variety + + align:start position:0% +this would even be hard to do in variety + + + align:start position:0% +this would even be hard to do in variety +organisms but this is another case where + + align:start position:0% +organisms but this is another case where + + + align:start position:0% +organisms but this is another case where +biology cooperates just like with the + + align:start position:0% +biology cooperates just like with the + + + align:start position:0% +biology cooperates just like with the +genetic code in this particular organism + + align:start position:0% +genetic code in this particular organism + + + align:start position:0% +genetic code in this particular organism +that lineage happens the same way every + + align:start position:0% +that lineage happens the same way every + + + align:start position:0% +that lineage happens the same way every +time + + align:start position:0% +time + + + align:start position:0% +time +in in even slightly more complicated + + align:start position:0% +in in even slightly more complicated + + + align:start position:0% +in in even slightly more complicated +organisms like the drosophila fruit fly + + align:start position:0% +organisms like the drosophila fruit fly + + + align:start position:0% +organisms like the drosophila fruit fly +or humans uh the the lineages are not so + + align:start position:0% +or humans uh the the lineages are not so + + + align:start position:0% +or humans uh the the lineages are not so +strict and a cell that can take on a + + align:start position:0% +strict and a cell that can take on a + + + align:start position:0% +strict and a cell that can take on a +number of different directions depending + + align:start position:0% +number of different directions depending + + + align:start position:0% +number of different directions depending +on the exact physical environment it + + align:start position:0% +on the exact physical environment it + + + align:start position:0% +on the exact physical environment it +finds itself in but nevertheless for + + align:start position:0% +finds itself in but nevertheless for + + + align:start position:0% +finds itself in but nevertheless for +this one the neural connections are + + align:start position:0% +this one the neural connections are + + + align:start position:0% +this one the neural connections are +reproducible and the cell lineage is + + align:start position:0% +reproducible and the cell lineage is + + + align:start position:0% +reproducible and the cell lineage is +reproducible and so you can map this all + + align:start position:0% +reproducible and so you can map this all + + + align:start position:0% +reproducible and so you can map this all +out + + align:start position:0% +out + + + align:start position:0% +out +for other organisms it doesn't mean you + + align:start position:0% +for other organisms it doesn't mean you + + + align:start position:0% +for other organisms it doesn't mean you +shouldn't try it it just means you'll + + align:start position:0% +shouldn't try it it just means you'll + + + align:start position:0% +shouldn't try it it just means you'll +have to represent it in a slightly less + + align:start position:0% +have to represent it in a slightly less + + + align:start position:0% +have to represent it in a slightly less +uh fixed pattern you'll have to + + align:start position:0% +uh fixed pattern you'll have to + + + align:start position:0% +uh fixed pattern you'll have to +represent it a probabilistic set of + + align:start position:0% +represent it a probabilistic set of + + + align:start position:0% +represent it a probabilistic set of +Divisions and probabilistic set of + + align:start position:0% +Divisions and probabilistic set of + + + align:start position:0% +Divisions and probabilistic set of +neural connections and they've even + + align:start position:0% +neural connections and they've even + + + align:start position:0% +neural connections and they've even +conditional upon what on various + + align:start position:0% +conditional upon what on various + + + align:start position:0% +conditional upon what on various +conditions okay that's direct + + align:start position:0% +conditions okay that's direct + + + align:start position:0% +conditions okay that's direct +observation is a class of source of data + + align:start position:0% +observation is a class of source of data + + + align:start position:0% +observation is a class of source of data +for for modeling + + align:start position:0% +for for modeling + + + align:start position:0% +for for modeling +here's three other sources of data in + + align:start position:0% +here's three other sources of data in + + + align:start position:0% +here's three other sources of data in +each case I've shown pretty raw + + align:start position:0% +each case I've shown pretty raw + + + align:start position:0% +each case I've shown pretty raw +representations of the data you can + + align:start position:0% +representations of the data you can + + + align:start position:0% +representations of the data you can +think of these all as representing an + + align:start position:0% +think of these all as representing an + + + align:start position:0% +think of these all as representing an +intensity readout + + align:start position:0% +intensity readout + + + align:start position:0% +intensity readout +with some sort of Separation as the + + align:start position:0% +with some sort of Separation as the + + + align:start position:0% +with some sort of Separation as the +uh as the as the horizontal axis or in + + align:start position:0% +uh as the as the horizontal axis or in + + + align:start position:0% +uh as the as the horizontal axis or in +some case both axes so the intensity + + align:start position:0% +some case both axes so the intensity + + + align:start position:0% +some case both axes so the intensity +here is indicated by a a fine plot of + + align:start position:0% +here is indicated by a a fine plot of + + + align:start position:0% +here is indicated by a a fine plot of +four different color fluorophores in an + + align:start position:0% +four different color fluorophores in an + + + align:start position:0% +four different color fluorophores in an +electrophoretic separation + + align:start position:0% +electrophoretic separation + + + align:start position:0% +electrophoretic separation +um which is the basis for the genomic + + align:start position:0% +um which is the basis for the genomic + + + align:start position:0% +um which is the basis for the genomic +sequencing that we're that we're so uh + + align:start position:0% +sequencing that we're that we're so uh + + + align:start position:0% +sequencing that we're that we're so uh +proud of here + + align:start position:0% +proud of here + + + align:start position:0% +proud of here +um then for uh so here the detection is + + align:start position:0% +um then for uh so here the detection is + + + align:start position:0% +um then for uh so here the detection is +fluorescence + + align:start position:0% +fluorescence + + + align:start position:0% +fluorescence +of the of the terminated uh chains of + + align:start position:0% +of the of the terminated uh chains of + + + align:start position:0% +of the of the terminated uh chains of +DNA we'll get to that later in the + + align:start position:0% +DNA we'll get to that later in the + + + align:start position:0% +DNA we'll get to that later in the +course here you have mass spectrometry + + align:start position:0% +course here you have mass spectrometry + + + align:start position:0% +course here you have mass spectrometry +where you're measuring differences in + + align:start position:0% +where you're measuring differences in + + + align:start position:0% +where you're measuring differences in +masses even more accurately than in in + + align:start position:0% +masses even more accurately than in in + + + align:start position:0% +masses even more accurately than in in +sequencing you're separating nucleic + + align:start position:0% +sequencing you're separating nucleic + + + align:start position:0% +sequencing you're separating nucleic +acids by the differences in Mass to + + align:start position:0% +acids by the differences in Mass to + + + align:start position:0% +acids by the differences in Mass to +about one part in a thousand the mass + + align:start position:0% +about one part in a thousand the mass + + + align:start position:0% +about one part in a thousand the mass +spectrometry is more like one part in + + align:start position:0% +spectrometry is more like one part in + + + align:start position:0% +spectrometry is more like one part in +ten thousand or even better + + align:start position:0% +ten thousand or even better + + + align:start position:0% +ten thousand or even better +um because here we're separating in a + + align:start position:0% +um because here we're separating in a + + + align:start position:0% +um because here we're separating in a +gas phase based on the electrical and + + align:start position:0% +gas phase based on the electrical and + + + align:start position:0% +gas phase based on the electrical and +magnetic properties here you're + + align:start position:0% +magnetic properties here you're + + + align:start position:0% +magnetic properties here you're +separating by charge in a liquid phase + + align:start position:0% +separating by charge in a liquid phase + + + align:start position:0% +separating by charge in a liquid phase +and liquid and gel phase + + align:start position:0% +and liquid and gel phase + + + align:start position:0% +and liquid and gel phase +each of these you can you can specify + + align:start position:0% +each of these you can you can specify + + + align:start position:0% +each of these you can you can specify +the the throughput per day or your + + align:start position:0% +the the throughput per day or your + + + align:start position:0% +the the throughput per day or your +throughput for per unit dollar this is + + align:start position:0% +throughput for per unit dollar this is + + + align:start position:0% +throughput for per unit dollar this is +this becomes important in planning these + + align:start position:0% +this becomes important in planning these + + + align:start position:0% +this becomes important in planning these +these structures the third uh category + + align:start position:0% +these structures the third uh category + + + align:start position:0% +these structures the third uh category +here is arrays these can be arrays of of + + align:start position:0% +here is arrays these can be arrays of of + + + align:start position:0% +here is arrays these can be arrays of of +nucleic acids for quantitating rnas or + + align:start position:0% +nucleic acids for quantitating rnas or + + + align:start position:0% +nucleic acids for quantitating rnas or +arrays of antibodies proteins small + + align:start position:0% +arrays of antibodies proteins small + + + align:start position:0% +arrays of antibodies proteins small +molecule chemicals which we can + + align:start position:0% +molecule chemicals which we can + + + align:start position:0% +molecule chemicals which we can +quantitate The Binding of one kind of + + align:start position:0% +quantitate The Binding of one kind of + + + align:start position:0% +quantitate The Binding of one kind of +molecule to an array of other molecules + + align:start position:0% +molecule to an array of other molecules + + + align:start position:0% +molecule to an array of other molecules +in each in both the top and the bottom + + align:start position:0% +in each in both the top and the bottom + + + align:start position:0% +in each in both the top and the bottom +you can have multiple colors and these + + align:start position:0% +you can have multiple colors and these + + + align:start position:0% +you can have multiple colors and these +can be used + + align:start position:0% +can be used + + + align:start position:0% +can be used +quantitatively as internal standards so + + align:start position:0% +quantitatively as internal standards so + + + align:start position:0% +quantitatively as internal standards so +that you can monitor this process so + + align:start position:0% +that you can monitor this process so + + + align:start position:0% +that you can monitor this process so +we're going to go into this in great + + align:start position:0% +we're going to go into this in great + + + align:start position:0% +we're going to go into this in great +detail later on but I want to give you a + + align:start position:0% +detail later on but I want to give you a + + + align:start position:0% +detail later on but I want to give you a +feeling for where the source of these + + align:start position:0% +feeling for where the source of these + + + align:start position:0% +feeling for where the source of these +things are this array analysis in a + + align:start position:0% +things are this array analysis in a + + + align:start position:0% +things are this array analysis in a +sense is another example of microscopy + + align:start position:0% +sense is another example of microscopy + + + align:start position:0% +sense is another example of microscopy +just like in the previous slide we used + + align:start position:0% +just like in the previous slide we used + + + align:start position:0% +just like in the previous slide we used +direct observation microscopy to to + + align:start position:0% +direct observation microscopy to to + + + align:start position:0% +direct observation microscopy to to +monitor cell lineages so too we can do + + align:start position:0% +monitor cell lineages so too we can do + + + align:start position:0% +monitor cell lineages so too we can do +it we can make a + + align:start position:0% + + + + align:start position:0% + +it's just you know it's just wonderful + + align:start position:0% +it's just you know it's just wonderful + + + align:start position:0% +it's just you know it's just wonderful +the battery is charged okay + + align:start position:0% + + + + align:start position:0% + +we can take the + + align:start position:0% +we can take the + + + align:start position:0% +we can take the +microscopy of artificial patterns such + + align:start position:0% +microscopy of artificial patterns such + + + align:start position:0% +microscopy of artificial patterns such +as arrays + + align:start position:0% +as arrays + + + align:start position:0% +as arrays +just as we have separation here by mass + + align:start position:0% +just as we have separation here by mass + + + align:start position:0% +just as we have separation here by mass +we can also have separation on a variety + + align:start position:0% +we can also have separation on a variety + + + align:start position:0% +we can also have separation on a variety +of other properties sometimes called + + align:start position:0% +of other properties sometimes called + + + align:start position:0% +of other properties sometimes called +multi-dimensional separation this gets + + align:start position:0% +multi-dimensional separation this gets + + + align:start position:0% +multi-dimensional separation this gets +back to the first slide of the of the + + align:start position:0% +back to the first slide of the of the + + + align:start position:0% +back to the first slide of the of the +lecture which is uh which was the + + align:start position:0% +lecture which is uh which was the + + + align:start position:0% +lecture which is uh which was the +purification aspect + + align:start position:0% +purification aspect + + + align:start position:0% +purification aspect +now how do we jump from that kind of raw + + align:start position:0% +now how do we jump from that kind of raw + + + align:start position:0% +now how do we jump from that kind of raw +data + + align:start position:0% +data + + + align:start position:0% +data +to these uh common way that biologists + + align:start position:0% +to these uh common way that biologists + + + align:start position:0% +to these uh common way that biologists +communicate in journals where you have + + align:start position:0% +communicate in journals where you have + + + align:start position:0% +communicate in journals where you have +circles and arrows where circles might + + align:start position:0% +circles and arrows where circles might + + + align:start position:0% +circles and arrows where circles might +be some kind of protein molecule such as + + align:start position:0% +be some kind of protein molecule such as + + + align:start position:0% +be some kind of protein molecule such as +a stat + + align:start position:0% +a stat + + + align:start position:0% +a stat +and arrow indicates some sort of + + align:start position:0% +and arrow indicates some sort of + + + align:start position:0% +and arrow indicates some sort of +interaction or regulation or + + align:start position:0% +interaction or regulation or + + + align:start position:0% +interaction or regulation or +quantitative + + align:start position:0% +quantitative + + + align:start position:0% +quantitative +influence that one protein has on + + align:start position:0% +influence that one protein has on + + + align:start position:0% +influence that one protein has on +another or a protein or so the note in + + align:start position:0% +another or a protein or so the note in + + + align:start position:0% +another or a protein or so the note in +alternative diagrams the nodes could be + + align:start position:0% +alternative diagrams the nodes could be + + + align:start position:0% +alternative diagrams the nodes could be +small molecules and the the edges the + + align:start position:0% +small molecules and the the edges the + + + align:start position:0% +small molecules and the the edges the +links between the nodes could be a + + align:start position:0% +links between the nodes could be a + + + align:start position:0% +links between the nodes could be a +enzymatic reaction catalyzed by a + + align:start position:0% +enzymatic reaction catalyzed by a + + + align:start position:0% +enzymatic reaction catalyzed by a +protein they're about 500 biological + + align:start position:0% +protein they're about 500 biological + + + align:start position:0% +protein they're about 500 biological +databases that we'll talk about in the + + align:start position:0% +databases that we'll talk about in the + + + align:start position:0% +databases that we'll talk about in the +database talk + + align:start position:0% +database talk + + + align:start position:0% +database talk +um + + align:start position:0% +um + + + align:start position:0% +um +how the data and models were entered in + + align:start position:0% +how the data and models were entered in + + + align:start position:0% +how the data and models were entered in +these databases is a is a huge issue + + align:start position:0% +these databases is a is a huge issue + + + align:start position:0% +these databases is a is a huge issue +many of them have been done very + + align:start position:0% +many of them have been done very + + + align:start position:0% +many of them have been done very +casually for + + align:start position:0% +casually for + + + align:start position:0% +casually for +DNA sequencing and crystallography I + + align:start position:0% +DNA sequencing and crystallography I + + + align:start position:0% +DNA sequencing and crystallography I +think the process by which you go from + + align:start position:0% +think the process by which you go from + + + align:start position:0% +think the process by which you go from +the raw data to the models is very well + + align:start position:0% +the raw data to the models is very well + + + align:start position:0% +the raw data to the models is very well +understood very well communicated for + + align:start position:0% +understood very well communicated for + + + align:start position:0% +understood very well communicated for +this sort of thing it take it will take + + align:start position:0% +this sort of thing it take it will take + + + align:start position:0% +this sort of thing it take it will take +this whole course for us to even to + + align:start position:0% +this whole course for us to even to + + + align:start position:0% +this whole course for us to even to +scratch the surface here's another + + align:start position:0% +scratch the surface here's another + + + align:start position:0% +scratch the surface here's another +example that one was protein protein + + align:start position:0% +example that one was protein protein + + + align:start position:0% +example that one was protein protein +interactions this is an example where + + align:start position:0% +interactions this is an example where + + + align:start position:0% +interactions this is an example where +the the nodes now are not proteins but + + align:start position:0% +the the nodes now are not proteins but + + + align:start position:0% +the the nodes now are not proteins but +small molecules and they're connected by + + align:start position:0% +small molecules and they're connected by + + + align:start position:0% +small molecules and they're connected by +an enzymatic pathway this is another + + align:start position:0% +an enzymatic pathway this is another + + + align:start position:0% +an enzymatic pathway this is another +example of an application of ordinary + + align:start position:0% +example of an application of ordinary + + + align:start position:0% +example of an application of ordinary +difference equations just like the one + + align:start position:0% +difference equations just like the one + + + align:start position:0% +difference equations just like the one +in last class we've had exponential + + align:start position:0% +in last class we've had exponential + + + align:start position:0% +in last class we've had exponential +growth here you have simple fluxes where + + align:start position:0% +growth here you have simple fluxes where + + + align:start position:0% +growth here you have simple fluxes where +a catalytic reaction occurs not Auto + + align:start position:0% +a catalytic reaction occurs not Auto + + + align:start position:0% +a catalytic reaction occurs not Auto +catalytic but catalytic there's no + + align:start position:0% +catalytic but catalytic there's no + + + align:start position:0% +catalytic but catalytic there's no +there's no exponential growth occurring + + align:start position:0% +there's no exponential growth occurring + + + align:start position:0% +there's no exponential growth occurring +in this + + align:start position:0% +in this + + + align:start position:0% +in this +cell it doesn't have any biopolymers in + + align:start position:0% +cell it doesn't have any biopolymers in + + + align:start position:0% +cell it doesn't have any biopolymers in +it five polymer synthesis + + align:start position:0% +it five polymer synthesis + + + align:start position:0% +it five polymer synthesis +um but this but these catalytic + + align:start position:0% +um but this but these catalytic + + + align:start position:0% +um but this but these catalytic +reactions that form this network and you + + align:start position:0% +reactions that form this network and you + + + align:start position:0% +reactions that form this network and you +can model the influx of of fresh + + align:start position:0% +can model the influx of of fresh + + + align:start position:0% +can model the influx of of fresh +molecules and its utilization within the + + align:start position:0% +molecules and its utilization within the + + + align:start position:0% +molecules and its utilization within the +cell and the E flux + + align:start position:0% +cell and the E flux + + + align:start position:0% +cell and the E flux +we'll come back to that inside there are + + align:start position:0% +we'll come back to that inside there are + + + align:start position:0% +we'll come back to that inside there are +a set of kinetic equations we need to + + align:start position:0% +a set of kinetic equations we need to + + + align:start position:0% +a set of kinetic equations we need to +figure out how to get from the raw data + + align:start position:0% +figure out how to get from the raw data + + + align:start position:0% +figure out how to get from the raw data +types that I've shown you to this kind + + align:start position:0% +types that I've shown you to this kind + + + align:start position:0% +types that I've shown you to this kind +of equation this will be one of the + + align:start position:0% +of equation this will be one of the + + + align:start position:0% +of equation this will be one of the +goals of the course here you have a + + align:start position:0% +goals of the course here you have a + + + align:start position:0% +goals of the course here you have a +velocity on the far left hand side of + + align:start position:0% +velocity on the far left hand side of + + + align:start position:0% +velocity on the far left hand side of +the top equation which is related to a + + align:start position:0% +the top equation which is related to a + + + align:start position:0% +the top equation which is related to a +maximal velocity on the on the numerator + + align:start position:0% +maximal velocity on the on the numerator + + + align:start position:0% +maximal velocity on the on the numerator +and then a series of linear uh sums and + + align:start position:0% +and then a series of linear uh sums and + + + align:start position:0% +and then a series of linear uh sums and +quotients + + align:start position:0% +quotients + + + align:start position:0% +quotients +now some of the terms will be non-linear + + align:start position:0% +now some of the terms will be non-linear + + + align:start position:0% +now some of the terms will be non-linear +uh here's an exponent of 4 that enters + + align:start position:0% +uh here's an exponent of 4 that enters + + + align:start position:0% +uh here's an exponent of 4 that enters +in because you have one of these + + align:start position:0% +in because you have one of these + + + align:start position:0% +in because you have one of these +cooperativities that gives you that kind + + align:start position:0% +cooperativities that gives you that kind + + + align:start position:0% +cooperativities that gives you that kind +of sigmoidal curve that we showed for + + align:start position:0% +of sigmoidal curve that we showed for + + + align:start position:0% +of sigmoidal curve that we showed for +transistors and we'll enter to a number + + align:start position:0% +transistors and we'll enter to a number + + + align:start position:0% +transistors and we'll enter to a number +of biological consequences where that + + align:start position:0% +of biological consequences where that + + + align:start position:0% +of biological consequences where that +the steepness of that sigmoral curve is + + align:start position:0% +the steepness of that sigmoral curve is + + + align:start position:0% +the steepness of that sigmoral curve is +determined by this exponent sometimes + + align:start position:0% +determined by this exponent sometimes + + + align:start position:0% +determined by this exponent sometimes +called a hill coefficient + + align:start position:0% +called a hill coefficient + + + align:start position:0% +called a hill coefficient +but other than that you'll get uh you'll + + align:start position:0% +but other than that you'll get uh you'll + + + align:start position:0% +but other than that you'll get uh you'll +get these simple linear sums and + + align:start position:0% +get these simple linear sums and + + + align:start position:0% +get these simple linear sums and +quotients and we'll come back to that + + align:start position:0% +quotients and we'll come back to that + + + align:start position:0% +quotients and we'll come back to that +what actually constitutes these Networks + + align:start position:0% +what actually constitutes these Networks + + + align:start position:0% +what actually constitutes these Networks +I want you to feel + + align:start position:0% +I want you to feel + + + align:start position:0% +I want you to feel +less limited than than you might get in + + align:start position:0% +less limited than than you might get in + + + align:start position:0% +less limited than than you might get in +a simple textbook so a simple textbook + + align:start position:0% +a simple textbook so a simple textbook + + + align:start position:0% +a simple textbook so a simple textbook +definition of a catalytic enzyme + + align:start position:0% +definition of a catalytic enzyme + + + align:start position:0% +definition of a catalytic enzyme +catalyzed process you might have a is a + + align:start position:0% +catalyzed process you might have a is a + + + align:start position:0% +catalyzed process you might have a is a +sub is a substrate that turns into b as + + align:start position:0% +sub is a substrate that turns into b as + + + align:start position:0% +sub is a substrate that turns into b as +a product this is a process to a could + + align:start position:0% +a product this is a process to a could + + + align:start position:0% +a product this is a process to a could +go to B spontaneously but in the + + align:start position:0% +go to B spontaneously but in the + + + align:start position:0% +go to B spontaneously but in the +presence of enzyme it goes faster or it + + align:start position:0% +presence of enzyme it goes faster or it + + + align:start position:0% +presence of enzyme it goes faster or it +could be that for all intents and + + align:start position:0% +could be that for all intents and + + + align:start position:0% +could be that for all intents and +purposes a never turns into B it's so + + align:start position:0% +purposes a never turns into B it's so + + + align:start position:0% +purposes a never turns into B it's so +slow that you need this enzyme here to + + align:start position:0% +slow that you need this enzyme here to + + + align:start position:0% +slow that you need this enzyme here to +even detect it enzyme will form a + + align:start position:0% +even detect it enzyme will form a + + + align:start position:0% +even detect it enzyme will form a +complex with a this could be a + + align:start position:0% +complex with a this could be a + + + align:start position:0% +complex with a this could be a +non-covalent complex or a covalent one + + align:start position:0% +non-covalent complex or a covalent one + + + align:start position:0% +non-covalent complex or a covalent one +it then produces a covalent change in a + + align:start position:0% +it then produces a covalent change in a + + + align:start position:0% +it then produces a covalent change in a +and it becomes about an enzyme bound b b + + align:start position:0% +and it becomes about an enzyme bound b b + + + align:start position:0% +and it becomes about an enzyme bound b b +is released enzyme e is regenerated and + + align:start position:0% +is released enzyme e is regenerated and + + + align:start position:0% +is released enzyme e is regenerated and +so in a certain sense in this process of + + align:start position:0% +so in a certain sense in this process of + + + align:start position:0% +so in a certain sense in this process of +turning a to b e is not consumed + + align:start position:0% +turning a to b e is not consumed + + + align:start position:0% +turning a to b e is not consumed +but let's think about + + align:start position:0% +but let's think about + + + align:start position:0% +but let's think about +an increasingly important class of + + align:start position:0% +an increasingly important class of + + + align:start position:0% +an increasingly important class of +biochemistry such as signal transduction + + align:start position:0% +biochemistry such as signal transduction + + + align:start position:0% +biochemistry such as signal transduction +where the enzyme now has a new role it + + align:start position:0% +where the enzyme now has a new role it + + + align:start position:0% +where the enzyme now has a new role it +has its changes places with a substrate + + align:start position:0% +has its changes places with a substrate + + + align:start position:0% +has its changes places with a substrate +it becomes a substrate the E now is a + + align:start position:0% +it becomes a substrate the E now is a + + + align:start position:0% +it becomes a substrate the E now is a +substrate in which a small molecule ATP + + align:start position:0% +substrate in which a small molecule ATP + + + align:start position:0% +substrate in which a small molecule ATP +which might have been the a of here + + align:start position:0% + + + + align:start position:0% + +combines with the E and the E could + + align:start position:0% +combines with the E and the E could + + + align:start position:0% +combines with the E and the E could +either uh catalyze his own + + align:start position:0% +either uh catalyze his own + + + align:start position:0% +either uh catalyze his own +phosphorylation or in context with + + align:start position:0% +phosphorylation or in context with + + + align:start position:0% +phosphorylation or in context with +another enzyme but in any case it + + align:start position:0% +another enzyme but in any case it + + + align:start position:0% +another enzyme but in any case it +becomes covalently modified to produce a + + align:start position:0% +becomes covalently modified to produce a + + + align:start position:0% +becomes covalently modified to produce a +phosphorylated enzyme a phospholated + + align:start position:0% +phosphorylated enzyme a phospholated + + + align:start position:0% +phosphorylated enzyme a phospholated +protein and then the ATP is regenerated + + align:start position:0% +protein and then the ATP is regenerated + + + align:start position:0% +protein and then the ATP is regenerated +by a simple enzymatic process and so in + + align:start position:0% +by a simple enzymatic process and so in + + + align:start position:0% +by a simple enzymatic process and so in +a certain sense formally it's very + + align:start position:0% +a certain sense formally it's very + + + align:start position:0% +a certain sense formally it's very +similar to this process except you now + + align:start position:0% +similar to this process except you now + + + align:start position:0% +similar to this process except you now +flip the enzyme of the substrate ATP is + + align:start position:0% +flip the enzyme of the substrate ATP is + + + align:start position:0% +flip the enzyme of the substrate ATP is +not consumed or you know the small + + align:start position:0% +not consumed or you know the small + + + align:start position:0% +not consumed or you know the small +molecule is not consumed the enzyme is + + align:start position:0% +molecule is not consumed the enzyme is + + + align:start position:0% +molecule is not consumed the enzyme is +consumed so think of these things these + + align:start position:0% +consumed so think of these things these + + + align:start position:0% +consumed so think of these things these +networks as symmetrically as you can try + + align:start position:0% +networks as symmetrically as you can try + + + align:start position:0% +networks as symmetrically as you can try +not to to get too embedded in the the + + align:start position:0% +not to to get too embedded in the the + + + align:start position:0% +not to to get too embedded in the the +names uh you know this is enzyme is a + + align:start position:0% +names uh you know this is enzyme is a + + + align:start position:0% +names uh you know this is enzyme is a +substrate and think more about the + + align:start position:0% +substrate and think more about the + + + align:start position:0% +substrate and think more about the +concepts the concept here is some things + + align:start position:0% +concepts the concept here is some things + + + align:start position:0% +concepts the concept here is some things +are consumed and some things uh are + + align:start position:0% +are consumed and some things uh are + + + align:start position:0% +are consumed and some things uh are +catalytic and regenerated + + align:start position:0% +catalytic and regenerated + + + align:start position:0% +catalytic and regenerated +so again we're going to integrate this + + align:start position:0% +so again we're going to integrate this + + + align:start position:0% +so again we're going to integrate this +metabolic processes we're talking about + + align:start position:0% +metabolic processes we're talking about + + + align:start position:0% +metabolic processes we're talking about +in the last couple of slides with the + + align:start position:0% +in the last couple of slides with the + + + align:start position:0% +in the last couple of slides with the +information uh flow which was the the + + align:start position:0% +information uh flow which was the the + + + align:start position:0% +information uh flow which was the the +topic of central dogma + + align:start position:0% +topic of central dogma + + + align:start position:0% +topic of central dogma +in order to get uh functional genomics + + align:start position:0% +in order to get uh functional genomics + + + align:start position:0% +in order to get uh functional genomics +which measures those information + + align:start position:0% +which measures those information + + + align:start position:0% +which measures those information +molecules mostly and produces + + align:start position:0% +molecules mostly and produces + + + align:start position:0% +molecules mostly and produces +quantitative modeling you need to have + + align:start position:0% +quantitative modeling you need to have + + + align:start position:0% +quantitative modeling you need to have +the qualitative models to know what's + + align:start position:0% +the qualitative models to know what's + + + align:start position:0% +the qualitative models to know what's +connected to what you need to have the + + align:start position:0% +connected to what you need to have the + + + align:start position:0% +connected to what you need to have the +raw data as Illustrated in slide 41 + + align:start position:0% +raw data as Illustrated in slide 41 + + + align:start position:0% +raw data as Illustrated in slide 41 +again to remind you the source of + + align:start position:0% +again to remind you the source of + + + align:start position:0% +again to remind you the source of +quantitative data here you can measure + + align:start position:0% +quantitative data here you can measure + + + align:start position:0% +quantitative data here you can measure +RNA or proteins or peptides in the mass + + align:start position:0% +RNA or proteins or peptides in the mass + + + align:start position:0% +RNA or proteins or peptides in the mass +spectrometry RNA and the arrays + + align:start position:0% +spectrometry RNA and the arrays + + + align:start position:0% +spectrometry RNA and the arrays +connected to the DNA provided by the DNA + + align:start position:0% +connected to the DNA provided by the DNA + + + align:start position:0% +connected to the DNA provided by the DNA +sequencing + + align:start position:0% +sequencing + + + align:start position:0% +sequencing +I warned you that uh that one of the + + align:start position:0% +I warned you that uh that one of the + + + align:start position:0% +I warned you that uh that one of the +gene ontology data type sources of data + + align:start position:0% +gene ontology data type sources of data + + + align:start position:0% +gene ontology data type sources of data +was sequenced and electronic sequence + + align:start position:0% +was sequenced and electronic sequence + + + align:start position:0% +was sequenced and electronic sequence +annotation by sequence similarity I want + + align:start position:0% +annotation by sequence similarity I want + + + align:start position:0% +annotation by sequence similarity I want +to elaborate on this warning uh with + + align:start position:0% +to elaborate on this warning uh with + + + align:start position:0% +to elaborate on this warning uh with +this slide where we say + + align:start position:0% +this slide where we say + + + align:start position:0% +this slide where we say +we we have various justifications for + + align:start position:0% +we we have various justifications for + + + align:start position:0% +we we have various justifications for +looking for distant homologs examples of + + align:start position:0% +looking for distant homologs examples of + + + align:start position:0% +looking for distant homologs examples of +Gene products which are related uh by on + + align:start position:0% +Gene products which are related uh by on + + + align:start position:0% +Gene products which are related uh by on +that ultimate pedigree Tree of Life by + + align:start position:0% +that ultimate pedigree Tree of Life by + + + align:start position:0% +that ultimate pedigree Tree of Life by +very long distances it's been a long + + align:start position:0% +very long distances it's been a long + + + align:start position:0% +very long distances it's been a long +time since those things were present as + + align:start position:0% +time since those things were present as + + + align:start position:0% +time since those things were present as +a common ancestor and we want to find + + align:start position:0% +a common ancestor and we want to find + + + align:start position:0% +a common ancestor and we want to find +those because they help us limit the + + align:start position:0% +those because they help us limit the + + + align:start position:0% +those because they help us limit the +number of hypotheses that we need to + + align:start position:0% +number of hypotheses that we need to + + + align:start position:0% +number of hypotheses that we need to +test whenever we find a new molecule if + + align:start position:0% +test whenever we find a new molecule if + + + align:start position:0% +test whenever we find a new molecule if +we can connect it to another molecule + + align:start position:0% +we can connect it to another molecule + + + align:start position:0% +we can connect it to another molecule +however distant then we don't have to we + + align:start position:0% +however distant then we don't have to we + + + align:start position:0% +however distant then we don't have to we +feel we don't have to test every + + align:start position:0% +feel we don't have to test every + + + align:start position:0% +feel we don't have to test every +possible hypothesis we just have to test + + align:start position:0% +possible hypothesis we just have to test + + + align:start position:0% +possible hypothesis we just have to test +that little narrow one but what happens + + align:start position:0% +that little narrow one but what happens + + + align:start position:0% +that little narrow one but what happens +when we do that in the let's say instead + + align:start position:0% +when we do that in the let's say instead + + + align:start position:0% +when we do that in the let's say instead +of some distance homology where we have + + align:start position:0% +of some distance homology where we have + + + align:start position:0% +of some distance homology where we have +say 20 amino acid identity you line up + + align:start position:0% +say 20 amino acid identity you line up + + + align:start position:0% +say 20 amino acid identity you line up +the sequences by methods that we'll talk + + align:start position:0% +the sequences by methods that we'll talk + + + align:start position:0% +the sequences by methods that we'll talk +about later and you have uh 20 of the + + align:start position:0% +about later and you have uh 20 of the + + + align:start position:0% +about later and you have uh 20 of the +positions they're the same or even less + + align:start position:0% +positions they're the same or even less + + + align:start position:0% +positions they're the same or even less +can sometimes be meaningful + + align:start position:0% +can sometimes be meaningful + + + align:start position:0% +can sometimes be meaningful +but how good is that there's going to be + + align:start position:0% +but how good is that there's going to be + + + align:start position:0% +but how good is that there's going to be +some kind of curve that relates + + align:start position:0% +some kind of curve that relates + + + align:start position:0% +some kind of curve that relates +how close two proteins are with the + + align:start position:0% +how close two proteins are with the + + + align:start position:0% +how close two proteins are with the +probability they will have the same + + align:start position:0% +probability they will have the same + + + align:start position:0% +probability they will have the same +biochemical or cell biological or + + align:start position:0% +biochemical or cell biological or + + + align:start position:0% +biochemical or cell biological or +genetic function + + align:start position:0% +genetic function + + + align:start position:0% +genetic function +and here's some worst case scenarios and + + align:start position:0% +and here's some worst case scenarios and + + + align:start position:0% +and here's some worst case scenarios and +I don't mean to represent these as + + align:start position:0% +I don't mean to represent these as + + + align:start position:0% +I don't mean to represent these as +typical but but to get you doubting + + align:start position:0% +typical but but to get you doubting + + + align:start position:0% +typical but but to get you doubting +again so that you don't trust anything + + align:start position:0% +again so that you don't trust anything + + + align:start position:0% +again so that you don't trust anything +uh + + align:start position:0% +uh + + + align:start position:0% +uh +100 Secrets identity this should be a + + align:start position:0% +100 Secrets identity this should be a + + + align:start position:0% +100 Secrets identity this should be a +best case scenario but it's not the + + align:start position:0% +best case scenario but it's not the + + + align:start position:0% +best case scenario but it's not the +enolase enzyme which catalyzes a carbon + + align:start position:0% +enolase enzyme which catalyzes a carbon + + + align:start position:0% +enolase enzyme which catalyzes a carbon +metabolism in most cells when it's + + align:start position:0% +metabolism in most cells when it's + + + align:start position:0% +metabolism in most cells when it's +expressed to high levels in a vertebrate + + align:start position:0% +expressed to high levels in a vertebrate + + + align:start position:0% +expressed to high levels in a vertebrate +like our friends this uh + + align:start position:0% +like our friends this uh + + + align:start position:0% +like our friends this uh +uh Marine tortoise turtle uh you have it + + align:start position:0% +uh Marine tortoise turtle uh you have it + + + align:start position:0% +uh Marine tortoise turtle uh you have it +turns into the major islands Christine + + align:start position:0% +turns into the major islands Christine + + + align:start position:0% +turns into the major islands Christine +and actually this is true of most + + align:start position:0% +and actually this is true of most + + + align:start position:0% +and actually this is true of most +vertebrates they have some kind of + + align:start position:0% +vertebrates they have some kind of + + + align:start position:0% +vertebrates they have some kind of +enzyme like a glycolytic enzyme which is + + align:start position:0% +enzyme like a glycolytic enzyme which is + + + align:start position:0% +enzyme like a glycolytic enzyme which is +overproduced and produce and Aggregates + + align:start position:0% +overproduced and produce and Aggregates + + + align:start position:0% +overproduced and produce and Aggregates +and makes a clear lens + + align:start position:0% +and makes a clear lens + + + align:start position:0% +and makes a clear lens +um more morphologically interesting + + align:start position:0% +um more morphologically interesting + + + align:start position:0% +um more morphologically interesting +feature which just focuses light + + align:start position:0% +feature which just focuses light + + + align:start position:0% +feature which just focuses light +completely new function by all those + + align:start position:0% +completely new function by all those + + + align:start position:0% +completely new function by all those +definitions of function no longer does + + align:start position:0% +definitions of function no longer does + + + align:start position:0% +definitions of function no longer does +the enzymatic activity does an optical + + align:start position:0% +the enzymatic activity does an optical + + + align:start position:0% +the enzymatic activity does an optical +activity instead another example we have + + align:start position:0% +activity instead another example we have + + + align:start position:0% +activity instead another example we have +100 sequence identity not something + + align:start position:0% +100 sequence identity not something + + + align:start position:0% +100 sequence identity not something +really distant homolog like 20 or 10 but + + align:start position:0% +really distant homolog like 20 or 10 but + + + align:start position:0% +really distant homolog like 20 or 10 but +100 sequence identity + + align:start position:0% +100 sequence identity + + + align:start position:0% +100 sequence identity +thyrodoxin which has evolved in redos + + align:start position:0% +thyrodoxin which has evolved in redos + + + align:start position:0% +thyrodoxin which has evolved in redos +reactions evolving flow hydros and other + + align:start position:0% +reactions evolving flow hydros and other + + + align:start position:0% +reactions evolving flow hydros and other +things + + align:start position:0% +things + + + align:start position:0% +things +uh in the right context with other + + align:start position:0% +uh in the right context with other + + + align:start position:0% +uh in the right context with other +proteins it can now be part of a DNA + + align:start position:0% +proteins it can now be part of a DNA + + + align:start position:0% +proteins it can now be part of a DNA +polymerase which when it bombs along the + + align:start position:0% +polymerase which when it bombs along the + + + align:start position:0% +polymerase which when it bombs along the +DNA it goes really without stopping with + + align:start position:0% +DNA it goes really without stopping with + + + align:start position:0% +DNA it goes really without stopping with +thyroid oxyn but it falls off if + + align:start position:0% +thyroid oxyn but it falls off if + + + align:start position:0% +thyroid oxyn but it falls off if +thyroduction isn't around that's not a + + align:start position:0% +thyroduction isn't around that's not a + + + align:start position:0% +thyroduction isn't around that's not a +redox function completely different + + align:start position:0% +redox function completely different + + + align:start position:0% +redox function completely different +biochemical function + + align:start position:0% +biochemical function + + + align:start position:0% +biochemical function +but like I say there will be a curve + + align:start position:0% +but like I say there will be a curve + + + align:start position:0% +but like I say there will be a curve +sometimes there will be very great + + align:start position:0% +sometimes there will be very great + + + align:start position:0% +sometimes there will be very great +hypothesis limitation that can come from + + align:start position:0% +hypothesis limitation that can come from + + + align:start position:0% +hypothesis limitation that can come from +very distant relatives + + align:start position:0% + + + + align:start position:0% + +these are another example more examples + + align:start position:0% +these are another example more examples + + + align:start position:0% +these are another example more examples +of the quantitative data that we will + + align:start position:0% +of the quantitative data that we will + + + align:start position:0% +of the quantitative data that we will +use to get hints at relationships among + + align:start position:0% +use to get hints at relationships among + + + align:start position:0% +use to get hints at relationships among +genes that that go up and down together + + align:start position:0% +genes that that go up and down together + + + align:start position:0% +genes that that go up and down together +um + + align:start position:0% +um + + + align:start position:0% +um +to form the basis of + + align:start position:0% +to form the basis of + + + align:start position:0% +to form the basis of +asking what is function not based just + + align:start position:0% +asking what is function not based just + + + align:start position:0% +asking what is function not based just +on sequence homology but based on a + + align:start position:0% +on sequence homology but based on a + + + align:start position:0% +on sequence homology but based on a +variety of quantitative data such as the + + align:start position:0% +variety of quantitative data such as the + + + align:start position:0% +variety of quantitative data such as the +RNA data and microarrays + + align:start position:0% +RNA data and microarrays + + + align:start position:0% +RNA data and microarrays +this is uh + + align:start position:0% +this is uh + + + align:start position:0% +this is uh +three more ways of looking at how we + + align:start position:0% +three more ways of looking at how we + + + align:start position:0% +three more ways of looking at how we +Define functions function definition + + align:start position:0% +Define functions function definition + + + align:start position:0% +Define functions function definition +number one is the effects of mutation on + + align:start position:0% +number one is the effects of mutation on + + + align:start position:0% +number one is the effects of mutation on +Fitness this is in a certain sense the + + align:start position:0% +Fitness this is in a certain sense the + + + align:start position:0% +Fitness this is in a certain sense the +oh what's this organism cares about the + + align:start position:0% +oh what's this organism cares about the + + + align:start position:0% +oh what's this organism cares about the +function of a gene product is how is it + + align:start position:0% +function of a gene product is how is it + + + align:start position:0% +function of a gene product is how is it +how many grandchildren am I going to + + align:start position:0% +how many grandchildren am I going to + + + align:start position:0% +how many grandchildren am I going to +have that's what it cares about and + + align:start position:0% +have that's what it cares about and + + + align:start position:0% +have that's what it cares about and +that's what shaped the function over + + align:start position:0% +that's what shaped the function over + + + align:start position:0% +that's what shaped the function over +time and so if we're going to understand + + align:start position:0% +time and so if we're going to understand + + + align:start position:0% +time and so if we're going to understand +any of the other fun on any of our other + + align:start position:0% +any of the other fun on any of our other + + + align:start position:0% +any of the other fun on any of our other +definition functions we have to at least + + align:start position:0% +definition functions we have to at least + + + align:start position:0% +definition functions we have to at least +give some attention to what shaped it + + align:start position:0% +give some attention to what shaped it + + + align:start position:0% +give some attention to what shaped it +over billions of years + + align:start position:0% +over billions of years + + + align:start position:0% +over billions of years +and over many different environments we + + align:start position:0% +and over many different environments we + + + align:start position:0% +and over many different environments we +need to have some feeling for the + + align:start position:0% +need to have some feeling for the + + + align:start position:0% +need to have some feeling for the +Ecology of these organisms the second + + align:start position:0% +Ecology of these organisms the second + + + align:start position:0% +Ecology of these organisms the second +definition is more commonly used one + + align:start position:0% +definition is more commonly used one + + + align:start position:0% +definition is more commonly used one +which is uh what is actually its + + align:start position:0% +which is uh what is actually its + + + align:start position:0% +which is uh what is actually its +function in a machine-like sense in the + + align:start position:0% +function in a machine-like sense in the + + + align:start position:0% +function in a machine-like sense in the +cogs and the wheels how does it function + + align:start position:0% +cogs and the wheels how does it function + + + align:start position:0% +cogs and the wheels how does it function +uh structurally what's the + + align:start position:0% +uh structurally what's the + + + align:start position:0% +uh structurally what's the +three-dimensional structure what's the + + align:start position:0% +three-dimensional structure what's the + + + align:start position:0% +three-dimensional structure what's the +mechanism + + align:start position:0% +mechanism + + + align:start position:0% +mechanism +the third function is more + + align:start position:0% +the third function is more + + + align:start position:0% +the third function is more +forward-looking not what good is it done + + align:start position:0% +forward-looking not what good is it done + + + align:start position:0% +forward-looking not what good is it done +to to organisms in the past but what + + align:start position:0% +to to organisms in the past but what + + + align:start position:0% +to to organisms in the past but what +good can it be to us in the future or to + + align:start position:0% +good can it be to us in the future or to + + + align:start position:0% +good can it be to us in the future or to +organisms other organisms in the future + + align:start position:0% +organisms other organisms in the future + + + align:start position:0% +organisms other organisms in the future +this may not involve + + align:start position:0% +this may not involve + + + align:start position:0% +this may not involve +reproducing the organism making copies + + align:start position:0% +reproducing the organism making copies + + + align:start position:0% +reproducing the organism making copies +of it it could be that there's some + + align:start position:0% +of it it could be that there's some + + + align:start position:0% +of it it could be that there's some +other engineering goal or objective + + align:start position:0% +other engineering goal or objective + + + align:start position:0% +other engineering goal or objective +function + + align:start position:0% +function + + + align:start position:0% +function +when we say that we've proven something + + align:start position:0% +when we say that we've proven something + + + align:start position:0% +when we say that we've proven something +we've proven uh biological hypothesis + + align:start position:0% +we've proven uh biological hypothesis + + + align:start position:0% +we've proven uh biological hypothesis +what we mean is given the Assumption + + align:start position:0% +what we mean is given the Assumption + + + align:start position:0% +what we mean is given the Assumption +it's a statistical statement the odds of + + align:start position:0% +it's a statistical statement the odds of + + + align:start position:0% +it's a statistical statement the odds of +hypothesis being wrong or less than five + + align:start position:0% +hypothesis being wrong or less than five + + + align:start position:0% +hypothesis being wrong or less than five +percent of the time + + align:start position:0% +percent of the time + + + align:start position:0% +percent of the time +keeping in mind + + align:start position:0% +keeping in mind + + + align:start position:0% +keeping in mind +hidden hypotheses and multiple + + align:start position:0% +hidden hypotheses and multiple + + + align:start position:0% +hidden hypotheses and multiple +hypotheses in genomics it's all too easy + + align:start position:0% +hypotheses in genomics it's all too easy + + + align:start position:0% +hypotheses in genomics it's all too easy +to collect a lot of data and therefore + + align:start position:0% +to collect a lot of data and therefore + + + align:start position:0% +to collect a lot of data and therefore +when you mine the data you can make a + + align:start position:0% +when you mine the data you can make a + + + align:start position:0% +when you mine the data you can make a +lot of hypotheses and you test them and + + align:start position:0% +lot of hypotheses and you test them and + + + align:start position:0% +lot of hypotheses and you test them and +you find you will find thousands of + + align:start position:0% +you find you will find thousands of + + + align:start position:0% +you find you will find thousands of +things which by themselves would be + + align:start position:0% +things which by themselves would be + + + align:start position:0% +things which by themselves would be +significant at the five percent level + + align:start position:0% +significant at the five percent level + + + align:start position:0% +significant at the five percent level +sort of the standard statistical test + + align:start position:0% +sort of the standard statistical test + + + align:start position:0% +sort of the standard statistical test +but you've got to uh + + align:start position:0% +but you've got to uh + + + align:start position:0% +but you've got to uh +correct for the number of hypotheses you + + align:start position:0% +correct for the number of hypotheses you + + + align:start position:0% +correct for the number of hypotheses you +implicitly or explicitly test we'll + + align:start position:0% +implicitly or explicitly test we'll + + + align:start position:0% +implicitly or explicitly test we'll +we'll mention this time and again in + + align:start position:0% +we'll mention this time and again in + + + align:start position:0% +we'll mention this time and again in +specific cases as we go forward + + align:start position:0% + + + + align:start position:0% + +the systems biology manifest as I + + align:start position:0% +the systems biology manifest as I + + + align:start position:0% +the systems biology manifest as I +mentioned earlier said had this little + + align:start position:0% +mentioned earlier said had this little + + + align:start position:0% +mentioned earlier said had this little +Loop where you would generate + + align:start position:0% +Loop where you would generate + + + align:start position:0% +Loop where you would generate +perturbations and test things and so + + align:start position:0% +perturbations and test things and so + + + align:start position:0% +perturbations and test things and so +forth but an alternative way rather than + + align:start position:0% +forth but an alternative way rather than + + + align:start position:0% +forth but an alternative way rather than +doing additional experiments is to if + + align:start position:0% +doing additional experiments is to if + + + align:start position:0% +doing additional experiments is to if +you really have bought ends fully into + + align:start position:0% +you really have bought ends fully into + + + align:start position:0% +you really have bought ends fully into +the system biology and you really have + + align:start position:0% +the system biology and you really have + + + align:start position:0% +the system biology and you really have +all the components and a systematic + + align:start position:0% +all the components and a systematic + + + align:start position:0% +all the components and a systematic +perturbations then you might be able to + + align:start position:0% +perturbations then you might be able to + + + align:start position:0% +perturbations then you might be able to +test a hypothesis generated by data + + align:start position:0% +test a hypothesis generated by data + + + align:start position:0% +test a hypothesis generated by data +mining one data set by going into + + align:start position:0% +mining one data set by going into + + + align:start position:0% +mining one data set by going into +another data set you need to ensure that + + align:start position:0% +another data set you need to ensure that + + + align:start position:0% +another data set you need to ensure that +they are independent and you need to + + align:start position:0% +they are independent and you need to + + + align:start position:0% +they are independent and you need to +ensure that the hypothesis uh itself + + align:start position:0% +ensure that the hypothesis uh itself + + + align:start position:0% +ensure that the hypothesis uh itself +came from the first data set and not the + + align:start position:0% +came from the first data set and not the + + + align:start position:0% +came from the first data set and not the +second when you go out and test it but + + align:start position:0% +second when you go out and test it but + + + align:start position:0% +second when you go out and test it but +that would be a pure data mining uh loop + + align:start position:0% +that would be a pure data mining uh loop + + + align:start position:0% +that would be a pure data mining uh loop +system file as you Loop now + + align:start position:0% +system file as you Loop now + + + align:start position:0% +system file as you Loop now +uh + + align:start position:0% +uh + + + align:start position:0% +uh +just like when we say we have a proof + + align:start position:0% +just like when we say we have a proof + + + align:start position:0% +just like when we say we have a proof +you should be distrusting of anybody who + + align:start position:0% +you should be distrusting of anybody who + + + align:start position:0% +you should be distrusting of anybody who +says I have an absolute proof what they + + align:start position:0% +says I have an absolute proof what they + + + align:start position:0% +says I have an absolute proof what they +really mean is a statistical uh + + align:start position:0% +really mean is a statistical uh + + + align:start position:0% +really mean is a statistical uh +statement so too when someone says when + + align:start position:0% +statement so too when someone says when + + + align:start position:0% +statement so too when someone says when +they refer to the quality of their data + + align:start position:0% +they refer to the quality of their data + + + align:start position:0% +they refer to the quality of their data +is this is the answer uh at the you know + + align:start position:0% +is this is the answer uh at the you know + + + align:start position:0% +is this is the answer uh at the you know +raw data level or what they really mean + + align:start position:0% +raw data level or what they really mean + + + align:start position:0% +raw data level or what they really mean +is that they're that they have some + + align:start position:0% +is that they're that they have some + + + align:start position:0% +is that they're that they have some +error level that they can quantitate + + align:start position:0% +error level that they can quantitate + + + align:start position:0% +error level that they can quantitate +and if this if you should be especially + + align:start position:0% +and if this if you should be especially + + + align:start position:0% +and if this if you should be especially +distrustful if someone doesn't uh + + align:start position:0% +distrustful if someone doesn't uh + + + align:start position:0% +distrustful if someone doesn't uh +attempt to give any feeling for that + + align:start position:0% +attempt to give any feeling for that + + + align:start position:0% +attempt to give any feeling for that +um not to say that everybody that gives + + align:start position:0% +um not to say that everybody that gives + + + align:start position:0% +um not to say that everybody that gives +error bars or air estimates is to be + + align:start position:0% +error bars or air estimates is to be + + + align:start position:0% +error bars or air estimates is to be +trusted but you get the idea so for DNA + + align:start position:0% +trusted but you get the idea so for DNA + + + align:start position:0% +trusted but you get the idea so for DNA +sequencing there's a standard of + + align:start position:0% +sequencing there's a standard of + + + align:start position:0% +sequencing there's a standard of +practice that was not always such but a + + align:start position:0% +practice that was not always such but a + + + align:start position:0% +practice that was not always such but a +a meeting in Bermuda it's called The + + align:start position:0% +a meeting in Bermuda it's called The + + + align:start position:0% +a meeting in Bermuda it's called The +Bermuda standards this is where it's the + + align:start position:0% +Bermuda standards this is where it's the + + + align:start position:0% +Bermuda standards this is where it's the +best place to establish standards uh is + + align:start position:0% +best place to establish standards uh is + + + align:start position:0% +best place to establish standards uh is +uh is uh + + align:start position:0% +uh is uh + + + align:start position:0% +uh is uh +99.99 + + align:start position:0% +99.99 + + + align:start position:0% +99.99 +accurate you can see they have very high + + align:start position:0% +accurate you can see they have very high + + + align:start position:0% +accurate you can see they have very high +standards in Bermuda and that but that's + + align:start position:0% +standards in Bermuda and that but that's + + + align:start position:0% +standards in Bermuda and that but that's +that's across the Genome Project + + align:start position:0% +that's across the Genome Project + + + align:start position:0% +that's across the Genome Project +um + + align:start position:0% +um + + + align:start position:0% +um +and you want to have come these are + + align:start position:0% +and you want to have come these are + + + align:start position:0% +and you want to have come these are +aspects that I think we got from + + align:start position:0% +aspects that I think we got from + + + align:start position:0% +aspects that I think we got from +genomics in addition to the Raw + + align:start position:0% +genomics in addition to the Raw + + + align:start position:0% +genomics in addition to the Raw +data it's got kind of an attitude the + + align:start position:0% +data it's got kind of an attitude the + + + align:start position:0% +data it's got kind of an attitude the +attitude is we can start looking at + + align:start position:0% +attitude is we can start looking at + + + align:start position:0% +attitude is we can start looking at +whole systems again uh Less on the + + align:start position:0% +whole systems again uh Less on the + + + align:start position:0% +whole systems again uh Less on the +individual Gene hypothesis uh driven + + align:start position:0% +individual Gene hypothesis uh driven + + + align:start position:0% +individual Gene hypothesis uh driven +standard NIH + + align:start position:0% +standard NIH + + + align:start position:0% +standard NIH +Grant proposals that predated the Genome + + align:start position:0% +Grant proposals that predated the Genome + + + align:start position:0% +Grant proposals that predated the Genome +Project now you can do less hypothesis + + align:start position:0% +Project now you can do less hypothesis + + + align:start position:0% +Project now you can do less hypothesis +driven you can do Data Mining and so on + + align:start position:0% +driven you can do Data Mining and so on + + + align:start position:0% +driven you can do Data Mining and so on +we're we've also inherited the concept + + align:start position:0% +we're we've also inherited the concept + + + align:start position:0% +we're we've also inherited the concept +of automation the modeling and + + align:start position:0% +of automation the modeling and + + + align:start position:0% +of automation the modeling and +completion completion is something which + + align:start position:0% +completion completion is something which + + + align:start position:0% +completion completion is something which +still is not the reduced to practice for + + align:start position:0% +still is not the reduced to practice for + + + align:start position:0% +still is not the reduced to practice for +functional genomics but it has been + + align:start position:0% +functional genomics but it has been + + + align:start position:0% +functional genomics but it has been +reduced to practice for sequencing and + + align:start position:0% +reduced to practice for sequencing and + + + align:start position:0% +reduced to practice for sequencing and +there is hope that we can we can + + align:start position:0% +there is hope that we can we can + + + align:start position:0% +there is hope that we can we can +approach it for functional genomics + + align:start position:0% +approach it for functional genomics + + + align:start position:0% +approach it for functional genomics +be careful using the word impossible + + align:start position:0% +be careful using the word impossible + + + align:start position:0% +be careful using the word impossible +there certainly are things that appear + + align:start position:0% +there certainly are things that appear + + + align:start position:0% +there certainly are things that appear +not to be cost effective at any given + + align:start position:0% +not to be cost effective at any given + + + align:start position:0% +not to be cost effective at any given +moment but uh but technology is moving + + align:start position:0% +moment but uh but technology is moving + + + align:start position:0% +moment but uh but technology is moving +quickly enough remember those uh greater + + align:start position:0% +quickly enough remember those uh greater + + + align:start position:0% +quickly enough remember those uh greater +than exponential Curves in the last + + align:start position:0% +than exponential Curves in the last + + + align:start position:0% +than exponential Curves in the last +lecture there are Technologies arriving + + align:start position:0% +lecture there are Technologies arriving + + + align:start position:0% +lecture there are Technologies arriving +that make things uh suddenly become cost + + align:start position:0% +that make things uh suddenly become cost + + + align:start position:0% +that make things uh suddenly become cost +effective + + align:start position:0% +effective + + + align:start position:0% +effective +and so and that's a particularly + + align:start position:0% +and so and that's a particularly + + + align:start position:0% +and so and that's a particularly +important uh warning when you're when + + align:start position:0% +important uh warning when you're when + + + align:start position:0% +important uh warning when you're when +you're designing a computational method + + align:start position:0% +you're designing a computational method + + + align:start position:0% +you're designing a computational method +that will uh compete with an + + align:start position:0% +that will uh compete with an + + + align:start position:0% +that will uh compete with an +experimental method is the experimental + + align:start position:0% +experimental method is the experimental + + + align:start position:0% +experimental method is the experimental +method suddenly becomes cost effective + + align:start position:0% +method suddenly becomes cost effective + + + align:start position:0% +method suddenly becomes cost effective +then you need to uh revise your + + align:start position:0% +then you need to uh revise your + + + align:start position:0% +then you need to uh revise your +computational goals + + align:start position:0% +computational goals + + + align:start position:0% +computational goals +we have types of mutations that we've + + align:start position:0% +we have types of mutations that we've + + + align:start position:0% +we have types of mutations that we've +talked about you have a null mutation + + align:start position:0% +talked about you have a null mutation + + + align:start position:0% +talked about you have a null mutation +for example phenylketonuria which is uh + + align:start position:0% +for example phenylketonuria which is uh + + + align:start position:0% +for example phenylketonuria which is uh +tested in newborns + + align:start position:0% +tested in newborns + + + align:start position:0% +tested in newborns +in almost all newborns that are born in + + align:start position:0% +in almost all newborns that are born in + + + align:start position:0% +in almost all newborns that are born in +the United States and certainly + + align:start position:0% +the United States and certainly + + + align:start position:0% +the United States and certainly +Massachusetts + + align:start position:0% +Massachusetts + + + align:start position:0% +Massachusetts +um this this is a very serious source of + + align:start position:0% +um this this is a very serious source of + + + align:start position:0% +um this this is a very serious source of +mental retardation completely wiping out + + align:start position:0% +mental retardation completely wiping out + + + align:start position:0% +mental retardation completely wiping out +that Gene small dosage effects like a + + align:start position:0% +that Gene small dosage effects like a + + + align:start position:0% +that Gene small dosage effects like a +1.5 fold effect that we talked about in + + align:start position:0% +1.5 fold effect that we talked about in + + + align:start position:0% +1.5 fold effect that we talked about in +trisomies like down syndrome are + + align:start position:0% +trisomies like down syndrome are + + + align:start position:0% +trisomies like down syndrome are +important you have conditional mutants + + align:start position:0% +important you have conditional mutants + + + align:start position:0% +important you have conditional mutants +classically temperature sensitivity of a + + align:start position:0% +classically temperature sensitivity of a + + + align:start position:0% +classically temperature sensitivity of a +mutation meaning the protein unfolds or + + align:start position:0% +mutation meaning the protein unfolds or + + + align:start position:0% +mutation meaning the protein unfolds or +more + + align:start position:0% +more + + + align:start position:0% +more +recent enthusiasm for chemicals a + + align:start position:0% +recent enthusiasm for chemicals a + + + align:start position:0% +recent enthusiasm for chemicals a +mutation which depends upon a chemical + + align:start position:0% +mutation which depends upon a chemical + + + align:start position:0% +mutation which depends upon a chemical +for producing its phenotype you can not + + align:start position:0% +for producing its phenotype you can not + + + align:start position:0% +for producing its phenotype you can not +only have these things that affect + + align:start position:0% +only have these things that affect + + + align:start position:0% +only have these things that affect +dosage or condition or + + align:start position:0% +dosage or condition or + + + align:start position:0% +dosage or condition or +a complete knockout you can have a new + + align:start position:0% +a complete knockout you can have a new + + + align:start position:0% +a complete knockout you can have a new +function to obtained for changing a + + align:start position:0% +function to obtained for changing a + + + align:start position:0% +function to obtained for changing a +ligand specificity or changing the + + align:start position:0% +ligand specificity or changing the + + + align:start position:0% +ligand specificity or changing the +aggregation of a protein here in the + + align:start position:0% +aggregation of a protein here in the + + + align:start position:0% +aggregation of a protein here in the +background or how the how a change in + + align:start position:0% +background or how the how a change in + + + align:start position:0% +background or how the how a change in +the hemoglobin which normally transports + + align:start position:0% +the hemoglobin which normally transports + + + align:start position:0% +the hemoglobin which normally transports +oxygen to change the morphology of a + + align:start position:0% +oxygen to change the morphology of a + + + align:start position:0% +oxygen to change the morphology of a +cell and hence the function in + + align:start position:0% +cell and hence the function in + + + align:start position:0% +cell and hence the function in +transporting oxygen + + align:start position:0% +transporting oxygen + + + align:start position:0% +transporting oxygen +I just want to end on two slides on the + + align:start position:0% +I just want to end on two slides on the + + + align:start position:0% +I just want to end on two slides on the +on how you can + + align:start position:0% +on how you can + + + align:start position:0% +on how you can +represent the of the + + align:start position:0% +represent the of the + + + align:start position:0% +represent the of the +competition among cells or among + + align:start position:0% +competition among cells or among + + + align:start position:0% +competition among cells or among +organisms which represents the darwinian + + align:start position:0% +organisms which represents the darwinian + + + align:start position:0% +organisms which represents the darwinian +function function number one a few + + align:start position:0% +function function number one a few + + + align:start position:0% +function function number one a few +slides back + + align:start position:0% +slides back + + + align:start position:0% +slides back +here you have mutants in a population + + align:start position:0% +here you have mutants in a population + + + align:start position:0% +here you have mutants in a population +selection excellent populations and + + align:start position:0% +selection excellent populations and + + + align:start position:0% +selection excellent populations and +mutations are tagged by definition by + + align:start position:0% +mutations are tagged by definition by + + + align:start position:0% +mutations are tagged by definition by +the nucleic acid if you can + + align:start position:0% +the nucleic acid if you can + + + align:start position:0% +the nucleic acid if you can +if you can uh + + align:start position:0% +if you can uh + + + align:start position:0% +if you can uh +change the if you can use the tags you + + align:start position:0% +change the if you can use the tags you + + + align:start position:0% +change the if you can use the tags you +make a pool of such mutants either + + align:start position:0% +make a pool of such mutants either + + + align:start position:0% +make a pool of such mutants either +naturally occurring population and when + + align:start position:0% +naturally occurring population and when + + + align:start position:0% +naturally occurring population and when +these pools are subjected to selections + + align:start position:0% +these pools are subjected to selections + + + align:start position:0% +these pools are subjected to selections +natural or comp complex or simple or in + + align:start position:0% +natural or comp complex or simple or in + + + align:start position:0% +natural or comp complex or simple or in +the laboratory you can now read out + + align:start position:0% +the laboratory you can now read out + + + align:start position:0% +the laboratory you can now read out +these tags uh in many in many of the + + align:start position:0% +these tags uh in many in many of the + + + align:start position:0% +these tags uh in many in many of the +quantitative ways we've talked about + + align:start position:0% +quantitative ways we've talked about + + + align:start position:0% +quantitative ways we've talked about +electrophoresis Mass spectrometry arrays + + align:start position:0% +electrophoresis Mass spectrometry arrays + + + align:start position:0% +electrophoresis Mass spectrometry arrays +so on and these and as you go through + + align:start position:0% +so on and these and as you go through + + + align:start position:0% +so on and these and as you go through +more + + align:start position:0% +more + + + align:start position:0% +more +rounds of selection you will get you'll + + align:start position:0% +rounds of selection you will get you'll + + + align:start position:0% +rounds of selection you will get you'll +eventually pick the winner which is the + + align:start position:0% +eventually pick the winner which is the + + + align:start position:0% +eventually pick the winner which is the +the most highly selected of the uh + + align:start position:0% +the most highly selected of the uh + + + align:start position:0% +the most highly selected of the uh +mutations + + align:start position:0% +mutations + + + align:start position:0% +mutations +the winner uh or you might have a + + align:start position:0% +the winner uh or you might have a + + + align:start position:0% +the winner uh or you might have a +mixture if you go through a very limited + + align:start position:0% +mixture if you go through a very limited + + + align:start position:0% +mixture if you go through a very limited +number of rounds this will follow the + + align:start position:0% +number of rounds this will follow the + + + align:start position:0% +number of rounds this will follow the +exponential curve that we had here + + align:start position:0% +exponential curve that we had here + + + align:start position:0% +exponential curve that we had here +whether it's exponential decay or + + align:start position:0% +whether it's exponential decay or + + + align:start position:0% +whether it's exponential decay or +exponential growth you could have a very + + align:start position:0% +exponential growth you could have a very + + + align:start position:0% +exponential growth you could have a very +subtle difference in growth due to the + + align:start position:0% +subtle difference in growth due to the + + + align:start position:0% +subtle difference in growth due to the +function of that mutated + + align:start position:0% +function of that mutated + + + align:start position:0% +function of that mutated +Gene product + + align:start position:0% +Gene product + + + align:start position:0% +Gene product +but that that is that that small say one + + align:start position:0% +but that that is that that small say one + + + align:start position:0% +but that that is that that small say one +percent turns into complete all or none + + align:start position:0% +percent turns into complete all or none + + + align:start position:0% +percent turns into complete all or none +replacement uh if you have enough + + align:start position:0% +replacement uh if you have enough + + + align:start position:0% +replacement uh if you have enough +Generations this is the awesome power + + align:start position:0% +Generations this is the awesome power + + + align:start position:0% +Generations this is the awesome power +the exponential that we talked about + + align:start position:0% +the exponential that we talked about + + + align:start position:0% +the exponential that we talked about +last time + + align:start position:0% +last time + + + align:start position:0% +last time +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and this + + align:start position:0% +and this + + + align:start position:0% +and this +in real world and also in the laboratory + + align:start position:0% +in real world and also in the laboratory + + + align:start position:0% +in real world and also in the laboratory +you can think of this as going over a + + align:start position:0% +you can think of this as going over a + + + align:start position:0% +you can think of this as going over a +variety of environments e over different + + align:start position:0% +variety of environments e over different + + + align:start position:0% +variety of environments e over different +times so each the time you spend in each + + align:start position:0% +times so each the time you spend in each + + + align:start position:0% +times so each the time you spend in each +of these different environments is a is + + align:start position:0% +of these different environments is a is + + + align:start position:0% +of these different environments is a is +a it has a you know some unit that + + align:start position:0% +a it has a you know some unit that + + + align:start position:0% +a it has a you know some unit that +happens in natural environments you'll + + align:start position:0% +happens in natural environments you'll + + + align:start position:0% +happens in natural environments you'll +have you'll spend say more time in one + + align:start position:0% +have you'll spend say more time in one + + + align:start position:0% +have you'll spend say more time in one +condition than another and the selection + + align:start position:0% +condition than another and the selection + + + align:start position:0% +condition than another and the selection +coefficients are a simple sum and this + + align:start position:0% +coefficients are a simple sum and this + + + align:start position:0% +coefficients are a simple sum and this +exponential gives you the ratio of the + + align:start position:0% +exponential gives you the ratio of the + + + align:start position:0% +exponential gives you the ratio of the +organisms here's some references on this + + align:start position:0% +organisms here's some references on this + + + align:start position:0% +organisms here's some references on this +and I urge you to take a look at these + + align:start position:0% +and I urge you to take a look at these + + + align:start position:0% +and I urge you to take a look at these +uh where you where actual experiments + + align:start position:0% +uh where you where actual experiments + + + align:start position:0% +uh where you where actual experiments +have been done uh getting these and + + align:start position:0% +have been done uh getting these and + + + align:start position:0% +have been done uh getting these and +we'll come back to this later in the + + align:start position:0% +we'll come back to this later in the + + + align:start position:0% +we'll come back to this later in the +course + + align:start position:0% +course + + + align:start position:0% +course +okay so uh this is the the end of this + + align:start position:0% +okay so uh this is the the end of this + + + align:start position:0% +okay so uh this is the the end of this +uh lecture number two thank you very + + align:start position:0% +uh lecture number two thank you very + + + align:start position:0% +uh lecture number two thank you very +much + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/_ZVnrpjI_VU.txt b/_ZVnrpjI_VU.txt new file mode 100644 index 0000000000000000000000000000000000000000..460a1211393ac37bb2fd22786ca88824e958f560 --- /dev/null +++ b/_ZVnrpjI_VU.txt @@ -0,0 +1,2115 @@ +align:start position:0% + +it's like a file sharing system like + + align:start position:0% +it's like a file sharing system like + + + align:start position:0% +it's like a file sharing system like +Dropbox except you manually take care of + + align:start position:0% +Dropbox except you manually take care of + + + align:start position:0% +Dropbox except you manually take care of +the files yourself and you worry about + + align:start position:0% +the files yourself and you worry about + + + align:start position:0% +the files yourself and you worry about +merge conflicts so if in Dropbox you and + + align:start position:0% +merge conflicts so if in Dropbox you and + + + align:start position:0% +merge conflicts so if in Dropbox you and +your collaborator added a document at + + align:start position:0% +your collaborator added a document at + + + align:start position:0% +your collaborator added a document at +the same time it tries to save both and + + align:start position:0% +the same time it tries to save both and + + + align:start position:0% +the same time it tries to save both and +it goes ah something's wrong and it + + align:start position:0% +it goes ah something's wrong and it + + + align:start position:0% +it goes ah something's wrong and it +makes one that says conflicted copy and + + align:start position:0% +makes one that says conflicted copy and + + + align:start position:0% +makes one that says conflicted copy and +github is a way to it does a similar + + align:start position:0% +github is a way to it does a similar + + + align:start position:0% +github is a way to it does a similar +thing but then it hands it back to you + + align:start position:0% +thing but then it hands it back to you + + + align:start position:0% +thing but then it hands it back to you +and it says I'm not going to save that + + align:start position:0% +and it says I'm not going to save that + + + align:start position:0% +and it says I'm not going to save that +conflicted copy you need to tell me what + + align:start position:0% +conflicted copy you need to tell me what + + + align:start position:0% +conflicted copy you need to tell me what +to do to resolve that so that I only + + align:start position:0% +to do to resolve that so that I only + + + align:start position:0% +to do to resolve that so that I only +have one version of each file and it's + + align:start position:0% +have one version of each file and it's + + + align:start position:0% +have one version of each file and it's +the master version so that's github in a + + align:start position:0% +the master version so that's github in a + + + align:start position:0% +the master version so that's github in a +nutshell is just a way to share files + + align:start position:0% +nutshell is just a way to share files + + + align:start position:0% +nutshell is just a way to share files +with other people collaboratively + + align:start position:0% +with other people collaboratively + + + align:start position:0% +with other people collaboratively +without overwriting other people's stuff + + align:start position:0% +without overwriting other people's stuff + + + align:start position:0% +without overwriting other people's stuff +and without having conflicts happen + + align:start position:0% +and without having conflicts happen + + + align:start position:0% +and without having conflicts happen +inside of the cloud where you're able to + + align:start position:0% +inside of the cloud where you're able to + + + align:start position:0% +inside of the cloud where you're able to +share this document and then briefly how + + align:start position:0% +share this document and then briefly how + + + align:start position:0% +share this document and then briefly how +to edit pages so all right so what does + + align:start position:0% +to edit pages so all right so what does + + + align:start position:0% +to edit pages so all right so what does +github does anyone want to explain this + + align:start position:0% +github does anyone want to explain this + + + align:start position:0% +github does anyone want to explain this +or get + + align:start position:0% + + + + align:start position:0% + +the wild guests + + align:start position:0% + + + + align:start position:0% + +okay so github is a few things github is + + align:start position:0% +okay so github is a few things github is + + + align:start position:0% +okay so github is a few things github is +a web-based platform a website for + + align:start position:0% +a web-based platform a website for + + + align:start position:0% +a web-based platform a website for +sharing code sharing software code the + + align:start position:0% +sharing code sharing software code the + + + align:start position:0% +sharing code sharing software code the +source code is software so it's created + + align:start position:0% +source code is software so it's created + + + align:start position:0% +source code is software so it's created +for developers to collaborate on code + + align:start position:0% +for developers to collaborate on code + + + align:start position:0% +for developers to collaborate on code +some a lot of the code on there is open + + align:start position:0% +some a lot of the code on there is open + + + align:start position:0% +some a lot of the code on there is open +source code like code that the source + + align:start position:0% +source code like code that the source + + + align:start position:0% +source code like code that the source +code is freely available to look at and + + align:start position:0% +code is freely available to look at and + + + align:start position:0% +code is freely available to look at and +yeah so basically it's a website where + + align:start position:0% +yeah so basically it's a website where + + + align:start position:0% +yeah so basically it's a website where +you can navigate other people's code you + + align:start position:0% +you can navigate other people's code you + + + align:start position:0% +you can navigate other people's code you +can collaborate on the same project yeah + + align:start position:0% +can collaborate on the same project yeah + + + align:start position:0% +can collaborate on the same project yeah +and you can also just look at other + + align:start position:0% +and you can also just look at other + + + align:start position:0% +and you can also just look at other +people's projects you can submit bug + + align:start position:0% +people's projects you can submit bug + + + align:start position:0% +people's projects you can submit bug +reports to projects alright so yes so + + align:start position:0% +reports to projects alright so yes so + + + align:start position:0% +reports to projects alright so yes so +github is this sort of community the + + align:start position:0% +github is this sort of community the + + + align:start position:0% +github is this sort of community the +other thing it is is it's a piece of + + align:start position:0% +other thing it is is it's a piece of + + + align:start position:0% +other thing it is is it's a piece of +software based on technology called the + + align:start position:0% +software based on technology called the + + + align:start position:0% +software based on technology called the +git GDIT + + align:start position:0% + + + + align:start position:0% + +get gets so get there's a piece of + + align:start position:0% +get gets so get there's a piece of + + + align:start position:0% +get gets so get there's a piece of +software that lets you collaborate + + align:start position:0% +software that lets you collaborate + + + align:start position:0% +software that lets you collaborate +musically lets you share source code and + + align:start position:0% +musically lets you share source code and + + + align:start position:0% +musically lets you share source code and +github kind of extends that by making a + + align:start position:0% +github kind of extends that by making a + + + align:start position:0% +github kind of extends that by making a +pretty website and a few other things + + align:start position:0% + + + + align:start position:0% + +yeah so what ha so yeah git is a piece + + align:start position:0% +yeah so what ha so yeah git is a piece + + + align:start position:0% +yeah so what ha so yeah git is a piece +of software called version control + + align:start position:0% +of software called version control + + + align:start position:0% +of software called version control +hasn't even heard that term before yeah + + align:start position:0% +hasn't even heard that term before yeah + + + align:start position:0% +hasn't even heard that term before yeah +what does anyone want explain that term + + align:start position:0% + + + + align:start position:0% + +it's is a very fancy way of saying + + align:start position:0% +it's is a very fancy way of saying + + + align:start position:0% +it's is a very fancy way of saying +keeping a history and storing multiple + + align:start position:0% +keeping a history and storing multiple + + + align:start position:0% +keeping a history and storing multiple +versions of things so for example say + + align:start position:0% +versions of things so for example say + + + align:start position:0% +versions of things so for example say +you're working on some sort of document + + align:start position:0% + + + + align:start position:0% + +maybe a really important essay so this + + align:start position:0% +maybe a really important essay so this + + + align:start position:0% +maybe a really important essay so this +is my my really important my essay on + + align:start position:0% +is my my really important my essay on + + + align:start position:0% +is my my really important my essay on +bugs by Andrea okay so you're working on + + align:start position:0% +bugs by Andrea okay so you're working on + + + align:start position:0% +bugs by Andrea okay so you're working on +this essay you save it sa right then you + + align:start position:0% +this essay you save it sa right then you + + + align:start position:0% +this essay you save it sa right then you +make some changes + + align:start position:0% + + + + align:start position:0% + +alright you save it again and then + + align:start position:0% +alright you save it again and then + + + align:start position:0% +alright you save it again and then +you're like oh it looks so different now + + align:start position:0% +you're like oh it looks so different now + + + align:start position:0% +you're like oh it looks so different now +so one thing you'll do is once you have + + align:start position:0% +so one thing you'll do is once you have + + + align:start position:0% +so one thing you'll do is once you have +a version you like maybe you'll say + + align:start position:0% + + + + align:start position:0% + +maybe you'll take that version and let's + + align:start position:0% +maybe you'll take that version and let's + + + align:start position:0% +maybe you'll take that version and let's +make a copy of it let's call it like v1 + + align:start position:0% +make a copy of it let's call it like v1 + + + align:start position:0% +make a copy of it let's call it like v1 +one version one and then let's start + + align:start position:0% +one version one and then let's start + + + align:start position:0% +one version one and then let's start +working on version 2 so if we like mess + + align:start position:0% +working on version 2 so if we like mess + + + align:start position:0% +working on version 2 so if we like mess +something up we still have that first + + align:start position:0% +something up we still have that first + + + align:start position:0% +something up we still have that first +version and then it's getting really + + align:start position:0% +version and then it's getting really + + + align:start position:0% +version and then it's getting really +good right so then at this point we we + + align:start position:0% +good right so then at this point we we + + + align:start position:0% +good right so then at this point we we +save our version to let's say let's call + + align:start position:0% +save our version to let's say let's call + + + align:start position:0% +save our version to let's say let's call +this one final + + align:start position:0% + + + + align:start position:0% + +right so so yeah as you work on like + + align:start position:0% +right so so yeah as you work on like + + + align:start position:0% +right so so yeah as you work on like +multiple versions of a document you want + + align:start position:0% +multiple versions of a document you want + + + align:start position:0% +multiple versions of a document you want +to like save different versions in case + + align:start position:0% +to like save different versions in case + + + align:start position:0% +to like save different versions in case +in case like you mess out so you might + + align:start position:0% +in case like you mess out so you might + + + align:start position:0% +in case like you mess out so you might +have done that with like an essay before + + align:start position:0% + + + + align:start position:0% + +you might like submit an essay it's a + + align:start position:0% +you might like submit an essay it's a + + + align:start position:0% +you might like submit an essay it's a +professor they give you back a different + + align:start position:0% +professor they give you back a different + + + align:start position:0% +professor they give you back a different +version with corrected changes an + + align:start position:0% +version with corrected changes an + + + align:start position:0% +version with corrected changes an +annotated version so version control and + + align:start position:0% +annotated version so version control and + + + align:start position:0% +annotated version so version control and +software is just a fancy way of saying + + align:start position:0% +software is just a fancy way of saying + + + align:start position:0% +software is just a fancy way of saying +the same thing it's making multiple + + align:start position:0% +the same thing it's making multiple + + + align:start position:0% +the same thing it's making multiple +versions of things that you can go back + + align:start position:0% +versions of things that you can go back + + + align:start position:0% +versions of things that you can go back +to the thing with get though is you + + align:start position:0% +to the thing with get though is you + + + align:start position:0% +to the thing with get though is you +don't actually have to do what I just + + align:start position:0% +don't actually have to do what I just + + + align:start position:0% +don't actually have to do what I just +did it does all that automatically for + + align:start position:0% +did it does all that automatically for + + + align:start position:0% +did it does all that automatically for +you so yes so and that's similar to has + + align:start position:0% +you so yes so and that's similar to has + + + align:start position:0% +you so yes so and that's similar to has +anyone heard of time machine for your + + align:start position:0% +anyone heard of time machine for your + + + align:start position:0% +anyone heard of time machine for your +Apple so time machine on OSX is a + + align:start position:0% +Apple so time machine on OSX is a + + + align:start position:0% +Apple so time machine on OSX is a +software product but basically it backs + + align:start position:0% +software product but basically it backs + + + align:start position:0% +software product but basically it backs +up your computer every hour and then if + + align:start position:0% +up your computer every hour and then if + + + align:start position:0% +up your computer every hour and then if +something messes up you can restore your + + align:start position:0% +something messes up you can restore your + + + align:start position:0% +something messes up you can restore your +computer to an earlier version it has + + align:start position:0% +computer to an earlier version it has + + + align:start position:0% +computer to an earlier version it has +yeah it has this nice little interface + + align:start position:0% +yeah it has this nice little interface + + + align:start position:0% +yeah it has this nice little interface +like with a little time machine you can + + align:start position:0% +like with a little time machine you can + + + align:start position:0% +like with a little time machine you can +like go back and look at previous + + align:start position:0% +like go back and look at previous + + + align:start position:0% +like go back and look at previous +versions of your computer github is + + align:start position:0% +versions of your computer github is + + + align:start position:0% +versions of your computer github is +really similar it's very similar except + + align:start position:0% +really similar it's very similar except + + + align:start position:0% +really similar it's very similar except +it's like sort of tuned for working well + + align:start position:0% +it's like sort of tuned for working well + + + align:start position:0% +it's like sort of tuned for working well +with source code so it has a lot of + + align:start position:0% +with source code so it has a lot of + + + align:start position:0% +with source code so it has a lot of +other features that are useful for + + align:start position:0% +other features that are useful for + + + align:start position:0% +other features that are useful for +software developers so if you're + + align:start position:0% +software developers so if you're + + + align:start position:0% +software developers so if you're +programming eventually you will have to + + align:start position:0% +programming eventually you will have to + + + align:start position:0% +programming eventually you will have to +learn get at some point and github is + + align:start position:0% +learn get at some point and github is + + + align:start position:0% +learn get at some point and github is +like the most popular way of using git + + align:start position:0% +like the most popular way of using git + + + align:start position:0% +like the most popular way of using git +so that's why + + align:start position:0% +so that's why + + + align:start position:0% +so that's why +we'll kind of treat them as almost the + + align:start position:0% +we'll kind of treat them as almost the + + + align:start position:0% +we'll kind of treat them as almost the +same thing so yeah so let's take a look + + align:start position:0% +same thing so yeah so let's take a look + + + align:start position:0% +same thing so yeah so let's take a look +so the way github organizes things is + + align:start position:0% + + + + align:start position:0% + +has these things called repositories and + + align:start position:0% +has these things called repositories and + + + align:start position:0% +has these things called repositories and +a repository is sort of just like you + + align:start position:0% +a repository is sort of just like you + + + align:start position:0% +a repository is sort of just like you +could think of it as like a folder or a + + align:start position:0% +could think of it as like a folder or a + + + align:start position:0% +could think of it as like a folder or a +project so every like a different + + align:start position:0% +project so every like a different + + + align:start position:0% +project so every like a different +project you'd want the different + + align:start position:0% +project you'd want the different + + + align:start position:0% +project you'd want the different +repository so for this course website we + + align:start position:0% +repository so for this course website we + + + align:start position:0% +repository so for this course website we +have one called mounds and money's right + + align:start position:0% +have one called mounds and money's right + + + align:start position:0% +have one called mounds and money's right +so where is that um so yeah one of the + + align:start position:0% +so where is that um so yeah one of the + + + align:start position:0% +so where is that um so yeah one of the +things github does is it provides this + + align:start position:0% +things github does is it provides this + + + align:start position:0% +things github does is it provides this +like fancy homepage for your projects so + + align:start position:0% +like fancy homepage for your projects so + + + align:start position:0% +like fancy homepage for your projects so +you can like document your projects on + + align:start position:0% +you can like document your projects on + + + align:start position:0% +you can like document your projects on +the home page but basically so github + + align:start position:0% +the home page but basically so github + + + align:start position:0% +the home page but basically so github +has a few ways of interacting with it + + align:start position:0% +has a few ways of interacting with it + + + align:start position:0% +has a few ways of interacting with it +you can look at your files from the web + + align:start position:0% +you can look at your files from the web + + + align:start position:0% +you can look at your files from the web +interface github.com there's also like + + align:start position:0% +interface github.com there's also like + + + align:start position:0% +interface github.com there's also like +text-based + + align:start position:0% +text-based + + + align:start position:0% +text-based +interfaces and a visual interface github + + align:start position:0% +interfaces and a visual interface github + + + align:start position:0% +interfaces and a visual interface github +desktop which will use shortly yeah so a + + align:start position:0% +desktop which will use shortly yeah so a + + + align:start position:0% +desktop which will use shortly yeah so a +few things to note so this is the + + align:start position:0% +few things to note so this is the + + + align:start position:0% +few things to note so this is the +current latest version of your files + + align:start position:0% +current latest version of your files + + + align:start position:0% +current latest version of your files +this is kind of a view of the latest + + align:start position:0% +this is kind of a view of the latest + + + align:start position:0% +this is kind of a view of the latest +version unlike time machine it doesn't + + align:start position:0% +version unlike time machine it doesn't + + + align:start position:0% +version unlike time machine it doesn't +automatically create a new version every + + align:start position:0% +automatically create a new version every + + + align:start position:0% +automatically create a new version every +hour and if you use dropbox dropbox + + align:start position:0% +hour and if you use dropbox dropbox + + + align:start position:0% +hour and if you use dropbox dropbox +creates a new version of their file + + align:start position:0% +creates a new version of their file + + + align:start position:0% +creates a new version of their file +every time you change it github does not + + align:start position:0% +every time you change it github does not + + + align:start position:0% +every time you change it github does not +do that because it wants you to + + align:start position:0% +do that because it wants you to + + + align:start position:0% +do that because it wants you to +explicitly say when you've made + + align:start position:0% +explicitly say when you've made + + + align:start position:0% +explicitly say when you've made +a working change because if you're + + align:start position:0% +a working change because if you're + + + align:start position:0% +a working change because if you're +changing a piece of software you might + + align:start position:0% +changing a piece of software you might + + + align:start position:0% +changing a piece of software you might +change three or four files until you + + align:start position:0% +change three or four files until you + + + align:start position:0% +change three or four files until you +have a working next version of your + + align:start position:0% +have a working next version of your + + + align:start position:0% +have a working next version of your +software so you basically have to tell + + align:start position:0% +software so you basically have to tell + + + align:start position:0% +software so you basically have to tell +git every time you want to you have a + + align:start position:0% +git every time you want to you have a + + + align:start position:0% +git every time you want to you have a +new version that works + + align:start position:0% +new version that works + + + align:start position:0% +new version that works +that's called a commit so the commits + + align:start position:0% +that's called a commit so the commits + + + align:start position:0% +that's called a commit so the commits +are basically the history of every time + + align:start position:0% +are basically the history of every time + + + align:start position:0% +are basically the history of every time +you've made a change until it talked + + align:start position:0% +you've made a change until it talked + + + align:start position:0% +you've made a change until it talked +about it yes yeah yes I do yes yeah you + + align:start position:0% +about it yes yeah yes I do yes yeah you + + + align:start position:0% +about it yes yeah yes I do yes yeah you +will notice a few things there's a + + align:start position:0% +will notice a few things there's a + + + align:start position:0% +will notice a few things there's a +little lock icon and there is also this + + align:start position:0% +little lock icon and there is also this + + + align:start position:0% +little lock icon and there is also this +text that says private so yeah until I + + align:start position:0% +text that says private so yeah until I + + + align:start position:0% +text that says private so yeah until I +add you you will not be able to see this + + align:start position:0% +add you you will not be able to see this + + + align:start position:0% +add you you will not be able to see this +URL + + align:start position:0% +URL + + + align:start position:0% +URL +yeah all right twist my arm yes yes so + + align:start position:0% +yeah all right twist my arm yes yes so + + + align:start position:0% +yeah all right twist my arm yes yes so +yeah at some point I will ask you okay + + align:start position:0% +yeah at some point I will ask you okay + + + align:start position:0% +yeah at some point I will ask you okay +so yeah so the commits are basically the + + align:start position:0% +so yeah so the commits are basically the + + + align:start position:0% +so yeah so the commits are basically the +history it's good to name them well so I + + align:start position:0% +history it's good to name them well so I + + + align:start position:0% +history it's good to name them well so I +said linked to electronic books and + + align:start position:0% +said linked to electronic books and + + + align:start position:0% +said linked to electronic books and +schedule so that's when I added this + + align:start position:0% +schedule so that's when I added this + + + align:start position:0% +schedule so that's when I added this +schedule to the website + + align:start position:0% + + + + align:start position:0% + +added group project example I was five + + align:start position:0% +added group project example I was five + + + align:start position:0% +added group project example I was five +hours ago so that's when I added this + + align:start position:0% +hours ago so that's when I added this + + + align:start position:0% +hours ago so that's when I added this +example of your project so yeah I + + align:start position:0% +example of your project so yeah I + + + align:start position:0% +example of your project so yeah I +basically made changes and I kind of + + align:start position:0% +basically made changes and I kind of + + + align:start position:0% +basically made changes and I kind of +notated the change so yeah you can view + + align:start position:0% +notated the change so yeah you can view + + + align:start position:0% +notated the change so yeah you can view +like the whole history of stuff on + + align:start position:0% +like the whole history of stuff on + + + align:start position:0% +like the whole history of stuff on +there's also a ton of other features + + align:start position:0% +there's also a ton of other features + + + align:start position:0% +there's also a ton of other features +which we don't use you could submit bug + + align:start position:0% +which we don't use you could submit bug + + + align:start position:0% +which we don't use you could submit bug +reports under issues you can create a + + align:start position:0% +reports under issues you can create a + + + align:start position:0% +reports under issues you can create a +wiki for your project which most people + + align:start position:0% +wiki for your project which most people + + + align:start position:0% +wiki for your project which most people +do not do yeah so alright so the web + + align:start position:0% +do not do yeah so alright so the web + + + align:start position:0% +do not do yeah so alright so the web +interface is sort of you only really + + align:start position:0% +interface is sort of you only really + + + align:start position:0% +interface is sort of you only really +want to use it as a view of your files + + align:start position:0% +want to use it as a view of your files + + + align:start position:0% +want to use it as a view of your files +you don't actually upload files to there + + align:start position:0% +you don't actually upload files to there + + + align:start position:0% +you don't actually upload files to there +there is this upload button and create + + align:start position:0% +there is this upload button and create + + + align:start position:0% +there is this upload button and create +new file button but you don't want to + + align:start position:0% +new file button but you don't want to + + + align:start position:0% +new file button but you don't want to +use that so what we actually do want to + + align:start position:0% +use that so what we actually do want to + + + align:start position:0% +use that so what we actually do want to +use is this program called github + + align:start position:0% +use is this program called github + + + align:start position:0% +use is this program called github +Desktop github desktop it's sort of + + align:start position:0% +Desktop github desktop it's sort of + + + align:start position:0% +Desktop github desktop it's sort of +similar to Dropbox does anyone not heard + + align:start position:0% +similar to Dropbox does anyone not heard + + + align:start position:0% +similar to Dropbox does anyone not heard +of Dropbox has anyone heard of Dropbox + + align:start position:0% +of Dropbox has anyone heard of Dropbox + + + align:start position:0% +of Dropbox has anyone heard of Dropbox +yes yes yeah have an IPO it's a big + + align:start position:0% +yes yes yeah have an IPO it's a big + + + align:start position:0% +yes yes yeah have an IPO it's a big +company okay so Dropbox yeah here we go + + align:start position:0% +company okay so Dropbox yeah here we go + + + align:start position:0% +company okay so Dropbox yeah here we go +so Dropbox has a few things it has this + + align:start position:0% +so Dropbox has a few things it has this + + + align:start position:0% +so Dropbox has a few things it has this +like little program that runs + + align:start position:0% +like little program that runs + + + align:start position:0% +like little program that runs +continuously and what it does is it + + align:start position:0% +continuously and what it does is it + + + align:start position:0% +continuously and what it does is it +takes a folder on your hard disk and any + + align:start position:0% +takes a folder on your hard disk and any + + + align:start position:0% +takes a folder on your hard disk and any +file you put in it Dropbox will upload + + align:start position:0% +file you put in it Dropbox will upload + + + align:start position:0% +file you put in it Dropbox will upload +it to the cloud and if you have Dropbox + + align:start position:0% +it to the cloud and if you have Dropbox + + + align:start position:0% +it to the cloud and if you have Dropbox +on two computers it'll automatically + + align:start position:0% +on two computers it'll automatically + + + align:start position:0% +on two computers it'll automatically +sync them so you can have two folders + + align:start position:0% +sync them so you can have two folders + + + align:start position:0% +sync them so you can have two folders +look at the same + + align:start position:0% +look at the same + + + align:start position:0% +look at the same +github desktop is very similar to that + + align:start position:0% +github desktop is very similar to that + + + align:start position:0% +github desktop is very similar to that +except it does not do anything + + align:start position:0% +except it does not do anything + + + align:start position:0% +except it does not do anything +automatically if you drop files on the + + align:start position:0% +automatically if you drop files on the + + + align:start position:0% +automatically if you drop files on the +folder it will detect them but it won't + + align:start position:0% +folder it will detect them but it won't + + + align:start position:0% +folder it will detect them but it won't +automatically push them up to the cloud + + align:start position:0% +automatically push them up to the cloud + + + align:start position:0% +automatically push them up to the cloud +you have to do that manually the reason + + align:start position:0% +you have to do that manually the reason + + + align:start position:0% +you have to do that manually the reason +is what I said before is because you + + align:start position:0% +is what I said before is because you + + + align:start position:0% +is what I said before is because you +need to really make sure like this is a + + align:start position:0% +need to really make sure like this is a + + + align:start position:0% +need to really make sure like this is a +change that won't break the software so + + align:start position:0% +change that won't break the software so + + + align:start position:0% +change that won't break the software so +sort of forcing developers to write out + + align:start position:0% +sort of forcing developers to write out + + + align:start position:0% +sort of forcing developers to write out +the change yeah helps yeah helps make + + align:start position:0% +the change yeah helps yeah helps make + + + align:start position:0% +the change yeah helps yeah helps make +the software easier to maintain okay so + + align:start position:0% +the software easier to maintain okay so + + + align:start position:0% +the software easier to maintain okay so +so yeah in a moment yeah so I'll run + + align:start position:0% +so yeah in a moment yeah so I'll run + + + align:start position:0% +so yeah in a moment yeah so I'll run +through this quickly yeah so let me tell + + align:start position:0% +through this quickly yeah so let me tell + + + align:start position:0% +through this quickly yeah so let me tell +you all the steps that have to happen so + + align:start position:0% +you all the steps that have to happen so + + + align:start position:0% +you all the steps that have to happen so +in a moment on your own you will create + + align:start position:0% +in a moment on your own you will create + + + align:start position:0% +in a moment on your own you will create +an account on github.com so it's a free + + align:start position:0% +an account on github.com so it's a free + + + align:start position:0% +an account on github.com so it's a free +account you can use any email address + + align:start position:0% +account you can use any email address + + + align:start position:0% +account you can use any email address +you want you'll then download github + + align:start position:0% +you want you'll then download github + + + align:start position:0% +you want you'll then download github +desktop that is also free software + + align:start position:0% + + + + align:start position:0% + +right download github desktop so once + + align:start position:0% +right download github desktop so once + + + align:start position:0% +right download github desktop so once +you've done that you can log into github + + align:start position:0% +you've done that you can log into github + + + align:start position:0% +you've done that you can log into github +desktop and sync your cloud account with + + align:start position:0% +desktop and sync your cloud account with + + + align:start position:0% +desktop and sync your cloud account with +this piece of software locally once you + + align:start position:0% +this piece of software locally once you + + + align:start position:0% +this piece of software locally once you +log in you basically then choose which + + align:start position:0% +log in you basically then choose which + + + align:start position:0% +log in you basically then choose which +repositories you want to track and to do + + align:start position:0% +repositories you want to track and to do + + + align:start position:0% +repositories you want to track and to do +that we hit the plus button we say clone + + align:start position:0% + + + + align:start position:0% + +let me search for the repository we + + align:start position:0% +let me search for the repository we + + + align:start position:0% +let me search for the repository we +clone it we choose a location to save it + + align:start position:0% +clone it we choose a location to save it + + + align:start position:0% +clone it we choose a location to save it +so yea I'll run through this really + + align:start position:0% +so yea I'll run through this really + + + align:start position:0% +so yea I'll run through this really +quickly and then I'll step back so yeah + + align:start position:0% +quickly and then I'll step back so yeah + + + align:start position:0% +quickly and then I'll step back so yeah +so what it's doing a clone is basically + + align:start position:0% +so what it's doing a clone is basically + + + align:start position:0% +so what it's doing a clone is basically +making a copy of the repository so + + align:start position:0% +making a copy of the repository so + + + align:start position:0% +making a copy of the repository so +there's a version in the cloud at github + + align:start position:0% +there's a version in the cloud at github + + + align:start position:0% +there's a version in the cloud at github +in California I guess so we're + + align:start position:0% +in California I guess so we're + + + align:start position:0% +in California I guess so we're +downloading that so once we download it + + align:start position:0% +downloading that so once we download it + + + align:start position:0% +downloading that so once we download it +we could sort of see a very similar view + + align:start position:0% +we could sort of see a very similar view + + + align:start position:0% +we could sort of see a very similar view +to what we saw online + + align:start position:0% +to what we saw online + + + align:start position:0% +to what we saw online +so here link to electronic books and + + align:start position:0% +so here link to electronic books and + + + align:start position:0% +so here link to electronic books and +schedule that's the same thing we saw on + + align:start position:0% +schedule that's the same thing we saw on + + + align:start position:0% +schedule that's the same thing we saw on +the web page we also say no uncommitted + + align:start position:0% +the web page we also say no uncommitted + + + align:start position:0% +the web page we also say no uncommitted +changes great so yeah as I mentioned if + + align:start position:0% +changes great so yeah as I mentioned if + + + align:start position:0% +changes great so yeah as I mentioned if +you drop a file in the folder so github + + align:start position:0% +you drop a file in the folder so github + + + align:start position:0% +you drop a file in the folder so github +desktop is created this folder for me + + align:start position:0% +desktop is created this folder for me + + + align:start position:0% +desktop is created this folder for me +just like a normal folder and these are + + align:start position:0% +just like a normal folder and these are + + + align:start position:0% +just like a normal folder and these are +all the files in it so if we drag like a + + align:start position:0% +all the files in it so if we drag like a + + + align:start position:0% +all the files in it so if we drag like a +new file into it I'm just like with + + align:start position:0% +new file into it I'm just like with + + + align:start position:0% +new file into it I'm just like with +Dropbox so let's drag our final + + align:start position:0% +Dropbox so let's drag our final + + + align:start position:0% +Dropbox so let's drag our final +version of the NSA so yeah I dragged it + + align:start position:0% +version of the NSA so yeah I dragged it + + + align:start position:0% +version of the NSA so yeah I dragged it +into our repository folder locally on my + + align:start position:0% +into our repository folder locally on my + + + align:start position:0% +into our repository folder locally on my +hard drive if we switch back the github + + align:start position:0% +hard drive if we switch back the github + + + align:start position:0% +hard drive if we switch back the github +desktop its detected that change so then + + align:start position:0% +desktop its detected that change so then + + + align:start position:0% +desktop its detected that change so then +we want to commit so I said added my + + align:start position:0% +we want to commit so I said added my + + + align:start position:0% +we want to commit so I said added my +final si version so you always have to + + align:start position:0% +final si version so you always have to + + + align:start position:0% +final si version so you always have to +write out a commit message it won't let + + align:start position:0% +write out a commit message it won't let + + + align:start position:0% +write out a commit message it won't let +you commit a message + + align:start position:0% +you commit a message + + + align:start position:0% +you commit a message +so I said added final version I'll say + + align:start position:0% +so I said added final version I'll say + + + align:start position:0% +so I said added final version I'll say +commit so that actually commits it + + align:start position:0% +commit so that actually commits it + + + align:start position:0% +commit so that actually commits it +locally on your computer so it creates + + align:start position:0% +locally on your computer so it creates + + + align:start position:0% +locally on your computer so it creates +the whole history then we have to do + + align:start position:0% +the whole history then we have to do + + + align:start position:0% +the whole history then we have to do +another step to sync which syncs my + + align:start position:0% +another step to sync which syncs my + + + align:start position:0% +another step to sync which syncs my +history on my laptop with the universal + + align:start position:0% +history on my laptop with the universal + + + align:start position:0% +history on my laptop with the universal +history on github.com in California so + + align:start position:0% +history on github.com in California so + + + align:start position:0% +history on github.com in California so +once I hit sync we go back to the web + + align:start position:0% +once I hit sync we go back to the web + + + align:start position:0% +once I hit sync we go back to the web +page and reload it we can see the essay + + align:start position:0% +page and reload it we can see the essay + + + align:start position:0% +page and reload it we can see the essay +is appeared and we now have 566 minutes + + align:start position:0% +is appeared and we now have 566 minutes + + + align:start position:0% +is appeared and we now have 566 minutes +the last one enduringly committed a + + align:start position:0% +the last one enduringly committed a + + + align:start position:0% +the last one enduringly committed a +minute ago add my final essay version + + align:start position:0% + + + + align:start position:0% + +yeah so yeah that's basically the idea + + align:start position:0% +yeah so yeah that's basically the idea + + + align:start position:0% +yeah so yeah that's basically the idea +of the whole flow of files any questions \ No newline at end of file diff --git a/_ozQJncmJYk.txt b/_ozQJncmJYk.txt new file mode 100644 index 0000000000000000000000000000000000000000..6dadea86ccd31b3ac30e393e5d4ce3c4213311bb --- /dev/null +++ b/_ozQJncmJYk.txt @@ -0,0 +1,1323 @@ +align:start position:0% + +visualization is a crucial step for + + align:start position:0% +visualization is a crucial step for + + + align:start position:0% +visualization is a crucial step for +initial data exploration + + align:start position:0% +initial data exploration + + + align:start position:0% +initial data exploration +it helps us discern relationships + + align:start position:0% +it helps us discern relationships + + + align:start position:0% +it helps us discern relationships +patterns and outliers this video will + + align:start position:0% +patterns and outliers this video will + + + align:start position:0% +patterns and outliers this video will +give us a starting point on how to make + + align:start position:0% +give us a starting point on how to make + + + align:start position:0% +give us a starting point on how to make +plots and are but more advanced and way + + align:start position:0% +plots and are but more advanced and way + + + align:start position:0% +plots and are but more advanced and way +cooler visualization tips will be given + + align:start position:0% +cooler visualization tips will be given + + + align:start position:0% +cooler visualization tips will be given +in week 8 of this class let us first + + align:start position:0% +in week 8 of this class let us first + + + align:start position:0% +in week 8 of this class let us first +create a scatter plot with protein on + + align:start position:0% +create a scatter plot with protein on + + + align:start position:0% +create a scatter plot with protein on +the x-axis and fat on the y-axis to do + + align:start position:0% +the x-axis and fat on the y-axis to do + + + align:start position:0% +the x-axis and fat on the y-axis to do +this we can use the plot function in R + + align:start position:0% +this we can use the plot function in R + + + align:start position:0% +this we can use the plot function in R +and give it as a first input the protein + + align:start position:0% +and give it as a first input the protein + + + align:start position:0% +and give it as a first input the protein +factor on the x-axis and as a second + + align:start position:0% +factor on the x-axis and as a second + + + align:start position:0% +factor on the x-axis and as a second +input the total fat vector on the y axis + + align:start position:0% +input the total fat vector on the y axis + + + align:start position:0% +input the total fat vector on the y axis +and now pressing enter in new window + + align:start position:0% +and now pressing enter in new window + + + align:start position:0% +and now pressing enter in new window +pops up if you are on a PC the new + + align:start position:0% +pops up if you are on a PC the new + + + align:start position:0% +pops up if you are on a PC the new +window is gold our graphics and if you + + align:start position:0% +window is gold our graphics and if you + + + align:start position:0% +window is gold our graphics and if you +are on a Mac it is called quartz the + + align:start position:0% +are on a Mac it is called quartz the + + + align:start position:0% +are on a Mac it is called quartz the +plot has a very interesting triangular + + align:start position:0% +plot has a very interesting triangular + + + align:start position:0% +plot has a very interesting triangular +shape it looks like foods that are + + align:start position:0% +shape it looks like foods that are + + + align:start position:0% +shape it looks like foods that are +higher in protein are typically lower in + + align:start position:0% +higher in protein are typically lower in + + + align:start position:0% +higher in protein are typically lower in +fat and vice versa now looking at the + + align:start position:0% +fat and vice versa now looking at the + + + align:start position:0% +fat and vice versa now looking at the +aesthetics of the graph we realize that + + align:start position:0% +aesthetics of the graph we realize that + + + align:start position:0% +aesthetics of the graph we realize that +our gives default names for the x axis + + align:start position:0% +our gives default names for the x axis + + + align:start position:0% +our gives default names for the x axis +and the y axis using the vector dollar + + align:start position:0% +and the y axis using the vector dollar + + + align:start position:0% +and the y axis using the vector dollar +notation we can modify these labels by + + align:start position:0% +notation we can modify these labels by + + + align:start position:0% +notation we can modify these labels by +adding more arguments to the plot + + align:start position:0% +adding more arguments to the plot + + + align:start position:0% +adding more arguments to the plot +function to go back to the our console + + align:start position:0% +function to go back to the our console + + + align:start position:0% +function to go back to the our console +you can simply switch windows using the + + align:start position:0% +you can simply switch windows using the + + + align:start position:0% +you can simply switch windows using the +ctrl tab if you are on a Windows machine + + align:start position:0% +ctrl tab if you are on a Windows machine + + + align:start position:0% +ctrl tab if you are on a Windows machine +on a Mac the windows are not overlaid by + + align:start position:0% +on a Mac the windows are not overlaid by + + + align:start position:0% +on a Mac the windows are not overlaid by +default so accessing the console should + + align:start position:0% +default so accessing the console should + + + align:start position:0% +default so accessing the console should +be easy okay now let's use the up arrow + + align:start position:0% +be easy okay now let's use the up arrow + + + align:start position:0% +be easy okay now let's use the up arrow +to go back to our plot function and at + + align:start position:0% +to go back to our plot function and at + + + align:start position:0% +to go back to our plot function and at +the argument X lab equal protein and + + align:start position:0% +the argument X lab equal protein and + + + align:start position:0% +the argument X lab equal protein and +that gives us the label of the x axis + + align:start position:0% +that gives us the label of the x axis + + + align:start position:0% +that gives us the label of the x axis +then while AB equals fat and this gives + + align:start position:0% +then while AB equals fat and this gives + + + align:start position:0% +then while AB equals fat and this gives +us the label to the y axis and let's add + + align:start position:0% +us the label to the y axis and let's add + + + align:start position:0% +us the label to the y axis and let's add +a title to the plot using the argument + + align:start position:0% +a title to the plot using the argument + + + align:start position:0% +a title to the plot using the argument +main say the title is protein versus fat + + align:start position:0% +main say the title is protein versus fat + + + align:start position:0% +main say the title is protein versus fat +and let's change the color to red and + + align:start position:0% +and let's change the color to red and + + + align:start position:0% +and let's change the color to red and +remember to put quotation marks around + + align:start position:0% +remember to put quotation marks around + + + align:start position:0% +remember to put quotation marks around +the values of all these arguments and + + align:start position:0% +the values of all these arguments and + + + align:start position:0% +the values of all these arguments and +now pressing and turn going back to the + + align:start position:0% +now pressing and turn going back to the + + + align:start position:0% +now pressing and turn going back to the +graphics window we see that our made all + + align:start position:0% +graphics window we see that our made all + + + align:start position:0% +graphics window we see that our made all +the modifications we requested another + + align:start position:0% +the modifications we requested another + + + align:start position:0% +the modifications we requested another +way we can visualize our data is by + + align:start position:0% +way we can visualize our data is by + + + align:start position:0% +way we can visualize our data is by +plotting histogram + + align:start position:0% +plotting histogram + + + align:start position:0% +plotting histogram +we can do this using the histogram + + align:start position:0% +we can do this using the histogram + + + align:start position:0% +we can do this using the histogram +function in our but note that this + + align:start position:0% +function in our but note that this + + + align:start position:0% +function in our but note that this +function now only takes one variable as + + align:start position:0% +function now only takes one variable as + + + align:start position:0% +function now only takes one variable as +an input because the y-axis should have + + align:start position:0% +an input because the y-axis should have + + + align:start position:0% +an input because the y-axis should have +the frequencies so let's go back to our + + align:start position:0% +the frequencies so let's go back to our + + + align:start position:0% +the frequencies so let's go back to our +console and create a histogram of + + align:start position:0% +console and create a histogram of + + + align:start position:0% +console and create a histogram of +vitamin C for instance so we're gonna + + align:start position:0% +vitamin C for instance so we're gonna + + + align:start position:0% +vitamin C for instance so we're gonna +use the piston or histogram and then the + + align:start position:0% +use the piston or histogram and then the + + + align:start position:0% +use the piston or histogram and then the +argument that it takes is the vitamin C + + align:start position:0% +argument that it takes is the vitamin C + + + align:start position:0% +argument that it takes is the vitamin C +vector let's label the x-axis as vitamin + + align:start position:0% +vector let's label the x-axis as vitamin + + + align:start position:0% +vector let's label the x-axis as vitamin +C and this is given to us in milligrams + + align:start position:0% +C and this is given to us in milligrams + + + align:start position:0% +C and this is given to us in milligrams +and give it a title say histogram of + + align:start position:0% +and give it a title say histogram of + + + align:start position:0% +and give it a title say histogram of +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +vitamin C levels hmm + + align:start position:0% +vitamin C levels hmm + + + align:start position:0% +vitamin C levels hmm +even though the maximum vitamin C + + align:start position:0% +even though the maximum vitamin C + + + align:start position:0% +even though the maximum vitamin C +content is 2,000 milligrams most of our + + align:start position:0% +content is 2,000 milligrams most of our + + + align:start position:0% +content is 2,000 milligrams most of our +foods well to be more precise more than + + align:start position:0% +foods well to be more precise more than + + + align:start position:0% +foods well to be more precise more than +6,000 of them have less than 200 + + align:start position:0% +6,000 of them have less than 200 + + + align:start position:0% +6,000 of them have less than 200 +milligrams of vitamin C and the + + align:start position:0% +milligrams of vitamin C and the + + + align:start position:0% +milligrams of vitamin C and the +histogram lumps them all together in one + + align:start position:0% +histogram lumps them all together in one + + + align:start position:0% +histogram lumps them all together in one +cell well it would be nice if we can + + align:start position:0% +cell well it would be nice if we can + + + align:start position:0% +cell well it would be nice if we can +zoom into this section here and get a + + align:start position:0% +zoom into this section here and get a + + + align:start position:0% +zoom into this section here and get a +finer understanding of the data to do + + align:start position:0% +finer understanding of the data to do + + + align:start position:0% +finer understanding of the data to do +this we need to limit the x-axis to go + + align:start position:0% +this we need to limit the x-axis to go + + + align:start position:0% +this we need to limit the x-axis to go +from zero to say 100 milligrams so let's + + align:start position:0% +from zero to say 100 milligrams so let's + + + align:start position:0% +from zero to say 100 milligrams so let's +go back to the console and then we're + + align:start position:0% +go back to the console and then we're + + + align:start position:0% +go back to the console and then we're +going to add the argument x lim to limit + + align:start position:0% +going to add the argument x lim to limit + + + align:start position:0% +going to add the argument x lim to limit +the x-axis and using the combined + + align:start position:0% +the x-axis and using the combined + + + align:start position:0% +the x-axis and using the combined +function or the c function we're gonna + + align:start position:0% +function or the c function we're gonna + + + align:start position:0% +function or the c function we're gonna +set the first input to be 0 which is the + + align:start position:0% +set the first input to be 0 which is the + + + align:start position:0% +set the first input to be 0 which is the +lowest value that we want to see on the + + align:start position:0% +lowest value that we want to see on the + + + align:start position:0% +lowest value that we want to see on the +x-axis and the second argument is being + + align:start position:0% +x-axis and the second argument is being + + + align:start position:0% +x-axis and the second argument is being +100 which is the highest value that we + + align:start position:0% +100 which is the highest value that we + + + align:start position:0% +100 which is the highest value that we +want to see on the x-axis and now + + align:start position:0% +want to see on the x-axis and now + + + align:start position:0% +want to see on the x-axis and now +pressing enter and we can see that our + + align:start position:0% +pressing enter and we can see that our + + + align:start position:0% +pressing enter and we can see that our +gives us 0 to 100 on the x-axis but we + + align:start position:0% +gives us 0 to 100 on the x-axis but we + + + align:start position:0% +gives us 0 to 100 on the x-axis but we +only see this one big cell it's use that + + align:start position:0% +only see this one big cell it's use that + + + align:start position:0% +only see this one big cell it's use that +are only zoomed into the area but it + + align:start position:0% +are only zoomed into the area but it + + + align:start position:0% +are only zoomed into the area but it +didn't break that huge cell and this + + align:start position:0% +didn't break that huge cell and this + + + align:start position:0% +didn't break that huge cell and this +doesn't give us any additional + + align:start position:0% +doesn't give us any additional + + + align:start position:0% +doesn't give us any additional +information so we really need to break + + align:start position:0% +information so we really need to break + + + align:start position:0% +information so we really need to break +up this cell into smaller pieces and say + + align:start position:0% +up this cell into smaller pieces and say + + + align:start position:0% +up this cell into smaller pieces and say +we want 100 cells and since the interval + + align:start position:0% +we want 100 cells and since the interval + + + align:start position:0% +we want 100 cells and since the interval +goes from 0 to 100 then we would expect + + align:start position:0% +goes from 0 to 100 then we would expect + + + align:start position:0% +goes from 0 to 100 then we would expect +our to create divisions that are 1 + + align:start position:0% +our to create divisions that are 1 + + + align:start position:0% +our to create divisions that are 1 +milligrams in length so let's do this + + align:start position:0% +milligrams in length so let's do this + + + align:start position:0% +milligrams in length so let's do this +let's go back to the console and then + + align:start position:0% +let's go back to the console and then + + + align:start position:0% +let's go back to the console and then +we're going to add the argument + + align:start position:0% +we're going to add the argument + + + align:start position:0% +we're going to add the argument +rakes equals 100 and this sets the + + align:start position:0% +rakes equals 100 and this sets the + + + align:start position:0% +rakes equals 100 and this sets the +number of cells that we want to see to + + align:start position:0% +number of cells that we want to see to + + + align:start position:0% +number of cells that we want to see to +100 so let's see oh we actually only see + + align:start position:0% +100 so let's see oh we actually only see + + + align:start position:0% +100 so let's see oh we actually only see +5 cells and each cell is 20 milligrams + + align:start position:0% +5 cells and each cell is 20 milligrams + + + align:start position:0% +5 cells and each cell is 20 milligrams +long + + align:start position:0% +long + + + align:start position:0% +long +well what happened we were expecting 100 + + align:start position:0% +well what happened we were expecting 100 + + + align:start position:0% +well what happened we were expecting 100 +cells I'll remember that the histogram + + align:start position:0% +cells I'll remember that the histogram + + + align:start position:0% +cells I'll remember that the histogram +originally went far beyond 100 + + align:start position:0% +originally went far beyond 100 + + + align:start position:0% +originally went far beyond 100 +milligrams the maximum was 2,000 + + align:start position:0% +milligrams the maximum was 2,000 + + + align:start position:0% +milligrams the maximum was 2,000 +milligrams and now if we were to divide + + align:start position:0% +milligrams and now if we were to divide + + + align:start position:0% +milligrams and now if we were to divide +the original interval from zero to 2,000 + + align:start position:0% +the original interval from zero to 2,000 + + + align:start position:0% +the original interval from zero to 2,000 +into 100 cells then 2,000 divided by 100 + + align:start position:0% +into 100 cells then 2,000 divided by 100 + + + align:start position:0% +into 100 cells then 2,000 divided by 100 +each cell would be 20 milligrams long + + align:start position:0% +each cell would be 20 milligrams long + + + align:start position:0% +each cell would be 20 milligrams long +and this is exactly what our did it + + align:start position:0% +and this is exactly what our did it + + + align:start position:0% +and this is exactly what our did it +actually divided all the spectrum of + + align:start position:0% +actually divided all the spectrum of + + + align:start position:0% +actually divided all the spectrum of +values from 0 to 2000 into 100 cells and + + align:start position:0% +values from 0 to 2000 into 100 cells and + + + align:start position:0% +values from 0 to 2000 into 100 cells and +not only the spectrum from 0 to 100 but + + align:start position:0% +not only the spectrum from 0 to 100 but + + + align:start position:0% +not only the spectrum from 0 to 100 but +we still want to divide the interval 0 + + align:start position:0% +we still want to divide the interval 0 + + + align:start position:0% +we still want to divide the interval 0 +to 100 into 100 cells each of length one + + align:start position:0% +to 100 into 100 cells each of length one + + + align:start position:0% +to 100 into 100 cells each of length one +milligram and how can we do this well we + + align:start position:0% +milligram and how can we do this well we + + + align:start position:0% +milligram and how can we do this well we +simply need to think in terms of the + + align:start position:0% +simply need to think in terms of the + + + align:start position:0% +simply need to think in terms of the +original interval which was 0 to 2000 + + align:start position:0% +original interval which was 0 to 2000 + + + align:start position:0% +original interval which was 0 to 2000 +and if we were to break it into two + + align:start position:0% +and if we were to break it into two + + + align:start position:0% +and if we were to break it into two +thousand cells then each one will be of + + align:start position:0% +thousand cells then each one will be of + + + align:start position:0% +thousand cells then each one will be of +length 1 milligram so now we know that + + align:start position:0% +length 1 milligram so now we know that + + + align:start position:0% +length 1 milligram so now we know that +actually we needed to set the brakes to + + align:start position:0% +actually we needed to set the brakes to + + + align:start position:0% +actually we needed to set the brakes to +2,000 so let's do this and now we obtain + + align:start position:0% +2,000 so let's do this and now we obtain + + + align:start position:0% +2,000 so let's do this and now we obtain +our refined histogram and we see new + + align:start position:0% +our refined histogram and we see new + + + align:start position:0% +our refined histogram and we see new +information here come up remember our + + align:start position:0% +information here come up remember our + + + align:start position:0% +information here come up remember our +initial conclusion was that more than + + align:start position:0% +initial conclusion was that more than + + + align:start position:0% +initial conclusion was that more than +6000 foods have less than 200 milligrams + + align:start position:0% +6000 foods have less than 200 milligrams + + + align:start position:0% +6000 foods have less than 200 milligrams +of vitamin C but now that we refined our + + align:start position:0% +of vitamin C but now that we refined our + + + align:start position:0% +of vitamin C but now that we refined our +graph we obtained an additional level of + + align:start position:0% +graph we obtained an additional level of + + + align:start position:0% +graph we obtained an additional level of +information actually more than 5000 of + + align:start position:0% +information actually more than 5000 of + + + align:start position:0% +information actually more than 5000 of +them have less than 1 milligrams of + + align:start position:0% +them have less than 1 milligrams of + + + align:start position:0% +them have less than 1 milligrams of +vitamin C now a third way we can + + align:start position:0% +vitamin C now a third way we can + + + align:start position:0% +vitamin C now a third way we can +visualize the data is using box plots so + + align:start position:0% +visualize the data is using box plots so + + + align:start position:0% +visualize the data is using box plots so +let's go back to the console and create + + align:start position:0% +let's go back to the console and create + + + align:start position:0% +let's go back to the console and create +a box plot for sugar so the function + + align:start position:0% +a box plot for sugar so the function + + + align:start position:0% +a box plot for sugar so the function +we're going to be using is simply box + + align:start position:0% +we're going to be using is simply box + + + align:start position:0% +we're going to be using is simply box +plot and similarly to the histogram + + align:start position:0% +plot and similarly to the histogram + + + align:start position:0% +plot and similarly to the histogram +function the box plot function only + + align:start position:0% +function the box plot function only + + + align:start position:0% +function the box plot function only +takes as an input a single vector and in + + align:start position:0% +takes as an input a single vector and in + + + align:start position:0% +takes as an input a single vector and in +this case it would be the sugar vector + + align:start position:0% +this case it would be the sugar vector + + + align:start position:0% +this case it would be the sugar vector +and let's create a title that says box + + align:start position:0% +and let's create a title that says box + + + align:start position:0% +and let's create a title that says box +plot of sugar levels + + align:start position:0% +plot of sugar levels + + + align:start position:0% +plot of sugar levels +and is it the y-axis or the x-axis that + + align:start position:0% +and is it the y-axis or the x-axis that + + + align:start position:0% +and is it the y-axis or the x-axis that +we have to label it as you know the + + align:start position:0% +we have to label it as you know the + + + align:start position:0% +we have to label it as you know the +sugar level so if we're not so sure + + align:start position:0% +sugar level so if we're not so sure + + + align:start position:0% +sugar level so if we're not so sure +let's just plot it and oh this should be + + align:start position:0% +let's just plot it and oh this should be + + + align:start position:0% +let's just plot it and oh this should be +the y-axis so let's go back to the + + align:start position:0% +the y-axis so let's go back to the + + + align:start position:0% +the y-axis so let's go back to the +console and simply set the y label to be + + align:start position:0% +console and simply set the y label to be + + + align:start position:0% +console and simply set the y label to be +sugar in grams and now we have our box + + align:start position:0% +sugar in grams and now we have our box + + + align:start position:0% +sugar in grams and now we have our box +plot with the right labels what is it + + align:start position:0% +plot with the right labels what is it + + + align:start position:0% +plot with the right labels what is it +trying to tell us here it looks a little + + align:start position:0% +trying to tell us here it looks a little + + + align:start position:0% +trying to tell us here it looks a little +bit strange well the average of sugar + + align:start position:0% +bit strange well the average of sugar + + + align:start position:0% +bit strange well the average of sugar +across the data set seems to be pretty + + align:start position:0% +across the data set seems to be pretty + + + align:start position:0% +across the data set seems to be pretty +low it's somewhere around five grams but + + align:start position:0% +low it's somewhere around five grams but + + + align:start position:0% +low it's somewhere around five grams but +we have a lot of outliers with extremely + + align:start position:0% +we have a lot of outliers with extremely + + + align:start position:0% +we have a lot of outliers with extremely +high values of sugar there exist some + + align:start position:0% +high values of sugar there exist some + + + align:start position:0% +high values of sugar there exist some +foods that have almost 100 grams of + + align:start position:0% +foods that have almost 100 grams of + + + align:start position:0% +foods that have almost 100 grams of +sugar in 100 grams while candies are + + align:start position:0% +sugar in 100 grams while candies are + + + align:start position:0% +sugar in 100 grams while candies are +definitely among these foods so we just + + align:start position:0% +definitely among these foods so we just + + + align:start position:0% +definitely among these foods so we just +reviewed three ways in which we can + + align:start position:0% +reviewed three ways in which we can + + + align:start position:0% +reviewed three ways in which we can +visualize our data in week eight we will + + align:start position:0% +visualize our data in week eight we will + + + align:start position:0% +visualize our data in week eight we will +see more advanced visualization tools to + + align:start position:0% +see more advanced visualization tools to + + + align:start position:0% +see more advanced visualization tools to +make more informative plots in our next + + align:start position:0% +make more informative plots in our next + + + align:start position:0% +make more informative plots in our next +video we will see how we can construct + + align:start position:0% +video we will see how we can construct + + + align:start position:0% +video we will see how we can construct +and add new variables to our data set + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/a2xqcqRYosg.txt b/a2xqcqRYosg.txt new file mode 100644 index 0000000000000000000000000000000000000000..a8f2d3e4d0333084dffd25057e26e17d0f9b388b --- /dev/null +++ b/a2xqcqRYosg.txt @@ -0,0 +1,1163 @@ +align:start position:0% + +materials are often classified as + + align:start position:0% +materials are often classified as + + + align:start position:0% +materials are often classified as +crystalline semi crystalline or + + align:start position:0% +crystalline semi crystalline or + + + align:start position:0% +crystalline semi crystalline or +amorphous most polymers are semi + + align:start position:0% +amorphous most polymers are semi + + + align:start position:0% +amorphous most polymers are semi +crystalline this means a fraction the + + align:start position:0% +crystalline this means a fraction the + + + align:start position:0% +crystalline this means a fraction the +material is amorphous and lacks order in + + align:start position:0% +material is amorphous and lacks order in + + + align:start position:0% +material is amorphous and lacks order in +arrangements of polymer chains while the + + align:start position:0% +arrangements of polymer chains while the + + + align:start position:0% +arrangements of polymer chains while the +remainder of the material exhibits + + align:start position:0% +remainder of the material exhibits + + + align:start position:0% +remainder of the material exhibits +parallel well ordered chains that define + + align:start position:0% +parallel well ordered chains that define + + + align:start position:0% +parallel well ordered chains that define +crystalline regions there are several + + align:start position:0% +crystalline regions there are several + + + align:start position:0% +crystalline regions there are several +methods for determining the degree of + + align:start position:0% +methods for determining the degree of + + + align:start position:0% +methods for determining the degree of +crystallinity and power x-ray + + align:start position:0% +crystallinity and power x-ray + + + align:start position:0% +crystallinity and power x-ray +diffraction can be used to determine + + align:start position:0% +diffraction can be used to determine + + + align:start position:0% +diffraction can be used to determine +degree of crystallinity because + + align:start position:0% +degree of crystallinity because + + + align:start position:0% +degree of crystallinity because +intensity of x-ray diffraction + + align:start position:0% +intensity of x-ray diffraction + + + align:start position:0% +intensity of x-ray diffraction +reflection is proportional to the + + align:start position:0% +reflection is proportional to the + + + align:start position:0% +reflection is proportional to the +material density an x-ray diffraction + + align:start position:0% +material density an x-ray diffraction + + + align:start position:0% +material density an x-ray diffraction +pattern displays both sharp Bragg's + + align:start position:0% +pattern displays both sharp Bragg's + + + align:start position:0% +pattern displays both sharp Bragg's +Peaks arising from the crystalline + + align:start position:0% +Peaks arising from the crystalline + + + align:start position:0% +Peaks arising from the crystalline +portion and a broad diffraction peak + + align:start position:0% +portion and a broad diffraction peak + + + align:start position:0% +portion and a broad diffraction peak +caused by scattering from the amorphous + + align:start position:0% +caused by scattering from the amorphous + + + align:start position:0% +caused by scattering from the amorphous +portion of the polymer the degree of + + align:start position:0% +portion of the polymer the degree of + + + align:start position:0% +portion of the polymer the degree of +crystallinity can be determined using + + align:start position:0% +crystallinity can be determined using + + + align:start position:0% +crystallinity can be determined using +this formula with the total integrated + + align:start position:0% +this formula with the total integrated + + + align:start position:0% +this formula with the total integrated +intensities all of the sharp Peaks are + + align:start position:0% +intensities all of the sharp Peaks are + + + align:start position:0% +intensities all of the sharp Peaks are +divided by the integrated intensities of + + align:start position:0% +divided by the integrated intensities of + + + align:start position:0% +divided by the integrated intensities of +all peaks including that of the + + align:start position:0% +all peaks including that of the + + + align:start position:0% +all peaks including that of the +amorphous peak many laboratories have + + align:start position:0% +amorphous peak many laboratories have + + + align:start position:0% +amorphous peak many laboratories have +access to XR d peak fitting software + + align:start position:0% +access to XR d peak fitting software + + + align:start position:0% +access to XR d peak fitting software +that can be used to calculate degree of + + align:start position:0% +that can be used to calculate degree of + + + align:start position:0% +that can be used to calculate degree of +crystallinity but this software can + + align:start position:0% +crystallinity but this software can + + + align:start position:0% +crystallinity but this software can +often be expensive I set out to create a + + align:start position:0% +often be expensive I set out to create a + + + align:start position:0% +often be expensive I set out to create a +peak fitting software to calculate + + align:start position:0% +peak fitting software to calculate + + + align:start position:0% +peak fitting software to calculate +degree of crystallinity for semi + + align:start position:0% +degree of crystallinity for semi + + + align:start position:0% +degree of crystallinity for semi +crystalline polymers using Mathematica + + align:start position:0% +crystalline polymers using Mathematica + + + align:start position:0% +crystalline polymers using Mathematica +the basic idea for this program is that + + align:start position:0% +the basic idea for this program is that + + + align:start position:0% +the basic idea for this program is that +the user will define a series of + + align:start position:0% +the user will define a series of + + + align:start position:0% +the user will define a series of +Gaussian Peaks using this equation the + + align:start position:0% +Gaussian Peaks using this equation the + + + align:start position:0% +Gaussian Peaks using this equation the +width the height and the exposition of + + align:start position:0% +width the height and the exposition of + + + align:start position:0% +width the height and the exposition of +these Peaks can be manipulated this code + + align:start position:0% +these Peaks can be manipulated this code + + + align:start position:0% +these Peaks can be manipulated this code +allows the user to adjust the appearance + + align:start position:0% +allows the user to adjust the appearance + + + align:start position:0% +allows the user to adjust the appearance +and position of multiple peaks and match + + align:start position:0% +and position of multiple peaks and match + + + align:start position:0% +and position of multiple peaks and match +it to an existing XRD pattern first the + + align:start position:0% +it to an existing XRD pattern first the + + + align:start position:0% +it to an existing XRD pattern first the +code allows the user to adjust the + + align:start position:0% +code allows the user to adjust the + + + align:start position:0% +code allows the user to adjust the +position and the scale of the XRD + + align:start position:0% +position and the scale of the XRD + + + align:start position:0% +position and the scale of the XRD +pattern the user is then able to adjust + + align:start position:0% +pattern the user is then able to adjust + + + align:start position:0% +pattern the user is then able to adjust +the positions of both the crystalline + + align:start position:0% +the positions of both the crystalline + + + align:start position:0% +the positions of both the crystalline +peaks and amorphous Peaks + + align:start position:0% + + + + align:start position:0% + +once the user obtains a fit that they're + + align:start position:0% +once the user obtains a fit that they're + + + align:start position:0% +once the user obtains a fit that they're +happy with they can calculate the degree + + align:start position:0% +happy with they can calculate the degree + + + align:start position:0% +happy with they can calculate the degree +of crystallinity by determining the + + align:start position:0% +of crystallinity by determining the + + + align:start position:0% +of crystallinity by determining the +integrated area under the crystalline + + align:start position:0% +integrated area under the crystalline + + + align:start position:0% +integrated area under the crystalline +Peaks divided by the integrated area + + align:start position:0% +Peaks divided by the integrated area + + + align:start position:0% +Peaks divided by the integrated area +under all of the peaks in this + + align:start position:0% +under all of the peaks in this + + + align:start position:0% +under all of the peaks in this +particular polymer the determined degree + + align:start position:0% +particular polymer the determined degree + + + align:start position:0% +particular polymer the determined degree +of crystallinity was 41% to test the + + align:start position:0% +of crystallinity was 41% to test the + + + align:start position:0% +of crystallinity was 41% to test the +accuracy of my code I fit xid patterns + + align:start position:0% +accuracy of my code I fit xid patterns + + + align:start position:0% +accuracy of my code I fit xid patterns +for polyethylene varieties with knowing + + align:start position:0% +for polyethylene varieties with knowing + + + align:start position:0% +for polyethylene varieties with knowing +values for degree of crystallinity the + + align:start position:0% +values for degree of crystallinity the + + + align:start position:0% +values for degree of crystallinity the +polymers for which I chose to match our + + align:start position:0% +polymers for which I chose to match our + + + align:start position:0% +polymers for which I chose to match our +Sardi patterns were low-density + + align:start position:0% +Sardi patterns were low-density + + + align:start position:0% +Sardi patterns were low-density +polyethylene high-density polyethylene + + align:start position:0% +polyethylene high-density polyethylene + + + align:start position:0% +polyethylene high-density polyethylene +and ultra high molecular weight + + align:start position:0% +and ultra high molecular weight + + + align:start position:0% +and ultra high molecular weight +polyethylene the expected value for + + align:start position:0% +polyethylene the expected value for + + + align:start position:0% +polyethylene the expected value for +degree of crystallinity for low-density + + align:start position:0% +degree of crystallinity for low-density + + + align:start position:0% +degree of crystallinity for low-density +polyethylene is 44 to 51 percent + + align:start position:0% +polyethylene is 44 to 51 percent + + + align:start position:0% +polyethylene is 44 to 51 percent +crystallinity the value obtained using + + align:start position:0% +crystallinity the value obtained using + + + align:start position:0% +crystallinity the value obtained using +Mathematica peak fitting was 46% + + align:start position:0% +Mathematica peak fitting was 46% + + + align:start position:0% +Mathematica peak fitting was 46% +crystallinity so this is within the + + align:start position:0% +crystallinity so this is within the + + + align:start position:0% +crystallinity so this is within the +accepted range similarly the expected + + align:start position:0% +accepted range similarly the expected + + + align:start position:0% +accepted range similarly the expected +value for degree of crystallinity for + + align:start position:0% +value for degree of crystallinity for + + + align:start position:0% +value for degree of crystallinity for +high-density polyethylene is 48 to 69 + + align:start position:0% +high-density polyethylene is 48 to 69 + + + align:start position:0% +high-density polyethylene is 48 to 69 +percent crystallinity and Mathematica + + align:start position:0% +percent crystallinity and Mathematica + + + align:start position:0% +percent crystallinity and Mathematica +peak fitting obtained a value of 56% + + align:start position:0% +peak fitting obtained a value of 56% + + + align:start position:0% +peak fitting obtained a value of 56% +crystallinity finally ultra high + + align:start position:0% +crystallinity finally ultra high + + + align:start position:0% +crystallinity finally ultra high +molecular weight polyethylene has an + + align:start position:0% +molecular weight polyethylene has an + + + align:start position:0% +molecular weight polyethylene has an +expected value of 75 to 77 percent + + align:start position:0% +expected value of 75 to 77 percent + + + align:start position:0% +expected value of 75 to 77 percent +crystallinity Mathematica peak fitting + + align:start position:0% +crystallinity Mathematica peak fitting + + + align:start position:0% +crystallinity Mathematica peak fitting +showed a value of 76 percent + + align:start position:0% +showed a value of 76 percent + + + align:start position:0% +showed a value of 76 percent +crystallinity in all three polymer case + + align:start position:0% +crystallinity in all three polymer case + + + align:start position:0% +crystallinity in all three polymer case +studies this code obtained a degree of + + align:start position:0% +studies this code obtained a degree of + + + align:start position:0% +studies this code obtained a degree of +crystallinity value within the + + align:start position:0% +crystallinity value within the + + + align:start position:0% +crystallinity value within the +acceptable range indicating manual + + align:start position:0% +acceptable range indicating manual + + + align:start position:0% +acceptable range indicating manual +mathematical peak fitting of x heidi + + align:start position:0% +mathematical peak fitting of x heidi + + + align:start position:0% +mathematical peak fitting of x heidi +plots is a reasonable way to determine a + + align:start position:0% +plots is a reasonable way to determine a + + + align:start position:0% +plots is a reasonable way to determine a +materials degree of crystallinity the + + align:start position:0% +materials degree of crystallinity the + + + align:start position:0% +materials degree of crystallinity the +code I just described showed a way to + + align:start position:0% +code I just described showed a way to + + + align:start position:0% +code I just described showed a way to +important an exciting pattern as an + + align:start position:0% +important an exciting pattern as an + + + align:start position:0% +important an exciting pattern as an +image and manually fit the peaks to + + align:start position:0% +image and manually fit the peaks to + + + align:start position:0% +image and manually fit the peaks to +calculate degree of crystallinity hover + + align:start position:0% +calculate degree of crystallinity hover + + + align:start position:0% +calculate degree of crystallinity hover +I can do a better job of determining + + align:start position:0% +I can do a better job of determining + + + align:start position:0% +I can do a better job of determining +degree of crystallinity if I let the + + align:start position:0% +degree of crystallinity if I let the + + + align:start position:0% +degree of crystallinity if I let the +users peak selections be a starting gas + + align:start position:0% +users peak selections be a starting gas + + + align:start position:0% +users peak selections be a starting gas +and let Mathematica find the best set of + + align:start position:0% +and let Mathematica find the best set of + + + align:start position:0% +and let Mathematica find the best set of +Gaussian curves to fit the data one of + + align:start position:0% +Gaussian curves to fit the data one of + + + align:start position:0% +Gaussian curves to fit the data one of +the challenges with this method is I + + align:start position:0% +the challenges with this method is I + + + align:start position:0% +the challenges with this method is I +have to take data that's currently saved + + align:start position:0% +have to take data that's currently saved + + + align:start position:0% +have to take data that's currently saved +as a JPEG image and convert it into + + align:start position:0% +as a JPEG image and convert it into + + + align:start position:0% +as a JPEG image and convert it into +something at matok I can use to find the + + align:start position:0% +something at matok I can use to find the + + + align:start position:0% +something at matok I can use to find the +best fit so the way I do this is I + + align:start position:0% +best fit so the way I do this is I + + + align:start position:0% +best fit so the way I do this is I +import my JPEG image here and then I use + + align:start position:0% +import my JPEG image here and then I use + + + align:start position:0% +import my JPEG image here and then I use +that and I convert it to be either black + + align:start position:0% +that and I convert it to be either black + + + align:start position:0% +that and I convert it to be either black +or white then I'm able to determine the + + align:start position:0% +or white then I'm able to determine the + + + align:start position:0% +or white then I'm able to determine the +locations of the black pixels and + + align:start position:0% +locations of the black pixels and + + + align:start position:0% +locations of the black pixels and +isolate them however my line is really + + align:start position:0% +isolate them however my line is really + + + align:start position:0% +isolate them however my line is really +thick which means that at each X + + align:start position:0% +thick which means that at each X + + + align:start position:0% +thick which means that at each X +position I have multiple Y positions so + + align:start position:0% +position I have multiple Y positions so + + + align:start position:0% +position I have multiple Y positions so +that I'm able to use the following code + + align:start position:0% +that I'm able to use the following code + + + align:start position:0% +that I'm able to use the following code +to choose whether I want to have the + + align:start position:0% +to choose whether I want to have the + + + align:start position:0% +to choose whether I want to have the +mean Y position at each x value or one + + align:start position:0% +mean Y position at each x value or one + + + align:start position:0% +mean Y position at each x value or one +of the highest Y positions of each x + + align:start position:0% +of the highest Y positions of each x + + + align:start position:0% +of the highest Y positions of each x +value after my data is in this form I'm + + align:start position:0% +value after my data is in this form I'm + + + align:start position:0% +value after my data is in this form I'm +able to use it for future curve fitting + + align:start position:0% +able to use it for future curve fitting + + + align:start position:0% +able to use it for future curve fitting +applications so after I have data I'm + + align:start position:0% +applications so after I have data I'm + + + align:start position:0% +applications so after I have data I'm +able to write code that allows the user + + align:start position:0% +able to write code that allows the user + + + align:start position:0% +able to write code that allows the user +to input guesses for where they think + + align:start position:0% +to input guesses for where they think + + + align:start position:0% +to input guesses for where they think +the peaks should be located and then + + align:start position:0% +the peaks should be located and then + + + align:start position:0% +the peaks should be located and then +Mathematica uses a function called find + + align:start position:0% +Mathematica uses a function called find + + + align:start position:0% +Mathematica uses a function called find +fit that's going to find the best + + align:start position:0% +fit that's going to find the best + + + align:start position:0% +fit that's going to find the best +approximation for my data given the + + align:start position:0% +approximation for my data given the + + + align:start position:0% +approximation for my data given the +guesses and the model I give it to work + + align:start position:0% +guesses and the model I give it to work + + + align:start position:0% +guesses and the model I give it to work +with so this model is a model that + + align:start position:0% +with so this model is a model that + + + align:start position:0% +with so this model is a model that +includes three different Gaussian Peaks + + align:start position:0% +includes three different Gaussian Peaks + + + align:start position:0% +includes three different Gaussian Peaks +so the full code is available to you in + + align:start position:0% +so the full code is available to you in + + + align:start position:0% +so the full code is available to you in +my notebook but here's the final product + + align:start position:0% +my notebook but here's the final product + + + align:start position:0% +my notebook but here's the final product +like in the previous curve fitting + + align:start position:0% +like in the previous curve fitting + + + align:start position:0% +like in the previous curve fitting +program I showed you you're able to + + align:start position:0% +program I showed you you're able to + + + align:start position:0% +program I showed you you're able to +adjust the positions and shapes of the + + align:start position:0% +adjust the positions and shapes of the + + + align:start position:0% +adjust the positions and shapes of the +crystalline peaks and the amorphous + + align:start position:0% +crystalline peaks and the amorphous + + + align:start position:0% +crystalline peaks and the amorphous +peaks as follows once you think you have + + align:start position:0% +peaks as follows once you think you have + + + align:start position:0% +peaks as follows once you think you have +a fit that's fairly reasonable you can + + align:start position:0% +a fit that's fairly reasonable you can + + + align:start position:0% +a fit that's fairly reasonable you can +click find your solution and mathematic + + align:start position:0% +click find your solution and mathematic + + + align:start position:0% +click find your solution and mathematic +is going to help you find the best fit + + align:start position:0% +is going to help you find the best fit + + + align:start position:0% +is going to help you find the best fit +for this data then using these + + align:start position:0% +for this data then using these + + + align:start position:0% +for this data then using these +Mathematica found values you can + + align:start position:0% +Mathematica found values you can + + + align:start position:0% +Mathematica found values you can +calculate degree of crystallinity for + + align:start position:0% +calculate degree of crystallinity for + + + align:start position:0% +calculate degree of crystallinity for +the curve + + align:start position:0% +the curve + + + align:start position:0% +the curve +so in conclusion degree of crystallinity + + align:start position:0% +so in conclusion degree of crystallinity + + + align:start position:0% +so in conclusion degree of crystallinity +can be determined from XRD patterns and + + align:start position:0% +can be determined from XRD patterns and + + + align:start position:0% +can be determined from XRD patterns and +today I demonstrated two possible ways + + align:start position:0% +today I demonstrated two possible ways + + + align:start position:0% +today I demonstrated two possible ways +of doing this in Mathematica there's a + + align:start position:0% +of doing this in Mathematica there's a + + + align:start position:0% +of doing this in Mathematica there's a +fair amount of background code that goes + + align:start position:0% +fair amount of background code that goes + + + align:start position:0% +fair amount of background code that goes +into the outputs you saw today and all + + align:start position:0% +into the outputs you saw today and all + + + align:start position:0% +into the outputs you saw today and all +this code is available to you in my + + align:start position:0% +this code is available to you in my + + + align:start position:0% +this code is available to you in my +Mathematica notebook hopefully you'll + + align:start position:0% +Mathematica notebook hopefully you'll + + + align:start position:0% +Mathematica notebook hopefully you'll +find it very easy to modify to meet your + + align:start position:0% +find it very easy to modify to meet your + + + align:start position:0% +find it very easy to modify to meet your +unique application needs \ No newline at end of file diff --git a/akNw8CEHC_c.txt b/akNw8CEHC_c.txt new file mode 100644 index 0000000000000000000000000000000000000000..c41c4c513948778f3bff2cdf5bb02278b5b1c0ba --- /dev/null +++ b/akNw8CEHC_c.txt @@ -0,0 +1,1907 @@ +align:start position:0% + +here we have a spreadsheet and + + align:start position:0% +here we have a spreadsheet and + + + align:start position:0% +here we have a spreadsheet and +LibreOffice that contains all of our + + align:start position:0% +LibreOffice that contains all of our + + + align:start position:0% +LibreOffice that contains all of our +data up here we have the basic data + + align:start position:0% +data up here we have the basic data + + + align:start position:0% +data up here we have the basic data +which are the price per click and click + + align:start position:0% +which are the price per click and click + + + align:start position:0% +which are the price per click and click +through rate below we have the average + + align:start position:0% +through rate below we have the average + + + align:start position:0% +through rate below we have the average +price per display which will actually be + + align:start position:0% +price per display which will actually be + + + align:start position:0% +price per display which will actually be +using below it we have the budgets and + + align:start position:0% +using below it we have the budgets and + + + align:start position:0% +using below it we have the budgets and +below that we have the query estimates + + align:start position:0% +below that we have the query estimates + + + align:start position:0% +below that we have the query estimates +after the data we then have the + + align:start position:0% +after the data we then have the + + + align:start position:0% +after the data we then have the +variables so these are the XA ones + + align:start position:0% +variables so these are the XA ones + + + align:start position:0% +variables so these are the XA ones +through XA 3s the XT ones through XT 3s + + align:start position:0% +through XA 3s the XT ones through XT 3s + + + align:start position:0% +through XA 3s the XT ones through XT 3s +and the XV ones next through xB threes + + align:start position:0% +and the XV ones next through xB threes + + + align:start position:0% +and the XV ones next through xB threes +that we saw in in the previous video and + + align:start position:0% +that we saw in in the previous video and + + + align:start position:0% +that we saw in in the previous video and +below those we have the objective the + + align:start position:0% +below those we have the objective the + + + align:start position:0% +below those we have the objective the +constraints so that the budgets are not + + align:start position:0% +constraints so that the budgets are not + + + align:start position:0% +constraints so that the budgets are not +exceeded and that the query estimates + + align:start position:0% +exceeded and that the query estimates + + + align:start position:0% +exceeded and that the query estimates +are not exceeded so we will have to fill + + align:start position:0% +are not exceeded so we will have to fill + + + align:start position:0% +are not exceeded so we will have to fill +in all of these expressions which + + align:start position:0% +in all of these expressions which + + + align:start position:0% +in all of these expressions which +reflect for example how many times query + + align:start position:0% +reflect for example how many times query + + + align:start position:0% +reflect for example how many times query +1 is used in our advertising strategy + + align:start position:0% +1 is used in our advertising strategy + + + align:start position:0% +1 is used in our advertising strategy +how much of for instance t-mobile's + + align:start position:0% +how much of for instance t-mobile's + + + align:start position:0% +how much of for instance t-mobile's +budget we use in our advertising + + align:start position:0% +budget we use in our advertising + + + align:start position:0% +budget we use in our advertising +strategy as well as the objective which + + align:start position:0% +strategy as well as the objective which + + + align:start position:0% +strategy as well as the objective which +is the total average revenue from our + + align:start position:0% +is the total average revenue from our + + + align:start position:0% +is the total average revenue from our +advertising strategy let's start by + + align:start position:0% +advertising strategy let's start by + + + align:start position:0% +advertising strategy let's start by +defining the objective of our problem to + + align:start position:0% +defining the objective of our problem to + + + align:start position:0% +defining the objective of our problem to +form the objective we go to the cell + + align:start position:0% +form the objective we go to the cell + + + align:start position:0% +form the objective we go to the cell +next to revenue and we start by writing + + align:start position:0% +next to revenue and we start by writing + + + align:start position:0% +next to revenue and we start by writing +equals sum product the sum product + + align:start position:0% +equals sum product the sum product + + + align:start position:0% +equals sum product the sum product +function takes two collections of cells + + align:start position:0% +function takes two collections of cells + + + align:start position:0% +function takes two collections of cells +multiplies corresponding cells together + + align:start position:0% +multiplies corresponding cells together + + + align:start position:0% +multiplies corresponding cells together +and adds them up here we want to use + + align:start position:0% +and adds them up here we want to use + + + align:start position:0% +and adds them up here we want to use +some product to multiply the average + + align:start position:0% +some product to multiply the average + + + align:start position:0% +some product to multiply the average +prices per display with the number of + + align:start position:0% +prices per display with the number of + + + align:start position:0% +prices per display with the number of +times we display each ad with each query + + align:start position:0% +times we display each ad with each query + + + align:start position:0% +times we display each ad with each query +our variables are all the cells between + + align:start position:0% +our variables are all the cells between + + + align:start position:0% +our variables are all the cells between +be 35 and D 37 and the average price per + + align:start position:0% +be 35 and D 37 and the average price per + + + align:start position:0% +be 35 and D 37 and the average price per +display is contained in all the cells + + align:start position:0% +display is contained in all the cells + + + align:start position:0% +display is contained in all the cells +between b-17 and D 19 so we need to + + align:start position:0% +between b-17 and D 19 so we need to + + + align:start position:0% +between b-17 and D 19 so we need to +input these into the function so we + + align:start position:0% +input these into the function so we + + + align:start position:0% +input these into the function so we +write B 35 through D 37 comma so the + + align:start position:0% +write B 35 through D 37 comma so the + + + align:start position:0% +write B 35 through D 37 comma so the +comma indicates that we are moving on to + + align:start position:0% +comma indicates that we are moving on to + + + align:start position:0% +comma indicates that we are moving on to +a new collection of cells then we + + align:start position:0% +a new collection of cells then we + + + align:start position:0% +a new collection of cells then we +include B 17 through D 19 we press ENTER + + align:start position:0% +include B 17 through D 19 we press ENTER + + + align:start position:0% +include B 17 through D 19 we press ENTER +and so now we have our expression which + + align:start position:0% +and so now we have our expression which + + + align:start position:0% +and so now we have our expression which +reflects the objective value for our + + align:start position:0% +reflects the objective value for our + + + align:start position:0% +reflects the objective value for our +advertising strategy + + align:start position:0% +advertising strategy + + + align:start position:0% +advertising strategy +now to compute how much of each + + align:start position:0% +now to compute how much of each + + + align:start position:0% +now to compute how much of each +advertisers budget we're using we're + + align:start position:0% +advertisers budget we're using we're + + + align:start position:0% +advertisers budget we're using we're +going to use the average price per + + align:start position:0% +going to use the average price per + + + align:start position:0% +going to use the average price per +display and the decision variables of + + align:start position:0% +display and the decision variables of + + + align:start position:0% +display and the decision variables of +each individual advertiser so to get for + + align:start position:0% +each individual advertiser so to get for + + + align:start position:0% +each individual advertiser so to get for +example AT&T s budget usage we would use + + align:start position:0% +example AT&T s budget usage we would use + + + align:start position:0% +example AT&T s budget usage we would use +some product again in the same way that + + align:start position:0% +some product again in the same way that + + + align:start position:0% +some product again in the same way that +we use it for the objective but this + + align:start position:0% +we use it for the objective but this + + + align:start position:0% +we use it for the objective but this +time we would use adjust for AT&T + + align:start position:0% +time we would use adjust for AT&T + + + align:start position:0% +time we would use adjust for AT&T +decision variables and AT&T z' average + + align:start position:0% +decision variables and AT&T z' average + + + align:start position:0% +decision variables and AT&T z' average +prices for display so we use some + + align:start position:0% +prices for display so we use some + + + align:start position:0% +prices for display so we use some +product again as I mentioned so we write + + align:start position:0% +product again as I mentioned so we write + + + align:start position:0% +product again as I mentioned so we write +equals some product but this time we + + align:start position:0% +equals some product but this time we + + + align:start position:0% +equals some product but this time we +select the cells between be 35 and D 35 + + align:start position:0% +select the cells between be 35 and D 35 + + + align:start position:0% +select the cells between be 35 and D 35 +so we write B 35 through D 35 these are + + align:start position:0% +so we write B 35 through D 35 these are + + + align:start position:0% +so we write B 35 through D 35 these are +the cells that correspond to ATT's + + align:start position:0% +the cells that correspond to ATT's + + + align:start position:0% +the cells that correspond to ATT's +decision variables for the second + + align:start position:0% +decision variables for the second + + + align:start position:0% +decision variables for the second +collection of cells we select the cells + + align:start position:0% +collection of cells we select the cells + + + align:start position:0% +collection of cells we select the cells +between b-17 and D 17 these are the + + align:start position:0% +between b-17 and D 17 these are the + + + align:start position:0% +between b-17 and D 17 these are the +cells that correspond to 18 T's average + + align:start position:0% +cells that correspond to 18 T's average + + + align:start position:0% +cells that correspond to 18 T's average +prices per display we can do the same + + align:start position:0% +prices per display we can do the same + + + align:start position:0% +prices per display we can do the same +thing for t-mobile and Verizon and in + + align:start position:0% +thing for t-mobile and Verizon and in + + + align:start position:0% +thing for t-mobile and Verizon and in +this case we don't need to enter the + + align:start position:0% +this case we don't need to enter the + + + align:start position:0% +this case we don't need to enter the +expressions again we can just simply + + align:start position:0% +expressions again we can just simply + + + align:start position:0% +expressions again we can just simply +drag these expressions and the libre + + align:start position:0% +drag these expressions and the libre + + + align:start position:0% +drag these expressions and the libre +office will conveniently fill the + + align:start position:0% +office will conveniently fill the + + + align:start position:0% +office will conveniently fill the +expression expressions and press and now + + align:start position:0% +expression expressions and press and now + + + align:start position:0% +expression expressions and press and now +we need to do a similar thing for the + + align:start position:0% +we need to do a similar thing for the + + + align:start position:0% +we need to do a similar thing for the +number of times that we use each query + + align:start position:0% +number of times that we use each query + + + align:start position:0% +number of times that we use each query +so for example to get the number of + + align:start position:0% +so for example to get the number of + + + align:start position:0% +so for example to get the number of +times query 1 is used we need to add the + + align:start position:0% +times query 1 is used we need to add the + + + align:start position:0% +times query 1 is used we need to add the +cells corresponding to query 1 in the + + align:start position:0% +cells corresponding to query 1 in the + + + align:start position:0% +cells corresponding to query 1 in the +spreadsheet these are the cells + + align:start position:0% +spreadsheet these are the cells + + + align:start position:0% +spreadsheet these are the cells +corresponding to be 35 and B 37 and in + + align:start position:0% +corresponding to be 35 and B 37 and in + + + align:start position:0% +corresponding to be 35 and B 37 and in +this case we're simply we simply need to + + align:start position:0% +this case we're simply we simply need to + + + align:start position:0% +this case we're simply we simply need to +add the decision variable cells we don't + + align:start position:0% +add the decision variable cells we don't + + + align:start position:0% +add the decision variable cells we don't +need to multiply them with any other + + align:start position:0% +need to multiply them with any other + + + align:start position:0% +need to multiply them with any other +cells so we just need to use the sum + + align:start position:0% +cells so we just need to use the sum + + + align:start position:0% +cells so we just need to use the sum +function so we write equals sum and + + align:start position:0% +function so we write equals sum and + + + align:start position:0% +function so we write equals sum and +again we're using the cells b 35 through + + align:start position:0% +again we're using the cells b 35 through + + + align:start position:0% +again we're using the cells b 35 through +B 37 for query two we have to use some + + align:start position:0% +B 37 for query two we have to use some + + + align:start position:0% +B 37 for query two we have to use some +again and we need to sum the cells + + align:start position:0% +again and we need to sum the cells + + + align:start position:0% +again and we need to sum the cells +corresponding to query 2 so we write + + align:start position:0% +corresponding to query 2 so we write + + + align:start position:0% +corresponding to query 2 so we write +equals sum C 35 through C 37 and for + + align:start position:0% +equals sum C 35 through C 37 and for + + + align:start position:0% +equals sum C 35 through C 37 and for +query 3 we need to use some again but + + align:start position:0% +query 3 we need to use some again but + + + align:start position:0% +query 3 we need to use some again but +this time we need to use cells D 35 + + align:start position:0% +this time we need to use cells D 35 + + + align:start position:0% +this time we need to use cells D 35 +through D 37 so we write D 35 : d 37 so + + align:start position:0% +through D 37 so we write D 35 : d 37 so + + + align:start position:0% +through D 37 so we write D 35 : d 37 so +we've now defined all the expressions + + align:start position:0% +we've now defined all the expressions + + + align:start position:0% +we've now defined all the expressions +that we'll need for our + + align:start position:0% +that we'll need for our + + + align:start position:0% +that we'll need for our +now we need to input the decision + + align:start position:0% +now we need to input the decision + + + align:start position:0% +now we need to input the decision +variables the objective and the + + align:start position:0% +variables the objective and the + + + align:start position:0% +variables the objective and the +constraints into the LibreOffice solver + + align:start position:0% +constraints into the LibreOffice solver + + + align:start position:0% +constraints into the LibreOffice solver +so we need to first open up the + + align:start position:0% +so we need to first open up the + + + align:start position:0% +so we need to first open up the +LibreOffice solver so we go to tools we + + align:start position:0% +LibreOffice solver so we go to tools we + + + align:start position:0% +LibreOffice solver so we go to tools we +open up tools and then we click on + + align:start position:0% +open up tools and then we click on + + + align:start position:0% +open up tools and then we click on +solver so to do this now we need to + + align:start position:0% +solver so to do this now we need to + + + align:start position:0% +solver so to do this now we need to +specify again as I mentioned all the + + align:start position:0% +specify again as I mentioned all the + + + align:start position:0% +specify again as I mentioned all the +pieces of the problem so for target cell + + align:start position:0% +pieces of the problem so for target cell + + + align:start position:0% +pieces of the problem so for target cell +so the target cell here is the objective + + align:start position:0% +so the target cell here is the objective + + + align:start position:0% +so the target cell here is the objective +cell so we need to specify our objective + + align:start position:0% +cell so we need to specify our objective + + + align:start position:0% +cell so we need to specify our objective +so this cell was just b14 and we want to + + align:start position:0% +so this cell was just b14 and we want to + + + align:start position:0% +so this cell was just b14 and we want to +maximize this as we're maximizing + + align:start position:0% +maximize this as we're maximizing + + + align:start position:0% +maximize this as we're maximizing +revenue the changing cells here are the + + align:start position:0% +revenue the changing cells here are the + + + align:start position:0% +revenue the changing cells here are the +decision variables so this is just a + + align:start position:0% +decision variables so this is just a + + + align:start position:0% +decision variables so this is just a +collection of cells B 35 through D 37 so + + align:start position:0% +collection of cells B 35 through D 37 so + + + align:start position:0% +collection of cells B 35 through D 37 so +we write B 35 : d 37 now underneath + + align:start position:0% +we write B 35 : d 37 now underneath + + + align:start position:0% +we write B 35 : d 37 now underneath +these rows corresponding to the limiting + + align:start position:0% +these rows corresponding to the limiting + + + align:start position:0% +these rows corresponding to the limiting +conditions these are just the + + align:start position:0% +conditions these are just the + + + align:start position:0% +conditions these are just the +constraints of the problem and the first + + align:start position:0% +constraints of the problem and the first + + + align:start position:0% +constraints of the problem and the first +row here will handle the budget + + align:start position:0% +row here will handle the budget + + + align:start position:0% +row here will handle the budget +constraints so under cell reference will + + align:start position:0% +constraints so under cell reference will + + + align:start position:0% +constraints so under cell reference will +input the budget expression and these + + align:start position:0% +input the budget expression and these + + + align:start position:0% +input the budget expression and these +are contained in cells B 45 through B 47 + + align:start position:0% +are contained in cells B 45 through B 47 + + + align:start position:0% +are contained in cells B 45 through B 47 +so we can enter these or we can just + + align:start position:0% +so we can enter these or we can just + + + align:start position:0% +so we can enter these or we can just +click on the input and the input button + + align:start position:0% +click on the input and the input button + + + align:start position:0% +click on the input and the input button +and just select them in this way and + + align:start position:0% +and just select them in this way and + + + align:start position:0% +and just select them in this way and +then we click on the shrink button here + + align:start position:0% + + + + align:start position:0% + +under operator we want to select less + + align:start position:0% +under operator we want to select less + + + align:start position:0% +under operator we want to select less +than or equal to because we want to + + align:start position:0% +than or equal to because we want to + + + align:start position:0% +than or equal to because we want to +ensure that the amount that we use of + + align:start position:0% +ensure that the amount that we use of + + + align:start position:0% +ensure that the amount that we use of +each budget is less than the total + + align:start position:0% +each budget is less than the total + + + align:start position:0% +each budget is less than the total +budget of the advertiser and here under + + align:start position:0% +budget of the advertiser and here under + + + align:start position:0% +budget of the advertiser and here under +value we're going to select the actual + + align:start position:0% +value we're going to select the actual + + + align:start position:0% +value we're going to select the actual +budget amounts which are on the right + + align:start position:0% +budget amounts which are on the right + + + align:start position:0% +budget amounts which are on the right +hand side of these lesser than equal to + + align:start position:0% +hand side of these lesser than equal to + + + align:start position:0% +hand side of these lesser than equal to +signs so we select them and we put them + + align:start position:0% +signs so we select them and we put them + + + align:start position:0% +signs so we select them and we put them +in so that handles the budget + + align:start position:0% +in so that handles the budget + + + align:start position:0% +in so that handles the budget +constraints and in the second row here + + align:start position:0% +constraints and in the second row here + + + align:start position:0% +constraints and in the second row here +we're going to handle the query estimate + + align:start position:0% +we're going to handle the query estimate + + + align:start position:0% +we're going to handle the query estimate +constraints so here again we under cell + + align:start position:0% +constraints so here again we under cell + + + align:start position:0% +constraints so here again we under cell +reference we're going to specify the + + align:start position:0% +reference we're going to specify the + + + align:start position:0% +reference we're going to specify the +expressions that correspond to how much + + align:start position:0% +expressions that correspond to how much + + + align:start position:0% +expressions that correspond to how much +we use each query in our advertising + + align:start position:0% +we use each query in our advertising + + + align:start position:0% +we use each query in our advertising +strategy and so these are just the cells + + align:start position:0% +strategy and so these are just the cells + + + align:start position:0% +strategy and so these are just the cells +B 50 through B 52 which we select and we + + align:start position:0% +B 50 through B 52 which we select and we + + + align:start position:0% +B 50 through B 52 which we select and we +input them into the solver under + + align:start position:0% +input them into the solver under + + + align:start position:0% +input them into the solver under +operator we want to keep it as less than + + align:start position:0% +operator we want to keep it as less than + + + align:start position:0% +operator we want to keep it as less than +or equal to because we want to ensure + + align:start position:0% +or equal to because we want to ensure + + + align:start position:0% +or equal to because we want to ensure +that the + + align:start position:0% +that the + + + align:start position:0% +that the +amount that we use each query is less + + align:start position:0% +amount that we use each query is less + + + align:start position:0% +amount that we use each query is less +than or equal to the expected number of + + align:start position:0% +than or equal to the expected number of + + + align:start position:0% +than or equal to the expected number of +times that we estimate for that query + + align:start position:0% +times that we estimate for that query + + + align:start position:0% +times that we estimate for that query +and under value we want to input the + + align:start position:0% +and under value we want to input the + + + align:start position:0% +and under value we want to input the +query estimates which are just the cells + + align:start position:0% +query estimates which are just the cells + + + align:start position:0% +query estimates which are just the cells +D 53:52 so we can just select them in + + align:start position:0% +D 53:52 so we can just select them in + + + align:start position:0% +D 53:52 so we can just select them in +this way and input them so at this point + + align:start position:0% +this way and input them so at this point + + + align:start position:0% +this way and input them so at this point +it might be tempting to think that we + + align:start position:0% +it might be tempting to think that we + + + align:start position:0% +it might be tempting to think that we +are done but we have two more things + + align:start position:0% +are done but we have two more things + + + align:start position:0% +are done but we have two more things +that we need to do first we need to tell + + align:start position:0% +that we need to do first we need to tell + + + align:start position:0% +that we need to do first we need to tell +the solver to explicitly treat this as a + + align:start position:0% +the solver to explicitly treat this as a + + + align:start position:0% +the solver to explicitly treat this as a +linear optimization problem second we + + align:start position:0% +linear optimization problem second we + + + align:start position:0% +linear optimization problem second we +need to include another set of + + align:start position:0% +need to include another set of + + + align:start position:0% +need to include another set of +constraints the set of constraints + + align:start position:0% +constraints the set of constraints + + + align:start position:0% +constraints the set of constraints +requires each decision variable to be + + align:start position:0% +requires each decision variable to be + + + align:start position:0% +requires each decision variable to be +greater than or equal to zero since it + + align:start position:0% +greater than or equal to zero since it + + + align:start position:0% +greater than or equal to zero since it +does not make sense to display an + + align:start position:0% +does not make sense to display an + + + align:start position:0% +does not make sense to display an +advertiser with a certain query some + + align:start position:0% +advertiser with a certain query some + + + align:start position:0% +advertiser with a certain query some +negative number of times now while we + + align:start position:0% +negative number of times now while we + + + align:start position:0% +negative number of times now while we +could include these constraints here + + align:start position:0% +could include these constraints here + + + align:start position:0% +could include these constraints here +these types of constraints are very + + align:start position:0% +these types of constraints are very + + + align:start position:0% +these types of constraints are very +common and very typical in linear + + align:start position:0% +common and very typical in linear + + + align:start position:0% +common and very typical in linear +optimization models they come up all the + + align:start position:0% +optimization models they come up all the + + + align:start position:0% +optimization models they come up all the +time and in fact they come up so often + + align:start position:0% +time and in fact they come up so often + + + align:start position:0% +time and in fact they come up so often +that solvers often have an option that + + align:start position:0% +that solvers often have an option that + + + align:start position:0% +that solvers often have an option that +you can toggle that incorporates these + + align:start position:0% +you can toggle that incorporates these + + + align:start position:0% +you can toggle that incorporates these +constraints automatically so to handle + + align:start position:0% +constraints automatically so to handle + + + align:start position:0% +constraints automatically so to handle +both of these considerations let's just + + align:start position:0% +both of these considerations let's just + + + align:start position:0% +both of these considerations let's just +click on options and under options where + + align:start position:0% +click on options and under options where + + + align:start position:0% +click on options and under options where +we have the drop down menu for a solver + + align:start position:0% +we have the drop down menu for a solver + + + align:start position:0% +we have the drop down menu for a solver +engine we'll click on there and then + + align:start position:0% +engine we'll click on there and then + + + align:start position:0% +engine we'll click on there and then +we'll select LibreOffice linear solver + + align:start position:0% +we'll select LibreOffice linear solver + + + align:start position:0% +we'll select LibreOffice linear solver +this indicates the libre office to use + + align:start position:0% +this indicates the libre office to use + + + align:start position:0% +this indicates the libre office to use +the linear optimization solver for this + + align:start position:0% +the linear optimization solver for this + + + align:start position:0% +the linear optimization solver for this +problem and under the settings here one + + align:start position:0% +problem and under the settings here one + + + align:start position:0% +problem and under the settings here one +of the settings is to assume that the + + align:start position:0% +of the settings is to assume that the + + + align:start position:0% +of the settings is to assume that the +variables are non-negative + + align:start position:0% +variables are non-negative + + + align:start position:0% +variables are non-negative +we'll just activate that option and hit + + align:start position:0% +we'll just activate that option and hit + + + align:start position:0% +we'll just activate that option and hit +OK and now we're ready to solve the + + align:start position:0% +OK and now we're ready to solve the + + + align:start position:0% +OK and now we're ready to solve the +problem so if we hit solve we get this + + align:start position:0% +problem so if we hit solve we get this + + + align:start position:0% +problem so if we hit solve we get this +dialogue that says that solving + + align:start position:0% +dialogue that says that solving + + + align:start position:0% +dialogue that says that solving +successfully finished and that a result + + align:start position:0% +successfully finished and that a result + + + align:start position:0% +successfully finished and that a result +in this case this is the objective + + align:start position:0% +in this case this is the objective + + + align:start position:0% +in this case this is the objective +function was 428 so we have an + + align:start position:0% +function was 428 so we have an + + + align:start position:0% +function was 428 so we have an +advertising strategy that achieves a + + align:start position:0% +advertising strategy that achieves a + + + align:start position:0% +advertising strategy that achieves a +average revenue of 428 dollars let's + + align:start position:0% +average revenue of 428 dollars let's + + + align:start position:0% +average revenue of 428 dollars let's +just hit here keep result and just take + + align:start position:0% +just hit here keep result and just take + + + align:start position:0% +just hit here keep result and just take +a look so the cells that we specified as + + align:start position:0% +a look so the cells that we specified as + + + align:start position:0% +a look so the cells that we specified as +the decision variables have been + + align:start position:0% +the decision variables have been + + + align:start position:0% +the decision variables have been +populated with their optimal values so + + align:start position:0% +populated with their optimal values so + + + align:start position:0% +populated with their optimal values so +our optimal strategy based on this + + align:start position:0% +our optimal strategy based on this + + + align:start position:0% +our optimal strategy based on this +linear optimization solution is the + + align:start position:0% +linear optimization solution is the + + + align:start position:0% +linear optimization solution is the +following so we're going to show a TNT + + align:start position:0% +following so we're going to show a TNT + + + align:start position:0% +following so we're going to show a TNT +with query 140 times we're going to show + + align:start position:0% +with query 140 times we're going to show + + + align:start position:0% +with query 140 times we're going to show +AT&T with query 2 also + + align:start position:0% +AT&T with query 2 also + + + align:start position:0% +AT&T with query 2 also +anytime's we're gonna show AT&T with + + align:start position:0% +anytime's we're gonna show AT&T with + + + align:start position:0% +anytime's we're gonna show AT&T with +Korea 380 times for t-mobile will show + + align:start position:0% +Korea 380 times for t-mobile will show + + + align:start position:0% +Korea 380 times for t-mobile will show +t-mobile's ads with query 1 100 times + + align:start position:0% +t-mobile's ads with query 1 100 times + + + align:start position:0% +t-mobile's ads with query 1 100 times +and we're only going to show Verizon's + + align:start position:0% +and we're only going to show Verizon's + + + align:start position:0% +and we're only going to show Verizon's +ads with query 2 and we're going to show + + align:start position:0% +ads with query 2 and we're going to show + + + align:start position:0% +ads with query 2 and we're going to show +it 40 times so this specifies completely + + align:start position:0% +it 40 times so this specifies completely + + + align:start position:0% +it 40 times so this specifies completely +the advertising strategy that Google + + align:start position:0% +the advertising strategy that Google + + + align:start position:0% +the advertising strategy that Google +should use and the strategy as we just + + align:start position:0% +should use and the strategy as we just + + + align:start position:0% +should use and the strategy as we just +saw achieves an average revenue of four + + align:start position:0% +saw achieves an average revenue of four + + + align:start position:0% +saw achieves an average revenue of four +hundred and twenty eight dollars let's + + align:start position:0% +hundred and twenty eight dollars let's + + + align:start position:0% +hundred and twenty eight dollars let's +double check that the solution is + + align:start position:0% +double check that the solution is + + + align:start position:0% +double check that the solution is +feasible by looking at the budgets and + + align:start position:0% +feasible by looking at the budgets and + + + align:start position:0% +feasible by looking at the budgets and +the query estimates so if we scroll down + + align:start position:0% +the query estimates so if we scroll down + + + align:start position:0% +the query estimates so if we scroll down +here we see that the budget of that 18 + + align:start position:0% +here we see that the budget of that 18 + + + align:start position:0% +here we see that the budget of that 18 +T's budget that we use here is one + + align:start position:0% +T's budget that we use here is one + + + align:start position:0% +T's budget that we use here is one +hundred sixty eight dollars + + align:start position:0% +hundred sixty eight dollars + + + align:start position:0% +hundred sixty eight dollars +18 T's actual budget is 170 dollars and + + align:start position:0% +18 T's actual budget is 170 dollars and + + + align:start position:0% +18 T's actual budget is 170 dollars and +we can see that for the other two + + align:start position:0% +we can see that for the other two + + + align:start position:0% +we can see that for the other two +advertisers that we are in the clear for + + align:start position:0% +advertisers that we are in the clear for + + + align:start position:0% +advertisers that we are in the clear for +both of them similarly with the query + + align:start position:0% +both of them similarly with the query + + + align:start position:0% +both of them similarly with the query +estimates we can see that for all the + + align:start position:0% +estimates we can see that for all the + + + align:start position:0% +estimates we can see that for all the +query all the queries that we are + + align:start position:0% +query all the queries that we are + + + align:start position:0% +query all the queries that we are +considering here we do not use any query + + align:start position:0% +considering here we do not use any query + + + align:start position:0% +considering here we do not use any query +more than the estimate for the number of + + align:start position:0% +more than the estimate for the number of + + + align:start position:0% +more than the estimate for the number of +times we expect to see that query and + + align:start position:0% +times we expect to see that query and + + + align:start position:0% +times we expect to see that query and +finally as one last check all the + + align:start position:0% +finally as one last check all the + + + align:start position:0% +finally as one last check all the +decision variable values that we see + + align:start position:0% +decision variable values that we see + + + align:start position:0% +decision variable values that we see +here are all greater than or equal to + + align:start position:0% +here are all greater than or equal to + + + align:start position:0% +here are all greater than or equal to +serum so we're not using any advertiser + + align:start position:0% +serum so we're not using any advertiser + + + align:start position:0% +serum so we're not using any advertiser +with any query a negative number of + + align:start position:0% +with any query a negative number of + + + align:start position:0% +with any query a negative number of +times which obviously would not make + + align:start position:0% +times which obviously would not make + + + align:start position:0% +times which obviously would not make +sense so the solution as a whole is a + + align:start position:0% +sense so the solution as a whole is a + + + align:start position:0% +sense so the solution as a whole is a +feasible solution in the next video + + align:start position:0% +feasible solution in the next video + + + align:start position:0% +feasible solution in the next video +we'll show how to solve the problem + + align:start position:0% +we'll show how to solve the problem + + + align:start position:0% +we'll show how to solve the problem +using a greedy common-sense approach + + align:start position:0% +using a greedy common-sense approach + + + align:start position:0% +using a greedy common-sense approach +where we will allocate ads to queries by + + align:start position:0% +where we will allocate ads to queries by + + + align:start position:0% +where we will allocate ads to queries by +prioritizing them by their average price + + align:start position:0% +prioritizing them by their average price + + + align:start position:0% +prioritizing them by their average price +per display \ No newline at end of file diff --git a/b5DKpnHXuUU.txt b/b5DKpnHXuUU.txt new file mode 100644 index 0000000000000000000000000000000000000000..895ebf4627cb6fd66d30994354bd13d7e169056d --- /dev/null +++ b/b5DKpnHXuUU.txt @@ -0,0 +1,5203 @@ +align:start position:0% + +welcome back to 8701 so in this + + align:start position:0% +welcome back to 8701 so in this + + + align:start position:0% +welcome back to 8701 so in this +section of our discussion of + + align:start position:0% +section of our discussion of + + + align:start position:0% +section of our discussion of +instrumentation + + align:start position:0% +instrumentation + + + align:start position:0% +instrumentation +we talk about accelerators and i'll do + + align:start position:0% +we talk about accelerators and i'll do + + + align:start position:0% +we talk about accelerators and i'll do +this in a in a little bit of an historic + + align:start position:0% +this in a in a little bit of an historic + + + align:start position:0% +this in a in a little bit of an historic +way + + align:start position:0% +way + + + align:start position:0% +way +showing you some of the developments + + align:start position:0% +showing you some of the developments + + + align:start position:0% +showing you some of the developments +over the last + + align:start position:0% +over the last + + + align:start position:0% +over the last +up to 100 years + + align:start position:0% + + + + align:start position:0% + +you know we use electromagnetic fields + + align:start position:0% +you know we use electromagnetic fields + + + align:start position:0% +you know we use electromagnetic fields +in order to accelerate + + align:start position:0% +in order to accelerate + + + align:start position:0% +in order to accelerate +charged particles and so the + + align:start position:0% +charged particles and so the + + + align:start position:0% +charged particles and so the +developments + + align:start position:0% +developments + + + align:start position:0% +developments +in electromagnetism and understanding + + align:start position:0% +in electromagnetism and understanding + + + align:start position:0% +in electromagnetism and understanding +electromagnetism + + align:start position:0% +electromagnetism + + + align:start position:0% +electromagnetism +led to then you know the technical + + align:start position:0% +led to then you know the technical + + + align:start position:0% +led to then you know the technical +developments of the technological + + align:start position:0% +developments of the technological + + + align:start position:0% +developments of the technological +development + + align:start position:0% +development + + + align:start position:0% +development +of accelerators and availability of + + align:start position:0% +of accelerators and availability of + + + align:start position:0% +of accelerators and availability of +devices which can be used in order to + + align:start position:0% +devices which can be used in order to + + + align:start position:0% +devices which can be used in order to +accelerate + + align:start position:0% +accelerate + + + align:start position:0% +accelerate +or modify particles and so this goes + + align:start position:0% +or modify particles and so this goes + + + align:start position:0% +or modify particles and so this goes +back to maxwell + + align:start position:0% +back to maxwell + + + align:start position:0% +back to maxwell +and hertz discovering electromagnetic + + align:start position:0% +and hertz discovering electromagnetic + + + align:start position:0% +and hertz discovering electromagnetic +waves + + align:start position:0% +waves + + + align:start position:0% +waves +towards jj thompson who + + align:start position:0% +towards jj thompson who + + + align:start position:0% +towards jj thompson who +was able to use cathode rays + + align:start position:0% +was able to use cathode rays + + + align:start position:0% +was able to use cathode rays +and classical lawrence force in order to + + align:start position:0% +and classical lawrence force in order to + + + align:start position:0% +and classical lawrence force in order to +understand the electromagnetic fields + + align:start position:0% +understand the electromagnetic fields + + + align:start position:0% +understand the electromagnetic fields +if we study uh particle accelerators we + + align:start position:0% +if we study uh particle accelerators we + + + align:start position:0% +if we study uh particle accelerators we +can see + + align:start position:0% +can see + + + align:start position:0% +can see +three different historic lines the + + align:start position:0% +three different historic lines the + + + align:start position:0% +three different historic lines the +direct voltage + + align:start position:0% +direct voltage + + + align:start position:0% +direct voltage +accelerators resonant accelerators and + + align:start position:0% +accelerators resonant accelerators and + + + align:start position:0% +accelerators resonant accelerators and +transformer accelerate and so we go + + align:start position:0% +transformer accelerate and so we go + + + align:start position:0% +transformer accelerate and so we go +through those three different + + align:start position:0% +through those three different + + + align:start position:0% +through those three different +subjects one by one the energy limits + + align:start position:0% +subjects one by one the energy limits + + + align:start position:0% +subjects one by one the energy limits +of our accelerators they're typically + + align:start position:0% +of our accelerators they're typically + + + align:start position:0% +of our accelerators they're typically +given by the maximum possible voltage + + align:start position:0% +given by the maximum possible voltage + + + align:start position:0% +given by the maximum possible voltage +available + + align:start position:0% + + + + align:start position:0% + +when you're thinking about accelerators + + align:start position:0% +when you're thinking about accelerators + + + align:start position:0% +when you're thinking about accelerators +used + + align:start position:0% +used + + + align:start position:0% +used +for colliding beams um it's not just + + align:start position:0% +for colliding beams um it's not just + + + align:start position:0% +for colliding beams um it's not just +the energy which is a limiting factor + + align:start position:0% +the energy which is a limiting factor + + + align:start position:0% +the energy which is a limiting factor +but you also need + + align:start position:0% +but you also need + + + align:start position:0% +but you also need +a sufficient number of particles to be + + align:start position:0% +a sufficient number of particles to be + + + align:start position:0% +a sufficient number of particles to be +accelerated + + align:start position:0% +accelerated + + + align:start position:0% +accelerated +and brought to collisions and those + + align:start position:0% +and brought to collisions and those + + + align:start position:0% +and brought to collisions and those +particles need to be + + align:start position:0% +particles need to be + + + align:start position:0% +particles need to be +in some sort of beam which is narrow + + align:start position:0% +in some sort of beam which is narrow + + + align:start position:0% +in some sort of beam which is narrow +such that collisions are possible + + align:start position:0% +such that collisions are possible + + + align:start position:0% +such that collisions are possible +requirements change depending on whether + + align:start position:0% +requirements change depending on whether + + + align:start position:0% +requirements change depending on whether +or not you have colliding beams or fixed + + align:start position:0% +or not you have colliding beams or fixed + + + align:start position:0% +or not you have colliding beams or fixed +target experiments + + align:start position:0% +target experiments + + + align:start position:0% +target experiments +whether or not you actually study lepton + + align:start position:0% +whether or not you actually study lepton + + + align:start position:0% +whether or not you actually study lepton +collisions or + + align:start position:0% +collisions or + + + align:start position:0% +collisions or +headround collisions uh whether or not + + align:start position:0% +headround collisions uh whether or not + + + align:start position:0% +headround collisions uh whether or not +you're using secondary particles as + + align:start position:0% +you're using secondary particles as + + + align:start position:0% +you're using secondary particles as +the means of what you're going to learn + + align:start position:0% +the means of what you're going to learn + + + align:start position:0% +the means of what you're going to learn +from this but the concepts are + + align:start position:0% +from this but the concepts are + + + align:start position:0% +from this but the concepts are +very comparable across those individual + + align:start position:0% +very comparable across those individual + + + align:start position:0% +very comparable across those individual +fields of study + + align:start position:0% +fields of study + + + align:start position:0% +fields of study +so let's start with the vandermeer van + + align:start position:0% +so let's start with the vandermeer van + + + align:start position:0% +so let's start with the vandermeer van +der graaf accelerator + + align:start position:0% +der graaf accelerator + + + align:start position:0% +der graaf accelerator +so you basically you know have to + + align:start position:0% +so you basically you know have to + + + align:start position:0% +so you basically you know have to +be able to create large voltages and for + + align:start position:0% +be able to create large voltages and for + + + align:start position:0% +be able to create large voltages and for +the wonder graph accelerator + + align:start position:0% +the wonder graph accelerator + + + align:start position:0% +the wonder graph accelerator +is being doing is creating this large + + align:start position:0% +is being doing is creating this large + + + align:start position:0% +is being doing is creating this large +voltage by just + + align:start position:0% +voltage by just + + + align:start position:0% +voltage by just +moving particles um + + align:start position:0% +moving particles um + + + align:start position:0% +moving particles um +particles from from one level separating + + align:start position:0% +particles from from one level separating + + + align:start position:0% +particles from from one level separating +particles to create this large voltage + + align:start position:0% +particles to create this large voltage + + + align:start position:0% +particles to create this large voltage +um you can typically get up to you know + + align:start position:0% +um you can typically get up to you know + + + align:start position:0% +um you can typically get up to you know +mega volts and tens of mega volts of + + align:start position:0% +mega volts and tens of mega volts of + + + align:start position:0% +mega volts and tens of mega volts of +of voltages um but you may need to make + + align:start position:0% +of voltages um but you may need to make + + + align:start position:0% +of voltages um but you may need to make +sure that you don't + + align:start position:0% +sure that you don't + + + align:start position:0% +sure that you don't +enter a breakdown kind of regime and so + + align:start position:0% +enter a breakdown kind of regime and so + + + align:start position:0% +enter a breakdown kind of regime and so +it depends on what kind of insulating + + align:start position:0% +it depends on what kind of insulating + + + align:start position:0% +it depends on what kind of insulating +materials you use + + align:start position:0% +materials you use + + + align:start position:0% +materials you use +you know if you are in using insulating + + align:start position:0% +you know if you are in using insulating + + + align:start position:0% +you know if you are in using insulating +gas + + align:start position:0% +gas + + + align:start position:0% +gas +under certain environmental conditions + + align:start position:0% +under certain environmental conditions + + + align:start position:0% +under certain environmental conditions +you get up to + + align:start position:0% +you get up to + + + align:start position:0% +you get up to +17.5 mega volts which then can be used + + align:start position:0% +17.5 mega volts which then can be used + + + align:start position:0% +17.5 mega volts which then can be used +in order to accelerate + + align:start position:0% +in order to accelerate + + + align:start position:0% +in order to accelerate +you can use the fact that you can use + + align:start position:0% +you can use the fact that you can use + + + align:start position:0% +you can use the fact that you can use +the electric field + + align:start position:0% +the electric field + + + align:start position:0% +the electric field +twice in the tandem accelerators by you + + align:start position:0% +twice in the tandem accelerators by you + + + align:start position:0% +twice in the tandem accelerators by you +know just changing + + align:start position:0% +know just changing + + + align:start position:0% +know just changing +uh changing the direction of the voltage + + align:start position:0% +uh changing the direction of the voltage + + + align:start position:0% +uh changing the direction of the voltage +um large potential differences have been + + align:start position:0% +um large potential differences have been + + + align:start position:0% +um large potential differences have been +you know have been a field of studies in + + align:start position:0% +you know have been a field of studies in + + + align:start position:0% +you know have been a field of studies in +the in the 1920s and 30s + + align:start position:0% +the in the 1920s and 30s + + + align:start position:0% +the in the 1920s and 30s +and um one you know not so + + align:start position:0% +and um one you know not so + + + align:start position:0% +and um one you know not so +and it's just noteworthy that this is a + + align:start position:0% +and it's just noteworthy that this is a + + + align:start position:0% +and it's just noteworthy that this is a +dangerous field so brush and langer + + align:start position:0% +dangerous field so brush and langer + + + align:start position:0% +dangerous field so brush and langer +they used potential from lightning in + + align:start position:0% +they used potential from lightning in + + + align:start position:0% +they used potential from lightning in +the swiss alps but + + align:start position:0% +the swiss alps but + + + align:start position:0% +the swiss alps but +this was fatal for longer who was + + align:start position:0% +this was fatal for longer who was + + + align:start position:0% +this was fatal for longer who was +electrically electrocuted fatally + + align:start position:0% +electrically electrocuted fatally + + + align:start position:0% +electrically electrocuted fatally +on by lightning strike + + align:start position:0% + + + + align:start position:0% + +so then you need to think about how can + + align:start position:0% +so then you need to think about how can + + + align:start position:0% +so then you need to think about how can +you make your large voltages available + + align:start position:0% +you make your large voltages available + + + align:start position:0% +you make your large voltages available +and how can you make them available for + + align:start position:0% +and how can you make them available for + + + align:start position:0% +and how can you make them available for +acceleration + + align:start position:0% +acceleration + + + align:start position:0% +acceleration +um quakkrov walton accelerators + + align:start position:0% +um quakkrov walton accelerators + + + align:start position:0% +um quakkrov walton accelerators +use a sequence of a cascade generator in + + align:start position:0% +use a sequence of a cascade generator in + + + align:start position:0% +use a sequence of a cascade generator in +order to + + align:start position:0% +order to + + + align:start position:0% +order to +you know reuse the voltage in order to + + align:start position:0% +you know reuse the voltage in order to + + + align:start position:0% +you know reuse the voltage in order to +create a larger potential for + + align:start position:0% +create a larger potential for + + + align:start position:0% +create a larger potential for +acceleration + + align:start position:0% +acceleration + + + align:start position:0% +acceleration +the marks generator is very conceptually + + align:start position:0% +the marks generator is very conceptually + + + align:start position:0% +the marks generator is very conceptually +very very similar + + align:start position:0% +very very similar + + + align:start position:0% +very very similar +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +those are still used today so we know + + align:start position:0% +those are still used today so we know + + + align:start position:0% +those are still used today so we know +why those developments are + + align:start position:0% +why those developments are + + + align:start position:0% +why those developments are +uh you know 80 or 90 years old um + + align:start position:0% +uh you know 80 or 90 years old um + + + align:start position:0% +uh you know 80 or 90 years old um +you know if you go to a physics today + + align:start position:0% +you know if you go to a physics today + + + align:start position:0% +you know if you go to a physics today +article from 2003 you see that a machine + + align:start position:0% +article from 2003 you see that a machine + + + align:start position:0% +article from 2003 you see that a machine +like this is being used + + align:start position:0% +like this is being used + + + align:start position:0% +like this is being used +um in order to create the initial + + align:start position:0% +um in order to create the initial + + + align:start position:0% +um in order to create the initial +confinement for fusion + + align:start position:0% +confinement for fusion + + + align:start position:0% +confinement for fusion +reactors and the total power is + + align:start position:0% +reactors and the total power is + + + align:start position:0% +reactors and the total power is +rather fascinating 4 terabytes which can + + align:start position:0% +rather fascinating 4 terabytes which can + + + align:start position:0% +rather fascinating 4 terabytes which can +be released in 100 nanoseconds + + align:start position:0% +be released in 100 nanoseconds + + + align:start position:0% +be released in 100 nanoseconds +from a larger number of those marks + + align:start position:0% +from a larger number of those marks + + + align:start position:0% +from a larger number of those marks +generators + + align:start position:0% +generators + + + align:start position:0% +generators +in modern particle physics accelerators + + align:start position:0% +in modern particle physics accelerators + + + align:start position:0% +in modern particle physics accelerators +we use + + align:start position:0% +we use + + + align:start position:0% +we use +uh resonant acceleration quite a lot and + + align:start position:0% +uh resonant acceleration quite a lot and + + + align:start position:0% +uh resonant acceleration quite a lot and +the idea is really like it's shown in + + align:start position:0% +the idea is really like it's shown in + + + align:start position:0% +the idea is really like it's shown in +this picture here + + align:start position:0% +this picture here + + + align:start position:0% +this picture here +that the charged particles they're kind + + align:start position:0% +that the charged particles they're kind + + + align:start position:0% +that the charged particles they're kind +of being accelerated on a wave + + align:start position:0% +of being accelerated on a wave + + + align:start position:0% +of being accelerated on a wave +so basically they're surfing on + + align:start position:0% +so basically they're surfing on + + + align:start position:0% +so basically they're surfing on +electromagnetic waves + + align:start position:0% +electromagnetic waves + + + align:start position:0% +electromagnetic waves +and this can be seen here you just place + + align:start position:0% +and this can be seen here you just place + + + align:start position:0% +and this can be seen here you just place +them correctly in your waveform + + align:start position:0% +them correctly in your waveform + + + align:start position:0% +them correctly in your waveform +on a specific point and then they can be + + align:start position:0% +on a specific point and then they can be + + + align:start position:0% +on a specific point and then they can be +accelerated + + align:start position:0% +accelerated + + + align:start position:0% +accelerated +over some distance so the the key + + align:start position:0% +over some distance so the the key + + + align:start position:0% +over some distance so the the key +point here is that you have uh + + align:start position:0% +point here is that you have uh + + + align:start position:0% +point here is that you have uh +a proper or correct phase relation uh to + + align:start position:0% +a proper or correct phase relation uh to + + + align:start position:0% +a proper or correct phase relation uh to +the accelerating voltage + + align:start position:0% +the accelerating voltage + + + align:start position:0% +the accelerating voltage +and the setup can be you know varying + + align:start position:0% +and the setup can be you know varying + + + align:start position:0% +and the setup can be you know varying +and historically there's + + align:start position:0% +and historically there's + + + align:start position:0% +and historically there's +various attempts to do this in an + + align:start position:0% +various attempts to do this in an + + + align:start position:0% +various attempts to do this in an +optimal way + + align:start position:0% + + + + align:start position:0% + +the first one is the cyclotron which you + + align:start position:0% +the first one is the cyclotron which you + + + align:start position:0% +the first one is the cyclotron which you +know has a static + + align:start position:0% +know has a static + + + align:start position:0% +know has a static +magnetic field and in each turn + + align:start position:0% +magnetic field and in each turn + + + align:start position:0% +magnetic field and in each turn +you know your particles are being + + align:start position:0% +you know your particles are being + + + align:start position:0% +you know your particles are being +injected and then + + align:start position:0% +injected and then + + + align:start position:0% +injected and then +in each turn your particle is getting a + + align:start position:0% +in each turn your particle is getting a + + + align:start position:0% +in each turn your particle is getting a +kick here and a kick here and + + align:start position:0% +kick here and a kick here and + + + align:start position:0% +kick here and a kick here and +because their velocity is increasing + + align:start position:0% +because their velocity is increasing + + + align:start position:0% +because their velocity is increasing +their radius + + align:start position:0% +their radius + + + align:start position:0% +their radius +in a fixed magnetic field is increasing + + align:start position:0% +in a fixed magnetic field is increasing + + + align:start position:0% +in a fixed magnetic field is increasing +as well + + align:start position:0% +as well + + + align:start position:0% +as well +so at some after some time the is + + align:start position:0% +so at some after some time the is + + + align:start position:0% +so at some after some time the is +accelerated and leaves the cyclotron + + align:start position:0% +accelerated and leaves the cyclotron + + + align:start position:0% +accelerated and leaves the cyclotron +with a specific velocity + + align:start position:0% + + + + align:start position:0% + +focusing here is important you don't + + align:start position:0% +focusing here is important you don't + + + align:start position:0% +focusing here is important you don't +want to just inject particles and then + + align:start position:0% +want to just inject particles and then + + + align:start position:0% +want to just inject particles and then +they'll spray all over the place + + align:start position:0% +they'll spray all over the place + + + align:start position:0% +they'll spray all over the place +and you know in accelerators four sticks + + align:start position:0% +and you know in accelerators four sticks + + + align:start position:0% +and you know in accelerators four sticks +and having the right optics for + + align:start position:0% +and having the right optics for + + + align:start position:0% +and having the right optics for +the particle is a key part of the work + + align:start position:0% +the particle is a key part of the work + + + align:start position:0% +the particle is a key part of the work +work needed here there's a number of + + align:start position:0% +work needed here there's a number of + + + align:start position:0% +work needed here there's a number of +techniques + + align:start position:0% +techniques + + + align:start position:0% +techniques +i don't want to go into too much detail + + align:start position:0% +i don't want to go into too much detail + + + align:start position:0% +i don't want to go into too much detail +but what you + + align:start position:0% +but what you + + + align:start position:0% +but what you +typically see is if you compress the + + align:start position:0% +typically see is if you compress the + + + align:start position:0% +typically see is if you compress the +beam in one direction + + align:start position:0% +beam in one direction + + + align:start position:0% +beam in one direction +it decompresses in the other direction + + align:start position:0% +it decompresses in the other direction + + + align:start position:0% +it decompresses in the other direction +and so quadruple + + align:start position:0% +and so quadruple + + + align:start position:0% +and so quadruple +magnets can be used in order to you know + + align:start position:0% +magnets can be used in order to you know + + + align:start position:0% +magnets can be used in order to you know +get some focusing and you use um you + + align:start position:0% +get some focusing and you use um you + + + align:start position:0% +get some focusing and you use um you +know fringe fields and edge fields in + + align:start position:0% +know fringe fields and edge fields in + + + align:start position:0% +know fringe fields and edge fields in +order to make sure that the beam itself + + align:start position:0% +order to make sure that the beam itself + + + align:start position:0% +order to make sure that the beam itself +stays in a compact form you can also you + + align:start position:0% +stays in a compact form you can also you + + + align:start position:0% +stays in a compact form you can also you +know + + align:start position:0% +know + + + align:start position:0% +know +do techniques where you know you have a + + align:start position:0% +do techniques where you know you have a + + + align:start position:0% +do techniques where you know you have a +initial focusing in one direction and + + align:start position:0% +initial focusing in one direction and + + + align:start position:0% +initial focusing in one direction and +then in the other direction so the + + align:start position:0% +then in the other direction so the + + + align:start position:0% +then in the other direction so the +resulting b + + align:start position:0% +resulting b + + + align:start position:0% +resulting b +can be made made smaller + + align:start position:0% + + + + align:start position:0% + +accelerators are not just important + + align:start position:0% +accelerators are not just important + + + align:start position:0% +accelerators are not just important +today in + + align:start position:0% +today in + + + align:start position:0% +today in +particle physics but they are + + align:start position:0% +particle physics but they are + + + align:start position:0% +particle physics but they are +specifically + + align:start position:0% +specifically + + + align:start position:0% +specifically +found their place in medical + + align:start position:0% +found their place in medical + + + align:start position:0% +found their place in medical +applications in tumor therapy + + align:start position:0% +applications in tumor therapy + + + align:start position:0% +applications in tumor therapy +specifically and the history here is + + align:start position:0% +specifically and the history here is + + + align:start position:0% +specifically and the history here is +very long you see those initial + + align:start position:0% +very long you see those initial + + + align:start position:0% +very long you see those initial +ideas or methods where neutrons are used + + align:start position:0% +ideas or methods where neutrons are used + + + align:start position:0% +ideas or methods where neutrons are used +10 mev neutrons are used in order to + + align:start position:0% +10 mev neutrons are used in order to + + + align:start position:0% +10 mev neutrons are used in order to +treat + + align:start position:0% +treat + + + align:start position:0% +treat +tumors um we haven't discussed this in + + align:start position:0% +tumors um we haven't discussed this in + + + align:start position:0% +tumors um we haven't discussed this in +nuclear physics too much but when you + + align:start position:0% +nuclear physics too much but when you + + + align:start position:0% +nuclear physics too much but when you +use ions as a radiation form you can + + align:start position:0% +use ions as a radiation form you can + + + align:start position:0% +use ions as a radiation form you can +really pinpoint where energy is + + align:start position:0% +really pinpoint where energy is + + + align:start position:0% +really pinpoint where energy is +deposited + + align:start position:0% +deposited + + + align:start position:0% +deposited +um the so-called black peak is used in + + align:start position:0% +um the so-called black peak is used in + + + align:start position:0% +um the so-called black peak is used in +order to you know + + align:start position:0% +order to you know + + + align:start position:0% +order to you know +precisely figure out in a + + align:start position:0% +precisely figure out in a + + + align:start position:0% +precisely figure out in a +three-dimensional way where the energy + + align:start position:0% +three-dimensional way where the energy + + + align:start position:0% +three-dimensional way where the energy +of them + + align:start position:0% +of them + + + align:start position:0% +of them +of the ions is being deposited this is + + align:start position:0% +of the ions is being deposited this is + + + align:start position:0% +of the ions is being deposited this is +in contrast to + + align:start position:0% +in contrast to + + + align:start position:0% +in contrast to +radiation tier with these photons where + + align:start position:0% +radiation tier with these photons where + + + align:start position:0% +radiation tier with these photons where +you just basically spray a larger part + + align:start position:0% +you just basically spray a larger part + + + align:start position:0% +you just basically spray a larger part +of + + align:start position:0% +of + + + align:start position:0% +of +the live life material and you know just + + align:start position:0% +the live life material and you know just + + + align:start position:0% +the live life material and you know just +destroy the cancerous cells but also + + align:start position:0% +destroy the cancerous cells but also + + + align:start position:0% +destroy the cancerous cells but also +the ones which are still healthy um + + align:start position:0% +the ones which are still healthy um + + + align:start position:0% +the ones which are still healthy um +you know any given larger hospital + + align:start position:0% +you know any given larger hospital + + + align:start position:0% +you know any given larger hospital +nowadays has a small accelerator + + align:start position:0% +nowadays has a small accelerator + + + align:start position:0% +nowadays has a small accelerator +and so there's thousands and thousands + + align:start position:0% +and so there's thousands and thousands + + + align:start position:0% +and so there's thousands and thousands +of those available + + align:start position:0% +of those available + + + align:start position:0% +of those available +and the work and the maintenance of + + align:start position:0% +and the work and the maintenance of + + + align:start position:0% +and the work and the maintenance of +those is rather important + + align:start position:0% +those is rather important + + + align:start position:0% +those is rather important +but continuing the discussion of + + align:start position:0% +but continuing the discussion of + + + align:start position:0% +but continuing the discussion of +accelerator concepts + + align:start position:0% +accelerator concepts + + + align:start position:0% +accelerator concepts +um you know this kind of racetrack + + align:start position:0% +um you know this kind of racetrack + + + align:start position:0% +um you know this kind of racetrack +accelerators + + align:start position:0% +accelerators + + + align:start position:0% +accelerators +um are quite interesting you basically + + align:start position:0% +um are quite interesting you basically + + + align:start position:0% +um are quite interesting you basically +have a couple of + + align:start position:0% +have a couple of + + + align:start position:0% +have a couple of +uh fixed nets and your particles being + + align:start position:0% +uh fixed nets and your particles being + + + align:start position:0% +uh fixed nets and your particles being +injected + + align:start position:0% +injected + + + align:start position:0% +injected +and is you know getting like in the + + align:start position:0% +and is you know getting like in the + + + align:start position:0% +and is you know getting like in the +cyclotron larger and larger kicks + + align:start position:0% +cyclotron larger and larger kicks + + + align:start position:0% +cyclotron larger and larger kicks +and then at some points can be ejected + + align:start position:0% +and then at some points can be ejected + + + align:start position:0% +and then at some points can be ejected +in order to do experiments + + align:start position:0% +in order to do experiments + + + align:start position:0% +in order to do experiments +again this is not the technology which + + align:start position:0% +again this is not the technology which + + + align:start position:0% +again this is not the technology which +is you know not + + align:start position:0% +is you know not + + + align:start position:0% +is you know not +used anymore mummy is an accelerator at + + align:start position:0% +used anymore mummy is an accelerator at + + + align:start position:0% +used anymore mummy is an accelerator at +university of mainz and it's it's um + + align:start position:0% +university of mainz and it's it's um + + + align:start position:0% +university of mainz and it's it's um +the next generation is using the next + + align:start position:0% +the next generation is using the next + + + align:start position:0% +the next generation is using the next +generation of accelerators at this + + align:start position:0% +generation of accelerators at this + + + align:start position:0% +generation of accelerators at this +facility is using + + align:start position:0% +facility is using + + + align:start position:0% +facility is using +a similar technology + + align:start position:0% +a similar technology + + + align:start position:0% +a similar technology +the question is you know what kind of + + align:start position:0% +the question is you know what kind of + + + align:start position:0% +the question is you know what kind of +conditions you have to fulfill in order + + align:start position:0% +conditions you have to fulfill in order + + + align:start position:0% +conditions you have to fulfill in order +to keep the particles in place + + align:start position:0% +to keep the particles in place + + + align:start position:0% +to keep the particles in place +and here you know because the particle + + align:start position:0% +and here you know because the particle + + + align:start position:0% +and here you know because the particle +moves along it in each turn takes more + + align:start position:0% +moves along it in each turn takes more + + + align:start position:0% +moves along it in each turn takes more +time in order to make + + align:start position:0% +time in order to make + + + align:start position:0% +time in order to make +one circulation so what you want to make + + align:start position:0% +one circulation so what you want to make + + + align:start position:0% +one circulation so what you want to make +sure is that + + align:start position:0% +sure is that + + + align:start position:0% +sure is that +your face and the acceleration stays + + align:start position:0% +your face and the acceleration stays + + + align:start position:0% +your face and the acceleration stays +in in sync so you want to make sure that + + align:start position:0% +in in sync so you want to make sure that + + + align:start position:0% +in in sync so you want to make sure that +you know the particle + + align:start position:0% +you know the particle + + + align:start position:0% +you know the particle +when it comes around again gets another + + align:start position:0% +when it comes around again gets another + + + align:start position:0% +when it comes around again gets another +kick and it's not de-accelerated + + align:start position:0% +kick and it's not de-accelerated + + + align:start position:0% +kick and it's not de-accelerated +and so that explains why in those + + align:start position:0% +and so that explains why in those + + + align:start position:0% +and so that explains why in those +machines uh + + align:start position:0% +machines uh + + + align:start position:0% +machines uh +the particles are bunched they come in + + align:start position:0% +the particles are bunched they come in + + + align:start position:0% +the particles are bunched they come in +little blocks of particles + + align:start position:0% +little blocks of particles + + + align:start position:0% +little blocks of particles +instead of just being a continuous + + align:start position:0% +instead of just being a continuous + + + align:start position:0% +instead of just being a continuous +stream of particles and you can work out + + align:start position:0% +stream of particles and you can work out + + + align:start position:0% +stream of particles and you can work out +the conditions + + align:start position:0% +the conditions + + + align:start position:0% +the conditions +are necessary in order to fulfill the + + align:start position:0% +are necessary in order to fulfill the + + + align:start position:0% +are necessary in order to fulfill the +requirement that particles are being + + align:start position:0% +requirement that particles are being + + + align:start position:0% +requirement that particles are being +continuously accelerated + + align:start position:0% +continuously accelerated + + + align:start position:0% +continuously accelerated +um so then there's you know over the + + align:start position:0% +um so then there's you know over the + + + align:start position:0% +um so then there's you know over the +history + + align:start position:0% +history + + + align:start position:0% +history +a number of technologies which which + + align:start position:0% +a number of technologies which which + + + align:start position:0% +a number of technologies which which +make + + align:start position:0% +make + + + align:start position:0% +make +try to make use of the fact that when + + align:start position:0% +try to make use of the fact that when + + + align:start position:0% +try to make use of the fact that when +you accelerate the velocity of the + + align:start position:0% +you accelerate the velocity of the + + + align:start position:0% +you accelerate the velocity of the +particles increases + + align:start position:0% +particles increases + + + align:start position:0% +particles increases +so initially at a specific time + + align:start position:0% +so initially at a specific time + + + align:start position:0% +so initially at a specific time +with one sequence the particle gets + + align:start position:0% +with one sequence the particle gets + + + align:start position:0% +with one sequence the particle gets +a kick and then in the next time it's + + align:start position:0% +a kick and then in the next time it's + + + align:start position:0% +a kick and then in the next time it's +already faster + + align:start position:0% +already faster + + + align:start position:0% +already faster +it needs it travels further so you can + + align:start position:0% +it needs it travels further so you can + + + align:start position:0% +it needs it travels further so you can +there's video + + align:start position:0% +there's video + + + align:start position:0% +there's video +linux linear accelerator structures you + + align:start position:0% +linux linear accelerator structures you + + + align:start position:0% +linux linear accelerator structures you +just increase the length of + + align:start position:0% +just increase the length of + + + align:start position:0% +just increase the length of +each accelerator structure in order to + + align:start position:0% +each accelerator structure in order to + + + align:start position:0% +each accelerator structure in order to +make sure that + + align:start position:0% +make sure that + + + align:start position:0% +make sure that +you again can give particles the + + align:start position:0% +you again can give particles the + + + align:start position:0% +you again can give particles the +necessary kick + + align:start position:0% + + + + align:start position:0% + +nowadays we use cavities and we use + + align:start position:0% +nowadays we use cavities and we use + + + align:start position:0% +nowadays we use cavities and we use +superconducting cavities in order to + + align:start position:0% +superconducting cavities in order to + + + align:start position:0% +superconducting cavities in order to +make some energy efficient in order to + + align:start position:0% +make some energy efficient in order to + + + align:start position:0% +make some energy efficient in order to +have large gradients + + align:start position:0% +have large gradients + + + align:start position:0% +have large gradients +uh the general idea is again that you + + align:start position:0% +uh the general idea is again that you + + + align:start position:0% +uh the general idea is again that you +know you place your particle in here + + align:start position:0% +know you place your particle in here + + + align:start position:0% +know you place your particle in here +and you place it such in your face in + + align:start position:0% +and you place it such in your face in + + + align:start position:0% +and you place it such in your face in +your electromagnetic + + align:start position:0% +your electromagnetic + + + align:start position:0% +your electromagnetic +varying electromagnetic fields that it + + align:start position:0% +varying electromagnetic fields that it + + + align:start position:0% +varying electromagnetic fields that it +always gets a kick + + align:start position:0% +always gets a kick + + + align:start position:0% +always gets a kick +instead of being on the other side and + + align:start position:0% +instead of being on the other side and + + + align:start position:0% +instead of being on the other side and +being de-accelerated + + align:start position:0% + + + + align:start position:0% + +again the alvarez linux is a very + + align:start position:0% +again the alvarez linux is a very + + + align:start position:0% +again the alvarez linux is a very +similar concept + + align:start position:0% +similar concept + + + align:start position:0% +similar concept +um the advantage here is that you only + + align:start position:0% +um the advantage here is that you only + + + align:start position:0% +um the advantage here is that you only +have one power input + + align:start position:0% +have one power input + + + align:start position:0% +have one power input +which then you couple and you know the + + align:start position:0% +which then you couple and you know the + + + align:start position:0% +which then you couple and you know the +walls of the machine don't dissipate + + align:start position:0% +walls of the machine don't dissipate + + + align:start position:0% +walls of the machine don't dissipate +energy + + align:start position:0% +energy + + + align:start position:0% +energy +so then the next you know once you have + + align:start position:0% +so then the next you know once you have + + + align:start position:0% +so then the next you know once you have +an accelerator structure in place + + align:start position:0% +an accelerator structure in place + + + align:start position:0% +an accelerator structure in place +you also want to make sure that the + + align:start position:0% +you also want to make sure that the + + + align:start position:0% +you also want to make sure that the +structure itself doesn't interfere with + + align:start position:0% +structure itself doesn't interfere with + + + align:start position:0% +structure itself doesn't interfere with +the beam + + align:start position:0% +the beam + + + align:start position:0% +the beam +that the power transfer is as efficient + + align:start position:0% +that the power transfer is as efficient + + + align:start position:0% +that the power transfer is as efficient +as possible + + align:start position:0% +as possible + + + align:start position:0% +as possible +um such that you can you know get four + + align:start position:0% +um such that you can you know get four + + + align:start position:0% +um such that you can you know get four +more for your buck + + align:start position:0% + + + + align:start position:0% + +all right i mentioned this a few times + + align:start position:0% +all right i mentioned this a few times + + + align:start position:0% +all right i mentioned this a few times +already the + + align:start position:0% +already the + + + align:start position:0% +already the +you know the the fact when you have + + align:start position:0% + + + + align:start position:0% + +an electromagnetic wave of this form and + + align:start position:0% +an electromagnetic wave of this form and + + + align:start position:0% +an electromagnetic wave of this form and +you put your particle + + align:start position:0% +you put your particle + + + align:start position:0% +you put your particle +here the question is what happens with + + align:start position:0% +here the question is what happens with + + + align:start position:0% +here the question is what happens with +particles which have a slightly higher + + align:start position:0% +particles which have a slightly higher + + + align:start position:0% +particles which have a slightly higher +energy + + align:start position:0% +energy + + + align:start position:0% +energy +or with particles which have a slightly + + align:start position:0% +or with particles which have a slightly + + + align:start position:0% +or with particles which have a slightly +lower energy and it turns out that you + + align:start position:0% +lower energy and it turns out that you + + + align:start position:0% +lower energy and it turns out that you +know this kind of wave has a + + align:start position:0% +know this kind of wave has a + + + align:start position:0% +know this kind of wave has a +self-focusing kind of structure + + align:start position:0% +self-focusing kind of structure + + + align:start position:0% +self-focusing kind of structure +in a sense that you know the particles + + align:start position:0% +in a sense that you know the particles + + + align:start position:0% +in a sense that you know the particles +were a little bit behind + + align:start position:0% +were a little bit behind + + + align:start position:0% +were a little bit behind +they get a little bit larger kick + + align:start position:0% +they get a little bit larger kick + + + align:start position:0% +they get a little bit larger kick +particles which are a little bit in + + align:start position:0% +particles which are a little bit in + + + align:start position:0% +particles which are a little bit in +front they get a little bit + + align:start position:0% +front they get a little bit + + + align:start position:0% +front they get a little bit +lower kick which means overall in energy + + align:start position:0% +lower kick which means overall in energy + + + align:start position:0% +lower kick which means overall in energy +you focus your bunch and energy and + + align:start position:0% +you focus your bunch and energy and + + + align:start position:0% +you focus your bunch and energy and +space + + align:start position:0% +space + + + align:start position:0% +space +will focus a bunch you can go one step + + align:start position:0% +will focus a bunch you can go one step + + + align:start position:0% +will focus a bunch you can go one step +further using + + align:start position:0% +further using + + + align:start position:0% +further using +if quadrupoles again no details given + + align:start position:0% +if quadrupoles again no details given + + + align:start position:0% +if quadrupoles again no details given +here + + align:start position:0% +here + + + align:start position:0% +here +you use those units in order to further + + align:start position:0% +you use those units in order to further + + + align:start position:0% +you use those units in order to further +squeeze the beam + + align:start position:0% +squeeze the beam + + + align:start position:0% +squeeze the beam +and reduce the footprint in energy and + + align:start position:0% +and reduce the footprint in energy and + + + align:start position:0% +and reduce the footprint in energy and +space + + align:start position:0% +space + + + align:start position:0% +space +the phase space your particles are + + align:start position:0% +the phase space your particles are + + + align:start position:0% +the phase space your particles are +occupying + + align:start position:0% + + + + align:start position:0% + +all right you you know + + align:start position:0% +all right you you know + + + align:start position:0% +all right you you know +the the next level here is then to use a + + align:start position:0% +the the next level here is then to use a + + + align:start position:0% +the the next level here is then to use a +better tron + + align:start position:0% +better tron + + + align:start position:0% +better tron +and the idea of the betatron is that + + align:start position:0% +and the idea of the betatron is that + + + align:start position:0% +and the idea of the betatron is that +you change the magnetic field as you go + + align:start position:0% +you change the magnetic field as you go + + + align:start position:0% +you change the magnetic field as you go +instead of changing the size of the + + align:start position:0% +instead of changing the size of the + + + align:start position:0% +instead of changing the size of the +structure you change the magnetic field + + align:start position:0% +structure you change the magnetic field + + + align:start position:0% +structure you change the magnetic field +so you can use the same structure + + align:start position:0% +so you can use the same structure + + + align:start position:0% +so you can use the same structure +in order to confine your beams and the + + align:start position:0% +in order to confine your beams and the + + + align:start position:0% +in order to confine your beams and the +the next level to this is that you just + + align:start position:0% +the next level to this is that you just + + + align:start position:0% +the next level to this is that you just +use one magnet + + align:start position:0% +use one magnet + + + align:start position:0% +use one magnet +use many magnets and this is done in + + align:start position:0% +use many magnets and this is done in + + + align:start position:0% +use many magnets and this is done in +encyclotrons modern synchrotrons + + align:start position:0% +encyclotrons modern synchrotrons + + + align:start position:0% +encyclotrons modern synchrotrons +um so here again a large + + align:start position:0% +um so here again a large + + + align:start position:0% +um so here again a large +line in history but the point is that + + align:start position:0% +line in history but the point is that + + + align:start position:0% +line in history but the point is that +you know when you + + align:start position:0% +you know when you + + + align:start position:0% +you know when you +use the same orbit for the particles why + + align:start position:0% +use the same orbit for the particles why + + + align:start position:0% +use the same orbit for the particles why +you accelerate them + + align:start position:0% +you accelerate them + + + align:start position:0% +you accelerate them +your magnet structures can become much + + align:start position:0% +your magnet structures can become much + + + align:start position:0% +your magnet structures can become much +much smaller + + align:start position:0% +much smaller + + + align:start position:0% +much smaller +so you have many small magnets instead + + align:start position:0% +so you have many small magnets instead + + + align:start position:0% +so you have many small magnets instead +of one large magnet + + align:start position:0% +of one large magnet + + + align:start position:0% +of one large magnet +and only one or a few accelerator + + align:start position:0% +and only one or a few accelerator + + + align:start position:0% +and only one or a few accelerator +sections are needed + + align:start position:0% +sections are needed + + + align:start position:0% +sections are needed +so the particle passes by here it's + + align:start position:0% +so the particle passes by here it's + + + align:start position:0% +so the particle passes by here it's +being accelerated + + align:start position:0% +being accelerated + + + align:start position:0% +being accelerated +and then you have magnets of course the + + align:start position:0% +and then you have magnets of course the + + + align:start position:0% +and then you have magnets of course the +link as the + + align:start position:0% +link as the + + + align:start position:0% +link as the +ring which is which are able to change + + align:start position:0% +ring which is which are able to change + + + align:start position:0% +ring which is which are able to change +their field strengths um you know again + + align:start position:0% +their field strengths um you know again + + + align:start position:0% +their field strengths um you know again +if you have constant field strengths + + align:start position:0% +if you have constant field strengths + + + align:start position:0% +if you have constant field strengths +the radius changes but if you're + + align:start position:0% +the radius changes but if you're + + + align:start position:0% +the radius changes but if you're +modifying the field strength accordingly + + align:start position:0% +modifying the field strength accordingly + + + align:start position:0% +modifying the field strength accordingly +to the speed of the particle + + align:start position:0% +to the speed of the particle + + + align:start position:0% +to the speed of the particle +you can keep particles in the same + + align:start position:0% +you can keep particles in the same + + + align:start position:0% +you can keep particles in the same +circular structure + + align:start position:0% + + + + align:start position:0% + +more words on the focusing again if you + + align:start position:0% +more words on the focusing again if you + + + align:start position:0% +more words on the focusing again if you +if you space the magnet such that + + align:start position:0% +if you space the magnet such that + + + align:start position:0% +if you space the magnet such that +there's a gradient in the fields between + + align:start position:0% +there's a gradient in the fields between + + + align:start position:0% +there's a gradient in the fields between +depending on the position you can use + + align:start position:0% +depending on the position you can use + + + align:start position:0% +depending on the position you can use +that fact in order to + + align:start position:0% +that fact in order to + + + align:start position:0% +that fact in order to +have particles which are further out + + align:start position:0% +have particles which are further out + + + align:start position:0% +have particles which are further out +being bent more inwards + + align:start position:0% +being bent more inwards + + + align:start position:0% +being bent more inwards +particles which are further inwards and + + align:start position:0% +particles which are further inwards and + + + align:start position:0% +particles which are further inwards and +more outward this is called weak + + align:start position:0% +more outward this is called weak + + + align:start position:0% +more outward this is called weak +focusing + + align:start position:0% +focusing + + + align:start position:0% +focusing +and you can do this not just once but + + align:start position:0% +and you can do this not just once but + + + align:start position:0% +and you can do this not just once but +twice by changing the rotation and then + + align:start position:0% +twice by changing the rotation and then + + + align:start position:0% +twice by changing the rotation and then +that's that called + + align:start position:0% +that's that called + + + align:start position:0% +that's that called +strong focusing + + align:start position:0% + + + + align:start position:0% + +synchrotrons have limitations um there's + + align:start position:0% +synchrotrons have limitations um there's + + + align:start position:0% +synchrotrons have limitations um there's +two which are rather important the first + + align:start position:0% +two which are rather important the first + + + align:start position:0% +two which are rather important the first +one + + align:start position:0% +one + + + align:start position:0% +one +the radius of the synchrotron is + + align:start position:0% +the radius of the synchrotron is + + + align:start position:0% +the radius of the synchrotron is +determined by the momentum of the + + align:start position:0% +determined by the momentum of the + + + align:start position:0% +determined by the momentum of the +particle + + align:start position:0% +particle + + + align:start position:0% +particle +and your magnetic field so at some point + + align:start position:0% +and your magnetic field so at some point + + + align:start position:0% +and your magnetic field so at some point +you run into technical limitations on + + align:start position:0% +you run into technical limitations on + + + align:start position:0% +you run into technical limitations on +the magnetic field strength + + align:start position:0% +the magnetic field strength + + + align:start position:0% +the magnetic field strength +modern superconducting magnets they get + + align:start position:0% +modern superconducting magnets they get + + + align:start position:0% +modern superconducting magnets they get +up to + + align:start position:0% +up to + + + align:start position:0% +up to +in the order of eight nine tesla we are + + align:start position:0% +in the order of eight nine tesla we are + + + align:start position:0% +in the order of eight nine tesla we are +able to produce + + align:start position:0% +able to produce + + + align:start position:0% +able to produce +accelerator crate magnets of up to 14 + + align:start position:0% +accelerator crate magnets of up to 14 + + + align:start position:0% +accelerator crate magnets of up to 14 +tesla + + align:start position:0% +tesla + + + align:start position:0% +tesla +using superconducting materials and so + + align:start position:0% +using superconducting materials and so + + + align:start position:0% +using superconducting materials and so +that gen + + align:start position:0% +that gen + + + align:start position:0% +that gen +with a fixed size of your tunnel of your + + align:start position:0% +with a fixed size of your tunnel of your + + + align:start position:0% +with a fixed size of your tunnel of your +ring + + align:start position:0% +ring + + + align:start position:0% +ring +limits the amount of momentum you can + + align:start position:0% +limits the amount of momentum you can + + + align:start position:0% +limits the amount of momentum you can +give or energy you can give to your + + align:start position:0% +give or energy you can give to your + + + align:start position:0% +give or energy you can give to your +particle + + align:start position:0% +particle + + + align:start position:0% +particle +and so for the + + align:start position:0% +and so for the + + + align:start position:0% +and so for the +lhc we accelerate protons up to 70 ev + + align:start position:0% +lhc we accelerate protons up to 70 ev + + + align:start position:0% +lhc we accelerate protons up to 70 ev +in one beam and we use the magnetic + + align:start position:0% +in one beam and we use the magnetic + + + align:start position:0% +in one beam and we use the magnetic +field of 8.4 tesla + + align:start position:0% +field of 8.4 tesla + + + align:start position:0% +field of 8.4 tesla +so that's really the maximum the machine + + align:start position:0% +so that's really the maximum the machine + + + align:start position:0% +so that's really the maximum the machine +can actually deliver and we haven't + + align:start position:0% +can actually deliver and we haven't + + + align:start position:0% +can actually deliver and we haven't +actually demonstrated that we can get up + + align:start position:0% +actually demonstrated that we can get up + + + align:start position:0% +actually demonstrated that we can get up +to this point right now + + align:start position:0% +to this point right now + + + align:start position:0% +to this point right now +the center of mars the important energy + + align:start position:0% +the center of mars the important energy + + + align:start position:0% +the center of mars the important energy +is + + align:start position:0% +is + + + align:start position:0% +is +6.5 tv the previous concept + + align:start position:0% +6.5 tv the previous concept + + + align:start position:0% +6.5 tv the previous concept +and construction had started in texas in + + align:start position:0% +and construction had started in texas in + + + align:start position:0% +and construction had started in texas in +the united states + + align:start position:0% +the united states + + + align:start position:0% +the united states +in the so-called ssc tunnel which much + + align:start position:0% +in the so-called ssc tunnel which much + + + align:start position:0% +in the so-called ssc tunnel which much +much larger + + align:start position:0% +much larger + + + align:start position:0% +much larger +acquired 87 kilometer an 87 kilometer + + align:start position:0% +acquired 87 kilometer an 87 kilometer + + + align:start position:0% +acquired 87 kilometer an 87 kilometer +tunnel + + align:start position:0% +tunnel + + + align:start position:0% +tunnel +the idea was to get protons to center to + + align:start position:0% +the idea was to get protons to center to + + + align:start position:0% +the idea was to get protons to center to +energies of 20 tv + + align:start position:0% +energies of 20 tv + + + align:start position:0% +energies of 20 tv +with magnets of 6.8 tesla + + align:start position:0% + + + + align:start position:0% + +okay this is one limitation the size of + + align:start position:0% +okay this is one limitation the size of + + + align:start position:0% +okay this is one limitation the size of +your tunnel the second one is + + align:start position:0% +your tunnel the second one is + + + align:start position:0% +your tunnel the second one is +when you bend a charged particle + + align:start position:0% +when you bend a charged particle + + + align:start position:0% +when you bend a charged particle +with a magnetic field it radiates and it + + align:start position:0% +with a magnetic field it radiates and it + + + align:start position:0% +with a magnetic field it radiates and it +radiates + + align:start position:0% +radiates + + + align:start position:0% +radiates +proportional of the energy proportion of + + align:start position:0% +proportional of the energy proportion of + + + align:start position:0% +proportional of the energy proportion of +energy over mass + + align:start position:0% +energy over mass + + + align:start position:0% +energy over mass +to the fourth power which means that + + align:start position:0% +to the fourth power which means that + + + align:start position:0% +to the fourth power which means that +you at some point are limited + + align:start position:0% +you at some point are limited + + + align:start position:0% +you at some point are limited +by the power you have to invest in the + + align:start position:0% +by the power you have to invest in the + + + align:start position:0% +by the power you have to invest in the +beam to even just keep it at a specific + + align:start position:0% +beam to even just keep it at a specific + + + align:start position:0% +beam to even just keep it at a specific +energy + + align:start position:0% +energy + + + align:start position:0% +energy +so this is e over m + + align:start position:0% +so this is e over m + + + align:start position:0% +so this is e over m +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +n to the fourth power + + align:start position:0% +n to the fourth power + + + align:start position:0% +n to the fourth power +and um this also gives you a clue why we + + align:start position:0% +and um this also gives you a clue why we + + + align:start position:0% +and um this also gives you a clue why we +actually accelerate protons in the lhc + + align:start position:0% +actually accelerate protons in the lhc + + + align:start position:0% +actually accelerate protons in the lhc +and not electrons + + align:start position:0% +and not electrons + + + align:start position:0% +and not electrons +the electron mass is too low and you + + align:start position:0% +the electron mass is too low and you + + + align:start position:0% +the electron mass is too low and you +know this goes to the fourth power here + + align:start position:0% +know this goes to the fourth power here + + + align:start position:0% +know this goes to the fourth power here +the the lincoln radiation of electrons + + align:start position:0% +the the lincoln radiation of electrons + + + align:start position:0% +the the lincoln radiation of electrons +in the lhd tunnel is just the limiting + + align:start position:0% +in the lhd tunnel is just the limiting + + + align:start position:0% +in the lhd tunnel is just the limiting +factor at some point you don't have + + align:start position:0% +factor at some point you don't have + + + align:start position:0% +factor at some point you don't have +enough power anymore in order to give + + align:start position:0% +enough power anymore in order to give + + + align:start position:0% +enough power anymore in order to give +that to the electrons or the particles + + align:start position:0% +that to the electrons or the particles + + + align:start position:0% +that to the electrons or the particles +in order to accelerate them + + align:start position:0% + + + + align:start position:0% + +all right so as i was saying initially + + align:start position:0% +all right so as i was saying initially + + + align:start position:0% +all right so as i was saying initially +so you need + + align:start position:0% +so you need + + + align:start position:0% +so you need +focusing you need accelerating and you + + align:start position:0% +focusing you need accelerating and you + + + align:start position:0% +focusing you need accelerating and you +need + + align:start position:0% +need + + + align:start position:0% +need +you know all kinds of additional + + align:start position:0% +you know all kinds of additional + + + align:start position:0% +you know all kinds of additional +components to + + align:start position:0% +components to + + + align:start position:0% +components to +an accelerator in order to make good + + align:start position:0% +an accelerator in order to make good + + + align:start position:0% +an accelerator in order to make good +colliding beams + + align:start position:0% +colliding beams + + + align:start position:0% +colliding beams +and so it's much easier to just dump a + + align:start position:0% +and so it's much easier to just dump a + + + align:start position:0% +and so it's much easier to just dump a +beam into a fixed target and study + + align:start position:0% +beam into a fixed target and study + + + align:start position:0% +beam into a fixed target and study +what's coming out so colliding beams as + + align:start position:0% +what's coming out so colliding beams as + + + align:start position:0% +what's coming out so colliding beams as +a source for input into particle physics + + align:start position:0% +a source for input into particle physics + + + align:start position:0% +a source for input into particle physics +experiments came a little bit later + + align:start position:0% +experiments came a little bit later + + + align:start position:0% +experiments came a little bit later +first concepts came to fruition and + + align:start position:0% +first concepts came to fruition and + + + align:start position:0% +first concepts came to fruition and +fascadi in the 1960s + + align:start position:0% +fascadi in the 1960s + + + align:start position:0% +fascadi in the 1960s +and then we had spear a electron + + align:start position:0% +and then we had spear a electron + + + align:start position:0% +and then we had spear a electron +positron collided + + align:start position:0% +positron collided + + + align:start position:0% +positron collided +in center of mass energy of 4 gb which + + align:start position:0% +in center of mass energy of 4 gb which + + + align:start position:0% +in center of mass energy of 4 gb which +then led to the discovery of the jsi + + align:start position:0% +then led to the discovery of the jsi + + + align:start position:0% +then led to the discovery of the jsi +um and then later we had a + + align:start position:0% +um and then later we had a + + + align:start position:0% +um and then later we had a +5 gb electron position collider which + + align:start position:0% +5 gb electron position collider which + + + align:start position:0% +5 gb electron position collider which +was then + + align:start position:0% +was then + + + align:start position:0% +was then +designed for for 8gb this then + + align:start position:0% +designed for for 8gb this then + + + align:start position:0% +designed for for 8gb this then +continued + + align:start position:0% +continued + + + align:start position:0% +continued +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +as you know to machines like lab + + align:start position:0% +as you know to machines like lab + + + align:start position:0% +as you know to machines like lab +which had a center of mass energy of up + + align:start position:0% +which had a center of mass energy of up + + + align:start position:0% +which had a center of mass energy of up +to 210 gev + + align:start position:0% +to 210 gev + + + align:start position:0% +to 210 gev +and the lhc the center of mass energy of + + align:start position:0% +and the lhc the center of mass energy of + + + align:start position:0% +and the lhc the center of mass energy of +design of 14 tv + + align:start position:0% +design of 14 tv + + + align:start position:0% +design of 14 tv +so the collider elements what do you + + align:start position:0% +so the collider elements what do you + + + align:start position:0% +so the collider elements what do you +need um + + align:start position:0% +need um + + + align:start position:0% +need um +you need to inject particles and so you + + align:start position:0% +you need to inject particles and so you + + + align:start position:0% +you need to inject particles and so you +have to have a source of electrons + + align:start position:0% +have to have a source of electrons + + + align:start position:0% +have to have a source of electrons +and the source of positrons producing + + align:start position:0% +and the source of positrons producing + + + align:start position:0% +and the source of positrons producing +positrons is just + + align:start position:0% +positrons is just + + + align:start position:0% +positrons is just +you know technologically in large + + align:start position:0% +you know technologically in large + + + align:start position:0% +you know technologically in large +numbers much more complicated than + + align:start position:0% +numbers much more complicated than + + + align:start position:0% +numbers much more complicated than +electrons + + align:start position:0% +electrons + + + align:start position:0% +electrons +um here you can you know just + + align:start position:0% + + + + align:start position:0% + +in order to get sufficient electrons you + + align:start position:0% +in order to get sufficient electrons you + + + align:start position:0% +in order to get sufficient electrons you +need to actually + + align:start position:0% +need to actually + + + align:start position:0% +need to actually +um produce them with a + + align:start position:0% +um produce them with a + + + align:start position:0% +um produce them with a +kind of an accelerator structure as well + + align:start position:0% +kind of an accelerator structure as well + + + align:start position:0% +kind of an accelerator structure as well +and so then they you know need to be + + align:start position:0% +and so then they you know need to be + + + align:start position:0% +and so then they you know need to be +focused they need to be cooled down + + align:start position:0% +focused they need to be cooled down + + + align:start position:0% +focused they need to be cooled down +in order to have them as a beam being + + align:start position:0% +in order to have them as a beam being + + + align:start position:0% +in order to have them as a beam being +injected in the structure + + align:start position:0% +injected in the structure + + + align:start position:0% +injected in the structure +so you what you need as additional + + align:start position:0% +so you what you need as additional + + + align:start position:0% +so you what you need as additional +components you need your + + align:start position:0% +components you need your + + + align:start position:0% +components you need your +your i have generators you need magnets + + align:start position:0% +your i have generators you need magnets + + + align:start position:0% +your i have generators you need magnets +to bend the beam in and out um you need + + align:start position:0% +to bend the beam in and out um you need + + + align:start position:0% +to bend the beam in and out um you need +to + + align:start position:0% +to + + + align:start position:0% +to +have magnets in order to bend the beam + + align:start position:0% +have magnets in order to bend the beam + + + align:start position:0% +have magnets in order to bend the beam +around so we need bending magnets you + + align:start position:0% +around so we need bending magnets you + + + align:start position:0% +around so we need bending magnets you +need focusing magnets to keep + + align:start position:0% +need focusing magnets to keep + + + align:start position:0% +need focusing magnets to keep +the beam in orbit and then you want to + + align:start position:0% +the beam in orbit and then you want to + + + align:start position:0% +the beam in orbit and then you want to +before you bring them to the collision + + align:start position:0% +before you bring them to the collision + + + align:start position:0% +before you bring them to the collision +you want to further focus the beam such + + align:start position:0% +you want to further focus the beam such + + + align:start position:0% +you want to further focus the beam such +that you have more + + align:start position:0% +that you have more + + + align:start position:0% +that you have more +actual particle collisions available and + + align:start position:0% +actual particle collisions available and + + + align:start position:0% +actual particle collisions available and +then you have interaction points where + + align:start position:0% +then you have interaction points where + + + align:start position:0% +then you have interaction points where +you will put your particle physics + + align:start position:0% +you will put your particle physics + + + align:start position:0% +you will put your particle physics +experiment + + align:start position:0% + + + + align:start position:0% + +um what's being done here in this in + + align:start position:0% +um what's being done here in this in + + + align:start position:0% +um what's being done here in this in +this facilities is you + + align:start position:0% +this facilities is you + + + align:start position:0% +this facilities is you +you inject you accelerate and then you + + align:start position:0% +you inject you accelerate and then you + + + align:start position:0% +you inject you accelerate and then you +store the beam + + align:start position:0% +store the beam + + + align:start position:0% +store the beam +to make sure that you can fully exploit + + align:start position:0% +to make sure that you can fully exploit + + + align:start position:0% +to make sure that you can fully exploit +the structure so + + align:start position:0% +the structure so + + + align:start position:0% +the structure so +those strings are called storage rings + + align:start position:0% +those strings are called storage rings + + + align:start position:0% +those strings are called storage rings +you avoid you know having a one kind of + + align:start position:0% +you avoid you know having a one kind of + + + align:start position:0% +you avoid you know having a one kind of +short kind of mentality as you have for + + align:start position:0% +short kind of mentality as you have for + + + align:start position:0% +short kind of mentality as you have for +example in linear machine + + align:start position:0% +example in linear machine + + + align:start position:0% +example in linear machine +sometimes you do this in separate rings + + align:start position:0% +sometimes you do this in separate rings + + + align:start position:0% +sometimes you do this in separate rings +sometimes you do this in the same ring + + align:start position:0% +sometimes you do this in the same ring + + + align:start position:0% +sometimes you do this in the same ring +that depends on the design of the + + align:start position:0% +that depends on the design of the + + + align:start position:0% +that depends on the design of the +machine the challenges are + + align:start position:0% +machine the challenges are + + + align:start position:0% +machine the challenges are +if you have particles travel around for + + align:start position:0% +if you have particles travel around for + + + align:start position:0% +if you have particles travel around for +hours that they shouldn't interact with + + align:start position:0% +hours that they shouldn't interact with + + + align:start position:0% +hours that they shouldn't interact with +some + + align:start position:0% +some + + + align:start position:0% +some +gas for example in your accelerator + + align:start position:0% +gas for example in your accelerator + + + align:start position:0% +gas for example in your accelerator +structure you require + + align:start position:0% +structure you require + + + align:start position:0% +structure you require +a very very good vacuum in order to not + + align:start position:0% +a very very good vacuum in order to not + + + align:start position:0% +a very very good vacuum in order to not +lose the beam + + align:start position:0% +lose the beam + + + align:start position:0% +lose the beam +as you have it stored the fields of your + + align:start position:0% +as you have it stored the fields of your + + + align:start position:0% +as you have it stored the fields of your +accelerator structures need to be very + + align:start position:0% +accelerator structures need to be very + + + align:start position:0% +accelerator structures need to be very +stable and that stable + + align:start position:0% +stable and that stable + + + align:start position:0% +stable and that stable +they have to be stable for many many + + align:start position:0% +they have to be stable for many many + + + align:start position:0% +they have to be stable for many many +hours that for example there's some + + align:start position:0% +hours that for example there's some + + + align:start position:0% +hours that for example there's some +some requirements on on your uh + + align:start position:0% +some requirements on on your uh + + + align:start position:0% +some requirements on on your uh +electric grid for example such that you + + align:start position:0% +electric grid for example such that you + + + align:start position:0% +electric grid for example such that you +know you have the stability in voltages + + align:start position:0% +know you have the stability in voltages + + + align:start position:0% +know you have the stability in voltages +which + + align:start position:0% +which + + + align:start position:0% +which +don't end up changing the + + align:start position:0% +don't end up changing the + + + align:start position:0% +don't end up changing the +actual field strength of your magnet as + + align:start position:0% +actual field strength of your magnet as + + + align:start position:0% +actual field strength of your magnet as +you go along + + align:start position:0% +you go along + + + align:start position:0% +you go along +um yeah so again i already mentioned + + align:start position:0% +um yeah so again i already mentioned + + + align:start position:0% +um yeah so again i already mentioned +this the further developments of those + + align:start position:0% +this the further developments of those + + + align:start position:0% +this the further developments of those +machines + + align:start position:0% +machines + + + align:start position:0% +machines +um you know in the 80s at cern + + align:start position:0% +um you know in the 80s at cern + + + align:start position:0% +um you know in the 80s at cern +you know stochastic cooling was used for + + align:start position:0% +you know stochastic cooling was used for + + + align:start position:0% +you know stochastic cooling was used for +the first time + + align:start position:0% +the first time + + + align:start position:0% +the first time +in an anti-proton portrand machine + + align:start position:0% +in an anti-proton portrand machine + + + align:start position:0% +in an anti-proton portrand machine +and that machine led to the discovery of + + align:start position:0% +and that machine led to the discovery of + + + align:start position:0% +and that machine led to the discovery of +the w and the z bosons + + align:start position:0% +the w and the z bosons + + + align:start position:0% +the w and the z bosons +and and first really deeply study of the + + align:start position:0% +and and first really deeply study of the + + + align:start position:0% +and and first really deeply study of the +weak interactions at the scale of the + + align:start position:0% +weak interactions at the scale of the + + + align:start position:0% +weak interactions at the scale of the +weak interaction + + align:start position:0% +weak interaction + + + align:start position:0% +weak interaction +um at the tabletron in close to chicago + + align:start position:0% +um at the tabletron in close to chicago + + + align:start position:0% +um at the tabletron in close to chicago +um you know protons and antiprotons were + + align:start position:0% +um you know protons and antiprotons were + + + align:start position:0% +um you know protons and antiprotons were +brought to connect + + align:start position:0% +brought to connect + + + align:start position:0% +brought to connect +collisions at the thermal at fermilab at + + align:start position:0% +collisions at the thermal at fermilab at + + + align:start position:0% +collisions at the thermal at fermilab at +the fermi national accelerator + + align:start position:0% +the fermi national accelerator + + + align:start position:0% +the fermi national accelerator +laboratory + + align:start position:0% +laboratory + + + align:start position:0% +laboratory +um and then lab started in the late + + align:start position:0% +um and then lab started in the late + + + align:start position:0% +um and then lab started in the late +1980s + + align:start position:0% +1980s + + + align:start position:0% +1980s +in the same tunnel as we find today the + + align:start position:0% +in the same tunnel as we find today the + + + align:start position:0% +in the same tunnel as we find today the +lhc + + align:start position:0% +lhc + + + align:start position:0% +lhc +at daisy in hamburg + + align:start position:0% +at daisy in hamburg + + + align:start position:0% +at daisy in hamburg +hera was used to collide electrons with + + align:start position:0% +hera was used to collide electrons with + + + align:start position:0% +hera was used to collide electrons with +protons + + align:start position:0% +protons + + + align:start position:0% +protons +and those results send that to an + + align:start position:0% +and those results send that to an + + + align:start position:0% +and those results send that to an +understanding of the structure of the + + align:start position:0% +understanding of the structure of the + + + align:start position:0% +understanding of the structure of the +proton + + align:start position:0% +proton + + + align:start position:0% +proton +so you see that the reason why i show + + align:start position:0% +so you see that the reason why i show + + + align:start position:0% +so you see that the reason why i show +you this history here is + + align:start position:0% +you this history here is + + + align:start position:0% +you this history here is +that the the progress we did in particle + + align:start position:0% +that the the progress we did in particle + + + align:start position:0% +that the the progress we did in particle +physics + + align:start position:0% +physics + + + align:start position:0% +physics +at the energy frontier each of the + + align:start position:0% +at the energy frontier each of the + + + align:start position:0% +at the energy frontier each of the +energy frontiers + + align:start position:0% +energy frontiers + + + align:start position:0% +energy frontiers +was very much tied to the progress in + + align:start position:0% +was very much tied to the progress in + + + align:start position:0% +was very much tied to the progress in +accelerator + + align:start position:0% +accelerator + + + align:start position:0% +accelerator +structures and rightfully so um simon + + align:start position:0% +structures and rightfully so um simon + + + align:start position:0% +structures and rightfully so um simon +fundamenta received the nobel prize + + align:start position:0% +fundamenta received the nobel prize + + + align:start position:0% +fundamenta received the nobel prize +in physics as an accelerator physicist + + align:start position:0% +in physics as an accelerator physicist + + + align:start position:0% +in physics as an accelerator physicist +for the discovery of the w and z button + + align:start position:0% +for the discovery of the w and z button + + + align:start position:0% +for the discovery of the w and z button +um he was working on the machine and + + align:start position:0% +um he was working on the machine and + + + align:start position:0% +um he was working on the machine and +made the machine possible + + align:start position:0% +made the machine possible + + + align:start position:0% +made the machine possible +together with scala um + + align:start position:0% + + + + align:start position:0% + +an interesting if you look at the + + align:start position:0% +an interesting if you look at the + + + align:start position:0% +an interesting if you look at the +history of those particle accelerators + + align:start position:0% +history of those particle accelerators + + + align:start position:0% +history of those particle accelerators +it's interesting to see how + + align:start position:0% +it's interesting to see how + + + align:start position:0% +it's interesting to see how +you know we made move the energy + + align:start position:0% +you know we made move the energy + + + align:start position:0% +you know we made move the energy +frontier forward so what you see in this + + align:start position:0% +frontier forward so what you see in this + + + align:start position:0% +frontier forward so what you see in this +plot here is + + align:start position:0% +plot here is + + + align:start position:0% +plot here is +the available energy of the machine and + + align:start position:0% +the available energy of the machine and + + + align:start position:0% +the available energy of the machine and +what you see here is + + align:start position:0% +what you see here is + + + align:start position:0% +what you see here is +line and this plot is called a living + + align:start position:0% +line and this plot is called a living + + + align:start position:0% +line and this plot is called a living +plot you see the logarithmic scale and + + align:start position:0% +plot you see the logarithmic scale and + + + align:start position:0% +plot you see the logarithmic scale and +you saw that for a very long time + + align:start position:0% +you saw that for a very long time + + + align:start position:0% +you saw that for a very long time +there was this logarithmic increase in + + align:start position:0% +there was this logarithmic increase in + + + align:start position:0% +there was this logarithmic increase in +available energy + + align:start position:0% +available energy + + + align:start position:0% +available energy +so this line is now turning over and + + align:start position:0% +so this line is now turning over and + + + align:start position:0% +so this line is now turning over and +we're already in 2020 + + align:start position:0% +we're already in 2020 + + + align:start position:0% +we're already in 2020 +and we haven't made any progress here so + + align:start position:0% + + + + align:start position:0% + +broke us here um there is however + + align:start position:0% +broke us here um there is however + + + align:start position:0% +broke us here um there is however +interesting discussions on + + align:start position:0% +interesting discussions on + + + align:start position:0% +interesting discussions on +going somewhere and going too high going + + align:start position:0% +going somewhere and going too high going + + + align:start position:0% +going somewhere and going too high going +somewhere here + + align:start position:0% +somewhere here + + + align:start position:0% +somewhere here +um with the next machine and being able + + align:start position:0% +um with the next machine and being able + + + align:start position:0% +um with the next machine and being able +to probe further higher energies + + align:start position:0% +to probe further higher energies + + + align:start position:0% +to probe further higher energies +and the way this is proposed for + + align:start position:0% +and the way this is proposed for + + + align:start position:0% +and the way this is proposed for +proto-important collision is by just + + align:start position:0% +proto-important collision is by just + + + align:start position:0% +proto-important collision is by just +making a structure similar to the lhc + + align:start position:0% +making a structure similar to the lhc + + + align:start position:0% +making a structure similar to the lhc +but with the radius about four times + + align:start position:0% +but with the radius about four times + + + align:start position:0% +but with the radius about four times +larger + + align:start position:0% +larger + + + align:start position:0% +larger +about 100 kilometers inc compared to the + + align:start position:0% +about 100 kilometers inc compared to the + + + align:start position:0% +about 100 kilometers inc compared to the +24 27 kilometers there that she has + + align:start position:0% +24 27 kilometers there that she has + + + align:start position:0% +24 27 kilometers there that she has +today + + align:start position:0% +today + + + align:start position:0% +today +and so you can compare this with the + + align:start position:0% +and so you can compare this with the + + + align:start position:0% +and so you can compare this with the +hutron machines but also the electron + + align:start position:0% +hutron machines but also the electron + + + align:start position:0% +hutron machines but also the electron +machines and also on the electron + + align:start position:0% +machines and also on the electron + + + align:start position:0% +machines and also on the electron +machine slide + + align:start position:0% +machine slide + + + align:start position:0% +machine slide +this this trend is not as pronounced as + + align:start position:0% +this this trend is not as pronounced as + + + align:start position:0% +this this trend is not as pronounced as +for the protein machines + + align:start position:0% +for the protein machines + + + align:start position:0% +for the protein machines +but basically here the highest energy + + align:start position:0% +but basically here the highest energy + + + align:start position:0% +but basically here the highest energy +electron positive collider is still lab + + align:start position:0% +electron positive collider is still lab + + + align:start position:0% +electron positive collider is still lab +which is being decommissioned at the end + + align:start position:0% +which is being decommissioned at the end + + + align:start position:0% +which is being decommissioned at the end +of the last century + + align:start position:0% +of the last century + + + align:start position:0% +of the last century +and we are thinking about the next + + align:start position:0% +and we are thinking about the next + + + align:start position:0% +and we are thinking about the next +machine um you know sometimes you see + + align:start position:0% +machine um you know sometimes you see + + + align:start position:0% +machine um you know sometimes you see +those acronyms + + align:start position:0% + + + + align:start position:0% + +as a linear machine international linear + + align:start position:0% +as a linear machine international linear + + + align:start position:0% +as a linear machine international linear +collider or a future circular collider + + align:start position:0% +collider or a future circular collider + + + align:start position:0% +collider or a future circular collider +with electron and positron collisions + + align:start position:0% +with electron and positron collisions + + + align:start position:0% +with electron and positron collisions +which would be host in the very same + + align:start position:0% +which would be host in the very same + + + align:start position:0% +which would be host in the very same +tunnel as this machine which is called + + align:start position:0% +tunnel as this machine which is called + + + align:start position:0% +tunnel as this machine which is called +fcc + + align:start position:0% +fcc + + + align:start position:0% +fcc +ppp or hh + + align:start position:0% + + + + align:start position:0% + +hh with 100 it's kilometer conference \ No newline at end of file diff --git a/bD0CFnI9eug.txt b/bD0CFnI9eug.txt new file mode 100644 index 0000000000000000000000000000000000000000..c046f1114c375035bf8d4eca54794495038624eb --- /dev/null +++ b/bD0CFnI9eug.txt @@ -0,0 +1,2035 @@ +align:start position:0% + +we're gonna complete our study of wkb + + align:start position:0% +we're gonna complete our study of wkb + + + align:start position:0% +we're gonna complete our study of wkb +today there's a lot of important things + + align:start position:0% +today there's a lot of important things + + + align:start position:0% +today there's a lot of important things +we haven't said yet and in particular we + + align:start position:0% +we haven't said yet and in particular we + + + align:start position:0% +we haven't said yet and in particular we +have not explained how it all works + + align:start position:0% +have not explained how it all works + + + align:start position:0% +have not explained how it all works +really in the sense of the connection + + align:start position:0% +really in the sense of the connection + + + align:start position:0% +really in the sense of the connection +formulas that's the most non-trivial + + align:start position:0% +formulas that's the most non-trivial + + + align:start position:0% +formulas that's the most non-trivial +part of the wkb story and in some ways + + align:start position:0% +part of the wkb story and in some ways + + + align:start position:0% +part of the wkb story and in some ways +is some of the most interesting things + + align:start position:0% +is some of the most interesting things + + + align:start position:0% +is some of the most interesting things +that you have to learn from this it's an + + align:start position:0% +that you have to learn from this it's an + + + align:start position:0% +that you have to learn from this it's an +opportunity to learn something about + + align:start position:0% +opportunity to learn something about + + + align:start position:0% +opportunity to learn something about +differential equation Fourier transforms + + align:start position:0% +differential equation Fourier transforms + + + align:start position:0% +differential equation Fourier transforms +and the limits of the quantities you can + + align:start position:0% +and the limits of the quantities you can + + + align:start position:0% +and the limits of the quantities you can +really compute so we will begin our + + align:start position:0% +really compute so we will begin our + + + align:start position:0% +really compute so we will begin our +discussion with some reconsideration of + + align:start position:0% +discussion with some reconsideration of + + + align:start position:0% +discussion with some reconsideration of +this airy functions you've started to + + align:start position:0% +this airy functions you've started to + + + align:start position:0% +this airy functions you've started to +hear about probably some in the homework + + align:start position:0% +hear about probably some in the homework + + + align:start position:0% +hear about probably some in the homework +some in recitation so this relates to + + align:start position:0% +some in recitation so this relates to + + + align:start position:0% +some in recitation so this relates to +this person George Biddle airy from the + + align:start position:0% +this person George Biddle airy from the + + + align:start position:0% +this person George Biddle airy from the +Airy functions who lived in England for + + align:start position:0% +Airy functions who lived in England for + + + align:start position:0% +Airy functions who lived in England for +90 years he was the seventh Royal + + align:start position:0% +90 years he was the seventh Royal + + + align:start position:0% +90 years he was the seventh Royal +astronomer and he was an astronomer from + + align:start position:0% +astronomer and he was an astronomer from + + + align:start position:0% +astronomer and he was an astronomer from +1835 to 1881 was located at his work + + align:start position:0% +1835 to 1881 was located at his work + + + align:start position:0% +1835 to 1881 was located at his work +area in Greenwich it's a little bit + + align:start position:0% +area in Greenwich it's a little bit + + + align:start position:0% +area in Greenwich it's a little bit +outside of London and that's where + + align:start position:0% +outside of London and that's where + + + align:start position:0% +outside of London and that's where +astronomers were working hard to + + align:start position:0% +astronomers were working hard to + + + align:start position:0% +astronomers were working hard to +establish all the data associated with + + align:start position:0% +establish all the data associated with + + + align:start position:0% +establish all the data associated with +the prime meridian of france also tried + + align:start position:0% +the prime meridian of france also tried + + + align:start position:0% +the prime meridian of france also tried +to made their own meridian the most + + align:start position:0% +to made their own meridian the most + + + align:start position:0% +to made their own meridian the most +important one but at the end of the day + + align:start position:0% +important one but at the end of the day + + + align:start position:0% +important one but at the end of the day +it all dependent of + + align:start position:0% +it all dependent of + + + align:start position:0% +it all dependent of +which astronomers did the most work in + + align:start position:0% +which astronomers did the most work in + + + align:start position:0% +which astronomers did the most work in +measuring precise accurate determination + + align:start position:0% +measuring precise accurate determination + + + align:start position:0% +measuring precise accurate determination +of times motion of the Moon Jupiter + + align:start position:0% +of times motion of the Moon Jupiter + + + align:start position:0% +of times motion of the Moon Jupiter +satellites all kinds of things that were + + align:start position:0% +satellites all kinds of things that were + + + align:start position:0% +satellites all kinds of things that were +pretty important at that time especially + + align:start position:0% +pretty important at that time especially + + + align:start position:0% +pretty important at that time especially +also in the manufacturing of good + + align:start position:0% +also in the manufacturing of good + + + align:start position:0% +also in the manufacturing of good +telescopes and good clocks so mr. area + + align:start position:0% +telescopes and good clocks so mr. area + + + align:start position:0% +telescopes and good clocks so mr. area +also worked in optics and that's where + + align:start position:0% +also worked in optics and that's where + + + align:start position:0% +also worked in optics and that's where +he discovered these functions were + + align:start position:0% +he discovered these functions were + + + align:start position:0% +he discovered these functions were +studied and they're very relevant to the + + align:start position:0% +studied and they're very relevant to the + + + align:start position:0% +studied and they're very relevant to the +wkb approximation so let me remind you a + + align:start position:0% +wkb approximation so let me remind you a + + + align:start position:0% +wkb approximation so let me remind you a +little of what you've been considering + + align:start position:0% +little of what you've been considering + + + align:start position:0% +little of what you've been considering +in the homework and extend some of those + + align:start position:0% +in the homework and extend some of those + + + align:start position:0% +in the homework and extend some of those +ideas as well so you considered a + + align:start position:0% +ideas as well so you considered a + + + align:start position:0% +ideas as well so you considered a +differential equation the second sigh + + align:start position:0% +differential equation the second sigh + + + align:start position:0% +differential equation the second sigh +the U squared equal u sigh pretty + + align:start position:0% +the U squared equal u sigh pretty + + + align:start position:0% +the U squared equal u sigh pretty +innocent-looking differential equation + + align:start position:0% +innocent-looking differential equation + + + align:start position:0% +innocent-looking differential equation +I'm always surprised how a differential + + align:start position:0% +I'm always surprised how a differential + + + align:start position:0% +I'm always surprised how a differential +equation that looks so simple can be so + + align:start position:0% +equation that looks so simple can be so + + + align:start position:0% +equation that looks so simple can be so +intricate but anyway it is and that's + + align:start position:0% +intricate but anyway it is and that's + + + align:start position:0% +intricate but anyway it is and that's +the area equation and it shows up for + + align:start position:0% +the area equation and it shows up for + + + align:start position:0% +the area equation and it shows up for +this problem that you have a for example + + align:start position:0% +this problem that you have a for example + + + align:start position:0% +this problem that you have a for example +an infinite wall and a potential goes up + + align:start position:0% +an infinite wall and a potential goes up + + + align:start position:0% +an infinite wall and a potential goes up +like that the bound states are + + align:start position:0% +like that the bound states are + + + align:start position:0% +like that the bound states are +controlled by solutions of this equation + + align:start position:0% +controlled by solutions of this equation + + + align:start position:0% +controlled by solutions of this equation +at the end of the day this is after you + + align:start position:0% +at the end of the day this is after you + + + align:start position:0% +at the end of the day this is after you +clean up all the units and do all the + + align:start position:0% +clean up all the units and do all the + + + align:start position:0% +clean up all the units and do all the +work but it shows in other places as + + align:start position:0% +work but it shows in other places as + + + align:start position:0% +work but it shows in other places as +well and you probably found already that + + align:start position:0% +well and you probably found already that + + + align:start position:0% +well and you probably found already that +this size functions I of U is given as a + + align:start position:0% +this size functions I of U is given as a + + + align:start position:0% +this size functions I of U is given as a +constant times an integral that came + + align:start position:0% +constant times an integral that came + + + align:start position:0% +constant times an integral that came +from three transformations of e to the I + + align:start position:0% +from three transformations of e to the I + + + align:start position:0% +from three transformations of e to the I +K cube over 3 e to the I K you + + align:start position:0% +K cube over 3 e to the I K you + + + align:start position:0% +K cube over 3 e to the I K you +and so this is our integral this is our + + align:start position:0% +and so this is our integral this is our + + + align:start position:0% +and so this is our integral this is our +solution of this equation and the nice + + align:start position:0% +solution of this equation and the nice + + + align:start position:0% +solution of this equation and the nice +thing is that this integral tells you a + + align:start position:0% +thing is that this integral tells you a + + + align:start position:0% +thing is that this integral tells you a +lot about the function it's a perfectly + + align:start position:0% +lot about the function it's a perfectly + + + align:start position:0% +lot about the function it's a perfectly +nice definition of the function you may + + align:start position:0% +nice definition of the function you may + + + align:start position:0% +nice definition of the function you may +have noticed and I think it was + + align:start position:0% +have noticed and I think it was + + + align:start position:0% +have noticed and I think it was +discussed to some degree in recitation + + align:start position:0% +discussed to some degree in recitation + + + align:start position:0% +discussed to some degree in recitation +as well that the Fourier transform + + align:start position:0% +as well that the Fourier transform + + + align:start position:0% +as well that the Fourier transform +converts this equation the first order + + align:start position:0% +converts this equation the first order + + + align:start position:0% +converts this equation the first order +differential equation because this + + align:start position:0% +differential equation because this + + + align:start position:0% +differential equation because this +becomes P squared times pi well you know + + align:start position:0% +becomes P squared times pi well you know + + + align:start position:0% +becomes P squared times pi well you know +from sharing your equations this part of + + align:start position:0% +from sharing your equations this part of + + + align:start position:0% +from sharing your equations this part of +the differential equation comes from P + + align:start position:0% +the differential equation comes from P + + + align:start position:0% +the differential equation comes from P +squared on the other hand multiplication + + align:start position:0% +squared on the other hand multiplication + + + align:start position:0% +squared on the other hand multiplication +by X is the same as DV P in Fourier + + align:start position:0% +by X is the same as DV P in Fourier + + + align:start position:0% +by X is the same as DV P in Fourier +space therefore you get a V DP of sy + + align:start position:0% +space therefore you get a V DP of sy + + + align:start position:0% +space therefore you get a V DP of sy +equal P squared sy equation and that + + align:start position:0% +equal P squared sy equation and that + + + align:start position:0% +equal P squared sy equation and that +equation is the first order differential + + align:start position:0% +equation is the first order differential + + + align:start position:0% +equation is the first order differential +equation first order differential + + align:start position:0% +equation first order differential + + + align:start position:0% +equation first order differential +equations have one solution so you would + + align:start position:0% +equations have one solution so you would + + + align:start position:0% +equations have one solution so you would +say ok I try to do this by Fourier + + align:start position:0% +say ok I try to do this by Fourier + + + align:start position:0% +say ok I try to do this by Fourier +transform and I'm getting just half of + + align:start position:0% +transform and I'm getting just half of + + + align:start position:0% +transform and I'm getting just half of +the solutions and that's true the reason + + align:start position:0% +the solutions and that's true the reason + + + align:start position:0% +the solutions and that's true the reason +is that the other solution of this + + align:start position:0% +is that the other solution of this + + + align:start position:0% +is that the other solution of this +differential equation doesn't quite have + + align:start position:0% +differential equation doesn't quite have + + + align:start position:0% +differential equation doesn't quite have +a Fourier transform so it's a little + + align:start position:0% +a Fourier transform so it's a little + + + align:start position:0% +a Fourier transform so it's a little +more difficult to get at but once you + + align:start position:0% +more difficult to get at but once you + + + align:start position:0% +more difficult to get at but once you +think of this integral it is kind of + + align:start position:0% +think of this integral it is kind of + + + align:start position:0% +think of this integral it is kind of +useful to try to be a little more + + align:start position:0% +useful to try to be a little more + + + align:start position:0% +useful to try to be a little more +general and think of it in terms of the + + align:start position:0% +general and think of it in terms of the + + + align:start position:0% +general and think of it in terms of the +complex plane the complex K plane so + + align:start position:0% +complex plane the complex K plane so + + + align:start position:0% +complex plane the complex K plane so +here is the K plane and this integral is + + align:start position:0% +here is the K plane and this integral is + + + align:start position:0% +here is the K plane and this integral is +over K from minus infinity to infinity + + align:start position:0% +over K from minus infinity to infinity + + + align:start position:0% +over K from minus infinity to infinity +so this is the standard contour of + + align:start position:0% +so this is the standard contour of + + + align:start position:0% +so this is the standard contour of +integration + + align:start position:0% + + + + align:start position:0% + +we can call it the contour c1 when + + align:start position:0% +we can call it the contour c1 when + + + align:start position:0% +we can call it the contour c1 when +you're doing this integral and you're + + align:start position:0% +you're doing this integral and you're + + + align:start position:0% +you're doing this integral and you're +doing this in the complex plane you may + + align:start position:0% +doing this in the complex plane you may + + + align:start position:0% +doing this in the complex plane you may +want to consider that if you go off the + + align:start position:0% +want to consider that if you go off the + + + align:start position:0% +want to consider that if you go off the +real line maybe things are even better + + align:start position:0% +real line maybe things are even better + + + align:start position:0% +real line maybe things are even better +in particular as you're integrating U is + + align:start position:0% +in particular as you're integrating U is + + + align:start position:0% +in particular as you're integrating U is +a fixed number it's a fixed coordinate + + align:start position:0% +a fixed number it's a fixed coordinate + + + align:start position:0% +a fixed number it's a fixed coordinate +we usually think of U as real but we + + align:start position:0% +we usually think of U as real but we + + + align:start position:0% +we usually think of U as real but we +could think of U as complex as well and + + align:start position:0% +could think of U as complex as well and + + + align:start position:0% +could think of U as complex as well and +this integral has this factor it's an + + align:start position:0% +this integral has this factor it's an + + + align:start position:0% +this integral has this factor it's an +oscillatory factor that becomes faster + + align:start position:0% +oscillatory factor that becomes faster + + + align:start position:0% +oscillatory factor that becomes faster +and faster oscillating in time but the + + align:start position:0% +and faster oscillating in time but the + + + align:start position:0% +and faster oscillating in time but the +magnitude of the integrand is 1 at every + + align:start position:0% +magnitude of the integrand is 1 at every + + + align:start position:0% +magnitude of the integrand is 1 at every +place it's oscillates very fast but the + + align:start position:0% +place it's oscillates very fast but the + + + align:start position:0% +place it's oscillates very fast but the +magnitude is 1 not the best situation + + align:start position:0% +magnitude is 1 not the best situation + + + align:start position:0% +magnitude is 1 not the best situation +possible you know it when you're doing + + align:start position:0% +possible you know it when you're doing + + + align:start position:0% +possible you know it when you're doing +that integral you have the feeling that + + align:start position:0% +that integral you have the feeling that + + + align:start position:0% +that integral you have the feeling that +eventually you get 0 because it's + + align:start position:0% +eventually you get 0 because it's + + + align:start position:0% +eventually you get 0 because it's +oscillating so fast but it would be + + align:start position:0% +oscillating so fast but it would be + + + align:start position:0% +oscillating so fast but it would be +nicer if you have a decay so for that + + align:start position:0% +nicer if you have a decay so for that + + + align:start position:0% +nicer if you have a decay so for that +consider that this function would be K + + align:start position:0% +consider that this function would be K + + + align:start position:0% +consider that this function would be K +if K if the imaginary part of K cube is + + align:start position:0% +if K if the imaginary part of K cube is + + + align:start position:0% +if K if the imaginary part of K cube is +positive became Y if the imaginary part + + align:start position:0% +positive became Y if the imaginary part + + + align:start position:0% +positive became Y if the imaginary part +of K cube is positive if you have a K + + align:start position:0% +of K cube is positive if you have a K + + + align:start position:0% +of K cube is positive if you have a K +cube would be I times a positive number + + align:start position:0% +cube would be I times a positive number + + + align:start position:0% +cube would be I times a positive number +I times I is minus 1 so you get a + + align:start position:0% +I times I is minus 1 so you get a + + + align:start position:0% +I times I is minus 1 so you get a +suppression factor if the imaginary part + + align:start position:0% +suppression factor if the imaginary part + + + align:start position:0% +suppression factor if the imaginary part +of K cube is positive so if you're + + align:start position:0% +of K cube is positive so if you're + + + align:start position:0% +of K cube is positive so if you're +integrating over a region for the + + align:start position:0% +integrating over a region for the + + + align:start position:0% +integrating over a region for the +imaginary part of K cube is positive you + + align:start position:0% +imaginary part of K cube is positive you + + + align:start position:0% +imaginary part of K cube is positive you +will be in good shape + + align:start position:0% + + + + align:start position:0% + +now if you think of K as a complex + + align:start position:0% +now if you think of K as a complex + + + align:start position:0% +now if you think of K as a complex +number e to the I theta K K cube would + + align:start position:0% +number e to the I theta K K cube would + + + align:start position:0% +number e to the I theta K K cube would +be this and the imaginary part of K cube + + align:start position:0% +be this and the imaginary part of K cube + + + align:start position:0% +be this and the imaginary part of K cube +is positive K cube is positive requires + + align:start position:0% +is positive K cube is positive requires + + + align:start position:0% +is positive K cube is positive requires +that this angle 3 I say that K be + + align:start position:0% +that this angle 3 I say that K be + + + align:start position:0% +that this angle 3 I say that K be +between PI and 0 why because if you have + + align:start position:0% +between PI and 0 why because if you have + + + align:start position:0% +between PI and 0 why because if you have +a complex number any complex number its + + align:start position:0% +a complex number any complex number its + + + align:start position:0% +a complex number any complex number its +imaginary part is positive if the + + align:start position:0% +imaginary part is positive if the + + + align:start position:0% +imaginary part is positive if the +argument of that angle goes between 0 + + align:start position:0% +argument of that angle goes between 0 + + + align:start position:0% +argument of that angle goes between 0 +and pi moreover if you get an imaginary + + align:start position:0% +and pi moreover if you get an imaginary + + + align:start position:0% +and pi moreover if you get an imaginary +part positive for some angle theta k if + + align:start position:0% +part positive for some angle theta k if + + + align:start position:0% +part positive for some angle theta k if +in of K cube is positive for some theta + + align:start position:0% +in of K cube is positive for some theta + + + align:start position:0% +in of K cube is positive for some theta +K it is also positive for fated k plus 2 + + align:start position:0% +K it is also positive for fated k plus 2 + + + align:start position:0% +K it is also positive for fated k plus 2 +pi over 3 because if you add 2 pi over 3 + + align:start position:0% +pi over 3 because if you add 2 pi over 3 + + + align:start position:0% +pi over 3 because if you add 2 pi over 3 +to take the k you change this by 2 pi + + align:start position:0% +to take the k you change this by 2 pi + + + align:start position:0% +to take the k you change this by 2 pi +and therefore the exponential doesn't + + align:start position:0% +and therefore the exponential doesn't + + + align:start position:0% +and therefore the exponential doesn't +change from this inequality i'm sorry i + + align:start position:0% +change from this inequality i'm sorry i + + + align:start position:0% +change from this inequality i'm sorry i +have an eye too many here the imaginary + + align:start position:0% +have an eye too many here the imaginary + + + align:start position:0% +have an eye too many here the imaginary +part of this requires that the argument + + align:start position:0% +part of this requires that the argument + + + align:start position:0% +part of this requires that the argument +of this be between 0 and pi or theta K + + align:start position:0% +of this be between 0 and pi or theta K + + + align:start position:0% +of this be between 0 and pi or theta K +between PI over 3 and 0 so actually here + + align:start position:0% +between PI over 3 and 0 so actually here + + + align:start position:0% +between PI over 3 and 0 so actually here +I + + align:start position:0% +I + + + align:start position:0% +I +should draw 0 to pi over 3 this is at 60 + + align:start position:0% +should draw 0 to pi over 3 this is at 60 + + + align:start position:0% +should draw 0 to pi over 3 this is at 60 +degrees and that the region in k-space + + align:start position:0% +degrees and that the region in k-space + + + align:start position:0% +degrees and that the region in k-space +where the integral is suppressed now we + + align:start position:0% +where the integral is suppressed now we + + + align:start position:0% +where the integral is suppressed now we +also said that this region is unchanged + + align:start position:0% +also said that this region is unchanged + + + align:start position:0% +also said that this region is unchanged +if you add 2 pi over 3 so if I add 2 pi + + align:start position:0% +if you add 2 pi over 3 so if I add 2 pi + + + align:start position:0% +if you add 2 pi over 3 so if I add 2 pi +over 3 that's precisely one third of a + + align:start position:0% +over 3 that's precisely one third of a + + + align:start position:0% +over 3 that's precisely one third of a +turn this this is 30 degrees it goes + + align:start position:0% +turn this this is 30 degrees it goes + + + align:start position:0% +turn this this is 30 degrees it goes +this area into this and finally if I add + + align:start position:0% +this area into this and finally if I add + + + align:start position:0% +this area into this and finally if I add +again 2 PI over 3 + + align:start position:0% +again 2 PI over 3 + + + align:start position:0% +again 2 PI over 3 +it goes into 30 30 30 and to this region + + align:start position:0% +it goes into 30 30 30 and to this region + + + align:start position:0% +it goes into 30 30 30 and to this region +I guess the sign of nuclear material + + align:start position:0% +I guess the sign of nuclear material + + + align:start position:0% +I guess the sign of nuclear material +hazardous materials something like that + + align:start position:0% +hazardous materials something like that + + + align:start position:0% +hazardous materials something like that +it's not hazardous or health will + + align:start position:0% +it's not hazardous or health will + + + align:start position:0% +it's not hazardous or health will +survive this lecture so what's happening + + align:start position:0% +survive this lecture so what's happening + + + align:start position:0% +survive this lecture so what's happening +here actually is something quite + + align:start position:0% +here actually is something quite + + + align:start position:0% +here actually is something quite +interesting for example you're doing + + align:start position:0% +interesting for example you're doing + + + align:start position:0% +interesting for example you're doing +this integral here if you started doing + + align:start position:0% +this integral here if you started doing + + + align:start position:0% +this integral here if you started doing +this in turn once you're far far away + + align:start position:0% +this in turn once you're far far away + + + align:start position:0% +this in turn once you're far far away +you start going up the integral over + + align:start position:0% +you start going up the integral over + + + align:start position:0% +you start going up the integral over +here is going to give nothing because + + align:start position:0% +here is going to give nothing because + + + align:start position:0% +here is going to give nothing because +you are very far away and therefore + + align:start position:0% +you are very far away and therefore + + + align:start position:0% +you are very far away and therefore +you're in the region of absolute + + align:start position:0% +you're in the region of absolute + + + align:start position:0% +you're in the region of absolute +exponential suppression we said this + + align:start position:0% +exponential suppression we said this + + + align:start position:0% +exponential suppression we said this +thing is has a positive imaginary part + + align:start position:0% +thing is has a positive imaginary part + + + align:start position:0% +thing is has a positive imaginary part +and therefore you have + + align:start position:0% +and therefore you have + + + align:start position:0% +and therefore you have +suppression is K cubed so it's becoming + + align:start position:0% +suppression is K cubed so it's becoming + + + align:start position:0% +suppression is K cubed so it's becoming +like e to the - radius cube is killed so + + align:start position:0% +like e to the - radius cube is killed so + + + align:start position:0% +like e to the - radius cube is killed so +there's no problem to go up here and you + + align:start position:0% +there's no problem to go up here and you + + + align:start position:0% +there's no problem to go up here and you +get nothing so what it means is that + + align:start position:0% +get nothing so what it means is that + + + align:start position:0% +get nothing so what it means is that +actually there's no singularities in the + + align:start position:0% +actually there's no singularities in the + + + align:start position:0% +actually there's no singularities in the +integrand either this integral that + + align:start position:0% +integrand either this integral that + + + align:start position:0% +integrand either this integral that +we've done here could have been done + + align:start position:0% +we've done here could have been done + + + align:start position:0% +we've done here could have been done +over this contour like that and then you + + align:start position:0% +over this contour like that and then you + + + align:start position:0% +over this contour like that and then you +could have gone like that you can do it + + align:start position:0% +could have gone like that you can do it + + + align:start position:0% +could have gone like that you can do it +mathematically answer will be the same + + align:start position:0% +mathematically answer will be the same + + + align:start position:0% +mathematically answer will be the same +or you could have gone like that or you + + align:start position:0% +or you could have gone like that or you + + + align:start position:0% +or you could have gone like that or you +could have done here like this also + + align:start position:0% +could have done here like this also + + + align:start position:0% +could have done here like this also +you're suppressed over here and you're + + align:start position:0% +you're suppressed over here and you're + + + align:start position:0% +you're suppressed over here and you're +suppressed over here and actually by + + align:start position:0% +suppressed over here and actually by + + + align:start position:0% +suppressed over here and actually by +counter deformation you could instead of + + align:start position:0% +counter deformation you could instead of + + + align:start position:0% +counter deformation you could instead of +doing this interview could have done + + align:start position:0% +doing this interview could have done + + + align:start position:0% +doing this interview could have done +here and gone up like that and done that + + align:start position:0% +here and gone up like that and done that + + + align:start position:0% +here and gone up like that and done that +that also would have been the same + + align:start position:0% +that also would have been the same + + + align:start position:0% +that also would have been the same +result there's nothing the integrand is + + align:start position:0% +result there's nothing the integrand is + + + align:start position:0% +result there's nothing the integrand is +analytic here so this you can push it + + align:start position:0% +analytic here so this you can push it + + + align:start position:0% +analytic here so this you can push it +down and nothing goes wrong or you could + + align:start position:0% +down and nothing goes wrong or you could + + + align:start position:0% +down and nothing goes wrong or you could +have done even this integral like that + + align:start position:0% + + + + align:start position:0% + +because the integral here is zero and + + align:start position:0% +because the integral here is zero and + + + align:start position:0% +because the integral here is zero and +the integral here is zero so you can in + + align:start position:0% +the integral here is zero so you can in + + + align:start position:0% +the integral here is zero so you can in +fact if you did this if it was + + align:start position:0% +fact if you did this if it was + + + align:start position:0% +fact if you did this if it was +Mathematica Mathematica when you try to + + align:start position:0% +Mathematica Mathematica when you try to + + + align:start position:0% +Mathematica Mathematica when you try to +do this integral kind of that's it but + + align:start position:0% +do this integral kind of that's it but + + + align:start position:0% +do this integral kind of that's it but +it complains a little it's worried that + + align:start position:0% +it complains a little it's worried that + + + align:start position:0% +it complains a little it's worried that +you know it's not getting the answer + + align:start position:0% +you know it's not getting the answer + + + align:start position:0% +you know it's not getting the answer +right because it's still the integrand + + align:start position:0% +right because it's still the integrand + + + align:start position:0% +right because it's still the integrand +is still big it's oscillating very fast + + align:start position:0% +is still big it's oscillating very fast + + + align:start position:0% +is still big it's oscillating very fast +but it's big if you go here I think + + align:start position:0% +but it's big if you go here I think + + + align:start position:0% +but it's big if you go here I think +Mathematica will complain less and will + + align:start position:0% +Mathematica will complain less and will + + + align:start position:0% +Mathematica will complain less and will +give you the same answer so this is the + + align:start position:0% +give you the same answer so this is the + + + align:start position:0% +give you the same answer so this is the +power of complex analysis that allows + + align:start position:0% +power of complex analysis that allows + + + align:start position:0% +power of complex analysis that allows +you to do this integral in all kinds of + + align:start position:0% +you to do this integral in all kinds of + + + align:start position:0% +you to do this integral in all kinds of +ways and and there's something more even + + align:start position:0% +ways and and there's something more even + + + align:start position:0% +ways and and there's something more even +more important about this that I will + + align:start position:0% +more important about this that I will + + + align:start position:0% +more important about this that I will +explain the notes but I can convey the + + align:start position:0% +explain the notes but I can convey the + + + align:start position:0% +explain the notes but I can convey the +idea here when you prove that this is a + + align:start position:0% +idea here when you prove that this is a + + + align:start position:0% +idea here when you prove that this is a +solution and when you went to Fourier + + align:start position:0% +solution and when you went to Fourier + + + align:start position:0% +solution and when you went to Fourier +space you had to do an integration by + + align:start position:0% +space you had to do an integration by + + + align:start position:0% +space you had to do an integration by +parts and an integration by parts is + + align:start position:0% +parts and an integration by parts is + + + align:start position:0% +parts and an integration by parts is +always dangerous and if you're trying to + + align:start position:0% +always dangerous and if you're trying to + + + align:start position:0% +always dangerous and if you're trying to +find out real a true solution of your + + align:start position:0% +find out real a true solution of your + + + align:start position:0% +find out real a true solution of your +problem you have to make sure it works P + + align:start position:0% +problem you have to make sure it works P + + + align:start position:0% +problem you have to make sure it works P +the operator P is supposed to be + + align:start position:0% +the operator P is supposed to be + + + align:start position:0% +the operator P is supposed to be +hermitian and here what happens is that + + align:start position:0% +hermitian and here what happens is that + + + align:start position:0% +hermitian and here what happens is that +you turn this into DDP and you have to + + align:start position:0% +you turn this into DDP and you have to + + + align:start position:0% +you turn this into DDP and you have to +fall back this factor and here is where + + align:start position:0% +fall back this factor and here is where + + + align:start position:0% +fall back this factor and here is where +this discussion is very relevant because + + align:start position:0% +this discussion is very relevant because + + + align:start position:0% +this discussion is very relevant because +when you fold out this factor you have + + align:start position:0% +when you fold out this factor you have + + + align:start position:0% +when you fold out this factor you have +to integrate you can get contributions + + align:start position:0% +to integrate you can get contributions + + + align:start position:0% +to integrate you can get contributions +from the boundary and you have to make + + align:start position:0% +from the boundary and you have to make + + + align:start position:0% +from the boundary and you have to make +sure those contributions are zero + + align:start position:0% +sure those contributions are zero + + + align:start position:0% +sure those contributions are zero +otherwise you're not solving the + + align:start position:0% +otherwise you're not solving the + + + align:start position:0% +otherwise you're not solving the +differential equation really and the + + align:start position:0% +differential equation really and the + + + align:start position:0% +differential equation really and the +happy thing about these counters and now + + align:start position:0% +happy thing about these counters and now + + + align:start position:0% +happy thing about these counters and now +that you understand this regions is that + + align:start position:0% +that you understand this regions is that + + + align:start position:0% +that you understand this regions is that +yes the boundary contributions are going + + align:start position:0% +yes the boundary contributions are going + + + align:start position:0% +yes the boundary contributions are going +to be zero from the two sides because of + + align:start position:0% +to be zero from the two sides because of + + + align:start position:0% +to be zero from the two sides because of +this suppression factor so this analysis + + align:start position:0% +this suppression factor so this analysis + + + align:start position:0% +this suppression factor so this analysis +actually turns it into a rigorous + + align:start position:0% +actually turns it into a rigorous + + + align:start position:0% +actually turns it into a rigorous +analysis and the the part that has to do + + align:start position:0% +analysis and the the part that has to do + + + align:start position:0% +analysis and the the part that has to do +with the boundary conditions that the + + align:start position:0% +with the boundary conditions that the + + + align:start position:0% +with the boundary conditions that the +fact that the operations that you're + + align:start position:0% +fact that the operations that you're + + + align:start position:0% +fact that the operations that you're +doing are legal when you try to solve + + align:start position:0% +doing are legal when you try to solve + + + align:start position:0% +doing are legal when you try to solve +the differential equation require this + + align:start position:0% +the differential equation require this + + + align:start position:0% +the differential equation require this +is the details that I will not derive + + align:start position:0% +is the details that I will not derive + + + align:start position:0% +is the details that I will not derive +now require precisely that e to the I K + + align:start position:0% +now require precisely that e to the I K + + + align:start position:0% +now require precisely that e to the I K +cube over 3 e to the I can you vanish at + + align:start position:0% +cube over 3 e to the I can you vanish at + + + align:start position:0% +cube over 3 e to the I can you vanish at +the end of the counter gamma that you're + + align:start position:0% +the end of the counter gamma that you're + + + align:start position:0% +the end of the counter gamma that you're +using to solve the problem so if you're + + align:start position:0% +using to solve the problem so if you're + + + align:start position:0% +using to solve the problem so if you're +in the way from here to here it should + + align:start position:0% +in the way from here to here it should + + + align:start position:0% +in the way from here to here it should +vanish at this end and at that end + + align:start position:0% +vanish at this end and at that end + + + align:start position:0% +vanish at this end and at that end +rigorously speaking this thing only + + align:start position:0% +rigorously speaking this thing only + + + align:start position:0% +rigorously speaking this thing only +vanishes if you're a little bit up but + + align:start position:0% +vanishes if you're a little bit up but + + + align:start position:0% +vanishes if you're a little bit up but +this is what you really need for the + + align:start position:0% +this is what you really need for the + + + align:start position:0% +this is what you really need for the +equation to be a solution \ No newline at end of file diff --git a/bEpq3yjismU.txt b/bEpq3yjismU.txt new file mode 100644 index 0000000000000000000000000000000000000000..081edf96318a4c2e401483091aa856e4248ded68 --- /dev/null +++ b/bEpq3yjismU.txt @@ -0,0 +1,1059 @@ +align:start position:0% + +let's consider a ball that is dropped + + align:start position:0% +let's consider a ball that is dropped + + + align:start position:0% +let's consider a ball that is dropped +from a certain height hi above the + + align:start position:0% +from a certain height hi above the + + + align:start position:0% +from a certain height hi above the +ground and this ball is falling it hits + + align:start position:0% +ground and this ball is falling it hits + + + align:start position:0% +ground and this ball is falling it hits +the ground and it bounces up until it + + align:start position:0% +the ground and it bounces up until it + + + align:start position:0% +the ground and it bounces up until it +reaches some final height + + align:start position:0% +reaches some final height + + + align:start position:0% +reaches some final height +hfal now when the ball is colliding with + + align:start position:0% +hfal now when the ball is colliding with + + + align:start position:0% +hfal now when the ball is colliding with +the ground there are Collision forces + + align:start position:0% +the ground there are Collision forces + + + align:start position:0% +the ground there are Collision forces +and in this problem what we'd like to do + + align:start position:0% +and in this problem what we'd like to do + + + align:start position:0% +and in this problem what we'd like to do +is figure out what the average force of + + align:start position:0% +is figure out what the average force of + + + align:start position:0% +is figure out what the average force of +the ground is on the ball so we'd like + + align:start position:0% +the ground is on the ball so we'd like + + + align:start position:0% +the ground is on the ball so we'd like +to find the and that will be the normal + + align:start position:0% +to find the and that will be the normal + + + align:start position:0% +to find the and that will be the normal +force the average normal force on the + + align:start position:0% +force the average normal force on the + + + align:start position:0% +force the average normal force on the +ball during the Collision now if we look + + align:start position:0% +ball during the Collision now if we look + + + align:start position:0% +ball during the Collision now if we look +at this ball dropping it's going to lose + + align:start position:0% +at this ball dropping it's going to lose + + + align:start position:0% +at this ball dropping it's going to lose +a little bit of energy because it's + + align:start position:0% +a little bit of energy because it's + + + align:start position:0% +a little bit of energy because it's +getting compressed at the Collision + + align:start position:0% +getting compressed at the Collision + + + align:start position:0% +getting compressed at the Collision +let's look at an example of the actual + + align:start position:0% +let's look at an example of the actual + + + align:start position:0% +let's look at an example of the actual +ball dropping as you can see in this + + align:start position:0% +ball dropping as you can see in this + + + align:start position:0% +ball dropping as you can see in this +high-speed video as the ball falls down + + align:start position:0% +high-speed video as the ball falls down + + + align:start position:0% +high-speed video as the ball falls down +it cover collides with the ground when + + align:start position:0% +it cover collides with the ground when + + + align:start position:0% +it cover collides with the ground when +it collides with the ground it's + + align:start position:0% +it collides with the ground it's + + + align:start position:0% +it collides with the ground it's +compressed and then as it rebounds + + align:start position:0% +compressed and then as it rebounds + + + align:start position:0% +compressed and then as it rebounds +upwards the ball expands back to its + + align:start position:0% +upwards the ball expands back to its + + + align:start position:0% +upwards the ball expands back to its +original shape but it doesn't quite get + + align:start position:0% +original shape but it doesn't quite get + + + align:start position:0% +original shape but it doesn't quite get +to the same height that's because when + + align:start position:0% +to the same height that's because when + + + align:start position:0% +to the same height that's because when +the ball is compressed there's some + + align:start position:0% +the ball is compressed there's some + + + align:start position:0% +the ball is compressed there's some +deoration in the rubber structure of the + + align:start position:0% +deoration in the rubber structure of the + + + align:start position:0% +deoration in the rubber structure of the +balll and it's not a completely elastic + + align:start position:0% +balll and it's not a completely elastic + + + align:start position:0% +balll and it's not a completely elastic +deformation and so some of the energy is + + align:start position:0% +deformation and so some of the energy is + + + align:start position:0% +deformation and so some of the energy is +transformed into first different + + align:start position:0% +transformed into first different + + + align:start position:0% +transformed into first different +molecular motions which turn into + + align:start position:0% +molecular motions which turn into + + + align:start position:0% +molecular motions which turn into +thermal energy that's radiated into the + + align:start position:0% +thermal energy that's radiated into the + + + align:start position:0% +thermal energy that's radiated into the +environment let's look in particular at + + align:start position:0% +environment let's look in particular at + + + align:start position:0% +environment let's look in particular at +the details of the Collision if we look + + align:start position:0% +the details of the Collision if we look + + + align:start position:0% +the details of the Collision if we look +at it in slow motion what we have here + + align:start position:0% +at it in slow motion what we have here + + + align:start position:0% +at it in slow motion what we have here +and I'll draw a picture as the ball is + + align:start position:0% +and I'll draw a picture as the ball is + + + align:start position:0% +and I'll draw a picture as the ball is +colliding with the ground the ball + + align:start position:0% +colliding with the ground the ball + + + align:start position:0% +colliding with the ground the ball +compresses expands as it goes upwards + + align:start position:0% +compresses expands as it goes upwards + + + align:start position:0% +compresses expands as it goes upwards +and so we can draw a free body diagram + + align:start position:0% +and so we can draw a free body diagram + + + align:start position:0% +and so we can draw a free body diagram +on the ball with a normal force and a + + align:start position:0% +on the ball with a normal force and a + + + align:start position:0% +on the ball with a normal force and a +gravitational force now let's choose our + + align:start position:0% +gravitational force now let's choose our + + + align:start position:0% +gravitational force now let's choose our +positive direction + + align:start position:0% +positive direction + + + align:start position:0% +positive direction +up so now what we like to do is apply + + align:start position:0% +up so now what we like to do is apply + + + align:start position:0% +up so now what we like to do is apply +the momentum principle to analyze the + + align:start position:0% +the momentum principle to analyze the + + + align:start position:0% +the momentum principle to analyze the +average normal force and our momentum + + align:start position:0% +average normal force and our momentum + + + align:start position:0% +average normal force and our momentum +principle remember is + + align:start position:0% +principle remember is + + + align:start position:0% +principle remember is +impulse the force integrated over some + + align:start position:0% +impulse the force integrated over some + + + align:start position:0% +impulse the force integrated over some +time during the Collision is equal to + + align:start position:0% +time during the Collision is equal to + + + align:start position:0% +time during the Collision is equal to +the change in momentum so what we'd like + + align:start position:0% +the change in momentum so what we'd like + + + align:start position:0% +the change in momentum so what we'd like +to do is identify the states that are + + align:start position:0% +to do is identify the states that are + + + align:start position:0% +to do is identify the states that are +relevant so we'll have a state before so + + align:start position:0% +relevant so we'll have a state before so + + + align:start position:0% +relevant so we'll have a state before so +what we'll do is we'll call this the + + align:start position:0% +what we'll do is we'll call this the + + + align:start position:0% +what we'll do is we'll call this the +before + + align:start position:0% +before + + + align:start position:0% +before +State and that's right before the ball + + align:start position:0% +State and that's right before the ball + + + align:start position:0% +State and that's right before the ball +is hitting the ground and we have an + + align:start position:0% +is hitting the ground and we have an + + + align:start position:0% +is hitting the ground and we have an +after + + align:start position:0% + + + + align:start position:0% + +State and in the after State the ball + + align:start position:0% +State and in the after State the ball + + + align:start position:0% +State and in the after State the ball +has now finished colliding with the + + align:start position:0% +has now finished colliding with the + + + align:start position:0% +has now finished colliding with the +ground and it's now moving up with speed + + align:start position:0% +ground and it's now moving up with speed + + + align:start position:0% +ground and it's now moving up with speed +up now again we're going to choose + + align:start position:0% +up now again we're going to choose + + + align:start position:0% +up now again we're going to choose +positive up here I'm representing things + + align:start position:0% +positive up here I'm representing things + + + align:start position:0% +positive up here I'm representing things +as + + align:start position:0% +as + + + align:start position:0% +as +speeds + + align:start position:0% +speeds + + + align:start position:0% +speeds +um one of the things we need some times + + align:start position:0% +um one of the things we need some times + + + align:start position:0% +um one of the things we need some times +here + + align:start position:0% +here + + + align:start position:0% +here +so let's say that a t initial is zero + + align:start position:0% +so let's say that a t initial is zero + + + align:start position:0% +so let's say that a t initial is zero +this is our final time we'll call this + + align:start position:0% +this is our final time we'll call this + + + align:start position:0% +this is our final time we'll call this +time the before time we'll just call + + align:start position:0% +time the before time we'll just call + + + align:start position:0% +time the before time we'll just call +this T before and this is T after and + + align:start position:0% +this T before and this is T after and + + + align:start position:0% +this T before and this is T after and +then our integral is going from before + + align:start position:0% +then our integral is going from before + + + align:start position:0% +then our integral is going from before +to after of the momentum and we can now + + align:start position:0% +to after of the momentum and we can now + + + align:start position:0% +to after of the momentum and we can now +apply the momentum principle well this + + align:start position:0% +apply the momentum principle well this + + + align:start position:0% +apply the momentum principle well this +is a vector equation and we've chosen + + align:start position:0% +is a vector equation and we've chosen + + + align:start position:0% +is a vector equation and we've chosen +unit vectors up so what we have here is + + align:start position:0% +unit vectors up so what we have here is + + + align:start position:0% +unit vectors up so what we have here is +the integral of from T before to T after + + align:start position:0% +the integral of from T before to T after + + + align:start position:0% +the integral of from T before to T after +of n minus mg integrated over DT and + + align:start position:0% +of n minus mg integrated over DT and + + + align:start position:0% +of n minus mg integrated over DT and +that's equal to the momentum at the Y + + align:start position:0% +that's equal to the momentum at the Y + + + align:start position:0% +that's equal to the momentum at the Y +component of the momentum at T after + + align:start position:0% +component of the momentum at T after + + + align:start position:0% +component of the momentum at T after +minus the Y component of the momentum we + + align:start position:0% +minus the Y component of the momentum we + + + align:start position:0% +minus the Y component of the momentum we +don't have a vector here anymore the Y + + align:start position:0% +don't have a vector here anymore the Y + + + align:start position:0% +don't have a vector here anymore the Y +component of the vector T before and so + + align:start position:0% +component of the vector T before and so + + + align:start position:0% +component of the vector T before and so +this is our expression of the momentum + + align:start position:0% +this is our expression of the momentum + + + align:start position:0% +this is our expression of the momentum +principle impulse causes momentum to + + align:start position:0% +principle impulse causes momentum to + + + align:start position:0% +principle impulse causes momentum to +change now we're assuming that the + + align:start position:0% +change now we're assuming that the + + + align:start position:0% +change now we're assuming that the +normal force + + align:start position:0% +normal force + + + align:start position:0% +normal force +is just averaging it and so the cgal + + align:start position:0% +is just averaging it and so the cgal + + + align:start position:0% +is just averaging it and so the cgal +simply becomes + + align:start position:0% +simply becomes + + + align:start position:0% +simply becomes +n + + align:start position:0% +n + + + align:start position:0% +n +average minus + + align:start position:0% +average minus + + + align:start position:0% +average minus +mg times the time of collision is equal + + align:start position:0% +mg times the time of collision is equal + + + align:start position:0% +mg times the time of collision is equal +to now in here we can put the mass of + + align:start position:0% +to now in here we can put the mass of + + + align:start position:0% +to now in here we can put the mass of +the ball we have the Velocity now here's + + align:start position:0% +the ball we have the Velocity now here's + + + align:start position:0% +the ball we have the Velocity now here's +where we have to be a little bit careful + + align:start position:0% +where we have to be a little bit careful + + + align:start position:0% +where we have to be a little bit careful +because we're looking at the Y component + + align:start position:0% +because we're looking at the Y component + + + align:start position:0% +because we're looking at the Y component +we chose speed downwards that's in the + + align:start position:0% +we chose speed downwards that's in the + + + align:start position:0% +we chose speed downwards that's in the +negative y direction so we have minus + + align:start position:0% +negative y direction so we have minus + + + align:start position:0% +negative y direction so we have minus +sorry we're looking at the after we have + + align:start position:0% +sorry we're looking at the after we have + + + align:start position:0% +sorry we're looking at the after we have +plus the after because this is going in + + align:start position:0% +plus the after because this is going in + + + align:start position:0% +plus the after because this is going in +the positive jhat + + align:start position:0% +the positive jhat + + + align:start position:0% +the positive jhat +direction and over here we have + + align:start position:0% +direction and over here we have + + + align:start position:0% +direction and over here we have +negative + + align:start position:0% +negative + + + align:start position:0% +negative +Mass but it's going in the minus + + align:start position:0% +Mass but it's going in the minus + + + align:start position:0% +Mass but it's going in the minus +Direction so we have minus m v before + + align:start position:0% +Direction so we have minus m v before + + + align:start position:0% +Direction so we have minus m v before +and so we get Mass * V after plus v + + align:start position:0% +and so we get Mass * V after plus v + + + align:start position:0% +and so we get Mass * V after plus v +before + + align:start position:0% +before + + + align:start position:0% +before +so our first result is that the normal + + align:start position:0% +so our first result is that the normal + + + align:start position:0% +so our first result is that the normal +force average let's bring the Divide + + align:start position:0% +force average let's bring the Divide + + + align:start position:0% +force average let's bring the Divide +through by delta T and bring the mg term + + align:start position:0% +through by delta T and bring the mg term + + + align:start position:0% +through by delta T and bring the mg term +over so we have + + align:start position:0% +over so we have + + + align:start position:0% +over so we have +MV plus VB divided by delta T plus + + align:start position:0% +MV plus VB divided by delta T plus + + + align:start position:0% +MV plus VB divided by delta T plus +mg so we see that if the Collision time + + align:start position:0% +mg so we see that if the Collision time + + + align:start position:0% +mg so we see that if the Collision time +is very short then this average force is + + align:start position:0% +is very short then this average force is + + + align:start position:0% +is very short then this average force is +a little bit bigger a long Collision + + align:start position:0% +a little bit bigger a long Collision + + + align:start position:0% +a little bit bigger a long Collision +time time the average force a little bit + + align:start position:0% +time time the average force a little bit + + + align:start position:0% +time time the average force a little bit +smaller now from kinematics we already + + align:start position:0% +smaller now from kinematics we already + + + align:start position:0% +smaller now from kinematics we already +have worked out the problem that the + + align:start position:0% +have worked out the problem that the + + + align:start position:0% +have worked out the problem that the +speed for an object that rises to a + + align:start position:0% +speed for an object that rises to a + + + align:start position:0% +speed for an object that rises to a +height H final this is the velocity + + align:start position:0% +height H final this is the velocity + + + align:start position:0% +height H final this is the velocity +afterwards is just square root of 2G + + align:start position:0% +afterwards is just square root of 2G + + + align:start position:0% +afterwards is just square root of 2G +hfal and in a similar way if an object + + align:start position:0% +hfal and in a similar way if an object + + + align:start position:0% +hfal and in a similar way if an object +is falling a height + + align:start position:0% +is falling a height + + + align:start position:0% +is falling a height +hi the speed when it gets to the bottom + + align:start position:0% +hi the speed when it gets to the bottom + + + align:start position:0% +hi the speed when it gets to the bottom +is 2 + + align:start position:0% +is 2 + + + align:start position:0% +is 2 +ghi and so now we can conclude with + + align:start position:0% +ghi and so now we can conclude with + + + align:start position:0% +ghi and so now we can conclude with +these substitutions + + align:start position:0% +these substitutions + + + align:start position:0% +these substitutions +that the average force equals m * < TK + + align:start position:0% +that the average force equals m * < TK + + + align:start position:0% +that the average force equals m * < TK +of 2G hfal plus Square < TK of 2G H + + align:start position:0% +of 2G hfal plus Square < TK of 2G H + + + align:start position:0% +of 2G hfal plus Square < TK of 2G H +initial over the Collision time plus + + align:start position:0% +initial over the Collision time plus + + + align:start position:0% +initial over the Collision time plus +mg and of course the Collision time + + align:start position:0% +mg and of course the Collision time + + + align:start position:0% +mg and of course the Collision time +we're saying is T after minus t before + + align:start position:0% +we're saying is T after minus t before + + + align:start position:0% +we're saying is T after minus t before +and so that's how we can use the + + align:start position:0% +and so that's how we can use the + + + align:start position:0% +and so that's how we can use the +momentum principle to get an average + + align:start position:0% +momentum principle to get an average + + + align:start position:0% +momentum principle to get an average +expression for the normal force \ No newline at end of file diff --git a/bHocXJ4rv5g.txt b/bHocXJ4rv5g.txt new file mode 100644 index 0000000000000000000000000000000000000000..5061a6dfe061007bc2d034f0b32af9c6549947d3 --- /dev/null +++ b/bHocXJ4rv5g.txt @@ -0,0 +1,99 @@ +align:start position:0% + +so the last question we can ask us is + + align:start position:0% +so the last question we can ask us is + + + align:start position:0% +so the last question we can ask us is +what was that V not here the initially + + align:start position:0% +what was that V not here the initially + + + align:start position:0% +what was that V not here the initially +of the sled making use of the fact that + + align:start position:0% +of the sled making use of the fact that + + + align:start position:0% +of the sled making use of the fact that +the sled comes to stop at the time that + + align:start position:0% +the sled comes to stop at the time that + + + align:start position:0% +the sled comes to stop at the time that +the fuel is all used up that means that + + align:start position:0% +the fuel is all used up that means that + + + align:start position:0% +the fuel is all used up that means that +our final velocity here zero will bring + + align:start position:0% +our final velocity here zero will bring + + + align:start position:0% +our final velocity here zero will bring +V nought to the other side and then we + + align:start position:0% +V nought to the other side and then we + + + align:start position:0% +V nought to the other side and then we +get minus u ln and the rocket may us by + + align:start position:0% +get minus u ln and the rocket may us by + + + align:start position:0% +get minus u ln and the rocket may us by +then it's just the dry mass M naught + + align:start position:0% +then it's just the dry mass M naught + + + align:start position:0% +then it's just the dry mass M naught +over 2 M naught and that of course + + align:start position:0% +over 2 M naught and that of course + + + align:start position:0% +over 2 M naught and that of course +cancels out here and we can say that is + + align:start position:0% +cancels out here and we can say that is + + + align:start position:0% +cancels out here and we can say that is +plus u ln of 2 so that was the velocity + + align:start position:0% +plus u ln of 2 so that was the velocity + + + align:start position:0% +plus u ln of 2 so that was the velocity +that the sled was going with \ No newline at end of file diff --git a/bihrpOS0qtY.txt b/bihrpOS0qtY.txt new file mode 100644 index 0000000000000000000000000000000000000000..36ca4687045f8dae4236a7ed2edc3c8be898b070 --- /dev/null +++ b/bihrpOS0qtY.txt @@ -0,0 +1,4634 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Good afternoon. + +Good afternoon. + +I want to remind you that +a week from today + +is the second exam. + +The format is identical to +what you had, 50 multiple + +choice questions; 30 from the +book, Chapters 5 to 7; 20 from + +Sacks and the lectures; +short answers. + +So talking about tests, +why do we have tests? + +You live in a world of tests. + +Everything from SATs to, on your +horizons, maybe GREs or + +MCATs or LSATs. + +So why do people have tests, +besides making it miserable to + +be under 30? + +It's the revenge of +the older people. + +Why do people have tests? + +Yeah? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: One of them +is just verify + +that you know something. + +And people will call it sort +of have you learned stuff? + +And the test is meant +to be an estimate of + +what have you learned? + +But a second form of testing, +what people sometimes will + +call high-stakes tests in a +slightly different way, are + +ones about selection and +prediction, which sometimes + +involve achievement or +aptitude, things + +like SATs or GREs. + +So achievements are meant to be +estimates of what you know, + +advanced placement tests, how +much math you know or physics. + +Content in a given area. + +And sort of a broader sense +of aptitude, SATs or GREs. + +Now, one thing that's different +about today's + +lecture on intelligence, it'll +be a little similar when we do + +personalities, up until now, to +a first approximation, most + +of the time we've talked about +what we view as general + +principles of the human mind +and brain across everybody. + +How vision works across +everybody, memory across + +everybody, thinking +across everybody. + +And now, we're switching +to a domain. + +And it doesn't have to be this +way, but this is the way the + +world has done it, where +we emphasized + +differences between people. + +So when people take tests, it's +not to see that everybody + +took the test. + +What they're going to do is, you +get an A, or a B, or a C, + +or you get a high SAT or a +medium SAT, and schools use + +the differences to +think about you. + +And so one question is, from an +empirical sense, are these + +tests pretty good at +predicting things? + +And the answer is +they're decent. + +They're not terrific. + +So the tests survive, like SATs +or GREs, because there's + +correlations between these kinds +of tests before you get + +to graduate school for example, +and how faculty rates + +students or how productive +people are in terms of + +research or as a graduate +student in this case, or the + +GPAs, or things like that. + +And the correlations are +about 0.3 to 0.4. + +To give you an intuitive +sense, the correlations + +between sex and height, whether +you're a man or a + +woman and height, +is about 0.4. + +So of course lots of women are +taller than lots of men. + +On average, men are +taller than women. + +It's a 0.4 correlation. + +So this is in that range. + +So tests are pretty +good predictors. + +Everybody says that for things +like predicting college + +performance or graduate school +performance, a combination of + +tests and grades are better. + +The difference is grades take +a lot of years to produce. + +Tests are one traumatic +outing. + +So tests are just a +part of our life + +in selection processes. + +So now what is intelligence? + +And it's a loaded word. + +I mean memory is kind +of a neutral word. + +Attention is a neutral word. + +Intelligence is a loaded word. + +I mean nobody wants to be +low on intelligence. + +And so psychologists have +come out of this way. + +But it's kind of funny, because +there's not going to + +be a really deep definition. + +Maybe it's a lot of different +things and how they average up + +or something like that. + +But people have said well, +it's something about the + +ability to solve problems, to +understand and learn complex + +material, to adapt to the +environment, mental quickness. + +Those are all senses you might +have of something that you + +think of as intelligence +in a person. + +But whether they're one thing, +many things, it's very hard to + +pull that out. + +And we don't know too much +about that really. + +And also I want remind you of +something we talked about, but + +it's especially important +in this field. + +We talked about an experiment +versus correlations. + +An experiment, you have to +have a dependent measure, + +something you measure. + +But critically and uniquely, +you have an independent + +variable, something +that you vary. + +That's what makes a study an +experiment, as opposed to a + +correlation. + +So studies of intelligence of +every kind are almost always + +correlational and almost +never experimental. + +That means they're always +subject to lots of + +interpretation and many +factors in the world. + +And that's very important +to keep in mind. + +And again, they tend to focus on +variation in people, rather + +than what is intelligence +itself. + +And again, here's another +correlation + +of height and weight. + +That's a stronger correlation. + +So where did intelligence +start with? + +It's a fascinating story. + +And by the way, let me tell +you the SAT story, on the + +sidebar, for a moment. + +So SATs, nowadays do people, +some people get ready a lot + +for SATs by courses you take +and things like that? + +I read about that. + +When I took it, people weren't +that organized. + +But getting into college wasn't +that competitive. + +And the original goals of SATs +was what, do you know? + +It's really interesting. + +Because it ends up being the +thing, they say well, because + +people who are maybe under more +supported circumstances, + +more financially advantageous +circumstances, get more help + +to get ready for the SAT. + +Those things might amplify SAT +differences in a way that's + +not really about the person +to start with. + +The original goal of the SATs +was to have a national test + +that was fair for everybody, so +that schools like Harvard, + +for example, that tended to +admit the same kind of + +students from the same +small set of + +schools in the Northeast. + +So now, we have a test for +everybody across the country. + +And we can admit people on their +merit, rather than on + +small, social connectivity +networks. + +Does that make sense? + +And yet, SATs are now viewed +as a suspicious + +tool in that regard. + +It was originally meant +to be democratizing. + +It's like everybody in the +country takes the same test. + +It's not whether you have a +connection through a network, + +to our university. + +IQs have the same story. + +For good reasons, and we'll talk +about that, IQ tests and + +interpretations of IQ don't +have a good history. + +But the original goal was +pretty reasonable. + +So in France in 1904, they began +universal elementary + +education, that every +child goes to class. + +And Alfred Binet, a physician, +wanted an objective way to + +identify children who +needed extra help. + +A perfectly good idea. + +A child comes to school. + +Some children are ready to go. + +Some children need a lot of +extra help because they have a + +difficulty. + +So he developed a set of tests +where he probed many different + +abilities, like copying a +drawing, repeating digits, + +recognizing coins, explaining +why a statement + +did not make sense. + +They wanted to probe different +little areas of abilities, so + +if a child is terrible at +something, or two things, the + +teacher knows this child needs +some extra help to get going. + +So that's a good use of +testing, I think by + +everybody's criterion. + +But then testing sort of +took off, IQ testing. + +IQ stands for intelligence +quotient. + +It's a test to give +typical children. + +They give it often for the most +commonly used IQ tests, + +at many different ages. + +They'll test a large number +of individuals. + +And they'll compare what +nowadays what they think of as + +your mental age to your +chronological age. + +So your chronological age is +how long you've lived. + +And your mental age is how +well you score on a test. + +The most famous IQ test, the +most widely used, takes about + +two hours of testing. + +It comes from David Wechsler, +the Wechsler Adult + +Intelligence Scale. + +One for children. + +And within that test, what's +within that test? + +Because when people talk about +tests I think, whatever kind + +of test it is, it can only +about as good as the test + +design itself, to the extent +that it's any good. + +A ridiculous test is a +ridiculous test, even if + +society gives it to you. + +But tests can be better +than that. + +So what is inside the most +widely used IQ tests, + +especially in clinical +environments? + +So let's talk about +one of them. + +It has a bunch of +little tests. + +One is vocabulary. + +They ask you to define +words, similarities. + +They'll ask you a series of +questions, like how are an + +airplane and a car alike? + +Very simple arithmetic +operations. + +Digit spans, how many digits +can you remember. + +Information, they'll give you +a series of questions, like + +who was Martin Luther +King, Jr.? + +Comprehension, they'll ask you +things about the world, like + +why are there taxes and +things like that. + +And you give an answer. + +Somebody scribbles down +when you say. + +And they score you. + +You get two points +or one point. + +We'll talk about that. + +And then they add up these +scores in the subtests. + +So in the nonverbal verbal +tests or the performance + +tests, they'll show you a +picture with a thing missing. + +Have you did that a kid? + +I love those things. + +What's missing in the picture +and stuff like that. + +Blocks, they'll have you +rearrange them into various + +geometric design. + +Picture arrangement, you'll +get cartoon panels and you + +have to put them in the correct +order to tell a story. + +And they measure how accurately +and quickly you do + +these things. + +There's nothing amazing about +any of these things. + +They're probing a variety +of little + +abilities that you have. + +And again, they will take the +mental age and chronological + +age, divide it, multiply +it by 100. + +And they'll standardize it, so +that 100 is the population + +mean in the United States. + +Other countries do these +things, as well. + +Is that OK? + +So I mean a test can only be +as possibly good as the + +content of it. + +And what it measures or doesn't +measure depends on the + +specific conflict of it. + +They'll scale the scores out, +so you get a normal + +distribution, with a +peak in the middle. + +The raw score is the +number you get. + +The standardized one is +adjusted for your age. + +And it's a pretty important +concept, because we'll come + +back to this in a moment. + +The raw score is your +actual score. + +But then they adjust +it for your age. + +Because you don't expect a +five-year-old to do as well as + +a 15-year-old, to do as well +as peak 18 to 23-year-olds. + +And then bad things happen +as you get older. + +I'll tell you a bit of +them about that too. + +2/3 of the people are at plus or +minus 1 standard deviation. + +They set it for that. + +More than two standard +deviations up or down, are + +about 5% on either end of the +distribution of scores. + +And they norm it by age. + +Again, you don't expect a +six-year-old to do something. + +But you get some funny things. + +Not that you have to worry +about this in detail. + +But it gives you a sense. + +So imagine you're a +five-year-old and you take the + +test, on the last day you're +a five-year-old. + +Or imagine you have your +birthday today and + +you're six years old. + +By moving from five to six, from +Wednesday to Thursday, + +you've moved up a year +for the scoring. + +Because they go by +year, not by day. + +So if you would have scored 120 +on the IQ test yesterday, + +when they say what should +you have scored for a + +five-year-old, the very same +test, the next day, + +you would score 100. + +Now, that's the extreme case. + +But you understand what +happens, right? + +Because here's how +well you did. + +That might have been +pretty good. + +120 is above the average +for a five-year-old. + +But the next day, if you're +a six-year-old, now for a + +six-year-old, it's +just average. + +So age has a big effect +on these things. + +Here's something sad for aging, +but good for you. + +Be smart now. + +A 40-year-old who +scores average + +would be a real undergrad. + +If I score like you-- + +no, let me rephrase this. + +If you were compared to a +40-year-old, you would have + +100 IQ, you would +have a 230 IQ. + +Because age knocks down +the score as well. + +So things go up and +then things go + +down, in this problem. + +And usually they think of a +score below 70 as clinically + +concerning. + +And the top 2%, you get to join +Mensa and do whatever + +Mensa people do. + +Which I don't know exactly, +but it sounds interesting. + +An important thing about tests +of any kind, are two huge + +concepts, reliability +and validity. + +So reliability refers to the +idea that if you were tested + +more than once, you would +get the same score. + +The better IQ tests +work a fair bit to + +try to achieve that. + +Validity is the deeper +question. + +Does the test validly measure +what it's supposed to measure? + +So if we had you flip a coin and +said that's your IQ, you'd + +say, that's ridiculous. + +That's not a valid test. + +We could measure your height. + +That would be extremely +reliable measure. + +You'll have the same height +today as tomorrow, if we did a + +decent job. + +That wouldn't be a valid measure +of anything about any + +mental ability, never mind +something like intelligence. + +So those are two important +concepts in + +testing, but very different. + +Now, why do people think IQ +tests are interesting, besides + +just this weird curiosity +about intelligence? + +Because IQ tests correlate with +GPA in high school and + +college, job success, salary, +stable marriages, staying out + +of jail, and how +long you live. + +Again, it's a correlation. + +It could be many different +things. + +The thing I want to talk you out +of is the idea that if you + +have a 200 IQ today, you've got +something stored up that + +will fend off disease. + +It's not that, necessarily. + +It's that there's lots of things +in your life that got + +you to that score. + +And all those things are likely +to persist in your + +life: good health, support of +education, interest maybe in + +taking on challenging tasks. + +You had those before. + +You had them while you +took the test. + +You continue to have +them after. + +Another way to think about it +though, which is both a plus + +and minus, depending on how +you look at it, IQ scores + +account for approximately +25% of the + +variation on these things. + +So that's not huge. + +That means there's many, many, +many other factors, besides + +whatever IQ is capturing. + +But it's about as big a chunk +as you can get for a couple + +hours of testing. + +And we know that other things +like personality, variation, + +education, culture, all those +things blend in on how a + +person will do on all +these outcomes. + +So I'm going to go +back and forth. + +Because on the one hand, we +say there's a lot of stuff + +besides IQ. + +But IQ has some interestingness, +otherwise + +nobody would talk about it. + +And it would just disappear +from the world. + +So on average, on average, what +does 15 IQ points mean? + +So on average, a person with +100 IQ in the US will go to + +high school and a year or two +in a community college. + +On average, these are averages +over huge variety of people. + +You get 15 more IQ points, and +on average, you're likely to + +finish college and have +a white collar job. + +Have 15 fewer points, and you're +not likely to complete + +high school. + +And you'd have to have a job +that doesn't require + +educational background. + +So 15 point on averages +correlate with things. + +Here's another one, because +everybody in the end is a + +little bit curious. + +In your own life, how much of +what you're good at or not + +good at, of any of us, comes +from our genes, from our + +environment? + +Where does that come from? + +What are the things that +support us or limit us? + +So here's one study that took +women from the same family. + +So they're all sisters +from the same family. + +They're trying to control a +little bit of the genetics, + +because they share genes +within the family. + +They're not twins. + +And definitely shared +environment. + +They're in the same household. + +And within those families, they +look at the IQ scores. + +So here's the average group, +above average, well above + +average, a little below average, +a lot below average. + +And they say that in these +women, all coming from the + +same household, here's their +average income and here's the + +average rate of illegitimate +births, which is one measure + +that people think is kind of +a social, on average not a + +desired outcome, to have a +child without a family + +supporting. + +It's not going to help a person +succeed in the world to + +be a single mother. + +And so you can see, the salary +pretty much moves with the IQ + +on average. + +And the rate of illegitimate +births pretty much + +moves with that too. + +So again, it's an average. + +But there's some relationship +between these things. + +Now, if you pick up the +newspaper today and read about + +nuclear disasters in Japan and +problems in the Middle East + +and other things like that, you +would say, it's hard to + +say the world is getting +smarter. + +But you may or may not be +surprised to hear of the + +so-called Flynn effect. + +This was kind of a surprise when +it was discovered, which + +is basically this. + +IQ scores, where they're +measured, go up around the + +world all the time. + +By IQ test scores, it's as if +the world is getting smarter + +all the time, which is kind +of an optimistic thing. + +Whether it's getting wiser +is a good question. + +But by IQ score, smarter +all the time. + +So that's hidden for many years, +because every few years + +these tests get renormed +for the groups. + +Does that makes sense? + +So they're given again and +100 is the average. + +And they're given again and +100 is the average. + +But if they ignore this +averaging and just say, across + +these tests that only change a +little bit, some of them only + +change a little bit, if we just +take the scores, look at + +1930, 1940. + +And it just keeps going up. + +So Flynn is the person who +discovered that the world is + +getting smarter by +raw IQ tests. + +And one of tests they use, I'll +show you an example of + +this, it's another widely +used test called Raven's + +Progressive Matrices, IQs +go up about three + +points every 10 years. + +So that if you were born in +1930, a person would have an + +IQ of 100, their child 108, +and their grandchild, 120, + +with a standard deviation +higher. + +So it's like smarter, +smarter, smarter. + +I don't recommend to go home and +tell your parents that any + +debate you have with them is +pointless, because you're + +smarter than they are. + +But if push comes to shove, +you can look up the Flynn + +effect and have a discussion +about that. + +So somebody who has an IQ today, +just flip it around. + +If you have a 100, your +grandparent would + +have a IQ of 82. + +By this reasoning, people +in 1900 would have + +a mean IQ of 70. + +And nobody knows why it's going +up all over the world. + +There's all kinds of +ideas about maybe + +nutrition is going up. + +Maybe reasoning abilities +are being pushed. + +Maybe educational things. + +I mean it's impossible +scientifically to know why, + +because it's happening in such +a global, giant scale. + +But some people have said, the +tests don't go up uniformly + +across the tests. + +Which gives us a hint about the +way the world is changing + +and how intelligence tests in +some way become a barometer of + +what mental abilities are + +increasingly prized by societies. + +So there's relatively small +gains across years in + +vocabulary or general knowledge +or arithmetic. + +Where there are large gains +are what you might call + +abstract thinking tasks, +like similarities. + +So let's focus on that +for a moment. + +So a similarities question +might be like this. + +In what way are dogs +and rabbits alike? + +If you answer both mammals, +you get two points. + +That's the best you can do. + +And that's what we would call an +abstract or taxonomic one. + +You're abstracting across +the two things. + +Or you could give an answer +like, you use + +dogs to hunt rabbits. + +That's not a wrong answer. + +That's considered a +one-point answer. + +You kind of seem to know what a +dog is, you kind of seem to + +know a rabbit. + +But you didn't give the best +answer by this test criterion. + +Because it's a functional +description of these things, + +not a abstract, conceptual +one. + +So let's think about different +societies, besides the Western + +industrialized one that +we represent mostly. + +In Liberia, they ask people to +sort baskets of food, tools, + +containers, and clothing. + +So most of us, Western educated +in a very broad + +sense, would put the things of +food together, the things of + +tools together. + +Those are the abstract +categories. + +The people from this tribe +put them in terms + +of functional pairings. + +They put the potato next to the +knife they use to peel the + +potato, right? + +And here's the fun thing +in this study. + +They said, what would +a fool do with this? + +And they said oh, well, a fool +would put all the food things + +together and all the +utensils together. + +But that's pointless to do that, +because what are you + +going to do with all the food +things over here, when the + +utensils are over here. + +You understand? + +It's what our society +emphasizes as a + +useful way of thinking. + +So it could be arbitrary. + +But it's not arbitrarily +rewarded and prized in the + +world of education, that +we live in here. + +So intelligence tests attach +value at a specific time and + +specific test. + +Scores are changing over time. + +Different cultures are valuing +different things. + +It's constantly renormed. + +And because of that, here's +another example of how the + +renorming is. + +It used to be for some number of +years, that 70 was used as + +a cut-off for estimates of, +broadly speaking, mental + +retardation. + +And why that matters is that a +person for example would get + +certain kinds of medical +services provided to them. + +When a new version of the WISC, +of the Wechsler test, + +came out in 1991, so a renormed +version, so that + +means the scores are going up, +if every state in the country + +had simultaneously used that +new test when it came out, + +which they didn't quite, but +if they had, the number of + +people rated as retarded, +diagnosed as retarded, would + +have doubled in a single day. + +Because the norms aren't +pushing the numbers up. + +OK? + +So the number of people scoring +very poorly would have + +doubled in a single day because +of the renorming. + +It's very important to realize +that all these things, what's + +really in the test, what's +valued by a sort of society or + +culture, and the norming things +are really influencing + +a lot of how you get +to these numbers. + +So ideas about intelligence, +roughly in this field, have + +come out of what people call + +psychometric analysis of subtests. + +They give you the scatter +of tests. + +And the thing that struck many +people is how for a given + +individual, there's correlations +among the tests. + +A person who does well on one +test, tends to do well on + +another test, and tends to +do well on a third test. + +And a researcher named Spearman +gave this correlation + +among tests, the letter "g," +the name g, to stand for + +general intelligence, and "s" +for specific intelligence. + +And since then, many people have +said well really is there + +one broad sense of intelligence, +are there + +multiple separate kinds +of intelligence? + +And people debate that +in the field. + +And probably somewhat the answer +is it depends what + +you're measuring for and the +purpose of the measurement. + +But a good one to look at, +because it's very clear, is + +the difference between fluid and +crystallized intelligence. + +So fluid intelligence is +what we think of as + +novel problem solving. + +You have a situation +you were never in + +before, what do you do? + +Crystallized intelligence +are facts you know, + +information you know. + +So here's the conceptual +idea that maybe general + +intelligence is a thing. + +And then it shows up on +different tests, with the + +different specific +intelligences. + +That's like maybe verbal +or arithmetic. + +But let me show you the fluid +and crystallized one. + +So the fluid one we said were +first mental processes that + +apply for a novel situation. + +And that declines a lot with +age and adulthood. + +So these lines going down +here, I'm about here and + +you're about here. + +Who should be grading who in +this course, you might ask? + +The only reason that I get to +grade you is because these + +lines keep going up here. + +This is how many +facts you know. + +So the plus of living longer +is that you get + +to know more stuff. + +The risk of living longer is you +don't use it as flexibly + +under novel situations. + +So a pretty strong distinction, +at least with + +aging, between so-called fluid +intelligence and crystallized + +intelligence. + +Here's another study of exactly +the same thing. + +It's a striking ski slope of +decline in fluid intelligence. + +Look at this, ernt, from 20 +to 80, it just goes down + +relentlessly. + +But when it comes to +crystallized intelligence, + +things like vocabulary, that +kind of hangs in there, until + +you have some big +health problem. + +So at least those two +kinds seem to + +have a different basis. + +And people have thought about +different ways to think about + +intelligence. + +And I'll just tell you that in +general you get positive + +correlations among the tests. + +And so often people think +about this general + +intelligence. + +The correlation among +the tests is + +the best single predictor. + +Now, there's lots of responses +to ideas about intelligence. + +One of them is the study of +emotional intelligence. + +Peter Salovey is the researcher + +most involved in that. + +And we know this in +everyday life. + +We know smart people, what we +might call book smart people, + +who seem unwise in how they +relate to people, how they + +perceive emotions, how they +facilitate thought with + +emotion, how they understand or +manage their emotions, how + +they relate to other people. + +And so it's common sense to +think of that as something + +that varies across people. + +It's very hard to +measure that. + +I mean, part of the tyranny of +tests is what can be measured, + +gets measured. + +What's hard to measure, +is hard to measure. + +It's very hard to measure, in +a laboratory, in an hour, a + +person's emotional +intelligence. + +People have tried. + +It's just hard to do. + +Here's another area that's +gotten a lot of attention, + +from Howard Gardner +at Harvard. + +Kind of fighting back against +this idea of a single form of + +intelligence as captured by +g, the idea of multiple + +intelligences. + +And looking at things, the +associations in patients and + +development. + +That we can talk about +linguistic intelligence, + +spatial intelligence, music +intelligence, bodily + +intelligence. + +Great athletes have great +bodily intelligence. + +Intrapersonal or interpersonal, +it's kind of + +like emotional. + +Existential. + +So he said, there's all these +different kinds of + +intelligence. + +And each person is a +profile of these. + +You can be really strong in one, +and medium in another, + +and not so strong in another. + +The problem with this whole +approach is, yes, it's true + +that people have a +huge variety of + +facets of their humanity. + +This whole course, I feel like +every lecture we do, we just + +turn a person a little +bit to study another + +facet of their humanity. + +But it's hard as heck to +measure interpersonal + +intelligence or naturalistic +intelligence. + +Now, maybe somebody will figure +out how to do that. + +It's just hard to measure those +things, even if it feels + +like something conceptually +that's there. + +So this idea, which has had a +lot of resonance to people not + +liking very simple-minded ideas +of intelligence, very + +unitary ones, it's still not +gained much traction in + +practical use. + +So let me talk a bit about some +of the things that people + +have said, well, if we talk +about this intelligence, what + +might be some mental mechanisms +or neural + +mechanisms that support +or underlie it. + +So some things that go with +it are mental speed. + +And you know this, kind of +quickness of thought. + +OK, not even big thoughts, just +quickness feels like it + +helps a person solve problems. + +So for example there's a +moderately high correlation + +between IQ, complicated tests, +of all those tests, and how + +quickly you push a button +when the light comes on. + +Now, we never say, wow, Sally +or Fred is really smart. + +They can push a button +when the light + +comes on really fast. + +Let's go to them and get the +answers for the problem set. + +But that would go with the idea +that simply being fast is + +kind of a useful thing for +acting on the world. + +Or how quickly people decide +whether two lengths, two + +lines, are the same length +or a different length. + +Very simple thing, just speed. + +And another idea is working +memory capacity. + +How much information you can +hold in your head at any one + +time that's relevant +to the problem or + +task in front of you. + +So people have tried to explore +these in certain ways. + +And I'm going to talk to you +about a couple of brain + +studies that have tried +to look at this. + +So again, we talked last time +about frontal cortex and + +different parts of it. + +And especially the +dorsal-lateral prefrontal + +cortex is involved +in thinking. + +And so people have taken tasks +and said, what happens when + +you think about them? + +So here's one, an easy item +on the so-called Cattell + +Culture-Fair Test. + +So which of these things +goes into here. + +There's harder ones. + +Or here's a slightly adapted +version of the Raven's + +Progressive Matrices. + +I'll let you think about +that for a moment. + +I don't remember which it is. + +So you're told here's some +rows and columns. + +One of these eight answers +logically fits in here. + +And it's your job to figure +out which one. + +Let's see. + +How do we like-- + +three. + +I like three too. + +Does that three seem OK? + +This is a medium-hard item +on this kind of a test. + +And then they do these kind +of map of results. + +This is what's fun about +the Raven's test, the + +item you just saw. + +Which is they sort of looked +at lots of other tests, so + +specifically spatial tests, +specifically verbal tests, + +specifically math tests. + +And they said if we have to give +you one test only, one + +test only, what test would best +predict your performance + +on all the other tests? + +And the answer is Raven's +or IQ tests like that. + +So of course if I give you +a math test, that better + +predicts your math +performance. + +If I give you a verbal test, +that better predicts your + +verbal performance. + +If I gave you a spatial test, +that better predicts your + +special performance. + +But if I want to give you one +test that gives me the best + +prediction of your performance +on other tests, it's things + +like these IQ tests +that do that. + +And that's just empirical. + +That's not arguing about +values or what + +intelligence is. + +A lot of people who work in this +field, they don't even + +care about these arguments. + +They just say, I just want +a test that predicts. + +It's your job, if you wanted +to figure out why it is. + +It's the genes, environment, +education, whatever. + +I just want a test +that predicts. + +So from that perspective, +these tests + +have a strong history. + +And what turns on in the +brain when you solve + +this kind of a task. + +Well, the frontal +cortex a lot. + +The parietal cortex. + +But especially, frontal +cortex. + +So it goes with our idea that +thinking is very much tied to + +prefrontal cortical function. + +Here's another example of a +study that said, let's compare + +what happens in the brain when +you have test items that are + +hard, which is the outlier one +here, that require a lot of g, + +or items that are easy, that +require very little g. + +Will up here in the brain, what +happens when you turn on + +your g, so to speak? + +And again, the prominent areas +tend to be, for both spatial + +and verbal, prefrontal cortex. + +One more. + +the n-back task, we +use that a lot. + +Where your job is, +letters come on. + +And in this one, one-back, you +say, what do I see a letter + +that's the same letter +as the one before? + +So, for example-- + +two-back, sorry. + +So you see, R, R, M, X, this +is two-back, because an M + +occurred two items ago. + +Three-backs are really hard. + +Because the letters are going, +boom, boom, boom, boom. + +And what's hard about it is, +the letter in front of you, + +you have to say does it match +the one I saw three letters + +previously, plus remember that, +because it's going to be + +the target for the one that +comes three after. + +It's hard. + +I can tell you it's hard. + +You can be smart. + +It's pretty hard. + +And for this task in general, +the harder it gets, the more + +you turn on the dorsal-lateral +prefrontal cortex. + +And so they did this test with +students in Washington St. + +Louis, Louis, related it to +performance on the Raven's. + +And sure enough in the brain, +it's again prefrontal cortex. + +So a bunch of studies have found +all these tests involve + +a fair bit of the brain. + +But they seem to really draw +upon the capacities that you + +and I have in prefrontal +cortex. + +And one more note, in brain +imaging when we talk about + +things, sometimes it's better +to have more activation and + +sometimes less activation. + +And you have to know the +behavior to know that. + +So whenever you see somebody +saying oh, this person, this + +group, or whatever, had more +brain activity or less brain + +activity, you don't know until +you know the rest of the + +behavior, whether more +is good or bad. + +Sometimes when people get really +good at something, they + +use less of their brain, because +they can do it so + +efficiently. + +So here's an example of people +with lower and higher IQ doing + +an n-back task. + +And you can see that the people +with lower IQ have much + +more activation than the +people with higher IQ. + +It's as if these people have +to use all their brain + +resources to accomplish this. + +And these people only +have to use some. + +It's as if it were that. + +So here comes one of the +classic topics of + +the fate of a human. + +How much is your genes at birth +and how much is the + +environment that you're in. + +And if we were really to +understand that in a deep, + +deep scientific way, we would +know the genes are related to + +intelligence; the experiential +factors in the world, family, + +education, emotional support, +and so on; how they interact. + +All those things, we know +practically nothing about. + +I'll show you one +tiny example. + +We know practically nothing +about them in + +any depth at all. + +So we mostly end up using twin +studies to make the best + +estimates we can. + +Which doesn't tell you +what the factors are. + +It just tells you how much is +a twin who is identical more + +or less like a twin +who is fraternal. + +OK, we'll come back to that. + +But I do want to tell you sort +of an exciting direction + +that's slightly getting at the +genetic story of this. + +So you may know, many +of you more + +than I do, about genetics. + +But single nucleotide +polymorphisms are DNA + +variations. + +These occur relatively +commonly. + +They're estimated to make +up about 90% of + +human genetic variation. + +And they're constant from +generation to generation. + +So people have studied a few +of these variations among + +people and related them +to performance. + +So let me remind you of +something from last lecture, + +the Wisconsin Card +Sorting Task. + +Where you sorted these cards +mysteriously and we said that + +if you have a frontal lesion, +you do poorly on this task. + +You get stuck with one kind of +problem solving or habit, + +answer even when it's wrong, +in a new circumstance. + +So what people have done is look +at one particular gene + +that's related to this enzyme +that modulates dopamine + +function in the prefrontal +cortex. + +So it's a risk factor +for schizophrenia. + +It metabolizes dopamine +in prefrontal cortex. + +We vary with which version +of this gene we have. + +And here's the performance +on the card sorting task. + +And let me pick these. + +These are healthy people. + +If you have this version of the +gene or this pairing or + +this pairing, your card sorting +task is going up. + +So this is kind of amazing +that we're close to that, + +where a single gene +is varying. + +Now, the score doesn't +go up a lot. + +It accounts a small percent +of the variance. + +But it's one gene having an +identifiable correlation with + +performance on a +demanding task. + +And you can do this n-back +kind of task + +we just talked about. + +And then you can look in the +brain as people are performing + +this, divided by which version +of this gene they have. + +And what you get is more +activation in the people with + +this complement, than +this complement. + +Sort of consistent with the idea +they're working harder. + +There's the same group of people +who are performing less + +well in the card sorting task. + +So there are some genes that +have been identified that are + +associated with what we may call +broadly, intelligence. + +But that one gene only accounts +for a tiny bit of the + +overall score on these +kinds of things. + +And we don't know much more +about it than that. + +So how do people even +begin to think + +about nature and nurture? + +And I like to think about +this in two ways. + +One way is narrowly IQ tests, +because there's been so much + +work in that area. + +But it's the deep question +of how do we get + +to be who we are? + +So again, they mostly look at +twin studies, so-called + +behavioral genetics, and +estimated heritability, how + +much of variation is +due to genetics. + +And I'll come back to +this height thing. + +But to give you a sense, height +is thought to be 90% + +inheritable in the US. + +Tall parents on average will +average will have taller kids. + +Less tall parents, +less tall kids. + +And in twin studies, they +contrast monozygotic twins, + +twins that are identical or +have the same genes, with + +dizygotic ones, who share some +genes, but not nearly as many. + +Of course, they share the +same environment a lot. + +Have you guys seen the two twins +talking to each other + +video on YouTube? + +If you haven't seen it, +it's kind of fun. + +The two twins are babbling. + +But they're so demonstrative, +it's as if they were talking + +to each other in babble. + +It's kind of fun, if +you haven't see it. + +It's very cute. + +Here is it again. + +The fraternal twins and here's +the identical twins, before + +they're born. + +This has been studied +a fair bit. + +Here's the correlations between +IQ scores and people + +of varying relations. + +So let's work down that list. + +Unrelated persons, +reared together. + +So perhaps an adopted +person and his or + +her sibling or something. + +They're correlated at +about what, 0.2. + +Foster parent and child, it +goes up a little bit. + +Parent and child living +together, so that's a + +biological parent and child +living together, that goes up + +a fair bit. + +Brother and sister reared +apart, back down. + +Brother and sister +reared together. + +So you could look at this +as kind of shared genes. + +And this might be something +like environment. + +Does make sense? + +Intuitively. + +That's assuming there's no +interaction between genes and + +the environment, which +we know must happen. + +So when I do this I'm treating +them as if they were additive + +and independent. + +Everything we know about genes +and the environment are + +tremendously interactive. + +We just don't have insight +into that in any + +deep way, in humans. + +Here's the really +stunning one. + +Identical twins reared apart, +70.7 correlation. + +Identical twins reared apart. + +That suggests a huge +influence of genes. + +Identical twins reared +together, 90.9. + +So this is the finding +that stunned people. + +So look at identical +twins reared apart. + +They're much more like each +other than a brother and + +sister reared together, who +share all the same environment + +of education, parental support, +and other things. + +So I'm going to come +back to this. + +But as best people can estimate, +and these might be + +radically replaced as we deepen +our understanding of + +the actual genes and the actual +environmental factors, + +but people are estimating +it's about half + +and half for IQ tests. + +And we discussed the bit of +arbitrariness in that. + +So about half and half. + +Let me show you a couple of +environmental influences that + +have been identified. + +And the first two, one suspects +has to do on average + +with something about the +healthiness of the environment + +the child was born into. + +The third one is kind of fun +just to talk about because you + +may wonder if you have a sibling +or no sibling, what + +does it mean that you were first +born, or second born, or + +third born, at least +statistically. + +So let's do the first two. + +Here's breast feeding, 3,000 +people were followed from + +birth to young adulthood, who +had breast feeding, for at + +least six months, correlated +with a five to + +seven point IQ gain. + +So we said, 15 points really +seems to mean something in + +educational outcome. + +So 5 to 7 is half of that. + +So that's something. + +So let's talk about +this for a minute. + +You could say, and I can tell +you as a parent who fairly + +recently had children, all the +mothers in the US that I know + +were going like, I've got +to breast feed and + +get my kid to MIT. + +Two more months of breast +feeding and this kid could go + +all the way to tenured +faculty. + +I can tell you there's a lot of +pressure on mothers, if you + +don't know this. + +Not my mother. + +But now mothers hear, do this +for your kid, do this for your + +kid, do this for your kid, +because of results like these. + +So one possibility is there's +something in breast milk. + +That would be the +direct mechanism + +that's making kids smarter. + +Give me another possibility that +has nothing to do with + +the breast milk? + +Yeah? + +AUDIENCE: Maybe mothers who +breast feed, also tend to be + +mothers who are more nurturing +to their children. + +PROFESSOR: It could be +more nurturing to + +children in many ways. + +They could be mothers who can +stay home and spend some time + +with the children versus being +under very pressured economic + +circumstances that +prohibit that. + +It could be a lot of things. + +Does that make sense? + +We don't know. + +Nobody has shown yet that it is +the breast milk that goes + +into your brain and pushes up +your brain, in any sense. + +It's just a correlation. + +And of course, if you're a +parent, I'll do the breast + +feeding and let the scientists +figure it out in the future. + +Here's another one. + +There's the birth weight. + +So again, you could say +the same thing. + +I mean certainly having very low +birth weight is a big risk + +factor for lots of things. + +But birth weight again goes +with many factors in the + +environment that are supportive +for a healthy + +pregnancy versus not. + +So it doesn't mean that +it's the birth weight. + +It could be all the other +things that were in the + +environment during the +pregnancy, at birth, and + +continue, on average, in the +environment of that child, + +throughout their childhood +and young education. + +Does that make sense? + +If they're born in a very +unsupportive medical + +environment, they might have +a low birth weight. + +And unless their parents win +the lottery or something, + +they're likely to be in a +difficult environment for all + +their educational +years to come. + +So people have tried to make +clear, because it's so easy to + +get into sort of little mental +traps on genes versus + +environment, how genetic +diversity affects + +heritability. + +So there's a couple different +ways to do it. + +Let's do this one. + +So imagine you had cloned +tomato plants. + +That means they all have the +exact same genes in this + +hypothetical example. + +But somebody has poor soil, +somebody has good soil. + +Well, you'll get big +differences. + +And the heritability +will be zero. + +Environment can have +huge influences. + +But if you have genetically +diverse plants, then you're + +going to have an interaction. + +So some plants will do OK, +even in poor soil. + +Some plants will do most +spectacularly in good soil and + +less spectacularly alike. + +Environment by genes' +interactions. + +And you can see this in so +many different ways. + +So here's one example. + +So we said height is 90% +heritable within a society. + +But Japanese men in the US, or +people with Japanese extract, + +are three inches taller +than people in Japan. + +So they still have whatever +Japanese genes are. + +They have Japanese genes. + +But they're in the US getting +the US diet of McDonald's. + +And it's pushing them +up three inches. + +Height is heritable. + +But environment is a big +part of the story. + +So it's just both. + +Now, here's a fun study. + +And a reason that if you're +a younger sibling and you + +desperately want two IQ points, +you might knock off + +your older sibling. + +I don't recommend this. + +This is tongue-in-cheek. + +But it's kind of fun study, +just thinking about birth + +order more in a fun way. + +Well, look at the whole +thing, we're talking + +about from 99 to 104. + +So it's five points we're +talking there. + +But in some countries, they sort +of test everybody going + +into the military. + +And I think this was +done in Denmark. + +And what they said is. + +These are all children. + +These are the IQ scores. + +And these are the IQ scores +that you would have. + +But what happens if your +older sibling has + +passed away, sadly. + +You get those points. + +And here's a person who +has an older sibling. + +And the older sibling +passed away. + +And they moved up +those points. + +That is, if you're a younger +sibling, you have a few lower + +IQ points, on average. + +But kind of strikingly, if +your older sibling passes + +away, sadly; you seem to get +those IQ points as you move up + +the birth order. + +Yeah? + +AUDIENCE: Is this if they pass +away before birth, or --? + +PROFESSOR: Yes. + +Yeah, when they're young. + +It's too late. + +Sorry. + +For all you in here, too late. + +It's only a couple +points also. + +But this got into Science, +because people are always + +wondering about-- + +there's been a huge curiosity +about birth order + +consequences. + +But let's talk a little bit +about birth order again. + +Because there's a second really +interesting point. + +So here's Raven's score. + +And here is if you're a lone +child, the second of two + +children, the third of three, +the fourth of four, the eighth + +of eight, to ninth of nine. + +You can see the scores +keep going down. + +It's not dramatic, but +larger families. + +And you can have a million ideas +about why that would be. + +About why it is the larger your +family and the further + +you're down on the list, you +lose a few IQ points for every + +sibling who's older. + +So here's one idea from Robert +Zajonc, who's a very creative + +psychologist. + +We're not sure that +it's right. + +But I think it's really +fun to think about. + +So here is this idea. + +He said, I'm going to make up +an idea, which is this. + +The first born, maybe he is +exposed only to adults. + +The adults are talking to them +about the views of the day and + +all kinds of things. + +The second born has two +adults, let's say + +in a typical family. + +But also has an older sibling. + +So the intellectual environment +will be the + +average of two adults +and a little child. + +The next one, and so on. + +So he said, you can do +a kind of a formula, + +which is like this. + +Pretend the two parents are +each 30 and you're born. + +We'll call your family +intellectual stimulating + +environment, 30. + +Because we'll add up the ages +and divide by the number of + +people in the family. + +Does that make sense? + +This is not meant to be +a real formula, just + +a conceptual plan. + +And then he said, now you have +the two parents and you have a + +four-year-old sibling, because +you're the second born. + +So now there's four of you. + +We divide by 4. + +And we'll say the average +intellectual thing in the + +family is 16. + +By the time the next child comes +along, a seven-year-old + +sibling, three-year-old, +divide by five, and the + +average intellectual +environment is 14. + +Here's the idea. + +On average, it's better for +a child to have lots of + +interaction with a parent, +that with a little kid. + +Because a parent will stimulate +you more than a + +little kid, although a little +sibling might be a lot of fun. + +But purely IQ land, two parents +talking to you about + +stuff, is a more educational +environment than two parents + +plus a sibling who is two +years older than you. + +Because the two-year-old +can't help. + +No matter how smart he or she +is, they can't talk with you + +like an adult. + +This is the thought. + +And now, here's the really +fun observation. + +And again, we don't really know +if this is exactly right. + +But every year, if you're around +issues of education, + +there's test scores that +different states have. + +And the test scores go up. + +And you have taken high-tests +tests right, in high schools + +and grade schools and stuff. + +If the test scores goes up, +everybody goes, oh, reelect us + +because we're awesome +administration and our test + +scores are going up. + +We're doing everything right. + +If the test scores go down, they +go oh, throw the bums out + +of the administration. + +Their kids are watching too +much MTV, turn off that + +computer, and so on. + +Everybody gets the +test scores. + +And they figure out who's good +and who's bad, parents, + +teachers, school systems, +politicians, whatever. + +Zajonc says, and this is kind +of an interesting thought. + +He says no, he can predict +whether scores will go up or + +down simply by on average in a +given year, whether there are + +more first borns, or second +borns, or third borns. + +That if he just takes that +population average of every + +kid, the moment they're born, +he can predict years later + +where the scores go. + +And so here's the +scores in Iowa. + +Of the actual scores, they're +going up and down. + +So you can imagine, scores +are going down. + +Everybody's really upset about +kids who don't study, and + +teachers who don't teach, and +parents who don't parent. + +Scores are going up. + +And the kids are awesome, the +teachers are awesome, the + +parents are awesome. + +Because that's who +gets the credit. + +And he's saying, uh-uh. + +This is my prediction here, +based simply on for a given + +birth year, the average +number of older + +children in your family. + +That's it. + +And look how well that tracks. + +It's unbelievable. + +So it just makes you rethink +that so often when we get + +information about society of +what's going on, this may be + +right or wrong. + +But we don't really know +what's going on. + +There's all kinds of huge things +out there in the world + +that aren't the easiest things +to blame or give credit to. + +So they're relatively small +differences, but they seem to + +track interestingly in the +number of siblings you have + +who are older than you. + +And at the same time, +this idea of + +parental exposure to language. + +There's this widely cited study +from Hart and Risley. + +So they recorded for each month, +for 2 and 1/2 years, a + +heroic recording, one full hour +of every word spoken at + +home between parents and +children in just 42 families. + +But they categorized them +as high, medium, or low + +socioeconomically. + +So in terms of income +and education. + +OK. + +And they're recording +lots and lots of + +conversations verbatim. + +And they code and analyzed +every utterance in 1,300 + +transcripts of 30,000 pages. + +The reason why this is not +done a lot, it's not very + +glamorous work to do. + +You can imagine sitting +down there. + +But they're recording lots of +conversations at home in + +families who are better off, +medium off, or poor. + +And they're looking at what is +the conversation like, for an + +hour a day. + +And here's what they find. + +That variation in children's +IQ and language abilities + +related to the amount +that the parents + +speak to their children. + +And that the academic success by +age 8 or 9 or 10 is related + +a lot to speech at 0 to 3. + +Now again, you think causally. + +Because you think, parents are +talking to you at 0 and 3. + +And 9 and 10, you're doing + +differential equations, causally. + +No. + +The parents that are talking +to you a lot, 0 to 3, are + +talking to you at 4, 5, and +6 a lot, most of the time. + +So if these things are not like, +you get an injection, + +you're done. + +Many of the factors that we +can measure, continue on + +average, for most people +in their environment. + +But it's very impressive how +the environment altogether + +influences things. + +By age 3, the cumulative +vocabulary is 1,100 words in a + +professional family as a child, +750 in a working class, + +and 500 in a welfare family. + +And welfare families, 600 words +per hour, working class + +750, professionals 2,153. + +By age 3, the vocabulary used +by children in the high SES + +homes, is larger than the +vocabulary used by parents in + +the low SES. + +By age 3, larger vocabulary. + +This is just telling you the +incredible cumulative power of + +strong environmental +influences. + +Because it's unbelievably +multiplicative. + +It's every day, all day long. + +And if you're in an environment +that's supportive + +or an environment that's not. + +It's not one shot. + +It's every day, multiply, +multiply, multiply. + +300 words more per hour +for professional, + +than the welfare family. + +Extrapolate to a year. + +A child in a professional family +hears 11 million words, + +versus 3 million in +a welfare family. + +And strong correlation with +IQ scores by age 9. + +So very huge differences +in what children are + +exposed to at home. + +And they correlate highly +with these IQ things. + +So the literature is that on +average, on average, the IQ + +scores that children have around +9 or 10, correlate + +pretty well with ones +they'll have for the + +rest of their lives. + +Before that, it extremely +jumps around. + +We don't know why. + +But that's they're finding. + +By the time in 9 or 10, whatever +you have, on average + +tends to hang in there. + +If you're 100 at 10, you'll +tend to be 100 at 20. + +If you're 120 at 10, you'll +tend to be 120 at 20. + +Does that make sense? + +So there's been a lot of +interest in evidence about + +whether you can change +your IQ as an adult. + +So here's one study that got a +lot of attention, because it + +was kind of interesting +in that way. + +So they did a complicated +task like this. + +This was an n-back task. + +Simultaneously you hear letters +and you see little + +spatial locations like this. + +And every time something matched +two items ago, you + +would push a button. + +So you're hearing them +at the same time. + +And if you hear a letter +that was two letters + +ago, you push a button. + +Or same spatial location, +you push one. + +It's pretty hard. + +They took 34 adults. + +They trained them from +eight to 19 days, + +so less than a month. + +Skipped weekends. + +25 minutes a day. + +It's only half an hour a day. + +They train on this. + +And then they tested them on +some of these widely used IQ + +types of measures. + +Here's their performance on +the task itself, getting + +better and better. + +OK, that's not surprising. + +And the more they practiced, +the higher they got. + +So if you practice really hard +at something, you get better + +at doing it. + +That's not the thing they +were interested in. + +They were interested in this. + +Here's the IQ scores before +they were trained. + +The IQ scores. + +They didn't practice +the IQ tests. + +And here's the IQ +ones afterwards. + +This is the control group, +who did nothing. + +This is the group that did +the mental practice. + +And you can see, they pushed +up their IQ scores. + +Not a lot. + +But it was only 20 minutes a +day for less than a month. + +So these kinds of studies +really intrigued + +people in two ways. + +And the more training you +got, the more your + +IQ score went up. + +The more weeks you did this. + +Because a), maybe we could push +up IQ scores, if that's + +important to push up. + +This is a big decision. + +Even when you're an adult. + +What if you did more than 20 +minutes a day for three weeks. + +And b), maybe we could push up +everybody's IQ score, who + +needed help in that, with +the right kind of + +training, at any age. + +So a lot of interest in that. + +So let me take a step now to +sort of harder topics. + +Now, one of the reasons that +intelligence and IQ topics + +have gotten appropriately lots +of concern is a terrible + +history of racism and sexism +associated with IQ tests and + +the way people use that to argue +basically inferiority of + +groups, other than themselves. + +So the US Immigration Act of +1924, the official government + +talked about biologically +weak stocks. + +At that time, they were focused +or prejudiced against + +Italians and Jews from Europe. + +Different societies, different +times, as you know, + +tragically, had biases against +different groups in the world. + +Unfortunately, it's part of +the world we live in. + +And even though we know now with +certainty that we're all + +almost identical genetically in +any practical sense across + +racial groups, race remains a +powerful social category. + +It's a very complicated topic. + +The experience you've had, is +the experience you've had. + +But we know it's a +social category. + +People identify to a certain +extent with that. + +They recognize other people +in that context. + +We'll come back to that +later in the course. + +But it's a sort of fact of life +that we often think of + +ourselves as belonging to one +racial group or another and + +somebody else as belonging to +one racial group or another. + +So I'm going to focus on one +thing that's both troubled + +people and led to bad things, +but has some interesting, + +important aspects +to think about. + +So in the US, when people +compare African American and + +European American scores, +there's a gap of scores that + +grows over time. + +So in infancy, to the extent +you can test these kinds of + +things, there's no difference. + +By age 4, on average, people who +are European American will + +tend to score about four +or five points + +higher on IQ tests. + +And as the goes up, it +continues to go up. + +There's a gap on average. + +This is a huge average. + +It's across many people across +time, as people get + +older in the US. + +Now, we've strongly believed +for many, many reasons + +empirically that this is an +environmental influence. + +And here's one example of +many pieces of evidence. + +So that children fathered, for +example, by Black America GIs + +in Germany, brought up by German +mothers, have exactly + +the same IQs as white +American GI + +children and German mothers. + +That is, in countries where +stereotypes were applied in + +general, partly because there +wasn't a history of African + +Americans in Germany at +that time, the IQ + +scores are the same. + +So we think it's overwhelmingly +evident that + +it's an environmental effect. + +But in the US, there's a lot +of relationship between, on + +average, across the entire +country, on average, between + +what group you're in +and average income. + +So here's the average income a +few years ago, depending on + +which group you identified +yourself as belonging to. + +So we talked earlier about the +relationship between economic + +comfort or stability or support +and things like the + +number of words a parent can +speak to or it's time to speak + +to their child. + +And the habit seems to correlate +with all kinds of + +advantages. + +So here's an incredibly powerful +and important idea. + +Claude Steele is a researcher +at Stanford, who I knew, who + +has played a big part in this. + +And here's the idea. + +So it's called stereotype +threat. + +It applies to all of us. + +But in some ways depending on +the world we live in, some of + +us can be more vulnerable than +others in certain situations. + +Here's the idea. + +So let me tell you the +experiment and then the + +interpretation. + +The experiment is that he'll +bring people in and give, + +Claude or his students, black +and white participants, + +college students. + +And they say, it's a laboratory +experiment. + +And they give them something +like an SAT test. + +And the groups perform +just the same. + +Stanford students, black and +white, perform just the same. + +That's the one group. + +Here comes the next group of +black and white students, who + +are told we're going to give +you a test of intelligence. + +Now, look what happens. + +The scores of African +Americans go down. + +And it doesn't even have to +be the phrase "test of + +intelligence," you can have +people just tick off, on a + +front page, what racial group +they belong to and you get + +almost the same effect. + +So what is this? + +This is understood as stereotype +vulnerability. + +That is, tragically in the US +there's a stereotype that + +African Americans +are not as good + +academically as white Americans. + +It's a pernicious stereotype. + +It's one we can decry morally +and say it's a bad thing. + +But it's out there. + +There's another area where +African Americans are thought + +of as phenomenal by stereotype, +which is sports, + +in this country. + +It's a weird thing. + +The idea is that knowledge of +these things, even if this is + +your real performance, once that +thought enters your mind + +that I'm doing something that +some people say I'm not going + +to do such a good job at, +is enough to make you + +underperform compared to +your true potential. + +So the other area where this +has been studied a lot is + +women and mathematics. + +I think that's disappearing. + +When I grew up, everybody was +worried that women weren't + +given as good an academic +support as men + +or girls and boys. + +OK, it's reversed. + +In my lifetime, it's reversed. + +Because now, by every +criteria, women are + +outperforming men in the US by +every criteria, at least + +societally, the number who +finish school, your beginning + +salaries, everything. + +So now they're worried +that us boys are + +really being left behind. + +So these things change because +they're cultural inventions. + +They're cultural inventions. + +And cultural morays change. + +And sometimes in good +ways, hopefully. + +So stereotype threat is that +other's judgments or one's own + +actions will confirm negative +stereotypes about one's group. + +Oh, you should do badly on +something or you should do + +well on something. + +So they studied on women +on that, old people. + +Athletic ability of course +runs the opposite. + +The experiment was +kind of fun. + +They had a very athletic African +American instructor + +come up and start +doing push-ups. + +And all the white guys started +to lapse in their push-ups. + +They got tired really fast, +compared to an equally + +athletic white trainer who +came up to the front. + +Does that make sense? + +Does that make sense? + +It's whatever is the stereotype +you have in your + +head, if you say OK, oh, oh, I'm +not supposed to do so good + +in this, you underperform. + +Not everybody, all the +time of course. + +But enough that we have to +be concerned about that. + +More for academic performance +probably than push-ups. + +But who knows. + +So here's this achievement +gap. + +And different scores between +again, at age 13, between + +whites and blacks in the United +States, which we know + +shouldn't be there. + +Many factors are in it. + +A huge variation among +people, of course. + +These are huge averages. + +But one that everybody wants +to get rid of, in a just + +society where everybody has +an equal opportunity. + +So here's a result that's so +unbelievable, that if it + +weren't for some subsequent +results, I wouldn't even show + +it to you, even though it's +a well-done experiment. + +But the message of it +seems so incredible. + +So here's what they did. + +In this well-controlled study +in Science, and there's been + +some follow-ups that have +exactly done this. + +So they took African American +students and white students. + +And they had them take +these various tests. + +But some of them, at the +beginning of the year, wrote + +an affirmation. + +They had to choose a value +from a list and write an + +in-class essay about why +the chosen value is + +important to you. + +The controls chose a value +from those same lists and + +wrote an in-class essay about +why the value might be + +important for somebody else. + +You're writing a one-time essay +about why something + +matters to you or matters +to somebody else. + +So obviously what matters to you +is more powerful for you. + +And by just doing that, there's +a 40% reduction in the + +African American students +in the study in + +their achievement gap. + +Their scores went up 40% because +they wrote one essay + +at the beginning of the year +about why values are important + +to them and related +to education. + +One essay did that. + +Unbelievable. + +And just a reminder about how +much one's attitude incredibly + +influences your performance. + +You have a range of things +you can do it. + +And what gets you to the top of +your range that's in you, + +or the bottom of your range, +has a lot to do with + +attitudes, that can be moved +around by a lot of things. + +One essay overcame a tremendous +amount of the + +concerns that on average, +African American students have + +about academic achievement. + +And it's not just that. + +So in this course, you only get +a couple of tips of things + +that are useful to +you for courses. + +Here's one. + +It's the same principle, +but it seems + +to apply for everybody. + +So here's the experiment, also +published in Science. + +It's really cool. + +So they brought in students. + +And they said, look students +often are worried about how + +they're going to do in a test, +especially if it's an area you + +think you're not so good in. + +So they had them take a test on +Gauss's modular arithmetic. + +Here's the pre-test. + +Everybody did about the same. + +Then they said, OK now, they +have to create pressure. + +Because of course if you take +a test in an experiment, + +that's not pressured, right? + +Pressure is the grade you're +going to get, whether it lets + +you into medical school, whether +you get to become the + +head of the American Medical +Association. + +That's pressure, right? + +So they say oh, here's what +we're going to do now. + +We're going to give you another +test, everybody + +scoring about the same. + +But you can make a fair bit of +money with a partner who's + +down the hall. + +We should tell you that partner +has already done a + +really good job on the second +version of the test. + +So if you don't do well, you +don't get money and the + +partner down the hall doesn't +get your money. + +If you do well in the second +test you're about to take now, + +then everybody wins. + +So they're trying to make +you feel pressured. + +On man, I want to +win the money. + +Plus there's a guy down the hall +who already did well and + +I'm going to let us down. + +They're trying to +make you feel as + +pressured as you might. + +As much as they can in an +experiment, like you do in a + +regular test, in a +regular course. + +So trying to create pressure +and anxiety. + +And then for 10 minutes, the +controls just sit there and + +think about it. + +Oh, I hope I don't +mess up now. + +The pressure is on. + +I hope I don't meet the person, +if I don't do a good + +job, down the hall. + +An expressive group wrote an +essay for 10 minutes about + +their thoughts and feelings. + +Oh, I wrote this. + +This is a huge mistake. + +This should be "better." +I'll fix it up. + +Better, better, better. + +I did it unrelated, +in writing. + +So here's what happens. + +The group that just sat +there did nothing. + +Their performance doesn't-- +let me get this right. + +The performers that wrote the +expressive writing, their + +score goes up. + +Everybody else's +scores go down. + +Because here, here's where +they're beginning. + +Now, they get pressured. + +And they perform less well. + +They're choking. + +The group that wrote +the essay, their + +performance stays up. + +And it's kind of ironic, because +a theme of comedy is + +frequently when they tell you, +whatever you do, don't tell + +somebody x. + +And then my mistake, +you tell x. + +Have you seen that +a comedy show? + +So you could have thought, well +writing an essay about my + +thoughts and feelings about how +much anxiety and pressure + +I feel, is like the worst +thing you can do. + +It's like, I don't +want face it. + +I'd rather clear my mind. + +But it turns out that when +people write this little essay + +about the thoughts and feelings +about their anxiety, + +their scores rise. + +And if they don't write that +kind of an essay, the scores + +fall, because you've introduced +here the stress and + +anxiety that we think is a +part of regular testing. + +Does that makes sense? + +I'll fix the slide. + +I'm sorry about the typo. + +Is that OK? + +I'm almost a little afraid to +give you advice, because + +somebody will write an essay, +do bad on the physics test, + +and say oh, this is terrible. + +I would have gotten a A. + +But it seems like writing a +little essay about your + +thoughts and feelings actually +pushes scores up. + +I mean that's the scientific +evidence. + +But again, it's just a reminder +of how powerful + +feelings and attitudes are, +whether they're in us or + +visited on us by the world, in +how well we perform, within + +the range of performance that +are within us to start with. + +I have two more points. + +So we talked a little bit about +entity versus growth. + +You know people who believe +they're like, I'm only so good + +at something. + +I'm only so good at basketball, +I'm only so good + +at math, I'm only so good at +programming, I'm only so good + +of writing, or whatever, versus +people who say, the + +harder I work, the +better I'll get. + +And that pretty much, this work +from Carol Dweck, that + +many people tend to go for +one thing or the other. + +Is it are we born with +talent and that's + +pretty much the deal? + +Or the harder we work, +do we get more + +talented at doing something? + +And so this is the kind +of questionnaire. + +And these are literally +questions, so she gives + +students, you have a certain +amount of intelligence and you + +really can't change it. + +I strongly agree. + +That's this trait model. + +Or I disagree. + +The harder I work, the +smarter I can be. + +And what she did for example, is +give that kind of question + +to students. + +And then follow them in their +performance on a math course. + +Here's the ones who believed +they could get better. + +Here's the ones who said they +only have so much math ability + +and intelligence. + +And look at the ones who thought +they could get better, + +got better. + +So that seems like a really +good thing to have, is not + +only the positive attitude. + +But a real belief that the +harder the work, the smarter + +you'll get. + +Last two slides. + +So finally, finally, finally. + +And we've had a couple of +them, but almost none, a + +longitudinal, random +assignment study. + +Which doesn't sound hugely +exciting, but that's the best + +science we can ever do. + +Randomly assign people +to things. + +And then follow them over time +to understand how life works. + +So one of the famous studies is, +this is Perry Preschool. + +So it followed into adulthood, +123 children from low SES + +environments in Michigan. + +And they were randomly divided, +randomly divided. + +And there's no randomness +right, in life, mostly. + +You're not randomly +given genes. + +You're not randomly put +into a household. + +It's always things are super +correlated with each other. + +And it's very hard to +tease them apart. + +But here they took kids who were +from poor families and + +put them randomly +into two groups. + +One group is a program group, +who received a high-quality + +active learning preschool +program and home visits, to be + +supportive as well. + +So they got help at home +and help in preschool. + +And a no-program group, who +didn't get any of these. + +I can tell you that when you do +random assignment studies + +in real life like this, some +people argue, I don't agreed + +with this, that it's unethical, +because you should + +help everybody all the time. + +But if you don't do this, +you never figure + +out what helps people. + +OK It's a little bit +of a circular-- + +you can't figure out what +really helps people. + +And then in a really rare +thing-- so it's random + +assignment. + +They followed them ages 3 to 11, +14 to 15, 19, 27, and 40. + +They follow you through +most of your + +childhood and adult life. + +So what happens? + +Here's their IQ scores? + +Here's the program people +in red and the + +no-program people in blue. + +And you can see that for a few +years, they separate by IQ. + +But by age 7, they're pretty +much the same. + +And when these kind of data came +out, because of course + +after the preschool, they +go back to their + +regular local schools. + +They're pretty much +the same schools. + +So people, after that they said, +well Head Start is a + +kind of a program to help kids +who are poor, get a head start + +in education and support. + +It's no good. + +It doesn't do anything. + +Because once they get back into +schools that not very + +supportive, the benefits of +the program disappear. + +You didn't do anything for the +kid, because unless you fix + +everything in their lives, that +one year just doesn't + +make a difference +in the long run. + +So everybody said, Head Start +programs are just, sadly, a + +waste of resources, because +they don't do anything for + +these children over +the longer term. + +But here's the remarkable +thing. + +They kept following +these kids. + +And here's what they found. + +For example, in the number of +arrests, 36 had five or more + +arrests in the program group. + +But all the way up to 55, for +the no-program group. + +That's a big difference, how +often you're arrested. + +That's a big outcome in life. + +Earning $20,000 or more at age +40, program group 60%; + +no-program group, 40%. + +Completed high school, +45% to 65%. + +20% increase in completion of +high school, from one year of + +help before kindergarten. + +Basic achievement at +age 14, way up. + +Willingness to do homework, +way up. + +So what's that's telling +us is, IQ is a + +pretty interesting thing. + +And we've talked +a lot about it. + +It is an interesting thing. + +But there's something really +deep in the ways you can help + +people, that make them +succeed in life. + +Not get in trouble, avoid bad +things, make money, finish + +school, do your work. + +That one year of school changed +these kids for the + +rest of their lives, +on average. + +And imagine if you had done +two years or five years? + +And IQ in this case doesn't +capture it at all. + +There's something else in them +that changed, that made them + +more resilient in life and +successful in the long run. + +So there's a lot of pieces to +who does well and not well in + +ways we wish for everybody. + +And IQ is a piece +of that story. + +But there's a lot of pieces. + +So thanks very much. \ No newline at end of file diff --git a/cQKR5m5pTTg.txt b/cQKR5m5pTTg.txt new file mode 100644 index 0000000000000000000000000000000000000000..099809edf1229d13945bb4c4af31064418110db4 --- /dev/null +++ b/cQKR5m5pTTg.txt @@ -0,0 +1,627 @@ +align:start position:0% + +we can get to documentation for the + + align:start position:0% +we can get to documentation for the + + + align:start position:0% +we can get to documentation for the +MATLAB Oh de suite by entering this + + align:start position:0% +MATLAB Oh de suite by entering this + + + align:start position:0% +MATLAB Oh de suite by entering this +command at the mat left prom doc Oh de + + align:start position:0% +command at the mat left prom doc Oh de + + + align:start position:0% +command at the mat left prom doc Oh de +45 this will bring us to extensive + + align:start position:0% +45 this will bring us to extensive + + + align:start position:0% +45 this will bring us to extensive +documentation for MATLAB ode45 that + + align:start position:0% +documentation for MATLAB ode45 that + + + align:start position:0% +documentation for MATLAB ode45 that +includes among other things this chart + + align:start position:0% +includes among other things this chart + + + align:start position:0% +includes among other things this chart +that compares MATLAB Oh de solvers there + + align:start position:0% +that compares MATLAB Oh de solvers there + + + align:start position:0% +that compares MATLAB Oh de solvers there +are seven of them and this compares + + align:start position:0% +are seven of them and this compares + + + align:start position:0% +are seven of them and this compares +their various attributes as we've said + + align:start position:0% +their various attributes as we've said + + + align:start position:0% +their various attributes as we've said +before MATLAB Oh de 45 is the workhorse + + align:start position:0% +before MATLAB Oh de 45 is the workhorse + + + align:start position:0% +before MATLAB Oh de 45 is the workhorse +it's a non stiff solver with medium + + align:start position:0% +it's a non stiff solver with medium + + + align:start position:0% +it's a non stiff solver with medium +accuracy that is the first one you + + align:start position:0% +accuracy that is the first one you + + + align:start position:0% +accuracy that is the first one you +should try and use it most of the time I + + align:start position:0% +should try and use it most of the time I + + + align:start position:0% +should try and use it most of the time I +have a soft spot in my heart for MATLAB + + align:start position:0% +have a soft spot in my heart for MATLAB + + + align:start position:0% +have a soft spot in my heart for MATLAB +oo de 23 it's a non stiff solver with + + align:start position:0% +oo de 23 it's a non stiff solver with + + + align:start position:0% +oo de 23 it's a non stiff solver with +low accuracy but its accuracy that's + + align:start position:0% +low accuracy but its accuracy that's + + + align:start position:0% +low accuracy but its accuracy that's +appropriate for graphics work because it + + align:start position:0% +appropriate for graphics work because it + + + align:start position:0% +appropriate for graphics work because it +chooses the step size it chooses R is + + align:start position:0% +chooses the step size it chooses R is + + + align:start position:0% +chooses the step size it chooses R is +appropriate for most graphics work + + align:start position:0% +appropriate for most graphics work + + + align:start position:0% +appropriate for most graphics work +MATLAB only e11 3 we haven't talked + + align:start position:0% +MATLAB only e11 3 we haven't talked + + + align:start position:0% +MATLAB only e11 3 we haven't talked +about it yet there should be a comma + + align:start position:0% +about it yet there should be a comma + + + align:start position:0% +about it yet there should be a comma +between the there could be a comma + + align:start position:0% +between the there could be a comma + + + align:start position:0% +between the there could be a comma +between the 1 and the 13 here because + + align:start position:0% +between the 1 and the 13 here because + + + align:start position:0% +between the 1 and the 13 here because +this is a variable order method where + + align:start position:0% +this is a variable order method where + + + align:start position:0% +this is a variable order method where +the order varies all the way from 1 to + + align:start position:0% +the order varies all the way from 1 to + + + align:start position:0% +the order varies all the way from 1 to +13 it's a multi-step method that saves + + align:start position:0% +13 it's a multi-step method that saves + + + align:start position:0% +13 it's a multi-step method that saves +history it's if you know about these + + align:start position:0% +history it's if you know about these + + + align:start position:0% +history it's if you know about these +things it's an atom's adams-moulton + + align:start position:0% +things it's an atom's adams-moulton + + + align:start position:0% +things it's an atom's adams-moulton +method i associate this with work done + + align:start position:0% +method i associate this with work done + + + align:start position:0% +method i associate this with work done +at Jet Propulsion Laboratory years ago + + align:start position:0% +at Jet Propulsion Laboratory years ago + + + align:start position:0% +at Jet Propulsion Laboratory years ago +for computing orbits of planets and + + align:start position:0% +for computing orbits of planets and + + + align:start position:0% +for computing orbits of planets and +satellites which of course are very + + align:start position:0% +satellites which of course are very + + + align:start position:0% +satellites which of course are very +smooth and go on for years + + align:start position:0% +smooth and go on for years + + + align:start position:0% +smooth and go on for years +if + + align:start position:0% +if + + + align:start position:0% +if +can have very high accuracy requirements + + align:start position:0% +can have very high accuracy requirements + + + align:start position:0% +can have very high accuracy requirements +then there are the stiff solvers there + + align:start position:0% +then there are the stiff solvers there + + + align:start position:0% +then there are the stiff solvers there +are 4 of them 1 5 s 2 3 s and the twins + + align:start position:0% +are 4 of them 1 5 s 2 3 s and the twins + + + align:start position:0% +are 4 of them 1 5 s 2 3 s and the twins +the trapezoid rules 1 5 s is the primary + + align:start position:0% +the trapezoid rules 1 5 s is the primary + + + align:start position:0% +the trapezoid rules 1 5 s is the primary +stiff solver low to medium active low to + + align:start position:0% +stiff solver low to medium active low to + + + align:start position:0% +stiff solver low to medium active low to +medium accuracy it's your first if you + + align:start position:0% +medium accuracy it's your first if you + + + align:start position:0% +medium accuracy it's your first if you +find no de 45 is slow taking lots of + + align:start position:0% +find no de 45 is slow taking lots of + + + align:start position:0% +find no de 45 is slow taking lots of +steps indication that the problem is + + align:start position:0% +steps indication that the problem is + + + align:start position:0% +steps indication that the problem is +stiff try 1 5 s 2 3 s can be is a law + + align:start position:0% +stiff try 1 5 s 2 3 s can be is a law + + + align:start position:0% +stiff try 1 5 s 2 3 s can be is a law +order method low accuracy and use that + + align:start position:0% +order method low accuracy and use that + + + align:start position:0% +order method low accuracy and use that +crude error tolerances we haven't talked + + align:start position:0% +crude error tolerances we haven't talked + + + align:start position:0% +crude error tolerances we haven't talked +about mass matrices this is where + + align:start position:0% +about mass matrices this is where + + + align:start position:0% +about mass matrices this is where +there's a matrix in front of the + + align:start position:0% +there's a matrix in front of the + + + align:start position:0% +there's a matrix in front of the +derivative term and this can be used + + align:start position:0% +derivative term and this can be used + + + align:start position:0% +derivative term and this can be used +with constant mass matrices and then the + + align:start position:0% +with constant mass matrices and then the + + + align:start position:0% +with constant mass matrices and then the +two routines with T's in their name are + + align:start position:0% +two routines with T's in their name are + + + align:start position:0% +two routines with T's in their name are +based on the trapezoid rule and there + + align:start position:0% +based on the trapezoid rule and there + + + align:start position:0% +based on the trapezoid rule and there +for use with problems without any + + align:start position:0% +for use with problems without any + + + align:start position:0% +for use with problems without any +numerical damping you can see the + + align:start position:0% +numerical damping you can see the + + + align:start position:0% +numerical damping you can see the +documentation for more details on the + + align:start position:0% +documentation for more details on the + + + align:start position:0% +documentation for more details on the +trapezoid methods + + align:start position:0% +trapezoid methods + + + align:start position:0% +trapezoid methods +that's the MATLAB o de suite 7 solvers 3 + + align:start position:0% +that's the MATLAB o de suite 7 solvers 3 + + + align:start position:0% +that's the MATLAB o de suite 7 solvers 3 +for non stiff problems and 4 for stiff + + align:start position:0% +for non stiff problems and 4 for stiff + + + align:start position:0% +for non stiff problems and 4 for stiff +problems you may well get through with + + align:start position:0% +problems you may well get through with + + + align:start position:0% +problems you may well get through with +never using anything but OD 45 may well + + align:start position:0% +never using anything but OD 45 may well + + + align:start position:0% +never using anything but OD 45 may well +serve all your needs there's a second + + align:start position:0% +serve all your needs there's a second + + + align:start position:0% +serve all your needs there's a second +chart in the documentation that + + align:start position:0% + + + + align:start position:0% + +summarizes all the options that are + + align:start position:0% +summarizes all the options that are + + + align:start position:0% +summarizes all the options that are +available through the Eau de CET + + align:start position:0% +available through the Eau de CET + + + align:start position:0% +available through the Eau de CET +function + + align:start position:0% +function + + + align:start position:0% +function +we've briefly mentions the tolerances + + align:start position:0% +we've briefly mentions the tolerances + + + align:start position:0% +we've briefly mentions the tolerances +rel tall and Abbe stall the output + + align:start position:0% +rel tall and Abbe stall the output + + + align:start position:0% +rel tall and Abbe stall the output +function these are available for in all + + align:start position:0% +function these are available for in all + + + align:start position:0% +function these are available for in all +seven of the solvers there are various + + align:start position:0% +seven of the solvers there are various + + + align:start position:0% +seven of the solvers there are various +other functions various other options + + align:start position:0% +other functions various other options + + + align:start position:0% +other functions various other options +available for more specialized work + + align:start position:0% +available for more specialized work + + + align:start position:0% +available for more specialized work +including event handling providing a + + align:start position:0% +including event handling providing a + + + align:start position:0% +including event handling providing a +Jacobian to the stiff solvers so they + + align:start position:0% +Jacobian to the stiff solvers so they + + + align:start position:0% +Jacobian to the stiff solvers so they +don't have to work so hard taking a + + align:start position:0% +don't have to work so hard taking a + + + align:start position:0% +don't have to work so hard taking a +numerical differences options associated + + align:start position:0% +numerical differences options associated + + + align:start position:0% +numerical differences options associated +with the mass matrices providing a limit + + align:start position:0% +with the mass matrices providing a limit + + + align:start position:0% +with the mass matrices providing a limit +on the step size these are all options + + align:start position:0% +on the step size these are all options + + + align:start position:0% +on the step size these are all options +that can be specified through o de set + + align:start position:0% +that can be specified through o de set + + + align:start position:0% +that can be specified through o de set +for more specialized work with the OD e + + align:start position:0% +for more specialized work with the OD e + + + align:start position:0% +for more specialized work with the OD e +solvers \ No newline at end of file diff --git a/e7Ptvu5Vu8k.txt b/e7Ptvu5Vu8k.txt new file mode 100644 index 0000000000000000000000000000000000000000..1898f160bee914dea0b4da46444f89af7f1fb3ac --- /dev/null +++ b/e7Ptvu5Vu8k.txt @@ -0,0 +1,3233 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Hello. + +Welcome. + +Welcome back from +spring break. + +Today what I want to do +is talk about op-amps. + +And in particular what I want to +do is talk about modularity + +in circuit design. + +How do you make circuits +that are modular? + +We'll see that there's special +problems when you think about + +modularity applied +to circuits. + +And op-amps are one solution +for helping us think about + +those problems. + +Before launching straight into +something new though, I'd like + +to recap where we are under the +assumption that you may + +not have been thinking about +this exactly currently. + +So last time we took our +first look at circuits. + +Circuits are very different from +the kinds of things we've + +thought about before. + +Before, in programming, in +linear systems theory, we + +thought about blocks that had +well-defined inputs and + +well-defined outputs. + +Circuits are different. + +Circuits are all connected +together. + +And circuit theory is thinking +about how do you organize your + +thoughts about complicated +interactions among things. + +The parts interact because they +touch each other and they + +share voltages. + +Because they touch each other, +they share currents. + +And you have to somehow +think about that + +whole complicated system. + +We figured out that the way you +think about that, you can + +think about it as three +separate enterprises. + +How do you think +about voltages. + +How do you think +about currents. + +And how do you think +about the elements. + +How do you think +about voltages? + +Well, the sum of the +voltages around any + +closed loop is zero. + +Done. + +KVL -- + +Kirchoff's Voltage Law. + +How do you think +about currents? + +Draw any surface. + +The net current that leaves +the surface is zero. + +KCL -- + +Kirchoff's Current Law. + +How do you think about +the elements? + +Well it depends on +the element. + +If you're thinking about a +linear resistor, it's Ohm's + +Law, V equals IR. + +If you're thinking about a +source, it could be a voltage + +source, then V equals v0, +some fixed number. + +If you're thinking about a +current source, then current + +is fixed at some fixed number. + +So it depends. + +When you're thinking about the +element laws, it depends on + +what element you are +thinking about. + +And then you just combine all +of those, and you can solve + +the circuit. + +The only problem that arises +is that those equations are + +highly redundant. + +There's a lot more KVL equations +than you need. + +There's a lot more KCL equations +than you need. + +And so in fact, the trick in +analyzing a circuit is to + +figure out the smallest number +of equations that are + +adequate, the number of +equations that are necessary + +and sufficient to +find a solution. + +Last time we went through three + +different ways to do that. + +We thought about what I will +think of as primitive or + +element voltages and currents. + +The idea in that technique is +you think about every element + +and assign to that element +its voltage and its + +corresponding current. + +Then that gives you, as in this +example if you've got six + +elements, that gives you six +unknowns, one voltage across + +every element, one current +through every element. + +So then you've got to dig up +six other relationships. + +Sorry, start again. + +Six elements, six voltages, six +currents, 12 unknowns, you + +need to come up with +12 equations. + +Six of them are element +equations. + +So six are easy. + +Then you have to come +up with six more. + +And for this particular circuit, +it turns out that + +there is three independent + +Kirchoff's Voltage Law equations. + +And there are three independent +KCL, Kirchoff's + +Current Law equations. + +12 equations, 12 unknowns +to solve, done. + +That's actually more work +than you need to do. + +So we looked at two other +techniques for solving the + +same kind of circuits. + +One's called node voltages +and another + +is called loop currents. + +They are duals of each other. + +In the node voltage method you +figure out exactly the minimum + +number of voltages that I would +have to tell you in + +order to specify all of +the element voltages. + +So for example, if I told you +this voltage here, and that + +voltage there, and this voltage +there, and that + +voltage there, four of them, +that would let you calculate + +all of the element voltages. + +But now I only have four +instead of six. + +Four nodes instead of six +element voltages. + +So it's smaller. + +And we talked about last time +how you could find the correct + +equations that go with +those node voltages. + +In the loop current method, you +specify the minimum number + +of currents that would be +sufficient to account for all + +of the element currents. + +And here in this circuit +it required three. + +Three is smaller than six. + +There were six element +currents. + +So again we've got a reduction +in the number of unknowns -- + +12 4, 3. + +So that's kind of the idea. + +And just to make sure that +you're all with it, think + +about this problem. + +How many of the following +expressions are correct? + +Feel free to talk to +your neighbor. + +At the end of about 45 seconds, +I'll ask you to raise + +your hand with a number of +fingers, (1) through (5) -- + +indicating which is the +correct answer. + +Dead silence. + +You're allowed to talk. + +OK, so how many of the +relations are true? + +Everybody raise your hand. + +Indicate a number fingers that +tells me how many of the + +answers are correct. + +Come on. + +Blame it on your neighbor. + +You can say anything, right? + +It's always your neighbor's +fault. + +That's very good. + +It's about 95% correct, +almost all correct. + +This first equation, +what is this? + +Give that a name. + +KVL. + +Is it correct? + +Sure. + +You need to figure out which +path it corresponds to. + +It goes through-- + +The only v's are over here. + +So therefore it must be +something that has to do with + +this circuit. + +So this says that there's +1, 2, 6, and 5. + +That's path 1, 2, 6, and 5. + +So all you really need to do +is check the polarities. + +So if we took all of the +variables to the same side, + +then we'd have minus v1 plus +v2 plus v6 plus v5. + +If we think about going a loop +that goes through the minus + +v1, that would be this way. + +Plus v2 plus v6 plus v5. + +So that's right. + +Easy. + +What's the point of +this equation? + +v6 equals e1 minus e2, +what's that say? + +Why'd I ask that? + +Yeah. + +AUDIENCE: It's saying +that the-- + +PROFESSOR: Exactly, it's +intended to make you think + +through the relationship +between the primitive + +variables, the element +voltages, + +and the node voltages. + +If I told you the node voltages +e1 and e2, you could + +trivially compute v6. + +You could also compute +any of the other v's. + +If I told you to find v-- + +what is that? + +My eyes are not very good. + +v4, if I told you to find v4, +that would be e1 minus ground. + +We assign the number 0 to +ground, so that would be e1. + +So the idea, the reason I ask +number (2), is to make you + +think about how you relate +the node voltages + +to the element voltages. + +How about number (3), +what's that? + +Well it's highly related +to number (2). + +But it's different from +number (2), because? + +AUDIENCE: Ohm's Law? + +PROFESSOR: Ohm's Law. + +So equation (3) is the way Ohm's +Law looks when you use + +node equations. + +Ohm's Law is a little bit +uglier when you use node + +equations than when you use +primitive variables. + +When you use primitive +variables, the same + +relationship would've simply +said that v6 is R6 times i6. + +Because I'm using node voltages +instead, the voltage + +across resistor six shows +up as a difference. + +How about this one? + +What's that? + +True or false, this is KCL? + +AUDIENCE: False. + +AUDIENCE: False. + +AUDIENCE: --KCL. + +PROFESSOR: True. + +This is KCL, true. + +OK. + +This is KCL, false. + +Well, obviously we're +numerous. + +And it's not, sort of, 100% +participation, but-- + +This is not KCL. + +What is that? + +KCL says that the sum +of current out + +of some closed path. + +This is mixed thing. + +i6 is one of these things. + +And IB and IC is one +of these things. + +So what is the equation for? + +AUDIENCE: Incorrect. + +PROFESSOR: Incorrect, yes. + +What would be the correct way +of saying equation (4)? + +AUDIENCE: i6 equals-- + +i6 is-- + +PROFESSOR: The answer to set +questions according to the + +theory of lectures is go +to the next slide. + +Here's the correct expression. + +Why is this correct, and why +is that not correct? + +Equation (4) is intended to be +how do you relate the loop + +current to the element +currents? + +So i6 is an element current. + +It's the current that +goes through R6. + +When we do loop currents, we +have two currents going + +through R6. + +So in the loop current view, +the total current that goes + +through R6 is a sum or +difference of the two loop + +currents that go through R6. + +So the element current through +R6, which is i6, is a sum or + +difference of loop currents. + +There are two loop currents +we have to worry about. + +Which one goes through in +the correct direction? + +i6 goes from left to right. + +So when we do the loop currents, +we need to take + +positive as the direction +from left to right. + +Well that's the direction of +IC and is the opposite + +direction of IB. + +So if I want to use loop +currents to specify i6, it + +would be IC minus IB. + +Everybody clear on that? + +So equation (4) is the relation +between element + +currents and loop currents. + +So what's equation (5)? + +Equation (5) is Ohm's Law +for loop currents. + +Again, if I were thinking about +Ohm's Law for R6, I + +would have v6 equals i6 R6. + +That's the way you say it in +element voltages and currents. + +Over here, the current through +R6 is IC minus IB. + +So Ohm's Law looks a little +bit more complicated. + +So the point is these three +methods represent ways of + +figuring out a linearly +independent set of unknowns + +and equations. + +They differ. + +The left hand one is probably +the easiest to think about, + +especially when you're +thinking about + +things like Ohm's Law. + +It's the natural way to +specify the element + +relationships. + +It's the relation between +the voltage and current + +through that part. + +That generally gives me +a large number of + +equations and unknowns. + +You can reduce the number of +unknowns by using something + +like node voltages +or loop currents. + +And that gives you fewer +equations to solve. + +They are completely +equivalent. + +They look a little different. + +And the reason for talking about +them is that when we + +think about writing a program +to solve circuits + +automatically, which by the way +will be the exercise in + +software lab this week. + +When we think about writing a +program, writing a program is + +yet a different kind +of challenge. + +What's the easiest system +to automate? + +So the system that is easiest +for you may or may not be the + +easiest system to automate. + +So that's the point of this +week's software lab. + +We'll do a method that's closely +related to the node + +voltage method. + +It's not quite node voltages. + +It's a little simpler than node +voltages for a computer. + +It's a little simpler +to automate. + +So we use a method that's called +node voltages with + +component currents. + +OK, now I'm going to +start new stuff. + +That was review. + +What I want to think about +today is what is it about + +circuit design that +makes it hard. + +What are the issues that make +it difficult to be modular + +when we're thinking +about the analysis + +and design of circuits. + +And one of the hardest things to +deal with is the idea that + +in a circuit, unlike in a linear +time invariant system + +of the type we talked about in +the previous module, in a + +circuit the presence of every +element affects the currents + +and voltages through, in + +principle, every other element. + +So if you change one thing, +you change everything. + +So first off, I want to just +give an example of that. + +Think about what would happen +if I were trying to make a + +circuit to control the +brightness of a light bulb. + +So I imagine that I've +got this circuit + +and I close the switch. + +Closing the switch is + +equivalent to adding a component. + +So before I close the switch, +when the switch was open, I + +have three elements, a voltage +source and two resistors. + +After I close the switch, I +have four elements, the + +original three plus the bulb. + +So the question is how would +closing the switch + +affect V0 and I0. + +Take a minute. + +Talk to your neighbor. + +Figure out how V0 +and I0 change. + +So what's the answer? + +Everybody raise your hand, show +a number of fingers equal + +to the answer. + +That's very good. + +It's 95% correct at +least, maybe 100. + +OK, so the answer is (2). + +Why is the answer (2)? + +How do I figure that out? + +AUDIENCE: So the total +resistance of the circuit is + +going to decrease because you're +adding it in parallel. + +And then V0 is going to decrease +because it's going to + +have a lower equivalent +resistance. + +And because that decreases, +you have I0 to-- + +PROFESSOR: Yes, I think that's +exactly correct. + +So the idea was that when +you add a component-- + +Let's think about the light +bulb being a resistor. + +That's kind of pulled out of +thin air, but I sort of + +suggested that you might +do that here. + +Think about representing the +light bulb as a resistor. + +Then when you close the switch, +these two resistors go + +in parallel. + +When you combine two things in +parallel, the result is the + +same as a resistance that +has a smaller value. + +And then think about how that +smaller value would interact + +with this resistor +and that source. + +And you can sort of figure out +that the presence of this bulb + +would reduce this voltage and +increase that current. + +That's kind of a high level of +reasoning given where we are. + +If you wanted to think through +this a little more step by + +step, it's easy. + +You could think about figuring +out what are the voltages and + +currents before and after +you close the switch. + +Before you close the switch, you +can just ignore this, and + +you can calculate V0 just +from a voltage divider + +relationship. + +Right, that's clear? + +So you can see that when the +switch is open, the voltage, + +V0, is going to be 8 Volts. + +And when the switch is open, +you can figure out I0 by + +lumping these two resistors +together to + +make a 3 Ohm resistor. + +And you see that I0 is 4 Amps. + +Then to figure out what happens +when you close the + +switch, just repeat. + +And the algebra is a little +more tedious. + +I won't try to go through it. + +By the way, the answers, the +slides that I show in lecture + +are always posted on the web. + +So these slides that have the +answers, they are there. + +On the web there are two +handouts per lecture. + +There's an electronic +version of the thing + +that we handed out. + +There's also an electronic +version of my slides. + +So everything that I +showed is there. + +I'm not going to go through +the tedious algebra. + +It's just tedious algebra. + +But if you go through the +tedious algebra, you find that + +if you represent this bulb by +resistor R, V0 becomes an + +expression that looks +like this. + +If you think about resistors, +physical resistors, if you + +think about light bulbs being +represented by a physical + +resistor, then the physical +resistor has to have a + +resistance between +0 and infinity. + +And if you think about that +expression, what could the + +value be if R varied between +0 and infinity? + +That expression is always less +than or equal to 8 Volts, + +showing that V0 went down when +you closed the switch. + +Similar tedious algebra leads to +an expression like this in + +R. And if you think about how +this would change as R goes + +from 0 to infinity, you +see that that's always + +bigger than 4 Amps. + +So that means I0 goes up. + +So the point is you can think +through this in a more + +sophisticated way. + +And we hope by the end of +the course you'll all + +be able to do that. + +Or you can think through +it in terms of + +just solving the circuit. + +Solve it in two cases when the +bulb is there and when the + +bulb is not. + +Either way, the answer is (2). + +The V0 went down, +and I0 went up. + +The point is that when I added +the element, currents that + +were far away from the element +still changed. + +And that's a general way +circuits interact. + +They're all connected. + +So the idea, the point of +doing this is that the + +addition of a new element +changed the voltages and + +currents through the +other element. + +That's a drag if what I was +trying to do, for example, was + +design a brightness controller +for the flashlight bulb. + +Imagine that what I really +wanted to do was use a voltage + +divider to make 8 Volts. + +And what was in my head was I'd +like that 8 Volts to be + +across the light bulb. + +That's a good idea. + +It just won't work. + +At least It won't work the +way this circuit worked. + +If I just build it like so, +there's an interaction between + +the bulb and the voltage divider +circuits, so the + +voltage divider circuit is no +longer a voltage divider. + +After, in this circuit, when +I close the switch, current + +flows in this wire. + +The rule in a voltage divider +is the same current has to + +flow through both resistors. + +If the same current flows +through two resistors, then + +you can use the voltage divider +relationship to see + +how voltage partitions between +the two resistors. + +If current gets siphoned off +the node between the two + +resistors, you can't +use the voltage + +divider relation anymore. + +That violates the premise of the +voltage divider relation. + +So when I close the switch, this +is no longer a voltage + +divider, and it no longer works +like a voltage divider. + +Is that clear? + +So what I'd really like is some +magic circuit that I can + +put here that isolates the +effect of the bulb on the + +effect of the rest +of the circuit. + +And that's exactly what +an op-amp does. + +That's what we're going +to talk about next. + +So this magic circuit +is something that + +we'll call a buffer. + +A buffer is a thing +that isolates the + +left from the right. + +So the buffer is going to be +something that measures the + +voltage on this side and +magically generates that + +voltage over here without +changing this side. + +So what we want to do now is +develop some thought tools for + +how you think about op-amps. + +Op-amps are different. + +And if you just look at the +picture, op-amp has to be + +different because there's +too many terminals. + +It's not like a resistor +that has two legs. + +It's not like a V source +which has two legs. + +It's not like an I source +which has two legs. + +It has three legs. + +In fact, I haven't drawn +all the legs. + +There's more than three. + +There's at least five. + +So they're different. + +And the way we think about +them are different. + +The key to thinking about the +way an op-amp works is to + +think about a new class +of elements + +called controlled elements. + +So a controlled element is an +element whose voltage current + +relationship depends somehow +on a voltage and current + +measured someplace else +in the circuit. + +As an example, think +about a current + +controlled current source. + +That's depicted here. + +I would normally +write a current + +source that was a circle. + +That means it's an independent +current source. + +That means that the +current is fixed. + +The little diamond thing is my +way of representing the idea + +that the amount of current that +comes out of this current + +source depends on +something else. + +In this case it depends on IB. + +And IB happens to be a current +that flows in that circuit. + +So the idea is that the current +in the current source + +depends on some other current. + +It's a current controlled +current source. + +It's a current source whose +current is controlled by + +another current. + +Got it? + +So we'll see. + +Figure out, for this current +controlled current source + +circuit, what's the ratio +of Vout over Vin? + +So what's the answer? + +What's the ratio of +Vout over Vin? + +100%, wonderful. + +The answer is (4). + +Easy to get. + +It's easy to get because +I rigged this + +question to be easy. + +I rigged it to be easy because +you can sort of figure out + +everything that's going +on on the left. + +And then you can figure +out everything that's + +going on on the right. + +And so there's no sort +of complicated + +coupling between the two. + +So what's going on on +the left, well, you + +can solve for IB. + +IB is just Vi over 1,000 Ohms. + +Then you can take that value +of IB and use that to solve + +for what's going on over here. + +Over here the out is this +current, 100 IB times this + +resistance, 5 Ohms. + +But we just found out that +IB is VI over 1,000 Ohms. + +Substitute it in, +you get half Vi. + +So the answer is number (4). + +The ratio of Vout to +Vin is a half. + +So the point is these are a +different kind of element, + +controlled sources, +dependent sources. + +But they're not too +hard to work with. + +They sort of look different +structurally. + +So think about what's +going on here. + +The controlled current source, +the current controlled current + +source, I have to think of that +as a box, because the + +current source has to know +the value of IB. + +So somehow this box, this +thing that's doing this + +current controlled current +source, it knows about IB, and + +it knows about the +current source. + +So they're somehow linked. + +So that's why I put +a box around it. + +And then think about the +equations that characterize + +that component. + +So now we've got a component +that's got four wires + +coming out of it. + +The components we had before +had two wires coming out of + +them, resistors, current +sources, voltage sources. + +This kind of a component has +four wires coming out of them. + +We call this kind of a component +a two-port because + +we think of the left port +and the right port. + +That's compared to resistor, +which we + +would call a one-port. + +We think about this +being a two-port. + +And there's now two equations. + +Now I've got, for that two-port, +I've got two + +voltages and two currents. + +There's the voltage across +the left part. + +And there's the voltage +across the right part. + +And there's current through +the left part. + +And there's the current through +the right part. + +So with the elements we've +thought about before, I had + +one voltage across it and +one current through it. + +Now I've got two voltages across +it and two currents. + +It's kind of twice as big. + +Not surprisingly, it takes +twice as many equations. + +Ohm's Law was a single +equation for + +one resistor, a one-port. + +V equals V0 was one +equation for one + +component, a voltage source. + +Here, I've got one component +that has + +four wires, four unknowns. + +And I get two equations. + +So for this particular dependent +source, I know that + +the voltage across this pair +of terminals is 0, because + +it's essentially a short circuit +between the two. + +Short circuit just means +connected with a wire. + +And I know that the current I2 +is related to the current over + +there this way. + +The idea then is that this +current controlled current + +source can be represented by a +two-port, two voltages, two + +currents related by +two equations. + +It's kind of structurally twice +as difficult to think + +about as a one-port. + +Functionally, it's different +from having two one-ports, + +because the two one-ports +are coupled. + +And that's the important part +is the coupling between the + +two that you can't model with a +simple resistor and a simple + +constant source. + +So when we think about an +op-amp, a good first model for + +an op-amp is to think about +it as a voltage controlled + +voltage source. + +And so that's depicted here. + +I want to think about the +op-amp, which I'll + +symbolically write this way. + +This means something that has +two inputs, a plus input and + +then a minus input, and +a single output, Vout. + +I can think about +it as a voltage + +controlled voltage source. + +This I mean to be the element +representation. + +This is how I'll draw it +when I make a schematic + +diagram of a circuit. + +This is the functional form. + +This is the way I'll +think about it when + +I'm analyzing it. + +I'll think about the op-amp as +being a voltage controlled + +voltage source. + +This voltage source adopts a +voltage that is some number K + +times the difference voltage +Vplus minus Vminus. + +And the trick in op-amps is that +K is typically a very big + +number, typically bigger +than 10 to the 5th. + +We'll see in a minute +why that's a + +frightfully useful component. + +Let's just walk through an +example to see how you would + +solve a circuit that has this +kind of a voltage controlled + +voltage source in it. + +So think about this circuit +where I'm applying a voltage + +to the plus lead of an op-amp, +and I'm wrapping the output + +back through the minus lead, +through two resistors. + +And what I want to do is +analyze that circuit by + +thinking about the op-amp +as a voltage + +controlled voltage source. + +So I can see just by the way +it's wired up that the voltage + +at the plus lead-- + +So I'm going to be thinking +node voltages. + +Node voltages tend to be easy. + +I'm thinking node voltages. + +So I'm going to define +all my voltages + +referenced to a ground. + +So I'll call this node ground. + +That's what the funny +symbol means. + +Then this node voltage, the +voltage at the plus terminal, + +is just the same as +the input voltage. + +This voltage at the minus +terminal looks like a voltage + +divider relationship. + +If you look at my model, it's +very clear that I1 is 0, + +because there's no connection +here between the + +Vplus and the Vminus. + +So I1 is 0. + +That means the total current +that flows into the plus lead + +of the op-amp is 0. + +The total current that flows +into the minus lead of the + +op-amp is 0. + +So because there's no current +flowing in the plus and minus + +leads, I can calculate the +voltage at this minus terminal + +as a voltage divider. + +And it's just R1 over the sum +of R1 and R2 times V0. + +Then according to the voltage +control voltage source model, + +Vout should be K times +the difference + +between Vplus and Vminus. + +So I just substitute in for +Vplus -- this guy, Vi, and for + +Vminus -- this guy. + +Do some algebra. + +I get this expression +after some algebra. + +And then I say, yeah but I +know that K's really big. + +So if K's really big, KR1 +is big compared to R1. + +So I can ignore that. + +In fact, K is so big that for +any reasonable choice of R1 + +and R2, KR1 is even +bigger than R2. + +So that means this reduces to +this kind of a fraction. + +So the response of this circuit, +this op-amp circuit-- + +So what did I do? + +I just took the op-amp circuit, +and I modelled it as + +a voltage controlled voltage +source, plugged through the + +equations, and found out that +the ratio of the output + +voltage to the input voltage +is R1 over R1 plus + +R2 divided by R1. + +So the idea then is that +this simple circuit + +works like an amplifier. + +It's an amplifier in the sense +that I can make the output + +voltage bigger than +the input voltage. + +That's a very useful thing. + +In fact you'll find useful ways +to use that when you do + +the design lab this week. + +So this as an amplifier. + +So here's a question. + +Make sure you follow +what I just did. + +How could I choose the +components R1 and R2 so that I + +make Vout equal to Vi? + +AUDIENCE: Why is this 0? + +PROFESSOR: There's no +wire connecting. + +AUDIENCE: Oh. + +PROFESSOR: So there's nowhere +for current to go. + +OK so how would I choose the +components R1 and R2 in order + +to make the output voltage equal +to the input voltage? + +Wonderful. + +So the idea is that all of these +manipulations have the + +same effect. + +All you need to do +is look at the + +expression that we developed. + +The expression was R1 +plus R2 over R1. + +If you substitute, R1 goes to +infinity, R2 equals 0, or the + +two at the same time, you get +one in all of those cases. + +So that's a way that you can +turn this amplifier circuit, + +that in general would make the +output bigger than the input, + +into something that makes the +output equal to the input. + +Now I want to turn to +a simplification. + +I just dragged you +through the math. + +Thinking about the op-amp as a +voltage controlled voltage + +source, there's actually +a shortcut. + +The shortcut is something we +call the ideal op-amp. + +So what I want to do in this +slide is drag you through the + +math one more time, but +then we're done. + +The idea is that if you have +an op-amp, a voltage + +controlled voltage source, if +you represent an op-amp as a + +voltage controlled voltage +source, and if K is very big, + +the effect will be to make the +difference between the + +positive and negative +terminals of the + +op-amp quite small. + +You can see that here by way +of a simple example. + +So let me think about this case +with, again, the voltage + +controlled voltage +source model. + +So here I've got Vout. + +According to the voltage +controlled voltage source + +model, Vout should be K +times the difference + +between the two inputs. + +The positive input +is clearly Vi. + +The negative input is Vo. + +One equation, two unknowns, +solve for the ratio. + +The ratio of Vout to Vi +is K over (1 plus K). + +That's the answer. + +Take that answer and back +substitute to figure out how + +big was the difference between +Vplus and Vminus. + +That's just algebra. + +And what you see is that if this +is the answer, then Vplus + +minus Vminus can be written as +a fraction of Vi or a similar + +fraction of Vo. + +K is big. + +K is essentially the +same as K plus 1. + +K is in the denominator +of both. + +What that says is the difference +between the plus + +and the minus leads, the voltage +between the plus and + +the minus leads, is very small +if K is very large. + +OK? + +So we call that the ideal +op-amp relationship. + +The utility of that is that it +makes solving the op-amp + +circuits much, much +easier than what + +we've just been doing. + +I've been solving the circuits +by thinking about the op-amp + +as a voltage controlled +voltage source. + +That's fine. + +But if I additionally know +that K is very big, I can + +shortcut it. + +I can say, look, the effect of +the op-amp is going to be to + +make the positive and negative +inputs the same. + +If it didn't do that, think +of what it would mean. + +If K is a big number, and if the +output voltage is K times + +the difference, if the +difference is anything other + +than epsilon, Vout has +to be infinity. + +I mean if K is very +big, right? + +If K is very big, the only way +the output could be some + +reasonable number like a Volt +would be if the difference + +between Vplus and Vminus +is very small. + +OK, well let's work backwards. + +Let's start with the assumption +that Vplus minus + +Vminus is very small. + +And that lets us solve the +circuits very quickly. + +So for example, the same circuit +that took, previously, + +a few lines to get the answer +to, if I just take as a rule + +that Vplus has to be Vminus, +it's a one step. + +Vplus equals Vminus, OK, Vi +equals Vo, period, done. + +It's a very simple way to think +about the answer to an + +op-amp circuit. + +So if the op-amp can be +represented by a voltage + +controlled voltage source and if +K is very large, then Vplus + +is roughly Vminus. + +Shortcut, ideal op-amp +assumption. + +So, use that or ignore +it depending on + +what your mood is. + +And figure out the voltage +relationship for this slightly + +more complicated circuit. + +So what's the answer? + +Yes? + +No. + +How many are done? + +How many are not done? + +OK, take a minute. + +This is supposed to be easy. + +Think ideal op-amp. + +OK, what's the output? + +Everybody raise your hand, +what's the output? + +More hands, more hands, +more hands. + +OK, tiny number of hands, but +those who showed hands are + +about 100% correct. + +I don't know how +to grade that. + +Small participation, 100% +among those who did + +participate. + +So how do I think about this? + +What's step (1)? + +All right, according to the +theory of lectures, + +what is step (1)? + +AUDIENCE: Look at the +previous slide. + +PROFESSOR: Look at the +previous slide, yes. + +What was the previous slide? + +OK The previous slide +had to do with? + +AUDIENCE: The ideal op-amps. + +PROFESSOR: Ideal op-amps. + +What's ideal op-amps say? + +Vplus equals Vminus. + +What happens here if Vplus +is equal to Vminus? + +Well what's Vplus? + +AUDIENCE: 0. + +PROFESSOR: So what's Vminus? + +AUDIENCE: 0. + +PROFESSOR: 0. + +So if Vminus is 0, +what do I do now? + +That bad, that hard huh? + +Well, I got a [UNINTELLIGIBLE] +here in which three different + +currents can flow. + +How big is the current that +can come into this node? + +What's the sum of all the +currents that can + +come into that node? + +Well one could come +in this way. + +One could come in that way. + +One could come in that way. + +How much current flows in the +minus lead of the op-amp? + +AUDIENCE: 0. + +AUDIENCE: 0. + +PROFESSOR: None. + +No current goes into +the minus. + +No current enters the op-amp +through the minus lead. + +So it's the sum of +three currents. + +How big is this current? + +How big is the current that +flows in that lead? + +V1 -- + +V1 over 1, right? + +Ohm's Law. + +So this node is 0. + +That node is V1. + +The voltage across this resistor +is V1 minus 0. + +The voltage across is V1. + +The current is V1 +over R. R is 1. + +So the current that flows +in this leg is V1. + +How much current flows +in this leg? + +How much current flows +in this leg? + +AUDIENCE: V0. + +PROFESSOR: V0. + +The idea is that the total +current that flows into this + +node is V1 plus V2 plus V0. + +Solve for V0. + +V0 is minus V1 minus V2. + +Right? + +Got it? + +The idea was that this is really +easy to solve if you + +use the ideal op-amp +approximation. + +You can see that this is 0. + +Therefore, this is 0. + +So you have a single +KCL equation. + +And the result is that this +circuit looks like an + +inverting summer. + +It computes the sum of V1 and V2 +and then takes the negative + +of that and presents +that at the output. + +What I'm trying to motivate is +that there's a whole different + +level of reasoning that you +can do when you have this + +element, which is an op-amp. + +Here what we've done is we've +made something that performs a + +numerical operation. + +It presents, at the output, +the negative + +sum of the two inputs. + +OK another problem. + +Determine R so that V0 +is twice V1 minus V2. + +So how should I choose R? + +Not very many hands. + +This is the perfect nano +quiz practice, right? + +This looks like a perfect nano +quiz question, right? + +Smile. + +So what's the answer? + +OK we're down to about +half correct. + +This is harder. + +Basically you do exactly the +same thing, it's just that + +it's a little algebraically +messier. + +So not surprisingly, the first +idea is to think about the + +ideal op-amp. + +We'll think about what was the +voltage here, what was the + +voltage there, and then +we'll equate them. + +What's the voltage +at the plus lead? + +Well that's easy. + +That's just a voltage +divider here. + +Since no current flows in +here, I can compute the + +voltage relative to this ground +as R over (1 plus R). + +That's showed here. + +Times V1. + +This one's a little bit trickier +because I've got two + +sources, V2 and V0, +each pumping + +current into this place. + +The way I thought about it was +start with V2 and then add to + +it this component, which can +be thought of as a voltage + +divider here. + +So how big is the voltage +at Vminus? + +Well it's V2 plus a voltage +divider here, + +which is given by this. + +That's a little tricky. + +If you're not comfortable with +that step, you could also + +solve for that voltage using +the node method. + +The node method will give +you the same answer. + +The answer is that the voltage +at the Vminus port is two + +thirds of V2 and one +third of V0. + +That sort of looks right because +the resistors are in a + +ratio of 2:1. + +And then using the ideal op-amp +assumption, we equate + +the two, do some more algebra, +and we get some relationship + +and figure out that R is 2. + +The point is that this is a + +relatively complicated circuit. + +You could have done it if I had +asked you to do it with + +the voltage controlled +voltage source model. + +But the algebra is already +hard here with the ideal + +op-amp assumption, and with the +voltage controlled voltage + +source it's even harder. + +So the idea is that the ideal +op-amp assumption, the idea + +that Vplus is equal to Vminus, +makes the work of calculating + +these responses significantly +easier. + +Everybody's with the +bottom line? + +We started with the idea that +when you add an element to a + +circuit, in general, adding an +element changes voltages and + +currents throughout +the circuit. + +We wanted a way to make the +design more modular, a way of + +adding a component without +changing everything else. + +We thought about this +op-amp thing. + +The model for the op-amp +was voltage + +controlled voltage source. + +We inferred this ideal +op-amp model. + +The ideal op-amp model +was great for + +calculating the response. + +It has this one problem. + +It seems to say these circuits +are identical. + +If I literally believe the ideal +op-amp assumption that + +all the op-amp does is magically +make the plus and + +minus terminals the same, I +would conclude that this + +circuit where the input comes +in the plus and the output + +wraps around to the minus +generates precisely the same + +input-output relationship as +this one, where the input + +comes in the minus and the +output wraps around the plus. + +The ideal op-amp assumption +simply says for both of those, + +Vi equals Vo. + +So I would assume from the ideal +op-amp model I get the + +result that these two circuits +work exactly the same way. + +Somehow that sounds wrong. + +I've got this part, and +I can wire it up the + +right way and it works. + +Or I can flip the two wires, +and it still works. + +Conservation of badness +doesn't let + +that happen, right? + +If you do something bad, +it should break. + +The ideal op-amp assumption +seems to + +lead to a bogus result. + +It seems to say these +two are the same. + +So what I'd like to do is think +about that for a moment. + +We want to be comfortable with +the assumption that we make. + +The ideal op-amp assumption +makes analysis really easy, + +but we'd like to understand +exactly what we're assuming. + +This just doesn't sound right. + +OK, so let's back up. + +Let's not do the ideal +op-amp assumption. + +Let's Instead say that we use +the voltage controlled voltage + +source model. + +So what I've done here +is substitute + +into the left circuit. + +So this circuit is shown here +and the other over here. + +All I've done is connected the +input either to the plus or to + +the minus port and wrapped +the other one around. + +But now I'm analyzing it using +the voltage controlled voltage + +source model. + +And I've done the +tedious algebra. + +And I don't think there's +any mistakes + +in the tedious algebra. + +In one case I get K over +(1 plus K), which for + +large K is about 1. + +In the other case I get minus K +over (1 minus K), which for + +K large is about 1. + +The ideal op-amp assumption says +that it doesn't matter. + +The voltage controlled +voltage source model + +says it doesn't matter. + +And Freeman thinks this doesn't +make any sense. + +So what's going on here? + +What's going on is that we've +actually made an enormous leap + +in thinking about the op-amp +even as a voltage controlled + +voltage source. + +The two models that we talked +about, the voltage controlled + +voltage source and the ideal +op-amp model, are great for + +calculating answers. + +They are not so good at +providing a mechanism for how + +the op-amp is actually +working. + +Think about just the ideal +op-amp assumption. + +It's great to think, OK, the +op-amp is going to do whatever + +magic is necessary to make +these two leads the same. + +Well how does it do that? + +The thing about the ideal op-amp +assumption is that it + +doesn't tell you the mechanism +by which that happens. + +What does the op-amp actually +do in order to get + +Vplus equal to Vminus? + +What's actually going on +inside the op-amp? + +The ideal op-amp assumption is +very good for analysis and not + +very good with mechanism. + +What's the mechanism? + +What's the op-amp +actually doing? + +What it's really doing is +moving charge around. + +8.02 -- + +charge. + +So if you're going to have a +change in voltage, there has + +to be motion of charge. + +And that's what's missing from +the voltage controlled voltage + +model and from the ideal +op-amp model. + +How do you think about +moving charge around? + +Well it's the same as +moving water around. + +Somehow, I think it's all those +years of playing with + +water when I was a little kid, +I find my intuition about + +water is better than my +intuition about charge. + +So let me start by thinking +about the intuition for water. + +The way a water tank works is +if the flow in is different + +from the flow out, the +height changes. + +That's continuity. + +So if the water is conserved, +if there's not significant + +evaporation over the duration +of this experiment, or if + +molecules of water do not +spontaneously disappear or + +appear, under either of those +two assumptions, then the + +change in the height is +proportional to the difference + +between the rate at which it's +coming in and the rate at + +which it's coming out. + +If the rate at which it's going +out is equal to the rate + +at which it's going in, there's +no change in height. + +If it's coming in faster, +it's going up. + +If it's coming in slower, +it's going down. + +All easy, right? + +Charge works the same way. + +The thing that accumulates +charge in an electronic + +circuit is a capacitor. + +And there's a direct analogy +between thinking about the way + +the flux of water generates +height and the way flux of + +charge generates volts. + +So we can think about the flux +of charge, that's current. + +If there's a net flux, if +there's a bigger current into + +a capacitor then there is +out, the voltage on that + +capacitor goes up. + +If there's a smaller current in +than goes out, the voltage + +on the capacitor goes down +just like the height + +in a tank of water. + +We can make a much more +realistic model for the way an + +op-amp works by explicitly +making a representation for + +how the charge flows. + +And that's shown here. + +I'm going to take the voltage +controlled voltage source + +model but explicitly make a +representation for the output + +charging up. + +What's the op-amp do? + +The op-amp senses the voltage +at the input and the output + +and does something to change +the voltage at the output. + +The thing it does is if the +positive voltage is greater + +than the negative voltage, +it pumps charge + +into the output node. + +If the opposite occurs, +it sucks charge out. + +Now it's important, this is not +an accurate depiction of + +what's inside an op-amp. + +This is the model +for an op-amp. + +I don't want to lead any of +you to think that this is + +literally what's in an op-amp. + +This is not literally +what's in an op-amp. + +Here is much more literally +what's in an op-amp. + +This is the schematic +diagram of a 709 + +which is a Widlar circuit. + +It's a complicated transistor +circuit. + +It's ingenious. + +This is how you build a +circuit that has the + +remarkable property of the +ideal op-amp circuit. + +It's not perfectly obvious +from here. + +And even here this doesn't give +Widlar enough credit. + +Here's what he really did. + +He designed masks to shield +semiconductor materials so + +that you could turn them into +transistors so that it would + +turn into an op-amp. + +We're not going to +worry about this. + +This is two levels of +abstraction more complex than + +we're going to worry about. + +We're just going to say, I don't +know what's in there, + +but this is the way +it behaves. + +This is intended to be a +behavioral model for how an + +op-amp works. + +And in fact, that's +an important + +idea that we use circuits-- + +I use circuits on a daily basis +not because I design + +semiconductor devices +but because I work + +on biological issues. + +I actually study hearing. + +And we make circuit models for +the way biological parts work. + +And that helps us to understand +the way the + +biological part works. + +For example, here is a model +taken from 6.021, where we try + +to understand how a nerve +propagates an action potential + +by making a circuit model. + +That's the same thing +we're doing here. + +We're making a circuit model +for how the op-amp works. + +it's not intended +to be literally + +what's inside the op-amp. + +It's intended to be a model that +let's us think about the + +behavior of the op-amp. + +This lets us understand now why +it's different when you + +flip the wires. + +Let's start with the original +configuration where I put the + +voltage in the plus lead, and I +wrap the output back around + +to the minus lead. + +What's going to happen? + +What's the op-amp actually do? + +Imagine that things +had been stable. + +This was 0. + +The output was 0. + +Everybody was happy. + +And now all of a sudden the +input voltages steps up. + +What happens? + +The input voltage steps up. + +The voltage source suddenly +generates a + +huge positive voltage. + +And that starts to put current +into the capacitor that + +represents the voltage at the +output of the op-amp. + +So as a result of this voltage +being higher than where it + +was, current is being dumped +by the op-amp into this + +capacitor, and the output +voltage starts to increase. + +That's shown it red. + +As the capacitor voltage gets +bigger, as the output voltage + +increases, the difference +between Vplus and Vminus gets + +smaller, and the rate at which +charge is flowing into the + +capacitor slows. + +And in fact, as the voltage at +the output gets very close to + +the voltage at the input, the +rate of current into the + +capacitor goes to 0. + +And the output voltage +stabilizes + +at the input voltage. + +The same thing happens in +reverse if I were to change + +input voltage and make +it go negative. + +If the input voltage went +negative, then K times Vplus + +minus Vminus would be a big +negative number and it would + +suck current out. + +The voltage controlled voltage +source would suck current out + +of the capacitor and make +the voltage fall. + +The voltage would fall. + +The absolute difference between +the plus and minus + +port would get smaller. + +The current flowing +would become less. + +And it would again stabilize +when the output is + +equal to the input. + +Contrast that to what would +happen if I put the input into + +the minus port. + +If I put the input into the +minus port, and the input goes + +through a step, then the input +going positive makes the + +voltage controlled voltage +source generate a + +big negative voltage. + +It sucks current out. + +So the input went positive. + +And the output goes negative. + +It goes the wrong way. + +That's bad. + +So here, if I put the input +into the minus lead, a + +positive transition of the +input leads to the output + +going the wrong way. + +And as it goes the wrong way, +the drive to make it go the + +wrong way gets bigger. + +It's a runaway system. + +It's positive feedback. + +So the idea is that by +supporting the input into the + +negative lead instead of into +the positive lead, leads to a + +positive feedback situation in +which a small change at the + +input makes the output go the +wrong way, convinces the + +op-amp that things are getting +worse, so it makes even more + +current, which makes it go +even more the wrong way. + +And the same thing happens +with the flip situation. + +The idea then is that +by thinking + +about the flow of current-- + +What's the op-amp +actually doing? + +The op-amp is actually sensing +the difference between the + +voltage at the positive port and +the minus port, and it's + +sourcing current that +changes the output + +voltage to go up or down. + +You need to wire the op-amp so +that ultimately the output + +equals the input. + +Otherwise the ideal op-amp +condition that Vplus equals + +Vminus will ever be attained. + +So the left one is what we would +refer to as a stable + +feedback situation. + +You can think about that as +analogous to thinking about a + +ball in a valley. + +So we have a valley, +and we have a ball. + +The ball's going to roll +down here eventually. + +It's stable. + +Bop it a little bit to the +right, it'll roll back into + +the valley. + +Bop it a little to the +left, it'll roll + +back into the valley. + +That's as opposed to, when we've +wired up the wrong way, + +it's like we have an unstable +equilibrium. + +It's as though we're trying +to put the ball there. + +Bop it a little to right, it +runs away to the right. + +Bop it a little to the left, +it runs away to the left. + +That's unstable. + +There is a metastability +plane. + +If you actually balanced it +exactly, exactly, exactly at + +the right place, it +would stay there. + +That's what the solution +is telling you. + +That was the minus K +over (1 minus K). + +The fact that the equations +had a solution is correct, + +it's just an unstable +solution. + +The tiniest little disturbance +will make it go awry. + +The idea then is that +the ideal op-amp + +assumption is fine. + +It's a good thing to use. + +It doesn't tell you about +the mechanism. + +If you think a little bit more +about the way the physics + +works, you have to wire the +circuit up so that it has + +negative feedback in order to +get a stable equilibrium. + +So if you understand that, and +you just make sure that you've + +hooked it up so that it has +negative feedback, then you + +can use the ideal op-amp +assumption. + +Everything's just fine. + +And in the interest of time, +I'm going to just skip over + +this because we've already +talked about all of this. + +It's just another example. + +The last thing I want to mention +is just that in order + +to work this magic, +the op-amp has to + +get power from somewhere. + +And so that means that it's not +a three-terminal device. + +It's not the kind of device I've +been drawing so far that + +has got power pins too. + +The way the op-amp works is it +takes power from those power + +pins to be able to force the +output to a voltage that'll + +make the input the Vplus +equal to Vminus. + +That's the mechanism +by which it works. + +And that'll have important +consequences when we build the + +robot head, because what it +means is that we're not going + +to be able to generate arbitrary +voltages at the + +output of an op-amp. + +We're going to be limited to +generating voltages that are + +between the power rails. + +So if we were to supply plus +and minus 10 Volts to the + +power pins, we would not be +expecting to be able to + +generate 20 Volts +at the output. + +So that's an important +implication when we do the + +design lab. + +In summary, what we've done is +we've showed how circuits can + +be a pain to make modular, +because in principle, adding + +one component changes voltages +and currents everywhere. + +But there's a way using op-amps +to have this buffering + +idea that lets us logically +separate parts of circuits so + +the one can control the other. + +Have a good day. \ No newline at end of file diff --git a/eRFQL3o4DO4.txt b/eRFQL3o4DO4.txt new file mode 100644 index 0000000000000000000000000000000000000000..094c05061bcccbeab7713c9240d3a1af5b42f87d --- /dev/null +++ b/eRFQL3o4DO4.txt @@ -0,0 +1,1835 @@ +align:start position:0% + +so let's try to do return to to seeing + + align:start position:0% +so let's try to do return to to seeing + + + align:start position:0% +so let's try to do return to to seeing +okay we solve the equation we we seem to + + align:start position:0% +okay we solve the equation we we seem to + + + align:start position:0% +okay we solve the equation we we seem to +be okay what did we really approximate + + align:start position:0% +be okay what did we really approximate + + + align:start position:0% +be okay what did we really approximate +we didn't approximate saying h-bar goes + + align:start position:0% +we didn't approximate saying h-bar goes + + + align:start position:0% +we didn't approximate saying h-bar goes +to zero we did a more serious physical + + align:start position:0% +to zero we did a more serious physical + + + align:start position:0% +to zero we did a more serious physical +approximation and let's try to see what + + align:start position:0% +approximation and let's try to see what + + + align:start position:0% +approximation and let's try to see what +what we really did so I think the whole + + align:start position:0% +what we really did so I think the whole + + + align:start position:0% +what we really did so I think the whole +clue is enough in this top equation + + align:start position:0% +clue is enough in this top equation + + + align:start position:0% +clue is enough in this top equation +there you have the first term in the + + align:start position:0% +there you have the first term in the + + + align:start position:0% +there you have the first term in the +second term and our claim is that the + + align:start position:0% +second term and our claim is that the + + + align:start position:0% +second term and our claim is that the +second term is smaller than the first + + align:start position:0% +second term is smaller than the first + + + align:start position:0% +second term is smaller than the first +term with h-bar there so for example now + + align:start position:0% +term with h-bar there so for example now + + + align:start position:0% +term with h-bar there so for example now +of course in the solution the first term + + align:start position:0% +of course in the solution the first term + + + align:start position:0% +of course in the solution the first term +is identically zero and the second term + + align:start position:0% +is identically zero and the second term + + + align:start position:0% +is identically zero and the second term +the coefficient of H bar is identically + + align:start position:0% +the coefficient of H bar is identically + + + align:start position:0% +the coefficient of H bar is identically +zero but we can look at one of those for + + align:start position:0% +zero but we can look at one of those for + + + align:start position:0% +zero but we can look at one of those for +example and and say that + + align:start position:0% +example and and say that + + + align:start position:0% +example and and say that +so the validity of the approximation DT + + align:start position:0% +so the validity of the approximation DT + + + align:start position:0% +so the validity of the approximation DT +of the approximation it's pretty useful + + align:start position:0% +of the approximation it's pretty useful + + + align:start position:0% +of the approximation it's pretty useful +to do this so we say for example there + + align:start position:0% +to do this so we say for example there + + + align:start position:0% +to do this so we say for example there +that term H bar s zero double prime that + + align:start position:0% +that term H bar s zero double prime that + + + align:start position:0% +that term H bar s zero double prime that +enters into the order H bar part of the + + align:start position:0% +enters into the order H bar part of the + + + align:start position:0% +enters into the order H bar part of the +equation the absolute value of it must + + align:start position:0% +equation the absolute value of it must + + + align:start position:0% +equation the absolute value of it must +be much smaller than a typical term s 0 + + align:start position:0% +be much smaller than a typical term s 0 + + + align:start position:0% +be much smaller than a typical term s 0 +prime for example a zero prime squared + + align:start position:0% +prime for example a zero prime squared + + + align:start position:0% +prime for example a zero prime squared +in the first term so each term so + + align:start position:0% +in the first term so each term so + + + align:start position:0% +in the first term so each term so +basically I'm saying each term in the + + align:start position:0% +basically I'm saying each term in the + + + align:start position:0% +basically I'm saying each term in the +first bracket must be much larger + + align:start position:0% +first bracket must be much larger + + + align:start position:0% +first bracket must be much larger +each term in the second bracket and you + + align:start position:0% +each term in the second bracket and you + + + align:start position:0% +each term in the second bracket and you +could have picked any ones because + + align:start position:0% +could have picked any ones because + + + align:start position:0% +could have picked any ones because +they're all equal after all so let's see + + align:start position:0% +they're all equal after all so let's see + + + align:start position:0% +they're all equal after all so let's see +if that is the case so recall that s0 + + align:start position:0% +if that is the case so recall that s0 + + + align:start position:0% +if that is the case so recall that s0 +Prime from there is really P of X plus + + align:start position:0% +Prime from there is really P of X plus + + + align:start position:0% +Prime from there is really P of X plus +minus P of X so what do we have here H + + align:start position:0% +minus P of X so what do we have here H + + + align:start position:0% +minus P of X so what do we have here H +bar and s 0 double prime is DP DX must + + align:start position:0% +bar and s 0 double prime is DP DX must + + + align:start position:0% +bar and s 0 double prime is DP DX must +be much smaller than P of x squared now + + align:start position:0% +be much smaller than P of x squared now + + + align:start position:0% +be much smaller than P of x squared now +it's a matter of playing with these + + align:start position:0% +it's a matter of playing with these + + + align:start position:0% +it's a matter of playing with these +things a little bit until you find some + + align:start position:0% +things a little bit until you find some + + + align:start position:0% +things a little bit until you find some +way that inequality tells you a story + + align:start position:0% +way that inequality tells you a story + + + align:start position:0% +way that inequality tells you a story +and the way I'll do it is by saying that + + align:start position:0% +and the way I'll do it is by saying that + + + align:start position:0% +and the way I'll do it is by saying that +this is H bar 1 over P squared of X the + + align:start position:0% +this is H bar 1 over P squared of X the + + + align:start position:0% +this is H bar 1 over P squared of X the +P DX is much smaller than 1 and here + + align:start position:0% +P DX is much smaller than 1 and here + + + align:start position:0% +P DX is much smaller than 1 and here +I'll write this as H bar the know H bar + + align:start position:0% +I'll write this as H bar the know H bar + + + align:start position:0% +I'll write this as H bar the know H bar +DDX of H bar over P look what I did + + align:start position:0% +DDX of H bar over P look what I did + + + align:start position:0% +DDX of H bar over P look what I did +d DX of 1 over P is 1 over P Square DP + + align:start position:0% +d DX of 1 over P is 1 over P Square DP + + + align:start position:0% +d DX of 1 over P is 1 over P Square DP +DX and the H bar I put it in here we go + + align:start position:0% +DX and the H bar I put it in here we go + + + align:start position:0% +DX and the H bar I put it in here we go +what does this say this is the local de + + align:start position:0% +what does this say this is the local de + + + align:start position:0% +what does this say this is the local de +Broglie wavelength this is saying that + + align:start position:0% +Broglie wavelength this is saying that + + + align:start position:0% +Broglie wavelength this is saying that +DDX of the local de Broglie wavelength + + align:start position:0% +DDX of the local de Broglie wavelength + + + align:start position:0% +DDX of the local de Broglie wavelength +must be much smaller than 1 a nice + + align:start position:0% +must be much smaller than 1 a nice + + + align:start position:0% +must be much smaller than 1 a nice +result your local the broccoli + + align:start position:0% +result your local the broccoli + + + align:start position:0% +result your local the broccoli +wavelength must have a small derivative + + align:start position:0% +wavelength must have a small derivative + + + align:start position:0% +wavelength must have a small derivative +so this is the physics translation of + + align:start position:0% +so this is the physics translation of + + + align:start position:0% +so this is the physics translation of +the semi classical approximation H bar + + align:start position:0% +the semi classical approximation H bar + + + align:start position:0% +the semi classical approximation H bar +going to 0 as a mathematical device but + + align:start position:0% +going to 0 as a mathematical device but + + + align:start position:0% +going to 0 as a mathematical device but +this is physical this + + align:start position:0% +this is physical this + + + align:start position:0% +this is physical this +is telling you what should happen most + + align:start position:0% +is telling you what should happen most + + + align:start position:0% +is telling you what should happen most +of us look at that and say an easier way + + align:start position:0% +of us look at that and say an easier way + + + align:start position:0% +of us look at that and say an easier way +to understand that equation the lambda + + align:start position:0% +to understand that equation the lambda + + + align:start position:0% +to understand that equation the lambda +DX it has the right units lambda has + + align:start position:0% +DX it has the right units lambda has + + + align:start position:0% +DX it has the right units lambda has +units of length X has units of length so + + align:start position:0% +units of length X has units of length so + + + align:start position:0% +units of length X has units of length so +that derivative must have no units and + + align:start position:0% +that derivative must have no units and + + + align:start position:0% +that derivative must have no units and +if it's supposed to be small it should + + align:start position:0% +if it's supposed to be small it should + + + align:start position:0% +if it's supposed to be small it should +be small compared to one so this is a + + align:start position:0% +be small compared to one so this is a + + + align:start position:0% +be small compared to one so this is a +conventional inequality most of us would + + align:start position:0% +conventional inequality most of us would + + + align:start position:0% +conventional inequality most of us would +prefer baby to write it like this lambda + + align:start position:0% +prefer baby to write it like this lambda + + + align:start position:0% +prefer baby to write it like this lambda +D lambda DX is much smaller than lambda + + align:start position:0% +D lambda DX is much smaller than lambda + + + align:start position:0% +D lambda DX is much smaller than lambda +and I think this is a little clearer + + align:start position:0% +and I think this is a little clearer + + + align:start position:0% +and I think this is a little clearer +because this is how much the de Broglie + + align:start position:0% +because this is how much the de Broglie + + + align:start position:0% +because this is how much the de Broglie +wavelength changes over a distance equal + + align:start position:0% +wavelength changes over a distance equal + + + align:start position:0% +wavelength changes over a distance equal +to the de Broglie wavelength so you have + + align:start position:0% +to the de Broglie wavelength so you have + + + align:start position:0% +to the de Broglie wavelength so you have +at the broadly wavelength and then makes + + align:start position:0% +at the broadly wavelength and then makes + + + align:start position:0% +at the broadly wavelength and then makes +the Broglie wavelength how much is it + + align:start position:0% +the Broglie wavelength how much is it + + + align:start position:0% +the Broglie wavelength how much is it +change that must be small compared to + + align:start position:0% +change that must be small compared to + + + align:start position:0% +change that must be small compared to +the de Broglie wavelength so the change + + align:start position:0% +the de Broglie wavelength so the change + + + align:start position:0% +the de Broglie wavelength so the change +of the de Broglie wavelength after you + + align:start position:0% +of the de Broglie wavelength after you + + + align:start position:0% +of the de Broglie wavelength after you +move one the brown blue wavelength must + + align:start position:0% +move one the brown blue wavelength must + + + align:start position:0% +move one the brown blue wavelength must +be smaller than the de Broglie wave I + + align:start position:0% +be smaller than the de Broglie wave I + + + align:start position:0% +be smaller than the de Broglie wave I +don't know if you like it otherwise you + + align:start position:0% +don't know if you like it otherwise you + + + align:start position:0% +don't know if you like it otherwise you +can take this one I'll do another one + + align:start position:0% +can take this one I'll do another one + + + align:start position:0% +can take this one I'll do another one +another version of the inequalities and + + align:start position:0% +another version of the inequalities and + + + align:start position:0% +another version of the inequalities and +you can play with those inequalities + + align:start position:0% +you can play with those inequalities + + + align:start position:0% +you can play with those inequalities +it's kind of fun + + align:start position:0% +it's kind of fun + + + align:start position:0% +it's kind of fun +takes a while until you convince + + align:start position:0% +takes a while until you convince + + + align:start position:0% +takes a while until you convince +yourself that you're not missing + + align:start position:0% +yourself that you're not missing + + + align:start position:0% +yourself that you're not missing +anything think of P squared equal to M e + + align:start position:0% +anything think of P squared equal to M e + + + align:start position:0% +anything think of P squared equal to M e +minus V of X take a derivative v V X so + + align:start position:0% +minus V of X take a derivative v V X so + + + align:start position:0% +minus V of X take a derivative v V X so +I'll have PP prime this is 2 PP prime + + align:start position:0% +I'll have PP prime this is 2 PP prime + + + align:start position:0% +I'll have PP prime this is 2 PP prime +but with this 2 I'm gonna cancel it at + + align:start position:0% +but with this 2 I'm gonna cancel it at + + + align:start position:0% +but with this 2 I'm gonna cancel it at +some point of course we we're taking all + + align:start position:0% +some point of course we we're taking all + + + align:start position:0% +some point of course we we're taking all +kinds of factors of 2 and ignoring them + + align:start position:0% +kinds of factors of 2 and ignoring them + + + align:start position:0% +kinds of factors of 2 and ignoring them +remember that through the broad leeway + + align:start position:0% +remember that through the broad leeway + + + align:start position:0% +remember that through the broad leeway +from this H over P naught H bar over P + + align:start position:0% +from this H over P naught H bar over P + + + align:start position:0% +from this H over P naught H bar over P +so factors by the time you go + + align:start position:0% +so factors by the time you go + + + align:start position:0% +so factors by the time you go +- this inequalities - pies are done em + + align:start position:0% +- this inequalities - pies are done em + + + align:start position:0% +- this inequalities - pies are done em +we're differentiating with respect to X + + align:start position:0% +we're differentiating with respect to X + + + align:start position:0% +we're differentiating with respect to X +and taking absolute value so we write it + + align:start position:0% +and taking absolute value so we write it + + + align:start position:0% +and taking absolute value so we write it +like this or vvd X the x equals 1 over m + + align:start position:0% +like this or vvd X the x equals 1 over m + + + align:start position:0% +like this or vvd X the x equals 1 over m +PP prime that is so far exact let me + + align:start position:0% +PP prime that is so far exact let me + + + align:start position:0% +PP prime that is so far exact let me +multiply by a lambda so I'll have a + + align:start position:0% +multiply by a lambda so I'll have a + + + align:start position:0% +multiply by a lambda so I'll have a +lambda + + align:start position:0% + + + + align:start position:0% + +and lambda V V DX is equal to we are + + align:start position:0% +and lambda V V DX is equal to we are + + + align:start position:0% +and lambda V V DX is equal to we are +lambda okay + + align:start position:0% +lambda okay + + + align:start position:0% +lambda okay +lambda is h-bar over P so I can cancel + + align:start position:0% +lambda is h-bar over P so I can cancel + + + align:start position:0% +lambda is h-bar over P so I can cancel +one of these piece and get h-bar over m + + align:start position:0% +one of these piece and get h-bar over m + + + align:start position:0% +one of these piece and get h-bar over m +P prime okay now look at this equation + + align:start position:0% +P prime okay now look at this equation + + + align:start position:0% +P prime okay now look at this equation +sorry we'll play with it's a little like + + align:start position:0% +sorry we'll play with it's a little like + + + align:start position:0% +sorry we'll play with it's a little like +trial and error you're trying to move + + align:start position:0% +trial and error you're trying to move + + + align:start position:0% +trial and error you're trying to move +around your inequality so here we have + + align:start position:0% +around your inequality so here we have + + + align:start position:0% +around your inequality so here we have +something H bar DP DX is much less than + + align:start position:0% +something H bar DP DX is much less than + + + align:start position:0% +something H bar DP DX is much less than +that so this term is because of this + + align:start position:0% +that so this term is because of this + + + align:start position:0% +that so this term is because of this +inequality is much smaller than P + + align:start position:0% +inequality is much smaller than P + + + align:start position:0% +inequality is much smaller than P +squared over m and now we have something + + align:start position:0% +squared over m and now we have something + + + align:start position:0% +squared over m and now we have something +nice I'll write it here lambda of X DV + + align:start position:0% +nice I'll write it here lambda of X DV + + + align:start position:0% +nice I'll write it here lambda of X DV +DX is much smaller than P squared over + + align:start position:0% +DX is much smaller than P squared over + + + align:start position:0% +DX is much smaller than P squared over +2m that's another nice one I think this + + align:start position:0% +2m that's another nice one I think this + + + align:start position:0% +2m that's another nice one I think this +one is + + align:start position:0% + + + + align:start position:0% + +and this says that the potential must be + + align:start position:0% +and this says that the potential must be + + + align:start position:0% +and this says that the potential must be +slowly varying for this to be true + + align:start position:0% +slowly varying for this to be true + + + align:start position:0% +slowly varying for this to be true +because the change in the potential over + + align:start position:0% +because the change in the potential over + + + align:start position:0% +because the change in the potential over +at the broccoli wavelength DV DX x + + align:start position:0% +at the broccoli wavelength DV DX x + + + align:start position:0% +at the broccoli wavelength DV DX x +lambda FX is an estimate for the change + + align:start position:0% +lambda FX is an estimate for the change + + + align:start position:0% +lambda FX is an estimate for the change +of the potential over the de Broglie + + align:start position:0% +of the potential over the de Broglie + + + align:start position:0% +of the potential over the de Broglie +wavelength is much smaller than the + + align:start position:0% +wavelength is much smaller than the + + + align:start position:0% +wavelength is much smaller than the +kinetic energy of the particle so that's + + align:start position:0% +kinetic energy of the particle so that's + + + align:start position:0% +kinetic energy of the particle so that's +again another thing that makes sense + + align:start position:0% +again another thing that makes sense + + + align:start position:0% +again another thing that makes sense +it's kind of nice so this is the wave at + + align:start position:0% +it's kind of nice so this is the wave at + + + align:start position:0% +it's kind of nice so this is the wave at +the end of the day this h-bar going to + + align:start position:0% +the end of the day this h-bar going to + + + align:start position:0% +the end of the day this h-bar going to +zero approximation has become a physical + + align:start position:0% +zero approximation has become a physical + + + align:start position:0% +zero approximation has become a physical +statement it is a statement of + + align:start position:0% +statement it is a statement of + + + align:start position:0% +statement it is a statement of +quantities varying slowly because after + + align:start position:0% +quantities varying slowly because after + + + align:start position:0% +quantities varying slowly because after +all that's what motivated the expansion + + align:start position:0% +all that's what motivated the expansion + + + align:start position:0% +all that's what motivated the expansion +from the beginning so let's see if we + + align:start position:0% +from the beginning so let's see if we + + + align:start position:0% +from the beginning so let's see if we +ever get in trouble with this so we're + + align:start position:0% +ever get in trouble with this so we're + + + align:start position:0% +ever get in trouble with this so we're +trying to solve physical problems of + + align:start position:0% +trying to solve physical problems of + + + align:start position:0% +trying to solve physical problems of +particles in potentials and most of the + + align:start position:0% +particles in potentials and most of the + + + align:start position:0% +particles in potentials and most of the +times were interested in bound States or + + align:start position:0% +times were interested in bound States or + + + align:start position:0% +times were interested in bound States or +energy eigenstates at least the simple + + align:start position:0% +energy eigenstates at least the simple + + + align:start position:0% +energy eigenstates at least the simple +energy eigenstates are bound States so + + align:start position:0% +energy eigenstates are bound States so + + + align:start position:0% +energy eigenstates are bound States so +here is a situation we have a sketch of + + align:start position:0% +here is a situation we have a sketch of + + + align:start position:0% +here is a situation we have a sketch of +a situation we have a V of X this is X + + align:start position:0% +a situation we have a V of X this is X + + + align:start position:0% +a situation we have a V of X this is X +this is a V of X and some energy E and + + align:start position:0% + + + + align:start position:0% + +let's assume we're looking close enough + + align:start position:0% +let's assume we're looking close enough + + + align:start position:0% +let's assume we're looking close enough +to the point X equal a so that the V of + + align:start position:0% +to the point X equal a so that the V of + + + align:start position:0% +to the point X equal a so that the V of +X however it curves at that point is + + align:start position:0% +X however it curves at that point is + + + align:start position:0% +X however it curves at that point is +roughly straight that's a reasonable + + align:start position:0% +roughly straight that's a reasonable + + + align:start position:0% +roughly straight that's a reasonable +thing to do + + align:start position:0% +thing to do + + + align:start position:0% +thing to do +so we'll model V of X + + align:start position:0% +so we'll model V of X + + + align:start position:0% +so we'll model V of X +- e V of X - C as being linear near x + + align:start position:0% +- e V of X - C as being linear near x + + + align:start position:0% +- e V of X - C as being linear near x +equals a so is G times X - a / G some + + align:start position:0% +equals a so is G times X - a / G some + + + align:start position:0% +equals a so is G times X - a / G some +positive constant which is the slope at + + align:start position:0% +positive constant which is the slope at + + + align:start position:0% +positive constant which is the slope at +this point so look at X less than a at + + align:start position:0% +this point so look at X less than a at + + + align:start position:0% +this point so look at X less than a at +this point you are in the loud region + + align:start position:0% +this point you are in the loud region + + + align:start position:0% +this point you are in the loud region +you're in the region to the left of the + + align:start position:0% +you're in the region to the left of the + + + align:start position:0% +you're in the region to the left of the +point a for your energy is bigger than + + align:start position:0% +point a for your energy is bigger than + + + align:start position:0% +point a for your energy is bigger than +the potential and that's perfectly + + align:start position:0% +the potential and that's perfectly + + + align:start position:0% +the potential and that's perfectly +allowed so so here e minus V of X which + + align:start position:0% +allowed so so here e minus V of X which + + + align:start position:0% +allowed so so here e minus V of X which +is the negative of that would be G a - X + + align:start position:0% +is the negative of that would be G a - X + + + align:start position:0% +is the negative of that would be G a - X +and P is square root of 2m e minus V of + + align:start position:0% +and P is square root of 2m e minus V of + + + align:start position:0% +and P is square root of 2m e minus V of +X so G a minus X that's P of X so that's + + align:start position:0% +X so G a minus X that's P of X so that's + + + align:start position:0% +X so G a minus X that's P of X so that's +your position dependent momentum it's + + align:start position:0% +your position dependent momentum it's + + + align:start position:0% +your position dependent momentum it's +going to go to 0 at that point and + + align:start position:0% +going to go to 0 at that point and + + + align:start position:0% +going to go to 0 at that point and +lambda which is H bar over P is H bar + + align:start position:0% +lambda which is H bar over P is H bar + + + align:start position:0% +lambda which is H bar over P is H bar +over square root of 2mg + + align:start position:0% +over square root of 2mg + + + align:start position:0% +over square root of 2mg +1 over square root of a minus X so take + + align:start position:0% +1 over square root of a minus X so take + + + align:start position:0% +1 over square root of a minus X so take +the derivative be lambda DX take the + + align:start position:0% +the derivative be lambda DX take the + + + align:start position:0% +the derivative be lambda DX take the +absolute value of it that's H bar over + + align:start position:0% +absolute value of it that's H bar over + + + align:start position:0% +absolute value of it that's H bar over +square root of 2mg + + align:start position:0% +square root of 2mg + + + align:start position:0% +square root of 2mg +times 1/2 1 over a minus x to the + + align:start position:0% +times 1/2 1 over a minus x to the + + + align:start position:0% +times 1/2 1 over a minus x to the +three-halves we're differentiating with + + align:start position:0% +three-halves we're differentiating with + + + align:start position:0% +three-halves we're differentiating with +respect to X and now you see the trouble + + align:start position:0% +respect to X and now you see the trouble + + + align:start position:0% +respect to X and now you see the trouble +if you had not seen it before the + + align:start position:0% +if you had not seen it before the + + + align:start position:0% +if you had not seen it before the +validity of the semi-classical + + align:start position:0% +validity of the semi-classical + + + align:start position:0% +validity of the semi-classical +approximation is taken requires the + + align:start position:0% +approximation is taken requires the + + + align:start position:0% +approximation is taken requires the +lambda DX to be much smaller than 1 and + + align:start position:0% +lambda DX to be much smaller than 1 and + + + align:start position:0% +lambda DX to be much smaller than 1 and +as you approach x equals to a these + + align:start position:0% +as you approach x equals to a these + + + align:start position:0% +as you approach x equals to a these +grows within without bound + + align:start position:0% +grows within without bound + + + align:start position:0% +grows within without bound +it just becomes bigger and bigger you + + align:start position:0% +it just becomes bigger and bigger you + + + align:start position:0% +it just becomes bigger and bigger you +can choose G to be large and you can + + align:start position:0% +can choose G to be large and you can + + + align:start position:0% +can choose G to be large and you can +choose m to be large but still you get + + align:start position:0% +choose m to be large but still you get + + + align:start position:0% +choose m to be large but still you get +closer and closer you eventually fail + + align:start position:0% +closer and closer you eventually fail + + + align:start position:0% +closer and closer you eventually fail +this thing goes to infinity as X goes to + + align:start position:0% +this thing goes to infinity as X goes to + + + align:start position:0% +this thing goes to infinity as X goes to +a and grows without limit and the + + align:start position:0% +a and grows without limit and the + + + align:start position:0% +a and grows without limit and the +semi-classical approximation crashes you + + align:start position:0% +semi-classical approximation crashes you + + + align:start position:0% +semi-classical approximation crashes you +know I would imagine that many people + + align:start position:0% +know I would imagine that many people + + + align:start position:0% +know I would imagine that many people +got this far with this and my classical + + align:start position:0% +got this far with this and my classical + + + align:start position:0% +got this far with this and my classical +approximation of writing this and doing + + align:start position:0% +approximation of writing this and doing + + + align:start position:0% +approximation of writing this and doing +that but this is a tremendous obstacle + + align:start position:0% +that but this is a tremendous obstacle + + + align:start position:0% +that but this is a tremendous obstacle +why is it an obstacle why can't we just + + align:start position:0% +why is it an obstacle why can't we just + + + align:start position:0% +why is it an obstacle why can't we just +forget about that region because most of + + align:start position:0% +forget about that region because most of + + + align:start position:0% +forget about that region because most of +the times you do dealing with bound + + align:start position:0% +the times you do dealing with bound + + + align:start position:0% +the times you do dealing with bound +states so you will have a very slowly + + align:start position:0% +states so you will have a very slowly + + + align:start position:0% +states so you will have a very slowly +varying potential here but if you want + + align:start position:0% +varying potential here but if you want + + + align:start position:0% +varying potential here but if you want +to find bound States you need the fact + + align:start position:0% +to find bound States you need the fact + + + align:start position:0% +to find bound States you need the fact +that there's a forbidden region for the + + align:start position:0% +that there's a forbidden region for the + + + align:start position:0% +that there's a forbidden region for the +wave function destroys itself so + + align:start position:0% +wave function destroys itself so + + + align:start position:0% +wave function destroys itself so +whatever you can solve for the wave + + align:start position:0% +whatever you can solve for the wave + + + align:start position:0% +whatever you can solve for the wave +function is slowly varying here it's not + + align:start position:0% +function is slowly varying here it's not + + + align:start position:0% +function is slowly varying here it's not +enough because you need to know how it + + align:start position:0% +enough because you need to know how it + + + align:start position:0% +enough because you need to know how it +behaves and therefore you need to face + + align:start position:0% +behaves and therefore you need to face + + + align:start position:0% +behaves and therefore you need to face +this corners where the semi-classical + + align:start position:0% +this corners where the semi-classical + + + align:start position:0% +this corners where the semi-classical +approximation fails our problem here + + align:start position:0% +approximation fails our problem here + + + align:start position:0% +approximation fails our problem here +is that we know how to write a solution + + align:start position:0% +is that we know how to write a solution + + + align:start position:0% +is that we know how to write a solution +here we probably know how to write the + + align:start position:0% +here we probably know how to write the + + + align:start position:0% +here we probably know how to write the +solution here those are this ones but we + + align:start position:0% +solution here those are this ones but we + + + align:start position:0% +solution here those are this ones but we +have no idea how to write them here so + + align:start position:0% +have no idea how to write them here so + + + align:start position:0% +have no idea how to write them here so +we cannot connect the two solutions it's + + align:start position:0% +we cannot connect the two solutions it's + + + align:start position:0% +we cannot connect the two solutions it's +a serious difficulty it's so people work + + align:start position:0% +a serious difficulty it's so people work + + + align:start position:0% +a serious difficulty it's so people work +hard on that and I think that is the + + align:start position:0% +hard on that and I think that is the + + + align:start position:0% +hard on that and I think that is the +breakthrough of the construction of this + + align:start position:0% +breakthrough of the construction of this + + + align:start position:0% +breakthrough of the construction of this +wkb people what they did is they solve + + align:start position:0% +wkb people what they did is they solve + + + align:start position:0% +wkb people what they did is they solve +the equation exactly in this region + + align:start position:0% +the equation exactly in this region + + + align:start position:0% +the equation exactly in this region +assuming a linear potential they solve + + align:start position:0% +assuming a linear potential they solve + + + align:start position:0% +assuming a linear potential they solve +it exactly and then those functions the + + align:start position:0% +it exactly and then those functions the + + + align:start position:0% +it exactly and then those functions the +airy functions show up and you know how + + align:start position:0% +airy functions show up and you know how + + + align:start position:0% +airy functions show up and you know how +the airy functions behave so they solve + + align:start position:0% +the airy functions behave so they solve + + + align:start position:0% +the airy functions behave so they solve +it here they related it to the solution + + align:start position:0% +it here they related it to the solution + + + align:start position:0% +it here they related it to the solution +to the right related them to a solution + + align:start position:0% +to the right related them to a solution + + + align:start position:0% +to the right related them to a solution +on the left and in that way even though + + align:start position:0% +on the left and in that way even though + + + align:start position:0% +on the left and in that way even though +we don't have to write the solution in + + align:start position:0% +we don't have to write the solution in + + + align:start position:0% +we don't have to write the solution in +this region we know how a solution on + + align:start position:0% +this region we know how a solution on + + + align:start position:0% +this region we know how a solution on +the middle connects to a solution on the + + align:start position:0% +the middle connects to a solution on the + + + align:start position:0% +the middle connects to a solution on the +right this is the subject of the + + align:start position:0% +right this is the subject of the + + + align:start position:0% +right this is the subject of the +connection formulas in wkb we will + + align:start position:0% +connection formulas in wkb we will + + + align:start position:0% +connection formulas in wkb we will +discuss that next time we will go + + align:start position:0% +discuss that next time we will go + + + align:start position:0% +discuss that next time we will go +through some of that analysis because + + align:start position:0% +through some of that analysis because + + + align:start position:0% +through some of that analysis because +it's interesting and fairly non-trivial + + align:start position:0% +it's interesting and fairly non-trivial + + + align:start position:0% +it's interesting and fairly non-trivial +but I will mention one of the connection + + align:start position:0% +but I will mention one of the connection + + + align:start position:0% +but I will mention one of the connection +for me lesson use it that's the rest of + + align:start position:0% +for me lesson use it that's the rest of + + + align:start position:0% +for me lesson use it that's the rest of +what we're gonna do today \ No newline at end of file diff --git a/ek8uUMmoziU.txt b/ek8uUMmoziU.txt new file mode 100644 index 0000000000000000000000000000000000000000..41d2ae037be30dc142987e5c22b331190be0350a --- /dev/null +++ b/ek8uUMmoziU.txt @@ -0,0 +1,51 @@ +3-1-4-1-5-9 This is pi, followed by + +2-6-5-3-5-8-9 circumference over di-ameter + +7-9 then 3-2-3, OMG! Can’t you see? + +8-4-6-2-6-4-3 and now we’re on a spree! + +38 and 32 Now we’re blue! Oh who knew? + +7950 and then a 2 + +88 and 41 So much fun! Now we run! + +9-7-1-6-9-3-9-9, 3-7-51 + +Half way done! + +0-5-8 Now don’t be late! + +2-0-9 Where’s the wine? + +7-4 It’s on the floor! + +Then 9-4-4-5-9. + +2-3-0 we gotta go! + +7-8 we can’t wait! + +1-6-4-0-6-2-8 We’re almost near the end + +keep going! + +62 we’re getting through! + +0-8-9, 9 on time! + +8-6-2-8-0-3-4 There’s only a few more! + +8-2, then 5-3 + +42, 11, 7, 0 and 67 + +We’re done! + +Was that fun? + +Learning random digits so that + +you can brag to your friends! \ No newline at end of file diff --git a/f93PZ9ZyvDk.txt b/f93PZ9ZyvDk.txt new file mode 100644 index 0000000000000000000000000000000000000000..9ed68de303d3abdaf882cbf4cde3233792d2ecbf --- /dev/null +++ b/f93PZ9ZyvDk.txt @@ -0,0 +1,5347 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hi our lesson today involves a rather + + align:start position:0% +hi our lesson today involves a rather + + + align:start position:0% +hi our lesson today involves a rather +subtle difference between a curve and a + + align:start position:0% +subtle difference between a curve and a + + + align:start position:0% +subtle difference between a curve and a +coordinate system in other words given a + + align:start position:0% +coordinate system in other words given a + + + align:start position:0% +coordinate system in other words given a +curve that curve has a certain shape has + + align:start position:0% +curve that curve has a certain shape has + + + align:start position:0% +curve that curve has a certain shape has +a certain position independently of + + align:start position:0% +a certain position independently of + + + align:start position:0% +a certain position independently of +where our coordinate axes are if we're + + align:start position:0% +where our coordinate axes are if we're + + + align:start position:0% +where our coordinate axes are if we're +using cartisian coordinates or whether + + align:start position:0% +using cartisian coordinates or whether + + + align:start position:0% +using cartisian coordinates or whether +we're using other coordinate systems or + + align:start position:0% +we're using other coordinate systems or + + + align:start position:0% +we're using other coordinate systems or +what have you + + align:start position:0% +what have you + + + align:start position:0% +what have you +but the equation of the curve may very + + align:start position:0% +but the equation of the curve may very + + + align:start position:0% +but the equation of the curve may very +well depend on what coordinate system + + align:start position:0% +well depend on what coordinate system + + + align:start position:0% +well depend on what coordinate system +we're using you see the thing that we + + align:start position:0% +we're using you see the thing that we + + + align:start position:0% +we're using you see the thing that we +would like to do in this particular + + align:start position:0% +would like to do in this particular + + + align:start position:0% +would like to do in this particular +lecture is to hit a very important + + align:start position:0% +lecture is to hit a very important + + + align:start position:0% +lecture is to hit a very important +highlight that comes up well you can + + align:start position:0% +highlight that comes up well you can + + + align:start position:0% +highlight that comes up well you can +motivate it from a purely mathematical + + align:start position:0% +motivate it from a purely mathematical + + + align:start position:0% +motivate it from a purely mathematical +point of view but physically there's an + + align:start position:0% +point of view but physically there's an + + + align:start position:0% +point of view but physically there's an +even more natural interpretation and + + align:start position:0% +even more natural interpretation and + + + align:start position:0% +even more natural interpretation and +basically what the thing hinges on is + + align:start position:0% +basically what the thing hinges on is + + + align:start position:0% +basically what the thing hinges on is +this if you given a curve in space we'll + + align:start position:0% +this if you given a curve in space we'll + + + align:start position:0% +this if you given a curve in space we'll +start with a curve in the plane but it + + align:start position:0% +start with a curve in the plane but it + + + align:start position:0% +start with a curve in the plane but it +applies to Curves in space as well and + + align:start position:0% +applies to Curves in space as well and + + + align:start position:0% +applies to Curves in space as well and +that is given that curve in the + + align:start position:0% +that is given that curve in the + + + align:start position:0% +that is given that curve in the +plane does that curve have certain + + align:start position:0% +plane does that curve have certain + + + align:start position:0% +plane does that curve have certain +properties regardless of whether you + + align:start position:0% +properties regardless of whether you + + + align:start position:0% +properties regardless of whether you +know what your coordinate system is or + + align:start position:0% +know what your coordinate system is or + + + align:start position:0% +know what your coordinate system is or +not or in still other words can you + + align:start position:0% +not or in still other words can you + + + align:start position:0% +not or in still other words can you +measure the shape of the curve can you + + align:start position:0% +measure the shape of the curve can you + + + align:start position:0% +measure the shape of the curve can you +measure the speed along the curve as a + + align:start position:0% +measure the speed along the curve as a + + + align:start position:0% +measure the speed along the curve as a +particle traverses it if you had never + + align:start position:0% +particle traverses it if you had never + + + align:start position:0% +particle traverses it if you had never +heard of the X and Y coordinate system + + align:start position:0% +heard of the X and Y coordinate system + + + align:start position:0% +heard of the X and Y coordinate system +and what this leads to is a new system + + align:start position:0% +and what this leads to is a new system + + + align:start position:0% +and what this leads to is a new system +of vectors by which we study otion in + + align:start position:0% +of vectors by which we study otion in + + + align:start position:0% +of vectors by which we study otion in +space called tangential and normal + + align:start position:0% +space called tangential and normal + + + align:start position:0% +space called tangential and normal +vectors when we're dealing in the plane + + align:start position:0% +vectors when we're dealing in the plane + + + align:start position:0% +vectors when we're dealing in the plane +and there's a third member called the + + align:start position:0% +and there's a third member called the + + + align:start position:0% +and there's a third member called the +binormal vector which we'll talk about + + align:start position:0% +binormal vector which we'll talk about + + + align:start position:0% +binormal vector which we'll talk about +later when we deal in three-dimensional + + align:start position:0% +later when we deal in three-dimensional + + + align:start position:0% +later when we deal in three-dimensional +space any rate just for brevity I call + + align:start position:0% +space any rate just for brevity I call + + + align:start position:0% +space any rate just for brevity I call +this lecture tangential and normal + + align:start position:0% +this lecture tangential and normal + + + align:start position:0% +this lecture tangential and normal +vectors and the idea is something like + + align:start position:0% +vectors and the idea is something like + + + align:start position:0% +vectors and the idea is something like +this we're given a curve + + align:start position:0% +this we're given a curve + + + align:start position:0% +this we're given a curve +C now given this particular curve C it + + align:start position:0% +C now given this particular curve C it + + + align:start position:0% +C now given this particular curve C it +happens that we have a cartisian + + align:start position:0% +happens that we have a cartisian + + + align:start position:0% +happens that we have a cartisian +coordinate system here and it also + + align:start position:0% +coordinate system here and it also + + + align:start position:0% +coordinate system here and it also +happens that we prefer at least as we've + + align:start position:0% +happens that we prefer at least as we've + + + align:start position:0% +happens that we prefer at least as we've +done things in the past we write + + align:start position:0% +done things in the past we write + + + align:start position:0% +done things in the past we write +everything in terms of I and J + + align:start position:0% +everything in terms of I and J + + + align:start position:0% +everything in terms of I and J +components notice that if a person were + + align:start position:0% +components notice that if a person were + + + align:start position:0% +components notice that if a person were +restricted to his Universe being the + + align:start position:0% +restricted to his Universe being the + + + align:start position:0% +restricted to his Universe being the +curve c i and J have no basic meaning to + + align:start position:0% +curve c i and J have no basic meaning to + + + align:start position:0% +curve c i and J have no basic meaning to +him what does have a basic meaning to + + align:start position:0% +him what does have a basic meaning to + + + align:start position:0% +him what does have a basic meaning to +him as he's moving along this curve I + + align:start position:0% +him as he's moving along this curve I + + + align:start position:0% +him as he's moving along this curve I +would imagine would be what what is his + + align:start position:0% +would imagine would be what what is his + + + align:start position:0% +would imagine would be what what is his +his motion tangential to the curve in + + align:start position:0% +his motion tangential to the curve in + + + align:start position:0% +his motion tangential to the curve in +other words if you want to look at this + + align:start position:0% +other words if you want to look at this + + + align:start position:0% +other words if you want to look at this +from a calculus point of view if this is + + align:start position:0% +from a calculus point of view if this is + + + align:start position:0% +from a calculus point of view if this is +a smooth curve in a sufficiently small + + align:start position:0% +a smooth curve in a sufficiently small + + + align:start position:0% +a smooth curve in a sufficiently small +neighborhood of the this point you + + align:start position:0% +neighborhood of the this point you + + + align:start position:0% +neighborhood of the this point you +cannot distinguish between the curve and + + align:start position:0% +cannot distinguish between the curve and + + + align:start position:0% +cannot distinguish between the curve and +the tangent line and consequently one + + align:start position:0% +the tangent line and consequently one + + + align:start position:0% +the tangent line and consequently one +could interpret that at a given instant + + align:start position:0% +could interpret that at a given instant + + + align:start position:0% +could interpret that at a given instant +the motion was always along the straight + + align:start position:0% +the motion was always along the straight + + + align:start position:0% +the motion was always along the straight +line tangential to the curve what this + + align:start position:0% +line tangential to the curve what this + + + align:start position:0% +line tangential to the curve what this +leads to is the notion of inventing what + + align:start position:0% +leads to is the notion of inventing what + + + align:start position:0% +leads to is the notion of inventing what +we call a unit tangent Vector which I'll + + align:start position:0% +we call a unit tangent Vector which I'll + + + align:start position:0% +we call a unit tangent Vector which I'll +call + + align:start position:0% +call + + + align:start position:0% +call +T right and what is that tangent Vector + + align:start position:0% +T right and what is that tangent Vector + + + align:start position:0% +T right and what is that tangent Vector +it's not a constant mind you it shifts + + align:start position:0% +it's not a constant mind you it shifts + + + align:start position:0% +it's not a constant mind you it shifts +with position as you move along the + + align:start position:0% +with position as you move along the + + + align:start position:0% +with position as you move along the +curve what is constant is its magnitude + + align:start position:0% +curve what is constant is its magnitude + + + align:start position:0% +curve what is constant is its magnitude +has constant magnitude one I guess what + + align:start position:0% +has constant magnitude one I guess what + + + align:start position:0% +has constant magnitude one I guess what +I'm trying to say in sort of a + + align:start position:0% +I'm trying to say in sort of a + + + align:start position:0% +I'm trying to say in sort of a +surrealistic or + + align:start position:0% +surrealistic or + + + align:start position:0% +surrealistic or +metamathematical way is that t plays to + + align:start position:0% +metamathematical way is that t plays to + + + align:start position:0% +metamathematical way is that t plays to +a person who's living on the curve C the + + align:start position:0% +a person who's living on the curve C the + + + align:start position:0% +a person who's living on the curve C the +same role that I plays to a person + + align:start position:0% +same role that I plays to a person + + + align:start position:0% +same role that I plays to a person +living in our ordinary space that + + align:start position:0% +living in our ordinary space that + + + align:start position:0% +living in our ordinary space that +somehow or other he sees t as a constant + + align:start position:0% +somehow or other he sees t as a constant + + + align:start position:0% +somehow or other he sees t as a constant +Vector as he moves along the curve if he + + align:start position:0% +Vector as he moves along the curve if he + + + align:start position:0% +Vector as he moves along the curve if he +visualizes the curve as being a straight + + align:start position:0% +visualizes the curve as being a straight + + + align:start position:0% +visualizes the curve as being a straight +line he always sees it tangential to his + + align:start position:0% +line he always sees it tangential to his + + + align:start position:0% +line he always sees it tangential to his +motion now in the same way that J was a + + align:start position:0% +motion now in the same way that J was a + + + align:start position:0% +motion now in the same way that J was a +90° clockwise uh positive rotation of I + + align:start position:0% +90° clockwise uh positive rotation of I + + + align:start position:0% +90° clockwise uh positive rotation of I +one would like to mimic the I and J + + align:start position:0% +one would like to mimic the I and J + + + align:start position:0% +one would like to mimic the I and J +cartisian coordinate system by inventing + + align:start position:0% +cartisian coordinate system by inventing + + + align:start position:0% +cartisian coordinate system by inventing +another unit Vector which is again what + + align:start position:0% +another unit Vector which is again what + + + align:start position:0% +another unit Vector which is again what +a positive 90° rotation of + + align:start position:0% +a positive 90° rotation of + + + align:start position:0% +a positive 90° rotation of +T and we'll call that Vector + + align:start position:0% +T and we'll call that Vector + + + align:start position:0% +T and we'll call that Vector +n so that now we have a new system of + + align:start position:0% +n so that now we have a new system of + + + align:start position:0% +n so that now we have a new system of +coordinates t and n new system of + + align:start position:0% +coordinates t and n new system of + + + align:start position:0% +coordinates t and n new system of +variables or vectors whereby we can now + + align:start position:0% +variables or vectors whereby we can now + + + align:start position:0% +variables or vectors whereby we can now +study motional along a curve in a very + + align:start position:0% +study motional along a curve in a very + + + align:start position:0% +study motional along a curve in a very +natural way in other words we talk about + + align:start position:0% +natural way in other words we talk about + + + align:start position:0% +natural way in other words we talk about +the unit tangent Direction and the unit + + align:start position:0% +the unit tangent Direction and the unit + + + align:start position:0% +the unit tangent Direction and the unit +normal Direction all right and we have + + align:start position:0% +normal Direction all right and we have + + + align:start position:0% +normal Direction all right and we have +this thing now + + align:start position:0% + + + + align:start position:0% + +established what we would like to do is + + align:start position:0% +established what we would like to do is + + + align:start position:0% +established what we would like to do is +to see what happens in our study of + + align:start position:0% +to see what happens in our study of + + + align:start position:0% +to see what happens in our study of +kinematics Motion in the plane Motion in + + align:start position:0% +kinematics Motion in the plane Motion in + + + align:start position:0% +kinematics Motion in the plane Motion in +space if we work in terms of tangential + + align:start position:0% +space if we work in terms of tangential + + + align:start position:0% +space if we work in terms of tangential +and normal components now rather than in + + align:start position:0% +and normal components now rather than in + + + align:start position:0% +and normal components now rather than in +terms of I and J components the first + + align:start position:0% +terms of I and J components the first + + + align:start position:0% +terms of I and J components the first +thing that we' probably like to do is + + align:start position:0% +thing that we' probably like to do is + + + align:start position:0% +thing that we' probably like to do is +figure out how in the world do you + + align:start position:0% +figure out how in the world do you + + + align:start position:0% +figure out how in the world do you +compute T well for example let's take a + + align:start position:0% +compute T well for example let's take a + + + align:start position:0% +compute T well for example let's take a +particular application let's take the + + align:start position:0% +particular application let's take the + + + align:start position:0% +particular application let's take the +example that we were dealing with last + + align:start position:0% +example that we were dealing with last + + + align:start position:0% +example that we were dealing with last +time where we had the radius Vector R in + + align:start position:0% +time where we had the radius Vector R in + + + align:start position:0% +time where we had the radius Vector R in +other words the scal of function T where + + align:start position:0% +other words the scal of function T where + + + align:start position:0% +other words the scal of function T where +T denoted time and we were dealing with + + align:start position:0% +T denoted time and we were dealing with + + + align:start position:0% +T denoted time and we were dealing with +what Motion in space where the radius + + align:start position:0% +what Motion in space where the radius + + + align:start position:0% +what Motion in space where the radius +Vector R was a function of T and + + align:start position:0% +Vector R was a function of T and + + + align:start position:0% +Vector R was a function of T and +remember what we showed last time we + + align:start position:0% +remember what we showed last time we + + + align:start position:0% +remember what we showed last time we +showed that the rdt the velocity Vector + + align:start position:0% +showed that the rdt the velocity Vector + + + align:start position:0% +showed that the rdt the velocity Vector +has + + align:start position:0% +has + + + align:start position:0% +has +it's what its direction is always + + align:start position:0% +it's what its direction is always + + + align:start position:0% +it's what its direction is always +tangent to the curve we proved that last + + align:start position:0% +tangent to the curve we proved that last + + + align:start position:0% +tangent to the curve we proved that last +time well look at as long as the rdt is + + align:start position:0% +time well look at as long as the rdt is + + + align:start position:0% +time well look at as long as the rdt is +always tangent to the curve what + + align:start position:0% +always tangent to the curve what + + + align:start position:0% +always tangent to the curve what +prevents it from being a unit tangent + + align:start position:0% +prevents it from being a unit tangent + + + align:start position:0% +prevents it from being a unit tangent +Vector well nothing prevents it from + + align:start position:0% +Vector well nothing prevents it from + + + align:start position:0% +Vector well nothing prevents it from +being a tangent Vector because it's + + align:start position:0% +being a tangent Vector because it's + + + align:start position:0% +being a tangent Vector because it's +already tangent to the curve all that + + align:start position:0% +already tangent to the curve all that + + + align:start position:0% +already tangent to the curve all that +could go wrong is that the magnitude of + + align:start position:0% +could go wrong is that the magnitude of + + + align:start position:0% +could go wrong is that the magnitude of +the rdt is not one well look at that's + + align:start position:0% +the rdt is not one well look at that's + + + align:start position:0% +the rdt is not one well look at that's +again a very simple point to fix up + + align:start position:0% +again a very simple point to fix up + + + align:start position:0% +again a very simple point to fix up +namely if the magnitude of the rdt is + + align:start position:0% +namely if the magnitude of the rdt is + + + align:start position:0% +namely if the magnitude of the rdt is +not one suppose we divide divide that + + align:start position:0% +not one suppose we divide divide that + + + align:start position:0% +not one suppose we divide divide that +vector by its magnitude we have already + + align:start position:0% +vector by its magnitude we have already + + + align:start position:0% +vector by its magnitude we have already +seen that given any nonzero Vector if + + align:start position:0% +seen that given any nonzero Vector if + + + align:start position:0% +seen that given any nonzero Vector if +you divide that vector by its magnitude + + align:start position:0% +you divide that vector by its magnitude + + + align:start position:0% +you divide that vector by its magnitude +you get the unit Vector in the same + + align:start position:0% +you get the unit Vector in the same + + + align:start position:0% +you get the unit Vector in the same +direction as the vector that you started + + align:start position:0% +direction as the vector that you started + + + align:start position:0% +direction as the vector that you started +with in other words if I take the vector + + align:start position:0% +with in other words if I take the vector + + + align:start position:0% +with in other words if I take the vector +drdt which is already tangential to the + + align:start position:0% +drdt which is already tangential to the + + + align:start position:0% +drdt which is already tangential to the +curve at the given point and I divide + + align:start position:0% +curve at the given point and I divide + + + align:start position:0% +curve at the given point and I divide +that by the magnitude of the rdt then I + + align:start position:0% +that by the magnitude of the rdt then I + + + align:start position:0% +that by the magnitude of the rdt then I +automatically + + align:start position:0% +automatically + + + align:start position:0% +automatically +get the unit tangent Vector is that + + align:start position:0% +get the unit tangent Vector is that + + + align:start position:0% +get the unit tangent Vector is that +clear since no says no I assume it is + + align:start position:0% +clear since no says no I assume it is + + + align:start position:0% +clear since no says no I assume it is +clear look it we also showed last time + + align:start position:0% +clear look it we also showed last time + + + align:start position:0% +clear look it we also showed last time +that the magnitude of the rdt is speed + + align:start position:0% +that the magnitude of the rdt is speed + + + align:start position:0% +that the magnitude of the rdt is speed +along the curve speed along the curve + + align:start position:0% +along the curve speed along the curve + + + align:start position:0% +along the curve speed along the curve +happens to be called + + align:start position:0% +happens to be called + + + align:start position:0% +happens to be called +dstd so again another name for the unit + + align:start position:0% +dstd so again another name for the unit + + + align:start position:0% +dstd so again another name for the unit +tangent VOR is + + align:start position:0% +tangent VOR is + + + align:start position:0% +tangent VOR is +drdt divided by D + + align:start position:0% +drdt divided by D + + + align:start position:0% +drdt divided by D +sdt by the chain rule we can cancel DT + + align:start position:0% +sdt by the chain rule we can cancel DT + + + align:start position:0% +sdt by the chain rule we can cancel DT +and by the way notice the chain rule + + align:start position:0% +and by the way notice the chain rule + + + align:start position:0% +and by the way notice the chain rule +applies for Vector functions like this + + align:start position:0% +applies for Vector functions like this + + + align:start position:0% +applies for Vector functions like this +the same as it did part one of our + + align:start position:0% +the same as it did part one of our + + + align:start position:0% +the same as it did part one of our +course by virtue of what we showed in + + align:start position:0% +course by virtue of what we showed in + + + align:start position:0% +course by virtue of what we showed in +the last unit namely that every formula + + align:start position:0% +the last unit namely that every formula + + + align:start position:0% +the last unit namely that every formula +for derivatives that was true for scalar + + align:start position:0% +for derivatives that was true for scalar + + + align:start position:0% +for derivatives that was true for scalar +functions also happen to be true for + + align:start position:0% +functions also happen to be true for + + + align:start position:0% +functions also happen to be true for +what Vector functions of a scalar + + align:start position:0% +what Vector functions of a scalar + + + align:start position:0% +what Vector functions of a scalar +variable at any rate notice then by the + + align:start position:0% +variable at any rate notice then by the + + + align:start position:0% +variable at any rate notice then by the +chain rule another way of saying T is + + align:start position:0% +chain rule another way of saying T is + + + align:start position:0% +chain rule another way of saying T is +that it's the position Vector the + + align:start position:0% +that it's the position Vector the + + + align:start position:0% +that it's the position Vector the +derivative of the position Vector r with + + align:start position:0% +derivative of the position Vector r with + + + align:start position:0% +derivative of the position Vector r with +respect to the AR length s I'd like to + + align:start position:0% +respect to the AR length s I'd like to + + + align:start position:0% +respect to the AR length s I'd like to +make one comment on this it's important + + align:start position:0% +make one comment on this it's important + + + align:start position:0% +make one comment on this it's important +enough so I will also make this comment + + align:start position:0% +enough so I will also make this comment + + + align:start position:0% +enough so I will also make this comment +in the notes as well when we're doing + + align:start position:0% +in the notes as well when we're doing + + + align:start position:0% +in the notes as well when we're doing +the exercises the point is that in many + + align:start position:0% +the exercises the point is that in many + + + align:start position:0% +the exercises the point is that in many +textbooks they will define t by saying + + align:start position:0% +textbooks they will define t by saying + + + align:start position:0% +textbooks they will define t by saying +it's the RDS now 999 times out of a th + + align:start position:0% +it's the RDS now 999 times out of a th + + + align:start position:0% +it's the RDS now 999 times out of a th +in fact 999 times out of 998 even you + + align:start position:0% +in fact 999 times out of 998 even you + + + align:start position:0% +in fact 999 times out of 998 even you +will never be given r as a function of + + align:start position:0% +will never be given r as a function of + + + align:start position:0% +will never be given r as a function of +AR length in the real world in the real + + align:start position:0% +AR length in the real world in the real + + + align:start position:0% +AR length in the real world in the real +world R is a function of some parameter + + align:start position:0% +world R is a function of some parameter + + + align:start position:0% +world R is a function of some parameter +usually time and the trouble that + + align:start position:0% +usually time and the trouble that + + + align:start position:0% +usually time and the trouble that +happens is if you try to use this + + align:start position:0% +happens is if you try to use this + + + align:start position:0% +happens is if you try to use this +definition you find yourself trying to + + align:start position:0% +definition you find yourself trying to + + + align:start position:0% +definition you find yourself trying to +convert things into s and this makes + + align:start position:0% +convert things into s and this makes + + + align:start position:0% +convert things into s and this makes +sort of a mess for you the thing I would + + align:start position:0% +sort of a mess for you the thing I would + + + align:start position:0% +sort of a mess for you the thing I would +like to show you and by the way this + + align:start position:0% +like to show you and by the way this + + + align:start position:0% +like to show you and by the way this +does not depend on T standing for time + + align:start position:0% +does not depend on T standing for time + + + align:start position:0% +does not depend on T standing for time +if T is any variable and we show this in + + align:start position:0% +if T is any variable and we show this in + + + align:start position:0% +if T is any variable and we show this in +the notes and the exercises again if T + + align:start position:0% +the notes and the exercises again if T + + + align:start position:0% +the notes and the exercises again if T +is any Scala if you differentiate r with + + align:start position:0% +is any Scala if you differentiate r with + + + align:start position:0% +is any Scala if you differentiate r with +respect to that scalar and divide that + + align:start position:0% +respect to that scalar and divide that + + + align:start position:0% +respect to that scalar and divide that +result by the magnitude of this Vector + + align:start position:0% +result by the magnitude of this Vector + + + align:start position:0% +result by the magnitude of this Vector +you wind up with the unit tangent Vector + + align:start position:0% +you wind up with the unit tangent Vector + + + align:start position:0% +you wind up with the unit tangent Vector +in other words in a real life problem do + + align:start position:0% +in other words in a real life problem do + + + align:start position:0% +in other words in a real life problem do +not worrying about conver in R into a + + align:start position:0% +not worrying about conver in R into a + + + align:start position:0% +not worrying about conver in R into a +function of s simply differentiate r as + + align:start position:0% +function of s simply differentiate r as + + + align:start position:0% +function of s simply differentiate r as +it stands with respect to the given + + align:start position:0% +it stands with respect to the given + + + align:start position:0% +it stands with respect to the given +variable divide by the magnitude of the + + align:start position:0% +variable divide by the magnitude of the + + + align:start position:0% +variable divide by the magnitude of the +derivative and Presto you have the unit + + align:start position:0% +derivative and Presto you have the unit + + + align:start position:0% +derivative and Presto you have the unit +tangent Vector of course you may ask if + + align:start position:0% +tangent Vector of course you may ask if + + + align:start position:0% +tangent Vector of course you may ask if +it's so simple to do what I just said + + align:start position:0% +it's so simple to do what I just said + + + align:start position:0% +it's so simple to do what I just said +why is it that every book defines it + + align:start position:0% +why is it that every book defines it + + + align:start position:0% +why is it that every book defines it +this way the answer is rather + + align:start position:0% +this way the answer is rather + + + align:start position:0% +this way the answer is rather +interesting and that is we have just + + align:start position:0% +interesting and that is we have just + + + align:start position:0% +interesting and that is we have just +mentioned that we would like to believe + + align:start position:0% +mentioned that we would like to believe + + + align:start position:0% +mentioned that we would like to believe +that the shape of a curve depends only + + align:start position:0% +that the shape of a curve depends only + + + align:start position:0% +that the shape of a curve depends only +on the curve itself not on how we + + align:start position:0% +on the curve itself not on how we + + + align:start position:0% +on the curve itself not on how we +parameter it the beauty of this + + align:start position:0% +parameter it the beauty of this + + + align:start position:0% +parameter it the beauty of this +particular definition simply says uh + + align:start position:0% +particular definition simply says uh + + + align:start position:0% +particular definition simply says uh +look at the natural parameter is AR + + align:start position:0% +look at the natural parameter is AR + + + align:start position:0% +look at the natural parameter is AR +length namely AR length doesn't depend + + align:start position:0% +length namely AR length doesn't depend + + + align:start position:0% +length namely AR length doesn't depend +on any coordinate system given the curve + + align:start position:0% +on any coordinate system given the curve + + + align:start position:0% +on any coordinate system given the curve +start at any point you want and you can + + align:start position:0% +start at any point you want and you can + + + align:start position:0% +start at any point you want and you can +measure the Arc Length so s is a very + + align:start position:0% +measure the Arc Length so s is a very + + + align:start position:0% +measure the Arc Length so s is a very +natural parameter that does not depend + + align:start position:0% +natural parameter that does not depend + + + align:start position:0% +natural parameter that does not depend +on the coordinate system in other words + + align:start position:0% +on the coordinate system in other words + + + align:start position:0% +on the coordinate system in other words +by defining the unit tangent Vector to + + align:start position:0% +by defining the unit tangent Vector to + + + align:start position:0% +by defining the unit tangent Vector to +be Dr DS you have a beautiful + + align:start position:0% +be Dr DS you have a beautiful + + + align:start position:0% +be Dr DS you have a beautiful +philosophically pure + + align:start position:0% +philosophically pure + + + align:start position:0% +philosophically pure +mathematical definition because you have + + align:start position:0% +mathematical definition because you have + + + align:start position:0% +mathematical definition because you have +a definition which does not depend on + + align:start position:0% +a definition which does not depend on + + + align:start position:0% +a definition which does not depend on +any coordinate system or any unnatural + + align:start position:0% +any coordinate system or any unnatural + + + align:start position:0% +any coordinate system or any unnatural +parameter but in practice this is the + + align:start position:0% +parameter but in practice this is the + + + align:start position:0% +parameter but in practice this is the +way we compute the unit tangent + + align:start position:0% +way we compute the unit tangent + + + align:start position:0% +way we compute the unit tangent +Vector question that comes up is uh how + + align:start position:0% +Vector question that comes up is uh how + + + align:start position:0% +Vector question that comes up is uh how +do you find the vector n and I'm going + + align:start position:0% +do you find the vector n and I'm going + + + align:start position:0% +do you find the vector n and I'm going +to show you the traditional way of doing + + align:start position:0% +to show you the traditional way of doing + + + align:start position:0% +to show you the traditional way of doing +this before I Jazz it up with a more + + align:start position:0% +this before I Jazz it up with a more + + + align:start position:0% +this before I Jazz it up with a more +modern approach uh look at let's look at + + align:start position:0% +modern approach uh look at let's look at + + + align:start position:0% +modern approach uh look at let's look at +T over here let's call Fe the angle that + + align:start position:0% +T over here let's call Fe the angle that + + + align:start position:0% +T over here let's call Fe the angle that +the unit tangent Vector makes with the + + align:start position:0% +the unit tangent Vector makes with the + + + align:start position:0% +the unit tangent Vector makes with the +Curve here okay notice that in terms of + + align:start position:0% +Curve here okay notice that in terms of + + + align:start position:0% +Curve here okay notice that in terms of +this diagram since the unit tangent + + align:start position:0% +this diagram since the unit tangent + + + align:start position:0% +this diagram since the unit tangent +Vector has magnitude one the I component + + align:start position:0% +Vector has magnitude one the I component + + + align:start position:0% +Vector has magnitude one the I component +of it will be coine Fe and the J + + align:start position:0% +of it will be coine Fe and the J + + + align:start position:0% +of it will be coine Fe and the J +component will be sin Fe in other words + + align:start position:0% +component will be sin Fe in other words + + + align:start position:0% +component will be sin Fe in other words +T is equal to cine fi plus sin + + align:start position:0% +T is equal to cine fi plus sin + + + align:start position:0% +T is equal to cine fi plus sin +FJ let's just differentiate you see T is + + align:start position:0% +FJ let's just differentiate you see T is + + + align:start position:0% +FJ let's just differentiate you see T is +a function of Fe here let's just take + + align:start position:0% +a function of Fe here let's just take + + + align:start position:0% +a function of Fe here let's just take +the derivative of t with respect to Fe + + align:start position:0% +the derivative of t with respect to Fe + + + align:start position:0% +the derivative of t with respect to Fe +and we get right away see remember now + + align:start position:0% +and we get right away see remember now + + + align:start position:0% +and we get right away see remember now +we're getting the mileage out of this + + align:start position:0% +we're getting the mileage out of this + + + align:start position:0% +we're getting the mileage out of this +basic definition of derivative that + + align:start position:0% +basic definition of derivative that + + + align:start position:0% +basic definition of derivative that +hasn't changed since last time we just + + align:start position:0% +hasn't changed since last time we just + + + align:start position:0% +hasn't changed since last time we just +differentiate term by term here we get + + align:start position:0% +differentiate term by term here we get + + + align:start position:0% +differentiate term by term here we get +minus sin f i plus cosine + + align:start position:0% +minus sin f i plus cosine + + + align:start position:0% +minus sin f i plus cosine +FJ right away we observe that DTD Fe is + + align:start position:0% +FJ right away we observe that DTD Fe is + + + align:start position:0% +FJ right away we observe that DTD Fe is +still a unit Vector you see its + + align:start position:0% +still a unit Vector you see its + + + align:start position:0% +still a unit Vector you see its +components are minus sin Fe and cosine + + align:start position:0% +components are minus sin Fe and cosine + + + align:start position:0% +components are minus sin Fe and cosine +Fe so its magnitude is still one all + + align:start position:0% +Fe so its magnitude is still one all + + + align:start position:0% +Fe so its magnitude is still one all +right and its slope is cosine Fe over + + align:start position:0% +right and its slope is cosine Fe over + + + align:start position:0% +right and its slope is cosine Fe over +minus sin Fe which is the negative + + align:start position:0% +minus sin Fe which is the negative + + + align:start position:0% +minus sin Fe which is the negative +reciprocal of the slope here in other + + align:start position:0% +reciprocal of the slope here in other + + + align:start position:0% +reciprocal of the slope here in other +words what this shows us through the + + align:start position:0% +words what this shows us through the + + + align:start position:0% +words what this shows us through the +traditional approach is that whatever + + align:start position:0% +traditional approach is that whatever + + + align:start position:0% +traditional approach is that whatever +Vector DTD is it's a a unit Vector + + align:start position:0% +Vector DTD is it's a a unit Vector + + + align:start position:0% +Vector DTD is it's a a unit Vector +perpendicular to T by the way what that + + align:start position:0% +perpendicular to T by the way what that + + + align:start position:0% +perpendicular to T by the way what that +tells us right away is that DTD Fe must + + align:start position:0% +tells us right away is that DTD Fe must + + + align:start position:0% +tells us right away is that DTD Fe must +be either plus n or minus n before we go + + align:start position:0% +be either plus n or minus n before we go + + + align:start position:0% +be either plus n or minus n before we go +any further why because we already saw + + align:start position:0% +any further why because we already saw + + + align:start position:0% +any further why because we already saw +that positive n the vector that we + + align:start position:0% +that positive n the vector that we + + + align:start position:0% +that positive n the vector that we +called n was a positive 90° rotation of + + align:start position:0% +called n was a positive 90° rotation of + + + align:start position:0% +called n was a positive 90° rotation of +T if we only knew that the tdf was a + + align:start position:0% +T if we only knew that the tdf was a + + + align:start position:0% +T if we only knew that the tdf was a +positive 90° rotation rather than a + + align:start position:0% +positive 90° rotation rather than a + + + align:start position:0% +positive 90° rotation rather than a +negative 90° rotation would be home free + + align:start position:0% +negative 90° rotation would be home free + + + align:start position:0% +negative 90° rotation would be home free +and again the beauty of trigonometry in + + align:start position:0% +and again the beauty of trigonometry in + + + align:start position:0% +and again the beauty of trigonometry in +the non surveyor sense of the word + + align:start position:0% +the non surveyor sense of the word + + + align:start position:0% +the non surveyor sense of the word +analytically is + + align:start position:0% +analytically is + + + align:start position:0% +analytically is +this that sort of having a premonition + + align:start position:0% +this that sort of having a premonition + + + align:start position:0% +this that sort of having a premonition +of what we'd like to be true we simply + + align:start position:0% +of what we'd like to be true we simply + + + align:start position:0% +of what we'd like to be true we simply +ver verify the trigonometric identities + + align:start position:0% +ver verify the trigonometric identities + + + align:start position:0% +ver verify the trigonometric identities +that the cosine of f+ 90° is minus sin + + align:start position:0% +that the cosine of f+ 90° is minus sin + + + align:start position:0% +that the cosine of f+ 90° is minus sin +fee and the S of fe+ 90° is cosine fee + + align:start position:0% +fee and the S of fe+ 90° is cosine fee + + + align:start position:0% +fee and the S of fe+ 90° is cosine fee +so that the TD Fe is what it's cosine Fe + + align:start position:0% +so that the TD Fe is what it's cosine Fe + + + align:start position:0% +so that the TD Fe is what it's cosine Fe +plus 90° I plus s f plus 90° J and if we + + align:start position:0% +plus 90° I plus s f plus 90° J and if we + + + align:start position:0% +plus 90° I plus s f plus 90° J and if we +now compare this with this we notice + + align:start position:0% +now compare this with this we notice + + + align:start position:0% +now compare this with this we notice +that we have exactly the same expression + + align:start position:0% +that we have exactly the same expression + + + align:start position:0% +that we have exactly the same expression +except that the angle has been increased + + align:start position:0% +except that the angle has been increased + + + align:start position:0% +except that the angle has been increased +by a positive 90° in other words dtdv is + + align:start position:0% +by a positive 90° in other words dtdv is + + + align:start position:0% +by a positive 90° in other words dtdv is +a positive 90° rotation of T + + align:start position:0% +a positive 90° rotation of T + + + align:start position:0% +a positive 90° rotation of T +consequently DTD is the vector that + + align:start position:0% +consequently DTD is the vector that + + + align:start position:0% +consequently DTD is the vector that +we've called n okay that's + + align:start position:0% +we've called n okay that's + + + align:start position:0% +we've called n okay that's +DTD now let's go back to our kinematics + + align:start position:0% +DTD now let's go back to our kinematics + + + align:start position:0% +DTD now let's go back to our kinematics +we have t andn now let's talk about our + + align:start position:0% +we have t andn now let's talk about our + + + align:start position:0% +we have t andn now let's talk about our +velocity vector v where R is still some + + align:start position:0% +velocity vector v where R is still some + + + align:start position:0% +velocity vector v where R is still some +function of time by definition V is the + + align:start position:0% +function of time by definition V is the + + + align:start position:0% +function of time by definition V is the +rdt that isn't going to change V was the + + align:start position:0% +rdt that isn't going to change V was the + + + align:start position:0% +rdt that isn't going to change V was the +rdt last time it's going to be drdt this + + align:start position:0% +rdt last time it's going to be drdt this + + + align:start position:0% +rdt last time it's going to be drdt this +time it's going to be drdt whenever we + + align:start position:0% +time it's going to be drdt whenever we + + + align:start position:0% +time it's going to be drdt whenever we +want to use it the only difference is is + + align:start position:0% +want to use it the only difference is is + + + align:start position:0% +want to use it the only difference is is +that instead of expressing this in terms + + align:start position:0% +that instead of expressing this in terms + + + align:start position:0% +that instead of expressing this in terms +of I and J we now want to express it in + + align:start position:0% +of I and J we now want to express it in + + + align:start position:0% +of I and J we now want to express it in +terms of t and n and notice that since V + + align:start position:0% +terms of t and n and notice that since V + + + align:start position:0% +terms of t and n and notice that since V +has as its + + align:start position:0% +has as its + + + align:start position:0% +has as its +direction the direction of the tangent + + align:start position:0% +direction the direction of the tangent + + + align:start position:0% +direction the direction of the tangent +line and as its magnitude dsdt we saw + + align:start position:0% +line and as its magnitude dsdt we saw + + + align:start position:0% +line and as its magnitude dsdt we saw +that last time notice that in terms of t + + align:start position:0% +that last time notice that in terms of t + + + align:start position:0% +that last time notice that in terms of t +v is just a Scala multiple of the unit + + align:start position:0% +v is just a Scala multiple of the unit + + + align:start position:0% +v is just a Scala multiple of the unit +tangent Vector T and what Scala multiple + + align:start position:0% +tangent Vector T and what Scala multiple + + + align:start position:0% +tangent Vector T and what Scala multiple +is it it's the St all right all that + + align:start position:0% +is it it's the St all right all that + + + align:start position:0% +is it it's the St all right all that +says is what that V is the vector in the + + align:start position:0% +says is what that V is the vector in the + + + align:start position:0% +says is what that V is the vector in the +direction of T whose magnitude is the + + align:start position:0% +direction of T whose magnitude is the + + + align:start position:0% +direction of T whose magnitude is the +sdt which is speed along the curve I now + + align:start position:0% +sdt which is speed along the curve I now + + + align:start position:0% +sdt which is speed along the curve I now +want to find a a is acceleration it's + + align:start position:0% +want to find a a is acceleration it's + + + align:start position:0% +want to find a a is acceleration it's +the same acceleration that I was talking + + align:start position:0% +the same acceleration that I was talking + + + align:start position:0% +the same acceleration that I was talking +about before it's + + align:start position:0% +about before it's + + + align:start position:0% +about before it's +dvdt the only thing that's going to + + align:start position:0% +dvdt the only thing that's going to + + + align:start position:0% +dvdt the only thing that's going to +change now is I am not going going to + + align:start position:0% +change now is I am not going going to + + + align:start position:0% +change now is I am not going going to +change the acceleration vector I am + + align:start position:0% +change the acceleration vector I am + + + align:start position:0% +change the acceleration vector I am +going to change how it looks because now + + align:start position:0% +going to change how it looks because now + + + align:start position:0% +going to change how it looks because now +I'm going to try to find it in terms of + + align:start position:0% +I'm going to try to find it in terms of + + + align:start position:0% +I'm going to try to find it in terms of +t and n components so what do I do here + + align:start position:0% +t and n components so what do I do here + + + align:start position:0% +t and n components so what do I do here +look it look at this expression for V + + align:start position:0% +look it look at this expression for V + + + align:start position:0% +look it look at this expression for V +the sdt is speed along the curve that + + align:start position:0% +the sdt is speed along the curve that + + + align:start position:0% +the sdt is speed along the curve that +changes from time to time in general the + + align:start position:0% +changes from time to time in general the + + + align:start position:0% +changes from time to time in general the +unit tangent Vector T is also a variable + + align:start position:0% +unit tangent Vector T is also a variable + + + align:start position:0% +unit tangent Vector T is also a variable +function of T unless T happens to be a + + align:start position:0% +function of T unless T happens to be a + + + align:start position:0% +function of T unless T happens to be a +straight line through the origin namely + + align:start position:0% +straight line through the origin namely + + + align:start position:0% +straight line through the origin namely +notice that the unit tangent Vector even + + align:start position:0% +notice that the unit tangent Vector even + + + align:start position:0% +notice that the unit tangent Vector even +though it always has unit length + + align:start position:0% +though it always has unit length + + + align:start position:0% +though it always has unit length +changes its direction as we move along + + align:start position:0% +changes its direction as we move along + + + align:start position:0% +changes its direction as we move along +the curve so in other words both of + + align:start position:0% +the curve so in other words both of + + + align:start position:0% +the curve so in other words both of +these fact factors are functions of T + + align:start position:0% +these fact factors are functions of T + + + align:start position:0% +these fact factors are functions of T +consequently to differentiate this with + + align:start position:0% +consequently to differentiate this with + + + align:start position:0% +consequently to differentiate this with +respect to T we must use the product + + align:start position:0% +respect to T we must use the product + + + align:start position:0% +respect to T we must use the product +rule and the fact that all of our + + align:start position:0% +rule and the fact that all of our + + + align:start position:0% +rule and the fact that all of our +differentiation formulas are true for + + align:start position:0% +differentiation formulas are true for + + + align:start position:0% +differentiation formulas are true for +vector and scalar combinations as well + + align:start position:0% +vector and scalar combinations as well + + + align:start position:0% +vector and scalar combinations as well +as for scalers I now use the regular + + align:start position:0% +as for scalers I now use the regular + + + align:start position:0% +as for scalers I now use the regular +product rule namely it's the derivative + + align:start position:0% +product rule namely it's the derivative + + + align:start position:0% +product rule namely it's the derivative +of the first Factor times the second + + align:start position:0% +of the first Factor times the second + + + align:start position:0% +of the first Factor times the second +plus the first Factor times the + + align:start position:0% +plus the first Factor times the + + + align:start position:0% +plus the first Factor times the +derivative of the second and I now have + + align:start position:0% +derivative of the second and I now have + + + align:start position:0% +derivative of the second and I now have +a expressed in terms of two vectors T + + align:start position:0% +a expressed in terms of two vectors T + + + align:start position:0% +a expressed in terms of two vectors T +and the derivative of the unit Vector t + + align:start position:0% +and the derivative of the unit Vector t + + + align:start position:0% +and the derivative of the unit Vector t +with respect to time T and somehow or + + align:start position:0% +with respect to time T and somehow or + + + align:start position:0% +with respect to time T and somehow or +other all that's wrong here is I would + + align:start position:0% +other all that's wrong here is I would + + + align:start position:0% +other all that's wrong here is I would +like to get this thing expressed in + + align:start position:0% +like to get this thing expressed in + + + align:start position:0% +like to get this thing expressed in +terms of n you see when I'm working with + + align:start position:0% +terms of n you see when I'm working with + + + align:start position:0% +terms of n you see when I'm working with +t andn components I want my answer to + + align:start position:0% +t andn components I want my answer to + + + align:start position:0% +t andn components I want my answer to +depend on T andn now here's where I + + align:start position:0% +depend on T andn now here's where I + + + align:start position:0% +depend on T andn now here's where I +become very shrewd and by the way this + + align:start position:0% +become very shrewd and by the way this + + + align:start position:0% +become very shrewd and by the way this +is an Insight that you if you're going + + align:start position:0% +is an Insight that you if you're going + + + align:start position:0% +is an Insight that you if you're going +to pick it up at all you're either born + + align:start position:0% +to pick it up at all you're either born + + + align:start position:0% +to pick it up at all you're either born +with it or you pick it up with + + align:start position:0% +with it or you pick it up with + + + align:start position:0% +with it or you pick it up with +experience but you just have to work + + align:start position:0% +experience but you just have to work + + + align:start position:0% +experience but you just have to work +with these things there are tricks if + + align:start position:0% +with these things there are tricks if + + + align:start position:0% +with these things there are tricks if +you want I guess the no the novice calls + + align:start position:0% +you want I guess the no the novice calls + + + align:start position:0% +you want I guess the no the novice calls +them tricks the experts calls it calls + + align:start position:0% +them tricks the experts calls it calls + + + align:start position:0% +them tricks the experts calls it calls +it Keen analytical Insight the point is + + align:start position:0% +it Keen analytical Insight the point is + + + align:start position:0% +it Keen analytical Insight the point is +look at I want to get an N Out of This + + align:start position:0% +look at I want to get an N Out of This + + + align:start position:0% +look at I want to get an N Out of This +thing I already know how to express n in + + align:start position:0% +thing I already know how to express n in + + + align:start position:0% +thing I already know how to express n in +terms of DTD in fact n is DTD so what I + + align:start position:0% +terms of DTD in fact n is DTD so what I + + + align:start position:0% +terms of DTD in fact n is DTD so what I +do is I take DT DT and say let me write + + align:start position:0% +do is I take DT DT and say let me write + + + align:start position:0% +do is I take DT DT and say let me write +it so I can get a DTD factor out of + + align:start position:0% +it so I can get a DTD factor out of + + + align:start position:0% +it so I can get a DTD factor out of +this I also want everything to be in + + align:start position:0% +this I also want everything to be in + + + align:start position:0% +this I also want everything to be in +terms of O length so I can ultimately + + align:start position:0% +terms of O length so I can ultimately + + + align:start position:0% +terms of O length so I can ultimately +have an answer which doesn't depend on a + + align:start position:0% +have an answer which doesn't depend on a + + + align:start position:0% +have an answer which doesn't depend on a +coordinate system so what I really do is + + align:start position:0% +coordinate system so what I really do is + + + align:start position:0% +coordinate system so what I really do is +is I use the chain rule to express this + + align:start position:0% +is I use the chain rule to express this + + + align:start position:0% +is I use the chain rule to express this +factor in terms of what these three + + align:start position:0% +factor in terms of what these three + + + align:start position:0% +factor in terms of what these three +factors you see according to the chain + + align:start position:0% +factors you see according to the chain + + + align:start position:0% +factors you see according to the chain +rule the DFE here cancels the DFE here + + align:start position:0% +rule the DFE here cancels the DFE here + + + align:start position:0% +rule the DFE here cancels the DFE here +the DS here cancels the DS here and all + + align:start position:0% +the DS here cancels the DS here and all + + + align:start position:0% +the DS here cancels the DS here and all +I'm saying is that the tdt can be + + align:start position:0% +I'm saying is that the tdt can be + + + align:start position:0% +I'm saying is that the tdt can be +written as DTD time D fds time D sdt now + + align:start position:0% +written as DTD time D fds time D sdt now + + + align:start position:0% +written as DTD time D fds time D sdt now +we're in very good shape you see DTD we + + align:start position:0% +we're in very good shape you see DTD we + + + align:start position:0% +we're in very good shape you see DTD we +already know is + + align:start position:0% +already know is + + + align:start position:0% +already know is +n and D + + align:start position:0% +n and D + + + align:start position:0% +n and D +sdt we already know can go with this and + + align:start position:0% +sdt we already know can go with this and + + + align:start position:0% +sdt we already know can go with this and +the only new thing that we have to worry + + align:start position:0% +the only new thing that we have to worry + + + align:start position:0% +the only new thing that we have to worry +about is what is D + + align:start position:0% + + + + align:start position:0% + +fds see again what what so often happens + + align:start position:0% +fds see again what what so often happens + + + align:start position:0% +fds see again what what so often happens +you apply logic you get to a certain + + align:start position:0% +you apply logic you get to a certain + + + align:start position:0% +you apply logic you get to a certain +inescapable conclusion and then if you + + align:start position:0% +inescapable conclusion and then if you + + + align:start position:0% +inescapable conclusion and then if you +have brand new terms you have a choice + + align:start position:0% +have brand new terms you have a choice + + + align:start position:0% +have brand new terms you have a choice +between doing what saying I don't like + + align:start position:0% +between doing what saying I don't like + + + align:start position:0% +between doing what saying I don't like +the new terms I'm going to throw them + + align:start position:0% +the new terms I'm going to throw them + + + align:start position:0% +the new terms I'm going to throw them +away or saying I like the result I had + + align:start position:0% +away or saying I like the result I had + + + align:start position:0% +away or saying I like the result I had +better interpret what this new term + + align:start position:0% +better interpret what this new term + + + align:start position:0% +better interpret what this new term +means all I want to show you is is that + + align:start position:0% +means all I want to show you is is that + + + align:start position:0% +means all I want to show you is is that +the fds has a very natural + + align:start position:0% +the fds has a very natural + + + align:start position:0% +the fds has a very natural +interpretation namely what is + + align:start position:0% +interpretation namely what is + + + align:start position:0% +interpretation namely what is +DDS let me tell you what it's called + + align:start position:0% +DDS let me tell you what it's called + + + align:start position:0% +DDS let me tell you what it's called +first it's usually denoted by the Greek + + align:start position:0% +first it's usually denoted by the Greek + + + align:start position:0% +first it's usually denoted by the Greek +letter Kappa and it's called curvature + + align:start position:0% +letter Kappa and it's called curvature + + + align:start position:0% +letter Kappa and it's called curvature +it's reciprocal one over Kappa is + + align:start position:0% +it's reciprocal one over Kappa is + + + align:start position:0% +it's reciprocal one over Kappa is +usually denoted by row and it's called + + align:start position:0% +usually denoted by row and it's called + + + align:start position:0% +usually denoted by row and it's called +the radius of curvature and I give you + + align:start position:0% +the radius of curvature and I give you + + + align:start position:0% +the radius of curvature and I give you +plenty of drill on this stuff I just + + align:start position:0% +plenty of drill on this stuff I just + + + align:start position:0% +plenty of drill on this stuff I just +want to mention what these words are now + + align:start position:0% +want to mention what these words are now + + + align:start position:0% +want to mention what these words are now +in fact part of the drill is that the + + align:start position:0% +in fact part of the drill is that the + + + align:start position:0% +in fact part of the drill is that the +fds is not a very convenient thing to + + align:start position:0% +fds is not a very convenient thing to + + + align:start position:0% +fds is not a very convenient thing to +compute usually you're given Y is some + + align:start position:0% +compute usually you're given Y is some + + + align:start position:0% +compute usually you're given Y is some +function of X and many of the drill + + align:start position:0% +function of X and many of the drill + + + align:start position:0% +function of X and many of the drill +problems that we have in calculus ask + + align:start position:0% +problems that we have in calculus ask + + + align:start position:0% +problems that we have in calculus ask +questions like how do you express D fds + + align:start position:0% +questions like how do you express D fds + + + align:start position:0% +questions like how do you express D fds +in terms of Y Dy DX etc those are + + align:start position:0% +in terms of Y Dy DX etc those are + + + align:start position:0% +in terms of Y Dy DX etc those are +problems that we can get into in more + + align:start position:0% +problems that we can get into in more + + + align:start position:0% +problems that we can get into in more +detail as we do the exercises but all I + + align:start position:0% +detail as we do the exercises but all I + + + align:start position:0% +detail as we do the exercises but all I +wanted to do in this lecture is to show + + align:start position:0% +wanted to do in this lecture is to show + + + align:start position:0% +wanted to do in this lecture is to show +you why D fds is such a natural thing + + align:start position:0% +you why D fds is such a natural thing + + + align:start position:0% +you why D fds is such a natural thing +look at the curve + + align:start position:0% +look at the curve + + + align:start position:0% +look at the curve +S as you move along this curve notice + + align:start position:0% +S as you move along this curve notice + + + align:start position:0% +S as you move along this curve notice +that the change in Fe with respect to s + + align:start position:0% +that the change in Fe with respect to s + + + align:start position:0% +that the change in Fe with respect to s +in a way tells you how the shape of the + + align:start position:0% +in a way tells you how the shape of the + + + align:start position:0% +in a way tells you how the shape of the +curve is changing in other words DDS + + align:start position:0% +curve is changing in other words DDS + + + align:start position:0% +curve is changing in other words DDS +measures how what could be a more + + align:start position:0% +measures how what could be a more + + + align:start position:0% +measures how what could be a more +natural word than curvature see as Fe + + align:start position:0% +natural word than curvature see as Fe + + + align:start position:0% +natural word than curvature see as Fe +changes as you move along the curve + + align:start position:0% +changes as you move along the curve + + + align:start position:0% +changes as you move along the curve +that's measuring how your curvature is + + align:start position:0% +that's measuring how your curvature is + + + align:start position:0% +that's measuring how your curvature is +changing as an extreme extreme case + + align:start position:0% +changing as an extreme extreme case + + + align:start position:0% +changing as an extreme extreme case +notice if the curve were straight line D + + align:start position:0% +notice if the curve were straight line D + + + align:start position:0% +notice if the curve were straight line D +fds would be + + align:start position:0% +fds would be + + + align:start position:0% +fds would be +zero right because Fe would be a + + align:start position:0% +zero right because Fe would be a + + + align:start position:0% +zero right because Fe would be a +constant D fds would be zero and the + + align:start position:0% +constant D fds would be zero and the + + + align:start position:0% +constant D fds would be zero and the +curvature of a straight line should be + + align:start position:0% +curvature of a straight line should be + + + align:start position:0% +curvature of a straight line should be +zero at any rate one defines D fds to be + + align:start position:0% +zero at any rate one defines D fds to be + + + align:start position:0% +zero at any rate one defines D fds to be +the curvature and in fact to play it + + align:start position:0% +the curvature and in fact to play it + + + align:start position:0% +the curvature and in fact to play it +safely since s can have two different + + align:start position:0% +safely since s can have two different + + + align:start position:0% +safely since s can have two different +senses in other words why couldn't + + align:start position:0% +senses in other words why couldn't + + + align:start position:0% +senses in other words why couldn't +somebody else say why don't you go this + + align:start position:0% +somebody else say why don't you go this + + + align:start position:0% +somebody else say why don't you go this +way along the curve I don't know what + + align:start position:0% +way along the curve I don't know what + + + align:start position:0% +way along the curve I don't know what +the sense is usually what one does to + + align:start position:0% +the sense is usually what one does to + + + align:start position:0% +the sense is usually what one does to +play it safe is we put the absolute + + align:start position:0% +play it safe is we put the absolute + + + align:start position:0% +play it safe is we put the absolute +value signs around the D fds and just + + align:start position:0% +value signs around the D fds and just + + + align:start position:0% +value signs around the D fds and just +call the magnitude the curvature and the + + align:start position:0% +call the magnitude the curvature and the + + + align:start position:0% +call the magnitude the curvature and the +punch line is that once I call D fds the + + align:start position:0% +punch line is that once I call D fds the + + + align:start position:0% +punch line is that once I call D fds the +curvature what I wind up with is what + + align:start position:0% +curvature what I wind up with is what + + + align:start position:0% +curvature what I wind up with is what +just substituting in here now the + + align:start position:0% +just substituting in here now the + + + align:start position:0% +just substituting in here now the +acceleration vector is d2s DT ^ 2 * t + + align:start position:0% +acceleration vector is d2s DT ^ 2 * t + + + align:start position:0% +acceleration vector is d2s DT ^ 2 * t +plus Kappa dsdt ^ 2 * n by the way this + + align:start position:0% +plus Kappa dsdt ^ 2 * n by the way this + + + align:start position:0% +plus Kappa dsdt ^ 2 * n by the way this +entire recipe is derived in the text I + + align:start position:0% +entire recipe is derived in the text I + + + align:start position:0% +entire recipe is derived in the text I +have you do it again as a learning + + align:start position:0% +have you do it again as a learning + + + align:start position:0% +have you do it again as a learning +exercise because I want you to practice + + align:start position:0% +exercise because I want you to practice + + + align:start position:0% +exercise because I want you to practice +with this and I make additional comments + + align:start position:0% +with this and I make additional comments + + + align:start position:0% +with this and I make additional comments +on this in the notes the uh the textbook + + align:start position:0% +on this in the notes the uh the textbook + + + align:start position:0% +on this in the notes the uh the textbook +makes additional comments on it in the + + align:start position:0% +makes additional comments on it in the + + + align:start position:0% +makes additional comments on it in the +text which is where you'd expect it to + + align:start position:0% +text which is where you'd expect it to + + + align:start position:0% +text which is where you'd expect it to +be and all I want you to see is that + + align:start position:0% +be and all I want you to see is that + + + align:start position:0% +be and all I want you to see is that +this is the same acceleration vector + + align:start position:0% +this is the same acceleration vector + + + align:start position:0% +this is the same acceleration vector +that we were talking about in the last + + align:start position:0% +that we were talking about in the last + + + align:start position:0% +that we were talking about in the last +lecture only now we're talking about how + + align:start position:0% +lecture only now we're talking about how + + + align:start position:0% +lecture only now we're talking about how +it looks in terms of tangential and + + align:start position:0% +it looks in terms of tangential and + + + align:start position:0% +it looks in terms of tangential and +normal components instead of I and J + + align:start position:0% +normal components instead of I and J + + + align:start position:0% +normal components instead of I and J +components okay and what's so good about + + align:start position:0% +components okay and what's so good about + + + align:start position:0% +components okay and what's so good about +tangential and normal what's so good + + align:start position:0% +tangential and normal what's so good + + + align:start position:0% +tangential and normal what's so good +about tangential and normal is that + + align:start position:0% +about tangential and normal is that + + + align:start position:0% +about tangential and normal is that +you're now moving along the curve rather + + align:start position:0% +you're now moving along the curve rather + + + align:start position:0% +you're now moving along the curve rather +than with respect to some isolated x and + + align:start position:0% +than with respect to some isolated x and + + + align:start position:0% +than with respect to some isolated x and +y coordinate system + + align:start position:0% +y coordinate system + + + align:start position:0% +y coordinate system +by the way in the last unit we showed a + + align:start position:0% +by the way in the last unit we showed a + + + align:start position:0% +by the way in the last unit we showed a +rather interesting result that if T was + + align:start position:0% +rather interesting result that if T was + + + align:start position:0% +rather interesting result that if T was +any function Vector function of the + + align:start position:0% +any function Vector function of the + + + align:start position:0% +any function Vector function of the +Scala X and the magnitude of T was a + + align:start position:0% +Scala X and the magnitude of T was a + + + align:start position:0% +Scala X and the magnitude of T was a +constant then DT DX was perpendicular to + + align:start position:0% +constant then DT DX was perpendicular to + + + align:start position:0% +constant then DT DX was perpendicular to +T that was an exercise in the last unit + + align:start position:0% +T that was an exercise in the last unit + + + align:start position:0% +T that was an exercise in the last unit +now the interesting point is that the + + align:start position:0% +now the interesting point is that the + + + align:start position:0% +now the interesting point is that the +modern approach to calculus says this + + align:start position:0% +modern approach to calculus says this + + + align:start position:0% +modern approach to calculus says this +why should we single out the XY plane + + align:start position:0% +why should we single out the XY plane + + + align:start position:0% +why should we single out the XY plane +after all you can be given a particle + + align:start position:0% +after all you can be given a particle + + + align:start position:0% +after all you can be given a particle +moving through space or you can be using + + align:start position:0% +moving through space or you can be using + + + align:start position:0% +moving through space or you can be using +a different coordinate system the + + align:start position:0% +a different coordinate system the + + + align:start position:0% +a different coordinate system the +natural parameter is Arc Length + + align:start position:0% +natural parameter is Arc Length + + + align:start position:0% +natural parameter is Arc Length +consequently the modern approach never + + align:start position:0% +consequently the modern approach never + + + align:start position:0% +consequently the modern approach never +talks about the angle Fe or anything + + align:start position:0% +talks about the angle Fe or anything + + + align:start position:0% +talks about the angle Fe or anything +like this the modern approach simply + + align:start position:0% +like this the modern approach simply + + + align:start position:0% +like this the modern approach simply +says this look at Define the unit + + align:start position:0% +says this look at Define the unit + + + align:start position:0% +says this look at Define the unit +tangent Vector as + + align:start position:0% +tangent Vector as + + + align:start position:0% +tangent Vector as +before since the TDS because the + + align:start position:0% +before since the TDS because the + + + align:start position:0% +before since the TDS because the +magnitude of T is a constant since the + + align:start position:0% +magnitude of T is a constant since the + + + align:start position:0% +magnitude of T is a constant since the +TDs is already perpendicular to T let's + + align:start position:0% +TDs is already perpendicular to T let's + + + align:start position:0% +TDs is already perpendicular to T let's +define a second Vector n to be the + + align:start position:0% +define a second Vector n to be the + + + align:start position:0% +define a second Vector n to be the +magnit to be dtds divided by its + + align:start position:0% +magnit to be dtds divided by its + + + align:start position:0% +magnit to be dtds divided by its +magnitude again the same old trick what + + align:start position:0% +magnitude again the same old trick what + + + align:start position:0% +magnitude again the same old trick what +have we done here we have simply taken + + align:start position:0% +have we done here we have simply taken + + + align:start position:0% +have we done here we have simply taken +dtds which we know is perpendicular to T + + align:start position:0% +dtds which we know is perpendicular to T + + + align:start position:0% +dtds which we know is perpendicular to T +any Scala multiple of dtds will still be + + align:start position:0% +any Scala multiple of dtds will still be + + + align:start position:0% +any Scala multiple of dtds will still be +perpendicular to T but now this is what + + align:start position:0% +perpendicular to T but now this is what + + + align:start position:0% +perpendicular to T but now this is what +it's a unit Vector because we've divided + + align:start position:0% +it's a unit Vector because we've divided + + + align:start position:0% +it's a unit Vector because we've divided +this vector by its magnitude therefore N + + align:start position:0% +this vector by its magnitude therefore N + + + align:start position:0% +this vector by its magnitude therefore N +is a unit vector and where is it it's + + align:start position:0% +is a unit vector and where is it it's + + + align:start position:0% +is a unit vector and where is it it's +perpendicular to T if we now cross + + align:start position:0% +perpendicular to T if we now cross + + + align:start position:0% +perpendicular to T if we now cross +multiply notice that dtds is equal to + + align:start position:0% +multiply notice that dtds is equal to + + + align:start position:0% +multiply notice that dtds is equal to +the magnitude of dtds time n see just + + align:start position:0% +the magnitude of dtds time n see just + + + align:start position:0% +the magnitude of dtds time n see just +cross + + align:start position:0% +cross + + + align:start position:0% +cross +multiply I now claim that the magnitude + + align:start position:0% +multiply I now claim that the magnitude + + + align:start position:0% +multiply I now claim that the magnitude +of dtds is just D + + align:start position:0% +of dtds is just D + + + align:start position:0% +of dtds is just D +fds now why is that I guess I should + + align:start position:0% +fds now why is that I guess I should + + + align:start position:0% +fds now why is that I guess I should +have planned this better but let me come + + align:start position:0% +have planned this better but let me come + + + align:start position:0% +have planned this better but let me come +back to the previous board over here + + align:start position:0% +back to the previous board over here + + + align:start position:0% +back to the previous board over here +notice that since T is a constant Vector + + align:start position:0% +notice that since T is a constant Vector + + + align:start position:0% +notice that since T is a constant Vector +since T is a constant Vector how does it + + align:start position:0% +since T is a constant Vector how does it + + + align:start position:0% +since T is a constant Vector how does it +change it can't change in magnitude + + align:start position:0% +change it can't change in magnitude + + + align:start position:0% +change it can't change in magnitude +because it has constant magnitude + + align:start position:0% +because it has constant magnitude + + + align:start position:0% +because it has constant magnitude +therefore its only change must be due to + + align:start position:0% +therefore its only change must be due to + + + align:start position:0% +therefore its only change must be due to +Direction alone but the direction of T + + align:start position:0% +Direction alone but the direction of T + + + align:start position:0% +Direction alone but the direction of T +is measured by Fe in other words if the + + align:start position:0% +is measured by Fe in other words if the + + + align:start position:0% +is measured by Fe in other words if the +TDs is changing at all in other words if + + align:start position:0% +TDs is changing at all in other words if + + + align:start position:0% +TDs is changing at all in other words if +this is a variable it must be changing + + align:start position:0% +this is a variable it must be changing + + + align:start position:0% +this is a variable it must be changing +only in Direction because the magnitude + + align:start position:0% +only in Direction because the magnitude + + + align:start position:0% +only in Direction because the magnitude +of T is always one in other words T + + align:start position:0% +of T is always one in other words T + + + align:start position:0% +of T is always one in other words T +cannot change in magnitude it must + + align:start position:0% +cannot change in magnitude it must + + + align:start position:0% +cannot change in magnitude it must +therefore change only in Direction in + + align:start position:0% +therefore change only in Direction in + + + align:start position:0% +therefore change only in Direction in +other words the magnitude of the TDs is + + align:start position:0% +other words the magnitude of the TDs is + + + align:start position:0% +other words the magnitude of the TDs is +the same as the magnitude of the fds + + align:start position:0% +the same as the magnitude of the fds + + + align:start position:0% +the same as the magnitude of the fds +recall that we just defined the + + align:start position:0% +recall that we just defined the + + + align:start position:0% +recall that we just defined the +magnitude of the fds to be Kappa and + + align:start position:0% +magnitude of the fds to be Kappa and + + + align:start position:0% +magnitude of the fds to be Kappa and +therefore + + align:start position:0% +therefore + + + align:start position:0% +therefore +dtds is Kappa n the same way as in the + + align:start position:0% +dtds is Kappa n the same way as in the + + + align:start position:0% +dtds is Kappa n the same way as in the +traditional approach the beauty of this + + align:start position:0% +traditional approach the beauty of this + + + align:start position:0% +traditional approach the beauty of this +approach is that we're no longer + + align:start position:0% +approach is that we're no longer + + + align:start position:0% +approach is that we're no longer +restricted to to the XY plane we're not + + align:start position:0% +restricted to to the XY plane we're not + + + align:start position:0% +restricted to to the XY plane we're not +restricted to any plane we're not + + align:start position:0% +restricted to any plane we're not + + + align:start position:0% +restricted to any plane we're not +restricted to any coordinate system we + + align:start position:0% +restricted to any coordinate system we + + + align:start position:0% +restricted to any coordinate system we +can now in fact generalize this to go + + align:start position:0% +can now in fact generalize this to go + + + align:start position:0% +can now in fact generalize this to go +into three dimensions and in fact some + + align:start position:0% +into three dimensions and in fact some + + + align:start position:0% +into three dimensions and in fact some +of you will probably have enough + + align:start position:0% +of you will probably have enough + + + align:start position:0% +of you will probably have enough +difficulty with what we've done so far + + align:start position:0% +difficulty with what we've done so far + + + align:start position:0% +difficulty with what we've done so far +that you won't want to go into three + + align:start position:0% +that you won't want to go into three + + + align:start position:0% +that you won't want to go into three +dimensions what I've done is is I have + + align:start position:0% +dimensions what I've done is is I have + + + align:start position:0% +dimensions what I've done is is I have +made up an optional unit that follows + + align:start position:0% +made up an optional unit that follows + + + align:start position:0% +made up an optional unit that follows +this one a unit which has no lecture it + + align:start position:0% +this one a unit which has no lecture it + + + align:start position:0% +this one a unit which has no lecture it +simply has a batch of exercises for + + align:start position:0% +simply has a batch of exercises for + + + align:start position:0% +simply has a batch of exercises for +those who have massed the material in + + align:start position:0% +those who have massed the material in + + + align:start position:0% +those who have massed the material in +this unit and would like to see what + + align:start position:0% +this unit and would like to see what + + + align:start position:0% +this unit and would like to see what +happens in three-dimensional space and + + align:start position:0% +happens in three-dimensional space and + + + align:start position:0% +happens in three-dimensional space and +after all when you deal with real life + + align:start position:0% +after all when you deal with real life + + + align:start position:0% +after all when you deal with real life +orbit type problems and things like this + + align:start position:0% +orbit type problems and things like this + + + align:start position:0% +orbit type problems and things like this +notice that you do need the geometry of + + align:start position:0% +notice that you do need the geometry of + + + align:start position:0% +notice that you do need the geometry of +threedimensional space for this if you + + align:start position:0% +threedimensional space for this if you + + + align:start position:0% +threedimensional space for this if you +so desire you can then do the optional + + align:start position:0% +so desire you can then do the optional + + + align:start position:0% +so desire you can then do the optional +unit that's why it's called optional you + + align:start position:0% +unit that's why it's called optional you + + + align:start position:0% +unit that's why it's called optional you +can skip it if you want there's no loss + + align:start position:0% +can skip it if you want there's no loss + + + align:start position:0% +can skip it if you want there's no loss +of continuity if you should skip it but + + align:start position:0% +of continuity if you should skip it but + + + align:start position:0% +of continuity if you should skip it but +in that optional unit I devote + + align:start position:0% +in that optional unit I devote + + + align:start position:0% +in that optional unit I devote +computational drill to what happens when + + align:start position:0% +computational drill to what happens when + + + align:start position:0% +computational drill to what happens when +our curve happens to be a + + align:start position:0% +our curve happens to be a + + + align:start position:0% +our curve happens to be a +three-dimensional space curve in other + + align:start position:0% +three-dimensional space curve in other + + + align:start position:0% +three-dimensional space curve in other +words a curve that winds through space + + align:start position:0% +words a curve that winds through space + + + align:start position:0% +words a curve that winds through space +notice by the way that in the same way + + align:start position:0% +notice by the way that in the same way + + + align:start position:0% +notice by the way that in the same way +as + + align:start position:0% +as + + + align:start position:0% +as +before I can write R of T is X of TI + + align:start position:0% +before I can write R of T is X of TI + + + align:start position:0% +before I can write R of T is X of TI +plus y of TJ plus Z of TK where that is + + align:start position:0% +plus y of TJ plus Z of TK where that is + + + align:start position:0% +plus y of TJ plus Z of TK where that is +the vector form of the curve in + + align:start position:0% +the vector form of the curve in + + + align:start position:0% +the vector form of the curve in +cartisian coordinates given in scalar + + align:start position:0% +cartisian coordinates given in scalar + + + align:start position:0% +cartisian coordinates given in scalar +form by the three equations X is some + + align:start position:0% +form by the three equations X is some + + + align:start position:0% +form by the three equations X is some +function of t y is some function of t z + + align:start position:0% +function of t y is some function of t z + + + align:start position:0% +function of t y is some function of t z +is some function of T again my claim is + + align:start position:0% +is some function of T again my claim is + + + align:start position:0% +is some function of T again my claim is +that if I just take the RDS I still have + + align:start position:0% +that if I just take the RDS I still have + + + align:start position:0% +that if I just take the RDS I still have +the unit tangent vector and to see that + + align:start position:0% +the unit tangent vector and to see that + + + align:start position:0% +the unit tangent vector and to see that +just notice what we're saying here this + + align:start position:0% +just notice what we're saying here this + + + align:start position:0% +just notice what we're saying here this +is a space curve now I've taken a small + + align:start position:0% +is a space curve now I've taken a small + + + align:start position:0% +is a space curve now I've taken a small +segment of it his R his R plus Delta R + + align:start position:0% +segment of it his R his R plus Delta R + + + align:start position:0% +segment of it his R his R plus Delta R +so this difference is Delta R look what + + align:start position:0% +so this difference is Delta R look what + + + align:start position:0% +so this difference is Delta R look what +look what happens as you take Delta R + + align:start position:0% +look what happens as you take Delta R + + + align:start position:0% +look what happens as you take Delta R +and divide it by Delta s first of all + + align:start position:0% +and divide it by Delta s first of all + + + align:start position:0% +and divide it by Delta s first of all +the direction of Delta R does become the + + align:start position:0% +the direction of Delta R does become the + + + align:start position:0% +the direction of Delta R does become the +direction of the tangent line as Delta s + + align:start position:0% +direction of the tangent line as Delta s + + + align:start position:0% +direction of the tangent line as Delta s +approaches zero so certainly we can + + align:start position:0% +approaches zero so certainly we can + + + align:start position:0% +approaches zero so certainly we can +believe that the direction of drds is + + align:start position:0% +believe that the direction of drds is + + + align:start position:0% +believe that the direction of drds is +going to be the tangential direction + + align:start position:0% +going to be the tangential direction + + + align:start position:0% +going to be the tangential direction +also if we invoke + + align:start position:0% +also if we invoke + + + align:start position:0% +also if we invoke +the result of geometry that we talked + + align:start position:0% +the result of geometry that we talked + + + align:start position:0% +the result of geometry that we talked +about in part one of our course when we + + align:start position:0% +about in part one of our course when we + + + align:start position:0% +about in part one of our course when we +talked about Sin Theta over Theta as + + align:start position:0% +talked about Sin Theta over Theta as + + + align:start position:0% +talked about Sin Theta over Theta as +Theta approaches zero the length of the + + align:start position:0% +Theta approaches zero the length of the + + + align:start position:0% +Theta approaches zero the length of the +arc is approximately the length of the + + align:start position:0% +arc is approximately the length of the + + + align:start position:0% +arc is approximately the length of the +chord for small segments so therefore + + align:start position:0% +chord for small segments so therefore + + + align:start position:0% +chord for small segments so therefore +delt R over Delta s in magnitude + + align:start position:0% +delt R over Delta s in magnitude + + + align:start position:0% +delt R over Delta s in magnitude +approaches one in other words drds is + + align:start position:0% +approaches one in other words drds is + + + align:start position:0% +approaches one in other words drds is +still the unit tangent Vector the same + + align:start position:0% +still the unit tangent Vector the same + + + align:start position:0% +still the unit tangent Vector the same +as + + align:start position:0% +as + + + align:start position:0% +as +before again from a computational point + + align:start position:0% +before again from a computational point + + + align:start position:0% +before again from a computational point +of view to find the RDS you do not + + align:start position:0% +of view to find the RDS you do not + + + align:start position:0% +of view to find the RDS you do not +rewrite this in terms of s you simply do + + align:start position:0% +rewrite this in terms of s you simply do + + + align:start position:0% +rewrite this in terms of s you simply do +what you take the rdt the same as before + + align:start position:0% +what you take the rdt the same as before + + + align:start position:0% +what you take the rdt the same as before +divide by its magnitude and you + + align:start position:0% +divide by its magnitude and you + + + align:start position:0% +divide by its magnitude and you +automatically have + + align:start position:0% +automatically have + + + align:start position:0% +automatically have +drds similarly once T is given to find n + + align:start position:0% +drds similarly once T is given to find n + + + align:start position:0% +drds similarly once T is given to find n +you simply differentiate t with respect + + align:start position:0% +you simply differentiate t with respect + + + align:start position:0% +you simply differentiate t with respect +to S and divide it by its magnitude and + + align:start position:0% +to S and divide it by its magnitude and + + + align:start position:0% +to S and divide it by its magnitude and +again notice even though I've written it + + align:start position:0% +again notice even though I've written it + + + align:start position:0% +again notice even though I've written it +again if you look back to the first + + align:start position:0% +again if you look back to the first + + + align:start position:0% +again if you look back to the first +third of our Blackboard this is the same + + align:start position:0% +third of our Blackboard this is the same + + + align:start position:0% +third of our Blackboard this is the same +definition for n as before because our + + align:start position:0% +definition for n as before because our + + + align:start position:0% +definition for n as before because our +original definition did not specify that + + align:start position:0% +original definition did not specify that + + + align:start position:0% +original definition did not specify that +the curve had to be in a particular + + align:start position:0% +the curve had to be in a particular + + + align:start position:0% +the curve had to be in a particular +plane see same general definition so I + + align:start position:0% +plane see same general definition so I + + + align:start position:0% +plane see same general definition so I +now have t andn now what do TNN do T + + align:start position:0% +now have t andn now what do TNN do T + + + align:start position:0% +now have t andn now what do TNN do T +andn determine a plane it's a plane + + align:start position:0% +andn determine a plane it's a plane + + + align:start position:0% +andn determine a plane it's a plane +which we call the osculating plane to + + align:start position:0% +which we call the osculating plane to + + + align:start position:0% +which we call the osculating plane to +the curve that's the plane which sort of + + align:start position:0% +the curve that's the plane which sort of + + + align:start position:0% +the curve that's the plane which sort of +touches the curve at that particular + + align:start position:0% +touches the curve at that particular + + + align:start position:0% +touches the curve at that particular +moment remember this curve is winding + + align:start position:0% +moment remember this curve is winding + + + align:start position:0% +moment remember this curve is winding +through space and again this is done in + + align:start position:0% +through space and again this is done in + + + align:start position:0% +through space and again this is done in +more detail in the notes not quite as + + align:start position:0% +more detail in the notes not quite as + + + align:start position:0% +more detail in the notes not quite as +elegantly as going like this but the + + align:start position:0% +elegantly as going like this but the + + + align:start position:0% +elegantly as going like this but the +idea is you have this plane that's + + align:start position:0% +idea is you have this plane that's + + + align:start position:0% +idea is you have this plane that's +shifting along with the Curve + + align:start position:0% +shifting along with the Curve + + + align:start position:0% +shifting along with the Curve +the only thing that's missing that + + align:start position:0% +the only thing that's missing that + + + align:start position:0% +the only thing that's missing that +causes new complications when you deal + + align:start position:0% +causes new complications when you deal + + + align:start position:0% +causes new complications when you deal +in threedimensional space is that in the + + align:start position:0% +in threedimensional space is that in the + + + align:start position:0% +in threedimensional space is that in the +same way that TNN take the place of I + + align:start position:0% +same way that TNN take the place of I + + + align:start position:0% +same way that TNN take the place of I +and J in two space you need something + + align:start position:0% +and J in two space you need something + + + align:start position:0% +and J in two space you need something +that takes the place of K in + + align:start position:0% +that takes the place of K in + + + align:start position:0% +that takes the place of K in +three-dimensional space what we do is + + align:start position:0% +three-dimensional space what we do is + + + align:start position:0% +three-dimensional space what we do is +again look at the structure we mimic how + + align:start position:0% +again look at the structure we mimic how + + + align:start position:0% +again look at the structure we mimic how +K is related to I and J and invent a new + + align:start position:0% +K is related to I and J and invent a new + + + align:start position:0% +K is related to I and J and invent a new +Vector called the binormal hence + + align:start position:0% +Vector called the binormal hence + + + align:start position:0% +Vector called the binormal hence +abbreviated B which is simply defined to + + align:start position:0% +abbreviated B which is simply defined to + + + align:start position:0% +abbreviated B which is simply defined to +be T cross n the vector that you get by + + align:start position:0% +be T cross n the vector that you get by + + + align:start position:0% +be T cross n the vector that you get by +rotating the unit Vector T into the unit + + align:start position:0% +rotating the unit Vector T into the unit + + + align:start position:0% +rotating the unit Vector T into the unit +Vector n through the smaller namely the + + align:start position:0% +Vector n through the smaller namely the + + + align:start position:0% +Vector n through the smaller namely the +positive 90° uh angle all right now what + + align:start position:0% +positive 90° uh angle all right now what + + + align:start position:0% +positive 90° uh angle all right now what +is b b is perpendicular to both t and n + + align:start position:0% +is b b is perpendicular to both t and n + + + align:start position:0% +is b b is perpendicular to both t and n +in other words B is a vector which is + + align:start position:0% +in other words B is a vector which is + + + align:start position:0% +in other words B is a vector which is +perpendicular to the osculating plane + + align:start position:0% +perpendicular to the osculating plane + + + align:start position:0% +perpendicular to the osculating plane +since B always has a constant + + align:start position:0% +since B always has a constant + + + align:start position:0% +since B always has a constant +magnitude because t and n are always + + align:start position:0% +magnitude because t and n are always + + + align:start position:0% +magnitude because t and n are always +perpendicular see B always has magnitude + + align:start position:0% +perpendicular see B always has magnitude + + + align:start position:0% +perpendicular see B always has magnitude +one the point is that the BDS the + + align:start position:0% +one the point is that the BDS the + + + align:start position:0% +one the point is that the BDS the +magnitude the BDS measures the twist of + + align:start position:0% +magnitude the BDS measures the twist of + + + align:start position:0% +magnitude the BDS measures the twist of +the curve in other words that here this + + align:start position:0% +the curve in other words that here this + + + align:start position:0% +the curve in other words that here this +tangent plane following a point a + + align:start position:0% +tangent plane following a point a + + + align:start position:0% +tangent plane following a point a +particle along the curve and what you're + + align:start position:0% +particle along the curve and what you're + + + align:start position:0% +particle along the curve and what you're +saying is how fast the direction of that + + align:start position:0% +saying is how fast the direction of that + + + align:start position:0% +saying is how fast the direction of that +tangent plane is changing is measured by + + align:start position:0% +tangent plane is changing is measured by + + + align:start position:0% +tangent plane is changing is measured by +the BDS that is called The Twist I call + + align:start position:0% +the BDS that is called The Twist I call + + + align:start position:0% +the BDS that is called The Twist I call +it the twist I put it in quotation marks + + align:start position:0% +it the twist I put it in quotation marks + + + align:start position:0% +it the twist I put it in quotation marks +because nobody else calls it the twist + + align:start position:0% +because nobody else calls it the twist + + + align:start position:0% +because nobody else calls it the twist +the formal name is the torsion see this + + align:start position:0% +the formal name is the torsion see this + + + align:start position:0% +the formal name is the torsion see this +is called a torsion I talk about that + + align:start position:0% +is called a torsion I talk about that + + + align:start position:0% +is called a torsion I talk about that +more in the notes the point being by the + + align:start position:0% +more in the notes the point being by the + + + align:start position:0% +more in the notes the point being by the +way that notice that if the BDS happens + + align:start position:0% +way that notice that if the BDS happens + + + align:start position:0% +way that notice that if the BDS happens +to be zero in other words if B happens + + align:start position:0% +to be zero in other words if B happens + + + align:start position:0% +to be zero in other words if B happens +to be constant then the curve lies in + + align:start position:0% +to be constant then the curve lies in + + + align:start position:0% +to be constant then the curve lies in +the plane we certainly recognize that + + align:start position:0% +the plane we certainly recognize that + + + align:start position:0% +the plane we certainly recognize that +for example if the curve happened to be + + align:start position:0% +for example if the curve happened to be + + + align:start position:0% +for example if the curve happened to be +in the XY plane notice that if if t and + + align:start position:0% +in the XY plane notice that if if t and + + + align:start position:0% +in the XY plane notice that if if t and +n were were I and + + align:start position:0% +n were were I and + + + align:start position:0% +n were were I and +J I cross J would just be k b would then + + align:start position:0% +J I cross J would just be k b would then + + + align:start position:0% +J I cross J would just be k b would then +be a constant the derivative of a + + align:start position:0% +be a constant the derivative of a + + + align:start position:0% +be a constant the derivative of a +constant with respect to any variable is + + align:start position:0% +constant with respect to any variable is + + + align:start position:0% +constant with respect to any variable is +zero and therefore when the curve does + + align:start position:0% +zero and therefore when the curve does + + + align:start position:0% +zero and therefore when the curve does +lie on the plane the torsion The Twist + + align:start position:0% +lie on the plane the torsion The Twist + + + align:start position:0% +lie on the plane the torsion The Twist +is zero in other words the torsion does + + align:start position:0% +is zero in other words the torsion does + + + align:start position:0% +is zero in other words the torsion does +for threedimensional space what the + + align:start position:0% +for threedimensional space what the + + + align:start position:0% +for threedimensional space what the +curvature in a sense does for + + align:start position:0% +curvature in a sense does for + + + align:start position:0% +curvature in a sense does for +two-dimensional space at any rate our + + align:start position:0% +two-dimensional space at any rate our + + + align:start position:0% +two-dimensional space at any rate our +main aim is to get you familiar with + + align:start position:0% +main aim is to get you familiar with + + + align:start position:0% +main aim is to get you familiar with +some Vector calculus and if in doing + + align:start position:0% +some Vector calculus and if in doing + + + align:start position:0% +some Vector calculus and if in doing +this we can also help you learn how to + + align:start position:0% +this we can also help you learn how to + + + align:start position:0% +this we can also help you learn how to +use this stuff in some physical + + align:start position:0% +use this stuff in some physical + + + align:start position:0% +use this stuff in some physical +applications that happens to be frosting + + align:start position:0% +applications that happens to be frosting + + + align:start position:0% +applications that happens to be frosting +on the cake next time we are going to + + align:start position:0% +on the cake next time we are going to + + + align:start position:0% +on the cake next time we are going to +talk about the fact that we still have + + align:start position:0% +talk about the fact that we still have + + + align:start position:0% +talk about the fact that we still have +to invent additional coordinate systems + + align:start position:0% +to invent additional coordinate systems + + + align:start position:0% +to invent additional coordinate systems +that I and J isn't enough t and n isn't + + align:start position:0% +that I and J isn't enough t and n isn't + + + align:start position:0% +that I and J isn't enough t and n isn't +enough next time we're going to show why + + align:start position:0% +enough next time we're going to show why + + + align:start position:0% +enough next time we're going to show why +we need polar coordinates but we'll + + align:start position:0% +we need polar coordinates but we'll + + + align:start position:0% +we need polar coordinates but we'll +worry about that next time time until + + align:start position:0% +worry about that next time time until + + + align:start position:0% +worry about that next time time until +next time then + + align:start position:0% +next time then + + + align:start position:0% +next time then +goodbye funding for the publication of + + align:start position:0% +goodbye funding for the publication of + + + align:start position:0% +goodbye funding for the publication of +this video was provided by the Gabriella + + align:start position:0% +this video was provided by the Gabriella + + + align:start position:0% +this video was provided by the Gabriella +and Paul rosenbom + + align:start position:0% +and Paul rosenbom + + + align:start position:0% +and Paul rosenbom +foundation help ocw continue to provide + + align:start position:0% +foundation help ocw continue to provide + + + align:start position:0% +foundation help ocw continue to provide +free and open access to MIT courses by + + align:start position:0% +free and open access to MIT courses by + + + align:start position:0% +free and open access to MIT courses by +making a donation at ocw.mit.edu/donate \ No newline at end of file diff --git a/fASyFNukWP8.txt b/fASyFNukWP8.txt new file mode 100644 index 0000000000000000000000000000000000000000..66c1f3854619e28c4326e044a2cb817d5aed27be --- /dev/null +++ b/fASyFNukWP8.txt @@ -0,0 +1,347 @@ +The goal of the course is +basically to combine the + +materials that would be covered +in two different courses in + +mechanical or chemical +engineering, fluid dynamics and + +heat and mass transfer, +to try and package that for + +materials engineers within one +semester because the curriculum + +doesn't place enough emphasis on +this material to spread it out + +over two. +We try to teach all of the + +topics that are covered in both +of the courses in mechanical or + +chemical engineering within the +single semester. + +And that makes it, +of course, a challenge to + +teach, a challenge to learn the +sticking coefficient, + +the fraction that actually gets +absorbed may not be quite as + +high as in a two semester +sequence but that the goal is to + +teach all of that material. +The students are evaluated on + +two different criteria which are +the quizzes and exams of various + +types and the homework +assignments. + +I weight the homework +assignments very low in their + +overall grade, +just enough to give them an + +incentive to do the homework +assignments but not so much that + +we have to worry about are they +collaborating or not. + +Basically I don't care. +If three of them turn in + +identical homeworks just +handwritten with different pens + +that is great. +It makes life easier for the + +grader. +And so the homework assignments + +count for about 10% to 15% of +the grade. + +In terms of exams, +we have a math quiz at the + +beginning the purpose of which +largely is to help them to + +recall the math that they +learned two or three years ago + +as a freshman or a sophomore and +be able to use it for this + +course. +Then we have two exams during + +the semester. +Unlike other courses, + +I don't put them at the +one-third and two-third points + +of the semester. +I put them at the 40% and 80% + +points so that they can be +fairly tested on the first third + +of the exam with a little bit of +time to study. + +And then for the second and +third. + +And then the final exam at the +end. + +The final exam has two parts. +There is a closed book part and + +an open book part. +Each student must individually + +finish the closed book part. +And then they turn in that + +closed book part and they may +open their books and do the open + +book part. +So the closed book part is + +largely qualitative. +It is outline how you would + +solve this problem. +Or describe the difference + +between the turbulent and +laminar boundary layers. + +The open book part is then very +quantitative, + +very much centered around +problem-solving. + +And in every year that I have +taught this course, + +it has also included an essay +question which varies from as + +open-ended as describe a process +with which you are familiar and + +how the concepts learned in +3.185 help you to understand + +that process more thoroughly. +One other thing about the tests + +during the semester is that I +give them in class during the + +lecture period, +and then I grade them rapidly. + +And then the students, +during their recitation + +periods, are given the +opportunity to redo the parts + +that they got wrong. +So this serves a number of + +purposes. +One purpose is that it helps + +the students to really learn the +material very thoroughly. + +That if they didn't get it +right the first time, + +instead of just accepting a bad +grade and saying, + +oh well, I didn't learn that, +it forces them to really get a + +good handle on every single part +of that exam. + +And the average during the +first part is typically around + +70 or so. +The average after they have + +done the second part is +typically around 95 to 97. + +The 3.185 in-class portion is +composed of lectures and + +recitations. +There are three lectures per + +week and one recitation. +There is no lab directly + +associated with the course, +but I try to make my topics and + +examples relevant to the +material's project laboratory, + +which is 3.082, +which many students take at the + +same time or before or just +after it. + +In addition, +I have introduced a number of + +pedagogical changes over the +years. + +One of those is this +methodology of assessing how + +much the students understand not +only by a course evaluation at + +the end of the semester and then +modifying the course the + +following semester, +but introducing also a course + +evaluation halfway through the +semester. + +And then going beyond that by +picking up a practice which I + +learned from Lori Breslow of the +Teaching and Learning Labs, + +which has been adopted first by +the Aeronautics and Astronautics + +Department, a practice known as +Muddy Cards. + +Muddy Cards are index cards +which are handed out to students + +at the beginning of the lecture. +Students then take those cards + +and, over the course of the +lecture, will write down on them + +any questions that they have, +will write down what is the + +muddiest point of the lecture, +what is the least clear, + +the most difficult to +understand. + +They can then use that for +immediate feedback and right at + +the beginning of the next +lecture can go over the Muddy + +Cards and say, +OK, what did students not + +understand? +I can answer their questions + +and go over something that I +might not have explained very + +well. +And might even try an + +alternative way of explaining it +based on the way the question + +was worded. +One resource which is a part of + +OpenCourseWare that was put in +is a lecture that I give every + +fall semester on September 11th, +which is a September 11th + +memorial lecture. +This lecture is something which + +I began writing out in detail +somewhere around three months + +after the September 11th tragedy +in 2001. + +And what this lecture covers is +really how to place our work as + +engineers within the context of +society. + +What are some positive +contributions that we can make? + +What are some limits on those +contributions? + +As careful as one might be as +an engineer to try to focus on + +technologies which will +positively influence people's + +lives, the lesson of September +11th is that even a civilian + +jetliner built to bring people +together can be abused by people + +with sufficient hatred as a +weapon of mass destruction. + +So, therefore, +as engineers there is a need to + +try and steer our technologies +toward positive uses and also a + +need for faith. +In fact, they will actually be + +used for the purposes for which +we intend them. \ No newline at end of file diff --git a/fKaZeD70p8I.txt b/fKaZeD70p8I.txt new file mode 100644 index 0000000000000000000000000000000000000000..8caca9c4229e91219fcc4aeb33bdfeacae514144 --- /dev/null +++ b/fKaZeD70p8I.txt @@ -0,0 +1,7211 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +solo and welcome no particular + + align:start position:0% +solo and welcome no particular + + + align:start position:0% +solo and welcome no particular +announcements today other than in the + + align:start position:0% +announcements today other than in the + + + align:start position:0% +announcements today other than in the +unrelenting tradition of MIT we're going + + align:start position:0% +unrelenting tradition of MIT we're going + + + align:start position:0% +unrelenting tradition of MIT we're going +to Forge straight ahead and keep going + + align:start position:0% +to Forge straight ahead and keep going + + + align:start position:0% +to Forge straight ahead and keep going +with new material today we're going to + + align:start position:0% +with new material today we're going to + + + align:start position:0% +with new material today we're going to +talk about frequency response and just + + align:start position:0% +talk about frequency response and just + + + align:start position:0% +talk about frequency response and just +to set the context remember that last + + align:start position:0% +to set the context remember that last + + + align:start position:0% +to set the context remember that last +time we talked about a way to + + align:start position:0% +time we talked about a way to + + + align:start position:0% +time we talked about a way to +characterize a system in terms of a + + align:start position:0% +characterize a system in terms of a + + + align:start position:0% +characterize a system in terms of a +single signal by knowing the impulse + + align:start position:0% +single signal by knowing the impulse + + + align:start position:0% +single signal by knowing the impulse +response of a CT system you could + + align:start position:0% +response of a CT system you could + + + align:start position:0% +response of a CT system you could +characterize the response to any system + + align:start position:0% +characterize the response to any system + + + align:start position:0% +characterize the response to any system +by thinking about the convoy response to + + align:start position:0% +by thinking about the convoy response to + + + align:start position:0% +by thinking about the convoy response to +any signal by thinking about the output + + align:start position:0% +any signal by thinking about the output + + + align:start position:0% +any signal by thinking about the output +is the convolution of the impulse + + align:start position:0% +is the convolution of the impulse + + + align:start position:0% +is the convolution of the impulse +response with the input signal okay and + + align:start position:0% +response with the input signal okay and + + + align:start position:0% +response with the input signal okay and +that gave rise to a very compact way of + + align:start position:0% +that gave rise to a very compact way of + + + align:start position:0% +that gave rise to a very compact way of +thinking about the output of a system we + + align:start position:0% +thinking about the output of a system we + + + align:start position:0% +thinking about the output of a system we +think about the output Y is being X + + align:start position:0% +think about the output Y is being X + + + align:start position:0% +think about the output Y is being X +convulsed with H regardless of whether + + align:start position:0% +convulsed with H regardless of whether + + + align:start position:0% +convulsed with H regardless of whether +it's DT or CT and the ways the way that + + align:start position:0% +it's DT or CT and the ways the way that + + + align:start position:0% +it's DT or CT and the ways the way that +you carry out that convolution is in + + align:start position:0% +you carry out that convolution is in + + + align:start position:0% +you carry out that convolution is in +fact very similar in the two systems + + align:start position:0% +fact very similar in the two systems + + + align:start position:0% +fact very similar in the two systems +that way of thinking about a system is + + align:start position:0% +that way of thinking about a system is + + + align:start position:0% +that way of thinking about a system is +particularly useful for certain kinds of + + align:start position:0% +particularly useful for certain kinds of + + + align:start position:0% +particularly useful for certain kinds of +systems the examples we looked at last + + align:start position:0% +systems the examples we looked at last + + + align:start position:0% +systems the examples we looked at last +time we're optical in the case of an + + align:start position:0% +time we're optical in the case of an + + + align:start position:0% +time we're optical in the case of an +optical microscope it's very convenient + + align:start position:0% +optical microscope it's very convenient + + + align:start position:0% +optical microscope it's very convenient +to think about the effect of the + + align:start position:0% +to think about the effect of the + + + align:start position:0% +to think about the effect of the +microscope is to blur the target so + + align:start position:0% +microscope is to blur the target so + + + align:start position:0% +microscope is to blur the target so +whatever the target was it always comes + + align:start position:0% +whatever the target was it always comes + + + align:start position:0% +whatever the target was it always comes +out blurrier and that blur function is + + align:start position:0% +out blurrier and that blur function is + + + align:start position:0% +out blurrier and that blur function is +something that in optics we call the + + align:start position:0% +something that in optics we call the + + + align:start position:0% +something that in optics we call the +point spread function the point spread + + align:start position:0% +point spread function the point spread + + + align:start position:0% +point spread function the point spread +function in six double-o three terms is + + align:start position:0% +function in six double-o three terms is + + + align:start position:0% +function in six double-o three terms is +simply the three-dimensional impulse + + align:start position:0% +simply the three-dimensional impulse + + + align:start position:0% +simply the three-dimensional impulse +response we can think about three + + align:start position:0% +response we can think about three + + + align:start position:0% +response we can think about three +dimensions very similar to the way we + + align:start position:0% +dimensions very similar to the way we + + + align:start position:0% +dimensions very similar to the way we +think about one dimension and in fact in + + align:start position:0% +think about one dimension and in fact in + + + align:start position:0% +think about one dimension and in fact in +the next homework assignment which + + align:start position:0% +the next homework assignment which + + + align:start position:0% +the next homework assignment which +amazingly enough is already issued so + + align:start position:0% +amazingly enough is already issued so + + + align:start position:0% +amazingly enough is already issued so +the next homework assignment will think + + align:start position:0% +the next homework assignment will think + + + align:start position:0% +the next homework assignment will think +about two-dimensional signal processing + + align:start position:0% +about two-dimensional signal processing + + + align:start position:0% +about two-dimensional signal processing +and the difference between one and two + + align:start position:0% +and the difference between one and two + + + align:start position:0% +and the difference between one and two +is not very much in the difference + + align:start position:0% +is not very much in the difference + + + align:start position:0% +is not very much in the difference +between two and three is even less than + + align:start position:0% +between two and three is even less than + + + align:start position:0% +between two and three is even less than +the difference between one and two so + + align:start position:0% +the difference between one and two so + + + align:start position:0% +the difference between one and two so +we'll be able to think about an optical + + align:start position:0% +we'll be able to think about an optical + + + align:start position:0% +we'll be able to think about an optical +system purely in terms of the impulse + + align:start position:0% +system purely in terms of the impulse + + + align:start position:0% +system purely in terms of the impulse +response and that's particularly useful + + align:start position:0% +response and that's particularly useful + + + align:start position:0% +response and that's particularly useful +because it's so intuitive + + align:start position:0% +because it's so intuitive + + + align:start position:0% +because it's so intuitive +since the effect of the optical system + + align:start position:0% +since the effect of the optical system + + + align:start position:0% +since the effect of the optical system +is to blur the impulse response is a + + align:start position:0% +is to blur the impulse response is a + + + align:start position:0% +is to blur the impulse response is a +direct measure of how much it blurs + + align:start position:0% +direct measure of how much it blurs + + + align:start position:0% +direct measure of how much it blurs +that's true not only for microscopes but + + align:start position:0% +that's true not only for microscopes but + + + align:start position:0% +that's true not only for microscopes but +it's true for optics in general for the + + align:start position:0% +it's true for optics in general for the + + + align:start position:0% +it's true for optics in general for the +imaging with light it's a fundamental + + align:start position:0% +imaging with light it's a fundamental + + + align:start position:0% +imaging with light it's a fundamental +principle that derives from the + + align:start position:0% +principle that derives from the + + + align:start position:0% +principle that derives from the +wavelength the the coherent nature of + + align:start position:0% +wavelength the the coherent nature of + + + align:start position:0% +wavelength the the coherent nature of +light and here's an example taken from + + align:start position:0% +light and here's an example taken from + + + align:start position:0% +light and here's an example taken from +the hubble space telescope where we see + + align:start position:0% +the hubble space telescope where we see + + + align:start position:0% +the hubble space telescope where we see +that there's much more blurring from a + + align:start position:0% +that there's much more blurring from a + + + align:start position:0% +that there's much more blurring from a +ground-based microscope than there is + + align:start position:0% +ground-based microscope than there is + + + align:start position:0% +ground-based microscope than there is +from the Hubble simply because the + + align:start position:0% +from the Hubble simply because the + + + align:start position:0% +from the Hubble simply because the +blurring is the result of two things + + align:start position:0% +blurring is the result of two things + + + align:start position:0% +blurring is the result of two things +generally speaking if you have a + + align:start position:0% +generally speaking if you have a + + + align:start position:0% +generally speaking if you have a +ground-based system then there's two + + align:start position:0% +ground-based system then there's two + + + align:start position:0% +ground-based system then there's two +kinds of blurring that we usually think + + align:start position:0% +kinds of blurring that we usually think + + + align:start position:0% +kinds of blurring that we usually think +about blurring do the atmosphere + + align:start position:0% +about blurring do the atmosphere + + + align:start position:0% +about blurring do the atmosphere +balancing off the particles in the + + align:start position:0% +balancing off the particles in the + + + align:start position:0% +balancing off the particles in the +atmosphere and blurring due to the + + align:start position:0% +atmosphere and blurring due to the + + + align:start position:0% +atmosphere and blurring due to the +optics the same as it was in the + + align:start position:0% +optics the same as it was in the + + + align:start position:0% +optics the same as it was in the +microscope by going to space we + + align:start position:0% +microscope by going to space we + + + align:start position:0% +microscope by going to space we +completely eliminate the blurring in the + + align:start position:0% +completely eliminate the blurring in the + + + align:start position:0% +completely eliminate the blurring in the +atmosphere and so we're left with what + + align:start position:0% +atmosphere and so we're left with what + + + align:start position:0% +atmosphere and so we're left with what +can be a much sharper point spread + + align:start position:0% +can be a much sharper point spread + + + align:start position:0% +can be a much sharper point spread +function today we're going to look at a + + align:start position:0% +function today we're going to look at a + + + align:start position:0% +function today we're going to look at a +completely different way of thinking + + align:start position:0% +completely different way of thinking + + + align:start position:0% +completely different way of thinking +about a system rather than thinking what + + align:start position:0% +about a system rather than thinking what + + + align:start position:0% +about a system rather than thinking what +we will call in the time domain H of T + + align:start position:0% +we will call in the time domain H of T + + + align:start position:0% +we will call in the time domain H of T +was a function of time the impulse + + align:start position:0% +was a function of time the impulse + + + align:start position:0% +was a function of time the impulse +response was a function of time we think + + align:start position:0% +response was a function of time we think + + + align:start position:0% +response was a function of time we think +about that as time domain signal + + align:start position:0% +about that as time domain signal + + + align:start position:0% +about that as time domain signal +processing rather than thinking in the + + align:start position:0% +processing rather than thinking in the + + + align:start position:0% +processing rather than thinking in the +time today more thing about the + + align:start position:0% +time today more thing about the + + + align:start position:0% +time today more thing about the +frequency domain frequency domain just + + align:start position:0% +frequency domain frequency domain just + + + align:start position:0% +frequency domain frequency domain just +like time domain is very convenient for + + align:start position:0% +like time domain is very convenient for + + + align:start position:0% +like time domain is very convenient for +certain kinds of signal processing tasks + + align:start position:0% +certain kinds of signal processing tasks + + + align:start position:0% +certain kinds of signal processing tasks +one very natural example is audio you + + align:start position:0% +one very natural example is audio you + + + align:start position:0% +one very natural example is audio you +all have lots of familiarity with this + + align:start position:0% +all have lots of familiarity with this + + + align:start position:0% +all have lots of familiarity with this +what I'm going to do now to prove to you + + align:start position:0% +what I'm going to do now to prove to you + + + align:start position:0% +what I'm going to do now to prove to you +that you have great intuition is I'm + + align:start position:0% +that you have great intuition is I'm + + + align:start position:0% +that you have great intuition is I'm +going to play a clip followed by the + + align:start position:0% +going to play a clip followed by the + + + align:start position:0% +going to play a clip followed by the +same clip processed in four different in + + align:start position:0% +same clip processed in four different in + + + align:start position:0% +same clip processed in four different in +two different ways sorry clip so + + align:start position:0% +two different ways sorry clip so + + + align:start position:0% +two different ways sorry clip so +original clip 1 and clip 2 and I clip 1 + + align:start position:0% +original clip 1 and clip 2 and I clip 1 + + + align:start position:0% +original clip 1 and clip 2 and I clip 1 +and clip 2 will have some transformation + + align:start position:0% +and clip 2 will have some transformation + + + align:start position:0% +and clip 2 will have some transformation +applied to it either the high + + align:start position:0% +applied to it either the high + + + align:start position:0% +applied to it either the high +frequencies HF where the low frequencies + + align:start position:0% +frequencies HF where the low frequencies + + + align:start position:0% +frequencies HF where the low frequencies +L F will be increased up arrow or + + align:start position:0% +L F will be increased up arrow or + + + align:start position:0% +L F will be increased up arrow or +decrease down arrow ok declar + + align:start position:0% +decrease down arrow ok declar + + + align:start position:0% +decrease down arrow ok declar +so I'm going to first play the original + + align:start position:0% +so I'm going to first play the original + + + align:start position:0% +so I'm going to first play the original +then play clip one you should decide + + align:start position:0% +then play clip one you should decide + + + align:start position:0% +then play clip one you should decide +whether clip one sounds like the high + + align:start position:0% +whether clip one sounds like the high + + + align:start position:0% +whether clip one sounds like the high +frequencies are increased the high + + align:start position:0% +frequencies are increased the high + + + align:start position:0% +frequencies are increased the high +frequencies or decrease the low + + align:start position:0% +frequencies or decrease the low + + + align:start position:0% +frequencies or decrease the low +frequencies are increased the low + + align:start position:0% +frequencies are increased the low + + + align:start position:0% +frequencies are increased the low +frequencies are decrease or none of + + align:start position:0% +frequencies are decrease or none of + + + align:start position:0% +frequencies are decrease or none of +those then I'll play the original clip + + align:start position:0% +those then I'll play the original clip + + + align:start position:0% +those then I'll play the original clip +one original clip two so there's going + + align:start position:0% +one original clip two so there's going + + + align:start position:0% +one original clip two so there's going +to be two answers what happened to clip + + align:start position:0% +to be two answers what happened to clip + + + align:start position:0% +to be two answers what happened to clip +one and what happened to clip 2 okay + + align:start position:0% +one and what happened to clip 2 okay + + + align:start position:0% +one and what happened to clip 2 okay +nod your head yes everybody knows what's + + align:start position:0% +nod your head yes everybody knows what's + + + align:start position:0% +nod your head yes everybody knows what's +going to happen okay now everybody + + align:start position:0% +going to happen okay now everybody + + + align:start position:0% +going to happen okay now everybody +listening so here so you're supposed to + + align:start position:0% +listening so here so you're supposed to + + + align:start position:0% +listening so here so you're supposed to +figure out two different answers what + + align:start position:0% +figure out two different answers what + + + align:start position:0% +figure out two different answers what +happened to clip one and what happened + + align:start position:0% +happened to clip one and what happened + + + align:start position:0% +happened to clip one and what happened +to clip tool + + align:start position:0% + + + + align:start position:0% + +you + + align:start position:0% + + + + align:start position:0% + +okay what happened answer one answer 2x4 + + align:start position:0% +okay what happened answer one answer 2x4 + + + align:start position:0% +okay what happened answer one answer 2x4 +three answer for answer five raise your + + align:start position:0% +three answer for answer five raise your + + + align:start position:0% +three answer for answer five raise your +hand come on come on this is the part + + align:start position:0% +hand come on come on this is the part + + + align:start position:0% +hand come on come on this is the part +that you blame on your neighbour okay no + + align:start position:0% +that you blame on your neighbour okay no + + + align:start position:0% +that you blame on your neighbour okay no +don't talk to your neighbour that way + + align:start position:0% +don't talk to your neighbour that way + + + align:start position:0% +don't talk to your neighbour that way +you can blame it on your neighbor yeah I + + align:start position:0% +you can blame it on your neighbor yeah I + + + align:start position:0% +you can blame it on your neighbor yeah I +forgot that part + + align:start position:0% +forgot that part + + + align:start position:0% +forgot that part +okay talk to your neighbor + + align:start position:0% + + + + align:start position:0% + +okay everybody raise your hands what + + align:start position:0% +okay everybody raise your hands what + + + align:start position:0% +okay everybody raise your hands what +happened and if you're wrong just blame + + align:start position:0% +happened and if you're wrong just blame + + + align:start position:0% +happened and if you're wrong just blame +it on your neighbor just point to your + + align:start position:0% +it on your neighbor just point to your + + + align:start position:0% +it on your neighbor just point to your +neighbor as you raise your hand right + + align:start position:0% +neighbor as you raise your hand right + + + align:start position:0% +neighbor as you raise your hand right +and now I'll understand what you mean + + align:start position:0% + + + + align:start position:0% + +okay you're only about a half rate right + + align:start position:0% +okay you're only about a half rate right + + + align:start position:0% +okay you're only about a half rate right +you're supposed to be young people I'm + + align:start position:0% +you're supposed to be young people I'm + + + align:start position:0% +you're supposed to be young people I'm +old I'm not supposed to understand these + + align:start position:0% +old I'm not supposed to understand these + + + align:start position:0% +old I'm not supposed to understand these +things + + align:start position:0% +things + + + align:start position:0% +things +sure you're about half right so let's + + align:start position:0% +sure you're about half right so let's + + + align:start position:0% +sure you're about half right so let's +see maybe we can do it again + + align:start position:0% +see maybe we can do it again + + + align:start position:0% +see maybe we can do it again +so listen again + + align:start position:0% + + + + align:start position:0% + +you + + align:start position:0% + + + + align:start position:0% + +okay now the answer is perfectly clear + + align:start position:0% +okay now the answer is perfectly clear + + + align:start position:0% +okay now the answer is perfectly clear +everybody raise your hand what's the + + align:start position:0% +everybody raise your hand what's the + + + align:start position:0% +everybody raise your hand what's the +answer okay I know the problem the + + align:start position:0% +answer okay I know the problem the + + + align:start position:0% +answer okay I know the problem the +problem is that does anybody know the + + align:start position:0% +problem is that does anybody know the + + + align:start position:0% +problem is that does anybody know the +title to this piece that's the problem + + align:start position:0% +title to this piece that's the problem + + + align:start position:0% +title to this piece that's the problem +it's 1970s I wasn't thinking this was + + align:start position:0% +it's 1970s I wasn't thinking this was + + + align:start position:0% +it's 1970s I wasn't thinking this was +new in 1970 I heard it when I was in + + align:start position:0% +new in 1970 I heard it when I was in + + + align:start position:0% +new in 1970 I heard it when I was in +anyway okay the answer was the answers + + align:start position:0% +anyway okay the answer was the answers + + + align:start position:0% +anyway okay the answer was the answers +that way okay so the high frequencies in + + align:start position:0% +that way okay so the high frequencies in + + + align:start position:0% +that way okay so the high frequencies in +clip 1 were increased if you heard sort + + align:start position:0% +clip 1 were increased if you heard sort + + + align:start position:0% +clip 1 were increased if you heard sort +of a kid tapping in the background kind + + align:start position:0% +of a kid tapping in the background kind + + + align:start position:0% +of a kid tapping in the background kind +of a simple thing that was louder + + align:start position:0% +of a simple thing that was louder + + + align:start position:0% +of a simple thing that was louder +because the high frequencies were + + align:start position:0% +because the high frequencies were + + + align:start position:0% +because the high frequencies were +enhanced in the second part it sounded + + align:start position:0% +enhanced in the second part it sounded + + + align:start position:0% +enhanced in the second part it sounded +sort of similar except the volume was + + align:start position:0% +sort of similar except the volume was + + + align:start position:0% +sort of similar except the volume was +lower that's because I killed the low + + align:start position:0% +lower that's because I killed the low + + + align:start position:0% +lower that's because I killed the low +frequencies okay so in the first part + + align:start position:0% +frequencies okay so in the first part + + + align:start position:0% +frequencies okay so in the first part +the high frequencies were increased in + + align:start position:0% +the high frequencies were increased in + + + align:start position:0% +the high frequencies were increased in +the second part the low frequencies were + + align:start position:0% +the second part the low frequencies were + + + align:start position:0% +the second part the low frequencies were +decreased and I'll assume that if I had + + align:start position:0% +decreased and I'll assume that if I had + + + align:start position:0% +decreased and I'll assume that if I had +done updated music you would have got + + align:start position:0% +done updated music you would have got + + + align:start position:0% +done updated music you would have got +that so we'll assume that you all got a + + align:start position:0% +that so we'll assume that you all got a + + + align:start position:0% +that so we'll assume that you all got a +hundred percent correct and we'll go on + + align:start position:0% +hundred percent correct and we'll go on + + + align:start position:0% +hundred percent correct and we'll go on +so the yes please + + align:start position:0% + + + + align:start position:0% + +we'll be a little more thorough so the + + align:start position:0% +we'll be a little more thorough so the + + + align:start position:0% +we'll be a little more thorough so the +question was when I say increase in + + align:start position:0% +question was when I say increase in + + + align:start position:0% +question was when I say increase in +decrease what exactly do I mean by that + + align:start position:0% +decrease what exactly do I mean by that + + + align:start position:0% +decrease what exactly do I mean by that +what I meant was the magnitude of the + + align:start position:0% +what I meant was the magnitude of the + + + align:start position:0% +what I meant was the magnitude of the +frequency components was increase we'll + + align:start position:0% +frequency components was increase we'll + + + align:start position:0% +frequency components was increase we'll +be saying we'll be developing some + + align:start position:0% +be saying we'll be developing some + + + align:start position:0% +be saying we'll be developing some +language in there in the next 40 minutes + + align:start position:0% +language in there in the next 40 minutes + + + align:start position:0% +language in there in the next 40 minutes +that will make that statement more + + align:start position:0% +that will make that statement more + + + align:start position:0% +that will make that statement more +precise okay so the idea here was to + + align:start position:0% +precise okay so the idea here was to + + + align:start position:0% +precise okay so the idea here was to +give you an intuitive feeling for + + align:start position:0% +give you an intuitive feeling for + + + align:start position:0% +give you an intuitive feeling for +something that will make mathematically + + align:start position:0% +something that will make mathematically + + + align:start position:0% +something that will make mathematically +more rigorous as we go along by the end + + align:start position:0% +more rigorous as we go along by the end + + + align:start position:0% +more rigorous as we go along by the end +of the hour it should be completely + + align:start position:0% +of the hour it should be completely + + + align:start position:0% +of the hour it should be completely +clear what I mean by high frequencies + + align:start position:0% +clear what I mean by high frequencies + + + align:start position:0% +clear what I mean by high frequencies +increase that or low frequencies + + align:start position:0% +increase that or low frequencies + + + align:start position:0% +increase that or low frequencies +decreased if it's not tell me so the + + align:start position:0% +decreased if it's not tell me so the + + + align:start position:0% +decreased if it's not tell me so the +idea then in frequency analysis is to + + align:start position:0% +idea then in frequency analysis is to + + + align:start position:0% +idea then in frequency analysis is to +think about the input as frequencies + + align:start position:0% +think about the input as frequencies + + + align:start position:0% +think about the input as frequencies +think about the input being cos Omega T + + align:start position:0% +think about the input being cos Omega T + + + align:start position:0% +think about the input being cos Omega T +and then think about what the system + + align:start position:0% +and then think about what the system + + + align:start position:0% +and then think about what the system +would do to a signal that was of the + + align:start position:0% +would do to a signal that was of the + + + align:start position:0% +would do to a signal that was of the +form cos Omega T we'll find out as we go + + align:start position:0% +form cos Omega T we'll find out as we go + + + align:start position:0% +form cos Omega T we'll find out as we go +through the hour that the signal that + + align:start position:0% +through the hour that the signal that + + + align:start position:0% +through the hour that the signal that +comes out of a linear time-invariant + + align:start position:0% +comes out of a linear time-invariant + + + align:start position:0% +comes out of a linear time-invariant +system when the input is cos Omega T is + + align:start position:0% +system when the input is cos Omega T is + + + align:start position:0% +system when the input is cos Omega T is +also cos Omega T a frequent it's a + + align:start position:0% +also cos Omega T a frequent it's a + + + align:start position:0% +also cos Omega T a frequent it's a +signal with the same frequency however + + align:start position:0% +signal with the same frequency however + + + align:start position:0% +signal with the same frequency however +the amplitude and the phase so that + + align:start position:0% +the amplitude and the phase so that + + + align:start position:0% +the amplitude and the phase so that +which sort of addresses your question + + align:start position:0% +which sort of addresses your question + + + align:start position:0% +which sort of addresses your question +the amplitude and the phase can be + + align:start position:0% +the amplitude and the phase can be + + + align:start position:0% +the amplitude and the phase can be +different linear time-invariant systems + + align:start position:0% +different linear time-invariant systems + + + align:start position:0% +different linear time-invariant systems +can change the amplitude and phase but + + align:start position:0% +can change the amplitude and phase but + + + align:start position:0% +can change the amplitude and phase but +not the frequency of a pure sinusoid so + + align:start position:0% +not the frequency of a pure sinusoid so + + + align:start position:0% +not the frequency of a pure sinusoid so +then the trick in thinking about what a + + align:start position:0% +then the trick in thinking about what a + + + align:start position:0% +then the trick in thinking about what a +linear time-invariant system does to + + align:start position:0% +linear time-invariant system does to + + + align:start position:0% +linear time-invariant system does to +assign your sinusoid is thinking about + + align:start position:0% +assign your sinusoid is thinking about + + + align:start position:0% +assign your sinusoid is thinking about +how's the magnitude change and how's the + + align:start position:0% +how's the magnitude change and how's the + + + align:start position:0% +how's the magnitude change and how's the +frequency change so motivate that a + + align:start position:0% +frequency change so motivate that a + + + align:start position:0% +frequency change so motivate that a +little more I want to think about mass + + align:start position:0% +little more I want to think about mass + + + align:start position:0% +little more I want to think about mass +spring dashpot system we talked about + + align:start position:0% +spring dashpot system we talked about + + + align:start position:0% +spring dashpot system we talked about +this before if I think about the input + + align:start position:0% +this before if I think about the input + + + align:start position:0% +this before if I think about the input +of the system being the position of the + + align:start position:0% +of the system being the position of the + + + align:start position:0% +of the system being the position of the +top of the spring and if I think about + + align:start position:0% +top of the spring and if I think about + + + align:start position:0% +top of the spring and if I think about +the responses the system being the + + align:start position:0% +the responses the system being the + + + align:start position:0% +the responses the system being the +position of the mass then I can + + align:start position:0% +position of the mass then I can + + + align:start position:0% +position of the mass then I can +characterize that system as a linear + + align:start position:0% +characterize that system as a linear + + + align:start position:0% +characterize that system as a linear +time-invariant system and I can think + + align:start position:0% +time-invariant system and I can think + + + align:start position:0% +time-invariant system and I can think +about how does the amplitude change and + + align:start position:0% +about how does the amplitude change and + + + align:start position:0% +about how does the amplitude change and +how does the phase change as a function + + align:start position:0% +how does the phase change as a function + + + align:start position:0% +how does the phase change as a function +of frequency of the sinusoid okay + + align:start position:0% +of frequency of the sinusoid okay + + + align:start position:0% +of frequency of the sinusoid okay +is just like the music example but this + + align:start position:0% +is just like the music example but this + + + align:start position:0% +is just like the music example but this +time it's mechanical and what I want to + + align:start position:0% +time it's mechanical and what I want to + + + align:start position:0% +time it's mechanical and what I want to +do first is do a demonstration of + + align:start position:0% +do first is do a demonstration of + + + align:start position:0% +do first is do a demonstration of +figuring out the frequency response for + + align:start position:0% +figuring out the frequency response for + + + align:start position:0% +figuring out the frequency response for +a physical system okay so here's my mass + + align:start position:0% +a physical system okay so here's my mass + + + align:start position:0% +a physical system okay so here's my mass +spring dashpot hopefully you could all + + align:start position:0% +spring dashpot hopefully you could all + + + align:start position:0% +spring dashpot hopefully you could all +see that it is ten loops of a slinky + + align:start position:0% +see that it is ten loops of a slinky + + + align:start position:0% +see that it is ten loops of a slinky +connected up to a bolt and the idea is + + align:start position:0% +connected up to a bolt and the idea is + + + align:start position:0% +connected up to a bolt and the idea is +that I want to characterize how does the + + align:start position:0% +that I want to characterize how does the + + + align:start position:0% +that I want to characterize how does the +magnitude of the response change as a + + align:start position:0% +magnitude of the response change as a + + + align:start position:0% +magnitude of the response change as a +function of frequency and how does the + + align:start position:0% +function of frequency and how does the + + + align:start position:0% +function of frequency and how does the +phase of the response change as a + + align:start position:0% +phase of the response change as a + + + align:start position:0% +phase of the response change as a +function of frequency so if I turn it on + + align:start position:0% +function of frequency so if I turn it on + + + align:start position:0% +function of frequency so if I turn it on +to a low frequency okay so I've got a + + align:start position:0% +to a low frequency okay so I've got a + + + align:start position:0% +to a low frequency okay so I've got a +low voltage going to the motor the + + align:start position:0% +low voltage going to the motor the + + + align:start position:0% +low voltage going to the motor the +motors got a cam on it cams turning + + align:start position:0% +motors got a cam on it cams turning + + + align:start position:0% +motors got a cam on it cams turning +that's giving me sinusoidal motion up + + align:start position:0% +that's giving me sinusoidal motion up + + + align:start position:0% +that's giving me sinusoidal motion up +and down if you have very good eyes you + + align:start position:0% +and down if you have very good eyes you + + + align:start position:0% +and down if you have very good eyes you +should be able to see this little knot + + align:start position:0% +should be able to see this little knot + + + align:start position:0% +should be able to see this little knot +in the string is going up and down + + align:start position:0% +in the string is going up and down + + + align:start position:0% +in the string is going up and down +that's my input because the cam is not + + align:start position:0% +that's my input because the cam is not + + + align:start position:0% +that's my input because the cam is not +changing physically as I change the + + align:start position:0% +changing physically as I change the + + + align:start position:0% +changing physically as I change the +speed of the motor the amplitude of the + + align:start position:0% +speed of the motor the amplitude of the + + + align:start position:0% +speed of the motor the amplitude of the +sinusoidal + + align:start position:0% +sinusoidal + + + align:start position:0% +sinusoidal +that's the idea okay so you're supposed + + align:start position:0% +that's the idea okay so you're supposed + + + align:start position:0% +that's the idea okay so you're supposed +to do is this is X and that's why how + + align:start position:0% +to do is this is X and that's why how + + + align:start position:0% +to do is this is X and that's why how +would you characterize the magnitude of + + align:start position:0% +would you characterize the magnitude of + + + align:start position:0% +would you characterize the magnitude of +the response as the ratio of the + + align:start position:0% +the response as the ratio of the + + + align:start position:0% +the response as the ratio of the +magnitude of the input the output + + align:start position:0% + + + + align:start position:0% + +they're the same so the magnitude for + + align:start position:0% +they're the same so the magnitude for + + + align:start position:0% +they're the same so the magnitude for +this low frequency the magnitude is one + + align:start position:0% +this low frequency the magnitude is one + + + align:start position:0% +this low frequency the magnitude is one +about the phase relationship between the + + align:start position:0% +about the phase relationship between the + + + align:start position:0% +about the phase relationship between the +tow they're in phase with each other + + align:start position:0% +tow they're in phase with each other + + + align:start position:0% +tow they're in phase with each other +right when one goes up the other one + + align:start position:0% +right when one goes up the other one + + + align:start position:0% +right when one goes up the other one +goes up so at these low frequencies the + + align:start position:0% +goes up so at these low frequencies the + + + align:start position:0% +goes up so at these low frequencies the +magnitude starts out oh that one and the + + align:start position:0% +magnitude starts out oh that one and the + + + align:start position:0% +magnitude starts out oh that one and the +phase starts out at zero now I'll + + align:start position:0% +phase starts out at zero now I'll + + + align:start position:0% +phase starts out at zero now I'll +increase the speed + + align:start position:0% + + + + align:start position:0% + +now I what's the magnitude + + align:start position:0% + + + + align:start position:0% + +up up down don't have a clue don't care + + align:start position:0% +up up down don't have a clue don't care + + + align:start position:0% +up up down don't have a clue don't care +okay it's up a little bit so the + + align:start position:0% +okay it's up a little bit so the + + + align:start position:0% +okay it's up a little bit so the +magnitudes up a little bit how about the + + align:start position:0% +magnitudes up a little bit how about the + + + align:start position:0% +magnitudes up a little bit how about the +phase how about the phase it's kind of + + align:start position:0% +phase how about the phase it's kind of + + + align:start position:0% +phase how about the phase it's kind of +similar just put a big dot okay so now + + align:start position:0% +similar just put a big dot okay so now + + + align:start position:0% +similar just put a big dot okay so now +I'll turn up the speed a little more + + align:start position:0% + + + + align:start position:0% + +the magnitude might have changed up or + + align:start position:0% +the magnitude might have changed up or + + + align:start position:0% +the magnitude might have changed up or +down yeah well so he came up here + + align:start position:0% +down yeah well so he came up here + + + align:start position:0% +down yeah well so he came up here +someplace right how about the phase it's + + align:start position:0% +someplace right how about the phase it's + + + align:start position:0% +someplace right how about the phase it's +tons going completely out of phase so + + align:start position:0% +tons going completely out of phase so + + + align:start position:0% +tons going completely out of phase so +the phase in fact we will call that a + + align:start position:0% +the phase in fact we will call that a + + + align:start position:0% +the phase in fact we will call that a +lag but that's not perfectly clear now + + align:start position:0% +lag but that's not perfectly clear now + + + align:start position:0% +lag but that's not perfectly clear now +we'll see you later why I'm going to + + align:start position:0% +we'll see you later why I'm going to + + + align:start position:0% +we'll see you later why I'm going to +call it that what do you think will + + align:start position:0% +call it that what do you think will + + + align:start position:0% +call it that what do you think will +happen if I go further higher hit the + + align:start position:0% +happen if I go further higher hit the + + + align:start position:0% +happen if I go further higher hit the +roof right so if I go so this is four + + align:start position:0% +roof right so if I go so this is four + + + align:start position:0% +roof right so if I go so this is four +and a half golds if I go to a higher + + align:start position:0% +and a half golds if I go to a higher + + + align:start position:0% +and a half golds if I go to a higher +frequency funky why is it funky how to + + align:start position:0% +frequency funky why is it funky how to + + + align:start position:0% +frequency funky why is it funky how to +sing of what it's only got one input how + + align:start position:0% +sing of what it's only got one input how + + + align:start position:0% +sing of what it's only got one input how +can it be out of sync + + align:start position:0% + + + + align:start position:0% + +so it's remembering some of the response + + align:start position:0% +so it's remembering some of the response + + + align:start position:0% +so it's remembering some of the response +that it had before right so I really + + align:start position:0% +that it had before right so I really + + + align:start position:0% +that it had before right so I really +have to wait for the old response to die + + align:start position:0% +have to wait for the old response to die + + + align:start position:0% +have to wait for the old response to die +if I were to kill the input it wouldn't + + align:start position:0% +if I were to kill the input it wouldn't + + + align:start position:0% +if I were to kill the input it wouldn't +stop moving right away right so it's so + + align:start position:0% +stop moving right away right so it's so + + + align:start position:0% +stop moving right away right so it's so +the response to the previous input is + + align:start position:0% +the response to the previous input is + + + align:start position:0% +the response to the previous input is +interfering with the response to the + + align:start position:0% +interfering with the response to the + + + align:start position:0% +interfering with the response to the +current input if I wait long enough it + + align:start position:0% +current input if I wait long enough it + + + align:start position:0% +current input if I wait long enough it +ought to settle down okay magnitude up + + align:start position:0% +ought to settle down okay magnitude up + + + align:start position:0% +ought to settle down okay magnitude up +or down compared to one it's still down + + align:start position:0% +or down compared to one it's still down + + + align:start position:0% +or down compared to one it's still down +it's down even compared to one how about + + align:start position:0% +it's down even compared to one how about + + + align:start position:0% +it's down even compared to one how about +the phase so it's almost out of phase + + align:start position:0% +the phase so it's almost out of phase + + + align:start position:0% +the phase so it's almost out of phase +out of phase would be the top is going + + align:start position:0% +out of phase would be the top is going + + + align:start position:0% +out of phase would be the top is going +up while the bottom is going down so + + align:start position:0% +up while the bottom is going down so + + + align:start position:0% +up while the bottom is going down so +it's almost out of phase so the even + + align:start position:0% +it's almost out of phase so the even + + + align:start position:0% +it's almost out of phase so the even +more delay okay so that's the idea so + + align:start position:0% +more delay okay so that's the idea so + + + align:start position:0% +more delay okay so that's the idea so +that the what this is supposed to + + align:start position:0% +that the what this is supposed to + + + align:start position:0% +that the what this is supposed to +motivate is why we like to think about + + align:start position:0% +motivate is why we like to think about + + + align:start position:0% +motivate is why we like to think about +systems in terms of frequency response + + align:start position:0% +systems in terms of frequency response + + + align:start position:0% +systems in terms of frequency response +it's a natural way to think of certain + + align:start position:0% +it's a natural way to think of certain + + + align:start position:0% +it's a natural way to think of certain +kinds of systems just like the time + + align:start position:0% +kinds of systems just like the time + + + align:start position:0% +kinds of systems just like the time +response the impulse response the time + + align:start position:0% +response the impulse response the time + + + align:start position:0% +response the impulse response the time +domain thinking convolution was a + + align:start position:0% +domain thinking convolution was a + + + align:start position:0% +domain thinking convolution was a +convenient way to think about some kinds + + align:start position:0% +convenient way to think about some kinds + + + align:start position:0% +convenient way to think about some kinds +of systems the optical system frequency + + align:start position:0% +of systems the optical system frequency + + + align:start position:0% +of systems the optical system frequency +response is a good way to think about + + align:start position:0% +response is a good way to think about + + + align:start position:0% +response is a good way to think about +some kinds of systems here's one the + + align:start position:0% +some kinds of systems here's one the + + + align:start position:0% +some kinds of systems here's one the +reason it's a good way to think about it + + align:start position:0% +reason it's a good way to think about it + + + align:start position:0% +reason it's a good way to think about it +is that this particular system had a big + + align:start position:0% +is that this particular system had a big + + + align:start position:0% +is that this particular system had a big +response at a certain frequency okay now + + align:start position:0% +response at a certain frequency okay now + + + align:start position:0% +response at a certain frequency okay now +for something has nothing to do with + + align:start position:0% +for something has nothing to do with + + + align:start position:0% +for something has nothing to do with +hablo 3 why is the CD there yes + + align:start position:0% +hablo 3 why is the CD there yes + + + align:start position:0% +hablo 3 why is the CD there yes +it keep it so it somewhat stabilizes it + + align:start position:0% +it keep it so it somewhat stabilizes it + + + align:start position:0% +it keep it so it somewhat stabilizes it +that's correct + + align:start position:0% +that's correct + + + align:start position:0% +that's correct +see it better that's true but then I + + align:start position:0% +see it better that's true but then I + + + align:start position:0% +see it better that's true but then I +should have put one up here too so but + + align:start position:0% +should have put one up here too so but + + + align:start position:0% +should have put one up here too so but +of course who knows I make mistakes + + align:start position:0% +of course who knows I make mistakes + + + align:start position:0% +of course who knows I make mistakes +yes damping what's damping so damping + + align:start position:0% +yes damping what's damping so damping + + + align:start position:0% +yes damping what's damping so damping +controls how big the amplitude got at + + align:start position:0% +controls how big the amplitude got at + + + align:start position:0% +controls how big the amplitude got at +the resonance frequency without the CD + + align:start position:0% +the resonance frequency without the CD + + + align:start position:0% +the resonance frequency without the CD +it went crazy right in order to get the + + align:start position:0% +it went crazy right in order to get the + + + align:start position:0% +it went crazy right in order to get the +response to be less than the elongation + + align:start position:0% +response to be less than the elongation + + + align:start position:0% +response to be less than the elongation +of the spring I had to make the + + align:start position:0% +of the spring I had to make the + + + align:start position:0% +of the spring I had to make the +displacements tiny tiny tiny without the + + align:start position:0% +displacements tiny tiny tiny without the + + + align:start position:0% +displacements tiny tiny tiny without the +CD so that CD was putting some damping + + align:start position:0% +CD so that CD was putting some damping + + + align:start position:0% +CD so that CD was putting some damping +at air resistance okay loss so in + + align:start position:0% +at air resistance okay loss so in + + + align:start position:0% +at air resistance okay loss so in +physics terms the mass and the spring + + align:start position:0% +physics terms the mass and the spring + + + align:start position:0% +physics terms the mass and the spring +are lossless no energy goes away I'm + + align:start position:0% +are lossless no energy goes away I'm + + + align:start position:0% +are lossless no energy goes away I'm +continuously pumping energy into it from + + align:start position:0% +continuously pumping energy into it from + + + align:start position:0% +continuously pumping energy into it from +the motor the response gets bigger and + + align:start position:0% +the motor the response gets bigger and + + + align:start position:0% +the motor the response gets bigger and +bigger and bigger and bigger with the CD + + align:start position:0% +bigger and bigger and bigger with the CD + + + align:start position:0% +bigger and bigger and bigger with the CD +there's loss because of viscosity lost + + align:start position:0% +there's loss because of viscosity lost + + + align:start position:0% +there's loss because of viscosity lost +to the air and so that means that it + + align:start position:0% +to the air and so that means that it + + + align:start position:0% +to the air and so that means that it +doesn't reach as high a peak as it would + + align:start position:0% +doesn't reach as high a peak as it would + + + align:start position:0% +doesn't reach as high a peak as it would +have otherwise okay okay so now what I + + align:start position:0% +have otherwise okay okay so now what I + + + align:start position:0% +have otherwise okay okay so now what I +want to do is think about having + + align:start position:0% +want to do is think about having + + + align:start position:0% +want to do is think about having +measured it let's think about + + align:start position:0% +measured it let's think about + + + align:start position:0% +measured it let's think about +calculating it let's calculate the + + align:start position:0% +calculating it let's calculate the + + + align:start position:0% +calculating it let's calculate the +frequency response we have a number of + + align:start position:0% +frequency response we have a number of + + + align:start position:0% +frequency response we have a number of +ways we could do it because we have all + + align:start position:0% +ways we could do it because we have all + + + align:start position:0% +ways we could do it because we have all +those boxes we have all the different + + align:start position:0% +those boxes we have all the different + + + align:start position:0% +those boxes we have all the different +methods we thought about for + + align:start position:0% +methods we thought about for + + + align:start position:0% +methods we thought about for +characterizing systems so for example we + + align:start position:0% +characterizing systems so for example we + + + align:start position:0% +characterizing systems so for example we +can figure out the differential equation + + align:start position:0% +can figure out the differential equation + + + align:start position:0% +can figure out the differential equation +for the system and we could solve it + + align:start position:0% +for the system and we could solve it + + + align:start position:0% +for the system and we could solve it +with a particular input because Omega T + + align:start position:0% +with a particular input because Omega T + + + align:start position:0% +with a particular input because Omega T +that's one way to do it another way we + + align:start position:0% +that's one way to do it another way we + + + align:start position:0% +that's one way to do it another way we +can do it is find the impulse to the + + align:start position:0% +can do it is find the impulse to the + + + align:start position:0% +can do it is find the impulse to the +system in the impulse response of the + + align:start position:0% +system in the impulse response of the + + + align:start position:0% +system in the impulse response of the +system and then we could convulsions so + + align:start position:0% +system and then we could convulsions so + + + align:start position:0% +system and then we could convulsions so +rather than doing something we know how + + align:start position:0% +rather than doing something we know how + + + align:start position:0% +rather than doing something we know how +to do what I'll do is something that we + + align:start position:0% +to do what I'll do is something that we + + + align:start position:0% +to do what I'll do is something that we +don't know how to do I'll use a + + align:start position:0% +don't know how to do I'll use a + + + align:start position:0% +don't know how to do I'll use a +different method which has to do with + + align:start position:0% +different method which has to do with + + + align:start position:0% +different method which has to do with +eigenfunctions and eigenvalues and we'll + + align:start position:0% +eigenfunctions and eigenvalues and we'll + + + align:start position:0% +eigenfunctions and eigenvalues and we'll +see why that's a convenient way of + + align:start position:0% +see why that's a convenient way of + + + align:start position:0% +see why that's a convenient way of +thinking about frequency response in + + align:start position:0% +thinking about frequency response in + + + align:start position:0% +thinking about frequency response in +just a minute so we'll define an + + align:start position:0% +just a minute so we'll define an + + + align:start position:0% +just a minute so we'll define an +eigenfunction to be sort of the same + + align:start position:0% +eigenfunction to be sort of the same + + + align:start position:0% +eigenfunction to be sort of the same +thing as we do in linear algebra so it's + + align:start position:0% +thing as we do in linear algebra so it's + + + align:start position:0% +thing as we do in linear algebra so it's +it's very much the same concept + + align:start position:0% +it's very much the same concept + + + align:start position:0% +it's very much the same concept +we think about if we have a system and + + align:start position:0% +we think about if we have a system and + + + align:start position:0% +we think about if we have a system and +if we put in an input and the output has + + align:start position:0% +if we put in an input and the output has + + + align:start position:0% +if we put in an input and the output has +the same shape as the input just changed + + align:start position:0% +the same shape as the input just changed + + + align:start position:0% +the same shape as the input just changed +in amplitude then we'll say the input + + align:start position:0% +in amplitude then we'll say the input + + + align:start position:0% +in amplitude then we'll say the input +was an eigenfunction and the change in + + align:start position:0% +was an eigenfunction and the change in + + + align:start position:0% +was an eigenfunction and the change in +amplitude was the eigenvalue so you put + + align:start position:0% +amplitude was the eigenvalue so you put + + + align:start position:0% +amplitude was the eigenvalue so you put +in x of t you get out lambda x of t same + + align:start position:0% +in x of t you get out lambda x of t same + + + align:start position:0% +in x of t you get out lambda x of t same +idea that we have in linear algebra for + + align:start position:0% +idea that we have in linear algebra for + + + align:start position:0% +idea that we have in linear algebra for +eigenvalues okay so that's the idea and + + align:start position:0% +eigenvalues okay so that's the idea and + + + align:start position:0% +eigenvalues okay so that's the idea and +it turns out that certain very common + + align:start position:0% +it turns out that certain very common + + + align:start position:0% +it turns out that certain very common +functions are eigenfunctions of linear + + align:start position:0% +functions are eigenfunctions of linear + + + align:start position:0% +functions are eigenfunctions of linear +time-invariant systems consider this + + align:start position:0% +time-invariant systems consider this + + + align:start position:0% +time-invariant systems consider this +system y dot plus 2y is ax figure out if + + align:start position:0% +system y dot plus 2y is ax figure out if + + + align:start position:0% +system y dot plus 2y is ax figure out if +any of these functions e to the minus c + + align:start position:0% +any of these functions e to the minus c + + + align:start position:0% +any of these functions e to the minus c +e to the t e to the j t cos t or u of t + + align:start position:0% +e to the t e to the j t cos t or u of t + + + align:start position:0% +e to the t e to the j t cos t or u of t +are any of those functions + + align:start position:0% +are any of those functions + + + align:start position:0% +are any of those functions +eigenfunctions of that system and the + + align:start position:0% +eigenfunctions of that system and the + + + align:start position:0% +eigenfunctions of that system and the +answer is yes and so the answer is + + align:start position:0% +answer is yes and so the answer is + + + align:start position:0% +answer is yes and so the answer is +really which ones + + align:start position:0% + + + + align:start position:0% + +so how do I think about is e to the + + align:start position:0% +so how do I think about is e to the + + + align:start position:0% +so how do I think about is e to the +minus T and eigenfunction of that system + + align:start position:0% +minus T and eigenfunction of that system + + + align:start position:0% +minus T and eigenfunction of that system +what should I do + + align:start position:0% + + + + align:start position:0% + +let's take about how many think it is + + align:start position:0% + + + + align:start position:0% + +how many think it isn't okay it must be + + align:start position:0% +how many think it isn't okay it must be + + + align:start position:0% +how many think it isn't okay it must be +right + + align:start position:0% +right + + + align:start position:0% +right +crowdsourcing it has to be true so how + + align:start position:0% +crowdsourcing it has to be true so how + + + align:start position:0% +crowdsourcing it has to be true so how +well how do I think about that well how + + align:start position:0% +well how do I think about that well how + + + align:start position:0% +well how do I think about that well how +could I set that up to convince somebody + + align:start position:0% +could I set that up to convince somebody + + + align:start position:0% +could I set that up to convince somebody +else that it is or is not an + + align:start position:0% +else that it is or is not an + + + align:start position:0% +else that it is or is not an +eigenfunction what would I do + + align:start position:0% +eigenfunction what would I do + + + align:start position:0% +eigenfunction what would I do +yes + + align:start position:0% + + + + align:start position:0% + +close so what what should I make xb + + align:start position:0% + + + + align:start position:0% + +exactly so then Y dot would be so now if + + align:start position:0% +exactly so then Y dot would be so now if + + + align:start position:0% +exactly so then Y dot would be so now if +I plug that in I get Y dot minus lambda + + align:start position:0% +I plug that in I get Y dot minus lambda + + + align:start position:0% +I plug that in I get Y dot minus lambda +e to the minus lambda e to the minus t + + align:start position:0% +e to the minus lambda e to the minus t + + + align:start position:0% +e to the minus lambda e to the minus t +plus 2y plus 2 lambda e to the minus T + + align:start position:0% +plus 2y plus 2 lambda e to the minus T + + + align:start position:0% +plus 2y plus 2 lambda e to the minus T +should be e to the minus T is that true + + align:start position:0% +should be e to the minus T is that true + + + align:start position:0% +should be e to the minus T is that true +for any lambda what should lambda be 1 + + align:start position:0% +for any lambda what should lambda be 1 + + + align:start position:0% +for any lambda what should lambda be 1 +so the answer is yes this is true and + + align:start position:0% +so the answer is yes this is true and + + + align:start position:0% +so the answer is yes this is true and +lambda would have to be 1 for that to be + + align:start position:0% +lambda would have to be 1 for that to be + + + align:start position:0% +lambda would have to be 1 for that to be +true how about this guy + + align:start position:0% +true how about this guy + + + align:start position:0% +true how about this guy +same thing lambda comes out the same + + align:start position:0% + + + + align:start position:0% + +what's lambda for the second line + + align:start position:0% +what's lambda for the second line + + + align:start position:0% +what's lambda for the second line +one-third yeah so now we have to use X + + align:start position:0% +one-third yeah so now we have to use X + + + align:start position:0% +one-third yeah so now we have to use X +is e to the T lambda e to the T lambda e + + align:start position:0% +is e to the T lambda e to the T lambda e + + + align:start position:0% +is e to the T lambda e to the T lambda e +to the T they do that right yeah so now + + align:start position:0% +to the T they do that right yeah so now + + + align:start position:0% +to the T they do that right yeah so now +we have lambda plus 2 lambda e to the t + + align:start position:0% +we have lambda plus 2 lambda e to the t + + + align:start position:0% +we have lambda plus 2 lambda e to the t +should be e to the T so lambda is going + + align:start position:0% +should be e to the T so lambda is going + + + align:start position:0% +should be e to the T so lambda is going +to have to be 1/3 this time ok how about + + align:start position:0% +to have to be 1/3 this time ok how about + + + align:start position:0% +to have to be 1/3 this time ok how about +this guy what's lambda its come + + align:start position:0% +this guy what's lambda its come + + + align:start position:0% +this guy what's lambda its come +one over two plus three exactly + + align:start position:0% +one over two plus three exactly + + + align:start position:0% +one over two plus three exactly +everybody see that + + align:start position:0% +everybody see that + + + align:start position:0% +everybody see that +how about cosine yes no I'd like to + + align:start position:0% +how about cosine yes no I'd like to + + + align:start position:0% +how about cosine yes no I'd like to +break the tie so there's a tie the yeses + + align:start position:0% +break the tie so there's a tie the yeses + + + align:start position:0% +break the tie so there's a tie the yeses +and the noes are equal so what do I do + + align:start position:0% +and the noes are equal so what do I do + + + align:start position:0% +and the noes are equal so what do I do +you do the same thing right no + + align:start position:0% +you do the same thing right no + + + align:start position:0% +you do the same thing right no +difference whoops a little too hard so I + + align:start position:0% +difference whoops a little too hard so I + + + align:start position:0% +difference whoops a little too hard so I +want to say that X is coast right + + align:start position:0% +want to say that X is coast right + + + align:start position:0% +want to say that X is coast right +so Y should be lambda cose so y dot + + align:start position:0% +so Y should be lambda cose so y dot + + + align:start position:0% +so Y should be lambda cose so y dot +should be lambda sine - right so then I + + align:start position:0% +should be lambda sine - right so then I + + + align:start position:0% +should be lambda sine - right so then I +need Y dot minus lambda sine T plus + + align:start position:0% +need Y dot minus lambda sine T plus + + + align:start position:0% +need Y dot minus lambda sine T plus +twice this one lambda cosine T should be + + align:start position:0% +twice this one lambda cosine T should be + + + align:start position:0% +twice this one lambda cosine T should be +that one cosine T which Atlanta beat do + + align:start position:0% +that one cosine T which Atlanta beat do + + + align:start position:0% +that one cosine T which Atlanta beat do +you think complex exponential so if + + align:start position:0% +you think complex exponential so if + + + align:start position:0% +you think complex exponential so if +you're willing to somehow think about + + align:start position:0% +you're willing to somehow think about + + + align:start position:0% +you're willing to somehow think about +some something over here is imaginary + + align:start position:0% +some something over here is imaginary + + + align:start position:0% +some something over here is imaginary +maybe you can do that if you think about + + align:start position:0% +maybe you can do that if you think about + + + align:start position:0% +maybe you can do that if you think about +these as purely real functions there's + + align:start position:0% +these as purely real functions there's + + + align:start position:0% +these as purely real functions there's +no real there's no way to take a cosine + + align:start position:0% +no real there's no way to take a cosine + + + align:start position:0% +no real there's no way to take a cosine +and turn it into a sign that's actually + + align:start position:0% +and turn it into a sign that's actually + + + align:start position:0% +and turn it into a sign that's actually +why we like the complex numbers right + + align:start position:0% +why we like the complex numbers right + + + align:start position:0% +why we like the complex numbers right +had we thought about the cosine as the + + align:start position:0% +had we thought about the cosine as the + + + align:start position:0% +had we thought about the cosine as the +sum of these if we had thought about + + align:start position:0% +sum of these if we had thought about + + + align:start position:0% +sum of these if we had thought about +cosine T as e to the j t + e - JT by two + + align:start position:0% +cosine T as e to the j t + e - JT by two + + + align:start position:0% +cosine T as e to the j t + e - JT by two +if we had thought about it that way it + + align:start position:0% +if we had thought about it that way it + + + align:start position:0% +if we had thought about it that way it +would have actually turned out that we + + align:start position:0% +would have actually turned out that we + + + align:start position:0% +would have actually turned out that we +could think about the complex + + align:start position:0% +could think about the complex + + + align:start position:0% +could think about the complex +Exponential's as being eigen functions + + align:start position:0% +Exponential's as being eigen functions + + + align:start position:0% +Exponential's as being eigen functions +but the cosine function itself thought + + align:start position:0% +but the cosine function itself thought + + + align:start position:0% +but the cosine function itself thought +of as a strictly real function there's + + align:start position:0% +of as a strictly real function there's + + + align:start position:0% +of as a strictly real function there's +no way you could choose the constants to + + align:start position:0% +no way you could choose the constants to + + + align:start position:0% +no way you could choose the constants to +get rid of the phase shift that would be + + align:start position:0% +get rid of the phase shift that would be + + + align:start position:0% +get rid of the phase shift that would be +introduced by the sine okay if we call + + align:start position:0% +introduced by the sine okay if we call + + + align:start position:0% +introduced by the sine okay if we call +the phase of this zero this is phase + + align:start position:0% +the phase of this zero this is phase + + + align:start position:0% +the phase of this zero this is phase +shifted 90 degrees relative to the hand + + align:start position:0% +shifted 90 degrees relative to the hand + + + align:start position:0% +shifted 90 degrees relative to the hand +and there's no way that I could choose a + + align:start position:0% +and there's no way that I could choose a + + + align:start position:0% +and there's no way that I could choose a +real number lambda to make that come out + + align:start position:0% +real number lambda to make that come out + + + align:start position:0% +real number lambda to make that come out +with zero phase okay how about you of + + align:start position:0% +with zero phase okay how about you of + + + align:start position:0% +with zero phase okay how about you of +team I am functional same thing right I + + align:start position:0% +team I am functional same thing right I + + + align:start position:0% +team I am functional same thing right I +would think of the input is U of T the + + align:start position:0% +would think of the input is U of T the + + + align:start position:0% +would think of the input is U of T the +output is lambda U of T the derivative + + align:start position:0% +output is lambda U of T the derivative + + + align:start position:0% +output is lambda U of T the derivative +of the output if the output is lambda U + + align:start position:0% +of the output if the output is lambda U + + + align:start position:0% +of the output if the output is lambda U +of T what's the derivative lambda Delta + + align:start position:0% +of T what's the derivative lambda Delta + + + align:start position:0% +of T what's the derivative lambda Delta +so I'm left with trying to make a lambda + + align:start position:0% +so I'm left with trying to make a lambda + + + align:start position:0% +so I'm left with trying to make a lambda +and Lux we're trying to make it a u + + align:start position:0% +and Lux we're trying to make it a u + + + align:start position:0% +and Lux we're trying to make it a u +function out of the sum of a delta and a + + align:start position:0% +function out of the sum of a delta and a + + + align:start position:0% +function out of the sum of a delta and a +U and there's no way you can do that so + + align:start position:0% +U and there's no way you can do that so + + + align:start position:0% +U and there's no way you can do that so +the answer is that the first three are + + align:start position:0% +the answer is that the first three are + + + align:start position:0% +the answer is that the first three are +eigenfunctions and the last two are not + + align:start position:0% +eigenfunctions and the last two are not + + + align:start position:0% +eigenfunctions and the last two are not +okay so now what says have to do I mean + + align:start position:0% +okay so now what says have to do I mean + + + align:start position:0% +okay so now what says have to do I mean +I set this all up by thinking about + + align:start position:0% +I set this all up by thinking about + + + align:start position:0% +I set this all up by thinking about +frequency response so what we want to do + + align:start position:0% +frequency response so what we want to do + + + align:start position:0% +frequency response so what we want to do +is make the connection between the two + + align:start position:0% +is make the connection between the two + + + align:start position:0% +is make the connection between the two +the first step in the connection is + + align:start position:0% +the first step in the connection is + + + align:start position:0% +the first step in the connection is +complex exponentials + + align:start position:0% +complex exponentials + + + align:start position:0% +complex exponentials +just like I'm motivated here right so + + align:start position:0% +just like I'm motivated here right so + + + align:start position:0% +just like I'm motivated here right so +the complex exponentials + + align:start position:0% +the complex exponentials + + + align:start position:0% +the complex exponentials +so it turns out that all complex + + align:start position:0% +so it turns out that all complex + + + align:start position:0% +so it turns out that all complex +Exponential's are eigenfunctions to all + + align:start position:0% +Exponential's are eigenfunctions to all + + + align:start position:0% +Exponential's are eigenfunctions to all +linear time-invariant systems that's + + align:start position:0% +linear time-invariant systems that's + + + align:start position:0% +linear time-invariant systems that's +kind of amazing that follows very + + align:start position:0% +kind of amazing that follows very + + + align:start position:0% +kind of amazing that follows very +directly from what we did last lecture + + align:start position:0% +directly from what we did last lecture + + + align:start position:0% +directly from what we did last lecture +if we think about a linear + + align:start position:0% +if we think about a linear + + + align:start position:0% +if we think about a linear +time-invariant system as having an + + align:start position:0% +time-invariant system as having an + + + align:start position:0% +time-invariant system as having an +impulse response then we can find the + + align:start position:0% +impulse response then we can find the + + + align:start position:0% +impulse response then we can find the +response to that to the system with + + align:start position:0% +response to that to the system with + + + align:start position:0% +response to that to the system with +impulse response H of T by convolving H + + align:start position:0% +impulse response H of T by convolving H + + + align:start position:0% +impulse response H of T by convolving H +of T with the input which is complex + + align:start position:0% +of T with the input which is complex + + + align:start position:0% +of T with the input which is complex +exponential so if I say that my input is + + align:start position:0% +exponential so if I say that my input is + + + align:start position:0% +exponential so if I say that my input is +e to the st and that my response is + + align:start position:0% +e to the st and that my response is + + + align:start position:0% +e to the st and that my response is +characterized by the impulse response H + + align:start position:0% +characterized by the impulse response H + + + align:start position:0% +characterized by the impulse response H +of T all I need to do is convulse + + align:start position:0% +of T all I need to do is convulse + + + align:start position:0% +of T all I need to do is convulse +whatever it is with X which is e to the + + align:start position:0% +whatever it is with X which is e to the + + + align:start position:0% +whatever it is with X which is e to the +minus s T you remember that when you + + align:start position:0% +minus s T you remember that when you + + + align:start position:0% +minus s T you remember that when you +convolve you do the funny things with + + align:start position:0% +convolve you do the funny things with + + + align:start position:0% +convolve you do the funny things with +the axes so instead of thinking about + + align:start position:0% +the axes so instead of thinking about + + + align:start position:0% +the axes so instead of thinking about +edst as a function of t i think about as + + align:start position:0% +edst as a function of t i think about as + + + align:start position:0% +edst as a function of t i think about as +a function of t minus tau instead of + + align:start position:0% +a function of t minus tau instead of + + + align:start position:0% +a function of t minus tau instead of +thinking about H of T as a function of T + + align:start position:0% +thinking about H of T as a function of T + + + align:start position:0% +thinking about H of T as a function of T +I think of it as H of tau and I run an + + align:start position:0% +I think of it as H of tau and I run an + + + align:start position:0% +I think of it as H of tau and I run an +integral and because of the special + + align:start position:0% +integral and because of the special + + + align:start position:0% +integral and because of the special +form of the exponential function which + + align:start position:0% +form of the exponential function which + + + align:start position:0% +form of the exponential function which +is no coincidence because of the special + + align:start position:0% +is no coincidence because of the special + + + align:start position:0% +is no coincidence because of the special +form of the exponential function the e + + align:start position:0% +form of the exponential function the e + + + align:start position:0% +form of the exponential function the e +to the St factors out so then I'm left + + align:start position:0% +to the St factors out so then I'm left + + + align:start position:0% +to the St factors out so then I'm left +with something that the integral the + + align:start position:0% +with something that the integral the + + + align:start position:0% +with something that the integral the +function of towels the towels all go + + align:start position:0% +function of towels the towels all go + + + align:start position:0% +function of towels the towels all go +away I'm left with purely a function of + + align:start position:0% +away I'm left with purely a function of + + + align:start position:0% +away I'm left with purely a function of +s and in fact it's extraordinarily + + align:start position:0% +s and in fact it's extraordinarily + + + align:start position:0% +s and in fact it's extraordinarily +friendly if I put in ET the s T into a + + align:start position:0% +friendly if I put in ET the s T into a + + + align:start position:0% +friendly if I put in ET the s T into a +linear time-invariant system + + align:start position:0% +linear time-invariant system + + + align:start position:0% +linear time-invariant system +characterized by H of T then the output + + align:start position:0% +characterized by H of T then the output + + + align:start position:0% +characterized by H of T then the output +has the shape eetu the s T and the + + align:start position:0% +has the shape eetu the s T and the + + + align:start position:0% +has the shape eetu the s T and the +eigenvalue is H of s amazing it's the + + align:start position:0% +eigenvalue is H of s amazing it's the + + + align:start position:0% +eigenvalue is H of s amazing it's the +value of the system function the same + + align:start position:0% +value of the system function the same + + + align:start position:0% +value of the system function the same +thing we've been doing since we - + + align:start position:0% +thing we've been doing since we - + + + align:start position:0% +thing we've been doing since we - +evaluated at the s that is the exponent + + align:start position:0% +evaluated at the s that is the exponent + + + align:start position:0% +evaluated at the s that is the exponent +in the complex exponential of interest + + align:start position:0% +in the complex exponential of interest + + + align:start position:0% +in the complex exponential of interest +in my opinion that's wholly remarkable + + align:start position:0% +in my opinion that's wholly remarkable + + + align:start position:0% +in my opinion that's wholly remarkable +then knowing that we can form sinusoids + + align:start position:0% +then knowing that we can form sinusoids + + + align:start position:0% +then knowing that we can form sinusoids +out of complex Exponential's the + + align:start position:0% +out of complex Exponential's the + + + align:start position:0% +out of complex Exponential's the +problems done all complex Exponential's + + align:start position:0% +problems done all complex Exponential's + + + align:start position:0% +problems done all complex Exponential's +are eigenfunctions of all LTI systems + + align:start position:0% +are eigenfunctions of all LTI systems + + + align:start position:0% +are eigenfunctions of all LTI systems +and I can write I can always write an + + align:start position:0% +and I can write I can always write an + + + align:start position:0% +and I can write I can always write an +eternal sine wave in terms of a complex + + align:start position:0% +eternal sine wave in terms of a complex + + + align:start position:0% +eternal sine wave in terms of a complex +exponential by using Euler's expression + + align:start position:0% +exponential by using Euler's expression + + + align:start position:0% +exponential by using Euler's expression +and so I'm done + + align:start position:0% +and so I'm done + + + align:start position:0% +and so I'm done +furthermore the eigenvalues that I need + + align:start position:0% +furthermore the eigenvalues that I need + + + align:start position:0% +furthermore the eigenvalues that I need +to do this are trivial they're the value + + align:start position:0% +to do this are trivial they're the value + + + align:start position:0% +to do this are trivial they're the value +of the system function that's even + + align:start position:0% +of the system function that's even + + + align:start position:0% +of the system function that's even +easier in the case that the LTI system + + align:start position:0% +easier in the case that the LTI system + + + align:start position:0% +easier in the case that the LTI system +can be written as a system of partial + + align:start position:0% +can be written as a system of partial + + + align:start position:0% +can be written as a system of partial +differential equations with constant + + align:start position:0% +differential equations with constant + + + align:start position:0% +differential equations with constant +coefficients when that is true that is + + align:start position:0% +coefficients when that is true that is + + + align:start position:0% +coefficients when that is true that is +not all that is not true for all LTI + + align:start position:0% +not all that is not true for all LTI + + + align:start position:0% +not all that is not true for all LTI +systems what I've said with the convolve + + align:start position:0% +systems what I've said with the convolve + + + align:start position:0% +systems what I've said with the convolve +part that's true for our LTI systems if + + align:start position:0% +part that's true for our LTI systems if + + + align:start position:0% +part that's true for our LTI systems if +I specialize it to the case that the + + align:start position:0% +I specialize it to the case that the + + + align:start position:0% +I specialize it to the case that the +system can be represented by a linear + + align:start position:0% +system can be represented by a linear + + + align:start position:0% +system can be represented by a linear +differential equation with constant + + align:start position:0% +differential equation with constant + + + align:start position:0% +differential equation with constant +coefficients then the system function is + + align:start position:0% +coefficients then the system function is + + + align:start position:0% +coefficients then the system function is +always a rational polynomial in s it's + + align:start position:0% +always a rational polynomial in s it's + + + align:start position:0% +always a rational polynomial in s it's +always the ratio of two polynomials and + + align:start position:0% +always the ratio of two polynomials and + + + align:start position:0% +always the ratio of two polynomials and +s the reason that's interesting + + align:start position:0% +s the reason that's interesting + + + align:start position:0% +s the reason that's interesting +is that we can factor it the reason + + align:start position:0% +is that we can factor it the reason + + + align:start position:0% +is that we can factor it the reason +that's interesting + + align:start position:0% +that's interesting + + + align:start position:0% +that's interesting +is that each of those factors has a very + + align:start position:0% +is that each of those factors has a very + + + align:start position:0% +is that each of those factors has a very +simple geometric interpretation so what + + align:start position:0% +simple geometric interpretation so what + + + align:start position:0% +simple geometric interpretation so what +is so if I can write represent the LTI + + align:start position:0% +is so if I can write represent the LTI + + + align:start position:0% +is so if I can write represent the LTI +system in terms of a system of linear + + align:start position:0% +system in terms of a system of linear + + + align:start position:0% +system in terms of a system of linear +differential equations with constant + + align:start position:0% +differential equations with constant + + + align:start position:0% +differential equations with constant +coefficients then the transfer then the + + align:start position:0% +coefficients then the transfer then the + + + align:start position:0% +coefficients then the transfer then the +system function has the shape has the + + align:start position:0% +system function has the shape has the + + + align:start position:0% +system function has the shape has the +form of a rational polynomial in s by + + align:start position:0% +form of a rational polynomial in s by + + + align:start position:0% +form of a rational polynomial in s by +fundamental theorem of algebra and by + + align:start position:0% +fundamental theorem of algebra and by + + + align:start position:0% +fundamental theorem of algebra and by +the factor theorem I can factor it makes + + align:start position:0% +the factor theorem I can factor it makes + + + align:start position:0% +the factor theorem I can factor it makes +it look like that and then each of these + + align:start position:0% +it look like that and then each of these + + + align:start position:0% +it look like that and then each of these +terms + + align:start position:0% +terms + + + align:start position:0% +terms +looks like a vector in the S plane + + align:start position:0% + + + + align:start position:0% + +difference between two complex numbers + + align:start position:0% +difference between two complex numbers + + + align:start position:0% +difference between two complex numbers +that's a vector so for example if I + + align:start position:0% +that's a vector so for example if I + + + align:start position:0% +that's a vector so for example if I +wanted to think about here's a system a + + align:start position:0% +wanted to think about here's a system a + + + align:start position:0% +wanted to think about here's a system a +single pole at minus 2 say I want to + + align:start position:0% +single pole at minus 2 say I want to + + + align:start position:0% +single pole at minus 2 say I want to +define the output when the input is e to + + align:start position:0% +define the output when the input is e to + + + align:start position:0% +define the output when the input is e to +the to JT e to the to JT is a complex + + align:start position:0% +the to JT e to the to JT is a complex + + + align:start position:0% +the to JT e to the to JT is a complex +exponential the system is linear and + + align:start position:0% +exponential the system is linear and + + + align:start position:0% +exponential the system is linear and +time-invariant therefore I know that the + + align:start position:0% +time-invariant therefore I know that the + + + align:start position:0% +time-invariant therefore I know that the +complex exponential is an eigenfunction + + align:start position:0% +complex exponential is an eigenfunction + + + align:start position:0% +complex exponential is an eigenfunction +therefore all i need to do is find the + + align:start position:0% +therefore all i need to do is find the + + + align:start position:0% +therefore all i need to do is find the +eigen value the eigen value is the value + + align:start position:0% +eigen value the eigen value is the value + + + align:start position:0% +eigen value the eigen value is the value +of the system function at the s in + + align:start position:0% +of the system function at the s in + + + align:start position:0% +of the system function at the s in +question so all i need to do is look at + + align:start position:0% +question so all i need to do is look at + + + align:start position:0% +question so all i need to do is look at +this diagram and i have the entire + + align:start position:0% +this diagram and i have the entire + + + align:start position:0% +this diagram and i have the entire +picture the system is a single pole at + + align:start position:0% +picture the system is a single pole at + + + align:start position:0% +picture the system is a single pole at +minus 2 that's the x i want to know the + + align:start position:0% +minus 2 that's the x i want to know the + + + align:start position:0% +minus 2 that's the x i want to know the +response when the input is e to the j to + + align:start position:0% +response when the input is e to the j to + + + align:start position:0% +response when the input is e to the j to +t so the s in question is s equals to j + + align:start position:0% +t so the s in question is s equals to j + + + align:start position:0% +t so the s in question is s equals to j +so it's that point right there so all i + + align:start position:0% +so it's that point right there so all i + + + align:start position:0% +so it's that point right there so all i +need to know is the length and direction + + align:start position:0% +need to know is the length and direction + + + align:start position:0% +need to know is the length and direction +of the vector that connects the pole to + + align:start position:0% +of the vector that connects the pole to + + + align:start position:0% +of the vector that connects the pole to +the frequency of interest the length of + + align:start position:0% +the frequency of interest the length of + + + align:start position:0% +the frequency of interest the length of +that vector is 2 root 2 the angle is + + align:start position:0% +that vector is 2 root 2 the angle is + + + align:start position:0% +that vector is 2 root 2 the angle is +plus 45 it's a pole so that + + align:start position:0% +plus 45 it's a pole so that + + + align:start position:0% +plus 45 it's a pole so that +contributions in the denominator so the + + align:start position:0% +contributions in the denominator so the + + + align:start position:0% +contributions in the denominator so the +eigen value is 1 over the length of the + + align:start position:0% +eigen value is 1 over the length of the + + + align:start position:0% +eigen value is 1 over the length of the +vector because it's a pole + + align:start position:0% +vector because it's a pole + + + align:start position:0% +vector because it's a pole +and minus the angle because it's in the + + align:start position:0% +and minus the angle because it's in the + + + align:start position:0% +and minus the angle because it's in the +denominator that clear point is it's + + align:start position:0% +denominator that clear point is it's + + + align:start position:0% +denominator that clear point is it's +really easy to do that's why we do it we + + align:start position:0% +really easy to do that's why we do it we + + + align:start position:0% +really easy to do that's why we do it we +only do things in this class that are + + align:start position:0% +only do things in this class that are + + + align:start position:0% +only do things in this class that are +easy to do and you can then divide and + + align:start position:0% +easy to do and you can then divide and + + + align:start position:0% +easy to do and you can then divide and +conquer if you have a system that's + + align:start position:0% +conquer if you have a system that's + + + align:start position:0% +conquer if you have a system that's +linear time-invariant that can be + + align:start position:0% +linear time-invariant that can be + + + align:start position:0% +linear time-invariant that can be +represented by a system of linear + + align:start position:0% +represented by a system of linear + + + align:start position:0% +represented by a system of linear +differential equations coefficients + + align:start position:0% +differential equations coefficients + + + align:start position:0% +differential equations coefficients +rational polynomial s factor do it for + + align:start position:0% +rational polynomial s factor do it for + + + align:start position:0% +rational polynomial s factor do it for +each factor do the same thing I just did + + align:start position:0% +each factor do the same thing I just did + + + align:start position:0% +each factor do the same thing I just did +for each factor the magnitude of the + + align:start position:0% +for each factor the magnitude of the + + + align:start position:0% +for each factor the magnitude of the +response is the product of magnitudes of + + align:start position:0% +response is the product of magnitudes of + + + align:start position:0% +response is the product of magnitudes of +each of those parts the angle of the + + align:start position:0% +each of those parts the angle of the + + + align:start position:0% +each of those parts the angle of the +response is the sum of the angles at all + + align:start position:0% +response is the sum of the angles at all + + + align:start position:0% +response is the sum of the angles at all +of those parts so the idea is that it's + + align:start position:0% +of those parts so the idea is that it's + + + align:start position:0% +of those parts so the idea is that it's +very simple one last step if I'm + + align:start position:0% +very simple one last step if I'm + + + align:start position:0% +very simple one last step if I'm +interested in eternal sine waves like I + + align:start position:0% +interested in eternal sine waves like I + + + align:start position:0% +interested in eternal sine waves like I +was for the motor example then I'll + + align:start position:0% +was for the motor example then I'll + + + align:start position:0% +was for the motor example then I'll +always be interested according to Euler + + align:start position:0% +always be interested according to Euler + + + align:start position:0% +always be interested according to Euler +in to complex Exponential's so if I if I + + align:start position:0% +in to complex Exponential's so if I if I + + + align:start position:0% +in to complex Exponential's so if I if I +were interested in Costa megawati I + + align:start position:0% +were interested in Costa megawati I + + + align:start position:0% +were interested in Costa megawati I +would be interested in the complex + + align:start position:0% +would be interested in the complex + + + align:start position:0% +would be interested in the complex +exponential e to the J Omega naught T + + align:start position:0% +exponential e to the J Omega naught T + + + align:start position:0% +exponential e to the J Omega naught T +and e to the minus J Omega naught T + + align:start position:0% +and e to the minus J Omega naught T + + + align:start position:0% +and e to the minus J Omega naught T +because I need both of those in order to + + align:start position:0% +because I need both of those in order to + + + align:start position:0% +because I need both of those in order to +sum to get the purely real function cos + + align:start position:0% +sum to get the purely real function cos + + + align:start position:0% +sum to get the purely real function cos +Omega naught T so that means then I can + + align:start position:0% +Omega naught T so that means then I can + + + align:start position:0% +Omega naught T so that means then I can +write the response to this eternal + + align:start position:0% +write the response to this eternal + + + align:start position:0% +write the response to this eternal +cosine wave as simply the sum of the + + align:start position:0% +cosine wave as simply the sum of the + + + align:start position:0% +cosine wave as simply the sum of the +system function evaluated at J Omega + + align:start position:0% +system function evaluated at J Omega + + + align:start position:0% +system function evaluated at J Omega +naught times e to the J Omega naught T + + align:start position:0% +naught times e to the J Omega naught T + + + align:start position:0% +naught times e to the J Omega naught T +and the system of function evaluated at + + align:start position:0% +and the system of function evaluated at + + + align:start position:0% +and the system of function evaluated at +s equals minus J Omega naught times e to + + align:start position:0% +s equals minus J Omega naught times e to + + + align:start position:0% +s equals minus J Omega naught times e to +the minus J hang on T done I have the + + align:start position:0% +the minus J hang on T done I have the + + + align:start position:0% +the minus J hang on T done I have the +answer it's even easier because the + + align:start position:0% +answer it's even easier because the + + + align:start position:0% +answer it's even easier because the +system function has a symmetry that we + + align:start position:0% +system function has a symmetry that we + + + align:start position:0% +system function has a symmetry that we +call conjugate symmetry that's easy to + + align:start position:0% +call conjugate symmetry that's easy to + + + align:start position:0% +call conjugate symmetry that's easy to +show + + align:start position:0% +show + + + align:start position:0% +show +also by convolution that's why we did + + align:start position:0% +also by convolution that's why we did + + + align:start position:0% +also by convolution that's why we did +convolution before we did frequency + + align:start position:0% +convolution before we did frequency + + + align:start position:0% +convolution before we did frequency +response + + align:start position:0% +response + + + align:start position:0% +response +you can prove the properties of a + + align:start position:0% +you can prove the properties of a + + + align:start position:0% +you can prove the properties of a +frequency response by resorting back to + + align:start position:0% +frequency response by resorting back to + + + align:start position:0% +frequency response by resorting back to +convolution convolution is a very + + align:start position:0% +convolution convolution is a very + + + align:start position:0% +convolution convolution is a very +powerful thought tool less powerful is a + + align:start position:0% +powerful thought tool less powerful is a + + + align:start position:0% +powerful thought tool less powerful is a +computational tool very powerful thought + + align:start position:0% +computational tool very powerful thought + + + align:start position:0% +computational tool very powerful thought +tool so here again if we think about the + + align:start position:0% +tool so here again if we think about the + + + align:start position:0% +tool so here again if we think about the +system function is the Laplace transform + + align:start position:0% +system function is the Laplace transform + + + align:start position:0% +system function is the Laplace transform +of H of T you remember that from two + + align:start position:0% +of H of T you remember that from two + + + align:start position:0% +of H of T you remember that from two +lectures ago system function is always + + align:start position:0% +lectures ago system function is always + + + align:start position:0% +lectures ago system function is always +the Laplace transform of H of T if I + + align:start position:0% +the Laplace transform of H of T if I + + + align:start position:0% +the Laplace transform of H of T if I +have a physical system like the mass + + align:start position:0% +have a physical system like the mass + + + align:start position:0% +have a physical system like the mass +spring dashpot H of T is real how could + + align:start position:0% +spring dashpot H of T is real how could + + + align:start position:0% +spring dashpot H of T is real how could +it be complex H of T is the response + + align:start position:0% +it be complex H of T is the response + + + align:start position:0% +it be complex H of T is the response +when I have a particular input the + + align:start position:0% +when I have a particular input the + + + align:start position:0% +when I have a particular input the +response of a real system is real so if + + align:start position:0% +response of a real system is real so if + + + align:start position:0% +response of a real system is real so if +I have a system that is real then H of T + + align:start position:0% +I have a system that is real then H of T + + + align:start position:0% +I have a system that is real then H of T +is real if I'm interested in frequencies + + align:start position:0% +is real if I'm interested in frequencies + + + align:start position:0% +is real if I'm interested in frequencies +that are the negative of each other plus + + align:start position:0% +that are the negative of each other plus + + + align:start position:0% +that are the negative of each other plus +a minus J Omega naught in order to form + + align:start position:0% +a minus J Omega naught in order to form + + + align:start position:0% +a minus J Omega naught in order to form +cos Omega naught T then I'm interested + + align:start position:0% +cos Omega naught T then I'm interested + + + align:start position:0% +cos Omega naught T then I'm interested +in two different system functions H of J + + align:start position:0% +in two different system functions H of J + + + align:start position:0% +in two different system functions H of J +Omega and H of minus J Omega which + + align:start position:0% +Omega and H of minus J Omega which + + + align:start position:0% +Omega and H of minus J Omega which +happen to be complex conjugates of each + + align:start position:0% +happen to be complex conjugates of each + + + align:start position:0% +happen to be complex conjugates of each +other since H of T is real I just argued + + align:start position:0% +other since H of T is real I just argued + + + align:start position:0% +other since H of T is real I just argued +that for a physical system H of T has to + + align:start position:0% +that for a physical system H of T has to + + + align:start position:0% +that for a physical system H of T has to +be real if H of T is real then the only + + align:start position:0% +be real if H of T is real then the only + + + align:start position:0% +be real if H of T is real then the only +J in this equation is that one it's + + align:start position:0% +J in this equation is that one it's + + + align:start position:0% +J in this equation is that one it's +negative here so therefore negating J is + + align:start position:0% +negative here so therefore negating J is + + + align:start position:0% +negative here so therefore negating J is +the same as taking the complex conjugate + + align:start position:0% +the same as taking the complex conjugate + + + align:start position:0% +the same as taking the complex conjugate +so I don't really have to compute two + + align:start position:0% +so I don't really have to compute two + + + align:start position:0% +so I don't really have to compute two +different system functions two different + + align:start position:0% +different system functions two different + + + align:start position:0% +different system functions two different +eigenvalues one is the complex conjugate + + align:start position:0% +eigenvalues one is the complex conjugate + + + align:start position:0% +eigenvalues one is the complex conjugate +of the other that means that the + + align:start position:0% +of the other that means that the + + + align:start position:0% +of the other that means that the +response to the sum simplifies so if I + + align:start position:0% +response to the sum simplifies so if I + + + align:start position:0% +response to the sum simplifies so if I +want to think about the input before if + + align:start position:0% +want to think about the input before if + + + align:start position:0% +want to think about the input before if +I want to think about the input is an + + align:start position:0% +I want to think about the input is an + + + align:start position:0% +I want to think about the input is an +eternal cosine wave cos Omega naught T + + align:start position:0% +eternal cosine wave cos Omega naught T + + + align:start position:0% +eternal cosine wave cos Omega naught T +for all time I write that by Euler this + + align:start position:0% +for all time I write that by Euler this + + + align:start position:0% +for all time I write that by Euler this +way I know from this eigen value eigen + + align:start position:0% +way I know from this eigen value eigen + + + align:start position:0% +way I know from this eigen value eigen +function idea that the response to this + + align:start position:0% +function idea that the response to this + + + align:start position:0% +function idea that the response to this +guy can be written this way it's a + + align:start position:0% +guy can be written this way it's a + + + align:start position:0% +guy can be written this way it's a +complex exponential + + align:start position:0% +complex exponential + + + align:start position:0% +complex exponential +complex exponentials or eigenfunctions + + align:start position:0% +complex exponentials or eigenfunctions + + + align:start position:0% +complex exponentials or eigenfunctions +of LTI systems so it has the same shape + + align:start position:0% +of LTI systems so it has the same shape + + + align:start position:0% +of LTI systems so it has the same shape +and an eigenfunction and an eigenvalue + + align:start position:0% +and an eigenfunction and an eigenvalue + + + align:start position:0% +and an eigenfunction and an eigenvalue +sorry this one can be written similarly + + align:start position:0% +sorry this one can be written similarly + + + align:start position:0% +sorry this one can be written similarly +except there's a minus sign but because + + align:start position:0% +except there's a minus sign but because + + + align:start position:0% +except there's a minus sign but because +this is the complex conjugate of this + + align:start position:0% +this is the complex conjugate of this + + + align:start position:0% +this is the complex conjugate of this +and this is the complex conjugate of + + align:start position:0% +and this is the complex conjugate of + + + align:start position:0% +and this is the complex conjugate of +that I've got the sum of a number and + + align:start position:0% +that I've got the sum of a number and + + + align:start position:0% +that I've got the sum of a number and +it's complex conjugate the sum of a + + align:start position:0% +it's complex conjugate the sum of a + + + align:start position:0% +it's complex conjugate the sum of a +number in this complex conjugate is just + + align:start position:0% +number in this complex conjugate is just + + + align:start position:0% +number in this complex conjugate is just +the real part of that number then this H + + align:start position:0% +the real part of that number then this H + + + align:start position:0% +the real part of that number then this H +this eigenvalue the system function + + align:start position:0% +this eigenvalue the system function + + + align:start position:0% +this eigenvalue the system function +evaluated at J Omega naught has a + + align:start position:0% +evaluated at J Omega naught has a + + + align:start position:0% +evaluated at J Omega naught has a +magnitude and an angle if I write the + + align:start position:0% +magnitude and an angle if I write the + + + align:start position:0% +magnitude and an angle if I write the +system function in terms of its + + align:start position:0% +system function in terms of its + + + align:start position:0% +system function in terms of its +magnitude and angle I can factor the + + align:start position:0% +magnitude and angle I can factor the + + + align:start position:0% +magnitude and angle I can factor the +magnitude out of the real part and + + align:start position:0% +magnitude out of the real part and + + + align:start position:0% +magnitude out of the real part and +combine the angle by Euler with the the + + align:start position:0% +combine the angle by Euler with the the + + + align:start position:0% +combine the angle by Euler with the the +angle that generates the cosine wave J + + align:start position:0% +angle that generates the cosine wave J + + + align:start position:0% +angle that generates the cosine wave J +Omega naught T and I'm left with my + + align:start position:0% +Omega naught T and I'm left with my + + + align:start position:0% +Omega naught T and I'm left with my +final answer that you can compute the + + align:start position:0% +final answer that you can compute the + + + align:start position:0% +final answer that you can compute the +output as the magnitude of a system + + align:start position:0% +output as the magnitude of a system + + + align:start position:0% +output as the magnitude of a system +function evaluated at J Omega naught + + align:start position:0% +function evaluated at J Omega naught + + + align:start position:0% +function evaluated at J Omega naught +with a phase shift on the cosine that's + + align:start position:0% +with a phase shift on the cosine that's + + + align:start position:0% +with a phase shift on the cosine that's +equal to the angle of H of jayanna J + + align:start position:0% +equal to the angle of H of jayanna J + + + align:start position:0% +equal to the angle of H of jayanna J +Omega naught so the this is the final + + align:start position:0% +Omega naught so the this is the final + + + align:start position:0% +Omega naught so the this is the final +answer if I want to think about the + + align:start position:0% +answer if I want to think about the + + + align:start position:0% +answer if I want to think about the +frequency response if I want to think + + align:start position:0% +frequency response if I want to think + + + align:start position:0% +frequency response if I want to think +about how this system has a response + + align:start position:0% +about how this system has a response + + + align:start position:0% +about how this system has a response +that depends on frequency I think about + + align:start position:0% +that depends on frequency I think about + + + align:start position:0% +that depends on frequency I think about +the coast Omega T going in and what + + align:start position:0% +the coast Omega T going in and what + + + align:start position:0% +the coast Omega T going in and what +comes out is also cos Omega T cos Omega + + align:start position:0% +comes out is also cos Omega T cos Omega + + + align:start position:0% +comes out is also cos Omega T cos Omega +T except the magnitude is change by the + + align:start position:0% +T except the magnitude is change by the + + + align:start position:0% +T except the magnitude is change by the +magnitude of the system function and the + + align:start position:0% +magnitude of the system function and the + + + align:start position:0% +magnitude of the system function and the +phase is changed by the phase of the + + align:start position:0% +phase is changed by the phase of the + + + align:start position:0% +phase is changed by the phase of the +system function that's this thing I said + + align:start position:0% +system function that's this thing I said + + + align:start position:0% +system function that's this thing I said +back on slide to sign in sign out + + align:start position:0% +back on slide to sign in sign out + + + align:start position:0% +back on slide to sign in sign out +however the magnitude can possibly + + align:start position:0% +however the magnitude can possibly + + + align:start position:0% +however the magnitude can possibly +change and the angle the phase can + + align:start position:0% +change and the angle the phase can + + + align:start position:0% +change and the angle the phase can +possibly change but the frequency cannot + + align:start position:0% +possibly change but the frequency cannot + + + align:start position:0% +possibly change but the frequency cannot +change Omega nought when Omega when in + + align:start position:0% +change Omega nought when Omega when in + + + align:start position:0% +change Omega nought when Omega when in +omega comes out okay so that leads to a + + align:start position:0% +omega comes out okay so that leads to a + + + align:start position:0% +omega comes out okay so that leads to a +very easy way of thinking about + + align:start position:0% +very easy way of thinking about + + + align:start position:0% +very easy way of thinking about +frequency responses + + align:start position:0% +frequency responses + + + align:start position:0% +frequency responses +in terms of pole 0 diagram the idea is + + align:start position:0% +in terms of pole 0 diagram the idea is + + + align:start position:0% +in terms of pole 0 diagram the idea is +if you think about the pole 0 diagram if + + align:start position:0% +if you think about the pole 0 diagram if + + + align:start position:0% +if you think about the pole 0 diagram if +the system can be represented by a + + align:start position:0% +the system can be represented by a + + + align:start position:0% +the system can be represented by a +linear differential equation with + + align:start position:0% +linear differential equation with + + + align:start position:0% +linear differential equation with +constant coefficients then the system + + align:start position:0% +constant coefficients then the system + + + align:start position:0% +constant coefficients then the system +can be represented by a collection of + + align:start position:0% +can be represented by a collection of + + + align:start position:0% +can be represented by a collection of +poles and zeros the handful of numbers + + align:start position:0% +poles and zeros the handful of numbers + + + align:start position:0% +poles and zeros the handful of numbers +how many poles are there how many zeros + + align:start position:0% +how many poles are there how many zeros + + + align:start position:0% +how many poles are there how many zeros +are there and where are they so if I + + align:start position:0% +are there and where are they so if I + + + align:start position:0% +are there and where are they so if I +have that representation + + align:start position:0% +have that representation + + + align:start position:0% +have that representation +how many poles are there how many zeros + + align:start position:0% +how many poles are there how many zeros + + + align:start position:0% +how many poles are there how many zeros +are there where are they I can think + + align:start position:0% +are there where are they I can think + + + align:start position:0% +are there where are they I can think +about the frequency response just by + + align:start position:0% +about the frequency response just by + + + align:start position:0% +about the frequency response just by +thinking about the vector that connects + + align:start position:0% +thinking about the vector that connects + + + align:start position:0% +thinking about the vector that connects +each pole and each 0 in turn from the + + align:start position:0% +each pole and each 0 in turn from the + + + align:start position:0% +each pole and each 0 in turn from the +pole and 0 location to the point on the + + align:start position:0% +pole and 0 location to the point on the + + + align:start position:0% +pole and 0 location to the point on the +J Omega axis at the frequency of + + align:start position:0% +J Omega axis at the frequency of + + + align:start position:0% +J Omega axis at the frequency of +interest so if I have a system that has + + align:start position:0% +interest so if I have a system that has + + + align:start position:0% +interest so if I have a system that has +a single 0 here I have a 0 at Z 1 at s + + align:start position:0% +a single 0 here I have a 0 at Z 1 at s + + + align:start position:0% +a single 0 here I have a 0 at Z 1 at s +equals Z 1 let's say that the zero is at + + align:start position:0% +equals Z 1 let's say that the zero is at + + + align:start position:0% +equals Z 1 let's say that the zero is at +the point Z 1 equals -2 single 0 at the + + align:start position:0% +the point Z 1 equals -2 single 0 at the + + + align:start position:0% +the point Z 1 equals -2 single 0 at the +point s equals -2 then I only need to + + align:start position:0% +point s equals -2 then I only need to + + + align:start position:0% +point s equals -2 then I only need to +think about one vector if I'm interested + + align:start position:0% +think about one vector if I'm interested + + + align:start position:0% +think about one vector if I'm interested +in the response for very low frequencies + + align:start position:0% +in the response for very low frequencies + + + align:start position:0% +in the response for very low frequencies +very low frequencies are at Omega equals + + align:start position:0% +very low frequencies are at Omega equals + + + align:start position:0% +very low frequencies are at Omega equals +0 I only need to think about the vector + + align:start position:0% +0 I only need to think about the vector + + + align:start position:0% +0 I only need to think about the vector +that connects the 0 to the point J Omega + + align:start position:0% +that connects the 0 to the point J Omega + + + align:start position:0% +that connects the 0 to the point J Omega +equals 0 so J 0 which is same as a 0 so + + align:start position:0% +equals 0 so J 0 which is same as a 0 so + + + align:start position:0% +equals 0 so J 0 which is same as a 0 so +the eigenvalue is the length of this + + align:start position:0% +the eigenvalue is the length of this + + + align:start position:0% +the eigenvalue is the length of this +vector that's the magnitude and the + + align:start position:0% +vector that's the magnitude and the + + + align:start position:0% +vector that's the magnitude and the +angle of this vector we always measure + + align:start position:0% +angle of this vector we always measure + + + align:start position:0% +angle of this vector we always measure +angle relative to the x axis so the + + align:start position:0% +angle relative to the x axis so the + + + align:start position:0% +angle relative to the x axis so the +angle of this vector is 0 so I get a + + align:start position:0% +angle of this vector is 0 so I get a + + + align:start position:0% +angle of this vector is 0 so I get a +magnitude which is that big and an angle + + align:start position:0% +magnitude which is that big and an angle + + + align:start position:0% +magnitude which is that big and an angle +which is 0 and that's plotted over here + + align:start position:0% +which is 0 and that's plotted over here + + + align:start position:0% +which is 0 and that's plotted over here +that's my result for a low frequency a + + align:start position:0% +that's my result for a low frequency a + + + align:start position:0% +that's my result for a low frequency a +frequency close to zero then if I think + + align:start position:0% +frequency close to zero then if I think + + + align:start position:0% +frequency close to zero then if I think +about a slightly higher frequency what + + align:start position:0% +about a slightly higher frequency what + + + align:start position:0% +about a slightly higher frequency what +happens to the magnitude of the 0 bigger + + align:start position:0% +happens to the magnitude of the 0 bigger + + + align:start position:0% +happens to the magnitude of the 0 bigger +bigger it's the magnitude of a 0 the 0 0 + + align:start position:0% +bigger it's the magnitude of a 0 the 0 0 + + + align:start position:0% +bigger it's the magnitude of a 0 the 0 0 +the top bigger is bigger so the bigger + + align:start position:0% +the top bigger is bigger so the bigger + + + align:start position:0% +the top bigger is bigger so the bigger +arrow translates to a slightly bigger + + align:start position:0% +arrow translates to a slightly bigger + + + align:start position:0% +arrow translates to a slightly bigger +magnitude the angle that's made with the + + align:start position:0% +magnitude the angle that's made with the + + + align:start position:0% +magnitude the angle that's made with the +x-axis is now slightly positive so + + align:start position:0% +x-axis is now slightly positive so + + + align:start position:0% +x-axis is now slightly positive so +that's illustrated by the fact that the + + align:start position:0% +that's illustrated by the fact that the + + + align:start position:0% +that's illustrated by the fact that the +angle is deviating from zero and in + + align:start position:0% +angle is deviating from zero and in + + + align:start position:0% +angle is deviating from zero and in +general I can think about the frequency + + align:start position:0% +general I can think about the frequency + + + align:start position:0% +general I can think about the frequency +response is just how the length of this + + align:start position:0% +response is just how the length of this + + + align:start position:0% +response is just how the length of this +vector changes as I change Omega the + + align:start position:0% +vector changes as I change Omega the + + + align:start position:0% +vector changes as I change Omega the +change in length tells me the magnitude + + align:start position:0% +change in length tells me the magnitude + + + align:start position:0% +change in length tells me the magnitude +the change in angle tells me the phase + + align:start position:0% + + + + align:start position:0% + +same thing happens if I do minus Omega + + align:start position:0% +same thing happens if I do minus Omega + + + align:start position:0% +same thing happens if I do minus Omega +what on earth is minus Omega so Omega + + align:start position:0% +what on earth is minus Omega so Omega + + + align:start position:0% +what on earth is minus Omega so Omega +was cos Omega T oh my god right it had + + align:start position:0% +was cos Omega T oh my god right it had + + + align:start position:0% +was cos Omega T oh my god right it had +to do with how fast the murderer was + + align:start position:0% +to do with how fast the murderer was + + + align:start position:0% +to do with how fast the murderer was +going what's minus Omega why am i + + align:start position:0% +going what's minus Omega why am i + + + align:start position:0% +going what's minus Omega why am i +drawing minus Omega here yes why am i + + align:start position:0% +drawing minus Omega here yes why am i + + + align:start position:0% +drawing minus Omega here yes why am i +interested in these negative frequencies + + align:start position:0% +interested in these negative frequencies + + + align:start position:0% +interested in these negative frequencies +that don't really exist because I have + + align:start position:0% +that don't really exist because I have + + + align:start position:0% +that don't really exist because I have +an hour to fill and I don't have enough + + align:start position:0% +an hour to fill and I don't have enough + + + align:start position:0% +an hour to fill and I don't have enough +stuff to fill the hour + + align:start position:0% +stuff to fill the hour + + + align:start position:0% +stuff to fill the hour +No why am i interested in negative + + align:start position:0% +No why am i interested in negative + + + align:start position:0% +No why am i interested in negative +frequencies why am i interested in + + align:start position:0% +frequencies why am i interested in + + + align:start position:0% +frequencies why am i interested in +negative frequencies I'm interested in + + align:start position:0% +negative frequencies I'm interested in + + + align:start position:0% +negative frequencies I'm interested in +negative frequencies because they let me + + align:start position:0% +negative frequencies because they let me + + + align:start position:0% +negative frequencies because they let me +create sines and cosines Euler I invent + + align:start position:0% +create sines and cosines Euler I invent + + + align:start position:0% +create sines and cosines Euler I invent +negative frequencies because I like + + align:start position:0% +negative frequencies because I like + + + align:start position:0% +negative frequencies because I like +complex numbers I like complex numbers + + align:start position:0% +complex numbers I like complex numbers + + + align:start position:0% +complex numbers I like complex numbers +because their eigenfunction because the + + align:start position:0% +because their eigenfunction because the + + + align:start position:0% +because their eigenfunction because the +corresponding complex Exponential's are + + align:start position:0% +corresponding complex Exponential's are + + + align:start position:0% +corresponding complex Exponential's are +eigenfunctions COSO mega t was not an + + align:start position:0% +eigenfunctions COSO mega t was not an + + + align:start position:0% +eigenfunctions COSO mega t was not an +eigenfunction i don't like it e to the J + + align:start position:0% +eigenfunction i don't like it e to the J + + + align:start position:0% +eigenfunction i don't like it e to the J +Omega T is an eigenfunction I like it I + + align:start position:0% +Omega T is an eigenfunction I like it I + + + align:start position:0% +Omega T is an eigenfunction I like it I +invent negative frequencies so that I + + align:start position:0% +invent negative frequencies so that I + + + align:start position:0% +invent negative frequencies so that I +can construct coasts out of the sum of + + align:start position:0% +can construct coasts out of the sum of + + + align:start position:0% +can construct coasts out of the sum of +two complex things one of them happens + + align:start position:0% +two complex things one of them happens + + + align:start position:0% +two complex things one of them happens +to be this imaginary frequency thing who + + align:start position:0% +to be this imaginary frequency thing who + + + align:start position:0% +to be this imaginary frequency thing who +cares + + align:start position:0% +cares + + + align:start position:0% +cares +it's just a number it's just math so in + + align:start position:0% +it's just a number it's just math so in + + + align:start position:0% +it's just a number it's just math so in +general we will think about positive and + + align:start position:0% +general we will think about positive and + + + align:start position:0% +general we will think about positive and +negative frequencies negative + + align:start position:0% +negative frequencies negative + + + align:start position:0% +negative frequencies negative +frequencies don't exist + + align:start position:0% +frequencies don't exist + + + align:start position:0% +frequencies don't exist +we simply invent them to make the math + + align:start position:0% +we simply invent them to make the math + + + align:start position:0% +we simply invent them to make the math +easy + + align:start position:0% +easy + + + align:start position:0% +easy +okay so generally speaking because of + + align:start position:0% +okay so generally speaking because of + + + align:start position:0% +okay so generally speaking because of +the complex conjugate symmetry you can + + align:start position:0% +the complex conjugate symmetry you can + + + align:start position:0% +the complex conjugate symmetry you can +predict what the negative frequency part + + align:start position:0% +predict what the negative frequency part + + + align:start position:0% +predict what the negative frequency part +of the system function will look like if + + align:start position:0% +of the system function will look like if + + + align:start position:0% +of the system function will look like if +you know the positive part so generally + + align:start position:0% +you know the positive part so generally + + + align:start position:0% +you know the positive part so generally +speaking we'll only look at the positive + + align:start position:0% +speaking we'll only look at the positive + + + align:start position:0% +speaking we'll only look at the positive +parts when we know this system is real + + align:start position:0% +parts when we know this system is real + + + align:start position:0% +parts when we know this system is real +right this symmetry only comes about + + align:start position:0% +right this symmetry only comes about + + + align:start position:0% +right this symmetry only comes about +when the system was real I proved it + + align:start position:0% +when the system was real I proved it + + + align:start position:0% +when the system was real I proved it +because I knew that H of T was real + + align:start position:0% +because I knew that H of T was real + + + align:start position:0% +because I knew that H of T was real +valued okay so now I can think about the + + align:start position:0% +valued okay so now I can think about the + + + align:start position:0% +valued okay so now I can think about the +same sort of thing that this time with + + align:start position:0% +same sort of thing that this time with + + + align:start position:0% +same sort of thing that this time with +the pole the vector diagram looks the + + align:start position:0% +the pole the vector diagram looks the + + + align:start position:0% +the pole the vector diagram looks the +same the shape of the curves upside down + + align:start position:0% +same the shape of the curves upside down + + + align:start position:0% +same the shape of the curves upside down +because the poles in the bottom longer + + align:start position:0% +because the poles in the bottom longer + + + align:start position:0% +because the poles in the bottom longer +arrows now make smaller eigenvalues so + + align:start position:0% +arrows now make smaller eigenvalues so + + + align:start position:0% +arrows now make smaller eigenvalues so +now as you go to higher frequencies the + + align:start position:0% +now as you go to higher frequencies the + + + align:start position:0% +now as you go to higher frequencies the +idea is that a single pole gives your + + align:start position:0% +idea is that a single pole gives your + + + align:start position:0% +idea is that a single pole gives your +frequency response whose magnitude + + align:start position:0% +frequency response whose magnitude + + + align:start position:0% +frequency response whose magnitude +decays as you deviate from 0 and you get + + align:start position:0% +decays as you deviate from 0 and you get + + + align:start position:0% +decays as you deviate from 0 and you get +increasing phase lag you get increasing + + align:start position:0% +increasing phase lag you get increasing + + + align:start position:0% +increasing phase lag you get increasing +phase lag because this angle increases + + align:start position:0% +phase lag because this angle increases + + + align:start position:0% +phase lag because this angle increases +with omega but it's in the bottom + + align:start position:0% +with omega but it's in the bottom + + + align:start position:0% +with omega but it's in the bottom +increases in the bottom that means it + + align:start position:0% +increases in the bottom that means it + + + align:start position:0% +increases in the bottom that means it +decreases that's why the angle goes down + + align:start position:0% +decreases that's why the angle goes down + + + align:start position:0% +decreases that's why the angle goes down +in this case and if you have a pole and + + align:start position:0% +in this case and if you have a pole and + + + align:start position:0% +in this case and if you have a pole and +a 0 the answer is easily derived from + + align:start position:0% +a 0 the answer is easily derived from + + + align:start position:0% +a 0 the answer is easily derived from +the previous two answers you think about + + align:start position:0% +the previous two answers you think about + + + align:start position:0% +the previous two answers you think about +two vectors one connecting the zero to + + align:start position:0% +two vectors one connecting the zero to + + + align:start position:0% +two vectors one connecting the zero to +the point of the frequency of interest + + align:start position:0% +the point of the frequency of interest + + + align:start position:0% +the point of the frequency of interest +the other connecting the pole and the + + align:start position:0% +the other connecting the pole and the + + + align:start position:0% +the other connecting the pole and the +magnitude is the product of the lengths + + align:start position:0% +magnitude is the product of the lengths + + + align:start position:0% +magnitude is the product of the lengths +of those two vectors and the angle is + + align:start position:0% +of those two vectors and the angle is + + + align:start position:0% +of those two vectors and the angle is +the sum of the angles of those two + + align:start position:0% +the sum of the angles of those two + + + align:start position:0% +the sum of the angles of those two +vectors so you can see that the zero is + + align:start position:0% +vectors so you can see that the zero is + + + align:start position:0% +vectors so you can see that the zero is +slightly shorter at low frequencies and + + align:start position:0% +slightly shorter at low frequencies and + + + align:start position:0% +slightly shorter at low frequencies and +becomes asymptotically the same length + + align:start position:0% +becomes asymptotically the same length + + + align:start position:0% +becomes asymptotically the same length +that means that at high frequencies the + + align:start position:0% +that means that at high frequencies the + + + align:start position:0% +that means that at high frequencies the +magnitude goes to 1 except of course + + align:start position:0% +magnitude goes to 1 except of course + + + align:start position:0% +magnitude goes to 1 except of course +I've got a constant here so it goes to 3 + + align:start position:0% +I've got a constant here so it goes to 3 + + + align:start position:0% +I've got a constant here so it goes to 3 +and at low frequencies this length is + + align:start position:0% +and at low frequencies this length is + + + align:start position:0% +and at low frequencies this length is +shorter than that one so it's slightly + + align:start position:0% +shorter than that one so it's slightly + + + align:start position:0% +shorter than that one so it's slightly +smaller the magnitude is smaller at low + + align:start position:0% +smaller the magnitude is smaller at low + + + align:start position:0% +smaller the magnitude is smaller at low +frequencies similarly for the angles the + + align:start position:0% +frequencies similarly for the angles the + + + align:start position:0% +frequencies similarly for the angles the +both start out as zero so the angle + + align:start position:0% +both start out as zero so the angle + + + align:start position:0% +both start out as zero so the angle +starts out at zero if you go to a high + + align:start position:0% +starts out at zero if you go to a high + + + align:start position:0% +starts out at zero if you go to a high +enough frequency they both both angles + + align:start position:0% +enough frequency they both both angles + + + align:start position:0% +enough frequency they both both angles +go to PI over 2 so they both angled so + + align:start position:0% +go to PI over 2 so they both angled so + + + align:start position:0% +go to PI over 2 so they both angled so +the difference goes to 0 at high + + align:start position:0% +the difference goes to 0 at high + + + align:start position:0% +the difference goes to 0 at high +frequencies as well there's a little + + align:start position:0% +frequencies as well there's a little + + + align:start position:0% +frequencies as well there's a little +blip in the middle because the angle of + + align:start position:0% +blip in the middle because the angle of + + + align:start position:0% +blip in the middle because the angle of +the zero increases more rapidly than the + + align:start position:0% +the zero increases more rapidly than the + + + align:start position:0% +the zero increases more rapidly than the +angle at pole zero is in the top so + + align:start position:0% +angle at pole zero is in the top so + + + align:start position:0% +angle at pole zero is in the top so +there's a little blip for positive phase + + align:start position:0% +there's a little blip for positive phase + + + align:start position:0% +there's a little blip for positive phase +same sort of thing works if I think + + align:start position:0% +same sort of thing works if I think + + + align:start position:0% +same sort of thing works if I think +about the mass spring dashpot system now + + align:start position:0% +about the mass spring dashpot system now + + + align:start position:0% +about the mass spring dashpot system now +if I write the so if I just write the + + align:start position:0% +if I write the so if I just write the + + + align:start position:0% +if I write the so if I just write the +differential equation figure out the + + align:start position:0% +differential equation figure out the + + + align:start position:0% +differential equation figure out the +system function I get a simple form that + + align:start position:0% +system function I get a simple form that + + + align:start position:0% +system function I get a simple form that +looks like so second-order if I imagine + + align:start position:0% +looks like so second-order if I imagine + + + align:start position:0% +looks like so second-order if I imagine +very low damping you can see that the + + align:start position:0% +very low damping you can see that the + + + align:start position:0% +very low damping you can see that the +poles are going to have the form s + + align:start position:0% +poles are going to have the form s + + + align:start position:0% +poles are going to have the form s +squared M plus K must be 0 so they are + + align:start position:0% +squared M plus K must be 0 so they are + + + align:start position:0% +squared M plus K must be 0 so they are +complex ok + + align:start position:0% +complex ok + + + align:start position:0% +complex ok +so if you factor this if you set this + + align:start position:0% +so if you factor this if you set this + + + align:start position:0% +so if you factor this if you set this +equal to 0 you're going to get that s + + align:start position:0% +equal to 0 you're going to get that s + + + align:start position:0% +equal to 0 you're going to get that s +squared M plus K must be 0 if B were + + align:start position:0% +squared M plus K must be 0 if B were + + + align:start position:0% +squared M plus K must be 0 if B were +small so the the poles are going to be + + align:start position:0% +small so the the poles are going to be + + + align:start position:0% +small so the the poles are going to be +complex so for example if the poles were + + align:start position:0% +complex so for example if the poles were + + + align:start position:0% +complex so for example if the poles were +as indicated here about minus 1 plus or + + align:start position:0% +as indicated here about minus 1 plus or + + + align:start position:0% +as indicated here about minus 1 plus or +minus J 3 all you do is the same thing + + align:start position:0% +minus J 3 all you do is the same thing + + + align:start position:0% +minus J 3 all you do is the same thing +we did before + + align:start position:0% +we did before + + + align:start position:0% +we did before +consider the lengths of the vectors + + align:start position:0% +consider the lengths of the vectors + + + align:start position:0% +consider the lengths of the vectors +consider the angle of the vectors here + + align:start position:0% +consider the angle of the vectors here + + + align:start position:0% +consider the angle of the vectors here +you get some product and you get angles + + align:start position:0% +you get some product and you get angles + + + align:start position:0% +you get some product and you get angles +that are complementary so plus and minus + + align:start position:0% +that are complementary so plus and minus + + + align:start position:0% +that are complementary so plus and minus +so the angle starts out at 0 as you + + align:start position:0% +so the angle starts out at 0 as you + + + align:start position:0% +so the angle starts out at 0 as you +increase the frequency one of the pole 1 + + align:start position:0% +increase the frequency one of the pole 1 + + + align:start position:0% +increase the frequency one of the pole 1 +of the arrows gets longer longer by + + align:start position:0% +of the arrows gets longer longer by + + + align:start position:0% +of the arrows gets longer longer by +about a factor of 2 the other gets + + align:start position:0% +about a factor of 2 the other gets + + + align:start position:0% +about a factor of 2 the other gets +shorter gets shorter by a lot more than + + align:start position:0% +shorter gets shorter by a lot more than + + + align:start position:0% +shorter gets shorter by a lot more than +a factor of 2 so that means that the + + align:start position:0% +a factor of 2 so that means that the + + + align:start position:0% +a factor of 2 so that means that the +product of the lengths becomes small but + + align:start position:0% +product of the lengths becomes small but + + + align:start position:0% +product of the lengths becomes small but +they're in the bottom so the eigen value + + align:start position:0% +they're in the bottom so the eigen value + + + align:start position:0% +they're in the bottom so the eigen value +becomes large so that's what's going on + + align:start position:0% +becomes large so that's what's going on + + + align:start position:0% +becomes large so that's what's going on +here + + align:start position:0% +here + + + align:start position:0% +here +ok so that's the idea I've written to + + align:start position:0% +ok so that's the idea I've written to + + + align:start position:0% +ok so that's the idea I've written to +check yourself questions those are + + align:start position:0% +check yourself questions those are + + + align:start position:0% +check yourself questions those are +intended to just be practice with + + align:start position:0% +intended to just be practice with + + + align:start position:0% +intended to just be practice with +complex and + + align:start position:0% +complex and + + + align:start position:0% +complex and +members because you need to know how to + + align:start position:0% +members because you need to know how to + + + align:start position:0% +members because you need to know how to +do complex numbers but the point that so + + align:start position:0% +do complex numbers but the point that so + + + align:start position:0% +do complex numbers but the point that so +the the point of today is just that + + align:start position:0% +the the point of today is just that + + + align:start position:0% +the the point of today is just that +there's a very natural way that's + + align:start position:0% +there's a very natural way that's + + + align:start position:0% +there's a very natural way that's +completely complimentary to thinking + + align:start position:0% +completely complimentary to thinking + + + align:start position:0% +completely complimentary to thinking +about convolution in time there's a + + align:start position:0% +about convolution in time there's a + + + align:start position:0% +about convolution in time there's a +different natural way to think about + + align:start position:0% +different natural way to think about + + + align:start position:0% +different natural way to think about +some systems in terms of the frequency + + align:start position:0% +some systems in terms of the frequency + + + align:start position:0% +some systems in terms of the frequency +response how does the system respond to + + align:start position:0% +response how does the system respond to + + + align:start position:0% +response how does the system respond to +an eternal sine wave it's a very easy + + align:start position:0% +an eternal sine wave it's a very easy + + + align:start position:0% +an eternal sine wave it's a very easy +thing to compute it follows very + + align:start position:0% +thing to compute it follows very + + + align:start position:0% +thing to compute it follows very +naturally from the things that we + + align:start position:0% +naturally from the things that we + + + align:start position:0% +naturally from the things that we +thought about with convolution and the + + align:start position:0% +thought about with convolution and the + + + align:start position:0% +thought about with convolution and the +results quite amazing the result is that + + align:start position:0% +results quite amazing the result is that + + + align:start position:0% +results quite amazing the result is that +the magnitude and angle can be computed + + align:start position:0% +the magnitude and angle can be computed + + + align:start position:0% +the magnitude and angle can be computed +from the Laplace transform of the + + align:start position:0% +from the Laplace transform of the + + + align:start position:0% +from the Laplace transform of the +impulse response which just happens to + + align:start position:0% +impulse response which just happens to + + + align:start position:0% +impulse response which just happens to +be the system function so the point + + align:start position:0% +be the system function so the point + + + align:start position:0% +be the system function so the point +hopefully what you see is we have lots + + align:start position:0% +hopefully what you see is we have lots + + + align:start position:0% +hopefully what you see is we have lots +of representations and now we're seeing + + align:start position:0% +of representations and now we're seeing + + + align:start position:0% +of representations and now we're seeing +even more connections between them okay + + align:start position:0% +even more connections between them okay + + + align:start position:0% +even more connections between them okay +have a good day \ No newline at end of file diff --git a/fSv0tMKLqPw.txt b/fSv0tMKLqPw.txt new file mode 100644 index 0000000000000000000000000000000000000000..f7a14ce6bbc60c1c4d9de83f84906764ef31ece5 --- /dev/null +++ b/fSv0tMKLqPw.txt @@ -0,0 +1,412 @@ +PROFESSOR: OK. + +Let's talk a little bit +about backgrounds again, + +but this time we'll see +how you can digitally + +change the background. + +Now, if you remember +from previous tutorials, + +we discussed collecting +interesting backgrounds + +to use while making the +images, whether you're + +working with the flatbed +scanner or a camera. + +But sometimes we're +in a bit of a rush, + +as I was while making this +initial image of these two + +paper devices. + +At the time, I didn't think +about enhancing the image + +by including an +interesting background, + +maybe to pop out the +devices visually. + +So after I made the image +on the flatbed scanner, + +this is what we got. + +And as we zoom in, +we see a problem. + +A bit of a mess with all +sorts of stuff all over it. + +That's the price I pay +for being in a hurry + +and not cleaning +the glass that day. + +Hint, hint. + +So because of the +presence of all + +of this extraneous +material, we can't simply + +select the background with, +let's say, the Magic Wand, + +and fill in that selected +area with the color. + +The algorithm for +that selection tool + +will not select the dirty spots. + +And the Paint Bucket +won't do it either. + +You see here that the Paint +Bucket filling the background + +will not fill in the +dirty bits either. + +So that's not going to work. + +Let's undo that +with Command-Z. What + +I'm going to wind up doing, if I +want to change this background, + +is to do it in a different way. + +Let me show you how. + +We're going to try. + +OK. + +I'll use the Polygonal Lasso. + +And I'll enlarge this +again and move it over. + +Watch how I select +what is initially + +going to be selecting +just the two devices. + +This will take a bit, +so we can speed up + +the video a little +bit, not to bore + +you too much-- although a little +boredom is good for the soul. + +OK. + +I'm getting there. + +Almost there. + +OK. + +Here we go. + +So what's going on is that I +selected, in fact, actually + +a couple of things. + +If you really think about it, +yes, I selected the devices, + +but if you go to the +inverse of the selection, + +that means it will invert +the selection to everything + +other than the devices, which +means the full background. + +Now that I'm completely +selecting the full background, + +I'm going to fill +it with the color + +that I previously selected. + +It's shown as the +foreground color at 100%. + +And here we go. + +And the background is filled. + +Now I want to show you +a little extra which + +I think is worth thinking about. + +I'm going to once again +go to the selection menu + +and invert the +selection once again, so + +that we are, in fact, back +to selecting the devices. + +I'm going to open up the +Layers window because I'm + +going to show you that we're +working just, at this point, + +with one layer. + +OK. + +Here we go. + +Here's the Layers window. + +So remember, I first +selected this, inverted + +the selection, which +selected the background, + +and inverted it back again +to select the devices, + +so we are back to +selecting the devices. + +I'm now going to make a +layer of these devices + +by copying it-- that's +Command-C-- which has just + +copied the selected +devices, and then Command-B, + +which has pasted +what I just copied, + +creating basically another +layer of just the devices. + +You can't see that +because the copy layer + +is identical to the devices in +the original background image. + +Now what I'm going to do +is something I think is fun + +and I think helpful +to the image. + +I'm going to go to +Layers, then Layer Style. + +Now remember, we're +talking about what + +is labeled here as Layer One. + +I'm going to create a +drop shadow, which I like. + +You can play around with +the various qualities, + +like angle of the +shadow, distance + +of the shadow, the +spread, the size, + +but watch as I change these +particular characteristics. + +What you're seeing +here is a drop shadow. + +OK. + +I'm going to say OK. + +I'm going to zoom +in a little bit + +to show you what +we've done-- created + +the shadow in that layer only. + +I'm going to make this new +layer invisible to show + +you the difference. + +Here is how the background, +the original image, + +looks on its own, and here +it is with the drop shadow. + +So for me this looks +a little bit more + +like the initial image with +its own shadows on the flatbed. + +One more thing. + +I'm going to convert the image +into a more horizontal image. + +Sometimes you want +to add more space, + +either making it more +vertical or horizontal, + +to fit it for a certain format. + +So the color with which we +want to extend the image + +is this color. + +That needs to be in +the background box + +when we increase canvas size. + +OK. + +I'm going to go to the image. + +Canvas Size. + +And here, I think +this might work. + +And if it doesn't, we +can add a little more + +to change the width, +making the image longer. + +Let's just go, let's make it 15. + +So the algorithm will divide +the additional five inches + +on both sides of the +image, keeping in mind + +that the original +image is placed + +in the center of that process. + +And here is the revamped image. + +It gives us a little +more space on both sides. + +So the last thing +I'm going to show you + +is just a little +bit of labeling. + +So I'd like to insert +a label indicating + +that this area from here +to there is a centimeter. + +But before we do that, +we still have two layers. + +So let's flatten the +image, so there, we're + +only working with one layer. + +As you see, there's only +one in the window now. + +I'm going to take our +line, trying it in white. + +You can try in black or +whatever color you want. + +OK, that's not bad. + +Let me undo this. + +That's Command-Z. I want the +lines to be a little closer + +to the area that I'm +connecting it to. + +There's one. + +There's another. + +It's OK. + +We're going to add +some text, which + +I think I'm also going +to make in white. + +And I'm going to label +it, let's say 1cm. + +And then-- that's too small. + +Let's see, it's 18 +using your style. + +Let's go to 24 points +and see how that looks. + +Almost there. + +I'll go back to move +it a little bit. + +That should do it. + +Yeah. + +I like it. \ No newline at end of file diff --git a/gRe7dy2HSTg.txt b/gRe7dy2HSTg.txt new file mode 100644 index 0000000000000000000000000000000000000000..56b935deb3ae34b071a7abc901e8498bc93e2fef --- /dev/null +++ b/gRe7dy2HSTg.txt @@ -0,0 +1,3488 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: OK, good afternoon. + +So in the last couple of weeks, +we've gone through some + +of the major human capacities +that you have and I have and + +most people have most +of them, right? + +Which are the ability to see the +world around us, to attend + +to what's important, to learn +lessons from life, to remember + +things, why we sometimes +forget things. + +And today, we're going to talk +about another huge dimension + +of human experience, of the +human mind, of the human + +brain, language. + +The ability to talk +to one another. + +I can talk, you can listen, +and vice versa. + +To read, to communicate, +in the ways that are so + +remarkable. + +Our life is flooded with +language, right? + +That we hear, that we +read, and so on. + +So when psychologists try to +divide up language and the + +study of both components, they +talk about comprehension, + +understanding what somebody +says to you when you're an + +infant, or now, as an adult, or +reading text, or producing + +speech, which you can do with +your mouth by speaking, or you + +learn to write. + +So you can both comprehend and +produce language, both + +visually and orally. + +And the thing that has greatly +enamored linguists to figure + +out is how language that we +speak is endlessly generative. + +I'm not sure you can actually +calculate out how many + +sentences we could possibly +produce, but just for fun, + +people have done stuff. + +And they said it would take 100 +trillion years to memorize + +all the sentences +we can produce. + +I'm not sure that's +exactly the right + +number, but it's a lot. + +Because we can say a lot of +different sentences and + +understand what a person +is saying. + +It's an incredibly generative +system for communication, one + +person to another. + +So when people in psychology +think about different aspects + +of language, levels of language, +they often divide it + +into something like this. + +Phonology is the sounds of +language that we hear, that we + +acquire as infants, that we use +to speak to one another. + +Syntax, grammar. + +And by this, this isn't school +grammar, not get + +the sentence right. + +It's just the understanding of +the organization of words, and + +how that changes the meaning +of the sentence. + +Syntax. + +Semantics, what do +the words mean? + +What do the groups +of words mean? + +Pragmatics. + +And we'll talk about each +of these a little bit. + +Sometimes a person +is sarcastic. + +So they go, that was an awesome +lecture yesterday in + +psychology. + +Somebody could say that, in +a hundred trillion years. + +And you go, yeah, yeah. + +Right? + +So that's the pragmatics +versus semantics. + +Then, of course, it's +not just sentences. + +We have whole discussions. + +And another aspect of language +we'll just touch on a little + +bit today is emotional +comprehension and production. + +The tone somebody speaks in, the +tone you produce, are also + +informative. + +So there's many aspects +of language. + +We'll start with the most +basic, or phonology. + +So phonemes are the words that +people use to describe the + +building blocks of +speech sounds. + +So boy versus toy are different +by one phoneme. + +Phonemes are the building +blocks of + +the sounds of language. + +Humans use about 100 phonemes +across languages, but any + +given language only +uses a subset. + +And this has really interesting +consequences. + +Of course, a language could only +exist in the world if you + +could understand +those phonemes. + +Phonemes that are +ununderstandable aren't going + +to be a part of anybody's +language. + +But different languages, for +historical reasons, have ended + +up using different subsets +of phonemes. + +And we'll come back to that. + +When we're babies, for about +the first six months of our + +lives, we're universal +learners. + +We know all the phonemes and +respond to all of them. + +As we become native language +speakers and listeners, we + +become only good at the ones +that are used in our language, + +and our ability to even +recognize the ones that are + +not in our language +disappears. + +You can get it back some, but +the older that you are, you + +never get it back fully. + +So we're universal learners at +birth, but we become enslaved + +to the language that we are +native speakers of and listen + +to within months of birth. + +English has about 45. + +So it's more than the number +of letters we have. + +Some people get confused +a little bit + +that letters are phonemes. + +They're not. + +So hot and cold, the oh sound +in hot and the oh sound in + +cold are different sounds, +same letters. + +So there's many more phonemes. + +Even in English, when they say +there's about 45, depending on + +dialects, you could have a +couple more, a couple less. + +So again, we're born +to use all of them. + +Then we use them or lose them. + +It's something, we don't +entirely lose it, but we're + +never as good if we try to learn +a distinction once we + +become older than that. + +Humans understand speech +at an incredible rate. + +The typical fast talking is +about 180 words a minute, 14 + +phonemes a second in a +continuous speech stream. + +But people can go +up to 250 words. + +We're incredibly fast language +processors, incredibly fast + +language processors. + +So how do we roughly +conceptualize, in the most + +simple way, what we have to do +to get to a word that we hear, + +to get to its meaning. + +Well, acoustic information +comes through the ear. + +Those are wave forms, physical +things, arriving at our ears. + +We in some way figure out how +those correspond to phonemes, + +and then map that in some +way to words that have + +meanings in the world. + +And the reason why machines +understanding what you say is + +shockingly hard to do +a good job on is for + +the following reason. + +There's a huge difference +between a word by the time + +your mind understands what it +is and the nature of the + +signal that arrived +at your year. + +So we talked a lot about +that in terms of + +the retina in vision. + +Right? + +You have this very impoverished +stuff that + +arrives in your retina, and then +the whole rest of your + +brain, millions and millions +of neurons and synapses, + +reconstruct what's out there +from a very impoverished + +retinal input. + +And the same thing happens +in audition. + +What gets to your ear is +incredibly impoverished, and + +the rest of your brain has to +brilliantly reconstruct what + +it heard and assign +its meaning. + +And so part of the challenge of +your mind and brain to do + +that is this. + +This is a representation of +something like the physical + +signal that arrives +at your ear. + +And you could say, well, +here's one word. + +Here's another word. + +What's the problem? + +But this is all the signal that +arrives at your ear for + +the word captain. + +So here's the C, all this stuff +for the A, a period of + +long silence that sets +up the P. Turns out-- + +I'll convince you of +this in a moment-- + +that our speech is full within +words of silent breaks that + +are incredibly informative and +alter our perception of what's + +physically going on. + +Then the little T. This +long stuff for the AI. + +This long stuff for the N. + +So the physical signal to your +ear barely resembles what + +seems like a single +unit, captain. + +And where's that pause? + +A person doesn't say, "cap," or +doesn't say "ca," one, two, + +three, "ptain." Right? + +I mean, but the pause is +happening, and it's incredibly + +informative, as I'll show you. + +So that's the incredible +thing. + +Your auditory system, your +language system, has to + +reconstruct sound into +phonemes, into words. + +It's not obvious in the physical +signal of the ear. + +It's not even that the physical +signal at the ear + +gives you much information at +the outset about whether + +you're hearing one word or +two words or three words. + +So here's "what," and "do you +mean" as one big blend. + +Where is "do"? + +Where is "you"? + +Where is "you mean"? + +And why does "what" look so +separate, and these three + +words, "what do you mean," +get all garbled together. + +And you have to unpack them +by your brain and mind. + +Here's another example. + +John said that the dog +snapped at them. + +The dog snapped. + +Here's what's coming, roughly, +to your ear, + +taken from spoken speech. + +And here, again, notice that +the boundaries that you can + +see here, the gaps of silence, +occur not very related to the + +boundaries between the words +that your mind ultimately + +understands. + +So here's the word +"the," "dog". + +Here's S for "snapped". + +Here's a good pause. + +But that's a pause between the +P sound and the T sound. + +That looks like a good +word boundary. + +To a machine, that's a very +good word boundary. + +It's not a word boundary +for you. + +You know snapped is one word. + +And here comes "at." "At" is +kind of blended into the T. So + +there's this physical signal +doesn't even give you breaks + +where words separate +from one another. + +It's kind of a continuous mix +of breaks and silences. + +So here's to convince you that +a silence carries incredible + +information in it. + +Let's see, make sure +I have the volume. + +OK, so I'm going to +play you this. + +This is a physical signal to +your ear of the word "say." + +RECORDING: Say. + +PROFESSOR: OK. + +Yeah? + +I always worry because Tyler's +an expert in this, and I'm + +always like, please, +Tyler, don't + +embarrass me when I'm wrong. + +You don't have this pressure +out there, but the teaching + +assistants are all experts +in something or another. + +And then they know more often +than I do on that topic, and + +we hit their topic +in the course. + +I'm looking over there +nervously. + +So here's "say." Now, they're +going to take this thing and + +just separate this, just in +the way you do a physical + +signal on a computer, just +separate in time. + +They're just going to add +a little bit of time. + +And what do you hear? + +RECORDING: Stay. + +PROFESSOR: The T sound that +makes is simply adding silence + +here to produce that. + +Now, that's what you +hear all the time. + +It's not a random choice. + +But isn't that amazing? + +That silence is as ultimately +informative for your mind as + +actual language sounds +themselves. + +All this is happening on the +order of thousandths of a + +second, in bits of +information. + +That's bad enough. + +Here's another amazingly +tough thing. + +So people like to compare +consonants that have a lot of + +similarities with some +interesting differences. + +Ba and da. + +This is really comparing B +versus D. It's throwing on the + +A just to have a vowel sound. + +So here, again, is a +representation of what's + +coming to your ear. + +Notice that all the difference +between the B and the D, these + +two consonants, all the physical +differences occurring + +in 40,000ths of a second. + +40,000ths of a second is all the +physical difference that + +you get as you hear +these two things. + +RECORDING: Ba. + +Da. + +PROFESSOR: 40,000ths of a +second, and yet you could hear + +the word bad, and you're +not going bad, dab. + +Come on, that was thousandths +of a second, right? + +And not only that, there'd be +another word and another word + +in a sentence. + +That's why people use the word +speech stream, and we like to + +think of it as a +speech torrent. + +Phonemes, phonemes, phonemes, +breaks, all garbled together + +in your mind as you back and +constantly, instantly, and + +brilliantly figure out +what you've heard. + +So let me give you another +example because part of the + +challenge of this are phonemes +occur in the context of words + +and sentences. + +So make sure I have good +volume on this. + +OK, so let's do this +first one. + +RECORDING: [INAUDIBLE]. + +PROFESSOR: What was that? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: What? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: OK. + +Here's the same thing, and a +person is going to say this + +now all by itself. + +RECORDING: Little. + +PROFESSOR: You got +that, right? + +OK. + +RECORDING: Mary saw the three +little pigs in the corridor. + +PROFESSOR: OK, but here's +the amazing thing. + +The first sound you heard, and +I'll replay it, they took the + +word little, and they cut +it out from the last + +sentence you heard. + +When little is said all by +itself, what comes to your ear + +is literally the first +thing you heard. + +Not this, because when you say +a word in isolation, little, + +people say it differently. + +But we almost never +talk like that. + +We almost always have +a sentence. + +And it turns out the way we say +things, and therefore, the + +way you hear things, is hugely +influenced by what comes + +before it and what +comes after it. + +Never mind things like the +speed at which different + +people talk, the accent they +talk, or the loudness of the + +background conversation. + +But just simply the fact +that you're going to + +say little by itself. + +How does that work? + +It's amazing, right? + +Listen again. + +If you heard little all by +itself, and it's exactly the + +same physical signal. + +Maybe it's not so-- + +RECORDING: [INAUDIBLE]. + +PROFESSOR: OK? + +Let me try that again. + +RECORDING: [INAUDIBLE]. + +PROFESSOR: That's exactly the +same physical signal, exactly + +the same physical signal, as-- + +RECORDING: Mary saw the three +little pigs in the corridor. + +PROFESSOR: What you +hear easily as + +little is exactly that. + +Words in isolation-- + +and there's a great +demonstration. + +If you hear a word cut out, the +reason why it sounds like + +nothing is your mind is already +preparing how to + +interpret that, given what you +heard just before it, and also + +a little bit what you +hear just after it. + +Your mind is constantly fixing +up things because it knows + +what's going on, what's going +into it, what's coming out. + +It's not because it just simply +hears the word itself. + +If we lived in a world where +people just say one word every + +half an hour, we +could do this. + +In a world where we're talking +to each other in sentences all + +the time, we have to do this. + +Here's another example of our +brilliant auditory system for + +hearing these kinds of things. + +So again, these are +representations of how this + +physical signal arrives +at your ear. + +Here's the word bet, bee, +boat, and bird. + +They all start with +the same B sound. + +That's easy, right? + +But look what came +to your ear. + +Look at this signal, this +signal, this signal. + +Look at this one. + +How different does this look? + +It's different because what +follows bird influences how + +this is said, but you can see +that you can translate both of + +these into the B sound +pretty easily. + +Now, look at these words. + +These all start with D. Look +at how bet and debt look + +almost identical. + +We said it's only 40 +milliseconds difference, + +40,000ths of a second difference +that physically + +moved through your ear. + +But you can tell the word +bet versus debt. + +Look at the word D, how +different it looks + +from word to word. + +So your mind is constantly +figuring + +out what you're hearing. + +The problem of invariance, and +it's constantly coming to you + +in incredibly variable ways. + +So one of the tools we have, and +an amazing human capacity, + +is what's called categorical +perception. + +So we have all this huge range +of physical sounds that can + +come to our ear. + +And kind of brilliantly, +and you don't + +even think about it-- + +I mean, none of you go around +bragging about your + +categorical perception +abilities, right? + +Like when you go to spring +break, right? + +And maybe some of you will go +home, or you'll see friends, + +and you won't go, I have +categorical perception. + +I try to be modest about it. + +But it's an amazing human +talent, and essential because + +what it does is this. + +We hear this huge range of +sounds, depending on accents, + +what comes before, +what comes after. + +And we have to decide that's a +B. And what you're going to do + +is take this huge range of +things, and just go, boom. + +It's a B or a D, and that's +all there is to it. + +So here's the way they do it. + +So categorical perception. + +Sounds can vary continuously. + +We showed you some of +this continuity. + +In this experiment, on purpose, +they're going to vary + +sounds in a very continuous, +physical way. + +But in our heads, for ba and da +here, in our heads, all the + +stuff that's over here, even +though they're very different + +one from the other at a +physical, specific level, + +we'll say, ba. + +I'm done with it. + +We're going to put it in one +category for interpretation. + +And you're going to have a +pretty sharp boundary here. + +And then everything over here, +all these physical signals, + +you're going to call pa. + +And so you're not going to spend +a lot of time going, + +that was a one third ba, +2/3 pa, probability. + +You couldn't do that, right? + +Because you couldn't +get through a + +word, nevermind a sentence. + +You're going to instantly group +huge numbers of things + +that are different from one +another into two categories + +that need to be separated. + +So here's a kind of experiment +they do. + +I'll just give you the +feeling of it. + +Here's what they're varying, +constant units. + +Constant units, every stimulus +here is different. + +But every time you hear ba, and +they're constantly going + +to vary something by its +physical property, you always + +call it a B. And then something +happens, in about 20 + +milliseconds of information, and +boom, you always call it a + +P. So change, change, change, +change, change, in the + +physical signal, you call +it one category. + +A little bit more +change, boom. + +It's the other category. + +And you keep changing, but for +you, it's always a perfectly + +good P, even though every one +of those are different. + +So it's an amazing fundamental +capacity to take a huge, and, + +for all practical purposes, an +infinite variety of inputs and + +say it's a B or a P if that's +the world I'm working in. + +Syntax. + +That's another way in which we +understand things, the way + +that words are organized +and the order. + +So we could say, "The model +embraced the designer and the + +photographer." Imagine somebody +saying to this. + +But then they complete the +sentence, "The model embraced + +the designer and the +photographer laughed." + +So people who study syntax +really are interested in what + +happens in your mind as you +hear, "The model embraced the + +designer and the photographer," +and some big + +group hug is going on, right? + +And then all of a sudden, you +get this word laughed, and you + +have to rearrange the elements +in your mind. + +That's what syntax is letting +you do, to say, oh, the + +meaning is really +quite different. + +There's only one hug going on, +and one person laughing at + +them, right? + +But the meaning over time as +somebody talks to you set up, + +you're thinking this, boom. + +Because you understand syntax, +you understand what happens. + +Semantics are kind of more +straightforward than how we + +usually think about them. + +They're the meaning of words +or sentences, morphemes. + +And we can understand semantics +even when the + +sentence is nonsense. "Colorless +green ideas sleep + +furiously" is a famous +example. + +We can understand semantics +even in bad grammatical + +sentences, right? + +"Fastly eat dinner, ballgame +start soon." Your fifth grade + +teacher would be up in arms to +hear that, but you understand. + +Eat now. + +Go see the ball game. + +So we get through a lot of +stuff to get semantics. + +And we can see interactions. + +I stole this example from Ted +Gibson because it took me 20 + +minutes to figure out what +the sentence means. + +You're probably faster +than I am. + +Are you OK? + +I'm like the old man. + +Where's the missing words? + +The old man the boats. + +So this is how you have to +parse up the sentence. + +It's not always obvious. + +People who study language love +these things, where people are + +all confused. + +Most of our lives, we don't go +through that much confusion. + +But there's some fun ones, +sort of like the visual + +illusions, to point out how +meaning and syntax can + +interact as you figure +out things. + +Here's another example. + +Jay Leno talked about sex +with Lindsey Lohan. + +OK, now wait a minute. + +Did I miss that excellent +episode of Jay Leno, or was + +she on the show, and talking +about-- she was saying I'd + +rather not talk about my +recent conviction. + +I'd rather talk about something +less controversial. + +So semantic. + +All these things are constantly + +interacting in your mind. + +It's kind of amazing when you +think about that, right? + +We said phonology's amazing. + +Semantics, syntax, boom. + +They're all happening in you. + +And none of you are +sitting there, + +going, just do phonology. + +Please don't ask me +to do semantics. + +We just had midterms, right? + +Brilliant. + +So one of the ways that people +try to convince themselves + +that these things are separable +and gives a little + +bit more insight is Evoked +Response Potentials. + +Those are these things that you +can measure on infants or + +adults that measure electrical +activity in milliseconds and + +the speed of language +processing, surface electrodes + +that give you an index of a few +hundred thousand neurons. + +And this is an example you saw +before, actually, earlier in + +the course, the so-called +N400. + +So N means whether the +wave is going up or + +down, negative or positive. + +400 means that it occurs about +400 milliseconds, about half a + +second, after the +relevant event. + +So here is this, let's see, it +was his first day at work. + +That's the baseline. + +He spread the warm +bread with socks. + +Oh my gosh, socks. + +Semantically bad. + +And here comes the N400. + +And the control condition is you +throw up this unexpected + +word, shoes, that's weird, but +not semantically, and you get + +quite a different response. + +So here's an N400 that seems +to simply be about semantic + +expectation or congruence. + +How about if you +mess up syntax? + +The spoiled child throw +the toys on the box. + +Then you get a response at +about 600 milliseconds to + +syntactic incongruity. + +So people, this is just more +evidence that in the brain, + +meaning or semantics and syntax +or something about word + +order are processed somewhat +differently in time and place. + +Pragmatics is kind of fun. + +It's practical understanding. + +The old joke, do you know +what time it is? + +And the person says, yes. + +They're messing with your +sense of pragmatics. + +Two negatives make a positive. + +Saying, yeah, yeah. + +I've heard that one before, +earlier in the lecture. + +Now, here's something kind of +interesting, again, which is + +remarkable. + +And if you didn't do the +experiment, you couldn't know + +that our mind is like this. + +Because you wouldn't do things +like this because it sounds + +too ridiculous, but your mind +does it all the time. + +So we're going to think about +the word "bugs." And I have to + +set you up a little bit with +paradigms you've heard before, + +but just remind you +of these things. + +So one kind of task that +psychologists like to use to + +think about how people +process words is a + +lexical decision task. + +All you're deciding is whether +a word is a real word or a + +nonsense word. + +So doctor is real. + +Poctor is not. + +Spy is a real word. + +This spelling is not +a real word. + +So real word, not a real word. + +We also talked about one other +idea early in the course, that + +if, prior to processing a word +like doctor, you get an + +unrelated word or a related +word, you process doctor + +faster if you had a related +word before it. + +Semantic priming. + +The ideas about nurse +overlap a lot with + +the ideas about doctor. + +And seeing this word +before makes you + +process this word faster. + +So you need those two +things in mind. + +What was the person doing? + +Is it a real word or not? + +And you're going to mess with +what's in their mind before + +that, related or unrelated. + +And here's the experiment. + +So you would hear, over +headphones, something like + +this, as an example. + +"Rumor has it that for years +the government building had + +been plagued with +problems." Now, + +here's a critical sentence. + +"The man was not surprised when +he found several spiders, + +roaches, and other bugs in +the corner of his room." + +So there's two senses of the +word, at least two meanings of + +the word bug, right? + +The insect you don't want in +your soup, or the microphone + +that somebody slipped into +your room to listen to + +what's going on. + +Two different meanings +for the word bug. + +This is obviously about +the insect. + +So the person is hearing this +over headphones, and on a + +computer monitor in front of +them, after they hear the word + +bugs here, they see, for a +lexical decision, the word + +"ant," which is related to this +meaning, or "spy," which + +is related to the other meaning +that's not relevant + +for here, or "sew," which is +the control condition. + +We'll ignore that because it's +just a control condition. + +I'll ignore that for now. + +So you're making a lexical +decision now on the related + +meaning or the unrelated +meaning. + +And here's what they find. + +If it's the related meaning, and +you only have about a half + +second from when that came on +to when you had to do this + +task, so you saw the word +bug and here comes + +this, you're faster. + +But if you get the unrelated +meaning within a half a second + +of processing the word, +you're also faster. + +What this means is, your mind +has done exactly what you + +would think it wouldn't do. + +Your mind has looked up in +your brain, and in your + +knowledge of vocabulary, every +meaning of the word. + +Even though the sentence is +clearly setting you up for the + +word, the insect meaning, every +meaning of your word is + +turned on and available +to you. + +Your mind does the opposite +of what you might think. + +You might think, well, I know-- + +let's look at the sentence. + +I know, once I get spiders, +roaches, and bugs. + +By here, you know you're in the +insect world, not in the + +world of spies, right? + +But your mind, even then, looks +up every possible word. + +Because it's cheaper for the +mind to look up every word + +than to start to decide what +the appropriate word is. + +And then, if you wait another +second and a half, you're only + +fast for the selected meaning. + +And now you're slowed +down for the one + +that's not context relevant. + +So your mind looks up everything +all the time. + +Every meaning of every +word you know. + +Every time that word pops up, it +seems like your mind looks + +up every meaning, and then the +rest of your mind selects out + +the one that's relevant +and shuts down the + +ones that are not. + +But you wouldn't think that. + +You would think, maybe I'll +just get the one I need. + +I'm not going to +get everything. + +It's like, I'm not going to put +all my clothes on, walk + +outside, and take off everything +that's not relevant + +for the weather, right? + +It seems like a really +inefficient way to get + +dressed, right? + +But that's not the +way your mind is. + +Your mind is cheaper and more +efficient to look up every + +meaning every time, and then +pick the right one. + +It's more efficient, and that's +how people do it. + +So people use this word +exhaustive lexical access. + +I look up every meaning of a +word, and then I'll pick out + +the correct one. + +Another interesting aspect that +could be brought into + +pragmatics, and we'll talk a +little bit more about this + +later in the course, but +emotional intonation. + +And it turns out where it's +almost all language processes + +are left dominance as +we talked about many + +times in the course. + +One stream of processing +language, both visual and + +auditory, is right hemisphere +dependent. + +And that's emotional +intonation. + +And that brings us to +our reading for + +today, from Oliver Sacks. + +And I have to say, I think +Oliver Sacks is a phenomenal + +author, but there's always been +this sense of some of + +these stories are just a bit +too true to be-- just a bit + +cute, or whatever it is. + +And so for years, I taught +from this story, and I + +believed it's likely true. + +But I thought, well, it's +just a little cute. + +And then came an experiment +that showed it's not only + +cute, but it's exactly +correct. + +So for this, you appreciate this +a bit more if you know a + +couple things about Ronald +Reagan, who was + +president in the 1980s. + +So what do you guys know +about Ronald Reagan? + +What party? + +AUDIENCE: Republican. + +PROFESSOR: There you go. + +Was he considered a +good communicator? + +AUDIENCE: Yes. + +PROFESSOR: Yes. + +He was considered-- you know, +you can have all kinds of + +views on Ronald Reagan's +things. + +The public said, he's an +awesome communicator. + +In fact, Barack Obama said he +would like to communicate like + +Ronald Reagan. + +Whether that's to get Republican +votes or not, + +that's your judgment. + +But he was considered an +excellent communicator. + +Was he considered, by and large, +to be an extremely + +analytic thinker? + +He might have been. + +I don't know him. + +But not so much. + +Now, part of this is the +prejudice or not, but he was + +from California, and he was +an actor before he became + +president, or the governor +president. + +He also had some degree of-- + +well, he ultimately got +Alzheimer's disease. + +It's a question about later in +his administration, whether he + +was already working his +way towards that. + +So anyway, complicated things. + +So he was a master communicator, +but not + +necessarily the Barack Obama, +Bill Clinton, Jimmy Carter + +version of an analytic power, +is the general perception. + +You never know whether +these are right or + +wrong for the person. + +But in the story, listening to +the president's speech, are + +patients with aphasia that +Oliver Sacks described, and + +he's getting laughter as they're +watching his speech. + +And what happens is, some of +the people with a left + +hemisphere lesion-- so you +have a language problem. + +We'll see a video of that +pretty shortly. + +They're laughing because they +think that the way he's + +talking and his facial + +expressions, they find hilarious. + +Now, why do they find +it hilarious? + +They have damage to the parts +of the brain that help them + +understand the content of +his message on the left + +hemisphere. + +And here's what Sacks +thinks is going on. + +"The feelings I have, which +all of us who work closely + +with aphasics have, is that you +cannot lie to an aphasic. + +He cannot grasp your words, and +so be deceived by them. + +But what he grasps, he grasps +with infallible precision, + +namely, the expression that +goes with the words, that + +total spontaneous, involuntary +expressiveness which can never + +be simulated or faked, or +words alone can hide all + +sometimes too easily." + +So when you give a very public +speech, especially under tough + +circumstances, that presidents +sometimes have to do, we + +sometimes think there's a +tension between exactly what + +they're saying and exactly +what they're thinking. + +And what they feel they need to +say, and exactly what they + +know is behind the scenes. + +And so the idea is that these +aphasics, they were saying + +this guy obviously doesn't +mean what he's saying. + +Look at his face. + +Look at his tone. + +I don't know what he's saying, +but it's hilarious, how he's + +masking his face and speaking +in a funny tone to tell + +something he truly +doesn't believe. + +That's their interpretation. + +And yet, he has an opposite +patient, a patient with a + +right hemisphere lesion. + +We said that's the side of +the hemisphere that seems + +important for facial expressions +and emotional + +intonation. + +And she complains about the +logic of the case he's making, + +as if having-- + +normally, when we talk to +somebody, it's both. + +Left hemisphere's getting +the content, + +analyzing the content. + +Right hemisphere, something +about the intonation. + +True or not true? + +Are their eyes like this, and +they can't even face us as + +they tell us something +they know is false. + +But these patients, maybe +because they have one channel + +of information knocked out +because of injury, they become + +hypersensitive to +the other one. + +So I thought, well, that +sounds fantastically + +interesting, but is +that really true? + +So here in Boston, they did a +study with a large number of + +patients that says they had +superior identification of + +people who are lying to you-- + +they had made video clips and +audio clips of people who are + +lying to you-- + +if they had a left hemisphere +lesion. + +So this is a paper. + +So here's the two examples. + +So they have an example. + +Let's pick this one. + +Where both, you see +just a facial + +expression of a person talking. + +The voice is turned down. + +Your job is to decide whether +a person is lying or not. + +And some videos they're lying. + +Some videos they're not. + +So how would you do? + +I don't know how you would do, +but I can tell you how a group + +of Harvard undergraduates did. + +50% is chance, and here's +how they did. + +That was one of their +control groups. + +And, in fact, for studies like +this, they brought in many, + +many kinds of people to ask +whether anybody is better. + +Everybody's pretty much terrible +at directly telling + +whether a lie is going on. + +Now, these are video clips of +people you don't know in + +circumstances you don't know. + +That could matter. + +But everybody's terrible +at that. + +Policemen are terrible. + +FBI agents are terrible. + +The only group that seems to be +above chance, and not much + +above it, are Secret +Service agents. + +So if you're friend with a +Secret Service agent, and you + +want to deceive them, keep in +mind that they seem to be + +above chance. + +They're not awesome, but +they're above chance. + +But look who's doing better than +everybody, patients with + +the left hemisphere lesions. + +And the interpretation +is, all the content + +of the lie is gone. + +All they see is your expression, +or your expression + +and intonation. + +And because that's all they have +to go on, they can tell + +more when you have the +discomfort of lying than a + +person who's partly persuaded by +hearing the message you're + +sending as you talk. + +So I thought this was an overly +cute example, but it + +turns out to be exactly +replicable in a full study. + +Any questions about that? + +OK. + +So let's talk a little +bit about the + +brain basis of language. + +We've talked a little +bit about-- + +we know that if you have damage +here, you have Broca's + +aphasia on the left hemisphere, + +trouble producing language. + +Damage here, Wernicke's +aphasia, trouble + +comprehending language. + +To a first approximation, and +there's a lot of research that + +has made this much more +complicated, but a first + +approximation, the lesions +are in frontal + +cortex or temporal cortex. + +The speech in these patients are +what's called non-fluent + +or telegraphic. + +They get single words out but +have a hard time with anything + +like a sentence. + +It can be very frustrating +for these patients. + +Wernicke's patients +seem much happier. + +You'll see a film in a moment. + +Their speech is fluent, +but it's + +amazingly empty of content. + +These patients have trouble +producing speech, but their + +comprehension is decent. + +These patients produce speech +pretty well, but their + +comprehension. + +So they're mirror opposites. + +And let's see, what do I want? + +Yes. + +So in this field, a frequently, +incredibly + +frequently used picture +to study aphasia is + +this specific picture. + +It's called the cookie +theft picture. + +Why it's become widely used, +I'm not exactly sure. + +But once it's widely used, then +often everybody uses it. + +So they'll put a picture like +this in front of an + +individual, and they'll +ask them to describe + +what's going on. + +It's to elicit production. + +And you would say something +like, there's two kids. + +The kid's on a stool. + +Uh oh, is he going +to fall over? + +Because they're falling off +the cookie jar, and the + +mother's sort of not +paying attention. + +Her mind must be somewhere else +because she's letting the + +water splish splash +here, right? + +You would say something +like that. + +So let's see what patients with +aphasia say, and other + +examples of their difficulty +with language. + +Yeah? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Their writing tends +to go pretty much with their + +spoken language. + +That's a really good question +about-- so the question is, + +what would their writing +be like? + +It very much parallels their +spoken language. + +Yeah? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Sorry? + +AUDIENCE: [INAUDIBLE] + +sign language? + +PROFESSOR: OK, so very +good question. + +Could not fluent aphasics learn +sign language to bypass, + +in a sense, their +problem, right? + +So I'm about to answer +that in a moment, + +right on the next slide. + +Not directly that, but the +implication of that. + +Because the important thing is-- +so let me show you this + +thing, and let me come back. + +The question is, could you train +an aphasic to use sign + +language to get around his or +her language problem, if it's + +a speech problem? + +So people have studied sign +language as a language for + +many reasons, but a +huge one is this. + +Because I'm going to interpret +your question the way I need + +to, and then you can tell me +if I did it right from your + +perspective. + +Which is, in what sense does +language equal speech? + +Could you communicate +linguistically like, but just + +switch to your hands, if for +some reason-- and the answer + +is, that at the level of the +problem of these patients, + +they could not do it. + +Because these kinds of patients, +the problem isn't + +really speech. + +There are people who have +problems with the motor + +apparatus to move their mouth. + +That does exist. + +Their problem is in language +processes that produce your + +speech intent, or language +processes that extract meaning + +from sounds. + +And those language processes +that produce what you want to + +say, that comprehend what you +hear or read, those are the + +same ones that are utilized, +as far as we understand, + +whether you're producing +language in the typical, vocal + +way, or in the less +typical, but + +well-studied, way of sign language. + +Does that make sense? + +OK. + +So you can't get around +it because + +it's a language problem. + +So both by brain imaging +evidence, for example, here + +are patients who use sign +language turning on Broca's + +area and Wernicke's area +on tasks that are about + +comprehension and production. + +It's the same areas, whether +it's using your hands for sign + +language or using your mouth to +talk or your ear to hear. + +Further, there have been really +fun studies where they + +took deaf infants and have +shown-- and it's not easy to + +show, but I think most people +are convinced that they babble + +with their hands. + +The same way babies make +little sounds to get + +themselves going. + +We'll talk more about +infants in a moment. + +Infants who grow up in an +environment where they only + +learn sign language babble +with their hands because + +speech, language is not about +your mouth talking. + +It's about ideas that you can +communicate by your production + +or comprehension, by your +hand or by your mouth. + +So language is separable from +speech, because even without + +speech, you communicate in very +much the same way, in + +terms of sign language, +by many studies. + +Yeah? + +AUDIENCE: So does that mean that +people that [INAUDIBLE] + +imagined words or language? + +PROFESSOR: Say that +again, sorry? + +AUDIENCE: Does that mean that +they also couldn't imagine + +words or language? + +PROFESSOR: Who couldn't? + +AUDIENCE: People with Broca's +area aphasia. + +PROFESSOR: I don't think so. + +We talked about this +before, that-- + +I may not be understanding your +question exactly, but-- + +in many ways, imagining +something is the same part of + +the brain that does it. + +When we imagine a face, we +turn on the parts of + +our brain that sees. + +I think when you imagine, +if you-- + +I do this sometimes. + +I say, here's what I'm +going to say to that + +person, in my head. + +And I practice that +little speech. + +That's this part of the brain +pretty much running. + +There's just a last little step +of moving your mouth, but + +from the discussion we're having +now, that's kind of a + +superficial thing of +moving your mouth. + +That's not speech planning, +speech thinking, speech + +intentions. + +Those are our core process for +production, for comprehension, + +and I think imagined stuff +is exactly the same way. + +Is that OK? + +Yeah. + +Yeah? + +AUDIENCE: So if they can't +really imagine language, then + +how do they-- what is +their thinking like? + +[INAUDIBLE]? + +PROFESSOR: Yeah, that's a good-- +so the question is, if + +they have these troubles with +core language ideas, + +abilities, what's their +thinking like? + +I could just tell you, it's a +classic debate for humans, how + +deeply language equals +thought. + +But language [INAUDIBLE] +in a sense of speech. + +It's just one of those things +that people debate a lot + +because it depends what you mean +by these things in many + +different ways. + +But if language means something +like comprehending + +ideas in the world, it's hard +to get around that for + +thinking [INAUDIBLE]. + +It means planning actions in +the world that change the + +world around you, and +communicating that, it's hard + +to not have that capacity for +thinking in that way, right? + +So it's at this level, not +whether you use your hands or + +your mouth, it's very hard to +separate out what you might + +call thought and what you +might call language. + +But keep in mind that these +patients that we see, it's not + +like they lost all of +language at all. + +So even the Broca's aphasic +has trouble producing + +language, he's producing +some, and he + +comprehends it pretty well. + +So it's not like these patients +have lost all of + +their language circuitry, and +therefore don't have thought + +available, right? + +They have a lot of language left +in their head, and a lot + +of thought left in their mind. + +Is that OK? + +So one interesting thing that +people have wondered, and + +where brain imaging gives us +evidence that we couldn't have + +imagined 15 years +ago, is this. + +So if you have damage, let's +say, here's a patient with + +damage to the left +frontal area. + +And they get better because +they've had a stroke here or + +an injury here. + +They get better. + +A question that people have +wondered is, do they get + +better by sort of somehow +recovering ability in a part + +of their brain that +got injured? + +Or do they get better because +they use an entirely different + +pathway in their brain? + +Now, until brain imaging, +you couldn't begin + +to touch that question. + +But now we have some evidence, +and I'll make it just-- + +and so here's an example of a +patient who has damage here. + +They have him do a task that +in healthy people turns on + +exactly that place. + +And when he does it, +he can do it OK. + +And where does he do it? + +In his right hemisphere. + +So this patient seems to switch +which hemisphere he + +uses for language. + +It takes time and training +to recover that. + +But it seems like he's found +an alternate pathway to + +produce a language somehow. + +Turns out that the more people +have studied these things, the + +more complicated it gets. + +Maybe just diversity of people, +diversity of injuries, + +or whatever. + +So it doesn't always +work this way. + +But often, it seems like when +people have better recovery + +from a large injury to the +speaking left hemisphere, they + +find a way, somehow, through +practice and training, to get + +the right hemisphere to take +over some of those + +responsibilities. + +Language acquisition. + +So one of the most amazing +things about infants is they + +go from zero to speech in just +a couple of years, and go + +through an unbelievable training +and program of + +development. + +So what happens? + +In two or three months, they +perceive all the phonemes. + +They notice this change +in phonemes. + +By six months, they start to +ignore distinctions among + +sounds that are not used +in their language. + +In other words, other +language sounds. + +They start to babble, in +some way getting their + +speech ready to go. + +By eight months, they start to +identify single words in a + +speech stream. + +In a year, their babbling +becomes + +more adult-like sounding. + +But a little bit after that, +they get up to about 50 words + +in understanding. + +So comprehension always goes +ahead of production. + +Children understand words before +they can speak them. + +But they're lagging. + +Here comes a speech, telegraphic +speech, short + +sentences at two years. + +And then, finally, pretty +complete speech, in + +many ways, by nine. + +So it's a long, long process, +learning 10,000 words + +estimated by the age of six. + +That's a spectacular +learning curve. + +When they do experiments on +infants where they measure + +things like preference or +learning by sucking rates on a + +nipple because they can't talk, +they try to figure out, + +what is the infant hearing. + +Within two hours of birth, they +suck with more enthusiasm + +to their mother's voice +over another voice. + +These are infants, this +is their first + +visit to their mother. + +You have to sign up to +do this experiment. + +Now, they might have heard +their mother's voice in a + +certain way in the +womb, right? + +But they already have picked +up, by three-day-old, they + +prefer language to many other +sounds, like music. + +We come to love music, but +that's not the urgent business + +of the infant. + +By four days old, they start +to notice the differences + +between languages. + +This is amazing. + +Their rate of learning +is fantastic. + +And by two months, they can tell +the ba-ga distinction, + +subtle distinctions, 40 +milliseconds information. + +And then they develop a +continuingly strong preference + +for the sounds of their +native language. + +Now, some years ago, people +debated endlessly this left + +hemisphere specialization +for language. + +This is fantastically essential + +and striking in humans. + +Does that grow over time, +or is it in your mind + +and brain at birth? + +And the evidence is pretty +compelling for many sources, + +but here is maybe the most. + +Here's fMRI on two-day-old +infants. + +You might ask, how do they +instruct the infants to lie + +still in the scanner and +participate in the experiment? + +And the answer is, at two days +old, infants mostly just lay + +there and don't do much. + +They don't do much. + +And there's a lot going on in +their mind, but they don't + +have much physical apparatus +to do much. + +So you could swaddle them very +warmly, and just lay-- + +you put them on a cradle +into the fMRI scanner. + +Their parents have signed +up for them. + +And you could play them sounds +while they just lay there and + +do nothing. + +They can't push buttons. + +They can't do stuff. + +But you can see what's happening +inside their brain. + +And at two days old, here's the +left hemisphere response + +to language compared +to the right. + +So it's there instantly, +we believe. + +It's been there, actually in the +womb as the child's been + +developing. + +This left hemisphere, +genetically set up dominance + +for language in almost +everybody. + +fMRI, just for those +of you who-- + +again, we can start doing it +at about age five, but from + +about three months to age five, +it's incredibly hard to + +do children in a scanner. + +But the first couple days, +it's not so hard. + +Now, a really interesting +line of research has + +talked about motherese. + +Have you heard this term? + +So how do grown-ups, +even college + +students, talk to babies? + +Do you talk to babies +just like you talk + +to everybody else? + +No. + +Cute baby. + +Baby, baby. + +And everybody looks like +an idiot, right? + +And you could just think, OK, +that's just people being + +idiots around babies. + +But it turns out there's been +beautiful, beautiful studies + +to show that, while you +spontaneously do this-- and + +you and I don't take motherese +or fatherese courses-- + +but what we do spontaneously +is that way of elongating + +sounds, the intonations we give, +are incredibly perfect + +to help the baby +learn language. + +We're exactly doing what +they can understand. + +And that, again, must +be virtually in + +our genes, I think. + +We hear it around, +so it's not zero. + +But the short pauses, careful +enunciation, exaggerated + +intonation, that's-- + +you could do experiments where +you take language and you get + +rid of those, and the babies +are like-- they don't know + +what's going on. + +They're not interested. + +You put them back in, boom. + +Those are perfect +for the baby. + +It's amazing, not only how +babies are ready to go, but + +how adults who talk with +them are ready to go. + +I mean, it's just amazing. + +None of us will ever be as good +a teacher in a classroom + +as all of you will be +with a baby anytime + +you talk with them. + +It's just amazing. + +So there's beautiful experiments +that show that + +every time you tinker with the +way the mother spontaneously, + +or parents spontaneously, talk +to indants, you make it worse, + +less interesting, and less +informative for the infant. + +So now let's talk about a +more formal experiment. + +These are the classic experiment +that nailed home + +this message, that at birth +we're universal understanders + +of all sounds in the world. + +And as the years go along, we +became only good at the sounds + +that are relevant, that are +part of our own language. + +A famous example in the US is +a difficulty for Japanese + +native speakers for the +R-L distinction. + +But every language has some +distinctions it doesn't make, + +and they're really hard +when you get older. + +So here's the idea. + +In English, we make a +distinction between ba and da, + +and by 10 to 12 months, an +infant can make that + +distinction. + +And certainly, adults can. + +That's categorical perception +that we talked about, that + +kind of division between +ba and da. + +But there's sounds that occur +in other language. + +So we're shown here. + +And you're going to hear-- + +some of you may know Hindi +sounds, and it'll be a + +different experience for you. + +Every year, when I first hear +this clip I'm about to show + +you, I think something's +wrong. + +Because they say, the infant's +going to tell the difference + +between da and da. + +And I go, well, how are +they going to do that? + +I can't do that. + +That's because they really are +different sounds you're + +hearing, but in English, they're +not different sounds. + +And so it all sounds +the same to me. + +I'm no longer a universal +learner. + +I haven't been since +quite a while. + +So here we go. + +I'm stunned, always, by the +brilliance of infant + +researchers like this, who +somehow, pretty convincingly + +in most cases, really tell you +what the infant knows or pays + +attention to or thinks in pretty +compelling ways, even + +though they can't tell +you themselves. + +So one thing that's come +up in the US-- + +I mean, the whole world is +becoming ever more bilingual + +and trilingual. + +There used to be some concerns, +less now, and I'll + +tell you, you don't have +to worry about it. + +Whether it's bad to learn +two languages at once + +when you're a kid. + +And some parents worry +about this, right? + +You're going to be all messed +up because you're going to + +blend them all up and not +do well in school. + +And so there's been quite a +bit of research, actually, + +tracking and asking whether +there's any downside. + +I mean, there's huge +upsides to knowing + +two or three languages. + +Are there any downsides in terms +of language development? + +And the objective evidence is +pretty compelling that for + +babbling, for first words, for +pairs of words at a time, + +[INAUDIBLE] at two months, that +there's really no cost. + +So they followed, in Canada, for +example, children who grew + +up learning English and French, +English and ASL, + +French or English only. + +Everybody does the same, +pretty much. + +There's no cost, compared +to the huge gain. + +Sometimes some kids will +get a little mixed up. + +They'll actually mix up +languages because they'll just + +mix them up when they're +pretty young. + +But there's no developmental +delay of milestones or + +negative consequences. + +There's only the benefit of +having two or three languages + +that you could speak. + +So the evidence is overwhelming, +empirically, + +that there's no cost for +learning more than one + +language at a time when +you're an infant. + +One thing, there is a cost, a +little bit, if you're a boy. + +So unknown why this happened. + +I don't think there's any +deep science about it. + +But everybody has observed that, +for example, number of + +new words understood during the +first two years of life, + +that girls, on average, +outperform boys in language + +acquisition early on. + +And then things get closer, +pretty much. + +But the rate of learning +on girls on average + +is faster than boys. + +Nobody, I think, understands +the specific basis of that. + +So when people talk about +critical periods in language + +acquisition, and what are +fragile or resilient aspects + +of language. + +Which aspects of learning +language that seem very + +dependent on the age you are, +and which are independent. + +So phonology, including the +production of language sounds, + +seems very fragile. + +Easy when you're young, harder +when you're older. + +Grammar is also age-sensitive, +making subtle grammatical + +distinctions. + +Learning about meaning or +vocabulary, you're perfectly + +fine when you're an adult. + +That doesn't seem to +show something + +like a sensitive period. + +And here's one famous study +that established + +some of these things. + +They looked at what age people +arrive to different countries, + +from different countries +to the US and + +started learning English. + +These are people that didn't +know English before. + +They're all adults now, and +they had them do quickly + +grammatical judgments. + +And what they found is, if you +came to the US when you-- + +if you were born in the US, or +you came to the age three to + +seven, you were very +good at doing this. + +But the later you came here, 8 +to 10 years of age, 11 to 15, + +17 to 39, your ability to make +these fast, subtle grammatical + +judgments just went down. + +Even though you've been here, in +many cases, for many years. + +You're very smart. + +Accents are like that, right? + +People come to the US at a +certain point in their + +development. + +They're very skilled in +English, have a big + +vocabulary, but the accent +never disappears. + +That's another thing in terms +of language production that + +has its fragile developmental +early period. + +So the last thing I'll do, and +then show you a movie for + +about eight minutes. + +We get this occasional +horrible experiments. + +It's not even an experiment +of nature. + +It's just an experiment of +horrible human behavior. + +And the most famous one in +language development, which + +had a huge impact on +the field at the + +time, is a child, Genie. + +I'll show you. + +You'll see her in a movie +clip in a moment. + +They discovered her locked in +a room, in a house, from age + +20 months, approximately, +until they + +discovered her at 13. + +She almost spoke to no one. + +So the people taking care of +her locked her in a closet, + +basically, and did not talk +with her, or she had no + +language interactions +until she was + +discovered and rescued. + +And then they performed research +for years saying + +could she learn things, what +could she not learn. + +She got single words, for +example, but she never got + +particularly good at grammar. + +[INAUDIBLE] + +syntax. + +So a brutal way to test the idea +that what's acquirable + +later in life. + +And what, if you don't learn +it early in life, is + +impossible to acquire fully? + +So I'll end with this. + +We'll do this for five minutes +or seven minutes. + +I'll stop there. + +It's summarized in your book. + +Everybody knows about it because +it's this study you + +couldn't do ethically +in a million years. + +You would never do, which is if +you deprive a child of the + +critical period of language +exposure. + +And she never got lots of +aspects of language going. + +She got OK on a minimal +vocabulary, + +grew in other ways. + +But many of the things that, +from a language perspective, + +she never got because she missed +that critical period. + +So that's a bit of a sad story, +obviously, but have a + +good spring break and a +refreshing spring break. + +And I'll see you in 10 days. \ No newline at end of file diff --git a/gXRmNp4Wgb0.txt b/gXRmNp4Wgb0.txt new file mode 100644 index 0000000000000000000000000000000000000000..58fad75f7c01e6e277aa46e100e27dbfd080b0e2 --- /dev/null +++ b/gXRmNp4Wgb0.txt @@ -0,0 +1,4082 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +Let's get going here. + +So this is a lecture that's +actually appropriate for + +Halloween, because it's +a scary topic. + +Non-deterministic programming. + +So we've been looking mostly +at deterministic programs. + +So a program is deterministic +on a given input if every + +memory location is updated +with the same sequence of + +values in every execution. + +So if you look at the memory of +the machine, you can view + +that as, essentially, the +state of the machine. + +And if you're always updating +every memory location with + +exactly the same sequence of +values, then the program is + +deterministic. + +Now it may be that two memory +locations may be updated in a + +different order. + +So you may have one location +which is updated first in one + +execution, and another that's +second, and then in a + +different execution, they may +be a different order. + +That's OK, generally. + +The issue is whether or not +every memory location sees the + +same order. + +And if they do, then it's for +every execution, then it's a + +deterministic program. + +So what's the advantage +of having a + +deterministic program? + +Yeah? + +AUDIENCE: It always runs the +same way [INAUDIBLE]. + +PROFESSOR: It always +runs the same way. + +So what? + +What's that good for? + +AUDIENCE: So you can +find bugs easier. + +PROFESSOR: Yeah, debugging. + +It's really easy to find bugs +if every time you run it it + +does the same thing. + +It's much harder to find bugs +if, when you run it, it might + +do something different. + +So that leads to our first +major rule of thumb about + +determinism, which is you +should always write + +deterministic programs. + +Don't write + +non-deterministic programs. + +And the only problem is, boy +is that poor quality there. + +So basically, it says, always +write non-deterministic + +programs unless you can't. + +So sometimes, the only way to +get performance is to do + +something non-deterministic. + +So this lecture is basically +about some of the ways of + +doing non-deterministic +programming. + +So it's appropriate that we say +this is not for those who + +are faint of heart. + +We are treading into dangerous +territory here. + +So the basic rule is, as I say, +any time you can, make + +your program deterministic. + +So we're going to talk about the +number one way that people + +introduce non-determinism into +programs, which is via mutual + +exclusion and mutexes, which are +a type of lock, and then + +look at some of the anomalies +that you get. + +Besides just things being +non-deterministic, you can + +also get some very, very +weird behavior + +sometimes for the execution. + +So we'll start out with +mutual exclusion. + +So let's take a look, for +example, suppose I'm + +implementing a hash table +as a set of bins. + +And I'm resolving collisions +with chaining. + +So here, each slot of my hash +table has a chain of all the + +values that resolve +to that slot. + +And if I have a value x, let's +say it has key 81, and I want + +to insert x into the table, I +first compute a hash of x. + +And let's say it hashes to this +particular list here. + +And then what I do is +I say, OK, let me + +insert x into the table. + +So I make the next pointer of +x point to whatever is the + +head of the table. + +And then I make the +table 0.2x. + +And that effectively inserts +x into the hash table. + +Fairly straightforward +piece of code. + +I would expect that most of you +could write that even on + +an exam and get it right. + +But what happens when we say, +oh, let's have some + +concurrency. + +Let's have the ability to look +up things in a hash table in + +different parallel branches +of a parallel program. + +So here, we have a concurrent +hash table now where I've got + +two values, and I'm going to +have two different threads + +inserting x and y. + +So one of them is going to do +this one, and one of them is + +going to do this one. + +So let's just see how +this can screw up. + +So first, we hash x, +and it hashes to + +this particular slot. + +So then we do, just as we're +doing before, making its next + +pointer point to the beginning +of the array. + +Then y gets in the picture, +and it decides oh, + +I'm going to hash. + +And oh, it hashes to exactly +the same slot. + +And then y makes its next +pointer point to the same to + +the head of the list. + +And then it sets the head of +the list to point to y. + +So now y is in the list. + +Whoops, now x puts itself in the +list, effectively taking y + +out of the list. + +So rather than x and y both +being in the list, we have a + +concurrency bug. + +So this is clearly a race. + +So it's a determinacy race, +because we have two parallel + +instructions accessing +essentially the same location, + +at least one of which-- in +this case both of them-- + +performing a store +to that location. + +So that's a determinacy race. + +And how things are going to work +out depends upon which + +one of these guys goes first. + +Notice, as with most race bugs, +that if this code all + +executed before this +code, we're OK. + +Or if this code all executed +before this code, we're OK. + +So the bug occurs when they +happen to execute at + +essentially the same time and +their instructions interleave. + +So this is a race bug. + +So one of the classic ways of +fixing this kind of race bug + +is to insist on some kind +of mutual exclusion. + +So a critical section is a piece +of code that is going to + +access shared data that must not +be executed by two threads + +at the same time. + +So it shouldn't be accessed by +two threads at the same time. + +So it's mutual exclusion. + +So that's what a critical +section is. + +And we have a mechanism +that operating + +systems typically provide-- + +as well as runtime systems, but +you can build your own-- + +called "mutexes," or "mutex +locks," or sometimes just + +"locks." So a mutex is an object +that has a lock and + +unlock member function. + +And any attempt by a thread to +lock an already locked mutex + +causes that thread to block. + +And "block" is, by the way, +a hugely overused word in + +computer science. + +In this case, by "block," they +mean "wait." It waits until + +the mutex is unlocked. + +So whenever you have something +that's locked, somebody else + +comes and tries to +grab the lock. + +The mutex mechanism +only allows one + +thread to access it. + +The other one waits until +the lock is freed. + +Then this other one +can go access it. + +So what we can do is build a +concurrent hash table by + +modifying each slot in the table +to have both a mutex, L, + +and a pointer called "head" +to the slot contents. + +And then the idea is that +what we'll do is hash + +the value to a slot. + +But before we access the +elements of the slot, we're + +going to grab the lock +on the slot. + +So every slot in the table +has a lock here. + +Now, I could have a lock +on the whole table. + +What's the problem with that? + +Sure. + +AUDIENCE: [INAUDIBLE] + +basically can't do anything. + +You can't read. + +You couldn't be reading +from the table. + +PROFESSOR: Yeah, so +if you have a lock + +on the whole table-- + +AUDIENCE: You would defeat +the purpose [INAUDIBLE] + +PROFESSOR: You defeat the +purpose of trying to have a + +concurrent hash table, right? + +Because only one thread can +actually access the + +hash table at a time. + +So in this case, what we'll do +is we'll lock each slot of the + +hash table. + +And there are actually +mechanisms where you can lock + +each element of the +hash table or a + +constant number of elements. + +But basically, what we're trying +to do is make it so + +that the odds are that if you +have a big enough table and + +relatively few processors you're +running on, the odds + +that they'll conflict are +going to be very low. + +So what we do is we grab a lock +on the slot, and then we + +play the same game of inserting + +ourselves at the head. + +And then we unlock the slot. + +So what that does is it means +that only one of the two + +threads in the previous example +can actually execute + +this code at a time. + +And so it guarantees that the +two regions of code will + +either execute in this order or +in this order, and you'll + +never get the instructions +interleaved. + +Now, this is introducing +non-determinism. + +Why is this going to be +non-deterministic? + +Yes? + +AUDIENCE: [INAUDIBLE] lock +first, it'll be [INAUDIBLE]. + +PROFESSOR: Yeah, depending upon +which one gets the lock + +first, the length list in there +will have the elements + +in a different order. + +So a program that depends on +the order of that list is + +going to behave differently +from run to run. + +So let's recall the definition +of a determinacy race. + +It occurs when two logically +parallel instructions access + +the same memory location, +and at least one of the + +instructions performs a write. + +So that is, we do have a +determinacy race when we + +introduce locks. + +Locks are essentially, we're +going to have an intentional + +determinacy race. + +So a program execution with no +determinacy races means the + +program is deterministic +on that input. + +So if there are no determinacy +races, then although + +individual locations may be +updated in a different order + +in a parallel execution, every +memory location will be + +updated by exactly the same +thing at the same time. + +The order will be of update +of operations on any given + +location will be the +same always. + +So that's actually a theorem, +which we're + +not going to prove. + +But I think if you think +about it, it's fairly + +straightforward. + +If you never have two guys in +parallel that could possibly + +affect the same location, then +the behavior always is going + +to be the same thing. + +Things are going to get written +in the same order. + +So the program in that case +always behaves the same on + +that given input, no +matter how it's + +scheduled and executed. + +We'll always have essentially +the same behavior, even though + +it may get scheduled +one way or another. + +And one of the nice things +that we have in our race + +detection tool Cilkscreen is +that if we do have determinacy + +races that exist in +an ostensibly + +deterministic program-- + +that is, a program +with no mutexes. + +If basically it just reads and +writes on locations and so + +forth, then Cilkscreen +guarantees + +to find such a race. + +So It's nice that we get a +guarantee out of Cilkscreen. + +So this is all beautiful, +elegant, everything works out + +great if there are no +determinacy races. + +But when we do something like a +concurrent hash table, we're + +intentionally putting in +a determinacy area. + +So that asks sort of +a natural question. + +Why would I want to have a +concurrent hash table? + +Why not make it so that my +program is deterministic? + +Why might a concurrent hash +table be an advantageous thing + +to have in a program that +you wanted to go fast? + +Some ideas? + +Where might you want +to use it? + +Yeah? + +AUDIENCE: Speed? + +PROFESSOR: Yeah, speed. + +But I mean, what's +an application? + +What's a use case, as the +entrepreneurs would ask you? + +Where is it that you would +really want to use a + +concurrent hash table +to give you speed? + +Yeah? + +AUDIENCE: If you started +using it [INAUDIBLE] + +along with your system +[INAUDIBLE] + +values. + +PROFESSOR: Yeah, it could be +that there's some sort of + +global table that you want a +lot of people to be able to + +access at one time. + +So if you lock down and only had +one thread accessing at a + +time, you reduce how +much concurrency + +that you could have. + +That's a good one. + +Yeah? + +AUDIENCE: Perhaps most of the +time, people are just reading. + +So if you had something +concurrent, your reading + +should be fine. + +So in that case, a lot more +reading high performance + +[INAUDIBLE] + +PROFESSOR: Yeah, so in fact, +there's a type of lock called + +a reader-writer lock, which +allows one writer to operate, + +but many readers. + +So that's another type of +concurrency control. + +So just another place, a common +place that you use it, + +is when you're memoizing. + +Meaning I do a computation, I +want to remember the results + +so that if I see it again, I +can look it up rather than + +having to compute it +again from scratch. + +So you might keep all those +values in a hash table. + +Well, if I go in the hash table, +now I'm going to have + +concurrent accesses to that +hash table if I've got a + +parallel program that wants +to do memorizing. + +And there are a bunch +of other cases. + +So we have determinacy races. + +And we have a great guarantee +that if there is a race, we + +guarantee to find it. + +Now, there's another type of +race, and in fact, you'll hear + +more about this type of race +if you read the literature + +than you hear about +determinacy races. + +So a data race occurs when you +have two logically parallel + +instructions holding +no locks in common. + +And they access the same +location, and at least one of + +the instructions performs +a write. + +So this is saying that +I've got accesses. + +And if they have no +locks in common-- + +so it could be that you have +a problem where one of them + +holds a lock L, and another +one holds L prime. + +And then they access the +location, that's going to be a + +data race, because they don't +hold locks in common. + +But if I have L and L being the +locks that the two threads + +hold, and they access the +same location, that's + +not a data race now. + +It is a determinacy race, +because it's going to matter + +which order it is, but it's not +a data race, because the + +locks, in some sense, are +protecting access. + +So Cilkscreen, in fact, +understands locks and will not + +report a determinacy race unless +it is also a data race. + +However, since codes that use +locks are non-deterministic by + +intention, they actually weaken +Cilkscreen's guarantee. + +And in particular, in its +execution that it does, if it + +finds a data race, it's going +to say, I'm going to ignore + +that data race. + +But now it is only going to +follow one of the two paths + +that might arise from +that data race. + +In other words, it doesn't +follow both paths. + +If you could think about it, +when one of them wins-- + +so you have a race between +two critical sections. + +When one of them wins, you can +imagine that's one possible + +outcome of the computation. + +When the other wins, +it's another path. + +And what Cilkscreen does +is it picks one path. + +In fact, it picks the path which +is the one that would + +occur in the cereal execution. + +So there's a whole path there +that you're not exploring. + +So Cilkscreen's guarantee is not +going to be strong there. + +However, if the critical +sections, in fact, commute-- + +that is, they do exactly +the same thing, no + +matter what the order. + +So for example, if they're both +incrementing a value, + +then the result, after doing one +versus after the other is + +the same value, then you get a +guarantee out of Cilkscreen. + +So Cilkscreen could still be +very helpful for finding bugs, + +because typically, when you +organize your computation, if + +it occurs in this order, +there's typically some + +execution or input where you can +make things occur in the + +other order. + +So you can actually cover more +races than you might imagine + +on first blush. + +But it is a danger. + +But what we're talking about +today is dangerous + +programming, non-deterministic +programming. + +So when you start using +mutexes, some of the + +guarantees and so forth +get much dicier. + +Any questions about that? + +Now, if you have no data races +in your code, that doesn't + +mean that you have no bugs. + +So for example, here's a way +somebody might fix that + +insertion code. + +So we hash the key, we grab a +lock, we set x next to be + +whatever is the head +of the list, and + +then we do an unlock. + +And now we lock it again. + +Now we follow the +head to set x-- + +sorry, we set x to be +the head of the list + +and then unlock again. + +And now notice that in this +case, technically, there is no + +data race if I have two +concurrent threads trying to + +access these at a time, because +all the axis I'm + +doing, I'm holding lock L. +Nevertheless, I can get that + +same interleaving of code +that causes the bug. + +So just because you don't have +a data race doesn't mean that + +you don't have a bug +in your code. + +As I say, this is dangerous +programming. + +However, typically, if you +have mutexes and no data + +races, usually it means that you +went through and thought + +about this code. + +And if you were thinking about +this code, you would say, gee, + +really I'm trying to make these +two instructions be the + +critical section. + +Why would I unlock +and lock again? + +So most of the time, as a +practical matter, if you don't + +have data races, it probably +means you did the right thing + +in terms of identifying the +critical sections that needed + +to be locked and not unlocking +things in the middle of them. + +So as a practical matter, no +data races usually means it's + +unlikely you have bugs. + +But no guarantees. + +As I say, dangerous +programming. + +Non-deterministic programming +is dangerous program. + +Any questions about that? + +Anybody scared off yet? + +Yeah? + +AUDIENCE: So what you can +do is the opposite. + +You don't have any bugs, but +you made the critical + +distinction to [INAUDIBLE] + +PROFESSOR: Yes, so certainly +from a performance point of + +view, one of the problems +with locking is that-- + +and we'll talk about this +a little bit later-- + +with locking is that if you have +a large section that you + +decide to lock, it means +other threads can't do + +work on that section. + +So they're spinning, +wasting cycles. + +So generally, you want +to try to lock + +things as small as possible. + +The other problem is, it turns +out that there's overhead + +associated with these locks. + +So if there's overhead +associated with the locks, + +that's problematic as well, +because now you + +may be slowing down. + +If this is in an inner loop, +notice that we've now, even if + +I just have the lock and unlock +without these two + +spurious ones here, we +may be more than + +doubling the overhead. + +In fact, locking instructions +tend to be much more expensive + +than register operations. + +They usually cost something on +the order of going to L2 cache + +as a minimum. + +So it's not even L1 cache. + +It's like going out +to L2 cache. + +Now, it turns out there +are some times where + +you have data races. + +So we say if there are no data +races, then you have no + +guarantee there's no bugs. + +If there are data races, your +program still may be correct. + +Here's an example of a code +where you might want to allow + +a benign data race. + +So here we have, let's say, +an array A that has these + +elements in it. + +And we want to find, +what is the set of + +digits in the array? + +So these are all going to be +values between 0 and 9. + +And I want to know which +ones are present of + +the digits 0 to 9. + +Which ones are not present? + +So I can write a little +code for that. + +Let me initialize an array +called "digits" to have + +all-zero entries. + +And now let me go through all +the elements of A and set + +digits of whatever the +digit is to be 1. + +So set at 1 if that +digit is present. + +And I can do that in +parallel, even. + +So what can happen here is I can +have, if I've done this in + +parallel, this particular update +of digits of 6 will be + +set to 1 when this one +is being sent to 1. + +Is that a problem? + +In some sense, no. + +They're both being set to 1. + +Who cares? + +But there is a race there. + +There is a race, but +it's a benign race. + +Well, it may or may +not be benign. + +So there's a gotcha +on this one. + +So this code only works +correctly if the hardware + +writes the array elements +atomically. + +So for example, not +on the x86-64 + +architecture we're using. + +But on some architectures, you +cannot write a byte value. + +You cannot write a byte value +as an atomic operation. + +It implements a right to a +byte by reading a word, + +masking out things, changing the +field, masking again, and + +then writing it back out. + +So you can have a race +on a byte value. + +In particular, even if I were +going to do this with bits, I + +could have a race on bits, +although C doesn't let me + +access bits directly. + +The smallest unit I can +access is a byte. + +So you have to worry about +what's the level of atomicity + +provided by your architecture? + +So the x86 architecture, the +grain size of atomic update is + +you can do a single-byte write, +and it will do the + +right, proper thing-- + +do the right thing +on the write. + +So we have both things. + +No bugs. + +No data races doesn't +mean no bugs. + +Presence of data races doesn't +mean you have bugs. + +But generally, they're fairly +well overlapped. + +Now, why would I not want to put +in a lock and unlock here + +just to get rid of the race? + +If I run Cilkscreen on this, +it's going to complain. + +It's going to say, you've +got a race here. + +Why would I not want to put a +lock on here, for example? + +AUDIENCE: Because then we don't + +have parallelism anymore? + +PROFESSOR: No, well, I'd have +parallelism maybe up to 10, + +for example, right? + +Because I have 10 different +things that could be + +going on at a time. + +But that's one reason. + +That is one reason. + +What's another reason why +I might not want to + +put locks in here? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: It could be that +all the numbers-- + +that's a case where it doesn't +get me much speedup. + +But what's another reason +I might want to do this? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: I think you're +on the right track. + +Overhead. + +Yeah. + +Overhead. + +This is my inner loop. + +So if I'm locking and unlocking, +all this is doing + +is just doing a memory +[? dereference ?] + +and an assignment. + +And that may be fairly cheap, +whereas if I grab a lock and + +then release the lock, those +operations may be much, much + +more expensive. + +So I may be slowing down the +execution of this loop by more + +than I'm going to gain out of +the parallelism of this. + +So I may say, I may reason, hey, +there is a good reason + +why not have a data +race there. + +So I may want to have a data +race, and I may want + +to say that's OK. + +And if that happens, however, +you're now going to get + +warnings out of Cilkscreen. + +And I generally recommend that +you have no warnings on + +Cilkscreen when you +run your code. + +So the Cilk environment provides +a mechanism called + +"fake locks." So a fake lock +allows you to communicate to + +Cilkscreen that a race +is intentional. + +So what you then do is you put +a fake lock in around this + +access here. + +And what happens is when +Cilkscreen runs, it says, oh, + +you grabbed this lock, so I +shouldn't report a race. + +But during execution, no lock +is actually grabbed, because + +it's a fake one. + +So it doesn't slow you down it +all at runtime, but Cilkscreen + +still thinks that a lock +is being acquired. + +Questions about that? + +So this is if you want to have +an intentional race, this is a + +way you can quiet Cilkscreen. + +Of course, it's dangerous, +right? + +It's yet another example of +what's dangerous here. + +Because what happens if +you did it wrong? + +What happens if there really +is a bug there? + +You're now telling it +to ignore that bug. + +So one way that you can +make your code-- + +if you put in fake locks +everywhere, you could make it + +so, oh, Cilkscreen runs just +great, and have your code full + +of race bugs. + +So if you use fake locks, you +should document very carefully + +that you're doing so and why +that's going to be a safe + +thing to do. + +Any questions about that? + +By the way, one of the nice +things about some of the + +concurrency platforms like Cilk +is that they provide a + +layer of abstraction where +generally, you don't have to + +do very much locking. + +If you program with Pthreads, +for example, you're locking + +all the time. + +So you're writing +non-deterministic programs all + +the time, and you're debugging +non-deterministic + +programs all the time. + +Whereas Cilk provides a layer +of programming where you can + +do most of your programming in +a deterministic fashion. + +And occasionally, you may want +to have some non-determinism + +here or there. + +But hopefully you can manage +that if you do it judiciously. + +Any questions about +mutexes and uses + +for them and so forth? + +Good. + +So let's talk about how +they get implemented. + +Because as with all these +things, we want to understand + +not just what the abstractions +is but how it is that you + +actually implement these things +so that you can reason + +about them more cogently. + +So there's typically three major +properties of mutexes + +when you look at them. + +And when you see documentation +for mutexes, you should + +understand what the difference +is of these things. + +The first is whether it's +a yielding mutex + +or a spinning mutex. + +So a yielding mutex, when you +spin, it returns control to + +the operating system. + +And why might you +want to do that? + +Whereas a spinning one just +consumes processor cycles. + +Why would you want to do that? + +Yeah. + +AUDIENCE: [INAUDIBLE] +allow other threads. + +PROFESSOR: Yeah, it can allow +other threads or other jobs + +that could be running +to use the processor + +while you're waiting. + +What's the downside of that? + +To speak to the-- either one. + +Go ahead. + +AUDIENCE: It might be possible +that whatever you're trying to + +do is essential, and you really +want to get that done + +[UNINTELLIGIBLE] everything +else executes. + +So you really want [INAUDIBLE] + +PROFESSOR: Yeah, context +switching a thread out is a + +heavyweight operation. + +And It may be, if you end up +context switching out, it may + +be you only had to wait for a +half a dozen cycles and you'd + +have the lock. + +But instead, now you're going +and you're doing a context + +switch and may not get access +to the machine for another + +hundredth of a second +or something. + +So it may be on the order of +10 to the 6th-- a million + +instructions before you +get access again, + +rather than just a few. + +The second property of mutexes +is whether they're + +reentrant or not. + +So a reenttrant mutex allows a +thread that's holding a lock + +to acquire it again. + +So I may hold the lock, and then +I may try to acquire the + +lock again. + +Java is full of reentrant locks, +reentrant mutexes. + +So why is this a positive +or negative? + +What are the pros and +cons of this one? + +Why might reentrancy be +a good thing to want? + +Why would I bother doing-- + +why would I grab a lock +that I already have? + +AUDIENCE: It'd be too easy to +do a check [INAUDIBLE]. + +PROFESSOR: It lets +you do what? + +AUDIENCE: It lets you not have +to worry about locking when + +you already have a lock. + +PROFESSOR: It lets you +not worry about it. + +That's right. + +But why is that valuable? + +AUDIENCE: It saves you one +line in an If statment to + +check if you have +a lock or not. + +PROFESSOR: That could be. + +Basically, the If statement +is embedded in there. + +But why would I care? + +Why would I want to be acquiring +something that I + +already have? + +In what programming situation +might that arise? + +This seems kind of +weird, right? + +Could be recursion. + +Yeah. + +So usually, what it comes from +is when you have objects, and + +you have several methods +on the object. + +And what you'd like to do is, +if somebody's calling the + +method from the outside, you +would like to be able to + +execute that particular-- + +I guess in C++ they don't call +them "methods." They call them + +"member functions." "Member +functions," they call them. + +In Java, they call them +"methods," and in C++, they + +call them "member functions." +Doesn't matter. + +It's the same thing. + +So when you access one of these, +normally, from the + +outside, you want to make sure +you grab the lock associated + +with the object. + +However, it may be that what +you're doing inside the object + +is you want to be able-- + +one of the operations may be a +more complex operation that + +wants to use one of its +own implementations. + +So rather than implementing +it twice-- + +once in the locked form, once +without getting the lock-- + +you just implement it once, and +you use reentrant locks. + +And that way, you don't have +to worry about, in coding + +those things, whether or not +you've already got it. + +So that's probably the most +common place that I know that + +people want reentrant locks. + +Naturally, to acquire a +reentrant lock, you have to do + +some kind of If statement, +which is a conditional. + +And as you know, if it's an +unpredictable branch, that's + +going to be very expensive. + +So generally, there is a cost +to making it reentrant. + +The third property is whether +the lock is fair or unfair. + +So a fair mutex puts block +threads essentially into a + +FIFO queue. + +And the unlock operation +unblocks the thread that has + +been waiting the longest. + +So it makes it so that if you +try to acquire a lock, you + +don't have some other thread +coming in and trying to access + +that lock and getting +ahead of you. + +It puts you in a queue. + +So an unfair mutex lets any +blocked thread go next. + +So the cheapest thing to +implement is a spinning, + +non-reentrant, unfair lock-- + +mutex. + +Those are the cheapest +ones to implement. + +Very lightweight, very +easy to use. + +The heavyweight ones +are a yielding, + +reentrant, fair lock. + +And of course, you can have +combinations, because all of + +these have, as you can see, +different properties in terms + +of convenience of use and +so forth, as well + +as different overheads. + +So there's some cases where the +overhead isn't a big deal + +because it's not in the inner +loop of a program or a heavily + +executed statement. + +So let's take a look at one of +the simplest locks, which is a + +simple spinning mutex. + +This is the x86 code for +how to acquire a lock. + +So let's run through this. + +So we start out at the top. + +And I check to see if the +mutex is 0, which is + +basically, it's going to be 0 +if it's free and 1 if it has + +been acquired. + +So we compare it. + +If it's free, then I jump +to try to get the mutex. + +Otherwise, I execute this PAUSE +instruction, and this + +turns out to be a-- + +it's humorous. + +It's x86 hack to un-confuse +the pipeline. + +So it turns out that in this +case, if you don't have a + +pause here-- + +which is no-op and +does nothing-- + +x86 mispredicts something or +whatever, and it's more time + +consuming than if it doesn't +have that there. + +The manual explains very little +about this hardware bug + +except to say, put +in the pause. + +So if you didn't get it, then +you jump to spin mutex, and + +try again, check to +see if it's free. + +Now, notice that we're going to +spin until it's free, and + +then we're going to +try to get it. + +Why not just try to +get it first? + +Well, think about that while we +go through how to get it, + +and then I'll ask it again. + +Think about why it is that you +might want to get it first. + +So if I want to get the +mutex, I first get a + +value of 1 in my register. + +And then I compute this exchange +operation, which + +exchanges the value of the mutex +with the value of the-- + +with the one that I have. + +So it exchanges the memory +location with the register. + +Now, this is an expensive +operation-- + +exchange-- + +because it's an atomic exchange, +and it typically has + +to go at least out +to L2 to do this. + +So it's an expensive operation, +because it's a + +read-modify-write operation. + +I'm swapping my register +value with a value + +that's in the mutex. + +So it turns out that if it's +0, then it means I got it. + +So I compare it with 0, and if +it's equal to 0, I go onto the + +critical section. + +When I'm done with the critical +section, I release + +the mutex by basically storing +0 in there, because I'm the + +only one who accesses the +mutex at this point. + +If I didn't get it, if the +value is 1, notice that + +because I'm swapping a 1 in, +even though the 1 got swapped + +in, well, there was +a 1 there before. + +So it basically did not affect +the value of the mutex. + +But I discover, oh, +I don't have it. + +Then we go all the way back +up there to spin mutex. + +So here's the question. + +Why do I need all this +preamble code? + +Why not just go straight to +Get_Mutex, make the spin mutex + +here be a jump to Get_Mutex? + +Yeah? + +AUDIENCE: Maybe it's because +the exchange is expensive. + +PROFESSOR: Excuse me? + +AUDIENCE: The exchange is-- + +PROFESSOR: Yeah, because the +exchange is expensive. + +Exactly. + +So this code here, +I can compare. + +And as long as nobody's touching +anything, this + +becomes just L1 memory +accesses. + +Whereas here, it's going +to be at least L2 to do + +the exchange operation. + +So rather than doing that-- + +moreover, this one actually +changes the value. + +So what happens when I change +the value of the mutex? + +Even though I change it to the +same value, what happens in + +order to do that exchange? + +Remember from several +lectures ago. + +What's going to happen when +I make an exchange there? + +What does the hardware +have to do? + +What's the hardware going to +do on any store to a shared + +memory location, to a memory +location in shared memory that + +is actually shared? + +Yeah? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yeah, it's +got to invalidate + +all the other copies. + +So if everybody spinning here-- +imagine that you have + +five guys spinning, +doing exchanges-- + +they're all creating all this +traffic of invalidations, + +what's called an "invalidation +storm." So they create an + +invalidation storm as they all +are invalidating each other so + +that they can get access to it +so that they can change the + +value themselves. + +But up here, all I'm doing +is looking at the value. + +All I'm doing is looking at the +value to see if it's free. + +And it's not until the guy +actually frees the value that + +it actually-- + +actually, this is interesting. + +I think I wrote this with Intel +syntax, rather than + +AT&T, didn't I? + +The MOV mutex, 0 moves +0 into the mutex, + +which is Intel syntax. + +I probably should have converted +this to AT&T, + +because that's what we're +generally using in the class. + +I'll fix that before I +put the slides up. + +Basically, I pulled this out +of the Intel manual. + +So any questions about +this code? + +Everybody see how it works? + +It relies on this atomic +exchange operation. + +And I'm going to end up sitting +here spinning until + +maybe I can get access to it. + +When I have a chance to get +access to it, I try to get it. + +If I don't get it, I go +back to spinning. + +How do I convert this +to a yielding mutex? + +AUDIENCE: Instead +of having that + +spinning mutex, you should-- + +you shouldn't have that. + +You should just have something +that allows you to just + +[INAUDIBLE]. + +PROFESSOR: Yeah, so actually, +the way you do it is you + +replace the PAUSE instruction. + +Exactly what you're saying. + +You've got the right +place in the code. + +We basically call a yield. + +And you can use, for example, +pthread_yield. + +What it tells the operating +system is, + +give up on this quantum. + +You can schedule me out. + +Somebody else can +be scheduled. + +Now, if nobody else is there to +be scheduled, often you'll + +just get control back, and +you'll jump again and give the + +operating system another time. + +Now, one of the things I've seen +in computer benchmarks + +that use locking is that they +all use spin locks. + +They never use the yielding, +because if you yield, then + +when the lock comes free, you're +not going to be ready + +to come back in. + +You may be switched out. + +So a common thing that all +these companies do when + +they're vying for who's got the +fastest on this benchmark + +or fastest on that benchmark +is they go through and they + +convert all their yielding +mutexes into spinning mutexes, + +then take their measurements, +when in fact, as a practical + +matter, they can't actually +ship code that way. + +So you'll see this kind of game +played where people try + +to get the best performance +they can in some kind of + +laboratory setting. + +It's not the same as when +you're actually + +doing a real thing. + +So you have a choice here. + +There's kind of a +tension here. + +You'd like to claim the mutex +soon after it's released. + +And you're not going to +get that if you yield. + +At the same time, you want +to behave nicely + +and waste few cycles. + +So what's the strategy for being +able to accomplish both + +of these goals? + +So one of these goals is the +spinning mutex does a great + +job of claiming the mutex soon +after it's released. + +The yielding mutex behaves +nicely and wastes few cycles. + +Is there the best +of both worlds? + +There's certainly the worst +of both worlds, right? + +What's the best of +both worlds? + +How might we accomplish both +of these goals with small + +modification to the +locking code? + +So it turns out you +can get within a + +factor of two of optimal. + +How might you do that while +wasting few cycles? + +So here's the idea. + +Spin for a little while, and +then, if after a little while + +you didn't manage to access +the mutex, then yield. + +So that if the new mutex was +right there available to be + +accessed, you could access it, +but you don't spin for an + +indefinite amount of time. + +So the question is, how +long do you spin? + +So we're going to spin for a +little while and then yield. + +Yeah? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Yeah, exactly. + +So what you do is you spin for +basically as long as a context + +switch takes. + +So if you spin for as long as +it takes to do a context + +switch and then do a context +switch, if the mutex became + +immediately available, well, +you're only going to wait + +double what you would +have waited. + +And if in the meantime during +that first part where you're + +spinning it becomes available, +you're not waiting at all any + +longer than you actually +have to. + +So in both cases, you're +waiting at + +most a factor of two. + +In one case, you're waiting +exactly the right. + +The other, you can actually +wait a factor of two. + +So this is a classic amortized +kind of argument, that you can + +amortize the cost +of the spinning + +to the context switch. + +So spin until you spend as much +time as it would cost for + +a context switch. + +Then do the context switch. + +Yet another voodoo parameter. + +Yeah, so if the mutex is +released while spinning, + +that's optimal. + +If the mutex is released +after the yield, you're + +within twice optimal. + +Turns out that 2 is not +the optimal value. + +There's a randomized algorithm +that makes it e over e minus 1 + +competitive where e is the base +of the natural logarithm. + +So 2.7 divided by 1.7, +which is what? + +Who's got a calculator? + +2.7 divided by 1.7 is-- + +I should have calculated +this out. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: It's about 1.6. + +Good. + +So it's better than 2. + +People analyze these +things, right? + +So any questions about +implementation of locks? + +There are many other ways +of implementing locks. + +There are other instructions +that people use. + +They do things like +compare-and-swap is another + +operation that's used. + +There are some machines have +an operation called + +load-linked/store-conditional, +which is not on the x86 + +architecture, but it is on +other architectures. + +You'll see a lot of other things +of doing some kind of + +atomic operation to +implement a lock. + +Uniformly, they're expensive +compared to register + +operations in particular or even +L1 accesses, typically, + +in particular. + +Any questions? + +So now that we've decided that +we're going to use mutexes, + +and we understand we're writing +non-deterministic code + +and so forth, well, it turns out +there are a host of other + +system anomalies that occur. + +So locks are like, they're this +really evil mechanism + +that works really well. + +It feels so good that +nobody wants to stop + +using it, even though-- + +but nobody has better ideas. + +One of the most interesting +ideas in recent memory is the + +idea of using what's called +"transactional memory," which + +is basically where memory +operates like a database + +transaction. + +And it's allowed to abort, in +which case you roll it back + +and retry it. + +Yet, transactional memory has a +host of issues with it, and + +still people use locks. + +So let's talk about some of +the bad things that happen + +when you start doing locks. + +I'm going to talk about three of +them, deadlock, convoying, + +and contention. + +So deadlock is probably the most +important one, because it + +has to do with correctness. + +So you can have coded-- in fact, +I've seen people with + +very fast code that has deadlock +potential in it. + +It's like, if you deadlock, then +your average running time + +is infinite if there's +a possibility + +of a deadlock, right? + +Because you're averaging +infinity with everything else + +that you might run. + +So it's not good to have +deadlock in your code, + +regardless. + +It's kind of like your +code seg faulting. + +No decent code should +seg fault. + +It should always catch its +own errors and terminate + +gracefully. + +It shouldn't just seg fault +in some circumstance. + +Similarly, your code should +not deadlock. + +So here's sort of a classical +instance of deadlock. + +And deadlock typically occurs +when you hold more than one + +lock at a time. + +So here, this guy is going to +grab a lock A, going to grab a + +lock B, then unlock B, unlock +A, and in there + +do a critical section. + +Why might I grab two locks? + +What's the circumstance where I +might have code that looked + +very similar to this? + +Use case. + +AUDIENCE: Two objects? + +PROFESSOR: sorry? + +AUDIENCE: You need +two objects. + +PROFESSOR: You need +two objects. + +When might that occur? + +AUDIENCE: Account +transactions. + +PROFESSOR: Yeah, account +transactions. + +That's the classic one. + +You want to move something from +this bank account to that + +bank account. + +And you want to make sure that +as you're updating it, nothing + +else is occurring. + +Another place this comes up all +the time is when you do + +graph algorithms. + +You always want to grab the edge +and have the two vertices + +on each end of the edge not move +while you do something + +across the edge. + +So lots of cases there. + +It turns out the order in +which you unlock things + +doesn't matter, because you can +always unlock something. + +You never hold up +for unlocking. + +The problem with deadlock +is generally + +how you acquire locks. + +So in this example, Thread 2 +grabs Lock B, then grabs Lock + +A. So it might be, for example, +that you have some + +random process that's at +the node of a graph. + +And now it's going to +grab a lock on the + +other end of an edge. + +But you might have the guy at +the other end grabbing that + +vertex and then grabbing +the one on your end. + +And that's basically +the situation. + +So what happens is Thread +1 acquires a lock here. + +Thread 2 acquires that lock. + +And now which one can go? + +Neither of them. + +You've got a deadlock. + +Ultimate loss of performance. + +So it's really a correctness +issue. + +But you can view it, if you +really say, oh, correctness, + +that's for sissies. + +We do performance. + +Well, it's still a performance +issue, because it's the + +ultimate loss of performance. + +In fact, that's probably true +of any correctness issue. + +No, that's not true. + +Sometimes you just get +the wrong number. + +Here is a correctness +issue that + +your code stops operating. + +So there are three conditions +that are usually pointed to + +that you need for deadlock. + +The first is mutual exclusion. + +Each thread claims exclusive +control over the resources + +that it holds, in this case, the +resources being the locks. + +So there's got to be some +resource that you're grabbing, + +and that you're the only one +who gets to have it. + +So in this case, it would +be the locks. + +The second is non-preemption. + +You don't let go of your +resources until you complete + +your use of them. + +So that means you can't let go +of a lock in a situation. + +If you're actually +able to preempt-- + +so this piece of code over there +has grabbed locks, and + +now I can come in and take them +away, then you may not + +have a deadlock potential. + +You may have other issues, +but you won't + +have a deadlock potential. + +And the third one is +circular waiting. + +You have a cycle of threads in +which each thread is blocked + +waiting for resources held by +the next thread in the cycle. + +So let me illustrate this with +a very famous story that some + +of you may have seen, because +it is so famous. + +It's the dining philosophers +problem. + +It's an illustrative story a +deadlock that was originally + +told by Tony Hoare, based on +an examination question by + +Edsger Dijkstra. + +And the story has been +embellished over the years by + +many retellers. + +It's one of these things that +if you're a computer + +scientist, you should know +this story just because + +everybody knows this story. + +So here's how the story goes, +at least my version of it. + +I get to retell it now. + +So each of n philosophers needs +the two chopsticks on + +either side of his or +her plate to eat the + +noodles on the plate. + +So they're not worried about +germs here, by the way. + +So you have five philosophers +in this case + +sitting around the table. + +There are five chopsticks +between them. + +In order to eat, they need to +grab the two chopsticks on + +either side. + +Then they can eat. + +Then they put them down. + +So here's what philosopher +i does. + +So in an infinite loop, the +philosopher does thinking, + +because that's what +philosophers do. + +Then it grabs the lock of +chopstick i and grabs the lock + +of chopstick i plus 1. + +That's the 1. + +So if we index them, say, to the +left of the plate, this is + +grabbing the chopstick to +the left of your plate. + +This is grabbing the chopstick +to the right of your plate. + +Then you can eat. + +Then you release your +two chopsticks. + +So here, that's the code. + +And then you go back +to thinking. + +I guess they have no other +bodily functions. + +So the problem is, one day they +all pick up their left + +chopsticks simultaneously. + +Now they go to look for +their right chopstick. + +It's not there. + +So what happens? + +They starve because their code +doesn't let them release-- + +there's no preemption, so they +can't release the chopstick + +they've already got. + +And we have a circular +waiting. + +They have mutual exclusion. + +Only one of them can have +a chopstick at a time. + +And we have a circular waiting +thing, because everyone is + +waiting for the philosopher +on the right. + +Is that clear to everybody? + +That's the dining philosophers +problem. + +How do you fix this problem? + +What are solutions to +fixing this problem? + +The problem being that you'd +like them to eat indefinitely. + +AUDIENCE: You can index the +chopstick and say that + +[INAUDIBLE]. + +PROFESSOR: Yeah, you can pick +the smaller index first. + +So in general, that means +everybody would grab the one + +on their left, then the one on +their right, except for the + +guy who's going between +0 and n minus 1. + +They would do n minus +1 and then 0. + +They would do n minus +1 first, and then 0. + +Sorry. + +They would do 0 first, +and then n minus 1. + +[INAUDIBLE] + +Let me say that more +precisely. + +So this is a classic way +to prevent deadlock. + +Suppose that we can linearly +order the mutexes in some + +order so that whenever a thread +that holds a mutex Li + +and attempts to lock another +mutex Lj, we have it that Li + +goes before Lj in +the ordering. + +Then no deadlock can occur. + +So always grab the resource so +if they can all order the + +resources-- + +so they're always grabbing them +in some subsequence of + +this order, so they're always +grabbing one that's larger and + +larger and larger, and you're +never going back and grabbing + +one smaller, than you +have no deadlock. + +Here's why. + +Suppose you have a +cycle of waiting. + +You have a deadlock +has occurred. + +Let's look at the thread in +the cycle that holds the + +largest mutex that's called +Lmax in the ordering. + +So whatever is in +the ordering. + +And suppose that it's waiting on +a mutex L held by the next + +threat in the cycle. + +That's the condition. + +Well, then it must be that Lmax +falls before L, because + +we're gathering them always +in an increasing order. + +But that contradicts the fact +that Lmax is the largest. + +So a deadlock cannot occur. + +Questions? + +Is this clear? + +Who's seen this before? + +A few people. + +OK. + +Is this clear? + +So if you grab them in +increasing order, then there's + +always some guy that has the +largest one, and nobody is + +holding one larger. + +So he can always grab +the next one. + +So in this case of the dining +philosophers, what we can do + +is grab the minimum of i and +i plus 1 mod n and then the + +maximum of i and +i plus 1 mod n. + +That gives us the same +two chopsticks. + +And in fact, for most of the +philosophers, it's exactly the + +same order. + +But for one guy, it's +a different order. + +It ends up being the guy who +would normally have done n + +minus 1 and 0. + +Instead, he does 0, n minus 1. + +So in some sense, it's like +having a left-handed + +person at the table. + +You grab your left, then your +right, except for one guy does + +right and then left. + +And that fixes it, OK? + +That fixes it. + +Good. + +So that's basically the dining +philosophers problem. + +That's one way of fixing it. + +There are actually other +ways of doing it. + +One of the problems with this +particular solution is you + +still can have a long +chain of waiting. + +So there are other schemes that +you can use where, for + +example, if every other one +grabs left and then right and + +then right and then left and +then left and then right and + +then right and left and so +forth, you can end up making + +it so that nobody has to +wait to go all the + +way around the circle. + +Yeah? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Well, that would be +a preemption type of thing, + +where I grab one, and if I +didn't get it in time, I + +release it and then try again. + +When you have something like +that, there's an issue. + +It's, how do you set +the timeout amount? + +And the second issue that you +get into when you do timeouts + +is, how do you know you don't +then repeat exactly the same + +thing and convert a +deadlock situation + +into a livelock situation? + +So a livelock situation is +where they're not making + +progress, but they're all +busily working, thinking + +they're making progress. + +So you timeout. + +Let's try again. + +What makes you think that the +guys that are deadlocking + +aren't going to do exactly +the same thing. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: And exactly. + +And in fact, that's actually +a workable scheme. + +And there are schemes +that do it. + +Now, that's much more +complicated. + +Sometimes has more overhead, +especially because things + +become available. + +And it's like, no, you're busy +raiding some random amount of + +time before you try again. + +So this is, by the way, the +protocol that is used on the + +Ethernet for doing contention +resolution. + +It's what's called "exponential +backoff." And + +various backoff schemes are +used in order to allow + +multiple things acquire +mutually-exclusive access to + +something without having to +have a definite ordering. + +So there are solutions, but +they definitely get more + +heavyweight. + +It's not lightweight. + +Whereas if you can prevent +deadlock, that's really good, + +because you just simply +do the natural thing. + +And that tends to +be pretty quick. + +But yeah, all I'm doing is +sort of covering the + +introduction to all +these things. + +There are books written on +this type of subject. + +Any other questions about +dining philosophers and + +deadlock and so forth? + +Now let me tell you how +to deadlock Cilk++. + +So here's a code that +will deadlock + +Cilk++, or has the potential. + +You might run it a bunch of +times, it looks fine. + +Here's what we've done is +main routine spawns foo. + +Here's foo down here. + +All foo does is grab a lock +and then unlocks it. + +Empty critical section. + +It could do something +in there. + +It doesn't matter. + +Then the main grabs a lock, +does a cilk_sync and then + +unlocks it. + +So what can go wrong here? + +Notice, by the way, this +is only one lock, L. + +There's not two locks. + +So you can deadlock Cilk by +just introducing one lock. + +So here's sort of +what's going on. + +Let's let this be the main +thread and this be foo. + +And this will represent +a lock acquire, and + +this is a lock release. + +So what happens is we +perform the lock + +acquire here in the parent. + +First, we spawned here, then +we acquire the lock here. + +And now foo tries to get access +to the lock, and it + +can't because why? + +The main routine has the lock. + +Now what happens? + +The main routine proceeds to the +sync, and what does it do + +at the sync? + +It waits for all children +to be done. + +And notice now we've created a +cycle of waiting, even though + +we didn't use a lock. + +Main waits, but foo is never +going to complete, because + +it's waiting for the main thread +to release it, the main + +strand here to release it, +the main function here. + +Is that clear? + +So you can deadlock Cilk too +by doing non-deterministic + +programming. + +So here's the methodology that +will help you not do that. + +So what's bad here? + +What's bad is holding the +lock across the sync. + +That's bad. + +So don't do that. + +Doctor, my head hurts. + +Well, stop hitting it. + +So don't hold mutexes +across Cilk syncs. + +Hold mutexes only within +strands, only with + +serially-executing +pieces of code. + +Now, it turns out that you can +hold it across syncs and so + +forth, but you have +to be careful. + +And I'm not going to get +into the details of + +how you can do that. + +If you want to figure that out +on your own, that's fine. + +And then you're welcome +to try to do that + +without deadlocking something. + +Turns out, basically, if you +grab the lock before you do + +any spawns, and then released +it after the Cilk + +sync, you're OK. + +You're generally, in +that case, OK. + +So as always, try to avoid using +mutexes, but that's not + +always possible. + +In other words, try to do +deterministic programming. + +That helps too. + +And on your homework, you had an +example of where it is that + +deterministic programming can +actually do a pretty good job. + +The next anomaly I want to +talk about is convoying. + +Once again, another thing +that can happen. + +This one is actually quite an +embarrassment, because the + +original MIT Cilk system that +we built had this bug in it. + +So we had this bug. + +So let me show you what it is. + +So here's the idea. + +We're using random work-stealing +where each thief + +grabs a mutex on its +victim's deck. + +So in order to steal from a +victim, it grabs a mutex on + +the victim. + +And now, once it's got the +mutex, it now is in a position + +to migrate the work that's +on that victim to + +actually steal the work. + +And you want to do +that atomically. + +You don't want two guys getting +in there trying to + +steal from each other. + +So if the victim's deck is +empty, the thief releases the + +mutex and tries again +at random. + +That makes sense. + +If there's nothing there to be +stolen, then just released the + +mutex and move on. + +If the victim's deck contains +work, the thief then steals + +the topmost frame and then +releases the mutex. + +Where's the performance +bug here? + +AUDIENCE: [INAUDIBLE] + +trying to steal from +each other. + +Like A steals from B, B steals +from C, C steals from D, and + +they all have locks on each +other, and then-- + +PROFESSOR: No, because in that +case, they'll each grab the + +deck from each other, discover +it's empty, and release it. + +OK, let me show the bug. + +It is very subtle. + +As I say, we didn't realize we +had this bug until we noticed + +some codes on which we +weren't getting the + +speedups we were expecting. + +Let me show you where +this bug comes from. + +Here's the problem. + +At the startup, most thieves +will quickly converge on the + +worker P0 containing +the initial + +strand, creating a convoy. + +So let me show you +how that happens. + +So here we have the startup of +our Cilk system where one guy + +has work, and all these +are workers that + +have no work to do. + +So what happens? + +They all try to steal +at random. + +In this case, we have this guy +tries to steal from this + +fellow, this guy tries +to steal from + +this fellow, et cetera. + +So of these, this guy, this +guy, and that guy all are + +going to discover there's +nothing there to be stolen, + +and they're going to +repeat the process. + +This guy and this guy, there's +going to be some arbitration. + +And one of them is going +to get the lock. + +Let's assume it's +this one here. + +So what happens is, this +guy gets the lock. + +What does this guy do? + +He's going to wait. + +Because he's trying to +acquire the lock. + +He can't acquire the +lock, so he waits. + +So then what happens? + +This guy now wants to steal +the work from this fellow. + +So he steals a little +bit of work. + +Then these guys now, +what do they do? + +They try again. + +So this guy tries to steal from +there, this guy tries to + +steal from there, this one +happens to try to steal there. + +This one sees there's work +there to be done, so + +what does it do? + +It waits. + +But these guys then try again. + +Maybe a little bit more +stuff is moved. + +They try again. + +A little bit more stuff. + +They try again. + +But every time one tries and +gets stuck on P0 while we're + +doing that whole transfer, they +all are ending up getting + +stuck waiting for this +guy to finish. + +And now, we've got work over +here, but how many guys are + +going to be trying to +steal from this guy? + +None. + +They're all going to be trying +to steal from this one, + +because they all have done a +lock acquisition, and they're + +sitting there waiting. + +So this is called convoying, +where they all pile up on one + +thing, and now resolving +that convoy. + +So this was a bug in startup. + +Why wasn't Cilk starting +up fast? + +Initially, we just thought, oh, +there's system kinds of + +things going on there. + +So the work now gets distributed +very slowly, + +because each one is going to +serially try to get this work, + +and they're not going +to try to get the + +work from each other. + +What you want is that on the +second phase, half the guys + +might start hitting this one. + +So you get some kind of +exponential distribution of + +the work in kind of +a tree fashion. + +And that's what theory +says would happen. + +But the theory is usually done +without worrying about what + +happens in the implementation +of the lock. + +What's the fix for this? + +Yeah? + +AUDIENCE: Can you just basically +shove-- when you're + +transferring, you should also +say, I have work, so that + +people [INAUDIBLE] waiting for +that guy to [INAUDIBLE]. + +PROFESSOR: You could do that, +but in the meantime, it could + +be that the attempt to steal +goes so much faster than the + +actual getting of the work, +you're still going to get half + +the guys locked up +on this one. + +And the other half might be +locked up on this one. + +Good idea. + +What other things can we do? + +AUDIENCE: Can you check +how many people + +are waiting on the-- + +PROFESSOR: Yeah, so the +idea is we don't want + +to use a lock operation. + +So here's the idea. + +We use a non-blocking function +that's usually called + +"try_lock," rather than "lock." +try_lock attempts to + +acquire the mutex. + +If it succeeds, great. + +It's got it. + +If it fails, it doesn't +go to spin. + +It simply returns and +say, I failed. + +It doesn't go to spin or +to yield or anything. + +It just says, oh, I +failed, and tells + +that back to the user. + +But it doesn't attempt +to block. + +So with try_lock now, what can +these other processors do? + +They do a try_lock-- + +yeah? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Exactly. + +Instead of waiting there on +the guy that they fail on, + +they pick another random +one to steal from. + +So they'll just continually +try to get it. + +If they get it, then they +can do their operation. + +If they don't get it, they just +look elsewhere for work. + +So that's what it does. + +It just tries to steal again at + +random, rather than blocking. + +And that gets rid of this +convoying problem. + +As I say, dangerous programming, +because we didn't + +even know we had a problem. + +Just our code was slower than +it could have been. + +Questions about convoying? + +So try_lock is actually a very +convenient thing to use. + +So in many cases, you may find +that, hey, rather than waiting + +on something with nothing to do, +let me go see if there's + +something else I can +do in the meantime. + +Contention. + +So here's an example of a code +where I want to add up some + +function of the elements +of some array. + +So here I've got a value of +n, which is a million. + +And I have a type X. So we have +a compute function, which + +takes a pointer to a-- + +did I do this right? + +To value V. So anyway, my C++ +is not as good as my C, and + +for those who don't know, +my C isn't very good. + +So anyway, we have an array +of type X of n elements. + +And what I do is I set result +to be 0, and then I have a + +loop here which basically goes +and adds into result the + +result of computing on each +element of the array. + +And then it outputs +the result. + +Does everybody understand what's +going on in the code? + +It's basically compute on every +element in the array, + +take the result, add all +those results together. + +We want to parallelize this. + +So let's parallelize that. + +What looks like the best +opportunity for parallelizing? + +Yeah, we go after the for and +make it be a cilk_for. + +Let's add all those guys up. + +And what's the problem +with that? + +We get a race. + +What's the race on? + +AUDIENCE: Result. + +PROFESSOR: Result. + +They're all updating +result in parallel. + +Oh, I know how to +resolve a race. + +Let's just put a +lock around it. + +So here we have the race. + +First, let's analyze this. + +So the work here is order n. + +What is the span? + +AUDIENCE: Log n. + +PROFESSOR: Yeah, the span is log +n for the control of the + +stuff here, because this +is all constant time. + +So the running time here is +order n over P plus log n. + +If you remember the greedy +scheduling, it's going to be + +something like this, because +this is the work + +over P plus the span. + +So we expect that if n over P +is big compared to log n, + +we're going to do pretty well, +because we have parallelism + +over log n. + +So let's fix this bug. + +So this is fast code, but +it's incorrect code. + +So let's fix it by getting +rid of this race. + +So what we'll do is we'll +put a lock before. + +We'll introduce a mutex L, and +we'll lock L before we add to + +the result, and then +we'll unlock it. + +So first of all, this is a bad +way to do it, because what I + +really should do is first +compute the result of my array + +and then lock, add it to the +result, and then unlock so + +that we lessen the time +that I'm holding the + +lock in each iteration. + +Nevertheless, this is still +a lousy piece of code. + +Why's that? + +AUDIENCE: It's still +serialized. + +PROFESSOR: Yeah, it's +serialized. + +Every update to result here +has to go on serially. + +They're n accesses. + +They're all going to +go one at a time. + +So my running time, instead of +being n over log n, is going + +to be something like order n. + +Believe me, I have seen many +people write code where they + +essentially do exactly this. + +They take something, they make +it parallel, they have a race + +bug, they fix it with a mutex. + +Bad idea, because then +we end up with + +contention on this mutex. + +What's the right way to +parallelize this? + +Yeah? + +AUDIENCE: Maybe you could +have each [INAUDIBLE] + +have result as an array and +have each [INAUDIBLE] + +one place [INAUDIBLE]. + +And then at the end, +some of all the-- + +PROFESSOR: But won't that +be n elements to sum up? + +AUDIENCE: [INAUDIBLE] + +AUDIENCE: So basically, +have, say. + +Eight results, instead +of having-- + +PROFESSOR: For each thread. + +Good. + +So that each one could keep it +local to its own thread. + +Now, of course, that involves me +knowing how many processors + +I'm running on. + +So now, if that number +changes or whatever-- + +there's a way of doing it +completely processor + +obliviously. + +AUDIENCE: Divide and conquer. + +PROFESSOR: Yeah, do divide +and conquer. + +Add up recursively the first +half of the elements, add up + +the second half of +the elements, + +and add them together. + +Next time, we're going to see +yet another mechanism for + +doing that, which gets the +kind of performance that + +you're mentioning but without +having to rewrite the For loop + +as divide and conquer. + +We'll see that next time. + +So in this case, we have lock +contention that takes away our + +parallelism. + +Unfortunately, very little is +known about lock contention. + +The greedy scheduler, you can +show that it achieves T1 over + +P plus T infinity plus B where +B is the bondage, that is, if + +you add the total time of +all critical sections. + +That's a lousy bound, because +it says, even if they're + +locked by different locks, you +still add up the total time of + +all the critical sections. + +And generally, although you can +improve this in special + +cases, the general theory for +understanding contention is + +not understood very well. + +And this upper bound is weak, +but little is known about lock + +contention. + +Very little is known about +lock contention. + +So to conclude, always +write deterministic + +programs, unless you can't. + +Always write deterministic +programs, unless you can't. + +Great. \ No newline at end of file diff --git a/gzbWF-IdscE.txt b/gzbWF-IdscE.txt new file mode 100644 index 0000000000000000000000000000000000000000..26253aef2ede50b6ac3283b320fbbc7a8ec895b8 --- /dev/null +++ b/gzbWF-IdscE.txt @@ -0,0 +1,1419 @@ +align:start position:0% + +hello and welcome back to recitation in + + align:start position:0% +hello and welcome back to recitation in + + + align:start position:0% +hello and welcome back to recitation in +this question we're going to be + + align:start position:0% +this question we're going to be + + + align:start position:0% +this question we're going to be +considering a contour plot which is uh + + align:start position:0% +considering a contour plot which is uh + + + align:start position:0% +considering a contour plot which is uh +given to us as followed the values are + + align:start position:0% +given to us as followed the values are + + + align:start position:0% +given to us as followed the values are +not are not uh not + + align:start position:0% +not are not uh not + + + align:start position:0% +not are not uh not +indicated so the first thing that we + + align:start position:0% +indicated so the first thing that we + + + align:start position:0% +indicated so the first thing that we +want to do is uh we want to identify on + + align:start position:0% +want to do is uh we want to identify on + + + align:start position:0% +want to do is uh we want to identify on +this Contour plot there is a unique + + align:start position:0% +this Contour plot there is a unique + + + align:start position:0% +this Contour plot there is a unique +saddle point and we want to label that + + align:start position:0% +saddle point and we want to label that + + + align:start position:0% +saddle point and we want to label that +with uh as point a and there are two + + align:start position:0% +with uh as point a and there are two + + + align:start position:0% +with uh as point a and there are two +points which are either a maximum or a + + align:start position:0% +points which are either a maximum or a + + + align:start position:0% +points which are either a maximum or a +minimum we can't actually tell because + + align:start position:0% +minimum we can't actually tell because + + + align:start position:0% +minimum we can't actually tell because +the the the labels aren't on this + + align:start position:0% +the the the labels aren't on this + + + align:start position:0% +the the the labels aren't on this +Contour plot um but we want to go ahead + + align:start position:0% +Contour plot um but we want to go ahead + + + align:start position:0% +Contour plot um but we want to go ahead +and label those anyways B and C so + + align:start position:0% +and label those anyways B and C so + + + align:start position:0% +and label those anyways B and C so +they're either Maxima or Minima but we + + align:start position:0% +they're either Maxima or Minima but we + + + align:start position:0% +they're either Maxima or Minima but we +can still find them and we can still + + align:start position:0% +can still find them and we can still + + + align:start position:0% +can still find them and we can still +identify them so that's the first part + + align:start position:0% +identify them so that's the first part + + + align:start position:0% +identify them so that's the first part +of the problem the second part is uh + + align:start position:0% +of the problem the second part is uh + + + align:start position:0% +of the problem the second part is uh +since this doesn't have the values uh + + align:start position:0% +since this doesn't have the values uh + + + align:start position:0% +since this doesn't have the values uh +entered onto the graph we want to + + align:start position:0% +entered onto the graph we want to + + + align:start position:0% +entered onto the graph we want to +consider what possible uh configurations + + align:start position:0% +consider what possible uh configurations + + + align:start position:0% +consider what possible uh configurations +could we have so the second question is + + align:start position:0% +could we have so the second question is + + + align:start position:0% +could we have so the second question is +can + + align:start position:0% + + + + align:start position:0% + +B and + + align:start position:0% + + + + align:start position:0% + +C both be + + align:start position:0% + + + + align:start position:0% + +maximal + + align:start position:0% +maximal + + + align:start position:0% +maximal +and + + align:start position:0% +and + + + align:start position:0% +and +can we + + align:start position:0% + + + + align:start position:0% + +have B + + align:start position:0% +have B + + + align:start position:0% +have B +maximal but C + + align:start position:0% + + + + align:start position:0% + +minimal okay and then in each of these + + align:start position:0% +minimal okay and then in each of these + + + align:start position:0% +minimal okay and then in each of these +two cases we want to uh + + align:start position:0% + + + + align:start position:0% + +sketch the 3D + + align:start position:0% + + + + align:start position:0% + +graph so why don't you take some time to + + align:start position:0% +graph so why don't you take some time to + + + align:start position:0% +graph so why don't you take some time to +work this out pause the video and we'll + + align:start position:0% +work this out pause the video and we'll + + + align:start position:0% +work this out pause the video and we'll +check back and I'll show you how I solve + + align:start position:0% + + + + align:start position:0% + +this hello and welcome back so to get + + align:start position:0% +this hello and welcome back so to get + + + align:start position:0% +this hello and welcome back so to get +started why don't we answer the first + + align:start position:0% +started why don't we answer the first + + + align:start position:0% +started why don't we answer the first +question by writing the points right on + + align:start position:0% +question by writing the points right on + + + align:start position:0% +question by writing the points right on +our original graph so I'll just come + + align:start position:0% +our original graph so I'll just come + + + align:start position:0% +our original graph so I'll just come +over + + align:start position:0% + + + + align:start position:0% + +here now when we're looking for a + + align:start position:0% +here now when we're looking for a + + + align:start position:0% +here now when we're looking for a +minimum or a maximum on a contour plot + + align:start position:0% +minimum or a maximum on a contour plot + + + align:start position:0% +minimum or a maximum on a contour plot +uh you know the thing that we should + + align:start position:0% +uh you know the thing that we should + + + align:start position:0% +uh you know the thing that we should +keep in mind is that a Minima or a + + align:start position:0% +keep in mind is that a Minima or a + + + align:start position:0% +keep in mind is that a Minima or a +Maxima always is going to be contained + + align:start position:0% +Maxima always is going to be contained + + + align:start position:0% +Maxima always is going to be contained +in in concentric uh Contours that are + + align:start position:0% +in in concentric uh Contours that are + + + align:start position:0% +in in concentric uh Contours that are +either approaching the minimum From + + align:start position:0% +either approaching the minimum From + + + align:start position:0% +either approaching the minimum From +Below or uh excuse me approaching the + + align:start position:0% +Below or uh excuse me approaching the + + + align:start position:0% +Below or uh excuse me approaching the +maximum From Below or the minimum from + + align:start position:0% +maximum From Below or the minimum from + + + align:start position:0% +maximum From Below or the minimum from +above and so so if we look here uh we + + align:start position:0% +above and so so if we look here uh we + + + align:start position:0% +above and so so if we look here uh we +see that these these uh Rings start to + + align:start position:0% +see that these these uh Rings start to + + + align:start position:0% +see that these these uh Rings start to +become concentric and somewhere in here + + align:start position:0% +become concentric and somewhere in here + + + align:start position:0% +become concentric and somewhere in here +there's got to be either a maximum or a + + align:start position:0% +there's got to be either a maximum or a + + + align:start position:0% +there's got to be either a maximum or a +minimum because uh you know this uh + + align:start position:0% +minimum because uh you know this uh + + + align:start position:0% +minimum because uh you know this uh +inside this little uh inside this little + + align:start position:0% +inside this little uh inside this little + + + align:start position:0% +inside this little uh inside this little +region here the function uh doesn't pass + + align:start position:0% +region here the function uh doesn't pass + + + align:start position:0% +region here the function uh doesn't pass +through another Contour plot so we have + + align:start position:0% +through another Contour plot so we have + + + align:start position:0% +through another Contour plot so we have +to find either a maximum or a minimum + + align:start position:0% +to find either a maximum or a minimum + + + align:start position:0% +to find either a maximum or a minimum +inside the innermost ring and similarly + + align:start position:0% +inside the innermost ring and similarly + + + align:start position:0% +inside the innermost ring and similarly +we have to find either a minimum or a + + align:start position:0% +we have to find either a minimum or a + + + align:start position:0% +we have to find either a minimum or a +maximum here so let's just call this one + + align:start position:0% +maximum here so let's just call this one + + + align:start position:0% +maximum here so let's just call this one +b and this one + + align:start position:0% +b and this one + + + align:start position:0% +b and this one +C + + align:start position:0% +C + + + align:start position:0% +C +okay now uh we also have a saddle point + + align:start position:0% +okay now uh we also have a saddle point + + + align:start position:0% +okay now uh we also have a saddle point +a in this problem and uh it's a little + + align:start position:0% +a in this problem and uh it's a little + + + align:start position:0% +a in this problem and uh it's a little +bit hard to see in the Contour plot I + + align:start position:0% +bit hard to see in the Contour plot I + + + align:start position:0% +bit hard to see in the Contour plot I +think it'll be a little even clearer + + align:start position:0% +think it'll be a little even clearer + + + align:start position:0% +think it'll be a little even clearer +when we when we draw a 3D graph but + + align:start position:0% +when we when we draw a 3D graph but + + + align:start position:0% +when we when we draw a 3D graph but +basically what what's happening is the + + align:start position:0% +basically what what's happening is the + + + align:start position:0% +basically what what's happening is the +fact that you have these Contours so so + + align:start position:0% +fact that you have these Contours so so + + + align:start position:0% +fact that you have these Contours so so +this Contour is after all the same as + + align:start position:0% +this Contour is after all the same as + + + align:start position:0% +this Contour is after all the same as +that Contour so the value of the + + align:start position:0% +that Contour so the value of the + + + align:start position:0% +that Contour so the value of the +function here and here are the same uh + + align:start position:0% +function here and here are the same uh + + + align:start position:0% +function here and here are the same uh +and yet and yet uh if we look at this + + align:start position:0% +and yet and yet uh if we look at this + + + align:start position:0% +and yet and yet uh if we look at this +point and this point the values well + + align:start position:0% +point and this point the values well + + + align:start position:0% +point and this point the values well +they either go up or down we don't know + + align:start position:0% +they either go up or down we don't know + + + align:start position:0% +they either go up or down we don't know +let's assume that they go up uh so here + + align:start position:0% +let's assume that they go up uh so here + + + align:start position:0% +let's assume that they go up uh so here +in this direction the values are going + + align:start position:0% +in this direction the values are going + + + align:start position:0% +in this direction the values are going +up and in this direction uh uh the + + align:start position:0% +up and in this direction uh uh the + + + align:start position:0% +up and in this direction uh uh the +values are are determined by this + + align:start position:0% +values are are determined by this + + + align:start position:0% +values are are determined by this +Contour curve and so somewhere in this + + align:start position:0% +Contour curve and so somewhere in this + + + align:start position:0% +Contour curve and so somewhere in this +middle region here there's got to be a + + align:start position:0% +middle region here there's got to be a + + + align:start position:0% +middle region here there's got to be a +saddle point I think this will be even + + align:start position:0% +saddle point I think this will be even + + + align:start position:0% +saddle point I think this will be even +clearer when we draw a graph so we have + + align:start position:0% +clearer when we draw a graph so we have + + + align:start position:0% +clearer when we draw a graph so we have +a saddle point a in the middle there and + + align:start position:0% +a saddle point a in the middle there and + + + align:start position:0% +a saddle point a in the middle there and +and in fact this is really what this is + + align:start position:0% +and in fact this is really what this is + + + align:start position:0% +and in fact this is really what this is +the general picture of what a saddle + + align:start position:0% +the general picture of what a saddle + + + align:start position:0% +the general picture of what a saddle +point is going to look like it's going + + align:start position:0% +point is going to look like it's going + + + align:start position:0% +point is going to look like it's going +to be when you have sort of two either + + align:start position:0% +to be when you have sort of two either + + + align:start position:0% +to be when you have sort of two either +Maxima or Minima rising out and uh and + + align:start position:0% +Maxima or Minima rising out and uh and + + + align:start position:0% +Maxima or Minima rising out and uh and +you have uh you have a a contour which + + align:start position:0% +you have uh you have a a contour which + + + align:start position:0% +you have uh you have a a contour which +is uh which is containing the point in + + align:start position:0% +is uh which is containing the point in + + + align:start position:0% +is uh which is containing the point in +the middle so so those are our points a + + align:start position:0% +the middle so so those are our points a + + + align:start position:0% +the middle so so those are our points a +b and c that we're going to be + + align:start position:0% +b and c that we're going to be + + + align:start position:0% +b and c that we're going to be +interested in so now uh the second + + align:start position:0% +interested in so now uh the second + + + align:start position:0% +interested in so now uh the second +question that we have to consider is can + + align:start position:0% +question that we have to consider is can + + + align:start position:0% +question that we have to consider is can +B and C both be maximal and then the + + align:start position:0% +B and C both be maximal and then the + + + align:start position:0% +B and C both be maximal and then the +third question is can B uh be maximal + + align:start position:0% +third question is can B uh be maximal + + + align:start position:0% +third question is can B uh be maximal +and C minimal and actually we'll answer + + align:start position:0% +and C minimal and actually we'll answer + + + align:start position:0% +and C minimal and actually we'll answer +both of these questions by just + + align:start position:0% +both of these questions by just + + + align:start position:0% +both of these questions by just +sketching an example so that's how we'll + + align:start position:0% +sketching an example so that's how we'll + + + align:start position:0% +sketching an example so that's how we'll +That's How we'll understand this so why + + align:start position:0% +That's How we'll understand this so why + + + align:start position:0% +That's How we'll understand this so why +don't we see if we can sketch an example + + align:start position:0% +don't we see if we can sketch an example + + + align:start position:0% +don't we see if we can sketch an example +uh where B and C are both + + align:start position:0% + + + + align:start position:0% + +maximal so + + align:start position:0% + + + + align:start position:0% + +so here's my uh here's here's the start + + align:start position:0% +so here's my uh here's here's the start + + + align:start position:0% +so here's my uh here's here's the start +of my graph in three dimensions and and + + align:start position:0% +of my graph in three dimensions and and + + + align:start position:0% +of my graph in three dimensions and and +if we want B and C to both be maximal + + align:start position:0% +if we want B and C to both be maximal + + + align:start position:0% +if we want B and C to both be maximal +then let me go ahead and draw the um the + + align:start position:0% +then let me go ahead and draw the um the + + + align:start position:0% +then let me go ahead and draw the um the +contour lines that we have so we have uh + + align:start position:0% +contour lines that we have so we have uh + + + align:start position:0% +contour lines that we have so we have uh +first of all we had this + + align:start position:0% +first of all we had this + + + align:start position:0% +first of all we had this +one and then we had another one and then + + align:start position:0% +one and then we had another one and then + + + align:start position:0% +one and then we had another one and then +we had a peak and then we had a peak so + + align:start position:0% +we had a peak and then we had a peak so + + + align:start position:0% +we had a peak and then we had a peak so +if we want to draw this uh in in three + + align:start position:0% +if we want to draw this uh in in three + + + align:start position:0% +if we want to draw this uh in in three +dimensions then what we just need to do + + align:start position:0% +dimensions then what we just need to do + + + align:start position:0% +dimensions then what we just need to do +is we just need to follow these Contour + + align:start position:0% +is we just need to follow these Contour + + + align:start position:0% +is we just need to follow these Contour +plots up uh out of out of the plane and + + align:start position:0% +plots up uh out of out of the plane and + + + align:start position:0% +plots up uh out of out of the plane and +into space so this goes up and then + + align:start position:0% +into space so this goes up and then + + + align:start position:0% +into space so this goes up and then +there's a maximum and then it comes back + + align:start position:0% +there's a maximum and then it comes back + + + align:start position:0% +there's a maximum and then it comes back +down along the contour lines and then it + + align:start position:0% +down along the contour lines and then it + + + align:start position:0% +down along the contour lines and then it +goes back up and then it goes back + + align:start position:0% +goes back up and then it goes back + + + align:start position:0% +goes back up and then it goes back +down so that's just uh one of the curves + + align:start position:0% +down so that's just uh one of the curves + + + align:start position:0% +down so that's just uh one of the curves +that lies on the on the graph of the + + align:start position:0% +that lies on the on the graph of the + + + align:start position:0% +that lies on the on the graph of the +function uh but then we need to uh flush + + align:start position:0% +function uh but then we need to uh flush + + + align:start position:0% +function uh but then we need to uh flush +out the contour lines which they look + + align:start position:0% +out the contour lines which they look + + + align:start position:0% +out the contour lines which they look +like these sort of rings here + + align:start position:0% + + + + align:start position:0% + +okay and so indeed we do see that uh + + align:start position:0% +okay and so indeed we do see that uh + + + align:start position:0% +okay and so indeed we do see that uh +it's possible for both B and C to be a + + align:start position:0% +it's possible for both B and C to be a + + + align:start position:0% +it's possible for both B and C to be a +maximal here's an example of such a + + align:start position:0% +maximal here's an example of such a + + + align:start position:0% +maximal here's an example of such a +thing and uh and so here's our point B + + align:start position:0% +thing and uh and so here's our point B + + + align:start position:0% +thing and uh and so here's our point B +here's our Point + + align:start position:0% +here's our Point + + + align:start position:0% +here's our Point +C and as promised I think it's much + + align:start position:0% +C and as promised I think it's much + + + align:start position:0% +C and as promised I think it's much +clearer now how how a becomes a saddle + + align:start position:0% +clearer now how how a becomes a saddle + + + align:start position:0% +clearer now how how a becomes a saddle +point because you have these two + + align:start position:0% +point because you have these two + + + align:start position:0% +point because you have these two +mountains rising up and the valley in + + align:start position:0% +mountains rising up and the valley in + + + align:start position:0% +mountains rising up and the valley in +between them is necessarily a little + + align:start position:0% +between them is necessarily a little + + + align:start position:0% +between them is necessarily a little +saddle here it's a it h it increases in + + align:start position:0% +saddle here it's a it h it increases in + + + align:start position:0% +saddle here it's a it h it increases in +this direction and it decreases in this + + align:start position:0% +this direction and it decreases in this + + + align:start position:0% +this direction and it decreases in this +Direction now uh for the second one we + + align:start position:0% +Direction now uh for the second one we + + + align:start position:0% +Direction now uh for the second one we +asked can uh B Be maximal and yet C be + + align:start position:0% +asked can uh B Be maximal and yet C be + + + align:start position:0% +asked can uh B Be maximal and yet C be +minimal and the answer is still yes and + + align:start position:0% +minimal and the answer is still yes and + + + align:start position:0% +minimal and the answer is still yes and +uh a nice way to think about this + + align:start position:0% +uh a nice way to think about this + + + align:start position:0% +uh a nice way to think about this +problem to think about the graph that + + align:start position:0% +problem to think about the graph that + + + align:start position:0% +problem to think about the graph that +I'm going to draw is imagine that we + + align:start position:0% +I'm going to draw is imagine that we + + + align:start position:0% +I'm going to draw is imagine that we +start over here and we dig a hole and as + + align:start position:0% +start over here and we dig a hole and as + + + align:start position:0% +start over here and we dig a hole and as +we're digging we throw the dirt over + + align:start position:0% +we're digging we throw the dirt over + + + align:start position:0% +we're digging we throw the dirt over +behind us so we're going to have a + + align:start position:0% + + + + align:start position:0% + +hole a dip here and then we're going to + + align:start position:0% +hole a dip here and then we're going to + + + align:start position:0% +hole a dip here and then we're going to +pile that hole up over + + align:start position:0% +pile that hole up over + + + align:start position:0% +pile that hole up over +here and so + + align:start position:0% + + + + align:start position:0% + +then now notice that that both of these + + align:start position:0% +then now notice that that both of these + + + align:start position:0% +then now notice that that both of these +that I've drawn if we don't if we don't + + align:start position:0% +that I've drawn if we don't if we don't + + + align:start position:0% +that I've drawn if we don't if we don't +label the contour lines these have the + + align:start position:0% +label the contour lines these have the + + + align:start position:0% +label the contour lines these have the +same Contour plot because the concentric + + align:start position:0% +same Contour plot because the concentric + + + align:start position:0% +same Contour plot because the concentric +rings on C which are telling us that the + + align:start position:0% +rings on C which are telling us that the + + + align:start position:0% +rings on C which are telling us that the +function is increased ining uh they're + + align:start position:0% +function is increased ining uh they're + + + align:start position:0% +function is increased ining uh they're +the same uh + + align:start position:0% +the same uh + + + align:start position:0% +the same uh +below uh because this is essentially the + + align:start position:0% +below uh because this is essentially the + + + align:start position:0% +below uh because this is essentially the +same thing uh the concentric rings that + + align:start position:0% +same thing uh the concentric rings that + + + align:start position:0% +same thing uh the concentric rings that +on this curve on this surface we telling + + align:start position:0% +on this curve on this surface we telling + + + align:start position:0% +on this curve on this surface we telling +us that uh that b was a maximum point + + align:start position:0% +us that uh that b was a maximum point + + + align:start position:0% +us that uh that b was a maximum point +now the same rings are telling us that b + + align:start position:0% +now the same rings are telling us that b + + + align:start position:0% +now the same rings are telling us that b +is a minimal point so this illustrates + + align:start position:0% +is a minimal point so this illustrates + + + align:start position:0% +is a minimal point so this illustrates +that a contour plot is is really doesn't + + align:start position:0% +that a contour plot is is really doesn't + + + align:start position:0% +that a contour plot is is really doesn't +tell you everything about the graph + + align:start position:0% +tell you everything about the graph + + + align:start position:0% +tell you everything about the graph +unless you actually uh label the the + + align:start position:0% +unless you actually uh label the the + + + align:start position:0% +unless you actually uh label the the +values of the + + align:start position:0% +values of the + + + align:start position:0% +values of the +Contours so uh so here we see two two + + align:start position:0% +Contours so uh so here we see two two + + + align:start position:0% +Contours so uh so here we see two two +examples uh where um where the the sort + + align:start position:0% +examples uh where um where the the sort + + + align:start position:0% +examples uh where um where the the sort +of global behavior and B andc are are + + align:start position:0% +of global behavior and B andc are are + + + align:start position:0% +of global behavior and B andc are are +very different even though they have the + + align:start position:0% +very different even though they have the + + + align:start position:0% +very different even though they have the +same Contour plot now notice in both + + align:start position:0% +same Contour plot now notice in both + + + align:start position:0% +same Contour plot now notice in both +cases a is a is a saddle point uh it's + + align:start position:0% +cases a is a is a saddle point uh it's + + + align:start position:0% +cases a is a is a saddle point uh it's +increasing in the it's increasing in in + + align:start position:0% +increasing in the it's increasing in in + + + align:start position:0% +increasing in the it's increasing in in +One Direction and and decreasing in the + + align:start position:0% +One Direction and and decreasing in the + + + align:start position:0% +One Direction and and decreasing in the +other and I think I'll leave it at that \ No newline at end of file diff --git a/h25xARj3lb8.txt b/h25xARj3lb8.txt new file mode 100644 index 0000000000000000000000000000000000000000..43c2bb9e18c4ee4a03d175232b780cfa9ef30d72 --- /dev/null +++ b/h25xARj3lb8.txt @@ -0,0 +1,827 @@ +align:start position:0% + +after your exercise in translation + + align:start position:0% +after your exercise in translation + + + align:start position:0% +after your exercise in translation +you should be able to look at genetic + + align:start position:0% +you should be able to look at genetic + + + align:start position:0% +you should be able to look at genetic +code tables and go from the messenger + + align:start position:0% +code tables and go from the messenger + + + align:start position:0% +code tables and go from the messenger +rna to the corresponding amino acid + + align:start position:0% +rna to the corresponding amino acid + + + align:start position:0% +rna to the corresponding amino acid +you should understand the concept of a + + align:start position:0% +you should understand the concept of a + + + align:start position:0% +you should understand the concept of a +codon and an anticodon + + align:start position:0% +codon and an anticodon + + + align:start position:0% +codon and an anticodon +and you should be able to take a piece + + align:start position:0% +and you should be able to take a piece + + + align:start position:0% +and you should be able to take a piece +of rna + + align:start position:0% +of rna + + + align:start position:0% +of rna +and translate it conceptually into + + align:start position:0% +and translate it conceptually into + + + align:start position:0% +and translate it conceptually into +protein + + align:start position:0% +protein + + + align:start position:0% +protein +you should also know the direction of + + align:start position:0% +you should also know the direction of + + + align:start position:0% +you should also know the direction of +protein synthesis + + align:start position:0% +protein synthesis + + + align:start position:0% +protein synthesis +that we discussed before but it should + + align:start position:0% +that we discussed before but it should + + + align:start position:0% +that we discussed before but it should +now be very clear + + align:start position:0% +now be very clear + + + align:start position:0% +now be very clear +in your mind + + align:start position:0% + + + + align:start position:0% + +so what we've done today is to take + + align:start position:0% +so what we've done today is to take + + + align:start position:0% +so what we've done today is to take +dna we've discussed how it is precisely + + align:start position:0% +dna we've discussed how it is precisely + + + align:start position:0% +dna we've discussed how it is precisely +replicated + + align:start position:0% +replicated + + + align:start position:0% +replicated +using the rules of nucleic acid + + align:start position:0% +using the rules of nucleic acid + + + align:start position:0% +using the rules of nucleic acid +three prime end addition complementarity + + align:start position:0% +three prime end addition complementarity + + + align:start position:0% +three prime end addition complementarity +anti-parallelism we've talked about + + align:start position:0% +anti-parallelism we've talked about + + + align:start position:0% +anti-parallelism we've talked about +how dna is turned into rna + + align:start position:0% +how dna is turned into rna + + + align:start position:0% +how dna is turned into rna +by transcription and we've talked about + + align:start position:0% +by transcription and we've talked about + + + align:start position:0% +by transcription and we've talked about +how rna + + align:start position:0% +how rna + + + align:start position:0% +how rna +is then turned into the completely + + align:start position:0% +is then turned into the completely + + + align:start position:0% +is then turned into the completely +different language + + align:start position:0% +different language + + + align:start position:0% +different language +of protein we care about this deeply + + align:start position:0% +of protein we care about this deeply + + + align:start position:0% +of protein we care about this deeply +because the proteins and sometimes + + align:start position:0% +because the proteins and sometimes + + + align:start position:0% +because the proteins and sometimes +the rnas are final products + + align:start position:0% +the rnas are final products + + + align:start position:0% +the rnas are final products +of genes they are what makes the cell + + align:start position:0% +of genes they are what makes the cell + + + align:start position:0% +of genes they are what makes the cell +work + + align:start position:0% +work + + + align:start position:0% +work +they are met what makes the organs of + + align:start position:0% +they are met what makes the organs of + + + align:start position:0% +they are met what makes the organs of +the body work + + align:start position:0% +the body work + + + align:start position:0% +the body work +they are what makes you and me work + + align:start position:0% +they are what makes you and me work + + + align:start position:0% +they are what makes you and me work +so the final products + + align:start position:0% +so the final products + + + align:start position:0% +so the final products +are essential for life + + align:start position:0% +are essential for life + + + align:start position:0% +are essential for life +or very useful for life that is why + + align:start position:0% +or very useful for life that is why + + + align:start position:0% +or very useful for life that is why +we care about this whole information + + align:start position:0% +we care about this whole information + + + align:start position:0% +we care about this whole information +transfer + + align:start position:0% +transfer + + + align:start position:0% +transfer +let's end off today's discussion + + align:start position:0% +let's end off today's discussion + + + align:start position:0% +let's end off today's discussion +by going through one more example from + + align:start position:0% +by going through one more example from + + + align:start position:0% +by going through one more example from +gene to protein let's start off + + align:start position:0% +gene to protein let's start off + + + align:start position:0% +gene to protein let's start off +with a piece of double-stranded dna + + align:start position:0% +with a piece of double-stranded dna + + + align:start position:0% +with a piece of double-stranded dna +five prime atg + + align:start position:0% +five prime atg + + + align:start position:0% +five prime atg +g a a g + + align:start position:0% +g a a g + + + align:start position:0% +g a a g +c t just checking my notes here + + align:start position:0% +c t just checking my notes here + + + align:start position:0% +c t just checking my notes here +the complementary strand you now know do + + align:start position:0% +the complementary strand you now know do + + + align:start position:0% +the complementary strand you now know do +it with me + + align:start position:0% +it with me + + + align:start position:0% +it with me +t a c c t t + + align:start position:0% +t a c c t t + + + align:start position:0% +t a c c t t +c g a five + + align:start position:0% +c g a five + + + align:start position:0% +c g a five +prime if we make this bottom strand + + align:start position:0% +prime if we make this bottom strand + + + align:start position:0% +prime if we make this bottom strand +the template strand but as you know i + + align:start position:0% +the template strand but as you know i + + + align:start position:0% +the template strand but as you know i +could have made the top strand the + + align:start position:0% +could have made the top strand the + + + align:start position:0% +could have made the top strand the +template strand it's just a matter of + + align:start position:0% +template strand it's just a matter of + + + align:start position:0% +template strand it's just a matter of +convenience that i've done it this way + + align:start position:0% +convenience that i've done it this way + + + align:start position:0% +convenience that i've done it this way +the rna + + align:start position:0% +the rna + + + align:start position:0% +the rna +that comes out will be the complement + + align:start position:0% +that comes out will be the complement + + + align:start position:0% +that comes out will be the complement +of this template dna strand + + align:start position:0% +of this template dna strand + + + align:start position:0% +of this template dna strand +it will be a u g g + + align:start position:0% +it will be a u g g + + + align:start position:0% +it will be a u g g +a a g c + + align:start position:0% +a a g c + + + align:start position:0% +a a g c +u there's a little trick here i want to + + align:start position:0% +u there's a little trick here i want to + + + align:start position:0% +u there's a little trick here i want to +tell you + + align:start position:0% +tell you + + + align:start position:0% +tell you +the sequence of the rna is actually the + + align:start position:0% +the sequence of the rna is actually the + + + align:start position:0% +the sequence of the rna is actually the +same as the non-template + + align:start position:0% +same as the non-template + + + align:start position:0% +same as the non-template +the strand sequence and if you ever need + + align:start position:0% +the strand sequence and if you ever need + + + align:start position:0% +the strand sequence and if you ever need +that on a problem set + + align:start position:0% +that on a problem set + + + align:start position:0% +that on a problem set +or in some other reason you should + + align:start position:0% +or in some other reason you should + + + align:start position:0% +or in some other reason you should +remember that + + align:start position:0% +remember that + + + align:start position:0% +remember that +so the rna looks like + + align:start position:0% +so the rna looks like + + + align:start position:0% +so the rna looks like +the non-template strand except that + + align:start position:0% +the non-template strand except that + + + align:start position:0% +the non-template strand except that +there are u's + + align:start position:0% +there are u's + + + align:start position:0% +there are u's +instead of ts okay + + align:start position:0% +instead of ts okay + + + align:start position:0% +instead of ts okay +and now we can take this rna and we can + + align:start position:0% +and now we can take this rna and we can + + + align:start position:0% +and now we can take this rna and we can +divide it into codons + + align:start position:0% +divide it into codons + + + align:start position:0% +divide it into codons +and we can translate it aug + + align:start position:0% +and we can translate it aug + + + align:start position:0% +and we can translate it aug +gaa g cu + + align:start position:0% +gaa g cu + + + align:start position:0% +gaa g cu +and the protein that will come out of + + align:start position:0% +and the protein that will come out of + + + align:start position:0% +and the protein that will come out of +this translation + + align:start position:0% +this translation + + + align:start position:0% +this translation +methionine lysine threonine + + align:start position:0% +methionine lysine threonine + + + align:start position:0% +methionine lysine threonine +and these are covalently joined together + + align:start position:0% +and these are covalently joined together + + + align:start position:0% +and these are covalently joined together +the direction of the strand of protein + + align:start position:0% +the direction of the strand of protein + + + align:start position:0% +the direction of the strand of protein +from amino to carboxy end this + + align:start position:0% +from amino to carboxy end this + + + align:start position:0% +from amino to carboxy end this +is what you should know by this point + + align:start position:0% +is what you should know by this point + + + align:start position:0% +is what you should know by this point +and you should know the various rules by + + align:start position:0% +and you should know the various rules by + + + align:start position:0% +and you should know the various rules by +which + + align:start position:0% +which + + + align:start position:0% +which +these different aspects of information + + align:start position:0% +these different aspects of information + + + align:start position:0% +these different aspects of information +transfer + + align:start position:0% +transfer + + + align:start position:0% +transfer +in biology work so to summarize what + + align:start position:0% +in biology work so to summarize what + + + align:start position:0% +in biology work so to summarize what +we've talked about + + align:start position:0% +we've talked about + + + align:start position:0% +we've talked about +today we've talked about the gene + + align:start position:0% +today we've talked about the gene + + + align:start position:0% +today we've talked about the gene +and dna rules we've talked about dna + + align:start position:0% +and dna rules we've talked about dna + + + align:start position:0% +and dna rules we've talked about dna +replication + + align:start position:0% +replication + + + align:start position:0% +replication +and transcription and then we culminated + + align:start position:0% +and transcription and then we culminated + + + align:start position:0% +and transcription and then we culminated +this all + + align:start position:0% +this all + + + align:start position:0% +this all +with a discussion of translation you're + + align:start position:0% +with a discussion of translation you're + + + align:start position:0% +with a discussion of translation you're +well on your way now + + align:start position:0% +well on your way now + + + align:start position:0% +well on your way now +to understanding some of the basics in + + align:start position:0% +to understanding some of the basics in + + + align:start position:0% +to understanding some of the basics in +biology + + align:start position:0% +biology + + + align:start position:0% +biology +and to start to understand how you can + + align:start position:0% +and to start to understand how you can + + + align:start position:0% +and to start to understand how you can +figure out which gene does what + + align:start position:0% +figure out which gene does what + + + align:start position:0% +figure out which gene does what +and when genes are abnormal or mutated + + align:start position:0% +and when genes are abnormal or mutated + + + align:start position:0% +and when genes are abnormal or mutated +what the outcomes are going to be and + + align:start position:0% +what the outcomes are going to be and + + + align:start position:0% +what the outcomes are going to be and +we'll talk about that kind of thing + + align:start position:0% +we'll talk about that kind of thing + + + align:start position:0% +we'll talk about that kind of thing +next time \ No newline at end of file diff --git a/hov6w7QFjBY.txt b/hov6w7QFjBY.txt new file mode 100644 index 0000000000000000000000000000000000000000..2951af075009d8a8dee559638ecffcdb7d4c6db0 --- /dev/null +++ b/hov6w7QFjBY.txt @@ -0,0 +1,13067 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT open courseware + + align:start position:0% +of MIT courses visit MIT open courseware + + + align:start position:0% +of MIT courses visit MIT open courseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu good morning this is uh + + align:start position:0% +ocw.mit.edu good morning this is uh + + + align:start position:0% +ocw.mit.edu good morning this is uh +lecture number two of the operational + + align:start position:0% +lecture number two of the operational + + + align:start position:0% +lecture number two of the operational +reactor safety course I am Professor + + align:start position:0% +reactor safety course I am Professor + + + align:start position:0% +reactor safety course I am Professor +Andrew kak as you probably already know + + align:start position:0% +Andrew kak as you probably already know + + + align:start position:0% +Andrew kak as you probably already know +by now and today we're going to talk + + align:start position:0% +by now and today we're going to talk + + + align:start position:0% +by now and today we're going to talk +about uh a review of reactive physics + + align:start position:0% +about uh a review of reactive physics + + + align:start position:0% +about uh a review of reactive physics +now once again as I want to repeat uh + + align:start position:0% +now once again as I want to repeat uh + + + align:start position:0% +now once again as I want to repeat uh +we're assuming that you've taken + + align:start position:0% +we're assuming that you've taken + + + align:start position:0% +we're assuming that you've taken +fundamental reactor Physics course and + + align:start position:0% +fundamental reactor Physics course and + + + align:start position:0% +fundamental reactor Physics course and +that what we're going to talk about here + + align:start position:0% +that what we're going to talk about here + + + align:start position:0% +that what we're going to talk about here +very fast in essentially one lecture is + + align:start position:0% +very fast in essentially one lecture is + + + align:start position:0% +very fast in essentially one lecture is +a review so that we're all rough roughly + + align:start position:0% +a review so that we're all rough roughly + + + align:start position:0% +a review so that we're all rough roughly +on the same page as we go forward in the + + align:start position:0% +on the same page as we go forward in the + + + align:start position:0% +on the same page as we go forward in the +uh in this course now we're going to + + align:start position:0% +uh in this course now we're going to + + + align:start position:0% +uh in this course now we're going to +cover in this lecture are some Basics + + align:start position:0% +cover in this lecture are some Basics + + + align:start position:0% +cover in this lecture are some Basics +such as cross-sections the the + + align:start position:0% +such as cross-sections the the + + + align:start position:0% +such as cross-sections the the +fundamentals of the fision process we're + + align:start position:0% +fundamentals of the fision process we're + + + align:start position:0% +fundamentals of the fision process we're +going to look at both infinite reactor + + align:start position:0% +going to look at both infinite reactor + + + align:start position:0% +going to look at both infinite reactor +systems and finite reactor systems to + + align:start position:0% +systems and finite reactor systems to + + + align:start position:0% +systems and finite reactor systems to +identify the differences certainly in + + align:start position:0% +identify the differences certainly in + + + align:start position:0% +identify the differences certainly in +analysis we're going to look at the four + + align:start position:0% +analysis we're going to look at the four + + + align:start position:0% +analysis we're going to look at the four +Factor formula and the six Factor + + align:start position:0% +Factor formula and the six Factor + + + align:start position:0% +Factor formula and the six Factor +formula which is the formula for + + align:start position:0% +formula which is the formula for + + + align:start position:0% +formula which is the formula for +criticality we're going to assess How We + + align:start position:0% +criticality we're going to assess How We + + + align:start position:0% +criticality we're going to assess How We +Do control criticality in terms of + + align:start position:0% +Do control criticality in terms of + + + align:start position:0% +Do control criticality in terms of +control rods and other uh Neutron + + align:start position:0% +control rods and other uh Neutron + + + align:start position:0% +control rods and other uh Neutron +absorbers we'll begin and introduce you + + align:start position:0% +absorbers we'll begin and introduce you + + + align:start position:0% +absorbers we'll begin and introduce you +and remind you about diffusion Theory + + align:start position:0% +and remind you about diffusion Theory + + + align:start position:0% +and remind you about diffusion Theory +and we'll conclude with the neutron + + align:start position:0% +and we'll conclude with the neutron + + + align:start position:0% +and we'll conclude with the neutron +transport equation which we formerly + + align:start position:0% +transport equation which we formerly + + + align:start position:0% +transport equation which we formerly +have called the boltzman equation so + + align:start position:0% +have called the boltzman equation so + + + align:start position:0% +have called the boltzman equation so +it's going to be quite a lot of material + + align:start position:0% +it's going to be quite a lot of material + + + align:start position:0% +it's going to be quite a lot of material +it's going to go relatively fast but + + align:start position:0% +it's going to go relatively fast but + + + align:start position:0% +it's going to go relatively fast but +having taken the course you should be + + align:start position:0% +having taken the course you should be + + + align:start position:0% +having taken the course you should be +fine with + + align:start position:0% +fine with + + + align:start position:0% +fine with +it now first of all we're going to talk + + align:start position:0% +it now first of all we're going to talk + + + align:start position:0% +it now first of all we're going to talk +about the fundamentals of the + + align:start position:0% +about the fundamentals of the + + + align:start position:0% +about the fundamentals of the +um Neutron capture and what happens in + + align:start position:0% +um Neutron capture and what happens in + + + align:start position:0% +um Neutron capture and what happens in +the neutron capture of uranium 235 at + + align:start position:0% +the neutron capture of uranium 235 at + + + align:start position:0% +the neutron capture of uranium 235 at +having been struck by a neutron you have + + align:start position:0% +having been struck by a neutron you have + + + align:start position:0% +having been struck by a neutron you have +essentially an unstable uranium 236 Nui + + align:start position:0% +essentially an unstable uranium 236 Nui + + + align:start position:0% +essentially an unstable uranium 236 Nui +which can have certain things occur and + + align:start position:0% +which can have certain things occur and + + + align:start position:0% +which can have certain things occur and +each one of these things occurs with a + + align:start position:0% +each one of these things occurs with a + + + align:start position:0% +each one of these things occurs with a +certain probability and the + + align:start position:0% +certain probability and the + + + align:start position:0% +certain probability and the +probabilities are essentially expressed + + align:start position:0% +probabilities are essentially expressed + + + align:start position:0% +probabilities are essentially expressed +in terms of cross-sections or barns now + + align:start position:0% +in terms of cross-sections or barns now + + + align:start position:0% +in terms of cross-sections or barns now +you can have an elastic scattering + + align:start position:0% +you can have an elastic scattering + + + align:start position:0% +you can have an elastic scattering +Collision where the neutron in fact just + + align:start position:0% +Collision where the neutron in fact just + + + align:start position:0% +Collision where the neutron in fact just +essentially bounces off the uranium 235 + + align:start position:0% +essentially bounces off the uranium 235 + + + align:start position:0% +essentially bounces off the uranium 235 +atom and and just continues on as Pro + + align:start position:0% +atom and and just continues on as Pro + + + align:start position:0% +atom and and just continues on as Pro +possibly slowed down just ever so + + align:start position:0% +possibly slowed down just ever so + + + align:start position:0% +possibly slowed down just ever so +slightly you can have inelastic + + align:start position:0% +slightly you can have inelastic + + + align:start position:0% +slightly you can have inelastic +scattering when you when you can create + + align:start position:0% +scattering when you when you can create + + + align:start position:0% +scattering when you when you can create +a neutron that's slightly captured and + + align:start position:0% +a neutron that's slightly captured and + + + align:start position:0% +a neutron that's slightly captured and +then essentially initially emitted you + + align:start position:0% +then essentially initially emitted you + + + align:start position:0% +then essentially initially emitted you +can capture a neutron and create uranium + + align:start position:0% +can capture a neutron and create uranium + + + align:start position:0% +can capture a neutron and create uranium +236 with the release of some gamma + + align:start position:0% +236 with the release of some gamma + + + align:start position:0% +236 with the release of some gamma +energy or you can have multiple Neutron + + align:start position:0% +energy or you can have multiple Neutron + + + align:start position:0% +energy or you can have multiple Neutron +emissions and captures where you can + + align:start position:0% +emissions and captures where you can + + + align:start position:0% +emissions and captures where you can +emit two neutrons resulting in uranium + + align:start position:0% +emit two neutrons resulting in uranium + + + align:start position:0% +emit two neutrons resulting in uranium +234 or lastly and the thing that we're + + align:start position:0% +234 or lastly and the thing that we're + + + align:start position:0% +234 or lastly and the thing that we're +most interested in is the fision process + + align:start position:0% +most interested in is the fision process + + + align:start position:0% +most interested in is the fision process +and in the visioning these are the + + align:start position:0% +and in the visioning these are the + + + align:start position:0% +and in the visioning these are the +things that that we have to understand + + align:start position:0% +things that that we have to understand + + + align:start position:0% +things that that we have to understand +might occur in the uranium atom when a + + align:start position:0% +might occur in the uranium atom when a + + + align:start position:0% +might occur in the uranium atom when a +neutron is is in fact when Neutron + + align:start position:0% +neutron is is in fact when Neutron + + + align:start position:0% +neutron is is in fact when Neutron +strikes uranium + + align:start position:0% +strikes uranium + + + align:start position:0% +strikes uranium +235 now the concept of + + align:start position:0% +235 now the concept of + + + align:start position:0% +235 now the concept of +cross-sections is is a very important + + align:start position:0% +cross-sections is is a very important + + + align:start position:0% +cross-sections is is a very important +Concept in nuclear reactor physics you + + align:start position:0% +Concept in nuclear reactor physics you + + + align:start position:0% +Concept in nuclear reactor physics you +have what we call a total cross-section + + align:start position:0% +have what we call a total cross-section + + + align:start position:0% +have what we call a total cross-section +which is the total probabilities of + + align:start position:0% +which is the total probabilities of + + + align:start position:0% +which is the total probabilities of +either scattering or absorption these + + align:start position:0% +either scattering or absorption these + + + align:start position:0% +either scattering or absorption these +are the two phenomenon that we're + + align:start position:0% +are the two phenomenon that we're + + + align:start position:0% +are the two phenomenon that we're +talking about and if you scatter you can + + align:start position:0% +talking about and if you scatter you can + + + align:start position:0% +talking about and if you scatter you can +have an elastic scattering cross-section + + align:start position:0% +have an elastic scattering cross-section + + + align:start position:0% +have an elastic scattering cross-section +or an inelastic scattering cross-section + + align:start position:0% +or an inelastic scattering cross-section + + + align:start position:0% +or an inelastic scattering cross-section +which are combined to the fundamental + + align:start position:0% +which are combined to the fundamental + + + align:start position:0% +which are combined to the fundamental +scattering or you can have an absorption + + align:start position:0% +scattering or you can have an absorption + + + align:start position:0% +scattering or you can have an absorption +going on where you can just capture it + + align:start position:0% +going on where you can just capture it + + + align:start position:0% +going on where you can just capture it +and you can have all of these functions + + align:start position:0% +and you can have all of these functions + + + align:start position:0% +and you can have all of these functions +that occur where you have various you + + align:start position:0% +that occur where you have various you + + + align:start position:0% +that occur where you have various you +have radiative capture we talked about + + align:start position:0% +have radiative capture we talked about + + + align:start position:0% +have radiative capture we talked about +we talked about charged particle Neutron + + align:start position:0% +we talked about charged particle Neutron + + + align:start position:0% +we talked about charged particle Neutron +and multiple Neutron emissions and each + + align:start position:0% +and multiple Neutron emissions and each + + + align:start position:0% +and multiple Neutron emissions and each +one of these has a certain probability + + align:start position:0% +one of these has a certain probability + + + align:start position:0% +one of these has a certain probability +of occurrence which is expressed in its + + align:start position:0% +of occurrence which is expressed in its + + + align:start position:0% +of occurrence which is expressed in its +own cross-section and then of course as + + align:start position:0% +own cross-section and then of course as + + + align:start position:0% +own cross-section and then of course as +part of the absorption we have a fision + + align:start position:0% +part of the absorption we have a fision + + + align:start position:0% +part of the absorption we have a fision +crosssection + + align:start position:0% +crosssection + + + align:start position:0% +crosssection +which as I said earlier is which is what + + align:start position:0% +which as I said earlier is which is what + + + align:start position:0% +which as I said earlier is which is what +we want to focus on so that we can make + + align:start position:0% +we want to focus on so that we can make + + + align:start position:0% +we want to focus on so that we can make +some power and some + + align:start position:0% +some power and some + + + align:start position:0% +some power and some +heat now this chart gives you a summary + + align:start position:0% +heat now this chart gives you a summary + + + align:start position:0% +heat now this chart gives you a summary +of some of the critical thermal Neutron + + align:start position:0% +of some of the critical thermal Neutron + + + align:start position:0% +of some of the critical thermal Neutron +cross-sections of important file and + + align:start position:0% +cross-sections of important file and + + + align:start position:0% +cross-sections of important file and +fertile nucle and let me just point out + + align:start position:0% +fertile nucle and let me just point out + + + align:start position:0% +fertile nucle and let me just point out +first the uranium + + align:start position:0% +first the uranium + + + align:start position:0% +first the uranium +235 and you can see the absorption + + align:start position:0% +235 and you can see the absorption + + + align:start position:0% +235 and you can see the absorption +cross-section is quite High and the + + align:start position:0% +cross-section is quite High and the + + + align:start position:0% +cross-section is quite High and the +capture cross-section is is is somewhat + + align:start position:0% +capture cross-section is is is somewhat + + + align:start position:0% +capture cross-section is is is somewhat +lower but the the fision cross-section + + align:start position:0% +lower but the the fision cross-section + + + align:start position:0% +lower but the the fision cross-section +is is in fact very very high for a + + align:start position:0% +is is in fact very very high for a + + + align:start position:0% +is is in fact very very high for a +thermal Neutron this is a good attribute + + align:start position:0% +thermal Neutron this is a good attribute + + + align:start position:0% +thermal Neutron this is a good attribute +to have and you can see these number of + + align:start position:0% +to have and you can see these number of + + + align:start position:0% +to have and you can see these number of +neutrons produce per fision the news and + + align:start position:0% +neutrons produce per fision the news and + + + align:start position:0% +neutrons produce per fision the news and +the Adis which are also very key + + align:start position:0% +the Adis which are also very key + + + align:start position:0% +the Adis which are also very key +parameters because the the higher these + + align:start position:0% +parameters because the the higher these + + + align:start position:0% +parameters because the the higher these +numbers are the more neutrons are + + align:start position:0% +numbers are the more neutrons are + + + align:start position:0% +numbers are the more neutrons are +produced per + + align:start position:0% +produced per + + + align:start position:0% +produced per +Vision we can then look at uranium 238 + + align:start position:0% +Vision we can then look at uranium 238 + + + align:start position:0% +Vision we can then look at uranium 238 +which has a relatively low absorption in + + align:start position:0% +which has a relatively low absorption in + + + align:start position:0% +which has a relatively low absorption in +the thermal energy range and essentially + + align:start position:0% +the thermal energy range and essentially + + + align:start position:0% +the thermal energy range and essentially +has no fion cross-section which which is + + align:start position:0% +has no fion cross-section which which is + + + align:start position:0% +has no fion cross-section which which is +why we call uranium 238 a fertile uh + + align:start position:0% +why we call uranium 238 a fertile uh + + + align:start position:0% +why we call uranium 238 a fertile uh +fertile ad we can then drop down and + + align:start position:0% +fertile ad we can then drop down and + + + align:start position:0% +fertile ad we can then drop down and +look at plutonium 239 in the thermal + + align:start position:0% +look at plutonium 239 in the thermal + + + align:start position:0% +look at plutonium 239 in the thermal +energy range which has a very high + + align:start position:0% +energy range which has a very high + + + align:start position:0% +energy range which has a very high +absorption cross-section and a very very + + align:start position:0% +absorption cross-section and a very very + + + align:start position:0% +absorption cross-section and a very very +high fision cross-section which makes + + align:start position:0% +high fision cross-section which makes + + + align:start position:0% +high fision cross-section which makes +plutonium a good fuel for thermal + + align:start position:0% +plutonium a good fuel for thermal + + + align:start position:0% +plutonium a good fuel for thermal +reactors and in fact if you look at the + + align:start position:0% +reactors and in fact if you look at the + + + align:start position:0% +reactors and in fact if you look at the +depletion and the creation of plutonium + + align:start position:0% +depletion and the creation of plutonium + + + align:start position:0% +depletion and the creation of plutonium +from uranium 238 roughly 30% so of the + + align:start position:0% +from uranium 238 roughly 30% so of the + + + align:start position:0% +from uranium 238 roughly 30% so of the +power near the end of life of a fuel + + align:start position:0% +power near the end of life of a fuel + + + align:start position:0% +power near the end of life of a fuel +assembly comes from plutonium because it + + align:start position:0% +assembly comes from plutonium because it + + + align:start position:0% +assembly comes from plutonium because it +does have a very high fision + + align:start position:0% +does have a very high fision + + + align:start position:0% +does have a very high fision +cross-section and it also has a high + + align:start position:0% +cross-section and it also has a high + + + align:start position:0% +cross-section and it also has a high +Neutron production rate per fision you + + align:start position:0% +Neutron production rate per fision you + + + align:start position:0% +Neutron production rate per fision you +can see plutonium 241 also has similar + + align:start position:0% +can see plutonium 241 also has similar + + + align:start position:0% +can see plutonium 241 also has similar +characteristics and the odd isotope + + align:start position:0% +characteristics and the odd isotope + + + align:start position:0% +characteristics and the odd isotope +numbers in the plutonium uh array of + + align:start position:0% +numbers in the plutonium uh array of + + + align:start position:0% +numbers in the plutonium uh array of +nucleid are visionable and the even + + align:start position:0% +nucleid are visionable and the even + + + align:start position:0% +nucleid are visionable and the even +numbers are pretty much absorbers + + align:start position:0% + + + + align:start position:0% + +now when you look at uranium + + align:start position:0% +now when you look at uranium + + + align:start position:0% +now when you look at uranium +cross-section as a function of energy + + align:start position:0% +cross-section as a function of energy + + + align:start position:0% +cross-section as a function of energy +and that's is Neutron energy from EVS to + + align:start position:0% +and that's is Neutron energy from EVS to + + + align:start position:0% +and that's is Neutron energy from EVS to +me levels and you can see at very high + + align:start position:0% +me levels and you can see at very high + + + align:start position:0% +me levels and you can see at very high +energies uranium 238 does have a fision + + align:start position:0% +energies uranium 238 does have a fision + + + align:start position:0% +energies uranium 238 does have a fision +cross-section which in some ways can be + + align:start position:0% +cross-section which in some ways can be + + + align:start position:0% +cross-section which in some ways can be +used in Fast reactors now for us to be + + align:start position:0% +used in Fast reactors now for us to be + + + align:start position:0% +used in Fast reactors now for us to be +effective as as as a thermal reactor + + align:start position:0% +effective as as as a thermal reactor + + + align:start position:0% +effective as as as a thermal reactor +which we're in the 025 EV range we we + + align:start position:0% +which we're in the 025 EV range we we + + + align:start position:0% +which we're in the 025 EV range we we +need to take a neutron that may be born + + align:start position:0% +need to take a neutron that may be born + + + align:start position:0% +need to take a neutron that may be born +at me levels me uh energies and we need + + align:start position:0% +at me levels me uh energies and we need + + + align:start position:0% +at me levels me uh energies and we need +to slow it down so that when we get into + + align:start position:0% +to slow it down so that when we get into + + + align:start position:0% +to slow it down so that when we get into +the thermal energy range it has a high + + align:start position:0% +the thermal energy range it has a high + + + align:start position:0% +the thermal energy range it has a high +enough cross-section so that we can + + align:start position:0% +enough cross-section so that we can + + + align:start position:0% +enough cross-section so that we can +count on a on a very relatively High + + align:start position:0% +count on a on a very relatively High + + + align:start position:0% +count on a on a very relatively High +fision rate to support nuclear reactions + + align:start position:0% +fision rate to support nuclear reactions + + + align:start position:0% +fision rate to support nuclear reactions +now what you see in the middle here is a + + align:start position:0% +now what you see in the middle here is a + + + align:start position:0% +now what you see in the middle here is a +is a resonance absorption region where + + align:start position:0% +is a resonance absorption region where + + + align:start position:0% +is a resonance absorption region where +neutrons as they're slowing down through + + align:start position:0% +neutrons as they're slowing down through + + + align:start position:0% +neutrons as they're slowing down through +this region of say one to looks like a + + align:start position:0% +this region of say one to looks like a + + + align:start position:0% +this region of say one to looks like a +th000 EV you'll have probabilities of + + align:start position:0% +th000 EV you'll have probabilities of + + + align:start position:0% +th000 EV you'll have probabilities of +fision occurring but neutrons are + + align:start position:0% +fision occurring but neutrons are + + + align:start position:0% +fision occurring but neutrons are +scattering through this range and + + align:start position:0% +scattering through this range and + + + align:start position:0% +scattering through this range and +ultimately ending up in the thermal + + align:start position:0% +ultimately ending up in the thermal + + + align:start position:0% +ultimately ending up in the thermal +Spectrum now the Chain Reaction process + + align:start position:0% +Spectrum now the Chain Reaction process + + + align:start position:0% +Spectrum now the Chain Reaction process +is relatively + + align:start position:0% +is relatively + + + align:start position:0% +is relatively +straightforward and what we're trying to + + align:start position:0% +straightforward and what we're trying to + + + align:start position:0% +straightforward and what we're trying to +do is create essentially at least 2.5 + + align:start position:0% +do is create essentially at least 2.5 + + + align:start position:0% +do is create essentially at least 2.5 +neutrons so that these 2.5 neutrons 1.5 + + align:start position:0% +neutrons so that these 2.5 neutrons 1.5 + + + align:start position:0% +neutrons so that these 2.5 neutrons 1.5 +of which could be absorbed by what we + + align:start position:0% +of which could be absorbed by what we + + + align:start position:0% +of which could be absorbed by what we +call non fising nuclei + + align:start position:0% +call non fising nuclei + + + align:start position:0% +call non fising nuclei +or in fact escape from the reactor we + + align:start position:0% +or in fact escape from the reactor we + + + align:start position:0% +or in fact escape from the reactor we +need at least one Neutron to survive + + align:start position:0% +need at least one Neutron to survive + + + align:start position:0% +need at least one Neutron to survive +this non non file absorption to create + + align:start position:0% +this non non file absorption to create + + + align:start position:0% +this non non file absorption to create +our next Vision which then produces 2.5 + + align:start position:0% +our next Vision which then produces 2.5 + + + align:start position:0% +our next Vision which then produces 2.5 +neutrons which goes on and on and on and + + align:start position:0% +neutrons which goes on and on and on and + + + align:start position:0% +neutrons which goes on and on and on and +we've used a relatively simplistic term + + align:start position:0% +we've used a relatively simplistic term + + + align:start position:0% +we've used a relatively simplistic term +called Neutron multiplication factor + + align:start position:0% +called Neutron multiplication factor + + + align:start position:0% +called Neutron multiplication factor +which is the K that if the k equals 1 + + align:start position:0% +which is the K that if the k equals 1 + + + align:start position:0% +which is the K that if the k equals 1 +the neutron population is steady as is + + align:start position:0% +the neutron population is steady as is + + + align:start position:0% +the neutron population is steady as is +the fion + + align:start position:0% +the fion + + + align:start position:0% +the fion +if it's greater than one namely we + + align:start position:0% +if it's greater than one namely we + + + align:start position:0% +if it's greater than one namely we +produce more neutrons in one generation + + align:start position:0% +produce more neutrons in one generation + + + align:start position:0% +produce more neutrons in one generation +compared to the next Neutron population + + align:start position:0% +compared to the next Neutron population + + + align:start position:0% +compared to the next Neutron population +grows as does the fision as does the + + align:start position:0% +grows as does the fision as does the + + + align:start position:0% +grows as does the fision as does the +fision this supercritical condition is + + align:start position:0% +fision this supercritical condition is + + + align:start position:0% +fision this supercritical condition is +not necessarily a desirable condition + + align:start position:0% +not necessarily a desirable condition + + + align:start position:0% +not necessarily a desirable condition +for a thermal commercial nuclear power + + align:start position:0% +for a thermal commercial nuclear power + + + align:start position:0% +for a thermal commercial nuclear power +plant if the if the K is less than one + + align:start position:0% +plant if the if the K is less than one + + + align:start position:0% +plant if the if the K is less than one +the reactor is sub subcritical when in + + align:start position:0% +the reactor is sub subcritical when in + + + align:start position:0% +the reactor is sub subcritical when in +fact Neutron population will ultimately + + align:start position:0% +fact Neutron population will ultimately + + + align:start position:0% +fact Neutron population will ultimately +decrease and the uh fion rate will + + align:start position:0% +decrease and the uh fion rate will + + + align:start position:0% +decrease and the uh fion rate will +decrease ENT shutting down your reactor + + align:start position:0% +decrease ENT shutting down your reactor + + + align:start position:0% +decrease ENT shutting down your reactor +so the target for thermal reactors and + + align:start position:0% +so the target for thermal reactors and + + + align:start position:0% +so the target for thermal reactors and +reactors in general is to make sure that + + align:start position:0% +reactors in general is to make sure that + + + align:start position:0% +reactors in general is to make sure that +the neutron population and fision rate + + align:start position:0% +the neutron population and fision rate + + + align:start position:0% +the neutron population and fision rate +the absorption and loss rate is is + + align:start position:0% +the absorption and loss rate is is + + + align:start position:0% +the absorption and loss rate is is +balanced and namly the K is in fact + + align:start position:0% +balanced and namly the K is in fact + + + align:start position:0% +balanced and namly the K is in fact +one now this this slide is an + + align:start position:0% +one now this this slide is an + + + align:start position:0% +one now this this slide is an +interesting slide because it is it it + + align:start position:0% +interesting slide because it is it it + + + align:start position:0% +interesting slide because it is it it +shows you what happens when a neutron is + + align:start position:0% +shows you what happens when a neutron is + + + align:start position:0% +shows you what happens when a neutron is +is born as a result of the fision this + + align:start position:0% +is born as a result of the fision this + + + align:start position:0% +is born as a result of the fision this +is called called the fision neutron + + align:start position:0% +is called called the fision neutron + + + align:start position:0% +is called called the fision neutron +energy Spectrum based on the fishing + + align:start position:0% +energy Spectrum based on the fishing + + + align:start position:0% +energy Spectrum based on the fishing +thermal fishing of uranium + + align:start position:0% +thermal fishing of uranium + + + align:start position:0% +thermal fishing of uranium +235 you can see that this is a + + align:start position:0% +235 you can see that this is a + + + align:start position:0% +235 you can see that this is a +distribution function of energies you + + align:start position:0% +distribution function of energies you + + + align:start position:0% +distribution function of energies you +can see most of the neutrons are born + + align:start position:0% +can see most of the neutrons are born + + + align:start position:0% +can see most of the neutrons are born +within one and two me some are much + + align:start position:0% +within one and two me some are much + + + align:start position:0% +within one and two me some are much +higher in terms even up to eight but you + + align:start position:0% +higher in terms even up to eight but you + + + align:start position:0% +higher in terms even up to eight but you +use this function to determine what is + + align:start position:0% +use this function to determine what is + + + align:start position:0% +use this function to determine what is +the estimated energy of the neutrons + + align:start position:0% +the estimated energy of the neutrons + + + align:start position:0% +the estimated energy of the neutrons +coming out that will affect your ability + + align:start position:0% +coming out that will affect your ability + + + align:start position:0% +coming out that will affect your ability +to calculate the light hood of the next + + align:start position:0% +to calculate the light hood of the next + + + align:start position:0% +to calculate the light hood of the next +Vision again the target is to is to take + + align:start position:0% +Vision again the target is to is to take + + + align:start position:0% +Vision again the target is to is to take +all these energies and slow the neutrons + + align:start position:0% +all these energies and slow the neutrons + + + align:start position:0% +all these energies and slow the neutrons +down to the thermal Spectrum so that it + + align:start position:0% +down to the thermal Spectrum so that it + + + align:start position:0% +down to the thermal Spectrum so that it +can be an efficient Vision + + align:start position:0% +can be an efficient Vision + + + align:start position:0% +can be an efficient Vision +producer now what we are worried about + + align:start position:0% +producer now what we are worried about + + + align:start position:0% +producer now what we are worried about +in in in in in nuclear commercial + + align:start position:0% +in in in in in nuclear commercial + + + align:start position:0% +in in in in in nuclear commercial +nuclear power is our ability to to + + align:start position:0% +nuclear power is our ability to to + + + align:start position:0% +nuclear power is our ability to to +harness the energy of efficient and this + + align:start position:0% +harness the energy of efficient and this + + + align:start position:0% +harness the energy of efficient and this +chart explains where that energy comes + + align:start position:0% +chart explains where that energy comes + + + align:start position:0% +chart explains where that energy comes +from when you split a um a uranium 235 + + align:start position:0% +from when you split a um a uranium 235 + + + align:start position:0% +from when you split a um a uranium 235 +atom you will create what we're called + + align:start position:0% +atom you will create what we're called + + + align:start position:0% +atom you will create what we're called +fision fragments as you understand that + + align:start position:0% +fision fragments as you understand that + + + align:start position:0% +fision fragments as you understand that +when an atom is split it creates + + align:start position:0% +when an atom is split it creates + + + align:start position:0% +when an atom is split it creates +essentially two parts and these two + + align:start position:0% +essentially two parts and these two + + + align:start position:0% +essentially two parts and these two +parts carry off certain amount of energy + + align:start position:0% +parts carry off certain amount of energy + + + align:start position:0% +parts carry off certain amount of energy +and and and the energy is relatively + + align:start position:0% +and and and the energy is relatively + + + align:start position:0% +and and and the energy is relatively +large 168 + + align:start position:0% +large 168 + + + align:start position:0% +large 168 +me per fion and you'll see quickly go + + align:start position:0% +me per fion and you'll see quickly go + + + align:start position:0% +me per fion and you'll see quickly go +dropping down to the bottom that the + + align:start position:0% +dropping down to the bottom that the + + + align:start position:0% +dropping down to the bottom that the +amount of energy per vision is around + + align:start position:0% +amount of energy per vision is around + + + align:start position:0% +amount of energy per vision is around +200 me so what we want to do is be able + + align:start position:0% +200 me so what we want to do is be able + + + align:start position:0% +200 me so what we want to do is be able +to harness this energy in a way that we + + align:start position:0% +to harness this energy in a way that we + + + align:start position:0% +to harness this energy in a way that we +can produce heat to heat the water and + + align:start position:0% +can produce heat to heat the water and + + + align:start position:0% +can produce heat to heat the water and +then we ultimately make Steam so we have + + align:start position:0% +then we ultimately make Steam so we have + + + align:start position:0% +then we ultimately make Steam so we have +some energy that's taken off in the + + align:start position:0% +some energy that's taken off in the + + + align:start position:0% +some energy that's taken off in the +neutrons some PR prom gamma rays and + + align:start position:0% +neutrons some PR prom gamma rays and + + + align:start position:0% +neutrons some PR prom gamma rays and +some beta energies and also some delayed + + align:start position:0% +some beta energies and also some delayed + + + align:start position:0% +some beta energies and also some delayed +gamas but by and large the energy that + + align:start position:0% +gamas but by and large the energy that + + + align:start position:0% +gamas but by and large the energy that +is produced that is capturable as a heat + + align:start position:0% +is produced that is capturable as a heat + + + align:start position:0% +is produced that is capturable as a heat +is about 200 me most of which is in the + + align:start position:0% +is about 200 me most of which is in the + + + align:start position:0% +is about 200 me most of which is in the +heat of fision products down so this + + align:start position:0% +heat of fision products down so this + + + align:start position:0% +heat of fision products down so this +this chart gives us a sense of how we're + + align:start position:0% +this chart gives us a sense of how we're + + + align:start position:0% +this chart gives us a sense of how we're +going to be able to use a fision to + + align:start position:0% +going to be able to use a fision to + + + align:start position:0% +going to be able to use a fision to +create heat to capture ultimately in the + + align:start position:0% +create heat to capture ultimately in the + + + align:start position:0% +create heat to capture ultimately in the +uh in the water which is the + + align:start position:0% +uh in the water which is the + + + align:start position:0% +uh in the water which is the +cooler now this this chart is also an + + align:start position:0% +cooler now this this chart is also an + + + align:start position:0% +cooler now this this chart is also an +interesting chart that basically + + align:start position:0% +interesting chart that basically + + + align:start position:0% +interesting chart that basically +graphically illustrates symbolically at + + align:start position:0% +graphically illustrates symbolically at + + + align:start position:0% +graphically illustrates symbolically at +least what occurs Neutron striking + + align:start position:0% +least what occurs Neutron striking + + + align:start position:0% +least what occurs Neutron striking +uranium 235 atom releasing some gamas + + align:start position:0% +uranium 235 atom releasing some gamas + + + align:start position:0% +uranium 235 atom releasing some gamas +and some neutrons creating two fision + + align:start position:0% +and some neutrons creating two fision + + + align:start position:0% +and some neutrons creating two fision +fragments + + align:start position:0% +fragments + + + align:start position:0% +fragments +which themselves have a distribution of + + align:start position:0% +which themselves have a distribution of + + + align:start position:0% +which themselves have a distribution of +OCC currents and these Vision fragments + + align:start position:0% +OCC currents and these Vision fragments + + + align:start position:0% +OCC currents and these Vision fragments +in this example here we produce uh it + + align:start position:0% +in this example here we produce uh it + + + align:start position:0% +in this example here we produce uh it +looks like bro bromine which then + + align:start position:0% +looks like bro bromine which then + + + align:start position:0% +looks like bro bromine which then +subsequently decays in 1.6 seconds to + + align:start position:0% +subsequently decays in 1.6 seconds to + + + align:start position:0% +subsequently decays in 1.6 seconds to +Krypton which decays to another element + + align:start position:0% +Krypton which decays to another element + + + align:start position:0% +Krypton which decays to another element +strontium and I can't quite make that + + align:start position:0% +strontium and I can't quite make that + + + align:start position:0% +strontium and I can't quite make that +out and ultimately ends up as a stable + + align:start position:0% +out and ultimately ends up as a stable + + + align:start position:0% +out and ultimately ends up as a stable +zirconium and the and the time half + + align:start position:0% +zirconium and the and the time half + + + align:start position:0% +zirconium and the and the time half +lives of these r from 3 32 seconds 2.7 + + align:start position:0% +lives of these r from 3 32 seconds 2.7 + + + align:start position:0% +lives of these r from 3 32 seconds 2.7 +minutes looks like 29 years and 64 hours + + align:start position:0% +minutes looks like 29 years and 64 hours + + + align:start position:0% +minutes looks like 29 years and 64 hours +so you can see as a result of a fion we + + align:start position:0% +so you can see as a result of a fion we + + + align:start position:0% +so you can see as a result of a fion we +producing fishion fragments that also + + align:start position:0% +producing fishion fragments that also + + + align:start position:0% +producing fishion fragments that also +subsequently release energy and down on + + align:start position:0% +subsequently release energy and down on + + + align:start position:0% +subsequently release energy and down on +on this fion fragment it starts with + + align:start position:0% +on this fion fragment it starts with + + + align:start position:0% +on this fion fragment it starts with +Xenon and ends with neodium I believe + + align:start position:0% +Xenon and ends with neodium I believe + + + align:start position:0% +Xenon and ends with neodium I believe +which is the which is the last uh fion + + align:start position:0% +which is the which is the last uh fion + + + align:start position:0% +which is the which is the last uh fion +fragment and the time uh half lives are + + align:start position:0% +fragment and the time uh half lives are + + + align:start position:0% +fragment and the time uh half lives are +1 second roughly 12 seconds minutes + + align:start position:0% +1 second roughly 12 seconds minutes + + + align:start position:0% +1 second roughly 12 seconds minutes +hours and days so you can see we need to + + align:start position:0% +hours and days so you can see we need to + + + align:start position:0% +hours and days so you can see we need to +keep track even as a result of effis how + + align:start position:0% +keep track even as a result of effis how + + + align:start position:0% +keep track even as a result of effis how +all these things occur and how long they + + align:start position:0% +all these things occur and how long they + + + align:start position:0% +all these things occur and how long they +take because every one of these has a + + align:start position:0% +take because every one of these has a + + + align:start position:0% +take because every one of these has a +possibility of either an absorption a + + align:start position:0% +possibility of either an absorption a + + + align:start position:0% +possibility of either an absorption a +capture or a scattering which we need to + + align:start position:0% +capture or a scattering which we need to + + + align:start position:0% +capture or a scattering which we need to +understand if we're going to try to + + align:start position:0% +understand if we're going to try to + + + align:start position:0% +understand if we're going to try to +figure out do we have sufficient + + align:start position:0% +figure out do we have sufficient + + + align:start position:0% +figure out do we have sufficient +neutrons to go + + align:start position:0% +neutrons to go + + + align:start position:0% +neutrons to go +critical now this is the uh an + + align:start position:0% +critical now this is the uh an + + + align:start position:0% +critical now this is the uh an +interesting chart on the fion fion yield + + align:start position:0% +interesting chart on the fion fion yield + + + align:start position:0% +interesting chart on the fion fion yield +by mass number in other words if a fion + + align:start position:0% +by mass number in other words if a fion + + + align:start position:0% +by mass number in other words if a fion +occurs the uranium 235 nucleus will + + align:start position:0% +occurs the uranium 235 nucleus will + + + align:start position:0% +occurs the uranium 235 nucleus will +split up in roughly this saddle type + + align:start position:0% +split up in roughly this saddle type + + + align:start position:0% +split up in roughly this saddle type +distribution where the likelihood is + + align:start position:0% +distribution where the likelihood is + + + align:start position:0% +distribution where the likelihood is +really having a an element with a mass + + align:start position:0% +really having a an element with a mass + + + align:start position:0% +really having a an element with a mass +number in the 9s or perhaps an element + + align:start position:0% +number in the 9s or perhaps an element + + + align:start position:0% +number in the 9s or perhaps an element +with a mass number of say 140 but there + + align:start position:0% +with a mass number of say 140 but there + + + align:start position:0% +with a mass number of say 140 but there +is a distribution with a certain + + align:start position:0% +is a distribution with a certain + + + align:start position:0% +is a distribution with a certain +likelihood this too needs to be facted + + align:start position:0% +likelihood this too needs to be facted + + + align:start position:0% +likelihood this too needs to be facted +into our core physics analysis + + align:start position:0% + + + + align:start position:0% + +in order to better understand how how um + + align:start position:0% +in order to better understand how how um + + + align:start position:0% +in order to better understand how how um +these uh possibilities arise there's + + align:start position:0% +these uh possibilities arise there's + + + align:start position:0% +these uh possibilities arise there's +there's this chart of the nuclei which + + align:start position:0% +there's this chart of the nuclei which + + + align:start position:0% +there's this chart of the nuclei which +I'm sure you're all familiar with these + + align:start position:0% +I'm sure you're all familiar with these + + + align:start position:0% +I'm sure you're all familiar with these +are very important charts which depict + + align:start position:0% +are very important charts which depict + + + align:start position:0% +are very important charts which depict +every known isotope and its uh Natural + + align:start position:0% +every known isotope and its uh Natural + + + align:start position:0% +every known isotope and its uh Natural +Abundance its radiation types and + + align:start position:0% +Abundance its radiation types and + + + align:start position:0% +Abundance its radiation types and +energies it's thermal cross-section in + + align:start position:0% +energies it's thermal cross-section in + + + align:start position:0% +energies it's thermal cross-section in +Barns which is a measure of + + align:start position:0% +Barns which is a measure of + + + align:start position:0% +Barns which is a measure of +of uh this the size of the likelihood of + + align:start position:0% +of uh this the size of the likelihood of + + + align:start position:0% +of uh this the size of the likelihood of +the capture and various half lives in + + align:start position:0% +the capture and various half lives in + + + align:start position:0% +the capture and various half lives in +terms of vision cross-sections and uh of + + align:start position:0% +terms of vision cross-sections and uh of + + + align:start position:0% +terms of vision cross-sections and uh of +the various yield products so if you + + align:start position:0% +the various yield products so if you + + + align:start position:0% +the various yield products so if you +look at this and you study this you'll + + align:start position:0% +look at this and you study this you'll + + + align:start position:0% +look at this and you study this you'll +be able to completely appreciate what + + align:start position:0% +be able to completely appreciate what + + + align:start position:0% +be able to completely appreciate what +the likelihood of a uranium 235 Vision + + align:start position:0% +the likelihood of a uranium 235 Vision + + + align:start position:0% +the likelihood of a uranium 235 Vision +cross-section is capture cross-section + + align:start position:0% +cross-section is capture cross-section + + + align:start position:0% +cross-section is capture cross-section +and if it simply is a uh basic capture + + align:start position:0% +and if it simply is a uh basic capture + + + align:start position:0% +and if it simply is a uh basic capture +it might in fact go to uranium 236 with + + align:start position:0% +it might in fact go to uranium 236 with + + + align:start position:0% +it might in fact go to uranium 236 with +a certain cross-section and then + + align:start position:0% +a certain cross-section and then + + + align:start position:0% +a certain cross-section and then +ultimately decay in the sum of things so + + align:start position:0% +ultimately decay in the sum of things so + + + align:start position:0% +ultimately decay in the sum of things so +you can in fact follow the course of the + + align:start position:0% +you can in fact follow the course of the + + + align:start position:0% +you can in fact follow the course of the +Decay by understanding how these chart + + align:start position:0% +Decay by understanding how these chart + + + align:start position:0% +Decay by understanding how these chart +of the nucle in facts + + align:start position:0% +of the nucle in facts + + + align:start position:0% +of the nucle in facts +works this is very important to + + align:start position:0% +works this is very important to + + + align:start position:0% +works this is very important to +appreciate and understand now this is a + + align:start position:0% +appreciate and understand now this is a + + + align:start position:0% +appreciate and understand now this is a +typical example of a series and I'm + + align:start position:0% +typical example of a series and I'm + + + align:start position:0% +typical example of a series and I'm +going to focus not on the thorium series + + align:start position:0% +going to focus not on the thorium series + + + align:start position:0% +going to focus not on the thorium series +but on the uranium 238 Series where if a + + align:start position:0% +but on the uranium 238 Series where if a + + + align:start position:0% +but on the uranium 238 Series where if a +uranium 23 38 let me just start where + + align:start position:0% +uranium 23 38 let me just start where + + + align:start position:0% +uranium 23 38 let me just start where +where we need to be if we take uranium + + align:start position:0% +where we need to be if we take uranium + + + align:start position:0% +where we need to be if we take uranium +238 now this is sort of the uh plutonium + + align:start position:0% +238 now this is sort of the uh plutonium + + + align:start position:0% +238 now this is sort of the uh plutonium +production sequence but this chart + + align:start position:0% +production sequence but this chart + + + align:start position:0% +production sequence but this chart +explains this direction is efficient + + align:start position:0% +explains this direction is efficient + + + align:start position:0% +explains this direction is efficient +this direction is a beta Decay on this + + align:start position:0% +this direction is a beta Decay on this + + + align:start position:0% +this direction is a beta Decay on this +chart of nucleid the various + + align:start position:0% +chart of nucleid the various + + + align:start position:0% +chart of nucleid the various +cross-sections and half lives and the + + align:start position:0% +cross-sections and half lives and the + + + align:start position:0% +cross-sections and half lives and the +types of reaction that you can + + align:start position:0% +types of reaction that you can + + + align:start position:0% +types of reaction that you can +get if you follow uranium 238 it can + + align:start position:0% +get if you follow uranium 238 it can + + + align:start position:0% +get if you follow uranium 238 it can +capture + + align:start position:0% +capture + + + align:start position:0% +capture +it it can capture a neutron and go to + + align:start position:0% +it it can capture a neutron and go to + + + align:start position:0% +it it can capture a neutron and go to +uranium + + align:start position:0% +uranium + + + align:start position:0% +uranium +239 and then with 23 minute half + + align:start position:0% +239 and then with 23 minute half + + + align:start position:0% +239 and then with 23 minute half +halflife it can go to neptunium 239 + + align:start position:0% +halflife it can go to neptunium 239 + + + align:start position:0% +halflife it can go to neptunium 239 +which then in 2.3 days goes to plutonium + + align:start position:0% +which then in 2.3 days goes to plutonium + + + align:start position:0% +which then in 2.3 days goes to plutonium +239 which is the fish file isotope of + + align:start position:0% +239 which is the fish file isotope of + + + align:start position:0% +239 which is the fish file isotope of +Interest which of course then can fision + + align:start position:0% +Interest which of course then can fision + + + align:start position:0% +Interest which of course then can fision +and split up into the two fision + + align:start position:0% +and split up into the two fision + + + align:start position:0% +and split up into the two fision +fragments it can also with a half life + + align:start position:0% +fragments it can also with a half life + + + align:start position:0% +fragments it can also with a half life +of looks like 271 days the Gate of plon + + align:start position:0% +of looks like 271 days the Gate of plon + + + align:start position:0% +of looks like 271 days the Gate of plon +240 and then 241 then amarium so what + + align:start position:0% +240 and then 241 then amarium so what + + + align:start position:0% +240 and then 241 then amarium so what +we're trying to do is be able to + + align:start position:0% +we're trying to do is be able to + + + align:start position:0% +we're trying to do is be able to +appreciate all the possibilities that + + align:start position:0% +appreciate all the possibilities that + + + align:start position:0% +appreciate all the possibilities that +result from either a capture Neutron + + align:start position:0% +result from either a capture Neutron + + + align:start position:0% +result from either a capture Neutron +capture in a fertile isotope and then + + align:start position:0% +capture in a fertile isotope and then + + + align:start position:0% +capture in a fertile isotope and then +how it can become file by its Decay and + + align:start position:0% +how it can become file by its Decay and + + + align:start position:0% +how it can become file by its Decay and +or other Neutron absorptions and these + + align:start position:0% +or other Neutron absorptions and these + + + align:start position:0% +or other Neutron absorptions and these +the like you see here there's a fision + + align:start position:0% +the like you see here there's a fision + + + align:start position:0% +the like you see here there's a fision +in 238 there's efficient in 241 and + + align:start position:0% +in 238 there's efficient in 241 and + + + align:start position:0% +in 238 there's efficient in 241 and +there's efficient in 243 + + align:start position:0% +there's efficient in 243 + + + align:start position:0% +there's efficient in 243 +all this information is very important + + align:start position:0% +all this information is very important + + + align:start position:0% +all this information is very important +in understanding how these reactors + + align:start position:0% +in understanding how these reactors + + + align:start position:0% +in understanding how these reactors +actually function and whether or not we + + align:start position:0% +actually function and whether or not we + + + align:start position:0% +actually function and whether or not we +can predict + + align:start position:0% +can predict + + + align:start position:0% +can predict +prodical uh I'm not going to talk too + + align:start position:0% +prodical uh I'm not going to talk too + + + align:start position:0% +prodical uh I'm not going to talk too +much about this but in the fertile to + + align:start position:0% +much about this but in the fertile to + + + align:start position:0% +much about this but in the fertile to +file chain you look at uranium 238 + + align:start position:0% +file chain you look at uranium 238 + + + align:start position:0% +file chain you look at uranium 238 +captures the neutron 239 Li DEC goes to + + align:start position:0% +captures the neutron 239 Li DEC goes to + + + align:start position:0% +captures the neutron 239 Li DEC goes to +neptunium neptunium to plutonium 239 and + + align:start position:0% +neptunium neptunium to plutonium 239 and + + + align:start position:0% +neptunium neptunium to plutonium 239 and +this is again is the file isotope this + + align:start position:0% +this is again is the file isotope this + + + align:start position:0% +this is again is the file isotope this +is a simpler diagram than the one I just + + align:start position:0% +is a simpler diagram than the one I just + + + align:start position:0% +is a simpler diagram than the one I just +showed you but principles are the same a + + align:start position:0% +showed you but principles are the same a + + + align:start position:0% +showed you but principles are the same a +lot of people talk about the thorium + + align:start position:0% +lot of people talk about the thorium + + + align:start position:0% +lot of people talk about the thorium +fuel cycle thorium 232 capturing a + + align:start position:0% +fuel cycle thorium 232 capturing a + + + align:start position:0% +fuel cycle thorium 232 capturing a +neutron goes to thorium 233 which + + align:start position:0% +neutron goes to thorium 233 which + + + align:start position:0% +neutron goes to thorium 233 which +ultimately decays to uranium 233 which + + align:start position:0% +ultimately decays to uranium 233 which + + + align:start position:0% +ultimately decays to uranium 233 which +is again a fysal isotope that can be + + align:start position:0% +is again a fysal isotope that can be + + + align:start position:0% +is again a fysal isotope that can be +used to power nuclear power plants based + + align:start position:0% +used to power nuclear power plants based + + + align:start position:0% +used to power nuclear power plants based +on a thorium fuel cycle not a uranium + + align:start position:0% +on a thorium fuel cycle not a uranium + + + align:start position:0% +on a thorium fuel cycle not a uranium +fuel + + align:start position:0% +fuel + + + align:start position:0% +fuel +cycle so what is it that we're + + align:start position:0% +cycle so what is it that we're + + + align:start position:0% +cycle so what is it that we're +ultimately trying to do in U in nuclear + + align:start position:0% +ultimately trying to do in U in nuclear + + + align:start position:0% +ultimately trying to do in U in nuclear +power we want want to make and capture + + align:start position:0% +power we want want to make and capture + + + align:start position:0% +power we want want to make and capture +the heat from the fishion + + align:start position:0% +the heat from the fishion + + + align:start position:0% +the heat from the fishion +process and in order to do that we've + + align:start position:0% +process and in order to do that we've + + + align:start position:0% +process and in order to do that we've +got to design a core and the core has to + + align:start position:0% +got to design a core and the core has to + + + align:start position:0% +got to design a core and the core has to +be able + + align:start position:0% +be able + + + align:start position:0% +be able +to uh contain a sufficient amount of + + align:start position:0% +to uh contain a sufficient amount of + + + align:start position:0% +to uh contain a sufficient amount of +uranium in a certain configuration that + + align:start position:0% +uranium in a certain configuration that + + + align:start position:0% +uranium in a certain configuration that +will not leak out neutrons and sustain + + align:start position:0% +will not leak out neutrons and sustain + + + align:start position:0% +will not leak out neutrons and sustain +itself for a 12 to 24 month period such + + align:start position:0% +itself for a 12 to 24 month period such + + + align:start position:0% +itself for a 12 to 24 month period such +that we can harness the energy without + + align:start position:0% +that we can harness the energy without + + + align:start position:0% +that we can harness the energy without +refueling more often than 12 to 24 + + align:start position:0% +refueling more often than 12 to 24 + + + align:start position:0% +refueling more often than 12 to 24 +months mon so we need to consider is + + align:start position:0% +months mon so we need to consider is + + + align:start position:0% +months mon so we need to consider is +what we in fact put into the core in + + align:start position:0% +what we in fact put into the core in + + + align:start position:0% +what we in fact put into the core in +terms of the fuel we need to config we + + align:start position:0% +terms of the fuel we need to config we + + + align:start position:0% +terms of the fuel we need to config we +need to understand what kinds of other + + align:start position:0% +need to understand what kinds of other + + + align:start position:0% +need to understand what kinds of other +materials need to go in the fuel such as + + align:start position:0% +materials need to go in the fuel such as + + + align:start position:0% +materials need to go in the fuel such as +the cladding the internal structures + + align:start position:0% +the cladding the internal structures + + + align:start position:0% +the cladding the internal structures +that could be absorbers that would take + + align:start position:0% +that could be absorbers that would take + + + align:start position:0% +that could be absorbers that would take +away neutrons we have to decide on how + + align:start position:0% +away neutrons we have to decide on how + + + align:start position:0% +away neutrons we have to decide on how +long a life of the Reactor Core we want + + align:start position:0% +long a life of the Reactor Core we want + + + align:start position:0% +long a life of the Reactor Core we want +and by LifeTime we mean the time from + + align:start position:0% +and by LifeTime we mean the time from + + + align:start position:0% +and by LifeTime we mean the time from +when we start up the reactor till the + + align:start position:0% +when we start up the reactor till the + + + align:start position:0% +when we start up the reactor till the +time that we need to refuel it that + + align:start position:0% +time that we need to refuel it that + + + align:start position:0% +time that we need to refuel it that +obviously affects the amount of fuel you + + align:start position:0% +obviously affects the amount of fuel you + + + align:start position:0% +obviously affects the amount of fuel you +put in and the fundamentals of the + + align:start position:0% +put in and the fundamentals of the + + + align:start position:0% +put in and the fundamentals of the +internals of the design this reactivity + + align:start position:0% +internals of the design this reactivity + + + align:start position:0% +internals of the design this reactivity +swing is a measure of from the initial + + align:start position:0% +swing is a measure of from the initial + + + align:start position:0% +swing is a measure of from the initial +enrichment which is will have to be over + + align:start position:0% +enrichment which is will have to be over + + + align:start position:0% +enrichment which is will have to be over +enriched in uranium to a point when all + + align:start position:0% +enriched in uranium to a point when all + + + align:start position:0% +enriched in uranium to a point when all +the uranium that's you is used up making + + align:start position:0% +the uranium that's you is used up making + + + align:start position:0% +the uranium that's you is used up making +the reactor subcritical that's the + + align:start position:0% +the reactor subcritical that's the + + + align:start position:0% +the reactor subcritical that's the +ultimate reactivity swing during + + align:start position:0% +ultimate reactivity swing during + + + align:start position:0% +ultimate reactivity swing during +operation and we also have to consider + + align:start position:0% +operation and we also have to consider + + + align:start position:0% +operation and we also have to consider +certain refueling strategies and what + + align:start position:0% +certain refueling strategies and what + + + align:start position:0% +certain refueling strategies and what +this basically means is do we want to + + align:start position:0% +this basically means is do we want to + + + align:start position:0% +this basically means is do we want to +take the entire core out and replace it + + align:start position:0% +take the entire core out and replace it + + + align:start position:0% +take the entire core out and replace it +with a fresh core or do we want to take + + align:start position:0% +with a fresh core or do we want to take + + + align:start position:0% +with a fresh core or do we want to take +a third of the core out or a quarter of + + align:start position:0% +a third of the core out or a quarter of + + + align:start position:0% +a third of the core out or a quarter of +the core out and that refueling strategy + + align:start position:0% +the core out and that refueling strategy + + + align:start position:0% +the core out and that refueling strategy +is largely dictated by economics and + + align:start position:0% +is largely dictated by economics and + + + align:start position:0% +is largely dictated by economics and +refueling + + align:start position:0% +refueling + + + align:start position:0% +refueling +interval so what we're going to now + + align:start position:0% +interval so what we're going to now + + + align:start position:0% +interval so what we're going to now +explore is how do we in fact make the + + align:start position:0% +explore is how do we in fact make the + + + align:start position:0% +explore is how do we in fact make the +power and how do we understand how to + + align:start position:0% +power and how do we understand how to + + + align:start position:0% +power and how do we understand how to +calculate + + align:start position:0% +calculate + + + align:start position:0% +calculate +that so we mentioned earlier one of the + + align:start position:0% +that so we mentioned earlier one of the + + + align:start position:0% +that so we mentioned earlier one of the +important things for us to do is take + + align:start position:0% +important things for us to do is take + + + align:start position:0% +important things for us to do is take +neutrons that are born + + align:start position:0% +neutrons that are born + + + align:start position:0% +neutrons that are born +fast slow them down and then have them + + align:start position:0% +fast slow them down and then have them + + + align:start position:0% +fast slow them down and then have them +thermalized so that they can be used as + + align:start position:0% +thermalized so that they can be used as + + + align:start position:0% +thermalized so that they can be used as +a neutron population to create fions so + + align:start position:0% +a neutron population to create fions so + + + align:start position:0% +a neutron population to create fions so +essentially all the neutrons are born + + align:start position:0% +essentially all the neutrons are born + + + align:start position:0% +essentially all the neutrons are born +fast from a + + align:start position:0% +fast from a + + + align:start position:0% +fast from a +fision and we need to have them slow + + align:start position:0% +fision and we need to have them slow + + + align:start position:0% +fision and we need to have them slow +down through this resonance region by + + align:start position:0% +down through this resonance region by + + + align:start position:0% +down through this resonance region by +multiple + + align:start position:0% +multiple + + + align:start position:0% +multiple +scatterings with moderator the moderator + + align:start position:0% +scatterings with moderator the moderator + + + align:start position:0% +scatterings with moderator the moderator +being the material that we put into the + + align:start position:0% +being the material that we put into the + + + align:start position:0% +being the material that we put into the +core which typically in a light Water + + align:start position:0% +core which typically in a light Water + + + align:start position:0% +core which typically in a light Water +Reactor is water that we want to have + + align:start position:0% +Reactor is water that we want to have + + + align:start position:0% +Reactor is water that we want to have +the neutrons scattered and by scattering + + align:start position:0% +the neutrons scattered and by scattering + + + align:start position:0% +the neutrons scattered and by scattering +it's hopefully elastic scattering to + + align:start position:0% +it's hopefully elastic scattering to + + + align:start position:0% +it's hopefully elastic scattering to +have the neutron slow down to a point + + align:start position:0% +have the neutron slow down to a point + + + align:start position:0% +have the neutron slow down to a point +and not be absorbed such that they end + + align:start position:0% +and not be absorbed such that they end + + + align:start position:0% +and not be absorbed such that they end +up in the thermal regime which can be + + align:start position:0% +up in the thermal regime which can be + + + align:start position:0% +up in the thermal regime which can be +used to uh to make the + + align:start position:0% +used to uh to make the + + + align:start position:0% +used to uh to make the +power this is the challenge now as you + + align:start position:0% +power this is the challenge now as you + + + align:start position:0% +power this is the challenge now as you +recall from the uranium 238 slide and I + + align:start position:0% +recall from the uranium 238 slide and I + + + align:start position:0% +recall from the uranium 238 slide and I +think the next slide will show it now + + align:start position:0% +think the next slide will show it now + + + align:start position:0% +think the next slide will show it now +this is a function of cross-section as a + + align:start position:0% +this is a function of cross-section as a + + + align:start position:0% +this is a function of cross-section as a +function of energy on a lock plot you + + align:start position:0% +function of energy on a lock plot you + + + align:start position:0% +function of energy on a lock plot you +have the fast region and then you have a + + align:start position:0% +have the fast region and then you have a + + + align:start position:0% +have the fast region and then you have a +resonance region and this is a standard + + align:start position:0% +resonance region and this is a standard + + + align:start position:0% +resonance region and this is a standard +plot and near the thermal energy range + + align:start position:0% +plot and near the thermal energy range + + + align:start position:0% +plot and near the thermal energy range +we have this 1 overv region which which + + align:start position:0% +we have this 1 overv region which which + + + align:start position:0% +we have this 1 overv region which which +is a typical description of how the + + align:start position:0% +is a typical description of how the + + + align:start position:0% +is a typical description of how the +cross-section will increase with uh the + + align:start position:0% +cross-section will increase with uh the + + + align:start position:0% +cross-section will increase with uh the +velocity or actually will decrease will + + align:start position:0% +velocity or actually will decrease will + + + align:start position:0% +velocity or actually will decrease will +the cross-section will increase as the + + align:start position:0% +the cross-section will increase as the + + + align:start position:0% +the cross-section will increase as the +Velocity in fact decreases so what we're + + align:start position:0% +Velocity in fact decreases so what we're + + + align:start position:0% +Velocity in fact decreases so what we're +trying to do is find a way that we can + + align:start position:0% +trying to do is find a way that we can + + + align:start position:0% +trying to do is find a way that we can +get neutrons in this region not to be + + align:start position:0% +get neutrons in this region not to be + + + align:start position:0% +get neutrons in this region not to be +captured into resonance and then survive + + align:start position:0% +captured into resonance and then survive + + + align:start position:0% +captured into resonance and then survive +to this region and this is the challenge + + align:start position:0% +to this region and this is the challenge + + + align:start position:0% +to this region and this is the challenge +of reactor + + align:start position:0% +of reactor + + + align:start position:0% +of reactor +design now when we think about a + + align:start position:0% +design now when we think about a + + + align:start position:0% +design now when we think about a +moderator which is + + align:start position:0% +moderator which is + + + align:start position:0% +moderator which is +that material water or perhaps graphite + + align:start position:0% +that material water or perhaps graphite + + + align:start position:0% +that material water or perhaps graphite +that we put in a reactor we want to be + + align:start position:0% +that we put in a reactor we want to be + + + align:start position:0% +that we put in a reactor we want to be +able to select a moderator that has + + align:start position:0% +able to select a moderator that has + + + align:start position:0% +able to select a moderator that has +obviously a + + align:start position:0% +obviously a + + + align:start position:0% +obviously a +low capture cross-section and a high + + align:start position:0% +low capture cross-section and a high + + + align:start position:0% +low capture cross-section and a high +potential for elastic scattering in + + align:start position:0% +potential for elastic scattering in + + + align:start position:0% +potential for elastic scattering in +terms of reducing the energy of the + + align:start position:0% +terms of reducing the energy of the + + + align:start position:0% +terms of reducing the energy of the +neutron more so the fewer collisions the + + align:start position:0% +neutron more so the fewer collisions the + + + align:start position:0% +neutron more so the fewer collisions the +to reduce the the neutron energy to + + align:start position:0% +to reduce the the neutron energy to + + + align:start position:0% +to reduce the the neutron energy to +Thermal energies the better you are and + + align:start position:0% +Thermal energies the better you are and + + + align:start position:0% +Thermal energies the better you are and +that's the less likely that that + + align:start position:0% +that's the less likely that that + + + align:start position:0% +that's the less likely that that +particular Neutron will be captured so + + align:start position:0% +particular Neutron will be captured so + + + align:start position:0% +particular Neutron will be captured so +here are some uh nucleid of Interest + + align:start position:0% +here are some uh nucleid of Interest + + + align:start position:0% +here are some uh nucleid of Interest +hydrogen detarium carbon sodium and + + align:start position:0% +hydrogen detarium carbon sodium and + + + align:start position:0% +hydrogen detarium carbon sodium and +obviously uranium and you can see that + + align:start position:0% +obviously uranium and you can see that + + + align:start position:0% +obviously uranium and you can see that +the change in energy as a result of a + + align:start position:0% +the change in energy as a result of a + + + align:start position:0% +the change in energy as a result of a +collision is is really strongly + + align:start position:0% +collision is is really strongly + + + align:start position:0% +collision is is really strongly +determined by the mass you can see the + + align:start position:0% +determined by the mass you can see the + + + align:start position:0% +determined by the mass you can see the +amount of energy change over the certain + + align:start position:0% +amount of energy change over the certain + + + align:start position:0% +amount of energy change over the certain +energy uranium 238 is not a particularly + + align:start position:0% +energy uranium 238 is not a particularly + + + align:start position:0% +energy uranium 238 is not a particularly +good moderator however uterum is a very + + align:start position:0% +good moderator however uterum is a very + + + align:start position:0% +good moderator however uterum is a very +good moderator as as is hydrogen so + + align:start position:0% +good moderator as as is hydrogen so + + + align:start position:0% +good moderator as as is hydrogen so +we're trying to do and sodium just for + + align:start position:0% +we're trying to do and sodium just for + + + align:start position:0% +we're trying to do and sodium just for +the record is not a very good moderator + + align:start position:0% +the record is not a very good moderator + + + align:start position:0% +the record is not a very good moderator +and we use sodium for fast reactiv so + + align:start position:0% +and we use sodium for fast reactiv so + + + align:start position:0% +and we use sodium for fast reactiv so +that we're trying to understand the + + align:start position:0% +that we're trying to understand the + + + align:start position:0% +that we're trying to understand the +number of collisions required to + + align:start position:0% +number of collisions required to + + + align:start position:0% +number of collisions required to +thermalize a neutron and water is quite + + align:start position:0% +thermalize a neutron and water is quite + + + align:start position:0% +thermalize a neutron and water is quite +good uterum is also quite good + + align:start position:0% +good uterum is also quite good + + + align:start position:0% +good uterum is also quite good +but carbon is all right clearly the + + align:start position:0% +but carbon is all right clearly the + + + align:start position:0% +but carbon is all right clearly the +heavier the atom the less effective it + + align:start position:0% +heavier the atom the less effective it + + + align:start position:0% +heavier the atom the less effective it +is because it's s like a billiard ball + + align:start position:0% +is because it's s like a billiard ball + + + align:start position:0% +is because it's s like a billiard ball +collision with a heavier atom so typical + + align:start position:0% +collision with a heavier atom so typical + + + align:start position:0% +collision with a heavier atom so typical +moderators in reactors thermal reactors + + align:start position:0% +moderators in reactors thermal reactors + + + align:start position:0% +moderators in reactors thermal reactors +are dyum and hydrogen graphite can also + + align:start position:0% +are dyum and hydrogen graphite can also + + + align:start position:0% +are dyum and hydrogen graphite can also +be used and these lethargies are are + + align:start position:0% +be used and these lethargies are are + + + align:start position:0% +be used and these lethargies are are +basically the amount of energy lost per + + align:start position:0% +basically the amount of energy lost per + + + align:start position:0% +basically the amount of energy lost per +Collision so this is the reason why + + align:start position:0% +Collision so this is the reason why + + + align:start position:0% +Collision so this is the reason why +water is in fact chosen fewer number of + + align:start position:0% +water is in fact chosen fewer number of + + + align:start position:0% +water is in fact chosen fewer number of +collisions + + align:start position:0% +collisions + + + align:start position:0% +collisions +to allow for Effective slowing down + + align:start position:0% +to allow for Effective slowing down + + + align:start position:0% +to allow for Effective slowing down +which reduces the likelihood of + + align:start position:0% +which reduces the likelihood of + + + align:start position:0% +which reduces the likelihood of +capture now when we think about trying + + align:start position:0% +capture now when we think about trying + + + align:start position:0% +capture now when we think about trying +to calculate the um criticality of a + + align:start position:0% +to calculate the um criticality of a + + + align:start position:0% +to calculate the um criticality of a +reactor there are infinite systems which + + align:start position:0% +reactor there are infinite systems which + + + align:start position:0% +reactor there are infinite systems which +means the the structure is is or the + + align:start position:0% +means the the structure is is or the + + + align:start position:0% +means the the structure is is or the +design of the core is + + align:start position:0% +design of the core is + + + align:start position:0% +design of the core is +infinite uh which does not take into + + align:start position:0% +infinite uh which does not take into + + + align:start position:0% +infinite uh which does not take into +account + + align:start position:0% +account + + + align:start position:0% +account +leakage and there's a simple four Factor + + align:start position:0% +leakage and there's a simple four Factor + + + align:start position:0% +leakage and there's a simple four Factor +formula that we that we use to + + align:start position:0% +formula that we that we use to + + + align:start position:0% +formula that we that we use to +essentially compare infinite systems or + + align:start position:0% +essentially compare infinite systems or + + + align:start position:0% +essentially compare infinite systems or +infinite core cores we also have F + + align:start position:0% +infinite core cores we also have F + + + align:start position:0% +infinite core cores we also have F +finite systems which consider leakage + + align:start position:0% +finite systems which consider leakage + + + align:start position:0% +finite systems which consider leakage +and and various leakage opportunities + + align:start position:0% +and and various leakage opportunities + + + align:start position:0% +and and various leakage opportunities +for fast neutrons and thermal neutrons + + align:start position:0% +for fast neutrons and thermal neutrons + + + align:start position:0% +for fast neutrons and thermal neutrons +and the way we capture all of this is is + + align:start position:0% +and the way we capture all of this is is + + + align:start position:0% +and the way we capture all of this is is +through what we now call diffusion + + align:start position:0% +through what we now call diffusion + + + align:start position:0% +through what we now call diffusion +Theory which is a simplified notion of + + align:start position:0% +Theory which is a simplified notion of + + + align:start position:0% +Theory which is a simplified notion of +how the rate of production rate of + + align:start position:0% +how the rate of production rate of + + + align:start position:0% +how the rate of production rate of +capture and absorption and loss of + + align:start position:0% +capture and absorption and loss of + + + align:start position:0% +capture and absorption and loss of +is handled so let me just now talk a bit + + align:start position:0% +is handled so let me just now talk a bit + + + align:start position:0% +is handled so let me just now talk a bit +about these infinite + + align:start position:0% +about these infinite + + + align:start position:0% +about these infinite +systems and in an infinite system and + + align:start position:0% +systems and in an infinite system and + + + align:start position:0% +systems and in an infinite system and +we're going to calculate the four Factor + + align:start position:0% +we're going to calculate the four Factor + + + align:start position:0% +we're going to calculate the four Factor +formula which you're I'm sure quite + + align:start position:0% +formula which you're I'm sure quite + + + align:start position:0% +formula which you're I'm sure quite +familiar with but an infinite system + + align:start position:0% +familiar with but an infinite system + + + align:start position:0% +familiar with but an infinite system +essentially is is one in which there is + + align:start position:0% +essentially is is one in which there is + + + align:start position:0% +essentially is is one in which there is +no no + + align:start position:0% + + + + align:start position:0% + +leakage and the fuel + + align:start position:0% +leakage and the fuel + + + align:start position:0% +leakage and the fuel +is infinitely distributed which + + align:start position:0% +is infinitely distributed which + + + align:start position:0% +is infinitely distributed which +obviously is not realistic what I like + + align:start position:0% +obviously is not realistic what I like + + + align:start position:0% +obviously is not realistic what I like +to do now is talk about an infinite + + align:start position:0% +to do now is talk about an infinite + + + align:start position:0% +to do now is talk about an infinite +system and an infinite system is + + align:start position:0% +system and an infinite system is + + + align:start position:0% +system and an infinite system is +basically a system that has the core + + align:start position:0% +basically a system that has the core + + + align:start position:0% +basically a system that has the core +that's infinitely dispersed which is + + align:start position:0% +that's infinitely dispersed which is + + + align:start position:0% +that's infinitely dispersed which is +obviously not realistic but the key here + + align:start position:0% +obviously not realistic but the key here + + + align:start position:0% +obviously not realistic but the key here +is no + + align:start position:0% +is no + + + align:start position:0% +is no +leakage and we can characterize the the + + align:start position:0% +leakage and we can characterize the the + + + align:start position:0% +leakage and we can characterize the the +U the K which we call the K + + align:start position:0% +U the K which we call the K + + + align:start position:0% +U the K which we call the K +infinite by number of + + align:start position:0% +infinite by number of + + + align:start position:0% +infinite by number of +terms now the first thing that happens + + align:start position:0% +terms now the first thing that happens + + + align:start position:0% +terms now the first thing that happens +as you recall is that a fision is + + align:start position:0% +as you recall is that a fision is + + + align:start position:0% +as you recall is that a fision is +produced + + align:start position:0% +produced + + + align:start position:0% +produced +and we Define a number of terms let me + + align:start position:0% +and we Define a number of terms let me + + + align:start position:0% +and we Define a number of terms let me +Define this Epsilon as the + + align:start position:0% +Define this Epsilon as the + + + align:start position:0% +Define this Epsilon as the +fast + + align:start position:0% + + + + align:start position:0% + +Vision + + align:start position:0% + + + + align:start position:0% + +Factor now we haven't gotten to these + + align:start position:0% +Factor now we haven't gotten to these + + + align:start position:0% +Factor now we haven't gotten to these +definitions but it's + + align:start position:0% +definitions but it's + + + align:start position:0% +definitions but it's +total + + align:start position:0% + + + + align:start position:0% + +Visions which are the fast plus the + + align:start position:0% + + + + align:start position:0% + +thermal divided by the thermal + + align:start position:0% + + + + align:start position:0% + +fions recalling that we could have also + + align:start position:0% +fions recalling that we could have also + + + align:start position:0% +fions recalling that we could have also +fast + + align:start position:0% +fast + + + align:start position:0% +fast +Visions the next term that we use is the + + align:start position:0% +Visions the next term that we use is the + + + align:start position:0% +Visions the next term that we use is the +resonance that's a p resonance + + align:start position:0% + + + + align:start position:0% + +Escape + + align:start position:0% + + + + align:start position:0% + +probability and that's a measure of once + + align:start position:0% +probability and that's a measure of once + + + align:start position:0% +probability and that's a measure of once +a neutron is born what's the probability + + align:start position:0% +a neutron is born what's the probability + + + align:start position:0% +a neutron is born what's the probability +that Neutron survives and ends up in the + + align:start position:0% +that Neutron survives and ends up in the + + + align:start position:0% +that Neutron survives and ends up in the +thermal regime and that is measured as a + + align:start position:0% +thermal regime and that is measured as a + + + align:start position:0% +thermal regime and that is measured as a +macroscopic + + align:start position:0% +macroscopic + + + align:start position:0% +macroscopic +cross-section of uh + + align:start position:0% +cross-section of uh + + + align:start position:0% +cross-section of uh +absorption + + align:start position:0% +absorption + + + align:start position:0% +absorption +thermal divided by the + + align:start position:0% +thermal divided by the + + + align:start position:0% +thermal divided by the +integral of all energies in terms of ab + + align:start position:0% +integral of all energies in terms of ab + + + align:start position:0% +integral of all energies in terms of ab +absorptions and the absorption + + align:start position:0% +absorptions and the absorption + + + align:start position:0% +absorptions and the absorption +cross-section as you + + align:start position:0% +cross-section as you + + + align:start position:0% +cross-section as you +know is a function of the capture + + align:start position:0% +know is a function of the capture + + + align:start position:0% +know is a function of the capture +cross-section plus the fision + + align:start position:0% +cross-section plus the fision + + + align:start position:0% +cross-section plus the fision +cross-section and cross-sections also as + + align:start position:0% +cross-section and cross-sections also as + + + align:start position:0% +cross-section and cross-sections also as +you are + + align:start position:0% +you are + + + align:start position:0% +you are +aware are the number density times the + + align:start position:0% +aware are the number density times the + + + align:start position:0% +aware are the number density times the +microscopic cross-section + + align:start position:0% +microscopic cross-section + + + align:start position:0% +microscopic cross-section +and whether it be a absorption or a + + align:start position:0% +and whether it be a absorption or a + + + align:start position:0% +and whether it be a absorption or a +fision or a + + align:start position:0% +fision or a + + + align:start position:0% +fision or a +scattering the same terms apply so we + + align:start position:0% +scattering the same terms apply so we + + + align:start position:0% +scattering the same terms apply so we +have a resonance Escape probability + + align:start position:0% +have a resonance Escape probability + + + align:start position:0% +have a resonance Escape probability +which is measured in this + + align:start position:0% +which is measured in this + + + align:start position:0% +which is measured in this +term then we + + align:start position:0% +term then we + + + align:start position:0% +term then we +have the + + align:start position:0% +have the + + + align:start position:0% +have the +new which is the + + align:start position:0% +new which is the + + + align:start position:0% +new which is the +number of + + align:start position:0% + + + + align:start position:0% + +neutrons produce pervision + + align:start position:0% + + + + align:start position:0% + +and then we have an + + align:start position:0% +and then we have an + + + align:start position:0% +and then we have an +ADA which is the + + align:start position:0% + + + + align:start position:0% + +average + + align:start position:0% +average + + + align:start position:0% +average +number of fision + + align:start position:0% + + + + align:start position:0% + +neutrons produce + + align:start position:0% +neutrons produce + + + align:start position:0% +neutrons produce +per + + align:start position:0% + + + + align:start position:0% + +thermal Neutron + + align:start position:0% + + + + align:start position:0% + +absorbed + + align:start position:0% + + + + align:start position:0% + +inable + + align:start position:0% + + + + align:start position:0% + +material so when you combine all of + + align:start position:0% +material so when you combine all of + + + align:start position:0% +material so when you combine all of +these factors you get the + + align:start position:0% +these factors you get the + + + align:start position:0% +these factors you get the +familiar or I neglected to + + align:start position:0% +familiar or I neglected to + + + align:start position:0% +familiar or I neglected to +menion the thermal utilization Factor + + align:start position:0% +menion the thermal utilization Factor + + + align:start position:0% +menion the thermal utilization Factor +here + + align:start position:0% +here + + + align:start position:0% +here +which is the fourth term and I'll just + + align:start position:0% +which is the fourth term and I'll just + + + align:start position:0% +which is the fourth term and I'll just +put that up here which is the F which is + + align:start position:0% +put that up here which is the F which is + + + align:start position:0% +put that up here which is the F which is +the + + align:start position:0% + + + + align:start position:0% + +thermal utilization + + align:start position:0% + + + + align:start position:0% + +factor and that is measured by the + + align:start position:0% +factor and that is measured by the + + + align:start position:0% +factor and that is measured by the +macroscopic vision + + align:start position:0% +macroscopic vision + + + align:start position:0% +macroscopic vision +cross-section divided by the macroscopic + + align:start position:0% +cross-section divided by the macroscopic + + + align:start position:0% +cross-section divided by the macroscopic +absorption + + align:start position:0% +absorption + + + align:start position:0% +absorption +cross-section over all energy + + align:start position:0% + + + + align:start position:0% + +and this is + + align:start position:0% +and this is + + + align:start position:0% +and this is +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +the most important or one of the most + + align:start position:0% +the most important or one of the most + + + align:start position:0% +the most important or one of the most +important criteria which is basically it + + align:start position:0% +important criteria which is basically it + + + align:start position:0% +important criteria which is basically it +measures the fraction of the total + + align:start position:0% +measures the fraction of the total + + + align:start position:0% +measures the fraction of the total +neutrons absorbed uh inv visionable + + align:start position:0% +neutrons absorbed uh inv visionable + + + align:start position:0% +neutrons absorbed uh inv visionable +nucleid and that gives you this this + + align:start position:0% +nucleid and that gives you this this + + + align:start position:0% +nucleid and that gives you this this +term here so when you write the four + + align:start position:0% +term here so when you write the four + + + align:start position:0% +term here so when you write the four +Factor formula you end up with the + + align:start position:0% +Factor formula you end up with the + + + align:start position:0% +Factor formula you end up with the +probability at Escape Vision time the + + align:start position:0% +probability at Escape Vision time the + + + align:start position:0% +probability at Escape Vision time the +thermal utilization Factor time the Ada + + align:start position:0% +thermal utilization Factor time the Ada + + + align:start position:0% +thermal utilization Factor time the Ada +time the + + align:start position:0% + + + + align:start position:0% + +Epsilon and that assumes obviously no + + align:start position:0% +Epsilon and that assumes obviously no + + + align:start position:0% +Epsilon and that assumes obviously no +leakage and this is a rough parameter + + align:start position:0% +leakage and this is a rough parameter + + + align:start position:0% +leakage and this is a rough parameter +that one uses to see and judge + + align:start position:0% +that one uses to see and judge + + + align:start position:0% +that one uses to see and judge +comparative core designs and core + + align:start position:0% +comparative core designs and core + + + align:start position:0% +comparative core designs and core +systems but that's not really + + align:start position:0% +systems but that's not really + + + align:start position:0% +systems but that's not really +that that helpful for actually reacting + + align:start position:0% +that that helpful for actually reacting + + + align:start position:0% +that that helpful for actually reacting +design + + align:start position:0% + + + + align:start position:0% + +the the most important + + align:start position:0% +the the most important + + + align:start position:0% +the the most important +one is for finite + + align:start position:0% + + + + align:start position:0% + +systems we have a k + + align:start position:0% + + + + align:start position:0% + +effective which does consider + + align:start position:0% + + + + align:start position:0% + +leakage now K effective can be defined + + align:start position:0% +leakage now K effective can be defined + + + align:start position:0% +leakage now K effective can be defined +relatively straightforwardly + + align:start position:0% +relatively straightforwardly + + + align:start position:0% +relatively straightforwardly +by + + align:start position:0% +by + + + align:start position:0% +by +production of of + + align:start position:0% +production of of + + + align:start position:0% +production of of +neutrons divided by + + align:start position:0% + + + + align:start position:0% + +losses so if you have a certain number + + align:start position:0% +losses so if you have a certain number + + + align:start position:0% +losses so if you have a certain number +of neutrons produced and and that equals + + align:start position:0% +of neutrons produced and and that equals + + + align:start position:0% +of neutrons produced and and that equals +the production and that equals the + + align:start position:0% +the production and that equals the + + + align:start position:0% +the production and that equals the +number of losses your K effective would + + align:start position:0% +number of losses your K effective would + + + align:start position:0% +number of losses your K effective would +be one which is the desirable + + align:start position:0% +be one which is the desirable + + + align:start position:0% +be one which is the desirable +function + + align:start position:0% +function + + + align:start position:0% +function +now if you think about K + + align:start position:0% +now if you think about K + + + align:start position:0% +now if you think about K +effective you will have a production + + align:start position:0% +effective you will have a production + + + align:start position:0% +effective you will have a production +term which we can get to and the + + align:start position:0% +term which we can get to and the + + + align:start position:0% +term which we can get to and the +[Music] + + align:start position:0% + + + + align:start position:0% + +losses are not only by + + align:start position:0% +losses are not only by + + + align:start position:0% +losses are not only by +absorption but also by + + align:start position:0% + + + + align:start position:0% + +leakage and this is is the important + + align:start position:0% +leakage and this is is the important + + + align:start position:0% +leakage and this is is the important +phenomenon to understand and and if + + align:start position:0% +phenomenon to understand and and if + + + align:start position:0% +phenomenon to understand and and if +you rewrite + + align:start position:0% + + + + align:start position:0% + +this + + align:start position:0% +this + + + align:start position:0% +this +equation you will be able to get a + + align:start position:0% +equation you will be able to get a + + + align:start position:0% +equation you will be able to get a +term that can be written this way which + + align:start position:0% +term that can be written this way which + + + align:start position:0% +term that can be written this way which +is + + align:start position:0% +is + + + align:start position:0% +is +leakage over + + align:start position:0% + + + + align:start position:0% + +absorption and this is this term here is + + align:start position:0% +absorption and this is this term here is + + + align:start position:0% +absorption and this is this term here is +sometimes called + + align:start position:0% + + + + align:start position:0% + +excess + + align:start position:0% + + + + align:start position:0% + +multiplication + + align:start position:0% + + + + align:start position:0% + +okay important + + align:start position:0% +okay important + + + align:start position:0% +okay important +concept what I'd like to now do is go to + + align:start position:0% +concept what I'd like to now do is go to + + + align:start position:0% +concept what I'd like to now do is go to +the next + + align:start position:0% +the next + + + align:start position:0% +the next +slide now if we look at this Neutron + + align:start position:0% +slide now if we look at this Neutron + + + align:start position:0% +slide now if we look at this Neutron +life cycle again with a more + + align:start position:0% +life cycle again with a more + + + align:start position:0% +life cycle again with a more +sophisticated + + align:start position:0% +sophisticated + + + align:start position:0% +sophisticated +analysis which + + align:start position:0% +analysis which + + + align:start position:0% +analysis which +um addresses leakage at + + align:start position:0% +um addresses leakage at + + + align:start position:0% +um addresses leakage at +high uh High energies and at low + + align:start position:0% +high uh High energies and at low + + + align:start position:0% +high uh High energies and at low +energies this chart sort of results with + + align:start position:0% +energies this chart sort of results with + + + align:start position:0% +energies this chart sort of results with +the same phenomenon occurs without + + align:start position:0% +the same phenomenon occurs without + + + align:start position:0% +the same phenomenon occurs without +spending a lot of time on each one of + + align:start position:0% +spending a lot of time on each one of + + + align:start position:0% +spending a lot of time on each one of +these uh letters and what they represent + + align:start position:0% +these uh letters and what they represent + + + align:start position:0% +these uh letters and what they represent +I'd like to focus more on the + + align:start position:0% +I'd like to focus more on the + + + align:start position:0% +I'd like to focus more on the +concept and that is + + align:start position:0% +concept and that is + + + align:start position:0% +concept and that is +what actually is going on in this in + + align:start position:0% +what actually is going on in this in + + + align:start position:0% +what actually is going on in this in +this core and how does one explain it so + + align:start position:0% +this core and how does one explain it so + + + align:start position:0% +this core and how does one explain it so +if we start up here fast neutrons + + align:start position:0% +if we start up here fast neutrons + + + align:start position:0% +if we start up here fast neutrons +produced by + + align:start position:0% +produced by + + + align:start position:0% +produced by +fision uh by thermal fision and then you + + align:start position:0% +fision uh by thermal fision and then you + + + align:start position:0% +fision uh by thermal fision and then you +add the total number of fast neutrons + + align:start position:0% +add the total number of fast neutrons + + + align:start position:0% +add the total number of fast neutrons +produced these neutrons can in fact + + align:start position:0% +produced these neutrons can in fact + + + align:start position:0% +produced these neutrons can in fact +leak and then you can count the number + + align:start position:0% +leak and then you can count the number + + + align:start position:0% +leak and then you can count the number +of neutrons leaking that are + + align:start position:0% +of neutrons leaking that are + + + align:start position:0% +of neutrons leaking that are +fast and then you look at some of the + + align:start position:0% +fast and then you look at some of the + + + align:start position:0% +fast and then you look at some of the +neutrons that are captured in uranium + + align:start position:0% +neutrons that are captured in uranium + + + align:start position:0% +neutrons that are captured in uranium +238 through a resonance Escape + + align:start position:0% +238 through a resonance Escape + + + align:start position:0% +238 through a resonance Escape +probability ultimately ending up with a + + align:start position:0% +probability ultimately ending up with a + + + align:start position:0% +probability ultimately ending up with a +group of thermalized + + align:start position:0% +group of thermalized + + + align:start position:0% +group of thermalized +neutrons that also have + + align:start position:0% +neutrons that also have + + + align:start position:0% +neutrons that also have +certain probability of leakage from the + + align:start position:0% +certain probability of leakage from the + + + align:start position:0% +certain probability of leakage from the +reactor and and if you as you keep these + + align:start position:0% +reactor and and if you as you keep these + + + align:start position:0% +reactor and and if you as you keep these +neutrons from escaping the leakage they + + align:start position:0% +neutrons from escaping the leakage they + + + align:start position:0% +neutrons from escaping the leakage they +then become available to become absorbed + + align:start position:0% +then become available to become absorbed + + + align:start position:0% +then become available to become absorbed +in uranium + + align:start position:0% +in uranium + + + align:start position:0% +in uranium +238 so this identifies the number of + + align:start position:0% +238 so this identifies the number of + + + align:start position:0% +238 so this identifies the number of +thermal neutrons absorbed in control + + align:start position:0% +thermal neutrons absorbed in control + + + align:start position:0% +thermal neutrons absorbed in control +rods and water now that's sort of the + + align:start position:0% +rods and water now that's sort of the + + + align:start position:0% +rods and water now that's sort of the +thermal utilization so you have neutrons + + align:start position:0% +thermal utilization so you have neutrons + + + align:start position:0% +thermal utilization so you have neutrons +actually getting into the thermal energy + + align:start position:0% +actually getting into the thermal energy + + + align:start position:0% +actually getting into the thermal energy +range and then these neutrons become + + align:start position:0% +range and then these neutrons become + + + align:start position:0% +range and then these neutrons become +absorbed not capable of producing fion + + align:start position:0% +absorbed not capable of producing fion + + + align:start position:0% +absorbed not capable of producing fion +but then you have some neutrons that do + + align:start position:0% +but then you have some neutrons that do + + + align:start position:0% +but then you have some neutrons that do +end up being absorbed in the fuel during + + align:start position:0% +end up being absorbed in the fuel during + + + align:start position:0% +end up being absorbed in the fuel during +the + + align:start position:0% +the + + + align:start position:0% +the +235 and then there's certain likelihood + + align:start position:0% +235 and then there's certain likelihood + + + align:start position:0% +235 and then there's certain likelihood +that some of these neutrons absorbed in + + align:start position:0% +that some of these neutrons absorbed in + + + align:start position:0% +that some of these neutrons absorbed in +the fuel do not fion but ultimately you + + align:start position:0% +the fuel do not fion but ultimately you + + + align:start position:0% +the fuel do not fion but ultimately you +get thermal neutrons which are captured + + align:start position:0% +get thermal neutrons which are captured + + + align:start position:0% +get thermal neutrons which are captured +in the fuel which cause a fision + + align:start position:0% +in the fuel which cause a fision + + + align:start position:0% +in the fuel which cause a fision +producing neutrons hopefully at least + + align:start position:0% +producing neutrons hopefully at least + + + align:start position:0% +producing neutrons hopefully at least +2.5 so if you understand this chart you + + align:start position:0% +2.5 so if you understand this chart you + + + align:start position:0% +2.5 so if you understand this chart you +you'll begin to + + align:start position:0% +you'll begin to + + + align:start position:0% +you'll begin to +appreciate the life of a neutron in in a + + align:start position:0% +appreciate the life of a neutron in in a + + + align:start position:0% +appreciate the life of a neutron in in a +reactive cord and all these things need + + align:start position:0% +reactive cord and all these things need + + + align:start position:0% +reactive cord and all these things need +to be analyzed and understood in a + + align:start position:0% +to be analyzed and understood in a + + + align:start position:0% +to be analyzed and understood in a +reactor physic + + align:start position:0% +reactor physic + + + align:start position:0% +reactor physic +calculation so when you look at some of + + align:start position:0% +calculation so when you look at some of + + + align:start position:0% +calculation so when you look at some of +these Expressions now and this is now + + align:start position:0% +these Expressions now and this is now + + + align:start position:0% +these Expressions now and this is now +the six Factor formula which is the + + align:start position:0% +the six Factor formula which is the + + + align:start position:0% +the six Factor formula which is the +symbol we still use the same symbol K + + align:start position:0% +symbol we still use the same symbol K + + + align:start position:0% +symbol we still use the same symbol K +and without going through all these + + align:start position:0% +and without going through all these + + + align:start position:0% +and without going through all these +terms because they are sometimes tedious + + align:start position:0% +terms because they are sometimes tedious + + + align:start position:0% +terms because they are sometimes tedious +but the functions you've just seen + + align:start position:0% +but the functions you've just seen + + + align:start position:0% +but the functions you've just seen +described above it captures the life + + align:start position:0% +described above it captures the life + + + align:start position:0% +described above it captures the life +cycle of various stages such that the + + align:start position:0% +cycle of various stages such that the + + + align:start position:0% +cycle of various stages such that the +production over losses is equal to + + align:start position:0% +production over losses is equal to + + + align:start position:0% +production over losses is equal to +approximately one and this term which is + + align:start position:0% +approximately one and this term which is + + + align:start position:0% +approximately one and this term which is +the six Factor formula captures absorb + + align:start position:0% +the six Factor formula captures absorb + + + align:start position:0% +the six Factor formula captures absorb +leage over Vision which are produced and + + align:start position:0% +leage over Vision which are produced and + + + align:start position:0% +leage over Vision which are produced and +another way of expressing it is how many + + align:start position:0% +another way of expressing it is how many + + + align:start position:0% +another way of expressing it is how many +neutrons are in this generation as + + align:start position:0% +neutrons are in this generation as + + + align:start position:0% +neutrons are in this generation as +compared to the preceding generation + + align:start position:0% +compared to the preceding generation + + + align:start position:0% +compared to the preceding generation +which is uh if you maintain that to be a + + align:start position:0% +which is uh if you maintain that to be a + + + align:start position:0% +which is uh if you maintain that to be a +constant number when it's Unity the + + align:start position:0% +constant number when it's Unity the + + + align:start position:0% +constant number when it's Unity the +reactor is critical when it's less than + + align:start position:0% +reactor is critical when it's less than + + + align:start position:0% +reactor is critical when it's less than +that the reactor will in fact shut + + align:start position:0% +that the reactor will in fact shut + + + align:start position:0% +that the reactor will in fact shut +down and again here are the + + align:start position:0% +down and again here are the + + + align:start position:0% +down and again here are the +definitions uh that were used in the + + align:start position:0% +definitions uh that were used in the + + + align:start position:0% +definitions uh that were used in the +previous expression + + align:start position:0% +previous expression + + + align:start position:0% +previous expression +uh don't want to go over these at this + + align:start position:0% +uh don't want to go over these at this + + + align:start position:0% +uh don't want to go over these at this +point but you can read them at your + + align:start position:0% +point but you can read them at your + + + align:start position:0% +point but you can read them at your +leisure but these are the important + + align:start position:0% +leisure but these are the important + + + align:start position:0% +leisure but these are the important +Concepts which we just gone + + align:start position:0% +Concepts which we just gone + + + align:start position:0% +Concepts which we just gone +through uh more + + align:start position:0% +through uh more + + + align:start position:0% +through uh more +definitions and um what this term + + align:start position:0% +definitions and um what this term + + + align:start position:0% +definitions and um what this term +basically is is is a is an important one + + align:start position:0% +basically is is is a is an important one + + + align:start position:0% +basically is is is a is an important one +relative to having neutrons that are + + align:start position:0% +relative to having neutrons that are + + + align:start position:0% +relative to having neutrons that are +actually capable of producing the + + align:start position:0% + + + + align:start position:0% + +fishion in terms of uh Neutron loss + + align:start position:0% +fishion in terms of uh Neutron loss + + + align:start position:0% +fishion in terms of uh Neutron loss +mechanisms which are + + align:start position:0% +mechanisms which are + + + align:start position:0% +mechanisms which are +which can be significant these are some + + align:start position:0% +which can be significant these are some + + + align:start position:0% +which can be significant these are some +parameters that one could compare + + align:start position:0% +parameters that one could compare + + + align:start position:0% +parameters that one could compare +remember a neutron is a certain lifetime + + align:start position:0% +remember a neutron is a certain lifetime + + + align:start position:0% +remember a neutron is a certain lifetime +from time it's born to the time T gets + + align:start position:0% +from time it's born to the time T gets + + + align:start position:0% +from time it's born to the time T gets +captured and you can measure that in + + align:start position:0% +captured and you can measure that in + + + align:start position:0% +captured and you can measure that in +distance as well so if a reactor is on + + align:start position:0% +distance as well so if a reactor is on + + + align:start position:0% +distance as well so if a reactor is on +the scale of meters the neutron length + + align:start position:0% +the scale of meters the neutron length + + + align:start position:0% +the scale of meters the neutron length +scale is on the in terms of looks like a + + align:start position:0% +scale is on the in terms of looks like a + + + align:start position:0% +scale is on the in terms of looks like a +thermal Neutron is on the order of a + + align:start position:0% +thermal Neutron is on the order of a + + + align:start position:0% +thermal Neutron is on the order of a +tenth of a meter and as the essentially + + align:start position:0% +tenth of a meter and as the essentially + + + align:start position:0% +tenth of a meter and as the essentially +this scale this grows like if the L go + + align:start position:0% +this scale this grows like if the L go + + + align:start position:0% +this scale this grows like if the L go +get smaller the probability of Escape + + align:start position:0% +get smaller the probability of Escape + + + align:start position:0% +get smaller the probability of Escape +grows which is obvious and also we have + + align:start position:0% +grows which is obvious and also we have + + + align:start position:0% +grows which is obvious and also we have +capture by reactor materials and these + + align:start position:0% +capture by reactor materials and these + + + align:start position:0% +capture by reactor materials and these +materials are in the form of control + + align:start position:0% +materials are in the form of control + + + align:start position:0% +materials are in the form of control +rods which are used to control the + + align:start position:0% +rods which are used to control the + + + align:start position:0% +rods which are used to control the +reaction rate burnable poisons which are + + align:start position:0% +reaction rate burnable poisons which are + + + align:start position:0% +reaction rate burnable poisons which are +used in some reactors to control excess + + align:start position:0% +used in some reactors to control excess + + + align:start position:0% +used in some reactors to control excess +reactivity and obviously structural + + align:start position:0% +reactivity and obviously structural + + + align:start position:0% +reactivity and obviously structural +material such as iron steel zirconium + + align:start position:0% +material such as iron steel zirconium + + + align:start position:0% +material such as iron steel zirconium +from the fuel and the moderator also has + + align:start position:0% +from the fuel and the moderator also has + + + align:start position:0% +from the fuel and the moderator also has +an absorption cross-section that in fact + + align:start position:0% +an absorption cross-section that in fact + + + align:start position:0% +an absorption cross-section that in fact +can be used not only to uh slow down + + align:start position:0% +can be used not only to uh slow down + + + align:start position:0% +can be used not only to uh slow down +neutrons but as a neutron absorber so + + align:start position:0% +neutrons but as a neutron absorber so + + + align:start position:0% +neutrons but as a neutron absorber so +what we have here and and perhaps + + align:start position:0% +what we have here and and perhaps + + + align:start position:0% +what we have here and and perhaps +sometimes the coolant is different than + + align:start position:0% +sometimes the coolant is different than + + + align:start position:0% +sometimes the coolant is different than +the moderator in uh several designs such + + align:start position:0% +the moderator in uh several designs such + + + align:start position:0% +the moderator in uh several designs such +as the MIT + + align:start position:0% +as the MIT + + + align:start position:0% +as the MIT +reactor or a high temperature gas cool + + align:start position:0% +reactor or a high temperature gas cool + + + align:start position:0% +reactor or a high temperature gas cool +reactor where helium is the coolant the + + align:start position:0% +reactor where helium is the coolant the + + + align:start position:0% +reactor where helium is the coolant the +moderator being graphite so with + + align:start position:0% +moderator being graphite so with + + + align:start position:0% +moderator being graphite so with +appreciation of the kinds of things that + + align:start position:0% +appreciation of the kinds of things that + + + align:start position:0% +appreciation of the kinds of things that +take neutrons away from the system you + + align:start position:0% +take neutrons away from the system you + + + align:start position:0% +take neutrons away from the system you +then are in a position to U design a + + align:start position:0% +then are in a position to U design a + + + align:start position:0% +then are in a position to U design a +core now the question for the reactor + + align:start position:0% +core now the question for the reactor + + + align:start position:0% +core now the question for the reactor +designer up first + + align:start position:0% +designer up first + + + align:start position:0% +designer up first +is how long should K be one before you + + align:start position:0% +is how long should K be one before you + + + align:start position:0% +is how long should K be one before you +need to refuel and the choices typically + + align:start position:0% +need to refuel and the choices typically + + + align:start position:0% +need to refuel and the choices typically +people are now making used to be a 12 + + align:start position:0% +people are now making used to be a 12 + + + align:start position:0% +people are now making used to be a 12 +year 12mth annual cycle where the + + align:start position:0% +year 12mth annual cycle where the + + + align:start position:0% +year 12mth annual cycle where the +reactor be shut down refueled and + + align:start position:0% +reactor be shut down refueled and + + + align:start position:0% +reactor be shut down refueled and +operated for 12 months right now reactor + + align:start position:0% +operated for 12 months right now reactor + + + align:start position:0% +operated for 12 months right now reactor +designers are going to much longer time + + align:start position:0% +designers are going to much longer time + + + align:start position:0% +designers are going to much longer time +periods these being 18 to 24 months and + + align:start position:0% +periods these being 18 to 24 months and + + + align:start position:0% +periods these being 18 to 24 months and +the way to do that as as you all realize + + align:start position:0% +the way to do that as as you all realize + + + align:start position:0% +the way to do that as as you all realize +is once a neutron gets absorbed in the + + align:start position:0% +is once a neutron gets absorbed in the + + + align:start position:0% +is once a neutron gets absorbed in the +uranium atom it fions and is no longer + + align:start position:0% +uranium atom it fions and is no longer + + + align:start position:0% +uranium atom it fions and is no longer +capable of producing a fion so that you + + align:start position:0% +capable of producing a fion so that you + + + align:start position:0% +capable of producing a fion so that you +have to load the Reactor with excess + + align:start position:0% +have to load the Reactor with excess + + + align:start position:0% +have to load the Reactor with excess +reactivity to cover the 18 months or 24 + + align:start position:0% +reactivity to cover the 18 months or 24 + + + align:start position:0% +reactivity to cover the 18 months or 24 +months that the reactor might in fact be + + align:start position:0% +months that the reactor might in fact be + + + align:start position:0% +months that the reactor might in fact be +Opera so you put in more fuel more + + align:start position:0% +Opera so you put in more fuel more + + + align:start position:0% +Opera so you put in more fuel more +uranium 235 higher enrichment and you + + align:start position:0% +uranium 235 higher enrichment and you + + + align:start position:0% +uranium 235 higher enrichment and you +need to B balance that excess reactivity + + align:start position:0% +need to B balance that excess reactivity + + + align:start position:0% +need to B balance that excess reactivity +in a number of ways the way one does it + + align:start position:0% +in a number of ways the way one does it + + + align:start position:0% +in a number of ways the way one does it +is for for bwrs they use two things they + + align:start position:0% +is for for bwrs they use two things they + + + align:start position:0% +is for for bwrs they use two things they +use a burnable poison which is a poison + + align:start position:0% +use a burnable poison which is a poison + + + align:start position:0% +use a burnable poison which is a poison +a neutron absorber that you put into the + + align:start position:0% +a neutron absorber that you put into the + + + align:start position:0% +a neutron absorber that you put into the +core with the fuel such that when a + + align:start position:0% +core with the fuel such that when a + + + align:start position:0% +core with the fuel such that when a +neutron is born it hits it rather than a + + align:start position:0% +neutron is born it hits it rather than a + + + align:start position:0% +neutron is born it hits it rather than a +fuel and creates a longer life fuel + + align:start position:0% +fuel and creates a longer life fuel + + + align:start position:0% +fuel and creates a longer life fuel +because the burnable poisons that sort + + align:start position:0% +because the burnable poisons that sort + + + align:start position:0% +because the burnable poisons that sort +of capture excess neutrons without + + align:start position:0% +of capture excess neutrons without + + + align:start position:0% +of capture excess neutrons without +fishing in fuel or you can do it as in a + + align:start position:0% +fishing in fuel or you can do it as in a + + + align:start position:0% +fishing in fuel or you can do it as in a +pwr where they put in what we call + + align:start position:0% +pwr where they put in what we call + + + align:start position:0% +pwr where they put in what we call +soluble Boron which is water is boric + + align:start position:0% +soluble Boron which is water is boric + + + align:start position:0% +soluble Boron which is water is boric +acid essentially put into the cord that + + align:start position:0% +acid essentially put into the cord that + + + align:start position:0% +acid essentially put into the cord that +will be used to and gradually reduced in + + align:start position:0% +will be used to and gradually reduced in + + + align:start position:0% +will be used to and gradually reduced in +concentration as the reactor operates it + + align:start position:0% +concentration as the reactor operates it + + + align:start position:0% +concentration as the reactor operates it +acts as a uniform Neutron absorber that + + align:start position:0% +acts as a uniform Neutron absorber that + + + align:start position:0% +acts as a uniform Neutron absorber that +is in fact the burnable poison and over + + align:start position:0% +is in fact the burnable poison and over + + + align:start position:0% +is in fact the burnable poison and over +time at the end of the the operating + + align:start position:0% +time at the end of the the operating + + + align:start position:0% +time at the end of the the operating +life the Boron concentration is + + align:start position:0% +life the Boron concentration is + + + align:start position:0% +life the Boron concentration is +essentially at zero and the reactor + + align:start position:0% +essentially at zero and the reactor + + + align:start position:0% +essentially at zero and the reactor +slowly begins to shut itself down unless + + align:start position:0% +slowly begins to shut itself down unless + + + align:start position:0% +slowly begins to shut itself down unless +you decide to refuel you can also + + align:start position:0% +you decide to refuel you can also + + + align:start position:0% +you decide to refuel you can also +control excess reactivity by leakage the + + align:start position:0% +control excess reactivity by leakage the + + + align:start position:0% +control excess reactivity by leakage the +reactor can can be designed in such a + + align:start position:0% +reactor can can be designed in such a + + + align:start position:0% +reactor can can be designed in such a +way that has a high leage core and + + align:start position:0% +way that has a high leage core and + + + align:start position:0% +way that has a high leage core and +sometimes that's useful for a reactor + + align:start position:0% +sometimes that's useful for a reactor + + + align:start position:0% +sometimes that's useful for a reactor +design and safety some reactors allow + + align:start position:0% +design and safety some reactors allow + + + align:start position:0% +design and safety some reactors allow +for online refueling in other words they + + align:start position:0% +for online refueling in other words they + + + align:start position:0% +for online refueling in other words they +don't require all this excess reactivity + + align:start position:0% +don't require all this excess reactivity + + + align:start position:0% +don't require all this excess reactivity +in the fuel and in the can do reactor + + align:start position:0% +in the fuel and in the can do reactor + + + align:start position:0% +in the fuel and in the can do reactor +which is the uh Canadian uh essentially + + align:start position:0% +which is the uh Canadian uh essentially + + + align:start position:0% +which is the uh Canadian uh essentially +a natural natural uranium reactor where + + align:start position:0% +a natural natural uranium reactor where + + + align:start position:0% +a natural natural uranium reactor where +they use duum as a + + align:start position:0% +they use duum as a + + + align:start position:0% +they use duum as a +moderator uh and water as a coolant + + align:start position:0% +moderator uh and water as a coolant + + + align:start position:0% +moderator uh and water as a coolant +where they are able to take the fuel + + align:start position:0% +where they are able to take the fuel + + + align:start position:0% +where they are able to take the fuel +assemblies out during operation and load + + align:start position:0% +assemblies out during operation and load + + + align:start position:0% +assemblies out during operation and load +fresh fuel assemblies it's a candria + + align:start position:0% +fresh fuel assemblies it's a candria + + + align:start position:0% +fresh fuel assemblies it's a candria +type reactor or you could have a pebble + + align:start position:0% +type reactor or you could have a pebble + + + align:start position:0% +type reactor or you could have a pebble +bed reactor which is a + + align:start position:0% +bed reactor which is a + + + align:start position:0% +bed reactor which is a +continuously uh flowing not flow but it + + align:start position:0% +continuously uh flowing not flow but it + + + align:start position:0% +continuously uh flowing not flow but it +was a roope let's call a continuous + + align:start position:0% +was a roope let's call a continuous + + + align:start position:0% +was a roope let's call a continuous +flowing of Pebbles that go in and out of + + align:start position:0% +flowing of Pebbles that go in and out of + + + align:start position:0% +flowing of Pebbles that go in and out of +the reactor over time to make up the + + align:start position:0% +the reactor over time to make up the + + + align:start position:0% +the reactor over time to make up the +excess reactivity so once the pebble is + + align:start position:0% +excess reactivity so once the pebble is + + + align:start position:0% +excess reactivity so once the pebble is +depleted it can be put a fresh Pebble + + align:start position:0% +depleted it can be put a fresh Pebble + + + align:start position:0% +depleted it can be put a fresh Pebble +can be put in or it can be recirculated + + align:start position:0% +can be put in or it can be recirculated + + + align:start position:0% +can be put in or it can be recirculated +back in the reactor if this burn up + + align:start position:0% +back in the reactor if this burn up + + + align:start position:0% +back in the reactor if this burn up +isn't isn't uh isn't all uh used up the + + align:start position:0% +isn't isn't uh isn't all uh used up the + + + align:start position:0% +isn't isn't uh isn't all uh used up the +fuel isn't all used + + align:start position:0% +fuel isn't all used + + + align:start position:0% +fuel isn't all used +up let me now touch a little bit on on + + align:start position:0% +up let me now touch a little bit on on + + + align:start position:0% +up let me now touch a little bit on on +diffusion Theory because this is this is + + align:start position:0% +diffusion Theory because this is this is + + + align:start position:0% +diffusion Theory because this is this is +sort of the the way people normally uh + + align:start position:0% +sort of the the way people normally uh + + + align:start position:0% +sort of the the way people normally uh +do reactor + + align:start position:0% +do reactor + + + align:start position:0% +do reactor +analysis and diffusion theory has as its + + align:start position:0% +analysis and diffusion theory has as its + + + align:start position:0% +analysis and diffusion theory has as its +basis U some fundamentals that we will + + align:start position:0% +basis U some fundamentals that we will + + + align:start position:0% +basis U some fundamentals that we will +just quickly go over + + align:start position:0% +just quickly go over + + + align:start position:0% +just quickly go over +here okay now we're going to talk about + + align:start position:0% +here okay now we're going to talk about + + + align:start position:0% +here okay now we're going to talk about +uh diffusion Theory and this is how we + + align:start position:0% +uh diffusion Theory and this is how we + + + align:start position:0% +uh diffusion Theory and this is how we +in fact keep track of neutrons in terms + + align:start position:0% +in fact keep track of neutrons in terms + + + align:start position:0% +in fact keep track of neutrons in terms +of production and destruction and Le + + align:start position:0% +of production and destruction and Le + + + align:start position:0% +of production and destruction and Le +and it's essentially a neutron balance + + align:start position:0% +and it's essentially a neutron balance + + + align:start position:0% +and it's essentially a neutron balance +for a critical reactor and it does + + align:start position:0% +for a critical reactor and it does + + + align:start position:0% +for a critical reactor and it does +consider all of these phenomena and you + + align:start position:0% +consider all of these phenomena and you + + + align:start position:0% +consider all of these phenomena and you +have you can do it in one group Theory + + align:start position:0% +have you can do it in one group Theory + + + align:start position:0% +have you can do it in one group Theory +or multi-group Theory now one group + + align:start position:0% +or multi-group Theory now one group + + + align:start position:0% +or multi-group Theory now one group +Theory assumes that the neutron energy + + align:start position:0% +Theory assumes that the neutron energy + + + align:start position:0% +Theory assumes that the neutron energy +and everything's going on at one energy + + align:start position:0% +and everything's going on at one energy + + + align:start position:0% +and everything's going on at one energy +that one ener for our selection and the + + align:start position:0% +that one ener for our selection and the + + + align:start position:0% +that one ener for our selection and the +thermal the thermal energies and we have + + align:start position:0% +thermal the thermal energies and we have + + + align:start position:0% +thermal the thermal energies and we have +to make some + + align:start position:0% +to make some + + + align:start position:0% +to make some +adjustments and multi-group allows for a + + align:start position:0% +adjustments and multi-group allows for a + + + align:start position:0% +adjustments and multi-group allows for a +little more sophisticated treatment we + + align:start position:0% +little more sophisticated treatment we + + + align:start position:0% +little more sophisticated treatment we +take the say the 2 me down to + + align:start position:0% +take the say the 2 me down to + + + align:start position:0% +take the say the 2 me down to +essentially a thermal energy range and + + align:start position:0% +essentially a thermal energy range and + + + align:start position:0% +essentially a thermal energy range and +we decide what energy levels and what + + align:start position:0% +we decide what energy levels and what + + + align:start position:0% +we decide what energy levels and what +how many groups do we need to properly + + align:start position:0% +how many groups do we need to properly + + + align:start position:0% +how many groups do we need to properly +characterize the slowing down the + + align:start position:0% +characterize the slowing down the + + + align:start position:0% +characterize the slowing down the +absorptions at various energy levels and + + align:start position:0% +absorptions at various energy levels and + + + align:start position:0% +absorptions at various energy levels and +as you can recall we had the high energy + + align:start position:0% +as you can recall we had the high energy + + + align:start position:0% +as you can recall we had the high energy +level where there was the Visions + + align:start position:0% +level where there was the Visions + + + align:start position:0% +level where there was the Visions +occurring we had a resonance region and + + align:start position:0% +occurring we had a resonance region and + + + align:start position:0% +occurring we had a resonance region and +then we had a thermal region most people + + align:start position:0% +then we had a thermal region most people + + + align:start position:0% +then we had a thermal region most people +do analysis likely number of groups + + align:start position:0% +do analysis likely number of groups + + + align:start position:0% +do analysis likely number of groups +could be like 30 or so to properly + + align:start position:0% +could be like 30 or so to properly + + + align:start position:0% +could be like 30 or so to properly +capture what might be going on in a + + align:start position:0% +capture what might be going on in a + + + align:start position:0% +capture what might be going on in a +reactor but many analyses are quite fine + + align:start position:0% +reactor but many analyses are quite fine + + + align:start position:0% +reactor but many analyses are quite fine +with four group energies but let me + + align:start position:0% +with four group energies but let me + + + align:start position:0% +with four group energies but let me +start now with the fundamentals of + + align:start position:0% +start now with the fundamentals of + + + align:start position:0% +start now with the fundamentals of +diffusion Theory and I'm going to go + + align:start position:0% +diffusion Theory and I'm going to go + + + align:start position:0% +diffusion Theory and I'm going to go +going to go to the board here for a + + align:start position:0% +going to go to the board here for a + + + align:start position:0% +going to go to the board here for a +moment and um lay out what why people + + align:start position:0% +moment and um lay out what why people + + + align:start position:0% +moment and um lay out what why people +call it diffusion Theory and what + + align:start position:0% +call it diffusion Theory and what + + + align:start position:0% +call it diffusion Theory and what +actually + + align:start position:0% +actually + + + align:start position:0% +actually +means okay now we're going to talk about + + align:start position:0% +means okay now we're going to talk about + + + align:start position:0% +means okay now we're going to talk about +one one group diffus us + + align:start position:0% + + + + align:start position:0% + +Theory and we're going to explain a bit + + align:start position:0% +Theory and we're going to explain a bit + + + align:start position:0% +Theory and we're going to explain a bit +about how why we call it diffusion + + align:start position:0% +about how why we call it diffusion + + + align:start position:0% +about how why we call it diffusion +Theory now typically a + + align:start position:0% +Theory now typically a + + + align:start position:0% +Theory now typically a +neutron is born and it has many + + align:start position:0% +neutron is born and it has many + + + align:start position:0% +neutron is born and it has many +possibilities and and and the + + align:start position:0% +possibilities and and and the + + + align:start position:0% +possibilities and and and the +possibilities are it has a certain + + align:start position:0% +possibilities are it has a certain + + + align:start position:0% +possibilities are it has a certain +energy level as we saw in the and the + + align:start position:0% +energy level as we saw in the and the + + + align:start position:0% +energy level as we saw in the and the +the the spectrum of energy produced as a + + align:start position:0% +the the spectrum of energy produced as a + + + align:start position:0% +the the spectrum of energy produced as a +function efficient it is going in a + + align:start position:0% +function efficient it is going in a + + + align:start position:0% +function efficient it is going in a +certain + + align:start position:0% +certain + + + align:start position:0% +certain +direction which is sort of the + + align:start position:0% +direction which is sort of the + + + align:start position:0% +direction which is sort of the +Omega and this energy can be + + align:start position:0% +Omega and this energy can be + + + align:start position:0% +Omega and this energy can be +characterized as a velocity which means + + align:start position:0% +characterized as a velocity which means + + + align:start position:0% +characterized as a velocity which means +it's going at a certain speed and it's + + align:start position:0% +it's going at a certain speed and it's + + + align:start position:0% +it's going at a certain speed and it's +located at a certain point and it's + + align:start position:0% +located at a certain point and it's + + + align:start position:0% +located at a certain point and it's +created at a certain + + align:start position:0% +created at a certain + + + align:start position:0% +created at a certain +time and and it's po probability of + + align:start position:0% +time and and it's po probability of + + + align:start position:0% +time and and it's po probability of +interacting with something else within a + + align:start position:0% +interacting with something else within a + + + align:start position:0% +interacting with something else within a +certain + + align:start position:0% +certain + + + align:start position:0% +certain +distance we call that a cross-section + + align:start position:0% +distance we call that a cross-section + + + align:start position:0% +distance we call that a cross-section +which is the microscopic cross-section + + align:start position:0% +which is the microscopic cross-section + + + align:start position:0% +which is the microscopic cross-section +which as I as we mentioned before is it + + align:start position:0% +which as I as we mentioned before is it + + + align:start position:0% +which as I as we mentioned before is it +could be absorption capture Vision + + align:start position:0% +could be absorption capture Vision + + + align:start position:0% +could be absorption capture Vision +scatter so a + + align:start position:0% +scatter so a + + + align:start position:0% +scatter so a +neutron is challenged if you will + + align:start position:0% +neutron is challenged if you will + + + align:start position:0% +neutron is challenged if you will +because once it's born we're not exactly + + align:start position:0% +because once it's born we're not exactly + + + align:start position:0% +because once it's born we're not exactly +sure which way it's going to go we kind + + align:start position:0% +sure which way it's going to go we kind + + + align:start position:0% +sure which way it's going to go we kind +of know where it is because that where + + align:start position:0% +of know where it is because that where + + + align:start position:0% +of know where it is because that where +it's B because that's where the uranium + + align:start position:0% +it's B because that's where the uranium + + + align:start position:0% +it's B because that's where the uranium +has to be we can more or less guess at + + align:start position:0% +has to be we can more or less guess at + + + align:start position:0% +has to be we can more or less guess at +the time and how long it might survive + + align:start position:0% +the time and how long it might survive + + + align:start position:0% +the time and how long it might survive +before it's either captured scattered or + + align:start position:0% +before it's either captured scattered or + + + align:start position:0% +before it's either captured scattered or +absorbed but all this stuff these These + + align:start position:0% +absorbed but all this stuff these These + + + align:start position:0% +absorbed but all this stuff these These +cross-sections are are measured as a + + align:start position:0% +cross-sections are are measured as a + + + align:start position:0% +cross-sections are are measured as a +function of energy they're measured as a + + align:start position:0% +function of energy they're measured as a + + + align:start position:0% +function of energy they're measured as a +as as a function of of U actually the + + align:start position:0% +as as a function of of U actually the + + + align:start position:0% +as as a function of of U actually the +the neutron energy and which is a + + align:start position:0% +the neutron energy and which is a + + + align:start position:0% +the neutron energy and which is a +function of the temperature of the + + align:start position:0% +function of the temperature of the + + + align:start position:0% +function of the temperature of the +particular + + align:start position:0% +particular + + + align:start position:0% +particular +medium so with this basic information + + align:start position:0% +medium so with this basic information + + + align:start position:0% +medium so with this basic information +we're going to try to collapse it down + + align:start position:0% +we're going to try to collapse it down + + + align:start position:0% +we're going to try to collapse it down +to something that assumes it's one + + align:start position:0% +to something that assumes it's one + + + align:start position:0% +to something that assumes it's one +speed essentially going in a direction + + align:start position:0% +speed essentially going in a direction + + + align:start position:0% +speed essentially going in a direction +maybe it's a universal Direction but + + align:start position:0% +maybe it's a universal Direction but + + + align:start position:0% +maybe it's a universal Direction but +we're not going to be all that sensitive + + align:start position:0% +we're not going to be all that sensitive + + + align:start position:0% +we're not going to be all that sensitive +to it in in diffusion Theory but we are + + align:start position:0% +to it in in diffusion Theory but we are + + + align:start position:0% +to it in in diffusion Theory but we are +going to be sensitive to its + + align:start position:0% +going to be sensitive to its + + + align:start position:0% +going to be sensitive to its +location and the material that the + + align:start position:0% +location and the material that the + + + align:start position:0% +location and the material that the +neutron will see during its uh + + align:start position:0% +neutron will see during its uh + + + align:start position:0% +neutron will see during its uh +lifetime so when when we try to write + + align:start position:0% +lifetime so when when we try to write + + + align:start position:0% +lifetime so when when we try to write +this expression + + align:start position:0% +this expression + + + align:start position:0% +this expression +we look at if you will a term that we + + align:start position:0% +we look at if you will a term that we + + + align:start position:0% +we look at if you will a term that we +just like to describe perhaps not + + align:start position:0% +just like to describe perhaps not + + + align:start position:0% +just like to describe perhaps not +appropriately but it's called Neutron + + align:start position:0% +appropriately but it's called Neutron + + + align:start position:0% +appropriately but it's called Neutron +leakage + + align:start position:0% +leakage + + + align:start position:0% +leakage +uh for + + align:start position:0% + + + + align:start position:0% + +travel through am + + align:start position:0% + + + + align:start position:0% + +medium a medium and and and what that + + align:start position:0% +medium a medium and and and what that + + + align:start position:0% +medium a medium and and and what that +basically means is if a neutron is born + + align:start position:0% +basically means is if a neutron is born + + + align:start position:0% +basically means is if a neutron is born +here it's going to + + align:start position:0% +here it's going to + + + align:start position:0% +here it's going to +go from here to here leaking out of a + + align:start position:0% +go from here to here leaking out of a + + + align:start position:0% +go from here to here leaking out of a +certain confined space and the way we do + + align:start position:0% +certain confined space and the way we do + + + align:start position:0% +certain confined space and the way we do +that is we establish and we use what we + + align:start position:0% +that is we establish and we use what we + + + align:start position:0% +that is we establish and we use what we +call fixed + + align:start position:0% + + + + align:start position:0% + +law law of + + align:start position:0% + + + + align:start position:0% + +diffusion which is a + + align:start position:0% +diffusion which is a + + + align:start position:0% +diffusion which is a +simplification of all of the phenomena + + align:start position:0% +simplification of all of the phenomena + + + align:start position:0% +simplification of all of the phenomena +that this poor Neutron is going to have + + align:start position:0% +that this poor Neutron is going to have + + + align:start position:0% +that this poor Neutron is going to have +c as it tries to go from point A to + + align:start position:0% +c as it tries to go from point A to + + + align:start position:0% +c as it tries to go from point A to +point + + align:start position:0% +point + + + align:start position:0% +point +B and we just find this if you will + + align:start position:0% +B and we just find this if you will + + + align:start position:0% +B and we just find this if you will +current or Neutron + + align:start position:0% +current or Neutron + + + align:start position:0% +current or Neutron +current as a term which has a diffusion + + align:start position:0% +current as a term which has a diffusion + + + align:start position:0% +current as a term which has a diffusion +coefficient as a function of the + + align:start position:0% +coefficient as a function of the + + + align:start position:0% +coefficient as a function of the +gradient of the flux of neutrons at that + + align:start position:0% +gradient of the flux of neutrons at that + + + align:start position:0% +gradient of the flux of neutrons at that +position + + align:start position:0% +position + + + align:start position:0% +position +R so this D + + align:start position:0% +R so this D + + + align:start position:0% +R so this D +represents a mixture of absorption + + align:start position:0% +represents a mixture of absorption + + + align:start position:0% +represents a mixture of absorption +scattering + + align:start position:0% +scattering + + + align:start position:0% +scattering +materials and this D allows one to say + + align:start position:0% +materials and this D allows one to say + + + align:start position:0% +materials and this D allows one to say +all right in this area here the neutron + + align:start position:0% +all right in this area here the neutron + + + align:start position:0% +all right in this area here the neutron +is going to be exposed to certain + + align:start position:0% +is going to be exposed to certain + + + align:start position:0% +is going to be exposed to certain +hazards if you will and if it survives + + align:start position:0% +hazards if you will and if it survives + + + align:start position:0% +hazards if you will and if it survives +those Hazard and comes out the other + + align:start position:0% +those Hazard and comes out the other + + + align:start position:0% +those Hazard and comes out the other +side uh we can arguably say that the + + align:start position:0% +side uh we can arguably say that the + + + align:start position:0% +side uh we can arguably say that the +phenomenon that that neutron has gone + + align:start position:0% +phenomenon that that neutron has gone + + + align:start position:0% +phenomenon that that neutron has gone +through is called diffusion and that's + + align:start position:0% +through is called diffusion and that's + + + align:start position:0% +through is called diffusion and that's +why this diff fixed law of diffusion + + align:start position:0% +why this diff fixed law of diffusion + + + align:start position:0% +why this diff fixed law of diffusion +applies + + align:start position:0% +applies + + + align:start position:0% +applies +and the + + align:start position:0% +and the + + + align:start position:0% +and the +gradient of the flux and the flux + + align:start position:0% + + + + align:start position:0% + +recall is the number of neutrons going + + align:start position:0% +recall is the number of neutrons going + + + align:start position:0% +recall is the number of neutrons going +at a certain + + align:start position:0% +at a certain + + + align:start position:0% +at a certain +velocity at location + + align:start position:0% +velocity at location + + + align:start position:0% +velocity at location +R and it's the gradient is is is the + + align:start position:0% +R and it's the gradient is is is the + + + align:start position:0% +R and it's the gradient is is is the +determining factor in terms of how many + + align:start position:0% +determining factor in terms of how many + + + align:start position:0% +determining factor in terms of how many +neutrons actually end up Surviving this + + align:start position:0% +neutrons actually end up Surviving this + + + align:start position:0% +neutrons actually end up Surviving this +path so if you would run + + align:start position:0% +path so if you would run + + + align:start position:0% +path so if you would run +the leakage + + align:start position:0% +the leakage + + + align:start position:0% +the leakage +expression by + + align:start position:0% + + + + align:start position:0% + +itself which is the gradient of the + + align:start position:0% + + + + align:start position:0% + +current it ends up being minus + + align:start position:0% +current it ends up being minus + + + align:start position:0% +current it ends up being minus +d double + + align:start position:0% + + + + align:start position:0% + +gradient of + + align:start position:0% +gradient of + + + align:start position:0% +gradient of +R so if we take this term as the leakage + + align:start position:0% +R so if we take this term as the leakage + + + align:start position:0% +R so if we take this term as the leakage +term + + align:start position:0% +term + + + align:start position:0% +term +we then can can essentially identify for + + align:start position:0% +we then can can essentially identify for + + + align:start position:0% +we then can can essentially identify for +certain geometries and let's just say a + + align:start position:0% +certain geometries and let's just say a + + + align:start position:0% +certain geometries and let's just say a +slab geometry where you have a slab + + align:start position:0% +slab geometry where you have a slab + + + align:start position:0% +slab geometry where you have a slab +where a neutron will be coming say this + + align:start position:0% +where a neutron will be coming say this + + + align:start position:0% +where a neutron will be coming say this +way and coming out this + + align:start position:0% +way and coming out this + + + align:start position:0% +way and coming out this +way we will be able to identify that the + + align:start position:0% +way we will be able to identify that the + + + align:start position:0% +way we will be able to identify that the +and this is the X + + align:start position:0% +and this is the X + + + align:start position:0% +and this is the X +Dimension + + align:start position:0% +Dimension + + + align:start position:0% +Dimension +J of X is = to minus d + + align:start position:0% +J of X is = to minus d + + + align:start position:0% +J of X is = to minus d +the gradient of the flux or the first + + align:start position:0% +the gradient of the flux or the first + + + align:start position:0% +the gradient of the flux or the first +Dera of the flux and the + + align:start position:0% + + + + align:start position:0% + +leakage would + + align:start position:0% +leakage would + + + align:start position:0% +leakage would +be second + + align:start position:0% + + + + align:start position:0% + +derivative of the + + align:start position:0% +derivative of the + + + align:start position:0% +derivative of the +BLS so having having defined these + + align:start position:0% +BLS so having having defined these + + + align:start position:0% +BLS so having having defined these +fundamentals we can then + + align:start position:0% +fundamentals we can then + + + align:start position:0% +fundamentals we can then +describe what a neutron and balance + + align:start position:0% +describe what a neutron and balance + + + align:start position:0% +describe what a neutron and balance +equation might look + + align:start position:0% + + + + align:start position:0% + +like so if we write the fundamental + + align:start position:0% +like so if we write the fundamental + + + align:start position:0% +like so if we write the fundamental +equation + + align:start position:0% +equation + + + align:start position:0% +equation +down + + align:start position:0% +down + + + align:start position:0% +down +reduction for Neutron balance now this + + align:start position:0% +reduction for Neutron balance now this + + + align:start position:0% +reduction for Neutron balance now this +is a neutron balance + + align:start position:0% + + + + align:start position:0% + +equation we have production + + align:start position:0% +equation we have production + + + align:start position:0% +equation we have production +equals + + align:start position:0% + + + + align:start position:0% + +absorption plus + + align:start position:0% + + + + align:start position:0% + +leakage now the production term is + + align:start position:0% +leakage now the production term is + + + align:start position:0% +leakage now the production term is +relatively + + align:start position:0% +relatively + + + align:start position:0% +relatively +straightforward number of neutrons + + align:start position:0% +straightforward number of neutrons + + + align:start position:0% +straightforward number of neutrons +produced per fision times the macroscop + + align:start position:0% +produced per fision times the macroscop + + + align:start position:0% +produced per fision times the macroscop +visent cross-section times the flux + + align:start position:0% + + + + align:start position:0% + +put it as a function of r if you + + align:start position:0% + + + + align:start position:0% + +like in one + + align:start position:0% +like in one + + + align:start position:0% +like in one +group The absorption term also is + + align:start position:0% +group The absorption term also is + + + align:start position:0% +group The absorption term also is +relatively + + align:start position:0% + + + + align:start position:0% + +straightforward macroscopic absorption + + align:start position:0% +straightforward macroscopic absorption + + + align:start position:0% +straightforward macroscopic absorption +cross-section times + + align:start position:0% +cross-section times + + + align:start position:0% +cross-section times +the + + align:start position:0% +the + + + align:start position:0% +the +flux and the leage term which we just + + align:start position:0% +flux and the leage term which we just + + + align:start position:0% +flux and the leage term which we just +written + + align:start position:0% + + + + align:start position:0% + +down is this term + + align:start position:0% + + + + align:start position:0% + +so if + + align:start position:0% +so if + + + align:start position:0% +so if +you + + align:start position:0% +you + + + align:start position:0% +you +understand that the macroscopic + + align:start position:0% +understand that the macroscopic + + + align:start position:0% +understand that the macroscopic +cross-section say for fision is a number + + align:start position:0% +cross-section say for fision is a number + + + align:start position:0% +cross-section say for fision is a number +of uranium 235 + + align:start position:0% +of uranium 235 + + + align:start position:0% +of uranium 235 +atoms times the the cross-section for + + align:start position:0% +atoms times the the cross-section for + + + align:start position:0% +atoms times the the cross-section for +vision for + + align:start position:0% +vision for + + + align:start position:0% +vision for +u235 you have Define this term quite + + align:start position:0% +u235 you have Define this term quite + + + align:start position:0% +u235 you have Define this term quite +well this term is a is the macroscopic + + align:start position:0% +well this term is a is the macroscopic + + + align:start position:0% +well this term is a is the macroscopic +absorption cross-section of all the + + align:start position:0% +absorption cross-section of all the + + + align:start position:0% +absorption cross-section of all the +materials + + align:start position:0% + + + + align:start position:0% + +in the reactor and this is the leakage + + align:start position:0% +in the reactor and this is the leakage + + + align:start position:0% +in the reactor and this is the leakage +term that would suggest that depending + + align:start position:0% +term that would suggest that depending + + + align:start position:0% +term that would suggest that depending +upon the gradient of the flux you'll + + align:start position:0% +upon the gradient of the flux you'll + + + align:start position:0% +upon the gradient of the flux you'll +have a certain amount of leakage and + + align:start position:0% +have a certain amount of leakage and + + + align:start position:0% +have a certain amount of leakage and +this diffusion coefficient will Define + + align:start position:0% +this diffusion coefficient will Define + + + align:start position:0% +this diffusion coefficient will Define +in a few + + align:start position:0% + + + + align:start position:0% + +moments if you rewrite this + + align:start position:0% +moments if you rewrite this + + + align:start position:0% +moments if you rewrite this +expression in terms + + align:start position:0% +expression in terms + + + align:start position:0% +expression in terms +of let's just + + align:start position:0% +of let's just + + + align:start position:0% +of let's just +say uh move + + align:start position:0% +say uh move + + + align:start position:0% +say uh move +this + + align:start position:0% +this + + + align:start position:0% +this +over to one side you will have the + + align:start position:0% +over to one side you will have the + + + align:start position:0% +over to one side you will have the +following + + align:start position:0% +following + + + align:start position:0% +following +expression the gr the + + align:start position:0% +expression the gr the + + + align:start position:0% +expression the gr the +gradient of the + + align:start position:0% +gradient of the + + + align:start position:0% +gradient of the +flux + + align:start position:0% +flux + + + align:start position:0% +flux +oops + + align:start position:0% +oops + + + align:start position:0% +oops +plus new Sigma + + align:start position:0% +plus new Sigma + + + align:start position:0% +plus new Sigma +F minus Sigma + + align:start position:0% + + + + align:start position:0% + +a / + + align:start position:0% +a / + + + align:start position:0% +a / +D equals z so we moved things from this + + align:start position:0% +D equals z so we moved things from this + + + align:start position:0% +D equals z so we moved things from this +side over to this side I just sort of + + align:start position:0% +side over to this side I just sort of + + + align:start position:0% +side over to this side I just sort of +flipped the zero + + align:start position:0% +flipped the zero + + + align:start position:0% +flipped the zero +on this term + + align:start position:0% + + + + align:start position:0% + +here is + + align:start position:0% +here is + + + align:start position:0% +here is +called the material + + align:start position:0% + + + + align:start position:0% + +buckling and you can see why because it + + align:start position:0% +buckling and you can see why because it + + + align:start position:0% +buckling and you can see why because it +is completely driven by the materials in + + align:start position:0% +is completely driven by the materials in + + + align:start position:0% +is completely driven by the materials in +the + + align:start position:0% +the + + + align:start position:0% +the +core in terms of the cross-sections and + + align:start position:0% +core in terms of the cross-sections and + + + align:start position:0% +core in terms of the cross-sections and +the number densities of the various + + align:start position:0% + + + + align:start position:0% + +materials so rewriting this + + align:start position:0% +materials so rewriting this + + + align:start position:0% +materials so rewriting this +expression and somewhat simplifying it + + align:start position:0% +expression and somewhat simplifying it + + + align:start position:0% +expression and somewhat simplifying it +you have the gradient of the + + align:start position:0% +you have the gradient of the + + + align:start position:0% +you have the gradient of the +flux plus b + + align:start position:0% +flux plus b + + + align:start position:0% +flux plus b +m² of the flux equals + + align:start position:0% + + + + align:start position:0% + +z that's the neutron balance + + align:start position:0% +z that's the neutron balance + + + align:start position:0% +z that's the neutron balance +equation if you want to represent it in + + align:start position:0% +equation if you want to represent it in + + + align:start position:0% +equation if you want to represent it in +term terms of + + align:start position:0% +term terms of + + + align:start position:0% +term terms of +material in terms of the + + align:start position:0% + + + + align:start position:0% + +materials now to + + align:start position:0% +materials now to + + + align:start position:0% +materials now to +solve this + + align:start position:0% +solve this + + + align:start position:0% +solve this +expression for a what we call it a + + align:start position:0% +expression for a what we call it a + + + align:start position:0% +expression for a what we call it a +bare + + align:start position:0% + + + + align:start position:0% + +critical + + align:start position:0% + + + + align:start position:0% + +system this expression also has a + + align:start position:0% +system this expression also has a + + + align:start position:0% +system this expression also has a +mathematical + + align:start position:0% +mathematical + + + align:start position:0% +mathematical +solution with a certain boundary + + align:start position:0% + + + + align:start position:0% + +condition where we can just assume for + + align:start position:0% +condition where we can just assume for + + + align:start position:0% +condition where we can just assume for +the sake of argument that the flux + + align:start position:0% +the sake of argument that the flux + + + align:start position:0% +the sake of argument that the flux +equals zero at boundary of the + + align:start position:0% + + + + align:start position:0% + +system okay and if you do + + align:start position:0% +system okay and if you do + + + align:start position:0% +system okay and if you do +that you will be Bas basically be able + + align:start position:0% +that you will be Bas basically be able + + + align:start position:0% +that you will be Bas basically be able +to go to the next slide here which gives + + align:start position:0% +to go to the next slide here which gives + + + align:start position:0% +to go to the next slide here which gives +you some standard Solutions + + align:start position:0% + + + + align:start position:0% + +for typical shapes so when we try to + + align:start position:0% +for typical shapes so when we try to + + + align:start position:0% +for typical shapes so when we try to +solve that Neutron balance equation + + align:start position:0% +solve that Neutron balance equation + + + align:start position:0% +solve that Neutron balance equation +expressed in this gradient form and we + + align:start position:0% +expressed in this gradient form and we + + + align:start position:0% +expressed in this gradient form and we +assume that the reactor is a + + align:start position:0% +assume that the reactor is a + + + align:start position:0% +assume that the reactor is a +sphere of radius R the normalized flux + + align:start position:0% +sphere of radius R the normalized flux + + + align:start position:0% +sphere of radius R the normalized flux +the F subr over the the flux of the + + align:start position:0% +the F subr over the the flux of the + + + align:start position:0% +the F subr over the the flux of the +center can be expressed in this term and + + align:start position:0% +center can be expressed in this term and + + + align:start position:0% +center can be expressed in this term and +there's a term that's introduced here + + align:start position:0% +there's a term that's introduced here + + + align:start position:0% +there's a term that's introduced here +called the G ometric buckling which is + + align:start position:0% +called the G ometric buckling which is + + + align:start position:0% +called the G ometric buckling which is +analogous to the material buckling that + + align:start position:0% +analogous to the material buckling that + + + align:start position:0% +analogous to the material buckling that +we Define there and that material the + + align:start position:0% +we Define there and that material the + + + align:start position:0% +we Define there and that material the +geometric buckling has a Pi / R 2 + + align:start position:0% +geometric buckling has a Pi / R 2 + + + align:start position:0% +geometric buckling has a Pi / R 2 +solution if you go to a finite cylinder + + align:start position:0% +solution if you go to a finite cylinder + + + align:start position:0% +solution if you go to a finite cylinder +which means it has uh top and bottom the + + align:start position:0% +which means it has uh top and bottom the + + + align:start position:0% +which means it has uh top and bottom the +radius R height centered about zal 0 and + + align:start position:0% +radius R height centered about zal 0 and + + + align:start position:0% +radius R height centered about zal 0 and +plus h you know goes up and down by a + + align:start position:0% +plus h you know goes up and down by a + + + align:start position:0% +plus h you know goes up and down by a +half it has a vessel function solution + + align:start position:0% +half it has a vessel function solution + + + align:start position:0% +half it has a vessel function solution +and I would refer you to the text on + + align:start position:0% +and I would refer you to the text on + + + align:start position:0% +and I would refer you to the text on +solving these equations for this + + align:start position:0% +solving these equations for this + + + align:start position:0% +solving these equations for this +particular geometry to develop this + + align:start position:0% +particular geometry to develop this + + + align:start position:0% +particular geometry to develop this +vessel function and also it has a + + align:start position:0% +vessel function and also it has a + + + align:start position:0% +vessel function and also it has a +geometric qu if you go to infinite + + align:start position:0% +geometric qu if you go to infinite + + + align:start position:0% +geometric qu if you go to infinite +cylinder it's it's a simpler vessel + + align:start position:0% +cylinder it's it's a simpler vessel + + + align:start position:0% +cylinder it's it's a simpler vessel +function and if you go to an infinite + + align:start position:0% +function and if you go to an infinite + + + align:start position:0% +function and if you go to an infinite +slab it has a cosine type shape uh but + + align:start position:0% +slab it has a cosine type shape uh but + + + align:start position:0% +slab it has a cosine type shape uh but +one of the things that very interesting + + align:start position:0% +one of the things that very interesting + + + align:start position:0% +one of the things that very interesting +about the mathematical solution which + + align:start position:0% +about the mathematical solution which + + + align:start position:0% +about the mathematical solution which +this is compared to the + + align:start position:0% + + + + align:start position:0% + +uh sort of the material solution as + + align:start position:0% +uh sort of the material solution as + + + align:start position:0% +uh sort of the material solution as +expressed by the material buckling is + + align:start position:0% +expressed by the material buckling is + + + align:start position:0% +expressed by the material buckling is +for a critical + + align:start position:0% +for a critical + + + align:start position:0% +for a critical +reactor the material buckling must equal + + align:start position:0% +reactor the material buckling must equal + + + align:start position:0% +reactor the material buckling must equal +the geometric + + align:start position:0% +the geometric + + + align:start position:0% +the geometric +buckling and this is this is how the two + + align:start position:0% +buckling and this is this is how the two + + + align:start position:0% +buckling and this is this is how the two +are in fact + + align:start position:0% +are in fact + + + align:start position:0% +are in fact +linked so for critical + + align:start position:0% + + + + align:start position:0% + +system for critical + + align:start position:0% + + + + align:start position:0% + +system B + + align:start position:0% +system B + + + align:start position:0% +system B +m² must equal b g squar for whatever + + align:start position:0% +m² must equal b g squar for whatever + + + align:start position:0% +m² must equal b g squar for whatever +configuration that we're talking + + align:start position:0% + + + + align:start position:0% + +about which can be very useful in + + align:start position:0% +about which can be very useful in + + + align:start position:0% +about which can be very useful in +solving some of these + + align:start position:0% +solving some of these + + + align:start position:0% +solving some of these +equations so if you then look at how are + + align:start position:0% +equations so if you then look at how are + + + align:start position:0% +equations so if you then look at how are +we going to manipulate these equations + + align:start position:0% +we going to manipulate these equations + + + align:start position:0% +we going to manipulate these equations +to + + align:start position:0% +to + + + align:start position:0% +to +populate uh K + + align:start position:0% +populate uh K + + + align:start position:0% +populate uh K +effective let + + align:start position:0% +effective let + + + align:start position:0% +effective let +me take the next + + align:start position:0% + + + + align:start position:0% + +step so if you then take and and work + + align:start position:0% +step so if you then take and and work + + + align:start position:0% +step so if you then take and and work +with some of these + + align:start position:0% +with some of these + + + align:start position:0% +with some of these +equations and you rewrite them in the + + align:start position:0% +equations and you rewrite them in the + + + align:start position:0% +equations and you rewrite them in the +sense of K + + align:start position:0% +sense of K + + + align:start position:0% +sense of K +equaling one which equals + + align:start position:0% + + + + align:start position:0% + +production divided by absorption plus + + align:start position:0% + + + + align:start position:0% + +leakage using these + + align:start position:0% +leakage using these + + + align:start position:0% +leakage using these +equations what we can + + align:start position:0% +equations what we can + + + align:start position:0% +equations what we can +get is is the following + + align:start position:0% +get is is the following + + + align:start position:0% +get is is the following +expression new Sigma + + align:start position:0% +expression new Sigma + + + align:start position:0% +expression new Sigma +f p + + align:start position:0% + + + + align:start position:0% + +r Sigma + + align:start position:0% +r Sigma + + + align:start position:0% +r Sigma +a pi of R same expression minus + + align:start position:0% + + + + align:start position:0% + +Dadi pi + + align:start position:0% +Dadi pi + + + align:start position:0% +Dadi pi +r over + + align:start position:0% + + + + align:start position:0% + +pi and what happens is + + align:start position:0% +pi and what happens is + + + align:start position:0% +pi and what happens is +that these cancel + + align:start position:0% +that these cancel + + + align:start position:0% +that these cancel +out and what we have essentially is a k + + align:start position:0% +out and what we have essentially is a k + + + align:start position:0% +out and what we have essentially is a k +Infinity + + align:start position:0% +Infinity + + + align:start position:0% +Infinity +now + + align:start position:0% +now + + + align:start position:0% +now +and we then manipulate + + align:start position:0% +and we then manipulate + + + align:start position:0% +and we then manipulate +it to a point + + align:start position:0% +it to a point + + + align:start position:0% +it to a point +where 1 equals new Sigma + + align:start position:0% +where 1 equals new Sigma + + + align:start position:0% +where 1 equals new Sigma +F over Sigma + + align:start position:0% +F over Sigma + + + align:start position:0% +F over Sigma +a plus d b² squ + + align:start position:0% +a plus d b² squ + + + align:start position:0% +a plus d b² squ +because this expression here can be + + align:start position:0% +because this expression here can be + + + align:start position:0% +because this expression here can be +reduced to a + + align:start position:0% +reduced to a + + + align:start position:0% +reduced to a +b² and if you divide this expression by + + align:start position:0% +b² and if you divide this expression by + + + align:start position:0% +b² and if you divide this expression by +Sigma a in other words let's + + align:start position:0% + + + + align:start position:0% + +divide by by Sigma + + align:start position:0% + + + + align:start position:0% + +a we get the following + + align:start position:0% +a we get the following + + + align:start position:0% +a we get the following +expression K Infinity + + align:start position:0% +expression K Infinity + + + align:start position:0% +expression K Infinity +equals d + + align:start position:0% +equals d + + + align:start position:0% +equals d +b^ + + align:start position:0% +b^ + + + align:start position:0% +b^ +2 + 1 / Sigma + + align:start position:0% +2 + 1 / Sigma + + + align:start position:0% +2 + 1 / Sigma +a and here again this is the excess + + align:start position:0% +a and here again this is the excess + + + align:start position:0% +a and here again this is the excess +multiplication and K Infinity is defined + + align:start position:0% +multiplication and K Infinity is defined + + + align:start position:0% +multiplication and K Infinity is defined +as new Sigma + + align:start position:0% +as new Sigma + + + align:start position:0% +as new Sigma +F over Sigma + + align:start position:0% +F over Sigma + + + align:start position:0% +F over Sigma +a which you can recognize from before + + align:start position:0% +a which you can recognize from before + + + align:start position:0% +a which you can recognize from before +which does not have the Le + + align:start position:0% + + + + align:start position:0% + +ter so as we as we + + align:start position:0% +ter so as we as we + + + align:start position:0% +ter so as we as we +then look further in in this in this + + align:start position:0% +then look further in in this in this + + + align:start position:0% +then look further in in this in this +analysis we can we can identify certain + + align:start position:0% +analysis we can we can identify certain + + + align:start position:0% +analysis we can we can identify certain +critical parameters that we can use to + + align:start position:0% +critical parameters that we can use to + + + align:start position:0% +critical parameters that we can use to +identify whether the system is going to + + align:start position:0% +identify whether the system is going to + + + align:start position:0% +identify whether the system is going to +be critical or not and the most + + align:start position:0% +be critical or not and the most + + + align:start position:0% +be critical or not and the most +important part of this is going to be + + align:start position:0% +important part of this is going to be + + + align:start position:0% +important part of this is going to be +the geometric buckling has to be equal + + align:start position:0% +the geometric buckling has to be equal + + + align:start position:0% +the geometric buckling has to be equal +to the uh material buckling + + align:start position:0% + + + + align:start position:0% + +now there are lots of other + + align:start position:0% +now there are lots of other + + + align:start position:0% +now there are lots of other +approximations that we can go through + + align:start position:0% +approximations that we can go through + + + align:start position:0% +approximations that we can go through +but I just don't want to do that at this + + align:start position:0% +but I just don't want to do that at this + + + align:start position:0% +but I just don't want to do that at this +point in + + align:start position:0% +point in + + + align:start position:0% +point in +time but where we want to end up is you + + align:start position:0% +time but where we want to end up is you + + + align:start position:0% +time but where we want to end up is you +know if we want to go to a multi-group + + align:start position:0% +know if we want to go to a multi-group + + + align:start position:0% +know if we want to go to a multi-group +calculation the question as I mentioned + + align:start position:0% +calculation the question as I mentioned + + + align:start position:0% +calculation the question as I mentioned +earlier is how do we + + align:start position:0% +earlier is how do we + + + align:start position:0% +earlier is how do we +decide which of these groups and how do + + align:start position:0% +decide which of these groups and how do + + + align:start position:0% +decide which of these groups and how do +we want to break up these groups in + + align:start position:0% +we want to break up these groups in + + + align:start position:0% +we want to break up these groups in +terms of + + align:start position:0% +terms of + + + align:start position:0% +terms of +number of groups to be able to + + align:start position:0% +number of groups to be able to + + + align:start position:0% +number of groups to be able to +accurately model and this is pretty + + align:start position:0% +accurately model and this is pretty + + + align:start position:0% +accurately model and this is pretty +subjective and it's largely dependent + + align:start position:0% +subjective and it's largely dependent + + + align:start position:0% +subjective and it's largely dependent +upon the degree of change that's going + + align:start position:0% +upon the degree of change that's going + + + align:start position:0% +upon the degree of change that's going +on in any one of these groups to make + + align:start position:0% +on in any one of these groups to make + + + align:start position:0% +on in any one of these groups to make +some certain + + align:start position:0% +some certain + + + align:start position:0% +some certain +judgments when you think about some of + + align:start position:0% +judgments when you think about some of + + + align:start position:0% +judgments when you think about some of +these flux shapes and this chart + + align:start position:0% +these flux shapes and this chart + + + align:start position:0% +these flux shapes and this chart +basically shows what they might + + align:start position:0% +basically shows what they might + + + align:start position:0% +basically shows what they might +be you can see the normalized flux + + align:start position:0% +be you can see the normalized flux + + + align:start position:0% +be you can see the normalized flux +versus the normalized distance that the + + align:start position:0% +versus the normalized distance that the + + + align:start position:0% +versus the normalized distance that the +shapes are basically coign regard + + align:start position:0% +shapes are basically coign regard + + + align:start position:0% +shapes are basically coign regard +regardless of whether it's uh an + + align:start position:0% +regardless of whether it's uh an + + + align:start position:0% +regardless of whether it's uh an +infinite slab or an infinite cylinder + + align:start position:0% +infinite slab or an infinite cylinder + + + align:start position:0% +infinite slab or an infinite cylinder +the fundamental shape is the same and it + + align:start position:0% +the fundamental shape is the same and it + + + align:start position:0% +the fundamental shape is the same and it +does have some minor + + align:start position:0% +does have some minor + + + align:start position:0% +does have some minor +variations but each one will create a + + align:start position:0% +variations but each one will create a + + + align:start position:0% +variations but each one will create a +different criticality + + align:start position:0% + + + + align:start position:0% + +solution okay let's stop right + + align:start position:0% + + + + align:start position:0% + +there okay having having described that + + align:start position:0% +there okay having having described that + + + align:start position:0% +there okay having having described that +now let's let's take a quick look at + + align:start position:0% +now let's let's take a quick look at + + + align:start position:0% +now let's let's take a quick look at +what the difference between a one group + + align:start position:0% +what the difference between a one group + + + align:start position:0% +what the difference between a one group +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +go and a multigroup this would be a two + + align:start position:0% +go and a multigroup this would be a two + + + align:start position:0% +go and a multigroup this would be a two +group analysis where you have a fast and + + align:start position:0% +group analysis where you have a fast and + + + align:start position:0% +group analysis where you have a fast and +a thermal and a fast spectum in a one + + align:start position:0% +a thermal and a fast spectum in a one + + + align:start position:0% +a thermal and a fast spectum in a one +group analysis you'll see if you have a + + align:start position:0% +group analysis you'll see if you have a + + + align:start position:0% +group analysis you'll see if you have a +reflector you will see that the cor flux + + align:start position:0% +reflector you will see that the cor flux + + + align:start position:0% +reflector you will see that the cor flux +will gradually decrease and the + + align:start position:0% +will gradually decrease and the + + + align:start position:0% +will gradually decrease and the +reflector of course is used to uh + + align:start position:0% +reflector of course is used to uh + + + align:start position:0% +reflector of course is used to uh +prevent leakage and hopefully provide + + align:start position:0% +prevent leakage and hopefully provide + + + align:start position:0% +prevent leakage and hopefully provide +some additional neutrons to head back + + align:start position:0% +some additional neutrons to head back + + + align:start position:0% +some additional neutrons to head back +into the reactor core but it basically + + align:start position:0% +into the reactor core but it basically + + + align:start position:0% +into the reactor core but it basically +uh allows one to have essentially + + align:start position:0% +uh allows one to have essentially + + + align:start position:0% +uh allows one to have essentially +uniform power distribution in the core + + align:start position:0% +uniform power distribution in the core + + + align:start position:0% +uniform power distribution in the core +and conserves and reduces the amount of + + align:start position:0% +and conserves and reduces the amount of + + + align:start position:0% +and conserves and reduces the amount of +leakage if you look at the fast and + + align:start position:0% +leakage if you look at the fast and + + + align:start position:0% +leakage if you look at the fast and +thermal Spectrum you can see that the + + align:start position:0% +thermal Spectrum you can see that the + + + align:start position:0% +thermal Spectrum you can see that the +fast Spectrum behaves quite differently + + align:start position:0% +fast Spectrum behaves quite differently + + + align:start position:0% +fast Spectrum behaves quite differently +than the thermal Spectrum in the fast + + align:start position:0% +than the thermal Spectrum in the fast + + + align:start position:0% +than the thermal Spectrum in the fast +Spectrum the neutrons mean free path is + + align:start position:0% +Spectrum the neutrons mean free path is + + + align:start position:0% +Spectrum the neutrons mean free path is +much larger and the and the the flux + + align:start position:0% +much larger and the and the the flux + + + align:start position:0% +much larger and the and the the flux +distribution of fast neutrons is very + + align:start position:0% +distribution of fast neutrons is very + + + align:start position:0% +distribution of fast neutrons is very +similar to that of the the thermal + + align:start position:0% +similar to that of the the thermal + + + align:start position:0% +similar to that of the the thermal +neutrons in a single group but much + + align:start position:0% +neutrons in a single group but much + + + align:start position:0% +neutrons in a single group but much +higher in terms of + + align:start position:0% +higher in terms of + + + align:start position:0% +higher in terms of +numbers because not all of the fast + + align:start position:0% +numbers because not all of the fast + + + align:start position:0% +numbers because not all of the fast +neutrons will end up being thermalized + + align:start position:0% +neutrons will end up being thermalized + + + align:start position:0% +neutrons will end up being thermalized +because of capture so what we see + + align:start position:0% +because of capture so what we see + + + align:start position:0% +because of capture so what we see +happening in terms of the fision area is + + align:start position:0% +happening in terms of the fision area is + + + align:start position:0% +happening in terms of the fision area is +that the number of neutrons is much + + align:start position:0% +that the number of neutrons is much + + + align:start position:0% +that the number of neutrons is much +lower and that you'll see that in the + + align:start position:0% +lower and that you'll see that in the + + + align:start position:0% +lower and that you'll see that in the +reflector there's a peak in the uh + + align:start position:0% +reflector there's a peak in the uh + + + align:start position:0% +reflector there's a peak in the uh +Neutron thermal spectrum because the + + align:start position:0% +Neutron thermal spectrum because the + + + align:start position:0% +Neutron thermal spectrum because the +fast neutrons are slowing down in this + + align:start position:0% +fast neutrons are slowing down in this + + + align:start position:0% +fast neutrons are slowing down in this +area + + align:start position:0% +area + + + align:start position:0% +area +so it becomes very important to when + + align:start position:0% +so it becomes very important to when + + + align:start position:0% +so it becomes very important to when +designing or or modeling a a a reactor + + align:start position:0% +designing or or modeling a a a reactor + + + align:start position:0% +designing or or modeling a a a reactor +is understanding the nature of what's + + align:start position:0% +is understanding the nature of what's + + + align:start position:0% +is understanding the nature of what's +outside the core and whether or not + + align:start position:0% +outside the core and whether or not + + + align:start position:0% +outside the core and whether or not +fluxes will peak in that Z you can see + + align:start position:0% +fluxes will peak in that Z you can see + + + align:start position:0% +fluxes will peak in that Z you can see +the flux could be as high as that in the + + align:start position:0% +the flux could be as high as that in the + + + align:start position:0% +the flux could be as high as that in the +center of the core in this model and + + align:start position:0% +center of the core in this model and + + + align:start position:0% +center of the core in this model and +also it does there is a big difference + + align:start position:0% +also it does there is a big difference + + + align:start position:0% +also it does there is a big difference +between the Fast and the thermal + + align:start position:0% +between the Fast and the thermal + + + align:start position:0% +between the Fast and the thermal +spectrum and you have to be very + + align:start position:0% +spectrum and you have to be very + + + align:start position:0% +spectrum and you have to be very +cognizant of + + align:start position:0% +cognizant of + + + align:start position:0% +cognizant of +that now what we're going to talk about + + align:start position:0% +that now what we're going to talk about + + + align:start position:0% +that now what we're going to talk about +here just very briefly is is some things + + align:start position:0% +here just very briefly is is some things + + + align:start position:0% +here just very briefly is is some things +that this is sort of a review where you + + align:start position:0% +that this is sort of a review where you + + + align:start position:0% +that this is sort of a review where you +can do + + align:start position:0% +can do + + + align:start position:0% +can do +analysis Beyond diffusion theory that we + + align:start position:0% +analysis Beyond diffusion theory that we + + + align:start position:0% +analysis Beyond diffusion theory that we +call Monte Carlo analysis and basically + + align:start position:0% +call Monte Carlo analysis and basically + + + align:start position:0% +call Monte Carlo analysis and basically +what it does is it tracks a neutron of + + align:start position:0% +what it does is it tracks a neutron of + + + align:start position:0% +what it does is it tracks a neutron of +pick your energy pick your velocity pick + + align:start position:0% +pick your energy pick your velocity pick + + + align:start position:0% +pick your energy pick your velocity pick +your direction pick your location and it + + align:start position:0% +your direction pick your location and it + + + align:start position:0% +your direction pick your location and it +will track that neutron as a function of + + align:start position:0% +will track that neutron as a function of + + + align:start position:0% +will track that neutron as a function of +its path length and will in the mix of + + align:start position:0% +its path length and will in the mix of + + + align:start position:0% +its path length and will in the mix of +the reactor design it will determine + + align:start position:0% +the reactor design it will determine + + + align:start position:0% +the reactor design it will determine +whether that Neutron will leak out + + align:start position:0% +whether that Neutron will leak out + + + align:start position:0% +whether that Neutron will leak out +whether it will collide whether it will + + align:start position:0% +whether it will collide whether it will + + + align:start position:0% +whether it will collide whether it will +capture and in what energy will go and + + align:start position:0% +capture and in what energy will go and + + + align:start position:0% +capture and in what energy will go and +what energy will scatter and what + + align:start position:0% +what energy will scatter and what + + + align:start position:0% +what energy will scatter and what +direction it will go and ultimately that + + align:start position:0% +direction it will go and ultimately that + + + align:start position:0% +direction it will go and ultimately that +will be able to be leaked again or + + align:start position:0% +will be able to be leaked again or + + + align:start position:0% +will be able to be leaked again or +collided again and if it's captured it's + + align:start position:0% +collided again and if it's captured it's + + + align:start position:0% +collided again and if it's captured it's +basically out of the system if it leaks + + align:start position:0% +basically out of the system if it leaks + + + align:start position:0% +basically out of the system if it leaks +it's also out of the system or it can + + align:start position:0% +it's also out of the system or it can + + + align:start position:0% +it's also out of the system or it can +have Collision that can create a fision + + align:start position:0% +have Collision that can create a fision + + + align:start position:0% +have Collision that can create a fision +neutron which then is tracked as well as + + align:start position:0% +neutron which then is tracked as well as + + + align:start position:0% +neutron which then is tracked as well as +the start of a fision which may be in a + + align:start position:0% +the start of a fision which may be in a + + + align:start position:0% +the start of a fision which may be in a +quite different place so this Monte + + align:start position:0% +quite different place so this Monte + + + align:start position:0% +quite different place so this Monte +Carlo technique is essentially another + + align:start position:0% +Carlo technique is essentially another + + + align:start position:0% +Carlo technique is essentially another +way of + + align:start position:0% +way of + + + align:start position:0% +way of +doing not a diffusion Theory calculation + + align:start position:0% +doing not a diffusion Theory calculation + + + align:start position:0% +doing not a diffusion Theory calculation +but more of a transport Theory + + align:start position:0% +but more of a transport Theory + + + align:start position:0% +but more of a transport Theory +calculation where if you start your + + align:start position:0% +calculation where if you start your + + + align:start position:0% +calculation where if you start your +number of neutrons and you end up after + + align:start position:0% +number of neutrons and you end up after + + + align:start position:0% +number of neutrons and you end up after +a certain number of trapping a certain + + align:start position:0% +a certain number of trapping a certain + + + align:start position:0% +a certain number of trapping a certain +number of neutrons that number is equal + + align:start position:0% +number of neutrons that number is equal + + + align:start position:0% +number of neutrons that number is equal +to the same number you started with you + + align:start position:0% +to the same number you started with you + + + align:start position:0% +to the same number you started with you +have quote unquote a critical system so + + align:start position:0% +have quote unquote a critical system so + + + align:start position:0% +have quote unquote a critical system so +this is another mechanism whereby people + + align:start position:0% +this is another mechanism whereby people + + + align:start position:0% +this is another mechanism whereby people +can do more detailed analysis than + + align:start position:0% +can do more detailed analysis than + + + align:start position:0% +can do more detailed analysis than +diffusion the let me now TR try and + + align:start position:0% +diffusion the let me now TR try and + + + align:start position:0% +diffusion the let me now TR try and +introduce the boltzman equation because + + align:start position:0% +introduce the boltzman equation because + + + align:start position:0% +introduce the boltzman equation because +it it basically gives us a much deeper + + align:start position:0% +it it basically gives us a much deeper + + + align:start position:0% +it it basically gives us a much deeper +appreciation than than the fusion Theory + + align:start position:0% +appreciation than than the fusion Theory + + + align:start position:0% +appreciation than than the fusion Theory +can in terms of what's going on and it + + align:start position:0% +can in terms of what's going on and it + + + align:start position:0% +can in terms of what's going on and it +will also provide you with an + + align:start position:0% +will also provide you with an + + + align:start position:0% +will also provide you with an +understanding of how one might break + + align:start position:0% +understanding of how one might break + + + align:start position:0% +understanding of how one might break +down the multi-group problem into uh + + align:start position:0% +down the multi-group problem into uh + + + align:start position:0% +down the multi-group problem into uh +something that's understandable from a + + align:start position:0% +something that's understandable from a + + + align:start position:0% +something that's understandable from a +mathematical + + align:start position:0% +mathematical + + + align:start position:0% +mathematical +standpoint so in in Neutron + + align:start position:0% + + + + align:start position:0% + +transport we have to know certain things + + align:start position:0% +transport we have to know certain things + + + align:start position:0% +transport we have to know certain things +we need to know the position of the + + align:start position:0% +we need to know the position of the + + + align:start position:0% +we need to know the position of the +neutron sort of like in the in the uh in + + align:start position:0% +neutron sort of like in the in the uh in + + + align:start position:0% +neutron sort of like in the in the uh in +in the um + + align:start position:0% +in the um + + + align:start position:0% +in the um +the mcnp or or Monte Carlo method we + + align:start position:0% +the mcnp or or Monte Carlo method we + + + align:start position:0% +the mcnp or or Monte Carlo method we +need to know its velocity of the neutron + + align:start position:0% +need to know its velocity of the neutron + + + align:start position:0% +need to know its velocity of the neutron +which we can talk + + align:start position:0% +which we can talk + + + align:start position:0% +which we can talk +about energy and we need to know the + + align:start position:0% +about energy and we need to know the + + + align:start position:0% +about energy and we need to know the +time in other words when did this take + + align:start position:0% + + + + align:start position:0% + +place and the velocity obviously has a + + align:start position:0% +place and the velocity obviously has a + + + align:start position:0% +place and the velocity obviously has a +certain + + align:start position:0% +certain + + + align:start position:0% +certain +direction and we can correlate that to a + + align:start position:0% +direction and we can correlate that to a + + + align:start position:0% +direction and we can correlate that to a +certain energy + + align:start position:0% +certain energy + + + align:start position:0% +certain energy +and as things occur we will + + align:start position:0% +and as things occur we will + + + align:start position:0% +and as things occur we will +have location energy location + + align:start position:0% +have location energy location + + + align:start position:0% +have location energy location +Direction and energy as + + align:start position:0% +Direction and energy as + + + align:start position:0% +Direction and energy as +criteria and the flux in the Bulman + + align:start position:0% +criteria and the flux in the Bulman + + + align:start position:0% +criteria and the flux in the Bulman +equation is represented and I will not + + align:start position:0% +equation is represented and I will not + + + align:start position:0% +equation is represented and I will not +repeat it every time it's + + align:start position:0% +repeat it every time it's + + + align:start position:0% +repeat it every time it's +location + + align:start position:0% +location + + + align:start position:0% +location +energy Direction and time so without + + align:start position:0% +energy Direction and time so without + + + align:start position:0% +energy Direction and time so without +having to repeat all those parameters + + align:start position:0% +having to repeat all those parameters + + + align:start position:0% +having to repeat all those parameters +just assume when I write down flux it is + + align:start position:0% +just assume when I write down flux it is + + + align:start position:0% +just assume when I write down flux it is +it is it represents these + + align:start position:0% +it is it represents these + + + align:start position:0% +it is it represents these +variables now in the boltzman equation + + align:start position:0% +variables now in the boltzman equation + + + align:start position:0% +variables now in the boltzman equation +we want attract + + align:start position:0% +we want attract + + + align:start position:0% +we want attract +neutrons so we need to take the + + align:start position:0% +neutrons so we need to take the + + + align:start position:0% +neutrons so we need to take the +flux and divide it by the + + align:start position:0% +flux and divide it by the + + + align:start position:0% +flux and divide it by the +velocity I'm going to write it + + align:start position:0% +velocity I'm going to write it + + + align:start position:0% +velocity I'm going to write it +once so if we want to know the change + + align:start position:0% +once so if we want to know the change + + + align:start position:0% +once so if we want to know the change +the rate of change of + + align:start position:0% + + + + align:start position:0% + +neutrons as a function of + + align:start position:0% +neutrons as a function of + + + align:start position:0% +neutrons as a function of +time we will write this expression + + align:start position:0% +time we will write this expression + + + align:start position:0% +time we will write this expression +if the rate of change of neutrons is + + align:start position:0% +if the rate of change of neutrons is + + + align:start position:0% +if the rate of change of neutrons is +zero so be it but the rate of neutron + + align:start position:0% +zero so be it but the rate of neutron + + + align:start position:0% +zero so be it but the rate of neutron +change is a function of the same things + + align:start position:0% +change is a function of the same things + + + align:start position:0% +change is a function of the same things +we talked about before + + align:start position:0% +we talked about before + + + align:start position:0% +we talked about before +leakage the neutron is going in a + + align:start position:0% +leakage the neutron is going in a + + + align:start position:0% +leakage the neutron is going in a +certain direction + + align:start position:0% +certain direction + + + align:start position:0% +certain direction +Omega there's a certain leakage term + + align:start position:0% +Omega there's a certain leakage term + + + align:start position:0% +Omega there's a certain leakage term +that we're not going to repeat here + + align:start position:0% +that we're not going to repeat here + + + align:start position:0% +that we're not going to repeat here +which we'll call + + align:start position:0% + + + + align:start position:0% + +leakage there's also + + align:start position:0% +leakage there's also + + + align:start position:0% +leakage there's also +a mechanism + + align:start position:0% +a mechanism + + + align:start position:0% +a mechanism +whereby there's + + align:start position:0% +whereby there's + + + align:start position:0% +whereby there's +a macroscopic + + align:start position:0% +a macroscopic + + + align:start position:0% +a macroscopic +cross-section for removal of neutrons + + align:start position:0% +cross-section for removal of neutrons + + + align:start position:0% +cross-section for removal of neutrons +this is the total absorption and + + align:start position:0% +this is the total absorption and + + + align:start position:0% +this is the total absorption and +scattering cross-section why why are we + + align:start position:0% +scattering cross-section why why are we + + + align:start position:0% +scattering cross-section why why are we +worried about total absorption of + + align:start position:0% +worried about total absorption of + + + align:start position:0% +worried about total absorption of +scattering because once a neutron is + + align:start position:0% +scattering because once a neutron is + + + align:start position:0% +scattering because once a neutron is +scattered it loses the E that we're + + align:start position:0% +scattered it loses the E that we're + + + align:start position:0% +scattered it loses the E that we're +trying to track obviously once it's + + align:start position:0% +trying to track obviously once it's + + + align:start position:0% +trying to track obviously once it's +absorbed it's done + + align:start position:0% +absorbed it's done + + + align:start position:0% +absorbed it's done +I'm afraid I'm going to have to repeat + + align:start position:0% +I'm afraid I'm going to have to repeat + + + align:start position:0% +I'm afraid I'm going to have to repeat +all these omegas and + + align:start position:0% +all these omegas and + + + align:start position:0% +all these omegas and +T's but I won't do it for the + + align:start position:0% + + + + align:start position:0% + +fox one thing it doesn't have is a t + + align:start position:0% +fox one thing it doesn't have is a t + + + align:start position:0% +fox one thing it doesn't have is a t +here which is + + align:start position:0% + + + + align:start position:0% + +good so what this is what this term + + align:start position:0% +good so what this is what this term + + + align:start position:0% +good so what this is what this term +basically + + align:start position:0% +basically + + + align:start position:0% +basically +represents is the interaction or + + align:start position:0% + + + + align:start position:0% + +removal + + align:start position:0% +removal + + + align:start position:0% +removal +of neutrons + + align:start position:0% +of neutrons + + + align:start position:0% +of neutrons +due to + + align:start position:0% +due to + + + align:start position:0% +due to +absorption or + + align:start position:0% + + + + align:start position:0% + +scatter that would be going at location + + align:start position:0% +scatter that would be going at location + + + align:start position:0% +scatter that would be going at location +R going in Direction + + align:start position:0% + + + + align:start position:0% + +Omega we also produce + + align:start position:0% +Omega we also produce + + + align:start position:0% +Omega we also produce +neutrons leakage and removal we're also + + align:start position:0% +neutrons leakage and removal we're also + + + align:start position:0% +neutrons leakage and removal we're also +producing neutrons we have a yield rate + + align:start position:0% +producing neutrons we have a yield rate + + + align:start position:0% +producing neutrons we have a yield rate +of neutrons if a neutron vision occurs + + align:start position:0% +of neutrons if a neutron vision occurs + + + align:start position:0% +of neutrons if a neutron vision occurs +at ngg e this is a spectrum of neutrons + + align:start position:0% +at ngg e this is a spectrum of neutrons + + + align:start position:0% +at ngg e this is a spectrum of neutrons +uh energies that are produced so we're + + align:start position:0% +uh energies that are produced so we're + + + align:start position:0% +uh energies that are produced so we're +looking only for the neutrons at energy + + align:start position:0% +looking only for the neutrons at energy + + + align:start position:0% +looking only for the neutrons at energy +E from the Spectrum and we integrate + + align:start position:0% +E from the Spectrum and we integrate + + + align:start position:0% +E from the Spectrum and we integrate +over D + + align:start position:0% + + + + align:start position:0% + +Prime and Omega Prime + + align:start position:0% +Prime and Omega Prime + + + align:start position:0% +Prime and Omega Prime +now because we're only interested in + + align:start position:0% +now because we're only interested in + + + align:start position:0% +now because we're only interested in +those neutrons that end up with this + + align:start position:0% +those neutrons that end up with this + + + align:start position:0% +those neutrons that end up with this +energy going in our + + align:start position:0% + + + + align:start position:0% + +Direction so we put + + align:start position:0% +Direction so we put + + + align:start position:0% +Direction so we put +the same production term + + align:start position:0% +the same production term + + + align:start position:0% +the same production term +here this is a + + align:start position:0% +here this is a + + + align:start position:0% +here this is a +vision r e Prime now Omega + + align:start position:0% +vision r e Prime now Omega + + + align:start position:0% +vision r e Prime now Omega +Prime Times the + + align:start position:0% +Prime Times the + + + align:start position:0% +Prime Times the +flux with all the + + align:start position:0% +flux with all the + + + align:start position:0% +flux with all the +Primes and it also has a function of T + + align:start position:0% +Primes and it also has a function of T + + + align:start position:0% +Primes and it also has a function of T +here so what this term is the + + align:start position:0% +here so what this term is the + + + align:start position:0% +here so what this term is the +production and and we don't care where + + align:start position:0% +production and and we don't care where + + + align:start position:0% +production and and we don't care where +it comes from as long as it ends up at + + align:start position:0% +it comes from as long as it ends up at + + + align:start position:0% +it comes from as long as it ends up at +point R + + align:start position:0% + + + + align:start position:0% + +of neutrons from energy e Prime whatever + + align:start position:0% +of neutrons from energy e Prime whatever + + + align:start position:0% +of neutrons from energy e Prime whatever +that is and that's the whole Suite + + align:start position:0% +that is and that's the whole Suite + + + align:start position:0% +that is and that's the whole Suite +because we're integrating overal energy + + align:start position:0% +because we're integrating overal energy + + + align:start position:0% +because we're integrating overal energy +that end up with this + + align:start position:0% + + + + align:start position:0% + +energy 2 + + align:start position:0% + + + + align:start position:0% + +e then we also have + + align:start position:0% +e then we also have + + + align:start position:0% +e then we also have +another interesting term that if we + + align:start position:0% +another interesting term that if we + + + align:start position:0% +another interesting term that if we +integrate over all e + + align:start position:0% + + + + align:start position:0% + +Prime and all Omega + + align:start position:0% + + + + align:start position:0% + +Prime that there's a + + align:start position:0% +Prime that there's a + + + align:start position:0% +Prime that there's a +scattering + + align:start position:0% +scattering + + + align:start position:0% +scattering +term where a neutron at at location R is + + align:start position:0% +term where a neutron at at location R is + + + align:start position:0% +term where a neutron at at location R is +scattered from energy e Prime to + + align:start position:0% +scattered from energy e Prime to + + + align:start position:0% +scattered from energy e Prime to +e and from Omega Prime to + + align:start position:0% + + + + align:start position:0% + +Omega with the flux of r e Prime Omega + + align:start position:0% +Omega with the flux of r e Prime Omega + + + align:start position:0% +Omega with the flux of r e Prime Omega +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +T So What what this term represents is + + align:start position:0% +T So What what this term represents is + + + align:start position:0% +T So What what this term represents is +the + + align:start position:0% + + + + align:start position:0% + +scattering + + align:start position:0% +scattering + + + align:start position:0% +scattering +into E from all + + align:start position:0% +into E from all + + + align:start position:0% +into E from all +energies and all directions Omega + + align:start position:0% +energies and all directions Omega + + + align:start position:0% +energies and all directions Omega +Prime so if you look at the boltzman + + align:start position:0% +Prime so if you look at the boltzman + + + align:start position:0% +Prime so if you look at the boltzman +equation which is what has been just + + align:start position:0% + + + + align:start position:0% + +written is that it shows you that if the + + align:start position:0% +written is that it shows you that if the + + + align:start position:0% +written is that it shows you that if the +neutron population at at point R with e + + align:start position:0% +neutron population at at point R with e + + + align:start position:0% +neutron population at at point R with e +Prime going going in Omega at time T + + align:start position:0% +Prime going going in Omega at time T + + + align:start position:0% +Prime going going in Omega at time T +this is neutrons you have a leakage term + + align:start position:0% +this is neutrons you have a leakage term + + + align:start position:0% +this is neutrons you have a leakage term +straight away you have a removal based + + align:start position:0% +straight away you have a removal based + + + align:start position:0% +straight away you have a removal based +on + + align:start position:0% +on + + + align:start position:0% +on +total uh removal including capture and + + align:start position:0% +total uh removal including capture and + + + align:start position:0% +total uh removal including capture and +and scattering of neutrons from this + + align:start position:0% +and scattering of neutrons from this + + + align:start position:0% +and scattering of neutrons from this +energy and direction we produce it from + + align:start position:0% +energy and direction we produce it from + + + align:start position:0% +energy and direction we produce it from +all energies that end up within this + + align:start position:0% +all energies that end up within this + + + align:start position:0% +all energies that end up within this +energy Bank band we don't care where or + + align:start position:0% +energy Bank band we don't care where or + + + align:start position:0% +energy Bank band we don't care where or +how but we definitely know it's at + + align:start position:0% +how but we definitely know it's at + + + align:start position:0% +how but we definitely know it's at +location R and we also have it as a uh + + align:start position:0% +location R and we also have it as a uh + + + align:start position:0% +location R and we also have it as a uh +essentially a scattering into our energy + + align:start position:0% +essentially a scattering into our energy + + + align:start position:0% +essentially a scattering into our energy +band at location R and going in + + align:start position:0% +band at location R and going in + + + align:start position:0% +band at location R and going in +Direction + + align:start position:0% + + + + align:start position:0% + +Omega so this is the fundamental + + align:start position:0% +Omega so this is the fundamental + + + align:start position:0% +Omega so this is the fundamental +equation that we can write uh that + + align:start position:0% +equation that we can write uh that + + + align:start position:0% +equation that we can write uh that +describes how neutrons in fact do uh + + align:start position:0% +describes how neutrons in fact do uh + + + align:start position:0% +describes how neutrons in fact do uh +now if we wanted to do this we could + + align:start position:0% +now if we wanted to do this we could + + + align:start position:0% +now if we wanted to do this we could +write this in in a number of + + align:start position:0% +write this in in a number of + + + align:start position:0% +write this in in a number of +groups rather than generic and we can + + align:start position:0% +groups rather than generic and we can + + + align:start position:0% +groups rather than generic and we can +collapse groups by using what we call + + align:start position:0% +collapse groups by using what we call + + + align:start position:0% +collapse groups by using what we call +either an energy weighting system or + + align:start position:0% +either an energy weighting system or + + + align:start position:0% +either an energy weighting system or +um but typically it's done by energy + + align:start position:0% +um but typically it's done by energy + + + align:start position:0% +um but typically it's done by energy +waiting because for example if you want + + align:start position:0% +waiting because for example if you want + + + align:start position:0% +waiting because for example if you want +to + + align:start position:0% +to + + + align:start position:0% +to +collapse and create a + + align:start position:0% + + + + align:start position:0% + +group what you would do if say if you + + align:start position:0% +group what you would do if say if you + + + align:start position:0% +group what you would do if say if you +wanted to CR section you would be able + + align:start position:0% +wanted to CR section you would be able + + + align:start position:0% +wanted to CR section you would be able +to take the macroscopic + + align:start position:0% +to take the macroscopic + + + align:start position:0% +to take the macroscopic +cross-section at a certain location over + + align:start position:0% +cross-section at a certain location over + + + align:start position:0% +cross-section at a certain location over +a certain energy range and that would be + + align:start position:0% +a certain energy range and that would be + + + align:start position:0% +a certain energy range and that would be +the average cross-section to do the + + align:start position:0% +the average cross-section to do the + + + align:start position:0% +the average cross-section to do the +integral over that energy level of the + + align:start position:0% +integral over that energy level of the + + + align:start position:0% +integral over that energy level of the +particular + + align:start position:0% +particular + + + align:start position:0% +particular +cross-section let's just call it uh + + align:start position:0% +cross-section let's just call it uh + + + align:start position:0% +cross-section let's just call it uh +absorption times the flux over that + + align:start position:0% +absorption times the flux over that + + + align:start position:0% +absorption times the flux over that +region divid div + + align:start position:0% +region divid div + + + align:start position:0% +region divid div +by the integral over the all the all the + + align:start position:0% +by the integral over the all the all the + + + align:start position:0% +by the integral over the all the all the +energy over that over that same + + align:start position:0% + + + + align:start position:0% + +range so this takes the the + + align:start position:0% +range so this takes the the + + + align:start position:0% +range so this takes the the +cross-section as a function of weighted + + align:start position:0% +cross-section as a function of weighted + + + align:start position:0% +cross-section as a function of weighted +averages over the flux to give you the + + align:start position:0% +averages over the flux to give you the + + + align:start position:0% +averages over the flux to give you the +cross-sections you would use for + + align:start position:0% +cross-sections you would use for + + + align:start position:0% +cross-sections you would use for +multigroup set and that's basically how + + align:start position:0% +multigroup set and that's basically how + + + align:start position:0% +multigroup set and that's basically how +you would do the + + align:start position:0% +you would do the + + + align:start position:0% +you would do the +multi-group analysis but the boltzman + + align:start position:0% +multi-group analysis but the boltzman + + + align:start position:0% +multi-group analysis but the boltzman +equation is a very powerful equation not + + align:start position:0% +equation is a very powerful equation not + + + align:start position:0% +equation is a very powerful equation not +because you're going to be running + + align:start position:0% +because you're going to be running + + + align:start position:0% +because you're going to be running +analysis using it but because it gives + + align:start position:0% +analysis using it but because it gives + + + align:start position:0% +analysis using it but because it gives +you a way to think about what's going on + + align:start position:0% +you a way to think about what's going on + + + align:start position:0% +you a way to think about what's going on +in the reactor as a function from the + + align:start position:0% +in the reactor as a function from the + + + align:start position:0% +in the reactor as a function from the +perspective of the neutron and the + + align:start position:0% +perspective of the neutron and the + + + align:start position:0% +perspective of the neutron and the +things that can occur to it and how it + + align:start position:0% +things that can occur to it and how it + + + align:start position:0% +things that can occur to it and how it +might end up in a particular Energy + + align:start position:0% +might end up in a particular Energy + + + align:start position:0% +might end up in a particular Energy +Group which you then can do a + + align:start position:0% +Group which you then can do a + + + align:start position:0% +Group which you then can do a +multi-group either diffusion equation or + + align:start position:0% +multi-group either diffusion equation or + + + align:start position:0% +multi-group either diffusion equation or +solving these types of equations more + + align:start position:0% +solving these types of equations more + + + align:start position:0% +solving these types of equations more +more + + align:start position:0% +more + + + align:start position:0% +more +rigorously now + + align:start position:0% +rigorously now + + + align:start position:0% +rigorously now +what what I like to sort of wrap up with + + align:start position:0% +what what I like to sort of wrap up with + + + align:start position:0% +what what I like to sort of wrap up with +is what does all this + + align:start position:0% +is what does all this + + + align:start position:0% +is what does all this +mean to a nuclear engineer it's + + align:start position:0% +mean to a nuclear engineer it's + + + align:start position:0% +mean to a nuclear engineer it's +obviously very important to be able to + + align:start position:0% +obviously very important to be able to + + + align:start position:0% +obviously very important to be able to +understand the basic reactor + + align:start position:0% +understand the basic reactor + + + align:start position:0% +understand the basic reactor +physics but what's really important for + + align:start position:0% +physics but what's really important for + + + align:start position:0% +physics but what's really important for +for the for the engineer that says well + + align:start position:0% +for the for the engineer that says well + + + align:start position:0% +for the for the engineer that says well +how am I going to make use of this in + + align:start position:0% +how am I going to make use of this in + + + align:start position:0% +how am I going to make use of this in +terms of making power and it sort of + + align:start position:0% +terms of making power and it sort of + + + align:start position:0% +terms of making power and it sort of +gets us back to the to the + + align:start position:0% +gets us back to the to the + + + align:start position:0% +gets us back to the to the +first few slides that we started talking + + align:start position:0% +first few slides that we started talking + + + align:start position:0% +first few slides that we started talking +about and and the concept is is reaction + + align:start position:0% + + + + align:start position:0% + +rate now the reaction rate basically + + align:start position:0% +rate now the reaction rate basically + + + align:start position:0% +rate now the reaction rate basically +is how we going to make + + align:start position:0% +is how we going to make + + + align:start position:0% +is how we going to make +heat and of + + align:start position:0% +heat and of + + + align:start position:0% +heat and of +course generally reaction rates are + + align:start position:0% +course generally reaction rates are + + + align:start position:0% +course generally reaction rates are +macroscopic cross-sections times the + + align:start position:0% +macroscopic cross-sections times the + + + align:start position:0% +macroscopic cross-sections times the +flux over the + + align:start position:0% + + + + align:start position:0% + +volume okay so if you take a certain + + align:start position:0% +volume okay so if you take a certain + + + align:start position:0% +volume okay so if you take a certain +volume you have a c amount of + + align:start position:0% +volume you have a c amount of + + + align:start position:0% +volume you have a c amount of +material let's just take the fision + + align:start position:0% +material let's just take the fision + + + align:start position:0% +material let's just take the fision +fision cross-section as the issue you + + align:start position:0% +fision cross-section as the issue you + + + align:start position:0% +fision cross-section as the issue you +you you take the flux multiply by the + + align:start position:0% +you you take the flux multiply by the + + + align:start position:0% +you you take the flux multiply by the +cross-section average it integrate it + + align:start position:0% +cross-section average it integrate it + + + align:start position:0% +cross-section average it integrate it +over the whole volume let's assume this + + align:start position:0% +over the whole volume let's assume this + + + align:start position:0% +over the whole volume let's assume this +has a certain Sigma F and a certain flux + + align:start position:0% +has a certain Sigma F and a certain flux + + + align:start position:0% +has a certain Sigma F and a certain flux +distribution you will get a certain + + align:start position:0% +distribution you will get a certain + + + align:start position:0% +distribution you will get a certain +amount of neutrons reacting in this + + align:start position:0% +amount of neutrons reacting in this + + + align:start position:0% +amount of neutrons reacting in this +space whether it's solved by the + + align:start position:0% +space whether it's solved by the + + + align:start position:0% +space whether it's solved by the +boltzman equation or the diffusion + + align:start position:0% +boltzman equation or the diffusion + + + align:start position:0% +boltzman equation or the diffusion +equation or or some Monte caros + + align:start position:0% +equation or or some Monte caros + + + align:start position:0% +equation or or some Monte caros +simulation now for us what we want to + + align:start position:0% +simulation now for us what we want to + + + align:start position:0% +simulation now for us what we want to +know is what + + align:start position:0% +know is what + + + align:start position:0% +know is what +power in this case thermal + + align:start position:0% + + + + align:start position:0% + +power are we going to be able to create + + align:start position:0% +power are we going to be able to create + + + align:start position:0% +power are we going to be able to create +from this configuration of fuel and + + align:start position:0% +from this configuration of fuel and + + + align:start position:0% +from this configuration of fuel and +materials and essentially it's it's it's + + align:start position:0% +materials and essentially it's it's it's + + + align:start position:0% +materials and essentially it's it's it's +the reaction rate times the energy per + + align:start position:0% +the reaction rate times the energy per + + + align:start position:0% +the reaction rate times the energy per +reaction so we have a term that we use + + align:start position:0% +reaction so we have a term that we use + + + align:start position:0% +reaction so we have a term that we use +called the energy per fision and you + + align:start position:0% +called the energy per fision and you + + + align:start position:0% +called the energy per fision and you +recall that was about 200 + + align:start position:0% + + + + align:start position:0% + +me integrated + + align:start position:0% +me integrated + + + align:start position:0% +me integrated +over and the only way you can make a + + align:start position:0% +over and the only way you can make a + + + align:start position:0% +over and the only way you can make a +fision is have material that's this eff + + align:start position:0% +fision is have material that's this eff + + + align:start position:0% +fision is have material that's this eff +visionable times the + + align:start position:0% +visionable times the + + + align:start position:0% +visionable times the +flux over the volume so you're + + align:start position:0% +flux over the volume so you're + + + align:start position:0% +flux over the volume so you're +integrating it over the volume and of + + align:start position:0% +integrating it over the volume and of + + + align:start position:0% +integrating it over the volume and of +course this term + + align:start position:0% +course this term + + + align:start position:0% +course this term +Sigma + + align:start position:0% +Sigma + + + align:start position:0% +Sigma +f is a function of the number density of + + align:start position:0% +f is a function of the number density of + + + align:start position:0% +f is a function of the number density of +uranium + + align:start position:0% +uranium + + + align:start position:0% +uranium +235 or visionable materials times the + + align:start position:0% +235 or visionable materials times the + + + align:start position:0% +235 or visionable materials times the +uranium 235 + + align:start position:0% +uranium 235 + + + align:start position:0% +uranium 235 +cross-section and if you want to make it + + align:start position:0% +cross-section and if you want to make it + + + align:start position:0% +cross-section and if you want to make it +a function of a you can do + + align:start position:0% + + + + align:start position:0% + +it this is what what what the purpose of + + align:start position:0% +it this is what what what the purpose of + + + align:start position:0% +it this is what what what the purpose of +this entire lecture was is to understand + + align:start position:0% +this entire lecture was is to understand + + + align:start position:0% +this entire lecture was is to understand +that you have core power distribution + + align:start position:0% +that you have core power distribution + + + align:start position:0% +that you have core power distribution +that you can calculate using the fusion + + align:start position:0% +that you can calculate using the fusion + + + align:start position:0% +that you can calculate using the fusion +Theory but that core power distribution + + align:start position:0% +Theory but that core power distribution + + + align:start position:0% +Theory but that core power distribution +creates a flux that flux then depending + + align:start position:0% +creates a flux that flux then depending + + + align:start position:0% +creates a flux that flux then depending +upon how you configure your + + align:start position:0% +upon how you configure your + + + align:start position:0% +upon how you configure your +fuel will be able to produce a certain + + align:start position:0% +fuel will be able to produce a certain + + + align:start position:0% +fuel will be able to produce a certain +amount of energy at 200 Ms for vision + + align:start position:0% +amount of energy at 200 Ms for vision + + + align:start position:0% +amount of energy at 200 Ms for vision +which you integrated over the whole + + align:start position:0% +which you integrated over the whole + + + align:start position:0% +which you integrated over the whole +volume you can calculate the total + + align:start position:0% +volume you can calculate the total + + + align:start position:0% +volume you can calculate the total +thermal power that that core or + + align:start position:0% +thermal power that that core or + + + align:start position:0% +thermal power that that core or +configuration that you've created + + align:start position:0% +configuration that you've created + + + align:start position:0% +configuration that you've created +assuming it's critical can make and the + + align:start position:0% +assuming it's critical can make and the + + + align:start position:0% +assuming it's critical can make and the +other factor that you need to worry + + align:start position:0% +other factor that you need to worry + + + align:start position:0% +other factor that you need to worry +about is the location of the absorbers + + align:start position:0% +about is the location of the absorbers + + + align:start position:0% +about is the location of the absorbers +and the leakage such + + align:start position:0% +and the leakage such + + + align:start position:0% +and the leakage such +that you don't lose the neutrons or you + + align:start position:0% +that you don't lose the neutrons or you + + + align:start position:0% +that you don't lose the neutrons or you +don't absorb too many of them in either + + align:start position:0% +don't absorb too many of them in either + + + align:start position:0% +don't absorb too many of them in either +the Boron or the steel or the other + + align:start position:0% +the Boron or the steel or the other + + + align:start position:0% +the Boron or the steel or the other +materials and that you can appropriately + + align:start position:0% +materials and that you can appropriately + + + align:start position:0% +materials and that you can appropriately +slow down the neutrons by scattering + + align:start position:0% +slow down the neutrons by scattering + + + align:start position:0% +slow down the neutrons by scattering +them with an appropriate + + align:start position:0% + + + + align:start position:0% + +moderator such that they're not lost or + + align:start position:0% +moderator such that they're not lost or + + + align:start position:0% +moderator such that they're not lost or +absorbed and with that we have completed + + align:start position:0% +absorbed and with that we have completed + + + align:start position:0% +absorbed and with that we have completed +the reactor physics + + align:start position:0% +the reactor physics + + + align:start position:0% +the reactor physics +review and um if you have any questions + + align:start position:0% +review and um if you have any questions + + + align:start position:0% +review and um if you have any questions +please ask your + + align:start position:0% +please ask your + + + align:start position:0% +please ask your +instructor and but this is this is where + + align:start position:0% +instructor and but this is this is where + + + align:start position:0% +instructor and but this is this is where +the rubber meets the road this is the + + align:start position:0% +the rubber meets the road this is the + + + align:start position:0% +the rubber meets the road this is the +bottom line + + align:start position:0% +bottom line + + + align:start position:0% +bottom line +equation and the determining factor is + + align:start position:0% +equation and the determining factor is + + + align:start position:0% +equation and the determining factor is +how is this flux calculated and that's a + + align:start position:0% +how is this flux calculated and that's a + + + align:start position:0% +how is this flux calculated and that's a +function of geometry material bucket and + + align:start position:0% +function of geometry material bucket and + + + align:start position:0% +function of geometry material bucket and +all those combined together that says we + + align:start position:0% +all those combined together that says we + + + align:start position:0% +all those combined together that says we +can keep a reactor + + align:start position:0% + + + + align:start position:0% + +critical at one for 18 to 24 months and + + align:start position:0% +critical at one for 18 to 24 months and + + + align:start position:0% +critical at one for 18 to 24 months and +what that will require + + align:start position:0% +what that will require + + + align:start position:0% +what that will require +is putting enough uranium in + + align:start position:0% +is putting enough uranium in + + + align:start position:0% +is putting enough uranium in +here + + align:start position:0% +here + + + align:start position:0% +here +and having enough depletable poison in + + align:start position:0% +and having enough depletable poison in + + + align:start position:0% +and having enough depletable poison in +here to manage the excess + + align:start position:0% +here to manage the excess + + + align:start position:0% +here to manage the excess +reactivity but not too much so that the + + align:start position:0% +reactivity but not too much so that the + + + align:start position:0% +reactivity but not too much so that the +reactor doesn't shut down + + align:start position:0% +reactor doesn't shut down + + + align:start position:0% +reactor doesn't shut down +prematurely so be happy to answer your + + align:start position:0% +prematurely so be happy to answer your + + + align:start position:0% +prematurely so be happy to answer your +questions uh hopefully you'll ask your + + align:start position:0% +questions uh hopefully you'll ask your + + + align:start position:0% +questions uh hopefully you'll ask your +instructor thank + + align:start position:0% +instructor thank + + + align:start position:0% +instructor thank +you now the homework is is is found in + + align:start position:0% +you now the homework is is is found in + + + align:start position:0% +you now the homework is is is found in +NE chapter 4 and the problems are listed + + align:start position:0% +NE chapter 4 and the problems are listed + + + align:start position:0% +NE chapter 4 and the problems are listed +here above and if you have any questions + + align:start position:0% +here above and if you have any questions + + + align:start position:0% +here above and if you have any questions +about the homework problems again uh ask + + align:start position:0% +about the homework problems again uh ask + + + align:start position:0% +about the homework problems again uh ask +your instructor but this should give you + + align:start position:0% +your instructor but this should give you + + + align:start position:0% +your instructor but this should give you +a good solid review of of some of the + + align:start position:0% +a good solid review of of some of the + + + align:start position:0% +a good solid review of of some of the +things that we talked about in this + + align:start position:0% +things that we talked about in this + + + align:start position:0% +things that we talked about in this +course we're not going to be able to um + + align:start position:0% +course we're not going to be able to um + + + align:start position:0% +course we're not going to be able to um +to run sophisticated computer code + + align:start position:0% +to run sophisticated computer code + + + align:start position:0% +to run sophisticated computer code +but at least you'll get an appreciation + + align:start position:0% +but at least you'll get an appreciation + + + align:start position:0% +but at least you'll get an appreciation +of what it is that's involved in doing a + + align:start position:0% +of what it is that's involved in doing a + + + align:start position:0% +of what it is that's involved in doing a +core reactive physics calculation \ No newline at end of file diff --git a/i5AWE-OoOsY.txt b/i5AWE-OoOsY.txt new file mode 100644 index 0000000000000000000000000000000000000000..4910b387a19112245dec903ad5c5e9f61e8dbbd1 --- /dev/null +++ b/i5AWE-OoOsY.txt @@ -0,0 +1,2795 @@ +align:start position:0% + +so let's get set to State Halls theorem + + align:start position:0% +so let's get set to State Halls theorem + + + align:start position:0% +so let's get set to State Halls theorem +uh in a way that doesn't mention boys + + align:start position:0% +uh in a way that doesn't mention boys + + + align:start position:0% +uh in a way that doesn't mention boys +and girls but let's remember the girl + + align:start position:0% +and girls but let's remember the girl + + + align:start position:0% +and girls but let's remember the girl +boy setup to start so the general setup + + align:start position:0% +boy setup to start so the general setup + + + align:start position:0% +boy setup to start so the general setup +is a bipartite graph h and a bipartite + + align:start position:0% +is a bipartite graph h and a bipartite + + + align:start position:0% +is a bipartite graph h and a bipartite +graph has two sets of vertices um uh the + + align:start position:0% +graph has two sets of vertices um uh the + + + align:start position:0% +graph has two sets of vertices um uh the +girl vertices and the boy vertices + + align:start position:0% +girl vertices and the boy vertices + + + align:start position:0% +girl vertices and the boy vertices +formally there's a set L of H called the + + align:start position:0% +formally there's a set L of H called the + + + align:start position:0% +formally there's a set L of H called the +left vertices of h and a set R of H + + align:start position:0% +left vertices of h and a set R of H + + + align:start position:0% +left vertices of h and a set R of H +called the right vertices of H the + + align:start position:0% +called the right vertices of H the + + + align:start position:0% +called the right vertices of H the +vertices of H altogether are L of H + + align:start position:0% +vertices of H altogether are L of H + + + align:start position:0% +vertices of H altogether are L of H +Union R of H both of these are non-empty + + align:start position:0% +Union R of H both of these are non-empty + + + align:start position:0% +Union R of H both of these are non-empty +and they don't overlap then the edges of + + align:start position:0% +and they don't overlap then the edges of + + + align:start position:0% +and they don't overlap then the edges of +H have the property that they only go + + align:start position:0% +H have the property that they only go + + + align:start position:0% +H have the property that they only go +between L of H and R of H that is the + + align:start position:0% +between L of H and R of H that is the + + + align:start position:0% +between L of H and R of H that is the +definition of a bipartite graph now + + align:start position:0% +definition of a bipartite graph now + + + align:start position:0% +definition of a bipartite graph now +we're interested in a matching in a + + align:start position:0% +we're interested in a matching in a + + + align:start position:0% +we're interested in a matching in a +bipartite graph so let's be precise + + align:start position:0% +bipartite graph so let's be precise + + + align:start position:0% +bipartite graph so let's be precise +again what's a matching without having + + align:start position:0% +again what's a matching without having + + + align:start position:0% +again what's a matching without having +to mention boys and girls and likes um a + + align:start position:0% +to mention boys and girls and likes um a + + + align:start position:0% +to mention boys and girls and likes um a +match is a total injective function from + + align:start position:0% +match is a total injective function from + + + align:start position:0% +match is a total injective function from +the left vertices to the right vertices + + align:start position:0% +the left vertices to the right vertices + + + align:start position:0% +the left vertices to the right vertices +so that means every um L Vertex or girl + + align:start position:0% +so that means every um L Vertex or girl + + + align:start position:0% +so that means every um L Vertex or girl +has a match M of L that is on the other + + align:start position:0% +has a match M of L that is on the other + + + align:start position:0% +has a match M of L that is on the other +side so and we we need this total + + align:start position:0% +side so and we we need this total + + + align:start position:0% +side so and we we need this total +injective function match function M to + + align:start position:0% +injective function match function M to + + + align:start position:0% +injective function match function M to +follow the edges what does follow the + + align:start position:0% +follow the edges what does follow the + + + align:start position:0% +follow the edges what does follow the +edges mean precisely it simply means + + align:start position:0% +edges mean precisely it simply means + + + align:start position:0% +edges mean precisely it simply means +that the edge l m of L is a legitimate + + align:start position:0% +that the edge l m of L is a legitimate + + + align:start position:0% +that the edge l m of L is a legitimate +edge of H another way to say that is + + align:start position:0% +edge of H another way to say that is + + + align:start position:0% +edge of H another way to say that is +that the graph of this total injective + + align:start position:0% +that the graph of this total injective + + + align:start position:0% +that the graph of this total injective +function is a subset of the edges of a + + align:start position:0% +function is a subset of the edges of a + + + align:start position:0% +function is a subset of the edges of a +so we can State the not bottleneck + + align:start position:0% +so we can State the not bottleneck + + + align:start position:0% +so we can State the not bottleneck +condition H's condition as + + align:start position:0% +condition H's condition as + + + align:start position:0% +condition H's condition as +follows if the size of s is less than or + + align:start position:0% +follows if the size of s is less than or + + + align:start position:0% +follows if the size of s is less than or +equal to its image under the edges for + + align:start position:0% +equal to its image under the edges for + + + align:start position:0% +equal to its image under the edges for +every set of left vertices H that's + + align:start position:0% +every set of left vertices H that's + + + align:start position:0% +every set of left vertices H that's +called Halls condition that the size of + + align:start position:0% +called Halls condition that the size of + + + align:start position:0% +called Halls condition that the size of +s is less than or equal to the image of + + align:start position:0% +s is less than or equal to the image of + + + align:start position:0% +s is less than or equal to the image of +s for every + + align:start position:0% +s for every + + + align:start position:0% +s for every +s then there is a match so this is a way + + align:start position:0% +s then there is a match so this is a way + + + align:start position:0% +s then there is a match so this is a way +of precisely stating holse theorem no + + align:start position:0% +of precisely stating holse theorem no + + + align:start position:0% +of precisely stating holse theorem no +boys and girls mentioned we'll be + + align:start position:0% +boys and girls mentioned we'll be + + + align:start position:0% +boys and girls mentioned we'll be +comfortable going back to the boy girl + + align:start position:0% +comfortable going back to the boy girl + + + align:start position:0% +comfortable going back to the boy girl +language because it's it's more + + align:start position:0% +language because it's it's more + + + align:start position:0% +language because it's it's more +memorable and easier to talk about but + + align:start position:0% +memorable and easier to talk about but + + + align:start position:0% +memorable and easier to talk about but +just for the record we have now formally + + align:start position:0% +just for the record we have now formally + + + align:start position:0% +just for the record we have now formally +stated defined bipartite graphs matches + + align:start position:0% +stated defined bipartite graphs matches + + + align:start position:0% +stated defined bipartite graphs matches +in bipartite graphs and Halls theorem um + + align:start position:0% +in bipartite graphs and Halls theorem um + + + align:start position:0% +in bipartite graphs and Halls theorem um +uh Halls theorem really uh that there is + + align:start position:0% +uh Halls theorem really uh that there is + + + align:start position:0% +uh Halls theorem really uh that there is +a match when Halls condition is + + align:start position:0% +a match when Halls condition is + + + align:start position:0% +a match when Halls condition is +satisfied um without mentioning boys and + + align:start position:0% +satisfied um without mentioning boys and + + + align:start position:0% +satisfied um without mentioning boys and +girls + + align:start position:0% +girls + + + align:start position:0% +girls +okay the puzzle is how do you verify + + align:start position:0% +okay the puzzle is how do you verify + + + align:start position:0% +okay the puzzle is how do you verify +that there are no bottlenecks it's + + align:start position:0% +that there are no bottlenecks it's + + + align:start position:0% +that there are no bottlenecks it's +pretty hard the bottleneck condition + + align:start position:0% +pretty hard the bottleneck condition + + + align:start position:0% +pretty hard the bottleneck condition +involves checking that every subset s of + + align:start position:0% +involves checking that every subset s of + + + align:start position:0% +involves checking that every subset s of +L ofh satisfies this cardinality + + align:start position:0% +L ofh satisfies this cardinality + + + align:start position:0% +L ofh satisfies this cardinality +condition and there are a lot of subsets + + align:start position:0% +condition and there are a lot of subsets + + + align:start position:0% +condition and there are a lot of subsets +of L ofh relative to the size of the + + align:start position:0% +of L ofh relative to the size of the + + + align:start position:0% +of L ofh relative to the size of the +graph exponentially many so we can ask + + align:start position:0% +graph exponentially many so we can ask + + + align:start position:0% +graph exponentially many so we can ask +how do you verify that there are no + + align:start position:0% +how do you verify that there are no + + + align:start position:0% +how do you verify that there are no +bottlenecks well it turns out in + + align:start position:0% +bottlenecks well it turns out in + + + align:start position:0% +bottlenecks well it turns out in +algorithms classes you will learn uh a + + align:start position:0% +algorithms classes you will learn uh a + + + align:start position:0% +algorithms classes you will learn uh a +fairly efficient matching procedure uh + + align:start position:0% +fairly efficient matching procedure uh + + + align:start position:0% +fairly efficient matching procedure uh +runs about + + align:start position:0% +runs about + + + align:start position:0% +runs about +quadratically um for uh finding M + + align:start position:0% +quadratically um for uh finding M + + + align:start position:0% +quadratically um for uh finding M +perfect matches when they exist um but + + align:start position:0% +perfect matches when they exist um but + + + align:start position:0% +perfect matches when they exist um but +there's one particular special case uh + + align:start position:0% +there's one particular special case uh + + + align:start position:0% +there's one particular special case uh +that ensures no bottlenecks that we'll + + align:start position:0% +that ensures no bottlenecks that we'll + + + align:start position:0% +that ensures no bottlenecks that we'll +have to that we'll be making use of + + align:start position:0% +have to that we'll be making use of + + + align:start position:0% +have to that we'll be making use of +several times in the term and that + + align:start position:0% +several times in the term and that + + + align:start position:0% +several times in the term and that +special situation is when um it turns + + align:start position:0% +special situation is when um it turns + + + align:start position:0% +special situation is when um it turns +out that every girl likes at least D + + align:start position:0% +out that every girl likes at least D + + + align:start position:0% +out that every girl likes at least D +boys and every boy likes at most D girls + + align:start position:0% +boys and every boy likes at most D girls + + + align:start position:0% +boys and every boy likes at most D girls +this is called a degree constrained + + align:start position:0% +this is called a degree constrained + + + align:start position:0% +this is called a degree constrained +graph if a graph is DEC constrained uh + + align:start position:0% +graph if a graph is DEC constrained uh + + + align:start position:0% +graph if a graph is DEC constrained uh +is degree constrained then there are no + + align:start position:0% +is degree constrained then there are no + + + align:start position:0% +is degree constrained then there are no +model next so this condition that there + + align:start position:0% +model next so this condition that there + + + align:start position:0% +model next so this condition that there +are at least d uh each girl likes at + + align:start position:0% +are at least d uh each girl likes at + + + align:start position:0% +are at least d uh each girl likes at +least D boys and every boy likes it at + + align:start position:0% +least D boys and every boy likes it at + + + align:start position:0% +least D boys and every boy likes it at +most D girls could have been rephrased + + align:start position:0% +most D girls could have been rephrased + + + align:start position:0% +most D girls could have been rephrased +as saying that the minimum degree of the + + align:start position:0% +as saying that the minimum degree of the + + + align:start position:0% +as saying that the minimum degree of the +girls is greater than or equal to the uh + + align:start position:0% +girls is greater than or equal to the uh + + + align:start position:0% +girls is greater than or equal to the uh +maximum degree of the boys but I think + + align:start position:0% +maximum degree of the boys but I think + + + align:start position:0% +maximum degree of the boys but I think +expressing it in terms of D is maybe + + align:start position:0% +expressing it in terms of D is maybe + + + align:start position:0% +expressing it in terms of D is maybe +makes it a little + + align:start position:0% +makes it a little + + + align:start position:0% +makes it a little +clearer okay um let's prove this uh I'm + + align:start position:0% +clearer okay um let's prove this uh I'm + + + align:start position:0% +clearer okay um let's prove this uh I'm +going to prove that if you have a + + align:start position:0% +going to prove that if you have a + + + align:start position:0% +going to prove that if you have a +constra a degree constrained bipartite + + align:start position:0% +constra a degree constrained bipartite + + + align:start position:0% +constra a degree constrained bipartite +graph then it in fact satisfies Hall's + + align:start position:0% +graph then it in fact satisfies Hall's + + + align:start position:0% +graph then it in fact satisfies Hall's +condition there are no + + align:start position:0% +condition there are no + + + align:start position:0% +condition there are no +bottlenecks so we have that if every + + align:start position:0% +bottlenecks so we have that if every + + + align:start position:0% +bottlenecks so we have that if every +girl likes at least D boys and every boy + + align:start position:0% +girl likes at least D boys and every boy + + + align:start position:0% +girl likes at least D boys and every boy +likes at most D girls there are no + + align:start position:0% +likes at most D girls there are no + + + align:start position:0% +likes at most D girls there are no +bottlenecks the proof goes as follows + + align:start position:0% +bottlenecks the proof goes as follows + + + align:start position:0% +bottlenecks the proof goes as follows +let's look at some arbitrary set s of + + align:start position:0% +let's look at some arbitrary set s of + + + align:start position:0% +let's look at some arbitrary set s of +girls um and suppose that the total + + align:start position:0% +girls um and suppose that the total + + + align:start position:0% +girls um and suppose that the total +number of edges that are incident to S + + align:start position:0% +number of edges that are incident to S + + + align:start position:0% +number of edges that are incident to S +um are uh has cardinality e there are e + + align:start position:0% +um are uh has cardinality e there are e + + + align:start position:0% +um are uh has cardinality e there are e +edges that touch vertices in s okay well + + align:start position:0% +edges that touch vertices in s okay well + + + align:start position:0% +edges that touch vertices in s okay well +that tells us that since every vertex in + + align:start position:0% +that tells us that since every vertex in + + + align:start position:0% +that tells us that since every vertex in +s has at least D edges out maybe more D + + align:start position:0% +s has at least D edges out maybe more D + + + align:start position:0% +s has at least D edges out maybe more D +times the size of s has to be less than + + align:start position:0% +times the size of s has to be less than + + + align:start position:0% +times the size of s has to be less than +or equal to the total number of edges + + align:start position:0% +or equal to the total number of edges + + + align:start position:0% +or equal to the total number of edges +coming out of + + align:start position:0% +coming out of + + + align:start position:0% +coming out of +s likewise um all of the edges that come + + align:start position:0% +s likewise um all of the edges that come + + + align:start position:0% +s likewise um all of the edges that come +out of s go by definition into e of s + + align:start position:0% +out of s go by definition into e of s + + + align:start position:0% +out of s go by definition into e of s +and each vertex in E of s can only + + align:start position:0% +and each vertex in E of s can only + + + align:start position:0% +and each vertex in E of s can only +absorb the edges D girls so that means + + align:start position:0% +absorb the edges D girls so that means + + + align:start position:0% +absorb the edges D girls so that means +that the total number of edges absorbed + + align:start position:0% +that the total number of edges absorbed + + + align:start position:0% +that the total number of edges absorbed +by E of s that is at most D * e of s had + + align:start position:0% +by E of s that is at most D * e of s had + + + align:start position:0% +by E of s that is at most D * e of s had +better be bigger than the number of + + align:start position:0% +better be bigger than the number of + + + align:start position:0% +better be bigger than the number of +edges that have to be absorbed e so we + + align:start position:0% +edges that have to be absorbed e so we + + + align:start position:0% +edges that have to be absorbed e so we +get that D * the size of s is less than + + align:start position:0% +get that D * the size of s is less than + + + align:start position:0% +get that D * the size of s is less than +or equal to the total number of edges + + align:start position:0% +or equal to the total number of edges + + + align:start position:0% +or equal to the total number of edges +incident to S Which is less than or + + align:start position:0% +incident to S Which is less than or + + + align:start position:0% +incident to S Which is less than or +equal to D time the the total the total + + align:start position:0% +equal to D time the the total the total + + + align:start position:0% +equal to D time the the total the total +number of vertices in E of s well cancel + + align:start position:0% +number of vertices in E of s well cancel + + + align:start position:0% +number of vertices in E of s well cancel +the D's and we have that the size of s + + align:start position:0% +the D's and we have that the size of s + + + align:start position:0% +the D's and we have that the size of s +is less than or equal to the size of its + + align:start position:0% +is less than or equal to the size of its + + + align:start position:0% +is less than or equal to the size of its +image that's the definition of a + + align:start position:0% +image that's the definition of a + + + align:start position:0% +image that's the definition of a +bottleneck the violation of that would + + align:start position:0% +bottleneck the violation of that would + + + align:start position:0% +bottleneck the violation of that would +be a bottleneck this says there's no + + align:start position:0% +be a bottleneck this says there's no + + + align:start position:0% +be a bottleneck this says there's no +bottlenecks and we have proved the + + align:start position:0% +bottlenecks and we have proved the + + + align:start position:0% +bottlenecks and we have proved the +degree constraint condition is + + align:start position:0% +degree constraint condition is + + + align:start position:0% +degree constraint condition is +sufficient to verify Hall's condition + + align:start position:0% +sufficient to verify Hall's condition + + + align:start position:0% +sufficient to verify Hall's condition +and by Hall's theorem it's sufficient to + + align:start position:0% +and by Hall's theorem it's sufficient to + + + align:start position:0% +and by Hall's theorem it's sufficient to +guarantee that there is a match now + + align:start position:0% +guarantee that there is a match now + + + align:start position:0% +guarantee that there is a match now +there's a lot of graphs with matches + + align:start position:0% +there's a lot of graphs with matches + + + align:start position:0% +there's a lot of graphs with matches +that are not degree constrained this is + + align:start position:0% +that are not degree constrained this is + + + align:start position:0% +that are not degree constrained this is +not an if and only if theorem it's just + + align:start position:0% +not an if and only if theorem it's just + + + align:start position:0% +not an if and only if theorem it's just +a sufficient condition that comes up + + align:start position:0% +a sufficient condition that comes up + + + align:start position:0% +a sufficient condition that comes up +often enough that it's worth mentioning + + align:start position:0% +often enough that it's worth mentioning + + + align:start position:0% +often enough that it's worth mentioning +the Greek constraint implies Hall's + + align:start position:0% +the Greek constraint implies Hall's + + + align:start position:0% +the Greek constraint implies Hall's +condition is satisfied which implies + + align:start position:0% +condition is satisfied which implies + + + align:start position:0% +condition is satisfied which implies +that there's a perfect + + align:start position:0% +that there's a perfect + + + align:start position:0% +that there's a perfect +match so let's turn now to the general + + align:start position:0% +match so let's turn now to the general + + + align:start position:0% +match so let's turn now to the general +case of Halls theorem and let's talk + + align:start position:0% +case of Halls theorem and let's talk + + + align:start position:0% +case of Halls theorem and let's talk +about proving Halls theorem HSE theorem + + align:start position:0% +about proving Halls theorem HSE theorem + + + align:start position:0% +about proving Halls theorem HSE theorem +says that if there's no bottleneck then + + align:start position:0% +says that if there's no bottleneck then + + + align:start position:0% +says that if there's no bottleneck then +there is a match so let's begin by + + align:start position:0% +there is a match so let's begin by + + + align:start position:0% +there is a match so let's begin by +setting up a Lemma that will play a + + align:start position:0% +setting up a Lemma that will play a + + + align:start position:0% +setting up a Lemma that will play a +crucial role the strategy for showing a + + align:start position:0% +crucial role the strategy for showing a + + + align:start position:0% +crucial role the strategy for showing a +for proving it is basically going to be + + align:start position:0% +for proving it is basically going to be + + + align:start position:0% +for proving it is basically going to be +to try to break the problem of finding a + + align:start position:0% +to try to break the problem of finding a + + + align:start position:0% +to try to break the problem of finding a +match for a large set of vertices into + + align:start position:0% +match for a large set of vertices into + + + align:start position:0% +match for a large set of vertices into +sub problems of finding matches for + + align:start position:0% +sub problems of finding matches for + + + align:start position:0% +sub problems of finding matches for +smaller sets of vertices uh and by in by + + align:start position:0% +smaller sets of vertices uh and by in by + + + align:start position:0% +smaller sets of vertices uh and by in by +strong induction Halls condition will + + align:start position:0% +strong induction Halls condition will + + + align:start position:0% +strong induction Halls condition will +apply to the subsets and will win let's + + align:start position:0% +apply to the subsets and will win let's + + + align:start position:0% +apply to the subsets and will win let's +look at that more carefully so let's + + align:start position:0% +look at that more carefully so let's + + + align:start position:0% +look at that more carefully so let's +begin by supposing that there are no + + align:start position:0% +begin by supposing that there are no + + + align:start position:0% +begin by supposing that there are no +bottlenecks in some bipartite graph H + + align:start position:0% +bottlenecks in some bipartite graph H + + + align:start position:0% +bottlenecks in some bipartite graph H +well in particular if there's no + + align:start position:0% +well in particular if there's no + + + align:start position:0% +well in particular if there's no +bottlenecks anywhere then if you + + align:start position:0% +bottlenecks anywhere then if you + + + align:start position:0% +bottlenecks anywhere then if you +restrict s to some set s of girls no + + align:start position:0% +restrict s to some set s of girls no + + + align:start position:0% +restrict s to some set s of girls no +subset of that set s is going to have a + + align:start position:0% +subset of that set s is going to have a + + + align:start position:0% +subset of that set s is going to have a +bottleneck obviously because a + + align:start position:0% +bottleneck obviously because a + + + align:start position:0% +bottleneck obviously because a +bottleneck within s would be a + + align:start position:0% +bottleneck within s would be a + + + align:start position:0% +bottleneck within s would be a +bottleneck within the whole graph so + + align:start position:0% +bottleneck within the whole graph so + + + align:start position:0% +bottleneck within the whole graph so +that part's trivial what's not trivial + + align:start position:0% +that part's trivial what's not trivial + + + align:start position:0% +that part's trivial what's not trivial +and takes a little bit of arguing is + + align:start position:0% +and takes a little bit of arguing is + + + align:start position:0% +and takes a little bit of arguing is +that suppose you have a set of girls + + align:start position:0% +that suppose you have a set of girls + + + align:start position:0% +that suppose you have a set of girls +that with the property that the number + + align:start position:0% +that with the property that the number + + + align:start position:0% +that with the property that the number +of boys that are compatible with that + + align:start position:0% +of boys that are compatible with that + + + align:start position:0% +of boys that are compatible with that +set of girls is exactly the same as the + + align:start position:0% +set of girls is exactly the same as the + + + align:start position:0% +set of girls is exactly the same as the +number of girls so technically the size + + align:start position:0% +number of girls so technically the size + + + align:start position:0% +number of girls so technically the size +of s is equal to the size of e of s in + + align:start position:0% +of s is equal to the size of e of s in + + + align:start position:0% +of s is equal to the size of e of s in +that case we can uh argue that there + + align:start position:0% +that case we can uh argue that there + + + align:start position:0% +that case we can uh argue that there +aren't any bottlenecks within the + + align:start position:0% +aren't any bottlenecks within the + + + align:start position:0% +aren't any bottlenecks within the +complement of s and the complement of e + + align:start position:0% +complement of s and the complement of e + + + align:start position:0% +complement of s and the complement of e +of s either well let's look at a picture + + align:start position:0% +of s either well let's look at a picture + + + align:start position:0% +of s either well let's look at a picture +to illustrate what's going on so here we + + align:start position:0% +to illustrate what's going on so here we + + + align:start position:0% +to illustrate what's going on so here we +have h a bipartite graph and there's s + + align:start position:0% +have h a bipartite graph and there's s + + + align:start position:0% +have h a bipartite graph and there's s +and its image on the right e of s okay + + align:start position:0% +and its image on the right e of s okay + + + align:start position:0% +and its image on the right e of s okay +now we're interested in and we know that + + align:start position:0% +now we're interested in and we know that + + + align:start position:0% +now we're interested in and we know that +a a bottleneck here would imply a + + align:start position:0% +a a bottleneck here would imply a + + + align:start position:0% +a a bottleneck here would imply a +bottleneck in the whole graph what we + + align:start position:0% +bottleneck in the whole graph what we + + + align:start position:0% +bottleneck in the whole graph what we +want to argue is that a bottleneck in + + align:start position:0% +want to argue is that a bottleneck in + + + align:start position:0% +want to argue is that a bottleneck in +the complement of s would imply a + + align:start position:0% +the complement of s would imply a + + + align:start position:0% +the complement of s would imply a +bottleneck in the complement of e of s + + align:start position:0% +bottleneck in the complement of e of s + + + align:start position:0% +bottleneck in the complement of e of s +so there's the complement of e of s and + + align:start position:0% +so there's the complement of e of s and + + + align:start position:0% +so there's the complement of e of s and +there's the complement of s now notice + + align:start position:0% +there's the complement of s now notice + + + align:start position:0% +there's the complement of s now notice +that some edges that come out of the + + align:start position:0% +that some edges that come out of the + + + align:start position:0% +that some edges that come out of the +compl of s may very well go into e of s + + align:start position:0% +compl of s may very well go into e of s + + + align:start position:0% +compl of s may very well go into e of s +that is this would be a point that's + + align:start position:0% +that is this would be a point that's + + + align:start position:0% +that is this would be a point that's +both in E of s and an EFS complement but + + align:start position:0% +both in E of s and an EFS complement but + + + align:start position:0% +both in E of s and an EFS complement but +we're not allowed to use that point + + align:start position:0% +we're not allowed to use that point + + + align:start position:0% +we're not allowed to use that point +because we're trying to find a match + + align:start position:0% +because we're trying to find a match + + + align:start position:0% +because we're trying to find a match +only within SAR and E of SAR and and + + align:start position:0% +only within SAR and E of SAR and and + + + align:start position:0% +only within SAR and E of SAR and and +what we're really trying to argue is + + align:start position:0% +what we're really trying to argue is + + + align:start position:0% +what we're really trying to argue is +that a bottleneck here would imply a + + align:start position:0% +that a bottleneck here would imply a + + + align:start position:0% +that a bottleneck here would imply a +bottleneck in the whole graph so let's + + align:start position:0% +bottleneck in the whole graph so let's + + + align:start position:0% +bottleneck in the whole graph so let's +see if we can argue this there's no we + + align:start position:0% +see if we can argue this there's no we + + + align:start position:0% +see if we can argue this there's no we +want to claim that there's no bottleneck + + align:start position:0% +want to claim that there's no bottleneck + + + align:start position:0% +want to claim that there's no bottleneck +between SAR and E of S Bar given that + + align:start position:0% +between SAR and E of S Bar given that + + + align:start position:0% +between SAR and E of S Bar given that +there's no bottleneck anywhere um + + align:start position:0% +there's no bottleneck anywhere um + + + align:start position:0% +there's no bottleneck anywhere um +and uh when S and E of s are the same + + align:start position:0% +and uh when S and E of s are the same + + + align:start position:0% +and uh when S and E of s are the same +size so let's suppose that we had a set + + align:start position:0% +size so let's suppose that we had a set + + + align:start position:0% +size so let's suppose that we had a set +T over here that was a subset of SAR and + + align:start position:0% +T over here that was a subset of SAR and + + + align:start position:0% +T over here that was a subset of SAR and +let's look at its image over here in + + align:start position:0% +let's look at its image over here in + + + align:start position:0% +let's look at its image over here in +Orange so we've got that the image of + + align:start position:0% +Orange so we've got that the image of + + + align:start position:0% +Orange so we've got that the image of +this set T when we restrict it just to + + align:start position:0% +this set T when we restrict it just to + + + align:start position:0% +this set T when we restrict it just to +the part that's in the complement of s + + align:start position:0% +the part that's in the complement of s + + + align:start position:0% +the part that's in the complement of s +notice I'm leaving out this point here + + align:start position:0% +notice I'm leaving out this point here + + + align:start position:0% +notice I'm leaving out this point here +I'm not taking the image of T I'm taking + + align:start position:0% +I'm not taking the image of T I'm taking + + + align:start position:0% +I'm not taking the image of T I'm taking +the image of T restricted to the points + + align:start position:0% +the image of T restricted to the points + + + align:start position:0% +the image of T restricted to the points +that are not in the image of s and what + + align:start position:0% +that are not in the image of s and what + + + align:start position:0% +that are not in the image of s and what +I want to know is could that cause a + + align:start position:0% +I want to know is could that cause a + + + align:start position:0% +I want to know is could that cause a +bottleneck after all I've left out some + + align:start position:0% +bottleneck after all I've left out some + + + align:start position:0% +bottleneck after all I've left out some +points that used to be included in the + + align:start position:0% +points that used to be included in the + + + align:start position:0% +points that used to be included in the +image of T and so the image of T might + + align:start position:0% +image of T and so the image of T might + + + align:start position:0% +image of T and so the image of T might +have been small so the image of T might + + align:start position:0% +have been small so the image of T might + + + align:start position:0% +have been small so the image of T might +have been bigger than T because of those + + align:start position:0% +have been bigger than T because of those + + + align:start position:0% +have been bigger than T because of those +extra points that I'm leaving out I have + + align:start position:0% +extra points that I'm leaving out I have + + + align:start position:0% +extra points that I'm leaving out I have +to be sure that that doesn't happen + + align:start position:0% +to be sure that that doesn't happen + + + align:start position:0% +to be sure that that doesn't happen +could there be a bottleneck that has + + align:start position:0% +could there be a bottleneck that has + + + align:start position:0% +could there be a bottleneck that has +been created by these points that I've + + align:start position:0% +been created by these points that I've + + + align:start position:0% +been created by these points that I've +left out could there be a bottleneck in + + align:start position:0% +left out could there be a bottleneck in + + + align:start position:0% +left out could there be a bottleneck in +E of T intersection the complement of e + + align:start position:0% +E of T intersection the complement of e + + + align:start position:0% +E of T intersection the complement of e +of s could that orange guy be a + + align:start position:0% +of s could that orange guy be a + + + align:start position:0% +of s could that orange guy be a +bottleneck well if it was a bottleneck + + align:start position:0% +bottleneck well if it was a bottleneck + + + align:start position:0% +bottleneck well if it was a bottleneck +then I'd have a bottleneck in the whole + + align:start position:0% +then I'd have a bottleneck in the whole + + + align:start position:0% +then I'd have a bottleneck in the whole +graph and that's because S and E of s + + align:start position:0% +graph and that's because S and E of s + + + align:start position:0% +graph and that's because S and E of s +are the same size cuz all I do is if I + + align:start position:0% +are the same size cuz all I do is if I + + + align:start position:0% +are the same size cuz all I do is if I +had a bottleneck there I would take this + + align:start position:0% +had a bottleneck there I would take this + + + align:start position:0% +had a bottleneck there I would take this +set T along with s and this set orange + + align:start position:0% +set T along with s and this set orange + + + align:start position:0% +set T along with s and this set orange +along with e of s and that would be a + + align:start position:0% +along with e of s and that would be a + + + align:start position:0% +along with e of s and that would be a +bottleneck because now if you look at + + align:start position:0% +bottleneck because now if you look at + + + align:start position:0% +bottleneck because now if you look at +the size of T I've added the same amount + + align:start position:0% +the size of T I've added the same amount + + + align:start position:0% +the size of T I've added the same amount +to the size of t as I've added to that + + align:start position:0% +to the size of t as I've added to that + + + align:start position:0% +to the size of t as I've added to that +orange set CU e of S and S of the same + + align:start position:0% +orange set CU e of S and S of the same + + + align:start position:0% +orange set CU e of S and S of the same +size so if this orange part was smaller + + align:start position:0% +size so if this orange part was smaller + + + align:start position:0% +size so if this orange part was smaller +than T then orange part along with e of + + align:start position:0% +than T then orange part along with e of + + + align:start position:0% +than T then orange part along with e of +s is smaller than T Union s and that + + align:start position:0% +s is smaller than T Union s and that + + + align:start position:0% +s is smaller than T Union s and that +defines a bottleneck in the whole graph + + align:start position:0% +defines a bottleneck in the whole graph + + + align:start position:0% +defines a bottleneck in the whole graph +so again if there was a bottleneck in + + align:start position:0% +so again if there was a bottleneck in + + + align:start position:0% +so again if there was a bottleneck in +here caused by restricting images to the + + align:start position:0% +here caused by restricting images to the + + + align:start position:0% +here caused by restricting images to the +complement of e of s it means there was + + align:start position:0% +complement of e of s it means there was + + + align:start position:0% +complement of e of s it means there was +a bottleneck in the whole graph if + + align:start position:0% +a bottleneck in the whole graph if + + + align:start position:0% +a bottleneck in the whole graph if +there's no bottleneck at all then indeed + + align:start position:0% +there's no bottleneck at all then indeed + + + align:start position:0% +there's no bottleneck at all then indeed +there's no bottleneck in this other part + + align:start position:0% +there's no bottleneck in this other part + + + align:start position:0% +there's no bottleneck in this other part +of the complement of s and the compl of + + align:start position:0% +of the complement of s and the compl of + + + align:start position:0% +of the complement of s and the compl of +e of s and this gives me a hook on + + align:start position:0% +e of s and this gives me a hook on + + + align:start position:0% +e of s and this gives me a hook on +proving Halls theorem cuz that's + + align:start position:0% +proving Halls theorem cuz that's + + + align:start position:0% +proving Halls theorem cuz that's +basically the the way I'm going to split + + align:start position:0% +basically the the way I'm going to split + + + align:start position:0% +basically the the way I'm going to split +the problem into two separate matching + + align:start position:0% +the problem into two separate matching + + + align:start position:0% +the problem into two separate matching +parts so let's now proceed to prove that + + align:start position:0% +parts so let's now proceed to prove that + + + align:start position:0% +parts so let's now proceed to prove that +if there are no bottlenecks in a graph + + align:start position:0% +if there are no bottlenecks in a graph + + + align:start position:0% +if there are no bottlenecks in a graph +then there's a perfect match and it's + + align:start position:0% +then there's a perfect match and it's + + + align:start position:0% +then there's a perfect match and it's +going to be by strong induction on the + + align:start position:0% +going to be by strong induction on the + + + align:start position:0% +going to be by strong induction on the +number of girls so case one is the case + + align:start position:0% +number of girls so case one is the case + + + align:start position:0% +number of girls so case one is the case +that we just examined that there's a + + align:start position:0% +that we just examined that there's a + + + align:start position:0% +that we just examined that there's a +non-empty subset of girls a proper + + align:start position:0% +non-empty subset of girls a proper + + + align:start position:0% +non-empty subset of girls a proper +subset not all the girls some subset of + + align:start position:0% +subset not all the girls some subset of + + + align:start position:0% +subset not all the girls some subset of +girls um who another way to say it is + + align:start position:0% +girls um who another way to say it is + + + align:start position:0% +girls um who another way to say it is +there's a subset of girls that's not + + align:start position:0% +there's a subset of girls that's not + + + align:start position:0% +there's a subset of girls that's not +empty and its compliment is not empty + + align:start position:0% +empty and its compliment is not empty + + + align:start position:0% +empty and its compliment is not empty +either and the size of s is the same as + + align:start position:0% +either and the size of s is the same as + + + align:start position:0% +either and the size of s is the same as +the size of e of s that is the number of + + align:start position:0% +the size of e of s that is the number of + + + align:start position:0% +the size of e of s that is the number of +boys that are compatible with this set + + align:start position:0% +boys that are compatible with this set + + + align:start position:0% +boys that are compatible with this set +of girls is exactly the same size as + + align:start position:0% +of girls is exactly the same size as + + + align:start position:0% +of girls is exactly the same size as +this set of girls well if there's going + + align:start position:0% +this set of girls well if there's going + + + align:start position:0% +this set of girls well if there's going +to be a match there has to be one in + + align:start position:0% +to be a match there has to be one in + + + align:start position:0% +to be a match there has to be one in +that subset and um by the lemas there'll + + align:start position:0% +that subset and um by the lemas there'll + + + align:start position:0% +that subset and um by the lemas there'll +be if there's no bottlenecks anywhere + + align:start position:0% +be if there's no bottlenecks anywhere + + + align:start position:0% +be if there's no bottlenecks anywhere +there's no bottlenecks when I restrict + + align:start position:0% +there's no bottlenecks when I restrict + + + align:start position:0% +there's no bottlenecks when I restrict +myself to just S and E of s and also by + + align:start position:0% +myself to just S and E of s and also by + + + align:start position:0% +myself to just S and E of s and also by +the previous Lemma there's no bottleneck + + align:start position:0% +the previous Lemma there's no bottleneck + + + align:start position:0% +the previous Lemma there's no bottleneck +in the complement of s and + + align:start position:0% +in the complement of s and + + + align:start position:0% +in the complement of s and +restricted to the the uh the vertices in + + align:start position:0% +restricted to the the uh the vertices in + + + align:start position:0% +restricted to the the uh the vertices in +E ofs so this is a new bipartite graph + + align:start position:0% +E ofs so this is a new bipartite graph + + + align:start position:0% +E ofs so this is a new bipartite graph +where I'm using S for the left vertices + + align:start position:0% +where I'm using S for the left vertices + + + align:start position:0% +where I'm using S for the left vertices +and E of s for the right vertices and + + align:start position:0% +and E of s for the right vertices and + + + align:start position:0% +and E of s for the right vertices and +here I'm using the complement of s for + + align:start position:0% +here I'm using the complement of s for + + + align:start position:0% +here I'm using the complement of s for +the left vertices and the compl of e ofs + + align:start position:0% +the left vertices and the compl of e ofs + + + align:start position:0% +the left vertices and the compl of e ofs +for the right vertices and we and the + + align:start position:0% +for the right vertices and we and the + + + align:start position:0% +for the right vertices and we and the +previous Lemma says that if there's no + + align:start position:0% +previous Lemma says that if there's no + + + align:start position:0% +previous Lemma says that if there's no +bottlenecks overall there's no + + align:start position:0% +bottlenecks overall there's no + + + align:start position:0% +bottlenecks overall there's no +bottlenecks in either of these two + + align:start position:0% +bottlenecks in either of these two + + + align:start position:0% +bottlenecks in either of these two +restricted graphs so what I can do now + + align:start position:0% +restricted graphs so what I can do now + + + align:start position:0% +restricted graphs so what I can do now +is by induction since there's no + + align:start position:0% +is by induction since there's no + + + align:start position:0% +is by induction since there's no +bottlenecks in s e ofs I can find a + + align:start position:0% +bottlenecks in s e ofs I can find a + + + align:start position:0% +bottlenecks in s e ofs I can find a +match there so I can match up all of the + + align:start position:0% +match there so I can match up all of the + + + align:start position:0% +match there so I can match up all of the +girls in s with compatible Boys in E of + + align:start position:0% +girls in s with compatible Boys in E of + + + align:start position:0% +girls in s with compatible Boys in E of +s and I can match up all of the girls + + align:start position:0% +s and I can match up all of the girls + + + align:start position:0% +s and I can match up all of the girls +that are not in s in the complement of s + + align:start position:0% +that are not in s in the complement of s + + + align:start position:0% +that are not in s in the complement of s +with boys that I haven't used already + + align:start position:0% +with boys that I haven't used already + + + align:start position:0% +with boys that I haven't used already +and there'll be a perfect match there + + align:start position:0% +and there'll be a perfect match there + + + align:start position:0% +and there'll be a perfect match there +and then these two separately will + + align:start position:0% +and then these two separately will + + + align:start position:0% +and then these two separately will +combine will provide a match for the + + align:start position:0% +combine will provide a match for the + + + align:start position:0% +combine will provide a match for the +entire set um of left vertices s Union + + align:start position:0% +entire set um of left vertices s Union + + + align:start position:0% +entire set um of left vertices s Union +the complement of s will be all of the + + align:start position:0% +the complement of s will be all of the + + + align:start position:0% +the complement of s will be all of the +vertices + + align:start position:0% +vertices + + + align:start position:0% +vertices +so and these two matchings don't overlap + + align:start position:0% +so and these two matchings don't overlap + + + align:start position:0% +so and these two matchings don't overlap +so they the they're combining them gives + + align:start position:0% +so they the they're combining them gives + + + align:start position:0% +so they the they're combining them gives +a complete matching that knocks off this + + align:start position:0% +a complete matching that knocks off this + + + align:start position:0% +a complete matching that knocks off this +case that's the nice case where I can + + align:start position:0% +case that's the nice case where I can + + + align:start position:0% +case that's the nice case where I can +find some subset where the number of + + align:start position:0% +find some subset where the number of + + + align:start position:0% +find some subset where the number of +boys is exactly equal to the number of + + align:start position:0% +boys is exactly equal to the number of + + + align:start position:0% +boys is exactly equal to the number of +girls which means that that has to work + + align:start position:0% +girls which means that that has to work + + + align:start position:0% +girls which means that that has to work +by itself and I work that one by itself + + align:start position:0% +by itself and I work that one by itself + + + align:start position:0% +by itself and I work that one by itself +and what's left over by itself and uh + + align:start position:0% +and what's left over by itself and uh + + + align:start position:0% +and what's left over by itself and uh +that's how I can find an overall + + align:start position:0% +that's how I can find an overall + + + align:start position:0% +that's how I can find an overall +match the second case is that there + + align:start position:0% +match the second case is that there + + + align:start position:0% +match the second case is that there +isn't any set of girls which are + + align:start position:0% +isn't any set of girls which are + + + align:start position:0% +isn't any set of girls which are +compatible with uh exactly the same + + align:start position:0% +compatible with uh exactly the same + + + align:start position:0% +compatible with uh exactly the same +number of boys well since holes + + align:start position:0% +number of boys well since holes + + + align:start position:0% +number of boys well since holes +condition holds that means that every + + align:start position:0% +condition holds that means that every + + + align:start position:0% +condition holds that means that every +set of girls actually has to be + + align:start position:0% +set of girls actually has to be + + + align:start position:0% +set of girls actually has to be +compatible with a larger set of boys + + align:start position:0% +compatible with a larger set of boys + + + align:start position:0% +compatible with a larger set of boys +than the number of girls that is for + + align:start position:0% +than the number of girls that is for + + + align:start position:0% +than the number of girls that is for +every uh set s the size of s is strictly + + align:start position:0% +every uh set s the size of s is strictly + + + align:start position:0% +every uh set s the size of s is strictly +less than the size of e of s for every + + align:start position:0% +less than the size of e of s for every + + + align:start position:0% +less than the size of e of s for every +non-empty and proper subset s well in + + align:start position:0% +non-empty and proper subset s well in + + + align:start position:0% +non-empty and proper subset s well in +that case actually finding a match is + + align:start position:0% +that case actually finding a match is + + + align:start position:0% +that case actually finding a match is +easy cuz now I've got slack what I can + + align:start position:0% +easy cuz now I've got slack what I can + + + align:start position:0% +easy cuz now I've got slack what I can +do is just pick an arbitrary girl call + + align:start position:0% +do is just pick an arbitrary girl call + + + align:start position:0% +do is just pick an arbitrary girl call +her G and she's got to be compatible + + align:start position:0% +her G and she's got to be compatible + + + align:start position:0% +her G and she's got to be compatible +with with at least one boy because + + align:start position:0% +with with at least one boy because + + + align:start position:0% +with with at least one boy because +there's no bottlenecks in fact in this + + align:start position:0% +there's no bottlenecks in fact in this + + + align:start position:0% +there's no bottlenecks in fact in this +case she'll actually be compatible with + + align:start position:0% +case she'll actually be compatible with + + + align:start position:0% +case she'll actually be compatible with +at least two boys but all we need is one + + align:start position:0% +at least two boys but all we need is one + + + align:start position:0% +at least two boys but all we need is one +boy since there's no bottlenecks if I + + align:start position:0% +boy since there's no bottlenecks if I + + + align:start position:0% +boy since there's no bottlenecks if I +pick a girl she's got to be compatible + + align:start position:0% +pick a girl she's got to be compatible + + + align:start position:0% +pick a girl she's got to be compatible +with some boy and I'm just going to + + align:start position:0% +with some boy and I'm just going to + + + align:start position:0% +with some boy and I'm just going to +arbitrarily match her with that boy + + align:start position:0% +arbitrarily match her with that boy + + + align:start position:0% +arbitrarily match her with that boy +match G with B now the consequence of + + align:start position:0% +match G with B now the consequence of + + + align:start position:0% +match G with B now the consequence of +that is that if I now remove G and B + + align:start position:0% +that is that if I now remove G and B + + + align:start position:0% +that is that if I now remove G and B +from the graph I am left with a graph in + + align:start position:0% +from the graph I am left with a graph in + + + align:start position:0% +from the graph I am left with a graph in +which uh at worst I've Shrunk The set e + + align:start position:0% +which uh at worst I've Shrunk The set e + + + align:start position:0% +which uh at worst I've Shrunk The set e +of s by that girl that I matched with B + + align:start position:0% +of s by that girl that I matched with B + + + align:start position:0% +of s by that girl that I matched with B +which means that e of s which used to be + + align:start position:0% +which means that e of s which used to be + + + align:start position:0% +which means that e of s which used to be +strictly greater than S has gone down by + + align:start position:0% +strictly greater than S has gone down by + + + align:start position:0% +strictly greater than S has gone down by +at most one it's still greater than or + + align:start position:0% +at most one it's still greater than or + + + align:start position:0% +at most one it's still greater than or +equal to e of s so I'm left that in the + + align:start position:0% +equal to e of s so I'm left that in the + + + align:start position:0% +equal to e of s so I'm left that in the +graph after I've removed this G with + + align:start position:0% +graph after I've removed this G with + + + align:start position:0% +graph after I've removed this G with +paired with an arbitrary B that she's + + align:start position:0% +paired with an arbitrary B that she's + + + align:start position:0% +paired with an arbitrary B that she's +compatible with I'm left with a graph + + align:start position:0% +compatible with I'm left with a graph + + + align:start position:0% +compatible with I'm left with a graph +that satisfies Hall's condition and it + + align:start position:0% +that satisfies Hall's condition and it + + + align:start position:0% +that satisfies Hall's condition and it +that has one fewer uh boy vert girl + + align:start position:0% +that has one fewer uh boy vert girl + + + align:start position:0% +that has one fewer uh boy vert girl +vertex and so it has no bottlenecks and + + align:start position:0% +vertex and so it has no bottlenecks and + + + align:start position:0% +vertex and so it has no bottlenecks and +therefore uh it has a + + align:start position:0% +therefore uh it has a + + + align:start position:0% +therefore uh it has a +match and that match in the subgraph + + align:start position:0% +match and that match in the subgraph + + + align:start position:0% +match and that match in the subgraph +where I've taken out G and B when I put + + align:start position:0% +where I've taken out G and B when I put + + + align:start position:0% +where I've taken out G and B when I put +back the match when I add the part of G + + align:start position:0% +back the match when I add the part of G + + + align:start position:0% +back the match when I add the part of G +matching with B it's a match for the + + align:start position:0% +matching with B it's a match for the + + + align:start position:0% +matching with B it's a match for the +whole graph and that's how I get it that + + align:start position:0% +whole graph and that's how I get it that + + + align:start position:0% +whole graph and that's how I get it that +completes the proof of Halls theorem \ No newline at end of file diff --git a/iKLvCuFD1MA.txt b/iKLvCuFD1MA.txt new file mode 100644 index 0000000000000000000000000000000000000000..75e3a6ed191ed9cc38f474a61933a47793e19905 --- /dev/null +++ b/iKLvCuFD1MA.txt @@ -0,0 +1,4048 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: All right, well, +good afternoon and welcome back. + +We have an exciting fun-filled +program for you this afternoon. + +I'm David Gifford. + +I'm delighted to +be back with you + +again, here in computational +systems biology. + +Today we're going to talk +about chromatin structure + +and how we can analyze it. + +And to give you the narrative +arc for our discussion today, + +we're first going to +begin with looking + +at computational methods that +we can break the, quote unquote + +code, that describes +the epigenome. + +Now, epigenetic state is +extraordinarily important + +and one way you +can visualize this + +is that the genome is +like a hotel filled + +with lots of different rooms. + +And a lot of the doors are +locked and some of the doors + +are unlocked. + +And only in the doors +that we can go into, + +where the genome is +open and accessible + +can there actually be work +done, regulation performed + +and transcripts +and proteins made. + +So we're going to talk about +how to actually analyze + +epigenetic state. + +And then we're going +to talk about how + +to use epigenetic +information to understand + +the entire regulatory +occupancy of the genome. + +We've already talked about +ChIP-seq and the idea + +that we can understand where +individual regulators sit + +on the genome, and how they +regulate proximal genes. + +We're now going to see if we +can learn more about the genome. + +How it's state-- whether +it's open or closed. + +Is it self-regulated? + +And answer a puzzle. + +The puzzle is, if there +are hundreds of thousands + +of possible binary +locations that + +are equally good +for a regulator, + +why are only tens of +thousands occupied? + +And how are those sites picked? + +Because that level of regulation +is extraordinarily important + +to establish a basal +level of what genes + +are accessible and operating. + +And finally, we're going to +talk about how we can map, + +which regulatory +regions in the genome + +are affecting which genes. + +It turns out that about +1/3 of the regulatory sites + +in the genome skip over a +gene that's closest to them + +to regulate a gene +that's farther away. + +This is a million genomes. + +And so given that +rough approximation, + +how is it that we +can make connections + +between regulatory sites and +the genes that they control? + +Now, in computational +systems biology, + +we always talk a +lot about biology, + +but we also need to reflect +upon the computational methods + +that we're bringing to +bear on these questions. + +And so, today, we're +going to be talking + +about three different methods. + +We'll talk about dynamic +Bayesian networks as a way + +to approach, understanding +the histone code. + +We'll talk about how to +classify factor binding, + +using log likelihood ratios. + +And finally, we'll +turn to our friend, + +the hypergeometric +distribution to analyze + +which locations +in the genome are + +interacting with one another. + +So let's begin with +establishing a vocabulary. + +I'm sure some of you +have seen this before. + +This is the way +that chromatin can + +be thought of being organized +at different levels. + +There's the primary +DNA sequence, + +which can include +methylated CPGs. + +That's cysteine, +phosphate, guanine. + +And the nice thing about +that is that it's symmetrical + +so that when you have a CPG, +a methyltransferase during DNA + +replication can copy +that methy mark over. + +So it's a mark that's heritable. + +The next level down +are histone tails. + +On the amino terminus +of histones H3 and H4, + +different chemical +modifications can be made, + +and they serve as +sign posts, as we'll + +see, to give us +clues about what's + +going on in the genome in +that proximal location. + +The next level down +is, whether or not + +the chromatin is +compacted or not. + +Whether it's open or closed. + +And that relates +to whether or not + +DNA binding proteins are +actually on the genome. + +And finally, certain +domains of the genome + +can be associated with +the nuclear lamina. + +And so they're different levels +of organization of chromatin. + +And we'll be exploring +all of these today. + +So the cartoon +version of the way + +that the genome is +organized is that at the top + +we have a transcribed gene. + +And you can see that +there's an enhancer that + +is interacting with the RNA +polymerase II start site. + +And you can see +varied histone marks + +that are associated with +this activated gene. + +There are also marks +that are associated + +with that active enhancer. + +Down below, you see +an inactive gene. + +And you can see that there's +a boundary element that's + +bound by CTCF, which, +one of its function + +is to serve as a genomic +insulator, which insulates + +the effect of the enhancer +above from the gene below. + +So through careful biochemical +analysis over the years, + +these different marks have been +analyzed and characterized. + +And a general paradigm +for understanding + +how the marks transition +as genes are activated + +is shown here. + +So genes that are +fairly active and cycle + +between active and +inactive states typically + +have a high CPG content +in their promoters. + +And transition is +shown on the left. + +Where in the repressed +state on the bottom, + +they're marked by +H3K27 trimethyl marks. + +When they're poised, they have +both H3K4 trimethyl and H3K27 + +trimethyl. + +And when they're active, they +only have H3K4 trimethyl. + +And on the right hand side are +genes that are less active. + +So in their completely shut down +state, they may have no marks, + +but the DNA is +methylated, silencing + +that region of the genome. + +And other marks then, +culminating in H3K4 trimethyl + +once again when they +become active at the top. + +So I'm summarizing +for you here, decades + +of research in histone marks. + +And it has been +summarized in figures + +like this, where you can +look at different classes + +of genetic elements-- whether +they be promoters in front + +of genes, gene bodies +themselves, enhancers, + +or the large scale +repression of the genome-- + +and you can look +at the associated + +marks with those +characteristic elements. + +OK, so, how can we +learn this de novo? + +That is, you could +memorize, and of course it's + +important to +understand, for example, + +if you want to look +for active enhancers + +in the genome, that +looking for things + +like H3K4 monomethyl and H3K7 +27 acetyl marks together, + +would give you a good clue +where the enhancers are + +in the genome that are active. + +But if we want to +learn all this de novo, + +without having to memorize it +or rely upon the literature, + +the great thing is that there's +a lot of data out there now + +that characterizes, or profiles +all these marks, genome-wide, + +in variety of cellular states. + +And there's the epigenome +roadmap initiative + +to look at this in hundreds +of different cell types. + +So, what is the histone code? + +That is, how can we +unravel the different marks + +present in the genome and +understand what they mean? + +Because the genome doesn't come +ready-made with those little + +cute labels that we had on +it-- enhancer, gene body, + +and so forth. + +So somehow, if we +want to understand + +the grammar of the +genome and its function, + +we're going to need to be +able to annotate it, hopefully + +with computational help. + +So here's a picture of +what typical data looks + +like along the genome. + +So, obviously you can't +read any of the legends + +on the left-hand side. + +If you want to look +at the slides that + +are posted on Stellar, you +can see the actual marks. + +But the reason I posted +this is because you + +can see the little pink +thing at the top-- that's + +where the RNA transcript has +been mapped to the genome. + +The actual annotated +genes are above. + +And then down below you +can see a whole collection + +of histone marks and other +kinds of chromatin information + +that have been +mapped to the genome + +and spatially +create patterns that + +are suggestive of the function +of the genomic elements, + +if they're properly interpreted. + +And below, you see in blue, +the binding of different TFs, + +as determined by ChIP-seq. + +So, what we would +like to do then, + +is to take this +kind of information + +and automatically learn, +or automatically annotate + +the genome as to its +functional elements. + +Let me stop here and +ask, how many people + +have seen histone mark +information before? + +OK. + +And how many people have +used it in their research? + +Not too many-- a couple people? + +OK. + +So it's getting +quite easy to collect + +and there are a couple of ways +of analyzing this kind of data, + +genome-wide. + +One way is that we could +run a hidden Markov + +model over these data +and predict states + +at regular intervals. + +For example, every 200 +bases down the genome, + +and see how the HMM transition +from state to state and let + +the state suggest what the +underlying genome elements + +that we're doing. + +Another way is to use a +dynamic Bayesian network. + +So a dynamic Bayesian network +is simply a Bayesian network. + +We've talked about those before. + +And it models data +sampled along the genome. + +And so it's a directed +acyclic graph. + +There are tools out +there that allow + +us to learn these +models directly. + +And it allows us, as we'll +see, to analyze the genome + +at high resolution, and +to handle missing data. + +So we'll be talking +about Segway, + +which is a particular +dynamic Bayesian network that + +takes the kind of data +we saw on the slide + +before and essentially parses +it into labels that allow us + +to assign function to +different genomic elements. + +And it does this in +an unsupervised way. + +What I mean by that is +that it is automatically + +learning the states, +and then afterwards we + +can look at the states and +assign meaning to them. + +So here is the dynamic Bayesian +network that Segway uses. + +And let me explain +this somewhat scary + +looking diagram of lots of +little boxes and pointers + +to you. + +The genome is described +through the variables + +on the bottom-- the +observation variables, + +going from left to +right, where each base is + +a separate observation +variable which consists + +of the level of a +particular histone mark + +at a particular based position +as described by mapped + +reads to that location. + +The little square +box-- the little boxes + +that says "x" on it with the +other small print you can't + +read-- is simply an +indicator, whether or not + +the data is present. + +If the data is absent, we +don't try and model it. + +If that box contains a zero, +we don't model the data. + +If the box is one, then we +attempt to model the data. + +And the most important part of +the dynamic Bayesian network + +is the q box above, where +those are the states. + +And each state describes an +ensemble of different histone + +marks that are output. + +And so the key thing +is that for each state + +we learn what marks +it's outputting. + +And the model learns +this automatically + +through a learning phase. + +The boxes above +simply are a counter. + +And the counter allows us +to define maximum lengths + +for particular states, so +states don't run on forever. + +So unlike a hidden +Markov model that + +doesn't have that +kind of control, + +we can adjust how long we +want the states to last. + +So this model, if you +turned it 90 degrees + +and rotated it clockwise, +would be more familiar to you + +because all the arrows +would be flowing + +from the top of the screen down. + +There are no cycles in this +directed acyclic graph. + +And therefore, it can be +probabilistically viewed + +and learned in +the same framework + +that we learn a +Bayesian network. + +In fact, it is a +Bayesian network. + +The reason it's +called dynamic is + +because we are learning +temporal information, + +or in this case, +spatial information + +with these different +observations + +along the bottom of the model. + +Now before I go on, +perhaps somebody + +could ask me a question +about the details + +of these dynamic +Bayesian networks, + +because the ability to +automatically assign labels + +to genome function, given +the histone marks is really + +a key thing that's gone on +the last couple of years. + +Yes? + +AUDIENCE: Could you +re-explain that-- + +what the labeled-- the second +[INAUDIBLE] was all about? + +PROFESSOR: Sure. + +So the Q label is right +here, these labels. + +And each of these +Q labels defines + +one of a number of states. + +For example, 24 +different states. + +In a given state, describes +the expected output + +in terms of what histone marks +are present in that state. + +So it's going to +describe the means of all + +those different histone marks. + +24 different means, +let's say, of the marks + +it's going to output. + +And the job of fitting the model +is picking the right states, + +or a set of 24 +states, each of which + +is most descriptive of its +particular subset of chromatin + +marks. + +And then defining how we +transition between states. + +So we not only need to +define what a state means + +in terms of the marks +that it outputs, but also + +when we transition from +one state to another. + +Does that make sense to you? + +AUDIENCE: So I know it +states the information that + +tells at each of the Q boxes. + +Is that a series +of probabilities? + +Or is it something else? + +PROFESSOR: It's actually +a discrete number, right. + +So it actually is a +single-- there's only + +a single state in each Q box. + +So it might be a +number between 1 and 24 + +that we're going to learn. + +And based upon +that number, we're + +going to have a +description of the marks + +that we would expect to +see at the observation + +at that particular +genomic location. + +And so our job here is to +learn those 24 different states + +and what they output +in the training phase, + +and then once we've +trained the model, + +we can go back and look +at other held out data, + +and then we can +decode the genome. + +Because we know what +the states are, and we + +know what they are +supposed to be producing, + +we can use a Verterbi decoder +and go back and-- as we + +did with the HMM and we +learned the HMM-- go back + +and read off on the +histone mark sequence + +and figure out what +their relative states are + +for each base position +of the genome. + +Is that helpful? + +Yes? + +Any other questions about +dynamic Bayesian networks? + +Yes? + +AUDIENCE: How do you choose +the number of states? + +PROFESSOR: That's a +very good question. + +How do you choose +the number of states? + +Well, if you choose +too many states, + +they obviously don't +really become descriptive + +and you can become +over fit and then + +can start fitting +noise to your model. + +And if you choose too few +states, what will happen + +is, that states can +get collapsed together + +and they won't be +adequately descriptive. + +The answer is, it's more +or less trial and error. + +There really isn't +a principled way + +to choose the right +number of states + +in this particular context. + +Now, you could do-- + +AUDIENCE: What's +the trial, then? + +You run it and you +get a set of things, + +and what do you do +with those labels? + +PROFESSOR: What do +you do with labels? + +AUDIENCE: Yeah, how +do you evaluate it? + +PROFESSOR: You +typically, in both + +of these cases-- both in the +case of chrome HMM and this-- + +you rely upon the +previous literature. + +And we saw on that +slide earlier, + +what marks are associated +with what kinds of features. + +So you use the prior +literature and you + +use what the states are telling +you they're describing to try + +and associate those +states with what's + +known about genome function. + +All right, yes? + +AUDIENCE: Where does that +information concerning + +the distance between +states go again? + +Like, the counter? + +Like, how does that +control how long + +the states go on +and whether or not-- + +PROFESSOR: What happens is that +the counter at the top, the C + +variables, influence the J +variables you can see there. + +When the J variable +terms to a 1, + +it forces the state transition. + +So the counters count +down and can then + +force a state +transition which will + +cause the Q variable to change. + +It's sort of a-- that particular +formulation of this model + +is a bit of a, sort +of Rube Goldberg kind + +of hackish kind of thing. + +I think to make it get +out of particular states. + +But it works, as we'll +see in just a moment. + +OK. + +So here's an example +of it operating. + +And you can see the different +states on the y-axis here. + +You can see the different +state transitions + +as we go down the genome. + +And you can see the +annotations that it's + +outputting, corresponding +to the histone marks. + +And so what this +is doing is it's + +decoding for us what it thinks +is going on in the genome, + +solely with reference +to the histone marks, + +without reference to primary +sequence or anything else. + +And this kind of +decoding is most useful + +when we want to discover things +like regulatory elements. + +When we want to look for H3K4 +mono or dimethyl, and H3K27 + +acetyl for example, and identify +those regions of the genome + +that we think are +active enhancers. + +OK. + +OK. + +So, any questions at all about +histone marks and decoding? + +Do you get the +general idea that you + +can assay these histone +marks through ChIP-seq using + +antibodies that are specific +to a particular mark. + +Pull down the histones that +are associated with DNA + +with that mark and map +them to the genome. + +So we get one track for +each ChIP-seq experiment. + +We can profile all the marks +that we think are relevant, + +and then we can look at +what those parks imply + +about both the static +structure of our genome, + +and also how it's being +used as cells differentiate + +or in different +environmental conditions. + +OK. + +OK. + +So, let's go on, then, +to the next step, which + +is that if we understand the +sort of epigenetics state, + +how is that established and +how is the opening of chromatin + +regulated and how is it that +factors find particular places + +in the genome to bind? + +So, the puzzle I talked +to you about earlier + +was that there are +hundreds of thousands + +of particular motifs +in the genome, + +but a very small +number are actually + +bound by regulatory factors. + +And you might think +that the difference + +is that the ones that are bound +have different DNA sequences. + +But in fact, on the +right-hand side, what we see + +is that identical DNA sequences +are bound differentially + +in two different conditions. + +Shown there are +sites that are only + +bound, for example, +in endodermal tissues + +or in ES cells. + +So it isn't the sequence +that's controlling + +the specificity of the +binding, it's something else. + +And we'd like to figure out +what that something else is. + +We'd like to understand +the rules that + +govern where those factors +are binding in the genome. + +So a set of factors are +known that bind to the genome + +and open it. + +They're called pioneer factors. + +There are some well known +pioneer factors like FoxA + +and some of the iPS +reprogramming factors. + +And the idea is that +they're able to bind + +to closed chromatin +and to open it up + +to provide accessibility +to other factors. + +So what we would +like to do, is to see + +if there's a way that we +could, both understand + +how to discover those +factors automatically, + +using a computational +method, and secondarily, + +understand where factors are +binding in a single experiment + +across the genome. + +So the results I'm going to +show you can be summarized here. + +I'm going to show +you a method called + +PIQ that can predict where +TFs bind from DNase-seq data + +that I'll describe in a moment. + +We'll identify pioneer factors. + +We'll show that certain of these +pioneer factors are directional + +and only operate in +one way on the genome. + +And finally, that the +opening of the genome + +allow subtler factors to come +in and to bind to the genome. + +So let's begin with +what DNase-seq data is, + +and how we can use +it to predict where + +TFs are binding to the genome. + +So DNase-seq is a +methodology for exploring + +what parts of the +genome are open. + +So here's the idea. + +You take your cell +and you expose it, + +once you've isolated the +chromatin to DNase-1 which + +will cut or nick +DNA at locations + +where the DNA is open. + +You then can collect the +DNA, size separate it + +and sequence it. + +And thus, you're +going to have more + +reads where the +DNA has been open, + +and less reads were it's +protected by proteins. + +So the cartoon below +gives you an idea + +that, where there are +histones-- each histone + +has about 147 bases of +DNA wrapped around it. + +Or where there are other +proteins hiding the DNA, + +you're going to cast +shadows on this. + +So we're going to be looking +at the shadows and also + +the accessible parts, +by looking directly + +at the DNase-seq reads. + +So if we sequence +deeply enough we + +can understand that +each binding protein has + +its own particular +profile of protection. + +So if you look at these +different proteins, + +they cast particular +shadows on the genome. + +I'm showing here a window +that's 400 base pairs wide. + +This is the average of thousands +of different binding instances. + +So this is not one binding +instance on the top row. + +You can see how CTCF +and other factors + +have particular shadows +they cast or profiles. + +Yes? + +AUDIENCE: How do you know +which factor was at which site? + +[INAUDIBLE]. + +PROFESSOR: How do we know +which factor is at which site? + +By the motifs that +are under the site. + +And what's +interesting about CTCF + +is that you can actually see +how it phase the nucleosomes. + +You can see the, sort of, +periodic pattern in CTCF. + +And those dips are where +the nucleosomes are. + +There's a lot you can +tell from these patterns + +about the underlying molecular +mechanism of what's going on. + +Now, you can see at the very +bottom, the aggregate CTCF + +profile. + +And if all the CTCF +bindings looked like that, + +it'd be really easy. + +But above it, as I've shown +you what an individual CTCF + +site looks like, you can +see how sparse it is. + +We just don't get +enough re-density to be + +able to recover a beautiful +protection profile like that. + +So we're always working +against a lot of noise + +in this kind of +biological environment. + +And so our +computational technique + +will need to come up +with an adequate model + +to overcome that noise. + +But if we can, right, +the great promise + +is that with a single +experiment we'll + +be able to identify where all +these different factors are + +binding to the genome +from one set of data. + +So, just reiterating now, +if you think about the input + +to this algorithm-- we're +going to have three things + +that we input to the algorithm. + +We input the original +genome sequence. + +We input the motifs +of the factors + +that we care about, that +we think are interesting. + +And we input the +DNase-seq data that + +has been aligned to the genome. + +So those are the three inputs. + +And the output of +the algorithm is + +going to be the predictions +of which motifs are occupied + +by the factors, +probabilistically. + +And in order to do +that, for each protein + +we need to learn its +protection profile. + +And we need to +score that profile + +against each +instance of the motif + +to see whether or not we +think the protein is actually + +sitting at that +location in the genome. + +Any questions at all about that? + +No? + +OK. + +Don't hesitate to stop me. + +So the design goals for this +particular computational + +algorithm, as I said earlier, +is resistance to low coverage + +and lots of noise. + +To be able to handle +multiple experiment once, + +it has to work on the +entire mammalian genome. + +It has to have high +spatial accuracy + +and it has to have good +behavior in bad cases. + +So in order to model the +underlying re-distribution + +of the genome, what +we're going to do + +is something that +is in principle + +quite straightforward. + +Which is that we're going to +model all accounts that we + +see in the genome by a +Poisson distribution. + +So in each base of +the genome, the counts + +that we see there in +the DNase-seq data + +are modeled by a Poisson. + +And this is assuming that +there's no protein bound there. + +So what we're trying to do +is to model the background + +distribution of counts +without any kind of binding. + +And the log rate +of that Poisson is + +going to be taken from +a multivariate normal. + +And the particular structure +of that multivariate normal + +provides a lot of smoothing. + +So we can learn from +that multivariate normal + +how to fill in +missing information. + +It's very important +to build strength + +from neighboring bases. + +So, even though we may not +have lots of information + +for this base, if +we have information + +for all the bases around us, +we can use that information + +to build strength to estimate +what we should see at this base + +if it's not occupied. + +So the details of how we +learn the mean and the sigma + +matrix you see up +there for estimating + +the multivariate normal +are outside the scope + +of what I'm going +to talk about today. + +But suffice to say, they +can be effectively learned. + +And the second thing we need +to learn are these profiles. + +And so each protein is +going to have a profile. + +Here shown 400 bases wide. + +And it describes how that +protein, so to speak, + +casts a shadow on the genome. + +And we judge the significance +of these profiles-- + +and remember that +one of my points + +was I wanted this to be robust. + +So I will not make calls for +proteins where I cannot get + +a robust profile that is +significant above background. + +And I also exclude the +middle region of the profile + +because it's been shown that +the actual cutting enzymes are + +sequence specific +to some extent. + +The DNase-1 cutting enzyme. + +And so we don't +simply want to be + +but picking up sequence +bias in our profile. + +So we learn these +profiles that describe + +for each particular +motif-- and typically we + +can take in hundreds of motifs, +over 500 motifs at once-- + +for each motif, what its +protection looks like. + +So what we then have-- we're +going to learn this, actually, + +in an iterative process, but +what we're going to have is-- + +now we have a model of what the +unoccupied genome looks like. + +And we have a model of the +reads that a particular protein + +at a motif location +is going to produce. + +And we can put those two +things together and the way + +that we do that is that we +have a binding variable. + +Showing there is delta. + +And we can either add or +not add the binding profile + +of a particular protein in +a location in the genome. + +And that will change the +expected number of counts + +that we see. + +So the key part of this is that +we use a likelihood ratio shown + +as the second probability. + +It's not really a +probability, it's + +a ratio, which is the +probability of a count, given + +that a protein j is +binding at that location, + +versus the probability of the +counts, were it not binding. + +And that quantity +is key because it's + +going to be-- once +we log transform it, + +will be a key component +of our test statistic + +to figure out whether +or not a protein's + +binding at a +particular location. + +And so the way that we go about +that is it we log that ratio + +and we add it to some other +prior information that gives us + +an overall measure +for whether or not + +the protein is binding +at a particular location. + +And then we can rank +these for all the motifs + +for that particular +protein in the genome. + +And then we can make +calls using a null set. + +So we could look in the +genome for locations + +that we know are not occupied, +compute a distribution + +of that statistic, +and then we can say, + +for what values of this +statistic that we observe, + +at the actual motif sites, +is it so unlikely that this + +would occur at random. + +At some desired p +value by looking + +at the area in the +tail of the null set. + +So, just summarizing, we +learn a background model + +of the genome, which +is a Poisson that + +takes log rates from +a multivariate normal. + +We learn patterns, or +profiles of protection, + +or the production of +reads for each motif. + +And at each motif location, +we ask the question + +whether or not, it's +likely that the protein + +was there and actually caused +the reads that we're seeing, + +using a log likelihood ratio. + +So what we're +integrating together, + +when we take all +these things, is + +that we're taking our +original DNA seq-reads, + +we're taking our TF-specific +specific binding profiles. + +We can build strength across +experiments for the background + +model and we can also learn, +to what extent, the strength + +of binding is influenced by +the match of the position-- + +a specific weight matrix-- +to a particular location + +in the genome. + +And then we can +produce binding calls. + +And when we do so, +it works quite well. + +So here you see three +different mouse ESO factors. + +And the area under +this receiver operating + +curve-- we've talked +about this before. + +Remember a receiver +operating characteristic + +curve-- has false +positives increasing + +on the x-axis and true positives +increasing on the y-axis. + +And if we had a perfect method, +the area under that curve + +would be 1.0. + +And so for this method, +the area under the ROC + +curve for these three +factors, using ChIP-seq data, + +is the absolute gold +standard, is over 0.9. + +And you might say, +well that's great, + +but how well does +it work in general? + +I mean, for example, +the On-code project + +has used hundreds and hundreds +of ChIP-seq experiments + +to profile where +factors are binding + +in different cellular states. + +If you take the DNase-seq data +from those matched cell types + +and you ask, can you reproduce +the ChIP-seq seq data? + +The answer is, a lot +of the time we can, + +using this kind of methodology. + +And that is, the +AUC mean is 0.93 + +compared to 313 different +ChIP-seq experiments. + +So this methodology of +looking at open chromatin + +allows us to identify where +lots of different factors + +bind to the genome. + +And about 75 different +factors are strongly + +detectable using +this methodology. + +So it's detectable if +it has a strong motif, + +if it binds in +DNase-accessible regions + +and has strong +DNA-binding affinity. + +So I tell you this +just so you know + +that there are +new methods coming + +that allow us to take +a single experiment + +and analyze it and determine +where a large number of factors + +bind from that single +experimental data set. + +Now, a second question +we wanted to answer + +was, how is it that chrome, +opening and closing is + +controlled? + +And since we had a direct read +out of what chromatin is open, + +because reads are +being produced there, + +we could look in a +experimental system + +where we measured +chromatin accessibility + +through developmental time. + +And the idea was that as we +measured this accessibility, + +we could look at the +places that changed + +and determine what underlying +motifs were present that + +perhaps were causing the +genome to undergo this opening + +process. + +So we developed an +underlying theory + +that pioneer factors would bind +to closed chromatin as shown + +in the middle panel +and open it up, + +and that we could observe those +by looking at the differential + +accessibility of the genome +at two different time + +points that were related. + +And we couldn't observe pioneers +they didn't open up chromatin. + +And for non-pioneers-- +obviously the left-hand panel-- + +they would not, in +our design here, + +lead to increased accessibility. + +So we then looked at designing +computational indices that + +measured the-- +oh, question, yes? + +AUDIENCE: When you +say pioneer factors, + +are you looking at what proteins +are pioneer factors, or are you + +looking at what sequences they +bind to that are [INAUDIBLE]. + +PROFESSOR: So the +question is, are we + +looking at what +proteins are factors, + +or are we looking at +what sequence, right? + +What we're doing is, +we're making an assumption + +that the underlying sequence +denotes one or more proteins + +and thus, we are +hypothesizing, there's + +the proteins that are actually +binding to the sequence, that's + +causing that. + +And then later on, we'll go back +and test that experimentally, + +as you'll see in a second. + +OK? + +So here there are three +different metrics, + +which is the dynamic opening +of chromatin from one time + +point to the next, the +static openness of chromatin + +around a particular factor, +and a social index showing + +how many other factors +are around where + +a particular factor binds. + +And you can see that these +things are distributed in a way + +that certain of the factors have +a very high index in multiple + +of these scores. + +And thus, we were +able to classify + +a certain set of factors +as what we classified + +as computational pioneers, +that would open up the genome. + +Now, in any kind of +computational work, + +we're actually looking +at correlative analysis, + +which is never causal. + +Right. + +So we have to go back and we +have to test whether or not + +our computational +predictions are correct. + +So in order to do +that, we built a test + +construct where we +could put the pioneers + +in on the left-hand side +and ask, whether or not + +the pioneer would +open up chromatin + +and enable the expression +of a GFP marker. + +And the red bars +show the factors + +that we thought were pioneers. + +And as you can see, in +this case, all but one + +of the predictive pioneers +produces GFP activity. + +And this construct was +designed in an interesting way. + +We had to design it so that +the pioneers themselves + +were not simply activators. + +And so it was upstream of +another activator, which + +is a retinoic acid +receptor site. + +And so in the absence of +retinoic acid receptor, + +we had to ensure that when +we turned on the pioneer, + +GFP was not turned on. + +It was only with the +addition of the pioneer + +to open the chromatin +and the activator + +that we actually +got GFP expression. + +OK. + +So, through this +methodology we discovered + +about 120 different motifs +corresponding to proteins + +that we found computationally +open-- chromatin out. + +Yes? + +AUDIENCE: [INAUDIBLE] +concentrations + +of different pioneer +factors are different, + +wouldn't that show up +differentially [INAUDIBLE]? + +PROFESSOR: The question +is, if the concentration + +of different pioneer +factors was different, + +wouldn't that show +up differentially? + +And that's precisely, we +think how chromatin structures + +are regulated. + +That we think that the +concentration, or presence + +of different pioneer factors, +is regulating the openness + +or closeness of different +parts of the genome, + +based upon where their +motifs are occurring. + +Is that, in part, +answering your question? + +AUDIENCE: Yes, but, +if a concentration + +of a particular +pioneer factor is low, + +do they necessarily have lesser +binding sites on the genome? + +PROFESSOR: So you're +asking, how is + +the concentration +of a pioneer factor + +related to its ability +to open chromatin + +and whether or not a +higher dosage would + +open more chromatin? + +AUDIENCE: Yes. + +PROFESSOR: I don't have a +good answer to that question. + +Those experiments +haven't been done. + +However, one thing you may have +noticed about these profiles-- + +remember these are the same +profiles that we talked + +about earlier of DNase-1 +read reproduction + +around a particular factor. + +And what you might notice is +that some of these profiles + +are asymmetric. + +And that they appear to be +producing more region one + +direction than the +other direction. + +And so this is all +computational analysis, right. + +But when you see +something like that you + +say, well gee, why +is that going on? + +Why is it that for NRF-1 the +left-hand side has a lot more + +reads than the right hand side. + +Now, of course, the only reason +that we can produce an oriented + +profile like that is that the +NRF-1 motif is not palindromic, + +right. + +We can actually orient +it in the genome + +and so we know that the +more reads, in this case, + +are coming from +the five prime end + +then from the three prime end. + +So what do you think +would cause that? + +Does anybody have a-- +when we first saw this, + +we didn't know what it was. + +But anybody have an idea +of what that could be? + +Oh, yes. + +AUDIENCE: It's the remodelers +that these transcription + +factors are calling in tend to +open the chromatin more on one + +side of the motif +than the other. + +PROFESSOR: Right, +so if the remodelers + +are working in some sort +of directional way, right. + +So that's what we thought. + +We didn't know whether +they were or not. + +And so we went back to our +assay and we tested the motifs, + +both in the forward and +the reverse direction. + +Right. + +To see whether or +not it mattered + +which way the motif +went into the construct, + +based upon selecting factors, +based upon a symmetry + +score that we computed for +their read profile, right? + +And what we found was that, in +fact, it was the case that when + +the motif was properly +oriented it would turn on GFP + +and was in the other +direction it would not. + +So it appeared, for the +factors that we tested, + +that they did have directional +chromatin opening properties. + +And so that's an +interesting concept + +that you actually +can have chromatin + +being opened in one direction +but not the other direction, + +because it admits +the idea of some sort + +of genomic parentheses, +where you could imagine + +part of the genome +being accessible where + +the other part is not. + +And overall this led us to +classifying protein factors + +that are operating in +genome accessibility + +into three classes. + +Here shown as two, where +we have pioneers which + +are the things that +open up the genome, + +and settlers that follow +behind and actually + +bind in the regions where +the chromatin is open. + +That is, it's much more likely +that those factors are going + +to bind where the doors +of the rooms are open, + +and the pioneers are +the proteins that + +come along and open the doors, +in particular, chromatin + +domains. + +And there were a couple of other +tests that we wanted to do. + +We wanted to test whether +or not we could knock out + +this pioneering activity by +taking a pioneer and just + +only including its +DNA-binding domain + +and knocking out the +rest of its domain + +which might be operative +in doing this chromatin + +remodeling. + +And then asked, +whether or not, when + +we expressed this sort +of poisoned pioneer, + +whether or not it would affect +the binding of nearby factors. + +And, in fact, when +you do express + +the sort of poison +pioneer, it does + +reduce the binding +of nearby factors. + +Here, we have a dominant +negative for NFYA + +and dominant negative for NRF1. + +It reduces the binding +of nearby factors. + +And finally, we wanted +to know, if we included + +a dominant negative for +the directional pioneer, + +if it actually +would preferentially + +affect the binding +of [INAUDIBLE] on one + +side of its binding +occurrences or the other side. + +And so we looked +at mix sites that + +were oriented with +respect to NFYA. + +And when we add +the NFYA, you can + +see that it actually-- the +dominant negative NFYA-- when + +the mix site is down of where +we think NFYA is opening up + +the chromatin, the binding +is substantially reduced. + +Whereas, when the +Myc site is not + +on the side where we think +that NFYA is opening, + +it doesn't really +have an effect. + +So this is further +confirmation of the idea + +that in vivo, these +factors are actually + +operating in a directional way. + +Now I tell you all +this because, you know, + +we do a lot of +computational analysis + +and it's important to +follow up and understand + +what the correlations tell us. + +So when you do +computational analysis + +and you see a very +interesting pattern, + +the thing to keep in mind +is, what kind of experiment + +can I design to +test whether or not + +my hypothesis is correct or not? + +We also did an analysis across +human and mouse data sets + +and found that +for a given motif, + +and thus, protein +family, it appeared + +that the chromatin +opening index was largely + +preserved, evolutionarily. + +So that there are +similar pioneers + +between human and mouse. + +Are there any questions +at all about the idea? + +So I told you, I mean, when you +go to cocktail party tonight, + +you say hey, you know, did +you know that DNase-seq + +is this really cool technique +that not only tells you + +whether or not chromatin is +open or not, but, you know, + +where factors bind? + +And some of those factors +open up the chromatin itself + +and, plus, get this, +some of the factors only + +do it in one direction, right. + +That'd be a good +conversation starter, right? + +That'd be the end of +the conversation, no. + +You get the idea, right. + +So are there any questions +about DNase-1 seq analysis? + +Yes? + +AUDIENCE: A little unrelated, +but I was just wondering-- + +in the literature where people +have identified factors that + +neither directly reprogram +between different cell types, + +or go through some sort of +[INAUDIBLE] intermediate-- + +PROFESSOR: Yes. + +AUDIENCE: There are a number +of transcription factors + +that have been +identified. [INAUDIBLE] + +but there are others. + +Do you often see, or always +see some of the pioneers + +that you've identified +in those cases. + +And then-- + +PROFESSOR: Yes. + +AUDIENCE: And then, +a follow-up question + +would be, do you think that if +you took some of the pioneers + +that you generated that +were not known before + +and expressed them +in cell types, + +that they would open +up the chromatin + +sufficiently to potentially +reprogram the mistakes? + +PROFESSOR: Right. + +So the question +was, is it the case + +that known +reprogramming factors, + +at times are powerful pioneers? + +The answer is yes. + +The second question was, +now that you have a broader + +repertoire of pioneer +factors, and you + +can identify what they're +doing, is a possible to, + +in a principled way, engineer +the opening of chromatin + +by perhaps expressing those +factors to see whether or not + +you could match a particular +desired epigenetic state, + +let's say? + +Our preliminary results are yes +on the second count as well. + +That there appear to +be pioneer factors that + +operate, sort of at a +basal level that keep, + +sort of, the sort of usual +rooms open in the genome. + +And then there are +factors that operate + +in a lineage-specific +specific way. + +And when we express +lineage-specific pioneer + +factors, they don't completely +mimic but largely mimic + +the chromatin state +that's present + +in the corresponding +lineage committed cells. + +And so we think that for +principal reprogramming + +of cells, the basal level +of establishing matched + +open states is going to be +an interesting and important + +avenue to explore. + +Does that answer your question? + +Yeah. + +OK. + +So, now we're going to +turn to another-- well let + +me just first summarise +what I just told you about, + +which is that we +can predict where + +TFs bind from DNase-seq data. + +We can identify these +pioneer factors. + +Some of them are directional. + +And other factors follow +these pioneers and bind + +sort of in their wake. + +In where they are actually +open up the chromatin. + +And returning to our +narrative arc for today, + +we've talked about the +idea of histone marks. + +We've talked about the +idea of chromatin openness + +and closeness. + +And now I'd like to talk about +the important question of how + +we can understand which +regulatory regions are + +regulating which genes. + +Now the traditional +way to approach this, + +is that if you have a regulatory +region, the thing that you do + +is you look for +the closest gene. + +And you go, aha, that's the one +that that regulatory region is + +controlling. + +This applies not only +for regulatory regions + +but for snips, right. + +If you find a snip +or a polymorphism + +you are likely to +assume that it's + +regulating the closest gene. + +It could have an effect +on the closest gene. + +But there are other ways of +approaching that question + +with molecular protocols. + +And drawing you once again +a cartoon of genome looping, + +you can see how an enhancer is +coming in contact with the Pol + +II holoenzyme apparatus. + +And this enhancer will +include regulators + +that will cause Pol II +to begin transcription. + +And if somehow we could +capture these complexes + +so that we could examine them +and figure out what bits of DNA + +are associated with +one another, we + +could map, directly, what +enhancers are controlling what + +genes, when they're +active in this form. + +So the essential idea of a +variety of different protocols, + +whether it be protocols +like high c or ChIA-PET + +that we're going to +talk about are the same. + +The difference is that +in the case of ChIA-PET, + +we're only going to look +at interactions that + +are defined by a +particular protein. + +So what we're going to do in +the slides I'm going to show you + +today, is we're +going to only look + +at interactions that are +mediated through RNA polymerase + +II. + +And those are particularly +interesting interactions + +as you can see, +because they involve + +actively transcribed genes. + +So if we could capture all +the RNA polymerase II mediated + +interactions, we'd +be in great shape. + +So, we have a lot of very +talented biologists here. + +So would anybody like to make +a suggestion for a protocol + +for actually revealing +these interactions? + +Does anybody have any ideas +how you'd go about that? + +Or what enzyme +might be involved? + +Any ideas? + +Don't be bashful now. + +Yes. + +AUDIENCE: How about fixing +everything in place where it is + +and then getting +[INAUDIBLE] through DNA. + +PROFESSOR: OK. + +Fixing everything +where it is in place. + +That's good. + +So we might cross link this +whole thing, for example. + +OK. + +And then any other +ideas what we would do? + +That's done, this +protical-- yes. + +AUDIENCE: Well, [INAUDIBLE] that +you've going to be [INAUDIBLE]. + +And then digesting the +DNA that's coming out, + +and then that lingers +to the DNA that + +are closest together +in the sequence. + +PROFESSOR: OK. + +So I think what you're +suggesting goes something + +like this. + +All right. + +Which is, that imagine that +we cross link those complexes + +and we precipitate them. + +And then what we do is we, +in a very dilute solution, + +we ligate the DNA together. + +And so we get two kinds +of ligation products. + +On the left-hand side we +get self-ligation products + +where a DNA molecule +ligates to itself. + +And on the right-hand side we +get inner ligation products, + +where the piece of DNA +that the enhancer was on, + +ligates to the pieces of DNA +that the RNA polymerase was + +transcribing the gene on. + +And those inter-ligation +bits of DNA, + +the ones that are red and blue, +are really interesting, right. + +Because they contain both +the enhancer sequence + +and the promoter sequence. + +And all we need to do now is +to sequence those molecules + +from the ends and figure out +where they are in the genome. + +Yes? + +AUDIENCE: How much variation +would there be in the sequence? + +I guess I'm just wondering-- the +RNA polymerase is not static, + +is it? + +In terms of its interaction +with the intenser and the gene. + +I just don't know what +would be capturing in this-- + +PROFESSOR: Right. + +AUDIENCE: [INAUDIBLE] +doesn't just + +touch at the beginning +and then [INAUDIBLE]. + +PROFESSOR: Right. + +And I think that's a +very good question. + +And in fact, a PhD thesis was +just written on this topic. + +Which is, when you have +proteins that are moving down + +the genome, in +some sense, you're + +looking at a blurred picture. + +So how do you +de-blur the picture + +so that it's brought +sharply into focus? + +And so a compute is something +called a point spread function + +which describes how things are +spread out down the genome. + +And then you invert that to get +a more focused picture of where + +the protein is actually, +primarily located. + +But you're right. + +Things like RNA +polymerase II are not + +thought of as +point-binding proteins. + +They're actually proteins +in motion most time + +when they're doing their work. + +AUDIENCE: [INAUDIBLE] +that it's polymerizing, + +does that it mean that it's +still continually bound + +to the [INAUDIBLE]? + +PROFESSOR: No. + +Although, I don't +think we really + +understand all of the +details of that mechanism. + +But, suffice to say +that what I can do + +is I can start showing +you data and from the data + +we can try and +understand mechanism. + +These are all great +questions, right. + +Yes. + +AUDIENCE: When we did the +citations and ligation, + +you're going to get a lot +of random ligation, right? + +PROFESSOR: A lot +of random ligation? + +AUDIENCE: Yeah, between DNA +sequences that aren't aren't, I + +guess, as close? + +Or you shouldn't really be +ligating certain things? + +PROFESSOR: Well, this picture is +a little bit deceiving, right? + +Because there's actually another +complex just like the one + +at the top, right +to its left, right? + +And you could imagine those +things ligating together. + +And so now you're going to +get ligation products that + +are noise. + +They don't mean anything. + +AUDIENCE: Do you just +throw those out, I guess? + +PROFESSOR: Well, the problem is, +you don't know which ones are + +noise and which ones aren't. + +Right? + +Now, there are some clever +tricks you can play. + +One clever trick is +to change the protocol + +to do these kinds +of reactions, not + +in solution, but +in some sort of gel + +or other thing that +keeps the products apart. + +The other thing you +can do is estimate + +how bad the situation is. + +And how might you do that? + +What you do is, you +take one set of-- you + +take your original preparation +and you split it into two. + +OK. + +And you color this one red and +this one blue using linkers, + +right. + +And then you put them together +and you do this reaction. + +And then you ask, +how many molecules + +have the red and the +blue linkers on them. + +And then you know those are +bad ones because they actually + +came from different +complexes, right. + +And so by estimating the amount +of critical chimeric products + +you get, from that split and +then recombined approach, + +you can optimize the protocol to +reduce the chimeric production + +rate. + +Current chimeric production +rates are about 20%. + +Something of that order. + +OK. + +It used to be 50%, +that's really bad. + +OK. + +So you can try +and optimize that. + +Now, if the protocol +has these issues-- + +you have a moving protein +that was brought up here, + +right, that you're +trying to capture. + +You've got a lot of noise +coming from the background + +of these reactions, right. + +Why are we doing this? + +Well, it's the only +game in town right now. + +If you want to have +a mechanistic way + +of understanding what enhancers +are communicating with what + +genes, this and its +family-- I broadly + +call this a family +of protocols-- + +is really the only way to go. + +OK. + +The interesting thing +is that when you do, + +you get data like this. + +And so, what you're +looking at here + +is exactly the same +location in the genome. + +It's about 600,000 bases +across from left to right. + +OK. + +And at the very bottom, +you see the SOX2 gene. + +And you have three +different cellular states. + +The top state-- +our motor neurons + +have been programmed through +the ectopic expression + +of three transcription factors. + +The second set of +interactions are motor neurons + +that have been +produced by exposure + +to small molecules +over a 7-day period. + +And the bottom set +of interactions + +are from mouse ES cells +that are plueripotent. + +And what's interesting +is that you + +can see how-- I'm +going to point here. + +You can see here-- this is the +SOX2 gene down at the bottom. + +And you can see here-- +this regulatory region + +is interacting heavily with +the SOX2 gene at the ESL state. + +And above here, I have +put SOX2 ChIP-seq data. + +So you can actually see that +SOX2 is regulating itself. + +And up here, we have the +same SOX2 gene locus. + +And OLIG2 is a key regulator +of this motor neuron fate. + +And you can see that it +appears that OLIG2 is now + +regulating SOX2. + +And we don't have as complete +dependence upon the SOX2 locus + +as we had before. + +And up here in the induced +motor neuron state, + +LHX4 is one of the +reprogramming factors + +and you can see how it is +interacting with SOX2 here + +and over here. + +So what this methodology +allows us to do, + +is to tie these regulatory +regions to the genes + +that they are regulating, +albeit it with some issues. + +So, we'll talk about the +issues in just a second. + +Are there any questions at all +about the idea of capturing, + +in essence, the folding of the +genome with this methodology + +to link regulatory +regions to genes? + +Yes? + +AUDIENCE: I have a question. + +So in each of +those charts you've + +got parts describing regions +that are interacting. + +PROFESSOR: Yes. + +AUDIENCE: Is that correct? + +PROFESSOR: Yes. + +The little loops underneath +are the actual read pairs + +that came out of the sequencer. + +And the green dotted +lines are the interactions + +I'm suggesting are significant. + +So I'm showing you +the raw data and I'm + +showing you the hypothesized +or purported interactions + +with the green dotted lines. + +Right? + +Right? + +AUDIENCE: So how is you raw +sequencing then transformed + +into this set of interactions? + +PROFESSOR: How is the raw +sequencing data-- remember + +that what came out +of the protocol + +were molecules on the +right-hand side that + +had little bits of DNA from two +different places in the genome. + +AUDIENCE: I'm +sorry, I meant, how + +did you determine-- because +I'm assuming each of these arcs + +has to have a single base start +side and a single base end + +site. + +PROFESSOR: Correct. + +AUDIENCE: However, +your reads are + +going to span-- your +joined paired reads are + +going to span a number of bases. + +So you have a number +of bases coming + +from the red part +and a number of bases + +coming from the blue part. + +PROFESSOR: We've got +20, 20 something, yeah. + +AUDIENCE: How do you determine +which of these red bases + +and which of these blue +bases are your start + +and end points for +the [INAUDIBLE]. + +PROFESSOR: Well, you are +looking at a 600,000 base pair + +window of the +genome and we're not + +quite at the resolution +of 28 bases yet. + +AUDIENCE: OK. + +PROFESSOR: So, you know-- + +AUDIENCE: So this is not +necessarily single base pair + +resolution, but this +is a region resolution? + +Is that correct? + +PROFESSOR: Once +again, the question + +of how to improve the spatial +resolution of these results + +is a subject of active research. + +And once again, you +can deconvolve things + +like the shearing to +actually get things + +down to within, say, 10 to +100 base pairs resolution. + +AUDIENCE: OK. + +PROFESSOR: OK? + +AUDIENCE: Got it. + +PROFESSOR: But you can't +identify the exact motif + +that the things land on, right. + +They can get in the +ballpark, so to speak, right. + +You can figure out where +you need to look for motifs. + +And so one thing +that we and others do + +is look at these +regions and we ask + +what motifs are present +into these regions. + +Or if you have match DNase-seq +data, you can go back + +and you can say, aha, +I have DNase-seq data. + +I have this data and +I know that there's + +something going on at +that region of the genome. + +What proteins do I +think are sitting there, + +based upon the protection +profiles I see. + +Right. + +So you can take an +integrative approach + +where you use different +data types to begin + +to pick apart the +regulatory network. + +Where you see the connections +directly molecularly, + +and you see the +regulatory proteins + +that are binding +at those locations. + +OK? + +Was that helpful? + +Good. + +Good questions. + +Any other questions? + +Yes? + +AUDIENCE: Would you consider +Hi-C and 5C and all of those + +to be the same +family of technique? + +PROFESSOR: I would. + +They're all, sort of the same +family and they're improving. + +I'm about to tell you why +this doesn't work very well. + +But, that said, it's the +best thing we have going. + +Right. + +5C is not any to any. + +It's to one to any. + +This protocol, when you do +one experiment with this, + +it tells you all the interacting +regions in the genome. + +Right. + +I believe 5C-- help +me if I'm wrong. + +You pick one anchor +location and then + +you can tell all the +regions and genomes that + +are interacting with +that anchor location. + +AUDIENCE: Isn't that 3C? + +PROFESSOR: What? + +AUDIENCE: 3C's one to one. + +4C's one to any. + +AUDIENCE: And 5C is-- + +AUDIENCE: 5C's any to any. + +PROFESSOR: And 5C's any to any? + +OK. + +I stand correct. + +Thank you. + +Yeah. + +OK. + +You didn't critique +my bond type. + +See I was trying to +get you and you didn't. + +OK. + +And other questions about this? + +OK. + +What could go wrong? + +What could go wrong? + +Well, I can tell you +what will go wrong. + +What will go wrong is that it +has a low true positive rate. + +OK. + +And how can you tell that? + +You do the experiment +twice and you + +get thousands of interactions +from each experiment in exactly + +matched conditions and +there's a very small overlap + +between the conditions. + +Oops. + +So, that's a pretty +big oops, right? + +Because you would like it +to be the case that when + +you do an experiment multiple +times, you get the same answer. + +So let us just +suppose that you get + +10,000 interactions +in experiment one. + +10,000 interactions in +experiment two, but only + +2,000 of them are the same. + +What could possibly +be going wrong? + +Any ideas? + +If you're looking at the +data, what would you think? + +Well? + +Yeah? + +AUDIENCE: [INAUDIBLE] +could be really high, + +so you're just seeing +a couple of things + +that are above the background. + +And they don't necessarily-- + +PROFESSOR: Right. + +So is it maybe +that, you know, it's + +just tough to get +these interactions out. + +And so you got a lot +of background trash. + +And the things that +are significant + +are tough to pick out. + +Yeah? + +AUDIENCE: Maybe it's a real +biological noise issue? + +So rather than the technique, +actually any given time that + +the interactions as so diverse +that when you take the snap + +shot you can't-- + +PROFESSOR: I like +that explanation + +because it's very pleasing +and makes me feel good. + +And I would be hopeful +that that would be true + +that there's enough biological +noise that that's actually + +what I'm observing. + +It doesn't make me feel +too warm and fuzzy, + +but you know, I'd +go with that, right. + +The other thing you +might think is, gee, + +if we just sequenced +that library more, + +we'd get more interactions +out them, right? + +So you go off and you compute +the library complexity + +of your library and you go, +oops, that's not going to work. + +There just isn't enough +diversity in the library. + +Meaning that the underlying +biological protocol did not + +produce enough of those +interesting inner ligation + +events to allow you to reveal +more information about what's + +going on. + +OK. + +Now if I ask you to judge the +significance of an interaction + +pair here. + +Let's think about +this using what + +we know already +from the subject. + +OK. + +So I'm going to draw a picture. + +So I have my genome. + +And let's just say that I have +a location, CA and a location CB + +and I have a pile of ends that +wind up in those two locations. + +OK. + +And what I would like +to know is-- and I have, + +let me just see what +variable I used for this. + +And I have a certain number of +interactions between a and b. + +That is I have a certain +number of reads that + +cross between these two +locations in the genome. + +And I'd like to know whether +or not this number of reads + +is significant. + +OK. + +How could I estimate that? + +Any ideas? + +Oh, I'm also going +to tell you that n + +is the total number +of read ends observed. + +OK. + +Well, here is the idea. + +I've got n total +read ends, right? + +I've got ca read ends here. + +I've got cv read +ends here, and I + +have iab that are overlapping. + +So now, this is just our old +friend, the hypergeometric, + +right. + +We can ask what is the +probability of that happening + +at random? + +This many interactions or +fewer would happen at random. + +And if it's very +unlikely, we would + +reject the null hypothesis +and accept that there's really + +an interaction going on here. + +OK? + +So, just to be more +precise about that. + +This is what it looks like. + +You've seen this before. + +That the probability of +those interactions happening + +on a null model, given a total +number of interactions end in + +ca and cb is given by +the hypergeometric. + +OK. + +So that's one way of going +about assessing whether or not + +the interactions we +see are significant. + +Now, let me ask you a +slightly different question. + +Right. + +Imagine that I have-- and +I'm being very generous here. + +Imagine that I have +two experiment-- that's + +the wrong size bubbles. + +I don't want to mislead you. + +One of your friends +comes to you and say, + +"I've done this +experiment twice." + +Twice, OK. + +"And each time I get +1,000 interactions. + +So each one gives +you 1,000, let's say. + +And I have 900 that are common +between the two replicates. + +And your friend says, +"how many interactions + +do you think there +are in total?" + +How could we estimate that? + +Well, what's interesting +about this problem + +is that what we're +asking is what's n? + +Right. + +What's the total number of +interactions of which we're + +observing this set and this set +of which 900 is overlapping. + +There's the hyperlink +geometric again. + +So all we need to do is to find +the maximum value, the best + +value for n that predicts the +observed overlap given that we + +have two experiments +of size, with m + +and n different observations, +and we have an overlap of k. + +OK. + +Does that makes +sense to everybody? + +Of how to estimate the +total number of interactions + +out there making a +set of assumption that + +they're all equally likely. + +Any questions about that at all? + +OK. + +And, just so you know, you can +approximate this, this way. + +Which is that the maximum +likelihood estimate + +of the total number +of interactions + +is approximately +n times n over k, + +as seen by the +approximation on the bottom. + +OK? + +Just so that you can +approximate how many things + +are out there that you +haven't seen when you've + +done a couple of replicates. + +OK, you guys have +been totally great. + +We've talked about a +lot of different things + +today in chromatin +architecture and structure. + +Sort of the DC to light +version of chromatin structure + +and architecture lecture. + +Next time we're going +to talk about building + +genetic models of EQTLs. + +And the time after +that we're going + +to talk about human genetics. + +Thank you so much. + +Have a great, long weekend. + +We'll see you next Thursday. \ No newline at end of file diff --git a/iZX8WEGZTVw.txt b/iZX8WEGZTVw.txt new file mode 100644 index 0000000000000000000000000000000000000000..0c1f73b793fabbb7df5f6209f6b6162712486ba5 --- /dev/null +++ b/iZX8WEGZTVw.txt @@ -0,0 +1,2939 @@ +align:start position:0% + +so some of the standard questions that + + align:start position:0% +so some of the standard questions that + + + align:start position:0% +so some of the standard questions that +we've examined already about random + + align:start position:0% +we've examined already about random + + + align:start position:0% +we've examined already about random +graphs are the probability of getting + + align:start position:0% +graphs are the probability of getting + + + align:start position:0% +graphs are the probability of getting +from one place to another or the + + align:start position:0% +from one place to another or the + + + align:start position:0% +from one place to another or the +expected time to get from one place to + + align:start position:0% +expected time to get from one place to + + + align:start position:0% +expected time to get from one place to +another but a different kind of question + + align:start position:0% +another but a different kind of question + + + align:start position:0% +another but a different kind of question +that comes up in a fundamental way is + + align:start position:0% +that comes up in a fundamental way is + + + align:start position:0% +that comes up in a fundamental way is +the probability of being someplace so + + align:start position:0% +the probability of being someplace so + + + align:start position:0% +the probability of being someplace so +let's examine that here is the graph + + align:start position:0% +let's examine that here is the graph + + + align:start position:0% +let's examine that here is the graph +with a states blue orange and green that + + align:start position:0% +with a states blue orange and green that + + + align:start position:0% +with a states blue orange and green that +we've seen before and suppose that I + + align:start position:0% +we've seen before and suppose that I + + + align:start position:0% +we've seen before and suppose that I +start at state B and I ask what's the + + align:start position:0% +start at state B and I ask what's the + + + align:start position:0% +start at state B and I ask what's the +probability of being at each of these + + align:start position:0% +probability of being at each of these + + + align:start position:0% +probability of being at each of these +states after one step so to start with + + align:start position:0% +states after one step so to start with + + + align:start position:0% +states after one step so to start with +I'm interested in PBP o + PG which is + + align:start position:0% +I'm interested in PBP o + PG which is + + + align:start position:0% +I'm interested in PBP o + PG which is +the probability of being at state B the + + align:start position:0% +the probability of being at state B the + + + align:start position:0% +the probability of being at state B the +probability of being at state o and the + + align:start position:0% +probability of being at state o and the + + + align:start position:0% +probability of being at state o and the +probability of being at state G the sum + + align:start position:0% +probability of being at state G the sum + + + align:start position:0% +probability of being at state G the sum +of the probabilities is going to be one + + align:start position:0% +of the probabilities is going to be one + + + align:start position:0% +of the probabilities is going to be one +and initially when I tell you that I'm + + align:start position:0% +and initially when I tell you that I'm + + + align:start position:0% +and initially when I tell you that I'm +at state B it means the probability of + + align:start position:0% +at state B it means the probability of + + + align:start position:0% +at state B it means the probability of +being at B is 1 and the other two is 0 + + align:start position:0% +being at B is 1 and the other two is 0 + + + align:start position:0% +being at B is 1 and the other two is 0 +and I'm interested in the way that these + + align:start position:0% +and I'm interested in the way that these + + + align:start position:0% +and I'm interested in the way that these +probabilities update after one step if P + + align:start position:0% +probabilities update after one step if P + + + align:start position:0% +probabilities update after one step if P +prime B is the probability of being in + + align:start position:0% +prime B is the probability of being in + + + align:start position:0% +prime B is the probability of being in +state B after one step and P prime 0 o + + align:start position:0% +state B after one step and P prime 0 o + + + align:start position:0% +state B after one step and P prime 0 o +is the probability of being in the + + align:start position:0% +is the probability of being in the + + + align:start position:0% +is the probability of being in the +orange state one step later and likewise + + align:start position:0% +orange state one step later and likewise + + + align:start position:0% +orange state one step later and likewise +for green what are these probabilities + + align:start position:0% +for green what are these probabilities + + + align:start position:0% +for green what are these probabilities +well it's easy to see just reading off + + align:start position:0% +well it's easy to see just reading off + + + align:start position:0% +well it's easy to see just reading off +this graph that the only place you're at + + align:start position:0% +this graph that the only place you're at + + + align:start position:0% +this graph that the only place you're at +is B so the only way to get probability + + align:start position:0% +is B so the only way to get probability + + + align:start position:0% +is B so the only way to get probability +of being somewhere is by looking + + align:start position:0% +of being somewhere is by looking + + + align:start position:0% +of being somewhere is by looking +following an edge out of B so the + + align:start position:0% +following an edge out of B so the + + + align:start position:0% +following an edge out of B so the +probability of being at one step at the + + align:start position:0% +probability of being at one step at the + + + align:start position:0% +probability of being at one step at the +orange vertex is 1/4 and it's like wise + + align:start position:0% +orange vertex is 1/4 and it's like wise + + + align:start position:0% +orange vertex is 1/4 and it's like wise +1/4 for being at the green state and + + align:start position:0% +1/4 for being at the green state and + + + align:start position:0% +1/4 for being at the green state and +it's 1/2 for staying at the blue state + + align:start position:0% +it's 1/2 for staying at the blue state + + + align:start position:0% +it's 1/2 for staying at the blue state +so what we can say is that the updated + + align:start position:0% +so what we can say is that the updated + + + align:start position:0% +so what we can say is that the updated +probabilities of being at these + + align:start position:0% +probabilities of being at these + + + align:start position:0% +probabilities of being at these +different states is 1/2 1/4 and 1/4 as + + align:start position:0% +different states is 1/2 1/4 and 1/4 as + + + align:start position:0% +different states is 1/2 1/4 and 1/4 as +we've just reasoned ok let's keep going + + align:start position:0% +we've just reasoned ok let's keep going + + + align:start position:0% +we've just reasoned ok let's keep going +given that the probability that I'm at + + align:start position:0% +given that the probability that I'm at + + + align:start position:0% +given that the probability that I'm at +the States blue orange and green are + + align:start position:0% +the States blue orange and green are + + + align:start position:0% +the States blue orange and green are +given by this vector of probabilities + + align:start position:0% +given by this vector of probabilities + + + align:start position:0% +given by this vector of probabilities +what's the distribution after 2 steps so + + align:start position:0% +what's the distribution after 2 steps so + + + align:start position:0% +what's the distribution after 2 steps so +let P double prime B be the probability + + align:start position:0% +let P double prime B be the probability + + + align:start position:0% +let P double prime B be the probability +of being in state B after 2 steps + + align:start position:0% +of being in state B after 2 steps + + + align:start position:0% +of being in state B after 2 steps +starting from B well the way we can + + align:start position:0% +starting from B well the way we can + + + align:start position:0% +starting from B well the way we can +figure that out + + align:start position:0% +figure that out + + + align:start position:0% +figure that out +is by using conditional probabilities + + align:start position:0% +is by using conditional probabilities + + + align:start position:0% +is by using conditional probabilities +let's look at the example of the + + align:start position:0% +let's look at the example of the + + + align:start position:0% +let's look at the example of the +probability calculating the probability + + align:start position:0% +probability calculating the probability + + + align:start position:0% +probability calculating the probability +of being in the orange state two steps + + align:start position:0% +of being in the orange state two steps + + + align:start position:0% +of being in the orange state two steps +after you've started at the blue state + + align:start position:0% +after you've started at the blue state + + + align:start position:0% +after you've started at the blue state +so here is the probabilities of being at + + align:start position:0% +so here is the probabilities of being at + + + align:start position:0% +so here is the probabilities of being at +the different states after one step how + + align:start position:0% +the different states after one step how + + + align:start position:0% +the different states after one step how +do I get to the arn state well I can get + + align:start position:0% +do I get to the arn state well I can get + + + align:start position:0% +do I get to the arn state well I can get +to the orange state from the blue state + + align:start position:0% +to the orange state from the blue state + + + align:start position:0% +to the orange state from the blue state +and so the probability of being in the + + align:start position:0% +and so the probability of being in the + + + align:start position:0% +and so the probability of being in the +orange state after two steps is the + + align:start position:0% +orange state after two steps is the + + + align:start position:0% +orange state after two steps is the +probability of being at the blue state + + align:start position:0% +probability of being at the blue state + + + align:start position:0% +probability of being at the blue state +after one step times the probability + + align:start position:0% +after one step times the probability + + + align:start position:0% +after one step times the probability +that I take this edge to the orange + + align:start position:0% +that I take this edge to the orange + + + align:start position:0% +that I take this edge to the orange +state that is it's the probability of + + align:start position:0% +state that is it's the probability of + + + align:start position:0% +state that is it's the probability of +going from B to Oh + + align:start position:0% +going from B to Oh + + + align:start position:0% +going from B to Oh +given that I'm at B times the + + align:start position:0% +given that I'm at B times the + + + align:start position:0% +given that I'm at B times the +probability of being in B after one step + + align:start position:0% +probability of being in B after one step + + + align:start position:0% +probability of being in B after one step +this then is the probability of being + + align:start position:0% +this then is the probability of being + + + align:start position:0% +this then is the probability of being +and Oh after two steps and likewise the + + align:start position:0% +and Oh after two steps and likewise the + + + align:start position:0% +and Oh after two steps and likewise the +probability of being oh another + + align:start position:0% +probability of being oh another + + + align:start position:0% +probability of being oh another +component of the probability of being at + + align:start position:0% +component of the probability of being at + + + align:start position:0% +component of the probability of being at +O is that if you're a toe and you what's + + align:start position:0% +O is that if you're a toe and you what's + + + align:start position:0% +O is that if you're a toe and you what's +the probability of going from o to O and + + align:start position:0% +the probability of going from o to O and + + + align:start position:0% +the probability of going from o to O and +that is this one third times the + + align:start position:0% +that is this one third times the + + + align:start position:0% +that is this one third times the +probability of being at all at all which + + align:start position:0% +probability of being at all at all which + + + align:start position:0% +probability of being at all at all which +is a quarter and the final case using + + align:start position:0% +is a quarter and the final case using + + + align:start position:0% +is a quarter and the final case using +again took the law of total probability + + align:start position:0% +again took the law of total probability + + + align:start position:0% +again took the law of total probability +breaking it up into cases the third way + + align:start position:0% +breaking it up into cases the third way + + + align:start position:0% +breaking it up into cases the third way +that I can get to the iron state on step + + align:start position:0% +that I can get to the iron state on step + + + align:start position:0% +that I can get to the iron state on step +two is by being at the green state on + + align:start position:0% +two is by being at the green state on + + + align:start position:0% +two is by being at the green state on +step one following the green to O edge + + align:start position:0% +step one following the green to O edge + + + align:start position:0% +step one following the green to O edge +of which there isn't any so that's gonna + + align:start position:0% +of which there isn't any so that's gonna + + + align:start position:0% +of which there isn't any so that's gonna +be probability zero times the + + align:start position:0% +be probability zero times the + + + align:start position:0% +be probability zero times the +probability of being at the green state + + align:start position:0% +probability of being at the green state + + + align:start position:0% +probability of being at the green state +which is a quarter but it won't matter + + align:start position:0% +which is a quarter but it won't matter + + + align:start position:0% +which is a quarter but it won't matter +so let's just fill in these amounts + + align:start position:0% +so let's just fill in these amounts + + + align:start position:0% +so let's just fill in these amounts +looking at the first term the + + align:start position:0% +looking at the first term the + + + align:start position:0% +looking at the first term the +probability of going from B to o when + + align:start position:0% +probability of going from B to o when + + + align:start position:0% +probability of going from B to o when +you're at B is simply the probability of + + align:start position:0% +you're at B is simply the probability of + + + align:start position:0% +you're at B is simply the probability of +this edge it's a quarter and likewise + + align:start position:0% +this edge it's a quarter and likewise + + + align:start position:0% +this edge it's a quarter and likewise +the probability of going from o to O + + align:start position:0% +the probability of going from o to O + + + align:start position:0% +the probability of going from o to O +given that you're at O is the + + align:start position:0% +given that you're at O is the + + + align:start position:0% +given that you're at O is the +probability of this edge namely a third + + align:start position:0% +probability of this edge namely a third + + + align:start position:0% +probability of this edge namely a third +so we can fill that term in and finally + + align:start position:0% +so we can fill that term in and finally + + + align:start position:0% +so we can fill that term in and finally +the probability of going from G to O is + + align:start position:0% +the probability of going from G to O is + + + align:start position:0% +the probability of going from G to O is +zero given that you're at G because + + align:start position:0% +zero given that you're at G because + + + align:start position:0% +zero given that you're at G because +there isn't any vertex there and then + + align:start position:0% +there isn't any vertex there and then + + + align:start position:0% +there isn't any vertex there and then +you fill in those probabilities and + + align:start position:0% +you fill in those probabilities and + + + align:start position:0% +you fill in those probabilities and +do the arithmetic you come out with a + + align:start position:0% +do the arithmetic you come out with a + + + align:start position:0% +do the arithmetic you come out with a +five twenty fourth problem probability + + align:start position:0% +five twenty fourth problem probability + + + align:start position:0% +five twenty fourth problem probability +of being in the orange state after two + + align:start position:0% +of being in the orange state after two + + + align:start position:0% +of being in the orange state after two +steps well the same calculation you can + + align:start position:0% +steps well the same calculation you can + + + align:start position:0% +steps well the same calculation you can +figure out what's the probability of + + align:start position:0% +figure out what's the probability of + + + align:start position:0% +figure out what's the probability of +being at the blue state or the green + + align:start position:0% +being at the blue state or the green + + + align:start position:0% +being at the blue state or the green +step after two steps and there's the + + align:start position:0% +step after two steps and there's the + + + align:start position:0% +step after two steps and there's the +answer there's a 50/50 chance of being + + align:start position:0% +answer there's a 50/50 chance of being + + + align:start position:0% +answer there's a 50/50 chance of being +in the blue state after two steps five + + align:start position:0% +in the blue state after two steps five + + + align:start position:0% +in the blue state after two steps five +twenty fourth as we saw at the orange + + align:start position:0% +twenty fourth as we saw at the orange + + + align:start position:0% +twenty fourth as we saw at the orange +state and the rest of it it is seven + + align:start position:0% +state and the rest of it it is seven + + + align:start position:0% +state and the rest of it it is seven +twenty fourth is the probability of + + align:start position:0% +twenty fourth is the probability of + + + align:start position:0% +twenty fourth is the probability of +being at the green state okay so what's + + align:start position:0% +being at the green state okay so what's + + + align:start position:0% +being at the green state okay so what's +going on in general and we can explain + + align:start position:0% +going on in general and we can explain + + + align:start position:0% +going on in general and we can explain +how to do these calculations by using a + + align:start position:0% +how to do these calculations by using a + + + align:start position:0% +how to do these calculations by using a +little bit of linear algebra so let's + + align:start position:0% +little bit of linear algebra so let's + + + align:start position:0% +little bit of linear algebra so let's +define the edge probability matrix of a + + align:start position:0% +define the edge probability matrix of a + + + align:start position:0% +define the edge probability matrix of a +random walk graph is just the adjacency + + align:start position:0% +random walk graph is just the adjacency + + + align:start position:0% +random walk graph is just the adjacency +matrix of the graph except that instead + + align:start position:0% +matrix of the graph except that instead + + + align:start position:0% +matrix of the graph except that instead +of using zeros and ones to indicate + + align:start position:0% +of using zeros and ones to indicate + + + align:start position:0% +of using zeros and ones to indicate +whether an edges not present or present + + align:start position:0% +whether an edges not present or present + + + align:start position:0% +whether an edges not present or present +I'll use in that in the put in the IJ + + align:start position:0% +I'll use in that in the put in the IJ + + + align:start position:0% +I'll use in that in the put in the IJ +position of the matrix the probability + + align:start position:0% +position of the matrix the probability + + + align:start position:0% +position of the matrix the probability +of the edge that goes from I to J if + + align:start position:0% +of the edge that goes from I to J if + + + align:start position:0% +of the edge that goes from I to J if +there is an engine zero if there isn't + + align:start position:0% +there is an engine zero if there isn't + + + align:start position:0% +there is an engine zero if there isn't +any edge let's look at an example so + + align:start position:0% +any edge let's look at an example so + + + align:start position:0% +any edge let's look at an example so +here is the way we would fill it in + + align:start position:0% +here is the way we would fill it in + + + align:start position:0% +here is the way we would fill it in +abstractly for our three state graph + + align:start position:0% +abstractly for our three state graph + + + align:start position:0% +abstractly for our three state graph +it'll be a three by three matrix with + + align:start position:0% +it'll be a three by three matrix with + + + align:start position:0% +it'll be a three by three matrix with +the probabilities of the successive + + align:start position:0% +the probabilities of the successive + + + align:start position:0% +the probabilities of the successive +edges in the corresponding position so + + align:start position:0% +edges in the corresponding position so + + + align:start position:0% +edges in the corresponding position so +this is the position in the the BB + + align:start position:0% +this is the position in the the BB + + + align:start position:0% +this is the position in the the BB +coordinate is the probability of the + + align:start position:0% +coordinate is the probability of the + + + align:start position:0% +coordinate is the probability of the +edge from B to be the Oh B coordinate if + + align:start position:0% +edge from B to be the Oh B coordinate if + + + align:start position:0% +edge from B to be the Oh B coordinate if +you think of the columns as labeled blue + + align:start position:0% +you think of the columns as labeled blue + + + align:start position:0% +you think of the columns as labeled blue +blue orange green and the Roses labeled + + align:start position:0% +blue orange green and the Roses labeled + + + align:start position:0% +blue orange green and the Roses labeled +blue orange green this is the orange + + align:start position:0% +blue orange green this is the orange + + + align:start position:0% +blue orange green this is the orange +blue coordinate and it's the probability + + align:start position:0% +blue coordinate and it's the probability + + + align:start position:0% +blue coordinate and it's the probability +of the edge from zero to B let's fill in + + align:start position:0% +of the edge from zero to B let's fill in + + + align:start position:0% +of the edge from zero to B let's fill in +the first row which was this is just red + + align:start position:0% +the first row which was this is just red + + + align:start position:0% +the first row which was this is just red +directly off the graph it was the edges + + align:start position:0% +directly off the graph it was the edges + + + align:start position:0% +directly off the graph it was the edges +out of B that went from B to B from B to + + align:start position:0% +out of B that went from B to B from B to + + + align:start position:0% +out of B that went from B to B from B to +oh and from Beata + + align:start position:0% +oh and from Beata + + + align:start position:0% +oh and from Beata +great G and it had those weights and if + + align:start position:0% +great G and it had those weights and if + + + align:start position:0% +great G and it had those weights and if +I fill in the rest of it I get the the + + align:start position:0% +I fill in the rest of it I get the the + + + align:start position:0% +I fill in the rest of it I get the the +edge probability matrix for our simple + + align:start position:0% +edge probability matrix for our simple + + + align:start position:0% +edge probability matrix for our simple +three state graph and there it is so + + align:start position:0% +three state graph and there it is so + + + align:start position:0% +three state graph and there it is so +this last one is the shows the fact that + + align:start position:0% +this last one is the shows the fact that + + + align:start position:0% +this last one is the shows the fact that +there is and there's a certain edge from + + align:start position:0% +there is and there's a certain edge from + + + align:start position:0% +there is and there's a certain edge from +green to blue the only place you can go + + align:start position:0% +green to blue the only place you can go + + + align:start position:0% +green to blue the only place you can go +from green is to + + align:start position:0% +from green is to + + + align:start position:0% +from green is to +below and you can't go to either orange + + align:start position:0% +below and you can't go to either orange + + + align:start position:0% +below and you can't go to either orange +or green in one step okay so why are we + + align:start position:0% +or green in one step okay so why are we + + + align:start position:0% +or green in one step okay so why are we +bringing up the matrix well if you + + align:start position:0% +bringing up the matrix well if you + + + align:start position:0% +bringing up the matrix well if you +looked at the way we updated the state + + align:start position:0% +looked at the way we updated the state + + + align:start position:0% +looked at the way we updated the state +to go from the the one-step distribution + + align:start position:0% +to go from the the one-step distribution + + + align:start position:0% +to go from the the one-step distribution +to the toe step distribution it was + + align:start position:0% +to the toe step distribution it was + + + align:start position:0% +to the toe step distribution it was +really a matrix multiply and in general + + align:start position:0% +really a matrix multiply and in general + + + align:start position:0% +really a matrix multiply and in general +to do an update you're just going to do + + align:start position:0% +to do an update you're just going to do + + + align:start position:0% +to do an update you're just going to do +a vector matrix multiplication if you + + align:start position:0% +a vector matrix multiplication if you + + + align:start position:0% +a vector matrix multiplication if you +have the probabilities of being in the + + align:start position:0% +have the probabilities of being in the + + + align:start position:0% +have the probabilities of being in the +successive states B oh and G and you + + align:start position:0% +successive states B oh and G and you + + + align:start position:0% +successive states B oh and G and you +won't do a matrix vector matrix + + align:start position:0% +won't do a matrix vector matrix + + + align:start position:0% +won't do a matrix vector matrix +multiplication using the the probability + + align:start position:0% +multiplication using the the probability + + + align:start position:0% +multiplication using the the probability +matrix of the graph you get the updated + + align:start position:0% +matrix of the graph you get the updated + + + align:start position:0% +matrix of the graph you get the updated +and vector of distributions and that's + + align:start position:0% +and vector of distributions and that's + + + align:start position:0% +and vector of distributions and that's +easy to check just from the definitions + + align:start position:0% +easy to check just from the definitions + + + align:start position:0% +easy to check just from the definitions +and from the definition of vector times + + align:start position:0% +and from the definition of vector times + + + align:start position:0% +and from the definition of vector times +matrix which I assume you're familiar + + align:start position:0% +matrix which I assume you're familiar + + + align:start position:0% +matrix which I assume you're familiar +with so now we can ask what's the + + align:start position:0% +with so now we can ask what's the + + + align:start position:0% +with so now we can ask what's the +distribution after T steps starting from + + align:start position:0% +distribution after T steps starting from + + + align:start position:0% +distribution after T steps starting from +some particular given distribution say + + align:start position:0% +some particular given distribution say + + + align:start position:0% +some particular given distribution say +starting in state B or starting at any + + align:start position:0% +starting in state B or starting at any + + + align:start position:0% +starting in state B or starting at any +possible distribution of probabilities + + align:start position:0% +possible distribution of probabilities + + + align:start position:0% +possible distribution of probabilities +to the different states and the way that + + align:start position:0% +to the different states and the way that + + + align:start position:0% +to the different states and the way that +we can figure that out so I'm interested + + align:start position:0% +we can figure that out so I'm interested + + + align:start position:0% +we can figure that out so I'm interested +in other words is the probability of + + align:start position:0% +in other words is the probability of + + + align:start position:0% +in other words is the probability of +being in oh a fter T steps G after T + + align:start position:0% +being in oh a fter T steps G after T + + + align:start position:0% +being in oh a fter T steps G after T +steps and bf2 T steps say starting from + + align:start position:0% +steps and bf2 T steps say starting from + + + align:start position:0% +steps and bf2 T steps say starting from +state B and what happens also as T + + align:start position:0% +state B and what happens also as T + + + align:start position:0% +state B and what happens also as T +approaches infinity these are sort of + + align:start position:0% +approaches infinity these are sort of + + + align:start position:0% +approaches infinity these are sort of +two basic questions that we're going to + + align:start position:0% +two basic questions that we're going to + + + align:start position:0% +two basic questions that we're going to +be asking so first of all how do you + + align:start position:0% +be asking so first of all how do you + + + align:start position:0% +be asking so first of all how do you +calculate starting and a given + + align:start position:0% +calculate starting and a given + + + align:start position:0% +calculate starting and a given +distribution P bpop G where you're gonna + + align:start position:0% +distribution P bpop G where you're gonna + + + align:start position:0% +distribution P bpop G where you're gonna +be after T steps well you're just + + align:start position:0% +be after T steps well you're just + + + align:start position:0% +be after T steps well you're just +continually updating which means if I'm + + align:start position:0% +continually updating which means if I'm + + + align:start position:0% +continually updating which means if I'm +multiplying by M T times so the + + align:start position:0% +multiplying by M T times so the + + + align:start position:0% +multiplying by M T times so the +distribution after T steps is gotten by + + align:start position:0% +distribution after T steps is gotten by + + + align:start position:0% +distribution after T steps is gotten by +taking the initial distribution times + + align:start position:0% +taking the initial distribution times + + + align:start position:0% +taking the initial distribution times +the teeth power of M now this is + + align:start position:0% +the teeth power of M now this is + + + align:start position:0% +the teeth power of M now this is +actually already useful computationally + + align:start position:0% +actually already useful computationally + + + align:start position:0% +actually already useful computationally +because it means that since you can + + align:start position:0% +because it means that since you can + + + align:start position:0% +because it means that since you can +compute a matrix power by successive + + align:start position:0% +compute a matrix power by successive + + + align:start position:0% +compute a matrix power by successive +squarings + + align:start position:0% +squarings + + + align:start position:0% +squarings +you actually only need about log of T + + align:start position:0% +you actually only need about log of T + + + align:start position:0% +you actually only need about log of T +matrix multiplications in order to be + + align:start position:0% +matrix multiplications in order to be + + + align:start position:0% +matrix multiplications in order to be +able to figure out what's the + + align:start position:0% +able to figure out what's the + + + align:start position:0% +able to figure out what's the +distribution of probabilities on the + + align:start position:0% +distribution of probabilities on the + + + align:start position:0% +distribution of probabilities on the +after T steps of the of the graph then + + align:start position:0% +after T steps of the of the graph then + + + align:start position:0% +after T steps of the of the graph then +the push + + align:start position:0% +the push + + + align:start position:0% +the push +a concept that we want to examine and + + align:start position:0% +a concept that we want to examine and + + + align:start position:0% +a concept that we want to examine and +we'll make a lot of use of in the next + + align:start position:0% +we'll make a lot of use of in the next + + + align:start position:0% +we'll make a lot of use of in the next +video and we talked about a PageRank is + + align:start position:0% +video and we talked about a PageRank is + + + align:start position:0% +video and we talked about a PageRank is +the idea of a stationary distribution so + + align:start position:0% +the idea of a stationary distribution so + + + align:start position:0% +the idea of a stationary distribution so +a stationary distribution means that + + align:start position:0% +a stationary distribution means that + + + align:start position:0% +a stationary distribution means that +that once you're in the state a + + align:start position:0% +that once you're in the state a + + + align:start position:0% +that once you're in the state a +stationary distribution it's stable + + align:start position:0% +stationary distribution it's stable + + + align:start position:0% +stationary distribution it's stable +you're gonna say stay in that + + align:start position:0% +you're gonna say stay in that + + + align:start position:0% +you're gonna say stay in that +distribution you're not gonna be in any + + align:start position:0% +distribution you're not gonna be in any + + + align:start position:0% +distribution you're not gonna be in any +particular state but the but you'll have + + align:start position:0% +particular state but the but you'll have + + + align:start position:0% +particular state but the but you'll have +a vector of probabilities of being in + + align:start position:0% +a vector of probabilities of being in + + + align:start position:0% +a vector of probabilities of being in +the different states and one step later + + align:start position:0% +the different states and one step later + + + align:start position:0% +the different states and one step later +that vectors not going to change so what + + align:start position:0% +that vectors not going to change so what + + + align:start position:0% +that vectors not going to change so what +it means is that the next step + + align:start position:0% +it means is that the next step + + + align:start position:0% +it means is that the next step +distribution is the same as the current + + align:start position:0% +distribution is the same as the current + + + align:start position:0% +distribution is the same as the current +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +what's the stable what's a stationary + + align:start position:0% +what's the stable what's a stationary + + + align:start position:0% +what's the stable what's a stationary +distribution here well the way we're + + align:start position:0% +distribution here well the way we're + + + align:start position:0% +distribution here well the way we're +gonna have to calculate that is here's + + align:start position:0% +gonna have to calculate that is here's + + + align:start position:0% +gonna have to calculate that is here's +how you update this is the result of the + + align:start position:0% +how you update this is the result of the + + + align:start position:0% +how you update this is the result of the +matrix of the vector matrix + + align:start position:0% +matrix of the vector matrix + + + align:start position:0% +matrix of the vector matrix +multiplication but let's just spell it + + align:start position:0% +multiplication but let's just spell it + + + align:start position:0% +multiplication but let's just spell it +out in terms of the conditional + + align:start position:0% +out in terms of the conditional + + + align:start position:0% +out in terms of the conditional +probabilities after one step if the + + align:start position:0% +probabilities after one step if the + + + align:start position:0% +probabilities after one step if the +original distribution is P B P OPG then + + align:start position:0% +original distribution is P B P OPG then + + + align:start position:0% +original distribution is P B P OPG then +the new probability of being in state B + + align:start position:0% +the new probability of being in state B + + + align:start position:0% +the new probability of being in state B +the only way you can get there is by + + align:start position:0% +the only way you can get there is by + + + align:start position:0% +the only way you can get there is by +being following the edge from B to B + + align:start position:0% +being following the edge from B to B + + + align:start position:0% +being following the edge from B to B +with probability 1/2 and that's times + + align:start position:0% +with probability 1/2 and that's times + + + align:start position:0% +with probability 1/2 and that's times +the probability of being at B and the + + align:start position:0% +the probability of being at B and the + + + align:start position:0% +the probability of being at B and the +other way you can get to B is by being + + align:start position:0% +other way you can get to B is by being + + + align:start position:0% +other way you can get to B is by being +at the green state and then one step + + align:start position:0% +at the green state and then one step + + + align:start position:0% +at the green state and then one step +later you're certain to be at bay so + + align:start position:0% +later you're certain to be at bay so + + + align:start position:0% +later you're certain to be at bay so +that adds a contribution of 1 times P G + + align:start position:0% +that adds a contribution of 1 times P G + + + align:start position:0% +that adds a contribution of 1 times P G +likewise for a P the updated probability + + align:start position:0% +likewise for a P the updated probability + + + align:start position:0% +likewise for a P the updated probability +of being at the orange state in the + + align:start position:0% +of being at the orange state in the + + + align:start position:0% +of being at the orange state in the +green state and what we want is that + + align:start position:0% +green state and what we want is that + + + align:start position:0% +green state and what we want is that +these updated probabilities are the same + + align:start position:0% +these updated probabilities are the same + + + align:start position:0% +these updated probabilities are the same +as the ones that I'm starting with + + align:start position:0% +as the ones that I'm starting with + + + align:start position:0% +as the ones that I'm starting with +that's the definition of stability you + + align:start position:0% +that's the definition of stability you + + + align:start position:0% +that's the definition of stability you +update the vector P bpop G and you get + + align:start position:0% +update the vector P bpop G and you get + + + align:start position:0% +update the vector P bpop G and you get +the same vector that's what makes it + + align:start position:0% +the same vector that's what makes it + + + align:start position:0% +the same vector that's what makes it +stable and of course a side constraint + + align:start position:0% +stable and of course a side constraint + + + align:start position:0% +stable and of course a side constraint +since you can always solve a system of + + align:start position:0% +since you can always solve a system of + + + align:start position:0% +since you can always solve a system of +equations like this by letting all the + + align:start position:0% +equations like this by letting all the + + + align:start position:0% +equations like this by letting all the +peas be 0 which is degenerate we add the + + align:start position:0% +peas be 0 which is degenerate we add the + + + align:start position:0% +peas be 0 which is degenerate we add the +constraint that the sum of the + + align:start position:0% +constraint that the sum of the + + + align:start position:0% +constraint that the sum of the +probabilities of being in the States has + + align:start position:0% +probabilities of being in the States has + + + align:start position:0% +probabilities of being in the States has +to be 1 well if we solve the a simple 3 + + align:start position:0% +to be 1 well if we solve the a simple 3 + + + align:start position:0% +to be 1 well if we solve the a simple 3 +by 3 system of equations then it turns + + align:start position:0% +by 3 system of equations then it turns + + + align:start position:0% +by 3 system of equations then it turns +out that the stable distribution is + + align:start position:0% +out that the stable distribution is + + + align:start position:0% +out that the stable distribution is +there's an 8th 15th being in state B a 3 + + align:start position:0% +there's an 8th 15th being in state B a 3 + + + align:start position:0% +there's an 8th 15th being in state B a 3 +15th chance of being in state orange and + + align:start position:0% +15th chance of being in state orange and + + + align:start position:0% +15th chance of being in state orange and +a 4 15th state chance of being in state + + align:start position:0% +a 4 15th state chance of being in state + + + align:start position:0% +a 4 15th state chance of being in state +green and + + align:start position:0% +green and + + + align:start position:0% +green and +should check that yourself by asking + + align:start position:0% +should check that yourself by asking + + + align:start position:0% +should check that yourself by asking +what's the probability of being in PB + + align:start position:0% +what's the probability of being in PB + + + align:start position:0% +what's the probability of being in PB +after one step given these probabilities + + align:start position:0% +after one step given these probabilities + + + align:start position:0% +after one step given these probabilities +and I'm not going to talk you through + + align:start position:0% +and I'm not going to talk you through + + + align:start position:0% +and I'm not going to talk you through +that but just to verify and imprint the + + align:start position:0% +that but just to verify and imprint the + + + align:start position:0% +that but just to verify and imprint the +idea of stability that's one that's + + align:start position:0% +idea of stability that's one that's + + + align:start position:0% +idea of stability that's one that's +worth stopping the video for a moment to + + align:start position:0% +worth stopping the video for a moment to + + + align:start position:0% +worth stopping the video for a moment to +check and do a little arithmetic with a + + align:start position:0% +check and do a little arithmetic with a + + + align:start position:0% +check and do a little arithmetic with a +pencil and paper okay so in general what + + align:start position:0% +pencil and paper okay so in general what + + + align:start position:0% +pencil and paper okay so in general what +we're going to do is we're trying to + + align:start position:0% +we're going to do is we're trying to + + + align:start position:0% +we're going to do is we're trying to +find the stationary distribution vector + + align:start position:0% +find the stationary distribution vector + + + align:start position:0% +find the stationary distribution vector +called an S bar for vector and we get + + align:start position:0% +called an S bar for vector and we get + + + align:start position:0% +called an S bar for vector and we get +this by solving the the vector matrix + + align:start position:0% +this by solving the the vector matrix + + + align:start position:0% +this by solving the the vector matrix +equation that the distribution vector + + align:start position:0% +equation that the distribution vector + + + align:start position:0% +equation that the distribution vector +times the edge probability matrix is + + align:start position:0% +times the edge probability matrix is + + + align:start position:0% +times the edge probability matrix is +equal to that same distribution vector + + align:start position:0% +equal to that same distribution vector + + + align:start position:0% +equal to that same distribution vector +we want to solve this system of + + align:start position:0% +we want to solve this system of + + + align:start position:0% +we want to solve this system of +equations if there are n states then + + align:start position:0% +equations if there are n states then + + + align:start position:0% +equations if there are n states then +this is an N by n system of equations + + align:start position:0% +this is an N by n system of equations + + + align:start position:0% +this is an N by n system of equations +with an additional constraint that we + + align:start position:0% +with an additional constraint that we + + + align:start position:0% +with an additional constraint that we +want the norm of the of the stable + + align:start position:0% +want the norm of the of the stable + + + align:start position:0% +want the norm of the of the stable +vector to be 1 because that's to avoid + + align:start position:0% +vector to be 1 because that's to avoid + + + align:start position:0% +vector to be 1 because that's to avoid +the degenerate zero solution well there + + align:start position:0% +the degenerate zero solution well there + + + align:start position:0% +the degenerate zero solution well there +are some problems with stationary + + align:start position:0% +are some problems with stationary + + + align:start position:0% +are some problems with stationary +distributions that we want to think + + align:start position:0% +distributions that we want to think + + + align:start position:0% +distributions that we want to think +about first of all what happens in this + + align:start position:0% +about first of all what happens in this + + + align:start position:0% +about first of all what happens in this +example where you have just two states + + align:start position:0% +example where you have just two states + + + align:start position:0% +example where you have just two states +and the probability of being the first + + align:start position:0% +and the probability of being the first + + + align:start position:0% +and the probability of being the first +stated one in the second state is 0 well + + align:start position:0% +stated one in the second state is 0 well + + + align:start position:0% +stated one in the second state is 0 well +if you update that state what happens is + + align:start position:0% +if you update that state what happens is + + + align:start position:0% +if you update that state what happens is +you go to this you just go to the second + + align:start position:0% +you go to this you just go to the second + + + align:start position:0% +you go to this you just go to the second +state with probability 1 and you can + + align:start position:0% +state with probability 1 and you can + + + align:start position:0% +state with probability 1 and you can +keep doing that and there may be a + + align:start position:0% +keep doing that and there may be a + + + align:start position:0% +keep doing that and there may be a +stable distribution here but this + + align:start position:0% +stable distribution here but this + + + align:start position:0% +stable distribution here but this +particular pattern doesn't converge to + + align:start position:0% +particular pattern doesn't converge to + + + align:start position:0% +particular pattern doesn't converge to +it as you go through time half the time + + align:start position:0% +it as you go through time half the time + + + align:start position:0% +it as you go through time half the time +you're at every other step your state 1 + + align:start position:0% +you're at every other step your state 1 + + + align:start position:0% +you're at every other step your state 1 +and every other step you're at state 0 + + align:start position:0% +and every other step you're at state 0 + + + align:start position:0% +and every other step you're at state 0 +but the you never get to the disk to a + + align:start position:0% +but the you never get to the disk to a + + + align:start position:0% +but the you never get to the disk to a +stable distribution where step after + + align:start position:0% +stable distribution where step after + + + align:start position:0% +stable distribution where step after +step you are at equal probability of + + align:start position:0% +step you are at equal probability of + + + align:start position:0% +step you are at equal probability of +being at these two places I'm assuming + + align:start position:0% +being at these two places I'm assuming + + + align:start position:0% +being at these two places I'm assuming +here that this is a certain edge and + + align:start position:0% +here that this is a certain edge and + + + align:start position:0% +here that this is a certain edge and +that's a certain edge it has to be + + align:start position:0% +that's a certain edge it has to be + + + align:start position:0% +that's a certain edge it has to be +there's only one edge out so a stable + + align:start position:0% +there's only one edge out so a stable + + + align:start position:0% +there's only one edge out so a stable +distribution would be 1/2 1/2 but this + + align:start position:0% +distribution would be 1/2 1/2 but this + + + align:start position:0% +distribution would be 1/2 1/2 but this +thing doesn't converge to it ok here's a + + align:start position:0% +thing doesn't converge to it ok here's a + + + align:start position:0% +thing doesn't converge to it ok here's a +slightly more complicated example where + + align:start position:0% +slightly more complicated example where + + + align:start position:0% +slightly more complicated example where +again assume that all the edges are + + align:start position:0% +again assume that all the edges are + + + align:start position:0% +again assume that all the edges are +equally likely there's exactly two edges + + align:start position:0% +equally likely there's exactly two edges + + + align:start position:0% +equally likely there's exactly two edges +out of each + + align:start position:0% +out of each + + + align:start position:0% +out of each +of these vertices so though each edge + + align:start position:0% +of these vertices so though each edge + + + align:start position:0% +of these vertices so though each edge +has weight 1/2 and the problem with this + + align:start position:0% +has weight 1/2 and the problem with this + + + align:start position:0% +has weight 1/2 and the problem with this +graph is that when you ask what's the + + align:start position:0% +graph is that when you ask what's the + + + align:start position:0% +graph is that when you ask what's the +stable distribution and well if you look + + align:start position:0% +stable distribution and well if you look + + + align:start position:0% +stable distribution and well if you look +at it if you assume that the probability + + align:start position:0% +at it if you assume that the probability + + + align:start position:0% +at it if you assume that the probability +of being in the middle is 0 and the two + + align:start position:0% +of being in the middle is 0 and the two + + + align:start position:0% +of being in the middle is 0 and the two +places that you get stuck at have + + align:start position:0% +places that you get stuck at have + + + align:start position:0% +places that you get stuck at have +probability P and 1 minus P then that's + + align:start position:0% +probability P and 1 minus P then that's + + + align:start position:0% +probability P and 1 minus P then that's +stable because once you're at this state + + align:start position:0% +stable because once you're at this state + + + align:start position:0% +stable because once you're at this state +with probability P you're following the + + align:start position:0% +with probability P you're following the + + + align:start position:0% +with probability P you're following the +1 certain edge that goes back around to + + align:start position:0% +1 certain edge that goes back around to + + + align:start position:0% +1 certain edge that goes back around to +this vertex and therefore this + + align:start position:0% +this vertex and therefore this + + + align:start position:0% +this vertex and therefore this +probability of P of being there one step + + align:start position:0% +probability of P of being there one step + + + align:start position:0% +probability of P of being there one step +later and likewise probability Q of one + + align:start position:0% +later and likewise probability Q of one + + + align:start position:0% +later and likewise probability Q of one +step later so the split between P and Q + + align:start position:0% +step later so the split between P and Q + + + align:start position:0% +step later so the split between P and Q +is a stable distribution for this thing + + align:start position:0% +is a stable distribution for this thing + + + align:start position:0% +is a stable distribution for this thing +with probability 0 and 0 there and of + + align:start position:0% +with probability 0 and 0 there and of + + + align:start position:0% +with probability 0 and 0 there and of +course P and Q can be any real numbers + + align:start position:0% +course P and Q can be any real numbers + + + align:start position:0% +course P and Q can be any real numbers +between 0 & 1 so there's actually an + + align:start position:0% +between 0 & 1 so there's actually an + + + align:start position:0% +between 0 & 1 so there's actually an +uncountable number of stable + + align:start position:0% +uncountable number of stable + + + align:start position:0% +uncountable number of stable +distributions for this graph problem + + align:start position:0% +distributions for this graph problem + + + align:start position:0% +distributions for this graph problem +here is it's not strongly connected and + + align:start position:0% +here is it's not strongly connected and + + + align:start position:0% +here is it's not strongly connected and +that turns out to be a sufficient + + align:start position:0% +that turns out to be a sufficient + + + align:start position:0% +that turns out to be a sufficient +condition that it's got a stable + + align:start position:0% +condition that it's got a stable + + + align:start position:0% +condition that it's got a stable +distribution whenever it's strongly + + align:start position:0% +distribution whenever it's strongly + + + align:start position:0% +distribution whenever it's strongly +connected so in general we can ask the + + align:start position:0% +connected so in general we can ask the + + + align:start position:0% +connected so in general we can ask the +question is there always stable a + + align:start position:0% +question is there always stable a + + + align:start position:0% +question is there always stable a +stationary distribution for any random + + align:start position:0% +stationary distribution for any random + + + align:start position:0% +stationary distribution for any random +graph well if the graph is finite yes + + align:start position:0% +graph well if the graph is finite yes + + + align:start position:0% +graph well if the graph is finite yes +there's guaranteed to be a stationary + + align:start position:0% +there's guaranteed to be a stationary + + + align:start position:0% +there's guaranteed to be a stationary +distribution but is it unique + + align:start position:0% +distribution but is it unique + + + align:start position:0% +distribution but is it unique +well sometimes sometimes not if the + + align:start position:0% +well sometimes sometimes not if the + + + align:start position:0% +well sometimes sometimes not if the +graph is strongly connected it will be + + align:start position:0% +graph is strongly connected it will be + + + align:start position:0% +graph is strongly connected it will be +unique but we've seen examples where in + + align:start position:0% +unique but we've seen examples where in + + + align:start position:0% +unique but we've seen examples where in +the previous slide where it's not unique + + align:start position:0% +the previous slide where it's not unique + + + align:start position:0% +the previous slide where it's not unique +in fact it could be uncountably many and + + align:start position:0% +in fact it could be uncountably many and + + + align:start position:0% +in fact it could be uncountably many and +another crucial question is does a + + align:start position:0% +another crucial question is does a + + + align:start position:0% +another crucial question is does a +random walk approach the stable + + align:start position:0% +random walk approach the stable + + + align:start position:0% +random walk approach the stable +distribution no matter how you start and + + align:start position:0% +distribution no matter how you start and + + + align:start position:0% +distribution no matter how you start and +that first example was one where you + + align:start position:0% +that first example was one where you + + + align:start position:0% +that first example was one where you +went between the first state and the + + align:start position:0% +went between the first state and the + + + align:start position:0% +went between the first state and the +second state and isolated and it never + + align:start position:0% +second state and isolated and it never + + + align:start position:0% +second state and isolated and it never +converged on the stable distribution of + + align:start position:0% +converged on the stable distribution of + + + align:start position:0% +converged on the stable distribution of +1/2 and 1/2 in general it's nice when + + align:start position:0% +1/2 and 1/2 in general it's nice when + + + align:start position:0% +1/2 and 1/2 in general it's nice when +you can say that no matter how you start + + align:start position:0% +you can say that no matter how you start + + + align:start position:0% +you can say that no matter how you start +after a while things stabilize and you + + align:start position:0% +after a while things stabilize and you + + + align:start position:0% +after a while things stabilize and you +wind up at the unique stable + + align:start position:0% +wind up at the unique stable + + + align:start position:0% +wind up at the unique stable +distribution so sometimes it'll be the + + align:start position:0% +distribution so sometimes it'll be the + + + align:start position:0% +distribution so sometimes it'll be the +case that every distribution every + + align:start position:0% +case that every distribution every + + + align:start position:0% +case that every distribution every +initial distribution will eventually + + align:start position:0% +initial distribution will eventually + + + align:start position:0% +initial distribution will eventually +converge on the stable one + + align:start position:0% +converge on the stable one + + + align:start position:0% +converge on the stable one +the stationary one sometimes not and + + align:start position:0% +the stationary one sometimes not and + + + align:start position:0% +the stationary one sometimes not and +then another crucial question will be + + align:start position:0% +then another crucial question will be + + + align:start position:0% +then another crucial question will be +how quickly does this convergence happen + + align:start position:0% +how quickly does this convergence happen + + + align:start position:0% +how quickly does this convergence happen +if we start off at some arbitrary + + align:start position:0% +if we start off at some arbitrary + + + align:start position:0% +if we start off at some arbitrary +probability distribution or some + + align:start position:0% +probability distribution or some + + + align:start position:0% +probability distribution or some +particular state how long does it take + + align:start position:0% +particular state how long does it take + + + align:start position:0% +particular state how long does it take +before by and large the the + + align:start position:0% +before by and large the the + + + align:start position:0% +before by and large the the +probabilities that were in the different + + align:start position:0% +probabilities that were in the different + + + align:start position:0% +probabilities that were in the different +states has become pretty stationary and + + align:start position:0% +states has become pretty stationary and + + + align:start position:0% +states has become pretty stationary and +the rate at which that happens again + + align:start position:0% +the rate at which that happens again + + + align:start position:0% +the rate at which that happens again +varies depending on the graph \ No newline at end of file diff --git a/jeNPvqRXI9I.txt b/jeNPvqRXI9I.txt new file mode 100644 index 0000000000000000000000000000000000000000..6cc37e51f1e26c796f431ace5643503b6947b993 --- /dev/null +++ b/jeNPvqRXI9I.txt @@ -0,0 +1,6755 @@ +align:start position:0% + +and so I wanted to start today's lecture + + align:start position:0% +and so I wanted to start today's lecture + + + align:start position:0% +and so I wanted to start today's lecture +by continuing what we were talking about + + align:start position:0% +by continuing what we were talking about + + + align:start position:0% +by continuing what we were talking about +in the last lecture so I'm just gonna + + align:start position:0% +in the last lecture so I'm just gonna + + + align:start position:0% +in the last lecture so I'm just gonna +hide this real quick and so we are + + align:start position:0% +hide this real quick and so we are + + + align:start position:0% +hide this real quick and so we are +talking about the fruit fly and the + + align:start position:0% +talking about the fruit fly and the + + + align:start position:0% +talking about the fruit fly and the +white gene and the white mutant which + + align:start position:0% +white gene and the white mutant which + + + align:start position:0% +white gene and the white mutant which +results in white eyed flies and we + + align:start position:0% +results in white eyed flies and we + + + align:start position:0% +results in white eyed flies and we +talked about how if you take females + + align:start position:0% +talked about how if you take females + + + align:start position:0% +talked about how if you take females +that have red eyes and cross them to + + align:start position:0% +that have red eyes and cross them to + + + align:start position:0% +that have red eyes and cross them to +males the white-eyed male then a hundred + + align:start position:0% +males the white-eyed male then a hundred + + + align:start position:0% +males the white-eyed male then a hundred +percent of the progeny has red eyes in + + align:start position:0% +percent of the progeny has red eyes in + + + align:start position:0% +percent of the progeny has red eyes in +the f1 generation and so I asked you + + align:start position:0% +the f1 generation and so I asked you + + + align:start position:0% +the f1 generation and so I asked you +guys is would you get the same result if + + align:start position:0% +guys is would you get the same result if + + + align:start position:0% +guys is would you get the same result if +you did the reciprocal cross okay + + align:start position:0% +you did the reciprocal cross okay + + + align:start position:0% +you did the reciprocal cross okay +so what if we took white eyed females + + align:start position:0% +so what if we took white eyed females + + + align:start position:0% +so what if we took white eyed females +and mated them to red eyed males so what + + align:start position:0% +and mated them to red eyed males so what + + + align:start position:0% +and mated them to red eyed males so what +about this actually I'm gonna move this + + align:start position:0% +about this actually I'm gonna move this + + + align:start position:0% +about this actually I'm gonna move this +over to over here so that maybe it's + + align:start position:0% +over to over here so that maybe it's + + + align:start position:0% +over to over here so that maybe it's +more visible so what if we have white + + align:start position:0% +more visible so what if we have white + + + align:start position:0% +more visible so what if we have white +eyed females and cross this to red eyed + + align:start position:0% +eyed females and cross this to red eyed + + + align:start position:0% +eyed females and cross this to red eyed +males so let's unpack this sort of a + + align:start position:0% +males so let's unpack this sort of a + + + align:start position:0% +males so let's unpack this sort of a +little bit at a time so what's the + + align:start position:0% +little bit at a time so what's the + + + align:start position:0% +little bit at a time so what's the +genotype of these white eyed fina + + align:start position:0% +genotype of these white eyed fina + + + align:start position:0% +genotype of these white eyed fina +females here miles + + align:start position:0% + + + + align:start position:0% + +uh-huh yes okay so miles is exactly + + align:start position:0% +uh-huh yes okay so miles is exactly + + + align:start position:0% +uh-huh yes okay so miles is exactly +right so the dominant phenotype is red + + align:start position:0% +right so the dominant phenotype is red + + + align:start position:0% +right so the dominant phenotype is red +eyes because it's the gene encodes for + + align:start position:0% +eyes because it's the gene encodes for + + + align:start position:0% +eyes because it's the gene encodes for +an enzyme that's important for the + + align:start position:0% +an enzyme that's important for the + + + align:start position:0% +an enzyme that's important for the +production of the red pigment and so X + + align:start position:0% +production of the red pigment and so X + + + align:start position:0% +production of the red pigment and so X +lowercase a here would be a recessive + + align:start position:0% +lowercase a here would be a recessive + + + align:start position:0% +lowercase a here would be a recessive +mutant that lacks this that lacks the + + align:start position:0% +mutant that lacks this that lacks the + + + align:start position:0% +mutant that lacks this that lacks the +pigment okay and because it's a + + align:start position:0% +pigment okay and because it's a + + + align:start position:0% +pigment okay and because it's a +recessive allele because only you need + + align:start position:0% +recessive allele because only you need + + + align:start position:0% +recessive allele because only you need +only one copy of this gene to produce + + align:start position:0% +only one copy of this gene to produce + + + align:start position:0% +only one copy of this gene to produce +the pigment so the recessive allele + + align:start position:0% +the pigment so the recessive allele + + + align:start position:0% +the pigment so the recessive allele +results in the white phenotype therefore + + align:start position:0% +results in the white phenotype therefore + + + align:start position:0% +results in the white phenotype therefore +this has to be homozygous recessive okay + + align:start position:0% +this has to be homozygous recessive okay + + + align:start position:0% +this has to be homozygous recessive okay +how about this red eyed now yeah worry + + align:start position:0% +how about this red eyed now yeah worry + + + align:start position:0% +how about this red eyed now yeah worry +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +yes so this would be this phenotype + + align:start position:0% +yes so this would be this phenotype + + + align:start position:0% +yes so this would be this phenotype +right where capital a is the the gene + + align:start position:0% +right where capital a is the the gene + + + align:start position:0% +right where capital a is the the gene +that produces as a normal functioning + + align:start position:0% +that produces as a normal functioning + + + align:start position:0% +that produces as a normal functioning +gene that produces the pigment okay + + align:start position:0% +gene that produces the pigment okay + + + align:start position:0% +gene that produces the pigment okay +so then in your f1 here what are you + + align:start position:0% +so then in your f1 here what are you + + + align:start position:0% +so then in your f1 here what are you +gonna see something similar to this or + + align:start position:0% +gonna see something similar to this or + + + align:start position:0% +gonna see something similar to this or +something different different great who + + align:start position:0% +something different different great who + + + align:start position:0% +something different different great who +said different Javier do you want to + + align:start position:0% +said different Javier do you want to + + + align:start position:0% +said different Javier do you want to +propose what you might see + + align:start position:0% +propose what you might see + + + align:start position:0% +propose what you might see +[Music] + + align:start position:0% + + + + align:start position:0% + +exactly so the mouths are gonna get the + + align:start position:0% +exactly so the mouths are gonna get the + + + align:start position:0% +exactly so the mouths are gonna get the +Y from the father and they're gonna get + + align:start position:0% +Y from the father and they're gonna get + + + align:start position:0% +Y from the father and they're gonna get +1x from their mother so all the males + + align:start position:0% +1x from their mother so all the males + + + align:start position:0% +1x from their mother so all the males +are gonna be of this genotype here + + align:start position:0% +are gonna be of this genotype here + + + align:start position:0% +are gonna be of this genotype here +which means they're gonna have what + + align:start position:0% +which means they're gonna have what + + + align:start position:0% +which means they're gonna have what +color I Xavier is exactly right that + + align:start position:0% +color I Xavier is exactly right that + + + align:start position:0% +color I Xavier is exactly right that +means they're gonna have white eyes + + align:start position:0% +means they're gonna have white eyes + + + align:start position:0% +means they're gonna have white eyes +right so all the males will have white + + align:start position:0% +right so all the males will have white + + + align:start position:0% +right so all the males will have white +eyes and what about the females what's + + align:start position:0% +eyes and what about the females what's + + + align:start position:0% +eyes and what about the females what's +that yeah so Ori is saying the males are + + align:start position:0% +that yeah so Ori is saying the males are + + + align:start position:0% +that yeah so Ori is saying the males are +gonna get red eyes right because they're + + align:start position:0% +gonna get red eyes right because they're + + + align:start position:0% +gonna get red eyes right because they're +gay or the females are gonna have red + + align:start position:0% +gay or the females are gonna have red + + + align:start position:0% +gay or the females are gonna have red +eyes because they're gonna get the X + + align:start position:0% +eyes because they're gonna get the X + + + align:start position:0% +eyes because they're gonna get the X +chromosome from their father which has + + align:start position:0% +chromosome from their father which has + + + align:start position:0% +chromosome from their father which has +the dominant gene that produces the red + + align:start position:0% +the dominant gene that produces the red + + + align:start position:0% +the dominant gene that produces the red +pigment right so all the females are + + align:start position:0% +pigment right so all the females are + + + align:start position:0% +pigment right so all the females are +gonna be heterozygous but have a + + align:start position:0% +gonna be heterozygous but have a + + + align:start position:0% +gonna be heterozygous but have a +functional copy of this gene so all of + + align:start position:0% +functional copy of this gene so all of + + + align:start position:0% +functional copy of this gene so all of +the females will have red eyes okay does + + align:start position:0% +the females will have red eyes okay does + + + align:start position:0% +the females will have red eyes okay does +everyone see how now how would this + + align:start position:0% +everyone see how now how would this + + + align:start position:0% +everyone see how now how would this +compare with Mendel's crosses and like + + align:start position:0% +compare with Mendel's crosses and like + + + align:start position:0% +compare with Mendel's crosses and like +pea color would there be a difference in + + align:start position:0% +pea color would there be a difference in + + + align:start position:0% +pea color would there be a difference in +Mendel's cross crosses if you switch the + + align:start position:0% +Mendel's cross crosses if you switch the + + + align:start position:0% +Mendel's cross crosses if you switch the +male versus the female if these were + + align:start position:0% +male versus the female if these were + + + align:start position:0% +male versus the female if these were +autosomal traits or is shaking his head + + align:start position:0% +autosomal traits or is shaking his head + + + align:start position:0% +autosomal traits or is shaking his head +no and he's right right in that case it + + align:start position:0% +no and he's right right in that case it + + + align:start position:0% +no and he's right right in that case it +doesn't matter you can do the reciprocal + + align:start position:0% +doesn't matter you can do the reciprocal + + + align:start position:0% +doesn't matter you can do the reciprocal +crosses you get the same result but + + align:start position:0% +crosses you get the same result but + + + align:start position:0% +crosses you get the same result but +because this is sick sex linked what + + align:start position:0% +because this is sick sex linked what + + + align:start position:0% +because this is sick sex linked what +which one is the male and which is the + + align:start position:0% +which one is the male and which is the + + + align:start position:0% +which one is the male and which is the +female is relevant okay and this + + align:start position:0% +female is relevant okay and this + + + align:start position:0% +female is relevant okay and this +actually relates to something that I we + + align:start position:0% +actually relates to something that I we + + + align:start position:0% +actually relates to something that I we +just saw on the MIT news that I've just + + align:start position:0% +just saw on the MIT news that I've just + + + align:start position:0% +just saw on the MIT news that I've just +got this email this morning but it came + + align:start position:0% +got this email this morning but it came + + + align:start position:0% +got this email this morning but it came +out I think yesterday which is that + + align:start position:0% +out I think yesterday which is that + + + align:start position:0% +out I think yesterday which is that +biology related research in the + + align:start position:0% +biology related research in the + + + align:start position:0% +biology related research in the +mechanical engineering department + + align:start position:0% +mechanical engineering department + + + align:start position:0% +mechanical engineering department +specifically the chem lab they've been + + align:start position:0% +specifically the chem lab they've been + + + align:start position:0% +specifically the chem lab they've been +able to design a 3d sort of model for + + align:start position:0% +able to design a 3d sort of model for + + + align:start position:0% +able to design a 3d sort of model for +ALS disease which is also known as Lou + + align:start position:0% +ALS disease which is also known as Lou + + + align:start position:0% +ALS disease which is also known as Lou +Gehrig's disease and so what they've + + align:start position:0% +Gehrig's disease and so what they've + + + align:start position:0% +Gehrig's disease and so what they've +done in the chem lab is to take + + align:start position:0% +done in the chem lab is to take + + + align:start position:0% +done in the chem lab is to take +cells from either patients that have ALS + + align:start position:0% +cells from either patients that have ALS + + + align:start position:0% +cells from either patients that have ALS +or from normal individuals and they coax + + align:start position:0% +or from normal individuals and they coax + + + align:start position:0% +or from normal individuals and they coax +these cells to become neurons here + + align:start position:0% +these cells to become neurons here + + + align:start position:0% +these cells to become neurons here +you're seeing a neuron in blue and green + + align:start position:0% +you're seeing a neuron in blue and green + + + align:start position:0% +you're seeing a neuron in blue and green +here and you see this the neurites + + align:start position:0% +here and you see this the neurites + + + align:start position:0% +here and you see this the neurites +extend from this neuron and they have a + + align:start position:0% +extend from this neuron and they have a + + + align:start position:0% +extend from this neuron and they have a +model where this neuron can then synapse + + align:start position:0% +model where this neuron can then synapse + + + align:start position:0% +model where this neuron can then synapse +with a muscle and so they're using this + + align:start position:0% +with a muscle and so they're using this + + + align:start position:0% +with a muscle and so they're using this +3d sort of tissue model to model ALS and + + align:start position:0% +3d sort of tissue model to model ALS and + + + align:start position:0% +3d sort of tissue model to model ALS and +to look for drugs that might affect ALS + + align:start position:0% +to look for drugs that might affect ALS + + + align:start position:0% +to look for drugs that might affect ALS +potentially curing ALS okay and so last + + align:start position:0% +potentially curing ALS okay and so last + + + align:start position:0% +potentially curing ALS okay and so last +night I started reading about ALS and + + align:start position:0% +night I started reading about ALS and + + + align:start position:0% +night I started reading about ALS and +was pleased to find that there's + + align:start position:0% +was pleased to find that there's + + + align:start position:0% +was pleased to find that there's +actually a very there's a very rare + + align:start position:0% +actually a very there's a very rare + + + align:start position:0% +actually a very there's a very rare +x-linked dominant form of the disease + + align:start position:0% +x-linked dominant form of the disease + + + align:start position:0% +x-linked dominant form of the disease +that can be passed on from generation to + + align:start position:0% +that can be passed on from generation to + + + align:start position:0% +that can be passed on from generation to +generation + + align:start position:0% +generation + + + align:start position:0% +generation +and the inheritance pattern of this + + align:start position:0% +and the inheritance pattern of this + + + align:start position:0% +and the inheritance pattern of this +x-linked dominant version of ALS would + + align:start position:0% +x-linked dominant version of ALS would + + + align:start position:0% +x-linked dominant version of ALS would +have an inheritance pattern that's + + align:start position:0% +have an inheritance pattern that's + + + align:start position:0% +have an inheritance pattern that's +similar to what we observe for the white + + align:start position:0% +similar to what we observe for the white + + + align:start position:0% +similar to what we observe for the white +mutant in the fruit fly right whereas if + + align:start position:0% +mutant in the fruit fly right whereas if + + + align:start position:0% +mutant in the fruit fly right whereas if +you have an affected father that's and + + align:start position:0% +you have an affected father that's and + + + align:start position:0% +you have an affected father that's and +this is a dominant mutant on the X + + align:start position:0% +this is a dominant mutant on the X + + + align:start position:0% +this is a dominant mutant on the X +chromosome then all of his daughter's + + align:start position:0% +chromosome then all of his daughter's + + + align:start position:0% +chromosome then all of his daughter's +will get that X chromosome and be + + align:start position:0% +will get that X chromosome and be + + + align:start position:0% +will get that X chromosome and be +affected whereas the sons will all be + + align:start position:0% +affected whereas the sons will all be + + + align:start position:0% +affected whereas the sons will all be +unaffected however if you have the + + align:start position:0% +unaffected however if you have the + + + align:start position:0% +unaffected however if you have the +reciprocal situation where you have an + + align:start position:0% +reciprocal situation where you have an + + + align:start position:0% +reciprocal situation where you have an +affected mother and an unaffected father + + align:start position:0% +affected mother and an unaffected father + + + align:start position:0% +affected mother and an unaffected father +then the sons and daughters get the + + align:start position:0% +then the sons and daughters get the + + + align:start position:0% +then the sons and daughters get the +disease randomly okay so this is a sort + + align:start position:0% +disease randomly okay so this is a sort + + + align:start position:0% +disease randomly okay so this is a sort +of form of inheritance which is relevant + + align:start position:0% +of form of inheritance which is relevant + + + align:start position:0% +of form of inheritance which is relevant +if you're considering human disease and + + align:start position:0% +if you're considering human disease and + + + align:start position:0% +if you're considering human disease and +some forms of it most versions of ALS + + align:start position:0% +some forms of it most versions of ALS + + + align:start position:0% +some forms of it most versions of ALS +while are sporadic but the inherited + + align:start position:0% +while are sporadic but the inherited + + + align:start position:0% +while are sporadic but the inherited +forms are usually autosomal dominant so + + align:start position:0% +forms are usually autosomal dominant so + + + align:start position:0% +forms are usually autosomal dominant so +this is a rare case here but I thought + + align:start position:0% +this is a rare case here but I thought + + + align:start position:0% +this is a rare case here but I thought +it was interesting in that it's relevant + + align:start position:0% +it was interesting in that it's relevant + + + align:start position:0% +it was interesting in that it's relevant +to what we've been talking about okay so + + align:start position:0% +to what we've been talking about okay so + + + align:start position:0% +to what we've been talking about okay so +now just to recap here I'll throw this + + align:start position:0% +now just to recap here I'll throw this + + + align:start position:0% +now just to recap here I'll throw this +up so everything's up + + align:start position:0% + + + + align:start position:0% + +so in the last lecture we talked about + + align:start position:0% +so in the last lecture we talked about + + + align:start position:0% +so in the last lecture we talked about +Mendelian inheritance and we talked + + align:start position:0% +Mendelian inheritance and we talked + + + align:start position:0% +Mendelian inheritance and we talked +about when you take two parents that + + align:start position:0% +about when you take two parents that + + + align:start position:0% +about when you take two parents that +differ and two traits and you perform a + + align:start position:0% +differ and two traits and you perform a + + + align:start position:0% +differ and two traits and you perform a +cross you get a hybrid individual that + + align:start position:0% +cross you get a hybrid individual that + + + align:start position:0% +cross you get a hybrid individual that +is heterozygous for both genes and now + + align:start position:0% +is heterozygous for both genes and now + + + align:start position:0% +is heterozygous for both genes and now +this is the f1 individual let's say we + + align:start position:0% +this is the f1 individual let's say we + + + align:start position:0% +this is the f1 individual let's say we +want to know what types of gametes this + + align:start position:0% +want to know what types of gametes this + + + align:start position:0% +want to know what types of gametes this +f1 individual individual produces we can + + align:start position:0% +f1 individual individual produces we can + + + align:start position:0% +f1 individual individual produces we can +form we can perform a type of a cross + + align:start position:0% +form we can perform a type of a cross + + + align:start position:0% +form we can perform a type of a cross +known as a test cross where we cross + + align:start position:0% +known as a test cross where we cross + + + align:start position:0% +known as a test cross where we cross +this individual to another individual + + align:start position:0% +this individual to another individual + + + align:start position:0% +this individual to another individual +that is homozygous recessive for both + + align:start position:0% +that is homozygous recessive for both + + + align:start position:0% +that is homozygous recessive for both +these genes which means that you know + + align:start position:0% +these genes which means that you know + + + align:start position:0% +these genes which means that you know +exactly which alleles are coming from + + align:start position:0% +exactly which alleles are coming from + + + align:start position:0% +exactly which alleles are coming from +this parent and they're both recessive + + align:start position:0% +this parent and they're both recessive + + + align:start position:0% +this parent and they're both recessive +so you can see whether or not the gamete + + align:start position:0% +so you can see whether or not the gamete + + + align:start position:0% +so you can see whether or not the gamete +produced by this individual has either + + align:start position:0% +produced by this individual has either + + + align:start position:0% +produced by this individual has either +the dominant or the recessive allele + + align:start position:0% +the dominant or the recessive allele + + + align:start position:0% +the dominant or the recessive allele +okay so this up + + align:start position:0% + + + + align:start position:0% + +okay so now we can consider the + + align:start position:0% +okay so now we can consider the + + + align:start position:0% +okay so now we can consider the +different types of progeny that results + + align:start position:0% +different types of progeny that results + + + align:start position:0% +different types of progeny that results +from this test cross and some will have + + align:start position:0% +from this test cross and some will have + + + align:start position:0% +from this test cross and some will have +the two dominant alleles from this + + align:start position:0% +the two dominant alleles from this + + + align:start position:0% +the two dominant alleles from this +parent and will therefore be + + align:start position:0% +parent and will therefore be + + + align:start position:0% +parent and will therefore be +heterozygous for the a and B gene and it + + align:start position:0% +heterozygous for the a and B gene and it + + + align:start position:0% +heterozygous for the a and B gene and it +would exhibit the dominant a and B + + align:start position:0% +would exhibit the dominant a and B + + + align:start position:0% +would exhibit the dominant a and B +phenotype and I think that is what I'm + + align:start position:0% +phenotype and I think that is what I'm + + + align:start position:0% +phenotype and I think that is what I'm +showing here so if the chromosomes + + align:start position:0% +showing here so if the chromosomes + + + align:start position:0% +showing here so if the chromosomes +during meiosis one align like this then + + align:start position:0% +during meiosis one align like this then + + + align:start position:0% +during meiosis one align like this then +the two dominant alleles segregate + + align:start position:0% +the two dominant alleles segregate + + + align:start position:0% +the two dominant alleles segregate +together and you get a B gametes and on + + align:start position:0% +together and you get a B gametes and on + + + align:start position:0% +together and you get a B gametes and on +the you also reciprocally get these + + align:start position:0% +the you also reciprocally get these + + + align:start position:0% +the you also reciprocally get these +lowercase a and B gametes as well so + + align:start position:0% +lowercase a and B gametes as well so + + + align:start position:0% +lowercase a and B gametes as well so +that's the other class here so you can + + align:start position:0% +that's the other class here so you can + + + align:start position:0% +that's the other class here so you can +get these two these two classes of + + align:start position:0% +get these two these two classes of + + + align:start position:0% +get these two these two classes of +progeny and the phenotypes of these two + + align:start position:0% +progeny and the phenotypes of these two + + + align:start position:0% +progeny and the phenotypes of these two +classes will be resemble the parents + + align:start position:0% +classes will be resemble the parents + + + align:start position:0% +classes will be resemble the parents +right so these are known as parental + + align:start position:0% +right so these are known as parental + + + align:start position:0% +right so these are known as parental +gametes so these are the parentals okay + + align:start position:0% +gametes so these are the parentals okay + + + align:start position:0% +gametes so these are the parentals okay +but you know because Mendel showed that + + align:start position:0% +but you know because Mendel showed that + + + align:start position:0% +but you know because Mendel showed that +if you have genes and their alleles on + + align:start position:0% +if you have genes and their alleles on + + + align:start position:0% +if you have genes and their alleles on +separate chromosomes they can assort + + align:start position:0% +separate chromosomes they can assort + + + align:start position:0% +separate chromosomes they can assort +independently of each other + + align:start position:0% +independently of each other + + + align:start position:0% +independently of each other +so an alternative alternative an + + align:start position:0% +so an alternative alternative an + + + align:start position:0% +so an alternative alternative an +alternative Li likely scenario is that + + align:start position:0% +alternative Li likely scenario is that + + + align:start position:0% +alternative Li likely scenario is that +the chromosomes aligned like this where + + align:start position:0% +the chromosomes aligned like this where + + + align:start position:0% +the chromosomes aligned like this where +now the dominant allele of B is on the + + align:start position:0% +now the dominant allele of B is on the + + + align:start position:0% +now the dominant allele of B is on the +other side of the spindle and therefore + + align:start position:0% +other side of the spindle and therefore + + + align:start position:0% +other side of the spindle and therefore +these chromosomes are going to segregate + + align:start position:0% +these chromosomes are going to segregate + + + align:start position:0% +these chromosomes are going to segregate +like this during the first meiotic + + align:start position:0% +like this during the first meiotic + + + align:start position:0% +like this during the first meiotic +division and that gives rise to gametes + + align:start position:0% +division and that gives rise to gametes + + + align:start position:0% +division and that gives rise to gametes +that have a different combination of + + align:start position:0% +that have a different combination of + + + align:start position:0% +that have a different combination of +alleles than the parents okay so you + + align:start position:0% +alleles than the parents okay so you + + + align:start position:0% +alleles than the parents okay so you +have some look like this + + align:start position:0% + + + + align:start position:0% + +so each of these would be different + + align:start position:0% +so each of these would be different + + + align:start position:0% +so each of these would be different +classes of progeny and you have one last + + align:start position:0% +classes of progeny and you have one last + + + align:start position:0% +classes of progeny and you have one last +class that would look like this okay and + + align:start position:0% +class that would look like this okay and + + + align:start position:0% +class that would look like this okay and +so neither of these look like the + + align:start position:0% +so neither of these look like the + + + align:start position:0% +so neither of these look like the +original parents and so they're known as + + align:start position:0% +original parents and so they're known as + + + align:start position:0% +original parents and so they're known as +non parental and so if these two genes + + align:start position:0% +non parental and so if these two genes + + + align:start position:0% +non parental and so if these two genes +are behaving according to Mendel's + + align:start position:0% +are behaving according to Mendel's + + + align:start position:0% +are behaving according to Mendel's +second law where there's independent + + align:start position:0% +second law where there's independent + + + align:start position:0% +second law where there's independent +assortment if you have independent + + align:start position:0% +assortment if you have independent + + + align:start position:0% +assortment if you have independent +assortment what's going to be the ratio + + align:start position:0% +assortment what's going to be the ratio + + + align:start position:0% +assortment what's going to be the ratio +of parental to non parental yeah Rachel + + align:start position:0% +of parental to non parental yeah Rachel + + + align:start position:0% +of parental to non parental yeah Rachel +yeah Rachel says one to one and I think + + align:start position:0% +yeah Rachel says one to one and I think + + + align:start position:0% +yeah Rachel says one to one and I think +a number of others also said one to one + + align:start position:0% +a number of others also said one to one + + + align:start position:0% +a number of others also said one to one +so you have 50% parental 50% non + + align:start position:0% +so you have 50% parental 50% non + + + align:start position:0% +so you have 50% parental 50% non +parental right because it's equally + + align:start position:0% +parental right because it's equally + + + align:start position:0% +parental right because it's equally +likely to get either of those alignments + + align:start position:0% +likely to get either of those alignments + + + align:start position:0% +likely to get either of those alignments +of the homologous chromosomes during + + align:start position:0% +of the homologous chromosomes during + + + align:start position:0% +of the homologous chromosomes during +meiosis one okay so now I'm gonna + + align:start position:0% +meiosis one okay so now I'm gonna + + + align:start position:0% +meiosis one okay so now I'm gonna +basically break the rules I just + + align:start position:0% +basically break the rules I just + + + align:start position:0% +basically break the rules I just +explained to you in the last lecture and + + align:start position:0% +explained to you in the last lecture and + + + align:start position:0% +explained to you in the last lecture and +tell you about an exception which is + + align:start position:0% +tell you about an exception which is + + + align:start position:0% +tell you about an exception which is +known as linkage because in tight and in + + align:start position:0% +known as linkage because in tight and in + + + align:start position:0% +known as linkage because in tight and in +the in the abstract sense linkage is + + align:start position:0% +the in the abstract sense linkage is + + + align:start position:0% +the in the abstract sense linkage is +simply when you have two traits that + + align:start position:0% +simply when you have two traits that + + + align:start position:0% +simply when you have two traits that +tend to be inherited together + + align:start position:0% +tend to be inherited together + + + align:start position:0% +tend to be inherited together +okay so just considering probability so + + align:start position:0% +okay so just considering probability so + + + align:start position:0% +okay so just considering probability so +there you have traits inherited together + + align:start position:0% +there you have traits inherited together + + + align:start position:0% +there you have traits inherited together +they're exhibiting what is known as + + align:start position:0% +they're exhibiting what is known as + + + align:start position:0% +they're exhibiting what is known as +linkage okay but that's an abstract way + + align:start position:0% +linkage okay but that's an abstract way + + + align:start position:0% +linkage okay but that's an abstract way +to think about it it's just based on + + align:start position:0% +to think about it it's just based on + + + align:start position:0% +to think about it it's just based on +probability right so a physical model + + align:start position:0% +probability right so a physical model + + + align:start position:0% +probability right so a physical model +for what linkage is is that you have + + align:start position:0% +for what linkage is is that you have + + + align:start position:0% +for what linkage is is that you have +chromosomes the genes are on the + + align:start position:0% +chromosomes the genes are on the + + + align:start position:0% +chromosomes the genes are on the +chromosomes and it for two genes to be + + align:start position:0% +chromosomes and it for two genes to be + + + align:start position:0% +chromosomes and it for two genes to be +linked those genes are physically near + + align:start position:0% +linked those genes are physically near + + + align:start position:0% +linked those genes are physically near +each other on the chromosome okay so the + + align:start position:0% +each other on the chromosome okay so the + + + align:start position:0% +each other on the chromosome okay so the +physical model is that genes two genes + + align:start position:0% +physical model is that genes two genes + + + align:start position:0% +physical model is that genes two genes +are near each other on the chromosome + + align:start position:0% + + + + align:start position:0% + +okay so let's consider again these + + align:start position:0% +okay so let's consider again these + + + align:start position:0% +okay so let's consider again these +generic genes a and B if a and B + + align:start position:0% +generic genes a and B if a and B + + + align:start position:0% +generic genes a and B if a and B +resulting from this cross if these two + + align:start position:0% +resulting from this cross if these two + + + align:start position:0% +resulting from this cross if these two +happen to be on the same chromosome now + + align:start position:0% +happen to be on the same chromosome now + + + align:start position:0% +happen to be on the same chromosome now +they're physically coupled to each other + + align:start position:0% +they're physically coupled to each other + + + align:start position:0% +they're physically coupled to each other +then they're gonna tend to be inherited + + align:start position:0% +then they're gonna tend to be inherited + + + align:start position:0% +then they're gonna tend to be inherited +together right so they're always no + + align:start position:0% +together right so they're always no + + + align:start position:0% +together right so they're always no +matter how those these align they're + + align:start position:0% +matter how those these align they're + + + align:start position:0% +matter how those these align they're +always gonna go together during the + + align:start position:0% +always gonna go together during the + + + align:start position:0% +always gonna go together during the +first meiotic division and that's just + + align:start position:0% +first meiotic division and that's just + + + align:start position:0% +first meiotic division and that's just +going to only give you the parental + + align:start position:0% +going to only give you the parental + + + align:start position:0% +going to only give you the parental +gametes okay so if there's linkage + + align:start position:0% +gametes okay so if there's linkage + + + align:start position:0% +gametes okay so if there's linkage +you're gonna have let's let's consider + + align:start position:0% +you're gonna have let's let's consider + + + align:start position:0% +you're gonna have let's let's consider +the case where you have complete linkage + + align:start position:0% + + + + align:start position:0% + +if you have complete linkage a hundred + + align:start position:0% +if you have complete linkage a hundred + + + align:start position:0% +if you have complete linkage a hundred +percent of the gametes are going to be + + align:start position:0% +percent of the gametes are going to be + + + align:start position:0% +percent of the gametes are going to be +parentals and you're gonna have zero + + align:start position:0% +parentals and you're gonna have zero + + + align:start position:0% +parentals and you're gonna have zero +percent non-parental okay that's if you + + align:start position:0% +percent non-parental okay that's if you + + + align:start position:0% +percent non-parental okay that's if you +have that's if the genes are really + + align:start position:0% +have that's if the genes are really + + + align:start position:0% +have that's if the genes are really +really really close to each other and + + align:start position:0% +really really close to each other and + + + align:start position:0% +really really close to each other and +maybe you don't count so many progeny + + align:start position:0% +maybe you don't count so many progeny + + + align:start position:0% +maybe you don't count so many progeny +you won't see any mixing between the two + + align:start position:0% +you won't see any mixing between the two + + + align:start position:0% +you won't see any mixing between the two +okay but there's a phenomenon that can + + align:start position:0% +okay but there's a phenomenon that can + + + align:start position:0% +okay but there's a phenomenon that can +separate these genes and it's known as + + align:start position:0% +separate these genes and it's known as + + + align:start position:0% +separate these genes and it's known as +crossing over and another term to + + align:start position:0% +crossing over and another term to + + + align:start position:0% +crossing over and another term to +describe it is recombination so the + + align:start position:0% +describe it is recombination so the + + + align:start position:0% +describe it is recombination so the +alleles are getting recombined between + + align:start position:0% +alleles are getting recombined between + + + align:start position:0% +alleles are getting recombined between +the chromosomes recombination and what + + align:start position:0% +the chromosomes recombination and what + + + align:start position:0% +the chromosomes recombination and what +crossing over or recombination it is is + + align:start position:0% +crossing over or recombination it is is + + + align:start position:0% +crossing over or recombination it is is +it's a mixing of the chromosomes if you + + align:start position:0% +it's a mixing of the chromosomes if you + + + align:start position:0% +it's a mixing of the chromosomes if you +will or you could it's an exchange of + + align:start position:0% +will or you could it's an exchange of + + + align:start position:0% +will or you could it's an exchange of +DNA so there's a physical exchange of + + align:start position:0% +DNA so there's a physical exchange of + + + align:start position:0% +DNA so there's a physical exchange of +DNA from one of the homologous + + align:start position:0% +DNA from one of the homologous + + + align:start position:0% +DNA from one of the homologous +chromosomes to the other okay so you can + + align:start position:0% +chromosomes to the other okay so you can + + + align:start position:0% +chromosomes to the other okay so you can +think of this as an exchange of DNA + + align:start position:0% + + + + align:start position:0% + +between the homologous chromosomes okay + + align:start position:0% +between the homologous chromosomes okay + + + align:start position:0% +between the homologous chromosomes okay +and that's important it's not it's + + align:start position:0% +and that's important it's not it's + + + align:start position:0% +and that's important it's not it's +exchange between the sister chromatids + + align:start position:0% +exchange between the sister chromatids + + + align:start position:0% +exchange between the sister chromatids +but between the homologous chromosomes + + align:start position:0% +but between the homologous chromosomes + + + align:start position:0% +but between the homologous chromosomes +that have the different alleles + + align:start position:0% + + + + align:start position:0% + +okay and what's shown here is a + + align:start position:0% +okay and what's shown here is a + + + align:start position:0% +okay and what's shown here is a +micrograph showing you a picture of the + + align:start position:0% +micrograph showing you a picture of the + + + align:start position:0% +micrograph showing you a picture of the +process of crossing over you can see the + + align:start position:0% +process of crossing over you can see the + + + align:start position:0% +process of crossing over you can see the +centromeres are the dark structures + + align:start position:0% +centromeres are the dark structures + + + align:start position:0% +centromeres are the dark structures +there and you can see how the homologous + + align:start position:0% +there and you can see how the homologous + + + align:start position:0% +there and you can see how the homologous +chromosomes intertwine and there are + + align:start position:0% +chromosomes intertwine and there are + + + align:start position:0% +chromosomes intertwine and there are +regions where there looks like there's a + + align:start position:0% +regions where there looks like there's a + + + align:start position:0% +regions where there looks like there's a +cross okay those are the homologous + + align:start position:0% +cross okay those are the homologous + + + align:start position:0% +cross okay those are the homologous +chromosomes crossing over and exchanging + + align:start position:0% +chromosomes crossing over and exchanging + + + align:start position:0% +chromosomes crossing over and exchanging +DNA such that one part of that + + align:start position:0% +DNA such that one part of that + + + align:start position:0% +DNA such that one part of that +chromosome gets attached to the other + + align:start position:0% +chromosome gets attached to the other + + + align:start position:0% +chromosome gets attached to the other +centromere okay + + align:start position:0% +centromere okay + + + align:start position:0% +centromere okay +so I'll just show you in sort of my + + align:start position:0% +so I'll just show you in sort of my + + + align:start position:0% +so I'll just show you in sort of my +silly cartoon form how this is just to + + align:start position:0% +silly cartoon form how this is just to + + + align:start position:0% +silly cartoon form how this is just to +make it clear so let's say again you + + align:start position:0% +make it clear so let's say again you + + + align:start position:0% +make it clear so let's say again you +have these a and B genes and they're + + align:start position:0% +have these a and B genes and they're + + + align:start position:0% +have these a and B genes and they're +physically linked on the chromosome + + align:start position:0% +physically linked on the chromosome + + + align:start position:0% +physically linked on the chromosome +during crossing over you can get an + + align:start position:0% +during crossing over you can get an + + + align:start position:0% +during crossing over you can get an +exchange of these alleles such as a bit + + align:start position:0% +exchange of these alleles such as a bit + + + align:start position:0% +exchange of these alleles such as a bit +of one chromosome goes to the other + + align:start position:0% +of one chromosome goes to the other + + + align:start position:0% +of one chromosome goes to the other +homologous chromosome and vice versa + + align:start position:0% +homologous chromosome and vice versa + + + align:start position:0% +homologous chromosome and vice versa +okay so now you have the dominant a + + align:start position:0% +okay so now you have the dominant a + + + align:start position:0% +okay so now you have the dominant a +allele with the recessive B allele and + + align:start position:0% +allele with the recessive B allele and + + + align:start position:0% +allele with the recessive B allele and +vice versa so now during meiosis one + + align:start position:0% +vice versa so now during meiosis one + + + align:start position:0% +vice versa so now during meiosis one +after meiosis two this will give rise to + + align:start position:0% +after meiosis two this will give rise to + + + align:start position:0% +after meiosis two this will give rise to +two types of gametes one of which is non + + align:start position:0% +two types of gametes one of which is non + + + align:start position:0% +two types of gametes one of which is non +parental and the same the same for the + + align:start position:0% +parental and the same the same for the + + + align:start position:0% +parental and the same the same for the +one down here you get two types of + + align:start position:0% +one down here you get two types of + + + align:start position:0% +one down here you get two types of +gametes one is non parental the + + align:start position:0% +gametes one is non parental the + + + align:start position:0% +gametes one is non parental the +lowercase a uppercase B gamete okay so + + align:start position:0% +lowercase a uppercase B gamete okay so + + + align:start position:0% +lowercase a uppercase B gamete okay so +this happens if there's incomplete + + align:start position:0% +this happens if there's incomplete + + + align:start position:0% +this happens if there's incomplete +linkage that means there can be a + + align:start position:0% +linkage that means there can be a + + + align:start position:0% +linkage that means there can be a +recombination event that separates the + + align:start position:0% +recombination event that separates the + + + align:start position:0% +recombination event that separates the +two genes and I'm going to give you an + + align:start position:0% +two genes and I'm going to give you an + + + align:start position:0% +two genes and I'm going to give you an +an example of a case where data was + + align:start position:0% +an example of a case where data was + + + align:start position:0% +an example of a case where data was +collected with what fraction of each + + align:start position:0% +collected with what fraction of each + + + align:start position:0% +collected with what fraction of each +class there is so now we're considering + + align:start position:0% +class there is so now we're considering + + + align:start position:0% +class there is so now we're considering +the example where you have a linkage so + + align:start position:0% +the example where you have a linkage so + + + align:start position:0% +the example where you have a linkage so +that chromosome a and B are on the same + + align:start position:0% +that chromosome a and B are on the same + + + align:start position:0% +that chromosome a and B are on the same +chromosome and so we'll consider a case + + align:start position:0% +chromosome and so we'll consider a case + + + align:start position:0% +chromosome and so we'll consider a case +where in this class there are 165 + + align:start position:0% +where in this class there are 165 + + + align:start position:0% +where in this class there are 165 +members for this one there's 191 so I'm + + align:start position:0% +members for this one there's 191 so I'm + + + align:start position:0% +members for this one there's 191 so I'm +coming + + align:start position:0% +coming + + + align:start position:0% +coming +this and then for the first recombinant + + align:start position:0% +this and then for the first recombinant + + + align:start position:0% +this and then for the first recombinant +class 23 individuals and for the last + + align:start position:0% +class 23 individuals and for the last + + + align:start position:0% +class 23 individuals and for the last +there are 21 individuals okay so you can + + align:start position:0% +there are 21 individuals okay so you can + + + align:start position:0% +there are 21 individuals okay so you can +see there are many more of the parental + + align:start position:0% +see there are many more of the parental + + + align:start position:0% +see there are many more of the parental +class than the recombinant class but we + + align:start position:0% +class than the recombinant class but we + + + align:start position:0% +class than the recombinant class but we +can calculate a frequency or + + align:start position:0% +can calculate a frequency or + + + align:start position:0% +can calculate a frequency or +recombination frequency between these + + align:start position:0% +recombination frequency between these + + + align:start position:0% +recombination frequency between these +two genes and in this case the + + align:start position:0% +two genes and in this case the + + + align:start position:0% +two genes and in this case the +recombination frequency is 44 over 400 + + align:start position:0% +recombination frequency is 44 over 400 + + + align:start position:0% +recombination frequency is 44 over 400 +which is equal to 11 percent okay so 11 + + align:start position:0% +which is equal to 11 percent okay so 11 + + + align:start position:0% +which is equal to 11 percent okay so 11 +percent of the progeny from this cross + + align:start position:0% +percent of the progeny from this cross + + + align:start position:0% +percent of the progeny from this cross +had some sort of crossing over between + + align:start position:0% +had some sort of crossing over between + + + align:start position:0% +had some sort of crossing over between +the a and B alleles but it would have + + align:start position:0% +the a and B alleles but it would have + + + align:start position:0% +the a and B alleles but it would have +been up here okay now this this this + + align:start position:0% +been up here okay now this this this + + + align:start position:0% +been up here okay now this this this +frequency is interesting because it is + + align:start position:0% +frequency is interesting because it is + + + align:start position:0% +frequency is interesting because it is +proportional to the distance that + + align:start position:0% +proportional to the distance that + + + align:start position:0% +proportional to the distance that +separates these two genes okay so this + + align:start position:0% +separates these two genes okay so this + + + align:start position:0% +separates these two genes okay so this +recombination frequency is proportional + + align:start position:0% +recombination frequency is proportional + + + align:start position:0% +recombination frequency is proportional +to the linear distance between along the + + align:start position:0% +to the linear distance between along the + + + align:start position:0% +to the linear distance between along the +chromosome between the genes + + align:start position:0% + + + + align:start position:0% + +now it also depends on the recombination + + align:start position:0% +now it also depends on the recombination + + + align:start position:0% +now it also depends on the recombination +frequency in a given organism or in a + + align:start position:0% +frequency in a given organism or in a + + + align:start position:0% +frequency in a given organism or in a +given part part of the chromosome so + + align:start position:0% +given part part of the chromosome so + + + align:start position:0% +given part part of the chromosome so +when you're comparing recombination + + align:start position:0% +when you're comparing recombination + + + align:start position:0% +when you're comparing recombination +frequencies between different organisms + + align:start position:0% +frequencies between different organisms + + + align:start position:0% +frequencies between different organisms +there's actually differences in the real + + align:start position:0% +there's actually differences in the real + + + align:start position:0% +there's actually differences in the real +difference in the they're not equivalent + + align:start position:0% +difference in the they're not equivalent + + + align:start position:0% +difference in the they're not equivalent +you can't compare them basically and + + align:start position:0% +you can't compare them basically and + + + align:start position:0% +you can't compare them basically and +also there are regions of the chromosome + + align:start position:0% +also there are regions of the chromosome + + + align:start position:0% +also there are regions of the chromosome +where recombination happens less + + align:start position:0% +where recombination happens less + + + align:start position:0% +where recombination happens less +frequently than others and so again you + + align:start position:0% +frequently than others and so again you + + + align:start position:0% +frequently than others and so again you +can't compare distances along those but + + align:start position:0% +can't compare distances along those but + + + align:start position:0% +can't compare distances along those but +overall you can use this as a distance + + align:start position:0% +overall you can use this as a distance + + + align:start position:0% +overall you can use this as a distance +in order to map genes along the linear + + align:start position:0% +in order to map genes along the linear + + + align:start position:0% +in order to map genes along the linear +axis of a chromosome okay and maps are + + align:start position:0% +axis of a chromosome okay and maps are + + + align:start position:0% +axis of a chromosome okay and maps are +useful because you can see where stuff + + align:start position:0% +useful because you can see where stuff + + + align:start position:0% +useful because you can see where stuff +is right so in this example here so + + align:start position:0% +is right so in this example here so + + + align:start position:0% +is right so in this example here so +highlight a couple places here's + + align:start position:0% +highlight a couple places here's + + + align:start position:0% +highlight a couple places here's +Rivendell here's Lonely Mountain + + align:start position:0% +Rivendell here's Lonely Mountain + + + align:start position:0% +Rivendell here's Lonely Mountain +here's Bay orange house so let's say we + + align:start position:0% +here's Bay orange house so let's say we + + + align:start position:0% +here's Bay orange house so let's say we +are able to determine the distance + + align:start position:0% +are able to determine the distance + + + align:start position:0% +are able to determine the distance +between Rivendell and Lonely Mountain + + align:start position:0% +between Rivendell and Lonely Mountain + + + align:start position:0% +between Rivendell and Lonely Mountain +and the distance between Lonely Mountain + + align:start position:0% +and the distance between Lonely Mountain + + + align:start position:0% +and the distance between Lonely Mountain +and valence house and the distance + + align:start position:0% +and valence house and the distance + + + align:start position:0% +and valence house and the distance +between Rivendell and Bay or Ann's house + + align:start position:0% +between Rivendell and Bay or Ann's house + + + align:start position:0% +between Rivendell and Bay or Ann's house +you'd be able to get a relative picture + + align:start position:0% +you'd be able to get a relative picture + + + align:start position:0% +you'd be able to get a relative picture +of where all of these places are in + + align:start position:0% +of where all of these places are in + + + align:start position:0% +of where all of these places are in +relation to each other okay so this is a + + align:start position:0% +relation to each other okay so this is a + + + align:start position:0% +relation to each other okay so this is a +two dimensional map I'm showing here + + align:start position:0% +two dimensional map I'm showing here + + + align:start position:0% +two dimensional map I'm showing here +it's not one dimensional but chromosomes + + align:start position:0% +it's not one dimensional but chromosomes + + + align:start position:0% +it's not one dimensional but chromosomes +are one dimensional so it's a bit more + + align:start position:0% +are one dimensional so it's a bit more + + + align:start position:0% +are one dimensional so it's a bit more +accurate okay so this this idea that + + align:start position:0% +accurate okay so this this idea that + + + align:start position:0% +accurate okay so this this idea that +recombination frequency can be used to + + align:start position:0% +recombination frequency can be used to + + + align:start position:0% +recombination frequency can be used to +measure distances between genes and that + + align:start position:0% +measure distances between genes and that + + + align:start position:0% +measure distances between genes and that +this could be used to generate a map is + + align:start position:0% +this could be used to generate a map is + + + align:start position:0% +this could be used to generate a map is +an idea that an undergraduate had while + + align:start position:0% +an idea that an undergraduate had while + + + align:start position:0% +an idea that an undergraduate had while +working in Thomas Hunt Morgan slab back + + align:start position:0% +working in Thomas Hunt Morgan slab back + + + align:start position:0% +working in Thomas Hunt Morgan slab back +in 1911 and what I find fascinating + + align:start position:0% +in 1911 and what I find fascinating + + + align:start position:0% +in 1911 and what I find fascinating +about the story is this guy basically + + align:start position:0% +about the story is this guy basically + + + align:start position:0% +about the story is this guy basically +blew off his homework to produce the + + align:start position:0% +blew off his homework to produce the + + + align:start position:0% +blew off his homework to produce the +first genetic map in any organism okay + + align:start position:0% +first genetic map in any organism okay + + + align:start position:0% +first genetic map in any organism okay +so the person who did it was Alfred + + align:start position:0% +so the person who did it was Alfred + + + align:start position:0% +so the person who did it was Alfred +Sturtevant and he was an undergraduate + + align:start position:0% +Sturtevant and he was an undergraduate + + + align:start position:0% +Sturtevant and he was an undergraduate +at Columbia working for Thomas Hunt + + align:start position:0% +at Columbia working for Thomas Hunt + + + align:start position:0% +at Columbia working for Thomas Hunt +Morgan + + align:start position:0% +Morgan + + + align:start position:0% +Morgan +and I'll just paraphrase this quote here + + align:start position:0% +and I'll just paraphrase this quote here + + + align:start position:0% +and I'll just paraphrase this quote here +in 1911 he was talking with his advisor + + align:start position:0% +in 1911 he was talking with his advisor + + + align:start position:0% +in 1911 he was talking with his advisor +Morgan and he realized that the + + align:start position:0% +Morgan and he realized that the + + + align:start position:0% +Morgan and he realized that the +variations in the strength of linkage + + align:start position:0% +variations in the strength of linkage + + + align:start position:0% +variations in the strength of linkage +attributed by Morgan to differences in + + align:start position:0% +attributed by Morgan to differences in + + + align:start position:0% +attributed by Morgan to differences in +the separation of genes right so Morgan + + align:start position:0% +the separation of genes right so Morgan + + + align:start position:0% +the separation of genes right so Morgan +had already made this connection that + + align:start position:0% +had already made this connection that + + + align:start position:0% +had already made this connection that +the recombination frequency reflects the + + align:start position:0% +the recombination frequency reflects the + + + align:start position:0% +the recombination frequency reflects the +distance between the genes but then + + align:start position:0% +distance between the genes but then + + + align:start position:0% +distance between the genes but then +Sturdivant realized that this offered + + align:start position:0% +Sturdivant realized that this offered + + + align:start position:0% +Sturdivant realized that this offered +the possibility of determining sequences + + align:start position:0% +the possibility of determining sequences + + + align:start position:0% +the possibility of determining sequences +in the linear dimension of the + + align:start position:0% +in the linear dimension of the + + + align:start position:0% +in the linear dimension of the +chromosome between the genes okay and so + + align:start position:0% +chromosome between the genes okay and so + + + align:start position:0% +chromosome between the genes okay and so +then this is my favorite part I went + + align:start position:0% +then this is my favorite part I went + + + align:start position:0% +then this is my favorite part I went +home and spent most of the night to the + + align:start position:0% +home and spent most of the night to the + + + align:start position:0% +home and spent most of the night to the +neglect of my undergraduate homework and + + align:start position:0% +neglect of my undergraduate homework and + + + align:start position:0% +neglect of my undergraduate homework and +producing the first chromosome map okay + + align:start position:0% +producing the first chromosome map okay + + + align:start position:0% +producing the first chromosome map okay +and this is it + + align:start position:0% +and this is it + + + align:start position:0% +and this is it +so the first chromosome map was of the + + align:start position:0% +so the first chromosome map was of the + + + align:start position:0% +so the first chromosome map was of the +Drosophila X chromosome which we've been + + align:start position:0% +Drosophila X chromosome which we've been + + + align:start position:0% +Drosophila X chromosome which we've been +talking about there's the white gene + + align:start position:0% +talking about there's the white gene + + + align:start position:0% +talking about there's the white gene +which we've been talking about in the + + align:start position:0% +which we've been talking about in the + + + align:start position:0% +which we've been talking about in the +context of eye color there's a yellow + + align:start position:0% +context of eye color there's a yellow + + + align:start position:0% +context of eye color there's a yellow +body gene here there's vermilion + + align:start position:0% +body gene here there's vermilion + + + align:start position:0% +body gene here there's vermilion +miniature rudimentary right these are + + align:start position:0% +miniature rudimentary right these are + + + align:start position:0% +miniature rudimentary right these are +all visible phenotypes that you can see + + align:start position:0% +all visible phenotypes that you can see + + + align:start position:0% +all visible phenotypes that you can see +in the fly and you can measure + + align:start position:0% +in the fly and you can measure + + + align:start position:0% +in the fly and you can measure +recombination between various alleles of + + align:start position:0% +recombination between various alleles of + + + align:start position:0% +recombination between various alleles of +these different genes all right so now I + + align:start position:0% +these different genes all right so now I + + + align:start position:0% +these different genes all right so now I +want to go through with you an example + + align:start position:0% +want to go through with you an example + + + align:start position:0% +want to go through with you an example +of how you can make one of these genetic + + align:start position:0% +of how you can make one of these genetic + + + align:start position:0% +of how you can make one of these genetic +maps and it's essentially the same + + align:start position:0% +maps and it's essentially the same + + + align:start position:0% +maps and it's essentially the same +conceptually as to what Sturdivant did + + align:start position:0% +conceptually as to what Sturdivant did + + + align:start position:0% +conceptually as to what Sturdivant did +and it involves what is known as a + + align:start position:0% +and it involves what is known as a + + + align:start position:0% +and it involves what is known as a +three-point cross so a three-point cross + + align:start position:0% + + + + align:start position:0% + +okay so they're gonna be three genes all + + align:start position:0% +okay so they're gonna be three genes all + + + align:start position:0% +okay so they're gonna be three genes all +of which are going to be hybrid and I'll + + align:start position:0% +of which are going to be hybrid and I'll + + + align:start position:0% +of which are going to be hybrid and I'll +start with a parental generation that is + + align:start position:0% +start with a parental generation that is + + + align:start position:0% +start with a parental generation that is +little a capital B capital D and we'll + + align:start position:0% +little a capital B capital D and we'll + + + align:start position:0% +little a capital B capital D and we'll +cross this fly or organism to an + + align:start position:0% +cross this fly or organism to an + + + align:start position:0% +cross this fly or organism to an +organism that is capital a lowercase B + + align:start position:0% +organism that is capital a lowercase B + + + align:start position:0% +organism that is capital a lowercase B +lowercase D okay yes + + align:start position:0% +lowercase D okay yes + + + align:start position:0% +lowercase D okay yes +Harmon + + align:start position:0% + + + + align:start position:0% + +so what I'm writing here is the + + align:start position:0% +so what I'm writing here is the + + + align:start position:0% +so what I'm writing here is the +phenotype basically and so these are + + align:start position:0% +phenotype basically and so these are + + + align:start position:0% +phenotype basically and so these are +homozygous for each of these yes mm-hmm + + align:start position:0% +homozygous for each of these yes mm-hmm + + + align:start position:0% +homozygous for each of these yes mm-hmm +so we're starting I could also write + + align:start position:0% +so we're starting I could also write + + + align:start position:0% +so we're starting I could also write +this as but I'm not going to draw the + + align:start position:0% +this as but I'm not going to draw the + + + align:start position:0% +this as but I'm not going to draw the +chromosomes because it's it kind of gets + + align:start position:0% +chromosomes because it's it kind of gets + + + align:start position:0% +chromosomes because it's it kind of gets +gets more confusing I'll just draw I'll + + align:start position:0% +gets more confusing I'll just draw I'll + + + align:start position:0% +gets more confusing I'll just draw I'll +draw the chromosomes here in the f1 + + align:start position:0% +draw the chromosomes here in the f1 + + + align:start position:0% +draw the chromosomes here in the f1 +because we haven't now basically a tri + + align:start position:0% +because we haven't now basically a tri + + + align:start position:0% +because we haven't now basically a tri +hybrid with run one chromosome that + + align:start position:0% +hybrid with run one chromosome that + + + align:start position:0% +hybrid with run one chromosome that +looks like this right they got that + + align:start position:0% +looks like this right they got that + + + align:start position:0% +looks like this right they got that +chromosome from this individual here and + + align:start position:0% +chromosome from this individual here and + + + align:start position:0% +chromosome from this individual here and +another chromosome will look like this + + align:start position:0% +another chromosome will look like this + + + align:start position:0% +another chromosome will look like this +okay see so so this f1 of fly is + + align:start position:0% +okay see so so this f1 of fly is + + + align:start position:0% +okay see so so this f1 of fly is +heterozygous for these three genes and + + align:start position:0% +heterozygous for these three genes and + + + align:start position:0% +heterozygous for these three genes and +it has these two parental chromosomes + + align:start position:0% +it has these two parental chromosomes + + + align:start position:0% +it has these two parental chromosomes +okay so now we can look at the gametes + + align:start position:0% +okay so now we can look at the gametes + + + align:start position:0% +okay so now we can look at the gametes +that result from this fly by doing a + + align:start position:0% +that result from this fly by doing a + + + align:start position:0% +that result from this fly by doing a +test cross just like we did before and + + align:start position:0% +test cross just like we did before and + + + align:start position:0% +test cross just like we did before and +so we want to cross this to a fly that's + + align:start position:0% +so we want to cross this to a fly that's + + + align:start position:0% +so we want to cross this to a fly that's +homozygous recessive for each of these + + align:start position:0% +homozygous recessive for each of these + + + align:start position:0% +homozygous recessive for each of these +genes and now we can look at the progeny + + align:start position:0% +genes and now we can look at the progeny + + + align:start position:0% +genes and now we can look at the progeny +and just by looking at the phenotype + + align:start position:0% +and just by looking at the phenotype + + + align:start position:0% +and just by looking at the phenotype +we're gonna know the genotype because we + + align:start position:0% +we're gonna know the genotype because we + + + align:start position:0% +we're gonna know the genotype because we +know all of the flies and from this + + align:start position:0% +know all of the flies and from this + + + align:start position:0% +know all of the flies and from this +cross have a chromosome from this + + align:start position:0% +cross have a chromosome from this + + + align:start position:0% +cross have a chromosome from this +individual that has recessive alleles + + align:start position:0% +individual that has recessive alleles + + + align:start position:0% +individual that has recessive alleles +for each gene so we can consider now + + align:start position:0% +for each gene so we can consider now + + + align:start position:0% +for each gene so we can consider now +this first one here that's one potential + + align:start position:0% +this first one here that's one potential + + + align:start position:0% +this first one here that's one potential +class of progeny another class would be + + align:start position:0% +class of progeny another class would be + + + align:start position:0% +class of progeny another class would be +this one and these two you can see + + align:start position:0% +this one and these two you can see + + + align:start position:0% +this one and these two you can see +resemble the parents right so these are + + align:start position:0% +resemble the parents right so these are + + + align:start position:0% +resemble the parents right so these are +the parental classes of the progeny so + + align:start position:0% +the parental classes of the progeny so + + + align:start position:0% +the parental classes of the progeny so +this is parental + + align:start position:0% + + + + align:start position:0% + +all right now you can consider all other + + align:start position:0% +all right now you can consider all other + + + align:start position:0% +all right now you can consider all other +combinations of alleles and so I'll just + + align:start position:0% +combinations of alleles and so I'll just + + + align:start position:0% +combinations of alleles and so I'll just +go I'll quickly write them down you + + align:start position:0% +go I'll quickly write them down you + + + align:start position:0% +go I'll quickly write them down you +could have something progeny that looked + + align:start position:0% +could have something progeny that looked + + + align:start position:0% +could have something progeny that looked +like this and this these are just kind + + align:start position:0% +like this and this these are just kind + + + align:start position:0% +like this and this these are just kind +of reciprocal from each other + + align:start position:0% +of reciprocal from each other + + + align:start position:0% +of reciprocal from each other +you could have progeny that look like + + align:start position:0% +you could have progeny that look like + + + align:start position:0% +you could have progeny that look like +this and this and the last class would + + align:start position:0% +this and this and the last class would + + + align:start position:0% +this and this and the last class would +be this and this okay so all of these + + align:start position:0% +be this and this okay so all of these + + + align:start position:0% +be this and this okay so all of these +progeny that I drew down here are + + align:start position:0% +progeny that I drew down here are + + + align:start position:0% +progeny that I drew down here are +recombinant because they don't resemble + + align:start position:0% +recombinant because they don't resemble + + + align:start position:0% +recombinant because they don't resemble +the parents right because there are + + align:start position:0% +the parents right because there are + + + align:start position:0% +the parents right because there are +three genes now there's many more ways + + align:start position:0% +three genes now there's many more ways + + + align:start position:0% +three genes now there's many more ways +to get recombinant progeny as opposed to + + align:start position:0% +to get recombinant progeny as opposed to + + + align:start position:0% +to get recombinant progeny as opposed to +having just two genes right so you can + + align:start position:0% +having just two genes right so you can + + + align:start position:0% +having just two genes right so you can +have many different combinations of + + align:start position:0% +have many different combinations of + + + align:start position:0% +have many different combinations of +these different alleles and so now I'm + + align:start position:0% +these different alleles and so now I'm + + + align:start position:0% +these different alleles and so now I'm +gonna give you data from across with + + align:start position:0% +gonna give you data from across with + + + align:start position:0% +gonna give you data from across with +three such genes so you might get 580 + + align:start position:0% +three such genes so you might get 580 + + + align:start position:0% +three such genes so you might get 580 +individuals that look like this 592 like + + align:start position:0% +individuals that look like this 592 like + + + align:start position:0% +individuals that look like this 592 like +this 45 and 48 e 994 three and five okay + + align:start position:0% +this 45 and 48 e 994 three and five okay + + + align:start position:0% +this 45 and 48 e 994 three and five okay +so this is data that is I believe from + + align:start position:0% +so this is data that is I believe from + + + align:start position:0% +so this is data that is I believe from +fly genes + + align:start position:0% +fly genes + + + align:start position:0% +fly genes +I've just ignored the fly nomenclature + + align:start position:0% +I've just ignored the fly nomenclature + + + align:start position:0% +I've just ignored the fly nomenclature +because it's confusing and just like + + align:start position:0% +because it's confusing and just like + + + align:start position:0% +because it's confusing and just like +giving them lettered names okay but this + + align:start position:0% +giving them lettered names okay but this + + + align:start position:0% +giving them lettered names okay but this +reflects data from some cross somewhere + + align:start position:0% +reflects data from some cross somewhere + + + align:start position:0% +reflects data from some cross somewhere +okay so now we want to know let's go + + align:start position:0% +okay so now we want to know let's go + + + align:start position:0% +okay so now we want to know let's go +back to our map we want to make a map + + align:start position:0% +back to our map we want to make a map + + + align:start position:0% +back to our map we want to make a map +okay and so to make our map we're gonna + + align:start position:0% +okay and so to make our map we're gonna + + + align:start position:0% +okay and so to make our map we're gonna +want to consider all pairwise different + + align:start position:0% +want to consider all pairwise different + + + align:start position:0% +want to consider all pairwise different +distances between different genes okay + + align:start position:0% +distances between different genes okay + + + align:start position:0% +distances between different genes okay +so we'll start with the a and B gene + + align:start position:0% +so we'll start with the a and B gene + + + align:start position:0% +so we'll start with the a and B gene +right over here so let's consider the a + + align:start position:0% +right over here so let's consider the a + + + align:start position:0% +right over here so let's consider the a +B distance and remember to get a + + align:start position:0% +B distance and remember to get a + + + align:start position:0% +B distance and remember to get a +distance we're looking at the number of + + align:start position:0% +distance we're looking at the number of + + + align:start position:0% +distance we're looking at the number of +the frequency which there is + + align:start position:0% +the frequency which there is + + + align:start position:0% +the frequency which there is +recombination between these two genes + + align:start position:0% +recombination between these two genes + + + align:start position:0% +recombination between these two genes +okay so we now have to look through + + align:start position:0% +okay so we now have to look through + + + align:start position:0% +okay so we now have to look through +all of these recombinant class of + + align:start position:0% +all of these recombinant class of + + + align:start position:0% +all of these recombinant class of +progeny and figure out the ones that + + align:start position:0% +progeny and figure out the ones that + + + align:start position:0% +progeny and figure out the ones that +have had a recombination between a and B + + align:start position:0% +have had a recombination between a and B + + + align:start position:0% +have had a recombination between a and B +right so on the parent chromosome you + + align:start position:0% +right so on the parent chromosome you + + + align:start position:0% +right so on the parent chromosome you +see little lowercase a started out with + + align:start position:0% +see little lowercase a started out with + + + align:start position:0% +see little lowercase a started out with +capital B okay + + align:start position:0% +capital B okay + + + align:start position:0% +capital B okay +and vice versa okay so any case where we + + align:start position:0% +and vice versa okay so any case where we + + + align:start position:0% +and vice versa okay so any case where we +don't have lowercase a paired with + + align:start position:0% +don't have lowercase a paired with + + + align:start position:0% +don't have lowercase a paired with +capital B there's been some type of + + align:start position:0% +capital B there's been some type of + + + align:start position:0% +capital B there's been some type of +exchange okay so here lowercase a is + + align:start position:0% +exchange okay so here lowercase a is + + + align:start position:0% +exchange okay so here lowercase a is +with lowercase B so that's a recombinant + + align:start position:0% +with lowercase B so that's a recombinant + + + align:start position:0% +with lowercase B so that's a recombinant +here uppercase a is with uppercase B + + align:start position:0% +here uppercase a is with uppercase B + + + align:start position:0% +here uppercase a is with uppercase B +that's been that's a recombinant too so + + align:start position:0% +that's been that's a recombinant too so + + + align:start position:0% +that's been that's a recombinant too so +we have to add all these up so 45 plus + + align:start position:0% +we have to add all these up so 45 plus + + + align:start position:0% +we have to add all these up so 45 plus +40 how about here recombination here or + + align:start position:0% +40 how about here recombination here or + + + align:start position:0% +40 how about here recombination here or +no yes I'm hearing yes that's correct + + align:start position:0% +no yes I'm hearing yes that's correct + + + align:start position:0% +no yes I'm hearing yes that's correct +here recombination yes or no I'm Karmen + + align:start position:0% +here recombination yes or no I'm Karmen + + + align:start position:0% +here recombination yes or no I'm Karmen +shaking her head no she's exactly right + + align:start position:0% +shaking her head no she's exactly right + + + align:start position:0% +shaking her head no she's exactly right +so we just have to these are all the + + align:start position:0% +so we just have to these are all the + + + align:start position:0% +so we just have to these are all the +recombinants between a and B so it's 45 + + align:start position:0% +recombinants between a and B so it's 45 + + + align:start position:0% +recombinants between a and B so it's 45 +plus 40 plus 89 plus 94 which equals 268 + + align:start position:0% +plus 40 plus 89 plus 94 which equals 268 + + + align:start position:0% +plus 40 plus 89 plus 94 which equals 268 +over a total progeny of 14 huh + + align:start position:0% +over a total progeny of 14 huh + + + align:start position:0% +over a total progeny of 14 huh +48 and that gives you a map distance of + + align:start position:0% +48 and that gives you a map distance of + + + align:start position:0% +48 and that gives you a map distance of +18.5% because this method was developed + + align:start position:0% +18.5% because this method was developed + + + align:start position:0% +18.5% because this method was developed +in Morgan's lab this measurement is also + + align:start position:0% +in Morgan's lab this measurement is also + + + align:start position:0% +in Morgan's lab this measurement is also +known as a centimorgan it was named in + + align:start position:0% +known as a centimorgan it was named in + + + align:start position:0% +known as a centimorgan it was named in +honor of Morgan so that's what I refer + + align:start position:0% +honor of Morgan so that's what I refer + + + align:start position:0% +honor of Morgan so that's what I refer +to and I have lowercase T capital M + + align:start position:0% +to and I have lowercase T capital M + + + align:start position:0% +to and I have lowercase T capital M +that's a centimorgan so you can also use + + align:start position:0% +that's a centimorgan so you can also use + + + align:start position:0% +that's a centimorgan so you can also use +centimorgan here alright so that's a and + + align:start position:0% +centimorgan here alright so that's a and + + + align:start position:0% +centimorgan here alright so that's a and +B but now we have to consider other + + align:start position:0% +B but now we have to consider other + + + align:start position:0% +B but now we have to consider other +distances so how about the ad distance + + align:start position:0% +distances so how about the ad distance + + + align:start position:0% +distances so how about the ad distance +and again we have to go through and + + align:start position:0% +and again we have to go through and + + + align:start position:0% +and again we have to go through and +figure out where the alleles for a and D + + align:start position:0% +figure out where the alleles for a and D + + + align:start position:0% +figure out where the alleles for a and D +have been recombined okay so little a is + + align:start position:0% +have been recombined okay so little a is + + + align:start position:0% +have been recombined okay so little a is +with big with capital D and uppercase a + + align:start position:0% +with big with capital D and uppercase a + + + align:start position:0% +with big with capital D and uppercase a +is with lowercase D so we have to find + + align:start position:0% +is with lowercase D so we have to find + + + align:start position:0% +is with lowercase D so we have to find +all the cases where that's not the case + + align:start position:0% +all the cases where that's not the case + + + align:start position:0% +all the cases where that's not the case +here this is lowercase a with capital D + + align:start position:0% +here this is lowercase a with capital D + + + align:start position:0% +here this is lowercase a with capital D +and capital A with lowercase D + + align:start position:0% +and capital A with lowercase D + + + align:start position:0% +and capital A with lowercase D +this is parental from the respect of + + align:start position:0% +this is parental from the respect of + + + align:start position:0% +this is parental from the respect of +just the a and D genes but all the rest + + align:start position:0% +just the a and D genes but all the rest + + + align:start position:0% +just the a and D genes but all the rest +of these guys are recombinant okay so + + align:start position:0% +of these guys are recombinant okay so + + + align:start position:0% +of these guys are recombinant okay so +this is 89 plus ninety four plus three + + align:start position:0% +this is 89 plus ninety four plus three + + + align:start position:0% +this is 89 plus ninety four plus three +plus five which comes out to be one + + align:start position:0% +plus five which comes out to be one + + + align:start position:0% +plus five which comes out to be one +hundred ninety one over one thousand + + align:start position:0% +hundred ninety one over one thousand + + + align:start position:0% +hundred ninety one over one thousand +four hundred forty eight and this is + + align:start position:0% +four hundred forty eight and this is + + + align:start position:0% +four hundred forty eight and this is +thirteen point two centimorgans so + + align:start position:0% +thirteen point two centimorgans so + + + align:start position:0% +thirteen point two centimorgans so +that's the distance between a and D okay + + align:start position:0% + + + + align:start position:0% + +distance between a be distance between a + + align:start position:0% +distance between a be distance between a + + + align:start position:0% +distance between a be distance between a +D so the last combination then is just B + + align:start position:0% +D so the last combination then is just B + + + align:start position:0% +D so the last combination then is just B +and D so if we consider the B D distance + + align:start position:0% +and D so if we consider the B D distance + + + align:start position:0% +and D so if we consider the B D distance +again we have to look for all cases in + + align:start position:0% +again we have to look for all cases in + + + align:start position:0% +again we have to look for all cases in +which lowercase B and D become separated + + align:start position:0% +which lowercase B and D become separated + + + align:start position:0% +which lowercase B and D become separated +an uppercase B and D become separated + + align:start position:0% +an uppercase B and D become separated + + + align:start position:0% +an uppercase B and D become separated +here they're separated here they're + + align:start position:0% +here they're separated here they're + + + align:start position:0% +here they're separated here they're +separated wait no not here sorry here + + align:start position:0% +separated wait no not here sorry here + + + align:start position:0% +separated wait no not here sorry here +they're not separated here they are + + align:start position:0% +they're not separated here they are + + + align:start position:0% +they're not separated here they are +separated say everyone see how I'm doing + + align:start position:0% +separated say everyone see how I'm doing + + + align:start position:0% +separated say everyone see how I'm doing +this are there any questions about it + + align:start position:0% +this are there any questions about it + + + align:start position:0% +this are there any questions about it +you can just shout it out if you have a + + align:start position:0% +you can just shout it out if you have a + + + align:start position:0% +you can just shout it out if you have a +question so this distance is six point + + align:start position:0% +question so this distance is six point + + + align:start position:0% +question so this distance is six point +four centimorgans okay everyone see how + + align:start position:0% +four centimorgans okay everyone see how + + + align:start position:0% +four centimorgans okay everyone see how +I'm considering every pairwise + + align:start position:0% +I'm considering every pairwise + + + align:start position:0% +I'm considering every pairwise +combination of genes and then just + + align:start position:0% +combination of genes and then just + + + align:start position:0% +combination of genes and then just +ignoring the other one and looking for + + align:start position:0% +ignoring the other one and looking for + + + align:start position:0% +ignoring the other one and looking for +where there's been a recombination in + + align:start position:0% +where there's been a recombination in + + + align:start position:0% +where there's been a recombination in +the progeny okay so now that we have our + + align:start position:0% +the progeny okay so now that we have our + + + align:start position:0% +the progeny okay so now that we have our +distances we can we can make our map + + align:start position:0% +distances we can we can make our map + + + align:start position:0% +distances we can we can make our map +right so the two genes that are farthest + + align:start position:0% +right so the two genes that are farthest + + + align:start position:0% +right so the two genes that are farthest +apart are a and B okay so that's kind of + + align:start position:0% +apart are a and B okay so that's kind of + + + align:start position:0% +apart are a and B okay so that's kind of +like here Rivendell and lonely mountain + + align:start position:0% +like here Rivendell and lonely mountain + + + align:start position:0% +like here Rivendell and lonely mountain +okay those are the two genes that are at + + align:start position:0% +okay those are the two genes that are at + + + align:start position:0% +okay those are the two genes that are at +the extremities okay so I'll draw this + + align:start position:0% +the extremities okay so I'll draw this + + + align:start position:0% +the extremities okay so I'll draw this +out we'll put it doesn't matter which + + align:start position:0% +out we'll put it doesn't matter which + + + align:start position:0% +out we'll put it doesn't matter which +way you put it + + align:start position:0% +way you put it + + + align:start position:0% +way you put it +we're just mapping these genes relative + + align:start position:0% +we're just mapping these genes relative + + + align:start position:0% +we're just mapping these genes relative +to each other but B and a are the + + align:start position:0% +to each other but B and a are the + + + align:start position:0% +to each other but B and a are the +farthest apart from each other + + align:start position:0% +farthest apart from each other + + + align:start position:0% +farthest apart from each other +now if we consider the distance between + + align:start position:0% +now if we consider the distance between + + + align:start position:0% +now if we consider the distance between +B and D that's six point four centimeter + + align:start position:0% +B and D that's six point four centimeter + + + align:start position:0% +B and D that's six point four centimeter +Morgan's so it appears that D is closer + + align:start position:0% +Morgan's so it appears that D is closer + + + align:start position:0% +Morgan's so it appears that D is closer +to be than it is to a because it's + + align:start position:0% +to be than it is to a because it's + + + align:start position:0% +to be than it is to a because it's +thirteen centimorgans away from a okay + + align:start position:0% +thirteen centimorgans away from a okay + + + align:start position:0% +thirteen centimorgans away from a okay +so D is kind of like Bayern's house here + + align:start position:0% +so D is kind of like Bayern's house here + + + align:start position:0% +so D is kind of like Bayern's house here +it's closer to Rivendell than it is from + + align:start position:0% +it's closer to Rivendell than it is from + + + align:start position:0% +it's closer to Rivendell than it is from +Lonely Mountain so we'll put that in + + align:start position:0% +Lonely Mountain so we'll put that in + + + align:start position:0% +Lonely Mountain so we'll put that in +there + + align:start position:0% +there + + + align:start position:0% +there +this distance is six point four + + align:start position:0% +this distance is six point four + + + align:start position:0% +this distance is six point four +centimorgans and then the distance here + + align:start position:0% +centimorgans and then the distance here + + + align:start position:0% +centimorgans and then the distance here +is thirteen point two centimorgans okay + + align:start position:0% +is thirteen point two centimorgans okay + + + align:start position:0% +is thirteen point two centimorgans okay +as far as I know no one in the field of + + align:start position:0% +as far as I know no one in the field of + + + align:start position:0% +as far as I know no one in the field of +genetic mapping has been assaulted by + + align:start position:0% +genetic mapping has been assaulted by + + + align:start position:0% +genetic mapping has been assaulted by +large spiders but the field is still + + align:start position:0% +large spiders but the field is still + + + align:start position:0% +large spiders but the field is still +young so one thing that should be maybe + + align:start position:0% +young so one thing that should be maybe + + + align:start position:0% +young so one thing that should be maybe +bothering you right now is if you add up + + align:start position:0% +bothering you right now is if you add up + + + align:start position:0% +bothering you right now is if you add up +the distance between B and D and D and a + + align:start position:0% +the distance between B and D and D and a + + + align:start position:0% +the distance between B and D and D and a +you don't in fact get eighteen point + + align:start position:0% +you don't in fact get eighteen point + + + align:start position:0% +you don't in fact get eighteen point +four centimorgans instead you get + + align:start position:0% +four centimorgans instead you get + + + align:start position:0% +four centimorgans instead you get +nineteen point six centimorgans this is + + align:start position:0% +nineteen point six centimorgans this is + + + align:start position:0% +nineteen point six centimorgans this is +nineteen point six sentence okay so it + + align:start position:0% +nineteen point six sentence okay so it + + + align:start position:0% +nineteen point six sentence okay so it +seems like somehow we are under + + align:start position:0% +seems like somehow we are under + + + align:start position:0% +seems like somehow we are under +estimating this distance here okay so we + + align:start position:0% +estimating this distance here okay so we + + + align:start position:0% +estimating this distance here okay so we +seem to be under estimating this so why + + align:start position:0% +seem to be under estimating this so why + + + align:start position:0% +seem to be under estimating this so why +is it that we are under estimating this + + align:start position:0% +is it that we are under estimating this + + + align:start position:0% +is it that we are under estimating this +distance well for to consider that you + + align:start position:0% +distance well for to consider that you + + + align:start position:0% +distance well for to consider that you +have to sort of look at what how all of + + align:start position:0% +have to sort of look at what how all of + + + align:start position:0% +have to sort of look at what how all of +these classes were generated okay so now + + align:start position:0% +these classes were generated okay so now + + + align:start position:0% +these classes were generated okay so now +I'm going to go through each class and + + align:start position:0% +I'm going to go through each class and + + + align:start position:0% +I'm going to go through each class and +we'll look at how it was generated I'm + + align:start position:0% +we'll look at how it was generated I'm + + + align:start position:0% +we'll look at how it was generated I'm +also going to well just draw new + + align:start position:0% +also going to well just draw new + + + align:start position:0% +also going to well just draw new +chromosomes so we have to draw this + + align:start position:0% +chromosomes so we have to draw this + + + align:start position:0% +chromosomes so we have to draw this +order now we have BD a so the first + + align:start position:0% +order now we have BD a so the first + + + align:start position:0% +order now we have BD a so the first +chromosome is B D a that's right + + align:start position:0% +chromosome is B D a that's right + + + align:start position:0% +chromosome is B D a that's right +BD a the other chromosome is B D + + align:start position:0% +BD a the other chromosome is B D + + + align:start position:0% +BD a the other chromosome is B D +eh okay so now we look and see how this + + align:start position:0% +eh okay so now we look and see how this + + + align:start position:0% +eh okay so now we look and see how this +recombinant class was generated okay so + + align:start position:0% +recombinant class was generated okay so + + + align:start position:0% +recombinant class was generated okay so +this is lowercase a well start with B + + align:start position:0% +this is lowercase a well start with B + + + align:start position:0% +this is lowercase a well start with B +lowercase B lowercase a but capital D ok + + align:start position:0% +lowercase B lowercase a but capital D ok + + + align:start position:0% +lowercase B lowercase a but capital D ok +so it's capital D lowercase a so that + + align:start position:0% +so it's capital D lowercase a so that + + + align:start position:0% +so it's capital D lowercase a so that +recombinant results from this chromosome + + align:start position:0% +recombinant results from this chromosome + + + align:start position:0% +recombinant results from this chromosome +here where there's crossing over and + + align:start position:0% +here where there's crossing over and + + + align:start position:0% +here where there's crossing over and +little B gets hooked up to Big D in + + align:start position:0% +little B gets hooked up to Big D in + + + align:start position:0% +little B gets hooked up to Big D in +little a okay see how I did that and + + align:start position:0% +little a okay see how I did that and + + + align:start position:0% +little a okay see how I did that and +then if we consider this class this is + + align:start position:0% +then if we consider this class this is + + + align:start position:0% +then if we consider this class this is +uppercase B lowercase D capital A okay + + align:start position:0% +uppercase B lowercase D capital A okay + + + align:start position:0% +uppercase B lowercase D capital A okay +so these two classes of progeny result + + align:start position:0% +so these two classes of progeny result + + + align:start position:0% +so these two classes of progeny result +from a single crossover between B and D + + align:start position:0% +from a single crossover between B and D + + + align:start position:0% +from a single crossover between B and D +okay so this is a single crossover + + align:start position:0% +okay so this is a single crossover + + + align:start position:0% +okay so this is a single crossover +between B and D genes and now we can go + + align:start position:0% +between B and D genes and now we can go + + + align:start position:0% +between B and D genes and now we can go +through and look at how this is + + align:start position:0% +through and look at how this is + + + align:start position:0% +through and look at how this is +generated so to get all recessive + + align:start position:0% +generated so to get all recessive + + + align:start position:0% +generated so to get all recessive +alleles on the same chromosome there + + align:start position:0% +alleles on the same chromosome there + + + align:start position:0% +alleles on the same chromosome there +would be a cross over here and so this + + align:start position:0% +would be a cross over here and so this + + + align:start position:0% +would be a cross over here and so this +is a single crossover between DNA so a + + align:start position:0% +is a single crossover between DNA so a + + + align:start position:0% +is a single crossover between DNA so a +single crossover between DNA now this + + align:start position:0% +single crossover between DNA now this + + + align:start position:0% +single crossover between DNA now this +last these last couple classes of + + align:start position:0% +last these last couple classes of + + + align:start position:0% +last these last couple classes of +progeny are interesting and that they're + + align:start position:0% +progeny are interesting and that they're + + + align:start position:0% +progeny are interesting and that they're +the least frequent class and so when we + + align:start position:0% +the least frequent class and so when we + + + align:start position:0% +the least frequent class and so when we +consider how they're generated we'll + + align:start position:0% +consider how they're generated we'll + + + align:start position:0% +consider how they're generated we'll +start with uppercase B let's see if I + + align:start position:0% +start with uppercase B let's see if I + + + align:start position:0% +start with uppercase B let's see if I +can get rid of this so uppercase B + + align:start position:0% +can get rid of this so uppercase B + + + align:start position:0% +can get rid of this so uppercase B +lowercase D lowercase a okay and so what + + align:start position:0% +lowercase D lowercase a okay and so what + + + align:start position:0% +lowercase D lowercase a okay and so what +this last class is is actually a double + + align:start position:0% +this last class is is actually a double + + + align:start position:0% +this last class is is actually a double +crossover okay so this is a double + + align:start position:0% +crossover okay so this is a double + + + align:start position:0% +crossover okay so this is a double +crossover and it's least frequent + + align:start position:0% +crossover and it's least frequent + + + align:start position:0% +crossover and it's least frequent +because it's there's a lower probability + + align:start position:0% +because it's there's a lower probability + + + align:start position:0% +because it's there's a lower probability +of getting two crossovers in this region + + align:start position:0% +of getting two crossovers in this region + + + align:start position:0% +of getting two crossovers in this region +but now you see that even though it + + align:start position:0% +but now you see that even though it + + + align:start position:0% +but now you see that even though it +doesn't look like there was + + align:start position:0% +doesn't look like there was + + + align:start position:0% +doesn't look like there was +recombination between a and D + + align:start position:0% +recombination between a and D + + + align:start position:0% +recombination between a and D +in fact there was there were two + + align:start position:0% +in fact there was there were two + + + align:start position:0% +in fact there was there were two +crossovers and it just looks like there + + align:start position:0% +crossovers and it just looks like there + + + align:start position:0% +crossovers and it just looks like there +was no recombination if you didn't see + + align:start position:0% +was no recombination if you didn't see + + + align:start position:0% +was no recombination if you didn't see +the behavior of gene gene D ok so if we + + align:start position:0% +the behavior of gene gene D ok so if we + + + align:start position:0% +the behavior of gene gene D ok so if we +take into account that there are + + align:start position:0% +take into account that there are + + + align:start position:0% +take into account that there are +actually double crossovers between B and + + align:start position:0% +actually double crossovers between B and + + + align:start position:0% +actually double crossovers between B and +a then if we add that into our + + align:start position:0% +a then if we add that into our + + + align:start position:0% +a then if we add that into our +calculation here where you add in 3 plus + + align:start position:0% +calculation here where you add in 3 plus + + + align:start position:0% +calculation here where you add in 3 plus +5 x 2 because as a double cross oh these + + align:start position:0% +5 x 2 because as a double cross oh these + + + align:start position:0% +5 x 2 because as a double cross oh these +are both double crossover events then + + align:start position:0% +are both double crossover events then + + + align:start position:0% +are both double crossover events then +you get the 19.6 sentiments that you + + align:start position:0% +you get the 19.6 sentiments that you + + + align:start position:0% +you get the 19.6 sentiments that you +would expect by adding up the other + + align:start position:0% +would expect by adding up the other + + + align:start position:0% +would expect by adding up the other +recombinations okay how is that is that + + align:start position:0% +recombinations okay how is that is that + + + align:start position:0% +recombinations okay how is that is that +clear to everybody + + align:start position:0% +clear to everybody + + + align:start position:0% +clear to everybody +you're gonna have to make maps like this + + align:start position:0% +you're gonna have to make maps like this + + + align:start position:0% +you're gonna have to make maps like this +on the problem set and possibly the test + + align:start position:0% +on the problem set and possibly the test + + + align:start position:0% +on the problem set and possibly the test +so make sure you can given yeah or e + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +it's because when you have two genes + + align:start position:0% +it's because when you have two genes + + + align:start position:0% +it's because when you have two genes +that are very far apart you can have + + align:start position:0% +that are very far apart you can have + + + align:start position:0% +that are very far apart you can have +multiple crossovers and when you have + + align:start position:0% +multiple crossovers and when you have + + + align:start position:0% +multiple crossovers and when you have +sort of crossovers that are in pairs of + + align:start position:0% +sort of crossovers that are in pairs of + + + align:start position:0% +sort of crossovers that are in pairs of +two then you're not it's going to go + + align:start position:0% +two then you're not it's going to go + + + align:start position:0% +two then you're not it's going to go +from one sand back to the other and so + + align:start position:0% +from one sand back to the other and so + + + align:start position:0% +from one sand back to the other and so +you're not going to see recombination + + align:start position:0% +you're not going to see recombination + + + align:start position:0% +you're not going to see recombination +between the two alleles so it's it's an + + align:start position:0% +between the two alleles so it's it's an + + + align:start position:0% +between the two alleles so it's it's an +underestimate because if you have + + align:start position:0% +underestimate because if you have + + + align:start position:0% +underestimate because if you have +multiples of 2 in terms of crossovers + + align:start position:0% +multiples of 2 in terms of crossovers + + + align:start position:0% +multiples of 2 in terms of crossovers +you're gonna miss the recombination + + align:start position:0% +you're gonna miss the recombination + + + align:start position:0% +you're gonna miss the recombination +events do you see what I mean + + align:start position:0% + + + + align:start position:0% + +you understand that you can miss the + + align:start position:0% +you understand that you can miss the + + + align:start position:0% +you understand that you can miss the +double crossover events yeah right so + + align:start position:0% +double crossover events yeah right so + + + align:start position:0% +double crossover events yeah right so +then you're gonna underestimate the + + align:start position:0% +then you're gonna underestimate the + + + align:start position:0% +then you're gonna underestimate the +number of crossovers that actually + + align:start position:0% +number of crossovers that actually + + + align:start position:0% +number of crossovers that actually +happened in that genetic region mm-hmm + + align:start position:0% +happened in that genetic region mm-hmm + + + align:start position:0% +happened in that genetic region mm-hmm +all right now I want to end with an + + align:start position:0% +all right now I want to end with an + + + align:start position:0% +all right now I want to end with an +experiment that again makes the point + + align:start position:0% +experiment that again makes the point + + + align:start position:0% +experiment that again makes the point +that that genes are these entities that + + align:start position:0% +that that genes are these entities that + + + align:start position:0% +that that genes are these entities that +are on chromosomes and so just like you + + align:start position:0% +are on chromosomes and so just like you + + + align:start position:0% +are on chromosomes and so just like you +can have linkage between two genes on + + align:start position:0% +can have linkage between two genes on + + + align:start position:0% +can have linkage between two genes on +the same chromosome you can also have + + align:start position:0% +the same chromosome you can also have + + + align:start position:0% +the same chromosome you can also have +linkage between genes and physical + + align:start position:0% +linkage between genes and physical + + + align:start position:0% +linkage between genes and physical +structures on chromosomes like the + + align:start position:0% +structures on chromosomes like the + + + align:start position:0% +structures on chromosomes like the +centromere okay so you could have genes + + align:start position:0% +centromere okay so you could have genes + + + align:start position:0% +centromere okay so you could have genes +like a and B here that are present on + + align:start position:0% +like a and B here that are present on + + + align:start position:0% +like a and B here that are present on +the chromosomes and present very near + + align:start position:0% +the chromosomes and present very near + + + align:start position:0% +the chromosomes and present very near +the centromere of those chromosomes okay + + align:start position:0% +the centromere of those chromosomes okay + + + align:start position:0% +the centromere of those chromosomes okay +so they could be right on top of the + + align:start position:0% +so they could be right on top of the + + + align:start position:0% +so they could be right on top of the +centromere okay and to show you how this + + align:start position:0% +centromere okay and to show you how this + + + align:start position:0% +centromere okay and to show you how this +manifests itself I have to tell you + + align:start position:0% +manifests itself I have to tell you + + + align:start position:0% +manifests itself I have to tell you +about another organism which is a + + align:start position:0% +about another organism which is a + + + align:start position:0% +about another organism which is a +unicellular organism called yeast and + + align:start position:0% +unicellular organism called yeast and + + + align:start position:0% +unicellular organism called yeast and +yeast is special in that it can exist in + + align:start position:0% +yeast is special in that it can exist in + + + align:start position:0% +yeast is special in that it can exist in +both a haploid and a diploid form so it + + align:start position:0% +both a haploid and a diploid form so it + + + align:start position:0% +both a haploid and a diploid form so it +has a life cycle that involves this + + align:start position:0% +has a life cycle that involves this + + + align:start position:0% +has a life cycle that involves this +going both as a haploid and as a diploid + + align:start position:0% +going both as a haploid and as a diploid + + + align:start position:0% +going both as a haploid and as a diploid +and so you can take yeast and we'll take + + align:start position:0% +and so you can take yeast and we'll take + + + align:start position:0% +and so you can take yeast and we'll take +two haploid yeast cells and much like + + align:start position:0% +two haploid yeast cells and much like + + + align:start position:0% +two haploid yeast cells and much like +gametes these confuse to form a zygote + + align:start position:0% +gametes these confuse to form a zygote + + + align:start position:0% +gametes these confuse to form a zygote +so in this case I'm taking again we'll + + align:start position:0% +so in this case I'm taking again we'll + + + align:start position:0% +so in this case I'm taking again we'll +consider two generic genes a and B and + + align:start position:0% +consider two generic genes a and B and + + + align:start position:0% +consider two generic genes a and B and +we'll make a diploid D cell that is + + align:start position:0% +we'll make a diploid D cell that is + + + align:start position:0% +we'll make a diploid D cell that is +heterozygous or hybrid for a and B and + + align:start position:0% +heterozygous or hybrid for a and B and + + + align:start position:0% +heterozygous or hybrid for a and B and +what's great and special about yeast and + + align:start position:0% +what's great and special about yeast and + + + align:start position:0% +what's great and special about yeast and +why I'm telling you about this is + + align:start position:0% +why I'm telling you about this is + + + align:start position:0% +why I'm telling you about this is +because as opposed to flies and us and + + align:start position:0% +because as opposed to flies and us and + + + align:start position:0% +because as opposed to flies and us and +other organisms the product of a single + + align:start position:0% +other organisms the product of a single + + + align:start position:0% +other organisms the product of a single +meiosis is packaged in like this single + + align:start position:0% +meiosis is packaged in like this single + + + align:start position:0% + +package if you will so the yeast can + + align:start position:0% +package if you will so the yeast can + + + align:start position:0% +package if you will so the yeast can +undergo meiosis and the product of a + + align:start position:0% +undergo meiosis and the product of a + + + align:start position:0% +undergo meiosis and the product of a +single meiosis is present in this case + + align:start position:0% +single meiosis is present in this case + + + align:start position:0% +single meiosis is present in this case +where each of these would represent a + + align:start position:0% +where each of these would represent a + + + align:start position:0% +where each of these would represent a +haploid cell that then can divide and + + align:start position:0% +haploid cell that then can divide and + + + align:start position:0% +haploid cell that then can divide and +make many cells but this is the product + + align:start position:0% +make many cells but this is the product + + + align:start position:0% +make many cells but this is the product +of a single meiosis in a package okay so + + align:start position:0% +of a single meiosis in a package okay so + + + align:start position:0% +of a single meiosis in a package okay so +you can actually see the direct like + + align:start position:0% +you can actually see the direct like + + + align:start position:0% +you can actually see the direct like +result of a mitotic division a single + + align:start position:0% +result of a mitotic division a single + + + align:start position:0% +result of a mitotic division a single +mitotic division so this is the product + + align:start position:0% +mitotic division so this is the product + + + align:start position:0% +mitotic division so this is the product +of single mitotic division okay and that + + align:start position:0% +of single mitotic division okay and that + + + align:start position:0% +of single mitotic division okay and that +specialty is when when we make gametes + + align:start position:0% +specialty is when when we make gametes + + + align:start position:0% +specialty is when when we make gametes +right we have individual cells all the + + align:start position:0% +right we have individual cells all the + + + align:start position:0% +right we have individual cells all the +products of meiosis are split up and + + align:start position:0% +products of meiosis are split up and + + + align:start position:0% +products of meiosis are split up and +then just one randomly finds an egg and + + align:start position:0% +then just one randomly finds an egg and + + + align:start position:0% +then just one randomly finds an egg and +fertilize it so you don't know which of + + align:start position:0% +fertilize it so you don't know which of + + + align:start position:0% +fertilize it so you don't know which of +the gametes are from the product of a + + align:start position:0% +the gametes are from the product of a + + + align:start position:0% +the gametes are from the product of a +single meiosis okay and so being able to + + align:start position:0% +single meiosis okay and so being able to + + + align:start position:0% +single meiosis okay and so being able to +see the product of a single meiosis + + align:start position:0% +see the product of a single meiosis + + + align:start position:0% +see the product of a single meiosis +allows us to see things like genes being + + align:start position:0% +allows us to see things like genes being + + + align:start position:0% +allows us to see things like genes being +linked to physical structures on the + + align:start position:0% +linked to physical structures on the + + + align:start position:0% +linked to physical structures on the +chromosome like the centromere okay so + + align:start position:0% +chromosome like the centromere okay so + + + align:start position:0% +chromosome like the centromere okay so +if we consider this case these two genes + + align:start position:0% +if we consider this case these two genes + + + align:start position:0% +if we consider this case these two genes +are both linked to the centromere and + + align:start position:0% +are both linked to the centromere and + + + align:start position:0% +are both linked to the centromere and +during metaphase of meiosis one they + + align:start position:0% +during metaphase of meiosis one they + + + align:start position:0% +during metaphase of meiosis one they +could align like this in which case you + + align:start position:0% +could align like this in which case you + + + align:start position:0% +could align like this in which case you +would get spores that are parental + + align:start position:0% +would get spores that are parental + + + align:start position:0% +would get spores that are parental +parental for both dominant alleles or + + align:start position:0% +parental for both dominant alleles or + + + align:start position:0% +parental for both dominant alleles or +parental for both recessive alleles okay + + align:start position:0% +parental for both recessive alleles okay + + + align:start position:0% +parental for both recessive alleles okay +so each of these cells is known as a + + align:start position:0% +so each of these cells is known as a + + + align:start position:0% +so each of these cells is known as a +spore so I'll label spore numbers here + + align:start position:0% +spore so I'll label spore numbers here + + + align:start position:0% +spore so I'll label spore numbers here +so this is spore number and in this case + + align:start position:0% +so this is spore number and in this case + + + align:start position:0% +so this is spore number and in this case +you get 1 2 spores that are dominant for + + align:start position:0% +you get 1 2 spores that are dominant for + + + align:start position:0% +you get 1 2 spores that are dominant for +both alleles and 2 spores that are + + align:start position:0% +both alleles and 2 spores that are + + + align:start position:0% +both alleles and 2 spores that are +recessive for both alleles and this is + + align:start position:0% +recessive for both alleles and this is + + + align:start position:0% +recessive for both alleles and this is +known because there are two types is + + align:start position:0% +known because there are two types is + + + align:start position:0% +known because there are two types is +known as a die type and this is a + + align:start position:0% +known as a die type and this is a + + + align:start position:0% +known as a die type and this is a +parental die type because you have two + + align:start position:0% +parental die type because you have two + + + align:start position:0% +parental die type because you have two +types of spores and they are both + + align:start position:0% +types of spores and they are both + + + align:start position:0% +types of spores and they are both +parental + + align:start position:0% + + + + align:start position:0% + +okay an alternative scenario is that + + align:start position:0% +okay an alternative scenario is that + + + align:start position:0% +okay an alternative scenario is that +these chromosomes would align + + align:start position:0% +these chromosomes would align + + + align:start position:0% +these chromosomes would align +differently right so you get parental + + align:start position:0% +differently right so you get parental + + + align:start position:0% +differently right so you get parental +spore is there however and alternatively + + align:start position:0% +spore is there however and alternatively + + + align:start position:0% +spore is there however and alternatively +you could have this configuration where + + align:start position:0% +you could have this configuration where + + + align:start position:0% +you could have this configuration where +this is now flipped and during meiosis + + align:start position:0% +this is now flipped and during meiosis + + + align:start position:0% +this is now flipped and during meiosis +one here these chromosomes move together + + align:start position:0% +one here these chromosomes move together + + + align:start position:0% +one here these chromosomes move together +and they again produce two types of + + align:start position:0% +and they again produce two types of + + + align:start position:0% +and they again produce two types of +spores so it's a die type but in this + + align:start position:0% +spores so it's a die type but in this + + + align:start position:0% +spores so it's a die type but in this +case all the spores are non-parental + + align:start position:0% +case all the spores are non-parental + + + align:start position:0% +case all the spores are non-parental +okay so another scenario is you get this + + align:start position:0% + + + + align:start position:0% + +and because there are two types and + + align:start position:0% +and because there are two types and + + + align:start position:0% +and because there are two types and +they're non parental this is known as + + align:start position:0% +they're non parental this is known as + + + align:start position:0% +they're non parental this is known as +non parental die type okay so that's a + + align:start position:0% +non parental die type okay so that's a + + + align:start position:0% +non parental die type okay so that's a +non parental die type okay + + align:start position:0% +non parental die type okay + + + align:start position:0% +non parental die type okay +and if if these genes are linked to the + + align:start position:0% +and if if these genes are linked to the + + + align:start position:0% +and if if these genes are linked to the +centromere completely then you can only + + align:start position:0% +centromere completely then you can only + + + align:start position:0% +centromere completely then you can only +get these two classes of packages okay + + align:start position:0% +get these two classes of packages okay + + + align:start position:0% +get these two classes of packages okay +so these genes are unlinked so the two + + align:start position:0% +so these genes are unlinked so the two + + + align:start position:0% +so these genes are unlinked so the two +genes are unlinked but both linked to + + align:start position:0% +genes are unlinked but both linked to + + + align:start position:0% +genes are unlinked but both linked to +the centromere then you get parental die + + align:start position:0% +the centromere then you get parental die + + + align:start position:0% +the centromere then you get parental die +type 50% parental die type 50% non + + align:start position:0% +type 50% parental die type 50% non + + + align:start position:0% +type 50% parental die type 50% non +parental died type so I'm abbreviating + + align:start position:0% +parental died type so I'm abbreviating + + + align:start position:0% +parental died type so I'm abbreviating +parental die Tate parental die type PD + + align:start position:0% +parental die Tate parental die type PD + + + align:start position:0% +parental die Tate parental die type PD +and non parental die type NPD okay so + + align:start position:0% +and non parental die type NPD okay so + + + align:start position:0% +and non parental die type NPD okay so +what has to happen to get another type + + align:start position:0% +what has to happen to get another type + + + align:start position:0% +what has to happen to get another type +of spore and another type of spore would + + align:start position:0% +of spore and another type of spore would + + + align:start position:0% +of spore and another type of spore would +be you could have spores that are all + + align:start position:0% +be you could have spores that are all + + + align:start position:0% +be you could have spores that are all +different genotypes from each other and + + align:start position:0% +different genotypes from each other and + + + align:start position:0% +different genotypes from each other and +that you have a cap dominant a be + + align:start position:0% +that you have a cap dominant a be + + + align:start position:0% +that you have a cap dominant a be +dominant a recessive be recessive a + + align:start position:0% +dominant a recessive be recessive a + + + align:start position:0% +dominant a recessive be recessive a +dominant B and lowercase am + + align:start position:0% +dominant B and lowercase am + + + align:start position:0% +dominant B and lowercase am +okay and this is known as tetra type + + align:start position:0% +okay and this is known as tetra type + + + align:start position:0% +okay and this is known as tetra type +because there are four types so how do + + align:start position:0% +because there are four types so how do + + + align:start position:0% +because there are four types so how do +you get this tetra type anyone have an + + align:start position:0% +you get this tetra type anyone have an + + + align:start position:0% +you get this tetra type anyone have an +idea yeah Jeremy + + align:start position:0% + + + + align:start position:0% + +where would the crossing-over happen + + align:start position:0% + + + + align:start position:0% + +but between between Deal Leal and what + + align:start position:0% +but between between Deal Leal and what + + + align:start position:0% +but between between Deal Leal and what +the crossing over would occur between + + align:start position:0% +the crossing over would occur between + + + align:start position:0% +the crossing over would occur between +the the gene and the centromere exactly + + align:start position:0% +the the gene and the centromere exactly + + + align:start position:0% +the the gene and the centromere exactly +Jeremy is exactly right so Jeremy said + + align:start position:0% +Jeremy is exactly right so Jeremy said + + + align:start position:0% +Jeremy is exactly right so Jeremy said +that in order to get a tetra type you + + align:start position:0% +that in order to get a tetra type you + + + align:start position:0% +that in order to get a tetra type you +have to have a recombination event but + + align:start position:0% +have to have a recombination event but + + + align:start position:0% +have to have a recombination event but +this time not between two genes but + + align:start position:0% +this time not between two genes but + + + align:start position:0% +this time not between two genes but +between a gene and the centromere so + + align:start position:0% +between a gene and the centromere so + + + align:start position:0% +between a gene and the centromere so +they have to at least one of the genes + + align:start position:0% +they have to at least one of the genes + + + align:start position:0% +they have to at least one of the genes +has to be unlinked to the centromere + + align:start position:0% +has to be unlinked to the centromere + + + align:start position:0% +has to be unlinked to the centromere +okay and in that case now you get you + + align:start position:0% +okay and in that case now you get you + + + align:start position:0% +okay and in that case now you get you +get a mitotic event that gives gives + + align:start position:0% +get a mitotic event that gives gives + + + align:start position:0% +get a mitotic event that gives gives +rise to four spores and there are four + + align:start position:0% +rise to four spores and there are four + + + align:start position:0% +rise to four spores and there are four +different ways to get this so if you + + align:start position:0% +different ways to get this so if you + + + align:start position:0% +different ways to get this so if you +have two genes unlinked and at least one + + align:start position:0% +have two genes unlinked and at least one + + + align:start position:0% +have two genes unlinked and at least one +is unlinked to the centromere then you + + align:start position:0% +is unlinked to the centromere then you + + + align:start position:0% +is unlinked to the centromere then you +get a pattern where you have a 1 to 1 to + + align:start position:0% +get a pattern where you have a 1 to 1 to + + + align:start position:0% +get a pattern where you have a 1 to 1 to +4 ratio between all these different + + align:start position:0% +4 ratio between all these different + + + align:start position:0% +4 ratio between all these different +events so you have a 1 to 1 to 4 ratio + + align:start position:0% +events so you have a 1 to 1 to 4 ratio + + + align:start position:0% +events so you have a 1 to 1 to 4 ratio +between parental die type non parental + + align:start position:0% +between parental die type non parental + + + align:start position:0% +between parental die type non parental +die type and tetra type okay and we can + + align:start position:0% +die type and tetra type okay and we can + + + align:start position:0% +die type and tetra type okay and we can +see this in yeast if you have two genes + + align:start position:0% +see this in yeast if you have two genes + + + align:start position:0% +see this in yeast if you have two genes +that are linked to the centromere you + + align:start position:0% +that are linked to the centromere you + + + align:start position:0% +that are linked to the centromere you +only get parental die types and non + + align:start position:0% +only get parental die types and non + + + align:start position:0% +only get parental die types and non +parental die types where virtually + + align:start position:0% +parental die types where virtually + + + align:start position:0% +parental die types where virtually +everything else gives rise to tetra + + align:start position:0% +everything else gives rise to tetra + + + align:start position:0% +everything else gives rise to tetra +types except if they're linked what + + align:start position:0% +types except if they're linked what + + + align:start position:0% +types except if they're linked what +happens if the two genes are linked to + + align:start position:0% +happens if the two genes are linked to + + + align:start position:0% +happens if the two genes are linked to +each other + + align:start position:0% +each other + + + align:start position:0% +each other +irregardless of the centromere if you + + align:start position:0% +irregardless of the centromere if you + + + align:start position:0% +irregardless of the centromere if you +have two genes that are linked what's + + align:start position:0% +have two genes that are linked what's + + + align:start position:0% +have two genes that are linked what's +gonna be what are your progeny you gonna + + align:start position:0% +gonna be what are your progeny you gonna + + + align:start position:0% +gonna be what are your progeny you gonna +look like + + align:start position:0% + + + + align:start position:0% + +you're only gonna get the parentals or + + align:start position:0% +you're only gonna get the parentals or + + + align:start position:0% +you're only gonna get the parentals or +you're gonna get a lot of parentals + + align:start position:0% +you're gonna get a lot of parentals + + + align:start position:0% +you're gonna get a lot of parentals +Xavier is exactly right + + align:start position:0% +Xavier is exactly right + + + align:start position:0% +Xavier is exactly right +right if the two genes are linked the + + align:start position:0% +right if the two genes are linked the + + + align:start position:0% +right if the two genes are linked the +parental die tapes are going to be much + + align:start position:0% +parental die tapes are going to be much + + + align:start position:0% +parental die tapes are going to be much +greater than any of the other classes + + align:start position:0% + + + + align:start position:0% + +okay now this might seem ISO Tarek but I + + align:start position:0% +okay now this might seem ISO Tarek but I + + + align:start position:0% +okay now this might seem ISO Tarek but I +like the idea that you can have linkage + + align:start position:0% +like the idea that you can have linkage + + + align:start position:0% +like the idea that you can have linkage +between a gene and something that's like + + align:start position:0% +between a gene and something that's like + + + align:start position:0% +between a gene and something that's like +just the place on the chromosome that's + + align:start position:0% +just the place on the chromosome that's + + + align:start position:0% +just the place on the chromosome that's +getting physically pulled it all makes + + align:start position:0% +getting physically pulled it all makes + + + align:start position:0% +getting physically pulled it all makes +it much more physical which I I think is + + align:start position:0% +it much more physical which I I think is + + + align:start position:0% +it much more physical which I I think is +nice to think about all right we're + + align:start position:0% +nice to think about all right we're + + + align:start position:0% +nice to think about all right we're +almost done I just have yes Natalie + + align:start position:0% + + + + align:start position:0% + +yes so PD is parental die type so this + + align:start position:0% +yes so PD is parental die type so this + + + align:start position:0% +yes so PD is parental die type so this +is the parental die type it's a class of + + align:start position:0% +is the parental die type it's a class of + + + align:start position:0% +is the parental die type it's a class of +product here where you get four spores + + align:start position:0% +product here where you get four spores + + + align:start position:0% +product here where you get four spores +that are each of these genotypes okay so + + align:start position:0% +that are each of these genotypes okay so + + + align:start position:0% +that are each of these genotypes okay so +each of these one two three and four + + align:start position:0% +each of these one two three and four + + + align:start position:0% +each of these one two three and four +would represent one of these cells from + + align:start position:0% +would represent one of these cells from + + + align:start position:0% +would represent one of these cells from +a single mitotic event does that make + + align:start position:0% +a single mitotic event does that make + + + align:start position:0% +a single mitotic event does that make +sense Natalie okay does it does everyone + + align:start position:0% +sense Natalie okay does it does everyone + + + align:start position:0% +sense Natalie okay does it does everyone +see what I did there okay so these 1 2 & + + align:start position:0% +see what I did there okay so these 1 2 & + + + align:start position:0% +see what I did there okay so these 1 2 & +3 are the spores of the mud the mitotic + + align:start position:0% +3 are the spores of the mud the mitotic + + + align:start position:0% +3 are the spores of the mud the mitotic +event right here + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/k7CqAVzhkoo.txt b/k7CqAVzhkoo.txt new file mode 100644 index 0000000000000000000000000000000000000000..41c685b39de93db765caf34b307d5080fb53fa06 --- /dev/null +++ b/k7CqAVzhkoo.txt @@ -0,0 +1,99 @@ +align:start position:0% + +in our tutorials published on mit's open + + align:start position:0% +in our tutorials published on mit's open + + + align:start position:0% +in our tutorials published on mit's open +course whereare we're going to take a + + align:start position:0% +course whereare we're going to take a + + + align:start position:0% +course whereare we're going to take a +look at how you can use a flatbed + + align:start position:0% +look at how you can use a flatbed + + + align:start position:0% +look at how you can use a flatbed +scanner to create images of + + align:start position:0% +scanner to create images of + + + align:start position:0% +scanner to create images of +three-dimensional objects like + + align:start position:0% +three-dimensional objects like + + + align:start position:0% +three-dimensional objects like +microfluidic devices Petri dishes and + + align:start position:0% +microfluidic devices Petri dishes and + + + align:start position:0% +microfluidic devices Petri dishes and +other sorts of material you're creating + + align:start position:0% +other sorts of material you're creating + + + align:start position:0% +other sorts of material you're creating +or working with in your lab we want to + + align:start position:0% +or working with in your lab we want to + + + align:start position:0% +or working with in your lab we want to +encourage you to capture your material + + align:start position:0% +encourage you to capture your material + + + align:start position:0% +encourage you to capture your material +in a number of ways and probably + + align:start position:0% +in a number of ways and probably + + + align:start position:0% +in a number of ways and probably +probably most important to learn to see + + align:start position:0% +probably most important to learn to see + + + align:start position:0% +probably most important to learn to see +in the process you'll see lots more when + + align:start position:0% +in the process you'll see lots more when + + + align:start position:0% +in the process you'll see lots more when +you go to the site and that's a promise \ No newline at end of file diff --git a/lsf0_6DAFOM.txt b/lsf0_6DAFOM.txt new file mode 100644 index 0000000000000000000000000000000000000000..7379818c3f9523fb55149d8168b08f72320d7ac4 --- /dev/null +++ b/lsf0_6DAFOM.txt @@ -0,0 +1,6515 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license + + align:start position:0% +a Creative Commons license + + + align:start position:0% +a Creative Commons license +your support will help MIT + + align:start position:0% +your support will help MIT + + + align:start position:0% +your support will help MIT +OpenCourseWare continue to offer high + + align:start position:0% +OpenCourseWare continue to offer high + + + align:start position:0% +OpenCourseWare continue to offer high +quality educational resources for free + + align:start position:0% +quality educational resources for free + + + align:start position:0% +quality educational resources for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu + + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu +where we are in science I'm speaking as + + align:start position:0% +where we are in science I'm speaking as + + + align:start position:0% +where we are in science I'm speaking as +a professional scientist and the wall + + align:start position:0% +a professional scientist and the wall + + + align:start position:0% +a professional scientist and the wall +that we're hitting in communicating our + + align:start position:0% +that we're hitting in communicating our + + + align:start position:0% +that we're hitting in communicating our +science and having things translate out + + align:start position:0% +science and having things translate out + + + align:start position:0% +science and having things translate out +of there I'm aware of a paper that has + + align:start position:0% +of there I'm aware of a paper that has + + + align:start position:0% +of there I'm aware of a paper that has +just published a few weeks ago that on + + align:start position:0% +just published a few weeks ago that on + + + align:start position:0% +just published a few weeks ago that on +the importance of storytelling in + + align:start position:0% +the importance of storytelling in + + + align:start position:0% +the importance of storytelling in +science and that they found that + + align:start position:0% +science and that they found that + + + align:start position:0% +science and that they found that +published journal articles that had more + + align:start position:0% +published journal articles that had more + + + align:start position:0% +published journal articles that had more +of a narrative structure are getting + + align:start position:0% +of a narrative structure are getting + + + align:start position:0% +of a narrative structure are getting +cited more because people want to hear + + align:start position:0% +cited more because people want to hear + + + align:start position:0% +cited more because people want to hear +stories the dry scientific just the + + align:start position:0% +stories the dry scientific just the + + + align:start position:0% +stories the dry scientific just the +facts aren't working in one of your + + align:start position:0% +facts aren't working in one of your + + + align:start position:0% +facts aren't working in one of your +storage so I want to share my story with + + align:start position:0% +storage so I want to share my story with + + + align:start position:0% +storage so I want to share my story with +you about how I got involved in this + + align:start position:0% +you about how I got involved in this + + + align:start position:0% +you about how I got involved in this +ghastly stuff and then I'll handle the + + align:start position:0% +ghastly stuff and then I'll handle the + + + align:start position:0% +ghastly stuff and then I'll handle the +tom to Audrey and she'll take it from + + align:start position:0% +tom to Audrey and she'll take it from + + + align:start position:0% +tom to Audrey and she'll take it from +there but I started into this thing + + align:start position:0% +there but I started into this thing + + + align:start position:0% +there but I started into this thing +about the methane gas leaks as a citizen + + align:start position:0% +about the methane gas leaks as a citizen + + + align:start position:0% +about the methane gas leaks as a citizen +this started in 2010 November 2010 for + + align:start position:0% +this started in 2010 November 2010 for + + + align:start position:0% +this started in 2010 November 2010 for +me walking two blocks away from our home + + align:start position:0% +me walking two blocks away from our home + + + align:start position:0% +me walking two blocks away from our home +in Newton in the Auburndale village of + + align:start position:0% +in Newton in the Auburndale village of + + + align:start position:0% +in Newton in the Auburndale village of +Newton with my 10 year old son was seven + + align:start position:0% +Newton with my 10 year old son was seven + + + align:start position:0% +Newton with my 10 year old son was seven +or eight years old at that time Julian + + align:start position:0% +or eight years old at that time Julian + + + align:start position:0% +or eight years old at that time Julian +and two blocks away from our home we + + align:start position:0% +and two blocks away from our home we + + + align:start position:0% +and two blocks away from our home we +came upon a gas leak and someone who was + + align:start position:0% +came upon a gas leak and someone who was + + + align:start position:0% +came upon a gas leak and someone who was +working upon gas leaks Bob aptly gas + + align:start position:0% +working upon gas leaks Bob aptly gas + + + align:start position:0% +working upon gas leaks Bob aptly gas +safety USA + + align:start position:0% +safety USA + + + align:start position:0% +safety USA +he's a 30-year professional non + + align:start position:0% +he's a 30-year professional non + + + align:start position:0% +he's a 30-year professional non +scientist but that curiosity of what are + + align:start position:0% +scientist but that curiosity of what are + + + align:start position:0% +scientist but that curiosity of what are +you doing there he look like + + align:start position:0% +you doing there he look like + + + align:start position:0% +you doing there he look like +ghostbusters you know with a metal + + align:start position:0% +ghostbusters you know with a metal + + + align:start position:0% +ghostbusters you know with a metal +detector but it was a gas meter and + + align:start position:0% +detector but it was a gas meter and + + + align:start position:0% +detector but it was a gas meter and +that's how we I got involved in + + align:start position:0% +that's how we I got involved in + + + align:start position:0% +that's how we I got involved in +understanding this problem with gas + + align:start position:0% +understanding this problem with gas + + + align:start position:0% +understanding this problem with gas +leaks so he was as a citizen and for me + + align:start position:0% +leaks so he was as a citizen and for me + + + align:start position:0% +leaks so he was as a citizen and for me +that has started a process by which I've + + align:start position:0% +that has started a process by which I've + + + align:start position:0% +that has started a process by which I've +grown + + align:start position:0% +grown + + + align:start position:0% +grown +as a scientist citizen and come into a + + align:start position:0% +as a scientist citizen and come into a + + + align:start position:0% +as a scientist citizen and come into a +community science framework working with + + align:start position:0% +community science framework working with + + + align:start position:0% +community science framework working with +Audrey and a whole group of other + + align:start position:0% +Audrey and a whole group of other + + + align:start position:0% +Audrey and a whole group of other +citizens in a community and we've + + align:start position:0% +citizens in a community and we've + + + align:start position:0% +citizens in a community and we've +defined I think a community that crosses + + align:start position:0% +defined I think a community that crosses + + + align:start position:0% +defined I think a community that crosses +all kinds of boundaries to address the + + align:start position:0% +all kinds of boundaries to address the + + + align:start position:0% +all kinds of boundaries to address the +problem of gasoline so from that first + + align:start position:0% +problem of gasoline so from that first + + + align:start position:0% +problem of gasoline so from that first +chance citizen you know kind of + + align:start position:0% +chance citizen you know kind of + + + align:start position:0% +chance citizen you know kind of +experience for me until 2013 this the + + align:start position:0% +experience for me until 2013 this the + + + align:start position:0% +experience for me until 2013 this the +science part of this developed that we + + align:start position:0% +science part of this developed that we + + + align:start position:0% +science part of this developed that we +mapped out over 3000 of these gas leaks + + align:start position:0% +mapped out over 3000 of these gas leaks + + + align:start position:0% +mapped out over 3000 of these gas leaks +in the city of Boston and then we + + align:start position:0% +in the city of Boston and then we + + + align:start position:0% +in the city of Boston and then we +followed it up with a study in which we + + align:start position:0% +followed it up with a study in which we + + + align:start position:0% +followed it up with a study in which we +estimated that the amount of gas being + + align:start position:0% +estimated that the amount of gas being + + + align:start position:0% +estimated that the amount of gas being +lost in eastern Massachusetts amounted + + align:start position:0% +lost in eastern Massachusetts amounted + + + align:start position:0% +lost in eastern Massachusetts amounted +to about 10% of the Commonwealth's + + align:start position:0% +to about 10% of the Commonwealth's + + + align:start position:0% +to about 10% of the Commonwealth's +greenhouse gas emissions inventory and + + align:start position:0% +greenhouse gas emissions inventory and + + + align:start position:0% +greenhouse gas emissions inventory and +so and then that propelled a coalition + + align:start position:0% +so and then that propelled a coalition + + + align:start position:0% +so and then that propelled a coalition +of a community to then say how do we + + align:start position:0% +of a community to then say how do we + + + align:start position:0% +of a community to then say how do we +move our political leaders to actually + + align:start position:0% +move our political leaders to actually + + + align:start position:0% +move our political leaders to actually +create policy to address this situation + + align:start position:0% +create policy to address this situation + + + align:start position:0% +create policy to address this situation +so it's been a really fulfilling thing + + align:start position:0% +so it's been a really fulfilling thing + + + align:start position:0% +so it's been a really fulfilling thing +for me and I'll just say that the + + align:start position:0% +for me and I'll just say that the + + + align:start position:0% +for me and I'll just say that the +science that we did actually and what we + + align:start position:0% +science that we did actually and what we + + + align:start position:0% +science that we did actually and what we +publish in the journals is not new but + + align:start position:0% +publish in the journals is not new but + + + align:start position:0% +publish in the journals is not new but +the problem had been known about for + + align:start position:0% +the problem had been known about for + + + align:start position:0% +the problem had been known about for +decades it's just that it was not known + + align:start position:0% +decades it's just that it was not known + + + align:start position:0% +decades it's just that it was not known +to the public so we found citizen after + + align:start position:0% +to the public so we found citizen after + + + align:start position:0% +to the public so we found citizen after +citizen in different neighborhoods of + + align:start position:0% +citizen in different neighborhoods of + + + align:start position:0% +citizen in different neighborhoods of +Boston that would say oh you know I know + + align:start position:0% +Boston that would say oh you know I know + + + align:start position:0% +Boston that would say oh you know I know +about a gas leak I smell it every time I + + align:start position:0% +about a gas leak I smell it every time I + + + align:start position:0% +about a gas leak I smell it every time I +go walking to the store and so what we + + align:start position:0% +go walking to the store and so what we + + + align:start position:0% +go walking to the store and so what we +realized is that there were hundreds of + + align:start position:0% +realized is that there were hundreds of + + + align:start position:0% +realized is that there were hundreds of +anecdotes that were completely in siloed + + align:start position:0% +anecdotes that were completely in siloed + + + align:start position:0% +anecdotes that were completely in siloed +from each other and once we put a map + + align:start position:0% +from each other and once we put a map + + + align:start position:0% +from each other and once we put a map +out there every the community everyone + + align:start position:0% +out there every the community everyone + + + align:start position:0% +out there every the community everyone +could see the whole thing collectively + + align:start position:0% +could see the whole thing collectively + + + align:start position:0% +could see the whole thing collectively +at the same time and that was the only + + align:start position:0% +at the same time and that was the only + + + align:start position:0% +at the same time and that was the only +thing we did we just made it visible and + + align:start position:0% +thing we did we just made it visible and + + + align:start position:0% +thing we did we just made it visible and +then Audrey took it to the next step in + + align:start position:0% +then Audrey took it to the next step in + + + align:start position:0% +then Audrey took it to the next step in +all cast of atonte + + align:start position:0% +all cast of atonte + + + align:start position:0% +all cast of atonte +okay so um thanks um so I'm just gonna + + align:start position:0% +okay so um thanks um so I'm just gonna + + + align:start position:0% +okay so um thanks um so I'm just gonna +talk for one second about what actually + + align:start position:0% +talk for one second about what actually + + + align:start position:0% +talk for one second about what actually +gas leaks are since + + align:start position:0% +gas leaks are since + + + align:start position:0% +gas leaks are since +net from pipes under the street right so + + align:start position:0% +net from pipes under the street right so + + + align:start position:0% +net from pipes under the street right so +a lot of our pipes on our street are + + align:start position:0% +a lot of our pipes on our street are + + + align:start position:0% +a lot of our pipes on our street are +really old here's a close-up detail of + + align:start position:0% +really old here's a close-up detail of + + + align:start position:0% +really old here's a close-up detail of +Back Bay a National Grid map very small + + align:start position:0% +Back Bay a National Grid map very small + + + align:start position:0% +Back Bay a National Grid map very small +detail of it and you can see the two of + + align:start position:0% +detail of it and you can see the two of + + + align:start position:0% +detail of it and you can see the two of +the pipes running down that the 1861 is + + align:start position:0% +the pipes running down that the 1861 is + + + align:start position:0% +the pipes running down that the 1861 is +a pipe from 1860 running down Beacon + + align:start position:0% +a pipe from 1860 running down Beacon + + + align:start position:0% +a pipe from 1860 running down Beacon +Street and two streets away running down + + align:start position:0% +Street and two streets away running down + + + align:start position:0% +Street and two streets away running down +comm F is one from 1882 and those pipes + + align:start position:0% +comm F is one from 1882 and those pipes + + + align:start position:0% +comm F is one from 1882 and those pipes +are still in use so we got some really + + align:start position:0% +are still in use so we got some really + + + align:start position:0% +are still in use so we got some really +old infrastructure around the problem + + align:start position:0% +old infrastructure around the problem + + + align:start position:0% +old infrastructure around the problem +with gas leaks is the potentially + + align:start position:0% +with gas leaks is the potentially + + + align:start position:0% +with gas leaks is the potentially +explosive this is a picture of Harlem + + align:start position:0% +explosive this is a picture of Harlem + + + align:start position:0% +explosive this is a picture of Harlem +the explosion in Harlem about two years + + align:start position:0% +the explosion in Harlem about two years + + + align:start position:0% +the explosion in Harlem about two years +ago I think 2014 and they as the gas + + align:start position:0% +ago I think 2014 and they as the gas + + + align:start position:0% +ago I think 2014 and they as the gas +percolates up through the soil it pushes + + align:start position:0% +percolates up through the soil it pushes + + + align:start position:0% +percolates up through the soil it pushes +oxygen out and trees actually need to + + align:start position:0% +oxygen out and trees actually need to + + + align:start position:0% +oxygen out and trees actually need to +breathe oxygen through their roots so + + align:start position:0% +breathe oxygen through their roots so + + + align:start position:0% +breathe oxygen through their roots so +they can die the and then it's as Nathan + + align:start position:0% +they can die the and then it's as Nathan + + + align:start position:0% +they can die the and then it's as Nathan +said a powerful greenhouse gas if you + + align:start position:0% +said a powerful greenhouse gas if you + + + align:start position:0% +said a powerful greenhouse gas if you +burn a natural gas it's turned into co2 + + align:start position:0% +burn a natural gas it's turned into co2 + + + align:start position:0% +burn a natural gas it's turned into co2 +if you don't burn it it stays at methane + + align:start position:0% +if you don't burn it it stays at methane + + + align:start position:0% +if you don't burn it it stays at methane +as methane methane on a 20-year time + + align:start position:0% +as methane methane on a 20-year time + + + align:start position:0% +as methane methane on a 20-year time +frame is a hundred times 86 times more + + align:start position:0% +frame is a hundred times 86 times more + + + align:start position:0% +frame is a hundred times 86 times more +damaging than co2 and finally we have to + + align:start position:0% +damaging than co2 and finally we have to + + + align:start position:0% +damaging than co2 and finally we have to +pay for it because the utilities can + + align:start position:0% +pay for it because the utilities can + + + align:start position:0% +pay for it because the utilities can +pass that cost on to us the ratepayers + + align:start position:0% +pass that cost on to us the ratepayers + + + align:start position:0% +pass that cost on to us the ratepayers +so it's sort of just insulting so when I + + align:start position:0% +so it's sort of just insulting so when I + + + align:start position:0% +so it's sort of just insulting so when I +read about Nathan's first I run an + + align:start position:0% +read about Nathan's first I run an + + + align:start position:0% +read about Nathan's first I run an +energy efficiency nonprofit and + + align:start position:0% +energy efficiency nonprofit and + + + align:start position:0% +energy efficiency nonprofit and +primarily we used to work in the + + align:start position:0% +primarily we used to work in the + + + align:start position:0% +primarily we used to work in the +buildings of nonprofits to help them + + align:start position:0% +buildings of nonprofits to help them + + + align:start position:0% +buildings of nonprofits to help them +lower their energy bills and energy + + align:start position:0% +lower their energy bills and energy + + + align:start position:0% +lower their energy bills and energy +emissions and so then well a lot with + + align:start position:0% +emissions and so then well a lot with + + + align:start position:0% +emissions and so then well a lot with +mass save which is the state's energy + + align:start position:0% +mass save which is the state's energy + + + align:start position:0% +mass save which is the state's energy +efficiency you know state funded program + + align:start position:0% +efficiency you know state funded program + + + align:start position:0% +efficiency you know state funded program +or and so I've read about Nathan's + + align:start position:0% +or and so I've read about Nathan's + + + align:start position:0% +or and so I've read about Nathan's +research when he surveyed all of Boston + + align:start position:0% +research when he surveyed all of Boston + + + align:start position:0% +research when he surveyed all of Boston +and found those over 3,300 gas leaks and + + align:start position:0% +and found those over 3,300 gas leaks and + + + align:start position:0% +and found those over 3,300 gas leaks and +there was one line in the article that + + align:start position:0% +there was one line in the article that + + + align:start position:0% +there was one line in the article that +said that the amount of gas lost in just + + align:start position:0% +said that the amount of gas lost in just + + + align:start position:0% +said that the amount of gas lost in just +Boston alone totally erased all of the + + align:start position:0% +Boston alone totally erased all of the + + + align:start position:0% +Boston alone totally erased all of the +state's energy efficiency programs and + + align:start position:0% +state's energy efficiency programs and + + + align:start position:0% +state's energy efficiency programs and +so I was that was it I was in so I + + align:start position:0% +so I was that was it I was in so I + + + align:start position:0% +so I was that was it I was in so I +called up Nathan and + + align:start position:0% +called up Nathan and + + + align:start position:0% +called up Nathan and +said how can I help and he was kind + + align:start position:0% +said how can I help and he was kind + + + align:start position:0% +said how can I help and he was kind +enough to loan us his extremely fancy + + align:start position:0% +enough to loan us his extremely fancy + + + align:start position:0% +enough to loan us his extremely fancy +cool equipment which is called a Picaro + + align:start position:0% +cool equipment which is called a Picaro + + + align:start position:0% +cool equipment which is called a Picaro +high precision natural gas analyzer and + + align:start position:0% +high precision natural gas analyzer and + + + align:start position:0% +high precision natural gas analyzer and +we drove it all over cambridge and + + align:start position:0% +we drove it all over cambridge and + + + align:start position:0% +we drove it all over cambridge and +somerville so the yellow lines are where + + align:start position:0% +somerville so the yellow lines are where + + + align:start position:0% +somerville so the yellow lines are where +we drove or not we Bob Ackley drove but + + align:start position:0% +we drove or not we Bob Ackley drove but + + + align:start position:0% +we drove or not we Bob Ackley drove but +and the spikes are where there's + + align:start position:0% +and the spikes are where there's + + + align:start position:0% +and the spikes are where there's +elevated levels of methane found and so + + align:start position:0% +elevated levels of methane found and so + + + align:start position:0% +elevated levels of methane found and so +and its are fascinating + + align:start position:0% +and its are fascinating + + + align:start position:0% +and its are fascinating +we found no correlation between income + + align:start position:0% +we found no correlation between income + + + align:start position:0% +we found no correlation between income +level of neighborhoods and because + + align:start position:0% +level of neighborhoods and because + + + align:start position:0% +level of neighborhoods and because +they're just there there you'll see them + + align:start position:0% +they're just there there you'll see them + + + align:start position:0% +they're just there there you'll see them +sort of somewhat clustered together + + align:start position:0% +sort of somewhat clustered together + + + align:start position:0% +sort of somewhat clustered together +because neighborhoods are built at the + + align:start position:0% +because neighborhoods are built at the + + + align:start position:0% +because neighborhoods are built at the +same time generally using you know same + + align:start position:0% +same time generally using you know same + + + align:start position:0% +same time generally using you know same +infrastructure same material here's what + + align:start position:0% +infrastructure same material here's what + + + align:start position:0% +infrastructure same material here's what +I call the the Alps of North Somerville + + align:start position:0% +I call the the Alps of North Somerville + + + align:start position:0% +I call the the Alps of North Somerville +and we will be going to will be doing a + + align:start position:0% +and we will be going to will be doing a + + + align:start position:0% +and we will be going to will be doing a +leak survey in the fantastic van with + + align:start position:0% +leak survey in the fantastic van with + + + align:start position:0% +leak survey in the fantastic van with +the Picaro so you can come along and see + + align:start position:0% +the Picaro so you can come along and see + + + align:start position:0% +the Picaro so you can come along and see +these on your own + + align:start position:0% +these on your own + + + align:start position:0% +these on your own +and do some surveying on your own then + + align:start position:0% +and do some surveying on your own then + + + align:start position:0% +and do some surveying on your own then +hmm and smelly yeah I mean we can also + + align:start position:0% +hmm and smelly yeah I mean we can also + + + align:start position:0% +hmm and smelly yeah I mean we can also +my overseas what's fascinating to me is + + align:start position:0% +my overseas what's fascinating to me is + + + align:start position:0% +my overseas what's fascinating to me is +like there was one near my house I + + align:start position:0% +like there was one near my house I + + + align:start position:0% +like there was one near my house I +would've was bike along with Charles and + + align:start position:0% +would've was bike along with Charles and + + + align:start position:0% +would've was bike along with Charles and +there was this one huge gas leak I would + + align:start position:0% +there was this one huge gas leak I would + + + align:start position:0% +there was this one huge gas leak I would +smell all the time and I would always + + align:start position:0% +smell all the time and I would always + + + align:start position:0% +smell all the time and I would always +think like can't be because I'm looking + + align:start position:0% +think like can't be because I'm looking + + + align:start position:0% +think like can't be because I'm looking +around and I'm seeing all the other + + align:start position:0% +around and I'm seeing all the other + + + align:start position:0% +around and I'm seeing all the other +people and they're just walking by so I + + align:start position:0% +people and they're just walking by so I + + + align:start position:0% +people and they're just walking by so I +always thought like I must just be + + align:start position:0% +always thought like I must just be + + + align:start position:0% +always thought like I must just be +making it up um but then I called it in + + align:start position:0% +making it up um but then I called it in + + + align:start position:0% +making it up um but then I called it in +and it was fixed and after that I never + + align:start position:0% +and it was fixed and after that I never + + + align:start position:0% +and it was fixed and after that I never +smelled it again and that was so like we + + align:start position:0% +smelled it again and that was so like we + + + align:start position:0% +smelled it again and that was so like we +just don't believe our noses um so after + + align:start position:0% +just don't believe our noses um so after + + + align:start position:0% +just don't believe our noses um so after +I we did the Cambridge Somerville work I + + align:start position:0% +I we did the Cambridge Somerville work I + + + align:start position:0% +I we did the Cambridge Somerville work I +thought we got to scale this up somehow + + align:start position:0% +thought we got to scale this up somehow + + + align:start position:0% +thought we got to scale this up somehow +I found some arcane data on the + + align:start position:0% +I found some arcane data on the + + + align:start position:0% +I found some arcane data on the +Department of Public Utilities site + + align:start position:0% +Department of Public Utilities site + + + align:start position:0% +Department of Public Utilities site +where they have to give a lot of + + align:start position:0% +where they have to give a lot of + + + align:start position:0% +where they have to give a lot of +information and including this which + + align:start position:0% +information and including this which + + + align:start position:0% +information and including this which +like over 300 pages of this sort of + + align:start position:0% +like over 300 pages of this sort of + + + align:start position:0% +like over 300 pages of this sort of +stuff but you'll see that there's + + align:start position:0% +stuff but you'll see that there's + + + align:start position:0% +stuff but you'll see that there's +actually addresses there so as soon as I + + align:start position:0% +actually addresses there so as soon as I + + + align:start position:0% +actually addresses there so as soon as I +saw that there were addresses showing + + align:start position:0% +saw that there were addresses showing + + + align:start position:0% +saw that there were addresses showing +where the leaks were I thought cool I + + align:start position:0% +where the leaks were I thought cool I + + + align:start position:0% +where the leaks were I thought cool I +can map it so I mapped every gas leak in + + align:start position:0% +can map it so I mapped every gas leak in + + + align:start position:0% +can map it so I mapped every gas leak in +Massachusetts on Google Maps so there is + + align:start position:0% +Massachusetts on Google Maps so there is + + + align:start position:0% +Massachusetts on Google Maps so there is +Uma Bowl anybody can see them at squeaky + + align:start position:0% +Uma Bowl anybody can see them at squeaky + + + align:start position:0% +Uma Bowl anybody can see them at squeaky +leak dot org the yellow map pins are + + align:start position:0% +leak dot org the yellow map pins are + + + align:start position:0% +leak dot org the yellow map pins are +where the leaks are unrepaired and the + + align:start position:0% +where the leaks are unrepaired and the + + + align:start position:0% +where the leaks are unrepaired and the +Reds are where they were repaired the + + align:start position:0% +Reds are where they were repaired the + + + align:start position:0% +Reds are where they were repaired the +previous year and there's just a lot + + align:start position:0% +previous year and there's just a lot + + + align:start position:0% +previous year and there's just a lot +them and this was some of the you know + + align:start position:0% +them and this was some of the you know + + + align:start position:0% +them and this was some of the you know +really transformative for a lot of + + align:start position:0% +really transformative for a lot of + + + align:start position:0% +really transformative for a lot of +people because then they could actually + + align:start position:0% +people because then they could actually + + + align:start position:0% +people because then they could actually +see where the where the leaks were near + + align:start position:0% +see where the where the leaks were near + + + align:start position:0% +see where the where the leaks were near +their home near their kids school near + + align:start position:0% +their home near their kids school near + + + align:start position:0% +their home near their kids school near +their business etc it made the not only + + align:start position:0% +their business etc it made the not only + + + align:start position:0% +their business etc it made the not only +invisible visible but it also made the + + align:start position:0% +invisible visible but it also made the + + + align:start position:0% +invisible visible but it also made the +local the global local and then I'll + + align:start position:0% +local the global local and then I'll + + + align:start position:0% +local the global local and then I'll +finally finish up with one last thing + + align:start position:0% +finally finish up with one last thing + + + align:start position:0% +finally finish up with one last thing +which is some other parts of Nathan's + + align:start position:0% +which is some other parts of Nathan's + + + align:start position:0% +which is some other parts of Nathan's +research as well as Margaret Hendrick + + align:start position:0% +research as well as Margaret Hendrick + + + align:start position:0% +research as well as Margaret Hendrick +who is graduate student that + + align:start position:0% +who is graduate student that + + + align:start position:0% +who is graduate student that +postdoctoral student that field is they + + align:start position:0% +postdoctoral student that field is they + + + align:start position:0% +postdoctoral student that field is they +surveyed 100 gas leaks in Boston to find + + align:start position:0% +surveyed 100 gas leaks in Boston to find + + + align:start position:0% +surveyed 100 gas leaks in Boston to find +that just 7% of them emit 50 percent of + + align:start position:0% +that just 7% of them emit 50 percent of + + + align:start position:0% +that just 7% of them emit 50 percent of +the gas by volume so that means as soon + + align:start position:0% +the gas by volume so that means as soon + + + align:start position:0% +the gas by volume so that means as soon +as you know that you know ok the whole + + align:start position:0% +as you know that you know ok the whole + + + align:start position:0% +as you know that you know ok the whole +thing is to fix find and fix those leaks + + align:start position:0% +thing is to fix find and fix those leaks + + + align:start position:0% +thing is to fix find and fix those leaks +so by through a lot of work through all + + align:start position:0% +so by through a lot of work through all + + + align:start position:0% +so by through a lot of work through all +the different people who are interested + + align:start position:0% +the different people who are interested + + + align:start position:0% +the different people who are interested +in this we managed to get we helped to + + align:start position:0% +in this we managed to get we helped to + + + align:start position:0% +in this we managed to get we helped to +get a state law passed that those leaks + + align:start position:0% +get a state law passed that those leaks + + + align:start position:0% +get a state law passed that those leaks +will have to be found and fixed and so + + align:start position:0% +will have to be found and fixed and so + + + align:start position:0% +will have to be found and fixed and so +one of the things we're going to be + + align:start position:0% +one of the things we're going to be + + + align:start position:0% +one of the things we're going to be +doing is at the hackathon will hopefully + + align:start position:0% +doing is at the hackathon will hopefully + + + align:start position:0% +doing is at the hackathon will hopefully +be trying to figure out a method for + + align:start position:0% +be trying to figure out a method for + + + align:start position:0% +be trying to figure out a method for +that's utility friendly for the + + align:start position:0% +that's utility friendly for the + + + align:start position:0% +that's utility friendly for the +utilities to measure the emissions off + + align:start position:0% +utilities to measure the emissions off + + + align:start position:0% +utilities to measure the emissions off +of each one of these + + align:start position:0% +of each one of these + + + align:start position:0% +of each one of these +theoretically high volume leaks does + + align:start position:0% +theoretically high volume leaks does + + + align:start position:0% +theoretically high volume leaks does +that so that because if we don't have + + align:start position:0% +that so that because if we don't have + + + align:start position:0% +that so that because if we don't have +feedback for the system they're probably + + align:start position:0% +feedback for the system they're probably + + + align:start position:0% +feedback for the system they're probably +going to find whatever leaks are + + align:start position:0% +going to find whatever leaks are + + + align:start position:0% +going to find whatever leaks are +convenient + + align:start position:0% +convenient + + + align:start position:0% +convenient +and call those high-volume and fix them + + align:start position:0% +and call those high-volume and fix them + + + align:start position:0% +and call those high-volume and fix them +because they don't know how to do it yet + + align:start position:0% +because they don't know how to do it yet + + + align:start position:0% +because they don't know how to do it yet +nobody does how to find the leaks yeah + + align:start position:0% +nobody does how to find the leaks yeah + + + align:start position:0% +nobody does how to find the leaks yeah +if you check the response of a national + + align:start position:0% +if you check the response of a national + + + align:start position:0% +if you check the response of a national +grid of utilities like the capacity to + + align:start position:0% + + + + align:start position:0% + +and also we compare that to the new + + align:start position:0% +and also we compare that to the new + + + align:start position:0% +and also we compare that to the new +leaks the diversion + + align:start position:0% + + + + align:start position:0% + +yeah I met with a lot with a lot of + + align:start position:0% +yeah I met with a lot with a lot of + + + align:start position:0% +yeah I met with a lot with a lot of +other people I met with National Grid on + + align:start position:0% +other people I met with National Grid on + + + align:start position:0% +other people I met with National Grid on +on Friday they say they will they've + + align:start position:0% +on Friday they say they will they've + + + align:start position:0% +on Friday they say they will they've +hired a whole bunch new people and they + + align:start position:0% +hired a whole bunch new people and they + + + align:start position:0% +hired a whole bunch new people and they +say they will have the capacity to do + + align:start position:0% +say they will have the capacity to do + + + align:start position:0% +say they will have the capacity to do +this to fix all these leaks but what I + + align:start position:0% +this to fix all these leaks but what I + + + align:start position:0% +this to fix all these leaks but what I +want them to do is be transparent about + + align:start position:0% +want them to do is be transparent about + + + align:start position:0% +want them to do is be transparent about +their information so that anybody so + + align:start position:0% +their information so that anybody so + + + align:start position:0% +their information so that anybody so +anybody can check that they fix the + + align:start position:0% +anybody can check that they fix the + + + align:start position:0% +anybody can check that they fix the +right leaks that the leaks were fix that + + align:start position:0% +right leaks that the leaks were fix that + + + align:start position:0% +right leaks that the leaks were fix that +you know so on and so forth because the + + align:start position:0% +you know so on and so forth because the + + + align:start position:0% +you know so on and so forth because the +more transparency we have the more + + align:start position:0% +more transparency we have the more + + + align:start position:0% +more transparency we have the more +researchers can look at stuff and + + align:start position:0% +researchers can look at stuff and + + + align:start position:0% +researchers can look at stuff and +citizens can to know in this case I was + + align:start position:0% +citizens can to know in this case I was + + + align:start position:0% +citizens can to know in this case I was +mapping the the red the pink ones are + + align:start position:0% +mapping the the red the pink ones are + + + align:start position:0% +mapping the the red the pink ones are +super matters the the high volume gas + + align:start position:0% +super matters the the high volume gas + + + align:start position:0% +super matters the the high volume gas +leaks the yellow ones are not they're + + align:start position:0% +leaks the yellow ones are not they're + + + align:start position:0% +leaks the yellow ones are not they're +just normal gas leaks + + align:start position:0% +just normal gas leaks + + + align:start position:0% +just normal gas leaks +maybe I'll just add something about the + + align:start position:0% +maybe I'll just add something about the + + + align:start position:0% +maybe I'll just add something about the +opportunities for just being creative + + align:start position:0% +opportunities for just being creative + + + align:start position:0% +opportunities for just being creative +here and and I think it just this is + + align:start position:0% +here and and I think it just this is + + + align:start position:0% +here and and I think it just this is +embodied by the collaboration that + + align:start position:0% +embodied by the collaboration that + + + align:start position:0% +embodied by the collaboration that +Audrey and I have so well was to do this + + align:start position:0% +Audrey and I have so well was to do this + + + align:start position:0% +Audrey and I have so well was to do this +study we had to think of methods that + + align:start position:0% +study we had to think of methods that + + + align:start position:0% +study we had to think of methods that +were a little out of the box a little + + align:start position:0% +were a little out of the box a little + + + align:start position:0% +were a little out of the box a little +bit about for to found objects + + align:start position:0% +bit about for to found objects + + + align:start position:0% +bit about for to found objects +fortuitous because there's no real kit + + align:start position:0% +fortuitous because there's no real kit + + + align:start position:0% +fortuitous because there's no real kit +to measure gas leaks that you can buy + + align:start position:0% +to measure gas leaks that you can buy + + + align:start position:0% +to measure gas leaks that you can buy +from some instant we were making this up + + align:start position:0% +from some instant we were making this up + + + align:start position:0% +from some instant we were making this up +as we go so for example we found out + + align:start position:0% +as we go so for example we found out + + + align:start position:0% +as we go so for example we found out +that the best kind of chamber to measure + + align:start position:0% +that the best kind of chamber to measure + + + align:start position:0% +that the best kind of chamber to measure +what's coming out of manholes is a + + align:start position:0% +what's coming out of manholes is a + + + align:start position:0% +what's coming out of manholes is a +turtle shell from a sand box because it + + align:start position:0% +turtle shell from a sand box because it + + + align:start position:0% +turtle shell from a sand box because it +fits right over and it + + align:start position:0% +fits right over and it + + + align:start position:0% +fits right over and it +it's a known volume and you get that for + + align:start position:0% +it's a known volume and you get that for + + + align:start position:0% +it's a known volume and you get that for +20 bucks instead of having a machine + + align:start position:0% +20 bucks instead of having a machine + + + align:start position:0% +20 bucks instead of having a machine +shop make it for $1000 right so so it's + + align:start position:0% +shop make it for $1000 right so so it's + + + align:start position:0% +shop make it for $1000 right so so it's +there's that level of creativity and + + align:start position:0% +there's that level of creativity and + + + align:start position:0% +there's that level of creativity and +just yesterday Audrey came up with the + + align:start position:0% +just yesterday Audrey came up with the + + + align:start position:0% +just yesterday Audrey came up with the +use of a pin wheel that might be able to + + align:start position:0% +use of a pin wheel that might be able to + + + align:start position:0% +use of a pin wheel that might be able to +mix the air that we need to measure and + + align:start position:0% +mix the air that we need to measure and + + + align:start position:0% +mix the air that we need to measure and +it's the kind of thing that it's like + + align:start position:0% +it's the kind of thing that it's like + + + align:start position:0% +it's the kind of thing that it's like +once she said that I was like yeah + + align:start position:0% +once she said that I was like yeah + + + align:start position:0% +once she said that I was like yeah +perfect you know then we'll so I think + + align:start position:0% +perfect you know then we'll so I think + + + align:start position:0% +perfect you know then we'll so I think +in the hackathon that there will be + + align:start position:0% +in the hackathon that there will be + + + align:start position:0% +in the hackathon that there will be +opportunities to think about how we + + align:start position:0% +opportunities to think about how we + + + align:start position:0% +opportunities to think about how we +might go about doing something in a + + align:start position:0% +might go about doing something in a + + + align:start position:0% +might go about doing something in a +cost-effective way without doing it kind + + align:start position:0% +cost-effective way without doing it kind + + + align:start position:0% +cost-effective way without doing it kind +of like you know NASA does in their you + + align:start position:0% +of like you know NASA does in their you + + + align:start position:0% +of like you know NASA does in their you +know multi-million dollar laboratories + + align:start position:0% +know multi-million dollar laboratories + + + align:start position:0% +know multi-million dollar laboratories +did you find you had your test going on + + align:start position:0% +did you find you had your test going on + + + align:start position:0% +did you find you had your test going on +with the truck and then you have the GPU + + align:start position:0% +with the truck and then you have the GPU + + + align:start position:0% +with the truck and then you have the GPU +did you find any leaks that were not on + + align:start position:0% +did you find any leaks that were not on + + + align:start position:0% +did you find any leaks that were not on +the + + align:start position:0% +the + + + align:start position:0% +the +oh yeah they're with with Metropolitan + + align:start position:0% +oh yeah they're with with Metropolitan + + + align:start position:0% +oh yeah they're with with Metropolitan +Area Planning Council heat my nonprofit + + align:start position:0% +Area Planning Council heat my nonprofit + + + align:start position:0% +Area Planning Council heat my nonprofit +has done a survey of 15 different + + align:start position:0% +has done a survey of 15 different + + + align:start position:0% +has done a survey of 15 different +municipalities and we found that the you + + align:start position:0% +municipalities and we found that the you + + + align:start position:0% +municipalities and we found that the you +are we found one point seven times more + + align:start position:0% +are we found one point seven times more + + + align:start position:0% +are we found one point seven times more +leaks than the utilities reported and + + align:start position:0% +leaks than the utilities reported and + + + align:start position:0% +leaks than the utilities reported and +there's lots of other stuff that we + + align:start position:0% +there's lots of other stuff that we + + + align:start position:0% +there's lots of other stuff that we +found that makes us question the utility + + align:start position:0% +found that makes us question the utility + + + align:start position:0% +found that makes us question the utility +data + + align:start position:0% + + + + align:start position:0% + +perfect question + + align:start position:0% + + + + align:start position:0% + +know where the Super Readers + + align:start position:0% + + + + align:start position:0% + +so so we did the survey the driving + + align:start position:0% +so so we did the survey the driving + + + align:start position:0% +so so we did the survey the driving +survey that measured 3356 links in + + align:start position:0% +survey that measured 3356 links in + + + align:start position:0% +survey that measured 3356 links in +Boston but that's just detecting leads + + align:start position:0% +Boston but that's just detecting leads + + + align:start position:0% +Boston but that's just detecting leads +that doesn't tell us how much is coming + + align:start position:0% +that doesn't tell us how much is coming + + + align:start position:0% +that doesn't tell us how much is coming +out so then subsequent complete to that + + align:start position:0% +out so then subsequent complete to that + + + align:start position:0% +out so then subsequent complete to that +we went out with these chambers some of + + align:start position:0% +we went out with these chambers some of + + + align:start position:0% +we went out with these chambers some of +them were the turtle shell some of them + + align:start position:0% +them were the turtle shell some of them + + + align:start position:0% +them were the turtle shell some of them +were five gallon buckets with a slot cut + + align:start position:0% +were five gallon buckets with a slot cut + + + align:start position:0% +were five gallon buckets with a slot cut +out so it could go up to a curb because + + align:start position:0% +out so it could go up to a curb because + + + align:start position:0% +out so it could go up to a curb because +sometimes it comes out of these complex + + align:start position:0% +sometimes it comes out of these complex + + + align:start position:0% +sometimes it comes out of these complex +you know geometries and so we we did the + + align:start position:0% +you know geometries and so we we did the + + + align:start position:0% +you know geometries and so we we did the +laborious task up going back to a + + align:start position:0% +laborious task up going back to a + + + align:start position:0% +laborious task up going back to a +hundred of those 3356 leaks and + + align:start position:0% +hundred of those 3356 leaks and + + + align:start position:0% +hundred of those 3356 leaks and +measuring how much is coming out using + + align:start position:0% +measuring how much is coming out using + + + align:start position:0% +measuring how much is coming out using +this chamber technique and from that the + + align:start position:0% +this chamber technique and from that the + + + align:start position:0% +this chamber technique and from that the +statistics of those hundred leaks show + + align:start position:0% +statistics of those hundred leaks show + + + align:start position:0% +statistics of those hundred leaks show +that seven of them accounted for 50% of + + align:start position:0% +that seven of them accounted for 50% of + + + align:start position:0% +that seven of them accounted for 50% of +the total lost gas I know + + align:start position:0% +the total lost gas I know + + + align:start position:0% +the total lost gas I know +so you've done example but not in any + + align:start position:0% +so you've done example but not in any + + + align:start position:0% +so you've done example but not in any +regard exactly yeah it might be more + + align:start position:0% +regard exactly yeah it might be more + + + align:start position:0% +regard exactly yeah it might be more +like if we did the whole thing over + + align:start position:0% +like if we did the whole thing over + + + align:start position:0% +like if we did the whole thing over +again maybe you know another hundred + + align:start position:0% +again maybe you know another hundred + + + align:start position:0% +again maybe you know another hundred +leaks it may be that 10 of them + + align:start position:0% +leaks it may be that 10 of them + + + align:start position:0% +leaks it may be that 10 of them +accounted for 50% or maybe six sample + + align:start position:0% +accounted for 50% or maybe six sample + + + align:start position:0% +accounted for 50% or maybe six sample +right it was a sample right so it's a + + align:start position:0% +right it was a sample right so it's a + + + align:start position:0% +right it was a sample right so it's a +kind of a rough we know that it's not + + align:start position:0% +kind of a rough we know that it's not + + + align:start position:0% +kind of a rough we know that it's not +like a bell-shaped curve and you've got + + align:start position:0% +like a bell-shaped curve and you've got + + + align:start position:0% +like a bell-shaped curve and you've got +an average league and some are a little + + align:start position:0% +an average league and some are a little + + + align:start position:0% +an average league and some are a little +bit higher and somewhere in a bit lower + + align:start position:0% +bit higher and somewhere in a bit lower + + + align:start position:0% +bit higher and somewhere in a bit lower +the distribution is a long tail there's + + align:start position:0% +the distribution is a long tail there's + + + align:start position:0% +the distribution is a long tail there's +a few big ones + + align:start position:0% + + + + align:start position:0% + +but it's true in one town that I was + + align:start position:0% +but it's true in one town that I was + + + align:start position:0% +but it's true in one town that I was +working with + + align:start position:0% +working with + + + align:start position:0% +working with +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +the report was that when they had a gas + + align:start position:0% +the report was that when they had a gas + + + align:start position:0% +the report was that when they had a gas +leak and assistant complained enough + + align:start position:0% +leak and assistant complained enough + + + align:start position:0% +leak and assistant complained enough +that they would actually come out and + + align:start position:0% +that they would actually come out and + + + align:start position:0% +that they would actually come out and +fix the leak but they didn't fix it + + align:start position:0% +fix the leak but they didn't fix it + + + align:start position:0% +fix the leak but they didn't fix it +well first time they sometimes have to + + align:start position:0% +well first time they sometimes have to + + + align:start position:0% +well first time they sometimes have to +come back and do it like five times and + + align:start position:0% +come back and do it like five times and + + + align:start position:0% +come back and do it like five times and +the reason for that is that the gas + + align:start position:0% +the reason for that is that the gas + + + align:start position:0% +the reason for that is that the gas +companies get paid based on the amount + + align:start position:0% +companies get paid based on the amount + + + align:start position:0% +companies get paid based on the amount +of work that they do so if they do the + + align:start position:0% +of work that they do so if they do the + + + align:start position:0% +of work that they do so if they do the +same work over and over again they get + + align:start position:0% +same work over and over again they get + + + align:start position:0% +same work over and over again they get +paid time for so that you're engaging in + + align:start position:0% +paid time for so that you're engaging in + + + align:start position:0% +paid time for so that you're engaging in +this sort of measuring and monitoring I + + align:start position:0% +this sort of measuring and monitoring I + + + align:start position:0% +this sort of measuring and monitoring I +do completely agree with the fact that + + align:start position:0% +do completely agree with the fact that + + + align:start position:0% +do completely agree with the fact that +some amount of + + align:start position:0% +some amount of + + + align:start position:0% +some amount of +of oversight or review or checking up on + + align:start position:0% +of oversight or review or checking up on + + + align:start position:0% +of oversight or review or checking up on +one that they say + + align:start position:0% +one that they say + + + align:start position:0% +one that they say +Thanks + + align:start position:0% + + + + align:start position:0% + +yeah I think transparency and and + + align:start position:0% +yeah I think transparency and and + + + align:start position:0% +yeah I think transparency and and +watchdogs are good for any industry + + align:start position:0% + + + + align:start position:0% + +if you projected just you know in a + + align:start position:0% +if you projected just you know in a + + + align:start position:0% +if you projected just you know in a +dreamlike way how much gas could be so + + align:start position:0% +dreamlike way how much gas could be so + + + align:start position:0% +dreamlike way how much gas could be so +the best estimates that we have for the + + align:start position:0% +the best estimates that we have for the + + + align:start position:0% +the best estimates that we have for the +amount of lost gas comes from a study + + align:start position:0% +amount of lost gas comes from a study + + + align:start position:0% +amount of lost gas comes from a study +that we did in collaboration with + + align:start position:0% +that we did in collaboration with + + + align:start position:0% +that we did in collaboration with +Harvard University after McCain Steve + + align:start position:0% +Harvard University after McCain Steve + + + align:start position:0% +Harvard University after McCain Steve +Ozzie and their lab and we asked maybe + + align:start position:0% +Ozzie and their lab and we asked maybe + + + align:start position:0% +Ozzie and their lab and we asked maybe +that a little less than three percent of + + align:start position:0% +that a little less than three percent of + + + align:start position:0% +that a little less than three percent of +the amount of gas that's delivered into + + align:start position:0% +the amount of gas that's delivered into + + + align:start position:0% +the amount of gas that's delivered into +the service area is leaked out so that + + align:start position:0% +the service area is leaked out so that + + + align:start position:0% +the service area is leaked out so that +may not sound like a lot you know three + + align:start position:0% +may not sound like a lot you know three + + + align:start position:0% +may not sound like a lot you know three +percent but because of the power of + + align:start position:0% +percent but because of the power of + + + align:start position:0% +percent but because of the power of +methane is a greenhouse gas it has an + + align:start position:0% +methane is a greenhouse gas it has an + + + align:start position:0% +methane is a greenhouse gas it has an +outsized effect and so that's why that + + align:start position:0% +outsized effect and so that's why that + + + align:start position:0% +outsized effect and so that's why that +three percent turns into about ten + + align:start position:0% +three percent turns into about ten + + + align:start position:0% +three percent turns into about ten +percent of the total Commonwealth's + + align:start position:0% +percent of the total Commonwealth's + + + align:start position:0% +percent of the total Commonwealth's +greenhouse gas emissions inventory at + + align:start position:0% +greenhouse gas emissions inventory at + + + align:start position:0% +greenhouse gas emissions inventory at +that level so if you if if you took that + + align:start position:0% +that level so if you if if you took that + + + align:start position:0% +that level so if you if if you took that +three percent leak gas down to zero you + + align:start position:0% +three percent leak gas down to zero you + + + align:start position:0% +three percent leak gas down to zero you +would say that Commonwealth with 10% of + + align:start position:0% +would say that Commonwealth with 10% of + + + align:start position:0% +would say that Commonwealth with 10% of +its greenhouse gas emissions inventory + + align:start position:0% +its greenhouse gas emissions inventory + + + align:start position:0% +its greenhouse gas emissions inventory +and about 90 million dollars per year + + align:start position:0% +and about 90 million dollars per year + + + align:start position:0% +and about 90 million dollars per year +was the America cost of the commodity at + + align:start position:0% +was the America cost of the commodity at + + + align:start position:0% +was the America cost of the commodity at +the time that the study was done its gas + + align:start position:0% +the time that the study was done its gas + + + align:start position:0% +the time that the study was done its gas +is volatile so that number changes but + + align:start position:0% +is volatile so that number changes but + + + align:start position:0% +is volatile so that number changes but +there's another observation in that + + align:start position:0% +there's another observation in that + + + align:start position:0% +there's another observation in that +which is that 3% but itself would reduce + + align:start position:0% +which is that 3% but itself would reduce + + + align:start position:0% +which is that 3% but itself would reduce +the heat flow demand for gas on 3% + + align:start position:0% +the heat flow demand for gas on 3% + + + align:start position:0% +the heat flow demand for gas on 3% +and when they talk about new pipelines + + align:start position:0% +and when they talk about new pipelines + + + align:start position:0% +and when they talk about new pipelines +they're increasingly talking about just + + align:start position:0% +they're increasingly talking about just + + + align:start position:0% +they're increasingly talking about just +a 5% deficiency + + align:start position:0% +a 5% deficiency + + + align:start position:0% +a 5% deficiency +in our peak load capacity + + align:start position:0% + + + + align:start position:0% + +indicate + + align:start position:0% +indicate + + + align:start position:0% +indicate +supposedly + + align:start position:0% + + + + align:start position:0% + +that is an excellent excellent point + + align:start position:0% +that is an excellent excellent point + + + align:start position:0% +that is an excellent excellent point +yeah + + align:start position:0% + + + + align:start position:0% + +what do you have a problem of how you + + align:start position:0% +what do you have a problem of how you + + + align:start position:0% +what do you have a problem of how you +put all these dollars together because + + align:start position:0% +put all these dollars together because + + + align:start position:0% +put all these dollars together because +dollars that I understand here is paying + + align:start position:0% +dollars that I understand here is paying + + + align:start position:0% +dollars that I understand here is paying +the the gas that we don't know about + + align:start position:0% +the the gas that we don't know about + + + align:start position:0% +the the gas that we don't know about +we don't know + + align:start position:0% +we don't know + + + align:start position:0% +we don't know +and then there is fun that they have + + align:start position:0% +and then there is fun that they have + + + align:start position:0% +and then there is fun that they have +fixing + + align:start position:0% +fixing + + + align:start position:0% +fixing +and then there's the amount of money + + align:start position:0% +and then there's the amount of money + + + align:start position:0% +and then there's the amount of money +that they're using for developing a new + + align:start position:0% +that they're using for developing a new + + + align:start position:0% +that they're using for developing a new +pipeline and those are all coming out of + + align:start position:0% +pipeline and those are all coming out of + + + align:start position:0% +pipeline and those are all coming out of +different pocketbooks and it seemed that + + align:start position:0% +different pocketbooks and it seemed that + + + align:start position:0% +different pocketbooks and it seemed that +if you don't figure out how to put them + + align:start position:0% +if you don't figure out how to put them + + + align:start position:0% +if you don't figure out how to put them +together about okay stop making them pay + + align:start position:0% +together about okay stop making them pay + + + align:start position:0% +together about okay stop making them pay +ninety million dollars for weights + + align:start position:0% +ninety million dollars for weights + + + align:start position:0% +ninety million dollars for weights +gasps let's use an item in a million + + align:start position:0% +gasps let's use an item in a million + + + align:start position:0% +gasps let's use an item in a million +dollars and fix leaks and then don't use + + align:start position:0% +dollars and fix leaks and then don't use + + + align:start position:0% +dollars and fix leaks and then don't use +the money that we're going to build a + + align:start position:0% +the money that we're going to build a + + + align:start position:0% +the money that we're going to build a +pipeline or fix at least so happy + + align:start position:0% +pipeline or fix at least so happy + + + align:start position:0% +pipeline or fix at least so happy +because it's all about money at the end + + align:start position:0% +because it's all about money at the end + + + align:start position:0% +because it's all about money at the end +of the day it's all anybody cares about + + align:start position:0% + + + + align:start position:0% + +well so if you thought about how + + align:start position:0% + + + + align:start position:0% + +huh I one of the things well no I mean + + align:start position:0% +huh I one of the things well no I mean + + + align:start position:0% +huh I one of the things well no I mean +one of the things I think that's been + + align:start position:0% +one of the things I think that's been + + + align:start position:0% +one of the things I think that's been +there would be most effective is if the + + align:start position:0% +there would be most effective is if the + + + align:start position:0% +there would be most effective is if the +utilities had to pay for the cost of the + + align:start position:0% +utilities had to pay for the cost of the + + + align:start position:0% +utilities had to pay for the cost of the +last of the lost gas if they did you + + align:start position:0% +last of the lost gas if they did you + + + align:start position:0% +last of the lost gas if they did you +know as soon as they did I think we'd + + align:start position:0% +know as soon as they did I think we'd + + + align:start position:0% +know as soon as they did I think we'd +see it a massive amount of repair + + align:start position:0% +see it a massive amount of repair + + + align:start position:0% +see it a massive amount of repair +happening a hell of a lot faster that + + align:start position:0% +happening a hell of a lot faster that + + + align:start position:0% +happening a hell of a lot faster that +that's what happened in in Texas they + + align:start position:0% +that's what happened in in Texas they + + + align:start position:0% +that's what happened in in Texas they +passed a law saying that and within and + + align:start position:0% +passed a law saying that and within and + + + align:start position:0% +passed a law saying that and within and +I'm gonna get this wrong that within + + align:start position:0% +I'm gonna get this wrong that within + + + align:start position:0% +I'm gonna get this wrong that within +three years they had 50% of the leaks + + align:start position:0% +three years they had 50% of the leaks + + + align:start position:0% +three years they had 50% of the leaks +fixed so it's it's just incentives what + + align:start position:0% +fixed so it's it's just incentives what + + + align:start position:0% +fixed so it's it's just incentives what +I heard was on this day that the + + align:start position:0% +I heard was on this day that the + + + align:start position:0% +I heard was on this day that the +legislature lived the end of the + + align:start position:0% +legislature lived the end of the + + + align:start position:0% +legislature lived the end of the +legislative session last year when the + + align:start position:0% +legislative session last year when the + + + align:start position:0% +legislative session last year when the +energy omnibus bill was finally passed + + align:start position:0% +energy omnibus bill was finally passed + + + align:start position:0% +energy omnibus bill was finally passed +if after whatever two o'clock good + + align:start position:0% +if after whatever two o'clock good + + + align:start position:0% +if after whatever two o'clock good +morning you know a lot of I think that's + + align:start position:0% +morning you know a lot of I think that's + + + align:start position:0% +morning you know a lot of I think that's +when the provision that would include + + align:start position:0% +when the provision that would include + + + align:start position:0% +when the provision that would include +the incentives we thought that the cost + + align:start position:0% +the incentives we thought that the cost + + + align:start position:0% +the incentives we thought that the cost +of the lost gas gets shifted to the + + align:start position:0% +of the lost gas gets shifted to the + + + align:start position:0% +of the lost gas gets shifted to the +companies was gone so there's a lot of + + align:start position:0% +companies was gone so there's a lot of + + + align:start position:0% +companies was gone so there's a lot of +lobbying going on over who's paying for + + align:start position:0% +lobbying going on over who's paying for + + + align:start position:0% +lobbying going on over who's paying for +the loft gasps that's a problem but wait + + align:start position:0% +the loft gasps that's a problem but wait + + + align:start position:0% +the loft gasps that's a problem but wait +you say that's a person start start by + + align:start position:0% +you say that's a person start start by + + + align:start position:0% +you say that's a person start start by +not + + align:start position:0% +not + + + align:start position:0% +not +big place + + align:start position:0% +big place + + + align:start position:0% +big place +c'est raté here's you keep it in your + + align:start position:0% +c'est raté here's you keep it in your + + + align:start position:0% +c'est raté here's you keep it in your +pocket and now the gas that was paying + + align:start position:0% +pocket and now the gas that was paying + + + align:start position:0% +pocket and now the gas that was paying +that's a really simple any legislator to + + align:start position:0% +that's a really simple any legislator to + + + align:start position:0% +that's a really simple any legislator to +figure that out for a member + + align:start position:0% + + + + align:start position:0% + +that was the provision guys yep + + align:start position:0% +that was the provision guys yep + + + align:start position:0% +that was the provision guys yep +so with the infrastructure being this + + align:start position:0% +so with the infrastructure being this + + + align:start position:0% +so with the infrastructure being this +old I'm worried that if you fix the + + align:start position:0% +old I'm worried that if you fix the + + + align:start position:0% +old I'm worried that if you fix the +leaks in one spot because it's opposed + + align:start position:0% +leaks in one spot because it's opposed + + + align:start position:0% +leaks in one spot because it's opposed +due to pressure the work of this + + align:start position:0% +due to pressure the work of this + + + align:start position:0% +due to pressure the work of this +creative believes in other spots and so + + align:start position:0% +creative believes in other spots and so + + + align:start position:0% +creative believes in other spots and so +we so it has there been any study what + + align:start position:0% +we so it has there been any study what + + + align:start position:0% +we so it has there been any study what +happened we both get an answer I think I + + align:start position:0% +happened we both get an answer I think I + + + align:start position:0% +happened we both get an answer I think I +think I think like a lot in Boston a lot + + align:start position:0% +think I think like a lot in Boston a lot + + + align:start position:0% +think I think like a lot in Boston a lot +of the pressure in the pipes is about + + align:start position:0% +of the pressure in the pipes is about + + + align:start position:0% +of the pressure in the pipes is about +half pound per square inch so fixing a + + align:start position:0% +half pound per square inch so fixing a + + + align:start position:0% +half pound per square inch so fixing a +leak in one spot is really not gonna + + align:start position:0% +leak in one spot is really not gonna + + + align:start position:0% +leak in one spot is really not gonna +make any discernible difference and that + + align:start position:0% +make any discernible difference and that + + + align:start position:0% +make any discernible difference and that +the you know the pressure is supposed to + + align:start position:0% +the you know the pressure is supposed to + + + align:start position:0% +the you know the pressure is supposed to +be maintained you know evenly across the + + align:start position:0% +be maintained you know evenly across the + + + align:start position:0% +be maintained you know evenly across the +system otherwise the people at the end + + align:start position:0% +system otherwise the people at the end + + + align:start position:0% +system otherwise the people at the end +of the line would not be getting any gas + + align:start position:0% +of the line would not be getting any gas + + + align:start position:0% +of the line would not be getting any gas +so there is the question that like + + align:start position:0% +so there is the question that like + + + align:start position:0% +so there is the question that like +hammering into the ground and moving + + align:start position:0% +hammering into the ground and moving + + + align:start position:0% +hammering into the ground and moving +stuff could potentially displace a + + align:start position:0% +stuff could potentially displace a + + + align:start position:0% +stuff could potentially displace a +little bit of you know move the joint of + + align:start position:0% +little bit of you know move the joint of + + + align:start position:0% +little bit of you know move the joint of +the pipe a teeny bit although I wonder + + align:start position:0% +the pipe a teeny bit although I wonder + + + align:start position:0% +the pipe a teeny bit although I wonder +if that's actually true + + align:start position:0% +if that's actually true + + + align:start position:0% +if that's actually true +yes it's a regulated system so if you + + align:start position:0% +yes it's a regulated system so if you + + + align:start position:0% +yes it's a regulated system so if you +passively they're just gonna turn down + + align:start position:0% +passively they're just gonna turn down + + + align:start position:0% +passively they're just gonna turn down +the flow to maintain it so it's not + + align:start position:0% +the flow to maintain it so it's not + + + align:start position:0% +the flow to maintain it so it's not +gonna induce a higher rate elsewhere but + + align:start position:0% +gonna induce a higher rate elsewhere but + + + align:start position:0% +gonna induce a higher rate elsewhere but +it is a band-aid solution to patch + + align:start position:0% +it is a band-aid solution to patch + + + align:start position:0% +it is a band-aid solution to patch +because every 12 feet on a cast-iron + + align:start position:0% +because every 12 feet on a cast-iron + + + align:start position:0% +because every 12 feet on a cast-iron +pipe is a joint and you often have a + + align:start position:0% +pipe is a joint and you often have a + + + align:start position:0% +pipe is a joint and you often have a +series of leaks so then your rate then + + align:start position:0% +series of leaks so then your rate then + + + align:start position:0% +series of leaks so then your rate then +you're facing the question do you repair + + align:start position:0% +you're facing the question do you repair + + + align:start position:0% +you're facing the question do you repair +or replace and there's a whole other set + + align:start position:0% +or replace and there's a whole other set + + + align:start position:0% +or replace and there's a whole other set +of considerations in terms of money and + + align:start position:0% +of considerations in terms of money and + + + align:start position:0% +of considerations in terms of money and +cost and and I'm still very ambivalent + + align:start position:0% +cost and and I'm still very ambivalent + + + align:start position:0% +cost and and I'm still very ambivalent +about whether we should triage the + + align:start position:0% +about whether we should triage the + + + align:start position:0% +about whether we should triage the +system that we have as we transition to + + align:start position:0% +system that we have as we transition to + + + align:start position:0% +system that we have as we transition to +electrifying our heating system + + align:start position:0% +electrifying our heating system + + + align:start position:0% +electrifying our heating system +in the transition to a clean energy the + + align:start position:0% +in the transition to a clean energy the + + + align:start position:0% +in the transition to a clean energy the +non-fossil energy or do we actually + + align:start position:0% +non-fossil energy or do we actually + + + align:start position:0% +non-fossil energy or do we actually +invest in replacing pipes that are going + + align:start position:0% +invest in replacing pipes that are going + + + align:start position:0% +invest in replacing pipes that are going +to be down for another 30 40 50 years so + + align:start position:0% +to be down for another 30 40 50 years so + + + align:start position:0% +to be down for another 30 40 50 years so +it's a tough it's a tough class + + align:start position:0% +it's a tough it's a tough class + + + align:start position:0% +it's a tough it's a tough class +technology they've discussed in + + align:start position:0% +technology they've discussed in + + + align:start position:0% +technology they've discussed in +technology and the composition of pipes + + align:start position:0% +technology and the composition of pipes + + + align:start position:0% +technology and the composition of pipes +do not really I mean plastic is what's + + align:start position:0% +do not really I mean plastic is what's + + + align:start position:0% +do not really I mean plastic is what's +being put down now and it's it's it's + + align:start position:0% +being put down now and it's it's it's + + + align:start position:0% +being put down now and it's it's it's +not leaking because it's new I didn't + + align:start position:0% +not leaking because it's new I didn't + + + align:start position:0% +not leaking because it's new I didn't +they don't really know as far as I know + + align:start position:0% +they don't really know as far as I know + + + align:start position:0% +they don't really know as far as I know +how acids in the soil and weathering and + + align:start position:0% +how acids in the soil and weathering and + + + align:start position:0% +how acids in the soil and weathering and +all of these kinds of things what you + + align:start position:0% +all of these kinds of things what you + + + align:start position:0% +all of these kinds of things what you +know what the influence on the plastic + + align:start position:0% +know what the influence on the plastic + + + align:start position:0% +know what the influence on the plastic +will be there's nothing inherently wrong + + align:start position:0% +will be there's nothing inherently wrong + + + align:start position:0% +will be there's nothing inherently wrong +with cast-iron pipe + + align:start position:0% +with cast-iron pipe + + + align:start position:0% +with cast-iron pipe +except it's old it was new cast-iron + + align:start position:0% +except it's old it was new cast-iron + + + align:start position:0% +except it's old it was new cast-iron +pipe I mean of course that's more energy + + align:start position:0% +pipe I mean of course that's more energy + + + align:start position:0% +pipe I mean of course that's more energy +intensive to me but it's really just the + + align:start position:0% +intensive to me but it's really just the + + + align:start position:0% +intensive to me but it's really just the +age factor I think Oh although I just + + align:start position:0% +age factor I think Oh although I just + + + align:start position:0% +age factor I think Oh although I just +want to say like I keep thinking like + + align:start position:0% +want to say like I keep thinking like + + + align:start position:0% +want to say like I keep thinking like +dentist can come up with stuff that like + + align:start position:0% +dentist can come up with stuff that like + + + align:start position:0% +dentist can come up with stuff that like +can fix teeth that are in you know + + align:start position:0% +can fix teeth that are in you know + + + align:start position:0% +can fix teeth that are in you know +saliva and acidic stuff and with you + + align:start position:0% +saliva and acidic stuff and with you + + + align:start position:0% +saliva and acidic stuff and with you +know under incredible pressure and stuff + + align:start position:0% +know under incredible pressure and stuff + + + align:start position:0% +know under incredible pressure and stuff +like that + + align:start position:0% +like that + + + align:start position:0% +like that +well I can't anybody come up with + + align:start position:0% +well I can't anybody come up with + + + align:start position:0% +well I can't anybody come up with +something that would just coat the pipes + + align:start position:0% +something that would just coat the pipes + + + align:start position:0% +something that would just coat the pipes +on the inside so you know go ahead + + align:start position:0% + + + + align:start position:0% + +how broad a network of people who + + align:start position:0% + + + + align:start position:0% + +uh mostly Massachusetts you know I mean + + align:start position:0% +uh mostly Massachusetts you know I mean + + + align:start position:0% +uh mostly Massachusetts you know I mean +the the study we did in Boston was the + + align:start position:0% +the the study we did in Boston was the + + + align:start position:0% +the the study we did in Boston was the +first study of its kind in the world so + + align:start position:0% +first study of its kind in the world so + + + align:start position:0% +first study of its kind in the world so +so things started bubbling out from here + + align:start position:0% +so things started bubbling out from here + + + align:start position:0% +so things started bubbling out from here +literally I guess but but I think + + align:start position:0% +literally I guess but but I think + + + align:start position:0% +literally I guess but but I think +there's been a very strong what we call + + align:start position:0% +there's been a very strong what we call + + + align:start position:0% +there's been a very strong what we call +the gas leak to allies the working group + + align:start position:0% +the gas leak to allies the working group + + + align:start position:0% +the gas leak to allies the working group +that we have that means that once a + + align:start position:0% +that we have that means that once a + + + align:start position:0% +that we have that means that once a +month or once a week twice a month twice + + align:start position:0% +month or once a week twice a month twice + + + align:start position:0% +month or once a week twice a month twice +a month and is this core group and + + align:start position:0% +a month and is this core group and + + + align:start position:0% +a month and is this core group and +mothers out front has been amazing in + + align:start position:0% +mothers out front has been amazing in + + + align:start position:0% +mothers out front has been amazing in +terms of essentially keeping that in + + align:start position:0% +terms of essentially keeping that in + + + align:start position:0% +terms of essentially keeping that in +growing that network you know you're + + align:start position:0% +growing that network you know you're + + + align:start position:0% +growing that network you know you're +seeing research communities and in other + + align:start position:0% +seeing research communities and in other + + + align:start position:0% +seeing research communities and in other +groups the science community is doing + + align:start position:0% +groups the science community is doing + + + align:start position:0% +groups the science community is doing +this working in other locations I + + align:start position:0% +this working in other locations I + + + align:start position:0% +this working in other locations I +haven't quite seen the the network + + align:start position:0% +haven't quite seen the the network + + + align:start position:0% +haven't quite seen the the network +expand the way it does here but the + + align:start position:0% +expand the way it does here but the + + + align:start position:0% +expand the way it does here but the +other interesting thing I think is that + + align:start position:0% +other interesting thing I think is that + + + align:start position:0% +other interesting thing I think is that +we're also realizing that there's this + + align:start position:0% +we're also realizing that there's this + + + align:start position:0% +we're also realizing that there's this +urban to rural interdependence II and so + + align:start position:0% +urban to rural interdependence II and so + + + align:start position:0% +urban to rural interdependence II and so +the pipeline issues connect us with you + + align:start position:0% +the pipeline issues connect us with you + + + align:start position:0% +the pipeline issues connect us with you +know rural Western Massachusetts and the + + align:start position:0% +know rural Western Massachusetts and the + + + align:start position:0% +know rural Western Massachusetts and the +the Kinder Morgan proposed pipeline + + align:start position:0% +the Kinder Morgan proposed pipeline + + + align:start position:0% +the Kinder Morgan proposed pipeline +going in there the pipeline that + + align:start position:0% +going in there the pipeline that + + + align:start position:0% +going in there the pipeline that +connects us in Boston to New York New + + align:start position:0% +connects us in Boston to New York New + + + align:start position:0% +connects us in Boston to New York New +Jersey Connecticut the Algonquin + + align:start position:0% +Jersey Connecticut the Algonquin + + + align:start position:0% +Jersey Connecticut the Algonquin +incremental market the spectra pipelines + + align:start position:0% +incremental market the spectra pipelines + + + align:start position:0% +incremental market the spectra pipelines +that we are connected across the rural + + align:start position:0% +that we are connected across the rural + + + align:start position:0% +that we are connected across the rural +and urban communities and by the same + + align:start position:0% +and urban communities and by the same + + + align:start position:0% +and urban communities and by the same +infrastructure so I think that the + + align:start position:0% +infrastructure so I think that the + + + align:start position:0% +infrastructure so I think that the +fossil fuel infrastructure expansion + + align:start position:0% +fossil fuel infrastructure expansion + + + align:start position:0% +fossil fuel infrastructure expansion +physically starts to organize a social + + align:start position:0% +physically starts to organize a social + + + align:start position:0% +physically starts to organize a social +network of resistance that is co-located + + align:start position:0% +network of resistance that is co-located + + + align:start position:0% +network of resistance that is co-located +with that and that we're stronger when + + align:start position:0% +with that and that we're stronger when + + + align:start position:0% +with that and that we're stronger when +we as people make the connections that + + align:start position:0% +we as people make the connections that + + + align:start position:0% +we as people make the connections that +are being made physically to resist it + + align:start position:0% +are being made physically to resist it + + + align:start position:0% +are being made physically to resist it +in a conservative + + align:start position:0% + + + + align:start position:0% + +is a new kind of robot that they have + + align:start position:0% +is a new kind of robot that they have + + + align:start position:0% +is a new kind of robot that they have +this is spot science into the pipes + + align:start position:0% +this is spot science into the pipes + + + align:start position:0% +this is spot science into the pipes +inside the bike without + + align:start position:0% + + + + align:start position:0% + +they can excrete they are phenomenally + + align:start position:0% +they can excrete they are phenomenally + + + align:start position:0% +they can excrete they are phenomenally +expensive + + align:start position:0% + + + + align:start position:0% + +you know that struck me when I read + + align:start position:0% +you know that struck me when I read + + + align:start position:0% +you know that struck me when I read +about identity significant ray of hope + + align:start position:0% +about identity significant ray of hope + + + align:start position:0% +about identity significant ray of hope +that technology could once again come to + + align:start position:0% +that technology could once again come to + + + align:start position:0% +that technology could once again come to +the rescue here so to speak we had more + + align:start position:0% +the rescue here so to speak we had more + + + align:start position:0% +the rescue here so to speak we had more +robust than it might be + + align:start position:0% + + + + align:start position:0% + +companies + + align:start position:0% +companies + + + align:start position:0% +companies +now deal with this + + align:start position:0% + + + + align:start position:0% + +yeah I yeah I I that robot they have to + + align:start position:0% +yeah I yeah I I that robot they have to + + + align:start position:0% +yeah I yeah I I that robot they have to +like dig down to put it in and it only + + align:start position:0% +like dig down to put it in and it only + + + align:start position:0% +like dig down to put it in and it only +has a limited expanse so it needs so + + align:start position:0% +has a limited expanse so it needs so + + + align:start position:0% +has a limited expanse so it needs so +much improvement it's stunning to me + + align:start position:0% +much improvement it's stunning to me + + + align:start position:0% +much improvement it's stunning to me +maybe + + align:start position:0% + + + + align:start position:0% + +Toleration company and + + align:start position:0% +Toleration company and + + + align:start position:0% +Toleration company and +my place in the city + + align:start position:0% + + + + align:start position:0% + +we detect a lot legal my time + + align:start position:0% +we detect a lot legal my time + + + align:start position:0% +we detect a lot legal my time +operation and what's really really + + align:start position:0% +operation and what's really really + + + align:start position:0% +operation and what's really really +difficult to solve the crisis + + align:start position:0% +difficult to solve the crisis + + + align:start position:0% +difficult to solve the crisis +Oh easy sometimes you do Nuka missionary + + align:start position:0% +Oh easy sometimes you do Nuka missionary + + + align:start position:0% +Oh easy sometimes you do Nuka missionary +what corner + + align:start position:0% +what corner + + + align:start position:0% +what corner +two blocks to the other side because + + align:start position:0% + + + + align:start position:0% + +for from the perspective the oil gas or + + align:start position:0% +for from the perspective the oil gas or + + + align:start position:0% +for from the perspective the oil gas or +you teach hammers only the first + + align:start position:0% +you teach hammers only the first + + + align:start position:0% +you teach hammers only the first +priority is for next run + + align:start position:0% +priority is for next run + + + align:start position:0% +priority is for next run +yeah of course I can't say + + align:start position:0% + + + + align:start position:0% + +save 5% a pig liver that's okay this is + + align:start position:0% +save 5% a pig liver that's okay this is + + + align:start position:0% +save 5% a pig liver that's okay this is +maybe + + align:start position:0% + + + + align:start position:0% + +effort to do this + + align:start position:0% +effort to do this + + + align:start position:0% +effort to do this +where the path to the end is Goshen + + align:start position:0% +where the path to the end is Goshen + + + align:start position:0% +where the path to the end is Goshen +Christmas + + align:start position:0% +Christmas + + + align:start position:0% +Christmas +and when what the general manager of + + align:start position:0% +and when what the general manager of + + + align:start position:0% +and when what the general manager of +many of the assets know that he has a + + align:start position:0% +many of the assets know that he has a + + + align:start position:0% +many of the assets know that he has a +suit area + + align:start position:0% + + + + align:start position:0% + +if you put this information + + align:start position:0% +if you put this information + + + align:start position:0% +if you put this information +address they went with you + + align:start position:0% + + + + align:start position:0% + +it's not to cut it because they know + + align:start position:0% +it's not to cut it because they know + + + align:start position:0% +it's not to cut it because they know +yeah it's nothing nothing they + + align:start position:0% + + + + align:start position:0% + +yeah maybe synopsis I work for the oil + + align:start position:0% +yeah maybe synopsis I work for the oil + + + align:start position:0% +yeah maybe synopsis I work for the oil +company but I know when you have risk + + align:start position:0% +company but I know when you have risk + + + align:start position:0% +company but I know when you have risk +right the decoration yeah you need to + + align:start position:0% +right the decoration yeah you need to + + + align:start position:0% +right the decoration yeah you need to +take this + + align:start position:0% +take this + + + align:start position:0% +take this +no they are not good + + align:start position:0% + + + + align:start position:0% + +I would agree with that you know there's + + align:start position:0% +I would agree with that you know there's + + + align:start position:0% +I would agree with that you know there's +a nexus of issues associated with the + + align:start position:0% +a nexus of issues associated with the + + + align:start position:0% +a nexus of issues associated with the +gas leaks at the local scale + + align:start position:0% +gas leaks at the local scale + + + align:start position:0% +gas leaks at the local scale +explosion risks risks to vegetation and + + align:start position:0% +explosion risks risks to vegetation and + + + align:start position:0% +explosion risks risks to vegetation and +trees that's local air quality + + align:start position:0% +trees that's local air quality + + + align:start position:0% +trees that's local air quality +degradation is more of a regional thing + + align:start position:0% +degradation is more of a regional thing + + + align:start position:0% +degradation is more of a regional thing +and then there's a group that the global + + align:start position:0% +and then there's a group that the global + + + align:start position:0% +and then there's a group that the global +issue and they're all issues and they + + align:start position:0% +issue and they're all issues and they + + + align:start position:0% +issue and they're all issues and they +should all be considered because after + + align:start position:0% +should all be considered because after + + + align:start position:0% +should all be considered because after +our Boston study I remember that I was + + align:start position:0% +our Boston study I remember that I was + + + align:start position:0% +our Boston study I remember that I was +on Greater Boston the TV show and the + + align:start position:0% +on Greater Boston the TV show and the + + + align:start position:0% +on Greater Boston the TV show and the +PERT of co-panelists was the Secretary + + align:start position:0% +PERT of co-panelists was the Secretary + + + align:start position:0% +PERT of co-panelists was the Secretary +of Energy and Environment for + + align:start position:0% +of Energy and Environment for + + + align:start position:0% +of Energy and Environment for +Massachusetts and he said he said thank + + align:start position:0% +Massachusetts and he said he said thank + + + align:start position:0% +Massachusetts and he said he said thank +you for the work you're doing because + + align:start position:0% +you for the work you're doing because + + + align:start position:0% +you for the work you're doing because +you're giving me a way to make this + + align:start position:0% +you're giving me a way to make this + + + align:start position:0% +you're giving me a way to make this +issue you know the explosion issue + + align:start position:0% +issue you know the explosion issue + + + align:start position:0% +issue you know the explosion issue +allowed him to push forward the climate + + align:start position:0% +allowed him to push forward the climate + + + align:start position:0% +allowed him to push forward the climate +change part of this so yeah it's + + align:start position:0% +change part of this so yeah it's + + + align:start position:0% +change part of this so yeah it's +consistent before + + align:start position:0% +consistent before + + + align:start position:0% +consistent before +when we do that version for the first + + align:start position:0% +when we do that version for the first + + + align:start position:0% +when we do that version for the first +time working on gas leak + + align:start position:0% + + + + align:start position:0% + +he ever been talked to by somebody + + align:start position:0% +he ever been talked to by somebody + + + align:start position:0% +he ever been talked to by somebody +walking along all the time why is the + + align:start position:0% +walking along all the time why is the + + + align:start position:0% +walking along all the time why is the +situation gotten to be like this + + align:start position:0% + + + + align:start position:0% + +well he's been Bob Ackley has been a + + align:start position:0% +well he's been Bob Ackley has been a + + + align:start position:0% +well he's been Bob Ackley has been a +lone voice for the last 30 years that + + align:start position:0% +lone voice for the last 30 years that + + + align:start position:0% +lone voice for the last 30 years that +who has been struggling to be not just + + align:start position:0% +who has been struggling to be not just + + + align:start position:0% +who has been struggling to be not just +the only person who has been calling + + align:start position:0% +the only person who has been calling + + + align:start position:0% +the only person who has been calling +this issue out and I think he feels I + + align:start position:0% +this issue out and I think he feels I + + + align:start position:0% +this issue out and I think he feels I +don't want to speak for him but but that + + align:start position:0% +don't want to speak for him but but that + + + align:start position:0% +don't want to speak for him but but that +when people started to join with him + + align:start position:0% +when people started to join with him + + + align:start position:0% +when people started to join with him +that's when I think he started to feel + + align:start position:0% +that's when I think he started to feel + + + align:start position:0% +that's when I think he started to feel +some level of vindication that it's not + + align:start position:0% +some level of vindication that it's not + + + align:start position:0% +some level of vindication that it's not +just it's not just me you know but that + + align:start position:0% +just it's not just me you know but that + + + align:start position:0% +just it's not just me you know but that +and so as this network has grown larger + + align:start position:0% +and so as this network has grown larger + + + align:start position:0% +and so as this network has grown larger +I think the changes are are the policy + + align:start position:0% +I think the changes are are the policy + + + align:start position:0% +I think the changes are are the policy +changes are happening because it's just + + align:start position:0% +changes are happening because it's just + + + align:start position:0% +changes are happening because it's just +everyone's seen that this is a problem + + align:start position:0% +everyone's seen that this is a problem + + + align:start position:0% +everyone's seen that this is a problem +but yeah he's been struggling on his own + + align:start position:0% +but yeah he's been struggling on his own + + + align:start position:0% +but yeah he's been struggling on his own +hurt I mean he worked for the gas + + align:start position:0% +hurt I mean he worked for the gas + + + align:start position:0% +hurt I mean he worked for the gas +companies to do leak surveys so for the + + align:start position:0% +companies to do leak surveys so for the + + + align:start position:0% +companies to do leak surveys so for the +most of much of his career he was + + align:start position:0% +most of much of his career he was + + + align:start position:0% +most of much of his career he was +basically a worker for the gas than I + + align:start position:0% +basically a worker for the gas than I + + + align:start position:0% +basically a worker for the gas than I +here's you know here's the leak report + + align:start position:0% +here's you know here's the leak report + + + align:start position:0% +here's you know here's the leak report +Tara that gas leaks and he would notice + + align:start position:0% +Tara that gas leaks and he would notice + + + align:start position:0% +Tara that gas leaks and he would notice +trees were dying and that the gas + + align:start position:0% +trees were dying and that the gas + + + align:start position:0% +trees were dying and that the gas +companies were not taking that seriously + + align:start position:0% +companies were not taking that seriously + + + align:start position:0% +companies were not taking that seriously +they're like well we're not gonna worry + + align:start position:0% +they're like well we're not gonna worry + + + align:start position:0% +they're like well we're not gonna worry +about that and that really bothered him + + align:start position:0% +about that and that really bothered him + + + align:start position:0% +about that and that really bothered him +so at some point he defected and went + + align:start position:0% +so at some point he defected and went + + + align:start position:0% +so at some point he defected and went +out on his own because the treaties were + + align:start position:0% +out on his own because the treaties were + + + align:start position:0% +out on his own because the treaties were +he felt like his work wasn't being taken + + align:start position:0% +he felt like his work wasn't being taken + + + align:start position:0% +he felt like his work wasn't being taken +seriously and so he struck out on his + + align:start position:0% +seriously and so he struck out on his + + + align:start position:0% +seriously and so he struck out on his +own but it you know it's one person and + + align:start position:0% +own but it you know it's one person and + + + align:start position:0% +own but it you know it's one person and +these massive investor owned utilities + + align:start position:0% +these massive investor owned utilities + + + align:start position:0% +these massive investor owned utilities +you know that has made it very difficult + + align:start position:0% + + + + align:start position:0% + +I saw your latest now between them yeah + + align:start position:0% +I saw your latest now between them yeah + + + align:start position:0% +I saw your latest now between them yeah +that is that the new line yes yes that's + + align:start position:0% +that is that the new line yes yes that's + + + align:start position:0% +that is that the new line yes yes that's +the West rocks are a lateral pipeline + + align:start position:0% +the West rocks are a lateral pipeline + + + align:start position:0% +the West rocks are a lateral pipeline +actually makes yeah I so I'm gonna just + + align:start position:0% +actually makes yeah I so I'm gonna just + + + align:start position:0% +actually makes yeah I so I'm gonna just +show it so we went out on Monday while + + align:start position:0% +show it so we went out on Monday while + + + align:start position:0% +show it so we went out on Monday while +back we and myself and my son and so you + + align:start position:0% +back we and myself and my son and so you + + + align:start position:0% +back we and myself and my son and so you +see this spike something something like + + align:start position:0% +see this spike something something like + + + align:start position:0% +see this spike something something like +this right using the red spikes and this + + align:start position:0% +this right using the red spikes and this + + + align:start position:0% +this right using the red spikes and this +is on a stretch of this East Street in + + align:start position:0% +is on a stretch of this East Street in + + + align:start position:0% +is on a stretch of this East Street in +Dedham very close to Denham center right + + align:start position:0% +Dedham very close to Denham center right + + + align:start position:0% +Dedham very close to Denham center right +by where the Boston of Providence turn + + align:start position:0% +by where the Boston of Providence turn + + + align:start position:0% +by where the Boston of Providence turn +turns like that or whatever it's called + + align:start position:0% +turns like that or whatever it's called + + + align:start position:0% +turns like that or whatever it's called +you know the fast moving thing that + + align:start position:0% +you know the fast moving thing that + + + align:start position:0% +you know the fast moving thing that +stretch of East Street which is about an + + align:start position:0% +stretch of East Street which is about an + + + align:start position:0% +stretch of East Street which is about an +eighth of a model is part of the pathway + + align:start position:0% +eighth of a model is part of the pathway + + + align:start position:0% +eighth of a model is part of the pathway +of the new West Roxbury lateral pipeline + + align:start position:0% +of the new West Roxbury lateral pipeline + + + align:start position:0% +of the new West Roxbury lateral pipeline +which is a 750 pounds per square inch 2 + + align:start position:0% +which is a 750 pounds per square inch 2 + + + align:start position:0% +which is a 750 pounds per square inch 2 +foot diameter transmission pipeline spur + + align:start position:0% +foot diameter transmission pipeline spur + + + align:start position:0% +foot diameter transmission pipeline spur +that has been parked in spectra energy + + align:start position:0% +that has been parked in spectra energy + + + align:start position:0% +that has been parked in spectra energy +it's their project to increase the gas + + align:start position:0% +it's their project to increase the gas + + + align:start position:0% +it's their project to increase the gas +flow in Boston and what's really + + align:start position:0% +flow in Boston and what's really + + + align:start position:0% +flow in Boston and what's really +disturbing about what we found on Monday + + align:start position:0% +disturbing about what we found on Monday + + + align:start position:0% +disturbing about what we found on Monday +is that this is where in the last year + + align:start position:0% +is that this is where in the last year + + + align:start position:0% +is that this is where in the last year +they've trenched that entire roadway and + + align:start position:0% +they've trenched that entire roadway and + + + align:start position:0% +they've trenched that entire roadway and +click this new pipe and then they + + align:start position:0% +click this new pipe and then they + + + align:start position:0% +click this new pipe and then they +covered it up paved new paving new + + align:start position:0% +covered it up paved new paving new + + + align:start position:0% +covered it up paved new paving new +sidewalks but they left leaking + + align:start position:0% +sidewalks but they left leaking + + + align:start position:0% +sidewalks but they left leaking +pipelines that the low pressure + + align:start position:0% +pipelines that the low pressure + + + align:start position:0% +pipelines that the low pressure +distribution pipelines they've left them + + align:start position:0% +distribution pipelines they've left them + + + align:start position:0% +distribution pipelines they've left them +leaking and that's where there's all of + + align:start position:0% +leaking and that's where there's all of + + + align:start position:0% +leaking and that's where there's all of +these leaks one after the other and so + + align:start position:0% +these leaks one after the other and so + + + align:start position:0% +these leaks one after the other and so +it was a missed opportunity if you're + + align:start position:0% +it was a missed opportunity if you're + + + align:start position:0% +it was a missed opportunity if you're +going to dig up the street don't leave + + align:start position:0% +going to dig up the street don't leave + + + align:start position:0% +going to dig up the street don't leave +hundred-year-old pipe leaking pipelines + + align:start position:0% +hundred-year-old pipe leaking pipelines + + + align:start position:0% +hundred-year-old pipe leaking pipelines +there fix it + + align:start position:0% +there fix it + + + align:start position:0% +there fix it +if there's already practicing + + align:start position:0% +if there's already practicing + + + align:start position:0% +if there's already practicing +in this new pavement which are going to + + align:start position:0% +in this new pavement which are going to + + + align:start position:0% +in this new pavement which are going to +mean couples are going to thought-form + + align:start position:0% +mean couples are going to thought-form + + + align:start position:0% +mean couples are going to thought-form +soon these leaves the spokes divided by + + align:start position:0% +soon these leaves the spokes divided by + + + align:start position:0% +soon these leaves the spokes divided by +the width you know they're they're the + + align:start position:0% +the width you know they're they're the + + + align:start position:0% +the width you know they're they're the +old distribution low pressure pipelines + + align:start position:0% +old distribution low pressure pipelines + + + align:start position:0% +old distribution low pressure pipelines +that should have been fixed at the same + + align:start position:0% +that should have been fixed at the same + + + align:start position:0% +that should have been fixed at the same +time that they put them in my plan + + align:start position:0% + + + + align:start position:0% + +great so two questions one what's the + + align:start position:0% +great so two questions one what's the + + + align:start position:0% +great so two questions one what's the +name of your instrument + + align:start position:0% +name of your instrument + + + align:start position:0% +name of your instrument +more valley and then how those EPA rule + + align:start position:0% +more valley and then how those EPA rule + + + align:start position:0% +more valley and then how those EPA rule +or any okay yes you get to go on the + + align:start position:0% +or any okay yes you get to go on the + + + align:start position:0% +or any okay yes you get to go on the +31st okay well we can arrange something + + align:start position:0% +31st okay well we can arrange something + + + align:start position:0% +31st okay well we can arrange something +on another occasion I'm not sure but can + + align:start position:0% +on another occasion I'm not sure but can + + + align:start position:0% +on another occasion I'm not sure but can +get in the van you can see that the + + align:start position:0% +get in the van you can see that the + + + align:start position:0% +get in the van you can see that the +picture that Audrey showed that it's + + align:start position:0% +picture that Audrey showed that it's + + + align:start position:0% +picture that Audrey showed that it's +it's um it's called a cavity breakdown + + align:start position:0% +it's um it's called a cavity breakdown + + + align:start position:0% +it's um it's called a cavity breakdown +spectrometer that's the technology it's + + align:start position:0% +spectrometer that's the technology it's + + + align:start position:0% +spectrometer that's the technology it's +a laser technology it has a little + + align:start position:0% +a laser technology it has a little + + + align:start position:0% +a laser technology it has a little +chamber in it that is evacuated down to + + align:start position:0% +chamber in it that is evacuated down to + + + align:start position:0% +chamber in it that is evacuated down to +about one-fifth of a full vacuum so it's + + align:start position:0% +about one-fifth of a full vacuum so it's + + + align:start position:0% +about one-fifth of a full vacuum so it's +got about twenty percent of the air + + align:start position:0% +got about twenty percent of the air + + + align:start position:0% +got about twenty percent of the air +molecules that you know normally + + align:start position:0% +molecules that you know normally + + + align:start position:0% +molecules that you know normally +everybody have in it so it's pulled down + + align:start position:0% +everybody have in it so it's pulled down + + + align:start position:0% +everybody have in it so it's pulled down +to that level it's about like a one + + align:start position:0% +to that level it's about like a one + + + align:start position:0% +to that level it's about like a one +liter chamber and in that chamber there + + align:start position:0% +liter chamber and in that chamber there + + + align:start position:0% +liter chamber and in that chamber there +are three mirrors that are pointed at + + align:start position:0% +are three mirrors that are pointed at + + + align:start position:0% +are three mirrors that are pointed at +each other and then they pulse a laser + + align:start position:0% +each other and then they pulse a laser + + + align:start position:0% +each other and then they pulse a laser +into that that is tuned to the + + align:start position:0% +into that that is tuned to the + + + align:start position:0% +into that that is tuned to the +absorbance a unique absorbance band for + + align:start position:0% +absorbance a unique absorbance band for + + + align:start position:0% +absorbance a unique absorbance band for +methane and it that pulse of laser + + align:start position:0% +methane and it that pulse of laser + + + align:start position:0% +methane and it that pulse of laser +bounces around the three mirrors + + align:start position:0% +bounces around the three mirrors + + + align:start position:0% +bounces around the three mirrors +that's called reading down it's ringing + + align:start position:0% +that's called reading down it's ringing + + + align:start position:0% +that's called reading down it's ringing +in that thing and bouncing around and + + align:start position:0% +in that thing and bouncing around and + + + align:start position:0% +in that thing and bouncing around and +the more concentration of methane there + + align:start position:0% +the more concentration of methane there + + + align:start position:0% +the more concentration of methane there +is in that air the faster that pulse + + align:start position:0% +is in that air the faster that pulse + + + align:start position:0% +is in that air the faster that pulse +will decay to zero because the molecules + + align:start position:0% +will decay to zero because the molecules + + + align:start position:0% +will decay to zero because the molecules +of methane are absorbing so there's no + + align:start position:0% +of methane are absorbing so there's no + + + align:start position:0% +of methane are absorbing so there's no +metadata variable it will take a long + + align:start position:0% +metadata variable it will take a long + + + align:start position:0% +metadata variable it will take a long +time for that thing to decay that light + + align:start position:0% +time for that thing to decay that light + + + align:start position:0% +time for that thing to decay that light +poles and so that's the that's the basic + + align:start position:0% +poles and so that's the that's the basic + + + align:start position:0% +poles and so that's the that's the basic +method for the cavity ring though + + align:start position:0% +method for the cavity ring though + + + align:start position:0% +method for the cavity ring though +if you feel better the manufacturer is + + align:start position:0% +if you feel better the manufacturer is + + + align:start position:0% +if you feel better the manufacturer is +for the mist relieved is called Picaro + + align:start position:0% +for the mist relieved is called Picaro + + + align:start position:0% +for the mist relieved is called Picaro +and they're based in santa clara the the + + align:start position:0% +and they're based in santa clara the the + + + align:start position:0% +and they're based in santa clara the the +technology and the patents were mostly + + align:start position:0% +technology and the patents were mostly + + + align:start position:0% +technology and the patents were mostly +from Stanford University scientists + + align:start position:0% +from Stanford University scientists + + + align:start position:0% +from Stanford University scientists +there's another firm that's doing it the + + align:start position:0% +there's another firm that's doing it the + + + align:start position:0% +there's another firm that's doing it the +same basic kind of technology called los + + align:start position:0% +same basic kind of technology called los + + + align:start position:0% +same basic kind of technology called los +gatos out in in in that area of + + align:start position:0% +gatos out in in in that area of + + + align:start position:0% +gatos out in in in that area of +California as well you know there's a + + align:start position:0% +California as well you know there's a + + + align:start position:0% +California as well you know there's a +few different flavors of this kind of + + align:start position:0% +few different flavors of this kind of + + + align:start position:0% +few different flavors of this kind of +measurement so do you think that there's + + align:start position:0% +measurement so do you think that there's + + + align:start position:0% +measurement so do you think that there's +because this is an expensive instrument + + align:start position:0% +because this is an expensive instrument + + + align:start position:0% +because this is an expensive instrument +right parts of the console this one was + + align:start position:0% +right parts of the console this one was + + + align:start position:0% +right parts of the console this one was +about 60 K I'm thinking more in the + + align:start position:0% +about 60 K I'm thinking more in the + + + align:start position:0% +about 60 K I'm thinking more in the +community science direction we I think + + align:start position:0% +community science direction we I think + + + align:start position:0% +community science direction we I think +cheap lasers are becoming available + + align:start position:0% +cheap lasers are becoming available + + + align:start position:0% +cheap lasers are becoming available +right and right while it may be the mara + + align:start position:0% +right and right while it may be the mara + + + align:start position:0% +right and right while it may be the mara +configuration might be expensive piece + + align:start position:0% +configuration might be expensive piece + + + align:start position:0% +configuration might be expensive piece +there is there a way to combine maybe + + align:start position:0% +there is there a way to combine maybe + + + align:start position:0% +there is there a way to combine maybe +pulse lasers and using data analytic + + align:start position:0% +pulse lasers and using data analytic + + + align:start position:0% +pulse lasers and using data analytic +techniques to do + + align:start position:0% +techniques to do + + + align:start position:0% +techniques to do +well you want it I'm doing all the time + + align:start position:0% +well you want it I'm doing all the time + + + align:start position:0% +well you want it I'm doing all the time +I'm gonna see ya I'm gonna come back to + + align:start position:0% +I'm gonna see ya I'm gonna come back to + + + align:start position:0% +I'm gonna see ya I'm gonna come back to +somewhere like MIT to the people here + + align:start position:0% +somewhere like MIT to the people here + + + align:start position:0% +somewhere like MIT to the people here +it's like the robot thing yeah you have + + align:start position:0% +it's like the robot thing yeah you have + + + align:start position:0% +it's like the robot thing yeah you have +swarms a little tiny robots fixing + + align:start position:0% +swarms a little tiny robots fixing + + + align:start position:0% +swarms a little tiny robots fixing +pipelines and MIT is a great community + + align:start position:0% +pipelines and MIT is a great community + + + align:start position:0% +pipelines and MIT is a great community +to come up with those types of solutions + + align:start position:0% +to come up with those types of solutions + + + align:start position:0% +to come up with those types of solutions +and then as well low cost sensors that + + align:start position:0% +and then as well low cost sensors that + + + align:start position:0% +and then as well low cost sensors that +could could do this would be would + + align:start position:0% +could could do this would be would + + + align:start position:0% +could could do this would be would +unlock opportunities for a much wider + + align:start position:0% +unlock opportunities for a much wider + + + align:start position:0% +unlock opportunities for a much wider +group of people to be doing this stuff + + align:start position:0% +group of people to be doing this stuff + + + align:start position:0% +group of people to be doing this stuff +and and I don't think they all have to + + align:start position:0% +and and I don't think they all have to + + + align:start position:0% +and and I don't think they all have to +be expensive like there's just one + + align:start position:0% +be expensive like there's just one + + + align:start position:0% +be expensive like there's just one +technology where it's just something + + align:start position:0% +technology where it's just something + + + align:start position:0% +technology where it's just something +that goes on the pipe seal you know + + align:start position:0% +that goes on the pipe seal you know + + + align:start position:0% +that goes on the pipe seal you know +between the two joints because that's + + align:start position:0% +between the two joints because that's + + + align:start position:0% +between the two joints because that's +where most of the leaks come from and if + + align:start position:0% +where most of the leaks come from and if + + + align:start position:0% +where most of the leaks come from and if +that is that link is broken it tells the + + align:start position:0% +that is that link is broken it tells the + + + align:start position:0% +that is that link is broken it tells the +office like that's a simple you know + + align:start position:0% +office like that's a simple you know + + + align:start position:0% +office like that's a simple you know +let's do something simple like that + + align:start position:0% +let's do something simple like that + + + align:start position:0% +let's do something simple like that +that's not expensive that's not hard + + align:start position:0% + + + + align:start position:0% + +check the the leaks operations we use a + + align:start position:0% +check the the leaks operations we use a + + + align:start position:0% +check the the leaks operations we use a +night correct camera yeah you can see + + align:start position:0% +night correct camera yeah you can see + + + align:start position:0% +night correct camera yeah you can see +those + + align:start position:0% + + + + align:start position:0% + +Misha + + align:start position:0% +Misha + + + align:start position:0% +Misha +right destiny + + align:start position:0% + + + + align:start position:0% + +yeah and in poor quality yeah but you + + align:start position:0% +yeah and in poor quality yeah but you + + + align:start position:0% +yeah and in poor quality yeah but you +can see you could they put two videos + + align:start position:0% +can see you could they put two videos + + + align:start position:0% +can see you could they put two videos +yeah + + align:start position:0% + + + + align:start position:0% + +that you saw sorry very quickly + + align:start position:0% +that you saw sorry very quickly + + + align:start position:0% +that you saw sorry very quickly +mentioned that the political part is the + + align:start position:0% +mentioned that the political part is the + + + align:start position:0% +mentioned that the political part is the +town of Brookline has now passed two + + align:start position:0% +town of Brookline has now passed two + + + align:start position:0% +town of Brookline has now passed two +resolutions opposing natural gas + + align:start position:0% +resolutions opposing natural gas + + + align:start position:0% +resolutions opposing natural gas +pipeline expansion in Massachusetts were + + align:start position:0% +pipeline expansion in Massachusetts were + + + align:start position:0% +pipeline expansion in Massachusetts were +the first community to do such a thing + + align:start position:0% +the first community to do such a thing + + + align:start position:0% +the first community to do such a thing +that where the pipeline was not + + align:start position:0% +that where the pipeline was not + + + align:start position:0% +that where the pipeline was not +scheduled to go through you know in our + + align:start position:0% +scheduled to go through you know in our + + + align:start position:0% +scheduled to go through you know in our +boundaries so and we'd be happy to + + align:start position:0% +boundaries so and we'd be happy to + + + align:start position:0% +boundaries so and we'd be happy to +Brooklyn town meeting to look into the + + align:start position:0% +Brooklyn town meeting to look into the + + + align:start position:0% +Brooklyn town meeting to look into the +issue of somehow pressuring the gas + + align:start position:0% +issue of somehow pressuring the gas + + + align:start position:0% +issue of somehow pressuring the gas +companies to you know more speedily + + align:start position:0% +companies to you know more speedily + + + align:start position:0% +companies to you know more speedily +addressing issues + + align:start position:0% +addressing issues + + + align:start position:0% +addressing issues +in our town kind of a general pressure + + align:start position:0% +in our town kind of a general pressure + + + align:start position:0% +in our town kind of a general pressure +issue + + align:start position:0% + + + + align:start position:0% + +yeah and and we want that the more + + align:start position:0% +yeah and and we want that the more + + + align:start position:0% +yeah and and we want that the more +pressure they have the more everybody + + align:start position:0% +pressure they have the more everybody + + + align:start position:0% +pressure they have the more everybody +takes it seriously as it should be so we + + align:start position:0% +takes it seriously as it should be so we + + + align:start position:0% +takes it seriously as it should be so we +have three more sessions on the 23rd + + align:start position:0% +have three more sessions on the 23rd + + + align:start position:0% +have three more sessions on the 23rd +which is the coming Monday we have a + + align:start position:0% +which is the coming Monday we have a + + + align:start position:0% +which is the coming Monday we have a +hackathon and again you will be playing + + align:start position:0% +hackathon and again you will be playing + + + align:start position:0% +hackathon and again you will be playing +with how the two different ways of + + align:start position:0% +with how the two different ways of + + + align:start position:0% +with how the two different ways of +hacking with the Zeta one is more data + + align:start position:0% +hacking with the Zeta one is more data + + + align:start position:0% +hacking with the Zeta one is more data +centric more code centric the other + + align:start position:0% +centric more code centric the other + + + align:start position:0% +centric more code centric the other +might be more designer etc so dependable + + align:start position:0% +might be more designer etc so dependable + + + align:start position:0% +might be more designer etc so dependable +logic so visualizing the data again + + align:start position:0% +logic so visualizing the data again + + + align:start position:0% +logic so visualizing the data again +depending on what your interests are you + + align:start position:0% +depending on what your interests are you + + + align:start position:0% +depending on what your interests are you +can do one or the other do sign up onto + + align:start position:0% +can do one or the other do sign up onto + + + align:start position:0% +can do one or the other do sign up onto +the clay insight if you haven't already + + align:start position:0% +the clay insight if you haven't already + + + align:start position:0% +the clay insight if you haven't already +done so the other two the next session + + align:start position:0% +done so the other two the next session + + + align:start position:0% +done so the other two the next session +on the 31st is driving around town and + + align:start position:0% +on the 31st is driving around town and + + + align:start position:0% +on the 31st is driving around town and +spelling that's going to be how are you + + align:start position:0% +spelling that's going to be how are you + + + align:start position:0% +spelling that's going to be how are you +doing and finally on the first you will + + align:start position:0% +doing and finally on the first you will + + + align:start position:0% +doing and finally on the first you will +come back together and say what can no + + align:start position:0% +come back together and say what can no + + + align:start position:0% +come back together and say what can no +communities and citizens working and + + align:start position:0% +communities and citizens working and + + + align:start position:0% +communities and citizens working and +scientists do with this can you take + + align:start position:0% +scientists do with this can you take + + + align:start position:0% +scientists do with this can you take +this to court + + align:start position:0% +this to court + + + align:start position:0% +this to court +what so how do you build an ecosystem + + align:start position:0% +what so how do you build an ecosystem + + + align:start position:0% +what so how do you build an ecosystem +that addresses these + + align:start position:0% +that addresses these + + + align:start position:0% +that addresses these +do not just do it individual + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/mVZ8Sx2wPMI.txt b/mVZ8Sx2wPMI.txt new file mode 100644 index 0000000000000000000000000000000000000000..0306ad03945754a22bf9b35bad8ed64e1711af9e --- /dev/null +++ b/mVZ8Sx2wPMI.txt @@ -0,0 +1,1147 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +the fields of a circular cylindrical + + align:start position:0% +the fields of a circular cylindrical + + + align:start position:0% +the fields of a circular cylindrical +solenoid can be found using the B SAR + + align:start position:0% + + + + align:start position:0% + +law if these plain parallel plates were + + align:start position:0% +law if these plain parallel plates were + + + align:start position:0% +law if these plain parallel plates were +of infinite extent an applied volage + + align:start position:0% +of infinite extent an applied volage + + + align:start position:0% +of infinite extent an applied volage +would give an electric field that is + + align:start position:0% +would give an electric field that is + + + align:start position:0% +would give an electric field that is +uniform what this plain parallel + + align:start position:0% +uniform what this plain parallel + + + align:start position:0% +uniform what this plain parallel +capacitor is to Electric Fields an + + align:start position:0% +capacitor is to Electric Fields an + + + align:start position:0% +capacitor is to Electric Fields an +infinitely long solenoid is to magnetic + + align:start position:0% +infinitely long solenoid is to magnetic + + + align:start position:0% +infinitely long solenoid is to magnetic +fields that is if this solenoid were + + align:start position:0% +fields that is if this solenoid were + + + align:start position:0% +fields that is if this solenoid were +infinitely long + + align:start position:0% +infinitely long + + + align:start position:0% +infinitely long +a current in the winding would produce a + + align:start position:0% +a current in the winding would produce a + + + align:start position:0% +a current in the winding would produce a +magnetic field intensity that is + + align:start position:0% +magnetic field intensity that is + + + align:start position:0% +magnetic field intensity that is +essentially uniform inside and equal to + + align:start position:0% +essentially uniform inside and equal to + + + align:start position:0% +essentially uniform inside and equal to +the surface current density outside the + + align:start position:0% +the surface current density outside the + + + align:start position:0% +the surface current density outside the +field would be essentially + + align:start position:0% + + + + align:start position:0% + +zero this solenoid is large enough that + + align:start position:0% +zero this solenoid is large enough that + + + align:start position:0% +zero this solenoid is large enough that +we can poke around in it with a + + align:start position:0% +we can poke around in it with a + + + align:start position:0% +we can poke around in it with a +magnetometer + + align:start position:0% + + + + align:start position:0% + +probe and see how the magnetic field is + + align:start position:0% +probe and see how the magnetic field is + + + align:start position:0% +probe and see how the magnetic field is +actually distributed when the length is + + align:start position:0% +actually distributed when the length is + + + align:start position:0% +actually distributed when the length is +finite + + align:start position:0% + + + + align:start position:0% + +the solenoidal coil consists of n turns + + align:start position:0% +the solenoidal coil consists of n turns + + + align:start position:0% +the solenoidal coil consists of n turns +essentially uniformly wound over the + + align:start position:0% +essentially uniformly wound over the + + + align:start position:0% +essentially uniformly wound over the +length D each turn carrying the same + + align:start position:0% +length D each turn carrying the same + + + align:start position:0% +length D each turn carrying the same +current I the radius is a the current I + + align:start position:0% +current I the radius is a the current I + + + align:start position:0% +current I the radius is a the current I +is essentially F + + align:start position:0% + + + + align:start position:0% + +directed this axial hole probe shows us + + align:start position:0% +directed this axial hole probe shows us + + + align:start position:0% +directed this axial hole probe shows us +the magnitude and direction of the field + + align:start position:0% +the magnitude and direction of the field + + + align:start position:0% +the magnitude and direction of the field +the probe measures the field along its + + align:start position:0% +the probe measures the field along its + + + align:start position:0% +the probe measures the field along its +axis the lower scope Trace records the + + align:start position:0% +axis the lower scope Trace records the + + + align:start position:0% +axis the lower scope Trace records the +probe output the the upper scope Trace + + align:start position:0% +probe output the the upper scope Trace + + + align:start position:0% +probe output the the upper scope Trace +shows the coil + + align:start position:0% +shows the coil + + + align:start position:0% +shows the coil +current when the probe is oriented this + + align:start position:0% +current when the probe is oriented this + + + align:start position:0% +current when the probe is oriented this +way the axial component of magnetic + + align:start position:0% +way the axial component of magnetic + + + align:start position:0% +way the axial component of magnetic +field is measured when the probe is + + align:start position:0% +field is measured when the probe is + + + align:start position:0% +field is measured when the probe is +oriented this way the radial component + + align:start position:0% +oriented this way the radial component + + + align:start position:0% +oriented this way the radial component +of magnetic field is measured let's + + align:start position:0% +of magnetic field is measured let's + + + align:start position:0% +of magnetic field is measured let's +measure the axial magnetic field + + align:start position:0% +measure the axial magnetic field + + + align:start position:0% +measure the axial magnetic field +component along the axis of the + + align:start position:0% + + + + align:start position:0% + +cylinder on the axis the radial + + align:start position:0% +cylinder on the axis the radial + + + align:start position:0% +cylinder on the axis the radial +component is of course zero because of + + align:start position:0% + + + + align:start position:0% + +symmetry well inside the solenoid the + + align:start position:0% +symmetry well inside the solenoid the + + + align:start position:0% +symmetry well inside the solenoid the +field intensity in the Z Direction tends + + align:start position:0% +field intensity in the Z Direction tends + + + align:start position:0% +field intensity in the Z Direction tends +to be uniform + + align:start position:0% + + + + align:start position:0% + +everywhere the infinitely long solenoid + + align:start position:0% +everywhere the infinitely long solenoid + + + align:start position:0% +everywhere the infinitely long solenoid +can be regarded as the analog for mqs + + align:start position:0% +can be regarded as the analog for mqs + + + align:start position:0% +can be regarded as the analog for mqs +systems of the eqs plain parallel plate + + align:start position:0% + + + + align:start position:0% + +capacitor what well away from the ends + + align:start position:0% +capacitor what well away from the ends + + + align:start position:0% +capacitor what well away from the ends +the axial field just inside the coil + + align:start position:0% +the axial field just inside the coil + + + align:start position:0% +the axial field just inside the coil +should be equal to the surface current + + align:start position:0% +should be equal to the surface current + + + align:start position:0% +should be equal to the surface current +density the surface current density is + + align:start position:0% +density the surface current density is + + + align:start position:0% +density the surface current density is +the number of turns times the current + + align:start position:0% +the number of turns times the current + + + align:start position:0% +the number of turns times the current +per turn divided by the length + + align:start position:0% + + + + align:start position:0% + +D the probe measures the flux density mu + + align:start position:0% +D the probe measures the flux density mu + + + align:start position:0% +D the probe measures the flux density mu +note H to convert from SI units Tesla to + + align:start position:0% +note H to convert from SI units Tesla to + + + align:start position:0% +note H to convert from SI units Tesla to +gaus we multiply by + + align:start position:0% +gaus we multiply by + + + align:start position:0% +gaus we multiply by +10,000 there are 141 turns + + align:start position:0% +10,000 there are 141 turns + + + align:start position:0% +10,000 there are 141 turns +our current is 1 amp + + align:start position:0% +our current is 1 amp + + + align:start position:0% +our current is 1 amp +RMS and the coil length is 70.5 + + align:start position:0% +RMS and the coil length is 70.5 + + + align:start position:0% +RMS and the coil length is 70.5 +CM the predicted flux density just + + align:start position:0% +CM the predicted flux density just + + + align:start position:0% +CM the predicted flux density just +inside the coil is 2 and2 G + + align:start position:0% +inside the coil is 2 and2 G + + + align:start position:0% +inside the coil is 2 and2 G +RMS this is on the order of the steady + + align:start position:0% +RMS this is on the order of the steady + + + align:start position:0% +RMS this is on the order of the steady +flux density produced by currents inside + + align:start position:0% +flux density produced by currents inside + + + align:start position:0% +flux density produced by currents inside +the earth so that we can distinguish our + + align:start position:0% +the earth so that we can distinguish our + + + align:start position:0% +the earth so that we can distinguish our +fields we are using a 60 HZ + + align:start position:0% + + + + align:start position:0% + +current let's measure the magnetic field + + align:start position:0% +current let's measure the magnetic field + + + align:start position:0% +current let's measure the magnetic field +well inside the solenoid + + align:start position:0% + + + + align:start position:0% + +we measure about 2.3 G just inside the + + align:start position:0% +we measure about 2.3 G just inside the + + + align:start position:0% +we measure about 2.3 G just inside the +winding as compared to the prediction of + + align:start position:0% +winding as compared to the prediction of + + + align:start position:0% +winding as compared to the prediction of +2 and A2 + + align:start position:0% +2 and A2 + + + align:start position:0% +2 and A2 +G let's see what the tangential flux + + align:start position:0% +G let's see what the tangential flux + + + align:start position:0% +G let's see what the tangential flux +density is just outside at the same + + align:start position:0% +density is just outside at the same + + + align:start position:0% +density is just outside at the same +axial + + align:start position:0% + + + + align:start position:0% + +location just outside the flux density + + align:start position:0% +location just outside the flux density + + + align:start position:0% +location just outside the flux density +Falls by more than a factor of 10 to + + align:start position:0% +Falls by more than a factor of 10 to + + + align:start position:0% +Falls by more than a factor of 10 to +0.15 + + align:start position:0% + + + + align:start position:0% + +gal just as the capacitor can be + + align:start position:0% +gal just as the capacitor can be + + + align:start position:0% +gal just as the capacitor can be +constructed to create a uniform electric + + align:start position:0% +constructed to create a uniform electric + + + align:start position:0% +constructed to create a uniform electric +field between the plates with zero field + + align:start position:0% +field between the plates with zero field + + + align:start position:0% +field between the plates with zero field +outside the region bounded by the plates + + align:start position:0% +outside the region bounded by the plates + + + align:start position:0% +outside the region bounded by the plates +so too the long solenoid gives rise to a + + align:start position:0% +so too the long solenoid gives rise to a + + + align:start position:0% +so too the long solenoid gives rise to a +uniform magnetic field throughout the + + align:start position:0% +uniform magnetic field throughout the + + + align:start position:0% +uniform magnetic field throughout the +interior + + align:start position:0% +interior + + + align:start position:0% +interior +region our solenoid length is finite so + + align:start position:0% +region our solenoid length is finite so + + + align:start position:0% +region our solenoid length is finite so +the field inside is only approximately + + align:start position:0% + + + + align:start position:0% + +uniform and the exterior field is only + + align:start position:0% +uniform and the exterior field is only + + + align:start position:0% +uniform and the exterior field is only +approximately zero + + align:start position:0% + + + + align:start position:0% + +the magnetic field along the Z AIS can + + align:start position:0% +the magnetic field along the Z AIS can + + + align:start position:0% +the magnetic field along the Z AIS can +be found by simple integration of the + + align:start position:0% +be found by simple integration of the + + + align:start position:0% +be found by simple integration of the +bosar law the essentially F directed + + align:start position:0% +bosar law the essentially F directed + + + align:start position:0% +bosar law the essentially F directed +current along the entire winding + + align:start position:0% +current along the entire winding + + + align:start position:0% +current along the entire winding +generates a z directed magnetic field + + align:start position:0% +generates a z directed magnetic field + + + align:start position:0% +generates a z directed magnetic field +along the axis of the + + align:start position:0% + + + + align:start position:0% + +cylinder this is the on axis + + align:start position:0% +cylinder this is the on axis + + + align:start position:0% +cylinder this is the on axis +distribution of the axial field + + align:start position:0% +distribution of the axial field + + + align:start position:0% +distribution of the axial field +intensity for our solenoid which has a + + align:start position:0% +intensity for our solenoid which has a + + + align:start position:0% +intensity for our solenoid which has a +length to diameter ratio of 2. + + align:start position:0% +length to diameter ratio of 2. + + + align:start position:0% +length to diameter ratio of 2. +58 we can compare the prediction of this + + align:start position:0% +58 we can compare the prediction of this + + + align:start position:0% +58 we can compare the prediction of this +formula to our experiment here at the + + align:start position:0% +formula to our experiment here at the + + + align:start position:0% +formula to our experiment here at the +end of the + + align:start position:0% +end of the + + + align:start position:0% +end of the +solenoid bosar predicts a flux density + + align:start position:0% +solenoid bosar predicts a flux density + + + align:start position:0% +solenoid bosar predicts a flux density +of about half of the 2 and 1 half G in + + align:start position:0% +of about half of the 2 and 1 half G in + + + align:start position:0% +of about half of the 2 and 1 half G in +the + + align:start position:0% + + + + align:start position:0% + +interior here's the on-axis magnetic + + align:start position:0% +interior here's the on-axis magnetic + + + align:start position:0% +interior here's the on-axis magnetic +field well inside the + + align:start position:0% +field well inside the + + + align:start position:0% +field well inside the +solenoid about 2.3 + + align:start position:0% +solenoid about 2.3 + + + align:start position:0% +solenoid about 2.3 +G here at the end of the coil we measure + + align:start position:0% +G here at the end of the coil we measure + + + align:start position:0% +G here at the end of the coil we measure +about 1.2 G + + align:start position:0% +about 1.2 G + + + align:start position:0% +about 1.2 G +about half of the Interior + + align:start position:0% + + + + align:start position:0% + +field this is where our data points fall + + align:start position:0% +field this is where our data points fall + + + align:start position:0% +field this is where our data points fall +on the theoretical + + align:start position:0% +on the theoretical + + + align:start position:0% +on the theoretical +curve here's the interior + + align:start position:0% +curve here's the interior + + + align:start position:0% +curve here's the interior +Point here's the point at the end of the + + align:start position:0% + + + + align:start position:0% + +coil the accuracy with which Theory and + + align:start position:0% +coil the accuracy with which Theory and + + + align:start position:0% +coil the accuracy with which Theory and +experiment degree is likely to be + + align:start position:0% +experiment degree is likely to be + + + align:start position:0% +experiment degree is likely to be +limited only by such matters as the + + align:start position:0% +limited only by such matters as the + + + align:start position:0% +limited only by such matters as the +uniformity of the winding the car taken + + align:start position:0% +uniformity of the winding the car taken + + + align:start position:0% +uniformity of the winding the car taken +and mounting the probe and the + + align:start position:0% +and mounting the probe and the + + + align:start position:0% +and mounting the probe and the +calibration of the gaus + + align:start position:0% + + + + align:start position:0% + +meter another way to demonstrate the + + align:start position:0% +meter another way to demonstrate the + + + align:start position:0% +meter another way to demonstrate the +discontinuity in magnetic field between + + align:start position:0% +discontinuity in magnetic field between + + + align:start position:0% +discontinuity in magnetic field between +inside and outside the solenoid is to + + align:start position:0% +inside and outside the solenoid is to + + + align:start position:0% +inside and outside the solenoid is to +use this transverse + + align:start position:0% +use this transverse + + + align:start position:0% +use this transverse +probe this probe measures magnetic + + align:start position:0% +probe this probe measures magnetic + + + align:start position:0% +probe this probe measures magnetic +fields transverse to its flat + + align:start position:0% +fields transverse to its flat + + + align:start position:0% +fields transverse to its flat +surface here for example is the on-axis + + align:start position:0% +surface here for example is the on-axis + + + align:start position:0% +surface here for example is the on-axis +field turning the probe by 90° gives a + + align:start position:0% +field turning the probe by 90° gives a + + + align:start position:0% +field turning the probe by 90° gives a +zero signal which shows the field is + + align:start position:0% +zero signal which shows the field is + + + align:start position:0% +zero signal which shows the field is +purely axial + + align:start position:0% + + + + align:start position:0% + +we now place this probe just outside the + + align:start position:0% +we now place this probe just outside the + + + align:start position:0% +we now place this probe just outside the +solenoid in the orientation to measure + + align:start position:0% +solenoid in the orientation to measure + + + align:start position:0% +solenoid in the orientation to measure +the small tangential field + + align:start position:0% +the small tangential field + + + align:start position:0% +the small tangential field +component as the probe passes through + + align:start position:0% +component as the probe passes through + + + align:start position:0% +component as the probe passes through +the current carrying winding the + + align:start position:0% +the current carrying winding the + + + align:start position:0% +the current carrying winding the +magnetic field abruptly Rises to the + + align:start position:0% +magnetic field abruptly Rises to the + + + align:start position:0% +magnetic field abruptly Rises to the +interior field value \ No newline at end of file diff --git a/mgAhDIdbUK8.txt b/mgAhDIdbUK8.txt new file mode 100644 index 0000000000000000000000000000000000000000..d5a43c91b7a9a23bab626f2056889502cdac4ea0 --- /dev/null +++ b/mgAhDIdbUK8.txt @@ -0,0 +1,787 @@ +align:start position:0% + +as before we have a red Poisson process + + align:start position:0% +as before we have a red Poisson process + + + align:start position:0% +as before we have a red Poisson process +and a green Poisson process we merge + + align:start position:0% +and a green Poisson process we merge + + + align:start position:0% +and a green Poisson process we merge +these two processes and we only observe + + align:start position:0% +these two processes and we only observe + + + align:start position:0% +these two processes and we only observe +the merged process here's an interesting + + align:start position:0% +the merged process here's an interesting + + + align:start position:0% +the merged process here's an interesting +question this is an arrival of the + + align:start position:0% +question this is an arrival of the + + + align:start position:0% +question this is an arrival of the +merged process where did it come from is + + align:start position:0% +merged process where did it come from is + + + align:start position:0% +merged process where did it come from is +it red or is it green we cannot know but + + align:start position:0% +it red or is it green we cannot know but + + + align:start position:0% +it red or is it green we cannot know but +can we tell what is the probability that + + align:start position:0% +can we tell what is the probability that + + + align:start position:0% +can we tell what is the probability that +it came from the red stream the way to + + align:start position:0% +it came from the red stream the way to + + + align:start position:0% +it came from the red stream the way to +answer this question is to look at the + + align:start position:0% +answer this question is to look at the + + + align:start position:0% +answer this question is to look at the +table of all the things that can happen + + align:start position:0% +table of all the things that can happen + + + align:start position:0% +table of all the things that can happen +during a little interval around that + + align:start position:0% +during a little interval around that + + + align:start position:0% +during a little interval around that +particular time in which we've had an + + align:start position:0% +particular time in which we've had an + + + align:start position:0% +particular time in which we've had an +arrival we are told that there was an + + align:start position:0% +arrival we are told that there was an + + + align:start position:0% +arrival we are told that there was an +arrival at time T or an arrival during + + align:start position:0% +arrival at time T or an arrival during + + + align:start position:0% +arrival at time T or an arrival during +an interval a small interval around time + + align:start position:0% +an interval a small interval around time + + + align:start position:0% +an interval a small interval around time +T this means that we are told that this + + align:start position:0% +T this means that we are told that this + + + align:start position:0% +T this means that we are told that this +event here has happened given this + + align:start position:0% +event here has happened given this + + + align:start position:0% +event here has happened given this +information what is the conditional + + align:start position:0% +information what is the conditional + + + align:start position:0% +information what is the conditional +probability that actually this event + + align:start position:0% +probability that actually this event + + + align:start position:0% +probability that actually this event +here occurred this is just the fraction + + align:start position:0% +here occurred this is just the fraction + + + align:start position:0% +here occurred this is just the fraction +of this probability divided by the total + + align:start position:0% +of this probability divided by the total + + + align:start position:0% +of this probability divided by the total +probability of the conditioning event so + + align:start position:0% +probability of the conditioning event so + + + align:start position:0% +probability of the conditioning event so +the answer is lambda 1 divided by lambda + + align:start position:0% +the answer is lambda 1 divided by lambda + + + align:start position:0% +the answer is lambda 1 divided by lambda +1 plus lambda 2 does this answer make + + align:start position:0% +1 plus lambda 2 does this answer make + + + align:start position:0% +1 plus lambda 2 does this answer make +sense 1 suppose that lambda 1 and lambda + + align:start position:0% +sense 1 suppose that lambda 1 and lambda + + + align:start position:0% +sense 1 suppose that lambda 1 and lambda +2 were equal in that case by symmetry + + align:start position:0% +2 were equal in that case by symmetry + + + align:start position:0% +2 were equal in that case by symmetry +when an arrival comes it should be + + align:start position:0% +when an arrival comes it should be + + + align:start position:0% +when an arrival comes it should be +equally likely to have come either from + + align:start position:0% +equally likely to have come either from + + + align:start position:0% +equally likely to have come either from +the red or from the green stream and + + align:start position:0% +the red or from the green stream and + + + align:start position:0% +the red or from the green stream and +this is consistent with this answer we + + align:start position:0% +this is consistent with this answer we + + + align:start position:0% +this is consistent with this answer we +can reason similarly for a slightly + + align:start position:0% +can reason similarly for a slightly + + + align:start position:0% +can reason similarly for a slightly +different question you wait until the + + align:start position:0% +different question you wait until the + + + align:start position:0% +different question you wait until the +case arrival let's say the third arrival + + align:start position:0% +case arrival let's say the third arrival + + + align:start position:0% +case arrival let's say the third arrival +where did that arrival come from well + + align:start position:0% +where did that arrival come from well + + + align:start position:0% +where did that arrival come from well +that gate arrival occurred during a + + align:start position:0% +that gate arrival occurred during a + + + align:start position:0% +that gate arrival occurred during a +specific little time interval and + + align:start position:0% +specific little time interval and + + + align:start position:0% +specific little time interval and +conditioning on it having occurred + + align:start position:0% +conditioning on it having occurred + + + align:start position:0% +conditioning on it having occurred +during that particular time interval we + + align:start position:0% +during that particular time interval we + + + align:start position:0% +during that particular time interval we +can then repeat the reasoning that we + + align:start position:0% +can then repeat the reasoning that we + + + align:start position:0% +can then repeat the reasoning that we +had here and argue that given that we + + align:start position:0% +had here and argue that given that we + + + align:start position:0% +had here and argue that given that we +had an arrival it just happens to be the + + align:start position:0% +had an arrival it just happens to be the + + + align:start position:0% +had an arrival it just happens to be the +third arrival + + align:start position:0% +third arrival + + + align:start position:0% +third arrival +during that time interval there's going + + align:start position:0% +during that time interval there's going + + + align:start position:0% +during that time interval there's going +to be this particular conditional + + align:start position:0% +to be this particular conditional + + + align:start position:0% +to be this particular conditional +probability that it came from the red + + align:start position:0% +probability that it came from the red + + + align:start position:0% +probability that it came from the red +stream so we obtained the same answer + + align:start position:0% +stream so we obtained the same answer + + + align:start position:0% +stream so we obtained the same answer +once more now this arrival came from one + + align:start position:0% +once more now this arrival came from one + + + align:start position:0% +once more now this arrival came from one +of the two streams with some + + align:start position:0% +of the two streams with some + + + align:start position:0% +of the two streams with some +probabilities this arrival came from one + + align:start position:0% +probabilities this arrival came from one + + + align:start position:0% +probabilities this arrival came from one +of the two streams with some + + align:start position:0% +of the two streams with some + + + align:start position:0% +of the two streams with some +probabilities does the origin of this + + align:start position:0% +probabilities does the origin of this + + + align:start position:0% +probabilities does the origin of this +arrival affect or depend on the origin + + align:start position:0% +arrival affect or depend on the origin + + + align:start position:0% +arrival affect or depend on the origin +of that arrival because we have assumed + + align:start position:0% +of that arrival because we have assumed + + + align:start position:0% +of that arrival because we have assumed +independence across time for each one of + + align:start position:0% +independence across time for each one of + + + align:start position:0% +independence across time for each one of +the processes that we started with and + + align:start position:0% +the processes that we started with and + + + align:start position:0% +the processes that we started with and +therefore we also have the same thing + + align:start position:0% +therefore we also have the same thing + + + align:start position:0% +therefore we also have the same thing +for the merged process whatever has to + + align:start position:0% +for the merged process whatever has to + + + align:start position:0% +for the merged process whatever has to +do with events during this interval is + + align:start position:0% +do with events during this interval is + + + align:start position:0% +do with events during this interval is +independent from anything that has to do + + align:start position:0% +independent from anything that has to do + + + align:start position:0% +independent from anything that has to do +with events in that interval and because + + align:start position:0% +with events in that interval and because + + + align:start position:0% +with events in that interval and because +of this one can argue formally but + + align:start position:0% +of this one can argue formally but + + + align:start position:0% +of this one can argue formally but +hopefully this is intuitive enough that + + align:start position:0% +hopefully this is intuitive enough that + + + align:start position:0% +hopefully this is intuitive enough that +the origin of this arrival and the + + align:start position:0% +the origin of this arrival and the + + + align:start position:0% +the origin of this arrival and the +origin of that arrival are independent + + align:start position:0% +origin of that arrival are independent + + + align:start position:0% +origin of that arrival are independent +events and now that we have this + + align:start position:0% +events and now that we have this + + + align:start position:0% +events and now that we have this +property we can answer questions such as + + align:start position:0% +property we can answer questions such as + + + align:start position:0% +property we can answer questions such as +the following we've had ten arrivals so + + align:start position:0% +the following we've had ten arrivals so + + + align:start position:0% +the following we've had ten arrivals so +far what is the probability that exactly + + align:start position:0% +far what is the probability that exactly + + + align:start position:0% +far what is the probability that exactly +four out of these ten are read each one + + align:start position:0% +four out of these ten are read each one + + + align:start position:0% +four out of these ten are read each one +of those arrivals has this probability + + align:start position:0% +of those arrivals has this probability + + + align:start position:0% +of those arrivals has this probability +of being read the origin of different + + align:start position:0% +of being read the origin of different + + + align:start position:0% +of being read the origin of different +arrivals are independent of each other + + align:start position:0% +arrivals are independent of each other + + + align:start position:0% +arrivals are independent of each other +so essentially we're dealing with ten + + align:start position:0% +so essentially we're dealing with ten + + + align:start position:0% +so essentially we're dealing with ten +Bernoulli trials each of which has two + + align:start position:0% +Bernoulli trials each of which has two + + + align:start position:0% +Bernoulli trials each of which has two +possible outcomes red or green and is + + align:start position:0% +possible outcomes red or green and is + + + align:start position:0% +possible outcomes red or green and is +red with this particular probability + + align:start position:0% +red with this particular probability + + + align:start position:0% +red with this particular probability +therefore the answer is going to be + + align:start position:0% +therefore the answer is going to be + + + align:start position:0% +therefore the answer is going to be +given by the binomial probabilities + + align:start position:0% +given by the binomial probabilities + + + align:start position:0% +given by the binomial probabilities +which is the probability of having four + + align:start position:0% +which is the probability of having four + + + align:start position:0% +which is the probability of having four +successes in ten trials and we obtain + + align:start position:0% +successes in ten trials and we obtain + + + align:start position:0% +successes in ten trials and we obtain +lambda one over lambda 1 plus lambda 2 + + align:start position:0% +lambda one over lambda 1 plus lambda 2 + + + align:start position:0% +lambda one over lambda 1 plus lambda 2 +that's the probability of a red to the + + align:start position:0% +that's the probability of a red to the + + + align:start position:0% +that's the probability of a red to the +number of red arrivals and then the + + align:start position:0% +number of red arrivals and then the + + + align:start position:0% +number of red arrivals and then the +remaining probability one minus that + + align:start position:0% +remaining probability one minus that + + + align:start position:0% +remaining probability one minus that +which is lambda two over lambda one plus + + align:start position:0% +which is lambda two over lambda one plus + + + align:start position:0% +which is lambda two over lambda one plus +lambda2 to the remaining power which is + + align:start position:0% +lambda2 to the remaining power which is + + + align:start position:0% +lambda2 to the remaining power which is +equal to six + + align:start position:0% +equal to six + + + align:start position:0% +equal to six +so to summarize each one of the arrivals + + align:start position:0% +so to summarize each one of the arrivals + + + align:start position:0% +so to summarize each one of the arrivals +in the merged process has a certain + + align:start position:0% +in the merged process has a certain + + + align:start position:0% +in the merged process has a certain +probability of being a red arrival or a + + align:start position:0% +probability of being a red arrival or a + + + align:start position:0% +probability of being a red arrival or a +green arrival which one of the two is + + align:start position:0% +green arrival which one of the two is + + + align:start position:0% +green arrival which one of the two is +the case we can think of it as an + + align:start position:0% +the case we can think of it as an + + + align:start position:0% +the case we can think of it as an +outcome of a Bernoulli trial and the + + align:start position:0% +outcome of a Bernoulli trial and the + + + align:start position:0% +outcome of a Bernoulli trial and the +Bernoulli trials associated with + + align:start position:0% +Bernoulli trials associated with + + + align:start position:0% +Bernoulli trials associated with +different arrivals are independent of + + align:start position:0% +different arrivals are independent of + + + align:start position:0% +different arrivals are independent of +each other as a consequence of the + + align:start position:0% +each other as a consequence of the + + + align:start position:0% +each other as a consequence of the +independence of Poisson processes across + + align:start position:0% +independence of Poisson processes across + + + align:start position:0% +independence of Poisson processes across +time \ No newline at end of file diff --git a/mvjXFh4P08I.txt b/mvjXFh4P08I.txt new file mode 100644 index 0000000000000000000000000000000000000000..e32592a553c0b09472e618f96c25190cf81faf68 --- /dev/null +++ b/mvjXFh4P08I.txt @@ -0,0 +1,7955 @@ +align:start position:0% + +hey here we go a couple of things sorry + + align:start position:0% +hey here we go a couple of things sorry + + + align:start position:0% +hey here we go a couple of things sorry +I forgot to bring candy but it'll be on + + align:start position:0% +I forgot to bring candy but it'll be on + + + align:start position:0% +I forgot to bring candy but it'll be on +sale next week so we can probably bring + + align:start position:0% +sale next week so we can probably bring + + + align:start position:0% +sale next week so we can probably bring +it next week but I walking over I + + align:start position:0% +it next week but I walking over I + + + align:start position:0% +it next week but I walking over I +thought boy those of you who are here + + align:start position:0% +thought boy those of you who are here + + + align:start position:0% +thought boy those of you who are here +deserves some candy but I've just tried + + align:start position:0% +deserves some candy but I've just tried + + + align:start position:0% +deserves some candy but I've just tried +to sprinkle in a few interesting slides + + align:start position:0% +to sprinkle in a few interesting slides + + + align:start position:0% +to sprinkle in a few interesting slides +for your benefit I saw this on the MIT + + align:start position:0% +for your benefit I saw this on the MIT + + + align:start position:0% +for your benefit I saw this on the MIT +news of the day and I thought that was + + align:start position:0% +news of the day and I thought that was + + + align:start position:0% +news of the day and I thought that was +really cool who would have thought to + + align:start position:0% +really cool who would have thought to + + + align:start position:0% +really cool who would have thought to +turn the giant dome into a Halloween + + align:start position:0% +turn the giant dome into a Halloween + + + align:start position:0% +turn the giant dome into a Halloween +pumpkins and I was also jealous this + + align:start position:0% +pumpkins and I was also jealous this + + + align:start position:0% +pumpkins and I was also jealous this +morning when my husband got ready to go + + align:start position:0% +morning when my husband got ready to go + + + align:start position:0% +morning when my husband got ready to go +work in the emergency room and he put on + + align:start position:0% +work in the emergency room and he put on + + + align:start position:0% +work in the emergency room and he put on +his Star Trek outfit so I didn't even + + align:start position:0% +his Star Trek outfit so I didn't even + + + align:start position:0% +his Star Trek outfit so I didn't even +have it because I don't usually get to + + align:start position:0% +have it because I don't usually get to + + + align:start position:0% +have it because I don't usually get to +actually have a class on the day of + + align:start position:0% +actually have a class on the day of + + + align:start position:0% +actually have a class on the day of +Halloween or so he headed off I think + + align:start position:0% +Halloween or so he headed off I think + + + align:start position:0% +Halloween or so he headed off I think +people are unfortunately gonna expect + + align:start position:0% +people are unfortunately gonna expect + + + align:start position:0% +people are unfortunately gonna expect +him to be able to really fix things very + + align:start position:0% +him to be able to really fix things very + + + align:start position:0% +him to be able to really fix things very +readily in the emergency room today + + align:start position:0% +readily in the emergency room today + + + align:start position:0% +readily in the emergency room today +because he's gonna have all those extra + + align:start position:0% +because he's gonna have all those extra + + + align:start position:0% +because he's gonna have all those extra +powers that he doesn't usually have but + + align:start position:0% +powers that he doesn't usually have but + + + align:start position:0% +powers that he doesn't usually have but +anyway anyway so actually it's kind of a + + align:start position:0% +anyway anyway so actually it's kind of a + + + align:start position:0% +anyway anyway so actually it's kind of a +good day for a lecture Halloween because + + align:start position:0% +good day for a lecture Halloween because + + + align:start position:0% +good day for a lecture Halloween because +we're going to talk about the + + align:start position:0% +we're going to talk about the + + + align:start position:0% +we're going to talk about the +fight-or-flight response which is a + + align:start position:0% +fight-or-flight response which is a + + + align:start position:0% +fight-or-flight response which is a +great paradigm for cellular signaling so + + align:start position:0% +great paradigm for cellular signaling so + + + align:start position:0% +great paradigm for cellular signaling so +you're gonna see how signaling really + + align:start position:0% +you're gonna see how signaling really + + + align:start position:0% +you're gonna see how signaling really +works in action because what one has to + + align:start position:0% +works in action because what one has to + + + align:start position:0% +works in action because what one has to +think about with respect to cellular + + align:start position:0% +think about with respect to cellular + + + align:start position:0% +think about with respect to cellular +signaling is that it's dynamic and + + align:start position:0% +signaling is that it's dynamic and + + + align:start position:0% +signaling is that it's dynamic and +transient and when we look at the + + align:start position:0% +transient and when we look at the + + + align:start position:0% +transient and when we look at the +molecular details of the switches that + + align:start position:0% +molecular details of the switches that + + + align:start position:0% +molecular details of the switches that +enable dynamics and transient behavior + + align:start position:0% +enable dynamics and transient behavior + + + align:start position:0% +enable dynamics and transient behavior +in cells you're going to see how + + align:start position:0% +in cells you're going to see how + + + align:start position:0% +in cells you're going to see how +perfectly adapted they are for these + + align:start position:0% +perfectly adapted they are for these + + + align:start position:0% +perfectly adapted they are for these +types of responses that have to be + + align:start position:0% +types of responses that have to be + + + align:start position:0% +types of responses that have to be +carried out in cells are in organs in + + align:start position:0% +carried out in cells are in organs in + + + align:start position:0% +carried out in cells are in organs in +order to respond to a particular signal + + align:start position:0% +order to respond to a particular signal + + + align:start position:0% +order to respond to a particular signal +rapidly and with a definitive time frame + + align:start position:0% +rapidly and with a definitive time frame + + + align:start position:0% +rapidly and with a definitive time frame +and then have that signal then stopped + + align:start position:0% +and then have that signal then stopped + + + align:start position:0% +and then have that signal then stopped +once the the time frame is passed so I + + align:start position:0% +once the the time frame is passed so I + + + align:start position:0% +once the the time frame is passed so I +really want to sort of stress to you the + + align:start position:0% +really want to sort of stress to you the + + + align:start position:0% +really want to sort of stress to you the +characteristics of signaling that that + + align:start position:0% +characteristics of signaling that that + + + align:start position:0% +characteristics of signaling that that +can emerge just by knowing about two + + align:start position:0% +can emerge just by knowing about two + + + align:start position:0% +can emerge just by knowing about two +particular cell by cellular switches + + align:start position:0% +particular cell by cellular switches + + + align:start position:0% +particular cell by cellular switches +knowing the molecular details of those + + align:start position:0% +knowing the molecular details of those + + + align:start position:0% +knowing the molecular details of those +switches to + + align:start position:0% +switches to + + + align:start position:0% +switches to +understand then when we look at them in + + align:start position:0% +understand then when we look at them in + + + align:start position:0% +understand then when we look at them in +action in a couple of cellular signaling + + align:start position:0% +action in a couple of cellular signaling + + + align:start position:0% +action in a couple of cellular signaling +pathways then we'll see how adapted + + align:start position:0% +pathways then we'll see how adapted + + + align:start position:0% +pathways then we'll see how adapted +those signals are and the great thing + + align:start position:0% +those signals are and the great thing + + + align:start position:0% +those signals are and the great thing +about biology is the once you learn a + + align:start position:0% +about biology is the once you learn a + + + align:start position:0% +about biology is the once you learn a +few very specific things then those + + align:start position:0% +few very specific things then those + + + align:start position:0% +few very specific things then those +often get reused in nature so the + + align:start position:0% +often get reused in nature so the + + + align:start position:0% +often get reused in nature so the +cellular signals that I'm going to + + align:start position:0% +cellular signals that I'm going to + + + align:start position:0% +cellular signals that I'm going to +describe to you are used again and again + + align:start position:0% +describe to you are used again and again + + + align:start position:0% +describe to you are used again and again +in different formats to create different + + align:start position:0% +in different formats to create different + + + align:start position:0% +in different formats to create different +signaling pathways so it's not at every + + align:start position:0% +signaling pathways so it's not at every + + + align:start position:0% +signaling pathways so it's not at every +pathway in every cell in the body has + + align:start position:0% +pathway in every cell in the body has + + + align:start position:0% +pathway in every cell in the body has +different nuances it has general + + align:start position:0% +different nuances it has general + + + align:start position:0% +different nuances it has general +paradigms that we can learn about and + + align:start position:0% +paradigms that we can learn about and + + + align:start position:0% +paradigms that we can learn about and +understand all right so the key feature + + align:start position:0% +understand all right so the key feature + + + align:start position:0% +understand all right so the key feature +is then to think about the the the the + + align:start position:0% +is then to think about the the the the + + + align:start position:0% +is then to think about the the the the +molecular basis of these switches so + + align:start position:0% +molecular basis of these switches so + + + align:start position:0% +molecular basis of these switches so +last time I was talking to you about + + align:start position:0% +last time I was talking to you about + + + align:start position:0% +last time I was talking to you about +cellular signaling and remember there's + + align:start position:0% +cellular signaling and remember there's + + + align:start position:0% +cellular signaling and remember there's +always a signal a response and an output + + align:start position:0% +always a signal a response and an output + + + align:start position:0% +always a signal a response and an output +so something happens it's a signal it's + + align:start position:0% +so something happens it's a signal it's + + + align:start position:0% +so something happens it's a signal it's +usually a molecule of some kind outside + + align:start position:0% +usually a molecule of some kind outside + + + align:start position:0% +usually a molecule of some kind outside +the cell or able to diffuse into the + + align:start position:0% +the cell or able to diffuse into the + + + align:start position:0% +the cell or able to diffuse into the +cell as a function of that signal + + align:start position:0% +cell as a function of that signal + + + align:start position:0% +cell as a function of that signal +there's a response so this is molecular + + align:start position:0% + + + + align:start position:0% + +the response obviously is biochemical + + align:start position:0% + + + + align:start position:0% + +and the output is biological so I want + + align:start position:0% +and the output is biological so I want + + + align:start position:0% +and the output is biological so I want +you to sort of think about these as we + + align:start position:0% +you to sort of think about these as we + + + align:start position:0% +you to sort of think about these as we +look at pathways what's really my output + + align:start position:0% +look at pathways what's really my output + + + align:start position:0% +look at pathways what's really my output +at the end of a particular signaling + + align:start position:0% +at the end of a particular signaling + + + align:start position:0% +at the end of a particular signaling +pathway what was my input how did it get + + align:start position:0% +pathway what was my input how did it get + + + align:start position:0% +pathway what was my input how did it get +to the cell how does it have a dramatic + + align:start position:0% +to the cell how does it have a dramatic + + + align:start position:0% +to the cell how does it have a dramatic +effect on the cell as a whole how does + + align:start position:0% +effect on the cell as a whole how does + + + align:start position:0% +effect on the cell as a whole how does +the timing and action of this effect + + align:start position:0% +the timing and action of this effect + + + align:start position:0% +the timing and action of this effect +occur so rapidly + + align:start position:0% +occur so rapidly + + + align:start position:0% +occur so rapidly +so we talked last time about different + + align:start position:0% +so we talked last time about different + + + align:start position:0% +so we talked last time about different +types of signals those that mostly occur + + align:start position:0% +types of signals those that mostly occur + + + align:start position:0% +types of signals those that mostly occur +in this in the cytoplasm of the cell + + align:start position:0% +in this in the cytoplasm of the cell + + + align:start position:0% +in this in the cytoplasm of the cell +with signals that are able to diffuse + + align:start position:0% +with signals that are able to diffuse + + + align:start position:0% +with signals that are able to diffuse +across the plasma membrane and bind to + + align:start position:0% +across the plasma membrane and bind to + + + align:start position:0% +across the plasma membrane and bind to +an intracellular receptor and then cause + + align:start position:0% +an intracellular receptor and then cause + + + align:start position:0% +an intracellular receptor and then cause +an action but really the most important + + align:start position:0% +an action but really the most important + + + align:start position:0% +an action but really the most important +ones for today + + align:start position:0% +ones for today + + + align:start position:0% +ones for today +going to be the types of receptors that + + align:start position:0% +going to be the types of receptors that + + + align:start position:0% +going to be the types of receptors that +span the membrane and the reason why + + align:start position:0% +span the membrane and the reason why + + + align:start position:0% +span the membrane and the reason why +these are much more significant they're + + align:start position:0% +these are much more significant they're + + + align:start position:0% +these are much more significant they're +more in number they're more predominant + + align:start position:0% +more in number they're more predominant + + + align:start position:0% +more in number they're more predominant +is if you have a membrane spanning + + align:start position:0% +is if you have a membrane spanning + + + align:start position:0% +is if you have a membrane spanning +receptor you have the opportunity to use + + align:start position:0% +receptor you have the opportunity to use + + + align:start position:0% +receptor you have the opportunity to use +signals of very very different types + + align:start position:0% +signals of very very different types + + + align:start position:0% +signals of very very different types +small polar molecules small proteins + + align:start position:0% +small polar molecules small proteins + + + align:start position:0% +small polar molecules small proteins +lipids amino acids carbohydrates you've + + align:start position:0% +lipids amino acids carbohydrates you've + + + align:start position:0% +lipids amino acids carbohydrates you've +got a much larger range of signals than + + align:start position:0% +got a much larger range of signals than + + + align:start position:0% +got a much larger range of signals than +you could possibly have + + align:start position:0% +you could possibly have + + + align:start position:0% +you could possibly have +if you restricted yourselves to the type + + align:start position:0% +if you restricted yourselves to the type + + + align:start position:0% +if you restricted yourselves to the type +of signals that can cross the cell + + align:start position:0% +of signals that can cross the cell + + + align:start position:0% +of signals that can cross the cell +membrane those are very limited to + + align:start position:0% +membrane those are very limited to + + + align:start position:0% +membrane those are very limited to +nonpolar small molecules that can get + + align:start position:0% +nonpolar small molecules that can get + + + align:start position:0% +nonpolar small molecules that can get +across the membrane the more dominant + + align:start position:0% +across the membrane the more dominant + + + align:start position:0% +across the membrane the more dominant +types of signals are going to be the + + align:start position:0% +types of signals are going to be the + + + align:start position:0% +types of signals are going to be the +ones that are outside the cell they + + align:start position:0% +ones that are outside the cell they + + + align:start position:0% +ones that are outside the cell they +arrive at a cell surface they bind to + + align:start position:0% +arrive at a cell surface they bind to + + + align:start position:0% +arrive at a cell surface they bind to +attract a receptor that is trans + + align:start position:0% +attract a receptor that is trans + + + align:start position:0% +attract a receptor that is trans +membrane and transduce a signal from the + + align:start position:0% +membrane and transduce a signal from the + + + align:start position:0% +membrane and transduce a signal from the +outside to the inside so that's that's + + align:start position:0% +outside to the inside so that's that's + + + align:start position:0% +outside to the inside so that's that's +an important term here the process of + + align:start position:0% +an important term here the process of + + + align:start position:0% +an important term here the process of +transducing external information - + + align:start position:0% +transducing external information - + + + align:start position:0% +transducing external information - +internal information so when we started + + align:start position:0% +internal information so when we started + + + align:start position:0% +internal information so when we started +the course we were really thinking about + + align:start position:0% +the course we were really thinking about + + + align:start position:0% +the course we were really thinking about +laying down the cellular membrane as an + + align:start position:0% +laying down the cellular membrane as an + + + align:start position:0% +laying down the cellular membrane as an +encased environment where things could + + align:start position:0% +encased environment where things could + + + align:start position:0% +encased environment where things could +occur at high concentrations you could + + align:start position:0% +occur at high concentrations you could + + + align:start position:0% +occur at high concentrations you could +set up systems that were functional + + align:start position:0% +set up systems that were functional + + + align:start position:0% +set up systems that were functional +within membranes but in doing that + + align:start position:0% +within membranes but in doing that + + + align:start position:0% +within membranes but in doing that +within a membrane encased area in doing + + align:start position:0% +within a membrane encased area in doing + + + align:start position:0% +within a membrane encased area in doing +that you've built a formidable barrier + + align:start position:0% +that you've built a formidable barrier + + + align:start position:0% +that you've built a formidable barrier +around the cell so the types of + + align:start position:0% +around the cell so the types of + + + align:start position:0% +around the cell so the types of +receptors that we'll talk about are + + align:start position:0% +receptors that we'll talk about are + + + align:start position:0% +receptors that we'll talk about are +those that have adapted to take this + + align:start position:0% +those that have adapted to take this + + + align:start position:0% +those that have adapted to take this +external information into the cell and + + align:start position:0% +external information into the cell and + + + align:start position:0% +external information into the cell and +then have a cellular consequence occur + + align:start position:0% +then have a cellular consequence occur + + + align:start position:0% +then have a cellular consequence occur +so I'm going to talk to you about two + + align:start position:0% +so I'm going to talk to you about two + + + align:start position:0% +so I'm going to talk to you about two +specific types of cellular switches and + + align:start position:0% +specific types of cellular switches and + + + align:start position:0% +specific types of cellular switches and +they're going to be intracellular + + align:start position:0% + + + + align:start position:0% + +and we're going to be referring back to + + align:start position:0% +and we're going to be referring back to + + + align:start position:0% +and we're going to be referring back to +these because they're going to be + + align:start position:0% +these because they're going to be + + + align:start position:0% +these because they're going to be +important as we dissect a signaling + + align:start position:0% +important as we dissect a signaling + + + align:start position:0% +important as we dissect a signaling +pathway so the first type so stand aside + + align:start position:0% +pathway so the first type so stand aside + + + align:start position:0% +pathway so the first type so stand aside +a moment put aside a moment the actual + + align:start position:0% +a moment put aside a moment the actual + + + align:start position:0% +a moment put aside a moment the actual +process of a signal binding the response + + align:start position:0% +process of a signal binding the response + + + align:start position:0% +process of a signal binding the response +both biologic biochemical and biological + + align:start position:0% +both biologic biochemical and biological + + + align:start position:0% +both biologic biochemical and biological +let's look first at the molecular detail + + align:start position:0% +let's look first at the molecular detail + + + align:start position:0% +let's look first at the molecular detail +of these switches and see how they are + + align:start position:0% +of these switches and see how they are + + + align:start position:0% +of these switches and see how they are +adapted to their function and the first + + align:start position:0% +adapted to their function and the first + + + align:start position:0% +adapted to their function and the first +type of cellular switch i want to known + + align:start position:0% +type of cellular switch i want to known + + + align:start position:0% +type of cellular switch i want to known +as g proteins the G is because they bind + + align:start position:0% +as g proteins the G is because they bind + + + align:start position:0% +as g proteins the G is because they bind +guanidine nucleotides so that's why + + align:start position:0% +guanidine nucleotides so that's why + + + align:start position:0% +guanidine nucleotides so that's why +they're called G proteins they're small + + align:start position:0% +they're called G proteins they're small + + + align:start position:0% +they're called G proteins they're small +proteins that bind G DP or g GP so this + + align:start position:0% +proteins that bind G DP or g GP so this + + + align:start position:0% +proteins that bind G DP or g GP so this +is the guanine nucleotide that has + + align:start position:0% +is the guanine nucleotide that has + + + align:start position:0% +is the guanine nucleotide that has +either two phosphates guanosine + + align:start position:0% +either two phosphates guanosine + + + align:start position:0% +either two phosphates guanosine +diphosphate or triphosphate so there may + + align:start position:0% +diphosphate or triphosphate so there may + + + align:start position:0% +diphosphate or triphosphate so there may +or may not be a third phosphate here and + + align:start position:0% +or may not be a third phosphate here and + + + align:start position:0% +or may not be a third phosphate here and +the g proteins bind them and the + + align:start position:0% +the g proteins bind them and the + + + align:start position:0% +the g proteins bind them and the +dynamics of the situation are that when + + align:start position:0% +dynamics of the situation are that when + + + align:start position:0% +dynamics of the situation are that when +g proteins are bound to gdp they are + + align:start position:0% +g proteins are bound to gdp they are + + + align:start position:0% +g proteins are bound to gdp they are +inactive the switch is off there's an + + align:start position:0% +inactive the switch is off there's an + + + align:start position:0% +inactive the switch is off there's an +aspect of the structure and it's very + + align:start position:0% +aspect of the structure and it's very + + + align:start position:0% +aspect of the structure and it's very +dependent on how many phosphates there + + align:start position:0% +dependent on how many phosphates there + + + align:start position:0% +dependent on how many phosphates there +are in this structure but it's when it's + + align:start position:0% +are in this structure but it's when it's + + + align:start position:0% +are in this structure but it's when it's +bound to the diphosphate variant of the + + align:start position:0% +bound to the diphosphate variant of the + + + align:start position:0% +bound to the diphosphate variant of the +nucleotide then it's an off switch and + + align:start position:0% +nucleotide then it's an off switch and + + + align:start position:0% +nucleotide then it's an off switch and +when it's bound to gtp it's an on switch + + align:start position:0% +when it's bound to gtp it's an on switch + + + align:start position:0% +when it's bound to gtp it's an on switch +and it's active so this is a the + + align:start position:0% +and it's active so this is a the + + + align:start position:0% +and it's active so this is a the +molecular basis of one of the switches + + align:start position:0% +molecular basis of one of the switches + + + align:start position:0% +molecular basis of one of the switches +they relies on the + + align:start position:0% +they relies on the + + + align:start position:0% +they relies on the +the conformational dynamics of these + + align:start position:0% +the conformational dynamics of these + + + align:start position:0% +the conformational dynamics of these +small G proteins and when that shape is + + align:start position:0% +small G proteins and when that shape is + + + align:start position:0% +small G proteins and when that shape is +quite different if it's bound to + + align:start position:0% +quite different if it's bound to + + + align:start position:0% +quite different if it's bound to +guanosine diphosphate or triphosphate + + align:start position:0% +guanosine diphosphate or triphosphate + + + align:start position:0% +guanosine diphosphate or triphosphate +and we'll take a look in a moment and + + align:start position:0% +and we'll take a look in a moment and + + + align:start position:0% +and we'll take a look in a moment and +how the structure the shape changes the + + align:start position:0% +how the structure the shape changes the + + + align:start position:0% +how the structure the shape changes the +shape shifts upon binding the + + align:start position:0% +shape shifts upon binding the + + + align:start position:0% +shape shifts upon binding the +triphosphate analog so this is a dynamic + + align:start position:0% +triphosphate analog so this is a dynamic + + + align:start position:0% +triphosphate analog so this is a dynamic +inter conversion when the GTP is + + align:start position:0% +inter conversion when the GTP is + + + align:start position:0% +inter conversion when the GTP is +hydrolyzed you go back to the gdp bound + + align:start position:0% +hydrolyzed you go back to the gdp bound + + + align:start position:0% +hydrolyzed you go back to the gdp bound +state the off state and there are a + + align:start position:0% +state the off state and there are a + + + align:start position:0% +state the off state and there are a +variety of proteins that actually help + + align:start position:0% +variety of proteins that actually help + + + align:start position:0% +variety of proteins that actually help +these processes which we won't talk + + align:start position:0% +these processes which we won't talk + + + align:start position:0% +these processes which we won't talk +about in any detail the main thing that + + align:start position:0% +about in any detail the main thing that + + + align:start position:0% +about in any detail the main thing that +you want to remember is that when the g + + align:start position:0% +you want to remember is that when the g + + + align:start position:0% +you want to remember is that when the g +proteins are bound to gtp they're in a + + align:start position:0% +proteins are bound to gtp they're in a + + + align:start position:0% +proteins are bound to gtp they're in a +non state GDP they're in an off state + + align:start position:0% +non state GDP they're in an off state + + + align:start position:0% +non state GDP they're in an off state +and that's shown in this cartoon and + + align:start position:0% +and that's shown in this cartoon and + + + align:start position:0% +and that's shown in this cartoon and +here I should be able to if all goes + + align:start position:0% +here I should be able to if all goes + + + align:start position:0% +here I should be able to if all goes +according to plan show you the structure + + align:start position:0% +according to plan show you the structure + + + align:start position:0% +according to plan show you the structure +of a GTP analogue bound to a g protein + + align:start position:0% +of a GTP analogue bound to a g protein + + + align:start position:0% +of a GTP analogue bound to a g protein +so let's this little guys twirling + + align:start position:0% +so let's this little guys twirling + + + align:start position:0% +so let's this little guys twirling +around he's settled down a little bit + + align:start position:0% +around he's settled down a little bit + + + align:start position:0% +around he's settled down a little bit +the key thing you want to look at is + + align:start position:0% +the key thing you want to look at is + + + align:start position:0% +the key thing you want to look at is +where it's magenta and cyan the + + align:start position:0% +where it's magenta and cyan the + + + align:start position:0% +where it's magenta and cyan the +structure of the GDP and gtp bound g + + align:start position:0% +structure of the GDP and gtp bound g + + + align:start position:0% +structure of the GDP and gtp bound g +protein are very very similar but big + + align:start position:0% +protein are very very similar but big + + + align:start position:0% +protein are very very similar but big +changes happen in the yellow which is + + align:start position:0% +changes happen in the yellow which is + + + align:start position:0% +changes happen in the yellow which is +the gdp-bound form and the red which is + + align:start position:0% +the gdp-bound form and the red which is + + + align:start position:0% +the gdp-bound form and the red which is +the GT bound form let me go back again + + align:start position:0% +the GT bound form let me go back again + + + align:start position:0% +the GT bound form let me go back again +so you can see that one more time so in + + align:start position:0% +so you can see that one more time so in + + + align:start position:0% +so you can see that one more time so in +the GT gtp-bound form a portion of the + + align:start position:0% +the GT gtp-bound form a portion of the + + + align:start position:0% +the GT gtp-bound form a portion of the +protein swings around and binds to that + + align:start position:0% +protein swings around and binds to that + + + align:start position:0% +protein swings around and binds to that +third phosphate on the gtp and forms a + + align:start position:0% +third phosphate on the gtp and forms a + + + align:start position:0% +third phosphate on the gtp and forms a +different shape to the structure and + + align:start position:0% +different shape to the structure and + + + align:start position:0% +different shape to the structure and +that's a dynamic change that's + + align:start position:0% +that's a dynamic change that's + + + align:start position:0% +that's a dynamic change that's +responsible for activation when it's + + align:start position:0% +responsible for activation when it's + + + align:start position:0% +responsible for activation when it's +just D GDP that's shorter there's + + align:start position:0% +just D GDP that's shorter there's + + + align:start position:0% +just D GDP that's shorter there's +nothing for that red arm to bind and so + + align:start position:0% +nothing for that red arm to bind and so + + + align:start position:0% +nothing for that red arm to bind and so +it's much more of a floppy structure + + align:start position:0% +it's much more of a floppy structure + + + align:start position:0% +it's much more of a floppy structure +what I want you to notice in that yellow + + align:start position:0% +what I want you to notice in that yellow + + + align:start position:0% +what I want you to notice in that yellow +little yellow portion in the gdp-bound + + align:start position:0% +little yellow portion in the gdp-bound + + + align:start position:0% +little yellow portion in the gdp-bound +form you actually don't really see where + + align:start position:0% +form you actually don't really see where + + + align:start position:0% +form you actually don't really see where +the rest of the protein is this is + + align:start position:0% +the rest of the protein is this is + + + align:start position:0% +the rest of the protein is this is +because this is a crystal structure and + + align:start position:0% +because this is a crystal structure and + + + align:start position:0% +because this is a crystal structure and +in the crystal structure when things are + + align:start position:0% +in the crystal structure when things are + + + align:start position:0% +in the crystal structure when things are +very mobile you can't even see electron + + align:start position:0% +very mobile you can't even see electron + + + align:start position:0% +very mobile you can't even see electron +density it's as if the part of the + + align:start position:0% +density it's as if the part of the + + + align:start position:0% +density it's as if the part of the +protein isn't + + align:start position:0% +protein isn't + + + align:start position:0% +protein isn't +there because it is so dynamic it's only + + align:start position:0% +there because it is so dynamic it's only + + + align:start position:0% +there because it is so dynamic it's only +in the gtp-bound form it forms this + + align:start position:0% +in the gtp-bound form it forms this + + + align:start position:0% +in the gtp-bound form it forms this +tight compact structure that represents + + align:start position:0% +tight compact structure that represents + + + align:start position:0% +tight compact structure that represents +an on a switch that has been turned on + + align:start position:0% +an on a switch that has been turned on + + + align:start position:0% +an on a switch that has been turned on +does that make sense to everybody is + + align:start position:0% +does that make sense to everybody is + + + align:start position:0% +does that make sense to everybody is +everyone good with that so just that + + align:start position:0% +everyone good with that so just that + + + align:start position:0% +everyone good with that so just that +change that extra phosphate reaching + + align:start position:0% +change that extra phosphate reaching + + + align:start position:0% +change that extra phosphate reaching +further to the protein and making an + + align:start position:0% +further to the protein and making an + + + align:start position:0% +further to the protein and making an +interaction with the protein itself + + align:start position:0% +interaction with the protein itself + + + align:start position:0% +interaction with the protein itself +makes the difference in the dynamics of + + align:start position:0% +makes the difference in the dynamics of + + + align:start position:0% +makes the difference in the dynamics of +the g-protein and the activity here now + + align:start position:0% +the g-protein and the activity here now + + + align:start position:0% +the g-protein and the activity here now +there are different types of G proteins + + align:start position:0% +there are different types of G proteins + + + align:start position:0% +there are different types of G proteins +and you'll see both types reflected in + + align:start position:0% +and you'll see both types reflected in + + + align:start position:0% +and you'll see both types reflected in +this lecture there are small G proteins + + align:start position:0% +this lecture there are small G proteins + + + align:start position:0% +this lecture there are small G proteins +and they are monomeric and then there + + align:start position:0% +and they are monomeric and then there + + + align:start position:0% +and they are monomeric and then there +are slightly more complicated G proteins + + align:start position:0% +are slightly more complicated G proteins + + + align:start position:0% +are slightly more complicated G proteins +that are trimeric they have a hetero + + align:start position:0% +that are trimeric they have a hetero + + + align:start position:0% +that are trimeric they have a hetero +trimeric structure so they have + + align:start position:0% +trimeric structure so they have + + + align:start position:0% +trimeric structure so they have +quaternary structure where you have + + align:start position:0% +quaternary structure where you have + + + align:start position:0% +quaternary structure where you have +three different proteins as part of the + + align:start position:0% +three different proteins as part of the + + + align:start position:0% +three different proteins as part of the +complex so the other ones are trimeric + + align:start position:0% + + + + align:start position:0% + +and it's the G protein actually + + align:start position:0% +and it's the G protein actually + + + align:start position:0% +and it's the G protein actually +comprises three subunits where one of + + align:start position:0% +comprises three subunits where one of + + + align:start position:0% +comprises three subunits where one of +them is the important one that binds GDP + + align:start position:0% +them is the important one that binds GDP + + + align:start position:0% +them is the important one that binds GDP +or gtp but they're a little bit more + + align:start position:0% +or gtp but they're a little bit more + + + align:start position:0% +or gtp but they're a little bit more +complicated and in the first example + + align:start position:0% +complicated and in the first example + + + align:start position:0% +complicated and in the first example +when I talk about a particular response + + align:start position:0% +when I talk about a particular response + + + align:start position:0% +when I talk about a particular response +to adrenaline we're going to see the + + align:start position:0% +to adrenaline we're going to see the + + + align:start position:0% +to adrenaline we're going to see the +trimeric g-proteins and because they're + + align:start position:0% +trimeric g-proteins and because they're + + + align:start position:0% +trimeric g-proteins and because they're +trimeric that means there's three + + align:start position:0% +trimeric that means there's three + + + align:start position:0% +trimeric that means there's three +subunits and the convention is that they + + align:start position:0% +subunits and the convention is that they + + + align:start position:0% +subunits and the convention is that they +get the Greek lettering system so they + + align:start position:0% +get the Greek lettering system so they + + + align:start position:0% +get the Greek lettering system so they +are the alpha beta and gamma subunits + + align:start position:0% +are the alpha beta and gamma subunits + + + align:start position:0% +are the alpha beta and gamma subunits +they've each got their name they're + + align:start position:0% +they've each got their name they're + + + align:start position:0% +they've each got their name they're +three independent polypeptide chains and + + align:start position:0% +three independent polypeptide chains and + + + align:start position:0% +three independent polypeptide chains and +is actually the alpha subunit the binds + + align:start position:0% +is actually the alpha subunit the binds + + + align:start position:0% +is actually the alpha subunit the binds +GDP or gtp so that's one the formulation + + align:start position:0% +GDP or gtp so that's one the formulation + + + align:start position:0% +GDP or gtp so that's one the formulation +of one of the types of switches that + + align:start position:0% +of one of the types of switches that + + + align:start position:0% +of one of the types of switches that +we're gonna see when we start to look at + + align:start position:0% +we're gonna see when we start to look at + + + align:start position:0% +we're gonna see when we start to look at +a pathway what you need to remember here + + align:start position:0% +a pathway what you need to remember here + + + align:start position:0% +a pathway what you need to remember here +you need to focus on the fact + + align:start position:0% +you need to focus on the fact + + + align:start position:0% +you need to focus on the fact +that in one state the protein is in an + + align:start position:0% +that in one state the protein is in an + + + align:start position:0% +that in one state the protein is in an +off state it doesn't kick off a + + align:start position:0% +off state it doesn't kick off a + + + align:start position:0% +off state it doesn't kick off a +signaling pathway but in the other state + + align:start position:0% + + + + align:start position:0% + +the protein is a different shape because + + align:start position:0% +the protein is a different shape because + + + align:start position:0% +the protein is a different shape because +of binding a link let's just make this a + + align:start position:0% +of binding a link let's just make this a + + + align:start position:0% +of binding a link let's just make this a +little longer to that closed faith + + align:start position:0% +little longer to that closed faith + + + align:start position:0% +little longer to that closed faith +that's negatively charged to the protein + + align:start position:0% +that's negatively charged to the protein + + + align:start position:0% +that's negatively charged to the protein +so that's a non state and they're very + + align:start position:0% +so that's a non state and they're very + + + align:start position:0% +so that's a non state and they're very +definitive types of structures now both + + align:start position:0% +definitive types of structures now both + + + align:start position:0% +definitive types of structures now both +of these proteins are intracellular + + align:start position:0% + + + + align:start position:0% + +which means they're part of the response + + align:start position:0% +which means they're part of the response + + + align:start position:0% +which means they're part of the response +once a signal reaches a cell they're the + + align:start position:0% +once a signal reaches a cell they're the + + + align:start position:0% +once a signal reaches a cell they're the +things that change and they're what the + + align:start position:0% +things that change and they're what the + + + align:start position:0% +things that change and they're what the +the signal that gets transduced + + align:start position:0% +the signal that gets transduced + + + align:start position:0% +the signal that gets transduced +to the g proteins now there's another + + align:start position:0% +to the g proteins now there's another + + + align:start position:0% +to the g proteins now there's another +type of intracellular switch which is + + align:start position:0% +type of intracellular switch which is + + + align:start position:0% +type of intracellular switch which is +used very very frequently in nature and + + align:start position:0% +used very very frequently in nature and + + + align:start position:0% +used very very frequently in nature and +in fact it crosses permeates through all + + align:start position:0% +in fact it crosses permeates through all + + + align:start position:0% +in fact it crosses permeates through all +kinds of cellular processes and these is + + align:start position:0% +kinds of cellular processes and these is + + + align:start position:0% +kinds of cellular processes and these is +phosphorylation so here are the G + + align:start position:0% +phosphorylation so here are the G + + + align:start position:0% +phosphorylation so here are the G +proteins which is one and the other one + + align:start position:0% +proteins which is one and the other one + + + align:start position:0% +proteins which is one and the other one +is phosphorylation okay now remember we + + align:start position:0% +is phosphorylation okay now remember we + + + align:start position:0% +is phosphorylation okay now remember we +talked about reactions of proteins that + + align:start position:0% +talked about reactions of proteins that + + + align:start position:0% +talked about reactions of proteins that +alter their behavior their properties + + align:start position:0% +alter their behavior their properties + + + align:start position:0% +alter their behavior their properties +their dynamics so protein + + align:start position:0% +their dynamics so protein + + + align:start position:0% +their dynamics so protein +phosphorylation remember is a post + + align:start position:0% +phosphorylation remember is a post + + + align:start position:0% +phosphorylation remember is a post +translational modification a PTM it's + + align:start position:0% +translational modification a PTM it's + + + align:start position:0% +translational modification a PTM it's +something that happens to a protein + + align:start position:0% +something that happens to a protein + + + align:start position:0% +something that happens to a protein +after it has been translated and folded + + align:start position:0% +after it has been translated and folded + + + align:start position:0% +after it has been translated and folded +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and the PTMs that a phosphorylation are + + align:start position:0% +and the PTMs that a phosphorylation are + + + align:start position:0% +and the PTMs that a phosphorylation are +involved OUP's amino acids that have OAH + + align:start position:0% +involved OUP's amino acids that have OAH + + + align:start position:0% +involved OUP's amino acids that have OAH +groups so that's the structure of + + align:start position:0% +groups so that's the structure of + + + align:start position:0% +groups so that's the structure of +tyrosine where the squiggles represent + + align:start position:0% +tyrosine where the squiggles represent + + + align:start position:0% +tyrosine where the squiggles represent +the rest of the protein + + align:start position:0% + + + + align:start position:0% + +and on phosphorylation we append a + + align:start position:0% +and on phosphorylation we append a + + + align:start position:0% +and on phosphorylation we append a +phosphate group oops - - to the oxygen + + align:start position:0% +phosphate group oops - - to the oxygen + + + align:start position:0% +phosphate group oops - - to the oxygen +on tyrosine on the sidechain so actually + + align:start position:0% +on tyrosine on the sidechain so actually + + + align:start position:0% +on tyrosine on the sidechain so actually +it looks pretty different it behaves + + align:start position:0% +it looks pretty different it behaves + + + align:start position:0% +it looks pretty different it behaves +pretty differently there are two other + + align:start position:0% +pretty differently there are two other + + + align:start position:0% +pretty differently there are two other +residues in eukaryotic cells that are + + align:start position:0% +residues in eukaryotic cells that are + + + align:start position:0% +residues in eukaryotic cells that are +commonly phosphorylated there the other + + align:start position:0% +commonly phosphorylated there the other + + + align:start position:0% +commonly phosphorylated there the other +two that include Oh H groups so they are + + align:start position:0% + + + + align:start position:0% + +serine and the third one to space but + + align:start position:0% +serine and the third one to space but + + + align:start position:0% +serine and the third one to space but +you get the general message and + + align:start position:0% +you get the general message and + + + align:start position:0% +you get the general message and +threonine so these are the three amino + + align:start position:0% +threonine so these are the three amino + + + align:start position:0% +threonine so these are the three amino +acids that commonly get a phosphate + + align:start position:0% +acids that commonly get a phosphate + + + align:start position:0% +acids that commonly get a phosphate +group attached and they change their + + align:start position:0% +group attached and they change their + + + align:start position:0% +group attached and they change their +properties they are called kinase kinase + + align:start position:0% +properties they are called kinase kinase + + + align:start position:0% +properties they are called kinase kinase +the root of the word is actually to + + align:start position:0% +the root of the word is actually to + + + align:start position:0% +the root of the word is actually to +change so the enzymes that catalyze this + + align:start position:0% +change so the enzymes that catalyze this + + + align:start position:0% +change so the enzymes that catalyze this +change are known as kinase a--'s and in + + align:start position:0% +change are known as kinase a--'s and in + + + align:start position:0% +change are known as kinase a--'s and in +contrast to the G proteins that use gtp + + align:start position:0% +contrast to the G proteins that use gtp + + + align:start position:0% +contrast to the G proteins that use gtp +the kinase is most commonly use ATP to + + align:start position:0% +the kinase is most commonly use ATP to + + + align:start position:0% +the kinase is most commonly use ATP to +give up a phosphate to phosphorylate the + + align:start position:0% +give up a phosphate to phosphorylate the + + + align:start position:0% +give up a phosphate to phosphorylate the +protein so there's another substrate in + + align:start position:0% +protein so there's another substrate in + + + align:start position:0% +protein so there's another substrate in +this reaction is ATP now when we look at + + align:start position:0% +this reaction is ATP now when we look at + + + align:start position:0% +this reaction is ATP now when we look at +this structure there's two or three + + align:start position:0% +this structure there's two or three + + + align:start position:0% +this structure there's two or three +things I really want to call your + + align:start position:0% +things I really want to call your + + + align:start position:0% +things I really want to call your +attention to once if we're dealing with + + align:start position:0% +attention to once if we're dealing with + + + align:start position:0% +attention to once if we're dealing with +this kind of switch we can go back to + + align:start position:0% +this kind of switch we can go back to + + + align:start position:0% +this kind of switch we can go back to +the off state by chopping up the gtp and + + align:start position:0% +the off state by chopping up the gtp and + + + align:start position:0% +the off state by chopping up the gtp and +making it GDP again so that's how to + + align:start position:0% +making it GDP again so that's how to + + + align:start position:0% +making it GDP again so that's how to +turn the light back off in the case of + + align:start position:0% +turn the light back off in the case of + + + align:start position:0% +turn the light back off in the case of +the kinase 'iz we've got to do something + + align:start position:0% +the kinase 'iz we've got to do something + + + align:start position:0% +the kinase 'iz we've got to do something +to go back from this state to the non + + align:start position:0% +to go back from this state to the non + + + align:start position:0% +to go back from this state to the non +modified state to turn the light switch + + align:start position:0% +modified state to turn the light switch + + + align:start position:0% +modified state to turn the light switch +off so for every transformation in the + + align:start position:0% +off so for every transformation in the + + + align:start position:0% +off so for every transformation in the +cell that involves a kinase there is a + + align:start position:0% +cell that involves a kinase there is a + + + align:start position:0% +cell that involves a kinase there is a +correspond + + align:start position:0% +correspond + + + align:start position:0% +correspond +reading set of enzymes that reverse the + + align:start position:0% +reading set of enzymes that reverse the + + + align:start position:0% +reading set of enzymes that reverse the +reaction called a phosphatase it takes + + align:start position:0% +reaction called a phosphatase it takes + + + align:start position:0% +reaction called a phosphatase it takes +that group off again so let me write + + align:start position:0% +that group off again so let me write + + + align:start position:0% +that group off again so let me write +that down here now phosphates used a lot + + align:start position:0% +that down here now phosphates used a lot + + + align:start position:0% +that down here now phosphates used a lot +so this is a possible protein + + align:start position:0% +so this is a possible protein + + + align:start position:0% +so this is a possible protein +phosphatase so kinase puts the phosphate + + align:start position:0% +phosphatase so kinase puts the phosphate + + + align:start position:0% +phosphatase so kinase puts the phosphate +on the phosphoryl protein phosphatase + + align:start position:0% +on the phosphoryl protein phosphatase + + + align:start position:0% +on the phosphoryl protein phosphatase +takes the phosphate off there are three + + align:start position:0% +takes the phosphate off there are three + + + align:start position:0% +takes the phosphate off there are three +types of amino acids that get most + + align:start position:0% +types of amino acids that get most + + + align:start position:0% +types of amino acids that get most +commonly modified in our cells tyrosine + + align:start position:0% +commonly modified in our cells tyrosine + + + align:start position:0% +commonly modified in our cells tyrosine +serine and threonine and one of the ones + + align:start position:0% +serine and threonine and one of the ones + + + align:start position:0% +serine and threonine and one of the ones +that forms an important part of an + + align:start position:0% +that forms an important part of an + + + align:start position:0% +that forms an important part of an +extracellular signaling mechanism are + + align:start position:0% +extracellular signaling mechanism are + + + align:start position:0% +extracellular signaling mechanism are +the tyrosine kinases and we'll delve + + align:start position:0% +the tyrosine kinases and we'll delve + + + align:start position:0% +the tyrosine kinases and we'll delve +into them in a little bit in the next + + align:start position:0% +into them in a little bit in the next + + + align:start position:0% +into them in a little bit in the next +second or but not the section I'm going + + align:start position:0% +second or but not the section I'm going + + + align:start position:0% +second or but not the section I'm going +to cover now but later because tyrosine + + align:start position:0% +to cover now but later because tyrosine + + + align:start position:0% +to cover now but later because tyrosine +various kinases come in a lot of + + align:start position:0% +various kinases come in a lot of + + + align:start position:0% +various kinases come in a lot of +different flavors the common flavors of + + align:start position:0% +different flavors the common flavors of + + + align:start position:0% +different flavors the common flavors of +whether you modify tyrosine or threonine + + align:start position:0% +whether you modify tyrosine or threonine + + + align:start position:0% +whether you modify tyrosine or threonine +serine because these are more similar to + + align:start position:0% +serine because these are more similar to + + + align:start position:0% +serine because these are more similar to +each other and this guy's different but + + align:start position:0% +each other and this guy's different but + + + align:start position:0% +each other and this guy's different but +we'll get to that later so in the cell + + align:start position:0% +we'll get to that later so in the cell + + + align:start position:0% +we'll get to that later so in the cell +we have about thirty twenty thousand + + align:start position:0% +we have about thirty twenty thousand + + + align:start position:0% +we have about thirty twenty thousand +genes that encode proteins including + + align:start position:0% +genes that encode proteins including + + + align:start position:0% +genes that encode proteins including +genes alright five hundred and fifteen + + align:start position:0% +genes alright five hundred and fifteen + + + align:start position:0% +genes alright five hundred and fifteen +of those are kindnesses that's a pretty + + align:start position:0% +of those are kindnesses that's a pretty + + + align:start position:0% +of those are kindnesses that's a pretty +big chunk of the genome you got to + + align:start position:0% +big chunk of the genome you got to + + + align:start position:0% +big chunk of the genome you got to +accept so in excess of 500 our kinase is + + align:start position:0% +accept so in excess of 500 our kinase is + + + align:start position:0% +accept so in excess of 500 our kinase is +specifically protein kinase is the ones + + align:start position:0% +specifically protein kinase is the ones + + + align:start position:0% +specifically protein kinase is the ones +that modify so there's a big chunk of + + align:start position:0% +that modify so there's a big chunk of + + + align:start position:0% +that modify so there's a big chunk of +the genome dedicated for this kind of + + align:start position:0% +the genome dedicated for this kind of + + + align:start position:0% +the genome dedicated for this kind of +activity and these dynamic because + + align:start position:0% +activity and these dynamic because + + + align:start position:0% +activity and these dynamic because +there's also about a hundred + + align:start position:0% +there's also about a hundred + + + align:start position:0% +there's also about a hundred +phosphatases they're a little bit more + + align:start position:0% +phosphatases they're a little bit more + + + align:start position:0% +phosphatases they're a little bit more +promiscuous you don't need so many of + + align:start position:0% +promiscuous you don't need so many of + + + align:start position:0% +promiscuous you don't need so many of +them but a large sort of component of + + align:start position:0% +them but a large sort of component of + + + align:start position:0% +them but a large sort of component of +the genome is responsible for + + align:start position:0% +the genome is responsible for + + + align:start position:0% +the genome is responsible for +phosphorylating proteins and d + + align:start position:0% +phosphorylating proteins and d + + + align:start position:0% +phosphorylating proteins and d +phosphorylating phospho proteins and + + align:start position:0% +phosphorylating phospho proteins and + + + align:start position:0% +phosphorylating phospho proteins and +that part of the genome + + align:start position:0% +that part of the genome + + + align:start position:0% +that part of the genome +it's own special name let's see I don't + + align:start position:0% +it's own special name let's see I don't + + + align:start position:0% +it's own special name let's see I don't +know and it is called Buckeye gnome I + + align:start position:0% +know and it is called Buckeye gnome I + + + align:start position:0% +know and it is called Buckeye gnome I +hope that's not too small in there so if + + align:start position:0% +hope that's not too small in there so if + + + align:start position:0% +hope that's not too small in there so if +we're describing all the enzymes in the + + align:start position:0% +we're describing all the enzymes in the + + + align:start position:0% +we're describing all the enzymes in the +genome that catalyze phosphorylation we + + align:start position:0% +genome that catalyze phosphorylation we + + + align:start position:0% +genome that catalyze phosphorylation we +would call it the kinase a collective + + align:start position:0% +would call it the kinase a collective + + + align:start position:0% +would call it the kinase a collective +set because it's the set of kinases and + + align:start position:0% +set because it's the set of kinases and + + + align:start position:0% +set because it's the set of kinases and +you'll hear that term quite quite + + align:start position:0% +you'll hear that term quite quite + + + align:start position:0% +you'll hear that term quite quite +commonly and the Tri no Ms really + + align:start position:0% +commonly and the Tri no Ms really + + + align:start position:0% +commonly and the Tri no Ms really +important and represents major major + + align:start position:0% +important and represents major major + + + align:start position:0% +important and represents major major +therapeutic targets because it's when + + align:start position:0% +therapeutic targets because it's when + + + align:start position:0% +therapeutic targets because it's when +kinase is go wrong that we have + + align:start position:0% +kinase is go wrong that we have + + + align:start position:0% +kinase is go wrong that we have +physiological defects so let's just go + + align:start position:0% +physiological defects so let's just go + + + align:start position:0% +physiological defects so let's just go +back to this you can see we've got the + + align:start position:0% +back to this you can see we've got the + + + align:start position:0% +back to this you can see we've got the +kinase and the phosphatase the donor for + + align:start position:0% +kinase and the phosphatase the donor for + + + align:start position:0% +kinase and the phosphatase the donor for +phosphorylation is ATP and it is the + + align:start position:0% +phosphorylation is ATP and it is the + + + align:start position:0% +phosphorylation is ATP and it is the +gamma phosphate that's transferred to + + align:start position:0% +gamma phosphate that's transferred to + + + align:start position:0% +gamma phosphate that's transferred to +the protein to switch it from the off + + align:start position:0% +the protein to switch it from the off + + + align:start position:0% +the protein to switch it from the off +state to the on state it is a post + + align:start position:0% +state to the on state it is a post + + + align:start position:0% +state to the on state it is a post +translational modification meaning it + + align:start position:0% +translational modification meaning it + + + align:start position:0% +translational modification meaning it +occurs on a protein after the protein + + align:start position:0% +occurs on a protein after the protein + + + align:start position:0% +occurs on a protein after the protein +has been fully translated there are a + + align:start position:0% +has been fully translated there are a + + + align:start position:0% +has been fully translated there are a +few Co translational PTMs + + align:start position:0% +few Co translational PTMs + + + align:start position:0% +few Co translational PTMs +that seems like a bit of a an oxymoron + + align:start position:0% +that seems like a bit of a an oxymoron + + + align:start position:0% +that seems like a bit of a an oxymoron +Co translational modifications but of + + align:start position:0% +Co translational modifications but of + + + align:start position:0% +Co translational modifications but of +phosphorylation ISM one of them + + align:start position:0% +phosphorylation ISM one of them + + + align:start position:0% +phosphorylation ISM one of them +glycosylation is and we won't go into + + align:start position:0% +glycosylation is and we won't go into + + + align:start position:0% +glycosylation is and we won't go into +those in any detail even though it + + align:start position:0% +those in any detail even though it + + + align:start position:0% +those in any detail even though it +breaks my heart not to go into those but + + align:start position:0% +breaks my heart not to go into those but + + + align:start position:0% +breaks my heart not to go into those but +ok alright so now I want to first of all + + align:start position:0% +ok alright so now I want to first of all + + + align:start position:0% +ok alright so now I want to first of all +introduce you to a paradigm for + + align:start position:0% +introduce you to a paradigm for + + + align:start position:0% +introduce you to a paradigm for +signaling as opposed to really go into + + align:start position:0% +signaling as opposed to really go into + + + align:start position:0% +signaling as opposed to really go into +what's happening and so one of the first + + align:start position:0% +what's happening and so one of the first + + + align:start position:0% +what's happening and so one of the first +paradigms is a situation where you have + + align:start position:0% +paradigms is a situation where you have + + + align:start position:0% +paradigms is a situation where you have +a cell in the plasma membrane of that + + align:start position:0% +a cell in the plasma membrane of that + + + align:start position:0% +a cell in the plasma membrane of that +cell is a receptor and it gets hit with + + align:start position:0% +cell is a receptor and it gets hit with + + + align:start position:0% +cell is a receptor and it gets hit with +a signal so a signaling paradigm is that + + align:start position:0% +a signal so a signaling paradigm is that + + + align:start position:0% +a signal so a signaling paradigm is that +a molecule from outside the cell binds + + align:start position:0% +a molecule from outside the cell binds + + + align:start position:0% +a molecule from outside the cell binds +to something that's transmembrane and + + align:start position:0% +to something that's transmembrane and + + + align:start position:0% +to something that's transmembrane and +then you start getting signal + + align:start position:0% +then you start getting signal + + + align:start position:0% +then you start getting signal +transduction through a pathway so any + + align:start position:0% +transduction through a pathway so any + + + align:start position:0% +transduction through a pathway so any +extracellular signal could be could be + + align:start position:0% +extracellular signal could be could be + + + align:start position:0% +extracellular signal could be could be +game in this process and then there's a + + align:start position:0% +game in this process and then there's a + + + align:start position:0% +game in this process and then there's a +sequence events upon signal binding + + align:start position:0% +sequence events upon signal binding + + + align:start position:0% +sequence events upon signal binding +there's a sequence of changes that ends + + align:start position:0% +there's a sequence of changes that ends + + + align:start position:0% +there's a sequence of changes that ends +you up with a final output and generally + + align:start position:0% +you up with a final output and generally + + + align:start position:0% +you up with a final output and generally +signaling pathways go through a number + + align:start position:0% +signaling pathways go through a number + + + align:start position:0% +signaling pathways go through a number +of steps where is there is + + align:start position:0% +of steps where is there is + + + align:start position:0% +of steps where is there is +the opportunity for the amplification of + + align:start position:0% +the opportunity for the amplification of + + + align:start position:0% +the opportunity for the amplification of +a signal so I talked to you last about + + align:start position:0% +a signal so I talked to you last about + + + align:start position:0% +a signal so I talked to you last about +time about some of the hallmarks of + + align:start position:0% +time about some of the hallmarks of + + + align:start position:0% +time about some of the hallmarks of +signalling specificity defines how how + + align:start position:0% +signalling specificity defines how how + + + align:start position:0% +signalling specificity defines how how +accurately that extracellular signal + + align:start position:0% +accurately that extracellular signal + + + align:start position:0% +accurately that extracellular signal +binds to the receptor but amplification + + align:start position:0% +binds to the receptor but amplification + + + align:start position:0% +binds to the receptor but amplification +really refers to how signals get bigger + + align:start position:0% +really refers to how signals get bigger + + + align:start position:0% +really refers to how signals get bigger +and bigger through certain steps in a + + align:start position:0% +and bigger through certain steps in a + + + align:start position:0% +and bigger through certain steps in a +signalling pathway in order to have a + + align:start position:0% +signalling pathway in order to have a + + + align:start position:0% +signalling pathway in order to have a +big impact in the cell not just a single + + align:start position:0% +big impact in the cell not just a single + + + align:start position:0% +big impact in the cell not just a single +event going through a single pathway one + + align:start position:0% +event going through a single pathway one + + + align:start position:0% +event going through a single pathway one +molecule at a time and we'll see that in + + align:start position:0% +molecule at a time and we'll see that in + + + align:start position:0% +molecule at a time and we'll see that in +the example that I show you okay then + + align:start position:0% +the example that I show you okay then + + + align:start position:0% +the example that I show you okay then +oftentimes when we look at signaling + + align:start position:0% +oftentimes when we look at signaling + + + align:start position:0% +oftentimes when we look at signaling +pathways we care a great deal about + + align:start position:0% +pathways we care a great deal about + + + align:start position:0% +pathways we care a great deal about +what's the first response upon the + + align:start position:0% +what's the first response upon the + + + align:start position:0% +what's the first response upon the +signal hitting the outside of the cell + + align:start position:0% +signal hitting the outside of the cell + + + align:start position:0% +signal hitting the outside of the cell +so in many signaling pathways this could + + align:start position:0% +so in many signaling pathways this could + + + align:start position:0% +so in many signaling pathways this could +be a protein the receptor could be a + + align:start position:0% +be a protein the receptor could be a + + + align:start position:0% +be a protein the receptor could be a +protein that is bound to a g-protein and + + align:start position:0% +protein that is bound to a g-protein and + + + align:start position:0% +protein that is bound to a g-protein and +that would be the first responder + + align:start position:0% +that would be the first responder + + + align:start position:0% +that would be the first responder +through the pathway that really triggers + + align:start position:0% +through the pathway that really triggers + + + align:start position:0% +through the pathway that really triggers +off the cellular events okay and now so + + align:start position:0% +off the cellular events okay and now so + + + align:start position:0% +off the cellular events okay and now so +what I want to talk about now is the the + + align:start position:0% +what I want to talk about now is the the + + + align:start position:0% +what I want to talk about now is the the +I always get this wrong I always thought + + align:start position:0% +I always get this wrong I always thought + + + align:start position:0% +I always get this wrong I always thought +it was flight or fight or fight or + + align:start position:0% +it was flight or fight or fight or + + + align:start position:0% +it was flight or fight or fight or +whatever right I always thought it was + + align:start position:0% +whatever right I always thought it was + + + align:start position:0% +whatever right I always thought it was +flight or fright but it's not the the + + align:start position:0% +flight or fright but it's not the the + + + align:start position:0% +flight or fright but it's not the the +response is actually the fight-or-flight + + align:start position:0% +response is actually the fight-or-flight + + + align:start position:0% +response is actually the fight-or-flight +so let's set this up to understand why + + align:start position:0% +so let's set this up to understand why + + + align:start position:0% +so let's set this up to understand why +this is such a great manifestation of a + + align:start position:0% +this is such a great manifestation of a + + + align:start position:0% +this is such a great manifestation of a +cellular signaling response because it + + align:start position:0% +cellular signaling response because it + + + align:start position:0% +cellular signaling response because it +includes a lot of the hallmarks that are + + align:start position:0% +includes a lot of the hallmarks that are + + + align:start position:0% +includes a lot of the hallmarks that are +really characteristic of the cellular + + align:start position:0% +really characteristic of the cellular + + + align:start position:0% +really characteristic of the cellular +response so this response involves a + + align:start position:0% + + + + align:start position:0% + +cellular receptor that is called a + + align:start position:0% +cellular receptor that is called a + + + align:start position:0% +cellular receptor that is called a +g-protein coupled + + align:start position:0% + + + + align:start position:0% + +receptor we saw a little bit about them + + align:start position:0% +receptor we saw a little bit about them + + + align:start position:0% +receptor we saw a little bit about them +last time they are always called GP CRS + + align:start position:0% +last time they are always called GP CRS + + + align:start position:0% +last time they are always called GP CRS +for short and what that term means is + + align:start position:0% +for short and what that term means is + + + align:start position:0% +for short and what that term means is +that it's a receptor that's linked in + + align:start position:0% +that it's a receptor that's linked in + + + align:start position:0% +that it's a receptor that's linked in +some way to a g-protein so it could be + + align:start position:0% +some way to a g-protein so it could be + + + align:start position:0% +some way to a g-protein so it could be +coupled to a monomeric or a trimeric + + align:start position:0% + + + + align:start position:0% + +g-protein so don't confuse the two one + + align:start position:0% +g-protein so don't confuse the two one + + + align:start position:0% +g-protein so don't confuse the two one +is the receptor it's transmembrane it's + + align:start position:0% +is the receptor it's transmembrane it's + + + align:start position:0% +is the receptor it's transmembrane it's +responsible for transducing receiving + + align:start position:0% +responsible for transducing receiving + + + align:start position:0% +responsible for transducing receiving +signals and transducing them the first + + align:start position:0% +signals and transducing them the first + + + align:start position:0% +signals and transducing them the first +responder is the g-protein that changes + + align:start position:0% +responder is the g-protein that changes + + + align:start position:0% +responder is the g-protein that changes +from a gdp-bound state to a gtp bound + + align:start position:0% +from a gdp-bound state to a gtp bound + + + align:start position:0% +from a gdp-bound state to a gtp bound +state and in the one that we're going to + + align:start position:0% +state and in the one that we're going to + + + align:start position:0% +state and in the one that we're going to +talk about we're going to deal with a + + align:start position:0% +talk about we're going to deal with a + + + align:start position:0% +talk about we're going to deal with a +trimeric g-protein in the fight or + + align:start position:0% +trimeric g-protein in the fight or + + + align:start position:0% +trimeric g-protein in the fight or +flight response and what you see here is + + align:start position:0% +flight response and what you see here is + + + align:start position:0% +flight response and what you see here is +a cartoon of the players that are + + align:start position:0% +a cartoon of the players that are + + + align:start position:0% +a cartoon of the players that are +involved so remember the G proteins we + + align:start position:0% +involved so remember the G proteins we + + + align:start position:0% +involved so remember the G proteins we +talked about them briefly last time they + + align:start position:0% +talked about them briefly last time they + + + align:start position:0% +talked about them briefly last time they +have seven transmembrane helix C's they + + align:start position:0% +have seven transmembrane helix C's they + + + align:start position:0% +have seven transmembrane helix C's they +span the membrane they have the + + align:start position:0% +span the membrane they have the + + + align:start position:0% +span the membrane they have the +n-terminal outside whoops one two three + + align:start position:0% +n-terminal outside whoops one two three + + + align:start position:0% +n-terminal outside whoops one two three +four five six seven and terminus out C + + align:start position:0% +four five six seven and terminus out C + + + align:start position:0% +four five six seven and terminus out C +terminus in and each of these is a + + align:start position:0% +terminus in and each of these is a + + + align:start position:0% +terminus in and each of these is a +transmembrane helix and this would be + + align:start position:0% +transmembrane helix and this would be + + + align:start position:0% +transmembrane helix and this would be +outside the cell this would be in the + + align:start position:0% +outside the cell this would be in the + + + align:start position:0% +outside the cell this would be in the +cytoplasm okay and you can actually + + align:start position:0% +cytoplasm okay and you can actually + + + align:start position:0% +cytoplasm okay and you can actually +often look at a transmembrane protein + + align:start position:0% +often look at a transmembrane protein + + + align:start position:0% +often look at a transmembrane protein +and know its behavior because the width + + align:start position:0% +and know its behavior because the width + + + align:start position:0% +and know its behavior because the width +of these transmembrane helix e's often + + align:start position:0% +of these transmembrane helix e's often + + + align:start position:0% +of these transmembrane helix e's often +comes in at approximately forty angstrom + + align:start position:0% +comes in at approximately forty angstrom + + + align:start position:0% +comes in at approximately forty angstrom +which is the span of a membrane you can + + align:start position:0% +which is the span of a membrane you can + + + align:start position:0% +which is the span of a membrane you can +sort of say that looks like a + + align:start position:0% +sort of say that looks like a + + + align:start position:0% +sort of say that looks like a +transmembrane helix it's exactly that + + align:start position:0% +transmembrane helix it's exactly that + + + align:start position:0% +transmembrane helix it's exactly that +dimension to cross a membrane and the + + align:start position:0% +dimension to cross a membrane and the + + + align:start position:0% +dimension to cross a membrane and the +trans the + + align:start position:0% +trans the + + + align:start position:0% +trans the +GPCRs in this case would bind to a + + align:start position:0% +GPCRs in this case would bind to a + + + align:start position:0% +GPCRs in this case would bind to a +ligand outside the cell and have a + + align:start position:0% +ligand outside the cell and have a + + + align:start position:0% +ligand outside the cell and have a +response inside the cell so those seven + + align:start position:0% +response inside the cell so those seven + + + align:start position:0% +response inside the cell so those seven +transmembrane helix E's are responding + + align:start position:0% +transmembrane helix E's are responding + + + align:start position:0% +transmembrane helix E's are responding +to ligand binding so let's take a look + + align:start position:0% +to ligand binding so let's take a look + + + align:start position:0% +to ligand binding so let's take a look +at this picture because it's almost + + align:start position:0% +at this picture because it's almost + + + align:start position:0% +at this picture because it's almost +impossible for me to get it onto the + + align:start position:0% +impossible for me to get it onto the + + + align:start position:0% +impossible for me to get it onto the +screen so that the its binds to a + + align:start position:0% +screen so that the its binds to a + + + align:start position:0% +screen so that the its binds to a +trimeric g-protein remember I talked to + + align:start position:0% +trimeric g-protein remember I talked to + + + align:start position:0% +trimeric g-protein remember I talked to +you about the two different types the + + align:start position:0% +you about the two different types the + + + align:start position:0% +you about the two different types the +trimeric has an alpha beta and gamma + + align:start position:0% +trimeric has an alpha beta and gamma + + + align:start position:0% +trimeric has an alpha beta and gamma +subunit quaternary structure and they're + + align:start position:0% +subunit quaternary structure and they're + + + align:start position:0% +subunit quaternary structure and they're +shown here in different colors the green + + align:start position:0% +shown here in different colors the green + + + align:start position:0% +shown here in different colors the green +is the alpha subunit the magenta is the + + align:start position:0% +is the alpha subunit the magenta is the + + + align:start position:0% +is the alpha subunit the magenta is the +or the red is the gamma subunit and the + + align:start position:0% +or the red is the gamma subunit and the + + + align:start position:0% +or the red is the gamma subunit and the +yellow is the beta subunit so what + + align:start position:0% +yellow is the beta subunit so what + + + align:start position:0% +yellow is the beta subunit so what +happens when the ligand binds to the + + align:start position:0% +happens when the ligand binds to the + + + align:start position:0% +happens when the ligand binds to the +g-protein there is a reorganization of + + align:start position:0% +g-protein there is a reorganization of + + + align:start position:0% +g-protein there is a reorganization of +that G Pro excuse me when it binds to + + align:start position:0% +that G Pro excuse me when it binds to + + + align:start position:0% +that G Pro excuse me when it binds to +the G protein-coupled receptor there is + + align:start position:0% +the G protein-coupled receptor there is + + + align:start position:0% +the G protein-coupled receptor there is +a reorganization of those seven + + align:start position:0% +a reorganization of those seven + + + align:start position:0% +a reorganization of those seven +transmembrane helix E's last time I + + align:start position:0% +transmembrane helix E's last time I + + + align:start position:0% +transmembrane helix E's last time I +identified them to you when you look at + + align:start position:0% +identified them to you when you look at + + + align:start position:0% +identified them to you when you look at +a couple of these they're actually + + align:start position:0% +a couple of these they're actually + + + align:start position:0% +a couple of these they're actually +fairly large loops that grab onto your + + align:start position:0% +fairly large loops that grab onto your + + + align:start position:0% +fairly large loops that grab onto your +ligand and that will translate + + align:start position:0% +ligand and that will translate + + + align:start position:0% +ligand and that will translate +conformational information through the + + align:start position:0% +conformational information through the + + + align:start position:0% +conformational information through the +membrane to the other side where the G + + align:start position:0% +membrane to the other side where the G + + + align:start position:0% +membrane to the other side where the G +proteins are sitting and in this + + align:start position:0% +proteins are sitting and in this + + + align:start position:0% +proteins are sitting and in this +response what happens is upon binding + + align:start position:0% +response what happens is upon binding + + + align:start position:0% +response what happens is upon binding +the ligand the alpha subunit leaves the + + align:start position:0% +the ligand the alpha subunit leaves the + + + align:start position:0% +the ligand the alpha subunit leaves the +team and goes from there GDP GDP bound + + align:start position:0% +team and goes from there GDP GDP bound + + + align:start position:0% +team and goes from there GDP GDP bound +States to the GT bound State so it + + align:start position:0% +States to the GT bound State so it + + + align:start position:0% +States to the GT bound State so it +literally changes its state and changes + + align:start position:0% +literally changes its state and changes + + + align:start position:0% +literally changes its state and changes +its mode of Association within the cell + + align:start position:0% +its mode of Association within the cell + + + align:start position:0% +its mode of Association within the cell +upon that action so you can see how + + align:start position:0% +upon that action so you can see how + + + align:start position:0% +upon that action so you can see how +nicely we have transduced the ligand + + align:start position:0% +nicely we have transduced the ligand + + + align:start position:0% +nicely we have transduced the ligand +binding out here to a pretty discrete + + align:start position:0% +binding out here to a pretty discrete + + + align:start position:0% +binding out here to a pretty discrete +cellular event turning on the switch of + + align:start position:0% +cellular event turning on the switch of + + + align:start position:0% +cellular event turning on the switch of +the g-protein alpha subunit is everyone + + align:start position:0% +the g-protein alpha subunit is everyone + + + align:start position:0% +the g-protein alpha subunit is everyone +following me there I know it so it looks + + align:start position:0% +following me there I know it so it looks + + + align:start position:0% +following me there I know it so it looks +complicated to start with B or C it in + + align:start position:0% +complicated to start with B or C it in + + + align:start position:0% +complicated to start with B or C it in +in action okay so here are the cellular + + align:start position:0% +in action okay so here are the cellular + + + align:start position:0% +in action okay so here are the cellular +components of the of the response so + + align:start position:0% +components of the of the response so + + + align:start position:0% +components of the of the response so +basically this is the kind of response + + align:start position:0% +basically this is the kind of response + + + align:start position:0% +basically this is the kind of response +where if you get scared or you feel + + align:start position:0% +where if you get scared or you feel + + + align:start position:0% +where if you get scared or you feel +you're in harm's way you will trigger + + align:start position:0% +you're in harm's way you will trigger + + + align:start position:0% +you're in harm's way you will trigger +this response + + align:start position:0% +this response + + + align:start position:0% +this response +in order to generate a lot of a lot of + + align:start position:0% +in order to generate a lot of a lot of + + + align:start position:0% +in order to generate a lot of a lot of +ATP in order that you can respond run + + align:start position:0% +ATP in order that you can respond run + + + align:start position:0% +ATP in order that you can respond run +away high to do something very active in + + align:start position:0% +away high to do something very active in + + + align:start position:0% +away high to do something very active in +order to rapidly respond to a threat of + + align:start position:0% +order to rapidly respond to a threat of + + + align:start position:0% +order to rapidly respond to a threat of +some kind and this response is triggered + + align:start position:0% +some kind and this response is triggered + + + align:start position:0% +some kind and this response is triggered +by a small molecule in this case it's + + align:start position:0% +by a small molecule in this case it's + + + align:start position:0% +by a small molecule in this case it's +epinephrine or adrenaline different + + align:start position:0% +epinephrine or adrenaline different + + + align:start position:0% +epinephrine or adrenaline different +names on different sides of the Atlantic + + align:start position:0% +names on different sides of the Atlantic + + + align:start position:0% +names on different sides of the Atlantic +but you all know what adrenaline is and + + align:start position:0% +but you all know what adrenaline is and + + + align:start position:0% +but you all know what adrenaline is and +here's the structure of epinephrine or + + align:start position:0% +here's the structure of epinephrine or + + + align:start position:0% +here's the structure of epinephrine or +adrenaline and it is the signal for the + + align:start position:0% +adrenaline and it is the signal for the + + + align:start position:0% +adrenaline and it is the signal for the +flight off right the flight or fight + + align:start position:0% +flight off right the flight or fight + + + align:start position:0% +flight off right the flight or fight +response because it's the small molecule + + align:start position:0% +response because it's the small molecule + + + align:start position:0% +response because it's the small molecule +that binds to the extracellular surface + + align:start position:0% +that binds to the extracellular surface + + + align:start position:0% +that binds to the extracellular surface +of the receptor changes its shape so + + align:start position:0% +of the receptor changes its shape so + + + align:start position:0% +of the receptor changes its shape so +that things can happen intracellularly + + align:start position:0% +that things can happen intracellularly + + + align:start position:0% +that things can happen intracellularly +and it's just one small molecule + + align:start position:0% +and it's just one small molecule + + + align:start position:0% +and it's just one small molecule +normally that would be charged it + + align:start position:0% +normally that would be charged it + + + align:start position:0% +normally that would be charged it +doesn't diffuse across the membrane so + + align:start position:0% +doesn't diffuse across the membrane so + + + align:start position:0% +doesn't diffuse across the membrane so +it's stuck being on the outside of the + + align:start position:0% +it's stuck being on the outside of the + + + align:start position:0% +it's stuck being on the outside of the +membrane okay so this is the signal that + + align:start position:0% +membrane okay so this is the signal that + + + align:start position:0% +membrane okay so this is the signal that +triggers the response so if you have to + + align:start position:0% +triggers the response so if you have to + + + align:start position:0% +triggers the response so if you have to +respond to a threat of some kind + + align:start position:0% +respond to a threat of some kind + + + align:start position:0% +respond to a threat of some kind +you can't stop sort of go to the fridge + + align:start position:0% +you can't stop sort of go to the fridge + + + align:start position:0% +you can't stop sort of go to the fridge +get a big snack eat it + + align:start position:0% +get a big snack eat it + + + align:start position:0% +get a big snack eat it +you know digest all your food and hope + + align:start position:0% +you know digest all your food and hope + + + align:start position:0% +you know digest all your food and hope +you're going to get energy quickly what + + align:start position:0% +you're going to get energy quickly what + + + align:start position:0% +you're going to get energy quickly what +you've got to do is have a response + + align:start position:0% +you've got to do is have a response + + + align:start position:0% +you've got to do is have a response +where you can generate energy from your + + align:start position:0% +where you can generate energy from your + + + align:start position:0% +where you can generate energy from your +glycogen stores that are in the liver so + + align:start position:0% +glycogen stores that are in the liver so + + + align:start position:0% +glycogen stores that are in the liver so +there is a signal comes from the adrenal + + align:start position:0% +there is a signal comes from the adrenal + + + align:start position:0% +there is a signal comes from the adrenal +region which is the release of + + align:start position:0% +region which is the release of + + + align:start position:0% +region which is the release of +adrenaline that goes to the cell surface + + align:start position:0% +adrenaline that goes to the cell surface + + + align:start position:0% +adrenaline that goes to the cell surface +receptors to trigger the response and + + align:start position:0% +receptors to trigger the response and + + + align:start position:0% +receptors to trigger the response and +what kind of signal would this be would + + align:start position:0% +what kind of signal would this be would + + + align:start position:0% +what kind of signal would this be would +it be paracrine autocrine EXO crying + + align:start position:0% +it be paracrine autocrine EXO crying + + + align:start position:0% +it be paracrine autocrine EXO crying +what kind of signal would that be oh + + align:start position:0% +what kind of signal would that be oh + + + align:start position:0% +what kind of signal would that be oh +sorry endocrine para crying + + align:start position:0% +sorry endocrine para crying + + + align:start position:0% +sorry endocrine para crying +Chuckster crime do you remember last + + align:start position:0% +Chuckster crime do you remember last + + + align:start position:0% +Chuckster crime do you remember last +time yeah + + align:start position:0% +time yeah + + + align:start position:0% +time yeah +endocrine so it's a response that comes + + align:start position:0% +endocrine so it's a response that comes + + + align:start position:0% +endocrine so it's a response that comes +from the kidneys and goes to the liver + + align:start position:0% +from the kidneys and goes to the liver + + + align:start position:0% +from the kidneys and goes to the liver +so it's going it's traveling autocrine + + align:start position:0% +so it's going it's traveling autocrine + + + align:start position:0% +so it's going it's traveling autocrine +is self paracrine is near juxtacrine is + + align:start position:0% +is self paracrine is near juxtacrine is + + + align:start position:0% +is self paracrine is near juxtacrine is +cell contact but any of these hormonal + + align:start position:0% +cell contact but any of these hormonal + + + align:start position:0% +cell contact but any of these hormonal +responses are pretty commonly endocrine + + align:start position:0% +responses are pretty commonly endocrine + + + align:start position:0% +responses are pretty commonly endocrine +responses so what happens once the + + align:start position:0% +responses so what happens once the + + + align:start position:0% +responses so what happens once the +signal binds so the specificity in this + + align:start position:0% +signal binds so the specificity in this + + + align:start position:0% +signal binds so the specificity in this +situation is that the g-protein coupled + + align:start position:0% +situation is that the g-protein coupled + + + align:start position:0% +situation is that the g-protein coupled +with + + align:start position:0% +with + + + align:start position:0% +with +now shown in pink in very stylized form + + align:start position:0% +now shown in pink in very stylized form + + + align:start position:0% +now shown in pink in very stylized form +but you can count those seven + + align:start position:0% +but you can count those seven + + + align:start position:0% +but you can count those seven +transmembrane domains will bind + + align:start position:0% +transmembrane domains will bind + + + align:start position:0% +transmembrane domains will bind +exclusively to this GPCR with high + + align:start position:0% +exclusively to this GPCR with high + + + align:start position:0% +exclusively to this GPCR with high +specificity another signal another small + + align:start position:0% +specificity another signal another small + + + align:start position:0% +specificity another signal another small +molecule that looks like it won't bind + + align:start position:0% +molecule that looks like it won't bind + + + align:start position:0% +molecule that looks like it won't bind +because we have to have specificity for + + align:start position:0% +because we have to have specificity for + + + align:start position:0% +because we have to have specificity for +the signal upon that binding event it + + align:start position:0% +the signal upon that binding event it + + + align:start position:0% +the signal upon that binding event it +will trigger a change within the cell + + align:start position:0% +will trigger a change within the cell + + + align:start position:0% +will trigger a change within the cell +and that change within the cell is that + + align:start position:0% +and that change within the cell is that + + + align:start position:0% +and that change within the cell is that +the alpha subunit here you see alpha + + align:start position:0% +the alpha subunit here you see alpha + + + align:start position:0% +the alpha subunit here you see alpha +subunit beta gamma they're all shown in + + align:start position:0% +subunit beta gamma they're all shown in + + + align:start position:0% +subunit beta gamma they're all shown in +green the alpha subunit of the g-protein + + align:start position:0% +green the alpha subunit of the g-protein + + + align:start position:0% +green the alpha subunit of the g-protein +remember I told you it was a trimeric + + align:start position:0% +remember I told you it was a trimeric + + + align:start position:0% +remember I told you it was a trimeric +g-protein where the alpha subunit is the + + align:start position:0% +g-protein where the alpha subunit is the + + + align:start position:0% +g-protein where the alpha subunit is the +key player the alpha subunit leaves the + + align:start position:0% +key player the alpha subunit leaves the + + + align:start position:0% +key player the alpha subunit leaves the +team and it exchanges its G GDP that's + + align:start position:0% +team and it exchanges its G GDP that's + + + align:start position:0% +team and it exchanges its G GDP that's +its resting state nothing's happening + + align:start position:0% +its resting state nothing's happening + + + align:start position:0% +its resting state nothing's happening +for gtp which turns it on so that's the + + align:start position:0% +for gtp which turns it on so that's the + + + align:start position:0% +for gtp which turns it on so that's the +first response the g-protein is + + align:start position:0% +first response the g-protein is + + + align:start position:0% +first response the g-protein is +responding to the signal from the + + align:start position:0% +responding to the signal from the + + + align:start position:0% +responding to the signal from the +outside of the cell through the auspices + + align:start position:0% +outside of the cell through the auspices + + + align:start position:0% +outside of the cell through the auspices +of the g-protein coupled receptor to + + align:start position:0% +of the g-protein coupled receptor to + + + align:start position:0% +of the g-protein coupled receptor to +give a change within the cell that's a + + align:start position:0% +give a change within the cell that's a + + + align:start position:0% +give a change within the cell that's a +discrete change okay + + align:start position:0% +discrete change okay + + + align:start position:0% +discrete change okay +following me so far so now what we need + + align:start position:0% +following me so far so now what we need + + + align:start position:0% +following me so far so now what we need +to do is trigger the remaining + + align:start position:0% +to do is trigger the remaining + + + align:start position:0% +to do is trigger the remaining +biochemical events that are going to get + + align:start position:0% +biochemical events that are going to get + + + align:start position:0% +biochemical events that are going to get +us out of this sticky situation where we + + align:start position:0% +us out of this sticky situation where we + + + align:start position:0% +us out of this sticky situation where we +need to produce a lot of ATP so it turns + + align:start position:0% +need to produce a lot of ATP so it turns + + + align:start position:0% +need to produce a lot of ATP so it turns +out that the gtp-bound form of the alpha + + align:start position:0% +out that the gtp-bound form of the alpha + + + align:start position:0% +out that the gtp-bound form of the alpha +subunit can then bind to another enzyme + + align:start position:0% +subunit can then bind to another enzyme + + + align:start position:0% +subunit can then bind to another enzyme +and that enzyme is adenylate cyclase so + + align:start position:0% +and that enzyme is adenylate cyclase so + + + align:start position:0% +and that enzyme is adenylate cyclase so +we've found we've changed the gdp to GTP + + align:start position:0% +we've found we've changed the gdp to GTP + + + align:start position:0% +we've found we've changed the gdp to GTP +there's a response and we activate the + + align:start position:0% +there's a response and we activate the + + + align:start position:0% +there's a response and we activate the +enzyme known as AC which you look up + + align:start position:0% +enzyme known as AC which you look up + + + align:start position:0% +enzyme known as AC which you look up +here it's called adenylate cyclase so + + align:start position:0% +here it's called adenylate cyclase so + + + align:start position:0% +here it's called adenylate cyclase so +this is a messenger within the cell + + align:start position:0% +this is a messenger within the cell + + + align:start position:0% +this is a messenger within the cell +that's now being generated as a response + + align:start position:0% +that's now being generated as a response + + + align:start position:0% +that's now being generated as a response +to the signal coming from outside + + align:start position:0% +to the signal coming from outside + + + align:start position:0% +to the signal coming from outside +through the GPCR to the alpha subunit of + + align:start position:0% +through the GPCR to the alpha subunit of + + + align:start position:0% +through the GPCR to the alpha subunit of +the g protein which then in its + + align:start position:0% +the g protein which then in its + + + align:start position:0% +the g protein which then in its +gtp-bound state binds adenylate cyclase + + align:start position:0% +gtp-bound state binds adenylate cyclase + + + align:start position:0% +gtp-bound state binds adenylate cyclase +okay is everyone with me and once that + + align:start position:0% +okay is everyone with me and once that + + + align:start position:0% +okay is everyone with me and once that +is bound adenylate cyclase can do its + + align:start position:0% +is bound adenylate cyclase can do its + + + align:start position:0% +is bound adenylate cyclase can do its +biochemistry and the biochemistry that + + align:start position:0% +biochemistry and the biochemistry that + + + align:start position:0% +biochemistry and the biochemistry that +adenylate cyclase + + align:start position:0% +adenylate cyclase + + + align:start position:0% +adenylate cyclase +as shown down here here's a teepee + + align:start position:0% +as shown down here here's a teepee + + + align:start position:0% +as shown down here here's a teepee +adenylate cyclase cyclize --is ATP you + + align:start position:0% +adenylate cyclase cyclize --is ATP you + + + align:start position:0% +adenylate cyclase cyclize --is ATP you +lose two of the phosphates and you get + + align:start position:0% +lose two of the phosphates and you get + + + align:start position:0% +lose two of the phosphates and you get +this molecule known as cyclic a MP which + + align:start position:0% +this molecule known as cyclic a MP which + + + align:start position:0% +this molecule known as cyclic a MP which +is a messenger molecule that will + + align:start position:0% +is a messenger molecule that will + + + align:start position:0% +is a messenger molecule that will +propagate information through the cell + + align:start position:0% +propagate information through the cell + + + align:start position:0% +propagate information through the cell +all right once that happens so now the + + align:start position:0% +all right once that happens so now the + + + align:start position:0% +all right once that happens so now the +adenylate cyclase is activated because + + align:start position:0% +adenylate cyclase is activated because + + + align:start position:0% +adenylate cyclase is activated because +it's bound to the gtp-bound form of the + + align:start position:0% +it's bound to the gtp-bound form of the + + + align:start position:0% +it's bound to the gtp-bound form of the +alpha subunit that means we can make a + + align:start position:0% +alpha subunit that means we can make a + + + align:start position:0% +alpha subunit that means we can make a +bunch of cyclic a MP and cyclic a MP is + + align:start position:0% +bunch of cyclic a MP and cyclic a MP is + + + align:start position:0% +bunch of cyclic a MP and cyclic a MP is +what's known as a second messenger and + + align:start position:0% +what's known as a second messenger and + + + align:start position:0% +what's known as a second messenger and +that often means it's a common messenger + + align:start position:0% +that often means it's a common messenger + + + align:start position:0% +that often means it's a common messenger +in a lot of pathways it shows up quite + + align:start position:0% +in a lot of pathways it shows up quite + + + align:start position:0% +in a lot of pathways it shows up quite +frequently within the wiring of a + + align:start position:0% +frequently within the wiring of a + + + align:start position:0% +frequently within the wiring of a +pathway and it acts locally to where the + + align:start position:0% +pathway and it acts locally to where the + + + align:start position:0% +pathway and it acts locally to where the +pathway is being is being processed + + align:start position:0% +pathway is being is being processed + + + align:start position:0% +pathway is being is being processed +so once cyclic a MP is formed from + + align:start position:0% +so once cyclic a MP is formed from + + + align:start position:0% +so once cyclic a MP is formed from +adenylate site by adenylate cyclase that + + align:start position:0% +adenylate site by adenylate cyclase that + + + align:start position:0% +adenylate site by adenylate cyclase that +then activates an enzyme it activates + + align:start position:0% +then activates an enzyme it activates + + + align:start position:0% +then activates an enzyme it activates +protein protein kinase a so PKA is a + + align:start position:0% +protein protein kinase a so PKA is a + + + align:start position:0% +protein protein kinase a so PKA is a +kinase it's actually a serine threonine + + align:start position:0% +kinase it's actually a serine threonine + + + align:start position:0% +kinase it's actually a serine threonine +kinase and that then results in certain + + align:start position:0% +kinase and that then results in certain + + + align:start position:0% +kinase and that then results in certain +proteins within the cell becoming + + align:start position:0% +proteins within the cell becoming + + + align:start position:0% +proteins within the cell becoming +phosphorylated to continue propagating + + align:start position:0% +phosphorylated to continue propagating + + + align:start position:0% +phosphorylated to continue propagating +our effect so we have specificity by the + + align:start position:0% +our effect so we have specificity by the + + + align:start position:0% +our effect so we have specificity by the +adrenaline binding we have amplification + + align:start position:0% +adrenaline binding we have amplification + + + align:start position:0% +adrenaline binding we have amplification +somewhere in this pathway so I told you + + align:start position:0% +somewhere in this pathway so I told you + + + align:start position:0% +somewhere in this pathway so I told you +that many pathways go through steps + + align:start position:0% +that many pathways go through steps + + + align:start position:0% +that many pathways go through steps +where you start amplifying the signal + + align:start position:0% +where you start amplifying the signal + + + align:start position:0% +where you start amplifying the signal +where do you think is the first stage in + + align:start position:0% +where do you think is the first stage in + + + align:start position:0% +where do you think is the first stage in +this set of transformations that I + + align:start position:0% +this set of transformations that I + + + align:start position:0% +this set of transformations that I +describe to you where you start + + align:start position:0% +describe to you where you start + + + align:start position:0% +describe to you where you start +amplifying the information think about + + align:start position:0% +amplifying the information think about + + + align:start position:0% +amplifying the information think about +what each of the events comprises what + + align:start position:0% +what each of the events comprises what + + + align:start position:0% +what each of the events comprises what +what is it what's you know is this one + + align:start position:0% +what is it what's you know is this one + + + align:start position:0% +what is it what's you know is this one +binding to one + + align:start position:0% +binding to one + + + align:start position:0% +binding to one +one event or is it one binding to one + + align:start position:0% +one event or is it one binding to one + + + align:start position:0% +one event or is it one binding to one +and we get multiple events where is the + + align:start position:0% +and we get multiple events where is the + + + align:start position:0% +and we get multiple events where is the +first step of amplification that's + + align:start position:0% +first step of amplification that's + + + align:start position:0% +first step of amplification that's +essential because it wouldn't do us any + + align:start position:0% +essential because it wouldn't do us any + + + align:start position:0% +essential because it wouldn't do us any +good if we make one molecule of ATP at + + align:start position:0% +good if we make one molecule of ATP at + + + align:start position:0% +good if we make one molecule of ATP at +the end of the day we've got to make + + align:start position:0% +the end of the day we've got to make + + + align:start position:0% +the end of the day we've got to make +dozens and dozens of molecules of ATP + + align:start position:0% +dozens and dozens of molecules of ATP + + + align:start position:0% +dozens and dozens of molecules of ATP +what what's the first event that could + + align:start position:0% +what what's the first event that could + + + align:start position:0% +what what's the first event that could +be an amplification over there yeah when + + align:start position:0% +be an amplification over there yeah when + + + align:start position:0% +be an amplification over there yeah when +it's made yes + + align:start position:0% +it's made yes + + + align:start position:0% +it's made yes +so this let's go through them one by + + align:start position:0% +so this let's go through them one by + + + align:start position:0% +so this let's go through them one by +pnes two one great + + align:start position:0% +pnes two one great + + + align:start position:0% +pnes two one great +once one binds to one one of these is + + align:start position:0% +once one binds to one one of these is + + + align:start position:0% +once one binds to one one of these is +released it gets converted to one of + + align:start position:0% +released it gets converted to one of + + + align:start position:0% +released it gets converted to one of +these once one of these is made + + align:start position:0% +these once one of these is made + + + align:start position:0% +these once one of these is made +adenylate cyclase is an enzyme so it can + + align:start position:0% +adenylate cyclase is an enzyme so it can + + + align:start position:0% +adenylate cyclase is an enzyme so it can +make a bunch of cyclic ANP which can + + align:start position:0% +make a bunch of cyclic ANP which can + + + align:start position:0% +make a bunch of cyclic ANP which can +then activate a bunch of protein kinase + + align:start position:0% +then activate a bunch of protein kinase + + + align:start position:0% +then activate a bunch of protein kinase +a which can then phosphorylate a bunch + + align:start position:0% +a which can then phosphorylate a bunch + + + align:start position:0% +a which can then phosphorylate a bunch +of cellular proteins so we got an + + align:start position:0% +of cellular proteins so we got an + + + align:start position:0% +of cellular proteins so we got an +expansion of our response all right so + + align:start position:0% +expansion of our response all right so + + + align:start position:0% +expansion of our response all right so +everyone does that make sense to + + align:start position:0% +everyone does that make sense to + + + align:start position:0% +everyone does that make sense to +everyone + + align:start position:0% +everyone + + + align:start position:0% +everyone +so amplification is really important + + align:start position:0% +so amplification is really important + + + align:start position:0% +so amplification is really important +feedback is also important if you ended + + align:start position:0% +feedback is also important if you ended + + + align:start position:0% +feedback is also important if you ended +up needing an EpiPen because you have an + + align:start position:0% +up needing an EpiPen because you have an + + + align:start position:0% +up needing an EpiPen because you have an +allergic response you might remember + + align:start position:0% +allergic response you might remember + + + align:start position:0% +allergic response you might remember +that you've got the jitters forever + + align:start position:0% +that you've got the jitters forever + + + align:start position:0% +that you've got the jitters forever +because there's too much firing an + + align:start position:0% +because there's too much firing an + + + align:start position:0% +because there's too much firing an +action going on but in though that the + + align:start position:0% +action going on but in though that the + + + align:start position:0% +action going on but in though that the +fight-or-flight response there's + + align:start position:0% +fight-or-flight response there's + + + align:start position:0% +fight-or-flight response there's +feedback at a certain stage that slows + + align:start position:0% +feedback at a certain stage that slows + + + align:start position:0% +feedback at a certain stage that slows +down this entire process and that + + align:start position:0% +down this entire process and that + + + align:start position:0% +down this entire process and that +feedback actually comes from an enzyme + + align:start position:0% +feedback actually comes from an enzyme + + + align:start position:0% +feedback actually comes from an enzyme +that chomps up the cyclic ANP to make it + + align:start position:0% +that chomps up the cyclic ANP to make it + + + align:start position:0% +that chomps up the cyclic ANP to make it +inactive as a second messenger so + + align:start position:0% +inactive as a second messenger so + + + align:start position:0% +inactive as a second messenger so +there's feedback in this process okay + + align:start position:0% +there's feedback in this process okay + + + align:start position:0% +there's feedback in this process okay +now what happens within the cell to get + + align:start position:0% +now what happens within the cell to get + + + align:start position:0% +now what happens within the cell to get +us that biological response this is a + + align:start position:0% +us that biological response this is a + + + align:start position:0% +us that biological response this is a +sort of a shortened version of what's + + align:start position:0% +sort of a shortened version of what's + + + align:start position:0% +sort of a shortened version of what's +happening so epinephrine binds here we + + align:start position:0% +happening so epinephrine binds here we + + + align:start position:0% +happening so epinephrine binds here we +are with the alpha subunit with cyclic + + align:start position:0% +are with the alpha subunit with cyclic + + + align:start position:0% +are with the alpha subunit with cyclic +A&P you know through each one of these + + align:start position:0% +A&P you know through each one of these + + + align:start position:0% +A&P you know through each one of these +you might make twenty molecules of + + align:start position:0% +you might make twenty molecules of + + + align:start position:0% +you might make twenty molecules of +cyclic ANP that would in activate many + + align:start position:0% +cyclic ANP that would in activate many + + + align:start position:0% +cyclic ANP that would in activate many +many PKS + + align:start position:0% +many PKS + + + align:start position:0% +many PKS +and then you go through a series of + + align:start position:0% +and then you go through a series of + + + align:start position:0% +and then you go through a series of +biochemical steps where different + + align:start position:0% +biochemical steps where different + + + align:start position:0% +biochemical steps where different +enzymes are activated with the overall + + align:start position:0% +enzymes are activated with the overall + + + align:start position:0% +enzymes are activated with the overall +goal of in the liver chewing up glycogen + + align:start position:0% +goal of in the liver chewing up glycogen + + + align:start position:0% +goal of in the liver chewing up glycogen +okay so glycogen is a pretty + + align:start position:0% +okay so glycogen is a pretty + + + align:start position:0% +okay so glycogen is a pretty +impenetrable polymer of carbohydrates + + align:start position:0% +impenetrable polymer of carbohydrates + + + align:start position:0% +impenetrable polymer of carbohydrates +and you need several enzymes to start to + + align:start position:0% +and you need several enzymes to start to + + + align:start position:0% +and you need several enzymes to start to +break glycogen down + + align:start position:0% +break glycogen down + + + align:start position:0% +break glycogen down +to make glucose phosphate and so these + + align:start position:0% +to make glucose phosphate and so these + + + align:start position:0% +to make glucose phosphate and so these +enzymes here of Prospero lays B kinase a + + align:start position:0% +enzymes here of Prospero lays B kinase a + + + align:start position:0% +enzymes here of Prospero lays B kinase a +glycation phosphorylase all end up + + align:start position:0% +glycation phosphorylase all end up + + + align:start position:0% +glycation phosphorylase all end up +converting glycogen into glucose + + align:start position:0% +converting glycogen into glucose + + + align:start position:0% +converting glycogen into glucose +1-phosphate so you access your liver + + align:start position:0% +1-phosphate so you access your liver + + + align:start position:0% +1-phosphate so you access your liver +stores of stored carbohydrate which is + + align:start position:0% +stores of stored carbohydrate which is + + + align:start position:0% +stores of stored carbohydrate which is +in a polymeric form to get a lot of + + align:start position:0% +in a polymeric form to get a lot of + + + align:start position:0% +in a polymeric form to get a lot of +glucose phosphate which is then + + align:start position:0% +glucose phosphate which is then + + + align:start position:0% +glucose phosphate which is then +hydrolyzed to glucose which then hits + + align:start position:0% +hydrolyzed to glucose which then hits + + + align:start position:0% +hydrolyzed to glucose which then hits +the blood system and then you can + + align:start position:0% +the blood system and then you can + + + align:start position:0% +the blood system and then you can +deliver glucose to all the cells to go + + align:start position:0% +deliver glucose to all the cells to go + + + align:start position:0% +deliver glucose to all the cells to go +glycolysis and make ATP and every + + align:start position:0% +glycolysis and make ATP and every + + + align:start position:0% +glycolysis and make ATP and every +glucose molecule as you know can really + + align:start position:0% +glucose molecule as you know can really + + + align:start position:0% +glucose molecule as you know can really +turn out ATP so what we see in this + + align:start position:0% +turn out ATP so what we see in this + + + align:start position:0% +turn out ATP so what we see in this +process is going through the entire + + align:start position:0% +process is going through the entire + + + align:start position:0% +process is going through the entire +dynamics of the system where we've seen + + align:start position:0% +dynamics of the system where we've seen + + + align:start position:0% +dynamics of the system where we've seen +specificity amplification and feedback + + align:start position:0% +specificity amplification and feedback + + + align:start position:0% +specificity amplification and feedback +later on I'll describe integration to + + align:start position:0% +later on I'll describe integration to + + + align:start position:0% +later on I'll describe integration to +you ok + + align:start position:0% +you ok + + + align:start position:0% +you ok +everyone following the series of steps + + align:start position:0% +everyone following the series of steps + + + align:start position:0% +everyone following the series of steps +that go from a Maalik molecular + + align:start position:0% +that go from a Maalik molecular + + + align:start position:0% +that go from a Maalik molecular +messenger to biochemical steps to + + align:start position:0% +messenger to biochemical steps to + + + align:start position:0% +messenger to biochemical steps to +physiological biological response now I + + align:start position:0% +physiological biological response now I + + + align:start position:0% +physiological biological response now I +want to just emphasize one quick thing + + align:start position:0% +want to just emphasize one quick thing + + + align:start position:0% +want to just emphasize one quick thing +here I've got a couple of slides I + + align:start position:0% +here I've got a couple of slides I + + + align:start position:0% +here I've got a couple of slides I +popped in of drug targets about 45% of + + align:start position:0% +popped in of drug targets about 45% of + + + align:start position:0% +popped in of drug targets about 45% of +receptors in cells 25% of the entire + + align:start position:0% +receptors in cells 25% of the entire + + + align:start position:0% +receptors in cells 25% of the entire +drug targets are GPCRs they respond to + + align:start position:0% +drug targets are GPCRs they respond to + + + align:start position:0% +drug targets are GPCRs they respond to +all kinds of signals amines amino acids + + align:start position:0% +all kinds of signals amines amino acids + + + align:start position:0% +all kinds of signals amines amino acids +lipids little peptides proteins + + align:start position:0% +lipids little peptides proteins + + + align:start position:0% +lipids little peptides proteins +nucleosides all commonly going through + + align:start position:0% +nucleosides all commonly going through + + + align:start position:0% +nucleosides all commonly going through +the g-protein coupled receptor to give + + align:start position:0% +the g-protein coupled receptor to give + + + align:start position:0% +the g-protein coupled receptor to give +you a similar phenomenon to what I've + + align:start position:0% +you a similar phenomenon to what I've + + + align:start position:0% +you a similar phenomenon to what I've +described to you and what I thought was + + align:start position:0% +described to you and what I thought was + + + align:start position:0% +described to you and what I thought was +think is particularly interesting this + + align:start position:0% +think is particularly interesting this + + + align:start position:0% +think is particularly interesting this +is not I'm gonna post all of these are + + align:start position:0% +is not I'm gonna post all of these are + + + align:start position:0% +is not I'm gonna post all of these are +slides what I want yous to see this was + + align:start position:0% +slides what I want yous to see this was + + + align:start position:0% +slides what I want yous to see this was +quite a while back but it just shows you + + align:start position:0% +quite a while back but it just shows you + + + align:start position:0% +quite a while back but it just shows you +so many of trademark drugs that targets + + align:start position:0% +so many of trademark drugs that targets + + + align:start position:0% +so many of trademark drugs that targets +different gpcrs they're shown here and + + align:start position:0% +different gpcrs they're shown here and + + + align:start position:0% +different gpcrs they're shown here and +what diseases they're used for to treat + + align:start position:0% +what diseases they're used for to treat + + + align:start position:0% +what diseases they're used for to treat +and what's the generic name of those + + align:start position:0% +and what's the generic name of those + + + align:start position:0% +and what's the generic name of those +drugs so you can see here many many + + align:start position:0% +drugs so you can see here many many + + + align:start position:0% +drugs so you can see here many many +diseases have at the heart and soul of + + align:start position:0% +diseases have at the heart and soul of + + + align:start position:0% +diseases have at the heart and soul of +their the problem different receptors + + align:start position:0% +their the problem different receptors + + + align:start position:0% +their the problem different receptors +and these are all g-protein coupled + + align:start position:0% +and these are all g-protein coupled + + + align:start position:0% +and these are all g-protein coupled +receptors that are treated with small + + align:start position:0% +receptors that are treated with small + + + align:start position:0% +receptors that are treated with small +molecules the bind to the + + align:start position:0% +molecules the bind to the + + + align:start position:0% +molecules the bind to the +and often glue it in an inactive state + + align:start position:0% +and often glue it in an inactive state + + + align:start position:0% +and often glue it in an inactive state +so it can't then bind to an activating + + align:start position:0% +so it can't then bind to an activating + + + align:start position:0% +so it can't then bind to an activating +signal and have all the rest of the + + align:start position:0% +signal and have all the rest of the + + + align:start position:0% +signal and have all the rest of the +events occur there are very few + + align:start position:0% +events occur there are very few + + + align:start position:0% +events occur there are very few +structures of the g-protein coupled + + align:start position:0% +structures of the g-protein coupled + + + align:start position:0% +structures of the g-protein coupled +receptors but there are some of them so + + align:start position:0% +receptors but there are some of them so + + + align:start position:0% +receptors but there are some of them so +many of the target g-protein coupled + + align:start position:0% +many of the target g-protein coupled + + + align:start position:0% +many of the target g-protein coupled +receptors can be modeled computationally + + align:start position:0% +receptors can be modeled computationally + + + align:start position:0% +receptors can be modeled computationally +and then you can do a lot of work where + + align:start position:0% +and then you can do a lot of work where + + + align:start position:0% +and then you can do a lot of work where +you actually model the receptor in a + + align:start position:0% +you actually model the receptor in a + + + align:start position:0% +you actually model the receptor in a +membrane environment and start searching + + align:start position:0% +membrane environment and start searching + + + align:start position:0% +membrane environment and start searching +for drugs through computational + + align:start position:0% +for drugs through computational + + + align:start position:0% +for drugs through computational +approaches and I thought a lot of you + + align:start position:0% +approaches and I thought a lot of you + + + align:start position:0% +approaches and I thought a lot of you +might be interested in this because this + + align:start position:0% +might be interested in this because this + + + align:start position:0% +might be interested in this because this +is a really strong axis where + + align:start position:0% +is a really strong axis where + + + align:start position:0% +is a really strong axis where +bioinformatics confirmation and advanced + + align:start position:0% +bioinformatics confirmation and advanced + + + align:start position:0% +bioinformatics confirmation and advanced +physics in molecular dynamics can be + + align:start position:0% +physics in molecular dynamics can be + + + align:start position:0% +physics in molecular dynamics can be +brought to bear on drug discovery when + + align:start position:0% +brought to bear on drug discovery when + + + align:start position:0% +brought to bear on drug discovery when +you don't have perfect molecular models + + align:start position:0% +you don't have perfect molecular models + + + align:start position:0% +you don't have perfect molecular models +of your targets okay so now we're gonna + + align:start position:0% +of your targets okay so now we're gonna + + + align:start position:0% +of your targets okay so now we're gonna +move to a different kind of signal we're + + align:start position:0% +move to a different kind of signal we're + + + align:start position:0% +move to a different kind of signal we're +gonna talk about the receptor tyrosine + + align:start position:0% +gonna talk about the receptor tyrosine + + + align:start position:0% +gonna talk about the receptor tyrosine +kinase ISM alright so in the receptor + + align:start position:0% +kinase ISM alright so in the receptor + + + align:start position:0% +kinase ISM alright so in the receptor +tyrosine kinase responses we can often + + align:start position:0% +tyrosine kinase responses we can often + + + align:start position:0% +tyrosine kinase responses we can often +see very similar paradigms to what I've + + align:start position:0% +see very similar paradigms to what I've + + + align:start position:0% +see very similar paradigms to what I've +just shown you but there is an important + + align:start position:0% +just shown you but there is an important + + + align:start position:0% +just shown you but there is an important +distinction receptor tyrosine kinase is + + align:start position:0% + + + + align:start position:0% + +we often call these are T Ches so that's + + align:start position:0% +we often call these are T Ches so that's + + + align:start position:0% +we often call these are T Ches so that's +their shorthand so over here I described + + align:start position:0% +their shorthand so over here I described + + + align:start position:0% +their shorthand so over here I described +to you two different kinase 'iz that we + + align:start position:0% +to you two different kinase 'iz that we + + + align:start position:0% +to you two different kinase 'iz that we +have kinase a--'s that modify threonine + + align:start position:0% +have kinase a--'s that modify threonine + + + align:start position:0% +have kinase a--'s that modify threonine +serine and tyrosine the receptor + + align:start position:0% +serine and tyrosine the receptor + + + align:start position:0% +serine and tyrosine the receptor +tyrosine kinase is a subset of tyrosine + + align:start position:0% +tyrosine kinase is a subset of tyrosine + + + align:start position:0% +tyrosine kinase is a subset of tyrosine +kinase --is that form part of a receptor + + align:start position:0% +kinase --is that form part of a receptor + + + align:start position:0% +kinase --is that form part of a receptor +so if you were to think about various + + align:start position:0% +so if you were to think about various + + + align:start position:0% +so if you were to think about various +kinase 'iz you would have the serine + + align:start position:0% +kinase 'iz you would have the serine + + + align:start position:0% +kinase 'iz you would have the serine +threonine and you would have the + + align:start position:0% +threonine and you would have the + + + align:start position:0% +threonine and you would have the +tyrosine ones but these would be + + align:start position:0% +tyrosine ones but these would be + + + align:start position:0% +tyrosine ones but these would be +differentiated into the ones that are + + align:start position:0% +differentiated into the ones that are + + + align:start position:0% +differentiated into the ones that are +parked part of a membrane protein the + + align:start position:0% +parked part of a membrane protein the + + + align:start position:0% +parked part of a membrane protein the +rtks and then the ones that are soluble + + align:start position:0% +rtks and then the ones that are soluble + + + align:start position:0% +rtks and then the ones that are soluble +in the cytoplasm + + align:start position:0% +in the cytoplasm + + + align:start position:0% +in the cytoplasm +and the serine threonine ones are most + + align:start position:0% +and the serine threonine ones are most + + + align:start position:0% +and the serine threonine ones are most +commonly soluble in the cytoplasm I'm + + align:start position:0% +commonly soluble in the cytoplasm I'm + + + align:start position:0% +commonly soluble in the cytoplasm I'm +going to focus on the receptor tyrosine + + align:start position:0% +going to focus on the receptor tyrosine + + + align:start position:0% +going to focus on the receptor tyrosine +kinases because they do slightly + + align:start position:0% +kinases because they do slightly + + + align:start position:0% +kinases because they do slightly +different activities when they signal + + align:start position:0% +different activities when they signal + + + align:start position:0% +different activities when they signal +relative to the GPCRs so let's once + + align:start position:0% +relative to the GPCRs so let's once + + + align:start position:0% +relative to the GPCRs so let's once +again this situation another paradigm + + align:start position:0% +again this situation another paradigm + + + align:start position:0% +again this situation another paradigm +where you see a series of events but + + align:start position:0% +where you see a series of events but + + + align:start position:0% +where you see a series of events but +with a number of the receptor tyrosine + + align:start position:0% +with a number of the receptor tyrosine + + + align:start position:0% +with a number of the receptor tyrosine +kinase pathways the ultimate action ends + + align:start position:0% +kinase pathways the ultimate action ends + + + align:start position:0% +kinase pathways the ultimate action ends +up being in the nucleus where as a + + align:start position:0% +up being in the nucleus where as a + + + align:start position:0% +up being in the nucleus where as a +result of an extracellular signal you + + align:start position:0% +result of an extracellular signal you + + + align:start position:0% +result of an extracellular signal you +get a series of events that ends up with + + align:start position:0% +get a series of events that ends up with + + + align:start position:0% +get a series of events that ends up with +a protein being sent into the nucleus + + align:start position:0% +a protein being sent into the nucleus + + + align:start position:0% +a protein being sent into the nucleus +and that protein may be a transcription + + align:start position:0% +and that protein may be a transcription + + + align:start position:0% +and that protein may be a transcription +factor the binds to a promoter region + + align:start position:0% +factor the binds to a promoter region + + + align:start position:0% +factor the binds to a promoter region +and as a result of that you'll get gene + + align:start position:0% +and as a result of that you'll get gene + + + align:start position:0% +and as a result of that you'll get gene +transcription occur + + align:start position:0% +transcription occur + + + align:start position:0% +transcription occur +you'll transcribe a gene make a + + align:start position:0% +you'll transcribe a gene make a + + + align:start position:0% +you'll transcribe a gene make a +messenger RNA that will leave the + + align:start position:0% +messenger RNA that will leave the + + + align:start position:0% +messenger RNA that will leave the +nucleus and cause action within the cell + + align:start position:0% +nucleus and cause action within the cell + + + align:start position:0% +nucleus and cause action within the cell +so this is a little bit different than + + align:start position:0% +so this is a little bit different than + + + align:start position:0% +so this is a little bit different than +the other response that was mainly + + align:start position:0% +the other response that was mainly + + + align:start position:0% +the other response that was mainly +cytoplasmic okay so let's take a look at + + align:start position:0% +cytoplasmic okay so let's take a look at + + + align:start position:0% +cytoplasmic okay so let's take a look at +the receptor tyrosine kinases receptor + + align:start position:0% +the receptor tyrosine kinases receptor + + + align:start position:0% +the receptor tyrosine kinases receptor +tyrosine kinases are proteins that span + + align:start position:0% +tyrosine kinases are proteins that span + + + align:start position:0% +tyrosine kinases are proteins that span +the membrane but rather differently from + + align:start position:0% +the membrane but rather differently from + + + align:start position:0% +the membrane but rather differently from +the gpcrs and they have a domain that's + + align:start position:0% +the gpcrs and they have a domain that's + + + align:start position:0% +the gpcrs and they have a domain that's +extracellular just a single + + align:start position:0% +extracellular just a single + + + align:start position:0% +extracellular just a single +transmembrane domain this is out this is + + align:start position:0% +transmembrane domain this is out this is + + + align:start position:0% +transmembrane domain this is out this is +in and then they have an intracellular + + align:start position:0% +in and then they have an intracellular + + + align:start position:0% +in and then they have an intracellular +domain this would be where the ligand + + align:start position:0% +domain this would be where the ligand + + + align:start position:0% +domain this would be where the ligand +binds this would be how there's some + + align:start position:0% +binds this would be how there's some + + + align:start position:0% +binds this would be how there's some +kind of signal transducing and this + + align:start position:0% +kind of signal transducing and this + + + align:start position:0% +kind of signal transducing and this +would be a kinase domain okay so how do + + align:start position:0% +would be a kinase domain okay so how do + + + align:start position:0% +would be a kinase domain okay so how do +we get the information in when we saw + + align:start position:0% +we get the information in when we saw + + + align:start position:0% +we get the information in when we saw +the gpcrs we saw the ability of those + + align:start position:0% +the gpcrs we saw the ability of those + + + align:start position:0% +the gpcrs we saw the ability of those +7tms to kind of reorganize and send + + align:start position:0% +7tms to kind of reorganize and send + + + align:start position:0% +7tms to kind of reorganize and send +information in the cell with the + + align:start position:0% +information in the cell with the + + + align:start position:0% +information in the cell with the +receptor tyrosine kinase --is it's kind + + align:start position:0% +receptor tyrosine kinase --is it's kind + + + align:start position:0% +receptor tyrosine kinase --is it's kind +of different there are regions of the + + align:start position:0% +of different there are regions of the + + + align:start position:0% +of different there are regions of the +membrane where there are a lot of these + + align:start position:0% +membrane where there are a lot of these + + + align:start position:0% +membrane where there are a lot of these +proteins they commonly bind small + + align:start position:0% +proteins they commonly bind small + + + align:start position:0% +proteins they commonly bind small +peptides and protein molecules and when + + align:start position:0% +peptides and protein molecules and when + + + align:start position:0% +peptides and protein molecules and when +they're in their activated form once the + + align:start position:0% +they're in their activated form once the + + + align:start position:0% +they're in their activated form once the +small protein binds the receptor + + align:start position:0% +small protein binds the receptor + + + align:start position:0% +small protein binds the receptor +tyrosine try + + align:start position:0% +tyrosine try + + + align:start position:0% +tyrosine try +forms a dimeric structure that is two of + + align:start position:0% +forms a dimeric structure that is two of + + + align:start position:0% +forms a dimeric structure that is two of +these get together only upon + + align:start position:0% +these get together only upon + + + align:start position:0% +these get together only upon +ligand-binding they move together once + + align:start position:0% +ligand-binding they move together once + + + align:start position:0% +ligand-binding they move together once +there is a ligand bound and then what + + align:start position:0% +there is a ligand bound and then what + + + align:start position:0% +there is a ligand bound and then what +happens is that the tyrosine kinase + + align:start position:0% +happens is that the tyrosine kinase + + + align:start position:0% +happens is that the tyrosine kinase +domains phosphorylate each other and + + align:start position:0% +domains phosphorylate each other and + + + align:start position:0% +domains phosphorylate each other and +that's activation in the case of + + align:start position:0% +that's activation in the case of + + + align:start position:0% +that's activation in the case of +receptor tyrosine kinases so when the + + align:start position:0% +receptor tyrosine kinases so when the + + + align:start position:0% +receptor tyrosine kinases so when the +small protein ligand is not around this + + align:start position:0% +small protein ligand is not around this + + + align:start position:0% +small protein ligand is not around this +is a singleton it doesn't work on itself + + align:start position:0% +is a singleton it doesn't work on itself + + + align:start position:0% +is a singleton it doesn't work on itself +once this ligand binds interactions + + align:start position:0% +once this ligand binds interactions + + + align:start position:0% +once this ligand binds interactions +change you get a dimeric structure where + + align:start position:0% +change you get a dimeric structure where + + + align:start position:0% +change you get a dimeric structure where +one kinase can cost correlate what's + + align:start position:0% +one kinase can cost correlate what's + + + align:start position:0% +one kinase can cost correlate what's +called in trans the other kinase domain + + align:start position:0% +called in trans the other kinase domain + + + align:start position:0% +called in trans the other kinase domain +so it's different from the GPCRs it's a + + align:start position:0% +so it's different from the GPCRs it's a + + + align:start position:0% +so it's different from the GPCRs it's a +different kind of feel to it but it's + + align:start position:0% +different kind of feel to it but it's + + + align:start position:0% +different kind of feel to it but it's +still a dynamic transient signal let's + + align:start position:0% +still a dynamic transient signal let's + + + align:start position:0% +still a dynamic transient signal let's +take a look at this within a cell and + + align:start position:0% +take a look at this within a cell and + + + align:start position:0% +take a look at this within a cell and +see what kinds of responses and this is + + align:start position:0% +see what kinds of responses and this is + + + align:start position:0% +see what kinds of responses and this is +in our response to EGF which is + + align:start position:0% +in our response to EGF which is + + + align:start position:0% +in our response to EGF which is +epidermal growth factor + + align:start position:0% +epidermal growth factor + + + align:start position:0% +epidermal growth factor +it's a cytokine that promotes cell + + align:start position:0% +it's a cytokine that promotes cell + + + align:start position:0% +it's a cytokine that promotes cell +division so a lot happens with respect + + align:start position:0% +division so a lot happens with respect + + + align:start position:0% +division so a lot happens with respect +to the action of a cell not to produce + + align:start position:0% +to the action of a cell not to produce + + + align:start position:0% +to the action of a cell not to produce +ATP but now to respond by producing all + + align:start position:0% +ATP but now to respond by producing all + + + align:start position:0% +ATP but now to respond by producing all +the elements that enable cells to grow + + align:start position:0% +the elements that enable cells to grow + + + align:start position:0% +the elements that enable cells to grow +and proliferate so the epidermal growth + + align:start position:0% +and proliferate so the epidermal growth + + + align:start position:0% +and proliferate so the epidermal growth +factor binds you get dimerization upon + + align:start position:0% +factor binds you get dimerization upon + + + align:start position:0% +factor binds you get dimerization upon +that dimerization the kinase domain in + + align:start position:0% +that dimerization the kinase domain in + + + align:start position:0% +that dimerization the kinase domain in +one structure in the blue one + + align:start position:0% +one structure in the blue one + + + align:start position:0% +one structure in the blue one +phosphorylates the other and vice versa + + align:start position:0% +phosphorylates the other and vice versa + + + align:start position:0% +phosphorylates the other and vice versa +they phosphorylate each other + + align:start position:0% +they phosphorylate each other + + + align:start position:0% +they phosphorylate each other +intermolecular ly once that has happened + + align:start position:0% +intermolecular ly once that has happened + + + align:start position:0% +intermolecular ly once that has happened +through the auspices of another protein + + align:start position:0% +through the auspices of another protein + + + align:start position:0% +through the auspices of another protein +i won't bother you with the name of this + + align:start position:0% +i won't bother you with the name of this + + + align:start position:0% +i won't bother you with the name of this +phosphorylated intracellular RT k binds + + align:start position:0% +phosphorylated intracellular RT k binds + + + align:start position:0% +phosphorylated intracellular RT k binds +to a small g-protein in this case it's a + + align:start position:0% +to a small g-protein in this case it's a + + + align:start position:0% +to a small g-protein in this case it's a +monomeric g-protein not one of the + + align:start position:0% +monomeric g-protein not one of the + + + align:start position:0% +monomeric g-protein not one of the +trimeric ones a small one known as + + align:start position:0% +trimeric ones a small one known as + + + align:start position:0% +trimeric ones a small one known as +wrasse once that binding event occurs + + align:start position:0% +wrasse once that binding event occurs + + + align:start position:0% +wrasse once that binding event occurs +guess what wrasse gets activated it's + + align:start position:0% +guess what wrasse gets activated it's + + + align:start position:0% +guess what wrasse gets activated it's +now binding GTP instead of gdp and then + + align:start position:0% +now binding GTP instead of gdp and then + + + align:start position:0% +now binding GTP instead of gdp and then +it starts going through a sequence of + + align:start position:0% +it starts going through a sequence of + + + align:start position:0% +it starts going through a sequence of +events where there's a ton + + align:start position:0% +events where there's a ton + + + align:start position:0% +events where there's a ton +of cellular phosphorylate controlled + + align:start position:0% +of cellular phosphorylate controlled + + + align:start position:0% +of cellular phosphorylate controlled +cellular phosphorylation events the + + align:start position:0% +cellular phosphorylation events the + + + align:start position:0% +cellular phosphorylation events the +result in moving a protein into the + + align:start position:0% +result in moving a protein into the + + + align:start position:0% +result in moving a protein into the +nucleus that helps form a transcription + + align:start position:0% +nucleus that helps form a transcription + + + align:start position:0% +nucleus that helps form a transcription +complex the results in cellular + + align:start position:0% +complex the results in cellular + + + align:start position:0% +complex the results in cellular +proliferation similar but different + + align:start position:0% +proliferation similar but different + + + align:start position:0% +proliferation similar but different +series of events they're still + + align:start position:0% +series of events they're still + + + align:start position:0% +series of events they're still +amplification they're still dynamics and + + align:start position:0% +amplification they're still dynamics and + + + align:start position:0% +amplification they're still dynamics and +in this case it's a lot of + + align:start position:0% +in this case it's a lot of + + + align:start position:0% +in this case it's a lot of +phosphorylation events and what I want + + align:start position:0% +phosphorylation events and what I want + + + align:start position:0% +phosphorylation events and what I want +to sort of define for you is that many + + align:start position:0% +to sort of define for you is that many + + + align:start position:0% +to sort of define for you is that many +of these pathways are in trouble in + + align:start position:0% +of these pathways are in trouble in + + + align:start position:0% +of these pathways are in trouble in +disease state speed inflammation neuro + + align:start position:0% +disease state speed inflammation neuro + + + align:start position:0% +disease state speed inflammation neuro +degeneration or cancer there are a + + align:start position:0% +degeneration or cancer there are a + + + align:start position:0% +degeneration or cancer there are a +Bearnaise aberrant behavior of proteins + + align:start position:0% +Bearnaise aberrant behavior of proteins + + + align:start position:0% +Bearnaise aberrant behavior of proteins +within these pathways that cause them to + + align:start position:0% +within these pathways that cause them to + + + align:start position:0% +within these pathways that cause them to +go wrong cause cells to proliferate out + + align:start position:0% +go wrong cause cells to proliferate out + + + align:start position:0% +go wrong cause cells to proliferate out +of control or undergo bad responses and + + align:start position:0% +of control or undergo bad responses and + + + align:start position:0% +of control or undergo bad responses and +that is why these proteins end up being + + align:start position:0% +that is why these proteins end up being + + + align:start position:0% +that is why these proteins end up being +therapeutic targets like the g-protein + + align:start position:0% +therapeutic targets like the g-protein + + + align:start position:0% +therapeutic targets like the g-protein +coupled receptors okay so we've seen the + + align:start position:0% +coupled receptors okay so we've seen the + + + align:start position:0% +coupled receptors okay so we've seen the +characteristics of signaling we've seen + + align:start position:0% +characteristics of signaling we've seen + + + align:start position:0% +characteristics of signaling we've seen +a signal we've seen amplification we've + + align:start position:0% +a signal we've seen amplification we've + + + align:start position:0% +a signal we've seen amplification we've +seen responses but I just want to + + align:start position:0% +seen responses but I just want to + + + align:start position:0% +seen responses but I just want to +quickly show you is an idea about + + align:start position:0% +quickly show you is an idea about + + + align:start position:0% +quickly show you is an idea about +integration so here's an idea with two + + align:start position:0% +integration so here's an idea with two + + + align:start position:0% +integration so here's an idea with two +signaling pathways that sort of end up + + align:start position:0% +signaling pathways that sort of end up + + + align:start position:0% +signaling pathways that sort of end up +with the same signal outside where you + + align:start position:0% +with the same signal outside where you + + + align:start position:0% +with the same signal outside where you +integrate actions through two different + + align:start position:0% +integrate actions through two different + + + align:start position:0% +integrate actions through two different +signaling pathways to achieve a bigger + + align:start position:0% +signaling pathways to achieve a bigger + + + align:start position:0% +signaling pathways to achieve a bigger +different kind of response so that's + + align:start position:0% +different kind of response so that's + + + align:start position:0% +different kind of response so that's +that last hallmark of signaling pathways + + align:start position:0% +that last hallmark of signaling pathways + + + align:start position:0% +that last hallmark of signaling pathways +it's not that every pathway is clean and + + align:start position:0% +it's not that every pathway is clean and + + + align:start position:0% +it's not that every pathway is clean and +straight + + align:start position:0% +straight + + + align:start position:0% +straight +it has crosstalk with other pathways and + + align:start position:0% +it has crosstalk with other pathways and + + + align:start position:0% +it has crosstalk with other pathways and +you get amplified or different responses + + align:start position:0% +you get amplified or different responses + + + align:start position:0% +you get amplified or different responses +tremendously complicated I want to give + + align:start position:0% +tremendously complicated I want to give + + + align:start position:0% +tremendously complicated I want to give +you one more term and then I'll show one + + align:start position:0% +you one more term and then I'll show one + + + align:start position:0% +you one more term and then I'll show one +table when these pathways go wrong it's + + align:start position:0% +table when these pathways go wrong it's + + + align:start position:0% +table when these pathways go wrong it's +often because switches get stuck on so + + align:start position:0% +often because switches get stuck on so + + + align:start position:0% +often because switches get stuck on so +for example a gtp a g-protein gets stuck + + align:start position:0% +for example a gtp a g-protein gets stuck + + + align:start position:0% +for example a gtp a g-protein gets stuck +in its gtp bound state or doesn't even + + align:start position:0% +in its gtp bound state or doesn't even + + + align:start position:0% +in its gtp bound state or doesn't even +need gtp to be activated or a tyrosine + + align:start position:0% +need gtp to be activated or a tyrosine + + + align:start position:0% +need gtp to be activated or a tyrosine +kinase is stuck activated and that's + + align:start position:0% +kinase is stuck activated and that's + + + align:start position:0% +kinase is stuck activated and that's +what's called constitutively active + + align:start position:0% + + + + align:start position:0% + +I mean base basically meaning it's + + align:start position:0% +I mean base basically meaning it's + + + align:start position:0% +I mean base basically meaning it's +permanently on so many of the diseases + + align:start position:0% +permanently on so many of the diseases + + + align:start position:0% +permanently on so many of the diseases +that are caused by mutations in your + + align:start position:0% +that are caused by mutations in your + + + align:start position:0% +that are caused by mutations in your +genome not genetic diseases but + + align:start position:0% +genome not genetic diseases but + + + align:start position:0% +genome not genetic diseases but +mutations in your genes in some + + align:start position:0% +mutations in your genes in some + + + align:start position:0% +mutations in your genes in some +particular cells end up with + + align:start position:0% +particular cells end up with + + + align:start position:0% +particular cells end up with +constitutive activation where you don't + + align:start position:0% +constitutive activation where you don't + + + align:start position:0% +constitutive activation where you don't +need a signal to have a response and so + + align:start position:0% +need a signal to have a response and so + + + align:start position:0% +need a signal to have a response and so +for example cells may proliferate out of + + align:start position:0% +for example cells may proliferate out of + + + align:start position:0% +for example cells may proliferate out of +control so that is an important term to + + align:start position:0% +control so that is an important term to + + + align:start position:0% +control so that is an important term to +know and understand because constitutive + + align:start position:0% +know and understand because constitutive + + + align:start position:0% +know and understand because constitutive +activation basically means that a + + align:start position:0% +activation basically means that a + + + align:start position:0% +activation basically means that a +receptor may be active in the absence of + + align:start position:0% +receptor may be active in the absence of + + + align:start position:0% +receptor may be active in the absence of +a ligand and I believe this is my last + + align:start position:0% +a ligand and I believe this is my last + + + align:start position:0% +a ligand and I believe this is my last +slide I just wanted to leave you with + + align:start position:0% +slide I just wanted to leave you with + + + align:start position:0% +slide I just wanted to leave you with +this when one thinks of GPC ours their + + align:start position:0% +this when one thinks of GPC ours their + + + align:start position:0% +this when one thinks of GPC ours their +tremendous therapeutic targets the world + + align:start position:0% +tremendous therapeutic targets the world + + + align:start position:0% +tremendous therapeutic targets the world +of kinase is is no less important these + + align:start position:0% +of kinase is is no less important these + + + align:start position:0% +of kinase is is no less important these +scale is in billions of dollars spent on + + align:start position:0% +scale is in billions of dollars spent on + + + align:start position:0% +scale is in billions of dollars spent on +developing molecules that may be + + align:start position:0% +developing molecules that may be + + + align:start position:0% +developing molecules that may be +curative of diseases that involve + + align:start position:0% +curative of diseases that involve + + + align:start position:0% +curative of diseases that involve +dysregulated signaling and what you see + + align:start position:0% +dysregulated signaling and what you see + + + align:start position:0% +dysregulated signaling and what you see +on this I want to point out two things + + align:start position:0% +on this I want to point out two things + + + align:start position:0% +on this I want to point out two things +I'm going to go in of course this thing + + align:start position:0% +I'm going to go in of course this thing + + + align:start position:0% +I'm going to go in of course this thing +stopped working at the last minute but + + align:start position:0% +stopped working at the last minute but + + + align:start position:0% +stopped working at the last minute but +what I want to point out is this + + align:start position:0% +what I want to point out is this + + + align:start position:0% +what I want to point out is this +particular bar this represents the + + align:start position:0% +particular bar this represents the + + + align:start position:0% +particular bar this represents the +billions of dollars spent on protein + + align:start position:0% +billions of dollars spent on protein + + + align:start position:0% +billions of dollars spent on protein +kinase inhibitors over-fire a five-year + + align:start position:0% +kinase inhibitors over-fire a five-year + + + align:start position:0% +kinase inhibitors over-fire a five-year +period and it's just escalating and + + align:start position:0% +period and it's just escalating and + + + align:start position:0% +period and it's just escalating and +escalating + + align:start position:0% +escalating + + + align:start position:0% +escalating +similarly monoclonal antibodies are very + + align:start position:0% +similarly monoclonal antibodies are very + + + align:start position:0% +similarly monoclonal antibodies are very +important but the small molecule drugs + + align:start position:0% +important but the small molecule drugs + + + align:start position:0% +important but the small molecule drugs +hold a real dominance what do these + + align:start position:0% +hold a real dominance what do these + + + align:start position:0% +hold a real dominance what do these +drugs do they enable you to have small + + align:start position:0% +drugs do they enable you to have small + + + align:start position:0% +drugs do they enable you to have small +molecules that can go into dysregulated + + align:start position:0% +molecules that can go into dysregulated + + + align:start position:0% +molecules that can go into dysregulated +signaling pathways and stop the activity + + align:start position:0% +signaling pathways and stop the activity + + + align:start position:0% +signaling pathways and stop the activity +somewhere in the pathway to avoid + + align:start position:0% +somewhere in the pathway to avoid + + + align:start position:0% +somewhere in the pathway to avoid +signals going constantly to the nucleus + + align:start position:0% +signals going constantly to the nucleus + + + align:start position:0% +signals going constantly to the nucleus +and turning things on all the time so + + align:start position:0% +and turning things on all the time so + + + align:start position:0% +and turning things on all the time so +that both of these types of functions in + + align:start position:0% +that both of these types of functions in + + + align:start position:0% +that both of these types of functions in +cellular signaling once you want to + + align:start position:0% +cellular signaling once you want to + + + align:start position:0% +cellular signaling once you want to +understand both from a biological + + align:start position:0% +understand both from a biological + + + align:start position:0% +understand both from a biological +perspective but from a medical + + align:start position:0% +perspective but from a medical + + + align:start position:0% +perspective but from a medical +perspective okay + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/mw0jJm_3KXs.txt b/mw0jJm_3KXs.txt new file mode 100644 index 0000000000000000000000000000000000000000..bf9dd5231e90e8d0fdc197903a3ce9720e9cd740 --- /dev/null +++ b/mw0jJm_3KXs.txt @@ -0,0 +1,763 @@ +align:start position:0% + +now it's time to evaluate our models on + + align:start position:0% +now it's time to evaluate our models on + + + align:start position:0% +now it's time to evaluate our models on +the testing set so the first model we're + + align:start position:0% +the testing set so the first model we're + + + align:start position:0% +the testing set so the first model we're +gonna want to look at is that smart + + align:start position:0% +gonna want to look at is that smart + + + align:start position:0% +gonna want to look at is that smart +baseline model that basically just took + + align:start position:0% +baseline model that basically just took + + + align:start position:0% +baseline model that basically just took +a look at the polling results from the + + align:start position:0% +a look at the polling results from the + + + align:start position:0% +a look at the polling results from the +Rasmussen poll and use those to + + align:start position:0% +Rasmussen poll and use those to + + + align:start position:0% +Rasmussen poll and use those to +determine who is predicted to win the + + align:start position:0% +determine who is predicted to win the + + + align:start position:0% +determine who is predicted to win the +election so it's very easy to compute + + align:start position:0% +election so it's very easy to compute + + + align:start position:0% +election so it's very easy to compute +the outcome for this simple baseline on + + align:start position:0% +the outcome for this simple baseline on + + + align:start position:0% +the outcome for this simple baseline on +the testing set we're gonna want to + + align:start position:0% +the testing set we're gonna want to + + + align:start position:0% +the testing set we're gonna want to +table the testing set outcome variable + + align:start position:0% +table the testing set outcome variable + + + align:start position:0% +table the testing set outcome variable +Republican and we're going to compare + + align:start position:0% +Republican and we're going to compare + + + align:start position:0% +Republican and we're going to compare +that against the actual outcome of the + + align:start position:0% +that against the actual outcome of the + + + align:start position:0% +that against the actual outcome of the +smart baseline which as you recall would + + align:start position:0% +smart baseline which as you recall would + + + align:start position:0% +smart baseline which as you recall would +be the sign of the testing sets + + align:start position:0% +be the sign of the testing sets + + + align:start position:0% +be the sign of the testing sets +rasmussen variables and we can see that + + align:start position:0% +rasmussen variables and we can see that + + + align:start position:0% +rasmussen variables and we can see that +for these results there are 18 times + + align:start position:0% +for these results there are 18 times + + + align:start position:0% +for these results there are 18 times +where the smart baseline predicted that + + align:start position:0% +where the smart baseline predicted that + + + align:start position:0% +where the smart baseline predicted that +the Democrat would win it's correct 21 + + align:start position:0% +the Democrat would win it's correct 21 + + + align:start position:0% +the Democrat would win it's correct 21 +were predicted the Republican would win + + align:start position:0% +were predicted the Republican would win + + + align:start position:0% +were predicted the Republican would win +and was correct two times when it was + + align:start position:0% +and was correct two times when it was + + + align:start position:0% +and was correct two times when it was +inconclusive and four times where it + + align:start position:0% +inconclusive and four times where it + + + align:start position:0% +inconclusive and four times where it +predicted Republican but the Democratic + + align:start position:0% +predicted Republican but the Democratic + + + align:start position:0% +predicted Republican but the Democratic +actually won so that's four mistakes and + + align:start position:0% +actually won so that's four mistakes and + + + align:start position:0% +actually won so that's four mistakes and +two inconclusive results on the testing + + align:start position:0% +two inconclusive results on the testing + + + align:start position:0% +two inconclusive results on the testing +set so this is going to be what we're + + align:start position:0% +set so this is going to be what we're + + + align:start position:0% +set so this is going to be what we're +going to compare our logistic regression + + align:start position:0% +going to compare our logistic regression + + + align:start position:0% +going to compare our logistic regression +based model against so we need to obtain + + align:start position:0% +based model against so we need to obtain + + + align:start position:0% +based model against so we need to obtain +final testing set prediction from our + + align:start position:0% +final testing set prediction from our + + + align:start position:0% +final testing set prediction from our +model so we selected mod two which was + + align:start position:0% +model so we selected mod two which was + + + align:start position:0% +model so we selected mod two which was +the two variable model so we'll say test + + align:start position:0% +the two variable model so we'll say test + + + align:start position:0% +the two variable model so we'll say test +prediction is equal to the predict of + + align:start position:0% +prediction is equal to the predict of + + + align:start position:0% +prediction is equal to the predict of +that model that we selected now since + + align:start position:0% +that model that we selected now since + + + align:start position:0% +that model that we selected now since +we're actually making testing set + + align:start position:0% +we're actually making testing set + + + align:start position:0% +we're actually making testing set +predictions will pass in new data is + + align:start position:0% +predictions will pass in new data is + + + align:start position:0% +predictions will pass in new data is +equal to test and again since we want + + align:start position:0% +equal to test and again since we want + + + align:start position:0% +equal to test and again since we want +probabilities to be returned we're going + + align:start position:0% +probabilities to be returned we're going + + + align:start position:0% +probabilities to be returned we're going +to pass type equals response and the + + align:start position:0% +to pass type equals response and the + + + align:start position:0% +to pass type equals response and the +moment of truth we're finally going to + + align:start position:0% +moment of truth we're finally going to + + + align:start position:0% +moment of truth we're finally going to +table the test set Republican value + + align:start position:0% +table the test set Republican value + + + align:start position:0% +table the test set Republican value +against the test prediction being + + align:start position:0% +against the test prediction being + + + align:start position:0% +against the test prediction being +greater than or equal to zero point five + + align:start position:0% +greater than or equal to zero point five + + + align:start position:0% +greater than or equal to zero point five +at least a 50% probability of the + + align:start position:0% +at least a 50% probability of the + + + align:start position:0% +at least a 50% probability of the +republic you money and we see that for + + align:start position:0% +republic you money and we see that for + + + align:start position:0% +republic you money and we see that for +this particular case in all but one of + + align:start position:0% +this particular case in all but one of + + + align:start position:0% +this particular case in all but one of +the 45 observation + + align:start position:0% +the 45 observation + + + align:start position:0% +the 45 observation +in the testing set were correct now we + + align:start position:0% +in the testing set were correct now we + + + align:start position:0% +in the testing set were correct now we +could have tried changing this threshold + + align:start position:0% +could have tried changing this threshold + + + align:start position:0% +could have tried changing this threshold +from 0.5 to other values and kind of + + align:start position:0% +from 0.5 to other values and kind of + + + align:start position:0% +from 0.5 to other values and kind of +compute it out an ROC curve but that + + align:start position:0% +compute it out an ROC curve but that + + + align:start position:0% +compute it out an ROC curve but that +doesn't quite make as much sense in this + + align:start position:0% +doesn't quite make as much sense in this + + + align:start position:0% +doesn't quite make as much sense in this +setting where we're just trying to + + align:start position:0% +setting where we're just trying to + + + align:start position:0% +setting where we're just trying to +accurately predict the outcome of each + + align:start position:0% +accurately predict the outcome of each + + + align:start position:0% +accurately predict the outcome of each +state and we don't care more about one + + align:start position:0% +state and we don't care more about one + + + align:start position:0% +state and we don't care more about one +sort of error when we predicted a + + align:start position:0% +sort of error when we predicted a + + + align:start position:0% +sort of error when we predicted a +Republican it was actually Democrat and + + align:start position:0% +Republican it was actually Democrat and + + + align:start position:0% +Republican it was actually Democrat and +the other when we predict a Democrat and + + align:start position:0% +the other when we predict a Democrat and + + + align:start position:0% +the other when we predict a Democrat and +it was actually Republican so in this + + align:start position:0% +it was actually Republican so in this + + + align:start position:0% +it was actually Republican so in this +particular case we feel ok just using + + align:start position:0% +particular case we feel ok just using + + + align:start position:0% +particular case we feel ok just using +the cutoff of 0.5 to evaluate our model + + align:start position:0% +the cutoff of 0.5 to evaluate our model + + + align:start position:0% +the cutoff of 0.5 to evaluate our model +so let's take a look now at the mistake + + align:start position:0% +so let's take a look now at the mistake + + + align:start position:0% +so let's take a look now at the mistake +we made and see if we can kind of + + align:start position:0% +we made and see if we can kind of + + + align:start position:0% +we made and see if we can kind of +understand what's going on so to + + align:start position:0% +understand what's going on so to + + + align:start position:0% +understand what's going on so to +actually pull out the mistake we made we + + align:start position:0% +actually pull out the mistake we made we + + + align:start position:0% +actually pull out the mistake we made we +can just take a subset of the testing + + align:start position:0% +can just take a subset of the testing + + + align:start position:0% +can just take a subset of the testing +set and limited to when we predicted + + align:start position:0% +set and limited to when we predicted + + + align:start position:0% +set and limited to when we predicted +true but actually the Democrat one which + + align:start position:0% +true but actually the Democrat one which + + + align:start position:0% +true but actually the Democrat one which +is the the case when that one failed so + + align:start position:0% +is the the case when that one failed so + + + align:start position:0% +is the the case when that one failed so +this would be when test prediction is + + align:start position:0% +this would be when test prediction is + + + align:start position:0% +this would be when test prediction is +greater than or equal to 0.5 and it was + + align:start position:0% +greater than or equal to 0.5 and it was + + + align:start position:0% +greater than or equal to 0.5 and it was +not a Republican so Republican was equal + + align:start position:0% +not a Republican so Republican was equal + + + align:start position:0% +not a Republican so Republican was equal +to zero so here is that subset which + + align:start position:0% +to zero so here is that subset which + + + align:start position:0% +to zero so here is that subset which +just has one observation since we made + + align:start position:0% +just has one observation since we made + + + align:start position:0% +just has one observation since we made +just one mistake so this was for the + + align:start position:0% +just one mistake so this was for the + + + align:start position:0% +just one mistake so this was for the +year 2012 the testing set year this was + + align:start position:0% +year 2012 the testing set year this was + + + align:start position:0% +year 2012 the testing set year this was +the state of Florida and kind of looking + + align:start position:0% +the state of Florida and kind of looking + + + align:start position:0% +the state of Florida and kind of looking +through these predictor variables we see + + align:start position:0% +through these predictor variables we see + + + align:start position:0% +through these predictor variables we see +why we made the mistake right + + align:start position:0% +why we made the mistake right + + + align:start position:0% +why we made the mistake right +the Rasmussen poll gave the Republican a + + align:start position:0% +the Rasmussen poll gave the Republican a + + + align:start position:0% +the Rasmussen poll gave the Republican a +two percentage point lead survey u-s-a + + align:start position:0% +two percentage point lead survey u-s-a + + + align:start position:0% +two percentage point lead survey u-s-a +called a tie discount said there were + + align:start position:0% +called a tie discount said there were + + + align:start position:0% +called a tie discount said there were +six more polls that predicted republican + + align:start position:0% +six more polls that predicted republican + + + align:start position:0% +six more polls that predicted republican +than democrat and two-thirds of the + + align:start position:0% +than democrat and two-thirds of the + + + align:start position:0% +than democrat and two-thirds of the +polls predicted the Republican was going + + align:start position:0% +polls predicted the Republican was going + + + align:start position:0% +polls predicted the Republican was going +to win but actually in this case the + + align:start position:0% +to win but actually in this case the + + + align:start position:0% +to win but actually in this case the +Republican didn't win Barack Obama won + + align:start position:0% +Republican didn't win Barack Obama won + + + align:start position:0% +Republican didn't win Barack Obama won +the the state of Florida in 2012 over + + align:start position:0% +the the state of Florida in 2012 over + + + align:start position:0% +the the state of Florida in 2012 over +Mitt Romney so the models here are not + + align:start position:0% +Mitt Romney so the models here are not + + + align:start position:0% +Mitt Romney so the models here are not +magic and given this sort of data it's + + align:start position:0% +magic and given this sort of data it's + + + align:start position:0% +magic and given this sort of data it's +it's pretty unsurprising that our model + + align:start position:0% +it's pretty unsurprising that our model + + + align:start position:0% +it's pretty unsurprising that our model +actually didn't get Florida correct in + + align:start position:0% +actually didn't get Florida correct in + + + align:start position:0% +actually didn't get Florida correct in +this case and made the mistake however + + align:start position:0% +this case and made the mistake however + + + align:start position:0% +this case and made the mistake however +overall it seems to be outperforming the + + align:start position:0% +overall it seems to be outperforming the + + + align:start position:0% +overall it seems to be outperforming the +smart baseline that we selected and so + + align:start position:0% +smart baseline that we selected and so + + + align:start position:0% +smart baseline that we selected and so +we think that maybe this would be a nice + + align:start position:0% +we think that maybe this would be a nice + + + align:start position:0% +we think that maybe this would be a nice +model to use in the election prediction \ No newline at end of file diff --git a/n19qLvOY-rc.txt b/n19qLvOY-rc.txt new file mode 100644 index 0000000000000000000000000000000000000000..1f79ffdc0bc88872aa1081c63fb291a1cff92c49 --- /dev/null +++ b/n19qLvOY-rc.txt @@ -0,0 +1,763 @@ +align:start position:0% + +in this lecture we'll be trying to + + align:start position:0% +in this lecture we'll be trying to + + + align:start position:0% +in this lecture we'll be trying to +understand sentiment of tweets about the + + align:start position:0% +understand sentiment of tweets about the + + + align:start position:0% +understand sentiment of tweets about the +company Apple Apple is a computer + + align:start position:0% +company Apple Apple is a computer + + + align:start position:0% +company Apple Apple is a computer +company known for its laptops phones + + align:start position:0% +company known for its laptops phones + + + align:start position:0% +company known for its laptops phones +tablets and personal media players while + + align:start position:0% +tablets and personal media players while + + + align:start position:0% +tablets and personal media players while +Apple has a large number of fans they + + align:start position:0% +Apple has a large number of fans they + + + align:start position:0% +Apple has a large number of fans they +also have a large number of people who + + align:start position:0% +also have a large number of people who + + + align:start position:0% +also have a large number of people who +don't like their products and they have + + align:start position:0% +don't like their products and they have + + + align:start position:0% +don't like their products and they have +several competitors to better understand + + align:start position:0% +several competitors to better understand + + + align:start position:0% +several competitors to better understand +public perception Apple wants to monitor + + align:start position:0% +public perception Apple wants to monitor + + + align:start position:0% +public perception Apple wants to monitor +how people feel over time and how people + + align:start position:0% +how people feel over time and how people + + + align:start position:0% +how people feel over time and how people +receive new announcements our challenge + + align:start position:0% +receive new announcements our challenge + + + align:start position:0% +receive new announcements our challenge +in this lecture is to see if we can + + align:start position:0% +in this lecture is to see if we can + + + align:start position:0% +in this lecture is to see if we can +correctly classifies tweets as being + + align:start position:0% +correctly classifies tweets as being + + + align:start position:0% +correctly classifies tweets as being +negative positive or neither about Apple + + align:start position:0% +negative positive or neither about Apple + + + align:start position:0% +negative positive or neither about Apple +to collect the data and needed for this + + align:start position:0% +to collect the data and needed for this + + + align:start position:0% +to collect the data and needed for this +task we had to perform two steps the + + align:start position:0% +task we had to perform two steps the + + + align:start position:0% +task we had to perform two steps the +first was to collect data about tweets + + align:start position:0% +first was to collect data about tweets + + + align:start position:0% +first was to collect data about tweets +from the internet Twitter data is + + align:start position:0% +from the internet Twitter data is + + + align:start position:0% +from the internet Twitter data is +publicly available and you can collect + + align:start position:0% +publicly available and you can collect + + + align:start position:0% +publicly available and you can collect +it through scraping the website or by + + align:start position:0% +it through scraping the website or by + + + align:start position:0% +it through scraping the website or by +using a special interface for + + align:start position:0% +using a special interface for + + + align:start position:0% +using a special interface for +programmers that Twitter provides called + + align:start position:0% +programmers that Twitter provides called + + + align:start position:0% +programmers that Twitter provides called +an API the sender of the tweet might be + + align:start position:0% +an API the sender of the tweet might be + + + align:start position:0% +an API the sender of the tweet might be +useful to predict sentiment but will + + align:start position:0% +useful to predict sentiment but will + + + align:start position:0% +useful to predict sentiment but will +ignore it to keep our data anonymized so + + align:start position:0% +ignore it to keep our data anonymized so + + + align:start position:0% +ignore it to keep our data anonymized so +we'll just be using the text of the + + align:start position:0% +we'll just be using the text of the + + + align:start position:0% +we'll just be using the text of the +tweet then we need to construct the + + align:start position:0% +tweet then we need to construct the + + + align:start position:0% +tweet then we need to construct the +outcome variable for these tweets which + + align:start position:0% +outcome variable for these tweets which + + + align:start position:0% +outcome variable for these tweets which +means that we have to label them as + + align:start position:0% +means that we have to label them as + + + align:start position:0% +means that we have to label them as +positive negative or neutral sentiment + + align:start position:0% +positive negative or neutral sentiment + + + align:start position:0% +positive negative or neutral sentiment +we would like to label thousands of + + align:start position:0% +we would like to label thousands of + + + align:start position:0% +we would like to label thousands of +tweets and we know that two people might + + align:start position:0% +tweets and we know that two people might + + + align:start position:0% +tweets and we know that two people might +disagree over the correct classification + + align:start position:0% +disagree over the correct classification + + + align:start position:0% +disagree over the correct classification +of a tweet so to do this efficiently one + + align:start position:0% +of a tweet so to do this efficiently one + + + align:start position:0% +of a tweet so to do this efficiently one +option is to use the Amazon Mechanical + + align:start position:0% +option is to use the Amazon Mechanical + + + align:start position:0% +option is to use the Amazon Mechanical +Turk so what is the Amazon Mechanical + + align:start position:0% +Turk so what is the Amazon Mechanical + + + align:start position:0% +Turk so what is the Amazon Mechanical +Turk it allows people to break tasks + + align:start position:0% +Turk it allows people to break tasks + + + align:start position:0% +Turk it allows people to break tasks +down into small components and then + + align:start position:0% +down into small components and then + + + align:start position:0% +down into small components and then +enables them to distribute these tasks + + align:start position:0% +enables them to distribute these tasks + + + align:start position:0% +enables them to distribute these tasks +online to be solved by people all over + + align:start position:0% +online to be solved by people all over + + + align:start position:0% +online to be solved by people all over +the world people can sign up to perform + + align:start position:0% +the world people can sign up to perform + + + align:start position:0% +the world people can sign up to perform +the available tasks for a fee ask the + + align:start position:0% +the available tasks for a fee ask the + + + align:start position:0% +the available tasks for a fee ask the +task creator we pay the workers a fixed + + align:start position:0% +task creator we pay the workers a fixed + + + align:start position:0% +task creator we pay the workers a fixed +amount per completed task for example we + + align:start position:0% +amount per completed task for example we + + + align:start position:0% +amount per completed task for example we +might pay two cents for a single + + align:start position:0% +might pay two cents for a single + + + align:start position:0% +might pay two cents for a single +classified tweet the Amazon Mechanical + + align:start position:0% +classified tweet the Amazon Mechanical + + + align:start position:0% +classified tweet the Amazon Mechanical +Turk serves as a broker + + align:start position:0% +Turk serves as a broker + + + align:start position:0% +Turk serves as a broker +and takes a small cut of the money many + + align:start position:0% +and takes a small cut of the money many + + + align:start position:0% +and takes a small cut of the money many +of the tasks on the Mechanical Turk + + align:start position:0% +of the tasks on the Mechanical Turk + + + align:start position:0% +of the tasks on the Mechanical Turk +require human intelligence like + + align:start position:0% +require human intelligence like + + + align:start position:0% +require human intelligence like +classifying the sentiment of a tweet but + + align:start position:0% +classifying the sentiment of a tweet but + + + align:start position:0% +classifying the sentiment of a tweet but +these tasks may be time-consuming or + + align:start position:0% +these tasks may be time-consuming or + + + align:start position:0% +these tasks may be time-consuming or +require building otherwise unneeded + + align:start position:0% +require building otherwise unneeded + + + align:start position:0% +require building otherwise unneeded +capacity for the creator of the task and + + align:start position:0% +capacity for the creator of the task and + + + align:start position:0% +capacity for the creator of the task and +so it's appealing to outsource the job + + align:start position:0% +so it's appealing to outsource the job + + + align:start position:0% +so it's appealing to outsource the job +the task that we put on the Amazon + + align:start position:0% +the task that we put on the Amazon + + + align:start position:0% +the task that we put on the Amazon +Mechanical Turk was to judge the + + align:start position:0% +Mechanical Turk was to judge the + + + align:start position:0% +Mechanical Turk was to judge the +sentiment expressed by the following + + align:start position:0% +sentiment expressed by the following + + + align:start position:0% +sentiment expressed by the following +item toward the software company Apple + + align:start position:0% +item toward the software company Apple + + + align:start position:0% +item toward the software company Apple +the items we gave them were tweets that + + align:start position:0% +the items we gave them were tweets that + + + align:start position:0% +the items we gave them were tweets that +we had collected the workers could pick + + align:start position:0% +we had collected the workers could pick + + + align:start position:0% +we had collected the workers could pick +from the following options as their + + align:start position:0% +from the following options as their + + + align:start position:0% +from the following options as their +response strongly negative negative + + align:start position:0% +response strongly negative negative + + + align:start position:0% +response strongly negative negative +neutral positive and strongly positive + + align:start position:0% +neutral positive and strongly positive + + + align:start position:0% +neutral positive and strongly positive +we represented each of these outcomes as + + align:start position:0% +we represented each of these outcomes as + + + align:start position:0% +we represented each of these outcomes as +a number on the scale from negative 2 to + + align:start position:0% +a number on the scale from negative 2 to + + + align:start position:0% +a number on the scale from negative 2 to +2 we had 5 workers label each tweet the + + align:start position:0% +2 we had 5 workers label each tweet the + + + align:start position:0% +2 we had 5 workers label each tweet the +graph on the right shows the + + align:start position:0% +graph on the right shows the + + + align:start position:0% +graph on the right shows the +distribution of the number of tweets + + align:start position:0% +distribution of the number of tweets + + + align:start position:0% +distribution of the number of tweets +classified into each of the categories + + align:start position:0% +classified into each of the categories + + + align:start position:0% +classified into each of the categories +we can see here that the majority of + + align:start position:0% +we can see here that the majority of + + + align:start position:0% +we can see here that the majority of +tweets were classified as neutral with a + + align:start position:0% +tweets were classified as neutral with a + + + align:start position:0% +tweets were classified as neutral with a +small number classified as strongly + + align:start position:0% +small number classified as strongly + + + align:start position:0% +small number classified as strongly +negative or strongly positive then for + + align:start position:0% +negative or strongly positive then for + + + align:start position:0% +negative or strongly positive then for +each tweet we take the average of the 5 + + align:start position:0% +each tweet we take the average of the 5 + + + align:start position:0% +each tweet we take the average of the 5 +scores given by the 5 workers for + + align:start position:0% +scores given by the 5 workers for + + + align:start position:0% +scores given by the 5 workers for +example the tweet love you Apple + + align:start position:0% +example the tweet love you Apple + + + align:start position:0% +example the tweet love you Apple +was seen as strongly positive by four of + + align:start position:0% +was seen as strongly positive by four of + + + align:start position:0% +was seen as strongly positive by four of +the workers and positive by one of the + + align:start position:0% +the workers and positive by one of the + + + align:start position:0% +the workers and positive by one of the +workers so he gets a score of 1.8 the + + align:start position:0% +workers so he gets a score of 1.8 the + + + align:start position:0% +workers so he gets a score of 1.8 the +tweet Apple Twitter happy programmers + + align:start position:0% +tweet Apple Twitter happy programmers + + + align:start position:0% +tweet Apple Twitter happy programmers +day folks was seen a slightly positive + + align:start position:0% +day folks was seen a slightly positive + + + align:start position:0% +day folks was seen a slightly positive +on average and the tweet so disappointed + + align:start position:0% +on average and the tweet so disappointed + + + align:start position:0% +on average and the tweet so disappointed +an apple sold me a MacBook Air that + + align:start position:0% +an apple sold me a MacBook Air that + + + align:start position:0% +an apple sold me a MacBook Air that +won't run my apps so I have to drive + + align:start position:0% +won't run my apps so I have to drive + + + align:start position:0% +won't run my apps so I have to drive +hours to return it they won't let me + + align:start position:0% +hours to return it they won't let me + + + align:start position:0% +hours to return it they won't let me +ship it was seen as pretty negative so + + align:start position:0% +ship it was seen as pretty negative so + + + align:start position:0% +ship it was seen as pretty negative so +now we have a bunch of tweets that are + + align:start position:0% +now we have a bunch of tweets that are + + + align:start position:0% +now we have a bunch of tweets that are +labeled with their sentiment but how do + + align:start position:0% +labeled with their sentiment but how do + + + align:start position:0% +labeled with their sentiment but how do +we build independent variables from the + + align:start position:0% +we build independent variables from the + + + align:start position:0% +we build independent variables from the +text of a tweet to be used to predict + + align:start position:0% +text of a tweet to be used to predict + + + align:start position:0% +text of a tweet to be used to predict +the sentiment in the next video we'll + + align:start position:0% +the sentiment in the next video we'll + + + align:start position:0% +the sentiment in the next video we'll +discuss a technique called bag-of-words + + align:start position:0% +discuss a technique called bag-of-words + + + align:start position:0% +discuss a technique called bag-of-words +that transforms text into independent + + align:start position:0% +that transforms text into independent + + + align:start position:0% +that transforms text into independent +variables \ No newline at end of file diff --git a/oQ2mTN1_bus.txt b/oQ2mTN1_bus.txt new file mode 100644 index 0000000000000000000000000000000000000000..7ab1af1c447cfb76fb02178fc805b11449f977c4 --- /dev/null +++ b/oQ2mTN1_bus.txt @@ -0,0 +1,9387 @@ +align:start position:0% + +today we're going to look at the we're + + align:start position:0% +today we're going to look at the we're + + + align:start position:0% +today we're going to look at the we're +going to start looking into the labor + + align:start position:0% +going to start looking into the labor + + + align:start position:0% +going to start looking into the labor +market now the labor market is very + + align:start position:0% +market now the labor market is very + + + align:start position:0% +market now the labor market is very +interesting for a wide variety of + + align:start position:0% +interesting for a wide variety of + + + align:start position:0% +interesting for a wide variety of +reasons that we will not discuss in this + + align:start position:0% +reasons that we will not discuss in this + + + align:start position:0% +reasons that we will not discuss in this +course because it's not about labor + + align:start position:0% +course because it's not about labor + + + align:start position:0% +course because it's not about labor +economics it's about macroeconomics ICS + + align:start position:0% +economics it's about macroeconomics ICS + + + align:start position:0% +economics it's about macroeconomics ICS +but there are at least two reasons uh + + align:start position:0% +but there are at least two reasons uh + + + align:start position:0% +but there are at least two reasons uh +why labor markets are very important in + + align:start position:0% +why labor markets are very important in + + + align:start position:0% +why labor markets are very important in +in + + align:start position:0% +in + + + align:start position:0% +in +macro H one is because things like the + + align:start position:0% +macro H one is because things like the + + + align:start position:0% +macro H one is because things like the +unemployment rate is an very important + + align:start position:0% +unemployment rate is an very important + + + align:start position:0% +unemployment rate is an very important +indicator of the micro economic health + + align:start position:0% +indicator of the micro economic health + + + align:start position:0% +indicator of the micro economic health +ER of a country or an economy and the + + align:start position:0% +ER of a country or an economy and the + + + align:start position:0% +ER of a country or an economy and the +second one which is quite relevant these + + align:start position:0% +second one which is quite relevant these + + + align:start position:0% +second one which is quite relevant these +days is that the inflation rate + + align:start position:0% +days is that the inflation rate + + + align:start position:0% +days is that the inflation rate +is one of the main drivers of the + + align:start position:0% +is one of the main drivers of the + + + align:start position:0% +is one of the main drivers of the +inflation rate is what is going on in + + align:start position:0% +inflation rate is what is going on in + + + align:start position:0% +inflation rate is what is going on in +the in the in the labor market and and + + align:start position:0% +the in the in the labor market and and + + + align:start position:0% +the in the in the labor market and and +we will try to understand this this + + align:start position:0% +we will try to understand this this + + + align:start position:0% +we will try to understand this this +mechanism in the next couple of + + align:start position:0% +mechanism in the next couple of + + + align:start position:0% +mechanism in the next couple of +lectures what you have there is the is + + align:start position:0% +lectures what you have there is the is + + + align:start position:0% +lectures what you have there is the is +the inflation rate in the US and I I'm + + align:start position:0% +the inflation rate in the US and I I'm + + + align:start position:0% +the inflation rate in the US and I I'm +shown you these picture several times + + align:start position:0% +shown you these picture several times + + + align:start position:0% +shown you these picture several times +you know after going through a long + + align:start position:0% +you know after going through a long + + + align:start position:0% +you know after going through a long +period in which the inflation rate + + align:start position:0% +period in which the inflation rate + + + align:start position:0% +period in which the inflation rate +hoover around 2% you know with Cycles H + + align:start position:0% +hoover around 2% you know with Cycles H + + + align:start position:0% +hoover around 2% you know with Cycles H +we are experiencing an episode of very + + align:start position:0% +we are experiencing an episode of very + + + align:start position:0% +we are experiencing an episode of very +high inflation + + align:start position:0% +high inflation + + + align:start position:0% +high inflation +things are coming down but they're still + + align:start position:0% +things are coming down but they're still + + + align:start position:0% +things are coming down but they're still +at extremely high levels 6% or so and + + align:start position:0% +at extremely high levels 6% or so and + + + align:start position:0% +at extremely high levels 6% or so and +actually very recently these numbers + + align:start position:0% +actually very recently these numbers + + + align:start position:0% +actually very recently these numbers +have picked up again a little um so + + align:start position:0% +have picked up again a little um so + + + align:start position:0% +have picked up again a little um so +that's very high very high inflation + + align:start position:0% +that's very high very high inflation + + + align:start position:0% +that's very high very high inflation +rate way too high for an economic like + + align:start position:0% +rate way too high for an economic like + + + align:start position:0% +rate way too high for an economic like +the US to feel comfortable with and uh + + align:start position:0% +the US to feel comfortable with and uh + + + align:start position:0% +the US to feel comfortable with and uh +whenever you + + align:start position:0% +whenever you + + + align:start position:0% +whenever you +know some member of the fomc comes out + + align:start position:0% +know some member of the fomc comes out + + + align:start position:0% +know some member of the fomc comes out +and explains why interest rate are so + + align:start position:0% +and explains why interest rate are so + + + align:start position:0% +and explains why interest rate are so +high at this moment it says and and and + + align:start position:0% +high at this moment it says and and and + + + align:start position:0% +high at this moment it says and and and +and explains why they're likely to + + align:start position:0% +and explains why they're likely to + + + align:start position:0% +and explains why they're likely to +remain high for quite a while they say + + align:start position:0% +remain high for quite a while they say + + + align:start position:0% +remain high for quite a while they say +well look inflation is uncomfort + + align:start position:0% +well look inflation is uncomfort + + + align:start position:0% +well look inflation is uncomfort +uncomfortably high at high levels and + + align:start position:0% +uncomfortably high at high levels and + + + align:start position:0% +uncomfortably high at high levels and +and labor market conditions are very + + align:start position:0% +and labor market conditions are very + + + align:start position:0% +and labor market conditions are very +tight and that suggests that the + + align:start position:0% +tight and that suggests that the + + + align:start position:0% +tight and that suggests that the +inflation problem is not likely to go + + align:start position:0% +inflation problem is not likely to go + + + align:start position:0% +inflation problem is not likely to go +away in in in in in the near future okay + + align:start position:0% +away in in in in in the near future okay + + + align:start position:0% +away in in in in in the near future okay +so that's something we need to + + align:start position:0% +so that's something we need to + + + align:start position:0% +so that's something we need to +understand in mro why is it that the + + align:start position:0% +understand in mro why is it that the + + + align:start position:0% +understand in mro why is it that the +labor market being tied says anything + + align:start position:0% +labor market being tied says anything + + + align:start position:0% +labor market being tied says anything +about the inflation rate for example + + align:start position:0% +about the inflation rate for example + + + align:start position:0% +about the inflation rate for example +okay and that's the kind of things we're + + align:start position:0% +okay and that's the kind of things we're + + + align:start position:0% +okay and that's the kind of things we're +going to discuss in particular in the on + + align:start position:0% +going to discuss in particular in the on + + + align:start position:0% +going to discuss in particular in the on +on the Monday lecture now today we're + + align:start position:0% +on the Monday lecture now today we're + + + align:start position:0% +on the Monday lecture now today we're +going to start with sort of more basics + + align:start position:0% +going to start with sort of more basics + + + align:start position:0% +going to start with sort of more basics +of the of of of + + align:start position:0% +of the of of of + + + align:start position:0% +of the of of of +the of the labor market ER and uh and + + align:start position:0% +the of the labor market ER and uh and + + + align:start position:0% +the of the labor market ER and uh and +and at the same time we're going to + + align:start position:0% +and at the same time we're going to + + + align:start position:0% +and at the same time we're going to +begin a transition in the course in + + align:start position:0% +begin a transition in the course in + + + align:start position:0% +begin a transition in the course in +which we have been focusing on things + + align:start position:0% +which we have been focusing on things + + + align:start position:0% +which we have been focusing on things +that are H in the very short run into + + align:start position:0% +that are H in the very short run into + + + align:start position:0% +that are H in the very short run into +things that take more time okay H + + align:start position:0% +things that take more time okay H + + + align:start position:0% +things that take more time okay H +because many of the things that we going + + align:start position:0% +because many of the things that we going + + + align:start position:0% +because many of the things that we going +to discuss today are things that you're + + align:start position:0% +to discuss today are things that you're + + + align:start position:0% +to discuss today are things that you're +not likely to see in every single + + align:start position:0% +not likely to see in every single + + + align:start position:0% +not likely to see in every single +quarter but there are things that you're + + align:start position:0% +quarter but there are things that you're + + + align:start position:0% +quarter but there are things that you're +likely to see over averages over you + + align:start position:0% +likely to see over averages over you + + + align:start position:0% +likely to see over averages over you +know several quarters several months + + align:start position:0% +know several quarters several months + + + align:start position:0% +know several quarters several months +that's what we're want to look at today + + align:start position:0% +that's what we're want to look at today + + + align:start position:0% +that's what we're want to look at today +so remember let me just recap a little + + align:start position:0% +so remember let me just recap a little + + + align:start position:0% +so remember let me just recap a little +bit what we have been doing up to now H + + align:start position:0% +bit what we have been doing up to now H + + + align:start position:0% +bit what we have been doing up to now H +we have been looking at this islm model + + align:start position:0% +we have been looking at this islm model + + + align:start position:0% +we have been looking at this islm model +which is a great model it's it's a very + + align:start position:0% +which is a great model it's it's a very + + + align:start position:0% +which is a great model it's it's a very +good Model H to build on but it's a very + + align:start position:0% +good Model H to build on but it's a very + + + align:start position:0% +good Model H to build on but it's a very +nice model starting point to understand + + align:start position:0% +nice model starting point to understand + + + align:start position:0% +nice model starting point to understand +what happens during a recession and what + + align:start position:0% +what happens during a recession and what + + + align:start position:0% +what happens during a recession and what +are the what what are the likely Pol + + align:start position:0% +are the what what are the likely Pol + + + align:start position:0% +are the what what are the likely Pol +what are the likely impact of the + + align:start position:0% +what are the likely impact of the + + + align:start position:0% +what are the likely impact of the +different macroeconomic policies + + align:start position:0% +different macroeconomic policies + + + align:start position:0% +different macroeconomic policies +monetary policy fiscal policy and so on + + align:start position:0% +monetary policy fiscal policy and so on + + + align:start position:0% +monetary policy fiscal policy and so on +it is not such a great model once a um + + align:start position:0% +it is not such a great model once a um + + + align:start position:0% +it is not such a great model once a um +the agre supply side of the economy + + align:start position:0% +the agre supply side of the economy + + + align:start position:0% +the agre supply side of the economy +something we have complet ignore starts + + align:start position:0% +something we have complet ignore starts + + + align:start position:0% +something we have complet ignore starts +becoming binding okay remember that up + + align:start position:0% +becoming binding okay remember that up + + + align:start position:0% +becoming binding okay remember that up +to now in the slm model we had basically + + align:start position:0% +to now in the slm model we had basically + + + align:start position:0% +to now in the slm model we had basically +slm model we had two + + align:start position:0% +slm model we had two + + + align:start position:0% +slm model we had two +assumptions related assumptions One + + align:start position:0% +assumptions related assumptions One + + + align:start position:0% +assumptions related assumptions One +prices were fully sticky they didn't + + align:start position:0% +prices were fully sticky they didn't + + + align:start position:0% +prices were fully sticky they didn't +move at + + align:start position:0% +move at + + + align:start position:0% +move at +all second that output was aggregate + + align:start position:0% +all second that output was aggregate + + + align:start position:0% +all second that output was aggregate +demand determined so whatever aggregate + + align:start position:0% +demand determined so whatever aggregate + + + align:start position:0% +demand determined so whatever aggregate +demand wanted producers found a way to + + align:start position:0% +demand wanted producers found a way to + + + align:start position:0% +demand wanted producers found a way to +produce it at some given + + align:start position:0% +produce it at some given + + + align:start position:0% +produce it at some given +price that's + + align:start position:0% +price that's + + + align:start position:0% +price that's +that that combination is unlikely to + + align:start position:0% +that that combination is unlikely to + + + align:start position:0% +that that combination is unlikely to +happen when for example when + + align:start position:0% +happen when for example when + + + align:start position:0% +happen when for example when +ER firms are finding trouble finding new + + align:start position:0% +ER firms are finding trouble finding new + + + align:start position:0% +ER firms are finding trouble finding new +workers because you know there may more + + align:start position:0% +workers because you know there may more + + + align:start position:0% +workers because you know there may more +demand more demand for his Goods but but + + align:start position:0% +demand more demand for his Goods but but + + + align:start position:0% +demand more demand for his Goods but but +the firm may find it hard to expand + + align:start position:0% +the firm may find it hard to expand + + + align:start position:0% +the firm may find it hard to expand +production and it's also highly likely + + align:start position:0% +production and it's also highly likely + + + align:start position:0% +production and it's also highly likely +that in a situation like that firms are + + align:start position:0% +that in a situation like that firms are + + + align:start position:0% +that in a situation like that firms are +going to want to keep prices constant + + align:start position:0% +going to want to keep prices constant + + + align:start position:0% +going to want to keep prices constant +some point I look you you want to have + + align:start position:0% +some point I look you you want to have + + + align:start position:0% +some point I look you you want to have +lots of meals at my restaurant I cannot + + align:start position:0% +lots of meals at my restaurant I cannot + + + align:start position:0% +lots of meals at my restaurant I cannot +find people to work on my restaurant I I + + align:start position:0% +find people to work on my restaurant I I + + + align:start position:0% +find people to work on my restaurant I I +I'll hide the prices so at least you + + align:start position:0% +I'll hide the prices so at least you + + + align:start position:0% +I'll hide the prices so at least you +know fewer tables and I can manage one + + align:start position:0% +know fewer tables and I can manage one + + + align:start position:0% +know fewer tables and I can manage one +way or the other so + + align:start position:0% +way or the other so + + + align:start position:0% +way or the other so +we're going to start building a mall + + align:start position:0% +we're going to start building a mall + + + align:start position:0% +we're going to start building a mall +that cons makes those takes those things + + align:start position:0% +that cons makes those takes those things + + + align:start position:0% +that cons makes those takes those things +into consideration how what what is the + + align:start position:0% +into consideration how what what is the + + + align:start position:0% +into consideration how what what is the +impact of of a tight supply side of the + + align:start position:0% +impact of of a tight supply side of the + + + align:start position:0% +impact of of a tight supply side of the +economy on on prices and and and how + + align:start position:0% +economy on on prices and and and how + + + align:start position:0% +economy on on prices and and and how +that starts affecting feds back into + + align:start position:0% +that starts affecting feds back into + + + align:start position:0% +that starts affecting feds back into +equilibrium output + + align:start position:0% +equilibrium output + + + align:start position:0% +equilibrium output +eventually H so the main thing I would + + align:start position:0% +eventually H so the main thing I would + + + align:start position:0% +eventually H so the main thing I would +say we're going to do really relative + + align:start position:0% +say we're going to do really relative + + + align:start position:0% +say we're going to do really relative +tolm model in the next two three + + align:start position:0% +tolm model in the next two three + + + align:start position:0% +tolm model in the next two three +lectures is endogenized inflation rate + + align:start position:0% +lectures is endogenized inflation rate + + + align:start position:0% +lectures is endogenized inflation rate +okay we have kep prices fixed but now + + align:start position:0% +okay we have kep prices fixed but now + + + align:start position:0% +okay we have kep prices fixed but now +we're Going endogenize H and and the + + align:start position:0% +we're Going endogenize H and and the + + + align:start position:0% +we're Going endogenize H and and the +story of that endogenization of infl of + + align:start position:0% +story of that endogenization of infl of + + + align:start position:0% +story of that endogenization of infl of +of inflation starts from the labor + + align:start position:0% +of inflation starts from the labor + + + align:start position:0% +of inflation starts from the labor +market and that's the reason we're going + + align:start position:0% +market and that's the reason we're going + + + align:start position:0% +market and that's the reason we're going +to start looking at the labor market + + align:start position:0% +to start looking at the labor market + + + align:start position:0% +to start looking at the labor market +today okay now let me remind you a few + + align:start position:0% +today okay now let me remind you a few + + + align:start position:0% +today okay now let me remind you a few +things that I think we discussed in the + + align:start position:0% +things that I think we discussed in the + + + align:start position:0% +things that I think we discussed in the +first lecture or so or maybe second I + + align:start position:0% +first lecture or so or maybe second I + + + align:start position:0% +first lecture or so or maybe second I +don't remember + + align:start position:0% +don't remember + + + align:start position:0% +don't remember +er um is let me give you a picture of + + align:start position:0% +er um is let me give you a picture of + + + align:start position:0% +er um is let me give you a picture of +the labor market and some variables + + align:start position:0% +the labor market and some variables + + + align:start position:0% +the labor market and some variables +important statistics of the labor market + + align:start position:0% +important statistics of the labor market + + + align:start position:0% +important statistics of the labor market +that are that that that that matter for + + align:start position:0% +that are that that that that matter for + + + align:start position:0% +that are that that that that matter for +for understanding inflation and so on so + + align:start position:0% +for understanding inflation and so on so + + + align:start position:0% +for understanding inflation and so on so +this is a picture this this one that you + + align:start position:0% +this is a picture this this one that you + + + align:start position:0% +this is a picture this this one that you +have in the book of H the lab the the + + align:start position:0% +have in the book of H the lab the the + + + align:start position:0% +have in the book of H the lab the the +labor market it's a picture of the + + align:start position:0% +labor market it's a picture of the + + + align:start position:0% +labor market it's a picture of the +market at some point in 2018 I don't + + align:start position:0% +market at some point in 2018 I don't + + + align:start position:0% +market at some point in 2018 I don't +know when it's a picture at one point ER + + align:start position:0% +know when it's a picture at one point ER + + + align:start position:0% +know when it's a picture at one point ER +and that says at the time the US had + + align:start position:0% +and that says at the time the US had + + + align:start position:0% +and that says at the time the US had +about 330 million people uh that + + align:start position:0% +about 330 million people uh that + + + align:start position:0% +about 330 million people uh that +non-institutional civilian population + + align:start position:0% +non-institutional civilian population + + + align:start position:0% +non-institutional civilian population +that is those people that in principle + + align:start position:0% +that is those people that in principle + + + align:start position:0% +that is those people that in principle +could work H were about 260 million that + + align:start position:0% +could work H were about 260 million that + + + align:start position:0% +could work H were about 260 million that +excludes people under 16 years old + + align:start position:0% +excludes people under 16 years old + + + align:start position:0% +excludes people under 16 years old +people that are incarcerated people that + + align:start position:0% +people that are incarcerated people that + + + align:start position:0% +people that are incarcerated people that +are in the in the armed + + align:start position:0% +are in the in the armed + + + align:start position:0% +are in the in the armed +forces those are excluded from that's + + align:start position:0% +forces those are excluded from that's + + + align:start position:0% +forces those are excluded from that's +the difference that's the reason you + + align:start position:0% +the difference that's the reason you + + + align:start position:0% +the difference that's the reason you +have such a big gap between these two + + align:start position:0% +have such a big gap between these two + + + align:start position:0% +have such a big gap between these two +numbers okay now out of this people that + + align:start position:0% +numbers okay now out of this people that + + + align:start position:0% +numbers okay now out of this people that +potentially could work some of them want + + align:start position:0% +potentially could work some of them want + + + align:start position:0% +potentially could work some of them want +to work and that's why we call this + + align:start position:0% +to work and that's why we call this + + + align:start position:0% +to work and that's why we call this +civilian labor force and then some of + + align:start position:0% +civilian labor force and then some of + + + align:start position:0% +civilian labor force and then some of +them are out of the labor force again at + + align:start position:0% +them are out of the labor force again at + + + align:start position:0% +them are out of the labor force again at +one point in time doesn't mean that + + align:start position:0% +one point in time doesn't mean that + + + align:start position:0% +one point in time doesn't mean that +these people are permanently out of the + + align:start position:0% +these people are permanently out of the + + + align:start position:0% +these people are permanently out of the +labor force it maybe temporarily out of + + align:start position:0% +labor force it maybe temporarily out of + + + align:start position:0% +labor force it maybe temporarily out of +the labor force and so on but but about + + align:start position:0% +the labor force and so on but but about + + + align:start position:0% +the labor force and so on but but about +you know we started with about 330 + + align:start position:0% +you know we started with about 330 + + + align:start position:0% +you know we started with about 330 +million and by the time that we look at + + align:start position:0% +million and by the time that we look at + + + align:start position:0% +million and by the time that we look at +the people that really want to work at + + align:start position:0% +the people that really want to work at + + + align:start position:0% +the people that really want to work at +that point when the picture was taken + + align:start position:0% +that point when the picture was taken + + + align:start position:0% +that point when the picture was taken +was about half of that 162 million + + align:start position:0% +was about half of that 162 million + + + align:start position:0% +was about half of that 162 million +people okay now these 162 million people + + align:start position:0% +people okay now these 162 million people + + + align:start position:0% +people okay now these 162 million people +the the great majority of them are + + align:start position:0% +the the great majority of them are + + + align:start position:0% +the the great majority of them are +typically employed they have a job okay + + align:start position:0% +typically employed they have a job okay + + + align:start position:0% +typically employed they have a job okay +and then there's a group of people that + + align:start position:0% +and then there's a group of people that + + + align:start position:0% +and then there's a group of people that +would want to have a job that's the + + align:start position:0% +would want to have a job that's the + + + align:start position:0% +would want to have a job that's the +reason they're part of a civilian labor + + align:start position:0% +reason they're part of a civilian labor + + + align:start position:0% +reason they're part of a civilian labor +force but do not have one and that's + + align:start position:0% +force but do not have one and that's + + + align:start position:0% +force but do not have one and that's +about six million in that picture there + + align:start position:0% +about six million in that picture there + + + align:start position:0% +about six million in that picture there +okay so when you hear the employment or + + align:start position:0% +okay so when you hear the employment or + + + align:start position:0% +okay so when you hear the employment or +the employment rate ER you're really + + align:start position:0% +the employment rate ER you're really + + + align:start position:0% +the employment rate ER you're really +talking about these people here and when + + align:start position:0% +talking about these people here and when + + + align:start position:0% +talking about these people here and when +you talk here about unemployment rate is + + align:start position:0% +you talk here about unemployment rate is + + + align:start position:0% +you talk here about unemployment rate is +these people not divid over total + + align:start position:0% +these people not divid over total + + + align:start position:0% +these people not divid over total +population but it's these people divided + + align:start position:0% +population but it's these people divided + + + align:start position:0% +population but it's these people divided +by the civilian labor force okay so + + align:start position:0% +by the civilian labor force okay so + + + align:start position:0% +by the civilian labor force okay so +that's a picture the + + align:start position:0% +that's a picture the + + + align:start position:0% +that's a picture the +yes the most recent numbers we have + + align:start position:0% +yes the most recent numbers we have + + + align:start position:0% +yes the most recent numbers we have +about that kind of a statistics is er + + align:start position:0% +about that kind of a statistics is er + + + align:start position:0% +about that kind of a statistics is er +here you have them I mean the + + align:start position:0% +here you have them I mean the + + + align:start position:0% +here you have them I mean the +unemployment rate in the US today is + + align:start position:0% +unemployment rate in the US today is + + + align:start position:0% +unemployment rate in the US today is +about 3.4% that's very low I'll show you + + align:start position:0% +about 3.4% that's very low I'll show you + + + align:start position:0% +about 3.4% that's very low I'll show you +historical data in a minute and I have + + align:start position:0% +historical data in a minute and I have + + + align:start position:0% +historical data in a minute and I have +shown you historical data in the recent + + align:start position:0% +shown you historical data in the recent + + + align:start position:0% +shown you historical data in the recent +past H but this number is very very low + + align:start position:0% +past H but this number is very very low + + + align:start position:0% +past H but this number is very very low +uh the change in that employment level + + align:start position:0% +uh the change in that employment level + + + align:start position:0% +uh the change in that employment level +in in this is for January was a + + align:start position:0% +in in this is for January was a + + + align:start position:0% +in in this is for January was a +reduction this is this is not rate this + + align:start position:0% +reduction this is this is not rate this + + + align:start position:0% +reduction this is this is not rate this +number of people that are that that wear + + align:start position:0% +number of people that are that that wear + + + align:start position:0% +number of people that are that that wear +no it's not number of people that were + + align:start position:0% +no it's not number of people that were + + + align:start position:0% +no it's not number of people that were +unemployed that are no longer so you + + align:start position:0% +unemployed that are no longer so you + + + align:start position:0% +unemployed that are no longer so you +look at the total stock of unemployed in + + align:start position:0% +look at the total stock of unemployed in + + + align:start position:0% +look at the total stock of unemployed in +December and then you look at the total + + align:start position:0% +December and then you look at the total + + + align:start position:0% +December and then you look at the total +stock of unemployed in January 2023 the + + align:start position:0% +stock of unemployed in January 2023 the + + + align:start position:0% +stock of unemployed in January 2023 the +difference between these two is 28,000 + + align:start position:0% +difference between these two is 28,000 + + + align:start position:0% +difference between these two is 28,000 +workers so 28,000 less workers are in + + align:start position:0% +workers so 28,000 less workers are in + + + align:start position:0% +workers so 28,000 less workers are in +the employment + + align:start position:0% +the employment + + + align:start position:0% +the employment +pool now notice that how this number is + + align:start position:0% +pool now notice that how this number is + + + align:start position:0% +pool now notice that how this number is +made it's it's not it's not that that + + align:start position:0% +made it's it's not it's not that that + + + align:start position:0% +made it's it's not it's not that that +you know 25 28,000 people just gain a + + align:start position:0% +you know 25 28,000 people just gain a + + + align:start position:0% +you know 25 28,000 people just gain a +job that's not what happened what + + align:start position:0% +job that's not what happened what + + + align:start position:0% +job that's not what happened what +happens is first employment 895,000 + + align:start position:0% +happens is first employment 895,000 + + + align:start position:0% +happens is first employment 895,000 +94,000 people got a job much bigger + + align:start position:0% +94,000 people got a job much bigger + + + align:start position:0% +94,000 people got a job much bigger +number but also the civilian label Force + + align:start position:0% +number but also the civilian label Force + + + align:start position:0% +number but also the civilian label Force +went up by 866 + + align:start position:0% + + + + align:start position:0% + +um thousand people okay so if you go + + align:start position:0% +um thousand people okay so if you go + + + align:start position:0% +um thousand people okay so if you go +back to this picture what you have in in + + align:start position:0% +back to this picture what you have in in + + + align:start position:0% +back to this picture what you have in in +January or the numbers reported in + + align:start position:0% +January or the numbers reported in + + + align:start position:0% +January or the numbers reported in +January I do not know which month they + + align:start position:0% +January I do not know which month they + + + align:start position:0% +January I do not know which month they +correspond to exactly is that yes this + + align:start position:0% +correspond to exactly is that yes this + + + align:start position:0% +correspond to exactly is that yes this +this decline but that decline was made + + align:start position:0% +this decline but that decline was made + + + align:start position:0% +this decline but that decline was made +of a big increase in + + align:start position:0% +of a big increase in + + + align:start position:0% +of a big increase in +employment together with a big increase + + align:start position:0% +employment together with a big increase + + + align:start position:0% +employment together with a big increase +in the civan labor force okay so that + + align:start position:0% +in the civan labor force okay so that + + + align:start position:0% +in the civan labor force okay so that +must have be mostly movement out of the + + align:start position:0% +must have be mostly movement out of the + + + align:start position:0% +must have be mostly movement out of the +labor force and probably but had + + align:start position:0% +labor force and probably but had + + + align:start position:0% +labor force and probably but had +something to well I'm not going to get + + align:start position:0% +something to well I'm not going to get + + + align:start position:0% +something to well I'm not going to get +into that here + + align:start position:0% +into that here + + + align:start position:0% +into that here +but um all these numbers are seasonally + + align:start position:0% +but um all these numbers are seasonally + + + align:start position:0% +but um all these numbers are seasonally +adjusted so they're corrected relative + + align:start position:0% +adjusted so they're corrected relative + + + align:start position:0% +adjusted so they're corrected relative +to what happens normally in januaries + + align:start position:0% +to what happens normally in januaries + + + align:start position:0% +to what happens normally in januaries +and so on and covid and weather can sort + + align:start position:0% +and so on and covid and weather can sort + + + align:start position:0% +and so on and covid and weather can sort +of derail a lot what happens in January + + align:start position:0% +of derail a lot what happens in January + + + align:start position:0% +of derail a lot what happens in January +February numbers tend to be very noisy + + align:start position:0% +February numbers tend to be very noisy + + + align:start position:0% +February numbers tend to be very noisy +since Co they have been very noisy + + align:start position:0% +since Co they have been very noisy + + + align:start position:0% +since Co they have been very noisy +because the seasonal adjustments are + + align:start position:0% +because the seasonal adjustments are + + + align:start position:0% +because the seasonal adjustments are +different and and also weather matters a + + align:start position:0% +different and and also weather matters a + + + align:start position:0% +different and and also weather matters a +lot in January February and so on so you + + align:start position:0% +lot in January February and so on so you + + + align:start position:0% +lot in January February and so on so you +can get pretty large fluctuations which + + align:start position:0% +can get pretty large fluctuations which + + + align:start position:0% +can get pretty large fluctuations which +are really not that interesting to micro + + align:start position:0% +are really not that interesting to micro + + + align:start position:0% +are really not that interesting to micro +economies but anyways those are the + + align:start position:0% +economies but anyways those are the + + + align:start position:0% +economies but anyways those are the +numbers you look at the civilian label + + align:start position:0% +numbers you look at the civilian label + + + align:start position:0% +numbers you look at the civilian label +for participation then it was about 62% + + align:start position:0% +for participation then it was about 62% + + + align:start position:0% +for participation then it was about 62% +62 and a half% and the employment + + align:start position:0% +62 and a half% and the employment + + + align:start position:0% +62 and a half% and the employment +population ratio is of the order of 60% + + align:start position:0% +population ratio is of the order of 60% + + + align:start position:0% +population ratio is of the order of 60% +okay so employment population ratio is + + align:start position:0% +okay so employment population ratio is + + + align:start position:0% +okay so employment population ratio is +is just this H divided by total + + align:start position:0% + + + + align:start position:0% + +population + + align:start position:0% +population + + + align:start position:0% +population +um those are the averages the number of + + align:start position:0% +um those are the averages the number of + + + align:start position:0% +um those are the averages the number of +unemployed in 202 to about 6 million + + align:start position:0% +unemployed in 202 to about 6 million + + + align:start position:0% +unemployed in 202 to about 6 million +people that's that's unemploy okay so + + align:start position:0% +people that's that's unemploy okay so + + + align:start position:0% +people that's that's unemploy okay so +there you have the unemployment rate you + + align:start position:0% +there you have the unemployment rate you + + + align:start position:0% +there you have the unemployment rate you +know and it moves as you would expect it + + align:start position:0% +know and it moves as you would expect it + + + align:start position:0% +know and it moves as you would expect it +it typically goes up in + + align:start position:0% +it typically goes up in + + + align:start position:0% +it typically goes up in +recessions ER the last sort of large + + align:start position:0% +recessions ER the last sort of large + + + align:start position:0% +recessions ER the last sort of large +recession we had big + + align:start position:0% +recession we had big + + + align:start position:0% +recession we had big +swings one thing that was interesting + + align:start position:0% +swings one thing that was interesting + + + align:start position:0% +swings one thing that was interesting +and we couldn't quite understand what + + align:start position:0% +and we couldn't quite understand what + + + align:start position:0% +and we couldn't quite understand what +was going on is as you notice right + + align:start position:0% +was going on is as you notice right + + + align:start position:0% +was going on is as you notice right +before covid that employment rate had + + align:start position:0% +before covid that employment rate had + + + align:start position:0% +before covid that employment rate had +already declined to very low levels and + + align:start position:0% +already declined to very low levels and + + + align:start position:0% +already declined to very low levels and +so people were wondering whether + + align:start position:0% +so people were wondering whether + + + align:start position:0% +so people were wondering whether +something we're going to talk about + + align:start position:0% +something we're going to talk about + + + align:start position:0% +something we're going to talk about +later in this this lecture whe the + + align:start position:0% +later in this this lecture whe the + + + align:start position:0% +later in this this lecture whe the +natural rate of unemployment had changed + + align:start position:0% +natural rate of unemployment had changed + + + align:start position:0% +natural rate of unemployment had changed +for some + + align:start position:0% +for some + + + align:start position:0% +for some +reason we'll come back to that then we + + align:start position:0% +reason we'll come back to that then we + + + align:start position:0% +reason we'll come back to that then we +got we got Co obviously a very + + align:start position:0% +got we got Co obviously a very + + + align:start position:0% +got we got Co obviously a very +recessionary shock initially massive + + align:start position:0% +recessionary shock initially massive + + + align:start position:0% +recessionary shock initially massive +unemployment and so on but then it came + + align:start position:0% +unemployment and so on but then it came + + + align:start position:0% +unemployment and so on but then it came +back very quickly and today we have + + align:start position:0% +back very quickly and today we have + + + align:start position:0% +back very quickly and today we have +record low levels of unemployment we + + align:start position:0% +record low levels of unemployment we + + + align:start position:0% +record low levels of unemployment we +haven't seen numbers like this since you + + align:start position:0% +haven't seen numbers like this since you + + + align:start position:0% +haven't seen numbers like this since you +know the 60s really very low levels of + + align:start position:0% +know the 60s really very low levels of + + + align:start position:0% +know the 60s really very low levels of +unemployment so when when one of the + + align:start position:0% +unemployment so when when one of the + + + align:start position:0% +unemployment so when when one of the +things that that when you hear the fomc + + align:start position:0% +things that that when you hear the fomc + + + align:start position:0% +things that that when you hear the fomc +members talking about the labor markets + + align:start position:0% +members talking about the labor markets + + + align:start position:0% +members talking about the labor markets +being very tight well one of the things + + align:start position:0% +being very tight well one of the things + + + align:start position:0% +being very tight well one of the things +they're looking at is this one there are + + align:start position:0% +they're looking at is this one there are + + + align:start position:0% +they're looking at is this one there are +other statistics I'll show you but but + + align:start position:0% +other statistics I'll show you but but + + + align:start position:0% +other statistics I'll show you but but +but this is one of them unemployment + + align:start position:0% +but this is one of them unemployment + + + align:start position:0% +but this is one of them unemployment +rate is really really + + align:start position:0% + + + + align:start position:0% + +low sometimes again especially postco + + align:start position:0% +low sometimes again especially postco + + + align:start position:0% +low sometimes again especially postco +because of movements in and out of the + + align:start position:0% +because of movements in and out of the + + + align:start position:0% +because of movements in and out of the +labor + + align:start position:0% +labor + + + align:start position:0% +labor +force ER the unemployment rate is not + + align:start position:0% +force ER the unemployment rate is not + + + align:start position:0% +force ER the unemployment rate is not +such a great statistic not as reliable + + align:start position:0% +such a great statistic not as reliable + + + align:start position:0% +such a great statistic not as reliable +because many people left the labor force + + align:start position:0% +because many people left the labor force + + + align:start position:0% +because many people left the labor force +so people look a lot at the employment + + align:start position:0% +so people look a lot at the employment + + + align:start position:0% +so people look a lot at the employment +rate + + align:start position:0% +rate + + + align:start position:0% +rate +uh which is this is this is um this is + + align:start position:0% +uh which is this is this is um this is + + + align:start position:0% +uh which is this is this is um this is +not employment population RTI is + + align:start position:0% +not employment population RTI is + + + align:start position:0% +not employment population RTI is +employment rate so employed + + align:start position:0% +employment rate so employed + + + align:start position:0% +employment rate so employed +over the non- + + align:start position:0% +over the non- + + + align:start position:0% +over the non- +civilian + + align:start position:0% + + + + align:start position:0% + +population and that number you can see + + align:start position:0% +population and that number you can see + + + align:start position:0% +population and that number you can see +we had discussed this before was + + align:start position:0% +we had discussed this before was + + + align:start position:0% +we had discussed this before was +trending up here because of increasing + + align:start position:0% +trending up here because of increasing + + + align:start position:0% +trending up here because of increasing +the labor participation of women then it + + align:start position:0% +the labor participation of women then it + + + align:start position:0% +the labor participation of women then it +came down had a lot to do with the + + align:start position:0% +came down had a lot to do with the + + + align:start position:0% +came down had a lot to do with the +students and things like that + + align:start position:0% +students and things like that + + + align:start position:0% +students and things like that +systematically but then it was climbing + + align:start position:0% +systematically but then it was climbing + + + align:start position:0% +systematically but then it was climbing +up enormously collaps during covid + + align:start position:0% +up enormously collaps during covid + + + align:start position:0% +up enormously collaps during covid +that's mostly unemployment and and and + + align:start position:0% +that's mostly unemployment and and and + + + align:start position:0% +that's mostly unemployment and and and +and and people out of the labor + + align:start position:0% +and and people out of the labor + + + align:start position:0% +and and people out of the labor +force H and then recovery but the + + align:start position:0% +force H and then recovery but the + + + align:start position:0% +force H and then recovery but the +recovery has not pick up to back to the + + align:start position:0% +recovery has not pick up to back to the + + + align:start position:0% +recovery has not pick up to back to the +trend see we are back to sort the more + + align:start position:0% +trend see we are back to sort the more + + + align:start position:0% +trend see we are back to sort the more +or less levels we had before covid but + + align:start position:0% +or less levels we had before covid but + + + align:start position:0% +or less levels we had before covid but +we're certainly off the trend and one of + + align:start position:0% +we're certainly off the trend and one of + + + align:start position:0% +we're certainly off the trend and one of +the reasons the labor markets are very + + align:start position:0% +the reasons the labor markets are very + + + align:start position:0% +the reasons the labor markets are very +tight is that is that we haven't + + align:start position:0% +tight is that is that we haven't + + + align:start position:0% +tight is that is that we haven't +recovered sort + + align:start position:0% +recovered sort + + + align:start position:0% +recovered sort +of the + + align:start position:0% +of the + + + align:start position:0% +of the +employment um rate that that we used to + + align:start position:0% +employment um rate that that we used to + + + align:start position:0% +employment um rate that that we used to +have this has to do with migration flows + + align:start position:0% +have this has to do with migration flows + + + align:start position:0% +have this has to do with migration flows +with a variety of things but that's + + align:start position:0% +with a variety of things but that's + + + align:start position:0% +with a variety of things but that's +that's the + + align:start position:0% +that's the + + + align:start position:0% +that's the +issue okay so that's that's sort of + + align:start position:0% +issue okay so that's that's sort of + + + align:start position:0% +issue okay so that's that's sort of +those are very static pictures of the + + align:start position:0% +those are very static pictures of the + + + align:start position:0% +those are very static pictures of the +labor market what is the stock of + + align:start position:0% +labor market what is the stock of + + + align:start position:0% +labor market what is the stock of +unemployment at one point what is the + + align:start position:0% +unemployment at one point what is the + + + align:start position:0% +unemployment at one point what is the +unemployment rate and so on so forth but + + align:start position:0% +unemployment rate and so on so forth but + + + align:start position:0% +unemployment rate and so on so forth but +the truth is that that labor markets are + + align:start position:0% +the truth is that that labor markets are + + + align:start position:0% +the truth is that that labor markets are +very + + align:start position:0% +very + + + align:start position:0% +very +Dynamic especially in an economic like + + align:start position:0% +Dynamic especially in an economic like + + + align:start position:0% +Dynamic especially in an economic like +the US the flows are very large so what + + align:start position:0% +the US the flows are very large so what + + + align:start position:0% +the US the flows are very large so what +I have there and I don't know for which + + align:start position:0% +I have there and I don't know for which + + + align:start position:0% +I have there and I don't know for which +date this is in the book but the + + align:start position:0% +date this is in the book but the + + + align:start position:0% +date this is in the book but the +pictures look more or less the same for + + align:start position:0% +pictures look more or less the same for + + + align:start position:0% +pictures look more or less the same for +the point I want to make this is monthly + + align:start position:0% +the point I want to make this is monthly + + + align:start position:0% +the point I want to make this is monthly +label FL flows and this happen in some + + align:start position:0% +label FL flows and this happen in some + + + align:start position:0% +label FL flows and this happen in some +month I don't care to 2018 at some point + + align:start position:0% +month I don't care to 2018 at some point + + + align:start position:0% +month I don't care to 2018 at some point +look at what happened there you have + + align:start position:0% +look at what happened there you have + + + align:start position:0% +look at what happened there you have +this we were talking about the stocks + + align:start position:0% +this we were talking about the stocks + + + align:start position:0% +this we were talking about the stocks +recently so employment in that month was + + align:start position:0% +recently so employment in that month was + + + align:start position:0% +recently so employment in that month was +of the order of $132 million dollar 132 + + align:start position:0% +of the order of $132 million dollar 132 + + + align:start position:0% +of the order of $132 million dollar 132 +million people okay out of the level + + align:start position:0% +million people okay out of the level + + + align:start position:0% +million people okay out of the level +Force about 7 9 million people + + align:start position:0% +Force about 7 9 million people + + + align:start position:0% +Force about 7 9 million people +unemployed about 8.6 million that's + + align:start position:0% +unemployed about 8.6 million that's + + + align:start position:0% +unemployed about 8.6 million that's +those were the stocks those were the + + align:start position:0% +those were the stocks those were the + + + align:start position:0% +those were the stocks those were the +type of numbers I was showing you before + + align:start position:0% +type of numbers I was showing you before + + + align:start position:0% +type of numbers I was showing you before +okay but look at this arrows these are + + align:start position:0% +okay but look at this arrows these are + + + align:start position:0% +okay but look at this arrows these are +flows so in every single month you see + + align:start position:0% +flows so in every single month you see + + + align:start position:0% +flows so in every single month you see +in the US about 3 million people that + + align:start position:0% +in the US about 3 million people that + + + align:start position:0% +in the US about 3 million people that +move from one job to another so + + align:start position:0% +move from one job to another so + + + align:start position:0% +move from one job to another so +employment to + + align:start position:0% +employment to + + + align:start position:0% +employment to +employment you see about 1.8 million + + align:start position:0% +employment you see about 1.8 million + + + align:start position:0% +employment you see about 1.8 million +that move from employment to + + align:start position:0% +that move from employment to + + + align:start position:0% +that move from employment to +unemployment and about 2 million people + + align:start position:0% +unemployment and about 2 million people + + + align:start position:0% +unemployment and about 2 million people +that move from unemployment to + + align:start position:0% +that move from unemployment to + + + align:start position:0% +that move from unemployment to +employment large + + align:start position:0% +employment large + + + align:start position:0% +employment large +flows not only so not everything goes + + align:start position:0% +flows not only so not everything goes + + + align:start position:0% +flows not only so not everything goes +through Unemployment to employment there + + align:start position:0% +through Unemployment to employment there + + + align:start position:0% +through Unemployment to employment there +are people are also moving out of the + + align:start position:0% +are people are also moving out of the + + + align:start position:0% +are people are also moving out of the +labor force and into a labor force into + + align:start position:0% +labor force and into a labor force into + + + align:start position:0% +labor force and into a labor force into +an employment into employment here in + + align:start position:0% +an employment into employment here in + + + align:start position:0% +an employment into employment here in +this particular case out the flow out of + + align:start position:0% +this particular case out the flow out of + + + align:start position:0% +this particular case out the flow out of +the labor force into employment is 3.4 + + align:start position:0% +the labor force into employment is 3.4 + + + align:start position:0% +the labor force into employment is 3.4 +million flows from employment without + + align:start position:0% +million flows from employment without + + + align:start position:0% +million flows from employment without +going through Unemployment to out of the + + align:start position:0% +going through Unemployment to out of the + + + align:start position:0% +going through Unemployment to out of the +labor force 3.7 + + align:start position:0% +labor force 3.7 + + + align:start position:0% +labor force 3.7 +million okay during covid there was a + + align:start position:0% +million okay during covid there was a + + + align:start position:0% +million okay during covid there was a +this must have been a very thick Arrow + + align:start position:0% +this must have been a very thick Arrow + + + align:start position:0% +this must have been a very thick Arrow +lots of people move out from employment + + align:start position:0% +lots of people move out from employment + + + align:start position:0% +lots of people move out from employment +to out of the labor force okay and and + + align:start position:0% +to out of the labor force okay and and + + + align:start position:0% +to out of the labor force okay and and +one of the problems the economy has had + + align:start position:0% +one of the problems the economy has had + + + align:start position:0% +one of the problems the economy has had +in the recovery on the on the labor + + align:start position:0% +in the recovery on the on the labor + + + align:start position:0% +in the recovery on the on the labor +market side is that this Arrow hasn't + + align:start position:0% +market side is that this Arrow hasn't + + + align:start position:0% +market side is that this Arrow hasn't +been as strong as we would wanted okay + + align:start position:0% +been as strong as we would wanted okay + + + align:start position:0% +been as strong as we would wanted okay +this Arrow or this arrow for as a matter + + align:start position:0% +this Arrow or this arrow for as a matter + + + align:start position:0% +this Arrow or this arrow for as a matter +of fact people coming coming out of the + + align:start position:0% +of fact people coming coming out of the + + + align:start position:0% +of fact people coming coming out of the +labor force into unemployment that's + + align:start position:0% +labor force into unemployment that's + + + align:start position:0% +labor force into unemployment that's +also a big flow sometimes people are not + + align:start position:0% +also a big flow sometimes people are not + + + align:start position:0% +also a big flow sometimes people are not +working and then they side that you know + + align:start position:0% +working and then they side that you know + + + align:start position:0% +working and then they side that you know +they run out of an employment insurance + + align:start position:0% +they run out of an employment insurance + + + align:start position:0% +they run out of an employment insurance +or something like that and so they de + + align:start position:0% +or something like that and so they de + + + align:start position:0% +or something like that and so they de +start to start looking you know and they + + align:start position:0% +start to start looking you know and they + + + align:start position:0% +start to start looking you know and they +move + + align:start position:0% +move + + + align:start position:0% +move +into unemployment here okay or they run + + align:start position:0% +into unemployment here okay or they run + + + align:start position:0% +into unemployment here okay or they run +out of savings and and they have to come + + align:start position:0% +out of savings and and they have to come + + + align:start position:0% +out of savings and and they have to come +back and they may not find a job + + align:start position:0% +back and they may not find a job + + + align:start position:0% +back and they may not find a job +initially they have to go through + + align:start position:0% +initially they have to go through + + + align:start position:0% +initially they have to go through +employment okay so point is that these + + align:start position:0% +employment okay so point is that these + + + align:start position:0% +employment okay so point is that these +flows are very large and and uh and + + align:start position:0% +flows are very large and and uh and + + + align:start position:0% +flows are very large and and uh and +these flows matter a + + align:start position:0% +these flows matter a + + + align:start position:0% +these flows matter a +lot ER for for the kind of things we + + align:start position:0% +lot ER for for the kind of things we + + + align:start position:0% +lot ER for for the kind of things we +want to talk about in in this course + + align:start position:0% +want to talk about in in this course + + + align:start position:0% +want to talk about in in this course +look at what we have here H the red line + + align:start position:0% +look at what we have here H the red line + + + align:start position:0% +look at what we have here H the red line +is the unemployment rate and is measured + + align:start position:0% +is the unemployment rate and is measured + + + align:start position:0% +is the unemployment rate and is measured +on the left axis and what we have here + + align:start position:0% +on the left axis and what we have here + + + align:start position:0% +on the left axis and what we have here +in the blue line is measured in an + + align:start position:0% +in the blue line is measured in an + + + align:start position:0% +in the blue line is measured in an +inverse scale look at this this goes up + + align:start position:0% +inverse scale look at this this goes up + + + align:start position:0% +inverse scale look at this this goes up +as you go down is is the percentage of + + align:start position:0% +as you go down is is the percentage of + + + align:start position:0% +as you go down is is the percentage of +employe unemployed workers becoming + + align:start position:0% +employe unemployed workers becoming + + + align:start position:0% +employe unemployed workers becoming +employed okay so it's a job finding rate + + align:start position:0% +employed okay so it's a job finding rate + + + align:start position:0% +employed okay so it's a job finding rate +from unemployment so you have unemployed + + align:start position:0% +from unemployment so you have unemployed + + + align:start position:0% +from unemployment so you have unemployed +people and they will be finding jobs + + align:start position:0% +people and they will be finding jobs + + + align:start position:0% +people and they will be finding jobs +they're looking for jobs and they will + + align:start position:0% +they're looking for jobs and they will + + + align:start position:0% +they're looking for jobs and they will +be finding jobs this number here here + + align:start position:0% +be finding jobs this number here here + + + align:start position:0% +be finding jobs this number here here +this blue line here shows you H the + + align:start position:0% +this blue line here shows you H the + + + align:start position:0% +this blue line here shows you H the +likelihood that they find a job in + + align:start position:0% +likelihood that they find a job in + + + align:start position:0% +likelihood that they find a job in +inverted scale okay so what do you what + + align:start position:0% +inverted scale okay so what do you what + + + align:start position:0% +inverted scale okay so what do you what +correlation do you notice + + align:start position:0% + + + + align:start position:0% + +there very + + align:start position:0% +there very + + + align:start position:0% +there very +tight yeah the percent of people um that + + align:start position:0% +tight yeah the percent of people um that + + + align:start position:0% +tight yeah the percent of people um that +get a job each month is smaller there's + + align:start position:0% +get a job each month is smaller there's + + + align:start position:0% +get a job each month is smaller there's +more people without a job + + align:start position:0% +more people without a job + + + align:start position:0% +more people without a job +exactly that means when the employment + + align:start position:0% +exactly that means when the employment + + + align:start position:0% +exactly that means when the employment +rate is + + align:start position:0% +rate is + + + align:start position:0% +rate is +high it is harder for an employed + + align:start position:0% +high it is harder for an employed + + + align:start position:0% +high it is harder for an employed +workers to find a + + align:start position:0% +workers to find a + + + align:start position:0% +workers to find a +job or another way of an direct + + align:start position:0% +job or another way of an direct + + + align:start position:0% +job or another way of an direct +implication of that is that typical + + align:start position:0% +implication of that is that typical + + + align:start position:0% +implication of that is that typical +unemployed worker will spend more time + + align:start position:0% +unemployed worker will spend more time + + + align:start position:0% +unemployed worker will spend more time +in unemployment because they want to be + + align:start position:0% +in unemployment because they want to be + + + align:start position:0% +in unemployment because they want to be +looking for jobs and it's more it's + + align:start position:0% +looking for jobs and it's more it's + + + align:start position:0% +looking for jobs and it's more it's +harder to get a job so you're going to + + align:start position:0% +harder to get a job so you're going to + + + align:start position:0% +harder to get a job so you're going to +be looking for a job for a longer period + + align:start position:0% +be looking for a job for a longer period + + + align:start position:0% +be looking for a job for a longer period +of time why are we talking about these + + align:start position:0% +of time why are we talking about these + + + align:start position:0% +of time why are we talking about these +things well because of this type of er + + align:start position:0% +things well because of this type of er + + + align:start position:0% +things well because of this type of er +reasons well this this means that when + + align:start position:0% +reasons well this this means that when + + + align:start position:0% +reasons well this this means that when +an employment is high workers are worse + + align:start position:0% +an employment is high workers are worse + + + align:start position:0% +an employment is high workers are worse +off in at least two ways and there are + + align:start position:0% +off in at least two ways and there are + + + align:start position:0% +off in at least two ways and there are +two ways that are going to be important + + align:start position:0% +two ways that are going to be important + + + align:start position:0% +two ways that are going to be important +for what I'll say next one is that the + + align:start position:0% +for what I'll say next one is that the + + + align:start position:0% +for what I'll say next one is that the +employed workers face a higher + + align:start position:0% +employed workers face a higher + + + align:start position:0% +employed workers face a higher +probability of losing a job that's what + + align:start position:0% +probability of losing a job that's what + + + align:start position:0% +probability of losing a job that's what +happens when an employment is the reason + + align:start position:0% +happens when an employment is the reason + + + align:start position:0% +happens when an employment is the reason +an employment gets to be high is because + + align:start position:0% +an employment gets to be high is because + + + align:start position:0% +an employment gets to be high is because +firms are firing workers and so on so + + align:start position:0% +firms are firing workers and so on so + + + align:start position:0% +firms are firing workers and so on so +forth no and + + align:start position:0% +forth no and + + + align:start position:0% +forth no and +so so so when an employment is high the + + align:start position:0% +so so so when an employment is high the + + + align:start position:0% +so so so when an employment is high the +first thing the workers know is that + + align:start position:0% +first thing the workers know is that + + + align:start position:0% +first thing the workers know is that +it's very likely lose their job more + + align:start position:0% +it's very likely lose their job more + + + align:start position:0% +it's very likely lose their job more +likely that they lose their + + align:start position:0% +likely that they lose their + + + align:start position:0% +likely that they lose their +job but the second Channel which is what + + align:start position:0% +job but the second Channel which is what + + + align:start position:0% +job but the second Channel which is what +this picture highlights here is that if + + align:start position:0% +this picture highlights here is that if + + + align:start position:0% +this picture highlights here is that if +you fall unemployment it's going to take + + align:start position:0% +you fall unemployment it's going to take + + + align:start position:0% +you fall unemployment it's going to take +a it's going to be a lot harder to get + + align:start position:0% +a it's going to be a lot harder to get + + + align:start position:0% +a it's going to be a lot harder to get +out of an employment okay so when an + + align:start position:0% +out of an employment okay so when an + + + align:start position:0% +out of an employment okay so when an +employment is is high is scary for + + align:start position:0% +employment is is high is scary for + + + align:start position:0% +employment is is high is scary for +workers for two reasons once you're more + + align:start position:0% +workers for two reasons once you're more + + + align:start position:0% +workers for two reasons once you're more +likely to lose a job because you're + + align:start position:0% +likely to lose a job because you're + + + align:start position:0% +likely to lose a job because you're +capturing recessionary conditions and so + + align:start position:0% +capturing recessionary conditions and so + + + align:start position:0% +capturing recessionary conditions and so +on in the economy but second if you end + + align:start position:0% +on in the economy but second if you end + + + align:start position:0% +on in the economy but second if you end +up in unemployment it's going to be hard + + align:start position:0% +up in unemployment it's going to be hard + + + align:start position:0% +up in unemployment it's going to be hard +to get out of + + align:start position:0% +to get out of + + + align:start position:0% +to get out of +it okay + + align:start position:0% +it okay + + + align:start position:0% +it okay +and and later on this unemployment rate + + align:start position:0% +and and later on this unemployment rate + + + align:start position:0% +and and later on this unemployment rate +is going to show up in wage bargaining + + align:start position:0% +is going to show up in wage bargaining + + + align:start position:0% +is going to show up in wage bargaining +and the main reason is going to show up + + align:start position:0% +and the main reason is going to show up + + + align:start position:0% +and the main reason is going to show up +is of this + + align:start position:0% +is of this + + + align:start position:0% +is of this +kind and also think about the other side + + align:start position:0% +kind and also think about the other side + + + align:start position:0% +kind and also think about the other side +when there's bargaining there's two in a + + align:start position:0% +when there's bargaining there's two in a + + + align:start position:0% +when there's bargaining there's two in a +bargain you know there's going to be + + align:start position:0% +bargain you know there's going to be + + + align:start position:0% +bargain you know there's going to be +firm and workers from The Firm point of + + align:start position:0% +firm and workers from The Firm point of + + + align:start position:0% +firm and workers from The Firm point of +view if there's a lot of unemployment do + + align:start position:0% +view if there's a lot of unemployment do + + + align:start position:0% +view if there's a lot of unemployment do +you think it's hard or or or or easy to + + align:start position:0% +you think it's hard or or or or easy to + + + align:start position:0% +you think it's hard or or or or easy to +find a worker to replace a worker that + + align:start position:0% +find a worker to replace a worker that + + + align:start position:0% +find a worker to replace a worker that +decides to leave for whatever reason + + align:start position:0% +decides to leave for whatever reason + + + align:start position:0% +decides to leave for whatever reason +easy you have lots of people to choose + + align:start position:0% +easy you have lots of people to choose + + + align:start position:0% +easy you have lots of people to choose +from so it becomes easy so an employment + + align:start position:0% +from so it becomes easy so an employment + + + align:start position:0% +from so it becomes easy so an employment +is high workers are more scar if they + + align:start position:0% +is high workers are more scar if they + + + align:start position:0% +is high workers are more scar if they +get out is scar of losing the job if + + align:start position:0% +get out is scar of losing the job if + + + align:start position:0% +get out is scar of losing the job if +they get out is is is hard to get a job + + align:start position:0% +they get out is is is hard to get a job + + + align:start position:0% +they get out is is is hard to get a job +and on the other side the firms for the + + align:start position:0% +and on the other side the firms for the + + + align:start position:0% +and on the other side the firms for the +firms it's not that scary to lose a + + align:start position:0% +firms it's not that scary to lose a + + + align:start position:0% +firms it's not that scary to lose a +worker because it's fairly easy to + + align:start position:0% +worker because it's fairly easy to + + + align:start position:0% +worker because it's fairly easy to +replace that worker today firms are very + + align:start position:0% +replace that worker today firms are very + + + align:start position:0% +replace that worker today firms are very +worried about losing their workers in + + align:start position:0% +worried about losing their workers in + + + align:start position:0% +worried about losing their workers in +some sectors no in some sectors getting + + align:start position:0% +some sectors no in some sectors getting + + + align:start position:0% +some sectors no in some sectors getting +rid of workers but but if you run a + + align:start position:0% +rid of workers but but if you run a + + + align:start position:0% +rid of workers but but if you run a +restaurant you're very scared of losing + + align:start position:0% +restaurant you're very scared of losing + + + align:start position:0% +restaurant you're very scared of losing +your your your workers no because it's + + align:start position:0% +your your your workers no because it's + + + align:start position:0% +your your your workers no because it's +going to be very difficult to find a + + align:start position:0% +going to be very difficult to find a + + + align:start position:0% +going to be very difficult to find a +replacement for that worker surprise + + align:start position:0% +replacement for that worker surprise + + + align:start position:0% +replacement for that worker surprise +surprise wages in that industry are + + align:start position:0% +surprise wages in that industry are + + + align:start position:0% +surprise wages in that industry are +going up a lot + + align:start position:0% +going up a lot + + + align:start position:0% +going up a lot +okay we're going to get there so that's + + align:start position:0% +okay we're going to get there so that's + + + align:start position:0% +okay we're going to get there so that's +what comes next wage determination look + + align:start position:0% +what comes next wage determination look + + + align:start position:0% +what comes next wage determination look +at what I'm what I'm trying to build + + align:start position:0% +at what I'm what I'm trying to build + + + align:start position:0% +at what I'm what I'm trying to build +here I'm starting from telling you + + align:start position:0% +here I'm starting from telling you + + + align:start position:0% +here I'm starting from telling you +stories about the labor market what + + align:start position:0% +stories about the labor market what + + + align:start position:0% +stories about the labor market what +things are important for workers and so + + align:start position:0% +things are important for workers and so + + + align:start position:0% +things are important for workers and so +on now I'm going to get into wage + + align:start position:0% +on now I'm going to get into wage + + + align:start position:0% +on now I'm going to get into wage +determination and obviously this + + align:start position:0% +determination and obviously this + + + align:start position:0% +determination and obviously this +variables I talked about are going to be + + align:start position:0% +variables I talked about are going to be + + + align:start position:0% +variables I talked about are going to be +important in this wage determination but + + align:start position:0% +important in this wage determination but + + + align:start position:0% +important in this wage determination but +my ultimate goal is to talk about + + align:start position:0% +my ultimate goal is to talk about + + + align:start position:0% +my ultimate goal is to talk about +inflation so the next step so I'm going + + align:start position:0% +inflation so the next step so I'm going + + + align:start position:0% +inflation so the next step so I'm going +to talk about wage determination here + + align:start position:0% +to talk about wage determination here + + + align:start position:0% +to talk about wage determination here +and then we're going to talk about + + align:start position:0% +and then we're going to talk about + + + align:start position:0% +and then we're going to talk about +prices and there we're going to be one + + align:start position:0% +prices and there we're going to be one + + + align:start position:0% +prices and there we're going to be one +step closer to talking about inflation + + align:start position:0% +step closer to talking about inflation + + + align:start position:0% +step closer to talking about inflation +okay so let's go through the + + align:start position:0% +okay so let's go through the + + + align:start position:0% +okay so let's go through the +intermediate step wage + + align:start position:0% +intermediate step wage + + + align:start position:0% +intermediate step wage +determination uh so just to give you a + + align:start position:0% +determination uh so just to give you a + + + align:start position:0% +determination uh so just to give you a +little background is you know + + align:start position:0% +little background is you know + + + align:start position:0% +little background is you know +sometimes H wages are set by collective + + align:start position:0% +sometimes H wages are set by collective + + + align:start position:0% +sometimes H wages are set by collective +bargaining unions in particular now in + + align:start position:0% +bargaining unions in particular now in + + + align:start position:0% +bargaining unions in particular now in +the US unions are not a big thing they + + align:start position:0% +the US unions are not a big thing they + + + align:start position:0% +the US unions are not a big thing they +were a much bigger thing many years back + + align:start position:0% +were a much bigger thing many years back + + + align:start position:0% +were a much bigger thing many years back +they are in today um in other economies + + align:start position:0% +they are in today um in other economies + + + align:start position:0% +they are in today um in other economies +they are a big thing okay Japan + + align:start position:0% +they are a big thing okay Japan + + + align:start position:0% +they are a big thing okay Japan +Europe and the unions can happen at + + align:start position:0% +Europe and the unions can happen at + + + align:start position:0% +Europe and the unions can happen at +different levels of aggregation at the + + align:start position:0% +different levels of aggregation at the + + + align:start position:0% +different levels of aggregation at the +level of the firm at the level of the + + align:start position:0% +level of the firm at the level of the + + + align:start position:0% +level of the firm at the level of the +sector and and and and + + align:start position:0% +sector and and and and + + + align:start position:0% +sector and and and and +and you name + + align:start position:0% +and you name + + + align:start position:0% +and you name +it in general regardless of the level of + + align:start position:0% +it in general regardless of the level of + + + align:start position:0% +it in general regardless of the level of +unionization you have in a country or in + + align:start position:0% +unionization you have in a country or in + + + align:start position:0% +unionization you have in a country or in +a sector the higher the skill needed to + + align:start position:0% +a sector the higher the skill needed to + + + align:start position:0% +a sector the higher the skill needed to +do a job the more likely this the + + align:start position:0% +do a job the more likely this the + + + align:start position:0% +do a job the more likely this the +bargaining takes place between an + + align:start position:0% +bargaining takes place between an + + + align:start position:0% +bargaining takes place between an +individual between an employer and an + + align:start position:0% +individual between an employer and an + + + align:start position:0% +individual between an employer and an +individual rather than a union okay + + align:start position:0% +individual rather than a union okay + + + align:start position:0% +individual rather than a union okay +because it's sort of much more + + align:start position:0% +because it's sort of much more + + + align:start position:0% +because it's sort of much more +idiosyncratic and customized and so on + + align:start position:0% +idiosyncratic and customized and so on + + + align:start position:0% +idiosyncratic and customized and so on +but either way regardless of whether + + align:start position:0% +but either way regardless of whether + + + align:start position:0% +but either way regardless of whether +whether wages are set at a collective + + align:start position:0% +whether wages are set at a collective + + + align:start position:0% +whether wages are set at a collective +level or at an individual level the main + + align:start position:0% +level or at an individual level the main + + + align:start position:0% +level or at an individual level the main +macroeconomic + + align:start position:0% +macroeconomic + + + align:start position:0% +macroeconomic +drivers of a wages are similar across + + align:start position:0% +drivers of a wages are similar across + + + align:start position:0% +drivers of a wages are similar across +both of them of course the particulars + + align:start position:0% +both of them of course the particulars + + + align:start position:0% +both of them of course the particulars +are going to be different even the + + align:start position:0% +are going to be different even the + + + align:start position:0% +are going to be different even the +Dynamics can be different and so on but + + align:start position:0% +Dynamics can be different and so on but + + + align:start position:0% +Dynamics can be different and so on but +the big drivers the big macro drivers + + align:start position:0% +the big drivers the big macro drivers + + + align:start position:0% +the big drivers the big macro drivers +are similar regardless of the bargaining + + align:start position:0% +are similar regardless of the bargaining + + + align:start position:0% +are similar regardless of the bargaining +mold you have at the level it which + + align:start position:0% +mold you have at the level it which + + + align:start position:0% +mold you have at the level it which +happens and so on and those are the + + align:start position:0% +happens and so on and those are the + + + align:start position:0% +happens and so on and those are the +things we're going to highlight here + + align:start position:0% + + + + align:start position:0% + +so a fact of life is that workers wages + + align:start position:0% +so a fact of life is that workers wages + + + align:start position:0% +so a fact of life is that workers wages +typically exceed the reservation wage + + align:start position:0% +typically exceed the reservation wage + + + align:start position:0% +typically exceed the reservation wage +now what does it mean the reservation + + align:start position:0% +now what does it mean the reservation + + + align:start position:0% +now what does it mean the reservation +wage the reservation wage is a wage that + + align:start position:0% +wage the reservation wage is a wage that + + + align:start position:0% +wage the reservation wage is a wage that +would leave you indiff between employed + + align:start position:0% +would leave you indiff between employed + + + align:start position:0% +would leave you indiff between employed +or unemployed doesn't mean there a nice + + align:start position:0% +or unemployed doesn't mean there a nice + + + align:start position:0% +or unemployed doesn't mean there a nice +wage anything but I mean that's and + + align:start position:0% +wage anything but I mean that's and + + + align:start position:0% +wage anything but I mean that's and +certainly doesn't mean that you wouldn't + + align:start position:0% +certainly doesn't mean that you wouldn't + + + align:start position:0% +certainly doesn't mean that you wouldn't +prefer to have a higher wage but it + + align:start position:0% +prefer to have a higher wage but it + + + align:start position:0% +prefer to have a higher wage but it +tells you that look at that wage You' + + align:start position:0% +tells you that look at that wage You' + + + align:start position:0% +tells you that look at that wage You' +rather be employed than + + align:start position:0% +rather be employed than + + + align:start position:0% +rather be employed than +unemployed okay and there is a way long + + align:start position:0% +unemployed okay and there is a way long + + + align:start position:0% +unemployed okay and there is a way long +list of reasons why that ends up being + + align:start position:0% +list of reasons why that ends up being + + + align:start position:0% +list of reasons why that ends up being +the equilibrium type wage I'm not going + + align:start position:0% +the equilibrium type wage I'm not going + + + align:start position:0% +the equilibrium type wage I'm not going +to discuss them here but take it as a + + align:start position:0% +to discuss them here but take it as a + + + align:start position:0% +to discuss them here but take it as a +fact for now okay so that is workers + + align:start position:0% +fact for now okay so that is workers + + + align:start position:0% +fact for now okay so that is workers +prefer to be employed they may take the + + align:start position:0% +prefer to be employed they may take the + + + align:start position:0% +prefer to be employed they may take the +risk of becoming unemployed but they + + align:start position:0% +risk of becoming unemployed but they + + + align:start position:0% +risk of becoming unemployed but they +typically prefer to be + + align:start position:0% +typically prefer to be + + + align:start position:0% +typically prefer to be +employed + + align:start position:0% +employed + + + align:start position:0% +employed +um now wages and this is what + + align:start position:0% +um now wages and this is what + + + align:start position:0% +um now wages and this is what +becomes important for interesting for us + + align:start position:0% +becomes important for interesting for us + + + align:start position:0% +becomes important for interesting for us +in macro is the wages + + align:start position:0% +in macro is the wages + + + align:start position:0% +in macro is the wages +that are finally set depend on labor + + align:start position:0% +that are finally set depend on labor + + + align:start position:0% +that are finally set depend on labor +market conditions so very clearly the + + align:start position:0% +market conditions so very clearly the + + + align:start position:0% +market conditions so very clearly the +lower is unemployment rate the higher + + align:start position:0% +lower is unemployment rate the higher + + + align:start position:0% +lower is unemployment rate the higher +the wages will tend to be and you're + + align:start position:0% +the wages will tend to be and you're + + + align:start position:0% +the wages will tend to be and you're +seeing it now unemployment rate is very + + align:start position:0% +seeing it now unemployment rate is very + + + align:start position:0% +seeing it now unemployment rate is very +low wages are rising a lot okay and + + align:start position:0% +low wages are rising a lot okay and + + + align:start position:0% +low wages are rising a lot okay and +workers bargaining power depends want + + align:start position:0% +workers bargaining power depends want + + + align:start position:0% +workers bargaining power depends want +again there's a huge literature on these + + align:start position:0% +again there's a huge literature on these + + + align:start position:0% +again there's a huge literature on these +things I'm just compressing it + + align:start position:0% +things I'm just compressing it + + + align:start position:0% +things I'm just compressing it +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +into the bare minimums + + align:start position:0% +into the bare minimums + + + align:start position:0% +into the bare minimums +H the bargaining power of our workers + + align:start position:0% +H the bargaining power of our workers + + + align:start position:0% +H the bargaining power of our workers +are things that we already discussed + + align:start position:0% +are things that we already discussed + + + align:start position:0% +are things that we already discussed +well it depends on how costly for the + + align:start position:0% +well it depends on how costly for the + + + align:start position:0% +well it depends on how costly for the +firm to find the workers so obviously if + + align:start position:0% +firm to find the workers so obviously if + + + align:start position:0% +firm to find the workers so obviously if +an employment is very high it's very + + align:start position:0% +an employment is very high it's very + + + align:start position:0% +an employment is very high it's very +easy for firms to buy a work find a + + align:start position:0% +easy for firms to buy a work find a + + + align:start position:0% +easy for firms to buy a work find a +worker that's not good for the + + align:start position:0% +worker that's not good for the + + + align:start position:0% +worker that's not good for the +bargaining of a work if you want to + + align:start position:0% +bargaining of a work if you want to + + + align:start position:0% +bargaining of a work if you want to +bargain with your employer and there is + + align:start position:0% +bargain with your employer and there is + + + align:start position:0% +bargain with your employer and there is +lots of people like you out there ER + + align:start position:0% +lots of people like you out there ER + + + align:start position:0% +lots of people like you out there ER +you're not going to have a lot of + + align:start position:0% +you're not going to have a lot of + + + align:start position:0% +you're not going to have a lot of +bargaining power so it's unlikely that + + align:start position:0% +bargaining power so it's unlikely that + + + align:start position:0% +bargaining power so it's unlikely that +you're going to come up with a very high + + align:start position:0% +you're going to come up with a very high + + + align:start position:0% +you're going to come up with a very high +wage okay uh and it's also the other + + align:start position:0% +wage okay uh and it's also the other + + + align:start position:0% +wage okay uh and it's also the other +side of it is how hard is for workers to + + align:start position:0% +side of it is how hard is for workers to + + + align:start position:0% +side of it is how hard is for workers to +find another job if they were to leave + + align:start position:0% +find another job if they were to leave + + + align:start position:0% +find another job if they were to leave +the firms I mean if you know that there + + align:start position:0% +the firms I mean if you know that there + + + align:start position:0% +the firms I mean if you know that there +are lots of jobs like the one you + + align:start position:0% +are lots of jobs like the one you + + + align:start position:0% +are lots of jobs like the one you +currently have out there which are not + + align:start position:0% +currently have out there which are not + + + align:start position:0% +currently have out there which are not +occupied so there's empty vacant jobs + + align:start position:0% +occupied so there's empty vacant jobs + + + align:start position:0% +occupied so there's empty vacant jobs +then you probably are going to have a + + align:start position:0% +then you probably are going to have a + + + align:start position:0% +then you probably are going to have a +much stronger hand with your employer + + align:start position:0% +much stronger hand with your employer + + + align:start position:0% +much stronger hand with your employer +because you can say okay if you don't + + align:start position:0% +because you can say okay if you don't + + + align:start position:0% +because you can say okay if you don't +pay me what I want and move to the next + + align:start position:0% +pay me what I want and move to the next + + + align:start position:0% +pay me what I want and move to the next +door okay and in terms of the + + align:start position:0% +door okay and in terms of the + + + align:start position:0% +door okay and in terms of the +macroeconomic variables we care about a + + align:start position:0% +macroeconomic variables we care about a + + + align:start position:0% +macroeconomic variables we care about a +situation like that is very likely to + + align:start position:0% +situation like that is very likely to + + + align:start position:0% +situation like that is very likely to +happen when unemployment is very + + align:start position:0% +happen when unemployment is very + + + align:start position:0% +happen when unemployment is very +low okay because that means that other + + align:start position:0% +low okay because that means that other + + + align:start position:0% +low okay because that means that other +jobs are likely to be filled + + align:start position:0% +jobs are likely to be filled + + + align:start position:0% +jobs are likely to be filled +because you know there are lots of + + align:start position:0% +because you know there are lots of + + + align:start position:0% +because you know there are lots of +people looking for things that it's + + align:start position:0% +people looking for things that it's + + + align:start position:0% +people looking for things that it's +difficult for the firms to find the + + align:start position:0% +difficult for the firms to find the + + + align:start position:0% +difficult for the firms to find the +workers and therefore you're going to be + + align:start position:0% +workers and therefore you're going to be + + + align:start position:0% +workers and therefore you're going to be +a lot more attractive to that labor + + align:start position:0% +a lot more attractive to that labor + + + align:start position:0% +a lot more attractive to that labor +market so in + + align:start position:0% +market so in + + + align:start position:0% +market so in +summary at the aggregate + + align:start position:0% +summary at the aggregate + + + align:start position:0% +summary at the aggregate +level we can write a wage setting + + align:start position:0% +level we can write a wage setting + + + align:start position:0% +level we can write a wage setting +equation of this form so the wage and + + align:start position:0% +equation of this form so the wage and + + + align:start position:0% +equation of this form so the wage and +this is the nominal + + align:start position:0% +this is the nominal + + + align:start position:0% +this is the nominal +wage ER can be written as an increasing + + align:start position:0% +wage ER can be written as an increasing + + + align:start position:0% +wage ER can be written as an increasing +function of the expected price + + align:start position:0% +function of the expected price + + + align:start position:0% +function of the expected price +price meaning wages are not set in most + + align:start position:0% +price meaning wages are not set in most + + + align:start position:0% +price meaning wages are not set in most +professions they're not set SEC second + + align:start position:0% +professions they're not set SEC second + + + align:start position:0% +professions they're not set SEC second +by second you set you know you bargain + + align:start position:0% +by second you set you know you bargain + + + align:start position:0% +by second you set you know you bargain +for a wage and so on and that thing + + align:start position:0% +for a wage and so on and that thing + + + align:start position:0% +for a wage and so on and that thing +sticks for a year or so at + + align:start position:0% +sticks for a year or so at + + + align:start position:0% +sticks for a year or so at +least okay well obviously if you expect + + align:start position:0% +least okay well obviously if you expect + + + align:start position:0% +least okay well obviously if you expect +if inflation is zero you know you're + + align:start position:0% +if inflation is zero you know you're + + + align:start position:0% +if inflation is zero you know you're +going to demand a wage that is more or + + align:start position:0% +going to demand a wage that is more or + + + align:start position:0% +going to demand a wage that is more or +less what you need + + align:start position:0% +less what you need + + + align:start position:0% +less what you need +today if inflation is + + align:start position:0% +today if inflation is + + + align:start position:0% +today if inflation is +10% you you say well I'm going to have + + align:start position:0% +10% you you say well I'm going to have + + + align:start position:0% +10% you you say well I'm going to have +to demand a higher wage because I have + + align:start position:0% +to demand a higher wage because I have + + + align:start position:0% +to demand a higher wage because I have +to live with this wage for a year and + + align:start position:0% +to live with this wage for a year and + + + align:start position:0% +to live with this wage for a year and +prices are going to be rising while I + + align:start position:0% +prices are going to be rising while I + + + align:start position:0% +prices are going to be rising while I +have this wage and so so if I expect lot + + align:start position:0% +have this wage and so so if I expect lot + + + align:start position:0% +have this wage and so so if I expect lot +of inflation if I expect prices to be + + align:start position:0% +of inflation if I expect prices to be + + + align:start position:0% +of inflation if I expect prices to be +high in the future then I'm going to ask + + align:start position:0% +high in the future then I'm going to ask + + + align:start position:0% +high in the future then I'm going to ask +for a higher nominal wage today because + + align:start position:0% +for a higher nominal wage today because + + + align:start position:0% +for a higher nominal wage today because +I'm going to have to leave with that + + align:start position:0% +I'm going to have to leave with that + + + align:start position:0% +I'm going to have to leave with that +wage on average for the next uh year or + + align:start position:0% +wage on average for the next uh year or + + + align:start position:0% +wage on average for the next uh year or +so okay so that's the first thing and + + align:start position:0% +so okay so that's the first thing and + + + align:start position:0% +so okay so that's the first thing and +you going to play an important role is + + align:start position:0% +you going to play an important role is + + + align:start position:0% +you going to play an important role is +that wages are increasing function on + + align:start position:0% +that wages are increasing function on + + + align:start position:0% +that wages are increasing function on +the price level workers expect they + + align:start position:0% +the price level workers expect they + + + align:start position:0% +the price level workers expect they +expect a high price level in the future + + align:start position:0% +expect a high price level in the future + + + align:start position:0% +expect a high price level in the future +or during the life of the wage contract + + align:start position:0% +or during the life of the wage contract + + + align:start position:0% +or during the life of the wage contract +then they obviously are going to demand + + align:start position:0% +then they obviously are going to demand + + + align:start position:0% +then they obviously are going to demand +a higher wage other things equal what + + align:start position:0% +a higher wage other things equal what + + + align:start position:0% +a higher wage other things equal what +are the things well the the arguments of + + align:start position:0% +are the things well the the arguments of + + + align:start position:0% +are the things well the the arguments of +this function here + + align:start position:0% +this function here + + + align:start position:0% +this function here +unemployment if an employ for any given + + align:start position:0% +unemployment if an employ for any given + + + align:start position:0% +unemployment if an employ for any given +expected price if the employment rate is + + align:start position:0% +expected price if the employment rate is + + + align:start position:0% +expected price if the employment rate is +high workers are going to demand a lower + + align:start position:0% +high workers are going to demand a lower + + + align:start position:0% +high workers are going to demand a lower +wage why is + + align:start position:0% + + + + align:start position:0% + +that because going to be um harder for + + align:start position:0% +that because going to be um harder for + + + align:start position:0% +that because going to be um harder for +them to find a job so they have less + + align:start position:0% +them to find a job so they have less + + + align:start position:0% +them to find a job so they have less +bargaining power they have less + + align:start position:0% +bargaining power they have less + + + align:start position:0% +bargaining power they have less +bargaining power exactly okay and so + + align:start position:0% +bargaining power exactly okay and so + + + align:start position:0% +bargaining power exactly okay and so +they're going to like they're going to + + align:start position:0% +they're going to like they're going to + + + align:start position:0% +they're going to like they're going to +demand a lower wage this variable Z here + + align:start position:0% +demand a lower wage this variable Z here + + + align:start position:0% +demand a lower wage this variable Z here +is a catch all variable + + align:start position:0% +is a catch all variable + + + align:start position:0% +is a catch all variable +for strength workers strengthen the + + align:start position:0% +for strength workers strengthen the + + + align:start position:0% +for strength workers strengthen the +bargaining position situation something + + align:start position:0% +bargaining position situation something + + + align:start position:0% +bargaining position situation something +like that so er for + + align:start position:0% +like that so er for + + + align:start position:0% +like that so er for +example ER this is things like H + + align:start position:0% +example ER this is things like H + + + align:start position:0% +example ER this is things like H +employment protection laws okay firing + + align:start position:0% +employment protection laws okay firing + + + align:start position:0% +employment protection laws okay firing +cost if it's difficult to fire someone + + align:start position:0% +cost if it's difficult to fire someone + + + align:start position:0% +cost if it's difficult to fire someone +the Z will tend to be high so this only + + align:start position:0% +the Z will tend to be high so this only + + + align:start position:0% +the Z will tend to be high so this only +tells you that given the level of + + align:start position:0% +tells you that given the level of + + + align:start position:0% +tells you that given the level of +unemployment if it is very hard to fire + + align:start position:0% +unemployment if it is very hard to fire + + + align:start position:0% +unemployment if it is very hard to fire +someone wages workers are going to be + + align:start position:0% +someone wages workers are going to be + + + align:start position:0% +someone wages workers are going to be +willing to they're they're very likely + + align:start position:0% +willing to they're they're very likely + + + align:start position:0% +willing to they're they're very likely +to demand a higher wage it's hard it's + + align:start position:0% +to demand a higher wage it's hard it's + + + align:start position:0% +to demand a higher wage it's hard it's +hard for you to fire me I'm going to + + align:start position:0% +hard for you to fire me I'm going to + + + align:start position:0% +hard for you to fire me I'm going to +bargain harder for my wage okay and this + + align:start position:0% +bargain harder for my wage okay and this + + + align:start position:0% +bargain harder for my wage okay and this +type of Institutions institutional + + align:start position:0% +type of Institutions institutional + + + align:start position:0% +type of Institutions institutional +factors play a huge role in Europe much + + align:start position:0% +factors play a huge role in Europe much + + + align:start position:0% +factors play a huge role in Europe much +more than in the US + + align:start position:0% +more than in the US + + + align:start position:0% +more than in the US +okay good but as a matter of a + + align:start position:0% +okay good but as a matter of a + + + align:start position:0% +okay good but as a matter of a +definition we're going to say an increas + + align:start position:0% +definition we're going to say an increas + + + align:start position:0% +definition we're going to say an increas +in Z is z is something that increases + + align:start position:0% +in Z is z is something that increases + + + align:start position:0% +in Z is z is something that increases +the bargaining power of workers okay and + + align:start position:0% +the bargaining power of workers okay and + + + align:start position:0% +the bargaining power of workers okay and +therefore for any given level of + + align:start position:0% +therefore for any given level of + + + align:start position:0% +therefore for any given level of +unemployment unexpected prices they're + + align:start position:0% +unemployment unexpected prices they're + + + align:start position:0% +unemployment unexpected prices they're +going to lead to a higher wage demand + + align:start position:0% +going to lead to a higher wage demand + + + align:start position:0% +going to lead to a higher wage demand +this is the W this is the workers demand + + align:start position:0% +this is the W this is the workers demand + + + align:start position:0% +this is the W this is the workers demand +in a wage we have to figure out what + + align:start position:0% +in a wage we have to figure out what + + + align:start position:0% +in a wage we have to figure out what +happens in equilibrium but this is what + + align:start position:0% +happens in equilibrium but this is what + + + align:start position:0% +happens in equilibrium but this is what +the workers are demanding okay + + align:start position:0% + + + + align:start position:0% + +is it clear what we have here + + align:start position:0% + + + + align:start position:0% + +good so let's now move to the other side + + align:start position:0% +good so let's now move to the other side + + + align:start position:0% +good so let's now move to the other side +okay so that's one side of the sissor we + + align:start position:0% +okay so that's one side of the sissor we + + + align:start position:0% +okay so that's one side of the sissor we +have the workers and they given certain + + align:start position:0% +have the workers and they given certain + + + align:start position:0% +have the workers and they given certain +macroeconomic conditions summarized by + + align:start position:0% +macroeconomic conditions summarized by + + + align:start position:0% +macroeconomic conditions summarized by +the unemployment rate unexpected prices + + align:start position:0% +the unemployment rate unexpected prices + + + align:start position:0% +the unemployment rate unexpected prices +they demand certain wages now we can't + + align:start position:0% +they demand certain wages now we can't + + + align:start position:0% +they demand certain wages now we can't +find the equilibrium wage until don't + + align:start position:0% +find the equilibrium wage until don't + + + align:start position:0% +find the equilibrium wage until don't +see the other side what firms are + + align:start position:0% +see the other side what firms are + + + align:start position:0% +see the other side what firms are +willing to pay and so on so we need to + + align:start position:0% +willing to pay and so on so we need to + + + align:start position:0% +willing to pay and so on so we need to +explore this other side and the starting + + align:start position:0% +explore this other side and the starting + + + align:start position:0% +explore this other side and the starting +point of that other side is the + + align:start position:0% +point of that other side is the + + + align:start position:0% +point of that other side is the +production function meaning uh you know + + align:start position:0% +production function meaning uh you know + + + align:start position:0% +production function meaning uh you know +uh firms are going to end up setting + + align:start position:0% +uh firms are going to end up setting + + + align:start position:0% +uh firms are going to end up setting +prices for goods but producing those + + align:start position:0% +prices for goods but producing those + + + align:start position:0% +prices for goods but producing those +goods will take factors of production + + align:start position:0% +goods will take factors of production + + + align:start position:0% +goods will take factors of production +they want to have to use something H to + + align:start position:0% +they want to have to use something H to + + + align:start position:0% +they want to have to use something H to +produce that and the cost of that + + align:start position:0% +produce that and the cost of that + + + align:start position:0% +produce that and the cost of that +something will determine importantly + + align:start position:0% +something will determine importantly + + + align:start position:0% +something will determine importantly +what is the price they end up + + align:start position:0% +what is the price they end up + + + align:start position:0% +what is the price they end up +charging I'm going to simplify things a + + align:start position:0% +charging I'm going to simplify things a + + + align:start position:0% +charging I'm going to simplify things a +lot here I'm going to assume the + + align:start position:0% +lot here I'm going to assume the + + + align:start position:0% +lot here I'm going to assume the +production function is first linear and + + align:start position:0% +production function is first linear and + + + align:start position:0% +production function is first linear and +linear only on labor so no other factors + + align:start position:0% +linear only on labor so no other factors + + + align:start position:0% +linear only on labor so no other factors +of production meaning this says that to + + align:start position:0% +of production meaning this says that to + + + align:start position:0% +of production meaning this says that to +produce one unit of the aggregate + + align:start position:0% +produce one unit of the aggregate + + + align:start position:0% +produce one unit of the aggregate +good ER you need + + align:start position:0% +good ER you need + + + align:start position:0% +good ER you need +well this says that if you have if you + + align:start position:0% +well this says that if you have if you + + + align:start position:0% +well this says that if you have if you +add an extra + + align:start position:0% +add an extra + + + align:start position:0% +add an extra +worker a ER to the big production + + align:start position:0% +worker a ER to the big production + + + align:start position:0% +worker a ER to the big production +function of the economy then you're + + align:start position:0% +function of the economy then you're + + + align:start position:0% +function of the economy then you're +going to get eight more units of output + + align:start position:0% +going to get eight more units of output + + + align:start position:0% +going to get eight more units of output +okay that's what this says so why is + + align:start position:0% +okay that's what this says so why is + + + align:start position:0% +okay that's what this says so why is +output the output we have been told + + align:start position:0% +output the output we have been told + + + align:start position:0% +output the output we have been told +talking about measuring the way we have + + align:start position:0% +talking about measuring the way we have + + + align:start position:0% +talking about measuring the way we have +been talking about and so on N is + + align:start position:0% +been talking about and so on N is + + + align:start position:0% +been talking about and so on N is +employment and a is labor productivity + + align:start position:0% +employment and a is labor productivity + + + align:start position:0% +employment and a is labor productivity +that is the output per work okay I want + + align:start position:0% +that is the output per work okay I want + + + align:start position:0% +that is the output per work okay I want +to make things very simple we're going + + align:start position:0% +to make things very simple we're going + + + align:start position:0% +to make things very simple we're going +to talk a lot about in the next part of + + align:start position:0% +to talk a lot about in the next part of + + + align:start position:0% +to talk a lot about in the next part of +the course in the part of growth about + + align:start position:0% +the course in the part of growth about + + + align:start position:0% +the course in the part of growth about +this a what moves this a over time what + + align:start position:0% +this a what moves this a over time what + + + align:start position:0% +this a what moves this a over time what +it does and so on but but I'm going to + + align:start position:0% +it does and so on but but I'm going to + + + align:start position:0% +it does and so on but but I'm going to +simplify things a lot here for now and + + align:start position:0% +simplify things a lot here for now and + + + align:start position:0% +simplify things a lot here for now and +I'm going to set a equal to one so it + + align:start position:0% +I'm going to set a equal to one so it + + + align:start position:0% +I'm going to set a equal to one so it +doesn't get any simpler than this as a + + align:start position:0% +doesn't get any simpler than this as a + + + align:start position:0% +doesn't get any simpler than this as a +production function this production + + align:start position:0% +production function this production + + + align:start position:0% +production function this production +function says you want to produce one + + align:start position:0% +function says you want to produce one + + + align:start position:0% +function says you want to produce one +more good you need one more + + align:start position:0% +more good you need one more + + + align:start position:0% +more good you need one more +worker okay this is what this says if + + align:start position:0% +worker okay this is what this says if + + + align:start position:0% +worker okay this is what this says if +you have 10 workers you produce 10 units + + align:start position:0% +you have 10 workers you produce 10 units + + + align:start position:0% +you have 10 workers you produce 10 units +of good if you have 11 workers you + + align:start position:0% +of good if you have 11 workers you + + + align:start position:0% +of good if you have 11 workers you +produce 11 units of good okay to produce + + align:start position:0% +produce 11 units of good okay to produce + + + align:start position:0% +produce 11 units of good okay to produce +one more unit of good you need one + + align:start position:0% +one more unit of good you need one + + + align:start position:0% +one more unit of good you need one +worker + + align:start position:0% +worker + + + align:start position:0% +worker +more now why do you think I'm I'm I'm + + align:start position:0% +more now why do you think I'm I'm I'm + + + align:start position:0% +more now why do you think I'm I'm I'm +I'm simplifying it so much and I'm right + + align:start position:0% +I'm simplifying it so much and I'm right + + + align:start position:0% +I'm simplifying it so much and I'm right +I'm even repeating this idea that one + + align:start position:0% +I'm even repeating this idea that one + + + align:start position:0% +I'm even repeating this idea that one +more worker one more unit of good + + align:start position:0% + + + + align:start position:0% + +that tells you that how much does it + + align:start position:0% +that tells you that how much does it + + + align:start position:0% +that tells you that how much does it +cost to the + + align:start position:0% +cost to the + + + align:start position:0% +cost to the +firm to the firm that has this + + align:start position:0% +firm to the firm that has this + + + align:start position:0% +firm to the firm that has this +production function to produce one extra + + align:start position:0% +production function to produce one extra + + + align:start position:0% +production function to produce one extra +unit of workers or of of of of one extra + + align:start position:0% +unit of workers or of of of of one extra + + + align:start position:0% +unit of workers or of of of of one extra +unit of + + align:start position:0% +unit of + + + align:start position:0% +unit of +goods well you have to ask a question + + align:start position:0% +goods well you have to ask a question + + + align:start position:0% +goods well you have to ask a question +well what will the firm have to do well + + align:start position:0% +well what will the firm have to do well + + + align:start position:0% +well what will the firm have to do well +the first so suppose a firm wants to + + align:start position:0% +the first so suppose a firm wants to + + + align:start position:0% +the first so suppose a firm wants to +produce one more units of goods what is + + align:start position:0% +produce one more units of goods what is + + + align:start position:0% +produce one more units of goods what is +it that it needs to + + align:start position:0% + + + + align:start position:0% + +do it needs to hire another another + + align:start position:0% +do it needs to hire another another + + + align:start position:0% +do it needs to hire another another +worker how much will that + + align:start position:0% + + + + align:start position:0% + +cost yeah the wage the wage exactly no + + align:start position:0% +cost yeah the wage the wage exactly no + + + align:start position:0% +cost yeah the wage the wage exactly no +so now we're beginning to so so this is + + align:start position:0% +so now we're beginning to so so this is + + + align:start position:0% +so now we're beginning to so so this is +the wage in this case is the cost per + + align:start position:0% +the wage in this case is the cost per + + + align:start position:0% +the wage in this case is the cost per +unit of production for this guy so the + + align:start position:0% +unit of production for this guy so the + + + align:start position:0% +unit of production for this guy so the +marginal cost of production for this + + align:start position:0% +marginal cost of production for this + + + align:start position:0% +marginal cost of production for this +firm is the wage all the rest + + align:start position:0% +firm is the wage all the rest + + + align:start position:0% +firm is the wage all the rest +intermediate inputs is all summarized + + align:start position:0% +intermediate inputs is all summarized + + + align:start position:0% +intermediate inputs is all summarized +this value added built on something + + align:start position:0% +this value added built on something + + + align:start position:0% +this value added built on something +else so this production function the + + align:start position:0% +else so this production function the + + + align:start position:0% +else so this production function the +simp as it is says exactly that the + + align:start position:0% +simp as it is says exactly that the + + + align:start position:0% +simp as it is says exactly that the +marginal cost of production is equal to + + align:start position:0% +marginal cost of production is equal to + + + align:start position:0% +marginal cost of production is equal to +the + + align:start position:0% +the + + + align:start position:0% +the +wage so assume that the way I'm so now + + align:start position:0% +wage so assume that the way I'm so now + + + align:start position:0% +wage so assume that the way I'm so now +I'm going to come up with a pricing + + align:start position:0% +I'm going to come up with a pricing + + + align:start position:0% +I'm going to come up with a pricing +Model A price setting rule so firms that + + align:start position:0% +Model A price setting rule so firms that + + + align:start position:0% +Model A price setting rule so firms that +understand how much more it cost to + + align:start position:0% +understand how much more it cost to + + + align:start position:0% +understand how much more it cost to +produce an extra unit of good now have + + align:start position:0% +produce an extra unit of good now have + + + align:start position:0% +produce an extra unit of good now have +to decide the price they want to charge + + align:start position:0% +to decide the price they want to charge + + + align:start position:0% +to decide the price they want to charge +for that extra unit of the + + align:start position:0% +for that extra unit of the + + + align:start position:0% +for that extra unit of the +good there's a lot that that comes into + + align:start position:0% +good there's a lot that that comes into + + + align:start position:0% +good there's a lot that that comes into +in that decision but but we're want to + + align:start position:0% +in that decision but but we're want to + + + align:start position:0% +in that decision but but we're want to +summarize it with a markup very simple + + align:start position:0% +summarize it with a markup very simple + + + align:start position:0% +summarize it with a markup very simple +when say look the The Firm will do the + + align:start position:0% +when say look the The Firm will do the + + + align:start position:0% +when say look the The Firm will do the +following we say it cost me one worker + + align:start position:0% +following we say it cost me one worker + + + align:start position:0% +following we say it cost me one worker +to produce one unit of X of good a + + align:start position:0% +to produce one unit of X of good a + + + align:start position:0% +to produce one unit of X of good a +worker cost me W so my the price I want + + align:start position:0% +worker cost me W so my the price I want + + + align:start position:0% +worker cost me W so my the price I want +to charge is 1 plus m m is a positive + + align:start position:0% +to charge is 1 plus m m is a positive + + + align:start position:0% +to charge is 1 plus m m is a positive +number times W okay so m is a number + + align:start position:0% +number times W okay so m is a number + + + align:start position:0% +number times W okay so m is a number +like 0.2 so you pay 100 in in the in the + + align:start position:0% +like 0.2 so you pay 100 in in the in the + + + align:start position:0% +like 0.2 so you pay 100 in in the in the +wage then you're going to charge and + + align:start position:0% +wage then you're going to charge and + + + align:start position:0% +wage then you're going to charge and +suppose the wage is 100 if the markup is + + align:start position:0% +suppose the wage is 100 if the markup is + + + align:start position:0% +suppose the wage is 100 if the markup is +20% you're going to set a price of 100 + + align:start position:0% +20% you're going to set a price of 100 + + + align:start position:0% +20% you're going to set a price of 100 +12 okay that's the price setting rule + + align:start position:0% +12 okay that's the price setting rule + + + align:start position:0% +12 okay that's the price setting rule +that we're going to adopt and again it's + + align:start position:0% +that we're going to adopt and again it's + + + align:start position:0% +that we're going to adopt and again it's +not that + + align:start position:0% +not that + + + align:start position:0% +not that +crazy simple but not that crazy so thus + + align:start position:0% +crazy simple but not that crazy so thus + + + align:start position:0% +crazy simple but not that crazy so thus +we call this the price setting equation + + align:start position:0% +we call this the price setting equation + + + align:start position:0% +we call this the price setting equation +The Firm takes the wage because that's a + + align:start position:0% +The Firm takes the wage because that's a + + + align:start position:0% +The Firm takes the wage because that's a +marginal cost of production and and then + + align:start position:0% +marginal cost of production and and then + + + align:start position:0% +marginal cost of production and and then +ER adds a marup and that's the final + + align:start position:0% +ER adds a marup and that's the final + + + align:start position:0% +ER adds a marup and that's the final +price now we can rewrite this price + + align:start position:0% +price now we can rewrite this price + + + align:start position:0% +price now we can rewrite this price +setting equation equation as a as a + + align:start position:0% +setting equation equation as a as a + + + align:start position:0% +setting equation equation as a as a +weight equation in the following sense + + align:start position:0% +weight equation in the following sense + + + align:start position:0% +weight equation in the following sense +it's still a price setting equation but + + align:start position:0% +it's still a price setting equation but + + + align:start position:0% +it's still a price setting equation but +this all that I've done here no is I + + align:start position:0% +this all that I've done here no is I + + + align:start position:0% +this all that I've done here no is I +divided by P and by one by P and 1 plus + + align:start position:0% +divided by P and by one by P and 1 plus + + + align:start position:0% +divided by P and by one by P and 1 plus +M and I get that the wage the the real + + align:start position:0% +M and I get that the wage the the real + + + align:start position:0% +M and I get that the wage the the real +wage the firm is willing to pay is equal + + align:start position:0% +wage the firm is willing to pay is equal + + + align:start position:0% +wage the firm is willing to pay is equal +to one over one plus the mark that's + + align:start position:0% +to one over one plus the mark that's + + + align:start position:0% +to one over one plus the mark that's +another way of saying this the same I + + align:start position:0% +another way of saying this the same I + + + align:start position:0% +another way of saying this the same I +took this price setting equation and I + + align:start position:0% +took this price setting equation and I + + + align:start position:0% +took this price setting equation and I +just rewrote it I rewrote it this way + + align:start position:0% +just rewrote it I rewrote it this way + + + align:start position:0% +just rewrote it I rewrote it this way +because then you know I when I look at + + align:start position:0% +because then you know I when I look at + + + align:start position:0% +because then you know I when I look at +the weight setting equation I also wrote + + align:start position:0% +the weight setting equation I also wrote + + + align:start position:0% +the weight setting equation I also wrote +it that that way W over something I want + + align:start position:0% +it that that way W over something I want + + + align:start position:0% +it that that way W over something I want +to write the price setting equation in + + align:start position:0% +to write the price setting equation in + + + align:start position:0% +to write the price setting equation in +the same sort of units as as my weight + + align:start position:0% +the same sort of units as as my weight + + + align:start position:0% +the same sort of units as as my weight +setting equation so then I can use one + + align:start position:0% +setting equation so then I can use one + + + align:start position:0% +setting equation so then I can use one +diagram put them together easily and and + + align:start position:0% +diagram put them together easily and and + + + align:start position:0% +diagram put them together easily and and +find an equilibrium of + + align:start position:0% +find an equilibrium of + + + align:start position:0% +find an equilibrium of +something okay so what you see here is + + align:start position:0% +something okay so what you see here is + + + align:start position:0% +something okay so what you see here is +for example is that the higher is the + + align:start position:0% +for example is that the higher is the + + + align:start position:0% +for example is that the higher is the +markup the lower is the real wage the + + align:start position:0% +markup the lower is the real wage the + + + align:start position:0% +markup the lower is the real wage the +firm is willing to + + align:start position:0% +firm is willing to + + + align:start position:0% +firm is willing to +offer you see that the and this is an + + align:start position:0% +offer you see that the and this is an + + + align:start position:0% +offer you see that the and this is an +equilibrium at the level of the economy + + align:start position:0% +equilibrium at the level of the economy + + + align:start position:0% +equilibrium at the level of the economy +it's not you individually but on average + + align:start position:0% +it's not you individually but on average + + + align:start position:0% +it's not you individually but on average +that's what end up happening firms on + + align:start position:0% +that's what end up happening firms on + + + align:start position:0% +that's what end up happening firms on +average end up charging a higher markup + + align:start position:0% +average end up charging a higher markup + + + align:start position:0% +average end up charging a higher markup +it has to be the case that in + + align:start position:0% +it has to be the case that in + + + align:start position:0% +it has to be the case that in +equilibrium the real wage offer by the + + align:start position:0% +equilibrium the real wage offer by the + + + align:start position:0% +equilibrium the real wage offer by the +firms is lower that's what this says + + align:start position:0% +firms is lower that's what this says + + + align:start position:0% +firms is lower that's what this says +okay so if we're in a situation where + + align:start position:0% +okay so if we're in a situation where + + + align:start position:0% +okay so if we're in a situation where +the markup was zero and now all of the + + align:start position:0% +the markup was zero and now all of the + + + align:start position:0% +the markup was zero and now all of the +sudden because of imperfect competition + + align:start position:0% +sudden because of imperfect competition + + + align:start position:0% +sudden because of imperfect competition +or perhaps some price of a key input + + align:start position:0% +or perhaps some price of a key input + + + align:start position:0% +or perhaps some price of a key input +went up and it's not will measure in Val + + align:start position:0% +went up and it's not will measure in Val + + + align:start position:0% +went up and it's not will measure in Val +whatever H ER if the market goes to to + + align:start position:0% +whatever H ER if the market goes to to + + + align:start position:0% +whatever H ER if the market goes to to +to + + align:start position:0% +to + + + align:start position:0% +to +one then the real wage in equilibrium + + align:start position:0% +one then the real wage in equilibrium + + + align:start position:0% +one then the real wage in equilibrium +will fall to have what it used to be + + align:start position:0% +will fall to have what it used to be + + + align:start position:0% +will fall to have what it used to be +that's what this question that's what + + align:start position:0% +that's what this question that's what + + + align:start position:0% +that's what this question that's what +the firms will + + align:start position:0% +the firms will + + + align:start position:0% +the firms will +offer whether that's an equilibrium not + + align:start position:0% +offer whether that's an equilibrium not + + + align:start position:0% +offer whether that's an equilibrium not +we shall see or how do we get to that to + + align:start position:0% +we shall see or how do we get to that to + + + align:start position:0% +we shall see or how do we get to that to +be an equilibrium we shall see but + + align:start position:0% +be an equilibrium we shall see but + + + align:start position:0% +be an equilibrium we shall see but +that's what the firms will offer that's + + align:start position:0% +that's what the firms will offer that's + + + align:start position:0% +that's what the firms will offer that's +what the price setting equation says in + + align:start position:0% +what the price setting equation says in + + + align:start position:0% +what the price setting equation says in +fact you already know from this equation + + align:start position:0% +fact you already know from this equation + + + align:start position:0% +fact you already know from this equation +that that's what the real wage will be + + align:start position:0% +that that's what the real wage will be + + + align:start position:0% +that that's what the real wage will be +because there's no variable here that + + align:start position:0% +because there's no variable here that + + + align:start position:0% +because there's no variable here that +can adjust to that what happens is + + align:start position:0% +can adjust to that what happens is + + + align:start position:0% +can adjust to that what happens is +something else we have to give in the + + align:start position:0% +something else we have to give in the + + + align:start position:0% +something else we have to give in the +economy so this ends up being the + + align:start position:0% +economy so this ends up being the + + + align:start position:0% +economy so this ends up being the +equilibrium wage okay but you'll + + align:start position:0% +equilibrium wage okay but you'll + + + align:start position:0% +equilibrium wage okay but you'll +understand that a little later or you'll + + align:start position:0% +understand that a little later or you'll + + + align:start position:0% +understand that a little later or you'll +understand it better a little + + align:start position:0% +understand it better a little + + + align:start position:0% +understand it better a little +later okay so now we're almost ready to + + align:start position:0% +later okay so now we're almost ready to + + + align:start position:0% +later okay so now we're almost ready to +come up with to discuss a very important + + align:start position:0% +come up with to discuss a very important + + + align:start position:0% +come up with to discuss a very important +Concept in + + align:start position:0% +Concept in + + + align:start position:0% +Concept in +macroeconomics and that's the concept of + + align:start position:0% +macroeconomics and that's the concept of + + + align:start position:0% +macroeconomics and that's the concept of +the natural rate of + + align:start position:0% +the natural rate of + + + align:start position:0% +the natural rate of +unemployment now the first warning is + + align:start position:0% +unemployment now the first warning is + + + align:start position:0% +unemployment now the first warning is +there's nothing natural about the + + align:start position:0% +there's nothing natural about the + + + align:start position:0% +there's nothing natural about the +natural rate of unemployment it's not + + align:start position:0% +natural rate of unemployment it's not + + + align:start position:0% +natural rate of unemployment it's not +sort of you know something that God gave + + align:start position:0% +sort of you know something that God gave + + + align:start position:0% +sort of you know something that God gave +us or anything like that okay I'll say + + align:start position:0% +us or anything like that okay I'll say + + + align:start position:0% +us or anything like that okay I'll say +for us and and what typically means the + + align:start position:0% +for us and and what typically means the + + + align:start position:0% +for us and and what typically means the +natural rate of + + align:start position:0% +natural rate of + + + align:start position:0% +natural rate of +unemployment simply means what I wrote + + align:start position:0% +unemployment simply means what I wrote + + + align:start position:0% +unemployment simply means what I wrote +there which is the unemployment that + + align:start position:0% +there which is the unemployment that + + + align:start position:0% +there which is the unemployment that +takes place when the expected prices + + align:start position:0% +takes place when the expected prices + + + align:start position:0% +takes place when the expected prices +equal to actual + + align:start position:0% +equal to actual + + + align:start position:0% +equal to actual +prices okay that's what will Define for + + align:start position:0% +prices okay that's what will Define for + + + align:start position:0% +prices okay that's what will Define for +this class for this course will Define + + align:start position:0% +this class for this course will Define + + + align:start position:0% +this class for this course will Define +the natural rate of unemployment the + + align:start position:0% +the natural rate of unemployment the + + + align:start position:0% +the natural rate of unemployment the +natural rate of unemployment is when the + + align:start position:0% +natural rate of unemployment is when the + + + align:start position:0% +natural rate of unemployment is when the +expected price is equal to P that's what + + align:start position:0% +expected price is equal to P that's what + + + align:start position:0% +expected price is equal to P that's what +we mean if I we ask you any question + + align:start position:0% +we mean if I we ask you any question + + + align:start position:0% +we mean if I we ask you any question +about the natural rate employment we + + align:start position:0% +about the natural rate employment we + + + align:start position:0% +about the natural rate employment we +don't mean that that's what is good that + + align:start position:0% +don't mean that that's what is good that + + + align:start position:0% +don't mean that that's what is good that +that's what is bad that's what G decided + + align:start position:0% +that's what is bad that's what G decided + + + align:start position:0% +that's what is bad that's what G decided +or someone else decided this is all that + + align:start position:0% +or someone else decided this is all that + + + align:start position:0% +or someone else decided this is all that +it means is that in any equation where + + align:start position:0% +it means is that in any equation where + + + align:start position:0% +it means is that in any equation where +you have P you can stick in p and then + + align:start position:0% +you have P you can stick in p and then + + + align:start position:0% +you have P you can stick in p and then +solve for equilibrium and that the + + align:start position:0% +solve for equilibrium and that the + + + align:start position:0% +solve for equilibrium and that the +employment rate that comes from that is + + align:start position:0% +employment rate that comes from that is + + + align:start position:0% +employment rate that comes from that is +what we call the natural rate of + + align:start position:0% +what we call the natural rate of + + + align:start position:0% +what we call the natural rate of +unemployment because of this you can + + align:start position:0% +unemployment because of this you can + + + align:start position:0% +unemployment because of this you can +also think of that unemployment rate as + + align:start position:0% +also think of that unemployment rate as + + + align:start position:0% +also think of that unemployment rate as +sort of as a good proxy for what is + + align:start position:0% +sort of as a good proxy for what is + + + align:start position:0% +sort of as a good proxy for what is +likely to be the average rate of + + align:start position:0% +likely to be the average rate of + + + align:start position:0% +likely to be the average rate of +unemployment of an economy over a longer + + align:start position:0% +unemployment of an economy over a longer + + + align:start position:0% +unemployment of an economy over a longer +period of time you know because people + + align:start position:0% +period of time you know because people + + + align:start position:0% +period of time you know because people +are likely to be full all the time in + + align:start position:0% +are likely to be full all the time in + + + align:start position:0% +are likely to be full all the time in +the same direction so sometimes they're + + align:start position:0% +the same direction so sometimes they're + + + align:start position:0% +the same direction so sometimes they're +going to expect a higher price than it + + align:start position:0% +going to expect a higher price than it + + + align:start position:0% +going to expect a higher price than it +is sometimes it's a lower and so on on + + align:start position:0% +is sometimes it's a lower and so on on + + + align:start position:0% +is sometimes it's a lower and so on on +average unless there is something very + + align:start position:0% +average unless there is something very + + + align:start position:0% +average unless there is something very +weird going on they're going to get + + align:start position:0% +weird going on they're going to get + + + align:start position:0% +weird going on they're going to get +right but because because you know more + + align:start position:0% +right but because because you know more + + + align:start position:0% +right but because because you know more +or less what the level of inflation of + + align:start position:0% +or less what the level of inflation of + + + align:start position:0% +or less what the level of inflation of +the economy is sometimes you miss up + + align:start position:0% +the economy is sometimes you miss up + + + align:start position:0% +the economy is sometimes you miss up +sometimes you Mo down but on average + + align:start position:0% +sometimes you Mo down but on average + + + align:start position:0% +sometimes you Mo down but on average +you're going to be right if you if you + + align:start position:0% +you're going to be right if you if you + + + align:start position:0% +you're going to be right if you if you +take an average of a long period of time + + align:start position:0% +take an average of a long period of time + + + align:start position:0% +take an average of a long period of time +so for that reason you can also + + align:start position:0% +so for that reason you can also + + + align:start position:0% +so for that reason you can also +interpret this natural rate of + + align:start position:0% +interpret this natural rate of + + + align:start position:0% +interpret this natural rate of +unemployment as the unemployment rate of + + align:start position:0% +unemployment as the unemployment rate of + + + align:start position:0% +unemployment as the unemployment rate of +the medium run if you will so you have + + align:start position:0% +the medium run if you will so you have + + + align:start position:0% +the medium run if you will so you have +collected enough data and positive + + align:start position:0% +collected enough data and positive + + + align:start position:0% +collected enough data and positive +errors at balance with negative errors + + align:start position:0% +errors at balance with negative errors + + + align:start position:0% +errors at balance with negative errors +and so on okay but that's all that we + + align:start position:0% +and so on okay but that's all that we + + + align:start position:0% +and so on okay but that's all that we +mean by the natural rate of + + align:start position:0% +mean by the natural rate of + + + align:start position:0% +mean by the natural rate of +unemployment okay now notice that with + + align:start position:0% +unemployment okay now notice that with + + + align:start position:0% +unemployment okay now notice that with +this assumption that P e is equal to P I + + align:start position:0% +this assumption that P e is equal to P I + + + align:start position:0% +this assumption that P e is equal to P I +can go back to my weight setting + + align:start position:0% +can go back to my weight setting + + + align:start position:0% +can go back to my weight setting +equation which was W over p e equal to F + + align:start position:0% +equation which was W over p e equal to F + + + align:start position:0% +equation which was W over p e equal to F +that I think I don't remember where I + + align:start position:0% +that I think I don't remember where I + + + align:start position:0% +that I think I don't remember where I +had divided by P but I had P there I'm + + align:start position:0% +had divided by P but I had P there I'm + + + align:start position:0% +had divided by P but I had P there I'm +going to divide by P both sides and then + + align:start position:0% +going to divide by P both sides and then + + + align:start position:0% +going to divide by P both sides and then +I'm going to set P equal to p and now I + + align:start position:0% +I'm going to set P equal to p and now I + + + align:start position:0% +I'm going to set P equal to p and now I +have that my wage setting equation can + + align:start position:0% +have that my wage setting equation can + + + align:start position:0% +have that my wage setting equation can +be written this way and notice that the + + align:start position:0% +be written this way and notice that the + + + align:start position:0% +be written this way and notice that the +unemployment rate I put here is the n an + + align:start position:0% +unemployment rate I put here is the n an + + + align:start position:0% +unemployment rate I put here is the n an +it's a natural rate of + + align:start position:0% +it's a natural rate of + + + align:start position:0% +it's a natural rate of +unemployment because once I in a model + + align:start position:0% +unemployment because once I in a model + + + align:start position:0% +unemployment because once I in a model +in which I assume that p is equal to P + + align:start position:0% +in which I assume that p is equal to P + + + align:start position:0% +in which I assume that p is equal to P +that employment rate that comes out of + + align:start position:0% +that employment rate that comes out of + + + align:start position:0% +that employment rate that comes out of +that is a natural rate of + + align:start position:0% +that is a natural rate of + + + align:start position:0% +that is a natural rate of +unemployment okay that's that's all that + + align:start position:0% +unemployment okay that's that's all that + + + align:start position:0% +unemployment okay that's that's all that +it just means it says okay you allow me + + align:start position:0% +it just means it says okay you allow me + + + align:start position:0% +it just means it says okay you allow me +to to replace P by P well then I can + + align:start position:0% +to to replace P by P well then I can + + + align:start position:0% +to to replace P by P well then I can +call my unemployment rate here the + + align:start position:0% +call my unemployment rate here the + + + align:start position:0% +call my unemployment rate here the +natural rate of + + align:start position:0% + + + + align:start position:0% + +unemployment and it has lots of names + + align:start position:0% +unemployment and it has lots of names + + + align:start position:0% +unemployment and it has lots of names +it's that natural rate the structural + + align:start position:0% +it's that natural rate the structural + + + align:start position:0% +it's that natural rate the structural +rate of unemployment and so + + align:start position:0% + + + + align:start position:0% + +on now what this tells you I mean you + + align:start position:0% +on now what this tells you I mean you + + + align:start position:0% +on now what this tells you I mean you +can see the slope of this + + align:start position:0% +can see the slope of this + + + align:start position:0% +can see the slope of this +function if the natural rate of + + align:start position:0% +function if the natural rate of + + + align:start position:0% +function if the natural rate of +unemployment is higher in this + + align:start position:0% +unemployment is higher in this + + + align:start position:0% +unemployment is higher in this +economy what is the real wage that comes + + align:start position:0% +economy what is the real wage that comes + + + align:start position:0% +economy what is the real wage that comes +from the weight setting equation lower + + align:start position:0% +from the weight setting equation lower + + + align:start position:0% +from the weight setting equation lower +so this a downward sloping curve in the + + align:start position:0% +so this a downward sloping curve in the + + + align:start position:0% +so this a downward sloping curve in the +space of wages to real wages to an + + align:start position:0% +space of wages to real wages to an + + + align:start position:0% +space of wages to real wages to an +employment to the Natural rate of an + + align:start position:0% +employment to the Natural rate of an + + + align:start position:0% +employment to the Natural rate of an +employment it's a downward sloping curve + + align:start position:0% +employment it's a downward sloping curve + + + align:start position:0% +employment it's a downward sloping curve +for the reasons we discussed before + + align:start position:0% +for the reasons we discussed before + + + align:start position:0% +for the reasons we discussed before +bargaining power and so on okay so I can + + align:start position:0% +bargaining power and so on okay so I can + + + align:start position:0% +bargaining power and so on okay so I can +put together remember the the the price + + align:start position:0% +put together remember the the the price + + + align:start position:0% +put together remember the the the price +setting equation led me to to also an + + align:start position:0% +setting equation led me to to also an + + + align:start position:0% +setting equation led me to to also an +equation the real wage which was not a + + align:start position:0% +equation the real wage which was not a + + + align:start position:0% +equation the real wage which was not a +function of anything it was only a + + align:start position:0% +function of anything it was only a + + + align:start position:0% +function of anything it was only a +function of parameters so that's a + + align:start position:0% +function of parameters so that's a + + + align:start position:0% +function of parameters so that's a +horizontal Cur curve in the space of + + align:start position:0% +horizontal Cur curve in the space of + + + align:start position:0% +horizontal Cur curve in the space of +real wages and unemployment natural rate + + align:start position:0% +real wages and unemployment natural rate + + + align:start position:0% +real wages and unemployment natural rate +of unemployment here we have a downward + + align:start position:0% +of unemployment here we have a downward + + + align:start position:0% +of unemployment here we have a downward +sloping curve and the intersection of + + align:start position:0% +sloping curve and the intersection of + + + align:start position:0% +sloping curve and the intersection of +these two curves is the natural rate of + + align:start position:0% +these two curves is the natural rate of + + + align:start position:0% +these two curves is the natural rate of +unemployment okay so this was the price + + align:start position:0% +unemployment okay so this was the price + + + align:start position:0% +unemployment okay so this was the price +setting relation remember it's 1 over 1 + + align:start position:0% +setting relation remember it's 1 over 1 + + + align:start position:0% +setting relation remember it's 1 over 1 +plus M this is the weight setting + + align:start position:0% +plus M this is the weight setting + + + align:start position:0% +plus M this is the weight setting +equation H with the asson that P is + + align:start position:0% +equation H with the asson that P is + + + align:start position:0% +equation H with the asson that P is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +p and that's the natural rate of + + align:start position:0% +p and that's the natural rate of + + + align:start position:0% +p and that's the natural rate of +unemployment and here you can understand + + align:start position:0% +unemployment and here you can understand + + + align:start position:0% +unemployment and here you can understand +what I said before is that you see in + + align:start position:0% +what I said before is that you see in + + + align:start position:0% +what I said before is that you see in +this economy the real wage because this + + align:start position:0% +this economy the real wage because this + + + align:start position:0% +this economy the real wage because this +price setting equation is flat in the + + align:start position:0% +price setting equation is flat in the + + + align:start position:0% +price setting equation is flat in the +simple economy the real wage is pinned + + align:start position:0% +simple economy the real wage is pinned + + + align:start position:0% +simple economy the real wage is pinned +down by the + + align:start position:0% +down by the + + + align:start position:0% +down by the +firm by the firms collectively and not + + align:start position:0% +firm by the firms collectively and not + + + align:start position:0% +firm by the firms collectively and not +collectively in + + align:start position:0% +collectively in + + + align:start position:0% +collectively in +anistic way you know it's what happens + + align:start position:0% +anistic way you know it's what happens + + + align:start position:0% +anistic way you know it's what happens +in equilibrium H is by that but the + + align:start position:0% +in equilibrium H is by that but the + + + align:start position:0% +in equilibrium H is by that but the +equilibrium unemploy natural rate of + + align:start position:0% +equilibrium unemploy natural rate of + + + align:start position:0% +equilibrium unemploy natural rate of +unemployment is intersection of the real + + align:start position:0% +unemployment is intersection of the real + + + align:start position:0% +unemployment is intersection of the real +wage set by the firms and the weight + + align:start position:0% +wage set by the firms and the weight + + + align:start position:0% +wage set by the firms and the weight +setting + + align:start position:0% + + + + align:start position:0% + +relationship so what + + align:start position:0% +relationship so what + + + align:start position:0% +relationship so what +happens in a to a point say to the right + + align:start position:0% +happens in a to a point say to the right + + + align:start position:0% +happens in a to a point say to the right +what happens in this point here what is + + align:start position:0% +what happens in this point here what is + + + align:start position:0% +what happens in this point here what is +the situation we have + + align:start position:0% + + + + align:start position:0% + +well at that high level of unemployment + + align:start position:0% +well at that high level of unemployment + + + align:start position:0% +well at that high level of unemployment +workers are willing to work for much + + align:start position:0% +workers are willing to work for much + + + align:start position:0% +workers are willing to work for much +lower real wages than the firms are + + align:start position:0% +lower real wages than the firms are + + + align:start position:0% +lower real wages than the firms are +offering okay this is what workers at + + align:start position:0% +offering okay this is what workers at + + + align:start position:0% +offering okay this is what workers at +this level of unemployment very high + + align:start position:0% +this level of unemployment very high + + + align:start position:0% +this level of unemployment very high +level of unemployment workers would be + + align:start position:0% +level of unemployment workers would be + + + align:start position:0% +level of unemployment workers would be +find with this firms are paying + + align:start position:0% + + + + align:start position:0% + +that so unemployment is very likely to + + align:start position:0% +that so unemployment is very likely to + + + align:start position:0% +that so unemployment is very likely to +be falling because workers are not + + align:start position:0% +be falling because workers are not + + + align:start position:0% +be falling because workers are not +demanding a lot and and and firms you + + align:start position:0% +demanding a lot and and and firms you + + + align:start position:0% +demanding a lot and and and firms you +know are going to hire all this work + + align:start position:0% +know are going to hire all this work + + + align:start position:0% +know are going to hire all this work +the opposite + + align:start position:0% +the opposite + + + align:start position:0% +the opposite +here if here workers are demanding a + + align:start position:0% +here if here workers are demanding a + + + align:start position:0% +here if here workers are demanding a +wage that is much higher than firms are + + align:start position:0% +wage that is much higher than firms are + + + align:start position:0% +wage that is much higher than firms are +willing to pay that's likely to lead to + + align:start position:0% +willing to pay that's likely to lead to + + + align:start position:0% +willing to pay that's likely to lead to +more unemployment because firms are + + align:start position:0% +more unemployment because firms are + + + align:start position:0% +more unemployment because firms are +going to be very reluctant to hire these + + align:start position:0% +going to be very reluctant to hire these + + + align:start position:0% +going to be very reluctant to hire these +very expensive workers okay so that's + + align:start position:0% +very expensive workers okay so that's + + + align:start position:0% +very expensive workers okay so that's +going to build unemployment in this + + align:start position:0% +going to build unemployment in this + + + align:start position:0% +going to build unemployment in this +direction good so that's that's the + + align:start position:0% +direction good so that's that's the + + + align:start position:0% +direction good so that's that's the +natural rate of unemployment again + + align:start position:0% +natural rate of unemployment again + + + align:start position:0% +natural rate of unemployment again +nothing natural about it is the + + align:start position:0% +nothing natural about it is the + + + align:start position:0% +nothing natural about it is the +equilibrium when you assume the expected + + align:start position:0% +equilibrium when you assume the expected + + + align:start position:0% +equilibrium when you assume the expected +price is equal to price so so there are + + align:start position:0% +price is equal to price so so there are + + + align:start position:0% +price is equal to price so so there are +some important parameters in this + + align:start position:0% +some important parameters in this + + + align:start position:0% +some important parameters in this +diagram here one is this m a markup + + align:start position:0% +diagram here one is this m a markup + + + align:start position:0% +diagram here one is this m a markup +that's a parameter very important markup + + align:start position:0% +that's a parameter very important markup + + + align:start position:0% +that's a parameter very important markup +here to to see if the markup changes the + + align:start position:0% +here to to see if the markup changes the + + + align:start position:0% +here to to see if the markup changes the +natural rate of unemployment will + + align:start position:0% +natural rate of unemployment will + + + align:start position:0% +natural rate of unemployment will +change there's another set of parameter + + align:start position:0% +change there's another set of parameter + + + align:start position:0% +change there's another set of parameter +here which is z we took us given the + + align:start position:0% +here which is z we took us given the + + + align:start position:0% +here which is z we took us given the +institution that protect the bargaining + + align:start position:0% +institution that protect the bargaining + + + align:start position:0% +institution that protect the bargaining +power of workers institutions supporting + + align:start position:0% +power of workers institutions supporting + + + align:start position:0% +power of workers institutions supporting +institutions the Z that's a parameter + + align:start position:0% +institutions the Z that's a parameter + + + align:start position:0% +institutions the Z that's a parameter +here if that changes the natural rate of + + align:start position:0% +here if that changes the natural rate of + + + align:start position:0% +here if that changes the natural rate of +unemployment will change which is again + + align:start position:0% +unemployment will change which is again + + + align:start position:0% +unemployment will change which is again +something that confirms there's nothing + + align:start position:0% +something that confirms there's nothing + + + align:start position:0% +something that confirms there's nothing +natural about the natural rate of + + align:start position:0% +natural about the natural rate of + + + align:start position:0% +natural about the natural rate of +unemployment so let me just do it in + + align:start position:0% +unemployment so let me just do it in + + + align:start position:0% +unemployment so let me just do it in +equations very quickly and then and + + align:start position:0% +equations very quickly and then and + + + align:start position:0% +equations very quickly and then and +then I'll do a a couple of important + + align:start position:0% +then I'll do a a couple of important + + + align:start position:0% +then I'll do a a couple of important +shifts H so in terms of equation all + + align:start position:0% +shifts H so in terms of equation all + + + align:start position:0% +shifts H so in terms of equation all +that I did is says look the weight + + align:start position:0% +that I did is says look the weight + + + align:start position:0% +that I did is says look the weight +weight setting equation the price + + align:start position:0% +weight setting equation the price + + + align:start position:0% +weight setting equation the price +setting equation gives us that the + + align:start position:0% +setting equation gives us that the + + + align:start position:0% +setting equation gives us that the +weight setting equation gives us that + + align:start position:0% +weight setting equation gives us that + + + align:start position:0% +weight setting equation gives us that +therefore that equal to that that's the + + align:start position:0% +therefore that equal to that that's the + + + align:start position:0% +therefore that equal to that that's the +point we found that's the natural rate + + align:start position:0% +point we found that's the natural rate + + + align:start position:0% +point we found that's the natural rate +employ okay so from here that's when the + + align:start position:0% +employ okay so from here that's when the + + + align:start position:0% +employ okay so from here that's when the +two are equal this is was the flat curve + + align:start position:0% +two are equal this is was the flat curve + + + align:start position:0% +two are equal this is was the flat curve +this is was the downward sloping curve + + align:start position:0% +this is was the downward sloping curve + + + align:start position:0% +this is was the downward sloping curve +well these two are + + align:start position:0% +well these two are + + + align:start position:0% +well these two are +equal H when these two things are equal + + align:start position:0% +equal H when these two things are equal + + + align:start position:0% +equal H when these two things are equal +okay and that's what you get there so + + align:start position:0% +okay and that's what you get there so + + + align:start position:0% +okay and that's what you get there so +from there you solve the natural rate of + + align:start position:0% +from there you solve the natural rate of + + + align:start position:0% +from there you solve the natural rate of +unemployment what do you think happens + + align:start position:0% +unemployment what do you think happens + + + align:start position:0% +unemployment what do you think happens +to the Natural rate of unemployment is z + + align:start position:0% +to the Natural rate of unemployment is z + + + align:start position:0% +to the Natural rate of unemployment is z +goes + + align:start position:0% + + + + align:start position:0% + +up let's just be very mechanic at this + + align:start position:0% +up let's just be very mechanic at this + + + align:start position:0% +up let's just be very mechanic at this +point just math + + align:start position:0% +point just math + + + align:start position:0% +point just math +if Z goes up what what happens to + + align:start position:0% + + + + align:start position:0% + +F goes up no if Z was positive well the + + align:start position:0% +F goes up no if Z was positive well the + + + align:start position:0% +F goes up no if Z was positive well the +right hand side hasn't gone + + align:start position:0% +right hand side hasn't gone + + + align:start position:0% +right hand side hasn't gone +up so this went + + align:start position:0% +up so this went + + + align:start position:0% +up so this went +up something has to give so F comes back + + align:start position:0% +up something has to give so F comes back + + + align:start position:0% +up something has to give so F comes back +down and the only thing that can give + + align:start position:0% +down and the only thing that can give + + + align:start position:0% +down and the only thing that can give +the only thing is endogenous in that + + align:start position:0% +the only thing is endogenous in that + + + align:start position:0% +the only thing is endogenous in that +picture there is the natural rate of + + align:start position:0% +picture there is the natural rate of + + + align:start position:0% +picture there is the natural rate of +unemployment so if Z goes up F goes up + + align:start position:0% +unemployment so if Z goes up F goes up + + + align:start position:0% +unemployment so if Z goes up F goes up +well I need to bring F back down because + + align:start position:0% +well I need to bring F back down because + + + align:start position:0% +well I need to bring F back down because +the right hand side hasn't given an + + align:start position:0% +the right hand side hasn't given an + + + align:start position:0% +the right hand side hasn't given an +inch so what do I have to do to Natural + + align:start position:0% +inch so what do I have to do to Natural + + + align:start position:0% +inch so what do I have to do to Natural +rate of unemployment for f to come back + + align:start position:0% +rate of unemployment for f to come back + + + align:start position:0% +rate of unemployment for f to come back +down rise no because that's what we + + align:start position:0% +down rise no because that's what we + + + align:start position:0% +down rise no because that's what we +weaken bargaining power workers + + align:start position:0% +weaken bargaining power workers + + + align:start position:0% +weaken bargaining power workers +bargaining power got stronger increasing + + align:start position:0% +bargaining power got stronger increasing + + + align:start position:0% +bargaining power got stronger increasing +Z well I have to weaken it some I don't + + align:start position:0% +Z well I have to weaken it some I don't + + + align:start position:0% +Z well I have to weaken it some I don't +have to equilibrium will weaken it + + align:start position:0% +have to equilibrium will weaken it + + + align:start position:0% +have to equilibrium will weaken it +somehow so that we end up in the same + + align:start position:0% +somehow so that we end up in the same + + + align:start position:0% +somehow so that we end up in the same +situation with the same real wage that + + align:start position:0% +situation with the same real wage that + + + align:start position:0% +situation with the same real wage that +we had before which was equal to 1 over + + align:start position:0% +we had before which was equal to 1 over + + + align:start position:0% +we had before which was equal to 1 over +1 plus + + align:start position:0% +1 plus + + + align:start position:0% +1 plus +what happens if M goes + + align:start position:0% +what happens if M goes + + + align:start position:0% +what happens if M goes +up well if M goes up markups go up that + + align:start position:0% +up well if M goes up markups go up that + + + align:start position:0% +up well if M goes up markups go up that +means firm's real + + align:start position:0% +means firm's real + + + align:start position:0% +means firm's real +wage the real wage firms offer + + align:start position:0% +wage the real wage firms offer + + + align:start position:0% +wage the real wage firms offer +drops so I need if this right hand side + + align:start position:0% +drops so I need if this right hand side + + + align:start position:0% +drops so I need if this right hand side +drops then I need the left hand side to + + align:start position:0% +drops then I need the left hand side to + + + align:start position:0% +drops then I need the left hand side to +drop drop as well and the only thing + + align:start position:0% +drop drop as well and the only thing + + + align:start position:0% +drop drop as well and the only thing +that is endogenous here is the natural + + align:start position:0% +that is endogenous here is the natural + + + align:start position:0% +that is endogenous here is the natural +rate of an + + align:start position:0% +rate of an + + + align:start position:0% +rate of an +employment so I know that I need to but + + align:start position:0% +employment so I know that I need to but + + + align:start position:0% +employment so I know that I need to but +to drop F what do I need to do to us + + align:start position:0% + + + + align:start position:0% + +so I need to bring F down and the only + + align:start position:0% +so I need to bring F down and the only + + + align:start position:0% +so I need to bring F down and the only +tool you have is not a tool but in + + align:start position:0% +tool you have is not a tool but in + + + align:start position:0% +tool you have is not a tool but in +equilibrium that will can change here is + + align:start position:0% +equilibrium that will can change here is + + + align:start position:0% +equilibrium that will can change here is +UN which + + align:start position:0% +UN which + + + align:start position:0% +UN which +will it will increase un because that + + align:start position:0% +will it will increase un because that + + + align:start position:0% +will it will increase un because that +will reduce bargaining power of workers + + align:start position:0% +will reduce bargaining power of workers + + + align:start position:0% +will reduce bargaining power of workers +and that will reduce the the real wage + + align:start position:0% +and that will reduce the the real wage + + + align:start position:0% +and that will reduce the the real wage +demand and therefore you restore + + align:start position:0% +demand and therefore you restore + + + align:start position:0% +demand and therefore you restore +equilibrium that way so this + + align:start position:0% +equilibrium that way so this + + + align:start position:0% +equilibrium that way so this +environments have a nasty environment + + align:start position:0% +environments have a nasty environment + + + align:start position:0% +environments have a nasty environment +for workers in a sense no because it's + + align:start position:0% +for workers in a sense no because it's + + + align:start position:0% +for workers in a sense no because it's +always the thecate Val is is the natural + + align:start position:0% +always the thecate Val is is the natural + + + align:start position:0% +always the thecate Val is is the natural +rate of + + align:start position:0% +rate of + + + align:start position:0% +rate of +unemployment so here you have what I + + align:start position:0% +unemployment so here you have what I + + + align:start position:0% +unemployment so here you have what I +just said in in pictures so that's + + align:start position:0% +just said in in pictures so that's + + + align:start position:0% +just said in in pictures so that's +example of Z going + + align:start position:0% +example of Z going + + + align:start position:0% +example of Z going +up bargaining power of workers going up + + align:start position:0% +up bargaining power of workers going up + + + align:start position:0% +up bargaining power of workers going up +so suppose you start at an equilibrium + + align:start position:0% +so suppose you start at an equilibrium + + + align:start position:0% +so suppose you start at an equilibrium +like this and now now Z goes + + align:start position:0% +like this and now now Z goes + + + align:start position:0% +like this and now now Z goes +up well that means that workers for any + + align:start position:0% +up well that means that workers for any + + + align:start position:0% +up well that means that workers for any +given level of unemployment natural rate + + align:start position:0% +given level of unemployment natural rate + + + align:start position:0% +given level of unemployment natural rate +of unemployment want a higher wage + + align:start position:0% +of unemployment want a higher wage + + + align:start position:0% +of unemployment want a higher wage +because they have more marketing + + align:start position:0% +because they have more marketing + + + align:start position:0% +because they have more marketing +power well that higher wage is + + align:start position:0% +power well that higher wage is + + + align:start position:0% +power well that higher wage is +inconsistent with the wage that firms + + align:start position:0% +inconsistent with the wage that firms + + + align:start position:0% +inconsistent with the wage that firms +want to pay what restores equilibrium is + + align:start position:0% +want to pay what restores equilibrium is + + + align:start position:0% +want to pay what restores equilibrium is +unemployment the natural rate of + + align:start position:0% +unemployment the natural rate of + + + align:start position:0% +unemployment the natural rate of +unemployment goes + + align:start position:0% +unemployment goes + + + align:start position:0% +unemployment goes +up enough so that the wage demand sort + + align:start position:0% +up enough so that the wage demand sort + + + align:start position:0% +up enough so that the wage demand sort +of comes down to the same original level + + align:start position:0% +of comes down to the same original level + + + align:start position:0% +of comes down to the same original level +because this this price setting equation + + align:start position:0% +because this this price setting equation + + + align:start position:0% +because this this price setting equation +is completely flat okay so there you + + align:start position:0% +is completely flat okay so there you + + + align:start position:0% +is completely flat okay so there you +have a situation where bargaining power + + align:start position:0% +have a situation where bargaining power + + + align:start position:0% +have a situation where bargaining power +of workers went up and all that end up + + align:start position:0% +of workers went up and all that end up + + + align:start position:0% +of workers went up and all that end up +happening is is that in the medium run + + align:start position:0% +happening is is that in the medium run + + + align:start position:0% +happening is is that in the medium run +at least that the natural rate of + + align:start position:0% +at least that the natural rate of + + + align:start position:0% +at least that the natural rate of +unemployment went up that's very much + + align:start position:0% +unemployment went up that's very much + + + align:start position:0% +unemployment went up that's very much +the story of Europe by the way in the + + align:start position:0% +the story of Europe by the way in the + + + align:start position:0% +the story of Europe by the way in the +80s France in particular in France had + + align:start position:0% +80s France in particular in France had + + + align:start position:0% +80s France in particular in France had +sort of major labor reforms Z boosting + + align:start position:0% +sort of major labor reforms Z boosting + + + align:start position:0% +sort of major labor reforms Z boosting +if you will in the 1980s initially was a + + align:start position:0% +if you will in the 1980s initially was a + + + align:start position:0% +if you will in the 1980s initially was a +great deal for workers real wages went + + align:start position:0% +great deal for workers real wages went + + + align:start position:0% +great deal for workers real wages went +up and so on it was wonderful but + + align:start position:0% +up and so on it was wonderful but + + + align:start position:0% +up and so on it was wonderful but +eventually with the passage of time they + + align:start position:0% +eventually with the passage of time they + + + align:start position:0% +eventually with the passage of time they +end up just with a much higher real not + + align:start position:0% +end up just with a much higher real not + + + align:start position:0% +end up just with a much higher real not +a much higher real wage but a much + + align:start position:0% +a much higher real wage but a much + + + align:start position:0% +a much higher real wage but a much +higher real unemployment rate okay they + + align:start position:0% +higher real unemployment rate okay they + + + align:start position:0% +higher real unemployment rate okay they +went + + align:start position:0% +went + + + align:start position:0% +went +from single digit low single digits to + + align:start position:0% +from single digit low single digits to + + + align:start position:0% +from single digit low single digits to +you know 15% unemployment rates and + + align:start position:0% +you know 15% unemployment rates and + + + align:start position:0% +you know 15% unemployment rates and +things like that and since then they + + align:start position:0% +things like that and since then they + + + align:start position:0% +things like that and since then they +have been sort of reforming the labor + + align:start position:0% +have been sort of reforming the labor + + + align:start position:0% +have been sort of reforming the labor +market to fix some of that but but + + align:start position:0% +market to fix some of that but but + + + align:start position:0% +market to fix some of that but but +that's that's that was very much what + + align:start position:0% +that's that's that was very much what + + + align:start position:0% +that's that's that was very much what +happened in Continental Europe in the + + align:start position:0% +happened in Continental Europe in the + + + align:start position:0% +happened in Continental Europe in the +80s this is the case of am marup + + align:start position:0% +80s this is the case of am marup + + + align:start position:0% +80s this is the case of am marup +increase is the other one I described no + + align:start position:0% +increase is the other one I described no + + + align:start position:0% +increase is the other one I described no +so if if markups go up then ini that + + align:start position:0% +so if if markups go up then ini that + + + align:start position:0% +so if if markups go up then ini that +means firms in equilibrium are not + + align:start position:0% +means firms in equilibrium are not + + + align:start position:0% +means firms in equilibrium are not +willing to pay real + + align:start position:0% +willing to pay real + + + align:start position:0% +willing to pay real +wages they want to pay a lower real wage + + align:start position:0% +wages they want to pay a lower real wage + + + align:start position:0% +wages they want to pay a lower real wage +well at this level of unemployment + + align:start position:0% +well at this level of unemployment + + + align:start position:0% +well at this level of unemployment +workers are not going to take it the + + align:start position:0% +workers are not going to take it the + + + align:start position:0% +workers are not going to take it the +only thing that will restore equilibrium + + align:start position:0% +only thing that will restore equilibrium + + + align:start position:0% +only thing that will restore equilibrium +is that the natural rate of unemployment + + align:start position:0% +is that the natural rate of unemployment + + + align:start position:0% +is that the natural rate of unemployment +goes up that weakens the hand of workers + + align:start position:0% +goes up that weakens the hand of workers + + + align:start position:0% +goes up that weakens the hand of workers +and you end up with this and again + + align:start position:0% +and you end up with this and again + + + align:start position:0% +and you end up with this and again +there's nothing natural about this I'm + + align:start position:0% +there's nothing natural about this I'm + + + align:start position:0% +there's nothing natural about this I'm +not saying this is good bad I have no + + align:start position:0% +not saying this is good bad I have no + + + align:start position:0% +not saying this is good bad I have no +idea why the markets went up if it just + + align:start position:0% +idea why the markets went up if it just + + + align:start position:0% +idea why the markets went up if it just +imperfect competition going up that's + + align:start position:0% +imperfect competition going up that's + + + align:start position:0% +imperfect competition going up that's +clearly not a good thing but it may have + + align:start position:0% +clearly not a good thing but it may have + + + align:start position:0% +clearly not a good thing but it may have +in something else the price of oil went + + align:start position:0% +in something else the price of oil went + + + align:start position:0% +in something else the price of oil went +up a lot I don't know was a war + + align:start position:0% +up a lot I don't know was a war + + + align:start position:0% +up a lot I don't know was a war +somewhere and then productivity CES down + + align:start position:0% +somewhere and then productivity CES down + + + align:start position:0% +somewhere and then productivity CES down +some something of that kind so I don't + + align:start position:0% +some something of that kind so I don't + + + align:start position:0% +some something of that kind so I don't +know what it did but but the only thing + + align:start position:0% +know what it did but but the only thing + + + align:start position:0% +know what it did but but the only thing +I'm describing here is the + + align:start position:0% +I'm describing here is the + + + align:start position:0% +I'm describing here is the +mechanics + + align:start position:0% +mechanics + + + align:start position:0% +mechanics +okay + + align:start position:0% +okay + + + align:start position:0% +okay +good + + align:start position:0% +good + + + align:start position:0% +good +so er the quiz is up to here right so + + align:start position:0% +so er the quiz is up to here right so + + + align:start position:0% +so er the quiz is up to here right so +the the quiz ends here okay in the next + + align:start position:0% +the the quiz ends here okay in the next + + + align:start position:0% +the the quiz ends here okay in the next +lecture we're going I'm going to start + + align:start position:0% +lecture we're going I'm going to start + + + align:start position:0% +lecture we're going I'm going to start +the Philips curve which is now using + + align:start position:0% +the Philips curve which is now using + + + align:start position:0% +the Philips curve which is now using +this model but looking at deviations + + align:start position:0% +this model but looking at deviations + + + align:start position:0% +this model but looking at deviations +situations where the price is not equal + + align:start position:0% +situations where the price is not equal + + + align:start position:0% +situations where the price is not equal +to expected price or expect the price is + + align:start position:0% +to expected price or expect the price is + + + align:start position:0% +to expected price or expect the price is +not equal to to to the actual price and + + align:start position:0% +not equal to to to the actual price and + + + align:start position:0% +not equal to to to the actual price and +that's going to lead to interesting + + align:start position:0% +that's going to lead to interesting + + + align:start position:0% +that's going to lead to interesting +situations H and there we're going to be + + align:start position:0% +situations H and there we're going to be + + + align:start position:0% +situations H and there we're going to be +talking about inflation here this is not + + align:start position:0% +talking about inflation here this is not + + + align:start position:0% +talking about inflation here this is not +a model to talk about inflation I'm + + align:start position:0% +a model to talk about inflation I'm + + + align:start position:0% +a model to talk about inflation I'm +talking about what happens in the medium + + align:start position:0% +talking about what happens in the medium + + + align:start position:0% +talking about what happens in the medium +run I haven't told you whether the + + align:start position:0% +run I haven't told you whether the + + + align:start position:0% +run I haven't told you whether the +adjustment happens through the nominal + + align:start position:0% +adjustment happens through the nominal + + + align:start position:0% +adjustment happens through the nominal +wage through the prices or what I mean + + align:start position:0% +wage through the prices or what I mean + + + align:start position:0% +wage through the prices or what I mean +there are many ways of reaching the same + + align:start position:0% +there are many ways of reaching the same + + + align:start position:0% +there are many ways of reaching the same +real wage you know you could have it you + + align:start position:0% +real wage you know you could have it you + + + align:start position:0% +real wage you know you could have it you +could you could lower your wages by + + align:start position:0% +could you could lower your wages by + + + align:start position:0% +could you could lower your wages by +increasing H wages by 50% and prices by + + align:start position:0% +increasing H wages by 50% and prices by + + + align:start position:0% +increasing H wages by 50% and prices by +60 say no or you could do it by you know + + align:start position:0% +60 say no or you could do it by you know + + + align:start position:0% +60 say no or you could do it by you know +lowering nominal wages by 10 and not + + align:start position:0% +lowering nominal wages by 10 and not + + + align:start position:0% +lowering nominal wages by 10 and not +moving prices so there are many ways of + + align:start position:0% +moving prices so there are many ways of + + + align:start position:0% +moving prices so there are many ways of +doing it the Philips C is going allow us + + align:start position:0% +doing it the Philips C is going allow us + + + align:start position:0% +doing it the Philips C is going allow us +to to get into that part but it's not + + align:start position:0% +to to get into that part but it's not + + + align:start position:0% +to to get into that part but it's not +going to be part of your quiz the quiz + + align:start position:0% +going to be part of your quiz the quiz + + + align:start position:0% +going to be part of your quiz the quiz +that's going to be part of of the second + + align:start position:0% +that's going to be part of of the second + + + align:start position:0% +that's going to be part of of the second +quiz so in the next lecture I'm going to + + align:start position:0% +quiz so in the next lecture I'm going to + + + align:start position:0% +quiz so in the next lecture I'm going to +talk about the Philips curve and then on + + align:start position:0% +talk about the Philips curve and then on + + + align:start position:0% +talk about the Philips curve and then on +Wednesday a review and and then you have + + align:start position:0% +Wednesday a review and and then you have + + + align:start position:0% +Wednesday a review and and then you have +the quiz + + align:start position:0% + + + + align:start position:0% + +okay for \ No newline at end of file diff --git a/oxPhYmQdwaQ.txt b/oxPhYmQdwaQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..9b425583d52c9b462cf144153ec9b97f7903adc5 --- /dev/null +++ b/oxPhYmQdwaQ.txt @@ -0,0 +1,5587 @@ +align:start position:0% + +how is Africa mate I mean how has it + + align:start position:0% +how is Africa mate I mean how has it + + + align:start position:0% +how is Africa mate I mean how has it +been made to mean and what is associated + + align:start position:0% +been made to mean and what is associated + + + align:start position:0% +been made to mean and what is associated +with this idea of a freaking I mean it's + + align:start position:0% +with this idea of a freaking I mean it's + + + align:start position:0% +with this idea of a freaking I mean it's +weird to talk about it as this one plays + + align:start position:0% +weird to talk about it as this one plays + + + align:start position:0% +weird to talk about it as this one plays +that's exactly the point how is it that + + align:start position:0% +that's exactly the point how is it that + + + align:start position:0% +that's exactly the point how is it that +we've come to talk about Africa as a + + align:start position:0% +we've come to talk about Africa as a + + + align:start position:0% +we've come to talk about Africa as a +thing a place in the world when in fact + + align:start position:0% +thing a place in the world when in fact + + + align:start position:0% +thing a place in the world when in fact +you know it includes 50 over 50 + + align:start position:0% +you know it includes 50 over 50 + + + align:start position:0% +you know it includes 50 over 50 +countries thousands of languages + + align:start position:0% +countries thousands of languages + + + align:start position:0% +countries thousands of languages +millions of people right today in the + + align:start position:0% +millions of people right today in the + + + align:start position:0% +millions of people right today in the +podcast a conversation about teaching a + + align:start position:0% +podcast a conversation about teaching a + + + align:start position:0% +podcast a conversation about teaching a +categorically misunderstood concept + + align:start position:0% +categorically misunderstood concept + + + align:start position:0% +categorically misunderstood concept +Africa + + align:start position:0% +Africa + + + align:start position:0% +Africa +our guest today found inspiration for + + align:start position:0% +our guest today found inspiration for + + + align:start position:0% +our guest today found inspiration for +bold new ways of teaching through her + + align:start position:0% +bold new ways of teaching through her + + + align:start position:0% +bold new ways of teaching through her +own experiences as a student she + + align:start position:0% +own experiences as a student she + + + align:start position:0% +own experiences as a student she +recognized throughout her education the + + align:start position:0% +recognized throughout her education the + + + align:start position:0% +recognized throughout her education the +ability for teachers to empower or + + align:start position:0% +ability for teachers to empower or + + + align:start position:0% +ability for teachers to empower or +inhibit their students what's made the + + align:start position:0% +inhibit their students what's made the + + + align:start position:0% +inhibit their students what's made the +biggest difference for me in the + + align:start position:0% +biggest difference for me in the + + + align:start position:0% +biggest difference for me in the +classroom as a student has been + + align:start position:0% +classroom as a student has been + + + align:start position:0% +classroom as a student has been +instructors who made me feel like I had + + align:start position:0% +instructors who made me feel like I had + + + align:start position:0% +instructors who made me feel like I had +something to offer and the lack of that + + align:start position:0% +something to offer and the lack of that + + + align:start position:0% +something to offer and the lack of that +does a lot of damage me when have having + + align:start position:0% +does a lot of damage me when have having + + + align:start position:0% +does a lot of damage me when have having +instructors and make you feel like you + + align:start position:0% +instructors and make you feel like you + + + align:start position:0% +instructors and make you feel like you +have nothing to offer it that's actually + + align:start position:0% +have nothing to offer it that's actually + + + align:start position:0% +have nothing to offer it that's actually +damaging it's not just neutralized + + align:start position:0% +damaging it's not just neutralized + + + align:start position:0% +damaging it's not just neutralized +damaging so it's really important for me + + align:start position:0% +damaging so it's really important for me + + + align:start position:0% +damaging so it's really important for me +to sort of valorized students voices and + + align:start position:0% +to sort of valorized students voices and + + + align:start position:0% +to sort of valorized students voices and +to show them that they're doing it + + align:start position:0% +to show them that they're doing it + + + align:start position:0% +to show them that they're doing it +welcome to chalk radio a podcast about + + align:start position:0% +welcome to chalk radio a podcast about + + + align:start position:0% +welcome to chalk radio a podcast about +inspired teaching at MIT + + align:start position:0% +inspired teaching at MIT + + + align:start position:0% +inspired teaching at MIT +I'm your host Sarah Hansen from MIT + + align:start position:0% +I'm your host Sarah Hansen from MIT + + + align:start position:0% +I'm your host Sarah Hansen from MIT +OpenCourseWare in this episode I take + + align:start position:0% +OpenCourseWare in this episode I take + + + align:start position:0% +OpenCourseWare in this episode I take +you with me to meet Amma Edo an + + align:start position:0% +you with me to meet Amma Edo an + + + align:start position:0% +you with me to meet Amma Edo an +assistant professor of African Studies + + align:start position:0% +assistant professor of African Studies + + + align:start position:0% +assistant professor of African Studies +at MIT professor Eidos research centers + + align:start position:0% +at MIT professor Eidos research centers + + + align:start position:0% +at MIT professor Eidos research centers +around the complex array of cultures + + align:start position:0% +around the complex array of cultures + + + align:start position:0% +around the complex array of cultures +traditions nations and ideas known as + + align:start position:0% +traditions nations and ideas known as + + + align:start position:0% +traditions nations and ideas known as +Africa and how Africa as a concept is + + align:start position:0% +Africa and how Africa as a concept is + + + align:start position:0% +Africa and how Africa as a concept is +produced through material practices + + align:start position:0% +produced through material practices + + + align:start position:0% +produced through material practices +things like music ritual performance and + + align:start position:0% +things like music ritual performance and + + + align:start position:0% +things like music ritual performance and +dress will learn how she engages + + align:start position:0% +dress will learn how she engages + + + align:start position:0% +dress will learn how she engages +students in unpacking the concept of + + align:start position:0% +students in unpacking the concept of + + + align:start position:0% +students in unpacking the concept of +Africa through the very creative + + align:start position:0% +Africa through the very creative + + + align:start position:0% +Africa through the very creative +practices that make it so what does it + + align:start position:0% +practices that make it so what does it + + + align:start position:0% +practices that make it so what does it +look like to challenge the meaning we've + + align:start position:0% +look like to challenge the meaning we've + + + align:start position:0% +look like to challenge the meaning we've +prescribed to a place as rich and + + align:start position:0% +prescribed to a place as rich and + + + align:start position:0% +prescribed to a place as rich and +diverse as Africa we'll pick up our + + align:start position:0% +diverse as Africa we'll pick up our + + + align:start position:0% +diverse as Africa we'll pick up our +conversation with professor Eddowes + + align:start position:0% +conversation with professor Eddowes + + + align:start position:0% +conversation with professor Eddowes +explanation you know we were used to + + align:start position:0% +explanation you know we were used to + + + align:start position:0% +explanation you know we were used to +speaking of Africa as a place and not + + align:start position:0% +speaking of Africa as a place and not + + + align:start position:0% +speaking of Africa as a place and not +just any place but a place that's + + align:start position:0% +just any place but a place that's + + + align:start position:0% +just any place but a place that's +burdened with + + align:start position:0% +burdened with + + + align:start position:0% +burdened with +a lot of ideas and values that + + align:start position:0% +a lot of ideas and values that + + + align:start position:0% +a lot of ideas and values that +historically have been negative to put + + align:start position:0% +historically have been negative to put + + + align:start position:0% +historically have been negative to put +it simply and so what my research and my + + align:start position:0% +it simply and so what my research and my + + + align:start position:0% +it simply and so what my research and my +teaching centers on is about + + align:start position:0% +teaching centers on is about + + + align:start position:0% +teaching centers on is about +interrogating that so first making + + align:start position:0% +interrogating that so first making + + + align:start position:0% +interrogating that so first making +visible the ways that Africa is made to + + align:start position:0% +visible the ways that Africa is made to + + + align:start position:0% +visible the ways that Africa is made to +mean so that's what I mean with Africa + + align:start position:0% +mean so that's what I mean with Africa + + + align:start position:0% +mean so that's what I mean with Africa +as a category of thought to understand + + align:start position:0% +as a category of thought to understand + + + align:start position:0% +as a category of thought to understand +that Africa means more than just this + + align:start position:0% +that Africa means more than just this + + + align:start position:0% +that Africa means more than just this +geographical space you know it's also + + align:start position:0% +geographical space you know it's also + + + align:start position:0% +geographical space you know it's also +all these countries and all this is very + + align:start position:0% +all these countries and all this is very + + + align:start position:0% +all these countries and all this is very +complicated history but then to see the + + align:start position:0% +complicated history but then to see the + + + align:start position:0% +complicated history but then to see the +ways that this valence that Africa + + align:start position:0% +ways that this valence that Africa + + + align:start position:0% +ways that this valence that Africa +quote-unquote has the way that that + + align:start position:0% +quote-unquote has the way that that + + + align:start position:0% +quote-unquote has the way that that +plays out in all aspects of life really + + align:start position:0% +plays out in all aspects of life really + + + align:start position:0% +plays out in all aspects of life really +so broadly speaking this is like this + + align:start position:0% +so broadly speaking this is like this + + + align:start position:0% +so broadly speaking this is like this +question of thinking about Africa's + + align:start position:0% +question of thinking about Africa's + + + align:start position:0% +question of thinking about Africa's +category of thought is understanding the + + align:start position:0% +category of thought is understanding the + + + align:start position:0% +category of thought is understanding the +politics that are involved in engaging + + align:start position:0% +politics that are involved in engaging + + + align:start position:0% +politics that are involved in engaging +with the continent and an intellectual + + align:start position:0% +with the continent and an intellectual + + + align:start position:0% +with the continent and an intellectual +man or politically and so on in this + + align:start position:0% +man or politically and so on in this + + + align:start position:0% +man or politically and so on in this +course we use creative practices the + + align:start position:0% +course we use creative practices the + + + align:start position:0% +course we use creative practices the +arts popular culture as a way in for two + + align:start position:0% +arts popular culture as a way in for two + + + align:start position:0% +arts popular culture as a way in for two +reasons one because there's a way that + + align:start position:0% +reasons one because there's a way that + + + align:start position:0% +reasons one because there's a way that +you know I don't I'm not crazy about the + + align:start position:0% +you know I don't I'm not crazy about the + + + align:start position:0% +you know I don't I'm not crazy about the +term popular culture because it's a way + + align:start position:0% +term popular culture because it's a way + + + align:start position:0% +term popular culture because it's a way +that it seems to devalue it and it's + + align:start position:0% +that it seems to devalue it and it's + + + align:start position:0% +that it seems to devalue it and it's +just you know kind of fun yet it + + align:start position:0% +just you know kind of fun yet it + + + align:start position:0% +just you know kind of fun yet it +animates so much of our daily + + align:start position:0% +animates so much of our daily + + + align:start position:0% +animates so much of our daily +experiences no matter who you are in no + + align:start position:0% +experiences no matter who you are in no + + + align:start position:0% +experiences no matter who you are in no +matter where you are in the world so on + + align:start position:0% +matter where you are in the world so on + + + align:start position:0% +matter where you are in the world so on +one hand the purpose of their goal of + + align:start position:0% +one hand the purpose of their goal of + + + align:start position:0% +one hand the purpose of their goal of +using this as a way into asking these + + align:start position:0% +using this as a way into asking these + + + align:start position:0% +using this as a way into asking these +more kind of theoretical and + + align:start position:0% +more kind of theoretical and + + + align:start position:0% +more kind of theoretical and +philosophical questions about Africa as + + align:start position:0% +philosophical questions about Africa as + + + align:start position:0% +philosophical questions about Africa as +a category of thought is to recognize + + align:start position:0% +a category of thought is to recognize + + + align:start position:0% +a category of thought is to recognize +that these everyday practices are + + align:start position:0% +that these everyday practices are + + + align:start position:0% +that these everyday practices are +actually extremely rich and extremely + + align:start position:0% +actually extremely rich and extremely + + + align:start position:0% +actually extremely rich and extremely +and just as political as any other form + + align:start position:0% +and just as political as any other form + + + align:start position:0% +and just as political as any other form +of engagement but then more specifically + + align:start position:0% +of engagement but then more specifically + + + align:start position:0% +of engagement but then more specifically +to Africa is the fact that right now you + + align:start position:0% +to Africa is the fact that right now you + + + align:start position:0% +to Africa is the fact that right now you +know Africa is sort of having this + + align:start position:0% +know Africa is sort of having this + + + align:start position:0% +know Africa is sort of having this +moment where it's signification is + + align:start position:0% +moment where it's signification is + + + align:start position:0% +moment where it's signification is +appearing to shift part of is + + align:start position:0% +appearing to shift part of is + + + align:start position:0% +appearing to shift part of is +understanding whether it's actually + + align:start position:0% +understanding whether it's actually + + + align:start position:0% +understanding whether it's actually +shifting but we're you know this all the + + align:start position:0% +shifting but we're you know this all the + + + align:start position:0% +shifting but we're you know this all the +stories we had about the continent used + + align:start position:0% +stories we had about the continent used + + + align:start position:0% +stories we had about the continent used +to be about war and disease and famine + + align:start position:0% +to be about war and disease and famine + + + align:start position:0% +to be about war and disease and famine +and dysfunction simply speaking now + + align:start position:0% +and dysfunction simply speaking now + + + align:start position:0% +and dysfunction simply speaking now +there's also another discourse where + + align:start position:0% +there's also another discourse where + + + align:start position:0% +there's also another discourse where +Africa is hot + + align:start position:0% +Africa is hot + + + align:start position:0% +Africa is hot +Africa is sort of the future Africa is + + align:start position:0% +Africa is sort of the future Africa is + + + align:start position:0% +Africa is sort of the future Africa is +where all of these new possibilities are + + align:start position:0% +where all of these new possibilities are + + + align:start position:0% +where all of these new possibilities are +playing out so whether it's or within + + align:start position:0% +playing out so whether it's or within + + + align:start position:0% +playing out so whether it's or within +the the business realm or it's or within + + align:start position:0% +the the business realm or it's or within + + + align:start position:0% +the the business realm or it's or within +the arts or that's this idea that Africa + + align:start position:0% +the arts or that's this idea that Africa + + + align:start position:0% +the arts or that's this idea that Africa +is the last frontier so there's a way + + align:start position:0% +is the last frontier so there's a way + + + align:start position:0% +is the last frontier so there's a way +that Africa's + + align:start position:0% +that Africa's + + + align:start position:0% +that Africa's +got a new prominence on the global stage + + align:start position:0% +got a new prominence on the global stage + + + align:start position:0% +got a new prominence on the global stage +and that a lot of that is playing out in + + align:start position:0% +and that a lot of that is playing out in + + + align:start position:0% +and that a lot of that is playing out in +the realm of what I call creative + + align:start position:0% +the realm of what I call creative + + + align:start position:0% +the realm of what I call creative +practice so the arts and popular culture + + align:start position:0% +practice so the arts and popular culture + + + align:start position:0% +practice so the arts and popular culture +and that's why it's I thought that it + + align:start position:0% +and that's why it's I thought that it + + + align:start position:0% +and that's why it's I thought that it +would be a particularly good angle to + + align:start position:0% +would be a particularly good angle to + + + align:start position:0% +would be a particularly good angle to +take in addressing these sort of lofty + + align:start position:0% +take in addressing these sort of lofty + + + align:start position:0% +take in addressing these sort of lofty +or questions and seeing the ways that + + align:start position:0% +or questions and seeing the ways that + + + align:start position:0% +or questions and seeing the ways that +they play out in the day-to-day and also + + align:start position:0% +they play out in the day-to-day and also + + + align:start position:0% +they play out in the day-to-day and also +through beautiful and pleasant objects + + align:start position:0% +through beautiful and pleasant objects + + + align:start position:0% +through beautiful and pleasant objects +and pleasant things to engage with + + align:start position:0% +and pleasant things to engage with + + + align:start position:0% +and pleasant things to engage with +things that are moving and that are + + align:start position:0% +things that are moving and that are + + + align:start position:0% +things that are moving and that are +inspiring which i think opens us up to + + align:start position:0% +inspiring which i think opens us up to + + + align:start position:0% +inspiring which i think opens us up to +to thinking and to processing + + align:start position:0% +to thinking and to processing + + + align:start position:0% +to thinking and to processing +differently when we moved in this other + + align:start position:0% +differently when we moved in this other + + + align:start position:0% +differently when we moved in this other +this other way it makes me wonder how + + align:start position:0% +this other way it makes me wonder how + + + align:start position:0% +this other way it makes me wonder how +this specific case of looking at Africa + + align:start position:0% +this specific case of looking at Africa + + + align:start position:0% +this specific case of looking at Africa +as a category of thought and looking at + + align:start position:0% +as a category of thought and looking at + + + align:start position:0% +as a category of thought and looking at +creative practices like did it open for + + align:start position:0% +creative practices like did it open for + + + align:start position:0% +creative practices like did it open for +students new ways of seeing the world in + + align:start position:0% +students new ways of seeing the world in + + + align:start position:0% +students new ways of seeing the world in +general like does this kind of teaching + + align:start position:0% +general like does this kind of teaching + + + align:start position:0% +general like does this kind of teaching +offer new pathways for critical thinking + + align:start position:0% +offer new pathways for critical thinking + + + align:start position:0% +offer new pathways for critical thinking +that's applicable in many fields I'd + + align:start position:0% +that's applicable in many fields I'd + + + align:start position:0% +that's applicable in many fields I'd +hope so I mean my god that's like that's + + align:start position:0% +hope so I mean my god that's like that's + + + align:start position:0% +hope so I mean my god that's like that's +our dream as educators right that + + align:start position:0% +our dream as educators right that + + + align:start position:0% +our dream as educators right that +anything that whatever we do in the + + align:start position:0% +anything that whatever we do in the + + + align:start position:0% +anything that whatever we do in the +classroom and it's very limited setting + + align:start position:0% +classroom and it's very limited setting + + + align:start position:0% +classroom and it's very limited setting +or in this limited scale manifests or + + align:start position:0% +or in this limited scale manifests or + + + align:start position:0% +or in this limited scale manifests or +for our students that they're able to + + align:start position:0% +for our students that they're able to + + + align:start position:0% +for our students that they're able to +take it into their experiences way + + align:start position:0% +take it into their experiences way + + + align:start position:0% +take it into their experiences way +beyond the classroom and beyond the + + align:start position:0% +beyond the classroom and beyond the + + + align:start position:0% +beyond the classroom and beyond the +specific topic of the course when I + + align:start position:0% +specific topic of the course when I + + + align:start position:0% +specific topic of the course when I +think about the students that I had in + + align:start position:0% +think about the students that I had in + + + align:start position:0% +think about the students that I had in +the class last year it was about 12 + + align:start position:0% +the class last year it was about 12 + + + align:start position:0% +the class last year it was about 12 +students and about half of them were + + align:start position:0% +students and about half of them were + + + align:start position:0% +students and about half of them were +African or of so Africans of different + + align:start position:0% +African or of so Africans of different + + + align:start position:0% +African or of so Africans of different +varieties so Africans from the continent + + align:start position:0% +varieties so Africans from the continent + + + align:start position:0% +varieties so Africans from the continent +Africans were first-generation Americans + + align:start position:0% +Africans were first-generation Americans + + + align:start position:0% +Africans were first-generation Americans +and then the other half were American of + + align:start position:0% +and then the other half were American of + + + align:start position:0% +and then the other half were American of +varying ethnicities and I would say that + + align:start position:0% +varying ethnicities and I would say that + + + align:start position:0% +varying ethnicities and I would say that +for all of them is well certainly for my + + align:start position:0% +for all of them is well certainly for my + + + align:start position:0% +for all of them is well certainly for my +African students it was a way that they + + align:start position:0% +African students it was a way that they + + + align:start position:0% +African students it was a way that they +I think it's safe to say we're kind of + + align:start position:0% +I think it's safe to say we're kind of + + + align:start position:0% +I think it's safe to say we're kind of +weren't there because they were + + align:start position:0% +weren't there because they were + + + align:start position:0% +weren't there because they were +interested in engaging with this part of + + align:start position:0% +interested in engaging with this part of + + + align:start position:0% +interested in engaging with this part of +their experience in a different realm to + + align:start position:0% +their experience in a different realm to + + + align:start position:0% +their experience in a different realm to +actually study it in the classroom + + align:start position:0% +actually study it in the classroom + + + align:start position:0% +actually study it in the classroom +instead of it just being kind of what + + align:start position:0% +instead of it just being kind of what + + + align:start position:0% +instead of it just being kind of what +they are immersed in and their + + align:start position:0% +they are immersed in and their + + + align:start position:0% +they are immersed in and their +day-to-day lives in their back home and + + align:start position:0% +day-to-day lives in their back home and + + + align:start position:0% +day-to-day lives in their back home and +so on and for the non African students + + align:start position:0% +so on and for the non African students + + + align:start position:0% +so on and for the non African students +some of them were going to be working on + + align:start position:0% +some of them were going to be working on + + + align:start position:0% +some of them were going to be working on +in Africa on this during the summer or + + align:start position:0% +in Africa on this during the summer or + + + align:start position:0% +in Africa on this during the summer or +had just come back from being on the + + align:start position:0% +had just come back from being on the + + + align:start position:0% +had just come back from being on the +continent and just wanted to kind of + + align:start position:0% +continent and just wanted to kind of + + + align:start position:0% +continent and just wanted to kind of +learn more general + + align:start position:0% +learn more general + + + align:start position:0% +learn more general +about the continent so so what extent + + align:start position:0% +about the continent so so what extent + + + align:start position:0% +about the continent so so what extent +did being in the class broaden their + + align:start position:0% +did being in the class broaden their + + + align:start position:0% +did being in the class broaden their +perspectives or kind of give them tools + + align:start position:0% +perspectives or kind of give them tools + + + align:start position:0% +perspectives or kind of give them tools +that they could use beyond the specific + + align:start position:0% +that they could use beyond the specific + + + align:start position:0% +that they could use beyond the specific +topic after the class I think the class + + align:start position:0% +topic after the class I think the class + + + align:start position:0% +topic after the class I think the class +might have helped them get language for + + align:start position:0% +might have helped them get language for + + + align:start position:0% +might have helped them get language for +to articulate some of these questions + + align:start position:0% +to articulate some of these questions + + + align:start position:0% +to articulate some of these questions +about power essentially and if not + + align:start position:0% +about power essentially and if not + + + align:start position:0% +about power essentially and if not +always to find answers to at least be + + align:start position:0% +always to find answers to at least be + + + align:start position:0% +always to find answers to at least be +able to notice patterns and and sort of + + align:start position:0% +able to notice patterns and and sort of + + + align:start position:0% +able to notice patterns and and sort of +describe what they're seeing so often + + align:start position:0% +describe what they're seeing so often + + + align:start position:0% +describe what they're seeing so often +you know we have a feeling that + + align:start position:0% +you know we have a feeling that + + + align:start position:0% +you know we have a feeling that +something's all right or that there's + + align:start position:0% +something's all right or that there's + + + align:start position:0% +something's all right or that there's +something going on here but we don't + + align:start position:0% +something going on here but we don't + + + align:start position:0% +something going on here but we don't +quite have the language for it and I + + align:start position:0% +quite have the language for it and I + + + align:start position:0% +quite have the language for it and I +think that that's what a class like this + + align:start position:0% +think that that's what a class like this + + + align:start position:0% +think that that's what a class like this +aims to do is to give students language + + align:start position:0% +aims to do is to give students language + + + align:start position:0% +aims to do is to give students language +to articulate these things that they + + align:start position:0% +to articulate these things that they + + + align:start position:0% +to articulate these things that they +might be picking up on in different ways + + align:start position:0% + + + + align:start position:0% + +so what does it look like to empower + + align:start position:0% +so what does it look like to empower + + + align:start position:0% +so what does it look like to empower +students to follow a feeling to develop + + align:start position:0% +students to follow a feeling to develop + + + align:start position:0% +students to follow a feeling to develop +the language to negotiate that feeling + + align:start position:0% +the language to negotiate that feeling + + + align:start position:0% +the language to negotiate that feeling +into theory so we met once a week and we + + align:start position:0% +into theory so we met once a week and we + + + align:start position:0% +into theory so we met once a week and we +focus each session on a different form + + align:start position:0% +focus each session on a different form + + + align:start position:0% +focus each session on a different form +of cultural production um or a different + + align:start position:0% +of cultural production um or a different + + + align:start position:0% +of cultural production um or a different +theme so we had performance and then + + align:start position:0% +theme so we had performance and then + + + align:start position:0% +theme so we had performance and then +within performance your performance as + + align:start position:0% +within performance your performance as + + + align:start position:0% +within performance your performance as +stress and then we had literature and we + + align:start position:0% +stress and then we had literature and we + + + align:start position:0% +stress and then we had literature and we +had film and we had what a science and + + align:start position:0% +had film and we had what a science and + + + align:start position:0% +had film and we had what a science and +technology and so for each unit new + + align:start position:0% +technology and so for each unit new + + + align:start position:0% +technology and so for each unit new +questions came up but the thread I cut + + align:start position:0% +questions came up but the thread I cut + + + align:start position:0% +questions came up but the thread I cut +across them was the same I which was a + + align:start position:0% +across them was the same I which was a + + + align:start position:0% +across them was the same I which was a +question of how is Africa being made to + + align:start position:0% +question of how is Africa being made to + + + align:start position:0% +question of how is Africa being made to +mean in the world and how our African + + align:start position:0% +mean in the world and how our African + + + align:start position:0% +mean in the world and how our African +cultural producers engaging in that + + align:start position:0% +cultural producers engaging in that + + + align:start position:0% +cultural producers engaging in that +process of making Africa I mean through + + align:start position:0% +process of making Africa I mean through + + + align:start position:0% +process of making Africa I mean through +their practice and of course and the + + align:start position:0% +their practice and of course and the + + + align:start position:0% +their practice and of course and the +questions that come up about are like + + align:start position:0% +questions that come up about are like + + + align:start position:0% +questions that come up about are like +what are the specific issues that arise + + align:start position:0% +what are the specific issues that arise + + + align:start position:0% +what are the specific issues that arise +with this particular form of cultural + + align:start position:0% +with this particular form of cultural + + + align:start position:0% +with this particular form of cultural +production right so for theatre what + + align:start position:0% +production right so for theatre what + + + align:start position:0% +production right so for theatre what +does it mean for instance to produce a + + align:start position:0% +does it mean for instance to produce a + + + align:start position:0% +does it mean for instance to produce a +play for an audience in Nigeria to come + + align:start position:0% +play for an audience in Nigeria to come + + + align:start position:0% +play for an audience in Nigeria to come +perform that play in Cambridge + + align:start position:0% +perform that play in Cambridge + + + align:start position:0% +perform that play in Cambridge +Massachusetts what are the politics and + + align:start position:0% +Massachusetts what are the politics and + + + align:start position:0% +Massachusetts what are the politics and +that what are the questions that come up + + align:start position:0% +that what are the questions that come up + + + align:start position:0% +that what are the questions that come up +in carrying this object from one space + + align:start position:0% +in carrying this object from one space + + + align:start position:0% +in carrying this object from one space +into the next the goal was to both + + align:start position:0% +into the next the goal was to both + + + align:start position:0% +into the next the goal was to both +reflect through each of these cases this + + align:start position:0% +reflect through each of these cases this + + + align:start position:0% +reflect through each of these cases this +underlying question that the course was + + align:start position:0% +underlying question that the course was + + + align:start position:0% +underlying question that the course was +after but then to show the nuances or + + align:start position:0% +after but then to show the nuances or + + + align:start position:0% +after but then to show the nuances or +the specificities that + + align:start position:0% +the specificities that + + + align:start position:0% +the specificities that +apply to each particular form of + + align:start position:0% +apply to each particular form of + + + align:start position:0% +apply to each particular form of +creative production and then ultimately + + align:start position:0% +creative production and then ultimately + + + align:start position:0% +creative production and then ultimately +to say you know what do we gain by Chuck + + align:start position:0% +to say you know what do we gain by Chuck + + + align:start position:0% +to say you know what do we gain by Chuck +supposing these different things is + + align:start position:0% +supposing these different things is + + + align:start position:0% +supposing these different things is +there you know what can we learn about + + align:start position:0% +there you know what can we learn about + + + align:start position:0% +there you know what can we learn about +ideas of technological innovation in or + + align:start position:0% +ideas of technological innovation in or + + + align:start position:0% +ideas of technological innovation in or +for the continent by looking at them + + align:start position:0% +for the continent by looking at them + + + align:start position:0% +for the continent by looking at them +alongside the production of photographer + + align:start position:0% +alongside the production of photographer + + + align:start position:0% +alongside the production of photographer +ethnographic portraits in the 19th + + align:start position:0% +ethnographic portraits in the 19th + + + align:start position:0% +ethnographic portraits in the 19th +century in South Africa for instance is + + align:start position:0% +century in South Africa for instance is + + + align:start position:0% +century in South Africa for instance is +there a way that these two cases can + + align:start position:0% +there a way that these two cases can + + + align:start position:0% +there a way that these two cases can +elucidate one another and I think yes I + + align:start position:0% +elucidate one another and I think yes I + + + align:start position:0% +elucidate one another and I think yes I +mean there's a reason that you know I + + align:start position:0% +mean there's a reason that you know I + + + align:start position:0% +mean there's a reason that you know I +did it that way but yeah and I think + + align:start position:0% +did it that way but yeah and I think + + + align:start position:0% +did it that way but yeah and I think +that you know there was also another + + align:start position:0% +that you know there was also another + + + align:start position:0% +that you know there was also another +agenda behind it is that being at MIT in + + align:start position:0% +agenda behind it is that being at MIT in + + + align:start position:0% +agenda behind it is that being at MIT in +particular where we tend to fetishize + + align:start position:0% +particular where we tend to fetishize + + + align:start position:0% +particular where we tend to fetishize +technology and and consider it sometimes + + align:start position:0% +technology and and consider it sometimes + + + align:start position:0% +technology and and consider it sometimes +in the realm outside of other material + + align:start position:0% +in the realm outside of other material + + + align:start position:0% +in the realm outside of other material +practices other ways of knowing and of + + align:start position:0% +practices other ways of knowing and of + + + align:start position:0% +practices other ways of knowing and of +my personal one of my personal missions + + align:start position:0% +my personal one of my personal missions + + + align:start position:0% +my personal one of my personal missions +is to show that you know it's no + + align:start position:0% +is to show that you know it's no + + + align:start position:0% +is to show that you know it's no +different there's just different they're + + align:start position:0% +different there's just different they're + + + align:start position:0% +different there's just different they're +all objects they're all ways of doing + + align:start position:0% +all objects they're all ways of doing + + + align:start position:0% +all objects they're all ways of doing +they're all ways of knowing right so + + align:start position:0% +they're all ways of knowing right so + + + align:start position:0% +they're all ways of knowing right so +whether we're talking about plant + + align:start position:0% +whether we're talking about plant + + + align:start position:0% +whether we're talking about plant +healing or developing the next nano + + align:start position:0% +healing or developing the next nano + + + align:start position:0% +healing or developing the next nano +whatever we can think about these things + + align:start position:0% +whatever we can think about these things + + + align:start position:0% +whatever we can think about these things +next to each other no matter where + + align:start position:0% +next to each other no matter where + + + align:start position:0% +next to each other no matter where +they're happening and so I think the + + align:start position:0% +they're happening and so I think the + + + align:start position:0% +they're happening and so I think the +ways that case studies are useful is + + align:start position:0% +ways that case studies are useful is + + + align:start position:0% +ways that case studies are useful is +that they allow you to both kind of dig + + align:start position:0% +that they allow you to both kind of dig + + + align:start position:0% +that they allow you to both kind of dig +deep for that particular situation bring + + align:start position:0% +deep for that particular situation bring + + + align:start position:0% +deep for that particular situation bring +questions to the fore and then next time + + align:start position:0% +questions to the fore and then next time + + + align:start position:0% +questions to the fore and then next time +kind of consider the ways that those + + align:start position:0% +kind of consider the ways that those + + + align:start position:0% +kind of consider the ways that those +questions can apply or when new + + align:start position:0% +questions can apply or when new + + + align:start position:0% +questions can apply or when new +questions arise when you look at a + + align:start position:0% +questions arise when you look at a + + + align:start position:0% +questions arise when you look at a +different situation + + align:start position:0% +different situation + + + align:start position:0% +different situation +you mentioned performance and could you + + align:start position:0% +you mentioned performance and could you + + + align:start position:0% +you mentioned performance and could you +speak a little bit about how students + + align:start position:0% +speak a little bit about how students + + + align:start position:0% +speak a little bit about how students +attended performances out in the world + + align:start position:0% +attended performances out in the world + + + align:start position:0% +attended performances out in the world +as part of this course yeah you know so + + align:start position:0% +as part of this course yeah you know so + + + align:start position:0% +as part of this course yeah you know so +that kind of has to happen + + align:start position:0% +that kind of has to happen + + + align:start position:0% +that kind of has to happen +serendipitously um it just so happened + + align:start position:0% +serendipitously um it just so happened + + + align:start position:0% +serendipitously um it just so happened +to be that at the time that I was + + align:start position:0% +to be that at the time that I was + + + align:start position:0% +to be that at the time that I was +teaching this class this show came was I + + align:start position:0% +teaching this class this show came was I + + + align:start position:0% +teaching this class this show came was I +don't even remember how I found out + + align:start position:0% +don't even remember how I found out + + + align:start position:0% +don't even remember how I found out +about it I think from a mailing list or + + align:start position:0% +about it I think from a mailing list or + + + align:start position:0% +about it I think from a mailing list or +a friend told me I don't know that this + + align:start position:0% +a friend told me I don't know that this + + + align:start position:0% +a friend told me I don't know that this +display was coming to um to Harvard and + + align:start position:0% +display was coming to um to Harvard and + + + align:start position:0% +display was coming to um to Harvard and +similarly that Alan goomy's was gonna be + + align:start position:0% +similarly that Alan goomy's was gonna be + + + align:start position:0% +similarly that Alan goomy's was gonna be +coming to to Harvard also and I had so + + align:start position:0% +coming to to Harvard also and I had so + + + align:start position:0% +coming to to Harvard also and I had so +in the case of Van Gogh me + + align:start position:0% +in the case of Van Gogh me + + + align:start position:0% +in the case of Van Gogh me +just seen his film at a conference a few + + align:start position:0% +just seen his film at a conference a few + + + align:start position:0% +just seen his film at a conference a few +months before one of his films and + + align:start position:0% +months before one of his films and + + + align:start position:0% +months before one of his films and +absolutely adored it and so I'd wanted + + align:start position:0% +absolutely adored it and so I'd wanted + + + align:start position:0% +absolutely adored it and so I'd wanted +to teach it and it was an amazing + + align:start position:0% +to teach it and it was an amazing + + + align:start position:0% +to teach it and it was an amazing +opportunity to have them here and you + + align:start position:0% +opportunity to have them here and you + + + align:start position:0% +opportunity to have them here and you +know so that because you would also be + + align:start position:0% +know so that because you would also be + + + align:start position:0% +know so that because you would also be +speaking about the film and so in both + + align:start position:0% +speaking about the film and so in both + + + align:start position:0% +speaking about the film and so in both +cases it was an opportunity I saw these + + align:start position:0% +cases it was an opportunity I saw these + + + align:start position:0% +cases it was an opportunity I saw these +outings as an opportunity for students + + align:start position:0% +outings as an opportunity for students + + + align:start position:0% +outings as an opportunity for students +to UM to engage with these materials + + align:start position:0% +to UM to engage with these materials + + + align:start position:0% +to UM to engage with these materials +sort of in a more social way so it's one + + align:start position:0% +sort of in a more social way so it's one + + + align:start position:0% +sort of in a more social way so it's one +thing to be in your room and to just + + align:start position:0% +thing to be in your room and to just + + + align:start position:0% +thing to be in your room and to just +watch a film on your laptop it's a + + align:start position:0% +watch a film on your laptop it's a + + + align:start position:0% +watch a film on your laptop it's a +different thing to be an auditorium with + + align:start position:0% +different thing to be an auditorium with + + + align:start position:0% +different thing to be an auditorium with +various kinds of people to kind of pick + + align:start position:0% +various kinds of people to kind of pick + + + align:start position:0% +various kinds of people to kind of pick +up on the energy that's around you how + + align:start position:0% +up on the energy that's around you how + + + align:start position:0% +up on the energy that's around you how +people have other people around you are + + align:start position:0% +people have other people around you are + + + align:start position:0% +people have other people around you are +responding to different parts of the + + align:start position:0% +responding to different parts of the + + + align:start position:0% +responding to different parts of the +film right that's part of the experience + + align:start position:0% +film right that's part of the experience + + + align:start position:0% +film right that's part of the experience +also not to mention that to hear the + + align:start position:0% +also not to mention that to hear the + + + align:start position:0% +also not to mention that to hear the +filmmaker tell you what they were + + align:start position:0% +filmmaker tell you what they were + + + align:start position:0% +filmmaker tell you what they were +thinking when they created this thing + + align:start position:0% +thinking when they created this thing + + + align:start position:0% +thinking when they created this thing +right how other audiences responded to + + align:start position:0% +right how other audiences responded to + + + align:start position:0% +right how other audiences responded to +it and so on and then of course just the + + align:start position:0% +it and so on and then of course just the + + + align:start position:0% +it and so on and then of course just the +experience of leaving MIT I think it's + + align:start position:0% +experience of leaving MIT I think it's + + + align:start position:0% +experience of leaving MIT I think it's +really useful like I remember when I was + + align:start position:0% +really useful like I remember when I was + + + align:start position:0% +really useful like I remember when I was +an undergrad you know Harvard seems far + + align:start position:0% +an undergrad you know Harvard seems far + + + align:start position:0% +an undergrad you know Harvard seems far +as I think part of our duty is as + + align:start position:0% +as I think part of our duty is as + + + align:start position:0% +as I think part of our duty is as +educators also is to you know help + + align:start position:0% +educators also is to you know help + + + align:start position:0% +educators also is to you know help +broaden our students horizons both in + + align:start position:0% +broaden our students horizons both in + + + align:start position:0% +broaden our students horizons both in +the classroom but also by encouraging + + align:start position:0% +the classroom but also by encouraging + + + align:start position:0% +the classroom but also by encouraging +them to just go explore beyond campus + + align:start position:0% +them to just go explore beyond campus + + + align:start position:0% +them to just go explore beyond campus +professor ed o also has a unique way of + + align:start position:0% +professor ed o also has a unique way of + + + align:start position:0% +professor ed o also has a unique way of +broadening students horizons within the + + align:start position:0% +broadening students horizons within the + + + align:start position:0% +broadening students horizons within the +classroom as well by reshaping their + + align:start position:0% +classroom as well by reshaping their + + + align:start position:0% +classroom as well by reshaping their +relationship with academic texts all + + align:start position:0% +relationship with academic texts all + + + align:start position:0% +relationship with academic texts all +part of an intentional process to + + align:start position:0% +part of an intentional process to + + + align:start position:0% +part of an intentional process to +eradicate the barrier placed between + + align:start position:0% +eradicate the barrier placed between + + + align:start position:0% +eradicate the barrier placed between +academic work and life so when I you + + align:start position:0% +academic work and life so when I you + + + align:start position:0% +academic work and life so when I you +know I've been I was a student for a + + align:start position:0% +know I've been I was a student for a + + + align:start position:0% +know I've been I was a student for a +very long time and I was very frequently + + align:start position:0% +very long time and I was very frequently + + + align:start position:0% +very long time and I was very frequently +frustrated by the fact that academic + + align:start position:0% +frustrated by the fact that academic + + + align:start position:0% +frustrated by the fact that academic +texts often feel like they're written to + + align:start position:0% +texts often feel like they're written to + + + align:start position:0% +texts often feel like they're written to +not be understood and this made me + + align:start position:0% +not be understood and this made me + + + align:start position:0% +not be understood and this made me +really angry because you know when I was + + align:start position:0% +really angry because you know when I was + + + align:start position:0% +really angry because you know when I was +in grad school for my PhD I thought okay + + align:start position:0% +in grad school for my PhD I thought okay + + + align:start position:0% +in grad school for my PhD I thought okay +I've been in school for many years how + + align:start position:0% +I've been in school for many years how + + + align:start position:0% +I've been in school for many years how +is it that this still makes no sense + + align:start position:0% +is it that this still makes no sense + + + align:start position:0% +is it that this still makes no sense +right it makes no sense to me like how + + align:start position:0% +right it makes no sense to me like how + + + align:start position:0% +right it makes no sense to me like how +you know what what are we doing here + + align:start position:0% +you know what what are we doing here + + + align:start position:0% +you know what what are we doing here +right what is the point of the academic + + align:start position:0% +right what is the point of the academic + + + align:start position:0% +right what is the point of the academic +enterprise if we produce work that can + + align:start position:0% +enterprise if we produce work that can + + + align:start position:0% +enterprise if we produce work that can +be understood + + align:start position:0% +be understood + + + align:start position:0% +be understood +so this has been a gripe of mine for a + + align:start position:0% +so this has been a gripe of mine for a + + + align:start position:0% +so this has been a gripe of mine for a +very long time and and and it was all + + align:start position:0% +very long time and and and it was all + + + align:start position:0% +very long time and and and it was all +the more frustrating when there was no + + align:start position:0% +the more frustrating when there was no + + + align:start position:0% +the more frustrating when there was no +space to express that right because I + + align:start position:0% +space to express that right because I + + + align:start position:0% +space to express that right because I +think the danger when you're a student + + align:start position:0% +think the danger when you're a student + + + align:start position:0% +think the danger when you're a student +often time especially you know at elite + + align:start position:0% +often time especially you know at elite + + + align:start position:0% +often time especially you know at elite +institutions is that you internalize + + align:start position:0% +institutions is that you internalize + + + align:start position:0% +institutions is that you internalize +these like when you don't understand you + + align:start position:0% +these like when you don't understand you + + + align:start position:0% +these like when you don't understand you +think there's something wrong with you + + align:start position:0% +think there's something wrong with you + + + align:start position:0% +think there's something wrong with you +essentially you're not good enough + + align:start position:0% +essentially you're not good enough + + + align:start position:0% +essentially you're not good enough +you're not smart enough when it's a + + align:start position:0% +you're not smart enough when it's a + + + align:start position:0% +you're not smart enough when it's a +structural issue and it's actually on + + align:start position:0% +structural issue and it's actually on + + + align:start position:0% +structural issue and it's actually on +the readers on the writers to write + + align:start position:0% +the readers on the writers to write + + + align:start position:0% +the readers on the writers to write +better or write better work write more + + align:start position:0% +better or write better work write more + + + align:start position:0% +better or write better work write more +clearly so then that requires I think an + + align:start position:0% +clearly so then that requires I think an + + + align:start position:0% +clearly so then that requires I think an +infrastructure to support students in + + align:start position:0% +infrastructure to support students in + + + align:start position:0% +infrastructure to support students in +processing this often opaque work and to + + align:start position:0% +processing this often opaque work and to + + + align:start position:0% +processing this often opaque work and to +me that's how I was thinking about the + + align:start position:0% +me that's how I was thinking about the + + + align:start position:0% +me that's how I was thinking about the +reading responses so as a way to just + + align:start position:0% +reading responses so as a way to just + + + align:start position:0% +reading responses so as a way to just +when you're forced to sit down and write + + align:start position:0% +when you're forced to sit down and write + + + align:start position:0% +when you're forced to sit down and write +something about what you wrote even if + + align:start position:0% +something about what you wrote even if + + + align:start position:0% +something about what you wrote even if +it's just like I don't understand and + + align:start position:0% +it's just like I don't understand and + + + align:start position:0% +it's just like I don't understand and +these are all the questions that are + + align:start position:0% +these are all the questions that are + + + align:start position:0% +these are all the questions that are +coming up for me it already pushes you + + align:start position:0% +coming up for me it already pushes you + + + align:start position:0% +coming up for me it already pushes you +along like kind of your understanding + + align:start position:0% +along like kind of your understanding + + + align:start position:0% +along like kind of your understanding +for yourself and then also gives me as + + align:start position:0% +for yourself and then also gives me as + + + align:start position:0% +for yourself and then also gives me as +the instructor a way to know where + + align:start position:0% +the instructor a way to know where + + + align:start position:0% +the instructor a way to know where +you're at and you know what I need to + + align:start position:0% +you're at and you know what I need to + + + align:start position:0% +you're at and you know what I need to +bring to the just kind of in the + + align:start position:0% +bring to the just kind of in the + + + align:start position:0% +bring to the just kind of in the +classroom discussion so what I asked her + + align:start position:0% +classroom discussion so what I asked her + + + align:start position:0% +classroom discussion so what I asked her +to do was to try to summarize the key + + align:start position:0% +to do was to try to summarize the key + + + align:start position:0% +to do was to try to summarize the key +points of the argument and then they + + align:start position:0% +points of the argument and then they + + + align:start position:0% +points of the argument and then they +were free to take it in any number of + + align:start position:0% +were free to take it in any number of + + + align:start position:0% +were free to take it in any number of +directions it could either relate it to + + align:start position:0% +directions it could either relate it to + + + align:start position:0% +directions it could either relate it to +other work that we've read in class they + + align:start position:0% +other work that we've read in class they + + + align:start position:0% +other work that we've read in class they +could relate it to stuff in the news + + align:start position:0% +could relate it to stuff in the news + + + align:start position:0% +could relate it to stuff in the news +that they're seeing around it they could + + align:start position:0% +that they're seeing around it they could + + + align:start position:0% +that they're seeing around it they could +relate it seeing around them and kind of + + align:start position:0% +relate it seeing around them and kind of + + + align:start position:0% +relate it seeing around them and kind of +use what was coming up in the readings + + align:start position:0% +use what was coming up in the readings + + + align:start position:0% +use what was coming up in the readings +as a way to make sense of these things + + align:start position:0% +as a way to make sense of these things + + + align:start position:0% +as a way to make sense of these things +they were observing around them or kind + + align:start position:0% +they were observing around them or kind + + + align:start position:0% +they were observing around them or kind +of related to their personal experience + + align:start position:0% +of related to their personal experience + + + align:start position:0% +of related to their personal experience +something going on in their own lives or + + align:start position:0% +something going on in their own lives or + + + align:start position:0% +something going on in their own lives or +you know and the what I wanted to do + + align:start position:0% +you know and the what I wanted to do + + + align:start position:0% +you know and the what I wanted to do +there was again to to show that what we + + align:start position:0% +there was again to to show that what we + + + align:start position:0% +there was again to to show that what we +do in the classroom is not separate + + align:start position:0% +do in the classroom is not separate + + + align:start position:0% +do in the classroom is not separate +academic work isn't separate from life + + align:start position:0% +academic work isn't separate from life + + + align:start position:0% +academic work isn't separate from life +right like it's not and it's not + + align:start position:0% +right like it's not and it's not + + + align:start position:0% +right like it's not and it's not +something that's only accessible to some + + align:start position:0% +something that's only accessible to some + + + align:start position:0% +something that's only accessible to some +people right we are always theorizing + + align:start position:0% +people right we are always theorizing + + + align:start position:0% +people right we are always theorizing +when we make some making sense of our + + align:start position:0% +when we make some making sense of our + + + align:start position:0% +when we make some making sense of our +experience is about theorizing and so to + + align:start position:0% +experience is about theorizing and so to + + + align:start position:0% +experience is about theorizing and so to +offer possibilities for students to make + + align:start position:0% +offer possibilities for students to make + + + align:start position:0% +offer possibilities for students to make +these links between what they're reading + + align:start position:0% +these links between what they're reading + + + align:start position:0% +these links between what they're reading +for school and what they're experiencing + + align:start position:0% +for school and what they're experiencing + + + align:start position:0% +for school and what they're experiencing +in the world around them if we can do + + align:start position:0% +in the world around them if we can do + + + align:start position:0% +in the world around them if we can do +that I think you know we're in great + + align:start position:0% +that I think you know we're in great + + + align:start position:0% +that I think you know we're in great +shape as educators I really love you + + align:start position:0% +shape as educators I really love you + + + align:start position:0% +shape as educators I really love you +know being able to point to something + + align:start position:0% +know being able to point to something + + + align:start position:0% +know being able to point to something +that they've said in making my argument + + align:start position:0% +that they've said in making my argument + + + align:start position:0% +that they've said in making my argument +right so or in presenting my lesson so + + align:start position:0% +right so or in presenting my lesson so + + + align:start position:0% +right so or in presenting my lesson so +if I can say yeah as you brought up in + + align:start position:0% +if I can say yeah as you brought up in + + + align:start position:0% +if I can say yeah as you brought up in +your paper this thing is going on in the + + align:start position:0% +your paper this thing is going on in the + + + align:start position:0% +your paper this thing is going on in the +reading that's exactly right and we also + + align:start position:0% +reading that's exactly right and we also + + + align:start position:0% +reading that's exactly right and we also +see you know so it to show that + + align:start position:0% +see you know so it to show that + + + align:start position:0% +see you know so it to show that +when I'm taking their work seriously + + align:start position:0% +when I'm taking their work seriously + + + align:start position:0% +when I'm taking their work seriously +right and also that they have something + + align:start position:0% +right and also that they have something + + + align:start position:0% +right and also that they have something +to offer to me I think right what's made + + align:start position:0% +to offer to me I think right what's made + + + align:start position:0% +to offer to me I think right what's made +the biggest difference for me in the + + align:start position:0% +the biggest difference for me in the + + + align:start position:0% +the biggest difference for me in the +classroom as a student has been + + align:start position:0% +classroom as a student has been + + + align:start position:0% +classroom as a student has been +instructors who made me feel like I had + + align:start position:0% +instructors who made me feel like I had + + + align:start position:0% +instructors who made me feel like I had +something to offer and and you know and + + align:start position:0% +something to offer and and you know and + + + align:start position:0% +something to offer and and you know and +the the the lack of that does a lot of + + align:start position:0% +the the the lack of that does a lot of + + + align:start position:0% +the the the lack of that does a lot of +damage you might have having instructors + + align:start position:0% +damage you might have having instructors + + + align:start position:0% +damage you might have having instructors +and make you feel like you have nothing + + align:start position:0% +and make you feel like you have nothing + + + align:start position:0% +and make you feel like you have nothing +to offer it that's actually damaging + + align:start position:0% +to offer it that's actually damaging + + + align:start position:0% +to offer it that's actually damaging +it's not just neutralized damaging so + + align:start position:0% +it's not just neutralized damaging so + + + align:start position:0% +it's not just neutralized damaging so +it's really important for me to sort of + + align:start position:0% +it's really important for me to sort of + + + align:start position:0% +it's really important for me to sort of +valorize students voices and to show + + align:start position:0% +valorize students voices and to show + + + align:start position:0% +valorize students voices and to show +them that they're doing in part of why + + align:start position:0% +them that they're doing in part of why + + + align:start position:0% +them that they're doing in part of why +we wanted to profile professor Eidos + + align:start position:0% +we wanted to profile professor Eidos + + + align:start position:0% +we wanted to profile professor Eidos +teaching of her global Africa class was + + align:start position:0% +teaching of her global Africa class was + + + align:start position:0% +teaching of her global Africa class was +her willingness to try things in the + + align:start position:0% +her willingness to try things in the + + + align:start position:0% +her willingness to try things in the +classroom that were new to her such as + + align:start position:0% +classroom that were new to her such as + + + align:start position:0% +classroom that were new to her such as +inviting students to participate in + + align:start position:0% +inviting students to participate in + + + align:start position:0% +inviting students to participate in +creative production this approach + + align:start position:0% +creative production this approach + + + align:start position:0% +creative production this approach +culminated in a final project assignment + + align:start position:0% +culminated in a final project assignment + + + align:start position:0% +culminated in a final project assignment +that had to say the least + + align:start position:0% +that had to say the least + + + align:start position:0% +that had to say the least +exceeded expectations in the final + + align:start position:0% +exceeded expectations in the final + + + align:start position:0% +exceeded expectations in the final +project assignment students were asked + + align:start position:0% +project assignment students were asked + + + align:start position:0% +project assignment students were asked +to examine how Africa's place in the + + align:start position:0% +to examine how Africa's place in the + + + align:start position:0% +to examine how Africa's place in the +world is negotiated through creative + + align:start position:0% +world is negotiated through creative + + + align:start position:0% +world is negotiated through creative +production what kind of challenges did + + align:start position:0% +production what kind of challenges did + + + align:start position:0% +production what kind of challenges did +students take on in this work my poor + + align:start position:0% +students take on in this work my poor + + + align:start position:0% +students take on in this work my poor +students how many more students because + + align:start position:0% +students how many more students because + + + align:start position:0% +students how many more students because +this is an experiment I thought it'd be + + align:start position:0% +this is an experiment I thought it'd be + + + align:start position:0% +this is an experiment I thought it'd be +really cool I mean it seemed you know it + + align:start position:0% +really cool I mean it seemed you know it + + + align:start position:0% +really cool I mean it seemed you know it +seemed like the right thing in the + + align:start position:0% +seemed like the right thing in the + + + align:start position:0% +seemed like the right thing in the +course we're looking at people who are + + align:start position:0% +course we're looking at people who are + + + align:start position:0% +course we're looking at people who are +making creative work doing creative work + + align:start position:0% +making creative work doing creative work + + + align:start position:0% +making creative work doing creative work +in different arenas it seemed like the + + align:start position:0% +in different arenas it seemed like the + + + align:start position:0% +in different arenas it seemed like the +right way to culminates as students to + + align:start position:0% +right way to culminates as students to + + + align:start position:0% +right way to culminates as students to +do the same himself and yeah I had no + + align:start position:0% +do the same himself and yeah I had no + + + align:start position:0% +do the same himself and yeah I had no +idea how it turned out because I didn't + + align:start position:0% +idea how it turned out because I didn't + + + align:start position:0% +idea how it turned out because I didn't +know what they were bringing to the + + align:start position:0% +know what they were bringing to the + + + align:start position:0% +know what they were bringing to the +table if they you know what particular + + align:start position:0% +table if they you know what particular + + + align:start position:0% +table if they you know what particular +skills they had I creative skills but I + + align:start position:0% +skills they had I creative skills but I + + + align:start position:0% +skills they had I creative skills but I +want to believe this is something I I + + align:start position:0% +want to believe this is something I I + + + align:start position:0% +want to believe this is something I I +try to enact in my own life that we all + + align:start position:0% +try to enact in my own life that we all + + + align:start position:0% +try to enact in my own life that we all +have creative skills and so whatever you + + align:start position:0% +have creative skills and so whatever you + + + align:start position:0% +have creative skills and so whatever you +have we can do something with it and + + align:start position:0% +have we can do something with it and + + + align:start position:0% +have we can do something with it and +they were you know blessing because they + + align:start position:0% +they were you know blessing because they + + + align:start position:0% +they were you know blessing because they +were game for the experiment because I + + align:start position:0% +were game for the experiment because I + + + align:start position:0% +were game for the experiment because I +had done this if I didn't know how it + + align:start position:0% +had done this if I didn't know how it + + + align:start position:0% +had done this if I didn't know how it +was how it was going to go but I I asked + + align:start position:0% +was how it was going to go but I I asked + + + align:start position:0% +was how it was going to go but I I asked +them to pick a topic that they were + + align:start position:0% +them to pick a topic that they were + + + align:start position:0% +them to pick a topic that they were +interested in either something we'd + + align:start position:0% +interested in either something we'd + + + align:start position:0% +interested in either something we'd +already talked about in class that they + + align:start position:0% +already talked about in class that they + + + align:start position:0% +already talked about in class that they +wanted to take farther or another + + align:start position:0% +wanted to take farther or another + + + align:start position:0% +wanted to take farther or another +another topic altogether and the key was + + align:start position:0% +another topic altogether and the key was + + + align:start position:0% +another topic altogether and the key was +to use this object this thing that they + + align:start position:0% +to use this object this thing that they + + + align:start position:0% +to use this object this thing that they +would make as a way to think through + + align:start position:0% +would make as a way to think through + + + align:start position:0% +would make as a way to think through +these questions about Africa + + align:start position:0% +these questions about Africa + + + align:start position:0% +these questions about Africa +based in the world it's quite broad but + + align:start position:0% +based in the world it's quite broad but + + + align:start position:0% +based in the world it's quite broad but +I was so happy with the things they came + + align:start position:0% +I was so happy with the things they came + + + align:start position:0% +I was so happy with the things they came +up with you know I was wonderful it was + + align:start position:0% +up with you know I was wonderful it was + + + align:start position:0% +up with you know I was wonderful it was +so fun we had anything from like it was + + align:start position:0% +so fun we had anything from like it was + + + align:start position:0% +so fun we had anything from like it was +no student who was interested in plants + + align:start position:0% +no student who was interested in plants + + + align:start position:0% +no student who was interested in plants +and she picked this plant one of these + + align:start position:0% +and she picked this plant one of these + + + align:start position:0% +and she picked this plant one of these +eye things like the ficus plant some + + align:start position:0% +eye things like the ficus plant some + + + align:start position:0% +eye things like the ficus plant some +plant that's really sexy right now in + + align:start position:0% +plant that's really sexy right now in + + + align:start position:0% +plant that's really sexy right now in +like the interior decoration decorating + + align:start position:0% +like the interior decoration decorating + + + align:start position:0% +like the interior decoration decorating +world and it's a plant that grows on the + + align:start position:0% +world and it's a plant that grows on the + + + align:start position:0% +world and it's a plant that grows on the +side of the street in West Africa and so + + align:start position:0% +side of the street in West Africa and so + + + align:start position:0% +side of the street in West Africa and so +on and so she did this cool project or + + align:start position:0% +on and so she did this cool project or + + + align:start position:0% +on and so she did this cool project or +she took the plan and looked at the + + align:start position:0% +she took the plan and looked at the + + + align:start position:0% +she took the plan and looked at the +different ways that it is made to mean + + align:start position:0% +different ways that it is made to mean + + + align:start position:0% +different ways that it is made to mean +as a kind of luxury decoration item and + + align:start position:0% +as a kind of luxury decoration item and + + + align:start position:0% +as a kind of luxury decoration item and +verses in central Africa where it's used + + align:start position:0% +verses in central Africa where it's used + + + align:start position:0% +verses in central Africa where it's used +for Africa like some part of the tree is + + align:start position:0% +for Africa like some part of the tree is + + + align:start position:0% +for Africa like some part of the tree is +used for bark cloth and so from there so + + align:start position:0% +used for bark cloth and so from there so + + + align:start position:0% +used for bark cloth and so from there so +you could talk about the circulation of + + align:start position:0% +you could talk about the circulation of + + + align:start position:0% +you could talk about the circulation of +objects in a way that value gets our + + align:start position:0% +objects in a way that value gets our + + + align:start position:0% +objects in a way that value gets our +thinking and so on or other students who + + align:start position:0% +thinking and so on or other students who + + + align:start position:0% +thinking and so on or other students who +wanted to talk about the way that + + align:start position:0% +wanted to talk about the way that + + + align:start position:0% +wanted to talk about the way that +tradition that's kind of yeah related + + align:start position:0% +tradition that's kind of yeah related + + + align:start position:0% +tradition that's kind of yeah related +the way that tradition gets articulated + + align:start position:0% +the way that tradition gets articulated + + + align:start position:0% +the way that tradition gets articulated +and they were interested in looking at + + align:start position:0% +and they were interested in looking at + + + align:start position:0% +and they were interested in looking at +wedding ceremonies in them not in + + align:start position:0% +wedding ceremonies in them not in + + + align:start position:0% +wedding ceremonies in them not in +Nigerian American sort of in the + + align:start position:0% +Nigerian American sort of in the + + + align:start position:0% +Nigerian American sort of in the +Nigerian American context where people + + align:start position:0% +Nigerian American context where people + + + align:start position:0% +Nigerian American context where people +are kind of working across these + + align:start position:0% +are kind of working across these + + + align:start position:0% +are kind of working across these +different cultures these two different + + align:start position:0% +different cultures these two different + + + align:start position:0% +different cultures these two different +cultural realms and to consider you know + + align:start position:0% +cultural realms and to consider you know + + + align:start position:0% +cultural realms and to consider you know +what do you keep of a tradition what do + + align:start position:0% +what do you keep of a tradition what do + + + align:start position:0% +what do you keep of a tradition what do +you update what does it mean to treat + + align:start position:0% +you update what does it mean to treat + + + align:start position:0% +you update what does it mean to treat +women a particular way and men a + + align:start position:0% +women a particular way and men a + + + align:start position:0% +women a particular way and men a +particular way which what should you + + align:start position:0% +particular way which what should you + + + align:start position:0% +particular way which what should you +uphold what should you you know resists + + align:start position:0% +uphold what should you you know resists + + + align:start position:0% +uphold what should you you know resists +given you know when you're a Nigerian + + align:start position:0% +given you know when you're a Nigerian + + + align:start position:0% +given you know when you're a Nigerian +American and you're kind of beholden or + + align:start position:0% +American and you're kind of beholden or + + + align:start position:0% +American and you're kind of beholden or +you belong to these two different + + align:start position:0% +you belong to these two different + + + align:start position:0% +you belong to these two different +cultures and so what they did which I + + align:start position:0% +cultures and so what they did which I + + + align:start position:0% +cultures and so what they did which I +thought was so brilliant was that they + + align:start position:0% +thought was so brilliant was that they + + + align:start position:0% +thought was so brilliant was that they +put together a picture book because we'd + + align:start position:0% +put together a picture book because we'd + + + align:start position:0% +put together a picture book because we'd +also one of the classes had talked about + + align:start position:0% +also one of the classes had talked about + + + align:start position:0% +also one of the classes had talked about +these photo novels as a genre of image + + align:start position:0% +these photo novels as a genre of image + + + align:start position:0% +these photo novels as a genre of image +and story telling image production and + + align:start position:0% +and story telling image production and + + + align:start position:0% +and story telling image production and +storytelling and so they use that format + + align:start position:0% +storytelling and so they use that format + + + align:start position:0% +storytelling and so they use that format +that we talked about it in the class and + + align:start position:0% +that we talked about it in the class and + + + align:start position:0% +that we talked about it in the class and +took the theme that they were interested + + align:start position:0% +took the theme that they were interested + + + align:start position:0% +took the theme that they were interested +in arounds or the politics of tradition + + align:start position:0% +in arounds or the politics of tradition + + + align:start position:0% +in arounds or the politics of tradition +and in ebo weddings and wrote a story + + align:start position:0% +and in ebo weddings and wrote a story + + + align:start position:0% +and in ebo weddings and wrote a story +that featured them grappling with these + + align:start position:0% +that featured them grappling with these + + + align:start position:0% +that featured them grappling with these +questions so it was quite meta because + + align:start position:0% +questions so it was quite meta because + + + align:start position:0% +questions so it was quite meta because +they told you you know they talked about + + align:start position:0% +they told you you know they talked about + + + align:start position:0% +they told you you know they talked about +the the topic they were interested in + + align:start position:0% +the the topic they were interested in + + + align:start position:0% +the the topic they were interested in +but then they also showed you the + + align:start position:0% +but then they also showed you the + + + align:start position:0% +but then they also showed you the +questions that they brought up it wasn't + + align:start position:0% +questions that they brought up it wasn't + + + align:start position:0% +questions that they brought up it wasn't +a resolved + + align:start position:0% +a resolved + + + align:start position:0% +a resolved +thing and it was meant to be circulated + + align:start position:0% +thing and it was meant to be circulated + + + align:start position:0% +thing and it was meant to be circulated +and it was an object that could be used + + align:start position:0% +and it was an object that could be used + + + align:start position:0% +and it was an object that could be used +to spur questions and so on and so it + + align:start position:0% +to spur questions and so on and so it + + + align:start position:0% +to spur questions and so on and so it +was fantastic I loved I so enjoyed them + + align:start position:0% +was fantastic I loved I so enjoyed them + + + align:start position:0% +was fantastic I loved I so enjoyed them +there was something we had a coffee + + align:start position:0% +there was something we had a coffee + + + align:start position:0% +there was something we had a coffee +ceremony in class like in the Philippine + + align:start position:0% +ceremony in class like in the Philippine + + + align:start position:0% +ceremony in class like in the Philippine +coffee ceremony and the sort of + + align:start position:0% +coffee ceremony and the sort of + + + align:start position:0% +coffee ceremony and the sort of +questions that brings up about what does + + align:start position:0% +questions that brings up about what does + + + align:start position:0% +questions that brings up about what does +it take to actually and act what the + + align:start position:0% +it take to actually and act what the + + + align:start position:0% +it take to actually and act what the +ceremony is is supposed to enact when + + align:start position:0% +ceremony is is supposed to enact when + + + align:start position:0% +ceremony is is supposed to enact when +you take it out of Ethiopia and when you + + align:start position:0% +you take it out of Ethiopia and when you + + + align:start position:0% +you take it out of Ethiopia and when you +take it into a dorm room for instance + + align:start position:0% +take it into a dorm room for instance + + + align:start position:0% +take it into a dorm room for instance +and you only have certain implements to + + align:start position:0% +and you only have certain implements to + + + align:start position:0% +and you only have certain implements to +use to what extent you know does it + + align:start position:0% +use to what extent you know does it + + + align:start position:0% +use to what extent you know does it +retain its value its significance but it + + align:start position:0% +retain its value its significance but it + + + align:start position:0% +retain its value its significance but it +was wonderful to see them start happy + + align:start position:0% +was wonderful to see them start happy + + + align:start position:0% +was wonderful to see them start happy +like oh my god I have no idea what I'm + + align:start position:0% +like oh my god I have no idea what I'm + + + align:start position:0% +like oh my god I have no idea what I'm +gonna do and then just figuring it out + + align:start position:0% +gonna do and then just figuring it out + + + align:start position:0% +gonna do and then just figuring it out +and coming up with something amazing we + + align:start position:0% +and coming up with something amazing we + + + align:start position:0% +and coming up with something amazing we +actually have the example of the wedding + + align:start position:0% +actually have the example of the wedding + + + align:start position:0% +actually have the example of the wedding +conflict book on the OCW website we've + + align:start position:0% +conflict book on the OCW website we've + + + align:start position:0% +conflict book on the OCW website we've +linked to it in the show notes so be + + align:start position:0% +linked to it in the show notes so be + + + align:start position:0% +linked to it in the show notes so be +sure to take a look to close our + + align:start position:0% +sure to take a look to close our + + + align:start position:0% +sure to take a look to close our +conversation I wanted to see what advice + + align:start position:0% +conversation I wanted to see what advice + + + align:start position:0% +conversation I wanted to see what advice +Alma has for other educators looking to + + align:start position:0% +Alma has for other educators looking to + + + align:start position:0% +Alma has for other educators looking to +employ some of her techniques in their + + align:start position:0% +employ some of her techniques in their + + + align:start position:0% +employ some of her techniques in their +classes what are her strategies for + + align:start position:0% +classes what are her strategies for + + + align:start position:0% +classes what are her strategies for +keeping her class engaging thoughtful + + align:start position:0% +keeping her class engaging thoughtful + + + align:start position:0% +keeping her class engaging thoughtful +and illuminating so one key thing is + + align:start position:0% +and illuminating so one key thing is + + + align:start position:0% +and illuminating so one key thing is +being clear on what the core issue is in + + align:start position:0% +being clear on what the core issue is in + + + align:start position:0% +being clear on what the core issue is in +the class right so what's the core + + align:start position:0% +the class right so what's the core + + + align:start position:0% +the class right so what's the core +what's the question that animates this + + align:start position:0% +what's the question that animates this + + + align:start position:0% +what's the question that animates this +class and for me it's useful to kind of + + align:start position:0% +class and for me it's useful to kind of + + + align:start position:0% +class and for me it's useful to kind of +know that and have that because that + + align:start position:0% +know that and have that because that + + + align:start position:0% +know that and have that because that +helps me sort of adjust that's needed so + + align:start position:0% +helps me sort of adjust that's needed so + + + align:start position:0% +helps me sort of adjust that's needed so +I so to figure out okay what do I need + + align:start position:0% +I so to figure out okay what do I need + + + align:start position:0% +I so to figure out okay what do I need +what do i what do I want these students + + align:start position:0% +what do i what do I want these students + + + align:start position:0% +what do i what do I want these students +to come away with no matter what so that + + align:start position:0% +to come away with no matter what so that + + + align:start position:0% +to come away with no matter what so that +if what I have planned is not taking us + + align:start position:0% +if what I have planned is not taking us + + + align:start position:0% +if what I have planned is not taking us +there then I can try something else that + + align:start position:0% +there then I can try something else that + + + align:start position:0% +there then I can try something else that +might get us there so being clear on + + align:start position:0% +might get us there so being clear on + + + align:start position:0% +might get us there so being clear on +this question so for this class you know + + align:start position:0% +this question so for this class you know + + + align:start position:0% +this question so for this class you know +global Africa creative culture is the + + align:start position:0% +global Africa creative culture is the + + + align:start position:0% +global Africa creative culture is the +idea was to examine Africa's place in + + align:start position:0% +idea was to examine Africa's place in + + + align:start position:0% +idea was to examine Africa's place in +the world as as being made visible + + align:start position:0% +the world as as being made visible + + + align:start position:0% +the world as as being made visible +through different kinds of creative + + align:start position:0% +through different kinds of creative + + + align:start position:0% +through different kinds of creative +practice so I structured it according to + + align:start position:0% +practice so I structured it according to + + + align:start position:0% +practice so I structured it according to +things that I was familiar with from my + + align:start position:0% +things that I was familiar with from my + + + align:start position:0% +things that I was familiar with from my +work or interested in and that I wanted + + align:start position:0% +work or interested in and that I wanted + + + align:start position:0% +work or interested in and that I wanted +to explore more so that's one way to to + + align:start position:0% +to explore more so that's one way to to + + + align:start position:0% +to explore more so that's one way to to +go about deciding what the different + + align:start position:0% +go about deciding what the different + + + align:start position:0% +go about deciding what the different +units are going to be right so I'm I'm + + align:start position:0% +units are going to be right so I'm I'm + + + align:start position:0% +units are going to be right so I'm I'm +interested in dress for instance and so + + align:start position:0% +interested in dress for instance and so + + + align:start position:0% +interested in dress for instance and so +performance as dress was something that + + align:start position:0% +performance as dress was something that + + + align:start position:0% +performance as dress was something that +was really into doing so the pieces of + + align:start position:0% +was really into doing so the pieces of + + + align:start position:0% +was really into doing so the pieces of +the class can be completely different + + align:start position:0% +the class can be completely different + + + align:start position:0% +the class can be completely different +they can focus on different kind of + + align:start position:0% +they can focus on different kind of + + + align:start position:0% +they can focus on different kind of +creative practices you can spend more + + align:start position:0% +creative practices you can spend more + + + align:start position:0% +creative practices you can spend more +than one week on a particular creative + + align:start position:0% +than one week on a particular creative + + + align:start position:0% +than one week on a particular creative +practice right so the + + align:start position:0% +practice right so the + + + align:start position:0% +practice right so the +building blocks can be different and as + + align:start position:0% +building blocks can be different and as + + + align:start position:0% +building blocks can be different and as +long as a core question is as clear then + + align:start position:0% +long as a core question is as clear then + + + align:start position:0% +long as a core question is as clear then +you can sort of tailor that to your + + align:start position:0% +you can sort of tailor that to your + + + align:start position:0% +you can sort of tailor that to your +interest but then also to what's + + align:start position:0% +interest but then also to what's + + + align:start position:0% +interest but then also to what's +available what's cool about the notion + + align:start position:0% +available what's cool about the notion + + + align:start position:0% +available what's cool about the notion +of kind of creative practice is that + + align:start position:0% +of kind of creative practice is that + + + align:start position:0% +of kind of creative practice is that +it's very broad like it can be as broad + + align:start position:0% +it's very broad like it can be as broad + + + align:start position:0% +it's very broad like it can be as broad +as you want it to be so it can be + + align:start position:0% +as you want it to be so it can be + + + align:start position:0% +as you want it to be so it can be +restructured you know any number of ways + + align:start position:0% +restructured you know any number of ways + + + align:start position:0% +restructured you know any number of ways +depending on the resources that are + + align:start position:0% +depending on the resources that are + + + align:start position:0% +depending on the resources that are +available and the questions that you are + + align:start position:0% +available and the questions that you are + + + align:start position:0% +available and the questions that you are +used or your students are interested in + + align:start position:0% +used or your students are interested in + + + align:start position:0% +used or your students are interested in +and tied to that is the fact that as + + align:start position:0% +and tied to that is the fact that as + + + align:start position:0% +and tied to that is the fact that as +someone told me a colleague told me once + + align:start position:0% +someone told me a colleague told me once + + + align:start position:0% +someone told me a colleague told me once +that we're talking about you know + + align:start position:0% +that we're talking about you know + + + align:start position:0% +that we're talking about you know +first-year faculty and we're both + + align:start position:0% +first-year faculty and we're both + + + align:start position:0% +first-year faculty and we're both +talking about how exhausted we were all + + align:start position:0% +talking about how exhausted we were all + + + align:start position:0% +talking about how exhausted we were all +the time and she said someone told her + + align:start position:0% +the time and she said someone told her + + + align:start position:0% +the time and she said someone told her +you know that teaching is essentially + + align:start position:0% +you know that teaching is essentially + + + align:start position:0% +you know that teaching is essentially +like stand-up or improv right like you + + align:start position:0% +like stand-up or improv right like you + + + align:start position:0% +like stand-up or improv right like you +get up there and you're on and it's + + align:start position:0% +get up there and you're on and it's + + + align:start position:0% +get up there and you're on and it's +improv because you are responding to + + align:start position:0% +improv because you are responding to + + + align:start position:0% +improv because you are responding to +what your students are giving you and + + align:start position:0% +what your students are giving you and + + + align:start position:0% +what your students are giving you and +you have no idea what it's going to be + + align:start position:0% +you have no idea what it's going to be + + + align:start position:0% +you have no idea what it's going to be +no matter how well planned it is you + + align:start position:0% +no matter how well planned it is you + + + align:start position:0% +no matter how well planned it is you +have no idea where it might end up and + + align:start position:0% +have no idea where it might end up and + + + align:start position:0% +have no idea where it might end up and +you have to respond so it's not just + + align:start position:0% +you have to respond so it's not just + + + align:start position:0% +you have to respond so it's not just +that you they're taking it but you have + + align:start position:0% +that you they're taking it but you have + + + align:start position:0% +that you they're taking it but you have +based on what you're getting you have to + + align:start position:0% +based on what you're getting you have to + + + align:start position:0% +based on what you're getting you have to +figure out where to take it in order to + + align:start position:0% +figure out where to take it in order to + + + align:start position:0% +figure out where to take it in order to +come back to the conclusions that you + + align:start position:0% +come back to the conclusions that you + + + align:start position:0% +come back to the conclusions that you +think you need to and that and also be + + align:start position:0% +think you need to and that and also be + + + align:start position:0% +think you need to and that and also be +open to that not happening and when + + align:start position:0% +open to that not happening and when + + + align:start position:0% +open to that not happening and when +you're new you just you don't know and + + align:start position:0% +you're new you just you don't know and + + + align:start position:0% +you're new you just you don't know and +when you've been a student and you've + + align:start position:0% +when you've been a student and you've + + + align:start position:0% +when you've been a student and you've +had these professors up front who seem + + align:start position:0% +had these professors up front who seem + + + align:start position:0% +had these professors up front who seem +to know exactly what they're doing what + + align:start position:0% +to know exactly what they're doing what + + + align:start position:0% +to know exactly what they're doing what +they're talking about + + align:start position:0% +they're talking about + + + align:start position:0% +they're talking about +you don't fully appreciate the fact that + + align:start position:0% +you don't fully appreciate the fact that + + + align:start position:0% +you don't fully appreciate the fact that +it's a lot of intuitive and + + align:start position:0% +it's a lot of intuitive and + + + align:start position:0% +it's a lot of intuitive and +improvisational work and so you can be + + align:start position:0% +improvisational work and so you can be + + + align:start position:0% +improvisational work and so you can be +surprised at how taxing it is you know + + align:start position:0% +surprised at how taxing it is you know + + + align:start position:0% +surprised at how taxing it is you know +so at the end of a three hour class I + + align:start position:0% +so at the end of a three hour class I + + + align:start position:0% +so at the end of a three hour class I +mean that was wasted oh you know you + + align:start position:0% +mean that was wasted oh you know you + + + align:start position:0% +mean that was wasted oh you know you +just you just so tired because it + + align:start position:0% +just you just so tired because it + + + align:start position:0% +just you just so tired because it +requires so much energy so that's + + align:start position:0% +requires so much energy so that's + + + align:start position:0% +requires so much energy so that's +something to just kind of be aware of + + align:start position:0% +something to just kind of be aware of + + + align:start position:0% +something to just kind of be aware of +which also then can inform you like + + align:start position:0% +which also then can inform you like + + + align:start position:0% +which also then can inform you like +inform your preparation so to know what + + align:start position:0% +inform your preparation so to know what + + + align:start position:0% +inform your preparation so to know what +do you need to do in order to have as + + align:start position:0% +do you need to do in order to have as + + + align:start position:0% +do you need to do in order to have as +much no to stock up to fill up your tank + + align:start position:0% +much no to stock up to fill up your tank + + + align:start position:0% +much no to stock up to fill up your tank +so that you can then do this through our + + align:start position:0% +so that you can then do this through our + + + align:start position:0% +so that you can then do this through our +improv performance and you know + + align:start position:0% +improv performance and you know + + + align:start position:0% +improv performance and you know +generally the less tightly designed it + + align:start position:0% +generally the less tightly designed it + + + align:start position:0% +generally the less tightly designed it +is the better things work out this is + + align:start position:0% +is the better things work out this is + + + align:start position:0% +is the better things work out this is +what I found and what I've heard other + + align:start position:0% +what I found and what I've heard other + + + align:start position:0% +what I found and what I've heard other +colleagues say that you know the days + + align:start position:0% +colleagues say that you know the days + + + align:start position:0% +colleagues say that you know the days +went they were running from meeting to + + align:start position:0% +went they were running from meeting to + + + align:start position:0% +went they were running from meeting to +meeting and they didn't quite have + + align:start position:0% +meeting and they didn't quite have + + + align:start position:0% +meeting and they didn't quite have +enough time to finish their course prep + + align:start position:0% +enough time to finish their course prep + + + align:start position:0% +enough time to finish their course prep +or actually the days where the class + + align:start position:0% +or actually the days where the class + + + align:start position:0% +or actually the days where the class +went really well because + + align:start position:0% +went really well because + + + align:start position:0% +went really well because +they had no choice but to be there and + + align:start position:0% +they had no choice but to be there and + + + align:start position:0% +they had no choice but to be there and +listen to the students and meet them + + align:start position:0% +listen to the students and meet them + + + align:start position:0% +listen to the students and meet them +where they were and follow that organic + + align:start position:0% +where they were and follow that organic + + + align:start position:0% +where they were and follow that organic +progression of the conversation instead + + align:start position:0% +progression of the conversation instead + + + align:start position:0% +progression of the conversation instead +of sticking to their script yeah so I + + align:start position:0% +of sticking to their script yeah so I + + + align:start position:0% +of sticking to their script yeah so I +think you know the key pieces of advice + + align:start position:0% +think you know the key pieces of advice + + + align:start position:0% +think you know the key pieces of advice +I would give are kind of one flexibility + + align:start position:0% +I would give are kind of one flexibility + + + align:start position:0% +I would give are kind of one flexibility +both in sort of the approach to teaching + + align:start position:0% +both in sort of the approach to teaching + + + align:start position:0% +both in sort of the approach to teaching +and recognizing the flexibility that you + + align:start position:0% +and recognizing the flexibility that you + + + align:start position:0% +and recognizing the flexibility that you +have in designing the course and + + align:start position:0% +have in designing the course and + + + align:start position:0% +have in designing the course and +choosing what you put in it and then and + + align:start position:0% +choosing what you put in it and then and + + + align:start position:0% +choosing what you put in it and then and +and tie to this flexibility this + + align:start position:0% +and tie to this flexibility this + + + align:start position:0% +and tie to this flexibility this +experimental approach to building it and + + align:start position:0% +experimental approach to building it and + + + align:start position:0% +experimental approach to building it and +to adjusting it as it goes and then as a + + align:start position:0% +to adjusting it as it goes and then as a + + + align:start position:0% +to adjusting it as it goes and then as a +broader kind of like teaching philosophy + + align:start position:0% +broader kind of like teaching philosophy + + + align:start position:0% +broader kind of like teaching philosophy +thing what I said about using the time + + align:start position:0% +thing what I said about using the time + + + align:start position:0% +thing what I said about using the time +in the classroom as a time to build our + + align:start position:0% +in the classroom as a time to build our + + + align:start position:0% +in the classroom as a time to build our +students confidence right to instill in + + align:start position:0% +students confidence right to instill in + + + align:start position:0% +students confidence right to instill in +our students a sense that they know like + + align:start position:0% +our students a sense that they know like + + + align:start position:0% +our students a sense that they know like +they they are capable of doing this work + + align:start position:0% +they they are capable of doing this work + + + align:start position:0% +they they are capable of doing this work +to validate to affirm and to use that as + + align:start position:0% +to validate to affirm and to use that as + + + align:start position:0% +to validate to affirm and to use that as +a starting point for what it is that we + + align:start position:0% +a starting point for what it is that we + + + align:start position:0% +a starting point for what it is that we +want to impart onto them you know but + + align:start position:0% +want to impart onto them you know but + + + align:start position:0% +want to impart onto them you know but +really to start from to kind of undo + + align:start position:0% +really to start from to kind of undo + + + align:start position:0% +really to start from to kind of undo +some of the damage that academic work + + align:start position:0% +some of the damage that academic work + + + align:start position:0% +some of the damage that academic work +has done for so many people which is + + align:start position:0% +has done for so many people which is + + + align:start position:0% +has done for so many people which is +that its alienating and so - to try to + + align:start position:0% +that its alienating and so - to try to + + + align:start position:0% +that its alienating and so - to try to +see how to make it less alienating - to + + align:start position:0% +see how to make it less alienating - to + + + align:start position:0% +see how to make it less alienating - to +say you know we can do this and we we + + align:start position:0% +say you know we can do this and we we + + + align:start position:0% +say you know we can do this and we we +know how to do this and we're learning + + align:start position:0% +know how to do this and we're learning + + + align:start position:0% +know how to do this and we're learning +and it's okay to not know because we're + + align:start position:0% +and it's okay to not know because we're + + + align:start position:0% +and it's okay to not know because we're +in school to learn not supposed to know + + align:start position:0% +in school to learn not supposed to know + + + align:start position:0% +in school to learn not supposed to know +everything that we come here to make + + align:start position:0% +everything that we come here to make + + + align:start position:0% +everything that we come here to make +that as part of the mission beyond both + + align:start position:0% +that as part of the mission beyond both + + + align:start position:0% +that as part of the mission beyond both +beyond the content of the class itself + + align:start position:0% +beyond the content of the class itself + + + align:start position:0% +beyond the content of the class itself +to just say it's okay to not know and to + + align:start position:0% +to just say it's okay to not know and to + + + align:start position:0% +to just say it's okay to not know and to +not know this particular material but we + + align:start position:0% +not know this particular material but we + + + align:start position:0% +not know this particular material but we +know how to learn and that's what we're + + align:start position:0% +know how to learn and that's what we're + + + align:start position:0% +know how to learn and that's what we're +here for + + align:start position:0% + + + + align:start position:0% + +amah ido is an assistant professor of + + align:start position:0% +amah ido is an assistant professor of + + + align:start position:0% +amah ido is an assistant professor of +African Studies at MIT and now you can + + align:start position:0% +African Studies at MIT and now you can + + + align:start position:0% +African Studies at MIT and now you can +follow her work wherever you are in the + + align:start position:0% +follow her work wherever you are in the + + + align:start position:0% +follow her work wherever you are in the +world in the show notes we've posted a + + align:start position:0% +world in the show notes we've posted a + + + align:start position:0% +world in the show notes we've posted a +link to our faculty page which includes + + align:start position:0% +link to our faculty page which includes + + + align:start position:0% +link to our faculty page which includes +more information about her research + + align:start position:0% +more information about her research + + + align:start position:0% +more information about her research +background and scholarly works as a + + align:start position:0% +background and scholarly works as a + + + align:start position:0% +background and scholarly works as a +bonus we're also giving you a link to + + align:start position:0% +bonus we're also giving you a link to + + + align:start position:0% +bonus we're also giving you a link to +the Spotify playlist that one of our + + align:start position:0% +the Spotify playlist that one of our + + + align:start position:0% +the Spotify playlist that one of our +students created for the class it is + + align:start position:0% +students created for the class it is + + + align:start position:0% +students created for the class it is +fantastic + + align:start position:0% +fantastic + + + align:start position:0% +fantastic +go take a listen also in our show notes + + align:start position:0% +go take a listen also in our show notes + + + align:start position:0% +go take a listen also in our show notes +you'll find a link to Emma's Go Lobel + + align:start position:0% +you'll find a link to Emma's Go Lobel + + + align:start position:0% +you'll find a link to Emma's Go Lobel +Africa course on MIT OpenCourseWare for + + align:start position:0% +Africa course on MIT OpenCourseWare for + + + align:start position:0% +Africa course on MIT OpenCourseWare for +those of you who might be new to the OCW + + align:start position:0% +those of you who might be new to the OCW + + + align:start position:0% +those of you who might be new to the OCW +website you'll find virtually all of MIT + + align:start position:0% +website you'll find virtually all of MIT + + + align:start position:0% +website you'll find virtually all of MIT +s course content for you to explore if + + align:start position:0% +s course content for you to explore if + + + align:start position:0% +s course content for you to explore if +you're an educator build curricula of + + align:start position:0% +you're an educator build curricula of + + + align:start position:0% +you're an educator build curricula of +any kind or just plain curious please + + align:start position:0% +any kind or just plain curious please + + + align:start position:0% +any kind or just plain curious please +take a look we are dedicated to making + + align:start position:0% +take a look we are dedicated to making + + + align:start position:0% +take a look we are dedicated to making +access to all of mi t--'s course content + + align:start position:0% +access to all of mi t--'s course content + + + align:start position:0% +access to all of mi t--'s course content +free and open for the world visit us at + + align:start position:0% +free and open for the world visit us at + + + align:start position:0% +free and open for the world visit us at +ocw.mit.edu in this podcast we'll be + + align:start position:0% +ocw.mit.edu in this podcast we'll be + + + align:start position:0% +ocw.mit.edu in this podcast we'll be +sharing our conversations with some of + + align:start position:0% +sharing our conversations with some of + + + align:start position:0% +sharing our conversations with some of +the amazing MIT educators who've helped + + align:start position:0% +the amazing MIT educators who've helped + + + align:start position:0% +the amazing MIT educators who've helped +populate OCW and whose work has been + + align:start position:0% +populate OCW and whose work has been + + + align:start position:0% +populate OCW and whose work has been +shared thousands of times from our site + + align:start position:0% +shared thousands of times from our site + + + align:start position:0% +shared thousands of times from our site +thanks for listening and please stay + + align:start position:0% +thanks for listening and please stay + + + align:start position:0% +thanks for listening and please stay +tuned + + align:start position:0% +tuned + + + align:start position:0% +tuned +in the meantime share this episode with + + align:start position:0% +in the meantime share this episode with + + + align:start position:0% +in the meantime share this episode with +a friend or leave a review on iTunes + + align:start position:0% +a friend or leave a review on iTunes + + + align:start position:0% +a friend or leave a review on iTunes +[Music] \ No newline at end of file diff --git a/pEOSGrQkn44.txt b/pEOSGrQkn44.txt new file mode 100644 index 0000000000000000000000000000000000000000..594e78ef21a244cf43d15c6985d7046a8bb5403f --- /dev/null +++ b/pEOSGrQkn44.txt @@ -0,0 +1,1593 @@ +PROFESSOR: Any questions before +I obliterate all this + +lovely geometry? + +No. + +OK. + +We handled them during +intermission I guess. + +Let me do a couple more plane +groups just very quickly to + +show you how they come out +without going through all of + +the steps, because I think we've +seen now what one has to + +do to derive these. + +There are two that are left. + +One is a threefold axis, and +if that's all the symmetry + +we've put into the lattice, +we're combining a threefold + +rotation axis with a primitive +lattice, and we know that this + +has to be hexagonal net. + +Because from our depth of +experience, we know that is + +the shape of a lattice that is +demanded by a threefold axis. + +It has two translations, T1, +that are identical in length. + +And this angle between them +is exactly 120 degrees. + +That's what we saw a threefold +access require. + +So now what we are doing is +putting in a threefold axis at + +one lattice point, and this +means we are adding the + +operations A 2 pi over 3. + +A minus 2 pi over 3. + +I'll choose to define a 120 +degree rotation that way, and + +the operation A 2 pi, which is +the identity operations. + +So I'm adding three +operations. + +Putting the threefold axis in +at all these locations. + +They will all be translationally +equivalent. + +The pattern of this particular +plane group is going to be the + +pattern of a threefold axis. + +And so there will be one motif +here, 120 degrees away. + +There will be a-- + +sorry to wipe out those +operations-- + +120 degrees. + +There'll be another object +located here. + +And 120 degrees again, +there will be another + +object located here. + +So these guys will fall +at the corner of + +an equilateral triangle. + +And the same will be at the +other corners of the net, and + +that, as I've said before, +is the pattern + +of that plane group. + +And that's a plane group +that we would call P3. + +Primitive lattice that has to +be hexagonal, and what we've + +added to it is a +threefold axis. + +OK, let me down here just +indicate the combinations that + +we would do. + +And I could do it up on top, +but I can work with this + +translation as well, which is +easier to reach at this late + +hour in the afternoon. + +Let me combine A 2 pi over 3 +with this translation here. + +And that says we have to get +an operation B 2 pi over 3. + +That is located at the original +translation T times + +the cotangent of 1/2 +of 2 pi over 3. + +And that's at 1/2 of the +cotangent of 60 degrees. + +And this turns out not to be any +nice neat number like 0 or + +1/2, but if you evaluate what +the distance up along the + +perpendicular bisector is by +this amount, where you come + +out is right in the center +of this triangle. + +Trust me. + +A little bit of trigonometry +will let you + +convince yourself of that. + +So if I rotate 120 degrees. + +Bring this one to this one, +and then translate over to + +here, the way the first one and +the second one are related + +is by a 120 degree rotation +about the + +center of this triangle. + +If I combine the operation A +minus 2 pi over 3, with this + +translation, I go down a +distance x of minus this + +amount and that puts me in the +middle of the triangle that is + +directly below. + +And I can move that back up. + +And now I have all the +operations of a threefold axis + +about this location. + +I can do the same thing with the +threefold axis at another + +lattice point. + +Another thing I could +do is to just + +rotate this by 120 degrees. + +And by either route, you +find there must be a + +threefold axis here. + +Notice that these threefold +axes will once again, as + +advertised, simply take things +that are at the different + +corners of the cell. + +For example, this threefold axis +will tell you how this + +motif is related to this one +is related to this one. + +And so it goes through the other +threefold axes as well. + +This threefold axis will tell +you this one is related. + +No, I don't want +to draw it in. + +So this is P3, a pair of +threefold axes in the centers + +of the triangle, and another one +at the corner of the cell. + +And now I am going to do the +remaining combination of a + +rotation axis with a lattice, so +quickly, and it's going to + +take your breath away. + +And that is seemingly the +most difficult and + +complex one of all. + +This would be P6. + +Sixfold axis plus a +primitive lattice. + +And we know it also has +to be hexagonal. + +And that will be called P6. + +What we're adding to the lattice +is a sixfold axis. + +And now what I'm going to do +as a shortcut is to say a + +sixfold axis also contains +all the operations + +of a threefold axis. + +So I can take P3 and drop it +right on top of P6, and that's + +going to give me threefold +axes here. + +Sixfold axis not only contains +2 pi over 6 and 2 pi over 3, + +it also contains the operation +2 pi over 2. + +This is the operation of a +twofold axis, and that says I + +have to, in addition to the two +full rotation that sits + +here get twofold rotations in +the middle of every one of the + +translations T2. + +So actually, this is going to +be P2 superimposed on P3. + +And that's going to give me +these twofold axis and this + +threefold axis. + +And the only thing I have to do +is to show you what A 2 pi + +over 6 combined with +one of these + +translations is going to do. + +What is A 2 pi over 6 combined +with this translation? + +And it's going to be new +operation B 2 pi over 6, and + +it's going to be located at 1/2 +of T times the cotangent + +of 1/2 of 60 degrees, cotangent +of 30 degrees. + +And the cotangent of +30 degrees is 2. + +So this is going +to be at 1/2-- + +no, what do I want to say? + +This is 30 degrees. + +This is one. + +This is two. + +Cotangent of 30 degrees is this +over this, and that is-- + +no that's one. + +AUDIENCE: It's 2 pi +[? squared 3. ?] + +PROFESSOR: Yeah. + +OK, that's right. + +So actually, what that does is +to say the sixfold axis sits + +right up here. + +So I don't get any new sixfold +axis rotation of 60 degrees + +here, followed by translation +is the same as 60 degrees + +about here. + +So this is P6, and there is a +lot of pure rotation axes + +combined with lattices. + +We've got P1, P2, +P3, P4, and P6. + +Now, what I will do eventually, +when we're all + +done here, the plane groups are +not derived in any book or + +set of tables that +I am aware of. + +And next time, you will get +some notes that do this in + +very slow motion fashion +and give you all + +the individual steps. + +But the international tables +does give you diagrams of the + +resulting plane groups, very +nice carefully done figures + +along with the representative +arrangement of motifs that + +they generate. + +But we're not done yet. + +We have not let mirror planes +enter the picture. + +And so unless there is +dissension or debate, I'd like + +to consider what happens when we +take a mirror plane, and we + +can combine that with two +different kinds of lattices, a + +primitive rectangular net or +a centered rectangular net, + +which is called C. And in order +to do that, we need yet + +another combination theorem. + +Here are the lattice points, +and let me first derive the + +plane group that is called PM. + +And what I'll do +is to put the-- + +let me use a squiggly line here, +not because I'm excited + +or nervous about this, but just +to distinguish it from + +the edges of the cell. + +So here is the operation +sigma. + +The pattern that is going to +be displayed by the plane + +group is once again just the +pattern produced by a mirror + +plane hung at every +lattice point. + +But now we need a theorem. + +What we have here is the +operation of reflection, + +followed by a translation that +is perpendicular to the locus + +of the reflection line. + +And we will ask what is that? + +Again, you get the answer by +just looking at once and for + +all, and say, if here is +a first one and it is + +right-handed, and I reflect it +to one number to a second one, + +number two, which is +left-handed, and then move + +that by translation here to get +number three, which stays + +left-handed if I move +by translation. + +And ask now how was one +related to three. + +The chirality is changed. + +Reflection is the only thing +available to us, and lo and + +behold, if I say there is a new +mirror plane here, that + +tells me how this is related +to this, and this one is + +related to this one. + +And this to this and this to +this, so the answer to this + +question is that a reflection +combined with a perpendicular + +translation is a new reflection +operation sigma + +prime that is located at a +distance removed from the + +first by 1/2 of that +perpendicular translation. + +And again, it's a plane old +mirror plane just like the + +first one, but notice that the +disposition of objects + +relative to the mirror plane in +the center of the cell is + +quite distinct from the +disposition of objects + +relative to the first mirror +plane, so this is a second + +mirror plane. + +It is an independent mirror +plane from the first. + +So that is plane group PM. + +If there's symmetry in this +business, you might ask is + +there a plane group AM? + +The answer is yes in +three dimensions. + +There is a space group, PM, and +there's a space group AM. + +So there's AM and PM, and there +is symmetry, and all is + +well in the universe. + +OK, we're making great +progress here. + +And we'll be fairly well along +before we have to bring things + +to a close. + +Let's do the second addition +that's possible + +with a mirror plane. + +And that is to take a reflection +operation and add + +it to the translations that +are present in a centered + +rectangular net. + +We've already done all the work +for PM, so we can use + +that as a starting point. + +The pattern of this plane group +is going to look like a + +pair of objects related +by reflection. + +But now, we'll have an extra +pair hung at the centered + +lattice point as well. + +And the first thing we can note +is that this mirror plane + +is no longer independent +of the first one. + +What goes on at this mirror +plane is something that's + +related to what happens at the +origin lattice point and + +mirror plane, and therefore, +these two mirror planes are + +going to do the same thing. + +The pattern of this plane group, +we've taken a mirror + +plane and added it to a centered +rectangular net. + +This is called a C lattice, +standing for centered. + +And correspondingly, +the symbol for this + +plane group is CM. + +We know how this one is +related to this one. + +This one related to this one. + +And now, we've got something +of a problem. + +All of these motifs +are equivalent. + +How is this one related +to this one? + +Or in more general terms, what +we're asking is suppose I have + +a reflection operation sigma, +and I add the translation not + +at right angles to it, as I +did here, but place the + +translation at an angle +with respect to + +the reflection plane. + +So what we're going to do is to +take a first motif that's + +right-handed, reflect it to +a second one, which is + +left-handed. + +And then slide it along so that +it sits up in the same + +position relative to this +centered lattice point. + +So here's number three, +translation leaves it + +left-handed. + +So I've taken the operation of +reflection combined it with a + +translation that has a +perpendicular component plus a + +parallel component, +perpendicular and parallel + +meaning the orientation of these +two components of the + +translation relative to the +reflection operation. + +Anybody want to hazard a guess +on how that first one is + +related to the third one? + +Number one is right-handed. + +Number two is left-handed, +so it's got to + +be reflection, right? + +If I put a reflection plane in +here, this one ought to be + +tilted like this. + +That's not going +to do the job. + +Anybody got any idea? + +Yeah. + +AUDIENCE: What is that, +T, T1 [INAUDIBLE]? + +PROFESSOR: OK. + +T parallel plus T perpendicular +means it's a + +component of this translation. + +This is T. This has a part T +perpendicular, and it has a + +part T parallel relative to +the initial mirror plane. + +My friends, we have just +stumbled headlong over a new + +type of symmetry operation, +which we have discovered upon + +making this combination +of mirror plane + +with a centered lattice. + +And it's come up to smack us +rudely in the face even though + +we may not have been +clever enough to + +think of it in advance. + +This is a new type of operation, +and it is an + +operation that cannot be reduced +to one of the simple + +operations that we've +defined so far. + +You've got to take two steps +to get from number one to + +number three. + +The way you can do it is to +reflect along a locus that is + +one half of the way along the +perpendicular part of the + +translation, exactly the same +location as we found the + +symmetry plane positioned when +the translation was normal to + +the first mirror plane. + +But yet we can't put the +object down yet in the + +position that would be produced +by translation, + +because our translation is +inclined to the mirror plane. + +So I've got to take +a second step. + +Reflect. + +Don't yet put it down yet. + +Before you put it down, slide +it up parallel to the mirror + +plane by an amount that's +equal to the part of the + +translation that is parallel +to the mirror plane. + +So to summarize this before +all these words get too + +confusing, I'm saying that a +reflection operation combined + +with a general translation +that has a perpendicular + +component in the parallel +component relative to the + +locus of reflection is going to +be a new operation, which + +I'll write as sigma tau, +a reflection part and a + +translation tau that is parallel +to the mirror plane, + +and tau is equal to the part +of the translation that is + +parallel to the mirror plane. + +Astounding. + +This is a two-step operation +that cannot be described in + +terms simpler than saying +do two steps to do it. + +And we'll see as we go along, +particularly into a + +three-dimensional space, that +there are other two-step + +operations as well. + +Now you're all familiar with a +pattern like this, because in + +very short order when New +England's winter descends upon + +us, as you go slogging along +from your room into the + +Institute, your footprints will +make a pattern like that + +in the snow. + +Exactly what we've got here. + +Reflect across and slide. + +Reflect across and slide. + +Reflect across and slide, +and this is the + +glide component tau. + +And this is an operation that +is called a glide plane. + +And it's a new type of +symmetry operation. + +It can only exist in a +pattern, which has + +translational periodicity. + +And if we were not clever enough +to invent it, we would + +see it as soon as we combined a +mirror plane with a lattice + +that was non-primitive and had +a translation parallel to it. + +So it's a very, very +descriptive + +name, the glide plane. + +Reflect and glide, reflect and +glide, reflect and glide. + +It sounds like something you'd +be doing in the Arthur Murray + +dance studio, very melodious. + +Reflect and glide, reflect +and glide. + +It's a nice operation. + +All right, so what has happened +then when we add a + +mirror plane to a centered +rectangular net is that we get + +a new operation coming in, +something completely new. + +We've got a symbol to represent +an individual + +operation, sigma the symbol +for reflection with a + +subscript tau. + +And the pattern we've already +drawn, but let's do it again + +in a tidy fashion. + +Exactly as advertised, the pair +of objects related by + +reflection hung at every +lattice point of-- holy + +mackerel, look at this. + +That would give you +the willies. + +That's the nature +of the motif. + +Get that out of there. + +Mirror planes going through +the lattice points. + +Glide planes halfway +in between. + +The mirror lines and the glide +planes tell us how things on + +the right side, for example, +of the lattice point are + +related to the motif of opposite +chirality on the + +left-hand side of the centered +lattice point. + +And this is a plane group +that is called CM. + +AUDIENCE: Question. + +PROFESSOR: Yes, sir. + +AUDIENCE: How can we just define +a new operation that's + +a two-step. + +Seems like we could do this +forever, define two steps of + +any new operation, like you +said, with two steps. + +PROFESSOR: That's +a good question. + +We found this, because we +tripped headlong over it. + +And we say OK, there it is. + +We've got to deal with it. + +But you're right. + +How do you know that rotating +once reflecting, and then + +turning end over end three times +is not a new operation + +that cannot be decomposed, is +the word that's used for it, + +into something simpler? + +The answer is you've +got to try it. + +If they're there, when we make +these combinations of a + +symmetry operation, and now the +symmetry operation can be + +a two-step symmetry operation, +now that we've discovered + +that, combine that with lattice +and with rotation and + +with reflection, and ask what +is the relation between the + +motif at the beginning and +the motif at the end. + +If you can't describe it any +more simply other than a hop, + +skip and jump, you've got to +introduce the hop, skip, and + +jump as an element that +goes into the + +derivation of these groups. + +Now before you get concerned and +fill out an add/drop card, + +I have to reassure you that +there are a couple of two-step + +operations that we have yet to +discover, but there are no + +three-step operations +that are necessary. + +Whew. + +Feel better now, don't you? + +AUDIENCE: I was just going to +say it's kind of arbitrary, + +because you have a and b, you're +just applying the third + +[INAUDIBLE] + +T sub a and b, [INAUDIBLE] +trivial multiplication tables. + +PROFESSOR: Well, actually, +this is + +something that is distinct. + +I mean here is the group, and +you cannot describe the + +relation between everything that +is in this pattern, which + +was obtained simply by taking +the operation of reflection-- + +we know how to peacefully +coexist with that-- + +and placing that pair of objects +at lattice point of a + +centered rectangular net. + +So that's nothing +really freaky. + +I mean it's a straightforward +addition, but if it's a group, + +you have to know when you +combine all the operations + +pairwise that it'd be able to +show that these operations are + +members of a group. + +And the answer in terms of the +language of group theory, if + +you combine a reflection with +a translation that has a + +component that is parallel to +the reflection plane, then + +there is a new operation that +comes up that has to be in the + +group multiplication table, +and the operation has a + +reflection part and a +translation part. + +AUDIENCE: I have a question. + +PROFESSOR: Yes. + +AUDIENCE: How do we go from the +lower left to the upper + +right in one operation? + +PROFESSOR: The lower left +to the upper right. + +AUDIENCE: No, the upper +right diagonally. + +Across the diagonal, the upper +right corner of the square. + +PROFESSOR: Upper right here? + +AUDIENCE: Yeah. + +And the left-handed +guide below that. + +PROFESSOR: The left-handed +guide below. + +AUDIENCE: No. + +Down there. + +PROFESSOR: Where +is down there? + +AUDIENCE: The lowest +edge of the-- + +PROFESSOR: Down here? + +AUDIENCE: Yeah. + +PROFESSOR: OK. + +From this one to this one? + +AUDIENCE: Yeah. + +PROFESSOR: OK. + +What I can say is-- + +may sound like I'm slipping +off the hook too easily-- + +we said that we really only want +to consider operations + +that terminate within the cell, +and the way I get from + +here to here is to reflect and +then translate up by the + +diagonal translation. + +So that's something that +lies outside the cell. + +So I can always knock off +an integral number of + +translations or add on +an integral number of + +translations to any mapping +transformation, modulo T. OK? + +AUDIENCE: But surely, if you've +done, one operation + +then it's [INAUDIBLE]? + +PROFESSOR: From here to here? + +No, not necessarily. + +If I give you a very simple +pattern and plane group P1, + +and you ask how do I get from +this one here to this one that + +sits up here? + +If it's outside the cell, I've +got to go translation that's + +outside the cell. + +But it's not any new +translation or + +any new sort of operation. + +This is sort of in the +same category. + +Yeah. + +AUDIENCE: You can make +a glide plane in the + +center of the cell. + +PROFESSOR: Yeah, OK. + +Thank you. + +There is a glide operation that +goes from here to here + +and then translates up by +one full translation. + +But a glide operation that +is an integral number of + +translations says that +you're dealing with-- + +there's another object that is +removed by a translation that + +is the same thing. + +So it is first and that simpler +one that would be + +inside of the cell and would +be only the unique sort of + +translation you need +to consider. + +Thank you. + +That's a good question. + +That was a good answer +to his question. + +In fact, anybody want +to take over? + +I didn't do well on that one. + +Yeah. + +AUDIENCE: I was curious. + +Does the glide plane exist maybe +in this case because + +we're not using a +primitive cell? + +If you were to consider this +[INAUDIBLE] as hexagonal? + +PROFESSOR: OK, let me answer +that question by saying that + +that's our first encounter +with it. + +But now, that it exists, that +is a symmetry element, which + +we should consider adding to +lattices in addition to pure + +reflection. + +So let me proceed now to do +another plane group since we + +had discovered the operation +of glide. + +And I will take a primitive +rectangular lattice, and I + +will now add to the lattice +point, not a mirror plane, but + +a glide plane. + +OK. + +The pattern is going to look +like the pattern of glide, + +have things left and right +on either side + +of the glide plane. + +The same thing here. + +And there is the pattern. + +This is a pattern that's +called PG. + +And what I have to ask is what +is the guide operation sigma + +tau combined with, let's say +this translation T1. + +And the answer is that if I +reproduce number one to number + +two of opposite chirality by the +glide operation sigma tau + +and then follow that by T1 the +first and the third will be + +related by a new glide operation +sigma tau prime + +that's located at half +perpendicular part of the + +translation away +from the first. + +And that really is a +generalization of this + +relation here. + +If we make the pure reflection +operation a glide operation, + +combine it with a translation +that is perpendicular to it, + +it turns out that the net +result is a new glide + +operation, sigma tau prime. + +The two taus are equal, and this +occurs at one half of the + +translation T perpendicular +removed from the first. + +And the complete generalization +would be to say + +if I have a translation that +has a parallel part and a + +perpendicular part relative to +the glide plane, what I will + +get is a new glide operation +sigma prime that's located at + +1/2 of the perpendicular part +of the translation from the + +first, and it will pick up a +glide component that's equal + +to the original tau plus the +part of the translation that's + +parallel to the glide plane. + +So this now is this theorem +involving translation and + +reflection type operations +in its most general form. + +OK. + +So this is a new group called +CM, and it consists of pairs + +of objects. + +Sorry, we did that earlier. + +This is PG, pairs of objects +related by a glide plane, hung + +at every lattice point of the +primitive rectangular lattice. + +Is there a CG? + +Actually, there is not, and let +me show you why, and then + +I think we're just about +quitting time. + +If there is a centered lattice, +and I hang a glide + +plane at the lattice points, +we'll have glide planes in the + +locations of PG, the pattern +will look like objects + +repeated by glide. + +At this lattice point, and now +we're going to have another + +object hung at the centered +lattice point, and it's going + +to be in positions like this. + +Now, you can see just by looking +at the pattern that + +there is going to be-- + +whoops, what did I do here? + +I want to move this one up to +here, and I want to move this + +one up to here. + +This one should be +in this location. + +If I look at that pattern, what +I've done is to create + +halfway along the-- + +quarter of the way along +the translation a + +pure reflection operation. + +And I can find that using +my general theorem. + +I have a glide operation, +sigma tau. + +I combine with that the centered +translation, which is + +1/2 of T1 plus 1/2 of T2. + +I've taken 1/2 of T1 plus 1/2 +of T2, that's the centering + +translation, combined +that with sigma tau. + +I'll deftly jump to the side, so +the people against the wall + +can see it. + +I've taken a glide operation, +combined it with this + +translation. + +This should be a new reflection +type of operation + +that will be located at 1/2 of +the perpendicular part of the + +translation, and that's +at 1/2 of 1/2 of T1. + +And it will have a glide +component tau prime, which is + +the original tau, which +was 1/2 of T2. + +And to that we add the +parallel part of the + +translation, and that +is 1/2 of T2. + +So this is rewritten in slightly +different form, is + +simply a new glide plane sigma +prime, which has a glide + +component equal to the entire +translation T2 at + +1/4 quarter of T1. + +And this is the same as a +mirror plane at 1/4 T1. + +And this, if we compare +it with CM, is + +exactly the same thing. + +Identical to CM with an origin +shift of 1/4 T1. + +So there is no CG in what +we picked up in terms of + +rectangular nets and symmetry +planes is PM, PG, and CN. + +So there are three groups +involving orthogonal nets in a + +single symmetry plane. + +That is a good place +to wrap things up. + +And we'll next turn very, very +quickly equipped with a set of + +notes, which summarizes the +result, to what happens when + +we take two MM and put it into +a rectangular net, and take + +two MM and put it into a +centered rectangular net. + +And then things get interesting, +because we've got + +two planes. + +We can make a both +mirror planes. + +We can make them both glides, or +make one a mirror plane and + +one a glide plane. + +So there are three possibilities +with the + +addition of two MM to the net. + +More than enough for one day. + +It's Thursday. + +Take the rest of the +week and weekend + +off by doing no symmetry. + +There's no assignment, +and we'll have at + +it again next Tuesday. \ No newline at end of file diff --git a/pfDfriSjFbY.txt b/pfDfriSjFbY.txt new file mode 100644 index 0000000000000000000000000000000000000000..50374b58c30ab28592cea7525d8efb9468b2ec91 --- /dev/null +++ b/pfDfriSjFbY.txt @@ -0,0 +1,29827 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +So, welcome to creating video games CMS + + align:start position:0% +So, welcome to creating video games CMS + + + align:start position:0% +So, welcome to creating video games CMS +611 and 6073. Is everyone in the right + + align:start position:0% +611 and 6073. Is everyone in the right + + + align:start position:0% +611 and 6073. Is everyone in the right +class? Yeah. All right. + + align:start position:0% +class? Yeah. All right. + + + align:start position:0% +class? Yeah. All right. +Cool. + + align:start position:0% +Cool. + + + align:start position:0% +Cool. +Um, so this class is taught by um it's a + + align:start position:0% +Um, so this class is taught by um it's a + + + align:start position:0% +Um, so this class is taught by um it's a +comparative media studies course. So, + + align:start position:0% +comparative media studies course. So, + + + align:start position:0% +comparative media studies course. So, +we'll be talking a lot about the kinds + + align:start position:0% +we'll be talking a lot about the kinds + + + align:start position:0% +we'll be talking a lot about the kinds +of things that they talk about in + + align:start position:0% +of things that they talk about in + + + align:start position:0% +of things that they talk about in +comparative media studies. So, research + + align:start position:0% +comparative media studies. So, research + + + align:start position:0% +comparative media studies. So, research +and design practices, but as it relates + + align:start position:0% +and design practices, but as it relates + + + align:start position:0% +and design practices, but as it relates +to software engineering and in + + align:start position:0% +to software engineering and in + + + align:start position:0% +to software engineering and in +particular to developing video games, so + + align:start position:0% +particular to developing video games, so + + + align:start position:0% +particular to developing video games, so +digital video games um for basically + + align:start position:0% +digital video games um for basically + + + align:start position:0% +digital video games um for basically +screens. Um the CMS department has a lot + + align:start position:0% +screens. Um the CMS department has a lot + + + align:start position:0% +screens. Um the CMS department has a lot +of different really cool research + + align:start position:0% +of different really cool research + + + align:start position:0% +of different really cool research +project research labs that are a part of + + align:start position:0% +project research labs that are a part of + + + align:start position:0% +project research labs that are a part of +it and we are one of them. So, we're the + + align:start position:0% +it and we are one of them. So, we're the + + + align:start position:0% +it and we are one of them. So, we're the +MIT Game Lab. Basically, the whole MIT + + align:start position:0% +MIT Game Lab. Basically, the whole MIT + + + align:start position:0% +MIT Game Lab. Basically, the whole MIT +Game Lab staff um teaches this class + + align:start position:0% +Game Lab staff um teaches this class + + + align:start position:0% +Game Lab staff um teaches this class +together um because we really like each + + align:start position:0% +together um because we really like each + + + align:start position:0% +together um because we really like each +other and it's really fun. But also + + align:start position:0% +other and it's really fun. But also + + + align:start position:0% +other and it's really fun. But also +because there's a lot of you and it's a + + align:start position:0% +because there's a lot of you and it's a + + + align:start position:0% +because there's a lot of you and it's a +really big complicated class to teach, + + align:start position:0% +really big complicated class to teach, + + + align:start position:0% +really big complicated class to teach, +so we need all the extra support we can + + align:start position:0% +so we need all the extra support we can + + + align:start position:0% +so we need all the extra support we can +get. Um we teach classes on game design + + align:start position:0% +get. Um we teach classes on game design + + + align:start position:0% +get. Um we teach classes on game design +and game research. Those are all the + + align:start position:0% +and game research. Those are all the + + + align:start position:0% +and game research. Those are all the +course numbers that we teach other than + + align:start position:0% +course numbers that we teach other than + + + align:start position:0% +course numbers that we teach other than +this one. Um maybe you've taken one of + + align:start position:0% +this one. Um maybe you've taken one of + + + align:start position:0% +this one. Um maybe you've taken one of +these before. Maybe you're thinking + + align:start position:0% +these before. Maybe you're thinking + + + align:start position:0% +these before. Maybe you're thinking +about some other game courses you want + + align:start position:0% +about some other game courses you want + + + align:start position:0% +about some other game courses you want +to take in the future. So take a look at + + align:start position:0% +to take in the future. So take a look at + + + align:start position:0% +to take in the future. So take a look at +that. We also have Europ opportunities. + + align:start position:0% +that. We also have Europ opportunities. + + + align:start position:0% +that. We also have Europ opportunities. +So we'll advertise those to our classes + + align:start position:0% +So we'll advertise those to our classes + + + align:start position:0% +So we'll advertise those to our classes +as they come up. Um we do mentor core + + align:start position:0% +as they come up. Um we do mentor core + + + align:start position:0% +as they come up. Um we do mentor core +six students for the UAPs. What we + + align:start position:0% +six students for the UAPs. What we + + + align:start position:0% +six students for the UAPs. What we +usually ask is for you to bring to us an + + align:start position:0% +usually ask is for you to bring to us an + + + align:start position:0% +usually ask is for you to bring to us an +interesting research topic that you want + + align:start position:0% +interesting research topic that you want + + + align:start position:0% +interesting research topic that you want +to research and if we are also + + align:start position:0% +to research and if we are also + + + align:start position:0% +to research and if we are also +interested then cool a match is made. Um + + align:start position:0% +interested then cool a match is made. Um + + + align:start position:0% +interested then cool a match is made. Um +same thing when it comes to masters. So + + align:start position:0% +same thing when it comes to masters. So + + + align:start position:0% +same thing when it comes to masters. So +if you're if you're going to get your + + align:start position:0% +if you're if you're going to get your + + + align:start position:0% +if you're if you're going to get your +masters of engineering um here um in + + align:start position:0% +masters of engineering um here um in + + + align:start position:0% +masters of engineering um here um in +course 6 and you need a you want to do + + align:start position:0% +course 6 and you need a you want to do + + + align:start position:0% +course 6 and you need a you want to do +it in game design or game development, + + align:start position:0% +it in game design or game development, + + + align:start position:0% +it in game design or game development, +you need a mentor, we can be your + + align:start position:0% +you need a mentor, we can be your + + + align:start position:0% +you need a mentor, we can be your +mentor. Um we also host a lot of events + + align:start position:0% +mentor. Um we also host a lot of events + + + align:start position:0% +mentor. Um we also host a lot of events +um and outreach events are in guest + + align:start position:0% +um and outreach events are in guest + + + align:start position:0% +um and outreach events are in guest +lectures. A lot of the guest lectures + + align:start position:0% +lectures. A lot of the guest lectures + + + align:start position:0% +lectures. A lot of the guest lectures +will be part of this course that we'll + + align:start position:0% +will be part of this course that we'll + + + align:start position:0% +will be part of this course that we'll +be opening to the public as well for a + + align:start position:0% +be opening to the public as well for a + + + align:start position:0% +be opening to the public as well for a +few of them. Um, we've got Riot coming + + align:start position:0% +few of them. Um, we've got Riot coming + + + align:start position:0% +few of them. Um, we've got Riot coming +up in September. We've got a Japanese + + align:start position:0% +up in September. We've got a Japanese + + + align:start position:0% +up in September. We've got a Japanese +developer, Swary 65. Has anybody played + + align:start position:0% +developer, Swary 65. Has anybody played + + + align:start position:0% +developer, Swary 65. Has anybody played +Deadly + + align:start position:0% +Deadly + + + align:start position:0% +Deadly +Premonition? + + align:start position:0% +Premonition? + + + align:start position:0% +Premonition? +Yes. Uh, it's awesome and he is coming + + align:start position:0% +Yes. Uh, it's awesome and he is coming + + + align:start position:0% +Yes. Uh, it's awesome and he is coming +to talk about it. Um, and some other + + align:start position:0% +to talk about it. Um, and some other + + + align:start position:0% +to talk about it. Um, and some other +cool stuff. We also do a lot of events, + + align:start position:0% +cool stuff. We also do a lot of events, + + + align:start position:0% +cool stuff. We also do a lot of events, +so like game jams. Um, we'll have um an + + align:start position:0% +so like game jams. Um, we'll have um an + + + align:start position:0% +so like game jams. Um, we'll have um an +alumni panel. And the big thing, the + + align:start position:0% +alumni panel. And the big thing, the + + + align:start position:0% +alumni panel. And the big thing, the +next big thing is the Boston Festival of + + align:start position:0% +next big thing is the Boston Festival of + + + align:start position:0% +next big thing is the Boston Festival of +Indie Games is going to be on campus um + + align:start position:0% +Indie Games is going to be on campus um + + + align:start position:0% +Indie Games is going to be on campus um +in 11 days. So 200 developers are going + + align:start position:0% +in 11 days. So 200 developers are going + + + align:start position:0% +in 11 days. So 200 developers are going +to be showing off their games over in + + align:start position:0% +to be showing off their games over in + + + align:start position:0% +to be showing off their games over in +the J Johnson Activity Center and we'll + + align:start position:0% +the J Johnson Activity Center and we'll + + + align:start position:0% +the J Johnson Activity Center and we'll +have a a conference track going on here. + + align:start position:0% +have a a conference track going on here. + + + align:start position:0% +have a a conference track going on here. +So take a look at that. You'll get all + + align:start position:0% +So take a look at that. You'll get all + + + align:start position:0% +So take a look at that. You'll get all +that information as the course goes on. + + align:start position:0% +that information as the course goes on. + + + align:start position:0% +that information as the course goes on. +Um so next up, we just wanted to + + align:start position:0% +Um so next up, we just wanted to + + + align:start position:0% +Um so next up, we just wanted to +introduce ourselves and our our + + align:start position:0% +introduce ourselves and our our + + + align:start position:0% +introduce ourselves and our our +individual what we basically what we do + + align:start position:0% +individual what we basically what we do + + + align:start position:0% +individual what we basically what we do +and why we're teaching the course. So + + align:start position:0% +and why we're teaching the course. So + + + align:start position:0% +and why we're teaching the course. So +hi, I'm Philip Tan. Uh I've been + + align:start position:0% +hi, I'm Philip Tan. Uh I've been + + + align:start position:0% +hi, I'm Philip Tan. Uh I've been +teaching various game courses here in + + align:start position:0% +teaching various game courses here in + + + align:start position:0% +teaching various game courses here in +MIT for about 10 years now. Um I'm a + + align:start position:0% +MIT for about 10 years now. Um I'm a + + + align:start position:0% +MIT for about 10 years now. Um I'm a +research scientist over at the MIT game + + align:start position:0% +research scientist over at the MIT game + + + align:start position:0% +research scientist over at the MIT game +lab uh and uh you know work with work + + align:start position:0% +lab uh and uh you know work with work + + + align:start position:0% +lab uh and uh you know work with work +with all these f uh fine folk for many + + align:start position:0% +with all these f uh fine folk for many + + + align:start position:0% +with all these f uh fine folk for many +years. Up here are a couple of projects + + align:start position:0% +years. Up here are a couple of projects + + + align:start position:0% +years. Up here are a couple of projects +that I've worked on. Uh on the right is + + align:start position:0% +that I've worked on. Uh on the right is + + + align:start position:0% +that I've worked on. Uh on the right is +a game called the slower speed of light. + + align:start position:0% +a game called the slower speed of light. + + + align:start position:0% +a game called the slower speed of light. +If uh any of you are interested in + + align:start position:0% +If uh any of you are interested in + + + align:start position:0% +If uh any of you are interested in +relativistic speeds and simulating that + + align:start position:0% +relativistic speeds and simulating that + + + align:start position:0% +relativistic speeds and simulating that +on a computer uh you are welcome to + + align:start position:0% +on a computer uh you are welcome to + + + align:start position:0% +on a computer uh you are welcome to +check it out. Uh we also have an + + align:start position:0% +check it out. Uh we also have an + + + align:start position:0% +check it out. Uh we also have an +open-source version of our code that uh + + align:start position:0% +open-source version of our code that uh + + + align:start position:0% +open-source version of our code that uh +lives on GitHub. So you can download + + align:start position:0% +lives on GitHub. So you can download + + + align:start position:0% +lives on GitHub. So you can download +that version using the same tools that + + align:start position:0% +that version using the same tools that + + + align:start position:0% +that version using the same tools that +you're going to be using uh that you + + align:start position:0% +you're going to be using uh that you + + + align:start position:0% +you're going to be using uh that you +might end up using in in this class. But + + align:start position:0% +might end up using in in this class. But + + + align:start position:0% +might end up using in in this class. But +basically it's you travel near the speed + + align:start position:0% +basically it's you travel near the speed + + + align:start position:0% +basically it's you travel near the speed +of light, you see what it might look + + align:start position:0% +of light, you see what it might look + + + align:start position:0% +of light, you see what it might look +like. Um I've also um I also play a a + + align:start position:0% +like. Um I've also um I also play a a + + + align:start position:0% +like. Um I've also um I also play a a +lot of Starcraft. Anybody here play + + align:start position:0% +lot of Starcraft. Anybody here play + + + align:start position:0% +lot of Starcraft. Anybody here play +Starcraft? Few people. All right. Cool. + + align:start position:0% +Starcraft? Few people. All right. Cool. + + + align:start position:0% +Starcraft? Few people. All right. Cool. +Cool. All right. Um I I've been working + + align:start position:0% +Cool. All right. Um I I've been working + + + align:start position:0% +Cool. All right. Um I I've been working +with Blizzard uh this past year to uh + + align:start position:0% +with Blizzard uh this past year to uh + + + align:start position:0% +with Blizzard uh this past year to uh +work on their spectator interface. The + + align:start position:0% +work on their spectator interface. The + + + align:start position:0% +work on their spectator interface. The +idea is that there are a lot of people + + align:start position:0% +idea is that there are a lot of people + + + align:start position:0% +idea is that there are a lot of people +who watch esports right right now + + align:start position:0% +who watch esports right right now + + + align:start position:0% +who watch esports right right now +especially on Twitch. Who watches Twitch + + align:start position:0% +especially on Twitch. Who watches Twitch + + + align:start position:0% +especially on Twitch. Who watches Twitch +TV? Okay. All right. A lot lots of + + align:start position:0% +TV? Okay. All right. A lot lots of + + + align:start position:0% +TV? Okay. All right. A lot lots of +people uh esports specifically on Twitch + + align:start position:0% +people uh esports specifically on Twitch + + + align:start position:0% +people uh esports specifically on Twitch +TV or just like let's play. Okay. All + + align:start position:0% +TV or just like let's play. Okay. All + + + align:start position:0% +TV or just like let's play. Okay. All +right. a few um and you know those those + + align:start position:0% +right. a few um and you know those those + + + align:start position:0% +right. a few um and you know those those +are spectators just as if you were + + align:start position:0% +are spectators just as if you were + + + align:start position:0% +are spectators just as if you were +watching a football or hockey game on TV + + align:start position:0% +watching a football or hockey game on TV + + + align:start position:0% +watching a football or hockey game on TV +and they need infographics to come up in + + align:start position:0% +and they need infographics to come up in + + + align:start position:0% +and they need infographics to come up in +real time uh when something interesting + + align:start position:0% +real time uh when something interesting + + + align:start position:0% +real time uh when something interesting +is happening in a game. So I write code + + align:start position:0% +is happening in a game. So I write code + + + align:start position:0% +is happening in a game. So I write code +together with Europs uh to be able to + + align:start position:0% +together with Europs uh to be able to + + + align:start position:0% +together with Europs uh to be able to +bring up cool infographics to get to + + align:start position:0% +bring up cool infographics to get to + + + align:start position:0% +bring up cool infographics to get to +bring the hype basically. So uh that's + + align:start position:0% +bring the hype basically. So uh that's + + + align:start position:0% +bring the hype basically. So uh that's +me. + + align:start position:0% + + + + align:start position:0% + +Okay. Um hi I'm Sarah Broly. I'm the + + align:start position:0% +Okay. Um hi I'm Sarah Broly. I'm the + + + align:start position:0% +Okay. Um hi I'm Sarah Broly. I'm the +development director at the MIT Game + + align:start position:0% +development director at the MIT Game + + + align:start position:0% +development director at the MIT Game +Lab. Um, I came to the game lab out of + + align:start position:0% +Lab. Um, I came to the game lab out of + + + align:start position:0% +Lab. Um, I came to the game lab out of +industry where I've worked as a producer + + align:start position:0% +industry where I've worked as a producer + + + align:start position:0% +industry where I've worked as a producer +and a game designer and originally how I + + align:start position:0% +and a game designer and originally how I + + + align:start position:0% +and a game designer and originally how I +entered it was as a QA tester. So, um, + + align:start position:0% +entered it was as a QA tester. So, um, + + + align:start position:0% +entered it was as a QA tester. So, um, +I've held a lot of the jobs there. + + align:start position:0% +I've held a lot of the jobs there. + + + align:start position:0% +I've held a lot of the jobs there. +Um, I've worked with a lot of students + + align:start position:0% +Um, I've worked with a lot of students + + + align:start position:0% +Um, I've worked with a lot of students +on games when we were still running the + + align:start position:0% +on games when we were still running the + + + align:start position:0% +on games when we were still running the +summer program when we did Singapore MIT + + align:start position:0% +summer program when we did Singapore MIT + + + align:start position:0% +summer program when we did Singapore MIT +Gambit Game Lab. And now I have focused + + align:start position:0% +Gambit Game Lab. And now I have focused + + + align:start position:0% +Gambit Game Lab. And now I have focused +to mostly seeming to work on classes and + + align:start position:0% +to mostly seeming to work on classes and + + + align:start position:0% +to mostly seeming to work on classes and +teaching game design. So that's a lot of + + align:start position:0% +teaching game design. So that's a lot of + + + align:start position:0% +teaching game design. So that's a lot of +what I've been doing and what I've + + align:start position:0% +what I've been doing and what I've + + + align:start position:0% +what I've been doing and what I've +done. So I'm Rick. I'm the studio + + align:start position:0% +done. So I'm Rick. I'm the studio + + + align:start position:0% +done. So I'm Rick. I'm the studio +manager for the game lab. Um I teach + + align:start position:0% +manager for the game lab. Um I teach + + + align:start position:0% +manager for the game lab. Um I teach +this course. I co-e with Sarah um 617, + + align:start position:0% +this course. I co-e with Sarah um 617, + + + align:start position:0% +this course. I co-e with Sarah um 617, +our advanced game studio course. Um + + align:start position:0% +our advanced game studio course. Um + + + align:start position:0% +our advanced game studio course. Um +where you spend the entire semester + + align:start position:0% +where you spend the entire semester + + + align:start position:0% +where you spend the entire semester +making one game. Um and these are the + + align:start position:0% +making one game. Um and these are the + + + align:start position:0% +making one game. Um and these are the +games I've worked on at the game lab. Um + + align:start position:0% +games I've worked on at the game lab. Um + + + align:start position:0% +games I've worked on at the game lab. Um +I've worked on all sorts of different + + align:start position:0% +I've worked on all sorts of different + + + align:start position:0% +I've worked on all sorts of different +games. Um from anything to games about + + align:start position:0% +games. Um from anything to games about + + + align:start position:0% +games. Um from anything to games about +depression to games about identity. uh + + align:start position:0% +depression to games about identity. uh + + + align:start position:0% +depression to games about identity. uh +games that are demonstrating advanced 3D + + align:start position:0% +games that are demonstrating advanced 3D + + + align:start position:0% +games that are demonstrating advanced 3D +rendering techniques and uh conference + + align:start position:0% +rendering techniques and uh conference + + + align:start position:0% +rendering techniques and uh conference +games. Pax, a game that's played live + + align:start position:0% +games. Pax, a game that's played live + + + align:start position:0% +games. Pax, a game that's played live +that was played live action at um PAX + + align:start position:0% +that was played live action at um PAX + + + align:start position:0% +that was played live action at um PAX +East in 2009 at our booth there. Um so I + + align:start position:0% +East in 2009 at our booth there. Um so I + + + align:start position:0% +East in 2009 at our booth there. Um so I +I do digital and non-digital game + + align:start position:0% +I do digital and non-digital game + + + align:start position:0% +I do digital and non-digital game +design, but for the most part I'm + + align:start position:0% +design, but for the most part I'm + + + align:start position:0% +design, but for the most part I'm +studying and working on um project + + align:start position:0% +studying and working on um project + + + align:start position:0% +studying and working on um project +management. + + align:start position:0% +management. + + + align:start position:0% +management. +Uh hi, my name is Andrew Grant. I'm the + + align:start position:0% +Uh hi, my name is Andrew Grant. I'm the + + + align:start position:0% +Uh hi, my name is Andrew Grant. I'm the +technical director at the MIT Game Lab + + align:start position:0% +technical director at the MIT Game Lab + + + align:start position:0% +technical director at the MIT Game Lab +and help out with the classes, too. Um + + align:start position:0% +and help out with the classes, too. Um + + + align:start position:0% +and help out with the classes, too. Um +I'll probably be helping you out a + + align:start position:0% +I'll probably be helping you out a + + + align:start position:0% +I'll probably be helping you out a +little bit with technical issues or or + + align:start position:0% +little bit with technical issues or or + + + align:start position:0% +little bit with technical issues or or +what have you. Um, I was in the games + + align:start position:0% +what have you. Um, I was in the games + + + align:start position:0% +what have you. Um, I was in the games +industry. Started with Sarah at Looking + + align:start position:0% +industry. Started with Sarah at Looking + + + align:start position:0% +industry. Started with Sarah at Looking +Glass and moved to Dream Dreamworks + + align:start position:0% +Glass and moved to Dream Dreamworks + + + align:start position:0% +Glass and moved to Dream Dreamworks +Interactive. And after that kind of got + + align:start position:0% +Interactive. And after that kind of got + + + align:start position:0% +Interactive. And after that kind of got +burned out to be honest. It's a pretty + + align:start position:0% +burned out to be honest. It's a pretty + + + align:start position:0% +burned out to be honest. It's a pretty +rough industry sometimes. Spent about 10 + + align:start position:0% +rough industry sometimes. Spent about 10 + + + align:start position:0% +rough industry sometimes. Spent about 10 +years consulting and I kept coming back + + align:start position:0% +years consulting and I kept coming back + + + align:start position:0% +years consulting and I kept coming back +to games and coming back to games. And + + align:start position:0% +to games and coming back to games. And + + + align:start position:0% +to games and coming back to games. And +so when I got the opportunity to come + + align:start position:0% +so when I got the opportunity to come + + + align:start position:0% +so when I got the opportunity to come +into the game lab, I said, "Well, yes." + + align:start position:0% +into the game lab, I said, "Well, yes." + + + align:start position:0% +into the game lab, I said, "Well, yes." +Um, so anyway, here I am. Um, I've been + + align:start position:0% +Um, so anyway, here I am. Um, I've been + + + align:start position:0% +Um, so anyway, here I am. Um, I've been +playing and making games all my life and + + align:start position:0% +playing and making games all my life and + + + align:start position:0% +playing and making games all my life and +I think we'll have fun doing it this + + align:start position:0% +I think we'll have fun doing it this + + + align:start position:0% +I think we'll have fun doing it this +semester. + + align:start position:0% +semester. + + + align:start position:0% +semester. +And if you could stand up, our TA is + + align:start position:0% +And if you could stand up, our TA is + + + align:start position:0% +And if you could stand up, our TA is +Pelina. Wave. Say hi. uh she'll be + + align:start position:0% +Pelina. Wave. Say hi. uh she'll be + + + align:start position:0% +Pelina. Wave. Say hi. uh she'll be +helping with all the administrative + + align:start position:0% +helping with all the administrative + + + align:start position:0% +helping with all the administrative +stuff um helping us with grading and + + align:start position:0% +stuff um helping us with grading and + + + align:start position:0% +stuff um helping us with grading and +she'll also be helping with any + + align:start position:0% +she'll also be helping with any + + + align:start position:0% +she'll also be helping with any +questions you might have about some of + + align:start position:0% +questions you might have about some of + + + align:start position:0% +questions you might have about some of +the technology that we're using too. She + + align:start position:0% +the technology that we're using too. She + + + align:start position:0% +the technology that we're using too. She +took the course uh this past last year. + + align:start position:0% +took the course uh this past last year. + + + align:start position:0% +took the course uh this past last year. +Great. So get down your pencils. This is + + align:start position:0% +Great. So get down your pencils. This is + + + align:start position:0% +Great. So get down your pencils. This is +the cheat sheet, the oneline version of + + align:start position:0% +the cheat sheet, the oneline version of + + + align:start position:0% +the cheat sheet, the oneline version of +the class. If you learn anything, you + + align:start position:0% +the class. If you learn anything, you + + + align:start position:0% +the class. If you learn anything, you +learn this. Um, when you're working in + + align:start position:0% +learn this. Um, when you're working in + + + align:start position:0% +learn this. Um, when you're working in +this class, the best way to succeed is + + align:start position:0% +this class, the best way to succeed is + + + align:start position:0% +this class, the best way to succeed is +working face to face, testing your games + + align:start position:0% +working face to face, testing your games + + + align:start position:0% +working face to face, testing your games +often, prioritize, integrate, and + + align:start position:0% +often, prioritize, integrate, and + + + align:start position:0% +often, prioritize, integrate, and +cutting features early. Sleeping is + + align:start position:0% +cutting features early. Sleeping is + + + align:start position:0% +cutting features early. Sleeping is +awesome. Um, avoid doing 3D, avoid doing + + align:start position:0% +awesome. Um, avoid doing 3D, avoid doing + + + align:start position:0% +awesome. Um, avoid doing 3D, avoid doing +network code, and please use version + + align:start position:0% +network code, and please use version + + + align:start position:0% +network code, and please use version +control. Um, we're actually gonna + + align:start position:0% +control. Um, we're actually gonna + + + align:start position:0% +control. Um, we're actually gonna +require all of this, but every year a + + align:start position:0% +require all of this, but every year a + + + align:start position:0% +require all of this, but every year a +team or two doesn't do one of these + + align:start position:0% +team or two doesn't do one of these + + + align:start position:0% +team or two doesn't do one of these +things, and it's okay, but they + + align:start position:0% +things, and it's okay, but they + + + align:start position:0% +things, and it's okay, but they +struggle. So if you do all these things + + align:start position:0% +struggle. So if you do all these things + + + align:start position:0% +struggle. So if you do all these things +through the through the uh the semester, + + align:start position:0% +through the through the uh the semester, + + + align:start position:0% +through the through the uh the semester, +you'll do really really well. Uh from + + align:start position:0% +you'll do really really well. Uh from + + + align:start position:0% +you'll do really really well. Uh from +now Yeah, please. + + align:start position:0% +now Yeah, please. + + + align:start position:0% +now Yeah, please. +What was the question? + + align:start position:0% +What was the question? + + + align:start position:0% +What was the question? +Oh, the slides. Yeah, all the slides + + align:start position:0% +Oh, the slides. Yeah, all the slides + + + align:start position:0% +Oh, the slides. Yeah, all the slides +will be available on Stellar. Um we're + + align:start position:0% +will be available on Stellar. Um we're + + + align:start position:0% +will be available on Stellar. Um we're +posting all of our slides to Stellar. Um + + align:start position:0% +posting all of our slides to Stellar. Um + + + align:start position:0% +posting all of our slides to Stellar. Um +I don't actually expect you to take + + align:start position:0% +I don't actually expect you to take + + + align:start position:0% +I don't actually expect you to take +notes on all these things, but it's + + align:start position:0% +notes on all these things, but it's + + + align:start position:0% +notes on all these things, but it's +awesome if you do. I remember that way. + + align:start position:0% +awesome if you do. I remember that way. + + + align:start position:0% +awesome if you do. I remember that way. +This is 140 characters. This is this is + + align:start position:0% +This is 140 characters. This is this is + + + align:start position:0% +This is 140 characters. This is this is +actually his this was actually uh + + align:start position:0% +actually his this was actually uh + + + align:start position:0% +actually his this was actually uh +Philip's tweet from uh from last night + + align:start position:0% +Philip's tweet from uh from last night + + + align:start position:0% +Philip's tweet from uh from last night +in case anybody was was following him + + align:start position:0% +in case anybody was was following him + + + align:start position:0% +in case anybody was was following him +already. + + align:start position:0% +already. + + + align:start position:0% +already. +Um actually yeah so uh the next bit um + + align:start position:0% +Um actually yeah so uh the next bit um + + + align:start position:0% +Um actually yeah so uh the next bit um +of administia we're going to go over the + + align:start position:0% +of administia we're going to go over the + + + align:start position:0% +of administia we're going to go over the +syllabus a little bit. It's in front of + + align:start position:0% +syllabus a little bit. It's in front of + + + align:start position:0% +syllabus a little bit. It's in front of +you right there. If you have any + + align:start position:0% +you right there. If you have any + + + align:start position:0% +you right there. If you have any +questions feel free to interrupt fellow + + align:start position:0% +questions feel free to interrupt fellow + + + align:start position:0% +questions feel free to interrupt fellow +instructors if I say something wrong or + + align:start position:0% +instructors if I say something wrong or + + + align:start position:0% +instructors if I say something wrong or +if you want to say hey but also this + + align:start position:0% +if you want to say hey but also this + + + align:start position:0% +if you want to say hey but also this +please + + align:start position:0% +please + + + align:start position:0% +please +do. So first thing this the course is + + align:start position:0% +do. So first thing this the course is + + + align:start position:0% +do. So first thing this the course is +structured into four game projects. So, + + align:start position:0% +structured into four game projects. So, + + + align:start position:0% +structured into four game projects. So, +you're going to make be making four + + align:start position:0% +you're going to make be making four + + + align:start position:0% +you're going to make be making four +projects over the course of the + + align:start position:0% +projects over the course of the + + + align:start position:0% +projects over the course of the +semester. Our first three projects are + + align:start position:0% +semester. Our first three projects are + + + align:start position:0% +semester. Our first three projects are +about two weeks each. The third project + + align:start position:0% +about two weeks each. The third project + + + align:start position:0% +about two weeks each. The third project +is a little bit longer if you decide to + + align:start position:0% +is a little bit longer if you decide to + + + align:start position:0% +is a little bit longer if you decide to +work over the student holiday. Um, and + + align:start position:0% +work over the student holiday. Um, and + + + align:start position:0% +work over the student holiday. Um, and +then project four is our our final + + align:start position:0% +then project four is our our final + + + align:start position:0% +then project four is our our final +project, our main project. And that + + align:start position:0% +project, our main project. And that + + + align:start position:0% +project, our main project. And that +project's going to be done um for a + + align:start position:0% +project's going to be done um for a + + + align:start position:0% +project's going to be done um for a +client who'll be coming in to talk about + + align:start position:0% +client who'll be coming in to talk about + + + align:start position:0% +client who'll be coming in to talk about +what he works works on um later today. + + align:start position:0% +what he works works on um later today. + + + align:start position:0% +what he works works on um later today. +Um so, your first project is a + + align:start position:0% +Um so, your first project is a + + + align:start position:0% +Um so, your first project is a +non-digital project. It's a prototype. + + align:start position:0% +non-digital project. It's a prototype. + + + align:start position:0% +non-digital project. It's a prototype. +Your second and thirds are are small + + align:start position:0% +Your second and thirds are are small + + + align:start position:0% +Your second and thirds are are small +short digital prototypes. So making a a + + align:start position:0% +short digital prototypes. So making a a + + + align:start position:0% +short digital prototypes. So making a a +a digital game very quickly. Your fourth + + align:start position:0% +a digital game very quickly. Your fourth + + + align:start position:0% +a digital game very quickly. Your fourth +one is a longer time period project, but + + align:start position:0% +one is a longer time period project, but + + + align:start position:0% +one is a longer time period project, but +it should be about the same amount of of + + align:start position:0% +it should be about the same amount of of + + + align:start position:0% +it should be about the same amount of of +um features, the same amount of um work, + + align:start position:0% +um features, the same amount of um work, + + + align:start position:0% +um features, the same amount of um work, +the same amount of gameplay as the first + + align:start position:0% +the same amount of gameplay as the first + + + align:start position:0% +the same amount of gameplay as the first +three. It's just you had a lot more time + + align:start position:0% +three. It's just you had a lot more time + + + align:start position:0% +three. It's just you had a lot more time +to actually do it right and to do it + + align:start position:0% +to actually do it right and to do it + + + align:start position:0% +to actually do it right and to do it +well and to polish on it and iterate on + + align:start position:0% +well and to polish on it and iterate on + + + align:start position:0% +well and to polish on it and iterate on +it. + + align:start position:0% +it. + + + align:start position:0% +it. +Um at the end of today we'll talk about + + align:start position:0% +Um at the end of today we'll talk about + + + align:start position:0% +Um at the end of today we'll talk about +what we mean by these common themes. + + align:start position:0% +what we mean by these common themes. + + + align:start position:0% +what we mean by these common themes. +This common theme meaning meaning + + align:start position:0% +This common theme meaning meaning + + + align:start position:0% +This common theme meaning meaning +meaning what did I say meaningful + + align:start position:0% +meaning what did I say meaningful + + + align:start position:0% +meaning what did I say meaningful +decision-m or meaningful decisions in + + align:start position:0% +decision-m or meaningful decisions in + + + align:start position:0% +decision-m or meaningful decisions in +games. Um and when at each time we start + + align:start position:0% +games. Um and when at each time we start + + + align:start position:0% +games. Um and when at each time we start +a project our first project starts on on + + align:start position:0% +a project our first project starts on on + + + align:start position:0% +a project our first project starts on on +Monday we'll introduce the theme in more + + align:start position:0% +Monday we'll introduce the theme in more + + + align:start position:0% +Monday we'll introduce the theme in more +detail and talk a little bit more about + + align:start position:0% +detail and talk a little bit more about + + + align:start position:0% +detail and talk a little bit more about +it but you can see all of the details + + align:start position:0% +it but you can see all of the details + + + align:start position:0% +it but you can see all of the details +about the projects that we have + + align:start position:0% +about the projects that we have + + + align:start position:0% +about the projects that we have +available for you at Stellar right now. + + align:start position:0% +available for you at Stellar right now. + + + align:start position:0% +available for you at Stellar right now. +A grading rubric um for each project is + + align:start position:0% +A grading rubric um for each project is + + + align:start position:0% +A grading rubric um for each project is +largely team focused. So all of your + + align:start position:0% +largely team focused. So all of your + + + align:start position:0% +largely team focused. So all of your +projects are worked in in teams. Um they + + align:start position:0% +projects are worked in in teams. Um they + + + align:start position:0% +projects are worked in in teams. Um they +start in small teams and get a bit + + align:start position:0% +start in small teams and get a bit + + + align:start position:0% +start in small teams and get a bit +larger. Um you'll see every each of + + align:start position:0% +larger. Um you'll see every each of + + + align:start position:0% +larger. Um you'll see every each of +these lines is 20% of the grade. So the + + align:start position:0% +these lines is 20% of the grade. So the + + + align:start position:0% +these lines is 20% of the grade. So the +actual working of the game is only 20% + + align:start position:0% +actual working of the game is only 20% + + + align:start position:0% +actual working of the game is only 20% +of your game of your grade. Um following + + align:start position:0% +of your game of your grade. Um following + + + align:start position:0% +of your game of your grade. Um following +our iterative the iterative design + + align:start position:0% +our iterative the iterative design + + + align:start position:0% +our iterative the iterative design +process that we'll be talking about + + align:start position:0% +process that we'll be talking about + + + align:start position:0% +process that we'll be talking about +using the project management practices + + align:start position:0% +using the project management practices + + + align:start position:0% +using the project management practices +that we'll be talking about. um doing a + + align:start position:0% +that we'll be talking about. um doing a + + + align:start position:0% +that we'll be talking about. um doing a +a good um presentation, a group + + align:start position:0% +a good um presentation, a group + + + align:start position:0% +a good um presentation, a group +postmortem presentation about your game + + align:start position:0% +postmortem presentation about your game + + + align:start position:0% +postmortem presentation about your game +is another 20%. And then every student + + align:start position:0% +is another 20%. And then every student + + + align:start position:0% +is another 20%. And then every student +will write an individual postmortem, + + align:start position:0% +will write an individual postmortem, + + + align:start position:0% +will write an individual postmortem, +their own like one to two page essay um + + align:start position:0% +their own like one to two page essay um + + + align:start position:0% +their own like one to two page essay um +at the end of at turned in at the same + + align:start position:0% +at the end of at turned in at the same + + + align:start position:0% +at the end of at turned in at the same +time as every project. And what we're + + align:start position:0% +time as every project. And what we're + + + align:start position:0% +time as every project. And what we're +asking for for those for all these + + align:start position:0% +asking for for those for all these + + + align:start position:0% +asking for for those for all these +things is we want to know we want to + + align:start position:0% +things is we want to know we want to + + + align:start position:0% +things is we want to know we want to +know about your process. We want to know + + align:start position:0% +know about your process. We want to know + + + align:start position:0% +know about your process. We want to know +how you made the game, what challenges + + align:start position:0% +how you made the game, what challenges + + + align:start position:0% +how you made the game, what challenges +you had while you were making the game. + + align:start position:0% +you had while you were making the game. + + + align:start position:0% +you had while you were making the game. +Um, what difficulties you faced, how you + + align:start position:0% +Um, what difficulties you faced, how you + + + align:start position:0% +Um, what difficulties you faced, how you +surpassed them, and even better, what + + align:start position:0% +surpassed them, and even better, what + + + align:start position:0% +surpassed them, and even better, what +you were going to do in the future if + + align:start position:0% +you were going to do in the future if + + + align:start position:0% +you were going to do in the future if +when you either go into the industry or + + align:start position:0% +when you either go into the industry or + + + align:start position:0% +when you either go into the industry or +go into another software engineering + + align:start position:0% +go into another software engineering + + + align:start position:0% +go into another software engineering +project or another class, what would you + + align:start position:0% +project or another class, what would you + + + align:start position:0% +project or another class, what would you +do differently knowing after after + + align:start position:0% +do differently knowing after after + + + align:start position:0% +do differently knowing after after +basically after the experience you just + + align:start position:0% +basically after the experience you just + + + align:start position:0% +basically after the experience you just +had? Um, so 80% of your grade is team + + align:start position:0% +had? Um, so 80% of your grade is team + + + align:start position:0% +had? Um, so 80% of your grade is team +delivered, 20% of your grade is your own + + align:start position:0% +delivered, 20% of your grade is your own + + + align:start position:0% +delivered, 20% of your grade is your own +work. + + align:start position:0% +work. + + + align:start position:0% +work. +So, speaking of in-class expectations, + + align:start position:0% +So, speaking of in-class expectations, + + + align:start position:0% +So, speaking of in-class expectations, +the class is a three-hour class. Holy + + align:start position:0% +the class is a three-hour class. Holy + + + align:start position:0% +the class is a three-hour class. Holy +crap. And it runs twice a week. Um, + + align:start position:0% +crap. And it runs twice a week. Um, + + + align:start position:0% +crap. And it runs twice a week. Um, +class time is actually allotted for your + + align:start position:0% +class time is actually allotted for your + + + align:start position:0% +class time is actually allotted for your +work in Teams. Um, we don't expect you + + align:start position:0% +work in Teams. Um, we don't expect you + + + align:start position:0% +work in Teams. Um, we don't expect you +to get your games actually built + + align:start position:0% +to get your games actually built + + + align:start position:0% +to get your games actually built +entirely within class, but important + + align:start position:0% +entirely within class, but important + + + align:start position:0% +entirely within class, but important +team meetings, um, test sessions, um, + + align:start position:0% +team meetings, um, test sessions, um, + + + align:start position:0% +team meetings, um, test sessions, um, +code review, you're going to generally + + align:start position:0% +code review, you're going to generally + + + align:start position:0% +code review, you're going to generally +have a lot of time in class to do a lot + + align:start position:0% +have a lot of time in class to do a lot + + + align:start position:0% +have a lot of time in class to do a lot +of that stuff. For projects one and two, + + align:start position:0% +of that stuff. For projects one and two, + + + align:start position:0% +of that stuff. For projects one and two, +you'll probably have about 60 minutes at + + align:start position:0% +you'll probably have about 60 minutes at + + + align:start position:0% +you'll probably have about 60 minutes at +the most per session to work on your + + align:start position:0% +the most per session to work on your + + + align:start position:0% +the most per session to work on your +your your team work outside of a a a + + align:start position:0% +your your team work outside of a a a + + + align:start position:0% +your your team work outside of a a a +activity, but we're also going to have a + + align:start position:0% +activity, but we're also going to have a + + + align:start position:0% +activity, but we're also going to have a +lot of activities where you're doing + + align:start position:0% +lot of activities where you're doing + + + align:start position:0% +lot of activities where you're doing +some of the some of the the the work + + align:start position:0% +some of the some of the the the work + + + align:start position:0% +some of the some of the the the work +that's required in each project as part + + align:start position:0% +that's required in each project as part + + + align:start position:0% +that's required in each project as part +of like a guided activity that we're + + align:start position:0% +of like a guided activity that we're + + + align:start position:0% +of like a guided activity that we're +going to run. Um so it's actually a + + align:start position:0% +going to run. Um so it's actually a + + + align:start position:0% +going to run. Um so it's actually a +little bit more than 60 minutes. + + align:start position:0% +little bit more than 60 minutes. + + + align:start position:0% +little bit more than 60 minutes. +Products three and four, uh we're + + align:start position:0% +Products three and four, uh we're + + + align:start position:0% +Products three and four, uh we're +probably going to have about 90 minutes + + align:start position:0% +probably going to have about 90 minutes + + + align:start position:0% +probably going to have about 90 minutes +per session for working in your teams. + + align:start position:0% +per session for working in your teams. + + + align:start position:0% +per session for working in your teams. +Um and that's going to generally be at + + align:start position:0% +Um and that's going to generally be at + + + align:start position:0% +Um and that's going to generally be at +the end of class. In the beginning of + + align:start position:0% +the end of class. In the beginning of + + + align:start position:0% +the end of class. In the beginning of +class, we're going to have um usually a + + align:start position:0% +class, we're going to have um usually a + + + align:start position:0% +class, we're going to have um usually a +guest lecture for those u last two + + align:start position:0% +guest lecture for those u last two + + + align:start position:0% +guest lecture for those u last two +projects. Um and then we'll have a place + + align:start position:0% +projects. Um and then we'll have a place + + + align:start position:0% +projects. Um and then we'll have a place +a play test session and then it'll just + + align:start position:0% +a play test session and then it'll just + + + align:start position:0% +a play test session and then it'll just +be open work. Um our original classroom + + align:start position:0% +be open work. Um our original classroom + + + align:start position:0% +be open work. Um our original classroom +had flat tables. This classroom that + + align:start position:0% +had flat tables. This classroom that + + + align:start position:0% +had flat tables. This classroom that +moved. This classroom does not. So it'll + + align:start position:0% +moved. This classroom does not. So it'll + + + align:start position:0% +moved. This classroom does not. So it'll +be interesting. I don't know if it's got + + align:start position:0% +be interesting. I don't know if it's got + + + align:start position:0% +be interesting. I don't know if it's got +power on any of the stations. But the + + align:start position:0% +power on any of the stations. But the + + + align:start position:0% +power on any of the stations. But the +the short version of it is bring your + + align:start position:0% +the short version of it is bring your + + + align:start position:0% +the short version of it is bring your +dev development station to class if you + + align:start position:0% +dev development station to class if you + + + align:start position:0% +dev development station to class if you +can. If it's a laptop, bring it to + + align:start position:0% +can. If it's a laptop, bring it to + + + align:start position:0% +can. If it's a laptop, bring it to +class. You'll be using it a lot starting + + align:start position:0% +class. You'll be using it a lot starting + + + align:start position:0% +class. You'll be using it a lot starting +Monday. Um, we're actually starting two + + align:start position:0% +Monday. Um, we're actually starting two + + + align:start position:0% +Monday. Um, we're actually starting two +Mondays from + + align:start position:0% +Mondays from + + + align:start position:0% +Mondays from +now. And the other thing, teamwork is + + align:start position:0% +now. And the other thing, teamwork is + + + align:start position:0% +now. And the other thing, teamwork is +the heart of this course and actually + + align:start position:0% +the heart of this course and actually + + + align:start position:0% +the heart of this course and actually +participation is the heart of this + + align:start position:0% +participation is the heart of this + + + align:start position:0% +participation is the heart of this +course. So even though we're in this + + align:start position:0% +course. So even though we're in this + + + align:start position:0% +course. So even though we're in this +tiered thing and I hate giving lectures + + align:start position:0% +tiered thing and I hate giving lectures + + + align:start position:0% +tiered thing and I hate giving lectures +to people this way, um, we're going to + + align:start position:0% +to people this way, um, we're going to + + + align:start position:0% +to people this way, um, we're going to +ask you to talk back to us a little bit. + + align:start position:0% +ask you to talk back to us a little bit. + + + align:start position:0% +ask you to talk back to us a little bit. +So fill in the the gaps when you come + + align:start position:0% +So fill in the the gaps when you come + + + align:start position:0% +So fill in the the gaps when you come +in. Um, participation is actually very + + align:start position:0% +in. Um, participation is actually very + + + align:start position:0% +in. Um, participation is actually very +important. Participation, class + + align:start position:0% +important. Participation, class + + + align:start position:0% +important. Participation, class +participation, so showing up um to class + + align:start position:0% +participation, so showing up um to class + + + align:start position:0% +participation, so showing up um to class +on time um showing up to class at all + + align:start position:0% +on time um showing up to class at all + + + align:start position:0% +on time um showing up to class at all +and participating in class is 25% of the + + align:start position:0% +and participating in class is 25% of the + + + align:start position:0% +and participating in class is 25% of the +grade. So speaking of that, attendance + + align:start position:0% +grade. So speaking of that, attendance + + + align:start position:0% +grade. So speaking of that, attendance +um you will be penalized if you miss + + align:start position:0% +um you will be penalized if you miss + + + align:start position:0% +um you will be penalized if you miss +more than three classes without + + align:start position:0% +more than three classes without + + + align:start position:0% +more than three classes without +justification. Uh so what is that + + align:start position:0% +justification. Uh so what is that + + + align:start position:0% +justification. Uh so what is that +justification? It's largely sick. If + + align:start position:0% +justification? It's largely sick. If + + + align:start position:0% +justification? It's largely sick. If +you're sick, we don't want you here. + + align:start position:0% +you're sick, we don't want you here. + + + align:start position:0% +you're sick, we don't want you here. +Stay home. Um don't make us sick. Don't + + align:start position:0% +Stay home. Um don't make us sick. Don't + + + align:start position:0% +Stay home. Um don't make us sick. Don't +make your team sick. Um he's really + + align:start position:0% +make your team sick. Um he's really + + + align:start position:0% +make your team sick. Um he's really +strict about that. Uh I'm invincible. I + + align:start position:0% +strict about that. Uh I'm invincible. I + + + align:start position:0% +strict about that. Uh I'm invincible. I +won't get sick, but everybody else will. + + align:start position:0% +won't get sick, but everybody else will. + + + align:start position:0% +won't get sick, but everybody else will. +Um do not be late. Um again, we're + + align:start position:0% +Um do not be late. Um again, we're + + + align:start position:0% +Um do not be late. Um again, we're +recording. Um, we're we have very + + align:start position:0% +recording. Um, we're we have very + + + align:start position:0% +recording. Um, we're we have very +important guest lectures who are in our + + align:start position:0% +important guest lectures who are in our + + + align:start position:0% +important guest lectures who are in our +network that we'd really like them to to + + align:start position:0% +network that we'd really like them to to + + + align:start position:0% +network that we'd really like them to to +enjoy being here. So, I really hate it + + align:start position:0% +enjoy being here. So, I really hate it + + + align:start position:0% +enjoy being here. So, I really hate it +when people show up in the middle of a + + align:start position:0% +when people show up in the middle of a + + + align:start position:0% +when people show up in the middle of a +guest lecture. It makes me feel like a + + align:start position:0% +guest lecture. It makes me feel like a + + + align:start position:0% +guest lecture. It makes me feel like a +jerk for asking them to talk to MIT. So, + + align:start position:0% +jerk for asking them to talk to MIT. So, + + + align:start position:0% +jerk for asking them to talk to MIT. So, +don't show up late, but do show up. So, + + align:start position:0% +don't show up late, but do show up. So, + + + align:start position:0% +don't show up late, but do show up. So, +um, if for whatever reason the doors are + + align:start position:0% +um, if for whatever reason the doors are + + + align:start position:0% +um, if for whatever reason the doors are +locked, it really just means, hey, + + align:start position:0% +locked, it really just means, hey, + + + align:start position:0% +locked, it really just means, hey, +there's a guest lecture here and coming + + align:start position:0% +there's a guest lecture here and coming + + + align:start position:0% +there's a guest lecture here and coming +in is going to disrupt things. The doors + + align:start position:0% +in is going to disrupt things. The doors + + + align:start position:0% +in is going to disrupt things. The doors +will get unlocked. Uh I don't expect to + + align:start position:0% +will get unlocked. Uh I don't expect to + + + align:start position:0% +will get unlocked. Uh I don't expect to +have have to use that, but if I will, I + + align:start position:0% +have have to use that, but if I will, I + + + align:start position:0% +have have to use that, but if I will, I +will. Um and usually guest lectures and + + align:start position:0% +will. Um and usually guest lectures and + + + align:start position:0% +will. Um and usually guest lectures and +about 2:10. Uh so you can come back some + + align:start position:0% +about 2:10. Uh so you can come back some + + + align:start position:0% +about 2:10. Uh so you can come back some +come into class later to work and + + align:start position:0% +come into class later to work and + + + align:start position:0% +come into class later to work and +actually get counted for the rest of + + align:start position:0% +actually get counted for the rest of + + + align:start position:0% +actually get counted for the rest of +that day. So I'd rather you come in + + align:start position:0% +that day. So I'd rather you come in + + + align:start position:0% +that day. So I'd rather you come in +later than at like 1:15 while somebody's + + align:start position:0% +later than at like 1:15 while somebody's + + + align:start position:0% +later than at like 1:15 while somebody's +talking up here. Um class is generally + + align:start position:0% +talking up here. Um class is generally + + + align:start position:0% +talking up here. Um class is generally +going to start the lectures are + + align:start position:0% +going to start the lectures are + + + align:start position:0% +going to start the lectures are +generally going to start at 110. We'll + + align:start position:0% +generally going to start at 110. We'll + + + align:start position:0% +generally going to start at 110. We'll +do announcements at 10:05. Um if that + + align:start position:0% +do announcements at 10:05. Um if that + + + align:start position:0% +do announcements at 10:05. Um if that +makes a difference because I know a lot + + align:start position:0% +makes a difference because I know a lot + + + align:start position:0% +makes a difference because I know a lot +of people are coming in from recitations + + align:start position:0% +of people are coming in from recitations + + + align:start position:0% +of people are coming in from recitations +and + + align:start position:0% +and + + + align:start position:0% +and +whatnot. Um, the other thing, um, MIT + + align:start position:0% +whatnot. Um, the other thing, um, MIT + + + align:start position:0% +whatnot. Um, the other thing, um, MIT +has a has an anti-harassment policy. + + align:start position:0% +has a has an anti-harassment policy. + + + align:start position:0% +has a has an anti-harassment policy. +We've also got an anti-harassment + + align:start position:0% +We've also got an anti-harassment + + + align:start position:0% +We've also got an anti-harassment +policy. If anybody's on Twitter these + + align:start position:0% +policy. If anybody's on Twitter these + + + align:start position:0% +policy. If anybody's on Twitter these +days or anybody's engaged in game + + align:start position:0% +days or anybody's engaged in game + + + align:start position:0% +days or anybody's engaged in game +culture these days, it's toxic and it + + align:start position:0% +culture these days, it's toxic and it + + + align:start position:0% +culture these days, it's toxic and it +sucks if it makes me mad. I don't want + + align:start position:0% +sucks if it makes me mad. I don't want + + + align:start position:0% +sucks if it makes me mad. I don't want +to see it in this class, please. Um, so + + align:start position:0% +to see it in this class, please. Um, so + + + align:start position:0% +to see it in this class, please. Um, so +the big the this is on the syllabus. + + align:start position:0% +the big the this is on the syllabus. + + + align:start position:0% +the big the this is on the syllabus. +It's the last page of the syllabus. Um, + + align:start position:0% +It's the last page of the syllabus. Um, + + + align:start position:0% +It's the last page of the syllabus. Um, +basically don't make offensive verbal + + align:start position:0% +basically don't make offensive verbal + + + align:start position:0% +basically don't make offensive verbal +comments or any other kind of comments + + align:start position:0% +comments or any other kind of comments + + + align:start position:0% +comments or any other kind of comments +about all these different things when it + + align:start position:0% +about all these different things when it + + + align:start position:0% +about all these different things when it +comes to gender, identity, sexual + + align:start position:0% +comes to gender, identity, sexual + + + align:start position:0% +comes to gender, identity, sexual +orientation, disability, physical + + align:start position:0% +orientation, disability, physical + + + align:start position:0% +orientation, disability, physical +appearance, body size, race, religion. + + align:start position:0% +appearance, body size, race, religion. + + + align:start position:0% +appearance, body size, race, religion. +Um, just don't be a jerk. Don't be an + + align:start position:0% +Um, just don't be a jerk. Don't be an + + + align:start position:0% +Um, just don't be a jerk. Don't be an +ass. + + align:start position:0% +ass. + + + align:start position:0% +ass. +Um, more importantly though, if you see + + align:start position:0% +Um, more importantly though, if you see + + + align:start position:0% +Um, more importantly though, if you see +it happening, let us know. If you are a + + align:start position:0% +it happening, let us know. If you are a + + + align:start position:0% +it happening, let us know. If you are a +target of this, let us know. There's + + align:start position:0% +target of this, let us know. There's + + + align:start position:0% +target of this, let us know. There's +ways to to get around this. There's ways + + align:start position:0% +ways to to get around this. There's ways + + + align:start position:0% +ways to to get around this. There's ways +to to to report this. There's in the + + align:start position:0% +to to to report this. There's in the + + + align:start position:0% +to to to report this. There's in the +syllabus, it actually lists the website + + align:start position:0% +syllabus, it actually lists the website + + + align:start position:0% +syllabus, it actually lists the website +for the official MIT way to report it if + + align:start position:0% +for the official MIT way to report it if + + + align:start position:0% +for the official MIT way to report it if +you'd like to go that way. If you'd + + align:start position:0% +you'd like to go that way. If you'd + + + align:start position:0% +you'd like to go that way. If you'd +rather not come to either the + + align:start position:0% +rather not come to either the + + + align:start position:0% +rather not come to either the +instructors or your TA and our email + + align:start position:0% +instructors or your TA and our email + + + align:start position:0% +instructors or your TA and our email +address, video + + align:start position:0% +address, video + + + align:start position:0% +address, video +games-bosses.edu, email that. Don't + + align:start position:0% +games-bosses.edu, email that. Don't + + + align:start position:0% +games-bosses.edu, email that. Don't +email us individually. That makes sure + + align:start position:0% +email us individually. That makes sure + + + align:start position:0% +email us individually. That makes sure +that one of us reads it. + + align:start position:0% +that one of us reads it. + + + align:start position:0% +that one of us reads it. +Yes, please. + + align:start position:0% + + + + align:start position:0% + +about anything + + align:start position:0% + + + + align:start position:0% + +right there. + + align:start position:0% +right there. + + + align:start position:0% +right there. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +Yeah. Um we are like team game + + align:start position:0% +Yeah. Um we are like team game + + + align:start position:0% +Yeah. Um we are like team game +development is stressful. Yeah. + + align:start position:0% +development is stressful. Yeah. + + + align:start position:0% +development is stressful. Yeah. +Question. One phrase that I've heard + + align:start position:0% +Question. One phrase that I've heard + + + align:start position:0% +Question. One phrase that I've heard +recently that I + + align:start position:0% +recently that I + + + align:start position:0% +recently that I +love rules down. You have a right to be + + align:start position:0% +love rules down. You have a right to be + + + align:start position:0% +love rules down. You have a right to be +respected. Um the rules that are listed + + align:start position:0% +respected. Um the rules that are listed + + + align:start position:0% +respected. Um the rules that are listed +will be + + align:start position:0% +will be + + + align:start position:0% +will be +papermâch. But in general, be + + align:start position:0% +papermâch. But in general, be + + + align:start position:0% +papermâch. But in general, be +respectful. Yeah, that's really what + + align:start position:0% +respectful. Yeah, that's really what + + + align:start position:0% +respectful. Yeah, that's really what +we're asking for is just be respectful + + align:start position:0% +we're asking for is just be respectful + + + align:start position:0% +we're asking for is just be respectful +for each other. You're going to be + + align:start position:0% +for each other. You're going to be + + + align:start position:0% +for each other. You're going to be +working on large teams. There are going + + align:start position:0% +working on large teams. There are going + + + align:start position:0% +working on large teams. There are going +to be deadlines. It's going to hurt. + + align:start position:0% +to be deadlines. It's going to hurt. + + + align:start position:0% +to be deadlines. It's going to hurt. +It's going to be painful. Things are + + align:start position:0% +It's going to be painful. Things are + + + align:start position:0% +It's going to be painful. Things are +going to slip. Don't let that be the way + + align:start position:0% +going to slip. Don't let that be the way + + + align:start position:0% +going to slip. Don't let that be the way +that you express it. We'll actually give + + align:start position:0% +that you express it. We'll actually give + + + align:start position:0% +that you express it. We'll actually give +you some better tools to express your + + align:start position:0% +you some better tools to express your + + + align:start position:0% +you some better tools to express your +your pain and + + align:start position:0% +your pain and + + + align:start position:0% +your pain and +suffering. Um so the class is called + + align:start position:0% +suffering. Um so the class is called + + + align:start position:0% +suffering. Um so the class is called +creating video games. How do we create + + align:start position:0% +creating video games. How do we create + + + align:start position:0% +creating video games. How do we create +video games? Um, we have a whole bunch + + align:start position:0% +video games? Um, we have a whole bunch + + + align:start position:0% +video games? Um, we have a whole bunch +of people involved in creating video + + align:start position:0% +of people involved in creating video + + + align:start position:0% +of people involved in creating video +games. Was this a slide you were coming + + align:start position:0% +games. Was this a slide you were coming + + + align:start position:0% +games. Was this a slide you were coming +in on or is this This is the slide I was + + align:start position:0% +in on or is this This is the slide I was + + + align:start position:0% +in on or is this This is the slide I was +going to chime in on. Yeah. But you were + + align:start position:0% +going to chime in on. Yeah. But you were + + + align:start position:0% +going to chime in on. Yeah. But you were +chiming so nicely. So, basically, all + + align:start position:0% +chiming so nicely. So, basically, all + + + align:start position:0% +chiming so nicely. So, basically, all +sorts of people are required to make + + align:start position:0% +sorts of people are required to make + + + align:start position:0% +sorts of people are required to make +games. We have all of those people in + + align:start position:0% +games. We have all of those people in + + + align:start position:0% +games. We have all of those people in +the world. Actually, a whole lot of + + align:start position:0% +the world. Actually, a whole lot of + + + align:start position:0% +the world. Actually, a whole lot of +skills are required to make games. Um, + + align:start position:0% +skills are required to make games. Um, + + + align:start position:0% +skills are required to make games. Um, +you should not come in and think, I'm + + align:start position:0% +you should not come in and think, I'm + + + align:start position:0% +you should not come in and think, I'm +gonna be the programmer on this team. + + align:start position:0% +gonna be the programmer on this team. + + + align:start position:0% +gonna be the programmer on this team. +You should not come in and think, I'm + + align:start position:0% +You should not come in and think, I'm + + + align:start position:0% +You should not come in and think, I'm +gonna be the game designer on this team + + align:start position:0% +gonna be the game designer on this team + + + align:start position:0% +gonna be the game designer on this team +or I'm gonna be the artist on this team + + align:start position:0% +or I'm gonna be the artist on this team + + + align:start position:0% +or I'm gonna be the artist on this team +or the sound designer on this team. Um + + align:start position:0% +or the sound designer on this team. Um + + + align:start position:0% +or the sound designer on this team. Um +the teams are small enough even when you + + align:start position:0% +the teams are small enough even when you + + + align:start position:0% +the teams are small enough even when you +hit the eight person team for the large + + align:start position:0% +hit the eight person team for the large + + + align:start position:0% +hit the eight person team for the large +project and the projects are always + + align:start position:0% +project and the projects are always + + + align:start position:0% +project and the projects are always +challenging enough. Even if you think + + align:start position:0% +challenging enough. Even if you think + + + align:start position:0% +challenging enough. Even if you think +you have a short list of things to do, + + align:start position:0% +you have a short list of things to do, + + + align:start position:0% +you have a short list of things to do, +you have a challenging project. That's + + align:start position:0% +you have a challenging project. That's + + + align:start position:0% +you have a challenging project. That's +that's one thing we've noticed every + + align:start position:0% +that's one thing we've noticed every + + + align:start position:0% +that's one thing we've noticed every +single year. Everybody manages to come + + align:start position:0% +single year. Everybody manages to come + + + align:start position:0% +single year. Everybody manages to come +up with a challenging project. Um the + + align:start position:0% +up with a challenging project. Um the + + + align:start position:0% +up with a challenging project. Um the +team's going to need you doing + + align:start position:0% +team's going to need you doing + + + align:start position:0% +team's going to need you doing +everything you can do. And that means + + align:start position:0% +everything you can do. And that means + + + align:start position:0% +everything you can do. And that means +that if you can program, they probably + + align:start position:0% +that if you can program, they probably + + + align:start position:0% +that if you can program, they probably +want you to program. They need + + align:start position:0% +want you to program. They need + + + align:start position:0% +want you to program. They need +programmers to chime up. If you're + + align:start position:0% +programmers to chime up. If you're + + + align:start position:0% +programmers to chime up. If you're +primarily a programmer or you think + + align:start position:0% +primarily a programmer or you think + + + align:start position:0% +primarily a programmer or you think +yourself of, they need you to chime up + + align:start position:0% +yourself of, they need you to chime up + + + align:start position:0% +yourself of, they need you to chime up +on the game design and comment on places + + align:start position:0% +on the game design and comment on places + + + align:start position:0% +on the game design and comment on places +where it will work better. Um, and you + + align:start position:0% +where it will work better. Um, and you + + + align:start position:0% +where it will work better. Um, and you +understand how it will work better + + align:start position:0% +understand how it will work better + + + align:start position:0% +understand how it will work better +because of your understanding of the + + align:start position:0% +because of your understanding of the + + + align:start position:0% +because of your understanding of the +code. If you're the game designer, you + + align:start position:0% +code. If you're the game designer, you + + + align:start position:0% +code. If you're the game designer, you +got to be ready to pitch in and help + + align:start position:0% +got to be ready to pitch in and help + + + align:start position:0% +got to be ready to pitch in and help +make all those things you see in your + + align:start position:0% +make all those things you see in your + + + align:start position:0% +make all those things you see in your +head happen. Whether that's creating + + align:start position:0% +head happen. Whether that's creating + + + align:start position:0% +head happen. Whether that's creating +some some sketch sketched doodled art so + + align:start position:0% +some some sketch sketched doodled art so + + + align:start position:0% +some some sketch sketched doodled art so +your your team can go with the little + + align:start position:0% +your your team can go with the little + + + align:start position:0% +your your team can go with the little +pixel figures or whatever. + + align:start position:0% +pixel figures or whatever. + + + align:start position:0% +pixel figures or whatever. +Um, we don't they're usually these teams + + align:start position:0% +Um, we don't they're usually these teams + + + align:start position:0% +Um, we don't they're usually these teams +aren't big enough to support someone who + + align:start position:0% +aren't big enough to support someone who + + + align:start position:0% +aren't big enough to support someone who +does nothing but draw art. We're not + + align:start position:0% +does nothing but draw art. We're not + + + align:start position:0% +does nothing but draw art. We're not +actually grading you on the beauty of + + align:start position:0% +actually grading you on the beauty of + + + align:start position:0% +actually grading you on the beauty of +your games. I mean, yes, we want good, + + align:start position:0% +your games. I mean, yes, we want good, + + + align:start position:0% +your games. I mean, yes, we want good, +well functioning, rounded games. We want + + align:start position:0% +well functioning, rounded games. We want + + + align:start position:0% +well functioning, rounded games. We want +games that are relatively easy to use, + + align:start position:0% +games that are relatively easy to use, + + + align:start position:0% +games that are relatively easy to use, +but you don't need super beautiful art + + align:start position:0% +but you don't need super beautiful art + + + align:start position:0% +but you don't need super beautiful art +for that. Um, so if what you'd like to + + align:start position:0% +for that. Um, so if what you'd like to + + + align:start position:0% +for that. Um, so if what you'd like to +do is primarily art for the game, think + + align:start position:0% +do is primarily art for the game, think + + + align:start position:0% +do is primarily art for the game, think +about what else you can be contributing + + align:start position:0% +about what else you can be contributing + + + align:start position:0% +about what else you can be contributing +to the game as well, so that your game + + align:start position:0% +to the game as well, so that your game + + + align:start position:0% +to the game as well, so that your game +gets more functionality in it. And let's + + align:start position:0% +gets more functionality in it. And let's + + + align:start position:0% +gets more functionality in it. And let's +see, for community managers, business + + align:start position:0% +see, for community managers, business + + + align:start position:0% +see, for community managers, business +analyst, marketists, the people who are + + align:start position:0% +analyst, marketists, the people who are + + + align:start position:0% +analyst, marketists, the people who are +pitching your game and talking about it, + + align:start position:0% +pitching your game and talking about it, + + + align:start position:0% +pitching your game and talking about it, +don't lean on the person who ends up + + align:start position:0% +don't lean on the person who ends up + + + align:start position:0% +don't lean on the person who ends up +stepping up to organize your team and + + align:start position:0% +stepping up to organize your team and + + + align:start position:0% +stepping up to organize your team and +steps into the producer role, they're + + align:start position:0% +steps into the producer role, they're + + + align:start position:0% +steps into the producer role, they're +already doing an awful lot of job just + + align:start position:0% +already doing an awful lot of job just + + + align:start position:0% +already doing an awful lot of job just +producing. They're going to need your + + align:start position:0% +producing. They're going to need your + + + align:start position:0% +producing. They're going to need your +help figuring out presentations and + + align:start position:0% +help figuring out presentations and + + + align:start position:0% +help figuring out presentations and +talking about your game and doing the + + align:start position:0% +talking about your game and doing the + + + align:start position:0% +talking about your game and doing the +reflection and keeping the team running. + + align:start position:0% +reflection and keeping the team running. + + + align:start position:0% +reflection and keeping the team running. +So, don't think of these as a whole + + align:start position:0% +So, don't think of these as a whole + + + align:start position:0% +So, don't think of these as a whole +bunch of individuals. Think of it as a + + align:start position:0% +bunch of individuals. Think of it as a + + + align:start position:0% +bunch of individuals. Think of it as a +whole bunch of skills, one of which may + + align:start position:0% +whole bunch of skills, one of which may + + + align:start position:0% +whole bunch of skills, one of which may +be your primary, but choose at least two + + align:start position:0% +be your primary, but choose at least two + + + align:start position:0% +be your primary, but choose at least two +or three as your backup. + + align:start position:0% +or three as your backup. + + + align:start position:0% +or three as your backup. +That's my shtick. Cool. And that's + + align:start position:0% +That's my shtick. Cool. And that's + + + align:start position:0% +That's my shtick. Cool. And that's +basically how indie game development is + + align:start position:0% +basically how indie game development is + + + align:start position:0% +basically how indie game development is +run. And when you see a game made by + + align:start position:0% +run. And when you see a game made by + + + align:start position:0% +run. And when you see a game made by +three people, they're doing all of that. + + align:start position:0% +three people, they're doing all of that. + + + align:start position:0% +three people, they're doing all of that. +And so that's basically what we're + + align:start position:0% +And so that's basically what we're + + + align:start position:0% +And so that's basically what we're +expecting with from + + align:start position:0% +expecting with from + + + align:start position:0% +expecting with from +y'all. So what if we're not teaching a + + align:start position:0% +y'all. So what if we're not teaching a + + + align:start position:0% +y'all. So what if we're not teaching a +lot of those skills, we're the main + + align:start position:0% +lot of those skills, we're the main + + + align:start position:0% +lot of those skills, we're the main +skills that we are teaching in this + + align:start position:0% +skills that we are teaching in this + + + align:start position:0% +skills that we are teaching in this +class is giving you hands-on experience + + align:start position:0% +class is giving you hands-on experience + + + align:start position:0% +class is giving you hands-on experience +working on complex projects with large + + align:start position:0% +working on complex projects with large + + + align:start position:0% +working on complex projects with large +teams. What does that mean? Is basically + + align:start position:0% +teams. What does that mean? Is basically + + + align:start position:0% +teams. What does that mean? Is basically +project management, team management, and + + align:start position:0% +project management, team management, and + + + align:start position:0% +project management, team management, and +communication skills. um you're coming + + align:start position:0% +communication skills. um you're coming + + + align:start position:0% +communication skills. um you're coming +to us through your prerequisites with + + align:start position:0% +to us through your prerequisites with + + + align:start position:0% +to us through your prerequisites with +some design skills. You're coming to us + + align:start position:0% +some design skills. You're coming to us + + + align:start position:0% +some design skills. You're coming to us +with some programming skills. You have + + align:start position:0% +with some programming skills. You have + + + align:start position:0% +with some programming skills. You have +support for some of the game engines you + + align:start position:0% +support for some of the game engines you + + + align:start position:0% +support for some of the game engines you +haven't seen before, but like any other + + align:start position:0% +haven't seen before, but like any other + + + align:start position:0% +haven't seen before, but like any other +um engineering course at MIT, you pick + + align:start position:0% +um engineering course at MIT, you pick + + + align:start position:0% +um engineering course at MIT, you pick +up a tool, you learn how to use the tool + + align:start position:0% +up a tool, you learn how to use the tool + + + align:start position:0% +up a tool, you learn how to use the tool +in course in the course if you need to + + align:start position:0% +in course in the course if you need to + + + align:start position:0% +in course in the course if you need to +use it. So the tools that we've chosen + + align:start position:0% +use it. So the tools that we've chosen + + + align:start position:0% +use it. So the tools that we've chosen +should be should be short enough that + + align:start position:0% +should be should be short enough that + + + align:start position:0% +should be should be short enough that +you can be a be able to pick them up + + align:start position:0% +you can be a be able to pick them up + + + align:start position:0% +you can be a be able to pick them up +pretty quickly. And that's actually + + align:start position:0% +pretty quickly. And that's actually + + + align:start position:0% +pretty quickly. And that's actually +we're going to go into that today as + + align:start position:0% +we're going to go into that today as + + + align:start position:0% +we're going to go into that today as +well. Um, but the remainder of the + + align:start position:0% +well. Um, but the remainder of the + + + align:start position:0% +well. Um, but the remainder of the +course, particularly projects two and + + align:start position:0% +course, particularly projects two and + + + align:start position:0% +course, particularly projects two and +projects three, are going to be focused + + align:start position:0% +projects three, are going to be focused + + + align:start position:0% +projects three, are going to be focused +on communication. Um, if you're in a + + align:start position:0% +on communication. Um, if you're in a + + + align:start position:0% +on communication. Um, if you're in a +large pro, if you're on a large team, + + align:start position:0% +large pro, if you're on a large team, + + + align:start position:0% +large pro, if you're on a large team, +how do you talk to each other? How do + + align:start position:0% +how do you talk to each other? How do + + + align:start position:0% +how do you talk to each other? How do +you communicate with each other? Is it + + align:start position:0% +you communicate with each other? Is it + + + align:start position:0% +you communicate with each other? Is it +going to be through email, instant + + align:start position:0% +going to be through email, instant + + + align:start position:0% +going to be through email, instant +message, chat, um, post-it notes, um, + + align:start position:0% +message, chat, um, post-it notes, um, + + + align:start position:0% +message, chat, um, post-it notes, um, +mash notes, hate notes, karaoke, um, + + align:start position:0% +mash notes, hate notes, karaoke, um, + + + align:start position:0% +mash notes, hate notes, karaoke, um, +bottlenecks are going to form, uh, in + + align:start position:0% +bottlenecks are going to form, uh, in + + + align:start position:0% +bottlenecks are going to form, uh, in +your in your work process. you're going + + align:start position:0% +your in your work process. you're going + + + align:start position:0% +your in your work process. you're going +to find out that oh all the assets are + + align:start position:0% +to find out that oh all the assets are + + + align:start position:0% +to find out that oh all the assets are +going to one person and they're sick + + align:start position:0% +going to one person and they're sick + + + align:start position:0% +going to one person and they're sick +today. + + align:start position:0% +today. + + + align:start position:0% +today. +Um quality of your code and assets are + + align:start position:0% +Um quality of your code and assets are + + + align:start position:0% +Um quality of your code and assets are +going to quickly nose dive if you don't + + align:start position:0% +going to quickly nose dive if you don't + + + align:start position:0% +going to quickly nose dive if you don't +have a plan. Yeah, this is another one + + align:start position:0% +have a plan. Yeah, this is another one + + + align:start position:0% +have a plan. Yeah, this is another one +of those. Don't have don't assume that + + align:start position:0% +of those. Don't have don't assume that + + + align:start position:0% +of those. Don't have don't assume that +one person on your team is going to do + + align:start position:0% +one person on your team is going to do + + + align:start position:0% +one person on your team is going to do +all the art or all the sound and that's + + align:start position:0% +all the art or all the sound and that's + + + align:start position:0% +all the art or all the sound and that's +all they're going to do because if they + + align:start position:0% +all they're going to do because if they + + + align:start position:0% +all they're going to do because if they +get hit by the flu truck as frequently + + align:start position:0% +get hit by the flu truck as frequently + + + align:start position:0% +get hit by the flu truck as frequently +happens around here, you'll discover + + align:start position:0% +happens around here, you'll discover + + + align:start position:0% +happens around here, you'll discover +you've got nothing to put in the + + align:start position:0% +you've got nothing to put in the + + + align:start position:0% +you've got nothing to put in the +beautiful game that you've made. + + align:start position:0% + + + + align:start position:0% + +So to get around that, we're going to + + align:start position:0% +So to get around that, we're going to + + + align:start position:0% +So to get around that, we're going to +introduce to you tools and methods + + align:start position:0% +introduce to you tools and methods + + + align:start position:0% +introduce to you tools and methods +through the course that are going to + + align:start position:0% +through the course that are going to + + + align:start position:0% +through the course that are going to +help you get through these problems. Um + + align:start position:0% +help you get through these problems. Um + + + align:start position:0% +help you get through these problems. Um +how to do code workflow, how to do asset + + align:start position:0% +how to do code workflow, how to do asset + + + align:start position:0% +how to do code workflow, how to do asset +workflow. We'll talk about that a little + + align:start position:0% +workflow. We'll talk about that a little + + + align:start position:0% +workflow. We'll talk about that a little +bit. Um that's actually the the first + + align:start position:0% +bit. Um that's actually the the first + + + align:start position:0% +bit. Um that's actually the the first +assignment. Um, we'll talk about code + + align:start position:0% +assignment. Um, we'll talk about code + + + align:start position:0% +assignment. Um, we'll talk about code +review. Um, we're not necessarily + + align:start position:0% +review. Um, we're not necessarily + + + align:start position:0% +review. Um, we're not necessarily +teaching a lot of this. We'll be talking + + align:start position:0% +teaching a lot of this. We'll be talking + + + align:start position:0% +teaching a lot of this. We'll be talking +about a lot of this. I know some of you + + align:start position:0% +about a lot of this. I know some of you + + + align:start position:0% +about a lot of this. I know some of you +have done some of this in other + + align:start position:0% +have done some of this in other + + + align:start position:0% +have done some of this in other +experiences. We actually want you to + + align:start position:0% +experiences. We actually want you to + + + align:start position:0% +experiences. We actually want you to +help other people out in the course. + + align:start position:0% +help other people out in the course. + + + align:start position:0% +help other people out in the course. +Talk about your previous experiences + + align:start position:0% +Talk about your previous experiences + + + align:start position:0% +Talk about your previous experiences +working on a project. If you've done an + + align:start position:0% +working on a project. If you've done an + + + align:start position:0% +working on a project. If you've done an +internship before, if you made an app + + align:start position:0% +internship before, if you made an app + + + align:start position:0% +internship before, if you made an app +for a company before everybody has apps + + align:start position:0% +for a company before everybody has apps + + + align:start position:0% +for a company before everybody has apps +these days, um, you've probably run into + + align:start position:0% +these days, um, you've probably run into + + + align:start position:0% +these days, um, you've probably run into +some of this. So, we want to hear about + + align:start position:0% +some of this. So, we want to hear about + + + align:start position:0% +some of this. So, we want to hear about +your experiences, too. Um, we're going + + align:start position:0% +your experiences, too. Um, we're going + + + align:start position:0% +your experiences, too. Um, we're going +to talk to you a lot about product + + align:start position:0% +to talk to you a lot about product + + + align:start position:0% +to talk to you a lot about product +backlogs and tasks lists, paper, using + + align:start position:0% +backlogs and tasks lists, paper, using + + + align:start position:0% +backlogs and tasks lists, paper, using +paper and spreadsheets to to tell each + + align:start position:0% +paper and spreadsheets to to tell each + + + align:start position:0% +paper and spreadsheets to to tell each +other what you've been working on and + + align:start position:0% +other what you've been working on and + + + align:start position:0% +other what you've been working on and +how you're going to work on it. Um, I'll + + align:start position:0% +how you're going to work on it. Um, I'll + + + align:start position:0% +how you're going to work on it. Um, I'll +be talking a lot about retrospectives, + + align:start position:0% +be talking a lot about retrospectives, + + + align:start position:0% +be talking a lot about retrospectives, +about how at the end of a project you + + align:start position:0% +about how at the end of a project you + + + align:start position:0% +about how at the end of a project you +can talk about the the what you've just + + align:start position:0% +can talk about the the what you've just + + + align:start position:0% +can talk about the the what you've just +done and how you can do it quickly. Um, + + align:start position:0% +done and how you can do it quickly. Um, + + + align:start position:0% +done and how you can do it quickly. Um, +but ultimately we can give you all the + + align:start position:0% +but ultimately we can give you all the + + + align:start position:0% +but ultimately we can give you all the +tool, all the method. The best way to + + align:start position:0% +tool, all the method. The best way to + + + align:start position:0% +tool, all the method. The best way to +learn all the to know all this is really + + align:start position:0% +learn all the to know all this is really + + + align:start position:0% +learn all the to know all this is really +just through prior experience. So, this + + align:start position:0% +just through prior experience. So, this + + + align:start position:0% +just through prior experience. So, this +class is going to be that prior + + align:start position:0% +class is going to be that prior + + + align:start position:0% +class is going to be that prior +experience for you when you go to your + + align:start position:0% +experience for you when you go to your + + + align:start position:0% +experience for you when you go to your +next your next challenge. um either + + align:start position:0% +next your next challenge. um either + + + align:start position:0% +next your next challenge. um either +working at a working in the industry, + + align:start position:0% +working at a working in the industry, + + + align:start position:0% +working at a working in the industry, +working doing any kind of software + + align:start position:0% +working doing any kind of software + + + align:start position:0% +working doing any kind of software +engineering or going to another + + align:start position:0% +engineering or going to another + + + align:start position:0% +engineering or going to another +class. So again the cheat sheet work + + align:start position:0% +class. So again the cheat sheet work + + + align:start position:0% +class. So again the cheat sheet work +face to face test often prioritize + + align:start position:0% +face to face test often prioritize + + + align:start position:0% +face to face test often prioritize +integrate and cut features early sleep + + align:start position:0% +integrate and cut features early sleep + + + align:start position:0% +integrate and cut features early sleep +avoid 3D don't do networking and use + + align:start position:0% +avoid 3D don't do networking and use + + + align:start position:0% +avoid 3D don't do networking and use +version control + + align:start position:0% +version control + + + align:start position:0% +version control +please. And this is where the cut I have + + align:start position:0% +please. And this is where the cut I have + + + align:start position:0% +please. And this is where the cut I have +from the last three years of this course + + align:start position:0% +from the last three years of this course + + + align:start position:0% +from the last three years of this course +and the final presentations from pretty + + align:start position:0% +and the final presentations from pretty + + + align:start position:0% +and the final presentations from pretty +much every group that's given a final + + align:start position:0% +much every group that's given a final + + + align:start position:0% +much every group that's given a final +presentation for their final project in + + align:start position:0% +presentation for their final project in + + + align:start position:0% +presentation for their final project in +which they look at us sheeply sheepishly + + align:start position:0% +which they look at us sheeply sheepishly + + + align:start position:0% +which they look at us sheeply sheepishly +and said you said we should test early + + align:start position:0% +and said you said we should test early + + + align:start position:0% +and said you said we should test early +and you know what we really should have + + align:start position:0% +and you know what we really should have + + + align:start position:0% +and you know what we really should have +tested earlier and I can't actually be + + align:start position:0% +tested earlier and I can't actually be + + + align:start position:0% +tested earlier and I can't actually be +15 different MIT students who have taken + + align:start position:0% +15 different MIT students who have taken + + + align:start position:0% +15 different MIT students who have taken +this course saying this sheepishly up on + + align:start position:0% +this course saying this sheepishly up on + + + align:start position:0% +this course saying this sheepishly up on +the screen but I've heard it from all of + + align:start position:0% +the screen but I've heard it from all of + + + align:start position:0% +the screen but I've heard it from all of +them pretty much every single group. So, + + align:start position:0% +them pretty much every single group. So, + + + align:start position:0% +them pretty much every single group. So, +I'm gonna give you guys the the early + + align:start position:0% +I'm gonna give you guys the the early + + + align:start position:0% +I'm gonna give you guys the the early +the really early heads up warning. Test + + align:start position:0% +the really early heads up warning. Test + + + align:start position:0% +the really early heads up warning. Test +earlier. When we say it, we mean it. I'd + + align:start position:0% +earlier. When we say it, we mean it. I'd + + + align:start position:0% +earlier. When we say it, we mean it. I'd +like to introduce Pablo Suarez. Um he + + align:start position:0% +like to introduce Pablo Suarez. Um he + + + align:start position:0% +like to introduce Pablo Suarez. Um he +and his group will be our client for + + align:start position:0% +and his group will be our client for + + + align:start position:0% +and his group will be our client for +project four. Um so, we're asking him to + + align:start position:0% +project four. Um so, we're asking him to + + + align:start position:0% +project four. Um so, we're asking him to +give a an introduction of the kind of + + align:start position:0% +give a an introduction of the kind of + + + align:start position:0% +give a an introduction of the kind of +work that he does so you can kind of get + + align:start position:0% +work that he does so you can kind of get + + + align:start position:0% +work that he does so you can kind of get +the feeling for what the kind of work + + align:start position:0% +the feeling for what the kind of work + + + align:start position:0% +the feeling for what the kind of work +that we're going to be doing in class. + + align:start position:0% +that we're going to be doing in class. + + + align:start position:0% +that we're going to be doing in class. +The first three projects are going to + + align:start position:0% +The first three projects are going to + + + align:start position:0% +The first three projects are going to +build slowly towards that final project + + align:start position:0% +build slowly towards that final project + + + align:start position:0% +build slowly towards that final project +in the in the theme and the constraints + + align:start position:0% +in the in the theme and the constraints + + + align:start position:0% +in the in the theme and the constraints +of those games. And then that fourth + + align:start position:0% +of those games. And then that fourth + + + align:start position:0% +of those games. And then that fourth +project, um, Candace will come back in + + align:start position:0% +project, um, Candace will come back in + + + align:start position:0% +project, um, Candace will come back in +again and tell us more detail about what + + align:start position:0% +again and tell us more detail about what + + + align:start position:0% +again and tell us more detail about what +they're really looking for, what what + + align:start position:0% +they're really looking for, what what + + + align:start position:0% +they're really looking for, what what +kind of games are really looking at for + + align:start position:0% +kind of games are really looking at for + + + align:start position:0% +kind of games are really looking at for +from us. So, take Thank you. Thanks, + + align:start position:0% +from us. So, take Thank you. Thanks, + + + align:start position:0% +from us. So, take Thank you. Thanks, +Rick. Thanks, uh, Game Lab team. Very + + align:start position:0% +Rick. Thanks, uh, Game Lab team. Very + + + align:start position:0% +Rick. Thanks, uh, Game Lab team. Very +grateful for this. And you, I am + + align:start position:0% +grateful for this. And you, I am + + + align:start position:0% +grateful for this. And you, I am +grateful to you even though you don't + + align:start position:0% +grateful to you even though you don't + + + align:start position:0% +grateful to you even though you don't +have much of a choice that I show up and + + align:start position:0% +have much of a choice that I show up and + + + align:start position:0% +have much of a choice that I show up and +you have to suffer through me. Uh, my + + align:start position:0% +you have to suffer through me. Uh, my + + + align:start position:0% +you have to suffer through me. Uh, my +name is Pablo. Pablo Suarez. My strange + + align:start position:0% +name is Pablo. Pablo Suarez. My strange + + + align:start position:0% +name is Pablo. Pablo Suarez. My strange +accent comes from Argentina. I live in + + align:start position:0% +accent comes from Argentina. I live in + + + align:start position:0% +accent comes from Argentina. I live in +the Boston area where a fraction of my + + align:start position:0% +the Boston area where a fraction of my + + + align:start position:0% +the Boston area where a fraction of my +time I'm a researcher. I used to be a + + align:start position:0% +time I'm a researcher. I used to be a + + + align:start position:0% +time I'm a researcher. I used to be a +research affiliate with MIT. I just came + + align:start position:0% +research affiliate with MIT. I just came + + + align:start position:0% +research affiliate with MIT. I just came +from the Lincoln Labs where I'm + + align:start position:0% +from the Lincoln Labs where I'm + + + align:start position:0% +from the Lincoln Labs where I'm +collaborating with MIT folks there as + + align:start position:0% +collaborating with MIT folks there as + + + align:start position:0% +collaborating with MIT folks there as +well. But most of my time I work with a + + align:start position:0% +well. But most of my time I work with a + + + align:start position:0% +well. But most of my time I work with a +humanitarian team, the Red Cross Red + + align:start position:0% +humanitarian team, the Red Cross Red + + + align:start position:0% +humanitarian team, the Red Cross Red +Crescent Climate Center. It's like a + + align:start position:0% +Crescent Climate Center. It's like a + + + align:start position:0% +Crescent Climate Center. It's like a +think tank within the humanitarian + + align:start position:0% +think tank within the humanitarian + + + align:start position:0% +think tank within the humanitarian +sector. It's based in the Netherlands. + + align:start position:0% +sector. It's based in the Netherlands. + + + align:start position:0% +sector. It's based in the Netherlands. +We cover the planet, 187 countries. I am + + align:start position:0% +We cover the planet, 187 countries. I am + + + align:start position:0% +We cover the planet, 187 countries. I am +in charge of research, in charge of + + align:start position:0% +in charge of research, in charge of + + + align:start position:0% +in charge of research, in charge of +innovation, mostly in charge of Africa. + + align:start position:0% +innovation, mostly in charge of Africa. + + + align:start position:0% +innovation, mostly in charge of Africa. +And unfortunately for the world, we have + + align:start position:0% +And unfortunately for the world, we have + + + align:start position:0% +And unfortunately for the world, we have +way way too much work. Um the workload + + align:start position:0% +way way too much work. Um the workload + + + align:start position:0% +way way too much work. Um the workload +is so ridiculously huge that in my + + align:start position:0% +is so ridiculously huge that in my + + + align:start position:0% +is so ridiculously huge that in my +opinion, especially coming from science + + align:start position:0% +opinion, especially coming from science + + + align:start position:0% +opinion, especially coming from science +and technology, we need to change the + + align:start position:0% +and technology, we need to change the + + + align:start position:0% +and technology, we need to change the +way we think about humanitarian work. + + align:start position:0% +way we think about humanitarian work. + + + align:start position:0% +way we think about humanitarian work. +And if it is about changing how we + + align:start position:0% +And if it is about changing how we + + + align:start position:0% +And if it is about changing how we +think, traditional ways are not working + + align:start position:0% +think, traditional ways are not working + + + align:start position:0% +think, traditional ways are not working +too well. And that's why I'm here. Uh I + + align:start position:0% +too well. And that's why I'm here. Uh I + + + align:start position:0% +too well. And that's why I'm here. Uh I +love this slide. Uh we have a comfort + + align:start position:0% +love this slide. Uh we have a comfort + + + align:start position:0% +love this slide. Uh we have a comfort +zone which is doing things the way we've + + align:start position:0% +zone which is doing things the way we've + + + align:start position:0% +zone which is doing things the way we've +been doing them. Someone's hungry, go + + align:start position:0% +been doing them. Someone's hungry, go + + + align:start position:0% +been doing them. Someone's hungry, go +give food. Someone's homeless, go give + + align:start position:0% +give food. Someone's homeless, go give + + + align:start position:0% +give food. Someone's homeless, go give +shelter. Someone's sick, help them heal. + + align:start position:0% +shelter. Someone's sick, help them heal. + + + align:start position:0% +shelter. Someone's sick, help them heal. +But we no longer have the money, the the + + align:start position:0% +But we no longer have the money, the the + + + align:start position:0% +But we no longer have the money, the the +brain power, the equipment to deal with + + align:start position:0% +brain power, the equipment to deal with + + + align:start position:0% +brain power, the equipment to deal with +all that's happening. Too much is + + align:start position:0% +all that's happening. Too much is + + + align:start position:0% +all that's happening. Too much is +happening. The climate is changing. uh + + align:start position:0% +happening. The climate is changing. uh + + + align:start position:0% +happening. The climate is changing. uh +environmental degradation, urbanization, + + align:start position:0% +environmental degradation, urbanization, + + + align:start position:0% +environmental degradation, urbanization, +political instability, weird diseases, + + align:start position:0% +political instability, weird diseases, + + + align:start position:0% +political instability, weird diseases, +you name it. How can we learn more about + + align:start position:0% +you name it. How can we learn more about + + + align:start position:0% +you name it. How can we learn more about +what we can + + align:start position:0% +what we can + + + align:start position:0% +what we can +do? We need as humanitarian workers to + + align:start position:0% +do? We need as humanitarian workers to + + + align:start position:0% +do? We need as humanitarian workers to +get into a new place where we can do + + align:start position:0% +get into a new place where we can do + + + align:start position:0% +get into a new place where we can do +more with what we have and that place is + + align:start position:0% +more with what we have and that place is + + + align:start position:0% +more with what we have and that place is +outside our comfort zone. Now, magic can + + align:start position:0% +outside our comfort zone. Now, magic can + + + align:start position:0% +outside our comfort zone. Now, magic can +happen, but very often we step out of + + align:start position:0% +happen, but very often we step out of + + + align:start position:0% +happen, but very often we step out of +our comfort zone and we fall into the + + align:start position:0% +our comfort zone and we fall into the + + + align:start position:0% +our comfort zone and we fall into the +abyss. It's not easy to find the right + + align:start position:0% +abyss. It's not easy to find the right + + + align:start position:0% +abyss. It's not easy to find the right +place. This is a risky endeavor for me. + + align:start position:0% +place. This is a risky endeavor for me. + + + align:start position:0% +place. This is a risky endeavor for me. +I'm here hoping that you guys will + + align:start position:0% +I'm here hoping that you guys will + + + align:start position:0% +I'm here hoping that you guys will +accomplish one of two things. One is + + align:start position:0% +accomplish one of two things. One is + + + align:start position:0% +accomplish one of two things. One is +maybe you come up with a game concept + + align:start position:0% +maybe you come up with a game concept + + + align:start position:0% +maybe you come up with a game concept +that has a life after the end of your + + align:start position:0% +that has a life after the end of your + + + align:start position:0% +that has a life after the end of your +course. You get your credit, you + + align:start position:0% +course. You get your credit, you + + + align:start position:0% +course. You get your credit, you +graduate, and the Red Cross or others + + align:start position:0% +graduate, and the Red Cross or others + + + align:start position:0% +graduate, and the Red Cross or others +can play a game that helps someone + + align:start position:0% +can play a game that helps someone + + + align:start position:0% +can play a game that helps someone +understand something, helps someone do + + align:start position:0% +understand something, helps someone do + + + align:start position:0% +understand something, helps someone do +something, helps someone collect data + + align:start position:0% +something, helps someone collect data + + + align:start position:0% +something, helps someone collect data +about something. And we'll talk more + + align:start position:0% +about something. And we'll talk more + + + align:start position:0% +about something. And we'll talk more +about what are those things that we want + + align:start position:0% +about what are those things that we want + + + align:start position:0% +about what are those things that we want +when we get to H project 4. The other + + align:start position:0% +when we get to H project 4. The other + + + align:start position:0% +when we get to H project 4. The other +one is maybe we can lure you even if one + + align:start position:0% +one is maybe we can lure you even if one + + + align:start position:0% +one is maybe we can lure you even if one +of you even if one of the uh game lab + + align:start position:0% +of you even if one of the uh game lab + + + align:start position:0% +of you even if one of the uh game lab +team to consider humanitarian work as + + align:start position:0% +team to consider humanitarian work as + + + align:start position:0% +team to consider humanitarian work as +part of what you may be doing in your + + align:start position:0% +part of what you may be doing in your + + + align:start position:0% +part of what you may be doing in your +future life either as your job or as + + align:start position:0% +future life either as your job or as + + + align:start position:0% +future life either as your job or as +your hobby. It's great fun. It's great + + align:start position:0% +your hobby. It's great fun. It's great + + + align:start position:0% +your hobby. It's great fun. It's great +intellectual challenge. the head of my + + align:start position:0% +intellectual challenge. the head of my + + + align:start position:0% +intellectual challenge. the head of my +team, Martin Vanal, he's an + + align:start position:0% +team, Martin Vanal, he's an + + + align:start position:0% +team, Martin Vanal, he's an +astrophysicist by training. Okay? So, + + align:start position:0% +astrophysicist by training. Okay? So, + + + align:start position:0% +astrophysicist by training. Okay? So, +you don't have much uh uh awareness of + + align:start position:0% +you don't have much uh uh awareness of + + + align:start position:0% +you don't have much uh uh awareness of +the extent to which humanitarian workers + + align:start position:0% +the extent to which humanitarian workers + + + align:start position:0% +the extent to which humanitarian workers +can come from unusual places. And we + + align:start position:0% +can come from unusual places. And we + + + align:start position:0% +can come from unusual places. And we +hope that MIT stops being an unusual + + align:start position:0% +hope that MIT stops being an unusual + + + align:start position:0% +hope that MIT stops being an unusual +place for humanitarian stuff. So, let me + + align:start position:0% +place for humanitarian stuff. So, let me + + + align:start position:0% +place for humanitarian stuff. So, let me +illustrate the kinds of challenges we + + align:start position:0% +illustrate the kinds of challenges we + + + align:start position:0% +illustrate the kinds of challenges we +get. This is an actual facts that + + align:start position:0% +get. This is an actual facts that + + + align:start position:0% +get. This is an actual facts that +actually arrived in May 2008 to the + + align:start position:0% +actually arrived in May 2008 to the + + + align:start position:0% +actually arrived in May 2008 to the +office of my colleague Ysef Shelush who + + align:start position:0% +office of my colleague Ysef Shelush who + + + align:start position:0% +office of my colleague Ysef Shelush who +at the time was based in DAR + + align:start position:0% +at the time was based in DAR + + + align:start position:0% +at the time was based in DAR +uh in charge. Let me see if this + + align:start position:0% +uh in charge. Let me see if this + + + align:start position:0% +uh in charge. Let me see if this +works. Okay, for those of you who know + + align:start position:0% +works. Okay, for those of you who know + + + align:start position:0% +works. Okay, for those of you who know +Dakar, it's near those green + + align:start position:0% +Dakar, it's near those green + + + align:start position:0% +Dakar, it's near those green +pixels. That's where at the time was the + + align:start position:0% +pixels. That's where at the time was the + + + align:start position:0% +pixels. That's where at the time was the +regional office for West and Central + + align:start position:0% +regional office for West and Central + + + align:start position:0% +regional office for West and Central +Africa. 28 countries going from + + align:start position:0% +Africa. 28 countries going from + + + align:start position:0% +Africa. 28 countries going from +Moritania where there has been a + + align:start position:0% +Moritania where there has been a + + + align:start position:0% +Moritania where there has been a +military coup and there was bloodshed in + + align:start position:0% +military coup and there was bloodshed in + + + align:start position:0% +military coup and there was bloodshed in +the streets and Red Cross volunteers + + align:start position:0% +the streets and Red Cross volunteers + + + align:start position:0% +the streets and Red Cross volunteers +needed to learn first aid to prevent + + align:start position:0% +needed to learn first aid to prevent + + + align:start position:0% +needed to learn first aid to prevent +someone bleeding to death all the way to + + align:start position:0% +someone bleeding to death all the way to + + + align:start position:0% +someone bleeding to death all the way to +Congo Brazavville in the southernmost + + align:start position:0% +Congo Brazavville in the southernmost + + + align:start position:0% +Congo Brazavville in the southernmost +part of his area where there was + + align:start position:0% +part of his area where there was + + + align:start position:0% +part of his area where there was +flooding urban flooding and as Red Cross + + align:start position:0% +flooding urban flooding and as Red Cross + + + align:start position:0% +flooding urban flooding and as Red Cross +we don't fully know how to operate in + + align:start position:0% +we don't fully know how to operate in + + + align:start position:0% +we don't fully know how to operate in +rapidly changing urban contexts we're + + align:start position:0% +rapidly changing urban contexts we're + + + align:start position:0% +rapidly changing urban contexts we're +used to a planet where poor people + + align:start position:0% +used to a planet where poor people + + + align:start position:0% +used to a planet where poor people +suffering people were either in conflict + + align:start position:0% +suffering people were either in conflict + + + align:start position:0% +suffering people were either in conflict +or in rural areas and therefore people + + align:start position:0% +or in rural areas and therefore people + + + align:start position:0% +or in rural areas and therefore people +going to Chad needing shelter aid all + + align:start position:0% +going to Chad needing shelter aid all + + + align:start position:0% +going to Chad needing shelter aid all +sorts of things. Yousef has to deal with + + align:start position:0% +sorts of things. Yousef has to deal with + + + align:start position:0% +sorts of things. Yousef has to deal with +those three and everything in between. + + align:start position:0% +those three and everything in between. + + + align:start position:0% +those three and everything in between. +Chronic food insecurity, Burkina, fast, + + align:start position:0% +Chronic food insecurity, Burkina, fast, + + + align:start position:0% +Chronic food insecurity, Burkina, fast, +you name it. Insufficient training for + + align:start position:0% +you name it. Insufficient training for + + + align:start position:0% +you name it. Insufficient training for +this stuff and he gets this + + align:start position:0% +this stuff and he gets this + + + align:start position:0% +this stuff and he gets this +facts. Now I want you to think you're a + + align:start position:0% +facts. Now I want you to think you're a + + + align:start position:0% +facts. Now I want you to think you're a +decision maker. + + align:start position:0% +decision maker. + + + align:start position:0% +decision maker. +you're someone who has to make decisions + + align:start position:0% +you're someone who has to make decisions + + + align:start position:0% +you're someone who has to make decisions +and gets these facts. It was issued in + + align:start position:0% +and gets these facts. It was issued in + + + align:start position:0% +and gets these facts. It was issued in +May referring to the three coming + + align:start position:0% +May referring to the three coming + + + align:start position:0% +May referring to the three coming +months, June, July, August. And it says + + align:start position:0% +months, June, July, August. And it says + + + align:start position:0% +months, June, July, August. And it says +if we define an + + align:start position:0% +if we define an + + + align:start position:0% +if we define an +extreme precipitation event, extreme + + align:start position:0% +extreme precipitation event, extreme + + + align:start position:0% +extreme precipitation event, extreme +rainfall as being in the top 15% of the + + align:start position:0% +rainfall as being in the top 15% of the + + + align:start position:0% +rainfall as being in the top 15% of the +historical record, then this year, there + + align:start position:0% +historical record, then this year, there + + + align:start position:0% +historical record, then this year, there +was a lot of text. I won't bother you + + align:start position:0% +was a lot of text. I won't bother you + + + align:start position:0% +was a lot of text. I won't bother you +with that. this year because of sea + + align:start position:0% +with that. this year because of sea + + + align:start position:0% +with that. this year because of sea +surface temperature anomalies and other + + align:start position:0% +surface temperature anomalies and other + + + align:start position:0% +surface temperature anomalies and other +things that maybe you know if you're an + + align:start position:0% +things that maybe you know if you're an + + + align:start position:0% +things that maybe you know if you're an +MIT student but it's not what we're used + + align:start position:0% +MIT student but it's not what we're used + + + align:start position:0% +MIT student but it's not what we're used +to this year because of that stuff the + + align:start position:0% +to this year because of that stuff the + + + align:start position:0% +to this year because of that stuff the +probability of extreme range is enhanced + + align:start position:0% +probability of extreme range is enhanced + + + align:start position:0% +probability of extreme range is enhanced +from 15% to between 40 and 50%. + + align:start position:0% +from 15% to between 40 and 50%. + + + align:start position:0% +from 15% to between 40 and 50%. +So this fact is in the office and Yousef + + align:start position:0% +So this fact is in the office and Yousef + + + align:start position:0% +So this fact is in the office and Yousef +looks at it and what does he do? What do + + align:start position:0% +looks at it and what does he do? What do + + + align:start position:0% +looks at it and what does he do? What do +you think he does? What do you think the + + align:start position:0% +you think he does? What do you think the + + + align:start position:0% +you think he does? What do you think the +the humanitarian sector does when we get + + align:start position:0% +the humanitarian sector does when we get + + + align:start position:0% +the humanitarian sector does when we get +information? First of all, to understand + + align:start position:0% +information? First of all, to understand + + + align:start position:0% +information? First of all, to understand +it fully, you need to stop doing + + align:start position:0% +it fully, you need to stop doing + + + align:start position:0% +it fully, you need to stop doing +everything else you're doing. You have + + align:start position:0% +everything else you're doing. You have + + + align:start position:0% +everything else you're doing. You have +to not answer an email. You have to not + + align:start position:0% +to not answer an email. You have to not + + + align:start position:0% +to not answer an email. You have to not +sign the check for the fuel for the + + align:start position:0% +sign the check for the fuel for the + + + align:start position:0% +sign the check for the fuel for the +driver for delivering the something + + align:start position:0% +driver for delivering the something + + + align:start position:0% +driver for delivering the something +rather. And once you start thinking + + align:start position:0% +rather. And once you start thinking + + + align:start position:0% +rather. And once you start thinking +about it, what do I do with a place with + + align:start position:0% +about it, what do I do with a place with + + + align:start position:0% +about it, what do I do with a place with +a green pixel? Do I send uh I don't know + + align:start position:0% +a green pixel? Do I send uh I don't know + + + align:start position:0% +a green pixel? Do I send uh I don't know +one tent, a thousand tents? Where do I + + align:start position:0% +one tent, a thousand tents? Where do I + + + align:start position:0% +one tent, a thousand tents? Where do I +send them? Who to do what? What are the + + align:start position:0% +send them? Who to do what? What are the + + + align:start position:0% +send them? Who to do what? What are the +chances? When will it + + align:start position:0% +chances? When will it + + + align:start position:0% +chances? When will it +happen? So my job is to help the Red + + align:start position:0% +happen? So my job is to help the Red + + + align:start position:0% +happen? So my job is to help the Red +Cross family and the humanitarian sector + + align:start position:0% +Cross family and the humanitarian sector + + + align:start position:0% +Cross family and the humanitarian sector +at large to understand science that can + + align:start position:0% +at large to understand science that can + + + align:start position:0% +at large to understand science that can +help us make smarter decisions. + + align:start position:0% +help us make smarter decisions. + + + align:start position:0% +help us make smarter decisions. +Now if you want to + + align:start position:0% +Now if you want to + + + align:start position:0% +Now if you want to +represent to model with the experience + + align:start position:0% +represent to model with the experience + + + align:start position:0% +represent to model with the experience +of forecast this is how it normally + + align:start position:0% +of forecast this is how it normally + + + align:start position:0% +of forecast this is how it normally +works. There's information that + + align:start position:0% +works. There's information that + + + align:start position:0% +works. There's information that +allegedly can support action that is + + align:start position:0% +allegedly can support action that is + + + align:start position:0% +allegedly can support action that is +communicated with an audience in a + + align:start position:0% +communicated with an audience in a + + + align:start position:0% +communicated with an audience in a +passive mode like a fax or an email or a + + align:start position:0% +passive mode like a fax or an email or a + + + align:start position:0% +passive mode like a fax or an email or a +TV or radio announcement and then you + + align:start position:0% +TV or radio announcement and then you + + + align:start position:0% +TV or radio announcement and then you +hope that people will get it and do the + + align:start position:0% +hope that people will get it and do the + + + align:start position:0% +hope that people will get it and do the +right thing. Of course I leave a + + align:start position:0% +right thing. Of course I leave a + + + align:start position:0% +right thing. Of course I leave a +question mark not always. + + align:start position:0% + + + + align:start position:0% + +Now when I talked to people about + + align:start position:0% +Now when I talked to people about + + + align:start position:0% +Now when I talked to people about +climate science, about changing climate + + align:start position:0% +climate science, about changing climate + + + align:start position:0% +climate science, about changing climate +conditions, sea level rise, we need new + + align:start position:0% +conditions, sea level rise, we need new + + + align:start position:0% +conditions, sea level rise, we need new +locations of shelters, about El Nino and + + align:start position:0% +locations of shelters, about El Nino and + + + align:start position:0% +locations of shelters, about El Nino and +changing risks of drought and food + + align:start position:0% +changing risks of drought and food + + + align:start position:0% +changing risks of drought and food +insecurity, about rainfall upstream, + + align:start position:0% +insecurity, about rainfall upstream, + + + align:start position:0% +insecurity, about rainfall upstream, +therefore flooding downstream. I would + + align:start position:0% +therefore flooding downstream. I would + + + align:start position:0% +therefore flooding downstream. I would +be talking science and the people I was + + align:start position:0% +be talking science and the people I was + + + align:start position:0% +be talking science and the people I was +talking to, they had something else to + + align:start position:0% +talking to, they had something else to + + + align:start position:0% +talking to, they had something else to +do. They had to go save lives and they + + align:start position:0% +do. They had to go save lives and they + + + align:start position:0% +do. They had to go save lives and they +were forced into a room just like you + + align:start position:0% +were forced into a room just like you + + + align:start position:0% +were forced into a room just like you +now. + + align:start position:0% +now. + + + align:start position:0% +now. +And I was talking science and I could + + align:start position:0% +And I was talking science and I could + + + align:start position:0% +And I was talking science and I could +feel the extent to which I was + + align:start position:0% +feel the extent to which I was + + + align:start position:0% +feel the extent to which I was +successfully shrinking their + + align:start position:0% + + + + align:start position:0% + +brains. This is a metaphor. There's very + + align:start position:0% +brains. This is a metaphor. There's very + + + align:start position:0% +brains. This is a metaphor. There's very +talented and smart people in the + + align:start position:0% +talented and smart people in the + + + align:start position:0% +talented and smart people in the +humanitarian sector. But my putting them + + align:start position:0% +humanitarian sector. But my putting them + + + align:start position:0% +humanitarian sector. But my putting them +into a passive mode, talking jargon to + + align:start position:0% +into a passive mode, talking jargon to + + + align:start position:0% +into a passive mode, talking jargon to +them, showing maps and graphs and so on + + align:start position:0% +them, showing maps and graphs and so on + + + align:start position:0% +them, showing maps and graphs and so on +was really not accomplishing much. So I + + align:start position:0% +was really not accomplishing much. So I + + + align:start position:0% +was really not accomplishing much. So I +had to try something new. Oh, by the + + align:start position:0% +had to try something new. Oh, by the + + + align:start position:0% +had to try something new. Oh, by the +way, I remember hearing the snoring + + align:start position:0% +way, I remember hearing the snoring + + + align:start position:0% +way, I remember hearing the snoring +while I was talking + + align:start position:0% +while I was talking + + + align:start position:0% +while I was talking +science. So that it was shocking because + + align:start position:0% +science. So that it was shocking because + + + align:start position:0% +science. So that it was shocking because +they were wasting their time listening + + align:start position:0% +they were wasting their time listening + + + align:start position:0% +they were wasting their time listening +to me unsuccessfully try to communicate + + align:start position:0% +to me unsuccessfully try to communicate + + + align:start position:0% +to me unsuccessfully try to communicate +information that can help save lives. So + + align:start position:0% +information that can help save lives. So + + + align:start position:0% +information that can help save lives. So +I started doing other things and we're + + align:start position:0% +I started doing other things and we're + + + align:start position:0% +I started doing other things and we're +going to get a five minute flavor of the + + align:start position:0% +going to get a five minute flavor of the + + + align:start position:0% +going to get a five minute flavor of the +kind of things we're doing. So let's + + align:start position:0% +kind of things we're doing. So let's + + + align:start position:0% +kind of things we're doing. So let's +play. You're a + + align:start position:0% +play. You're a + + + align:start position:0% +play. You're a +team split in half. Each one of you + + align:start position:0% +team split in half. Each one of you + + + align:start position:0% +team split in half. Each one of you +choose. Are you on this half or this + + align:start position:0% +choose. Are you on this half or this + + + align:start position:0% +choose. Are you on this half or this +half? You're a team. You're a team. + + align:start position:0% +half? You're a team. You're a team. + + + align:start position:0% +half? You're a team. You're a team. +You're a team. Four teams. There will be + + align:start position:0% +You're a team. Four teams. There will be + + + align:start position:0% +You're a team. Four teams. There will be +one winning + + align:start position:0% +one winning + + + align:start position:0% +one winning +team. The winning team is the team that + + align:start position:0% +team. The winning team is the team that + + + align:start position:0% +team. The winning team is the team that +has the most people standing by the end + + align:start position:0% +has the most people standing by the end + + + align:start position:0% +has the most people standing by the end +of the game. We'll have a few practice + + align:start position:0% +of the game. We'll have a few practice + + + align:start position:0% +of the game. We'll have a few practice +rounds and then we'll play for real. + + align:start position:0% +rounds and then we'll play for real. + + + align:start position:0% +rounds and then we'll play for real. +Okay. You are not who you think you are. + + align:start position:0% +Okay. You are not who you think you are. + + + align:start position:0% +Okay. You are not who you think you are. +You're not some MIT student or + + align:start position:0% +You're not some MIT student or + + + align:start position:0% +You're not some MIT student or +something. You are magically in the + + align:start position:0% +something. You are magically in the + + + align:start position:0% +something. You are magically in the +magic circle of this game a Red Cross + + align:start position:0% +magic circle of this game a Red Cross + + + align:start position:0% +magic circle of this game a Red Cross +disaster manager. Okay, good. Someone is + + align:start position:0% +disaster manager. Okay, good. Someone is + + + align:start position:0% +disaster manager. Okay, good. Someone is +celebrating. You're hired. We have no + + align:start position:0% +celebrating. You're hired. We have no + + + align:start position:0% +celebrating. You're hired. We have no +money, but you're + + align:start position:0% +money, but you're + + + align:start position:0% +money, but you're +hired. Uh, so there are three kinds of + + align:start position:0% +hired. Uh, so there are three kinds of + + + align:start position:0% +hired. Uh, so there are three kinds of +things you can + + align:start position:0% +things you can + + + align:start position:0% +things you can +do. And everyone will be standing when + + align:start position:0% +do. And everyone will be standing when + + + align:start position:0% +do. And everyone will be standing when +the game begins. One is to go like this. + + align:start position:0% +the game begins. One is to go like this. + + + align:start position:0% +the game begins. One is to go like this. +This means I hope there's good rains. + + align:start position:0% +This means I hope there's good rains. + + + align:start position:0% +This means I hope there's good rains. +I'm going to take advantage of this + + align:start position:0% +I'm going to take advantage of this + + + align:start position:0% +I'm going to take advantage of this +opportunity to do good things when + + align:start position:0% +opportunity to do good things when + + + align:start position:0% +opportunity to do good things when +there's good rains. train people, change + + align:start position:0% +there's good rains. train people, change + + + align:start position:0% +there's good rains. train people, change +the tires of the vehicle, build a + + align:start position:0% +the tires of the vehicle, build a + + + align:start position:0% +the tires of the vehicle, build a +shelter, write a proposal for donors, + + align:start position:0% +shelter, write a proposal for donors, + + + align:start position:0% +shelter, write a proposal for donors, +write a report to the donor that gave me + + align:start position:0% +write a report to the donor that gave me + + + align:start position:0% +write a report to the donor that gave me +money last year. All those things you + + align:start position:0% +money last year. All those things you + + + align:start position:0% +money last year. All those things you +can do when it's a nice day. Now, maybe + + align:start position:0% +can do when it's a nice day. Now, maybe + + + align:start position:0% +can do when it's a nice day. Now, maybe +there's too much rain + + align:start position:0% +there's too much rain + + + align:start position:0% +there's too much rain +coming. Then you can invest in + + align:start position:0% +coming. Then you can invest in + + + align:start position:0% +coming. Then you can invest in +preparedness against too much rain. You + + align:start position:0% +preparedness against too much rain. You + + + align:start position:0% +preparedness against too much rain. You +make this gesture like an umbrella and + + align:start position:0% +make this gesture like an umbrella and + + + align:start position:0% +make this gesture like an umbrella and +it means you're preparing against the + + align:start position:0% +it means you're preparing against the + + + align:start position:0% +it means you're preparing against the +risk of too much rain. This could be + + align:start position:0% +risk of too much rain. This could be + + + align:start position:0% +risk of too much rain. This could be +pre-positioning relief items like tents + + align:start position:0% +pre-positioning relief items like tents + + + align:start position:0% +pre-positioning relief items like tents +for those who have to be displaced with + + align:start position:0% +for those who have to be displaced with + + + align:start position:0% +for those who have to be displaced with +the flood. But it's better to do it + + align:start position:0% +the flood. But it's better to do it + + + align:start position:0% +the flood. But it's better to do it +before the flood because if you wait for + + align:start position:0% +before the flood because if you wait for + + + align:start position:0% +before the flood because if you wait for +the flood, then the bridge has been + + align:start position:0% +the flood, then the bridge has been + + + align:start position:0% +the flood, then the bridge has been +washed away and you have no way to take + + align:start position:0% +washed away and you have no way to take + + + align:start position:0% +washed away and you have no way to take +tents to the other side. The other + + align:start position:0% +tents to the other side. The other + + + align:start position:0% +tents to the other side. The other +option you have is to do a a bucket, + + align:start position:0% +option you have is to do a a bucket, + + + align:start position:0% +option you have is to do a a bucket, +something to hold water from the sky. If + + align:start position:0% +something to hold water from the sky. If + + + align:start position:0% +something to hold water from the sky. If +there's a risk of a drought, you want to + + align:start position:0% +there's a risk of a drought, you want to + + + align:start position:0% +there's a risk of a drought, you want to +collect water before the drought so + + align:start position:0% +collect water before the drought so + + + align:start position:0% +collect water before the drought so +people can have water to drink. So each + + align:start position:0% +people can have water to drink. So each + + + align:start position:0% +people can have water to drink. So each +one of you can do three things. Good + + align:start position:0% +one of you can do three things. Good + + + align:start position:0% +one of you can do three things. Good +rains you go like this. Too much rain + + align:start position:0% +rains you go like this. Too much rain + + + align:start position:0% +rains you go like this. Too much rain +you go like that. Too little rain you go + + align:start position:0% +you go like that. Too little rain you go + + + align:start position:0% +you go like that. Too little rain you go +like this. What determines + + align:start position:0% +like this. What determines + + + align:start position:0% +like this. What determines +rains? The probability distribution + + align:start position:0% +rains? The probability distribution + + + align:start position:0% +rains? The probability distribution +function of precipitation based on the + + align:start position:0% +function of precipitation based on the + + + align:start position:0% +function of precipitation based on the +past + + align:start position:0% +past + + + align:start position:0% +past +record. So you guys are affected by this + + align:start position:0% +record. So you guys are affected by this + + + align:start position:0% +record. So you guys are affected by this +PDF. This die. You guys are affected by + + align:start position:0% +PDF. This die. You guys are affected by + + + align:start position:0% +PDF. This die. You guys are affected by +this + + align:start position:0% +this + + + align:start position:0% +this +one. A6 is what? Too much rain. It's a + + align:start position:0% +one. A6 is what? Too much rain. It's a + + + align:start position:0% +one. A6 is what? Too much rain. It's a +good idea to be like this. If you're not + + align:start position:0% +good idea to be like this. If you're not + + + align:start position:0% +good idea to be like this. If you're not +like this, you sit down. You got it + + align:start position:0% +like this, you sit down. You got it + + + align:start position:0% +like this, you sit down. You got it +wrong. A one is what? Too little rain. + + align:start position:0% +wrong. A one is what? Too little rain. + + + align:start position:0% +wrong. A one is what? Too little rain. +It's a good idea to be like that. + + align:start position:0% +It's a good idea to be like that. + + + align:start position:0% +It's a good idea to be like that. +Otherwise, you got it wrong. You sit + + align:start position:0% +Otherwise, you got it wrong. You sit + + + align:start position:0% +Otherwise, you got it wrong. You sit +down. Everything in between is what? + + align:start position:0% +down. Everything in between is what? + + + align:start position:0% +down. Everything in between is what? +Good range. You better go like this or + + align:start position:0% +Good range. You better go like this or + + + align:start position:0% +Good range. You better go like this or +you got it wrong. Practice round. + + align:start position:0% +you got it wrong. Practice round. + + + align:start position:0% +you got it wrong. Practice round. +Everyone stand + + align:start position:0% +Everyone stand + + + align:start position:0% +Everyone stand +up because the + + align:start position:0% +up because the + + + align:start position:0% +up because the +winner is going to be well, let me show + + align:start position:0% +winner is going to be well, let me show + + + align:start position:0% +winner is going to be well, let me show +this. Losing players all that get it + + align:start position:0% +this. Losing players all that get it + + + align:start position:0% +this. Losing players all that get it +wrong. You sit down, you're basically + + align:start position:0% +wrong. You sit down, you're basically + + + align:start position:0% +wrong. You sit down, you're basically +not fired, but people suffer because of + + align:start position:0% +not fired, but people suffer because of + + + align:start position:0% +not fired, but people suffer because of +your bad + + align:start position:0% +your bad + + + align:start position:0% +your bad +decisions. And uh the winning team is + + align:start position:0% +decisions. And uh the winning team is + + + align:start position:0% +decisions. And uh the winning team is +the team that at the end of the few + + align:start position:0% +the team that at the end of the few + + + align:start position:0% +the team that at the end of the few +rounds, I will arbitrarily declare the + + align:start position:0% +rounds, I will arbitrarily declare the + + + align:start position:0% +rounds, I will arbitrarily declare the +end because in the real world there is + + align:start position:0% +end because in the real world there is + + + align:start position:0% +end because in the real world there is +no end. Uh we'll have three practice + + align:start position:0% +no end. Uh we'll have three practice + + + align:start position:0% +no end. Uh we'll have three practice +rounds and then for real uh most people + + align:start position:0% +rounds and then for real uh most people + + + align:start position:0% +rounds and then for real uh most people +standing. So if you guys have two people + + align:start position:0% +standing. So if you guys have two people + + + align:start position:0% +standing. So if you guys have two people +standing and you have 10 people standing + + align:start position:0% +standing and you have 10 people standing + + + align:start position:0% +standing and you have 10 people standing +and they have less than 10, you are the + + align:start position:0% +and they have less than 10, you are the + + + align:start position:0% +and they have less than 10, you are the +winners and the winning team will win a + + align:start position:0% +winners and the winning team will win a + + + align:start position:0% +winners and the winning team will win a +publication. I will explain how you'll + + align:start position:0% +publication. I will explain how you'll + + + align:start position:0% +publication. I will explain how you'll +have to fight over + + align:start position:0% +have to fight over + + + align:start position:0% +have to fight over +it. So + + align:start position:0% +it. So + + + align:start position:0% +it. So +uh let's go back + + align:start position:0% +uh let's go back + + + align:start position:0% +uh let's go back +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +to uh actually here so that you remember + + align:start position:0% +to uh actually here so that you remember + + + align:start position:0% +to uh actually here so that you remember +the three things you can do. Each one of + + align:start position:0% +the three things you can do. Each one of + + + align:start position:0% +the three things you can do. Each one of +you has to make a decision. Two, three, + + align:start position:0% +you has to make a decision. Two, three, + + + align:start position:0% +you has to make a decision. Two, three, +four or five. Five, it's good idea to do + + align:start position:0% +four or five. Five, it's good idea to do + + + align:start position:0% +four or five. Five, it's good idea to do +this. Six, good idea to do that, one + + align:start position:0% +this. Six, good idea to do that, one + + + align:start position:0% +this. Six, good idea to do that, one +good idea to do that. You can have a + + align:start position:0% +good idea to do that. You can have a + + + align:start position:0% +good idea to do that. You can have a +collective conversation, but each one of + + align:start position:0% +collective conversation, but each one of + + + align:start position:0% +collective conversation, but each one of +you has to be making one of those three. + + align:start position:0% +you has to be making one of those three. + + + align:start position:0% +you has to be making one of those three. +If you're making none of those three, + + align:start position:0% +If you're making none of those three, + + + align:start position:0% +If you're making none of those three, +you sit down, you're fired. You have one + + align:start position:0% +you sit down, you're fired. You have one + + + align:start position:0% +you sit down, you're fired. You have one +30 seconds to consult with your teams. + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +The rains are coming. Make your + + align:start position:0% +The rains are coming. Make your + + + align:start position:0% +The rains are coming. Make your +decisions. 10 9 8 7 6 + + align:start position:0% +decisions. 10 9 8 7 6 + + + align:start position:0% +decisions. 10 9 8 7 6 +5 4 three. When I say stop, you have to + + align:start position:0% +5 4 three. When I say stop, you have to + + + align:start position:0% +5 4 three. When I say stop, you have to +be in the position. + + align:start position:0% +be in the position. + + + align:start position:0% +be in the position. +Three, + + align:start position:0% +Three, + + + align:start position:0% +Three, +two, one, and be in the position or + + align:start position:0% +two, one, and be in the position or + + + align:start position:0% +two, one, and be in the position or +you're fired. Stop. Okay, here we see a + + align:start position:0% +you're fired. Stop. Okay, here we see a + + + align:start position:0% +you're fired. Stop. Okay, here we see a +lot of thumbs up. Two buckets, two non + + align:start position:0% +lot of thumbs up. Two buckets, two non + + + align:start position:0% +lot of thumbs up. Two buckets, two non +two umbrellas. roughly the same kind of + + align:start position:0% +two umbrellas. roughly the same kind of + + + align:start position:0% +two umbrellas. roughly the same kind of +configuration. All right, let's see what + + align:start position:0% +configuration. All right, let's see what + + + align:start position:0% +configuration. All right, let's see what +happens to this half camera. I wish you + + align:start position:0% +happens to this half camera. I wish you + + + align:start position:0% +happens to this half camera. I wish you +good luck. This is for you + + align:start position:0% +good luck. This is for you + + + align:start position:0% +good luck. This is for you +guys. It is + + align:start position:0% +guys. It is + + + align:start position:0% +guys. It is +a five. So, if you're like that, stay + + align:start position:0% +a five. So, if you're like that, stay + + + align:start position:0% +a five. So, if you're like that, stay +standing otherwise sit down. You didn't + + align:start position:0% +standing otherwise sit down. You didn't + + + align:start position:0% +standing otherwise sit down. You didn't +invest in the good things you could have + + align:start position:0% +invest in the good things you could have + + + align:start position:0% +invest in the good things you could have +done for you guys. Let's see what + + align:start position:0% +done for you guys. Let's see what + + + align:start position:0% +done for you guys. Let's see what +happens. And it is a four. If you're + + align:start position:0% +happens. And it is a four. If you're + + + align:start position:0% +happens. And it is a four. If you're +like that, stay standing. Otherwise, sit + + align:start position:0% +like that, stay standing. Otherwise, sit + + + align:start position:0% +like that, stay standing. Otherwise, sit +down. Moving on to year two practice + + align:start position:0% +down. Moving on to year two practice + + + align:start position:0% +down. Moving on to year two practice +round. What are you going to do? + + align:start position:0% +round. What are you going to do? + + + align:start position:0% +round. What are you going to do? +You have those who are sitting stay + + align:start position:0% +You have those who are sitting stay + + + align:start position:0% +You have those who are sitting stay +sitting but can give advice. + + align:start position:0% +sitting but can give advice. + + + align:start position:0% +sitting but can give advice. +[Music] + + align:start position:0% + + + + align:start position:0% + +Okay. Make your decisions. Five 4 3 2 + + align:start position:0% +Okay. Make your decisions. Five 4 3 2 + + + align:start position:0% +Okay. Make your decisions. Five 4 3 2 +one and + + align:start position:0% +one and + + + align:start position:0% +one and +stop. Lots of thumbs up. Are you with + + align:start position:0% +stop. Lots of thumbs up. Are you with + + + align:start position:0% +stop. Lots of thumbs up. Are you with +these guys? All right. So, you're the + + align:start position:0% +these guys? All right. So, you're the + + + align:start position:0% +these guys? All right. So, you're the +only umbrella in this side. Let's see + + align:start position:0% +only umbrella in this side. Let's see + + + align:start position:0% +only umbrella in this side. Let's see +how it happens. There we + + align:start position:0% +how it happens. There we + + + align:start position:0% +how it happens. There we +go. And there's a four. Thumbs up. Stay + + align:start position:0% +go. And there's a four. Thumbs up. Stay + + + align:start position:0% +go. And there's a four. Thumbs up. Stay +standing. Otherwise, sit down. This + + align:start position:0% +standing. Otherwise, sit down. This + + + align:start position:0% +standing. Otherwise, sit down. This +team, not surprisingly, is weak. They + + align:start position:0% +team, not surprisingly, is weak. They + + + align:start position:0% +team, not surprisingly, is weak. They +started with few over here. You guys, + + align:start position:0% +started with few over here. You guys, + + + align:start position:0% +started with few over here. You guys, +there we go. + + align:start position:0% +there we go. + + + align:start position:0% +there we go. +A two. So, if you're like that or like + + align:start position:0% +A two. So, if you're like that or like + + + align:start position:0% +A two. So, if you're like that or like +that, sit down. Now, last practice + + align:start position:0% +that, sit down. Now, last practice + + + align:start position:0% +that, sit down. Now, last practice +round. + + align:start position:0% + + + + align:start position:0% + +You receive this facts. + + align:start position:0% + + + + align:start position:0% + +That's all you know. You got this facts. + + align:start position:0% +That's all you know. You got this facts. + + + align:start position:0% +That's all you know. You got this facts. +I am answering your question by saying + + align:start position:0% +I am answering your question by saying + + + align:start position:0% +I am answering your question by saying +all you got is + + align:start position:0% +all you got is + + + align:start position:0% +all you got is +this. There's a deliberate scarcity of + + align:start position:0% +this. There's a deliberate scarcity of + + + align:start position:0% +this. There's a deliberate scarcity of +information. + + align:start position:0% +information. + + + align:start position:0% +information. +You have 30 seconds to make your + + align:start position:0% +You have 30 seconds to make your + + + align:start position:0% +You have 30 seconds to make your +decisions. Wait, where are we? You are + + align:start position:0% +decisions. Wait, where are we? You are + + + align:start position:0% +decisions. Wait, where are we? You are +in the place with the green pixel. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +10 seconds left. + + align:start position:0% +10 seconds left. + + + align:start position:0% +10 seconds left. +Five. Four. Three. + + align:start position:0% +Five. Four. Three. + + + align:start position:0% +Five. Four. Three. +two one and stop. Okay, so in this team + + align:start position:0% +two one and stop. Okay, so in this team + + + align:start position:0% +two one and stop. Okay, so in this team +there's only three left. Onethird are + + align:start position:0% +there's only three left. Onethird are + + + align:start position:0% +there's only three left. Onethird are +investing in in too much rain. Here we + + align:start position:0% +investing in in too much rain. Here we + + + align:start position:0% +investing in in too much rain. Here we +have about eight or so half or more are + + align:start position:0% +have about eight or so half or more are + + + align:start position:0% +have about eight or so half or more are +investing in this. No one Oh, only one + + align:start position:0% +investing in this. No one Oh, only one + + + align:start position:0% +investing in this. No one Oh, only one +person is going for drought. Over here, + + align:start position:0% +person is going for drought. Over here, + + + align:start position:0% +person is going for drought. Over here, +all right, I see over here we have + + align:start position:0% +all right, I see over here we have + + + align:start position:0% +all right, I see over here we have +three. So about half also investing in + + align:start position:0% +three. So about half also investing in + + + align:start position:0% +three. So about half also investing in +flood protection. Over here we have more + + align:start position:0% +flood protection. Over here we have more + + + align:start position:0% +flood protection. Over here we have more +than before. Two out of six. Well, of + + align:start position:0% +than before. Two out of six. Well, of + + + align:start position:0% +than before. Two out of six. Well, of +course, what this says is that on a + + align:start position:0% +course, what this says is that on a + + + align:start position:0% +course, what this says is that on a +normal year, the chances of this is 15% + + align:start position:0% +normal year, the chances of this is 15% + + + align:start position:0% +normal year, the chances of this is 15% +or about one in six. One in six is + + align:start position:0% +or about one in six. One in six is + + + align:start position:0% +or about one in six. One in six is +16%. But this year, because of unusual + + align:start position:0% +16%. But this year, because of unusual + + + align:start position:0% +16%. But this year, because of unusual +conditions, it's a flip of the coin. So, + + align:start position:0% +conditions, it's a flip of the coin. So, + + + align:start position:0% +conditions, it's a flip of the coin. So, +for you guys, I'm going to flip this + + align:start position:0% +for you guys, I'm going to flip this + + + align:start position:0% +for you guys, I'm going to flip this +one. Of course, you cannot now change + + align:start position:0% +one. Of course, you cannot now change + + + align:start position:0% +one. Of course, you cannot now change +your your decision, right? It's too late + + align:start position:0% +your your decision, right? It's too late + + + align:start position:0% +your your decision, right? It's too late +now. You either sent the tents or bought + + align:start position:0% +now. You either sent the tents or bought + + + align:start position:0% +now. You either sent the tents or bought +the cement for the shelter. So, I'm + + align:start position:0% +the cement for the shelter. So, I'm + + + align:start position:0% +the cement for the shelter. So, I'm +going to throw this up in the air. If it + + align:start position:0% +going to throw this up in the air. If it + + + align:start position:0% +going to throw this up in the air. If it +falls like this, no problem. It's like a + + align:start position:0% +falls like this, no problem. It's like a + + + align:start position:0% +falls like this, no problem. It's like a +three. If it falls like this, too much + + align:start position:0% +three. If it falls like this, too much + + + align:start position:0% +three. If it falls like this, too much +rain, 50% chance or so. It's a good idea + + align:start position:0% +rain, 50% chance or so. It's a good idea + + + align:start position:0% +rain, 50% chance or so. It's a good idea +to have the umbrella. Otherwise, you sit + + align:start position:0% +to have the umbrella. Otherwise, you sit + + + align:start position:0% +to have the umbrella. Otherwise, you sit +down. If it falls like this, meaning it + + align:start position:0% +down. If it falls like this, meaning it + + + align:start position:0% +down. If it falls like this, meaning it +stops moving and it stays standing, it's + + align:start position:0% +stops moving and it stays standing, it's + + + align:start position:0% +stops moving and it stays standing, it's +a good idea to have a + + align:start position:0% + + + + align:start position:0% + +bucket. You guys will get the yellow + + align:start position:0% +bucket. You guys will get the yellow + + + align:start position:0% +bucket. You guys will get the yellow +one. Ready, set, and go. + + align:start position:0% +one. Ready, set, and go. + + + align:start position:0% +one. Ready, set, and go. +flood. Someone's very + + align:start position:0% +flood. Someone's very + + + align:start position:0% +flood. Someone's very +happy. We love it. So, if you're not + + align:start position:0% +happy. We love it. So, if you're not + + + align:start position:0% +happy. We love it. So, if you're not +like this, you have to sit down. Now, + + align:start position:0% +like this, you have to sit down. Now, + + + align:start position:0% +like this, you have to sit down. Now, +notice this interesting uh feature of + + align:start position:0% +notice this interesting uh feature of + + + align:start position:0% +notice this interesting uh feature of +reality. If you take the right action, + + align:start position:0% +reality. If you take the right action, + + + align:start position:0% +reality. If you take the right action, +an extreme event is not a disaster. He + + align:start position:0% +an extreme event is not a disaster. He + + + align:start position:0% +an extreme event is not a disaster. He +was prepared. He's happy that the + + align:start position:0% +was prepared. He's happy that the + + + align:start position:0% +was prepared. He's happy that the +disaster happened because he was + + align:start position:0% +disaster happened because he was + + + align:start position:0% +disaster happened because he was +prepared, right? Which is a good thing. + + align:start position:0% +prepared, right? Which is a good thing. + + + align:start position:0% +prepared, right? Which is a good thing. +A disaster is only a disaster if it + + align:start position:0% +A disaster is only a disaster if it + + + align:start position:0% +A disaster is only a disaster if it +leads to negative outcomes. If someone + + align:start position:0% +leads to negative outcomes. If someone + + + align:start position:0% +leads to negative outcomes. If someone +tells you it's going to be 110 degrees + + align:start position:0% +tells you it's going to be 110 degrees + + + align:start position:0% +tells you it's going to be 110 degrees +today and you have some health + + align:start position:0% +today and you have some health + + + align:start position:0% +today and you have some health +condition, you turn on your + + align:start position:0% +condition, you turn on your + + + align:start position:0% +condition, you turn on your +conditioning, there's no disaster unless + + align:start position:0% +conditioning, there's no disaster unless + + + align:start position:0% +conditioning, there's no disaster unless +there's no energy for your air + + align:start position:0% +there's no energy for your air + + + align:start position:0% +there's no energy for your air +conditioning, right? Okay, let's see + + align:start position:0% +conditioning, right? Okay, let's see + + + align:start position:0% +conditioning, right? Okay, let's see +about you + + align:start position:0% + + + + align:start position:0% + +guys. You also got a flood. So, if + + align:start position:0% +guys. You also got a flood. So, if + + + align:start position:0% +guys. You also got a flood. So, if +you're like this, stay standing, + + align:start position:0% +you're like this, stay standing, + + + align:start position:0% +you're like this, stay standing, +otherwise sit down. If this were the end + + align:start position:0% +otherwise sit down. If this were the end + + + align:start position:0% +otherwise sit down. If this were the end +of the real game, we'd have three + + align:start position:0% +of the real game, we'd have three + + + align:start position:0% +of the real game, we'd have three +standing here. No other team has three, + + align:start position:0% +standing here. No other team has three, + + + align:start position:0% +standing here. No other team has three, +so you would be declared the winning + + align:start position:0% +so you would be declared the winning + + + align:start position:0% +so you would be declared the winning +team. + + align:start position:0% +team. + + + align:start position:0% +team. +Oh, you got four. So, my + + align:start position:0% +Oh, you got four. So, my + + + align:start position:0% +Oh, you got four. So, my +apologies. You would be declared the + + align:start position:0% +apologies. You would be declared the + + + align:start position:0% +apologies. You would be declared the +winning team. Congratulations. + + align:start position:0% +winning team. Congratulations. + + + align:start position:0% +winning team. Congratulations. +Now, thank + + align:start position:0% +Now, thank + + + align:start position:0% +Now, thank +you, everyone, sit down. And now we're + + align:start position:0% +you, everyone, sit down. And now we're + + + align:start position:0% +you, everyone, sit down. And now we're +going to see what you would do for real + + align:start position:0% +going to see what you would do for real + + + align:start position:0% +going to see what you would do for real +in this scenario where we have climate + + align:start position:0% +in this scenario where we have climate + + + align:start position:0% +in this scenario where we have climate +change. Have you heard climate + + align:start position:0% +change. Have you heard climate + + + align:start position:0% +change. Have you heard climate +change? Things are changing. This is + + align:start position:0% +change? Things are changing. This is + + + align:start position:0% +change? Things are changing. This is +based on the past record of + + align:start position:0% +based on the past record of + + + align:start position:0% +based on the past record of +precipitation. But the past no longer + + align:start position:0% +precipitation. But the past no longer + + + align:start position:0% +precipitation. But the past no longer +explains the + + align:start position:0% +explains the + + + align:start position:0% +explains the +present. Things are changing. So I + + align:start position:0% +present. Things are changing. So I + + + align:start position:0% +present. Things are changing. So I +hereby introduce you to climate + + align:start position:0% + + + + align:start position:0% + +change. This one is going to be for you + + align:start position:0% +change. This one is going to be for you + + + align:start position:0% +change. This one is going to be for you +guys. I'm going to throw this up in the + + align:start position:0% +guys. I'm going to throw this up in the + + + align:start position:0% +guys. I'm going to throw this up in the +air with some spin just like the dice. + + align:start position:0% +air with some spin just like the dice. + + + align:start position:0% +air with some spin just like the dice. +Look at you. I love this face. This is a + + align:start position:0% +Look at you. I love this face. This is a + + + align:start position:0% +Look at you. I love this face. This is a +very productive + + align:start position:0% +very productive + + + align:start position:0% +very productive +silence. I'm going to throw it up in the + + align:start position:0% +silence. I'm going to throw it up in the + + + align:start position:0% +silence. I'm going to throw it up in the +air. Is if it falls like this, it means + + align:start position:0% +air. Is if it falls like this, it means + + + align:start position:0% +air. Is if it falls like this, it means +normal rains. No problem. It's like a + + align:start position:0% +normal rains. No problem. It's like a + + + align:start position:0% +normal rains. No problem. It's like a +three. Good idea to go like that. If it + + align:start position:0% +three. Good idea to go like that. If it + + + align:start position:0% +three. Good idea to go like that. If it +falls like this, too much rain. Good + + align:start position:0% +falls like this, too much rain. Good + + + align:start position:0% +falls like this, too much rain. Good +idea to invest in your umbrella. If it + + align:start position:0% +idea to invest in your umbrella. If it + + + align:start position:0% +idea to invest in your umbrella. If it +falls like + + align:start position:0% +falls like + + + align:start position:0% +falls like +that, what is it representing? It's too + + align:start position:0% +that, what is it representing? It's too + + + align:start position:0% +that, what is it representing? It's too +little rain bucket. Good idea to go like + + align:start position:0% +little rain bucket. Good idea to go like + + + align:start position:0% +little rain bucket. Good idea to go like +this. This is for you guys. We're going + + align:start position:0% +this. This is for you guys. We're going + + + align:start position:0% +this. This is for you guys. We're going +to imagine we play three consecutive + + align:start position:0% +to imagine we play three consecutive + + + align:start position:0% +to imagine we play three consecutive +years. Can you hold this for me? No + + align:start position:0% +years. Can you hold this for me? No + + + align:start position:0% +years. Can you hold this for me? No +spinning, please. No throwing. For the + + align:start position:0% +spinning, please. No throwing. For the + + + align:start position:0% +spinning, please. No throwing. For the +other half, we have this other one, + + align:start position:0% +other half, we have this other one, + + + align:start position:0% +other half, we have this other one, +which is also climate change, but the + + align:start position:0% +which is also climate change, but the + + + align:start position:0% +which is also climate change, but the +climate doesn't change in the same way + + align:start position:0% +climate doesn't change in the same way + + + align:start position:0% +climate doesn't change in the same way +in every place. So, I'm going to throw + + align:start position:0% +in every place. So, I'm going to throw + + + align:start position:0% +in every place. So, I'm going to throw +this up in the air. If it falls like + + align:start position:0% +this up in the air. If it falls like + + + align:start position:0% +this up in the air. If it falls like +this, it means no problem. Good idea to + + align:start position:0% +this, it means no problem. Good idea to + + + align:start position:0% +this, it means no problem. Good idea to +go for thumbs up. If it falls like this, + + align:start position:0% +go for thumbs up. If it falls like this, + + + align:start position:0% +go for thumbs up. If it falls like this, +too much rain. If it falls like this, + + align:start position:0% +too much rain. If it falls like this, + + + align:start position:0% +too much rain. If it falls like this, +too little rain, go for that. + + align:start position:0% +too little rain, go for that. + + + align:start position:0% +too little rain, go for that. +As a team, you have two minutes to come + + align:start position:0% +As a team, you have two minutes to come + + + align:start position:0% +As a team, you have two minutes to come +up with a decision or more likely one + + align:start position:0% +up with a decision or more likely one + + + align:start position:0% +up with a decision or more likely one +minute. Go. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +Less than a minute. + + align:start position:0% + + + + align:start position:0% + +30 seconds. + + align:start position:0% + + + + align:start position:0% + +10 seconds. + + align:start position:0% +10 seconds. + + + align:start position:0% +10 seconds. +Everybody stand up. + + align:start position:0% +Everybody stand up. + + + align:start position:0% +Everybody stand up. +Make your decisions. Five, + + align:start position:0% +Make your decisions. Five, + + + align:start position:0% +Make your decisions. Five, +four, + + align:start position:0% +four, + + + align:start position:0% +four, +three, + + align:start position:0% +three, + + + align:start position:0% +three, +two, + + align:start position:0% +two, + + + align:start position:0% +two, +one, + + align:start position:0% +one, + + + align:start position:0% +one, +and + + align:start position:0% + + + + align:start position:0% + +stop. All right. + + align:start position:0% +stop. All right. + + + align:start position:0% +stop. All right. +Compared to the first round with the + + align:start position:0% +Compared to the first round with the + + + align:start position:0% +Compared to the first round with the +dye, there's much more proportion of + + align:start position:0% +dye, there's much more proportion of + + + align:start position:0% +dye, there's much more proportion of +people investing either in too much rain + + align:start position:0% +people investing either in too much rain + + + align:start position:0% +people investing either in too much rain +or in too little rain. Can you notice + + align:start position:0% +or in too little rain. Can you notice + + + align:start position:0% +or in too little rain. Can you notice +any difference between this half and + + align:start position:0% +any difference between this half and + + + align:start position:0% +any difference between this half and +that + + align:start position:0% + + + + align:start position:0% + +half? Not really. Very + + align:start position:0% +half? Not really. Very + + + align:start position:0% +half? Not really. Very +substantial. Phenomenally different + + align:start position:0% +substantial. Phenomenally different + + + align:start position:0% +substantial. Phenomenally different +climate change projections coming from + + align:start position:0% +climate change projections coming from + + + align:start position:0% +climate change projections coming from +science. This could be like the IPCC + + align:start position:0% +science. This could be like the IPCC + + + align:start position:0% +science. This could be like the IPCC +report, right? And yet you don't know + + align:start position:0% +report, right? And yet you don't know + + + align:start position:0% +report, right? And yet you don't know +how to interpret those differences. + + align:start position:0% +how to interpret those differences. + + + align:start position:0% +how to interpret those differences. +Thank you for incarnating what happens + + align:start position:0% +Thank you for incarnating what happens + + + align:start position:0% +Thank you for incarnating what happens +in the real world. Okay, we just are + + align:start position:0% +in the real world. Okay, we just are + + + align:start position:0% +in the real world. Okay, we just are +very confused. We understand that the + + align:start position:0% +very confused. We understand that the + + + align:start position:0% +very confused. We understand that the +risks are higher. So I will not roll it + + align:start position:0% +risks are higher. So I will not roll it + + + align:start position:0% +risks are higher. So I will not roll it +because I'd rather keep sharing with you + + align:start position:0% +because I'd rather keep sharing with you + + + align:start position:0% +because I'd rather keep sharing with you +some of the things we're doing. But I + + align:start position:0% +some of the things we're doing. But I + + + align:start position:0% +some of the things we're doing. But I +can share with you that you already + + align:start position:0% +can share with you that you already + + + align:start position:0% +can share with you that you already +have. No, I want to know. Let's let's + + align:start position:0% +have. No, I want to know. Let's let's + + + align:start position:0% +have. No, I want to know. Let's let's +play. I want to see what the climate + + align:start position:0% +play. I want to see what the climate + + + align:start position:0% +play. I want to see what the climate +will bring. And that's exactly the + + align:start position:0% +will bring. And that's exactly the + + + align:start position:0% +will bring. And that's exactly the +point. We are creating your appetite for + + align:start position:0% +point. We are creating your appetite for + + + align:start position:0% +point. We are creating your appetite for +learning. And that's what games can help + + align:start position:0% +learning. And that's what games can help + + + align:start position:0% +learning. And that's what games can help +me and my colleagues do. We have a bunch + + align:start position:0% +me and my colleagues do. We have a bunch + + + align:start position:0% +me and my colleagues do. We have a bunch +of Red Cross people and suddenly they + + align:start position:0% +of Red Cross people and suddenly they + + + align:start position:0% +of Red Cross people and suddenly they +want to know the real climate projection + + align:start position:0% +want to know the real climate projection + + + align:start position:0% +want to know the real climate projection +for their project site. All right, + + align:start position:0% +for their project site. All right, + + + align:start position:0% +for their project site. All right, +everyone can sit + + align:start position:0% +everyone can sit + + + align:start position:0% +everyone can sit +down. So we went through this. Oops, + + align:start position:0% +down. So we went through this. Oops, + + + align:start position:0% +down. So we went through this. Oops, +sorry. Uh, this is where I wanted to go. + + align:start position:0% +sorry. Uh, this is where I wanted to go. + + + align:start position:0% +sorry. Uh, this is where I wanted to go. +So that's the facts that Yousef + + align:start position:0% +So that's the facts that Yousef + + + align:start position:0% +So that's the facts that Yousef +received. You played and you had many + + align:start position:0% +received. You played and you had many + + + align:start position:0% +received. You played and you had many +more people going like that which is the + + align:start position:0% +more people going like that which is the + + + align:start position:0% +more people going like that which is the +right thing to do. Now it's 50/50. It + + align:start position:0% +right thing to do. Now it's 50/50. It + + + align:start position:0% +right thing to do. Now it's 50/50. It +could have been that it doesn't flood. + + align:start position:0% +could have been that it doesn't flood. + + + align:start position:0% +could have been that it doesn't flood. +But if you understand the risks, you can + + align:start position:0% +But if you understand the risks, you can + + + align:start position:0% +But if you understand the risks, you can +say to the face of your staff, to the + + align:start position:0% +say to the face of your staff, to the + + + align:start position:0% +say to the face of your staff, to the +face of your donor, to the face of the + + align:start position:0% +face of your donor, to the face of the + + + align:start position:0% +face of your donor, to the face of the +communities you're helping, look, I had + + align:start position:0% +communities you're helping, look, I had + + + align:start position:0% +communities you're helping, look, I had +reasons to act that way because it went + + align:start position:0% +reasons to act that way because it went + + + align:start position:0% +reasons to act that way because it went +from one in six to one in two. And games + + align:start position:0% +from one in six to one in two. And games + + + align:start position:0% +from one in six to one in two. And games +can help process that. What games can do + + align:start position:0% +can help process that. What games can do + + + align:start position:0% +can help process that. What games can do +is to help embed information into a + + align:start position:0% +is to help embed information into a + + + align:start position:0% +is to help embed information into a +system where decisions have consequences + + align:start position:0% +system where decisions have consequences + + + align:start position:0% +system where decisions have consequences +and shape the information that becomes + + align:start position:0% +and shape the information that becomes + + + align:start position:0% +and shape the information that becomes +available for the next turn. So you can + + align:start position:0% +available for the next turn. So you can + + + align:start position:0% +available for the next turn. So you can +have more or less resources and so on. + + align:start position:0% +have more or less resources and so on. + + + align:start position:0% +have more or less resources and so on. +Yes. Yeah. + + align:start position:0% + + + + align:start position:0% + +Let's say + + align:start position:0% +Let's say + + + align:start position:0% +Let's say +it + + align:start position:0% +it + + + align:start position:0% +it +right. Why not invest more? + + align:start position:0% + + + + align:start position:0% + +Exactly. Why not invest more in better + + align:start position:0% +Exactly. Why not invest more in better + + + align:start position:0% +Exactly. Why not invest more in better +everything? We can, but we don't have + + align:start position:0% +everything? We can, but we don't have + + + align:start position:0% +everything? We can, but we don't have +the money, right? So we're talking to + + align:start position:0% +the money, right? So we're talking to + + + align:start position:0% +the money, right? So we're talking to +Lincoln Lab and donors and so on to help + + align:start position:0% +Lincoln Lab and donors and so on to help + + + align:start position:0% +Lincoln Lab and donors and so on to help +us improve our ability to sense what is + + align:start position:0% +us improve our ability to sense what is + + + align:start position:0% +us improve our ability to sense what is +going on in terms of hazards including + + align:start position:0% +going on in terms of hazards including + + + align:start position:0% +going on in terms of hazards including +too much train to little rain and other + + align:start position:0% +too much train to little rain and other + + + align:start position:0% +too much train to little rain and other +things including vulnerabilities. It's + + align:start position:0% +things including vulnerabilities. It's + + + align:start position:0% +things including vulnerabilities. It's +not the same for me to be exposed to 100 + + align:start position:0% +not the same for me to be exposed to 100 + + + align:start position:0% +not the same for me to be exposed to 100 +degrees of heat wave versus to an + + align:start position:0% +degrees of heat wave versus to an + + + align:start position:0% +degrees of heat wave versus to an +elderly person with asthma. Right? And + + align:start position:0% +elderly person with asthma. Right? And + + + align:start position:0% +elderly person with asthma. Right? And +the same with capacities. What do we + + align:start position:0% +the same with capacities. What do we + + + align:start position:0% +the same with capacities. What do we +have in terms of skills and knowledge, + + align:start position:0% +have in terms of skills and knowledge, + + + align:start position:0% +have in terms of skills and knowledge, +in terms of equipment, in terms of + + align:start position:0% +in terms of equipment, in terms of + + + align:start position:0% +in terms of equipment, in terms of +experience? Uh, the disease chikonga, + + align:start position:0% +experience? Uh, the disease chikonga, + + + align:start position:0% +experience? Uh, the disease chikonga, +has anyone heard of + + align:start position:0% +has anyone heard of + + + align:start position:0% +has anyone heard of +it? So, what are you going to do if an + + align:start position:0% +it? So, what are you going to do if an + + + align:start position:0% +it? So, what are you going to do if an +outbreak of Chikongunia comes out to MIT + + align:start position:0% +outbreak of Chikongunia comes out to MIT + + + align:start position:0% +outbreak of Chikongunia comes out to MIT +tomorrow? Right? Knowing can help, + + align:start position:0% +tomorrow? Right? Knowing can help, + + + align:start position:0% +tomorrow? Right? Knowing can help, +sensing can help make better decisions. + + align:start position:0% +sensing can help make better decisions. + + + align:start position:0% +sensing can help make better decisions. +In short, o in my experience, only games + + align:start position:0% +In short, o in my experience, only games + + + align:start position:0% +In short, o in my experience, only games +can do this. Only games can get a bunch + + align:start position:0% +can do this. Only games can get a bunch + + + align:start position:0% +can do this. Only games can get a bunch +of people together and in a very short + + align:start position:0% +of people together and in a very short + + + align:start position:0% +of people together and in a very short +time understand the role of information + + align:start position:0% +time understand the role of information + + + align:start position:0% +time understand the role of information +in the context of decisions that will + + align:start position:0% +in the context of decisions that will + + + align:start position:0% +in the context of decisions that will +have consequences including life-saving + + align:start position:0% +have consequences including life-saving + + + align:start position:0% +have consequences including life-saving +or life- losing consequences. Uh this is + + align:start position:0% +or life- losing consequences. Uh this is + + + align:start position:0% +or life- losing consequences. Uh this is +an example. Well, you know, I'm going to + + align:start position:0% +an example. Well, you know, I'm going to + + + align:start position:0% +an example. Well, you know, I'm going to +skip it so I can get to the end, but + + align:start position:0% +skip it so I can get to the end, but + + + align:start position:0% +skip it so I can get to the end, but +basically games can also help you + + align:start position:0% +basically games can also help you + + + align:start position:0% +basically games can also help you +collect data and compare one scenario + + align:start position:0% +collect data and compare one scenario + + + align:start position:0% +collect data and compare one scenario +versus another and see which are the + + align:start position:0% +versus another and see which are the + + + align:start position:0% +versus another and see which are the +things the aspects of the real world + + align:start position:0% +things the aspects of the real world + + + align:start position:0% +things the aspects of the real world +where people are failing to get + + align:start position:0% +where people are failing to get + + + align:start position:0% +where people are failing to get +something. And so you can target your + + align:start position:0% +something. And so you can target your + + + align:start position:0% +something. And so you can target your +efforts in capacity building, training, + + align:start position:0% +efforts in capacity building, training, + + + align:start position:0% +efforts in capacity building, training, +etc. Um, this is one of the things I + + align:start position:0% +etc. Um, this is one of the things I + + + align:start position:0% +etc. Um, this is one of the things I +will talk to you about. I will want you + + align:start position:0% +will talk to you about. I will want you + + + align:start position:0% +will talk to you about. I will want you +to help us design games or playful + + align:start position:0% +to help us design games or playful + + + align:start position:0% +to help us design games or playful +activities that can help people make + + align:start position:0% +activities that can help people make + + + align:start position:0% +activities that can help people make +their decisions based on forecast as + + align:start position:0% +their decisions based on forecast as + + + align:start position:0% +their decisions based on forecast as +opposed to always doing as if it were + + align:start position:0% +opposed to always doing as if it were + + + align:start position:0% +opposed to always doing as if it were +the normal die. And then if there's a + + align:start position:0% +the normal die. And then if there's a + + + align:start position:0% +the normal die. And then if there's a +flood as the forecast said was more + + align:start position:0% +flood as the forecast said was more + + + align:start position:0% +flood as the forecast said was more +likely and you go h I don't know I + + align:start position:0% +likely and you go h I don't know I + + + align:start position:0% +likely and you go h I don't know I +wasn't prepared which is what happens + + align:start position:0% +wasn't prepared which is what happens + + + align:start position:0% +wasn't prepared which is what happens +quite + + align:start position:0% +quite + + + align:start position:0% +quite +frequently. Uh there are many advantages + + align:start position:0% +frequently. Uh there are many advantages + + + align:start position:0% +frequently. Uh there are many advantages +one is that we get better performance in + + align:start position:0% +one is that we get better performance in + + + align:start position:0% +one is that we get better performance in +terms of outcomes fewer sick people + + align:start position:0% +terms of outcomes fewer sick people + + + align:start position:0% +terms of outcomes fewer sick people +better efficiency so you save more per + + align:start position:0% +better efficiency so you save more per + + + align:start position:0% +better efficiency so you save more per +unit money or equipment or etc. + + align:start position:0% +unit money or equipment or etc. + + + align:start position:0% +unit money or equipment or etc. +Flexibility people can do more if they + + align:start position:0% +Flexibility people can do more if they + + + align:start position:0% +Flexibility people can do more if they +understand the forecast. If you know + + align:start position:0% +understand the forecast. If you know + + + align:start position:0% +understand the forecast. If you know +that Katrina is about to hit your + + align:start position:0% +that Katrina is about to hit your + + + align:start position:0% +that Katrina is about to hit your +village or your city, there's more you + + align:start position:0% +village or your city, there's more you + + + align:start position:0% +village or your city, there's more you +can do in anticipation as opposed to + + align:start position:0% +can do in anticipation as opposed to + + + align:start position:0% +can do in anticipation as opposed to +waiting and once it slams, there's very + + align:start position:0% +waiting and once it slams, there's very + + + align:start position:0% +waiting and once it slams, there's very +few things you can do at that point + + align:start position:0% +few things you can do at that point + + + align:start position:0% +few things you can do at that point +because if you step out of your door, + + align:start position:0% +because if you step out of your door, + + + align:start position:0% +because if you step out of your door, +you're in trouble. Games can create the + + align:start position:0% +you're in trouble. Games can create the + + + align:start position:0% +you're in trouble. Games can create the +appetite through confusion with the + + align:start position:0% +appetite through confusion with the + + + align:start position:0% +appetite through confusion with the +cone. You're like, + + align:start position:0% +cone. You're like, + + + align:start position:0% +cone. You're like, +"Huh?" Right? We deliberately + + align:start position:0% +"Huh?" Right? We deliberately + + + align:start position:0% +"Huh?" Right? We deliberately +create systems that push people to the + + align:start position:0% +create systems that push people to the + + + align:start position:0% +create systems that push people to the +tolerable edge of + + align:start position:0% +tolerable edge of + + + align:start position:0% +tolerable edge of +confusion so that they want to figure + + align:start position:0% +confusion so that they want to figure + + + align:start position:0% +confusion so that they want to figure +out to make sense of what's going on and + + align:start position:0% +out to make sense of what's going on and + + + align:start position:0% +out to make sense of what's going on and +then participants themselves + + align:start position:0% +then participants themselves + + + align:start position:0% +then participants themselves +individually or in conversation with + + align:start position:0% +individually or in conversation with + + + align:start position:0% +individually or in conversation with +peers they go like huh so if I do this + + align:start position:0% +peers they go like huh so if I do this + + + align:start position:0% +peers they go like huh so if I do this +and this happens I'd be better off than + + align:start position:0% +and this happens I'd be better off than + + + align:start position:0% +and this happens I'd be better off than +if I do this other thing. The aha + + align:start position:0% +if I do this other thing. The aha + + + align:start position:0% +if I do this other thing. The aha +moment, the epiphany, the revelation is + + align:start position:0% +moment, the epiphany, the revelation is + + + align:start position:0% +moment, the epiphany, the revelation is +constructed by the players and that has + + align:start position:0% +constructed by the players and that has + + + align:start position:0% +constructed by the players and that has +much more lasting effect than if I give + + align:start position:0% +much more lasting effect than if I give + + + align:start position:0% +much more lasting effect than if I give +you the answer. No one remembers the + + align:start position:0% +you the answer. No one remembers the + + + align:start position:0% +you the answer. No one remembers the +answer if no one was asking the + + align:start position:0% +answer if no one was asking the + + + align:start position:0% +answer if no one was asking the +question. Uh very few examples. + + align:start position:0% +question. Uh very few examples. + + + align:start position:0% +question. Uh very few examples. +Uh these cones are the result of a + + align:start position:0% +Uh these cones are the result of a + + + align:start position:0% +Uh these cones are the result of a +collaboration with uh the word bank + + align:start position:0% +collaboration with uh the word bank + + + align:start position:0% +collaboration with uh the word bank +chief economist for sustainable + + align:start position:0% +chief economist for sustainable + + + align:start position:0% +chief economist for sustainable +development who was trying to explain a + + align:start position:0% +development who was trying to explain a + + + align:start position:0% +development who was trying to explain a +confusing concept called deep + + align:start position:0% +confusing concept called deep + + + align:start position:0% +confusing concept called deep +uncertainty. Janna over there can wave + + align:start position:0% +uncertainty. Janna over there can wave + + + align:start position:0% +uncertainty. Janna over there can wave +Jano she's my partner in game design and + + align:start position:0% +Jano she's my partner in game design and + + + align:start position:0% +Jano she's my partner in game design and +facilitation and life. She had the + + align:start position:0% +facilitation and life. She had the + + + align:start position:0% +facilitation and life. She had the +brilliant idea of taking our cone had + + align:start position:0% +brilliant idea of taking our cone had + + + align:start position:0% +brilliant idea of taking our cone had +surgery our sorry our cat had surgery + + align:start position:0% +surgery our sorry our cat had surgery + + + align:start position:0% +surgery our sorry our cat had surgery +and she thought how about using the the + + align:start position:0% +and she thought how about using the the + + + align:start position:0% +and she thought how about using the the +cone of shame you know for for the + + align:start position:0% +cone of shame you know for for the + + + align:start position:0% +cone of shame you know for for the +creature not to not to lick its surgery + + align:start position:0% +creature not to not to lick its surgery + + + align:start position:0% +creature not to not to lick its surgery +to say how about using that for + + align:start position:0% +to say how about using that for + + + align:start position:0% +to say how about using that for +depicting this uncertainty. Now we had + + align:start position:0% +depicting this uncertainty. Now we had + + + align:start position:0% +depicting this uncertainty. Now we had +students tossing each one of those cones + + align:start position:0% +students tossing each one of those cones + + + align:start position:0% +students tossing each one of those cones +a 100 times to see the probability + + align:start position:0% +a 100 times to see the probability + + + align:start position:0% +a 100 times to see the probability +distribution with and without spin and + + align:start position:0% +distribution with and without spin and + + + align:start position:0% +distribution with and without spin and +augmenting the gap between what you + + align:start position:0% +augmenting the gap between what you + + + align:start position:0% +augmenting the gap between what you +think will happen and what actually + + align:start position:0% +think will happen and what actually + + + align:start position:0% +think will happen and what actually +happens. Uh a few other cases. This is + + align:start position:0% +happens. Uh a few other cases. This is + + + align:start position:0% +happens. Uh a few other cases. This is +from uh Hanoi University of Science and + + align:start position:0% +from uh Hanoi University of Science and + + + align:start position:0% +from uh Hanoi University of Science and +Technology. This was with 350 students + + align:start position:0% +Technology. This was with 350 students + + + align:start position:0% +Technology. This was with 350 students +uh playing a game on Denga. It's like a + + align:start position:0% +uh playing a game on Denga. It's like a + + + align:start position:0% +uh playing a game on Denga. It's like a +rock paper scissors where three players + + align:start position:0% +rock paper scissors where three players + + + align:start position:0% +rock paper scissors where three players +are mosquitoes and they can either bite + + align:start position:0% +are mosquitoes and they can either bite + + + align:start position:0% +are mosquitoes and they can either bite +or with your blood lay eggs and other + + align:start position:0% +or with your blood lay eggs and other + + + align:start position:0% +or with your blood lay eggs and other +players are humans and they can either + + align:start position:0% +players are humans and they can either + + + align:start position:0% +players are humans and they can either +protect from biting or attack the + + align:start position:0% +protect from biting or attack the + + + align:start position:0% +protect from biting or attack the +breeding grounds. This was designed by + + align:start position:0% +breeding grounds. This was designed by + + + align:start position:0% +breeding grounds. This was designed by +students at Parson's collaborating game + + align:start position:0% +students at Parson's collaborating game + + + align:start position:0% +students at Parson's collaborating game +design. students at Parsons and + + align:start position:0% +design. students at Parsons and + + + align:start position:0% +design. students at Parsons and +professors collaborating with EL + + align:start position:0% +professors collaborating with EL + + + align:start position:0% +professors collaborating with EL +students. Uh this one is + + align:start position:0% +students. Uh this one is + + + align:start position:0% +students. Uh this one is +a publication from + + align:start position:0% +a publication from + + + align:start position:0% +a publication from +NASA. Doesn't get more NASA than a + + align:start position:0% +NASA. Doesn't get more NASA than a + + + align:start position:0% +NASA. Doesn't get more NASA than a +rocket launch. But if you look here, it + + align:start position:0% +rocket launch. But if you look here, it + + + align:start position:0% +rocket launch. But if you look here, it +says Erin Coughlin, former intern, now + + align:start position:0% +says Erin Coughlin, former intern, now + + + align:start position:0% +says Erin Coughlin, former intern, now +staff in my team h and the Red Cross + + align:start position:0% +staff in my team h and the Red Cross + + + align:start position:0% +staff in my team h and the Red Cross +Recess Climate Center project. You go to + + align:start position:0% +Recess Climate Center project. You go to + + + align:start position:0% +Recess Climate Center project. You go to +page 47 and you see Muno. Monu is a + + align:start position:0% +page 47 and you see Muno. Monu is a + + + align:start position:0% +page 47 and you see Muno. Monu is a +volunteer of the Zambian Red Cross from + + align:start position:0% +volunteer of the Zambian Red Cross from + + + align:start position:0% +volunteer of the Zambian Red Cross from +the village of + + align:start position:0% +the village of + + + align:start position:0% +the village of +Kazungula in western Zambia on the + + align:start position:0% +Kazungula in western Zambia on the + + + align:start position:0% +Kazungula in western Zambia on the +Zambzi + + align:start position:0% +Zambzi + + + align:start position:0% +Zambzi +River. I mean there's not much + + align:start position:0% +River. I mean there's not much + + + align:start position:0% +River. I mean there's not much +electricity or NASAness in Kazungula, + + align:start position:0% +electricity or NASAness in Kazungula, + + + align:start position:0% +electricity or NASAness in Kazungula, +but he was trained as a facilitator for + + align:start position:0% +but he was trained as a facilitator for + + + align:start position:0% +but he was trained as a facilitator for +a game where with cards and dice there's + + align:start position:0% +a game where with cards and dice there's + + + align:start position:0% +a game where with cards and dice there's +rain that happens over there. So her cup + + align:start position:0% +rain that happens over there. So her cup + + + align:start position:0% +rain that happens over there. So her cup +gets some water and then from her cup + + align:start position:0% +gets some water and then from her cup + + + align:start position:0% +gets some water and then from her cup +she passes the water to the person next + + align:start position:0% +she passes the water to the person next + + + align:start position:0% +she passes the water to the person next +to her like representing the upstream + + align:start position:0% +to her like representing the upstream + + + align:start position:0% +to her like representing the upstream +going downstream. She can get more water + + align:start position:0% +going downstream. She can get more water + + + align:start position:0% +going downstream. She can get more water +or not and it keeps going until maybe he + + align:start position:0% +or not and it keeps going until maybe he + + + align:start position:0% +or not and it keeps going until maybe he +gets water to overflow his cup. He's in + + align:start position:0% +gets water to overflow his cup. He's in + + + align:start position:0% +gets water to overflow his cup. He's in +trouble unless he takes some action + + align:start position:0% +trouble unless he takes some action + + + align:start position:0% +trouble unless he takes some action +ahead of time. And the game we're + + align:start position:0% +ahead of time. And the game we're + + + align:start position:0% +ahead of time. And the game we're +designing is not only with cups and and + + align:start position:0% +designing is not only with cups and and + + + align:start position:0% +designing is not only with cups and and +to mimic the upstream downstream, but + + align:start position:0% +to mimic the upstream downstream, but + + + align:start position:0% +to mimic the upstream downstream, but +we're also making a digital game where + + align:start position:0% +we're also making a digital game where + + + align:start position:0% +we're also making a digital game where +people actually monitor river levels and + + align:start position:0% +people actually monitor river levels and + + + align:start position:0% +people actually monitor river levels and +they make predictions. They make uh bets + + align:start position:0% +they make predictions. They make uh bets + + + align:start position:0% +they make predictions. They make uh bets +as to what the river level will be in + + align:start position:0% +as to what the river level will be in + + + align:start position:0% +as to what the river level will be in +two days or so. And then the winner wins + + align:start position:0% +two days or so. And then the winner wins + + + align:start position:0% +two days or so. And then the winner wins +points, but they can use points to buy + + align:start position:0% +points, but they can use points to buy + + + align:start position:0% +points, but they can use points to buy +information from upstream. And then + + align:start position:0% +information from upstream. And then + + + align:start position:0% +information from upstream. And then +we're with that data, we're developing a + + align:start position:0% +we're with that data, we're developing a + + + align:start position:0% +we're with that data, we're developing a +hydraological model that can help us + + align:start position:0% +hydraological model that can help us + + + align:start position:0% +hydraological model that can help us +better know what is going down the + + align:start position:0% +better know what is going down the + + + align:start position:0% +better know what is going down the +stream and are we going to have more + + align:start position:0% +stream and are we going to have more + + + align:start position:0% +stream and are we going to have more +flood + + align:start position:0% +flood + + + align:start position:0% +flood +trouble. As you can imagine, it's + + align:start position:0% +trouble. As you can imagine, it's + + + align:start position:0% +trouble. As you can imagine, it's +awesome to have NASA report on some + + align:start position:0% +awesome to have NASA report on some + + + align:start position:0% +awesome to have NASA report on some +little project in uh western Zambia in + + align:start position:0% +little project in uh western Zambia in + + + align:start position:0% +little project in uh western Zambia in +part because we know that we can partner + + align:start position:0% +part because we know that we can partner + + + align:start position:0% +part because we know that we can partner +this on the field gamebased data + + align:start position:0% +this on the field gamebased data + + + align:start position:0% +this on the field gamebased data +collection with satellite image for + + align:start position:0% +collection with satellite image for + + + align:start position:0% +collection with satellite image for +ground truthing and so on. + + align:start position:0% +ground truthing and so on. + + + align:start position:0% +ground truthing and so on. +Um this + + align:start position:0% +Um this + + + align:start position:0% +Um this +one because we are being recorded I will + + align:start position:0% +one because we are being recorded I will + + + align:start position:0% +one because we are being recorded I will +not disclose the full story but in short + + align:start position:0% +not disclose the full story but in short + + + align:start position:0% +not disclose the full story but in short +we play the game h that had the same + + align:start position:0% +we play the game h that had the same + + + align:start position:0% +we play the game h that had the same +story you play with a six-sided die you + + align:start position:0% +story you play with a six-sided die you + + + align:start position:0% +story you play with a six-sided die you +know your probabilities it was being + + align:start position:0% +know your probabilities it was being + + + align:start position:0% +know your probabilities it was being +played with the top level climate + + align:start position:0% +played with the top level climate + + + align:start position:0% +played with the top level climate +scientists in this planet and as you can + + align:start position:0% +scientists in this planet and as you can + + + align:start position:0% +scientists in this planet and as you can +see on the left there's all sorts of + + align:start position:0% +see on the left there's all sorts of + + + align:start position:0% +see on the left there's all sorts of +calculations with probability + + align:start position:0% +calculations with probability + + + align:start position:0% +calculations with probability +distributions and cost benefits and so + + align:start position:0% +distributions and cost benefits and so + + + align:start position:0% +distributions and cost benefits and so +on. Then we changed the probabilities on + + align:start position:0% +on. Then we changed the probabilities on + + + align:start position:0% +on. Then we changed the probabilities on +them and then we gave them that just + + align:start position:0% +them and then we gave them that just + + + align:start position:0% +them and then we gave them that just +like you were saying what is that what + + align:start position:0% +like you were saying what is that what + + + align:start position:0% +like you were saying what is that what +are you going to use we just gave them + + align:start position:0% +are you going to use we just gave them + + + align:start position:0% +are you going to use we just gave them +that graph and the caption and some of + + align:start position:0% +that graph and the caption and some of + + + align:start position:0% +that graph and the caption and some of +them were saying but wait a second why + + align:start position:0% +them were saying but wait a second why + + + align:start position:0% +them were saying but wait a second why +are you giving me this information it's + + align:start position:0% +are you giving me this information it's + + + align:start position:0% +are you giving me this information it's +completely useless in the context of my + + align:start position:0% +completely useless in the context of my + + + align:start position:0% +completely useless in the context of my +decision situation and then we told them + + align:start position:0% +decision situation and then we told them + + + align:start position:0% +decision situation and then we told them +this is the information that you + + align:start position:0% +this is the information that you + + + align:start position:0% +this is the information that you +yourselves produced in the summary for + + align:start position:0% +yourselves produced in the summary for + + + align:start position:0% +yourselves produced in the summary for +policy makers of climate science stuff + + align:start position:0% +policy makers of climate science stuff + + + align:start position:0% +policy makers of climate science stuff +and they became fully aware of the need + + align:start position:0% +and they became fully aware of the need + + + align:start position:0% +and they became fully aware of the need +for them to improve the way they + + align:start position:0% +for them to improve the way they + + + align:start position:0% +for them to improve the way they +communicate climate + + align:start position:0% +communicate climate + + + align:start position:0% +communicate climate +science. + + align:start position:0% +science. + + + align:start position:0% +science. +Uh this uh you may recognize that dude. + + align:start position:0% +Uh this uh you may recognize that dude. + + + align:start position:0% +Uh this uh you may recognize that dude. +I think it's the last time I wore a + + align:start position:0% +I think it's the last time I wore a + + + align:start position:0% +I think it's the last time I wore a +necktie at the White + + align:start position:0% +necktie at the White + + + align:start position:0% +necktie at the White +House. I was given five minutes. I + + align:start position:0% +House. I was given five minutes. I + + + align:start position:0% +House. I was given five minutes. I +begged for seven. Seven minutes given + + align:start position:0% +begged for seven. Seven minutes given + + + align:start position:0% +begged for seven. Seven minutes given +preceded by extensive PowerPoint + + align:start position:0% +preceded by extensive PowerPoint + + + align:start position:0% +preceded by extensive PowerPoint +presentations or other forms of + + align:start position:0% +presentations or other forms of + + + align:start position:0% +presentations or other forms of +unidirectional. So, I had an audience + + align:start position:0% +unidirectional. So, I had an audience + + + align:start position:0% +unidirectional. So, I had an audience +that had a brain wave activity declining + + align:start position:0% +that had a brain wave activity declining + + + align:start position:0% +that had a brain wave activity declining +and I said, "Hello, my name is Pablo and + + align:start position:0% +and I said, "Hello, my name is Pablo and + + + align:start position:0% +and I said, "Hello, my name is Pablo and +this is not a Frisbee. It's a hurricane. + + align:start position:0% +this is not a Frisbee. It's a hurricane. + + + align:start position:0% +this is not a Frisbee. It's a hurricane. +Everybody stand + + align:start position:0% +Everybody stand + + + align:start position:0% +Everybody stand +up." And people were somewhat confused. + + align:start position:0% +up." And people were somewhat confused. + + + align:start position:0% +up." And people were somewhat confused. +Some were standing. Others were + + align:start position:0% +Some were standing. Others were + + + align:start position:0% +Some were standing. Others were +distracted and they saw people standing, + + align:start position:0% +distracted and they saw people standing, + + + align:start position:0% +distracted and they saw people standing, +so they stood. And I said, "Okay, I'm + + align:start position:0% +so they stood. And I said, "Okay, I'm + + + align:start position:0% +so they stood. And I said, "Okay, I'm +going to throw this Frisbee in some + + align:start position:0% +going to throw this Frisbee in some + + + align:start position:0% +going to throw this Frisbee in some +direction. It's a hurricane. If it hits + + align:start position:0% +direction. It's a hurricane. If it hits + + + align:start position:0% +direction. It's a hurricane. If it hits +you in the chest, it's trouble. You're + + align:start position:0% +you in the chest, it's trouble. You're + + + align:start position:0% +you in the chest, it's trouble. You're +suffering." Now, if you sit down, it + + align:start position:0% +suffering." Now, if you sit down, it + + + align:start position:0% +suffering." Now, if you sit down, it +will fly above your head. No problem. + + align:start position:0% +will fly above your head. No problem. + + + align:start position:0% +will fly above your head. No problem. +It's like evacuation. But if you sit + + align:start position:0% +It's like evacuation. But if you sit + + + align:start position:0% +It's like evacuation. But if you sit +down and evacuate and the hurricane goes + + align:start position:0% +down and evacuate and the hurricane goes + + + align:start position:0% +down and evacuate and the hurricane goes +in some other direction, someone may + + align:start position:0% +in some other direction, someone may + + + align:start position:0% +in some other direction, someone may +steal your refrigerator, right? You're + + align:start position:0% +steal your refrigerator, right? You're + + + align:start position:0% +steal your refrigerator, right? You're +you're doing the wrong thing. So where + + align:start position:0% +you're doing the wrong thing. So where + + + align:start position:0% +you're doing the wrong thing. So where +it will go will be determined by these + + align:start position:0% +it will go will be determined by these + + + align:start position:0% +it will go will be determined by these +two dice. So you either stay standing or + + align:start position:0% +two dice. So you either stay standing or + + + align:start position:0% +two dice. So you either stay standing or +or sit down to evacuate. Okay? And I th + + align:start position:0% +or sit down to evacuate. Okay? And I th + + + align:start position:0% +or sit down to evacuate. Okay? And I th +I throw the things and I look and I + + align:start position:0% +I throw the things and I look and I + + + align:start position:0% +I throw the things and I look and I +throw in this direction. Then in this + + align:start position:0% +throw in this direction. Then in this + + + align:start position:0% +throw in this direction. Then in this +direction, people were being hit. There + + align:start position:0% +direction, people were being hit. There + + + align:start position:0% +direction, people were being hit. There +was huge confusion. No one understood + + align:start position:0% +was huge confusion. No one understood + + + align:start position:0% +was huge confusion. No one understood +what was going on. And then someone got + + align:start position:0% +what was going on. And then someone got + + + align:start position:0% +what was going on. And then someone got +it. Double one I throw over here. Double + + align:start position:0% +it. Double one I throw over here. Double + + + align:start position:0% +it. Double one I throw over here. Double +six I throw over here. + + align:start position:0% +six I throw over here. + + + align:start position:0% +six I throw over here. +interpolate. So, someone figured it out, + + align:start position:0% +interpolate. So, someone figured it out, + + + align:start position:0% +interpolate. So, someone figured it out, +said, "Oh, and now I need to go in that + + align:start position:0% +said, "Oh, and now I need to go in that + + + align:start position:0% +said, "Oh, and now I need to go in that +direction." Everybody sat down and I + + align:start position:0% +direction." Everybody sat down and I + + + align:start position:0% +direction." Everybody sat down and I +threw the Frisbee and it flew elegantly + + align:start position:0% +threw the Frisbee and it flew elegantly + + + align:start position:0% +threw the Frisbee and it flew elegantly +until it hit the wall of the White + + align:start position:0% +until it hit the wall of the White + + + align:start position:0% +until it hit the wall of the White +House. And then I said, "Well, you know, + + align:start position:0% +House. And then I said, "Well, you know, + + + align:start position:0% +House. And then I said, "Well, you know, +climate science can give us this. Think + + align:start position:0% +climate science can give us this. Think + + + align:start position:0% +climate science can give us this. Think +Katrina. Think all that we could do. + + align:start position:0% +Katrina. Think all that we could do. + + + align:start position:0% +Katrina. Think all that we could do. +We're here to help. Thank you." And that + + align:start position:0% +We're here to help. Thank you." And that + + + align:start position:0% +We're here to help. Thank you." And that +game was memorable. It opened doors and + + align:start position:0% +game was memorable. It opened doors and + + + align:start position:0% +game was memorable. It opened doors and +it created awareness of the value of + + align:start position:0% +it created awareness of the value of + + + align:start position:0% +it created awareness of the value of +linking climate science with decisions + + align:start position:0% +linking climate science with decisions + + + align:start position:0% +linking climate science with decisions +at the humanitarian sector, at the + + align:start position:0% +at the humanitarian sector, at the + + + align:start position:0% +at the humanitarian sector, at the +government sector and beyond. So, uh, + + align:start position:0% +government sector and beyond. So, uh, + + + align:start position:0% +government sector and beyond. So, uh, +gameplay beats PowerPoint in a million + + align:start position:0% +gameplay beats PowerPoint in a million + + + align:start position:0% +gameplay beats PowerPoint in a million +ways. For me, as someone who has to help + + align:start position:0% +ways. For me, as someone who has to help + + + align:start position:0% +ways. For me, as someone who has to help +others take actions that save lives, I'd + + align:start position:0% +others take actions that save lives, I'd + + + align:start position:0% +others take actions that save lives, I'd +say first of all, there's active + + align:start position:0% +say first of all, there's active + + + align:start position:0% +say first of all, there's active +learning. When you were playing and you + + align:start position:0% +learning. When you were playing and you + + + align:start position:0% +learning. When you were playing and you +were confronted with that fact, you were + + align:start position:0% +were confronted with that fact, you were + + + align:start position:0% +were confronted with that fact, you were +saying, "What is that? What does it + + align:start position:0% +saying, "What is that? What does it + + + align:start position:0% +saying, "What is that? What does it +mean? And what should I do about it?" + + align:start position:0% +mean? And what should I do about it?" + + + align:start position:0% +mean? And what should I do about it?" +It's about action and there's plenty of + + align:start position:0% +It's about action and there's plenty of + + + align:start position:0% +It's about action and there's plenty of +peer-to-peer. No, but look, if it's 50% + + align:start position:0% +peer-to-peer. No, but look, if it's 50% + + + align:start position:0% +peer-to-peer. No, but look, if it's 50% +and people learn from each other, plenty + + align:start position:0% +and people learn from each other, plenty + + + align:start position:0% +and people learn from each other, plenty +of aha moments. There's also it's fun, + + align:start position:0% +of aha moments. There's also it's fun, + + + align:start position:0% +of aha moments. There's also it's fun, +but it's serious. And the fact that it's + + align:start position:0% +but it's serious. And the fact that it's + + + align:start position:0% +but it's serious. And the fact that it's +fun is important. Neuroscientists, + + align:start position:0% +fun is important. Neuroscientists, + + + align:start position:0% +fun is important. Neuroscientists, +including some in this building, I think + + align:start position:0% +including some in this building, I think + + + align:start position:0% +including some in this building, I think +Satra works here, + + align:start position:0% +Satra works here, + + + align:start position:0% +Satra works here, +um, have evidence that if you're + + align:start position:0% +um, have evidence that if you're + + + align:start position:0% +um, have evidence that if you're +emotionally engaged, your learning goes + + align:start position:0% +emotionally engaged, your learning goes + + + align:start position:0% +emotionally engaged, your learning goes +deeper and lasts + + align:start position:0% +deeper and lasts + + + align:start position:0% +deeper and lasts +longer. Uh, there is also the ability to + + align:start position:0% +longer. Uh, there is also the ability to + + + align:start position:0% +longer. Uh, there is also the ability to +collect data. I didn't go into it, but + + align:start position:0% +collect data. I didn't go into it, but + + + align:start position:0% +collect data. I didn't go into it, but +that's one of the things I'd be keen on + + align:start position:0% +that's one of the things I'd be keen on + + + align:start position:0% +that's one of the things I'd be keen on +using with you if you are able to make a + + align:start position:0% +using with you if you are able to make a + + + align:start position:0% +using with you if you are able to make a +digital game that can collect data and + + align:start position:0% +digital game that can collect data and + + + align:start position:0% +digital game that can collect data and +help us understand what do people know, + + align:start position:0% +help us understand what do people know, + + + align:start position:0% +help us understand what do people know, +what do people think, what do people + + align:start position:0% +what do people think, what do people + + + align:start position:0% +what do people think, what do people +want, and then we can use it as an + + align:start position:0% +want, and then we can use it as an + + + align:start position:0% +want, and then we can use it as an +optimization platform. How much should + + align:start position:0% +optimization platform. How much should + + + align:start position:0% +optimization platform. How much should +we do? How many people should stand up + + align:start position:0% +we do? How many people should stand up + + + align:start position:0% +we do? How many people should stand up +next time we have that forecast? We try + + align:start position:0% +next time we have that forecast? We try + + + align:start position:0% +next time we have that forecast? We try +we we it's like a Monte Carlo + + align:start position:0% +we we it's like a Monte Carlo + + + align:start position:0% +we we it's like a Monte Carlo +simulation, right? you do things many + + align:start position:0% +simulation, right? you do things many + + + align:start position:0% +simulation, right? you do things many +times and figure out what are the things + + align:start position:0% +times and figure out what are the things + + + align:start position:0% +times and figure out what are the things +that you call optimal based on objective + + align:start position:0% +that you call optimal based on objective + + + align:start position:0% +that you call optimal based on objective +or subjective metrics. Uh that's the + + align:start position:0% +or subjective metrics. Uh that's the + + + align:start position:0% +or subjective metrics. Uh that's the +website for my team climate + + align:start position:0% +website for my team climate + + + align:start position:0% +website for my team climate +centric.org. Note the British + + align:start position:0% +centric.org. Note the British + + + align:start position:0% +centric.org. Note the British +spelling. This is at the core why we + + align:start position:0% +spelling. This is at the core why we + + + align:start position:0% +spelling. This is at the core why we +love games. There's an experiential + + align:start position:0% +love games. There's an experiential + + + align:start position:0% +love games. There's an experiential +learning that's a from our conversation + + align:start position:0% +learning that's a from our conversation + + + align:start position:0% +learning that's a from our conversation +with your colleagues at the Lincoln lab. + + align:start position:0% +with your colleagues at the Lincoln lab. + + + align:start position:0% +with your colleagues at the Lincoln lab. +You want to do things, reflect on what + + align:start position:0% +You want to do things, reflect on what + + + align:start position:0% +You want to do things, reflect on what +happened, form abstract concepts, maybe + + align:start position:0% +happened, form abstract concepts, maybe + + + align:start position:0% +happened, form abstract concepts, maybe +I should do this or that, test it, and + + align:start position:0% +I should do this or that, test it, and + + + align:start position:0% +I should do this or that, test it, and +do again in a better way. And it's much + + align:start position:0% +do again in a better way. And it's much + + + align:start position:0% +do again in a better way. And it's much +safer to do this in gameplay than to do + + align:start position:0% +safer to do this in gameplay than to do + + + align:start position:0% +safer to do this in gameplay than to do +it in the real world where if you fail, + + align:start position:0% +it in the real world where if you fail, + + + align:start position:0% +it in the real world where if you fail, +you can fail soundly. These are some of + + align:start position:0% +you can fail soundly. These are some of + + + align:start position:0% +you can fail soundly. These are some of +the partners we have worked with + + align:start position:0% +the partners we have worked with + + + align:start position:0% +the partners we have worked with +including UN system, academic + + align:start position:0% +including UN system, academic + + + align:start position:0% +including UN system, academic +organizations, Rockefeller Foundation + + align:start position:0% +organizations, Rockefeller Foundation + + + align:start position:0% +organizations, Rockefeller Foundation +and many other partners like Oxam + + align:start position:0% +and many other partners like Oxam + + + align:start position:0% +and many other partners like Oxam +America and so on. It's been delightful. + + align:start position:0% +America and so on. It's been delightful. + + + align:start position:0% +America and so on. It's been delightful. +We have severe shortage of human + + align:start position:0% +We have severe shortage of human + + + align:start position:0% +We have severe shortage of human +capacity to make this happen. We have + + align:start position:0% +capacity to make this happen. We have + + + align:start position:0% +capacity to make this happen. We have +Jano who will likely come h as a + + align:start position:0% +Jano who will likely come h as a + + + align:start position:0% +Jano who will likely come h as a +resource person to interact with you uh + + align:start position:0% +resource person to interact with you uh + + + align:start position:0% +resource person to interact with you uh +when I'm and traveling which will be a + + align:start position:0% +when I'm and traveling which will be a + + + align:start position:0% +when I'm and traveling which will be a +lot over the coming months. There may be + + align:start position:0% +lot over the coming months. There may be + + + align:start position:0% +lot over the coming months. There may be +other colleagues who live in New York + + align:start position:0% +other colleagues who live in New York + + + align:start position:0% +other colleagues who live in New York +who may come. We also have Willow. + + align:start position:0% +who may come. We also have Willow. + + + align:start position:0% +who may come. We also have Willow. +Willow, would you like to wave your + + align:start position:0% +Willow, would you like to wave your + + + align:start position:0% +Willow, would you like to wave your +hands? Willow is very likely to become a + + align:start position:0% +hands? Willow is very likely to become a + + + align:start position:0% +hands? Willow is very likely to become a +consultant for my team going to Nairobi + + align:start position:0% +consultant for my team going to Nairobi + + + align:start position:0% +consultant for my team going to Nairobi +and help uh people use digital devices + + align:start position:0% +and help uh people use digital devices + + + align:start position:0% +and help uh people use digital devices +to map risks at the community level. + + align:start position:0% +to map risks at the community level. + + + align:start position:0% +to map risks at the community level. +Maybe we there's a way to infuse it with + + align:start position:0% +Maybe we there's a way to infuse it with + + + align:start position:0% +Maybe we there's a way to infuse it with +games. She already developed games for + + align:start position:0% +games. She already developed games for + + + align:start position:0% +games. She already developed games for +Tanzanian uh communities. So in short, I + + align:start position:0% +Tanzanian uh communities. So in short, I + + + align:start position:0% +Tanzanian uh communities. So in short, I +wish you all the best learning a lot + + align:start position:0% +wish you all the best learning a lot + + + align:start position:0% +wish you all the best learning a lot +from these guys doing a lot based on + + align:start position:0% +from these guys doing a lot based on + + + align:start position:0% +from these guys doing a lot based on +what you learn and your own motivations. + + align:start position:0% +what you learn and your own motivations. + + + align:start position:0% +what you learn and your own motivations. +And whether you like it or not, project + + align:start position:0% +And whether you like it or not, project + + + align:start position:0% +And whether you like it or not, project +4 will involve doing something for us. + + align:start position:0% +4 will involve doing something for us. + + + align:start position:0% +4 will involve doing something for us. +Thank you in advance for accepting those + + align:start position:0% +Thank you in advance for accepting those + + + align:start position:0% +Thank you in advance for accepting those +rules. And there shall be more. Thank + + align:start position:0% +rules. And there shall be more. Thank + + + align:start position:0% +rules. And there shall be more. Thank +you very much. Oh, and by the way, I + + align:start position:0% +you very much. Oh, and by the way, I + + + align:start position:0% +you very much. Oh, and by the way, I +will leave this uh with you guys. Uh + + align:start position:0% +will leave this uh with you guys. Uh + + + align:start position:0% +will leave this uh with you guys. Uh +it's our publication shared uh endeavor + + align:start position:0% +it's our publication shared uh endeavor + + + align:start position:0% +it's our publication shared uh endeavor +of my Red Cross team and the Boston + + align:start position:0% +of my Red Cross team and the Boston + + + align:start position:0% +of my Red Cross team and the Boston +University Part D Center. It's called + + align:start position:0% +University Part D Center. It's called + + + align:start position:0% +University Part D Center. It's called +Games for a New Climate: Experiencing + + align:start position:0% +Games for a New Climate: Experiencing + + + align:start position:0% +Games for a New Climate: Experiencing +the Complexity of Future Risks. I + + align:start position:0% +the Complexity of Future Risks. I + + + align:start position:0% +the Complexity of Future Risks. I +promise you it's fun to read. Uh and + + align:start position:0% +promise you it's fun to read. Uh and + + + align:start position:0% +promise you it's fun to read. Uh and +it's available online for free as PDF. + + align:start position:0% +it's available online for free as PDF. + + + align:start position:0% +it's available online for free as PDF. +Um I'm going to talk a little bit about + + align:start position:0% +Um I'm going to talk a little bit about + + + align:start position:0% +Um I'm going to talk a little bit about +game engines. And before I do, I just + + align:start position:0% +game engines. And before I do, I just + + + align:start position:0% +game engines. And before I do, I just +want to think a little bit about one of + + align:start position:0% +want to think a little bit about one of + + + align:start position:0% +want to think a little bit about one of +the things that Pablo was saying is + + align:start position:0% +the things that Pablo was saying is + + + align:start position:0% +the things that Pablo was saying is +about one of the things that a game does + + align:start position:0% +about one of the things that a game does + + + align:start position:0% +about one of the things that a game does +is it forces you to look at what + + align:start position:0% +is it forces you to look at what + + + align:start position:0% +is it forces you to look at what +happened, sort of say, huh, figure out + + align:start position:0% +happened, sort of say, huh, figure out + + + align:start position:0% +happened, sort of say, huh, figure out +why did that happen and then you try to + + align:start position:0% +why did that happen and then you try to + + + align:start position:0% +why did that happen and then you try to +fix it. Um, and that's actually one of + + align:start position:0% +fix it. Um, and that's actually one of + + + align:start position:0% +fix it. Um, and that's actually one of +the things I think is very much like + + align:start position:0% +the things I think is very much like + + + align:start position:0% +the things I think is very much like +programming. Um, if you're trying to + + align:start position:0% +programming. Um, if you're trying to + + + align:start position:0% +programming. Um, if you're trying to +write code and something goes wrong, + + align:start position:0% +write code and something goes wrong, + + + align:start position:0% +write code and something goes wrong, +often that's what the process of + + align:start position:0% +often that's what the process of + + + align:start position:0% +often that's what the process of +debugging is like. You go, why did the + + align:start position:0% +debugging is like. You go, why did the + + + align:start position:0% +debugging is like. You go, why did the +screen flip upside down? That still + + align:start position:0% +screen flip upside down? That still + + + align:start position:0% +screen flip upside down? That still +makes no sense. And then you have the + + align:start position:0% +makes no sense. And then you have the + + + align:start position:0% +makes no sense. And then you have the +aha moment and you can go and fix it. + + align:start position:0% +aha moment and you can go and fix it. + + + align:start position:0% +aha moment and you can go and fix it. +Um, turns out that making software is a + + align:start position:0% +Um, turns out that making software is a + + + align:start position:0% +Um, turns out that making software is a +lot like playing a game. + + align:start position:0% +lot like playing a game. + + + align:start position:0% +lot like playing a game. +So anyway, uh we're going to talk about + + align:start position:0% +So anyway, uh we're going to talk about + + + align:start position:0% +So anyway, uh we're going to talk about +game engine selection because one of + + align:start position:0% +game engine selection because one of + + + align:start position:0% +game engine selection because one of +your early tasks will be to sort of try + + align:start position:0% +your early tasks will be to sort of try + + + align:start position:0% +your early tasks will be to sort of try +out a game engine. We're not going to be + + align:start position:0% +out a game engine. We're not going to be + + + align:start position:0% +out a game engine. We're not going to be +using a game engine for the first game + + align:start position:0% +using a game engine for the first game + + + align:start position:0% +using a game engine for the first game +project, but we want you to be sort of + + align:start position:0% +project, but we want you to be sort of + + + align:start position:0% +project, but we want you to be sort of +ready for it when it comes to project + + align:start position:0% + + + + align:start position:0% + +two. Now, the first thing to realize is + + align:start position:0% +two. Now, the first thing to realize is + + + align:start position:0% +two. Now, the first thing to realize is +that um digital games are basically they + + align:start position:0% +that um digital games are basically they + + + align:start position:0% +that um digital games are basically they +are a software project. They share a lot + + align:start position:0% +are a software project. They share a lot + + + align:start position:0% +are a software project. They share a lot +of things in common with software in + + align:start position:0% +of things in common with software in + + + align:start position:0% +of things in common with software in +general. You're going to have a UI that + + align:start position:0% +general. You're going to have a UI that + + + align:start position:0% +general. You're going to have a UI that +your user has to interact with. There's + + align:start position:0% +your user has to interact with. There's + + + align:start position:0% +your user has to interact with. There's +going to be something going on in the + + align:start position:0% +going to be something going on in the + + + align:start position:0% +going to be something going on in the +back end. Maybe it's for, you know, + + align:start position:0% +back end. Maybe it's for, you know, + + + align:start position:0% +back end. Maybe it's for, you know, +commercial business software. It might + + align:start position:0% +commercial business software. It might + + + align:start position:0% +commercial business software. It might +be a database or something. Um, there's + + align:start position:0% +be a database or something. Um, there's + + + align:start position:0% +be a database or something. Um, there's +probably going to be either a design + + align:start position:0% +probably going to be either a design + + + align:start position:0% +probably going to be either a design +you're working from or you're making it + + align:start position:0% +you're working from or you're making it + + + align:start position:0% +you're working from or you're making it +up or maybe you've got a customer who + + align:start position:0% +up or maybe you've got a customer who + + + align:start position:0% +up or maybe you've got a customer who +cares what's going on. You've got + + align:start position:0% +cares what's going on. You've got + + + align:start position:0% +cares what's going on. You've got +features, you've got bugs, we got task + + align:start position:0% +features, you've got bugs, we got task + + + align:start position:0% +features, you've got bugs, we got task +lists, all the same sort of management + + align:start position:0% +lists, all the same sort of management + + + align:start position:0% +lists, all the same sort of management +management things that happen happen on + + align:start position:0% +management things that happen happen on + + + align:start position:0% +management things that happen happen on +software projects and game projects the + + align:start position:0% +software projects and game projects the + + + align:start position:0% +software projects and game projects the +same way. There's a little bit of a + + align:start position:0% +same way. There's a little bit of a + + + align:start position:0% +same way. There's a little bit of a +difference though. Games are a little + + align:start position:0% +difference though. Games are a little + + + align:start position:0% +difference though. Games are a little +bit harder in some ways and easier in + + align:start position:0% +bit harder in some ways and easier in + + + align:start position:0% +bit harder in some ways and easier in +others, but we're going to talk about + + align:start position:0% +others, but we're going to talk about + + + align:start position:0% +others, but we're going to talk about +ways that are harder because that's more + + align:start position:0% +ways that are harder because that's more + + + align:start position:0% +ways that are harder because that's more +interesting. Um, the thing that happens + + align:start position:0% +interesting. Um, the thing that happens + + + align:start position:0% +interesting. Um, the thing that happens +with most business software or even + + align:start position:0% +with most business software or even + + + align:start position:0% +with most business software or even +something like Photoshop. Have you used + + align:start position:0% +something like Photoshop. Have you used + + + align:start position:0% +something like Photoshop. Have you used +Photoshop? Excellent. Photoshop is one + + align:start position:0% +Photoshop? Excellent. Photoshop is one + + + align:start position:0% +Photoshop? Excellent. Photoshop is one +of those software packages that a lot of + + align:start position:0% +of those software packages that a lot of + + + align:start position:0% +of those software packages that a lot of +people like to take classes in Photoshop + + align:start position:0% +people like to take classes in Photoshop + + + align:start position:0% +people like to take classes in Photoshop +before they get started. Um, if you sat + + align:start position:0% +before they get started. Um, if you sat + + + align:start position:0% +before they get started. Um, if you sat +down to Photoshop, you probably didn't + + align:start position:0% +down to Photoshop, you probably didn't + + + align:start position:0% +down to Photoshop, you probably didn't +think to yourself, "Wow, this is easy." + + align:start position:0% +think to yourself, "Wow, this is easy." + + + align:start position:0% +think to yourself, "Wow, this is easy." +And if you did, wow. But um um basically + + align:start position:0% +And if you did, wow. But um um basically + + + align:start position:0% +And if you did, wow. But um um basically +Photoshop has hundreds or perhaps even a + + align:start position:0% +Photoshop has hundreds or perhaps even a + + + align:start position:0% +Photoshop has hundreds or perhaps even a +thousands of features in there that you + + align:start position:0% +thousands of features in there that you + + + align:start position:0% +thousands of features in there that you +don't know about until you've taken the + + align:start position:0% +don't know about until you've taken the + + + align:start position:0% +don't know about until you've taken the +classes. And if you want to figure out + + align:start position:0% +classes. And if you want to figure out + + + align:start position:0% +classes. And if you want to figure out +something about Photoshop, your best bet + + align:start position:0% +something about Photoshop, your best bet + + + align:start position:0% +something about Photoshop, your best bet +really is to go to a search prompt and + + align:start position:0% +really is to go to a search prompt and + + + align:start position:0% +really is to go to a search prompt and +go to your favorite search engine and + + align:start position:0% +go to your favorite search engine and + + + align:start position:0% +go to your favorite search engine and +find out what to do or ask someone who + + align:start position:0% +find out what to do or ask someone who + + + align:start position:0% +find out what to do or ask someone who +knows because actually trying to figure + + align:start position:0% +knows because actually trying to figure + + + align:start position:0% +knows because actually trying to figure +out Photoshop from first principles is + + align:start position:0% +out Photoshop from first principles is + + + align:start position:0% +out Photoshop from first principles is +really, really, really + + align:start position:0% +really, really, really + + + align:start position:0% +really, really, really +hard. The thing is is that with a game, + + align:start position:0% +hard. The thing is is that with a game, + + + align:start position:0% +hard. The thing is is that with a game, +you can't do that. You can't get away + + align:start position:0% +you can't do that. You can't get away + + + align:start position:0% +you can't do that. You can't get away +with that. If your game is complex, you + + align:start position:0% +with that. If your game is complex, you + + + align:start position:0% +with that. If your game is complex, you +no one's going to take a training class + + align:start position:0% +no one's going to take a training class + + + align:start position:0% +no one's going to take a training class +to learn how to play your game. Now, it + + align:start position:0% +to learn how to play your game. Now, it + + + align:start position:0% +to learn how to play your game. Now, it +might be the case that someone will look + + align:start position:0% +might be the case that someone will look + + + align:start position:0% +might be the case that someone will look +at a walkthrough or a cheat sheet or + + align:start position:0% +at a walkthrough or a cheat sheet or + + + align:start position:0% +at a walkthrough or a cheat sheet or +something to play your game after + + align:start position:0% +something to play your game after + + + align:start position:0% +something to play your game after +they've played for three hours and + + align:start position:0% +they've played for three hours and + + + align:start position:0% +they've played for three hours and +decide they liked it, but they're not + + align:start position:0% +decide they liked it, but they're not + + + align:start position:0% +decide they liked it, but they're not +going to do that first. When I say + + align:start position:0% +going to do that first. When I say + + + align:start position:0% +going to do that first. When I say +that's a general, broad, sweeping + + align:start position:0% +that's a general, broad, sweeping + + + align:start position:0% +that's a general, broad, sweeping +generalization. There are some people + + align:start position:0% +generalization. There are some people + + + align:start position:0% +generalization. There are some people +that like nothing more than to read the + + align:start position:0% +that like nothing more than to read the + + + align:start position:0% +that like nothing more than to read the +manual for a game. They mostly died out + + align:start position:0% +manual for a game. They mostly died out + + + align:start position:0% +manual for a game. They mostly died out +about 10 years ago, but they are still + + align:start position:0% +about 10 years ago, but they are still + + + align:start position:0% +about 10 years ago, but they are still +some hanging on. Generally speaking, + + align:start position:0% +some hanging on. Generally speaking, + + + align:start position:0% +some hanging on. Generally speaking, +nowadays, you're going to play the game + + align:start position:0% +nowadays, you're going to play the game + + + align:start position:0% +nowadays, you're going to play the game +and then you're going to decide if + + align:start position:0% +and then you're going to decide if + + + align:start position:0% +and then you're going to decide if +you're going to read the instructions or + + align:start position:0% +you're going to read the instructions or + + + align:start position:0% +you're going to read the instructions or +not. And this is going to be true for + + align:start position:0% +not. And this is going to be true for + + + align:start position:0% +not. And this is going to be true for +your games as well. So your UI task, + + align:start position:0% +your games as well. So your UI task, + + + align:start position:0% +your games as well. So your UI task, +your user interaction piece for your + + align:start position:0% +your user interaction piece for your + + + align:start position:0% +your user interaction piece for your +game is going to be hard. And the only + + align:start position:0% +game is going to be hard. And the only + + + align:start position:0% +game is going to be hard. And the only +way to make sure that works properly is + + align:start position:0% +way to make sure that works properly is + + + align:start position:0% +way to make sure that works properly is +to test it over and over again as early + + align:start position:0% +to test it over and over again as early + + + align:start position:0% +to test it over and over again as early +as possible. And so that's one way in + + align:start position:0% +as possible. And so that's one way in + + + align:start position:0% +as possible. And so that's one way in +which games are going to be a little bit + + align:start position:0% +which games are going to be a little bit + + + align:start position:0% +which games are going to be a little bit +harder than normal + + align:start position:0% +harder than normal + + + align:start position:0% +harder than normal +software. Also, games have to be fun. + + align:start position:0% +software. Also, games have to be fun. + + + align:start position:0% +software. Also, games have to be fun. +And we use the word fun kind of loosely. + + align:start position:0% +And we use the word fun kind of loosely. + + + align:start position:0% +And we use the word fun kind of loosely. +We're always scared of using the word + + align:start position:0% +We're always scared of using the word + + + align:start position:0% +We're always scared of using the word +fun because there are serious games. + + align:start position:0% +fun because there are serious games. + + + align:start position:0% +fun because there are serious games. +There are games that are supposed to + + align:start position:0% +There are games that are supposed to + + + align:start position:0% +There are games that are supposed to +make you think instead of have get a big + + align:start position:0% +make you think instead of have get a big + + + align:start position:0% +make you think instead of have get a big +smile on your face. But what they have + + align:start position:0% +smile on your face. But what they have + + + align:start position:0% +smile on your face. But what they have +to be is engaging or interesting. + + align:start position:0% +to be is engaging or interesting. + + + align:start position:0% +to be is engaging or interesting. +Photoshop's not a great example. If + + align:start position:0% +Photoshop's not a great example. If + + + align:start position:0% +Photoshop's not a great example. If +you're playing with Photoshop as as an + + align:start position:0% +you're playing with Photoshop as as an + + + align:start position:0% +you're playing with Photoshop as as an +undergrad, you're probably thinking to + + align:start position:0% +undergrad, you're probably thinking to + + + align:start position:0% +undergrad, you're probably thinking to +yourself, "This is kind of fun." But if + + align:start position:0% +yourself, "This is kind of fun." But if + + + align:start position:0% +yourself, "This is kind of fun." But if +you're using a fancy piece of software + + align:start position:0% +you're using a fancy piece of software + + + align:start position:0% +you're using a fancy piece of software +for work, you're not doing that because + + align:start position:0% +for work, you're not doing that because + + + align:start position:0% +for work, you're not doing that because +it's fun. You're probably doing it + + align:start position:0% +it's fun. You're probably doing it + + + align:start position:0% +it's fun. You're probably doing it +because someone's paying you to do it. + + align:start position:0% +because someone's paying you to do it. + + + align:start position:0% +because someone's paying you to do it. +The games, not so much. Um, people are + + align:start position:0% +The games, not so much. Um, people are + + + align:start position:0% +The games, not so much. Um, people are +going to play it because they want to + + align:start position:0% +going to play it because they want to + + + align:start position:0% +going to play it because they want to +play it and for really no other reason. + + align:start position:0% +play it and for really no other reason. + + + align:start position:0% +play it and for really no other reason. +And so your game has to be fun. And what + + align:start position:0% +And so your game has to be fun. And what + + + align:start position:0% +And so your game has to be fun. And what +you think is fun, they may not think is + + align:start position:0% +you think is fun, they may not think is + + + align:start position:0% +you think is fun, they may not think is +fun. So, the only way to make sure that + + align:start position:0% +fun. So, the only way to make sure that + + + align:start position:0% +fun. So, the only way to make sure that +your game is fun is to find some users + + align:start position:0% +your game is fun is to find some users + + + align:start position:0% +your game is fun is to find some users +really quick and try out your game on + + align:start position:0% +really quick and try out your game on + + + align:start position:0% +really quick and try out your game on +them as soon as you possibly can. Same + + align:start position:0% +them as soon as you possibly can. Same + + + align:start position:0% +them as soon as you possibly can. Same +thing happens with your gameplay + + align:start position:0% +thing happens with your gameplay + + + align:start position:0% +thing happens with your gameplay +difficulty. By the time you're done with + + align:start position:0% +difficulty. By the time you're done with + + + align:start position:0% +difficulty. By the time you're done with +your game, you're going to just you're + + align:start position:0% +your game, you're going to just you're + + + align:start position:0% +your game, you're going to just you're +going to think the game is too easy. + + align:start position:0% +going to think the game is too easy. + + + align:start position:0% +going to think the game is too easy. +Guarantee it. And everyone who plays it + + align:start position:0% +Guarantee it. And everyone who plays it + + + align:start position:0% +Guarantee it. And everyone who plays it +for the first time will think it's too + + align:start position:0% +for the first time will think it's too + + + align:start position:0% +for the first time will think it's too +hard. Guarantee that, too. So, you have + + align:start position:0% +hard. Guarantee that, too. So, you have + + + align:start position:0% +hard. Guarantee that, too. So, you have +to test it with other users, not + + align:start position:0% +to test it with other users, not + + + align:start position:0% +to test it with other users, not +yourselves, because you will think your + + align:start position:0% +yourselves, because you will think your + + + align:start position:0% +yourselves, because you will think your +game is too easy, and you'll be + + align:start position:0% +game is too easy, and you'll be + + + align:start position:0% +game is too easy, and you'll be +wrong. And then, of course, finally, + + align:start position:0% +wrong. And then, of course, finally, + + + align:start position:0% +wrong. And then, of course, finally, +your game may have an impact you want to + + align:start position:0% +your game may have an impact you want to + + + align:start position:0% +your game may have an impact you want to +have. And I'm gonna keep saying this + + align:start position:0% +have. And I'm gonna keep saying this + + + align:start position:0% +have. And I'm gonna keep saying this +over again. You're gonna have to test + + align:start position:0% +over again. You're gonna have to test + + + align:start position:0% +over again. You're gonna have to test +your game. Remember, there's a theme + + align:start position:0% +your game. Remember, there's a theme + + + align:start position:0% +your game. Remember, there's a theme +that's going to be keep going on here. + + align:start position:0% +that's going to be keep going on here. + + + align:start position:0% +that's going to be keep going on here. +And we're going to use this theme in + + align:start position:0% +And we're going to use this theme in + + + align:start position:0% +And we're going to use this theme in +absolutely everything we do. When you're + + align:start position:0% +absolutely everything we do. When you're + + + align:start position:0% +absolutely everything we do. When you're +playing a game, you try something, it + + align:start position:0% +playing a game, you try something, it + + + align:start position:0% +playing a game, you try something, it +doesn't work. You think about it, you + + align:start position:0% +doesn't work. You think about it, you + + + align:start position:0% +doesn't work. You think about it, you +try something new. When you're + + align:start position:0% +try something new. When you're + + + align:start position:0% +try something new. When you're +developing a game, you're going to try + + align:start position:0% +developing a game, you're going to try + + + align:start position:0% +developing a game, you're going to try +something, it's not going to work. You + + align:start position:0% +something, it's not going to work. You + + + align:start position:0% +something, it's not going to work. You +try something new. When you're trying to + + align:start position:0% +try something new. When you're trying to + + + align:start position:0% +try something new. When you're trying to +make your team work smoothly together, + + align:start position:0% +make your team work smoothly together, + + + align:start position:0% +make your team work smoothly together, +you're going to try something and that's + + align:start position:0% +you're going to try something and that's + + + align:start position:0% +you're going to try something and that's +not going to work, and you'll try + + align:start position:0% +not going to work, and you'll try + + + align:start position:0% +not going to work, and you'll try +something new. We're going to talk about + + align:start position:0% +something new. We're going to talk about + + + align:start position:0% +something new. We're going to talk about +that circle over and over and over again + + align:start position:0% +that circle over and over and over again + + + align:start position:0% +that circle over and over and over again +in the class because it works. + + align:start position:0% +in the class because it works. + + + align:start position:0% +in the class because it works. +So, moving on, we're going to talk about + + align:start position:0% +So, moving on, we're going to talk about + + + align:start position:0% +So, moving on, we're going to talk about +game engines. Um, and if I talk too + + align:start position:0% +game engines. Um, and if I talk too + + + align:start position:0% +game engines. Um, and if I talk too +quickly, as I have a habit of doing, + + align:start position:0% +quickly, as I have a habit of doing, + + + align:start position:0% +quickly, as I have a habit of doing, +even more so when I'm talking to people, + + align:start position:0% +even more so when I'm talking to people, + + + align:start position:0% +even more so when I'm talking to people, +let me know. Tell me to slow + + align:start position:0% +let me know. Tell me to slow + + + align:start position:0% +let me know. Tell me to slow +down. All right. + + align:start position:0% +down. All right. + + + align:start position:0% +down. All right. +So, this is the game you want to + + align:start position:0% +So, this is the game you want to + + + align:start position:0% +So, this is the game you want to +make. It's beautiful. + + align:start position:0% +make. It's beautiful. + + + align:start position:0% +make. It's beautiful. +And this is the tools you have to make + + align:start position:0% + + + + align:start position:0% + +it. So obviously what you're really + + align:start position:0% +it. So obviously what you're really + + + align:start position:0% +it. So obviously what you're really +going to do is going to be somewhere in + + align:start position:0% +going to do is going to be somewhere in + + + align:start position:0% +going to do is going to be somewhere in +between these two + + align:start position:0% +between these two + + + align:start position:0% +between these two +extremes. Um and you have to think + + align:start position:0% +extremes. Um and you have to think + + + align:start position:0% +extremes. Um and you have to think +really hard about how you're going to + + align:start position:0% +really hard about how you're going to + + + align:start position:0% +really hard about how you're going to +accomplish it. Vast majority of game + + align:start position:0% +accomplish it. Vast majority of game + + + align:start position:0% +accomplish it. Vast majority of game +developers, especially new ones, are + + align:start position:0% +developers, especially new ones, are + + + align:start position:0% +developers, especially new ones, are +going to come into it thinking this is + + align:start position:0% +going to come into it thinking this is + + + align:start position:0% +going to come into it thinking this is +the awesome perfect thing I want to + + align:start position:0% +the awesome perfect thing I want to + + + align:start position:0% +the awesome perfect thing I want to +create. And then they're going to come + + align:start position:0% +create. And then they're going to come + + + align:start position:0% +create. And then they're going to come +to their tools and they're going to + + align:start position:0% +to their tools and they're going to + + + align:start position:0% +to their tools and they're going to +discover that's really hard to do. And + + align:start position:0% +discover that's really hard to do. And + + + align:start position:0% +discover that's really hard to do. And +so I encourage you rather than thinking + + align:start position:0% +so I encourage you rather than thinking + + + align:start position:0% +so I encourage you rather than thinking +of the big vision of what you want to + + align:start position:0% +of the big vision of what you want to + + + align:start position:0% +of the big vision of what you want to +make and then figure out how to get + + align:start position:0% +make and then figure out how to get + + + align:start position:0% +make and then figure out how to get +there, I recommend thinking about what + + align:start position:0% +there, I recommend thinking about what + + + align:start position:0% +there, I recommend thinking about what +you've + + align:start position:0% +you've + + + align:start position:0% +you've +got and figuring out what can you + + align:start position:0% +got and figuring out what can you + + + align:start position:0% +got and figuring out what can you +make. Now, these are a couple things you + + align:start position:0% +make. Now, these are a couple things you + + + align:start position:0% +make. Now, these are a couple things you +can do here. Uh, one, reduce in your + + align:start position:0% +can do here. Uh, one, reduce in your + + + align:start position:0% +can do here. Uh, one, reduce in your +mind the scope of the thing you're going + + align:start position:0% +mind the scope of the thing you're going + + + align:start position:0% +mind the scope of the thing you're going +to make. You're not going to make your + + align:start position:0% +to make. You're not going to make your + + + align:start position:0% +to make. You're not going to make your +favorite RPG. You're not going to make + + align:start position:0% +favorite RPG. You're not going to make + + + align:start position:0% +favorite RPG. You're not going to make +an MMO. Um, if you try, we will laugh at + + align:start position:0% +an MMO. Um, if you try, we will laugh at + + + align:start position:0% +an MMO. Um, if you try, we will laugh at +you. Um, but so you should you you will + + align:start position:0% +you. Um, but so you should you you will + + + align:start position:0% +you. Um, but so you should you you will +occasionally think about this top row. + + align:start position:0% +occasionally think about this top row. + + + align:start position:0% +occasionally think about this top row. +How do I get the awesome thing? But I + + align:start position:0% +How do I get the awesome thing? But I + + + align:start position:0% +How do I get the awesome thing? But I +really want to encourage you instead to + + align:start position:0% +really want to encourage you instead to + + + align:start position:0% +really want to encourage you instead to +think as much as you possibly can. This + + align:start position:0% +think as much as you possibly can. This + + + align:start position:0% +think as much as you possibly can. This +is what I know how to do. These are the + + align:start position:0% +is what I know how to do. These are the + + + align:start position:0% +is what I know how to do. These are the +tools I have. What awesome thing can I + + align:start position:0% +tools I have. What awesome thing can I + + + align:start position:0% +tools I have. What awesome thing can I +do with these tools rather than how do I + + align:start position:0% +do with these tools rather than how do I + + + align:start position:0% +do with these tools rather than how do I +get over there when I'm way over here + + align:start position:0% +get over there when I'm way over here + + + align:start position:0% +get over there when I'm way over here +right + + align:start position:0% + + + + align:start position:0% + +now? All right. Um, this is a quote from + + align:start position:0% +now? All right. Um, this is a quote from + + + align:start position:0% +now? All right. Um, this is a quote from +a discussion I had with a game team once + + align:start position:0% +a discussion I had with a game team once + + + align:start position:0% +a discussion I had with a game team once +where we were talking about a particular + + align:start position:0% +where we were talking about a particular + + + align:start position:0% +where we were talking about a particular +technical problem and I said, "How hard + + align:start position:0% +technical problem and I said, "How hard + + + align:start position:0% +technical problem and I said, "How hard +is that?" And the developer says, "Well, + + align:start position:0% +is that?" And the developer says, "Well, + + + align:start position:0% +is that?" And the developer says, "Well, +it's it's really hard because of this, + + align:start position:0% +it's it's really hard because of this, + + + align:start position:0% +it's it's really hard because of this, +that, the other thing." I said, "Wait, + + align:start position:0% +that, the other thing." I said, "Wait, + + + align:start position:0% +that, the other thing." I said, "Wait, +stop. Actually, I didn't mean that. I + + align:start position:0% +stop. Actually, I didn't mean that. I + + + align:start position:0% +stop. Actually, I didn't mean that. I +don't care how hard it is. What I want + + align:start position:0% +don't care how hard it is. What I want + + + align:start position:0% +don't care how hard it is. What I want +to know is how long is it going to + + align:start position:0% +to know is how long is it going to + + + align:start position:0% +to know is how long is it going to +take?" And we're going to say that a lot + + align:start position:0% +take?" And we're going to say that a lot + + + align:start position:0% +take?" And we're going to say that a lot +in this class, too. We're going to say, + + align:start position:0% +in this class, too. We're going to say, + + + align:start position:0% +in this class, too. We're going to say, +"How hard is something?" And often what + + align:start position:0% +"How hard is something?" And often what + + + align:start position:0% +"How hard is something?" And often what +we really mean is how long is it going + + align:start position:0% +we really mean is how long is it going + + + align:start position:0% +we really mean is how long is it going +to take? Because we don't care if it + + align:start position:0% +to take? Because we don't care if it + + + align:start position:0% +to take? Because we don't care if it +takes an hour of really hard thinking to + + align:start position:0% +takes an hour of really hard thinking to + + + align:start position:0% +takes an hour of really hard thinking to +some extent. What we care is that it + + align:start position:0% +some extent. What we care is that it + + + align:start position:0% +some extent. What we care is that it +takes an hour. If it's going to take you + + align:start position:0% +takes an hour. If it's going to take you + + + align:start position:0% +takes an hour. If it's going to take you +an hour to do an easy thing like sort a + + align:start position:0% +an hour to do an easy thing like sort a + + + align:start position:0% +an hour to do an easy thing like sort a +bunch of yellow um stickers and a bunch + + align:start position:0% +bunch of yellow um stickers and a bunch + + + align:start position:0% +bunch of yellow um stickers and a bunch +of orange stickers because that's part + + align:start position:0% +of orange stickers because that's part + + + align:start position:0% +of orange stickers because that's part +of your game prototype. If it takes an + + align:start position:0% +of your game prototype. If it takes an + + + align:start position:0% +of your game prototype. If it takes an +hour to do that, that's an hour. It + + align:start position:0% +hour to do that, that's an hour. It + + + align:start position:0% +hour to do that, that's an hour. It +doesn't matter that that's an easy task. + + align:start position:0% +doesn't matter that that's an easy task. + + + align:start position:0% +doesn't matter that that's an easy task. +That's time. And you have to be very + + align:start position:0% +That's time. And you have to be very + + + align:start position:0% +That's time. And you have to be very +careful how you spend your time in this + + align:start position:0% +careful how you spend your time in this + + + align:start position:0% +careful how you spend your time in this +class. actually through all your classes + + align:start position:0% +class. actually through all your classes + + + align:start position:0% +class. actually through all your classes +at MIT I suspect but in this class we + + align:start position:0% +at MIT I suspect but in this class we + + + align:start position:0% +at MIT I suspect but in this class we +know that there you don't have enough + + align:start position:0% +know that there you don't have enough + + + align:start position:0% +know that there you don't have enough +time to get done everything that you + + align:start position:0% +time to get done everything that you + + + align:start position:0% +time to get done everything that you +want to get done and so you think very + + align:start position:0% +want to get done and so you think very + + + align:start position:0% +want to get done and so you think very +carefully about how you spend your + + align:start position:0% +carefully about how you spend your + + + align:start position:0% +carefully about how you spend your +time turns out that game development is + + align:start position:0% +time turns out that game development is + + + align:start position:0% +time turns out that game development is +already hard you don't need to add hard + + align:start position:0% +already hard you don't need to add hard + + + align:start position:0% +already hard you don't need to add hard +stuff to + + align:start position:0% + + + + align:start position:0% + +it so a lot of what we're going to focus + + align:start position:0% +it so a lot of what we're going to focus + + + align:start position:0% +it so a lot of what we're going to focus +on with choosing a game engine and all + + align:start position:0% +on with choosing a game engine and all + + + align:start position:0% +on with choosing a game engine and all +the decisions you make is you want to + + align:start position:0% +the decisions you make is you want to + + + align:start position:0% +the decisions you make is you want to +write as little code as possible and + + align:start position:0% +write as little code as possible and + + + align:start position:0% +write as little code as possible and +that's not because you know we we're + + align:start position:0% +that's not because you know we we're + + + align:start position:0% +that's not because you know we we're +afraid of code but because every line of + + align:start position:0% +afraid of code but because every line of + + + align:start position:0% +afraid of code but because every line of +code you write is time. Every 10 lines + + align:start position:0% +code you write is time. Every 10 lines + + + align:start position:0% +code you write is time. Every 10 lines +of code you write is a + + align:start position:0% +of code you write is a + + + align:start position:0% +of code you write is a +bug, right? So what we want to do is + + align:start position:0% +bug, right? So what we want to do is + + + align:start position:0% +bug, right? So what we want to do is +minimize the number of lines of code you + + align:start position:0% +minimize the number of lines of code you + + + align:start position:0% +minimize the number of lines of code you +write. We want to minimize the number of + + align:start position:0% +write. We want to minimize the number of + + + align:start position:0% +write. We want to minimize the number of +bugs you write because when it gets to + + align:start position:0% +bugs you write because when it gets to + + + align:start position:0% +bugs you write because when it gets to +be the bug stage that takes even more + + align:start position:0% +be the bug stage that takes even more + + + align:start position:0% +be the bug stage that takes even more +time to find it, to fix it, to ch write + + align:start position:0% +time to find it, to fix it, to ch write + + + align:start position:0% +time to find it, to fix it, to ch write +new code to fix it. So we want to reduce + + align:start position:0% +new code to fix it. So we want to reduce + + + align:start position:0% +new code to fix it. So we want to reduce +as much as possible all of that time. + + align:start position:0% + + + + align:start position:0% + +So, we want to use all the tools we can + + align:start position:0% +So, we want to use all the tools we can + + + align:start position:0% +So, we want to use all the tools we can +to reduce the amount of code we're going + + align:start position:0% +to reduce the amount of code we're going + + + align:start position:0% +to reduce the amount of code we're going +to write. One of our big ones is we we + + align:start position:0% +to write. One of our big ones is we we + + + align:start position:0% +to write. One of our big ones is we we +use we call it paper prototyping. We + + align:start position:0% +use we call it paper prototyping. We + + + align:start position:0% +use we call it paper prototyping. We +don't actually mean paper. We mean + + align:start position:0% +don't actually mean paper. We mean + + + align:start position:0% +don't actually mean paper. We mean +whatever materials you can use, your um + + align:start position:0% +whatever materials you can use, your um + + + align:start position:0% +whatever materials you can use, your um +chalk, pieces of plastic, dice, frisbes, + + align:start position:0% +chalk, pieces of plastic, dice, frisbes, + + + align:start position:0% +chalk, pieces of plastic, dice, frisbes, +anything you can use to make your game + + align:start position:0% +anything you can use to make your game + + + align:start position:0% +anything you can use to make your game +without writing a line of code, you + + align:start position:0% +without writing a line of code, you + + + align:start position:0% +without writing a line of code, you +should try it. Test it that way because + + align:start position:0% +should try it. Test it that way because + + + align:start position:0% +should try it. Test it that way because +it's so much faster to test it that way. + + align:start position:0% +it's so much faster to test it that way. + + + align:start position:0% +it's so much faster to test it that way. +And what else do we have up here? Iter + + align:start position:0% +And what else do we have up here? Iter + + + align:start position:0% +And what else do we have up here? Iter +of design. I've talked about this + + align:start position:0% +of design. I've talked about this + + + align:start position:0% +of design. I've talked about this +before, but we're going to use the + + align:start position:0% +before, but we're going to use the + + + align:start position:0% +before, but we're going to use the +phrase iterative design to talk about + + align:start position:0% +phrase iterative design to talk about + + + align:start position:0% +phrase iterative design to talk about +that whole cycle where you try + + align:start position:0% +that whole cycle where you try + + + align:start position:0% +that whole cycle where you try +something, see how it worked or didn't + + align:start position:0% +something, see how it worked or didn't + + + align:start position:0% +something, see how it worked or didn't +work, change it, try it again. That's + + align:start position:0% +work, change it, try it again. That's + + + align:start position:0% +work, change it, try it again. That's +iteration. And we're going to talk about + + align:start position:0% +iteration. And we're going to talk about + + + align:start position:0% +iteration. And we're going to talk about +that a huge, huge amount. And one of the + + align:start position:0% +that a huge, huge amount. And one of the + + + align:start position:0% +that a huge, huge amount. And one of the +big parts of this, of course, is game + + align:start position:0% +big parts of this, of course, is game + + + align:start position:0% +big parts of this, of course, is game +engines, which is not to say that you're + + align:start position:0% +engines, which is not to say that you're + + + align:start position:0% +engines, which is not to say that you're +going to build your game engine, but + + align:start position:0% +going to build your game engine, but + + + align:start position:0% +going to build your game engine, but +rather you're going to try stuff and the + + align:start position:0% +rather you're going to try stuff and the + + + align:start position:0% +rather you're going to try stuff and the +game engines will let you iterate + + align:start position:0% +game engines will let you iterate + + + align:start position:0% +game engines will let you iterate +faster, do more with less code, and get + + align:start position:0% +faster, do more with less code, and get + + + align:start position:0% +faster, do more with less code, and get +more done. + + align:start position:0% + + + + align:start position:0% + +All right. So again, you're going to use + + align:start position:0% +All right. So again, you're going to use + + + align:start position:0% +All right. So again, you're going to use +a game engine to save yourself some + + align:start position:0% +a game engine to save yourself some + + + align:start position:0% +a game engine to save yourself some +time. You don't want to re reinvent the + + align:start position:0% +time. You don't want to re reinvent the + + + align:start position:0% +time. You don't want to re reinvent the +wheel. I'm confident that you could + + align:start position:0% +wheel. I'm confident that you could + + + align:start position:0% +wheel. I'm confident that you could +write a game engine if you wanted to, + + align:start position:0% +write a game engine if you wanted to, + + + align:start position:0% +write a game engine if you wanted to, +but I don't think it's worth your time. + + align:start position:0% +but I don't think it's worth your time. + + + align:start position:0% +but I don't think it's worth your time. +Someone else has already done it. They + + align:start position:0% +Someone else has already done it. They + + + align:start position:0% +Someone else has already done it. They +may or may not have done a better job + + align:start position:0% +may or may not have done a better job + + + align:start position:0% +may or may not have done a better job +than you can do, but you can bet that + + align:start position:0% +than you can do, but you can bet that + + + align:start position:0% +than you can do, but you can bet that +the thing that you're going to get from + + align:start position:0% +the thing that you're going to get from + + + align:start position:0% +the thing that you're going to get from +your game engine will be faster than if + + align:start position:0% +your game engine will be faster than if + + + align:start position:0% +your game engine will be faster than if +you stopped and wrote it from scratch. + + align:start position:0% + + + + align:start position:0% + +And then finally, the game engine that + + align:start position:0% +And then finally, the game engine that + + + align:start position:0% +And then finally, the game engine that +you write from scratch, for every 10 + + align:start position:0% +you write from scratch, for every 10 + + + align:start position:0% +you write from scratch, for every 10 +lines of code, you've got a bug. I'm + + align:start position:0% +lines of code, you've got a bug. I'm + + + align:start position:0% +lines of code, you've got a bug. I'm +making that number up, but it sounds + + align:start position:0% +making that number up, but it sounds + + + align:start position:0% +making that number up, but it sounds +good. + + align:start position:0% +good. + + + align:start position:0% +good. +Um, that means that the game engine you + + align:start position:0% +Um, that means that the game engine you + + + align:start position:0% +Um, that means that the game engine you +write has bugs. Now, I'm not going to + + align:start position:0% +write has bugs. Now, I'm not going to + + + align:start position:0% +write has bugs. Now, I'm not going to +claim that game engines that we're going + + align:start position:0% +claim that game engines that we're going + + + align:start position:0% +claim that game engines that we're going +to suggest you use don't have bugs. They + + align:start position:0% +to suggest you use don't have bugs. They + + + align:start position:0% +to suggest you use don't have bugs. They +totally have bugs. But what we have is + + align:start position:0% +totally have bugs. But what we have is + + + align:start position:0% +totally have bugs. But what we have is +10,000 monkeys on the internet using + + align:start position:0% +10,000 monkeys on the internet using + + + align:start position:0% +10,000 monkeys on the internet using +that game engine reporting the bugs. And + + align:start position:0% +that game engine reporting the bugs. And + + + align:start position:0% +that game engine reporting the bugs. And +there have been a lot of cycles of + + align:start position:0% +there have been a lot of cycles of + + + align:start position:0% +there have been a lot of cycles of +people fixing bugs. And so hopefully the + + align:start position:0% +people fixing bugs. And so hopefully the + + + align:start position:0% +people fixing bugs. And so hopefully the +worst ones are out of your + + align:start position:0% + + + + align:start position:0% + +way. The other thing you can do with the + + align:start position:0% +way. The other thing you can do with the + + + align:start position:0% +way. The other thing you can do with the +game engine is you can use it as your + + align:start position:0% +game engine is you can use it as your + + + align:start position:0% +game engine is you can use it as your +tinker toys. We talked about before you + + align:start position:0% +tinker toys. We talked about before you + + + align:start position:0% +tinker toys. We talked about before you +your game engine has the list of things + + align:start position:0% +your game engine has the list of things + + + align:start position:0% +your game engine has the list of things +it does well. Great. Use those things as + + align:start position:0% +it does well. Great. Use those things as + + + align:start position:0% +it does well. Great. Use those things as +tools. Take advantage of that. Do + + align:start position:0% +tools. Take advantage of that. Do + + + align:start position:0% +tools. Take advantage of that. Do +everything you can with those tools. And + + align:start position:0% +everything you can with those tools. And + + + align:start position:0% +everything you can with those tools. And +if it can't do something, don't fight + + align:start position:0% +if it can't do something, don't fight + + + align:start position:0% +if it can't do something, don't fight +it. Don't say game engine, darn you. If + + align:start position:0% +it. Don't say game engine, darn you. If + + + align:start position:0% +it. Don't say game engine, darn you. If +only you did this thing. and think how + + align:start position:0% +only you did this thing. and think how + + + align:start position:0% +only you did this thing. and think how +can we change our design to not need + + align:start position:0% +can we change our design to not need + + + align:start position:0% +can we change our design to not need +that. It's another advantage you can + + align:start position:0% +that. It's another advantage you can + + + align:start position:0% +that. It's another advantage you can +another trick you can play. If you limit + + align:start position:0% +another trick you can play. If you limit + + + align:start position:0% +another trick you can play. If you limit +your design sometimes that increases + + align:start position:0% +your design sometimes that increases + + + align:start position:0% +your design sometimes that increases +your creativity and it can actually help + + align:start position:0% +your creativity and it can actually help + + + align:start position:0% +your creativity and it can actually help +you get your game done + + align:start position:0% + + + + align:start position:0% + +faster. + + align:start position:0% +faster. + + + align:start position:0% +faster. +So throughout this class I I use this + + align:start position:0% +So throughout this class I I use this + + + align:start position:0% +So throughout this class I I use this +phrase. I'm not sure anyone else does + + align:start position:0% +phrase. I'm not sure anyone else does + + + align:start position:0% +phrase. I'm not sure anyone else does +but I consider certain things to be + + align:start position:0% +but I consider certain things to be + + + align:start position:0% +but I consider certain things to be +nooes. Um, there are some things we will + + align:start position:0% +nooes. Um, there are some things we will + + + align:start position:0% +nooes. Um, there are some things we will +tell you you cannot do or that we tell + + align:start position:0% +tell you you cannot do or that we tell + + + align:start position:0% +tell you you cannot do or that we tell +you not to do flat out and those things + + align:start position:0% +you not to do flat out and those things + + + align:start position:0% +you not to do flat out and those things +don't do them. Okay? But there are some + + align:start position:0% +don't do them. Okay? But there are some + + + align:start position:0% +don't do them. Okay? But there are some +things that we're going to say we + + align:start position:0% +things that we're going to say we + + + align:start position:0% +things that we're going to say we +recommend that you don't do that or you + + align:start position:0% +recommend that you don't do that or you + + + align:start position:0% +recommend that you don't do that or you +know no team has tried that and + + align:start position:0% +know no team has tried that and + + + align:start position:0% +know no team has tried that and +succeeded + + align:start position:0% +succeeded + + + align:start position:0% +succeeded +yet. Those I consider nooes. You can try + + align:start position:0% +yet. Those I consider nooes. You can try + + + align:start position:0% +yet. Those I consider nooes. You can try +them and you can put your head in there + + align:start position:0% +them and you can put your head in there + + + align:start position:0% +them and you can put your head in there +and see how comfortable it is. But + + align:start position:0% +and see how comfortable it is. But + + + align:start position:0% +and see how comfortable it is. But +probably by the end of the class you'll + + align:start position:0% +probably by the end of the class you'll + + + align:start position:0% +probably by the end of the class you'll +say, "Wow, you know what? when you said + + align:start position:0% +say, "Wow, you know what? when you said + + + align:start position:0% +say, "Wow, you know what? when you said +not to do multiplayer network play, you + + align:start position:0% +not to do multiplayer network play, you + + + align:start position:0% +not to do multiplayer network play, you +were right. We have heard that every + + align:start position:0% +were right. We have heard that every + + + align:start position:0% +were right. We have heard that every +year. We will hear it this year, I + + align:start position:0% +year. We will hear it this year, I + + + align:start position:0% +year. We will hear it this year, I +suspect. Um, but again, we're not + + align:start position:0% +suspect. Um, but again, we're not + + + align:start position:0% +suspect. Um, but again, we're not +telling you to never try crazy things, + + align:start position:0% +telling you to never try crazy things, + + + align:start position:0% +telling you to never try crazy things, +but merely be aware of what the crazy + + align:start position:0% +but merely be aware of what the crazy + + + align:start position:0% +but merely be aware of what the crazy +things are. If if if we're suggesting + + align:start position:0% +things are. If if if we're suggesting + + + align:start position:0% +things are. If if if we're suggesting +you not try something, but not telling + + align:start position:0% +you not try something, but not telling + + + align:start position:0% +you not try something, but not telling +you you can't do it, and we're looking + + align:start position:0% +you you can't do it, and we're looking + + + align:start position:0% +you you can't do it, and we're looking +kind of pained when we say it, be aware + + align:start position:0% +kind of pained when we say it, be aware + + + align:start position:0% +kind of pained when we say it, be aware +this is a huge risk for your project. Be + + align:start position:0% +this is a huge risk for your project. Be + + + align:start position:0% +this is a huge risk for your project. Be +aware that this is a place where you + + align:start position:0% +aware that this is a place where you + + + align:start position:0% +aware that this is a place where you +should be putting a lot of early + + align:start position:0% +should be putting a lot of early + + + align:start position:0% +should be putting a lot of early +attention to make sure that you have + + align:start position:0% +attention to make sure that you have + + + align:start position:0% +attention to make sure that you have +backup plan if it + + align:start position:0% + + + + align:start position:0% + +fails. All right, on we go. Now, we're + + align:start position:0% +fails. All right, on we go. Now, we're + + + align:start position:0% +fails. All right, on we go. Now, we're +actually going to talk a little bit + + align:start position:0% +actually going to talk a little bit + + + align:start position:0% +actually going to talk a little bit +about the thing we're supposed to talk + + align:start position:0% +about the thing we're supposed to talk + + + align:start position:0% +about the thing we're supposed to talk +about. Picking game engine is super + + align:start position:0% +about. Picking game engine is super + + + align:start position:0% +about. Picking game engine is super +important. Everything involved in your + + align:start position:0% +important. Everything involved in your + + + align:start position:0% +important. Everything involved in your +game relies on it. But + + align:start position:0% +game relies on it. But + + + align:start position:0% +game relies on it. But +again, contradictory, don't worry about + + align:start position:0% +again, contradictory, don't worry about + + + align:start position:0% +again, contradictory, don't worry about +it because you have four projects and + + align:start position:0% +it because you have four projects and + + + align:start position:0% +it because you have four projects and +the first first one doesn't count for + + align:start position:0% +the first first one doesn't count for + + + align:start position:0% +the first first one doesn't count for +game engines because you're not using + + align:start position:0% +game engines because you're not using + + + align:start position:0% +game engines because you're not using +game engine. But for two and three, I + + align:start position:0% +game engine. But for two and three, I + + + align:start position:0% +game engine. But for two and three, I +would say experiment. Try some stuff + + align:start position:0% +would say experiment. Try some stuff + + + align:start position:0% +would say experiment. Try some stuff +out. By the time you hit project four, + + align:start position:0% +out. By the time you hit project four, + + + align:start position:0% +out. By the time you hit project four, +you should have some opinions about what + + align:start position:0% +you should have some opinions about what + + + align:start position:0% +you should have some opinions about what +game engine works well for you and try + + align:start position:0% +game engine works well for you and try + + + align:start position:0% +game engine works well for you and try +to get there. Try to use one you're + + align:start position:0% +to get there. Try to use one you're + + + align:start position:0% +to get there. Try to use one you're +comfortable with by then. But but + + align:start position:0% +comfortable with by then. But but + + + align:start position:0% +comfortable with by then. But but +experiment on the first + + align:start position:0% +experiment on the first + + + align:start position:0% +experiment on the first +two. No game engine is going to be + + align:start position:0% +two. No game engine is going to be + + + align:start position:0% +two. No game engine is going to be +perfect. They all have flaws. They offer + + align:start position:0% +perfect. They all have flaws. They offer + + + align:start position:0% +perfect. They all have flaws. They offer +advantages and your job is to find the + + align:start position:0% +advantages and your job is to find the + + + align:start position:0% +advantages and your job is to find the +game engine whose advantages you would + + align:start position:0% +game engine whose advantages you would + + + align:start position:0% +game engine whose advantages you would +like and whose disadvantages you can + + align:start position:0% +like and whose disadvantages you can + + + align:start position:0% +like and whose disadvantages you can +live + + align:start position:0% +live + + + align:start position:0% +live +with and that might be different for + + align:start position:0% +with and that might be different for + + + align:start position:0% +with and that might be different for +different + + align:start position:0% +different + + + align:start position:0% +different +people. All right, here we go. So, the + + align:start position:0% +people. All right, here we go. So, the + + + align:start position:0% +people. All right, here we go. So, the +most important things we're talking + + align:start position:0% +most important things we're talking + + + align:start position:0% +most important things we're talking +about for game engines, this is not an + + align:start position:0% +about for game engines, this is not an + + + align:start position:0% +about for game engines, this is not an +issue for this class. We're only + + align:start position:0% +issue for this class. We're only + + + align:start position:0% +issue for this class. We're only +recommending free game engines, but in + + align:start position:0% +recommending free game engines, but in + + + align:start position:0% +recommending free game engines, but in +general, if you're trying to pick a game + + align:start position:0% +general, if you're trying to pick a game + + + align:start position:0% +general, if you're trying to pick a game +engine or a software of any kind to help + + align:start position:0% +engine or a software of any kind to help + + + align:start position:0% +engine or a software of any kind to help +you, these are the three categories of + + align:start position:0% +you, these are the three categories of + + + align:start position:0% +you, these are the three categories of +cost, right? I call things free if you + + align:start position:0% +cost, right? I call things free if you + + + align:start position:0% +cost, right? I call things free if you +don't care about the cost. Um, if it's + + align:start position:0% +don't care about the cost. Um, if it's + + + align:start position:0% +don't care about the cost. Um, if it's +$20, it's practically free. Um, but if + + align:start position:0% +$20, it's practically free. Um, but if + + + align:start position:0% +$20, it's practically free. Um, but if +it's $1,000 and you're a college + + align:start position:0% +it's $1,000 and you're a college + + + align:start position:0% +it's $1,000 and you're a college +student, that's not free. That's + + align:start position:0% +student, that's not free. That's + + + align:start position:0% +student, that's not free. That's +painful. And if you're a corporation, + + align:start position:0% +painful. And if you're a corporation, + + + align:start position:0% +painful. And if you're a corporation, +however, $1,000 is free. So, these + + align:start position:0% +however, $1,000 is free. So, these + + + align:start position:0% +however, $1,000 is free. So, these +categories change. For us, we're talking + + align:start position:0% +categories change. For us, we're talking + + + align:start position:0% +categories change. For us, we're talking +about free. Um, impossible is, you know, + + align:start position:0% +about free. Um, impossible is, you know, + + + align:start position:0% +about free. Um, impossible is, you know, +Cry Engine or something brutal that get + + align:start position:0% +Cry Engine or something brutal that get + + + align:start position:0% +Cry Engine or something brutal that get +the source license and do everything, + + align:start position:0% +the source license and do everything, + + + align:start position:0% +the source license and do everything, +but we're not going to do that. So, this + + align:start position:0% +but we're not going to do that. So, this + + + align:start position:0% +but we're not going to do that. So, this +is the first one that actually matters + + align:start position:0% +is the first one that actually matters + + + align:start position:0% +is the first one that actually matters +is does your game have requirements that + + align:start position:0% +is does your game have requirements that + + + align:start position:0% +is does your game have requirements that +the game engine has to meet? And for the + + align:start position:0% +the game engine has to meet? And for the + + + align:start position:0% +the game engine has to meet? And for the +most part in this class, this also won't + + align:start position:0% +most part in this class, this also won't + + + align:start position:0% +most part in this class, this also won't +be true because you can choose your + + align:start position:0% +be true because you can choose your + + + align:start position:0% +be true because you can choose your +requirements based on the game engine + + align:start position:0% +requirements based on the game engine + + + align:start position:0% +requirements based on the game engine +you're choosing. And our games are + + align:start position:0% +you're choosing. And our games are + + + align:start position:0% +you're choosing. And our games are +pretty small scope. But basically, if + + align:start position:0% +pretty small scope. But basically, if + + + align:start position:0% +pretty small scope. But basically, if +you need special input, if you want to + + align:start position:0% +you need special input, if you want to + + + align:start position:0% +you need special input, if you want to +publish to iOS, if you need to, um, + + align:start position:0% +publish to iOS, if you need to, um, + + + align:start position:0% +publish to iOS, if you need to, um, +support network play, um, which you + + align:start position:0% +support network play, um, which you + + + align:start position:0% +support network play, um, which you +don't remember, um, then that might + + align:start position:0% +don't remember, um, then that might + + + align:start position:0% +don't remember, um, then that might +affect which game engine you choose. + + align:start position:0% + + + + align:start position:0% + +Um, this one is actually my biggest + + align:start position:0% +Um, this one is actually my biggest + + + align:start position:0% +Um, this one is actually my biggest +important thing. Whatever you choose for + + align:start position:0% +important thing. Whatever you choose for + + + align:start position:0% +important thing. Whatever you choose for +your game engine, and we're actually + + align:start position:0% +your game engine, and we're actually + + + align:start position:0% +your game engine, and we're actually +going to give you a short list, so it's + + align:start position:0% +going to give you a short list, so it's + + + align:start position:0% +going to give you a short list, so it's +not quite the open open free-for-all you + + align:start position:0% +not quite the open open free-for-all you + + + align:start position:0% +not quite the open open free-for-all you +might be worried about. Um, it should be + + align:start position:0% +might be worried about. Um, it should be + + + align:start position:0% +might be worried about. Um, it should be +easy to learn. And that's there's a + + align:start position:0% +easy to learn. And that's there's a + + + align:start position:0% +easy to learn. And that's there's a +couple reasons for that. Um, the main + + align:start position:0% +couple reasons for that. Um, the main + + + align:start position:0% +couple reasons for that. Um, the main +reason is simply the amount of time + + align:start position:0% +reason is simply the amount of time + + + align:start position:0% +reason is simply the amount of time +you've got. We don't have a lot of time. + + align:start position:0% +you've got. We don't have a lot of time. + + + align:start position:0% +you've got. We don't have a lot of time. +You don't want to spend time mastering a + + align:start position:0% +You don't want to spend time mastering a + + + align:start position:0% +You don't want to spend time mastering a +game engine. You want to spend time + + align:start position:0% +game engine. You want to spend time + + + align:start position:0% +game engine. You want to spend time +mastering the art of creating games. So, + + align:start position:0% +mastering the art of creating games. So, + + + align:start position:0% +mastering the art of creating games. So, +you want to pick something that's well + + align:start position:0% +you want to pick something that's well + + + align:start position:0% +you want to pick something that's well +doumented that it's got a good online + + align:start position:0% +doumented that it's got a good online + + + align:start position:0% +doumented that it's got a good online +community that's going to help you out. + + align:start position:0% +community that's going to help you out. + + + align:start position:0% +community that's going to help you out. +Um, even if you don't ask the questions, + + align:start position:0% +Um, even if you don't ask the questions, + + + align:start position:0% +Um, even if you don't ask the questions, +a big enough online community, someone's + + align:start position:0% +a big enough online community, someone's + + + align:start position:0% +a big enough online community, someone's +already asked the question you have. I + + align:start position:0% +already asked the question you have. I + + + align:start position:0% +already asked the question you have. I +suspect you're all familiar with this + + align:start position:0% +suspect you're all familiar with this + + + align:start position:0% +suspect you're all familiar with this +point. You do a search for the question + + align:start position:0% +point. You do a search for the question + + + align:start position:0% +point. You do a search for the question +you have on something and some forum + + align:start position:0% +you have on something and some forum + + + align:start position:0% +you have on something and some forum +post pops up where someone else has + + align:start position:0% +post pops up where someone else has + + + align:start position:0% +post pops up where someone else has +already asked the question you have and + + align:start position:0% +already asked the question you have and + + + align:start position:0% +already asked the question you have and +you just read the answers and think, + + align:start position:0% +you just read the answers and think, + + + align:start position:0% +you just read the answers and think, +"Yay, there was an answer." Or probably + + align:start position:0% +"Yay, there was an answer." Or probably + + + align:start position:0% +"Yay, there was an answer." Or probably +there wasn't an answer. I'll look at a + + align:start position:0% +there wasn't an answer. I'll look at a + + + align:start position:0% +there wasn't an answer. I'll look at a +couple more of those. And so you can get + + align:start position:0% +couple more of those. And so you can get + + + align:start position:0% +couple more of those. And so you can get +an idea for your game engine as to how + + align:start position:0% +an idea for your game engine as to how + + + align:start position:0% +an idea for your game engine as to how +robust the community is, how good the + + align:start position:0% +robust the community is, how good the + + + align:start position:0% +robust the community is, how good the +support is by sort of looking and seeing + + align:start position:0% +support is by sort of looking and seeing + + + align:start position:0% +support is by sort of looking and seeing +how much support there is online for + + align:start position:0% +how much support there is online for + + + align:start position:0% +how much support there is online for +it. Uh in one thing on in-house experts, + + align:start position:0% +it. Uh in one thing on in-house experts, + + + align:start position:0% +it. Uh in one thing on in-house experts, +it's very common for a team to come + + align:start position:0% +it's very common for a team to come + + + align:start position:0% +it's very common for a team to come +together and say, well, we all know this + + align:start position:0% +together and say, well, we all know this + + + align:start position:0% +together and say, well, we all know this +game engine a little bit, but but + + align:start position:0% +game engine a little bit, but but + + + align:start position:0% +game engine a little bit, but but +there's this one person on our team + + align:start position:0% +there's this one person on our team + + + align:start position:0% +there's this one person on our team +who's an expert in this other one. Um so + + align:start position:0% +who's an expert in this other one. Um so + + + align:start position:0% +who's an expert in this other one. Um so +we're going to rely on that person to + + align:start position:0% +we're going to rely on that person to + + + align:start position:0% +we're going to rely on that person to +really teach us how to do it. That only + + align:start position:0% +really teach us how to do it. That only + + + align:start position:0% +really teach us how to do it. That only +only works if that person is really + + align:start position:0% +only works if that person is really + + + align:start position:0% +only works if that person is really +willing to be a teacher. And I don't, + + align:start position:0% +willing to be a teacher. And I don't, + + + align:start position:0% +willing to be a teacher. And I don't, +it's not a bad thing if they're not, but + + align:start position:0% +it's not a bad thing if they're not, but + + + align:start position:0% +it's not a bad thing if they're not, but +don't choose their engine based on their + + align:start position:0% +don't choose their engine based on their + + + align:start position:0% +don't choose their engine based on their +expertise if they're not willing to + + align:start position:0% +expertise if they're not willing to + + + align:start position:0% +expertise if they're not willing to +really be a teacher. And what I mean by + + align:start position:0% +really be a teacher. And what I mean by + + + align:start position:0% +really be a teacher. And what I mean by +that is that that person will have to be + + align:start position:0% +that is that that person will have to be + + + align:start position:0% +that is that that person will have to be +willing to not write code a lot of the + + align:start position:0% +willing to not write code a lot of the + + + align:start position:0% +willing to not write code a lot of the +time because their time is better spent + + align:start position:0% +time because their time is better spent + + + align:start position:0% +time because their time is better spent +teaching everyone else how to write + + align:start position:0% +teaching everyone else how to write + + + align:start position:0% +teaching everyone else how to write +code. And that merely means that if you + + align:start position:0% +code. And that merely means that if you + + + align:start position:0% +code. And that merely means that if you +find yourself in that situation where + + align:start position:0% +find yourself in that situation where + + + align:start position:0% +find yourself in that situation where +you think that you are the expert in a + + align:start position:0% +you think that you are the expert in a + + + align:start position:0% +you think that you are the expert in a +particular engine and you're trying to + + align:start position:0% +particular engine and you're trying to + + + align:start position:0% +particular engine and you're trying to +get your team to use it, really think + + align:start position:0% +get your team to use it, really think + + + align:start position:0% +get your team to use it, really think +about yourself and how you're feeling + + align:start position:0% +about yourself and how you're feeling + + + align:start position:0% +about yourself and how you're feeling +about that. Make sure that you are + + align:start position:0% +about that. Make sure that you are + + + align:start position:0% +about that. Make sure that you are +willing to not dive in and write the + + align:start position:0% +willing to not dive in and write the + + + align:start position:0% +willing to not dive in and write the +code. Make sure that you're willing to + + align:start position:0% +code. Make sure that you're willing to + + + align:start position:0% +code. Make sure that you're willing to +help everyone else do it instead because + + align:start position:0% +help everyone else do it instead because + + + align:start position:0% +help everyone else do it instead because +that is going to leverage more of your + + align:start position:0% +that is going to leverage more of your + + + align:start position:0% +that is going to leverage more of your +team. On a small enough team, that's not + + align:start position:0% +team. On a small enough team, that's not + + + align:start position:0% +team. On a small enough team, that's not +true. But so, you know, two or three two + + align:start position:0% +true. But so, you know, two or three two + + + align:start position:0% +true. But so, you know, two or three two +or three people person team, you can + + align:start position:0% +or three people person team, you can + + + align:start position:0% +or three people person team, you can +probably get away with that expert. On + + align:start position:0% +probably get away with that expert. On + + + align:start position:0% +probably get away with that expert. On +an eightp person team where five of you + + align:start position:0% +an eightp person team where five of you + + + align:start position:0% +an eightp person team where five of you +are coding something, you really can't + + align:start position:0% +are coding something, you really can't + + + align:start position:0% +are coding something, you really can't +lean on that one person that heavily. + + align:start position:0% +lean on that one person that heavily. + + + align:start position:0% +lean on that one person that heavily. +You going to need to spread out the + + align:start position:0% +You going to need to spread out the + + + align:start position:0% +You going to need to spread out the +knowledge as best you can. + + align:start position:0% +knowledge as best you can. + + + align:start position:0% +knowledge as best you can. +Um, and so some game engines are easier + + align:start position:0% +Um, and so some game engines are easier + + + align:start position:0% +Um, and so some game engines are easier +to learn than others. It's not just a + + align:start position:0% +to learn than others. It's not just a + + + align:start position:0% +to learn than others. It's not just a +matter of the online support. + + align:start position:0% +matter of the online support. + + + align:start position:0% +matter of the online support. +Um, but we'll get to that in a little + + align:start position:0% +Um, but we'll get to that in a little + + + align:start position:0% +Um, but we'll get to that in a little +bit. Um, on a team programming project, + + align:start position:0% +bit. Um, on a team programming project, + + + align:start position:0% +bit. Um, on a team programming project, +and this is a personal bias of mine, and + + align:start position:0% +and this is a personal bias of mine, and + + + align:start position:0% +and this is a personal bias of mine, and +I admit that some people disagree, but I + + align:start position:0% +I admit that some people disagree, but I + + + align:start position:0% +I admit that some people disagree, but I +personally think that a strong strongly + + align:start position:0% +personally think that a strong strongly + + + align:start position:0% +personally think that a strong strongly +typed programming language is a must. + + align:start position:0% +typed programming language is a must. + + + align:start position:0% +typed programming language is a must. +If you're talking about five to eight + + align:start position:0% +If you're talking about five to eight + + + align:start position:0% +If you're talking about five to eight +programmers, there's an additional + + align:start position:0% +programmers, there's an additional + + + align:start position:0% +programmers, there's an additional +problem. Whenever I write a function and + + align:start position:0% +problem. Whenever I write a function and + + + align:start position:0% +problem. Whenever I write a function and +you're going to call my function, you + + align:start position:0% +you're going to call my function, you + + + align:start position:0% +you're going to call my function, you +have to know what the arguments are to + + align:start position:0% +have to know what the arguments are to + + + align:start position:0% +have to know what the arguments are to +know what's going to happen. And a + + align:start position:0% +know what's going to happen. And a + + + align:start position:0% +know what's going to happen. And a +strongly typed language will enforce + + align:start position:0% +strongly typed language will enforce + + + align:start position:0% +strongly typed language will enforce +that contract. It will make sure that + + align:start position:0% +that contract. It will make sure that + + + align:start position:0% +that contract. It will make sure that +we're on the same page at least a little + + align:start position:0% +we're on the same page at least a little + + + align:start position:0% +we're on the same page at least a little +bit as to what that function is doing. + + align:start position:0% +bit as to what that function is doing. + + + align:start position:0% +bit as to what that function is doing. +Um, a lot of you are probably used to + + align:start position:0% +Um, a lot of you are probably used to + + + align:start position:0% +Um, a lot of you are probably used to +MIT teaches in a lot of the early + + align:start position:0% +MIT teaches in a lot of the early + + + align:start position:0% +MIT teaches in a lot of the early +programming classes uses Python, which + + align:start position:0% +programming classes uses Python, which + + + align:start position:0% +programming classes uses Python, which +is awesome for quick work and it's + + align:start position:0% +is awesome for quick work and it's + + + align:start position:0% +is awesome for quick work and it's +awesome for a single person doing work, + + align:start position:0% +awesome for a single person doing work, + + + align:start position:0% +awesome for a single person doing work, +but it does kind of start to fall apart + + align:start position:0% +but it does kind of start to fall apart + + + align:start position:0% +but it does kind of start to fall apart +on a larger team when you have to read + + align:start position:0% +on a larger team when you have to read + + + align:start position:0% +on a larger team when you have to read +someone else's code to know what their + + align:start position:0% +someone else's code to know what their + + + align:start position:0% +someone else's code to know what their +function is doing, what the arguments + + align:start position:0% +function is doing, what the arguments + + + align:start position:0% +function is doing, what the arguments +are supposed to + + align:start position:0% +are supposed to + + + align:start position:0% +are supposed to +be. If instead you have it's strongly + + align:start position:0% +be. If instead you have it's strongly + + + align:start position:0% +be. If instead you have it's strongly +typed from the beginning, the compiler + + align:start position:0% +typed from the beginning, the compiler + + + align:start position:0% +typed from the beginning, the compiler +will enforce this communication. And + + align:start position:0% +will enforce this communication. And + + + align:start position:0% +will enforce this communication. And +we're going to talk a lot about teams + + align:start position:0% +we're going to talk a lot about teams + + + align:start position:0% +we're going to talk a lot about teams +and communication. Um, it turns out your + + align:start position:0% +and communication. Um, it turns out your + + + align:start position:0% +and communication. Um, it turns out your +code is one of the implicent methods of + + align:start position:0% +code is one of the implicent methods of + + + align:start position:0% +code is one of the implicent methods of +communication. The actual written text + + align:start position:0% +communication. The actual written text + + + align:start position:0% +communication. The actual written text +in your code is a way you talk to your + + align:start position:0% +in your code is a way you talk to your + + + align:start position:0% +in your code is a way you talk to your +team members. And a strongly typed + + align:start position:0% +team members. And a strongly typed + + + align:start position:0% +team members. And a strongly typed +language sort of forces you to keep that + + align:start position:0% +language sort of forces you to keep that + + + align:start position:0% +language sort of forces you to keep that +communication line as clear clearer than + + align:start position:0% +communication line as clear clearer than + + + align:start position:0% +communication line as clear clearer than +a weakly typed language + + align:start position:0% +a weakly typed language + + + align:start position:0% +a weakly typed language +will. Um, and again, this is one of + + align:start position:0% +will. Um, and again, this is one of + + + align:start position:0% +will. Um, and again, this is one of +those things where programmers might + + align:start position:0% +those things where programmers might + + + align:start position:0% +those things where programmers might +have battles over whether or not it's + + align:start position:0% +have battles over whether or not it's + + + align:start position:0% +have battles over whether or not it's +true, but I'm pretty confident of this + + align:start position:0% +true, but I'm pretty confident of this + + + align:start position:0% +true, but I'm pretty confident of this +one. I would say it's a noose to use a + + align:start position:0% +one. I would say it's a noose to use a + + + align:start position:0% +one. I would say it's a noose to use a +weekly type language. + + align:start position:0% + + + + align:start position:0% + +Um, we also, a lot of our game engines + + align:start position:0% +Um, we also, a lot of our game engines + + + align:start position:0% +Um, we also, a lot of our game engines +are going to be talking about + + align:start position:0% +are going to be talking about + + + align:start position:0% +are going to be talking about +C or action script or whatever. And I'm + + align:start position:0% +C or action script or whatever. And I'm + + + align:start position:0% +C or action script or whatever. And I'm +going to tell you that if you know one + + align:start position:0% +going to tell you that if you know one + + + align:start position:0% +going to tell you that if you know one +of those languages, if you already know + + align:start position:0% +of those languages, if you already know + + + align:start position:0% +of those languages, if you already know +Java, for example, it's really easy to + + align:start position:0% +Java, for example, it's really easy to + + + align:start position:0% +Java, for example, it's really easy to +transition to C#, it's pretty easy to + + align:start position:0% +transition to C#, it's pretty easy to + + + align:start position:0% +transition to C#, it's pretty easy to +trans transition to Action Script. Um, + + align:start position:0% +trans transition to Action Script. Um, + + + align:start position:0% +trans transition to Action Script. Um, +Action Script and Hacks are very + + align:start position:0% +Action Script and Hacks are very + + + align:start position:0% +Action Script and Hacks are very +similar. Um, so I would say any of those + + align:start position:0% +similar. Um, so I would say any of those + + + align:start position:0% +similar. Um, so I would say any of those +top four, you're you can trans transfer + + align:start position:0% +top four, you're you can trans transfer + + + align:start position:0% +top four, you're you can trans transfer +back and forth pretty easily. JavaScript + + align:start position:0% +back and forth pretty easily. JavaScript + + + align:start position:0% +back and forth pretty easily. JavaScript +kind of. Um but don't try to transition + + align:start position:0% +kind of. Um but don't try to transition + + + align:start position:0% +kind of. Um but don't try to transition +to C++ from those um quickly. I mean + + align:start position:0% +to C++ from those um quickly. I mean + + + align:start position:0% +to C++ from those um quickly. I mean +obviously you should someday learn C++ + + align:start position:0% +obviously you should someday learn C++ + + + align:start position:0% +obviously you should someday learn C++ +if you are consider yourself a a course + + align:start position:0% +if you are consider yourself a a course + + + align:start position:0% +if you are consider yourself a a course +six major or whatever but don't assume + + align:start position:0% +six major or whatever but don't assume + + + align:start position:0% +six major or whatever but don't assume +you can pick up C++ in a weekend because + + align:start position:0% +you can pick up C++ in a weekend because + + + align:start position:0% +you can pick up C++ in a weekend because +you already know Java. Um they're just + + align:start position:0% +you already know Java. Um they're just + + + align:start position:0% +you already know Java. Um they're just +gotchas in C++ that don't exist in those + + align:start position:0% +gotchas in C++ that don't exist in those + + + align:start position:0% +gotchas in C++ that don't exist in those +languages. Uh another important note, if + + align:start position:0% +languages. Uh another important note, if + + + align:start position:0% +languages. Uh another important note, if +you know + + align:start position:0% +you know + + + align:start position:0% +you know +Java, it + + align:start position:0% +Java, it + + + align:start position:0% +Java, it +looks it really looks like you know + + align:start position:0% +looks it really looks like you know + + + align:start position:0% +looks it really looks like you know +JavaScript. + + align:start position:0% +JavaScript. + + + align:start position:0% +JavaScript. +Um, and you kind of do, but you don't. + + align:start position:0% +Um, and you kind of do, but you don't. + + + align:start position:0% +Um, and you kind of do, but you don't. +Um, and that's not to say that you + + align:start position:0% +Um, and that's not to say that you + + + align:start position:0% +Um, and that's not to say that you +shouldn't make that transition, but be + + align:start position:0% +shouldn't make that transition, but be + + + align:start position:0% +shouldn't make that transition, but be +aware this can take a little bit longer + + align:start position:0% +aware this can take a little bit longer + + + align:start position:0% +aware this can take a little bit longer +than you think. Um, there's a lot of + + align:start position:0% +than you think. Um, there's a lot of + + + align:start position:0% +than you think. Um, there's a lot of +syntax sharing, but JavaScript is a + + align:start position:0% +syntax sharing, but JavaScript is a + + + align:start position:0% +syntax sharing, but JavaScript is a +weakly typed language that has a lot of + + align:start position:0% +weakly typed language that has a lot of + + + align:start position:0% +weakly typed language that has a lot of +weird very web specific features and and + + align:start position:0% +weird very web specific features and and + + + align:start position:0% +weird very web specific features and and +just be aware that that's not as easy a + + align:start position:0% +just be aware that that's not as easy a + + + align:start position:0% +just be aware that that's not as easy a +transition. Um, I talked about ease of + + align:start position:0% +transition. Um, I talked about ease of + + + align:start position:0% +transition. Um, I talked about ease of +uh of of understanding and learning. + + align:start position:0% +uh of of understanding and learning. + + + align:start position:0% +uh of of understanding and learning. +Actually using the engine is also very + + align:start position:0% +Actually using the engine is also very + + + align:start position:0% +Actually using the engine is also very +important. How are you going to get + + align:start position:0% +important. How are you going to get + + + align:start position:0% +important. How are you going to get +stuff done in it? Um if the engine has + + align:start position:0% +stuff done in it? Um if the engine has + + + align:start position:0% +stuff done in it? Um if the engine has +an interactive debugger that is + + align:start position:0% +an interactive debugger that is + + + align:start position:0% +an interactive debugger that is +wonderful. If it doesn't then you + + align:start position:0% +wonderful. If it doesn't then you + + + align:start position:0% +wonderful. If it doesn't then you +relying mostly on print statements and + + align:start position:0% +relying mostly on print statements and + + + align:start position:0% +relying mostly on print statements and +that's hard. Um if you've never really + + align:start position:0% +that's hard. Um if you've never really + + + align:start position:0% +that's hard. Um if you've never really +had the joy of using debugger before I + + align:start position:0% +had the joy of using debugger before I + + + align:start position:0% +had the joy of using debugger before I +recommend you try to learn because it's + + align:start position:0% +recommend you try to learn because it's + + + align:start position:0% +recommend you try to learn because it's +really extremely powerful tool. Uh we're + + align:start position:0% +really extremely powerful tool. Uh we're + + + align:start position:0% +really extremely powerful tool. Uh we're +not going to get into that detail right + + align:start position:0% +not going to get into that detail right + + + align:start position:0% +not going to get into that detail right +now. Um and source control friendly is + + align:start position:0% +now. Um and source control friendly is + + + align:start position:0% +now. Um and source control friendly is +another important one. If you're on a + + align:start position:0% +another important one. If you're on a + + + align:start position:0% +another important one. If you're on a +team with eight people, you're all going + + align:start position:0% +team with eight people, you're all going + + + align:start position:0% +team with eight people, you're all going +to be making changes. We're going to + + align:start position:0% +to be making changes. We're going to + + + align:start position:0% +to be making changes. We're going to +talk more about source control in the + + align:start position:0% +talk more about source control in the + + + align:start position:0% +talk more about source control in the +future. We're not going to go into + + align:start position:0% +future. We're not going to go into + + + align:start position:0% +future. We're not going to go into +details on that now, but basically it's + + align:start position:0% +details on that now, but basically it's + + + align:start position:0% +details on that now, but basically it's +a way for your team team to communicate + + align:start position:0% +a way for your team team to communicate + + + align:start position:0% +a way for your team team to communicate +and make sure you're all using the same + + align:start position:0% +and make sure you're all using the same + + + align:start position:0% +and make sure you're all using the same +up-to-date source code for your project. + + align:start position:0% +up-to-date source code for your project. + + + align:start position:0% +up-to-date source code for your project. +And if your engine doesn't support that, + + align:start position:0% +And if your engine doesn't support that, + + + align:start position:0% +And if your engine doesn't support that, +then you can be in trouble. Um, in the + + align:start position:0% +then you can be in trouble. Um, in the + + + align:start position:0% +then you can be in trouble. Um, in the +past, for example, um, people have + + align:start position:0% +past, for example, um, people have + + + align:start position:0% +past, for example, um, people have +talked about some of the some of the + + align:start position:0% +talked about some of the some of the + + + align:start position:0% +talked about some of the some of the +cool sort of hobbyist game engines like + + align:start position:0% +cool sort of hobbyist game engines like + + + align:start position:0% +cool sort of hobbyist game engines like +Game Maker, um, or back in the day just + + align:start position:0% +Game Maker, um, or back in the day just + + + align:start position:0% +Game Maker, um, or back in the day just +bare Flash. Um, and those are really + + align:start position:0% +bare Flash. Um, and those are really + + + align:start position:0% +bare Flash. Um, and those are really +cool tools, but they would save the + + align:start position:0% +cool tools, but they would save the + + + align:start position:0% +cool tools, but they would save the +entire project as one monolithic binary + + align:start position:0% +entire project as one monolithic binary + + + align:start position:0% +entire project as one monolithic binary +file. And so if one person makes a + + align:start position:0% +file. And so if one person makes a + + + align:start position:0% +file. And so if one person makes a +change, no one else can change the code + + align:start position:0% +change, no one else can change the code + + + align:start position:0% +change, no one else can change the code +while they're doing that because there's + + align:start position:0% +while they're doing that because there's + + + align:start position:0% +while they're doing that because there's +no way to merge our changes. Um whereas + + align:start position:0% +no way to merge our changes. Um whereas + + + align:start position:0% +no way to merge our changes. Um whereas +with code or text files or a good game + + align:start position:0% +with code or text files or a good game + + + align:start position:0% +with code or text files or a good game +engine that separates things out a + + align:start position:0% +engine that separates things out a + + + align:start position:0% +engine that separates things out a +little bit, one person can change an art + + align:start position:0% +little bit, one person can change an art + + + align:start position:0% +little bit, one person can change an art +asset while someone changes a code file + + align:start position:0% +asset while someone changes a code file + + + align:start position:0% +asset while someone changes a code file +while someone else changes yet another + + align:start position:0% +while someone else changes yet another + + + align:start position:0% +while someone else changes yet another +code file and all merges them together + + align:start position:0% +code file and all merges them together + + + align:start position:0% +code file and all merges them together +pretty pretty seamlessly. And that's + + align:start position:0% +pretty pretty seamlessly. And that's + + + align:start position:0% +pretty pretty seamlessly. And that's +what you're looking for if possible on a + + align:start position:0% +what you're looking for if possible on a + + + align:start position:0% +what you're looking for if possible on a +team + + align:start position:0% + + + + align:start position:0% + +project. Um and I talked about this + + align:start position:0% +project. Um and I talked about this + + + align:start position:0% +project. Um and I talked about this +before, but you really want a project + + align:start position:0% +before, but you really want a project + + + align:start position:0% +before, but you really want a project +that's been around a little bit. It's + + align:start position:0% +that's been around a little bit. It's + + + align:start position:0% +that's been around a little bit. It's +cool as a as a sort of a hobbyist thing + + align:start position:0% +cool as a as a sort of a hobbyist thing + + + align:start position:0% +cool as a as a sort of a hobbyist thing +or a solo project to take on something + + align:start position:0% +or a solo project to take on something + + + align:start position:0% +or a solo project to take on something +really brand new, but I think for a for + + align:start position:0% +really brand new, but I think for a for + + + align:start position:0% +really brand new, but I think for a for +a class where you're trying to get stuff + + align:start position:0% +a class where you're trying to get stuff + + + align:start position:0% +a class where you're trying to get stuff +done really really fast and you're + + align:start position:0% +done really really fast and you're + + + align:start position:0% +done really really fast and you're +working with a team, you really don't + + align:start position:0% +working with a team, you really don't + + + align:start position:0% +working with a team, you really don't +want to sort of go too far in the + + align:start position:0% +want to sort of go too far in the + + + align:start position:0% +want to sort of go too far in the +direction of of the new latest and + + align:start position:0% +direction of of the new latest and + + + align:start position:0% +direction of of the new latest and +greatest thing because you want to have + + align:start position:0% +greatest thing because you want to have + + + align:start position:0% +greatest thing because you want to have +a game engine that people have put some + + align:start position:0% +a game engine that people have put some + + + align:start position:0% +a game engine that people have put some +miles on, have tested it, and shaken out + + align:start position:0% +miles on, have tested it, and shaken out + + + align:start position:0% +miles on, have tested it, and shaken out +some of the bugs before you get to it. + + align:start position:0% + + + + align:start position:0% + +All right, those are things that I + + align:start position:0% +All right, those are things that I + + + align:start position:0% +All right, those are things that I +consider you got to have them for a game + + align:start position:0% +consider you got to have them for a game + + + align:start position:0% +consider you got to have them for a game +engine. Here's some stuff that's kind of + + align:start position:0% +engine. Here's some stuff that's kind of + + + align:start position:0% +engine. Here's some stuff that's kind of +nice. + + align:start position:0% +nice. + + + align:start position:0% +nice. +Um, yeah, it's nice to be able to easily + + align:start position:0% +Um, yeah, it's nice to be able to easily + + + align:start position:0% +Um, yeah, it's nice to be able to easily +import images and sounds and stuff like + + align:start position:0% +import images and sounds and stuff like + + + align:start position:0% +import images and sounds and stuff like +that. It's nice to be able to get the + + align:start position:0% +that. It's nice to be able to get the + + + align:start position:0% +that. It's nice to be able to get the +source code to the engine. Um, but not + + align:start position:0% +source code to the engine. Um, but not + + + align:start position:0% +source code to the engine. Um, but not +essential if the engine's well + + align:start position:0% +essential if the engine's well + + + align:start position:0% +essential if the engine's well +documented. Uh, let's see. It's nice if + + align:start position:0% +documented. Uh, let's see. It's nice if + + + align:start position:0% +documented. Uh, let's see. It's nice if +you have an integrated development + + align:start position:0% +you have an integrated development + + + align:start position:0% +you have an integrated development +environment that can help you with + + align:start position:0% +environment that can help you with + + + align:start position:0% +environment that can help you with +autocomp completion of various functions + + align:start position:0% +autocomp completion of various functions + + + align:start position:0% +autocomp completion of various functions +and really help you along with your + + align:start position:0% +and really help you along with your + + + align:start position:0% +and really help you along with your +development. That's definitely nice, but + + align:start position:0% +development. That's definitely nice, but + + + align:start position:0% +development. That's definitely nice, but +not necessary. And then finally, so you + + align:start position:0% +not necessary. And then finally, so you + + + align:start position:0% +not necessary. And then finally, so you +like an editor of some kind. If I want + + align:start position:0% +like an editor of some kind. If I want + + + align:start position:0% +like an editor of some kind. If I want +to lay out my levels in some way, is it + + align:start position:0% +to lay out my levels in some way, is it + + + align:start position:0% +to lay out my levels in some way, is it +is there a graphical editor for me to do + + align:start position:0% +is there a graphical editor for me to do + + + align:start position:0% +is there a graphical editor for me to do +that? That's certainly nice. And a + + align:start position:0% +that? That's certainly nice. And a + + + align:start position:0% +that? That's certainly nice. And a +profiler that would tell me where my + + align:start position:0% +profiler that would tell me where my + + + align:start position:0% +profiler that would tell me where my +game is slow, that's also nice. But + + align:start position:0% +game is slow, that's also nice. But + + + align:start position:0% +game is slow, that's also nice. But +without these things, you can probably + + align:start position:0% +without these things, you can probably + + + align:start position:0% +without these things, you can probably +get + + align:start position:0% + + + + align:start position:0% + +by. Um, bells and whistles. This is + + align:start position:0% +by. Um, bells and whistles. This is + + + align:start position:0% +by. Um, bells and whistles. This is +actually relatively unimportant. + + align:start position:0% +actually relatively unimportant. + + + align:start position:0% +actually relatively unimportant. +um especially for a small project + + align:start position:0% +um especially for a small project + + + align:start position:0% +um especially for a small project +prototype style stuff that we're going + + align:start position:0% +prototype style stuff that we're going + + + align:start position:0% +prototype style stuff that we're going +to be talking about for the most part + + align:start position:0% +to be talking about for the most part + + + align:start position:0% +to be talking about for the most part +you don't need all the fancy stuff like + + align:start position:0% +you don't need all the fancy stuff like + + + align:start position:0% +you don't need all the fancy stuff like +particle systems and shaders and physics + + align:start position:0% +particle systems and shaders and physics + + + align:start position:0% +particle systems and shaders and physics +and all that stuff you might use physics + + align:start position:0% +and all that stuff you might use physics + + + align:start position:0% +and all that stuff you might use physics +in this class but yeah be careful so + + align:start position:0% +in this class but yeah be careful so + + + align:start position:0% +in this class but yeah be careful so +that's one of the things you don't need + + align:start position:0% +that's one of the things you don't need + + + align:start position:0% +that's one of the things you don't need +that stuff in your game engine for most + + align:start position:0% +that stuff in your game engine for most + + + align:start position:0% +that stuff in your game engine for most +small games at least in the scope of + + align:start position:0% +small games at least in the scope of + + + align:start position:0% +small games at least in the scope of +this class um these are things that I + + align:start position:0% +this class um these are things that I + + + align:start position:0% +this class um these are things that I +really don't care about uh scripting + + align:start position:0% +really don't care about uh scripting + + + align:start position:0% +really don't care about uh scripting +languages that your designer might use + + align:start position:0% +languages that your designer might use + + + align:start position:0% +languages that your designer might use +why is your designer not writing code in + + align:start position:0% +why is your designer not writing code in + + + align:start position:0% +why is your designer not writing code in +your strongly typed language I never + + align:start position:0% +your strongly typed language I never + + + align:start position:0% +your strongly typed language I never +understood that one Um, some designers + + align:start position:0% +understood that one Um, some designers + + + align:start position:0% +understood that one Um, some designers +are afraid of writing code, but + + align:start position:0% +are afraid of writing code, but + + + align:start position:0% +are afraid of writing code, but +hopefully in this class you're at least + + align:start position:0% +hopefully in this class you're at least + + + align:start position:0% +hopefully in this class you're at least +willing to try writing some + + align:start position:0% +willing to try writing some + + + align:start position:0% +willing to try writing some +code. Um, and then finally, just because + + align:start position:0% +code. Um, and then finally, just because + + + align:start position:0% +code. Um, and then finally, just because +someone has made a beautiful game in a + + align:start position:0% +someone has made a beautiful game in a + + + align:start position:0% +someone has made a beautiful game in a +game engine has no bearing on whether or + + align:start position:0% +game engine has no bearing on whether or + + + align:start position:0% +game engine has no bearing on whether or +not your game will be beautiful in that + + align:start position:0% +not your game will be beautiful in that + + + align:start position:0% +not your game will be beautiful in that +game engine. Um, the vast majority of + + align:start position:0% +game engine. Um, the vast majority of + + + align:start position:0% +game engine. Um, the vast majority of +the time a game engine or a game built + + align:start position:0% +the time a game engine or a game built + + + align:start position:0% +the time a game engine or a game built +in a game engine is beautiful because + + align:start position:0% +in a game engine is beautiful because + + + align:start position:0% +in a game engine is beautiful because +they have a really good art team. Um, + + align:start position:0% +they have a really good art team. Um, + + + align:start position:0% +they have a really good art team. Um, +and we don't have a really good art team + + align:start position:0% +and we don't have a really good art team + + + align:start position:0% +and we don't have a really good art team +here. We don't have the time to do that + + align:start position:0% +here. We don't have the time to do that + + + align:start position:0% +here. We don't have the time to do that +and we don't have the resources to do + + align:start position:0% +and we don't have the resources to do + + + align:start position:0% +and we don't have the resources to do +it. So your shouldn't measure your game + + align:start position:0% +it. So your shouldn't measure your game + + + align:start position:0% +it. So your shouldn't measure your game +up against the beautiful AAA games. You + + align:start position:0% +up against the beautiful AAA games. You + + + align:start position:0% +up against the beautiful AAA games. You +should be measuring your games up + + align:start position:0% +should be measuring your games up + + + align:start position:0% +should be measuring your games up +against some indie quick prototype type + + align:start position:0% +against some indie quick prototype type + + + align:start position:0% +against some indie quick prototype type +of + + align:start position:0% + + + + align:start position:0% + +games. All right. + + align:start position:0% +games. All right. + + + align:start position:0% +games. All right. +So Flixel is a thing we've been + + align:start position:0% +So Flixel is a thing we've been + + + align:start position:0% +So Flixel is a thing we've been +recommending for many many years. This + + align:start position:0% +recommending for many many years. This + + + align:start position:0% +recommending for many many years. This +is a game engine that that is the game + + align:start position:0% +is a game engine that that is the game + + + align:start position:0% +is a game engine that that is the game +engine that is easiest has the quickest + + align:start position:0% +engine that is easiest has the quickest + + + align:start position:0% +engine that is easiest has the quickest +learning curve I've seen. Uh it gets + + align:start position:0% +learning curve I've seen. Uh it gets + + + align:start position:0% +learning curve I've seen. Uh it gets +everything done. It's very quick uh to + + align:start position:0% +everything done. It's very quick uh to + + + align:start position:0% +everything done. It's very quick uh to +to turn learn to use and it runs on the + + align:start position:0% +to turn learn to use and it runs on the + + + align:start position:0% +to turn learn to use and it runs on the +web. Great. That's pretty good easy + + align:start position:0% +web. Great. That's pretty good easy + + + align:start position:0% +web. Great. That's pretty good easy +stuff. Um one of the it was developed by + + align:start position:0% +stuff. Um one of the it was developed by + + + align:start position:0% +stuff. Um one of the it was developed by +Adam Atomic for a game called Cannibal. + + align:start position:0% +Adam Atomic for a game called Cannibal. + + + align:start position:0% +Adam Atomic for a game called Cannibal. +You see up there um the sort of the + + align:start position:0% +You see up there um the sort of the + + + align:start position:0% +You see up there um the sort of the +thing the game that as far as I know + + align:start position:0% +thing the game that as far as I know + + + align:start position:0% +thing the game that as far as I know +sort of popularized the Infinite Runner + + align:start position:0% +sort of popularized the Infinite Runner + + + align:start position:0% +sort of popularized the Infinite Runner +genre uh which we've seen clone after + + align:start position:0% +genre uh which we've seen clone after + + + align:start position:0% +genre uh which we've seen clone after +clone after clone of but I believe this + + align:start position:0% +clone after clone of but I believe this + + + align:start position:0% +clone after clone of but I believe this +is at least where it entered my + + align:start position:0% +is at least where it entered my + + + align:start position:0% +is at least where it entered my +consciousness and therefore it must be + + align:start position:0% +consciousness and therefore it must be + + + align:start position:0% +consciousness and therefore it must be +the where it came into the world. Right. + + align:start position:0% +the where it came into the world. Right. + + + align:start position:0% +the where it came into the world. Right. +But anyway, um the cool thing about it + + align:start position:0% +But anyway, um the cool thing about it + + + align:start position:0% +But anyway, um the cool thing about it +is it's got a very very simple + + align:start position:0% +is it's got a very very simple + + + align:start position:0% +is it's got a very very simple +object-oriented um state-based system. + + align:start position:0% +object-oriented um state-based system. + + + align:start position:0% +object-oriented um state-based system. +It's really really good for 2D sprite + + align:start position:0% +It's really really good for 2D sprite + + + align:start position:0% +It's really really good for 2D sprite +stuff. Um in last year, we had a bunch + + align:start position:0% +stuff. Um in last year, we had a bunch + + + align:start position:0% +stuff. Um in last year, we had a bunch +of game engines for people to try. By + + align:start position:0% +of game engines for people to try. By + + + align:start position:0% +of game engines for people to try. By +the end, pretty much everyone just used + + align:start position:0% +the end, pretty much everyone just used + + + align:start position:0% +the end, pretty much everyone just used +Fixel because it was easier to use. And + + align:start position:0% +Fixel because it was easier to use. And + + + align:start position:0% +Fixel because it was easier to use. And +this is kind of says it all to me. Even + + align:start position:0% +this is kind of says it all to me. Even + + + align:start position:0% +this is kind of says it all to me. Even +if you haven't used action script, the + + align:start position:0% +if you haven't used action script, the + + + align:start position:0% +if you haven't used action script, the +learning curve on Flixel is awesome. + + align:start position:0% +learning curve on Flixel is awesome. + + + align:start position:0% +learning curve on Flixel is awesome. +um you'll spend a day or two staring at + + align:start position:0% +um you'll spend a day or two staring at + + + align:start position:0% +um you'll spend a day or two staring at +it and then you'll know every most of + + align:start position:0% +it and then you'll know every most of + + + align:start position:0% +it and then you'll know every most of +everything there is to know and you'll + + align:start position:0% +everything there is to know and you'll + + + align:start position:0% +everything there is to know and you'll +just be able to do stuff. You won't be + + align:start position:0% +just be able to do stuff. You won't be + + + align:start position:0% +just be able to do stuff. You won't be +able to do all the cool awesome stuff + + align:start position:0% +able to do all the cool awesome stuff + + + align:start position:0% +able to do all the cool awesome stuff +other game engines will let you do, but + + align:start position:0% +other game engines will let you do, but + + + align:start position:0% +other game engines will let you do, but +you'll be able to do pretty much + + align:start position:0% +you'll be able to do pretty much + + + align:start position:0% +you'll be able to do pretty much +everything you'll need to do on the + + align:start position:0% +everything you'll need to do on the + + + align:start position:0% +everything you'll need to do on the +scale and scope of games you're looking + + align:start position:0% +scale and scope of games you're looking + + + align:start position:0% +scale and scope of games you're looking +at in this + + align:start position:0% +at in this + + + align:start position:0% +at in this +class. + + align:start position:0% +class. + + + align:start position:0% +class. +Um let's see. Doesn't so good at guey. + + align:start position:0% +Um let's see. Doesn't so good at guey. + + + align:start position:0% +Um let's see. Doesn't so good at guey. +Um, if you want a fancy guey, lists and + + align:start position:0% +Um, if you want a fancy guey, lists and + + + align:start position:0% +Um, if you want a fancy guey, lists and +lots of text and buttons and sliders and + + align:start position:0% +lots of text and buttons and sliders and + + + align:start position:0% +lots of text and buttons and sliders and +stuff, it's kind of a pain to code that + + align:start position:0% +stuff, it's kind of a pain to code that + + + align:start position:0% +stuff, it's kind of a pain to code that +up. + + align:start position:0% +up. + + + align:start position:0% +up. +Um, right. So, Flickle is also + + align:start position:0% +Um, right. So, Flickle is also + + + align:start position:0% +Um, right. So, Flickle is also +unfortunately in its current form kind + + align:start position:0% +unfortunately in its current form kind + + + align:start position:0% +unfortunately in its current form kind +of in an end of life cycle and I've been + + align:start position:0% +of in an end of life cycle and I've been + + + align:start position:0% +of in an end of life cycle and I've been +saying that for two or three years now + + align:start position:0% +saying that for two or three years now + + + align:start position:0% +saying that for two or three years now +and it's still holding on because Flash + + align:start position:0% +and it's still holding on because Flash + + + align:start position:0% +and it's still holding on because Flash +is still holding on. Adobe tries trying + + align:start position:0% +is still holding on. Adobe tries trying + + + align:start position:0% +is still holding on. Adobe tries trying +to sort of get out of the business of + + align:start position:0% +to sort of get out of the business of + + + align:start position:0% +to sort of get out of the business of +maintaining Flash as a web development + + align:start position:0% +maintaining Flash as a web development + + + align:start position:0% +maintaining Flash as a web development +place. Um, and not really sure why. + + align:start position:0% +place. Um, and not really sure why. + + + align:start position:0% +place. Um, and not really sure why. +Apparently, Adobe decided a while back + + align:start position:0% +Apparently, Adobe decided a while back + + + align:start position:0% +Apparently, Adobe decided a while back +that HTML 5 was the future. Um, but it's + + align:start position:0% +that HTML 5 was the future. Um, but it's + + + align:start position:0% +that HTML 5 was the future. Um, but it's +been four or five years now and HTML 5 + + align:start position:0% +been four or five years now and HTML 5 + + + align:start position:0% +been four or five years now and HTML 5 +is still not the + + align:start position:0% +is still not the + + + align:start position:0% +is still not the +future. In the meantime, um, we're sort + + align:start position:0% +future. In the meantime, um, we're sort + + + align:start position:0% +future. In the meantime, um, we're sort +of hanging on with Flash and the + + align:start position:0% +of hanging on with Flash and the + + + align:start position:0% +of hanging on with Flash and the +occasional JavaScript HTML 5 thing. Um, + + align:start position:0% +occasional JavaScript HTML 5 thing. Um, + + + align:start position:0% +occasional JavaScript HTML 5 thing. Um, +I suspect it was actually more of a + + align:start position:0% +I suspect it was actually more of a + + + align:start position:0% +I suspect it was actually more of a +financial thing than any actual HTML 5 + + align:start position:0% +financial thing than any actual HTML 5 + + + align:start position:0% +financial thing than any actual HTML 5 +preference thing. But anyway, we're + + align:start position:0% +preference thing. But anyway, we're + + + align:start position:0% +preference thing. But anyway, we're +trying to get out of Flicks a little bit + + align:start position:0% +trying to get out of Flicks a little bit + + + align:start position:0% +trying to get out of Flicks a little bit +in the long term because Flash is going + + align:start position:0% +in the long term because Flash is going + + + align:start position:0% +in the long term because Flash is going +to be a dying platform pretty soon. + + align:start position:0% +to be a dying platform pretty soon. + + + align:start position:0% +to be a dying platform pretty soon. +Can can I just add something to that? + + align:start position:0% +Can can I just add something to that? + + + align:start position:0% +Can can I just add something to that? +Please + + align:start position:0% +Please + + + align:start position:0% +Please +stand near me because I have a + + align:start position:0% +stand near me because I have a + + + align:start position:0% +stand near me because I have a +microphone. Okay. All right. I'll stand + + align:start position:0% +microphone. Okay. All right. I'll stand + + + align:start position:0% +microphone. Okay. All right. I'll stand +right next to him so so the mic can pick + + align:start position:0% +right next to him so so the mic can pick + + + align:start position:0% +right next to him so so the mic can pick +up. Uh one thing to keep in mind um + + align:start position:0% +up. Uh one thing to keep in mind um + + + align:start position:0% +up. Uh one thing to keep in mind um +there are free versions of uh of the + + align:start position:0% +there are free versions of uh of the + + + align:start position:0% +there are free versions of uh of the +Adobe compiler for Flash called Flex uh + + align:start position:0% +Adobe compiler for Flash called Flex uh + + + align:start position:0% +Adobe compiler for Flash called Flex uh +that you can download for Linux, Mac, + + align:start position:0% +that you can download for Linux, Mac, + + + align:start position:0% +that you can download for Linux, Mac, +and and PC. However, there is also this + + align:start position:0% +and and PC. However, there is also this + + + align:start position:0% +and and PC. However, there is also this +licensed version which uh you can + + align:start position:0% +licensed version which uh you can + + + align:start position:0% +licensed version which uh you can +download for like a 30-day trial called + + align:start position:0% +download for like a 30-day trial called + + + align:start position:0% +download for like a 30-day trial called +Flash Builder. Um, unfortunately for uh + + align:start position:0% +Flash Builder. Um, unfortunately for uh + + + align:start position:0% +Flash Builder. Um, unfortunately for uh +for Mac users in particular, if you want + + align:start position:0% +for Mac users in particular, if you want + + + align:start position:0% +for Mac users in particular, if you want +to get one of those, uh, if you want to + + align:start position:0% +to get one of those, uh, if you want to + + + align:start position:0% +to get one of those, uh, if you want to +get those, I use it. I like I like + + align:start position:0% +get those, I use it. I like I like + + + align:start position:0% +get those, I use it. I like I like +writing code in it. But as soon as that + + align:start position:0% +writing code in it. But as soon as that + + + align:start position:0% +writing code in it. But as soon as that +30-day free trial is over, you are on an + + align:start position:0% +30-day free trial is over, you are on an + + + align:start position:0% +30-day free trial is over, you are on an +annual subscription, paying Adobe money + + align:start position:0% +annual subscription, paying Adobe money + + + align:start position:0% +annual subscription, paying Adobe money +every year. Uh, so free with an + + align:start position:0% +every year. Uh, so free with an + + + align:start position:0% +every year. Uh, so free with an +asterisk. uh if you want to if you want + + align:start position:0% +asterisk. uh if you want to if you want + + + align:start position:0% +asterisk. uh if you want to if you want +to do free development on a Mac uh uh uh + + align:start position:0% +to do free development on a Mac uh uh uh + + + align:start position:0% +to do free development on a Mac uh uh uh +and um and use Flixel, be very very + + align:start position:0% +and um and use Flixel, be very very + + + align:start position:0% +and um and use Flixel, be very very +careful and use this upcoming exercise + + align:start position:0% +careful and use this upcoming exercise + + + align:start position:0% +careful and use this upcoming exercise +to actually ensure that the things that + + align:start position:0% +to actually ensure that the things that + + + align:start position:0% +to actually ensure that the things that +you're downloading and the things that + + align:start position:0% +you're downloading and the things that + + + align:start position:0% +you're downloading and the things that +you're signing up for are actually free + + align:start position:0% +you're signing up for are actually free + + + align:start position:0% +you're signing up for are actually free +and not free for the first 30 days. + + align:start position:0% +and not free for the first 30 days. + + + align:start position:0% +and not free for the first 30 days. +Okay. Um, for PC users, you have the + + align:start position:0% +Okay. Um, for PC users, you have the + + + align:start position:0% +Okay. Um, for PC users, you have the +advantage of using uh Flash Develop, I + + align:start position:0% +advantage of using uh Flash Develop, I + + + align:start position:0% +advantage of using uh Flash Develop, I +believe that's that's what it's called, + + align:start position:0% +believe that's that's what it's called, + + + align:start position:0% +believe that's that's what it's called, +which is actually a a a tool that you + + align:start position:0% +which is actually a a a tool that you + + + align:start position:0% +which is actually a a a tool that you +can get with uh without having to pay + + align:start position:0% +can get with uh without having to pay + + + align:start position:0% +can get with uh without having to pay +for it. Uh, for Linux, uh, you are + + align:start position:0% +for it. Uh, for Linux, uh, you are + + + align:start position:0% +for it. Uh, for Linux, uh, you are +pretty much stuck to using command line + + align:start position:0% +pretty much stuck to using command line + + + align:start position:0% +pretty much stuck to using command line +compilers. Uh, and if you and you want + + align:start position:0% +compilers. Uh, and if you and you want + + + align:start position:0% +compilers. Uh, and if you and you want +if you really want to do free + + align:start position:0% +if you really want to do free + + + align:start position:0% +if you really want to do free +development on a Mac, you're also using + + align:start position:0% +development on a Mac, you're also using + + + align:start position:0% +development on a Mac, you're also using +command line. But there's all kinds of + + align:start position:0% +command line. But there's all kinds of + + + align:start position:0% +command line. But there's all kinds of +clever things that you can do with text + + align:start position:0% +clever things that you can do with text + + + align:start position:0% +clever things that you can do with text +editors to sort of make that a little + + align:start position:0% +editors to sort of make that a little + + + align:start position:0% +editors to sort of make that a little +bit more comfortable. So, just keep that + + align:start position:0% +bit more comfortable. So, just keep that + + + align:start position:0% +bit more comfortable. So, just keep that +in mind. That's another reason why Flix + + align:start position:0% +in mind. That's another reason why Flix + + + align:start position:0% +in mind. That's another reason why Flix +is is now our number one choice nowadays + + align:start position:0% +is is now our number one choice nowadays + + + align:start position:0% +is is now our number one choice nowadays +is because Adobe is really trying to + + align:start position:0% +is because Adobe is really trying to + + + align:start position:0% +is because Adobe is really trying to +squeeze money out of everybody, + + align:start position:0% +squeeze money out of everybody, + + + align:start position:0% +squeeze money out of everybody, +including students. Adobe's insane. + + align:start position:0% +including students. Adobe's insane. + + + align:start position:0% +including students. Adobe's insane. +Well, one can't blame them for trying to + + align:start position:0% +Well, one can't blame them for trying to + + + align:start position:0% +Well, one can't blame them for trying to +make a little bit of money. However, + + align:start position:0% +make a little bit of money. However, + + + align:start position:0% +make a little bit of money. However, +it's no longer as attractive as it used + + align:start position:0% +it's no longer as attractive as it used + + + align:start position:0% +it's no longer as attractive as it used +to be. That's certainly true. Um, Unity + + align:start position:0% +to be. That's certainly true. Um, Unity + + + align:start position:0% +to be. That's certainly true. Um, Unity +is the next one on our list that we've + + align:start position:0% +is the next one on our list that we've + + + align:start position:0% +is the next one on our list that we've +had good success with. U, it's actually + + align:start position:0% +had good success with. U, it's actually + + + align:start position:0% +had good success with. U, it's actually +intent mostly it's a pretty fullfeatured + + align:start position:0% +intent mostly it's a pretty fullfeatured + + + align:start position:0% +intent mostly it's a pretty fullfeatured +lang uh language, pretty fullfeatured + + align:start position:0% +lang uh language, pretty fullfeatured + + + align:start position:0% +lang uh language, pretty fullfeatured +game engine. It's got all the bells and + + align:start position:0% +game engine. It's got all the bells and + + + align:start position:0% +game engine. It's got all the bells and +whistles you could want. um it's a + + align:start position:0% +whistles you could want. um it's a + + + align:start position:0% +whistles you could want. um it's a +little bit dangerous to use it because + + align:start position:0% +little bit dangerous to use it because + + + align:start position:0% +little bit dangerous to use it because +it has all the bells and whistles you + + align:start position:0% +it has all the bells and whistles you + + + align:start position:0% +it has all the bells and whistles you +could want and you should probably only + + align:start position:0% +could want and you should probably only + + + align:start position:0% +could want and you should probably only +use some bells and not the whistles and + + align:start position:0% +use some bells and not the whistles and + + + align:start position:0% +use some bells and not the whistles and +whatever, right? You you be very careful + + align:start position:0% +whatever, right? You you be very careful + + + align:start position:0% +whatever, right? You you be very careful +and judicious in your use of the + + align:start position:0% +and judicious in your use of the + + + align:start position:0% +and judicious in your use of the +features because the tinker toy model of + + align:start position:0% +features because the tinker toy model of + + + align:start position:0% +features because the tinker toy model of +only do what the engine lets you do is a + + align:start position:0% +only do what the engine lets you do is a + + + align:start position:0% +only do what the engine lets you do is a +little bit dangerous because you know it + + align:start position:0% +little bit dangerous because you know it + + + align:start position:0% +little bit dangerous because you know it +lets you do pretty much everything. So + + align:start position:0% +lets you do pretty much everything. So + + + align:start position:0% +lets you do pretty much everything. So +you have to be very careful about which + + align:start position:0% +you have to be very careful about which + + + align:start position:0% +you have to be very careful about which +features you choose to use. Um however, + + align:start position:0% +features you choose to use. Um however, + + + align:start position:0% +features you choose to use. Um however, +it's great. It's free. It does a whole + + align:start position:0% +it's great. It's free. It does a whole + + + align:start position:0% +it's great. It's free. It does a whole +bunch of neat stuff. Um there are paid + + align:start position:0% +bunch of neat stuff. Um there are paid + + + align:start position:0% +bunch of neat stuff. Um there are paid +versions but but you don't you won't + + align:start position:0% +versions but but you don't you won't + + + align:start position:0% +versions but but you don't you won't +need them for the class certainly. Um I + + align:start position:0% +need them for the class certainly. Um I + + + align:start position:0% +need them for the class certainly. Um I +call these disads. Uh 3D is harder than + + align:start position:0% +call these disads. Uh 3D is harder than + + + align:start position:0% +call these disads. Uh 3D is harder than +2D. Um and I 3D is at least three times + + align:start position:0% +2D. Um and I 3D is at least three times + + + align:start position:0% +2D. Um and I 3D is at least three times +as hard as 2D really. It's it's it's + + align:start position:0% +as hard as 2D really. It's it's it's + + + align:start position:0% +as hard as 2D really. It's it's it's +rough. If you've never done 3D before, + + align:start position:0% +rough. If you've never done 3D before, + + + align:start position:0% +rough. If you've never done 3D before, +it takes a while to get your head into + + align:start position:0% +it takes a while to get your head into + + + align:start position:0% +it takes a while to get your head into +it. Um even if you're doing a 2D game in + + align:start position:0% +it. Um even if you're doing a 2D game in + + + align:start position:0% +it. Um even if you're doing a 2D game in +Unity, sometimes you have to think in 3D + + align:start position:0% +Unity, sometimes you have to think in 3D + + + align:start position:0% +Unity, sometimes you have to think in 3D +a little bit, which makes it a little + + align:start position:0% +a little bit, which makes it a little + + + align:start position:0% +a little bit, which makes it a little +bit harder to use. On the other hand, + + align:start position:0% +bit harder to use. On the other hand, + + + align:start position:0% +bit harder to use. On the other hand, +um, Unity does have this nice editor, + + align:start position:0% +um, Unity does have this nice editor, + + + align:start position:0% +um, Unity does have this nice editor, +and it's possible for a non-programmer + + align:start position:0% +and it's possible for a non-programmer + + + align:start position:0% +and it's possible for a non-programmer +to to get some stuff done in Unity in a + + align:start position:0% +to to get some stuff done in Unity in a + + + align:start position:0% +to to get some stuff done in Unity in a +way that's not possible in others. You + + align:start position:0% +way that's not possible in others. You + + + align:start position:0% +way that's not possible in others. You +spend more time learning the guey, but + + align:start position:0% +spend more time learning the guey, but + + + align:start position:0% +spend more time learning the guey, but +you can actually get some more things + + align:start position:0% +you can actually get some more things + + + align:start position:0% +you can actually get some more things +done. So, it's an interesting little + + align:start position:0% +done. So, it's an interesting little + + + align:start position:0% +done. So, it's an interesting little +trade-off there. Um, it is also again + + align:start position:0% +trade-off there. Um, it is also again + + + align:start position:0% +trade-off there. Um, it is also again +not good at guey work. Um, they're + + align:start position:0% +not good at guey work. Um, they're + + + align:start position:0% +not good at guey work. Um, they're +starting to to address that a little + + align:start position:0% +starting to to address that a little + + + align:start position:0% +starting to to address that a little +bit, but it's hard. You have to kind of + + align:start position:0% +bit, but it's hard. You have to kind of + + + align:start position:0% +bit, but it's hard. You have to kind of +handcode your buttons a little bit + + align:start position:0% +handcode your buttons a little bit + + + align:start position:0% +handcode your buttons a little bit +sometimes. Um, that is improving as I + + align:start position:0% +sometimes. Um, that is improving as I + + + align:start position:0% +sometimes. Um, that is improving as I +say, but it's not quite there yet. + + align:start position:0% +say, but it's not quite there yet. + + + align:start position:0% +say, but it's not quite there yet. +um it suffers a little bit from the + + align:start position:0% +um it suffers a little bit from the + + + align:start position:0% +um it suffers a little bit from the +problem of merging. Unity uses um + + align:start position:0% +problem of merging. Unity uses um + + + align:start position:0% +problem of merging. Unity uses um +particular objects that you really wish + + align:start position:0% +particular objects that you really wish + + + align:start position:0% +particular objects that you really wish +you could merge as just their text files + + align:start position:0% +you could merge as just their text files + + + align:start position:0% +you could merge as just their text files +or code, but uh you have a whole scene + + align:start position:0% +or code, but uh you have a whole scene + + + align:start position:0% +or code, but uh you have a whole scene +of objects, for example, and only one + + align:start position:0% +of objects, for example, and only one + + + align:start position:0% +of objects, for example, and only one +person can can really work with it at a + + align:start position:0% +person can can really work with it at a + + + align:start position:0% +person can can really work with it at a +time unless you're really very careful. + + align:start position:0% +time unless you're really very careful. + + + align:start position:0% +time unless you're really very careful. +So when you're using Unity, you have to + + align:start position:0% +So when you're using Unity, you have to + + + align:start position:0% +So when you're using Unity, you have to +be extra careful with your team and make + + align:start position:0% +be extra careful with your team and make + + + align:start position:0% +be extra careful with your team and make +sure that no people aren't messing with + + align:start position:0% +sure that no people aren't messing with + + + align:start position:0% +sure that no people aren't messing with +the same files at the same time. The + + align:start position:0% +the same files at the same time. The + + + align:start position:0% +the same files at the same time. The +code, however, works the way you want it + + align:start position:0% +code, however, works the way you want it + + + align:start position:0% +code, however, works the way you want it +to and source control works fine. So + + align:start position:0% +to and source control works fine. So + + + align:start position:0% +to and source control works fine. So +it's you got to be careful, but it's you + + align:start position:0% +it's you got to be careful, but it's you + + + align:start position:0% +it's you got to be careful, but it's you +can work around it. + + align:start position:0% + + + + align:start position:0% + +Um, moving on to the ones that, you + + align:start position:0% +Um, moving on to the ones that, you + + + align:start position:0% +Um, moving on to the ones that, you +know, we want some of you to practice + + align:start position:0% +know, we want some of you to practice + + + align:start position:0% +know, we want some of you to practice +with these, but uh, oops, that's the + + align:start position:0% +with these, but uh, oops, that's the + + + align:start position:0% +with these, but uh, oops, that's the +wrong one. I left a slide in I shouldn't + + align:start position:0% + + + + align:start position:0% + +have. I will ignore that. + + align:start position:0% + + + + align:start position:0% + +Um, let me see if I can find it + + align:start position:0% +Um, let me see if I can find it + + + align:start position:0% +Um, let me see if I can find it +here. All right. Apparently, I did not + + align:start position:0% +here. All right. Apparently, I did not + + + align:start position:0% +here. All right. Apparently, I did not +include the slides I thought I included + + align:start position:0% +include the slides I thought I included + + + align:start position:0% +include the slides I thought I included +about the two other game engines. So + + align:start position:0% +about the two other game engines. So + + + align:start position:0% +about the two other game engines. So +I'll talk about those instead. So + + align:start position:0% +I'll talk about those instead. So + + + align:start position:0% +I'll talk about those instead. So +there's another engine called hax flexel + + align:start position:0% +there's another engine called hax flexel + + + align:start position:0% +there's another engine called hax flexel +which is a sort of a port of flexel to a + + align:start position:0% +which is a sort of a port of flexel to a + + + align:start position:0% +which is a sort of a port of flexel to a +language called hax. Um this is an + + align:start position:0% +language called hax. Um this is an + + + align:start position:0% +language called hax. Um this is an +engine that we have not used yet. Um + + align:start position:0% +engine that we have not used yet. Um + + + align:start position:0% +engine that we have not used yet. Um +we've looked over a little bit and it + + align:start position:0% +we've looked over a little bit and it + + + align:start position:0% +we've looked over a little bit and it +certainly looks very promising and it's + + align:start position:0% +certainly looks very promising and it's + + + align:start position:0% +certainly looks very promising and it's +using the very same flexel style. It is + + align:start position:0% +using the very same flexel style. It is + + + align:start position:0% +using the very same flexel style. It is +however using an interesting language + + align:start position:0% +however using an interesting language + + + align:start position:0% +however using an interesting language +named hack which is mostly based on + + align:start position:0% +named hack which is mostly based on + + + align:start position:0% +named hack which is mostly based on +action script but has some java and c# + + align:start position:0% +action script but has some java and c# + + + align:start position:0% +action script but has some java and c# +like features to it. Um it does some + + align:start position:0% +like features to it. Um it does some + + + align:start position:0% +like features to it. Um it does some +crazy stuff though so it might be a + + align:start position:0% +crazy stuff though so it might be a + + + align:start position:0% +crazy stuff though so it might be a +little bit interesting to use. Um, hacks + + align:start position:0% +little bit interesting to use. Um, hacks + + + align:start position:0% +little bit interesting to use. Um, hacks +compiles down to a language of your + + align:start position:0% +compiles down to a language of your + + + align:start position:0% +compiles down to a language of your +choice which it then compiles. So for + + align:start position:0% +choice which it then compiles. So for + + + align:start position:0% +choice which it then compiles. So for +example, if you want to export your + + align:start position:0% +example, if you want to export your + + + align:start position:0% +example, if you want to export your +hacks to flash, you'll com you'll + + align:start position:0% +hacks to flash, you'll com you'll + + + align:start position:0% +hacks to flash, you'll com you'll +compile your hacks to action script + + align:start position:0% +compile your hacks to action script + + + align:start position:0% +compile your hacks to action script +which will then get compiled to a flash + + align:start position:0% +which will then get compiled to a flash + + + align:start position:0% +which will then get compiled to a flash +app. Or if you want to make a iOS app, + + align:start position:0% +app. Or if you want to make a iOS app, + + + align:start position:0% +app. Or if you want to make a iOS app, +you'll probably compile it to to um the + + align:start position:0% +you'll probably compile it to to um the + + + align:start position:0% +you'll probably compile it to to um the +Xcode C abductive C and then compile + + align:start position:0% +Xcode C abductive C and then compile + + + align:start position:0% +Xcode C abductive C and then compile +that. But basically, it tries to be all + + align:start position:0% +that. But basically, it tries to be all + + + align:start position:0% +that. But basically, it tries to be all +things to all people, which is really + + align:start position:0% +things to all people, which is really + + + align:start position:0% +things to all people, which is really +kind of dangerous. But hopefully for the + + align:start position:0% +kind of dangerous. But hopefully for the + + + align:start position:0% +kind of dangerous. But hopefully for the +kind of smallish projects we're talking + + align:start position:0% +kind of smallish projects we're talking + + + align:start position:0% +kind of smallish projects we're talking +about, that'll be fine. I call this that + + align:start position:0% +about, that'll be fine. I call this that + + + align:start position:0% +about, that'll be fine. I call this that +one a noose because we haven't used it + + align:start position:0% +one a noose because we haven't used it + + + align:start position:0% +one a noose because we haven't used it +much, but it has all the simplicity of + + align:start position:0% +much, but it has all the simplicity of + + + align:start position:0% +much, but it has all the simplicity of +flex for the hacks flex game engine. So, + + align:start position:0% +flex for the hacks flex game engine. So, + + + align:start position:0% +flex for the hacks flex game engine. So, +that is a is a good thing. The other one + + align:start position:0% +that is a is a good thing. The other one + + + align:start position:0% +that is a is a good thing. The other one +we're looking at using this year is + + align:start position:0% +we're looking at using this year is + + + align:start position:0% +we're looking at using this year is +called Phaser, which we know not too + + align:start position:0% +called Phaser, which we know not too + + + align:start position:0% +called Phaser, which we know not too +much about in this lab. The education + + align:start position:0% +much about in this lab. The education + + + align:start position:0% +much about in this lab. The education +arcade is using it and they seem to like + + align:start position:0% +arcade is using it and they seem to like + + + align:start position:0% +arcade is using it and they seem to like +it and it is an action script HTML 5 + + align:start position:0% +it and it is an action script HTML 5 + + + align:start position:0% +it and it is an action script HTML 5 +style of engine. Um that is not the most + + align:start position:0% +style of engine. Um that is not the most + + + align:start position:0% +style of engine. Um that is not the most +mature platform to to build on because + + align:start position:0% +mature platform to to build on because + + + align:start position:0% +mature platform to to build on because +of all the browser differences and stuff + + align:start position:0% +of all the browser differences and stuff + + + align:start position:0% +of all the browser differences and stuff +like that but it is certainly possible. + + align:start position:0% +like that but it is certainly possible. + + + align:start position:0% +like that but it is certainly possible. +I recommend if you end up using phaser + + align:start position:0% +I recommend if you end up using phaser + + + align:start position:0% +I recommend if you end up using phaser +that rather than coding in pure + + align:start position:0% +that rather than coding in pure + + + align:start position:0% +that rather than coding in pure +JavaScript you code in true script which + + align:start position:0% +JavaScript you code in true script which + + + align:start position:0% +JavaScript you code in true script which +is basically a strongly typed version of + + align:start position:0% +is basically a strongly typed version of + + + align:start position:0% +is basically a strongly typed version of +JavaScript. We'll get on to the rest of + + align:start position:0% +JavaScript. We'll get on to the rest of + + + align:start position:0% +JavaScript. We'll get on to the rest of +it. So + + align:start position:0% +it. So + + + align:start position:0% +it. So +Typescript, sorry, TypeScript. Yes, + + align:start position:0% +Typescript, sorry, TypeScript. Yes, + + + align:start position:0% +Typescript, sorry, TypeScript. Yes, +Typescript. + + align:start position:0% +Typescript. + + + align:start position:0% +Typescript. +Um, so when you're learning an engine, + + align:start position:0% +Um, so when you're learning an engine, + + + align:start position:0% +Um, so when you're learning an engine, +you start with tutorials. That's the + + align:start position:0% +you start with tutorials. That's the + + + align:start position:0% +you start with tutorials. That's the +easiest thing to do. Um, once you've + + align:start position:0% +easiest thing to do. Um, once you've + + + align:start position:0% +easiest thing to do. Um, once you've +learned three or four engines, you might + + align:start position:0% +learned three or four engines, you might + + + align:start position:0% +learned three or four engines, you might +not use tutorials, but until then, I + + align:start position:0% +not use tutorials, but until then, I + + + align:start position:0% +not use tutorials, but until then, I +would say you should actually go through + + align:start position:0% +would say you should actually go through + + + align:start position:0% +would say you should actually go through +something that someone's written and + + align:start position:0% +something that someone's written and + + + align:start position:0% +something that someone's written and +thought about how to progress. Um, do + + align:start position:0% +thought about how to progress. Um, do + + + align:start position:0% +thought about how to progress. Um, do +something extremely small. Don't start + + align:start position:0% +something extremely small. Don't start + + + align:start position:0% +something extremely small. Don't start +with the beall and endall game of + + align:start position:0% +with the beall and endall game of + + + align:start position:0% +with the beall and endall game of +awesomeness. Start with something very, + + align:start position:0% +awesomeness. Start with something very, + + + align:start position:0% +awesomeness. Start with something very, +very easy. Um, and then after you've + + align:start position:0% +very easy. Um, and then after you've + + + align:start position:0% +very easy. Um, and then after you've +done that, you're going to discover that + + align:start position:0% +done that, you're going to discover that + + + align:start position:0% +done that, you're going to discover that +you've done some things. Then read the + + align:start position:0% +you've done some things. Then read the + + + align:start position:0% +you've done some things. Then read the +documentation a little bit more because + + align:start position:0% +documentation a little bit more because + + + align:start position:0% +documentation a little bit more because +you're going to be better at picking up + + align:start position:0% +you're going to be better at picking up + + + align:start position:0% +you're going to be better at picking up +stuff after you have questions in your + + align:start position:0% +stuff after you have questions in your + + + align:start position:0% +stuff after you have questions in your +head, even if you don't realize what + + align:start position:0% +head, even if you don't realize what + + + align:start position:0% +head, even if you don't realize what +questions you've + + align:start position:0% +questions you've + + + align:start position:0% +questions you've +got. And we're warming up to an + + align:start position:0% +got. And we're warming up to an + + + align:start position:0% +got. And we're warming up to an +assignment where we're going to hand you + + align:start position:0% +assignment where we're going to hand you + + + align:start position:0% +assignment where we're going to hand you +a game engine and you're going to take a + + align:start position:0% +a game engine and you're going to take a + + + align:start position:0% +a game engine and you're going to take a +look at it over the weekend or over the + + align:start position:0% +look at it over the weekend or over the + + + align:start position:0% +look at it over the weekend or over the +week. But the thing you need to remember + + align:start position:0% +week. But the thing you need to remember + + + align:start position:0% +week. But the thing you need to remember +is that all software really does + + align:start position:0% +is that all software really does + + + align:start position:0% +is that all software really does +suck and game engine are no exception. + + align:start position:0% +suck and game engine are no exception. + + + align:start position:0% +suck and game engine are no exception. +Um, at this point in invariably someone + + align:start position:0% +Um, at this point in invariably someone + + + align:start position:0% +Um, at this point in invariably someone +will claim that Linux doesn't suck. Um, + + align:start position:0% +will claim that Linux doesn't suck. Um, + + + align:start position:0% +will claim that Linux doesn't suck. Um, +to which I'll have to claim that it + + align:start position:0% +to which I'll have to claim that it + + + align:start position:0% +to which I'll have to claim that it +does, but it's also awesome. And that's + + align:start position:0% +does, but it's also awesome. And that's + + + align:start position:0% +does, but it's also awesome. And that's +the thing about software and game + + align:start position:0% +the thing about software and game + + + align:start position:0% +the thing about software and game +engines. Um, you have to really + + align:start position:0% +engines. Um, you have to really + + + align:start position:0% +engines. Um, you have to really +understand and appreciate the ins and + + align:start position:0% +understand and appreciate the ins and + + + align:start position:0% +understand and appreciate the ins and +outs of Linux before we understand the + + align:start position:0% +outs of Linux before we understand the + + + align:start position:0% +outs of Linux before we understand the +ways in which it really does suck, but + + align:start position:0% +ways in which it really does suck, but + + + align:start position:0% +ways in which it really does suck, but +the ways it's really also really + + align:start position:0% +the ways it's really also really + + + align:start position:0% +the ways it's really also really +awesome. Um, operating systems al all + + align:start position:0% +awesome. Um, operating systems al all + + + align:start position:0% +awesome. Um, operating systems al all +really are pretty bad. Um, I suspect, + + align:start position:0% +really are pretty bad. Um, I suspect, + + + align:start position:0% +really are pretty bad. Um, I suspect, +you know, Windows and Mac, you can make + + align:start position:0% +you know, Windows and Mac, you can make + + + align:start position:0% +you know, Windows and Mac, you can make +huge arguments about all of them. + + align:start position:0% +huge arguments about all of them. + + + align:start position:0% +huge arguments about all of them. +Photoshop, we talked about earlier, is a + + align:start position:0% +Photoshop, we talked about earlier, is a + + + align:start position:0% +Photoshop, we talked about earlier, is a +awesomely powerful tool, but to sit down + + align:start position:0% +awesomely powerful tool, but to sit down + + + align:start position:0% +awesomely powerful tool, but to sit down +and actually start using it as a + + align:start position:0% +and actually start using it as a + + + align:start position:0% +and actually start using it as a +beginner, as a newbie, is a miserable + + align:start position:0% +beginner, as a newbie, is a miserable + + + align:start position:0% +beginner, as a newbie, is a miserable +experience. And I think you probably all + + align:start position:0% +experience. And I think you probably all + + + align:start position:0% +experience. And I think you probably all +have very similar experiences with + + align:start position:0% +have very similar experiences with + + + align:start position:0% +have very similar experiences with +software. It's buggy. It's painful. This + + align:start position:0% +software. It's buggy. It's painful. This + + + align:start position:0% +software. It's buggy. It's painful. This +is true for game engines, too. You're + + align:start position:0% +is true for game engines, too. You're + + + align:start position:0% +is true for game engines, too. You're +going to try out a game engine, and + + align:start position:0% +going to try out a game engine, and + + + align:start position:0% +going to try out a game engine, and +you're probably come back to class + + align:start position:0% +you're probably come back to class + + + align:start position:0% +you're probably come back to class +thinking, "I tried Unity. It was + + align:start position:0% +thinking, "I tried Unity. It was + + + align:start position:0% +thinking, "I tried Unity. It was +terrible. I didn't understand what was + + align:start position:0% +terrible. I didn't understand what was + + + align:start position:0% +terrible. I didn't understand what was +going on. It was really hard." And then + + align:start position:0% +going on. It was really hard." And then + + + align:start position:0% +going on. It was really hard." And then +you'll hear someone else talk about + + align:start position:0% +you'll hear someone else talk about + + + align:start position:0% +you'll hear someone else talk about +Flexil, and you'll think, "Wow, I didn't + + align:start position:0% +Flexil, and you'll think, "Wow, I didn't + + + align:start position:0% +Flexil, and you'll think, "Wow, I didn't +have any of those problems." And so this + + align:start position:0% +have any of those problems." And so this + + + align:start position:0% +have any of those problems." And so this +is the trick. All software sucks. And + + align:start position:0% +is the trick. All software sucks. And + + + align:start position:0% +is the trick. All software sucks. And +your job is to find the software that + + align:start position:0% +your job is to find the software that + + + align:start position:0% +your job is to find the software that +sucks in ways that you can + + align:start position:0% +sucks in ways that you can + + + align:start position:0% +sucks in ways that you can +handle, right? That you don't mind so + + align:start position:0% +handle, right? That you don't mind so + + + align:start position:0% +handle, right? That you don't mind so +much that you have to think in 3D for + + align:start position:0% +much that you have to think in 3D for + + + align:start position:0% +much that you have to think in 3D for +Unity because you're willing to put up + + align:start position:0% +Unity because you're willing to put up + + + align:start position:0% +Unity because you're willing to put up +with that because you get these cool + + align:start position:0% +with that because you get these cool + + + align:start position:0% +with that because you get these cool +nice rendered look. Or maybe you deal + + align:start position:0% +nice rendered look. Or maybe you deal + + + align:start position:0% +nice rendered look. Or maybe you deal +with the fact that yeah, Flixel's + + align:start position:0% +with the fact that yeah, Flixel's + + + align:start position:0% +with the fact that yeah, Flixel's +written written in action script three + + align:start position:0% +written written in action script three + + + align:start position:0% +written written in action script three +and uh I hate that language, but boy, it + + align:start position:0% +and uh I hate that language, but boy, it + + + align:start position:0% +and uh I hate that language, but boy, it +sure is easy to put stuff up on the + + align:start position:0% +sure is easy to put stuff up on the + + + align:start position:0% +sure is easy to put stuff up on the +screen, have spaceships move around + + align:start position:0% +screen, have spaceships move around + + + align:start position:0% +screen, have spaceships move around +shooting each other in like a day with + + align:start position:0% +shooting each other in like a day with + + + align:start position:0% +shooting each other in like a day with +no problem. And these are the kinds of + + align:start position:0% +no problem. And these are the kinds of + + + align:start position:0% +no problem. And these are the kinds of +trade-offs you're going have to look at. + + align:start position:0% +trade-offs you're going have to look at. + + + align:start position:0% +trade-offs you're going have to look at. +So when you're trying to evaluate a game + + align:start position:0% +So when you're trying to evaluate a game + + + align:start position:0% +So when you're trying to evaluate a game +engine or any piece of software really, + + align:start position:0% +engine or any piece of software really, + + + align:start position:0% +engine or any piece of software really, +but game engines for this class, you're + + align:start position:0% +but game engines for this class, you're + + + align:start position:0% +but game engines for this class, you're +going to think about the ways in which + + align:start position:0% +going to think about the ways in which + + + align:start position:0% +going to think about the ways in which +it's terrible, but also think about the + + align:start position:0% +it's terrible, but also think about the + + + align:start position:0% +it's terrible, but also think about the +ways in which it's great. And when you + + align:start position:0% +ways in which it's great. And when you + + + align:start position:0% +ways in which it's great. And when you +get together and talked with a team for + + align:start position:0% +get together and talked with a team for + + + align:start position:0% +get together and talked with a team for +projects two through four about what + + align:start position:0% +projects two through four about what + + + align:start position:0% +projects two through four about what +game engine to use, you're going to want + + align:start position:0% +game engine to use, you're going to want + + + align:start position:0% +game engine to use, you're going to want +to be able to say intelligently, I don't + + align:start position:0% +to be able to say intelligently, I don't + + + align:start position:0% +to be able to say intelligently, I don't +like flex because of these things, but + + align:start position:0% +like flex because of these things, but + + + align:start position:0% +like flex because of these things, but +actually I can live with those things. + + align:start position:0% +actually I can live with those things. + + + align:start position:0% +actually I can live with those things. +Or I don't like Unity because of this + + align:start position:0% +Or I don't like Unity because of this + + + align:start position:0% +Or I don't like Unity because of this +thing and I really just can't get past + + align:start position:0% +thing and I really just can't get past + + + align:start position:0% +thing and I really just can't get past +it. And if your team's insisting on + + align:start position:0% +it. And if your team's insisting on + + + align:start position:0% +it. And if your team's insisting on +using that engine and you really know + + align:start position:0% +using that engine and you really know + + + align:start position:0% +using that engine and you really know +you really don't like it, consider + + align:start position:0% +you really don't like it, consider + + + align:start position:0% +you really don't like it, consider +another team. And that's not bad. + + align:start position:0% +another team. And that's not bad. + + + align:start position:0% +another team. And that's not bad. +Different people are going to have + + align:start position:0% +Different people are going to have + + + align:start position:0% +Different people are going to have +different preferences for different + + align:start position:0% +different preferences for different + + + align:start position:0% +different preferences for different +styles. And that's part of what we're + + align:start position:0% +styles. And that's part of what we're + + + align:start position:0% +styles. And that's part of what we're +going to be doing. Anytime you're + + align:start position:0% +going to be doing. Anytime you're + + + align:start position:0% +going to be doing. Anytime you're +forming a team or trying to work with a + + align:start position:0% +forming a team or trying to work with a + + + align:start position:0% +forming a team or trying to work with a +team, you're going have to figure out + + align:start position:0% +team, you're going have to figure out + + + align:start position:0% +team, you're going have to figure out +what works for you, what's hard for you, + + align:start position:0% +what works for you, what's hard for you, + + + align:start position:0% +what works for you, what's hard for you, +what's easy for you, and try to match + + align:start position:0% +what's easy for you, and try to match + + + align:start position:0% +what's easy for you, and try to match +yourself up with tasks or software that + + align:start position:0% +yourself up with tasks or software that + + + align:start position:0% +yourself up with tasks or software that +matches your set of skills. Or if you + + align:start position:0% +matches your set of skills. Or if you + + + align:start position:0% +matches your set of skills. Or if you +want to challenge yourself, okay, be + + align:start position:0% +want to challenge yourself, okay, be + + + align:start position:0% +want to challenge yourself, okay, be +ready to challenge yourself and try + + align:start position:0% +ready to challenge yourself and try + + + align:start position:0% +ready to challenge yourself and try +something that you thought was too hard + + align:start position:0% +something that you thought was too hard + + + align:start position:0% +something that you thought was too hard +or too painful, but be aware that you're + + align:start position:0% +or too painful, but be aware that you're + + + align:start position:0% +or too painful, but be aware that you're +doing that because you need to let your + + align:start position:0% +doing that because you need to let your + + + align:start position:0% +doing that because you need to let your +team know, hey, I'm going to be on a + + align:start position:0% +team know, hey, I'm going to be on a + + + align:start position:0% +team know, hey, I'm going to be on a +learning curve here. You're going to + + align:start position:0% +learning curve here. You're going to + + + align:start position:0% +learning curve here. You're going to +have to help me out. + + align:start position:0% +have to help me out. + + + align:start position:0% +have to help me out. +So, as you look at a game engine, be + + align:start position:0% +So, as you look at a game engine, be + + + align:start position:0% +So, as you look at a game engine, be +aware that it is going to disappoint + + align:start position:0% +aware that it is going to disappoint + + + align:start position:0% +aware that it is going to disappoint +you. That's just the way it is. But try + + align:start position:0% +you. That's just the way it is. But try + + + align:start position:0% +you. That's just the way it is. But try +to figure out where those + + align:start position:0% +to figure out where those + + + align:start position:0% +to figure out where those +disappointments + + align:start position:0% +disappointments + + + align:start position:0% +disappointments +are. To that end, we one of our + + align:start position:0% +are. To that end, we one of our + + + align:start position:0% +are. To that end, we one of our +assignments. + + align:start position:0% +assignments. + + + align:start position:0% +assignments. +Yes. + + align:start position:0% +Yes. + + + align:start position:0% +Yes. +Which 2D game engine would you suggest + + align:start position:0% +Which 2D game engine would you suggest + + + align:start position:0% +Which 2D game engine would you suggest +for those who are comfortable with Java + + align:start position:0% +for those who are comfortable with Java + + + align:start position:0% +for those who are comfortable with Java +and C#? With Java and C, it kind of + + align:start position:0% +and C#? With Java and C, it kind of + + + align:start position:0% +and C#? With Java and C, it kind of +depends on the situation. + + align:start position:0% +depends on the situation. + + + align:start position:0% +depends on the situation. +Um, I would actually still suggest for + + align:start position:0% +Um, I would actually still suggest for + + + align:start position:0% +Um, I would actually still suggest for +most simple very which game engine + + align:start position:0% +most simple very which game engine + + + align:start position:0% +most simple very which game engine +should I use for 2D? And the answer is + + align:start position:0% +should I use for 2D? And the answer is + + + align:start position:0% +should I use for 2D? And the answer is +if you have no 3D experience whatsoever, + + align:start position:0% +if you have no 3D experience whatsoever, + + + align:start position:0% +if you have no 3D experience whatsoever, +I would still recommend Hix Flickle. Um, + + align:start position:0% +I would still recommend Hix Flickle. Um, + + + align:start position:0% +I would still recommend Hix Flickle. Um, +today um, if you are comfortable with 3D + + align:start position:0% +today um, if you are comfortable with 3D + + + align:start position:0% +today um, if you are comfortable with 3D +and some of the barriers there, I would + + align:start position:0% +and some of the barriers there, I would + + + align:start position:0% +and some of the barriers there, I would +I would go with Unity. I personally use + + align:start position:0% +I would go with Unity. I personally use + + + align:start position:0% +I would go with Unity. I personally use +Unity for my own development. Um, that + + align:start position:0% +Unity for my own development. Um, that + + + align:start position:0% +Unity for my own development. Um, that +said, what we're going to do is + + align:start position:0% +said, what we're going to do is + + + align:start position:0% +said, what we're going to do is +everybody's going to take a look at a + + align:start position:0% +everybody's going to take a look at a + + + align:start position:0% +everybody's going to take a look at a +game engine. So, you'll have at least + + align:start position:0% +game engine. So, you'll have at least + + + align:start position:0% +game engine. So, you'll have at least +one of the four that that we're talking + + align:start position:0% +one of the four that that we're talking + + + align:start position:0% +one of the four that that we're talking +about for the class you you're familiar + + align:start position:0% +about for the class you you're familiar + + + align:start position:0% +about for the class you you're familiar +with. And hopefully in the next couple + + align:start position:0% +with. And hopefully in the next couple + + + align:start position:0% +with. And hopefully in the next couple +of weeks, you'll you'll get your own + + align:start position:0% +of weeks, you'll you'll get your own + + + align:start position:0% +of weeks, you'll you'll get your own +preference. Um, because I can easily + + align:start position:0% +preference. Um, because I can easily + + + align:start position:0% +preference. Um, because I can easily +say, sure, Flexil is great for 2D games, + + align:start position:0% +say, sure, Flexil is great for 2D games, + + + align:start position:0% +say, sure, Flexil is great for 2D games, +and it is for the right kind of 2D + + align:start position:0% +and it is for the right kind of 2D + + + align:start position:0% +and it is for the right kind of 2D +games. It's not good for all the 2D + + align:start position:0% +games. It's not good for all the 2D + + + align:start position:0% +games. It's not good for all the 2D +games. An isometric thing with lots of + + align:start position:0% +games. An isometric thing with lots of + + + align:start position:0% +games. An isometric thing with lots of +farms and stuff, you might be able to do + + align:start position:0% +farms and stuff, you might be able to do + + + align:start position:0% +farms and stuff, you might be able to do +it, but you might be more comfortable + + align:start position:0% +it, but you might be more comfortable + + + align:start position:0% +it, but you might be more comfortable +using a 3D approach or whatever. So, in + + align:start position:0% +using a 3D approach or whatever. So, in + + + align:start position:0% +using a 3D approach or whatever. So, in +other words, it really depends on the + + align:start position:0% +other words, it really depends on the + + + align:start position:0% +other words, it really depends on the +game, too. I wish I could give you an + + align:start position:0% +game, too. I wish I could give you an + + + align:start position:0% +game, too. I wish I could give you an +easy answer, but I can't, which is why + + align:start position:0% +easy answer, but I can't, which is why + + + align:start position:0% +easy answer, but I can't, which is why +the whole + + align:start position:0% +the whole + + + align:start position:0% +the whole +lecture. So, we have an assignment which + + align:start position:0% +lecture. So, we have an assignment which + + + align:start position:0% +lecture. So, we have an assignment which +we'll hand out to you now. + + align:start position:0% + + + + align:start position:0% + +Um, and we're going to talk about it one + + align:start position:0% +Um, and we're going to talk about it one + + + align:start position:0% +Um, and we're going to talk about it one +week from + + align:start position:0% +week from + + + align:start position:0% +week from +now. And do stay tuned because we're not + + align:start position:0% +now. And do stay tuned because we're not + + + align:start position:0% +now. And do stay tuned because we're not +done talking at you or giving you + + align:start position:0% +done talking at you or giving you + + + align:start position:0% +done talking at you or giving you +assignments. + + align:start position:0% + + + + align:start position:0% + +Yep. With the game engine tutorial. Yes. + + align:start position:0% +Yep. With the game engine tutorial. Yes. + + + align:start position:0% +Yep. With the game engine tutorial. Yes. +What I want you to do is + + align:start position:0% +What I want you to do is + + + align:start position:0% +What I want you to do is +pick a game engine out of this hat and + + align:start position:0% +pick a game engine out of this hat and + + + align:start position:0% +pick a game engine out of this hat and +pass it on. + + align:start position:0% +pass it on. + + + align:start position:0% +pass it on. +If you do not like the game engine that + + align:start position:0% +If you do not like the game engine that + + + align:start position:0% +If you do not like the game engine that +you get, trade. + + align:start position:0% + + + + align:start position:0% + +Uh, sure, feel free. + + align:start position:0% +Uh, sure, feel free. + + + align:start position:0% +Uh, sure, feel free. +Take a + + align:start position:0% +Take a + + + align:start position:0% +Take a +handful. If I run out, I have more + + align:start position:0% +handful. If I run out, I have more + + + align:start position:0% +handful. If I run out, I have more +tokens. But this is why this is why I + + align:start position:0% +tokens. But this is why this is why I + + + align:start position:0% +tokens. But this is why this is why I +start with make sure there's a good + + align:start position:0% +start with make sure there's a good + + + align:start position:0% +start with make sure there's a good +distribution. Let's go ahead and hand + + align:start position:0% +distribution. Let's go ahead and hand + + + align:start position:0% +distribution. Let's go ahead and hand +this back. I don't need to be with + + align:start position:0% + + + + align:start position:0% + +it. So, one of the things we're going to + + align:start position:0% +it. So, one of the things we're going to + + + align:start position:0% +it. So, one of the things we're going to +do next + + align:start position:0% +do next + + + align:start position:0% +do next +Wednesday is try to do a source control + + align:start position:0% +Wednesday is try to do a source control + + + align:start position:0% +Wednesday is try to do a source control +exercise, which will introduce some of + + align:start position:0% +exercise, which will introduce some of + + + align:start position:0% +exercise, which will introduce some of +you to source control and hopefully + + align:start position:0% +you to source control and hopefully + + + align:start position:0% +you to source control and hopefully +refresh some of you. + + align:start position:0% +refresh some of you. + + + align:start position:0% +refresh some of you. +So ideally, if you can, we want you to + + align:start position:0% +So ideally, if you can, we want you to + + + align:start position:0% +So ideally, if you can, we want you to +bring in a development machine, a laptop + + align:start position:0% +bring in a development machine, a laptop + + + align:start position:0% +bring in a development machine, a laptop +if that's what you're using on um that + + align:start position:0% +if that's what you're using on um that + + + align:start position:0% +if that's what you're using on um that +Wednesday. If you only have a desktop, + + align:start position:0% +Wednesday. If you only have a desktop, + + + align:start position:0% +Wednesday. If you only have a desktop, +don't. If you've got no computer, don't. + + align:start position:0% +don't. If you've got no computer, don't. + + + align:start position:0% +don't. If you've got no computer, don't. +But, you know, try to bring in a + + align:start position:0% +But, you know, try to bring in a + + + align:start position:0% +But, you know, try to bring in a +development machine of some kind that + + align:start position:0% +development machine of some kind that + + + align:start position:0% +development machine of some kind that +you can actually use on Wednesday. + + align:start position:0% +you can actually use on Wednesday. + + + align:start position:0% +you can actually use on Wednesday. +Ideally, the machine you use to do the + + align:start position:0% +Ideally, the machine you use to do the + + + align:start position:0% +Ideally, the machine you use to do the +tutorials. Um, so you have your code on + + align:start position:0% +tutorials. Um, so you have your code on + + + align:start position:0% +tutorials. Um, so you have your code on +it. Um, let's see, what else do we want + + align:start position:0% +it. Um, let's see, what else do we want + + + align:start position:0% +it. Um, let's see, what else do we want +to say? There is um we don't want you to + + align:start position:0% +to say? There is um we don't want you to + + + align:start position:0% +to say? There is um we don't want you to +spend more than four hours on this + + align:start position:0% +spend more than four hours on this + + + align:start position:0% +spend more than four hours on this +exercise. There is no turnin for this + + align:start position:0% +exercise. There is no turnin for this + + + align:start position:0% +exercise. There is no turnin for this +exercise. What we want is for on + + align:start position:0% +exercise. What we want is for on + + + align:start position:0% +exercise. What we want is for on +Wednesday we're going to be able to talk + + align:start position:0% +Wednesday we're going to be able to talk + + + align:start position:0% +Wednesday we're going to be able to talk +about the game engine that you looked + + align:start position:0% +about the game engine that you looked + + + align:start position:0% +about the game engine that you looked +at. You want to talk about its pluses + + align:start position:0% +at. You want to talk about its pluses + + + align:start position:0% +at. You want to talk about its pluses +and its minuses. What was frustrating. + + align:start position:0% +and its minuses. What was frustrating. + + + align:start position:0% +and its minuses. What was frustrating. +If it took you all four hours just to + + align:start position:0% +If it took you all four hours just to + + + align:start position:0% +If it took you all four hours just to +install the stupid thing in the first + + align:start position:0% +install the stupid thing in the first + + + align:start position:0% +install the stupid thing in the first +place, that's information. We want to + + align:start position:0% +place, that's information. We want to + + + align:start position:0% +place, that's information. We want to +know that because that will help people + + align:start position:0% +know that because that will help people + + + align:start position:0% +know that because that will help people +choose to not use that game engine. Um + + align:start position:0% +choose to not use that game engine. Um + + + align:start position:0% +choose to not use that game engine. Um +for example. Um, + + align:start position:0% +for example. Um, + + + align:start position:0% +for example. Um, +but basically we want to be able to talk + + align:start position:0% +but basically we want to be able to talk + + + align:start position:0% +but basically we want to be able to talk +intelligently in groups amongst + + align:start position:0% +intelligently in groups amongst + + + align:start position:0% +intelligently in groups amongst +yourselves about the game engine pros + + align:start position:0% +yourselves about the game engine pros + + + align:start position:0% +yourselves about the game engine pros +and cons. That's the main goal. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Any questions or comments so far? + + align:start position:0% +Any questions or comments so far? + + + align:start position:0% +Any questions or comments so far? +You can't just pick any one of those. + + align:start position:0% +You can't just pick any one of those. + + + align:start position:0% +You can't just pick any one of those. +Pardon? So, you can only trade ones you + + align:start position:0% +Pardon? So, you can only trade ones you + + + align:start position:0% +Pardon? So, you can only trade ones you +have for others, right? Correct. Do not + + align:start position:0% +have for others, right? Correct. Do not + + + align:start position:0% +have for others, right? Correct. Do not +pick a game engine at random. you may + + align:start position:0% +pick a game engine at random. you may + + + align:start position:0% +pick a game engine at random. you may +trade the one you've got in your hand + + align:start position:0% +trade the one you've got in your hand + + + align:start position:0% +trade the one you've got in your hand +with someone else who has a different + + align:start position:0% +with someone else who has a different + + + align:start position:0% +with someone else who has a different +one in their hand. This is not just it + + align:start position:0% +one in their hand. This is not just it + + + align:start position:0% +one in their hand. This is not just it +is it's partially arbitrary but mostly + + align:start position:0% +is it's partially arbitrary but mostly + + + align:start position:0% +is it's partially arbitrary but mostly +it's to make sure that all the engines + + align:start position:0% +it's to make sure that all the engines + + + align:start position:0% +it's to make sure that all the engines +are covered about equally. Um also + + align:start position:0% +are covered about equally. Um also + + + align:start position:0% +are covered about equally. Um also +there's two entries for Unity. One is + + align:start position:0% +there's two entries for Unity. One is + + + align:start position:0% +there's two entries for Unity. One is +sort of think about it 3D and one is + + align:start position:0% +sort of think about it 3D and one is + + + align:start position:0% +sort of think about it 3D and one is +think about it 2D. Um and because the + + align:start position:0% +think about it 2D. Um and because the + + + align:start position:0% +think about it 2D. Um and because the +Unity has recently added a sort of a 2D + + align:start position:0% +Unity has recently added a sort of a 2D + + + align:start position:0% +Unity has recently added a sort of a 2D +layer on top of it that you can sort of + + align:start position:0% +layer on top of it that you can sort of + + + align:start position:0% +layer on top of it that you can sort of +use it as a sprite based engine. Um, so + + align:start position:0% +use it as a sprite based engine. Um, so + + + align:start position:0% +use it as a sprite based engine. Um, so +we want you to sort of put that through + + align:start position:0% +we want you to sort of put that through + + + align:start position:0% +we want you to sort of put that through +its paces, too, because to compare it to + + align:start position:0% +its paces, too, because to compare it to + + + align:start position:0% +its paces, too, because to compare it to +other the other 2D engines to Java. So, + + align:start position:0% +other the other 2D engines to Java. So, + + + align:start position:0% +other the other 2D engines to Java. So, +um, I've never had much of a problem + + align:start position:0% +um, I've never had much of a problem + + + align:start position:0% +um, I've never had much of a problem +transitioning between the two. + + align:start position:0% +transitioning between the two. + + + align:start position:0% +transitioning between the two. +Some that don't. Okay. Um, uh, let's + + align:start position:0% +Some that don't. Okay. Um, uh, let's + + + align:start position:0% +Some that don't. Okay. Um, uh, let's +see. No. Yeah, I would trade if you + + align:start position:0% +see. No. Yeah, I would trade if you + + + align:start position:0% +see. No. Yeah, I would trade if you +could. + + align:start position:0% +could. + + + align:start position:0% +could. +So, um, like we said, this is a video + + align:start position:0% +So, um, like we said, this is a video + + + align:start position:0% +So, um, like we said, this is a video +game development or video game + + align:start position:0% +game development or video game + + + align:start position:0% +game development or video game +production class. about team management, + + align:start position:0% +production class. about team management, + + + align:start position:0% +production class. about team management, +project management. We're spending a lot + + align:start position:0% +project management. We're spending a lot + + + align:start position:0% +project management. We're spending a lot +of time on those kind of topics. We + + align:start position:0% +of time on those kind of topics. We + + + align:start position:0% +of time on those kind of topics. We +aren't spending a ton of time talking + + align:start position:0% +aren't spending a ton of time talking + + + align:start position:0% +aren't spending a ton of time talking +about design in + + align:start position:0% +about design in + + + align:start position:0% +about design in +class, but we were jerks and we're + + align:start position:0% +class, but we were jerks and we're + + + align:start position:0% +class, but we were jerks and we're +giving you a really really hard design + + align:start position:0% +giving you a really really hard design + + + align:start position:0% +giving you a really really hard design +constraint to work with for for project + + align:start position:0% +constraint to work with for for project + + + align:start position:0% +constraint to work with for for project +4. So, um we're going to have some + + align:start position:0% +4. So, um we're going to have some + + + align:start position:0% +4. So, um we're going to have some +optional assignments, optional reading, + + align:start position:0% +optional assignments, optional reading, + + + align:start position:0% +optional assignments, optional reading, +um basically things that we're going to + + align:start position:0% +um basically things that we're going to + + + align:start position:0% +um basically things that we're going to +list on stellar and a couple lectures + + align:start position:0% +list on stellar and a couple lectures + + + align:start position:0% +list on stellar and a couple lectures +we're going to give. Um basically just + + align:start position:0% +we're going to give. Um basically just + + + align:start position:0% +we're going to give. Um basically just +kind of opening your minds towards + + align:start position:0% +kind of opening your minds towards + + + align:start position:0% +kind of opening your minds towards +design. um so you can think through some + + align:start position:0% +design. um so you can think through some + + + align:start position:0% +design. um so you can think through some +of the big hairy problems when it comes + + align:start position:0% +of the big hairy problems when it comes + + + align:start position:0% +of the big hairy problems when it comes +to designing some of these things. Uh + + align:start position:0% +to designing some of these things. Uh + + + align:start position:0% +to designing some of these things. Uh +the first thing is talking about the + + align:start position:0% +the first thing is talking about the + + + align:start position:0% +the first thing is talking about the +theme for the for the course for the + + align:start position:0% +theme for the for the course for the + + + align:start position:0% +theme for the for the course for the +semester. So we're talking about + + align:start position:0% +semester. So we're talking about + + + align:start position:0% +semester. So we're talking about +meaningful decisions in + + align:start position:0% +meaningful decisions in + + + align:start position:0% +meaningful decisions in +games. Um so we're asking you when + + align:start position:0% +games. Um so we're asking you when + + + align:start position:0% +games. Um so we're asking you when +you're creating these four projects to + + align:start position:0% +you're creating these four projects to + + + align:start position:0% +you're creating these four projects to +think about what decisions your your + + align:start position:0% +think about what decisions your your + + + align:start position:0% +think about what decisions your your +players are making during the game at + + align:start position:0% +players are making during the game at + + + align:start position:0% +players are making during the game at +all times. Um and to make sure that all + + align:start position:0% +all times. Um and to make sure that all + + + align:start position:0% +all times. Um and to make sure that all +those those decisions they make are + + align:start position:0% +those those decisions they make are + + + align:start position:0% +those those decisions they make are +meaningful. And this is going to be the + + align:start position:0% +meaningful. And this is going to be the + + + align:start position:0% +meaningful. And this is going to be the +foundation for the four for the the four + + align:start position:0% +foundation for the four for the the four + + + align:start position:0% +foundation for the four for the the four +projects that you're working on. All the + + align:start position:0% +projects that you're working on. All the + + + align:start position:0% +projects that you're working on. All the +constraints are going to be based on + + align:start position:0% +constraints are going to be based on + + + align:start position:0% +constraints are going to be based on +this kind of + + align:start position:0% +this kind of + + + align:start position:0% +this kind of +thing. So first off, what do we mean by + + align:start position:0% +thing. So first off, what do we mean by + + + align:start position:0% +thing. So first off, what do we mean by +meaningful decisions? This is what I + + align:start position:0% +meaningful decisions? This is what I + + + align:start position:0% +meaningful decisions? This is what I +mean when I say it. There's other + + align:start position:0% +mean when I say it. There's other + + + align:start position:0% +mean when I say it. There's other +definitions out there, but this is like + + align:start position:0% +definitions out there, but this is like + + + align:start position:0% +definitions out there, but this is like +the bare minimum. It should do this. It + + align:start position:0% +the bare minimum. It should do this. It + + + align:start position:0% +the bare minimum. It should do this. It +should have this. So three + + align:start position:0% +should have this. So three + + + align:start position:0% +should have this. So three +things. Um, any decision a player makes + + align:start position:0% +things. Um, any decision a player makes + + + align:start position:0% +things. Um, any decision a player makes +in a game has an effect on the game's + + align:start position:0% +in a game has an effect on the game's + + + align:start position:0% +in a game has an effect on the game's +overall state. So I make a decision, + + align:start position:0% +overall state. So I make a decision, + + + align:start position:0% +overall state. So I make a decision, +something + + align:start position:0% +something + + + align:start position:0% +something +changed. Not only does something change, + + align:start position:0% +changed. Not only does something change, + + + align:start position:0% +changed. Not only does something change, +but that change ripples through the + + align:start position:0% +but that change ripples through the + + + align:start position:0% +but that change ripples through the +systems within the game. It's affect it + + align:start position:0% +systems within the game. It's affect it + + + align:start position:0% +systems within the game. It's affect it +affects the entire game state, the + + align:start position:0% +affects the entire game state, the + + + align:start position:0% +affects the entire game state, the +entire game world, not just what my + + align:start position:0% +entire game world, not just what my + + + align:start position:0% +entire game world, not just what my +player might what the player might have, + + align:start position:0% +player might what the player might have, + + + align:start position:0% +player might what the player might have, +not just the player's performance, not + + align:start position:0% +not just the player's performance, not + + + align:start position:0% +not just the player's performance, not +just the player's ability. So, a jump in + + align:start position:0% +just the player's ability. So, a jump in + + + align:start position:0% +just the player's ability. So, a jump in +these games can be meaningful in some + + align:start position:0% +these games can be meaningful in some + + + align:start position:0% +these games can be meaningful in some +games, but for this particular game, in + + align:start position:0% +games, but for this particular game, in + + + align:start position:0% +games, but for this particular game, in +this particular + + align:start position:0% +this particular + + + align:start position:0% +this particular +use, if the jump affects everything else + + align:start position:0% +use, if the jump affects everything else + + + align:start position:0% +use, if the jump affects everything else +in the game in some form, that was + + align:start position:0% +in the game in some form, that was + + + align:start position:0% +in the game in some form, that was +really meaningful, and I'd be surprised + + align:start position:0% +really meaningful, and I'd be surprised + + + align:start position:0% +really meaningful, and I'd be surprised +to see a jump do that, but it probably + + align:start position:0% +to see a jump do that, but it probably + + + align:start position:0% +to see a jump do that, but it probably +isn't. It's probably just a way to to to + + align:start position:0% +isn't. It's probably just a way to to to + + + align:start position:0% +isn't. It's probably just a way to to to +get over an obstacle. So, there's + + align:start position:0% +get over an obstacle. So, there's + + + align:start position:0% +get over an obstacle. So, there's +something else. There's some other kind + + align:start position:0% +something else. There's some other kind + + + align:start position:0% +something else. There's some other kind +of decision a player has to make rather + + align:start position:0% +of decision a player has to make rather + + + align:start position:0% +of decision a player has to make rather +than just that that that one small + + align:start position:0% +than just that that that one small + + + align:start position:0% +than just that that that one small +decision. + + align:start position:0% +decision. + + + align:start position:0% +decision. +Third, there should be sufficient + + align:start position:0% +Third, there should be sufficient + + + align:start position:0% +Third, there should be sufficient +feedback. And we'll talk about feedback + + align:start position:0% +feedback. And we'll talk about feedback + + + align:start position:0% +feedback. And we'll talk about feedback +later on, what exactly we mean by that. + + align:start position:0% +later on, what exactly we mean by that. + + + align:start position:0% +later on, what exactly we mean by that. +Um, that lets the player be aware that + + align:start position:0% +Um, that lets the player be aware that + + + align:start position:0% +Um, that lets the player be aware that +they made that decision. So, not only + + align:start position:0% +they made that decision. So, not only + + + align:start position:0% +they made that decision. So, not only +did I make a decision, but I knew that I + + align:start position:0% +did I make a decision, but I knew that I + + + align:start position:0% +did I make a decision, but I knew that I +made a decision. There was something + + align:start position:0% +made a decision. There was something + + + align:start position:0% +made a decision. There was something +that happened in the game that prompted + + align:start position:0% +that happened in the game that prompted + + + align:start position:0% +that happened in the game that prompted +me to make that decision, and I actively + + align:start position:0% +me to make that decision, and I actively + + + align:start position:0% +me to make that decision, and I actively +made the decision. I made the choice to + + align:start position:0% +made the decision. I made the choice to + + + align:start position:0% +made the decision. I made the choice to +make the decision. I know I made the + + align:start position:0% +make the decision. I know I made the + + + align:start position:0% +make the decision. I know I made the +decision, and I actually see all those + + align:start position:0% +decision, and I actually see all those + + + align:start position:0% +decision, and I actually see all those +effects happen in some form. Um, at the + + align:start position:0% +effects happen in some form. Um, at the + + + align:start position:0% +effects happen in some form. Um, at the +bare minimum, I make a decision. I see + + align:start position:0% +bare minimum, I make a decision. I see + + + align:start position:0% +bare minimum, I make a decision. I see +some short-term effects. There might be + + align:start position:0% +some short-term effects. There might be + + + align:start position:0% +some short-term effects. There might be +long-term effects that I don't see right + + align:start position:0% +long-term effects that I don't see right + + + align:start position:0% +long-term effects that I don't see right +now, but I will have the opportunity to + + align:start position:0% +now, but I will have the opportunity to + + + align:start position:0% +now, but I will have the opportunity to +see later that's a little bit more + + align:start position:0% +see later that's a little bit more + + + align:start position:0% +see later that's a little bit more +advanced. Um, so we're going to talk + + align:start position:0% +advanced. Um, so we're going to talk + + + align:start position:0% +advanced. Um, so we're going to talk +about, so basically this lecture is + + align:start position:0% +about, so basically this lecture is + + + align:start position:0% +about, so basically this lecture is +really just going to be talking about + + align:start position:0% +really just going to be talking about + + + align:start position:0% +really just going to be talking about +some example games that when we're + + align:start position:0% +some example games that when we're + + + align:start position:0% +some example games that when we're +talking about the games we're um we + + align:start position:0% +talking about the games we're um we + + + align:start position:0% +talking about the games we're um we +would like you to make in class, these + + align:start position:0% +would like you to make in class, these + + + align:start position:0% +would like you to make in class, these +are kind of the exemplar games for for + + align:start position:0% +are kind of the exemplar games for for + + + align:start position:0% +are kind of the exemplar games for for +this. These are the games that we think + + align:start position:0% +this. These are the games that we think + + + align:start position:0% +this. These are the games that we think +of when we think of this kind of thing. + + align:start position:0% +of when we think of this kind of thing. + + + align:start position:0% +of when we think of this kind of thing. +And the problem that I think is going to + + align:start position:0% +And the problem that I think is going to + + + align:start position:0% +And the problem that I think is going to +come up is we're going to sometimes call + + align:start position:0% +come up is we're going to sometimes call + + + align:start position:0% +come up is we're going to sometimes call +them strategy games, which is a really + + align:start position:0% +them strategy games, which is a really + + + align:start position:0% +them strategy games, which is a really +loaded term. Um, what is like what is a + + align:start position:0% +loaded term. Um, what is like what is a + + + align:start position:0% +loaded term. Um, what is like what is a +strategy game? Does anybody have a + + align:start position:0% +strategy game? Does anybody have a + + + align:start position:0% +strategy game? Does anybody have a +definition for what a strategy game is? + + align:start position:0% + + + + align:start position:0% + +Somebody who took Yeah. that involves a + + align:start position:0% +Somebody who took Yeah. that involves a + + + align:start position:0% +Somebody who took Yeah. that involves a +lot of user thinking. Yeah. A game + + align:start position:0% +lot of user thinking. Yeah. A game + + + align:start position:0% +lot of user thinking. Yeah. A game +that's going to require a lot of + + align:start position:0% +that's going to require a lot of + + + align:start position:0% +that's going to require a lot of +thinking. um a game that's going to + + align:start position:0% +thinking. um a game that's going to + + + align:start position:0% +thinking. um a game that's going to +require and by thinking there's a lot of + + align:start position:0% +require and by thinking there's a lot of + + + align:start position:0% +require and by thinking there's a lot of +actions that happen when we talk about + + align:start position:0% +actions that happen when we talk about + + + align:start position:0% +actions that happen when we talk about +player thinking like all right so I'm + + align:start position:0% +player thinking like all right so I'm + + + align:start position:0% +player thinking like all right so I'm +thinking so if I'm thinking I might not + + align:start position:0% +thinking so if I'm thinking I might not + + + align:start position:0% +thinking so if I'm thinking I might not +be taking action so I might be thinking + + align:start position:0% +be taking action so I might be thinking + + + align:start position:0% +be taking action so I might be thinking +to take an action I might be planning is + + align:start position:0% +to take an action I might be planning is + + + align:start position:0% +to take an action I might be planning is +going to be part of it um I might be + + align:start position:0% +going to be part of it um I might be + + + align:start position:0% +going to be part of it um I might be +thinking but there's something that's + + align:start position:0% +thinking but there's something that's + + + align:start position:0% +thinking but there's something that's +distracting me for thinking uh maybe I + + align:start position:0% +distracting me for thinking uh maybe I + + + align:start position:0% +distracting me for thinking uh maybe I +have to make actions really really fast + + align:start position:0% +have to make actions really really fast + + + align:start position:0% +have to make actions really really fast +or I can make actions and I can think a + + align:start position:0% +or I can make actions and I can think a + + + align:start position:0% +or I can make actions and I can think a +long period of time all of that that's a + + align:start position:0% +long period of time all of that that's a + + + align:start position:0% +long period of time all of that that's a +wigwide spectrum what we're talking + + align:start position:0% +wigwide spectrum what we're talking + + + align:start position:0% +wigwide spectrum what we're talking +about with strategy games um can anybody + + align:start position:0% +about with strategy games um can anybody + + + align:start position:0% +about with strategy games um can anybody +list some strategy games they've played + + align:start position:0% +list some strategy games they've played + + + align:start position:0% +list some strategy games they've played +or have heard about Age of Empires. Age + + align:start position:0% +or have heard about Age of Empires. Age + + + align:start position:0% +or have heard about Age of Empires. Age +of Empires. Which one? Second one. Yes, + + align:start position:0% +of Empires. Which one? Second one. Yes, + + + align:start position:0% +of Empires. Which one? Second one. Yes, +it is. + + align:start position:0% +it is. + + + align:start position:0% +it is. +Civilization. Yes. Which one? Five. + + align:start position:0% +Civilization. Yes. Which one? Five. + + + align:start position:0% +Civilization. Yes. Which one? Five. +Okay. I like that one, + + align:start position:0% +Okay. I like that one, + + + align:start position:0% +Okay. I like that one, +too. Uh, more. + + align:start position:0% +too. Uh, more. + + + align:start position:0% +too. Uh, more. +What's that? + + align:start position:0% +What's that? + + + align:start position:0% +What's that? +No. Yeah. Starcraft. Starcraft. Which + + align:start position:0% +No. Yeah. Starcraft. Starcraft. Which + + + align:start position:0% +No. Yeah. Starcraft. Starcraft. Which +one? I've only played two. Okay. I + + align:start position:0% +one? I've only played two. Okay. I + + + align:start position:0% +one? I've only played two. Okay. I +played one, but I haven't played two. + + align:start position:0% +played one, but I haven't played two. + + + align:start position:0% +played one, but I haven't played two. +But he plays two a lot. More. + + align:start position:0% +But he plays two a lot. More. + + + align:start position:0% +But he plays two a lot. More. +Fire Emblem. Fire Emblem. Oh, that's a + + align:start position:0% +Fire Emblem. Fire Emblem. Oh, that's a + + + align:start position:0% +Fire Emblem. Fire Emblem. Oh, that's a +really good one. Which one? + + align:start position:0% +really good one. Which one? + + + align:start position:0% +really good one. Which one? +All of them. Yeah. Yeah. Go. + + align:start position:0% +All of them. Yeah. Yeah. Go. + + + align:start position:0% +All of them. Yeah. Yeah. Go. +Go. You took the game to the board game + + align:start position:0% +Go. You took the game to the board game + + + align:start position:0% +Go. You took the game to the board game +class. + + align:start position:0% +class. + + + align:start position:0% +class. +Mobas. Mobas. So, which ones? Like + + align:start position:0% +Mobas. Mobas. So, which ones? Like + + + align:start position:0% +Mobas. Mobas. So, which ones? Like +what's a MOA? Really? + + align:start position:0% +what's a MOA? Really? + + + align:start position:0% +what's a MOA? Really? +Legends. So, what does MOA stand for for + + align:start position:0% +Legends. So, what does MOA stand for for + + + align:start position:0% +Legends. So, what does MOA stand for for +people who haven't played? Massive + + align:start position:0% +people who haven't played? Massive + + + align:start position:0% +people who haven't played? Massive +online. + + align:start position:0% +online. + + + align:start position:0% +online. +Massive online battle arena. Um, and + + align:start position:0% +Massive online battle arena. Um, and + + + align:start position:0% +Massive online battle arena. Um, and +you're talking about League of Legends. + + align:start position:0% +you're talking about League of Legends. + + + align:start position:0% +you're talking about League of Legends. +How many How many people here? Raise + + align:start position:0% +How many How many people here? Raise + + + align:start position:0% +How many How many people here? Raise +your hand if you played League of + + align:start position:0% +your hand if you played League of + + + align:start position:0% +your hand if you played League of +Legends. Okay. Riot's coming September + + align:start position:0% +Legends. Okay. Riot's coming September + + + align:start position:0% +Legends. Okay. Riot's coming September +24th to talk about it. That's about + + align:start position:0% +24th to talk about it. That's about + + + align:start position:0% +24th to talk about it. That's about +that. Um, how many people have played + + align:start position:0% +that. Um, how many people have played + + + align:start position:0% +that. Um, how many people have played +Dota Defense of the + + align:start position:0% +Dota Defense of the + + + align:start position:0% +Dota Defense of the +Ancients? Same people for the most part. + + align:start position:0% +Ancients? Same people for the most part. + + + align:start position:0% +Ancients? Same people for the most part. +Cool. Um, cool. All right. All right. + + align:start position:0% +Cool. Um, cool. All right. All right. + + + align:start position:0% +Cool. Um, cool. All right. All right. +So, that's a really good splud and and + + align:start position:0% +So, that's a really good splud and and + + + align:start position:0% +So, that's a really good splud and and +that's exactly what I expected um except + + align:start position:0% +that's exactly what I expected um except + + + align:start position:0% +that's exactly what I expected um except +for the go person uh to hear + + align:start position:0% +for the go person uh to hear + + + align:start position:0% +for the go person uh to hear +are games about war and games about + + align:start position:0% +are games about war and games about + + + align:start position:0% +are games about war and games about +conflict and games about fighting + + align:start position:0% +conflict and games about fighting + + + align:start position:0% +conflict and games about fighting +against another player or against a + + align:start position:0% +against another player or against a + + + align:start position:0% +against another player or against a +computer-controlled opponent. That's not + + align:start position:0% +computer-controlled opponent. That's not + + + align:start position:0% +computer-controlled opponent. That's not +exactly what we mean when we talk about + + align:start position:0% +exactly what we mean when we talk about + + + align:start position:0% +exactly what we mean when we talk about +strategy games for the broader aspect of + + align:start position:0% +strategy games for the broader aspect of + + + align:start position:0% +strategy games for the broader aspect of +the class, but it's a great place to + + align:start position:0% +the class, but it's a great place to + + + align:start position:0% +the class, but it's a great place to +start and that's where we're going to + + align:start position:0% +start and that's where we're going to + + + align:start position:0% +start and that's where we're going to +start. So, here's Civilization 5 and + + align:start position:0% +start. So, here's Civilization 5 and + + + align:start position:0% +start. So, here's Civilization 5 and +here's Starcraft 2. Um, I'm going to use + + align:start position:0% +here's Starcraft 2. Um, I'm going to use + + + align:start position:0% +here's Starcraft 2. Um, I'm going to use +these for a couple examples and then + + align:start position:0% +these for a couple examples and then + + + align:start position:0% +these for a couple examples and then +we're going to split off and talk about + + align:start position:0% +we're going to split off and talk about + + + align:start position:0% +we're going to split off and talk about +each of us are going to talk about some + + align:start position:0% +each of us are going to talk about some + + + align:start position:0% +each of us are going to talk about some +of our favorite games that we think of + + align:start position:0% +of our favorite games that we think of + + + align:start position:0% +of our favorite games that we think of +when we say this was a really cool + + align:start position:0% +when we say this was a really cool + + + align:start position:0% +when we say this was a really cool +mechanic. This is a really cool thing + + align:start position:0% +mechanic. This is a really cool thing + + + align:start position:0% +mechanic. This is a really cool thing +I've seen in a in a strategy game or an + + align:start position:0% +I've seen in a in a strategy game or an + + + align:start position:0% +I've seen in a in a strategy game or an +aspect of strategy or an aspect of + + align:start position:0% +aspect of strategy or an aspect of + + + align:start position:0% +aspect of strategy or an aspect of +tactics that I've seen and I'd love to + + align:start position:0% +tactics that I've seen and I'd love to + + + align:start position:0% +tactics that I've seen and I'd love to +see happen in some of the games we make + + align:start position:0% +see happen in some of the games we make + + + align:start position:0% +see happen in some of the games we make +um over the next + + align:start position:0% +um over the next + + + align:start position:0% +um over the next +semester. So, there's two types of + + align:start position:0% +semester. So, there's two types of + + + align:start position:0% +semester. So, there's two types of +decision-m that I see um and again, this + + align:start position:0% +decision-m that I see um and again, this + + + align:start position:0% +decision-m that I see um and again, this +is all just me in my head a couple days + + align:start position:0% +is all just me in my head a couple days + + + align:start position:0% +is all just me in my head a couple days +ago putting a lecture together. It's + + align:start position:0% +ago putting a lecture together. It's + + + align:start position:0% +ago putting a lecture together. It's +not, you know, an academic taxonomy. + + align:start position:0% +not, you know, an academic taxonomy. + + + align:start position:0% +not, you know, an academic taxonomy. +It's to help us out with when we're + + align:start position:0% +It's to help us out with when we're + + + align:start position:0% +It's to help us out with when we're +thinking about the kinds of decisions + + align:start position:0% +thinking about the kinds of decisions + + + align:start position:0% +thinking about the kinds of decisions +we're we're making in these games. + + align:start position:0% +we're we're making in these games. + + + align:start position:0% +we're we're making in these games. +There's two kinds of decisions that + + align:start position:0% +There's two kinds of decisions that + + + align:start position:0% +There's two kinds of decisions that +happen in these games. There's a + + align:start position:0% +happen in these games. There's a + + + align:start position:0% +happen in these games. There's a +microlevel decision, short-term + + align:start position:0% +microlevel decision, short-term + + + align:start position:0% +microlevel decision, short-term +decisions I make that help me out right + + align:start position:0% +decisions I make that help me out right + + + align:start position:0% +decisions I make that help me out right +now. Um, there's macro so um decisions + + align:start position:0% +now. Um, there's macro so um decisions + + + align:start position:0% +now. Um, there's macro so um decisions +or long-term decisions, and I'm using + + align:start position:0% +or long-term decisions, and I'm using + + + align:start position:0% +or long-term decisions, and I'm using +macro micro and macro because I'm + + align:start position:0% +macro micro and macro because I'm + + + align:start position:0% +macro micro and macro because I'm +obsessed with economics even though I + + align:start position:0% +obsessed with economics even though I + + + align:start position:0% +obsessed with economics even though I +don't understand it, but also because + + align:start position:0% +don't understand it, but also because + + + align:start position:0% +don't understand it, but also because +you you see the games represented that + + align:start position:0% +you you see the games represented that + + + align:start position:0% +you you see the games represented that +way. Sometimes there's the micro where + + align:start position:0% +way. Sometimes there's the micro where + + + align:start position:0% +way. Sometimes there's the micro where +I'm looking really tight at this one + + align:start position:0% +I'm looking really tight at this one + + + align:start position:0% +I'm looking really tight at this one +aspect of the game and the macro where I + + align:start position:0% +aspect of the game and the macro where I + + + align:start position:0% +aspect of the game and the macro where I +can see a bigger expanded version of the + + align:start position:0% +can see a bigger expanded version of the + + + align:start position:0% +can see a bigger expanded version of the +world. I can see the systems and the + + align:start position:0% +world. I can see the systems and the + + + align:start position:0% +world. I can see the systems and the +gears that are happening behind the + + align:start position:0% +gears that are happening behind the + + + align:start position:0% +gears that are happening behind the +world. Um, and they and they're they're + + align:start position:0% +world. Um, and they and they're they're + + + align:start position:0% +world. Um, and they and they're they're +represented in many ways and I'll I'll + + align:start position:0% +represented in many ways and I'll I'll + + + align:start position:0% +represented in many ways and I'll I'll +talk about a couple examples there. + + align:start position:0% +talk about a couple examples there. + + + align:start position:0% +talk about a couple examples there. +People often use tactics to describe + + align:start position:0% +People often use tactics to describe + + + align:start position:0% +People often use tactics to describe +micro and strategy to describe macro. + + align:start position:0% +micro and strategy to describe macro. + + + align:start position:0% +micro and strategy to describe macro. +There's actually a difference between + + align:start position:0% +There's actually a difference between + + + align:start position:0% +There's actually a difference between +strategy and tactics and that's one way + + align:start position:0% +strategy and tactics and that's one way + + + align:start position:0% +strategy and tactics and that's one way +to think about it. Yep. + + align:start position:0% +to think about it. Yep. + + + align:start position:0% +to think about it. Yep. +So for the micro exactly tactical + + align:start position:0% +So for the micro exactly tactical + + + align:start position:0% +So for the micro exactly tactical +um the the way this is often represented + + align:start position:0% +um the the way this is often represented + + + align:start position:0% +um the the way this is often represented +in in these kind of war games and + + align:start position:0% +in in these kind of war games and + + + align:start position:0% +in in these kind of war games and +strategy games there's usually some kind + + align:start position:0% +strategy games there's usually some kind + + + align:start position:0% +strategy games there's usually some kind +of spatial component going on some kind + + align:start position:0% +of spatial component going on some kind + + + align:start position:0% +of spatial component going on some kind +of placement going on. Um there might be + + align:start position:0% +of placement going on. Um there might be + + + align:start position:0% +of placement going on. Um there might be +some direct conflict happening. So I've + + align:start position:0% +some direct conflict happening. So I've + + + align:start position:0% +some direct conflict happening. So I've +got an army and it's facing off another + + align:start position:0% +got an army and it's facing off another + + + align:start position:0% +got an army and it's facing off another +army and we're throwing spears or + + align:start position:0% +army and we're throwing spears or + + + align:start position:0% +army and we're throwing spears or +shooting each other with lasers. Um + + align:start position:0% +shooting each other with lasers. Um + + + align:start position:0% +shooting each other with lasers. Um +basically the same thing. Um but there's + + align:start position:0% +basically the same thing. Um but there's + + + align:start position:0% +basically the same thing. Um but there's +also firefighting. There's another kind + + align:start position:0% +also firefighting. There's another kind + + + align:start position:0% +also firefighting. There's another kind +of conflict that happens on and + + align:start position:0% +of conflict that happens on and + + + align:start position:0% +of conflict that happens on and +firefighting. I don't mean like fires, + + align:start position:0% +firefighting. I don't mean like fires, + + + align:start position:0% +firefighting. I don't mean like fires, +but I've got a problem that just + + align:start position:0% +but I've got a problem that just + + + align:start position:0% +but I've got a problem that just +happened and I need to solve it. I need + + align:start position:0% +happened and I need to solve it. I need + + + align:start position:0% +happened and I need to solve it. I need +to react to it. So, it's it's reactive. + + align:start position:0% +to react to it. So, it's it's reactive. + + + align:start position:0% +to react to it. So, it's it's reactive. +Um, I might have this really long + + align:start position:0% +Um, I might have this really long + + + align:start position:0% +Um, I might have this really long +longterm strategy, but unfortunately, + + align:start position:0% +longterm strategy, but unfortunately, + + + align:start position:0% +longterm strategy, but unfortunately, +I've got to make some decisions right + + align:start position:0% +I've got to make some decisions right + + + align:start position:0% +I've got to make some decisions right +now that may or may not hurt my + + align:start position:0% +now that may or may not hurt my + + + align:start position:0% +now that may or may not hurt my +long-term strategy. There's some + + align:start position:0% +long-term strategy. There's some + + + align:start position:0% +long-term strategy. There's some +tactical decisions I need to make. + + align:start position:0% +tactical decisions I need to make. + + + align:start position:0% +tactical decisions I need to make. +Um, it's not always reactive, though. + + align:start position:0% +Um, it's not always reactive, though. + + + align:start position:0% +Um, it's not always reactive, though. +Sometimes what what we're talking about + + align:start position:0% +Sometimes what what we're talking about + + + align:start position:0% +Sometimes what what we're talking about +is you're executing a plan. I've set up + + align:start position:0% +is you're executing a plan. I've set up + + + align:start position:0% +is you're executing a plan. I've set up +a long-term strategy and now here's the + + align:start position:0% +a long-term strategy and now here's the + + + align:start position:0% +a long-term strategy and now here's the +final dramatic moment where I get to + + align:start position:0% +final dramatic moment where I get to + + + align:start position:0% +final dramatic moment where I get to +actually implement the thing and see if + + align:start position:0% +actually implement the thing and see if + + + align:start position:0% +actually implement the thing and see if +it works. Um, throw the throw the the + + align:start position:0% +it works. Um, throw the throw the the + + + align:start position:0% +it works. Um, throw the throw the the +dudes on the map and they're going to + + align:start position:0% +dudes on the map and they're going to + + + align:start position:0% +dudes on the map and they're going to +die or not. Um, and when we're talking + + align:start position:0% +die or not. Um, and when we're talking + + + align:start position:0% +die or not. Um, and when we're talking +about tactical, there's a there's always + + align:start position:0% +about tactical, there's a there's always + + + align:start position:0% +about tactical, there's a there's always +a short-term resolution. So, I do a + + align:start position:0% +a short-term resolution. So, I do a + + + align:start position:0% +a short-term resolution. So, I do a +thing, feedback. I know what happened. + + align:start position:0% +thing, feedback. I know what happened. + + + align:start position:0% +thing, feedback. I know what happened. +There could be long-term ramifications, + + align:start position:0% +There could be long-term ramifications, + + + align:start position:0% +There could be long-term ramifications, +but there's definitely a short-term + + align:start position:0% +but there's definitely a short-term + + + align:start position:0% +but there's definitely a short-term +resolution to the decision I just made + + align:start position:0% +resolution to the decision I just made + + + align:start position:0% +resolution to the decision I just made +at that point. So, my example, because + + align:start position:0% +at that point. So, my example, because + + + align:start position:0% +at that point. So, my example, because +I'm a huge um Civilization nerd, um + + align:start position:0% +I'm a huge um Civilization nerd, um + + + align:start position:0% +I'm a huge um Civilization nerd, um +Civil Civilization 5 um brought some + + align:start position:0% +Civil Civilization 5 um brought some + + + align:start position:0% +Civil Civilization 5 um brought some +very tactical gameplay to the series + + align:start position:0% +very tactical gameplay to the series + + + align:start position:0% +very tactical gameplay to the series +that wasn't really there in the in in + + align:start position:0% +that wasn't really there in the in in + + + align:start position:0% +that wasn't really there in the in in +previous installments. Um so, in the + + align:start position:0% +previous installments. Um so, in the + + + align:start position:0% +previous installments. Um so, in the +past, you could stack units on a tile. + + align:start position:0% +past, you could stack units on a tile. + + + align:start position:0% +past, you could stack units on a tile. +So, Civilization is basically a game + + align:start position:0% +So, Civilization is basically a game + + + align:start position:0% +So, Civilization is basically a game +made of tiles where you're placing items + + align:start position:0% +made of tiles where you're placing items + + + align:start position:0% +made of tiles where you're placing items +on tiles and the tiles give you bonuses + + align:start position:0% +on tiles and the tiles give you bonuses + + + align:start position:0% +on tiles and the tiles give you bonuses +or whatnot. + + align:start position:0% +or whatnot. + + + align:start position:0% +or whatnot. +Um very, very basic version of it. In + + align:start position:0% +Um very, very basic version of it. In + + + align:start position:0% +Um very, very basic version of it. In +this case, what we have, and it's kind + + align:start position:0% +this case, what we have, and it's kind + + + align:start position:0% +this case, what we have, and it's kind +of blurry, but you have a city in the + + align:start position:0% +of blurry, but you have a city in the + + + align:start position:0% +of blurry, but you have a city in the +center where that arrow is pointing to. + + align:start position:0% +center where that arrow is pointing to. + + + align:start position:0% +center where that arrow is pointing to. +You have these blue units surrounding + + align:start position:0% +You have these blue units surrounding + + + align:start position:0% +You have these blue units surrounding +the city and a couple small yellow units + + align:start position:0% +the city and a couple small yellow units + + + align:start position:0% +the city and a couple small yellow units +going on. Um, can anybody describe + + align:start position:0% +going on. Um, can anybody describe + + + align:start position:0% +going on. Um, can anybody describe +what's going on in the scene? + + align:start position:0% +what's going on in the scene? + + + align:start position:0% +what's going on in the scene? +What's that? A raid. So, we're fighting + + align:start position:0% +What's that? A raid. So, we're fighting + + + align:start position:0% +What's that? A raid. So, we're fighting +the we're we're fighting. What kind of + + align:start position:0% +the we're we're fighting. What kind of + + + align:start position:0% +the we're we're fighting. What kind of +decisions is a player being asked to do + + align:start position:0% +decisions is a player being asked to do + + + align:start position:0% +decisions is a player being asked to do +right + + align:start position:0% +right + + + align:start position:0% +right +now? And the player is the the blue + + align:start position:0% +now? And the player is the the blue + + + align:start position:0% +now? And the player is the the blue +player that has the red arrow there. + + align:start position:0% +player that has the red arrow there. + + + align:start position:0% +player that has the red arrow there. +What's that? + + align:start position:0% +What's that? + + + align:start position:0% +What's that? +So yeah, you're trying to implement the + + align:start position:0% +So yeah, you're trying to implement the + + + align:start position:0% +So yeah, you're trying to implement the +strategy. Do you can you kind of see and + + align:start position:0% +strategy. Do you can you kind of see and + + + align:start position:0% +strategy. Do you can you kind of see and +apologies if you can't make out the the + + align:start position:0% +apologies if you can't make out the the + + + align:start position:0% +apologies if you can't make out the the +the quality of the video, the slide. Can + + align:start position:0% +the quality of the video, the slide. Can + + + align:start position:0% +the quality of the video, the slide. Can +you see what um is exactly going on? + + align:start position:0% +you see what um is exactly going on? + + + align:start position:0% +you see what um is exactly going on? +Yeah, they're about to make a ranged + + align:start position:0% +Yeah, they're about to make a ranged + + + align:start position:0% +Yeah, they're about to make a ranged +attack against the city. Yeah. So, first + + align:start position:0% +attack against the city. Yeah. So, first + + + align:start position:0% +attack against the city. Yeah. So, first +thing is all right. So, I've got a um + + align:start position:0% +thing is all right. So, I've got a um + + + align:start position:0% +thing is all right. So, I've got a um +ranged attack that is two, it's really + + align:start position:0% +ranged attack that is two, it's really + + + align:start position:0% +ranged attack that is two, it's really +diagonally away from the city. Um it's + + align:start position:0% +diagonally away from the city. Um it's + + + align:start position:0% +diagonally away from the city. Um it's +two hex's away. I can do a range attack + + align:start position:0% +two hex's away. I can do a range attack + + + align:start position:0% +two hex's away. I can do a range attack +on it. The cool thing about this is that + + align:start position:0% +on it. The cool thing about this is that + + + align:start position:0% +on it. The cool thing about this is that +the city can't attack me right now. Um + + align:start position:0% +the city can't attack me right now. Um + + + align:start position:0% +the city can't attack me right now. Um +well, actually it can, but I I'm making + + align:start position:0% +well, actually it can, but I I'm making + + + align:start position:0% +well, actually it can, but I I'm making +a mistake there. But the the it's not + + align:start position:0% +a mistake there. But the the it's not + + + align:start position:0% +a mistake there. But the the it's not +the knight's turn, so the knight can't + + align:start position:0% +the knight's turn, so the knight can't + + + align:start position:0% +the knight's turn, so the knight can't +attack the the ranged attack right now. + + align:start position:0% +attack the the ranged attack right now. + + + align:start position:0% +attack the the ranged attack right now. +The other thing that's happening is the + + align:start position:0% +The other thing that's happening is the + + + align:start position:0% +The other thing that's happening is the +player ex had a long-term strategy, + + align:start position:0% +player ex had a long-term strategy, + + + align:start position:0% +player ex had a long-term strategy, +which meant that they brought some foot + + align:start position:0% +which meant that they brought some foot + + + align:start position:0% +which meant that they brought some foot +soldiers in to surround the city + + align:start position:0% +soldiers in to surround the city + + + align:start position:0% +soldiers in to surround the city +protecting the ranged um attacker. Um, + + align:start position:0% +protecting the ranged um attacker. Um, + + + align:start position:0% +protecting the ranged um attacker. Um, +they've also got this thing called zone + + align:start position:0% +they've also got this thing called zone + + + align:start position:0% +they've also got this thing called zone +of control going on in this where + + align:start position:0% +of control going on in this where + + + align:start position:0% +of control going on in this where +there's + + align:start position:0% +there's + + + align:start position:0% +there's +a All + + align:start position:0% +a All + + + align:start position:0% +a All +right, here's a here's a a enemy person. + + align:start position:0% +right, here's a here's a a enemy person. + + + align:start position:0% +right, here's a here's a a enemy person. +Here's an enemy person. Here's an enemy + + align:start position:0% +Here's an enemy person. Here's an enemy + + + align:start position:0% +Here's an enemy person. Here's an enemy +person. If any of these people try to + + align:start position:0% +person. If any of these people try to + + + align:start position:0% +person. If any of these people try to +attack any of these blue people, there's + + align:start position:0% +attack any of these blue people, there's + + + align:start position:0% +attack any of these blue people, there's +some kind of um negative modifier going + + align:start position:0% +some kind of um negative modifier going + + + align:start position:0% +some kind of um negative modifier going +on because the blue the blue player has + + align:start position:0% +on because the blue the blue player has + + + align:start position:0% +on because the blue the blue player has +set it up such that they're flank + + align:start position:0% +set it up such that they're flank + + + align:start position:0% +set it up such that they're flank +they're being flanked. So, there's some + + align:start position:0% +they're being flanked. So, there's some + + + align:start position:0% +they're being flanked. So, there's some +spatial placement going on that that's + + align:start position:0% +spatial placement going on that that's + + + align:start position:0% +spatial placement going on that that's +been decided. Not only did they have to + + align:start position:0% +been decided. Not only did they have to + + + align:start position:0% +been decided. Not only did they have to +get all the units over here, but once + + align:start position:0% +get all the units over here, but once + + + align:start position:0% +get all the units over here, but once +they were here, they had to put those + + align:start position:0% +they were here, they had to put those + + + align:start position:0% +they were here, they had to put those +units in the right places for this long + + align:start position:0% +units in the right places for this long + + + align:start position:0% +units in the right places for this long +for this this tactical um uh maneuver to + + align:start position:0% +for this this tactical um uh maneuver to + + + align:start position:0% +for this this tactical um uh maneuver to +happen. + + align:start position:0% +happen. + + + align:start position:0% +happen. +Um so really in Civilization 5, we've + + align:start position:0% +Um so really in Civilization 5, we've + + + align:start position:0% +Um so really in Civilization 5, we've +talked about tactical in one aspect of + + align:start position:0% +talked about tactical in one aspect of + + + align:start position:0% +talked about tactical in one aspect of +it. In the combat aspect of it, we're + + align:start position:0% +it. In the combat aspect of it, we're + + + align:start position:0% +it. In the combat aspect of it, we're +talking about flanking, army + + align:start position:0% +talking about flanking, army + + + align:start position:0% +talking about flanking, army +positioning, zone of control, um pre + + align:start position:0% +positioning, zone of control, um pre + + + align:start position:0% +positioning, zone of control, um pre +preventing other players from entering + + align:start position:0% +preventing other players from entering + + + align:start position:0% +preventing other players from entering +into tiles, controlling areas, and + + align:start position:0% +into tiles, controlling areas, and + + + align:start position:0% +into tiles, controlling areas, and +making the making this area basically + + align:start position:0% +making the making this area basically + + + align:start position:0% +making the making this area basically +more effective for the blue player to to + + align:start position:0% +more effective for the blue player to to + + + align:start position:0% +more effective for the blue player to to +attack the city than for the the yellow + + align:start position:0% +attack the city than for the the yellow + + + align:start position:0% +attack the city than for the the yellow +player to defend + + align:start position:0% +player to defend + + + align:start position:0% +player to defend +it. So, how did the player get there? + + align:start position:0% +it. So, how did the player get there? + + + align:start position:0% +it. So, how did the player get there? +How did blue how did blue get into that + + align:start position:0% +How did blue how did blue get into that + + + align:start position:0% +How did blue how did blue get into that +into that situation? they had an + + align:start position:0% +into that situation? they had an + + + align:start position:0% +into that situation? they had an +operational or strategic um plan that + + align:start position:0% +operational or strategic um plan that + + + align:start position:0% +operational or strategic um plan that +they set forth. They were able to + + align:start position:0% +they set forth. They were able to + + + align:start position:0% +they set forth. They were able to +develop those those weapons that they + + align:start position:0% +develop those those weapons that they + + + align:start position:0% +develop those those weapons that they +had. They were able to make them in the + + align:start position:0% +had. They were able to make them in the + + + align:start position:0% +had. They were able to make them in the +right location and then they were able + + align:start position:0% +right location and then they were able + + + align:start position:0% +right location and then they were able +to transport them over to the right um + + align:start position:0% +to transport them over to the right um + + + align:start position:0% +to transport them over to the right um +location. So, if we're talking about + + align:start position:0% +location. So, if we're talking about + + + align:start position:0% +location. So, if we're talking about +military tact uh military strategy + + align:start position:0% +military tact uh military strategy + + + align:start position:0% +military tact uh military strategy +tactics, um that might be closer to + + align:start position:0% +tactics, um that might be closer to + + + align:start position:0% +tactics, um that might be closer to +uh logistics um supply chain getting + + align:start position:0% +uh logistics um supply chain getting + + + align:start position:0% +uh logistics um supply chain getting +getting supply into the area. Um, the + + align:start position:0% +getting supply into the area. Um, the + + + align:start position:0% +getting supply into the area. Um, the +strategy that might actually be + + align:start position:0% +strategy that might actually be + + + align:start position:0% +strategy that might actually be +happening is even bigger than that. So, + + align:start position:0% +happening is even bigger than that. So, + + + align:start position:0% +happening is even bigger than that. So, +this is where it gets into the realm + + align:start position:0% +this is where it gets into the realm + + + align:start position:0% +this is where it gets into the realm +that I really nerd out in is + + align:start position:0% +that I really nerd out in is + + + align:start position:0% +that I really nerd out in is +spreadsheets of numbers and modifiers. + + align:start position:0% +spreadsheets of numbers and modifiers. + + + align:start position:0% +spreadsheets of numbers and modifiers. +There's ma resources you need to manage. + + align:start position:0% +There's ma resources you need to manage. + + + align:start position:0% +There's ma resources you need to manage. +There's um I need to anticipate what's + + align:start position:0% +There's um I need to anticipate what's + + + align:start position:0% +There's um I need to anticipate what's +going to be there and have the right + + align:start position:0% +going to be there and have the right + + + align:start position:0% +going to be there and have the right +things built in time for them to to be + + align:start position:0% +things built in time for them to to be + + + align:start position:0% +things built in time for them to to be +useful in that situation. Um, there's an + + align:start position:0% +useful in that situation. Um, there's an + + + align:start position:0% +useful in that situation. Um, there's an +economic system I need to manipulate and + + align:start position:0% +economic system I need to manipulate and + + + align:start position:0% +economic system I need to manipulate and +and do well with in order to afford the + + align:start position:0% +and do well with in order to afford the + + + align:start position:0% +and do well with in order to afford the +units that I want over there. I need to + + align:start position:0% +units that I want over there. I need to + + + align:start position:0% +units that I want over there. I need to +be pro if I'm playing well, I need to be + + align:start position:0% +be pro if I'm playing well, I need to be + + + align:start position:0% +be pro if I'm playing well, I need to be +proactive in my strategy. All strategy + + align:start position:0% +proactive in my strategy. All strategy + + + align:start position:0% +proactive in my strategy. All strategy +really should be proactive. And somebody + + align:start position:0% +really should be proactive. And somebody + + + align:start position:0% +really should be proactive. And somebody +can can argue with me if there is such a + + align:start position:0% +can can argue with me if there is such a + + + align:start position:0% +can can argue with me if there is such a +thing as reactive strategy, but really + + align:start position:0% +thing as reactive strategy, but really + + + align:start position:0% +thing as reactive strategy, but really +it could be proactive and wrong, but you + + align:start position:0% +it could be proactive and wrong, but you + + + align:start position:0% +it could be proactive and wrong, but you +you you did it beforehand. You set up + + align:start position:0% +you you did it beforehand. You set up + + + align:start position:0% +you you did it beforehand. You set up +the the the gears in motion for it to to + + align:start position:0% +the the the gears in motion for it to to + + + align:start position:0% +the the the gears in motion for it to to +play out the way it did, and you're + + align:start position:0% +play out the way it did, and you're + + + align:start position:0% +play out the way it did, and you're +always planning for some long-term + + align:start position:0% +always planning for some long-term + + + align:start position:0% +always planning for some long-term +future. So, in Civilization 5, one way + + align:start position:0% +future. So, in Civilization 5, one way + + + align:start position:0% +future. So, in Civilization 5, one way +that this plays out non-combat is city + + align:start position:0% +that this plays out non-combat is city + + + align:start position:0% +that this plays out non-combat is city +placement. Where I can place my where I + + align:start position:0% +placement. Where I can place my where I + + + align:start position:0% +placement. Where I can place my where I +I put my city is incredibly important. + + align:start position:0% +I put my city is incredibly important. + + + align:start position:0% +I put my city is incredibly important. +Here's a using the real world map of + + align:start position:0% +Here's a using the real world map of + + + align:start position:0% +Here's a using the real world map of +Africa. So, they what they've done is um + + align:start position:0% +Africa. So, they what they've done is um + + + align:start position:0% +Africa. So, they what they've done is um +the designers put um these resources, + + align:start position:0% +the designers put um these resources, + + + align:start position:0% +the designers put um these resources, +those spher those circular items, + + align:start position:0% +those spher those circular items, + + + align:start position:0% +those spher those circular items, +spices, bananas, silk, diamonds, oil. + + align:start position:0% +spices, bananas, silk, diamonds, oil. + + + align:start position:0% +spices, bananas, silk, diamonds, oil. +The resources, some of them are are are + + align:start position:0% +The resources, some of them are are are + + + align:start position:0% +The resources, some of them are are are +luxury resources. So, they help my + + align:start position:0% +luxury resources. So, they help my + + + align:start position:0% +luxury resources. So, they help my +cities be be happy. They help my + + align:start position:0% +cities be be happy. They help my + + + align:start position:0% +cities be be happy. They help my +citizens work well and be productive. + + align:start position:0% +citizens work well and be productive. + + + align:start position:0% +citizens work well and be productive. +Um, there's uh uh agricultural resources + + align:start position:0% +Um, there's uh uh agricultural resources + + + align:start position:0% +Um, there's uh uh agricultural resources +that help my cities grow and be healthy. + + align:start position:0% +that help my cities grow and be healthy. + + + align:start position:0% +that help my cities grow and be healthy. +And then there's um strategic resources, + + align:start position:0% +And then there's um strategic resources, + + + align:start position:0% +And then there's um strategic resources, +and I could be mixing these terms up + + align:start position:0% +and I could be mixing these terms up + + + align:start position:0% +and I could be mixing these terms up +where there things that are going to + + align:start position:0% +where there things that are going to + + + align:start position:0% +where there things that are going to +help me build things. Um, so oil or + + align:start position:0% +help me build things. Um, so oil or + + + align:start position:0% +help me build things. Um, so oil or +steel or iron will help me build better + + align:start position:0% +steel or iron will help me build better + + + align:start position:0% +steel or iron will help me build better +units. + + align:start position:0% +units. + + + align:start position:0% +units. +Um, so my strategy here, there's a + + align:start position:0% +Um, so my strategy here, there's a + + + align:start position:0% +Um, so my strategy here, there's a +little bit of tactics going on where + + align:start position:0% +little bit of tactics going on where + + + align:start position:0% +little bit of tactics going on where +when I actually get my settler in the + + align:start position:0% +when I actually get my settler in the + + + align:start position:0% +when I actually get my settler in the +right place, I need to then find a very + + align:start position:0% +right place, I need to then find a very + + + align:start position:0% +right place, I need to then find a very +specific place to to go. Um, but long + + align:start position:0% +specific place to to go. Um, but long + + + align:start position:0% +specific place to to go. Um, but long +term, if I'm thinking about the long + + align:start position:0% +term, if I'm thinking about the long + + + align:start position:0% +term, if I'm thinking about the long +term, I want to place my cities in a + + align:start position:0% +term, I want to place my cities in a + + + align:start position:0% +term, I want to place my cities in a +place in a way where they're near + + align:start position:0% +place in a way where they're near + + + align:start position:0% +place in a way where they're near +resources, they're near my friendly + + align:start position:0% +resources, they're near my friendly + + + align:start position:0% +resources, they're near my friendly +cities, they have room to grow, because + + align:start position:0% +cities, they have room to grow, because + + + align:start position:0% +cities, they have room to grow, because +if I group my cities too close to each + + align:start position:0% +if I group my cities too close to each + + + align:start position:0% +if I group my cities too close to each +other, they're not going to be as + + align:start position:0% +other, they're not going to be as + + + align:start position:0% +other, they're not going to be as +efficient. This is really apparent when + + align:start position:0% +efficient. This is really apparent when + + + align:start position:0% +efficient. This is really apparent when +if anybody's played Civilization 2 um + + align:start position:0% +if anybody's played Civilization 2 um + + + align:start position:0% +if anybody's played Civilization 2 um +where the there's one real strategy to + + align:start position:0% +where the there's one real strategy to + + + align:start position:0% +where the there's one real strategy to +the game and that's just build a city + + align:start position:0% +the game and that's just build a city + + + align:start position:0% +the game and that's just build a city +every three hex's just that's just how + + align:start position:0% +every three hex's just that's just how + + + align:start position:0% +every three hex's just that's just how +it works. In the later games they try to + + align:start position:0% +it works. In the later games they try to + + + align:start position:0% +it works. In the later games they try to +introduce some nuance to + + align:start position:0% +introduce some nuance to + + + align:start position:0% +introduce some nuance to +that. + + align:start position:0% +that. + + + align:start position:0% +that. +Um so and again I'm mixing up strate I'm + + align:start position:0% +Um so and again I'm mixing up strate I'm + + + align:start position:0% +Um so and again I'm mixing up strate I'm +mixing strategy and tactics as we're + + align:start position:0% +mixing strategy and tactics as we're + + + align:start position:0% +mixing strategy and tactics as we're +talking about this. They all go hand in + + align:start position:0% +talking about this. They all go hand in + + + align:start position:0% +talking about this. They all go hand in +hand. A lot of the games that we've + + align:start position:0% +hand. A lot of the games that we've + + + align:start position:0% +hand. A lot of the games that we've +played and that we talk that that are + + align:start position:0% +played and that we talk that that are + + + align:start position:0% +played and that we talk that that are +these strategy games that you talked + + align:start position:0% +these strategy games that you talked + + + align:start position:0% +these strategy games that you talked +about are actually more tactical games. + + align:start position:0% +about are actually more tactical games. + + + align:start position:0% +about are actually more tactical games. +There's much more emphasis placed on the + + align:start position:0% +There's much more emphasis placed on the + + + align:start position:0% +There's much more emphasis placed on the +shortterm thing I do now than the long + + align:start position:0% +shortterm thing I do now than the long + + + align:start position:0% +shortterm thing I do now than the long +term. Um that's not to say there isn't + + align:start position:0% +term. Um that's not to say there isn't + + + align:start position:0% +term. Um that's not to say there isn't +long term in these games. Um if + + align:start position:0% +long term in these games. Um if + + + align:start position:0% +long term in these games. Um if +anybody's um played like League of + + align:start position:0% +anybody's um played like League of + + + align:start position:0% +anybody's um played like League of +Legends the meta about the metag game + + align:start position:0% +Legends the meta about the metag game + + + align:start position:0% +Legends the meta about the metag game +about the how the pick process, so what + + align:start position:0% +about the how the pick process, so what + + + align:start position:0% +about the how the pick process, so what +champ to pick or not um that's a + + align:start position:0% +champ to pick or not um that's a + + + align:start position:0% +champ to pick or not um that's a +strategic maneuver. That's a that's a + + align:start position:0% +strategic maneuver. That's a that's a + + + align:start position:0% +strategic maneuver. That's a that's a +you are planning for a long-term + + align:start position:0% +you are planning for a long-term + + + align:start position:0% +you are planning for a long-term +strategy that's going to that you're + + align:start position:0% +strategy that's going to that you're + + + align:start position:0% +strategy that's going to that you're +going to play out within the game. And + + align:start position:0% +going to play out within the game. And + + + align:start position:0% +going to play out within the game. And +not only are you planning for it, you + + align:start position:0% +not only are you planning for it, you + + + align:start position:0% +not only are you planning for it, you +picked it and then you're stuck with it. + + align:start position:0% +picked it and then you're stuck with it. + + + align:start position:0% +picked it and then you're stuck with it. +Those decisions last. Um with Starcraft + + align:start position:0% +Those decisions last. Um with Starcraft + + + align:start position:0% +Those decisions last. Um with Starcraft +2, it's build order, which can be a + + align:start position:0% +2, it's build order, which can be a + + + align:start position:0% +2, it's build order, which can be a +little bit more flexible. There are + + align:start position:0% +little bit more flexible. There are + + + align:start position:0% +little bit more flexible. There are +build orders that you can that's build + + align:start position:0% +build orders that you can that's build + + + align:start position:0% +build orders that you can that's build +order in that you are building units in + + align:start position:0% +order in that you are building units in + + + align:start position:0% +order in that you are building units in +and and buildings and upgrades in the + + align:start position:0% +and and buildings and upgrades in the + + + align:start position:0% +and and buildings and upgrades in the +right order such that you're prepared + + align:start position:0% +right order such that you're prepared + + + align:start position:0% +right order such that you're prepared +for multiple different strategies coming + + align:start position:0% +for multiple different strategies coming + + + align:start position:0% +for multiple different strategies coming +into you. And I'm could be butchering + + align:start position:0% +into you. And I'm could be butchering + + + align:start position:0% +into you. And I'm could be butchering +that. I'm not a that's + + align:start position:0% +that. I'm not a that's + + + align:start position:0% +that. I'm not a that's +cool. Um, but that's more flexible + + align:start position:0% +cool. Um, but that's more flexible + + + align:start position:0% +cool. Um, but that's more flexible +because I actually I have time within + + align:start position:0% +because I actually I have time within + + + align:start position:0% +because I actually I have time within +the game to to make some tactical + + align:start position:0% +the game to to make some tactical + + + align:start position:0% +the game to to make some tactical +changes to that long-term strategy that + + align:start position:0% +changes to that long-term strategy that + + + align:start position:0% +changes to that long-term strategy that +I that I decided on early. Unless you're + + align:start position:0% +I that I decided on early. Unless you're + + + align:start position:0% +I that I decided on early. Unless you're +playing professionally and then I've + + align:start position:0% +playing professionally and then I've + + + align:start position:0% +playing professionally and then I've +just seen that they just GG after 5 + + align:start position:0% + + + + align:start position:0% + +minutes. So, anybody recognize this + + align:start position:0% +minutes. So, anybody recognize this + + + align:start position:0% +minutes. So, anybody recognize this +quote? + + align:start position:0% +quote? + + + align:start position:0% +quote? +Sidmer developer for civilization + + align:start position:0% +Sidmer developer for civilization + + + align:start position:0% +Sidmer developer for civilization +famously said a good game is a series of + + align:start position:0% +famously said a good game is a series of + + + align:start position:0% +famously said a good game is a series of +interesting choices. Uh it's very much + + align:start position:0% +interesting choices. Uh it's very much + + + align:start position:0% +interesting choices. Uh it's very much +the case for the games that we're making + + align:start position:0% +the case for the games that we're making + + + align:start position:0% +the case for the games that we're making +in this class. The thing I want to note + + align:start position:0% +in this class. The thing I want to note + + + align:start position:0% +in this class. The thing I want to note +is strive for interesting choices in + + align:start position:0% +is strive for interesting choices in + + + align:start position:0% +is strive for interesting choices in +your games. Be prepared for your for + + align:start position:0% +your games. Be prepared for your for + + + align:start position:0% +your games. Be prepared for your for +your choices not to be interesting. Try + + align:start position:0% +your choices not to be interesting. Try + + + align:start position:0% +your choices not to be interesting. Try +to iterate through them and make them + + align:start position:0% +to iterate through them and make them + + + align:start position:0% +to iterate through them and make them +more + + align:start position:0% +more + + + align:start position:0% +more +interesting. But we're not we don't have + + align:start position:0% +interesting. But we're not we don't have + + + align:start position:0% +interesting. But we're not we don't have +a ton of time to really help you make + + align:start position:0% +a ton of time to really help you make + + + align:start position:0% +a ton of time to really help you make +like the greatest games in the world, + + align:start position:0% +like the greatest games in the world, + + + align:start position:0% +like the greatest games in the world, +right? So, we want our your choices to + + align:start position:0% +right? So, we want our your choices to + + + align:start position:0% +right? So, we want our your choices to +be meaningful. And if one or two of them + + align:start position:0% +be meaningful. And if one or two of them + + + align:start position:0% +be meaningful. And if one or two of them +are interesting, awesome. You did a + + align:start position:0% +are interesting, awesome. You did a + + + align:start position:0% +are interesting, awesome. You did a +really really good job um with with the + + align:start position:0% +really really good job um with with the + + + align:start position:0% +really really good job um with with the +game development process of it. Um I'm + + align:start position:0% +game development process of it. Um I'm + + + align:start position:0% +game development process of it. Um I'm +going to do a really really quick talk + + align:start position:0% +going to do a really really quick talk + + + align:start position:0% +going to do a really really quick talk +about how you can make things + + align:start position:0% +about how you can make things + + + align:start position:0% +about how you can make things +interesting and we're going to come back + + align:start position:0% +interesting and we're going to come back + + + align:start position:0% +interesting and we're going to come back +to it in later projects, but I just want + + align:start position:0% +to it in later projects, but I just want + + + align:start position:0% +to it in later projects, but I just want +to get kind of get these two terms out + + align:start position:0% +to get kind of get these two terms out + + + align:start position:0% +to get kind of get these two terms out +there. Um we're going to talk about + + align:start position:0% +there. Um we're going to talk about + + + align:start position:0% +there. Um we're going to talk about +conflict and + + align:start position:0% +conflict and + + + align:start position:0% +conflict and +tension. Uh + + align:start position:0% +tension. Uh + + + align:start position:0% +tension. Uh +so what do we what is conflict? like + + align:start position:0% +so what do we what is conflict? like + + + align:start position:0% +so what do we what is conflict? like +what can what can you think when I if I + + align:start position:0% +what can what can you think when I if I + + + align:start position:0% +what can what can you think when I if I +say the words conflict and tension what + + align:start position:0% +say the words conflict and tension what + + + align:start position:0% +say the words conflict and tension what +are the what's the the definitions + + align:start position:0% +are the what's the the definitions + + + align:start position:0% +are the what's the the definitions +you're you're more familiar + + align:start position:0% + + + + align:start position:0% + +with anybody heard it in drama or + + align:start position:0% +with anybody heard it in drama or + + + align:start position:0% +with anybody heard it in drama or +writing like the narrative arc there's a + + align:start position:0% +writing like the narrative arc there's a + + + align:start position:0% +writing like the narrative arc there's a +conflict there are two two people who + + align:start position:0% +conflict there are two two people who + + + align:start position:0% +conflict there are two two people who +want the same thing or there's an + + align:start position:0% +want the same thing or there's an + + + align:start position:0% +want the same thing or there's an +internal conflict I've got and that's + + align:start position:0% +internal conflict I've got and that's + + + align:start position:0% +internal conflict I've got and that's +really what I'm thinking of when I'm + + align:start position:0% +really what I'm thinking of when I'm + + + align:start position:0% +really what I'm thinking of when I'm +saying conflict in this case is what is + + align:start position:0% +saying conflict in this case is what is + + + align:start position:0% +saying conflict in this case is what is +the conflict in the player as they're + + align:start position:0% +the conflict in the player as they're + + + align:start position:0% +the conflict in the player as they're +making these decisions what is the what + + align:start position:0% +making these decisions what is the what + + + align:start position:0% +making these decisions what is the what +are the trade-offs they're making Um, do + + align:start position:0% +are the trade-offs they're making Um, do + + + align:start position:0% +are the trade-offs they're making Um, do +I send an army this way or do I send an + + align:start position:0% +I send an army this way or do I send an + + + align:start position:0% +I send an army this way or do I send an +army that way or do I not fight at all? + + align:start position:0% +army that way or do I not fight at all? + + + align:start position:0% +army that way or do I not fight at all? +If that is a really hard decision for + + align:start position:0% +If that is a really hard decision for + + + align:start position:0% +If that is a really hard decision for +the player to make if they can't + + align:start position:0% +the player to make if they can't + + + align:start position:0% +the player to make if they can't +calculate it beforehand, um, if they + + align:start position:0% +calculate it beforehand, um, if they + + + align:start position:0% +calculate it beforehand, um, if they +have enough information to know that one + + align:start position:0% +have enough information to know that one + + + align:start position:0% +have enough information to know that one +may be better than the other, but + + align:start position:0% +may be better than the other, but + + + align:start position:0% +may be better than the other, but +they're not quite sure. That's what + + align:start position:0% +they're not quite sure. That's what + + + align:start position:0% +they're not quite sure. That's what +we're talking about with conflict with + + align:start position:0% +we're talking about with conflict with + + + align:start position:0% +we're talking about with conflict with +what Pablo was playing with us. The the + + align:start position:0% +what Pablo was playing with us. The the + + + align:start position:0% +what Pablo was playing with us. The the +conflict in the individual teams of + + align:start position:0% +conflict in the individual teams of + + + align:start position:0% +conflict in the individual teams of +well, which we know the probabilities, + + align:start position:0% +well, which we know the probabilities, + + + align:start position:0% +well, which we know the probabilities, +we can calculate that, but are we are we + + align:start position:0% +we can calculate that, but are we are we + + + align:start position:0% +we can calculate that, but are we are we +sure? Are we sure it's going to play out + + align:start position:0% +sure? Are we sure it's going to play out + + + align:start position:0% +sure? Are we sure it's going to play out +that way? I really wish you'd used the + + align:start position:0% +that way? I really wish you'd used the + + + align:start position:0% +that way? I really wish you'd used the +cones because I really want to know if + + align:start position:0% +cones because I really want to know if + + + align:start position:0% +cones because I really want to know if +the cone like how often the cone is + + align:start position:0% +the cone like how often the cone is + + + align:start position:0% +the cone like how often the cone is +going to fall on its end. Um, and then + + align:start position:0% +going to fall on its end. Um, and then + + + align:start position:0% +going to fall on its end. Um, and then +tension are ways we can modify that + + align:start position:0% +tension are ways we can modify that + + + align:start position:0% +tension are ways we can modify that +conflict. Maybe there's no conflict + + align:start position:0% +conflict. Maybe there's no conflict + + + align:start position:0% +conflict. Maybe there's no conflict +existing and we need to use tension to + + align:start position:0% +existing and we need to use tension to + + + align:start position:0% +existing and we need to use tension to +create some some conflict. Maybe there's + + align:start position:0% +create some some conflict. Maybe there's + + + align:start position:0% +create some some conflict. Maybe there's +some there's a little bit of conflict + + align:start position:0% +some there's a little bit of conflict + + + align:start position:0% +some there's a little bit of conflict +going on and the tension is going to + + align:start position:0% +going on and the tension is going to + + + align:start position:0% +going on and the tension is going to +amplify that and make it more dramatic. + + align:start position:0% +amplify that and make it more dramatic. + + + align:start position:0% +amplify that and make it more dramatic. +And there's just some some basic things + + align:start position:0% +And there's just some some basic things + + + align:start position:0% +And there's just some some basic things +you can change. Um, and when we talk + + align:start position:0% +you can change. Um, and when we talk + + + align:start position:0% +you can change. Um, and when we talk +about the example games, um, and if you + + align:start position:0% +about the example games, um, and if you + + + align:start position:0% +about the example games, um, and if you +play these example games over the + + align:start position:0% +play these example games over the + + + align:start position:0% +play these example games over the +weekend, think about these terms. Um, if + + align:start position:0% +weekend, think about these terms. Um, if + + + align:start position:0% +weekend, think about these terms. Um, if +I were to change the timing in a game or + + align:start position:0% +I were to change the timing in a game or + + + align:start position:0% +I were to change the timing in a game or +the speed of which you can make + + align:start position:0% +the speed of which you can make + + + align:start position:0% +the speed of which you can make +decisions or the precision that's + + align:start position:0% +decisions or the precision that's + + + align:start position:0% +decisions or the precision that's +required to make those decisions, how + + align:start position:0% +required to make those decisions, how + + + align:start position:0% +required to make those decisions, how +would that increase the conflict? And by + + align:start position:0% +would that increase the conflict? And by + + + align:start position:0% +would that increase the conflict? And by +increasing the conflict there, are the + + align:start position:0% +increasing the conflict there, are the + + + align:start position:0% +increasing the conflict there, are the +choices more interesting? Is the game + + align:start position:0% +choices more interesting? Is the game + + + align:start position:0% +choices more interesting? Is the game +more engaging? Are the game more fun? + + align:start position:0% +more engaging? Are the game more fun? + + + align:start position:0% +more engaging? Are the game more fun? +Limitations are awesome in games. + + align:start position:0% +Limitations are awesome in games. + + + align:start position:0% +Limitations are awesome in games. +Limitations are really how you can can + + align:start position:0% +Limitations are really how you can can + + + align:start position:0% +Limitations are really how you can can +design and control where and what a + + align:start position:0% +design and control where and what a + + + align:start position:0% +design and control where and what a +player can do. So, how many options do + + align:start position:0% +player can do. So, how many options do + + + align:start position:0% +player can do. So, how many options do +you give the player? Do you give them + + align:start position:0% +you give the player? Do you give them + + + align:start position:0% +you give the player? Do you give them +two or three or five or infinite? Um, I + + align:start position:0% +two or three or five or infinite? Um, I + + + align:start position:0% +two or three or five or infinite? Um, I +can tell you right now, having infinite + + align:start position:0% +can tell you right now, having infinite + + + align:start position:0% +can tell you right now, having infinite +choices is really, really difficult, but + + align:start position:0% +choices is really, really difficult, but + + + align:start position:0% +choices is really, really difficult, but +not that interesting. Uh, space, um, + + align:start position:0% +not that interesting. Uh, space, um, + + + align:start position:0% +not that interesting. Uh, space, um, +costs, economics, information, um, fog + + align:start position:0% +costs, economics, information, um, fog + + + align:start position:0% +costs, economics, information, um, fog +of war. We've talked what we've seen in + + align:start position:0% +of war. We've talked what we've seen in + + + align:start position:0% +of war. We've talked what we've seen in +some of these strategy games where you + + align:start position:0% +some of these strategy games where you + + + align:start position:0% +some of these strategy games where you +can only see things that are around + + align:start position:0% +can only see things that are around + + + align:start position:0% +can only see things that are around +where your units are and you can't see + + align:start position:0% +where your units are and you can't see + + + align:start position:0% +where your units are and you can't see +things outside of that. Um, these are + + align:start position:0% +things outside of that. Um, these are + + + align:start position:0% +things outside of that. Um, these are +all methods we use as designers to + + align:start position:0% +all methods we use as designers to + + + align:start position:0% +all methods we use as designers to +create conflict to make those choices + + align:start position:0% +create conflict to make those choices + + + align:start position:0% +create conflict to make those choices +that we're asking our players to make + + align:start position:0% + + + + align:start position:0% + +interesting. So, example games. + + align:start position:0% +interesting. So, example games. + + + align:start position:0% +interesting. So, example games. +Um, what I'd love for you to do, it's + + align:start position:0% +Um, what I'd love for you to do, it's + + + align:start position:0% +Um, what I'd love for you to do, it's +totally optional, but if you're + + align:start position:0% +totally optional, but if you're + + + align:start position:0% +totally optional, but if you're +interested in design, I totally + + align:start position:0% +interested in design, I totally + + + align:start position:0% +interested in design, I totally +recommend it. Over the weekend, play + + align:start position:0% +recommend it. Over the weekend, play + + + align:start position:0% +recommend it. Over the weekend, play +some games. We're going to show the + + align:start position:0% +some games. We're going to show the + + + align:start position:0% +some games. We're going to show the +we're going to talk about these games + + align:start position:0% +we're going to talk about these games + + + align:start position:0% +we're going to talk about these games +and think about these things and these + + align:start position:0% +and think about these things and these + + + align:start position:0% +and think about these things and these +slides are are on stellar. Um, think + + align:start position:0% +slides are are on stellar. Um, think + + + align:start position:0% +slides are are on stellar. Um, think +about the types of decisions you can + + align:start position:0% +about the types of decisions you can + + + align:start position:0% +about the types of decisions you can +make, the timing of the decisions, + + align:start position:0% +make, the timing of the decisions, + + + align:start position:0% +make, the timing of the decisions, +whether the game is single player or + + align:start position:0% +whether the game is single player or + + + align:start position:0% +whether the game is single player or +mult or multiplayer, if there's + + align:start position:0% +mult or multiplayer, if there's + + + align:start position:0% +mult or multiplayer, if there's +competitive or co-op play, um, if + + align:start position:0% +competitive or co-op play, um, if + + + align:start position:0% +competitive or co-op play, um, if +there's teams or alliances, and what + + align:start position:0% +there's teams or alliances, and what + + + align:start position:0% +there's teams or alliances, and what +kind of conflict and tension exists in + + align:start position:0% +kind of conflict and tension exists in + + + align:start position:0% +kind of conflict and tension exists in +the game. Um, all of these are things + + align:start position:0% +the game. Um, all of these are things + + + align:start position:0% +the game. Um, all of these are things +that we're going to be asking you as as + + align:start position:0% +that we're going to be asking you as as + + + align:start position:0% +that we're going to be asking you as as +designers over the semester to decide + + align:start position:0% +designers over the semester to decide + + + align:start position:0% +designers over the semester to decide +on, to design, to craft, to create a + + align:start position:0% +on, to design, to craft, to create a + + + align:start position:0% +on, to design, to craft, to create a +very particular experience that you're + + align:start position:0% +very particular experience that you're + + + align:start position:0% +very particular experience that you're +trying to create. So, Drew is going to + + align:start position:0% +trying to create. So, Drew is going to + + + align:start position:0% +trying to create. So, Drew is going to +kick us off. It's this + + align:start position:0% +kick us off. It's this + + + align:start position:0% +kick us off. It's this +game. Who's played back gammon? Wow. + + align:start position:0% +game. Who's played back gammon? Wow. + + + align:start position:0% +game. Who's played back gammon? Wow. +Really? No one plays back anymore. All + + align:start position:0% +Really? No one plays back anymore. All + + + align:start position:0% +Really? No one plays back anymore. All +right. Back gam is a pretty classic + + align:start position:0% +right. Back gam is a pretty classic + + + align:start position:0% +right. Back gam is a pretty classic +game. It was invented a good oh, 5,000 + + align:start position:0% +game. It was invented a good oh, 5,000 + + + align:start position:0% +game. It was invented a good oh, 5,000 +years ago or so, about the time that we + + align:start position:0% +years ago or so, about the time that we + + + align:start position:0% +years ago or so, about the time that we +learned how to to write. Um, it's got a + + align:start position:0% +learned how to to write. Um, it's got a + + + align:start position:0% +learned how to to write. Um, it's got a +lot of planning. Oddly enough, there's a + + align:start position:0% +lot of planning. Oddly enough, there's a + + + align:start position:0% +lot of planning. Oddly enough, there's a +lot of pro probability and randomness to + + align:start position:0% +lot of pro probability and randomness to + + + align:start position:0% +lot of pro probability and randomness to +it, but you can plan for that randomness + + align:start position:0% +it, but you can plan for that randomness + + + align:start position:0% +it, but you can plan for that randomness +by setting your pieces in the right + + align:start position:0% +by setting your pieces in the right + + + align:start position:0% +by setting your pieces in the right +spots. You can choose different + + align:start position:0% +spots. You can choose different + + + align:start position:0% +spots. You can choose different +strategies. Are you going to be + + align:start position:0% +strategies. Are you going to be + + + align:start position:0% +strategies. Are you going to be +aggressive to take the other person's + + align:start position:0% +aggressive to take the other person's + + + align:start position:0% +aggressive to take the other person's +pieces? Are you going to be defensive + + align:start position:0% +pieces? Are you going to be defensive + + + align:start position:0% +pieces? Are you going to be defensive +and just try to protect yourself? Or are + + align:start position:0% +and just try to protect yourself? Or are + + + align:start position:0% +and just try to protect yourself? Or are +you going to leave some in the + + align:start position:0% +you going to leave some in the + + + align:start position:0% +you going to leave some in the +opponent's backfield so that if you're + + align:start position:0% +opponent's backfield so that if you're + + + align:start position:0% +opponent's backfield so that if you're +losing at the end, you can maybe mess + + align:start position:0% +losing at the end, you can maybe mess + + + align:start position:0% +losing at the end, you can maybe mess +them up somehow? Uh, or when do you + + align:start position:0% +them up somehow? Uh, or when do you + + + align:start position:0% +them up somehow? Uh, or when do you +change from trying to mess them up to + + align:start position:0% +change from trying to mess them up to + + + align:start position:0% +change from trying to mess them up to +shooting for the end goal? There's a + + align:start position:0% +shooting for the end goal? There's a + + + align:start position:0% +shooting for the end goal? There's a +couple different ways to play back + + align:start position:0% +couple different ways to play back + + + align:start position:0% +couple different ways to play back +gammon, oddly enough, and it actually is + + align:start position:0% +gammon, oddly enough, and it actually is + + + align:start position:0% +gammon, oddly enough, and it actually is +a fairly deep game. There's a lot of + + align:start position:0% +a fairly deep game. There's a lot of + + + align:start position:0% +a fairly deep game. There's a lot of +probability involved, but some tactics + + align:start position:0% +probability involved, but some tactics + + + align:start position:0% +probability involved, but some tactics +and some strategy going on in there, + + align:start position:0% +and some strategy going on in there, + + + align:start position:0% +and some strategy going on in there, +too. Um, if you haven't played it and + + align:start position:0% +too. Um, if you haven't played it and + + + align:start position:0% +too. Um, if you haven't played it and +you like board games, it's well worth + + align:start position:0% +you like board games, it's well worth + + + align:start position:0% +you like board games, it's well worth +playing because I think a lot of the + + align:start position:0% +playing because I think a lot of the + + + align:start position:0% +playing because I think a lot of the +things that you're going to see in + + align:start position:0% +things that you're going to see in + + + align:start position:0% +things that you're going to see in +modern board games really owe a lot to + + align:start position:0% +modern board games really owe a lot to + + + align:start position:0% +modern board games really owe a lot to +this game right here, especially when + + align:start position:0% +this game right here, especially when + + + align:start position:0% +this game right here, especially when +you add randomness as a mechanic. Uh, Go + + align:start position:0% +you add randomness as a mechanic. Uh, Go + + + align:start position:0% +you add randomness as a mechanic. Uh, Go +and chess are obviously really, really + + align:start position:0% +and chess are obviously really, really + + + align:start position:0% +and chess are obviously really, really +awesome games, too, but they're a very + + align:start position:0% +awesome games, too, but they're a very + + + align:start position:0% +awesome games, too, but they're a very +different style of game because they + + align:start position:0% +different style of game because they + + + align:start position:0% +different style of game because they +don't have the randomness in there. It's + + align:start position:0% +don't have the randomness in there. It's + + + align:start position:0% +don't have the randomness in there. It's +a very, very different way of thinking + + align:start position:0% +a very, very different way of thinking + + + align:start position:0% +a very, very different way of thinking +about + + align:start position:0% +about + + + align:start position:0% +about +it. This is another one where I think + + align:start position:0% +it. This is another one where I think + + + align:start position:0% +it. This is another one where I think +there's more planning people give it + + align:start position:0% +there's more planning people give it + + + align:start position:0% +there's more planning people give it +credit for. Who's played + + align:start position:0% +credit for. Who's played + + + align:start position:0% +credit for. Who's played +Twister? That's more like it. Okay. So, + + align:start position:0% +Twister? That's more like it. Okay. So, + + + align:start position:0% +Twister? That's more like it. Okay. So, +in Twister, you actually can plan ahead. + + align:start position:0% +in Twister, you actually can plan ahead. + + + align:start position:0% +in Twister, you actually can plan ahead. +You probably don't. But if you played + + align:start position:0% +You probably don't. But if you played + + + align:start position:0% +You probably don't. But if you played +Twister a lot, you might start. You + + align:start position:0% +Twister a lot, you might start. You + + + align:start position:0% +Twister a lot, you might start. You +might realize if I put my right foot + + align:start position:0% +might realize if I put my right foot + + + align:start position:0% +might realize if I put my right foot +there, I'm really screwed if they call + + align:start position:0% +there, I'm really screwed if they call + + + align:start position:0% +there, I'm really screwed if they call +red next time. So, I guess I won't. I'll + + align:start position:0% +red next time. So, I guess I won't. I'll + + + align:start position:0% +red next time. So, I guess I won't. I'll +put it over there. Kind of depends on + + align:start position:0% +put it over there. Kind of depends on + + + align:start position:0% +put it over there. Kind of depends on +how many people are playing. If there's + + align:start position:0% +how many people are playing. If there's + + + align:start position:0% +how many people are playing. If there's +no people playing, you can't do that. + + align:start position:0% +no people playing, you can't do that. + + + align:start position:0% +no people playing, you can't do that. +You should be fast. So, Twister is an + + align:start position:0% +You should be fast. So, Twister is an + + + align:start position:0% +You should be fast. So, Twister is an +interesting game where sometimes you + + align:start position:0% +interesting game where sometimes you + + + align:start position:0% +interesting game where sometimes you +have to make your decision extremely + + align:start position:0% +have to make your decision extremely + + + align:start position:0% +have to make your decision extremely +quickly. Um, are there strategic Is + + align:start position:0% +quickly. Um, are there strategic Is + + + align:start position:0% +quickly. Um, are there strategic Is +there a strategy in Twister? + + align:start position:0% +there a strategy in Twister? + + + align:start position:0% +there a strategy in Twister? +Anyone? I see some nods. What kind What + + align:start position:0% +Anyone? I see some nods. What kind What + + + align:start position:0% +Anyone? I see some nods. What kind What +would you What What decisions would you + + align:start position:0% +would you What What decisions would you + + + align:start position:0% +would you What What decisions would you +make? Um, maybe to go under somebody if + + align:start position:0% +make? Um, maybe to go under somebody if + + + align:start position:0% +make? Um, maybe to go under somebody if +you have to reach in and like lift them + + align:start position:0% +you have to reach in and like lift them + + + align:start position:0% +you have to reach in and like lift them +off the book. All right. Yes. So, + + align:start position:0% +off the book. All right. Yes. So, + + + align:start position:0% +off the book. All right. Yes. So, +there's a strategy to Twister. If you + + align:start position:0% +there's a strategy to Twister. If you + + + align:start position:0% +there's a strategy to Twister. If you +want to play Twister to, you know, to + + align:start position:0% +want to play Twister to, you know, to + + + align:start position:0% +want to play Twister to, you know, to +win. Darn + + align:start position:0% +win. Darn + + + align:start position:0% +win. Darn +it. And, you know, maybe you're thinking + + align:start position:0% +it. And, you know, maybe you're thinking + + + align:start position:0% +it. And, you know, maybe you're thinking +that I've got better balance or maybe + + align:start position:0% +that I've got better balance or maybe + + + align:start position:0% +that I've got better balance or maybe +I'm a little bit bigger than they are. I + + align:start position:0% +I'm a little bit bigger than they are. I + + + align:start position:0% +I'm a little bit bigger than they are. I +bet I could nudge them a little bit. + + align:start position:0% +bet I could nudge them a little bit. + + + align:start position:0% +bet I could nudge them a little bit. +That would work, right? That does work. + + align:start position:0% +That would work, right? That does work. + + + align:start position:0% +That would work, right? That does work. +Or maybe you want to play off in your + + align:start position:0% +Or maybe you want to play off in your + + + align:start position:0% +Or maybe you want to play off in your +own little corner. That works too, + + align:start position:0% +own little corner. That works too, + + + align:start position:0% +own little corner. That works too, +unless no one else lets you do it. Or if + + align:start position:0% +unless no one else lets you do it. Or if + + + align:start position:0% +unless no one else lets you do it. Or if +you get yourself too tangled up, you + + align:start position:0% +you get yourself too tangled up, you + + + align:start position:0% +you get yourself too tangled up, you +can't move even when you're by yourself. + + align:start position:0% +can't move even when you're by yourself. + + + align:start position:0% +can't move even when you're by yourself. +Have you done that or seen that? + + align:start position:0% +Have you done that or seen that? + + + align:start position:0% +Have you done that or seen that? +Someone's off by themselves in the + + align:start position:0% +Someone's off by themselves in the + + + align:start position:0% +Someone's off by themselves in the +Twister and they fall over with no one + + align:start position:0% +Twister and they fall over with no one + + + align:start position:0% +Twister and they fall over with no one +near them. It totally + + align:start position:0% +near them. It totally + + + align:start position:0% +near them. It totally +happens. There's other strategic + + align:start position:0% +happens. There's other strategic + + + align:start position:0% +happens. There's other strategic +decisions for Twister. Are you trying to + + align:start position:0% +decisions for Twister. Are you trying to + + + align:start position:0% +decisions for Twister. Are you trying to +win? Are you trying to stay near someone + + align:start position:0% +win? Are you trying to stay near someone + + + align:start position:0% +win? Are you trying to stay near someone +or away from someone? There are totally + + align:start position:0% +or away from someone? There are totally + + + align:start position:0% +or away from someone? There are totally +other game goals to Twister and they're + + align:start position:0% +other game goals to Twister and they're + + + align:start position:0% +other game goals to Twister and they're +up to the people who are playing it. + + align:start position:0% +up to the people who are playing it. + + + align:start position:0% +up to the people who are playing it. +What is next? Okay, another me. So, this + + align:start position:0% +What is next? Okay, another me. So, this + + + align:start position:0% +What is next? Okay, another me. So, this +is not what anybody thinks of when they + + align:start position:0% +is not what anybody thinks of when they + + + align:start position:0% +is not what anybody thinks of when they +think of strategic game. Um, but I want + + align:start position:0% +think of strategic game. Um, but I want + + + align:start position:0% +think of strategic game. Um, but I want +to point out that decisions come in a + + align:start position:0% +to point out that decisions come in a + + + align:start position:0% +to point out that decisions come in a +lot of different styles. + + align:start position:0% +lot of different styles. + + + align:start position:0% +lot of different styles. +Um, you're not going to ever ruin your + + align:start position:0% +Um, you're not going to ever ruin your + + + align:start position:0% +Um, you're not going to ever ruin your +game by any decisions you make in + + align:start position:0% +game by any decisions you make in + + + align:start position:0% +game by any decisions you make in +Farmville particularly, but it is a game + + align:start position:0% +Farmville particularly, but it is a game + + + align:start position:0% +Farmville particularly, but it is a game +that lets people make a lot of choices + + align:start position:0% +that lets people make a lot of choices + + + align:start position:0% +that lets people make a lot of choices +about what they want to do relatively + + align:start position:0% +about what they want to do relatively + + + align:start position:0% +about what they want to do relatively +freely. + + align:start position:0% +freely. + + + align:start position:0% +freely. +Um, the strategy where strategy and + + align:start position:0% +Um, the strategy where strategy and + + + align:start position:0% +Um, the strategy where strategy and +resource management comes into Farmville + + align:start position:0% +resource management comes into Farmville + + + align:start position:0% +resource management comes into Farmville +is you have a limited number of actions + + align:start position:0% +is you have a limited number of actions + + + align:start position:0% +is you have a limited number of actions +you can take, which means you can only + + align:start position:0% +you can take, which means you can only + + + align:start position:0% +you can take, which means you can only +play the game for so long. Assuming you + + align:start position:0% +play the game for so long. Assuming you + + + align:start position:0% +play the game for so long. Assuming you +do not want to become one of those + + align:start position:0% +do not want to become one of those + + + align:start position:0% +do not want to become one of those +people who spends a big pile of money + + align:start position:0% +people who spends a big pile of money + + + align:start position:0% +people who spends a big pile of money +playing Farmville, which I'm going to + + align:start position:0% +playing Farmville, which I'm going to + + + align:start position:0% +playing Farmville, which I'm going to +assume you are. + + align:start position:0% +assume you are. + + + align:start position:0% +assume you are. +Um, so you need to manage your actions + + align:start position:0% +Um, so you need to manage your actions + + + align:start position:0% +Um, so you need to manage your actions +and think about how many actions you're + + align:start position:0% +and think about how many actions you're + + + align:start position:0% +and think about how many actions you're +taking and think about when you want to + + align:start position:0% +taking and think about when you want to + + + align:start position:0% +taking and think about when you want to +come back to the game. And the way they + + align:start position:0% +come back to the game. And the way they + + + align:start position:0% +come back to the game. And the way they +do that and the way that you can gain + + align:start position:0% +do that and the way that you can gain + + + align:start position:0% +do that and the way that you can gain +that system is by looking at how long it + + align:start position:0% +that system is by looking at how long it + + + align:start position:0% +that system is by looking at how long it +takes things to grow, what you want to + + align:start position:0% +takes things to grow, what you want to + + + align:start position:0% +takes things to grow, what you want to +grow, what you want to make. Farmville + + align:start position:0% +grow, what you want to make. Farmville + + + align:start position:0% +grow, what you want to make. Farmville +is actually at this point kind of + + align:start position:0% +is actually at this point kind of + + + align:start position:0% +is actually at this point kind of +outdated because they've moved to + + align:start position:0% +outdated because they've moved to + + + align:start position:0% +outdated because they've moved to +Farmville, too. Um, but I I did not + + align:start position:0% +Farmville, too. Um, but I I did not + + + align:start position:0% +Farmville, too. Um, but I I did not +actually want to go there and play it to + + align:start position:0% +actually want to go there and play it to + + + align:start position:0% +actually want to go there and play it to +be to have the expertise to tell you + + align:start position:0% +be to have the expertise to tell you + + + align:start position:0% +be to have the expertise to tell you +about it. I I did spend enough time + + align:start position:0% +about it. I I did spend enough time + + + align:start position:0% +about it. I I did spend enough time +playing Farmville to know that there's a + + align:start position:0% +playing Farmville to know that there's a + + + align:start position:0% +playing Farmville to know that there's a +whole lot of there's actually a whole + + align:start position:0% +whole lot of there's actually a whole + + + align:start position:0% +whole lot of there's actually a whole +lot of interesting decisions you get to + + align:start position:0% +lot of interesting decisions you get to + + + align:start position:0% +lot of interesting decisions you get to +make there. Um, and it's not a game + + align:start position:0% +make there. Um, and it's not a game + + + align:start position:0% +make there. Um, and it's not a game +people think of when they think of + + align:start position:0% +people think of when they think of + + + align:start position:0% +people think of when they think of +meaningful decisions because they've + + align:start position:0% +meaningful decisions because they've + + + align:start position:0% +meaningful decisions because they've +heard a whole lot of, "Oh my god, it's + + align:start position:0% +heard a whole lot of, "Oh my god, it's + + + align:start position:0% +heard a whole lot of, "Oh my god, it's +that click game." + + align:start position:0% +that click game." + + + align:start position:0% +that click game." +Um, just because it's a game that + + align:start position:0% +Um, just because it's a game that + + + align:start position:0% +Um, just because it's a game that +doesn't have a lot of deep consequences + + align:start position:0% +doesn't have a lot of deep consequences + + + align:start position:0% +doesn't have a lot of deep consequences +doesn't mean it can't have a lot of deep + + align:start position:0% +doesn't mean it can't have a lot of deep + + + align:start position:0% +doesn't mean it can't have a lot of deep +play. Am I hitting the right button? + + align:start position:0% +play. Am I hitting the right button? + + + align:start position:0% +play. Am I hitting the right button? +Let's find out. Um, so Plants Versus + + align:start position:0% +Let's find out. Um, so Plants Versus + + + align:start position:0% +Let's find out. Um, so Plants Versus +Zombies is uh essentially a really + + align:start position:0% +Zombies is uh essentially a really + + + align:start position:0% +Zombies is uh essentially a really +popular Tower Defense game. And Tower + + align:start position:0% +popular Tower Defense game. And Tower + + + align:start position:0% +popular Tower Defense game. And Tower +Defense was not very popular until + + align:start position:0% +Defense was not very popular until + + + align:start position:0% +Defense was not very popular until +Plants Versus Zombies came out because + + align:start position:0% +Plants Versus Zombies came out because + + + align:start position:0% +Plants Versus Zombies came out because +most people hadn't done it very well or + + align:start position:0% +most people hadn't done it very well or + + + align:start position:0% +most people hadn't done it very well or +presented it very well. Um, but in + + align:start position:0% +presented it very well. Um, but in + + + align:start position:0% +presented it very well. Um, but in +Plants Versus Zombies, you've got tons + + align:start position:0% +Plants Versus Zombies, you've got tons + + + align:start position:0% +Plants Versus Zombies, you've got tons +of choices. Who here has played Plants + + align:start position:0% +of choices. Who here has played Plants + + + align:start position:0% +of choices. Who here has played Plants +Versus Zombies? Let me ask the first + + align:start position:0% +Versus Zombies? Let me ask the first + + + align:start position:0% +Versus Zombies? Let me ask the first +question. Okay. So, yeah, you know what + + align:start position:0% +question. Okay. So, yeah, you know what + + + align:start position:0% +question. Okay. So, yeah, you know what +I'm talking about. + + align:start position:0% +I'm talking about. + + + align:start position:0% +I'm talking about. +Um, they made they got the UI right. + + align:start position:0% +Um, they made they got the UI right. + + + align:start position:0% +Um, they made they got the UI right. +Absolutely. So, it's easy to play. Um, + + align:start position:0% +Absolutely. So, it's easy to play. Um, + + + align:start position:0% +Absolutely. So, it's easy to play. Um, +and every time you go in to play a + + align:start position:0% +and every time you go in to play a + + + align:start position:0% +and every time you go in to play a +level, you get to choose which strategy + + align:start position:0% +level, you get to choose which strategy + + + align:start position:0% +level, you get to choose which strategy +are you going to use. You've got sort of + + align:start position:0% +are you going to use. You've got sort of + + + align:start position:0% +are you going to use. You've got sort of +the long-term strategy choice for each + + align:start position:0% +the long-term strategy choice for each + + + align:start position:0% +the long-term strategy choice for each +level where you get to choose which + + align:start position:0% +level where you get to choose which + + + align:start position:0% +level where you get to choose which +creatures you're taking or which plants + + align:start position:0% +creatures you're taking or which plants + + + align:start position:0% +creatures you're taking or which plants +you're taking. And you can go back and + + align:start position:0% +you're taking. And you can go back and + + + align:start position:0% +you're taking. And you can go back and +play each level with a completely + + align:start position:0% +play each level with a completely + + + align:start position:0% +play each level with a completely +different set of plants and still + + align:start position:0% +different set of plants and still + + + align:start position:0% +different set of plants and still +succeed or fail at it. Um, in my case, + + align:start position:0% +succeed or fail at it. Um, in my case, + + + align:start position:0% +succeed or fail at it. Um, in my case, +it's often more + + align:start position:0% +it's often more + + + align:start position:0% +it's often more +failing. Um, they give you just enough + + align:start position:0% +failing. Um, they give you just enough + + + align:start position:0% +failing. Um, they give you just enough +information so you can think about what + + align:start position:0% +information so you can think about what + + + align:start position:0% +information so you can think about what +you're going to bring. + + align:start position:0% +you're going to bring. + + + align:start position:0% +you're going to bring. +Um, you can see what's coming in. You + + align:start position:0% +Um, you can see what's coming in. You + + + align:start position:0% +Um, you can see what's coming in. You +don't know how many of those they're + + align:start position:0% +don't know how many of those they're + + + align:start position:0% +don't know how many of those they're +going to come. You don't know when + + align:start position:0% +going to come. You don't know when + + + align:start position:0% +going to come. You don't know when +they're going to come. So, you have to + + align:start position:0% +they're going to come. So, you have to + + + align:start position:0% +they're going to come. So, you have to +both plan for, oh, I know there's going + + align:start position:0% +both plan for, oh, I know there's going + + + align:start position:0% +both plan for, oh, I know there's going +to be a zombini, but I don't know how + + align:start position:0% +to be a zombini, but I don't know how + + + align:start position:0% +to be a zombini, but I don't know how +much of them it is. How much resources + + align:start position:0% +much of them it is. How much resources + + + align:start position:0% +much of them it is. How much resources +do I need to devote to worrying about + + align:start position:0% +do I need to devote to worrying about + + + align:start position:0% +do I need to devote to worrying about +the + + align:start position:0% + + + + align:start position:0% + +zombie? I'm not getting that right at + + align:start position:0% +zombie? I'm not getting that right at + + + align:start position:0% +zombie? I'm not getting that right at +all, am I? Um, how many how much + + align:start position:0% +all, am I? Um, how many how much + + + align:start position:0% +all, am I? Um, how many how much +resources do I have to worry about + + align:start position:0% +resources do I have to worry about + + + align:start position:0% +resources do I have to worry about +devoting to that versus all the other + + align:start position:0% +devoting to that versus all the other + + + align:start position:0% +devoting to that versus all the other +threats I've got coming in? + + align:start position:0% +threats I've got coming in? + + + align:start position:0% +threats I've got coming in? +So, now I have to admit something + + align:start position:0% +So, now I have to admit something + + + align:start position:0% +So, now I have to admit something +terrible. Um, my daughters play this + + align:start position:0% +terrible. Um, my daughters play this + + + align:start position:0% +terrible. Um, my daughters play this +game and I have watched them play this + + align:start position:0% +game and I have watched them play this + + + align:start position:0% +game and I have watched them play this +game, but I haven't actually played this + + align:start position:0% +game, but I haven't actually played this + + + align:start position:0% +game, but I haven't actually played this +game. And I was going to play it tonight + + align:start position:0% +game. And I was going to play it tonight + + + align:start position:0% +game. And I was going to play it tonight +and last night so I could talk about it + + align:start position:0% +and last night so I could talk about it + + + align:start position:0% +and last night so I could talk about it +and then my daughters hid my iPad on me. + + align:start position:0% +and then my daughters hid my iPad on me. + + + align:start position:0% +and then my daughters hid my iPad on me. +It's very hard to download a game when + + align:start position:0% +It's very hard to download a game when + + + align:start position:0% +It's very hard to download a game when +you don't have the device to download it + + align:start position:0% +you don't have the device to download it + + + align:start position:0% +you don't have the device to download it +onto. So, has anybody else played this + + align:start position:0% +onto. So, has anybody else played this + + + align:start position:0% +onto. So, has anybody else played this +game? Okay, a few people have. So, um, + + align:start position:0% +game? Okay, a few people have. So, um, + + + align:start position:0% +game? Okay, a few people have. So, um, +your goal, of course, your goal in this + + align:start position:0% +your goal, of course, your goal in this + + + align:start position:0% +your goal, of course, your goal in this +game is to you're a virus. You would + + align:start position:0% +game is to you're a virus. You would + + + align:start position:0% +game is to you're a virus. You would +like to evolve and hopefully take out + + align:start position:0% +like to evolve and hopefully take out + + + align:start position:0% +like to evolve and hopefully take out +all of humanity. Um, and as you're + + align:start position:0% +all of humanity. Um, and as you're + + + align:start position:0% +all of humanity. Um, and as you're +playing the game as the player guiding + + align:start position:0% +playing the game as the player guiding + + + align:start position:0% +playing the game as the player guiding +the virus's development, you get to make + + align:start position:0% +the virus's development, you get to make + + + align:start position:0% +the virus's development, you get to make +a lot of choices. Um, how lethal is it? + + align:start position:0% +a lot of choices. Um, how lethal is it? + + + align:start position:0% +a lot of choices. Um, how lethal is it? +What kind of symptoms do you have? How + + align:start position:0% +What kind of symptoms do you have? How + + + align:start position:0% +What kind of symptoms do you have? How +easy is it to spread? Uh my daughters + + align:start position:0% +easy is it to spread? Uh my daughters + + + align:start position:0% +easy is it to spread? Uh my daughters +are working on the infect the whole + + align:start position:0% +are working on the infect the whole + + + align:start position:0% +are working on the infect the whole +planet with a completely symptomless + + align:start position:0% +planet with a completely symptomless + + + align:start position:0% +planet with a completely symptomless +disease tactic and then evolve quickly + + align:start position:0% +disease tactic and then evolve quickly + + + align:start position:0% +disease tactic and then evolve quickly +up to lethality and take everybody out. + + align:start position:0% +up to lethality and take everybody out. + + + align:start position:0% +up to lethality and take everybody out. +Um they haven't succeeded at this. It + + align:start position:0% +Um they haven't succeeded at this. It + + + align:start position:0% +Um they haven't succeeded at this. It +sounds like the perfect strategy, but + + align:start position:0% +sounds like the perfect strategy, but + + + align:start position:0% +sounds like the perfect strategy, but +they haven't succeeded at this because + + align:start position:0% +they haven't succeeded at this because + + + align:start position:0% +they haven't succeeded at this because +you kind of need symptoms to cause + + align:start position:0% +you kind of need symptoms to cause + + + align:start position:0% +you kind of need symptoms to cause +damage and they can't evolve the + + align:start position:0% +damage and they can't evolve the + + + align:start position:0% +damage and they can't evolve the +symptoms fast enough once they've gotten + + align:start position:0% +symptoms fast enough once they've gotten + + + align:start position:0% +symptoms fast enough once they've gotten +everyone infected and they're going from + + align:start position:0% +everyone infected and they're going from + + + align:start position:0% +everyone infected and they're going from +completely harmless to deadly. They + + align:start position:0% +completely harmless to deadly. They + + + align:start position:0% +completely harmless to deadly. They +can't manage to evolve it fast enough. + + align:start position:0% +can't manage to evolve it fast enough. + + + align:start position:0% +can't manage to evolve it fast enough. +Um, so it's an it's got a lot of + + align:start position:0% +Um, so it's an it's got a lot of + + + align:start position:0% +Um, so it's an it's got a lot of +interesting play there where you've got + + align:start position:0% +interesting play there where you've got + + + align:start position:0% +interesting play there where you've got +a lot of different tactics. I think they + + align:start position:0% +a lot of different tactics. I think they + + + align:start position:0% +a lot of different tactics. I think they +can get it someday, but they haven't + + align:start position:0% +can get it someday, but they haven't + + + align:start position:0% +can get it someday, but they haven't +yet. They'll need to try a different + + align:start position:0% +yet. They'll need to try a different + + + align:start position:0% +yet. They'll need to try a different +tactic. + + align:start position:0% +tactic. + + + align:start position:0% +tactic. +Um, and finally, a game I have played an + + align:start position:0% +Um, and finally, a game I have played an + + + align:start position:0% +Um, and finally, a game I have played an +awful lot of is Pandemic. Who here has + + align:start position:0% +awful lot of is Pandemic. Who here has + + + align:start position:0% +awful lot of is Pandemic. Who here has +played Pandemic? + + align:start position:0% +played Pandemic? + + + align:start position:0% +played Pandemic? +Okay. Um, so what's the main what is + + align:start position:0% +Okay. Um, so what's the main what is + + + align:start position:0% +Okay. Um, so what's the main what is +what is the main tactic and resource you + + align:start position:0% +what is the main tactic and resource you + + + align:start position:0% +what is the main tactic and resource you +have in this game if you played it? + + align:start position:0% + + + + align:start position:0% + +Turns. turns. Oh, time. Time. Yeah. The + + align:start position:0% +Turns. turns. Oh, time. Time. Yeah. The + + + align:start position:0% +Turns. turns. Oh, time. Time. Yeah. The +thing that in a lot of ways in this + + align:start position:0% +thing that in a lot of ways in this + + + align:start position:0% +thing that in a lot of ways in this +game, what you're playing against is + + align:start position:0% +game, what you're playing against is + + + align:start position:0% +game, what you're playing against is +time because when you run out of the + + align:start position:0% +time because when you run out of the + + + align:start position:0% +time because when you run out of the +deck, if you haven't managed to clear + + align:start position:0% +deck, if you haven't managed to clear + + + align:start position:0% +deck, if you haven't managed to clear +things, the game is over. Um, and the + + align:start position:0% +things, the game is over. Um, and the + + + align:start position:0% +things, the game is over. Um, and the +resource you've got is and the choices + + align:start position:0% +resource you've got is and the choices + + + align:start position:0% +resource you've got is and the choices +you got is where people are going and + + align:start position:0% +you got is where people are going and + + + align:start position:0% +you got is where people are going and +which area they're fighting. Um, this is + + align:start position:0% +which area they're fighting. Um, this is + + + align:start position:0% +which area they're fighting. Um, this is +a game, the overall plan of the game, of + + align:start position:0% +a game, the overall plan of the game, of + + + align:start position:0% +a game, the overall plan of the game, of +course, + + align:start position:0% +course, + + + align:start position:0% +course, +is there are four epidemics raging. + + align:start position:0% +is there are four epidemics raging. + + + align:start position:0% +is there are four epidemics raging. +You're the CDC. you need to find cures + + align:start position:0% +You're the CDC. you need to find cures + + + align:start position:0% +You're the CDC. you need to find cures +for all the all the plagues before + + align:start position:0% +for all the all the plagues before + + + align:start position:0% +for all the all the plagues before +um before they take out the rest of + + align:start position:0% +um before they take out the rest of + + + align:start position:0% +um before they take out the rest of +humanity. And so you have to balance + + align:start position:0% +humanity. And so you have to balance + + + align:start position:0% +humanity. And so you have to balance +both your long-term strategy of finding + + align:start position:0% +both your long-term strategy of finding + + + align:start position:0% +both your long-term strategy of finding +a cure for each of the diseases with the + + align:start position:0% +a cure for each of the diseases with the + + + align:start position:0% +a cure for each of the diseases with the +short-term strategy of keeping the + + align:start position:0% +short-term strategy of keeping the + + + align:start position:0% +short-term strategy of keeping the +disease diseases under control so that + + align:start position:0% +disease diseases under control so that + + + align:start position:0% +disease diseases under control so that +you don't end up with everything being + + align:start position:0% +you don't end up with everything being + + + align:start position:0% +you don't end up with everything being +destroyed. + + align:start position:0% + + + + align:start position:0% + +Thank all that much speaking. I could + + align:start position:0% +Thank all that much speaking. I could + + + align:start position:0% +Thank all that much speaking. I could +have played + + align:start position:0% +have played + + + align:start position:0% +have played +uh who's played Dominion. Okay. Pretty + + align:start position:0% +uh who's played Dominion. Okay. Pretty + + + align:start position:0% +uh who's played Dominion. Okay. Pretty +popular. I certainly recommend as it as + + align:start position:0% +popular. I certainly recommend as it as + + + align:start position:0% +popular. I certainly recommend as it as +as a good introduction to the basic idea + + align:start position:0% +as a good introduction to the basic idea + + + align:start position:0% +as a good introduction to the basic idea +of deck building games. Uh actually I + + align:start position:0% +of deck building games. Uh actually I + + + align:start position:0% +of deck building games. Uh actually I +just saw a question. How many people + + align:start position:0% +just saw a question. How many people + + + align:start position:0% +just saw a question. How many people +have played like Magic, Yu-Gi-Oh, + + align:start position:0% +have played like Magic, Yu-Gi-Oh, + + + align:start position:0% +have played like Magic, Yu-Gi-Oh, +Pokemon card game? Okay. All right. A + + align:start position:0% +Pokemon card game? Okay. All right. A + + + align:start position:0% +Pokemon card game? Okay. All right. A +lot of that. So, you know, in many of + + align:start position:0% +lot of that. So, you know, in many of + + + align:start position:0% +lot of that. So, you know, in many of +those games and in Dominion, a lot of + + align:start position:0% +those games and in Dominion, a lot of + + + align:start position:0% +those games and in Dominion, a lot of +the fun is just sort of like building + + align:start position:0% +the fun is just sort of like building + + + align:start position:0% +the fun is just sort of like building +your own machine, your own little + + align:start position:0% +your own machine, your own little + + + align:start position:0% +your own machine, your own little +engine, uh, that is going to execute out + + align:start position:0% +engine, uh, that is going to execute out + + + align:start position:0% +engine, uh, that is going to execute out +your strategy. Now, this your engine + + align:start position:0% +your strategy. Now, this your engine + + + align:start position:0% +your strategy. Now, this your engine +happens to be a deck of cards. It gets + + align:start position:0% +happens to be a deck of cards. It gets + + + align:start position:0% +happens to be a deck of cards. It gets +shuffled up, so it's in some sort of + + align:start position:0% +shuffled up, so it's in some sort of + + + align:start position:0% +shuffled up, so it's in some sort of +random order, but you get to choose what + + align:start position:0% +random order, but you get to choose what + + + align:start position:0% +random order, but you get to choose what +cards go in there. Um, in a collectible + + align:start position:0% +cards go in there. Um, in a collectible + + + align:start position:0% +cards go in there. Um, in a collectible +card game like Magic the Gathering, you + + align:start position:0% +card game like Magic the Gathering, you + + + align:start position:0% +card game like Magic the Gathering, you +are buying those cards and then, you + + align:start position:0% +are buying those cards and then, you + + + align:start position:0% +are buying those cards and then, you +know, assembling the card or there's a + + align:start position:0% +know, assembling the card or there's a + + + align:start position:0% +know, assembling the card or there's a +draft mechanic. In a game like Dominion, + + align:start position:0% +draft mechanic. In a game like Dominion, + + + align:start position:0% +draft mechanic. In a game like Dominion, +uh there there is a way where you buy + + align:start position:0% +uh there there is a way where you buy + + + align:start position:0% +uh there there is a way where you buy +more cards while you're playing the + + align:start position:0% +more cards while you're playing the + + + align:start position:0% +more cards while you're playing the +game. But in the end, what it all comes + + align:start position:0% +game. But in the end, what it all comes + + + align:start position:0% +game. But in the end, what it all comes +down to is buy as you play this game, + + align:start position:0% +down to is buy as you play this game, + + + align:start position:0% +down to is buy as you play this game, +you get cards that go into your deck + + align:start position:0% +you get cards that go into your deck + + + align:start position:0% +you get cards that go into your deck +that are going to get end up being + + align:start position:0% +that are going to get end up being + + + align:start position:0% +that are going to get end up being +shuffled in your deck. And at some + + align:start position:0% +shuffled in your deck. And at some + + + align:start position:0% +shuffled in your deck. And at some +random time in the future, it's going to + + align:start position:0% +random time in the future, it's going to + + + align:start position:0% +random time in the future, it's going to +get played out. And so the cards that + + align:start position:0% +get played out. And so the cards that + + + align:start position:0% +get played out. And so the cards that +you choose to put into your deck turns + + align:start position:0% +you choose to put into your deck turns + + + align:start position:0% +you choose to put into your deck turns +out to be uh your main means of + + align:start position:0% +out to be uh your main means of + + + align:start position:0% +out to be uh your main means of +motivating you towards a certain + + align:start position:0% +motivating you towards a certain + + + align:start position:0% +motivating you towards a certain +strategy. Uh there are a range of + + align:start position:0% +strategy. Uh there are a range of + + + align:start position:0% +strategy. Uh there are a range of +different ways to play this game. uh and + + align:start position:0% +different ways to play this game. uh and + + + align:start position:0% +different ways to play this game. uh and +different possible success uh criteria. + + align:start position:0% +different possible success uh criteria. + + + align:start position:0% +different possible success uh criteria. +But in the end um but and and the really + + align:start position:0% +But in the end um but and and the really + + + align:start position:0% +But in the end um but and and the really +interesting thing about the Dominion + + align:start position:0% +interesting thing about the Dominion + + + align:start position:0% +interesting thing about the Dominion +deck is like I think you get something + + align:start position:0% +deck is like I think you get something + + + align:start position:0% +deck is like I think you get something +like 20 + + align:start position:0% +like 20 + + + align:start position:0% +like 20 +over over 20 different kinds of cards uh + + align:start position:0% +over over 20 different kinds of cards uh + + + align:start position:0% +over over 20 different kinds of cards uh +in uh in a box of dominion, but you only + + align:start position:0% +in uh in a box of dominion, but you only + + + align:start position:0% +in uh in a box of dominion, but you only +play with 10 of them. 10 plus the plus + + align:start position:0% +play with 10 of them. 10 plus the plus + + + align:start position:0% +play with 10 of them. 10 plus the plus +plus plus victory points. So uh so every + + align:start position:0% +plus plus victory points. So uh so every + + + align:start position:0% +plus plus victory points. So uh so every +time you play the game is uh the the + + align:start position:0% +time you play the game is uh the the + + + align:start position:0% +time you play the game is uh the the +strategy starts by just seeing what are + + align:start position:0% +strategy starts by just seeing what are + + + align:start position:0% +strategy starts by just seeing what are +the 10 cards I've got in front of me uh + + align:start position:0% +the 10 cards I've got in front of me uh + + + align:start position:0% +the 10 cards I've got in front of me uh +for this session of play and then you + + align:start position:0% +for this session of play and then you + + + align:start position:0% +for this session of play and then you +choose out of these 10 cards what are + + align:start position:0% +choose out of these 10 cards what are + + + align:start position:0% +choose out of these 10 cards what are +the cards that I'm going to select out + + align:start position:0% +the cards that I'm going to select out + + + align:start position:0% +the cards that I'm going to select out +of what proportion in order to build + + align:start position:0% +of what proportion in order to build + + + align:start position:0% +of what proportion in order to build +this engine that's going to motivate me + + align:start position:0% +this engine that's going to motivate me + + + align:start position:0% +this engine that's going to motivate me +towards victory. So interesting game I + + align:start position:0% +towards victory. So interesting game I + + + align:start position:0% +towards victory. So interesting game I +would strongly recommend it if you know + + align:start position:0% +would strongly recommend it if you know + + + align:start position:0% +would strongly recommend it if you know +someone who's got a copy of this game uh + + align:start position:0% +someone who's got a copy of this game uh + + + align:start position:0% +someone who's got a copy of this game uh +or any of the expansions. They're all + + align:start position:0% +or any of the expansions. They're all + + + align:start position:0% +or any of the expansions. They're all +interchangeable. Oh, + + align:start position:0% + + + + align:start position:0% + +great. Drop seven. Uh, mostly played on + + align:start position:0% +great. Drop seven. Uh, mostly played on + + + align:start position:0% +great. Drop seven. Uh, mostly played on +mobile, although I think there is also a + + align:start position:0% +mobile, although I think there is also a + + + align:start position:0% +mobile, although I think there is also a +browser version of this game. How many + + align:start position:0% +browser version of this game. How many + + + align:start position:0% +browser version of this game. How many +of you played this? Anyone? Yeah, + + align:start position:0% +of you played this? Anyone? Yeah, + + + align:start position:0% +of you played this? Anyone? Yeah, +perfect for a tea ride. Uh, uh, I I I + + align:start position:0% +perfect for a tea ride. Uh, uh, I I I + + + align:start position:0% +perfect for a tea ride. Uh, uh, I I I +find you can you can finish a session on + + align:start position:0% +find you can you can finish a session on + + + align:start position:0% +find you can you can finish a session on +a single trip on the tea. Um, the idea + + align:start position:0% +a single trip on the tea. Um, the idea + + + align:start position:0% +a single trip on the tea. Um, the idea +is that you're just dropping one number + + align:start position:0% +is that you're just dropping one number + + + align:start position:0% +is that you're just dropping one number +from the top of the screen, you know, + + align:start position:0% +from the top of the screen, you know, + + + align:start position:0% +from the top of the screen, you know, +and that number ranges anywhere between + + align:start position:0% +and that number ranges anywhere between + + + align:start position:0% +and that number ranges anywhere between +1 to seven. And if you manage to make a + + align:start position:0% +1 to seven. And if you manage to make a + + + align:start position:0% +1 to seven. And if you manage to make a +row of of numbers that uh add up to the + + align:start position:0% +row of of numbers that uh add up to the + + + align:start position:0% +row of of numbers that uh add up to the +uh to the num let's say I have a row of + + align:start position:0% +uh to the num let's say I have a row of + + + align:start position:0% +uh to the num let's say I have a row of +sixes and I have six sixes in a row. + + align:start position:0% +sixes and I have six sixes in a row. + + + align:start position:0% +sixes and I have six sixes in a row. +Then all of those sixes are going to + + align:start position:0% +Then all of those sixes are going to + + + align:start position:0% +Then all of those sixes are going to +disappear and it's going to also clear + + align:start position:0% +disappear and it's going to also clear + + + align:start position:0% +disappear and it's going to also clear +out some of those gray circles where you + + align:start position:0% +out some of those gray circles where you + + + align:start position:0% +out some of those gray circles where you +don't know the numbers yet. That's going + + align:start position:0% +don't know the numbers yet. That's going + + + align:start position:0% +don't know the numbers yet. That's going +to reveal the numbers behind these gray + + align:start position:0% +to reveal the numbers behind these gray + + + align:start position:0% +to reveal the numbers behind these gray +gray tiles. You can think of them as + + align:start position:0% +gray tiles. You can think of them as + + + align:start position:0% +gray tiles. You can think of them as +tiles that will turn upside down. So + + align:start position:0% +tiles that will turn upside down. So + + + align:start position:0% +tiles that will turn upside down. So +what you really really want to make are + + align:start position:0% +what you really really want to make are + + + align:start position:0% +what you really really want to make are +chains. you know chains of where if I + + align:start position:0% +chains. you know chains of where if I + + + align:start position:0% +chains. you know chains of where if I +have a six and then it if I have a six + + align:start position:0% +have a six and then it if I have a six + + + align:start position:0% +have a six and then it if I have a six +five four three two one then what h then + + align:start position:0% +five four three two one then what h then + + + align:start position:0% +five four three two one then what h then +what happens that that six is going to + + align:start position:0% +what happens that that six is going to + + + align:start position:0% +what happens that that six is going to +burst then that five is going to burst + + align:start position:0% +burst then that five is going to burst + + + align:start position:0% +burst then that five is going to burst +and at four is going to burst and three + + align:start position:0% +and at four is going to burst and three + + + align:start position:0% +and at four is going to burst and three +and so on and so forth it's set of these + + align:start position:0% +and so on and so forth it's set of these + + + align:start position:0% +and so on and so forth it's set of these +massive chains and basically you're just + + align:start position:0% +massive chains and basically you're just + + + align:start position:0% +massive chains and basically you're just +deciding how you're going to place this + + align:start position:0% +deciding how you're going to place this + + + align:start position:0% +deciding how you're going to place this +if you've played a game like Puyo Puyo + + align:start position:0% +if you've played a game like Puyo Puyo + + + align:start position:0% +if you've played a game like Puyo Puyo +uh I'm trying to think certain kinds of + + align:start position:0% +uh I'm trying to think certain kinds of + + + align:start position:0% +uh I'm trying to think certain kinds of +match three games like like BJ old you + + align:start position:0% +match three games like like BJ old you + + + align:start position:0% +match three games like like BJ old you +you'll get this sort of chain reaction + + align:start position:0% +you'll get this sort of chain reaction + + + align:start position:0% +you'll get this sort of chain reaction +uh uh feeling And some games more than + + align:start position:0% +uh uh feeling And some games more than + + + align:start position:0% +uh uh feeling And some games more than +others encourage you to sort of set up + + align:start position:0% +others encourage you to sort of set up + + + align:start position:0% +others encourage you to sort of set up +these chains uh before you sort of drop + + align:start position:0% +these chains uh before you sort of drop + + + align:start position:0% +these chains uh before you sort of drop +the the the triggering piece. Drop 7 is + + align:start position:0% +the the the triggering piece. Drop 7 is + + + align:start position:0% +the the the triggering piece. Drop 7 is +very much about that. Um so um I believe + + align:start position:0% +very much about that. Um so um I believe + + + align:start position:0% +very much about that. Um so um I believe +if you if you can find it on um if you + + align:start position:0% +if you if you can find it on um if you + + + align:start position:0% +if you if you can find it on um if you +can find it on on a browser, it should + + align:start position:0% +can find it on on a browser, it should + + + align:start position:0% +can find it on on a browser, it should +be free. I'm not so sure whether the + + align:start position:0% +be free. I'm not so sure whether the + + + align:start position:0% +be free. I'm not so sure whether the +down the iOS versions are free. Yeah. + + align:start position:0% +down the iOS versions are free. Yeah. + + + align:start position:0% +down the iOS versions are free. Yeah. +Yeah. Great. Okay. + + align:start position:0% +Yeah. Great. Okay. + + + align:start position:0% +Yeah. Great. Okay. +Um I keep forgetting the computer's on + + align:start position:0% +Um I keep forgetting the computer's on + + + align:start position:0% +Um I keep forgetting the computer's on +this side. The Starcraft 2 visual novel. + + align:start position:0% + + + + align:start position:0% + +I'm No, no, it's it's it's still in + + align:start position:0% +I'm No, no, it's it's it's still in + + + align:start position:0% +I'm No, no, it's it's it's still in +development. Um I'm full disclosure, I'm + + align:start position:0% +development. Um I'm full disclosure, I'm + + + align:start position:0% +development. Um I'm full disclosure, I'm +a Kickstarter backer of of this game. As + + align:start position:0% +a Kickstarter backer of of this game. As + + + align:start position:0% +a Kickstarter backer of of this game. As +as I've been mentioned many many times, + + align:start position:0% +as I've been mentioned many many times, + + + align:start position:0% +as I've been mentioned many many times, +I am a Starcraft 2 player and um but I + + align:start position:0% +I am a Starcraft 2 player and um but I + + + align:start position:0% +I am a Starcraft 2 player and um but I +am not encouraging you go to go and + + align:start position:0% +am not encouraging you go to go and + + + align:start position:0% +am not encouraging you go to go and +learn that over the weekend because + + align:start position:0% +learn that over the weekend because + + + align:start position:0% +learn that over the weekend because +Starcraft 2 is more of a lifestyle kind + + align:start position:0% +Starcraft 2 is more of a lifestyle kind + + + align:start position:0% +Starcraft 2 is more of a lifestyle kind +of thing. + + align:start position:0% + + + + align:start position:0% + +Um, but if you just kind of want to see + + align:start position:0% +Um, but if you just kind of want to see + + + align:start position:0% +Um, but if you just kind of want to see +what the what the strategy is about, + + align:start position:0% +what the what the strategy is about, + + + align:start position:0% +what the what the strategy is about, +this is an interesting game where um the + + align:start position:0% +this is an interesting game where um the + + + align:start position:0% +this is an interesting game where um the +the if you've ever played a visual + + align:start position:0% +the if you've ever played a visual + + + align:start position:0% +the if you've ever played a visual +novel, they're kind of like choose your + + align:start position:0% +novel, they're kind of like choose your + + + align:start position:0% +novel, they're kind of like choose your +own adventure um in digital form. Uh, + + align:start position:0% +own adventure um in digital form. Uh, + + + align:start position:0% +own adventure um in digital form. Uh, +and they're usually very strong + + align:start position:0% +and they're usually very strong + + + align:start position:0% +and they're usually very strong +narrative and character driven games. + + align:start position:0% +narrative and character driven games. + + + align:start position:0% +narrative and character driven games. +You play a um a teenager who's moved to + + align:start position:0% +You play a um a teenager who's moved to + + + align:start position:0% +You play a um a teenager who's moved to +Korea in the hope to start his uh his or + + align:start position:0% +Korea in the hope to start his uh his or + + + align:start position:0% +Korea in the hope to start his uh his or +her pro gaming career. and um you go + + align:start position:0% +her pro gaming career. and um you go + + + align:start position:0% +her pro gaming career. and um you go +into a a land center and you play random + + align:start position:0% +into a a land center and you play random + + + align:start position:0% +into a a land center and you play random +games against people, but only these are + + align:start position:0% +games against people, but only these are + + + align:start position:0% +games against people, but only these are +the kinds of decisions you get to make. + + align:start position:0% +the kinds of decisions you get to make. + + + align:start position:0% +the kinds of decisions you get to make. +Which strategy are you going to go for? + + align:start position:0% +Which strategy are you going to go for? + + + align:start position:0% +Which strategy are you going to go for? +I actually find uh this to be a really + + align:start position:0% +I actually find uh this to be a really + + + align:start position:0% +I actually find uh this to be a really +really good way of conveying kind of the + + align:start position:0% +really good way of conveying kind of the + + + align:start position:0% +really good way of conveying kind of the +macrolevel decisions, the really really + + align:start position:0% +macrolevel decisions, the really really + + + align:start position:0% +macrolevel decisions, the really really +high level long-term strategic decisions + + align:start position:0% +high level long-term strategic decisions + + + align:start position:0% +high level long-term strategic decisions +that you're going to make because you're + + align:start position:0% +that you're going to make because you're + + + align:start position:0% +that you're going to make because you're +not actually playing Starcraft. you're + + align:start position:0% +not actually playing Starcraft. you're + + + align:start position:0% +not actually playing Starcraft. you're +choosing between one to three choices uh + + align:start position:0% +choosing between one to three choices uh + + + align:start position:0% +choosing between one to three choices uh +two or three choices uh and then it + + align:start position:0% +two or three choices uh and then it + + + align:start position:0% +two or three choices uh and then it +plays out. Um but it gives you a good + + align:start position:0% +plays out. Um but it gives you a good + + + align:start position:0% +plays out. Um but it gives you a good +idea of the kind of highlevel decision + + align:start position:0% +idea of the kind of highlevel decision + + + align:start position:0% +idea of the kind of highlevel decision +making whereas most people see someone + + align:start position:0% +making whereas most people see someone + + + align:start position:0% +making whereas most people see someone +play Starcraft it's + + align:start position:0% +play Starcraft it's + + + align:start position:0% +play Starcraft it's +like and they're not you're not seeing + + align:start position:0% +like and they're not you're not seeing + + + align:start position:0% +like and they're not you're not seeing +that long-term strategy. So, um, we do + + align:start position:0% +that long-term strategy. So, um, we do + + + align:start position:0% +that long-term strategy. So, um, we do +have a, uh, let's play up and the URL is + + align:start position:0% +have a, uh, let's play up and the URL is + + + align:start position:0% +have a, uh, let's play up and the URL is +there, but if you just Google MIT Game + + align:start position:0% +there, but if you just Google MIT Game + + + align:start position:0% +there, but if you just Google MIT Game +Lab Starcraft 2 visual novel, you'll + + align:start position:0% +Lab Starcraft 2 visual novel, you'll + + + align:start position:0% +Lab Starcraft 2 visual novel, you'll +you'll see the YouTube video and get an + + align:start position:0% +you'll see the YouTube video and get an + + + align:start position:0% +you'll see the YouTube video and get an +idea of that because I'm not so sure if + + align:start position:0% +idea of that because I'm not so sure if + + + align:start position:0% +idea of that because I'm not so sure if +you can still download the demo, but the + + align:start position:0% +you can still download the demo, but the + + + align:start position:0% +you can still download the demo, but the +demo does have uh, some of these + + align:start position:0% + + + + align:start position:0% + +features. All right, so uh, my games um + + align:start position:0% +features. All right, so uh, my games um + + + align:start position:0% +features. All right, so uh, my games um +that I chose. What's up? Oh, thank you. + + align:start position:0% +that I chose. What's up? Oh, thank you. + + + align:start position:0% +that I chose. What's up? Oh, thank you. +Cool. So, this one I really like um as + + align:start position:0% +Cool. So, this one I really like um as + + + align:start position:0% +Cool. So, this one I really like um as +an example. It looks awful on the + + align:start position:0% +an example. It looks awful on the + + + align:start position:0% +an example. It looks awful on the +screen, though. So, I really like this + + align:start position:0% +screen, though. So, I really like this + + + align:start position:0% +screen, though. So, I really like this +one as an example because it has not yet + + align:start position:0% +one as an example because it has not yet + + + align:start position:0% +one as an example because it has not yet +been published. On their website, they + + align:start position:0% +been published. On their website, they + + + align:start position:0% +been published. On their website, they +have their alpha build. And if you were + + align:start position:0% +have their alpha build. And if you were + + + align:start position:0% +have their alpha build. And if you were +to um buy their game, what you would see + + align:start position:0% +to um buy their game, what you would see + + + align:start position:0% +to um buy their game, what you would see +is the beta build and then later on when + + align:start position:0% +is the beta build and then later on when + + + align:start position:0% +is the beta build and then later on when +it actually does publish, um you can + + align:start position:0% +it actually does publish, um you can + + + align:start position:0% +it actually does publish, um you can +even see this on on YouTube. You can see + + align:start position:0% +even see this on on YouTube. You can see + + + align:start position:0% +even see this on on YouTube. You can see +what it's going to look like when you + + align:start position:0% +what it's going to look like when you + + + align:start position:0% +what it's going to look like when you +actually buy the the final game. It + + align:start position:0% +actually buy the the final game. It + + + align:start position:0% +actually buy the the final game. It +plays exactly the same. It looks + + align:start position:0% +plays exactly the same. It looks + + + align:start position:0% +plays exactly the same. It looks +polished. It looks There's It's a really + + align:start position:0% +polished. It looks There's It's a really + + + align:start position:0% +polished. It looks There's It's a really +good example of here's a game that works + + align:start position:0% +good example of here's a game that works + + + align:start position:0% +good example of here's a game that works +and it's functionally perfect and they + + align:start position:0% +and it's functionally perfect and they + + + align:start position:0% +and it's functionally perfect and they +could have just shipped it and I'm + + align:start position:0% +could have just shipped it and I'm + + + align:start position:0% +could have just shipped it and I'm +really glad they did because I played a + + align:start position:0% +really glad they did because I played a + + + align:start position:0% +really glad they did because I played a +lot. Um, and when they finally ship it, + + align:start position:0% +lot. Um, and when they finally ship it, + + + align:start position:0% +lot. Um, and when they finally ship it, +it's still going to play the exact same + + align:start position:0% +it's still going to play the exact same + + + align:start position:0% +it's still going to play the exact same +way. It's just going to be a little bit + + align:start position:0% +way. It's just going to be a little bit + + + align:start position:0% +way. It's just going to be a little bit +prettier and really doesn't m I don't + + align:start position:0% +prettier and really doesn't m I don't + + + align:start position:0% +prettier and really doesn't m I don't +really care about that. Now, that's + + align:start position:0% +really care about that. Now, that's + + + align:start position:0% +really care about that. Now, that's +something that we're going to that we're + + align:start position:0% +something that we're going to that we're + + + align:start position:0% +something that we're going to that we're +going to stress in this game is we're + + align:start position:0% +going to stress in this game is we're + + + align:start position:0% +going to stress in this game is we're +more concerned about that. Is it + + align:start position:0% +more concerned about that. Is it + + + align:start position:0% +more concerned about that. Is it +playable? Does it work? Can I understand + + align:start position:0% +playable? Does it work? Can I understand + + + align:start position:0% +playable? Does it work? Can I understand +how to play it more so than the pretty + + align:start position:0% +how to play it more so than the pretty + + + align:start position:0% +how to play it more so than the pretty +more so than the than the the the + + align:start position:0% +more so than the than the the the + + + align:start position:0% +more so than the than the the the +aesthetic and visual polish. So, in this + + align:start position:0% +aesthetic and visual polish. So, in this + + + align:start position:0% +aesthetic and visual polish. So, in this +game, it is a game about managing a + + align:start position:0% +game, it is a game about managing a + + + align:start position:0% +game, it is a game about managing a +subway. Um, in that all of a sudden, the + + align:start position:0% +subway. Um, in that all of a sudden, the + + + align:start position:0% +subway. Um, in that all of a sudden, the +subway station appears in the middle of + + align:start position:0% +subway station appears in the middle of + + + align:start position:0% +subway station appears in the middle of +space and you have to build a line to + + align:start position:0% +space and you have to build a line to + + + align:start position:0% +space and you have to build a line to +it. So, you build your line um and then + + align:start position:0% +it. So, you build your line um and then + + + align:start position:0% +it. So, you build your line um and then +passengers randomly appear on the subway + + align:start position:0% +passengers randomly appear on the subway + + + align:start position:0% +passengers randomly appear on the subway +trains, but you don't have to actually + + align:start position:0% +trains, but you don't have to actually + + + align:start position:0% +trains, but you don't have to actually +get them from place to place. You don't + + align:start position:0% +get them from place to place. You don't + + + align:start position:0% +get them from place to place. You don't +control the trains. You just build the + + align:start position:0% +control the trains. You just build the + + + align:start position:0% +control the trains. You just build the +lines. The trains move on their own and + + align:start position:0% +lines. The trains move on their own and + + + align:start position:0% +lines. The trains move on their own and +they're moving at a constant rate. So, + + align:start position:0% +they're moving at a constant rate. So, + + + align:start position:0% +they're moving at a constant rate. So, +you can kind of guess when the train is + + align:start position:0% +you can kind of guess when the train is + + + align:start position:0% +you can kind of guess when the train is +going to get to the station. Um there's + + align:start position:0% +going to get to the station. Um there's + + + align:start position:0% +going to get to the station. Um there's +strategies to um you can move your your + + align:start position:0% +strategies to um you can move your your + + + align:start position:0% +strategies to um you can move your your +lines around a little bit, but once your + + align:start position:0% +lines around a little bit, but once your + + + align:start position:0% +lines around a little bit, but once your +lines are in place, for the most part, + + align:start position:0% +lines are in place, for the most part, + + + align:start position:0% +lines are in place, for the most part, +they're static. You can't really change + + align:start position:0% +they're static. You can't really change + + + align:start position:0% +they're static. You can't really change +them all that much. So, there's some + + align:start position:0% +them all that much. So, there's some + + + align:start position:0% +them all that much. So, there's some +limitations going on between how much + + align:start position:0% +limitations going on between how much + + + align:start position:0% +limitations going on between how much +you can move a line or not. Um at the + + align:start position:0% +you can move a line or not. Um at the + + + align:start position:0% +you can move a line or not. Um at the +end, if you last a week, it's going to + + align:start position:0% +end, if you last a week, it's going to + + + align:start position:0% +end, if you last a week, it's going to +give you one of three options to do a + + align:start position:0% +give you one of three options to do a + + + align:start position:0% +give you one of three options to do a +power up. Basically, either you can + + align:start position:0% +power up. Basically, either you can + + + align:start position:0% +power up. Basically, either you can +build a new line, um add a new train, + + align:start position:0% +build a new line, um add a new train, + + + align:start position:0% +build a new line, um add a new train, +increase the capacity of a train. So, + + align:start position:0% +increase the capacity of a train. So, + + + align:start position:0% +increase the capacity of a train. So, +you're you're making a permanent choice + + align:start position:0% +you're you're making a permanent choice + + + align:start position:0% +you're you're making a permanent choice +there, and that's going to affect the + + align:start position:0% +there, and that's going to affect the + + + align:start position:0% +there, and that's going to affect the +later game. So, you're making all sorts + + align:start position:0% +later game. So, you're making all sorts + + + align:start position:0% +later game. So, you're making all sorts +of these decisions at both a macro and a + + align:start position:0% +of these decisions at both a macro and a + + + align:start position:0% +of these decisions at both a macro and a +micro level. Um, there's a really good + + align:start position:0% +micro level. Um, there's a really good + + + align:start position:0% +micro level. Um, there's a really good +write up about the game right there if + + align:start position:0% +write up about the game right there if + + + align:start position:0% +write up about the game right there if +you just want to read + + align:start position:0% +you just want to read + + + align:start position:0% +you just want to read +that. Um, FL, um, I lost a ton of + + align:start position:0% +that. Um, FL, um, I lost a ton of + + + align:start position:0% +that. Um, FL, um, I lost a ton of +productivity a few months ago because of + + align:start position:0% +productivity a few months ago because of + + + align:start position:0% +productivity a few months ago because of +this game. Um, it is a game about + + align:start position:0% +this game. Um, it is a game about + + + align:start position:0% +this game. Um, it is a game about +fighting in spaceships without actually + + align:start position:0% +fighting in spaceships without actually + + + align:start position:0% +fighting in spaceships without actually +controlling all the fighting so much. + + align:start position:0% +controlling all the fighting so much. + + + align:start position:0% +controlling all the fighting so much. +You're actually upgrading your ship, um, + + align:start position:0% +You're actually upgrading your ship, um, + + + align:start position:0% +You're actually upgrading your ship, um, +increasing your your capacity, buying + + align:start position:0% +increasing your your capacity, buying + + + align:start position:0% +increasing your your capacity, buying +crew members, and hoping your crew + + align:start position:0% +crew members, and hoping your crew + + + align:start position:0% +crew members, and hoping your crew +members survive. um is a lot of it. Um + + align:start position:0% +members survive. um is a lot of it. Um + + + align:start position:0% +members survive. um is a lot of it. Um +you could, and I do this, um manually + + align:start position:0% +you could, and I do this, um manually + + + align:start position:0% +you could, and I do this, um manually +control all your weapons. And actually + + align:start position:0% +control all your weapons. And actually + + + align:start position:0% +control all your weapons. And actually +to succeed, you you really do have to um + + align:start position:0% +to succeed, you you really do have to um + + + align:start position:0% +to succeed, you you really do have to um +because the the interesting thing with + + align:start position:0% +because the the interesting thing with + + + align:start position:0% +because the the interesting thing with +this game, it's a perma death game. As + + align:start position:0% +this game, it's a perma death game. As + + + align:start position:0% +this game, it's a perma death game. As +soon as you die, it's dead. You have to + + align:start position:0% +soon as you die, it's dead. You have to + + + align:start position:0% +soon as you die, it's dead. You have to +start over. You have to restart the + + align:start position:0% +start over. You have to restart the + + + align:start position:0% +start over. You have to restart the +game. Luckily, the game only takes about + + align:start position:0% +game. Luckily, the game only takes about + + + align:start position:0% +game. Luckily, the game only takes about +three hours to play. Um but you're lucky + + align:start position:0% +three hours to play. Um but you're lucky + + + align:start position:0% +three hours to play. Um but you're lucky +if you get those through those three + + align:start position:0% +if you get those through those three + + + align:start position:0% +if you get those through those three +hours. So, when you finally get to the + + align:start position:0% +hours. So, when you finally get to the + + + align:start position:0% +hours. So, when you finally get to the +la last boss and you're there and the + + align:start position:0% +la last boss and you're there and the + + + align:start position:0% +la last boss and you're there and the +the thing about about this game is in + + align:start position:0% +the thing about about this game is in + + + align:start position:0% +the thing about about this game is in +order to get to that boss, there's all + + align:start position:0% +order to get to that boss, there's all + + + align:start position:0% +order to get to that boss, there's all +sorts of different challenges you're + + align:start position:0% +sorts of different challenges you're + + + align:start position:0% +sorts of different challenges you're +facing and you're making these decisions + + align:start position:0% +facing and you're making these decisions + + + align:start position:0% +facing and you're making these decisions +about do I buy this weapon or that + + align:start position:0% +about do I buy this weapon or that + + + align:start position:0% +about do I buy this weapon or that +weapon to help me with the thing I know + + align:start position:0% +weapon to help me with the thing I know + + + align:start position:0% +weapon to help me with the thing I know +that I'm going to face in the next + + align:start position:0% +that I'm going to face in the next + + + align:start position:0% +that I'm going to face in the next +sector because I'm I'm losing health. + + align:start position:0% +sector because I'm I'm losing health. + + + align:start position:0% +sector because I'm I'm losing health. +I'm really dying here, but is this + + align:start position:0% +I'm really dying here, but is this + + + align:start position:0% +I'm really dying here, but is this +weapon really going to help me when I + + align:start position:0% +weapon really going to help me when I + + + align:start position:0% +weapon really going to help me when I +get to the boss? Um, you're constantly + + align:start position:0% +get to the boss? Um, you're constantly + + + align:start position:0% +get to the boss? Um, you're constantly +going back and forth. So, I I'll often + + align:start position:0% +going back and forth. So, I I'll often + + + align:start position:0% +going back and forth. So, I I'll often +find out after hour three or four and + + align:start position:0% +find out after hour three or four and + + + align:start position:0% +find out after hour three or four and +I'm at the boss and I'm completely ill + + align:start position:0% +I'm at the boss and I'm completely ill + + + align:start position:0% +I'm at the boss and I'm completely ill +equipped to fight this thing and I just + + align:start position:0% +equipped to fight this thing and I just + + + align:start position:0% +equipped to fight this thing and I just +die. Um, but I do play out to the end + + align:start position:0% +die. Um, but I do play out to the end + + + align:start position:0% +die. Um, but I do play out to the end +because it's fun. Last game I have, um, + + align:start position:0% +because it's fun. Last game I have, um, + + + align:start position:0% +because it's fun. Last game I have, um, +this one's free online. It's called + + align:start position:0% +this one's free online. It's called + + + align:start position:0% +this one's free online. It's called +Gridland. Um, if anybody's played the + + align:start position:0% +Gridland. Um, if anybody's played the + + + align:start position:0% +Gridland. Um, if anybody's played the +game a dark room, a + + align:start position:0% +game a dark room, a + + + align:start position:0% +game a dark room, a +textbased supply chain game. This is the + + align:start position:0% +textbased supply chain game. This is the + + + align:start position:0% +textbased supply chain game. This is the +match three version of that game a + + align:start position:0% +match three version of that game a + + + align:start position:0% +match three version of that game a +little bit. Um, there's two stages in + + align:start position:0% +little bit. Um, there's two stages in + + + align:start position:0% +little bit. Um, there's two stages in +the game, day and night. Um, it's match + + align:start position:0% +the game, day and night. Um, it's match + + + align:start position:0% +the game, day and night. Um, it's match +three, so you just collect three gems + + align:start position:0% +three, so you just collect three gems + + + align:start position:0% +three, so you just collect three gems +and you get whatever the gems represent. + + align:start position:0% +and you get whatever the gems represent. + + + align:start position:0% +and you get whatever the gems represent. +So, um, resources like clay, wood, and + + align:start position:0% +So, um, resources like clay, wood, and + + + align:start position:0% +So, um, resources like clay, wood, and +stone, um, food, paper, um, gems. You + + align:start position:0% +stone, um, food, paper, um, gems. You + + + align:start position:0% +stone, um, food, paper, um, gems. You +can upgrade your little factories to + + align:start position:0% +can upgrade your little factories to + + + align:start position:0% +can upgrade your little factories to +make better gems. Every time you upgrade + + align:start position:0% +make better gems. Every time you upgrade + + + align:start position:0% +make better gems. Every time you upgrade +one of these, though, like, so if you + + align:start position:0% +one of these, though, like, so if you + + + align:start position:0% +one of these, though, like, so if you +upgrade your wood, you'll get a better + + align:start position:0% +upgrade your wood, you'll get a better + + + align:start position:0% +upgrade your wood, you'll get a better +sword. If you upgrade your clay, which + + align:start position:0% +sword. If you upgrade your clay, which + + + align:start position:0% +sword. If you upgrade your clay, which +you need to get to to to make the better + + align:start position:0% +you need to get to to to make the better + + + align:start position:0% +you need to get to to to make the better +wood, you're going to get in the + + align:start position:0% +wood, you're going to get in the + + + align:start position:0% +wood, you're going to get in the +nighttime a stronger monster. So in this + + align:start position:0% +nighttime a stronger monster. So in this + + + align:start position:0% +nighttime a stronger monster. So in this +case, this is immediately daytime and + + align:start position:0% +case, this is immediately daytime and + + + align:start position:0% +case, this is immediately daytime and +then shifted over to night. The exact + + align:start position:0% +then shifted over to night. The exact + + + align:start position:0% +then shifted over to night. The exact +same layout is there. It's just the the + + align:start position:0% +same layout is there. It's just the the + + + align:start position:0% +same layout is there. It's just the the +the logs have become shields. The little + + align:start position:0% +the logs have become shields. The little + + + align:start position:0% +the logs have become shields. The little +blue things are that are supposed to be + + align:start position:0% +blue things are that are supposed to be + + + align:start position:0% +blue things are that are supposed to be +iron become swords and all the other + + align:start position:0% +iron become swords and all the other + + + align:start position:0% +iron become swords and all the other +things become um enemies. + + align:start position:0% +things become um enemies. + + + align:start position:0% +things become um enemies. +So, a lot of the the strategy for this + + align:start position:0% +So, a lot of the the strategy for this + + + align:start position:0% +So, a lot of the the strategy for this +game is what's going to help me now, + + align:start position:0% +game is what's going to help me now, + + + align:start position:0% +game is what's going to help me now, +what's going to help me in the f what's + + align:start position:0% +what's going to help me in the f what's + + + align:start position:0% +what's going to help me in the f what's +going to help me in the future, what's + + align:start position:0% +going to help me in the future, what's + + + align:start position:0% +going to help me in the future, what's +going to hurt me in the future, and + + align:start position:0% +going to hurt me in the future, and + + + align:start position:0% +going to hurt me in the future, and +what's going to hurt me immediately as I + + align:start position:0% +what's going to hurt me immediately as I + + + align:start position:0% +what's going to hurt me immediately as I +switch over to to tonight. Once I get + + align:start position:0% +switch over to to tonight. Once I get + + + align:start position:0% +switch over to to tonight. Once I get +into the into the night mode, I'll have + + align:start position:0% +into the into the night mode, I'll have + + + align:start position:0% +into the into the night mode, I'll have +known exactly what I'm going to be + + align:start position:0% +known exactly what I'm going to be + + + align:start position:0% +known exactly what I'm going to be +facing because I set that I set that + + align:start position:0% +facing because I set that I set that + + + align:start position:0% +facing because I set that I set that +stage up. So, unlike Bejeweled where + + align:start position:0% +stage up. So, unlike Bejeweled where + + + align:start position:0% +stage up. So, unlike Bejeweled where +you're just constantly just clicking + + align:start position:0% +you're just constantly just clicking + + + align:start position:0% +you're just constantly just clicking +things or Candy Crush where you're just + + align:start position:0% +things or Candy Crush where you're just + + + align:start position:0% +things or Candy Crush where you're just +constantly just kicking things, there's + + align:start position:0% +constantly just kicking things, there's + + + align:start position:0% +constantly just kicking things, there's +actually no time limit on this. And it + + align:start position:0% +actually no time limit on this. And it + + + align:start position:0% +actually no time limit on this. And it +took me, it's embarrassing how long it + + align:start position:0% +took me, it's embarrassing how long it + + + align:start position:0% +took me, it's embarrassing how long it +took me a day or two to realize that I + + align:start position:0% +took me a day or two to realize that I + + + align:start position:0% +took me a day or two to realize that I +didn't have to play that way, that I + + align:start position:0% +didn't have to play that way, that I + + + align:start position:0% +didn't have to play that way, that I +could just wait, pause, and play. That + + align:start position:0% +could just wait, pause, and play. That + + + align:start position:0% +could just wait, pause, and play. That +there wasn't going to be a time limit + + align:start position:0% +there wasn't going to be a time limit + + + align:start position:0% +there wasn't going to be a time limit +pushing me to to to keep to continue + + align:start position:0% +pushing me to to to keep to continue + + + align:start position:0% +pushing me to to to keep to continue +moving forward. Um, so, and that's a + + align:start position:0% +moving forward. Um, so, and that's a + + + align:start position:0% +moving forward. Um, so, and that's a +that's an interesting presentation thing + + align:start position:0% +that's an interesting presentation thing + + + align:start position:0% +that's an interesting presentation thing +when you're when you're presenting your + + align:start position:0% +when you're when you're presenting your + + + align:start position:0% +when you're when you're presenting your +games, especially if you're using a + + align:start position:0% +games, especially if you're using a + + + align:start position:0% +games, especially if you're using a +previous genre, there's going to be + + align:start position:0% +previous genre, there's going to be + + + align:start position:0% +previous genre, there's going to be +genre conventions that that the players + + align:start position:0% +genre conventions that that the players + + + align:start position:0% +genre conventions that that the players +are going to understand that is going to + + align:start position:0% +are going to understand that is going to + + + align:start position:0% +are going to understand that is going to +shape their user experience. And we'll + + align:start position:0% +shape their user experience. And we'll + + + align:start position:0% +shape their user experience. And we'll +be talking about that about project 3. + + align:start position:0% +be talking about that about project 3. + + + align:start position:0% +be talking about that about project 3. +So, that's it. Um, if you want to do if + + align:start position:0% +So, that's it. Um, if you want to do if + + + align:start position:0% +So, that's it. Um, if you want to do if +you want to play these games or watch + + align:start position:0% +you want to play these games or watch + + + align:start position:0% +you want to play these games or watch +these games on YouTube, please do. And + + align:start position:0% +these games on YouTube, please do. And + + + align:start position:0% +these games on YouTube, please do. And +if you want to know more about choice + + align:start position:0% +if you want to know more about choice + + + align:start position:0% +if you want to know more about choice +and conflict, there's a 9-minute video + + align:start position:0% +and conflict, there's a 9-minute video + + + align:start position:0% +and conflict, there's a 9-minute video +at Extra Credits. We use Extra Credits a + + align:start position:0% +at Extra Credits. We use Extra Credits a + + + align:start position:0% +at Extra Credits. We use Extra Credits a +lot because they're they're short. + + align:start position:0% +lot because they're they're short. + + + align:start position:0% +lot because they're they're short. +They're fun. Um, videos on game design. + + align:start position:0% +They're fun. Um, videos on game design. + + + align:start position:0% +They're fun. Um, videos on game design. +I highly recommended for this class to + + align:start position:0% +I highly recommended for this class to + + + align:start position:0% +I highly recommended for this class to +give you a leg up on some of the design + + align:start position:0% +give you a leg up on some of the design + + + align:start position:0% +give you a leg up on some of the design +challenges that we're facing here. \ No newline at end of file diff --git a/qq7I2MQNrtU.txt b/qq7I2MQNrtU.txt new file mode 100644 index 0000000000000000000000000000000000000000..f97a76f17d9c52d9f5f2eeb2f1de13158857ffe8 --- /dev/null +++ b/qq7I2MQNrtU.txt @@ -0,0 +1,379 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +Okay, we have our + + align:start position:0% +Okay, we have our + + + align:start position:0% +Okay, we have our +class. We've + + align:start position:0% +class. We've + + + align:start position:0% +class. We've +done pretty much everything up until + + align:start position:0% +done pretty much everything up until + + + align:start position:0% +done pretty much everything up until +here. And we're going to + + align:start position:0% +here. And we're going to + + + align:start position:0% +here. And we're going to +add this special function here. So, + + align:start position:0% +add this special function here. So, + + + align:start position:0% +add this special function here. So, +we're implementing this + + align:start position:0% + + + + align:start position:0% + +underscore_eq_. And implementing this is + + align:start position:0% +underscore_eq_. And implementing this is + + + align:start position:0% +underscore_eq_. And implementing this is +going to is going to allow us to compare + + align:start position:0% +going to is going to allow us to compare + + + align:start position:0% +going to is going to allow us to compare +two types of cars. + + align:start position:0% + + + + align:start position:0% + +So, the way I've decided to compare two + + align:start position:0% +So, the way I've decided to compare two + + + align:start position:0% +So, the way I've decided to compare two +types of cars is I'm saying the two cars + + align:start position:0% +types of cars is I'm saying the two cars + + + align:start position:0% +types of cars is I'm saying the two cars +are going to be equal if they have the + + align:start position:0% +are going to be equal if they have the + + + align:start position:0% +are going to be equal if they have the +same number of wheels, they have the + + align:start position:0% +same number of wheels, they have the + + + align:start position:0% +same number of wheels, they have the +same color, and if they have the same um + + align:start position:0% +same color, and if they have the same um + + + align:start position:0% +same color, and if they have the same um +number of + + align:start position:0% +number of + + + align:start position:0% +number of +doors. Okay, so if all of these are + + align:start position:0% +doors. Okay, so if all of these are + + + align:start position:0% +doors. Okay, so if all of these are +equal, then return true and else return + + align:start position:0% + + + + align:start position:0% + +false. Inside the actual program here, + + align:start position:0% +false. Inside the actual program here, + + + align:start position:0% +false. Inside the actual program here, +I'm creating one car, four wheels, two + + align:start position:0% +I'm creating one car, four wheels, two + + + align:start position:0% +I'm creating one car, four wheels, two +doors. I'm changing its color to red. + + align:start position:0% +doors. I'm changing its color to red. + + + align:start position:0% +doors. I'm changing its color to red. +I'm creating another car, four wheels, + + align:start position:0% +I'm creating another car, four wheels, + + + align:start position:0% +I'm creating another car, four wheels, +two + + align:start position:0% +two + + + align:start position:0% +two +doors. By default, this new car or your + + align:start position:0% +doors. By default, this new car or your + + + align:start position:0% +doors. By default, this new car or your +car is going to have the color empty + + align:start position:0% +car is going to have the color empty + + + align:start position:0% +car is going to have the color empty +string because that's how a new car gets + + align:start position:0% +string because that's how a new car gets + + + align:start position:0% +string because that's how a new car gets +initialized, + + align:start position:0% + + + + align:start position:0% + +right? So between my car and your car, + + align:start position:0% +right? So between my car and your car, + + + align:start position:0% +right? So between my car and your car, +the difference is going to be the color. + + align:start position:0% +the difference is going to be the color. + + + align:start position:0% +the difference is going to be the color. +Okay? So the color is not going to be + + align:start position:0% +Okay? So the color is not going to be + + + align:start position:0% +Okay? So the color is not going to be +the same. They have the same number of + + align:start position:0% +the same. They have the same number of + + + align:start position:0% +the same. They have the same number of +wheels and the same number of + + align:start position:0% +wheels and the same number of + + + align:start position:0% +wheels and the same number of +doors. So when So because I implemented + + align:start position:0% +doors. So when So because I implemented + + + align:start position:0% +doors. So when So because I implemented +the equal method in my code, this does + + align:start position:0% +the equal method in my code, this does + + + align:start position:0% +the equal method in my code, this does +not throw an error. This lets me + + align:start position:0% +not throw an error. This lets me + + + align:start position:0% +not throw an error. This lets me +proceed. It compares four with four, + + align:start position:0% +proceed. It compares four with four, + + + align:start position:0% +proceed. It compares four with four, +which is good. Two with two, which is + + align:start position:0% +which is good. Two with two, which is + + + align:start position:0% +which is good. Two with two, which is +good, and then the colors don't match. + + align:start position:0% +good, and then the colors don't match. + + + align:start position:0% +good, and then the colors don't match. +So it's going to say + + align:start position:0% +So it's going to say + + + align:start position:0% +So it's going to say +false, which most of you guys are + + align:start position:0% +false, which most of you guys are + + + align:start position:0% +false, which most of you guys are +getting it right. \ No newline at end of file diff --git a/r2_-2KW76ec.txt b/r2_-2KW76ec.txt new file mode 100644 index 0000000000000000000000000000000000000000..298232cf1ded62b1c67124a1e6e698695ee409a1 --- /dev/null +++ b/r2_-2KW76ec.txt @@ -0,0 +1,11211 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu + + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu +so I am gonna start this talk by + + align:start position:0% +so I am gonna start this talk by + + + align:start position:0% +so I am gonna start this talk by +explaining the title so we'll start with + + align:start position:0% +explaining the title so we'll start with + + + align:start position:0% +explaining the title so we'll start with +active learning alright what is active + + align:start position:0% +active learning alright what is active + + + align:start position:0% +active learning alright what is active +learning in my mind it's this pretty + + align:start position:0% +learning in my mind it's this pretty + + + align:start position:0% +learning in my mind it's this pretty +broad term it's a form of learning that + + align:start position:0% +broad term it's a form of learning that + + + align:start position:0% +broad term it's a form of learning that +in tempts to involve students more + + align:start position:0% +in tempts to involve students more + + + align:start position:0% +in tempts to involve students more +directly in the learning process and + + align:start position:0% +directly in the learning process and + + + align:start position:0% +directly in the learning process and +there are all sorts of things that fall + + align:start position:0% +there are all sorts of things that fall + + + align:start position:0% +there are all sorts of things that fall +under the umbrella of active learning so + + align:start position:0% +under the umbrella of active learning so + + + align:start position:0% +under the umbrella of active learning so +things like having students engage in + + align:start position:0% +things like having students engage in + + + align:start position:0% +things like having students engage in +group work and classified discussions + + align:start position:0% +group work and classified discussions + + + align:start position:0% +group work and classified discussions +and debates acting out certain concepts + + align:start position:0% +and debates acting out certain concepts + + + align:start position:0% +and debates acting out certain concepts +group problem solving sessions all of + + align:start position:0% +group problem solving sessions all of + + + align:start position:0% +group problem solving sessions all of +these things and so when all of those + + align:start position:0% +these things and so when all of those + + + align:start position:0% +these things and so when all of those +activities students are engaged they're + + align:start position:0% +activities students are engaged they're + + + align:start position:0% +activities students are engaged they're +not passively listening to a lecture + + align:start position:0% +not passively listening to a lecture + + + align:start position:0% +not passively listening to a lecture +they're actively participating and you + + align:start position:0% +they're actively participating and you + + + align:start position:0% +they're actively participating and you +know there is some evidence that this + + align:start position:0% +know there is some evidence that this + + + align:start position:0% +know there is some evidence that this +style of learning is good for a lot of + + align:start position:0% +style of learning is good for a lot of + + + align:start position:0% +style of learning is good for a lot of +things there's evidence to in to support + + align:start position:0% +things there's evidence to in to support + + + align:start position:0% +things there's evidence to in to support +the effectiveness of student engagement + + align:start position:0% +the effectiveness of student engagement + + + align:start position:0% +the effectiveness of student engagement +in you know exam scores failure rates + + align:start position:0% +in you know exam scores failure rates + + + align:start position:0% +in you know exam scores failure rates +how well students remember content + + align:start position:0% +how well students remember content + + + align:start position:0% +how well students remember content +student attitudes study habits there's + + align:start position:0% +student attitudes study habits there's + + + align:start position:0% +student attitudes study habits there's +also evidence that active learning has a + + align:start position:0% +also evidence that active learning has a + + + align:start position:0% +also evidence that active learning has a +disproportionate benefit for minorities + + align:start position:0% +disproportionate benefit for minorities + + + align:start position:0% +disproportionate benefit for minorities +the students from disadvantaged + + align:start position:0% +the students from disadvantaged + + + align:start position:0% +the students from disadvantaged +backgrounds female students and + + align:start position:0% +backgrounds female students and + + + align:start position:0% +backgrounds female students and +male-dominated fields so there's + + align:start position:0% +male-dominated fields so there's + + + align:start position:0% +male-dominated fields so there's +evidence that active learning creates + + align:start position:0% +evidence that active learning creates + + + align:start position:0% +evidence that active learning creates +this you know more inclusive environment + + align:start position:0% +this you know more inclusive environment + + + align:start position:0% +this you know more inclusive environment +so you know it's this wide wide variety + + align:start position:0% +so you know it's this wide wide variety + + + align:start position:0% +so you know it's this wide wide variety +of techniques reported to have a lot of + + align:start position:0% +of techniques reported to have a lot of + + + align:start position:0% +of techniques reported to have a lot of +benefits so that's active learning now + + align:start position:0% +benefits so that's active learning now + + + align:start position:0% +benefits so that's active learning now +what is six oh three three so six oh + + align:start position:0% +what is six oh three three so six oh + + + align:start position:0% +what is six oh three three so six oh +three three is computer systems + + align:start position:0% +three three is computer systems + + + align:start position:0% +three three is computer systems +engineering it's a required class for + + align:start position:0% +engineering it's a required class for + + + align:start position:0% +engineering it's a required class for +all computer science majors which means + + align:start position:0% +all computer science majors which means + + + align:start position:0% +all computer science majors which means +as a result at MIT it's quite large so + + align:start position:0% +as a result at MIT it's quite large so + + + align:start position:0% +as a result at MIT it's quite large so +like Deepa said we have about 400 + + align:start position:0% +like Deepa said we have about 400 + + + align:start position:0% +like Deepa said we have about 400 +students it runs once a year so every + + align:start position:0% +students it runs once a year so every + + + align:start position:0% +students it runs once a year so every +spring we get 400 400 new students most + + align:start position:0% +spring we get 400 400 new students most + + + align:start position:0% +spring we get 400 400 new students most +of them are juniors and seniors and in + + align:start position:0% +of them are juniors and seniors and in + + + align:start position:0% +of them are juniors and seniors and in +some ways oh three three is a typical + + align:start position:0% +some ways oh three three is a typical + + + align:start position:0% +some ways oh three three is a typical +MIT class we have + + align:start position:0% +MIT class we have + + + align:start position:0% +MIT class we have +just twice a week we have recitations + + align:start position:0% +just twice a week we have recitations + + + align:start position:0% +just twice a week we have recitations +twice a week but in most other ways oh + + align:start position:0% +twice a week but in most other ways oh + + + align:start position:0% +twice a week but in most other ways oh +33 is not a typical MIT class for one + + align:start position:0% +33 is not a typical MIT class for one + + + align:start position:0% +33 is not a typical MIT class for one +it's a CI M class so it's a + + align:start position:0% +it's a CI M class so it's a + + + align:start position:0% +it's a CI M class so it's a +communications intensive in the major + + align:start position:0% +communications intensive in the major + + + align:start position:0% +communications intensive in the major +class that means that most of our + + align:start position:0% +class that means that most of our + + + align:start position:0% +class that means that most of our +assignments are based around writing or + + align:start position:0% +assignments are based around writing or + + + align:start position:0% +assignments are based around writing or +oral presentations it's not a class + + align:start position:0% +oral presentations it's not a class + + + align:start position:0% +oral presentations it's not a class +where students are implementing or + + align:start position:0% +where students are implementing or + + + align:start position:0% +where students are implementing or +building a lot of things you know we + + align:start position:0% +building a lot of things you know we + + + align:start position:0% +building a lot of things you know we +focus heavily on reading and on writing + + align:start position:0% +focus heavily on reading and on writing + + + align:start position:0% +focus heavily on reading and on writing +in particular we have tutorial sections + + align:start position:0% +in particular we have tutorial sections + + + align:start position:0% +in particular we have tutorial sections +each week dedicated to the community + + align:start position:0% +each week dedicated to the community + + + align:start position:0% +each week dedicated to the community +communication material taught by + + align:start position:0% +communication material taught by + + + align:start position:0% +communication material taught by +dedicated communication staff the major + + align:start position:0% +dedicated communication staff the major + + + align:start position:0% +dedicated communication staff the major +assignment in o33 is a design project it + + align:start position:0% +assignment in o33 is a design project it + + + align:start position:0% +assignment in o33 is a design project it +takes most of the semester the students + + align:start position:0% +takes most of the semester the students + + + align:start position:0% +takes most of the semester the students +completed in teams usually teams of + + align:start position:0% +completed in teams usually teams of + + + align:start position:0% +completed in teams usually teams of +three and it's comprised of a few + + align:start position:0% +three and it's comprised of a few + + + align:start position:0% +three and it's comprised of a few +written assignments and oral + + align:start position:0% +written assignments and oral + + + align:start position:0% +written assignments and oral +presentations one of our big focuses for + + align:start position:0% +presentations one of our big focuses for + + + align:start position:0% +presentations one of our big focuses for +that project is getting students to + + align:start position:0% +that project is getting students to + + + align:start position:0% +that project is getting students to +recognize the trade-offs they need to + + align:start position:0% +recognize the trade-offs they need to + + + align:start position:0% +recognize the trade-offs they need to +make when they're designing a system and + + align:start position:0% +make when they're designing a system and + + + align:start position:0% +make when they're designing a system and +getting them to defend those trade-offs + + align:start position:0% +getting them to defend those trade-offs + + + align:start position:0% +getting them to defend those trade-offs +so this is not just a class about how + + align:start position:0% +so this is not just a class about how + + + align:start position:0% +so this is not just a class about how +computer systems work but you know how + + align:start position:0% +computer systems work but you know how + + + align:start position:0% +computer systems work but you know how +we design them how we decide what + + align:start position:0% +we design them how we decide what + + + align:start position:0% +we design them how we decide what +choices to make when we're building + + align:start position:0% +choices to make when we're building + + + align:start position:0% +choices to make when we're building +those systems so the last thing that + + align:start position:0% +those systems so the last thing that + + + align:start position:0% +those systems so the last thing that +makes over 33 pretty unique and is what + + align:start position:0% +makes over 33 pretty unique and is what + + + align:start position:0% +makes over 33 pretty unique and is what +I'm largely going to talk about here is + + align:start position:0% +I'm largely going to talk about here is + + + align:start position:0% +I'm largely going to talk about here is +that our recitation sections are pretty + + align:start position:0% +that our recitation sections are pretty + + + align:start position:0% +that our recitation sections are pretty +intense they're taught by faculty senior + + align:start position:0% +intense they're taught by faculty senior + + + align:start position:0% +intense they're taught by faculty senior +research staff we have about 25 students + + align:start position:0% +research staff we have about 25 students + + + align:start position:0% +research staff we have about 25 students +per Section so you are right to think + + align:start position:0% +per Section so you are right to think + + + align:start position:0% +per Section so you are right to think +that oh my gosh they have like 18 + + align:start position:0% +that oh my gosh they have like 18 + + + align:start position:0% +that oh my gosh they have like 18 +sections per semester we do it's a lot + + align:start position:0% +sections per semester we do it's a lot + + + align:start position:0% +sections per semester we do it's a lot +each recitation focuses around a + + align:start position:0% +each recitation focuses around a + + + align:start position:0% +each recitation focuses around a +technical paper that the students have + + align:start position:0% +technical paper that the students have + + + align:start position:0% +technical paper that the students have +read beforehand the goal for those + + align:start position:0% +read beforehand the goal for those + + + align:start position:0% +read beforehand the goal for those +discussion sections those recitations is + + align:start position:0% +discussion sections those recitations is + + + align:start position:0% +discussion sections those recitations is +for them to be largely discussion based + + align:start position:0% +for them to be largely discussion based + + + align:start position:0% +for them to be largely discussion based +and in fact that has always been the + + align:start position:0% +and in fact that has always been the + + + align:start position:0% +and in fact that has always been the +goal of oh 33 other thinking has been + + align:start position:0% +goal of oh 33 other thinking has been + + + align:start position:0% +goal of oh 33 other thinking has been +around for almost 50 years at this point + + align:start position:0% +around for almost 50 years at this point + + + align:start position:0% +around for almost 50 years at this point +since it's been around since before I + + align:start position:0% +since it's been around since before I + + + align:start position:0% +since it's been around since before I +was born and and the goal has always + + align:start position:0% +was born and and the goal has always + + + align:start position:0% +was born and and the goal has always +been for these recitations to be + + align:start position:0% +been for these recitations to be + + + align:start position:0% +been for these recitations to be +discussion based during the recitations + + align:start position:0% +discussion based during the recitations + + + align:start position:0% +discussion based during the recitations +we're talking about you know we talked + + align:start position:0% +we're talking about you know we talked + + + align:start position:0% +we're talking about you know we talked +about the system that the paper + + align:start position:0% +about the system that the paper + + + align:start position:0% +about the system that the paper +describes but you know doesn't work what + + align:start position:0% +describes but you know doesn't work what + + + align:start position:0% +describes but you know doesn't work what +were the trade-offs that the authors + + align:start position:0% +were the trade-offs that the authors + + + align:start position:0% +were the trade-offs that the authors +made do we like this system how would + + align:start position:0% +made do we like this system how would + + + align:start position:0% +made do we like this system how would +you design this system all right + + align:start position:0% +you design this system all right + + + align:start position:0% +you design this system all right +so that is oh three three now + + align:start position:0% +so that is oh three three now + + + align:start position:0% +so that is oh three three now +why put active learning in two oh three + + align:start position:0% +why put active learning in two oh three + + + align:start position:0% +why put active learning in two oh three +three and you know you might think that + + align:start position:0% +three and you know you might think that + + + align:start position:0% +three and you know you might think that +it's just because well there's evidence + + align:start position:0% +it's just because well there's evidence + + + align:start position:0% +it's just because well there's evidence +that active learning can be a good idea + + align:start position:0% +that active learning can be a good idea + + + align:start position:0% +that active learning can be a good idea +so you know why not try it that's fair + + align:start position:0% +so you know why not try it that's fair + + + align:start position:0% +so you know why not try it that's fair +we were actually trying to solve a + + align:start position:0% +we were actually trying to solve a + + + align:start position:0% +we were actually trying to solve a +pretty specific problem in the class + + align:start position:0% +pretty specific problem in the class + + + align:start position:0% +pretty specific problem in the class +though so like I said ideally the + + align:start position:0% +though so like I said ideally the + + + align:start position:0% +though so like I said ideally the +recitations are based heavily around + + align:start position:0% +recitations are based heavily around + + + align:start position:0% +recitations are based heavily around +discussion and again that has always + + align:start position:0% +discussion and again that has always + + + align:start position:0% +discussion and again that has always +been the goal because this is a class + + align:start position:0% +been the goal because this is a class + + + align:start position:0% +been the goal because this is a class +about system design not just about how + + align:start position:0% +about system design not just about how + + + align:start position:0% +about system design not just about how +these systems work one way that we teach + + align:start position:0% +these systems work one way that we teach + + + align:start position:0% +these systems work one way that we teach +that is by having the students analyze + + align:start position:0% +that is by having the students analyze + + + align:start position:0% +that is by having the students analyze +and critique existing systems before + + align:start position:0% +and critique existing systems before + + + align:start position:0% +and critique existing systems before +they go out and try to design their own + + align:start position:0% +they go out and try to design their own + + + align:start position:0% +they go out and try to design their own +and so you know what are the goals of + + align:start position:0% +and so you know what are the goals of + + + align:start position:0% +and so you know what are the goals of +the designers does the system meet those + + align:start position:0% +the designers does the system meet those + + + align:start position:0% +the designers does the system meet those +goals are those goals important if you + + align:start position:0% +goals are those goals important if you + + + align:start position:0% +goals are those goals important if you +were redesigning the system how would + + align:start position:0% +were redesigning the system how would + + + align:start position:0% +were redesigning the system how would +you do it what would your goals be what + + align:start position:0% +you do it what would your goals be what + + + align:start position:0% +you do it what would your goals be what +trade-offs would you have to make things + + align:start position:0% +trade-offs would you have to make things + + + align:start position:0% +trade-offs would you have to make things +like that a large part of that + + align:start position:0% +like that a large part of that + + + align:start position:0% +like that a large part of that +instruction happens in the recitation + + align:start position:0% +instruction happens in the recitation + + + align:start position:0% +instruction happens in the recitation +when we're having these discussions and + + align:start position:0% +when we're having these discussions and + + + align:start position:0% +when we're having these discussions and +then they going to apply those skills to + + align:start position:0% +then they going to apply those skills to + + + align:start position:0% +then they going to apply those skills to +their design projects so to get that to + + align:start position:0% +their design projects so to get that to + + + align:start position:0% +their design projects so to get that to +happen it's important that the students + + align:start position:0% +happen it's important that the students + + + align:start position:0% +happen it's important that the students +are engaged in recitation that they're + + align:start position:0% +are engaged in recitation that they're + + + align:start position:0% +are engaged in recitation that they're +reading the paper beforehand + + align:start position:0% +reading the paper beforehand + + + align:start position:0% +reading the paper beforehand +they're asking questions they're + + align:start position:0% +they're asking questions they're + + + align:start position:0% +they're asking questions they're +answering questions they're coming + + align:start position:0% +answering questions they're coming + + + align:start position:0% +answering questions they're coming +prepared things like that and for a long + + align:start position:0% +prepared things like that and for a long + + + align:start position:0% +prepared things like that and for a long +time that was not happening for us we + + align:start position:0% +time that was not happening for us we + + + align:start position:0% +time that was not happening for us we +had a lot of trouble with this we found + + align:start position:0% +had a lot of trouble with this we found + + + align:start position:0% +had a lot of trouble with this we found +that students weren't willing to + + align:start position:0% +that students weren't willing to + + + align:start position:0% +that students weren't willing to +volunteer answers right well we'd ask + + align:start position:0% +volunteer answers right well we'd ask + + + align:start position:0% +volunteer answers right well we'd ask +them a question nobody would raise their + + align:start position:0% +them a question nobody would raise their + + + align:start position:0% +them a question nobody would raise their +hand we found that some of them weren't + + align:start position:0% +hand we found that some of them weren't + + + align:start position:0% +hand we found that some of them weren't +even reading the paper beforehand so + + align:start position:0% +even reading the paper beforehand so + + + align:start position:0% +even reading the paper beforehand so +they're just kind of coming and confused + + align:start position:0% +they're just kind of coming and confused + + + align:start position:0% +they're just kind of coming and confused +as a result of all of this + + align:start position:0% +as a result of all of this + + + align:start position:0% +as a result of all of this +our instructors would end up spending + + align:start position:0% +our instructors would end up spending + + + align:start position:0% +our instructors would end up spending +the first you know 15 20 25 minutes of + + align:start position:0% +the first you know 15 20 25 minutes of + + + align:start position:0% +the first you know 15 20 25 minutes of +the recitation lecturing about the paper + + align:start position:0% +the recitation lecturing about the paper + + + align:start position:0% +the recitation lecturing about the paper +right because so many of the students + + align:start position:0% +right because so many of the students + + + align:start position:0% +right because so many of the students +didn't come prepared and then that just + + align:start position:0% +didn't come prepared and then that just + + + align:start position:0% +didn't come prepared and then that just +made things worse as you can imagine + + align:start position:0% +made things worse as you can imagine + + + align:start position:0% +made things worse as you can imagine +students know that they're going to come + + align:start position:0% +students know that they're going to come + + + align:start position:0% +students know that they're going to come +into recitation that they're gonna get a + + align:start position:0% +into recitation that they're gonna get a + + + align:start position:0% +into recitation that they're gonna get a +lecture so why bother reading the paper + + align:start position:0% +lecture so why bother reading the paper + + + align:start position:0% +lecture so why bother reading the paper +if your instructor is just going to + + align:start position:0% +if your instructor is just going to + + + align:start position:0% +if your instructor is just going to +explain it to you + + align:start position:0% +explain it to you + + + align:start position:0% +explain it to you +it was just kind of making things worse + + align:start position:0% +it was just kind of making things worse + + + align:start position:0% +it was just kind of making things worse +we weren't getting to teach the material + + align:start position:0% +we weren't getting to teach the material + + + align:start position:0% +we weren't getting to teach the material +that we really needed to teach because + + align:start position:0% +that we really needed to teach because + + + align:start position:0% +that we really needed to teach because +we're spending time rehashing these + + align:start position:0% +we're spending time rehashing these + + + align:start position:0% +we're spending time rehashing these +papers the students weren't learning how + + align:start position:0% +papers the students weren't learning how + + + align:start position:0% +papers the students weren't learning how +to read these papers how to analyze them + + align:start position:0% +to read these papers how to analyze them + + + align:start position:0% +to read these papers how to analyze them +how to critique them + + align:start position:0% +how to critique them + + + align:start position:0% +how to critique them +and honestly it wasn't much fun it + + align:start position:0% +and honestly it wasn't much fun it + + + align:start position:0% +and honestly it wasn't much fun it +wasn't much fun to teach this way + + align:start position:0% +wasn't much fun to teach this way + + + align:start position:0% +wasn't much fun to teach this way +occasionally we could get a discussion + + align:start position:0% +occasionally we could get a discussion + + + align:start position:0% +occasionally we could get a discussion +as the discussion going in a class but + + align:start position:0% +as the discussion going in a class but + + + align:start position:0% +as the discussion going in a class but +we would then encounter you know another + + align:start position:0% +we would then encounter you know another + + + align:start position:0% +we would then encounter you know another +problem which is pretty common where + + align:start position:0% +problem which is pretty common where + + + align:start position:0% +problem which is pretty common where +we'd have a discussion but it would be + + align:start position:0% +we'd have a discussion but it would be + + + align:start position:0% +we'd have a discussion but it would be +dominated by two or three students in + + align:start position:0% +dominated by two or three students in + + + align:start position:0% +dominated by two or three students in +the room right at the same two or three + + align:start position:0% +the room right at the same two or three + + + align:start position:0% +the room right at the same two or three +students and then you know how their + + align:start position:0% +students and then you know how their + + + align:start position:0% +students and then you know how their +students are tuning out or kind of even + + align:start position:0% +students are tuning out or kind of even + + + align:start position:0% +students are tuning out or kind of even +becoming sort of visibly like + + align:start position:0% +becoming sort of visibly like + + + align:start position:0% +becoming sort of visibly like +uncomfortable not wanting to volunteer + + align:start position:0% +uncomfortable not wanting to volunteer + + + align:start position:0% +uncomfortable not wanting to volunteer +these these answers so that's where we + + align:start position:0% +these these answers so that's where we + + + align:start position:0% +these these answers so that's where we +were and we have this problem we really + + align:start position:0% +were and we have this problem we really + + + align:start position:0% +were and we have this problem we really +wanted the recitations to be this you + + align:start position:0% +wanted the recitations to be this you + + + align:start position:0% +wanted the recitations to be this you +know like really fun place where the + + align:start position:0% +know like really fun place where the + + + align:start position:0% +know like really fun place where the +students were coming and they're + + align:start position:0% +students were coming and they're + + + align:start position:0% +students were coming and they're +wrestling with all of these new ideas + + align:start position:0% +wrestling with all of these new ideas + + + align:start position:0% +wrestling with all of these new ideas +and proposing these new things but we + + align:start position:0% +and proposing these new things but we + + + align:start position:0% +and proposing these new things but we +didn't have that we had this place where + + align:start position:0% +didn't have that we had this place where + + + align:start position:0% +didn't have that we had this place where +students aren't coming prepared or if + + align:start position:0% +students aren't coming prepared or if + + + align:start position:0% +students aren't coming prepared or if +they're prepared you know if we can get + + align:start position:0% +they're prepared you know if we can get + + + align:start position:0% +they're prepared you know if we can get +a discussion going it's not the kind of + + align:start position:0% +a discussion going it's not the kind of + + + align:start position:0% +a discussion going it's not the kind of +discussion we want it's sort of + + align:start position:0% +discussion we want it's sort of + + + align:start position:0% +discussion we want it's sort of +dominated by one or two people so after + + align:start position:0% +dominated by one or two people so after + + + align:start position:0% +dominated by one or two people so after +some thinking I thought you know active + + align:start position:0% +some thinking I thought you know active + + + align:start position:0% +some thinking I thought you know active +learning might be a good approach to + + align:start position:0% +learning might be a good approach to + + + align:start position:0% +learning might be a good approach to +solve both of these problems right so as + + align:start position:0% +solve both of these problems right so as + + + align:start position:0% +solve both of these problems right so as +I mentioned earlier there's some + + align:start position:0% +I mentioned earlier there's some + + + align:start position:0% +I mentioned earlier there's some +evidence that active learning can be + + align:start position:0% +evidence that active learning can be + + + align:start position:0% +evidence that active learning can be +good for creating an inclusive + + align:start position:0% +good for creating an inclusive + + + align:start position:0% +good for creating an inclusive +environment in a classroom so for + + align:start position:0% +environment in a classroom so for + + + align:start position:0% +environment in a classroom so for +instance one common technique which I + + align:start position:0% +instance one common technique which I + + + align:start position:0% +instance one common technique which I +will talk a bit about later is you know + + align:start position:0% +will talk a bit about later is you know + + + align:start position:0% +will talk a bit about later is you know +we pose a question to the class but put + + align:start position:0% +we pose a question to the class but put + + + align:start position:0% +we pose a question to the class but put +everybody in small groups have the + + align:start position:0% +everybody in small groups have the + + + align:start position:0% +everybody in small groups have the +students discuss in small groups and + + align:start position:0% +students discuss in small groups and + + + align:start position:0% +students discuss in small groups and +then kind of bring the classroom back + + align:start position:0% +then kind of bring the classroom back + + + align:start position:0% +then kind of bring the classroom back +together for a wide discussion and there + + align:start position:0% +together for a wide discussion and there + + + align:start position:0% +together for a wide discussion and there +you know students are in their groups + + align:start position:0% +you know students are in their groups + + + align:start position:0% +you know students are in their groups +they get a chance to kind of vet their + + align:start position:0% +they get a chance to kind of vet their + + + align:start position:0% +they get a chance to kind of vet their +ideas with their peers it's sort of hard + + align:start position:0% +ideas with their peers it's sort of hard + + + align:start position:0% +ideas with their peers it's sort of hard +if you're in a group of two or three to + + align:start position:0% +if you're in a group of two or three to + + + align:start position:0% +if you're in a group of two or three to +not participate you sort of have to say + + align:start position:0% +not participate you sort of have to say + + + align:start position:0% +not participate you sort of have to say +something so the get to vet their ideas + + align:start position:0% +something so the get to vet their ideas + + + align:start position:0% +something so the get to vet their ideas +with people they'll get some reassurance + + align:start position:0% +with people they'll get some reassurance + + + align:start position:0% +with people they'll get some reassurance +and you know in theory they're then more + + align:start position:0% +and you know in theory they're then more + + + align:start position:0% +and you know in theory they're then more +willing to bring that idea back to the + + align:start position:0% +willing to bring that idea back to the + + + align:start position:0% +willing to bring that idea back to the +whole class you know that type of + + align:start position:0% +whole class you know that type of + + + align:start position:0% +whole class you know that type of +activity can also give you an relatively + + align:start position:0% +activity can also give you an relatively + + + align:start position:0% +activity can also give you an relatively +easy way to make sure one person doesn't + + align:start position:0% +easy way to make sure one person doesn't + + + align:start position:0% +easy way to make sure one person doesn't +dominate the discussion by saying okay + + align:start position:0% +dominate the discussion by saying okay + + + align:start position:0% +dominate the discussion by saying okay +you know I suppose you guys up into five + + align:start position:0% +you know I suppose you guys up into five + + + align:start position:0% +you know I suppose you guys up into five +groups and let's hear let's hear from + + align:start position:0% +groups and let's hear let's hear from + + + align:start position:0% +groups and let's hear let's hear from +each group no more work you know I + + align:start position:0% +each group no more work you know I + + + align:start position:0% +each group no more work you know I +thought if we did a lot of active + + align:start position:0% +thought if we did a lot of active + + + align:start position:0% +thought if we did a lot of active +learning it might keep the students + + align:start position:0% +learning it might keep the students + + + align:start position:0% +learning it might keep the students +engaged for longer right it'd help us + + align:start position:0% +engaged for longer right it'd help us + + + align:start position:0% +engaged for longer right it'd help us +avoid lecturing it helped us set this + + align:start position:0% +avoid lecturing it helped us set this + + + align:start position:0% +avoid lecturing it helped us set this +precedent that you come to recitation + + align:start position:0% +precedent that you come to recitation + + + align:start position:0% +precedent that you come to recitation +having read the paper we're not going to + + align:start position:0% +having read the paper we're not going to + + + align:start position:0% +having read the paper we're not going to +lecture for you all right so that's kind + + align:start position:0% +lecture for you all right so that's kind + + + align:start position:0% +lecture for you all right so that's kind +of where we're starting that's the + + align:start position:0% +of where we're starting that's the + + + align:start position:0% +of where we're starting that's the +baseline for this talk + + align:start position:0% +baseline for this talk + + + align:start position:0% +baseline for this talk +now my goal for all of you is that this + + align:start position:0% +now my goal for all of you is that this + + + align:start position:0% +now my goal for all of you is that this +talk is I hope exceedingly practical I'm + + align:start position:0% +talk is I hope exceedingly practical I'm + + + align:start position:0% +talk is I hope exceedingly practical I'm +gonna talk about some specific ways that + + align:start position:0% +gonna talk about some specific ways that + + + align:start position:0% +gonna talk about some specific ways that +I trained my staff to do this the types + + align:start position:0% +I trained my staff to do this the types + + + align:start position:0% +I trained my staff to do this the types +of active learning activities we do some + + align:start position:0% +of active learning activities we do some + + + align:start position:0% +of active learning activities we do some +lessons we've learned how we've + + align:start position:0% +lessons we've learned how we've + + + align:start position:0% +lessons we've learned how we've +evaluated our success I hope you'll be + + align:start position:0% +evaluated our success I hope you'll be + + + align:start position:0% +evaluated our success I hope you'll be +able to apply some of these ideas to + + align:start position:0% +able to apply some of these ideas to + + + align:start position:0% +able to apply some of these ideas to +your own classes if you want I do want + + align:start position:0% +your own classes if you want I do want + + + align:start position:0% +your own classes if you want I do want +to start though with a disclaimer and + + align:start position:0% +to start though with a disclaimer and + + + align:start position:0% +to start though with a disclaimer and +this is really a case study of how + + align:start position:0% +this is really a case study of how + + + align:start position:0% +this is really a case study of how +active learning has worked in o33 all + + align:start position:0% +active learning has worked in o33 all + + + align:start position:0% +active learning has worked in o33 all +right I'm not here to make claims that + + align:start position:0% +right I'm not here to make claims that + + + align:start position:0% +right I'm not here to make claims that +active learning is a solution to all of + + align:start position:0% +active learning is a solution to all of + + + align:start position:0% +active learning is a solution to all of +your teaching problems you know I think + + align:start position:0% +your teaching problems you know I think + + + align:start position:0% +your teaching problems you know I think +it's very good it's probably not the + + align:start position:0% +it's very good it's probably not the + + + align:start position:0% +it's very good it's probably not the +solution to everything + + align:start position:0% +solution to everything + + + align:start position:0% +solution to everything +nor my even you know I'm not even here + + align:start position:0% +nor my even you know I'm not even here + + + align:start position:0% +nor my even you know I'm not even here +to really evangelize it over any other + + align:start position:0% +to really evangelize it over any other + + + align:start position:0% +to really evangelize it over any other +particular pedagogical schemes I think + + align:start position:0% +particular pedagogical schemes I think + + + align:start position:0% +particular pedagogical schemes I think +it works well in two or three three I + + align:start position:0% +it works well in two or three three I + + + align:start position:0% +it works well in two or three three I +think we've done some really cool things + + align:start position:0% +think we've done some really cool things + + + align:start position:0% +think we've done some really cool things +I hope you're excited to hear about them + + align:start position:0% +I hope you're excited to hear about them + + + align:start position:0% +I hope you're excited to hear about them +so active learning as you've probably + + align:start position:0% +so active learning as you've probably + + + align:start position:0% +so active learning as you've probably +picked up at this point what I'm gonna + + align:start position:0% +picked up at this point what I'm gonna + + + align:start position:0% +picked up at this point what I'm gonna +talk about you know we're if infusing + + align:start position:0% +talk about you know we're if infusing + + + align:start position:0% +talk about you know we're if infusing +the recitations and author through with + + align:start position:0% +the recitations and author through with + + + align:start position:0% +the recitations and author through with +active learning and so that means that + + align:start position:0% +active learning and so that means that + + + align:start position:0% +active learning and so that means that +really it is my recitation instructors + + align:start position:0% +really it is my recitation instructors + + + align:start position:0% +really it is my recitation instructors +who are on the ground doing a lot of + + align:start position:0% +who are on the ground doing a lot of + + + align:start position:0% +who are on the ground doing a lot of +this and I will admit then when we were + + align:start position:0% +this and I will admit then when we were + + + align:start position:0% +this and I will admit then when we were +starting out I sort of thought you know + + align:start position:0% +starting out I sort of thought you know + + + align:start position:0% +starting out I sort of thought you know +I had this amazing idea to do active + + align:start position:0% +I had this amazing idea to do active + + + align:start position:0% +I had this amazing idea to do active +learning recitations and I was like well + + align:start position:0% +learning recitations and I was like well + + + align:start position:0% +learning recitations and I was like well +I am done I have solved the problem I + + align:start position:0% +I am done I have solved the problem I + + + align:start position:0% +I am done I have solved the problem I +just told my instructors to implement it + + align:start position:0% +just told my instructors to implement it + + + align:start position:0% +just told my instructors to implement it +it was like guys active learning it + + align:start position:0% +it was like guys active learning it + + + align:start position:0% +it was like guys active learning it +didn't work I was perplexed because you + + align:start position:0% +didn't work I was perplexed because you + + + align:start position:0% +didn't work I was perplexed because you +know I told my instructors correctly + + align:start position:0% +know I told my instructors correctly + + + align:start position:0% +know I told my instructors correctly +that these types of activities would + + align:start position:0% +that these types of activities would + + + align:start position:0% +that these types of activities would +help increase participation my + + align:start position:0% +help increase participation my + + + align:start position:0% +help increase participation my +instructors were the ones complaining + + align:start position:0% +instructors were the ones complaining + + + align:start position:0% +instructors were the ones complaining +about the lack of participation and so I + + align:start position:0% +about the lack of participation and so I + + + align:start position:0% +about the lack of participation and so I +just thought oh come on what's the + + align:start position:0% +just thought oh come on what's the + + + align:start position:0% +just thought oh come on what's the +problem well it turns out you cannot + + align:start position:0% +problem well it turns out you cannot + + + align:start position:0% +problem well it turns out you cannot +tell your instructors to do a thing that + + align:start position:0% +tell your instructors to do a thing that + + + align:start position:0% +tell your instructors to do a thing that +they've never done before and just have + + align:start position:0% +they've never done before and just have + + + align:start position:0% +they've never done before and just have +them magically do it in particular you + + align:start position:0% +them magically do it in particular you + + + align:start position:0% +them magically do it in particular you +can tell your instructors to + + align:start position:0% +can tell your instructors to + + + align:start position:0% +can tell your instructors to +fundamentally change the way they teach + + align:start position:0% +fundamentally change the way they teach + + + align:start position:0% +fundamentally change the way they teach +and magically have that happen I mean I + + align:start position:0% +and magically have that happen I mean I + + + align:start position:0% +and magically have that happen I mean I +would say you know it's difficult enough + + align:start position:0% +would say you know it's difficult enough + + + align:start position:0% +would say you know it's difficult enough +for us to change the way we teach much + + align:start position:0% +for us to change the way we teach much + + + align:start position:0% +for us to change the way we teach much +less to get other people to change the + + align:start position:0% +less to get other people to change the + + + align:start position:0% +less to get other people to change the +way they teach so the first part of my + + align:start position:0% +way they teach so the first part of my + + + align:start position:0% +way they teach so the first part of my +talk is changing the way other people + + align:start position:0% +talk is changing the way other people + + + align:start position:0% +talk is changing the way other people +teach in four easy steps all right so + + align:start position:0% +teach in four easy steps all right so + + + align:start position:0% +teach in four easy steps all right so +step one is get everyone on board so + + align:start position:0% +step one is get everyone on board so + + + align:start position:0% +step one is get everyone on board so +this is the first thing that I did last + + align:start position:0% +this is the first thing that I did last + + + align:start position:0% +this is the first thing that I did last +year in no.33 I will keep saying last + + align:start position:0% +year in no.33 I will keep saying last + + + align:start position:0% +year in no.33 I will keep saying last +semester but you can last year all right + + align:start position:0% +semester but you can last year all right + + + align:start position:0% +semester but you can last year all right +I presented active learning is our + + align:start position:0% +I presented active learning is our + + + align:start position:0% +I presented active learning is our +primary goal for the entire semester so + + align:start position:0% +primary goal for the entire semester so + + + align:start position:0% +primary goal for the entire semester so +we did not wait until the course got + + align:start position:0% +we did not wait until the course got + + + align:start position:0% +we did not wait until the course got +settled down to start doing it in fact + + align:start position:0% +settled down to start doing it in fact + + + align:start position:0% +settled down to start doing it in fact +our very first staff meeting which + + align:start position:0% +our very first staff meeting which + + + align:start position:0% +our very first staff meeting which +happens before the semester is has even + + align:start position:0% +happens before the semester is has even + + + align:start position:0% +happens before the semester is has even +begun was about active learning we had + + align:start position:0% +begun was about active learning we had + + + align:start position:0% +begun was about active learning we had +everyone on the staff there so me all of + + align:start position:0% +everyone on the staff there so me all of + + + align:start position:0% +everyone on the staff there so me all of +my recitation instructors all of my TAS + + align:start position:0% +my recitation instructors all of my TAS + + + align:start position:0% +my recitation instructors all of my TAS +all of the communication instructors + + align:start position:0% +all of the communication instructors + + + align:start position:0% +all of the communication instructors +this is about 30-some people here and we + + align:start position:0% +this is about 30-some people here and we + + + align:start position:0% +this is about 30-some people here and we +talked about active learning we talked + + align:start position:0% +talked about active learning we talked + + + align:start position:0% +talked about active learning we talked +about why it's a good idea the evidence + + align:start position:0% +about why it's a good idea the evidence + + + align:start position:0% +about why it's a good idea the evidence +that it's a good idea evidence that it + + align:start position:0% +that it's a good idea evidence that it + + + align:start position:0% +that it's a good idea evidence that it +is better than lecturing we talked about + + align:start position:0% +is better than lecturing we talked about + + + align:start position:0% +is better than lecturing we talked about +why running the recitations in this way + + align:start position:0% +why running the recitations in this way + + + align:start position:0% +why running the recitations in this way +would support the other learning + + align:start position:0% +would support the other learning + + + align:start position:0% +would support the other learning +objectives no.33 + + align:start position:0% +objectives no.33 + + + align:start position:0% +objectives no.33 +in particular the objective of getting + + align:start position:0% +in particular the objective of getting + + + align:start position:0% +in particular the objective of getting +students to design their own systems and + + align:start position:0% +students to design their own systems and + + + align:start position:0% +students to design their own systems and +evaluate their own trade-offs I + + align:start position:0% +evaluate their own trade-offs I + + + align:start position:0% +evaluate their own trade-offs I +explained to my instructors that there + + align:start position:0% +explained to my instructors that there + + + align:start position:0% +explained to my instructors that there +would be extensive support for this and + + align:start position:0% +would be extensive support for this and + + + align:start position:0% +would be extensive support for this and +that we would you know we'd be checking + + align:start position:0% +that we would you know we'd be checking + + + align:start position:0% +that we would you know we'd be checking +in throughout the semester to make sure + + align:start position:0% +in throughout the semester to make sure + + + align:start position:0% +in throughout the semester to make sure +this was really working for them and + + align:start position:0% +this was really working for them and + + + align:start position:0% +this was really working for them and +working for the students now I did + + align:start position:0% +working for the students now I did + + + align:start position:0% +working for the students now I did +expect some pushback on this in this + + align:start position:0% +expect some pushback on this in this + + + align:start position:0% +expect some pushback on this in this +meeting + + align:start position:0% +meeting + + + align:start position:0% +meeting +I know partly I am asking a lot of my + + align:start position:0% +I know partly I am asking a lot of my + + + align:start position:0% +I know partly I am asking a lot of my +staff here and also you know I am a + + align:start position:0% +staff here and also you know I am a + + + align:start position:0% +staff here and also you know I am a +lecturer in charge of a lot of faculty + + align:start position:0% +lecturer in charge of a lot of faculty + + + align:start position:0% +lecturer in charge of a lot of faculty +who have been here for a very long time + + align:start position:0% +who have been here for a very long time + + + align:start position:0% +who have been here for a very long time +so I was not quite sure how this would + + align:start position:0% +so I was not quite sure how this would + + + align:start position:0% +so I was not quite sure how this would +go I do not know if my staff knew about + + align:start position:0% +go I do not know if my staff knew about + + + align:start position:0% +go I do not know if my staff knew about +this I actually went so far in preparing + + align:start position:0% +this I actually went so far in preparing + + + align:start position:0% +this I actually went so far in preparing +for this staff meeting to not only sort + + align:start position:0% +for this staff meeting to not only sort + + + align:start position:0% +for this staff meeting to not only sort +of write out all of my objectives and + + align:start position:0% +of write out all of my objectives and + + + align:start position:0% +of write out all of my objectives and +why active learning was a good idea but + + align:start position:0% +why active learning was a good idea but + + + align:start position:0% +why active learning was a good idea but +to rein my own rebuttal to myself and + + align:start position:0% +to rein my own rebuttal to myself and + + + align:start position:0% +to rein my own rebuttal to myself and +then rebut that so I sort of had okay + + align:start position:0% +then rebut that so I sort of had okay + + + align:start position:0% +then rebut that so I sort of had okay +well if I was if I didn't want to do + + align:start position:0% +well if I was if I didn't want to do + + + align:start position:0% +well if I was if I didn't want to do +this you know I'd be asking I don't + + align:start position:0% +this you know I'd be asking I don't + + + align:start position:0% +this you know I'd be asking I don't +think active learning is a good idea I + + align:start position:0% +think active learning is a good idea I + + + align:start position:0% +think active learning is a good idea I +don't think this is gonna work and I had + + align:start position:0% +don't think this is gonna work and I had + + + align:start position:0% +don't think this is gonna work and I had +prepared answers for all of these + + align:start position:0% +prepared answers for all of these + + + align:start position:0% +prepared answers for all of these +questions I was lucky I looked at the + + align:start position:0% +questions I was lucky I looked at the + + + align:start position:0% +questions I was lucky I looked at the +notes for that meeting to prepare for + + align:start position:0% +notes for that meeting to prepare for + + + align:start position:0% +notes for that meeting to prepare for +this and there it really went on for + + align:start position:0% +this and there it really went on for + + + align:start position:0% +this and there it really went on for +quite a while I did not actually get + + align:start position:0% +quite a while I did not actually get + + + align:start position:0% +quite a while I did not actually get +that much pushback here you know because + + align:start position:0% +that much pushback here you know because + + + align:start position:0% +that much pushback here you know because +my staff is amazing but also I talked to + + align:start position:0% +my staff is amazing but also I talked to + + + align:start position:0% +my staff is amazing but also I talked to +a few of my instructors ahead of time + + align:start position:0% +a few of my instructors ahead of time + + + align:start position:0% +a few of my instructors ahead of time +about this people who had been with the + + align:start position:0% +about this people who had been with the + + + align:start position:0% +about this people who had been with the +class for a while who I knew would be a + + align:start position:0% +class for a while who I knew would be a + + + align:start position:0% +class for a while who I knew would be a +little maybe a little bit more game for + + align:start position:0% +little maybe a little bit more game for + + + align:start position:0% +little maybe a little bit more game for +this idea I kind of got them on board + + align:start position:0% +this idea I kind of got them on board + + + align:start position:0% +this idea I kind of got them on board +first + + align:start position:0% +first + + + align:start position:0% +first +I also appealed to everyone's you know + + align:start position:0% +I also appealed to everyone's you know + + + align:start position:0% +I also appealed to everyone's you know +scientific nature right explaining that + + align:start position:0% +scientific nature right explaining that + + + align:start position:0% +scientific nature right explaining that +this was somewhat of a research project + + align:start position:0% +this was somewhat of a research project + + + align:start position:0% +this was somewhat of a research project +which which was true right I did want to + + align:start position:0% +which which was true right I did want to + + + align:start position:0% +which which was true right I did want to +know would this work in o33 I was + + align:start position:0% +know would this work in o33 I was + + + align:start position:0% +know would this work in o33 I was +heavily biased towards the fact that I + + align:start position:0% +heavily biased towards the fact that I + + + align:start position:0% +heavily biased towards the fact that I +thought it was going to work but well + + align:start position:0% +thought it was going to work but well + + + align:start position:0% +thought it was going to work but well +you know we had methods to evaluate this + + align:start position:0% +you know we had methods to evaluate this + + + align:start position:0% +you know we had methods to evaluate this +throughout the semester I mean you know + + align:start position:0% +throughout the semester I mean you know + + + align:start position:0% +throughout the semester I mean you know +I told him if this goes horribly we + + align:start position:0% +I told him if this goes horribly we + + + align:start position:0% +I told him if this goes horribly we +won't keep doing it right I'm not gonna + + align:start position:0% +won't keep doing it right I'm not gonna + + + align:start position:0% +won't keep doing it right I'm not gonna +burning you with this and you know I + + align:start position:0% +burning you with this and you know I + + + align:start position:0% +burning you with this and you know I +enthusiatic enthusiastically mandated + + align:start position:0% +enthusiatic enthusiastically mandated + + + align:start position:0% +enthusiatic enthusiastically mandated +that this is what we were trying for + + align:start position:0% +that this is what we were trying for + + + align:start position:0% +that this is what we were trying for +this semester in previous semesters I + + align:start position:0% +this semester in previous semesters I + + + align:start position:0% +this semester in previous semesters I +had suggested some of these ideas + + align:start position:0% +had suggested some of these ideas + + + align:start position:0% +had suggested some of these ideas +encouraged my staff to try it that + + align:start position:0% +encouraged my staff to try it that + + + align:start position:0% +encouraged my staff to try it that +really wasn't enough and so you know on + + align:start position:0% +really wasn't enough and so you know on + + + align:start position:0% +really wasn't enough and so you know on +the one hand get everyone on board well + + align:start position:0% +the one hand get everyone on board well + + + align:start position:0% +the one hand get everyone on board well +there was one staff meeting but I would + + align:start position:0% +there was one staff meeting but I would + + + align:start position:0% +there was one staff meeting but I would +say it was it was really tempting for me + + align:start position:0% +say it was it was really tempting for me + + + align:start position:0% +say it was it was really tempting for me +to not have that staff meeting so soon + + align:start position:0% +to not have that staff meeting so soon + + + align:start position:0% +to not have that staff meeting so soon +Oh 33 is such a big class it has so many + + align:start position:0% +Oh 33 is such a big class it has so many + + + align:start position:0% +Oh 33 is such a big class it has so many +people involved we are it feels like + + align:start position:0% +people involved we are it feels like + + + align:start position:0% +people involved we are it feels like +we're just scrambling to get the + + align:start position:0% +we're just scrambling to get the + + + align:start position:0% +we're just scrambling to get the +logistics worked out in the first week + + align:start position:0% +logistics worked out in the first week + + + align:start position:0% +logistics worked out in the first week +or two even for us assigning our + + align:start position:0% +or two even for us assigning our + + + align:start position:0% +or two even for us assigning our +students to sections is this whole thing + + align:start position:0% +students to sections is this whole thing + + + align:start position:0% +students to sections is this whole thing +but doing this really set the tone for + + align:start position:0% +but doing this really set the tone for + + + align:start position:0% +but doing this really set the tone for +the whole semester I was kind of + + align:start position:0% +the whole semester I was kind of + + + align:start position:0% +the whole semester I was kind of +surprised at how helpful this one's this + + align:start position:0% +surprised at how helpful this one's this + + + align:start position:0% +surprised at how helpful this one's this +was everybody knew that active learning + + align:start position:0% +was everybody knew that active learning + + + align:start position:0% +was everybody knew that active learning +was important even the people who + + align:start position:0% +was important even the people who + + + align:start position:0% +was important even the people who +weren't the recitation instructors right + + align:start position:0% +weren't the recitation instructors right + + + align:start position:0% +weren't the recitation instructors right +all the TAS all the communications + + align:start position:0% +all the TAS all the communications + + + align:start position:0% +all the TAS all the communications +instructors they knew that it wasn't + + align:start position:0% +instructors they knew that it wasn't + + + align:start position:0% +instructors they knew that it wasn't +optional it was our primary goal of the + + align:start position:0% +optional it was our primary goal of the + + + align:start position:0% +optional it was our primary goal of the +semester any other changes that we made + + align:start position:0% +semester any other changes that we made + + + align:start position:0% +semester any other changes that we made +in the class were largely going to be in + + align:start position:0% +in the class were largely going to be in + + + align:start position:0% +in the class were largely going to be in +support of this goal all right so step + + align:start position:0% +support of this goal all right so step + + + align:start position:0% +support of this goal all right so step +one get everybody on board with your + + align:start position:0% +one get everybody on board with your + + + align:start position:0% +one get everybody on board with your +mission + + align:start position:0% +mission + + + align:start position:0% +mission +step two is do a lot of work all right + + align:start position:0% +step two is do a lot of work all right + + + align:start position:0% +step two is do a lot of work all right +do a lot of planning so step one was + + align:start position:0% +do a lot of planning so step one was + + + align:start position:0% +do a lot of planning so step one was +kind of our first staff meeting step two + + align:start position:0% +kind of our first staff meeting step two + + + align:start position:0% +kind of our first staff meeting step two +what's happening in our second staff + + align:start position:0% +what's happening in our second staff + + + align:start position:0% +what's happening in our second staff +meeting so one of the things that we did + + align:start position:0% +meeting so one of the things that we did + + + align:start position:0% +meeting so one of the things that we did +is we talked about a pretty one own list + + align:start position:0% +is we talked about a pretty one own list + + + align:start position:0% +is we talked about a pretty one own list +of it's something like 278 different + + align:start position:0% +of it's something like 278 different + + + align:start position:0% +of it's something like 278 different +active learning activities I knew it was + + align:start position:0% +active learning activities I knew it was + + + align:start position:0% +active learning activities I knew it was +a lot to ask + + align:start position:0% +a lot to ask + + + align:start position:0% +a lot to ask +really anyone to read through all 278 + + align:start position:0% +really anyone to read through all 278 + + + align:start position:0% +really anyone to read through all 278 +active learning activities and so you + + align:start position:0% +active learning activities and so you + + + align:start position:0% +active learning activities and so you +know I annotated this list and we kind + + align:start position:0% +know I annotated this list and we kind + + + align:start position:0% +know I annotated this list and we kind +of discussed the highlights in the in + + align:start position:0% +of discussed the highlights in the in + + + align:start position:0% +of discussed the highlights in the in +the staff meeting I am gonna go into + + align:start position:0% +the staff meeting I am gonna go into + + + align:start position:0% +the staff meeting I am gonna go into +detail in the second part of this class + + align:start position:0% +detail in the second part of this class + + + align:start position:0% +detail in the second part of this class +about some of the specific activities we + + align:start position:0% +about some of the specific activities we + + + align:start position:0% +about some of the specific activities we +do in Oh 3-3 but I'll give you some + + align:start position:0% +do in Oh 3-3 but I'll give you some + + + align:start position:0% +do in Oh 3-3 but I'll give you some +examples from this list just for + + align:start position:0% +examples from this list just for + + + align:start position:0% +examples from this list just for +concreteness so one of them which I + + align:start position:0% +concreteness so one of them which I + + + align:start position:0% +concreteness so one of them which I +really like to do + + align:start position:0% +really like to do + + + align:start position:0% +really like to do +lecture actually is they all have funny + + align:start position:0% +lecture actually is they all have funny + + + align:start position:0% +lecture actually is they all have funny +names okay so fingers on chest so this + + align:start position:0% +names okay so fingers on chest so this + + + align:start position:0% +names okay so fingers on chest so this +is having students vote on a + + align:start position:0% +is having students vote on a + + + align:start position:0% +is having students vote on a +multiple-choice question but using like + + align:start position:0% +multiple-choice question but using like + + + align:start position:0% +multiple-choice question but using like +fingers on their chest so option one + + align:start position:0% +fingers on their chest so option one + + + align:start position:0% +fingers on their chest so option one +option two option three and that way you + + align:start position:0% +option two option three and that way you + + + align:start position:0% +option two option three and that way you +know you can't the students can't see + + align:start position:0% +know you can't the students can't see + + + align:start position:0% +know you can't the students can't see +what other people are voting really + + align:start position:0% +what other people are voting really + + + align:start position:0% +what other people are voting really +they're not quite like Oh everybody else + + align:start position:0% +they're not quite like Oh everybody else + + + align:start position:0% +they're not quite like Oh everybody else +is voting for one I can't really see so + + align:start position:0% +is voting for one I can't really see so + + + align:start position:0% +is voting for one I can't really see so +they're they tend to be more truthful a + + align:start position:0% +they're they tend to be more truthful a + + + align:start position:0% +they're they tend to be more truthful a +lot of times in lecture is M just do + + align:start position:0% +lot of times in lecture is M just do + + + align:start position:0% +lot of times in lecture is M just do +they feel good about something or bad + + align:start position:0% +they feel good about something or bad + + + align:start position:0% +they feel good about something or bad +about something another one a fairly + + align:start position:0% +about something another one a fairly + + + align:start position:0% +about something another one a fairly +common one think-pair-share so posing a + + align:start position:0% +common one think-pair-share so posing a + + + align:start position:0% +common one think-pair-share so posing a +question to the class asking students to + + align:start position:0% +question to the class asking students to + + + align:start position:0% +question to the class asking students to +think about it then to share their ideas + + align:start position:0% +think about it then to share their ideas + + + align:start position:0% +think about it then to share their ideas +with a partner but and then maybe go and + + align:start position:0% +with a partner but and then maybe go and + + + align:start position:0% +with a partner but and then maybe go and +address the larger class and then a + + align:start position:0% +address the larger class and then a + + + align:start position:0% +address the larger class and then a +third one which I like just because it + + align:start position:0% +third one which I like just because it + + + align:start position:0% +third one which I like just because it +has a nice name the name for it is human + + align:start position:0% +has a nice name the name for it is human + + + align:start position:0% +has a nice name the name for it is human +tableau and so this is having groups + + align:start position:0% +tableau and so this is having groups + + + align:start position:0% +tableau and so this is having groups +create living scenes which relate to the + + align:start position:0% +create living scenes which relate to the + + + align:start position:0% +create living scenes which relate to the +classroom concepts or discussion alright + + align:start position:0% +classroom concepts or discussion alright + + + align:start position:0% +classroom concepts or discussion alright +so that one's a little bit more out + + align:start position:0% +so that one's a little bit more out + + + align:start position:0% +so that one's a little bit more out +there but and these are the types of + + align:start position:0% +there but and these are the types of + + + align:start position:0% +there but and these are the types of +activities we're thinking about and you + + align:start position:0% +activities we're thinking about and you + + + align:start position:0% +activities we're thinking about and you +know of course we went through this list + + align:start position:0% +know of course we went through this list + + + align:start position:0% +know of course we went through this list +we looked at a whole bunch of activities + + align:start position:0% +we looked at a whole bunch of activities + + + align:start position:0% +we looked at a whole bunch of activities +we're not going to end up using all of + + align:start position:0% +we're not going to end up using all of + + + align:start position:0% +we're not going to end up using all of +them in o33 but going through this list + + align:start position:0% +them in o33 but going through this list + + + align:start position:0% +them in o33 but going through this list +it was a really good exercise for all of + + align:start position:0% +it was a really good exercise for all of + + + align:start position:0% +it was a really good exercise for all of +us it gave everyone a much better sense + + align:start position:0% +us it gave everyone a much better sense + + + align:start position:0% +us it gave everyone a much better sense +of what is active learning or what can + + align:start position:0% +of what is active learning or what can + + + align:start position:0% +of what is active learning or what can +active learning be but you know even + + align:start position:0% +active learning be but you know even + + + align:start position:0% +active learning be but you know even +kind of armed with that list it's still + + align:start position:0% +kind of armed with that list it's still + + + align:start position:0% +kind of armed with that list it's still +a lot to tell your instructors here's + + align:start position:0% +a lot to tell your instructors here's + + + align:start position:0% +a lot to tell your instructors here's +your two hundred seventy eight + + align:start position:0% +your two hundred seventy eight + + + align:start position:0% +your two hundred seventy eight +activities + + align:start position:0% +activities + + + align:start position:0% +activities +now go now do active learning so in + + align:start position:0% +now go now do active learning so in + + + align:start position:0% +now go now do active learning so in +addition to this I pre planned a lot of + + align:start position:0% +addition to this I pre planned a lot of + + + align:start position:0% +addition to this I pre planned a lot of +active learning at techniques into each + + align:start position:0% +active learning at techniques into each + + + align:start position:0% +active learning at techniques into each +recitation so normally before active + + align:start position:0% +recitation so normally before active + + + align:start position:0% +recitation so normally before active +learning the way that I would plan + + align:start position:0% +learning the way that I would plan + + + align:start position:0% +learning the way that I would plan +recitations was strictly just for + + align:start position:0% +recitations was strictly just for + + + align:start position:0% +recitations was strictly just for +technical content I would give my + + align:start position:0% +technical content I would give my + + + align:start position:0% +technical content I would give my +instructors a handful of major technical + + align:start position:0% +instructors a handful of major technical + + + align:start position:0% +instructors a handful of major technical +issues they needed to hit on it helps + + align:start position:0% +issues they needed to hit on it helps + + + align:start position:0% +issues they needed to hit on it helps +keep her recitations somewhat uniform so + + align:start position:0% +keep her recitations somewhat uniform so + + + align:start position:0% +keep her recitations somewhat uniform so +that we can be fair on exams we do test + + align:start position:0% +that we can be fair on exams we do test + + + align:start position:0% +that we can be fair on exams we do test +the technical material on exams in this + + align:start position:0% +the technical material on exams in this + + + align:start position:0% +the technical material on exams in this +class beyond that though my instructors + + align:start position:0% +class beyond that though my instructors + + + align:start position:0% +class beyond that though my instructors +have a lot of leeway to teach these + + align:start position:0% +have a lot of leeway to teach these + + + align:start position:0% +have a lot of leeway to teach these +topics however they want a lot of legal + + align:start position:0% +topics however they want a lot of legal + + + align:start position:0% +topics however they want a lot of legal +on how they teach in general I had never + + align:start position:0% +on how they teach in general I had never + + + align:start position:0% +on how they teach in general I had never +before tried to steer them in a + + align:start position:0% +before tried to steer them in a + + + align:start position:0% +before tried to steer them in a +particular direction but now in addition + + align:start position:0% +particular direction but now in addition + + + align:start position:0% +particular direction but now in addition +to that technical content what I would + + align:start position:0% +to that technical content what I would + + + align:start position:0% +to that technical content what I would +do is I would put oh you know two or + + align:start position:0% +do is I would put oh you know two or + + + align:start position:0% +do is I would put oh you know two or +three active learning activities or + + align:start position:0% +three active learning activities or + + + align:start position:0% +three active learning activities or +techniques into each + + align:start position:0% +techniques into each + + + align:start position:0% +techniques into each +rotation so things like pointing out + + align:start position:0% +rotation so things like pointing out + + + align:start position:0% +rotation so things like pointing out +places where they could have students + + align:start position:0% +places where they could have students + + + align:start position:0% +places where they could have students +break into groups and think about a + + align:start position:0% +break into groups and think about a + + + align:start position:0% +break into groups and think about a +particular question pointing out places + + align:start position:0% +particular question pointing out places + + + align:start position:0% +particular question pointing out places +where they could hold a debate in the + + align:start position:0% +where they could hold a debate in the + + + align:start position:0% +where they could hold a debate in the +class right and again I'm going to talk + + align:start position:0% +class right and again I'm going to talk + + + align:start position:0% +class right and again I'm going to talk +about these specific activities we do in + + align:start position:0% +about these specific activities we do in + + + align:start position:0% +about these specific activities we do in +the second part of this talk but + + align:start position:0% +the second part of this talk but + + + align:start position:0% +the second part of this talk but +planning activities in this way meant + + align:start position:0% +planning activities in this way meant + + + align:start position:0% +planning activities in this way meant +that you know my sergers had a lot of + + align:start position:0% +that you know my sergers had a lot of + + + align:start position:0% +that you know my sergers had a lot of +ideas of how they can make this work in + + align:start position:0% +ideas of how they can make this work in + + + align:start position:0% +ideas of how they can make this work in +their sections giving them multiple + + align:start position:0% +their sections giving them multiple + + + align:start position:0% +their sections giving them multiple +ideas and multiple types of ideas really + + align:start position:0% +ideas and multiple types of ideas really + + + align:start position:0% +ideas and multiple types of ideas really +meant that they could pick the ones that + + align:start position:0% +meant that they could pick the ones that + + + align:start position:0% +meant that they could pick the ones that +they were the most comfortable with + + align:start position:0% +they were the most comfortable with + + + align:start position:0% +they were the most comfortable with +right so instead of saying to hey here's + + align:start position:0% +right so instead of saying to hey here's + + + align:start position:0% +right so instead of saying to hey here's +this really really out-there idea + + align:start position:0% +this really really out-there idea + + + align:start position:0% +this really really out-there idea +everybody go go try it here some of them + + align:start position:0% +everybody go go try it here some of them + + + align:start position:0% +everybody go go try it here some of them +might try more some of the more extreme + + align:start position:0% +might try more some of the more extreme + + + align:start position:0% +might try more some of the more extreme +ones but everybody could kind of find + + align:start position:0% +ones but everybody could kind of find + + + align:start position:0% +ones but everybody could kind of find +something that they were comfortable + + align:start position:0% +something that they were comfortable + + + align:start position:0% +something that they were comfortable +with so get everybody on board plan + + align:start position:0% +with so get everybody on board plan + + + align:start position:0% +with so get everybody on board plan +things and the next thing that I did was + + align:start position:0% +things and the next thing that I did was + + + align:start position:0% +things and the next thing that I did was +you know support my staff as individuals + + align:start position:0% +you know support my staff as individuals + + + align:start position:0% +you know support my staff as individuals +so I didn't just plan these activities + + align:start position:0% +so I didn't just plan these activities + + + align:start position:0% +so I didn't just plan these activities +and set the staff three I actually + + align:start position:0% +and set the staff three I actually + + + align:start position:0% +and set the staff three I actually +observed them throughout the semester + + align:start position:0% +observed them throughout the semester + + + align:start position:0% +observed them throughout the semester +and I made sure to stress that it wasn't + + align:start position:0% +and I made sure to stress that it wasn't + + + align:start position:0% +and I made sure to stress that it wasn't +any sort of evaluation I was not there + + align:start position:0% +any sort of evaluation I was not there + + + align:start position:0% +any sort of evaluation I was not there +to say oh boy Karen this is really this + + align:start position:0% +to say oh boy Karen this is really this + + + align:start position:0% +to say oh boy Karen this is really this +is really not working out I was just + + align:start position:0% +is really not working out I was just + + + align:start position:0% +is really not working out I was just +there to see what was working and what + + align:start position:0% +there to see what was working and what + + + align:start position:0% +there to see what was working and what +wasn't so that we could all iterate on + + align:start position:0% +wasn't so that we could all iterate on + + + align:start position:0% +wasn't so that we could all iterate on +these things in practice this was great + + align:start position:0% +these things in practice this was great + + + align:start position:0% +these things in practice this was great +I of course found way more good things + + align:start position:0% +I of course found way more good things + + + align:start position:0% +I of course found way more good things +in doing this than anything problematic + + align:start position:0% +in doing this than anything problematic + + + align:start position:0% +in doing this than anything problematic +most of my feedback to my instructors + + align:start position:0% +most of my feedback to my instructors + + + align:start position:0% +most of my feedback to my instructors +was hey you did this really awesome + + align:start position:0% +was hey you did this really awesome + + + align:start position:0% +was hey you did this really awesome +thing you should do more of that and can + + align:start position:0% +thing you should do more of that and can + + + align:start position:0% +thing you should do more of that and can +we share it with everybody else right so + + align:start position:0% +we share it with everybody else right so + + + align:start position:0% +we share it with everybody else right so +I really you know in the end kind of + + align:start position:0% +I really you know in the end kind of + + + align:start position:0% +I really you know in the end kind of +thought of myself more as a cheerleader + + align:start position:0% +thought of myself more as a cheerleader + + + align:start position:0% +thought of myself more as a cheerleader +for them and what they were doing then + + align:start position:0% +for them and what they were doing then + + + align:start position:0% +for them and what they were doing then +someone who was coming in and really + + align:start position:0% +someone who was coming in and really + + + align:start position:0% +someone who was coming in and really +critiquing anything you know I also got + + align:start position:0% +critiquing anything you know I also got + + + align:start position:0% +critiquing anything you know I also got +a lot of great ideas from them both in + + align:start position:0% +a lot of great ideas from them both in + + + align:start position:0% +a lot of great ideas from them both in +how to present certain technical content + + align:start position:0% +how to present certain technical content + + + align:start position:0% +how to present certain technical content +and twists on some of the active + + align:start position:0% +and twists on some of the active + + + align:start position:0% +and twists on some of the active +learning techniques that I had suggested + + align:start position:0% +learning techniques that I had suggested + + + align:start position:0% +learning techniques that I had suggested +so related to that you know I'm + + align:start position:0% +so related to that you know I'm + + + align:start position:0% +so related to that you know I'm +observing them as individuals but we + + align:start position:0% +observing them as individuals but we + + + align:start position:0% +observing them as individuals but we +would also talk a lot as a group about + + align:start position:0% +would also talk a lot as a group about + + + align:start position:0% +would also talk a lot as a group about +how this was going every staff meeting + + align:start position:0% +how this was going every staff meeting + + + align:start position:0% +how this was going every staff meeting +we take time to talk about you know what + + align:start position:0% +we take time to talk about you know what + + + align:start position:0% +we take time to talk about you know what +went well the previous week our + + align:start position:0% +went well the previous week our + + + align:start position:0% +went well the previous week our +instructors would share active learning + + align:start position:0% +instructors would share active learning + + + align:start position:0% +instructors would share active learning +ideas that they tried report on how they + + align:start position:0% +ideas that they tried report on how they + + + align:start position:0% +ideas that they tried report on how they +went this was really nice it got you + + align:start position:0% +went this was really nice it got you + + + align:start position:0% +went this was really nice it got you +know some of my more hesitant + + align:start position:0% +know some of my more hesitant + + + align:start position:0% +know some of my more hesitant +instructors kind of on board with this + + align:start position:0% +instructors kind of on board with this + + + align:start position:0% +instructors kind of on board with this +to say like oh + + align:start position:0% +to say like oh + + + align:start position:0% +to say like oh +well that person tried it and it seemed + + align:start position:0% +well that person tried it and it seemed + + + align:start position:0% +well that person tried it and it seemed +like it went really well maybe I'll try + + align:start position:0% +like it went really well maybe I'll try + + + align:start position:0% +like it went really well maybe I'll try +that next time and you know of course + + align:start position:0% +that next time and you know of course + + + align:start position:0% +that next time and you know of course +the thing that turned out to be so great + + align:start position:0% +the thing that turned out to be so great + + + align:start position:0% +the thing that turned out to be so great +about this is that all of my instructors + + align:start position:0% +about this is that all of my instructors + + + align:start position:0% +about this is that all of my instructors +have these amazing ideas on how to teach + + align:start position:0% +have these amazing ideas on how to teach + + + align:start position:0% +have these amazing ideas on how to teach +certain things but to them it doesn't + + align:start position:0% +certain things but to them it doesn't + + + align:start position:0% +certain things but to them it doesn't +you know it doesn't seem special like + + align:start position:0% +you know it doesn't seem special like + + + align:start position:0% +you know it doesn't seem special like +this is just always the way I've taught + + align:start position:0% +this is just always the way I've taught + + + align:start position:0% +this is just always the way I've taught +operating systems and so now we have + + align:start position:0% +operating systems and so now we have + + + align:start position:0% +operating systems and so now we have +this space where we're getting to share + + align:start position:0% +this space where we're getting to share + + + align:start position:0% +this space where we're getting to share +all of these ideas a lot of them relate + + align:start position:0% +all of these ideas a lot of them relate + + + align:start position:0% +all of these ideas a lot of them relate +to how our active learning has gone but + + align:start position:0% +to how our active learning has gone but + + + align:start position:0% +to how our active learning has gone but +sometimes it's just hey I you know I + + align:start position:0% +sometimes it's just hey I you know I + + + align:start position:0% +sometimes it's just hey I you know I +chop this paper this really cool way it + + align:start position:0% +chop this paper this really cool way it + + + align:start position:0% +chop this paper this really cool way it +is also you know the fact that we've now + + align:start position:0% +is also you know the fact that we've now + + + align:start position:0% +is also you know the fact that we've now +kind of fostered this space for + + align:start position:0% +kind of fostered this space for + + + align:start position:0% +kind of fostered this space for +discussion at every staff meeting + + align:start position:0% +discussion at every staff meeting + + + align:start position:0% +discussion at every staff meeting +everybody is pretty willing to bring up + + align:start position:0% +everybody is pretty willing to bring up + + + align:start position:0% +everybody is pretty willing to bring up +things that aren't going as well so + + align:start position:0% +things that aren't going as well so + + + align:start position:0% +things that aren't going as well so +maybe come in and say hey I tried this + + align:start position:0% +maybe come in and say hey I tried this + + + align:start position:0% +maybe come in and say hey I tried this +active learning thing and it did not + + align:start position:0% +active learning thing and it did not + + + align:start position:0% +active learning thing and it did not +work at all you know what do you all + + align:start position:0% +work at all you know what do you all + + + align:start position:0% +work at all you know what do you all +think is there something I could have + + align:start position:0% +think is there something I could have + + + align:start position:0% +think is there something I could have +done differently does just is this just + + align:start position:0% +done differently does just is this just + + + align:start position:0% +done differently does just is this just +not something that will work for our + + align:start position:0% +not something that will work for our + + + align:start position:0% +not something that will work for our +class and so that has been really really + + align:start position:0% +class and so that has been really really + + + align:start position:0% +class and so that has been really really +great having this this space for my + + align:start position:0% +great having this this space for my + + + align:start position:0% +great having this this space for my +staff to kind of reflect on this and not + + align:start position:0% +staff to kind of reflect on this and not + + + align:start position:0% +staff to kind of reflect on this and not +feel judged in any way so this is the + + align:start position:0% +feel judged in any way so this is the + + + align:start position:0% +feel judged in any way so this is the +first part of getting active learning to + + align:start position:0% +first part of getting active learning to + + + align:start position:0% +first part of getting active learning to +work in o33 + + align:start position:0% +work in o33 + + + align:start position:0% +work in o33 +which was a lot of staff training but + + align:start position:0% +which was a lot of staff training but + + + align:start position:0% +which was a lot of staff training but +now the second part what do we actually + + align:start position:0% +now the second part what do we actually + + + align:start position:0% +now the second part what do we actually +do all right like what are these + + align:start position:0% +do all right like what are these + + + align:start position:0% +do all right like what are these +activities um I would like to give you + + align:start position:0% +activities um I would like to give you + + + align:start position:0% +activities um I would like to give you +some specific examples from oh three + + align:start position:0% +some specific examples from oh three + + + align:start position:0% +some specific examples from oh three +three but I will also you know I'll try + + align:start position:0% +three but I will also you know I'll try + + + align:start position:0% +three but I will also you know I'll try +to give you some general feedback as + + align:start position:0% +to give you some general feedback as + + + align:start position:0% +to give you some general feedback as +well I realize you probably won't be + + align:start position:0% +well I realize you probably won't be + + + align:start position:0% +well I realize you probably won't be +able to take the other three activities + + align:start position:0% +able to take the other three activities + + + align:start position:0% +able to take the other three activities +exactly into your classes so let me talk + + align:start position:0% +exactly into your classes so let me talk + + + align:start position:0% +exactly into your classes so let me talk +about some of the common things that we + + align:start position:0% +about some of the common things that we + + + align:start position:0% +about some of the common things that we +do so these are things that we've seen + + align:start position:0% +do so these are things that we've seen + + + align:start position:0% +do so these are things that we've seen +work really well in our classes so one + + align:start position:0% +work really well in our classes so one + + + align:start position:0% +work really well in our classes so one +of the most common types of active + + align:start position:0% +of the most common types of active + + + align:start position:0% +of the most common types of active +learning that we do is one I have + + align:start position:0% +learning that we do is one I have + + + align:start position:0% +learning that we do is one I have +already referenced a lot which is to + + align:start position:0% +already referenced a lot which is to + + + align:start position:0% +already referenced a lot which is to +sort of put students in small groups + + align:start position:0% +sort of put students in small groups + + + align:start position:0% +sort of put students in small groups +have them do something and then bring + + align:start position:0% +have them do something and then bring + + + align:start position:0% +have them do something and then bring +them back for a class-wide discussion so + + align:start position:0% +them back for a class-wide discussion so + + + align:start position:0% +them back for a class-wide discussion so +let me give you some really specific + + align:start position:0% +let me give you some really specific + + + align:start position:0% +let me give you some really specific +examples we have a recitation where we + + align:start position:0% +examples we have a recitation where we + + + align:start position:0% +examples we have a recitation where we +talk about content distribution networks + + align:start position:0% +talk about content distribution networks + + + align:start position:0% +talk about content distribution networks +the paper they read describes various + + align:start position:0% +the paper they read describes various + + + align:start position:0% +the paper they read describes various +goals of those networks so performance + + align:start position:0% +goals of those networks so performance + + + align:start position:0% +goals of those networks so performance +reliability scalability things like this + + align:start position:0% +reliability scalability things like this + + + align:start position:0% +reliability scalability things like this +what we'll do in that recitation is + + align:start position:0% +what we'll do in that recitation is + + + align:start position:0% +what we'll do in that recitation is +we'll divide the class + + align:start position:0% +we'll divide the class + + + align:start position:0% +we'll divide the class +up into groups and we'll have each group + + align:start position:0% +up into groups and we'll have each group + + + align:start position:0% +up into groups and we'll have each group +think about what aspects of the system + + align:start position:0% +think about what aspects of the system + + + align:start position:0% +think about what aspects of the system +support a particular goal alright so you + + align:start position:0% +support a particular goal alright so you + + + align:start position:0% +support a particular goal alright so you +all you think about performance you + + align:start position:0% +all you think about performance you + + + align:start position:0% +all you think about performance you +think about reliability you think about + + align:start position:0% +think about reliability you think about + + + align:start position:0% +think about reliability you think about +scalability and etc and then we'll bring + + align:start position:0% +scalability and etc and then we'll bring + + + align:start position:0% +scalability and etc and then we'll bring +the class back to a discussion once + + align:start position:0% +the class back to a discussion once + + + align:start position:0% +the class back to a discussion once +they've thought about that for a while + + align:start position:0% +they've thought about that for a while + + + align:start position:0% +they've thought about that for a while +another example when we talk about + + align:start position:0% +another example when we talk about + + + align:start position:0% +another example when we talk about +naming in the UNIX file system we start + + align:start position:0% +naming in the UNIX file system we start + + + align:start position:0% +naming in the UNIX file system we start +by asking them what things have names + + align:start position:0% +by asking them what things have names + + + align:start position:0% +by asking them what things have names +what things and UNIX have names and + + align:start position:0% +what things and UNIX have names and + + + align:start position:0% +what things and UNIX have names and +again we'll put them in groups we'll try + + align:start position:0% +again we'll put them in groups we'll try + + + align:start position:0% +again we'll put them in groups we'll try +to get every group to come up with as + + align:start position:0% +to get every group to come up with as + + + align:start position:0% +to get every group to come up with as +many things as possible because when we + + align:start position:0% +many things as possible because when we + + + align:start position:0% +many things as possible because when we +bring them back together we'll try to + + align:start position:0% +bring them back together we'll try to + + + align:start position:0% +bring them back together we'll try to +get a different thing from every group + + align:start position:0% +get a different thing from every group + + + align:start position:0% +get a different thing from every group +so you can't all just say files you have + + align:start position:0% +so you can't all just say files you have + + + align:start position:0% +so you can't all just say files you have +to say like files and directories and + + align:start position:0% +to say like files and directories and + + + align:start position:0% +to say like files and directories and +processes and there's a lot of things in + + align:start position:0% +processes and there's a lot of things in + + + align:start position:0% +processes and there's a lot of things in +UNIX that have names I'm not here to + + align:start position:0% +UNIX that have names I'm not here to + + + align:start position:0% +UNIX that have names I'm not here to +make you UNIX at experts all right and + + align:start position:0% +make you UNIX at experts all right and + + + align:start position:0% +make you UNIX at experts all right and +so you know in both of those examples + + align:start position:0% +so you know in both of those examples + + + align:start position:0% +so you know in both of those examples +like I said we'll bring the class back + + align:start position:0% +like I said we'll bring the class back + + + align:start position:0% +like I said we'll bring the class back +together for a discussion we'll try to + + align:start position:0% +together for a discussion we'll try to + + + align:start position:0% +together for a discussion we'll try to +have each group say something and as I + + align:start position:0% +have each group say something and as I + + + align:start position:0% +have each group say something and as I +said before what we've seen very clearly + + align:start position:0% +said before what we've seen very clearly + + + align:start position:0% +said before what we've seen very clearly +talking in these small groups beforehand + + align:start position:0% +talking in these small groups beforehand + + + align:start position:0% +talking in these small groups beforehand +really makes the Shire students a lot + + align:start position:0% +really makes the Shire students a lot + + + align:start position:0% +really makes the Shire students a lot +more confident right and asking each + + align:start position:0% +more confident right and asking each + + + align:start position:0% +more confident right and asking each +group to contribute to the discussion + + align:start position:0% +group to contribute to the discussion + + + align:start position:0% +group to contribute to the discussion +means that we don't end up with + + align:start position:0% +means that we don't end up with + + + align:start position:0% +means that we don't end up with +something that is dominated by like one + + align:start position:0% +something that is dominated by like one + + + align:start position:0% +something that is dominated by like one +or two groups it often will even be a + + align:start position:0% +or two groups it often will even be a + + + align:start position:0% +or two groups it often will even be a +little bit more relaxed about it we will + + align:start position:0% +little bit more relaxed about it we will + + + align:start position:0% +little bit more relaxed about it we will +just ask a big question you know some + + align:start position:0% +just ask a big question you know some + + + align:start position:0% +just ask a big question you know some +sort of thought question not just a you + + align:start position:0% +sort of thought question not just a you + + + align:start position:0% +sort of thought question not just a you +know tell me this fact from the paper + + align:start position:0% +know tell me this fact from the paper + + + align:start position:0% +know tell me this fact from the paper +well break them over the small groups + + align:start position:0% +well break them over the small groups + + + align:start position:0% +well break them over the small groups +have them think about it and come back + + align:start position:0% +have them think about it and come back + + + align:start position:0% +have them think about it and come back +together for discuss for a discussion + + align:start position:0% +together for discuss for a discussion + + + align:start position:0% +together for discuss for a discussion +you know it's nice it breaks up the + + align:start position:0% +you know it's nice it breaks up the + + + align:start position:0% +you know it's nice it breaks up the +recitation it gets them kind of talking + + align:start position:0% +recitation it gets them kind of talking + + + align:start position:0% +recitation it gets them kind of talking +and doing things um we occasionally will + + align:start position:0% +and doing things um we occasionally will + + + align:start position:0% +and doing things um we occasionally will +have our TAS teach in this class and you + + align:start position:0% +have our TAS teach in this class and you + + + align:start position:0% +have our TAS teach in this class and you +know we encourage them to use these + + align:start position:0% +know we encourage them to use these + + + align:start position:0% +know we encourage them to use these +techniques as well and one of them asked + + align:start position:0% +techniques as well and one of them asked + + + align:start position:0% +techniques as well and one of them asked +me a really good question that I + + align:start position:0% +me a really good question that I + + + align:start position:0% +me a really good question that I +realized I had never thought about she + + align:start position:0% +realized I had never thought about she + + + align:start position:0% +realized I had never thought about she +said what do I do when they're in groups + + align:start position:0% +said what do I do when they're in groups + + + align:start position:0% +said what do I do when they're in groups +like do I just stand there and stare at + + align:start position:0% +like do I just stand there and stare at + + + align:start position:0% +like do I just stand there and stare at +them like probably not that's probably + + align:start position:0% +them like probably not that's probably + + + align:start position:0% +them like probably not that's probably +not good so to tell you what we do how + + align:start position:0% +not good so to tell you what we do how + + + align:start position:0% +not good so to tell you what we do how +there are groups sometimes our + + align:start position:0% +there are groups sometimes our + + + align:start position:0% +there are groups sometimes our +instructors might actually check in with + + align:start position:0% +instructors might actually check in with + + + align:start position:0% +instructors might actually check in with +each group just you know hey what are + + align:start position:0% +each group just you know hey what are + + + align:start position:0% +each group just you know hey what are +you guys thinking about sometimes you + + align:start position:0% +you guys thinking about sometimes you + + + align:start position:0% +you guys thinking about sometimes you +just you know you're kind of lightly + + align:start position:0% +just you know you're kind of lightly + + + align:start position:0% +just you know you're kind of lightly +monitoring you're walking around you + + align:start position:0% +monitoring you're walking around you + + + align:start position:0% +monitoring you're walking around you +know um I know when I cover recitations + + align:start position:0% +know um I know when I cover recitations + + + align:start position:0% +know um I know when I cover recitations +sometimes I use + + align:start position:0% +sometimes I use + + + align:start position:0% +sometimes I use +it's time to prep for the thing that is + + align:start position:0% +it's time to prep for the thing that is + + + align:start position:0% +it's time to prep for the thing that is +coming next so if I need to draw + + align:start position:0% +coming next so if I need to draw + + + align:start position:0% +coming next so if I need to draw +something on the board that's gonna take + + align:start position:0% +something on the board that's gonna take + + + align:start position:0% +something on the board that's gonna take +a minute I'll put you on group so you + + align:start position:0% +a minute I'll put you on group so you + + + align:start position:0% +a minute I'll put you on group so you +can discuss while I draw that so you + + align:start position:0% +can discuss while I draw that so you + + + align:start position:0% +can discuss while I draw that so you +know it's this works really well as a + + align:start position:0% +know it's this works really well as a + + + align:start position:0% +know it's this works really well as a +technique to get students engaged in + + align:start position:0% +technique to get students engaged in + + + align:start position:0% +technique to get students engaged in +talking and honestly it's also nice from + + align:start position:0% +talking and honestly it's also nice from + + + align:start position:0% +talking and honestly it's also nice from +a classroom management perspective it + + align:start position:0% +a classroom management perspective it + + + align:start position:0% +a classroom management perspective it +breaks things up it gives you a little + + align:start position:0% +breaks things up it gives you a little + + + align:start position:0% +breaks things up it gives you a little +break from talking you can take a drink + + align:start position:0% +break from talking you can take a drink + + + align:start position:0% +break from talking you can take a drink +some water alright so then it's kind of + + align:start position:0% +some water alright so then it's kind of + + + align:start position:0% +some water alright so then it's kind of +our starting point this is one thing + + align:start position:0% +our starting point this is one thing + + + align:start position:0% +our starting point this is one thing +where I would say we do something like + + align:start position:0% +where I would say we do something like + + + align:start position:0% +where I would say we do something like +this in almost every single recitation + + align:start position:0% +this in almost every single recitation + + + align:start position:0% +this in almost every single recitation +every every Tuesday and Thursday the + + align:start position:0% +every every Tuesday and Thursday the + + + align:start position:0% +every every Tuesday and Thursday the +second one is one that I really like + + align:start position:0% +second one is one that I really like + + + align:start position:0% +second one is one that I really like +which is to have the students debate + + align:start position:0% +which is to have the students debate + + + align:start position:0% +which is to have the students debate +it's a little bit harder to work into a + + align:start position:0% +it's a little bit harder to work into a + + + align:start position:0% +it's a little bit harder to work into a +recitation right you need it you need a + + align:start position:0% +recitation right you need it you need a + + + align:start position:0% +recitation right you need it you need a +question that can be debated for us we + + align:start position:0% +question that can be debated for us we + + + align:start position:0% +question that can be debated for us we +have one recitation where the students + + align:start position:0% +have one recitation where the students + + + align:start position:0% +have one recitation where the students +read two short papers and the papers + + align:start position:0% +read two short papers and the papers + + + align:start position:0% +read two short papers and the papers +actually come to opposing conclusions + + align:start position:0% +actually come to opposing conclusions + + + align:start position:0% +actually come to opposing conclusions +and so it's an interesting lesson for + + align:start position:0% +and so it's an interesting lesson for + + + align:start position:0% +and so it's an interesting lesson for +them well how could this happen in + + align:start position:0% +them well how could this happen in + + + align:start position:0% +them well how could this happen in +science how could how could data say two + + align:start position:0% +science how could how could data say two + + + align:start position:0% +science how could how could data say two +different things it is mind blowing for + + align:start position:0% +different things it is mind blowing for + + + align:start position:0% +different things it is mind blowing for +them honestly it's it's it's pretty well + + align:start position:0% +them honestly it's it's it's pretty well + + + align:start position:0% +them honestly it's it's it's pretty well +and so you know we'll split them into + + align:start position:0% +and so you know we'll split them into + + + align:start position:0% +and so you know we'll split them into +two teams all right and we'll give them + + align:start position:0% +two teams all right and we'll give them + + + align:start position:0% +two teams all right and we'll give them +each a paper have them debate the + + align:start position:0% +each a paper have them debate the + + + align:start position:0% +each a paper have them debate the +students usually really like this they + + align:start position:0% +students usually really like this they + + + align:start position:0% +students usually really like this they +love to argue so they're very excited to + + align:start position:0% +love to argue so they're very excited to + + + align:start position:0% +love to argue so they're very excited to +do this it doesn't involve a bit more + + align:start position:0% +do this it doesn't involve a bit more + + + align:start position:0% +do this it doesn't involve a bit more +monitoring right you want to make sure + + align:start position:0% +monitoring right you want to make sure + + + align:start position:0% +monitoring right you want to make sure +that that one team or one person on one + + align:start position:0% +that that one team or one person on one + + + align:start position:0% +that that one team or one person on one +team doesn't dominate thinking that that + + align:start position:0% +team doesn't dominate thinking that that + + + align:start position:0% +team doesn't dominate thinking that that +will always have the team's you know + + align:start position:0% +will always have the team's you know + + + align:start position:0% +will always have the team's you know +converse beforehand like kind of get + + align:start position:0% +converse beforehand like kind of get + + + align:start position:0% +converse beforehand like kind of get +your argument together so you're ready + + align:start position:0% +your argument together so you're ready + + + align:start position:0% +your argument together so you're ready +to to prepare it for the class I + + align:start position:0% +to to prepare it for the class I + + + align:start position:0% +to to prepare it for the class I +personally think something like that + + align:start position:0% +personally think something like that + + + align:start position:0% +personally think something like that +could also work + + align:start position:0% +could also work + + + align:start position:0% +could also work +in small groups maybe you have groups of + + align:start position:0% +in small groups maybe you have groups of + + + align:start position:0% +in small groups maybe you have groups of +four teams of two debating um I will say + + align:start position:0% +four teams of two debating um I will say + + + align:start position:0% +four teams of two debating um I will say +you know when I've taught this + + align:start position:0% +you know when I've taught this + + + align:start position:0% +you know when I've taught this +recitation of these two papers there's + + align:start position:0% +recitation of these two papers there's + + + align:start position:0% +recitation of these two papers there's +like there's like a clear winner in my + + align:start position:0% +like there's like a clear winner in my + + + align:start position:0% +like there's like a clear winner in my +mind but the last time I taught this the + + align:start position:0% +mind but the last time I taught this the + + + align:start position:0% +mind but the last time I taught this the +opposing team made some very salient + + align:start position:0% +opposing team made some very salient + + + align:start position:0% +opposing team made some very salient +points like so they really they they + + align:start position:0% +points like so they really they they + + + align:start position:0% +points like so they really they they +really do well with this so this one is + + align:start position:0% +really do well with this so this one is + + + align:start position:0% +really do well with this so this one is +one that I think is really fun just not + + align:start position:0% +one that I think is really fun just not + + + align:start position:0% +one that I think is really fun just not +it a little bit more difficult to work + + align:start position:0% +it a little bit more difficult to work + + + align:start position:0% +it a little bit more difficult to work +in because of you know what it requires + + align:start position:0% +in because of you know what it requires + + + align:start position:0% +in because of you know what it requires +a third one something that we've + + align:start position:0% +a third one something that we've + + + align:start position:0% +a third one something that we've +actually started doing more of this year + + align:start position:0% +actually started doing more of this year + + + align:start position:0% +actually started doing more of this year +it's having them draw pictures so we'll + + align:start position:0% +it's having them draw pictures so we'll + + + align:start position:0% +it's having them draw pictures so we'll +ask them you know in groups to draw a + + align:start position:0% +ask them you know in groups to draw a + + + align:start position:0% +ask them you know in groups to draw a +picture + + align:start position:0% +picture + + + align:start position:0% +picture +the pictures on the board of whatever + + align:start position:0% +the pictures on the board of whatever + + + align:start position:0% +the pictures on the board of whatever +system we're talking about there may be + + align:start position:0% +system we're talking about there may be + + + align:start position:0% +system we're talking about there may be +some component of that system and what + + align:start position:0% +some component of that system and what + + + align:start position:0% +some component of that system and what +we end up with is a wide variety of + + align:start position:0% +we end up with is a wide variety of + + + align:start position:0% +we end up with is a wide variety of +drawings at varying levels of artistic + + align:start position:0% +drawings at varying levels of artistic + + + align:start position:0% +drawings at varying levels of artistic +skill and you know when we can come + + align:start position:0% +skill and you know when we can come + + + align:start position:0% +skill and you know when we can come +together and talk about what is each + + align:start position:0% +together and talk about what is each + + + align:start position:0% +together and talk about what is each +drawings showing what are the common + + align:start position:0% +drawings showing what are the common + + + align:start position:0% +drawings showing what are the common +things that we're seeing in all of these + + align:start position:0% +things that we're seeing in all of these + + + align:start position:0% +things that we're seeing in all of these +depictions what level of abstraction is + + align:start position:0% +depictions what level of abstraction is + + + align:start position:0% +depictions what level of abstraction is +each drawing capturing that's something + + align:start position:0% +each drawing capturing that's something + + + align:start position:0% +each drawing capturing that's something +that comes up a lot for us in oh three + + align:start position:0% +that comes up a lot for us in oh three + + + align:start position:0% +that comes up a lot for us in oh three +three I like this for a few reasons + + align:start position:0% +three I like this for a few reasons + + + align:start position:0% +three I like this for a few reasons +403 specifically part of our + + align:start position:0% +403 specifically part of our + + + align:start position:0% +403 specifically part of our +communication curriculum involves + + align:start position:0% +communication curriculum involves + + + align:start position:0% +communication curriculum involves +teaching the students how to design and + + align:start position:0% +teaching the students how to design and + + + align:start position:0% +teaching the students how to design and +draw figures so this you know for us + + align:start position:0% +draw figures so this you know for us + + + align:start position:0% +draw figures so this you know for us +this is just a great way for them to + + align:start position:0% +this is just a great way for them to + + + align:start position:0% +this is just a great way for them to +practice it also forces them to figure + + align:start position:0% +practice it also forces them to figure + + + align:start position:0% +practice it also forces them to figure +out exactly what the system is doing and + + align:start position:0% +out exactly what the system is doing and + + + align:start position:0% +out exactly what the system is doing and +so it can expose some areas where they + + align:start position:0% +so it can expose some areas where they + + + align:start position:0% +so it can expose some areas where they +might have missed something which always + + align:start position:0% +might have missed something which always + + + align:start position:0% +might have missed something which always +happens you know we expect them to read + + align:start position:0% +happens you know we expect them to read + + + align:start position:0% +happens you know we expect them to read +the papers before they come in they + + align:start position:0% +the papers before they come in they + + + align:start position:0% +the papers before they come in they +should be able to draw something it + + align:start position:0% +should be able to draw something it + + + align:start position:0% +should be able to draw something it +might not be perfect and that gives us a + + align:start position:0% +might not be perfect and that gives us a + + + align:start position:0% +might not be perfect and that gives us a +great a great space you know explore + + align:start position:0% +great a great space you know explore + + + align:start position:0% +great a great space you know explore +that like why was this confusing what is + + align:start position:0% +that like why was this confusing what is + + + align:start position:0% +that like why was this confusing what is +it about the paper that made this + + align:start position:0% +it about the paper that made this + + + align:start position:0% +it about the paper that made this +confusing um it's also just fun so the + + align:start position:0% +confusing um it's also just fun so the + + + align:start position:0% +confusing um it's also just fun so the +students get a kick out of it no the + + align:start position:0% +students get a kick out of it no the + + + align:start position:0% +students get a kick out of it no the +last activity that I want to talk about + + align:start position:0% +last activity that I want to talk about + + + align:start position:0% +last activity that I want to talk about +this is you know I'm gonna say that this + + align:start position:0% +this is you know I'm gonna say that this + + + align:start position:0% +this is you know I'm gonna say that this +is one of our more extreme activities we + + align:start position:0% +is one of our more extreme activities we + + + align:start position:0% +is one of our more extreme activities we +actually do it pretty frequently we will + + align:start position:0% +actually do it pretty frequently we will + + + align:start position:0% +actually do it pretty frequently we will +have students act things out also the + + align:start position:0% +have students act things out also the + + + align:start position:0% +have students act things out also the +hardest to make an icon for I just + + align:start position:0% +hardest to make an icon for I just + + + align:start position:0% +hardest to make an icon for I just +didn't know what to do they're um + + align:start position:0% +didn't know what to do they're um + + + align:start position:0% +didn't know what to do they're um +they're acting you can tell you know I + + align:start position:0% +they're acting you can tell you know I + + + align:start position:0% +they're acting you can tell you know I +tell people about this for a lot a lot + + align:start position:0% +tell people about this for a lot a lot + + + align:start position:0% +tell people about this for a lot a lot +and then whenever I say it I go we act + + align:start position:0% +and then whenever I say it I go we act + + + align:start position:0% +and then whenever I say it I go we act +things out know through all the time + + align:start position:0% +things out know through all the time + + + align:start position:0% +things out know through all the time +they are for sure intrigued they are not + + align:start position:0% +they are for sure intrigued they are not + + + align:start position:0% +they are for sure intrigued they are not +sure exactly what that would entail so I + + align:start position:0% +sure exactly what that would entail so I + + + align:start position:0% +sure exactly what that would entail so I +was going to have you all do this + + align:start position:0% +was going to have you all do this + + + align:start position:0% +was going to have you all do this +activity but I we're half gonna do this + + align:start position:0% +activity but I we're half gonna do this + + + align:start position:0% +activity but I we're half gonna do this +activity so I kind of want to go through + + align:start position:0% +activity so I kind of want to go through + + + align:start position:0% +activity so I kind of want to go through +one of our examples actually in detail + + align:start position:0% +one of our examples actually in detail + + + align:start position:0% +one of our examples actually in detail +where we have them act out a system + + align:start position:0% +where we have them act out a system + + + align:start position:0% +where we have them act out a system +called Map Reduce + + align:start position:0% +called Map Reduce + + + align:start position:0% +called Map Reduce +but for this to make any sense you need + + align:start position:0% +but for this to make any sense you need + + + align:start position:0% +but for this to make any sense you need +to understand a little bit about what + + align:start position:0% +to understand a little bit about what + + + align:start position:0% +to understand a little bit about what +Map Reduce does so you're going to + + align:start position:0% +Map Reduce does so you're going to + + + align:start position:0% +Map Reduce does so you're going to +become I don't want to say Map Reduce + + align:start position:0% +become I don't want to say Map Reduce + + + align:start position:0% +become I don't want to say Map Reduce +experts Map Reduce novices for the next + + align:start position:0% +experts Map Reduce novices for the next + + + align:start position:0% +experts Map Reduce novices for the next +five minutes all right so brief aside of + + align:start position:0% +five minutes all right so brief aside of + + + align:start position:0% +five minutes all right so brief aside of +technical material mapreduces this + + align:start position:0% +technical material mapreduces this + + + align:start position:0% +technical material mapreduces this +system for + + align:start position:0% +system for + + + align:start position:0% +system for +forming parallel computation and so + + align:start position:0% +forming parallel computation and so + + + align:start position:0% +forming parallel computation and so +here's the canonical example we have a + + align:start position:0% +here's the canonical example we have a + + + align:start position:0% +here's the canonical example we have a +large piece of text all right + + align:start position:0% +large piece of text all right + + + align:start position:0% +large piece of text all right +the Library of Congress has a lot of + + align:start position:0% +the Library of Congress has a lot of + + + align:start position:0% +the Library of Congress has a lot of +books in it these books were gonna + + align:start position:0% +books in it these books were gonna + + + align:start position:0% +books in it these books were gonna +digitize this and so the data from these + + align:start position:0% +digitize this and so the data from these + + + align:start position:0% +digitize this and so the data from these +books is spread out on all different + + align:start position:0% +books is spread out on all different + + + align:start position:0% +books is spread out on all different +machines alright so we have a lot of + + align:start position:0% +machines alright so we have a lot of + + + align:start position:0% +machines alright so we have a lot of +computers let's say let's you all can be + + align:start position:0% +computers let's say let's you all can be + + + align:start position:0% +computers let's say let's you all can be +computers so each one of you has a book + + align:start position:0% +computers so each one of you has a book + + + align:start position:0% +computers so each one of you has a book +from the library of congress and here is + + align:start position:0% +from the library of congress and here is + + + align:start position:0% +from the library of congress and here is +the problem that we want to solve the + + align:start position:0% +the problem that we want to solve the + + + align:start position:0% +the problem that we want to solve the +canonical MapReduce problem we want to + + align:start position:0% +canonical MapReduce problem we want to + + + align:start position:0% +canonical MapReduce problem we want to +count the number of occurrences of each + + align:start position:0% +count the number of occurrences of each + + + align:start position:0% +count the number of occurrences of each +word in this entire corpus so I want to + + align:start position:0% +word in this entire corpus so I want to + + + align:start position:0% +word in this entire corpus so I want to +know how many times does the word apple + + align:start position:0% +know how many times does the word apple + + + align:start position:0% +know how many times does the word apple +appear how many times does the word ball + + align:start position:0% +appear how many times does the word ball + + + align:start position:0% +appear how many times does the word ball +up here how many times is the word the + + align:start position:0% +up here how many times is the word the + + + align:start position:0% +up here how many times is the word the +up here okay + + align:start position:0% +up here okay + + + align:start position:0% +up here okay +it's the canonical problem I you all + + align:start position:0% +it's the canonical problem I you all + + + align:start position:0% +it's the canonical problem I you all +don't look like you actually want to + + align:start position:0% +don't look like you actually want to + + + align:start position:0% +don't look like you actually want to +know that you do you want to know how + + align:start position:0% +know that you do you want to know how + + + align:start position:0% +know that you do you want to know how +many times the word Apple occurs in the + + align:start position:0% +many times the word Apple occurs in the + + + align:start position:0% +many times the word Apple occurs in the +Library of Congress so you can imagine + + align:start position:0% +Library of Congress so you can imagine + + + align:start position:0% +Library of Congress so you can imagine +I'm doing that with one computer where + + align:start position:0% +I'm doing that with one computer where + + + align:start position:0% +I'm doing that with one computer where +that computer just reads reads every + + align:start position:0% +that computer just reads reads every + + + align:start position:0% +that computer just reads reads every +book in sequence and keeps track of + + align:start position:0% +book in sequence and keeps track of + + + align:start position:0% +book in sequence and keeps track of +these counts and that would be very slow + + align:start position:0% +these counts and that would be very slow + + + align:start position:0% +these counts and that would be very slow +so instead what we can do is we can have + + align:start position:0% +so instead what we can do is we can have + + + align:start position:0% +so instead what we can do is we can have +multiple computers participate right you + + align:start position:0% +multiple computers participate right you + + + align:start position:0% +multiple computers participate right you +all have a portion of the Library of + + align:start position:0% +all have a portion of the Library of + + + align:start position:0% +all have a portion of the Library of +Congress you all can read your data you + + align:start position:0% +Congress you all can read your data you + + + align:start position:0% +Congress you all can read your data you +can make accounts for your pieces of + + align:start position:0% +can make accounts for your pieces of + + + align:start position:0% +can make accounts for your pieces of +data right this is the map phase and + + align:start position:0% +data right this is the map phase and + + + align:start position:0% +data right this is the map phase and +then we would need some way to kind of + + align:start position:0% +then we would need some way to kind of + + + align:start position:0% +then we would need some way to kind of +combine those results right so if deepa + + align:start position:0% +combine those results right so if deepa + + + align:start position:0% +combine those results right so if deepa +finds that the word Apple occurred five + + align:start position:0% +finds that the word Apple occurred five + + + align:start position:0% +finds that the word Apple occurred five +times in her text if Jesse found that it + + align:start position:0% +times in her text if Jesse found that it + + + align:start position:0% +times in her text if Jesse found that it +occurred six times + + align:start position:0% +occurred six times + + + align:start position:0% +occurred six times +I need something to add those up right + + align:start position:0% +I need something to add those up right + + + align:start position:0% +I need something to add those up right +that would be the reduce face so part of + + align:start position:0% +that would be the reduce face so part of + + + align:start position:0% +that would be the reduce face so part of +the inside of this system is that there + + align:start position:0% +the inside of this system is that there + + + align:start position:0% +the inside of this system is that there +are a lot of common problems in computer + + align:start position:0% +are a lot of common problems in computer + + + align:start position:0% +are a lot of common problems in computer +science that can be described this way + + align:start position:0% +science that can be described this way + + + align:start position:0% +science that can be described this way +this is a system that came from Google + + align:start position:0% +this is a system that came from Google + + + align:start position:0% +this is a system that came from Google +so Google is doing this on your data all + + align:start position:0% +so Google is doing this on your data all + + + align:start position:0% +so Google is doing this on your data all +the time there are mapping and reducing + + align:start position:0% +the time there are mapping and reducing + + + align:start position:0% +the time there are mapping and reducing +everything about you so let's see how + + align:start position:0% +everything about you so let's see how + + + align:start position:0% +everything about you so let's see how +that would actually work how the system + + align:start position:0% +that would actually work how the system + + + align:start position:0% +that would actually work how the system +would work all right + + align:start position:0% +would work all right + + + align:start position:0% +would work all right +Jesse come play your role in this thing + + align:start position:0% +Jesse come play your role in this thing + + + align:start position:0% +Jesse come play your role in this thing +you do have to wear the hat it's active + + align:start position:0% +you do have to wear the hat it's active + + + align:start position:0% +you do have to wear the hat it's active +learning I've got a right master on it + + align:start position:0% + + + + align:start position:0% + +I think a lot of things in life should + + align:start position:0% +I think a lot of things in life should + + + align:start position:0% +I think a lot of things in life should +be more fun so there's really no reason + + align:start position:0% +be more fun so there's really no reason + + + align:start position:0% +be more fun so there's really no reason +for Jesse to wear this hat but like + + align:start position:0% +for Jesse to wear this hat but like + + + align:start position:0% +for Jesse to wear this hat but like +there's also not a reason for her not to + + align:start position:0% +there's also not a reason for her not to + + + align:start position:0% +there's also not a reason for her not to +wear this hat so yeah well you can tilt + + align:start position:0% +wear this hat so yeah well you can tilt + + + align:start position:0% +wear this hat so yeah well you can tilt +up the Hat back a little bit maybe + + align:start position:0% +up the Hat back a little bit maybe + + + align:start position:0% +up the Hat back a little bit maybe +so I'm Map Reduce there is a one machine + + align:start position:0% +so I'm Map Reduce there is a one machine + + + align:start position:0% +so I'm Map Reduce there is a one machine +that acts as the coordination for this + + align:start position:0% +that acts as the coordination for this + + + align:start position:0% +that acts as the coordination for this +the master machine as Jesse is so so + + align:start position:0% +the master machine as Jesse is so so + + + align:start position:0% +the master machine as Jesse is so so +doing such a great job acting for us and + + align:start position:0% +doing such a great job acting for us and + + + align:start position:0% +doing such a great job acting for us and +so what the Masters job would be and you + + align:start position:0% +so what the Masters job would be and you + + + align:start position:0% +so what the Masters job would be and you +don't have you're just we just want to + + align:start position:0% +don't have you're just we just want to + + + align:start position:0% +don't have you're just we just want to +visualize you don't hey you're just a + + align:start position:0% +visualize you don't hey you're just a + + + align:start position:0% +visualize you don't hey you're just a +prop + + align:start position:0% +prop + + + align:start position:0% +prop +yes um so it would start by assigning + + align:start position:0% +yes um so it would start by assigning + + + align:start position:0% +yes um so it would start by assigning +jobs to workers no you all I didn't make + + align:start position:0% +jobs to workers no you all I didn't make + + + align:start position:0% +jobs to workers no you all I didn't make +hats for all of you there wasn't - I + + align:start position:0% +hats for all of you there wasn't - I + + + align:start position:0% +hats for all of you there wasn't - I +know very sorry but you're all workers + + align:start position:0% +know very sorry but you're all workers + + + align:start position:0% +know very sorry but you're all workers +only the master gets a hat all right so + + align:start position:0% +only the master gets a hat all right so + + + align:start position:0% +only the master gets a hat all right so +you are all workers so they're one of + + align:start position:0% +you are all workers so they're one of + + + align:start position:0% +you are all workers so they're one of +the first things just master Jesse would + + align:start position:0% +the first things just master Jesse would + + + align:start position:0% +the first things just master Jesse would +do would be to assign map jobs to + + align:start position:0% +do would be to assign map jobs to + + + align:start position:0% +do would be to assign map jobs to +workers right and she would tell you + + align:start position:0% +workers right and she would tell you + + + align:start position:0% +workers right and she would tell you +things like exactly what data to operate + + align:start position:0% +things like exactly what data to operate + + + align:start position:0% +things like exactly what data to operate +on so you know imagine a scenario where + + align:start position:0% +on so you know imagine a scenario where + + + align:start position:0% +on so you know imagine a scenario where +you a worker machine worker machine has + + align:start position:0% +you a worker machine worker machine has + + + align:start position:0% +you a worker machine worker machine has +data from a ton of different corpuses on + + align:start position:0% +data from a ton of different corpuses on + + + align:start position:0% +data from a ton of different corpuses on +it so does he actually has to say okay + + align:start position:0% +it so does he actually has to say okay + + + align:start position:0% +it so does he actually has to say okay +worry about the Library of Congress part + + align:start position:0% +worry about the Library of Congress part + + + align:start position:0% +worry about the Library of Congress part +of your data and you would begin + + align:start position:0% +of your data and you would begin + + + align:start position:0% +of your data and you would begin +operating on that you'd count you count + + align:start position:0% +operating on that you'd count you count + + + align:start position:0% +operating on that you'd count you count +your words and you'd write out some + + align:start position:0% +your words and you'd write out some + + + align:start position:0% +your words and you'd write out some +results to your disk that you also have + + align:start position:0% +results to your disk that you also have + + + align:start position:0% +results to your disk that you also have +as a machine in this and then when you + + align:start position:0% +as a machine in this and then when you + + + align:start position:0% +as a machine in this and then when you +were done you would report back to Jesse + + align:start position:0% +were done you would report back to Jesse + + + align:start position:0% +were done you would report back to Jesse +and you would you know you'd tell her + + align:start position:0% +and you would you know you'd tell her + + + align:start position:0% +and you would you know you'd tell her +some various meta information kind of + + align:start position:0% +some various meta information kind of + + + align:start position:0% +some various meta information kind of +like oh these are the words that I found + + align:start position:0% +like oh these are the words that I found + + + align:start position:0% +like oh these are the words that I found +you don't have to Center all of your + + align:start position:0% +you don't have to Center all of your + + + align:start position:0% +you don't have to Center all of your +results because Webber if Congress is + + align:start position:0% +results because Webber if Congress is + + + align:start position:0% +results because Webber if Congress is +big you have a lot of data but you might + + align:start position:0% +big you have a lot of data but you might + + + align:start position:0% +big you have a lot of data but you might +tell Jesse hey I found Apple say no once + + align:start position:0% +tell Jesse hey I found Apple say no once + + + align:start position:0% +tell Jesse hey I found Apple say no once +all of you are finished doing your map + + align:start position:0% +all of you are finished doing your map + + + align:start position:0% +all of you are finished doing your map +jobs jesse has all of this kind of meta + + align:start position:0% +jobs jesse has all of this kind of meta + + + align:start position:0% +jobs jesse has all of this kind of meta +information so you can start assigning + + align:start position:0% +information so you can start assigning + + + align:start position:0% +information so you can start assigning +the reduced jobs and the reduced jobs + + align:start position:0% +the reduced jobs and the reduced jobs + + + align:start position:0% +the reduced jobs and the reduced jobs +are a little bit different so deepa if + + align:start position:0% +are a little bit different so deepa if + + + align:start position:0% +are a little bit different so deepa if +it was your job to reduce say the word + + align:start position:0% +it was your job to reduce say the word + + + align:start position:0% +it was your job to reduce say the word +apple you need to know a couple things + + align:start position:0% +apple you need to know a couple things + + + align:start position:0% +apple you need to know a couple things +you need to know well which one of these + + align:start position:0% +you need to know well which one of these + + + align:start position:0% +you need to know well which one of these +machines actually found the word apple + + align:start position:0% +machines actually found the word apple + + + align:start position:0% +machines actually found the word apple +right it's it's not necessarily going to + + align:start position:0% +right it's it's not necessarily going to + + + align:start position:0% +right it's it's not necessarily going to +be in every piece of data and Jesse + + align:start position:0% +be in every piece of data and Jesse + + + align:start position:0% +be in every piece of data and Jesse +would be able to tell you that she + + align:start position:0% +would be able to tell you that she + + + align:start position:0% +would be able to tell you that she +basically say hey deepa contact these + + align:start position:0% +basically say hey deepa contact these + + + align:start position:0% +basically say hey deepa contact these +workers they have the data you need you + + align:start position:0% +workers they have the data you need you + + + align:start position:0% +workers they have the data you need you +can you know add them together in this + + align:start position:0% +can you know add them together in this + + + align:start position:0% +can you know add them together in this +example reduce functions can be + + align:start position:0% +example reduce functions can be + + + align:start position:0% +example reduce functions can be +more complex than this I thought let's + + align:start position:0% +more complex than this I thought let's + + + align:start position:0% +more complex than this I thought let's +start slow all right and so the reduced + + align:start position:0% +start slow all right and so the reduced + + + align:start position:0% +start slow all right and so the reduced +workers would go you'd reduce you'd + + align:start position:0% +workers would go you'd reduce you'd + + + align:start position:0% +workers would go you'd reduce you'd +report results back to Jessie and then + + align:start position:0% +report results back to Jessie and then + + + align:start position:0% +report results back to Jessie and then +we'd have our fool counts + + align:start position:0% +we'd have our fool counts + + + align:start position:0% +we'd have our fool counts +I'm trying to decide how long I want you + + align:start position:0% +I'm trying to decide how long I want you + + + align:start position:0% +I'm trying to decide how long I want you +to stand here and like the answer is for + + align:start position:0% +to stand here and like the answer is for + + + align:start position:0% +to stand here and like the answer is for +the rest of the talk but we're almost + + align:start position:0% +the rest of the talk but we're almost + + + align:start position:0% +the rest of the talk but we're almost +you can almost have done all right so + + align:start position:0% +you can almost have done all right so + + + align:start position:0% +you can almost have done all right so +this is the basic idea I thought that + + align:start position:0% +this is the basic idea I thought that + + + align:start position:0% +this is the basic idea I thought that +would be a lot + + align:start position:0% +would be a lot + + + align:start position:0% +would be a lot +I didn't prep you for that you know + + align:start position:0% +I didn't prep you for that you know + + + align:start position:0% +I didn't prep you for that you know +don't go yet though so this is the basic + + align:start position:0% +don't go yet though so this is the basic + + + align:start position:0% +don't go yet though so this is the basic +idea of MapReduce this is the type of + + align:start position:0% +idea of MapReduce this is the type of + + + align:start position:0% +idea of MapReduce this is the type of +thing we'd actually expect the students + + align:start position:0% +thing we'd actually expect the students + + + align:start position:0% +thing we'd actually expect the students +to know coming in they've read the paper + + align:start position:0% +to know coming in they've read the paper + + + align:start position:0% +to know coming in they've read the paper +they should understand this sort of + + align:start position:0% +they should understand this sort of + + + align:start position:0% +they should understand this sort of +level of coordination but there are a + + align:start position:0% +level of coordination but there are a + + + align:start position:0% +level of coordination but there are a +lot of details that we left out for + + align:start position:0% +lot of details that we left out for + + + align:start position:0% +lot of details that we left out for +instance I didn't ask you all well hey + + align:start position:0% +instance I didn't ask you all well hey + + + align:start position:0% +instance I didn't ask you all well hey +what happens if a machine fails worker + + align:start position:0% +what happens if a machine fails worker + + + align:start position:0% +what happens if a machine fails worker +deep out crashes what did we do yeah all + + align:start position:0% +deep out crashes what did we do yeah all + + + align:start position:0% +deep out crashes what did we do yeah all +the time yeah you know is the data that + + align:start position:0% +the time yeah you know is the data that + + + align:start position:0% +the time yeah you know is the data that +she was storing is it anywhere else in + + align:start position:0% +she was storing is it anywhere else in + + + align:start position:0% +she was storing is it anywhere else in +the system how do we know what if she + + align:start position:0% +the system how do we know what if she + + + align:start position:0% +the system how do we know what if she +kind of had half have finished the job + + align:start position:0% +kind of had half have finished the job + + + align:start position:0% +kind of had half have finished the job +right what do we do or even you know + + align:start position:0% +right what do we do or even you know + + + align:start position:0% +right what do we do or even you know +what if there was no crash but like + + align:start position:0% +what if there was no crash but like + + + align:start position:0% +what if there was no crash but like +let's say that worker Janet is just + + align:start position:0% +let's say that worker Janet is just + + + align:start position:0% +let's say that worker Janet is just +running really slow like she's going + + align:start position:0% +running really slow like she's going + + + align:start position:0% +running really slow like she's going +she's she's working hard but it's ever + + align:start position:0% +she's she's working hard but it's ever + + + align:start position:0% +she's she's working hard but it's ever +like everyone else is finished and we + + align:start position:0% +like everyone else is finished and we + + + align:start position:0% +like everyone else is finished and we +were just waiting on Jim all right and + + align:start position:0% +were just waiting on Jim all right and + + + align:start position:0% +were just waiting on Jim all right and +these are those types of things those + + align:start position:0% +these are those types of things those + + + align:start position:0% +these are those types of things those +are the interesting things about + + align:start position:0% +are the interesting things about + + + align:start position:0% +are the interesting things about +MapReduce that's the point where there + + align:start position:0% +MapReduce that's the point where there + + + align:start position:0% +MapReduce that's the point where there +are trade-offs for the students to think + + align:start position:0% +are trade-offs for the students to think + + + align:start position:0% +are trade-offs for the students to think +about so it's not just important to + + align:start position:0% +about so it's not just important to + + + align:start position:0% +about so it's not just important to +think about oh gosh what does happen if + + align:start position:0% +think about oh gosh what does happen if + + + align:start position:0% +think about oh gosh what does happen if +a machine crashes or is slow but why + + align:start position:0% +a machine crashes or is slow but why + + + align:start position:0% +a machine crashes or is slow but why +does it happen that way so to do this we + + align:start position:0% +does it happen that way so to do this we + + + align:start position:0% +does it happen that way so to do this we +actually have them act out this system + + align:start position:0% +actually have them act out this system + + + align:start position:0% +actually have them act out this system +and from the way that I've described it + + align:start position:0% +and from the way that I've described it + + + align:start position:0% +and from the way that I've described it +here you might think well I have one + + align:start position:0% +here you might think well I have one + + + align:start position:0% +here you might think well I have one +soon and be the master and everybody + + align:start position:0% +soon and be the master and everybody + + + align:start position:0% +soon and be the master and everybody +else is a worker right that's kind of + + align:start position:0% +else is a worker right that's kind of + + + align:start position:0% +else is a worker right that's kind of +what I was setting you all up for this + + align:start position:0% +what I was setting you all up for this + + + align:start position:0% +what I was setting you all up for this +is not actually how we do it normally + + align:start position:0% +is not actually how we do it normally + + + align:start position:0% +is not actually how we do it normally +well for when it doesn't work with the + + align:start position:0% +well for when it doesn't work with the + + + align:start position:0% +well for when it doesn't work with the +size of our recitations even here this + + align:start position:0% +size of our recitations even here this + + + align:start position:0% +size of our recitations even here this +is a lot of workers for one student to + + align:start position:0% +is a lot of workers for one student to + + + align:start position:0% +is a lot of workers for one student to +be in charge of and also you know if + + align:start position:0% +be in charge of and also you know if + + + align:start position:0% +be in charge of and also you know if +Jesse was maybe more of a shy student + + align:start position:0% +Jesse was maybe more of a shy student + + + align:start position:0% +Jesse was maybe more of a shy student +she's like this is the worst day of my + + align:start position:0% +she's like this is the worst day of my + + + align:start position:0% +she's like this is the worst day of my +entire life + + align:start position:0% +entire life + + + align:start position:0% +entire life +Katrina has been here a hat and I have + + align:start position:0% +Katrina has been here a hat and I have + + + align:start position:0% +Katrina has been here a hat and I have +to say I am in charge of everything it's + + align:start position:0% +to say I am in charge of everything it's + + + align:start position:0% +to say I am in charge of everything it's +not good it's not good so in practice + + align:start position:0% +not good it's not good so in practice + + + align:start position:0% +not good it's not good so in practice +here's how we do this activity + + align:start position:0% +here's how we do this activity + + + align:start position:0% +here's how we do this activity +you can sit down if you want you don't + + align:start position:0% +you can sit down if you want you don't + + + align:start position:0% +you can sit down if you want you don't +have to be here anymore should I keep I + + align:start position:0% +have to be here anymore should I keep I + + + align:start position:0% +have to be here anymore should I keep I +think definitely yes I think absolutely + + align:start position:0% +think definitely yes I think absolutely + + + align:start position:0% +think definitely yes I think absolutely +um so we do start by assigning students + + align:start position:0% +um so we do start by assigning students + + + align:start position:0% +um so we do start by assigning students +roles but we will usually have them in + + align:start position:0% +roles but we will usually have them in + + + align:start position:0% +roles but we will usually have them in +teams so there will be a master team + + align:start position:0% +teams so there will be a master team + + + align:start position:0% +teams so there will be a master team +each worker will be a team of maybe two + + align:start position:0% +each worker will be a team of maybe two + + + align:start position:0% +each worker will be a team of maybe two +or three students this is good for a lot + + align:start position:0% +or three students this is good for a lot + + + align:start position:0% +or three students this is good for a lot +of reasons um again for the reason of + + align:start position:0% +of reasons um again for the reason of + + + align:start position:0% +of reasons um again for the reason of +kind of getting the Shire students to be + + align:start position:0% +kind of getting the Shire students to be + + + align:start position:0% +kind of getting the Shire students to be +a little bit more comfortable + + align:start position:0% +a little bit more comfortable + + + align:start position:0% +a little bit more comfortable +all right no one student is in charge of + + align:start position:0% +all right no one student is in charge of + + + align:start position:0% +all right no one student is in charge of +something from a logistical standpoint + + align:start position:0% +something from a logistical standpoint + + + align:start position:0% +something from a logistical standpoint +again I glazed over many a detail in Map + + align:start position:0% +again I glazed over many a detail in Map + + + align:start position:0% +again I glazed over many a detail in Map +Reduce but you can imagine that the + + align:start position:0% +Reduce but you can imagine that the + + + align:start position:0% +Reduce but you can imagine that the +master has a lot to do a lot to keep + + align:start position:0% +master has a lot to do a lot to keep + + + align:start position:0% +master has a lot to do a lot to keep +track of and so we will often you know + + align:start position:0% +track of and so we will often you know + + + align:start position:0% +track of and so we will often you know +we'll have our master team and we'll + + align:start position:0% +we'll have our master team and we'll + + + align:start position:0% +we'll have our master team and we'll +actually give each student in that team + + align:start position:0% +actually give each student in that team + + + align:start position:0% +actually give each student in that team +a task so one might run the clock + + align:start position:0% +a task so one might run the clock + + + align:start position:0% +a task so one might run the clock +all right timing in this system is + + align:start position:0% +all right timing in this system is + + + align:start position:0% +all right timing in this system is +important we'll see an example of that + + align:start position:0% +important we'll see an example of that + + + align:start position:0% +important we'll see an example of that +in a second + + align:start position:0% +in a second + + + align:start position:0% +in a second +one keeps track of what mapped tasks to + + align:start position:0% +one keeps track of what mapped tasks to + + + align:start position:0% +one keeps track of what mapped tasks to +complete one assigns the tasks things + + align:start position:0% +complete one assigns the tasks things + + + align:start position:0% +complete one assigns the tasks things +like that we have found we've actually + + align:start position:0% +like that we have found we've actually + + + align:start position:0% +like that we have found we've actually +done this activity a number of times it + + align:start position:0% +done this activity a number of times it + + + align:start position:0% +done this activity a number of times it +gets better every time one of the things + + align:start position:0% +gets better every time one of the things + + + align:start position:0% +gets better every time one of the things +we learned the most quickly is that the + + align:start position:0% +we learned the most quickly is that the + + + align:start position:0% +we learned the most quickly is that the +master we had to give the students who + + align:start position:0% +master we had to give the students who + + + align:start position:0% +master we had to give the students who +were doing the master extremely detailed + + align:start position:0% +were doing the master extremely detailed + + + align:start position:0% +were doing the master extremely detailed +instructions if we just said do the + + align:start position:0% +instructions if we just said do the + + + align:start position:0% +instructions if we just said do the +Masters job they were not ready for that + + align:start position:0% +Masters job they were not ready for that + + + align:start position:0% +Masters job they were not ready for that +in some sections in fact some of my + + align:start position:0% +in some sections in fact some of my + + + align:start position:0% +in some sections in fact some of my +instructors prefer to do this where the + + align:start position:0% +instructors prefer to do this where the + + + align:start position:0% +instructors prefer to do this where the +instructor just is the master and so + + align:start position:0% +instructor just is the master and so + + + align:start position:0% +instructor just is the master and so +they can be kind of in charge of + + align:start position:0% +they can be kind of in charge of + + + align:start position:0% +they can be kind of in charge of +coordination workers in this example get + + align:start position:0% +coordination workers in this example get + + + align:start position:0% +coordination workers in this example get +a little bit of an easier job again + + align:start position:0% +a little bit of an easier job again + + + align:start position:0% +a little bit of an easier job again +we're putting them in teams of two two + + align:start position:0% +we're putting them in teams of two two + + + align:start position:0% +we're putting them in teams of two two +three sometimes you know we might give + + align:start position:0% +three sometimes you know we might give + + + align:start position:0% +three sometimes you know we might give +them a sheet with words on it and + + align:start position:0% +them a sheet with words on it and + + + align:start position:0% +them a sheet with words on it and +actually ask them to count the words + + align:start position:0% +actually ask them to count the words + + + align:start position:0% +actually ask them to count the words +sometimes we'll give them a sheet that + + align:start position:0% +sometimes we'll give them a sheet that + + + align:start position:0% +sometimes we'll give them a sheet that +kind of just says here's the words in + + align:start position:0% +kind of just says here's the words in + + + align:start position:0% +kind of just says here's the words in +your data and here are the counts that + + align:start position:0% +your data and here are the counts that + + + align:start position:0% +your data and here are the counts that +might seem like oh gosh what's the point + + align:start position:0% +might seem like oh gosh what's the point + + + align:start position:0% +might seem like oh gosh what's the point +they're not actually doing the worker + + align:start position:0% +they're not actually doing the worker + + + align:start position:0% +they're not actually doing the worker +job counting the words in the text is + + align:start position:0% +job counting the words in the text is + + + align:start position:0% +job counting the words in the text is +not the interesting part of this system + + align:start position:0% +not the interesting part of this system + + + align:start position:0% +not the interesting part of this system +so sometimes we'll just skip that it + + align:start position:0% +so sometimes we'll just skip that it + + + align:start position:0% +so sometimes we'll just skip that it +also again lets us do some very precise + + align:start position:0% +also again lets us do some very precise + + + align:start position:0% +also again lets us do some very precise +things with timing so once these roles + + align:start position:0% +things with timing so once these roles + + + align:start position:0% +things with timing so once these roles +are assigned we're gonna run the + + align:start position:0% +are assigned we're gonna run the + + + align:start position:0% +are assigned we're gonna run the +protocol all right so the person keeping + + align:start position:0% +protocol all right so the person keeping + + + align:start position:0% +protocol all right so the person keeping +track of the master clock will advance + + align:start position:0% +track of the master clock will advance + + + align:start position:0% +track of the master clock will advance +it you know one click two clicks etc + + align:start position:0% +it you know one click two clicks etc + + + align:start position:0% +it you know one click two clicks etc +various math jobs + + align:start position:0% +various math jobs + + + align:start position:0% +various math jobs +we'll complete most of the time when we + + align:start position:0% +we'll complete most of the time when we + + + align:start position:0% +we'll complete most of the time when we +give them a paper that says you know + + align:start position:0% +give them a paper that says you know + + + align:start position:0% +give them a paper that says you know +here's your words and your counts will + + align:start position:0% +here's your words and your counts will + + + align:start position:0% +here's your words and your counts will +also say hey it takes you know three + + align:start position:0% +also say hey it takes you know three + + + align:start position:0% +also say hey it takes you know three +clock cycles for you to complete and so + + align:start position:0% +clock cycles for you to complete and so + + + align:start position:0% +clock cycles for you to complete and so +once it's the clock has ticked three + + align:start position:0% +once it's the clock has ticked three + + + align:start position:0% +once it's the clock has ticked three +times they'll report back to the master + + align:start position:0% +times they'll report back to the master + + + align:start position:0% +times they'll report back to the master +team because of how we set up those map + + align:start position:0% +team because of how we set up those map + + + align:start position:0% +team because of how we set up those map +tasks some of them will also fail some + + align:start position:0% +tasks some of them will also fail some + + + align:start position:0% +tasks some of them will also fail some +of them will have papers that say I it's + + align:start position:0% +of them will have papers that say I it's + + + align:start position:0% +of them will have papers that say I it's +I failed after quick two and they have + + align:start position:0% +I failed after quick two and they have + + + align:start position:0% +I failed after quick two and they have +to kind of announce it to the class + + align:start position:0% +to kind of announce it to the class + + + align:start position:0% +to kind of announce it to the class +I'm in that point you know we pause what + + align:start position:0% +I'm in that point you know we pause what + + + align:start position:0% +I'm in that point you know we pause what +happens right what happens when a + + align:start position:0% +happens right what happens when a + + + align:start position:0% +happens right what happens when a +machine fails what does not produce do + + align:start position:0% +machine fails what does not produce do + + + align:start position:0% +machine fails what does not produce do +why does it do that spoilers for you all + + align:start position:0% +why does it do that spoilers for you all + + + align:start position:0% +why does it do that spoilers for you all +in MapReduce the master will reassign + + align:start position:0% +in MapReduce the master will reassign + + + align:start position:0% +in MapReduce the master will reassign +that task to somewhere else and I'm part + + align:start position:0% +that task to somewhere else and I'm part + + + align:start position:0% +that task to somewhere else and I'm part +of that challenge is making sure that + + align:start position:0% +of that challenge is making sure that + + + align:start position:0% +of that challenge is making sure that +the new worker has access to the data + + align:start position:0% +the new worker has access to the data + + + align:start position:0% +the new worker has access to the data +that was on the crashed machine + + align:start position:0% +that was on the crashed machine + + + align:start position:0% +that was on the crashed machine +MapReduce replicates data so we talk + + align:start position:0% +MapReduce replicates data so we talk + + + align:start position:0% +MapReduce replicates data so we talk +about how that happens you know the + + align:start position:0% +about how that happens you know the + + + align:start position:0% +about how that happens you know the +protocol continues the students will + + align:start position:0% +protocol continues the students will + + + align:start position:0% +protocol continues the students will +find that you know one map task it + + align:start position:0% +find that you know one map task it + + + align:start position:0% +find that you know one map task it +hasn't crashed but it's taking a very + + align:start position:0% +hasn't crashed but it's taking a very + + + align:start position:0% +hasn't crashed but it's taking a very +long time and that's another good point + + align:start position:0% +long time and that's another good point + + + align:start position:0% +long time and that's another good point +for discussion all right what does + + align:start position:0% +for discussion all right what does + + + align:start position:0% +for discussion all right what does +MapReduce do does it just wait in + + align:start position:0% +MapReduce do does it just wait in + + + align:start position:0% +MapReduce do does it just wait in +practice it restarts the task and + + align:start position:0% +practice it restarts the task and + + + align:start position:0% +practice it restarts the task and +another machine and then so then oh + + align:start position:0% +another machine and then so then oh + + + align:start position:0% +another machine and then so then oh +there's a question these these two + + align:start position:0% +there's a question these these two + + + align:start position:0% +there's a question these these two +machines are running the same thing huh + + align:start position:0% +machines are running the same thing huh + + + align:start position:0% +machines are running the same thing huh +what do we do who do we listen to how do + + align:start position:0% +what do we do who do we listen to how do + + + align:start position:0% +what do we do who do we listen to how do +we get the data and this is why the + + align:start position:0% +we get the data and this is why the + + + align:start position:0% +we get the data and this is why the +timing of that activity is so important + + align:start position:0% +timing of that activity is so important + + + align:start position:0% +timing of that activity is so important +because a lot of the discussion points + + align:start position:0% +because a lot of the discussion points + + + align:start position:0% +because a lot of the discussion points +about MapReduce come from what we do + + align:start position:0% +about MapReduce come from what we do + + + align:start position:0% +about MapReduce come from what we do +when things are slow or when things fail + + align:start position:0% +when things are slow or when things fail + + + align:start position:0% +when things are slow or when things fail +so being in control of that timing is + + align:start position:0% +so being in control of that timing is + + + align:start position:0% +so being in control of that timing is +crucial we do have some variations on + + align:start position:0% +crucial we do have some variations on + + + align:start position:0% +crucial we do have some variations on +this activity though one of our + + align:start position:0% +this activity though one of our + + + align:start position:0% +this activity though one of our +instructors this year had students count + + align:start position:0% +instructors this year had students count + + + align:start position:0% +instructors this year had students count +characters instead of words same idea + + align:start position:0% +characters instead of words same idea + + + align:start position:0% +characters instead of words same idea +but he had one of the one of the workers + + align:start position:0% +but he had one of the one of the workers + + + align:start position:0% +but he had one of the one of the workers +was counting Russian characters instead + + align:start position:0% +was counting Russian characters instead + + + align:start position:0% +was counting Russian characters instead +of English so they just organically were + + align:start position:0% +of English so they just organically were + + + align:start position:0% +of English so they just organically were +much slower than the rest of the class + + align:start position:0% +much slower than the rest of the class + + + align:start position:0% +much slower than the rest of the class +that was kind of a nice way to show that + + align:start position:0% +that was kind of a nice way to show that + + + align:start position:0% +that was kind of a nice way to show that +many of our instructors have the + + align:start position:0% +many of our instructors have the + + + align:start position:0% +many of our instructors have the +students count types of candy instead of + + align:start position:0% +students count types of candy instead of + + + align:start position:0% +students count types of candy instead of +words and we bring them candy that's a + + align:start position:0% +words and we bring them candy that's a + + + align:start position:0% +words and we bring them candy that's a +big hit in fact after we did this + + align:start position:0% +big hit in fact after we did this + + + align:start position:0% +big hit in fact after we did this +recitation this year one of our students + + align:start position:0% +recitation this year one of our students + + + align:start position:0% +recitation this year one of our students +asked why can't every recitation feel + + align:start position:0% +asked why can't every recitation feel + + + align:start position:0% +asked why can't every recitation feel +like the MapReduce one is not clear how + + align:start position:0% +like the MapReduce one is not clear how + + + align:start position:0% +like the MapReduce one is not clear how +much the candy factored into that + + align:start position:0% +much the candy factored into that + + + align:start position:0% +much the candy factored into that +question so it has taken us quite a few + + align:start position:0% +question so it has taken us quite a few + + + align:start position:0% +question so it has taken us quite a few +iterations to get that activity working + + align:start position:0% +iterations to get that activity working + + + align:start position:0% +iterations to get that activity working +and again I know you're not all teaching + + align:start position:0% +and again I know you're not all teaching + + + align:start position:0% +and again I know you're not all teaching +MapReduce in your courses you're not + + align:start position:0% +MapReduce in your courses you're not + + + align:start position:0% +MapReduce in your courses you're not +going to take that activity at you but + + align:start position:0% +going to take that activity at you but + + + align:start position:0% +going to take that activity at you but +the things that were interesting for us + + align:start position:0% +the things that were interesting for us + + + align:start position:0% +the things that were interesting for us +having the students in teams for each of + + align:start position:0% +having the students in teams for each of + + + align:start position:0% +having the students in teams for each of +these roles made a huge difference both + + align:start position:0% +these roles made a huge difference both + + + align:start position:0% +these roles made a huge difference both +in terms of making sure they were all + + align:start position:0% +in terms of making sure they were all + + + align:start position:0% +in terms of making sure they were all +doing the correct things but just + + align:start position:0% +doing the correct things but just + + + align:start position:0% +doing the correct things but just +getting them more comfortable with it I + + align:start position:0% +getting them more comfortable with it I + + + align:start position:0% +getting them more comfortable with it I +will tell you the students go for this + + align:start position:0% +will tell you the students go for this + + + align:start position:0% +will tell you the students go for this +they are into it they map and reduce + + align:start position:0% +they are into it they map and reduce + + + align:start position:0% +they are into it they map and reduce +they do not think it's stupid which is + + align:start position:0% +they do not think it's stupid which is + + + align:start position:0% +they do not think it's stupid which is +very very nice um and you know making + + align:start position:0% +very very nice um and you know making + + + align:start position:0% +very very nice um and you know making +sure that the master has these + + align:start position:0% +sure that the master has these + + + align:start position:0% +sure that the master has these +exceedingly detailed instructions + + align:start position:0% +exceedingly detailed instructions + + + align:start position:0% +exceedingly detailed instructions +figuring out how to make the timing work + + align:start position:0% +figuring out how to make the timing work + + + align:start position:0% +figuring out how to make the timing work +so that all of the things we wanted to + + align:start position:0% +so that all of the things we wanted to + + + align:start position:0% +so that all of the things we wanted to +discuss would actually happen and so + + align:start position:0% +discuss would actually happen and so + + + align:start position:0% +discuss would actually happen and so +really the activity is the way I + + align:start position:0% +really the activity is the way I + + + align:start position:0% +really the activity is the way I +described it Karen this is how Karen + + align:start position:0% +described it Karen this is how Karen + + + align:start position:0% +described it Karen this is how Karen +does it I carry near the authoritative + + align:start position:0% +does it I carry near the authoritative + + + align:start position:0% +does it I carry near the authoritative +source on how we do Map Reduce + + align:start position:0% +source on how we do Map Reduce + + + align:start position:0% +source on how we do Map Reduce +yeah um I wanted to talk briefly about + + align:start position:0% +yeah um I wanted to talk briefly about + + + align:start position:0% +yeah um I wanted to talk briefly about +another system we act out because it's + + align:start position:0% +another system we act out because it's + + + align:start position:0% +another system we act out because it's +fun it's one of my favorite things that + + align:start position:0% +fun it's one of my favorite things that + + + align:start position:0% +fun it's one of my favorite things that +we do it's much shorter we do this for a + + align:start position:0% +we do it's much shorter we do this for a + + + align:start position:0% +we do it's much shorter we do this for a +system called a raft and raft like + + align:start position:0% +system called a raft and raft like + + + align:start position:0% +system called a raft and raft like +MapReduce is this large distributed + + align:start position:0% +MapReduce is this large distributed + + + align:start position:0% +MapReduce is this large distributed +system a lot of machines timing is also + + align:start position:0% +system a lot of machines timing is also + + + align:start position:0% +system a lot of machines timing is also +important in raft in particular machines + + align:start position:0% +important in raft in particular machines + + + align:start position:0% +important in raft in particular machines +set randomized timers I pick some random + + align:start position:0% +set randomized timers I pick some random + + + align:start position:0% +set randomized timers I pick some random +number of you know seconds milliseconds + + align:start position:0% +number of you know seconds milliseconds + + + align:start position:0% +number of you know seconds milliseconds +or whatever the and when that timer + + align:start position:0% +or whatever the and when that timer + + + align:start position:0% +or whatever the and when that timer +expires they do something so being able + + align:start position:0% +expires they do something so being able + + + align:start position:0% +expires they do something so being able +to act that out is actually really + + align:start position:0% +to act that out is actually really + + + align:start position:0% +to act that out is actually really +crucial and we thought like gosh how are + + align:start position:0% +crucial and we thought like gosh how are + + + align:start position:0% +crucial and we thought like gosh how are +we gonna randomize them and so one of my + + align:start position:0% +we gonna randomize them and so one of my + + + align:start position:0% +we gonna randomize them and so one of my +instructors came up with the best idea + + align:start position:0% +instructors came up with the best idea + + + align:start position:0% +instructors came up with the best idea +which is to have the students spin + + align:start position:0% +which is to have the students spin + + + align:start position:0% +which is to have the students spin +around in a circle so like literally + + align:start position:0% +around in a circle so like literally + + + align:start position:0% +around in a circle so like literally +standing here and then they kind of they + + align:start position:0% +standing here and then they kind of they + + + align:start position:0% +standing here and then they kind of they +do this and it takes a while because you + + align:start position:0% +do this and it takes a while because you + + + align:start position:0% +do this and it takes a while because you +figured out that students just walk + + align:start position:0% +figured out that students just walk + + + align:start position:0% +figured out that students just walk +around naturally at different paces so + + align:start position:0% +around naturally at different paces so + + + align:start position:0% +around naturally at different paces so +they've effectively randomized + + align:start position:0% +they've effectively randomized + + + align:start position:0% +they've effectively randomized +themselves someone will finish first so + + align:start position:0% +themselves someone will finish first so + + + align:start position:0% +themselves someone will finish first so +I need you to imagine you get like + + align:start position:0% +I need you to imagine you get like + + + align:start position:0% +I need you to imagine you get like +you're walking around MIT and there's + + align:start position:0% +you're walking around MIT and there's + + + align:start position:0% +you're walking around MIT and there's +corn in this class and you see seven or + + align:start position:0% +corn in this class and you see seven or + + + align:start position:0% +corn in this class and you see seven or +eight students up at the front of the + + align:start position:0% +eight students up at the front of the + + + align:start position:0% +eight students up at the front of the +room just very quietly spinning around + + align:start position:0% +room just very quietly spinning around + + + align:start position:0% +room just very quietly spinning around +in place while all of the other students + + align:start position:0% +in place while all of the other students + + + align:start position:0% +in place while all of the other students +are like because the person who finishes + + align:start position:0% +are like because the person who finishes + + + align:start position:0% +are like because the person who finishes +first wins and so who's like who is it + + align:start position:0% +first wins and so who's like who is it + + + align:start position:0% +first wins and so who's like who is it +who's gonna be the next leader of this + + align:start position:0% +who's gonna be the next leader of this + + + align:start position:0% +who's gonna be the next leader of this +election cycle and Raft it's really it + + align:start position:0% +election cycle and Raft it's really it + + + align:start position:0% +election cycle and Raft it's really it +looks ridiculous but it works so well + + align:start position:0% +looks ridiculous but it works so well + + + align:start position:0% +looks ridiculous but it works so well +and I just it brings me a lot of joy + + align:start position:0% +and I just it brings me a lot of joy + + + align:start position:0% +and I just it brings me a lot of joy +uh-huh so to kind of you know wrap up + + align:start position:0% +uh-huh so to kind of you know wrap up + + + align:start position:0% +uh-huh so to kind of you know wrap up +our activities before I get to you + + align:start position:0% +our activities before I get to you + + + align:start position:0% +our activities before I get to you +results effectively has this worked for + + align:start position:0% +results effectively has this worked for + + + align:start position:0% +results effectively has this worked for +us again we do all of these things a lot + + align:start position:0% +us again we do all of these things a lot + + + align:start position:0% +us again we do all of these things a lot +this one in particular small groups to a + + align:start position:0% +this one in particular small groups to a + + + align:start position:0% +this one in particular small groups to a +classified discussion although acting + + align:start position:0% +classified discussion although acting + + + align:start position:0% +classified discussion although acting +things out we act a lot of things out + + align:start position:0% +things out we act a lot of things out + + + align:start position:0% +things out we act a lot of things out +now we've gotten pretty good at that and + + align:start position:0% +now we've gotten pretty good at that and + + + align:start position:0% +now we've gotten pretty good at that and +the key component for us has been + + align:start position:0% +the key component for us has been + + + align:start position:0% +the key component for us has been +recognizing you know in all of these + + align:start position:0% +recognizing you know in all of these + + + align:start position:0% +recognizing you know in all of these +cases the students are more comfortable + + align:start position:0% +cases the students are more comfortable + + + align:start position:0% +cases the students are more comfortable +if they're not doing something alone if + + align:start position:0% +if they're not doing something alone if + + + align:start position:0% +if they're not doing something alone if +they have at least one other person on + + align:start position:0% +they have at least one other person on + + + align:start position:0% +they have at least one other person on +their team + + align:start position:0% +their team + + + align:start position:0% +their team +doing whatever it is they need to do in + + align:start position:0% +doing whatever it is they need to do in + + + align:start position:0% +doing whatever it is they need to do in +that recitation in the sense we do + + align:start position:0% +that recitation in the sense we do + + + align:start position:0% +that recitation in the sense we do +something like this in every recitation + + align:start position:0% +something like this in every recitation + + + align:start position:0% +something like this in every recitation +the students just come to expect it I + + align:start position:0% +the students just come to expect it I + + + align:start position:0% +the students just come to expect it I +mean they go for it sometimes you know + + align:start position:0% +mean they go for it sometimes you know + + + align:start position:0% +mean they go for it sometimes you know +I'll come in and cover a recitation and + + align:start position:0% +I'll come in and cover a recitation and + + + align:start position:0% +I'll come in and cover a recitation and +you know despite observations I'm never + + align:start position:0% +you know despite observations I'm never + + + align:start position:0% +you know despite observations I'm never +exactly sure how my instructors are + + align:start position:0% +exactly sure how my instructors are + + + align:start position:0% +exactly sure how my instructors are +leaving things I so I always start by + + align:start position:0% +leaving things I so I always start by + + + align:start position:0% +leaving things I so I always start by +asking like you know hey I'm gonna I'm + + align:start position:0% +asking like you know hey I'm gonna I'm + + + align:start position:0% +asking like you know hey I'm gonna I'm +gonna put you all in groups is that is + + align:start position:0% +gonna put you all in groups is that is + + + align:start position:0% +gonna put you all in groups is that is +that something you're used to every time + + align:start position:0% +that something you're used to every time + + + align:start position:0% +that something you're used to every time +they're like yeah we do that every day + + align:start position:0% +they're like yeah we do that every day + + + align:start position:0% +they're like yeah we do that every day +like of course we can get into groups um + + align:start position:0% +like of course we can get into groups um + + + align:start position:0% +like of course we can get into groups um +so again even acting things out they + + align:start position:0% +so again even acting things out they + + + align:start position:0% +so again even acting things out they +really go for it we try to vary the + + align:start position:0% +really go for it we try to vary the + + + align:start position:0% +really go for it we try to vary the +types of activities that we do each week + + align:start position:0% +types of activities that we do each week + + + align:start position:0% +types of activities that we do each week +to keep everyone engaged to keep things + + align:start position:0% +to keep everyone engaged to keep things + + + align:start position:0% +to keep everyone engaged to keep things +interesting it's hard to act every + + align:start position:0% +interesting it's hard to act every + + + align:start position:0% +interesting it's hard to act every +single every system out uh and you know + + align:start position:0% +single every system out uh and you know + + + align:start position:0% +single every system out uh and you know +there's occasions where an activity + + align:start position:0% +there's occasions where an activity + + + align:start position:0% +there's occasions where an activity +doesn't work the first time we tried + + align:start position:0% +doesn't work the first time we tried + + + align:start position:0% +doesn't work the first time we tried +MapReduce it was chaos but you know we + + align:start position:0% +MapReduce it was chaos but you know we + + + align:start position:0% +MapReduce it was chaos but you know we +thought it was a cool thing so we just + + align:start position:0% +thought it was a cool thing so we just + + + align:start position:0% +thought it was a cool thing so we just +iterated we just tried it again the next + + align:start position:0% +iterated we just tried it again the next + + + align:start position:0% +iterated we just tried it again the next +semester and in planning all of these + + align:start position:0% +semester and in planning all of these + + + align:start position:0% +semester and in planning all of these +we're so very careful to make sure that + + align:start position:0% +we're so very careful to make sure that + + + align:start position:0% +we're so very careful to make sure that +our activities actually teach them + + align:start position:0% +our activities actually teach them + + + align:start position:0% +our activities actually teach them +things right you know like I said all of + + align:start position:0% +things right you know like I said all of + + + align:start position:0% +things right you know like I said all of +the recitations have technical points + + align:start position:0% +the recitations have technical points + + + align:start position:0% +the recitations have technical points +that they have to hit on a MapReduce + + align:start position:0% +that they have to hit on a MapReduce + + + align:start position:0% +that they have to hit on a MapReduce +activity where they just act out this + + align:start position:0% +activity where they just act out this + + + align:start position:0% +activity where they just act out this +system in its normal use case it would + + align:start position:0% +system in its normal use case it would + + + align:start position:0% +system in its normal use case it would +be fun but they're supposed to come in + + align:start position:0% +be fun but they're supposed to come in + + + align:start position:0% +be fun but they're supposed to come in +knowing that so we really want to design + + align:start position:0% +knowing that so we really want to design + + + align:start position:0% +knowing that so we really want to design +these activities so that we're hitting + + align:start position:0% +these activities so that we're hitting + + + align:start position:0% +these activities so that we're hitting +on the points we need to hit on so there + + align:start position:0% +on the points we need to hit on so there + + + align:start position:0% +on the points we need to hit on so there +is a lot of plenty that goes into this + + align:start position:0% +is a lot of plenty that goes into this + + + align:start position:0% +is a lot of plenty that goes into this +so now for the final part did it work + + align:start position:0% +so now for the final part did it work + + + align:start position:0% +so now for the final part did it work +right what got better I'll start with a + + align:start position:0% +right what got better I'll start with a + + + align:start position:0% +right what got better I'll start with a +few actually quantitative things + + align:start position:0% +few actually quantitative things + + + align:start position:0% +few actually quantitative things +sometimes when I tell people about this + + align:start position:0% +sometimes when I tell people about this + + + align:start position:0% +sometimes when I tell people about this +endeavor you know they're they want to + + align:start position:0% +endeavor you know they're they want to + + + align:start position:0% +endeavor you know they're they want to +know our grades better are the heads of + + align:start position:0% +know our grades better are the heads of + + + align:start position:0% +know our grades better are the heads of +students grades improved how are they + + align:start position:0% +students grades improved how are they + + + align:start position:0% +students grades improved how are they +during exams I don't personally think + + align:start position:0% +during exams I don't personally think + + + align:start position:0% +during exams I don't personally think +that that's the right question there is + + align:start position:0% +that that's the right question there is + + + align:start position:0% +that that's the right question there is +one aspect of grading that has improved + + align:start position:0% +one aspect of grading that has improved + + + align:start position:0% +one aspect of grading that has improved +participation grades we assign a pretty + + align:start position:0% +participation grades we assign a pretty + + + align:start position:0% +participation grades we assign a pretty +large portion of the final grade to + + align:start position:0% +large portion of the final grade to + + + align:start position:0% +large portion of the final grade to +participation in recitation again we're + + align:start position:0% +participation in recitation again we're + + + align:start position:0% +participation in recitation again we're +asking a lot of them we're expecting + + align:start position:0% +asking a lot of them we're expecting + + + align:start position:0% +asking a lot of them we're expecting +them to demonstrate certain skills and + + align:start position:0% +them to demonstrate certain skills and + + + align:start position:0% +them to demonstrate certain skills and +recitation so they are graded + + align:start position:0% +recitation so they are graded + + + align:start position:0% +recitation so they are graded +accordingly and we're seeing students + + align:start position:0% +accordingly and we're seeing students + + + align:start position:0% +accordingly and we're seeing students +earn higher participation grades now um + + align:start position:0% +earn higher participation grades now um + + + align:start position:0% +earn higher participation grades now um +comfortable interpreting that as they + + align:start position:0% +comfortable interpreting that as they + + + align:start position:0% +comfortable interpreting that as they +are participating more we are also + + align:start position:0% +are participating more we are also + + + align:start position:0% +are participating more we are also +giving them a lot more opportunities to + + align:start position:0% +giving them a lot more opportunities to + + + align:start position:0% +giving them a lot more opportunities to +participate related to that one of the + + align:start position:0% +participate related to that one of the + + + align:start position:0% +participate related to that one of the +things that we've gained from this + + align:start position:0% +things that we've gained from this + + + align:start position:0% +things that we've gained from this +experience is just a better + + align:start position:0% +experience is just a better + + + align:start position:0% +experience is just a better +understanding of what it means to + + align:start position:0% +understanding of what it means to + + + align:start position:0% +understanding of what it means to +participate in our class and for a long + + align:start position:0% +participate in our class and for a long + + + align:start position:0% +participate in our class and for a long +time to us you know what kind of men + + align:start position:0% +time to us you know what kind of men + + + align:start position:0% +time to us you know what kind of men +well does this student answer questions + + align:start position:0% +well does this student answer questions + + + align:start position:0% +well does this student answer questions +when I ask them a question but now it + + align:start position:0% +when I ask them a question but now it + + + align:start position:0% +when I ask them a question but now it +means are they coming prepared to class + + align:start position:0% +means are they coming prepared to class + + + align:start position:0% +means are they coming prepared to class +are they engaged in group work are they + + align:start position:0% +are they engaged in group work are they + + + align:start position:0% +are they engaged in group work are they +listening to other students into their + + align:start position:0% +listening to other students into their + + + align:start position:0% +listening to other students into their +instructor are they participating in + + align:start position:0% +instructor are they participating in + + + align:start position:0% +instructor are they participating in +class pride discussions there's more + + align:start position:0% +class pride discussions there's more + + + align:start position:0% +class pride discussions there's more +opportunities for students to + + align:start position:0% +opportunities for students to + + + align:start position:0% +opportunities for students to +participate we are much clearer about + + align:start position:0% +participate we are much clearer about + + + align:start position:0% +participate we are much clearer about +how we assign this grade is they're not + + align:start position:0% +how we assign this grade is they're not + + + align:start position:0% +how we assign this grade is they're not +only have the grades improved but the + + align:start position:0% +only have the grades improved but the + + + align:start position:0% +only have the grades improved but the +students are noticeably more noticeably + + align:start position:0% +students are noticeably more noticeably + + + align:start position:0% +students are noticeably more noticeably +more relaxed about this grade I get + + align:start position:0% +more relaxed about this grade I get + + + align:start position:0% +more relaxed about this grade I get +fewer complaints about this grade which + + align:start position:0% +fewer complaints about this grade which + + + align:start position:0% +fewer complaints about this grade which +is great for me and you know they know + + align:start position:0% +is great for me and you know they know + + + align:start position:0% +is great for me and you know they know +that if they come prepared and ready to + + align:start position:0% +that if they come prepared and ready to + + + align:start position:0% +that if they come prepared and ready to +do the work they'll be fine I've been + + align:start position:0% +do the work they'll be fine I've been + + + align:start position:0% +do the work they'll be fine I've been +part of the final grading divorce it's a + + align:start position:0% +part of the final grading divorce it's a + + + align:start position:0% +part of the final grading divorce it's a +percentage of the final grade is from + + align:start position:0% +percentage of the final grade is from + + + align:start position:0% +percentage of the final grade is from +participation recitation so we also + + align:start position:0% +participation recitation so we also + + + align:start position:0% +participation recitation so we also +surveyed the students during the + + align:start position:0% +surveyed the students during the + + + align:start position:0% +surveyed the students during the +semester and we were largely asking + + align:start position:0% +semester and we were largely asking + + + align:start position:0% +semester and we were largely asking +questions about you know do you feel + + align:start position:0% +questions about you know do you feel + + + align:start position:0% +questions about you know do you feel +comfortable in the recitations I largely + + align:start position:0% +comfortable in the recitations I largely + + + align:start position:0% +comfortable in the recitations I largely +yes they did in our final survey + + align:start position:0% +yes they did in our final survey + + + align:start position:0% +yes they did in our final survey +overwhelmingly the students felt that + + align:start position:0% +overwhelmingly the students felt that + + + align:start position:0% +overwhelmingly the students felt that +these activities improved their + + align:start position:0% +these activities improved their + + + align:start position:0% +these activities improved their +engagement so you know these things are + + align:start position:0% +engagement so you know these things are + + + align:start position:0% +engagement so you know these things are +all good I don't think that they really + + align:start position:0% +all good I don't think that they really + + + align:start position:0% +all good I don't think that they really +capture though what has been so great + + align:start position:0% +capture though what has been so great + + + align:start position:0% +capture though what has been so great +about this endeavor for our class and so + + align:start position:0% +about this endeavor for our class and so + + + align:start position:0% +about this endeavor for our class and so +I you know in preparing this talk I + + align:start position:0% +I you know in preparing this talk I + + + align:start position:0% +I you know in preparing this talk I +spoke to a couple of instructors who + + align:start position:0% +spoke to a couple of instructors who + + + align:start position:0% +spoke to a couple of instructors who +have been with me for a number of years + + align:start position:0% +have been with me for a number of years + + + align:start position:0% +have been with me for a number of years +so they've seen the class through it's + + align:start position:0% +so they've seen the class through it's + + + align:start position:0% +so they've seen the class through it's +non active learning era through the dark + + align:start position:0% +non active learning era through the dark + + + align:start position:0% +non active learning era through the dark +times as well as the current era and so + + align:start position:0% +times as well as the current era and so + + + align:start position:0% +times as well as the current era and so +I you know I have I saw a few quotes + + align:start position:0% +I you know I have I saw a few quotes + + + align:start position:0% +I you know I have I saw a few quotes +from them to kind of + + align:start position:0% +from them to kind of + + + align:start position:0% +from them to kind of +what I think has made this approach + + align:start position:0% +what I think has made this approach + + + align:start position:0% +what I think has made this approach +better for the students so it's our + + align:start position:0% +better for the students so it's our + + + align:start position:0% +better for the students so it's our +number one the first is that I think the + + align:start position:0% +number one the first is that I think the + + + align:start position:0% +number one the first is that I think the +students actually understand the + + align:start position:0% +students actually understand the + + + align:start position:0% +students actually understand the +algorithms better in particular if we're + + align:start position:0% +algorithms better in particular if we're + + + align:start position:0% +algorithms better in particular if we're +acting something out it gives them a + + align:start position:0% +acting something out it gives them a + + + align:start position:0% +acting something out it gives them a +visceral experience of the finer points + + align:start position:0% +visceral experience of the finer points + + + align:start position:0% +visceral experience of the finer points +and edge conditions it's really easy to + + align:start position:0% +and edge conditions it's really easy to + + + align:start position:0% +and edge conditions it's really easy to +slide over things if one reads a paper + + align:start position:0% +slide over things if one reads a paper + + + align:start position:0% +slide over things if one reads a paper +quickly and we're asking them to read a + + align:start position:0% +quickly and we're asking them to read a + + + align:start position:0% +quickly and we're asking them to read a +lot second instructor I think that it's + + align:start position:0% +lot second instructor I think that it's + + + align:start position:0% +lot second instructor I think that it's +much better where there are pairs + + align:start position:0% +much better where there are pairs + + + align:start position:0% +much better where there are pairs +discussing the solution or when we're + + align:start position:0% +discussing the solution or when we're + + + align:start position:0% +discussing the solution or when we're +doing a game people are more likely to + + align:start position:0% +doing a game people are more likely to + + + align:start position:0% +doing a game people are more likely to +notice a flaw and something I've said + + align:start position:0% +notice a flaw and something I've said + + + align:start position:0% +notice a flaw and something I've said +earn someone else's answer and they ask + + align:start position:0% +earn someone else's answer and they ask + + + align:start position:0% +earn someone else's answer and they ask +better questions plus I think it's + + align:start position:0% +better questions plus I think it's + + + align:start position:0% +better questions plus I think it's +reassuring either to find out that a + + align:start position:0% +reassuring either to find out that a + + + align:start position:0% +reassuring either to find out that a +classmate is just as confused or to find + + align:start position:0% +classmate is just as confused or to find + + + align:start position:0% +classmate is just as confused or to find +out that a classmate knows a ton about + + align:start position:0% +out that a classmate knows a ton about + + + align:start position:0% +out that a classmate knows a ton about +the subject and then the last one which + + align:start position:0% +the subject and then the last one which + + + align:start position:0% +the subject and then the last one which +I think really sums up how things have + + align:start position:0% +I think really sums up how things have + + + align:start position:0% +I think really sums up how things have +been for our students is this one I + + align:start position:0% +been for our students is this one I + + + align:start position:0% +been for our students is this one I +think the students are more engaged + + align:start position:0% +think the students are more engaged + + + align:start position:0% +think the students are more engaged +because they are asked to be more active + + align:start position:0% +because they are asked to be more active + + + align:start position:0% +because they are asked to be more active +participants there's a greater sense of + + align:start position:0% +participants there's a greater sense of + + + align:start position:0% +participants there's a greater sense of +camaraderie between them because of + + align:start position:0% +camaraderie between them because of + + + align:start position:0% +camaraderie between them because of +their interactions so you know we're + + align:start position:0% +their interactions so you know we're + + + align:start position:0% +their interactions so you know we're +seeing these students understanding the + + align:start position:0% +seeing these students understanding the + + + align:start position:0% +seeing these students understanding the +details of the system's better while + + align:start position:0% +details of the system's better while + + + align:start position:0% +details of the system's better while +developing this sense of camaraderie and + + align:start position:0% +developing this sense of camaraderie and + + + align:start position:0% +developing this sense of camaraderie and +honestly that has been huge for us + + align:start position:0% +honestly that has been huge for us + + + align:start position:0% +honestly that has been huge for us +largely I would say from my perspective + + align:start position:0% +largely I would say from my perspective + + + align:start position:0% +largely I would say from my perspective +as the person in charge students are + + align:start position:0% +as the person in charge students are + + + align:start position:0% +as the person in charge students are +buying into this class more than they + + align:start position:0% +buying into this class more than they + + + align:start position:0% +buying into this class more than they +used to + + align:start position:0% +used to + + + align:start position:0% +used to +I get fewer complaints across the board + + align:start position:0% +I get fewer complaints across the board + + + align:start position:0% +I get fewer complaints across the board +we're seeing them work better together + + align:start position:0% +we're seeing them work better together + + + align:start position:0% +we're seeing them work better together +in their team projects we're seeing them + + align:start position:0% +in their team projects we're seeing them + + + align:start position:0% +in their team projects we're seeing them +be more engaged in lecture and in + + align:start position:0% +be more engaged in lecture and in + + + align:start position:0% +be more engaged in lecture and in +tutorial even though recitations was + + align:start position:0% +tutorial even though recitations was + + + align:start position:0% +tutorial even though recitations was +really where this active learning push + + align:start position:0% +really where this active learning push + + + align:start position:0% +really where this active learning push +happened and this whole thing has been + + align:start position:0% +happened and this whole thing has been + + + align:start position:0% +happened and this whole thing has been +beneficial not just for the students but + + align:start position:0% +beneficial not just for the students but + + + align:start position:0% +beneficial not just for the students but +also for the staff right you know there + + align:start position:0% +also for the staff right you know there + + + align:start position:0% +also for the staff right you know there +was a little hesitant at first active + + align:start position:0% +was a little hesitant at first active + + + align:start position:0% +was a little hesitant at first active +learning can be a hard sell it involves + + align:start position:0% +learning can be a hard sell it involves + + + align:start position:0% +learning can be a hard sell it involves +more work for everyone it takes a lot of + + align:start position:0% +more work for everyone it takes a lot of + + + align:start position:0% +more work for everyone it takes a lot of +planning it can be a nerve-wracking way + + align:start position:0% +planning it can be a nerve-wracking way + + + align:start position:0% +planning it can be a nerve-wracking way +to teach if you've never taught it + + align:start position:0% +to teach if you've never taught it + + + align:start position:0% +to teach if you've never taught it +before if imagine coming into a room of + + align:start position:0% +before if imagine coming into a room of + + + align:start position:0% +before if imagine coming into a room of +students you don't know very well and + + align:start position:0% +students you don't know very well and + + + align:start position:0% +students you don't know very well and +say okay five of you are gonna be on the + + align:start position:0% +say okay five of you are gonna be on the + + + align:start position:0% +say okay five of you are gonna be on the +master team let's go I made you all hats + + align:start position:0% +master team let's go I made you all hats + + + align:start position:0% +master team let's go I made you all hats +right but now we have that you know one + + align:start position:0% +right but now we have that you know one + + + align:start position:0% +right but now we have that you know one +of my instructors says there's a modest + + align:start position:0% +of my instructors says there's a modest + + + align:start position:0% +of my instructors says there's a modest +amount of competition among the + + align:start position:0% +amount of competition among the + + + align:start position:0% +amount of competition among the +recitation instructors to work out + + align:start position:0% +recitation instructors to work out + + + align:start position:0% +recitation instructors to work out +schemes and games so it feels like + + align:start position:0% +schemes and games so it feels like + + + align:start position:0% +schemes and games so it feels like +there's both a reward for applying + + align:start position:0% +there's both a reward for applying + + + align:start position:0% +there's both a reward for applying +myself but there's also less need for + + align:start position:0% +myself but there's also less need for + + + align:start position:0% +myself but there's also less need for +perfection it's helped that we're + + align:start position:0% +perfection it's helped that we're + + + align:start position:0% +perfection it's helped that we're +encouraging active learning as an + + align:start position:0% +encouraging active learning as an + + + align:start position:0% +encouraging active learning as an +approach + + align:start position:0% +approach + + + align:start position:0% +approach +because it makes it feel like less of a + + align:start position:0% +because it makes it feel like less of a + + + align:start position:0% +because it makes it feel like less of a +risk for me to try some new + + align:start position:0% +risk for me to try some new + + + align:start position:0% +risk for me to try some new +unconventional approach that occurs to + + align:start position:0% +unconventional approach that occurs to + + + align:start position:0% +unconventional approach that occurs to +me so I'll tell you one of the + + align:start position:0% +me so I'll tell you one of the + + + align:start position:0% +me so I'll tell you one of the +highlights for me as a person sort of + + align:start position:0% +highlights for me as a person sort of + + + align:start position:0% +highlights for me as a person sort of +overseeing this operation so this + + align:start position:0% +overseeing this operation so this + + + align:start position:0% +overseeing this operation so this +happened at the end of last semester + + align:start position:0% +happened at the end of last semester + + + align:start position:0% +happened at the end of last semester +this is again that's the first time + + align:start position:0% +this is again that's the first time + + + align:start position:0% +this is again that's the first time +we're really putting this scheme into + + align:start position:0% +we're really putting this scheme into + + + align:start position:0% +we're really putting this scheme into +place and near the end my instructors I + + align:start position:0% +place and near the end my instructors I + + + align:start position:0% +place and near the end my instructors I +got this email fare from the instructors + + align:start position:0% +got this email fare from the instructors + + + align:start position:0% +got this email fare from the instructors +about one of the final recitations and + + align:start position:0% +about one of the final recitations and + + + align:start position:0% +about one of the final recitations and +the recitation was about a system called + + align:start position:0% +the recitation was about a system called + + + align:start position:0% +the recitation was about a system called +DNS SEC secure DNS so it deals with + + align:start position:0% +DNS SEC secure DNS so it deals with + + + align:start position:0% +DNS SEC secure DNS so it deals with +security DNS SEC prevents certain types + + align:start position:0% +security DNS SEC prevents certain types + + + align:start position:0% +security DNS SEC prevents certain types +of attacks on a system called DNS that's + + align:start position:0% +of attacks on a system called DNS that's + + + align:start position:0% +of attacks on a system called DNS that's +all you need to know about DNS SEC so + + align:start position:0% +all you need to know about DNS SEC so + + + align:start position:0% +all you need to know about DNS SEC so +the first instructor described an + + align:start position:0% +the first instructor described an + + + align:start position:0% +the first instructor described an +activity they had done where they had + + align:start position:0% +activity they had done where they had + + + align:start position:0% +activity they had done where they had +groups draw diagrams of their attacks on + + align:start position:0% +groups draw diagrams of their attacks on + + + align:start position:0% +groups draw diagrams of their attacks on +the board in parallel and then talk + + align:start position:0% +the board in parallel and then talk + + + align:start position:0% +the board in parallel and then talk +through each diagram with the students + + align:start position:0% +through each diagram with the students + + + align:start position:0% +through each diagram with the students +explaining the problems and the approach + + align:start position:0% +explaining the problems and the approach + + + align:start position:0% +explaining the problems and the approach +ins approaches an instructor noted that + + align:start position:0% +ins approaches an instructor noted that + + + align:start position:0% +ins approaches an instructor noted that +were they engaged they laughed they + + align:start position:0% +were they engaged they laughed they + + + align:start position:0% +were they engaged they laughed they +collaborated they learned more about how + + align:start position:0% +collaborated they learned more about how + + + align:start position:0% +collaborated they learned more about how +to design figures to tell the story they + + align:start position:0% +to design figures to tell the story they + + + align:start position:0% +to design figures to tell the story they +wanted to tell and I got this email and + + align:start position:0% +wanted to tell and I got this email and + + + align:start position:0% +wanted to tell and I got this email and +I was so excited because this is not an + + align:start position:0% +I was so excited because this is not an + + + align:start position:0% +I was so excited because this is not an +activity that I had planed for them this + + align:start position:0% +activity that I had planed for them this + + + align:start position:0% +activity that I had planed for them this +is just something they had done and I + + align:start position:0% +is just something they had done and I + + + align:start position:0% +is just something they had done and I +thought what's happened finally it's + + align:start position:0% +thought what's happened finally it's + + + align:start position:0% +thought what's happened finally it's +happened and then I guess they can email + + align:start position:0% +happened and then I guess they can email + + + align:start position:0% +happened and then I guess they can email +so a second is start to responded saying + + align:start position:0% +so a second is start to responded saying + + + align:start position:0% +so a second is start to responded saying +that you know that sounded great and + + align:start position:0% +that you know that sounded great and + + + align:start position:0% +that you know that sounded great and +what they had done they'd had a group of + + align:start position:0% +what they had done they'd had a group of + + + align:start position:0% +what they had done they'd had a group of +students work out how DNS would work for + + align:start position:0% +students work out how DNS would work for + + + align:start position:0% +students work out how DNS would work for +a particular scenario so the original + + align:start position:0% +a particular scenario so the original + + + align:start position:0% +a particular scenario so the original +system and then two additional groups + + align:start position:0% +system and then two additional groups + + + align:start position:0% +system and then two additional groups +joined that first group worked through + + align:start position:0% +joined that first group worked through + + + align:start position:0% +joined that first group worked through +how different attacks would affect that + + align:start position:0% +how different attacks would affect that + + + align:start position:0% +how different attacks would affect that +scenario and then a fourth group acted + + align:start position:0% +scenario and then a fourth group acted + + + align:start position:0% +scenario and then a fourth group acted +as DNS SEC and explained how DNS SEC + + align:start position:0% +as DNS SEC and explained how DNS SEC + + + align:start position:0% +as DNS SEC and explained how DNS SEC +would prevent such attacks so ah + + align:start position:0% +would prevent such attacks so ah + + + align:start position:0% +would prevent such attacks so ah +two brand-new ideas both really good + + align:start position:0% +two brand-new ideas both really good + + + align:start position:0% +two brand-new ideas both really good +both really different this was so + + align:start position:0% +both really different this was so + + + align:start position:0% +both really different this was so +exciting and then we get Sur instructor + + align:start position:0% +exciting and then we get Sur instructor + + + align:start position:0% +exciting and then we get Sur instructor +number three and I've never been able to + + align:start position:0% +number three and I've never been able to + + + align:start position:0% +number three and I've never been able to +figure out a way to summarize this email + + align:start position:0% +figure out a way to summarize this email + + + align:start position:0% +figure out a way to summarize this email +so I have to quote him for you directly + + align:start position:0% +so I have to quote him for you directly + + + align:start position:0% +so I have to quote him for you directly +in my recitation we had a marriage + + align:start position:0% +in my recitation we had a marriage + + + align:start position:0% +in my recitation we had a marriage +proposal that went bad when a romantic + + align:start position:0% +proposal that went bad when a romantic + + + align:start position:0% +proposal that went bad when a romantic +rival wants tan attack to destroy the + + align:start position:0% +rival wants tan attack to destroy the + + + align:start position:0% +rival wants tan attack to destroy the +relationship a second group used a + + align:start position:0% +relationship a second group used a + + + align:start position:0% +relationship a second group used a +different attack to induce peasants to + + align:start position:0% +different attack to induce peasants to + + + align:start position:0% +different attack to induce peasants to +send their taxes to a skimmer all of + + align:start position:0% +send their taxes to a skimmer all of + + + align:start position:0% +send their taxes to a skimmer all of +these attacks were then prevented by the + + align:start position:0% +these attacks were then prevented by the + + + align:start position:0% +these attacks were then prevented by the +use of DNS SEC after each play we did a + + align:start position:0% +use of DNS SEC after each play we did a + + + align:start position:0% +use of DNS SEC after each play we did a +replay with deep structure analysis that + + align:start position:0% +replay with deep structure analysis that + + + align:start position:0% +replay with deep structure analysis that +made the analogy between the play and + + align:start position:0% +made the analogy between the play and + + + align:start position:0% +made the analogy between the play and +DNS explicit overall a pretty fun + + align:start position:0% +DNS explicit overall a pretty fun + + + align:start position:0% +DNS explicit overall a pretty fun +recitation and I was impressed with + + align:start position:0% +recitation and I was impressed with + + + align:start position:0% +recitation and I was impressed with +the creativity enthusiasm and acting + + align:start position:0% +the creativity enthusiasm and acting + + + align:start position:0% +the creativity enthusiasm and acting +talent the students displayed um so this + + align:start position:0% +talent the students displayed um so this + + + align:start position:0% +talent the students displayed um so this +was amazing + + align:start position:0% +was amazing + + + align:start position:0% +was amazing +this was like such this email thread + + align:start position:0% +this was like such this email thread + + + align:start position:0% +this was like such this email thread +it's just such a triumph for me I have + + align:start position:0% +it's just such a triumph for me I have + + + align:start position:0% +it's just such a triumph for me I have +it highlighted and saved in my email and + + align:start position:0% +it highlighted and saved in my email and + + + align:start position:0% +it highlighted and saved in my email and +this has continued on since last + + align:start position:0% +this has continued on since last + + + align:start position:0% +this has continued on since last +semester I get like one of these email + + align:start position:0% +semester I get like one of these email + + + align:start position:0% +semester I get like one of these email +threads a week now with my instructors + + align:start position:0% +threads a week now with my instructors + + + align:start position:0% +threads a week now with my instructors +telling me all of the cool things that + + align:start position:0% +telling me all of the cool things that + + + align:start position:0% +telling me all of the cool things that +they have done um so you know the last + + align:start position:0% +they have done um so you know the last + + + align:start position:0% +they have done um so you know the last +thing which I hope has come through in + + align:start position:0% +thing which I hope has come through in + + + align:start position:0% +thing which I hope has come through in +this talk it was a lot of work to get + + align:start position:0% +this talk it was a lot of work to get + + + align:start position:0% +this talk it was a lot of work to get +this to happen in o33 + + align:start position:0% +this to happen in o33 + + + align:start position:0% +this to happen in o33 +I cannot in good faith stand here and + + align:start position:0% +I cannot in good faith stand here and + + + align:start position:0% +I cannot in good faith stand here and +tell you active learning is a breeze you + + align:start position:0% +tell you active learning is a breeze you + + + align:start position:0% +tell you active learning is a breeze you +can just add it in five minutes of prep + + align:start position:0% +can just add it in five minutes of prep + + + align:start position:0% +can just add it in five minutes of prep +time before the class it's a lot of work + + align:start position:0% +time before the class it's a lot of work + + + align:start position:0% +time before the class it's a lot of work +by this class is so much fun now it's + + align:start position:0% +by this class is so much fun now it's + + + align:start position:0% +by this class is so much fun now it's +fun for me to run it's fun for + + align:start position:0% +fun for me to run it's fun for + + + align:start position:0% +fun for me to run it's fun for +instructors to teach I don't know how + + align:start position:0% +instructors to teach I don't know how + + + align:start position:0% +instructors to teach I don't know how +many people would tell you that they're + + align:start position:0% +many people would tell you that they're + + + align:start position:0% +many people would tell you that they're +400 person class is is fun to run all + + align:start position:0% +400 person class is is fun to run all + + + align:start position:0% +400 person class is is fun to run all +right but I have a great time and the + + align:start position:0% +right but I have a great time and the + + + align:start position:0% +right but I have a great time and the +amount of enjoyment that we get out of + + align:start position:0% +amount of enjoyment that we get out of + + + align:start position:0% +amount of enjoyment that we get out of +teaching or through through this ways + + align:start position:0% +teaching or through through this ways + + + align:start position:0% +teaching or through through this ways +really comes through for the students + + align:start position:0% +really comes through for the students + + + align:start position:0% +really comes through for the students +and I think that's another component of + + align:start position:0% +and I think that's another component of + + + align:start position:0% +and I think that's another component of +what has helped them engage more in this + + align:start position:0% +what has helped them engage more in this + + + align:start position:0% +what has helped them engage more in this +class so it has worked really well for + + align:start position:0% +class so it has worked really well for + + + align:start position:0% +class so it has worked really well for +us I hope that you got some practical + + align:start position:0% +us I hope that you got some practical + + + align:start position:0% +us I hope that you got some practical +things that you can try out in your own + + align:start position:0% +things that you can try out in your own + + + align:start position:0% +things that you can try out in your own +classes and I'm happy to take questions + + align:start position:0% +classes and I'm happy to take questions + + + align:start position:0% +classes and I'm happy to take questions +or to delegate questions off to Jesse + + align:start position:0% +or to delegate questions off to Jesse + + + align:start position:0% +or to delegate questions off to Jesse +and Karen + + align:start position:0% +and Karen + + + align:start position:0% +and Karen +[Applause] \ No newline at end of file diff --git a/r9_5dxtDTOk.txt b/r9_5dxtDTOk.txt new file mode 100644 index 0000000000000000000000000000000000000000..e459bd574f2afb8da017b51ad3aab3aa5a47272a --- /dev/null +++ b/r9_5dxtDTOk.txt @@ -0,0 +1,5819 @@ +align:start position:0% + +so you've already seen a little bit of + + align:start position:0% +so you've already seen a little bit of + + + align:start position:0% +so you've already seen a little bit of +the story of forward mode and reverse + + align:start position:0% +the story of forward mode and reverse + + + align:start position:0% +the story of forward mode and reverse +mode from Stephen last week one version + + align:start position:0% +mode from Stephen last week one version + + + align:start position:0% +mode from Stephen last week one version +of the story is that you're + + align:start position:0% +of the story is that you're + + + align:start position:0% +of the story is that you're +multiplying derivatives or or Jacobian + + align:start position:0% +multiplying derivatives or or Jacobian + + + align:start position:0% +multiplying derivatives or or Jacobian +matrices or or something like that and + + align:start position:0% +matrices or or something like that and + + + align:start position:0% +matrices or or something like that and +of course um you've heard Stephen say + + align:start position:0% +of course um you've heard Stephen say + + + align:start position:0% +of course um you've heard Stephen say +that Matrix multip lication is + + align:start position:0% +that Matrix multip lication is + + + align:start position:0% +that Matrix multip lication is +associative and so you can go left to + + align:start position:0% +associative and so you can go left to + + + align:start position:0% +associative and so you can go left to +right or right to left + + align:start position:0% +right or right to left + + + align:start position:0% +right or right to left +but but it matters what order you go in + + align:start position:0% +but but it matters what order you go in + + + align:start position:0% +but but it matters what order you go in +terms of the complexity of the + + align:start position:0% +terms of the complexity of the + + + align:start position:0% +terms of the complexity of the +computation that you know one order + + align:start position:0% +computation that you know one order + + + align:start position:0% +computation that you know one order +might be an N Cub computation and + + align:start position:0% +might be an N Cub computation and + + + align:start position:0% +might be an N Cub computation and +another order might be an N squ + + align:start position:0% +another order might be an N squ + + + align:start position:0% +another order might be an N squ +computation right and so you saw an + + align:start position:0% +computation right and so you saw an + + + align:start position:0% +computation right and so you saw an +example of that right and uh in some + + align:start position:0% +example of that right and uh in some + + + align:start position:0% +example of that right and uh in some +fundamental sense that describes the + + align:start position:0% +fundamental sense that describes the + + + align:start position:0% +fundamental sense that describes the +entire story of forward and reverse mode + + align:start position:0% +entire story of forward and reverse mode + + + align:start position:0% +entire story of forward and reverse mode +but in a way I feel like it hides more + + align:start position:0% +but in a way I feel like it hides more + + + align:start position:0% +but in a way I feel like it hides more +than it reveals right and + + align:start position:0% +than it reveals right and + + + align:start position:0% +than it reveals right and +there the story + + align:start position:0% +there the story + + + align:start position:0% +there the story +is in some sense the entire story can be + + align:start position:0% +is in some sense the entire story can be + + + align:start position:0% +is in some sense the entire story can be +reduced to that but that I feel like + + align:start position:0% +reduced to that but that I feel like + + + align:start position:0% +reduced to that but that I feel like +that's not enough to fully understand + + align:start position:0% +that's not enough to fully understand + + + align:start position:0% +that's not enough to fully understand +and so um I put together this uh example + + align:start position:0% +and so um I put together this uh example + + + align:start position:0% +and so um I put together this uh example +that I used in my class last semester + + align:start position:0% +that I used in my class last semester + + + align:start position:0% +that I used in my class last semester +and I just going to pull it all out I'm + + align:start position:0% +and I just going to pull it all out I'm + + + align:start position:0% +and I just going to pull it all out I'm +just going to grab a simple example from + + align:start position:0% +just going to grab a simple example from + + + align:start position:0% +just going to grab a simple example from +calculus and kind of show you what's + + align:start position:0% +calculus and kind of show you what's + + + align:start position:0% +calculus and kind of show you what's +really going on and so um I want to take + + align:start position:0% +really going on and so um I want to take + + + align:start position:0% +really going on and so um I want to take +this the simple example um there's + + align:start position:0% +this the simple example um there's + + + align:start position:0% +this the simple example um there's +nothing special about it I just randomly + + align:start position:0% +nothing special about it I just randomly + + + align:start position:0% +nothing special about it I just randomly +came up with it where I'm going to uh + + align:start position:0% +came up with it where I'm going to uh + + + align:start position:0% +came up with it where I'm going to uh +just input an X and A + + align:start position:0% +just input an X and A + + + align:start position:0% +just input an X and A +Y okay and I'm going to have three lines + + align:start position:0% +Y okay and I'm going to have three lines + + + align:start position:0% +Y okay and I'm going to have three lines +of code so to speak or three + + align:start position:0% +of code so to speak or three + + + align:start position:0% +of code so to speak or three +computations that are going to happen + + align:start position:0% +computations that are going to happen + + + align:start position:0% +computations that are going to happen +I'm going to take a to be + + align:start position:0% +I'm going to take a to be + + + align:start position:0% +I'm going to take a to be +sinx no reason whatsoever I'm going to + + align:start position:0% +sinx no reason whatsoever I'm going to + + + align:start position:0% +sinx no reason whatsoever I'm going to +take B to be a / y right and then um I + + align:start position:0% +take B to be a / y right and then um I + + + align:start position:0% +take B to be a / y right and then um I +like I like you know X and Y going in + + align:start position:0% +like I like you know X and Y going in + + + align:start position:0% +like I like you know X and Y going in +and Z being the the last letter being + + align:start position:0% +and Z being the the last letter being + + + align:start position:0% +and Z being the the last letter being +the final output so Z I'll have it be B + + align:start position:0% +the final output so Z I'll have it be B + + + align:start position:0% +the final output so Z I'll have it be B +plus X right you can see how that kind + + align:start position:0% +plus X right you can see how that kind + + + align:start position:0% +plus X right you can see how that kind +of looks like a computer program right + + align:start position:0% +of looks like a computer program right + + + align:start position:0% +of looks like a computer program right +uh as I mean it feels more like a + + align:start position:0% +uh as I mean it feels more like a + + + align:start position:0% +uh as I mean it feels more like a +computer program Than Mathematics where + + align:start position:0% +computer program Than Mathematics where + + + align:start position:0% +computer program Than Mathematics where +where uh you know you're writing + + align:start position:0% +where uh you know you're writing + + + align:start position:0% +where uh you know you're writing +inequality it looks like a sequence of + + align:start position:0% +inequality it looks like a sequence of + + + align:start position:0% +inequality it looks like a sequence of +steps where where uh at every step you + + align:start position:0% +steps where where uh at every step you + + + align:start position:0% +steps where where uh at every step you +at least you have the variables that + + align:start position:0% +at least you have the variables that + + + align:start position:0% +at least you have the variables that +came before right that what is a + + align:start position:0% +came before right that what is a + + + align:start position:0% +came before right that what is a +computer program in the end right it's + + align:start position:0% +computer program in the end right it's + + + align:start position:0% +computer program in the end right it's +it's a formula where on the right hand + + align:start position:0% +it's a formula where on the right hand + + + align:start position:0% +it's a formula where on the right hand +side you know the value of everything + + align:start position:0% +side you know the value of everything + + + align:start position:0% +side you know the value of everything +and so on the left hand side you can + + align:start position:0% +and so on the left hand side you can + + + align:start position:0% +and so on the left hand side you can +Define the thing right that that's + + align:start position:0% +Define the thing right that that's + + + align:start position:0% +Define the thing right that that's +that's what a you know a computer + + align:start position:0% +that's what a you know a computer + + + align:start position:0% +that's what a you know a computer +program basically is all right and one + + align:start position:0% +program basically is all right and one + + + align:start position:0% +program basically is all right and one +could have a problem like you know one + + align:start position:0% +could have a problem like you know one + + + align:start position:0% +could have a problem like you know one +could create this problem which is say + + align:start position:0% +could create this problem which is say + + + align:start position:0% +could create this problem which is say +you know find the derivatives right like + + align:start position:0% +you know find the derivatives right like + + + align:start position:0% +you know find the derivatives right like +you know + + align:start position:0% +you know + + + align:start position:0% +you know +find um DZ + + align:start position:0% +find um DZ + + + align:start position:0% +find um DZ +DX you know or find DZ + + align:start position:0% +DX you know or find DZ + + + align:start position:0% +DX you know or find DZ +Dy okay and you know this is pretty + + align:start position:0% +Dy okay and you know this is pretty + + + align:start position:0% +Dy okay and you know this is pretty +simple I mean you you all know how to do + + align:start position:0% +simple I mean you you all know how to do + + + align:start position:0% +simple I mean you you all know how to do +it I mean let's let's just um let's + + align:start position:0% +it I mean let's let's just um let's + + + align:start position:0% +it I mean let's let's just um let's +let's let's just start with the + + align:start position:0% +let's let's just start with the + + + align:start position:0% +let's let's just start with the +B right so um how might you do this well + + align:start position:0% +B right so um how might you do this well + + + align:start position:0% +B right so um how might you do this well +let's see so + + align:start position:0% +let's see so + + + align:start position:0% +let's see so +Z is B plus X let's just kind of figure + + align:start position:0% +Z is B plus X let's just kind of figure + + + align:start position:0% +Z is B plus X let's just kind of figure +out what's going on here B is a over y + + align:start position:0% +out what's going on here B is a over y + + + align:start position:0% +out what's going on here B is a over y +so this is a over y + x right going to + + align:start position:0% +so this is a over y + x right going to + + + align:start position:0% +so this is a over y + x right going to +get everything in terms of the x's and + + align:start position:0% +get everything in terms of the x's and + + + align:start position:0% +get everything in terms of the x's and +y's right a is sinx so we have sinx over + + align:start position:0% +y's right a is sinx so we have sinx over + + + align:start position:0% +y's right a is sinx so we have sinx over +y + x right and then now that we have + + align:start position:0% +y + x right and then now that we have + + + align:start position:0% +y + x right and then now that we have +everything in terms of X and y's we're + + align:start position:0% +everything in terms of X and y's we're + + + align:start position:0% +everything in terms of X and y's we're +all very good at this dzdx of course the + + align:start position:0% +all very good at this dzdx of course the + + + align:start position:0% +all very good at this dzdx of course the +actual answer is cosine X over + + align:start position:0% +actual answer is cosine X over + + + align:start position:0% +actual answer is cosine X over +y plus plus one right and then uh and + + align:start position:0% +y plus plus one right and then uh and + + + align:start position:0% +y plus plus one right and then uh and +then DZ + + align:start position:0% +then DZ + + + align:start position:0% +then DZ +Dy is what is it it's it's it's minus + + align:start position:0% +Dy is what is it it's it's it's minus + + + align:start position:0% +Dy is what is it it's it's it's minus +sinx over + + align:start position:0% +sinx over + + + align:start position:0% +sinx over +y^2 okay no controversy to this all + + align:start position:0% +y^2 okay no controversy to this all + + + align:start position:0% +y^2 okay no controversy to this all +simple stuff I mean if if my colleagues + + align:start position:0% +simple stuff I mean if if my colleagues + + + align:start position:0% +simple stuff I mean if if my colleagues +caught me doing this to you Advanced + + align:start position:0% +caught me doing this to you Advanced + + + align:start position:0% +caught me doing this to you Advanced +students they would make fun of me right + + align:start position:0% +students they would make fun of me right + + + align:start position:0% +students they would make fun of me right +this is just baby stuff right but let's + + align:start position:0% +this is just baby stuff right but let's + + + align:start position:0% +this is just baby stuff right but let's +kind of establish a little bit let's + + align:start position:0% +kind of establish a little bit let's + + + align:start position:0% +kind of establish a little bit let's +take a good look of what we just did + + align:start position:0% +take a good look of what we just did + + + align:start position:0% +take a good look of what we just did +let's let's kind of take a close look at + + align:start position:0% +let's let's kind of take a close look at + + + align:start position:0% +let's let's kind of take a close look at +this sort of thing and U let me + + align:start position:0% +this sort of thing and U let me + + + align:start position:0% +this sort of thing and U let me +introduce a computational gra let me + + align:start position:0% +introduce a computational gra let me + + + align:start position:0% +introduce a computational gra let me +kind of draw a picture of the + + align:start position:0% +kind of draw a picture of the + + + align:start position:0% +kind of draw a picture of the +computation we just + + align:start position:0% +computation we just + + + align:start position:0% +computation we just +did with with a computational graph so + + align:start position:0% +did with with a computational graph so + + + align:start position:0% +did with with a computational graph so +let's let's write that computational + + align:start position:0% +let's let's write that computational + + + align:start position:0% +let's let's write that computational +graph + + align:start position:0% + + + + align:start position:0% + +and by the way these notes are online I + + align:start position:0% +and by the way these notes are online I + + + align:start position:0% +and by the way these notes are online I +I'll put a pointer up in a terrible + + align:start position:0% +I'll put a pointer up in a terrible + + + align:start position:0% +I'll put a pointer up in a terrible +handwritten version one day I'll type + + align:start position:0% +handwritten version one day I'll type + + + align:start position:0% +handwritten version one day I'll type +this up better but um but we'll have a + + align:start position:0% +this up better but um but we'll have a + + + align:start position:0% +this up better but um but we'll have a +computational graph uh the graph will be + + align:start position:0% +computational graph uh the graph will be + + + align:start position:0% +computational graph uh the graph will be +a dag if you know what that word means + + align:start position:0% +a dag if you know what that word means + + + align:start position:0% +a dag if you know what that word means +directed ayylic graph which basically + + align:start position:0% +directed ayylic graph which basically + + + align:start position:0% +directed ayylic graph which basically +means that that there are arrows on all + + align:start position:0% +means that that there are arrows on all + + + align:start position:0% +means that that there are arrows on all +the edges and there are no Cycles right + + align:start position:0% +the edges and there are no Cycles right + + + align:start position:0% +the edges and there are no Cycles right +that that's what a computer program is + + align:start position:0% +that that's what a computer program is + + + align:start position:0% +that that's what a computer program is +it's it's it's how do you build a next + + align:start position:0% +it's it's it's how do you build a next + + + align:start position:0% +it's it's it's how do you build a next +variable from a previous variable and + + align:start position:0% +variable from a previous variable and + + + align:start position:0% +variable from a previous variable and +and and if you ever look leftward all + + align:start position:0% +and and if you ever look leftward all + + + align:start position:0% +and and if you ever look leftward all +the data is available to you right so + + align:start position:0% +the data is available to you right so + + + align:start position:0% +the data is available to you right so +that you don't get an error right and so + + align:start position:0% +that you don't get an error right and so + + + align:start position:0% +that you don't get an error right and so +I like to the people are not completely + + align:start position:0% +I like to the people are not completely + + + align:start position:0% +I like to the people are not completely +standard as to how they draw + + align:start position:0% +standard as to how they draw + + + align:start position:0% +standard as to how they draw +computational graphs it drives me crazy + + align:start position:0% +computational graphs it drives me crazy + + + align:start position:0% +computational graphs it drives me crazy +I'm going to take the convention that + + align:start position:0% +I'm going to take the convention that + + + align:start position:0% +I'm going to take the convention that +I'm going to put the variables at the + + align:start position:0% +I'm going to put the variables at the + + + align:start position:0% +I'm going to put the variables at the +variable names as nodes right so my + + align:start position:0% +variable names as nodes right so my + + + align:start position:0% +variable names as nodes right so my +input nodes are X and Y and let's see if + + align:start position:0% +input nodes are X and Y and let's see if + + + align:start position:0% +input nodes are X and Y and let's see if +I look at step one over there the first + + align:start position:0% +I look at step one over there the first + + + align:start position:0% +I look at step one over there the first +thing I'm going to calculate is a so + + align:start position:0% +thing I'm going to calculate is a so + + + align:start position:0% +thing I'm going to calculate is a so +that's going to be a Vertex or or a node + + align:start position:0% +that's going to be a Vertex or or a node + + + align:start position:0% +that's going to be a Vertex or or a node +and while I'm at it I'm going to + + align:start position:0% +and while I'm at it I'm going to + + + align:start position:0% +and while I'm at it I'm going to +draw um this Arrow right here okay and + + align:start position:0% +draw um this Arrow right here okay and + + + align:start position:0% +draw um this Arrow right here okay and +uh what I'm going to put on that arrow + + align:start position:0% +uh what I'm going to put on that arrow + + + align:start position:0% +uh what I'm going to put on that arrow +is + + align:start position:0% +is + + + align:start position:0% +is +not I'm not going to put the the the I + + align:start position:0% +not I'm not going to put the the the I + + + align:start position:0% +not I'm not going to put the the the I +mean you could draw the computation the + + align:start position:0% +mean you could draw the computation the + + + align:start position:0% +mean you could draw the computation the +sign but what I'm going to do is + + align:start position:0% +sign but what I'm going to do is + + + align:start position:0% +sign but what I'm going to do is +actually put the derivative on the Arrow + + align:start position:0% +actually put the derivative on the Arrow + + + align:start position:0% +actually put the derivative on the Arrow +okay and so I'm going on the Arrow I'm + + align:start position:0% +okay and so I'm going on the Arrow I'm + + + align:start position:0% +okay and so I'm going on the Arrow I'm +going to put the function cosine X right + + align:start position:0% +going to put the function cosine X right + + + align:start position:0% +going to put the function cosine X right +so the derivative of Oh I thought this + + align:start position:0% +so the derivative of Oh I thought this + + + align:start position:0% +so the derivative of Oh I thought this +thetive the way to read this is + + align:start position:0% +thetive the way to read this is + + + align:start position:0% +thetive the way to read this is +derivative of a with respect to X is + + align:start position:0% +derivative of a with respect to X is + + + align:start position:0% +derivative of a with respect to X is +what's on this Arrow okay so this is Da + + align:start position:0% +what's on this Arrow okay so this is Da + + + align:start position:0% +what's on this Arrow okay so this is Da +DX okay let's go another step B is a + + align:start position:0% +DX okay let's go another step B is a + + + align:start position:0% +DX okay let's go another step B is a +over y so I think you've got the idea + + align:start position:0% +over y so I think you've got the idea + + + align:start position:0% +over y so I think you've got the idea +now the B is going to be my node okay + + align:start position:0% +now the B is going to be my node okay + + + align:start position:0% +now the B is going to be my node okay +and uh I'm going to calculate dbd da + + align:start position:0% +and uh I'm going to calculate dbd da + + + align:start position:0% +and uh I'm going to calculate dbd da +what is what is + + align:start position:0% +what is what is + + + align:start position:0% +what is what is +dbda what should I put here as the + + align:start position:0% +dbda what should I put here as the + + + align:start position:0% +dbda what should I put here as the +function I want dbda I want the + + align:start position:0% +function I want dbda I want the + + + align:start position:0% +function I want dbda I want the +derivative I always want the the onestep + + align:start position:0% +derivative I always want the the onestep + + + align:start position:0% +derivative I always want the the onestep +derivative between this variable and + + align:start position:0% +derivative between this variable and + + + align:start position:0% +derivative between this variable and +this variable so I want the if I make if + + align:start position:0% +this variable so I want the if I make if + + + align:start position:0% +this variable so I want the if I make if +I vary a a little bit right what do I + + align:start position:0% +I vary a a little bit right what do I + + + align:start position:0% +I vary a a little bit right what do I +multiply by what's + + align:start position:0% +multiply by what's + + + align:start position:0% +multiply by what's +dbda one over y good right let's just I + + align:start position:0% +dbda one over y good right let's just I + + + align:start position:0% +dbda one over y good right let's just I +started with a over Y and I take to X + + align:start position:0% +started with a over Y and I take to X + + + align:start position:0% +started with a over Y and I take to X +that's one over y good all right and but + + align:start position:0% +that's one over y good all right and but + + + align:start position:0% +that's one over y good all right and but +we also have a DB B Dy so let's put an + + align:start position:0% +we also have a DB B Dy so let's put an + + + align:start position:0% +we also have a DB B Dy so let's put an +arrow like that and what's DB Dy again + + align:start position:0% +arrow like that and what's DB Dy again + + + align:start position:0% +arrow like that and what's DB Dy again +simple questions but better keep you + + align:start position:0% +simple questions but better keep you + + + align:start position:0% +simple questions but better keep you +guys awake keep me awake what's dbd + + align:start position:0% + + + + align:start position:0% + +y right negative a over y^2 good and + + align:start position:0% +y right negative a over y^2 good and + + + align:start position:0% +y right negative a over y^2 good and +finally we have a + + align:start position:0% +finally we have a + + + align:start position:0% +finally we have a +z and Z depends on B and it also depends + + align:start position:0% +z and Z depends on B and it also depends + + + align:start position:0% +z and Z depends on B and it also depends +on + + align:start position:0% +on + + + align:start position:0% +on +X right so we have a dependence that + + align:start position:0% +X right so we have a dependence that + + + align:start position:0% +X right so we have a dependence that +goes back to the beginning with Z right + + align:start position:0% +goes back to the beginning with Z right + + + align:start position:0% +goes back to the beginning with Z right +and so let's see what's what are DZ DB + + align:start position:0% +and so let's see what's what are DZ DB + + + align:start position:0% +and so let's see what's what are DZ DB +and dzdx they're kind of the same answer + + align:start position:0% +and dzdx they're kind of the same answer + + + align:start position:0% +and dzdx they're kind of the same answer +they're both what are the what what + + align:start position:0% +they're both what are the what what + + + align:start position:0% +they're both what are the what what +what's dcdb and what's DC + + align:start position:0% + + + + align:start position:0% + +DX come on first grade question really + + align:start position:0% +DX come on first grade question really + + + align:start position:0% +DX come on first grade question really +one right they're both One DB is one DX + + align:start position:0% +one right they're both One DB is one DX + + + align:start position:0% +one right they're both One DB is one DX +is one right because D is just B plus X + + align:start position:0% +is one right because D is just B plus X + + + align:start position:0% +is one right because D is just B plus X +okay so derivatives on the edges you you + + align:start position:0% +okay so derivatives on the edges you you + + + align:start position:0% +okay so derivatives on the edges you you +see you get the point that derivative is + + align:start position:0% +see you get the point that derivative is + + + align:start position:0% +see you get the point that derivative is +labeled on the Ed derivatives on edges + + align:start position:0% +labeled on the Ed derivatives on edges + + + align:start position:0% +labeled on the Ed derivatives on edges +just to write that down for you um and + + align:start position:0% +just to write that down for you um and + + + align:start position:0% +just to write that down for you um and +you know and it's it's just I I like to + + align:start position:0% +you know and it's it's just I I like to + + + align:start position:0% +you know and it's it's just I I like to +think of this as a one step + + align:start position:0% +think of this as a one step + + + align:start position:0% +think of this as a one step +derivative right so it's like it's it's + + align:start position:0% +derivative right so it's like it's it's + + + align:start position:0% +derivative right so it's like it's it's +a derivative of one line of code if You' + + align:start position:0% +a derivative of one line of code if You' + + + align:start position:0% +a derivative of one line of code if You' +like right it's I'm not putting in the + + align:start position:0% +like right it's I'm not putting in the + + + align:start position:0% +like right it's I'm not putting in the +I'm not putting in the full you know the + + align:start position:0% +I'm not putting in the full you know the + + + align:start position:0% +I'm not putting in the full you know the +full long range derivative I'm just + + align:start position:0% +full long range derivative I'm just + + + align:start position:0% +full long range derivative I'm just +putting in the one-step derivative right + + align:start position:0% +putting in the one-step derivative right + + + align:start position:0% +putting in the one-step derivative right +so uh right in other words + + align:start position:0% +so uh right in other words + + + align:start position:0% +so uh right in other words +I'm not putting in this thing which is + + align:start position:0% +I'm not putting in this thing which is + + + align:start position:0% +I'm not putting in this thing which is +the the full the full derivative it's + + align:start position:0% +the the full the full derivative it's + + + align:start position:0% +the the full the full derivative it's +just the one step that I'm putting in + + align:start position:0% +just the one step that I'm putting in + + + align:start position:0% +just the one step that I'm putting in +okay and I want to sort of kind of put + + align:start position:0% +okay and I want to sort of kind of put + + + align:start position:0% +okay and I want to sort of kind of put +on the graph what we just did uh to well + + align:start position:0% +on the graph what we just did uh to well + + + align:start position:0% +on the graph what we just did uh to well +let's get the answer now okay so I claim + + align:start position:0% +let's get the answer now okay so I claim + + + align:start position:0% +let's get the answer now okay so I claim +that uh one way to get the actual answer + + align:start position:0% +that uh one way to get the actual answer + + + align:start position:0% +that uh one way to get the actual answer +is to think of it graphically that you + + align:start position:0% +is to think of it graphically that you + + + align:start position:0% +is to think of it graphically that you +could + + align:start position:0% +could + + + align:start position:0% +could +start over here at X and we want to head + + align:start position:0% +start over here at X and we want to head + + + align:start position:0% +start over here at X and we want to head +to Z okay and we're going to look at all + + align:start position:0% +to Z okay and we're going to look at all + + + align:start position:0% +to Z okay and we're going to look at all +the paths that will take us from X to Z + + align:start position:0% +the paths that will take us from X to Z + + + align:start position:0% +the paths that will take us from X to Z +right there's one path that goes like + + align:start position:0% +right there's one path that goes like + + + align:start position:0% +right there's one path that goes like +this okay and then there's another path + + align:start position:0% +this okay and then there's another path + + + align:start position:0% +this okay and then there's another path +that goes like this right so there's two + + align:start position:0% +that goes like this right so there's two + + + align:start position:0% +that goes like this right so there's two +paths it'll take us from X to Z and uh + + align:start position:0% +paths it'll take us from X to Z and uh + + + align:start position:0% +paths it'll take us from X to Z and uh +and and um and what I'd like to do is is + + align:start position:0% +and and um and what I'd like to do is is + + + align:start position:0% +and and um and what I'd like to do is is +basically walk along the path and then + + align:start position:0% +basically walk along the path and then + + + align:start position:0% +basically walk along the path and then +write down the derivative I see as I + + align:start position:0% +write down the derivative I see as I + + + align:start position:0% +write down the derivative I see as I +though okay and I'm going to write it + + align:start position:0% +though okay and I'm going to write it + + + align:start position:0% +though okay and I'm going to write it +I'm going to write it right to left so + + align:start position:0% +I'm going to write it right to left so + + + align:start position:0% +I'm going to write it right to left so +let me let me start walking from X to a + + align:start position:0% +let me let me start walking from X to a + + + align:start position:0% +let me let me start walking from X to a +along this path okay when I go from X to + + align:start position:0% +along this path okay when I go from X to + + + align:start position:0% +along this path okay when I go from X to +a I pick up a cosine + + align:start position:0% +a I pick up a cosine + + + align:start position:0% +a I pick up a cosine +X all right so this is step one right I + + align:start position:0% +X all right so this is step one right I + + + align:start position:0% +X all right so this is step one right I +pick up a cosine X okay then I have to + + align:start position:0% +pick up a cosine X okay then I have to + + + align:start position:0% +pick up a cosine X okay then I have to +step over from A to B so I pick up a one + + align:start position:0% +step over from A to B so I pick up a one + + + align:start position:0% +step over from A to B so I pick up a one +over + + align:start position:0% +over + + + align:start position:0% +over +y right so that's my step + + align:start position:0% +y right so that's my step + + + align:start position:0% +y right so that's my step +two okay and then finally when I go from + + align:start position:0% +two okay and then finally when I go from + + + align:start position:0% +two okay and then finally when I go from +B to Z I have a factor of one one so + + align:start position:0% +B to Z I have a factor of one one so + + + align:start position:0% +B to Z I have a factor of one one so +that's my step three okay uh I have + + align:start position:0% +that's my step three okay uh I have + + + align:start position:0% +that's my step three okay uh I have +another path I I have to cross I have to + + align:start position:0% +another path I I have to cross I have to + + + align:start position:0% +another path I I have to cross I have to +take all possible paths so my next PATH + + align:start position:0% +take all possible paths so my next PATH + + + align:start position:0% +take all possible paths so my next PATH +is the one that goes from X to Z right + + align:start position:0% +is the one that goes from X to Z right + + + align:start position:0% +is the one that goes from X to Z right +and so um I add the one over here right + + align:start position:0% +and so um I add the one over here right + + + align:start position:0% +and so um I add the one over here right +there's only one step to that okay and + + align:start position:0% +there's only one step to that okay and + + + align:start position:0% +there's only one step to that okay and +so and so that's the uh that that that's + + align:start position:0% +so and so that's the uh that that that's + + + align:start position:0% +so and so that's the uh that that that's +the answer actually 1/ Y X + 1 is the + + align:start position:0% +the answer actually 1/ Y X + 1 is the + + + align:start position:0% +the answer actually 1/ Y X + 1 is the +answer for for respect to X right so you + + align:start position:0% +answer for for respect to X right so you + + + align:start position:0% +answer for for respect to X right so you +can view it in that way as all possible + + align:start position:0% +can view it in that way as all possible + + + align:start position:0% +can view it in that way as all possible +paths from input to output and then just + + align:start position:0% +paths from input to output and then just + + + align:start position:0% +paths from input to output and then just +multiply as you go and of course with + + align:start position:0% +multiply as you go and of course with + + + align:start position:0% +multiply as you go and of course with +scalers I could have multiplied in any + + align:start position:0% +scalers I could have multiplied in any + + + align:start position:0% +scalers I could have multiplied in any +order but you can imagine why I hope you + + align:start position:0% +order but you can imagine why I hope you + + + align:start position:0% +order but you can imagine why I hope you +could understand why I went from right + + align:start position:0% +could understand why I went from right + + + align:start position:0% +could understand why I went from right +to left I didn't really need it for this + + align:start position:0% +to left I didn't really need it for this + + + align:start position:0% +to left I didn't really need it for this +problem but I wanted to set up a good + + align:start position:0% +problem but I wanted to set up a good + + + align:start position:0% +problem but I wanted to set up a good +plan for when these are not scalers but + + align:start position:0% +plan for when these are not scalers but + + + align:start position:0% +plan for when these are not scalers but +these are vectors or Matrix value + + align:start position:0% +these are vectors or Matrix value + + + align:start position:0% +these are vectors or Matrix value +functions right and then then in the + + align:start position:0% +functions right and then then in the + + + align:start position:0% +functions right and then then in the +order matters and so the Matrix multiply + + align:start position:0% +order matters and so the Matrix multiply + + + align:start position:0% +order matters and so the Matrix multiply +has to go from right to left Okay so uh + + align:start position:0% +has to go from right to left Okay so uh + + + align:start position:0% +has to go from right to left Okay so uh +in this case it wouldn't have mattered + + align:start position:0% +in this case it wouldn't have mattered + + + align:start position:0% +in this case it wouldn't have mattered +so so this is the correct answer for DZ + + align:start position:0% + + + + align:start position:0% + +DX right and DZ Dy + + align:start position:0% +DX right and DZ Dy + + + align:start position:0% +DX right and DZ Dy +similarly is you know we we we have at + + align:start position:0% +similarly is you know we we we have at + + + align:start position:0% +similarly is you know we we we have at +the first step we have minus a over y^2 + + align:start position:0% +the first step we have minus a over y^2 + + + align:start position:0% +the first step we have minus a over y^2 +that's step one step two is to multiply + + align:start position:0% +that's step one step two is to multiply + + + align:start position:0% +that's step one step two is to multiply +that root by one which doesn't do + + align:start position:0% +that root by one which doesn't do + + + align:start position:0% +that root by one which doesn't do +anything right and you see the answer is + + align:start position:0% +anything right and you see the answer is + + + align:start position:0% +anything right and you see the answer is +uh wait what what is the answer the + + align:start position:0% +uh wait what what is the answer the + + + align:start position:0% +uh wait what what is the answer the +answer is yeah minus yeah minus minus a + + align:start position:0% +answer is yeah minus yeah minus minus a + + + align:start position:0% +answer is yeah minus yeah minus minus a +over y^2 which you could substitute the + + align:start position:0% +over y^2 which you could substitute the + + + align:start position:0% +over y^2 which you could substitute the +computer wouldn't care right if the + + align:start position:0% +computer wouldn't care right if the + + + align:start position:0% +computer wouldn't care right if the +computer the computer has the value of a + + align:start position:0% +computer the computer has the value of a + + + align:start position:0% +computer the computer has the value of a +uh and a is is sinx but you might like + + align:start position:0% +uh and a is is sinx but you might like + + + align:start position:0% +uh and a is is sinx but you might like +to see it in that + + align:start position:0% +to see it in that + + + align:start position:0% +to see it in that +format okay so this is forward mode + + align:start position:0% +format okay so this is forward mode + + + align:start position:0% +format okay so this is forward mode +automatic differentiation this is + + align:start position:0% +automatic differentiation this is + + + align:start position:0% +automatic differentiation this is +basically what was going on in the + + align:start position:0% +basically what was going on in the + + + align:start position:0% +basically what was going on in the +algorithm that I just showed you with + + align:start position:0% +algorithm that I just showed you with + + + align:start position:0% +algorithm that I just showed you with +the baboni alith this is this is kind of + + align:start position:0% +the baboni alith this is this is kind of + + + align:start position:0% +the baboni alith this is this is kind of +maybe the better way to look at it + + align:start position:0% +maybe the better way to look at it + + + align:start position:0% +maybe the better way to look at it +where uh what's happening is as you + + align:start position:0% +where uh what's happening is as you + + + align:start position:0% +where uh what's happening is as you +Traverse through this computer program + + align:start position:0% +Traverse through this computer program + + + align:start position:0% +Traverse through this computer program +in in that order you can actually + + align:start position:0% +in in that order you can actually + + + align:start position:0% +in in that order you can actually +calculate this this each of these things + + align:start position:0% +calculate this this each of these things + + + align:start position:0% +calculate this this each of these things +in order as well and thereby you can + + align:start position:0% +in order as well and thereby you can + + + align:start position:0% +in order as well and thereby you can +actually accumulate the derivatives as + + align:start position:0% +actually accumulate the derivatives as + + + align:start position:0% +actually accumulate the derivatives as +you go right so this is the the forward + + align:start position:0% +you go right so this is the the forward + + + align:start position:0% +you go right so this is the the forward +mode view of of differentiation and like + + align:start position:0% +mode view of of differentiation and like + + + align:start position:0% +mode view of of differentiation and like +I said there there's nothing magic about + + align:start position:0% +I said there there's nothing magic about + + + align:start position:0% +I said there there's nothing magic about +everything being a scaler here every one + + align:start position:0% +everything being a scaler here every one + + + align:start position:0% +everything being a scaler here every one +of these could be a function like you've + + align:start position:0% +of these could be a function like you've + + + align:start position:0% +of these could be a function like you've +seen in this class for example it could + + align:start position:0% +seen in this class for example it could + + + align:start position:0% +seen in this class for example it could +have been that that X was a matrix and a + + align:start position:0% +have been that that X was a matrix and a + + + align:start position:0% +have been that that X was a matrix and a +was the square function or the inverse + + align:start position:0% +was the square function or the inverse + + + align:start position:0% +was the square function or the inverse +function of a matrix right uh this could + + align:start position:0% +function of a matrix right uh this could + + + align:start position:0% +function of a matrix right uh this could +have been a determinant right and you + + align:start position:0% +have been a determinant right and you + + + align:start position:0% +have been a determinant right and you +know and uh you know or this could have + + align:start position:0% +know and uh you know or this could have + + + align:start position:0% +know and uh you know or this could have +been a matrix and this could have been a + + align:start position:0% +been a matrix and this could have been a + + + align:start position:0% +been a matrix and this could have been a +determinant and then in this case you've + + align:start position:0% +determinant and then in this case you've + + + align:start position:0% +determinant and then in this case you've +got the the gradient of of the of the + + align:start position:0% +got the the gradient of of the of the + + + align:start position:0% +got the the gradient of of the of the +determinant with respect to the Matrix + + align:start position:0% +determinant with respect to the Matrix + + + align:start position:0% +determinant with respect to the Matrix +the very thing I showed you earlier with + + align:start position:0% +the very thing I showed you earlier with + + + align:start position:0% +the very thing I showed you earlier with +with with the Agate right so um the only + + align:start position:0% +with with the Agate right so um the only + + + align:start position:0% +with with the Agate right so um the only +thing that's required is the + + align:start position:0% +thing that's required is the + + + align:start position:0% +thing that's required is the +associativity right and uh and the and + + align:start position:0% +associativity right and uh and the and + + + align:start position:0% +associativity right and uh and the and +and the only thing that matters is that + + align:start position:0% +and the only thing that matters is that + + + align:start position:0% +and the only thing that matters is that +uh if you ever bring things together you + + align:start position:0% +uh if you ever bring things together you + + + align:start position:0% +uh if you ever bring things together you +have to add the answers right so you can + + align:start position:0% +have to add the answers right so you can + + + align:start position:0% +have to add the answers right so you can +imagine a computer program where there's + + align:start position:0% +imagine a computer program where there's + + + align:start position:0% +imagine a computer program where there's +all sorts of arrows coming from left to + + align:start position:0% +all sorts of arrows coming from left to + + + align:start position:0% +all sorts of arrows coming from left to +right and as long as more than one Arrow + + align:start position:0% +right and as long as more than one Arrow + + + align:start position:0% +right and as long as more than one Arrow +comes in you just add the answers + + align:start position:0% +comes in you just add the answers + + + align:start position:0% +comes in you just add the answers +because that's how derivatives work okay + + align:start position:0% +because that's how derivatives work okay + + + align:start position:0% +because that's how derivatives work okay +so that's forward mode of + + align:start position:0% +so that's forward mode of + + + align:start position:0% +so that's forward mode of +differentiation okay um there is a + + align:start position:0% +differentiation okay um there is a + + + align:start position:0% +differentiation okay um there is a +um there is a backward + + align:start position:0% +um there is a backward + + + align:start position:0% +um there is a backward +mode uh let's see so so where you follow + + align:start position:0% +mode uh let's see so so where you follow + + + align:start position:0% +mode uh let's see so so where you follow +the paths backwards okay and so um when + + align:start position:0% +the paths backwards okay and so um when + + + align:start position:0% +the paths backwards okay and so um when +you follow it + + align:start position:0% + + + + align:start position:0% + +backwards so let me just see oh now + + align:start position:0% +backwards so let me just see oh now + + + align:start position:0% +backwards so let me just see oh now +here's + + align:start position:0% +here's + + + align:start position:0% +here's +where okay I'm not going to transpose it + + align:start position:0% +where okay I'm not going to transpose it + + + align:start position:0% +where okay I'm not going to transpose it +let me let me here's where I'm actually + + align:start position:0% +let me let me here's where I'm actually + + + align:start position:0% +let me let me here's where I'm actually +using I'm gonna use the fact that it's + + align:start position:0% +using I'm gonna use the fact that it's + + + align:start position:0% +using I'm gonna use the fact that it's +scalers now so this this is this whole + + align:start position:0% +scalers now so this this is this whole + + + align:start position:0% +scalers now so this this is this whole +calculation I just showed you was + + align:start position:0% +calculation I just showed you was + + + align:start position:0% +calculation I just showed you was +forward mode right so this and this is + + align:start position:0% +forward mode right so this and this is + + + align:start position:0% +forward mode right so this and this is +forward mode I'm going to do reverse + + align:start position:0% +forward mode I'm going to do reverse + + + align:start position:0% +forward mode I'm going to do reverse +mode for + + align:start position:0% +mode for + + + align:start position:0% +mode for +scalers when we get to matrices have we + + align:start position:0% +scalers when we get to matrices have we + + + align:start position:0% +scalers when we get to matrices have we +might have to transpose things but let + + align:start position:0% +might have to transpose things but let + + + align:start position:0% +might have to transpose things but let +let me just show you reverse mode for + + align:start position:0% +let me just show you reverse mode for + + + align:start position:0% +let me just show you reverse mode for +scalers just to get that + + align:start position:0% + + + + align:start position:0% + +correct okay so reverse mode for scalers + + align:start position:0% +correct okay so reverse mode for scalers + + + align:start position:0% +correct okay so reverse mode for scalers +says okay uh let's + + align:start position:0% +says okay uh let's + + + align:start position:0% +says okay uh let's +start let's start not on the left end + + align:start position:0% +start let's start not on the left end + + + align:start position:0% +start let's start not on the left end +but let's start on the Right End okay so + + align:start position:0% +but let's start on the Right End okay so + + + align:start position:0% +but let's start on the Right End okay so +and you might remember a week ago I said + + align:start position:0% +and you might remember a week ago I said + + + align:start position:0% +and you might remember a week ago I said +when you do like if you had s of of S of + + align:start position:0% +when you do like if you had s of of S of + + + align:start position:0% +when you do like if you had s of of S of +X squar how many of you you know I asked + + align:start position:0% +X squar how many of you you know I asked + + + align:start position:0% +X squar how many of you you know I asked +the question how many of you would the + + align:start position:0% +the question how many of you would the + + + align:start position:0% +the question how many of you would the +derivative would be cosine of x^2 * 2X + + align:start position:0% +derivative would be cosine of x^2 * 2X + + + align:start position:0% +derivative would be cosine of x^2 * 2X +and how many would have said 2x * the + + align:start position:0% +and how many would have said 2x * the + + + align:start position:0% +and how many would have said 2x * the +cosine of X2 right it's a matter of + + align:start position:0% +cosine of X2 right it's a matter of + + + align:start position:0% +cosine of X2 right it's a matter of +going inside out or outside in and you + + align:start position:0% +going inside out or outside in and you + + + align:start position:0% +going inside out or outside in and you +can go either way so uh for the reverse + + align:start position:0% +can go either way so uh for the reverse + + + align:start position:0% +can go either way so uh for the reverse +mode what we're going to do do is we're + + align:start position:0% +mode what we're going to do do is we're + + + align:start position:0% +mode what we're going to do do is we're +going to uh follow our way from the Z to + + align:start position:0% +going to uh follow our way from the Z to + + + align:start position:0% +going to uh follow our way from the Z to +the X right and of course there's two + + align:start position:0% +the X right and of course there's two + + + align:start position:0% +the X right and of course there's two +ways to do that and if you do that um + + align:start position:0% +ways to do that and if you do that um + + + align:start position:0% +ways to do that and if you do that um +I'm going to again write it from from + + align:start position:0% +I'm going to again write it from from + + + align:start position:0% +I'm going to again write it from from +right to left I'm going to start I'll + + align:start position:0% +right to left I'm going to start I'll + + + align:start position:0% +right to left I'm going to start I'll +take that first that that horizontal + + align:start position:0% +take that first that that horizontal + + + align:start position:0% +take that first that that horizontal +path right and I'm just going to go I'm + + align:start position:0% +path right and I'm just going to go I'm + + + align:start position:0% +path right and I'm just going to go I'm +going to write down the one the f as the + + align:start position:0% +going to write down the one the f as the + + + align:start position:0% +going to write down the one the f as the +first thing I do right and then the + + align:start position:0% +first thing I do right and then the + + + align:start position:0% +first thing I do right and then the +second thing I'm going to do is write + + align:start position:0% +second thing I'm going to do is write + + + align:start position:0% +second thing I'm going to do is write +down the one over Y and then the third + + align:start position:0% +down the one over Y and then the third + + + align:start position:0% +down the one over Y and then the third +thing I'm going to do is write down the + + align:start position:0% +thing I'm going to do is write down the + + + align:start position:0% +thing I'm going to do is write down the +cosine X right but every time I when I + + align:start position:0% +cosine X right but every time I when I + + + align:start position:0% +cosine X right but every time I when I +go right to left when the path splits + + align:start position:0% +go right to left when the path splits + + + align:start position:0% +go right to left when the path splits +like that I also have to add it so I'm + + align:start position:0% +like that I also have to add it so I'm + + + align:start position:0% +like that I also have to add it so I'm +also going to have to add a one right + + align:start position:0% +also going to have to add a one right + + + align:start position:0% +also going to have to add a one right +and uh as as + + align:start position:0% +and uh as as + + + align:start position:0% +and uh as as +well and I'll do that on the on the um + + align:start position:0% +well and I'll do that on the on the um + + + align:start position:0% +well and I'll do that on the on the um +you know I don't know when you're going + + align:start position:0% +you know I don't know when you're going + + + align:start position:0% +you know I don't know when you're going +to do that but I'll just say you can do + + align:start position:0% +to do that but I'll just say you can do + + + align:start position:0% +to do that but I'll just say you can do +that on step one as well all right and + + align:start position:0% +that on step one as well all right and + + + align:start position:0% +that on step one as well all right and +so + + align:start position:0% +so + + + align:start position:0% +so +that's right and here again you're going + + align:start position:0% +that's right and here again you're going + + + align:start position:0% +that's right and here again you're going +to do the one on the first step and the + + align:start position:0% +to do the one on the first step and the + + + align:start position:0% +to do the one on the first step and the +minus a over y^2 we're now going to do + + align:start position:0% +minus a over y^2 we're now going to do + + + align:start position:0% +minus a over y^2 we're now going to do +in the Second Step you see and either + + align:start position:0% +in the Second Step you see and either + + + align:start position:0% +in the Second Step you see and either +way we're going to get the solution to + + align:start position:0% +way we're going to get the solution to + + + align:start position:0% +way we're going to get the solution to +dzdx and + + align:start position:0% + + + + align:start position:0% + +dz1 okay and in a sense every + + align:start position:0% +dz1 okay and in a sense every + + + align:start position:0% +dz1 okay and in a sense every +calculation of the world can be looked + + align:start position:0% +calculation of the world can be looked + + + align:start position:0% +calculation of the world can be looked +at as a dad and it could be looked at as + + align:start position:0% +at as a dad and it could be looked at as + + + align:start position:0% +at as a dad and it could be looked at as +operations and you could think of it as + + align:start position:0% +operations and you could think of it as + + + align:start position:0% +operations and you could think of it as +basically following paths like this okay + + align:start position:0% + + + + align:start position:0% + +um so to kind of emphasize this and I in + + align:start position:0% +um so to kind of emphasize this and I in + + + align:start position:0% +um so to kind of emphasize this and I in +a way you can embed all this in + + align:start position:0% +a way you can embed all this in + + + align:start position:0% +a way you can embed all this in +matrices uh but I feel like it it it it + + align:start position:0% +matrices uh but I feel like it it it it + + + align:start position:0% +matrices uh but I feel like it it it it +hides you don't without seeing the graph + + align:start position:0% +hides you don't without seeing the graph + + + align:start position:0% +hides you don't without seeing the graph +structure you don't really get the full + + align:start position:0% +structure you don't really get the full + + + align:start position:0% +structure you don't really get the full +feel I think of what oh yes I was + + align:start position:0% +feel I think of what oh yes I was + + + align:start position:0% +feel I think of what oh yes I was +wondering I don't know + + align:start position:0% +wondering I don't know + + + align:start position:0% +wondering I don't know +recording oh my + + align:start position:0% +recording oh my + + + align:start position:0% +recording oh my +gosh I don't know if yeah good point I + + align:start position:0% +gosh I don't know if yeah good point I + + + align:start position:0% +gosh I don't know if yeah good point I +forgot to put on the + + align:start position:0% +forgot to put on the + + + align:start position:0% +forgot to put on the +mic thank you for catching that I don't + + align:start position:0% +mic thank you for catching that I don't + + + align:start position:0% +mic thank you for catching that I don't +know how well it'll work probably + + align:start position:0% +know how well it'll work probably + + + align:start position:0% +know how well it'll work probably +badly were you able to hear me Stephen + + align:start position:0% +badly were you able to hear me Stephen + + + align:start position:0% +badly were you able to hear me Stephen +maybe the zoom recording is not so bad I + + align:start position:0% +maybe the zoom recording is not so bad I + + + align:start position:0% +maybe the zoom recording is not so bad I +can hear you so we actually have a back + + align:start position:0% +can hear you so we actually have a back + + + align:start position:0% +can hear you so we actually have a back +up if we know how to splice it in but + + align:start position:0% +up if we know how to splice it in but + + + align:start position:0% +up if we know how to splice it in but +I'm going to put it on now thank you for + + align:start position:0% +I'm going to put it on now thank you for + + + align:start position:0% +I'm going to put it on now thank you for +catching + + align:start position:0% +catching + + + align:start position:0% +catching +that any questions about uh + + align:start position:0% +that any questions about uh + + + align:start position:0% +that any questions about uh +non-technical stuff but forward and + + align:start position:0% +non-technical stuff but forward and + + + align:start position:0% +non-technical stuff but forward and +reverse not not the audio visual + + align:start position:0% +reverse not not the audio visual + + + align:start position:0% +reverse not not the audio visual +stuff + + align:start position:0% + + + + align:start position:0% + +so um + + align:start position:0% + + + + align:start position:0% + +so okay so let's delve in a little bit + + align:start position:0% +so okay so let's delve in a little bit + + + align:start position:0% +so okay so let's delve in a little bit +about like how does one think about this + + align:start position:0% +about like how does one think about this + + + align:start position:0% +about like how does one think about this +so there's a graph Theory way and an + + align:start position:0% +so there's a graph Theory way and an + + + align:start position:0% +so there's a graph Theory way and an +implementation way of thinking about + + align:start position:0% +implementation way of thinking about + + + align:start position:0% +implementation way of thinking about +this a little bit so the graph Theory + + align:start position:0% +this a little bit so the graph Theory + + + align:start position:0% +this a little bit so the graph Theory +way of thinking about this is to U think + + align:start position:0% +way of thinking about this is to U think + + + align:start position:0% +way of thinking about this is to U think +about the fact that what we want to do + + align:start position:0% +about the fact that what we want to do + + + align:start position:0% +about the fact that what we want to do +is really calculate the sum of all the + + align:start position:0% +is really calculate the sum of all the + + + align:start position:0% +is really calculate the sum of all the +path products from inputs to outputs + + align:start position:0% +path products from inputs to outputs + + + align:start position:0% +path products from inputs to outputs +right right so I just gave you a term + + align:start position:0% +right right so I just gave you a term + + + align:start position:0% +right right so I just gave you a term +right so I'm going to define a a path + + align:start position:0% + + + + align:start position:0% + +product I'll I'll Define it Loosely I I + + align:start position:0% +product I'll I'll Define it Loosely I I + + + align:start position:0% +product I'll I'll Define it Loosely I I +hope this will be good enough the path + + align:start position:0% +hope this will be good enough the path + + + align:start position:0% +hope this will be good enough the path +product will be the sort of the the + + align:start position:0% +product will be the sort of the the + + + align:start position:0% +product will be the sort of the the +product of the edge + + align:start position:0% + + + + align:start position:0% + +weights okay it has the product has to + + align:start position:0% +weights okay it has the product has to + + + align:start position:0% +weights okay it has the product has to +be in the right order if it doesn't you + + align:start position:0% +be in the right order if it doesn't you + + + align:start position:0% +be in the right order if it doesn't you +know if it's associative but not + + align:start position:0% +know if it's associative but not + + + align:start position:0% +know if it's associative but not +communative but product of edge weights + + align:start position:0% +communative but product of edge weights + + + align:start position:0% +communative but product of edge weights +as you Traverse a + + align:start position:0% + + + + align:start position:0% + +path okay so uh the the the path + + align:start position:0% +path okay so uh the the the path + + + align:start position:0% +path okay so uh the the the path +products are so cosine X over Y is One + + align:start position:0% +products are so cosine X over Y is One + + + align:start position:0% +products are so cosine X over Y is One +path product with that length three path + + align:start position:0% +path product with that length three path + + + align:start position:0% +path product with that length three path +uh one is just that one length One path + + align:start position:0% +uh one is just that one length One path + + + align:start position:0% +uh one is just that one length One path +right and so those are the two path + + align:start position:0% +right and so those are the two path + + + align:start position:0% +right and so those are the two path +products right and then what we're + + align:start position:0% +products right and then what we're + + + align:start position:0% +products right and then what we're +interested in is one way or another + + align:start position:0% +interested in is one way or another + + + align:start position:0% +interested in is one way or another +calculating the the + + align:start position:0% +calculating the the + + + align:start position:0% +calculating the the +sum of path products + + align:start position:0% +sum of path products + + + align:start position:0% +sum of path products +from inputs to + + align:start position:0% + + + + align:start position:0% + +outputs but that's kind of the real goal + + align:start position:0% +outputs but that's kind of the real goal + + + align:start position:0% +outputs but that's kind of the real goal +of doing that and it doesn't really + + align:start position:0% +of doing that and it doesn't really + + + align:start position:0% +of doing that and it doesn't really +matter whether you go from the end of + + align:start position:0% +matter whether you go from the end of + + + align:start position:0% +matter whether you go from the end of +the path and move your way to the other + + align:start position:0% +the path and move your way to the other + + + align:start position:0% +the path and move your way to the other +end right or if you start at the + + align:start position:0% +end right or if you start at the + + + align:start position:0% +end right or if you start at the +beginning of the path and go to the end + + align:start position:0% +beginning of the path and go to the end + + + align:start position:0% +beginning of the path and go to the end +and so when you see it that way I think + + align:start position:0% +and so when you see it that way I think + + + align:start position:0% +and so when you see it that way I think +reverse mode and forward mode don't seem + + align:start position:0% +reverse mode and forward mode don't seem + + + align:start position:0% +reverse mode and forward mode don't seem +so mysterious I mean I think it's pretty + + align:start position:0% +so mysterious I mean I think it's pretty + + + align:start position:0% +so mysterious I mean I think it's pretty +clear if you stand back here the world + + align:start position:0% +clear if you stand back here the world + + + align:start position:0% +clear if you stand back here the world +doesn't care if you go cosine x * 1 over + + align:start position:0% +doesn't care if you go cosine x * 1 over + + + align:start position:0% +doesn't care if you go cosine x * 1 over +y * 1 or if you go 1 * 1 over y * cosine + + align:start position:0% +y * 1 or if you go 1 * 1 over y * cosine + + + align:start position:0% +y * 1 or if you go 1 * 1 over y * cosine +X and uh the only issue is if these were + + align:start position:0% +X and uh the only issue is if these were + + + align:start position:0% +X and uh the only issue is if these were +matrices how would you do it but um I + + align:start position:0% +matrices how would you do it but um I + + + align:start position:0% +matrices how would you do it but um I +think you'd all get the idea that you + + align:start position:0% +think you'd all get the idea that you + + + align:start position:0% +think you'd all get the idea that you +know if the path products like if this + + align:start position:0% +know if the path products like if this + + + align:start position:0% +know if the path products like if this +was a b and c if these were I'm using + + align:start position:0% +was a b and c if these were I'm using + + + align:start position:0% +was a b and c if these were I'm using +capital letters to have you denote + + align:start position:0% +capital letters to have you denote + + + align:start position:0% +capital letters to have you denote +matrices then the world doesn't really + + align:start position:0% +matrices then the world doesn't really + + + align:start position:0% +matrices then the world doesn't really +care if you were to calculate if you + + align:start position:0% +care if you were to calculate if you + + + align:start position:0% +care if you were to calculate if you +Traverse this way and you saw the a + + align:start position:0% +Traverse this way and you saw the a + + + align:start position:0% +Traverse this way and you saw the a +first and then when you multiply by B + + align:start position:0% +first and then when you multiply by B + + + align:start position:0% +first and then when you multiply by B +and then you see the C last or if you + + align:start position:0% +and then you see the C last or if you + + + align:start position:0% +and then you see the C last or if you +went backwards right and you pick up the + + align:start position:0% +went backwards right and you pick up the + + + align:start position:0% +went backwards right and you pick up the +C first and then you then multiply by B + + align:start position:0% +C first and then you then multiply by B + + + align:start position:0% +C first and then you then multiply by B +on the left and then finally uh a on the + + align:start position:0% +on the left and then finally uh a on the + + + align:start position:0% +on the left and then finally uh a on the +Left Right the the as long as you have + + align:start position:0% +Left Right the the as long as you have + + + align:start position:0% +Left Right the the as long as you have +an associative system right it doesn't + + align:start position:0% +an associative system right it doesn't + + + align:start position:0% +an associative system right it doesn't +matter which way you do those multiplies + + align:start position:0% +matter which way you do those multiplies + + + align:start position:0% +matter which way you do those multiplies +so as long as you can Traverse the paths + + align:start position:0% +so as long as you can Traverse the paths + + + align:start position:0% +so as long as you can Traverse the paths +either from forward to back or back to + + align:start position:0% +either from forward to back or back to + + + align:start position:0% +either from forward to back or back to +forward or or by the way you can not + + align:start position:0% +forward or or by the way you can not + + + align:start position:0% +forward or or by the way you can not +that this happens very much but you + + align:start position:0% +that this happens very much but you + + + align:start position:0% +that this happens very much but you +could even Traverse paths from the + + align:start position:0% +could even Traverse paths from the + + + align:start position:0% +could even Traverse paths from the +middle outward but right and as long as + + align:start position:0% +middle outward but right and as long as + + + align:start position:0% +middle outward but right and as long as +you put the right things in the right + + align:start position:0% +you put the right things in the right + + + align:start position:0% +you put the right things in the right +order there's no rule of the universe + + align:start position:0% +order there's no rule of the universe + + + align:start position:0% +order there's no rule of the universe +that says you have to go from the + + align:start position:0% +that says you have to go from the + + + align:start position:0% +that says you have to go from the +beginning to the end or the end to the + + align:start position:0% +beginning to the end or the end to the + + + align:start position:0% +beginning to the end or the end to the +beginning or you can't go middle outward + + align:start position:0% +beginning or you can't go middle outward + + + align:start position:0% +beginning or you can't go middle outward +right the beauty of associativity is + + align:start position:0% +right the beauty of associativity is + + + align:start position:0% +right the beauty of associativity is +these path products will work just any + + align:start position:0% +these path products will work just any + + + align:start position:0% +these path products will work just any +which way you do it okay so that's one + + align:start position:0% +which way you do it okay so that's one + + + align:start position:0% +which way you do it okay so that's one +way to look at uh at at at at for you + + align:start position:0% +way to look at uh at at at at for you + + + align:start position:0% +way to look at uh at at at at for you +know at automatic differentiation both + + align:start position:0% +know at automatic differentiation both + + + align:start position:0% +know at automatic differentiation both +forward and reverse is to think of it in + + align:start position:0% +forward and reverse is to think of it in + + + align:start position:0% +forward and reverse is to think of it in +terms of these path products that really + + align:start position:0% +terms of these path products that really + + + align:start position:0% +terms of these path products that really +don't care how you go now as far as + + align:start position:0% +don't care how you go now as far as + + + align:start position:0% +don't care how you go now as far as +implementations are concerned so one + + align:start position:0% +implementations are concerned so one + + + align:start position:0% +implementations are concerned so one +thing I'll do is I'll move the black the + + align:start position:0% +thing I'll do is I'll move the black the + + + align:start position:0% +thing I'll do is I'll move the black the +laptop over a little bit so that Steph + + align:start position:0% +laptop over a little bit so that Steph + + + align:start position:0% +laptop over a little bit so that Steph +has a chance of seeing what we're doing + + align:start position:0% +has a chance of seeing what we're doing + + + align:start position:0% +has a chance of seeing what we're doing +it might be a weird angle but you know + + align:start position:0% +it might be a weird angle but you know + + + align:start position:0% +it might be a weird angle but you know +what let's do a little better let's move + + align:start position:0% +what let's do a little better let's move + + + align:start position:0% +what let's do a little better let's move +the whole + + align:start position:0% +the whole + + + align:start position:0% +the whole +laptop so Stephen can see it a little + + align:start position:0% +laptop so Stephen can see it a little + + + align:start position:0% +laptop so Stephen can see it a little +bit better if I if I use these boards + + align:start position:0% +bit better if I if I use these boards + + + align:start position:0% +bit better if I if I use these boards +here okay + + align:start position:0% +here okay + + + align:start position:0% +here okay +so + + align:start position:0% +so + + + align:start position:0% +so +uh so so + + align:start position:0% +uh so so + + + align:start position:0% +uh so so +let's + + align:start position:0% + + + + align:start position:0% + +so so let's take a little bit of a + + align:start position:0% +so so let's take a little bit of a + + + align:start position:0% +so so let's take a little bit of a +closer view of implementation of forward + + align:start position:0% +closer view of implementation of forward + + + align:start position:0% +closer view of implementation of forward +mode now that we kind of have this sort + + align:start position:0% +mode now that we kind of have this sort + + + align:start position:0% +mode now that we kind of have this sort +of understanding of what it is we're + + align:start position:0% +of understanding of what it is we're + + + align:start position:0% +of understanding of what it is we're +trying to do so how would we implement + + align:start position:0% +trying to do so how would we implement + + + align:start position:0% +trying to do so how would we implement +this + + align:start position:0% + + + + align:start position:0% + +thing right so how are we going to do + + align:start position:0% +thing right so how are we going to do + + + align:start position:0% +thing right so how are we going to do +this well let me um focus on sort of + + align:start position:0% +this well let me um focus on sort of + + + align:start position:0% +this well let me um focus on sort of +being in the middle right so suppose we + + align:start position:0% +being in the middle right so suppose we + + + align:start position:0% +being in the middle right so suppose we +have a lot of stuff have happened you + + align:start position:0% +have a lot of stuff have happened you + + + align:start position:0% +have a lot of stuff have happened you +know I don't know what's going on and + + align:start position:0% +know I don't know what's going on and + + + align:start position:0% +know I don't know what's going on and +you know we're at the point in time + + align:start position:0% +you know we're at the point in time + + + align:start position:0% +you know we're at the point in time +where we're here right and uh what we + + align:start position:0% +where we're here right and uh what we + + + align:start position:0% +where we're here right and uh what we +want to do let me call this I'll call + + align:start position:0% +want to do let me call this I'll call + + + align:start position:0% +want to do let me call this I'll call +this x just just uh it's not it's not an + + align:start position:0% +this x just just uh it's not it's not an + + + align:start position:0% +this x just just uh it's not it's not an +input at the beginning it's just X's + + align:start position:0% +input at the beginning it's just X's + + + align:start position:0% +input at the beginning it's just X's +somewhere in the middle right and we're + + align:start position:0% +somewhere in the middle right and we're + + + align:start position:0% +somewhere in the middle right and we're +going to calculate an output we're going + + align:start position:0% +going to calculate an output we're going + + + align:start position:0% +going to calculate an output we're going +to calculate F ofx right and so whatever + + align:start position:0% +to calculate F ofx right and so whatever + + + align:start position:0% +to calculate F ofx right and so whatever +comes in + + align:start position:0% +comes in + + + align:start position:0% +comes in +here we're going to somehow have it Go + + align:start position:0% +here we're going to somehow have it Go + + + align:start position:0% +here we're going to somehow have it Go +and we're g to we're right we're we're + + align:start position:0% +and we're g to we're right we're we're + + + align:start position:0% +and we're g to we're right we're we're +we're starting we're taking a path + + align:start position:0% +we're starting we're taking a path + + + align:start position:0% +we're starting we're taking a path +product right and so we've come up to + + align:start position:0% +product right and so we've come up to + + + align:start position:0% +product right and so we've come up to +here and if you just kind of think I + + align:start position:0% +here and if you just kind of think I + + + align:start position:0% +here and if you just kind of think I +don't know is this recursive thinking or + + align:start position:0% +don't know is this recursive thinking or + + + align:start position:0% +don't know is this recursive thinking or +is this just how how one should think + + align:start position:0% +is this just how how one should think + + + align:start position:0% +is this just how how one should think +about any computer program uh but you + + align:start position:0% +about any computer program uh but you + + + align:start position:0% +about any computer program uh but you +know one way or another you've gotten to + + align:start position:0% +know one way or another you've gotten to + + + align:start position:0% +know one way or another you've gotten to +here and you have the path product at up + + align:start position:0% +here and you have the path product at up + + + align:start position:0% +here and you have the path product at up +until here right so we start out like + + align:start position:0% +until here right so we start out like + + + align:start position:0% +until here right so we start out like +maybe call it an inductive hypothesis or + + align:start position:0% +maybe call it an inductive hypothesis or + + + align:start position:0% +maybe call it an inductive hypothesis or +whatever you'd like to say we know the + + align:start position:0% +whatever you'd like to say we know the + + + align:start position:0% +whatever you'd like to say we know the +path product up to here right so if I + + align:start position:0% +path product up to here right so if I + + + align:start position:0% +path product up to here right so if I +knew the path product up to here and I + + align:start position:0% +knew the path product up to here and I + + + align:start position:0% +knew the path product up to here and I +was going forward mode what is what's + + align:start position:0% +was going forward mode what is what's + + + align:start position:0% +was going forward mode what is what's +the next PATH + + align:start position:0% +the next PATH + + + align:start position:0% +the next PATH +product right so suppose I know this + + align:start position:0% +product right so suppose I know this + + + align:start position:0% +product right so suppose I know this +path product you know let's call it P + + align:start position:0% +path product you know let's call it P + + + align:start position:0% +path product you know let's call it P +for product okay what's the path product + + align:start position:0% + + + + align:start position:0% + +here right yeah exactly it's just it + + align:start position:0% +here right yeah exactly it's just it + + + align:start position:0% +here right yeah exactly it's just it +what what is the that + + align:start position:0% +what what is the that + + + align:start position:0% +what what is the that +right F Prime Times the previous exactly + + align:start position:0% +right F Prime Times the previous exactly + + + align:start position:0% +right F Prime Times the previous exactly +right so one way or another I need a + + align:start position:0% +right so one way or another I need a + + + align:start position:0% +right so one way or another I need a +data structure that + + align:start position:0% +data structure that + + + align:start position:0% +data structure that +um uh I need a data structure that that + + align:start position:0% +um uh I need a data structure that that + + + align:start position:0% +um uh I need a data structure that that +will take the the value here and the + + align:start position:0% +will take the the value here and the + + + align:start position:0% +will take the the value here and the +path + + align:start position:0% +path + + + align:start position:0% +path +product path product right and it'll + + align:start position:0% +product path product right and it'll + + + align:start position:0% +product path product right and it'll +give + + align:start position:0% +give + + + align:start position:0% +give +me + + align:start position:0% +me + + + align:start position:0% +me +U it it'll give me f of the value if I + + align:start position:0% +U it it'll give me f of the value if I + + + align:start position:0% +U it it'll give me f of the value if I +want to run if I just want to run the + + align:start position:0% +want to run if I just want to run the + + + align:start position:0% +want to run if I just want to run the +algorithm right and I need the path + + align:start position:0% +algorithm right and I need the path + + + align:start position:0% +algorithm right and I need the path +product time + + align:start position:0% + + + + align:start position:0% + +frime and I I want to multiply in this + + align:start position:0% +frime and I I want to multiply in this + + + align:start position:0% +frime and I I want to multiply in this +order right and so in some sense this is + + align:start position:0% +order right and so in some sense this is + + + align:start position:0% +order right and so in some sense this is +what the whole dual number system thing + + align:start position:0% +what the whole dual number system thing + + + align:start position:0% +what the whole dual number system thing +is doing this is another way to look at + + align:start position:0% +is doing this is another way to look at + + + align:start position:0% +is doing this is another way to look at +the Dual numbers right so there's lots + + align:start position:0% +the Dual numbers right so there's lots + + + align:start position:0% +the Dual numbers right so there's lots +and lots of ways to understand what I + + align:start position:0% +and lots of ways to understand what I + + + align:start position:0% +and lots of ways to understand what I +just showed you with dual numbers but + + align:start position:0% +just showed you with dual numbers but + + + align:start position:0% +just showed you with dual numbers but +it's really nothing more than taking + + align:start position:0% +it's really nothing more than taking + + + align:start position:0% +it's really nothing more than taking +your path products and with you know + + align:start position:0% +your path products and with you know + + + align:start position:0% +your path products and with you know +with the value and uh you could see the + + align:start position:0% +with the value and uh you could see the + + + align:start position:0% +with the value and uh you could see the +the reason why I'm showing you this way + + align:start position:0% +the reason why I'm showing you this way + + + align:start position:0% +the reason why I'm showing you this way +is that um if you're executing a + + align:start position:0% +is that um if you're executing a + + + align:start position:0% +is that um if you're executing a +computer program where you want to + + align:start position:0% +computer program where you want to + + + align:start position:0% +computer program where you want to +literally you want you want you know the + + align:start position:0% +literally you want you want you know the + + + align:start position:0% +literally you want you want you know the +main thing the computer program was + + align:start position:0% +main thing the computer program was + + + align:start position:0% +main thing the computer program was +meant to do was to calculate F ofx and + + align:start position:0% +meant to do was to calculate F ofx and + + + align:start position:0% +meant to do was to calculate F ofx and +now this additional extra thing we + + align:start position:0% +now this additional extra thing we + + + align:start position:0% +now this additional extra thing we +wanted to do you know maybe we're doing + + align:start position:0% +wanted to do you know maybe we're doing + + + align:start position:0% +wanted to do you know maybe we're doing +grading to scent and machine learning or + + align:start position:0% +grading to scent and machine learning or + + + align:start position:0% +grading to scent and machine learning or +who knows what we're doing we want the + + align:start position:0% +who knows what we're doing we want the + + + align:start position:0% +who knows what we're doing we want the +derivative to to kind of happen at the + + align:start position:0% +derivative to to kind of happen at the + + + align:start position:0% +derivative to to kind of happen at the +same time then all we have to do is + + align:start position:0% +same time then all we have to do is + + + align:start position:0% +same time then all we have to do is +overload our program that was already + + align:start position:0% +overload our program that was already + + + align:start position:0% +overload our program that was already +happy to calculate the F of the value + + align:start position:0% +happy to calculate the F of the value + + + align:start position:0% +happy to calculate the F of the value +and then tack along the path product and + + align:start position:0% +and then tack along the path product and + + + align:start position:0% +and then tack along the path product and +append the path product and you know by + + align:start position:0% +append the path product and you know by + + + align:start position:0% +append the path product and you know by +with this extra multiply right and so + + align:start position:0% +with this extra multiply right and so + + + align:start position:0% +with this extra multiply right and so +this is how the this is one way of + + align:start position:0% +this is how the this is one way of + + + align:start position:0% +this is how the this is one way of +looking as to how the whole dual number + + align:start position:0% +looking as to how the whole dual number + + + align:start position:0% +looking as to how the whole dual number +thing is is actually working right and + + align:start position:0% +thing is is actually working right and + + + align:start position:0% +thing is is actually working right and +so um in symbols if I had X comma P then + + align:start position:0% +so um in symbols if I had X comma P then + + + align:start position:0% +so um in symbols if I had X comma P then +on the next step I'm going to have uh F + + align:start position:0% +on the next step I'm going to have uh F + + + align:start position:0% +on the next step I'm going to have uh F +ofx and fime of x * P right and so + + align:start position:0% +ofx and fime of x * P right and so + + + align:start position:0% +ofx and fime of x * P right and so +that's how we can carry forward this + + align:start position:0% +that's how we can carry forward this + + + align:start position:0% +that's how we can carry forward this +path product idea okay um and + + align:start position:0% +path product idea okay um and + + + align:start position:0% +path product idea okay um and +um okay and uh now let let's talk about + + align:start position:0% +um okay and uh now let let's talk about + + + align:start position:0% +um okay and uh now let let's talk about +how to start this whole thing so this + + align:start position:0% +how to start this whole thing so this + + + align:start position:0% +how to start this whole thing so this +was in the middle how should we + + align:start position:0% +was in the middle how should we + + + align:start position:0% +was in the middle how should we +start right so what x comma what should + + align:start position:0% +start right so what x comma what should + + + align:start position:0% +start right so what x comma what should +I put here so that the first step just + + align:start position:0% +I put here so that the first step just + + + align:start position:0% +I put here so that the first step just +works is it obvious what what what we + + align:start position:0% +works is it obvious what what what we + + + align:start position:0% +works is it obvious what what what we +should just start with or or another way + + align:start position:0% +should just start with or or another way + + + align:start position:0% +should just start with or or another way +to say it is what should be what should + + align:start position:0% +to say it is what should be what should + + + align:start position:0% +to say it is what should be what should +be the the path product of of a path of + + align:start position:0% +be the the path product of of a path of + + + align:start position:0% +be the the path product of of a path of +length + + align:start position:0% +length + + + align:start position:0% +length +zero do people ever think about these + + align:start position:0% +zero do people ever think about these + + + align:start position:0% +zero do people ever think about these +things like what if I ask you what is + + align:start position:0% +things like what if I ask you what is + + + align:start position:0% +things like what if I ask you what is +the sum of the empty vector and I told + + align:start position:0% +the sum of the empty vector and I told + + + align:start position:0% +the sum of the empty vector and I told +you there's only one right answer to + + align:start position:0% +you there's only one right answer to + + + align:start position:0% +you there's only one right answer to +that what's the right + + align:start position:0% +that what's the right + + + align:start position:0% +that what's the right +answer of the sum of an empty Vector a + + align:start position:0% +answer of the sum of an empty Vector a + + + align:start position:0% +answer of the sum of an empty Vector a +vector of length + + align:start position:0% +vector of length + + + align:start position:0% +vector of length +zero zero right the identity element is + + align:start position:0% +zero zero right the identity element is + + + align:start position:0% +zero zero right the identity element is +the only thing that makes sense right + + align:start position:0% +the only thing that makes sense right + + + align:start position:0% +the only thing that makes sense right +why because because you always want the + + align:start position:0% +why because because you always want the + + + align:start position:0% +why because because you always want the +sum from I = 1 to k + 1 + + align:start position:0% +sum from I = 1 to k + 1 + + + align:start position:0% +sum from I = 1 to k + 1 +of x i to equal you know x k + 1 plus + + align:start position:0% +of x i to equal you know x k + 1 plus + + + align:start position:0% +of x i to equal you know x k + 1 plus +the sum from I = 1 to K right and if you + + align:start position:0% +the sum from I = 1 to K right and if you + + + align:start position:0% +the sum from I = 1 to K right and if you +would make this work for k equals Zer + + align:start position:0% +would make this work for k equals Zer + + + align:start position:0% +would make this work for k equals Zer +it's perfect if if if and what's the + + align:start position:0% +it's perfect if if if and what's the + + + align:start position:0% +it's perfect if if if and what's the +empty + + align:start position:0% +empty + + + align:start position:0% +empty +product it's one right you know the + + align:start position:0% +product it's one right you know the + + + align:start position:0% +product it's one right you know the +determinant of a 0 by Z Matrix also + + align:start position:0% +determinant of a 0 by Z Matrix also + + + align:start position:0% +determinant of a 0 by Z Matrix also +should be one and then the the pl + + align:start position:0% +should be one and then the the pl + + + align:start position:0% +should be one and then the the pl +expansion works okay so what's the empty + + align:start position:0% +expansion works okay so what's the empty + + + align:start position:0% +expansion works okay so what's the empty +path product then um so so you know how + + align:start position:0% +path product then um so so you know how + + + align:start position:0% +path product then um so so you know how +should we in effect how if if if when + + align:start position:0% +should we in effect how if if if when + + + align:start position:0% +should we in effect how if if if when +you sum if you're summing up a vector + + align:start position:0% +you sum if you're summing up a vector + + + align:start position:0% +you sum if you're summing up a vector +right you initialize the variable to + + align:start position:0% +right you initialize the variable to + + + align:start position:0% +right you initialize the variable to +zero and then you start adding in + + align:start position:0% +zero and then you start adding in + + + align:start position:0% +zero and then you start adding in +numbers right so what's the empty what's + + align:start position:0% +numbers right so what's the empty what's + + + align:start position:0% +numbers right so what's the empty what's +the empty the empty + + align:start position:0% +the empty the empty + + + align:start position:0% +the empty the empty +start one exactly so there are number of + + align:start position:0% +start one exactly so there are number of + + + align:start position:0% +start one exactly so there are number of +ways to interpret this you could think + + align:start position:0% +ways to interpret this you could think + + + align:start position:0% +ways to interpret this you could think +of this as the sloping what but this is + + align:start position:0% +of this as the sloping what but this is + + + align:start position:0% +of this as the sloping what but this is +not a bad way to think about it again + + align:start position:0% +not a bad way to think about it again + + + align:start position:0% +not a bad way to think about it again +you could think of it in multiple ways + + align:start position:0% +you could think of it in multiple ways + + + align:start position:0% +you could think of it in multiple ways +but you start with X comma one to see + + align:start position:0% +but you start with X comma one to see + + + align:start position:0% +but you start with X comma one to see +the operation and then um at every step + + align:start position:0% +the operation and then um at every step + + + align:start position:0% +the operation and then um at every step +you do this and at the very end you get + + align:start position:0% +you do this and at the very end you get + + + align:start position:0% +you do this and at the very end you get +the derivatives that you're looking for + + align:start position:0% +the derivatives that you're looking for + + + align:start position:0% +the derivatives that you're looking for +okay so that's forward mode and um and + + align:start position:0% +okay so that's forward mode and um and + + + align:start position:0% +okay so that's forward mode and um and +and it works just great okay a quick + + align:start position:0% +and it works just great okay a quick + + + align:start position:0% +and it works just great okay a quick +check though U suppose I had f ofx as a + + align:start position:0% +check though U suppose I had f ofx as a + + + align:start position:0% +check though U suppose I had f ofx as a +constant like + + align:start position:0% +constant like + + + align:start position:0% +constant like +two + + align:start position:0% +two + + + align:start position:0% +two +right right and then + + align:start position:0% + + + + align:start position:0% + +so um I feed it in X comma P what what's + + align:start position:0% +so um I feed it in X comma P what what's + + + align:start position:0% +so um I feed it in X comma P what what's +the + + align:start position:0% + + + + align:start position:0% + +output what what are the what are the + + align:start position:0% +output what what are the what are the + + + align:start position:0% +output what what are the what are the +two numbers that would come out if um + + align:start position:0% +two numbers that would come out if um + + + align:start position:0% +two numbers that would come out if um +anywhere in the middle of my calculation + + align:start position:0% +anywhere in the middle of my calculation + + + align:start position:0% +anywhere in the middle of my calculation +I started with XP and I applied this + + align:start position:0% +I started with XP and I applied this + + + align:start position:0% +I started with XP and I applied this +constant + + align:start position:0% +constant + + + align:start position:0% +constant +function to zero right doesn't even + + align:start position:0% +function to zero right doesn't even + + + align:start position:0% +function to zero right doesn't even +matter what the input is that's right + + align:start position:0% +matter what the input is that's right + + + align:start position:0% +matter what the input is that's right +because it's it's a constant function it + + align:start position:0% +because it's it's a constant function it + + + align:start position:0% +because it's it's a constant function it +doesn't + + align:start position:0% +doesn't + + + align:start position:0% +doesn't +care + + align:start position:0% +care + + + align:start position:0% +care +okay + + align:start position:0% + + + + align:start position:0% + +um and uh okay so this is sort of the + + align:start position:0% +um and uh okay so this is sort of the + + + align:start position:0% +um and uh okay so this is sort of the +one Arrow case in forward + + align:start position:0% +one Arrow case in forward + + + align:start position:0% +one Arrow case in forward +mode um maybe it's worthwhile to you + + align:start position:0% +mode um maybe it's worthwhile to you + + + align:start position:0% +mode um maybe it's worthwhile to you +know to to quickly talk about um the the + + align:start position:0% +know to to quickly talk about um the the + + + align:start position:0% +know to to quickly talk about um the the +the the multiple Arrow case so for + + align:start position:0% +the the multiple Arrow case so for + + + align:start position:0% +the the multiple Arrow case so for +example suppose I + + align:start position:0% +example suppose I + + + align:start position:0% +example suppose I +have uh let's say I had a p and + + align:start position:0% +have uh let's say I had a p and + + + align:start position:0% +have uh let's say I had a p and +BQ right and U and let's say I had two + + align:start position:0% +BQ right and U and let's say I had two + + + align:start position:0% +BQ right and U and let's say I had two +arrows going in right and I had Z is + + align:start position:0% +arrows going in right and I had Z is + + + align:start position:0% +arrows going in right and I had Z is +some function of two variables like like + + align:start position:0% +some function of two variables like like + + + align:start position:0% +some function of two variables like like +like I did over there maybe the sum or + + align:start position:0% +like I did over there maybe the sum or + + + align:start position:0% +like I did over there maybe the sum or +the product or divide or you know this + + align:start position:0% +the product or divide or you know this + + + align:start position:0% +the product or divide or you know this +or any function of of of of two + + align:start position:0% +or any function of of of of two + + + align:start position:0% +or any function of of of of two +variables right so U this will be the + + align:start position:0% +variables right so U this will be the + + + align:start position:0% +variables right so U this will be the +the one-step derivative of course this + + align:start position:0% +the one-step derivative of course this + + + align:start position:0% +the one-step derivative of course this +will be um DZ + + align:start position:0% +will be um DZ + + + align:start position:0% +will be um DZ +da right and this will be well I don't + + align:start position:0% +da right and this will be well I don't + + + align:start position:0% +da right and this will be well I don't +know what the best way to write this is + + align:start position:0% +know what the best way to write this is + + + align:start position:0% +know what the best way to write this is +but DZ dzdb is probably as good away as + + align:start position:0% +but DZ dzdb is probably as good away as + + + align:start position:0% +but DZ dzdb is probably as good away as +any so now I'm not thinking of a and b + + align:start position:0% +any so now I'm not thinking of a and b + + + align:start position:0% +any so now I'm not thinking of a and b +as numbers but I'm thinking of them as + + align:start position:0% +as numbers but I'm thinking of them as + + + align:start position:0% +as numbers but I'm thinking of them as +as symbols for the moment or I'm + + align:start position:0% +as symbols for the moment or I'm + + + align:start position:0% +as symbols for the moment or I'm +imagining that one way or another I know + + align:start position:0% +imagining that one way or another I know + + + align:start position:0% +imagining that one way or another I know +the derivative of this at least one way + + align:start position:0% +the derivative of this at least one way + + + align:start position:0% +the derivative of this at least one way +or another I know the derivative of this + + align:start position:0% +or another I know the derivative of this + + + align:start position:0% +or another I know the derivative of this +function you know with respect to this + + align:start position:0% +function you know with respect to this + + + align:start position:0% +function you know with respect to this +variable somehow right like I I mean + + align:start position:0% +variable somehow right like I I mean + + + align:start position:0% +variable somehow right like I I mean +just to give you a quick example that + + align:start position:0% +just to give you a quick example that + + + align:start position:0% +just to give you a quick example that +this is not so complicated uh if if if F + + align:start position:0% +this is not so complicated uh if if if F + + + align:start position:0% +this is not so complicated uh if if if F +was the plus function right if this is a + + align:start position:0% +was the plus function right if this is a + + + align:start position:0% +was the plus function right if this is a +plus b what would I put here and + + align:start position:0% +plus b what would I put here and + + + align:start position:0% +plus b what would I put here and +here again simple question one in one + + align:start position:0% +here again simple question one in one + + + align:start position:0% +here again simple question one in one +and slightly more complicated but not by + + align:start position:0% +and slightly more complicated but not by + + + align:start position:0% +and slightly more complicated but not by +much if uh this was the product function + + align:start position:0% +much if uh this was the product function + + + align:start position:0% +much if uh this was the product function +a * B right what would I put here here + + align:start position:0% +a * B right what would I put here here + + + align:start position:0% +a * B right what would I put here here +and what would I put + + align:start position:0% +and what would I put + + + align:start position:0% +and what would I put +here wait say it + + align:start position:0% +here wait say it + + + align:start position:0% +here wait say it +again b and a perfect right so the point + + align:start position:0% +again b and a perfect right so the point + + + align:start position:0% +again b and a perfect right so the point +is for lots of basic functions it's very + + align:start position:0% +is for lots of basic functions it's very + + + align:start position:0% +is for lots of basic functions it's very +easy to know what to put what to put + + align:start position:0% +easy to know what to put what to put + + + align:start position:0% +easy to know what to put what to put +here okay and so you've got these these + + align:start position:0% +here okay and so you've got these these + + + align:start position:0% +here okay and so you've got these these +these multiple arrows going + + align:start position:0% +these multiple arrows going + + + align:start position:0% +these multiple arrows going +in + + align:start position:0% +in + + + align:start position:0% +in +and + + align:start position:0% +and + + + align:start position:0% +and +um yeah you have these multiple arrows + + align:start position:0% +um yeah you have these multiple arrows + + + align:start position:0% +um yeah you have these multiple arrows +in and of course um what we're just + + align:start position:0% +in and of course um what we're just + + + align:start position:0% +in and of course um what we're just +going to do is is we're just going to + + align:start position:0% +going to do is is we're just going to + + + align:start position:0% +going to do is is we're just going to +add the results right so did I write it + + align:start position:0% +add the results right so did I write it + + + align:start position:0% +add the results right so did I write it +out um yeah in effect yes so let me just + + align:start position:0% +out um yeah in effect yes so let me just + + + align:start position:0% +out um yeah in effect yes so let me just +say that if this goes in what we really + + align:start position:0% +say that if this goes in what we really + + + align:start position:0% +say that if this goes in what we really +want to come out is is the Z which is of + + align:start position:0% +want to come out is is the Z which is of + + + align:start position:0% +want to come out is is the Z which is of +course F of A and + + align:start position:0% +course F of A and + + + align:start position:0% +course F of A and +B okay and then what we want to do is um + + align:start position:0% +B okay and then what we want to do is um + + + align:start position:0% +B okay and then what we want to do is um +is is is to continue the path um we + + align:start position:0% +is is is to continue the path um we + + + align:start position:0% +is is is to continue the path um we +Let's see we we + + align:start position:0% +Let's see we we + + + align:start position:0% +Let's see we we +had did I write this correctly um Let me + + align:start position:0% +had did I write this correctly um Let me + + + align:start position:0% +had did I write this correctly um Let me +let me get this right so uh + + align:start position:0% +let me get this right so uh + + + align:start position:0% +let me get this right so uh +let's see so so if I + + align:start position:0% +let's see so so if I + + + align:start position:0% +let's see so so if I +started with this then what oh yeah what + + align:start position:0% +started with this then what oh yeah what + + + align:start position:0% +started with this then what oh yeah what +I have to do is take oh I guess is this + + align:start position:0% +I have to do is take oh I guess is this + + + align:start position:0% +I have to do is take oh I guess is this +right I have to take P yeah yeah P * DZ + + align:start position:0% +right I have to take P yeah yeah P * DZ + + + align:start position:0% +right I have to take P yeah yeah P * DZ +da plus Q times yeah that's right dzb DB + + align:start position:0% +da plus Q times yeah that's right dzb DB + + + align:start position:0% +da plus Q times yeah that's right dzb DB +right and that's the right thing to do + + align:start position:0% +right and that's the right thing to do + + + align:start position:0% +right and that's the right thing to do +to carry forward the derivative right + + align:start position:0% +to carry forward the derivative right + + + align:start position:0% +to carry forward the derivative right +and so this is + + align:start position:0% +and so this is + + + align:start position:0% +and so this is +the right because this is exactly what + + align:start position:0% +the right because this is exactly what + + + align:start position:0% +the right because this is exactly what +the derivative would be over here or uh + + align:start position:0% +the derivative would be over here or uh + + + align:start position:0% +the derivative would be over here or uh +or or if you like you could just think + + align:start position:0% +or or if you like you could just think + + + align:start position:0% +or or if you like you could just think +of this as combining the paths the path + + align:start position:0% +of this as combining the paths the path + + + align:start position:0% +of this as combining the paths the path +products right so you could think of + + align:start position:0% +products right so you could think of + + + align:start position:0% +products right so you could think of +this from a calculus point of view that + + align:start position:0% +this from a calculus point of view that + + + align:start position:0% +this from a calculus point of view that +the the derivative right so so the + + align:start position:0% +the the derivative right so so the + + + align:start position:0% +the the derivative right so so the +calculus Viewpoint is that you know that + + align:start position:0% +calculus Viewpoint is that you know that + + + align:start position:0% +calculus Viewpoint is that you know that +the derivative of this with respect to + + align:start position:0% +the derivative of this with respect to + + + align:start position:0% +the derivative of this with respect to +that plus the derivative of this you the + + align:start position:0% +that plus the derivative of this you the + + + align:start position:0% +that plus the derivative of this you the +first variable then then times the + + align:start position:0% +first variable then then times the + + + align:start position:0% +first variable then then times the +second variable but the the path way + + align:start position:0% +second variable but the the path way + + + align:start position:0% +second variable but the the path way +which I think is almost easier to I mean + + align:start position:0% +which I think is almost easier to I mean + + + align:start position:0% +which I think is almost easier to I mean +it all depends on whether you like to + + align:start position:0% +it all depends on whether you like to + + + align:start position:0% +it all depends on whether you like to +think calculus first or you like to + + align:start position:0% +think calculus first or you like to + + + align:start position:0% +think calculus first or you like to +think paths first first but it's really + + align:start position:0% +think paths first first but it's really + + + align:start position:0% +think paths first first but it's really +just different words for for what in + + align:start position:0% +just different words for for what in + + + align:start position:0% +just different words for for what in +mathematics is the same thing that we're + + align:start position:0% +mathematics is the same thing that we're + + + align:start position:0% +mathematics is the same thing that we're +taking this path product and this path + + align:start position:0% +taking this path product and this path + + + align:start position:0% +taking this path product and this path +product and the rule is that anytime + + align:start position:0% +product and the rule is that anytime + + + align:start position:0% +product and the rule is that anytime +things come together just like the the + + align:start position:0% +things come together just like the the + + + align:start position:0% +things come together just like the the +one you saw here you just add them okay + + align:start position:0% +one you saw here you just add them okay + + + align:start position:0% +one you saw here you just add them okay +well I've run out of time I've got a + + align:start position:0% +well I've run out of time I've got a + + + align:start position:0% +well I've run out of time I've got a +whole bunch of more notes on reverse + + align:start position:0% +whole bunch of more notes on reverse + + + align:start position:0% +whole bunch of more notes on reverse +mode and how do you do the same thing + + align:start position:0% +mode and how do you do the same thing + + + align:start position:0% +mode and how do you do the same thing +with reverse mode um but I don't know + + align:start position:0% +with reverse mode um but I don't know + + + align:start position:0% +with reverse mode um but I don't know +whether I'm not going to see you before + + align:start position:0% +whether I'm not going to see you before + + + align:start position:0% +whether I'm not going to see you before +next week today so um you might see some + + align:start position:0% +next week today so um you might see some + + + align:start position:0% +next week today so um you might see some +version of this from from Chris or uh + + align:start position:0% +version of this from from Chris or uh + + + align:start position:0% +version of this from from Chris or uh +from D gorov or maybe from from Steven + + align:start position:0% +from D gorov or maybe from from Steven + + + align:start position:0% +from D gorov or maybe from from Steven +or otherwise I'll I'll give you my own + + align:start position:0% +or otherwise I'll I'll give you my own + + + align:start position:0% +or otherwise I'll I'll give you my own +version Anyway by the end of next week + + align:start position:0% +version Anyway by the end of next week + + + align:start position:0% +version Anyway by the end of next week +all right so um I'll wish you all a good + + align:start position:0% +all right so um I'll wish you all a good + + + align:start position:0% +all right so um I'll wish you all a good +weekend and um uh you'll be in good + + align:start position:0% +weekend and um uh you'll be in good + + + align:start position:0% +weekend and um uh you'll be in good +hands next + + align:start position:0% + + + + align:start position:0% + +week \ No newline at end of file diff --git a/rjAXFBWJt_o.txt b/rjAXFBWJt_o.txt new file mode 100644 index 0000000000000000000000000000000000000000..09aaed914952e5b0a77b7af55ea97faa83d3cab4 --- /dev/null +++ b/rjAXFBWJt_o.txt @@ -0,0 +1,2170 @@ +align:start position:0% + +Hi everyone. So today I'd like to talk + + align:start position:0% +Hi everyone. So today I'd like to talk + + + align:start position:0% +Hi everyone. So today I'd like to talk +about resonance frequency response. And + + align:start position:0% +about resonance frequency response. And + + + align:start position:0% +about resonance frequency response. And +specifically we're going to take a look + + align:start position:0% +specifically we're going to take a look + + + align:start position:0% +specifically we're going to take a look +at a couple differential equations. And + + align:start position:0% +at a couple differential equations. And + + + align:start position:0% +at a couple differential equations. And +we're asked to graph the amplitude + + align:start position:0% +we're asked to graph the amplitude + + + align:start position:0% +we're asked to graph the amplitude +response for each equation. And you'll + + align:start position:0% +response for each equation. And you'll + + + align:start position:0% +response for each equation. And you'll +note that these equations A, B, and C + + align:start position:0% +note that these equations A, B, and C + + + align:start position:0% +note that these equations A, B, and C +have varying amounts of damp uh damping. + + align:start position:0% +have varying amounts of damp uh damping. + + + align:start position:0% +have varying amounts of damp uh damping. +So for part a we're asked to uh plot the + + align:start position:0% +So for part a we're asked to uh plot the + + + align:start position:0% +So for part a we're asked to uh plot the +amplitude response for x dot dot + 4x= f + + align:start position:0% +amplitude response for x dot dot + 4x= f + + + align:start position:0% +amplitude response for x dot dot + 4x= f +cosine omega t. For part b it's the same + + align:start position:0% +cosine omega t. For part b it's the same + + + align:start position:0% +cosine omega t. For part b it's the same +equation. However we have an x dot term + + align:start position:0% +equation. However we have an x dot term + + + align:start position:0% +equation. However we have an x dot term +added. For part c again we've increased + + align:start position:0% +added. For part c again we've increased + + + align:start position:0% +added. For part c again we've increased +the damping. So now we have 6x dot. And + + align:start position:0% +the damping. So now we have 6x dot. And + + + align:start position:0% +the damping. So now we have 6x dot. And +then lastly for part d uh we'd like to + + align:start position:0% +then lastly for part d uh we'd like to + + + align:start position:0% +then lastly for part d uh we'd like to +discuss the resonance for each system. + + align:start position:0% +discuss the resonance for each system. + + + align:start position:0% +discuss the resonance for each system. +So I'll let you work out this problem + + align:start position:0% +So I'll let you work out this problem + + + align:start position:0% +So I'll let you work out this problem +and I'll be back in a moment. + + align:start position:0% + + + + align:start position:0% + +Hi everyone, welcome back. So for part + + align:start position:0% +Hi everyone, welcome back. So for part + + + align:start position:0% +Hi everyone, welcome back. So for part +A, we're asked to graph the amplitude + + align:start position:0% +A, we're asked to graph the amplitude + + + align:start position:0% +A, we're asked to graph the amplitude +response to the differential equation x + + align:start position:0% +response to the differential equation x + + + align:start position:0% +response to the differential equation x +dot dot + + + align:start position:0% +dot dot + + + + align:start position:0% +dot dot + +4x= f cosine omega t. + + align:start position:0% + + + + align:start position:0% + +And from a previous uh recitation uh we + + align:start position:0% +And from a previous uh recitation uh we + + + align:start position:0% +And from a previous uh recitation uh we +already wrote down the particular + + align:start position:0% +already wrote down the particular + + + align:start position:0% +already wrote down the particular +response to this differential equation. + + align:start position:0% +response to this differential equation. + + + align:start position:0% +response to this differential equation. +So I'm just going to write down the + + align:start position:0% +So I'm just going to write down the + + + align:start position:0% +So I'm just going to write down the +particular + + align:start position:0% + + + + align:start position:0% + +response which has the form + + align:start position:0% +response which has the form + + + align:start position:0% +response which has the form +f minus omega^ + + align:start position:0% +f minus omega^ + + + align:start position:0% +f minus omega^ +2 cosine omega + + align:start position:0% +2 cosine omega + + + align:start position:0% +2 cosine omega +t. Now the amplitude response is defined + + align:start position:0% +t. Now the amplitude response is defined + + + align:start position:0% +t. Now the amplitude response is defined +as a + + align:start position:0% + + + + align:start position:0% + +ratio and specifically it's the ratio of + + align:start position:0% +ratio and specifically it's the ratio of + + + align:start position:0% +ratio and specifically it's the ratio of +the output amplitude uh to a different + + align:start position:0% +the output amplitude uh to a different + + + align:start position:0% +the output amplitude uh to a different +of a differential equation to the input + + align:start position:0% +of a differential equation to the input + + + align:start position:0% +of a differential equation to the input +amplitude of a differential equation. So + + align:start position:0% +amplitude of a differential equation. So + + + align:start position:0% +amplitude of a differential equation. So +in the case at hand we have the output + + align:start position:0% +in the case at hand we have the output + + + align:start position:0% +in the case at hand we have the output +is a sinosoidal function whose amplitude + + align:start position:0% +is a sinosoidal function whose amplitude + + + align:start position:0% +is a sinosoidal function whose amplitude +is f / 4 minus omega^ 2. So it's the + + align:start position:0% + + + + align:start position:0% + +output divided by the + + align:start position:0% +output divided by the + + + align:start position:0% +output divided by the +input. These are both + + align:start position:0% + + + + align:start position:0% + +amplitudes. And in our case we have + + align:start position:0% +amplitudes. And in our case we have + + + align:start position:0% +amplitudes. And in our case we have +f / 4 - omega^ + + align:start position:0% +f / 4 - omega^ + + + align:start position:0% +f / 4 - omega^ +2. This is the output amplitude. And the + + align:start position:0% +2. This is the output amplitude. And the + + + align:start position:0% +2. This is the output amplitude. And the +input + + align:start position:0% +input + + + align:start position:0% +input +amplitude is just + + align:start position:0% +amplitude is just + + + align:start position:0% +amplitude is just +fnot. So we see when we compute this + + align:start position:0% +fnot. So we see when we compute this + + + align:start position:0% +fnot. So we see when we compute this +ratio the f knots divide + + align:start position:0% + + + + align:start position:0% + +out and at the end of the day we're left + + align:start position:0% +out and at the end of the day we're left + + + align:start position:0% +out and at the end of the day we're left +with 4 minus omega^ + + align:start position:0% +with 4 minus omega^ + + + align:start position:0% +with 4 minus omega^ +2. So I'm going to + + align:start position:0% +2. So I'm going to + + + align:start position:0% +2. So I'm going to +draw the amplitude response + + align:start position:0% + + + + align:start position:0% + +now. So we have + + align:start position:0% +now. So we have + + + align:start position:0% +now. So we have +omega and we see + + align:start position:0% +omega and we see + + + align:start position:0% +omega and we see +that when omega is equal to + + align:start position:0% +that when omega is equal to + + + align:start position:0% +that when omega is equal to +2 there's an + + align:start position:0% +2 there's an + + + align:start position:0% +2 there's an +asmtote. When omega is equal to zero we + + align:start position:0% +asmtote. When omega is equal to zero we + + + align:start position:0% +asmtote. When omega is equal to zero we +have 1/4. + + align:start position:0% + + + + align:start position:0% + +And specifically we have this tent-like + + align:start position:0% +And specifically we have this tent-like + + + align:start position:0% +And specifically we have this tent-like +function. So this is the amplitude + + align:start position:0% + + + + align:start position:0% + +response. So notice how when we drive + + align:start position:0% +response. So notice how when we drive + + + align:start position:0% +response. So notice how when we drive +the system with frequency 2, the + + align:start position:0% +the system with frequency 2, the + + + align:start position:0% +the system with frequency 2, the +amplitude response goes to infinity. + + align:start position:0% +amplitude response goes to infinity. + + + align:start position:0% +amplitude response goes to infinity. +Uh as a result we call this frequency uh + + align:start position:0% +Uh as a result we call this frequency uh + + + align:start position:0% +Uh as a result we call this frequency uh +the resonant + + align:start position:0% + + + + align:start position:0% + +frequency. Okay. So this concludes part + + align:start position:0% +frequency. Okay. So this concludes part + + + align:start position:0% +frequency. Okay. So this concludes part +A. For part + + align:start position:0% + + + + align:start position:0% + +B, we have uh a differential equation + + align:start position:0% +B, we have uh a differential equation + + + align:start position:0% +B, we have uh a differential equation +with damping. + + align:start position:0% + + + + align:start position:0% + +Now and to compute the uh particular + + align:start position:0% +Now and to compute the uh particular + + + align:start position:0% +Now and to compute the uh particular +solution we follow the standard + + align:start position:0% +solution we follow the standard + + + align:start position:0% +solution we follow the standard +procedure of first complexifying the + + align:start position:0% +procedure of first complexifying the + + + align:start position:0% +procedure of first complexifying the +right hand side and then using the + + align:start position:0% +right hand side and then using the + + + align:start position:0% +right hand side and then using the +exponential response + + align:start position:0% + + + + align:start position:0% + +formula. So I'm just going to write down + + align:start position:0% +formula. So I'm just going to write down + + + align:start position:0% +formula. So I'm just going to write down +the particular solution. + + align:start position:0% +the particular solution. + + + align:start position:0% +the particular solution. +If we follow these steps, we find that + + align:start position:0% +If we follow these steps, we find that + + + align:start position:0% +If we follow these steps, we find that +it's the real part of the right hand + + align:start position:0% +it's the real part of the right hand + + + align:start position:0% +it's the real part of the right hand +side complexified which is f e to the i + + align:start position:0% +side complexified which is f e to the i + + + align:start position:0% +side complexified which is f e to the i +omega + + align:start position:0% +omega + + + align:start position:0% +omega +t divided by the characteristic polomial + + align:start position:0% +t divided by the characteristic polomial + + + align:start position:0% +t divided by the characteristic polomial +evaluated at i + + align:start position:0% + + + + align:start position:0% + +omega. And in this case the + + align:start position:0% +omega. And in this case the + + + align:start position:0% +omega. And in this case the +characteristic + + align:start position:0% + + + + align:start position:0% + +polomial p of + + align:start position:0% + + + + align:start position:0% + +s is s + + align:start position:0% +s is s + + + align:start position:0% +s is s +2 + s + 4. + + align:start position:0% + + + + align:start position:0% + +P of I + + align:start position:0% +P of I + + + align:start position:0% +P of I +omega is then 4 - omega^ + + align:start position:0% +omega is then 4 - omega^ + + + align:start position:0% +omega is then 4 - omega^ +2 plus I + + align:start position:0% + + + + align:start position:0% + +omega. And when we put the pieces + + align:start position:0% +omega. And when we put the pieces + + + align:start position:0% +omega. And when we put the pieces +together, we end up with a particular + + align:start position:0% +together, we end up with a particular + + + align:start position:0% +together, we end up with a particular +solution which looks like the real + + align:start position:0% + + + + align:start position:0% + +part of 1 4 - omega^ 2 plus i + + align:start position:0% +part of 1 4 - omega^ 2 plus i + + + align:start position:0% +part of 1 4 - omega^ 2 plus i +omega f + + align:start position:0% +omega f + + + align:start position:0% +omega f +upstairs e i omega + + align:start position:0% + + + + align:start position:0% + +t. Okay, so we're asked to uh compute + + align:start position:0% +t. Okay, so we're asked to uh compute + + + align:start position:0% +t. Okay, so we're asked to uh compute +the amplitude response formula or the + + align:start position:0% +the amplitude response formula or the + + + align:start position:0% +the amplitude response formula or the +amplitude response graph. And if we take + + align:start position:0% +amplitude response graph. And if we take + + + align:start position:0% +amplitude response graph. And if we take +a look at this uh we see that the + + align:start position:0% +a look at this uh we see that the + + + align:start position:0% +a look at this uh we see that the +denominator here is really just a + + align:start position:0% +denominator here is really just a + + + align:start position:0% +denominator here is really just a +complex number. So we can convert it + + align:start position:0% +complex number. So we can convert it + + + align:start position:0% +complex number. So we can convert it +into the form of r e to the i + + align:start position:0% + + + + align:start position:0% + +fi. Now the amplitude response is + + align:start position:0% +fi. Now the amplitude response is + + + align:start position:0% +fi. Now the amplitude response is +defined as the uh ratio of the output + + align:start position:0% +defined as the uh ratio of the output + + + align:start position:0% +defined as the uh ratio of the output +divided by the input. And so the output + + align:start position:0% + + + + align:start position:0% + +amplitude is going to be the magnitude + + align:start position:0% +amplitude is going to be the magnitude + + + align:start position:0% +amplitude is going to be the magnitude +of this complex number. + + align:start position:0% + + + + align:start position:0% + +So as a result the amplitude + + align:start position:0% +So as a result the amplitude + + + align:start position:0% +So as a result the amplitude +response it's just the magnitude of one + + align:start position:0% +response it's just the magnitude of one + + + align:start position:0% +response it's just the magnitude of one +over the characteristic polomial + + align:start position:0% +over the characteristic polomial + + + align:start position:0% +over the characteristic polomial +evaluated at I omega. This is also + + align:start position:0% +evaluated at I omega. This is also + + + align:start position:0% +evaluated at I omega. This is also +sometimes referred to as the complex + + align:start position:0% +sometimes referred to as the complex + + + align:start position:0% +sometimes referred to as the complex +gain. Moreover, this term right here + + align:start position:0% +gain. Moreover, this term right here + + + align:start position:0% +gain. Moreover, this term right here +contains two pieces of information. Not + + align:start position:0% +contains two pieces of information. Not + + + align:start position:0% +contains two pieces of information. Not +only does it contain the amplitude + + align:start position:0% +only does it contain the amplitude + + + align:start position:0% +only does it contain the amplitude +response, but it also contains uh the + + align:start position:0% +response, but it also contains uh the + + + align:start position:0% +response, but it also contains uh the +phase information. + + align:start position:0% +phase information. + + + align:start position:0% +phase information. +When we take the absolute value, we're + + align:start position:0% +When we take the absolute value, we're + + + align:start position:0% +When we take the absolute value, we're +throwing out the phase information and + + align:start position:0% +throwing out the phase information and + + + align:start position:0% +throwing out the phase information and +we're just remembering the amplitude + + align:start position:0% + + + + align:start position:0% + +response. Okay. So, what does this + + align:start position:0% +response. Okay. So, what does this + + + align:start position:0% +response. Okay. So, what does this +amplitude response look like for this + + align:start position:0% +amplitude response look like for this + + + align:start position:0% +amplitude response look like for this +case? + + align:start position:0% + + + + align:start position:0% + +Well, we have 1 over and it's the + + align:start position:0% +Well, we have 1 over and it's the + + + align:start position:0% +Well, we have 1 over and it's the +magnitude of this complex number which + + align:start position:0% +magnitude of this complex number which + + + align:start position:0% +magnitude of this complex number which +is 4 - omega^ 2 plus i omega. + + align:start position:0% +is 4 - omega^ 2 plus i omega. + + + align:start position:0% +is 4 - omega^ 2 plus i omega. +So I just take the real part square it + + align:start position:0% +So I just take the real part square it + + + align:start position:0% +So I just take the real part square it +add it to the imaginary part squared and + + align:start position:0% +add it to the imaginary part squared and + + + align:start position:0% +add it to the imaginary part squared and +square root the whole + + align:start position:0% + + + + align:start position:0% + +quantity. Now there's a question of how + + align:start position:0% +quantity. Now there's a question of how + + + align:start position:0% +quantity. Now there's a question of how +to graph this and we see that it's that + + align:start position:0% +to graph this and we see that it's that + + + align:start position:0% +to graph this and we see that it's that +well first off the square root's an + + align:start position:0% +well first off the square root's an + + + align:start position:0% +well first off the square root's an +increasing function and we see that + + align:start position:0% +increasing function and we see that + + + align:start position:0% +increasing function and we see that +we're one over an increasing function. + + align:start position:0% +we're one over an increasing function. + + + align:start position:0% +we're one over an increasing function. +So there's a trick which is to just look + + align:start position:0% +So there's a trick which is to just look + + + align:start position:0% +So there's a trick which is to just look +first at sketching this this piece which + + align:start position:0% +first at sketching this this piece which + + + align:start position:0% +first at sketching this this piece which +is under the radical sign. And if you if + + align:start position:0% +is under the radical sign. And if you if + + + align:start position:0% +is under the radical sign. And if you if +you look at maximizing trying to + + align:start position:0% +you look at maximizing trying to + + + align:start position:0% +you look at maximizing trying to +maximize this function so finding the + + align:start position:0% +maximize this function so finding the + + + align:start position:0% +maximize this function so finding the +critical points we see that in this case + + align:start position:0% +critical points we see that in this case + + + align:start position:0% +critical points we see that in this case +we have one + + align:start position:0% + + + + align:start position:0% + +maximum + + align:start position:0% +maximum + + + align:start position:0% +maximum +to 4 - omega^ + + align:start position:0% +to 4 - omega^ + + + align:start position:0% +to 4 - omega^ +2 plus omega^ + + align:start position:0% +2 plus omega^ + + + align:start position:0% +2 plus omega^ +2 and this is + + align:start position:0% +2 and this is + + + align:start position:0% +2 and this is +at when omega equals the square root of + + align:start position:0% +at when omega equals the square root of + + + align:start position:0% +at when omega equals the square root of +seven halves. + + align:start position:0% + + + + align:start position:0% + +Sorry, this is a + + align:start position:0% + + + + align:start position:0% + +minimum. Okay. So when I go to sketch + + align:start position:0% +minimum. Okay. So when I go to sketch + + + align:start position:0% +minimum. Okay. So when I go to sketch +this now, you have + + align:start position:0% +this now, you have + + + align:start position:0% +this now, you have +omega, we have the amplitude + + align:start position:0% + + + + align:start position:0% + +response. Okay. Now I'm going to draw in + + align:start position:0% +response. Okay. Now I'm going to draw in + + + align:start position:0% +response. Okay. Now I'm going to draw in +root two or sorry just two from our + + align:start position:0% +root two or sorry just two from our + + + align:start position:0% +root two or sorry just two from our +previous diagram. + + align:start position:0% +previous diagram. + + + align:start position:0% +previous diagram. +Now the square root of 7 halves is just + + align:start position:0% +Now the square root of 7 halves is just + + + align:start position:0% +Now the square root of 7 halves is just +below + + align:start position:0% +below + + + align:start position:0% +below +two. So square<unk> of 7 + + align:start position:0% + + + + align:start position:0% + +halves. So we end up with a maximum at 7 + + align:start position:0% +halves. So we end up with a maximum at 7 + + + align:start position:0% +halves. So we end up with a maximum at 7 +halves and then a decay to + + align:start position:0% +halves and then a decay to + + + align:start position:0% +halves and then a decay to +infinity. And again this is going to + + align:start position:0% +infinity. And again this is going to + + + align:start position:0% +infinity. And again this is going to +be 1/4 when omega is + + align:start position:0% +be 1/4 when omega is + + + align:start position:0% +be 1/4 when omega is +zero. Okay. So this is the + + align:start position:0% +zero. Okay. So this is the + + + align:start position:0% +zero. Okay. So this is the +peak amplitude response. So note that in + + align:start position:0% +peak amplitude response. So note that in + + + align:start position:0% +peak amplitude response. So note that in +this case by adding damping what we've + + align:start position:0% +this case by adding damping what we've + + + align:start position:0% +this case by adding damping what we've +done is we've uh we no longer have an + + align:start position:0% +done is we've uh we no longer have an + + + align:start position:0% +done is we've uh we no longer have an +asmtote at omegaals 2 but we now have a + + align:start position:0% +asmtote at omegaals 2 but we now have a + + + align:start position:0% +asmtote at omegaals 2 but we now have a +finite amplitude which occurs at omega + + align:start position:0% +finite amplitude which occurs at omega + + + align:start position:0% +finite amplitude which occurs at omega +omega equals the<unk> of 7 + + align:start position:0% +omega equals the<unk> of 7 + + + align:start position:0% +omega equals the<unk> of 7 +halves. Okay. So I'm just going to clean + + align:start position:0% +halves. Okay. So I'm just going to clean + + + align:start position:0% +halves. Okay. So I'm just going to clean +up the board and I'll be back with part + + align:start position:0% +up the board and I'll be back with part + + + align:start position:0% +up the board and I'll be back with part +C in a second. + + align:start position:0% +C in a second. + + + align:start position:0% +C in a second. +Uh for part a we uh have a resonance + + align:start position:0% +Uh for part a we uh have a resonance + + + align:start position:0% +Uh for part a we uh have a resonance +response or sorry an amplitude response + + align:start position:0% +response or sorry an amplitude response + + + align:start position:0% +response or sorry an amplitude response +diagram which looks like a tent function + + align:start position:0% +diagram which looks like a tent function + + + align:start position:0% +diagram which looks like a tent function +and at two omega equals 2 we have a + + align:start position:0% +and at two omega equals 2 we have a + + + align:start position:0% +and at two omega equals 2 we have a +resonance. So the amplitude response + + align:start position:0% +resonance. So the amplitude response + + + align:start position:0% +resonance. So the amplitude response +diverges just like to point out I made a + + align:start position:0% +diverges just like to point out I made a + + + align:start position:0% +diverges just like to point out I made a +a small error before I forgot to include + + align:start position:0% +a small error before I forgot to include + + + align:start position:0% +a small error before I forgot to include +absolute values uh on the denominator + + align:start position:0% +absolute values uh on the denominator + + + align:start position:0% +absolute values uh on the denominator +here. The amplitude response function + + align:start position:0% +here. The amplitude response function + + + align:start position:0% +here. The amplitude response function +it's always a positive quantity. we + + align:start position:0% +it's always a positive quantity. we + + + align:start position:0% +it's always a positive quantity. we +always throw out uh any phase + + align:start position:0% +always throw out uh any phase + + + align:start position:0% +always throw out uh any phase +information and uh leave that uh for the + + align:start position:0% +information and uh leave that uh for the + + + align:start position:0% +information and uh leave that uh for the +for the phase and um + + align:start position:0% +for the phase and um + + + align:start position:0% +for the phase and um +uh in the description of the response of + + align:start position:0% +uh in the description of the response of + + + align:start position:0% +uh in the description of the response of +a linear + + align:start position:0% +a linear + + + align:start position:0% +a linear +system. So the amplitude response is + + align:start position:0% +system. So the amplitude response is + + + align:start position:0% +system. So the amplitude response is +always positive. Uh for part B we uh we + + align:start position:0% +always positive. Uh for part B we uh we + + + align:start position:0% +always positive. Uh for part B we uh we +added dampening to the system and we see + + align:start position:0% +added dampening to the system and we see + + + align:start position:0% +added dampening to the system and we see +that there's actually a peak point which + + align:start position:0% +that there's actually a peak point which + + + align:start position:0% +that there's actually a peak point which +is at the square root of seven + + align:start position:0% + + + + align:start position:0% + +halves and uh the amplitude response is + + align:start position:0% +halves and uh the amplitude response is + + + align:start position:0% +halves and uh the amplitude response is +bounded at this point but it achieves a + + align:start position:0% +bounded at this point but it achieves a + + + align:start position:0% +bounded at this point but it achieves a +maximum and then again it decays to + + align:start position:0% +maximum and then again it decays to + + + align:start position:0% +maximum and then again it decays to +infinity. So I'd like now uh to take a + + align:start position:0% +infinity. So I'd like now uh to take a + + + align:start position:0% +infinity. So I'd like now uh to take a +look at part C and in part C we have the + + align:start position:0% +look at part C and in part C we have the + + + align:start position:0% +look at part C and in part C we have the +differential equation x dot dot plus 6x + + align:start position:0% +differential equation x dot dot plus 6x + + + align:start position:0% +differential equation x dot dot plus 6x +dot + + align:start position:0% +dot + + + align:start position:0% +dot ++ + + align:start position:0% ++ + + + align:start position:0% ++ +4x = + + align:start position:0% +4x = + + + align:start position:0% +4x = +f cosine omega + + align:start position:0% +f cosine omega + + + align:start position:0% +f cosine omega +t. And again, the amplitude + + align:start position:0% + + + + align:start position:0% + +response is going to equal 1 + + align:start position:0% +response is going to equal 1 + + + align:start position:0% +response is going to equal 1 +over the absolute value of p of i + + align:start position:0% +over the absolute value of p of i + + + align:start position:0% +over the absolute value of p of i +omega. And in this case, p of i omega is + + align:start position:0% +omega. And in this case, p of i omega is + + + align:start position:0% +omega. And in this case, p of i omega is +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +1 over well we still have the 4 - omega^ + + align:start position:0% +1 over well we still have the 4 - omega^ + + + align:start position:0% +1 over well we still have the 4 - omega^ + + align:start position:0% + + + + align:start position:0% + +term instead of x dot we now have six x + + align:start position:0% +term instead of x dot we now have six x + + + align:start position:0% +term instead of x dot we now have six x +dot which gives us 6 i + + align:start position:0% +dot which gives us 6 i + + + align:start position:0% +dot which gives us 6 i +omega and then again we want to take the + + align:start position:0% +omega and then again we want to take the + + + align:start position:0% +omega and then again we want to take the +absolute value of this complex + + align:start position:0% +absolute value of this complex + + + align:start position:0% +absolute value of this complex +number and when we take the absolute + + align:start position:0% +number and when we take the absolute + + + align:start position:0% +number and when we take the absolute +value we just get the sum of the the + + align:start position:0% +value we just get the sum of the the + + + align:start position:0% +value we just get the sum of the the +real part + + align:start position:0% + + + + align:start position:0% + +squared plus the sum of the imaginary + + align:start position:0% +squared plus the sum of the imaginary + + + align:start position:0% +squared plus the sum of the imaginary +part squared which in this case is going + + align:start position:0% +part squared which in this case is going + + + align:start position:0% +part squared which in this case is going +to be 36 omega^ 2 the whole quantity is + + align:start position:0% +to be 36 omega^ 2 the whole quantity is + + + align:start position:0% +to be 36 omega^ 2 the whole quantity is +square rooted and then we have 1 over + + align:start position:0% +square rooted and then we have 1 over + + + align:start position:0% +square rooted and then we have 1 over +this + + align:start position:0% + + + + align:start position:0% + +value. So now if we'd like to plot this + + align:start position:0% +value. So now if we'd like to plot this + + + align:start position:0% +value. So now if we'd like to plot this +this function we can still do the same + + align:start position:0% +this function we can still do the same + + + align:start position:0% +this function we can still do the same +trick and try to maximize or find the + + align:start position:0% +trick and try to maximize or find the + + + align:start position:0% +trick and try to maximize or find the +critical points of the denominator under + + align:start position:0% +critical points of the denominator under + + + align:start position:0% +critical points of the denominator under +the radical and if we did this in this + + align:start position:0% +the radical and if we did this in this + + + align:start position:0% +the radical and if we did this in this +case we would find that the only + + align:start position:0% +case we would find that the only + + + align:start position:0% +case we would find that the only +critical point is when omega is equal to + + align:start position:0% +critical point is when omega is equal to + + + align:start position:0% +critical point is when omega is equal to +zero. Uh secondly, if we look at omega + + align:start position:0% +zero. Uh secondly, if we look at omega + + + align:start position:0% +zero. Uh secondly, if we look at omega +going to infinity, we see that the + + align:start position:0% +going to infinity, we see that the + + + align:start position:0% +going to infinity, we see that the +denominator goes to infinity. So this + + align:start position:0% +denominator goes to infinity. So this + + + align:start position:0% +denominator goes to infinity. So this +whole quantity must go to + + align:start position:0% +whole quantity must go to + + + align:start position:0% +whole quantity must go to +zero. So if I were to go back + + align:start position:0% +zero. So if I were to go back + + + align:start position:0% +zero. So if I were to go back +here to the amplitude response for part + + align:start position:0% +here to the amplitude response for part + + + align:start position:0% +here to the amplitude response for part +C again, when omega is equal to zero, + + align:start position:0% +C again, when omega is equal to zero, + + + align:start position:0% +C again, when omega is equal to zero, +it's going to start off at + + align:start position:0% +it's going to start off at + + + align:start position:0% +it's going to start off at +1/4. I've just argued that it goes to + + align:start position:0% +1/4. I've just argued that it goes to + + + align:start position:0% +1/4. I've just argued that it goes to +zero as omega goes to infinity. And + + align:start position:0% +zero as omega goes to infinity. And + + + align:start position:0% +zero as omega goes to infinity. And +since there are no critical points, we + + align:start position:0% +since there are no critical points, we + + + align:start position:0% +since there are no critical points, we +must smoothly + + align:start position:0% +must smoothly + + + align:start position:0% +must smoothly +paste the function between the two. And + + align:start position:0% +paste the function between the two. And + + + align:start position:0% +paste the function between the two. And +in fact, it's always + + align:start position:0% +in fact, it's always + + + align:start position:0% +in fact, it's always +decreasing. So the amplitude response uh + + align:start position:0% +decreasing. So the amplitude response uh + + + align:start position:0% +decreasing. So the amplitude response uh +in this case is just a decreasing + + align:start position:0% +in this case is just a decreasing + + + align:start position:0% +in this case is just a decreasing +function. Okay. So this concludes part C + + align:start position:0% +function. Okay. So this concludes part C + + + align:start position:0% +function. Okay. So this concludes part C +and now I'll take a look at part D. + + align:start position:0% +and now I'll take a look at part D. + + + align:start position:0% +and now I'll take a look at part D. +Discuss the resonance for each system. + + align:start position:0% +Discuss the resonance for each system. + + + align:start position:0% +Discuss the resonance for each system. +So in part a we had no + + align:start position:0% +So in part a we had no + + + align:start position:0% +So in part a we had no +damping and we saw that there was a + + align:start position:0% +damping and we saw that there was a + + + align:start position:0% +damping and we saw that there was a +resonance at omega equals 2 and uh the + + align:start position:0% +resonance at omega equals 2 and uh the + + + align:start position:0% +resonance at omega equals 2 and uh the +resonance manifested itself uh in the + + align:start position:0% +resonance manifested itself uh in the + + + align:start position:0% +resonance manifested itself uh in the +amplitude response graph with a pole or + + align:start position:0% +amplitude response graph with a pole or + + + align:start position:0% +amplitude response graph with a pole or +a a divergent asmtote at omega is equal + + align:start position:0% +a a divergent asmtote at omega is equal + + + align:start position:0% +a a divergent asmtote at omega is equal +to two. So as as you drive the system + + align:start position:0% +to two. So as as you drive the system + + + align:start position:0% +to two. So as as you drive the system +close to omegaals 2 the amplitude of the + + align:start position:0% +close to omegaals 2 the amplitude of the + + + align:start position:0% +close to omegaals 2 the amplitude of the +system starts to + + align:start position:0% +system starts to + + + align:start position:0% +system starts to +diverge. In case two uh we introduce + + align:start position:0% +diverge. In case two uh we introduce + + + align:start position:0% +diverge. In case two uh we introduce +damping into the system. So we still + + align:start position:0% +damping into the system. So we still + + + align:start position:0% +damping into the system. So we still +have a very large amplitude response at + + align:start position:0% +have a very large amplitude response at + + + align:start position:0% +have a very large amplitude response at +omega equals the<unk> of 7 halves. + + align:start position:0% +omega equals the<unk> of 7 halves. + + + align:start position:0% +omega equals the<unk> of 7 halves. +However, it's no longer infinite + + align:start position:0% +However, it's no longer infinite + + + align:start position:0% +However, it's no longer infinite +infinite. Uh and then lastly uh when we + + align:start position:0% +infinite. Uh and then lastly uh when we + + + align:start position:0% +infinite. Uh and then lastly uh when we +increase damping even further uh so we + + align:start position:0% +increase damping even further uh so we + + + align:start position:0% +increase damping even further uh so we +had the six x dot term the uh the + + align:start position:0% +had the six x dot term the uh the + + + align:start position:0% +had the six x dot term the uh the +presence of a peak uh disappeared and in + + align:start position:0% +presence of a peak uh disappeared and in + + + align:start position:0% +presence of a peak uh disappeared and in +fact the amplitude response just + + align:start position:0% +fact the amplitude response just + + + align:start position:0% +fact the amplitude response just +monotonically decayed from 1/2 to + + align:start position:0% +monotonically decayed from 1/2 to + + + align:start position:0% +monotonically decayed from 1/2 to +infinity. So it just constantly uh + + align:start position:0% +infinity. So it just constantly uh + + + align:start position:0% +infinity. So it just constantly uh +decreased to + + align:start position:0% +decreased to + + + align:start position:0% +decreased to +zero. So I'd just like to conclude there + + align:start position:0% +zero. So I'd just like to conclude there + + + align:start position:0% +zero. So I'd just like to conclude there +and I'll see you next time. \ No newline at end of file diff --git a/s83SihcFfYo.txt b/s83SihcFfYo.txt new file mode 100644 index 0000000000000000000000000000000000000000..3ac62abf5b0e8e39fc22c6fff4b2b99bb84e2354 --- /dev/null +++ b/s83SihcFfYo.txt @@ -0,0 +1,2659 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help +MIT OpenCourseWare + +continue to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: My first +question is, do you + +have any questions about +the last class, about + +the introduction, about the +course overview, the syllabus, + +any requirements of the +course, formalities? + +It should be pretty clear. + +So today, we start +from first principles. + +I want to give you a +rigorous derivation of what + +this course is based, +namely, the Hamiltonian + +to describe the interaction +between atoms and light. + +I mentioned to you last +week that atomic physics can + +be defined about +everything that is + +interesting about the building +blocks of nature, atoms + +interacting with light +electromagnetic fields, Coulomb + +fields, and today, we'll talk +about the first principle, + +Hamiltonian. + +The reference for +that, and I'm closely + +following that derivation, +is the book Atom-Photon + +Interaction, the green book +by Cohen-Tannoudji, Grynberg, + +and others, and it's +taken from the appendix. + +And if you flip +through the appendix, + +you will find out that there +are about 100 equations. + +Today, we'll discuss +every single of them. + +However, the good +news is the result + +in the end is simple +and intuitive. + +In the end, we +have what we want, + +that the electromagnetic field +couples different energy levels, + +and then we can play +around with quantum case, + +with laser cooling. + +All we need is a +coupling matrix element. + +And for most of the +course, I will not even + +elaborate what this +matrix element is about. + +But here, we derive it +from first principles. + +The result we will +use most often + +is actually the electric +dipole approximation, + +which I'm sure you have +already seen many, many times. + +So in that sense, I sometimes +have second thoughts. + +Should I dedicate +a whole lecture + +to derive something +you know already? + +On the other hand, this is sort +of the meat of atomic physics, + +and I want to go +as deep as possible + +into it, that +whenever you wonder + +what form of other +interactions exist, + +you have a reference +to look it up. + +And so to some extent, +I want to also encourage + +you to read more about the +fundamental nature of how light + +and atoms interact. + +I will give you another +reference a little bit later on. + +But as a motivation, +I want to tell you + +what I learned when I +prepared this lecture, + +and I hope that there +is something that you + +will learn from this treatment. + +One is a rigorous +separation of local fields + +from radiation fields. + +Let me just write it +down, rigorous separation + +of local Coulomb fields +from radiation fields. + +So to clearly separate the +terms in the Hamiltonian, + +let me explain that. + +When we introduce +electromagnetic fields + +into our world, we would +say we introduce them + +by saying particles have charge. + +But some parts of the +charged particle physics + +is something we want to include +in the description of atoms, + +and that's the Coulomb +field of protons. + +The structure of atoms +is electromagnetic, + +but when we now introduce +electromagnetic field + +as a new degree of freedom-- + +photons can be admitted, +absorbed, and such-- + +we only want to talk about +the electric field which + +belongs to the photons and +not the electric field which + +belongs to the atoms. + +And you may wonder, can you +distinguish between two kinds + +of electric fields? + +The answer is yes, and I want to +show you how mathematically you + +distinguish when you introduce +electromagnetic fields + +between the fields which stay +with the atom, which don't have + +an extra degree of +freedom, and if you + +do canonical quantization, +they don't enter + +as an extra variable, and the +fields which are the photons, + +and these are the extra +objects we have to consider. + +What is also related is when +you do second quantization, + +if you wanted, I could quantize +electromagnetic field for you + +in five minutes. + +Just say it's +harmonic oscillator. + +You're familiar with +harmonic oscillator, + +and let's just do it. + +Yes, this is correct, and I will +remind you of that a little bit + +later, but there is +one non-trivial aspect + +if you want to do quantization +of a field theory, + +you have to make sure that +before you quantize it, + +you know which degrees of +freedom are really independent. + +So the question is, how +many independent fields does + +the electromagnetic field have? + +The naive answer is three +electric field components, + +three magnetic field +components, that makes six. + +But of course they're +not independent, + +and we will discuss that. + +So we'll spend some time +in the identification + +of truly independent field +components, or degrees + +of freedom of the +electromagnetic field. + +So all that is an excursion +into classical physics + +because it is just reformulating +classical electrodynamics + +to be ready for quantization. + +Actually, all the work is +done to discuss and derive + +the appropriate +classical description. + +That means to eliminate +all redundant variables, + +and then at the end, have +variables which, yes, + +will look like a +harmonic oscillator. + +And once we have reduced it +to degrees of freedom which + +look like a harmonic oscillator, +it is very straightforward + +to do the field quantization +following the recipe + +of the harmonic oscillator. + +There's one more highlight, +if I want to say so, + +and this is a truly +rigorous derivation + +of the electric +dipole approximation. + +In most quantum +mechanics textbooks, + +you do a dipole +approximation and you wind up + +with the electric dipole +Hamiltonian, which + +I have already put up +there, but you do actually + +unnecessary +approximations in terms + +of neglecting an a squared +term, and there are often + +confusing discussions what +happens with the a squared term. + +I want to show you a +more rigorous deviation + +of the electric dipole +approximation, which is + +including the quadratic term. + +That actually means-- that's +the take home message-- + +the electric dipole +approximation + +is actually better than many +of you have thought so far. + +Since I don't want to +write out 100 equations, + +I copied them and summarized +them out of the book. + +You'll find them all, +as I mentioned before, + +in the appendix of +Atom-Photon Interaction. + +But I sort of want +to walk you through. + +What I'm aiming at is that you +have sort of a complete overview + +how is everything +coming together, + +and if it's just mathematical, +well, mathematics + +is always exact. + +I can go faster, +but I really want + +to highlight here every +single physical concept + +and approximation we are doing. + +When we start out with +Maxwell's equations, + +we have actually six components +of the electromagnetic field, + +and we will see in a moment +that this is redundant. + +What will turn out to be +very important to separate + +the local fields from +the radiation field + +is a Fourier transformation, +so we introduce an expansion + +into plain waves. + +And what then +happens, of course, + +is the derivative operator +becomes the k vector. + +So therefore, when you +have Maxwell's equations + +with the curl, del cross +B, it turns into k cross + +B. This is now important because +we have now separate equations + +for the component of the +electric and magnetic field, + +which is parallel to +k, projected onto k, + +and of course, the cross product +takes out the component which + +is perpendicular to k. + +So that's something +which is sort of nice, + +that the Fourier transform +it allows us to separate + +the fields into +longitudinal fields, where + +the vector of the +Fourier component + +is parallel to the k vector, +and into transverse components. + +AUDIENCE: What's the difference +between the curly vectors + +and the non-curly vectors? + +PROFESSOR: The difference +between curly and non-curly + +vector is one is a +Fourier transform, + +the other one is other +spatial components. + +I have to actually +say the book API + +tries to be super accurate +in choosing symbols. + +Claude Cohen-Tannoudji +is really a master + +of elegance and +perfection, so they + +don't want to use the same +symbol for a spatial component + +and for the Fourier component. + +On the other hand, I have +to tell you one thing. + +For the next hour, use a +little bit your intuition. + +If you see e, it +means electric field. + +Whether it is curly, +whether it's italic, + +whether it's bold face, +don't let those differences + +clutter your view. + +So I would say don't +ask me too often, + +what exactly does it +mean now because you have + +gone from curly to non-curly? + +It is explained in the appendix. + +I will tell you everything +which is necessary, + +but these are +subtleties which are + +more to present the mathematics +in a more rigorous way. + +We have the spatial +Fourier components, + +and as I mentioned, what you can +do only because of the Fourier + +transform, you have +now the distinction, + +a rigorous separation +between the parallel + +and the longitudinal fields. + +So of course, you +can also now get back + +what is the longitudinal +field, not in Fourier space + +but in position +space, by just taking + +the longitudinal or transverse +components of the Fourier + +transform and +transforming them back. + +Why I'm elaborating +on that is we + +will see in the next few minutes +that the transverse field + +is the field which propagates. + +The longitudinal field +is the Coulomb field. + +It belongs to the +atoms and will not + +become a new degree of freedom. + +And we see that immediately +in the next equations. + +When we look now at +Maxwell's equations, + +we find that the transverse and +longitudinal fields decouple. + +We have two kinds of equations +which are completely decoupled. + +The longitudinal electric field +is the Coulomb field associated + +with a charge density, whereas +the transverse fields are + +creating themselves, +and this is radiation, + +how the electric and magnetic +fields create themselves + +as they propagate. + +Now, the fact that the +parallel electric field + +can be expressed by +the charge density, + +or it's expressed by the +momentary position of charges, + +and this means immediately that +the longitudinal field is not + +an independent variable or +an extra degree of freedom. + +Canonical, of course, +with how we describe + +particles by their position, +and here you see explicitly + +that the longitudinal +field which + +we defined the way we did it, +that this part of the field + +only depends on the momentarily +electric field, the Coulomb + +field associated +with the charges. + +The next thing, of course, is +to define the vector potential + +and the scalar potential. + +By using the standard +substitution, + +we can now express electric +and magnetic fields + +by a scalar potential and +by a vector potential. + +We continue to +have the separation + +between longitudinal +and transverse fields, + +namely the transverse +electromagnetic fields + +depend only on the +transverse component + +of the vector potential. + +And the transverse component +is gauge invariant. + +In other words, you know +there are different gauges we + +can consider when we introduce +electromagnetic potentials, + +but the choice of gauge does +not affect the transverse vector + +potential. + +Now we want to pick our gauge +and repeat the gauge which + +is most convenient. + +This is typically, for low +energy quantum physics, + +for describing atoms and +radiation, the Coulomb gauge. + +So we have the freedom of +gauge, and the Coulomb gauge + +is written by the divergence +of the vector potential is 0. + +If you now think about +Fourier transform, + +this means k dot the +Fourier component is 0, + +and that means the vector +potential does not have + +any longitudinal component. + +So with that, we have +now reduced equations + +for six variables, three +electric fields, three + +magnetic field components. + +By introducing vector and scalar +potential, you go to four. + +We've eliminated one more +with the Coulomb gauge, + +so we have three. + +The scalar potential is +the Coulomb potential. + +It's not an extra +degree of freedom. + +And what is left are +the two field components + +of the transverse +vector potential. + +And these are now, as we will +see, the independent variables + +of the radiation field. + +So in other words, when we talk +about the electromagnetic field + +in the remainder of +the course, the part + +of the electromagnetic +field we are interested in + +are the fields generated by the +transverse vector potential. + +Now, what is next is to +go into normal modes. + +The reason is that +we want to identify + +each normal mode of the +electromagnetic field + +as an independent +harmonic oscillator. + +Now, I'm showing +you those equations, + +but you sort of have to sit +back because now there will be + +alphas, a's, lower +a's, upper A's. + +They all mean pretty +much the same. + +In one case, you are +normalized, maybe something + +has to be factored out or not. + +The derivation in +the appendix of API + +is exactly [INAUDIBLE] +distinction, + +but let me just give +you a flyover here. + +And that is we are now taking +the transverse components + +from the electromagnetic field, +and we define new parameters, + +which are the normal modes. + +What we actually want +to see in a moment + +is that those normal +mode variables + +are harmonic oscillators. + +Those normal modes +can be defined + +by the original field, +which are transverse, + +but since we have expressed +the transverse field + +by the transverse +vector potential, + +they also simply +can be expressed + +by the transverse +vector potential. + +So to remind you, we've +done a Fourier transform + +in the spatial +coordinate, but not + +yet in the temporal coordinate. + +What we obtain +now is an equation + +of motion for the +normal mode variables. + +And here, I have reminded you +that the transverse vector + +potential, how it can be +expressed by the normal mode + +variables. + +In other words, yes, it looks +complicated and a little bit + +messy, but it's classical +physics, and all we have done + +is introduce normal modes in a +just more complicated notation, + +as you may have seen it in +803 or some other course + +where for the first +time you talked + +about normal modes of a +pendulum or a chain of springs. + +So we have identified normal +modes by the equation above, + +and then it's a +mathematical identity + +that our radiation field, our +transverse vector potential, + +can simply be expended +into normal modes. + +So the equation of motion +for the transverse fields + +involves of course, the +transverse vector potential. + +I should have scrolled back. + +Here we have our equations +for the transverse fields. + +This is what we +want to describe, + +and if we express everything in +terms of the vector potential, + +then we have an equation which +involves the transverse vector + +potential, but in +addition, because it's + +a differential equation, the +first and second derivative. + +That means that if you have +a second order differential + +equation, which is +the full description + +of the electromagnetic +field, then + +you know that the solution +of the second order equation + +needs as an initial +condition the field itself + +and the first derivative. + +Therefore, our +classical fields are + +determined by a perpendicular +and its derivative + +at the initial time. + +So we need a and we need a +dot, and they are coupled, + +but what we are +doing right now is-- + +and this is the idea +behind the normal modes-- + +the normal modes coordinates +combine a and a dot. + +It's the same when you +have a harmonic oscillator + +and you want to introduce +coordinates for the normal mode, + +they are a combination +of position and momentum, + +and then they are decoupled. + +But position and momentum +always couple or oscillate + +back and forth, and +the same happens here + +between a and a dot, and +the normal mode coordinates + +are the linear combination. + +In other words, the +equation of motion + +coupled source and +normal mode means + +that we have introduced +he decoupled normal modes. + +And whenever, in classical +physics, we have normal modes, + +normal modes means that time +dependence is e to the i omega + +t, then we have distilled the +problem of coupled components + +to decoupled +harmonic oscillators. + +So at this point, each mode +acts as an independent harmonic + +oscillator. + +So what I wanted to show you +here is clearly, as a flyover, + +and as an appetizer to +read more in the book, + +that we can start with +the electromagnetic field + +components. + +We haven't just assumed +we have now empty space + +and only [INAUDIBLE] radiation. + +We have rigorously separated +the electromagnetic field + +in what belongs to the atoms +and what belongs to radiation, + +and the trick was a +spatial Fourier component. + +At that moment, we +had a description + +in terms of the transverse +vector potential, + +and by using purely +classical physics, + +by combining the vector +potential and its derivative, + +we found normal modes, and they +are now completely independent + +harmonic oscillators. + +This approach, and I wanted +to show that to you, involved + +a lot of notation-- + +a's, little alphas, +normal modes, and such. + +Let me just simply show you +another much, much shorter + +pathway how you see that +everything looks and smells + +like a harmonic +oscillator, and then we'll + +do the last step, which +is rather straightforward. + +We quantize the +electromagnetic field. + +I could quantize it +right now, but we + +should take a short break from +the appendix in Atom-Photon + +Interaction and do a +more intuitive shortcut + +to the same physics. + +Any questions at this point? + +If you feel it's +confusing, remind yourself + +this is just classical physics. + +We are just rewriting Maxwell's +equations in new variables. + +So what we do now is, +as I said, let's repeat + +some of this deviation +by focusing on energy. + +If you write down energy for +our systems of atoms, photons, + +and Coulomb fields, we +have particles alpha + +with mass m alpha +and velocity v alpha. + +This is our kinetic energy. + +And then we use the +well known expression + +for the electromagnetic +field, which + +is the spatial integral over +E squared plus B squared. + +This integral over the +electromagnetic field energy + +density can actually +be nicely separated + +into integral over the +longitudinal field which + +we have introduced and +a second integral, which + +involves the transverse field. + +Of course, the magnetic +field is only transverse + +because the divergence of +the magnetic field is 0, + +and that means the magnetic +field does not have + +any longitudinal component. + +So this part here, as +we actually have shown, + +is given by simply the +Coulomb energy where + +we have charge +density at position r + +and r prime interacting with +the Coulomb interaction. + +Eventually, if you want +to treat that further, + +this Coulomb energy should be +split into some divergent self + +energy, which is the energy +of the electron interacting + +with itself, and +people know how to deal + +with that, and the +interaction energy, + +for example, between the +proton and the electron, + +which is responsible for +the atomic structure. + +So in other words, we know +how to deal with that. + +This actually becomes +atomic structure. + +This is in contrast +to this part here, + +which is the classical energy +of the radiation field, which + +is sort of the transverse +part of the energy. + +To describe now +radiation, we have + +to focus on this +transverse part, + +and we are now expressing the +transverse part by the vector + +potential and its derivatives. + +So we introduce the vector +potential as before, + +and I don't want to go +through the re-derivation. + +I just want to show you +how the total energy now + +appears in terms of +the vector potential. + +And what we need for that +is, of course, the vector + +potential and its derivative. + +The vector potential +depends on polarization, + +depends on the +Fourier component, + +and we call this derivative +of the vector potential + +the conjugate momentum. + +So now focusing on +energy, we, of course, + +reduce everything as before +to the vector potential + +and its derivative. + +So we sum over polarization. + +We integrate over all +Fourier components. + +and the integral involves +now the vector potential, + +the square of it, or in complex +notation, the complex conjugate, + +depends on polarization. + +We have c squared k square. + +This part, of course, comes +from the magnetic field, + +which depends on the +vector potential. + +It's a spatial +derivative, the curl, + +and this gives the k +squared, whereas the part + +of the electromagnetic +energy, which + +is related to the electric +field, the electric field + +is a temporal derivative +of the vector potential, + +and therefore, it involves +the temporal derivatives which + +are now the canonical momenta. + +So this equation should +really remind you now-- + +it's an energy equation-- + +of the energy of a harmonic +oscillator because the energy is + +now a sum over all oscillators, +but this is sort of x squared, + +the amplitude of the +oscillator squared, + +this is the potential energy. + +And here we have the derivative +of x, the velocity or momentum, + +and this should remind +you of the kinetic energy + +of a harmonic oscillator. + +In other words, +this should tell you + +that by focusing on the +transverse component + +of the vector potential, it's +about lots of summation-- + +k summation, +polarization summation. + +We in the end find +that each such mode + +is a harmonic oscillator. + +Any questions? + +Let me just show +you now, and it may + +help you to go through +the previous derivation, + +let me know introduce what I +did before, the normal modes, + +and then show you +how the energy looks + +like defined in normal modes. + +So we have these +normal mode variables, + +which are defined as a +superposition of A and A dot. + +And I'm not telling you +here with all the indices + +whether it's the polarization +component, the k component. + +I just want to tell +you the structure. + +The normal mode is a +superposition of A dot and A. + +And with that, the energy +of the electromagnetic field + +can be written-- + +well, we always have to sum +over Fourier components. + +We always have to sum +over the polarization. + +But then we have something +which is very, very simple + +and intuitive. + +It's just the square of alpha +with the correct polarization, + +the pre-factor is +h bar omega over 2. + +It looks like quantum mechanics, +h bar omega times A dagger + +A plus 1/2, but this +is purely classical. + +There is no quantization, +there is no operator. + +We've simply defined +something new, namely alpha + +in terms of the +vector potential. + +In that sense, if you're going +to go back to the derivation, + +the alphas are nothing else +than some elaborate combination + +of the transverse electric +and magnetic field. + +Colin? + +AUDIENCE: Where does +the h bar come in? + +Is that the +coefficient of alpha? + +PROFESSOR: h bar +only enters through + +the constant in the definition +of the normal mode parameter. + +So actually, I have +introduced h bar + +by choosing this parameter +wisely in such a way + +that it connects with +quantum mechanics. + +But it's a completely +arbitrary introduction here. + +I could have said h bar to 1. + +I hope you enjoyed, or at least +did not dislike this excursion + +into classical physics. + +We have now two equations +for describing the energy + +of a harmonic oscillator. + +So both of these equations look +like a harmonic oscillator, + +but if something looks +like a harmonic oscillator, + +it is a harmonic oscillator. + +And I think I should +always remind you + +that so far, everything +has been purely classical. + +And also, let me write down +that h bar enters solely + +through the constant in the +definition of the normal mode + +parameter, alpha. + +If you want to know more about +it, there is a second reference. + +I will actually show you the +cover page in a few moments. + +But there is a second book +by Claude Cohen-Tannoudji + +and collaborators, not +Atom-Photon Interaction, + +but called Photons and Atoms. + +It's a whole book on +rigorously defining QED. + +So a whole book has been +written about the subject + +of this lecture, and on page 27, +you can read more about that. + +So enough of classical physics. + +All we have done so far-- + +I'm sorry for repeating +it, but I think + +I can't repeat it too often with +so many complicated equations + +on the screen-- + +all we have done +so far is we have + +rewritten Maxwell's equations. + +We have rewritten Maxwell's +equations in Fourier space, + +with the vector potential, +eventually with normal modes. + +That's all we have done. + +But now what we are doing is we +do the step in quantum mechanics + +which you have already +seen a few times, + +and this is you have written +equations in such a way + +that they look like +harmonic oscillators, + +and then you postulate that +the classical quantities become + +operators. + +The transverse vector potential +and the conjugate canonical + +momentum fulfill +now commutators, + +and we use those commutators +to define them as operators. + +Now, it looks particularly +easy when we use normal mode + +operators because the +normal mode operators + +after quantization become +our a's and a daggers. + +That was one of the things +I wanted to show you, + +that you can go through +everything introducing + +classical normal modes, +and then the normal modes + +turns into operators, and +now we have all your creation + +and annihilation operators. + +In other words, quantization +cannot be rigorously proven. + +I mean, you cannot prove quantum +theory from first principles. + +You can have a +mathematical framework + +and check it against nature. + +What we have done here is to +formulate the quantum theory. + +At this point, we've +made a postulate + +that we have operators which +fulfill a commutation relation. + +And it is now your +choice if you want + +to formulate postulate +the commutator + +for the transverse +vector potential + +and its conjugate momentum, +or if you immediately + +want to jump at +the normal modes, + +and that would mean you have the +commutator for a and a dagger. + +We are almost done with that. + +We started with the +electromagnetic fields. + +We went through +transverse fields, + +vector potential, normal +modes, now we quantize. + +But now all the equations, all +the substitutions we have made, + +we can go backward. + +Therefore, we can now express +the transverse vector potential, + +the electric and the magnetic +field, by the normal modes, + +or that would mean +in quantum mechanics, + +after quantization, +we can express them + +by the a's and a +daggers, and this + +is how we define the +operator of the electric, + +the magnetic field, and +the vector potential. + +So now, our fully +quantized theory + +has operators, a of a +dagger, or if you want now, + +the first defined operators +of vector potential, electric + +and magnetic field. + +And just to remind you, since +atomic physics is between fields + +and particles, we have exactly +the standard definition + +of the particle operators. + +Each particle is described by +its momentum and its position. + +So with that, we +have our Hamiltonian, + +and a lot of what we +discuss in this course + +are understanding +this Hamiltonian, + +understanding its solution, +understanding what is + +the physics described by that. + +So this Hamiltonian, this +is the kinetic energy. + +The canonical momentum +minus the vector potential + +is the mechanical velocity. + +This is kinetic energy. + +And we have separated the energy +of the electromagnetic field + +into the Coulomb energy, +which is written again here, + +and the radiation field. + +There is now one more term +which we need later on, which + +is this one here. + +And at this point, I would say-- + +I'm just heuristically +adding it by hand-- + +classical we don't have spin, +but our particles have spin, + +and now we need +[INAUDIBLE] coupling, + +how does the spin couple +to the rest of the world? + +Well, the spin, if you +multiply it with the g factor, + +the Bohr magneton has +a magnetic moment, + +and what we simply +add here is mu dot p, + +be the interaction of +the magnetic moment + +with the magnetic field. + +So in that sense, we have +been classical all the way. + +Now at the end we +said, we need the spin. + +Let's put it on by simply +taking an interaction, which + +is mu dot p. + +If you don't like +that because I try + +to be very fundamental today +and go from first principles, + +for electrons, you +can get that by taking + +the non-relativistic unit +of the Dirac equation. + +So if you have +electrons, you can + +start with the Dirac equation +and do the Pauli approximation, + +which is the non-relativistic +limit of the Dirac equation. + +Any questions? + +So these are all the +terms in the Hamiltonian. + +I mentioned, but I +don't want to dwell on, + +that the Coulomb energy has to +be separated into a Coulomb self + +energy and an interaction energy +between the charged particles, + +but all of that becomes just +one term in our Hamiltonian. + +This is the atomic structure. + +When we assume that +atoms have energy levels, + +all the energy is +included in that, + +so we will not discuss any +further the Coulomb energy. + +We will simply assume +we have an atom which + +has certain energy +levels, and that + +includes all the Coulomb terms. + +But we will talk a lot +about the Hamiltonian + +for the radiation field. + +The Hamiltonian for +the radiation field + +can be conveniently +written in a and a dagger, + +but I have a few equations +up there I rigorously + +defined for you operators E and +B in terms of a and a daggers, + +and those two equations +are identical. + +So this looks very quantum, +this looks very classical, + +but if you interpret the +electric and magnetic field + +as operators, we have identical +equations for the Hamiltonian + +of the radiation field. + +What we want to study +are interactions + +between light and atoms, +and of course, this + +comes from the vector potential. + +And in particular, +when we square it out, + +the canonical momentum of the +atoms times the vector potential + +has this cross term, p dot a. + +So let me know just +take this Hamiltonian + +and write it in the way how we +will need it for this course. + +We want to take the Hamiltonian, +and I will often refer to that. + +We want to take the +Hamiltonian and split it + +into three parts, the +atoms, the radiation + +field, and the interaction +between the two. + +The Hamiltonian for the +particles, H subscript P, + +has the momentum +squared, and it has + +the part of the electromagnetic +fields which are longitudinal, + +the energy of which can be +described by a Coulomb integral. + +We have already discussed +the radiation field. + +The radiation field +was nothing else + +than h bar omega, a +dagger a, but the new part + +which we need now is +the interaction term. + +I want to show you +now, or remind you + +by just summarizing the term, +that the interaction part has + +actually three different terms. + +The first one is the cross +term between p and A. + +The second one, when we had +p minus A and squared it, + +is the A squared term. + +And the third one +is the interaction + +of the spin with the magnetic +component of the radiation + +field. + +This is the mu +dot B interaction. + +I don't think it's an +exaggeration when I tell you + +that with those three +equations, you can understand + +all of atomic physics. + +This term here that's +important is second order + +in A, which of +course also means it + +will be very important for +very strong laser palaces, + +but there's more to +be said about it. + +If you're interested +in this subject, + +and I couldn't do +full justice to it, + +you may want to look at +this book from Claude + +Cohen-Tannoudji, Jacques +Dupont-Roc, and Gilbert Grynberg + +about photons and atoms. + +The whole book is +dedicated how to describe + +the interaction of atoms +with electromagnetic fields. + +In this book, they go +through different ways + +of formulating the +electromagnetic field + +classically. + +They use Lagrangian formalism +for the electromagnetic field + +and show the Euler-Lagrange +equation or Maxwell's equation. + +There are lots of +different approaches, + +and also, one can +say what we did + +here, which is the +simplest way of describing + +light-atom interaction, will +work in the Coulomb gauge, which + +is not the gauge you would +choose when you want to describe + +relativistic physics. + +There is the other gauge, +the Lawrence gauge. + +It makes the field quantization +much more difficult, + +but when you ever wondered, +why is the quantization done + +in the way I did, and you think +something I did was arbitrary-- + +why did I pick +the Coulomb gauge? + +Read this book. + +There are hundreds of pages +which explain it to you. + +And I'm not joking here, +it's wonderful reading. + +I got the book just +looked up a few things + +and I almost got hooked on +it and read more and more. + +It's a fascinating story how +deeply people have thought + +about how to describe +this aspect of the course + +and how profound +the thoughts are. + +What this book will emphasize-- + +and this is what +I want to tell you + +in closing about +the quantization + +of the electromagnetic field-- + +is the following. + +We were really working hard +with classical field equations + +to describe the +electromagnetic field + +classically by completely +eliminating redundant variables. + +We started with six components +of the electric and magnetic + +field and reduced it +to two components, + +the two components of the +transverse vector potentials. + +And as those masters +say, as a result, + +the field can be quantized +with a great economy + +in the formalism. + +If you want to have more +symmetric formulations, where + +you don't eliminate the +variables using the Coulomb + +gauge, the problem is +you have variables, + +which are not independent. + +And now I think if +you quantize, you + +have to formulate auxiliary +conditions between the not + +independent operators. + +Aesthetically, it may be +pleasing because the approach is + +more symmetric, but +mathematically, it's + +much more involved. + +Anyway, if you're +interested, this book + +has a wonderful discussion +on the different ways how + +you can approach +interactions of atoms + +with electromagnetic fields. + +I hope nobody has a +question about that, + +because I'm not able to explain +to you much more than that. + +Anyway, questions? + +We have derived from first +principles the Hamiltonian, + +and the result is +something many of you + +are already familiar with. + +Let me now spend the +next 10 or 15 minutes + +on what is called the +dipole approximation + +and the dipole Hamiltonian. + +We are talking know about +one further expansion + +of our expressions, and this +is the multipole expansion. + +Let me first give you the +simple derivation, which + +you may have seen, but +then you can appreciate + +the rigorous derivation. + +Either directly or through +the vector potential, + +we have formulated +our theory in terms + +of the electric and magnetic +field as a function of position. + +But what we now want to +exploit is that atoms are tiny, + +and usually, the electric +or magnetic field + +is not changing over the +extent of an atom or molecule. + +In other words, what I'm telling +you is the relevant frequencies, + +the relevant components of the +electric and magnetic fields + +will, of course, +be the components + +which are in resonance with +the atoms and molecules. + +What I'm telling you is that +in many, many situations, + +the wavelengths of +the relevant modes + +of the electromagnetic +field are much, much longer + +than the size of an atom. + +So therefore, if we pinpoint +our atom at the origin, + +we may be able to neglect +the spatial dependence + +of the electromagnetic +fields and replace it + +by electric and magnetic +fields at the origin. + +Or, if you want to go higher +in a Taylor expansion, + +we use gradients of it. + +We've talked more +about that, actually, + +in 8.421, when we talked +about multipole transitions, + +but here I want to only focus +on the lowest order, which + +is called the electric +dipole approximation, + +because this is the most +important case which + +is used in atomic physics. + +So for the electric +dipole approximation, + +we make actually +several assumptions. + +One is we neglect the quadratic +term, the a squared term. + +And now if you look +at the A dot p term, + +and we are looking for +matrix elements between two + +atomic levels, we expand +the vector potential + +into plain waves. + +Well, it's called the +electric dipole approximation, + +so maybe we want +to express things + +by the electric field, which +is the derivative of the vector + +potential. + +So with that, we have +now described things + +by the electric field. + +And what is needed now is if +we assume that kr equals 0, + +or r over lambda is +very, very small, + +the exponential, the plain wave +vector, is approximated by 1, + +and we are simply left in the +electric dipole approximation + +with the a element of +the momentum operator. + +We can simplify it further by +writing the momentum operator + +as the commutator +between the position + +operator and the Hamiltonian. + +If you take the commutator +between r or x and p squared, + +you'd simply get +p and p factors, + +so that's what we are using. + +And now the matrix +element becomes-- + +so what we have here now is rH +minus Hr, but H acting on 1, + +because 1 is an eigenstate, +gives the energy, E1. + +And for the flipped +part, we have Hr, + +and now H acting on state +two gives us the energy, E2. + +So therefore, by taking care of +the Hamiltonian, which gives us, + +depending on which side +H appears, E1 or E2, + +we have reduced it to now +a position matrix element. + +And what we have here is, of +course, the transition frequency + +between the levels one and two. + +I know you have seen it, but if +I can derive it in two minutes, + +it's maybe worth the exercise. + +What I've shown you is that +the momentum matrix element + +can be replaced by the position +matrix element multiplied + +by the resonance frequency. + +But now we want to +put things together, + +and what I want to +point out for you + +is that we have an +omega here, which + +is the frequency of the +electromagnetic field, + +and we have an omega 12 here, +which is the transition energy. + +So therefore, if +I put it together, + +I started with a p +dot a Hamiltonian, + +but the p matrix element +became an r matrix element. + +The a was expressed +by the electric field. + +So therefore, we have +now the electric field + +times the position +matrix element, + +or the dipole matrix +element, if you + +multiply the position of the +electron with the charge two. + +But in addition, we +have this prefactor. + +So this becomes the +dipole Hamiltonian + +E dot d when we replace +that by 1, assuming + +that we are interested anyway +only in interactions with atoms + +where the radiation +field is near resonance. + +So it seems that +we have actually + +made three assumptions to +derive the electric dipole + +approximation. + +One was the long +wavelengths approximation. + +The second one was that +we are near resonance, + +and the third one was that we +neglected the quadratic term + +in the light-atom interaction. + +There are often people who +are wondering about it. + +When I said we are +only interested when + +the atoms interact with +electromagnetic radiation + +near resonance, that's +OK, but atomic physics + +is the area of physics +with the highest precision. + +We can make measurements with +10 to the minus 16 and 10 + +to the minus 17 precision. + +So therefore, if you have an +electromagnetic field which + +resonates with atoms-- + +the typical frequency of visible +light is 10 to the 14 Hertz-- + +and you're just one megahertz +away from the resonance, + +it's 10 to the minus 8. + +So the question is, would +we observe a correction + +to the dipole approximation if +omega 12 is not exactly omega? + +Well, the answer is no because, +as I want to show you now + +in the next few minutes, +and this is also + +the end of our flyover +over the appendix + +of atom-photon interaction, +the last two assumptions + +are not really necessary. + +In other words, we go back +to atom-photon interaction, + +to this long appendix on +the derivation of the QED + +Hamiltonian. + +We go back to our +fundamental Hamiltonian, + +and we want to do +one approximation + +and this is the only +approximation which is needed. + +It is the dipole +approximation, and that means + +that the vector potential-- + +of course, we only need +the transverse part of it-- + +is replaced by its +value at the origin. + +That's the only approximation. + +So here is our Hamiltonian +in its full beauty, + +and the only thing we have done +is we've put in the origin here. + +For later convenience, we +introduce the dipole operator, + +which is the position +operator of particle + +alpha times the charge +of particle alpha. + +And then we do simply +a transformation. + +So this is a unitary +transformation, + +and we transform from the +original Hamiltonian, which + +includes the p dot a term +and the a squared term + +to a transformed +Hamiltonian, H prime. + +And this transformed Hamiltonian +has now the electric dipole + +approximation. + +It's sort of written in +polarization Fourier space, + +but this is the electric field, +and a, a dagger gives position. + +I'm sorry. + +These are normal modes. + +It's a dipole operator +times the electric field, + +and the A squared +term has disappeared. + +So after the transformation, +we have no quadratic term, + +and all we are left is +this is nothing else than d + +dot e, the dipole interaction. + +And there is no prefactor +omega 12 over omega. + +This is a rigorous unitary +transformation to another basis. + +In full disclosure, it involves +a dipolar self energy, which + +is sort of a constant energy. + +And if you look at the +transformed velocities, + +the transformed +velocities v prime are now + +identical to the original +canonical momentum. + +So after that, what was +the canonical momentum + +in the original Hamiltonian, H, +becomes now velocity times mass. + +So p becomes now the +mechanical momentum. + +And therefore, p squared +is the kinetic energy. + +Anyway, I think +this is important + +that we have this much +more rigorous deviation + +of the dipole approximation. + +I don't want to go through that. + +I just want to make +sure you have seen it. + +If you want to do it +really rigorously, + +then you have to distinguish +between the electric field + +d and E. So you have +an electric field here, + +and here you have +the polarization. + +It's pretty much the same +as in classical e and m. + +At the end of the day, we have +now, for the prime operator, + +for the Hamiltonian after +the canonical transformation, + +after the unitary +transformation, + +the only interaction +term which remains + +is the electric dipole +interaction between the dipole + +and this field d, but this +field d prime corresponds + +to the original a +transverse electric field. + +I'm not going to explain +the difference between E, + +E prime, d, and d prime. + +It can be done rigorously. + +But the take home message +is-- and with that, + +I want to conclude-- + +that for most of this +course, the interaction + +of the electromagnetic +field with our atoms + +is described by this term. + +We take the transverse +electric field. + +This is our radiation +field, and it + +couples to the operator of +the atomic dipole moment. + +I hope you got the +take home message + +that whenever you have +any doubts about any part + +of this deviation, or if you +have any doubts whether it's + +rigorous or not, you know now +where to look it up and learn + +everything about it. + +Any questions? + +OK, then that's it. + +We'll probably post the first +homework assignment tomorrow-- + +I will meet with the TAs-- + +and it will be due +in about a week, + +but you will see all +of that on the website + +and hear from me on Wednesday. + +Have a good afternoon. \ No newline at end of file diff --git a/sV_yiHbMUF8.txt b/sV_yiHbMUF8.txt new file mode 100644 index 0000000000000000000000000000000000000000..2f4e583358b0891a005d8915003e5f513f8c44a5 --- /dev/null +++ b/sV_yiHbMUF8.txt @@ -0,0 +1,10616 @@ +align:start position:0% + +all right i guess we can get started + + align:start position:0% +all right i guess we can get started + + + align:start position:0% +all right i guess we can get started +so today we're going to talk about + + align:start position:0% +so today we're going to talk about + + + align:start position:0% +so today we're going to talk about +what's significant in laboratory + + align:start position:0% +what's significant in laboratory + + + align:start position:0% +what's significant in laboratory +measurement and how to take measurements + + align:start position:0% +measurement and how to take measurements + + + align:start position:0% +measurement and how to take measurements +in the lab how to do calculations with + + align:start position:0% +in the lab how to do calculations with + + + align:start position:0% +in the lab how to do calculations with +the lab and how to do some of the data + + align:start position:0% +the lab and how to do some of the data + + + align:start position:0% +the lab and how to do some of the data +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +when you have a lot of quantitative data + + align:start position:0% +when you have a lot of quantitative data + + + align:start position:0% +when you have a lot of quantitative data +which you will have + + align:start position:0% +which you will have + + + align:start position:0% +which you will have +in the lab coming up when we do the + + align:start position:0% +in the lab coming up when we do the + + + align:start position:0% +in the lab coming up when we do the +ellen swallow richards or the charles + + align:start position:0% +ellen swallow richards or the charles + + + align:start position:0% +ellen swallow richards or the charles +river lab + + align:start position:0% +river lab + + + align:start position:0% +river lab +one thing i wanted to point out so + + align:start position:0% +one thing i wanted to point out so + + + align:start position:0% +one thing i wanted to point out so +there's handouts in the back we're going + + align:start position:0% +there's handouts in the back we're going + + + align:start position:0% +there's handouts in the back we're going +to be going through + + align:start position:0% +to be going through + + + align:start position:0% +to be going through +how to do the calculations and how to do + + align:start position:0% +how to do the calculations and how to do + + + align:start position:0% +how to do the calculations and how to do +all the statistics + + align:start position:0% +all the statistics + + + align:start position:0% +all the statistics +and there's an example problem that + + align:start position:0% +and there's an example problem that + + + align:start position:0% +and there's an example problem that +we're going to work through + + align:start position:0% +we're going to work through + + + align:start position:0% +we're going to work through +as we go in the back so if you want to + + align:start position:0% +as we go in the back so if you want to + + + align:start position:0% +as we go in the back so if you want to +make sure you have a copy of that that + + align:start position:0% +make sure you have a copy of that that + + + align:start position:0% +make sure you have a copy of that that +might be helpful + + align:start position:0% +might be helpful + + + align:start position:0% +might be helpful +and one of the things that was pointed + + align:start position:0% +and one of the things that was pointed + + + align:start position:0% +and one of the things that was pointed +out this week in the lab is that in the + + align:start position:0% +out this week in the lab is that in the + + + align:start position:0% +out this week in the lab is that in the +lab there is a typo left over from when + + align:start position:0% +lab there is a typo left over from when + + + align:start position:0% +lab there is a typo left over from when +we were in the old labs in building four + + align:start position:0% +we were in the old labs in building four + + + align:start position:0% +we were in the old labs in building four +and so the this wednesday and thursday + + align:start position:0% +and so the this wednesday and thursday + + + align:start position:0% +and so the this wednesday and thursday +the ta session that it says the help + + align:start position:0% +the ta session that it says the help + + + align:start position:0% +the ta session that it says the help +session about how to write the ferrocene + + align:start position:0% +session about how to write the ferrocene + + + align:start position:0% +session about how to write the ferrocene +lab report is going to be in the lab + + align:start position:0% +lab report is going to be in the lab + + + align:start position:0% +lab report is going to be in the lab +not in for 4 30 as it says in the lab + + align:start position:0% +not in for 4 30 as it says in the lab + + + align:start position:0% +not in for 4 30 as it says in the lab +manual + + align:start position:0% +manual + + + align:start position:0% +manual +so just come to lab as normal the + + align:start position:0% +so just come to lab as normal the + + + align:start position:0% +so just come to lab as normal the +beginning of the lab period will be + + align:start position:0% +beginning of the lab period will be + + + align:start position:0% +beginning of the lab period will be +a quiz on the ferrising lab so anything + + align:start position:0% +a quiz on the ferrising lab so anything + + + align:start position:0% +a quiz on the ferrising lab so anything +procedure-wise calculations reactions + + align:start position:0% +procedure-wise calculations reactions + + + align:start position:0% +procedure-wise calculations reactions +all that good stuff things that you + + align:start position:0% +all that good stuff things that you + + + align:start position:0% +all that good stuff things that you +should know having done the ferrising + + align:start position:0% +should know having done the ferrising + + + align:start position:0% +should know having done the ferrising +lab and hopefully having started to + + align:start position:0% +lab and hopefully having started to + + + align:start position:0% +lab and hopefully having started to +write up your report a little bit + + align:start position:0% +write up your report a little bit + + + align:start position:0% +write up your report a little bit +and then after the first 20 minutes or + + align:start position:0% +and then after the first 20 minutes or + + + align:start position:0% +and then after the first 20 minutes or +so is going to be the quiz and then your + + align:start position:0% +so is going to be the quiz and then your + + + align:start position:0% +so is going to be the quiz and then your +tas will + + align:start position:0% +tas will + + + align:start position:0% +tas will +give a little bit of a lecture about + + align:start position:0% +give a little bit of a lecture about + + + align:start position:0% +give a little bit of a lecture about +what they're looking for in the + + align:start position:0% +what they're looking for in the + + + align:start position:0% +what they're looking for in the +ferrocene reports + + align:start position:0% +ferrocene reports + + + align:start position:0% +ferrocene reports +so that's a good time to ask any + + align:start position:0% +so that's a good time to ask any + + + align:start position:0% +so that's a good time to ask any +questions about if you're unsure about + + align:start position:0% +questions about if you're unsure about + + + align:start position:0% +questions about if you're unsure about +where to + + align:start position:0% +where to + + + align:start position:0% +where to +write anything how to write anything up + + align:start position:0% +write anything how to write anything up + + + align:start position:0% +write anything how to write anything up +if you have anything that you've already + + align:start position:0% +if you have anything that you've already + + + align:start position:0% +if you have anything that you've already +written and you want them to look at + + align:start position:0% +written and you want them to look at + + + align:start position:0% +written and you want them to look at +they will be in the lab to help you out + + align:start position:0% +they will be in the lab to help you out + + + align:start position:0% +they will be in the lab to help you out +with that and they have we have some + + align:start position:0% +with that and they have we have some + + + align:start position:0% +with that and they have we have some +more office hours too that got posted to + + align:start position:0% +more office hours too that got posted to + + + align:start position:0% +more office hours too that got posted to +stellar and i will + + align:start position:0% +stellar and i will + + + align:start position:0% +stellar and i will +have a slide about them at the end of + + align:start position:0% +have a slide about them at the end of + + + align:start position:0% +have a slide about them at the end of +this lecture too + + align:start position:0% +this lecture too + + + align:start position:0% +this lecture too +for more help but um yeah day four of + + align:start position:0% +for more help but um yeah day four of + + + align:start position:0% +for more help but um yeah day four of +ferrocene come take the quiz + + align:start position:0% +ferrocene come take the quiz + + + align:start position:0% +ferrocene come take the quiz +then get some help on your reports it is + + align:start position:0% +then get some help on your reports it is + + + align:start position:0% +then get some help on your reports it is +in the lab you don't have to go anywhere + + align:start position:0% +in the lab you don't have to go anywhere + + + align:start position:0% +in the lab you don't have to go anywhere +else just come to lab as normal + + align:start position:0% +else just come to lab as normal + + + align:start position:0% +else just come to lab as normal +okay so if we're going to be talking + + align:start position:0% +okay so if we're going to be talking + + + align:start position:0% +okay so if we're going to be talking +about measurement today + + align:start position:0% +about measurement today + + + align:start position:0% +about measurement today +then we need to talk about what things + + align:start position:0% +then we need to talk about what things + + + align:start position:0% +then we need to talk about what things +you should be thinking about if you're + + align:start position:0% +you should be thinking about if you're + + + align:start position:0% +you should be thinking about if you're +going to measure something + + align:start position:0% +going to measure something + + + align:start position:0% +going to measure something +so if you're going to measure the length + + align:start position:0% +so if you're going to measure the length + + + align:start position:0% +so if you're going to measure the length +of this piece of wood with + + align:start position:0% +of this piece of wood with + + + align:start position:0% +of this piece of wood with +this ruler how long would you be able to + + align:start position:0% +this ruler how long would you be able to + + + align:start position:0% +this ruler how long would you be able to +say this piece of wood is + + align:start position:0% +say this piece of wood is + + + align:start position:0% +say this piece of wood is +no good there's no units yeah that's a + + align:start position:0% +no good there's no units yeah that's a + + + align:start position:0% +no good there's no units yeah that's a +problem what else is what else is wrong + + align:start position:0% +problem what else is what else is wrong + + + align:start position:0% +problem what else is what else is wrong +it's not it's not long enough so what's + + align:start position:0% +it's not it's not long enough so what's + + + align:start position:0% +it's not it's not long enough so what's +the minimum we could say + + align:start position:0% +the minimum we could say + + + align:start position:0% +the minimum we could say +about this piece of wood + + align:start position:0% + + + + align:start position:0% + +it's longer than one something + + align:start position:0% +it's longer than one something + + + align:start position:0% +it's longer than one something +so this is not a great measuring tool + + align:start position:0% +so this is not a great measuring tool + + + align:start position:0% +so this is not a great measuring tool +what about this + + align:start position:0% +what about this + + + align:start position:0% +what about this +any better slightly better + + align:start position:0% +any better slightly better + + + align:start position:0% +any better slightly better +so now what could we say about the + + align:start position:0% +so now what could we say about the + + + align:start position:0% +so now what could we say about the +length of the piece of wood + + align:start position:0% +length of the piece of wood + + + align:start position:0% +length of the piece of wood +it's between one and two probably a + + align:start position:0% +it's between one and two probably a + + + align:start position:0% +it's between one and two probably a +little closer to two + + align:start position:0% +little closer to two + + + align:start position:0% +little closer to two +but we can't really say too much more + + align:start position:0% +but we can't really say too much more + + + align:start position:0% +but we can't really say too much more +about it than that and we still don't + + align:start position:0% +about it than that and we still don't + + + align:start position:0% +about it than that and we still don't +have any units + + align:start position:0% +have any units + + + align:start position:0% +have any units +so this is just to kind of get you + + align:start position:0% +so this is just to kind of get you + + + align:start position:0% +so this is just to kind of get you +thinking about what we need to be + + align:start position:0% +thinking about what we need to be + + + align:start position:0% +thinking about what we need to be +considering when we are choosing how + + align:start position:0% +considering when we are choosing how + + + align:start position:0% +considering when we are choosing how +we're going to measure something + + align:start position:0% +we're going to measure something + + + align:start position:0% +we're going to measure something +and when we're recording measurements + + align:start position:0% +and when we're recording measurements + + + align:start position:0% +and when we're recording measurements +what information we can reasonably get + + align:start position:0% +what information we can reasonably get + + + align:start position:0% +what information we can reasonably get +from the measuring tools that we're + + align:start position:0% +from the measuring tools that we're + + + align:start position:0% +from the measuring tools that we're +using + + align:start position:0% +using + + + align:start position:0% +using +so to talk about measurements a little + + align:start position:0% +so to talk about measurements a little + + + align:start position:0% +so to talk about measurements a little +bit more we're going to need to talk + + align:start position:0% +bit more we're going to need to talk + + + align:start position:0% +bit more we're going to need to talk +about some terminology and get this out + + align:start position:0% +about some terminology and get this out + + + align:start position:0% +about some terminology and get this out +of the way so that we're all using the + + align:start position:0% +of the way so that we're all using the + + + align:start position:0% +of the way so that we're all using the +same language and you've probably seen + + align:start position:0% +same language and you've probably seen + + + align:start position:0% +same language and you've probably seen +these terms before in your other science + + align:start position:0% +these terms before in your other science + + + align:start position:0% +these terms before in your other science +classes in high school and middle school + + align:start position:0% +classes in high school and middle school + + + align:start position:0% +classes in high school and middle school +going way back + + align:start position:0% +going way back + + + align:start position:0% +going way back +but to just as a quick refresher so + + align:start position:0% +but to just as a quick refresher so + + + align:start position:0% +but to just as a quick refresher so +we're all on the same page + + align:start position:0% +we're all on the same page + + + align:start position:0% +we're all on the same page +precision is how close repeated + + align:start position:0% +precision is how close repeated + + + align:start position:0% +precision is how close repeated +measurements are to one another so if + + align:start position:0% +measurements are to one another so if + + + align:start position:0% +measurements are to one another so if +you measure the same thing a bunch of + + align:start position:0% +you measure the same thing a bunch of + + + align:start position:0% +you measure the same thing a bunch of +times you would like the + + align:start position:0% +times you would like the + + + align:start position:0% +times you would like the +results to be the same you've probably + + align:start position:0% +results to be the same you've probably + + + align:start position:0% +results to be the same you've probably +seen these bullseye diagrams where + + align:start position:0% +seen these bullseye diagrams where + + + align:start position:0% +seen these bullseye diagrams where +if the results are all really close + + align:start position:0% +if the results are all really close + + + align:start position:0% +if the results are all really close +together that is very precise + + align:start position:0% +together that is very precise + + + align:start position:0% +together that is very precise +um you can measure that with the + + align:start position:0% +um you can measure that with the + + + align:start position:0% +um you can measure that with the +standard deviation so the standard + + align:start position:0% +standard deviation so the standard + + + align:start position:0% +standard deviation so the standard +deviation gives you an idea of + + align:start position:0% +deviation gives you an idea of + + + align:start position:0% +deviation gives you an idea of +relatively how close your points are to + + align:start position:0% +relatively how close your points are to + + + align:start position:0% +relatively how close your points are to +each other + + align:start position:0% +each other + + + align:start position:0% +each other +accuracy is how close a measurement is + + align:start position:0% +accuracy is how close a measurement is + + + align:start position:0% +accuracy is how close a measurement is +to the true value or the value that you + + align:start position:0% +to the true value or the value that you + + + align:start position:0% +to the true value or the value that you +actually are trying to measure + + align:start position:0% +actually are trying to measure + + + align:start position:0% +actually are trying to measure +so if you are throwing darts and you are + + align:start position:0% +so if you are throwing darts and you are + + + align:start position:0% +so if you are throwing darts and you are +trying to get the bullseye + + align:start position:0% +trying to get the bullseye + + + align:start position:0% +trying to get the bullseye +then if you have high accuracy then you + + align:start position:0% +then if you have high accuracy then you + + + align:start position:0% +then if you have high accuracy then you +have them all in the bull's-eye + + align:start position:0% +have them all in the bull's-eye + + + align:start position:0% +have them all in the bull's-eye +if you have a high accuracy and high + + align:start position:0% +if you have a high accuracy and high + + + align:start position:0% +if you have a high accuracy and high +precision then all of your darts always + + align:start position:0% +precision then all of your darts always + + + align:start position:0% +precision then all of your darts always +go to the center + + align:start position:0% +go to the center + + + align:start position:0% +go to the center +you can have high accuracy where you're + + align:start position:0% +you can have high accuracy where you're + + + align:start position:0% +you can have high accuracy where you're +always kind of around the target but + + align:start position:0% +always kind of around the target but + + + align:start position:0% +always kind of around the target but +your + + align:start position:0% +your + + + align:start position:0% +your +points are scattered and then you can + + align:start position:0% +points are scattered and then you can + + + align:start position:0% +points are scattered and then you can +have low accuracy and low precision + + align:start position:0% +have low accuracy and low precision + + + align:start position:0% +have low accuracy and low precision +where you're just + + align:start position:0% +where you're just + + + align:start position:0% +where you're just +all over the place we measure accuracy + + align:start position:0% +all over the place we measure accuracy + + + align:start position:0% +all over the place we measure accuracy +by the + + align:start position:0% +by the + + + align:start position:0% +by the +percent error so it's the error relative + + align:start position:0% +percent error so it's the error relative + + + align:start position:0% +percent error so it's the error relative +to + + align:start position:0% +to + + + align:start position:0% +to +the result that you're trying to get and + + align:start position:0% +the result that you're trying to get and + + + align:start position:0% +the result that you're trying to get and +the answers don't need to be + + align:start position:0% +the answers don't need to be + + + align:start position:0% +the answers don't need to be +close to each other to be accurate like + + align:start position:0% +close to each other to be accurate like + + + align:start position:0% +close to each other to be accurate like +i said they can be kind of spread out + + align:start position:0% +i said they can be kind of spread out + + + align:start position:0% +i said they can be kind of spread out +but still all + + align:start position:0% +but still all + + + align:start position:0% +but still all +close to the target value + + align:start position:0% +close to the target value + + + align:start position:0% +close to the target value +so these are some terms that you've + + align:start position:0% +so these are some terms that you've + + + align:start position:0% +so these are some terms that you've +probably heard they're a little bit used + + align:start position:0% +probably heard they're a little bit used + + + align:start position:0% +probably heard they're a little bit used +differently in chemistry sometimes then + + align:start position:0% +differently in chemistry sometimes then + + + align:start position:0% +differently in chemistry sometimes then +you may use them colloquially so we just + + align:start position:0% +you may use them colloquially so we just + + + align:start position:0% +you may use them colloquially so we just +want to go over that + + align:start position:0% +want to go over that + + + align:start position:0% +want to go over that +more terminology absolute error is how + + align:start position:0% +more terminology absolute error is how + + + align:start position:0% +more terminology absolute error is how +far + + align:start position:0% +far + + + align:start position:0% +far +away a measurement is from the true or + + align:start position:0% +away a measurement is from the true or + + + align:start position:0% +away a measurement is from the true or +accepted value + + align:start position:0% +accepted value + + + align:start position:0% +accepted value +so if you're trying to measure let's see + + align:start position:0% +so if you're trying to measure let's see + + + align:start position:0% +so if you're trying to measure let's see +with + + align:start position:0% +with + + + align:start position:0% +with +this here pipette it has 10 + + align:start position:0% +this here pipette it has 10 + + + align:start position:0% +this here pipette it has 10 +this pipette is designed to measure 10 + + align:start position:0% +this pipette is designed to measure 10 + + + align:start position:0% +this pipette is designed to measure 10 +milliliters and you can look at it and + + align:start position:0% +milliliters and you can look at it and + + + align:start position:0% +milliliters and you can look at it and +it has a tolerance of 0.04 milliliters + + align:start position:0% +it has a tolerance of 0.04 milliliters + + + align:start position:0% +it has a tolerance of 0.04 milliliters +so that's an absolute error it is how + + align:start position:0% +so that's an absolute error it is how + + + align:start position:0% +so that's an absolute error it is how +far away your measurement will be from + + align:start position:0% +far away your measurement will be from + + + align:start position:0% +far away your measurement will be from +the true value if you're trying to + + align:start position:0% +the true value if you're trying to + + + align:start position:0% +the true value if you're trying to +measure 10 and you measure + + align:start position:0% +measure 10 and you measure + + + align:start position:0% +measure 10 and you measure +10.04 then your absolute error is 0.04 + + align:start position:0% +10.04 then your absolute error is 0.04 + + + align:start position:0% +10.04 then your absolute error is 0.04 +milliliters + + align:start position:0% +milliliters + + + align:start position:0% +milliliters +so you just subtract what you got from + + align:start position:0% +so you just subtract what you got from + + + align:start position:0% +so you just subtract what you got from +what you intended to get + + align:start position:0% +what you intended to get + + + align:start position:0% +what you intended to get +the relative error is how far a + + align:start position:0% +the relative error is how far a + + + align:start position:0% +the relative error is how far a +measurement is from the true value but + + align:start position:0% +measurement is from the true value but + + + align:start position:0% +measurement is from the true value but +it's relative to the quantity that + + align:start position:0% +it's relative to the quantity that + + + align:start position:0% +it's relative to the quantity that +you're trying to measure + + align:start position:0% +you're trying to measure + + + align:start position:0% +you're trying to measure +so if you have if you've measured .04 + + align:start position:0% +so if you have if you've measured .04 + + + align:start position:0% +so if you have if you've measured .04 +or 10.04 and you intended to measure 10 + + align:start position:0% +or 10.04 and you intended to measure 10 + + + align:start position:0% +or 10.04 and you intended to measure 10 +then your absolute error is the .04 + + align:start position:0% +then your absolute error is the .04 + + + align:start position:0% +then your absolute error is the .04 +to get your relative error you'll make + + align:start position:0% +to get your relative error you'll make + + + align:start position:0% +to get your relative error you'll make +it a percent and divide it by the 10 + + align:start position:0% +it a percent and divide it by the 10 + + + align:start position:0% +it a percent and divide it by the 10 +that you intended to measure so now you + + align:start position:0% +that you intended to measure so now you + + + align:start position:0% +that you intended to measure so now you +have a 0.4 percent error + + align:start position:0% + + + + align:start position:0% + +one way to think about this is if you + + align:start position:0% +one way to think about this is if you + + + align:start position:0% +one way to think about this is if you +have an absolute error of one milliliter + + align:start position:0% +have an absolute error of one milliliter + + + align:start position:0% +have an absolute error of one milliliter +when you're measuring out 2.5 liters of + + align:start position:0% +when you're measuring out 2.5 liters of + + + align:start position:0% +when you're measuring out 2.5 liters of +material that's pretty small + + align:start position:0% +material that's pretty small + + + align:start position:0% +material that's pretty small +but if you have an absolute error of one + + align:start position:0% +but if you have an absolute error of one + + + align:start position:0% +but if you have an absolute error of one +milliliter when you're measuring out 2.5 + + align:start position:0% +milliliter when you're measuring out 2.5 + + + align:start position:0% +milliliter when you're measuring out 2.5 +milliliters of material then that + + align:start position:0% +milliliters of material then that + + + align:start position:0% +milliliters of material then that +becomes a much bigger problem + + align:start position:0% +becomes a much bigger problem + + + align:start position:0% +becomes a much bigger problem +so depending on the quantity that you're + + align:start position:0% +so depending on the quantity that you're + + + align:start position:0% +so depending on the quantity that you're +measuring sometimes it's a little bit + + align:start position:0% +measuring sometimes it's a little bit + + + align:start position:0% +measuring sometimes it's a little bit +more useful to report the relative error + + align:start position:0% +more useful to report the relative error + + + align:start position:0% +more useful to report the relative error +than + + align:start position:0% +than + + + align:start position:0% +than +the absolute error and vice versa + + align:start position:0% +the absolute error and vice versa + + + align:start position:0% +the absolute error and vice versa +depending on the application + + align:start position:0% +depending on the application + + + align:start position:0% +depending on the application +if you say yeah i had an error of one + + align:start position:0% +if you say yeah i had an error of one + + + align:start position:0% +if you say yeah i had an error of one +milliliter and your friends are all + + align:start position:0% +milliliter and your friends are all + + + align:start position:0% +milliliter and your friends are all +saying oh you did such a great job and + + align:start position:0% +saying oh you did such a great job and + + + align:start position:0% +saying oh you did such a great job and +then you say i was only trying to + + align:start position:0% +then you say i was only trying to + + + align:start position:0% +then you say i was only trying to +measure two milliliters then + + align:start position:0% +measure two milliliters then + + + align:start position:0% +measure two milliliters then +not so great + + align:start position:0% + + + + align:start position:0% + +other types of error are random error + + align:start position:0% +other types of error are random error + + + align:start position:0% +other types of error are random error +and systematic error so random error + + align:start position:0% +and systematic error so random error + + + align:start position:0% +and systematic error so random error +is things that we can't really control + + align:start position:0% +is things that we can't really control + + + align:start position:0% +is things that we can't really control +for + + align:start position:0% +for + + + align:start position:0% +for +or identify and it causes data to + + align:start position:0% +or identify and it causes data to + + + align:start position:0% +or identify and it causes data to +fluctuate relatively uniformly around a + + align:start position:0% +fluctuate relatively uniformly around a + + + align:start position:0% +fluctuate relatively uniformly around a +mean value + + align:start position:0% +mean value + + + align:start position:0% +mean value +and that's one of the things that's + + align:start position:0% +and that's one of the things that's + + + align:start position:0% +and that's one of the things that's +given on the uncertainty in + + align:start position:0% +given on the uncertainty in + + + align:start position:0% +given on the uncertainty in +the measuring apparatus that you're + + align:start position:0% +the measuring apparatus that you're + + + align:start position:0% +the measuring apparatus that you're +using so this pipette measures 10 + + align:start position:0% +using so this pipette measures 10 + + + align:start position:0% +using so this pipette measures 10 +milliliters plus or minus .04 + + align:start position:0% +milliliters plus or minus .04 + + + align:start position:0% +milliliters plus or minus .04 +milliliters + + align:start position:0% +milliliters + + + align:start position:0% +milliliters +that is a random or indeterminate error + + align:start position:0% +that is a random or indeterminate error + + + align:start position:0% +that is a random or indeterminate error +the data will fluctuate around 10 + + align:start position:0% +the data will fluctuate around 10 + + + align:start position:0% +the data will fluctuate around 10 +milliliters within .04 + + align:start position:0% +milliliters within .04 + + + align:start position:0% +milliliters within .04 +you know that and you can control for + + align:start position:0% +you know that and you can control for + + + align:start position:0% +you know that and you can control for +that using statistical analysis which + + align:start position:0% +that using statistical analysis which + + + align:start position:0% +that using statistical analysis which +we'll talk about in a little bit + + align:start position:0% +we'll talk about in a little bit + + + align:start position:0% +we'll talk about in a little bit +systematic or determinate error is error + + align:start position:0% +systematic or determinate error is error + + + align:start position:0% +systematic or determinate error is error +that has a known cause + + align:start position:0% +that has a known cause + + + align:start position:0% +that has a known cause +and that could be from faulty or poorly + + align:start position:0% +and that could be from faulty or poorly + + + align:start position:0% +and that could be from faulty or poorly +calibrated instruments + + align:start position:0% +calibrated instruments + + + align:start position:0% +calibrated instruments +human error or chemical behavior and + + align:start position:0% +human error or chemical behavior and + + + align:start position:0% +human error or chemical behavior and +side reactions + + align:start position:0% +side reactions + + + align:start position:0% +side reactions +so if you intended to get five grams of + + align:start position:0% +so if you intended to get five grams of + + + align:start position:0% +so if you intended to get five grams of +product and you got less than five grams + + align:start position:0% +product and you got less than five grams + + + align:start position:0% +product and you got less than five grams +then you know that there is some error + + align:start position:0% +then you know that there is some error + + + align:start position:0% +then you know that there is some error +associated with + + align:start position:0% +associated with + + + align:start position:0% +associated with +your experiment and it could be because + + align:start position:0% +your experiment and it could be because + + + align:start position:0% +your experiment and it could be because +some maybe some of your + + align:start position:0% +some maybe some of your + + + align:start position:0% +some maybe some of your +iron oxidized or maybe you spilled some + + align:start position:0% +iron oxidized or maybe you spilled some + + + align:start position:0% +iron oxidized or maybe you spilled some +of your + + align:start position:0% +of your + + + align:start position:0% +of your +ferrocene or maybe you were not tearing + + align:start position:0% +ferrocene or maybe you were not tearing + + + align:start position:0% +ferrocene or maybe you were not tearing +the balance every time you used it so + + align:start position:0% +the balance every time you used it so + + + align:start position:0% +the balance every time you used it so +that'll + + align:start position:0% +that'll + + + align:start position:0% +that'll +introduce error into your measurement if + + align:start position:0% +introduce error into your measurement if + + + align:start position:0% +introduce error into your measurement if +you were using + + align:start position:0% +you were using + + + align:start position:0% +you were using +the equipment improperly or if you're + + align:start position:0% +the equipment improperly or if you're + + + align:start position:0% +the equipment improperly or if you're +reading from a buret and you're always + + align:start position:0% +reading from a buret and you're always + + + align:start position:0% +reading from a buret and you're always +reading in the wrong direction or you + + align:start position:0% +reading in the wrong direction or you + + + align:start position:0% +reading in the wrong direction or you +didn't read to enough significant + + align:start position:0% +didn't read to enough significant + + + align:start position:0% +didn't read to enough significant +figures + + align:start position:0% +figures + + + align:start position:0% +figures +that systematic error and so that's not + + align:start position:0% +that systematic error and so that's not + + + align:start position:0% +that systematic error and so that's not +necessarily from the glassware itself + + align:start position:0% +necessarily from the glassware itself + + + align:start position:0% +necessarily from the glassware itself +that's from + + align:start position:0% +that's from + + + align:start position:0% +that's from +how you were using it and these are + + align:start position:0% +how you were using it and these are + + + align:start position:0% +how you were using it and these are +types of error that you can talk about + + align:start position:0% +types of error that you can talk about + + + align:start position:0% +types of error that you can talk about +in your discussion section of your lab + + align:start position:0% +in your discussion section of your lab + + + align:start position:0% +in your discussion section of your lab +report + + align:start position:0% +report + + + align:start position:0% +report +so you can talk about the error that is + + align:start position:0% +so you can talk about the error that is + + + align:start position:0% +so you can talk about the error that is +associated with the measurements that + + align:start position:0% +associated with the measurements that + + + align:start position:0% +associated with the measurements that +you can control and that you cannot + + align:start position:0% + + + + align:start position:0% + +control + + align:start position:0% +control + + + align:start position:0% +control +the last term that we need to talk about + + align:start position:0% +the last term that we need to talk about + + + align:start position:0% +the last term that we need to talk about +in terms of + + align:start position:0% +in terms of + + + align:start position:0% +in terms of +when we're making measurements or doing + + align:start position:0% +when we're making measurements or doing + + + align:start position:0% +when we're making measurements or doing +things in the lab is what does it mean + + align:start position:0% +things in the lab is what does it mean + + + align:start position:0% +things in the lab is what does it mean +for something to be significant + + align:start position:0% +for something to be significant + + + align:start position:0% +for something to be significant +so you may have heard of the term + + align:start position:0% +so you may have heard of the term + + + align:start position:0% +so you may have heard of the term +significant figures or + + align:start position:0% +significant figures or + + + align:start position:0% +significant figures or +this is a significant result what does + + align:start position:0% +this is a significant result what does + + + align:start position:0% +this is a significant result what does +it mean for a number or measurement to + + align:start position:0% +it mean for a number or measurement to + + + align:start position:0% +it mean for a number or measurement to +be + + align:start position:0% +be + + + align:start position:0% +be +significant in what makes a measurement + + align:start position:0% +significant in what makes a measurement + + + align:start position:0% +significant in what makes a measurement +that we take significant in the lab + + align:start position:0% + + + + align:start position:0% + +yeah i feel significant means like all + + align:start position:0% +yeah i feel significant means like all + + + align:start position:0% +yeah i feel significant means like all +the numbers that you're certain + + align:start position:0% +the numbers that you're certain + + + align:start position:0% +the numbers that you're certain +about less than one estimate one final + + align:start position:0% +about less than one estimate one final + + + align:start position:0% +about less than one estimate one final +exactly yeah so a number is + + align:start position:0% +exactly yeah so a number is + + + align:start position:0% +exactly yeah so a number is +significant and you report the + + align:start position:0% +significant and you report the + + + align:start position:0% +significant and you report the +significant figures + + align:start position:0% +significant figures + + + align:start position:0% +significant figures +are in a measurement all of the numbers + + align:start position:0% +are in a measurement all of the numbers + + + align:start position:0% +are in a measurement all of the numbers +that you're certain of + + align:start position:0% +that you're certain of + + + align:start position:0% +that you're certain of +plus the first uncertain digit so a lot + + align:start position:0% +plus the first uncertain digit so a lot + + + align:start position:0% +plus the first uncertain digit so a lot +of times you'll have + + align:start position:0% +of times you'll have + + + align:start position:0% +of times you'll have +some sort of your you won't have + + align:start position:0% +some sort of your you won't have + + + align:start position:0% +some sort of your you won't have +measurements every maybe tenth of a + + align:start position:0% +measurements every maybe tenth of a + + + align:start position:0% +measurements every maybe tenth of a +milliliter or + + align:start position:0% +milliliter or + + + align:start position:0% +milliliter or +one milliliter depending on the size of + + align:start position:0% +one milliliter depending on the size of + + + align:start position:0% +one milliliter depending on the size of +the glassware that you're using + + align:start position:0% +the glassware that you're using + + + align:start position:0% +the glassware that you're using +so you can be certain of some of the + + align:start position:0% +so you can be certain of some of the + + + align:start position:0% +so you can be certain of some of the +measurements and then you're uncertain + + align:start position:0% +measurements and then you're uncertain + + + align:start position:0% +measurements and then you're uncertain +of others so in our piece of wood we + + align:start position:0% +of others so in our piece of wood we + + + align:start position:0% +of others so in our piece of wood we +were certain that it was bigger than one + + align:start position:0% +were certain that it was bigger than one + + + align:start position:0% +were certain that it was bigger than one +but we were uncertain of the next digit + + align:start position:0% +but we were uncertain of the next digit + + + align:start position:0% +but we were uncertain of the next digit +so we could estimate that second digit + + align:start position:0% +so we could estimate that second digit + + + align:start position:0% +so we could estimate that second digit +and that counts as + + align:start position:0% +and that counts as + + + align:start position:0% +and that counts as +significant + + align:start position:0% + + + + align:start position:0% + +a quick review of significant figures + + align:start position:0% +a quick review of significant figures + + + align:start position:0% +a quick review of significant figures +and how to + + align:start position:0% +and how to + + + align:start position:0% +and how to +use them all non-zero digits in a number + + align:start position:0% +use them all non-zero digits in a number + + + align:start position:0% +use them all non-zero digits in a number +are significant + + align:start position:0% +are significant + + + align:start position:0% +are significant +zeros in between non-zero digits are + + align:start position:0% +zeros in between non-zero digits are + + + align:start position:0% +zeros in between non-zero digits are +also significant + + align:start position:0% +also significant + + + align:start position:0% +also significant +zeros to the left of a non-zero digit + + align:start position:0% +zeros to the left of a non-zero digit + + + align:start position:0% +zeros to the left of a non-zero digit +are not significant + + align:start position:0% +are not significant + + + align:start position:0% +are not significant +zeros to the right are only significant + + align:start position:0% +zeros to the right are only significant + + + align:start position:0% +zeros to the right are only significant +if there's a decimal place + + align:start position:0% +if there's a decimal place + + + align:start position:0% +if there's a decimal place +and you can avoid ambiguity in that with + + align:start position:0% +and you can avoid ambiguity in that with + + + align:start position:0% +and you can avoid ambiguity in that with +scientific notation + + align:start position:0% +scientific notation + + + align:start position:0% +scientific notation +so if we just go through these really + + align:start position:0% +so if we just go through these really + + + align:start position:0% +so if we just go through these really +quickly how many significant figures + + align:start position:0% +quickly how many significant figures + + + align:start position:0% +quickly how many significant figures +does this have + + align:start position:0% +does this have + + + align:start position:0% +does this have +four three + + align:start position:0% + + + + align:start position:0% + +six two two maybe + + align:start position:0% +six two two maybe + + + align:start position:0% +six two two maybe +as written yeah you would probably call + + align:start position:0% +as written yeah you would probably call + + + align:start position:0% +as written yeah you would probably call +it two because the zero's to the right + + align:start position:0% +it two because the zero's to the right + + + align:start position:0% +it two because the zero's to the right +but if you wanted this zero to be + + align:start position:0% +but if you wanted this zero to be + + + align:start position:0% +but if you wanted this zero to be +significant then you could write it + + align:start position:0% +significant then you could write it + + + align:start position:0% +significant then you could write it +like this and now how many significant + + align:start position:0% +like this and now how many significant + + + align:start position:0% +like this and now how many significant +figures do we have three + + align:start position:0% +figures do we have three + + + align:start position:0% +figures do we have three +and if the zero is not significant then + + align:start position:0% +and if the zero is not significant then + + + align:start position:0% +and if the zero is not significant then +to avoid people being confused about it + + align:start position:0% +to avoid people being confused about it + + + align:start position:0% +to avoid people being confused about it +you could write it like this and we have + + align:start position:0% +you could write it like this and we have + + + align:start position:0% +you could write it like this and we have +two so that's one way you can use + + align:start position:0% +two so that's one way you can use + + + align:start position:0% +two so that's one way you can use +scientific notation to get around + + align:start position:0% +scientific notation to get around + + + align:start position:0% +scientific notation to get around +ambiguity yes you have a question so for + + align:start position:0% +ambiguity yes you have a question so for + + + align:start position:0% +ambiguity yes you have a question so for +590 if someone put a decimal point after + + align:start position:0% +590 if someone put a decimal point after + + + align:start position:0% +590 if someone put a decimal point after +the zero weights would be three + + align:start position:0% +the zero weights would be three + + + align:start position:0% +the zero weights would be three +significant figures it would be two + + align:start position:0% +significant figures it would be two + + + align:start position:0% +significant figures it would be two +so that's a question that i've always + + align:start position:0% +so that's a question that i've always + + + align:start position:0% +so that's a question that i've always +gotten um i think just conventionally + + align:start position:0% +gotten um i think just conventionally + + + align:start position:0% +gotten um i think just conventionally +speaking if you wrote something as + + align:start position:0% +speaking if you wrote something as + + + align:start position:0% +speaking if you wrote something as +like like this + + align:start position:0% + + + + align:start position:0% + +maybe um more conventionally correct + + align:start position:0% +maybe um more conventionally correct + + + align:start position:0% +maybe um more conventionally correct +would be to + + align:start position:0% +would be to + + + align:start position:0% +would be to +write it as 5.90 times 10 to the 2 + + align:start position:0% +write it as 5.90 times 10 to the 2 + + + align:start position:0% +write it as 5.90 times 10 to the 2 +because you don't usually have a decimal + + align:start position:0% +because you don't usually have a decimal + + + align:start position:0% +because you don't usually have a decimal +place if there's nothing after it + + align:start position:0% +place if there's nothing after it + + + align:start position:0% +place if there's nothing after it +and then if you wrote it like this + + align:start position:0% +and then if you wrote it like this + + + align:start position:0% +and then if you wrote it like this +though then you have four significant + + align:start position:0% +though then you have four significant + + + align:start position:0% +though then you have four significant +figures and that's more than you want + + align:start position:0% + + + + align:start position:0% + +so just go with the the scientific + + align:start position:0% +so just go with the the scientific + + + align:start position:0% +so just go with the the scientific +notation instead of having a hanging + + align:start position:0% +notation instead of having a hanging + + + align:start position:0% +notation instead of having a hanging +decimal place + + align:start position:0% +decimal place + + + align:start position:0% +decimal place +so that's not a typical way to write + + align:start position:0% +so that's not a typical way to write + + + align:start position:0% +so that's not a typical way to write +numbers + + align:start position:0% + + + + align:start position:0% + +when you're doing math with significant + + align:start position:0% +when you're doing math with significant + + + align:start position:0% +when you're doing math with significant +figures if you're adding and subtracting + + align:start position:0% +figures if you're adding and subtracting + + + align:start position:0% +figures if you're adding and subtracting +then your final answer should have the + + align:start position:0% +then your final answer should have the + + + align:start position:0% +then your final answer should have the +same + + align:start position:0% +same + + + align:start position:0% +same +number of decimal places as the number + + align:start position:0% +number of decimal places as the number + + + align:start position:0% +number of decimal places as the number +you started with that has the smallest + + align:start position:0% +you started with that has the smallest + + + align:start position:0% +you started with that has the smallest +number of decimal places + + align:start position:0% +number of decimal places + + + align:start position:0% +number of decimal places +when you are multiplying and dividing + + align:start position:0% +when you are multiplying and dividing + + + align:start position:0% +when you are multiplying and dividing +the answer should be rounded to the same + + align:start position:0% +the answer should be rounded to the same + + + align:start position:0% +the answer should be rounded to the same +number of significant figures + + align:start position:0% +number of significant figures + + + align:start position:0% +number of significant figures +as the number you started with that has + + align:start position:0% +as the number you started with that has + + + align:start position:0% +as the number you started with that has +the least number of significant figures + + align:start position:0% +the least number of significant figures + + + align:start position:0% +the least number of significant figures +so when you are multiplying and dividing + + align:start position:0% +so when you are multiplying and dividing + + + align:start position:0% +so when you are multiplying and dividing +you want to count up your sig figs + + align:start position:0% +you want to count up your sig figs + + + align:start position:0% +you want to count up your sig figs +and when you are adding and subtracting + + align:start position:0% +and when you are adding and subtracting + + + align:start position:0% +and when you are adding and subtracting +then you pay attention to + + align:start position:0% +then you pay attention to + + + align:start position:0% +then you pay attention to +your decimal places + + align:start position:0% +your decimal places + + + align:start position:0% +your decimal places +so if we go back to our piece of wood + + align:start position:0% +so if we go back to our piece of wood + + + align:start position:0% +so if we go back to our piece of wood +then using that ruler that we had + + align:start position:0% +then using that ruler that we had + + + align:start position:0% +then using that ruler that we had +earlier + + align:start position:0% +earlier + + + align:start position:0% +earlier +we can estimate maybe + + align:start position:0% +we can estimate maybe + + + align:start position:0% +we can estimate maybe +this is 1.8 so we have gradations every + + align:start position:0% +this is 1.8 so we have gradations every + + + align:start position:0% +this is 1.8 so we have gradations every +one unit we still don't have units + + align:start position:0% +one unit we still don't have units + + + align:start position:0% +one unit we still don't have units +whatever this is + + align:start position:0% +whatever this is + + + align:start position:0% +whatever this is +and then you can estimate this one digit + + align:start position:0% +and then you can estimate this one digit + + + align:start position:0% +and then you can estimate this one digit +past that + + align:start position:0% +past that + + + align:start position:0% +past that +and then our uncertainty is our + + align:start position:0% +and then our uncertainty is our + + + align:start position:0% +and then our uncertainty is our +gradations divided by two so we know + + align:start position:0% +gradations divided by two so we know + + + align:start position:0% +gradations divided by two so we know +that we are within point + + align:start position:0% +that we are within point + + + align:start position:0% +that we are within point +five of the correct answer because we + + align:start position:0% +five of the correct answer because we + + + align:start position:0% +five of the correct answer because we +can estimate that it's in within + + align:start position:0% +can estimate that it's in within + + + align:start position:0% +can estimate that it's in within +this half of our interval + + align:start position:0% +this half of our interval + + + align:start position:0% +this half of our interval +if we add more gradations to our ruler + + align:start position:0% +if we add more gradations to our ruler + + + align:start position:0% +if we add more gradations to our ruler +so if we have markings every 0.1 + + align:start position:0% +so if we have markings every 0.1 + + + align:start position:0% +so if we have markings every 0.1 +still no units then we can say with + + align:start position:0% +still no units then we can say with + + + align:start position:0% +still no units then we can say with +certainty that our + + align:start position:0% +certainty that our + + + align:start position:0% +certainty that our +piece of wood is 1.567 bigger than 1.7 + + align:start position:0% +piece of wood is 1.567 bigger than 1.7 + + + align:start position:0% +piece of wood is 1.567 bigger than 1.7 +and smaller than 1.8 + + align:start position:0% +and smaller than 1.8 + + + align:start position:0% +and smaller than 1.8 +so it's 1.7 something you can estimate + + align:start position:0% +so it's 1.7 something you can estimate + + + align:start position:0% +so it's 1.7 something you can estimate +that last decimal place + + align:start position:0% +that last decimal place + + + align:start position:0% +that last decimal place +and then your error gets smaller too + + align:start position:0% +and then your error gets smaller too + + + align:start position:0% +and then your error gets smaller too +your uncertainty in that measurement + + align:start position:0% + + + + align:start position:0% + +this is important in the lab because you + + align:start position:0% +this is important in the lab because you + + + align:start position:0% +this is important in the lab because you +need to make sure that you're choosing + + align:start position:0% +need to make sure that you're choosing + + + align:start position:0% +need to make sure that you're choosing +the correct + + align:start position:0% +the correct + + + align:start position:0% +the correct +apparatus for the amount of uncertainty + + align:start position:0% +apparatus for the amount of uncertainty + + + align:start position:0% +apparatus for the amount of uncertainty +that you want in your measurement + + align:start position:0% +that you want in your measurement + + + align:start position:0% +that you want in your measurement +so if you see something in your lab + + align:start position:0% +so if you see something in your lab + + + align:start position:0% +so if you see something in your lab +manual that says measure 1.2 grams + + align:start position:0% +manual that says measure 1.2 grams + + + align:start position:0% +manual that says measure 1.2 grams +then this balance is totally fine + + align:start position:0% +then this balance is totally fine + + + align:start position:0% +then this balance is totally fine +because the balance balances + + align:start position:0% +because the balance balances + + + align:start position:0% +because the balance balances +if you've never noticed at the top they + + align:start position:0% +if you've never noticed at the top they + + + align:start position:0% +if you've never noticed at the top they +have the uncertainty written on there so + + align:start position:0% +have the uncertainty written on there so + + + align:start position:0% +have the uncertainty written on there so +the uncertainty is in this last decimal + + align:start position:0% +the uncertainty is in this last decimal + + + align:start position:0% +the uncertainty is in this last decimal +place here + + align:start position:0% +place here + + + align:start position:0% +place here +so if you want 1.2 grams then you can + + align:start position:0% +so if you want 1.2 grams then you can + + + align:start position:0% +so if you want 1.2 grams then you can +get 1.2 and then your last digit is the + + align:start position:0% +get 1.2 and then your last digit is the + + + align:start position:0% +get 1.2 and then your last digit is the +uncertain one + + align:start position:0% +uncertain one + + + align:start position:0% +uncertain one +you should always write down all of the + + align:start position:0% +you should always write down all of the + + + align:start position:0% +you should always write down all of the +digits that are + + align:start position:0% +digits that are + + + align:start position:0% +digits that are +on the balance screen but when you're + + align:start position:0% +on the balance screen but when you're + + + align:start position:0% +on the balance screen but when you're +going to calculate uncertainty + + align:start position:0% +going to calculate uncertainty + + + align:start position:0% +going to calculate uncertainty +or do an error propagation then you know + + align:start position:0% +or do an error propagation then you know + + + align:start position:0% +or do an error propagation then you know +that the last + + align:start position:0% +that the last + + + align:start position:0% +that the last +digit is where your uncertainty is this + + align:start position:0% +digit is where your uncertainty is this + + + align:start position:0% +digit is where your uncertainty is this +is plus or minus 0.01 grams so we have + + align:start position:0% +is plus or minus 0.01 grams so we have + + + align:start position:0% +is plus or minus 0.01 grams so we have +three different types of balances in the + + align:start position:0% +three different types of balances in the + + + align:start position:0% +three different types of balances in the +labs you want to make sure that you're + + align:start position:0% +labs you want to make sure that you're + + + align:start position:0% +labs you want to make sure that you're +choosing the one that has the correct + + align:start position:0% +choosing the one that has the correct + + + align:start position:0% +choosing the one that has the correct +number of decimal places for + + align:start position:0% +number of decimal places for + + + align:start position:0% +number of decimal places for +the quantity that you are trying to + + align:start position:0% +the quantity that you are trying to + + + align:start position:0% +the quantity that you are trying to +measure + + align:start position:0% + + + + align:start position:0% + +and the same thing goes for glassware so + + align:start position:0% +and the same thing goes for glassware so + + + align:start position:0% +and the same thing goes for glassware so +the uncertainty in the glassware is + + align:start position:0% +the uncertainty in the glassware is + + + align:start position:0% +the uncertainty in the glassware is +frequently reported on the glassware + + align:start position:0% +frequently reported on the glassware + + + align:start position:0% +frequently reported on the glassware +itself + + align:start position:0% +itself + + + align:start position:0% +itself +and there are standard tolerances for + + align:start position:0% +and there are standard tolerances for + + + align:start position:0% +and there are standard tolerances for +various sizes and grades of glassware so + + align:start position:0% +various sizes and grades of glassware so + + + align:start position:0% +various sizes and grades of glassware so +if you've ever seen glassware + + align:start position:0% +if you've ever seen glassware + + + align:start position:0% +if you've ever seen glassware +that's volumetric it may say either an a + + align:start position:0% +that's volumetric it may say either an a + + + align:start position:0% +that's volumetric it may say either an a +or a b + + align:start position:0% +or a b + + + align:start position:0% +or a b +on it so the a is like the highest + + align:start position:0% +on it so the a is like the highest + + + align:start position:0% +on it so the a is like the highest +standard and then b + + align:start position:0% +standard and then b + + + align:start position:0% +standard and then b +is a slightly higher tolerance and there + + align:start position:0% +is a slightly higher tolerance and there + + + align:start position:0% +is a slightly higher tolerance and there +are standard things + + align:start position:0% +are standard things + + + align:start position:0% +are standard things +of those that you can look up but it's + + align:start position:0% +of those that you can look up but it's + + + align:start position:0% +of those that you can look up but it's +usually written on the glassware and so + + align:start position:0% +usually written on the glassware and so + + + align:start position:0% +usually written on the glassware and so +this is an example of the 10 milliliter + + align:start position:0% +this is an example of the 10 milliliter + + + align:start position:0% +this is an example of the 10 milliliter +pipet that i was showing you earlier + + align:start position:0% +pipet that i was showing you earlier + + + align:start position:0% +pipet that i was showing you earlier +so you can look at the pipette and then + + align:start position:0% +so you can look at the pipette and then + + + align:start position:0% +so you can look at the pipette and then +on the top part here it'll say 10 + + align:start position:0% +on the top part here it'll say 10 + + + align:start position:0% +on the top part here it'll say 10 +milliliters and this one says plus or + + align:start position:0% +milliliters and this one says plus or + + + align:start position:0% +milliliters and this one says plus or +minus 0.04 + + align:start position:0% +minus 0.04 + + + align:start position:0% +minus 0.04 +this pipet says plus or minus 0.02 so + + align:start position:0% +this pipet says plus or minus 0.02 so + + + align:start position:0% +this pipet says plus or minus 0.02 so +that one's calibrated a little bit more + + align:start position:0% +that one's calibrated a little bit more + + + align:start position:0% +that one's calibrated a little bit more +precisely these are also 10 milliliter + + align:start position:0% +precisely these are also 10 milliliter + + + align:start position:0% +precisely these are also 10 milliliter +pipettes and you can look on + + align:start position:0% +pipettes and you can look on + + + align:start position:0% +pipettes and you can look on +the top part here to figure out what + + align:start position:0% +the top part here to figure out what + + + align:start position:0% +the top part here to figure out what +their tolerance is these are both .06 + + align:start position:0% +their tolerance is these are both .06 + + + align:start position:0% +their tolerance is these are both .06 +and one of the other things that you + + align:start position:0% +and one of the other things that you + + + align:start position:0% +and one of the other things that you +need to make sure when you are using + + align:start position:0% +need to make sure when you are using + + + align:start position:0% +need to make sure when you are using +different types of glassware is to + + align:start position:0% +different types of glassware is to + + + align:start position:0% +different types of glassware is to +figure out where + + align:start position:0% +figure out where + + + align:start position:0% +figure out where +the markings end so these are both 10 + + align:start position:0% +the markings end so these are both 10 + + + align:start position:0% +the markings end so these are both 10 +milliliter pipettes and they are + + align:start position:0% +milliliter pipettes and they are + + + align:start position:0% +milliliter pipettes and they are +designed to measure 10 milliliters + + align:start position:0% +designed to measure 10 milliliters + + + align:start position:0% +designed to measure 10 milliliters +within .06 milliliters + + align:start position:0% +within .06 milliliters + + + align:start position:0% +within .06 milliliters +this one i don't know if you can see it + + align:start position:0% +this one i don't know if you can see it + + + align:start position:0% +this one i don't know if you can see it +from here probably not but the um + + align:start position:0% +from here probably not but the um + + + align:start position:0% +from here probably not but the um +if i hold it up here the markings and + + align:start position:0% +if i hold it up here the markings and + + + align:start position:0% +if i hold it up here the markings and +they go from 0 to 10 and it ends here + + align:start position:0% +they go from 0 to 10 and it ends here + + + align:start position:0% +they go from 0 to 10 and it ends here +and there are no more markings at the + + align:start position:0% +and there are no more markings at the + + + align:start position:0% +and there are no more markings at the +tip + + align:start position:0% +tip + + + align:start position:0% +tip +so that means that the only time you're + + align:start position:0% +so that means that the only time you're + + + align:start position:0% +so that means that the only time you're +measuring something is when your liquid + + align:start position:0% +measuring something is when your liquid + + + align:start position:0% +measuring something is when your liquid +is within where the markings are + + align:start position:0% +is within where the markings are + + + align:start position:0% +is within where the markings are +so if you're going to measure 10 + + align:start position:0% +so if you're going to measure 10 + + + align:start position:0% +so if you're going to measure 10 +milliliters you need to start your + + align:start position:0% +milliliters you need to start your + + + align:start position:0% +milliliters you need to start your +liquid here end it at 10 and don't go + + align:start position:0% +liquid here end it at 10 and don't go + + + align:start position:0% +liquid here end it at 10 and don't go +below that because that + + align:start position:0% +below that because that + + + align:start position:0% +below that because that +quantity is not calibrated + + align:start position:0% +quantity is not calibrated + + + align:start position:0% +quantity is not calibrated +there are some pipettes like this one + + align:start position:0% +there are some pipettes like this one + + + align:start position:0% +there are some pipettes like this one +that are also designed to measure 10 + + align:start position:0% +that are also designed to measure 10 + + + align:start position:0% +that are also designed to measure 10 +milliliters + + align:start position:0% +milliliters + + + align:start position:0% +milliliters +but these have gradations all the way to + + align:start position:0% +but these have gradations all the way to + + + align:start position:0% +but these have gradations all the way to +the end of the pipet + + align:start position:0% +the end of the pipet + + + align:start position:0% +the end of the pipet +so to get 10 milliliters out of this one + + align:start position:0% +so to get 10 milliliters out of this one + + + align:start position:0% +so to get 10 milliliters out of this one +you would fill it up to here + + align:start position:0% +you would fill it up to here + + + align:start position:0% +you would fill it up to here +and then drain it all the way out to the + + align:start position:0% +and then drain it all the way out to the + + + align:start position:0% +and then drain it all the way out to the +bottom so you want to make sure + + align:start position:0% +bottom so you want to make sure + + + align:start position:0% +bottom so you want to make sure +that you check your glassware ahead of + + align:start position:0% +that you check your glassware ahead of + + + align:start position:0% +that you check your glassware ahead of +time to figure out which + + align:start position:0% +time to figure out which + + + align:start position:0% +time to figure out which +how much of it you can use to measure + + align:start position:0% +how much of it you can use to measure + + + align:start position:0% +how much of it you can use to measure +liquids + + align:start position:0% +liquids + + + align:start position:0% +liquids +and what you get if you empty it all the + + align:start position:0% +and what you get if you empty it all the + + + align:start position:0% +and what you get if you empty it all the +way out versus + + align:start position:0% +way out versus + + + align:start position:0% +way out versus +measuring by difference + + align:start position:0% + + + + align:start position:0% + +if you look at your graduated cylinders + + align:start position:0% +if you look at your graduated cylinders + + + align:start position:0% +if you look at your graduated cylinders +your graduated cylinders + + align:start position:0% +your graduated cylinders + + + align:start position:0% +your graduated cylinders +are different sizes and the markings + + align:start position:0% +are different sizes and the markings + + + align:start position:0% +are different sizes and the markings +come + + align:start position:0% +come + + + align:start position:0% +come +in different levels of precision so this + + align:start position:0% +in different levels of precision so this + + + align:start position:0% +in different levels of precision so this +has markings + + align:start position:0% +has markings + + + align:start position:0% +has markings +every half a milliliter and its + + align:start position:0% +every half a milliliter and its + + + align:start position:0% +every half a milliliter and its +tolerance is listed at the top + + align:start position:0% +tolerance is listed at the top + + + align:start position:0% +tolerance is listed at the top +as plus or minus 0.3 + + align:start position:0% +as plus or minus 0.3 + + + align:start position:0% +as plus or minus 0.3 +the 50 milliliter um graduated cylinder + + align:start position:0% +the 50 milliliter um graduated cylinder + + + align:start position:0% +the 50 milliliter um graduated cylinder +has markings every one milliliter + + align:start position:0% +has markings every one milliliter + + + align:start position:0% +has markings every one milliliter +and at the top it'll tell you that its + + align:start position:0% +and at the top it'll tell you that its + + + align:start position:0% +and at the top it'll tell you that its +tolerance is plus or minus 0.5 + + align:start position:0% +tolerance is plus or minus 0.5 + + + align:start position:0% +tolerance is plus or minus 0.5 +milliliters so again just + + align:start position:0% +milliliters so again just + + + align:start position:0% +milliliters so again just +that's the one milliliter divided by two + + align:start position:0% +that's the one milliliter divided by two + + + align:start position:0% +that's the one milliliter divided by two +rule so sometimes that holds and + + align:start position:0% +rule so sometimes that holds and + + + align:start position:0% +rule so sometimes that holds and +sometimes it's a little bit different + + align:start position:0% +sometimes it's a little bit different + + + align:start position:0% +sometimes it's a little bit different +um volumetric glassware always has a + + align:start position:0% +um volumetric glassware always has a + + + align:start position:0% +um volumetric glassware always has a +smaller tolerance so this is to 250 + + align:start position:0% +smaller tolerance so this is to 250 + + + align:start position:0% +smaller tolerance so this is to 250 +milliliter volumetric flask and on here + + align:start position:0% +milliliter volumetric flask and on here + + + align:start position:0% +milliliter volumetric flask and on here +it'll tell you that its tolerance is + + align:start position:0% +it'll tell you that its tolerance is + + + align:start position:0% +it'll tell you that its tolerance is +plus or minus 0.12 + + align:start position:0% +plus or minus 0.12 + + + align:start position:0% +plus or minus 0.12 +so you should always look at these and + + align:start position:0% +so you should always look at these and + + + align:start position:0% +so you should always look at these and +when you are making measurements in the + + align:start position:0% +when you are making measurements in the + + + align:start position:0% +when you are making measurements in the +lab when you're writing things down in + + align:start position:0% +lab when you're writing things down in + + + align:start position:0% +lab when you're writing things down in +your lab manual you should always write + + align:start position:0% +your lab manual you should always write + + + align:start position:0% +your lab manual you should always write +down + + align:start position:0% +down + + + align:start position:0% +down +what the uncertainty in the measurement + + align:start position:0% +what the uncertainty in the measurement + + + align:start position:0% +what the uncertainty in the measurement +that you're making is so whether it's on + + align:start position:0% +that you're making is so whether it's on + + + align:start position:0% +that you're making is so whether it's on +one of the balances or a volume + + align:start position:0% +one of the balances or a volume + + + align:start position:0% +one of the balances or a volume +um always make sure that you write down + + align:start position:0% +um always make sure that you write down + + + align:start position:0% +um always make sure that you write down +what the uncertainty of the glassware + + align:start position:0% +what the uncertainty of the glassware + + + align:start position:0% +what the uncertainty of the glassware +that you're using is + + align:start position:0% +that you're using is + + + align:start position:0% +that you're using is +if you look at something like a beaker + + align:start position:0% +if you look at something like a beaker + + + align:start position:0% +if you look at something like a beaker +this also has a tolerance on it and it's + + align:start position:0% +this also has a tolerance on it and it's + + + align:start position:0% +this also has a tolerance on it and it's +plus or minus five percent + + align:start position:0% +plus or minus five percent + + + align:start position:0% +plus or minus five percent +so that's a lot when you are looking at + + align:start position:0% +so that's a lot when you are looking at + + + align:start position:0% +so that's a lot when you are looking at +a 300 milliliter beaker + + align:start position:0% +a 300 milliliter beaker + + + align:start position:0% +a 300 milliliter beaker +that's going to be a lot more uncertain + + align:start position:0% +that's going to be a lot more uncertain + + + align:start position:0% +that's going to be a lot more uncertain +than any of these other measuring + + align:start position:0% +than any of these other measuring + + + align:start position:0% +than any of these other measuring +implements so it's good to know before + + align:start position:0% +implements so it's good to know before + + + align:start position:0% +implements so it's good to know before +you choose what + + align:start position:0% +you choose what + + + align:start position:0% +you choose what +piece of glassware you're going to use + + align:start position:0% +piece of glassware you're going to use + + + align:start position:0% +piece of glassware you're going to use +to measure something how precise you + + align:start position:0% +to measure something how precise you + + + align:start position:0% +to measure something how precise you +want your answer to be + + align:start position:0% +want your answer to be + + + align:start position:0% +want your answer to be +and how much uncertainty is acceptable + + align:start position:0% +and how much uncertainty is acceptable + + + align:start position:0% +and how much uncertainty is acceptable +in the measurement that you are making + + align:start position:0% +in the measurement that you are making + + + align:start position:0% +in the measurement that you are making +with burettes so this is a + + align:start position:0% +with burettes so this is a + + + align:start position:0% +with burettes so this is a +50 milliliter buret and it doesn't have + + align:start position:0% +50 milliliter buret and it doesn't have + + + align:start position:0% +50 milliliter buret and it doesn't have +a tolerance listed on it but it has + + align:start position:0% +a tolerance listed on it but it has + + + align:start position:0% +a tolerance listed on it but it has +markings every + + align:start position:0% +markings every + + + align:start position:0% +markings every +tenth of a milliliter so what would the + + align:start position:0% +tenth of a milliliter so what would the + + + align:start position:0% +tenth of a milliliter so what would the +uncertainty in a burette be + + align:start position:0% +uncertainty in a burette be + + + align:start position:0% +uncertainty in a burette be +in the spirit + + align:start position:0% + + + + align:start position:0% + +point so if the markings are every + + align:start position:0% +point so if the markings are every + + + align:start position:0% +point so if the markings are every +in a 50 milliliter buret + + align:start position:0% + + + + align:start position:0% + +the markings are every 0.1 milliliters + + align:start position:0% +the markings are every 0.1 milliliters + + + align:start position:0% +the markings are every 0.1 milliliters +so the uncertainty is + + align:start position:0% +so the uncertainty is + + + align:start position:0% +so the uncertainty is +0.05 so plus or minus 0.05 + + align:start position:0% +0.05 so plus or minus 0.05 + + + align:start position:0% +0.05 so plus or minus 0.05 +milliliters + + align:start position:0% + + + + align:start position:0% + +in a 10 milliliter buret + + align:start position:0% +in a 10 milliliter buret + + + align:start position:0% +in a 10 milliliter buret +the markings are every let's see + + align:start position:0% + + + + align:start position:0% + +i think they're every point two point + + align:start position:0% +i think they're every point two point + + + align:start position:0% +i think they're every point two point +no what are these 0.05 + + align:start position:0% +no what are these 0.05 + + + align:start position:0% +no what are these 0.05 +yeah these are every point zero one + + align:start position:0% +yeah these are every point zero one + + + align:start position:0% +yeah these are every point zero one +in a 10 milliliter buret so what would + + align:start position:0% +in a 10 milliliter buret so what would + + + align:start position:0% +in a 10 milliliter buret so what would +the uncertainty be here + + align:start position:0% + + + + align:start position:0% + +so make sure that you are looking at + + align:start position:0% +so make sure that you are looking at + + + align:start position:0% +so make sure that you are looking at +what glassware you're using and you + + align:start position:0% +what glassware you're using and you + + + align:start position:0% +what glassware you're using and you +record the correct number of significant + + align:start position:0% +record the correct number of significant + + + align:start position:0% +record the correct number of significant +figures because it changes based on + + align:start position:0% +figures because it changes based on + + + align:start position:0% +figures because it changes based on +the type of buret and even within + + align:start position:0% +the type of buret and even within + + + align:start position:0% +the type of buret and even within +different types of glass where they are + + align:start position:0% +different types of glass where they are + + + align:start position:0% +different types of glass where they are +made different with varying levels of + + align:start position:0% +made different with varying levels of + + + align:start position:0% +made different with varying levels of +quality + + align:start position:0% + + + + align:start position:0% + +so we can make one measurement and then + + align:start position:0% +so we can make one measurement and then + + + align:start position:0% +so we can make one measurement and then +we can figure out what the uncertainty + + align:start position:0% +we can figure out what the uncertainty + + + align:start position:0% +we can figure out what the uncertainty +is in that one measurement + + align:start position:0% +is in that one measurement + + + align:start position:0% +is in that one measurement +but what happens if we take multiple + + align:start position:0% +but what happens if we take multiple + + + align:start position:0% +but what happens if we take multiple +measurements and have to do math with + + align:start position:0% +measurements and have to do math with + + + align:start position:0% +measurements and have to do math with +them + + align:start position:0% +them + + + align:start position:0% +them +so if you look at your worksheet here + + align:start position:0% +so if you look at your worksheet here + + + align:start position:0% +so if you look at your worksheet here +this is an example of something that you + + align:start position:0% +this is an example of something that you + + + align:start position:0% +this is an example of something that you +might do in the lab where you have + + align:start position:0% +might do in the lab where you have + + + align:start position:0% +might do in the lab where you have +done a series of titrations to calculate + + align:start position:0% +done a series of titrations to calculate + + + align:start position:0% +done a series of titrations to calculate +the concentration of some sort of hcl + + align:start position:0% +the concentration of some sort of hcl + + + align:start position:0% +the concentration of some sort of hcl +solution + + align:start position:0% +solution + + + align:start position:0% +solution +so the first question is what is the + + align:start position:0% +so the first question is what is the + + + align:start position:0% +so the first question is what is the +uncertainty associated with a 50 + + align:start position:0% +uncertainty associated with a 50 + + + align:start position:0% +uncertainty associated with a 50 +milliliter bureau we already figured + + align:start position:0% +milliliter bureau we already figured + + + align:start position:0% +milliliter bureau we already figured +that out + + align:start position:0% +that out + + + align:start position:0% +that out +and then if we were going to calculate + + align:start position:0% +and then if we were going to calculate + + + align:start position:0% +and then if we were going to calculate +the volume dispensed in each + + align:start position:0% +the volume dispensed in each + + + align:start position:0% +the volume dispensed in each +titration trial with the correct error + + align:start position:0% +titration trial with the correct error + + + align:start position:0% +titration trial with the correct error +how would we do that + + align:start position:0% + + + + align:start position:0% + +so one of the ways that you could think + + align:start position:0% +so one of the ways that you could think + + + align:start position:0% +so one of the ways that you could think +about + + align:start position:0% +about + + + align:start position:0% +about +adding up the error in these + + align:start position:0% +adding up the error in these + + + align:start position:0% +adding up the error in these +measurements is + + align:start position:0% +measurements is + + + align:start position:0% +measurements is +just straight up adding the error so if + + align:start position:0% +just straight up adding the error so if + + + align:start position:0% +just straight up adding the error so if +you have for this first example we have + + align:start position:0% +you have for this first example we have + + + align:start position:0% +you have for this first example we have +12.52 milliliters + + align:start position:0% +12.52 milliliters + + + align:start position:0% +12.52 milliliters +this chalk is no good and then + + align:start position:0% +this chalk is no good and then + + + align:start position:0% +this chalk is no good and then +do volume by difference we have 0.24 + + align:start position:0% +do volume by difference we have 0.24 + + + align:start position:0% +do volume by difference we have 0.24 +milliliters + + align:start position:0% +milliliters + + + align:start position:0% +milliliters +and each of these has an uncertainty of + + align:start position:0% +and each of these has an uncertainty of + + + align:start position:0% +and each of these has an uncertainty of +plus or minus 0.05 milliliters + + align:start position:0% + + + + align:start position:0% + +so if we added up the error in these + + align:start position:0% +so if we added up the error in these + + + align:start position:0% +so if we added up the error in these +measurements then we would get + + align:start position:0% +measurements then we would get + + + align:start position:0% +measurements then we would get +0.1 milliliters but it is + + align:start position:0% +0.1 milliliters but it is + + + align:start position:0% +0.1 milliliters but it is +probably pretty unlikely that both of + + align:start position:0% +probably pretty unlikely that both of + + + align:start position:0% +probably pretty unlikely that both of +these measurements were off + + align:start position:0% +these measurements were off + + + align:start position:0% +these measurements were off +by the full .05 milliliters so this + + align:start position:0% +by the full .05 milliliters so this + + + align:start position:0% +by the full .05 milliliters so this +would tend to overestimate the amount of + + align:start position:0% +would tend to overestimate the amount of + + + align:start position:0% +would tend to overestimate the amount of +error in your final answer + + align:start position:0% +error in your final answer + + + align:start position:0% +error in your final answer +so what we do is we propagate the error + + align:start position:0% +so what we do is we propagate the error + + + align:start position:0% +so what we do is we propagate the error +and when you're adding subtracting you + + align:start position:0% +and when you're adding subtracting you + + + align:start position:0% +and when you're adding subtracting you +use the absolute errors because you + + align:start position:0% +use the absolute errors because you + + + align:start position:0% +use the absolute errors because you +should be adding + + align:start position:0% +should be adding + + + align:start position:0% +should be adding +quantities that um have the same units + + align:start position:0% +quantities that um have the same units + + + align:start position:0% +quantities that um have the same units +so units will be consistent throughout + + align:start position:0% +so units will be consistent throughout + + + align:start position:0% +so units will be consistent throughout +your calculation + + align:start position:0% +your calculation + + + align:start position:0% +your calculation +and with this did anybody subtract this + + align:start position:0% +and with this did anybody subtract this + + + align:start position:0% +and with this did anybody subtract this +out + + align:start position:0% +out + + + align:start position:0% +out +all right i've done opinion on this + + align:start position:0% +all right i've done opinion on this + + + align:start position:0% +all right i've done opinion on this +calculator + + align:start position:0% + + + + align:start position:0% + +hopefully yeah great so if we subtract + + align:start position:0% +hopefully yeah great so if we subtract + + + align:start position:0% +hopefully yeah great so if we subtract +these two numbers then we get 12.28 + + align:start position:0% +these two numbers then we get 12.28 + + + align:start position:0% +these two numbers then we get 12.28 +milliliters + + align:start position:0% +milliliters + + + align:start position:0% +milliliters +and then how would we propagate the + + align:start position:0% +and then how would we propagate the + + + align:start position:0% +and then how would we propagate the +error for this calculation + + align:start position:0% + + + + align:start position:0% + +so our error is going to be the square + + align:start position:0% +so our error is going to be the square + + + align:start position:0% +so our error is going to be the square +root + + align:start position:0% +root + + + align:start position:0% +root +of the squares of the errors of each + + align:start position:0% +of the squares of the errors of each + + + align:start position:0% +of the squares of the errors of each +individual measurement so + + align:start position:0% +individual measurement so + + + align:start position:0% +individual measurement so +each one is + + align:start position:0% + + + + align:start position:0% + +so if anyone has done that out or do it + + align:start position:0% +so if anyone has done that out or do it + + + align:start position:0% +so if anyone has done that out or do it +in your head + + align:start position:0% +in your head + + + align:start position:0% +in your head +why not um + + align:start position:0% + + + + align:start position:0% + +the answer that you get is point zero + + align:start position:0% +the answer that you get is point zero + + + align:start position:0% +the answer that you get is point zero +zero seven + + align:start position:0% +zero seven + + + align:start position:0% +zero seven +zero + + align:start position:0% + + + + align:start position:0% + +so that's a lot of extra decimal places + + align:start position:0% +so that's a lot of extra decimal places + + + align:start position:0% +so that's a lot of extra decimal places +and what we really care about + + align:start position:0% +and what we really care about + + + align:start position:0% +and what we really care about +in uncertainty is where is the first + + align:start position:0% +in uncertainty is where is the first + + + align:start position:0% +in uncertainty is where is the first +decimal point that is + + align:start position:0% +decimal point that is + + + align:start position:0% +decimal point that is +uncertain what is that first digit that + + align:start position:0% +uncertain what is that first digit that + + + align:start position:0% +uncertain what is that first digit that +we don't know for sure and so we always + + align:start position:0% +we don't know for sure and so we always + + + align:start position:0% +we don't know for sure and so we always +round + + align:start position:0% +round + + + align:start position:0% +round +an error to the first significant figure + + align:start position:0% +an error to the first significant figure + + + align:start position:0% +an error to the first significant figure +so the error + + align:start position:0% +so the error + + + align:start position:0% +so the error +associated with these measurements is + + align:start position:0% +associated with these measurements is + + + align:start position:0% +associated with these measurements is +just 0.07 + + align:start position:0% + + + + align:start position:0% + +so to write this correctly you would + + align:start position:0% +so to write this correctly you would + + + align:start position:0% +so to write this correctly you would +write it as 12.28 + + align:start position:0% + + + + align:start position:0% + +and you can calculate the volumes for + + align:start position:0% +and you can calculate the volumes for + + + align:start position:0% +and you can calculate the volumes for +each of those trials + + align:start position:0% +each of those trials + + + align:start position:0% +each of those trials +and then the error for all of them is + + align:start position:0% +and then the error for all of them is + + + align:start position:0% +and then the error for all of them is +going to be the same because the error + + align:start position:0% +going to be the same because the error + + + align:start position:0% +going to be the same because the error +for each of your burette measurements + + align:start position:0% +for each of your burette measurements + + + align:start position:0% +for each of your burette measurements +is going to be 0.05 + + align:start position:0% + + + + align:start position:0% + +so then we can talk about what happens + + align:start position:0% +so then we can talk about what happens + + + align:start position:0% +so then we can talk about what happens +to the error in a calculation when you + + align:start position:0% +to the error in a calculation when you + + + align:start position:0% +to the error in a calculation when you +are multiplying or dividing something + + align:start position:0% +are multiplying or dividing something + + + align:start position:0% +are multiplying or dividing something +which is this next part so if you're + + align:start position:0% +which is this next part so if you're + + + align:start position:0% +which is this next part so if you're +going to use this value to calculate the + + align:start position:0% +going to use this value to calculate the + + + align:start position:0% +going to use this value to calculate the +concentration + + align:start position:0% +concentration + + + align:start position:0% +concentration +of the hcl in this fake experiment + + align:start position:0% +of the hcl in this fake experiment + + + align:start position:0% +of the hcl in this fake experiment +then you'll have to do some + + align:start position:0% +then you'll have to do some + + + align:start position:0% +then you'll have to do some +multiplication and division and you'll + + align:start position:0% +multiplication and division and you'll + + + align:start position:0% +multiplication and division and you'll +be using + + align:start position:0% +be using + + + align:start position:0% +be using +different quantities that have different + + align:start position:0% +different quantities that have different + + + align:start position:0% +different quantities that have different +units so you can't just use + + align:start position:0% +units so you can't just use + + + align:start position:0% +units so you can't just use +the absolute error because they have + + align:start position:0% +the absolute error because they have + + + align:start position:0% +the absolute error because they have +different units so if you have + + align:start position:0% +different units so if you have + + + align:start position:0% +different units so if you have +your um error with your buret reading + + align:start position:0% +your um error with your buret reading + + + align:start position:0% +your um error with your buret reading +that'll be in milliliters if you have + + align:start position:0% +that'll be in milliliters if you have + + + align:start position:0% +that'll be in milliliters if you have +your error with your concentration + + align:start position:0% +your error with your concentration + + + align:start position:0% +your error with your concentration +that's in molarity + + align:start position:0% +that's in molarity + + + align:start position:0% +that's in molarity +so we can't use the absolute error so + + align:start position:0% +so we can't use the absolute error so + + + align:start position:0% +so we can't use the absolute error so +we'll have to use the relative error + + align:start position:0% +we'll have to use the relative error + + + align:start position:0% +we'll have to use the relative error +which if you remember + + align:start position:0% +which if you remember + + + align:start position:0% +which if you remember +is the absolute error divided by the + + align:start position:0% +is the absolute error divided by the + + + align:start position:0% +is the absolute error divided by the +measurement that you've made + + align:start position:0% + + + + align:start position:0% + +so you want to take a second and do out + + align:start position:0% +so you want to take a second and do out + + + align:start position:0% +so you want to take a second and do out +that calculation + + align:start position:0% +that calculation + + + align:start position:0% +that calculation +for how to constant calculate the + + align:start position:0% +for how to constant calculate the + + + align:start position:0% +for how to constant calculate the +concentration of the hcl + + align:start position:0% +concentration of the hcl + + + align:start position:0% +concentration of the hcl +then we can + + align:start position:0% + + + + align:start position:0% + +do it all together in a second + + align:start position:0% +do it all together in a second + + + align:start position:0% +do it all together in a second +and we'll just do it for the first trial + + align:start position:0% +and we'll just do it for the first trial + + + align:start position:0% +and we'll just do it for the first trial +and then if you guys want to + + align:start position:0% +and then if you guys want to + + + align:start position:0% +and then if you guys want to +have more practice you can do it for the + + align:start position:0% +have more practice you can do it for the + + + align:start position:0% +have more practice you can do it for the +others afterwards so if we're going to + + align:start position:0% +others afterwards so if we're going to + + + align:start position:0% +others afterwards so if we're going to +set up this calculation for the + + align:start position:0% +set up this calculation for the + + + align:start position:0% +set up this calculation for the +concentration of the hcl solution + + align:start position:0% +concentration of the hcl solution + + + align:start position:0% +concentration of the hcl solution +where would we start + + align:start position:0% + + + + align:start position:0% + +it's the first thing that we have to to + + align:start position:0% +it's the first thing that we have to to + + + align:start position:0% +it's the first thing that we have to to +do or to calculate in this + + align:start position:0% + + + + align:start position:0% + +yeah and what units moles so we can + + align:start position:0% +yeah and what units moles so we can + + + align:start position:0% +yeah and what units moles so we can +figure out how many moles of sodium + + align:start position:0% +figure out how many moles of sodium + + + align:start position:0% +figure out how many moles of sodium +hydroxide we have + + align:start position:0% +hydroxide we have + + + align:start position:0% +hydroxide we have +by taking our volume + + align:start position:0% + + + + align:start position:0% + +and then we have our units our + + align:start position:0% +and then we have our units our + + + align:start position:0% +and then we have our units our +concentration which are in moles per + + align:start position:0% +concentration which are in moles per + + + align:start position:0% +concentration which are in moles per +liter so we need to turn this into + + align:start position:0% + + + + align:start position:0% + +liters + + align:start position:0% +liters + + + align:start position:0% +liters +and then we can use our molarity to get + + align:start position:0% +and then we can use our molarity to get + + + align:start position:0% +and then we can use our molarity to get +moles + + align:start position:0% + + + + align:start position:0% + +i guess we could do that as moles + + align:start position:0% +i guess we could do that as moles + + + align:start position:0% +i guess we could do that as moles +moles of naoh in one liter + + align:start position:0% + + + + align:start position:0% + +then we can go from moles of naoh to + + align:start position:0% +then we can go from moles of naoh to + + + align:start position:0% +then we can go from moles of naoh to +moles of hcl what's our molar ratio + + align:start position:0% + + + + align:start position:0% + +too easy one to one yep + + align:start position:0% + + + + align:start position:0% + +one mole + + align:start position:0% + + + + align:start position:0% + +then we have moles of hcl and then the + + align:start position:0% +then we have moles of hcl and then the + + + align:start position:0% +then we have moles of hcl and then the +last step is to + + align:start position:0% +last step is to + + + align:start position:0% +last step is to +divide by our volume of hcls + + align:start position:0% +divide by our volume of hcls + + + align:start position:0% +divide by our volume of hcls +which in this case is point zero one + + align:start position:0% +which in this case is point zero one + + + align:start position:0% +which in this case is point zero one +zero zero + + align:start position:0% +zero zero + + + align:start position:0% +zero zero +yep liters + + align:start position:0% + + + + align:start position:0% + +that should give you if anybody did it + + align:start position:0% +that should give you if anybody did it + + + align:start position:0% +that should give you if anybody did it +out point zero + + align:start position:0% +out point zero + + + align:start position:0% +out point zero +you molar + + align:start position:0% + + + + align:start position:0% + +hopefully so that's our concentration + + align:start position:0% +hopefully so that's our concentration + + + align:start position:0% +hopefully so that's our concentration +and now we have to figure out what the + + align:start position:0% +and now we have to figure out what the + + + align:start position:0% +and now we have to figure out what the +error associated with that concentration + + align:start position:0% +error associated with that concentration + + + align:start position:0% +error associated with that concentration +is so + + align:start position:0% +is so + + + align:start position:0% +is so +we will look at the error involved in + + align:start position:0% +we will look at the error involved in + + + align:start position:0% +we will look at the error involved in +each of these + + align:start position:0% +each of these + + + align:start position:0% +each of these +terms so we have our air associated with + + align:start position:0% +terms so we have our air associated with + + + align:start position:0% +terms so we have our air associated with +our buret measurement + + align:start position:0% +our buret measurement + + + align:start position:0% +our buret measurement +so our first one is going to be the .07 + + align:start position:0% +so our first one is going to be the .07 + + + align:start position:0% +so our first one is going to be the .07 +over + + align:start position:0% +over + + + align:start position:0% +over +12.2 12.28 + + align:start position:0% +12.2 12.28 + + + align:start position:0% +12.2 12.28 +squared plus what's the next error that + + align:start position:0% +squared plus what's the next error that + + + align:start position:0% +squared plus what's the next error that +we have + + align:start position:0% + + + + align:start position:0% + +which one no say it + + align:start position:0% +which one no say it + + + align:start position:0% +which one no say it +one yeah we have error associated with + + align:start position:0% +one yeah we have error associated with + + + align:start position:0% +one yeah we have error associated with +this measurement right + + align:start position:0% +this measurement right + + + align:start position:0% +this measurement right +and the error associated with that is + + align:start position:0% +and the error associated with that is + + + align:start position:0% +and the error associated with that is +.02 milliliters so you have .02 + + align:start position:0% +.02 milliliters so you have .02 + + + align:start position:0% +.02 milliliters so you have .02 +milliliters over your 10 milliliters + + align:start position:0% + + + + align:start position:0% + +and then what's the last error that we + + align:start position:0% +and then what's the last error that we + + + align:start position:0% +and then what's the last error that we +have + + align:start position:0% + + + + align:start position:0% + +yeah the concentration of naoh the .04 + + align:start position:0% +yeah the concentration of naoh the .04 + + + align:start position:0% +yeah the concentration of naoh the .04 +so you have 0.04 over + + align:start position:0% + + + + align:start position:0% + +0.49 + + align:start position:0% +0.49 + + + align:start position:0% +0.49 +so that's how you will calculate your + + align:start position:0% +so that's how you will calculate your + + + align:start position:0% +so that's how you will calculate your +error + + align:start position:0% +error + + + align:start position:0% +error +for the concentration of the hcl + + align:start position:0% +for the concentration of the hcl + + + align:start position:0% +for the concentration of the hcl +and if you do this out you get + + align:start position:0% + + + + align:start position:0% + +0.08 + + align:start position:0% + + + + align:start position:0% + +so then how would we report these two + + align:start position:0% + + + + align:start position:0% + +together + + align:start position:0% +together + + + align:start position:0% +together +what's the thing from before + + align:start position:0% + + + + align:start position:0% + +so what is this what type of error or + + align:start position:0% +so what is this what type of error or + + + align:start position:0% +so what is this what type of error or +what type of error is this + + align:start position:0% +what type of error is this + + + align:start position:0% +what type of error is this +is an absolute or a relative error + + align:start position:0% + + + + align:start position:0% + +relative so we calculated it from all + + align:start position:0% +relative so we calculated it from all + + + align:start position:0% +relative so we calculated it from all +the relative errors so this is a + + align:start position:0% +the relative errors so this is a + + + align:start position:0% +the relative errors so this is a +relative error and it's also + + align:start position:0% +relative error and it's also + + + align:start position:0% +relative error and it's also +you could think of this as like eight + + align:start position:0% +you could think of this as like eight + + + align:start position:0% +you could think of this as like eight +percent + + align:start position:0% +percent + + + align:start position:0% +percent +so in order to get it back into a + + align:start position:0% +so in order to get it back into a + + + align:start position:0% +so in order to get it back into a +standard error that we can + + align:start position:0% +standard error that we can + + + align:start position:0% +standard error that we can +report with our 6.60172 + + align:start position:0% +report with our 6.60172 + + + align:start position:0% +report with our 6.60172 +then we have to multiply these two + + align:start position:0% +then we have to multiply these two + + + align:start position:0% +then we have to multiply these two +together + + align:start position:0% +together + + + align:start position:0% +together +if we go back to our sig figs from + + align:start position:0% +if we go back to our sig figs from + + + align:start position:0% +if we go back to our sig figs from +before in this calculation how many + + align:start position:0% +before in this calculation how many + + + align:start position:0% +before in this calculation how many +significant figures should our final + + align:start position:0% +significant figures should our final + + + align:start position:0% +significant figures should our final +concentration answer have + + align:start position:0% +concentration answer have + + + align:start position:0% +concentration answer have +two so this has two sig figs so we'll + + align:start position:0% +two so this has two sig figs so we'll + + + align:start position:0% +two so this has two sig figs so we'll +round this to 0.60 + + align:start position:0% +round this to 0.60 + + + align:start position:0% +round this to 0.60 +then you can multiply that by your .08 + + align:start position:0% +then you can multiply that by your .08 + + + align:start position:0% +then you can multiply that by your .08 +relative error and your final answer + + align:start position:0% +relative error and your final answer + + + align:start position:0% +relative error and your final answer +should look something like this + + align:start position:0% +should look something like this + + + align:start position:0% +should look something like this +way down here 0.60 plus or minus .05 + + align:start position:0% +way down here 0.60 plus or minus .05 + + + align:start position:0% +way down here 0.60 plus or minus .05 +molar + + align:start position:0% + + + + align:start position:0% + +any questions about calculating + + align:start position:0% +any questions about calculating + + + align:start position:0% +any questions about calculating +errors and doing error propagation + + align:start position:0% + + + + align:start position:0% + +so this is why it's important to make + + align:start position:0% +so this is why it's important to make + + + align:start position:0% +so this is why it's important to make +sure that you have the correct + + align:start position:0% +sure that you have the correct + + + align:start position:0% +sure that you have the correct +tolerances and the correct errors + + align:start position:0% +tolerances and the correct errors + + + align:start position:0% +tolerances and the correct errors +associated with all of your measurements + + align:start position:0% +associated with all of your measurements + + + align:start position:0% +associated with all of your measurements +because when you go to do all of your + + align:start position:0% +because when you go to do all of your + + + align:start position:0% +because when you go to do all of your +calculations and write your lab report + + align:start position:0% +calculations and write your lab report + + + align:start position:0% +calculations and write your lab report +up + + align:start position:0% +up + + + align:start position:0% +up +it will be very hard to figure out your + + align:start position:0% +it will be very hard to figure out your + + + align:start position:0% +it will be very hard to figure out your +error if you are missing some + + align:start position:0% + + + + align:start position:0% + +okay so now that we know how to deal + + align:start position:0% +okay so now that we know how to deal + + + align:start position:0% +okay so now that we know how to deal +with the various indepen + + align:start position:0% +with the various indepen + + + align:start position:0% +with the various indepen +independent measurements what happens + + align:start position:0% +independent measurements what happens + + + align:start position:0% +independent measurements what happens +when we make the same measurement more + + align:start position:0% +when we make the same measurement more + + + align:start position:0% +when we make the same measurement more +than once + + align:start position:0% +than once + + + align:start position:0% +than once +and this goes back way probably to like + + align:start position:0% +and this goes back way probably to like + + + align:start position:0% +and this goes back way probably to like +middle school when we talk about the + + align:start position:0% +middle school when we talk about the + + + align:start position:0% +middle school when we talk about the +mean or the average of a sample + + align:start position:0% +mean or the average of a sample + + + align:start position:0% +mean or the average of a sample +so in statistics land they call all of + + align:start position:0% +so in statistics land they call all of + + + align:start position:0% +so in statistics land they call all of +the possible values that you could + + align:start position:0% +the possible values that you could + + + align:start position:0% +the possible values that you could +measure + + align:start position:0% +measure + + + align:start position:0% +measure +in of something the population + + align:start position:0% +in of something the population + + + align:start position:0% +in of something the population +and it's really hard to know the true + + align:start position:0% +and it's really hard to know the true + + + align:start position:0% +and it's really hard to know the true +mean of the population unless you have + + align:start position:0% +mean of the population unless you have + + + align:start position:0% +mean of the population unless you have +access to the entire population and + + align:start position:0% +access to the entire population and + + + align:start position:0% +access to the entire population and +you've taken all possible measurements + + align:start position:0% +you've taken all possible measurements + + + align:start position:0% +you've taken all possible measurements +which is pretty much + + align:start position:0% +which is pretty much + + + align:start position:0% +which is pretty much +impossible especially in the case of 5 + + align:start position:0% +impossible especially in the case of 5 + + + align:start position:0% +impossible especially in the case of 5 + + align:start position:0% + + + align:start position:0% +we're not going to be making all of the + + align:start position:0% +we're not going to be making all of the + + + align:start position:0% +we're not going to be making all of the +possible measurements there are for each + + align:start position:0% +possible measurements there are for each + + + align:start position:0% +possible measurements there are for each +quantity that we measure so in the lab + + align:start position:0% +quantity that we measure so in the lab + + + align:start position:0% +quantity that we measure so in the lab +we can take the mean of a subset of the + + align:start position:0% +we can take the mean of a subset of the + + + align:start position:0% +we can take the mean of a subset of the +population we call that the sample and + + align:start position:0% +population we call that the sample and + + + align:start position:0% +population we call that the sample and +then calculate our sample mean + + align:start position:0% +then calculate our sample mean + + + align:start position:0% +then calculate our sample mean +so population mean if you ever see in + + align:start position:0% +so population mean if you ever see in + + + align:start position:0% +so population mean if you ever see in +statistical literature is denoted as mu + + align:start position:0% +statistical literature is denoted as mu + + + align:start position:0% +statistical literature is denoted as mu +and then our sample population is + + align:start position:0% +and then our sample population is + + + align:start position:0% +and then our sample population is +denoted as + + align:start position:0% +denoted as + + + align:start position:0% +denoted as +the x bar where you just add up all of + + align:start position:0% +the x bar where you just add up all of + + + align:start position:0% +the x bar where you just add up all of +your measurements divide by the number + + align:start position:0% +your measurements divide by the number + + + align:start position:0% +your measurements divide by the number +of measurements you took + + align:start position:0% +of measurements you took + + + align:start position:0% +of measurements you took +and that's your mean + + align:start position:0% +and that's your mean + + + align:start position:0% +and that's your mean +so if we calculate an average or a mean + + align:start position:0% +so if we calculate an average or a mean + + + align:start position:0% +so if we calculate an average or a mean +for the + + align:start position:0% +for the + + + align:start position:0% +for the +hcl solution on the back + + align:start position:0% +hcl solution on the back + + + align:start position:0% +hcl solution on the back +if you didn't do the uh + + align:start position:0% +if you didn't do the uh + + + align:start position:0% +if you didn't do the uh +calculations from before your + + align:start position:0% +calculations from before your + + + align:start position:0% +calculations from before your +the concentrations that you should get + + align:start position:0% +the concentrations that you should get + + + align:start position:0% +the concentrations that you should get +are 0.60.61.61 + + align:start position:0% +are 0.60.61.61 + + + align:start position:0% +are 0.60.61.61 +and 0.64 so if you add all those up and + + align:start position:0% +and 0.64 so if you add all those up and + + + align:start position:0% +and 0.64 so if you add all those up and +divide by 5 then your + + align:start position:0% +divide by 5 then your + + + align:start position:0% +divide by 5 then your +mean concentration is 0.615 + + align:start position:0% +mean concentration is 0.615 + + + align:start position:0% +mean concentration is 0.615 +or rounded to the correct number of + + align:start position:0% +or rounded to the correct number of + + + align:start position:0% +or rounded to the correct number of +significant figures 0.6 + + align:start position:0% +significant figures 0.6 + + + align:start position:0% +significant figures 0.6 +2 molar + + align:start position:0% + + + + align:start position:0% + +the other thing that you can calculate + + align:start position:0% +the other thing that you can calculate + + + align:start position:0% +the other thing that you can calculate +is the standard deviation of + + align:start position:0% +is the standard deviation of + + + align:start position:0% +is the standard deviation of +your measurements and so remember that's + + align:start position:0% +your measurements and so remember that's + + + align:start position:0% +your measurements and so remember that's +a measure of precision or how close all + + align:start position:0% +a measure of precision or how close all + + + align:start position:0% +a measure of precision or how close all +of your measurements are to one another + + align:start position:0% +of your measurements are to one another + + + align:start position:0% +of your measurements are to one another +so small standard deviation means that + + align:start position:0% +so small standard deviation means that + + + align:start position:0% +so small standard deviation means that +all of your measurements are very close + + align:start position:0% +all of your measurements are very close + + + align:start position:0% +all of your measurements are very close +together very precise + + align:start position:0% +together very precise + + + align:start position:0% +together very precise +and to calculate the standard deviation + + align:start position:0% +and to calculate the standard deviation + + + align:start position:0% +and to calculate the standard deviation +again you could calculate the standard + + align:start position:0% +again you could calculate the standard + + + align:start position:0% +again you could calculate the standard +deviation of an entire population + + align:start position:0% +deviation of an entire population + + + align:start position:0% +deviation of an entire population +that's the sigma up there and then you + + align:start position:0% +that's the sigma up there and then you + + + align:start position:0% +that's the sigma up there and then you +need to know your population mean + + align:start position:0% +need to know your population mean + + + align:start position:0% +need to know your population mean +but in the lab we are taking a smaller + + align:start position:0% +but in the lab we are taking a smaller + + + align:start position:0% +but in the lab we are taking a smaller +subset of the population so we have to + + align:start position:0% +subset of the population so we have to + + + align:start position:0% +subset of the population so we have to +calculate a sample standard deviation + + align:start position:0% +calculate a sample standard deviation + + + align:start position:0% +calculate a sample standard deviation +which is denoted as + + align:start position:0% +which is denoted as + + + align:start position:0% +which is denoted as +s and the major difference here is that + + align:start position:0% +s and the major difference here is that + + + align:start position:0% +s and the major difference here is that +instead of dividing by + + align:start position:0% +instead of dividing by + + + align:start position:0% +instead of dividing by +n which is the number of samples you + + align:start position:0% +n which is the number of samples you + + + align:start position:0% +n which is the number of samples you +divide by n minus 1. so the number of + + align:start position:0% +divide by n minus 1. so the number of + + + align:start position:0% +divide by n minus 1. so the number of +measurements you took + + align:start position:0% +measurements you took + + + align:start position:0% +measurements you took +minus 1. so to calculate a standard + + align:start position:0% +minus 1. so to calculate a standard + + + align:start position:0% +minus 1. so to calculate a standard +deviation you calculate each of your + + align:start position:0% +deviation you calculate each of your + + + align:start position:0% +deviation you calculate each of your +measurements + + align:start position:0% +measurements + + + align:start position:0% +measurements +subtract it from the sample mean square + + align:start position:0% +subtract it from the sample mean square + + + align:start position:0% +subtract it from the sample mean square +it + + align:start position:0% +it + + + align:start position:0% +it +add those all up divide by n minus 1 and + + align:start position:0% +add those all up divide by n minus 1 and + + + align:start position:0% +add those all up divide by n minus 1 and +then take the square root + + align:start position:0% +then take the square root + + + align:start position:0% +then take the square root +and you can do this on a scientific + + align:start position:0% +and you can do this on a scientific + + + align:start position:0% +and you can do this on a scientific +calculator graphing calculator excel + + align:start position:0% +calculator graphing calculator excel + + + align:start position:0% +calculator graphing calculator excel +does it for you any statistical program + + align:start position:0% +does it for you any statistical program + + + align:start position:0% +does it for you any statistical program +that you want you don't have to + + align:start position:0% +that you want you don't have to + + + align:start position:0% +that you want you don't have to +calculate this by hand + + align:start position:0% +calculate this by hand + + + align:start position:0% +calculate this by hand +in your lab manual or in your lab report + + align:start position:0% +in your lab manual or in your lab report + + + align:start position:0% +in your lab manual or in your lab report +you can just show the formula for it + + align:start position:0% +you can just show the formula for it + + + align:start position:0% +you can just show the formula for it +and then you can calculate it using + + align:start position:0% + + + + align:start position:0% + +any sort of statistical program + + align:start position:0% + + + + align:start position:0% + +so if we calculate the standard + + align:start position:0% +so if we calculate the standard + + + align:start position:0% +so if we calculate the standard +deviation for + + align:start position:0% +deviation for + + + align:start position:0% +deviation for +our concentration of the hcl solution + + align:start position:0% +our concentration of the hcl solution + + + align:start position:0% +our concentration of the hcl solution +then you should get + + align:start position:0% + + + + align:start position:0% + +not going to do this all out by hand + + align:start position:0% +not going to do this all out by hand + + + align:start position:0% +not going to do this all out by hand +right now because we don't have a lot of + + align:start position:0% +right now because we don't have a lot of + + + align:start position:0% +right now because we don't have a lot of +time but if you wanted to try it out + + align:start position:0% +time but if you wanted to try it out + + + align:start position:0% +time but if you wanted to try it out +later + + align:start position:0% +later + + + align:start position:0% +later +or check your answer for somewhere else + + align:start position:0% +or check your answer for somewhere else + + + align:start position:0% +or check your answer for somewhere else +it should be 0.1732 + + align:start position:0% +it should be 0.1732 + + + align:start position:0% +it should be 0.1732 +it keeps going so the standard deviation + + align:start position:0% +it keeps going so the standard deviation + + + align:start position:0% +it keeps going so the standard deviation +is typically rounded to the same number + + align:start position:0% +is typically rounded to the same number + + + align:start position:0% +is typically rounded to the same number +of significant figures as the + + align:start position:0% +of significant figures as the + + + align:start position:0% +of significant figures as the +measurements that you are + + align:start position:0% +measurements that you are + + + align:start position:0% +measurements that you are +using to get the standard deviation + + align:start position:0% +using to get the standard deviation + + + align:start position:0% +using to get the standard deviation +you'll see it reported pretty frequently + + align:start position:0% +you'll see it reported pretty frequently + + + align:start position:0% +you'll see it reported pretty frequently +like that so we can + + align:start position:0% + + + + align:start position:0% + +report our standard deviation as .017 + + align:start position:0% + + + + align:start position:0% + +since we are taking a mean that is not + + align:start position:0% +since we are taking a mean that is not + + + align:start position:0% +since we are taking a mean that is not +the population mean + + align:start position:0% +the population mean + + + align:start position:0% +the population mean +we know that we may not have exactly the + + align:start position:0% +we know that we may not have exactly the + + + align:start position:0% +we know that we may not have exactly the +mean + + align:start position:0% +mean + + + align:start position:0% +mean +of your sample will probably not be + + align:start position:0% +of your sample will probably not be + + + align:start position:0% +of your sample will probably not be +exactly the same as the population mean + + align:start position:0% +exactly the same as the population mean + + + align:start position:0% +exactly the same as the population mean +but you can figure out how good of an + + align:start position:0% +but you can figure out how good of an + + + align:start position:0% +but you can figure out how good of an +estimate your mean is of the + + align:start position:0% +estimate your mean is of the + + + align:start position:0% +estimate your mean is of the +overall population mean by calculating + + align:start position:0% +overall population mean by calculating + + + align:start position:0% +overall population mean by calculating +the standard error of the mean + + align:start position:0% +the standard error of the mean + + + align:start position:0% +the standard error of the mean +and that is done by taking the standard + + align:start position:0% +and that is done by taking the standard + + + align:start position:0% +and that is done by taking the standard +deviation of your sample + + align:start position:0% +deviation of your sample + + + align:start position:0% +deviation of your sample +and dividing by the square root of the + + align:start position:0% +and dividing by the square root of the + + + align:start position:0% +and dividing by the square root of the +number of data points that you have + + align:start position:0% +number of data points that you have + + + align:start position:0% +number of data points that you have +so if you want to get a better and + + align:start position:0% +so if you want to get a better and + + + align:start position:0% +so if you want to get a better and +better estimate of the true mean of your + + align:start position:0% +better estimate of the true mean of your + + + align:start position:0% +better estimate of the true mean of your +population then you can keep increasing + + align:start position:0% +population then you can keep increasing + + + align:start position:0% +population then you can keep increasing +the n value and eventually + + align:start position:0% +the n value and eventually + + + align:start position:0% +the n value and eventually +it'll it'll make your standard error + + align:start position:0% +it'll it'll make your standard error + + + align:start position:0% +it'll it'll make your standard error +smaller to a point since it's the square + + align:start position:0% +smaller to a point since it's the square + + + align:start position:0% +smaller to a point since it's the square +root once you get a big enough number of + + align:start position:0% +root once you get a big enough number of + + + align:start position:0% +root once you get a big enough number of +n then incrementally you get less and + + align:start position:0% +n then incrementally you get less and + + + align:start position:0% +n then incrementally you get less and +less benefit from adding more and more + + align:start position:0% +less benefit from adding more and more + + + align:start position:0% +less benefit from adding more and more +data points + + align:start position:0% +data points + + + align:start position:0% +data points +but you can also make your standard + + align:start position:0% +but you can also make your standard + + + align:start position:0% +but you can also make your standard +error smaller by decreasing your + + align:start position:0% +error smaller by decreasing your + + + align:start position:0% +error smaller by decreasing your +standard deviation + + align:start position:0% +standard deviation + + + align:start position:0% +standard deviation +and so if you can make more precise + + align:start position:0% +and so if you can make more precise + + + align:start position:0% +and so if you can make more precise +measurements then + + align:start position:0% +measurements then + + + align:start position:0% +measurements then +that will also help improve the quality + + align:start position:0% +that will also help improve the quality + + + align:start position:0% +that will also help improve the quality +of your mean + + align:start position:0% +of your mean + + + align:start position:0% +of your mean +and how accurate it is toward the actual + + align:start position:0% +and how accurate it is toward the actual + + + align:start position:0% +and how accurate it is toward the actual +population mean + + align:start position:0% + + + + align:start position:0% + +all of this is kind of leading up to + + align:start position:0% +all of this is kind of leading up to + + + align:start position:0% +all of this is kind of leading up to +doing + + align:start position:0% +doing + + + align:start position:0% +doing +statistics and all of statistics is + + align:start position:0% +statistics and all of statistics is + + + align:start position:0% +statistics and all of statistics is +essentially based on the gaussian + + align:start position:0% +essentially based on the gaussian + + + align:start position:0% +essentially based on the gaussian +distribution or the normal distribution + + align:start position:0% +distribution or the normal distribution + + + align:start position:0% +distribution or the normal distribution +and you've probably seen + + align:start position:0% +and you've probably seen + + + align:start position:0% +and you've probably seen +this before + + align:start position:0% + + + + align:start position:0% + +and this graph is an axis of where the + + align:start position:0% +and this graph is an axis of where the + + + align:start position:0% +and this graph is an axis of where the +x-axis is the number of standard + + align:start position:0% +x-axis is the number of standard + + + align:start position:0% +x-axis is the number of standard +deviations + + align:start position:0% +deviations + + + align:start position:0% +deviations +away from the mean and then the y is the + + align:start position:0% +away from the mean and then the y is the + + + align:start position:0% +away from the mean and then the y is the +probability of finding a measurement + + align:start position:0% +probability of finding a measurement + + + align:start position:0% +probability of finding a measurement +in that space so you can see that the + + align:start position:0% +in that space so you can see that the + + + align:start position:0% +in that space so you can see that the +highest probability of all of your + + align:start position:0% +highest probability of all of your + + + align:start position:0% +highest probability of all of your +measurements is going to be very close + + align:start position:0% +measurements is going to be very close + + + align:start position:0% +measurements is going to be very close +to the mean so if you're taking + + align:start position:0% +to the mean so if you're taking + + + align:start position:0% +to the mean so if you're taking +measurements accurately they should be + + align:start position:0% +measurements accurately they should be + + + align:start position:0% +measurements accurately they should be +very close to the mean and then as you + + align:start position:0% +very close to the mean and then as you + + + align:start position:0% +very close to the mean and then as you +get further and further away there's + + align:start position:0% +get further and further away there's + + + align:start position:0% +get further and further away there's +less probability that some measurement + + align:start position:0% +less probability that some measurement + + + align:start position:0% +less probability that some measurement +you take will be three standard + + align:start position:0% +you take will be three standard + + + align:start position:0% +you take will be three standard +deviations away from the mean and so on + + align:start position:0% +deviations away from the mean and so on + + + align:start position:0% +deviations away from the mean and so on +so this number z is calculated by + + align:start position:0% +so this number z is calculated by + + + align:start position:0% +so this number z is calculated by +subtracting your number from the mean + + align:start position:0% +subtracting your number from the mean + + + align:start position:0% +subtracting your number from the mean +and dividing by the number of standard + + align:start position:0% +and dividing by the number of standard + + + align:start position:0% +and dividing by the number of standard +deviations so it's just essentially + + align:start position:0% +deviations so it's just essentially + + + align:start position:0% +deviations so it's just essentially +the number of standard deviations away + + align:start position:0% +the number of standard deviations away + + + align:start position:0% +the number of standard deviations away +from the mean your measurement + + align:start position:0% +from the mean your measurement + + + align:start position:0% +from the mean your measurement +is + + align:start position:0% + + + + align:start position:0% + +oh back up we cannot go back + + align:start position:0% +oh back up we cannot go back + + + align:start position:0% +oh back up we cannot go back +there we go one way that we can use this + + align:start position:0% +there we go one way that we can use this + + + align:start position:0% +there we go one way that we can use this +is to figure out confidence levels of + + align:start position:0% +is to figure out confidence levels of + + + align:start position:0% +is to figure out confidence levels of +the measurements that we take or the + + align:start position:0% +the measurements that we take or the + + + align:start position:0% +the measurements that we take or the +means that we calculate + + align:start position:0% +means that we calculate + + + align:start position:0% +means that we calculate +and so you can + + align:start position:0% +and so you can + + + align:start position:0% +and so you can +kind of do an error under the curve + + align:start position:0% +kind of do an error under the curve + + + align:start position:0% +kind of do an error under the curve +analysis here or an area under the curve + + align:start position:0% +analysis here or an area under the curve + + + align:start position:0% +analysis here or an area under the curve +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +and so for all measurements that are + + align:start position:0% +and so for all measurements that are + + + align:start position:0% +and so for all measurements that are +within one standard deviation plus or + + align:start position:0% +within one standard deviation plus or + + + align:start position:0% +within one standard deviation plus or +minus from the mean + + align:start position:0% +minus from the mean + + + align:start position:0% +minus from the mean +that accounts for 68 of + + align:start position:0% +that accounts for 68 of + + + align:start position:0% +that accounts for 68 of +the area there if you go within two + + align:start position:0% +the area there if you go within two + + + align:start position:0% +the area there if you go within two +standard deviations + + align:start position:0% +standard deviations + + + align:start position:0% +standard deviations +you can say with a 95 percent confidence + + align:start position:0% +you can say with a 95 percent confidence + + + align:start position:0% +you can say with a 95 percent confidence +that your mean is within + + align:start position:0% +that your mean is within + + + align:start position:0% +that your mean is within +that area and then within three standard + + align:start position:0% +that area and then within three standard + + + align:start position:0% +that area and then within three standard +deviations plus or minus there's a 99 + + align:start position:0% +deviations plus or minus there's a 99 + + + align:start position:0% +deviations plus or minus there's a 99 +chance that your mean is within that + + align:start position:0% +chance that your mean is within that + + + align:start position:0% +chance that your mean is within that +area + + align:start position:0% +area + + + align:start position:0% +area +so we can use this when we are + + align:start position:0% +so we can use this when we are + + + align:start position:0% +so we can use this when we are +calculating + + align:start position:0% +calculating + + + align:start position:0% +calculating +the accuracy or how confident we are + + align:start position:0% +the accuracy or how confident we are + + + align:start position:0% +the accuracy or how confident we are +that we have measured + + align:start position:0% +that we have measured + + + align:start position:0% +that we have measured +the population mean with the samples + + align:start position:0% +the population mean with the samples + + + align:start position:0% +the population mean with the samples +that we have taken in the lab + + align:start position:0% +that we have taken in the lab + + + align:start position:0% +that we have taken in the lab +we can do this because of the central + + align:start position:0% +we can do this because of the central + + + align:start position:0% +we can do this because of the central +limit theorem which states that the + + align:start position:0% +limit theorem which states that the + + + align:start position:0% +limit theorem which states that the +distribution of sample means in a + + align:start position:0% +distribution of sample means in a + + + align:start position:0% +distribution of sample means in a +population will constitute a normal + + align:start position:0% +population will constitute a normal + + + align:start position:0% +population will constitute a normal +distribution even if the population + + align:start position:0% +distribution even if the population + + + align:start position:0% +distribution even if the population +itself is not normally distributed + + align:start position:0% +itself is not normally distributed + + + align:start position:0% +itself is not normally distributed +so if you take a bunch of samples or + + align:start position:0% +so if you take a bunch of samples or + + + align:start position:0% +so if you take a bunch of samples or +take a bunch of measurements in the lab + + align:start position:0% +take a bunch of measurements in the lab + + + align:start position:0% +take a bunch of measurements in the lab +then you can use the normal distribution + + align:start position:0% +then you can use the normal distribution + + + align:start position:0% +then you can use the normal distribution +to + + align:start position:0% +to + + + align:start position:0% +to +statistically analyze them even if you + + align:start position:0% +statistically analyze them even if you + + + align:start position:0% +statistically analyze them even if you +don't know the distribution of the + + align:start position:0% +don't know the distribution of the + + + align:start position:0% +don't know the distribution of the +population + + align:start position:0% +population + + + align:start position:0% +population +itself + + align:start position:0% + + + + align:start position:0% + +so we can use that information to + + align:start position:0% +so we can use that information to + + + align:start position:0% +so we can use that information to +calculate confidence levels of + + align:start position:0% +calculate confidence levels of + + + align:start position:0% +calculate confidence levels of +a mean that we calculate so + + align:start position:0% + + + + align:start position:0% + +what that means is we can calculate how + + align:start position:0% +what that means is we can calculate how + + + align:start position:0% +what that means is we can calculate how +confident we are that our mean + + align:start position:0% +confident we are that our mean + + + align:start position:0% +confident we are that our mean +falls within a certain range of + + align:start position:0% +falls within a certain range of + + + align:start position:0% +falls within a certain range of +the actual population mean and you can + + align:start position:0% +the actual population mean and you can + + + align:start position:0% +the actual population mean and you can +say it with different levels of + + align:start position:0% +say it with different levels of + + + align:start position:0% +say it with different levels of +confidence you can say i'm 99 + + align:start position:0% +confidence you can say i'm 99 + + + align:start position:0% +confidence you can say i'm 99 +confident and you'll get a wider range + + align:start position:0% +confident and you'll get a wider range + + + align:start position:0% +confident and you'll get a wider range +or 95 confident you'll get a little bit + + align:start position:0% +or 95 confident you'll get a little bit + + + align:start position:0% +or 95 confident you'll get a little bit +of a smaller range + + align:start position:0% +of a smaller range + + + align:start position:0% +of a smaller range +and the range of the values is what we + + align:start position:0% +and the range of the values is what we + + + align:start position:0% +and the range of the values is what we +call the confidence interval + + align:start position:0% +call the confidence interval + + + align:start position:0% +call the confidence interval +and you can calculate a confidence + + align:start position:0% +and you can calculate a confidence + + + align:start position:0% +and you can calculate a confidence +interval for the actual population mean + + align:start position:0% +interval for the actual population mean + + + align:start position:0% +interval for the actual population mean +and that is your standard mean + + align:start position:0% +and that is your standard mean + + + align:start position:0% +and that is your standard mean +that z-score that we were talking about + + align:start position:0% +that z-score that we were talking about + + + align:start position:0% +that z-score that we were talking about +times the standard deviation of the + + align:start position:0% +times the standard deviation of the + + + align:start position:0% +times the standard deviation of the +population divided by the square root of + + align:start position:0% +population divided by the square root of + + + align:start position:0% +population divided by the square root of +n + + align:start position:0% + + + + align:start position:0% + +to use z as in the previous slide you + + align:start position:0% +to use z as in the previous slide you + + + align:start position:0% +to use z as in the previous slide you +need to have a big enough sample size + + align:start position:0% +need to have a big enough sample size + + + align:start position:0% +need to have a big enough sample size +that your + + align:start position:0% +that your + + + align:start position:0% +that your +estimates of the mean and the standard + + align:start position:0% +estimates of the mean and the standard + + + align:start position:0% +estimates of the mean and the standard +deviation are + + align:start position:0% +deviation are + + + align:start position:0% +deviation are +a good enough substitute for the actual + + align:start position:0% +a good enough substitute for the actual + + + align:start position:0% +a good enough substitute for the actual +sigma the population standard deviation + + align:start position:0% +sigma the population standard deviation + + + align:start position:0% +sigma the population standard deviation +that's really challenging in lab + + align:start position:0% +that's really challenging in lab + + + align:start position:0% +that's really challenging in lab +situations and in 5 310 we will not ever + + align:start position:0% +situations and in 5 310 we will not ever + + + align:start position:0% +situations and in 5 310 we will not ever +have a big enough sample size for that + + align:start position:0% +have a big enough sample size for that + + + align:start position:0% +have a big enough sample size for that +to be the case + + align:start position:0% +to be the case + + + align:start position:0% +to be the case +so as an alternative we can use the t + + align:start position:0% +so as an alternative we can use the t + + + align:start position:0% +so as an alternative we can use the t +statistic + + align:start position:0% +statistic + + + align:start position:0% +statistic +so to confident calculate a confidence + + align:start position:0% +so to confident calculate a confidence + + + align:start position:0% +so to confident calculate a confidence +interval + + align:start position:0% +interval + + + align:start position:0% +interval +for a mean that you calculate in lab you + + align:start position:0% +for a mean that you calculate in lab you + + + align:start position:0% +for a mean that you calculate in lab you +can take your + + align:start position:0% +can take your + + + align:start position:0% +can take your +mean plus or minus the t statistic times + + align:start position:0% +mean plus or minus the t statistic times + + + align:start position:0% +mean plus or minus the t statistic times +your sample standard deviation over the + + align:start position:0% +your sample standard deviation over the + + + align:start position:0% +your sample standard deviation over the +square root of n + + align:start position:0% +square root of n + + + align:start position:0% +square root of n +and you can calculate t statistics using + + align:start position:0% +and you can calculate t statistics using + + + align:start position:0% +and you can calculate t statistics using +this formula if you have all of this + + align:start position:0% +this formula if you have all of this + + + align:start position:0% +this formula if you have all of this +information or + + align:start position:0% +information or + + + align:start position:0% +information or +you can get a table of t values for + + align:start position:0% +you can get a table of t values for + + + align:start position:0% +you can get a table of t values for +varying confidence + + align:start position:0% +varying confidence + + + align:start position:0% +varying confidence +levels and varying degrees of freedom + + align:start position:0% +levels and varying degrees of freedom + + + align:start position:0% +levels and varying degrees of freedom +which is n + + align:start position:0% +which is n + + + align:start position:0% +which is n +minus one which is um so your + + align:start position:0% +minus one which is um so your + + + align:start position:0% +minus one which is um so your +the number of measurements that you took + + align:start position:0% +the number of measurements that you took + + + align:start position:0% +the number of measurements that you took +minus one + + align:start position:0% +minus one + + + align:start position:0% +minus one +so if we're going to calculate a + + align:start position:0% +so if we're going to calculate a + + + align:start position:0% +so if we're going to calculate a +confidence interval for the mean of our + + align:start position:0% +confidence interval for the mean of our + + + align:start position:0% +confidence interval for the mean of our +hcl concentration then + + align:start position:0% +hcl concentration then + + + align:start position:0% +hcl concentration then +we'll have something like + + align:start position:0% +we'll have something like + + + align:start position:0% +we'll have something like +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +we need our average plus or minus t + + align:start position:0% +we need our average plus or minus t + + + align:start position:0% +we need our average plus or minus t +s square root of n and you'll notice + + align:start position:0% +s square root of n and you'll notice + + + align:start position:0% +s square root of n and you'll notice +that this + + align:start position:0% +that this + + + align:start position:0% +that this +standard deviation over the square root + + align:start position:0% +standard deviation over the square root + + + align:start position:0% +standard deviation over the square root +of n is the standard error of the mean + + align:start position:0% +of n is the standard error of the mean + + + align:start position:0% +of n is the standard error of the mean +so if you calculate that then + + align:start position:0% +so if you calculate that then + + + align:start position:0% +so if you calculate that then +it'll make it slightly easier to + + align:start position:0% +it'll make it slightly easier to + + + align:start position:0% +it'll make it slightly easier to +calculate your confidence interval + + align:start position:0% +calculate your confidence interval + + + align:start position:0% +calculate your confidence interval +um yeah + + align:start position:0% +um yeah + + + align:start position:0% +um yeah +and so to do that we're going to need + + align:start position:0% +and so to do that we're going to need + + + align:start position:0% +and so to do that we're going to need +some sort of t table which gives you the + + align:start position:0% +some sort of t table which gives you the + + + align:start position:0% +some sort of t table which gives you the +t + + align:start position:0% +t + + + align:start position:0% +t +statistics our average of + + align:start position:0% +statistics our average of + + + align:start position:0% +statistics our average of +the mean was 0.62 plus or minus + + align:start position:0% +the mean was 0.62 plus or minus + + + align:start position:0% +the mean was 0.62 plus or minus +so the t value if we have four + + align:start position:0% +so the t value if we have four + + + align:start position:0% +so the t value if we have four +measurements then our + + align:start position:0% +measurements then our + + + align:start position:0% +measurements then our +degrees of freedom is gonna be three so + + align:start position:0% +degrees of freedom is gonna be three so + + + align:start position:0% +degrees of freedom is gonna be three so +n minus one + + align:start position:0% +n minus one + + + align:start position:0% +n minus one +and then we wanna use a two-tailed + + align:start position:0% +and then we wanna use a two-tailed + + + align:start position:0% +and then we wanna use a two-tailed +t-test because we don't know + + align:start position:0% +t-test because we don't know + + + align:start position:0% +t-test because we don't know +which way our measurement is going to + + align:start position:0% +which way our measurement is going to + + + align:start position:0% +which way our measurement is going to +vary so the two-tail means that it could + + align:start position:0% +vary so the two-tail means that it could + + + align:start position:0% +vary so the two-tail means that it could +be higher + + align:start position:0% +be higher + + + align:start position:0% +be higher +or lower than the actual mean so you + + align:start position:0% +or lower than the actual mean so you + + + align:start position:0% +or lower than the actual mean so you +want to calculate one that has + + align:start position:0% +want to calculate one that has + + + align:start position:0% +want to calculate one that has +a value of 0.05 so that'll be + + align:start position:0% +a value of 0.05 so that'll be + + + align:start position:0% +a value of 0.05 so that'll be +corresponds to the 95 percent confidence + + align:start position:0% +corresponds to the 95 percent confidence + + + align:start position:0% +corresponds to the 95 percent confidence +interval + + align:start position:0% +interval + + + align:start position:0% +interval +and 3 so it's 3.182 is our t value + + align:start position:0% + + + + align:start position:0% + +and then times 0.016 + + align:start position:0% + + + + align:start position:0% + +and what you get if you do that out is + + align:start position:0% +and what you get if you do that out is + + + align:start position:0% +and what you get if you do that out is +so when you're going to report your 95 + + align:start position:0% +so when you're going to report your 95 + + + align:start position:0% +so when you're going to report your 95 +confidence interval you would + + align:start position:0% +confidence interval you would + + + align:start position:0% +confidence interval you would +add this number and subtract this number + + align:start position:0% +add this number and subtract this number + + + align:start position:0% +add this number and subtract this number +from your mean and then report it as a + + align:start position:0% +from your mean and then report it as a + + + align:start position:0% +from your mean and then report it as a +range in parentheses + + align:start position:0% +range in parentheses + + + align:start position:0% +range in parentheses +so 0.59 + + align:start position:0% +so 0.59 + + + align:start position:0% +so 0.59 +three comma zero point six four + + align:start position:0% +three comma zero point six four + + + align:start position:0% +three comma zero point six four +seven and so that's your 95 percent + + align:start position:0% +seven and so that's your 95 percent + + + align:start position:0% +seven and so that's your 95 percent +confidence interval + + align:start position:0% +confidence interval + + + align:start position:0% +confidence interval +and so what that's saying is that there + + align:start position:0% +and so what that's saying is that there + + + align:start position:0% +and so what that's saying is that there +is a 95 chance that the actual + + align:start position:0% +is a 95 chance that the actual + + + align:start position:0% +is a 95 chance that the actual +population mean + + align:start position:0% +population mean + + + align:start position:0% +population mean +lies between these two numbers you're 95 + + align:start position:0% +lies between these two numbers you're 95 + + + align:start position:0% +lies between these two numbers you're 95 +sure that the actual mean + + align:start position:0% +sure that the actual mean + + + align:start position:0% +sure that the actual mean +is in there + + align:start position:0% + + + + align:start position:0% + +so in your lab reports when it says to + + align:start position:0% +so in your lab reports when it says to + + + align:start position:0% +so in your lab reports when it says to +calculate a 95 confidence interval + + align:start position:0% +calculate a 95 confidence interval + + + align:start position:0% +calculate a 95 confidence interval +that is what we are looking for + + align:start position:0% + + + + align:start position:0% + +other issues you may run across in your + + align:start position:0% +other issues you may run across in your + + + align:start position:0% +other issues you may run across in your +data is if you take + + align:start position:0% +data is if you take + + + align:start position:0% +data is if you take +repeated measurements of the same + + align:start position:0% +repeated measurements of the same + + + align:start position:0% +repeated measurements of the same +quantity you may have + + align:start position:0% +quantity you may have + + + align:start position:0% +quantity you may have +outliers and sometimes you can look at + + align:start position:0% +outliers and sometimes you can look at + + + align:start position:0% +outliers and sometimes you can look at +your data and say wow there's definitely + + align:start position:0% +your data and say wow there's definitely + + + align:start position:0% +your data and say wow there's definitely +an outlier here and other times + + align:start position:0% +an outlier here and other times + + + align:start position:0% +an outlier here and other times +but even if you can do that it's nice to + + align:start position:0% +but even if you can do that it's nice to + + + align:start position:0% +but even if you can do that it's nice to +be able to mathematically demonstrate + + align:start position:0% +be able to mathematically demonstrate + + + align:start position:0% +be able to mathematically demonstrate +that it is in fact an outlier + + align:start position:0% +that it is in fact an outlier + + + align:start position:0% +that it is in fact an outlier +and so to avoid subjectivity in whether + + align:start position:0% +and so to avoid subjectivity in whether + + + align:start position:0% +and so to avoid subjectivity in whether +you're tossing out data points left or + + align:start position:0% +you're tossing out data points left or + + + align:start position:0% +you're tossing out data points left or +right just to make your stuff look + + align:start position:0% +right just to make your stuff look + + + align:start position:0% +right just to make your stuff look +better + + align:start position:0% +better + + + align:start position:0% +better +you can use the q test to help decide + + align:start position:0% +you can use the q test to help decide + + + align:start position:0% +you can use the q test to help decide +whether a value can be kept in a data + + align:start position:0% +whether a value can be kept in a data + + + align:start position:0% +whether a value can be kept in a data +set or should be rejected as an outlier + + align:start position:0% +set or should be rejected as an outlier + + + align:start position:0% +set or should be rejected as an outlier +and the way the q test works is you take + + align:start position:0% +and the way the q test works is you take + + + align:start position:0% +and the way the q test works is you take +the absolute value of + + align:start position:0% +the absolute value of + + + align:start position:0% +the absolute value of +the result that you're worried about the + + align:start position:0% +the result that you're worried about the + + + align:start position:0% +the result that you're worried about the +questionable value + + align:start position:0% +questionable value + + + align:start position:0% +questionable value +subtract it from its nearest neighbor so + + align:start position:0% +subtract it from its nearest neighbor so + + + align:start position:0% +subtract it from its nearest neighbor so +whatever the next closest value that you + + align:start position:0% +whatever the next closest value that you + + + align:start position:0% +whatever the next closest value that you +measured was + + align:start position:0% +measured was + + + align:start position:0% +measured was +and then divide it by the spread of the + + align:start position:0% +and then divide it by the spread of the + + + align:start position:0% +and then divide it by the spread of the +data which is just your highest value + + align:start position:0% +data which is just your highest value + + + align:start position:0% +data which is just your highest value +that you measured minus your lowest + + align:start position:0% +that you measured minus your lowest + + + align:start position:0% +that you measured minus your lowest +value that you measured + + align:start position:0% +value that you measured + + + align:start position:0% +value that you measured +and then you have to look at another + + align:start position:0% +and then you have to look at another + + + align:start position:0% +and then you have to look at another +table of standardized q values + + align:start position:0% +table of standardized q values + + + align:start position:0% +table of standardized q values +and if the queue that you calculate is + + align:start position:0% +and if the queue that you calculate is + + + align:start position:0% +and if the queue that you calculate is +greater than the q + + align:start position:0% +greater than the q + + + align:start position:0% +greater than the q +in the table for the number of data + + align:start position:0% +in the table for the number of data + + + align:start position:0% +in the table for the number of data +points in the confidence level that you + + align:start position:0% +points in the confidence level that you + + + align:start position:0% +points in the confidence level that you +want + + align:start position:0% +want + + + align:start position:0% +want +then you can reject that point as an + + align:start position:0% +then you can reject that point as an + + + align:start position:0% +then you can reject that point as an +outlier at that confidence level + + align:start position:0% +outlier at that confidence level + + + align:start position:0% +outlier at that confidence level +so the last question on here is not + + align:start position:0% +so the last question on here is not + + + align:start position:0% +so the last question on here is not +really related to the first + + align:start position:0% +really related to the first + + + align:start position:0% +really related to the first +whole set of problems but if you took + + align:start position:0% +whole set of problems but if you took + + + align:start position:0% +whole set of problems but if you took +the following measurements for a + + align:start position:0% +the following measurements for a + + + align:start position:0% +the following measurements for a +concentration of an naoh solution are + + align:start position:0% +concentration of an naoh solution are + + + align:start position:0% +concentration of an naoh solution are +there any outliers in that data set + + align:start position:0% + + + + align:start position:0% + +so what's our q calculation for this + + align:start position:0% +so what's our q calculation for this + + + align:start position:0% +so what's our q calculation for this +data set + + align:start position:0% + + + + align:start position:0% + +which result might be questionable + + align:start position:0% + + + + align:start position:0% + +2.86 yeah that seems to be a little bit + + align:start position:0% +2.86 yeah that seems to be a little bit + + + align:start position:0% +2.86 yeah that seems to be a little bit +higher than everybody else + + align:start position:0% +higher than everybody else + + + align:start position:0% +higher than everybody else +so our questionable result is 2.86 minus + + align:start position:0% + + + + align:start position:0% + +2.52 is its next closest neighbor + + align:start position:0% +2.52 is its next closest neighbor + + + align:start position:0% +2.52 is its next closest neighbor +divided by + + align:start position:0% +divided by + + + align:start position:0% +divided by +how do we calculate the spread of our + + align:start position:0% +how do we calculate the spread of our + + + align:start position:0% +how do we calculate the spread of our +data + + align:start position:0% + + + + align:start position:0% + +so 2.86 which is our max and our minimum + + align:start position:0% +so 2.86 which is our max and our minimum + + + align:start position:0% +so 2.86 which is our max and our minimum +is 2.38 + + align:start position:0% +is 2.38 + + + align:start position:0% +is 2.38 +so if you do that out you get .34 + + align:start position:0% +so if you do that out you get .34 + + + align:start position:0% +so if you do that out you get .34 +divided by + + align:start position:0% +divided by + + + align:start position:0% +divided by +0.48 + + align:start position:0% + + + + align:start position:0% + +so our q value is 0.708 + + align:start position:0% +so our q value is 0.708 + + + align:start position:0% +so our q value is 0.708 +now if we look at a table of values for + + align:start position:0% +now if we look at a table of values for + + + align:start position:0% +now if we look at a table of values for +our q test so we can either calculate it + + align:start position:0% +our q test so we can either calculate it + + + align:start position:0% +our q test so we can either calculate it +at 90 confident that it's an outlier + + align:start position:0% +at 90 confident that it's an outlier + + + align:start position:0% +at 90 confident that it's an outlier +95 confident that it's an outlier and + + align:start position:0% +95 confident that it's an outlier and + + + align:start position:0% +95 confident that it's an outlier and +all the way down + + align:start position:0% +all the way down + + + align:start position:0% +all the way down +um so if we wanted to calculate a 95 + + align:start position:0% +um so if we wanted to calculate a 95 + + + align:start position:0% +um so if we wanted to calculate a 95 +confidence level + + align:start position:0% +confidence level + + + align:start position:0% +confidence level +that this point is an outlier then + + align:start position:0% +that this point is an outlier then + + + align:start position:0% +that this point is an outlier then +we had how many data points in this data + + align:start position:0% +we had how many data points in this data + + + align:start position:0% +we had how many data points in this data +set + + align:start position:0% +set + + + align:start position:0% +set +six so we look at six ninety-five + + align:start position:0% +six so we look at six ninety-five + + + align:start position:0% +six so we look at six ninety-five +percent our q value + + align:start position:0% +percent our q value + + + align:start position:0% +percent our q value +is 0.625 so 0.708 + + align:start position:0% +is 0.625 so 0.708 + + + align:start position:0% +is 0.625 so 0.708 +is greater than 0.625 + + align:start position:0% + + + + align:start position:0% + +so is it an outlier or not + + align:start position:0% + + + + align:start position:0% + +the queue that you calculate is bigger + + align:start position:0% +the queue that you calculate is bigger + + + align:start position:0% +the queue that you calculate is bigger +than the queue in the table then it is + + align:start position:0% +than the queue in the table then it is + + + align:start position:0% +than the queue in the table then it is +indeed an outlier and + + align:start position:0% +indeed an outlier and + + + align:start position:0% +indeed an outlier and +we can confidently say that that does + + align:start position:0% +we can confidently say that that does + + + align:start position:0% +we can confidently say that that does +not belong in our data set + + align:start position:0% + + + + align:start position:0% + +we're working on it come on + + align:start position:0% + + + + align:start position:0% + +so you can see that if anything had + + align:start position:0% +so you can see that if anything had + + + align:start position:0% +so you can see that if anything had +changed like if we had had fewer data + + align:start position:0% +changed like if we had had fewer data + + + align:start position:0% +changed like if we had had fewer data +points then + + align:start position:0% +points then + + + align:start position:0% +points then +it would not be an outlier or if you + + align:start position:0% +it would not be an outlier or if you + + + align:start position:0% +it would not be an outlier or if you +wanted a higher confidence level then it + + align:start position:0% +wanted a higher confidence level then it + + + align:start position:0% +wanted a higher confidence level then it +also + + align:start position:0% +also + + + align:start position:0% +also +would not have been an outlier so it's a + + align:start position:0% +would not have been an outlier so it's a + + + align:start position:0% +would not have been an outlier so it's a +little more strict how far away from the + + align:start position:0% +little more strict how far away from the + + + align:start position:0% +little more strict how far away from the +rest of the points it has to be before + + align:start position:0% +rest of the points it has to be before + + + align:start position:0% +rest of the points it has to be before +you can call it an outlier + + align:start position:0% + + + + align:start position:0% + +the last thing we're going to talk about + + align:start position:0% +the last thing we're going to talk about + + + align:start position:0% +the last thing we're going to talk about +is doing the least squares regression + + align:start position:0% +is doing the least squares regression + + + align:start position:0% +is doing the least squares regression +you'll make a bunch of calibration + + align:start position:0% +you'll make a bunch of calibration + + + align:start position:0% +you'll make a bunch of calibration +curves when you are doing + + align:start position:0% +curves when you are doing + + + align:start position:0% +curves when you are doing +different measurements with uv vis + + align:start position:0% +different measurements with uv vis + + + align:start position:0% +different measurements with uv vis +spectroscopy + + align:start position:0% +spectroscopy + + + align:start position:0% +spectroscopy +so in uv vis which you'll talk about in + + align:start position:0% +so in uv vis which you'll talk about in + + + align:start position:0% +so in uv vis which you'll talk about in +the next couple of labs + + align:start position:0% +the next couple of labs + + + align:start position:0% +the next couple of labs +the absorbance of a sample at a certain + + align:start position:0% +the absorbance of a sample at a certain + + + align:start position:0% +the absorbance of a sample at a certain +wavelength + + align:start position:0% +wavelength + + + align:start position:0% +wavelength +how much of light it absorbs is related + + align:start position:0% +how much of light it absorbs is related + + + align:start position:0% +how much of light it absorbs is related +to + + align:start position:0% +to + + + align:start position:0% +to +its concentration and this + + align:start position:0% +its concentration and this + + + align:start position:0% +its concentration and this +is a calibration curve with the + + align:start position:0% +is a calibration curve with the + + + align:start position:0% +is a calibration curve with the +concentration of bovine serum albumin + + align:start position:0% +concentration of bovine serum albumin + + + align:start position:0% +concentration of bovine serum albumin +protein + + align:start position:0% +protein + + + align:start position:0% +protein +versus absorbance which you guys will be + + align:start position:0% +versus absorbance which you guys will be + + + align:start position:0% +versus absorbance which you guys will be +making a similar one + + align:start position:0% +making a similar one + + + align:start position:0% +making a similar one +in the catalase lab coming up so it + + align:start position:0% +in the catalase lab coming up so it + + + align:start position:0% +in the catalase lab coming up so it +assumes that one variable is known so + + align:start position:0% +assumes that one variable is known so + + + align:start position:0% +assumes that one variable is known so +that's our concentration that we have + + align:start position:0% +that's our concentration that we have + + + align:start position:0% +that's our concentration that we have +known concentrations and that + + align:start position:0% +known concentrations and that + + + align:start position:0% +known concentrations and that +all of the variation in the y + + align:start position:0% +all of the variation in the y + + + align:start position:0% +all of the variation in the y +axis is linearly related to our x values + + align:start position:0% +axis is linearly related to our x values + + + align:start position:0% +axis is linearly related to our x values +so that's one assumption that you have + + align:start position:0% +so that's one assumption that you have + + + align:start position:0% +so that's one assumption that you have +to have before you're going to make + + align:start position:0% +to have before you're going to make + + + align:start position:0% +to have before you're going to make +a least squares linear regression + + align:start position:0% +a least squares linear regression + + + align:start position:0% +a least squares linear regression +the way that you can calculate all of + + align:start position:0% +the way that you can calculate all of + + + align:start position:0% +the way that you can calculate all of +the + + align:start position:0% +the + + + align:start position:0% +the +values in a least squares regression + + align:start position:0% +values in a least squares regression + + + align:start position:0% +values in a least squares regression +which the + + align:start position:0% +which the + + + align:start position:0% +which the +whole idea of is + + align:start position:0% +whole idea of is + + + align:start position:0% +whole idea of is +to get an equation for a line in the + + align:start position:0% +to get an equation for a line in the + + + align:start position:0% +to get an equation for a line in the +form of y equals m x plus b + + align:start position:0% + + + + align:start position:0% + +so that's the point of all this um and + + align:start position:0% +so that's the point of all this um and + + + align:start position:0% +so that's the point of all this um and +you'll have different points + + align:start position:0% +you'll have different points + + + align:start position:0% +you'll have different points +and you want to calculate a straight + + align:start position:0% +and you want to calculate a straight + + + align:start position:0% +and you want to calculate a straight +line through all of your points + + align:start position:0% +line through all of your points + + + align:start position:0% +line through all of your points +so some of the terminology that is + + align:start position:0% +so some of the terminology that is + + + align:start position:0% +so some of the terminology that is +associated with this is the residual + + align:start position:0% +associated with this is the residual + + + align:start position:0% +associated with this is the residual +value + + align:start position:0% +value + + + align:start position:0% +value +and so that's your vertical distance + + align:start position:0% +and so that's your vertical distance + + + align:start position:0% +and so that's your vertical distance +between a point and the line of best fit + + align:start position:0% +between a point and the line of best fit + + + align:start position:0% +between a point and the line of best fit +so this is your residual value each + + align:start position:0% +so this is your residual value each + + + align:start position:0% +so this is your residual value each +point has + + align:start position:0% +point has + + + align:start position:0% +point has +a residual value and the way that + + align:start position:0% +a residual value and the way that + + + align:start position:0% +a residual value and the way that +the line of best fit is generated in the + + align:start position:0% +the line of best fit is generated in the + + + align:start position:0% +the line of best fit is generated in the +least squares method is they take the + + align:start position:0% +least squares method is they take the + + + align:start position:0% +least squares method is they take the +square of all of these residual values + + align:start position:0% +square of all of these residual values + + + align:start position:0% +square of all of these residual values +and try to minimize it + + align:start position:0% + + + + align:start position:0% + +and so you can calculate various + + align:start position:0% +and so you can calculate various + + + align:start position:0% +and so you can calculate various +quantities if you take all of the + + align:start position:0% +quantities if you take all of the + + + align:start position:0% +quantities if you take all of the +x values subtract them from the average + + align:start position:0% +x values subtract them from the average + + + align:start position:0% +x values subtract them from the average +x and square them then you'll get the s + + align:start position:0% +x and square them then you'll get the s + + + align:start position:0% +x and square them then you'll get the s +x x + + align:start position:0% +x x + + + align:start position:0% +x x +the you could do the same thing with the + + align:start position:0% +the you could do the same thing with the + + + align:start position:0% +the you could do the same thing with the +y values and then the x and the y + + align:start position:0% +y values and then the x and the y + + + align:start position:0% +y values and then the x and the y +values the slope of the line + + align:start position:0% +values the slope of the line + + + align:start position:0% +values the slope of the line +is this value over this one + + align:start position:0% +is this value over this one + + + align:start position:0% +is this value over this one +to get the y intercept you take the + + align:start position:0% +to get the y intercept you take the + + + align:start position:0% +to get the y intercept you take the +average y subtract it from the slope and + + align:start position:0% +average y subtract it from the slope and + + + align:start position:0% +average y subtract it from the slope and +the average x + + align:start position:0% +the average x + + + align:start position:0% +the average x +and then the r squared this was a + + align:start position:0% +and then the r squared this was a + + + align:start position:0% +and then the r squared this was a +misprint in your + + align:start position:0% +misprint in your + + + align:start position:0% +misprint in your +slide handouts it should be one minus + + align:start position:0% +slide handouts it should be one minus + + + align:start position:0% +slide handouts it should be one minus +this quantity um in the slide in the + + align:start position:0% +this quantity um in the slide in the + + + align:start position:0% +this quantity um in the slide in the +handouts the one is not on there + + align:start position:0% +handouts the one is not on there + + + align:start position:0% +handouts the one is not on there +um and so + + align:start position:0% +um and so + + + align:start position:0% +um and so +the r squared value which you've + + align:start position:0% +the r squared value which you've + + + align:start position:0% +the r squared value which you've +probably seen before is the coefficient + + align:start position:0% +probably seen before is the coefficient + + + align:start position:0% +probably seen before is the coefficient +of determination + + align:start position:0% +of determination + + + align:start position:0% +of determination +and that is a measure of how well this + + align:start position:0% +and that is a measure of how well this + + + align:start position:0% +and that is a measure of how well this +best fit line can explain + + align:start position:0% +best fit line can explain + + + align:start position:0% +best fit line can explain +the variation in y in a linear fashion + + align:start position:0% +the variation in y in a linear fashion + + + align:start position:0% +the variation in y in a linear fashion +so essentially how well do your points + + align:start position:0% +so essentially how well do your points + + + align:start position:0% +so essentially how well do your points +fit + + align:start position:0% +fit + + + align:start position:0% +fit +a linear relationship is that a good way + + align:start position:0% +a linear relationship is that a good way + + + align:start position:0% +a linear relationship is that a good way +to explain your data + + align:start position:0% + + + + align:start position:0% + +so the best way to generate this is in + + align:start position:0% +so the best way to generate this is in + + + align:start position:0% +so the best way to generate this is in +excel you can calculate all those + + align:start position:0% +excel you can calculate all those + + + align:start position:0% +excel you can calculate all those +quantities by hand if you want to but + + align:start position:0% +quantities by hand if you want to but + + + align:start position:0% +quantities by hand if you want to but +excel will do it for you + + align:start position:0% +excel will do it for you + + + align:start position:0% +excel will do it for you +or your other favorite mathematical + + align:start position:0% +or your other favorite mathematical + + + align:start position:0% +or your other favorite mathematical +software program + + align:start position:0% +software program + + + align:start position:0% +software program +you graph your points as an xy scatter + + align:start position:0% +you graph your points as an xy scatter + + + align:start position:0% +you graph your points as an xy scatter +plot then you can right click the data + + align:start position:0% +plot then you can right click the data + + + align:start position:0% +plot then you can right click the data +points and it'll say add trendline and + + align:start position:0% +points and it'll say add trendline and + + + align:start position:0% +points and it'll say add trendline and +then you can + + align:start position:0% +then you can + + + align:start position:0% +then you can +have options to display the equation and + + align:start position:0% +have options to display the equation and + + + align:start position:0% +have options to display the equation and +the r squared on the graph + + align:start position:0% +the r squared on the graph + + + align:start position:0% +the r squared on the graph +so you'll get your y equals mx plus b + + align:start position:0% +so you'll get your y equals mx plus b + + + align:start position:0% +so you'll get your y equals mx plus b +equation there and your r squared value + + align:start position:0% +equation there and your r squared value + + + align:start position:0% +equation there and your r squared value +there so you can see that this this line + + align:start position:0% +there so you can see that this this line + + + align:start position:0% +there so you can see that this this line +is this is not a very linear set of data + + align:start position:0% +is this is not a very linear set of data + + + align:start position:0% +is this is not a very linear set of data +so your r squared + + align:start position:0% +so your r squared + + + align:start position:0% +so your r squared +ideally is close to one um + + align:start position:0% +ideally is close to one um + + + align:start position:0% +ideally is close to one um +and this is close-ish to one but that is + + align:start position:0% +and this is close-ish to one but that is + + + align:start position:0% +and this is close-ish to one but that is +definitely not a linear relationship you + + align:start position:0% +definitely not a linear relationship you + + + align:start position:0% +definitely not a linear relationship you +can def + + align:start position:0% +can def + + + align:start position:0% +can def +you can get it higher than that and + + align:start position:0% +you can get it higher than that and + + + align:start position:0% +you can get it higher than that and +we'll talk about that more when you guys + + align:start position:0% +we'll talk about that more when you guys + + + align:start position:0% +we'll talk about that more when you guys +make your + + align:start position:0% +make your + + + align:start position:0% +make your +calibration curves for the bovine serum + + align:start position:0% +calibration curves for the bovine serum + + + align:start position:0% +calibration curves for the bovine serum +albumin the kumasi blue dye is only + + align:start position:0% +albumin the kumasi blue dye is only + + + align:start position:0% +albumin the kumasi blue dye is only +linear in certain regions of the + + align:start position:0% +linear in certain regions of the + + + align:start position:0% +linear in certain regions of the +calibration curve + + align:start position:0% +calibration curve + + + align:start position:0% +calibration curve +so you'll have to calculate different + + align:start position:0% +so you'll have to calculate different + + + align:start position:0% +so you'll have to calculate different +lines for different pieces of the curve + + align:start position:0% +lines for different pieces of the curve + + + align:start position:0% +lines for different pieces of the curve +depending on what your concentration is + + align:start position:0% + + + + align:start position:0% + +the last thing that we can do to get + + align:start position:0% +the last thing that we can do to get + + + align:start position:0% +the last thing that we can do to get +more information out of a set of linear + + align:start position:0% +more information out of a set of linear + + + align:start position:0% +more information out of a set of linear +data is to use the linus program in + + align:start position:0% +data is to use the linus program in + + + align:start position:0% +data is to use the linus program in +excel + + align:start position:0% +excel + + + align:start position:0% +excel +and if you've never done this before you + + align:start position:0% +and if you've never done this before you + + + align:start position:0% +and if you've never done this before you +type in your data + + align:start position:0% +type in your data + + + align:start position:0% +type in your data +as a series of x and y points and then + + align:start position:0% +as a series of x and y points and then + + + align:start position:0% +as a series of x and y points and then +instead of graphing it + + align:start position:0% +instead of graphing it + + + align:start position:0% +instead of graphing it +well you can graph it too but in + + align:start position:0% +well you can graph it too but in + + + align:start position:0% +well you can graph it too but in +addition to graphing it you highlight + + align:start position:0% +addition to graphing it you highlight + + + align:start position:0% +addition to graphing it you highlight +a two by five area of empty cells + + align:start position:0% +a two by five area of empty cells + + + align:start position:0% +a two by five area of empty cells +and while that's highlighted in the + + align:start position:0% +and while that's highlighted in the + + + align:start position:0% +and while that's highlighted in the +first + + align:start position:0% +first + + + align:start position:0% +first +cell you type in equals linest and then + + align:start position:0% +cell you type in equals linest and then + + + align:start position:0% +cell you type in equals linest and then +it'll prompt you to highlight your y + + align:start position:0% +it'll prompt you to highlight your y + + + align:start position:0% +it'll prompt you to highlight your y +values then highlight your x values and + + align:start position:0% +values then highlight your x values and + + + align:start position:0% +values then highlight your x values and +then you can type true + + align:start position:0% +then you can type true + + + align:start position:0% +then you can type true +and true and what that'll do is if you + + align:start position:0% +and true and what that'll do is if you + + + align:start position:0% +and true and what that'll do is if you +type false it'll set the + + align:start position:0% +type false it'll set the + + + align:start position:0% +type false it'll set the +y intercept to zero and we don't want to + + align:start position:0% +y intercept to zero and we don't want to + + + align:start position:0% +y intercept to zero and we don't want to +force our lines through zero so + + align:start position:0% +force our lines through zero so + + + align:start position:0% +force our lines through zero so +you will have your slope and then if you + + align:start position:0% +you will have your slope and then if you + + + align:start position:0% +you will have your slope and then if you +press ctrl shift enter even on a mac so + + align:start position:0% +press ctrl shift enter even on a mac so + + + align:start position:0% +press ctrl shift enter even on a mac so +on a mac press control not command + + align:start position:0% +on a mac press control not command + + + align:start position:0% +on a mac press control not command +press ctrl shift enter and it'll give + + align:start position:0% +press ctrl shift enter and it'll give + + + align:start position:0% +press ctrl shift enter and it'll give +you this array of data + + align:start position:0% +you this array of data + + + align:start position:0% +you this array of data +once you get this array of data don't + + align:start position:0% +once you get this array of data don't + + + align:start position:0% +once you get this array of data don't +try to change any of these values or + + align:start position:0% +try to change any of these values or + + + align:start position:0% +try to change any of these values or +excel will get kind of mad at you + + align:start position:0% +excel will get kind of mad at you + + + align:start position:0% +excel will get kind of mad at you +so just leave it and this is the key to + + align:start position:0% +so just leave it and this is the key to + + + align:start position:0% +so just leave it and this is the key to +what each of the + + align:start position:0% +what each of the + + + align:start position:0% +what each of the +cells is telling you because it won't + + align:start position:0% +cells is telling you because it won't + + + align:start position:0% +cells is telling you because it won't +give you this information you can look + + align:start position:0% +give you this information you can look + + + align:start position:0% +give you this information you can look +it up online or it'll be on these slides + + align:start position:0% +it up online or it'll be on these slides + + + align:start position:0% +it up online or it'll be on these slides +um so your first thing it'll just give + + align:start position:0% +um so your first thing it'll just give + + + align:start position:0% +um so your first thing it'll just give +you your slope and your intercept and + + align:start position:0% +you your slope and your intercept and + + + align:start position:0% +you your slope and your intercept and +then it'll give you these are the two + + align:start position:0% +then it'll give you these are the two + + + align:start position:0% +then it'll give you these are the two +that we care about the most + + align:start position:0% +that we care about the most + + + align:start position:0% +that we care about the most +are the standard deviation of the slope + + align:start position:0% +are the standard deviation of the slope + + + align:start position:0% +are the standard deviation of the slope +and the standard deviation of the + + align:start position:0% +and the standard deviation of the + + + align:start position:0% +and the standard deviation of the +y-intercept so sometimes in this course + + align:start position:0% +y-intercept so sometimes in this course + + + align:start position:0% +y-intercept so sometimes in this course +you'll make graphs where the slope is + + align:start position:0% +you'll make graphs where the slope is + + + align:start position:0% +you'll make graphs where the slope is +representative of a certain quantity + + align:start position:0% +representative of a certain quantity + + + align:start position:0% +representative of a certain quantity +or the y-intercept is representative of + + align:start position:0% +or the y-intercept is representative of + + + align:start position:0% +or the y-intercept is representative of +a certain quantity if you're graphing + + align:start position:0% +a certain quantity if you're graphing + + + align:start position:0% +a certain quantity if you're graphing +any equation in linear form so then + + align:start position:0% +any equation in linear form so then + + + align:start position:0% +any equation in linear form so then +you'll have the standard deviations of + + align:start position:0% +you'll have the standard deviations of + + + align:start position:0% +you'll have the standard deviations of +each of those measurements + + align:start position:0% +each of those measurements + + + align:start position:0% +each of those measurements +then it'll also give you your r squared + + align:start position:0% +then it'll also give you your r squared + + + align:start position:0% +then it'll also give you your r squared +and a bunch of other information that + + align:start position:0% +and a bunch of other information that + + + align:start position:0% +and a bunch of other information that +you want + + align:start position:0% +you want + + + align:start position:0% +you want +if you're doing different statistical + + align:start position:0% + + + + align:start position:0% + +tests + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/tnnuIwgXAt8.txt b/tnnuIwgXAt8.txt new file mode 100644 index 0000000000000000000000000000000000000000..1e9960d16a69792e18048483b015ab67f447b5b5 --- /dev/null +++ b/tnnuIwgXAt8.txt @@ -0,0 +1,15843 @@ +align:start position:0% + +Good. All right. + + align:start position:0% +Good. All right. + + + align:start position:0% +Good. All right. +Um, so we're heading in to + + align:start position:0% +Um, so we're heading in to + + + align:start position:0% +Um, so we're heading in to +our our + + align:start position:0% +our our + + + align:start position:0% +our our +last of + + align:start position:0% +last of + + + align:start position:0% +last of +the as yet intractable dilemmas. We + + align:start position:0% +the as yet intractable dilemmas. We + + + align:start position:0% +the as yet intractable dilemmas. We +talked about the curse of familiar atte + + align:start position:0% +talked about the curse of familiar atte + + + align:start position:0% +talked about the curse of familiar atte +uh assessment and today the toxic power + + align:start position:0% +uh assessment and today the toxic power + + + align:start position:0% +uh assessment and today the toxic power +of data and experiment. Um let's do this + + align:start position:0% +of data and experiment. Um let's do this + + + align:start position:0% +of data and experiment. Um let's do this +as an exercise. Grab one other person. + + align:start position:0% +as an exercise. Grab one other person. + + + align:start position:0% +as an exercise. Grab one other person. +Your goal is to make a list as long as + + align:start position:0% +Your goal is to make a list as long as + + + align:start position:0% +Your goal is to make a list as long as +possible. Um what is all the data that + + align:start position:0% +possible. Um what is all the data that + + + align:start position:0% +possible. Um what is all the data that +MIT has about + + align:start position:0% +MIT has about + + + align:start position:0% +MIT has about +you? If you if you could if you could go + + align:start position:0% +you? If you if you could if you could go + + + align:start position:0% +you? If you if you could if you could go +through every server that is somehow + + align:start position:0% +through every server that is somehow + + + align:start position:0% +through every server that is somehow +even tangentially under the control of + + align:start position:0% +even tangentially under the control of + + + align:start position:0% +even tangentially under the control of +MIT, what are all the different types + + align:start position:0% +MIT, what are all the different types + + + align:start position:0% +MIT, what are all the different types +and sources and nature and example of + + align:start position:0% +and sources and nature and example of + + + align:start position:0% +and sources and nature and example of +data that MIT has about you? Does that + + align:start position:0% +data that MIT has about you? Does that + + + align:start position:0% +data that MIT has about you? Does that +make sense? Make the list as long as you + + align:start position:0% +make sense? Make the list as long as you + + + align:start position:0% +make sense? Make the list as long as you +can, as fast as you can. Ready? Go. + + align:start position:0% +can, as fast as you can. Ready? Go. + + + align:start position:0% +can, as fast as you can. Ready? Go. +All right. Let's let's let's start let's + + align:start position:0% +All right. Let's let's let's start let's + + + align:start position:0% +All right. Let's let's let's start let's +start aggregating some big categories of + + align:start position:0% +start aggregating some big categories of + + + align:start position:0% +start aggregating some big categories of +things. + + align:start position:0% +things. + + + align:start position:0% +things. +financial information. Okay, so they + + align:start position:0% +financial information. Okay, so they + + + align:start position:0% +financial information. Okay, so they +have a lot of financial information. + + align:start position:0% +have a lot of financial information. + + + align:start position:0% +have a lot of financial information. +Maybe just like what are a few examples + + align:start position:0% +Maybe just like what are a few examples + + + align:start position:0% +Maybe just like what are a few examples +of some of the most maybe sensitive or + + align:start position:0% +of some of the most maybe sensitive or + + + align:start position:0% +of some of the most maybe sensitive or +personal parts of that. + + align:start position:0% +personal parts of that. + + + align:start position:0% +personal parts of that. +They know your parents income. They know + + align:start position:0% +They know your parents income. They know + + + align:start position:0% +They know your parents income. They know +your know your income. Your income. They + + align:start position:0% +your know your income. Your income. They + + + align:start position:0% +your know your income. Your income. They +know your bank bank account. They they + + align:start position:0% +know your bank bank account. They they + + + align:start position:0% +know your bank bank account. They they +know your bank account number or like + + align:start position:0% +know your bank account number or like + + + align:start position:0% +know your bank account number or like +you give them literally but they they + + align:start position:0% +you give them literally but they they + + + align:start position:0% +you give them literally but they they +don't like have a screenshot of your + + align:start position:0% +don't like have a screenshot of your + + + align:start position:0% +don't like have a screenshot of your +like for example. All right. So they + + align:start position:0% +like for example. All right. So they + + + align:start position:0% +like for example. All right. So they +know a lot of financial things about + + align:start position:0% +know a lot of financial things about + + + align:start position:0% +know a lot of financial things about +you. + + align:start position:0% +you. + + + align:start position:0% +you. +What what are some other categories? + + align:start position:0% +What what are some other categories? + + + align:start position:0% +What what are some other categories? +Health. + + align:start position:0% + + + + align:start position:0% + +What are some sensitive things in there? + + align:start position:0% +What are some sensitive things in there? + + + align:start position:0% +What are some sensitive things in there? +History. + + align:start position:0% +History. + + + align:start position:0% +History. +History. + + align:start position:0% +History. + + + align:start position:0% +History. +Vaccinations. + + align:start position:0% +Vaccinations. + + + align:start position:0% +Vaccinations. +Vaccinations. Prescriptions. + + align:start position:0% +Vaccinations. Prescriptions. + + + align:start position:0% +Vaccinations. Prescriptions. +Allergies. Allergies. + + align:start position:0% + + + + align:start position:0% + +Mental health + + align:start position:0% +Mental health + + + align:start position:0% +Mental health +visits. Insurance. + + align:start position:0% +visits. Insurance. + + + align:start position:0% +visits. Insurance. +You can also tell people are LGBT + + align:start position:0% + + + + align:start position:0% + +sexual + + align:start position:0% +sexual + + + align:start position:0% +sexual +orientation activity. + + align:start position:0% +orientation activity. + + + align:start position:0% +orientation activity. +Okay. What else you got? + + align:start position:0% + + + + align:start position:0% + +Yeah. Register. Let's call it registar + + align:start position:0% +Yeah. Register. Let's call it registar + + + align:start position:0% +Yeah. Register. Let's call it registar +information. + + align:start position:0% + + + + align:start position:0% + +Name + + align:start position:0% + + + + align:start position:0% + +address phone. + + align:start position:0% + + + + align:start position:0% + +Oh, they might have their travel data. + + align:start position:0% +Oh, they might have their travel data. + + + align:start position:0% +Oh, they might have their travel data. +Yeah, if you have travels, you have to + + align:start position:0% +Yeah, if you have travels, you have to + + + align:start position:0% +Yeah, if you have travels, you have to +register. + + align:start position:0% + + + + align:start position:0% + +Like MIT knows. + + align:start position:0% +Like MIT knows. + + + align:start position:0% +Like MIT knows. +Yeah, especially if you've been + + align:start position:0% +Yeah, especially if you've been + + + align:start position:0% +Yeah, especially if you've been +international. If you do it through the + + align:start position:0% +international. If you do it through the + + + align:start position:0% +international. If you do it through the +screen, + + align:start position:0% +screen, + + + align:start position:0% +screen, +or if you're going to like a country + + align:start position:0% +or if you're going to like a country + + + align:start position:0% +or if you're going to like a country +that they have warnings for, you have to + + align:start position:0% +that they have warnings for, you have to + + + align:start position:0% +that they have warnings for, you have to +be like, I was there. Wow. + + align:start position:0% + + + + align:start position:0% + +What else we got? Academic records. + + align:start position:0% +What else we got? Academic records. + + + align:start position:0% +What else we got? Academic records. +Good. + + align:start position:0% +Good. + + + align:start position:0% +Good. +That's part academic records. + + align:start position:0% +That's part academic records. + + + align:start position:0% +That's part academic records. +What What would that include these days? + + align:start position:0% +What What would that include these days? + + + align:start position:0% +What What would that include these days? +They know your grades. What else? + + align:start position:0% +They know your grades. What else? + + + align:start position:0% +They know your grades. What else? +Registration. Like what classes you show + + align:start position:0% +Registration. Like what classes you show + + + align:start position:0% +Registration. Like what classes you show +up for? + + align:start position:0% + + + + align:start position:0% + +Test scores. + + align:start position:0% +Test scores. + + + align:start position:0% +Test scores. +Every click ever in Canvas. + + align:start position:0% +Every click ever in Canvas. + + + align:start position:0% +Every click ever in Canvas. +Attendance. + + align:start position:0% +Attendance. + + + align:start position:0% +Attendance. +Yeah. Um, academic records is a good + + align:start position:0% +Yeah. Um, academic records is a good + + + align:start position:0% +Yeah. Um, academic records is a good +example of one for which the the + + align:start position:0% +example of one for which the the + + + align:start position:0% +example of one for which the the +granularity of data over the last 10 + + align:start position:0% +granularity of data over the last 10 + + + align:start position:0% +granularity of data over the last 10 +years has transformed dramatically. Like + + align:start position:0% +years has transformed dramatically. Like + + + align:start position:0% +years has transformed dramatically. Like +if you if you if we had had this + + align:start position:0% +if you if you if we had had this + + + align:start position:0% +if you if you if we had had this +discussion in 1980, they would have been + + align:start position:0% +discussion in 1980, they would have been + + + align:start position:0% +discussion in 1980, they would have been +like, I guess they know what my grades + + align:start position:0% +like, I guess they know what my grades + + + align:start position:0% +like, I guess they know what my grades +were and what classes I signed up for. + + align:start position:0% +were and what classes I signed up for. + + + align:start position:0% +were and what classes I signed up for. +Um, but the volume of data about every + + align:start position:0% +Um, but the volume of data about every + + + align:start position:0% +Um, but the volume of data about every +activity that you've ever taken online + + align:start position:0% +activity that you've ever taken online + + + align:start position:0% +activity that you've ever taken online +in any of your classes is substantially + + align:start position:0% +in any of your classes is substantially + + + align:start position:0% +in any of your classes is substantially +higher um than it used to be. Those + + align:start position:0% +higher um than it used to be. Those + + + align:start position:0% +higher um than it used to be. Those +records might not be maintained forever. + + align:start position:0% +records might not be maintained forever. + + + align:start position:0% +records might not be maintained forever. +Maybe all those sites get deleted every + + align:start position:0% +Maybe all those sites get deleted every + + + align:start position:0% +Maybe all those sites get deleted every +18 months or so. Something like that. Um + + align:start position:0% +18 months or so. Something like that. Um + + + align:start position:0% +18 months or so. Something like that. Um +but some of them might be kept for + + align:start position:0% +but some of them might be kept for + + + align:start position:0% +but some of them might be kept for +longer for research or other things like + + align:start position:0% +longer for research or other things like + + + align:start position:0% +longer for research or other things like +that. All right. Other categories. + + align:start position:0% +that. All right. Other categories. + + + align:start position:0% +that. All right. Other categories. +Residential. Yeah. Home and current. + + align:start position:0% +Residential. Yeah. Home and current. + + + align:start position:0% +Residential. Yeah. Home and current. +Um let's make it even bigger. Let's say + + align:start position:0% +Um let's make it even bigger. Let's say + + + align:start position:0% +Um let's make it even bigger. Let's say +location. Um so they know your + + align:start position:0% +location. Um so they know your + + + align:start position:0% +location. Um so they know your +residence. + + align:start position:0% +residence. + + + align:start position:0% +residence. +Um home and campus. + + align:start position:0% +Um home and campus. + + + align:start position:0% +Um home and campus. +um track your devices on Wi-Fi. + + align:start position:0% +um track your devices on Wi-Fi. + + + align:start position:0% +um track your devices on Wi-Fi. +Card swipes in buildings. Um we have + + align:start position:0% +Card swipes in buildings. Um we have + + + align:start position:0% +Card swipes in buildings. Um we have +some um so you know essentially as you + + align:start position:0% +some um so you know essentially as you + + + align:start position:0% +some um so you know essentially as you +move around campus it is some somewhere + + align:start position:0% +move around campus it is some somewhere + + + align:start position:0% +move around campus it is some somewhere +someone somewhere somewhere there are + + align:start position:0% +someone somewhere somewhere there are + + + align:start position:0% +someone somewhere somewhere there are +databases that record all those + + align:start position:0% +databases that record all those + + + align:start position:0% +databases that record all those +activities how long you know how long + + align:start position:0% +activities how long you know how long + + + align:start position:0% +activities how long you know how long +they maintain those materials we don't + + align:start position:0% +they maintain those materials we don't + + + align:start position:0% +they maintain those materials we don't +necessarily know but I mean I'm sure + + align:start position:0% +necessarily know but I mean I'm sure + + + align:start position:0% +necessarily know but I mean I'm sure +they tell us if we asked but what else + + align:start position:0% +they tell us if we asked but what else + + + align:start position:0% +they tell us if we asked but what else +they got + + align:start position:0% +they got + + + align:start position:0% +they got +from that location they can also tell + + align:start position:0% +from that location they can also tell + + + align:start position:0% +from that location they can also tell +like who you hang your outfit + + align:start position:0% +like who you hang your outfit + + + align:start position:0% +like who you hang your outfit +yeah I just learned about this today + + align:start position:0% +yeah I just learned about this today + + + align:start position:0% +yeah I just learned about this today +what's the system of where you add + + align:start position:0% +what's the system of where you add + + + align:start position:0% +what's the system of where you add +people okay so I guess if you live in a + + align:start position:0% +people okay so I guess if you live in a + + + align:start position:0% +people okay so I guess if you live in a +residence you create a guest list of + + align:start position:0% +residence you create a guest list of + + + align:start position:0% +residence you create a guest list of +people that are allowed to visit you. + + align:start position:0% +people that are allowed to visit you. + + + align:start position:0% +people that are allowed to visit you. +Like that's like you can just + + align:start position:0% +Like that's like you can just + + + align:start position:0% +Like that's like you can just +reconstitute the entire social network + + align:start position:0% +reconstitute the entire social network + + + align:start position:0% +reconstitute the entire social network +of MIT from the get list, you know. Um + + align:start position:0% +of MIT from the get list, you know. Um + + + align:start position:0% +of MIT from the get list, you know. Um +yeah, there's there's all kinds of + + align:start position:0% +yeah, there's there's all kinds of + + + align:start position:0% +yeah, there's there's all kinds of +things you can learn from that. It's + + align:start position:0% +things you can learn from that. It's + + + align:start position:0% +things you can learn from that. It's +like extracurricular activities so they + + align:start position:0% +like extracurricular activities so they + + + align:start position:0% +like extracurricular activities so they +know what sports teams and like + + align:start position:0% +know what sports teams and like + + + align:start position:0% +know what sports teams and like +athletics like stats on that. And then + + align:start position:0% +athletics like stats on that. And then + + + align:start position:0% +athletics like stats on that. And then +if you signed up for like club teams, + + align:start position:0% +if you signed up for like club teams, + + + align:start position:0% +if you signed up for like club teams, +it would be all those kinds of things. + + align:start position:0% +it would be all those kinds of things. + + + align:start position:0% +it would be all those kinds of things. +as well. Yeah, your + + align:start position:0% +as well. Yeah, your + + + align:start position:0% +as well. Yeah, your +gym gym membership swipes activity + + align:start position:0% +gym gym membership swipes activity + + + align:start position:0% +gym gym membership swipes activity +political affiliations. How would they + + align:start position:0% +political affiliations. How would they + + + align:start position:0% +political affiliations. How would they +how would how would they get your + + align:start position:0% +how would how would they get your + + + align:start position:0% +how would how would they get your +political affiliation? + + align:start position:0% +political affiliation? + + + align:start position:0% +political affiliation? +Like if you're involved with the recent + + align:start position:0% +Like if you're involved with the recent + + + align:start position:0% +Like if you're involved with the recent +stuff that's been going on in campus. + + align:start position:0% +stuff that's been going on in campus. + + + align:start position:0% +stuff that's been going on in campus. +Yeah. Or you know and or Yeah. Yeah. + + align:start position:0% +Yeah. Or you know and or Yeah. Yeah. + + + align:start position:0% +Yeah. Or you know and or Yeah. Yeah. +Yeah. Good. So, um there are presum you + + align:start position:0% +Yeah. Good. So, um there are presum you + + + align:start position:0% +Yeah. Good. So, um there are presum you +know increasingly presumably lists of + + align:start position:0% +know increasingly presumably lists of + + + align:start position:0% +know increasingly presumably lists of +people who are um affiliated with pro + + align:start position:0% +people who are um affiliated with pro + + + align:start position:0% +people who are um affiliated with pro +Palestinian, pro-Israeli, any of those + + align:start position:0% +Palestinian, pro-Israeli, any of those + + + align:start position:0% +Palestinian, pro-Israeli, any of those +other kinds of things. But also people + + align:start position:0% +other kinds of things. But also people + + + align:start position:0% +other kinds of things. But also people +would have just been able to tell before + + align:start position:0% +would have just been able to tell before + + + align:start position:0% +would have just been able to tell before +if you remember I don't I assume there + + align:start position:0% +if you remember I don't I assume there + + + align:start position:0% +if you remember I don't I assume there +there's a Democrat and Republican club + + align:start position:0% +there's a Democrat and Republican club + + + align:start position:0% +there's a Democrat and Republican club +at MIT I would imagine + + align:start position:0% +at MIT I would imagine + + + align:start position:0% +at MIT I would imagine +um someone somewhere emails. Yes, they + + align:start position:0% +um someone somewhere emails. Yes, they + + + align:start position:0% +um someone somewhere emails. Yes, they +have the entirety of your email record + + align:start position:0% +have the entirety of your email record + + + align:start position:0% +have the entirety of your email record +even like broader just like online + + align:start position:0% +even like broader just like online + + + align:start position:0% +even like broader just like online +activity because like emails, websites, + + align:start position:0% +activity because like emails, websites, + + + align:start position:0% +activity because like emails, websites, +anything you've registered for. Yeah, + + align:start position:0% +anything you've registered for. Yeah, + + + align:start position:0% +anything you've registered for. Yeah, +they also offer like a + + align:start position:0% +they also offer like a + + + align:start position:0% +they also offer like a +VPN. So + + align:start position:0% +VPN. So + + + align:start position:0% +VPN. So +like it's secure to everyone but like + + align:start position:0% +like it's secure to everyone but like + + + align:start position:0% +like it's secure to everyone but like +you also have your like Google Drive if + + align:start position:0% +you also have your like Google Drive if + + + align:start position:0% +you also have your like Google Drive if +you sign up for the NYC. + + align:start position:0% + + + + align:start position:0% + +Yeah. Um I had a congressional committee + + align:start position:0% +Yeah. Um I had a congressional committee + + + align:start position:0% +Yeah. Um I had a congressional committee +that wanted to find out more about my + + align:start position:0% +that wanted to find out more about my + + + align:start position:0% +that wanted to find out more about my +work um not necessarily in a generous + + align:start position:0% +work um not necessarily in a generous + + + align:start position:0% +work um not necessarily in a generous +way. um this past year um and uh and the + + align:start position:0% +way. um this past year um and uh and the + + + align:start position:0% +way. um this past year um and uh and the +the office of general counsel did like a + + align:start position:0% +the office of general counsel did like a + + + align:start position:0% +the office of general counsel did like a +whole search throughout my email um to + + align:start position:0% +whole search throughout my email um to + + + align:start position:0% +whole search throughout my email um to +find terms that this congressional + + align:start position:0% +find terms that this congressional + + + align:start position:0% +find terms that this congressional +committee was interested in learning + + align:start position:0% +committee was interested in learning + + + align:start position:0% +committee was interested in learning +more about um and uh and they you were + + align:start position:0% +more about um and uh and they you were + + + align:start position:0% +more about um and uh and they you were +going back and forth and I was sort of + + align:start position:0% +going back and forth and I was sort of + + + align:start position:0% +going back and forth and I was sort of +like you know what do you need from me + + align:start position:0% +like you know what do you need from me + + + align:start position:0% +like you know what do you need from me +and they were like well it's better if + + align:start position:0% +and they were like well it's better if + + + align:start position:0% +and they were like well it's better if +you if you help us with this but like + + align:start position:0% +you if you help us with this but like + + + align:start position:0% +you if you help us with this but like +either way we're going to do it. Um so + + align:start position:0% +either way we're going to do it. Um so + + + align:start position:0% +either way we're going to do it. Um so +uh um yeah all you know all the all the + + align:start position:0% +uh um yeah all you know all the all the + + + align:start position:0% +uh um yeah all you know all the all the +records that you generate and and that + + align:start position:0% +records that you generate and and that + + + align:start position:0% +records that you generate and and that +that that's a good example of how even + + align:start position:0% +that that's a good example of how even + + + align:start position:0% +that that's a good example of how even +like you know how I'm reasonably + + align:start position:0% +like you know how I'm reasonably + + + align:start position:0% +like you know how I'm reasonably +confident that in most circumstances + + align:start position:0% +confident that in most circumstances + + + align:start position:0% +confident that in most circumstances +like MIT is not going through my email + + align:start position:0% +like MIT is not going through my email + + + align:start position:0% +like MIT is not going through my email +every day and like what's Justin up to + + align:start position:0% +every day and like what's Justin up to + + + align:start position:0% +every day and like what's Justin up to +you know like they don't care. Um but + + align:start position:0% +you know like they don't care. Um but + + + align:start position:0% +you know like they don't care. Um but +simply having those records um allows + + align:start position:0% +simply having those records um allows + + + align:start position:0% +simply having those records um allows +all kinds of things to happen with those + + align:start position:0% +all kinds of things to happen with those + + + align:start position:0% +all kinds of things to happen with those +records. Um, + + align:start position:0% +records. Um, + + + align:start position:0% +records. Um, +uh, do you do you guys have automated + + align:start position:0% +uh, do you do you guys have automated + + + align:start position:0% +uh, do you do you guys have automated +laundry machines? + + align:start position:0% + + + + align:start position:0% + +Washing frequency. + + align:start position:0% +Washing frequency. + + + align:start position:0% +Washing frequency. +It's like an app. Yeah. Yeah. It's even + + align:start position:0% +It's like an app. Yeah. Yeah. It's even + + + align:start position:0% +It's like an app. Yeah. Yeah. It's even +an app like it's an app like you pay for + + align:start position:0% +an app like it's an app like you pay for + + + align:start position:0% +an app like it's an app like you pay for +your machine and you have to sign up for + + align:start position:0% +your machine and you have to sign up for + + + align:start position:0% +your machine and you have to sign up for +your email. Yeah. You have to do + + align:start position:0% +your email. Yeah. You have to do + + + align:start position:0% +your email. Yeah. You have to do +um Yeah. Yeah. And so that I mean that I + + align:start position:0% +um Yeah. Yeah. And so that I mean that I + + + align:start position:0% +um Yeah. Yeah. And so that I mean that I +think also raises some questions of like + + align:start position:0% +think also raises some questions of like + + + align:start position:0% +think also raises some questions of like +um it's possible actually that MIT + + align:start position:0% +um it's possible actually that MIT + + + align:start position:0% +um it's possible actually that MIT +doesn't have your laundry data, but that + + align:start position:0% +doesn't have your laundry data, but that + + + align:start position:0% +doesn't have your laundry data, but that +MIT just somehow mandates that a third + + align:start position:0% +MIT just somehow mandates that a third + + + align:start position:0% +MIT just somehow mandates that a third +party has all of your laundry data. Um + + align:start position:0% +party has all of your laundry data. Um + + + align:start position:0% +party has all of your laundry data. Um +which again like how keys to your room + + align:start position:0% +which again like how keys to your room + + + align:start position:0% +which again like how keys to your room +if you live on campus. Yeah. Um like + + align:start position:0% +if you live on campus. Yeah. Um like + + + align:start position:0% +if you live on campus. Yeah. Um like +physically. Yeah. + + align:start position:0% +physically. Yeah. + + + align:start position:0% +physically. Yeah. +Keys. Um what what's good about them + + align:start position:0% +Keys. Um what what's good about them + + + align:start position:0% +Keys. Um what what's good about them +having keys? + + align:start position:0% +having keys? + + + align:start position:0% +having keys? +Yeah. Yeah. Yeah. So, you know, I mean, + + align:start position:0% +Yeah. Yeah. Yeah. So, you know, I mean, + + + align:start position:0% +Yeah. Yeah. Yeah. So, you know, I mean, +and an and you know, like like if + + align:start position:0% +and an and you know, like like if + + + align:start position:0% +and an and you know, like like if +there's a day that you're locked out of + + align:start position:0% +there's a day that you're locked out of + + + align:start position:0% +there's a day that you're locked out of +your room, you're going to be like, "It + + align:start position:0% +your room, you're going to be like, "It + + + align:start position:0% +your room, you're going to be like, "It +is so great that MIT knows exactly what + + align:start position:0% +is so great that MIT knows exactly what + + + align:start position:0% +is so great that MIT knows exactly what +key goes in my door and can make another + + align:start position:0% +key goes in my door and can make another + + + align:start position:0% +key goes in my door and can make another +one of those." Um, yeah, we had like + + align:start position:0% +one of those." Um, yeah, we had like + + + align:start position:0% +one of those." Um, yeah, we had like +room inspections a few weeks ago where + + align:start position:0% +room inspections a few weeks ago where + + + align:start position:0% +room inspections a few weeks ago where +they went into every room to check if + + align:start position:0% +they went into every room to check if + + + align:start position:0% +they went into every room to check if +they were abiding by the rules. Yeah. + + align:start position:0% +they were abiding by the rules. Yeah. + + + align:start position:0% +they were abiding by the rules. Yeah. +Good. What um what what might be good + + align:start position:0% +Good. What um what what might be good + + + align:start position:0% +Good. What um what what might be good +about room inspections for everyone? + + align:start position:0% +about room inspections for everyone? + + + align:start position:0% +about room inspections for everyone? +I think Yeah. safety like like you know + + align:start position:0% +I think Yeah. safety like like you know + + + align:start position:0% +I think Yeah. safety like like you know +like if if your if your neighbors are + + align:start position:0% +like if if your if your neighbors are + + + align:start position:0% +like if if your if your neighbors are +like having hallogen lamps that can + + align:start position:0% +like having hallogen lamps that can + + + align:start position:0% +like having hallogen lamps that can +catch on fire and stuff like that like + + align:start position:0% +catch on fire and stuff like that like + + + align:start position:0% +catch on fire and stuff like that like +you would be glad that um they knew + + align:start position:0% +you would be glad that um they knew + + + align:start position:0% +you would be glad that um they knew +about that but obviously also seems like + + align:start position:0% +about that but obviously also seems like + + + align:start position:0% +about that but obviously also seems like +a huge invasion of of your privacy. + + align:start position:0% +a huge invasion of of your privacy. + + + align:start position:0% +a huge invasion of of your privacy. +Yeah, I would I would say like what also + + align:start position:0% +Yeah, I would I would say like what also + + + align:start position:0% +Yeah, I would I would say like what also +like kind of like made the room + + align:start position:0% +like kind of like made the room + + + align:start position:0% +like kind of like made the room +inspections like um good like better + + align:start position:0% +inspections like um good like better + + + align:start position:0% +inspections like um good like better +than like is also like you're trusting + + align:start position:0% +than like is also like you're trusting + + + align:start position:0% +than like is also like you're trusting +MIT to be responsible for this. So like + + align:start position:0% +MIT to be responsible for this. So like + + + align:start position:0% +MIT to be responsible for this. So like +they told they told everyone ahead of + + align:start position:0% +they told they told everyone ahead of + + + align:start position:0% +they told they told everyone ahead of +time and they made sure you know that is + + align:start position:0% +time and they made sure you know that is + + + align:start position:0% +time and they made sure you know that is +it like a visual inspection all so + + align:start position:0% +it like a visual inspection all so + + + align:start position:0% +it like a visual inspection all so +they're not going through your stuff but + + align:start position:0% +they're not going through your stuff but + + + align:start position:0% +they're not going through your stuff but +like obviously that's not a thing for a + + align:start position:0% +like obviously that's not a thing for a + + + align:start position:0% +like obviously that's not a thing for a +lot of colleges a lot of colleges could + + align:start position:0% +lot of colleges a lot of colleges could + + + align:start position:0% +lot of colleges a lot of colleges could +just like come barge into your room and + + align:start position:0% +just like come barge into your room and + + + align:start position:0% +just like come barge into your room and +look at anything. Yeah. So you know + + align:start position:0% +look at anything. Yeah. So you know + + + align:start position:0% +look at anything. Yeah. So you know +institutions make choices about how you + + align:start position:0% +institutions make choices about how you + + + align:start position:0% +institutions make choices about how you +know so I mean hopefully I don't know + + align:start position:0% +know so I mean hopefully I don't know + + + align:start position:0% +know so I mean hopefully I don't know +what what is what kind of feelings do + + align:start position:0% +what what is what kind of feelings do + + + align:start position:0% +what what is what kind of feelings do +you have when you start looking at this + + align:start position:0% +you have when you start looking at this + + + align:start position:0% +you have when you start looking at this +completed list? + + align:start position:0% + + + + align:start position:0% + +Hm. Um the one that like I've been + + align:start position:0% +Hm. Um the one that like I've been + + + align:start position:0% +Hm. Um the one that like I've been +thinking about lately given uh like the + + align:start position:0% +thinking about lately given uh like the + + + align:start position:0% +thinking about lately given uh like the +permanent action stuff is just general + + align:start position:0% +permanent action stuff is just general + + + align:start position:0% +permanent action stuff is just general +demographics. Once you're on campus and + + align:start position:0% +demographics. Once you're on campus and + + + align:start position:0% +demographics. Once you're on campus and +also um something that was not mentioned + + align:start position:0% +also um something that was not mentioned + + + align:start position:0% +also um something that was not mentioned +in financial is like purchase history. + + align:start position:0% +in financial is like purchase history. + + + align:start position:0% +in financial is like purchase history. +So like if you buy anything on campus + + align:start position:0% +So like if you buy anything on campus + + + align:start position:0% +So like if you buy anything on campus +they know you got sushi to make. Yeah. + + align:start position:0% +they know you got sushi to make. Yeah. + + + align:start position:0% +they know you got sushi to make. Yeah. +like Tito and like all like the the + + align:start position:0% +like Tito and like all like the the + + + align:start position:0% +like Tito and like all like the the +coffee stores like in + + align:start position:0% +coffee stores like in + + + align:start position:0% +coffee stores like in +like the ones in like + + align:start position:0% +like the ones in like + + + align:start position:0% +like the ones in like +Forbes stuff like that. Yeah. I mean + + align:start position:0% +Forbes stuff like that. Yeah. I mean + + + align:start position:0% +Forbes stuff like that. Yeah. I mean +particularly if those things somehow go + + align:start position:0% +particularly if those things somehow go + + + align:start position:0% +particularly if those things somehow go +like can you put money on your ID card + + align:start position:0% +like can you put money on your ID card + + + align:start position:0% +like can you put money on your ID card +and spend directly to your ID card. So, + + align:start position:0% +and spend directly to your ID card. So, + + + align:start position:0% +and spend directly to your ID card. So, +you know, there's I mean, like two two + + align:start position:0% +you know, there's I mean, like two two + + + align:start position:0% +you know, there's I mean, like two two +units that we should be thinking about + + align:start position:0% +units that we should be thinking about + + + align:start position:0% +units that we should be thinking about +um anytime we think about school data is + + align:start position:0% +um anytime we think about school data is + + + align:start position:0% +um anytime we think about school data is +that schools have a bunch of data and + + align:start position:0% +that schools have a bunch of data and + + + align:start position:0% +that schools have a bunch of data and +then schools authorize third parties to + + align:start position:0% +then schools authorize third parties to + + + align:start position:0% +then schools authorize third parties to +get a bunch of data and sometimes only + + align:start position:0% +get a bunch of data and sometimes only + + + align:start position:0% +get a bunch of data and sometimes only +the third party has access. Sometimes + + align:start position:0% +the third party has access. Sometimes + + + align:start position:0% +the third party has access. Sometimes +both parties have access like both + + align:start position:0% +both parties have access like both + + + align:start position:0% +both parties have access like both +Canvas and MIT people have access to all + + align:start position:0% +Canvas and MIT people have access to all + + + align:start position:0% +Canvas and MIT people have access to all +of your Canvas data. you know, the + + align:start position:0% +of your Canvas data. you know, the + + + align:start position:0% +of your Canvas data. you know, the +laundry app might be a good example of + + align:start position:0% +laundry app might be a good example of + + + align:start position:0% +laundry app might be a good example of +if nobody I mean, if somebody told me + + align:start position:0% +if nobody I mean, if somebody told me + + + align:start position:0% +if nobody I mean, if somebody told me +that the maintenance department had + + align:start position:0% +that the maintenance department had + + + align:start position:0% +that the maintenance department had +access to all the laundry data or it I + + align:start position:0% +access to all the laundry data or it I + + + align:start position:0% +access to all the laundry data or it I +wouldn't be surprised, but if they were + + align:start position:0% +wouldn't be surprised, but if they were + + + align:start position:0% +wouldn't be surprised, but if they were +like, "Yeah, no, we make you sign up + + align:start position:0% +like, "Yeah, no, we make you sign up + + + align:start position:0% +like, "Yeah, no, we make you sign up +with an email, but you know, only the + + align:start position:0% +with an email, but you know, only the + + + align:start position:0% +with an email, but you know, only the +laundry people know your laundry data," + + align:start position:0% +laundry people know your laundry data," + + + align:start position:0% +laundry people know your laundry data," +that wouldn't surprise me either. Um, + + align:start position:0% +that wouldn't surprise me either. Um, + + + align:start position:0% +that wouldn't surprise me either. Um, +but those are sort of two useful salient + + align:start position:0% +but those are sort of two useful salient + + + align:start position:0% +but those are sort of two useful salient +categories that will come up as we keep + + align:start position:0% +categories that will come up as we keep + + + align:start position:0% +categories that will come up as we keep +talking about things. + + align:start position:0% +talking about things. + + + align:start position:0% +talking about things. +Your deliveries, too. Oh, yeah. + + align:start position:0% +Your deliveries, too. Oh, yeah. + + + align:start position:0% +Your deliveries, too. Oh, yeah. +Deliveries. Um, oh, because things go + + align:start position:0% +Deliveries. Um, oh, because things go + + + align:start position:0% +Deliveries. Um, oh, because things go +through the mail room. Yeah. So, um they + + align:start position:0% +through the mail room. Yeah. So, um they + + + align:start position:0% +through the mail room. Yeah. So, um they +have uh they like store all of your + + align:start position:0% +have uh they like store all of your + + + align:start position:0% +have uh they like store all of your +information and your deliveries into + + align:start position:0% +information and your deliveries into + + + align:start position:0% +information and your deliveries into +like a tracker system and then they send + + align:start position:0% +like a tracker system and then they send + + + align:start position:0% +like a tracker system and then they send +you emails when your delivery is coming + + align:start position:0% +you emails when your delivery is coming + + + align:start position:0% +you emails when your delivery is coming +if you didn't pick it up. Good. Yeah. + + align:start position:0% +if you didn't pick it up. Good. Yeah. + + + align:start position:0% +if you didn't pick it up. Good. Yeah. +And so there's, you know, typic + + align:start position:0% +And so there's, you know, typic + + + align:start position:0% +And so there's, you know, typic +typically the data is exchanged for some + + align:start position:0% +typically the data is exchanged for some + + + align:start position:0% +typically the data is exchanged for some +kind of service. You're like want to + + align:start position:0% +kind of service. You're like want to + + + align:start position:0% +kind of service. You're like want to +know when your new headphones are coming + + align:start position:0% +know when your new headphones are coming + + + align:start position:0% +know when your new headphones are coming +or something like that. And so you're + + align:start position:0% +or something like that. And so you're + + + align:start position:0% +or something like that. And so you're +glad that they have that, but in order + + align:start position:0% +glad that they have that, but in order + + + align:start position:0% +glad that they have that, but in order +for them to be able to know when your + + align:start position:0% +for them to be able to know when your + + + align:start position:0% +for them to be able to know when your +new headphones are coming and to do + + align:start position:0% +new headphones are coming and to do + + + align:start position:0% +new headphones are coming and to do +other kinds of things with it, you know. + + align:start position:0% +other kinds of things with it, you know. + + + align:start position:0% +other kinds of things with it, you know. +I mean, the other thing it's like you + + align:start position:0% +I mean, the other thing it's like you + + + align:start position:0% +I mean, the other thing it's like you +say like, you know, over the past 10 + + align:start position:0% +say like, you know, over the past 10 + + + align:start position:0% +say like, you know, over the past 10 +years, was it a good idea for MIT to + + align:start position:0% +years, was it a good idea for MIT to + + + align:start position:0% +years, was it a good idea for MIT to +track the changing volume of deliveries + + align:start position:0% +track the changing volume of deliveries + + + align:start position:0% +track the changing volume of deliveries +to individual students? Like yes. Like + + align:start position:0% +to individual students? Like yes. Like + + + align:start position:0% +to individual students? Like yes. Like +I'm sure MIT has had to build all kinds + + align:start position:0% +I'm sure MIT has had to build all kinds + + + align:start position:0% +I'm sure MIT has had to build all kinds +of infrastructure to make it possible + + align:start position:0% +of infrastructure to make it possible + + + align:start position:0% +of infrastructure to make it possible +for you all to get your stuff in a + + align:start position:0% +for you all to get your stuff in a + + + align:start position:0% +for you all to get your stuff in a +sensible way and it's probably a good + + align:start position:0% +sensible way and it's probably a good + + + align:start position:0% +sensible way and it's probably a good +idea that MIT has data about aggregate + + align:start position:0% +idea that MIT has data about aggregate + + + align:start position:0% +idea that MIT has data about aggregate +you know partic particularly in the + + align:start position:0% +you know partic particularly in the + + + align:start position:0% +you know partic particularly in the +aggregate it's probably a good idea to + + align:start position:0% +aggregate it's probably a good idea to + + + align:start position:0% +aggregate it's probably a good idea to +know like oh you know in in 2014 um the + + align:start position:0% +know like oh you know in in 2014 um the + + + align:start position:0% +know like oh you know in in 2014 um the +typical student got you know 2.3 + + align:start position:0% +typical student got you know 2.3 + + + align:start position:0% +typical student got you know 2.3 +packages a year and now they get 30.6 + + align:start position:0% +packages a year and now they get 30.6 + + + align:start position:0% +packages a year and now they get 30.6 +packages per year and you know like just + + align:start position:0% +packages per year and you know like just + + + align:start position:0% +packages per year and you know like just +requires a whole different + + align:start position:0% +requires a whole different + + + align:start position:0% +requires a whole different +infrastructure to support those two + + align:start position:0% +infrastructure to support those two + + + align:start position:0% +infrastructure to support those two +kinds of ways of people doing commerce. + + align:start position:0% +kinds of ways of people doing commerce. + + + align:start position:0% +kinds of ways of people doing commerce. +Um, any what other feelings do you have + + align:start position:0% +Um, any what other feelings do you have + + + align:start position:0% +Um, any what other feelings do you have +as you look at like the whole at the + + align:start position:0% +as you look at like the whole at the + + + align:start position:0% +as you look at like the whole at the +whole list of data that MIT might have + + align:start position:0% +whole list of data that MIT might have + + + align:start position:0% +whole list of data that MIT might have +about you? + + align:start position:0% +about you? + + + align:start position:0% +about you? +Feel like ultimately I'm not really that + + align:start position:0% +Feel like ultimately I'm not really that + + + align:start position:0% +Feel like ultimately I'm not really that +surprised. I feel like we kind of grew + + align:start position:0% +surprised. I feel like we kind of grew + + + align:start position:0% +surprised. I feel like we kind of grew +up in a generation where like digital + + align:start position:0% +up in a generation where like digital + + + align:start position:0% +up in a generation where like digital +data has been collected for our entire + + align:start position:0% +data has been collected for our entire + + + align:start position:0% +data has been collected for our entire +lives. Like it was not something that + + align:start position:0% +lives. Like it was not something that + + + align:start position:0% +lives. Like it was not something that +was introduced but always there. And so + + align:start position:0% +was introduced but always there. And so + + + align:start position:0% +was introduced but always there. And so +like I feel like I've kind of grown up + + align:start position:0% +like I feel like I've kind of grown up + + + align:start position:0% +like I feel like I've kind of grown up +in this world knowing that all of this + + align:start position:0% +in this world knowing that all of this + + + align:start position:0% +in this world knowing that all of this +type of information can and is being + + align:start position:0% +type of information can and is being + + + align:start position:0% +type of information can and is being +collected on me. And so like I'm still + + align:start position:0% +collected on me. And so like I'm still + + + align:start position:0% +collected on me. And so like I'm still +gonna like live the same way, but I just + + align:start position:0% +gonna like live the same way, but I just + + + align:start position:0% +gonna like live the same way, but I just +like it just is what it is in like a + + align:start position:0% +like it just is what it is in like a + + + align:start position:0% +like it just is what it is in like a +kind of sad way. Yeah. Yeah. There's + + align:start position:0% +kind of sad way. Yeah. Yeah. There's + + + align:start position:0% +kind of sad way. Yeah. Yeah. There's +sort of sag, you know, it's not um + + align:start position:0% +sort of sag, you know, it's not um + + + align:start position:0% +sort of sag, you know, it's not um +you're clearly not comfortable with it + + align:start position:0% +you're clearly not comfortable with it + + + align:start position:0% +you're clearly not comfortable with it +because if you listen to to pe if like + + align:start position:0% +because if you listen to to pe if like + + + align:start position:0% +because if you listen to to pe if like +if you stop talking for a second while + + align:start position:0% +if you stop talking for a second while + + + align:start position:0% +if you stop talking for a second while +people were making the listen listen, + + align:start position:0% +people were making the listen listen, + + + align:start position:0% +people were making the listen listen, +there's like all kinds of awkward + + align:start position:0% +there's like all kinds of awkward + + + align:start position:0% +there's like all kinds of awkward +laughter that happens throughout the + + align:start position:0% +laughter that happens throughout the + + + align:start position:0% +laughter that happens throughout the +whole time. There's something about this + + align:start position:0% +whole time. There's something about this + + + align:start position:0% +whole time. There's something about this +which is like, oh, this doesn't feel + + align:start position:0% +which is like, oh, this doesn't feel + + + align:start position:0% +which is like, oh, this doesn't feel +good. Like like any individual category + + align:start position:0% +good. Like like any individual category + + + align:start position:0% +good. Like like any individual category +can make you not feel that great. like + + align:start position:0% +can make you not feel that great. like + + + align:start position:0% +can make you not feel that great. like +like do you really want MIT's IT + + align:start position:0% +like do you really want MIT's IT + + + align:start position:0% +like do you really want MIT's IT +department to be able to track where + + align:start position:0% +department to be able to track where + + + align:start position:0% +department to be able to track where +everyone can go? Like that seems like it + + align:start position:0% +everyone can go? Like that seems like it + + + align:start position:0% +everyone can go? Like that seems like it +could go ary. Um and then just like the + + align:start position:0% +could go ary. Um and then just like the + + + align:start position:0% +could go ary. Um and then just like the +whole you know the whole volume in a in + + align:start position:0% +whole you know the whole volume in a in + + + align:start position:0% +whole you know the whole volume in a in +aggregate you realize like how you know + + align:start position:0% +aggregate you realize like how you know + + + align:start position:0% +aggregate you realize like how you know +how much school you could make a very + + align:start position:0% +how much school you could make a very + + + align:start position:0% +how much school you could make a very +similar list for K12 schools as well. + + align:start position:0% +similar list for K12 schools as well. + + + align:start position:0% +similar list for K12 schools as well. +You can probably guess the places in + + align:start position:0% +You can probably guess the places in + + + align:start position:0% +You can probably guess the places in +which things are not exactly the same + + align:start position:0% +which things are not exactly the same + + + align:start position:0% +which things are not exactly the same +but um uh you know um and and the data + + align:start position:0% +but um uh you know um and and the data + + + align:start position:0% +but um uh you know um and and the data +collection that people can do can be + + align:start position:0% +collection that people can do can be + + + align:start position:0% +collection that people can do can be +really influenced by policy. you know, + + align:start position:0% +really influenced by policy. you know, + + + align:start position:0% +really influenced by policy. you know, +the states have different rules about + + align:start position:0% +the states have different rules about + + + align:start position:0% +the states have different rules about +how attendance is connected to funding. + + align:start position:0% +how attendance is connected to funding. + + + align:start position:0% +how attendance is connected to funding. +Um, who's there on a particular day, + + align:start position:0% +Um, who's there on a particular day, + + + align:start position:0% +Um, who's there on a particular day, +who's there for what periods of time? + + align:start position:0% +who's there for what periods of time? + + + align:start position:0% +who's there for what periods of time? +Um, you know, you could imagine that you + + align:start position:0% +Um, you know, you could imagine that you + + + align:start position:0% +Um, you know, you could imagine that you +want to make sure that if a kid moves + + align:start position:0% +want to make sure that if a kid moves + + + align:start position:0% +want to make sure that if a kid moves +schools three times in a school year, + + align:start position:0% +schools three times in a school year, + + + align:start position:0% +schools three times in a school year, +that not all three of those schools get + + align:start position:0% +that not all three of those schools get + + + align:start position:0% +that not all three of those schools get +like a full students tuition worth of uh + + align:start position:0% +like a full students tuition worth of uh + + + align:start position:0% +like a full students tuition worth of uh +or you know, a student per pupil + + align:start position:0% +or you know, a student per pupil + + + align:start position:0% +or you know, a student per pupil +expenditure. Um so but there are states + + align:start position:0% +expenditure. Um so but there are states + + + align:start position:0% +expenditure. Um so but there are states +that you know part of the reason why + + align:start position:0% +that you know part of the reason why + + + align:start position:0% +that you know part of the reason why +they issue ID cards to students and + + align:start position:0% +they issue ID cards to students and + + + align:start position:0% +they issue ID cards to students and +track their entrance and things like + + align:start position:0% +track their entrance and things like + + + align:start position:0% +track their entrance and things like +that is to pay really close attention to + + align:start position:0% +that is to pay really close attention to + + + align:start position:0% +that is to pay really close attention to +that attendance data um just for that + + align:start position:0% +that attendance data um just for that + + + align:start position:0% +that attendance data um just for that +particular policy purpose. + + align:start position:0% +particular policy purpose. + + + align:start position:0% +particular policy purpose. +Um yeah I mean adding on to like it + + align:start position:0% +Um yeah I mean adding on to like it + + + align:start position:0% +Um yeah I mean adding on to like it +being not surprising I would say like a + + align:start position:0% +being not surprising I would say like a + + + align:start position:0% +being not surprising I would say like a +lot of the information that like like + + align:start position:0% +lot of the information that like like + + + align:start position:0% +lot of the information that like like +they took while we were here like our + + align:start position:0% +they took while we were here like our + + + align:start position:0% +they took while we were here like our +like current residence or laundry and + + align:start position:0% +like current residence or laundry and + + + align:start position:0% +like current residence or laundry and +stuff like that. It's I feel like it's + + align:start position:0% +stuff like that. It's I feel like it's + + + align:start position:0% +stuff like that. It's I feel like it's +kind of like much more unsurprising just + + align:start position:0% +kind of like much more unsurprising just + + + align:start position:0% +kind of like much more unsurprising just +because like it is something that is + + align:start position:0% +because like it is something that is + + + align:start position:0% +because like it is something that is +like novel when you come to like a + + align:start position:0% +like novel when you come to like a + + + align:start position:0% +like novel when you come to like a +college or like an institution like this + + align:start position:0% +college or like an institution like this + + + align:start position:0% +college or like an institution like this +where it's like oh wow like they really + + align:start position:0% +where it's like oh wow like they really + + + align:start position:0% +where it's like oh wow like they really +do have this information. Um but I think + + align:start position:0% +do have this information. Um but I think + + + align:start position:0% +do have this information. Um but I think +what's kind of um a little crazy is how + + align:start position:0% +what's kind of um a little crazy is how + + + align:start position:0% +what's kind of um a little crazy is how +much of this information they have + + align:start position:0% +much of this information they have + + + align:start position:0% +much of this information they have +before you even get here. + + align:start position:0% +before you even get here. + + + align:start position:0% +before you even get here. +So yeah, for applicants, for for people + + align:start position:0% +So yeah, for applicants, for for people + + + align:start position:0% +So yeah, for applicants, for for people +who are admitted, if you're admitted + + align:start position:0% +who are admitted, if you're admitted + + + align:start position:0% +who are admitted, if you're admitted +into the school and things like that, + + align:start position:0% +into the school and things like that, + + + align:start position:0% +into the school and things like that, +yeah, there's a lot that you need to + + align:start position:0% +yeah, there's a lot that you need to + + + align:start position:0% +yeah, there's a lot that you need to +tell MIT for them to be able to to come + + align:start position:0% +tell MIT for them to be able to to come + + + align:start position:0% +tell MIT for them to be able to to come +here and get here. There's a there's a + + align:start position:0% +here and get here. There's a there's a + + + align:start position:0% +here and get here. There's a there's a +lot that you need to be able to um you + + align:start position:0% +lot that you need to be able to um you + + + align:start position:0% +lot that you need to be able to um you +know, uh the if you to get in again + + align:start position:0% +know, uh the if you to get in again + + + align:start position:0% +know, uh the if you to get in again +these days, you have to take the SAT, + + align:start position:0% +these days, you have to take the SAT, + + + align:start position:0% +these days, you have to take the SAT, +which means you give, you know, you are + + align:start position:0% +which means you give, you know, you are + + + align:start position:0% +which means you give, you know, you are +required to give a bunch of information + + align:start position:0% +required to give a bunch of information + + + align:start position:0% +required to give a bunch of information +to the College Board. Um and you also + + align:start position:0% +to the College Board. Um and you also + + + align:start position:0% +to the College Board. Um and you also +like are in the process of doing that, + + align:start position:0% +like are in the process of doing that, + + + align:start position:0% +like are in the process of doing that, +you're probably asked to opt in to a + + align:start position:0% +you're probably asked to opt in to a + + + align:start position:0% +you're probably asked to opt in to a +bunch of things. I had I had a master's + + align:start position:0% +bunch of things. I had I had a master's + + + align:start position:0% +bunch of things. I had I had a master's +student I can't remember all the details + + align:start position:0% +student I can't remember all the details + + + align:start position:0% +student I can't remember all the details +now but uh um did their thesis on + + align:start position:0% +now but uh um did their thesis on + + + align:start position:0% +now but uh um did their thesis on +essentially the kinds of things that the + + align:start position:0% +essentially the kinds of things that the + + + align:start position:0% +essentially the kinds of things that the +college board did with information that + + align:start position:0% +college board did with information that + + + align:start position:0% +college board did with information that +they got um which to some extent you + + align:start position:0% +they got um which to some extent you + + + align:start position:0% +they got um which to some extent you +could say something like like if you opt + + align:start position:0% +could say something like like if you opt + + + align:start position:0% +could say something like like if you opt +into flowers.com or something like that + + align:start position:0% +into flowers.com or something like that + + + align:start position:0% +into flowers.com or something like that +you're like man I really want good + + align:start position:0% +you're like man I really want good + + + align:start position:0% +you're like man I really want good +information about what flowers are + + align:start position:0% +information about what flowers are + + + align:start position:0% +information about what flowers are +available and then flowers.com sells + + align:start position:0% +available and then flowers.com sells + + + align:start position:0% +available and then flowers.com sells +your data you're like well that's like + + align:start position:0% +your data you're like well that's like + + + align:start position:0% +your data you're like well that's like +maybe that's a terrible system to exist + + align:start position:0% +maybe that's a terrible system to exist + + + align:start position:0% +maybe that's a terrible system to exist +in um but flowers.com did ask me if I + + align:start position:0% +in um but flowers.com did ask me if I + + + align:start position:0% +in um but flowers.com did ask me if I +wanted to give them my data and I did + + align:start position:0% +wanted to give them my data and I did + + + align:start position:0% +wanted to give them my data and I did +agree to let them do anything with it. + + align:start position:0% +agree to let them do anything with it. + + + align:start position:0% +agree to let them do anything with it. +So like I you know and that was just my + + align:start position:0% +So like I you know and that was just my + + + align:start position:0% +So like I you know and that was just my +voluntary relationship but you didn't + + align:start position:0% +voluntary relationship but you didn't + + + align:start position:0% +voluntary relationship but you didn't +really have a voluntary relationship + + align:start position:0% +really have a voluntary relationship + + + align:start position:0% +really have a voluntary relationship +with the college board. Um you know you + + align:start position:0% +with the college board. Um you know you + + + align:start position:0% +with the college board. Um you know you +had no choice but to interact with a + + align:start position:0% +had no choice but to interact with a + + + align:start position:0% +had no choice but to interact with a +college board to make it through this + + align:start position:0% +college board to make it through this + + + align:start position:0% +college board to make it through this +major life milestone. And so to you know + + align:start position:0% +major life milestone. And so to you know + + + align:start position:0% +major life milestone. And so to you know +to the extent that the college board + + align:start position:0% +to the extent that the college board + + + align:start position:0% +to the extent that the college board +does things with your information that's + + align:start position:0% +does things with your information that's + + + align:start position:0% +does things with your information that's +a different relationship um that you + + align:start position:0% +a different relationship um that you + + + align:start position:0% +a different relationship um that you +have with them than you have with + + align:start position:0% +have with them than you have with + + + align:start position:0% +have with them than you have with +flowers.com or pets.com or your own + + align:start position:0% +flowers.com or pets.com or your own + + + align:start position:0% +flowers.com or pets.com or your own +favorite thing. Um, okay. So, we just we + + align:start position:0% +favorite thing. Um, okay. So, we just we + + + align:start position:0% +favorite thing. Um, okay. So, we just we +live in a world in which schools have + + align:start position:0% +live in a world in which schools have + + + align:start position:0% +live in a world in which schools have +enormous amounts of individ + + align:start position:0% +enormous amounts of individ + + + align:start position:0% +enormous amounts of individ +um about their individual students. Um, + + align:start position:0% +um about their individual students. Um, + + + align:start position:0% +um about their individual students. Um, +that there's probably pretty big + + align:start position:0% +that there's probably pretty big + + + align:start position:0% +that there's probably pretty big +generational shifts in that experience. + + align:start position:0% +generational shifts in that experience. + + + align:start position:0% +generational shifts in that experience. +You know, one of the main laws that + + align:start position:0% +You know, one of the main laws that + + + align:start position:0% +You know, one of the main laws that +governs um these records is the federal + + align:start position:0% +governs um these records is the federal + + + align:start position:0% +governs um these records is the federal +furpa, the federal education records + + align:start position:0% +furpa, the federal education records + + + align:start position:0% +furpa, the federal education records +protection act, which I think was off + + align:start position:0% +protection act, which I think was off + + + align:start position:0% +protection act, which I think was off +authored in the 1970s. um you know the + + align:start position:0% +authored in the 1970s. um you know the + + + align:start position:0% +authored in the 1970s. um you know the +kind like we basically we have a legal + + align:start position:0% +kind like we basically we have a legal + + + align:start position:0% +kind like we basically we have a legal +framework for supervising this data um + + align:start position:0% +framework for supervising this data um + + + align:start position:0% +framework for supervising this data um +which was just built in an entirely + + align:start position:0% +which was just built in an entirely + + + align:start position:0% +which was just built in an entirely +different era um you know um furo refers + + align:start position:0% +different era um you know um furo refers + + + align:start position:0% +different era um you know um furo refers +to this thing called student records um + + align:start position:0% +to this thing called student records um + + + align:start position:0% +to this thing called student records um +at the time it would have been entire it + + align:start position:0% +at the time it would have been entire it + + + align:start position:0% +at the time it would have been entire it +would have been very very clear what a + + align:start position:0% +would have been very very clear what a + + + align:start position:0% +would have been very very clear what a +student record was you would have like + + align:start position:0% +student record was you would have like + + + align:start position:0% +student record was you would have like +gone to the registars's office and there + + align:start position:0% +gone to the registars's office and there + + + align:start position:0% +gone to the registars's office and there +would have been like big file drawers + + align:start position:0% +would have been like big file drawers + + + align:start position:0% +would have been like big file drawers +and you would have pulled out a file and + + align:start position:0% +and you would have pulled out a file and + + + align:start position:0% +and you would have pulled out a file and +been like that is the student record um + + align:start position:0% +been like that is the student record um + + + align:start position:0% +been like that is the student record um +are your clicker questions part of your + + align:start position:0% +are your clicker questions part of your + + + align:start position:0% +are your clicker questions part of your +student record are your um codio + + align:start position:0% +student record are your um codio + + + align:start position:0% +student record are your um codio +assignments, are your Canvas entries, + + align:start position:0% +assignments, are your Canvas entries, + + + align:start position:0% +assignments, are your Canvas entries, +are your, you know, Piaza form things + + align:start position:0% +are your, you know, Piaza form things + + + align:start position:0% +are your, you know, Piaza form things +like are those part of your student + + align:start position:0% +like are those part of your student + + + align:start position:0% +like are those part of your student +records? Like there, you know, there's + + align:start position:0% +records? Like there, you know, there's + + + align:start position:0% +records? Like there, you know, there's +there's much less clarity over those + + align:start position:0% +there's much less clarity over those + + + align:start position:0% +there's much less clarity over those +things um than one might think. + + align:start position:0% +things um than one might think. + + + align:start position:0% +things um than one might think. +Um the uh + + align:start position:0% + + + + align:start position:0% + +um the term the term toxic has a kind of + + align:start position:0% +um the term the term toxic has a kind of + + + align:start position:0% +um the term the term toxic has a kind of +negative connotation, but I borrowed it + + align:start position:0% +negative connotation, but I borrowed it + + + align:start position:0% +negative connotation, but I borrowed it +from a security researcher named Bruce + + align:start position:0% +from a security researcher named Bruce + + + align:start position:0% +from a security researcher named Bruce +Shire. Um, and part of his argument was + + align:start position:0% +Shire. Um, and part of his argument was + + + align:start position:0% +Shire. Um, and part of his argument was +that like toxic things are powerful. Um, + + align:start position:0% +that like toxic things are powerful. Um, + + + align:start position:0% +that like toxic things are powerful. Um, +you know, there there are, you know, + + align:start position:0% +you know, there there are, you know, + + + align:start position:0% +you know, there there are, you know, +chemotherapies are toxic. Um, and they + + align:start position:0% +chemotherapies are toxic. Um, and they + + + align:start position:0% +chemotherapies are toxic. Um, and they +save your life. They're great. Like like + + align:start position:0% +save your life. They're great. Like like + + + align:start position:0% +save your life. They're great. Like like +sometimes it's really good to interact + + align:start position:0% +sometimes it's really good to interact + + + align:start position:0% +sometimes it's really good to interact +with powerful toxic things. Um, but + + align:start position:0% +with powerful toxic things. Um, but + + + align:start position:0% +with powerful toxic things. Um, but +toxic things are also dangerous. Um, in + + align:start position:0% +toxic things are also dangerous. Um, in + + + align:start position:0% +toxic things are also dangerous. Um, in +you know, in particular, I think most of + + align:start position:0% +you know, in particular, I think most of + + + align:start position:0% +you know, in particular, I think most of +us have an inclination um that when + + align:start position:0% +us have an inclination um that when + + + align:start position:0% +us have an inclination um that when +something is toxic, you should not leave + + align:start position:0% +something is toxic, you should not leave + + + align:start position:0% +something is toxic, you should not leave +it lying around for a long period of + + align:start position:0% +it lying around for a long period of + + + align:start position:0% +it lying around for a long period of +time. That was kind of the heart of + + align:start position:0% +time. That was kind of the heart of + + + align:start position:0% +time. That was kind of the heart of +Bruce's argument was was that companies + + align:start position:0% +Bruce's argument was was that companies + + + align:start position:0% +Bruce's argument was was that companies +were making a big mistake by having um + + align:start position:0% +were making a big mistake by having um + + + align:start position:0% +were making a big mistake by having um +by having a a a very capacious approach + + align:start position:0% +by having a a a very capacious approach + + + align:start position:0% +by having a a a very capacious approach +to the collection and storage of data. + + align:start position:0% +to the collection and storage of data. + + + align:start position:0% +to the collection and storage of data. +Um that actually what you should be + + align:start position:0% +Um that actually what you should be + + + align:start position:0% +Um that actually what you should be +doing is like just taking the data you + + align:start position:0% +doing is like just taking the data you + + + align:start position:0% +doing is like just taking the data you +need and getting rid of the rest of it + + align:start position:0% +need and getting rid of the rest of it + + + align:start position:0% +need and getting rid of the rest of it +because it's a toxic asset to have lying + + align:start position:0% +because it's a toxic asset to have lying + + + align:start position:0% +because it's a toxic asset to have lying +around. The more you have it lying + + align:start position:0% +around. The more you have it lying + + + align:start position:0% +around. The more you have it lying +around, the more you're vulnerable to + + align:start position:0% +around, the more you're vulnerable to + + + align:start position:0% +around, the more you're vulnerable to +breaches, to other kinds of actors doing + + align:start position:0% +breaches, to other kinds of actors doing + + + align:start position:0% +breaches, to other kinds of actors doing +various nefarious things um with that + + align:start position:0% +various nefarious things um with that + + + align:start position:0% +various nefarious things um with that +data. + + align:start position:0% +data. + + + align:start position:0% +data. +Um, if you're an educational + + align:start position:0% +Um, if you're an educational + + + align:start position:0% +Um, if you're an educational +researcher, what what what kinds of + + align:start position:0% +researcher, what what what kinds of + + + align:start position:0% +researcher, what what what kinds of +thoughts might you have when you see + + align:start position:0% +thoughts might you have when you see + + + align:start position:0% +thoughts might you have when you see +this like giant list of the data that + + align:start position:0% +this like giant list of the data that + + + align:start position:0% +this like giant list of the data that +schools collect about people? + + align:start position:0% + + + + align:start position:0% + +Maybe like honestly like the first thing + + align:start position:0% +Maybe like honestly like the first thing + + + align:start position:0% +Maybe like honestly like the first thing +that kind of came to my mind was like + + align:start position:0% +that kind of came to my mind was like + + + align:start position:0% +that kind of came to my mind was like +excitement in the sense of like if + + align:start position:0% +excitement in the sense of like if + + + align:start position:0% +excitement in the sense of like if +you're forming any type of research and + + align:start position:0% +you're forming any type of research and + + + align:start position:0% +you're forming any type of research and +trying to study how any about a person + + align:start position:0% +trying to study how any about a person + + + align:start position:0% +trying to study how any about a person +can like affect whatever you're studying + + align:start position:0% +can like affect whatever you're studying + + + align:start position:0% +can like affect whatever you're studying +like if you have all of this data then + + align:start position:0% +like if you have all of this data then + + + align:start position:0% +like if you have all of this data then +like there's really no limit to what + + align:start position:0% +like there's really no limit to what + + + align:start position:0% +like there's really no limit to what +you're able to um kind of research. Um + + align:start position:0% +you're able to um kind of research. Um + + + align:start position:0% +you're able to um kind of research. Um +this was an article from today two days + + align:start position:0% +this was an article from today two days + + + align:start position:0% +this was an article from today two days +ago. I'm going to give you a couple of + + align:start position:0% +ago. I'm going to give you a couple of + + + align:start position:0% +ago. I'm going to give you a couple of +cutting edge things. Middle schools in + + align:start position:0% +cutting edge things. Middle schools in + + + align:start position:0% +cutting edge things. Middle schools in +Norway banned smartphones. The benefits + + align:start position:0% +Norway banned smartphones. The benefits + + + align:start position:0% +Norway banned smartphones. The benefits +were dramatic. A study shows um a study + + align:start position:0% +were dramatic. A study shows um a study + + + align:start position:0% +were dramatic. A study shows um a study +published earlier this year um from a + + align:start position:0% +published earlier this year um from a + + + align:start position:0% +published earlier this year um from a +Norwegian doctoral student. Um where + + align:start position:0% +Norwegian doctoral student. Um where + + + align:start position:0% +Norwegian doctoral student. Um where +there were hundreds of schools across + + align:start position:0% +there were hundreds of schools across + + + align:start position:0% +there were hundreds of schools across +Norway that it um that in various ways + + align:start position:0% +Norway that it um that in various ways + + + align:start position:0% +Norway that it um that in various ways +banned smartphones. Um some of the + + align:start position:0% +banned smartphones. Um some of the + + + align:start position:0% +banned smartphones. Um some of the +outcomes they look at are student + + align:start position:0% +outcomes they look at are student + + + align:start position:0% +outcomes they look at are student +outcomes like learning but also mental + + align:start position:0% +outcomes like learning but also mental + + + align:start position:0% +outcomes like learning but also mental +health. Um, I show that banning + + align:start position:0% +health. Um, I show that banning + + + align:start position:0% +health. Um, I show that banning +smartphones significantly decreases the + + align:start position:0% +smartphones significantly decreases the + + + align:start position:0% +smartphones significantly decreases the +health care takeup for psychological + + align:start position:0% +health care takeup for psychological + + + align:start position:0% +health care takeup for psychological +symptoms and diseases among girls. + + align:start position:0% +symptoms and diseases among girls. + + + align:start position:0% +symptoms and diseases among girls. +Postban bullying among both genders + + align:start position:0% +Postban bullying among both genders + + + align:start position:0% +Postban bullying among both genders +decreases. Girls GPA improves and their + + align:start position:0% +decreases. Girls GPA improves and their + + + align:start position:0% +decreases. Girls GPA improves and their +likelihood of attending an academic high + + align:start position:0% +likelihood of attending an academic high + + + align:start position:0% +likelihood of attending an academic high +school track increases. These effects + + align:start position:0% +school track increases. These effects + + + align:start position:0% +school track increases. These effects +are larger from girls from so from low + + align:start position:0% +are larger from girls from so from low + + + align:start position:0% +are larger from girls from so from low +socioeconomic backgrounds. Um, so in + + align:start position:0% +socioeconomic backgrounds. Um, so in + + + align:start position:0% +socioeconomic backgrounds. Um, so in +Norway they have vast informations about + + align:start position:0% +Norway they have vast informations about + + + align:start position:0% +Norway they have vast informations about +students. Here are some things that you + + align:start position:0% +students. Here are some things that you + + + align:start position:0% +students. Here are some things that you +need to know to make this study work. + + align:start position:0% +need to know to make this study work. + + + align:start position:0% +need to know to make this study work. +You need to know all the students + + align:start position:0% +You need to know all the students + + + align:start position:0% +You need to know all the students +grades. You need to know where all the + + align:start position:0% +grades. You need to know where all the + + + align:start position:0% +grades. You need to know where all the +students go to college. You need to know + + align:start position:0% +students go to college. You need to know + + + align:start position:0% +students go to college. You need to know +whenever the students visit the uh + + align:start position:0% +whenever the students visit the uh + + + align:start position:0% +whenever the students visit the uh +Norwegian health care system and what + + align:start position:0% +Norwegian health care system and what + + + align:start position:0% +Norwegian health care system and what +kinds of requests they're making from + + align:start position:0% +kinds of requests they're making from + + + align:start position:0% +kinds of requests they're making from +the Norwegian health care system. Uh and + + align:start position:0% +the Norwegian health care system. Uh and + + + align:start position:0% +the Norwegian health care system. Uh and +you need to have them every year take a + + align:start position:0% +you need to have them every year take a + + + align:start position:0% +you need to have them every year take a +well-being survey that includes a bunch + + align:start position:0% +well-being survey that includes a bunch + + + align:start position:0% +well-being survey that includes a bunch +of questions about bullying. Like that's + + align:start position:0% +of questions about bullying. Like that's + + + align:start position:0% +of questions about bullying. Like that's +a lot of information for the state to + + align:start position:0% +a lot of information for the state to + + + align:start position:0% +a lot of information for the state to +collect about all these students. But it + + align:start position:0% +collect about all these students. But it + + + align:start position:0% +collect about all these students. But it +certainly seems to me like a pretty + + align:start position:0% +certainly seems to me like a pretty + + + align:start position:0% +certainly seems to me like a pretty +pro-social thing to be able to say, + + align:start position:0% +pro-social thing to be able to say, + + + align:start position:0% +pro-social thing to be able to say, +"Hey, you know, if we, you know, if we + + align:start position:0% +"Hey, you know, if we, you know, if we + + + align:start position:0% +"Hey, you know, if we, you know, if we +look at the schools that ban um + + align:start position:0% +look at the schools that ban um + + + align:start position:0% +look at the schools that ban um +smartphones in middle school versus the + + align:start position:0% +smartphones in middle school versus the + + + align:start position:0% +smartphones in middle school versus the +ones that don't, um there seem to be all + + align:start position:0% +ones that don't, um there seem to be all + + + align:start position:0% +ones that don't, um there seem to be all +of these health outcomes." And we can + + align:start position:0% +of these health outcomes." And we can + + + align:start position:0% +of these health outcomes." And we can +even actually say that the you know, the + + align:start position:0% +even actually say that the you know, the + + + align:start position:0% +even actually say that the you know, the +health, it's not just academic outcomes, + + align:start position:0% +health, it's not just academic outcomes, + + + align:start position:0% +health, it's not just academic outcomes, +it's also health outcomes, although the + + align:start position:0% +it's also health outcomes, although the + + + align:start position:0% +it's also health outcomes, although the +health outcomes are probably related in + + align:start position:0% +health outcomes are probably related in + + + align:start position:0% +health outcomes are probably related in +some way to the academic outcomes, but + + align:start position:0% +some way to the academic outcomes, but + + + align:start position:0% +some way to the academic outcomes, but +it's particularly for girls and it's + + align:start position:0% +it's particularly for girls and it's + + + align:start position:0% +it's particularly for girls and it's +particularly for um students in low + + align:start position:0% +particularly for um students in low + + + align:start position:0% +particularly for um students in low +socioeconomic environments. like that + + align:start position:0% +socioeconomic environments. like that + + + align:start position:0% +socioeconomic environments. like that +seems like pretty useful stuff to know. + + align:start position:0% +seems like pretty useful stuff to know. + + + align:start position:0% +seems like pretty useful stuff to know. +Um and so that is the kind of tradeoff + + align:start position:0% +Um and so that is the kind of tradeoff + + + align:start position:0% +Um and so that is the kind of tradeoff +that people would face as they're going + + align:start position:0% +that people would face as they're going + + + align:start position:0% +that people would face as they're going +back and forth between um you know these + + align:start position:0% +back and forth between um you know these + + + align:start position:0% +back and forth between um you know these +like the the massive data that we + + align:start position:0% +like the the massive data that we + + + align:start position:0% +like the the massive data that we +collect about students is also what lets + + align:start position:0% +collect about students is also what lets + + + align:start position:0% +collect about students is also what lets +us do pretty sophisticated complicated + + align:start position:0% +us do pretty sophisticated complicated + + + align:start position:0% +us do pretty sophisticated complicated +research about those students to be able + + align:start position:0% +research about those students to be able + + + align:start position:0% +research about those students to be able +to make claims about how well they're + + align:start position:0% +to make claims about how well they're + + + align:start position:0% +to make claims about how well they're +doing in various parts of their lives. + + align:start position:0% + + + + align:start position:0% + +Um toxic power of data experiment. All + + align:start position:0% +Um toxic power of data experiment. All + + + align:start position:0% +Um toxic power of data experiment. All +right, I'll tell you about at least a + + align:start position:0% +right, I'll tell you about at least a + + + align:start position:0% +right, I'll tell you about at least a +couple of other things. + + align:start position:0% +couple of other things. + + + align:start position:0% +couple of other things. +Um, there was a study that you read + + align:start position:0% +Um, there was a study that you read + + + align:start position:0% +Um, there was a study that you read +about um in the chapter last night. Um, + + align:start position:0% +about um in the chapter last night. Um, + + + align:start position:0% +about um in the chapter last night. Um, +this is a headline that came out. It was + + align:start position:0% +this is a headline that came out. It was + + + align:start position:0% +this is a headline that came out. It was +in 2018. There's a headline that came + + align:start position:0% +in 2018. There's a headline that came + + + align:start position:0% +in 2018. There's a headline that came +out about it. Pearson tested social + + align:start position:0% +out about it. Pearson tested social + + + align:start position:0% +out about it. Pearson tested social +psychological messages in learning + + align:start position:0% +psychological messages in learning + + + align:start position:0% +psychological messages in learning +software with mixed results. I don't did + + align:start position:0% +software with mixed results. I don't did + + + align:start position:0% +software with mixed results. I don't did +we talk about mindset in this class? + + align:start position:0% +we talk about mindset in this class? + + + align:start position:0% +we talk about mindset in this class? +Maybe we did briefly. Growth mindset and + + align:start position:0% +Maybe we did briefly. Growth mindset and + + + align:start position:0% +Maybe we did briefly. Growth mindset and +fixed mindset. something you're probably + + align:start position:0% +fixed mindset. something you're probably + + + align:start position:0% +fixed mindset. something you're probably +all familiar with it because teachers + + align:start position:0% +all familiar with it because teachers + + + align:start position:0% +all familiar with it because teachers +talk about all the time. Um but there + + align:start position:0% +talk about all the time. Um but there + + + align:start position:0% +talk about all the time. Um but there +were or education researchers other + + align:start position:0% +were or education researchers other + + + align:start position:0% +were or education researchers other +folks um there are some social + + align:start position:0% +folks um there are some social + + + align:start position:0% +folks um there are some social +psychologists who have identified um uh + + align:start position:0% +psychologists who have identified um uh + + + align:start position:0% +psychologists who have identified um uh +two kinds of mindsets that people often + + align:start position:0% +two kinds of mindsets that people often + + + align:start position:0% +two kinds of mindsets that people often +have towards learning or other kinds of + + align:start position:0% +have towards learning or other kinds of + + + align:start position:0% +have towards learning or other kinds of +things. One is a fixed mindset which + + align:start position:0% +things. One is a fixed mindset which + + + align:start position:0% +things. One is a fixed mindset which +generally says like some people are + + align:start position:0% +generally says like some people are + + + align:start position:0% +generally says like some people are +smart and some people are not smart. Um + + align:start position:0% +smart and some people are not smart. Um + + + align:start position:0% +smart and some people are not smart. Um +and a growth mindset suggests that um + + align:start position:0% +and a growth mindset suggests that um + + + align:start position:0% +and a growth mindset suggests that um +people have fluid intelligence and you + + align:start position:0% +people have fluid intelligence and you + + + align:start position:0% +people have fluid intelligence and you +can make yourself more intelligent in + + align:start position:0% +can make yourself more intelligent in + + + align:start position:0% +can make yourself more intelligent in +other kinds of things. seems to be a + + align:start position:0% +other kinds of things. seems to be a + + + align:start position:0% +other kinds of things. seems to be a +pretty good idea um to help young people + + align:start position:0% +pretty good idea um to help young people + + + align:start position:0% +pretty good idea um to help young people +adopt the latter mindset rather than the + + align:start position:0% +adopt the latter mindset rather than the + + + align:start position:0% +adopt the latter mindset rather than the +former mindset. Um better to have them + + align:start position:0% +former mindset. Um better to have them + + + align:start position:0% +former mindset. Um better to have them +think uh have a growth mindset rather + + align:start position:0% +think uh have a growth mindset rather + + + align:start position:0% +think uh have a growth mindset rather +than a fixed mindset. Exactly how much + + align:start position:0% +than a fixed mindset. Exactly how much + + + align:start position:0% +than a fixed mindset. Exactly how much +it matters um is a subject of enormous + + align:start position:0% +it matters um is a subject of enormous + + + align:start position:0% +it matters um is a subject of enormous +debate. There were a number of early + + align:start position:0% +debate. There were a number of early + + + align:start position:0% +debate. There were a number of early +studies that suggested it could matter + + align:start position:0% +studies that suggested it could matter + + + align:start position:0% +studies that suggested it could matter +quite enormously to all kinds of people. + + align:start position:0% +quite enormously to all kinds of people. + + + align:start position:0% +quite enormously to all kinds of people. +And some of the more recent larger + + align:start position:0% +And some of the more recent larger + + + align:start position:0% +And some of the more recent larger +studies suggest that like the best + + align:start position:0% +studies suggest that like the best + + + align:start position:0% +studies suggest that like the best +things that we can do that we know how + + align:start position:0% +things that we can do that we know how + + + align:start position:0% +things that we can do that we know how +to do to improve growth mindset only + + align:start position:0% +to do to improve growth mindset only + + + align:start position:0% +to do to improve growth mindset only +help some students and maybe only help + + align:start position:0% +help some students and maybe only help + + + align:start position:0% +help some students and maybe only help +them a little bit like a lot of things + + align:start position:0% +them a little bit like a lot of things + + + align:start position:0% +them a little bit like a lot of things +that we study. Um, so Pearson um offers + + align:start position:0% +that we study. Um, so Pearson um offers + + + align:start position:0% +that we study. Um, so Pearson um offers +all kinds of software products and um uh + + align:start position:0% +all kinds of software products and um uh + + + align:start position:0% +all kinds of software products and um uh +I think this was a a line of computer + + align:start position:0% +I think this was a a line of computer + + + align:start position:0% +I think this was a a line of computer +science software products and so you're + + align:start position:0% +science software products and so you're + + + align:start position:0% +science software products and so you're +like you do a bunch of programming + + align:start position:0% +like you do a bunch of programming + + + align:start position:0% +like you do a bunch of programming +exercises of multiple choice questions + + align:start position:0% +exercises of multiple choice questions + + + align:start position:0% +exercises of multiple choice questions +or things like that and the thing that + + align:start position:0% +or things like that and the thing that + + + align:start position:0% +or things like that and the thing that +they decided to add was not just right + + align:start position:0% +they decided to add was not just right + + + align:start position:0% +they decided to add was not just right +or wrong messages but um randomized you + + align:start position:0% +or wrong messages but um randomized you + + + align:start position:0% +or wrong messages but um randomized you +some people getting growth mindset + + align:start position:0% +some people getting growth mindset + + + align:start position:0% +some people getting growth mindset +messages and some people not getting + + align:start position:0% +messages and some people not getting + + + align:start position:0% +messages and some people not getting +growth mindset messages. So, I won't get + + align:start position:0% +growth mindset messages. So, I won't get + + + align:start position:0% +growth mindset messages. So, I won't get +this exactly right, but example of a + + align:start position:0% +this exactly right, but example of a + + + align:start position:0% +this exactly right, but example of a +growth mindset message, you know, might + + align:start position:0% +growth mindset message, you know, might + + + align:start position:0% +growth mindset message, you know, might +be something like um you know, uh that's + + align:start position:0% +be something like um you know, uh that's + + + align:start position:0% +be something like um you know, uh that's +not right, but keep trying and you can + + align:start position:0% +not right, but keep trying and you can + + + align:start position:0% +not right, but keep trying and you can +learn more or you know, other other + + align:start position:0% +learn more or you know, other other + + + align:start position:0% +learn more or you know, other other +things to suggest that if you keep + + align:start position:0% +things to suggest that if you keep + + + align:start position:0% +things to suggest that if you keep +working at this, you'll get better. + + align:start position:0% +working at this, you'll get better. + + + align:start position:0% +working at this, you'll get better. +Um what seems good about implementing + + align:start position:0% +Um what seems good about implementing + + + align:start position:0% +Um what seems good about implementing +um that kind of intervention in a system + + align:start position:0% +um that kind of intervention in a system + + + align:start position:0% +um that kind of intervention in a system +like this and what seems problematic + + align:start position:0% +like this and what seems problematic + + + align:start position:0% +like this and what seems problematic +about uh implementing an intervention in + + align:start position:0% +about uh implementing an intervention in + + + align:start position:0% +about uh implementing an intervention in +a system like this? + + align:start position:0% + + + + align:start position:0% + +Well, problematic is that the control + + align:start position:0% +Well, problematic is that the control + + + align:start position:0% +Well, problematic is that the control +group is essentially like not + + align:start position:0% +group is essentially like not + + + align:start position:0% +group is essentially like not +necessarily being hurt but not + + align:start position:0% +necessarily being hurt but not + + + align:start position:0% +necessarily being hurt but not +benefiting at all. And like like if + + align:start position:0% +benefiting at all. And like like if + + + align:start position:0% +benefiting at all. And like like if +you're saying that a growth mindset + + align:start position:0% +you're saying that a growth mindset + + + align:start position:0% +you're saying that a growth mindset +really does help people, choosing to + + align:start position:0% +really does help people, choosing to + + + align:start position:0% +really does help people, choosing to +essentially not help them by putting + + align:start position:0% +essentially not help them by putting + + + align:start position:0% +essentially not help them by putting +them in the control group. Yeah, that's + + align:start position:0% +them in the control group. Yeah, that's + + + align:start position:0% +them in the control group. Yeah, that's +interest. So I mean Pearson So Pearson + + align:start position:0% +interest. So I mean Pearson So Pearson + + + align:start position:0% +interest. So I mean Pearson So Pearson +goes and reads a bunch of research about + + align:start position:0% +goes and reads a bunch of research about + + + align:start position:0% +goes and reads a bunch of research about +growth mindset and they're like, "Hey, + + align:start position:0% +growth mindset and they're like, "Hey, + + + align:start position:0% +growth mindset and they're like, "Hey, +this growth mind stuff seems to work + + align:start position:0% +this growth mind stuff seems to work + + + align:start position:0% +this growth mind stuff seems to work +sometimes. Um, but they don't decide to + + align:start position:0% +sometimes. Um, but they don't decide to + + + align:start position:0% +sometimes. Um, but they don't decide to +just add it to their product. They add + + align:start position:0% +just add it to their product. They add + + + align:start position:0% +just add it to their product. They add +it to their product in this kind of + + align:start position:0% +it to their product in this kind of + + + align:start position:0% +it to their product in this kind of +experimental paradigm where some people + + align:start position:0% +experimental paradigm where some people + + + align:start position:0% +experimental paradigm where some people +get it and some people don't. Um, and so + + align:start position:0% +get it and some people don't. Um, and so + + + align:start position:0% +get it and some people don't. Um, and so +people in the same class are going to + + align:start position:0% +people in the same class are going to + + + align:start position:0% +people in the same class are going to +have a different experience. Um so Dana + + align:start position:0% +have a different experience. Um so Dana + + + align:start position:0% +have a different experience. Um so Dana +proposes that one problem with that is + + align:start position:0% +proposes that one problem with that is + + + align:start position:0% +proposes that one problem with that is +that um the people who get the uh + + align:start position:0% +that um the people who get the uh + + + align:start position:0% +that um the people who get the uh +experimental intervention might benefit + + align:start position:0% +experimental intervention might benefit + + + align:start position:0% +experimental intervention might benefit +in the way that people in the control + + align:start position:0% +in the way that people in the control + + + align:start position:0% +in the way that people in the control +group don't. What are some other + + align:start position:0% +group don't. What are some other + + + align:start position:0% +group don't. What are some other +problems that kind of potentially could + + align:start position:0% +problems that kind of potentially could + + + align:start position:0% +problems that kind of potentially could +show up with + + align:start position:0% + + + + align:start position:0% + +this? I guess you have to take into + + align:start position:0% +this? I guess you have to take into + + + align:start position:0% +this? I guess you have to take into +account like who's in the control group + + align:start position:0% +account like who's in the control group + + + align:start position:0% +account like who's in the control group +and who's in the experimental group. How + + align:start position:0% +and who's in the experimental group. How + + + align:start position:0% +and who's in the experimental group. How +good of a job do they do at filtering + + align:start position:0% +good of a job do they do at filtering + + + align:start position:0% +good of a job do they do at filtering +out their students to make sure it's + + align:start position:0% +out their students to make sure it's + + + align:start position:0% +out their students to make sure it's +roughly equal in terms of like + + align:start position:0% +roughly equal in terms of like + + + align:start position:0% +roughly equal in terms of like +socioeconomic background, your prior + + align:start position:0% +socioeconomic background, your prior + + + align:start position:0% +socioeconomic background, your prior +experience with the subject, etc. That's + + align:start position:0% +experience with the subject, etc. That's + + + align:start position:0% +experience with the subject, etc. That's +good. So, I would and I would say under + + align:start position:0% +good. So, I would and I would say under + + + align:start position:0% +good. So, I would and I would say under +most circumstances, especially in these + + align:start position:0% +most circumstances, especially in these + + + align:start position:0% +most circumstances, especially in these +kinds of digital systems, we can be + + align:start position:0% +kinds of digital systems, we can be + + + align:start position:0% +kinds of digital systems, we can be +really good at randomization. um you + + align:start position:0% +really good at randomization. um you + + + align:start position:0% +really good at randomization. um you +know you I mean you could imagine that + + align:start position:0% +know you I mean you could imagine that + + + align:start position:0% +know you I mean you could imagine that +if you're like randomizing across whole + + align:start position:0% +if you're like randomizing across whole + + + align:start position:0% +if you're like randomizing across whole +schools or something like that there + + align:start position:0% +schools or something like that there + + + align:start position:0% +schools or something like that there +might be people who are like well I + + align:start position:0% +might be people who are like well I + + + align:start position:0% +might be people who are like well I +don't want my school to do it or you put + + align:start position:0% +don't want my school to do it or you put + + + align:start position:0% +don't want my school to do it or you put +me in a control group but I just want to + + align:start position:0% +me in a control group but I just want to + + + align:start position:0% +me in a control group but I just want to +get the intervention anyway or something + + align:start position:0% +get the intervention anyway or something + + + align:start position:0% +get the intervention anyway or something +like that. um these kind of digital + + align:start position:0% +like that. um these kind of digital + + + align:start position:0% +like that. um these kind of digital +systems can be like very strict about + + align:start position:0% +systems can be like very strict about + + + align:start position:0% +systems can be like very strict about +the implementation of randomization. Um + + align:start position:0% +the implementation of randomization. Um + + + align:start position:0% +the implementation of randomization. Um +and you could be pretty sure that + + align:start position:0% +and you could be pretty sure that + + + align:start position:0% +and you could be pretty sure that +there's not that there's not going to be + + align:start position:0% +there's not that there's not going to be + + + align:start position:0% +there's not that there's not going to be +any kind of bias and deliver. I mean + + align:start position:0% +any kind of bias and deliver. I mean + + + align:start position:0% +any kind of bias and deliver. I mean +there you can imagine ways for bias to + + align:start position:0% +there you can imagine ways for bias to + + + align:start position:0% +there you can imagine ways for bias to +show up but for the most part it's going + + align:start position:0% +show up but for the most part it's going + + + align:start position:0% +show up but for the most part it's going +to be some you know there's going to be + + align:start position:0% +to be some you know there's going to be + + + align:start position:0% +to be some you know there's going to be +some computer code which is like you + + align:start position:0% +some computer code which is like you + + + align:start position:0% +some computer code which is like you +know if exercise four like assign + + align:start position:0% +know if exercise four like assign + + + align:start position:0% +know if exercise four like assign +someone a zero or one control is zero + + align:start position:0% +someone a zero or one control is zero + + + align:start position:0% +someone a zero or one control is zero +experiment is one and especially if you + + align:start position:0% +experiment is one and especially if you + + + align:start position:0% +experiment is one and especially if you +have hundreds or thousands of people who + + align:start position:0% +have hundreds or thousands of people who + + + align:start position:0% +have hundreds or thousands of people who +are participating in the experiment you + + align:start position:0% +are participating in the experiment you + + + align:start position:0% +are participating in the experiment you +can be pretty sure that those two groups + + align:start position:0% +can be pretty sure that those two groups + + + align:start position:0% +can be pretty sure that those two groups +are are the same. Um not only that but + + align:start position:0% +are are the same. Um not only that but + + + align:start position:0% +are are the same. Um not only that but +you can also verify that they're the + + align:start position:0% +you can also verify that they're the + + + align:start position:0% +you can also verify that they're the +same if you collect all this information + + align:start position:0% +same if you collect all this information + + + align:start position:0% +same if you collect all this information +about them going into it. Um so these + + align:start position:0% +about them going into it. Um so these + + + align:start position:0% +about them going into it. Um so these +things are going to be pretty good at + + align:start position:0% +things are going to be pretty good at + + + align:start position:0% +things are going to be pretty good at +that. Um well I don't know if there was + + align:start position:0% +that. Um well I don't know if there was + + + align:start position:0% +that. Um well I don't know if there was +any consent given but like from what I + + align:start position:0% +any consent given but like from what I + + + align:start position:0% +any consent given but like from what I +can gather is that this was just done + + align:start position:0% +can gather is that this was just done + + + align:start position:0% +can gather is that this was just done +without the students knowledge. Yes. And + + align:start position:0% +without the students knowledge. Yes. And + + + align:start position:0% +without the students knowledge. Yes. And +so it's like I wouldn't necessarily like + + align:start position:0% +so it's like I wouldn't necessarily like + + + align:start position:0% +so it's like I wouldn't necessarily like +it if I like came out of MIT graduating + + align:start position:0% +it if I like came out of MIT graduating + + + align:start position:0% +it if I like came out of MIT graduating +and then someone's like okay here's a + + align:start position:0% +and then someone's like okay here's a + + + align:start position:0% +and then someone's like okay here's a +paper of like what we analyzed during + + align:start position:0% +paper of like what we analyzed during + + + align:start position:0% +paper of like what we analyzed during +their four years here. I'm like I don't + + align:start position:0% +their four years here. I'm like I don't + + + align:start position:0% +their four years here. I'm like I don't +necessarily want to know that people + + align:start position:0% +necessarily want to know that people + + + align:start position:0% +necessarily want to know that people +have been like watching my like every + + align:start position:0% +have been like watching my like every + + + align:start position:0% +have been like watching my like every +move and analyzing like certain things + + align:start position:0% +move and analyzing like certain things + + + align:start position:0% +move and analyzing like certain things +about me psychologically. Uh-huh. Why + + align:start position:0% +about me psychologically. Uh-huh. Why + + + align:start position:0% +about me psychologically. Uh-huh. Why +not? It feels a little creepy. Feels + + align:start position:0% +not? It feels a little creepy. Feels + + + align:start position:0% +not? It feels a little creepy. Feels +like you're being watched, right? Feels + + align:start position:0% +like you're being watched, right? Feels + + + align:start position:0% +like you're being watched, right? Feels +a little creepy. Without any consent, I + + align:start position:0% +a little creepy. Without any consent, I + + + align:start position:0% +a little creepy. Without any consent, I +can see why this is like good. Other + + align:start position:0% +can see why this is like good. Other + + + align:start position:0% +can see why this is like good. Other +other observations that people have? + + align:start position:0% +other observations that people have? + + + align:start position:0% +other observations that people have? +Also, calling it like a social + + align:start position:0% +Also, calling it like a social + + + align:start position:0% +Also, calling it like a social +psychological message kind of makes it + + align:start position:0% +psychological message kind of makes it + + + align:start position:0% +psychological message kind of makes it +feel like the experimental groups being + + align:start position:0% +feel like the experimental groups being + + + align:start position:0% +feel like the experimental groups being +like propagandized or something like + + align:start position:0% +like propagandized or something like + + + align:start position:0% +like propagandized or something like +that. And so it's like, oh, they're + + align:start position:0% +that. And so it's like, oh, they're + + + align:start position:0% +that. And so it's like, oh, they're +being experimented with these like these + + align:start position:0% +being experimented with these like these + + + align:start position:0% +being experimented with these like these +different gen psychological messages. + + align:start position:0% +different gen psychological messages. + + + align:start position:0% +different gen psychological messages. +Yeah. It's like it seems like that + + align:start position:0% +Yeah. It's like it seems like that + + + align:start position:0% +Yeah. It's like it seems like that +specific verbiage can like be kind of + + align:start position:0% +specific verbiage can like be kind of + + + align:start position:0% +specific verbiage can like be kind of +uncomfortable for people to accept as + + align:start position:0% +uncomfortable for people to accept as + + + align:start position:0% +uncomfortable for people to accept as +something that is potentially + + align:start position:0% +something that is potentially + + + align:start position:0% +something that is potentially +beneficial. Good. Yeah. Yeah. So I mean + + align:start position:0% +beneficial. Good. Yeah. Yeah. So I mean + + + align:start position:0% +beneficial. Good. Yeah. Yeah. So I mean +the reason why people are doing the + + align:start position:0% +the reason why people are doing the + + + align:start position:0% +the reason why people are doing the +social psychological messaging is + + align:start position:0% +social psychological messaging is + + + align:start position:0% +social psychological messaging is +because maybe it works actually you know + + align:start position:0% +because maybe it works actually you know + + + align:start position:0% +because maybe it works actually you know +and it's not and in this particular case + + align:start position:0% +and it's not and in this particular case + + + align:start position:0% +and it's not and in this particular case +it's not just like hey we got kind of a + + align:start position:0% +it's not just like hey we got kind of a + + + align:start position:0% +it's not just like hey we got kind of a +hunch this works these like well + + align:start position:0% +hunch this works these like well + + + align:start position:0% +hunch this works these like well +actually there you know at this point + + align:start position:0% +actually there you know at this point + + + align:start position:0% +actually there you know at this point +there was maybe like a decade of + + align:start position:0% +there was maybe like a decade of + + + align:start position:0% +there was maybe like a decade of +research that was was totally plausibly + + align:start position:0% +research that was was totally plausibly + + + align:start position:0% +research that was was totally plausibly +suggesting that this could genuinely + + align:start position:0% +suggesting that this could genuinely + + + align:start position:0% +suggesting that this could genuinely +help students learn and improve their + + align:start position:0% +help students learn and improve their + + + align:start position:0% +help students learn and improve their +their life outcomes and other kinds of + + align:start position:0% +their life outcomes and other kinds of + + + align:start position:0% +their life outcomes and other kinds of +things like that. Um and the and the way + + align:start position:0% +things like that. Um and the and the way + + + align:start position:0% +things like that. Um and the and the way +you do that is through an inter you know + + align:start position:0% +you do that is through an inter you know + + + align:start position:0% +you do that is through an inter you know +through a social psychological + + align:start position:0% +through a social psychological + + + align:start position:0% +through a social psychological +intervention. Although it's you know not + + align:start position:0% +intervention. Although it's you know not + + + align:start position:0% +intervention. Although it's you know not +clear to me what in schools is not + + align:start position:0% +clear to me what in schools is not + + + align:start position:0% +clear to me what in schools is not +social psychological. + + align:start position:0% + + + + align:start position:0% + +I was going to say another thing that as + + align:start position:0% +I was going to say another thing that as + + + align:start position:0% +I was going to say another thing that as +much as like we need the two populations + + align:start position:0% +much as like we need the two populations + + + align:start position:0% +much as like we need the two populations +to be like just as representative are + + align:start position:0% +to be like just as representative are + + + align:start position:0% +to be like just as representative are +the experimental groups even + + align:start position:0% +the experimental groups even + + + align:start position:0% +the experimental groups even +representative of the general population + + align:start position:0% +representative of the general population + + + align:start position:0% +representative of the general population +like you have to imagine that people + + align:start position:0% +like you have to imagine that people + + + align:start position:0% +like you have to imagine that people +aren't being forced to participate in + + align:start position:0% +aren't being forced to participate in + + + align:start position:0% +aren't being forced to participate in +these things or maybe if they are like + + align:start position:0% +these things or maybe if they are like + + + align:start position:0% +these things or maybe if they are like +the schools that they chose are they + + align:start position:0% +the schools that they chose are they + + + align:start position:0% +the schools that they chose are they +actually representative of the entire + + align:start position:0% +actually representative of the entire + + + align:start position:0% +actually representative of the entire +population. So because like there + + align:start position:0% +population. So because like there + + + align:start position:0% +population. So because like there +obviously are studies where they get + + align:start position:0% +obviously are studies where they get + + + align:start position:0% +obviously are studies where they get +like outstanding results but then the + + align:start position:0% +like outstanding results but then the + + + align:start position:0% +like outstanding results but then the +population used is not representative of + + align:start position:0% +population used is not representative of + + + align:start position:0% +population used is not representative of +the general population. So then once + + align:start position:0% +the general population. So then once + + + align:start position:0% +the general population. So then once +they apply those doesn't actually work. + + align:start position:0% +they apply those doesn't actually work. + + + align:start position:0% +they apply those doesn't actually work. +Yeah. Yeah. Good. Um you know and to + + align:start position:0% +Yeah. Yeah. Good. Um you know and to + + + align:start position:0% +Yeah. Yeah. Good. Um you know and to +some extent you might think that + + align:start position:0% +some extent you might think that + + + align:start position:0% +some extent you might think that +organizations like Pearson would have an + + align:start position:0% +organizations like Pearson would have an + + + align:start position:0% +organizations like Pearson would have an +advantage over much smaller companies um + + align:start position:0% +advantage over much smaller companies um + + + align:start position:0% +advantage over much smaller companies um +because if you have products that are + + align:start position:0% +because if you have products that are + + + align:start position:0% +because if you have products that are +adopted very very widely across the + + align:start position:0% +adopted very very widely across the + + + align:start position:0% +adopted very very widely across the +country in lots of different contexts. I + + align:start position:0% +country in lots of different contexts. I + + + align:start position:0% +country in lots of different contexts. I +mean, you might for practical purposes + + align:start position:0% +mean, you might for practical purposes + + + align:start position:0% +mean, you might for practical purposes +say like, let's just pick these handful + + align:start position:0% +say like, let's just pick these handful + + + align:start position:0% +say like, let's just pick these handful +of schools um to be able to test things + + align:start position:0% +of schools um to be able to test things + + + align:start position:0% +of schools um to be able to test things +in, but you could say like we're going + + align:start position:0% +in, but you could say like we're going + + + align:start position:0% +in, but you could say like we're going +to pick these handful of of schools + + align:start position:0% +to pick these handful of of schools + + + align:start position:0% +to pick these handful of of schools +because like these are particularly + + align:start position:0% +because like these are particularly + + + align:start position:0% +because like these are particularly +representative schools. Um or, you know, + + align:start position:0% +representative schools. Um or, you know, + + + align:start position:0% +representative schools. Um or, you know, +there might be systems that are that are + + align:start position:0% +there might be systems that are that are + + + align:start position:0% +there might be systems that are that are +adopted and laid out in such a way that + + align:start position:0% +adopted and laid out in such a way that + + + align:start position:0% +adopted and laid out in such a way that +you say like, well, let's, you know, + + align:start position:0% +you say like, well, let's, you know, + + + align:start position:0% +you say like, well, let's, you know, +let's just pick 1% of all students in + + align:start position:0% +let's just pick 1% of all students in + + + align:start position:0% +let's just pick 1% of all students in +any of the schools who are using our + + align:start position:0% +any of the schools who are using our + + + align:start position:0% +any of the schools who are using our +system to get, you know, um participate + + align:start position:0% +system to get, you know, um participate + + + align:start position:0% +system to get, you know, um participate +in this randomized study or something + + align:start position:0% +in this randomized study or something + + + align:start position:0% +in this randomized study or something +like that. I feel like we talked a lot + + align:start position:0% +like that. I feel like we talked a lot + + + align:start position:0% +like that. I feel like we talked a lot +about like all of the things that go + + align:start position:0% +about like all of the things that go + + + align:start position:0% +about like all of the things that go +into using like a software program + + align:start position:0% +into using like a software program + + + align:start position:0% +into using like a software program +because obviously that then entails that + + align:start position:0% +because obviously that then entails that + + + align:start position:0% +because obviously that then entails that +you have something to run the software + + align:start position:0% +you have something to run the software + + + align:start position:0% +you have something to run the software +program on. So anything online already + + align:start position:0% +program on. So anything online already + + + align:start position:0% +program on. So anything online already +comes with its own set of like biases + + align:start position:0% +comes with its own set of like biases + + + align:start position:0% +comes with its own set of like biases +and um like things that affect the types + + align:start position:0% +and um like things that affect the types + + + align:start position:0% +and um like things that affect the types +of people that are using it. Yeah. Yeah. + + align:start position:0% +of people that are using it. Yeah. Yeah. + + + align:start position:0% +of people that are using it. Yeah. Yeah. +Yeah. No, I think that's fair. Also, + + align:start position:0% +Yeah. No, I think that's fair. Also, + + + align:start position:0% +Yeah. No, I think that's fair. Also, +another thing that I just realized in + + align:start position:0% +another thing that I just realized in + + + align:start position:0% +another thing that I just realized in +what uh Dana said was the population + + align:start position:0% +what uh Dana said was the population + + + align:start position:0% +what uh Dana said was the population +that that they're testing this on is in + + align:start position:0% +that that they're testing this on is in + + + align:start position:0% +that that they're testing this on is in +college. So, they've already probably + + align:start position:0% +college. So, they've already probably + + + align:start position:0% +college. So, they've already probably +developed a mindset. Um and also they + + align:start position:0% +developed a mindset. Um and also they + + + align:start position:0% +developed a mindset. Um and also they +are in college. Like they probably have + + align:start position:0% +are in college. Like they probably have + + + align:start position:0% +are in college. Like they probably have +already a good enough mindset that got + + align:start position:0% +already a good enough mindset that got + + + align:start position:0% +already a good enough mindset that got +them to college. Yep. Yep. although that + + align:start position:0% +them to college. Yep. Yep. although that + + + align:start position:0% +them to college. Yep. Yep. although that +you know I mean and um well one thing + + align:start position:0% +you know I mean and um well one thing + + + align:start position:0% +you know I mean and um well one thing +that I really love about the study which + + align:start position:0% +that I really love about the study which + + + align:start position:0% +that I really love about the study which +I think um so so I I wrote some after + + align:start position:0% +I think um so so I I wrote some after + + + align:start position:0% +I think um so so I I wrote some after +this article came out um I wrote a bunch + + align:start position:0% +this article came out um I wrote a bunch + + + align:start position:0% +this article came out um I wrote a bunch +of things which which basically said I + + align:start position:0% +of things which which basically said I + + + align:start position:0% +of things which which basically said I +think this is a pretty unfair article. + + align:start position:0% +think this is a pretty unfair article. + + + align:start position:0% +think this is a pretty unfair article. +Um here I'll give you the case for why I + + align:start position:0% +Um here I'll give you the case for why I + + + align:start position:0% +Um here I'll give you the case for why I +I I think what Pearson did here is + + align:start position:0% +I I think what Pearson did here is + + + align:start position:0% +I I think what Pearson did here is +admirable and needs to be done more + + align:start position:0% +admirable and needs to be done more + + + align:start position:0% +admirable and needs to be done more +although you don't have to agree with + + align:start position:0% +although you don't have to agree with + + + align:start position:0% +although you don't have to agree with +me. Um so number one + + align:start position:0% +me. Um so number one + + + align:start position:0% +me. Um so number one +um generally speaking there's a body of + + align:start position:0% +um generally speaking there's a body of + + + align:start position:0% +um generally speaking there's a body of +research that suggests these things are + + align:start position:0% +research that suggests these things are + + + align:start position:0% +research that suggests these things are +a good idea. We don't know however are + + align:start position:0% +a good idea. We don't know however are + + + align:start position:0% +a good idea. We don't know however are +they a good idea in this particular + + align:start position:0% +they a good idea in this particular + + + align:start position:0% +they a good idea in this particular +product for this particular population. + + align:start position:0% +product for this particular population. + + + align:start position:0% +product for this particular population. +So I think it makes more sense um to run + + align:start position:0% +So I think it makes more sense um to run + + + align:start position:0% +So I think it makes more sense um to run +an experiment in this particular product + + align:start position:0% +an experiment in this particular product + + + align:start position:0% +an experiment in this particular product +for this particular population to test + + align:start position:0% +for this particular population to test + + + align:start position:0% +for this particular population to test +the thing rather than just roll it out. + + align:start position:0% +the thing rather than just roll it out. + + + align:start position:0% +the thing rather than just roll it out. +I mean this is an important sort of + + align:start position:0% +I mean this is an important sort of + + + align:start position:0% +I mean this is an important sort of +counterfactual. If Pearson had simply + + align:start position:0% +counterfactual. If Pearson had simply + + + align:start position:0% +counterfactual. If Pearson had simply +added these messages to everyone in the + + align:start position:0% +added these messages to everyone in the + + + align:start position:0% +added these messages to everyone in the +product, there never would have been an + + align:start position:0% +product, there never would have been an + + + align:start position:0% +product, there never would have been an +article about it. Um, nobody would have + + align:start position:0% +article about it. Um, nobody would have + + + align:start position:0% +article about it. Um, nobody would have +ever written, you know, like like like + + align:start position:0% +ever written, you know, like like like + + + align:start position:0% +ever written, you know, like like like +you know, encouraging messages show up + + align:start position:0% +you know, encouraging messages show up + + + align:start position:0% +you know, encouraging messages show up +in software product is like not an + + align:start position:0% +in software product is like not an + + + align:start position:0% +in software product is like not an +article that even the education press um + + align:start position:0% +article that even the education press um + + + align:start position:0% +article that even the education press um +is going to populate. Um, number two, + + align:start position:0% +is going to populate. Um, number two, + + + align:start position:0% +is going to populate. Um, number two, +you know, like another counterfactual, + + align:start position:0% +you know, like another counterfactual, + + + align:start position:0% +you know, like another counterfactual, +there is no nonsocial psychological + + align:start position:0% +there is no nonsocial psychological + + + align:start position:0% +there is no nonsocial psychological +response um to like every mark your + + align:start position:0% +response um to like every mark your + + + align:start position:0% +response um to like every mark your +teacher has ever put on your paper to + + align:start position:0% +teacher has ever put on your paper to + + + align:start position:0% +teacher has ever put on your paper to +indicate whether you're right or wrong + + align:start position:0% +indicate whether you're right or wrong + + + align:start position:0% +indicate whether you're right or wrong +is a social psychological message. Um, + + align:start position:0% +is a social psychological message. Um, + + + align:start position:0% +is a social psychological message. Um, +if you go on edex and get something + + align:start position:0% +if you go on edex and get something + + + align:start position:0% +if you go on edex and get something +right, you're going to get a green + + align:start position:0% +right, you're going to get a green + + + align:start position:0% +right, you're going to get a green +check. If you're going to get something + + align:start position:0% +check. If you're going to get something + + + align:start position:0% +check. If you're going to get something +wrong, you're going to get a red X. Like + + align:start position:0% +wrong, you're going to get a red X. Like + + + align:start position:0% +wrong, you're going to get a red X. Like +that is a set of messaging. If you've + + align:start position:0% +that is a set of messaging. If you've + + + align:start position:0% +that is a set of messaging. If you've +ever had a, you know, none of us would + + align:start position:0% +ever had a, you know, none of us would + + + align:start position:0% +ever had a, you know, none of us would +say that teachers who say try harder or + + align:start position:0% +say that teachers who say try harder or + + + align:start position:0% +say that teachers who say try harder or +that was great. I'm really proud of you. + + align:start position:0% +that was great. I'm really proud of you. + + + align:start position:0% +that was great. I'm really proud of you. +Like no one would be like, you know, + + align:start position:0% +Like no one would be like, you know, + + + align:start position:0% +Like no one would be like, you know, +Miss Jenkins, stop manipulating my + + align:start position:0% +Miss Jenkins, stop manipulating my + + + align:start position:0% +Miss Jenkins, stop manipulating my +children. Like no, that's like exactly + + align:start position:0% +children. Like no, that's like exactly + + + align:start position:0% +children. Like no, that's like exactly +what we want them to do. Um + + align:start position:0% +what we want them to do. Um + + + align:start position:0% +what we want them to do. Um +uh some people are concerned um about + + align:start position:0% +uh some people are concerned um about + + + align:start position:0% +uh some people are concerned um about +consent. Um people who go to school do + + align:start position:0% +consent. Um people who go to school do + + + align:start position:0% +consent. Um people who go to school do +not consent to their learning + + align:start position:0% +not consent to their learning + + + align:start position:0% +not consent to their learning +experiences. Um, one of the things that + + align:start position:0% +experiences. Um, one of the things that + + + align:start position:0% +experiences. Um, one of the things that +we do as a state is say like you must + + align:start position:0% +we do as a state is say like you must + + + align:start position:0% +we do as a state is say like you must +learn stuff and in fact you must learn + + align:start position:0% +learn stuff and in fact you must learn + + + align:start position:0% +learn stuff and in fact you must learn +stuff that the state just requires you + + align:start position:0% +stuff that the state just requires you + + + align:start position:0% +stuff that the state just requires you +to learn. Um, you don't get you know um + + align:start position:0% +to learn. Um, you don't get you know um + + + align:start position:0% +to learn. Um, you don't get you know um +these people didn't get to decide which + + align:start position:0% +these people didn't get to decide which + + + align:start position:0% +these people didn't get to decide which +Pearson product or which computer + + align:start position:0% +Pearson product or which computer + + + align:start position:0% +Pearson product or which computer +science project they they chose. Um why + + align:start position:0% +science project they they chose. Um why + + + align:start position:0% +science project they they chose. Um why +should they get to decide whether or not + + align:start position:0% +should they get to decide whether or not + + + align:start position:0% +should they get to decide whether or not +they get an experimental version or a + + align:start position:0% +they get an experimental version or a + + + align:start position:0% +they get an experimental version or a +control version? And in fact um uh the + + align:start position:0% +control version? And in fact um uh the + + + align:start position:0% +control version? And in fact um uh the +US government for the most part agrees + + align:start position:0% +US government for the most part agrees + + + align:start position:0% +US government for the most part agrees +with this principle. So um there's a + + align:start position:0% +with this principle. So um there's a + + + align:start position:0% +with this principle. So um there's a +rule called the common rule um which + + align:start position:0% +rule called the common rule um which + + + align:start position:0% +rule called the common rule um which +dictates how research can be conducted. + + align:start position:0% +dictates how research can be conducted. + + + align:start position:0% +dictates how research can be conducted. +Um uh there's a bunch of policy guidance + + align:start position:0% +Um uh there's a bunch of policy guidance + + + align:start position:0% +Um uh there's a bunch of policy guidance +that's associated with that and there's + + align:start position:0% +that's associated with that and there's + + + align:start position:0% +that's associated with that and there's +some categories of research that are + + align:start position:0% +some categories of research that are + + + align:start position:0% +some categories of research that are +exempt. The first category of research + + align:start position:0% +exempt. The first category of research + + + align:start position:0% +exempt. The first category of research +that's exempt is research about typical + + align:start position:0% +that's exempt is research about typical + + + align:start position:0% +that's exempt is research about typical +educational practices. Um if you're + + align:start position:0% +educational practices. Um if you're + + + align:start position:0% +educational practices. Um if you're +studying the kinds of ways people teach + + align:start position:0% +studying the kinds of ways people teach + + + align:start position:0% +studying the kinds of ways people teach +and learn in the classroom, you are not + + align:start position:0% +and learn in the classroom, you are not + + + align:start position:0% +and learn in the classroom, you are not +held to the same standard if you're + + align:start position:0% +held to the same standard if you're + + + align:start position:0% +held to the same standard if you're +doing pharmaceutical research or + + align:start position:0% +doing pharmaceutical research or + + + align:start position:0% +doing pharmaceutical research or +something like that. Um there are some + + align:start position:0% +something like that. Um there are some + + + align:start position:0% +something like that. Um there are some +there are some exception like if you're + + align:start position:0% +there are some exception like if you're + + + align:start position:0% +there are some exception like if you're +doing things that you that like you + + align:start position:0% +doing things that you that like you + + + align:start position:0% +doing things that you that like you +could reasonably believe in advance um + + align:start position:0% +could reasonably believe in advance um + + + align:start position:0% +could reasonably believe in advance um +might harm people um then you're not + + align:start position:0% +might harm people um then you're not + + + align:start position:0% +might harm people um then you're not +exempted in the same way although you + + align:start position:0% +exempted in the same way although you + + + align:start position:0% +exempted in the same way although you +can still conceivably uh do the + + align:start position:0% +can still conceivably uh do the + + + align:start position:0% +can still conceivably uh do the +research. Um you know another thing + + align:start position:0% +research. Um you know another thing + + + align:start position:0% +research. Um you know another thing +that's important about the study is that + + align:start position:0% +that's important about the study is that + + + align:start position:0% +that's important about the study is that +um like people people talk about the + + align:start position:0% +um like people people talk about the + + + align:start position:0% +um like people people talk about the +potential benefits of an experiment um + + align:start position:0% +potential benefits of an experiment um + + + align:start position:0% +potential benefits of an experiment um +but experiments can also harm people. + + align:start position:0% +but experiments can also harm people. + + + align:start position:0% +but experiments can also harm people. +Like it it could be that even if on + + align:start position:0% +Like it it could be that even if on + + + align:start position:0% +Like it it could be that even if on +average this growth messaging was great + + align:start position:0% +average this growth messaging was great + + + align:start position:0% +average this growth messaging was great +and worked in lots of studies, it could + + align:start position:0% +and worked in lots of studies, it could + + + align:start position:0% +and worked in lots of studies, it could +be that like in this particular context + + align:start position:0% +be that like in this particular context + + + align:start position:0% +be that like in this particular context +or other kinds of things um uh it made + + align:start position:0% +or other kinds of things um uh it made + + + align:start position:0% +or other kinds of things um uh it made +things worse and we should probably make + + align:start position:0% +things worse and we should probably make + + + align:start position:0% +things worse and we should probably make +sure that when we introduce things in + + align:start position:0% +sure that when we introduce things in + + + align:start position:0% +sure that when we introduce things in +the classroom make things worse. Um, how + + align:start position:0% +the classroom make things worse. Um, how + + + align:start position:0% +the classroom make things worse. Um, how +many people would have been concerned? + + align:start position:0% +many people would have been concerned? + + + align:start position:0% +many people would have been concerned? +Let's say that in + + align:start position:0% +Let's say that in + + + align:start position:0% +Let's say that in +2017 they had everyone use one Pearson + + align:start position:0% +2017 they had everyone use one Pearson + + + align:start position:0% +2017 they had everyone use one Pearson +product maybe that doesn't have any + + align:start position:0% +product maybe that doesn't have any + + + align:start position:0% +product maybe that doesn't have any +growth messaging and in 2018 everyone + + align:start position:0% +growth messaging and in 2018 everyone + + + align:start position:0% +growth messaging and in 2018 everyone +use a Pearson product that had the + + align:start position:0% +use a Pearson product that had the + + + align:start position:0% +use a Pearson product that had the +messaging associated with it. Um, do you + + align:start position:0% +messaging associated with it. Um, do you + + + align:start position:0% +messaging associated with it. Um, do you +think that would have raised people's + + align:start position:0% +think that would have raised people's + + + align:start position:0% +think that would have raised people's +concern or felt + + align:start position:0% +concern or felt + + + align:start position:0% +concern or felt +creepy? Like why not? Why does that feel + + align:start position:0% +creepy? Like why not? Why does that feel + + + align:start position:0% +creepy? Like why not? Why does that feel +okay? + + align:start position:0% + + + + align:start position:0% + +You're like, "Wait a minute, it's the + + align:start position:0% +You're like, "Wait a minute, it's the + + + align:start position:0% +You're like, "Wait a minute, it's the +exact same thing." I think there's this + + align:start position:0% +exact same thing." I think there's this + + + align:start position:0% +exact same thing." I think there's this +idea of + + align:start position:0% +idea of + + + align:start position:0% +idea of +like potential discrimination, like, + + align:start position:0% +like potential discrimination, like, + + + align:start position:0% +like potential discrimination, like, +"Hey, why can't I be part of that?" + + align:start position:0% +"Hey, why can't I be part of that?" + + + align:start position:0% +"Hey, why can't I be part of that?" +Like, it's either everybody or nobody. + + align:start position:0% +Like, it's either everybody or nobody. + + + align:start position:0% +Like, it's either everybody or nobody. +But part the more an intervention is + + align:start position:0% +But part the more an intervention is + + + align:start position:0% +But part the more an intervention is +particularly powerful, the more you're + + align:start position:0% +particularly powerful, the more you're + + + align:start position:0% +particularly powerful, the more you're +like, ah, it feels kind of like if you + + align:start position:0% +like, ah, it feels kind of like if you + + + align:start position:0% +like, ah, it feels kind of like if you +know control group like gets this + + align:start position:0% +know control group like gets this + + + align:start position:0% +know control group like gets this +intervention and gets an average grade + + align:start position:0% +intervention and gets an average grade + + + align:start position:0% +intervention and gets an average grade +of 89. Um, an experimental group, you + + align:start position:0% +of 89. Um, an experimental group, you + + + align:start position:0% +of 89. Um, an experimental group, you +know, gets the intervention and they + + align:start position:0% +know, gets the intervention and they + + + align:start position:0% +know, gets the intervention and they +have an average grade of 89.5. Like + + align:start position:0% +have an average grade of 89.5. Like + + + align:start position:0% +have an average grade of 89.5. Like +that's there's something that seems + + align:start position:0% +that's there's something that seems + + + align:start position:0% +that's there's something that seems +unfair about that. Although again like + + align:start position:0% +unfair about that. Although again like + + + align:start position:0% +unfair about that. Although again like +you know if in 2018 we give you a + + align:start position:0% +you know if in 2018 we give you a + + + align:start position:0% +you know if in 2018 we give you a +software product that you get an average + + align:start position:0% +software product that you get an average + + + align:start position:0% +software product that you get an average +grade of an 89 and then the following + + align:start position:0% +grade of an 89 and then the following + + + align:start position:0% +grade of an 89 and then the following +year we give you a software product with + + align:start position:0% +year we give you a software product with + + + align:start position:0% +year we give you a software product with +an average grade of + + align:start position:0% +an average grade of + + + align:start position:0% +an average grade of +89.5. Um like your birth year was pretty + + align:start position:0% +89.5. Um like your birth year was pretty + + + align:start position:0% +89.5. Um like your birth year was pretty +random + + align:start position:0% +random + + + align:start position:0% +random +too. And so there's something about + + align:start position:0% +too. And so there's something about + + + align:start position:0% +too. And so there's something about +that. I mean you know the case I want to + + align:start position:0% +that. I mean you know the case I want to + + + align:start position:0% +that. I mean you know the case I want to +make is that here here's another way to + + align:start position:0% +make is that here here's another way to + + + align:start position:0% +make is that here here's another way to +think about it. + + align:start position:0% +think about it. + + + align:start position:0% +think about it. +Um most people would be appalled by an + + align:start position:0% +Um most people would be appalled by an + + + align:start position:0% +Um most people would be appalled by an +education system that didn't have + + align:start position:0% +education system that didn't have + + + align:start position:0% +education system that didn't have +variation. Like my hunch is all of you + + align:start position:0% +variation. Like my hunch is all of you + + + align:start position:0% +variation. Like my hunch is all of you +believe that variation is an essential + + align:start position:0% +believe that variation is an essential + + + align:start position:0% +believe that variation is an essential +part of educational systems. Like you + + align:start position:0% +part of educational systems. Like you + + + align:start position:0% +part of educational systems. Like you +believe that your teachers, your public + + align:start position:0% +believe that your teachers, your public + + + align:start position:0% +believe that your teachers, your public +your p your textbook publishers, your + + align:start position:0% +your p your textbook publishers, your + + + align:start position:0% +your p your textbook publishers, your +software developers should be trying to + + align:start position:0% +software developers should be trying to + + + align:start position:0% +software developers should be trying to +improve their products. Um they should + + align:start position:0% +improve their products. Um they should + + + align:start position:0% +improve their products. Um they should +be trying to improve their instruction. + + align:start position:0% +be trying to improve their instruction. + + + align:start position:0% +be trying to improve their instruction. +They should be trying to improve their + + align:start position:0% +They should be trying to improve their + + + align:start position:0% +They should be trying to improve their +lesson plans. The only way you do that + + align:start position:0% +lesson plans. The only way you do that + + + align:start position:0% +lesson plans. The only way you do that +is through variation. You teach one + + align:start position:0% +is through variation. You teach one + + + align:start position:0% +is through variation. You teach one +lesson plan one year, you teach a + + align:start position:0% +lesson plan one year, you teach a + + + align:start position:0% +lesson plan one year, you teach a +different lesson plan the next year. + + align:start position:0% +different lesson plan the next year. + + + align:start position:0% +different lesson plan the next year. +Sometimes it's better, sometimes it + + align:start position:0% +Sometimes it's better, sometimes it + + + align:start position:0% +Sometimes it's better, sometimes it +works. My hunch is you all are totally + + align:start position:0% +works. My hunch is you all are totally + + + align:start position:0% +works. My hunch is you all are totally +comfortable with the idea that some of + + align:start position:0% +comfortable with the idea that some of + + + align:start position:0% +comfortable with the idea that some of +that variation will be bad um and that + + align:start position:0% +that variation will be bad um and that + + + align:start position:0% +that variation will be bad um and that +most of it on average will be good. Um + + align:start position:0% +most of it on average will be good. Um + + + align:start position:0% +most of it on average will be good. Um +the main thing that randomized trials + + align:start position:0% +the main thing that randomized trials + + + align:start position:0% +the main thing that randomized trials +like this do is they take that variation + + align:start position:0% +like this do is they take that variation + + + align:start position:0% +like this do is they take that variation +and they make it systematic so we can + + align:start position:0% +and they make it systematic so we can + + + align:start position:0% +and they make it systematic so we can +learn from it. Um if we do one thing in + + align:start position:0% +learn from it. Um if we do one thing in + + + align:start position:0% +learn from it. Um if we do one thing in +2017 and a different thing in 2018, it's + + align:start position:0% +2017 and a different thing in 2018, it's + + + align:start position:0% +2017 and a different thing in 2018, it's +actually it's actually much much harder + + align:start position:0% +actually it's actually much much harder + + + align:start position:0% +actually it's actually much much harder +to figure out if the different thing + + align:start position:0% +to figure out if the different thing + + + align:start position:0% +to figure out if the different thing +worked or not. um because all the people + + align:start position:0% +worked or not. um because all the people + + + align:start position:0% +worked or not. um because all the people +in 2017 might be in some systematic way + + align:start position:0% +in 2017 might be in some systematic way + + + align:start position:0% +in 2017 might be in some systematic way +different from the people in 2018 when + + align:start position:0% +different from the people in 2018 when + + + align:start position:0% +different from the people in 2018 when +we the the best way to be sure that the + + align:start position:0% +we the the best way to be sure that the + + + align:start position:0% +we the the best way to be sure that the +difference between two groups is just + + align:start position:0% +difference between two groups is just + + + align:start position:0% +difference between two groups is just +because of the thing we're intervening + + align:start position:0% +because of the thing we're intervening + + + align:start position:0% +because of the thing we're intervening +about is a randomized trial. That is the + + align:start position:0% +about is a randomized trial. That is the + + + align:start position:0% +about is a randomized trial. That is the +magic of randomized trial. Um so they + + align:start position:0% +magic of randomized trial. Um so they + + + align:start position:0% +magic of randomized trial. Um so they +are power like like everyone in the + + align:start position:0% +are power like like everyone in the + + + align:start position:0% +are power like like everyone in the +education system believes in variation. + + align:start position:0% +education system believes in variation. + + + align:start position:0% +education system believes in variation. +We all want things to improve. + + align:start position:0% +We all want things to improve. + + + align:start position:0% +We all want things to improve. +Um, it's actually not that hard to + + align:start position:0% +Um, it's actually not that hard to + + + align:start position:0% +Um, it's actually not that hard to +convince people that the best way to + + align:start position:0% +convince people that the best way to + + + align:start position:0% +convince people that the best way to +systematically vary things is through + + align:start position:0% +systematically vary things is through + + + align:start position:0% +systematically vary things is through +randomization. Um, and almost all of us + + align:start position:0% +randomization. Um, and almost all of us + + + align:start position:0% +randomization. Um, and almost all of us +find that randomization creepy. Um, like + + align:start position:0% +find that randomization creepy. Um, like + + + align:start position:0% +find that randomization creepy. Um, like +even if you sort of explain all, you're + + align:start position:0% +even if you sort of explain all, you're + + + align:start position:0% +even if you sort of explain all, you're +like, ah, it still doesn't feel right. + + align:start position:0% +like, ah, it still doesn't feel right. + + + align:start position:0% +like, ah, it still doesn't feel right. +Still doesn't feel there's there's been + + align:start position:0% +Still doesn't feel there's there's been + + + align:start position:0% +Still doesn't feel there's there's been +some cool studies I've done in the past. + + align:start position:0% +some cool studies I've done in the past. + + + align:start position:0% +some cool studies I've done in the past. +It shows up in healthcare, shows up in + + align:start position:0% +It shows up in healthcare, shows up in + + + align:start position:0% +It shows up in healthcare, shows up in +other kinds of, you know, things like um + + align:start position:0% +other kinds of, you know, things like um + + + align:start position:0% +other kinds of, you know, things like um +uh you know, you ask patients like, "Do + + align:start position:0% +uh you know, you ask patients like, "Do + + + align:start position:0% +uh you know, you ask patients like, "Do +you want an unproven treatment that + + align:start position:0% +you want an unproven treatment that + + + align:start position:0% +you want an unproven treatment that +might work better?" And they'll be like, + + align:start position:0% +might work better?" And they'll be like, + + + align:start position:0% +might work better?" And they'll be like, +"Well, yeah, maybe." Um, do you want to + + align:start position:0% +"Well, yeah, maybe." Um, do you want to + + + align:start position:0% +"Well, yeah, maybe." Um, do you want to +be randomized to an unproven treatment + + align:start position:0% +be randomized to an unproven treatment + + + align:start position:0% +be randomized to an unproven treatment +that might work better? No. Definitely. + + align:start position:0% +that might work better? No. Definitely. + + + align:start position:0% +that might work better? No. Definitely. +It's like it's the same thing. Um, + + align:start position:0% +It's like it's the same thing. Um, + + + align:start position:0% +It's like it's the same thing. Um, +except we can learn from the + + align:start position:0% +except we can learn from the + + + align:start position:0% +except we can learn from the +randomization. Um my question is in this + + align:start position:0% +randomization. Um my question is in this + + + align:start position:0% +randomization. Um my question is in this +case like how are + + align:start position:0% +case like how are + + + align:start position:0% +case like how are +these different from like when companies + + align:start position:0% +these different from like when companies + + + align:start position:0% +these different from like when companies +release + + align:start position:0% +release + + + align:start position:0% +release +betas that some people get and some + + align:start position:0% +betas that some people get and some + + + align:start position:0% +betas that some people get and some +people don't? Oh here's I mean every + + align:start position:0% +people don't? Oh here's I mean every + + + align:start position:0% +people don't? Oh here's I mean every +time you interact with a software + + align:start position:0% +time you interact with a software + + + align:start position:0% +time you interact with a software +product every time you interact with a + + align:start position:0% +product every time you interact with a + + + align:start position:0% +product every time you interact with a +web-based software product there is a + + align:start position:0% +web-based software product there is a + + + align:start position:0% +web-based software product there is a +reasonable chance you're participating + + align:start position:0% +reasonable chance you're participating + + + align:start position:0% +reasonable chance you're participating +in an experiment just like this. Um one + + align:start position:0% +in an experiment just like this. Um one + + + align:start position:0% +in an experiment just like this. Um one +this the numbers won't be right. One out + + align:start position:0% +this the numbers won't be right. One out + + + align:start position:0% +this the numbers won't be right. One out +of every hundred times you go to Amazon, + + align:start position:0% +of every hundred times you go to Amazon, + + + align:start position:0% +of every hundred times you go to Amazon, +um the buy button is going to be green + + align:start position:0% +um the buy button is going to be green + + + align:start position:0% +um the buy button is going to be green +instead of blue. And someone is doing a + + align:start position:0% +instead of blue. And someone is doing a + + + align:start position:0% +instead of blue. And someone is doing a +test to figure out whether or not you + + align:start position:0% +test to figure out whether or not you + + + align:start position:0% +test to figure out whether or not you +pushing the green button is better. um + + align:start position:0% +pushing the green button is better. um + + + align:start position:0% +pushing the green button is better. um +you know, one out of every hundred time + + align:start position:0% +you know, one out of every hundred time + + + align:start position:0% +you know, one out of every hundred time +or thousand times or 10 times you go to + + align:start position:0% +or thousand times or 10 times you go to + + + align:start position:0% +or thousand times or 10 times you go to +Google, they're going to give you some + + align:start position:0% +Google, they're going to give you some + + + align:start position:0% +Google, they're going to give you some +variation of the search algorithm to see + + align:start position:0% +variation of the search algorithm to see + + + align:start position:0% +variation of the search algorithm to see +if you're happier or you linger longer + + align:start position:0% +if you're happier or you linger longer + + + align:start position:0% +if you're happier or you linger longer +or you're more likely to click ads on, + + align:start position:0% +or you're more likely to click ads on, + + + align:start position:0% +or you're more likely to click ads on, +you know, um we interact every day with + + align:start position:0% +you know, um we interact every day with + + + align:start position:0% +you know, um we interact every day with +software platforms that are collecting + + align:start position:0% +software platforms that are collecting + + + align:start position:0% +software platforms that are collecting +vast amounts of information on us and + + align:start position:0% +vast amounts of information on us and + + + align:start position:0% +vast amounts of information on us and +conducting experiments on us all the + + align:start position:0% +conducting experiments on us all the + + + align:start position:0% +conducting experiments on us all the +time. + + align:start position:0% +time. + + + align:start position:0% +time. +Um th though the reason why those + + align:start position:0% +Um th though the reason why those + + + align:start position:0% +Um th though the reason why those +companies use those two approaches is + + align:start position:0% +companies use those two approaches is + + + align:start position:0% +companies use those two approaches is +because they are enormously powerful at + + align:start position:0% +because they are enormously powerful at + + + align:start position:0% +because they are enormously powerful at +improving products. Um the reason why + + align:start position:0% +improving products. Um the reason why + + + align:start position:0% +improving products. Um the reason why +just about any query you have you go + + align:start position:0% +just about any query you have you go + + + align:start position:0% +just about any query you have you go +into Google and ask it a question and it + + align:start position:0% +into Google and ask it a question and it + + + align:start position:0% +into Google and ask it a question and it +tells you an accurate answer that's + + align:start position:0% +tells you an accurate answer that's + + + align:start position:0% +tells you an accurate answer that's +relevant to the question you asked is + + align:start position:0% +relevant to the question you asked is + + + align:start position:0% +relevant to the question you asked is +because they have conducted billions of + + align:start position:0% +because they have conducted billions of + + + align:start position:0% +because they have conducted billions of +experiments on millions or billions of + + align:start position:0% +experiments on millions or billions of + + + align:start position:0% +experiments on millions or billions of +people uh all throughout the last you + + align:start position:0% +people uh all throughout the last you + + + align:start position:0% +people uh all throughout the last you +know 20 25 years that they've been + + align:start position:0% +know 20 25 years that they've been + + + align:start position:0% +know 20 25 years that they've been +operating. um it is an like an essential + + align:start position:0% +operating. um it is an like an essential + + + align:start position:0% +operating. um it is an like an essential +part of our software infrastructure. Um + + align:start position:0% +part of our software infrastructure. Um + + + align:start position:0% +part of our software infrastructure. Um +and um I don't like I don't know does + + align:start position:0% +and um I don't like I don't know does + + + align:start position:0% +and um I don't like I don't know does +the idea that you are are participating + + align:start position:0% +the idea that you are are participating + + + align:start position:0% +the idea that you are are participating +in experiments all the time when you go + + align:start position:0% +in experiments all the time when you go + + + align:start position:0% +in experiments all the time when you go +Amazon shopping like does that does does + + align:start position:0% +Amazon shopping like does that does does + + + align:start position:0% +Amazon shopping like does that does does +that have the same level of creepiness + + align:start position:0% +that have the same level of creepiness + + + align:start position:0% +that have the same level of creepiness +to you like for some it's like yeah Jeff + + align:start position:0% +to you like for some it's like yeah Jeff + + + align:start position:0% +to you like for some it's like yeah Jeff +Bezos do whatever you want but but like + + align:start position:0% +Bezos do whatever you want but but like + + + align:start position:0% +Bezos do whatever you want but but like +but you know but but we feel differently + + align:start position:0% +but you know but but we feel differently + + + align:start position:0% +but you know but but we feel differently +about Pearson for some reason. I have a + + align:start position:0% +about Pearson for some reason. I have a + + + align:start position:0% +about Pearson for some reason. I have a +question about like beyond the like is + + align:start position:0% +question about like beyond the like is + + + align:start position:0% +question about like beyond the like is +this creepy or not creepy question but + + align:start position:0% +this creepy or not creepy question but + + + align:start position:0% +this creepy or not creepy question but +like if I'm a I have decided to buy a + + align:start position:0% +like if I'm a I have decided to buy a + + + align:start position:0% +like if I'm a I have decided to buy a +product like I'm paying to use Amazon or + + align:start position:0% +product like I'm paying to use Amazon or + + + align:start position:0% +product like I'm paying to use Amazon or +I'm paying to use Pearson and with that + + align:start position:0% +I'm paying to use Pearson and with that + + + align:start position:0% +I'm paying to use Pearson and with that +is the assumption that like I understand + + align:start position:0% +is the assumption that like I understand + + + align:start position:0% +is the assumption that like I understand +the thing I am buying because you + + align:start position:0% +the thing I am buying because you + + + align:start position:0% +the thing I am buying because you +pitched it to a certain way and I will + + align:start position:0% +pitched it to a certain way and I will + + + align:start position:0% +pitched it to a certain way and I will +get it. So then like how does the + + align:start position:0% +get it. So then like how does the + + + align:start position:0% +get it. So then like how does the +question of like are you allowed or not + + align:start position:0% +question of like are you allowed or not + + + align:start position:0% +question of like are you allowed or not +allowed to do this go from there? And it + + align:start position:0% +allowed to do this go from there? And it + + + align:start position:0% +allowed to do this go from there? And it +would be a and it would be a a huge + + align:start position:0% +would be a and it would be a a huge + + + align:start position:0% +would be a and it would be a a huge +difference from historical educational + + align:start position:0% +difference from historical educational + + + align:start position:0% +difference from historical educational +curriculum material purchases. Like it + + align:start position:0% +curriculum material purchases. Like it + + + align:start position:0% +curriculum material purchases. Like it +used to be, you know, like I bought uh + + align:start position:0% +used to be, you know, like I bought uh + + + align:start position:0% +used to be, you know, like I bought uh +you know, H Hotton Mifflin biology eth + + align:start position:0% +you know, H Hotton Mifflin biology eth + + + align:start position:0% +you know, H Hotton Mifflin biology eth +edition and I just know exactly what's + + align:start position:0% +edition and I just know exactly what's + + + align:start position:0% +edition and I just know exactly what's +in eth edition. Like and in fact, you + + align:start position:0% +in eth edition. Like and in fact, you + + + align:start position:0% +in eth edition. Like and in fact, you +know, the salesperson is going to come + + align:start position:0% +know, the salesperson is going to come + + + align:start position:0% +know, the salesperson is going to come +back when ninth edition's going to come + + align:start position:0% +back when ninth edition's going to come + + + align:start position:0% +back when ninth edition's going to come +out and they're going to be like, here's + + align:start position:0% +out and they're going to be like, here's + + + align:start position:0% +out and they're going to be like, here's +what's different about ninth edition, + + align:start position:0% +what's different about ninth edition, + + + align:start position:0% +what's different about ninth edition, +why you could buy it. And I might be + + align:start position:0% +why you could buy it. And I might be + + + align:start position:0% +why you could buy it. And I might be +like, no, I don't like what you did in + + align:start position:0% +like, no, I don't like what you did in + + + align:start position:0% +like, no, I don't like what you did in +ninth edition. um I'm going to switch to + + align:start position:0% +ninth edition. um I'm going to switch to + + + align:start position:0% +ninth edition. um I'm going to switch to +a different company's products because + + align:start position:0% +a different company's products because + + + align:start position:0% +a different company's products because +these these improvements are not + + align:start position:0% +these these improvements are not + + + align:start position:0% +these these improvements are not +improvements. Um yeah. Um under what + + align:start position:0% +improvements. Um yeah. Um under what + + + align:start position:0% +improvements. Um yeah. Um under what +circumstances should companies be able + + align:start position:0% +circumstances should companies be able + + + align:start position:0% +circumstances should companies be able +to dynamically improve their educational + + align:start position:0% +to dynamically improve their educational + + + align:start position:0% +to dynamically improve their educational +products? Um what kind of information + + align:start position:0% +products? Um what kind of information + + + align:start position:0% +products? Um what kind of information +should they make accessible about that? + + align:start position:0% +should they make accessible about that? + + + align:start position:0% +should they make accessible about that? +Um should they tell families? Should + + align:start position:0% +Um should they tell families? Should + + + align:start position:0% +Um should they tell families? Should +they tell educators? Should they tell + + align:start position:0% +they tell educators? Should they tell + + + align:start position:0% +they tell educators? Should they tell +you know my people could come up with + + align:start position:0% +you know my people could come up with + + + align:start position:0% +you know my people could come up with +different answer to these questions. Um, + + align:start position:0% +different answer to these questions. Um, + + + align:start position:0% +different answer to these questions. Um, +I think actually publishing a bunch of + + align:start position:0% +I think actually publishing a bunch of + + + align:start position:0% +I think actually publishing a bunch of +that information is probably enormously + + align:start position:0% +that information is probably enormously + + + align:start position:0% +that information is probably enormously +important, but not to parents and + + align:start position:0% +important, but not to parents and + + + align:start position:0% +important, but not to parents and +teachers and educators. Parents and + + align:start position:0% +teachers and educators. Parents and + + + align:start position:0% +teachers and educators. Parents and +teachers and educators have no time to + + align:start position:0% +teachers and educators have no time to + + + align:start position:0% +teachers and educators have no time to +be like tracking how your Pearson + + align:start position:0% +be like tracking how your Pearson + + + align:start position:0% +be like tracking how your Pearson +computer science like practice problems + + align:start position:0% +computer science like practice problems + + + align:start position:0% +computer science like practice problems +are changing. Um, there are specialized + + align:start position:0% +are changing. Um, there are specialized + + + align:start position:0% +are changing. Um, there are specialized +advocates across the country who focus + + align:start position:0% +advocates across the country who focus + + + align:start position:0% +advocates across the country who focus +on education, who focus on student + + align:start position:0% +on education, who focus on student + + + align:start position:0% +on education, who focus on student +privacy or other kinds of things who + + align:start position:0% +privacy or other kinds of things who + + + align:start position:0% +privacy or other kinds of things who +like actually would have the time and + + align:start position:0% +like actually would have the time and + + + align:start position:0% +like actually would have the time and +expertise to follow those audit records. + + align:start position:0% +expertise to follow those audit records. + + + align:start position:0% +expertise to follow those audit records. +Um but like you know if we started + + align:start position:0% +Um but like you know if we started + + + align:start position:0% +Um but like you know if we started +sending home a notice to parents every + + align:start position:0% +sending home a notice to parents every + + + align:start position:0% +sending home a notice to parents every +time a you know a company who used one + + align:start position:0% +time a you know a company who used one + + + align:start position:0% +time a you know a company who used one +of their products was conducting an + + align:start position:0% +of their products was conducting an + + + align:start position:0% +of their products was conducting an +experiment people like it would just be + + align:start position:0% +experiment people like it would just be + + + align:start position:0% +experiment people like it would just be +you know the the back it would be the + + align:start position:0% +you know the the back it would be the + + + align:start position:0% +you know the the back it would be the +terms and service conditions of your um + + align:start position:0% +terms and service conditions of your um + + + align:start position:0% +terms and service conditions of your um +presumably too by the way um it's it's + + align:start position:0% +presumably too by the way um it's it's + + + align:start position:0% +presumably too by the way um it's it's +very unlikely that when whatever school + + align:start position:0% +very unlikely that when whatever school + + + align:start position:0% +very unlikely that when whatever school +bought this Pearson product presumably + + align:start position:0% +bought this Pearson product presumably + + + align:start position:0% +bought this Pearson product presumably +that like their lawyers are competent + + align:start position:0% +that like their lawyers are competent + + + align:start position:0% +that like their lawyers are competent +and they made them sign a purchase and + + align:start position:0% +and they made them sign a purchase and + + + align:start position:0% +and they made them sign a purchase and +sale agreement that included these kinds + + align:start position:0% +sale agreement that included these kinds + + + align:start position:0% +sale agreement that included these kinds +of conditions in them. Although it's + + align:start position:0% +of conditions in them. Although it's + + + align:start position:0% +of conditions in them. Although it's +also not it's also the case that like + + align:start position:0% +also not it's also the case that like + + + align:start position:0% +also not it's also the case that like +you know the researchers who did this + + align:start position:0% +you know the researchers who did this + + + align:start position:0% +you know the researchers who did this +thing didn't sit down with these schools + + align:start position:0% +thing didn't sit down with these schools + + + align:start position:0% +thing didn't sit down with these schools +and are like let me tell you what we're + + align:start position:0% +and are like let me tell you what we're + + + align:start position:0% +and are like let me tell you what we're +doing in the next phase so that you you + + align:start position:0% +doing in the next phase so that you you + + + align:start position:0% +doing in the next phase so that you you +know I mean they might I think in this + + align:start position:0% +know I mean they might I think in this + + + align:start position:0% +know I mean they might I think in this +case they didn't give them much + + align:start position:0% +case they didn't give them much + + + align:start position:0% +case they didn't give them much +indication. Um + + align:start position:0% +indication. Um + + + align:start position:0% +indication. Um +um would it be like like I guess back to + + align:start position:0% +um would it be like like I guess back to + + + align:start position:0% +um would it be like like I guess back to +the conversation of like if it's like + + align:start position:0% +the conversation of like if it's like + + + align:start position:0% +the conversation of like if it's like +creepy or not. Do you think it might + + align:start position:0% +creepy or not. Do you think it might + + + align:start position:0% +creepy or not. Do you think it might +have anything to do with like the + + align:start position:0% +have anything to do with like the + + + align:start position:0% +have anything to do with like the +illusion of choice that you're given? + + align:start position:0% +illusion of choice that you're given? + + + align:start position:0% +illusion of choice that you're given? +Like for example, like if you're on + + align:start position:0% +Like for example, like if you're on + + + align:start position:0% +Like for example, like if you're on +Amazon or something, you can or like if + + align:start position:0% +Amazon or something, you can or like if + + + align:start position:0% +Amazon or something, you can or like if +if if you're on an app, you have the + + align:start position:0% +if if you're on an app, you have the + + + align:start position:0% +if if you're on an app, you have the +choice like sometimes not to update the + + align:start position:0% +choice like sometimes not to update the + + + align:start position:0% +choice like sometimes not to update the +app and just stay on the previous y + + align:start position:0% +app and just stay on the previous y + + + align:start position:0% +app and just stay on the previous y +setting or like if you have something + + align:start position:0% +setting or like if you have something + + + align:start position:0% +setting or like if you have something +like Amazon, like you can not use Amazon + + align:start position:0% +like Amazon, like you can not use Amazon + + + align:start position:0% +like Amazon, like you can not use Amazon +or like you you're you're perceiving it + + align:start position:0% +or like you you're you're perceiving it + + + align:start position:0% +or like you you're you're perceiving it +as like you're choosing to opt into + + align:start position:0% +as like you're choosing to opt into + + + align:start position:0% +as like you're choosing to opt into +that. Well, like in a situation where + + align:start position:0% +that. Well, like in a situation where + + + align:start position:0% +that. Well, like in a situation where +like you have to use a certain + + align:start position:0% +like you have to use a certain + + + align:start position:0% +like you have to use a certain +technology in school, like you could + + align:start position:0% +technology in school, like you could + + + align:start position:0% +technology in school, like you could +argue that like this student doesn't + + align:start position:0% +argue that like this student doesn't + + + align:start position:0% +argue that like this student doesn't +have a choice to opt out of this if they + + align:start position:0% +have a choice to opt out of this if they + + + align:start position:0% +have a choice to opt out of this if they +like and you could and you could see + + align:start position:0% +like and you could and you could see + + + align:start position:0% +like and you could and you could see +that choice operating at different + + align:start position:0% +that choice operating at different + + + align:start position:0% +that choice operating at different +levels. So, a grade school student has + + align:start position:0% +levels. So, a grade school student has + + + align:start position:0% +levels. So, a grade school student has +zero choice about whether or not to go + + align:start position:0% +zero choice about whether or not to go + + + align:start position:0% +zero choice about whether or not to go +to grade school. Every college student + + align:start position:0% +to grade school. Every college student + + + align:start position:0% +to grade school. Every college student +chose to go to college. Um, now sort of + + align:start position:0% +chose to go to college. Um, now sort of + + + align:start position:0% +chose to go to college. Um, now sort of +like once you've chosen to go to + + align:start position:0% +like once you've chosen to go to + + + align:start position:0% +like once you've chosen to go to +college, it doesn't it doesn't feel like + + align:start position:0% +college, it doesn't it doesn't feel like + + + align:start position:0% +college, it doesn't it doesn't feel like +that should mean you have to accept + + align:start position:0% +that should mean you have to accept + + + align:start position:0% +that should mean you have to accept +everything that comes along with + + align:start position:0% +everything that comes along with + + + align:start position:0% +everything that comes along with +college. Um, although again like you + + align:start position:0% +college. Um, although again like you + + + align:start position:0% +college. Um, although again like you +know you don't like like you know you + + align:start position:0% +know you don't like like you know you + + + align:start position:0% +know you don't like like you know you +could you could choose some majors over + + align:start position:0% +could you could choose some majors over + + + align:start position:0% +could you could choose some majors over +other majors based on the technology. + + align:start position:0% +other majors based on the technology. + + + align:start position:0% +other majors based on the technology. +You choose some classes over classes. Um + + align:start position:0% +You choose some classes over classes. Um + + + align:start position:0% +You choose some classes over classes. Um +the moment in recently in which some of + + align:start position:0% +the moment in recently in which some of + + + align:start position:0% +the moment in recently in which some of +this most came into focus was when + + align:start position:0% +this most came into focus was when + + + align:start position:0% +this most came into focus was when +schools started requiring students to + + align:start position:0% +schools started requiring students to + + + align:start position:0% +schools started requiring students to +adopt um proctoring software. Um so + + align:start position:0% +adopt um proctoring software. Um so + + + align:start position:0% +adopt um proctoring software. Um so +probably none of you have have any of + + align:start position:0% +probably none of you have have any of + + + align:start position:0% +probably none of you have have any of +you ever taken a remotely proctored test + + align:start position:0% +you ever taken a remotely proctored test + + + align:start position:0% +you ever taken a remotely proctored test +um at MIT? + + align:start position:0% +um at MIT? + + + align:start position:0% +um at MIT? +Where where did you take a remotely + + align:start position:0% +Where where did you take a remotely + + + align:start position:0% +Where where did you take a remotely +proctor test at MIT? Uh I believe uh + + align:start position:0% +proctor test at MIT? Uh I believe uh + + + align:start position:0% +proctor test at MIT? Uh I believe uh +there was the ASC during my like + + align:start position:0% +there was the ASC during my like + + + align:start position:0% +there was the ASC during my like +freshman like starting year. They used + + align:start position:0% +freshman like starting year. They used + + + align:start position:0% +freshman like starting year. They used +like some weird proctoring software for + + align:start position:0% +like some weird proctoring software for + + + align:start position:0% +like some weird proctoring software for +that where you had to like like take + + align:start position:0% +that where you had to like like take + + + align:start position:0% +that where you had to like like take +your webcam or take your laptop or + + align:start position:0% +your webcam or take your laptop or + + + align:start position:0% +your webcam or take your laptop or +webcam show the rest of your room all + + align:start position:0% +webcam show the rest of your room all + + + align:start position:0% +webcam show the rest of your room all +these kinds of things essentially. Good. + + align:start position:0% +these kinds of things essentially. Good. + + + align:start position:0% +these kinds of things essentially. Good. +Um so uh there are a number of cases + + align:start position:0% +Um so uh there are a number of cases + + + align:start position:0% +Um so uh there are a number of cases +where um for instance uh universities + + align:start position:0% +where um for instance uh universities + + + align:start position:0% +where um for instance uh universities +implemented this kind of proctoring + + align:start position:0% +implemented this kind of proctoring + + + align:start position:0% +implemented this kind of proctoring +software mid-semester + + align:start position:0% +software mid-semester + + + align:start position:0% +software mid-semester +um and in fact implemented it + + align:start position:0% +um and in fact implemented it + + + align:start position:0% +um and in fact implemented it +mid-semester and required students to + + align:start position:0% +mid-semester and required students to + + + align:start position:0% +mid-semester and required students to +pay for it. Um that like you can imagine + + align:start position:0% +pay for it. Um that like you can imagine + + + align:start position:0% +pay for it. Um that like you can imagine +that as a set of circumstances which + + align:start position:0% +that as a set of circumstances which + + + align:start position:0% +that as a set of circumstances which +like most draws the eye of people + + align:start position:0% +like most draws the eye of people + + + align:start position:0% +like most draws the eye of people +because like I've like I've already + + align:start position:0% +because like I've like I've already + + + align:start position:0% +because like I've like I've already +committed to this college, I've already + + align:start position:0% +committed to this college, I've already + + + align:start position:0% +committed to this college, I've already +committed to this course. Now you're + + align:start position:0% +committed to this course. Now you're + + + align:start position:0% +committed to this course. Now you're +making me you know essentially install + + align:start position:0% +making me you know essentially install + + + align:start position:0% +making me you know essentially install +spyware on my machine. um you know and + + align:start position:0% +spyware on my machine. um you know and + + + align:start position:0% +spyware on my machine. um you know and +then like I don't know have some random + + align:start position:0% +then like I don't know have some random + + + align:start position:0% +then like I don't know have some random +person see what my dorm room looks like + + align:start position:0% +person see what my dorm room looks like + + + align:start position:0% +person see what my dorm room looks like +and other kinds of or my bedroom you + + align:start position:0% +and other kinds of or my bedroom you + + + align:start position:0% +and other kinds of or my bedroom you +know these sort of things seem creepy um + + align:start position:0% +know these sort of things seem creepy um + + + align:start position:0% +know these sort of things seem creepy um +arguably maybe they're less creepy the + + align:start position:0% +arguably maybe they're less creepy the + + + align:start position:0% +arguably maybe they're less creepy the +more that they're disclosed to people + + align:start position:0% +more that they're disclosed to people + + + align:start position:0% +more that they're disclosed to people +over time although I also use the phrase + + align:start position:0% +over time although I also use the phrase + + + align:start position:0% +over time although I also use the phrase +illusion of choice um because in fact + + align:start position:0% +illusion of choice um because in fact + + + align:start position:0% +illusion of choice um because in fact +for lots of things you know for instance + + align:start position:0% +for lots of things you know for instance + + + align:start position:0% +for lots of things you know for instance +like every there are no cell service + + align:start position:0% +like every there are no cell service + + + align:start position:0% +like every there are no cell service +companies that compete on the basis of + + align:start position:0% +companies that compete on the basis of + + + align:start position:0% +companies that compete on the basis of +not selling your location data um like + + align:start position:0% +not selling your location data um like + + + align:start position:0% +not selling your location data um like +it is not really a choice to not have a + + align:start position:0% +it is not really a choice to not have a + + + align:start position:0% +it is not really a choice to not have a +mobile phone um anymore in society and + + align:start position:0% +mobile phone um anymore in society and + + + align:start position:0% +mobile phone um anymore in society and +so you're not really ch like um you know + + align:start position:0% +so you're not really ch like um you know + + + align:start position:0% +so you're not really ch like um you know +in theory that's a choice but it's not + + align:start position:0% +in theory that's a choice but it's not + + + align:start position:0% +in theory that's a choice but it's not +really one you know going to college + + align:start position:0% +really one you know going to college + + + align:start position:0% +really one you know going to college +like for some people is not really a + + align:start position:0% +like for some people is not really a + + + align:start position:0% +like for some people is not really a +choice like you're going to have to go + + align:start position:0% +choice like you're going to have to go + + + align:start position:0% +choice like you're going to have to go +to choice to have the life that you want + + align:start position:0% +to choice to have the life that you want + + + align:start position:0% +to choice to have the life that you want +and things like that um uh but I do but + + align:start position:0% +and things like that um uh but I do but + + + align:start position:0% +and things like that um uh but I do but +I do think K12 students in particular + + align:start position:0% +I do think K12 students in particular + + + align:start position:0% +I do think K12 students in particular +now another sort of unusual feature of + + align:start position:0% +now another sort of unusual feature of + + + align:start position:0% +now another sort of unusual feature of +this is that and it goes back to this + + align:start position:0% +this is that and it goes back to this + + + align:start position:0% +this is that and it goes back to this +sort of data collection um you know K12 + + align:start position:0% +sort of data collection um you know K12 + + + align:start position:0% +sort of data collection um you know K12 +many K12 students across the country are + + align:start position:0% +many K12 students across the country are + + + align:start position:0% +many K12 students across the country are +mandated to create a Google account. Um, + + align:start position:0% +mandated to create a Google account. Um, + + + align:start position:0% +mandated to create a Google account. Um, +and then Google has reams of data about + + align:start position:0% +and then Google has reams of data about + + + align:start position:0% +and then Google has reams of data about +all these kinds of things that they uh + + align:start position:0% +all these kinds of things that they uh + + + align:start position:0% +all these kinds of things that they uh +that they that they do with that data. + + align:start position:0% +that they that they do with that data. + + + align:start position:0% +that they that they do with that data. +Um, and uh um you know and there might + + align:start position:0% +Um, and uh um you know and there might + + + align:start position:0% +Um, and uh um you know and there might +be various ways that again you know so + + align:start position:0% +be various ways that again you know so + + + align:start position:0% +be various ways that again you know so +should like to what extent these things + + align:start position:0% +should like to what extent these things + + + align:start position:0% +should like to what extent these things +are legitimate or not. It's probably + + align:start position:0% +are legitimate or not. It's probably + + + align:start position:0% +are legitimate or not. It's probably +much less of a debate these days, but + + align:start position:0% +much less of a debate these days, but + + + align:start position:0% +much less of a debate these days, but +definitely when schools were first + + align:start position:0% +definitely when schools were first + + + align:start position:0% +definitely when schools were first +adopting Google for education. Um, it + + align:start position:0% +adopting Google for education. Um, it + + + align:start position:0% +adopting Google for education. Um, it +was not uncommon to hear that school + + align:start position:0% +was not uncommon to hear that school + + + align:start position:0% +was not uncommon to hear that school +boards had uh really vigorous complaints + + align:start position:0% +boards had uh really vigorous complaints + + + align:start position:0% +boards had uh really vigorous complaints +from parents. And oftentimes the com the + + align:start position:0% +from parents. And oftentimes the com the + + + align:start position:0% +from parents. And oftentimes the com the +most vigorous complaints came from + + align:start position:0% +most vigorous complaints came from + + + align:start position:0% +most vigorous complaints came from +parents who worked in the software + + align:start position:0% +parents who worked in the software + + + align:start position:0% +parents who worked in the software +industry. Um, like do like I know who + + align:start position:0% +industry. Um, like do like I know who + + + align:start position:0% +industry. Um, like do like I know who +these people are. I work for these + + align:start position:0% +these people are. I work for these + + + align:start position:0% +these people are. I work for these +companies. Um, how are you going to make + + align:start position:0% +companies. Um, how are you going to make + + + align:start position:0% +companies. Um, how are you going to make +my kid do these kinds of things? Um, + + align:start position:0% +my kid do these kinds of things? Um, + + + align:start position:0% +my kid do these kinds of things? Um, +let's talk about another one of these + + align:start position:0% +let's talk about another one of these + + + align:start position:0% +let's talk about another one of these +cases. + + align:start position:0% +cases. + + + align:start position:0% +cases. +Um so another story that you read about + + align:start position:0% +Um so another story that you read about + + + align:start position:0% +Um so another story that you read about +was in Bloom um in 2013. So um the Gates + + align:start position:0% +was in Bloom um in 2013. So um the Gates + + + align:start position:0% +was in Bloom um in 2013. So um the Gates +Foundation along with a number of other + + align:start position:0% +Foundation along with a number of other + + + align:start position:0% +Foundation along with a number of other +organizations, Wireless Generation, some + + align:start position:0% +organizations, Wireless Generation, some + + + align:start position:0% +organizations, Wireless Generation, some +other people sort of observed like man + + align:start position:0% +other people sort of observed like man + + + align:start position:0% +other people sort of observed like man +here's a weird thing. um + + align:start position:0% +here's a weird thing. um + + + align:start position:0% +here's a weird thing. um +companies who serve schools have tons of + + align:start position:0% +companies who serve schools have tons of + + + align:start position:0% +companies who serve schools have tons of +data about students and sort of the only + + align:start position:0% +data about students and sort of the only + + + align:start position:0% +data about students and sort of the only +way we can make this system work or the + + align:start position:0% +way we can make this system work or the + + + align:start position:0% +way we can make this system work or the +way the system currently works is like + + align:start position:0% +way the system currently works is like + + + align:start position:0% +way the system currently works is like +some company goes to a school district + + align:start position:0% +some company goes to a school district + + + align:start position:0% +some company goes to a school district +and says we'll operate this service for + + align:start position:0% +and says we'll operate this service for + + + align:start position:0% +and says we'll operate this service for +you but here's all the data we need. Um + + align:start position:0% +you but here's all the data we need. Um + + + align:start position:0% +you but here's all the data we need. Um +and the schools are like yeah okay deal. + + align:start position:0% +and the schools are like yeah okay deal. + + + align:start position:0% +and the schools are like yeah okay deal. +Um, and if you make enough of those + + align:start position:0% +Um, and if you make enough of those + + + align:start position:0% +Um, and if you make enough of those +kinds of arrangements, I mean, we + + align:start position:0% +kinds of arrangements, I mean, we + + + align:start position:0% +kinds of arrangements, I mean, we +another exercise we could do here is + + align:start position:0% +another exercise we could do here is + + + align:start position:0% +another exercise we could do here is +like make a list of all of the + + align:start position:0% +like make a list of all of the + + + align:start position:0% +like make a list of all of the +educational software products that + + align:start position:0% +educational software products that + + + align:start position:0% +educational software products that +you've ever used in schools. Um, and you + + align:start position:0% +you've ever used in schools. Um, and you + + + align:start position:0% +you've ever used in schools. Um, and you +all could probably come up with lists of + + align:start position:0% +all could probably come up with lists of + + + align:start position:0% +all could probably come up with lists of +like dozens or more software products + + align:start position:0% +like dozens or more software products + + + align:start position:0% +like dozens or more software products +that you've encountered in some kind of + + align:start position:0% +that you've encountered in some kind of + + + align:start position:0% +that you've encountered in some kind of +way. Those are all people that have some + + align:start position:0% +way. Those are all people that have some + + + align:start position:0% +way. Those are all people that have some +kind of data about you somewhere. Um, + + align:start position:0% +kind of data about you somewhere. Um, + + + align:start position:0% +kind of data about you somewhere. Um, +that seems like a terrible + + align:start position:0% +that seems like a terrible + + + align:start position:0% +that seems like a terrible +infrastructure. Like you require people + + align:start position:0% +infrastructure. Like you require people + + + align:start position:0% +infrastructure. Like you require people +to go to schools. um the schools make + + align:start position:0% +to go to schools. um the schools make + + + align:start position:0% +to go to schools. um the schools make +contracts with third parties to provide + + align:start position:0% +contracts with third parties to provide + + + align:start position:0% +contracts with third parties to provide +services and all those third parties end + + align:start position:0% +services and all those third parties end + + + align:start position:0% +services and all those third parties end +up with sort of shards of data. Um so + + align:start position:0% +up with sort of shards of data. Um so + + + align:start position:0% +up with sort of shards of data. Um so +the idea of inbloom + + align:start position:0% +the idea of inbloom + + + align:start position:0% +the idea of inbloom +was let's concentrate all of the data + + align:start position:0% +was let's concentrate all of the data + + + align:start position:0% +was let's concentrate all of the data +about students in one nonprofit + + align:start position:0% +about students in one nonprofit + + + align:start position:0% +about students in one nonprofit +organization. Um let's get let's you + + align:start position:0% +organization. Um let's get let's you + + + align:start position:0% +organization. Um let's get let's you +know it be something along the lines of + + align:start position:0% +know it be something along the lines of + + + align:start position:0% +know it be something along the lines of +trying to generate the kind of data set + + align:start position:0% +trying to generate the kind of data set + + + align:start position:0% +trying to generate the kind of data set +that the Norwegian study that I just + + align:start position:0% +that the Norwegian study that I just + + + align:start position:0% +that the Norwegian study that I just +showed you would require. Um like let's + + align:start position:0% +showed you would require. Um like let's + + + align:start position:0% +showed you would require. Um like let's +get all their student records. let's get + + align:start position:0% +get all their student records. let's get + + + align:start position:0% +get all their student records. let's get +all their let's get let's get all all + + align:start position:0% +all their let's get let's get all all + + + align:start position:0% +all their let's get let's get all all +their app usage let's get all those + + align:start position:0% +their app usage let's get all those + + + align:start position:0% +their app usage let's get all those +kinds of things um and have a nonprofit + + align:start position:0% +kinds of things um and have a nonprofit + + + align:start position:0% +kinds of things um and have a nonprofit +entity hold on to that data um and in + + align:start position:0% +entity hold on to that data um and in + + + align:start position:0% +entity hold on to that data um and in +particular let's make it so that instead + + align:start position:0% +particular let's make it so that instead + + + align:start position:0% +particular let's make it so that instead +of um companies making arrangements with + + align:start position:0% +of um companies making arrangements with + + + align:start position:0% +of um companies making arrangements with +individual school districts to get + + align:start position:0% +individual school districts to get + + + align:start position:0% +individual school districts to get +access to the data they need they just + + align:start position:0% +access to the data they need they just + + + align:start position:0% +access to the data they need they just +get in touch with this nonprofit + + align:start position:0% +get in touch with this nonprofit + + + align:start position:0% +get in touch with this nonprofit +um now what could potentially be good + + align:start position:0% +um now what could potentially be good + + + align:start position:0% +um now what could potentially be good +about having a nonprofit intermediary + + align:start position:0% +about having a nonprofit intermediary + + + align:start position:0% +about having a nonprofit intermediary +between schools and third parties that + + align:start position:0% +between schools and third parties that + + + align:start position:0% +between schools and third parties that +want to provide services to schools but + + align:start position:0% +want to provide services to schools but + + + align:start position:0% +want to provide services to schools but +require data to do + + align:start position:0% + + + + align:start position:0% + +it. I think public perception is that + + align:start position:0% +it. I think public perception is that + + + align:start position:0% +it. I think public perception is that +nonprofits are a lot more trustworthy + + align:start position:0% +nonprofits are a lot more trustworthy + + + align:start position:0% +nonprofits are a lot more trustworthy +than for-profit companies so people + + align:start position:0% +than for-profit companies so people + + + align:start position:0% +than for-profit companies so people +won't get as freaked out about it. Yeah. + + align:start position:0% +won't get as freaked out about it. Yeah. + + + align:start position:0% +won't get as freaked out about it. Yeah. +Good. So, do you want like Pearson to + + align:start position:0% +Good. So, do you want like Pearson to + + + align:start position:0% +Good. So, do you want like Pearson to +have all of this data or do you want, + + align:start position:0% +have all of this data or do you want, + + + align:start position:0% +have all of this data or do you want, +you know, InBloom um, you know, funded + + align:start position:0% +you know, InBloom um, you know, funded + + + align:start position:0% +you know, InBloom um, you know, funded +by a consortium of state departments of + + align:start position:0% +by a consortium of state departments of + + + align:start position:0% +by a consortium of state departments of +I mean, it was funded by the Gates + + align:start position:0% +I mean, it was funded by the Gates + + + align:start position:0% +I mean, it was funded by the Gates +Foundation, but like sponsored by a set + + align:start position:0% +Foundation, but like sponsored by a set + + + align:start position:0% +Foundation, but like sponsored by a set +of state departments of education to + + align:start position:0% +of state departments of education to + + + align:start position:0% +of state departments of education to +have this data. What else? + + align:start position:0% + + + + align:start position:0% + +I had a question like how it functions. + + align:start position:0% +I had a question like how it functions. + + + align:start position:0% +I had a question like how it functions. +So like if they have the data and then + + align:start position:0% +So like if they have the data and then + + + align:start position:0% +So like if they have the data and then +um like a company or some kind of + + align:start position:0% +um like a company or some kind of + + + align:start position:0% +um like a company or some kind of +researcher is trying to access it, do + + align:start position:0% +researcher is trying to access it, do + + + align:start position:0% +researcher is trying to access it, do +they have final say on like how it's + + align:start position:0% +they have final say on like how it's + + + align:start position:0% +they have final say on like how it's +being used or do they then go back to + + align:start position:0% +being used or do they then go back to + + + align:start position:0% +being used or do they then go back to +the schools? So as so the go so in bloom + + align:start position:0% +the schools? So as so the go so in bloom + + + align:start position:0% +the schools? So as so the go so in bloom +failed and we can talk about why it + + align:start position:0% +failed and we can talk about why it + + + align:start position:0% +failed and we can talk about why it +failed so you don't have to worry about + + align:start position:0% +failed so you don't have to worry about + + + align:start position:0% +failed so you don't have to worry about +it existing although I'll show you a new + + align:start position:0% +it existing although I'll show you a new + + + align:start position:0% +it existing although I'll show you a new +thing that showed up this past week + + align:start position:0% +thing that showed up this past week + + + align:start position:0% +thing that showed up this past week +which is remarkably similar. Um but I + + align:start position:0% +which is remarkably similar. Um but I + + + align:start position:0% +which is remarkably similar. Um but I +think some of the key value some of the + + align:start position:0% +think some of the key value some of the + + + align:start position:0% +think some of the key value some of the +key value proposition was that the + + align:start position:0% +key value proposition was that the + + + align:start position:0% +key value proposition was that the +companies would go to Inloom um and get + + align:start position:0% +companies would go to Inloom um and get + + + align:start position:0% +companies would go to Inloom um and get +just the data they need. What do you + + align:start position:0% +just the data they need. What do you + + + align:start position:0% +just the data they need. What do you +think InBloom would potentially be + + align:start position:0% +think InBloom would potentially be + + + align:start position:0% +think InBloom would potentially be +better at than schools might be + + align:start position:0% + + + + align:start position:0% + +raw data processing? Good. So, first of + + align:start position:0% +raw data processing? Good. So, first of + + + align:start position:0% +raw data processing? Good. So, first of +all, they're just like if if if your if + + align:start position:0% +all, they're just like if if if your if + + + align:start position:0% +all, they're just like if if if your if +your job is not to like, you know, teach + + align:start position:0% +your job is not to like, you know, teach + + + align:start position:0% +your job is not to like, you know, teach +kindergarten and Mandarin, but like just + + align:start position:0% +kindergarten and Mandarin, but like just + + + align:start position:0% +kindergarten and Mandarin, but like just +to process student data, you're probably + + align:start position:0% +to process student data, you're probably + + + align:start position:0% +to process student data, you're probably +going to be better at processing student + + align:start position:0% +going to be better at processing student + + + align:start position:0% +going to be better at processing student +data than this organization that has to + + align:start position:0% +data than this organization that has to + + + align:start position:0% +data than this organization that has to +like have a field hockey team and run + + align:start position:0% +like have a field hockey team and run + + + align:start position:0% +like have a field hockey team and run +buses and other kinds of things like + + align:start position:0% +buses and other kinds of things like + + + align:start position:0% +buses and other kinds of things like +that. + + align:start position:0% +that. + + + align:start position:0% +that. +Security is better, too, if that's your + + align:start position:0% +Security is better, too, if that's your + + + align:start position:0% +Security is better, too, if that's your +main focus. Why would there are 13,000 + + align:start position:0% +main focus. Why would there are 13,000 + + + align:start position:0% +main focus. Why would there are 13,000 +school districts in the United States of + + align:start position:0% +school districts in the United States of + + + align:start position:0% +school districts in the United States of +widely varying capacities in all kinds + + align:start position:0% +widely varying capacities in all kinds + + + align:start position:0% +widely varying capacities in all kinds +of IT things? It seems like an + + align:start position:0% +of IT things? It seems like an + + + align:start position:0% +of IT things? It seems like an +organization that is like just focused + + align:start position:0% +organization that is like just focused + + + align:start position:0% +organization that is like just focused +on IT things is going to be like we + + align:start position:0% +on IT things is going to be like we + + + align:start position:0% +on IT things is going to be like we +don't even like in a lot of ways if you + + align:start position:0% +don't even like in a lot of ways if you + + + align:start position:0% +don't even like in a lot of ways if you +have a society where a school has to be + + align:start position:0% +have a society where a school has to be + + + align:start position:0% +have a society where a school has to be +good at IT things you may not be + + align:start position:0% +good at IT things you may not be + + + align:start position:0% +good at IT things you may not be +organizing that society correctly. Um + + align:start position:0% +organizing that society correctly. Um + + + align:start position:0% +organizing that society correctly. Um +and so you can you know if you go to + + align:start position:0% +and so you can you know if you go to + + + align:start position:0% +and so you can you know if you go to +other countries you know during the + + align:start position:0% +other countries you know during the + + + align:start position:0% +other countries you know during the +pandemic like we had um schools + + align:start position:0% +pandemic like we had um schools + + + align:start position:0% +pandemic like we had um schools +provision laptops and hotspots to to + + align:start position:0% +provision laptops and hotspots to to + + + align:start position:0% +provision laptops and hotspots to to +students. Insane. There's no reason to + + align:start position:0% +students. Insane. There's no reason to + + + align:start position:0% +students. Insane. There's no reason to +think schools should be any good at + + align:start position:0% +think schools should be any good at + + + align:start position:0% +think schools should be any good at +that. um like there should be other + + align:start position:0% +that. um like there should be other + + + align:start position:0% +that. um like there should be other +institutions in society that are good at + + align:start position:0% +institutions in society that are good at + + + align:start position:0% +institutions in society that are good at +IT procurement like it it shouldn't be + + align:start position:0% +IT procurement like it it shouldn't be + + + align:start position:0% +IT procurement like it it shouldn't be +your local I mean I sometimes I would + + align:start position:0% +your local I mean I sometimes I would + + + align:start position:0% +your local I mean I sometimes I would +compare it to people like you know in + + align:start position:0% +compare it to people like you know in + + + align:start position:0% +compare it to people like you know in +the 19th century when we decided that + + align:start position:0% +the 19th century when we decided that + + + align:start position:0% +the 19th century when we decided that +every household in the United States + + align:start position:0% +every household in the United States + + + align:start position:0% +every household in the United States +should get or in the 20th century we + + align:start position:0% +should get or in the 20th century we + + + align:start position:0% +should get or in the 20th century we +decided every household in the United + + align:start position:0% +decided every household in the United + + + align:start position:0% +decided every household in the United +States should get electricity we like + + align:start position:0% +States should get electricity we like + + + align:start position:0% +States should get electricity we like +didn't go to the local school principal + + align:start position:0% +didn't go to the local school principal + + + align:start position:0% +didn't go to the local school principal +and be like so how are you going to run + + align:start position:0% +and be like so how are you going to run + + + align:start position:0% +and be like so how are you going to run +wires up the holler um you know we + + align:start position:0% +wires up the holler um you know we + + + align:start position:0% +wires up the holler um you know we +invented the TVA and other kinds of + + align:start position:0% +invented the TVA and other kinds of + + + align:start position:0% +invented the TVA and other kinds of +organizations that was really good at + + align:start position:0% +organizations that was really good at + + + align:start position:0% +organizations that was really good at +electrification um so that the schools + + align:start position:0% +electrification um so that the schools + + + align:start position:0% +electrification um so that the schools +didn't have to be good at + + align:start position:0% +didn't have to be good at + + + align:start position:0% +didn't have to be good at +electrification like electrification is + + align:start position:0% +electrification like electrification is + + + align:start position:0% +electrification like electrification is +is closer to you know provisioning + + align:start position:0% +is closer to you know provisioning + + + align:start position:0% +is closer to you know provisioning +broadband and laptops um than it is to + + align:start position:0% +broadband and laptops um than it is to + + + align:start position:0% +broadband and laptops um than it is to +other kinds of educational things. All + + align:start position:0% +other kinds of educational things. All + + + align:start position:0% +other kinds of educational things. All +right. So these institutions um could + + align:start position:0% +right. So these institutions um could + + + align:start position:0% +right. So these institutions um could +conceivably develop a whole bunch of + + align:start position:0% +conceivably develop a whole bunch of + + + align:start position:0% +conceivably develop a whole bunch of +expertise around data around privacy + + align:start position:0% +expertise around data around privacy + + + align:start position:0% +expertise around data around privacy +things like that. Um another thing that + + align:start position:0% +things like that. Um another thing that + + + align:start position:0% +things like that. Um another thing that +they could probably get pretty good at + + align:start position:0% +they could probably get pretty good at + + + align:start position:0% +they could probably get pretty good at +doing is only giving providers the exact + + align:start position:0% +doing is only giving providers the exact + + + align:start position:0% +doing is only giving providers the exact +data they need. Um, so schools have a + + align:start position:0% +data they need. Um, so schools have a + + + align:start position:0% +data they need. Um, so schools have a +tough time vetting like all of the data + + align:start position:0% +tough time vetting like all of the data + + + align:start position:0% +tough time vetting like all of the data +that they're making available to all + + align:start position:0% +that they're making available to all + + + align:start position:0% +that they're making available to all +their different providers. And so + + align:start position:0% +their different providers. And so + + + align:start position:0% +their different providers. And so +presumably, you know, they make + + align:start position:0% +presumably, you know, they make + + + align:start position:0% +presumably, you know, they make +arrangements and people just collect + + align:start position:0% +arrangements and people just collect + + + align:start position:0% +arrangements and people just collect +whatever. If there's a sort of + + align:start position:0% +whatever. If there's a sort of + + + align:start position:0% +whatever. If there's a sort of +intermediary in that collection process, + + align:start position:0% +intermediary in that collection process, + + + align:start position:0% +intermediary in that collection process, +you could imagine that InBloom could be + + align:start position:0% +you could imagine that InBloom could be + + + align:start position:0% +you could imagine that InBloom could be +pretty good at being like, "Yeah, + + align:start position:0% +pretty good at being like, "Yeah, + + + align:start position:0% +pretty good at being like, "Yeah, +Canvas, you just asked us for these 14 + + align:start position:0% +Canvas, you just asked us for these 14 + + + align:start position:0% +Canvas, you just asked us for these 14 +things, but I'm pretty sure to operate + + align:start position:0% +things, but I'm pretty sure to operate + + + align:start position:0% +things, but I'm pretty sure to operate +your system, you need these six." Um, so + + align:start position:0% +your system, you need these six." Um, so + + + align:start position:0% +your system, you need these six." Um, so +why don't you start with these six and + + align:start position:0% +why don't you start with these six and + + + align:start position:0% +why don't you start with these six and +see how you do from there. um and they + + align:start position:0% +see how you do from there. um and they + + + align:start position:0% +see how you do from there. um and they +might be able to do all kinds of other + + align:start position:0% +might be able to do all kinds of other + + + align:start position:0% +might be able to do all kinds of other +you know right now for Canvas to operate + + align:start position:0% +you know right now for Canvas to operate + + + align:start position:0% +you know right now for Canvas to operate +it needs to have um you know your actual + + align:start position:0% +it needs to have um you know your actual + + + align:start position:0% +it needs to have um you know your actual +email address and other kinds of things + + align:start position:0% +email address and other kinds of things + + + align:start position:0% +email address and other kinds of things +like that. You can imagine building all + + align:start position:0% +like that. You can imagine building all + + + align:start position:0% +like that. You can imagine building all +kinds of intermediary layers that that + + align:start position:0% +kinds of intermediary layers that that + + + align:start position:0% +kinds of intermediary layers that that +only hashed identifiers are passing on + + align:start position:0% +only hashed identifiers are passing on + + + align:start position:0% +only hashed identifiers are passing on +to these third parties and in Bloom + + align:start position:0% +to these third parties and in Bloom + + + align:start position:0% +to these third parties and in Bloom +collects all this. + + align:start position:0% +collects all this. + + + align:start position:0% +collects all this. +Um in Bloom fails um oh almost + + align:start position:0% +Um in Bloom fails um oh almost + + + align:start position:0% +Um in Bloom fails um oh almost +immediately. Um well here's a here's a + + align:start position:0% +immediately. Um well here's a here's a + + + align:start position:0% +immediately. Um well here's a here's a +few things that were written about it + + align:start position:0% +few things that were written about it + + + align:start position:0% +few things that were written about it +when it started. + + align:start position:0% +when it started. + + + align:start position:0% +when it started. +Um, nonprofit InBloom offers an internet + + align:start position:0% +Um, nonprofit InBloom offers an internet + + + align:start position:0% +Um, nonprofit InBloom offers an internet +database service that allows schools to + + align:start position:0% +database service that allows schools to + + + align:start position:0% +database service that allows schools to +store, track, and analyze data on school + + align:start position:0% +store, track, and analyze data on school + + + align:start position:0% +store, track, and analyze data on school +chunking. If you think about it, that + + align:start position:0% +chunking. If you think about it, that + + + align:start position:0% +chunking. If you think about it, that +information is more than just test + + align:start position:0% +information is more than just test + + + align:start position:0% +information is more than just test +scores. It's whether kids receive free + + align:start position:0% +scores. It's whether kids receive free + + + align:start position:0% +scores. It's whether kids receive free +lunch, a telling indicator of the + + align:start position:0% +lunch, a telling indicator of the + + + align:start position:0% +lunch, a telling indicator of the +family's finance. The time the school + + align:start position:0% +family's finance. The time the school + + + align:start position:0% +family's finance. The time the school +got no fight in the schoolyard. It could + + align:start position:0% +got no fight in the schoolyard. It could + + + align:start position:0% +got no fight in the schoolyard. It could +be a child's prescription medicine. Um, + + align:start position:0% +be a child's prescription medicine. Um, + + + align:start position:0% +be a child's prescription medicine. Um, +the upshot of storing all that data in + + align:start position:0% +the upshot of storing all that data in + + + align:start position:0% +the upshot of storing all that data in +one location is it could be used to + + align:start position:0% +one location is it could be used to + + + align:start position:0% +one location is it could be used to +tailor curricula to each child. If + + align:start position:0% +tailor curricula to each child. If + + + align:start position:0% +tailor curricula to each child. If +Johnny's data suggests he's a tactile + + align:start position:0% +Johnny's data suggests he's a tactile + + + align:start position:0% +Johnny's data suggests he's a tactile +learner, which is not true, there are no + + align:start position:0% +learner, which is not true, there are no + + + align:start position:0% +learner, which is not true, there are no +learning styles. Um, and he's failing + + align:start position:0% +learning styles. Um, and he's failing + + + align:start position:0% +learning styles. Um, and he's failing +math, Inloom's analytic action might + + align:start position:0% +math, Inloom's analytic action might + + + align:start position:0% +math, Inloom's analytic action might +suggest a particular teaching approach. + + align:start position:0% +suggest a particular teaching approach. + + + align:start position:0% +suggest a particular teaching approach. +Um, this is all about building + + align:start position:0% +Um, this is all about building + + + align:start position:0% +Um, this is all about building +personalized learning environments for + + align:start position:0% +personalized learning environments for + + + align:start position:0% +personalized learning environments for +kids. Um, but as more school districts + + align:start position:0% +kids. Um, but as more school districts + + + align:start position:0% +kids. Um, but as more school districts +team up with Inloom, including New York, + + align:start position:0% +team up with Inloom, including New York, + + + align:start position:0% +team up with Inloom, including New York, +parents are becoming increasingly vocal + + align:start position:0% +parents are becoming increasingly vocal + + + align:start position:0% +parents are becoming increasingly vocal +critics of the data collection. This + + align:start position:0% +critics of the data collection. This + + + align:start position:0% +critics of the data collection. This +information, I have no idea what it is. + + align:start position:0% +information, I have no idea what it is. + + + align:start position:0% +information, I have no idea what it is. +I have no idea who's using it, and I + + align:start position:0% +I have no idea who's using it, and I + + + align:start position:0% +I have no idea who's using it, and I +have no idea for what purpose. Um + + align:start position:0% +have no idea for what purpose. Um + + + align:start position:0% +have no idea for what purpose. Um +uh so part of what the existence of + + align:start position:0% +uh so part of what the existence of + + + align:start position:0% +uh so part of what the existence of +InBloom did was to like was to go to + + align:start position:0% +InBloom did was to like was to go to + + + align:start position:0% +InBloom did was to like was to go to +communities and be like, "Hey, you know + + align:start position:0% +communities and be like, "Hey, you know + + + align:start position:0% +communities and be like, "Hey, you know +what's happening right now? There's tons + + align:start position:0% +what's happening right now? There's tons + + + align:start position:0% +what's happening right now? There's tons +of data being collected about children." + + align:start position:0% +of data being collected about children." + + + align:start position:0% +of data being collected about children." +Um and we're going to put it all in one + + align:start position:0% +Um and we're going to put it all in one + + + align:start position:0% +Um and we're going to put it all in one +place. You can imagine that, you know, + + align:start position:0% +place. You can imagine that, you know, + + + align:start position:0% +place. You can imagine that, you know, +like for people like me, they're like, + + align:start position:0% +like for people like me, they're like, + + + align:start position:0% +like for people like me, they're like, +"Yeah, that's a great idea. We're + + align:start position:0% +"Yeah, that's a great idea. We're + + + align:start position:0% +"Yeah, that's a great idea. We're +totally going to be able to have all + + align:start position:0% +totally going to be able to have all + + + align:start position:0% +totally going to be able to have all +these benefits." But like there's tons + + align:start position:0% +these benefits." But like there's tons + + + align:start position:0% +these benefits." But like there's tons +of data being collected about children + + align:start position:0% +of data being collected about children + + + align:start position:0% +of data being collected about children +and it's all going to be put in one + + align:start position:0% +and it's all going to be put in one + + + align:start position:0% +and it's all going to be put in one +place. is like not actually as it turns + + align:start position:0% +place. is like not actually as it turns + + + align:start position:0% +place. is like not actually as it turns +out a very popular public pitch. Um in + + align:start position:0% +out a very popular public pitch. Um in + + + align:start position:0% +out a very popular public pitch. Um in +Bloom CEO is quick to point out that the + + align:start position:0% +Bloom CEO is quick to point out that the + + + align:start position:0% +Bloom CEO is quick to point out that the +company isn't collecting data the this + + align:start position:0% +company isn't collecting data the this + + + align:start position:0% +company isn't collecting data the this +isn't collecting data the school + + align:start position:0% +isn't collecting data the school + + + align:start position:0% +isn't collecting data the school +districts don't already have. It's just + + align:start position:0% +districts don't already have. It's just + + + align:start position:0% +districts don't already have. It's just +providing a one-stop dot to make the + + align:start position:0% +providing a one-stop dot to make the + + + align:start position:0% +providing a one-stop dot to make the +data accessible and usable to teachers. + + align:start position:0% +data accessible and usable to teachers. + + + align:start position:0% +data accessible and usable to teachers. +Although really a lot of what it was + + align:start position:0% +Although really a lot of what it was + + + align:start position:0% +Although really a lot of what it was +doing was making the data accessible and + + align:start position:0% +doing was making the data accessible and + + + align:start position:0% +doing was making the data accessible and +usable to third parties which might then + + align:start position:0% +usable to third parties which might then + + + align:start position:0% +usable to third parties which might then +benefit teachers. Schools and districts + + align:start position:0% +benefit teachers. Schools and districts + + + align:start position:0% +benefit teachers. Schools and districts +collect a lot of data but it's all over + + align:start position:0% +collect a lot of data but it's all over + + + align:start position:0% +collect a lot of data but it's all over +the place. Strainberger says it's it's + + align:start position:0% +the place. Strainberger says it's it's + + + align:start position:0% +the place. Strainberger says it's it's +different systems are disconnected and + + align:start position:0% +different systems are disconnected and + + + align:start position:0% +different systems are disconnected and +so as a result this data is not usable. + + align:start position:0% +so as a result this data is not usable. + + + align:start position:0% +so as a result this data is not usable. +Can anybody think of of uh all right so + + align:start position:0% +Can anybody think of of uh all right so + + + align:start position:0% +Can anybody think of of uh all right so +that that was a very serious problem + + align:start position:0% +that that was a very serious problem + + + align:start position:0% +that that was a very serious problem +like schools are collecting tons of data + + align:start position:0% +like schools are collecting tons of data + + + align:start position:0% +like schools are collecting tons of data +it's fragmented across all these + + align:start position:0% +it's fragmented across all these + + + align:start position:0% +it's fragmented across all these +services all these kinds of things and + + align:start position:0% +services all these kinds of things and + + + align:start position:0% +services all these kinds of things and +so you know a sense there's like + + align:start position:0% +so you know a sense there's like + + + align:start position:0% +so you know a sense there's like +constant ongoing privacy like either + + align:start position:0% +constant ongoing privacy like either + + + align:start position:0% +constant ongoing privacy like either +privacy risk privacy violations and um + + align:start position:0% +privacy risk privacy violations and um + + + align:start position:0% +privacy risk privacy violations and um +not sensible ways to manage them. That's + + align:start position:0% +not sensible ways to manage them. That's + + + align:start position:0% +not sensible ways to manage them. That's +the problem in Bloom's trying to solve. + + align:start position:0% +the problem in Bloom's trying to solve. + + + align:start position:0% +the problem in Bloom's trying to solve. +Can anybody think of around 2013 like + + align:start position:0% +Can anybody think of around 2013 like + + + align:start position:0% +Can anybody think of around 2013 like +major things that are happening in the + + align:start position:0% +major things that are happening in the + + + align:start position:0% +major things that are happening in the +United States related to uh people's + + align:start position:0% +United States related to uh people's + + + align:start position:0% +United States related to uh people's +perception of their data and + + align:start position:0% +perception of their data and + + + align:start position:0% +perception of their data and +security? You all are a little young for + + align:start position:0% +security? You all are a little young for + + + align:start position:0% +security? You all are a little young for +this now. Target target I think is not + + align:start position:0% +this now. Target target I think is not + + + align:start position:0% +this now. Target target I think is not +that far away from that. So we start + + align:start position:0% +that far away from that. So we start + + + align:start position:0% +that far away from that. So we start +seeing some of the like major data + + align:start position:0% +seeing some of the like major data + + + align:start position:0% +seeing some of the like major data +security breaches. Cambridge Analytica + + align:start position:0% +security breaches. Cambridge Analytica + + + align:start position:0% +security breaches. Cambridge Analytica +uh I think um I think Cambridge + + align:start position:0% +uh I think um I think Cambridge + + + align:start position:0% +uh I think um I think Cambridge +Analytica is a little bit afterwards + + align:start position:0% +Analytica is a little bit afterwards + + + align:start position:0% +Analytica is a little bit afterwards +because that is around the 2016 + + align:start position:0% +because that is around the 2016 + + + align:start position:0% +because that is around the 2016 +election. Yeah. Snowden. Um, this is the + + align:start position:0% +election. Yeah. Snowden. Um, this is the + + + align:start position:0% +election. Yeah. Snowden. Um, this is the +sort of Edward the Edward Snowden era of + + align:start position:0% +sort of Edward the Edward Snowden era of + + + align:start position:0% +sort of Edward the Edward Snowden era of +uh of of rec recognizing the federal + + align:start position:0% +uh of of rec recognizing the federal + + + align:start position:0% +uh of of rec recognizing the federal +government is collecting much more data + + align:start position:0% +government is collecting much more data + + + align:start position:0% +government is collecting much more data +about people um than was previously + + align:start position:0% +about people um than was previously + + + align:start position:0% +about people um than was previously +thought. So, so in 2013, first of all, + + align:start position:0% +thought. So, so in 2013, first of all, + + + align:start position:0% +thought. So, so in 2013, first of all, +people are far less accustomed to + + align:start position:0% +people are far less accustomed to + + + align:start position:0% +people are far less accustomed to +surveillance than you all described + + align:start position:0% +surveillance than you all described + + + align:start position:0% +surveillance than you all described +yourself as accustomed to surveillance. + + align:start position:0% +yourself as accustomed to surveillance. + + + align:start position:0% +yourself as accustomed to surveillance. +Um, and there just been this major + + align:start position:0% +Um, and there just been this major + + + align:start position:0% +Um, and there just been this major +national revelation. Sort of an + + align:start position:0% +national revelation. Sort of an + + + align:start position:0% +national revelation. Sort of an +interesting thing about the inloom story + + align:start position:0% +interesting thing about the inloom story + + + align:start position:0% +interesting thing about the inloom story +is so eventually what happens is there + + align:start position:0% +is so eventually what happens is there + + + align:start position:0% +is so eventually what happens is there +were sort of 11 states that signed on + + align:start position:0% +were sort of 11 states that signed on + + + align:start position:0% +were sort of 11 states that signed on +initially and the hope was is that like + + align:start position:0% +initially and the hope was is that like + + + align:start position:0% +initially and the hope was is that like +then 13 and 14 and 18 and 20 that + + align:start position:0% +then 13 and 14 and 18 and 20 that + + + align:start position:0% +then 13 and 14 and 18 and 20 that +eventually lots and lots of states would + + align:start position:0% +eventually lots and lots of states would + + + align:start position:0% +eventually lots and lots of states would +come on almost immediately states + + align:start position:0% +come on almost immediately states + + + align:start position:0% +come on almost immediately states +started withdrawing from it. um in + + align:start position:0% +started withdrawing from it. um in + + + align:start position:0% +started withdrawing from it. um in +particular over uh in part because of + + align:start position:0% +particular over uh in part because of + + + align:start position:0% +particular over uh in part because of +the concentrated objection from local + + align:start position:0% +the concentrated objection from local + + + align:start position:0% +the concentrated objection from local +advocates uh lo local advocacy groups + + align:start position:0% +advocates uh lo local advocacy groups + + + align:start position:0% +advocates uh lo local advocacy groups +including um like student privacy groups + + align:start position:0% +including um like student privacy groups + + + align:start position:0% +including um like student privacy groups +that were just formed around this time. + + align:start position:0% +that were just formed around this time. + + + align:start position:0% +that were just formed around this time. +New York was like one of the lead ones. + + align:start position:0% +New York was like one of the lead ones. + + + align:start position:0% +New York was like one of the lead ones. +It was one of the last ones to fall out + + align:start position:0% +It was one of the last ones to fall out + + + align:start position:0% +It was one of the last ones to fall out +but it also had one of the most sort of + + align:start position:0% +but it also had one of the most sort of + + + align:start position:0% +but it also had one of the most sort of +viciferous determined um community of + + align:start position:0% +viciferous determined um community of + + + align:start position:0% +viciferous determined um community of +student privacy advocates um opting you + + align:start position:0% +student privacy advocates um opting you + + + align:start position:0% +student privacy advocates um opting you +know. So um state started p like one of + + align:start position:0% +know. So um state started p like one of + + + align:start position:0% +know. So um state started p like one of +the one of the main um outcomes of + + align:start position:0% +the one of the main um outcomes of + + + align:start position:0% +the one of the main um outcomes of +inloom was not its existence actually + + align:start position:0% +inloom was not its existence actually + + + align:start position:0% +inloom was not its existence actually +but like a bunch of state laws about + + align:start position:0% +but like a bunch of state laws about + + + align:start position:0% +but like a bunch of state laws about +student privacy in part that would make + + align:start position:0% +student privacy in part that would make + + + align:start position:0% +student privacy in part that would make +it more difficult for things like inloom + + align:start position:0% +it more difficult for things like inloom + + + align:start position:0% +it more difficult for things like inloom +to exist. um a a a common problem that + + align:start position:0% +to exist. um a a a common problem that + + + align:start position:0% +to exist. um a a a common problem that +shows up when trying to fix data and + + align:start position:0% +shows up when trying to fix data and + + + align:start position:0% +shows up when trying to fix data and +privacy problems and I'm giving you an + + align:start position:0% +privacy problems and I'm giving you an + + + align:start position:0% +privacy problems and I'm giving you an +example from schools but this is a thing + + align:start position:0% +example from schools but this is a thing + + + align:start position:0% +example from schools but this is a thing +that you could find in almost any um uh + + align:start position:0% +that you could find in almost any um uh + + + align:start position:0% +that you could find in almost any um uh +in any other sector like the the + + align:start position:0% +in any other sector like the the + + + align:start position:0% +in any other sector like the the +pre-inloom counterfactual is really + + align:start position:0% +pre-inloom counterfactual is really + + + align:start position:0% +pre-inloom counterfactual is really +really bad. It is not a good system to + + align:start position:0% +really bad. It is not a good system to + + + align:start position:0% +really bad. It is not a good system to +like force kids to go to public schools + + align:start position:0% +like force kids to go to public schools + + + align:start position:0% +like force kids to go to public schools +and then have a bunch of thirdparty + + align:start position:0% +and then have a bunch of thirdparty + + + align:start position:0% +and then have a bunch of thirdparty +for-profit companies get their data from + + align:start position:0% +for-profit companies get their data from + + + align:start position:0% +for-profit companies get their data from +schools. The schools are bad at + + align:start position:0% +schools. The schools are bad at + + + align:start position:0% +schools. The schools are bad at +managing. they don't have the expertise, + + align:start position:0% +managing. they don't have the expertise, + + + align:start position:0% +managing. they don't have the expertise, +all these kinds of things. + + align:start position:0% +all these kinds of things. + + + align:start position:0% +all these kinds of things. +Um however by trying to fix the problem + + align:start position:0% +Um however by trying to fix the problem + + + align:start position:0% +Um however by trying to fix the problem +in bloom draws attention to the problem + + align:start position:0% +in bloom draws attention to the problem + + + align:start position:0% +in bloom draws attention to the problem +you know like man this data is such a + + align:start position:0% +you know like man this data is such a + + + align:start position:0% +you know like man this data is such a +mess and we're going to collect it all + + align:start position:0% +mess and we're going to collect it all + + + align:start position:0% +mess and we're going to collect it all +like in some like there are all kinds of + + align:start position:0% +like in some like there are all kinds of + + + align:start position:0% +like in some like there are all kinds of +circumstances in which you like if you + + align:start position:0% +circumstances in which you like if you + + + align:start position:0% +circumstances in which you like if you +draw attention to data and experiments + + align:start position:0% +draw attention to data and experiments + + + align:start position:0% +draw attention to data and experiments +even if the sort of like the the status + + align:start position:0% +even if the sort of like the the status + + + align:start position:0% +even if the sort of like the the status +quo is really terrible people are not + + align:start position:0% +quo is really terrible people are not + + + align:start position:0% +quo is really terrible people are not +going to be enthusiastic about the fix + + align:start position:0% +going to be enthusiastic about the fix + + + align:start position:0% +going to be enthusiastic about the fix +because nobody thinks dayto-day about + + align:start position:0% +because nobody thinks dayto-day about + + + align:start position:0% +because nobody thinks dayto-day about +the status quo but they think really + + align:start position:0% +the status quo but they think really + + + align:start position:0% +the status quo but they think really +intensely about this crazy inloom thing + + align:start position:0% +intensely about this crazy inloom thing + + + align:start position:0% +intensely about this crazy inloom thing +that you're doing. Um, does that does + + align:start position:0% +that you're doing. Um, does that does + + + align:start position:0% +that you're doing. Um, does that does +that as an idea make sense? Like this + + align:start position:0% +that as an idea make sense? Like this + + + align:start position:0% +that as an idea make sense? Like this +essentially, you know, there's all kind + + align:start position:0% +essentially, you know, there's all kind + + + align:start position:0% +essentially, you know, there's all kind +like other studies come out along the + + align:start position:0% +like other studies come out along the + + + align:start position:0% +like other studies come out along the +lines of um, hey, we've come up with + + align:start position:0% +lines of um, hey, we've come up with + + + align:start position:0% +lines of um, hey, we've come up with +this really good way to protect your + + align:start position:0% +this really good way to protect your + + + align:start position:0% +this really good way to protect your +privacy. Will you opt into it? People + + align:start position:0% +privacy. Will you opt into it? People + + + align:start position:0% +privacy. Will you opt into it? People +will be like, whoa. Um, why would why + + align:start position:0% +will be like, whoa. Um, why would why + + + align:start position:0% +will be like, whoa. Um, why would why +would I have to protect my privacy? Why + + align:start position:0% +would I have to protect my privacy? Why + + + align:start position:0% +would I have to protect my privacy? Why +would I opt into this thing? It's + + align:start position:0% +would I opt into this thing? It's + + + align:start position:0% +would I opt into this thing? It's +dangerous. Like, they would prefer the + + align:start position:0% +dangerous. Like, they would prefer the + + + align:start position:0% +dangerous. Like, they would prefer the +status quo where their privacy is not + + align:start position:0% +status quo where their privacy is not + + + align:start position:0% +status quo where their privacy is not +protected towards this thing in which + + align:start position:0% +protected towards this thing in which + + + align:start position:0% +protected towards this thing in which +you've raised their concerns about. Um + + align:start position:0% + + + + align:start position:0% + +uh so this is an organization that just + + align:start position:0% +uh so this is an organization that just + + + align:start position:0% +uh so this is an organization that just +came into life um last week. Uh it's + + align:start position:0% +came into life um last week. Uh it's + + + align:start position:0% +came into life um last week. Uh it's +called Safe Insights. Um it was funded + + align:start position:0% +called Safe Insights. Um it was funded + + + align:start position:0% +called Safe Insights. Um it was funded +by $90 million from the National Science + + align:start position:0% +by $90 million from the National Science + + + align:start position:0% +by $90 million from the National Science +Foundation. Uh it is out of Rice + + align:start position:0% +Foundation. Uh it is out of Rice + + + align:start position:0% +Foundation. Uh it is out of Rice +University out of the same people that + + align:start position:0% +University out of the same people that + + + align:start position:0% +University out of the same people that +developed Open Stacks. We talked about + + align:start position:0% +developed Open Stacks. We talked about + + + align:start position:0% +developed Open Stacks. We talked about +Open Stacks the other day. They're the + + align:start position:0% +Open Stacks the other day. They're the + + + align:start position:0% +Open Stacks the other day. They're the +company that creates um uh free and open + + align:start position:0% +company that creates um uh free and open + + + align:start position:0% +company that creates um uh free and open +source textbooks for community college + + align:start position:0% +source textbooks for community college + + + align:start position:0% +source textbooks for community college +folks. Um they + + align:start position:0% +folks. Um they + + + align:start position:0% +folks. Um they +have we have enough time. I'll show you + + align:start position:0% +have we have enough time. I'll show you + + + align:start position:0% +have we have enough time. I'll show you +the one. + + align:start position:0% +the one. + + + align:start position:0% +the one. +Uh, let's see if we can find the the + + align:start position:0% +Uh, let's see if we can find the the + + + align:start position:0% +Uh, let's see if we can find the the +Safe Insights welcome + + align:start position:0% + + + + align:start position:0% + +video. As a longtime college instructor, + + align:start position:0% +video. As a longtime college instructor, + + + align:start position:0% +video. As a longtime college instructor, +every day of my career has been + + align:start position:0% +every day of my career has been + + + align:start position:0% +every day of my career has been +dedicated to helping my students reach + + align:start position:0% +dedicated to helping my students reach + + + align:start position:0% +dedicated to helping my students reach +their academic goals. I'm always looking + + align:start position:0% +their academic goals. I'm always looking + + + align:start position:0% +their academic goals. I'm always looking +to better support their learning in ways + + align:start position:0% +to better support their learning in ways + + + align:start position:0% +to better support their learning in ways +that are proven to work best. There's so + + align:start position:0% +that are proven to work best. There's so + + + align:start position:0% +that are proven to work best. There's so +much we have to understand about how + + align:start position:0% +much we have to understand about how + + + align:start position:0% +much we have to understand about how +people learn. Every mind is beautiful + + align:start position:0% +people learn. Every mind is beautiful + + + align:start position:0% +people learn. Every mind is beautiful +and special. That means we all learn in + + align:start position:0% +and special. That means we all learn in + + + align:start position:0% +and special. That means we all learn in +different ways. We all have our own + + align:start position:0% +different ways. We all have our own + + + align:start position:0% +different ways. We all have our own +definitions of what success looks like. + + align:start position:0% +definitions of what success looks like. + + + align:start position:0% +definitions of what success looks like. +If researchers are able to uncover new + + align:start position:0% +If researchers are able to uncover new + + + align:start position:0% +If researchers are able to uncover new +and better ways of learning, that will + + align:start position:0% +and better ways of learning, that will + + + align:start position:0% +and better ways of learning, that will +have a profound impact on how educators + + align:start position:0% +have a profound impact on how educators + + + align:start position:0% +have a profound impact on how educators +approach teaching. To do this, we need a + + align:start position:0% +approach teaching. To do this, we need a + + + align:start position:0% +approach teaching. To do this, we need a +way to securely connect with a wide + + align:start position:0% +way to securely connect with a wide + + + align:start position:0% +way to securely connect with a wide +variety of students as they study over + + align:start position:0% +variety of students as they study over + + + align:start position:0% +variety of students as they study over +time in real + + align:start position:0% +time in real + + + align:start position:0% +time in real +classrooms. Student needs are changing. + + align:start position:0% +classrooms. Student needs are changing. + + + align:start position:0% +classrooms. Student needs are changing. +With more learning happening online, it + + align:start position:0% +With more learning happening online, it + + + align:start position:0% +With more learning happening online, it +gets harder and harder to understand + + align:start position:0% +gets harder and harder to understand + + + align:start position:0% +gets harder and harder to understand +what each student needs and how best to + + align:start position:0% +what each student needs and how best to + + + align:start position:0% +what each student needs and how best to +help them at the moment when they're + + align:start position:0% +help them at the moment when they're + + + align:start position:0% +help them at the moment when they're +really needed the most. Education + + align:start position:0% +really needed the most. Education + + + align:start position:0% +really needed the most. Education +research is essential for advancing + + align:start position:0% +research is essential for advancing + + + align:start position:0% +research is essential for advancing +teaching and learning so that every + + align:start position:0% +teaching and learning so that every + + + align:start position:0% +teaching and learning so that every +student can succeed. We know that + + align:start position:0% +student can succeed. We know that + + + align:start position:0% +student can succeed. We know that +research informed teaching works, but + + align:start position:0% +research informed teaching works, but + + + align:start position:0% +research informed teaching works, but +it's still too hard to conduct + + align:start position:0% +it's still too hard to conduct + + + align:start position:0% +it's still too hard to conduct +large-scale reliable research and then + + align:start position:0% +large-scale reliable research and then + + + align:start position:0% +large-scale reliable research and then +apply the results in the classroom. Safe + + align:start position:0% +apply the results in the classroom. Safe + + + align:start position:0% +apply the results in the classroom. Safe +Insights brings together learning + + align:start position:0% +Insights brings together learning + + + align:start position:0% +Insights brings together learning +researchers, educators, schools, and + + align:start position:0% +researchers, educators, schools, and + + + align:start position:0% +researchers, educators, schools, and +colleges in a secure environment to get + + align:start position:0% +colleges in a secure environment to get + + + align:start position:0% +colleges in a secure environment to get +the answers we need while strongly + + align:start position:0% +the answers we need while strongly + + + align:start position:0% +the answers we need while strongly +protecting students and their interests. + + align:start position:0% +protecting students and their interests. + + + align:start position:0% +protecting students and their interests. +Every student deserves the chance to + + align:start position:0% +Every student deserves the chance to + + + align:start position:0% +Every student deserves the chance to +succeed in the classroom and beyond. + + align:start position:0% +succeed in the classroom and beyond. + + + align:start position:0% +succeed in the classroom and beyond. +Safe Insights will give researchers, + + align:start position:0% +Safe Insights will give researchers, + + + align:start position:0% +Safe Insights will give researchers, +educators, and students what they need + + align:start position:0% +educators, and students what they need + + + align:start position:0% +educators, and students what they need +to take learning to the next level. And + + align:start position:0% +to take learning to the next level. And + + + align:start position:0% +to take learning to the next level. And +as educators, we will benefit from + + align:start position:0% +as educators, we will benefit from + + + align:start position:0% +as educators, we will benefit from +better research from Safe Insights to + + align:start position:0% +better research from Safe Insights to + + + align:start position:0% +better research from Safe Insights to +effectively help all our students. + + align:start position:0% +effectively help all our students. + + + align:start position:0% +effectively help all our students. +[Music] + + align:start position:0% + + + + align:start position:0% + +Great. + + align:start position:0% +Great. + + + align:start position:0% +Great. +It it is it is a little dramatic for for + + align:start position:0% +It it is it is a little dramatic for for + + + align:start position:0% +It it is it is a little dramatic for for +like a + + align:start position:0% +like a + + + align:start position:0% +like a +database but I I mean I don't know I + + align:start position:0% +database but I I mean I don't know I + + + align:start position:0% +database but I I mean I don't know I +like database. Okay. Um what are what + + align:start position:0% +like database. Okay. Um what are what + + + align:start position:0% +like database. Okay. Um what are what +are what are your first instincts having + + align:start position:0% +are what are your first instincts having + + + align:start position:0% +are what are your first instincts having +spent a whole bunch of time um uh having + + align:start position:0% +spent a whole bunch of time um uh having + + + align:start position:0% +spent a whole bunch of time um uh having +spent you know an hour and 20 minutes + + align:start position:0% +spent you know an hour and 20 minutes + + + align:start position:0% +spent you know an hour and 20 minutes +talking about the toxic power of data + + align:start position:0% +talking about the toxic power of data + + + align:start position:0% +talking about the toxic power of data +and experiments and how do you think + + align:start position:0% +and experiments and how do you think + + + align:start position:0% +and experiments and how do you think +like a typical American parent or + + align:start position:0% +like a typical American parent or + + + align:start position:0% +like a typical American parent or +typical American college student would + + align:start position:0% +typical American college student would + + + align:start position:0% +typical American college student would +react to that video? + + align:start position:0% +react to that video? + + + align:start position:0% +react to that video? +I think it would change like based on + + align:start position:0% +I think it would change like based on + + + align:start position:0% +I think it would change like based on +different generations because I think + + align:start position:0% +different generations because I think + + + align:start position:0% +different generations because I think +our generation who is now like using Tik + + align:start position:0% +our generation who is now like using Tik + + + align:start position:0% +our generation who is now like using Tik +Tok when we openly know like they use + + align:start position:0% +Tok when we openly know like they use + + + align:start position:0% +Tok when we openly know like they use +our data and like listen to us is + + align:start position:0% +our data and like listen to us is + + + align:start position:0% +our data and like listen to us is +completely different from like our + + align:start position:0% +completely different from like our + + + align:start position:0% +completely different from like our +parents who are like oh my god like + + align:start position:0% +parents who are like oh my god like + + + align:start position:0% +parents who are like oh my god like +don't have a profile picture don't this + + align:start position:0% +don't have a profile picture don't this + + + align:start position:0% +don't have a profile picture don't this +and that. So I think our generation will + + align:start position:0% +and that. So I think our generation will + + + align:start position:0% +and that. So I think our generation will +be way more accepting of this and I + + align:start position:0% +be way more accepting of this and I + + + align:start position:0% +be way more accepting of this and I +think as like in like 10 20 years down + + align:start position:0% +think as like in like 10 20 years down + + + align:start position:0% +think as like in like 10 20 years down +the line I think people and parents will + + align:start position:0% +the line I think people and parents will + + + align:start position:0% +the line I think people and parents will +be so accustomed to their children's + + align:start position:0% +be so accustomed to their children's + + + align:start position:0% +be so accustomed to their children's +data just being like whatever good. So + + align:start position:0% +data just being like whatever good. So + + + align:start position:0% +data just being like whatever good. So +you know so conceivably even you know in + + align:start position:0% +you know so conceivably even you know in + + + align:start position:0% +you know so conceivably even you know in +bloom launched today might have had a + + align:start position:0% +bloom launched today might have had a + + + align:start position:0% +bloom launched today might have had a +very different experience than in Bloom + + align:start position:0% +very different experience than in Bloom + + + align:start position:0% +very different experience than in Bloom +launched in 2013 not because of anything + + align:start position:0% +launched in 2013 not because of anything + + + align:start position:0% +launched in 2013 not because of anything +different that they did but because of + + align:start position:0% +different that they did but because of + + + align:start position:0% +different that they did but because of +the context that they operate in. I + + align:start position:0% +the context that they operate in. I + + + align:start position:0% +the context that they operate in. I +think there's evidence of that. I was + + align:start position:0% +think there's evidence of that. I was + + + align:start position:0% +think there's evidence of that. I was +just talking to somebody who runs a a + + align:start position:0% +just talking to somebody who runs a a + + + align:start position:0% +just talking to somebody who runs a a +video repository for uh child + + align:start position:0% +video repository for uh child + + + align:start position:0% +video repository for uh child +development studies. Um and one of their + + align:start position:0% +development studies. Um and one of their + + + align:start position:0% +development studies. Um and one of their +conditions is that uh the the videos can + + align:start position:0% +conditions is that uh the the videos can + + + align:start position:0% +conditions is that uh the the videos can +only be used for non-commercial + + align:start position:0% +only be used for non-commercial + + + align:start position:0% +only be used for non-commercial +purposes. And I was like, how you know + + align:start position:0% +purposes. And I was like, how you know + + + align:start position:0% +purposes. And I was like, how you know +why did you do that? And we're like, + + align:start position:0% +why did you do that? And we're like, + + + align:start position:0% +why did you do that? And we're like, +well, we made it 10 years ago and people + + align:start position:0% +well, we made it 10 years ago and people + + + align:start position:0% +well, we made it 10 years ago and people +were really worried about stuff and that + + align:start position:0% +were really worried about stuff and that + + + align:start position:0% +were really worried about stuff and that +sort of helped calm them down. But if we + + align:start position:0% +sort of helped calm them down. But if we + + + align:start position:0% +sort of helped calm them down. But if we +did it again today, I you know, I don't + + align:start position:0% +did it again today, I you know, I don't + + + align:start position:0% +did it again today, I you know, I don't +think the same level of concern exists, + + align:start position:0% +think the same level of concern exists, + + + align:start position:0% +think the same level of concern exists, +not only among people generally, but + + align:start position:0% +not only among people generally, but + + + align:start position:0% +not only among people generally, but +like institutionally as well. What do + + align:start position:0% +like institutionally as well. What do + + + align:start position:0% +like institutionally as well. What do +you say, Courtney? Um I think it was + + align:start position:0% +you say, Courtney? Um I think it was + + + align:start position:0% +you say, Courtney? Um I think it was +really smart that they've attached + + align:start position:0% +really smart that they've attached + + + align:start position:0% +really smart that they've attached +themselves to Rice because I think + + align:start position:0% +themselves to Rice because I think + + + align:start position:0% +themselves to Rice because I think +especially like our parents generation + + align:start position:0% +especially like our parents generation + + + align:start position:0% +especially like our parents generation +maybe less so now there's a lot of + + align:start position:0% +maybe less so now there's a lot of + + + align:start position:0% +maybe less so now there's a lot of +goodwill given to universities and so + + align:start position:0% +goodwill given to universities and so + + + align:start position:0% +goodwill given to universities and so +like if in Bloom came out today and it + + align:start position:0% +like if in Bloom came out today and it + + + align:start position:0% +like if in Bloom came out today and it +was like oh in partnership with MIT I do + + align:start position:0% +was like oh in partnership with MIT I do + + + align:start position:0% +was like oh in partnership with MIT I do +think people would have received it a + + align:start position:0% +think people would have received it a + + + align:start position:0% +think people would have received it a +lot differently and like people have a + + align:start position:0% +lot differently and like people have a + + + align:start position:0% +lot differently and like people have a +lot of trust that like oh it's connected + + align:start position:0% +lot of trust that like oh it's connected + + + align:start position:0% +lot of trust that like oh it's connected +to Rice how bad could it really be? + + align:start position:0% +to Rice how bad could it really be? + + + align:start position:0% +to Rice how bad could it really be? +Yeah. And you know I would say I would + + align:start position:0% +Yeah. And you know I would say I would + + + align:start position:0% +Yeah. And you know I would say I would +say the the Gates Foundation related + + align:start position:0% +say the the Gates Foundation related + + + align:start position:0% +say the the Gates Foundation related +conspiracy theories were not quite as + + align:start position:0% +conspiracy theories were not quite as + + + align:start position:0% +conspiracy theories were not quite as +strong in 2013. Um but like the Gates + + align:start position:0% +strong in 2013. Um but like the Gates + + + align:start position:0% +strong in 2013. Um but like the Gates +Foundation is not a trusted organization + + align:start position:0% +Foundation is not a trusted organization + + + align:start position:0% +Foundation is not a trusted organization +in the same way that I think uh yeah + + align:start position:0% +in the same way that I think uh yeah + + + align:start position:0% +in the same way that I think uh yeah +Rice University universities in general + + align:start position:0% +Rice University universities in general + + + align:start position:0% +Rice University universities in general +like state schools um are still some of + + align:start position:0% +like state schools um are still some of + + + align:start position:0% +like state schools um are still some of +the most trusted institutions in + + align:start position:0% +the most trusted institutions in + + + align:start position:0% +the most trusted institutions in +society. + + align:start position:0% +society. + + + align:start position:0% +society. +Um I think like maybe actually a little + + align:start position:0% +Um I think like maybe actually a little + + + align:start position:0% +Um I think like maybe actually a little +um connected to that trustworthiness I + + align:start position:0% +um connected to that trustworthiness I + + + align:start position:0% +um connected to that trustworthiness I +think is that um if you say like oh my + + align:start position:0% +think is that um if you say like oh my + + + align:start position:0% +think is that um if you say like oh my +god look all your data is in one place + + align:start position:0% +god look all your data is in one place + + + align:start position:0% +god look all your data is in one place +like to someone who finds like education + + align:start position:0% +like to someone who finds like education + + + align:start position:0% +like to someone who finds like education +research and things like that really + + align:start position:0% +research and things like that really + + + align:start position:0% +research and things like that really +important and is like much more aware of + + align:start position:0% +important and is like much more aware of + + + align:start position:0% +important and is like much more aware of +um like how that might help that might + + align:start position:0% +um like how that might help that might + + + align:start position:0% +um like how that might help that might +sound good but I think to the average + + align:start position:0% +sound good but I think to the average + + + align:start position:0% +sound good but I think to the average +person first and foremost what's going + + align:start position:0% +person first and foremost what's going + + + align:start position:0% +person first and foremost what's going +to pop out when you tell tell them, "Oh, + + align:start position:0% +to pop out when you tell tell them, "Oh, + + + align:start position:0% +to pop out when you tell tell them, "Oh, +we have everything in one place and we + + align:start position:0% +we have everything in one place and we + + + align:start position:0% +we have everything in one place and we +promise it's safe." It's like one, like + + align:start position:0% +promise it's safe." It's like one, like + + + align:start position:0% +promise it's safe." It's like one, like +you're not giving me any information + + align:start position:0% +you're not giving me any information + + + align:start position:0% +you're not giving me any information +about how you're keeping the data safe. + + align:start position:0% +about how you're keeping the data safe. + + + align:start position:0% +about how you're keeping the data safe. +And two, like I think like it's always + + align:start position:0% +And two, like I think like it's always + + + align:start position:0% +And two, like I think like it's always +been like set up like don't put all your + + align:start position:0% +been like set up like don't put all your + + + align:start position:0% +been like set up like don't put all your +data in one place. So it's like well how + + align:start position:0% +data in one place. So it's like well how + + + align:start position:0% +data in one place. So it's like well how +why are you like saying this is a good + + align:start position:0% +why are you like saying this is a good + + + align:start position:0% +why are you like saying this is a good +thing because then this means that like + + align:start position:0% +thing because then this means that like + + + align:start position:0% +thing because then this means that like +someone can have all my data as opposed + + align:start position:0% +someone can have all my data as opposed + + + align:start position:0% +someone can have all my data as opposed +to like let's say if it is split up even + + align:start position:0% +to like let's say if it is split up even + + + align:start position:0% +to like let's say if it is split up even +if it's there I can be like okay like my + + align:start position:0% +if it's there I can be like okay like my + + + align:start position:0% +if it's there I can be like okay like my +teacher might have this piece of data on + + align:start position:0% +teacher might have this piece of data on + + + align:start position:0% +teacher might have this piece of data on +me but they might not have this other + + align:start position:0% +me but they might not have this other + + + align:start position:0% +me but they might not have this other +piece of data and actually probably the + + align:start position:0% +piece of data and actually probably the + + + align:start position:0% +piece of data and actually probably the +main technical I mean there'll probably + + align:start position:0% +main technical I mean there'll probably + + + align:start position:0% +main technical I mean there'll probably +a bunch and we don't know exactly where + + align:start position:0% +a bunch and we don't know exactly where + + + align:start position:0% +a bunch and we don't know exactly where +they'll be then but one of the one of + + align:start position:0% +they'll be then but one of the one of + + + align:start position:0% +they'll be then but one of the one of +the earliest proposed technical + + align:start position:0% +the earliest proposed technical + + + align:start position:0% +the earliest proposed technical +innovations of safe insights is not to + + align:start position:0% +innovations of safe insights is not to + + + align:start position:0% +innovations of safe insights is not to +bring all the data together. Um so it so + + align:start position:0% +bring all the data together. Um so it so + + + align:start position:0% +bring all the data together. Um so it so +it doesn't propose that all of it gets + + align:start position:0% +it doesn't propose that all of it gets + + + align:start position:0% +it doesn't propose that all of it gets +collected. One of the main things that + + align:start position:0% +collected. One of the main things that + + + align:start position:0% +collected. One of the main things that +they want to be able to do um is to be + + align:start position:0% +they want to be able to do um is to be + + + align:start position:0% +they want to be able to do um is to be +able to conduct research queries across + + align:start position:0% +able to conduct research queries across + + + align:start position:0% +able to conduct research queries across +data without having people have to + + align:start position:0% +data without having people have to + + + align:start position:0% +data without having people have to +directly access those data. So there's a + + align:start position:0% +directly access those data. So there's a + + + align:start position:0% +directly access those data. So there's a +there's a whole field of study called + + align:start position:0% +there's a whole field of study called + + + align:start position:0% +there's a whole field of study called +things like differential privacy and + + align:start position:0% +things like differential privacy and + + + align:start position:0% +things like differential privacy and +stuff like that which basically says um + + align:start position:0% +stuff like that which basically says um + + + align:start position:0% +stuff like that which basically says um +how do I how do I tell you the kinds of + + align:start position:0% +how do I how do I tell you the kinds of + + + align:start position:0% +how do I how do I tell you the kinds of +things that are in a data set let you + + align:start position:0% +things that are in a data set let you + + + align:start position:0% +things that are in a data set let you +run a query over that data set um but + + align:start position:0% +run a query over that data set um but + + + align:start position:0% +run a query over that data set um but +never actually encounter that data set + + align:start position:0% +never actually encounter that data set + + + align:start position:0% +never actually encounter that data set +and and in this kind of environment + + align:start position:0% +and and in this kind of environment + + + align:start position:0% +and and in this kind of environment +there might be how would you run a query + + align:start position:0% +there might be how would you run a query + + + align:start position:0% +there might be how would you run a query +that connects people's you know student + + align:start position:0% +that connects people's you know student + + + align:start position:0% +that connects people's you know student +behavior in a learning platform with + + align:start position:0% +behavior in a learning platform with + + + align:start position:0% +behavior in a learning platform with +their registar information with their + + align:start position:0% +their registar information with their + + + align:start position:0% +their registar information with their +state test scores without having to like + + align:start position:0% +state test scores without having to like + + + align:start position:0% +state test scores without having to like +make one giant data set out of all those + + align:start position:0% +make one giant data set out of all those + + + align:start position:0% +make one giant data set out of all those +things, but instead to like, you know, + + align:start position:0% +things, but instead to like, you know, + + + align:start position:0% +things, but instead to like, you know, +have the query just, you know, run over + + align:start position:0% +have the query just, you know, run over + + + align:start position:0% +have the query just, you know, run over +the data it needs, you know, still like + + align:start position:0% +the data it needs, you know, still like + + + align:start position:0% +the data it needs, you know, still like +have the main the people who own that + + align:start position:0% +have the main the people who own that + + + align:start position:0% +have the main the people who own that +data still hold on to that data, but + + align:start position:0% +data still hold on to that data, but + + + align:start position:0% +data still hold on to that data, but +have the results of that query go to + + align:start position:0% +have the results of that query go to + + + align:start position:0% +have the results of that query go to +technology developers, um, researchers, + + align:start position:0% +technology developers, um, researchers, + + + align:start position:0% +technology developers, um, researchers, +things like that without having to have + + align:start position:0% +things like that without having to have + + + align:start position:0% +things like that without having to have +them collect all of the data. So in some + + align:start position:0% +them collect all of the data. So in some + + + align:start position:0% +them collect all of the data. So in some +ways it's like explicitly trying to be + + align:start position:0% +ways it's like explicitly trying to be + + + align:start position:0% +ways it's like explicitly trying to be +the opposite of inloom like don't bring + + align:start position:0% +the opposite of inloom like don't bring + + + align:start position:0% +the opposite of inloom like don't bring +all the data in one place like try to + + align:start position:0% +all the data in one place like try to + + + align:start position:0% +all the data in one place like try to +get the benefits of aggregated data + + align:start position:0% +get the benefits of aggregated data + + + align:start position:0% +get the benefits of aggregated data +without having to share it with either a + + align:start position:0% +without having to share it with either a + + + align:start position:0% +without having to share it with either a +trusted third party or everyone or + + align:start position:0% +trusted third party or everyone or + + + align:start position:0% +trusted third party or everyone or +something like that. + + align:start position:0% +something like that. + + + align:start position:0% +something like that. +I was I was just going to say I feel + + align:start position:0% +I was I was just going to say I feel + + + align:start position:0% +I was I was just going to say I feel +like you kind of answered it like right + + align:start position:0% +like you kind of answered it like right + + + align:start position:0% +like you kind of answered it like right +there with what you were saying, but + + align:start position:0% +there with what you were saying, but + + + align:start position:0% +there with what you were saying, but +like in your opinion, do you think like + + align:start position:0% +like in your opinion, do you think like + + + align:start position:0% +like in your opinion, do you think like +the people who are creating this new um + + align:start position:0% +the people who are creating this new um + + + align:start position:0% +the people who are creating this new um +the safe insights? Do you think they + + align:start position:0% +the safe insights? Do you think they + + + align:start position:0% +the safe insights? Do you think they +like really understood what went wrong + + align:start position:0% +like really understood what went wrong + + + align:start position:0% +like really understood what went wrong +in Inloom? And do you think like + + align:start position:0% +in Inloom? And do you think like + + + align:start position:0% +in Inloom? And do you think like +ultimately does it lead back? Boy, it + + align:start position:0% +ultimately does it lead back? Boy, it + + + align:start position:0% +ultimately does it lead back? Boy, it +sure I mean it sure sounds like it to + + align:start position:0% +sure I mean it sure sounds like it to + + + align:start position:0% +sure I mean it sure sounds like it to +me. Like powerful privacy preserving + + align:start position:0% +me. Like powerful privacy preserving + + + align:start position:0% +me. Like powerful privacy preserving +learning research. Um, so like the very + + align:start position:0% +learning research. Um, so like the very + + + align:start position:0% +learning research. Um, so like the very +first concept they they want to ingrain + + align:start position:0% +first concept they they want to ingrain + + + align:start position:0% +first concept they they want to ingrain +in your head is safe. Um, the second + + align:start position:0% +in your head is safe. Um, the second + + + align:start position:0% +in your head is safe. Um, the second +concept that I think they're doing + + align:start position:0% +concept that I think they're doing + + + align:start position:0% +concept that I think they're doing +rhetorically is leaning into insight + + align:start position:0% +rhetorically is leaning into insight + + + align:start position:0% +rhetorically is leaning into insight +rather than data. Um, so I think if you + + align:start position:0% +rather than data. Um, so I think if you + + + align:start position:0% +rather than data. Um, so I think if you +asked people what Inbloom was, they + + align:start position:0% +asked people what Inbloom was, they + + + align:start position:0% +asked people what Inbloom was, they +would have described it as some kind of + + align:start position:0% +would have described it as some kind of + + + align:start position:0% +would have described it as some kind of +data repository. My hunch um is that the + + align:start position:0% +data repository. My hunch um is that the + + + align:start position:0% +data repository. My hunch um is that the +safe insights people are going to + + align:start position:0% +safe insights people are going to + + + align:start position:0% +safe insights people are going to +describe themselves as an insight + + align:start position:0% +describe themselves as an insight + + + align:start position:0% +describe themselves as an insight +generator. um as a research producer. + + align:start position:0% +generator. um as a research producer. + + + align:start position:0% +generator. um as a research producer. +Now, it's the exact same thing, right? + + align:start position:0% +Now, it's the exact same thing, right? + + + align:start position:0% +Now, it's the exact same thing, right? +Um because in order to get the insights, + + align:start position:0% +Um because in order to get the insights, + + + align:start position:0% +Um because in order to get the insights, +you have to have the data somewhere. And + + align:start position:0% +you have to have the data somewhere. And + + + align:start position:0% +you have to have the data somewhere. And +InBloom, InBloom's purpose was never + + align:start position:0% +InBloom, InBloom's purpose was never + + + align:start position:0% +InBloom, InBloom's purpose was never +just to like hoard data. It was to make + + align:start position:0% +just to like hoard data. It was to make + + + align:start position:0% +just to like hoard data. It was to make +learning better for kids. Um but I think + + align:start position:0% +learning better for kids. Um but I think + + + align:start position:0% +learning better for kids. Um but I think +I think there are I like I guarantee you + + align:start position:0% +I think there are I like I guarantee you + + + align:start position:0% +I think there are I like I guarantee you +that all of the pe many of the people + + align:start position:0% +that all of the pe many of the people + + + align:start position:0% +that all of the pe many of the people +who worked on safe insights um have done + + align:start position:0% +who worked on safe insights um have done + + + align:start position:0% +who worked on safe insights um have done +plenty of studying of what went wrong + + align:start position:0% +plenty of studying of what went wrong + + + align:start position:0% +plenty of studying of what went wrong +with in bloom um and are designing this + + align:start position:0% +with in bloom um and are designing this + + + align:start position:0% +with in bloom um and are designing this +enterprise you know so that it's you + + align:start position:0% +enterprise you know so that it's you + + + align:start position:0% +enterprise you know so that it's you +know it's with a trusted university it's + + align:start position:0% +know it's with a trusted university it's + + + align:start position:0% +know it's with a trusted university it's +founded by the national science + + align:start position:0% +founded by the national science + + + align:start position:0% +founded by the national science +foundation which I assume also has very + + align:start position:0% +foundation which I assume also has very + + + align:start position:0% +foundation which I assume also has very +high trust but like all this language it + + align:start position:0% +high trust but like all this language it + + + align:start position:0% +high trust but like all this language it +it definitely strikes me as like like + + align:start position:0% +it definitely strikes me as like like + + + align:start position:0% +it definitely strikes me as like like +people who read up on the inb bloom case + + align:start position:0% +people who read up on the inb bloom case + + + align:start position:0% +people who read up on the inb bloom case +study and are trying a different tack. + + align:start position:0% +study and are trying a different tack. + + + align:start position:0% +study and are trying a different tack. +I think uh another good thing that they + + align:start position:0% +I think uh another good thing that they + + + align:start position:0% +I think uh another good thing that they +did was associate themselves with a + + align:start position:0% +did was associate themselves with a + + + align:start position:0% +did was associate themselves with a +previous product that was successful + + align:start position:0% +previous product that was successful + + + align:start position:0% +previous product that was successful +which was open stacks which in itself + + align:start position:0% +which was open stacks which in itself + + + align:start position:0% +which was open stacks which in itself +open stacks I mean they are open what is + + align:start position:0% +open stacks I mean they are open what is + + + align:start position:0% +open stacks I mean they are open what is +it open source uh like preuse uh + + align:start position:0% +it open source uh like preuse uh + + + align:start position:0% +it open source uh like preuse uh +textbooks and that in itself has proven + + align:start position:0% +textbooks and that in itself has proven + + + align:start position:0% +textbooks and that in itself has proven +to be like okay we are transparent quite + + align:start position:0% +to be like okay we are transparent quite + + + align:start position:0% +to be like okay we are transparent quite +literally transparent about what we're + + align:start position:0% +literally transparent about what we're + + + align:start position:0% +literally transparent about what we're +doing and we've already provided a + + align:start position:0% +doing and we've already provided a + + + align:start position:0% +doing and we've already provided a +useful successful product for the masses + + align:start position:0% +useful successful product for the masses + + + align:start position:0% +useful successful product for the masses +and there + + align:start position:0% +and there + + + align:start position:0% +and there +Um they have a ton you know they have uh + + align:start position:0% +Um they have a ton you know they have uh + + + align:start position:0% +Um they have a ton you know they have uh +40 partners 39 collaborating + + align:start position:0% +40 partners 39 collaborating + + + align:start position:0% +40 partners 39 collaborating +institutions of their collaborating + + align:start position:0% +institutions of their collaborating + + + align:start position:0% +institutions of their collaborating +institutions 77% are minority serving + + align:start position:0% +institutions 77% are minority serving + + + align:start position:0% +institutions 77% are minority serving +institutions so they're trying to start + + align:start position:0% +institutions so they're trying to start + + + align:start position:0% +institutions so they're trying to start +from the beginning saying you know we're + + align:start position:0% +from the beginning saying you know we're + + + align:start position:0% +from the beginning saying you know we're +not just going to do this to improve + + align:start position:0% +not just going to do this to improve + + + align:start position:0% +not just going to do this to improve +Colombia and Rice we're going to do this + + align:start position:0% +Colombia and Rice we're going to do this + + + align:start position:0% +Colombia and Rice we're going to do this +to improve you know lots of different + + align:start position:0% +to improve you know lots of different + + + align:start position:0% +to improve you know lots of different +kinds of organizations + + align:start position:0% +kinds of organizations + + + align:start position:0% +kinds of organizations +um it it also you know instead of being + + align:start position:0% +um it it also you know instead of being + + + align:start position:0% +um it it also you know instead of being +a consortium of states + + align:start position:0% +a consortium of states + + + align:start position:0% +a consortium of states +um it's really mostly a consortium of + + align:start position:0% +um it's really mostly a consortium of + + + align:start position:0% +um it's really mostly a consortium of +digital learning platforms. Um probably + + align:start position:0% +digital learning platforms. Um probably + + + align:start position:0% +digital learning platforms. Um probably +matters to like they're + + align:start position:0% +matters to like they're + + + align:start position:0% +matters to like they're +emphasis on college. Um I'm like + + align:start position:0% +emphasis on college. Um I'm like + + + align:start position:0% +emphasis on college. Um I'm like +assistance doesn't do anything for + + align:start position:0% +assistance doesn't do anything for + + + align:start position:0% +assistance doesn't do anything for +college. So they definitely have some + + align:start position:0% +college. So they definitely have some + + + align:start position:0% +college. So they definitely have some +things that are not I'm not sure it's + + align:start position:0% +things that are not I'm not sure it's + + + align:start position:0% +things that are not I'm not sure it's +literally true, but Assistments 99% of + + align:start position:0% +literally true, but Assistments 99% of + + + align:start position:0% +literally true, but Assistments 99% of +what they do is serve K12 students. Um, + + align:start position:0% +what they do is serve K12 students. Um, + + + align:start position:0% +what they do is serve K12 students. Um, +but I think it maybe does make a + + align:start position:0% +but I think it maybe does make a + + + align:start position:0% +but I think it maybe does make a +difference to, you know, in like like + + align:start position:0% +difference to, you know, in like like + + + align:start position:0% +difference to, you know, in like like +college students are adults. College + + align:start position:0% +college students are adults. College + + + align:start position:0% +college students are adults. College +students opt in to go to college. The + + align:start position:0% +students opt in to go to college. The + + + align:start position:0% +students opt in to go to college. The +state doesn't force anyone to go to + + align:start position:0% +state doesn't force anyone to go to + + + align:start position:0% +state doesn't force anyone to go to +college. And so you're just operating in + + align:start position:0% +college. And so you're just operating in + + + align:start position:0% +college. And so you're just operating in +a um in you maybe a luury choice, but + + align:start position:0% +a um in you maybe a luury choice, but + + + align:start position:0% +a um in you maybe a luury choice, but +there you're operating in a in a space + + align:start position:0% +there you're operating in a in a space + + + align:start position:0% +there you're operating in a in a space +where you feel like people have more + + align:start position:0% +where you feel like people have more + + + align:start position:0% +where you feel like people have more +agency to begin with to operate. Um they + + align:start position:0% +agency to begin with to operate. Um they + + + align:start position:0% +agency to begin with to operate. Um they +they you know unlike unlike Inloom which + + align:start position:0% +they you know unlike unlike Inloom which + + + align:start position:0% +they you know unlike unlike Inloom which +said these 11 states are the + + align:start position:0% +said these 11 states are the + + + align:start position:0% +said these 11 states are the +organization like these state education + + align:start position:0% +organization like these state education + + + align:start position:0% +organization like these state education +agencies are sort of the key people + + align:start position:0% +agencies are sort of the key people + + + align:start position:0% +agencies are sort of the key people +we're interacting with um they don't + + align:start position:0% +we're interacting with um they don't + + + align:start position:0% +we're interacting with um they don't +mention higher education accredititors + + align:start position:0% +mention higher education accredititors + + + align:start position:0% +mention higher education accredititors +or state boards of higher education or + + align:start position:0% +or state boards of higher education or + + + align:start position:0% +or state boards of higher education or +they basically have like left government + + align:start position:0% +they basically have like left government + + + align:start position:0% +they basically have like left government +out except for the National Science + + align:start position:0% +out except for the National Science + + + align:start position:0% +out except for the National Science +Foundation um of this development. Maybe + + align:start position:0% +Foundation um of this development. Maybe + + + align:start position:0% +Foundation um of this development. Maybe +people are more trustworthy of of these + + align:start position:0% +people are more trustworthy of of these + + + align:start position:0% +people are more trustworthy of of these +organizations or maybe they're just like + + align:start position:0% +organizations or maybe they're just like + + + align:start position:0% +organizations or maybe they're just like +even if they're not more trustworthy of + + align:start position:0% +even if they're not more trustworthy of + + + align:start position:0% +even if they're not more trustworthy of +these organizations, people are kind of + + align:start position:0% +these organizations, people are kind of + + + align:start position:0% +these organizations, people are kind of +drawn, critics are potentially drawn to + + align:start position:0% +drawn, critics are potentially drawn to + + + align:start position:0% +drawn, critics are potentially drawn to +things like New York State approves X, + + align:start position:0% +things like New York State approves X, + + + align:start position:0% +things like New York State approves X, +you know, versus this kind of like + + align:start position:0% +you know, versus this kind of like + + + align:start position:0% +you know, versus this kind of like +arbitrary group of universities, some of + + align:start position:0% +arbitrary group of universities, some of + + + align:start position:0% +arbitrary group of universities, some of +whom might be in New York, approve X. + + align:start position:0% +whom might be in New York, approve X. + + + align:start position:0% +whom might be in New York, approve X. +Um, so it'll be super interesting to + + align:start position:0% +Um, so it'll be super interesting to + + + align:start position:0% +Um, so it'll be super interesting to +watch. This is a um the grant that they + + align:start position:0% +watch. This is a um the grant that they + + + align:start position:0% +watch. This is a um the grant that they +got was from the same that $90 million + + align:start position:0% +got was from the same that $90 million + + + align:start position:0% +got was from the same that $90 million +is probably the largest federal grant uh + + align:start position:0% +is probably the largest federal grant uh + + + align:start position:0% +is probably the largest federal grant uh +um an educational research project ever. + + align:start position:0% +um an educational research project ever. + + + align:start position:0% +um an educational research project ever. +Although there's a couple of educational + + align:start position:0% +Although there's a couple of educational + + + align:start position:0% +Although there's a couple of educational +research projects that if you totaled up + + align:start position:0% +research projects that if you totaled up + + + align:start position:0% +research projects that if you totaled up +all the grants they got over a period of + + align:start position:0% +all the grants they got over a period of + + + align:start position:0% +all the grants they got over a period of +time might be sort of at least within + + align:start position:0% +time might be sort of at least within + + + align:start position:0% +time might be sort of at least within +that ballpark. Um it came from the same + + align:start position:0% +that ballpark. Um it came from the same + + + align:start position:0% +that ballpark. Um it came from the same +grant funding that supports like + + align:start position:0% +grant funding that supports like + + + align:start position:0% +grant funding that supports like +telescopes and ecological plots. um it's + + align:start position:0% +telescopes and ecological plots. um it's + + + align:start position:0% +telescopes and ecological plots. um it's +called midscale uh research + + align:start position:0% +called midscale uh research + + + align:start position:0% +called midscale uh research +infrastructure things that are like um + + align:start position:0% +infrastructure things that are like um + + + align:start position:0% +infrastructure things that are like um +where you know no one university can + + align:start position:0% +where you know no one university can + + + align:start position:0% +where you know no one university can +build like a giant radio telescope and + + align:start position:0% +build like a giant radio telescope and + + + align:start position:0% +build like a giant radio telescope and +and you don't want one university to you + + align:start position:0% +and you don't want one university to you + + + align:start position:0% +and you don't want one university to you +want to build a thing that like the + + align:start position:0% +want to build a thing that like the + + + align:start position:0% +want to build a thing that like the +entire field of astronomy can all + + align:start position:0% +entire field of astronomy can all + + + align:start position:0% +entire field of astronomy can all +collectively use together um and so this + + align:start position:0% +collectively use together um and so this + + + align:start position:0% +collectively use together um and so this +grant stream is meant to build enormous + + align:start position:0% +grant stream is meant to build enormous + + + align:start position:0% +grant stream is meant to build enormous +things that everyone can can use + + align:start position:0% +things that everyone can can use + + + align:start position:0% +things that everyone can can use +together so it'll be sort of interesting + + align:start position:0% +together so it'll be sort of interesting + + + align:start position:0% +together so it'll be sort of interesting +to see what they do um in the in the + + align:start position:0% +to see what they do um in the in the + + + align:start position:0% +to see what they do um in the in the +decades ahead but um I think a I mean + + align:start position:0% +decades ahead but um I think a I mean + + + align:start position:0% +decades ahead but um I think a I mean +you know in some ways especially coming + + align:start position:0% +you know in some ways especially coming + + + align:start position:0% +you know in some ways especially coming +about 10 years after the collapse of + + align:start position:0% +about 10 years after the collapse of + + + align:start position:0% +about 10 years after the collapse of +Inloom. Um, uh, it's to me it's sort of + + align:start position:0% +Inloom. Um, uh, it's to me it's sort of + + + align:start position:0% +Inloom. Um, uh, it's to me it's sort of +neat. You know, people still have + + align:start position:0% +neat. You know, people still have + + + align:start position:0% +neat. You know, people still have +optimism that if you pull together a + + align:start position:0% +optimism that if you pull together a + + + align:start position:0% +optimism that if you pull together a +bunch of student learning data, um, and + + align:start position:0% +bunch of student learning data, um, and + + + align:start position:0% +bunch of student learning data, um, and +data about students and you conduct a + + align:start position:0% +data about students and you conduct a + + + align:start position:0% +data about students and you conduct a +bunch of experiments, you can build + + align:start position:0% +bunch of experiments, you can build + + + align:start position:0% +bunch of experiments, you can build +things that help them learn better. Um, + + align:start position:0% +things that help them learn better. Um, + + + align:start position:0% +things that help them learn better. Um, +but there are, you know, there are re + + align:start position:0% +but there are, you know, there are re + + + align:start position:0% +but there are, you know, there are re +there are enormous real risks and there + + align:start position:0% +there are enormous real risks and there + + + align:start position:0% +there are enormous real risks and there +may be even more enormous um, kind of + + align:start position:0% +may be even more enormous um, kind of + + + align:start position:0% +may be even more enormous um, kind of +reputational risks that go into this + + align:start position:0% +reputational risks that go into this + + + align:start position:0% +reputational risks that go into this +work. Um, one thing that I've tried to + + align:start position:0% +work. Um, one thing that I've tried to + + + align:start position:0% +work. Um, one thing that I've tried to +communicate, which it sounds like these + + align:start position:0% +communicate, which it sounds like these + + + align:start position:0% +communicate, which it sounds like these +folks are, you know, are adopting to + + align:start position:0% +folks are, you know, are adopting to + + + align:start position:0% +folks are, you know, are adopting to +many different groups is like, you know, + + align:start position:0% +many different groups is like, you know, + + + align:start position:0% +many different groups is like, you know, +because I'm basically part of the + + align:start position:0% +because I'm basically part of the + + + align:start position:0% +because I'm basically part of the +community of people that would like to + + align:start position:0% +community of people that would like to + + + align:start position:0% +community of people that would like to +collect lots of data about students than + + align:start position:0% +collect lots of data about students than + + + align:start position:0% +collect lots of data about students than +I've done, you know, re, you know, I've + + align:start position:0% +I've done, you know, re, you know, I've + + + align:start position:0% +I've done, you know, re, you know, I've +I've I've handled data files that have + + align:start position:0% +I've I've handled data files that have + + + align:start position:0% +I've I've handled data files that have +like way more information about people + + align:start position:0% +like way more information about people + + + align:start position:0% +like way more information about people +than I feel comfortable having access + + align:start position:0% +than I feel comfortable having access + + + align:start position:0% +than I feel comfortable having access +to. Um, and part of the job is doing + + align:start position:0% +to. Um, and part of the job is doing + + + align:start position:0% +to. Um, and part of the job is doing +things responsibly, but the other part + + align:start position:0% +things responsibly, but the other part + + + align:start position:0% +things responsibly, but the other part +of the job is like constantly talking to + + align:start position:0% +of the job is like constantly talking to + + + align:start position:0% +of the job is like constantly talking to +the public about what we're doing. Um, + + align:start position:0% +the public about what we're doing. Um, + + + align:start position:0% +the public about what we're doing. Um, +you know, the only way people will not + + align:start position:0% +you know, the only way people will not + + + align:start position:0% +you know, the only way people will not +be creeped out by doing experiments, um, + + align:start position:0% +be creeped out by doing experiments, um, + + + align:start position:0% +be creeped out by doing experiments, um, +is if a we conduct a bunch of + + align:start position:0% +is if a we conduct a bunch of + + + align:start position:0% +is if a we conduct a bunch of +experiments that meaningfully improve + + align:start position:0% +experiments that meaningfully improve + + + align:start position:0% +experiments that meaningfully improve +learning. Um, a hu a huge challenge that + + align:start position:0% +learning. Um, a hu a huge challenge that + + + align:start position:0% +learning. Um, a hu a huge challenge that +education has, um, is like we don't have + + align:start position:0% +education has, um, is like we don't have + + + align:start position:0% +education has, um, is like we don't have +the equivalent of the human genome + + align:start position:0% +the equivalent of the human genome + + + align:start position:0% +the equivalent of the human genome +project. We don't have a thing that you + + align:start position:0% +project. We don't have a thing that you + + + align:start position:0% +project. We don't have a thing that you +could point to being like, well, yeah, + + align:start position:0% +could point to being like, well, yeah, + + + align:start position:0% +could point to being like, well, yeah, +we took a whole lot of your data, but + + align:start position:0% +we took a whole lot of your data, but + + + align:start position:0% +we took a whole lot of your data, but +like we're curing cancer here, people. + + align:start position:0% +like we're curing cancer here, people. + + + align:start position:0% +like we're curing cancer here, people. +Um, you know, I mean, if if Safe + + align:start position:0% +Um, you know, I mean, if if Safe + + + align:start position:0% +Um, you know, I mean, if if Safe +Insights came up with something that + + align:start position:0% +Insights came up with something that + + + align:start position:0% +Insights came up with something that +made students learn math 33% faster, it + + align:start position:0% +made students learn math 33% faster, it + + + align:start position:0% +made students learn math 33% faster, it +would totally change the way people + + align:start position:0% +would totally change the way people + + + align:start position:0% +would totally change the way people +think about the collection of D. So, + + align:start position:0% +think about the collection of D. So, + + + align:start position:0% +think about the collection of D. So, +your costbenefit data would transform um + + align:start position:0% +your costbenefit data would transform um + + + align:start position:0% +your costbenefit data would transform um +uh quite dramatically. Um, but even in + + align:start position:0% +uh quite dramatically. Um, but even in + + + align:start position:0% +uh quite dramatically. Um, but even in +the absence of that, like it's + + align:start position:0% +the absence of that, like it's + + + align:start position:0% +the absence of that, like it's +incredibly important to be engaged with + + align:start position:0% +incredibly important to be engaged with + + + align:start position:0% +incredibly important to be engaged with +these student privacy groups, engaged + + align:start position:0% +these student privacy groups, engaged + + + align:start position:0% +these student privacy groups, engaged +with families, trying to explain to + + align:start position:0% +with families, trying to explain to + + + align:start position:0% +with families, trying to explain to +people like there's always going to be + + align:start position:0% +people like there's always going to be + + + align:start position:0% +people like there's always going to be +variation in education. Um, what we + + align:start position:0% +variation in education. Um, what we + + + align:start position:0% +variation in education. Um, what we +probably could benefit the most from is + + align:start position:0% +probably could benefit the most from is + + + align:start position:0% +probably could benefit the most from is +systematic variation where we can tell + + align:start position:0% +systematic variation where we can tell + + + align:start position:0% +systematic variation where we can tell +which parts of the variation work and + + align:start position:0% +which parts of the variation work and + + + align:start position:0% +which parts of the variation work and +which parts don't. And the only way that + + align:start position:0% +which parts don't. And the only way that + + + align:start position:0% +which parts don't. And the only way that +we can do that is through some of these + + align:start position:0% +we can do that is through some of these + + + align:start position:0% +we can do that is through some of these +approaches that include data collection + + align:start position:0% +approaches that include data collection + + + align:start position:0% +approaches that include data collection +and randomization and things like that. + + align:start position:0% +and randomization and things like that. + + + align:start position:0% +and randomization and things like that. +So you just like made the statement that + + align:start position:0% +So you just like made the statement that + + + align:start position:0% +So you just like made the statement that +like safe insights comes up with like + + align:start position:0% +like safe insights comes up with like + + + align:start position:0% +like safe insights comes up with like +some solution. So is safe insights kind + + align:start position:0% +some solution. So is safe insights kind + + + align:start position:0% +some solution. So is safe insights kind +of like that is it like a third party + + align:start position:0% +of like that is it like a third party + + + align:start position:0% +of like that is it like a third party +that is it is less of a third party than + + align:start position:0% +that is it is less of a third party than + + + align:start position:0% +that is it is less of a third party than +in bloom. Yes. you know, like clearly + + align:start position:0% +in bloom. Yes. you know, like clearly + + + align:start position:0% +in bloom. Yes. you know, like clearly +some of the things that that Rice is + + align:start position:0% +some of the things that that Rice is + + + align:start position:0% +some of the things that that Rice is +going to do with his money is build + + align:start position:0% +going to do with his money is build + + + align:start position:0% +going to do with his money is build +systems and study open stacks with it. + + align:start position:0% +systems and study open stacks with it. + + + align:start position:0% +systems and study open stacks with it. +Um, like part like much more so than + + align:start position:0% +Um, like part like much more so than + + + align:start position:0% +Um, like part like much more so than +Inloom. Um, in in Bloom didn't have a In + + align:start position:0% +Inloom. Um, in in Bloom didn't have a In + + + align:start position:0% +Inloom. Um, in in Bloom didn't have a In +Bloom never, to my knowledge, never had + + align:start position:0% +Bloom never, to my knowledge, never had + + + align:start position:0% +Bloom never, to my knowledge, never had +a list of partners that looked like this + + align:start position:0% +a list of partners that looked like this + + + align:start position:0% +a list of partners that looked like this +list. Um, they never said from the + + align:start position:0% +list. Um, they never said from the + + + align:start position:0% +list. Um, they never said from the +beginning, oh look, like Cahoot and + + align:start position:0% +beginning, oh look, like Cahoot and + + + align:start position:0% +beginning, oh look, like Cahoot and +Google Classroom and the all these other + + align:start position:0% +Google Classroom and the all these other + + + align:start position:0% +Google Classroom and the all these other +people are our lead partners. um and are + + align:start position:0% +people are our lead partners. um and are + + + align:start position:0% +people are our lead partners. um and are +going to use this to figure out stuff. + + align:start position:0% +going to use this to figure out stuff. + + + align:start position:0% +going to use this to figure out stuff. +They they like really saw themselves + + align:start position:0% +They they like really saw themselves + + + align:start position:0% +They they like really saw themselves +solving an infrastructural problem um + + align:start position:0% +solving an infrastructural problem um + + + align:start position:0% +solving an infrastructural problem um +more that you know like I I think these + + align:start position:0% +more that you know like I I think these + + + align:start position:0% +more that you know like I I think these +folks are positioning themselves more + + align:start position:0% +folks are positioning themselves more + + + align:start position:0% +folks are positioning themselves more +like first we're going to have a set of + + align:start position:0% +like first we're going to have a set of + + + align:start position:0% +like first we're going to have a set of +tech products that improve learning um + + align:start position:0% +tech products that improve learning um + + + align:start position:0% +tech products that improve learning um +through better research practices + + align:start position:0% +through better research practices + + + align:start position:0% +through better research practices +including better forms of data + + align:start position:0% +including better forms of data + + + align:start position:0% +including better forms of data +management and data sharing and data + + align:start position:0% +management and data sharing and data + + + align:start position:0% +management and data sharing and data +privacy. Um, but if it like if it's a + + align:start position:0% +privacy. Um, but if it like if it's a + + + align:start position:0% +privacy. Um, but if it like if it's a +real infrastructure product, like part + + align:start position:0% +real infrastructure product, like part + + + align:start position:0% +real infrastructure product, like part +of what you know, I'm I'm sure Rich's + + align:start position:0% +of what you know, I'm I'm sure Rich's + + + align:start position:0% +of what you know, I'm I'm sure Rich's +goal um is to say we're going to develop + + align:start position:0% +goal um is to say we're going to develop + + + align:start position:0% +goal um is to say we're going to develop +these research these privacy protecting + + align:start position:0% +these research these privacy protecting + + + align:start position:0% +these research these privacy protecting +research enclaves and we're going to + + align:start position:0% +research enclaves and we're going to + + + align:start position:0% +research enclaves and we're going to +develop them in an open source way that + + align:start position:0% +develop them in an open source way that + + + align:start position:0% +develop them in an open source way that +like whatever future edtech companies + + align:start position:0% +like whatever future edtech companies + + + align:start position:0% +like whatever future edtech companies +come along are going to be able to + + align:start position:0% +come along are going to be able to + + + align:start position:0% +come along are going to be able to +benefit from this infrastructure. Like + + align:start position:0% +benefit from this infrastructure. Like + + + align:start position:0% +benefit from this infrastructure. Like +they're going to be able to do all the + + align:start position:0% +they're going to be able to do all the + + + align:start position:0% +they're going to be able to do all the +same kinds of things that OpenStacks is + + align:start position:0% +same kinds of things that OpenStacks is + + + align:start position:0% +same kinds of things that OpenStacks is +doing to conduct cool experimental + + align:start position:0% +doing to conduct cool experimental + + + align:start position:0% +doing to conduct cool experimental +research with lots of data while + + align:start position:0% +research with lots of data while + + + align:start position:0% +research with lots of data while +protecting people's privacy. Um, + + align:start position:0% +protecting people's privacy. Um, + + + align:start position:0% +protecting people's privacy. Um, +Great. It's 2:25. Um, so I should let + + align:start position:0% +Great. It's 2:25. Um, so I should let + + + align:start position:0% +Great. It's 2:25. Um, so I should let +you go. We'll come in on Wednesday. Um, + + align:start position:0% +you go. We'll come in on Wednesday. Um, + + + align:start position:0% +you go. We'll come in on Wednesday. Um, +and we'll you have a little bit of + + align:start position:0% +and we'll you have a little bit of + + + align:start position:0% +and we'll you have a little bit of +reading about implementation in schools. + + align:start position:0% +reading about implementation in schools. + + + align:start position:0% +reading about implementation in schools. +Um, but mostly uh what you should be + + align:start position:0% +Um, but mostly uh what you should be + + + align:start position:0% +Um, but mostly uh what you should be +working on is um getting some words on + + align:start position:0% +working on is um getting some words on + + + align:start position:0% +working on is um getting some words on +paper for your final product um project + + align:start position:0% +paper for your final product um project + + + align:start position:0% +paper for your final product um project +and thinking a little bit. Oh, a thing + + align:start position:0% +and thinking a little bit. Oh, a thing + + + align:start position:0% +and thinking a little bit. Oh, a thing +that we'll do probably by email this + + align:start position:0% +that we'll do probably by email this + + + align:start position:0% +that we'll do probably by email this +week, but maybe a bit in class on + + align:start position:0% +week, but maybe a bit in class on + + + align:start position:0% +week, but maybe a bit in class on +Wednesday is I need you to sign up um to + + align:start position:0% +Wednesday is I need you to sign up um to + + + align:start position:0% +Wednesday is I need you to sign up um to +either present on Monday or Wednesday. + + align:start position:0% +either present on Monday or Wednesday. + + + align:start position:0% +either present on Monday or Wednesday. +Um, maybe I'll send you something pretty + + align:start position:0% +Um, maybe I'll send you something pretty + + + align:start position:0% +Um, maybe I'll send you something pretty +soon that invites you to sign up for one + + align:start position:0% +soon that invites you to sign up for one + + + align:start position:0% +soon that invites you to sign up for one +of those two slots. \ No newline at end of file diff --git a/uJk4b8VsC6c.txt b/uJk4b8VsC6c.txt new file mode 100644 index 0000000000000000000000000000000000000000..71e8dbb29c680ab90aafacc27f460d8516f516a0 --- /dev/null +++ b/uJk4b8VsC6c.txt @@ -0,0 +1,8315 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay so I want to talk a + + align:start position:0% +ocw.mit.edu okay so I want to talk a + + + align:start position:0% +ocw.mit.edu okay so I want to talk a +little bit about foraging behavior and + + align:start position:0% +little bit about foraging behavior and + + + align:start position:0% +little bit about foraging behavior and +then that will be followed + + align:start position:0% +then that will be followed + + + align:start position:0% +then that will be followed +by some things on anti-predator behavior + + align:start position:0% +by some things on anti-predator behavior + + + align:start position:0% +by some things on anti-predator behavior +and those will be the last topics before + + align:start position:0% +and those will be the last topics before + + + align:start position:0% +and those will be the last topics before +the + + align:start position:0% + + + + align:start position:0% + +midterm we will finish anti- Predator + + align:start position:0% +midterm we will finish anti- Predator + + + align:start position:0% +midterm we will finish anti- Predator +Behavior next Friday but we it should + + align:start position:0% +Behavior next Friday but we it should + + + align:start position:0% +Behavior next Friday but we it should +leave time because we'll start that on + + align:start position:0% +leave time because we'll start that on + + + align:start position:0% +leave time because we'll start that on +Wednesday we should have time uh for + + align:start position:0% +Wednesday we should have time uh for + + + align:start position:0% +Wednesday we should have time uh for +some + + align:start position:0% +some + + + align:start position:0% +some +reviewing since the exam is on Monday + + align:start position:0% +reviewing since the exam is on Monday + + + align:start position:0% +reviewing since the exam is on Monday +the Monday not next Monday but the + + align:start position:0% +the Monday not next Monday but the + + + align:start position:0% +the Monday not next Monday but the +following + + align:start position:0% +following + + + align:start position:0% +following +Monday + + align:start position:0% + + + + align:start position:0% + +okay now this this first question you + + align:start position:0% +okay now this this first question you + + + align:start position:0% +okay now this this first question you +should be able to answer by now because + + align:start position:0% +should be able to answer by now because + + + align:start position:0% +should be able to answer by now because +it's come out + + align:start position:0% +it's come out + + + align:start position:0% +it's come out +before does the level of foraging or + + align:start position:0% +before does the level of foraging or + + + align:start position:0% +before does the level of foraging or +hunting depend on the amount of + + align:start position:0% +hunting depend on the amount of + + + align:start position:0% +hunting depend on the amount of +hunger is it independent of + + align:start position:0% +hunger is it independent of + + + align:start position:0% +hunger is it independent of +hunger and the reason I rais the + + align:start position:0% +hunger and the reason I rais the + + + align:start position:0% +hunger and the reason I rais the +question again is because in the reading + + align:start position:0% +question again is because in the reading + + + align:start position:0% +question again is because in the reading +by Scott + + align:start position:0% +by Scott + + + align:start position:0% +by Scott +uh he paints a somewhat different + + align:start position:0% +uh he paints a somewhat different + + + align:start position:0% +uh he paints a somewhat different +picture than + + align:start position:0% +picture than + + + align:start position:0% +picture than +the one we learned about from Conrad + + align:start position:0% +the one we learned about from Conrad + + + align:start position:0% +the one we learned about from Conrad +Lawrence and Le's work with cats and + + align:start position:0% +Lawrence and Le's work with cats and + + + align:start position:0% +Lawrence and Le's work with cats and +John Flynn's work with cat brain + + align:start position:0% +John Flynn's work with cat brain + + + align:start position:0% +John Flynn's work with cat brain +stimulation so what's the simple + + align:start position:0% + + + + align:start position:0% + +answer is it dependent on + + align:start position:0% +answer is it dependent on + + + align:start position:0% +answer is it dependent on +Hunger or not in fact in some of the + + align:start position:0% +Hunger or not in fact in some of the + + + align:start position:0% +Hunger or not in fact in some of the +videos I show occasionally you will hear + + align:start position:0% +videos I show occasionally you will hear + + + align:start position:0% +videos I show occasionally you will hear +mention this they people just + + align:start position:0% +mention this they people just + + + align:start position:0% +mention this they people just +assume that if they're not hungry they + + align:start position:0% +assume that if they're not hungry they + + + align:start position:0% +assume that if they're not hungry they +won't hunt and + + align:start position:0% + + + + align:start position:0% + +they well you'll see we're going to see + + align:start position:0% +they well you'll see we're going to see + + + align:start position:0% +they well you'll see we're going to see +a video next week well you'll get an + + align:start position:0% +a video next week well you'll get an + + + align:start position:0% +a video next week well you'll get an +example of that that contradicts some of + + align:start position:0% +example of that that contradicts some of + + + align:start position:0% +example of that that contradicts some of +the ethological studies that we know + + align:start position:0% +the ethological studies that we know + + + align:start position:0% +the ethological studies that we know +about + + align:start position:0% +about + + + align:start position:0% +about +so God doesn't make it clear that some + + align:start position:0% +so God doesn't make it clear that some + + + align:start position:0% +so God doesn't make it clear that some +andate foraging drives are separate from + + align:start position:0% +andate foraging drives are separate from + + + align:start position:0% +andate foraging drives are separate from +Hunger but remember we just + + align:start position:0% +Hunger but remember we just + + + align:start position:0% +Hunger but remember we just +uh this before but Scott does introduce + + align:start position:0% +uh this before but Scott does introduce + + + align:start position:0% +uh this before but Scott does introduce +one more thing this he uh on page 120 he + + align:start position:0% +one more thing this he uh on page 120 he + + + align:start position:0% +one more thing this he uh on page 120 he +talks + + align:start position:0% +talks + + + align:start position:0% +talks +about role of social cues and of + + align:start position:0% +about role of social cues and of + + + align:start position:0% +about role of social cues and of +learning so my question here is why + + align:start position:0% +learning so my question here is why + + + align:start position:0% +learning so my question here is why +might an animal eat more when feeding + + align:start position:0% +might an animal eat more when feeding + + + align:start position:0% +might an animal eat more when feeding +with a group + + align:start position:0% +with a group + + + align:start position:0% +with a group +of of + + align:start position:0% +of of + + + align:start position:0% +of of +his conp + + align:start position:0% +his conp + + + align:start position:0% +his conp +specifics uh than it would if it was + + align:start position:0% +specifics uh than it would if it was + + + align:start position:0% +specifics uh than it would if it was +feeding alone + + align:start position:0% + + + + align:start position:0% + +in fact sometimes a a monkey group if he + + align:start position:0% +in fact sometimes a a monkey group if he + + + align:start position:0% +in fact sometimes a a monkey group if he +he'll finish feeding alone but then if + + align:start position:0% +he'll finish feeding alone but then if + + + align:start position:0% +he'll finish feeding alone but then if +there're suddenly he's with a group you + + align:start position:0% +there're suddenly he's with a group you + + + align:start position:0% +there're suddenly he's with a group you +know he will start eating more if + + align:start position:0% +know he will start eating more if + + + align:start position:0% +know he will start eating more if +they're all + + align:start position:0% + + + + align:start position:0% + +eating so why what do you think is + + align:start position:0% +eating so why what do you think is + + + align:start position:0% +eating so why what do you think is +behind that why would that + + align:start position:0% +behind that why would that + + + align:start position:0% +behind that why would that +evolve and when you think when I ask you + + align:start position:0% +evolve and when you think when I ask you + + + align:start position:0% +evolve and when you think when I ask you +a question like that why it would evolve + + align:start position:0% +a question like that why it would evolve + + + align:start position:0% +a question like that why it would evolve +what I want you to think about is what + + align:start position:0% +what I want you to think about is what + + + align:start position:0% +what I want you to think about is what +is the benefit for the + + align:start position:0% +is the benefit for the + + + align:start position:0% +is the benefit for the +individual what's the selfish reason why + + align:start position:0% +individual what's the selfish reason why + + + align:start position:0% +individual what's the selfish reason why +an animal would do + + align:start position:0% +an animal would do + + + align:start position:0% +an animal would do +that I mean right he he ate to satiation + + align:start position:0% +that I mean right he he ate to satiation + + + align:start position:0% +that I mean right he he ate to satiation +he shouldn't be hungry so why would he + + align:start position:0% +he shouldn't be hungry so why would he + + + align:start position:0% +he shouldn't be hungry so why would he +now start + + align:start position:0% + + + + align:start position:0% + +eating did you read + + align:start position:0% +eating did you read + + + align:start position:0% +eating did you read +it because God does suggest the reason + + align:start position:0% +it because God does suggest the reason + + + align:start position:0% +it because God does suggest the reason +and + + align:start position:0% + + + + align:start position:0% + +read if all the other animals there's a + + align:start position:0% +read if all the other animals there's a + + + align:start position:0% +read if all the other animals there's a +limited amount of food there and if + + align:start position:0% +limited amount of food there and if + + + align:start position:0% +limited amount of food there and if +they're all eating it there's not going + + align:start position:0% +they're all eating it there's not going + + + align:start position:0% +they're all eating it there's not going +to be anything + + align:start position:0% + + + + align:start position:0% + +left and animals need to maximize their + + align:start position:0% +left and animals need to maximize their + + + align:start position:0% +left and animals need to maximize their +food + + align:start position:0% +food + + + align:start position:0% +food +intake to survive so he's an animal will + + align:start position:0% +intake to survive so he's an animal will + + + align:start position:0% +intake to survive so he's an animal will +eat + + align:start position:0% +eat + + + align:start position:0% +eat +more in a social + + align:start position:0% +more in a social + + + align:start position:0% +more in a social +group for just that selfish + + align:start position:0% + + + + align:start position:0% + +reason + + align:start position:0% +reason + + + align:start position:0% +reason +eat it before it's all + + align:start position:0% +eat it before it's all + + + align:start position:0% +eat it before it's all +gone and that's why we think that + + align:start position:0% +gone and that's why we think that + + + align:start position:0% +gone and that's why we think that +tendency evolved it's also sometimes + + align:start position:0% +tendency evolved it's also sometimes + + + align:start position:0% +tendency evolved it's also sometimes +just called social social + + align:start position:0% +just called social social + + + align:start position:0% +just called social social +facilitation uh by social + + align:start position:0% +facilitation uh by social + + + align:start position:0% +facilitation uh by social +psychologists but here in animal + + align:start position:0% +psychologists but here in animal + + + align:start position:0% +psychologists but here in animal +behavior you can call it social + + align:start position:0% +behavior you can call it social + + + align:start position:0% +behavior you can call it social +facilitation but there is a specific + + align:start position:0% +facilitation but there is a specific + + + align:start position:0% +facilitation but there is a specific +reason why that should evolve as in + + align:start position:0% +reason why that should evolve as in + + + align:start position:0% +reason why that should evolve as in +behavior let's go to the next topic here + + align:start position:0% +behavior let's go to the next topic here + + + align:start position:0% +behavior let's go to the next topic here +on condition taste + + align:start position:0% +on condition taste + + + align:start position:0% +on condition taste +aversion it's also called the poison + + align:start position:0% +aversion it's also called the poison + + + align:start position:0% +aversion it's also called the poison +bait + + align:start position:0% +bait + + + align:start position:0% +bait +effect and Scott calls it a form of + + align:start position:0% +effect and Scott calls it a form of + + + align:start position:0% +effect and Scott calls it a form of +classical + + align:start position:0% +classical + + + align:start position:0% +classical +conditioning and uh in fact he has a + + align:start position:0% +conditioning and uh in fact he has a + + + align:start position:0% +conditioning and uh in fact he has a +there's a box in the book there in page + + align:start position:0% +there's a box in the book there in page + + + align:start position:0% +there's a box in the book there in page +122 where he goes through that and + + align:start position:0% +122 where he goes through that and + + + align:start position:0% +122 where he goes through that and +he it was discovered by John Garcia in + + align:start position:0% +he it was discovered by John Garcia in + + + align:start position:0% +he it was discovered by John Garcia in +California uh it has property that do + + align:start position:0% +California uh it has property that do + + + align:start position:0% +California uh it has property that do +not fit the descriptions of classical + + align:start position:0% +not fit the descriptions of classical + + + align:start position:0% +not fit the descriptions of classical +conditioning and this is + + align:start position:0% +conditioning and this is + + + align:start position:0% +conditioning and this is +why for one thing it's something the + + align:start position:0% +why for one thing it's something the + + + align:start position:0% +why for one thing it's something the +animal learns in one + + align:start position:0% +animal learns in one + + + align:start position:0% +animal learns in one +trial and almost all CL there are + + align:start position:0% +trial and almost all CL there are + + + align:start position:0% +trial and almost all CL there are +examples of other one trial + + align:start position:0% +examples of other one trial + + + align:start position:0% +examples of other one trial +learning like a rat stepping down from a + + align:start position:0% +learning like a rat stepping down from a + + + align:start position:0% +learning like a rat stepping down from a +platform onto an electrified grid he + + align:start position:0% +platform onto an electrified grid he + + + align:start position:0% +platform onto an electrified grid he +will learn in one trial not to step down + + align:start position:0% +will learn in one trial not to step down + + + align:start position:0% +will learn in one trial not to step down +but most things takes longer to learn at + + align:start position:0% +but most things takes longer to learn at + + + align:start position:0% +but most things takes longer to learn at +least with positive reinforcement that's + + align:start position:0% +least with positive reinforcement that's + + + align:start position:0% +least with positive reinforcement that's +true in this case it's it's not only + + align:start position:0% +true in this case it's it's not only + + + align:start position:0% +true in this case it's it's not only +only just one trial learning + + align:start position:0% +only just one trial learning + + + align:start position:0% +only just one trial learning +but this so-called unconditioned + + align:start position:0% +but this so-called unconditioned + + + align:start position:0% +but this so-called unconditioned +response where the animal gets + + align:start position:0% + + + + align:start position:0% + +sick and feels nauseated as a result of + + align:start position:0% +sick and feels nauseated as a result of + + + align:start position:0% +sick and feels nauseated as a result of +eating a lot of times that sickness + + align:start position:0% +eating a lot of times that sickness + + + align:start position:0% +eating a lot of times that sickness +doesn't occur immediately it takes a + + align:start position:0% +doesn't occur immediately it takes a + + + align:start position:0% +doesn't occur immediately it takes a +little while and yet they still learn to + + align:start position:0% +little while and yet they still learn to + + + align:start position:0% +little while and yet they still learn to +avoid that + + align:start position:0% +avoid that + + + align:start position:0% +avoid that +food and the third thing is that the + + align:start position:0% +food and the third thing is that the + + + align:start position:0% +food and the third thing is that the +memory is much more long lasting than + + align:start position:0% +memory is much more long lasting than + + + align:start position:0% +memory is much more long lasting than +you find in classical conditioning okay + + align:start position:0% +you find in classical conditioning okay + + + align:start position:0% +you find in classical conditioning okay +humans that have experienced this and + + align:start position:0% +humans that have experienced this and + + + align:start position:0% +humans that have experienced this and +many of us have it can last for + + align:start position:0% +many of us have it can last for + + + align:start position:0% +many of us have it can last for +years for example I when I was a + + align:start position:0% +years for example I when I was a + + + align:start position:0% +years for example I when I was a +kid uh I was probably on the verge of + + align:start position:0% +kid uh I was probably on the verge of + + + align:start position:0% +kid uh I was probably on the verge of +getting the stomach flu but didn't know + + align:start position:0% +getting the stomach flu but didn't know + + + align:start position:0% +getting the stomach flu but didn't know +it but we were having a we were roasting + + align:start position:0% +it but we were having a we were roasting + + + align:start position:0% +it but we were having a we were roasting +marshmallows and I was I got often we + + align:start position:0% +marshmallows and I was I got often we + + + align:start position:0% +marshmallows and I was I got often we +not only Brown them we burned them a + + align:start position:0% +not only Brown them we burned them a + + + align:start position:0% +not only Brown them we burned them a +little bit and I ate a partially burnt + + align:start position:0% +little bit and I ate a partially burnt + + + align:start position:0% +little bit and I ate a partially burnt +marshmallow got sick afterwards or felt + + align:start position:0% +marshmallow got sick afterwards or felt + + + align:start position:0% +marshmallow got sick afterwards or felt +terribly sick and I couldn't stand the + + align:start position:0% +terribly sick and I couldn't stand the + + + align:start position:0% +terribly sick and I couldn't stand the +sight of that kind of marshmallow for 20 + + align:start position:0% + + + + align:start position:0% + +years a very + + align:start position:0% +years a very + + + align:start position:0% +years a very +clear poison bait + + align:start position:0% +clear poison bait + + + align:start position:0% +clear poison bait +effect it didn't matter whether the + + align:start position:0% +effect it didn't matter whether the + + + align:start position:0% +effect it didn't matter whether the +illness was really caused by the + + align:start position:0% +illness was really caused by the + + + align:start position:0% +illness was really caused by the +marshmallow because other people didn't + + align:start position:0% +marshmallow because other people didn't + + + align:start position:0% +marshmallow because other people didn't +get sick from + + align:start position:0% +get sick from + + + align:start position:0% +get sick from +it I think I was getting sick anyway how + + align:start position:0% +it I think I was getting sick anyway how + + + align:start position:0% +it I think I was getting sick anyway how +many people here have experienced that + + align:start position:0% +many people here have experienced that + + + align:start position:0% +many people here have experienced that +kind of effect in their lives about a + + align:start position:0% +kind of effect in their lives about a + + + align:start position:0% +kind of effect in their lives about a +third of + + align:start position:0% +third of + + + align:start position:0% +third of +you does anybody want to tell us give us + + align:start position:0% +you does anybody want to tell us give us + + + align:start position:0% +you does anybody want to tell us give us +an + + align:start position:0% + + + + align:start position:0% + +example they might like to hear + + align:start position:0% + + + + align:start position:0% + +it come on one of you tell tell us what + + align:start position:0% +it come on one of you tell tell us what + + + align:start position:0% +it come on one of you tell tell us what +you + + align:start position:0% + + + + align:start position:0% + +experienced yeah anyway + + align:start position:0% +experienced yeah anyway + + + align:start position:0% +experienced yeah anyway +um well like this I don't know meat just + + align:start position:0% +um well like this I don't know meat just + + + align:start position:0% +um well like this I don't know meat just +like I don't know it just makes me feel + + align:start position:0% +like I don't know it just makes me feel + + + align:start position:0% +like I don't know it just makes me feel +sick so I mean like I don't know what + + align:start position:0% +sick so I mean like I don't know what + + + align:start position:0% +sick so I mean like I don't know what +did you eat like it was it was I don't + + align:start position:0% +did you eat like it was it was I don't + + + align:start position:0% +did you eat like it was it was I don't +want to describe it was kind of good + + align:start position:0% +want to describe it was kind of good + + + align:start position:0% +want to describe it was kind of good +well that's okay I + + align:start position:0% + + + + align:start position:0% + +do it was like ground up meat and it has + + align:start position:0% +do it was like ground up meat and it has + + + align:start position:0% +do it was like ground up meat and it has +like fillers in it and I don't know I + + align:start position:0% +like fillers in it and I don't know I + + + align:start position:0% +like fillers in it and I don't know I +just decided it really gr me out + + align:start position:0% +just decided it really gr me out + + + align:start position:0% +just decided it really gr me out +I felt you felt nauseated afterwards and + + align:start position:0% +I felt you felt nauseated afterwards and + + + align:start position:0% +I felt you felt nauseated afterwards and +that's mainly the the what causes the + + align:start position:0% +that's mainly the the what causes the + + + align:start position:0% +that's mainly the the what causes the +effect and so + + align:start position:0% +effect and so + + + align:start position:0% +effect and so +you how did it affect you later I just + + align:start position:0% +you how did it affect you later I just + + + align:start position:0% +you how did it affect you later I just +didn't eat + + align:start position:0% +didn't eat + + + align:start position:0% +didn't eat +like things that you wouldn't eat + + align:start position:0% +like things that you wouldn't eat + + + align:start position:0% +like things that you wouldn't eat +anything like it right for how long or + + align:start position:0% +anything like it right for how long or + + + align:start position:0% +anything like it right for how long or +is it still there um I got over it I + + align:start position:0% +is it still there um I got over it I + + + align:start position:0% +is it still there um I got over it I +think well this happened to me when I + + align:start position:0% +think well this happened to me when I + + + align:start position:0% +think well this happened to me when I +was about I would say 7 years old and uh + + align:start position:0% +was about I would say 7 years old and uh + + + align:start position:0% +was about I would say 7 years old and uh +I was + + align:start position:0% +I was + + + align:start position:0% +I was +certainly probably 30 years old before I + + align:start position:0% +certainly probably 30 years old before I + + + align:start position:0% +certainly probably 30 years old before I +could eat a marshmallow like + + align:start position:0% +could eat a marshmallow like + + + align:start position:0% +could eat a marshmallow like +that all right so it's not really what + + align:start position:0% +that all right so it's not really what + + + align:start position:0% +that all right so it's not really what +is it then if it's not classical + + align:start position:0% +is it then if it's not classical + + + align:start position:0% +is it then if it's not classical +conditioning uh Scott has written that + + align:start position:0% +conditioning uh Scott has written that + + + align:start position:0% +conditioning uh Scott has written that +Comm condition taste diversion is of + + align:start position:0% +Comm condition taste diversion is of + + + align:start position:0% +Comm condition taste diversion is of +course a form of classical conditioning + + align:start position:0% +course a form of classical conditioning + + + align:start position:0% +course a form of classical conditioning +why would he say that the reason is + + align:start position:0% +why would he say that the reason is + + + align:start position:0% +why would he say that the reason is +first of all many learning theorists + + align:start position:0% +first of all many learning theorists + + + align:start position:0% +first of all many learning theorists +theorists have lumped all learning into + + align:start position:0% +theorists have lumped all learning into + + + align:start position:0% +theorists have lumped all learning into +just a few categories and many textbooks + + align:start position:0% +just a few categories and many textbooks + + + align:start position:0% +just a few categories and many textbooks +on learning are they're organized that + + align:start position:0% +on learning are they're organized that + + + align:start position:0% +on learning are they're organized that +way the few major sections classical + + align:start position:0% +way the few major sections classical + + + align:start position:0% +way the few major sections classical +conditioning instrumental conditioning + + align:start position:0% +conditioning instrumental conditioning + + + align:start position:0% +conditioning instrumental conditioning +and now they usually have a few other + + align:start position:0% +and now they usually have a few other + + + align:start position:0% +and now they usually have a few other +types + + align:start position:0% +types + + + align:start position:0% +types +to and also many people including many + + align:start position:0% +to and also many people including many + + + align:start position:0% +to and also many people including many +scientists have believed that you know + + align:start position:0% +scientists have believed that you know + + + align:start position:0% +scientists have believed that you know +from the class before that almost every + + align:start position:0% +from the class before that almost every + + + align:start position:0% +from the class before that almost every +Behavior's learned especially here in + + align:start position:0% +Behavior's learned especially here in + + + align:start position:0% +Behavior's learned especially here in +America what Lauren Lawrence calls this + + align:start position:0% +America what Lauren Lawrence calls this + + + align:start position:0% +America what Lauren Lawrence calls this +form of learning an innate disposition + + align:start position:0% +form of learning an innate disposition + + + align:start position:0% +form of learning an innate disposition +for + + align:start position:0% +for + + + align:start position:0% +for +learning the innate School + + align:start position:0% +learning the innate School + + + align:start position:0% +learning the innate School +mm it shows us evidence for a built-in + + align:start position:0% +mm it shows us evidence for a built-in + + + align:start position:0% +mm it shows us evidence for a built-in +program for a particular kind of + + align:start position:0% +program for a particular kind of + + + align:start position:0% +program for a particular kind of +learning that it's very easy to + + align:start position:0% +learning that it's very easy to + + + align:start position:0% +learning that it's very easy to +understand why that would be + + align:start position:0% + + + + align:start position:0% + +adaptive you know if you want it's been + + align:start position:0% +adaptive you know if you want it's been + + + align:start position:0% +adaptive you know if you want it's been +used to control predation of + + align:start position:0% +used to control predation of + + + align:start position:0% +used to control predation of +livestock if you are having sheep being + + align:start position:0% +livestock if you are having sheep being + + + align:start position:0% +livestock if you are having sheep being +killed by wolves for + + align:start position:0% + + + + align:start position:0% + +example by usually it has to be a + + align:start position:0% +example by usually it has to be a + + + align:start position:0% +example by usually it has to be a +particular wolf pack so they're all + + align:start position:0% +particular wolf pack so they're all + + + align:start position:0% +particular wolf pack so they're all +going to eat some + + align:start position:0% +going to eat some + + + align:start position:0% +going to eat some +you + + align:start position:0% + + + + align:start position:0% + +you give them a t a sheep that's been a + + align:start position:0% +you give them a t a sheep that's been a + + + align:start position:0% +you give them a t a sheep that's been a +lamb or something that's been + + align:start position:0% +lamb or something that's been + + + align:start position:0% +lamb or something that's been +tainted okay or calves or you know the + + align:start position:0% +tainted okay or calves or you know the + + + align:start position:0% +tainted okay or calves or you know the +kind of thing that they're + + align:start position:0% + + + + align:start position:0% + +eating and + + align:start position:0% +eating and + + + align:start position:0% +eating and +uh they will avoid it for quite some + + align:start position:0% +uh they will avoid it for quite some + + + align:start position:0% +uh they will avoid it for quite some +time it's somewhat variable in how + + align:start position:0% +time it's somewhat variable in how + + + align:start position:0% +time it's somewhat variable in how +effective this is but of course + + align:start position:0% +effective this is but of course + + + align:start position:0% +effective this is but of course +it just how many animals actually eat it + + align:start position:0% +it just how many animals actually eat it + + + align:start position:0% +it just how many animals actually eat it +and get sick from it will vary + + align:start position:0% +and get sick from it will vary + + + align:start position:0% +and get sick from it will vary +too now that's it's related to another + + align:start position:0% +too now that's it's related to another + + + align:start position:0% +too now that's it's related to another +form of avoiding food we call + + align:start position:0% + + + + align:start position:0% + +neophobia + + align:start position:0% +neophobia + + + align:start position:0% +neophobia +animals tend to avoid new things so you + + align:start position:0% +animals tend to avoid new things so you + + + align:start position:0% +animals tend to avoid new things so you +you set up trap for a mouse or a rat in + + align:start position:0% +you set up trap for a mouse or a rat in + + + align:start position:0% +you set up trap for a mouse or a rat in +your + + align:start position:0% +your + + + align:start position:0% +your +house um if it's not something really + + align:start position:0% +house um if it's not something really + + + align:start position:0% +house um if it's not something really +familiar to the animal they will be very + + align:start position:0% +familiar to the animal they will be very + + + align:start position:0% +familiar to the animal they will be very +very + + align:start position:0% +very + + + align:start position:0% +very +cautious you know it needs to be + + align:start position:0% +cautious you know it needs to be + + + align:start position:0% +cautious you know it needs to be +something that they really love and has + + align:start position:0% +something that they really love and has + + + align:start position:0% +something that they really love and has +a strong odor certain kinds of cheese + + align:start position:0% +a strong odor certain kinds of cheese + + + align:start position:0% +a strong odor certain kinds of cheese +have that effect and uh + + align:start position:0% + + + + align:start position:0% + +sorry well I + + align:start position:0% +sorry well I + + + align:start position:0% +sorry well I +hope I hope that will + + align:start position:0% + + + + align:start position:0% + +wait okay + + align:start position:0% +wait okay + + + align:start position:0% +wait okay +so you why would they avoid something + + align:start position:0% +so you why would they avoid something + + + align:start position:0% +so you why would they avoid something +novel well it's not as likely to be safe + + align:start position:0% +novel well it's not as likely to be safe + + + align:start position:0% +novel well it's not as likely to be safe +you know they know what's safe they've + + align:start position:0% +you know they know what's safe they've + + + align:start position:0% +you know they know what's safe they've +had experience with + + align:start position:0% +had experience with + + + align:start position:0% +had experience with +it how would you expect that effect to + + align:start position:0% +it how would you expect that effect to + + + align:start position:0% +it how would you expect that effect to +vary with those two factors hunger level + + align:start position:0% +vary with those two factors hunger level + + + align:start position:0% +vary with those two factors hunger level +and + + align:start position:0% +and + + + align:start position:0% +and +age would it be greater or less in a + + align:start position:0% +age would it be greater or less in a + + + align:start position:0% +age would it be greater or less in a +young rat or an old + + align:start position:0% +young rat or an old + + + align:start position:0% +young rat or an old +rat you might say well an inex + + align:start position:0% +rat you might say well an inex + + + align:start position:0% +rat you might say well an inex +experience rat he's more likely to eat + + align:start position:0% +experience rat he's more likely to eat + + + align:start position:0% +experience rat he's more likely to eat +anything but in fact it's the reverse + + align:start position:0% +anything but in fact it's the reverse + + + align:start position:0% +anything but in fact it's the reverse +the young T you should know with + + align:start position:0% +the young T you should know with + + + align:start position:0% +the young T you should know with +humans uh when you were younger you were + + align:start position:0% +humans uh when you were younger you were + + + align:start position:0% +humans uh when you were younger you were +probably much more likely to avoid a lot + + align:start position:0% +probably much more likely to avoid a lot + + + align:start position:0% +probably much more likely to avoid a lot +of things and your parents are always + + align:start position:0% +of things and your parents are always + + + align:start position:0% +of things and your parents are always +trying to get you to try new things + + align:start position:0% +trying to get you to try new things + + + align:start position:0% +trying to get you to try new things +right and you say I don't like it um + + align:start position:0% +right and you say I don't like it um + + + align:start position:0% +right and you say I don't like it um +my uh youngest daughter would say I + + align:start position:0% +my uh youngest daughter would say I + + + align:start position:0% +my uh youngest daughter would say I +don't like that stuff and she's never + + align:start position:0% +don't like that stuff and she's never + + + align:start position:0% +don't like that stuff and she's never +had it in her life + + align:start position:0% +had it in her life + + + align:start position:0% +had it in her life +I knew that because she'd come here from + + align:start position:0% +I knew that because she'd come here from + + + align:start position:0% +I knew that because she'd come here from +China so she had never had any of the + + align:start position:0% +China so she had never had any of the + + + align:start position:0% +China so she had never had any of the +American foods we were having but her + + align:start position:0% +American foods we were having but her + + + align:start position:0% +American foods we were having but her +mother much older of course would try it + + align:start position:0% +mother much older of course would try it + + + align:start position:0% +mother much older of course would try it +and like it and so forth but you know as + + align:start position:0% +and like it and so forth but you know as + + + align:start position:0% +and like it and so forth but you know as +the daughter grows older she gradually + + align:start position:0% +the daughter grows older she gradually + + + align:start position:0% +the daughter grows older she gradually +will try more and more things but if you + + align:start position:0% +will try more and more things but if you + + + align:start position:0% +will try more and more things but if you +make them as I pointed out before if + + align:start position:0% +make them as I pointed out before if + + + align:start position:0% +make them as I pointed out before if +they're hungry enough neophobia + + align:start position:0% +they're hungry enough neophobia + + + align:start position:0% +they're hungry enough neophobia +decreases and again of course that's + + align:start position:0% +decreases and again of course that's + + + align:start position:0% +decreases and again of course that's +adaptive + + align:start position:0% +adaptive + + + align:start position:0% +adaptive +because they don't an animal doesn't + + align:start position:0% +because they don't an animal doesn't + + + align:start position:0% +because they don't an animal doesn't +want to starve to death so they have an + + align:start position:0% +want to starve to death so they have an + + + align:start position:0% +want to starve to death so they have an +these are innate preferences though that + + align:start position:0% +these are innate preferences though that + + + align:start position:0% +these are innate preferences though that +we're talking about + + align:start position:0% + + + + align:start position:0% + +okay and + + align:start position:0% +okay and + + + align:start position:0% +okay and +then Scott discusses another situation + + align:start position:0% +then Scott discusses another situation + + + align:start position:0% +then Scott discusses another situation +of social facilitation in this case in + + align:start position:0% +of social facilitation in this case in + + + align:start position:0% +of social facilitation in this case in +capuchin monkeys based with a novel food + + align:start position:0% +capuchin monkeys based with a novel food + + + align:start position:0% +capuchin monkeys based with a novel food +they discovered that the + + align:start position:0% +they discovered that the + + + align:start position:0% +they discovered that the +monkey was much more likely to eat that + + align:start position:0% +monkey was much more likely to eat that + + + align:start position:0% +monkey was much more likely to eat that +novel food in if other monkeys were + + align:start position:0% +novel food in if other monkeys were + + + align:start position:0% +novel food in if other monkeys were +eating near him and it didn't even have + + align:start position:0% +eating near him and it didn't even have + + + align:start position:0% +eating near him and it didn't even have +to be the same food which was the + + align:start position:0% +to be the same food which was the + + + align:start position:0% +to be the same food which was the +surprising part of the study it would be + + align:start position:0% +surprising part of the study it would be + + + align:start position:0% +surprising part of the study it would be +understandable if you saw other animals + + align:start position:0% +understandable if you saw other animals + + + align:start position:0% +understandable if you saw other animals +eating it it was the same thing oh + + align:start position:0% +eating it it was the same thing oh + + + align:start position:0% +eating it it was the same thing oh +that's got to be safe you know they're + + align:start position:0% +that's got to be safe you know they're + + + align:start position:0% +that's got to be safe you know they're +eating it it's not going to hurt me uh + + align:start position:0% +eating it it's not going to hurt me uh + + + align:start position:0% +eating it it's not going to hurt me uh +but they'll do it even they'll they're + + align:start position:0% +but they'll do it even they'll they're + + + align:start position:0% +but they'll do it even they'll they're +more likely to eat the novel food even + + align:start position:0% +more likely to eat the novel food even + + + align:start position:0% +more likely to eat the novel food even +if the monkeys are eating something more + + align:start position:0% +if the monkeys are eating something more + + + align:start position:0% +if the monkeys are eating something more +familiar + + align:start position:0% +familiar + + + align:start position:0% +familiar +and I I can't really explain that in + + align:start position:0% +and I I can't really explain that in + + + align:start position:0% +and I I can't really explain that in +terms of adaptive + + align:start position:0% +terms of adaptive + + + align:start position:0% +terms of adaptive +Behavior okay let's talk about another + + align:start position:0% +Behavior okay let's talk about another + + + align:start position:0% +Behavior okay let's talk about another +social effect on the + + align:start position:0% +social effect on the + + + align:start position:0% +social effect on the +foraging the the ospr an a bird that uh + + align:start position:0% +foraging the the ospr an a bird that uh + + + align:start position:0% +foraging the the ospr an a bird that uh +forages for fish in the + + align:start position:0% +forages for fish in the + + + align:start position:0% +forages for fish in the +ocean uh how can they benefit from + + align:start position:0% +ocean uh how can they benefit from + + + align:start position:0% +ocean uh how can they benefit from +hunting that is fishing success of + + align:start position:0% +hunting that is fishing success of + + + align:start position:0% +hunting that is fishing success of +neighbors even even though they don't + + align:start position:0% +neighbors even even though they don't + + + align:start position:0% +neighbors even even though they don't +share the the ospry that brings a fish + + align:start position:0% +share the the ospry that brings a fish + + + align:start position:0% +share the the ospry that brings a fish +back to their communal Colony um doesn't + + align:start position:0% +back to their communal Colony um doesn't + + + align:start position:0% +back to their communal Colony um doesn't +share it with the others and yet it will + + align:start position:0% +share it with the others and yet it will + + + align:start position:0% +share it with the others and yet it will +affect the + + align:start position:0% +affect the + + + align:start position:0% +affect the +others because the and this there you + + align:start position:0% +others because the and this there you + + + align:start position:0% +others because the and this there you +there are some data put in the chapter + + align:start position:0% +there are some data put in the chapter + + + align:start position:0% +there are some data put in the chapter +there Scott's chapter he presents some + + align:start position:0% +there Scott's chapter he presents some + + + align:start position:0% +there Scott's chapter he presents some +data that animals the frequency that + + align:start position:0% +data that animals the frequency that + + + align:start position:0% +data that animals the frequency that +they fly off in the same direction great + + align:start position:0% +they fly off in the same direction great + + + align:start position:0% +they fly off in the same direction great +increases if a Osprey has brought back + + align:start position:0% +increases if a Osprey has brought back + + + align:start position:0% +increases if a Osprey has brought back +certain kinds of fish but not all kinds + + align:start position:0% +certain kinds of fish but not all kinds + + + align:start position:0% +certain kinds of fish but not all kinds +of + + align:start position:0% +of + + + align:start position:0% +of +fish why does it depend on the kind of + + align:start position:0% +fish why does it depend on the kind of + + + align:start position:0% +fish why does it depend on the kind of +fish can you think you know even if + + align:start position:0% +fish can you think you know even if + + + align:start position:0% +fish can you think you know even if +you've not read it you should be able to + + align:start position:0% +you've not read it you should be able to + + + align:start position:0% +you've not read it you should be able to +think of some reason why it might have + + align:start position:0% +think of some reason why it might have + + + align:start position:0% +think of some reason why it might have +evolve that + + align:start position:0% + + + + align:start position:0% + +way because fish differ in How likely + + align:start position:0% +way because fish differ in How likely + + + align:start position:0% +way because fish differ in How likely +they are to be swimming in + + align:start position:0% +they are to be swimming in + + + align:start position:0% +they are to be swimming in +schools if the fish aren't schooling + + align:start position:0% +schools if the fish aren't schooling + + + align:start position:0% +schools if the fish aren't schooling +fish like the Alewife for example in the + + align:start position:0% +fish like the Alewife for example in the + + + align:start position:0% +fish like the Alewife for example in the +oceans out here if they tend to be + + align:start position:0% +oceans out here if they tend to be + + + align:start position:0% +oceans out here if they tend to be +schooling + + align:start position:0% +schooling + + + align:start position:0% +schooling +fish + + align:start position:0% +fish + + + align:start position:0% +fish +but flounders are + + align:start position:0% +but flounders are + + + align:start position:0% +but flounders are +not in schools so if the if the ospry + + align:start position:0% +not in schools so if the if the ospry + + + align:start position:0% +not in schools so if the if the ospry +comes back with a flounder the other + + align:start position:0% +comes back with a flounder the other + + + align:start position:0% +comes back with a flounder the other +birds will ignore it you know that + + align:start position:0% +birds will ignore it you know that + + + align:start position:0% +birds will ignore it you know that +they'll just consider that bird a lucky + + align:start position:0% +they'll just consider that bird a lucky + + + align:start position:0% +they'll just consider that bird a lucky +bird but it's not going to affect them + + align:start position:0% +bird but it's not going to affect them + + + align:start position:0% +bird but it's not going to affect them +but if it was a one of these birds uh + + align:start position:0% +but if it was a one of these birds uh + + + align:start position:0% +but if it was a one of these birds uh +they he doesn't mention Herring but + + align:start position:0% +they he doesn't mention Herring but + + + align:start position:0% +they he doesn't mention Herring but +Herring are another schooling fish you + + align:start position:0% +Herring are another schooling fish you + + + align:start position:0% +Herring are another schooling fish you +know if so if it was a fish like + + align:start position:0% +know if so if it was a fish like + + + align:start position:0% +know if so if it was a fish like +that then he's much more likely to fly + + align:start position:0% +that then he's much more likely to fly + + + align:start position:0% +that then he's much more likely to fly +up in that direction because he knows + + align:start position:0% +up in that direction because he knows + + + align:start position:0% +up in that direction because he knows +there's got to be a school school of + + align:start position:0% +there's got to be a school school of + + + align:start position:0% +there's got to be a school school of +them out there or this bird wouldn't + + align:start position:0% +them out there or this bird wouldn't + + + align:start position:0% +them out there or this bird wouldn't +have come back with a + + align:start position:0% +have come back with a + + + align:start position:0% +have come back with a +fish so that gives them some benefit + + align:start position:0% +fish so that gives them some benefit + + + align:start position:0% +fish so that gives them some benefit +for living in a colony so it Ser serves + + align:start position:0% +for living in a colony so it Ser serves + + + align:start position:0% +for living in a colony so it Ser serves +as a kind of center of information + + align:start position:0% + + + + align:start position:0% + +transfer they've looked for the same + + align:start position:0% +transfer they've looked for the same + + + align:start position:0% +transfer they've looked for the same +thing with blackheaded gulls which also + + align:start position:0% +thing with blackheaded gulls which also + + + align:start position:0% +thing with blackheaded gulls which also +uh Nest near uh near each other and yet + + align:start position:0% +uh Nest near uh near each other and yet + + + align:start position:0% +uh Nest near uh near each other and yet +they don't respond that way even if a + + align:start position:0% +they don't respond that way even if a + + + align:start position:0% +they don't respond that way even if a +blackheaded gull's coming back from a + + align:start position:0% +blackheaded gull's coming back from a + + + align:start position:0% +blackheaded gull's coming back from a +pile of food so there's a lot of it + + align:start position:0% +pile of food so there's a lot of it + + + align:start position:0% +pile of food so there's a lot of it +available the others won't fly up in + + align:start position:0% +available the others won't fly up in + + + align:start position:0% +available the others won't fly up in +that direction so the question is why + + align:start position:0% +that direction so the question is why + + + align:start position:0% +that direction so the question is why +are they different you know I have in my + + align:start position:0% +are they different you know I have in my + + + align:start position:0% +are they different you know I have in my +I having the margin of this book which + + align:start position:0% +I having the margin of this book which + + + align:start position:0% +I having the margin of this book which +I've had for several years uh you know + + align:start position:0% +I've had for several years uh you know + + + align:start position:0% +I've had for several years uh you know +blackheaded are stupid in comparison to + + align:start position:0% +blackheaded are stupid in comparison to + + + align:start position:0% +blackheaded are stupid in comparison to +ospr but in fact there is a reason why + + align:start position:0% +ospr but in fact there is a reason why + + + align:start position:0% +ospr but in fact there is a reason why +they might have evolved that way at + + align:start position:0% +they might have evolved that way at + + + align:start position:0% +they might have evolved that way at +least earlier in their evolution they + + align:start position:0% +least earlier in their evolution they + + + align:start position:0% +least earlier in their evolution they +probably fed mainly on food that was + + align:start position:0% +probably fed mainly on food that was + + + align:start position:0% +probably fed mainly on food that was +scattered okay so not likely to be found + + align:start position:0% +scattered okay so not likely to be found + + + align:start position:0% +scattered okay so not likely to be found +so they'd be wasting energy if they + + align:start position:0% +so they'd be wasting energy if they + + + align:start position:0% +so they'd be wasting energy if they +constantly flew off in the + + align:start position:0% +constantly flew off in the + + + align:start position:0% +constantly flew off in the +direction of that an animal had come + + align:start position:0% +direction of that an animal had come + + + align:start position:0% +direction of that an animal had come +from just because he had food just + + align:start position:0% +from just because he had food just + + + align:start position:0% +from just because he had food just +because of different + + align:start position:0% +because of different + + + align:start position:0% +because of different +feeding preferences at least in for a + + align:start position:0% +feeding preferences at least in for a + + + align:start position:0% +feeding preferences at least in for a +long period in their evolution so + + align:start position:0% +long period in their evolution so + + + align:start position:0% +long period in their evolution so +they've evolved different differently + + align:start position:0% +they've evolved different differently + + + align:start position:0% +they've evolved different differently +from the + + align:start position:0% + + + + align:start position:0% + +ospr okay group + + align:start position:0% +ospr okay group + + + align:start position:0% +ospr okay group +foraging I want two good reasons why + + align:start position:0% +foraging I want two good reasons why + + + align:start position:0% +foraging I want two good reasons why +foraging in a group of herbivores may be + + align:start position:0% +foraging in a group of herbivores may be + + + align:start position:0% +foraging in a group of herbivores may be +better for an animal like a bird than + + align:start position:0% +better for an animal like a bird than + + + align:start position:0% +better for an animal like a bird than +foraging + + align:start position:0% + + + + align:start position:0% + +alone and I can give you a hint pay + + align:start position:0% +alone and I can give you a hint pay + + + align:start position:0% +alone and I can give you a hint pay +attention to birds right now you ever + + align:start position:0% +attention to birds right now you ever + + + align:start position:0% +attention to birds right now you ever +look at birds outside you will notice + + align:start position:0% +look at birds outside you will notice + + + align:start position:0% +look at birds outside you will notice +something happening as as the fall goes + + align:start position:0% +something happening as as the fall goes + + + align:start position:0% +something happening as as the fall goes +on food is still fairly plentiful but it + + align:start position:0% +on food is still fairly plentiful but it + + + align:start position:0% +on food is still fairly plentiful but it +becomes less and less as the winter + + align:start position:0% +becomes less and less as the winter + + + align:start position:0% +becomes less and less as the winter +approaches and when snows on the ground + + align:start position:0% +approaches and when snows on the ground + + + align:start position:0% +approaches and when snows on the ground +it becomes much harder to find so what + + align:start position:0% +it becomes much harder to find so what + + + align:start position:0% +it becomes much harder to find so what +what change do you see in birds birds + + align:start position:0% +what change do you see in birds birds + + + align:start position:0% +what change do you see in birds birds +that you normally never see in groups in + + align:start position:0% +that you normally never see in groups in + + + align:start position:0% +that you normally never see in groups in +flocks start + + align:start position:0% +flocks start + + + align:start position:0% +flocks start +flocking it looks like they're all just + + align:start position:0% +flocking it looks like they're all just + + + align:start position:0% +flocking it looks like they're all just +flocking because they're oh they're + + align:start position:0% +flocking because they're oh they're + + + align:start position:0% +flocking because they're oh they're +going to fly south together but in fact + + align:start position:0% +going to fly south together but in fact + + + align:start position:0% +going to fly south together but in fact +in many cases that's not the reason + + align:start position:0% +in many cases that's not the reason + + + align:start position:0% +in many cases that's not the reason +you'll see sparrows doing this you'll + + align:start position:0% +you'll see sparrows doing this you'll + + + align:start position:0% +you'll see sparrows doing this you'll +see you know junos doing this they they + + align:start position:0% +see you know junos doing this they they + + + align:start position:0% +see you know junos doing this they they +all stay around here all winter so why + + align:start position:0% +all stay around here all winter so why + + + align:start position:0% +all stay around here all winter so why +would they do that what are the + + align:start position:0% +would they do that what are the + + + align:start position:0% +would they do that what are the +benefits first of all protection from + + align:start position:0% +benefits first of all protection from + + + align:start position:0% +benefits first of all protection from +predators because when there's a lot + + align:start position:0% +predators because when there's a lot + + + align:start position:0% +predators because when there's a lot +more eyes you know the Predators have + + align:start position:0% +more eyes you know the Predators have + + + align:start position:0% +more eyes you know the Predators have +finding less food + + align:start position:0% +finding less food + + + align:start position:0% +finding less food +too so they're going to be hunting these + + align:start position:0% +too so they're going to be hunting these + + + align:start position:0% +too so they're going to be hunting these +Hawks the red tail hawks around here + + align:start position:0% +Hawks the red tail hawks around here + + + align:start position:0% +Hawks the red tail hawks around here +certainly catch they catch p they prefer + + align:start position:0% +certainly catch they catch p they prefer + + + align:start position:0% +certainly catch they catch p they prefer +those CU they're bigger and fatter but + + align:start position:0% +those CU they're bigger and fatter but + + + align:start position:0% +those CU they're bigger and fatter but +they will they'll catch song birds + + align:start position:0% +they will they'll catch song birds + + + align:start position:0% +they will they'll catch song birds +too uh so the Predator is more likely to + + align:start position:0% +too uh so the Predator is more likely to + + + align:start position:0% +too uh so the Predator is more likely to +be detected if there's a lot more eyes + + align:start position:0% +be detected if there's a lot more eyes + + + align:start position:0% +be detected if there's a lot more eyes +that could see them and also if they're + + align:start position:0% +that could see them and also if they're + + + align:start position:0% +that could see them and also if they're +in a + + align:start position:0% +in a + + + align:start position:0% +in a +group and there's a red tail hawk + + align:start position:0% +group and there's a red tail hawk + + + align:start position:0% +group and there's a red tail hawk +attacking they're only one in a group so + + align:start position:0% +attacking they're only one in a group so + + + align:start position:0% +attacking they're only one in a group so +the chances that they'll be the one the + + align:start position:0% +the chances that they'll be the one the + + + align:start position:0% +the chances that they'll be the one the +hawk selects are reduced that's a kind + + align:start position:0% +hawk selects are reduced that's a kind + + + align:start position:0% +hawk selects are reduced that's a kind +of delution effect that protects animals + + align:start position:0% +of delution effect that protects animals + + + align:start position:0% +of delution effect that protects animals +in a + + align:start position:0% +in a + + + align:start position:0% +in a +group + + align:start position:0% +group + + + align:start position:0% +group +well in + + align:start position:0% +well in + + + align:start position:0% +well in +addition we mention the uh oh I should + + align:start position:0% +addition we mention the uh oh I should + + + align:start position:0% +addition we mention the uh oh I should +the second one of course is they're more + + align:start position:0% +the second one of course is they're more + + + align:start position:0% +the second one of course is they're more +likely to detect food sources for the + + align:start position:0% +likely to detect food sources for the + + + align:start position:0% +likely to detect food sources for the +same reason that they're more likely to + + align:start position:0% +same reason that they're more likely to + + + align:start position:0% +same reason that they're more likely to +detect a + + align:start position:0% +detect a + + + align:start position:0% +detect a +predator it's very interesting watching + + align:start position:0% +predator it's very interesting watching + + + align:start position:0% +predator it's very interesting watching +a large group of birds are doing this + + align:start position:0% +a large group of birds are doing this + + + align:start position:0% +a large group of birds are doing this +all it takes is one seeing the food and + + align:start position:0% +all it takes is one seeing the food and + + + align:start position:0% +all it takes is one seeing the food and +he flies off separate from the others + + align:start position:0% +he flies off separate from the others + + + align:start position:0% +he flies off separate from the others +almost always the entire group almost + + align:start position:0% +almost always the entire group almost + + + align:start position:0% +almost always the entire group almost +immediately is with him and flies + + align:start position:0% + + + + align:start position:0% + +down and of course social facilitation + + align:start position:0% +down and of course social facilitation + + + align:start position:0% +down and of course social facilitation +does increase their food consumption + + align:start position:0% +does increase their food consumption + + + align:start position:0% +does increase their food consumption +condition this is just example of group + + align:start position:0% +condition this is just example of group + + + align:start position:0% +condition this is just example of group +foraging here's Pelicans foraging in + + align:start position:0% +foraging here's Pelicans foraging in + + + align:start position:0% +foraging here's Pelicans foraging in +groups the groups they tend to be uh a + + align:start position:0% +groups the groups they tend to be uh a + + + align:start position:0% +groups the groups they tend to be uh a +little smaller here's the American white + + align:start position:0% +little smaller here's the American white + + + align:start position:0% +little smaller here's the American white +pelican one foraging group uh + + align:start position:0% +pelican one foraging group uh + + + align:start position:0% +pelican one foraging group uh +does the same reasoning apply to + + align:start position:0% +does the same reasoning apply to + + + align:start position:0% +does the same reasoning apply to +carnivores in their hunting + + align:start position:0% +carnivores in their hunting + + + align:start position:0% +carnivores in their hunting +Behavior well some of the same reasons + + align:start position:0% +Behavior well some of the same reasons + + + align:start position:0% +Behavior well some of the same reasons +apply they have increased likelihood of + + align:start position:0% +apply they have increased likelihood of + + + align:start position:0% +apply they have increased likelihood of +finding prey they have increased + + align:start position:0% +finding prey they have increased + + + align:start position:0% +finding prey they have increased +likelihood of catching them because of + + align:start position:0% +likelihood of catching them because of + + + align:start position:0% +likelihood of catching them because of +Cooperative hunting strategies and these + + align:start position:0% +Cooperative hunting strategies and these + + + align:start position:0% +Cooperative hunting strategies and these +are examples I can think of uh all these + + align:start position:0% +are examples I can think of uh all these + + + align:start position:0% +are examples I can think of uh all these +animals have been studied and their + + align:start position:0% +animals have been studied and their + + + align:start position:0% +animals have been studied and their +hunting behaviors has been studying we + + align:start position:0% +hunting behaviors has been studying we + + + align:start position:0% +hunting behaviors has been studying we +know that lions or at least lionist + + align:start position:0% +know that lions or at least lionist + + + align:start position:0% +know that lions or at least lionist +hunt in groups wolves certainly do uh + + align:start position:0% +hunt in groups wolves certainly do uh + + + align:start position:0% +hunt in groups wolves certainly do uh +though the groups vary a lot in + + align:start position:0% +though the groups vary a lot in + + + align:start position:0% +though the groups vary a lot in +size the wild dogs the African wild dogs + + align:start position:0% +size the wild dogs the African wild dogs + + + align:start position:0% +size the wild dogs the African wild dogs +always hunt in + + align:start position:0% +always hunt in + + + align:start position:0% +always hunt in +groups U you find some of that in hyenas + + align:start position:0% +groups U you find some of that in hyenas + + + align:start position:0% +groups U you find some of that in hyenas +as well um and then in the sea mammals + + align:start position:0% +as well um and then in the sea mammals + + + align:start position:0% +as well um and then in the sea mammals +the killer whales the orcas hunt that + + align:start position:0% +the killer whales the orcas hunt that + + + align:start position:0% +the killer whales the orcas hunt that +way uh and even humpback whales engage + + align:start position:0% +way uh and even humpback whales engage + + + align:start position:0% +way uh and even humpback whales engage +in uh cooperation in their catching of + + align:start position:0% +in uh cooperation in their catching of + + + align:start position:0% +in uh cooperation in their catching of +pray like they trap herring fish one of + + align:start position:0% +pray like they trap herring fish one of + + + align:start position:0% +pray like they trap herring fish one of +them goes below and emits a string of + + align:start position:0% +them goes below and emits a string of + + + align:start position:0% +them goes below and emits a string of +Bubbles and the bubbles rise up and form + + align:start position:0% +Bubbles and the bubbles rise up and form + + + align:start position:0% +Bubbles and the bubbles rise up and form +a kind of cylinder around the Herring up + + align:start position:0% +a kind of cylinder around the Herring up + + + align:start position:0% +a kind of cylinder around the Herring up +above and they Herring of course could + + align:start position:0% +above and they Herring of course could + + + align:start position:0% +above and they Herring of course could +swim right through that but they don't + + align:start position:0% +swim right through that but they don't + + + align:start position:0% +swim right through that but they don't +they avoid the bubbles so they they sort + + align:start position:0% +they avoid the bubbles so they they sort + + + align:start position:0% +they avoid the bubbles so they they sort +of trap them in there and the the the + + align:start position:0% +of trap them in there and the the the + + + align:start position:0% +of trap them in there and the the the +humpback whales up above then can feed + + align:start position:0% +humpback whales up above then can feed + + + align:start position:0% +humpback whales up above then can feed +on + + align:start position:0% +on + + + align:start position:0% +on +Herring so it's a Cooperative hunting + + align:start position:0% +Herring so it's a Cooperative hunting + + + align:start position:0% +Herring so it's a Cooperative hunting +strategy they obviously have to take + + align:start position:0% +strategy they obviously have to take + + + align:start position:0% +strategy they obviously have to take +turns being the one that creates the + + align:start position:0% +turns being the one that creates the + + + align:start position:0% +turns being the one that creates the +bubbles because they're getting much + + align:start position:0% +bubbles because they're getting much + + + align:start position:0% +bubbles because they're getting much +less + + align:start position:0% +less + + + align:start position:0% +less +food this is just examples there you see + + align:start position:0% +food this is just examples there you see + + + align:start position:0% +food this is just examples there you see +a bunch of uh + + align:start position:0% +a bunch of uh + + + align:start position:0% +a bunch of uh +um female lions the lionesses and there + + align:start position:0% +um female lions the lionesses and there + + + align:start position:0% +um female lions the lionesses and there +you see below their uh a group attack on + + align:start position:0% +you see below their uh a group attack on + + + align:start position:0% +you see below their uh a group attack on +a on a buffalo and they would have very + + align:start position:0% +a on a buffalo and they would have very + + + align:start position:0% +a on a buffalo and they would have very +little chance of bringing that Buffalo + + align:start position:0% +little chance of bringing that Buffalo + + + align:start position:0% +little chance of bringing that Buffalo +down if just one of them were doing it + + align:start position:0% +down if just one of them were doing it + + + align:start position:0% +down if just one of them were doing it +it would take at least two and the more + + align:start position:0% +it would take at least two and the more + + + align:start position:0% +it would take at least two and the more +there are the more likely they are to + + align:start position:0% +there are the more likely they are to + + + align:start position:0% +there are the more likely they are to +bring it down + + align:start position:0% +bring it down + + + align:start position:0% +bring it down +u i put this in just so I can point out + + align:start position:0% +u i put this in just so I can point out + + + align:start position:0% +u i put this in just so I can point out +that just because they're in a group + + align:start position:0% +that just because they're in a group + + + align:start position:0% +that just because they're in a group +they will not always attack I mean what + + align:start position:0% +they will not always attack I mean what + + + align:start position:0% +they will not always attack I mean what +is the + + align:start position:0% +is the + + + align:start position:0% +is the +likelihood that even three liones could + + align:start position:0% +likelihood that even three liones could + + + align:start position:0% +likelihood that even three liones could +bring down that + + align:start position:0% +bring down that + + + align:start position:0% +bring down that +rhinoceros for one thing the rhinoceros + + align:start position:0% +rhinoceros for one thing the rhinoceros + + + align:start position:0% +rhinoceros for one thing the rhinoceros +can run pretty fast and the other is the + + align:start position:0% +can run pretty fast and the other is the + + + align:start position:0% +can run pretty fast and the other is the +likelihood that he would Gore at least + + align:start position:0% +likelihood that he would Gore at least + + + align:start position:0% +likelihood that he would Gore at least +one of them and maybe all of them are + + align:start position:0% +one of them and maybe all of them are + + + align:start position:0% +one of them and maybe all of them are +very + + align:start position:0% +very + + + align:start position:0% +very +high and they can't afford a severe + + align:start position:0% +high and they can't afford a severe + + + align:start position:0% +high and they can't afford a severe +injury you know they + + align:start position:0% +injury you know they + + + align:start position:0% +injury you know they +don't they don't have lionist doctors + + align:start position:0% +don't they don't have lionist doctors + + + align:start position:0% +don't they don't have lionist doctors +you know so they will simply watch + + align:start position:0% +you know so they will simply watch + + + align:start position:0% +you know so they will simply watch +animals like this they have to make the + + align:start position:0% +animals like this they have to make the + + + align:start position:0% +animals like this they have to make the +decision you know is it worth it what's + + align:start position:0% +decision you know is it worth it what's + + + align:start position:0% +decision you know is it worth it what's +the cost if they're super hungry yes + + align:start position:0% +the cost if they're super hungry yes + + + align:start position:0% +the cost if they're super hungry yes +they will attack even animals like + + align:start position:0% +they will attack even animals like + + + align:start position:0% +they will attack even animals like +this here's a group of wolves uh one + + align:start position:0% +this here's a group of wolves uh one + + + align:start position:0% +this here's a group of wolves uh one +wolf can never bring down on a + + align:start position:0% +wolf can never bring down on a + + + align:start position:0% +wolf can never bring down on a +buffalo you know the buffalo's too big + + align:start position:0% +buffalo you know the buffalo's too big + + + align:start position:0% +buffalo you know the buffalo's too big +and strong he can kick very hard with + + align:start position:0% +and strong he can kick very hard with + + + align:start position:0% +and strong he can kick very hard with +those Hoopes but with multiple + + align:start position:0% +those Hoopes but with multiple + + + align:start position:0% +those Hoopes but with multiple +wolves and they often precede this by + + align:start position:0% +wolves and they often precede this by + + + align:start position:0% +wolves and they often precede this by +running chasing the animal for a long + + align:start position:0% +running chasing the animal for a long + + + align:start position:0% +running chasing the animal for a long +distance so they Tire him out and that + + align:start position:0% +distance so they Tire him out and that + + + align:start position:0% +distance so they Tire him out and that +makes him less able to fight them off + + align:start position:0% +makes him less able to fight them off + + + align:start position:0% +makes him less able to fight them off +when they finally attack him so it does + + align:start position:0% +when they finally attack him so it does + + + align:start position:0% +when they finally attack him so it does +take a a wolf pack like this this is a + + align:start position:0% +take a a wolf pack like this this is a + + + align:start position:0% +take a a wolf pack like this this is a +fairly large pack to bring a buffalo + + align:start position:0% +fairly large pack to bring a buffalo + + + align:start position:0% +fairly large pack to bring a buffalo +down and here's the African wild dogs + + align:start position:0% +down and here's the African wild dogs + + + align:start position:0% +down and here's the African wild dogs +you see how relatively small they are + + align:start position:0% +you see how relatively small they are + + + align:start position:0% +you see how relatively small they are +compared to that zebra but again and dog + + align:start position:0% +compared to that zebra but again and dog + + + align:start position:0% +compared to that zebra but again and dog +these dogs are well known for singling + + align:start position:0% +these dogs are well known for singling + + + align:start position:0% +these dogs are well known for singling +out the weaker ones and then chasing + + align:start position:0% +out the weaker ones and then chasing + + + align:start position:0% +out the weaker ones and then chasing +them for very long distance they have + + align:start position:0% +them for very long distance they have + + + align:start position:0% +them for very long distance they have +great stamina and they take turns being + + align:start position:0% +great stamina and they take turns being + + + align:start position:0% +great stamina and they take turns being +the ones closes to the the + + align:start position:0% +the ones closes to the the + + + align:start position:0% +the ones closes to the the +zebra so which takes a little more + + align:start position:0% +zebra so which takes a little more + + + align:start position:0% +zebra so which takes a little more +energy so so they take turns doing that + + align:start position:0% +energy so so they take turns doing that + + + align:start position:0% +energy so so they take turns doing that +until finally they exhaust the animal + + align:start position:0% +until finally they exhaust the animal + + + align:start position:0% +until finally they exhaust the animal +and then in spite of their small size + + align:start position:0% +and then in spite of their small size + + + align:start position:0% +and then in spite of their small size +they can uh they can kill an animal like + + align:start position:0% +they can uh they can kill an animal like + + + align:start position:0% +they can uh they can kill an animal like +this you can see the zebra + + align:start position:0% +this you can see the zebra + + + align:start position:0% +this you can see the zebra +there he will kick out at them if they + + align:start position:0% +there he will kick out at them if they + + + align:start position:0% +there he will kick out at them if they +get to close to him and the dogs are + + align:start position:0% +get to close to him and the dogs are + + + align:start position:0% +get to close to him and the dogs are +patient they just run him down until he + + align:start position:0% +patient they just run him down until he + + + align:start position:0% +patient they just run him down until he +doesn't have the energy to do + + align:start position:0% +doesn't have the energy to do + + + align:start position:0% +doesn't have the energy to do +this and there's since two the year 2000 + + align:start position:0% +this and there's since two the year 2000 + + + align:start position:0% +this and there's since two the year 2000 +there's a number of things you can find + + align:start position:0% +there's a number of things you can find + + + align:start position:0% +there's a number of things you can find +on the web using Google scholar in find + + align:start position:0% +on the web using Google scholar in find + + + align:start position:0% +on the web using Google scholar in find +including a number of theoretical models + + align:start position:0% +including a number of theoretical models + + + align:start position:0% +including a number of theoretical models +about group uh hunting and group + + align:start position:0% +about group uh hunting and group + + + align:start position:0% +about group uh hunting and group +foraging uh one + + align:start position:0% +foraging uh one + + + align:start position:0% +foraging uh one +article + + align:start position:0% +article + + + align:start position:0% +article +uh is about Raven Scavenging which + + align:start position:0% +uh is about Raven Scavenging which + + + align:start position:0% +uh is about Raven Scavenging which +favors group foraging by + + align:start position:0% +favors group foraging by + + + align:start position:0% +favors group foraging by +Wolves why would that be true this is + + align:start position:0% +Wolves why would that be true this is + + + align:start position:0% +Wolves why would that be true this is +the + + align:start position:0% +the + + + align:start position:0% +the +article and uh here's what they're + + align:start position:0% +article and uh here's what they're + + + align:start position:0% +article and uh here's what they're +talking talking about if a wolf pack if + + align:start position:0% +talking talking about if a wolf pack if + + + align:start position:0% +talking talking about if a wolf pack if +there's only two and sometimes three in + + align:start position:0% +there's only two and sometimes three in + + + align:start position:0% +there's only two and sometimes three in +the wolf + + align:start position:0% +the wolf + + + align:start position:0% +the wolf +pack uh + + align:start position:0% +pack uh + + + align:start position:0% +pack uh +they're very very likely to be closely + + align:start position:0% +they're very very likely to be closely + + + align:start position:0% +they're very very likely to be closely +related so they're helping each other + + align:start position:0% +related so they're helping each other + + + align:start position:0% +related so they're helping each other +they're helping the genetic fitness of + + align:start position:0% +they're helping the genetic fitness of + + + align:start position:0% +they're helping the genetic fitness of +their siblings usually or their + + align:start position:0% +their siblings usually or their + + + align:start position:0% +their siblings usually or their +parents but the larger wolf packs often + + align:start position:0% +parents but the larger wolf packs often + + + align:start position:0% +parents but the larger wolf packs often +include unrelated individuals + + align:start position:0% +include unrelated individuals + + + align:start position:0% +include unrelated individuals +okay and yet they will still join + + align:start position:0% +okay and yet they will still join + + + align:start position:0% +okay and yet they will still join +unrelated individuals well join wolf + + align:start position:0% +unrelated individuals well join wolf + + + align:start position:0% +unrelated individuals well join wolf +packs and they'll be accepted so why + + align:start position:0% +packs and they'll be accepted so why + + + align:start position:0% +packs and they'll be accepted so why +would that be what would the benefit be + + align:start position:0% +would that be what would the benefit be + + + align:start position:0% +would that be what would the benefit be +because in fact you find that on average + + align:start position:0% +because in fact you find that on average + + + align:start position:0% +because in fact you find that on average +they're going to be able to hunt better + + align:start position:0% +they're going to be able to hunt better + + + align:start position:0% +they're going to be able to hunt better +and eat more food if they're not in such + + align:start position:0% +and eat more food if they're not in such + + + align:start position:0% +and eat more food if they're not in such +a large pack because after all when they + + align:start position:0% +a large pack because after all when they + + + align:start position:0% +a large pack because after all when they +bring down prey the whole pack has to + + align:start position:0% + + + + align:start position:0% + +eat and they found a + + align:start position:0% +eat and they found a + + + align:start position:0% +eat and they found a +reason they studying these wolves they + + align:start position:0% +reason they studying these wolves they + + + align:start position:0% +reason they studying these wolves they +found out that if let's say there's only + + align:start position:0% +found out that if let's say there's only + + + align:start position:0% +found out that if let's say there's only +two and they bring down food uh they it + + align:start position:0% +two and they bring down food uh they it + + + align:start position:0% +two and they bring down food uh they it +takes a long time to eat large prey and + + align:start position:0% +takes a long time to eat large prey and + + + align:start position:0% +takes a long time to eat large prey and +they lose a lot of the of the meat + + align:start position:0% +they lose a lot of the of the meat + + + align:start position:0% +they lose a lot of the of the meat +to scavengers like + + align:start position:0% +to scavengers like + + + align:start position:0% +to scavengers like +Ravens but if they're a larger group + + align:start position:0% +Ravens but if they're a larger group + + + align:start position:0% +Ravens but if they're a larger group +they lose a lot lot less there's a lot + + align:start position:0% +they lose a lot lot less there's a lot + + + align:start position:0% +they lose a lot lot less there's a lot +more wolves to pay attention to the + + align:start position:0% +more wolves to pay attention to the + + + align:start position:0% +more wolves to pay attention to the +Scavengers and drive them + + align:start position:0% +Scavengers and drive them + + + align:start position:0% +Scavengers and drive them +off and they modeled it making + + align:start position:0% +off and they modeled it making + + + align:start position:0% +off and they modeled it making +assumptions drawn from their + + align:start position:0% +assumptions drawn from their + + + align:start position:0% +assumptions drawn from their +studies and and they were able to show + + align:start position:0% +studies and and they were able to show + + + align:start position:0% +studies and and they were able to show +that this this works there is a good + + align:start position:0% +that this this works there is a good + + + align:start position:0% +that this this works there is a good +reason why they would do this uh just + + align:start position:0% +reason why they would do this uh just + + + align:start position:0% +reason why they would do this uh just +because of the Raven Scavenging so it + + align:start position:0% +because of the Raven Scavenging so it + + + align:start position:0% +because of the Raven Scavenging so it +just points out factors that you + + align:start position:0% +just points out factors that you + + + align:start position:0% +just points out factors that you +wouldn't think of + + align:start position:0% +wouldn't think of + + + align:start position:0% +wouldn't think of +ordinarily uh but in fact the computer + + align:start position:0% +ordinarily uh but in fact the computer + + + align:start position:0% +ordinarily uh but in fact the computer +models uh show that it's very likely to + + align:start position:0% +models uh show that it's very likely to + + + align:start position:0% +models uh show that it's very likely to +be true uh here was another computer + + align:start position:0% +be true uh here was another computer + + + align:start position:0% +be true uh here was another computer +model but it's relevant to something I'm + + align:start position:0% +model but it's relevant to something I'm + + + align:start position:0% +model but it's relevant to something I'm +going to bring up a little later + + align:start position:0% +going to bring up a little later + + + align:start position:0% +going to bring up a little later +so uh if you're interested in the + + align:start position:0% +so uh if you're interested in the + + + align:start position:0% +so uh if you're interested in the +modeling uh this is a good one on what + + align:start position:0% +modeling uh this is a good one on what + + + align:start position:0% +modeling uh this is a good one on what +we call the ideal predistribution how do + + align:start position:0% +we call the ideal predistribution how do + + + align:start position:0% +we call the ideal predistribution how do +animals distribute themselves when + + align:start position:0% +animals distribute themselves when + + + align:start position:0% +animals distribute themselves when +they're they're foraging in groups but + + align:start position:0% +they're they're foraging in groups but + + + align:start position:0% +they're they're foraging in groups but +groups can go to different feeding areas + + align:start position:0% +groups can go to different feeding areas + + + align:start position:0% +groups can go to different feeding areas +some of those feeding areas are very + + align:start position:0% +some of those feeding areas are very + + + align:start position:0% +some of those feeding areas are very +rich some of them are not so rich you + + align:start position:0% +rich some of them are not so rich you + + + align:start position:0% +rich some of them are not so rich you +know and yet they distribute themselves + + align:start position:0% +know and yet they distribute themselves + + + align:start position:0% +know and yet they distribute themselves +in + + align:start position:0% +in + + + align:start position:0% +in +an in an optimal way it's called the + + align:start position:0% +an in an optimal way it's called the + + + align:start position:0% +an in an optimal way it's called the +ideal free distribution if you solve it + + align:start position:0% +ideal free distribution if you solve it + + + align:start position:0% +ideal free distribution if you solve it +theoretically where they should be so + + align:start position:0% +theoretically where they should be so + + + align:start position:0% +theoretically where they should be so +we'll be talking about + + align:start position:0% +we'll be talking about + + + align:start position:0% +we'll be talking about +that uh in this one I I mentioned this + + align:start position:0% +that uh in this one I I mentioned this + + + align:start position:0% +that uh in this one I I mentioned this +briefly this was uh a model dealing with + + align:start position:0% +briefly this was uh a model dealing with + + + align:start position:0% +briefly this was uh a model dealing with +this kind of problem when they're + + align:start position:0% +this kind of problem when they're + + + align:start position:0% +this kind of problem when they're +foraging in a large group + + align:start position:0% +foraging in a large group + + + align:start position:0% +foraging in a large group +they don't actually have a clear leader + + align:start position:0% +they don't actually have a clear leader + + + align:start position:0% +they don't actually have a clear leader +they do not lead need a clear leader to + + align:start position:0% +they do not lead need a clear leader to + + + align:start position:0% +they do not lead need a clear leader to +be able to function well like if they + + align:start position:0% +be able to function well like if they + + + align:start position:0% +be able to function well like if they +detect food only one or two birds has to + + align:start position:0% +detect food only one or two birds has to + + + align:start position:0% +detect food only one or two birds has to +detect the food and yet all of the it + + align:start position:0% +detect the food and yet all of the it + + + align:start position:0% +detect the food and yet all of the it +will very rapidly be communicated to all + + align:start position:0% +will very rapidly be communicated to all + + + align:start position:0% +will very rapidly be communicated to all +of them + + align:start position:0% +of them + + + align:start position:0% +of them +okay because of the types of cues they + + align:start position:0% +okay because of the types of cues they + + + align:start position:0% +okay because of the types of cues they +need to respond to they similar things + + align:start position:0% +need to respond to they similar things + + + align:start position:0% +need to respond to they similar things +are true of migrating birds okay there + + align:start position:0% +are true of migrating birds okay there + + + align:start position:0% +are true of migrating birds okay there +often is a leader but the leader is + + align:start position:0% +often is a leader but the leader is + + + align:start position:0% +often is a leader but the leader is +often temporary it can change uh and + + align:start position:0% +often temporary it can change uh and + + + align:start position:0% +often temporary it can change uh and +they keep flying in a concerted way you + + align:start position:0% +they keep flying in a concerted way you + + + align:start position:0% +they keep flying in a concerted way you +know um even without clear leader and + + align:start position:0% +know um even without clear leader and + + + align:start position:0% +know um even without clear leader and +yet they behave in a coordinated way if + + align:start position:0% +yet they behave in a coordinated way if + + + align:start position:0% +yet they behave in a coordinated way if +they turn the whole group turns and so + + align:start position:0% +they turn the whole group turns and so + + + align:start position:0% +they turn the whole group turns and so +forth so this is about that issue and + + align:start position:0% +forth so this is about that issue and + + + align:start position:0% +forth so this is about that issue and +it's been dealt with also in simulation + + align:start position:0% + + + + align:start position:0% + +work okay what do we mean by the term + + align:start position:0% +work okay what do we mean by the term + + + align:start position:0% +work okay what do we mean by the term +optimal foraging what should a foraging + + align:start position:0% +optimal foraging what should a foraging + + + align:start position:0% +optimal foraging what should a foraging +animal be + + align:start position:0% +animal be + + + align:start position:0% +animal be +optimizing what's give me a quantitative + + align:start position:0% +optimizing what's give me a quantitative + + + align:start position:0% +optimizing what's give me a quantitative +expression he should be + + align:start position:0% +expression he should be + + + align:start position:0% +expression he should be +optimizing the amount of food taken + + align:start position:0% +optimizing the amount of food taken + + + align:start position:0% +optimizing the amount of food taken +in the net amount of food that is net no + + align:start position:0% +in the net amount of food that is net no + + + align:start position:0% +in the net amount of food that is net no +that's not fair net + + align:start position:0% +that's not fair net + + + align:start position:0% +that's not fair net +energy which is from the food he's + + align:start position:0% +energy which is from the food he's + + + align:start position:0% +energy which is from the food he's +eating but that has costs too they're + + align:start position:0% +eating but that has costs too they're + + + align:start position:0% +eating but that has costs too they're +using energy to get it so the net energy + + align:start position:0% +using energy to get it so the net energy + + + align:start position:0% +using energy to get it so the net energy +intake per unit time that's what they + + align:start position:0% +intake per unit time that's what they + + + align:start position:0% +intake per unit time that's what they +should be optimizing okay a foraging + + align:start position:0% +should be optimizing okay a foraging + + + align:start position:0% +should be optimizing okay a foraging +animal should optimize energy intake + + align:start position:0% +animal should optimize energy intake + + + align:start position:0% +animal should optimize energy intake +Minus cost and that leads to these kinds + + align:start position:0% +Minus cost and that leads to these kinds + + + align:start position:0% +Minus cost and that leads to these kinds +of questions why should a feeding animal + + align:start position:0% +of questions why should a feeding animal + + + align:start position:0% +of questions why should a feeding animal +move to another patch of fluid if he's + + align:start position:0% +move to another patch of fluid if he's + + + align:start position:0% +move to another patch of fluid if he's +at a rich patch yet we often observe + + align:start position:0% +at a rich patch yet we often observe + + + align:start position:0% +at a rich patch yet we often observe +they move to other patches too why do + + align:start position:0% +they move to other patches too why do + + + align:start position:0% +they move to other patches too why do +they do that how long should a dive last + + align:start position:0% +they do that how long should a dive last + + + align:start position:0% +they do that how long should a dive last +if he's a diving animal or a diving bird + + align:start position:0% +if he's a diving animal or a diving bird + + + align:start position:0% +if he's a diving animal or a diving bird +or a or a seaman what determines that + + align:start position:0% +or a or a seaman what determines that + + + align:start position:0% +or a or a seaman what determines that +why do they evolve the kind of behavior + + align:start position:0% +why do they evolve the kind of behavior + + + align:start position:0% +why do they evolve the kind of behavior +they've + + align:start position:0% +they've + + + align:start position:0% +they've +evolved I picked these examples from the + + align:start position:0% +evolved I picked these examples from the + + + align:start position:0% +evolved I picked these examples from the +book uh to discuss a little bit the + + align:start position:0% +book uh to discuss a little bit the + + + align:start position:0% +book uh to discuss a little bit the +first question is crabs why do crabs + + align:start position:0% +first question is crabs why do crabs + + + align:start position:0% +first question is crabs why do crabs +choose to feed on intermediate Siz + + align:start position:0% +choose to feed on intermediate Siz + + + align:start position:0% +choose to feed on intermediate Siz +muscles instead of the bigger more meaty + + align:start position:0% +muscles instead of the bigger more meaty + + + align:start position:0% +muscles instead of the bigger more meaty +larger + + align:start position:0% + + + + align:start position:0% + +muscles they generally ignore the + + align:start position:0% +muscles they generally ignore the + + + align:start position:0% +muscles they generally ignore the +smallest ones but they also will ignore + + align:start position:0% +smallest ones but they also will ignore + + + align:start position:0% +smallest ones but they also will ignore +the largest ones and pick the + + align:start position:0% +the largest ones and pick the + + + align:start position:0% +the largest ones and pick the +intermediate sized ones and if they + + align:start position:0% +intermediate sized ones and if they + + + align:start position:0% +intermediate sized ones and if they +deplete those then they'll feed on the + + align:start position:0% +deplete those then they'll feed on the + + + align:start position:0% +deplete those then they'll feed on the +smaller ones why don't they feed on + + align:start position:0% +smaller ones why don't they feed on + + + align:start position:0% +smaller ones why don't they feed on +those big meaty ones because they're so + + align:start position:0% +those big meaty ones because they're so + + + align:start position:0% +those big meaty ones because they're so +hard to open it takes so much energy + + align:start position:0% +hard to open it takes so much energy + + + align:start position:0% +hard to open it takes so much energy +okay so it's a very simple matter of + + align:start position:0% +okay so it's a very simple matter of + + + align:start position:0% +okay so it's a very simple matter of +remember energy intake minus costs so + + align:start position:0% +remember energy intake minus costs so + + + align:start position:0% +remember energy intake minus costs so +you have to take the costs into account + + align:start position:0% +you have to take the costs into account + + + align:start position:0% +you have to take the costs into account +if you're going to explain the foraging + + align:start position:0% +if you're going to explain the foraging + + + align:start position:0% +if you're going to explain the foraging +of that of these uh + + align:start position:0% +of that of these uh + + + align:start position:0% +of that of these uh +animals here we're talking about + + align:start position:0% +animals here we're talking about + + + align:start position:0% +animals here we're talking about +crabs if we deal with marine + + align:start position:0% +crabs if we deal with marine + + + align:start position:0% +crabs if we deal with marine +iguana uh we note that the large ones + + align:start position:0% +iguana uh we note that the large ones + + + align:start position:0% +iguana uh we note that the large ones +feed like this one they feed sub tially + + align:start position:0% +feed like this one they feed sub tially + + + align:start position:0% +feed like this one they feed sub tially +that is at high tide they will be out in + + align:start position:0% +that is at high tide they will be out in + + + align:start position:0% +that is at high tide they will be out in +the deeper water uh catching + + align:start position:0% +the deeper water uh catching + + + align:start position:0% +the deeper water uh catching +food here's a whole group of them now + + align:start position:0% +food here's a whole group of them now + + + align:start position:0% +food here's a whole group of them now +the smaller ones in fact generally don't + + align:start position:0% +the smaller ones in fact generally don't + + + align:start position:0% +the smaller ones in fact generally don't +do that in in fact you can if you keep + + align:start position:0% +do that in in fact you can if you keep + + + align:start position:0% +do that in in fact you can if you keep +track of their size you can put them in + + align:start position:0% +track of their size you can put them in + + + align:start position:0% +track of their size you can put them in +three groups you know the big ones like + + align:start position:0% +three groups you know the big ones like + + + align:start position:0% +three groups you know the big ones like +this you know the intermediate ones and + + align:start position:0% +this you know the intermediate ones and + + + align:start position:0% +this you know the intermediate ones and +the small ones the small ones all feed + + align:start position:0% +the small ones the small ones all feed + + + align:start position:0% +the small ones the small ones all feed +at low tide in the shallow water none of + + align:start position:0% +at low tide in the shallow water none of + + + align:start position:0% +at low tide in the shallow water none of +them feed + + align:start position:0% +them feed + + + align:start position:0% +them feed +subtit in the intermediate only in the + + align:start position:0% +subtit in the intermediate only in the + + + align:start position:0% +subtit in the intermediate only in the +intermediate size you will see some of + + align:start position:0% +intermediate size you will see some of + + + align:start position:0% +intermediate size you will see some of +them feeding in both + + align:start position:0% + + + + align:start position:0% + +situations so what is the reason very + + align:start position:0% +situations so what is the reason very + + + align:start position:0% +situations so what is the reason very +simple the they lose body heat remember + + align:start position:0% +simple the they lose body heat remember + + + align:start position:0% +simple the they lose body heat remember +these are reptiles and they lose body + + align:start position:0% +these are reptiles and they lose body + + + align:start position:0% +these are reptiles and they lose body +heat when and it's colder there in the + + align:start position:0% +heat when and it's colder there in the + + + align:start position:0% +heat when and it's colder there in the +deeper water at high tide so uh that is + + align:start position:0% +deeper water at high tide so uh that is + + + align:start position:0% +deeper water at high tide so uh that is +a cost because they have to make up for + + align:start position:0% +a cost because they have to make up for + + + align:start position:0% +a cost because they have to make up for +it they have to eat rapidly enough that + + align:start position:0% +it they have to eat rapidly enough that + + + align:start position:0% +it they have to eat rapidly enough that +they can by afternoon when the sun is + + align:start position:0% +they can by afternoon when the sun is + + + align:start position:0% +they can by afternoon when the sun is +out and they can sit on the rocks and + + align:start position:0% +out and they can sit on the rocks and + + + align:start position:0% +out and they can sit on the rocks and +Heat their bodies up + + align:start position:0% +Heat their bodies up + + + align:start position:0% +Heat their bodies up +again and if they have they're smaller + + align:start position:0% +again and if they have they're smaller + + + align:start position:0% +again and if they have they're smaller +they have to and they're not catching + + align:start position:0% +they have to and they're not catching + + + align:start position:0% +they have to and they're not catching +the food as well especially because + + align:start position:0% +the food as well especially because + + + align:start position:0% +the food as well especially because +they're slowed down because they're + + align:start position:0% +they're slowed down because they're + + + align:start position:0% +they're slowed down because they're +getting cold you know they might not + + align:start position:0% +getting cold you know they might not + + + align:start position:0% +getting cold you know they might not +warm up in time so it's much more + + align:start position:0% +warm up in time so it's much more + + + align:start position:0% +warm up in time so it's much more +efficient for them to feed in the less + + align:start position:0% +efficient for them to feed in the less + + + align:start position:0% +efficient for them to feed in the less +productive shallow water + + align:start position:0% + + + + align:start position:0% + +okay let's talk about now the foraging + + align:start position:0% +okay let's talk about now the foraging + + + align:start position:0% +okay let's talk about now the foraging +Birds again for in this case dealing + + align:start position:0% +Birds again for in this case dealing + + + align:start position:0% +Birds again for in this case dealing +with the red Shank + + align:start position:0% +with the red Shank + + + align:start position:0% +with the red Shank +um I'm asking here why they why do they + + align:start position:0% +um I'm asking here why they why do they + + + align:start position:0% +um I'm asking here why they why do they +visit less productive patches in + + align:start position:0% +visit less productive patches in + + + align:start position:0% +visit less productive patches in +addition to their focus on the most + + align:start position:0% +addition to their focus on the most + + + align:start position:0% +addition to their focus on the most +productive areas for finding the large + + align:start position:0% +productive areas for finding the large + + + align:start position:0% +productive areas for finding the large +worms that they feed on in the ocean + + align:start position:0% +worms that they feed on in the ocean + + + align:start position:0% +worms that they feed on in the ocean +bottom and the reason they do it + + align:start position:0% +bottom and the reason they do it + + + align:start position:0% +bottom and the reason they do it +apparently is to get information about + + align:start position:0% +apparently is to get information about + + + align:start position:0% +apparently is to get information about +food availability they they seem to be + + align:start position:0% +food availability they they seem to be + + + align:start position:0% +food availability they they seem to be +they find a need to know what's the + + align:start position:0% +they find a need to know what's the + + + align:start position:0% +they find a need to know what's the +relative density of food in all the + + align:start position:0% +relative density of food in all the + + + align:start position:0% +relative density of food in all the +nearby feeding areas + + align:start position:0% + + + + align:start position:0% + +and also they need to know how many + + align:start position:0% +and also they need to know how many + + + align:start position:0% +and also they need to know how many +birds are there at each one because no + + align:start position:0% +birds are there at each one because no + + + align:start position:0% +birds are there at each one because no +matter how rich it is if there's already + + align:start position:0% +matter how rich it is if there's already + + + align:start position:0% +matter how rich it is if there's already +a huge number of birds there you know + + align:start position:0% +a huge number of birds there you know + + + align:start position:0% +a huge number of birds there you know +the amount one animal is going to get is + + align:start position:0% +the amount one animal is going to get is + + + align:start position:0% +the amount one animal is going to get is +going to be + + align:start position:0% + + + + align:start position:0% + +reduced okay these are red Shanks + + align:start position:0% +reduced okay these are red Shanks + + + align:start position:0% +reduced okay these are red Shanks +there's + + align:start position:0% +there's + + + align:start position:0% +there's +one showing him by himself you see the + + align:start position:0% +one showing him by himself you see the + + + align:start position:0% +one showing him by himself you see the +kind of shallow water that they look for + + align:start position:0% +kind of shallow water that they look for + + + align:start position:0% +kind of shallow water that they look for +those worms in U here he's poking below + + align:start position:0% +those worms in U here he's poking below + + + align:start position:0% +those worms in U here he's poking below +the the water to pull out a worm here's + + align:start position:0% +the the water to pull out a worm here's + + + align:start position:0% +the the water to pull out a worm here's +a group of them and they normally forage + + align:start position:0% +a group of them and they normally forage + + + align:start position:0% +a group of them and they normally forage +in groups like + + align:start position:0% +in groups like + + + align:start position:0% +in groups like +this so we talk about the ideal free + + align:start position:0% +this so we talk about the ideal free + + + align:start position:0% +this so we talk about the ideal free +distribution in a in a description of + + align:start position:0% +distribution in a in a description of + + + align:start position:0% +distribution in a in a description of +foraging by groups of animals so what do + + align:start position:0% +foraging by groups of animals so what do + + + align:start position:0% +foraging by groups of animals so what do +we mean by + + align:start position:0% +we mean by + + + align:start position:0% +we mean by +that an animal will tend to go to a less + + align:start position:0% +that an animal will tend to go to a less + + + align:start position:0% +that an animal will tend to go to a less +Rich Food Patch if joining a group of + + align:start position:0% +Rich Food Patch if joining a group of + + + align:start position:0% +Rich Food Patch if joining a group of +animals at a richer patch would reduce + + align:start position:0% +animals at a richer patch would reduce + + + align:start position:0% +animals at a richer patch would reduce +the amount of food per animal there to a + + align:start position:0% +the amount of food per animal there to a + + + align:start position:0% +the amount of food per animal there to a +point below it it could get at the less + + align:start position:0% +point below it it could get at the less + + + align:start position:0% +point below it it could get at the less +Rich PA you say well how could he + + align:start position:0% +Rich PA you say well how could he + + + align:start position:0% +Rich PA you say well how could he +possibly know that they do and they do + + align:start position:0% +possibly know that they do and they do + + + align:start position:0% +possibly know that they do and they do +it by this sampling method that I'm + + align:start position:0% +it by this sampling method that I'm + + + align:start position:0% +it by this sampling method that I'm +talking about they're collecting + + align:start position:0% +talking about they're collecting + + + align:start position:0% +talking about they're collecting +information all all of them none of them + + align:start position:0% +information all all of them none of them + + + align:start position:0% +information all all of them none of them +will stay at that rich patch all the + + align:start position:0% +will stay at that rich patch all the + + + align:start position:0% +will stay at that rich patch all the +time they're always flying away a + + align:start position:0% +time they're always flying away a + + + align:start position:0% +time they're always flying away a +certain percentage of their time + + align:start position:0% +certain percentage of their time + + + align:start position:0% +certain percentage of their time +sampling the other areas so they know + + align:start position:0% +sampling the other areas so they know + + + align:start position:0% +sampling the other areas so they know +what the average is for that + + align:start position:0% +what the average is for that + + + align:start position:0% +what the average is for that +area so they've evolved so they + + align:start position:0% +area so they've evolved so they + + + align:start position:0% +area so they've evolved so they +distribute themselves in an optim + + align:start position:0% +distribute themselves in an optim + + + align:start position:0% +distribute themselves in an optim +optimal way to avoid excessive + + align:start position:0% +optimal way to avoid excessive + + + align:start position:0% +optimal way to avoid excessive +competition and this guy chof developed + + align:start position:0% +competition and this guy chof developed + + + align:start position:0% +competition and this guy chof developed +the ideal way they could do it if they + + align:start position:0% +the ideal way they could do it if they + + + align:start position:0% +the ideal way they could do it if they +had all the information then to make it + + align:start position:0% +had all the information then to make it + + + align:start position:0% +had all the information then to make it +more practical uh he modified it uh so + + align:start position:0% +more practical uh he modified it uh so + + + align:start position:0% +more practical uh he modified it uh so +they know now that an animal seems to + + align:start position:0% +they know now that an animal seems to + + + align:start position:0% +they know now that an animal seems to +sample food sources in a region enough + + align:start position:0% +sample food sources in a region enough + + + align:start position:0% +sample food sources in a region enough +to know the average density of the + + align:start position:0% +to know the average density of the + + + align:start position:0% +to know the average density of the +available food + + align:start position:0% +available food + + + align:start position:0% +available food +items and it changes its foraging + + align:start position:0% +items and it changes its foraging + + + align:start position:0% +items and it changes its foraging +location when food density drops + + align:start position:0% +location when food density drops + + + align:start position:0% +location when food density drops +down to or below the average density of + + align:start position:0% +down to or below the average density of + + + align:start position:0% +down to or below the average density of +the + + align:start position:0% +the + + + align:start position:0% +the +area but there is an additional factor + + align:start position:0% +area but there is an additional factor + + + align:start position:0% +area but there is an additional factor +that I needs to be brought up and that + + align:start position:0% +that I needs to be brought up and that + + + align:start position:0% +that I needs to be brought up and that +is the dominant animals often will + + align:start position:0% +is the dominant animals often will + + + align:start position:0% +is the dominant animals often will +exclude the subordinates in the rich + + align:start position:0% +exclude the subordinates in the rich + + + align:start position:0% +exclude the subordinates in the rich +patches so the animals that that are + + align:start position:0% +patches so the animals that that are + + + align:start position:0% +patches so the animals that that are +more likely to be at a less Rich patch + + align:start position:0% +more likely to be at a less Rich patch + + + align:start position:0% +more likely to be at a less Rich patch +of food early on even though there's + + align:start position:0% +of food early on even though there's + + + align:start position:0% +of food early on even though there's +still a lot of worms left at the rich + + align:start position:0% +still a lot of worms left at the rich + + + align:start position:0% +still a lot of worms left at the rich +patch are the less dominant + + align:start position:0% +patch are the less dominant + + + align:start position:0% +patch are the less dominant +animals just the they're each each + + align:start position:0% +animals just the they're each each + + + align:start position:0% +animals just the they're each each +optimizing their feeding success because + + align:start position:0% +optimizing their feeding success because + + + align:start position:0% +optimizing their feeding success because +they have to take into account how much + + align:start position:0% +they have to take into account how much + + + align:start position:0% +they have to take into account how much +time they're going to be allowed to + + align:start position:0% +time they're going to be allowed to + + + align:start position:0% +time they're going to be allowed to +forage by those dominant animals okay + + align:start position:0% +forage by those dominant animals okay + + + align:start position:0% +forage by those dominant animals okay +and this is from Scott a figure Scott uh + + align:start position:0% +and this is from Scott a figure Scott uh + + + align:start position:0% +and this is from Scott a figure Scott uh +publishes where there's two patches of + + align:start position:0% +publishes where there's two patches of + + + align:start position:0% +publishes where there's two patches of +food uh the profitability is on the + + align:start position:0% +food uh the profitability is on the + + + align:start position:0% +food uh the profitability is on the +ordinate so you see one patch is a lot + + align:start position:0% +ordinate so you see one patch is a lot + + + align:start position:0% +ordinate so you see one patch is a lot +more profitable than others + + align:start position:0% +more profitable than others + + + align:start position:0% +more profitable than others +but how profitable it is depends on the + + align:start position:0% +but how profitable it is depends on the + + + align:start position:0% +but how profitable it is depends on the +numbers you can see if there's between + + align:start position:0% +numbers you can see if there's between + + + align:start position:0% +numbers you can see if there's between +one and five animals you can see if + + align:start position:0% +one and five animals you can see if + + + align:start position:0% +one and five animals you can see if +there's five it's it's becoming less + + align:start position:0% +there's five it's it's becoming less + + + align:start position:0% +there's five it's it's becoming less +profitable you it drops down to the + + align:start position:0% +profitable you it drops down to the + + + align:start position:0% +profitable you it drops down to the +point that is labeled X there then it's + + align:start position:0% +point that is labeled X there then it's + + + align:start position:0% +point that is labeled X there then it's +just as profitable for him to be in the + + align:start position:0% +just as profitable for him to be in the + + + align:start position:0% +just as profitable for him to be in the +other less Rich path at the point + + align:start position:0% +other less Rich path at the point + + + align:start position:0% +other less Rich path at the point +labeled why there okay and that of + + align:start position:0% +labeled why there okay and that of + + + align:start position:0% +labeled why there okay and that of +course depends on numbers of animals + + align:start position:0% +course depends on numbers of animals + + + align:start position:0% +course depends on numbers of animals +there too um + + align:start position:0% +there too um + + + align:start position:0% +there too um +and that would affect the shape of these + + align:start position:0% +and that would affect the shape of these + + + align:start position:0% +and that would affect the shape of these +curves but that basically is why animals + + align:start position:0% +curves but that basically is why animals + + + align:start position:0% +curves but that basically is why animals +will move they collect enough + + align:start position:0% +will move they collect enough + + + align:start position:0% +will move they collect enough +information to be able to judge + + align:start position:0% +information to be able to judge + + + align:start position:0% +information to be able to judge +profitability of each of those areas and + + align:start position:0% +profitability of each of those areas and + + + align:start position:0% +profitability of each of those areas and +they also seem quite aware of the number + + align:start position:0% +they also seem quite aware of the number + + + align:start position:0% +they also seem quite aware of the number +of + + align:start position:0% +of + + + align:start position:0% +of +animals at each place that feeding they + + align:start position:0% +animals at each place that feeding they + + + align:start position:0% +animals at each place that feeding they +know the rate that the food is being + + align:start position:0% + + + + align:start position:0% + +depleted so what do they do if there's a + + align:start position:0% +depleted so what do they do if there's a + + + align:start position:0% +depleted so what do they do if there's a +predator near you can't just because + + align:start position:0% +predator near you can't just because + + + align:start position:0% +predator near you can't just because +there Predators around there's often + + align:start position:0% +there Predators around there's often + + + align:start position:0% +there Predators around there's often +Predators around you can't stop + + align:start position:0% +Predators around you can't stop + + + align:start position:0% +Predators around you can't stop +eating so when you study that and study + + align:start position:0% +eating so when you study that and study + + + align:start position:0% +eating so when you study that and study +the conflict they have uh it's been + + align:start position:0% +the conflict they have uh it's been + + + align:start position:0% +the conflict they have uh it's been +studied quantitatively in these two + + align:start position:0% +studied quantitatively in these two + + + align:start position:0% +studied quantitatively in these two +types of goes the sand goes and black + + align:start position:0% +types of goes the sand goes and black + + + align:start position:0% +types of goes the sand goes and black +goes uh it's observed that feeding + + align:start position:0% +goes uh it's observed that feeding + + + align:start position:0% +goes uh it's observed that feeding +decreases as you would expect if a + + align:start position:0% +decreases as you would expect if a + + + align:start position:0% +decreases as you would expect if a +predator is detected nearby because they + + align:start position:0% +predator is detected nearby because they + + + align:start position:0% +predator is detected nearby because they +have to spend more of their time + + align:start position:0% +have to spend more of their time + + + align:start position:0% +have to spend more of their time +avoiding that predator or hiding from + + align:start position:0% +avoiding that predator or hiding from + + + align:start position:0% +avoiding that predator or hiding from +him uh but that effect is less if the + + align:start position:0% +him uh but that effect is less if the + + + align:start position:0% +him uh but that effect is less if the +animals are hungrier in other words they + + align:start position:0% +animals are hungrier in other words they + + + align:start position:0% +animals are hungrier in other words they +will be more risky in their behavior if + + align:start position:0% +will be more risky in their behavior if + + + align:start position:0% +will be more risky in their behavior if +they're very + + align:start position:0% +they're very + + + align:start position:0% +they're very +hungry but it's also less if they're + + align:start position:0% +hungry but it's also less if they're + + + align:start position:0% +hungry but it's also less if they're +better camouflage and the sand goes are + + align:start position:0% +better camouflage and the sand goes are + + + align:start position:0% +better camouflage and the sand goes are +better camouflag than the black goes so + + align:start position:0% +better camouflag than the black goes so + + + align:start position:0% +better camouflag than the black goes so +they were less affected by the presence + + align:start position:0% +they were less affected by the presence + + + align:start position:0% +they were less affected by the presence +of a + + align:start position:0% +of a + + + align:start position:0% +of a +predator they have in inate difference + + align:start position:0% +predator they have in inate difference + + + align:start position:0% +predator they have in inate difference +you know it's like it's as if they knew + + align:start position:0% +you know it's like it's as if they knew + + + align:start position:0% +you know it's like it's as if they knew +that they're camouflage and they're + + align:start position:0% +that they're camouflage and they're + + + align:start position:0% +that they're camouflage and they're +going to be harder for the the Predator + + align:start position:0% +going to be harder for the the Predator + + + align:start position:0% +going to be harder for the the Predator +to see + + align:start position:0% + + + + align:start position:0% + +so I wondered I'm asking the question + + align:start position:0% +so I wondered I'm asking the question + + + align:start position:0% +so I wondered I'm asking the question +here is is this ideal free distribution + + align:start position:0% +here is is this ideal free distribution + + + align:start position:0% +here is is this ideal free distribution +relevant to population control at all + + align:start position:0% +relevant to population control at all + + + align:start position:0% +relevant to population control at all +the answer appears to be no because the + + align:start position:0% +the answer appears to be no because the + + + align:start position:0% +the answer appears to be no because the +models anyway of it don't attempt to + + align:start position:0% +models anyway of it don't attempt to + + + align:start position:0% +models anyway of it don't attempt to +extend overall population control but + + align:start position:0% +extend overall population control but + + + align:start position:0% +extend overall population control but +only to small foraging groups it would + + align:start position:0% +only to small foraging groups it would + + + align:start position:0% +only to small foraging groups it would +be too much of an extrapolation to + + align:start position:0% +be too much of an extrapolation to + + + align:start position:0% +be too much of an extrapolation to +extend it to an entire + + align:start position:0% +extend it to an entire + + + align:start position:0% +extend it to an entire +population uh that has been been studied + + align:start position:0% +population uh that has been been studied + + + align:start position:0% +population uh that has been been studied +scientifically and we know that + + align:start position:0% +scientifically and we know that + + + align:start position:0% +scientifically and we know that +overcrowding has been studied + + align:start position:0% +overcrowding has been studied + + + align:start position:0% +overcrowding has been studied +extensively in rats but there are some + + align:start position:0% +extensively in rats but there are some + + + align:start position:0% +extensively in rats but there are some +studies in other species as well we know + + align:start position:0% +studies in other species as well we know + + + align:start position:0% +studies in other species as well we know +that fertility goes + + align:start position:0% +that fertility goes + + + align:start position:0% +that fertility goes +down uh they end up with impaired immune + + align:start position:0% +down uh they end up with impaired immune + + + align:start position:0% +down uh they end up with impaired immune +system so you get more illness more + + align:start position:0% +system so you get more illness more + + + align:start position:0% +system so you get more illness more +infections they became more they become + + align:start position:0% +infections they became more they become + + + align:start position:0% +infections they became more they become +more irritable they fight + + align:start position:0% +more irritable they fight + + + align:start position:0% +more irritable they fight +more uh if you look at their adrenal + + align:start position:0% +more uh if you look at their adrenal + + + align:start position:0% +more uh if you look at their adrenal +glands you see that they're secreting a + + align:start position:0% +glands you see that they're secreting a + + + align:start position:0% +glands you see that they're secreting a +lot more adrenaline they have larger + + align:start position:0% +lot more adrenaline they have larger + + + align:start position:0% +lot more adrenaline they have larger +adrenals + + align:start position:0% + + + + align:start position:0% + +and you also see in these groups really + + align:start position:0% +and you also see in these groups really + + + align:start position:0% +and you also see in these groups really +sudden population declines not just + + align:start position:0% +sudden population declines not just + + + align:start position:0% +sudden population declines not just +because they're being caught by + + align:start position:0% +because they're being caught by + + + align:start position:0% +because they're being caught by +Predators but because of these other + + align:start position:0% +Predators but because of these other + + + align:start position:0% +Predators but because of these other +factors + + align:start position:0% +factors + + + align:start position:0% +factors +and this has been observed for many + + align:start position:0% +and this has been observed for many + + + align:start position:0% +and this has been observed for many +small mammals that tend to be to + + align:start position:0% +small mammals that tend to be to + + + align:start position:0% +small mammals that tend to be to +reproduce very very rapidly and they + + align:start position:0% +reproduce very very rapidly and they + + + align:start position:0% +reproduce very very rapidly and they +reach + + align:start position:0% + + + + align:start position:0% + +uh they tend to move towards an area + + align:start position:0% +uh they tend to move towards an area + + + align:start position:0% +uh they tend to move towards an area +that's maximal for what what the + + align:start position:0% +that's maximal for what what the + + + align:start position:0% +that's maximal for what what the +environment at that time can + + align:start position:0% +environment at that time can + + + align:start position:0% +environment at that time can +support + + align:start position:0% +support + + + align:start position:0% +support +um but if they become overpopulated you + + align:start position:0% +um but if they become overpopulated you + + + align:start position:0% +um but if they become overpopulated you +get population crashes it's very well + + align:start position:0% +get population crashes it's very well + + + align:start position:0% +get population crashes it's very well +known for some small mammals you + + align:start position:0% +known for some small mammals you + + + align:start position:0% +known for some small mammals you +probably know about the lemings that + + align:start position:0% +probably know about the lemings that + + + align:start position:0% +probably know about the lemings that +when they become overcrowded in + + align:start position:0% +when they become overcrowded in + + + align:start position:0% +when they become overcrowded in +Scandinavia they you end up with they + + align:start position:0% +Scandinavia they you end up with they + + + align:start position:0% +Scandinavia they you end up with they +migrate in large numbers and sometimes + + align:start position:0% +migrate in large numbers and sometimes + + + align:start position:0% +migrate in large numbers and sometimes +they seem to get confused in their + + align:start position:0% +they seem to get confused in their + + + align:start position:0% +they seem to get confused in their +navigation and they they will swim out + + align:start position:0% +navigation and they they will swim out + + + align:start position:0% +navigation and they they will swim out +to sea when they normally they're just + + align:start position:0% +to sea when they normally they're just + + + align:start position:0% +to sea when they normally they're just +swimming across the fs to get to another + + align:start position:0% +swimming across the fs to get to another + + + align:start position:0% +swimming across the fs to get to another +area where there might be fewer Lemmings + + align:start position:0% +area where there might be fewer Lemmings + + + align:start position:0% +area where there might be fewer Lemmings +but sometimes they just swim out to to + + align:start position:0% +but sometimes they just swim out to to + + + align:start position:0% +but sometimes they just swim out to to +seea as if they're committing suicide + + align:start position:0% +seea as if they're committing suicide + + + align:start position:0% +seea as if they're committing suicide +but it appears to be a navigational + + align:start position:0% +but it appears to be a navigational + + + align:start position:0% +but it appears to be a navigational +problem and it could be because of + + align:start position:0% +problem and it could be because of + + + align:start position:0% +problem and it could be because of +malfunctioning nervous + + align:start position:0% +malfunctioning nervous + + + align:start position:0% +malfunctioning nervous +systems okay I don't want to discuss M + + align:start position:0% +systems okay I don't want to discuss M + + + align:start position:0% +systems okay I don't want to discuss M +murder right now we can do that later we + + align:start position:0% +murder right now we can do that later we + + + align:start position:0% +murder right now we can do that later we +talk about + + align:start position:0% +talk about + + + align:start position:0% +talk about +sociobiology uh but what we'll do is I + + align:start position:0% +sociobiology uh but what we'll do is I + + + align:start position:0% +sociobiology uh but what we'll do is I +want to get started talking a little bit + + align:start position:0% +want to get started talking a little bit + + + align:start position:0% +want to get started talking a little bit +about Andy Predator Behavior which is + + align:start position:0% +about Andy Predator Behavior which is + + + align:start position:0% +about Andy Predator Behavior which is +the next topic because I have there's a + + align:start position:0% +the next topic because I have there's a + + + align:start position:0% +the next topic because I have there's a +couple of nice videos I want to + + align:start position:0% +couple of nice videos I want to + + + align:start position:0% +couple of nice videos I want to +show + + align:start position:0% + + + + align:start position:0% + +uh uh especially + + align:start position:0% +uh uh especially + + + align:start position:0% +uh uh especially +one about animals escaping from + + align:start position:0% +one about animals escaping from + + + align:start position:0% +one about animals escaping from +predators so you can see that for a + + align:start position:0% +predators so you can see that for a + + + align:start position:0% +predators so you can see that for a +number of Predator prey + + align:start position:0% +number of Predator prey + + + align:start position:0% +number of Predator prey +relationships + + align:start position:0% +relationships + + + align:start position:0% +relationships +uh Scott starts out talking about + + align:start position:0% +uh Scott starts out talking about + + + align:start position:0% +uh Scott starts out talking about +anti-predator behavior in his chapter 7 + + align:start position:0% +anti-predator behavior in his chapter 7 + + + align:start position:0% +anti-predator behavior in his chapter 7 +by distinguishing between primary and + + align:start position:0% +by distinguishing between primary and + + + align:start position:0% +by distinguishing between primary and +secondary defense strategies of prey + + align:start position:0% +secondary defense strategies of prey + + + align:start position:0% +secondary defense strategies of prey +animals and these are defined like this + + align:start position:0% +animals and these are defined like this + + + align:start position:0% +animals and these are defined like this +primary strategy simply decreases the + + align:start position:0% +primary strategy simply decreases the + + + align:start position:0% +primary strategy simply decreases the +probability of being attacked so if he's + + align:start position:0% +probability of being attacked so if he's + + + align:start position:0% +probability of being attacked so if he's +camouflaged or if he has good hiding + + align:start position:0% +camouflaged or if he has good hiding + + + align:start position:0% +camouflaged or if he has good hiding +strategies then the probability he'll be + + align:start position:0% +strategies then the probability he'll be + + + align:start position:0% +strategies then the probability he'll be +attacked is reduced he times his + + align:start position:0% +attacked is reduced he times his + + + align:start position:0% +attacked is reduced he times his +foraging i h hamster comes out only when + + align:start position:0% +foraging i h hamster comes out only when + + + align:start position:0% +foraging i h hamster comes out only when +the Shadows are long in the Twilight + + align:start position:0% +the Shadows are long in the Twilight + + + align:start position:0% +the Shadows are long in the Twilight +period so he doesn't come out when he's + + align:start position:0% +period so he doesn't come out when he's + + + align:start position:0% +period so he doesn't come out when he's +easier to + + align:start position:0% +easier to + + + align:start position:0% +easier to +see and he comes out when there's still + + align:start position:0% +see and he comes out when there's still + + + align:start position:0% +see and he comes out when there's still +some light but the Shadows are long it's + + align:start position:0% +some light but the Shadows are long it's + + + align:start position:0% +some light but the Shadows are long it's +easier for him to + + align:start position:0% +easier for him to + + + align:start position:0% +easier for him to +hide animals are active at night or day + + align:start position:0% +hide animals are active at night or day + + + align:start position:0% +hide animals are active at night or day +for similar reasons then you have group + + align:start position:0% +for similar reasons then you have group + + + align:start position:0% +for similar reasons then you have group +foraging again that decreases the + + align:start position:0% +foraging again that decreases the + + + align:start position:0% +foraging again that decreases the +probability that any one animal will be + + align:start position:0% +probability that any one animal will be + + + align:start position:0% +probability that any one animal will be +attacked and then of course you have + + align:start position:0% +attacked and then of course you have + + + align:start position:0% +attacked and then of course you have +warning + + align:start position:0% +warning + + + align:start position:0% +warning +calls sometimes they're responding to + + align:start position:0% +calls sometimes they're responding to + + + align:start position:0% +calls sometimes they're responding to +warning calls of another + + align:start position:0% +warning calls of another + + + align:start position:0% +warning calls of another +species secondary strategies are when an + + align:start position:0% +species secondary strategies are when an + + + align:start position:0% +species secondary strategies are when an +attack does occur they need ways to get + + align:start position:0% +attack does occur they need ways to get + + + align:start position:0% +attack does occur they need ways to get +away from it + + align:start position:0% +away from it + + + align:start position:0% +away from it +and + + align:start position:0% +and + + + align:start position:0% +and +fleeing as rapidly as + + align:start position:0% +fleeing as rapidly as + + + align:start position:0% +fleeing as rapidly as +possible and dodging the Predator + + align:start position:0% +possible and dodging the Predator + + + align:start position:0% +possible and dodging the Predator +chasing them is extremely important and + + align:start position:0% +chasing them is extremely important and + + + align:start position:0% +chasing them is extremely important and +you will see in the video I'll show uh + + align:start position:0% +you will see in the video I'll show uh + + + align:start position:0% +you will see in the video I'll show uh +next time how successful that can be it + + align:start position:0% +next time how successful that can be it + + + align:start position:0% +next time how successful that can be it +tires out the + + align:start position:0% +tires out the + + + align:start position:0% +tires out the +Predator uh greatly increases the chance + + align:start position:0% +Predator uh greatly increases the chance + + + align:start position:0% +Predator uh greatly increases the chance +of getting + + align:start position:0% +of getting + + + align:start position:0% +of getting +away + + align:start position:0% +away + + + align:start position:0% +away +uh having very high endurance is + + align:start position:0% +uh having very high endurance is + + + align:start position:0% +uh having very high endurance is +important if they can they have to be + + align:start position:0% +important if they can they have to be + + + align:start position:0% +important if they can they have to be +able to outrun a predator and keep + + align:start position:0% +able to outrun a predator and keep + + + align:start position:0% +able to outrun a predator and keep +running without tiring so the more + + align:start position:0% +running without tiring so the more + + + align:start position:0% +running without tiring so the more +endurance they have the better some of + + align:start position:0% +endurance they have the better some of + + + align:start position:0% +endurance they have the better some of +them will just have the a play dead + + align:start position:0% +them will just have the a play dead + + + align:start position:0% +them will just have the a play dead +strategy the aosom is well known for + + align:start position:0% +strategy the aosom is well known for + + + align:start position:0% +strategy the aosom is well known for +that but there are other animals that do + + align:start position:0% +that but there are other animals that do + + + align:start position:0% +that but there are other animals that do +that also you know why would they do + + align:start position:0% +that also you know why would they do + + + align:start position:0% +that also you know why would they do +that well because if they act like + + align:start position:0% +that well because if they act like + + + align:start position:0% +that well because if they act like +they're dead and they're totally + + align:start position:0% +they're dead and they're totally + + + align:start position:0% +they're dead and they're totally +still it's doesn't + + align:start position:0% +still it's doesn't + + + align:start position:0% +still it's doesn't +evoke predation Behavior as much the + + align:start position:0% +evoke predation Behavior as much the + + + align:start position:0% +evoke predation Behavior as much the +Predator is likely to lose + + align:start position:0% +Predator is likely to lose + + + align:start position:0% +Predator is likely to lose +interest or he might just say well I can + + align:start position:0% +interest or he might just say well I can + + + align:start position:0% +interest or he might just say well I can +come back to this one it's dead + + align:start position:0% +come back to this one it's dead + + + align:start position:0% +come back to this one it's dead +anyway you + + align:start position:0% +anyway you + + + align:start position:0% +anyway you +know so we will see some of that + + align:start position:0% + + + + align:start position:0% + +okay what is + + align:start position:0% + + + + align:start position:0% + +countershading and I'm asking another + + align:start position:0% +countershading and I'm asking another + + + align:start position:0% +countershading and I'm asking another +question there besides what it is why + + align:start position:0% +question there besides what it is why + + + align:start position:0% +question there besides what it is why +would seapods need a countershading + + align:start position:0% +would seapods need a countershading + + + align:start position:0% +would seapods need a countershading +reflex okay well here's an example of + + align:start position:0% +reflex okay well here's an example of + + + align:start position:0% +reflex okay well here's an example of +cter shading there's actually two birds + + align:start position:0% +cter shading there's actually two birds + + + align:start position:0% +cter shading there's actually two birds +here how many do you + + align:start position:0% + + + + align:start position:0% + +see you see this + + align:start position:0% +see you see this + + + align:start position:0% +see you see this +one because he's got countershading + + align:start position:0% +one because he's got countershading + + + align:start position:0% +one because he's got countershading +that's opposite to what it would be + + align:start position:0% +that's opposite to what it would be + + + align:start position:0% +that's opposite to what it would be +normally it's a model normally birds are + + align:start position:0% +normally it's a model normally birds are + + + align:start position:0% +normally it's a model normally birds are +lighter on the underside + + align:start position:0% +lighter on the underside + + + align:start position:0% +lighter on the underside +darker on the upper side because when + + align:start position:0% +darker on the upper side because when + + + align:start position:0% +darker on the upper side because when +you're above a bird and you're let's say + + align:start position:0% +you're above a bird and you're let's say + + + align:start position:0% +you're above a bird and you're let's say +you're an eagle you're hunting for small + + align:start position:0% +you're an eagle you're hunting for small + + + align:start position:0% +you're an eagle you're hunting for small +birds flying down + + align:start position:0% +birds flying down + + + align:start position:0% +birds flying down +below if those birds are dark on top + + align:start position:0% +below if those birds are dark on top + + + align:start position:0% +below if those birds are dark on top +you're less likely to see them because + + align:start position:0% +you're less likely to see them because + + + align:start position:0% +you're less likely to see them because +the ground is generally a lot darker + + align:start position:0% +the ground is generally a lot darker + + + align:start position:0% +the ground is generally a lot darker +than the sky above so they tend to be + + align:start position:0% +than the sky above so they tend to be + + + align:start position:0% +than the sky above so they tend to be +but if the prey if the bird of prey is + + align:start position:0% +but if the prey if the bird of prey is + + + align:start position:0% +but if the prey if the bird of prey is +below and he looks up he's less likely + + align:start position:0% +below and he looks up he's less likely + + + align:start position:0% +below and he looks up he's less likely +to notice Birds if they're light on the + + align:start position:0% +to notice Birds if they're light on the + + + align:start position:0% +to notice Birds if they're light on the +underside so with reverse counter + + align:start position:0% +underside so with reverse counter + + + align:start position:0% +underside so with reverse counter +shading it makes this bird stand out but + + align:start position:0% +shading it makes this bird stand out but + + + align:start position:0% +shading it makes this bird stand out but +the other one that's in there is + + align:start position:0% +the other one that's in there is + + + align:start position:0% +the other one that's in there is +camouflaged uh and so it's very hard to + + align:start position:0% +camouflaged uh and so it's very hard to + + + align:start position:0% +camouflaged uh and so it's very hard to +make out exactly where it is at least in + + align:start position:0% +make out exactly where it is at least in + + + align:start position:0% +make out exactly where it is at least in +the black white photo so the these are + + align:start position:0% +the black white photo so the these are + + + align:start position:0% +the black white photo so the these are +um a year or two ago Jenny woo was in + + align:start position:0% +um a year or two ago Jenny woo was in + + + align:start position:0% +um a year or two ago Jenny woo was in +the class and she pulled these off the + + align:start position:0% +the class and she pulled these off the + + + align:start position:0% +the class and she pulled these off the +web by the time I got to the topic is + + align:start position:0% +web by the time I got to the topic is + + + align:start position:0% +web by the time I got to the topic is +she was already doing the reading and + + align:start position:0% +she was already doing the reading and + + + align:start position:0% +she was already doing the reading and +she found these very nice + + align:start position:0% +she found these very nice + + + align:start position:0% +she found these very nice +illustrations + + align:start position:0% + + + + align:start position:0% + +uh if the the animals in these pictures + + align:start position:0% +uh if the the animals in these pictures + + + align:start position:0% +uh if the the animals in these pictures +don't move they're very hard to see and + + align:start position:0% +don't move they're very hard to see and + + + align:start position:0% +don't move they're very hard to see and +I point out what's there you know it's + + align:start position:0% +I point out what's there you know it's + + + align:start position:0% +I point out what's there you know it's +not that easy to tell that that's the + + align:start position:0% +not that easy to tell that that's the + + + align:start position:0% +not that easy to tell that that's the +body of a spider right + + align:start position:0% +body of a spider right + + + align:start position:0% +body of a spider right +there here the crab is sort of easy to + + align:start position:0% +there here the crab is sort of easy to + + + align:start position:0% +there here the crab is sort of easy to +see but if you're just glancing around + + align:start position:0% +see but if you're just glancing around + + + align:start position:0% +see but if you're just glancing around +and the there's a lot of unevenness in + + align:start position:0% +and the there's a lot of unevenness in + + + align:start position:0% +and the there's a lot of unevenness in +the gravel bottom of the water it's very + + align:start position:0% +the gravel bottom of the water it's very + + + align:start position:0% +the gravel bottom of the water it's very +hard to to see that crab and here again + + align:start position:0% +hard to to see that crab and here again + + + align:start position:0% +hard to to see that crab and here again +if you're glancing around you don't + + align:start position:0% +if you're glancing around you don't + + + align:start position:0% +if you're glancing around you don't +notice that frog there that + + align:start position:0% +notice that frog there that + + + align:start position:0% +notice that frog there that +easily and here the + + align:start position:0% + + + + align:start position:0% + +dragonfly + + align:start position:0% +dragonfly + + + align:start position:0% +dragonfly +only if I it's only because I tell you + + align:start position:0% +only if I it's only because I tell you + + + align:start position:0% +only if I it's only because I tell you +there's a dragonfly there that you will + + align:start position:0% +there's a dragonfly there that you will + + + align:start position:0% +there's a dragonfly there that you will +probably make out oh yeah there's some + + align:start position:0% +probably make out oh yeah there's some + + + align:start position:0% +probably make out oh yeah there's some +legs there and there's a head there and + + align:start position:0% +legs there and there's a head there and + + + align:start position:0% +legs there and there's a head there and +uh here's some other examples there's a + + align:start position:0% +uh here's some other examples there's a + + + align:start position:0% +uh here's some other examples there's a +bird in this picture a leaf + + align:start position:0% +bird in this picture a leaf + + + align:start position:0% +bird in this picture a leaf +warbler well camouflaged he looks just + + align:start position:0% +warbler well camouflaged he looks just + + + align:start position:0% +warbler well camouflaged he looks just +like the leaves um here the Jaguar a + + align:start position:0% +like the leaves um here the Jaguar a + + + align:start position:0% +like the leaves um here the Jaguar a +predator is pretty well camouflaged hard + + align:start position:0% +predator is pretty well camouflaged hard + + + align:start position:0% +predator is pretty well camouflaged hard +for prey animals to see him when he's + + align:start position:0% +for prey animals to see him when he's + + + align:start position:0% +for prey animals to see him when he's +still that's why a a predator will spend + + align:start position:0% +still that's why a a predator will spend + + + align:start position:0% +still that's why a a predator will spend +quite a bit of time you know + + align:start position:0% +quite a bit of time you know + + + align:start position:0% +quite a bit of time you know +still and when he does move he moves + + align:start position:0% +still and when he does move he moves + + + align:start position:0% +still and when he does move he moves +rapidly to a new place Waits + + align:start position:0% +rapidly to a new place Waits + + + align:start position:0% +rapidly to a new place Waits +again and here there's the caterpillar + + align:start position:0% +again and here there's the caterpillar + + + align:start position:0% +again and here there's the caterpillar +on that + + align:start position:0% +on that + + + align:start position:0% +on that +leaf almost impossible to see but that's + + align:start position:0% +leaf almost impossible to see but that's + + + align:start position:0% +leaf almost impossible to see but that's +the outline of the caterpillar + + align:start position:0% +the outline of the caterpillar + + + align:start position:0% +the outline of the caterpillar +there um if you don't know he's there I + + align:start position:0% +there um if you don't know he's there I + + + align:start position:0% +there um if you don't know he's there I +don't think you'd notice it at all in + + align:start position:0% +don't think you'd notice it at all in + + + align:start position:0% +don't think you'd notice it at all in +the picture just like here the + + align:start position:0% +the picture just like here the + + + align:start position:0% +the picture just like here the +grasshopper taken in Colorado uh + + align:start position:0% +grasshopper taken in Colorado uh + + + align:start position:0% +grasshopper taken in Colorado uh +very hard to see if you look very + + align:start position:0% +very hard to see if you look very + + + align:start position:0% +very hard to see if you look very +carefully you'll see that there's an eye + + align:start position:0% +carefully you'll see that there's an eye + + + align:start position:0% +carefully you'll see that there's an eye +right there I think + + align:start position:0% +right there I think + + + align:start position:0% +right there I think +okay that's + + align:start position:0% + + + + align:start position:0% + +camouflage so we'll start the class next + + align:start position:0% +camouflage so we'll start the class next + + + align:start position:0% +camouflage so we'll start the class next +time about Predators who because + + align:start position:0% +time about Predators who because + + + align:start position:0% +time about Predators who because +Predators develop search images they + + align:start position:0% +Predators develop search images they + + + align:start position:0% +Predators develop search images they +have an image of the prey they're + + align:start position:0% +have an image of the prey they're + + + align:start position:0% +have an image of the prey they're +looking for and octopus and squid have + + align:start position:0% +looking for and octopus and squid have + + + align:start position:0% +looking for and octopus and squid have +developed an incredible ability + + align:start position:0% +developed an incredible ability + + + align:start position:0% +developed an incredible ability +to counter that ability by changing + + align:start position:0% +to counter that ability by changing + + + align:start position:0% +to counter that ability by changing +their appearance and so we'll + + align:start position:0% +their appearance and so we'll + + + align:start position:0% +their appearance and so we'll +start with this next + + align:start position:0% + + + + align:start position:0% + +time \ No newline at end of file diff --git a/umt6BB1nJ4w.txt b/umt6BB1nJ4w.txt new file mode 100644 index 0000000000000000000000000000000000000000..6498e926af634713222cf3b631e0cc6e54844e5e --- /dev/null +++ b/umt6BB1nJ4w.txt @@ -0,0 +1,6651 @@ +align:start position:0% + +one and + + align:start position:0% +one and + + + align:start position:0% +one and +the lecture on symmetric matrices. + + align:start position:0% +the lecture on symmetric matrices. + + + align:start position:0% +the lecture on symmetric matrices. +So that's the most important class of + + align:start position:0% +So that's the most important class of + + + align:start position:0% +So that's the most important class of +matrices symmetric matrices A equals A + + align:start position:0% +matrices symmetric matrices A equals A + + + align:start position:0% +matrices symmetric matrices A equals A +transpose. So the first points, the main + + align:start position:0% +transpose. So the first points, the main + + + align:start position:0% +transpose. So the first points, the main +points of the lecture, I'll tell you + + align:start position:0% +points of the lecture, I'll tell you + + + align:start position:0% +points of the lecture, I'll tell you +right away + + align:start position:0% +right away + + + align:start position:0% +right away +what's special about the igen values. + + align:start position:0% +what's special about the igen values. + + + align:start position:0% +what's special about the igen values. +What's special about the igen vectors? + + align:start position:0% +What's special about the igen vectors? + + + align:start position:0% +What's special about the igen vectors? +This is now + + align:start position:0% +This is now + + + align:start position:0% +This is now +this is the way we now look at a matrix. + + align:start position:0% +this is the way we now look at a matrix. + + + align:start position:0% +this is the way we now look at a matrix. +We want to know about its igen values + + align:start position:0% +We want to know about its igen values + + + align:start position:0% +We want to know about its igen values +and igen vectors. And if we have a + + align:start position:0% +and igen vectors. And if we have a + + + align:start position:0% +and igen vectors. And if we have a +special type of matrix that should tell + + align:start position:0% +special type of matrix that should tell + + + align:start position:0% +special type of matrix that should tell +us something about igen values and igen + + align:start position:0% +us something about igen values and igen + + + align:start position:0% +us something about igen values and igen +vectors like markoff matrices they had + + align:start position:0% +vectors like markoff matrices they had + + + align:start position:0% +vectors like markoff matrices they had +an igen value equal one. Now, symmetric + + align:start position:0% +an igen value equal one. Now, symmetric + + + align:start position:0% +an igen value equal one. Now, symmetric +matrices, can I just tell you right off + + align:start position:0% +matrices, can I just tell you right off + + + align:start position:0% +matrices, can I just tell you right off +what the main facts, the two main facts + + align:start position:0% +what the main facts, the two main facts + + + align:start position:0% +what the main facts, the two main facts +are? The igen values of a symmetric + + align:start position:0% +are? The igen values of a symmetric + + + align:start position:0% +are? The igen values of a symmetric +matrix real. This is a real symmetric + + align:start position:0% +matrix real. This is a real symmetric + + + align:start position:0% +matrix real. This is a real symmetric +matrix. We talking mostly about real + + align:start position:0% +matrix. We talking mostly about real + + + align:start position:0% +matrix. We talking mostly about real +matrices. The igen values are also real. + + align:start position:0% + + + + align:start position:0% + +So our examples of rotation matrices + + align:start position:0% +So our examples of rotation matrices + + + align:start position:0% +So our examples of rotation matrices +where where we got igen values that were + + align:start position:0% +where where we got igen values that were + + + align:start position:0% +where where we got igen values that were +complex + + align:start position:0% +complex + + + align:start position:0% +complex +that won't happen now for symmetric + + align:start position:0% +that won't happen now for symmetric + + + align:start position:0% +that won't happen now for symmetric +matrices the Igen values are real and + + align:start position:0% +matrices the Igen values are real and + + + align:start position:0% +matrices the Igen values are real and +the igen vectors are also very special + + align:start position:0% +the igen vectors are also very special + + + align:start position:0% +the igen vectors are also very special +the igen vectors are perpendicular + + align:start position:0% +the igen vectors are perpendicular + + + align:start position:0% +the igen vectors are perpendicular +orthogonal which do you prefer I'll say + + align:start position:0% +orthogonal which do you prefer I'll say + + + align:start position:0% +orthogonal which do you prefer I'll say +perpendicular per well they're both long + + align:start position:0% +perpendicular per well they're both long + + + align:start position:0% +perpendicular per well they're both long +words perpendic pick. + + align:start position:0% + + + + align:start position:0% + +Okay. Right. So, uh + + align:start position:0% +Okay. Right. So, uh + + + align:start position:0% +Okay. Right. So, uh +I have uh you should say why and I'll at + + align:start position:0% +I have uh you should say why and I'll at + + + align:start position:0% +I have uh you should say why and I'll at +least answer why for case one. Maybe + + align:start position:0% +least answer why for case one. Maybe + + + align:start position:0% +least answer why for case one. Maybe +case two the checking the igen that the + + align:start position:0% +case two the checking the igen that the + + + align:start position:0% +case two the checking the igen that the +igen vectors are perpendicular I'll + + align:start position:0% +igen vectors are perpendicular I'll + + + align:start position:0% +igen vectors are perpendicular I'll +leave to um uh the the book. + + align:start position:0% +leave to um uh the the book. + + + align:start position:0% +leave to um uh the the book. +But let's just realize what well first I + + align:start position:0% +But let's just realize what well first I + + + align:start position:0% +But let's just realize what well first I +have to say + + align:start position:0% +have to say + + + align:start position:0% +have to say +it it could happen like for the identity + + align:start position:0% +it it could happen like for the identity + + + align:start position:0% +it it could happen like for the identity +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +there's a symmetric matrix its igen + + align:start position:0% +there's a symmetric matrix its igen + + + align:start position:0% +there's a symmetric matrix its igen +values are certainly all real they're + + align:start position:0% +values are certainly all real they're + + + align:start position:0% +values are certainly all real they're +all one for the identity matrix what + + align:start position:0% +all one for the identity matrix what + + + align:start position:0% +all one for the identity matrix what +about the igen vectors well for the + + align:start position:0% +about the igen vectors well for the + + + align:start position:0% +about the igen vectors well for the +identity every vector is an igen vector + + align:start position:0% +identity every vector is an igen vector + + + align:start position:0% +identity every vector is an igen vector +so how can I say they're perpendicular + + align:start position:0% +so how can I say they're perpendicular + + + align:start position:0% +so how can I say they're perpendicular +What I really mean is the they this word + + align:start position:0% +What I really mean is the they this word + + + align:start position:0% +What I really mean is the they this word +r should really be written can be chosen + + align:start position:0% + + + + align:start position:0% + +perpendicular + + align:start position:0% +perpendicular + + + align:start position:0% +perpendicular +that is I if we have it's the usual case + + align:start position:0% +that is I if we have it's the usual case + + + align:start position:0% +that is I if we have it's the usual case +if the igen values are all different + + align:start position:0% +if the igen values are all different + + + align:start position:0% +if the igen values are all different +then each igen value has one line of + + align:start position:0% +then each igen value has one line of + + + align:start position:0% +then each igen value has one line of +igen vectors and those lines are + + align:start position:0% +igen vectors and those lines are + + + align:start position:0% +igen vectors and those lines are +perpendicular here + + align:start position:0% +perpendicular here + + + align:start position:0% +perpendicular here +but if an igen value is repeated + + align:start position:0% +but if an igen value is repeated + + + align:start position:0% +but if an igen value is repeated +then there's a whole plane of igen + + align:start position:0% +then there's a whole plane of igen + + + align:start position:0% +then there's a whole plane of igen +vectors and all I'm saying is that in + + align:start position:0% +vectors and all I'm saying is that in + + + align:start position:0% +vectors and all I'm saying is that in +that plane we can choose perpendicular + + align:start position:0% +that plane we can choose perpendicular + + + align:start position:0% +that plane we can choose perpendicular +ones. So that's why it's a can be chosen + + align:start position:0% +ones. So that's why it's a can be chosen + + + align:start position:0% +ones. So that's why it's a can be chosen +part is this is in the case of a + + align:start position:0% +part is this is in the case of a + + + align:start position:0% +part is this is in the case of a +repeated igen value where there's some + + align:start position:0% +repeated igen value where there's some + + + align:start position:0% +repeated igen value where there's some +real substantial freedom. But the + + align:start position:0% +real substantial freedom. But the + + + align:start position:0% +real substantial freedom. But the +typical case is different values all + + align:start position:0% +typical case is different values all + + + align:start position:0% +typical case is different values all +realed + + align:start position:0% +realed + + + align:start position:0% +realed +one-dimensional + + align:start position:0% +one-dimensional + + + align:start position:0% +one-dimensional +vector spaces spaces and all + + align:start position:0% +vector spaces spaces and all + + + align:start position:0% +vector spaces spaces and all +perpendicular. So just let's just see + + align:start position:0% +perpendicular. So just let's just see + + + align:start position:0% +perpendicular. So just let's just see +the conclusion if if we accept those as + + align:start position:0% +the conclusion if if we accept those as + + + align:start position:0% +the conclusion if if we accept those as +correct what happens and I also mean + + align:start position:0% +correct what happens and I also mean + + + align:start position:0% +correct what happens and I also mean +that + + align:start position:0% +that + + + align:start position:0% +that +there's a full set of them I I + + align:start position:0% +there's a full set of them I I + + + align:start position:0% +there's a full set of them I I +so that's part of this picture here that + + align:start position:0% +so that's part of this picture here that + + + align:start position:0% +so that's part of this picture here that +there there's a complete set of igen + + align:start position:0% +there there's a complete set of igen + + + align:start position:0% +there there's a complete set of igen +vectors perpendicular ones so having a + + align:start position:0% +vectors perpendicular ones so having a + + + align:start position:0% +vectors perpendicular ones so having a +complete set of igen vectors means so + + align:start position:0% +complete set of igen vectors means so + + + align:start position:0% +complete set of igen vectors means so +normal + + align:start position:0% +normal + + + align:start position:0% +normal +Uh so the usual maybe I put the usually + + align:start position:0% +Uh so the usual maybe I put the usually + + + align:start position:0% +Uh so the usual maybe I put the usually +usual usual case is that the matrix A we + + align:start position:0% +usual usual case is that the matrix A we + + + align:start position:0% +usual usual case is that the matrix A we +can write in terms of its igen val + + align:start position:0% +can write in terms of its igen val + + + align:start position:0% +can write in terms of its igen val +matrix and its igen vector matrix this + + align:start position:0% +matrix and its igen vector matrix this + + + align:start position:0% +matrix and its igen vector matrix this +way right + + align:start position:0% +way right + + + align:start position:0% +way right +we can do that in the usual case but now + + align:start position:0% +we can do that in the usual case but now + + + align:start position:0% +we can do that in the usual case but now +what's special + + align:start position:0% +what's special + + + align:start position:0% +what's special +when the matrix is symmetric so this is + + align:start position:0% +when the matrix is symmetric so this is + + + align:start position:0% +when the matrix is symmetric so this is +the usual case and now let me go to the + + align:start position:0% +the usual case and now let me go to the + + + align:start position:0% +the usual case and now let me go to the +symmetric case. + + align:start position:0% + + + + align:start position:0% + +So in the symmetric case a this this + + align:start position:0% +So in the symmetric case a this this + + + align:start position:0% +So in the symmetric case a this this +should become somehow a little special. + + align:start position:0% +should become somehow a little special. + + + align:start position:0% +should become somehow a little special. +Well the lambdas + + align:start position:0% +Well the lambdas + + + align:start position:0% +Well the lambdas +on the diagonal are still on the + + align:start position:0% +on the diagonal are still on the + + + align:start position:0% +on the diagonal are still on the +diagonal. They're they're real but + + align:start position:0% +diagonal. They're they're real but + + + align:start position:0% +diagonal. They're they're real but +that's where they are. + + align:start position:0% +that's where they are. + + + align:start position:0% +that's where they are. +What about the igen vector matrix? + + align:start position:0% +What about the igen vector matrix? + + + align:start position:0% +What about the igen vector matrix? +So what can I do now special about the + + align:start position:0% +So what can I do now special about the + + + align:start position:0% +So what can I do now special about the +igen vector matrix when when the A + + align:start position:0% +igen vector matrix when when the A + + + align:start position:0% +igen vector matrix when when the A +itself is symmetric that says something + + align:start position:0% +itself is symmetric that says something + + + align:start position:0% +itself is symmetric that says something +good about the igen vector matrix. So + + align:start position:0% +good about the igen vector matrix. So + + + align:start position:0% +good about the igen vector matrix. So +what does this what does this lead to? + + align:start position:0% +what does this what does this lead to? + + + align:start position:0% +what does this what does this lead to? +This these perpendicular + + align:start position:0% +This these perpendicular + + + align:start position:0% +This these perpendicular +vectors. I can not only I I can not only + + align:start position:0% +vectors. I can not only I I can not only + + + align:start position:0% +vectors. I can not only I I can not only +guarantee they're perpendicular, I could + + align:start position:0% +guarantee they're perpendicular, I could + + + align:start position:0% +guarantee they're perpendicular, I could +also make them unit vectors. No problem. + + align:start position:0% +also make them unit vectors. No problem. + + + align:start position:0% +also make them unit vectors. No problem. +Just scale their length to one. So what + + align:start position:0% +Just scale their length to one. So what + + + align:start position:0% +Just scale their length to one. So what +do I have? I have orthonormal + + align:start position:0% + + + + align:start position:0% + +vectors. + + align:start position:0% + + + + align:start position:0% + +And what does that tell me about the + + align:start position:0% +And what does that tell me about the + + + align:start position:0% +And what does that tell me about the +igen vector matrix? What what letter + + align:start position:0% +igen vector matrix? What what letter + + + align:start position:0% +igen vector matrix? What what letter +should I now use + + align:start position:0% +should I now use + + + align:start position:0% +should I now use +in place of S? Remember S has the igen + + align:start position:0% +in place of S? Remember S has the igen + + + align:start position:0% +in place of S? Remember S has the igen +vectors in its columns. But now those + + align:start position:0% +vectors in its columns. But now those + + + align:start position:0% +vectors in its columns. But now those +columns are orthonormal. So the right + + align:start position:0% +columns are orthonormal. So the right + + + align:start position:0% +columns are orthonormal. So the right +letter to use is + + align:start position:0% +letter to use is + + + align:start position:0% +letter to use is +Q. So that's where so we've got the + + align:start position:0% +Q. So that's where so we've got the + + + align:start position:0% +Q. So that's where so we've got the +letter all set up. So this should be Q + + align:start position:0% +letter all set up. So this should be Q + + + align:start position:0% +letter all set up. So this should be Q +lambda Q inverse. + + align:start position:0% +lambda Q inverse. + + + align:start position:0% +lambda Q inverse. +Q standing in our minds always for this + + align:start position:0% +Q standing in our minds always for this + + + align:start position:0% +Q standing in our minds always for this +matrix. In this case it's square. It's + + align:start position:0% +matrix. In this case it's square. It's + + + align:start position:0% +matrix. In this case it's square. It's +it's so these are the columns of Q of + + align:start position:0% +it's so these are the columns of Q of + + + align:start position:0% +it's so these are the columns of Q of +course. + + align:start position:0% + + + + align:start position:0% + +And one more thing, + + align:start position:0% +And one more thing, + + + align:start position:0% +And one more thing, +what's Q inverse + + align:start position:0% +what's Q inverse + + + align:start position:0% +what's Q inverse +for an orthonormal for a matrix that has + + align:start position:0% +for an orthonormal for a matrix that has + + + align:start position:0% +for an orthonormal for a matrix that has +these orthonormal columns? + + align:start position:0% +these orthonormal columns? + + + align:start position:0% +these orthonormal columns? +We know that the inverse is the same as + + align:start position:0% +We know that the inverse is the same as + + + align:start position:0% +We know that the inverse is the same as +the transpose. So here is the beautiful + + align:start position:0% +the transpose. So here is the beautiful + + + align:start position:0% +the transpose. So here is the beautiful +there's the the great uh description the + + align:start position:0% +there's the the great uh description the + + + align:start position:0% +there's the the great uh description the +factorization of a symmetric matrix. And + + align:start position:0% +factorization of a symmetric matrix. And + + + align:start position:0% +factorization of a symmetric matrix. And +this is like one of the famous theorems + + align:start position:0% +this is like one of the famous theorems + + + align:start position:0% +this is like one of the famous theorems +of linear algebra that if I have a + + align:start position:0% +of linear algebra that if I have a + + + align:start position:0% +of linear algebra that if I have a +symmetric matrix, it can be factored in + + align:start position:0% +symmetric matrix, it can be factored in + + + align:start position:0% +symmetric matrix, it can be factored in +this form and an orthogonal matrix times + + align:start position:0% +this form and an orthogonal matrix times + + + align:start position:0% +this form and an orthogonal matrix times +diagonal times the transpose of that + + align:start position:0% +diagonal times the transpose of that + + + align:start position:0% +diagonal times the transpose of that +orthogonal matrix. And of course + + align:start position:0% +orthogonal matrix. And of course + + + align:start position:0% +orthogonal matrix. And of course +everybody immediately says yes. And if + + align:start position:0% +everybody immediately says yes. And if + + + align:start position:0% +everybody immediately says yes. And if +this is possible then that's clearly + + align:start position:0% +this is possible then that's clearly + + + align:start position:0% +this is possible then that's clearly +symmetric, right? that take we've looked + + align:start position:0% +symmetric, right? that take we've looked + + + align:start position:0% +symmetric, right? that take we've looked +at products of three guys like that and + + align:start position:0% +at products of three guys like that and + + + align:start position:0% +at products of three guys like that and +taken their transpose and we got it back + + align:start position:0% +taken their transpose and we got it back + + + align:start position:0% +taken their transpose and we got it back +again. + + align:start position:0% +again. + + + align:start position:0% +again. +So do you see the beauty of this of this + + align:start position:0% +So do you see the beauty of this of this + + + align:start position:0% +So do you see the beauty of this of this +uh factorization? Then it it completely + + align:start position:0% +uh factorization? Then it it completely + + + align:start position:0% +uh factorization? Then it it completely +displays the igen values and igen + + align:start position:0% +displays the igen values and igen + + + align:start position:0% +displays the igen values and igen +vectors and the symmetry of the of the + + align:start position:0% +vectors and the symmetry of the of the + + + align:start position:0% +vectors and the symmetry of the of the +whole thing because that product Q * + + align:start position:0% +whole thing because that product Q * + + + align:start position:0% +whole thing because that product Q * +lambda* qranspose if I transpose it it + + align:start position:0% +lambda* qranspose if I transpose it it + + + align:start position:0% +lambda* qranspose if I transpose it it +just comes in this position and we get + + align:start position:0% +just comes in this position and we get + + + align:start position:0% +just comes in this position and we get +that matrix back again. So that's in + + align:start position:0% +that matrix back again. So that's in + + + align:start position:0% +that matrix back again. So that's in +mathematics that's called the spectral + + align:start position:0% +mathematics that's called the spectral + + + align:start position:0% +mathematics that's called the spectral +theorem. Spectrum is the set of igen + + align:start position:0% +theorem. Spectrum is the set of igen + + + align:start position:0% +theorem. Spectrum is the set of igen +values of a matrix. Spec it somehow + + align:start position:0% +values of a matrix. Spec it somehow + + + align:start position:0% +values of a matrix. Spec it somehow +comes from the idea of the spectrum of + + align:start position:0% +comes from the idea of the spectrum of + + + align:start position:0% +comes from the idea of the spectrum of +light as a combination of of uh pure + + align:start position:0% +light as a combination of of uh pure + + + align:start position:0% +light as a combination of of uh pure +things + + align:start position:0% +things + + + align:start position:0% +things +where our matrix is broken down into + + align:start position:0% +where our matrix is broken down into + + + align:start position:0% +where our matrix is broken down into +pure values and igen vectors. uh in + + align:start position:0% +pure values and igen vectors. uh in + + + align:start position:0% +pure values and igen vectors. uh in +mechanics it's often called the + + align:start position:0% +mechanics it's often called the + + + align:start position:0% +mechanics it's often called the +principal axis theorem. It's very + + align:start position:0% +principal axis theorem. It's very + + + align:start position:0% +principal axis theorem. It's very +useful. It means that if you have uh we + + align:start position:0% +useful. It means that if you have uh we + + + align:start position:0% +useful. It means that if you have uh we +we'll see it geometrically. It means + + align:start position:0% +we'll see it geometrically. It means + + + align:start position:0% +we'll see it geometrically. It means +that if I have some material if I look + + align:start position:0% +that if I have some material if I look + + + align:start position:0% +that if I have some material if I look +at the right axes uh it becomes + + align:start position:0% +at the right axes uh it becomes + + + align:start position:0% +at the right axes uh it becomes +diagonal. It becomes uh um the the + + align:start position:0% +diagonal. It becomes uh um the the + + + align:start position:0% +diagonal. It becomes uh um the the +directions don't couple together. Okay. + + align:start position:0% +directions don't couple together. Okay. + + + align:start position:0% +directions don't couple together. Okay. +So that's that's what to remember. from + + align:start position:0% +So that's that's what to remember. from + + + align:start position:0% +So that's that's what to remember. from +this lecture. Now I would like to say + + align:start position:0% +this lecture. Now I would like to say + + + align:start position:0% +this lecture. Now I would like to say +why are the igen values real? + + align:start position:0% +why are the igen values real? + + + align:start position:0% +why are the igen values real? +Can I do that? So so because something + + align:start position:0% +Can I do that? So so because something + + + align:start position:0% +Can I do that? So so because something +useful comes out. So I'll just come back + + align:start position:0% +useful comes out. So I'll just come back + + + align:start position:0% +useful comes out. So I'll just come back +come to that question. Why + + align:start position:0% +come to that question. Why + + + align:start position:0% +come to that question. Why +real + + align:start position:0% +real + + + align:start position:0% +real +values? + + align:start position:0% + + + + align:start position:0% + +Okay. So I have to start from the only + + align:start position:0% +Okay. So I have to start from the only + + + align:start position:0% +Okay. So I have to start from the only +thing we know ax= lambda x. + + align:start position:0% + + + + align:start position:0% + +Okay. But as far as I know at this + + align:start position:0% +Okay. But as far as I know at this + + + align:start position:0% +Okay. But as far as I know at this +moment, lambda could be complex. I'm + + align:start position:0% +moment, lambda could be complex. I'm + + + align:start position:0% +moment, lambda could be complex. I'm +going to prove it's not and x could be + + align:start position:0% +going to prove it's not and x could be + + + align:start position:0% +going to prove it's not and x could be +complex. + + align:start position:0% +complex. + + + align:start position:0% +complex. +In fact, for the moment, even a could be + + align:start position:0% +In fact, for the moment, even a could be + + + align:start position:0% +In fact, for the moment, even a could be +we could even think, well, what happens + + align:start position:0% +we could even think, well, what happens + + + align:start position:0% +we could even think, well, what happens +if a is complex? Well, one thing we can + + align:start position:0% +if a is complex? Well, one thing we can + + + align:start position:0% +if a is complex? Well, one thing we can +always do this is this is like always + + align:start position:0% +always do this is this is like always + + + align:start position:0% +always do this is this is like always +always okay. + + align:start position:0% +always okay. + + + align:start position:0% +always okay. +I can if I have an equation I can take + + align:start position:0% +I can if I have an equation I can take + + + align:start position:0% +I can if I have an equation I can take +the complex conjugate of everything + + align:start position:0% +the complex conjugate of everything + + + align:start position:0% +the complex conjugate of everything +that's no no so a conjugate x conjugate + + align:start position:0% +that's no no so a conjugate x conjugate + + + align:start position:0% +that's no no so a conjugate x conjugate +equal lambda conjugate x conjugate + + align:start position:0% +equal lambda conjugate x conjugate + + + align:start position:0% +equal lambda conjugate x conjugate +that just means that everywhere over + + align:start position:0% +that just means that everywhere over + + + align:start position:0% +that just means that everywhere over +here that there was a + + align:start position:0% +here that there was a + + + align:start position:0% +here that there was a +an i then here I changed it to a minus i + + align:start position:0% +an i then here I changed it to a minus i + + + align:start position:0% +an i then here I changed it to a minus i +that you you know that that step that + + align:start position:0% +that you you know that that step that + + + align:start position:0% +that you you know that that step that +conjugate business that a plus I if I + + align:start position:0% +conjugate business that a plus I if I + + + align:start position:0% +conjugate business that a plus I if I +conjugate it it's a minus I that's the + + align:start position:0% +conjugate it it's a minus I that's the + + + align:start position:0% +conjugate it it's a minus I that's the +meaning of conjugate and products behave + + align:start position:0% +meaning of conjugate and products behave + + + align:start position:0% +meaning of conjugate and products behave +right I can conjugate every factor so I + + align:start position:0% +right I can conjugate every factor so I + + + align:start position:0% +right I can conjugate every factor so I +haven't done anything yet except to say + + align:start position:0% +haven't done anything yet except to say + + + align:start position:0% +haven't done anything yet except to say +what would be true + + align:start position:0% +what would be true + + + align:start position:0% +what would be true +if + + align:start position:0% +if + + + align:start position:0% +if +um + + align:start position:0% +um + + + align:start position:0% +um +x in any case even if x and lambda were + + align:start position:0% +x in any case even if x and lambda were + + + align:start position:0% +x in any case even if x and lambda were +complex of course our we're speaking + + align:start position:0% +complex of course our we're speaking + + + align:start position:0% +complex of course our we're speaking +about real matrices a so I take that + + align:start position:0% +about real matrices a so I take that + + + align:start position:0% +about real matrices a so I take that +out. Actually, + + align:start position:0% +out. Actually, + + + align:start position:0% +out. Actually, +this already tells me something about + + align:start position:0% +this already tells me something about + + + align:start position:0% +this already tells me something about +real matrices. I I I haven't used any + + align:start position:0% +real matrices. I I I haven't used any + + + align:start position:0% +real matrices. I I I haven't used any +assumption of a equal arpose yet. + + align:start position:0% +assumption of a equal arpose yet. + + + align:start position:0% +assumption of a equal arpose yet. +Symmetry is waiting in the wings to be + + align:start position:0% +Symmetry is waiting in the wings to be + + + align:start position:0% +Symmetry is waiting in the wings to be +used. This tells me that if a real + + align:start position:0% +used. This tells me that if a real + + + align:start position:0% +used. This tells me that if a real +matrix has an igen value lambda and an + + align:start position:0% +matrix has an igen value lambda and an + + + align:start position:0% +matrix has an igen value lambda and an +igen vector x, it also has another of + + align:start position:0% +igen vector x, it also has another of + + + align:start position:0% +igen vector x, it also has another of +its igen values is lambda bar with igen + + align:start position:0% +its igen values is lambda bar with igen + + + align:start position:0% +its igen values is lambda bar with igen +vector xbar. + + align:start position:0% +vector xbar. + + + align:start position:0% +vector xbar. +Real matrices the igen values come in + + align:start position:0% +Real matrices the igen values come in + + + align:start position:0% +Real matrices the igen values come in +lambda lambda bar. The complex igen + + align:start position:0% +lambda lambda bar. The complex igen + + + align:start position:0% +lambda lambda bar. The complex igen +values come in lambda and lambda bar + + align:start position:0% +values come in lambda and lambda bar + + + align:start position:0% +values come in lambda and lambda bar +pairs. But of course, I'm aiming to show + + align:start position:0% +pairs. But of course, I'm aiming to show + + + align:start position:0% +pairs. But of course, I'm aiming to show +that they're not complex at all here by + + align:start position:0% +that they're not complex at all here by + + + align:start position:0% +that they're not complex at all here by +getting symmetry in. So, how am I going + + align:start position:0% +getting symmetry in. So, how am I going + + + align:start position:0% +getting symmetry in. So, how am I going +to use symmetry? I'm going to transpose + + align:start position:0% +to use symmetry? I'm going to transpose + + + align:start position:0% +to use symmetry? I'm going to transpose +this equation + + align:start position:0% +this equation + + + align:start position:0% +this equation +to xar transpose a transpose equals xar + + align:start position:0% +to xar transpose a transpose equals xar + + + align:start position:0% +to xar transpose a transpose equals xar +transpose lambda bar. That's just a + + align:start position:0% +transpose lambda bar. That's just a + + + align:start position:0% +transpose lambda bar. That's just a +number. So, I don't mind where I put + + align:start position:0% +number. So, I don't mind where I put + + + align:start position:0% +number. So, I don't mind where I put +that number. + + align:start position:0% +that number. + + + align:start position:0% +that number. +This is this is then again okay + + align:start position:0% +This is this is then again okay + + + align:start position:0% +This is this is then again okay +but now + + align:start position:0% +but now + + + align:start position:0% +but now +I'm ready to use symmetry I'm ready so + + align:start position:0% +I'm ready to use symmetry I'm ready so + + + align:start position:0% +I'm ready to use symmetry I'm ready so +this was all just mechanics now now + + align:start position:0% +this was all just mechanics now now + + + align:start position:0% +this was all just mechanics now now +comes the moment to say okay if the + + align:start position:0% +comes the moment to say okay if the + + + align:start position:0% +comes the moment to say okay if the +matrix is symmetric then this arpose is + + align:start position:0% +matrix is symmetric then this arpose is + + + align:start position:0% +matrix is symmetric then this arpose is +the same as a you see at that moment I + + align:start position:0% +the same as a you see at that moment I + + + align:start position:0% +the same as a you see at that moment I +use the assumption now let me finish the + + align:start position:0% +use the assumption now let me finish the + + + align:start position:0% +use the assumption now let me finish the +discussion + + align:start position:0% +discussion + + + align:start position:0% +discussion +here. Here's the way I finish. I look at + + align:start position:0% +here. Here's the way I finish. I look at + + + align:start position:0% +here. Here's the way I finish. I look at +this original equation and I take the + + align:start position:0% +this original equation and I take the + + + align:start position:0% +this original equation and I take the +inner product. I multiply both sides by + + align:start position:0% +inner product. I multiply both sides by + + + align:start position:0% +inner product. I multiply both sides by +Oh, maybe I'll do it with this one. + + align:start position:0% +Oh, maybe I'll do it with this one. + + + align:start position:0% +Oh, maybe I'll do it with this one. +I take I multiply both sides by Xbar + + align:start position:0% +I take I multiply both sides by Xbar + + + align:start position:0% +I take I multiply both sides by Xbar +transpose. Xar transpose A Xar equals + + align:start position:0% +transpose. Xar transpose A Xar equals + + + align:start position:0% +transpose. Xar transpose A Xar equals +lambda bar Xar transpose + + align:start position:0% +lambda bar Xar transpose + + + align:start position:0% +lambda bar Xar transpose +Xbar. + + align:start position:0% +Xbar. + + + align:start position:0% +Xbar. +Okay, fine. + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +Now, what's the other one? Oh, the other + + align:start position:0% +Now, what's the other one? Oh, the other + + + align:start position:0% +Now, what's the other one? Oh, the other +one I'll probably use this guy. + + align:start position:0% +one I'll probably use this guy. + + + align:start position:0% +one I'll probably use this guy. +Uh, am I happy about this? + + align:start position:0% +Uh, am I happy about this? + + + align:start position:0% +Uh, am I happy about this? +No. For some reason, I'm not. I'm I'm I + + align:start position:0% +No. For some reason, I'm not. I'm I'm I + + + align:start position:0% +No. For some reason, I'm not. I'm I'm I +want to + + align:start position:0% +want to + + + align:start position:0% +want to +Yeah. If I take the inner product of + + align:start position:0% +Yeah. If I take the inner product of + + + align:start position:0% +Yeah. If I take the inner product of +this from the right with Xbar, I get Xar + + align:start position:0% +this from the right with Xbar, I get Xar + + + align:start position:0% +this from the right with Xbar, I get Xar +transpose A Xar equals Xar transpose + + align:start position:0% +transpose A Xar equals Xar transpose + + + align:start position:0% +transpose A Xar equals Xar transpose +lambda Xar. + + align:start position:0% + + + + align:start position:0% + +Um I've done something dumb because I've + + align:start position:0% +Um I've done something dumb because I've + + + align:start position:0% +Um I've done something dumb because I've +got the + + align:start position:0% + + + + align:start position:0% + +I haven't learned anything. I've got + + align:start position:0% +I haven't learned anything. I've got + + + align:start position:0% +I haven't learned anything. I've got +those two equations are identical. So, + + align:start position:0% +those two equations are identical. So, + + + align:start position:0% +those two equations are identical. So, +forgive me for doing such a thing, but + + align:start position:0% +forgive me for doing such a thing, but + + + align:start position:0% +forgive me for doing such a thing, but +um I'll look at the book. Um + + align:start position:0% +um I'll look at the book. Um + + + align:start position:0% +um I'll look at the book. Um +okay, + + align:start position:0% +okay, + + + align:start position:0% +okay, +so I took the dotproduct. + + align:start position:0% +so I took the dotproduct. + + + align:start position:0% +so I took the dotproduct. +Yeah, somehow it didn't I should have + + align:start position:0% +Yeah, somehow it didn't I should have + + + align:start position:0% +Yeah, somehow it didn't I should have +taken the dotproduct of this guy here + + align:start position:0% +taken the dotproduct of this guy here + + + align:start position:0% +taken the dotproduct of this guy here +with that's what I was going to do. a x + + align:start position:0% +with that's what I was going to do. a x + + + align:start position:0% +with that's what I was going to do. a x +equ= lambda xar transpose x right okay + + align:start position:0% +equ= lambda xar transpose x right okay + + + align:start position:0% +equ= lambda xar transpose x right okay +so that that was that's fine that comes + + align:start position:0% +so that that was that's fine that comes + + + align:start position:0% +so that that was that's fine that comes +directly from that multiplying both + + align:start position:0% +directly from that multiplying both + + + align:start position:0% +directly from that multiplying both +sides by xar transpose but now I'd like + + align:start position:0% +sides by xar transpose but now I'd like + + + align:start position:0% +sides by xar transpose but now I'd like +to get why do I have x bars over there + + align:start position:0% +to get why do I have x bars over there + + + align:start position:0% +to get why do I have x bars over there +oh + + align:start position:0% +oh + + + align:start position:0% +oh +yes forget this + + align:start position:0% +yes forget this + + + align:start position:0% +yes forget this +okay on this one right on this one I + + align:start position:0% +okay on this one right on this one I + + + align:start position:0% +okay on this one right on this one I +took it like that I multiply on the + + align:start position:0% +took it like that I multiply on the + + + align:start position:0% +took it like that I multiply on the +right by x that's the idea + + align:start position:0% +right by x that's the idea + + + align:start position:0% +right by x that's the idea +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now why am I happier with this + + align:start position:0% +now why am I happier with this + + + align:start position:0% +now why am I happier with this +situation now a proof is coming here + + align:start position:0% +situation now a proof is coming here + + + align:start position:0% +situation now a proof is coming here +because I compare this guy + + align:start position:0% +because I compare this guy + + + align:start position:0% +because I compare this guy +with this one and they have the same + + align:start position:0% +with this one and they have the same + + + align:start position:0% +with this one and they have the same +left hand side so they have the same + + align:start position:0% +left hand side so they have the same + + + align:start position:0% +left hand side so they have the same +right hand side so comparing those two. + + align:start position:0% +right hand side so comparing those two. + + + align:start position:0% +right hand side so comparing those two. +Can I I'll raise the board to do this + + align:start position:0% +Can I I'll raise the board to do this + + + align:start position:0% +Can I I'll raise the board to do this +comparison. + + align:start position:0% +comparison. + + + align:start position:0% +comparison. +This thing lambda xbar transpose x is + + align:start position:0% +This thing lambda xbar transpose x is + + + align:start position:0% +This thing lambda xbar transpose x is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +lambda bar + + align:start position:0% +lambda bar + + + align:start position:0% +lambda bar +xar transpose x. Okay. + + align:start position:0% +xar transpose x. Okay. + + + align:start position:0% +xar transpose x. Okay. +And the conclusion I'm going to reach, + + align:start position:0% +And the conclusion I'm going to reach, + + + align:start position:0% +And the conclusion I'm going to reach, +am I am I on the right track here? + + align:start position:0% +am I am I on the right track here? + + + align:start position:0% +am I am I on the right track here? +The conclusion I'm going to reach is + + align:start position:0% +The conclusion I'm going to reach is + + + align:start position:0% +The conclusion I'm going to reach is +lambda equal lambda bar. + + align:start position:0% + + + + align:start position:0% + +I I would have to track down the other + + align:start position:0% +I I would have to track down the other + + + align:start position:0% +I I would have to track down the other +possibility that this this thing is + + align:start position:0% +possibility that this this thing is + + + align:start position:0% +possibility that this this thing is +zero. But let me uh oh + + align:start position:0% +zero. But let me uh oh + + + align:start position:0% +zero. But let me uh oh +oh oh oh oh oh oh oh oh oh oh oh oh oh + + align:start position:0% +oh oh oh oh oh oh oh oh oh oh oh oh oh + + + align:start position:0% +oh oh oh oh oh oh oh oh oh oh oh oh oh +oh oh oh oh oh oh oh oh yeah yeah that's + + align:start position:0% +oh oh oh oh oh oh oh oh yeah yeah that's + + + align:start position:0% +oh oh oh oh oh oh oh oh yeah yeah that's +important. It's not zero. + + align:start position:0% +important. It's not zero. + + + align:start position:0% +important. It's not zero. +So + + align:start position:0% +So + + + align:start position:0% +So +once I know that this isn't zero I just + + align:start position:0% +once I know that this isn't zero I just + + + align:start position:0% +once I know that this isn't zero I just +cancel it and I learn that lambda equals + + align:start position:0% +cancel it and I learn that lambda equals + + + align:start position:0% +cancel it and I learn that lambda equals +lambda bar. And so what can you do you + + align:start position:0% +lambda bar. And so what can you do you + + + align:start position:0% +lambda bar. And so what can you do you +have you got the + + align:start position:0% +have you got the + + + align:start position:0% +have you got the +reasoning al together? + + align:start position:0% +reasoning al together? + + + align:start position:0% +reasoning al together? +What does this tell us? + + align:start position:0% +What does this tell us? + + + align:start position:0% +What does this tell us? +Lambda is an igen value of this + + align:start position:0% +Lambda is an igen value of this + + + align:start position:0% +Lambda is an igen value of this +symmetric matrix. + + align:start position:0% +symmetric matrix. + + + align:start position:0% +symmetric matrix. +We've just proved that it equal lambda + + align:start position:0% +We've just proved that it equal lambda + + + align:start position:0% +We've just proved that it equal lambda +bar. So we have just proved that lambda + + align:start position:0% +bar. So we have just proved that lambda + + + align:start position:0% +bar. So we have just proved that lambda +is real. Right? + + align:start position:0% +is real. Right? + + + align:start position:0% +is real. Right? +If if a number is equal to its own + + align:start position:0% +If if a number is equal to its own + + + align:start position:0% +If if a number is equal to its own +complex conjugate, then there's no + + align:start position:0% +complex conjugate, then there's no + + + align:start position:0% +complex conjugate, then there's no +imaginary part at all. The number is + + align:start position:0% +imaginary part at all. The number is + + + align:start position:0% +imaginary part at all. The number is +real. So lambda is real. + + align:start position:0% + + + + align:start position:0% + +Good. Good. + + align:start position:0% +Good. Good. + + + align:start position:0% +Good. Good. +Now what? But it depended on this little + + align:start position:0% +Now what? But it depended on this little + + + align:start position:0% +Now what? But it depended on this little +expression + + align:start position:0% +expression + + + align:start position:0% +expression +on knowing that that wasn't zero so that + + align:start position:0% +on knowing that that wasn't zero so that + + + align:start position:0% +on knowing that that wasn't zero so that +I could cancel it out. So can we just + + align:start position:0% +I could cancel it out. So can we just + + + align:start position:0% +I could cancel it out. So can we just +take a second on that one because it's + + align:start position:0% +take a second on that one because it's + + + align:start position:0% +take a second on that one because it's +an important quantity. + + align:start position:0% +an important quantity. + + + align:start position:0% +an important quantity. +Xar transpose X. Okay. Now remember + + align:start position:0% +Xar transpose X. Okay. Now remember + + + align:start position:0% +Xar transpose X. Okay. Now remember +as far as we know X is complex. + + align:start position:0% +as far as we know X is complex. + + + align:start position:0% +as far as we know X is complex. +So this is + + align:start position:0% +So this is + + + align:start position:0% +So this is +here X is complex. X has these + + align:start position:0% +here X is complex. X has these + + + align:start position:0% +here X is complex. X has these +components X1 X2 down to XN + + align:start position:0% +components X1 X2 down to XN + + + align:start position:0% +components X1 X2 down to XN +and Xar transpose. Well, it's transposed + + align:start position:0% +and Xar transpose. Well, it's transposed + + + align:start position:0% +and Xar transpose. Well, it's transposed +and it's conjugated. So that's X1 + + align:start position:0% +and it's conjugated. So that's X1 + + + align:start position:0% +and it's conjugated. So that's X1 +conjugated, X2 conjugated up to XN + + align:start position:0% +conjugated, X2 conjugated up to XN + + + align:start position:0% +conjugated, X2 conjugated up to XN +conjugated. I'm I'm I'm really reminding + + align:start position:0% +conjugated. I'm I'm I'm really reminding + + + align:start position:0% +conjugated. I'm I'm I'm really reminding +you of crucial facts about complex + + align:start position:0% +you of crucial facts about complex + + + align:start position:0% +you of crucial facts about complex +numbers that are going to come into the + + align:start position:0% +numbers that are going to come into the + + + align:start position:0% +numbers that are going to come into the +next lecture as well as this one. So + + align:start position:0% +next lecture as well as this one. So + + + align:start position:0% +next lecture as well as this one. So +what can you tell me about that product? + + align:start position:0% +what can you tell me about that product? + + + align:start position:0% +what can you tell me about that product? +I I guess what I'm trying to say is if I + + align:start position:0% +I I guess what I'm trying to say is if I + + + align:start position:0% +I I guess what I'm trying to say is if I +had a complex vector, + + align:start position:0% +had a complex vector, + + + align:start position:0% +had a complex vector, +this would be the quantity I would I + + align:start position:0% +this would be the quantity I would I + + + align:start position:0% +this would be the quantity I would I +would like. This is the quantity I like. + + align:start position:0% +would like. This is the quantity I like. + + + align:start position:0% +would like. This is the quantity I like. +I would take the vector + + align:start position:0% +I would take the vector + + + align:start position:0% +I would take the vector +times its transpose. Now what what + + align:start position:0% +times its transpose. Now what what + + + align:start position:0% +times its transpose. Now what what +happens usually if I take a vector + + align:start position:0% +happens usually if I take a vector + + + align:start position:0% +happens usually if I take a vector +xrpose x I mean that's a quantity we see + + align:start position:0% +xrpose x I mean that's a quantity we see + + + align:start position:0% +xrpose x I mean that's a quantity we see +all the time xrpose x that's the length + + align:start position:0% +all the time xrpose x that's the length + + + align:start position:0% +all the time xrpose x that's the length +of x squ right that's this positive + + align:start position:0% +of x squ right that's this positive + + + align:start position:0% +of x squ right that's this positive +length squared. It's pythagoras. It's + + align:start position:0% +length squared. It's pythagoras. It's + + + align:start position:0% +length squared. It's pythagoras. It's +x1^2 plus x2^2 and so on. Now our vector + + align:start position:0% +x1^2 plus x2^2 and so on. Now our vector + + + align:start position:0% +x1^2 plus x2^2 and so on. Now our vector +is complex and you see the effect. I'm + + align:start position:0% +is complex and you see the effect. I'm + + + align:start position:0% +is complex and you see the effect. I'm +conjugating one of these guys. So now + + align:start position:0% +conjugating one of these guys. So now + + + align:start position:0% +conjugating one of these guys. So now +when I do this multiplication I have x1 + + align:start position:0% +when I do this multiplication I have x1 + + + align:start position:0% +when I do this multiplication I have x1 +bar * x1 + + align:start position:0% +bar * x1 + + + align:start position:0% +bar * x1 +and x2 bar * x2 and so on. So this is an + + align:start position:0% +and x2 bar * x2 and so on. So this is an + + + align:start position:0% +and x2 bar * x2 and so on. So this is an +this is some a plus i + + align:start position:0% +this is some a plus i + + + align:start position:0% +this is some a plus i +and this is some a minus i. + + align:start position:0% +and this is some a minus i. + + + align:start position:0% +and this is some a minus i. +I mean what's the point here? + + align:start position:0% +I mean what's the point here? + + + align:start position:0% +I mean what's the point here? +What's the point? When I multiply a + + align:start position:0% +What's the point? When I multiply a + + + align:start position:0% +What's the point? When I multiply a +number by its conjugate, a complex + + align:start position:0% +number by its conjugate, a complex + + + align:start position:0% +number by its conjugate, a complex +number by its conjugate, what do I get? + + align:start position:0% +number by its conjugate, what do I get? + + + align:start position:0% +number by its conjugate, what do I get? +I get a the the imaginary part is gone. + + align:start position:0% +I get a the the imaginary part is gone. + + + align:start position:0% +I get a the the imaginary part is gone. +When I multiply a plus i by its + + align:start position:0% +When I multiply a plus i by its + + + align:start position:0% +When I multiply a plus i by its +conjugate, + + align:start position:0% +conjugate, + + + align:start position:0% +conjugate, +what's what's the result of that of each + + align:start position:0% +what's what's the result of that of each + + + align:start position:0% +what's what's the result of that of each +of those separate little + + align:start position:0% +of those separate little + + + align:start position:0% +of those separate little +multiplications? + + align:start position:0% +multiplications? + + + align:start position:0% +multiplications? +There's an a squared + + align:start position:0% +There's an a squared + + + align:start position:0% +There's an a squared +and and what how many what's b ^2 comes + + align:start position:0% +and and what how many what's b ^2 comes + + + align:start position:0% +and and what how many what's b ^2 comes +in with a plus or a minus? A plus + + align:start position:0% +in with a plus or a minus? A plus + + + align:start position:0% +in with a plus or a minus? A plus +i * minus i is a plus b^2. And what + + align:start position:0% +i * minus i is a plus b^2. And what + + + align:start position:0% +i * minus i is a plus b^2. And what +about the imaginary part? + + align:start position:0% + + + + align:start position:0% + +Gone, right? + + align:start position:0% +Gone, right? + + + align:start position:0% +Gone, right? +an I AB and a minus I AB. So this this + + align:start position:0% +an I AB and a minus I AB. So this this + + + align:start position:0% +an I AB and a minus I AB. So this this +is the right thing to do. If you want a + + align:start position:0% +is the right thing to do. If you want a + + + align:start position:0% +is the right thing to do. If you want a +decent answer, + + align:start position:0% + + + + align:start position:0% + +then multiply numbers by their + + align:start position:0% +then multiply numbers by their + + + align:start position:0% +then multiply numbers by their +conjugates. + + align:start position:0% +conjugates. + + + align:start position:0% +conjugates. +Multiply vectors by the conjugates of + + align:start position:0% +Multiply vectors by the conjugates of + + + align:start position:0% +Multiply vectors by the conjugates of +XRPOSE. + + align:start position:0% +XRPOSE. + + + align:start position:0% +XRPOSE. +So + + align:start position:0% +So + + + align:start position:0% +So +this quantity is positive. This quantity + + align:start position:0% +this quantity is positive. This quantity + + + align:start position:0% +this quantity is positive. This quantity +is positive. the whole thing is positive + + align:start position:0% +is positive. the whole thing is positive + + + align:start position:0% +is positive. the whole thing is positive +except for the zero vector and that + + align:start position:0% +except for the zero vector and that + + + align:start position:0% +except for the zero vector and that +allows me to know that this is a + + align:start position:0% +allows me to know that this is a + + + align:start position:0% +allows me to know that this is a +positive number which I safely cancel + + align:start position:0% +positive number which I safely cancel + + + align:start position:0% +positive number which I safely cancel +out and I reach the conclusion. So + + align:start position:0% +out and I reach the conclusion. So + + + align:start position:0% +out and I reach the conclusion. So +actually in this + + align:start position:0% +actually in this + + + align:start position:0% +actually in this +discussion here I've done two things. I + + align:start position:0% +discussion here I've done two things. I + + + align:start position:0% +discussion here I've done two things. I +I've reached the conclusion that lambda + + align:start position:0% +I've reached the conclusion that lambda + + + align:start position:0% +I've reached the conclusion that lambda +is real which I wanted to do. But at the + + align:start position:0% +is real which I wanted to do. But at the + + + align:start position:0% +is real which I wanted to do. But at the +same time we sort of saw what to do if + + align:start position:0% +same time we sort of saw what to do if + + + align:start position:0% +same time we sort of saw what to do if +things were complex. If a vector is + + align:start position:0% +things were complex. If a vector is + + + align:start position:0% +things were complex. If a vector is +complex then it's xar transpose x. This + + align:start position:0% +complex then it's xar transpose x. This + + + align:start position:0% +complex then it's xar transpose x. This +is its length + + align:start position:0% + + + + align:start position:0% + +squared. + + align:start position:0% +squared. + + + align:start position:0% +squared. +And as I said the the next lecture + + align:start position:0% +And as I said the the next lecture + + + align:start position:0% +And as I said the the next lecture +Monday will will repeat that this is the + + align:start position:0% +Monday will will repeat that this is the + + + align:start position:0% +Monday will will repeat that this is the +right thing and then do the right thing + + align:start position:0% +right thing and then do the right thing + + + align:start position:0% +right thing and then do the right thing +for matrices and all other all other uh + + align:start position:0% +for matrices and all other all other uh + + + align:start position:0% +for matrices and all other all other uh +complex possibilities. + + align:start position:0% +complex possibilities. + + + align:start position:0% +complex possibilities. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +But the main point then is that the igen + + align:start position:0% +But the main point then is that the igen + + + align:start position:0% +But the main point then is that the igen +values of a symmetric matrix + + align:start position:0% +values of a symmetric matrix + + + align:start position:0% +values of a symmetric matrix +it just where did we use symmetry by the + + align:start position:0% +it just where did we use symmetry by the + + + align:start position:0% +it just where did we use symmetry by the +way? We used it here, right? + + align:start position:0% +way? We used it here, right? + + + align:start position:0% +way? We used it here, right? +Can I just + + align:start position:0% +Can I just + + + align:start position:0% +Can I just +suppose A was a complex suppose A had + + align:start position:0% +suppose A was a complex suppose A had + + + align:start position:0% +suppose A was a complex suppose A had +been a complex number. Could could I + + align:start position:0% +been a complex number. Could could I + + + align:start position:0% +been a complex number. Could could I +have made all this work? If A was a + + align:start position:0% +have made all this work? If A was a + + + align:start position:0% +have made all this work? If A was a +complex number, complex matrix, then + + align:start position:0% +complex number, complex matrix, then + + + align:start position:0% +complex number, complex matrix, then +here I should have written a bar. + + align:start position:0% +here I should have written a bar. + + + align:start position:0% +here I should have written a bar. +I erased the bar because I assumed A was + + align:start position:0% +I erased the bar because I assumed A was + + + align:start position:0% +I erased the bar because I assumed A was +real. But now let's suppose for a moment + + align:start position:0% +real. But now let's suppose for a moment + + + align:start position:0% +real. But now let's suppose for a moment +it's not. Then when I took this step, + + align:start position:0% +it's not. Then when I took this step, + + + align:start position:0% +it's not. Then when I took this step, +what should I have? + + align:start position:0% +what should I have? + + + align:start position:0% +what should I have? +What did I do on that step? I + + align:start position:0% +What did I do on that step? I + + + align:start position:0% +What did I do on that step? I +transposed. So I should have a bar + + align:start position:0% +transposed. So I should have a bar + + + align:start position:0% +transposed. So I should have a bar +transpose. + + align:start position:0% + + + + align:start position:0% + +In the symmetric case, that was a and + + align:start position:0% +In the symmetric case, that was a and + + + align:start position:0% +In the symmetric case, that was a and +that's what made everything work, right? + + align:start position:0% +that's what made everything work, right? + + + align:start position:0% +that's what made everything work, right? +This this led immediately to that. + + align:start position:0% +This this led immediately to that. + + + align:start position:0% +This this led immediately to that. +This one led immediately to this when + + align:start position:0% +This one led immediately to this when + + + align:start position:0% +This one led immediately to this when +the matrix was real, so that didn't + + align:start position:0% +the matrix was real, so that didn't + + + align:start position:0% +the matrix was real, so that didn't +matter. and it was symmetric so that + + align:start position:0% +matter. and it was symmetric so that + + + align:start position:0% +matter. and it was symmetric so that +didn't matter then I got a but so now I + + align:start position:0% +didn't matter then I got a but so now I + + + align:start position:0% +didn't matter then I got a but so now I +just get to ask you suppose the matrix + + align:start position:0% +just get to ask you suppose the matrix + + + align:start position:0% +just get to ask you suppose the matrix +had been complex + + align:start position:0% +had been complex + + + align:start position:0% +had been complex +what's the right + + align:start position:0% +what's the right + + + align:start position:0% +what's the right +equivalent of si symmetry so so so the + + align:start position:0% +equivalent of si symmetry so so so the + + + align:start position:0% +equivalent of si symmetry so so so the +good matrix so here let me say good + + align:start position:0% +good matrix so here let me say good + + + align:start position:0% +good matrix so here let me say good +matrices + + align:start position:0% + + + + align:start position:0% + +by good I mean real lambdas + + align:start position:0% +by good I mean real lambdas + + + align:start position:0% +by good I mean real lambdas +and perpendicular + + align:start position:0% +and perpendicular + + + align:start position:0% +and perpendicular +x's + + align:start position:0% + + + + align:start position:0% + +and tell me now which matrices are good + + align:start position:0% +and tell me now which matrices are good + + + align:start position:0% +and tell me now which matrices are good +if they're symmet if they're if they're + + align:start position:0% +if they're symmet if they're if they're + + + align:start position:0% +if they're symmet if they're if they're +real matrices the good ones are + + align:start position:0% +real matrices the good ones are + + + align:start position:0% +real matrices the good ones are +symmetric because then everything went + + align:start position:0% +symmetric because then everything went + + + align:start position:0% +symmetric because then everything went +through so the so so the good the I'm + + align:start position:0% +through so the so so the good the I'm + + + align:start position:0% +through so the so so the good the I'm +I'm saying now what's good this is this + + align:start position:0% +I'm saying now what's good this is this + + + align:start position:0% +I'm saying now what's good this is this +is these are the good matrices they have + + align:start position:0% +is these are the good matrices they have + + + align:start position:0% +is these are the good matrices they have +real values, perpendicular igon vectors. + + align:start position:0% +real values, perpendicular igon vectors. + + + align:start position:0% +real values, perpendicular igon vectors. +Good means a equal arpose + + align:start position:0% +Good means a equal arpose + + + align:start position:0% +Good means a equal arpose +if real. + + align:start position:0% +if real. + + + align:start position:0% +if real. +Then then that was what our proof + + align:start position:0% +Then then that was what our proof + + + align:start position:0% +Then then that was what our proof +worked. But if a is complex + + align:start position:0% +worked. But if a is complex + + + align:start position:0% +worked. But if a is complex +all our proof will still work provided a + + align:start position:0% +all our proof will still work provided a + + + align:start position:0% +all our proof will still work provided a +bar transpose is a. Do you see what I'm + + align:start position:0% +bar transpose is a. Do you see what I'm + + + align:start position:0% +bar transpose is a. Do you see what I'm +saying? + + align:start position:0% +saying? + + + align:start position:0% +saying? +I'm saying if we have complex matrices + + align:start position:0% +I'm saying if we have complex matrices + + + align:start position:0% +I'm saying if we have complex matrices +and we want to say are they are they as + + align:start position:0% +and we want to say are they are they as + + + align:start position:0% +and we want to say are they are they as +good as symmetric matrices + + align:start position:0% +good as symmetric matrices + + + align:start position:0% +good as symmetric matrices +then we should not only transpose the + + align:start position:0% +then we should not only transpose the + + + align:start position:0% +then we should not only transpose the +thing but conjugate it those are good + + align:start position:0% +thing but conjugate it those are good + + + align:start position:0% +thing but conjugate it those are good +matrices + + align:start position:0% +matrices + + + align:start position:0% +matrices +and of course the most important the + + align:start position:0% +and of course the most important the + + + align:start position:0% +and of course the most important the +most important case is when they're real + + align:start position:0% +most important case is when they're real + + + align:start position:0% +most important case is when they're real +this part doesn't matter and I just have + + align:start position:0% +this part doesn't matter and I just have + + + align:start position:0% +this part doesn't matter and I just have +a= a transpose symmetric. + + align:start position:0% +a= a transpose symmetric. + + + align:start position:0% +a= a transpose symmetric. +I I'll just repeat that the good + + align:start position:0% +I I'll just repeat that the good + + + align:start position:0% +I I'll just repeat that the good +matrices if complex are these. + + align:start position:0% +matrices if complex are these. + + + align:start position:0% +matrices if complex are these. +If real + + align:start position:0% +If real + + + align:start position:0% +If real +that doesn't make any difference so I'm + + align:start position:0% +that doesn't make any difference so I'm + + + align:start position:0% +that doesn't make any difference so I'm +just saying symmetric and of course 99% + + align:start position:0% +just saying symmetric and of course 99% + + + align:start position:0% +just saying symmetric and of course 99% +of examples and applications the + + align:start position:0% +of examples and applications the + + + align:start position:0% +of examples and applications the +matrices are real and we don't have that + + align:start position:0% +matrices are real and we don't have that + + + align:start position:0% +matrices are real and we don't have that +and then symmetric is the key property. + + align:start position:0% +and then symmetric is the key property. + + + align:start position:0% +and then symmetric is the key property. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So that that's uh these main facts. Uh + + align:start position:0% +So that that's uh these main facts. Uh + + + align:start position:0% +So that that's uh these main facts. Uh +and now let me just let me just so + + align:start position:0% +and now let me just let me just so + + + align:start position:0% +and now let me just let me just so +that's this xbar transpose x. Okay. So + + align:start position:0% +that's this xbar transpose x. Okay. So + + + align:start position:0% +that's this xbar transpose x. Okay. So +I'll just uh + + align:start position:0% +I'll just uh + + + align:start position:0% +I'll just uh +write it once more in this form. So + + align:start position:0% +write it once more in this form. So + + + align:start position:0% +write it once more in this form. So +perpendicular orthonormal igon vectors + + align:start position:0% +perpendicular orthonormal igon vectors + + + align:start position:0% +perpendicular orthonormal igon vectors +real values transposes of orthonormal + + align:start position:0% +real values transposes of orthonormal + + + align:start position:0% +real values transposes of orthonormal +igon vectors + + align:start position:0% +igon vectors + + + align:start position:0% +igon vectors +that's the symmetric case a= arpose + + align:start position:0% +that's the symmetric case a= arpose + + + align:start position:0% +that's the symmetric case a= arpose +okay + + align:start position:0% +okay + + + align:start position:0% +okay +good + + align:start position:0% +good + + + align:start position:0% +good +actually + + align:start position:0% +actually + + + align:start position:0% +actually +I'll even take one more step here uh + + align:start position:0% +I'll even take one more step here uh + + + align:start position:0% +I'll even take one more step here uh +suppose + + align:start position:0% +suppose + + + align:start position:0% +suppose +I can break this down to show you really + + align:start position:0% +I can break this down to show you really + + + align:start position:0% +I can break this down to show you really +what that says about a symmetric matrix. + + align:start position:0% +what that says about a symmetric matrix. + + + align:start position:0% +what that says about a symmetric matrix. +I can break that down. Let me here here + + align:start position:0% +I can break that down. Let me here here + + + align:start position:0% +I can break that down. Let me here here +go these igen vectors. I + + align:start position:0% +go these igen vectors. I + + + align:start position:0% +go these igen vectors. I +here go these igen values lambda 1 + + align:start position:0% +here go these igen values lambda 1 + + + align:start position:0% +here go these igen values lambda 1 +lambda 2 and so on. Here go these + + align:start position:0% +lambda 2 and so on. Here go these + + + align:start position:0% +lambda 2 and so on. Here go these +vectors transposed. + + align:start position:0% + + + + align:start position:0% + +And what happens if I actually do out + + align:start position:0% +And what happens if I actually do out + + + align:start position:0% +And what happens if I actually do out +that multiplication? + + align:start position:0% +that multiplication? + + + align:start position:0% +that multiplication? +Do you see what will happen? Uh there's + + align:start position:0% +Do you see what will happen? Uh there's + + + align:start position:0% +Do you see what will happen? Uh there's +lambda 1 * q1 transpose. + + align:start position:0% +lambda 1 * q1 transpose. + + + align:start position:0% +lambda 1 * q1 transpose. +So the first row here is just lambda 1 + + align:start position:0% +So the first row here is just lambda 1 + + + align:start position:0% +So the first row here is just lambda 1 +q1 transpose. If I multiply column times + + align:start position:0% +q1 transpose. If I multiply column times + + + align:start position:0% +q1 transpose. If I multiply column times +row, you remember I could do that when I + + align:start position:0% +row, you remember I could do that when I + + + align:start position:0% +row, you remember I could do that when I +multiply matrices. I can multiply + + align:start position:0% +multiply matrices. I can multiply + + + align:start position:0% +multiply matrices. I can multiply +columns + + align:start position:0% +columns + + + align:start position:0% +columns +times rows. So when I do that I get + + align:start position:0% +times rows. So when I do that I get + + + align:start position:0% +times rows. So when I do that I get +lambda one and then the column and then + + align:start position:0% +lambda one and then the column and then + + + align:start position:0% +lambda one and then the column and then +the row + + align:start position:0% +the row + + + align:start position:0% +the row +and then lambda 2 and the column and the + + align:start position:0% +and then lambda 2 and the column and the + + + align:start position:0% +and then lambda 2 and the column and the +row. + + align:start position:0% + + + + align:start position:0% + +Every symmetric matrix breaks up into + + align:start position:0% +Every symmetric matrix breaks up into + + + align:start position:0% +Every symmetric matrix breaks up into +these pieces. + + align:start position:0% +these pieces. + + + align:start position:0% +these pieces. +So these pieces have real lambdas + + align:start position:0% +So these pieces have real lambdas + + + align:start position:0% +So these pieces have real lambdas +and they have + + align:start position:0% +and they have + + + align:start position:0% +and they have +these igen these orthonormal igen + + align:start position:0% +these igen these orthonormal igen + + + align:start position:0% +these igen these orthonormal igen +vectors + + align:start position:0% + + + + align:start position:0% + +and maybe you even could tell me what + + align:start position:0% +and maybe you even could tell me what + + + align:start position:0% +and maybe you even could tell me what +kind of a matrix have I got there. + + align:start position:0% +kind of a matrix have I got there. + + + align:start position:0% +kind of a matrix have I got there. +Suppose I take a unit vector + + align:start position:0% +Suppose I take a unit vector + + + align:start position:0% +Suppose I take a unit vector +times its transpose. So column times row + + align:start position:0% +times its transpose. So column times row + + + align:start position:0% +times its transpose. So column times row +I'm getting a matrix + + align:start position:0% +I'm getting a matrix + + + align:start position:0% +I'm getting a matrix +that's a matrix with a special name. + + align:start position:0% +that's a matrix with a special name. + + + align:start position:0% +that's a matrix with a special name. +What's it what kind of a matrix is it? + + align:start position:0% +What's it what kind of a matrix is it? + + + align:start position:0% +What's it what kind of a matrix is it? +We've seen those matrices now in chapter + + align:start position:0% +We've seen those matrices now in chapter + + + align:start position:0% +We've seen those matrices now in chapter +4. It's this a transpose + + align:start position:0% +4. It's this a transpose + + + align:start position:0% +4. It's this a transpose +with a unit vector. So I don't have to + + align:start position:0% +with a unit vector. So I don't have to + + + align:start position:0% +with a unit vector. So I don't have to +divide by a transpose a. That matrix is + + align:start position:0% +divide by a transpose a. That matrix is + + + align:start position:0% +divide by a transpose a. That matrix is +a + + align:start position:0% +a + + + align:start position:0% +a +projection matrix. That's a projection + + align:start position:0% +projection matrix. That's a projection + + + align:start position:0% +projection matrix. That's a projection +matrix. It's symmetric + + align:start position:0% +matrix. It's symmetric + + + align:start position:0% +matrix. It's symmetric +and if I square it there'll be another + + align:start position:0% +and if I square it there'll be another + + + align:start position:0% +and if I square it there'll be another +there'll be a Q1 transpose Q1 which is + + align:start position:0% +there'll be a Q1 transpose Q1 which is + + + align:start position:0% +there'll be a Q1 transpose Q1 which is +one. So I'll get that matrix back again. + + align:start position:0% +one. So I'll get that matrix back again. + + + align:start position:0% +one. So I'll get that matrix back again. +Every so every symmetric matrix every + + align:start position:0% +Every so every symmetric matrix every + + + align:start position:0% +Every so every symmetric matrix every +symmetric + + align:start position:0% +symmetric + + + align:start position:0% +symmetric +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +is + + align:start position:0% +is + + + align:start position:0% +is +a combination of + + align:start position:0% +a combination of + + + align:start position:0% +a combination of +of mutually perpendicular. So + + align:start position:0% +of mutually perpendicular. So + + + align:start position:0% +of mutually perpendicular. So +perpendicular + + align:start position:0% +perpendicular + + + align:start position:0% +perpendicular +projection matrices. + + align:start position:0% +projection matrices. + + + align:start position:0% +projection matrices. +Projection + + align:start position:0% +Projection + + + align:start position:0% +Projection +matrices. + + align:start position:0% +matrices. + + + align:start position:0% +matrices. +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +that's another way that people like to + + align:start position:0% +that's another way that people like to + + + align:start position:0% +that's another way that people like to +think of the + + align:start position:0% +think of the + + + align:start position:0% +think of the +spectral theorem that every symmetric + + align:start position:0% +spectral theorem that every symmetric + + + align:start position:0% +spectral theorem that every symmetric +matrix can be broken up that way. That I + + align:start position:0% +matrix can be broken up that way. That I + + + align:start position:0% +matrix can be broken up that way. That I +guess at this moment first I haven't + + align:start position:0% +guess at this moment first I haven't + + + align:start position:0% +guess at this moment first I haven't +done an example. I could create a + + align:start position:0% +done an example. I could create a + + + align:start position:0% +done an example. I could create a +symmetric matrix + + align:start position:0% +symmetric matrix + + + align:start position:0% +symmetric matrix +check that it's find its igen values + + align:start position:0% +check that it's find its igen values + + + align:start position:0% +check that it's find its igen values +they would come out real find its igen + + align:start position:0% +they would come out real find its igen + + + align:start position:0% +they would come out real find its igen +vectors they would come out + + align:start position:0% +vectors they would come out + + + align:start position:0% +vectors they would come out +perpendicular and you would see it in + + align:start position:0% +perpendicular and you would see it in + + + align:start position:0% +perpendicular and you would see it in +numbers but maybe I'll leave it here for + + align:start position:0% +numbers but maybe I'll leave it here for + + + align:start position:0% +numbers but maybe I'll leave it here for +the moment in letters + + align:start position:0% +the moment in letters + + + align:start position:0% +the moment in letters +oh I maybe I will do it with numbers for + + align:start position:0% +oh I maybe I will do it with numbers for + + + align:start position:0% +oh I maybe I will do it with numbers for +this reason because there's one more + + align:start position:0% +this reason because there's one more + + + align:start position:0% +this reason because there's one more +remarkable fact + + align:start position:0% +remarkable fact + + + align:start position:0% +remarkable fact +can I just put this further great fact + + align:start position:0% +can I just put this further great fact + + + align:start position:0% +can I just put this further great fact +about symmetric matrices on the board. + + align:start position:0% + + + + align:start position:0% + +When I have symmetric matrices, I know + + align:start position:0% +When I have symmetric matrices, I know + + + align:start position:0% +When I have symmetric matrices, I know +their values are real. + + align:start position:0% +their values are real. + + + align:start position:0% +their values are real. +So then I can get interested in the + + align:start position:0% +So then I can get interested in the + + + align:start position:0% +So then I can get interested in the +question, are they positive or negative? + + align:start position:0% +question, are they positive or negative? + + + align:start position:0% +question, are they positive or negative? +And you remember why that's important + + align:start position:0% +And you remember why that's important + + + align:start position:0% +And you remember why that's important +for differential equations that decides + + align:start position:0% +for differential equations that decides + + + align:start position:0% +for differential equations that decides +between instability and stability. + + align:start position:0% +between instability and stability. + + + align:start position:0% +between instability and stability. +So I'm after I know they're real, then + + align:start position:0% +So I'm after I know they're real, then + + + align:start position:0% +So I'm after I know they're real, then +the next question is are they positive? + + align:start position:0% +the next question is are they positive? + + + align:start position:0% +the next question is are they positive? +Are they negative? + + align:start position:0% +Are they negative? + + + align:start position:0% +Are they negative? +And + + align:start position:0% +And + + + align:start position:0% +And +I hate to have to compute those + + align:start position:0% +I hate to have to compute those + + + align:start position:0% +I hate to have to compute those +igen values to answer that question, + + align:start position:0% +igen values to answer that question, + + + align:start position:0% +igen values to answer that question, +right? Because computing the igen values + + align:start position:0% +right? Because computing the igen values + + + align:start position:0% +right? Because computing the igen values +of a symmetric matrix of order let's say + + align:start position:0% +of a symmetric matrix of order let's say + + + align:start position:0% +of a symmetric matrix of order let's say +50 computed 50 values + + align:start position:0% +50 computed 50 values + + + align:start position:0% +50 computed 50 values +is a job. + + align:start position:0% +is a job. + + + align:start position:0% +is a job. +I mean by pencil and paper it's a + + align:start position:0% +I mean by pencil and paper it's a + + + align:start position:0% +I mean by pencil and paper it's a +lifetimes job. I mean which and in fact + + align:start position:0% +lifetimes job. I mean which and in fact + + + align:start position:0% +lifetimes job. I mean which and in fact +um + + align:start position:0% +um + + + align:start position:0% +um +a few years ago well say 20 years ago or + + align:start position:0% +a few years ago well say 20 years ago or + + + align:start position:0% +a few years ago well say 20 years ago or +30 nobody really knew how to do it. I + + align:start position:0% +30 nobody really knew how to do it. I + + + align:start position:0% +30 nobody really knew how to do it. I +mean so like science was stuck on this + + align:start position:0% +mean so like science was stuck on this + + + align:start position:0% +mean so like science was stuck on this +problem. If you have a matrix of order + + align:start position:0% +problem. If you have a matrix of order + + + align:start position:0% +problem. If you have a matrix of order +50 or 100 how do you find its igen + + align:start position:0% +50 or 100 how do you find its igen + + + align:start position:0% +50 or 100 how do you find its igen +values + + align:start position:0% +values + + + align:start position:0% +values +numerically? Now, I'm just saying + + align:start position:0% +numerically? Now, I'm just saying + + + align:start position:0% +numerically? Now, I'm just saying +because pencil and paper is we're going + + align:start position:0% +because pencil and paper is we're going + + + align:start position:0% +because pencil and paper is we're going +to run out of time or paper or something + + align:start position:0% +to run out of time or paper or something + + + align:start position:0% +to run out of time or paper or something +before we get it. + + align:start position:0% +before we get it. + + + align:start position:0% +before we get it. +Um, well, and you might think, okay, get + + align:start position:0% +Um, well, and you might think, okay, get + + + align:start position:0% +Um, well, and you might think, okay, get +the get get mat lab to compute the + + align:start position:0% +the get get mat lab to compute the + + + align:start position:0% +the get get mat lab to compute the +determinant of lambda minus a a minus + + align:start position:0% +determinant of lambda minus a a minus + + + align:start position:0% +determinant of lambda minus a a minus +lambda i this polomial of 50th degree + + align:start position:0% +lambda i this polomial of 50th degree + + + align:start position:0% +lambda i this polomial of 50th degree +and then find the roots. + + align:start position:0% +and then find the roots. + + + align:start position:0% +and then find the roots. +uh mat lab will do it but it will + + align:start position:0% +uh mat lab will do it but it will + + + align:start position:0% +uh mat lab will do it but it will +complain + + align:start position:0% +complain + + + align:start position:0% +complain +uh because it's a very bad way to find + + align:start position:0% +uh because it's a very bad way to find + + + align:start position:0% +uh because it's a very bad way to find +the igen values. I I I'm sorry to be + + align:start position:0% +the igen values. I I I'm sorry to be + + + align:start position:0% +the igen values. I I I'm sorry to be +saying this because it's the way I + + align:start position:0% +saying this because it's the way I + + + align:start position:0% +saying this because it's the way I +taught you to do it right. I taught you + + align:start position:0% +taught you to do it right. I taught you + + + align:start position:0% +taught you to do it right. I taught you +to find the igen values by doing that + + align:start position:0% +to find the igen values by doing that + + + align:start position:0% +to find the igen values by doing that +determinant and taking the roots of that + + align:start position:0% +determinant and taking the roots of that + + + align:start position:0% +determinant and taking the roots of that +polomial. But now I'm saying, okay, I + + align:start position:0% +polomial. But now I'm saying, okay, I + + + align:start position:0% +polomial. But now I'm saying, okay, I +really meant that for 2 by twos and 3 + + align:start position:0% +really meant that for 2 by twos and 3 + + + align:start position:0% +really meant that for 2 by twos and 3 +by3s, but I didn't mean you to do it on + + align:start position:0% +by3s, but I didn't mean you to do it on + + + align:start position:0% +by3s, but I didn't mean you to do it on +a 50 by 50. And + + align:start position:0% +a 50 by 50. And + + + align:start position:0% +a 50 by 50. And +you're not too unhappy probably because + + align:start position:0% +you're not too unhappy probably because + + + align:start position:0% +you're not too unhappy probably because +you didn't want to do it. But good + + align:start position:0% +you didn't want to do it. But good + + + align:start position:0% +you didn't want to do it. But good +because + + align:start position:0% +because + + + align:start position:0% +because +it would be a very unstable way. The the + + align:start position:0% +it would be a very unstable way. The the + + + align:start position:0% +it would be a very unstable way. The the +50 answers that would come out would be + + align:start position:0% +50 answers that would come out would be + + + align:start position:0% +50 answers that would come out would be +highly unreliable. So uh new ways are + + align:start position:0% +highly unreliable. So uh new ways are + + + align:start position:0% +highly unreliable. So uh new ways are +are much better to find those 50 values. + + align:start position:0% +are much better to find those 50 values. + + + align:start position:0% +are much better to find those 50 values. +That's a that's a part of numerical + + align:start position:0% +That's a that's a part of numerical + + + align:start position:0% +That's a that's a part of numerical +linear algebra. + + align:start position:0% +linear algebra. + + + align:start position:0% +linear algebra. +But here's the remarkable fact + + align:start position:0% +But here's the remarkable fact + + + align:start position:0% +But here's the remarkable fact +that mat lab would quite happily find + + align:start position:0% +that mat lab would quite happily find + + + align:start position:0% +that mat lab would quite happily find +the 50 pivots. + + align:start position:0% +the 50 pivots. + + + align:start position:0% +the 50 pivots. +Right? Now the pivots are not the same + + align:start position:0% +Right? Now the pivots are not the same + + + align:start position:0% +Right? Now the pivots are not the same +as the igen values. + + align:start position:0% +as the igen values. + + + align:start position:0% +as the igen values. +But here's the great thing. If if I had + + align:start position:0% +But here's the great thing. If if I had + + + align:start position:0% +But here's the great thing. If if I had +a real matrix, I could find those 50 + + align:start position:0% +a real matrix, I could find those 50 + + + align:start position:0% +a real matrix, I could find those 50 +pivots and I could see maybe 28 of them + + align:start position:0% +pivots and I could see maybe 28 of them + + + align:start position:0% +pivots and I could see maybe 28 of them +are positive and 22 or negative pivots + + align:start position:0% +are positive and 22 or negative pivots + + + align:start position:0% +are positive and 22 or negative pivots +and I can compute those safely and + + align:start position:0% +and I can compute those safely and + + + align:start position:0% +and I can compute those safely and +quickly. And the great fact is that 28 + + align:start position:0% +quickly. And the great fact is that 28 + + + align:start position:0% +quickly. And the great fact is that 28 +of the igen values would be positive and + + align:start position:0% +of the igen values would be positive and + + + align:start position:0% +of the igen values would be positive and +22 would be negative that the signs of + + align:start position:0% +22 would be negative that the signs of + + + align:start position:0% +22 would be negative that the signs of +the pivots. So this is like a just I + + align:start position:0% +the pivots. So this is like a just I + + + align:start position:0% +the pivots. So this is like a just I +hope you think this this is kind of a + + align:start position:0% +hope you think this this is kind of a + + + align:start position:0% +hope you think this this is kind of a +nice thing that the signs of the pivots + + align:start position:0% + + + + align:start position:0% + +for symmetric I'm always talking about + + align:start position:0% +for symmetric I'm always talking about + + + align:start position:0% +for symmetric I'm always talking about +symmetric matrices. So I really like + + align:start position:0% +symmetric matrices. So I really like + + + align:start position:0% +symmetric matrices. So I really like +trying to convince you that symmetric + + align:start position:0% +trying to convince you that symmetric + + + align:start position:0% +trying to convince you that symmetric +matrices are better than the rest. So + + align:start position:0% +matrices are better than the rest. So + + + align:start position:0% +matrices are better than the rest. So +the signs of the pivots + + align:start position:0% +the signs of the pivots + + + align:start position:0% +the signs of the pivots +are same as + + align:start position:0% + + + + align:start position:0% + +the signs + + align:start position:0% +the signs + + + align:start position:0% +the signs +of the igen values. + + align:start position:0% +of the igen values. + + + align:start position:0% +of the igen values. +The same number + + align:start position:0% +The same number + + + align:start position:0% +The same number +the number of + + align:start position:0% +the number of + + + align:start position:0% +the number of +pivots greater than zero. + + align:start position:0% +pivots greater than zero. + + + align:start position:0% +pivots greater than zero. +The number of positive pivots + + align:start position:0% +The number of positive pivots + + + align:start position:0% +The number of positive pivots +is equal to the number of positive + + align:start position:0% + + + + align:start position:0% + +igen values. + + align:start position:0% +igen values. + + + align:start position:0% +igen values. +So that actually is a very useful that + + align:start position:0% +So that actually is a very useful that + + + align:start position:0% +So that actually is a very useful that +gives you a a a good start on a decent + + align:start position:0% +gives you a a a good start on a decent + + + align:start position:0% +gives you a a a good start on a decent +way to compute values + + align:start position:0% +way to compute values + + + align:start position:0% +way to compute values +because you can narrow them down. You + + align:start position:0% +because you can narrow them down. You + + + align:start position:0% +because you can narrow them down. You +can find out how many are positive, how + + align:start position:0% +can find out how many are positive, how + + + align:start position:0% +can find out how many are positive, how +many are negative. Then you could shift + + align:start position:0% +many are negative. Then you could shift + + + align:start position:0% +many are negative. Then you could shift +the matrix by seven times the identity. + + align:start position:0% +the matrix by seven times the identity. + + + align:start position:0% +the matrix by seven times the identity. +That would shift all the igen values by + + align:start position:0% +That would shift all the igen values by + + + align:start position:0% +That would shift all the igen values by +seven. + + align:start position:0% +seven. + + + align:start position:0% +seven. +Then you could take the pivots of that + + align:start position:0% +Then you could take the pivots of that + + + align:start position:0% +Then you could take the pivots of that +matrix and you would know how many igen + + align:start position:0% +matrix and you would know how many igen + + + align:start position:0% +matrix and you would know how many igen +values + + align:start position:0% +values + + + align:start position:0% +values +of the original were above seven and + + align:start position:0% +of the original were above seven and + + + align:start position:0% +of the original were above seven and +below seven. So this this neat little + + align:start position:0% +below seven. So this this neat little + + + align:start position:0% +below seven. So this this neat little +theorem that the symmetric matrices + + align:start position:0% +theorem that the symmetric matrices + + + align:start position:0% +theorem that the symmetric matrices +have this connection between nobody's + + align:start position:0% +have this connection between nobody's + + + align:start position:0% +have this connection between nobody's +mixing up and thinking the pivots are + + align:start position:0% +mixing up and thinking the pivots are + + + align:start position:0% +mixing up and thinking the pivots are +the igen values. + + align:start position:0% +the igen values. + + + align:start position:0% +the igen values. +I mean the only thing I can think of is + + align:start position:0% +I mean the only thing I can think of is + + + align:start position:0% +I mean the only thing I can think of is +the product of the pivots equals the + + align:start position:0% +the product of the pivots equals the + + + align:start position:0% +the product of the pivots equals the +product of the igen values. Why is that? + + align:start position:0% +product of the igen values. Why is that? + + + align:start position:0% +product of the igen values. Why is that? +So if I asked you for the reason on + + align:start position:0% +So if I asked you for the reason on + + + align:start position:0% +So if I asked you for the reason on +that, why is the product of the pivots + + align:start position:0% +that, why is the product of the pivots + + + align:start position:0% +that, why is the product of the pivots +for a symmetric matrix the same as the + + align:start position:0% +for a symmetric matrix the same as the + + + align:start position:0% +for a symmetric matrix the same as the +product of the igen values? + + align:start position:0% +product of the igen values? + + + align:start position:0% +product of the igen values? +Because they both equal + + align:start position:0% + + + + align:start position:0% + +the determinant, right? The product of + + align:start position:0% +the determinant, right? The product of + + + align:start position:0% +the determinant, right? The product of +the pivots gives the determinant if no + + align:start position:0% +the pivots gives the determinant if no + + + align:start position:0% +the pivots gives the determinant if no +row exchanges. The product of the igen + + align:start position:0% +row exchanges. The product of the igen + + + align:start position:0% +row exchanges. The product of the igen +values always gives the determinant. So, + + align:start position:0% +values always gives the determinant. So, + + + align:start position:0% +values always gives the determinant. So, +so the products, but that doesn't tell + + align:start position:0% +so the products, but that doesn't tell + + + align:start position:0% +so the products, but that doesn't tell +you anything about the 50 individual + + align:start position:0% +you anything about the 50 individual + + + align:start position:0% +you anything about the 50 individual +ones, which this does. Okay. So, that's + + align:start position:0% +ones, which this does. Okay. So, that's + + + align:start position:0% +ones, which this does. Okay. So, that's +uh those are essential facts about + + align:start position:0% +uh those are essential facts about + + + align:start position:0% +uh those are essential facts about +symmetric matrices. + + align:start position:0% +symmetric matrices. + + + align:start position:0% +symmetric matrices. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now, I I said in the in the lecture + + align:start position:0% +Now, I I said in the in the lecture + + + align:start position:0% +Now, I I said in the in the lecture +description that I would + + align:start position:0% +description that I would + + + align:start position:0% +description that I would +take the last minutes to start on + + align:start position:0% +take the last minutes to start on + + + align:start position:0% +take the last minutes to start on +positive definite matrices because we're + + align:start position:0% +positive definite matrices because we're + + + align:start position:0% +positive definite matrices because we're +right there. We're we're we're we're uh + + align:start position:0% +right there. We're we're we're we're uh + + + align:start position:0% +right there. We're we're we're we're uh +we're ready to say what's a positive + + align:start position:0% +we're ready to say what's a positive + + + align:start position:0% +we're ready to say what's a positive +definite matrix. + + align:start position:0% + + + + align:start position:0% + +It's symmetric. First of all, + + align:start position:0% +It's symmetric. First of all, + + + align:start position:0% +It's symmetric. First of all, +I'm always I will mean symmetric. + + align:start position:0% + + + + align:start position:0% + +So this is the this is the next section + + align:start position:0% +So this is the this is the next section + + + align:start position:0% +So this is the this is the next section +of the book. It's about this. If + + align:start position:0% +of the book. It's about this. If + + + align:start position:0% +of the book. It's about this. If +symmetric matrices are good, which is + + align:start position:0% +symmetric matrices are good, which is + + + align:start position:0% +symmetric matrices are good, which is +like the point of my lecture so far, + + align:start position:0% +like the point of my lecture so far, + + + align:start position:0% +like the point of my lecture so far, +then positive definite matrices + + align:start position:0% +then positive definite matrices + + + align:start position:0% +then positive definite matrices +are + + align:start position:0% +are + + + align:start position:0% +are +uh subclass that are + + align:start position:0% +uh subclass that are + + + align:start position:0% +uh subclass that are +excellent. Okay, just the greatest. + + align:start position:0% +excellent. Okay, just the greatest. + + + align:start position:0% +excellent. Okay, just the greatest. +So what are they? + + align:start position:0% +So what are they? + + + align:start position:0% +So what are they? +They're matrices. They're symmetric + + align:start position:0% +They're matrices. They're symmetric + + + align:start position:0% +They're matrices. They're symmetric +matrices. So all their igen values are + + align:start position:0% +matrices. So all their igen values are + + + align:start position:0% +matrices. So all their igen values are +real. You can guess what they are. + + align:start position:0% +real. You can guess what they are. + + + align:start position:0% +real. You can guess what they are. +These are symmetric matrices with all + + align:start position:0% +These are symmetric matrices with all + + + align:start position:0% +These are symmetric matrices with all +the igen values are + + align:start position:0% + + + + align:start position:0% + +okay. Tell me what to write. + + align:start position:0% + + + + align:start position:0% + +What? Well, it it it's hinted of course + + align:start position:0% +What? Well, it it it's hinted of course + + + align:start position:0% +What? Well, it it it's hinted of course +by the name for these things. All the en + + align:start position:0% +by the name for these things. All the en + + + align:start position:0% +by the name for these things. All the en +values are positive. + + align:start position:0% +values are positive. + + + align:start position:0% +values are positive. +Okay. + + align:start position:0% + + + + align:start position:0% + +Tell me about the pivots. We can check + + align:start position:0% +Tell me about the pivots. We can check + + + align:start position:0% +Tell me about the pivots. We can check +the igen values or we can check the + + align:start position:0% +the igen values or we can check the + + + align:start position:0% +the igen values or we can check the +pivots. All the pivots + + align:start position:0% +pivots. All the pivots + + + align:start position:0% +pivots. All the pivots +are what? + + align:start position:0% + + + + align:start position:0% + +And then I'll then I'll finally give an + + align:start position:0% +And then I'll then I'll finally give an + + + align:start position:0% +And then I'll then I'll finally give an +example. I feel awful that I have got to + + align:start position:0% +example. I feel awful that I have got to + + + align:start position:0% +example. I feel awful that I have got to +this point in the lecture and I haven't + + align:start position:0% +this point in the lecture and I haven't + + + align:start position:0% +this point in the lecture and I haven't +given you a single example. So let me + + align:start position:0% +given you a single example. So let me + + + align:start position:0% +given you a single example. So let me +give you one. 5 3 22 + + align:start position:0% +give you one. 5 3 22 + + + align:start position:0% +give you one. 5 3 22 +at symmetric + + align:start position:0% +at symmetric + + + align:start position:0% +at symmetric +fine its igen values are real for sure + + align:start position:0% +fine its igen values are real for sure + + + align:start position:0% +fine its igen values are real for sure +but more than that + + align:start position:0% +but more than that + + + align:start position:0% +but more than that +I know the signs of those igen values + + align:start position:0% +I know the signs of those igen values + + + align:start position:0% +I know the signs of those igen values +and also I know the signs of those + + align:start position:0% +and also I know the signs of those + + + align:start position:0% +and also I know the signs of those +pivots. So what's the deal with the + + align:start position:0% +pivots. So what's the deal with the + + + align:start position:0% +pivots. So what's the deal with the +pivots? the I if the igen values are all + + align:start position:0% +pivots? the I if the igen values are all + + + align:start position:0% +pivots? the I if the igen values are all +positive and if this little fact is true + + align:start position:0% +positive and if this little fact is true + + + align:start position:0% +positive and if this little fact is true +that the pivots and and values have the + + align:start position:0% +that the pivots and and values have the + + + align:start position:0% +that the pivots and and values have the +same signs then this must be true all + + align:start position:0% +same signs then this must be true all + + + align:start position:0% +same signs then this must be true all +the pivots are positive + + align:start position:0% + + + + align:start position:0% + +and that's the good way to test this is + + align:start position:0% +and that's the good way to test this is + + + align:start position:0% +and that's the good way to test this is +the good test because I could what are + + align:start position:0% +the good test because I could what are + + + align:start position:0% +the good test because I could what are +the pivots for that matrix + + align:start position:0% +the pivots for that matrix + + + align:start position:0% +the pivots for that matrix +the pivots for that matrix are five so + + align:start position:0% +the pivots for that matrix are five so + + + align:start position:0% +the pivots for that matrix are five so +pivots are + + align:start position:0% + + + + align:start position:0% + +five and what's the second pivot? Have + + align:start position:0% +five and what's the second pivot? Have + + + align:start position:0% +five and what's the second pivot? Have +we like noticed the formula for the + + align:start position:0% +we like noticed the formula for the + + + align:start position:0% +we like noticed the formula for the +second pivot in a matrix? + + align:start position:0% + + + + align:start position:0% + +It doesn't necessarily, you know, it may + + align:start position:0% +It doesn't necessarily, you know, it may + + + align:start position:0% +It doesn't necessarily, you know, it may +come out a fraction for sure, but what + + align:start position:0% +come out a fraction for sure, but what + + + align:start position:0% +come out a fraction for sure, but what +is that fraction? Can you tell me? Well, + + align:start position:0% +is that fraction? Can you tell me? Well, + + + align:start position:0% +is that fraction? Can you tell me? Well, +here the product of the pivots is the + + align:start position:0% +here the product of the pivots is the + + + align:start position:0% +here the product of the pivots is the +determinant. What's the determinant of + + align:start position:0% +determinant. What's the determinant of + + + align:start position:0% +determinant. What's the determinant of +this matrix? + + align:start position:0% + + + + align:start position:0% + +11. + + align:start position:0% +11. + + + align:start position:0% +11. +So the second pivot must be 11 over 5. + + align:start position:0% +So the second pivot must be 11 over 5. + + + align:start position:0% +So the second pivot must be 11 over 5. +So that the product is 11. + + align:start position:0% +So that the product is 11. + + + align:start position:0% +So that the product is 11. +They're both positive. + + align:start position:0% +They're both positive. + + + align:start position:0% +They're both positive. +Then I know that the igen values of that + + align:start position:0% +Then I know that the igen values of that + + + align:start position:0% +Then I know that the igen values of that +matrix are both positive. What are the + + align:start position:0% +matrix are both positive. What are the + + + align:start position:0% +matrix are both positive. What are the +igen values? Well, I've got to take the + + align:start position:0% +igen values? Well, I've got to take the + + + align:start position:0% +igen values? Well, I've got to take the +roots of, you know, do I put in a minus + + align:start position:0% +roots of, you know, do I put in a minus + + + align:start position:0% +roots of, you know, do I put in a minus +lambda? You mentally do this. lambda + + align:start position:0% +lambda? You mentally do this. lambda + + + align:start position:0% +lambda? You mentally do this. lambda +squared minus how many lambdas + + align:start position:0% +squared minus how many lambdas + + + align:start position:0% +squared minus how many lambdas +eight right five and three the trace + + align:start position:0% +eight right five and three the trace + + + align:start position:0% +eight right five and three the trace +comes in there plus what number comes + + align:start position:0% +comes in there plus what number comes + + + align:start position:0% +comes in there plus what number comes +here the determinant the 11 so I set + + align:start position:0% +here the determinant the 11 so I set + + + align:start position:0% +here the determinant the 11 so I set +that to zero + + align:start position:0% +that to zero + + + align:start position:0% +that to zero +so the igen values are + + align:start position:0% +so the igen values are + + + align:start position:0% +so the igen values are +let's see half of that is four look at + + align:start position:0% +let's see half of that is four look at + + + align:start position:0% +let's see half of that is four look at +that positive number plus or minus the + + align:start position:0% +that positive number plus or minus the + + + align:start position:0% +that positive number plus or minus the +square<unk> of 16 - 11 I think five + + align:start position:0% + + + + align:start position:0% + +the values well 2 by two they're not so + + align:start position:0% +the values well 2 by two they're not so + + + align:start position:0% +the values well 2 by two they're not so +terrible but they're not so perfect + + align:start position:0% +terrible but they're not so perfect + + + align:start position:0% +terrible but they're not so perfect +pivots are really simple + + align:start position:0% + + + + align:start position:0% + +and this is uh this is the family of + + align:start position:0% +and this is uh this is the family of + + + align:start position:0% +and this is uh this is the family of +matrices that you really want in + + align:start position:0% +matrices that you really want in + + + align:start position:0% +matrices that you really want in +differential equations because uh you + + align:start position:0% +differential equations because uh you + + + align:start position:0% +differential equations because uh you +know the signs of the igen values so you + + align:start position:0% +know the signs of the igen values so you + + + align:start position:0% +know the signs of the igen values so you +know the stability or Not okay. Uh + + align:start position:0% +know the stability or Not okay. Uh + + + align:start position:0% +know the stability or Not okay. Uh +there's one other related fact I can pop + + align:start position:0% +there's one other related fact I can pop + + + align:start position:0% +there's one other related fact I can pop +in here in in the time available for + + align:start position:0% +in here in in the time available for + + + align:start position:0% +in here in in the time available for +positive definite matrices. + + align:start position:0% +positive definite matrices. + + + align:start position:0% +positive definite matrices. +The the related fact is to ask you about + + align:start position:0% +The the related fact is to ask you about + + + align:start position:0% +The the related fact is to ask you about +determinants. + + align:start position:0% +determinants. + + + align:start position:0% +determinants. +So what's the determinant? + + align:start position:0% + + + + align:start position:0% + +What can you tell me if I remember + + align:start position:0% +What can you tell me if I remember + + + align:start position:0% +What can you tell me if I remember +positive definite means all values are + + align:start position:0% +positive definite means all values are + + + align:start position:0% +positive definite means all values are +positive all pivots are positive so what + + align:start position:0% +positive all pivots are positive so what + + + align:start position:0% +positive all pivots are positive so what +can you tell me about the determinant + + align:start position:0% +can you tell me about the determinant + + + align:start position:0% +can you tell me about the determinant +it's positive too + + align:start position:0% +it's positive too + + + align:start position:0% +it's positive too +but somehow that that's not quite enough + + align:start position:0% +but somehow that that's not quite enough + + + align:start position:0% +but somehow that that's not quite enough +here here's a matrix -1 + + align:start position:0% +here here's a matrix -1 + + + align:start position:0% +here here's a matrix -1 +minus3 + + align:start position:0% +minus3 + + + align:start position:0% +minus3 +what's the determinant of that guy + + align:start position:0% +what's the determinant of that guy + + + align:start position:0% +what's the determinant of that guy +It's positive, right? Is this a positive + + align:start position:0% +It's positive, right? Is this a positive + + + align:start position:0% +It's positive, right? Is this a positive +definite matrix? Are the pivots what are + + align:start position:0% +definite matrix? Are the pivots what are + + + align:start position:0% +definite matrix? Are the pivots what are +the pivots? Well, negative. + + align:start position:0% +the pivots? Well, negative. + + + align:start position:0% +the pivots? Well, negative. +What are the igen values? Well, they're + + align:start position:0% +What are the igen values? Well, they're + + + align:start position:0% +What are the igen values? Well, they're +also the same. So, + + align:start position:0% +also the same. So, + + + align:start position:0% +also the same. So, +somehow + + align:start position:0% +somehow + + + align:start position:0% +somehow +I don't just want the determinant of the + + align:start position:0% +I don't just want the determinant of the + + + align:start position:0% +I don't just want the determinant of the +whole matrix. Here is 11. That's great. + + align:start position:0% +whole matrix. Here is 11. That's great. + + + align:start position:0% +whole matrix. Here is 11. That's great. +Here, the determinant of the whole + + align:start position:0% +Here, the determinant of the whole + + + align:start position:0% +Here, the determinant of the whole +matrix is three. That's positive. + + align:start position:0% +matrix is three. That's positive. + + + align:start position:0% +matrix is three. That's positive. +I also I've got to check like little + + align:start position:0% +I also I've got to check like little + + + align:start position:0% +I also I've got to check like little +subdeterminants + + align:start position:0% +subdeterminants + + + align:start position:0% +subdeterminants +say maybe coming down from the left. So + + align:start position:0% +say maybe coming down from the left. So + + + align:start position:0% +say maybe coming down from the left. So +the one by one and the 2x two have to be + + align:start position:0% +the one by one and the 2x two have to be + + + align:start position:0% +the one by one and the 2x two have to be +positive. So there that's where I get + + align:start position:0% +positive. So there that's where I get + + + align:start position:0% +positive. So there that's where I get +the all + + align:start position:0% +the all + + + align:start position:0% +the all +all can I call them subdeterminants + + align:start position:0% +all can I call them subdeterminants + + + align:start position:0% +all can I call them subdeterminants +are see I have to I need to make that + + align:start position:0% +are see I have to I need to make that + + + align:start position:0% +are see I have to I need to make that +thing plural. I need to test n things, + + align:start position:0% +thing plural. I need to test n things, + + + align:start position:0% +thing plural. I need to test n things, +not just the big determinant. All + + align:start position:0% +not just the big determinant. All + + + align:start position:0% +not just the big determinant. All +subdeterminants are + + align:start position:0% +subdeterminants are + + + align:start position:0% +subdeterminants are +positive. Then I'm okay. + + align:start position:0% +positive. Then I'm okay. + + + align:start position:0% +positive. Then I'm okay. +Then I'm okay. This passes the test. + + align:start position:0% +Then I'm okay. This passes the test. + + + align:start position:0% +Then I'm okay. This passes the test. +Five is positive and 11 is positive. + + align:start position:0% +Five is positive and 11 is positive. + + + align:start position:0% +Five is positive and 11 is positive. +This fails the test because that minus + + align:start position:0% +This fails the test because that minus + + + align:start position:0% +This fails the test because that minus +one there is negative. + + align:start position:0% +one there is negative. + + + align:start position:0% +one there is negative. +And then the big determinant is + + align:start position:0% +And then the big determinant is + + + align:start position:0% +And then the big determinant is +positive3. + + align:start position:0% +positive3. + + + align:start position:0% +positive3. +So this + + align:start position:0% +So this + + + align:start position:0% +So this +these this fact do you see that actually + + align:start position:0% +these this fact do you see that actually + + + align:start position:0% +these this fact do you see that actually +the course like coming together + + align:start position:0% + + + + align:start position:0% + +and that's really my point now in the + + align:start position:0% +and that's really my point now in the + + + align:start position:0% +and that's really my point now in the +next in this lecture and particularly + + align:start position:0% +next in this lecture and particularly + + + align:start position:0% +next in this lecture and particularly +next Wednesday and Friday + + align:start position:0% +next Wednesday and Friday + + + align:start position:0% +next Wednesday and Friday +the course comes together these pivots + + align:start position:0% +the course comes together these pivots + + + align:start position:0% +the course comes together these pivots +that we met in the first week these + + align:start position:0% +that we met in the first week these + + + align:start position:0% +that we met in the first week these +determinants that we met in the middle + + align:start position:0% +determinants that we met in the middle + + + align:start position:0% +determinants that we met in the middle +of the course. + + align:start position:0% +of the course. + + + align:start position:0% +of the course. +These igen values that we met most + + align:start position:0% +These igen values that we met most + + + align:start position:0% +These igen values that we met most +recently all matrices are square here. + + align:start position:0% +recently all matrices are square here. + + + align:start position:0% +recently all matrices are square here. +So coming together for square matrices + + align:start position:0% +So coming together for square matrices + + + align:start position:0% +So coming together for square matrices +means these three pieces come together + + align:start position:0% +means these three pieces come together + + + align:start position:0% +means these three pieces come together +and they come together in that beautiful + + align:start position:0% +and they come together in that beautiful + + + align:start position:0% +and they come together in that beautiful +fact that if that all the that if I have + + align:start position:0% +fact that if that all the that if I have + + + align:start position:0% +fact that if that all the that if I have +one of these I have the others that if I + + align:start position:0% +one of these I have the others that if I + + + align:start position:0% +one of these I have the others that if I +but but for symmetric matrices so that + + align:start position:0% +but but for symmetric matrices so that + + + align:start position:0% +but but for symmetric matrices so that +this will be the positive definite + + align:start position:0% +this will be the positive definite + + + align:start position:0% +this will be the positive definite +section and then the real climax of the + + align:start position:0% +section and then the real climax of the + + + align:start position:0% +section and then the real climax of the +course is to make everything come + + align:start position:0% +course is to make everything come + + + align:start position:0% +course is to make everything come +together for M byN matrices + + align:start position:0% +together for M byN matrices + + + align:start position:0% +together for M byN matrices +not necessarily symmetric bring bring + + align:start position:0% +not necessarily symmetric bring bring + + + align:start position:0% +not necessarily symmetric bring bring +everything together there and that will + + align:start position:0% +everything together there and that will + + + align:start position:0% +everything together there and that will +be the final thing okay so uh have a + + align:start position:0% +be the final thing okay so uh have a + + + align:start position:0% +be the final thing okay so uh have a +great weekend and don't forget symmetric + + align:start position:0% +great weekend and don't forget symmetric + + + align:start position:0% +great weekend and don't forget symmetric +matrices thanks \ No newline at end of file diff --git a/vAuJO7rv92U.txt b/vAuJO7rv92U.txt new file mode 100644 index 0000000000000000000000000000000000000000..cc67afd0934a4dbbbe41fd7ccdb71dc31178d44b --- /dev/null +++ b/vAuJO7rv92U.txt @@ -0,0 +1,5187 @@ +align:start position:0% + +part of what I do is work with people + + align:start position:0% +part of what I do is work with people + + + align:start position:0% +part of what I do is work with people +who are preparing to be part teachers + + align:start position:0% +who are preparing to be part teachers + + + align:start position:0% +who are preparing to be part teachers +k12 our teachers work with artists I've + + align:start position:0% +k12 our teachers work with artists I've + + + align:start position:0% +k12 our teachers work with artists I've +taught studio based courses and ceramics + + align:start position:0% +taught studio based courses and ceramics + + + align:start position:0% +taught studio based courses and ceramics +drawing and also working with grad + + align:start position:0% +drawing and also working with grad + + + align:start position:0% +drawing and also working with grad +students who are interested in engaging + + align:start position:0% +students who are interested in engaging + + + align:start position:0% +students who are interested in engaging +and research about and through and + + align:start position:0% +and research about and through and + + + align:start position:0% +and research about and through and +within art practices visual culture + + align:start position:0% +within art practices visual culture + + + align:start position:0% +within art practices visual culture +practices so there's this range of folks + + align:start position:0% + + + + align:start position:0% + +so what if you're what I'm trying to + + align:start position:0% +so what if you're what I'm trying to + + + align:start position:0% +so what if you're what I'm trying to +negotiate a place to enter it Larry one + + align:start position:0% +negotiate a place to enter it Larry one + + + align:start position:0% +negotiate a place to enter it Larry one +of the things that you said was somehow + + align:start position:0% +of the things that you said was somehow + + + align:start position:0% +of the things that you said was somehow +explicit yeah am i with you know this as + + align:start position:0% +explicit yeah am i with you know this as + + + align:start position:0% +explicit yeah am i with you know this as +we've been calling it this hidden agenda + + align:start position:0% +we've been calling it this hidden agenda + + + align:start position:0% +we've been calling it this hidden agenda +right curriculum is gender nobody's the + + align:start position:0% +right curriculum is gender nobody's the + + + align:start position:0% +right curriculum is gender nobody's the +same thing right in many cases it's the + + align:start position:0% +same thing right in many cases it's the + + + align:start position:0% +same thing right in many cases it's the +same thing right because you have an + + align:start position:0% +same thing right because you have an + + + align:start position:0% +same thing right because you have an +agenda that you're trying to cover + + align:start position:0% +agenda that you're trying to cover + + + align:start position:0% +agenda that you're trying to cover +whether it's an official agenda we can + + align:start position:0% +whether it's an official agenda we can + + + align:start position:0% +whether it's an official agenda we can +correlate that to the official + + align:start position:0% +correlate that to the official + + + align:start position:0% +correlate that to the official +curriculum and I'm pulling that this + + align:start position:0% +curriculum and I'm pulling that this + + + align:start position:0% +curriculum and I'm pulling that this +term correctly these curriculum pieces + + align:start position:0% +term correctly these curriculum pieces + + + align:start position:0% +term correctly these curriculum pieces +from the work of George Posner and + + align:start position:0% +from the work of George Posner and + + + align:start position:0% +from the work of George Posner and +others right where you might consider + + align:start position:0% +others right where you might consider + + + align:start position:0% +others right where you might consider +their five kinds of curriculum that are + + align:start position:0% +their five kinds of curriculum that are + + + align:start position:0% +their five kinds of curriculum that are +happening at the same time five + + align:start position:0% +happening at the same time five + + + align:start position:0% +happening at the same time five +concurrent curricula he says there's the + + align:start position:0% +concurrent curricula he says there's the + + + align:start position:0% +concurrent curricula he says there's the +official curriculum which is what it's + + align:start position:0% +official curriculum which is what it's + + + align:start position:0% +official curriculum which is what it's +written down is that officially mandated + + align:start position:0% +written down is that officially mandated + + + align:start position:0% +written down is that officially mandated +this is what will be taught then there's + + align:start position:0% +this is what will be taught then there's + + + align:start position:0% +this is what will be taught then there's +the operational curriculum it's what you + + align:start position:0% +the operational curriculum it's what you + + + align:start position:0% +the operational curriculum it's what you +put into practice tank operationalize it + + align:start position:0% +put into practice tank operationalize it + + + align:start position:0% +put into practice tank operationalize it +okay so you could be the official agenda + + align:start position:0% +okay so you could be the official agenda + + + align:start position:0% +okay so you could be the official agenda +than the operationalized agenda so + + align:start position:0% +than the operationalized agenda so + + + align:start position:0% +than the operationalized agenda so +agenda and curriculum to me agenda gets + + align:start position:0% +agenda and curriculum to me agenda gets + + + align:start position:0% +agenda and curriculum to me agenda gets +a bad rap just like propaganda but + + align:start position:0% +a bad rap just like propaganda but + + + align:start position:0% +a bad rap just like propaganda but +that's a different kettle of horses okay + + align:start position:0% +that's a different kettle of horses okay + + + align:start position:0% +that's a different kettle of horses okay +so then the third curriculum that Posner + + align:start position:0% +so then the third curriculum that Posner + + + align:start position:0% +so then the third curriculum that Posner +talks about is the hidden curriculum + + align:start position:0% +talks about is the hidden curriculum + + + align:start position:0% +talks about is the hidden curriculum +what is not official what is not + + align:start position:0% +what is not official what is not + + + align:start position:0% +what is not official what is not +officially written down and intended and + + align:start position:0% +officially written down and intended and + + + align:start position:0% +officially written down and intended and +what also is not necessarily + + align:start position:0% +what also is not necessarily + + + align:start position:0% +what also is not necessarily +operationalized intentionally but it is + + align:start position:0% +operationalized intentionally but it is + + + align:start position:0% +operationalized intentionally but it is +what is hidden and gets learned and + + align:start position:0% +what is hidden and gets learned and + + + align:start position:0% +what is hidden and gets learned and +taught at the same time the fourth would + + align:start position:0% +taught at the same time the fourth would + + + align:start position:0% +taught at the same time the fourth would +then be the null curriculum what is not + + align:start position:0% +then be the null curriculum what is not + + + align:start position:0% +then be the null curriculum what is not +taught but is not intended to be + + align:start position:0% +taught but is not intended to be + + + align:start position:0% +taught but is not intended to be +it's absent and explicitly missing and + + align:start position:0% +it's absent and explicitly missing and + + + align:start position:0% +it's absent and explicitly missing and +then the fifth is the extra curriculum + + align:start position:0% +then the fifth is the extra curriculum + + + align:start position:0% +then the fifth is the extra curriculum +that doesn't happen inside those + + align:start position:0% +that doesn't happen inside those + + + align:start position:0% +that doesn't happen inside those +intentional spaces though it might think + + align:start position:0% +intentional spaces though it might think + + + align:start position:0% +intentional spaces though it might think +as formalized schooling so if we think + + align:start position:0% +as formalized schooling so if we think + + + align:start position:0% +as formalized schooling so if we think +of you know you're on the volleyball + + align:start position:0% +of you know you're on the volleyball + + + align:start position:0% +of you know you're on the volleyball +team that's extra curricular but it's + + align:start position:0% +team that's extra curricular but it's + + + align:start position:0% +team that's extra curricular but it's +still related to that education space + + align:start position:0% +still related to that education space + + + align:start position:0% +still related to that education space +all five of those things are happening + + align:start position:0% +all five of those things are happening + + + align:start position:0% +all five of those things are happening +all the time so the hidden agenda + + align:start position:0% +all the time so the hidden agenda + + + align:start position:0% +all the time so the hidden agenda +they're hidden curriculum is one that I + + align:start position:0% +they're hidden curriculum is one that I + + + align:start position:0% +they're hidden curriculum is one that I +and there's some tension there right + + align:start position:0% +and there's some tension there right + + + align:start position:0% +and there's some tension there right +because in some cases it's + + align:start position:0% +because in some cases it's + + + align:start position:0% +because in some cases it's +operationalized with a conscious + + align:start position:0% +operationalized with a conscious + + + align:start position:0% +operationalized with a conscious +awareness that it's hidden I'm not going + + align:start position:0% +awareness that it's hidden I'm not going + + + align:start position:0% +awareness that it's hidden I'm not going +to be explicit about it but then there + + align:start position:0% +to be explicit about it but then there + + + align:start position:0% +to be explicit about it but then there +can be a hidden curriculum where it's + + align:start position:0% +can be a hidden curriculum where it's + + + align:start position:0% +can be a hidden curriculum where it's +being taught and learned without the + + align:start position:0% +being taught and learned without the + + + align:start position:0% +being taught and learned without the +intention of it being taught and learned + + align:start position:0% +intention of it being taught and learned + + + align:start position:0% +intention of it being taught and learned +cutes - for example there are bathrooms + + align:start position:0% + + + + align:start position:0% + +bathrooms boys and girls and so it's + + align:start position:0% +bathrooms boys and girls and so it's + + + align:start position:0% +bathrooms boys and girls and so it's +teaching us certain things about how + + align:start position:0% +teaching us certain things about how + + + align:start position:0% +teaching us certain things about how +society is structured but when we move + + align:start position:0% +society is structured but when we move + + + align:start position:0% +society is structured but when we move +and have a shift in our cultural and + + align:start position:0% +and have a shift in our cultural and + + + align:start position:0% +and have a shift in our cultural and +social space where bathrooms don't have + + align:start position:0% +social space where bathrooms don't have + + + align:start position:0% +social space where bathrooms don't have +to have certain labels then other + + align:start position:0% +to have certain labels then other + + + align:start position:0% +to have certain labels then other +knowledge other ideas are taught and + + align:start position:0% +knowledge other ideas are taught and + + + align:start position:0% +knowledge other ideas are taught and +learned through those gestures but + + align:start position:0% +learned through those gestures but + + + align:start position:0% +learned through those gestures but +they're not necessarily official does + + align:start position:0% +they're not necessarily official does + + + align:start position:0% +they're not necessarily official does +that make sense yeah okay so the program + + align:start position:0% +that make sense yeah okay so the program + + + align:start position:0% +that make sense yeah okay so the program +where I teach at Penn State for in our + + align:start position:0% +where I teach at Penn State for in our + + + align:start position:0% +where I teach at Penn State for in our +education also at V CFA we're very + + align:start position:0% +education also at V CFA we're very + + + align:start position:0% +education also at V CFA we're very +explicit about what that hidden agenda + + align:start position:0% +explicit about what that hidden agenda + + + align:start position:0% +explicit about what that hidden agenda +might be as to the point where it's not + + align:start position:0% +might be as to the point where it's not + + + align:start position:0% +might be as to the point where it's not +hidden at all it's very up front it's + + align:start position:0% +hidden at all it's very up front it's + + + align:start position:0% +hidden at all it's very up front it's +very official and it gets operationalize + + align:start position:0% +very official and it gets operationalize + + + align:start position:0% +very official and it gets operationalize +in terms of focus on social justice a + + align:start position:0% +in terms of focus on social justice a + + + align:start position:0% +in terms of focus on social justice a +focus on the the role of artists and art + + align:start position:0% +focus on the the role of artists and art + + + align:start position:0% +focus on the the role of artists and art +in the world + + align:start position:0% +in the world + + + align:start position:0% +in the world +and-and-and what matters matter and how + + align:start position:0% +and-and-and what matters matter and how + + + align:start position:0% +and-and-and what matters matter and how +we can engage with concepts like such as + + align:start position:0% +we can engage with concepts like such as + + + align:start position:0% +we can engage with concepts like such as +in theories like we heard in the + + align:start position:0% +in theories like we heard in the + + + align:start position:0% +in theories like we heard in the +introduction feminist theory or a + + align:start position:0% +introduction feminist theory or a + + + align:start position:0% +introduction feminist theory or a +critical race theory or a critical + + align:start position:0% +critical race theory or a critical + + + align:start position:0% +critical race theory or a critical +pedagogy or we can think about + + align:start position:0% +pedagogy or we can think about + + + align:start position:0% +pedagogy or we can think about +anti-racist theory right so we can think + + align:start position:0% +anti-racist theory right so we can think + + + align:start position:0% +anti-racist theory right so we can think +about what disability studies all of + + align:start position:0% +about what disability studies all of + + + align:start position:0% +about what disability studies all of +these different ways in which society + + align:start position:0% +these different ways in which society + + + align:start position:0% +these different ways in which society +operates are part of the curriculum that + + align:start position:0% +operates are part of the curriculum that + + + align:start position:0% +operates are part of the curriculum that +I've been part of in these two + + align:start position:0% +I've been part of in these two + + + align:start position:0% +I've been part of in these two +institutions to look at the preparation + + align:start position:0% +institutions to look at the preparation + + + align:start position:0% +institutions to look at the preparation +of teachers so someone who says hey I + + align:start position:0% +of teachers so someone who says hey I + + + align:start position:0% +of teachers so someone who says hey I +want to go you know study in this + + align:start position:0% +want to go you know study in this + + + align:start position:0% +want to go you know study in this +program it's not a surprise to them when + + align:start position:0% +program it's not a surprise to them when + + + align:start position:0% +program it's not a surprise to them when +we start + + align:start position:0% +we start + + + align:start position:0% +we start +talking about feminist pedagogy and + + align:start position:0% +talking about feminist pedagogy and + + + align:start position:0% +talking about feminist pedagogy and +feminist issues what might be a surprise + + align:start position:0% +feminist issues what might be a surprise + + + align:start position:0% +feminist issues what might be a surprise +is perhaps the ways in which we approach + + align:start position:0% +is perhaps the ways in which we approach + + + align:start position:0% +is perhaps the ways in which we approach +that and then operationalize it but it's + + align:start position:0% +that and then operationalize it but it's + + + align:start position:0% +that and then operationalize it but it's +not it shouldn't be a surprise now in + + align:start position:0% +not it shouldn't be a surprise now in + + + align:start position:0% +not it shouldn't be a surprise now in +some cases some people might not always + + align:start position:0% +some cases some people might not always + + + align:start position:0% +some cases some people might not always +read the the fine print but and then + + align:start position:0% +read the the fine print but and then + + + align:start position:0% +read the the fine print but and then +there might be a surprise there but I'm + + align:start position:0% +there might be a surprise there but I'm + + + align:start position:0% +there might be a surprise there but I'm +not I don't I don't hide those issues as + + align:start position:0% +not I don't I don't hide those issues as + + + align:start position:0% +not I don't I don't hide those issues as +a matter of fact I'm very upfront with + + align:start position:0% +a matter of fact I'm very upfront with + + + align:start position:0% +a matter of fact I'm very upfront with +with my undergraduates about you know in + + align:start position:0% +with my undergraduates about you know in + + + align:start position:0% +with my undergraduates about you know in +this course we're going to we're going + + align:start position:0% +this course we're going to we're going + + + align:start position:0% +this course we're going to we're going +to learn about learning and I'm more + + align:start position:0% +to learn about learning and I'm more + + + align:start position:0% +to learn about learning and I'm more +interested in learning than I am in + + align:start position:0% +interested in learning than I am in + + + align:start position:0% +interested in learning than I am in +teaching and that doesn't make sense to + + align:start position:0% +teaching and that doesn't make sense to + + + align:start position:0% +teaching and that doesn't make sense to +a lot of people who are preparing to be + + align:start position:0% +a lot of people who are preparing to be + + + align:start position:0% +a lot of people who are preparing to be +teachers or thinking about teaching + + align:start position:0% +teachers or thinking about teaching + + + align:start position:0% +teachers or thinking about teaching +because to frame it around learning + + align:start position:0% +because to frame it around learning + + + align:start position:0% +because to frame it around learning +suggests there's a shift from the agency + + align:start position:0% +suggests there's a shift from the agency + + + align:start position:0% +suggests there's a shift from the agency +of the teacher as the primary vehicle to + + align:start position:0% +of the teacher as the primary vehicle to + + + align:start position:0% +of the teacher as the primary vehicle to +the to the student do I need a first + + align:start position:0% +the to the student do I need a first + + + align:start position:0% +the to the student do I need a first +course where there's no interference + + align:start position:0% +course where there's no interference + + + align:start position:0% +course where there's no interference +with learning to draw Basics in a basic + + align:start position:0% +with learning to draw Basics in a basic + + + align:start position:0% +with learning to draw Basics in a basic +way and then after that I can come to a + + align:start position:0% +way and then after that I can come to a + + + align:start position:0% +way and then after that I can come to a +second level drawing class where you can + + align:start position:0% +second level drawing class where you can + + + align:start position:0% +second level drawing class where you can +lay on all this other stuff or from the + + align:start position:0% +lay on all this other stuff or from the + + + align:start position:0% +lay on all this other stuff or from the +very beginning in even the most + + align:start position:0% +very beginning in even the most + + + align:start position:0% +very beginning in even the most +rudimentary learning of the medium are + + align:start position:0% +rudimentary learning of the medium are + + + align:start position:0% +rudimentary learning of the medium are +you already insinuating into the design + + align:start position:0% +you already insinuating into the design + + + align:start position:0% +you already insinuating into the design +of this curriculum this other set of + + align:start position:0% +of this curriculum this other set of + + + align:start position:0% +of this curriculum this other set of +concerns I don't even I don't have to + + align:start position:0% +concerns I don't even I don't have to + + + align:start position:0% +concerns I don't even I don't have to +know anything about the basics + + align:start position:0% +know anything about the basics + + + align:start position:0% +know anything about the basics +independent of this second concern to + + align:start position:0% +independent of this second concern to + + + align:start position:0% +independent of this second concern to +start learning this other set of things + + align:start position:0% +start learning this other set of things + + + align:start position:0% +start learning this other set of things +no one can enter with the concerns and + + align:start position:0% +no one can enter with the concerns and + + + align:start position:0% +no one can enter with the concerns and +that is your plan most of the time all + + align:start position:0% +that is your plan most of the time all + + + align:start position:0% +that is your plan most of the time all +of that all the time oh that's so we + + align:start position:0% +of that all the time oh that's so we + + + align:start position:0% +of that all the time oh that's so we +start with we start with that's a social + + align:start position:0% +start with we start with that's a social + + + align:start position:0% +start with we start with that's a social +social issue or let's say we're + + align:start position:0% +social issue or let's say we're + + + align:start position:0% +social issue or let's say we're +grounding the the course within a social + + align:start position:0% +grounding the the course within a social + + + align:start position:0% +grounding the the course within a social +space right we all live in a social + + align:start position:0% +space right we all live in a social + + + align:start position:0% +space right we all live in a social +space we all come with the set of + + align:start position:0% +space we all come with the set of + + + align:start position:0% +space we all come with the set of +concerns we all come with a set of + + align:start position:0% +concerns we all come with a set of + + + align:start position:0% +concerns we all come with a set of +experiences we come to the studio and + + align:start position:0% +experiences we come to the studio and + + + align:start position:0% +experiences we come to the studio and +then return to wherever we were before + + align:start position:0% +then return to wherever we were before + + + align:start position:0% +then return to wherever we were before +that what what what we experience + + align:start position:0% +that what what what we experience + + + align:start position:0% +that what what what we experience +outside of the studio is content for art + + align:start position:0% +outside of the studio is content for art + + + align:start position:0% +outside of the studio is content for art +making its content for + + align:start position:0% +making its content for + + + align:start position:0% +making its content for +engagement through art so you know this + + align:start position:0% +engagement through art so you know this + + + align:start position:0% +engagement through art so you know this +this is a this is a shift where we think + + align:start position:0% +this is a this is a shift where we think + + + align:start position:0% +this is a this is a shift where we think +of you know so if we take a step back to + + align:start position:0% +of you know so if we take a step back to + + + align:start position:0% +of you know so if we take a step back to +notions of curriculum a very basic a + + align:start position:0% +notions of curriculum a very basic a + + + align:start position:0% +notions of curriculum a very basic a +very basic question in curriculum design + + align:start position:0% +very basic question in curriculum design + + + align:start position:0% +very basic question in curriculum design +curriculum theory curriculum development + + align:start position:0% +curriculum theory curriculum development + + + align:start position:0% +curriculum theory curriculum development +I should say is what is worth knowing + + align:start position:0% +I should say is what is worth knowing + + + align:start position:0% +I should say is what is worth knowing +what content do we want students to + + align:start position:0% +what content do we want students to + + + align:start position:0% +what content do we want students to +learn what is worth knowing you know we + + align:start position:0% +learn what is worth knowing you know we + + + align:start position:0% +learn what is worth knowing you know we +might then look through the progression + + align:start position:0% +might then look through the progression + + + align:start position:0% +might then look through the progression +of curricula and then folks 30 40 years + + align:start position:0% +of curricula and then folks 30 40 years + + + align:start position:0% +of curricula and then folks 30 40 years +ago ship make start making a shift our + + align:start position:0% +ago ship make start making a shift our + + + align:start position:0% +ago ship make start making a shift our +thing what is worthwhile what matters + + align:start position:0% +thing what is worthwhile what matters + + + align:start position:0% +thing what is worthwhile what matters +and what is happens is there's a + + align:start position:0% +and what is happens is there's a + + + align:start position:0% +and what is happens is there's a +movement away from a more modernist + + align:start position:0% +movement away from a more modernist + + + align:start position:0% +movement away from a more modernist +notion of art as material based to art + + align:start position:0% +notion of art as material based to art + + + align:start position:0% +notion of art as material based to art +as a reflection and engagement within + + align:start position:0% +as a reflection and engagement within + + + align:start position:0% +as a reflection and engagement within +the world + + align:start position:0% +the world + + + align:start position:0% +the world +not that it hadn't been that way before + + align:start position:0% +not that it hadn't been that way before + + + align:start position:0% +not that it hadn't been that way before +but that the the world becomes art + + align:start position:0% +but that the the world becomes art + + + align:start position:0% +but that the the world becomes art +making medium and in a context that can + + align:start position:0% +making medium and in a context that can + + + align:start position:0% +making medium and in a context that can +be not only reflected and depicted but + + align:start position:0% +be not only reflected and depicted but + + + align:start position:0% +be not only reflected and depicted but +can also be used as one of the materials + + align:start position:0% +can also be used as one of the materials + + + align:start position:0% +can also be used as one of the materials +within art making practice and that art + + align:start position:0% +within art making practice and that art + + + align:start position:0% +within art making practice and that art +practice can have some sort of engaged + + align:start position:0% +practice can have some sort of engaged + + + align:start position:0% +practice can have some sort of engaged +in an intentional effect within there so + + align:start position:0% +in an intentional effect within there so + + + align:start position:0% +in an intentional effect within there so +what so the kind of drawing class that + + align:start position:0% +what so the kind of drawing class that + + + align:start position:0% +what so the kind of drawing class that +you're mentioning or describing it's not + + align:start position:0% +you're mentioning or describing it's not + + + align:start position:0% +you're mentioning or describing it's not +uncommon these kinds of courses happen + + align:start position:0% +uncommon these kinds of courses happen + + + align:start position:0% +uncommon these kinds of courses happen +quite often but their titles don't + + align:start position:0% +quite often but their titles don't + + + align:start position:0% +quite often but their titles don't +always reflect that and in the lot and + + align:start position:0% +always reflect that and in the lot and + + + align:start position:0% +always reflect that and in the lot and +many art schools are ship making some + + align:start position:0% +many art schools are ship making some + + + align:start position:0% +many art schools are ship making some +shifts I've mentioned to a colleague a + + align:start position:0% +shifts I've mentioned to a colleague a + + + align:start position:0% +shifts I've mentioned to a colleague a +number of years ago I said you know we + + align:start position:0% +number of years ago I said you know we + + + align:start position:0% +number of years ago I said you know we +really need to change the names of some + + align:start position:0% +really need to change the names of some + + + align:start position:0% +really need to change the names of some +of these courses like we should have you + + align:start position:0% +of these courses like we should have you + + + align:start position:0% +of these courses like we should have you +know art with Larry know you know art + + align:start position:0% +know art with Larry know you know art + + + align:start position:0% +know art with Larry know you know art +505 art with Larry and then art 507 art + + align:start position:0% +505 art with Larry and then art 507 art + + + align:start position:0% +505 art with Larry and then art 507 art +with Steve and they would have a sense + + align:start position:0% +with Steve and they would have a sense + + + align:start position:0% +with Steve and they would have a sense +of what that course was about it's not a + + align:start position:0% +of what that course was about it's not a + + + align:start position:0% +of what that course was about it's not a +materials specific course although it + + align:start position:0% +materials specific course although it + + + align:start position:0% +materials specific course although it +could be but when we move the focus to + + align:start position:0% +could be but when we move the focus to + + + align:start position:0% +could be but when we move the focus to +issues ideas concerns engagements + + align:start position:0% +issues ideas concerns engagements + + + align:start position:0% +issues ideas concerns engagements +problems ideas that that is an easier + + align:start position:0% +problems ideas that that is an easier + + + align:start position:0% +problems ideas that that is an easier +entry point for the kinds of pedagogy + + align:start position:0% +entry point for the kinds of pedagogy + + + align:start position:0% +entry point for the kinds of pedagogy +that we're talking about that that that + + align:start position:0% +that we're talking about that that that + + + align:start position:0% +that we're talking about that that that +lend themselves to the sensibilities of + + align:start position:0% +lend themselves to the sensibilities of + + + align:start position:0% +lend themselves to the sensibilities of +disruptive + + align:start position:0% +disruptive + + + align:start position:0% +disruptive +corrupted practices of social + + align:start position:0% +corrupted practices of social + + + align:start position:0% +corrupted practices of social +consciousness of transformative learning + + align:start position:0% +consciousness of transformative learning + + + align:start position:0% +consciousness of transformative learning +and what I've taken from your comments + + align:start position:0% +and what I've taken from your comments + + + align:start position:0% +and what I've taken from your comments +on occasion is that I ought to have that + + align:start position:0% +on occasion is that I ought to have that + + + align:start position:0% +on occasion is that I ought to have that +objective if I'm if I'm gonna teach + + align:start position:0% +objective if I'm if I'm gonna teach + + + align:start position:0% +objective if I'm if I'm gonna teach +people about operating their community + + align:start position:0% +people about operating their community + + + align:start position:0% +people about operating their community +don't just teach the method or the + + align:start position:0% +don't just teach the method or the + + + align:start position:0% +don't just teach the method or the +content but get to this other level and + + align:start position:0% +content but get to this other level and + + + align:start position:0% +content but get to this other level and +build that into the curriculum take + + align:start position:0% +build that into the curriculum take + + + align:start position:0% +build that into the curriculum take +responsibility for that be explicit + + align:start position:0% +responsibility for that be explicit + + + align:start position:0% +responsibility for that be explicit +about it be accountable not just during + + align:start position:0% +about it be accountable not just during + + + align:start position:0% +about it be accountable not just during +but you've before although who knows + + align:start position:0% +but you've before although who knows + + + align:start position:0% +but you've before although who knows +whether they would have let me anywhere + + align:start position:0% +whether they would have let me anywhere + + + align:start position:0% +whether they would have let me anywhere +near the place if I had said at the + + align:start position:0% +near the place if I had said at the + + + align:start position:0% +near the place if I had said at the +beginning our goal here is to bring + + align:start position:0% +beginning our goal here is to bring + + + align:start position:0% +beginning our goal here is to bring +about change in this community well it + + align:start position:0% +about change in this community well it + + + align:start position:0% +about change in this community well it +depends on your strategy there right so + + align:start position:0% +depends on your strategy there right so + + + align:start position:0% +depends on your strategy there right so +if you think about it this way not and + + align:start position:0% +if you think about it this way not and + + + align:start position:0% +if you think about it this way not and +not in you didn't mention this in your + + align:start position:0% +not in you didn't mention this in your + + + align:start position:0% +not in you didn't mention this in your +your story but I'm I would be interested + + align:start position:0% +your story but I'm I would be interested + + + align:start position:0% +your story but I'm I would be interested +in this component because it also then + + align:start position:0% +in this component because it also then + + + align:start position:0% +in this component because it also then +gets back to part of one of those parts + + align:start position:0% +gets back to part of one of those parts + + + align:start position:0% +gets back to part of one of those parts +of the longer question you asked me + + align:start position:0% +of the longer question you asked me + + + align:start position:0% +of the longer question you asked me +earlier about my own students my own + + align:start position:0% +earlier about my own students my own + + + align:start position:0% +earlier about my own students my own +teaching this is part of the social + + align:start position:0% +teaching this is part of the social + + + align:start position:0% +teaching this is part of the social +studies curriculum officially right + + align:start position:0% +studies curriculum officially right + + + align:start position:0% +studies curriculum officially right +there should be some objectives there + + align:start position:0% +there should be some objectives there + + + align:start position:0% +there should be some objectives there +should be some state standards or + + align:start position:0% +should be some state standards or + + + align:start position:0% +should be some state standards or +district standards or district + + align:start position:0% +district standards or district + + + align:start position:0% +district standards or district +objectives that many teachers consider + + align:start position:0% +objectives that many teachers consider + + + align:start position:0% +objectives that many teachers consider +to be the curriculum and they teach to + + align:start position:0% +to be the curriculum and they teach to + + + align:start position:0% +to be the curriculum and they teach to +those standards or to those objectives I + + align:start position:0% +those standards or to those objectives I + + + align:start position:0% +those standards or to those objectives I +teach my students put those aside let's + + align:start position:0% +teach my students put those aside let's + + + align:start position:0% +teach my students put those aside let's +build on what you know what is most + + align:start position:0% +build on what you know what is most + + + align:start position:0% +build on what you know what is most +important what you know but on your own + + align:start position:0% +important what you know but on your own + + + align:start position:0% +important what you know but on your own +politics build on the let's start with + + align:start position:0% +politics build on the let's start with + + + align:start position:0% +politics build on the let's start with +the themes and the ideas and the + + align:start position:0% +the themes and the ideas and the + + + align:start position:0% +the themes and the ideas and the +concerns that you have build your + + align:start position:0% +concerns that you have build your + + + align:start position:0% +concerns that you have build your +curriculum around that drawing on your + + align:start position:0% +curriculum around that drawing on your + + + align:start position:0% +curriculum around that drawing on your +art practice your knowledge of art and + + align:start position:0% +art practice your knowledge of art and + + + align:start position:0% +art practice your knowledge of art and +then let's compare let's use those + + align:start position:0% +then let's compare let's use those + + + align:start position:0% +then let's compare let's use those +standards or those objectives as an + + align:start position:0% +standards or those objectives as an + + + align:start position:0% +standards or those objectives as an +assessment now how many of those did we + + align:start position:0% +assessment now how many of those did we + + + align:start position:0% +assessment now how many of those did we +address usually we can cover all of + + align:start position:0% +address usually we can cover all of + + + align:start position:0% +address usually we can cover all of +those but if we start the other way + + align:start position:0% +those but if we start the other way + + + align:start position:0% +those but if we start the other way +around we start with you know learning + + align:start position:0% +around we start with you know learning + + + align:start position:0% +around we start with you know learning +objective six and learning objective + + align:start position:0% +objective six and learning objective + + + align:start position:0% +objective six and learning objective +eight and this is the lesson it's gonna + + align:start position:0% +eight and this is the lesson it's gonna + + + align:start position:0% +eight and this is the lesson it's gonna +be really narrow and tight and it does + + align:start position:0% +be really narrow and tight and it does + + + align:start position:0% +be really narrow and tight and it does +and you're always going to be interested + + align:start position:0% +and you're always going to be interested + + + align:start position:0% +and you're always going to be interested +in we got to kick it back into the + + align:start position:0% +in we got to kick it back into the + + + align:start position:0% +in we got to kick it back into the +center we got to make sure there but in + + align:start position:0% +center we got to make sure there but in + + + align:start position:0% +center we got to make sure there but in +the way that you did it I would imagine + + align:start position:0% +the way that you did it I would imagine + + + align:start position:0% +the way that you did it I would imagine +you could have said at any given moment + + align:start position:0% +you could have said at any given moment + + + align:start position:0% +you could have said at any given moment +when you felt some resistance well if we + + align:start position:0% +when you felt some resistance well if we + + + align:start position:0% +when you felt some resistance well if we +look at this + + align:start position:0% +look at this + + + align:start position:0% +look at this +we're covering XYZ one two three four + + align:start position:0% +we're covering XYZ one two three four + + + align:start position:0% +we're covering XYZ one two three four +five six seven because and this is a way + + align:start position:0% +five six seven because and this is a way + + + align:start position:0% +five six seven because and this is a way +that one not trying to say this is how + + align:start position:0% +that one not trying to say this is how + + + align:start position:0% +that one not trying to say this is how +you do a cover-up story but this is how + + align:start position:0% +you do a cover-up story but this is how + + + align:start position:0% +you do a cover-up story but this is how +you can justify this a this the social + + align:start position:0% +you can justify this a this the social + + + align:start position:0% +you can justify this a this the social +practice social engagement social + + align:start position:0% +practice social engagement social + + + align:start position:0% +practice social engagement social +consciousness pedagogy is you say look + + align:start position:0% +consciousness pedagogy is you say look + + + align:start position:0% +consciousness pedagogy is you say look +we're meeting all of the standards as a + + align:start position:0% +we're meeting all of the standards as a + + + align:start position:0% +we're meeting all of the standards as a +matter of fact if we were to do let's + + align:start position:0% +matter of fact if we were to do let's + + + align:start position:0% +matter of fact if we were to do let's +say three units like this over the + + align:start position:0% +say three units like this over the + + + align:start position:0% +say three units like this over the +course of the year we could hit all of + + align:start position:0% +course of the year we could hit all of + + + align:start position:0% +course of the year we could hit all of +those objectives each time if we do it + + align:start position:0% +those objectives each time if we do it + + + align:start position:0% +those objectives each time if we do it +in a more conventional approach we might + + align:start position:0% +in a more conventional approach we might + + + align:start position:0% +in a more conventional approach we might +only address one of those objectives + + align:start position:0% +only address one of those objectives + + + align:start position:0% +only address one of those objectives +once or a few of them very superficially + + align:start position:0% +once or a few of them very superficially + + + align:start position:0% +once or a few of them very superficially +so this becomes an even more potent way + + align:start position:0% +so this becomes an even more potent way + + + align:start position:0% +so this becomes an even more potent way +to make to make a case because you're + + align:start position:0% +to make to make a case because you're + + + align:start position:0% +to make to make a case because you're +using the you're talking about values + + align:start position:0% +using the you're talking about values + + + align:start position:0% +using the you're talking about values +the objectives against them yes I call + + align:start position:0% +the objectives against them yes I call + + + align:start position:0% +the objectives against them yes I call +it playing judo you use your opponent's + + align:start position:0% +it playing judo you use your opponent's + + + align:start position:0% +it playing judo you use your opponent's +strength and speed to your advantage + + align:start position:0% +strength and speed to your advantage + + + align:start position:0% +strength and speed to your advantage +right yeah you know when I teach + + align:start position:0% +right yeah you know when I teach + + + align:start position:0% +right yeah you know when I teach +graduate students who are in a + + align:start position:0% +graduate students who are in a + + + align:start position:0% +graduate students who are in a +professional degree program all of this + + align:start position:0% +professional degree program all of this + + + align:start position:0% +professional degree program all of this +has easily talked about its layered into + + align:start position:0% +has easily talked about its layered into + + + align:start position:0% +has easily talked about its layered into +the the social objectives the social + + align:start position:0% +the the social objectives the social + + + align:start position:0% +the the social objectives the social +change in fact the that it's all easily + + align:start position:0% +change in fact the that it's all easily + + + align:start position:0% +change in fact the that it's all easily +included in the conversation and there's + + align:start position:0% +included in the conversation and there's + + + align:start position:0% +included in the conversation and there's +an explicit reflection on the social + + align:start position:0% +an explicit reflection on the social + + + align:start position:0% +an explicit reflection on the social +impact social implication social change + + align:start position:0% +impact social implication social change + + + align:start position:0% +impact social implication social change +or who gets who wins who loses if you do + + align:start position:0% +or who gets who wins who loses if you do + + + align:start position:0% +or who gets who wins who loses if you do +this and so on it's just it's + + align:start position:0% +this and so on it's just it's + + + align:start position:0% +this and so on it's just it's +fascinating to me that you're teaching + + align:start position:0% +fascinating to me that you're teaching + + + align:start position:0% +fascinating to me that you're teaching +teachers are teaching kids in elementary + + align:start position:0% +teachers are teaching kids in elementary + + + align:start position:0% +teachers are teaching kids in elementary +school and you're in a sense teaching + + align:start position:0% +school and you're in a sense teaching + + + align:start position:0% +school and you're in a sense teaching +the same thing and you're not really + + align:start position:0% +the same thing and you're not really + + + align:start position:0% +the same thing and you're not really +modulating that much you're still saying + + align:start position:0% +modulating that much you're still saying + + + align:start position:0% +modulating that much you're still saying +as biases here you do everyone has a + + align:start position:0% +as biases here you do everyone has a + + + align:start position:0% +as biases here you do everyone has a +bias learn what you're including what + + align:start position:0% +bias learn what you're including what + + + align:start position:0% +bias learn what you're including what +you're not including and it sounds like + + align:start position:0% +you're not including and it sounds like + + + align:start position:0% +you're not including and it sounds like +you would say that to every level and + + align:start position:0% +you would say that to every level and + + + align:start position:0% +you would say that to every level and +did the teachers teaching in every level + + align:start position:0% +did the teachers teaching in every level + + + align:start position:0% +did the teachers teaching in every level +and that was it was surprising to me + + align:start position:0% +and that was it was surprising to me + + + align:start position:0% +and that was it was surprising to me +that all of this was as explicit in your + + align:start position:0% +that all of this was as explicit in your + + + align:start position:0% +that all of this was as explicit in your +curriculum in your teaching for K + + align:start position:0% +curriculum in your teaching for K + + + align:start position:0% +curriculum in your teaching for K +through 12 as it is in teaching + + align:start position:0% +through 12 as it is in teaching + + + align:start position:0% +through 12 as it is in teaching +professionals a couple examples to them + + align:start position:0% +professionals a couple examples to them + + + align:start position:0% +professionals a couple examples to them +to say yes to support what you're saying + + align:start position:0% +to say yes to support what you're saying + + + align:start position:0% +to say yes to support what you're saying +so + + align:start position:0% +so + + + align:start position:0% +so +you know their number of course is that + + align:start position:0% +you know their number of course is that + + + align:start position:0% +you know their number of course is that +that one might find in an undergraduate + + align:start position:0% +that one might find in an undergraduate + + + align:start position:0% +that one might find in an undergraduate +or pre-service or an education + + align:start position:0% +or pre-service or an education + + + align:start position:0% +or pre-service or an education +curriculum right you can imagine there's + + align:start position:0% +curriculum right you can imagine there's + + + align:start position:0% +curriculum right you can imagine there's +this has to be a 101 or what we know + + align:start position:0% +this has to be a 101 or what we know + + + align:start position:0% +this has to be a 101 or what we know +aren't education 101 right intro and + + align:start position:0% +aren't education 101 right intro and + + + align:start position:0% +aren't education 101 right intro and +then there has to be the student + + align:start position:0% +then there has to be the student + + + align:start position:0% +then there has to be the student +teaching at the other end and and + + align:start position:0% +teaching at the other end and and + + + align:start position:0% +teaching at the other end and and +somewhere in there there's a practical + + align:start position:0% +somewhere in there there's a practical + + + align:start position:0% +somewhere in there there's a practical +course many places have methods courses + + align:start position:0% +course many places have methods courses + + + align:start position:0% +course many places have methods courses +there's a usually a history course or a + + align:start position:0% +there's a usually a history course or a + + + align:start position:0% +there's a usually a history course or a +cultural practices or cultural + + align:start position:0% +cultural practices or cultural + + + align:start position:0% +cultural practices or cultural +foundations course and there's also a + + align:start position:0% +foundations course and there's also a + + + align:start position:0% +foundations course and there's also a +curriculum course and it depends on what + + align:start position:0% +curriculum course and it depends on what + + + align:start position:0% +curriculum course and it depends on what +institution where I'm teaching but + + align:start position:0% +institution where I'm teaching but + + + align:start position:0% +institution where I'm teaching but +usually if it's the curriculum course or + + align:start position:0% +usually if it's the curriculum course or + + + align:start position:0% +usually if it's the curriculum course or +the the cultural and social foundations + + align:start position:0% +the the cultural and social foundations + + + align:start position:0% +the the cultural and social foundations +course the first day of class this is + + align:start position:0% +course the first day of class this is + + + align:start position:0% +course the first day of class this is +how I start the class now you we've + + align:start position:0% +how I start the class now you we've + + + align:start position:0% +how I start the class now you we've +known each other for almost two years + + align:start position:0% +known each other for almost two years + + + align:start position:0% +known each other for almost two years +now and and we've sat through these + + align:start position:0% +now and and we've sat through these + + + align:start position:0% +now and and we've sat through these +conversations so you know what I look + + align:start position:0% +conversations so you know what I look + + + align:start position:0% +conversations so you know what I look +like you know what I sound like + + align:start position:0% +like you know what I sound like + + + align:start position:0% +like you know what I sound like +but imagine students who are just + + align:start position:0% +but imagine students who are just + + + align:start position:0% +but imagine students who are just +showing up to class for the first time + + align:start position:0% +showing up to class for the first time + + + align:start position:0% +showing up to class for the first time +right and this is how I start the class + + align:start position:0% +right and this is how I start the class + + + align:start position:0% +right and this is how I start the class +good afternoon my name is dr. carpenter + + align:start position:0% +good afternoon my name is dr. carpenter + + + align:start position:0% +good afternoon my name is dr. carpenter +and I'll be your instructor this + + align:start position:0% +and I'll be your instructor this + + + align:start position:0% +and I'll be your instructor this +semester so for the next 16 weeks we'll + + align:start position:0% +semester so for the next 16 weeks we'll + + + align:start position:0% +semester so for the next 16 weeks we'll +be engaging in curriculum and cultural + + align:start position:0% +be engaging in curriculum and cultural + + + align:start position:0% +be engaging in curriculum and cultural +and social issues related to arts + + align:start position:0% +and social issues related to arts + + + align:start position:0% +and social issues related to arts +education now some of you come to the + + align:start position:0% +education now some of you come to the + + + align:start position:0% +education now some of you come to the +course as artists and others come as and + + align:start position:0% +course as artists and others come as and + + + align:start position:0% +course as artists and others come as and +I continue in just this way and we start + + align:start position:0% +I continue in just this way and we start + + + align:start position:0% +I continue in just this way and we start +to read the syllabus and at a certain + + align:start position:0% +to read the syllabus and at a certain + + + align:start position:0% +to read the syllabus and at a certain +point I just can't do this or I cannot + + align:start position:0% +point I just can't do this or I cannot + + + align:start position:0% +point I just can't do this or I cannot +find different regions of the UK to move + + align:start position:0% +find different regions of the UK to move + + + align:start position:0% +find different regions of the UK to move +around my accent you know and certain + + align:start position:0% +around my accent you know and certain + + + align:start position:0% +around my accent you know and certain +students start to see and look and then + + align:start position:0% +students start to see and look and then + + + align:start position:0% +students start to see and look and then +I say well now the next thing that we're + + align:start position:0% +I say well now the next thing that we're + + + align:start position:0% +I say well now the next thing that we're +going to do and I changed my voice like + + align:start position:0% +going to do and I changed my voice like + + + align:start position:0% +going to do and I changed my voice like +this and I stopped them right there does + + align:start position:0% +this and I stopped them right there does + + + align:start position:0% +this and I stopped them right there does +the first day class Larry you're you + + align:start position:0% +the first day class Larry you're you + + + align:start position:0% +the first day class Larry you're you +haven't blinked in a minute and your + + align:start position:0% +haven't blinked in a minute and your + + + align:start position:0% +haven't blinked in a minute and your +mouth is wide open and you're giggling + + align:start position:0% +mouth is wide open and you're giggling + + + align:start position:0% +mouth is wide open and you're giggling +and what's going on here and and I make + + align:start position:0% +and what's going on here and and I make + + + align:start position:0% +and what's going on here and and I make +them toxic well what's up well you sound + + align:start position:0% +them toxic well what's up well you sound + + + align:start position:0% +them toxic well what's up well you sound +different I sound different than what + + align:start position:0% +different I sound different than what + + + align:start position:0% +different I sound different than what +well you sound different than you did + + align:start position:0% +well you sound different than you did + + + align:start position:0% +well you sound different than you did +before what did I sound like before well + + align:start position:0% +before what did I sound like before well + + + align:start position:0% +before what did I sound like before well +you sounded had an accent oh I did what + + align:start position:0% +you sounded had an accent oh I did what + + + align:start position:0% +you sounded had an accent oh I did what +kind of accent well they said well you + + align:start position:0% +kind of accent well they said well you + + + align:start position:0% +kind of accent well they said well you +know if I'm someplace else I have an + + align:start position:0% +know if I'm someplace else I have an + + + align:start position:0% +know if I'm someplace else I have an +accent there but when I'm home I don't + + align:start position:0% +accent there but when I'm home I don't + + + align:start position:0% +accent there but when I'm home I don't +have an accent people who sounded like + + align:start position:0% +have an accent people who sounded like + + + align:start position:0% +have an accent people who sounded like +that at home don't have an accent it's + + align:start position:0% +that at home don't have an accent it's + + + align:start position:0% +that at home don't have an accent it's +only when they leave and so what else is + + align:start position:0% +only when they leave and so what else is + + + align:start position:0% +only when they leave and so what else is +different and they and they + + align:start position:0% +different and they and they + + + align:start position:0% +different and they and they +also in talking about well we moved them + + align:start position:0% +also in talking about well we moved them + + + align:start position:0% +also in talking about well we moved them +to the space to say faces that look like + + align:start position:0% +to the space to say faces that look like + + + align:start position:0% +to the space to say faces that look like +mine in most people's conception at + + align:start position:0% +mine in most people's conception at + + + align:start position:0% +mine in most people's conception at +least in institutions where I teach + + align:start position:0% +least in institutions where I teach + + + align:start position:0% +least in institutions where I teach +don't sound like that or the conception + + align:start position:0% +don't sound like that or the conception + + + align:start position:0% +don't sound like that or the conception +of someone with an accent like that + + align:start position:0% +of someone with an accent like that + + + align:start position:0% +of someone with an accent like that +looks different than I do so but I put + + align:start position:0% +looks different than I do so but I put + + + align:start position:0% +looks different than I do so but I put +it on the table and I draw attention to + + align:start position:0% +it on the table and I draw attention to + + + align:start position:0% +it on the table and I draw attention to +what this pigmentation looks like and + + align:start position:0% +what this pigmentation looks like and + + + align:start position:0% +what this pigmentation looks like and +and what it sounds like to talk like + + align:start position:0% +and what it sounds like to talk like + + + align:start position:0% +and what it sounds like to talk like +this you know or if I talk like this or + + align:start position:0% +this you know or if I talk like this or + + + align:start position:0% +this you know or if I talk like this or +I haven't so the idea of how accents + + align:start position:0% +I haven't so the idea of how accents + + + align:start position:0% +I haven't so the idea of how accents +inform and influence biases that's it + + align:start position:0% +inform and influence biases that's it + + + align:start position:0% +inform and influence biases that's it +day one I say so how do you sound when + + align:start position:0% +day one I say so how do you sound when + + + align:start position:0% +day one I say so how do you sound when +you talk to your students how does your + + align:start position:0% +you talk to your students how does your + + + align:start position:0% +you talk to your students how does your +your language how does the way you dress + + align:start position:0% +your language how does the way you dress + + + align:start position:0% +your language how does the way you dress +speak to your students and also how do + + align:start position:0% +speak to your students and also how do + + + align:start position:0% +speak to your students and also how do +you respond to your students based on + + align:start position:0% +you respond to your students based on + + + align:start position:0% +you respond to your students based on +what they sound like and what they day + + align:start position:0% +what they sound like and what they day + + + align:start position:0% +what they sound like and what they day +one and you wouldn't be you that's not + + align:start position:0% +one and you wouldn't be you that's not + + + align:start position:0% +one and you wouldn't be you that's not +keyed to the age or level of the so this + + align:start position:0% +keyed to the age or level of the so this + + + align:start position:0% +keyed to the age or level of the so this +becomes part of what it means to be a + + align:start position:0% +becomes part of what it means to be a + + + align:start position:0% +becomes part of what it means to be a +teacher we so if you're interested in + + align:start position:0% +teacher we so if you're interested in + + + align:start position:0% +teacher we so if you're interested in +teaching learners you have multiple + + align:start position:0% +teaching learners you have multiple + + + align:start position:0% +teaching learners you have multiple +identity from that space but if you're + + align:start position:0% +identity from that space but if you're + + + align:start position:0% +identity from that space but if you're +gonna assume that all learners are + + align:start position:0% +gonna assume that all learners are + + + align:start position:0% +gonna assume that all learners are +learners or learners learners it's much + + align:start position:0% +learners or learners learners it's much + + + align:start position:0% +learners or learners learners it's much +easier you just kind of deliver stuff + + align:start position:0% +easier you just kind of deliver stuff + + + align:start position:0% +easier you just kind of deliver stuff +and expect it to come back in the same + + align:start position:0% +and expect it to come back in the same + + + align:start position:0% +and expect it to come back in the same +way it's not messy at all for the for + + align:start position:0% +way it's not messy at all for the for + + + align:start position:0% +way it's not messy at all for the for +the younger ones so I've I'm also + + align:start position:0% +the younger ones so I've I'm also + + + align:start position:0% +the younger ones so I've I'm also +spending the year this year as an artist + + align:start position:0% +spending the year this year as an artist + + + align:start position:0% +spending the year this year as an artist +and learner in residence at an + + align:start position:0% +and learner in residence at an + + + align:start position:0% +and learner in residence at an +elementary school in my town so I visit + + align:start position:0% +elementary school in my town so I visit + + + align:start position:0% +elementary school in my town so I visit +the first grader the class of first + + align:start position:0% +the first grader the class of first + + + align:start position:0% +the first grader the class of first +graders just about every Friday and then + + align:start position:0% +graders just about every Friday and then + + + align:start position:0% +graders just about every Friday and then +I'm working with the entire third grade + + align:start position:0% +I'm working with the entire third grade + + + align:start position:0% +I'm working with the entire third grade +team no that's okay + + align:start position:0% +team no that's okay + + + align:start position:0% +team no that's okay +yeah well it's funny you say that + + align:start position:0% +yeah well it's funny you say that + + + align:start position:0% +yeah well it's funny you say that +because one of the things I'm doing I do + + align:start position:0% +because one of the things I'm doing I do + + + align:start position:0% +because one of the things I'm doing I do +with I've been doing with the 3rd + + align:start position:0% +with I've been doing with the 3rd + + + align:start position:0% +with I've been doing with the 3rd +graders is looking at the water crisis + + align:start position:0% +graders is looking at the water crisis + + + align:start position:0% +graders is looking at the water crisis +and I know several of you some of you + + align:start position:0% +and I know several of you some of you + + + align:start position:0% +and I know several of you some of you +are interested in the water crisis + + align:start position:0% +are interested in the water crisis + + + align:start position:0% +are interested in the water crisis +global water crisis so in third grade + + align:start position:0% +global water crisis so in third grade + + + align:start position:0% +global water crisis so in third grade +Africa is their social one of their + + align:start position:0% +Africa is their social one of their + + + align:start position:0% +Africa is their social one of their +social studies units it worked out + + align:start position:0% +social studies units it worked out + + + align:start position:0% +social studies units it worked out +really quite well in connection with the + + align:start position:0% +really quite well in connection with the + + + align:start position:0% +really quite well in connection with the +African Diaspora water curriculum that + + align:start position:0% +African Diaspora water curriculum that + + + align:start position:0% +African Diaspora water curriculum that +I've been working on that was funded by + + align:start position:0% +I've been working on that was funded by + + + align:start position:0% +I've been working on that was funded by +the African a Research Center and stayed + + align:start position:0% +the African a Research Center and stayed + + + align:start position:0% +the African a Research Center and stayed +and so we talked about so to talk to + + align:start position:0% +and so we talked about so to talk to + + + align:start position:0% +and so we talked about so to talk to +them about the water crisis in Africa if + + align:start position:0% +them about the water crisis in Africa if + + + align:start position:0% +them about the water crisis in Africa if +there's a moment in which for some + + align:start position:0% +there's a moment in which for some + + + align:start position:0% +there's a moment in which for some +learners and for some teachers there + + align:start position:0% +learners and for some teachers there + + + align:start position:0% +learners and for some teachers there +could be in a moment where you equate + + align:start position:0% +could be in a moment where you equate + + + align:start position:0% +could be in a moment where you equate +Africa no water all Africans have no + + align:start position:0% +Africa no water all Africans have no + + + align:start position:0% +Africa no water all Africans have no +water right I have to call that out + + align:start position:0% +water right I have to call that out + + + align:start position:0% +water right I have to call that out +there's also a moment where and this + + align:start position:0% +there's also a moment where and this + + + align:start position:0% +there's also a moment where and this +happens beyond third-grade where it + + align:start position:0% +happens beyond third-grade where it + + + align:start position:0% +happens beyond third-grade where it +happens in the news happens in TV shows + + align:start position:0% +happens in the news happens in TV shows + + + align:start position:0% +happens in the news happens in TV shows +it happens in textbooks it happens in + + align:start position:0% +it happens in textbooks it happens in + + + align:start position:0% +it happens in textbooks it happens in +daily conversation where people will say + + align:start position:0% +daily conversation where people will say + + + align:start position:0% +daily conversation where people will say +I'm going on a trip multiple places I'm + + align:start position:0% +I'm going on a trip multiple places I'm + + + align:start position:0% +I'm going on a trip multiple places I'm +going to fly to France and I'm gonna go + + align:start position:0% +going to fly to France and I'm gonna go + + + align:start position:0% +going to fly to France and I'm gonna go +to Germany and I'm gonna go to Africa + + align:start position:0% +to Germany and I'm gonna go to Africa + + + align:start position:0% +to Germany and I'm gonna go to Africa +really you're gonna go to a country + + align:start position:0% +really you're gonna go to a country + + + align:start position:0% +really you're gonna go to a country +country continent where we frame Africa + + align:start position:0% +country continent where we frame Africa + + + align:start position:0% +country continent where we frame Africa +as an entire country and for those third + + align:start position:0% +as an entire country and for those third + + + align:start position:0% +as an entire country and for those third +graders to learn that to learn what I + + align:start position:0% +graders to learn that to learn what I + + + align:start position:0% +graders to learn that to learn what I +mean by that to learn that Africa is a + + align:start position:0% +mean by that to learn that Africa is a + + + align:start position:0% +mean by that to learn that Africa is a +country know Africa is one continent + + align:start position:0% +country know Africa is one continent + + + align:start position:0% +country know Africa is one continent +made of multiple countries somehow that + + align:start position:0% +made of multiple countries somehow that + + + align:start position:0% +made of multiple countries somehow that +doesn't always happen these think it's + + align:start position:0% +doesn't always happen these think it's + + + align:start position:0% +doesn't always happen these think it's +and so the the the message then in + + align:start position:0% +and so the the the message then in + + + align:start position:0% +and so the the the message then in +society is one that needs to be attended + + align:start position:0% +society is one that needs to be attended + + + align:start position:0% +society is one that needs to be attended +to right I mean it certainly then lends + + align:start position:0% +to right I mean it certainly then lends + + + align:start position:0% +to right I mean it certainly then lends +itself to two biases or + + align:start position:0% +itself to two biases or + + + align:start position:0% +itself to two biases or +misunderstandings about about the + + align:start position:0% +misunderstandings about about the + + + align:start position:0% +misunderstandings about about the +continent so I make it clear that I made + + align:start position:0% +continent so I make it clear that I made + + + align:start position:0% +continent so I make it clear that I made +quite a third-grader so but this is how + + align:start position:0% +quite a third-grader so but this is how + + + align:start position:0% +quite a third-grader so but this is how +I do it so and I put a map of Africa I + + align:start position:0% +I do it so and I put a map of Africa I + + + align:start position:0% +I do it so and I put a map of Africa I +would say so here's the country of + + align:start position:0% +would say so here's the country of + + + align:start position:0% +would say so here's the country of +Africa and we're gonna talk no what do + + align:start position:0% +Africa and we're gonna talk no what do + + + align:start position:0% +Africa and we're gonna talk no what do +you mean it's not with a little bit of + + align:start position:0% +you mean it's not with a little bit of + + + align:start position:0% +you mean it's not with a little bit of +joking with a little teasing to make + + align:start position:0% +joking with a little teasing to make + + + align:start position:0% +joking with a little teasing to make +sure and I may enable them and allow + + align:start position:0% +sure and I may enable them and allow + + + align:start position:0% +sure and I may enable them and allow +them to make explicit what their what + + align:start position:0% +them to make explicit what their what + + + align:start position:0% +them to make explicit what their what +they're hearing and to continue to do + + align:start position:0% +they're hearing and to continue to do + + + align:start position:0% +they're hearing and to continue to do +that is quite important Walter Bateman + + align:start position:0% +that is quite important Walter Bateman + + + align:start position:0% +that is quite important Walter Bateman +there's a book by walter Bateman he + + align:start position:0% +there's a book by walter Bateman he + + + align:start position:0% +there's a book by walter Bateman he +wrote I think after he retired from + + align:start position:0% +wrote I think after he retired from + + + align:start position:0% +wrote I think after he retired from +College of Education he was at + + align:start position:0% +College of Education he was at + + + align:start position:0% +College of Education he was at +university Minnesota it's called + + align:start position:0% +university Minnesota it's called + + + align:start position:0% +university Minnesota it's called +teaching through inquiry and one of the + + align:start position:0% +teaching through inquiry and one of the + + + align:start position:0% +teaching through inquiry and one of the +strategies that he uses that I borrow or + + align:start position:0% +strategies that he uses that I borrow or + + + align:start position:0% +strategies that he uses that I borrow or +he writes about in this book is you know + + align:start position:0% +he writes about in this book is you know + + + align:start position:0% +he writes about in this book is you know +it's it's kind of it's based on the + + align:start position:0% +it's it's kind of it's based on the + + + align:start position:0% +it's it's kind of it's based on the +Socratic method but it's also based in + + align:start position:0% +Socratic method but it's also based in + + + align:start position:0% +Socratic method but it's also based in +this notion of inquiry through the + + align:start position:0% +this notion of inquiry through the + + + align:start position:0% +this notion of inquiry through the +process + + align:start position:0% +process + + + align:start position:0% +process +asking questions one can reveal but to + + align:start position:0% +asking questions one can reveal but to + + + align:start position:0% +asking questions one can reveal but to +make sure students are paying attention + + align:start position:0% +make sure students are paying attention + + + align:start position:0% +make sure students are paying attention +you can you know provide information + + align:start position:0% +you can you know provide information + + + align:start position:0% +you can you know provide information +that's factual factual not factual + + align:start position:0% +that's factual factual not factual + + + align:start position:0% +that's factual factual not factual +factual and see when and how they pick + + align:start position:0% +factual and see when and how they pick + + + align:start position:0% +factual and see when and how they pick +up on it and I love doing that with the + + align:start position:0% +up on it and I love doing that with the + + + align:start position:0% +up on it and I love doing that with the +younger kids or when it's time to share + + align:start position:0% +younger kids or when it's time to share + + + align:start position:0% +younger kids or when it's time to share +so then another component is I've been + + align:start position:0% +so then another component is I've been + + + align:start position:0% +so then another component is I've been +sharing with the students challenges + + align:start position:0% +sharing with the students challenges + + + align:start position:0% +sharing with the students challenges +design challenges that are drawn + + align:start position:0% +design challenges that are drawn + + + align:start position:0% +design challenges that are drawn +directly from lack of access to adequate + + align:start position:0% +directly from lack of access to adequate + + + align:start position:0% +directly from lack of access to adequate +access to water in different countries + + align:start position:0% +access to water in different countries + + + align:start position:0% +access to water in different countries +in Africa as exemplified in in you know + + align:start position:0% +in Africa as exemplified in in you know + + + align:start position:0% +in Africa as exemplified in in you know +from different different places so + + align:start position:0% +from different different places so + + + align:start position:0% +from different different places so +whether it's the water filter or pumping + + align:start position:0% +whether it's the water filter or pumping + + + align:start position:0% +whether it's the water filter or pumping +water or piping water or transporting + + align:start position:0% +water or piping water or transporting + + + align:start position:0% +water or piping water or transporting +water or collecting water out of the air + + align:start position:0% +water or collecting water out of the air + + + align:start position:0% +water or collecting water out of the air +through the moisture so I said look you + + align:start position:0% +through the moisture so I said look you + + + align:start position:0% +through the moisture so I said look you +know here's an example imagine you live + + align:start position:0% +know here's an example imagine you live + + + align:start position:0% +know here's an example imagine you live +in a rural town and you have an amazing + + align:start position:0% +in a rural town and you have an amazing + + + align:start position:0% +in a rural town and you have an amazing +access to to water but it's filled with + + align:start position:0% +access to to water but it's filled with + + + align:start position:0% +access to to water but it's filled with +disease and mosquito larvae and all this + + align:start position:0% +disease and mosquito larvae and all this + + + align:start position:0% +disease and mosquito larvae and all this +design I'd like you to design a way to + + align:start position:0% +design I'd like you to design a way to + + + align:start position:0% +design I'd like you to design a way to +filter that water but you can't use any + + align:start position:0% +filter that water but you can't use any + + + align:start position:0% +filter that water but you can't use any +electricity you can't use any oil or any + + align:start position:0% +electricity you can't use any oil or any + + + align:start position:0% +electricity you can't use any oil or any +gasps no no no no motive motion or power + + align:start position:0% +gasps no no no no motive motion or power + + + align:start position:0% +gasps no no no no motive motion or power +other than your human human body + + align:start position:0% +other than your human human body + + + align:start position:0% +other than your human human body +divided into group of two three four and + + align:start position:0% +divided into group of two three four and + + + align:start position:0% +divided into group of two three four and +draw this and I give them ten minutes + + align:start position:0% +draw this and I give them ten minutes + + + align:start position:0% +draw this and I give them ten minutes +maybe eight-year-olds right + + align:start position:0% +maybe eight-year-olds right + + + align:start position:0% +maybe eight-year-olds right +eight nine you're up then they go away + + align:start position:0% +eight nine you're up then they go away + + + align:start position:0% +eight nine you're up then they go away +and they draw and then when they share + + align:start position:0% +and they draw and then when they share + + + align:start position:0% +and they draw and then when they share +these things this is the same challenge + + align:start position:0% +these things this is the same challenge + + + align:start position:0% +these things this is the same challenge +that you give that designers are dealing + + align:start position:0% +that you give that designers are dealing + + + align:start position:0% +that you give that designers are dealing +with in the world right now the drawings + + align:start position:0% +with in the world right now the drawings + + + align:start position:0% +with in the world right now the drawings +are incredible their design the + + align:start position:0% +are incredible their design the + + + align:start position:0% +are incredible their design the +conversations they're having are + + align:start position:0% +conversations they're having are + + + align:start position:0% +conversations they're having are +incredible but the way I frame it is + + align:start position:0% +incredible but the way I frame it is + + + align:start position:0% +incredible but the way I frame it is +imagine you lived in a town blah blah + + align:start position:0% +imagine you lived in a town blah blah + + + align:start position:0% +imagine you lived in a town blah blah +blah blah I don't say matter you lived + + align:start position:0% +blah blah I don't say matter you lived + + + align:start position:0% +blah blah I don't say matter you lived +in this African village and to take it + + align:start position:0% +in this African village and to take it + + + align:start position:0% +in this African village and to take it +away from that although although they + + align:start position:0% +away from that although although they + + + align:start position:0% +away from that although although they +are studying Africa I take it away from + + align:start position:0% +are studying Africa I take it away from + + + align:start position:0% +are studying Africa I take it away from +that and make it a more generic space + + align:start position:0% +that and make it a more generic space + + + align:start position:0% +that and make it a more generic space +for than to think through then I say + + align:start position:0% +for than to think through then I say + + + align:start position:0% +for than to think through then I say +well you know in certain countries in + + align:start position:0% +well you know in certain countries in + + + align:start position:0% +well you know in certain countries in +Africa this is the case just like in + + align:start position:0% +Africa this is the case just like in + + + align:start position:0% +Africa this is the case just like in +certain states in this country just like + + align:start position:0% +certain states in this country just like + + + align:start position:0% +certain states in this country just like +in other countries in the world so I + + align:start position:0% +in other countries in the world so I + + + align:start position:0% +in other countries in the world so I +don't just leave it there making it + + align:start position:0% +don't just leave it there making it + + + align:start position:0% +don't just leave it there making it +explicit with the students is very very + + align:start position:0% +explicit with the students is very very + + + align:start position:0% +explicit with the students is very very +important and they gonna get it I'm + + align:start position:0% +important and they gonna get it I'm + + + align:start position:0% +important and they gonna get it I'm +still on this idea that there's this + + align:start position:0% +still on this idea that there's this + + + align:start position:0% +still on this idea that there's this +special quality + + align:start position:0% +special quality + + + align:start position:0% +special quality +about social being a socially disruptive + + align:start position:0% +about social being a socially disruptive + + + align:start position:0% +about social being a socially disruptive +artist or being a teacher who's trying + + align:start position:0% +artist or being a teacher who's trying + + + align:start position:0% +artist or being a teacher who's trying +to take this into account and it's it + + align:start position:0% +to take this into account and it's it + + + align:start position:0% +to take this into account and it's it +all the other things that we try to help + + align:start position:0% +all the other things that we try to help + + + align:start position:0% +all the other things that we try to help +people get better at teaching or better + + align:start position:0% +people get better at teaching or better + + + align:start position:0% +people get better at teaching or better +at doing something doesn't get at this + + align:start position:0% +at doing something doesn't get at this + + + align:start position:0% +at doing something doesn't get at this +core and quality could I think it is + + align:start position:0% +core and quality could I think it is + + + align:start position:0% +core and quality could I think it is +different and special and scary and oh I + + align:start position:0% +different and special and scary and oh I + + + align:start position:0% +different and special and scary and oh I +think it's yeah I think it's all of + + align:start position:0% +think it's yeah I think it's all of + + + align:start position:0% +think it's yeah I think it's all of +those things I also maybe you recall I + + align:start position:0% +those things I also maybe you recall I + + + align:start position:0% +those things I also maybe you recall I +said you know like when I'm doing the + + align:start position:0% +said you know like when I'm doing the + + + align:start position:0% +said you know like when I'm doing the +water fountain work I still get anxious + + align:start position:0% +water fountain work I still get anxious + + + align:start position:0% +water fountain work I still get anxious +yeah so you don't know all off and + + align:start position:0% +yeah so you don't know all off and + + + align:start position:0% +yeah so you don't know all off and +bellies they might do this watching all + + align:start position:0% +bellies they might do this watching all + + + align:start position:0% +bellies they might do this watching all +these YouTube videos tells me you know + + align:start position:0% +these YouTube videos tells me you know + + + align:start position:0% +these YouTube videos tells me you know +people mr. Buggs all the time but it's + + align:start position:0% +people mr. Buggs all the time but it's + + + align:start position:0% +people mr. Buggs all the time but it's +but it's it's the social engagement that + + align:start position:0% +but it's it's the social engagement that + + + align:start position:0% +but it's it's the social engagement that +is an important part of the materiality + + align:start position:0% +is an important part of the materiality + + + align:start position:0% +is an important part of the materiality +of that work just like clay is an + + align:start position:0% +of that work just like clay is an + + + align:start position:0% +of that work just like clay is an +important material part of ceramics + + align:start position:0% +important material part of ceramics + + + align:start position:0% +important material part of ceramics +obviously and not everybody is as able + + align:start position:0% +obviously and not everybody is as able + + + align:start position:0% +obviously and not everybody is as able +and with all media as they would like to + + align:start position:0% +and with all media as they would like to + + + align:start position:0% +and with all media as they would like to +be or teaching and learning certain + + align:start position:0% +be or teaching and learning certain + + + align:start position:0% +be or teaching and learning certain +content so that's just an understanding + + align:start position:0% +content so that's just an understanding + + + align:start position:0% +content so that's just an understanding +what this is different in kind than + + align:start position:0% +what this is different in kind than + + + align:start position:0% +what this is different in kind than +learning another medium + + align:start position:0% +learning another medium + + + align:start position:0% +learning another medium +I'm terrible terrible terrible + + align:start position:0% +I'm terrible terrible terrible + + + align:start position:0% +I'm terrible terrible terrible +watercolor but watch me go when I do + + align:start position:0% +watercolor but watch me go when I do + + + align:start position:0% +watercolor but watch me go when I do +something else okay I can get better at + + align:start position:0% +something else okay I can get better at + + + align:start position:0% +something else okay I can get better at +it you can teach me to get better at it + + align:start position:0% +it you can teach me to get better at it + + + align:start position:0% +it you can teach me to get better at it +isn't I'm not great at it it I've never + + align:start position:0% +isn't I'm not great at it it I've never + + + align:start position:0% +isn't I'm not great at it it I've never +been good at it but okay if I put enough + + align:start position:0% +been good at it but okay if I put enough + + + align:start position:0% +been good at it but okay if I put enough +effort in and you give me coaching and I + + align:start position:0% +effort in and you give me coaching and I + + + align:start position:0% +effort in and you give me coaching and I +try it and I watch it I'll get better I + + align:start position:0% +try it and I watch it I'll get better I + + + align:start position:0% +try it and I watch it I'll get better I +just have a sense that being ready to + + align:start position:0% +just have a sense that being ready to + + + align:start position:0% +just have a sense that being ready to +commit to engage in public spaces in + + align:start position:0% +commit to engage in public spaces in + + + align:start position:0% +commit to engage in public spaces in +something aimed at changing the way + + align:start position:0% +something aimed at changing the way + + + align:start position:0% +something aimed at changing the way +people think about things who are + + align:start position:0% +people think about things who are + + + align:start position:0% +people think about things who are +challenging their identity is not + + align:start position:0% +challenging their identity is not + + + align:start position:0% +challenging their identity is not +something that you can build the + + align:start position:0% +something that you can build the + + + align:start position:0% +something that you can build the +capacity in the same way like so this is + + align:start position:0% +capacity in the same way like so this is + + + align:start position:0% +capacity in the same way like so this is +this I want to answer this question + + align:start position:0% +this I want to answer this question + + + align:start position:0% +this I want to answer this question +another way because I think we're going + + align:start position:0% +another way because I think we're going + + + align:start position:0% +another way because I think we're going +around on this the same question and I + + align:start position:0% +around on this the same question and I + + + align:start position:0% +around on this the same question and I +appreciate the provocations so if I + + align:start position:0% +appreciate the provocations so if I + + + align:start position:0% +appreciate the provocations so if I +think about the most recent + + align:start position:0% +think about the most recent + + + align:start position:0% +think about the most recent +semester where I taught the + + align:start position:0% +semester where I taught the + + + align:start position:0% +semester where I taught the +participatory inquiry course a range of + + align:start position:0% +participatory inquiry course a range of + + + align:start position:0% +participatory inquiry course a range of +students in this course one student from + + align:start position:0% +students in this course one student from + + + align:start position:0% +students in this course one student from +I believe she + + align:start position:0% +I believe she + + + align:start position:0% +I believe she +she's in sociology or comparative + + align:start position:0% +she's in sociology or comparative + + + align:start position:0% +she's in sociology or comparative +literature perhaps comparative + + align:start position:0% +literature perhaps comparative + + + align:start position:0% +literature perhaps comparative +literature was not about to perform you + + align:start position:0% +literature was not about to perform you + + + align:start position:0% +literature was not about to perform you +know to do the reading in public but it + + align:start position:0% +know to do the reading in public but it + + + align:start position:0% +know to do the reading in public but it +was very interested in graphic novels + + align:start position:0% +was very interested in graphic novels + + + align:start position:0% +was very interested in graphic novels +comics visual representation and was all + + align:start position:0% +comics visual representation and was all + + + align:start position:0% +comics visual representation and was all +in the issue she was interested in was + + align:start position:0% +in the issue she was interested in was + + + align:start position:0% +in the issue she was interested in was +this conversation on campus about + + align:start position:0% + + + + align:start position:0% + +unionizing graduate students right and + + align:start position:0% +unionizing graduate students right and + + + align:start position:0% +unionizing graduate students right and +so it was kind of concern about how do I + + align:start position:0% +so it was kind of concern about how do I + + + align:start position:0% +so it was kind of concern about how do I +perform unionizing and the political + + align:start position:0% +perform unionizing and the political + + + align:start position:0% +perform unionizing and the political +issues there and and so we talked about + + align:start position:0% +issues there and and so we talked about + + + align:start position:0% +issues there and and so we talked about +her interest in graphic novels and + + align:start position:0% +her interest in graphic novels and + + + align:start position:0% +her interest in graphic novels and +comics and what she ended up doing was + + align:start position:0% +comics and what she ended up doing was + + + align:start position:0% +comics and what she ended up doing was +essentially it was a survey of sorts + + align:start position:0% +essentially it was a survey of sorts + + + align:start position:0% +essentially it was a survey of sorts +asking people to provide her with + + align:start position:0% +asking people to provide her with + + + align:start position:0% +asking people to provide her with +feedback their perspective on this on + + align:start position:0% +feedback their perspective on this on + + + align:start position:0% +feedback their perspective on this on +this issue on unionization of grad + + align:start position:0% +this issue on unionization of grad + + + align:start position:0% +this issue on unionization of grad +students and with little drop boxes + + align:start position:0% +students and with little drop boxes + + + align:start position:0% +students and with little drop boxes +where they could you know it's almost + + align:start position:0% +where they could you know it's almost + + + align:start position:0% +where they could you know it's almost +like there's the suggestion boxes right + + align:start position:0% +like there's the suggestion boxes right + + + align:start position:0% +like there's the suggestion boxes right +and she put them in strategic places + + align:start position:0% +and she put them in strategic places + + + align:start position:0% +and she put them in strategic places +collected them and then had made graphic + + align:start position:0% +collected them and then had made graphic + + + align:start position:0% +collected them and then had made graphic +you know visual representations almost + + align:start position:0% +you know visual representations almost + + + align:start position:0% +you know visual representations almost +like cartoon each on these squares + + align:start position:0% +like cartoon each on these squares + + + align:start position:0% +like cartoon each on these squares +panels and then post with with the the + + align:start position:0% +panels and then post with with the the + + + align:start position:0% +panels and then post with with the the +speech bubbles of the content as the the + + align:start position:0% +speech bubbles of the content as the the + + + align:start position:0% +speech bubbles of the content as the the +cut that was the content from those + + align:start position:0% +cut that was the content from those + + + align:start position:0% +cut that was the content from those +suggestions the anonymous suggestions + + align:start position:0% +suggestions the anonymous suggestions + + + align:start position:0% +suggestions the anonymous suggestions +that people gave her and then she would + + align:start position:0% +that people gave her and then she would + + + align:start position:0% +that people gave her and then she would +post these on bulletin boards so you + + align:start position:0% +post these on bulletin boards so you + + + align:start position:0% +post these on bulletin boards so you +could see this public display of + + align:start position:0% +could see this public display of + + + align:start position:0% +could see this public display of +comments she physically put this in the + + align:start position:0% +comments she physically put this in the + + + align:start position:0% +comments she physically put this in the +world but she didn't physically put + + align:start position:0% +world but she didn't physically put + + + align:start position:0% +world but she didn't physically put +herself in the world does that make + + align:start position:0% +herself in the world does that make + + + align:start position:0% +herself in the world does that make +sense yes so we're playing to her + + align:start position:0% +sense yes so we're playing to her + + + align:start position:0% +sense yes so we're playing to her +strengths that well and that's why the + + align:start position:0% +strengths that well and that's why the + + + align:start position:0% +strengths that well and that's why the +the particulars of what she was about + + align:start position:0% +the particulars of what she was about + + + align:start position:0% +the particulars of what she was about +when she was interested in which I was + + align:start position:0% +when she was interested in which I was + + + align:start position:0% +when she was interested in which I was +capable that's what that woman this + + align:start position:0% +capable that's what that woman this + + + align:start position:0% +capable that's what that woman this +other another student who was an + + align:start position:0% +other another student who was an + + + align:start position:0% +other another student who was an +architecture was interested in so on our + + align:start position:0% +architecture was interested in so on our + + + align:start position:0% +architecture was interested in so on our +campus I don't know how it happens + + align:start position:0% +campus I don't know how it happens + + + align:start position:0% +campus I don't know how it happens +around Cambridge and around MIT but we + + align:start position:0% +around Cambridge and around MIT but we + + + align:start position:0% +around Cambridge and around MIT but we +have a different representatives from + + align:start position:0% +have a different representatives from + + + align:start position:0% +have a different representatives from +different religions or different beliefs + + align:start position:0% +different religions or different beliefs + + + align:start position:0% +different religions or different beliefs +who will set up in different parts of + + align:start position:0% +who will set up in different parts of + + + align:start position:0% +who will set up in different parts of +campus and they're allowed to do that + + align:start position:0% +campus and they're allowed to do that + + + align:start position:0% +campus and they're allowed to do that +and they'll pass out literature and and + + align:start position:0% +and they'll pass out literature and and + + + align:start position:0% +and they'll pass out literature and and +they'll engage people in conversation + + align:start position:0% +they'll engage people in conversation + + + align:start position:0% +they'll engage people in conversation +and so what this one student did well + + align:start position:0% +and so what this one student did well + + + align:start position:0% +and so what this one student did well +he wanted he wanted to emulate their he + + align:start position:0% +he wanted he wanted to emulate their he + + + align:start position:0% +he wanted he wanted to emulate their he +want to borrow their their mode their + + align:start position:0% +want to borrow their their mode their + + + align:start position:0% +want to borrow their their mode their +presentation but not their message he + + align:start position:0% +presentation but not their message he + + + align:start position:0% +presentation but not their message he +wanted to actually substitute out their + + align:start position:0% +wanted to actually substitute out their + + + align:start position:0% +wanted to actually substitute out their +message of religion and spirituality + + align:start position:0% +message of religion and spirituality + + + align:start position:0% +message of religion and spirituality +with concepts from architecture and so + + align:start position:0% +with concepts from architecture and so + + + align:start position:0% +with concepts from architecture and so +he exactly so instead so imagine you + + align:start position:0% +he exactly so instead so imagine you + + + align:start position:0% +he exactly so instead so imagine you +walking down the sidewalk and someone + + align:start position:0% +walking down the sidewalk and someone + + + align:start position:0% +walking down the sidewalk and someone +says oh may I talk to you about you know + + align:start position:0% +says oh may I talk to you about you know + + + align:start position:0% +says oh may I talk to you about you know +being saved or may I talk to you about + + align:start position:0% +being saved or may I talk to you about + + + align:start position:0% +being saved or may I talk to you about +you know really spiritual enlightenment + + align:start position:0% +you know really spiritual enlightenment + + + align:start position:0% +you know really spiritual enlightenment +or whatever and then instead of doing + + align:start position:0% +or whatever and then instead of doing + + + align:start position:0% +or whatever and then instead of doing +that he said you know do you have a + + align:start position:0% +that he said you know do you have a + + + align:start position:0% +that he said you know do you have a +moment because I'd like to talk to you + + align:start position:0% +moment because I'd like to talk to you + + + align:start position:0% +moment because I'd like to talk to you +about the differences between concrete + + align:start position:0% +about the differences between concrete + + + align:start position:0% +about the differences between concrete +and cement and their uses in + + align:start position:0% +and cement and their uses in + + + align:start position:0% +and cement and their uses in +architectural structures but he's + + align:start position:0% +architectural structures but he's + + + align:start position:0% +architectural structures but he's +dressed as it I was like a really a + + align:start position:0% +dressed as it I was like a really a + + + align:start position:0% +dressed as it I was like a really a +mighty thing right but he's dressed as + + align:start position:0% +mighty thing right but he's dressed as + + + align:start position:0% +mighty thing right but he's dressed as +as someone that you might see on campus + + align:start position:0% +as someone that you might see on campus + + + align:start position:0% +as someone that you might see on campus +in the guise of a spiritual or religious + + align:start position:0% +in the guise of a spiritual or religious + + + align:start position:0% +in the guise of a spiritual or religious +practice so in that way he felt very + + align:start position:0% +practice so in that way he felt very + + + align:start position:0% +practice so in that way he felt very +comfortable doing that but it was about + + align:start position:0% +comfortable doing that but it was about + + + align:start position:0% +comfortable doing that but it was about +well how do we how do you how do you + + align:start position:0% +well how do we how do you how do you + + + align:start position:0% +well how do we how do you how do you +take on that persona without my wasn't + + align:start position:0% +take on that persona without my wasn't + + + align:start position:0% +take on that persona without my wasn't +trying to trying to use that that visual + + align:start position:0% +trying to trying to use that that visual + + + align:start position:0% +trying to trying to use that that visual +as as momentum and so played to his + + align:start position:0% +as as momentum and so played to his + + + align:start position:0% +as as momentum and so played to his +strengths you play tonight people's + + align:start position:0% +strengths you play tonight people's + + + align:start position:0% +strengths you play tonight people's +there's a lot of ways of doing this + + align:start position:0% +there's a lot of ways of doing this + + + align:start position:0% +there's a lot of ways of doing this +you're playing to people's strengths + + align:start position:0% +you're playing to people's strengths + + + align:start position:0% +you're playing to people's strengths +that's what it's about now + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/vc5dotshPZc.txt b/vc5dotshPZc.txt new file mode 100644 index 0000000000000000000000000000000000000000..eecd15354a153417a82c95711192bda75c20581a --- /dev/null +++ b/vc5dotshPZc.txt @@ -0,0 +1,15179 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +So, I welcome comments or questions at + + align:start position:0% +So, I welcome comments or questions at + + + align:start position:0% +So, I welcome comments or questions at +any point during this talk. We have an + + align:start position:0% +any point during this talk. We have an + + + align:start position:0% +any point during this talk. We have an +hour and a half and I have only 50 + + align:start position:0% +hour and a half and I have only 50 + + + align:start position:0% +hour and a half and I have only 50 +slides so we should be okay. So um this + + align:start position:0% +slides so we should be okay. So um this + + + align:start position:0% +slides so we should be okay. So um this +this is joint work with uh Jim Mingu + + align:start position:0% +this is joint work with uh Jim Mingu + + + align:start position:0% +this is joint work with uh Jim Mingu +who's a colleague of mine in my group at + + align:start position:0% +who's a colleague of mine in my group at + + + align:start position:0% +who's a colleague of mine in my group at +Morgan Stanley. I head up the global + + align:start position:0% +Morgan Stanley. I head up the global + + + align:start position:0% +Morgan Stanley. I head up the global +market modeling team at Morgan Stanley. + + align:start position:0% +market modeling team at Morgan Stanley. + + + align:start position:0% +market modeling team at Morgan Stanley. +It's a group of about 70 PhDs mostly + + align:start position:0% +It's a group of about 70 PhDs mostly + + + align:start position:0% +It's a group of about 70 PhDs mostly +spread around the world. Um there's + + align:start position:0% +spread around the world. Um there's + + + align:start position:0% +spread around the world. Um there's +about 30 of us in New York. Um some in + + align:start position:0% +about 30 of us in New York. Um some in + + + align:start position:0% +about 30 of us in New York. Um some in +London quite a few in Budapest and a few + + align:start position:0% +London quite a few in Budapest and a few + + + align:start position:0% +London quite a few in Budapest and a few +in Beijing. The title of this talk is + + align:start position:0% +in Beijing. The title of this talk is + + + align:start position:0% +in Beijing. The title of this talk is +can we recover and um it's um meant as a + + align:start position:0% +can we recover and um it's um meant as a + + + align:start position:0% +can we recover and um it's um meant as a +triple entandra. So uh it could refer to + + align:start position:0% +triple entandra. So uh it could refer to + + + align:start position:0% +triple entandra. So uh it could refer to +either the systemic risk arising from + + align:start position:0% +either the systemic risk arising from + + + align:start position:0% +either the systemic risk arising from +the credit crisis + + align:start position:0% +the credit crisis + + + align:start position:0% +the credit crisis +or the main result in a recent paper by + + align:start position:0% +or the main result in a recent paper by + + + align:start position:0% +or the main result in a recent paper by +a professor here at MIT named Steve Ross + + align:start position:0% +a professor here at MIT named Steve Ross + + + align:start position:0% +a professor here at MIT named Steve Ross +in the Sloan School or it could actually + + align:start position:0% +in the Sloan School or it could actually + + + align:start position:0% +in the Sloan School or it could actually +be uh the academic and practitioner + + align:start position:0% +be uh the academic and practitioner + + + align:start position:0% +be uh the academic and practitioner +reaction to this result. So um so it's + + align:start position:0% +reaction to this result. So um so it's + + + align:start position:0% +reaction to this result. So um so it's +really about two and three. So uh so um + + align:start position:0% +really about two and three. So uh so um + + + align:start position:0% +really about two and three. So uh so um +not about can we recover from the crisis + + align:start position:0% +not about can we recover from the crisis + + + align:start position:0% +not about can we recover from the crisis +and um so + + align:start position:0% +and um so + + + align:start position:0% +and um so +um there's a professor at Sloan School + + align:start position:0% +um there's a professor at Sloan School + + + align:start position:0% +um there's a professor at Sloan School +named Steven Ross and he's um very well + + align:start position:0% +named Steven Ross and he's um very well + + + align:start position:0% +named Steven Ross and he's um very well +known in academic finance. Uh so uh your + + align:start position:0% +known in academic finance. Uh so uh your + + + align:start position:0% +known in academic finance. Uh so uh your +professor was kind enough to mention + + align:start position:0% +professor was kind enough to mention + + + align:start position:0% +professor was kind enough to mention +that I won financial engineer of the + + align:start position:0% +that I won financial engineer of the + + + align:start position:0% +that I won financial engineer of the +year and that was uh two years ago. Uh I + + align:start position:0% +year and that was uh two years ago. Uh I + + + align:start position:0% +year and that was uh two years ago. Uh I +was like the 20th winner. he was the + + align:start position:0% +was like the 20th winner. he was the + + + align:start position:0% +was like the 20th winner. he was the +second winner. So, uh, so anyway, uh, + + align:start position:0% +second winner. So, uh, so anyway, uh, + + + align:start position:0% +second winner. So, uh, so anyway, uh, +the, um, and, um, the first winner was + + align:start position:0% +the, um, and, um, the first winner was + + + align:start position:0% +the, um, and, um, the first winner was +another MIT professor, Bob Merin. So, + + align:start position:0% +another MIT professor, Bob Merin. So, + + + align:start position:0% +another MIT professor, Bob Merin. So, +um, so anyway, the, + + align:start position:0% +um, so anyway, the, + + + align:start position:0% +um, so anyway, the, +um, he wrote a paper a couple years ago + + align:start position:0% +um, he wrote a paper a couple years ago + + + align:start position:0% +um, he wrote a paper a couple years ago +and it's only now about to be published. + + align:start position:0% +and it's only now about to be published. + + + align:start position:0% +and it's only now about to be published. +So, it takes this is like typical in + + align:start position:0% +So, it takes this is like typical in + + + align:start position:0% +So, it takes this is like typical in +academic circles. It takes a long time + + align:start position:0% +academic circles. It takes a long time + + + align:start position:0% +academic circles. It takes a long time +for a paper to come out. + + align:start position:0% +for a paper to come out. + + + align:start position:0% +for a paper to come out. +And um this paper's coming out in + + align:start position:0% +And um this paper's coming out in + + + align:start position:0% +And um this paper's coming out in +journal of finance. That's what JF + + align:start position:0% +journal of finance. That's what JF + + + align:start position:0% +journal of finance. That's what JF +stands for. And uh journal of finance is + + align:start position:0% +stands for. And uh journal of finance is + + + align:start position:0% +stands for. And uh journal of finance is +the main uh journal for the academic + + align:start position:0% +the main uh journal for the academic + + + align:start position:0% +the main uh journal for the academic +finance community. + + align:start position:0% +finance community. + + + align:start position:0% +finance community. +And um the title of the paper is the + + align:start position:0% +And um the title of the paper is the + + + align:start position:0% +And um the title of the paper is the +recovery theorem and that's also the + + align:start position:0% +recovery theorem and that's also the + + + align:start position:0% +recovery theorem and that's also the +title of the theorem one in his paper. + + align:start position:0% +title of the theorem one in his paper. + + + align:start position:0% +title of the theorem one in his paper. +And that theorem one we'll go over and + + align:start position:0% +And that theorem one we'll go over and + + + align:start position:0% +And that theorem one we'll go over and +it gives a sufficient set of conditions + + align:start position:0% +it gives a sufficient set of conditions + + + align:start position:0% +it gives a sufficient set of conditions +under which what professor Ross calls + + align:start position:0% +under which what professor Ross calls + + + align:start position:0% +under which what professor Ross calls +natural probabilities + + align:start position:0% +natural probabilities + + + align:start position:0% +natural probabilities +at a point in time can be determined + + align:start position:0% +at a point in time can be determined + + + align:start position:0% +at a point in time can be determined +from + + align:start position:0% +from + + + align:start position:0% +from +okay mathematically from exact knowledge + + align:start position:0% +okay mathematically from exact knowledge + + + align:start position:0% +okay mathematically from exact knowledge +of aerody security prices which you + + align:start position:0% +of aerody security prices which you + + + align:start position:0% +of aerody security prices which you +probably don't know what they are but + + align:start position:0% +probably don't know what they are but + + + align:start position:0% +probably don't know what they are but +less mathematically we'll just say from + + align:start position:0% +less mathematically we'll just say from + + + align:start position:0% +less mathematically we'll just say from +market prices of derivatives. Okay, so + + align:start position:0% +market prices of derivatives. Okay, so + + + align:start position:0% +market prices of derivatives. Okay, so +derivatives you've heard of I'm sure + + align:start position:0% +derivatives you've heard of I'm sure + + + align:start position:0% +derivatives you've heard of I'm sure +things like options for example on + + align:start position:0% +things like options for example on + + + align:start position:0% +things like options for example on +stocks or stock indices could be on + + align:start position:0% +stocks or stock indices could be on + + + align:start position:0% +stocks or stock indices could be on +currencies. + + align:start position:0% +currencies. + + + align:start position:0% +currencies. +So the imagine that you look at + + align:start position:0% +So the imagine that you look at + + + align:start position:0% +So the imagine that you look at +Bloomberg, Bloomberg publishes a whole + + align:start position:0% +Bloomberg, Bloomberg publishes a whole + + + align:start position:0% +Bloomberg, Bloomberg publishes a whole +bunch of prices and the idea is that you + + align:start position:0% +bunch of prices and the idea is that you + + + align:start position:0% +bunch of prices and the idea is that you +take this information + + align:start position:0% +take this information + + + align:start position:0% +take this information +and from it you're learning what the + + align:start position:0% +and from it you're learning what the + + + align:start position:0% +and from it you're learning what the +market believes are the probabilities of + + align:start position:0% +market believes are the probabilities of + + + align:start position:0% +market believes are the probabilities of +the future concerning the future and um + + align:start position:0% +the future concerning the future and um + + + align:start position:0% +the future concerning the future and um +so if the option is on S&P 500 stock + + align:start position:0% +so if the option is on S&P 500 stock + + + align:start position:0% +so if the option is on S&P 500 stock +index then you're learning from options + + align:start position:0% +index then you're learning from options + + + align:start position:0% +index then you're learning from options +prices what the market believes are the + + align:start position:0% +prices what the market believes are the + + + align:start position:0% +prices what the market believes are the +likelihoods of various possible levels + + align:start position:0% +likelihoods of various possible levels + + + align:start position:0% +likelihoods of various possible levels +for the S&P 500. Okay. And um + + align:start position:0% +for the S&P 500. Okay. And um + + + align:start position:0% +for the S&P 500. Okay. And um +so + + align:start position:0% + + + + align:start position:0% + +you um + + align:start position:0% +you um + + + align:start position:0% +you um +so we take these this information on + + align:start position:0% +so we take these this information on + + + align:start position:0% +so we take these this information on +Bloomberg and truth be told we use it + + align:start position:0% +Bloomberg and truth be told we use it + + + align:start position:0% +Bloomberg and truth be told we use it +along with some assumptions to extract + + align:start position:0% +along with some assumptions to extract + + + align:start position:0% +along with some assumptions to extract +these implied market probabilities. + + align:start position:0% +these implied market probabilities. + + + align:start position:0% +these implied market probabilities. +Okay. So I want to tell you what those + + align:start position:0% +Okay. So I want to tell you what those + + + align:start position:0% +Okay. So I want to tell you what those +assumptions are. + + align:start position:0% +assumptions are. + + + align:start position:0% +assumptions are. +And um so the the actual output of this + + align:start position:0% +And um so the the actual output of this + + + align:start position:0% +And um so the the actual output of this +analysis is a probability transition + + align:start position:0% +analysis is a probability transition + + + align:start position:0% +analysis is a probability transition +matrix or if you do it in continuous + + align:start position:0% +matrix or if you do it in continuous + + + align:start position:0% +matrix or if you do it in continuous +time you call it a in continuous state + + align:start position:0% +time you call it a in continuous state + + + align:start position:0% +time you call it a in continuous state +space you'd call it a transition + + align:start position:0% +space you'd call it a transition + + + align:start position:0% +space you'd call it a transition +probability density function. Okay. So + + align:start position:0% +probability density function. Okay. So + + + align:start position:0% +probability density function. Okay. So +the key word there is transition. And + + align:start position:0% +the key word there is transition. And + + + align:start position:0% +the key word there is transition. And +what transition means is you're getting + + align:start position:0% +what transition means is you're getting + + + align:start position:0% +what transition means is you're getting +not only the probabilities of going from + + align:start position:0% +not only the probabilities of going from + + + align:start position:0% +not only the probabilities of going from +say the current S&P level + + align:start position:0% +say the current S&P level + + + align:start position:0% +say the current S&P level +to any one of several levels, but even + + align:start position:0% +to any one of several levels, but even + + + align:start position:0% +to any one of several levels, but even +the probabilities of going from some + + align:start position:0% +the probabilities of going from some + + + align:start position:0% +the probabilities of going from some +other level than we're presently at + + align:start position:0% +other level than we're presently at + + + align:start position:0% +other level than we're presently at +today to those to that range of levels. + + align:start position:0% +today to those to that range of levels. + + + align:start position:0% +today to those to that range of levels. +So you can answer the question. So you + + align:start position:0% +So you can answer the question. So you + + + align:start position:0% +So you can answer the question. So you +can say for example the market believes + + align:start position:0% +can say for example the market believes + + + align:start position:0% +can say for example the market believes +that given that we're here now with S&P + + align:start position:0% +that given that we're here now with S&P + + + align:start position:0% +that given that we're here now with S&P +at say 1500 + + align:start position:0% +at say 1500 + + + align:start position:0% +at say 1500 +that um the probability of more than + + align:start position:0% +that um the probability of more than + + + align:start position:0% +that um the probability of more than +doubling is um one half okay for + + align:start position:0% +doubling is um one half okay for + + + align:start position:0% +doubling is um one half okay for +example. Okay I mean which is which + + align:start position:0% +example. Okay I mean which is which + + + align:start position:0% +example. Okay I mean which is which +would be really high but you know I'm + + align:start position:0% +would be really high but you know I'm + + + align:start position:0% +would be really high but you know I'm +just picking numbers randomly here. And + + align:start position:0% +just picking numbers randomly here. And + + + align:start position:0% +just picking numbers randomly here. And +um and you can even say that if S&P were + + align:start position:0% +um and you can even say that if S&P were + + + align:start position:0% +um and you can even say that if S&P were +to drop instantaneously + + align:start position:0% +to drop instantaneously + + + align:start position:0% +to drop instantaneously +to half its level that the probability + + align:start position:0% +to half its level that the probability + + + align:start position:0% +to half its level that the probability +of more than doubling from there is say + + align:start position:0% +of more than doubling from there is say + + + align:start position:0% +of more than doubling from there is say +one/3. Okay. So so you can answer + + align:start position:0% +one/3. Okay. So so you can answer + + + align:start position:0% +one/3. Okay. So so you can answer +questions like that. That's the output + + align:start position:0% +questions like that. That's the output + + + align:start position:0% +questions like that. That's the output +of this type of thinking. + + align:start position:0% + + + + align:start position:0% + +So there'll be three + + align:start position:0% +So there'll be three + + + align:start position:0% +So there'll be three +probability measures that we can be + + align:start position:0% +probability measures that we can be + + + align:start position:0% +probability measures that we can be +thinking about and we'll call them PQ + + align:start position:0% +thinking about and we'll call them PQ + + + align:start position:0% +thinking about and we'll call them PQ +and R and I'd like to tell you what each + + align:start position:0% +and R and I'd like to tell you what each + + + align:start position:0% +and R and I'd like to tell you what each +of them means. So P stands for physical + + align:start position:0% +of them means. So P stands for physical + + + align:start position:0% +of them means. So P stands for physical +probability measure. So the P is for + + align:start position:0% +probability measure. So the P is for + + + align:start position:0% +probability measure. So the P is for +physical and um think of that as the + + align:start position:0% +physical and um think of that as the + + + align:start position:0% +physical and um think of that as the +actual objective reality of future + + align:start position:0% +actual objective reality of future + + + align:start position:0% +actual objective reality of future +of future states for say S&P 500. So, so + + align:start position:0% +of future states for say S&P 500. So, so + + + align:start position:0% +of future states for say S&P 500. So, so +like let's say you know God knows that + + align:start position:0% +like let's say you know God knows that + + + align:start position:0% +like let's say you know God knows that +for example + + align:start position:0% +for example + + + align:start position:0% +for example +um the probability that S&P is up by the + + align:start position:0% +um the probability that S&P is up by the + + + align:start position:0% +um the probability that S&P is up by the +end of the year is 1/2 + + align:start position:0% +end of the year is 1/2 + + + align:start position:0% +end of the year is 1/2 +and uh we unfortunately not being God + + align:start position:0% +and uh we unfortunately not being God + + + align:start position:0% +and uh we unfortunately not being God +don't know that but let's say the ide + + align:start position:0% +don't know that but let's say the ide + + + align:start position:0% +don't know that but let's say the ide +the philosophy is that there is some + + align:start position:0% +the philosophy is that there is some + + + align:start position:0% +the philosophy is that there is some +sort of true probability of S&P being up + + align:start position:0% +sort of true probability of S&P being up + + + align:start position:0% +sort of true probability of S&P being up +at the end of the year and um I used + + align:start position:0% +at the end of the year and um I used + + + align:start position:0% +at the end of the year and um I used +let's say I used a half um maybe it's + + align:start position:0% +let's say I used a half um maybe it's + + + align:start position:0% +let's say I used a half um maybe it's +60%. If it is 60% then the probability + + align:start position:0% +60%. If it is 60% then the probability + + + align:start position:0% +60%. If it is 60% then the probability +of S&P being down at the end of the year + + align:start position:0% +of S&P being down at the end of the year + + + align:start position:0% +of S&P being down at the end of the year +is 40%. And um the uh + + align:start position:0% +is 40%. And um the uh + + + align:start position:0% +is 40%. And um the uh +point is is P is meant to indicate kind + + align:start position:0% +point is is P is meant to indicate kind + + + align:start position:0% +point is is P is meant to indicate kind +of + + align:start position:0% +of + + + align:start position:0% +of +the frequencies with which S&P 500 in my + + align:start position:0% +the frequencies with which S&P 500 in my + + + align:start position:0% +the frequencies with which S&P 500 in my +example takes on various values. + + align:start position:0% +example takes on various values. + + + align:start position:0% +example takes on various values. +Now there's another probability measure + + align:start position:0% +Now there's another probability measure + + + align:start position:0% +Now there's another probability measure +that people in derivatives spend a lot + + align:start position:0% +that people in derivatives spend a lot + + + align:start position:0% +that people in derivatives spend a lot +of time working with and that's called + + align:start position:0% +of time working with and that's called + + + align:start position:0% +of time working with and that's called +risk neutral probability measure and + + align:start position:0% +risk neutral probability measure and + + + align:start position:0% +risk neutral probability measure and +it's often denoted by a letter Q. So + + align:start position:0% +it's often denoted by a letter Q. So + + + align:start position:0% +it's often denoted by a letter Q. So +we'll denote it by Q. And um the concept + + align:start position:0% +we'll denote it by Q. And um the concept + + + align:start position:0% +we'll denote it by Q. And um the concept +of a risk neutral probability measure + + align:start position:0% +of a risk neutral probability measure + + + align:start position:0% +of a risk neutral probability measure +was also actually + + align:start position:0% +was also actually + + + align:start position:0% +was also actually +proposed by Steve Ross many years ago. + + align:start position:0% +proposed by Steve Ross many years ago. + + + align:start position:0% +proposed by Steve Ross many years ago. +And um + + align:start position:0% +And um + + + align:start position:0% +And um +it's a um it's called risk neutral + + align:start position:0% +it's a um it's called risk neutral + + + align:start position:0% +it's a um it's called risk neutral +because um + + align:start position:0% +because um + + + align:start position:0% +because um +you uh when you're working with it, if + + align:start position:0% +you uh when you're working with it, if + + + align:start position:0% +you uh when you're working with it, if +you think about how fast prices + + align:start position:0% +you think about how fast prices + + + align:start position:0% +you think about how fast prices +appreciate over time, + + align:start position:0% +appreciate over time, + + + align:start position:0% +appreciate over time, +then they grow randomly, but on average + + align:start position:0% +then they grow randomly, but on average + + + align:start position:0% +then they grow randomly, but on average +under this risk neutral measure Q, they + + align:start position:0% +under this risk neutral measure Q, they + + + align:start position:0% +under this risk neutral measure Q, they +grow at the same rate as your bank + + align:start position:0% +grow at the same rate as your bank + + + align:start position:0% +grow at the same rate as your bank +balance would + + align:start position:0% +balance would + + + align:start position:0% +balance would +Okay. So, um, so your bank balance, + + align:start position:0% +Okay. So, um, so your bank balance, + + + align:start position:0% +Okay. So, um, so your bank balance, +let's say nowadays, is growing at best + + align:start position:0% +let's say nowadays, is growing at best + + + align:start position:0% +let's say nowadays, is growing at best +at the rate of 1%. Okay. And, um, when + + align:start position:0% +at the rate of 1%. Okay. And, um, when + + + align:start position:0% +at the rate of 1%. Okay. And, um, when +you look at + + align:start position:0% +you look at + + + align:start position:0% +you look at +how fast historically stocks have grown, + + align:start position:0% +how fast historically stocks have grown, + + + align:start position:0% +how fast historically stocks have grown, +it's actually much higher on average + + align:start position:0% +it's actually much higher on average + + + align:start position:0% +it's actually much higher on average +than 1%. It's more like about nine. So + + align:start position:0% +than 1%. It's more like about nine. So + + + align:start position:0% +than 1%. It's more like about nine. So +we would call the difference between 9% + + align:start position:0% +we would call the difference between 9% + + + align:start position:0% +we would call the difference between 9% +and 8 and 1%. We call that 8% + + align:start position:0% +and 8 and 1%. We call that 8% + + + align:start position:0% +and 8 and 1%. We call that 8% +differential risk premium. + + align:start position:0% +differential risk premium. + + + align:start position:0% +differential risk premium. +And um + + align:start position:0% +And um + + + align:start position:0% +And um +um let me just pretend there's no + + align:start position:0% +um let me just pretend there's no + + + align:start position:0% +um let me just pretend there's no +dividends to keep life simple when I go + + align:start position:0% +dividends to keep life simple when I go + + + align:start position:0% +dividends to keep life simple when I go +when I say this. So, so the um + + align:start position:0% +when I say this. So, so the um + + + align:start position:0% +when I say this. So, so the um +now um this riskneutral measure is kind + + align:start position:0% +now um this riskneutral measure is kind + + + align:start position:0% +now um this riskneutral measure is kind +of a fictitious probability measure in + + align:start position:0% +of a fictitious probability measure in + + + align:start position:0% +of a fictitious probability measure in +the sense that it's not describing the + + align:start position:0% +the sense that it's not describing the + + + align:start position:0% +the sense that it's not describing the +actual probabilities or frequencies of + + align:start position:0% +actual probabilities or frequencies of + + + align:start position:0% +actual probabilities or frequencies of +of transitions. It's more a device or a + + align:start position:0% +of transitions. It's more a device or a + + + align:start position:0% +of transitions. It's more a device or a +tool or a trick uh that that's handy. + + align:start position:0% +tool or a trick uh that that's handy. + + + align:start position:0% +tool or a trick uh that that's handy. +And one of its properties that causes it + + align:start position:0% +And one of its properties that causes it + + + align:start position:0% +And one of its properties that causes it +to earn the name riskneutral probability + + align:start position:0% +to earn the name riskneutral probability + + + align:start position:0% +to earn the name riskneutral probability +measure is that uh when you look at how + + align:start position:0% +measure is that uh when you look at how + + + align:start position:0% +measure is that uh when you look at how +fast say S&P grows on average under this + + align:start position:0% +fast say S&P grows on average under this + + + align:start position:0% +fast say S&P grows on average under this +risk neutral probability measure Q it + + align:start position:0% +risk neutral probability measure Q it + + + align:start position:0% +risk neutral probability measure Q it +would be growing nowadays at 1%. Okay. + + align:start position:0% +would be growing nowadays at 1%. Okay. + + + align:start position:0% +would be growing nowadays at 1%. Okay. +So the same as your money market as your + + align:start position:0% +So the same as your money market as your + + + align:start position:0% +So the same as your money market as your +bank balance is growing at. + + align:start position:0% +bank balance is growing at. + + + align:start position:0% +bank balance is growing at. +So so the the word riskneutral is meant + + align:start position:0% +So so the the word riskneutral is meant + + + align:start position:0% +So so the the word riskneutral is meant +to indicate that that the growth rate + + align:start position:0% +to indicate that that the growth rate + + + align:start position:0% +to indicate that that the growth rate +under this measure is consistent + + align:start position:0% +under this measure is consistent + + + align:start position:0% +under this measure is consistent +with investors in the economy being risk + + align:start position:0% +with investors in the economy being risk + + + align:start position:0% +with investors in the economy being risk +neutral meaning that they require no + + align:start position:0% +neutral meaning that they require no + + + align:start position:0% +neutral meaning that they require no +premium for bearing risk. Okay. + + align:start position:0% + + + + align:start position:0% + +Now, there's a third probability measure + + align:start position:0% +Now, there's a third probability measure + + + align:start position:0% +Now, there's a third probability measure +that we're going to be talking about + + align:start position:0% +that we're going to be talking about + + + align:start position:0% +that we're going to be talking about +today that actually you won't find any + + align:start position:0% +today that actually you won't find any + + + align:start position:0% +today that actually you won't find any +literature on. Uh, and we're going to + + align:start position:0% +literature on. Uh, and we're going to + + + align:start position:0% +literature on. Uh, and we're going to +call it R since we've already, you know, + + align:start position:0% +call it R since we've already, you know, + + + align:start position:0% +call it R since we've already, you know, +seems like a natural letter to pick + + align:start position:0% +seems like a natural letter to pick + + + align:start position:0% +seems like a natural letter to pick +having already gone through P and Q. + + align:start position:0% +having already gone through P and Q. + + + align:start position:0% +having already gone through P and Q. +And, um, the, um, R measure, + + align:start position:0% +And, um, the, um, R measure, + + + align:start position:0% +And, um, the, um, R measure, +you can think of the R as standing for + + align:start position:0% +you can think of the R as standing for + + + align:start position:0% +you can think of the R as standing for +recovered probability measure. And it's + + align:start position:0% +recovered probability measure. And it's + + + align:start position:0% +recovered probability measure. And it's +going to be the probability measure that + + align:start position:0% +going to be the probability measure that + + + align:start position:0% +going to be the probability measure that +we get from market prices as I was + + align:start position:0% +we get from market prices as I was + + + align:start position:0% +we get from market prices as I was +talking about earlier. + + align:start position:0% +talking about earlier. + + + align:start position:0% +talking about earlier. +And um the uh the operational meaning of + + align:start position:0% +And um the uh the operational meaning of + + + align:start position:0% +And um the uh the operational meaning of +this R measure is it's capturing the + + align:start position:0% +this R measure is it's capturing the + + + align:start position:0% +this R measure is it's capturing the +market's beliefs regarding the future. + + align:start position:0% +market's beliefs regarding the future. + + + align:start position:0% +market's beliefs regarding the future. +But we allow for the possibility that + + align:start position:0% +But we allow for the possibility that + + + align:start position:0% +But we allow for the possibility that +the market could be wrong. So um so if + + align:start position:0% +the market could be wrong. So um so if + + + align:start position:0% +the market could be wrong. So um so if +we were applying this to say houses and + + align:start position:0% +we were applying this to say houses and + + + align:start position:0% +we were applying this to say houses and +housing prices in say 2005, + + align:start position:0% +housing prices in say 2005, + + + align:start position:0% +housing prices in say 2005, +it may well be that if we looked at + + align:start position:0% +it may well be that if we looked at + + + align:start position:0% +it may well be that if we looked at +Bloomberg and got prices of mortgage + + align:start position:0% +Bloomberg and got prices of mortgage + + + align:start position:0% +Bloomberg and got prices of mortgage +back securities + + align:start position:0% +back securities + + + align:start position:0% +back securities +that we would extract an R probability + + align:start position:0% +that we would extract an R probability + + + align:start position:0% +that we would extract an R probability +measure that says housing prices are + + align:start position:0% +measure that says housing prices are + + + align:start position:0% +measure that says housing prices are +going to continue on their you know + + align:start position:0% +going to continue on their you know + + + align:start position:0% +going to continue on their you know +incessant upward trajectory and uh you + + align:start position:0% +incessant upward trajectory and uh you + + + align:start position:0% +incessant upward trajectory and uh you +know we're going to keep growing at the + + align:start position:0% +know we're going to keep growing at the + + + align:start position:0% +know we're going to keep growing at the +rate of say 15% % a year uh each year + + align:start position:0% +rate of say 15% % a year uh each year + + + align:start position:0% +rate of say 15% % a year uh each year +for the next 10 years. Okay, for + + align:start position:0% +for the next 10 years. Okay, for + + + align:start position:0% +for the next 10 years. Okay, for +something like that. So um you know that + + align:start position:0% +something like that. So um you know that + + + align:start position:0% +something like that. So um you know that +could be what the market's beliefs were, + + align:start position:0% +could be what the market's beliefs were, + + + align:start position:0% +could be what the market's beliefs were, +you know, back in 2005. And we know now + + align:start position:0% +you know, back in 2005. And we know now + + + align:start position:0% +you know, back in 2005. And we know now +that those beliefs were wrong if if that + + align:start position:0% +that those beliefs were wrong if if that + + + align:start position:0% +that those beliefs were wrong if if that +was what the market was inferring. Okay. + + align:start position:0% +was what the market was inferring. Okay. + + + align:start position:0% +was what the market was inferring. Okay. +So so I want to allow for at least the + + align:start position:0% +So so I want to allow for at least the + + + align:start position:0% +So so I want to allow for at least the +theoretical possibility that the market + + align:start position:0% +theoretical possibility that the market + + + align:start position:0% +theoretical possibility that the market +could be wrong. Okay? And so that's why + + align:start position:0% +could be wrong. Okay? And so that's why + + + align:start position:0% +could be wrong. Okay? And so that's why +I'm drawing a distinction, let's say, + + align:start position:0% +I'm drawing a distinction, let's say, + + + align:start position:0% +I'm drawing a distinction, let's say, +between the R probability measure that + + align:start position:0% +between the R probability measure that + + + align:start position:0% +between the R probability measure that +captures the market's beliefs and the P + + align:start position:0% +captures the market's beliefs and the P + + + align:start position:0% +captures the market's beliefs and the P +probability measure that captures + + align:start position:0% +probability measure that captures + + + align:start position:0% +probability measure that captures +physical reality. Okay. So now there's a + + align:start position:0% +physical reality. Okay. So now there's a + + + align:start position:0% +physical reality. Okay. So now there's a +lot of people in finance who simply + + align:start position:0% +lot of people in finance who simply + + + align:start position:0% +lot of people in finance who simply +cannot accept the, you know, the + + align:start position:0% +cannot accept the, you know, the + + + align:start position:0% +cannot accept the, you know, the +possibility that the market could be + + align:start position:0% +possibility that the market could be + + + align:start position:0% +possibility that the market could be +wrong. And um for those people, the sort + + align:start position:0% +wrong. And um for those people, the sort + + + align:start position:0% +wrong. And um for those people, the sort +of true believers in market efficiency, + + align:start position:0% +of true believers in market efficiency, + + + align:start position:0% +of true believers in market efficiency, +they're free to set R to P every time + + align:start position:0% +they're free to set R to P every time + + + align:start position:0% +they're free to set R to P every time +they see an R. But I want to um allow + + align:start position:0% +they see an R. But I want to um allow + + + align:start position:0% +they see an R. But I want to um allow +for the possibility that what we recover + + align:start position:0% +for the possibility that what we recover + + + align:start position:0% +for the possibility that what we recover +is not physical probabilities but simply + + align:start position:0% +is not physical probabilities but simply + + + align:start position:0% +is not physical probabilities but simply +the market beliefs. Okay. + + align:start position:0% + + + + align:start position:0% + +And anyway it's kind of semantic. It's + + align:start position:0% +And anyway it's kind of semantic. It's + + + align:start position:0% +And anyway it's kind of semantic. It's +good semantics if the probability + + align:start position:0% +good semantics if the probability + + + align:start position:0% +good semantics if the probability +measure we recover is the one Ross uh uh + + align:start position:0% +measure we recover is the one Ross uh uh + + + align:start position:0% +measure we recover is the one Ross uh uh +said we should get R stands for Ross. + + align:start position:0% +said we should get R stands for Ross. + + + align:start position:0% +said we should get R stands for Ross. +Okay. So, so the um so Ross calls the + + align:start position:0% +Okay. So, so the um so Ross calls the + + + align:start position:0% +Okay. So, so the um so Ross calls the +probability measure that we recover, he + + align:start position:0% +probability measure that we recover, he + + + align:start position:0% +probability measure that we recover, he +calls them natural probability measures + + align:start position:0% +calls them natural probability measures + + + align:start position:0% +calls them natural probability measures +and um well let's say that suggests that + + align:start position:0% +and um well let's say that suggests that + + + align:start position:0% +and um well let's say that suggests that +the risk neutral probability measures + + align:start position:0% +the risk neutral probability measures + + + align:start position:0% +the risk neutral probability measures +are unnatural which um I think is fair + + align:start position:0% +are unnatural which um I think is fair + + + align:start position:0% +are unnatural which um I think is fair +actually because uh when you hear the + + align:start position:0% +actually because uh when you hear the + + + align:start position:0% +actually because uh when you hear the +word probability you tend to think about + + align:start position:0% +word probability you tend to think about + + + align:start position:0% +word probability you tend to think about +frequencies with which events occur and + + align:start position:0% +frequencies with which events occur and + + + align:start position:0% +frequencies with which events occur and +the risk neutral probability measures do + + align:start position:0% +the risk neutral probability measures do + + + align:start position:0% +the risk neutral probability measures do +not give you the frequencies with which + + align:start position:0% +not give you the frequencies with which + + + align:start position:0% +not give you the frequencies with which +events occur. What the risk neutral + + align:start position:0% +events occur. What the risk neutral + + + align:start position:0% +events occur. What the risk neutral +probability measures give you is instead + + align:start position:0% +probability measures give you is instead + + + align:start position:0% +probability measures give you is instead +uh prices of so-called aerodyru + + align:start position:0% +uh prices of so-called aerodyru + + + align:start position:0% +uh prices of so-called aerodyru +securities. So let me give you a sense + + align:start position:0% +securities. So let me give you a sense + + + align:start position:0% +securities. So let me give you a sense +of what that means. So say I tell you + + align:start position:0% +of what that means. So say I tell you + + + align:start position:0% +of what that means. So say I tell you +that the risk neutral probability of S&P + + align:start position:0% +that the risk neutral probability of S&P + + + align:start position:0% +that the risk neutral probability of S&P +500 being up at the end of the year is + + align:start position:0% +500 being up at the end of the year is + + + align:start position:0% +500 being up at the end of the year is +40%. + + align:start position:0% +40%. + + + align:start position:0% +40%. +Um then how should you interpret that? + + align:start position:0% +Um then how should you interpret that? + + + align:start position:0% +Um then how should you interpret that? +Well, you should simply interpret it as + + align:start position:0% +Well, you should simply interpret it as + + + align:start position:0% +Well, you should simply interpret it as +this. Imagine that you can agree now to + + align:start position:0% +this. Imagine that you can agree now to + + + align:start position:0% +this. Imagine that you can agree now to +buy a security that pays $1 just if S&P + + align:start position:0% +buy a security that pays $1 just if S&P + + + align:start position:0% +buy a security that pays $1 just if S&P +500 is up at the end of the year. And um + + align:start position:0% +500 is up at the end of the year. And um + + + align:start position:0% +500 is up at the end of the year. And um +usually when you and I buy things, we + + align:start position:0% +usually when you and I buy things, we + + + align:start position:0% +usually when you and I buy things, we +buy them in a spot market. So we pay now + + align:start position:0% +buy them in a spot market. So we pay now + + + align:start position:0% +buy them in a spot market. So we pay now +for pay now for things. But sometimes + + align:start position:0% +for pay now for things. But sometimes + + + align:start position:0% +for pay now for things. But sometimes +your credit is good and you can actually + + align:start position:0% +your credit is good and you can actually + + + align:start position:0% +your credit is good and you can actually +agree now to pay later. Okay. So, so + + align:start position:0% +agree now to pay later. Okay. So, so + + + align:start position:0% +agree now to pay later. Okay. So, so +we're going to be thinking that you're + + align:start position:0% +we're going to be thinking that you're + + + align:start position:0% +we're going to be thinking that you're +agreeing now to pay later some fixed + + align:start position:0% +agreeing now to pay later some fixed + + + align:start position:0% +agreeing now to pay later some fixed +amount in return for this security + + align:start position:0% +amount in return for this security + + + align:start position:0% +amount in return for this security +that's going to pay you $1 just if S&P + + align:start position:0% +that's going to pay you $1 just if S&P + + + align:start position:0% +that's going to pay you $1 just if S&P +500 is up at the end of the year. + + align:start position:0% +500 is up at the end of the year. + + + align:start position:0% +500 is up at the end of the year. +And if I tell you that the risk neutral + + align:start position:0% +And if I tell you that the risk neutral + + + align:start position:0% +And if I tell you that the risk neutral +probability of S&P 500 being up by the + + align:start position:0% +probability of S&P 500 being up by the + + + align:start position:0% +probability of S&P 500 being up by the +end of the year is 40 cents, what that + + align:start position:0% +end of the year is 40 cents, what that + + + align:start position:0% +end of the year is 40 cents, what that +means financially is that you agree now + + align:start position:0% +means financially is that you agree now + + + align:start position:0% +means financially is that you agree now +to pay 40 cents at the end of the year + + align:start position:0% +to pay 40 cents at the end of the year + + + align:start position:0% +to pay 40 cents at the end of the year +for this security. Okay? + + align:start position:0% + + + + align:start position:0% + +So you can imagine there'd be another + + align:start position:0% +So you can imagine there'd be another + + + align:start position:0% +So you can imagine there'd be another +security that pays a dollar just if S&P + + align:start position:0% +security that pays a dollar just if S&P + + + align:start position:0% +security that pays a dollar just if S&P +500 is down by the end of the year. And + + align:start position:0% +500 is down by the end of the year. And + + + align:start position:0% +500 is down by the end of the year. And +um + + align:start position:0% +um + + + align:start position:0% +um +the only possible price that that + + align:start position:0% +the only possible price that that + + + align:start position:0% +the only possible price that that +security could have in an arbitrage free + + align:start position:0% +security could have in an arbitrage free + + + align:start position:0% +security could have in an arbitrage free +world would be 60s because um if you + + align:start position:0% +world would be 60s because um if you + + + align:start position:0% +world would be 60s because um if you +were to buy both securities then you'd + + align:start position:0% +were to buy both securities then you'd + + + align:start position:0% +were to buy both securities then you'd +have paid a total of 40 cents and 60 + + align:start position:0% +have paid a total of 40 cents and 60 + + + align:start position:0% +have paid a total of 40 cents and 60 +cents. So you're agreeing now to pay a + + align:start position:0% +cents. So you're agreeing now to pay a + + + align:start position:0% +cents. So you're agreeing now to pay a +dollar at the end of the year and then + + align:start position:0% +dollar at the end of the year and then + + + align:start position:0% +dollar at the end of the year and then +having both securities either the S&P is + + align:start position:0% +having both securities either the S&P is + + + align:start position:0% +having both securities either the S&P is +up or S&P is down and so you'll collect + + align:start position:0% +up or S&P is down and so you'll collect + + + align:start position:0% +up or S&P is down and so you'll collect +one dollar from one of them and not the + + align:start position:0% +one dollar from one of them and not the + + + align:start position:0% +one dollar from one of them and not the +other. So um so if for example the the + + align:start position:0% +other. So um so if for example the the + + + align:start position:0% +other. So um so if for example the the +one paying if S&P is up + + align:start position:0% +one paying if S&P is up + + + align:start position:0% +one paying if S&P is up +cost 40 cents while the one paying if + + align:start position:0% +cost 40 cents while the one paying if + + + align:start position:0% +cost 40 cents while the one paying if +S&P is down only costs 50 cents then + + align:start position:0% +S&P is down only costs 50 cents then + + + align:start position:0% +S&P is down only costs 50 cents then +there would be an arbitrage which would + + align:start position:0% +there would be an arbitrage which would + + + align:start position:0% +there would be an arbitrage which would +be to buy both securities pay only agree + + align:start position:0% +be to buy both securities pay only agree + + + align:start position:0% +be to buy both securities pay only agree +now to pay 90 cents and then get a + + align:start position:0% +now to pay 90 cents and then get a + + + align:start position:0% +now to pay 90 cents and then get a +dollar for sure at the end of the + + align:start position:0% +dollar for sure at the end of the + + + align:start position:0% +dollar for sure at the end of the +period. So be up 10 cents by the end of + + align:start position:0% +period. So be up 10 cents by the end of + + + align:start position:0% +period. So be up 10 cents by the end of +the year. Question these are similar to + + align:start position:0% +the year. Question these are similar to + + + align:start position:0% +the year. Question these are similar to +digital options. Yes they're it's more + + align:start position:0% +digital options. Yes they're it's more + + + align:start position:0% +digital options. Yes they're it's more +than similar. They are digital options. + + align:start position:0% +than similar. They are digital options. + + + align:start position:0% +than similar. They are digital options. +Yeah. Yeah. So uh so so that's right. So + + align:start position:0% +Yeah. Yeah. So uh so so that's right. So + + + align:start position:0% +Yeah. Yeah. So uh so so that's right. So +that's another term which I actually use + + align:start position:0% +that's another term which I actually use + + + align:start position:0% +that's another term which I actually use +on the next slide. So that's that's + + align:start position:0% +on the next slide. So that's that's + + + align:start position:0% +on the next slide. So that's that's +exactly right. So you know digital + + align:start position:0% +exactly right. So you know digital + + + align:start position:0% +exactly right. So you know digital +options is just too good a term. So + + align:start position:0% +options is just too good a term. So + + + align:start position:0% +options is just too good a term. So +economists in order to offiscate and + + align:start position:0% +economists in order to offiscate and + + + align:start position:0% +economists in order to offiscate and +look smart call them aerodyue + + align:start position:0% +look smart call them aerodyue + + + align:start position:0% +look smart call them aerodyue +securities. Okay. So + + align:start position:0% + + + + align:start position:0% + +okay. Um so continuing with the + + align:start position:0% +okay. Um so continuing with the + + + align:start position:0% +okay. Um so continuing with the +obfiscation uh I want to tell you about + + align:start position:0% +obfiscation uh I want to tell you about + + + align:start position:0% +obfiscation uh I want to tell you about +a world with a representative agent. So + + align:start position:0% +a world with a representative agent. So + + + align:start position:0% +a world with a representative agent. So +um the um so the there's this so + + align:start position:0% +um the um so the there's this so + + + align:start position:0% +um the um so the there's this so +economists are fond of of trying to + + align:start position:0% +economists are fond of of trying to + + + align:start position:0% +economists are fond of of trying to +formally + + align:start position:0% +formally + + + align:start position:0% +formally +model the market. Okay. So I think you + + align:start position:0% +model the market. Okay. So I think you + + + align:start position:0% +model the market. Okay. So I think you +know you read the newspaper every day + + align:start position:0% +know you read the newspaper every day + + + align:start position:0% +know you read the newspaper every day +you'll read something like market + + align:start position:0% +you'll read something like market + + + align:start position:0% +you'll read something like market +thought that um you know stocks are no + + align:start position:0% +thought that um you know stocks are no + + + align:start position:0% +thought that um you know stocks are no +longer a good investment. And so there + + align:start position:0% +longer a good investment. And so there + + + align:start position:0% +longer a good investment. And so there +was a sell-off. Um now um + + align:start position:0% +was a sell-off. Um now um + + + align:start position:0% +was a sell-off. Um now um +market is a nice short word to capture + + align:start position:0% +market is a nice short word to capture + + + align:start position:0% +market is a nice short word to capture +what people are thinking. And so + + align:start position:0% +what people are thinking. And so + + + align:start position:0% +what people are thinking. And so +economists rather than say the market + + align:start position:0% +economists rather than say the market + + + align:start position:0% +economists rather than say the market +will say there's a world with a + + align:start position:0% +will say there's a world with a + + + align:start position:0% +will say there's a world with a +representative agent. So this + + align:start position:0% +representative agent. So this + + + align:start position:0% +representative agent. So this +representative agent is a fictitious + + align:start position:0% +representative agent is a fictitious + + + align:start position:0% +representative agent is a fictitious +investor who + + align:start position:0% +investor who + + + align:start position:0% +investor who +um + + align:start position:0% +um + + + align:start position:0% +um +who has all the mathematical properties + + align:start position:0% +who has all the mathematical properties + + + align:start position:0% +who has all the mathematical properties +that we give an investor such as a + + align:start position:0% +that we give an investor such as a + + + align:start position:0% +that we give an investor such as a +utility function and an endowment and so + + align:start position:0% +utility function and an endowment and so + + + align:start position:0% +utility function and an endowment and so +on. And um what makes this particular + + align:start position:0% +on. And um what makes this particular + + + align:start position:0% +on. And um what makes this particular +investor a representative agent is that + + align:start position:0% +investor a representative agent is that + + + align:start position:0% +investor a representative agent is that +this agent sort of finds that current + + align:start position:0% +this agent sort of finds that current + + + align:start position:0% +this agent sort of finds that current +prices are such that it's optimal + + align:start position:0% +prices are such that it's optimal + + + align:start position:0% +prices are such that it's optimal +to um hold exactly what's available in + + align:start position:0% +to um hold exactly what's available in + + + align:start position:0% +to um hold exactly what's available in +the amount that is available. Okay. So + + align:start position:0% +the amount that is available. Okay. So + + + align:start position:0% +the amount that is available. Okay. So +um so let's say + + align:start position:0% +um so let's say + + + align:start position:0% +um so let's say +um if if what's on offer is uh you know + + align:start position:0% +um if if what's on offer is uh you know + + + align:start position:0% +um if if what's on offer is uh you know +let's say uh some Google shares and some + + align:start position:0% +let's say uh some Google shares and some + + + align:start position:0% +let's say uh some Google shares and some +Apple shares and some IBM shares and and + + align:start position:0% +Apple shares and some IBM shares and and + + + align:start position:0% +Apple shares and some IBM shares and and +um and if we take the uh the total + + align:start position:0% +um and if we take the uh the total + + + align:start position:0% +um and if we take the uh the total +market cap of Google total market cap of + + align:start position:0% +market cap of Google total market cap of + + + align:start position:0% +market cap of Google total market cap of +Apple total market cap of IBM uh and + + align:start position:0% +Apple total market cap of IBM uh and + + + align:start position:0% +Apple total market cap of IBM uh and +let's say Apple's biggest I think I + + align:start position:0% +let's say Apple's biggest I think I + + + align:start position:0% +let's say Apple's biggest I think I +don't know I I don't actually know + + align:start position:0% +don't know I I don't actually know + + + align:start position:0% +don't know I I don't actually know +whether Google's bigger or IBM but let's + + align:start position:0% +whether Google's bigger or IBM but let's + + + align:start position:0% +whether Google's bigger or IBM but let's +say it's Google and than IBM. Um the um + + align:start position:0% +say it's Google and than IBM. Um the um + + + align:start position:0% +say it's Google and than IBM. Um the um +so let's just say Apple's biggest than + + align:start position:0% +so let's just say Apple's biggest than + + + align:start position:0% +so let's just say Apple's biggest than +Google than IBM. Well, this investor + + align:start position:0% +Google than IBM. Well, this investor + + + align:start position:0% +Google than IBM. Well, this investor +would actually find that it's it's + + align:start position:0% +would actually find that it's it's + + + align:start position:0% +would actually find that it's it's +optimal for him to have mo most of his + + align:start position:0% +optimal for him to have mo most of his + + + align:start position:0% +optimal for him to have mo most of his +money in Apple, second most amount of + + align:start position:0% +money in Apple, second most amount of + + + align:start position:0% +money in Apple, second most amount of +his money in Google, third most amount + + align:start position:0% +his money in Google, third most amount + + + align:start position:0% +his money in Google, third most amount +of his money in IBM. That's the + + align:start position:0% +of his money in IBM. That's the + + + align:start position:0% +of his money in IBM. That's the +representative agent. Okay. So he he's + + align:start position:0% +representative agent. Okay. So he he's + + + align:start position:0% +representative agent. Okay. So he he's +be he's acting in the way the whole + + align:start position:0% +be he's acting in the way the whole + + + align:start position:0% +be he's acting in the way the whole +economy is acting. Okay. + + align:start position:0% +economy is acting. Okay. + + + align:start position:0% +economy is acting. Okay. +Well, + + align:start position:0% +Well, + + + align:start position:0% +Well, +um I I've been working in Wall Street + + align:start position:0% +um I I've been working in Wall Street + + + align:start position:0% +um I I've been working in Wall Street +now since 1996. I have yet to hear a + + align:start position:0% +now since 1996. I have yet to hear a + + + align:start position:0% +now since 1996. I have yet to hear a +trader tell me about a representative + + align:start position:0% +trader tell me about a representative + + + align:start position:0% +trader tell me about a representative +agent. And uh so um so anyway, so + + align:start position:0% +agent. And uh so um so anyway, so + + + align:start position:0% +agent. And uh so um so anyway, so +although I understand what the words + + align:start position:0% +although I understand what the words + + + align:start position:0% +although I understand what the words +mean and even the math, uh I wanted to + + align:start position:0% +mean and even the math, uh I wanted to + + + align:start position:0% +mean and even the math, uh I wanted to +present this material in a way that + + align:start position:0% +present this material in a way that + + + align:start position:0% +present this material in a way that +let's say at least quantitative traders + + align:start position:0% +let's say at least quantitative traders + + + align:start position:0% +let's say at least quantitative traders +could understand it. So um so I try to + + align:start position:0% +could understand it. So um so I try to + + + align:start position:0% +could understand it. So um so I try to +get away from representative agents and + + align:start position:0% +get away from representative agents and + + + align:start position:0% +get away from representative agents and +um and present these ideas in the + + align:start position:0% +um and present these ideas in the + + + align:start position:0% +um and present these ideas in the +language that uh at least quants on Wall + + align:start position:0% +language that uh at least quants on Wall + + + align:start position:0% +language that uh at least quants on Wall +Street are familiar with. So um + + align:start position:0% +Street are familiar with. So um + + + align:start position:0% +Street are familiar with. So um +so + + align:start position:0% +so + + + align:start position:0% +so +uh so I won't be talking about a + + align:start position:0% +uh so I won't be talking about a + + + align:start position:0% +uh so I won't be talking about a +representative agent and I will be + + align:start position:0% +representative agent and I will be + + + align:start position:0% +representative agent and I will be +talking instead + + align:start position:0% +talking instead + + + align:start position:0% +talking instead +about something that's probably not too + + align:start position:0% +about something that's probably not too + + + align:start position:0% +about something that's probably not too +familiar to you but at least quants have + + align:start position:0% +familiar to you but at least quants have + + + align:start position:0% +familiar to you but at least quants have +heard of and that would be something + + align:start position:0% +heard of and that would be something + + + align:start position:0% +heard of and that would be something +called numer portfolio and it also goes + + align:start position:0% +called numer portfolio and it also goes + + + align:start position:0% +called numer portfolio and it also goes +by other names. + + align:start position:0% +by other names. + + + align:start position:0% +by other names. +Another name is growth optimal portfolio + + align:start position:0% +Another name is growth optimal portfolio + + + align:start position:0% +Another name is growth optimal portfolio +and even has a third name which is + + align:start position:0% +and even has a third name which is + + + align:start position:0% +and even has a third name which is +called natural numerator. And these are + + align:start position:0% +called natural numerator. And these are + + + align:start position:0% +called natural numerator. And these are +three different phrases that all + + align:start position:0% +three different phrases that all + + + align:start position:0% +three different phrases that all +describe the same mathematical object. + + align:start position:0% +describe the same mathematical object. + + + align:start position:0% +describe the same mathematical object. +And this mathematical object is + + align:start position:0% +And this mathematical object is + + + align:start position:0% +And this mathematical object is +a portfolio + + align:start position:0% +a portfolio + + + align:start position:0% +a portfolio +and more precisely it's the value of a + + align:start position:0% +and more precisely it's the value of a + + + align:start position:0% +and more precisely it's the value of a +portfolio + + align:start position:0% +portfolio + + + align:start position:0% +portfolio +that has some nice properties. So the + + align:start position:0% +that has some nice properties. So the + + + align:start position:0% +that has some nice properties. So the +growth optimal portfolio indicates one + + align:start position:0% +growth optimal portfolio indicates one + + + align:start position:0% +growth optimal portfolio indicates one +of its properties. + + align:start position:0% +of its properties. + + + align:start position:0% +of its properties. +uh this portfolio has a very nice + + align:start position:0% +uh this portfolio has a very nice + + + align:start position:0% +uh this portfolio has a very nice +property which is that in the long run + + align:start position:0% +property which is that in the long run + + + align:start position:0% +property which is that in the long run +meaning over an infinite horizon + + align:start position:0% +meaning over an infinite horizon + + + align:start position:0% +meaning over an infinite horizon +the uh growth rate of this portfolio is + + align:start position:0% +the uh growth rate of this portfolio is + + + align:start position:0% +the uh growth rate of this portfolio is +first of all random but second if you + + align:start position:0% +first of all random but second if you + + + align:start position:0% +first of all random but second if you +take the mean of that random growth rate + + align:start position:0% +take the mean of that random growth rate + + + align:start position:0% +take the mean of that random growth rate +that mean is actually the largest + + align:start position:0% +that mean is actually the largest + + + align:start position:0% +that mean is actually the largest +possible among all portfolios. Okay. So + + align:start position:0% +possible among all portfolios. Okay. So + + + align:start position:0% +possible among all portfolios. Okay. So +um so starting with Kelly in 1956 + + align:start position:0% +um so starting with Kelly in 1956 + + + align:start position:0% +um so starting with Kelly in 1956 +uh this particular portfolio with the + + align:start position:0% +uh this particular portfolio with the + + + align:start position:0% +uh this particular portfolio with the +largest mean growth rate over an + + align:start position:0% +largest mean growth rate over an + + + align:start position:0% +largest mean growth rate over an +infinite horizon has you know has let's + + align:start position:0% +infinite horizon has you know has let's + + + align:start position:0% +infinite horizon has you know has let's +say received a lot of attention. Um it's + + align:start position:0% +say received a lot of attention. Um it's + + + align:start position:0% +say received a lot of attention. Um it's +actually quite humorous some of this + + align:start position:0% +actually quite humorous some of this + + + align:start position:0% +actually quite humorous some of this +attention that it's received. Uh so + + align:start position:0% +attention that it's received. Uh so + + + align:start position:0% +attention that it's received. Uh so +Kelly was a physicist who worked at Bell + + align:start position:0% +Kelly was a physicist who worked at Bell + + + align:start position:0% +Kelly was a physicist who worked at Bell +Labs and um he was actually + + align:start position:0% +Labs and um he was actually + + + align:start position:0% +Labs and um he was actually +um a colleague of Shannon's at Bell + + align:start position:0% +um a colleague of Shannon's at Bell + + + align:start position:0% +um a colleague of Shannon's at Bell +Labs. So Shannon did his seinal work at + + align:start position:0% +Labs. So Shannon did his seinal work at + + + align:start position:0% +Labs. So Shannon did his seinal work at +Bell Labs but actually came here after + + align:start position:0% +Bell Labs but actually came here after + + + align:start position:0% +Bell Labs but actually came here after +that and um + + align:start position:0% +that and um + + + align:start position:0% +that and um +and well you know his ideas in uh really + + align:start position:0% +and well you know his ideas in uh really + + + align:start position:0% +and well you know his ideas in uh really +caught on and um especially and I'd say + + align:start position:0% +caught on and um especially and I'd say + + + align:start position:0% +caught on and um especially and I'd say +started the field of information science + + align:start position:0% +started the field of information science + + + align:start position:0% +started the field of information science +we'll call it whatever and um let's say + + align:start position:0% +we'll call it whatever and um let's say + + + align:start position:0% +we'll call it whatever and um let's say +but Kelly was applying these ideas to + + align:start position:0% +but Kelly was applying these ideas to + + + align:start position:0% +but Kelly was applying these ideas to +finance and certain financial economists + + align:start position:0% +finance and certain financial economists + + + align:start position:0% +finance and certain financial economists +were less than enthused + + align:start position:0% +were less than enthused + + + align:start position:0% +were less than enthused +about the application of information + + align:start position:0% +about the application of information + + + align:start position:0% +about the application of information +theory to finance. So in particular, + + align:start position:0% +theory to finance. So in particular, + + + align:start position:0% +theory to finance. So in particular, +there was a financial economist here + + align:start position:0% +there was a financial economist here + + + align:start position:0% +there was a financial economist here +named Paul Samuelson who was a who + + align:start position:0% +named Paul Samuelson who was a who + + + align:start position:0% +named Paul Samuelson who was a who +championed, I guess, the opposition to + + align:start position:0% +championed, I guess, the opposition to + + + align:start position:0% +championed, I guess, the opposition to +to this Kelly um criterion it's called. + + align:start position:0% +to this Kelly um criterion it's called. + + + align:start position:0% +to this Kelly um criterion it's called. +And uh so I'll just tell you short + + align:start position:0% +And uh so I'll just tell you short + + + align:start position:0% +And uh so I'll just tell you short +story. So um yeah, if I could just + + align:start position:0% +story. So um yeah, if I could just + + + align:start position:0% +story. So um yeah, if I could just +interject. Yeah, sure. We had mentioned + + align:start position:0% +interject. Yeah, sure. We had mentioned + + + align:start position:0% +interject. Yeah, sure. We had mentioned +in an earlier class the book Fortunes + + align:start position:0% +in an earlier class the book Fortunes + + + align:start position:0% +in an earlier class the book Fortunes +Formula. Yes. And this book goes into a + + align:start position:0% +Formula. Yes. And this book goes into a + + + align:start position:0% +Formula. Yes. And this book goes into a +lot of background and storytelling about + + align:start position:0% +lot of background and storytelling about + + + align:start position:0% +lot of background and storytelling about +this whole era and exchanges. So anyway, + + align:start position:0% +this whole era and exchanges. So anyway, + + + align:start position:0% +this whole era and exchanges. So anyway, +that's true. Just it's a fantastic book. + + align:start position:0% +that's true. Just it's a fantastic book. + + + align:start position:0% +that's true. Just it's a fantastic book. +I've read it. I loved it. Uh it's uh + + align:start position:0% +I've read it. I loved it. Uh it's uh + + + align:start position:0% +I've read it. I loved it. Uh it's uh +especially if you're at MIT, you should + + align:start position:0% +especially if you're at MIT, you should + + + align:start position:0% +especially if you're at MIT, you should +definitely read this book because uh it + + align:start position:0% +definitely read this book because uh it + + + align:start position:0% +definitely read this book because uh it +talks about a lot of MIT professors and + + align:start position:0% +talks about a lot of MIT professors and + + + align:start position:0% +talks about a lot of MIT professors and +um some of whom are still here like Bob + + align:start position:0% +um some of whom are still here like Bob + + + align:start position:0% +um some of whom are still here like Bob +Mertin and um so uh it's a it's a quick + + align:start position:0% +Mertin and um so uh it's a it's a quick + + + align:start position:0% +Mertin and um so uh it's a it's a quick +easy read. You don't you don't even have + + align:start position:0% +easy read. You don't you don't even have + + + align:start position:0% +easy read. You don't you don't even have +to have a background in finance to + + align:start position:0% +to have a background in finance to + + + align:start position:0% +to have a background in finance to +really enjoy it. So uh so uh so there's + + align:start position:0% +really enjoy it. So uh so uh so there's + + + align:start position:0% +really enjoy it. So uh so uh so there's +a you can read about uh the story I'm + + align:start position:0% +a you can read about uh the story I'm + + + align:start position:0% +a you can read about uh the story I'm +going to tell you now in that book. Uh + + align:start position:0% +going to tell you now in that book. Uh + + + align:start position:0% +going to tell you now in that book. Uh +so the story is + + align:start position:0% +so the story is + + + align:start position:0% +so the story is +uh Samuelson grew a little tired I guess + + align:start position:0% +uh Samuelson grew a little tired I guess + + + align:start position:0% +uh Samuelson grew a little tired I guess +of trying to explain to these dumb + + align:start position:0% +of trying to explain to these dumb + + + align:start position:0% +of trying to explain to these dumb +information theorists that this Kelly + + align:start position:0% +information theorists that this Kelly + + + align:start position:0% +information theorists that this Kelly +criterion was not so great. So he + + align:start position:0% +criterion was not so great. So he + + + align:start position:0% +criterion was not so great. So he +published an article in a journal called + + align:start position:0% +published an article in a journal called + + + align:start position:0% +published an article in a journal called +Journal of Banking and Finance that's + + align:start position:0% +Journal of Banking and Finance that's + + + align:start position:0% +Journal of Banking and Finance that's +actually a finance journal. Uh where he + + align:start position:0% +actually a finance journal. Uh where he + + + align:start position:0% +actually a finance journal. Uh where he +explained why it wasn't necessarily such + + align:start position:0% +explained why it wasn't necessarily such + + + align:start position:0% +explained why it wasn't necessarily such +a good idea to hold this portfolio. + + align:start position:0% +a good idea to hold this portfolio. + + + align:start position:0% +a good idea to hold this portfolio. +And in this article, every word he used + + align:start position:0% +And in this article, every word he used + + + align:start position:0% +And in this article, every word he used +was of one syllable except the very last + + align:start position:0% +was of one syllable except the very last + + + align:start position:0% +was of one syllable except the very last +word of the article where he managed to + + align:start position:0% +word of the article where he managed to + + + align:start position:0% +word of the article where he managed to +say that he has + + align:start position:0% + + + + align:start position:0% + +okay I can't even do it in one syllable + + align:start position:0% +okay I can't even do it in one syllable + + + align:start position:0% +okay I can't even do it in one syllable +anyway uh he has okay so just ignore my + + align:start position:0% +anyway uh he has okay so just ignore my + + + align:start position:0% +anyway uh he has okay so just ignore my +multi-elabic words but anyway he says uh + + align:start position:0% +multi-elabic words but anyway he says uh + + + align:start position:0% +multi-elabic words but anyway he says uh +I have managed to write a uh article + + align:start position:0% +I have managed to write a uh article + + + align:start position:0% +I have managed to write a uh article +that ends with all words with just one + + align:start position:0% +that ends with all words with just one + + + align:start position:0% +that ends with all words with just one +syllable except for the + + align:start position:0% +syllable except for the + + + align:start position:0% +syllable except for the +okay except for the this last + + align:start position:0% +okay except for the this last + + + align:start position:0% +okay except for the this last +syllable or something like that. Okay, I + + align:start position:0% +syllable or something like that. Okay, I + + + align:start position:0% +syllable or something like that. Okay, I +lost it. Sorry. But anyway, the last + + align:start position:0% +lost it. Sorry. But anyway, the last + + + align:start position:0% +lost it. Sorry. But anyway, the last +word in this thing was syllable itself, + + align:start position:0% +word in this thing was syllable itself, + + + align:start position:0% +word in this thing was syllable itself, +which is multi-elabic or whatever. So, + + align:start position:0% +which is multi-elabic or whatever. So, + + + align:start position:0% +which is multi-elabic or whatever. So, +uh, okay. So, anyway, it was kind of + + align:start position:0% +uh, okay. So, anyway, it was kind of + + + align:start position:0% +uh, okay. So, anyway, it was kind of +insane. So, so let's move on. So, this + + align:start position:0% +insane. So, so let's move on. So, this + + + align:start position:0% +insane. So, so let's move on. So, this +talk, it has six parts and uh we have an + + align:start position:0% +talk, it has six parts and uh we have an + + + align:start position:0% +talk, it has six parts and uh we have an +hour to go. So, let's say we'll try to + + align:start position:0% +hour to go. So, let's say we'll try to + + + align:start position:0% +hour to go. So, let's say we'll try to +spend 10 minutes on each. Yeah. + + align:start position:0% + + + + align:start position:0% + +Well, that's a good question. So, it + + align:start position:0% +Well, that's a good question. So, it + + + align:start position:0% +Well, that's a good question. So, it +does have risk first of all. It does + + align:start position:0% +does have risk first of all. It does + + + align:start position:0% +does have risk first of all. It does +have a lot of risk. Um, let's say um + + align:start position:0% +have a lot of risk. Um, let's say um + + + align:start position:0% +have a lot of risk. Um, let's say um +it's not the riskiest though. Uh so, um + + align:start position:0% +it's not the riskiest though. Uh so, um + + + align:start position:0% +it's not the riskiest though. Uh so, um +some risk does not carry with it + + align:start position:0% +some risk does not carry with it + + + align:start position:0% +some risk does not carry with it +expected return. Uh, and so that's why + + align:start position:0% +expected return. Uh, and so that's why + + + align:start position:0% +expected return. Uh, and so that's why +um it's not the riskiest, but it's + + align:start position:0% +um it's not the riskiest, but it's + + + align:start position:0% +um it's not the riskiest, but it's +risky. So, so Samuelson's objections + + align:start position:0% +risky. So, so Samuelson's objections + + + align:start position:0% +risky. So, so Samuelson's objections +were precisely what you're getting at + + align:start position:0% +were precisely what you're getting at + + + align:start position:0% +were precisely what you're getting at +that this is a fairly risky strategy and + + align:start position:0% +that this is a fairly risky strategy and + + + align:start position:0% +that this is a fairly risky strategy and +uh so it's I'm glad you brought that up. + + align:start position:0% +uh so it's I'm glad you brought that up. + + + align:start position:0% +uh so it's I'm glad you brought that up. +Okay. + + align:start position:0% + + + + align:start position:0% + +Okay. So, there's six parts of the talk. + + align:start position:0% +Okay. So, there's six parts of the talk. + + + align:start position:0% +Okay. So, there's six parts of the talk. +I'm going to go over what aerody + + align:start position:0% +I'm going to go over what aerody + + + align:start position:0% +I'm going to go over what aerody +security prices are. So again they're + + align:start position:0% +security prices are. So again they're + + + align:start position:0% +security prices are. So again they're +digital options prices and uh their + + align:start position:0% +digital options prices and uh their + + + align:start position:0% +digital options prices and uh their +connection to market beliefs. Uh I'll + + align:start position:0% +connection to market beliefs. Uh I'll + + + align:start position:0% +connection to market beliefs. Uh I'll +talk about this Ross recovery theorem. + + align:start position:0% +talk about this Ross recovery theorem. + + + align:start position:0% +talk about this Ross recovery theorem. +So when in Ross' paper which you can get + + align:start position:0% +So when in Ross' paper which you can get + + + align:start position:0% +So when in Ross' paper which you can get +on SSRN + + align:start position:0% +on SSRN + + + align:start position:0% +on SSRN +uh he does everything in a setting + + align:start position:0% +uh he does everything in a setting + + + align:start position:0% +uh he does everything in a setting +that's um that's called finite state + + align:start position:0% +that's um that's called finite state + + + align:start position:0% +that's um that's called finite state +markup chains. And so that's + + align:start position:0% +markup chains. And so that's + + + align:start position:0% +markup chains. And so that's +mathematically simpler than um what we + + align:start position:0% +mathematically simpler than um what we + + + align:start position:0% +mathematically simpler than um what we +use in practice. And um you know I + + align:start position:0% +use in practice. And um you know I + + + align:start position:0% +use in practice. And um you know I +totally agree that when you try to + + align:start position:0% +totally agree that when you try to + + + align:start position:0% +totally agree that when you try to +introduce something you do it in the + + align:start position:0% +introduce something you do it in the + + + align:start position:0% +introduce something you do it in the +simplest mathematical setting. So now + + align:start position:0% +simplest mathematical setting. So now + + + align:start position:0% +simplest mathematical setting. So now +that he's done that I wanted to do it in + + align:start position:0% +that he's done that I wanted to do it in + + + align:start position:0% +that he's done that I wanted to do it in +a more familiar setting uh which is a + + align:start position:0% +a more familiar setting uh which is a + + + align:start position:0% +a more familiar setting uh which is a +diffusion setting. Okay. So that's that + + align:start position:0% +diffusion setting. Okay. So that's that + + + align:start position:0% +diffusion setting. Okay. So that's that +a diffusion has an uncountably infinite + + align:start position:0% +a diffusion has an uncountably infinite + + + align:start position:0% +a diffusion has an uncountably infinite +number of states and I still want to + + align:start position:0% +number of states and I still want to + + + align:start position:0% +number of states and I still want to +keep things as simple as possible while + + align:start position:0% +keep things as simple as possible while + + + align:start position:0% +keep things as simple as possible while +going beyond finite state mark of + + align:start position:0% +going beyond finite state mark of + + + align:start position:0% +going beyond finite state mark of +change. So I work in a univariate + + align:start position:0% +change. So I work in a univariate + + + align:start position:0% +change. So I work in a univariate +diffusion setting. So there's only one + + align:start position:0% +diffusion setting. So there's only one + + + align:start position:0% +diffusion setting. So there's only one +source of uncertainty which is the same + + align:start position:0% +source of uncertainty which is the same + + + align:start position:0% +source of uncertainty which is the same +as in Ross. And um + + align:start position:0% +as in Ross. And um + + + align:start position:0% +as in Ross. And um +uh our technique is um to get these + + align:start position:0% +uh our technique is um to get these + + + align:start position:0% +uh our technique is um to get these +results is based on something called + + align:start position:0% +results is based on something called + + + align:start position:0% +results is based on something called +change of numer. So a numer is a + + align:start position:0% +change of numer. So a numer is a + + + align:start position:0% +change of numer. So a numer is a +technical term actually that describes + + align:start position:0% +technical term actually that describes + + + align:start position:0% +technical term actually that describes +an asset whose value is always positive. + + align:start position:0% +an asset whose value is always positive. + + + align:start position:0% +an asset whose value is always positive. +So um there are securities whose values + + align:start position:0% +So um there are securities whose values + + + align:start position:0% +So um there are securities whose values +can have either sign. So swaps are a + + align:start position:0% +can have either sign. So swaps are a + + + align:start position:0% +can have either sign. So swaps are a +classical example. So a swap is a + + align:start position:0% +classical example. So a swap is a + + + align:start position:0% +classical example. So a swap is a +security which at inception has zero + + align:start position:0% +security which at inception has zero + + + align:start position:0% +security which at inception has zero +value actually and then the moment after + + align:start position:0% +value actually and then the moment after + + + align:start position:0% +value actually and then the moment after +inception the world changes and the swap + + align:start position:0% +inception the world changes and the swap + + + align:start position:0% +inception the world changes and the swap +value either becomes positive or becomes + + align:start position:0% +value either becomes positive or becomes + + + align:start position:0% +value either becomes positive or becomes +negative and um so so a swap would not + + align:start position:0% +negative and um so so a swap would not + + + align:start position:0% +negative and um so so a swap would not +be eligible to be a numerator because of + + align:start position:0% +be eligible to be a numerator because of + + + align:start position:0% +be eligible to be a numerator because of +that property that its value is real. Uh + + align:start position:0% +that property that its value is real. Uh + + + align:start position:0% +that property that its value is real. Uh +on the other hand, if you take a stock, + + align:start position:0% +on the other hand, if you take a stock, + + + align:start position:0% +on the other hand, if you take a stock, +its price is always positive. Um well, + + align:start position:0% +its price is always positive. Um well, + + + align:start position:0% +its price is always positive. Um well, +that's debatable. So actually, so let's + + align:start position:0% +that's debatable. So actually, so let's + + + align:start position:0% +that's debatable. So actually, so let's +say um so let's say um let's not do a + + align:start position:0% +say um so let's say um let's not do a + + + align:start position:0% +say um so let's say um let's not do a +stock. Let's do a treasury bond. A + + align:start position:0% +stock. Let's do a treasury bond. A + + + align:start position:0% +stock. Let's do a treasury bond. A +treasury bond uh US Treasury bond, its + + align:start position:0% +treasury bond uh US Treasury bond, its + + + align:start position:0% +treasury bond uh US Treasury bond, its +price is always positive. Um the the + + align:start position:0% +price is always positive. Um the the + + + align:start position:0% +price is always positive. Um the the +reason I want to shy away from stocks is + + align:start position:0% +reason I want to shy away from stocks is + + + align:start position:0% +reason I want to shy away from stocks is +because if you take Lehman Brothers + + align:start position:0% +because if you take Lehman Brothers + + + align:start position:0% +because if you take Lehman Brothers +stock for example, its price was + + align:start position:0% +stock for example, its price was + + + align:start position:0% +stock for example, its price was +positive then became zero. And actually + + align:start position:0% +positive then became zero. And actually + + + align:start position:0% +positive then became zero. And actually +because Lehman's price became zero, + + align:start position:0% +because Lehman's price became zero, + + + align:start position:0% +because Lehman's price became zero, +Leman's share could not be a numerator. + + align:start position:0% +Leman's share could not be a numerator. + + + align:start position:0% +Leman's share could not be a numerator. +So when I say that the numer value has + + align:start position:0% +So when I say that the numer value has + + + align:start position:0% +So when I say that the numer value has +to be positive, I mean strictly + + align:start position:0% +to be positive, I mean strictly + + + align:start position:0% +to be positive, I mean strictly +positive. Okay. And um so um so anyway + + align:start position:0% +positive. Okay. And um so um so anyway + + + align:start position:0% +positive. Okay. And um so um so anyway +there's this literature about how to + + align:start position:0% +there's this literature about how to + + + align:start position:0% +there's this literature about how to +change numerators, how to go from one + + align:start position:0% +change numerators, how to go from one + + + align:start position:0% +change numerators, how to go from one +asset with positive value to another + + align:start position:0% +asset with positive value to another + + + align:start position:0% +asset with positive value to another +asset with positive value and um it's uh + + align:start position:0% +asset with positive value and um it's uh + + + align:start position:0% +asset with positive value and um it's uh +useful for understanding how this ROS + + align:start position:0% +useful for understanding how this ROS + + + align:start position:0% +useful for understanding how this ROS +recovery works. So um we apply it uh + + align:start position:0% +recovery works. So um we apply it uh + + + align:start position:0% +recovery works. So um we apply it uh +when we have uh a so-called time + + align:start position:0% +when we have uh a so-called time + + + align:start position:0% +when we have uh a so-called time +homogeneous diffusion. I'll tell you + + align:start position:0% +homogeneous diffusion. I'll tell you + + + align:start position:0% +homogeneous diffusion. I'll tell you +what that means uh over a bounded state + + align:start position:0% +what that means uh over a bounded state + + + align:start position:0% +what that means uh over a bounded state +space. So bounded state space means that + + align:start position:0% +space. So bounded state space means that + + + align:start position:0% +space. So bounded state space means that +the set of values that the diffusion can + + align:start position:0% +the set of values that the diffusion can + + + align:start position:0% +the set of values that the diffusion can +take is in some finite interval. So um + + align:start position:0% +take is in some finite interval. So um + + + align:start position:0% +take is in some finite interval. So um +so if you're thinking about the + + align:start position:0% +so if you're thinking about the + + + align:start position:0% +so if you're thinking about the +uncertainty being for example S&P 500 + + align:start position:0% +uncertainty being for example S&P 500 + + + align:start position:0% +uncertainty being for example S&P 500 +then the natural lower bound for S&P 500 + + align:start position:0% +then the natural lower bound for S&P 500 + + + align:start position:0% +then the natural lower bound for S&P 500 +would be zero + + align:start position:0% +would be zero + + + align:start position:0% +would be zero +and you have to accept that there's a + + align:start position:0% +and you have to accept that there's a + + + align:start position:0% +and you have to accept that there's a +finite upper bound in order to apply our + + align:start position:0% +finite upper bound in order to apply our + + + align:start position:0% +finite upper bound in order to apply our +results. Now, you know, personally, I + + align:start position:0% +results. Now, you know, personally, I + + + align:start position:0% +results. Now, you know, personally, I +have no problem saying that S&P 500 is + + align:start position:0% +have no problem saying that S&P 500 is + + + align:start position:0% +have no problem saying that S&P 500 is +bounded above by 20 trillion. Okay? But, + + align:start position:0% +bounded above by 20 trillion. Okay? But, + + + align:start position:0% +bounded above by 20 trillion. Okay? But, +um, some economists have actually said, + + align:start position:0% +um, some economists have actually said, + + + align:start position:0% +um, some economists have actually said, +uh, this is ridiculous uh, you know, and + + align:start position:0% +uh, this is ridiculous uh, you know, and + + + align:start position:0% +uh, this is ridiculous uh, you know, and +challenged my work and stuff like that + + align:start position:0% +challenged my work and stuff like that + + + align:start position:0% +challenged my work and stuff like that +for for for that assumption. So, so + + align:start position:0% +for for for that assumption. So, so + + + align:start position:0% +for for for that assumption. So, so +anyway, so because of those challenges, + + align:start position:0% +anyway, so because of those challenges, + + + align:start position:0% +anyway, so because of those challenges, +I have actually been uh trying to extend + + align:start position:0% +I have actually been uh trying to extend + + + align:start position:0% +I have actually been uh trying to extend +our work to an unbounded state space + + align:start position:0% +our work to an unbounded state space + + + align:start position:0% +our work to an unbounded state space +where the you know, let's say the + + align:start position:0% +where the you know, let's say the + + + align:start position:0% +where the you know, let's say the +largest possible value for S&P 500 would + + align:start position:0% +largest possible value for S&P 500 would + + + align:start position:0% +largest possible value for S&P 500 would +be infinity. And um I found actually + + align:start position:0% +be infinity. And um I found actually + + + align:start position:0% +be infinity. And um I found actually +that it's not that easy. And so um so + + align:start position:0% +that it's not that easy. And so um so + + + align:start position:0% +that it's not that easy. And so um so +sometimes I can make it work and + + align:start position:0% +sometimes I can make it work and + + + align:start position:0% +sometimes I can make it work and +sometimes I cannot. So I'll when we get + + align:start position:0% +sometimes I cannot. So I'll when we get + + + align:start position:0% +sometimes I cannot. So I'll when we get +there I'll explain some examples that + + align:start position:0% +there I'll explain some examples that + + + align:start position:0% +there I'll explain some examples that +work and some examples that don't. So + + align:start position:0% +work and some examples that don't. So + + + align:start position:0% +work and some examples that don't. So +this this last section is kind of + + align:start position:0% +this this last section is kind of + + + align:start position:0% +this this last section is kind of +incomplete the sixth section. And so + + align:start position:0% +incomplete the sixth section. And so + + + align:start position:0% +incomplete the sixth section. And so +basically I've got examples that fail, + + align:start position:0% +basically I've got examples that fail, + + + align:start position:0% +basically I've got examples that fail, +examples that succeed, but I don't have + + align:start position:0% +examples that succeed, but I don't have + + + align:start position:0% +examples that succeed, but I don't have +a general theory. + + align:start position:0% +a general theory. + + + align:start position:0% +a general theory. +So um there'll be different assumptions + + align:start position:0% +So um there'll be different assumptions + + + align:start position:0% +So um there'll be different assumptions +in different parts of the talk, but + + align:start position:0% +in different parts of the talk, but + + + align:start position:0% +in different parts of the talk, but +within a section there's only one set of + + align:start position:0% +within a section there's only one set of + + + align:start position:0% +within a section there's only one set of +assumptions operating. + + align:start position:0% +assumptions operating. + + + align:start position:0% +assumptions operating. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +So we say that the value of anything is + + align:start position:0% +So we say that the value of anything is + + + align:start position:0% +So we say that the value of anything is +always bounded by by the fact that the + + align:start position:0% +always bounded by by the fact that the + + + align:start position:0% +always bounded by by the fact that the +universe I know you're going to say + + align:start position:0% +universe I know you're going to say + + + align:start position:0% +universe I know you're going to say +that. So that's been my response too. + + align:start position:0% +that. So that's been my response too. + + + align:start position:0% +that. So that's been my response too. +So, uh, the universe is bounded and it's + + align:start position:0% +So, uh, the universe is bounded and it's + + + align:start position:0% +So, uh, the universe is bounded and it's +growing that it's bounded. So, um, so, + + align:start position:0% +growing that it's bounded. So, um, so, + + + align:start position:0% +growing that it's bounded. So, um, so, +uh, so, so I agree. I mean, you know, so + + align:start position:0% +uh, so, so I agree. I mean, you know, so + + + align:start position:0% +uh, so, so I agree. I mean, you know, so +I'm on your side on this. I'm just + + align:start position:0% +I'm on your side on this. I'm just + + + align:start position:0% +I'm on your side on this. I'm just +telling you what I've been told. Uh, + + align:start position:0% +telling you what I've been told. Uh, + + + align:start position:0% +telling you what I've been told. Uh, +yeah. So, I'm working on it anyway just + + align:start position:0% +yeah. So, I'm working on it anyway just + + + align:start position:0% +yeah. So, I'm working on it anyway just +so I can shut up. But, uh, anyway, + + align:start position:0% +so I can shut up. But, uh, anyway, + + + align:start position:0% +so I can shut up. But, uh, anyway, +actually, I have some comments. Yeah. + + align:start position:0% +actually, I have some comments. Yeah. + + + align:start position:0% +actually, I have some comments. Yeah. +The issue of the numer + + align:start position:0% +The issue of the numer + + + align:start position:0% +The issue of the numer +tell me how connected this is, but with, + + align:start position:0% +tell me how connected this is, but with, + + + align:start position:0% +tell me how connected this is, but with, +uh, the Kelly criterion. um you know the + + align:start position:0% +uh, the Kelly criterion. um you know the + + + align:start position:0% +uh, the Kelly criterion. um you know the +or one of the origins of that is if + + align:start position:0% +or one of the origins of that is if + + + align:start position:0% +or one of the origins of that is if +you're going to if you have a a gambling + + align:start position:0% +you're going to if you have a a gambling + + + align:start position:0% +you're going to if you have a a gambling +opportunity where where it's favorable + + align:start position:0% +opportunity where where it's favorable + + + align:start position:0% +opportunity where where it's favorable +how much of your bankroll should you bet + + align:start position:0% +how much of your bankroll should you bet + + + align:start position:0% +how much of your bankroll should you bet +on that gamble and um the uh basically + + align:start position:0% +on that gamble and um the uh basically + + + align:start position:0% +on that gamble and um the uh basically +the Kelly criterion tells you what + + align:start position:0% +the Kelly criterion tells you what + + + align:start position:0% +the Kelly criterion tells you what +proportion of your bankroll you should + + align:start position:0% +proportion of your bankroll you should + + + align:start position:0% +proportion of your bankroll you should +invest at all times you should never bet + + align:start position:0% +invest at all times you should never bet + + + align:start position:0% +invest at all times you should never bet +everything and if you do bet everything + + align:start position:0% +everything and if you do bet everything + + + align:start position:0% +everything and if you do bet everything +you lose everything and you're done so + + align:start position:0% +you lose everything and you're done so + + + align:start position:0% +you lose everything and you're done so +yeah so so um the issue with the numer + + align:start position:0% +yeah so so um the issue with the numer + + + align:start position:0% +yeah so so um the issue with the numer +portfolio and or never being able to go + + align:start position:0% +portfolio and or never being able to go + + + align:start position:0% +portfolio and or never being able to go +down to zero in the sense that yeah, you + + align:start position:0% +down to zero in the sense that yeah, you + + + align:start position:0% +down to zero in the sense that yeah, you +can never go bankrupt and that's true + + align:start position:0% +can never go bankrupt and that's true + + + align:start position:0% +can never go bankrupt and that's true +and and so uh assumptions that of uh you + + align:start position:0% +and and so uh assumptions that of uh you + + + align:start position:0% +and and so uh assumptions that of uh you +know being able to always rebalance your + + align:start position:0% +know being able to always rebalance your + + + align:start position:0% +know being able to always rebalance your +portfolio. Yeah. So this just give you a + + align:start position:0% +portfolio. Yeah. So this just give you a + + + align:start position:0% +portfolio. Yeah. So this just give you a +flavor of what this numeric portfolio + + align:start position:0% +flavor of what this numeric portfolio + + + align:start position:0% +flavor of what this numeric portfolio +is. It's uh you have um you you're + + align:start position:0% +is. It's uh you have um you you're + + + align:start position:0% +is. It's uh you have um you you're +betting a constant fraction of your + + align:start position:0% +betting a constant fraction of your + + + align:start position:0% +betting a constant fraction of your +wealth in every security. So um so so + + align:start position:0% +wealth in every security. So um so so + + + align:start position:0% +wealth in every security. So um so so +let's just keep it simple. There's + + align:start position:0% +let's just keep it simple. There's + + + align:start position:0% +let's just keep it simple. There's +there's only two securities. Uh one is + + align:start position:0% +there's only two securities. Uh one is + + + align:start position:0% +there's only two securities. Uh one is +risky and the other is riskless. And um + + align:start position:0% +risky and the other is riskless. And um + + + align:start position:0% +risky and the other is riskless. And um +so you might be betting putting 40% of + + align:start position:0% +so you might be betting putting 40% of + + + align:start position:0% +so you might be betting putting 40% of +your wealth in the risky one and 60% + + align:start position:0% +your wealth in the risky one and 60% + + + align:start position:0% +your wealth in the risky one and 60% +then in the riskless one. And um that's + + align:start position:0% +then in the riskless one. And um that's + + + align:start position:0% +then in the riskless one. And um that's +when you start. So you have $100 and you + + align:start position:0% +when you start. So you have $100 and you + + + align:start position:0% +when you start. So you have $100 and you +put 40 in the risky one and 60 in the + + align:start position:0% +put 40 in the risky one and 60 in the + + + align:start position:0% +put 40 in the risky one and 60 in the +riskless one. And um then time moves + + align:start position:0% +riskless one. And um then time moves + + + align:start position:0% +riskless one. And um then time moves +forward + + align:start position:0% +forward + + + align:start position:0% +forward +and let's say the price of the risky one + + align:start position:0% +and let's say the price of the risky one + + + align:start position:0% +and let's say the price of the risky one +changes. + + align:start position:0% +changes. + + + align:start position:0% +changes. +Then um when you revalue using the new + + align:start position:0% +Then um when you revalue using the new + + + align:start position:0% +Then um when you revalue using the new +price, it's unlikely that 40% of your + + align:start position:0% +price, it's unlikely that 40% of your + + + align:start position:0% +price, it's unlikely that 40% of your +wealth is in the risky one. So um so in + + align:start position:0% +wealth is in the risky one. So um so in + + + align:start position:0% +wealth is in the risky one. So um so in +fact, if the price went up of the risky + + align:start position:0% +fact, if the price went up of the risky + + + align:start position:0% +fact, if the price went up of the risky +one, you'll have more than 40% of your + + align:start position:0% +one, you'll have more than 40% of your + + + align:start position:0% +one, you'll have more than 40% of your +wealth in that risky one. So you need to + + align:start position:0% +wealth in that risky one. So you need to + + + align:start position:0% +wealth in that risky one. So you need to +sell some of that risky one. And then + + align:start position:0% +sell some of that risky one. And then + + + align:start position:0% +sell some of that risky one. And then +the money you get, you put into the + + align:start position:0% +the money you get, you put into the + + + align:start position:0% +the money you get, you put into the +riskless one. And um and then so that's + + align:start position:0% +riskless one. And um and then so that's + + + align:start position:0% +riskless one. And um and then so that's +and so every time the price changes you + + align:start position:0% +and so every time the price changes you + + + align:start position:0% +and so every time the price changes you +need to trade theoretically in order to + + align:start position:0% +need to trade theoretically in order to + + + align:start position:0% +need to trade theoretically in order to +maintain + + align:start position:0% +maintain + + + align:start position:0% +maintain +a constant fraction of 40% of your + + align:start position:0% +a constant fraction of 40% of your + + + align:start position:0% +a constant fraction of 40% of your +wealth invested in this risky asset. So + + align:start position:0% +wealth invested in this risky asset. So + + + align:start position:0% +wealth invested in this risky asset. So +um so it's uh so we assume zero + + align:start position:0% +um so it's uh so we assume zero + + + align:start position:0% +um so it's uh so we assume zero +transactions costs when we do this + + align:start position:0% +transactions costs when we do this + + + align:start position:0% +transactions costs when we do this +analysis. So because there are positive + + align:start position:0% +analysis. So because there are positive + + + align:start position:0% +analysis. So because there are positive +transactions costs one you know one + + align:start position:0% +transactions costs one you know one + + + align:start position:0% +transactions costs one you know one +should take that into account and there + + align:start position:0% +should take that into account and there + + + align:start position:0% +should take that into account and there +is literature on how to do that. + + align:start position:0% +is literature on how to do that. + + + align:start position:0% +is literature on how to do that. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +so I won't be formally entertaining + + align:start position:0% +so I won't be formally entertaining + + + align:start position:0% +so I won't be formally entertaining +transactions cost in this talk. Uh it's + + align:start position:0% +transactions cost in this talk. Uh it's + + + align:start position:0% +transactions cost in this talk. Uh it's +um there's work here at MIT actually on + + align:start position:0% +um there's work here at MIT actually on + + + align:start position:0% +um there's work here at MIT actually on +doing that. Uh and um + + align:start position:0% +doing that. Uh and um + + + align:start position:0% +doing that. Uh and um +it's hard to like for the question of + + align:start position:0% +it's hard to like for the question of + + + align:start position:0% +it's hard to like for the question of +how should you invest + + align:start position:0% +how should you invest + + + align:start position:0% +how should you invest +it feels like it's a complication + + align:start position:0% +it feels like it's a complication + + + align:start position:0% +it feels like it's a complication +that won't change anything qualitative + + align:start position:0% +that won't change anything qualitative + + + align:start position:0% +that won't change anything qualitative +about it might change how frequently it + + align:start position:0% +about it might change how frequently it + + + align:start position:0% +about it might change how frequently it +definitely change how frequently you + + align:start position:0% +definitely change how frequently you + + + align:start position:0% +definitely change how frequently you +trade but it wouldn't um let's say it's + + align:start position:0% +trade but it wouldn't um let's say it's + + + align:start position:0% +trade but it wouldn't um let's say it's +unclear how it would change your initial + + align:start position:0% +unclear how it would change your initial + + + align:start position:0% +unclear how it would change your initial +investment across across bets. + + align:start position:0% + + + + align:start position:0% + +So let's begin with part one. So we have + + align:start position:0% +So let's begin with part one. So we have + + + align:start position:0% +So let's begin with part one. So we have +these digital options or also called + + align:start position:0% +these digital options or also called + + + align:start position:0% +these digital options or also called +binary options. That's another term. And + + align:start position:0% +binary options. That's another term. And + + + align:start position:0% +binary options. That's another term. And +um + + align:start position:0% +um + + + align:start position:0% +um +they trade actually in FX markets. So + + align:start position:0% +they trade actually in FX markets. So + + + align:start position:0% +they trade actually in FX markets. So +foreign exchange and um they pay one + + align:start position:0% +foreign exchange and um they pay one + + + align:start position:0% +foreign exchange and um they pay one +unit of some currency. So say dollar if + + align:start position:0% +unit of some currency. So say dollar if + + + align:start position:0% +unit of some currency. So say dollar if +um an event comes true. + + align:start position:0% +um an event comes true. + + + align:start position:0% +um an event comes true. +So it might be that you're looking at + + align:start position:0% +So it might be that you're looking at + + + align:start position:0% +So it might be that you're looking at +dollar euro and um if by the end of the + + align:start position:0% +dollar euro and um if by the end of the + + + align:start position:0% +dollar euro and um if by the end of the +year dollar euro exceeds two uh then you + + align:start position:0% +year dollar euro exceeds two uh then you + + + align:start position:0% +year dollar euro exceeds two uh then you +get a dollar otherwise you get zero and + + align:start position:0% +get a dollar otherwise you get zero and + + + align:start position:0% +get a dollar otherwise you get zero and +um + + align:start position:0% +um + + + align:start position:0% +um +so there would be a price in the FX + + align:start position:0% +so there would be a price in the FX + + + align:start position:0% +so there would be a price in the FX +markets and it would be a spot price + + align:start position:0% +markets and it would be a spot price + + + align:start position:0% +markets and it would be a spot price +typically so meaning you have to pay now + + align:start position:0% +typically so meaning you have to pay now + + + align:start position:0% +typically so meaning you have to pay now +for it. Um the uh let's uh let a for + + align:start position:0% +for it. Um the uh let's uh let a for + + + align:start position:0% +for it. Um the uh let's uh let a for +arrow be the price today uh of such a + + align:start position:0% +arrow be the price today uh of such a + + + align:start position:0% +arrow be the price today uh of such a +security and the subscripts on a or j + + align:start position:0% +security and the subscripts on a or j + + + align:start position:0% +security and the subscripts on a or j +given i. So the uh idea is that you can + + align:start position:0% +given i. So the uh idea is that you can + + + align:start position:0% +given i. So the uh idea is that you can +think of yourself as in a finite state + + align:start position:0% +think of yourself as in a finite state + + + align:start position:0% +think of yourself as in a finite state +setting. There's various discreet levels + + align:start position:0% +setting. There's various discreet levels + + + align:start position:0% +setting. There's various discreet levels +of say dollar euro that we have that can + + align:start position:0% +of say dollar euro that we have that can + + + align:start position:0% +of say dollar euro that we have that can +be possible today and there's also + + align:start position:0% +be possible today and there's also + + + align:start position:0% +be possible today and there's also +various discrete levels for dollar euro + + align:start position:0% +various discrete levels for dollar euro + + + align:start position:0% +various discrete levels for dollar euro +by the end of the year and um I + + align:start position:0% +by the end of the year and um I + + + align:start position:0% +by the end of the year and um I +indicates the state we're in. So maybe + + align:start position:0% +indicates the state we're in. So maybe + + + align:start position:0% +indicates the state we're in. So maybe +dollar euro is $2 per euro right now. + + align:start position:0% +dollar euro is $2 per euro right now. + + + align:start position:0% +dollar euro is $2 per euro right now. +And um and uh J indicates the state we + + align:start position:0% +And um and uh J indicates the state we + + + align:start position:0% +And um and uh J indicates the state we +can go to. Maybe we can go to $3 per + + align:start position:0% +can go to. Maybe we can go to $3 per + + + align:start position:0% +can go to. Maybe we can go to $3 per +euro. Okay. So + + align:start position:0% +euro. Okay. So + + + align:start position:0% +euro. Okay. So +um + + align:start position:0% +um + + + align:start position:0% +um +and um so so in my example A32 would be + + align:start position:0% +and um so so in my example A32 would be + + + align:start position:0% +and um so so in my example A32 would be +the price of an air debris security + + align:start position:0% +the price of an air debris security + + + align:start position:0% +the price of an air debris security +given that the current dollar euro + + align:start position:0% +given that the current dollar euro + + + align:start position:0% +given that the current dollar euro +exchange rate is $2 per euro and it pays + + align:start position:0% +exchange rate is $2 per euro and it pays + + + align:start position:0% +exchange rate is $2 per euro and it pays +$1 just if dollar euro transitions from + + align:start position:0% +$1 just if dollar euro transitions from + + + align:start position:0% +$1 just if dollar euro transitions from +$2 per euro to $3 per euro. + + align:start position:0% + + + + align:start position:0% + +So um now you can use either um these + + align:start position:0% + + + + align:start position:0% + +so the + + align:start position:0% +so the + + + align:start position:0% +so the +idea is we have discrete states and + + align:start position:0% +idea is we have discrete states and + + + align:start position:0% +idea is we have discrete states and +let's say these are values that are + + align:start position:0% +let's say these are values that are + + + align:start position:0% +let's say these are values that are +possible at the end of the year + + align:start position:0% +possible at the end of the year + + + align:start position:0% +possible at the end of the year +and the example I just went through + + align:start position:0% +and the example I just went through + + + align:start position:0% +and the example I just went through +you're getting $1 just if + + align:start position:0% +you're getting $1 just if + + + align:start position:0% +you're getting $1 just if +it's $3 per euro at the end of the year + + align:start position:0% +it's $3 per euro at the end of the year + + + align:start position:0% +it's $3 per euro at the end of the year +and um so the height height of that + + align:start position:0% +and um so the height height of that + + + align:start position:0% +and um so the height height of that +vertical line is one. + + align:start position:0% + + + + align:start position:0% + +And um + + align:start position:0% +And um + + + align:start position:0% +And um +now I'll just comment that + + align:start position:0% +now I'll just comment that + + + align:start position:0% +now I'll just comment that +um + + align:start position:0% +um + + + align:start position:0% +um +this is a slightly exotic option in the + + align:start position:0% +this is a slightly exotic option in the + + + align:start position:0% +this is a slightly exotic option in the +sense that um it's called exotic. It's + + align:start position:0% +sense that um it's called exotic. It's + + + align:start position:0% +sense that um it's called exotic. It's +slightly exotic. Um so contra in + + align:start position:0% +slightly exotic. Um so contra in + + + align:start position:0% +slightly exotic. Um so contra in +contrast with exotics there's this term + + align:start position:0% +contrast with exotics there's this term + + + align:start position:0% +contrast with exotics there's this term +vanilla. Okay. and it actually indicates + + align:start position:0% +vanilla. Okay. and it actually indicates + + + align:start position:0% +vanilla. Okay. and it actually indicates +a flavor of ice cream. And uh so um so + + align:start position:0% +a flavor of ice cream. And uh so um so + + + align:start position:0% +a flavor of ice cream. And uh so um so +we have this terminology which you get + + align:start position:0% +we have this terminology which you get + + + align:start position:0% +we have this terminology which you get +used to after a while and you can't + + align:start position:0% +used to after a while and you can't + + + align:start position:0% +used to after a while and you can't +understand when you talk to a man on the + + align:start position:0% +understand when you talk to a man on the + + + align:start position:0% +understand when you talk to a man on the +street why they don't understand what a + + align:start position:0% +street why they don't understand what a + + + align:start position:0% +street why they don't understand what a +vanilla option is. So anyway, so a + + align:start position:0% +vanilla option is. So anyway, so a + + + align:start position:0% +vanilla option is. So anyway, so a +vanilla option is a payoff that um looks + + align:start position:0% +vanilla option is a payoff that um looks + + + align:start position:0% +vanilla option is a payoff that um looks +like + + align:start position:0% +like + + + align:start position:0% +like +like this. Okay, so it's a hockey stick + + align:start position:0% +like this. Okay, so it's a hockey stick + + + align:start position:0% +like this. Okay, so it's a hockey stick +payoff. Okay, and uh that's that's the + + align:start position:0% +payoff. Okay, and uh that's that's the + + + align:start position:0% +payoff. Okay, and uh that's that's the +payoff from a call option. And um it + + align:start position:0% +payoff from a call option. And um it + + + align:start position:0% +payoff from a call option. And um it +turns out that there is a pay there is a + + align:start position:0% +turns out that there is a pay there is a + + + align:start position:0% +turns out that there is a pay there is a +portfolio involving + + align:start position:0% +portfolio involving + + + align:start position:0% +portfolio involving +options at three different strikes that + + align:start position:0% +options at three different strikes that + + + align:start position:0% +options at three different strikes that +can perfectly replicate the payoff to + + align:start position:0% +can perfectly replicate the payoff to + + + align:start position:0% +can perfectly replicate the payoff to +this aerodyru security. And so here's a + + align:start position:0% +this aerodyru security. And so here's a + + + align:start position:0% +this aerodyru security. And so here's a +payoff from a single option struck at + + align:start position:0% +payoff from a single option struck at + + + align:start position:0% +payoff from a single option struck at +two. And um I'll just uh say that if I + + align:start position:0% +two. And um I'll just uh say that if I + + + align:start position:0% +two. And um I'll just uh say that if I +had changed the strike to say B3 then it + + align:start position:0% +had changed the strike to say B3 then it + + + align:start position:0% +had changed the strike to say B3 then it +would look like that. Now + + align:start position:0% +would look like that. Now + + + align:start position:0% +would look like that. Now +and and + + align:start position:0% +and and + + + align:start position:0% +and and +so now you can combine options into a + + align:start position:0% +so now you can combine options into a + + + align:start position:0% +so now you can combine options into a +portfolio. So you could for example buy + + align:start position:0% +portfolio. So you could for example buy + + + align:start position:0% +portfolio. So you could for example buy +a call struck at two and then you can + + align:start position:0% +a call struck at two and then you can + + + align:start position:0% +a call struck at two and then you can +furthermore sell two calls struck at + + align:start position:0% +furthermore sell two calls struck at + + + align:start position:0% +furthermore sell two calls struck at +three. So if you sell on top of that two + + align:start position:0% +three. So if you sell on top of that two + + + align:start position:0% +three. So if you sell on top of that two +calls struck at three, you end up + + align:start position:0% +calls struck at three, you end up + + + align:start position:0% +calls struck at three, you end up +creating a portfolio that goes like + + align:start position:0% +creating a portfolio that goes like + + + align:start position:0% +creating a portfolio that goes like +this. Okay? And um + + align:start position:0% +this. Okay? And um + + + align:start position:0% +this. Okay? And um +and so it can go negative in value. + + align:start position:0% +and so it can go negative in value. + + + align:start position:0% +and so it can go negative in value. +So if you not only + + align:start position:0% +So if you not only + + + align:start position:0% +So if you not only +buy one call struck at two, sell two + + align:start position:0% +buy one call struck at two, sell two + + + align:start position:0% +buy one call struck at two, sell two +calls struck at three, but furthermore + + align:start position:0% +calls struck at three, but furthermore + + + align:start position:0% +calls struck at three, but furthermore +buy one call struck at four, then you + + align:start position:0% +buy one call struck at four, then you + + + align:start position:0% +buy one call struck at four, then you +end up with this payoff, which is the + + align:start position:0% +end up with this payoff, which is the + + + align:start position:0% +end up with this payoff, which is the +payoff is called a butterfly spread + + align:start position:0% +payoff is called a butterfly spread + + + align:start position:0% +payoff is called a butterfly spread +payoff because the picture is meant to + + align:start position:0% +payoff because the picture is meant to + + + align:start position:0% +payoff because the picture is meant to +remind you of a butterfly. Okay? And um + + align:start position:0% +remind you of a butterfly. Okay? And um + + + align:start position:0% +remind you of a butterfly. Okay? And um +and notice that if the only possible + + align:start position:0% +and notice that if the only possible + + + align:start position:0% +and notice that if the only possible +values for for the FX rate were $1 per + + align:start position:0% +values for for the FX rate were $1 per + + + align:start position:0% +values for for the FX rate were $1 per +euro, $2 per euro, three or four or five + + align:start position:0% +euro, $2 per euro, three or four or five + + + align:start position:0% +euro, $2 per euro, three or four or five +if that were the world, then um notice + + align:start position:0% +if that were the world, then um notice + + + align:start position:0% +if that were the world, then um notice +that when you form that portfolio, the + + align:start position:0% +that when you form that portfolio, the + + + align:start position:0% +that when you form that portfolio, the +only positive payoff you can get from it + + align:start position:0% +only positive payoff you can get from it + + + align:start position:0% +only positive payoff you can get from it +is $1 just if dollar euro is at three. + + align:start position:0% +is $1 just if dollar euro is at three. + + + align:start position:0% +is $1 just if dollar euro is at three. +Okay? + + align:start position:0% +Okay? + + + align:start position:0% +Okay? +So you can synthesize a butterfly. you + + align:start position:0% +So you can synthesize a butterfly. you + + + align:start position:0% +So you can synthesize a butterfly. you +can synthesize an error to breathe + + align:start position:0% +can synthesize an error to breathe + + + align:start position:0% +can synthesize an error to breathe +security using a butterfly spread. Okay. + + align:start position:0% +security using a butterfly spread. Okay. + + + align:start position:0% +security using a butterfly spread. Okay. +Okay. So this was pointed out many years + + align:start position:0% +Okay. So this was pointed out many years + + + align:start position:0% +Okay. So this was pointed out many years +ago and um so so we really so even if + + align:start position:0% +ago and um so so we really so even if + + + align:start position:0% +ago and um so so we really so even if +the FX market were say not directly + + align:start position:0% +the FX market were say not directly + + + align:start position:0% +the FX market were say not directly +giving us the prices of digital options, + + align:start position:0% +giving us the prices of digital options, + + + align:start position:0% +giving us the prices of digital options, +we could from vanilla options extract + + align:start position:0% +we could from vanilla options extract + + + align:start position:0% +we could from vanilla options extract +the implicit price of a digital and um + + align:start position:0% +the implicit price of a digital and um + + + align:start position:0% +the implicit price of a digital and um +so so + + align:start position:0% +so so + + + align:start position:0% +so so +um + + align:start position:0% +um + + + align:start position:0% +um +and what you would learn from vanilla + + align:start position:0% +and what you would learn from vanilla + + + align:start position:0% +and what you would learn from vanilla +options is you know what the market is + + align:start position:0% +options is you know what the market is + + + align:start position:0% +options is you know what the market is +charging for the digital given that + + align:start position:0% +charging for the digital given that + + + align:start position:0% +charging for the digital given that +let's say we're presently at $2 per euro + + align:start position:0% +let's say we're presently at $2 per euro + + + align:start position:0% +let's say we're presently at $2 per euro +and um what you would not learn from + + align:start position:0% +and um what you would not learn from + + + align:start position:0% +and um what you would not learn from +these options prices is what the price + + align:start position:0% +these options prices is what the price + + + align:start position:0% +these options prices is what the price +of this security will be should we today + + align:start position:0% +of this security will be should we today + + + align:start position:0% +of this security will be should we today +have the exchange rate changed to some + + align:start position:0% +have the exchange rate changed to some + + + align:start position:0% +have the exchange rate changed to some +other value. Okay. So um so but however + + align:start position:0% +other value. Okay. So um so but however + + + align:start position:0% +other value. Okay. So um so but however +you can make assumptions that as to what + + align:start position:0% +you can make assumptions that as to what + + + align:start position:0% +you can make assumptions that as to what +the options prices will be were today's + + align:start position:0% +the options prices will be were today's + + + align:start position:0% +the options prices will be were today's +exchange rate different and um so um so + + align:start position:0% +exchange rate different and um so um so + + + align:start position:0% +exchange rate different and um so um so +that's commonly done in practice. So um + + align:start position:0% +that's commonly done in practice. So um + + + align:start position:0% +that's commonly done in practice. So um +one so a common assumption for example + + align:start position:0% +one so a common assumption for example + + + align:start position:0% +one so a common assumption for example +is that the probability of transitioning + + align:start position:0% +is that the probability of transitioning + + + align:start position:0% +is that the probability of transitioning +from two to three so moving up by um + + align:start position:0% +from two to three so moving up by um + + + align:start position:0% +from two to three so moving up by um +half Okay. So, you know, so you're + + align:start position:0% +half Okay. So, you know, so you're + + + align:start position:0% +half Okay. So, you know, so you're +moving up by half of two to three is the + + align:start position:0% +moving up by half of two to three is the + + + align:start position:0% +moving up by half of two to three is the +same if you were at any other level. So, + + align:start position:0% +same if you were at any other level. So, + + + align:start position:0% +same if you were at any other level. So, +so for example, if you were at four, + + align:start position:0% +so for example, if you were at four, + + + align:start position:0% +so for example, if you were at four, +then the probability of going to six + + align:start position:0% +then the probability of going to six + + + align:start position:0% +then the probability of going to six +would be whatever the probability is of + + align:start position:0% +would be whatever the probability is of + + + align:start position:0% +would be whatever the probability is of +going from two to three. Okay? Because + + align:start position:0% +going from two to three. Okay? Because + + + align:start position:0% +going from two to three. Okay? Because +if you're at four and the probably going + + align:start position:0% +if you're at four and the probably going + + + align:start position:0% +if you're at four and the probably going +up by half of four to six, okay, that's + + align:start position:0% +up by half of four to six, okay, that's + + + align:start position:0% +up by half of four to six, okay, that's +the assumption. So, um okay, so that's + + align:start position:0% +the assumption. So, um okay, so that's + + + align:start position:0% +the assumption. So, um okay, so that's +called sticky delta and um it's common + + align:start position:0% +called sticky delta and um it's common + + + align:start position:0% +called sticky delta and um it's common +assumption. So if you make that + + align:start position:0% +assumption. So if you make that + + + align:start position:0% +assumption. So if you make that +assumption then you can take the + + align:start position:0% +assumption then you can take the + + + align:start position:0% +assumption then you can take the +information at just today's level and + + align:start position:0% +information at just today's level and + + + align:start position:0% +information at just today's level and +like let's say you know all the digitals + + align:start position:0% +like let's say you know all the digitals + + + align:start position:0% +like let's say you know all the digitals +for from from two and you can make that + + align:start position:0% +for from from two and you can make that + + + align:start position:0% +for from from two and you can make that +assumption let's say + + align:start position:0% +assumption let's say + + + align:start position:0% +assumption let's say +the um probability of a given percentage + + align:start position:0% +the um probability of a given percentage + + + align:start position:0% +the um probability of a given percentage +change is invariant to the starting + + align:start position:0% +change is invariant to the starting + + + align:start position:0% +change is invariant to the starting +level and then you can uh from that + + align:start position:0% +level and then you can uh from that + + + align:start position:0% +level and then you can uh from that +figure out what the probability of going + + align:start position:0% +figure out what the probability of going + + + align:start position:0% +figure out what the probability of going +from four a different level than we're + + align:start position:0% +from four a different level than we're + + + align:start position:0% +from four a different level than we're +at today is to all these different + + align:start position:0% +at today is to all these different + + + align:start position:0% +at today is to all these different +levels. Okay, so you can go from a a + + align:start position:0% +levels. Okay, so you can go from a a + + + align:start position:0% +levels. Okay, so you can go from a a +vector bit of information that the + + align:start position:0% +vector bit of information that the + + + align:start position:0% +vector bit of information that the +market is giving you to a matrix and + + align:start position:0% +market is giving you to a matrix and + + + align:start position:0% +market is giving you to a matrix and +that matrix is called transition matrix + + align:start position:0% +that matrix is called transition matrix + + + align:start position:0% +that matrix is called transition matrix +and um so we're going to in this talk + + align:start position:0% +and um so we're going to in this talk + + + align:start position:0% +and um so we're going to in this talk +assume that somebody's made such an + + align:start position:0% +assume that somebody's made such an + + + align:start position:0% +assume that somebody's made such an +assumption and so you actually know this + + align:start position:0% +assumption and so you actually know this + + + align:start position:0% +assumption and so you actually know this +matrix. Okay, so you actually know if as + + align:start position:0% +matrix. Okay, so you actually know if as + + + align:start position:0% +matrix. Okay, so you actually know if as +a starting point what the prices are. of + + align:start position:0% +a starting point what the prices are. of + + + align:start position:0% +a starting point what the prices are. of +these aerody securities or binary + + align:start position:0% +these aerody securities or binary + + + align:start position:0% +these aerody securities or binary +options starting from any level and + + align:start position:0% +options starting from any level and + + + align:start position:0% +options starting from any level and +going to any level. + + align:start position:0% +going to any level. + + + align:start position:0% +going to any level. +So um okay so + + align:start position:0% +So um okay so + + + align:start position:0% +So um okay so +now um + + align:start position:0% +now um + + + align:start position:0% +now um +let's say + + align:start position:0% +let's say + + + align:start position:0% +let's say +I think in order to + + align:start position:0% +I think in order to + + + align:start position:0% +I think in order to +um + + align:start position:0% +um + + + align:start position:0% +um +to get through the my whole talk I'm + + align:start position:0% +to get through the my whole talk I'm + + + align:start position:0% +to get through the my whole talk I'm +going to skip these slides because + + align:start position:0% +going to skip these slides because + + + align:start position:0% +going to skip these slides because +they're kind of like just being very + + align:start position:0% +they're kind of like just being very + + + align:start position:0% +they're kind of like just being very +precise about what some terms mean that + + align:start position:0% +precise about what some terms mean that + + + align:start position:0% +precise about what some terms mean that +aren't going to be that important for + + align:start position:0% +aren't going to be that important for + + + align:start position:0% +aren't going to be that important for +the overall story. + + align:start position:0% +the overall story. + + + align:start position:0% +the overall story. +So um + + align:start position:0% +So um + + + align:start position:0% +So um +okay so let's go to this slide + + align:start position:0% +okay so let's go to this slide + + + align:start position:0% +okay so let's go to this slide +and so we think of there being just a + + align:start position:0% +and so we think of there being just a + + + align:start position:0% +and so we think of there being just a +single source of uncertainty X which + + align:start position:0% +single source of uncertainty X which + + + align:start position:0% +single source of uncertainty X which +could be dollar euro and um we imagine + + align:start position:0% +could be dollar euro and um we imagine + + + align:start position:0% +could be dollar euro and um we imagine +that we have this matrix of error + + align:start position:0% +that we have this matrix of error + + + align:start position:0% +that we have this matrix of error +security prices. We know every number in + + align:start position:0% +security prices. We know every number in + + + align:start position:0% +security prices. We know every number in +this matrix and we ask what does the + + align:start position:0% +this matrix and we ask what does the + + + align:start position:0% +this matrix and we ask what does the +market believe about transitions + + align:start position:0% +market believe about transitions + + + align:start position:0% +market believe about transitions +from any place to any place? + + align:start position:0% +from any place to any place? + + + align:start position:0% +from any place to any place? +What does the market believe is the + + align:start position:0% +What does the market believe is the + + + align:start position:0% +What does the market believe is the +frequency of these transitions? Now + + align:start position:0% +frequency of these transitions? Now + + + align:start position:0% +frequency of these transitions? Now +suppose that the number that's + + align:start position:0% +suppose that the number that's + + + align:start position:0% +suppose that the number that's +indicating the price of the area + + align:start position:0% +indicating the price of the area + + + align:start position:0% +indicating the price of the area +security going from two to three suppose + + align:start position:0% +security going from two to three suppose + + + align:start position:0% +security going from two to three suppose +that number is say 0.1. + + align:start position:0% +that number is say 0.1. + + + align:start position:0% +that number is say 0.1. +Now what does it mean? It just means + + align:start position:0% +Now what does it mean? It just means + + + align:start position:0% +Now what does it mean? It just means +that you pay 10 cents today for security + + align:start position:0% +that you pay 10 cents today for security + + + align:start position:0% +that you pay 10 cents today for security +paying a dollar just if you go from two + + align:start position:0% +paying a dollar just if you go from two + + + align:start position:0% +paying a dollar just if you go from two +to three. That's all it means. Now you + + align:start position:0% +to three. That's all it means. Now you + + + align:start position:0% +to three. That's all it means. Now you +can ask what is the frequency with which + + align:start position:0% +can ask what is the frequency with which + + + align:start position:0% +can ask what is the frequency with which +you go from two to three. + + align:start position:0% +you go from two to three. + + + align:start position:0% +you go from two to three. +It need not be 10%. + + align:start position:0% +It need not be 10%. + + + align:start position:0% +It need not be 10%. +There's at least two reasons why the 10 + + align:start position:0% +There's at least two reasons why the 10 + + + align:start position:0% +There's at least two reasons why the 10 +cent price could differ from the + + align:start position:0% +cent price could differ from the + + + align:start position:0% +cent price could differ from the +probability of going from where you are + + align:start position:0% +probability of going from where you are + + + align:start position:0% +probability of going from where you are +to where you pay you get paid. Um, one + + align:start position:0% +to where you pay you get paid. Um, one + + + align:start position:0% +to where you pay you get paid. Um, one +such reason is simply time value of + + align:start position:0% +such reason is simply time value of + + + align:start position:0% +such reason is simply time value of +money. Okay. So, if you were to buy all + + align:start position:0% +money. Okay. So, if you were to buy all + + + align:start position:0% +money. Okay. So, if you were to buy all +the air securities, the one paying off + + align:start position:0% +the air securities, the one paying off + + + align:start position:0% +the air securities, the one paying off +in every state, you know, you have one + + align:start position:0% +in every state, you know, you have one + + + align:start position:0% +in every state, you know, you have one +for every state, you'll find that the + + align:start position:0% +for every state, you'll find that the + + + align:start position:0% +for every state, you'll find that the +total cost is less than one. even though + + align:start position:0% +total cost is less than one. even though + + + align:start position:0% +total cost is less than one. even though +the payoff for sure is one from the + + align:start position:0% +the payoff for sure is one from the + + + align:start position:0% +the payoff for sure is one from the +portfolio and that's simply because of + + align:start position:0% +portfolio and that's simply because of + + + align:start position:0% +portfolio and that's simply because of +time value of money you know so when you + + align:start position:0% +time value of money you know so when you + + + align:start position:0% +time value of money you know so when you +put a dollar in the bank today you + + align:start position:0% +put a dollar in the bank today you + + + align:start position:0% +put a dollar in the bank today you +actually get more than a dollar back uh + + align:start position:0% +actually get more than a dollar back uh + + + align:start position:0% +actually get more than a dollar back uh +you know when you pull out at the end of + + align:start position:0% +you know when you pull out at the end of + + + align:start position:0% +you know when you pull out at the end of +the year and um + + align:start position:0% +the year and um + + + align:start position:0% +the year and um +so and if you do the inverse problem how + + align:start position:0% +so and if you do the inverse problem how + + + align:start position:0% +so and if you do the inverse problem how +much do you have to put in the bank + + align:start position:0% +much do you have to put in the bank + + + align:start position:0% +much do you have to put in the bank +today in order to have a dollar at the + + align:start position:0% +today in order to have a dollar at the + + + align:start position:0% +today in order to have a dollar at the +end of the year it might be you know 95 + + align:start position:0% +end of the year it might be you know 95 + + + align:start position:0% +end of the year it might be you know 95 +cents and so uh Um, so that's called + + align:start position:0% +cents and so uh Um, so that's called + + + align:start position:0% +cents and so uh Um, so that's called +time value money. And so just the fact + + align:start position:0% +time value money. And so just the fact + + + align:start position:0% +time value money. And so just the fact +that you have to pay now for the air + + align:start position:0% +that you have to pay now for the air + + + align:start position:0% +that you have to pay now for the air +debris security and you only get paid + + align:start position:0% +debris security and you only get paid + + + align:start position:0% +debris security and you only get paid +off at the end of the year that has that + + align:start position:0% +off at the end of the year that has that + + + align:start position:0% +off at the end of the year that has that +causes this this price of 10 cents to be + + align:start position:0% +causes this this price of 10 cents to be + + + align:start position:0% +causes this this price of 10 cents to be +time money causes it to be lower. Okay. + + align:start position:0% +time money causes it to be lower. Okay. + + + align:start position:0% +time money causes it to be lower. Okay. +So so that's just discounting for for + + align:start position:0% +So so that's just discounting for for + + + align:start position:0% +So so that's just discounting for for +time. That's just interest rates are + + align:start position:0% +time. That's just interest rates are + + + align:start position:0% +time. That's just interest rates are +positive. So that's one effect. Now + + align:start position:0% +positive. So that's one effect. Now + + + align:start position:0% +positive. So that's one effect. Now +there's another effect which is called + + align:start position:0% +there's another effect which is called + + + align:start position:0% +there's another effect which is called +risk aversion and um so risk aversion is + + align:start position:0% +risk aversion and um so risk aversion is + + + align:start position:0% +risk aversion and um so risk aversion is +is the + + align:start position:0% +is the + + + align:start position:0% +is the +thought that + + align:start position:0% +thought that + + + align:start position:0% +thought that +um + + align:start position:0% + + + + align:start position:0% + +that even if the interest rate was zero + + align:start position:0% +that even if the interest rate was zero + + + align:start position:0% +that even if the interest rate was zero +to extract from abstract away from the + + align:start position:0% +to extract from abstract away from the + + + align:start position:0% +to extract from abstract away from the +effect I just described um that it still + + align:start position:0% +effect I just described um that it still + + + align:start position:0% +effect I just described um that it still +may be the case that + + align:start position:0% +may be the case that + + + align:start position:0% +may be the case that +a 10-cent price paid for an air debris + + align:start position:0% +a 10-cent price paid for an air debris + + + align:start position:0% +a 10-cent price paid for an air debris +security transitioning from two to three + + align:start position:0% +security transitioning from two to three + + + align:start position:0% +security transitioning from two to three +is different from the probability of + + align:start position:0% +is different from the probability of + + + align:start position:0% +is different from the probability of +such a transition. The real world + + align:start position:0% +such a transition. The real world + + + align:start position:0% +such a transition. The real world +probability of such a transition + + align:start position:0% +probability of such a transition + + + align:start position:0% +probability of such a transition +because of because for example it may be + + align:start position:0% +because of because for example it may be + + + align:start position:0% +because of because for example it may be +say quite desirable to get money in that + + align:start position:0% +say quite desirable to get money in that + + + align:start position:0% +say quite desirable to get money in that +state in which case uh 10 cents is over + + align:start position:0% +state in which case uh 10 cents is over + + + align:start position:0% +state in which case uh 10 cents is over +the real world probability. Okay. uh or + + align:start position:0% +the real world probability. Okay. uh or + + + align:start position:0% +the real world probability. Okay. uh or +it could be the opposite that maybe it's + + align:start position:0% +it could be the opposite that maybe it's + + + align:start position:0% +it could be the opposite that maybe it's +not desirable to get money in that state + + align:start position:0% +not desirable to get money in that state + + + align:start position:0% +not desirable to get money in that state +in which case 10 cents is under the real + + align:start position:0% +in which case 10 cents is under the real + + + align:start position:0% +in which case 10 cents is under the real +world probability. So + + align:start position:0% +world probability. So + + + align:start position:0% +world probability. So +um so give you a concrete more concrete + + align:start position:0% +um so give you a concrete more concrete + + + align:start position:0% +um so give you a concrete more concrete +example + + align:start position:0% +example + + + align:start position:0% +example +um + + align:start position:0% +um + + + align:start position:0% +um +let's say + + align:start position:0% +let's say + + + align:start position:0% +let's say +um well let's say instead of something + + align:start position:0% +um well let's say instead of something + + + align:start position:0% +um well let's say instead of something +maybe a little closer to home is um + + align:start position:0% +maybe a little closer to home is um + + + align:start position:0% +maybe a little closer to home is um +let's say this is S&P 500 and I know the + + align:start position:0% +let's say this is S&P 500 and I know the + + + align:start position:0% +let's say this is S&P 500 and I know the +values are very different than the + + align:start position:0% +values are very different than the + + + align:start position:0% +values are very different than the +numbers I've indicated here but let's + + align:start position:0% +numbers I've indicated here but let's + + + align:start position:0% +numbers I've indicated here but let's +just you know forget about the actual + + align:start position:0% +just you know forget about the actual + + + align:start position:0% +just you know forget about the actual +numbers and um so so the point is is + + align:start position:0% +numbers and um so so the point is is + + + align:start position:0% +numbers and um so so the point is is +compare + + align:start position:0% +compare + + + align:start position:0% +compare +Let's suppose that it's equally likely + + align:start position:0% +Let's suppose that it's equally likely + + + align:start position:0% +Let's suppose that it's equally likely +in terms of true probabilities to go + + align:start position:0% +in terms of true probabilities to go + + + align:start position:0% +in terms of true probabilities to go +from two to three as it is to go from + + align:start position:0% +from two to three as it is to go from + + + align:start position:0% +from two to three as it is to go from +two to one. So we have two area debris + + align:start position:0% +two to one. So we have two area debris + + + align:start position:0% +two to one. So we have two area debris +securities. + + align:start position:0% +securities. + + + align:start position:0% +securities. +One struck at one, the other struck at + + align:start position:0% +One struck at one, the other struck at + + + align:start position:0% +One struck at one, the other struck at +three. And I'm telling you that it's + + align:start position:0% +three. And I'm telling you that it's + + + align:start position:0% +three. And I'm telling you that it's +equally likely that you go up by one as + + align:start position:0% +equally likely that you go up by one as + + + align:start position:0% +equally likely that you go up by one as +is go down by one. Uh now you can ask + + align:start position:0% +is go down by one. Uh now you can ask + + + align:start position:0% +is go down by one. Uh now you can ask +the question, does it necessarily mean + + align:start position:0% +the question, does it necessarily mean + + + align:start position:0% +the question, does it necessarily mean +that the prices of these securities that + + align:start position:0% +that the prices of these securities that + + + align:start position:0% +that the prices of these securities that +pay a dollar are the same? And the + + align:start position:0% +pay a dollar are the same? And the + + + align:start position:0% +pay a dollar are the same? And the +answer is no, not necessarily. And um + + align:start position:0% +answer is no, not necessarily. And um + + + align:start position:0% +answer is no, not necessarily. And um +actually the sort of standard thinking + + align:start position:0% +actually the sort of standard thinking + + + align:start position:0% +actually the sort of standard thinking +in financial academic circles is that + + align:start position:0% +in financial academic circles is that + + + align:start position:0% +in financial academic circles is that +for S&P 500, it would cost more to buy + + align:start position:0% +for S&P 500, it would cost more to buy + + + align:start position:0% +for S&P 500, it would cost more to buy +this aerody security than it would be + + align:start position:0% +this aerody security than it would be + + + align:start position:0% +this aerody security than it would be +than it would cost to buy that one even + + align:start position:0% +than it would cost to buy that one even + + + align:start position:0% +than it would cost to buy that one even +though everyone agrees that it's equally + + align:start position:0% +though everyone agrees that it's equally + + + align:start position:0% +though everyone agrees that it's equally +likely to get paid from from them from + + align:start position:0% +likely to get paid from from them from + + + align:start position:0% +likely to get paid from from them from +each of them. And the reason that um + + align:start position:0% +each of them. And the reason that um + + + align:start position:0% +each of them. And the reason that um +it's thought to cost more to buy this + + align:start position:0% +it's thought to cost more to buy this + + + align:start position:0% +it's thought to cost more to buy this +one than it is to buy that one is + + align:start position:0% +one than it is to buy that one is + + + align:start position:0% +one than it is to buy that one is +because this one has an insurance value. + + align:start position:0% +because this one has an insurance value. + + + align:start position:0% +because this one has an insurance value. +So the thinking is that on average + + align:start position:0% +So the thinking is that on average + + + align:start position:0% +So the thinking is that on average +people are long the stocks in the stock + + align:start position:0% +people are long the stocks in the stock + + + align:start position:0% +people are long the stocks in the stock +market and that that means that they're + + align:start position:0% +market and that that means that they're + + + align:start position:0% +market and that that means that they're +really upset when the stocks fall and so + + align:start position:0% +really upset when the stocks fall and so + + + align:start position:0% +really upset when the stocks fall and so +they really like this one that ends up + + align:start position:0% +they really like this one that ends up + + + align:start position:0% +they really like this one that ends up +paying should the stock market fall from + + align:start position:0% +paying should the stock market fall from + + + align:start position:0% +paying should the stock market fall from +two to one. Okay. Uh whereas this one, + + align:start position:0% +two to one. Okay. Uh whereas this one, + + + align:start position:0% +two to one. Okay. Uh whereas this one, +while it's nice to get money, um let's + + align:start position:0% +while it's nice to get money, um let's + + + align:start position:0% +while it's nice to get money, um let's +say you're already fairly wealthy from + + align:start position:0% +say you're already fairly wealthy from + + + align:start position:0% +say you're already fairly wealthy from +the fact that you're owning stocks and + + align:start position:0% +the fact that you're owning stocks and + + + align:start position:0% +the fact that you're owning stocks and +the stock market went up. So uh so you + + align:start position:0% +the stock market went up. So uh so you + + + align:start position:0% +the stock market went up. So uh so you +you you know you'll pay a positive + + align:start position:0% +you you know you'll pay a positive + + + align:start position:0% +you you know you'll pay a positive +amount for this security, but not as + + align:start position:0% +amount for this security, but not as + + + align:start position:0% +amount for this security, but not as +much as you pay for this one. Okay. + + align:start position:0% +much as you pay for this one. Okay. + + + align:start position:0% +much as you pay for this one. Okay. +Okay. So so that's called risk aversion. + + align:start position:0% + + + + align:start position:0% + +So what we want to do is go from the + + align:start position:0% +So what we want to do is go from the + + + align:start position:0% +So what we want to do is go from the +prices that are contaminated let's say + + align:start position:0% +prices that are contaminated let's say + + + align:start position:0% +prices that are contaminated let's say +by time value of money effects and by + + align:start position:0% +by time value of money effects and by + + + align:start position:0% +by time value of money effects and by +risk aversion effects and we want to + + align:start position:0% +risk aversion effects and we want to + + + align:start position:0% +risk aversion effects and we want to +cleanse them of that contamination and + + align:start position:0% +cleanse them of that contamination and + + + align:start position:0% +cleanse them of that contamination and +try to extract what the market believes + + align:start position:0% +try to extract what the market believes + + + align:start position:0% +try to extract what the market believes +are the frequencies of the future + + align:start position:0% +are the frequencies of the future + + + align:start position:0% +are the frequencies of the future +states. Okay. + + align:start position:0% + + + + align:start position:0% + +So I'll tell you that this was thought + + align:start position:0% +So I'll tell you that this was thought + + + align:start position:0% +So I'll tell you that this was thought +to be impossible before the Ross paper + + align:start position:0% +to be impossible before the Ross paper + + + align:start position:0% +to be impossible before the Ross paper +and in fact you know without making + + align:start position:0% +and in fact you know without making + + + align:start position:0% +and in fact you know without making +assumptions it is impossible. So all + + align:start position:0% +assumptions it is impossible. So all + + + align:start position:0% +assumptions it is impossible. So all +Ross did is make some assumptions that + + align:start position:0% +Ross did is make some assumptions that + + + align:start position:0% +Ross did is make some assumptions that +are thought to be fairly mild and um by + + align:start position:0% +are thought to be fairly mild and um by + + + align:start position:0% +are thought to be fairly mild and um by +some including me and um so he you know + + align:start position:0% +some including me and um so he you know + + + align:start position:0% +some including me and um so he you know +essentially in in essence showed the + + align:start position:0% +essentially in in essence showed the + + + align:start position:0% +essentially in in essence showed the +power of some assumptions that's you + + align:start position:0% +power of some assumptions that's you + + + align:start position:0% +power of some assumptions that's you +know one way of thinking about it. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% +So + + + align:start position:0% +So +um so again let's denote by R the + + align:start position:0% +um so again let's denote by R the + + + align:start position:0% +um so again let's denote by R the +recovered probability measure which will + + align:start position:0% +recovered probability measure which will + + + align:start position:0% +recovered probability measure which will +tell us the market beliefs about the + + align:start position:0% +tell us the market beliefs about the + + + align:start position:0% +tell us the market beliefs about the +frequencies of future states and um we + + align:start position:0% +frequencies of future states and um we + + + align:start position:0% +frequencies of future states and um we +don't know R when we start what we do + + align:start position:0% +don't know R when we start what we do + + + align:start position:0% +don't know R when we start what we do +know is these aerody security prices I'm + + align:start position:0% +know is these aerody security prices I'm + + + align:start position:0% +know is these aerody security prices I'm +assuming and uh we'll denote those by a + + align:start position:0% +assuming and uh we'll denote those by a + + + align:start position:0% +assuming and uh we'll denote those by a +for arrow so um + + align:start position:0% +for arrow so um + + + align:start position:0% +for arrow so um +so so what Ross' paper does is it says + + align:start position:0% +so so what Ross' paper does is it says + + + align:start position:0% +so so what Ross' paper does is it says +you know A and if you're willing to make + + align:start position:0% +you know A and if you're willing to make + + + align:start position:0% +you know A and if you're willing to make +the following assumptions then you'll + + align:start position:0% +the following assumptions then you'll + + + align:start position:0% +the following assumptions then you'll +know R. So what are the assumptions? + + align:start position:0% +know R. So what are the assumptions? + + + align:start position:0% +know R. So what are the assumptions? +Well before I tell you the assumptions I + + align:start position:0% +Well before I tell you the assumptions I + + + align:start position:0% +Well before I tell you the assumptions I +have to use tell you some terminology so + + align:start position:0% +have to use tell you some terminology so + + + align:start position:0% +have to use tell you some terminology so +that you understand the assumptions. + + align:start position:0% +that you understand the assumptions. + + + align:start position:0% +that you understand the assumptions. +So um he'll work with a pricing matrix A + + align:start position:0% +So um he'll work with a pricing matrix A + + + align:start position:0% +So um he'll work with a pricing matrix A +which we've actually been going through. + + align:start position:0% +which we've actually been going through. + + + align:start position:0% +which we've actually been going through. +So that's um the erod security prices + + align:start position:0% +So that's um the erod security prices + + + align:start position:0% +So that's um the erod security prices +indexed by starting state and final + + align:start position:0% +indexed by starting state and final + + + align:start position:0% +indexed by starting state and final +state which we call X is starting state + + align:start position:0% +state which we call X is starting state + + + align:start position:0% +state which we call X is starting state +Y is final state. Then there'll be the + + align:start position:0% +Y is final state. Then there'll be the + + + align:start position:0% +Y is final state. Then there'll be the +desired output from this analysis which + + align:start position:0% +desired output from this analysis which + + + align:start position:0% +desired output from this analysis which +he calls natural probability transition + + align:start position:0% +he calls natural probability transition + + + align:start position:0% +he calls natural probability transition +matrix. So these are the markets beliefs + + align:start position:0% +matrix. So these are the markets beliefs + + + align:start position:0% +matrix. So these are the markets beliefs +for every starting value X and for every + + align:start position:0% +for every starting value X and for every + + + align:start position:0% +for every starting value X and for every +final value Y. Then there'll be + + align:start position:0% +final value Y. Then there'll be + + + align:start position:0% +final value Y. Then there'll be +something called pricing kernel which is + + align:start position:0% +something called pricing kernel which is + + + align:start position:0% +something called pricing kernel which is +literally the ratio of these aerody + + align:start position:0% +literally the ratio of these aerody + + + align:start position:0% +literally the ratio of these aerody +security prices to these uh output + + align:start position:0% +security prices to these uh output + + + align:start position:0% +security prices to these uh output +natural probabilities. + + align:start position:0% +natural probabilities. + + + align:start position:0% +natural probabilities. +So if you want to get an understanding + + align:start position:0% +So if you want to get an understanding + + + align:start position:0% +So if you want to get an understanding +of what this pricing kernel is, you can + + align:start position:0% +of what this pricing kernel is, you can + + + align:start position:0% +of what this pricing kernel is, you can +think of it as an attempt to capture + + align:start position:0% +think of it as an attempt to capture + + + align:start position:0% +think of it as an attempt to capture +the effects + + align:start position:0% +the effects + + + align:start position:0% +the effects +from time value of money and from risk + + align:start position:0% +from time value of money and from risk + + + align:start position:0% +from time value of money and from risk +aversion. So it's like a nor think of it + + align:start position:0% +aversion. So it's like a nor think of it + + + align:start position:0% +aversion. So it's like a nor think of it +as a normalization. You start with a and + + align:start position:0% +as a normalization. You start with a and + + + align:start position:0% +as a normalization. You start with a and +a is actually affected by three things. + + align:start position:0% +a is actually affected by three things. + + + align:start position:0% +a is actually affected by three things. +It's affected by the unknown real world + + align:start position:0% +It's affected by the unknown real world + + + align:start position:0% +It's affected by the unknown real world +probabilities or at least markets + + align:start position:0% +probabilities or at least markets + + + align:start position:0% +probabilities or at least markets +beliefs of them. + + align:start position:0% +beliefs of them. + + + align:start position:0% +beliefs of them. +A is also affected by a second thing + + align:start position:0% +A is also affected by a second thing + + + align:start position:0% +A is also affected by a second thing +which is time value of money and A is + + align:start position:0% +which is time value of money and A is + + + align:start position:0% +which is time value of money and A is +affected by a third thing which is risk + + align:start position:0% +affected by a third thing which is risk + + + align:start position:0% +affected by a third thing which is risk +aversion. So if we take A and divide by + + align:start position:0% +aversion. So if we take A and divide by + + + align:start position:0% +aversion. So if we take A and divide by +P then we're normalizing for the first + + align:start position:0% +P then we're normalizing for the first + + + align:start position:0% +P then we're normalizing for the first +effect the frequencies. And so we're + + align:start position:0% +effect the frequencies. And so we're + + + align:start position:0% +effect the frequencies. And so we're +left with just the combined effect from + + align:start position:0% +left with just the combined effect from + + + align:start position:0% +left with just the combined effect from +time value of money and from risk + + align:start position:0% +time value of money and from risk + + + align:start position:0% +time value of money and from risk +aversion. + + align:start position:0% + + + + align:start position:0% + +And so let's say if if um if people if + + align:start position:0% +And so let's say if if um if people if + + + align:start position:0% +And so let's say if if um if people if +interest rate were zero and people were + + align:start position:0% +interest rate were zero and people were + + + align:start position:0% +interest rate were zero and people were +risk neutral then we would actually + + align:start position:0% +risk neutral then we would actually + + + align:start position:0% +risk neutral then we would actually +expect + + align:start position:0% +expect + + + align:start position:0% +expect +a to equal p and so this ratio would be + + align:start position:0% +a to equal p and so this ratio would be + + + align:start position:0% +a to equal p and so this ratio would be +just constant. + + align:start position:0% + + + + align:start position:0% + +So um so Ross talks about a world with a + + align:start position:0% +So um so Ross talks about a world with a + + + align:start position:0% +So um so Ross talks about a world with a +representative investor + + align:start position:0% +representative investor + + + align:start position:0% +representative investor +and um essentially + + align:start position:0% +and um essentially + + + align:start position:0% +and um essentially +um + + align:start position:0% +um + + + align:start position:0% +um +this is an assumption this equation + + align:start position:0% +this is an assumption this equation + + + align:start position:0% +this is an assumption this equation +you're seeing here + + align:start position:0% +you're seeing here + + + align:start position:0% +you're seeing here +and it's a it's it's + + align:start position:0% +and it's a it's it's + + + align:start position:0% +and it's a it's it's +an assumption on the form that a + + align:start position:0% +an assumption on the form that a + + + align:start position:0% +an assumption on the form that a +function of two variables takes. So phi + + align:start position:0% +function of two variables takes. So phi + + + align:start position:0% +function of two variables takes. So phi +first of all is a positive function. So + + align:start position:0% +first of all is a positive function. So + + + align:start position:0% +first of all is a positive function. So +fi is positive as opposed to you know so + + align:start position:0% +fi is positive as opposed to you know so + + + align:start position:0% +fi is positive as opposed to you know so +fi cannot take negative values because + + align:start position:0% +fi cannot take negative values because + + + align:start position:0% +fi cannot take negative values because +both a and p are positive and um + + align:start position:0% +both a and p are positive and um + + + align:start position:0% +both a and p are positive and um +it's a fi is a function of two variables + + align:start position:0% +it's a fi is a function of two variables + + + align:start position:0% +it's a fi is a function of two variables +x and y and what this assumption is + + align:start position:0% +x and y and what this assumption is + + + align:start position:0% +x and y and what this assumption is +doing is it's saying well let's put + + align:start position:0% +doing is it's saying well let's put + + + align:start position:0% +doing is it's saying well let's put +structure on this function fi because + + align:start position:0% +structure on this function fi because + + + align:start position:0% +structure on this function fi because +it'll help us to find it if we put the + + align:start position:0% +it'll help us to find it if we put the + + + align:start position:0% +it'll help us to find it if we put the +structure so this is the first sort of + + align:start position:0% +structure so this is the first sort of + + + align:start position:0% +structure so this is the first sort of +key assumption actually that um the the + + align:start position:0% +key assumption actually that um the the + + + align:start position:0% +key assumption actually that um the the +function of two variables x and y + + align:start position:0% +function of two variables x and y + + + align:start position:0% +function of two variables x and y +actually has the form on the right which + + align:start position:0% +actually has the form on the right which + + + align:start position:0% +actually has the form on the right which +for a moment just ignore the delta for a + + align:start position:0% +for a moment just ignore the delta for a + + + align:start position:0% +for a moment just ignore the delta for a +moment and then you can see that what + + align:start position:0% +moment and then you can see that what + + + align:start position:0% +moment and then you can see that what +you have on the right if you ignore + + align:start position:0% +you have on the right if you ignore + + + align:start position:0% +you have on the right if you ignore +delta if you think of delta as one is + + align:start position:0% +delta if you think of delta as one is + + + align:start position:0% +delta if you think of delta as one is +you have a function of y and then you + + align:start position:0% +you have a function of y and then you + + + align:start position:0% +you have a function of y and then you +have the same function of x okay so it's + + align:start position:0% +have the same function of x okay so it's + + + align:start position:0% +have the same function of x okay so it's +written in a convoluted way with this u + + align:start position:0% +written in a convoluted way with this u + + + align:start position:0% +written in a convoluted way with this u +prime and c and all that stuff but if + + align:start position:0% +prime and c and all that stuff but if + + + align:start position:0% +prime and c and all that stuff but if +delta is one then you have a fraction + + align:start position:0% +delta is one then you have a fraction + + + align:start position:0% +delta is one then you have a fraction +whose numerator is a function of y and + + align:start position:0% +whose numerator is a function of y and + + + align:start position:0% +whose numerator is a function of y and +whose denominator is the same function + + align:start position:0% +whose denominator is the same function + + + align:start position:0% +whose denominator is the same function +but of x okay + + align:start position:0% +but of x okay + + + align:start position:0% +but of x okay +and Um so um so that's a real that's + + align:start position:0% +and Um so um so that's a real that's + + + align:start position:0% +and Um so um so that's a real that's +actually in essence what that does is it + + align:start position:0% +actually in essence what that does is it + + + align:start position:0% +actually in essence what that does is it +reduces the dimensionality of the thing + + align:start position:0% +reduces the dimensionality of the thing + + + align:start position:0% +reduces the dimensionality of the thing +we're searching for by a lot. So we + + align:start position:0% +we're searching for by a lot. So we + + + align:start position:0% +we're searching for by a lot. So we +started by searching for a function phi + + align:start position:0% +started by searching for a function phi + + + align:start position:0% +started by searching for a function phi +of two variables and we by this + + align:start position:0% +of two variables and we by this + + + align:start position:0% +of two variables and we by this +assumption reduce the search to a + + align:start position:0% +assumption reduce the search to a + + + align:start position:0% +assumption reduce the search to a +function of one variable which is say + + align:start position:0% +function of one variable which is say + + + align:start position:0% +function of one variable which is say +the function in the numerator which is + + align:start position:0% +the function in the numerator which is + + + align:start position:0% +the function in the numerator which is +the same thing as the function in the + + align:start position:0% +the same thing as the function in the + + + align:start position:0% +the same thing as the function in the +denominator. So okay and well so so now + + align:start position:0% +denominator. So okay and well so so now + + + align:start position:0% +denominator. So okay and well so so now +let's bring back delta and um delta is a + + align:start position:0% +let's bring back delta and um delta is a + + + align:start position:0% +let's bring back delta and um delta is a +scalar here and it's a positive scalar + + align:start position:0% +scalar here and it's a positive scalar + + + align:start position:0% +scalar here and it's a positive scalar +and so we need to search for that as + + align:start position:0% +and so we need to search for that as + + + align:start position:0% +and so we need to search for that as +well. So in the end we reduce the search + + align:start position:0% +well. So in the end we reduce the search + + + align:start position:0% +well. So in the end we reduce the search +to a function of one variable and a + + align:start position:0% +to a function of one variable and a + + + align:start position:0% +to a function of one variable and a +scalar delta. So, so the economic + + align:start position:0% +scalar delta. So, so the economic + + + align:start position:0% +scalar delta. So, so the economic +meaning of of of + + align:start position:0% +meaning of of of + + + align:start position:0% +meaning of of of +first of all the function of one + + align:start position:0% +first of all the function of one + + + align:start position:0% +first of all the function of one +variable is it's called marginal utility + + align:start position:0% +variable is it's called marginal utility + + + align:start position:0% +variable is it's called marginal utility +and um it's it's meant to indicate how + + align:start position:0% +and um it's it's meant to indicate how + + + align:start position:0% +and um it's it's meant to indicate how +much happiness you get from each + + align:start position:0% +much happiness you get from each + + + align:start position:0% +much happiness you get from each +additional unit of consumption. So it's + + align:start position:0% +additional unit of consumption. So it's + + + align:start position:0% +additional unit of consumption. So it's +um the typical what we think it looks + + align:start position:0% +um the typical what we think it looks + + + align:start position:0% +um the typical what we think it looks +like as a function of C. this u um u + + align:start position:0% +like as a function of C. this u um u + + + align:start position:0% +like as a function of C. this u um u +prime u prime as a function of c is + + align:start position:0% +prime u prime as a function of c is + + + align:start position:0% +prime u prime as a function of c is +thought to typically look like that. So + + align:start position:0% +thought to typically look like that. So + + + align:start position:0% +thought to typically look like that. So +it's positive meaning every unit of + + align:start position:0% +it's positive meaning every unit of + + + align:start position:0% +it's positive meaning every unit of +consumption makes you happy and uh it's + + align:start position:0% +consumption makes you happy and uh it's + + + align:start position:0% +consumption makes you happy and uh it's +actually declining meaning uh the first + + align:start position:0% +actually declining meaning uh the first + + + align:start position:0% +actually declining meaning uh the first +unit of consumption makes you real + + align:start position:0% +unit of consumption makes you real + + + align:start position:0% +unit of consumption makes you real +happy. Uh then the next unit of + + align:start position:0% +happy. Uh then the next unit of + + + align:start position:0% +happy. Uh then the next unit of +consumption still brings some happiness + + align:start position:0% +consumption still brings some happiness + + + align:start position:0% +consumption still brings some happiness +but not as much and so on. Okay. So so + + align:start position:0% +but not as much and so on. Okay. So so + + + align:start position:0% +but not as much and so on. Okay. So so +um so that's the kind of function we're + + align:start position:0% +um so that's the kind of function we're + + + align:start position:0% +um so that's the kind of function we're +looking for. U prime as a function of C. + + align:start position:0% +looking for. U prime as a function of C. + + + align:start position:0% +looking for. U prime as a function of C. +uh he won't actually find u prime as a + + align:start position:0% +uh he won't actually find u prime as a + + + align:start position:0% +uh he won't actually find u prime as a +function of c. He'll find the + + align:start position:0% +function of c. He'll find the + + + align:start position:0% +function of c. He'll find the +composition + + align:start position:0% +composition + + + align:start position:0% +composition +of u prime with a function c of y. And + + align:start position:0% +of u prime with a function c of y. And + + + align:start position:0% +of u prime with a function c of y. And +um so let's say + + align:start position:0% +um so let's say + + + align:start position:0% +um so let's say +keep that in mind. Okay. So anyway, so + + align:start position:0% +keep that in mind. Okay. So anyway, so + + + align:start position:0% +keep that in mind. Okay. So anyway, so +then there's that delta and that's um + + align:start position:0% +then there's that delta and that's um + + + align:start position:0% +then there's that delta and that's um +again a positive scaler and it's meant + + align:start position:0% +again a positive scaler and it's meant + + + align:start position:0% +again a positive scaler and it's meant +to capture time value of money. Um and + + align:start position:0% +to capture time value of money. Um and + + + align:start position:0% +to capture time value of money. Um and +so that's like the uh the y is the um + + align:start position:0% +so that's like the uh the y is the um + + + align:start position:0% +so that's like the uh the y is the um +state at the end of the period and x is + + align:start position:0% +state at the end of the period and x is + + + align:start position:0% +state at the end of the period and x is +the state at the beginning of the + + align:start position:0% +the state at the beginning of the + + + align:start position:0% +the state at the beginning of the +period. And so that's why delta is + + align:start position:0% +period. And so that's why delta is + + + align:start position:0% +period. And so that's why delta is +associated with the numerator not the + + align:start position:0% +associated with the numerator not the + + + align:start position:0% +associated with the numerator not the +denominator. So delta would be a number + + align:start position:0% +denominator. So delta would be a number + + + align:start position:0% +denominator. So delta would be a number +like 0.9 and that indicates how much + + align:start position:0% +like 0.9 and that indicates how much + + + align:start position:0% +like 0.9 and that indicates how much +discount you give to + + align:start position:0% +discount you give to + + + align:start position:0% +discount you give to +um to let's say happiness received in + + align:start position:0% +um to let's say happiness received in + + + align:start position:0% +um to let's say happiness received in +the future rather than now. Okay. So + + align:start position:0% +the future rather than now. Okay. So + + + align:start position:0% +the future rather than now. Okay. So +okay. + + align:start position:0% +okay. + + + align:start position:0% +okay. +Okay. Now, here's a quote from Ross's + + align:start position:0% +Okay. Now, here's a quote from Ross's + + + align:start position:0% +Okay. Now, here's a quote from Ross's +paper uh that um is his theorem one + + align:start position:0% +paper uh that um is his theorem one + + + align:start position:0% +paper uh that um is his theorem one +that's called the recovery theorem. And + + align:start position:0% +that's called the recovery theorem. And + + + align:start position:0% +that's called the recovery theorem. And +um the only thing is I changed the um + + align:start position:0% +um the only thing is I changed the um + + + align:start position:0% +um the only thing is I changed the um +letters to conform with the letters I'm + + align:start position:0% +letters to conform with the letters I'm + + + align:start position:0% +letters to conform with the letters I'm +using rather than the ones he used. And + + align:start position:0% +using rather than the ones he used. And + + + align:start position:0% +using rather than the ones he used. And +that's because his choice of letters is + + align:start position:0% +that's because his choice of letters is + + + align:start position:0% +that's because his choice of letters is +completely unnatural to me and most + + align:start position:0% +completely unnatural to me and most + + + align:start position:0% +completely unnatural to me and most +people. So uh so um so I don't even want + + align:start position:0% +people. So uh so um so I don't even want + + + align:start position:0% +people. So uh so um so I don't even want +to tell you what he used. So um so + + align:start position:0% +to tell you what he used. So um so + + + align:start position:0% +to tell you what he used. So um so +anyway, whereas I tried to choose + + align:start position:0% +anyway, whereas I tried to choose + + + align:start position:0% +anyway, whereas I tried to choose +letters that make sense. So so I used a + + align:start position:0% +letters that make sense. So so I used a + + + align:start position:0% +letters that make sense. So so I used a +for okay and uh you know so okay. + + align:start position:0% +for okay and uh you know so okay. + + + align:start position:0% +for okay and uh you know so okay. +Okay. So anyway, he says you have a + + align:start position:0% +Okay. So anyway, he says you have a + + + align:start position:0% +Okay. So anyway, he says you have a +world with a representative agent. So + + align:start position:0% +world with a representative agent. So + + + align:start position:0% +world with a representative agent. So +that's um this restriction that's + + align:start position:0% +that's um this restriction that's + + + align:start position:0% +that's um this restriction that's +actually this restriction uh that we + + align:start position:0% +actually this restriction uh that we + + + align:start position:0% +actually this restriction uh that we +talked about on the last slide. And then + + align:start position:0% +talked about on the last slide. And then + + + align:start position:0% +talked about on the last slide. And then +um he says if the pricing matrix which + + align:start position:0% +um he says if the pricing matrix which + + + align:start position:0% +um he says if the pricing matrix which +is the error debris security prices is + + align:start position:0% +is the error debris security prices is + + + align:start position:0% +is the error debris security prices is +positive which means that all entries in + + align:start position:0% +positive which means that all entries in + + + align:start position:0% +positive which means that all entries in +it are strictly above zero or + + align:start position:0% +it are strictly above zero or + + + align:start position:0% +it are strictly above zero or +irreducible which means that some + + align:start position:0% +irreducible which means that some + + + align:start position:0% +irreducible which means that some +entries have zeros with the rest being + + align:start position:0% +entries have zeros with the rest being + + + align:start position:0% +entries have zeros with the rest being +positive uh and there's some structure + + align:start position:0% +positive uh and there's some structure + + + align:start position:0% +positive uh and there's some structure +which we need not get into to where the + + align:start position:0% +which we need not get into to where the + + + align:start position:0% +which we need not get into to where the +zeros are. uh then there exists + + align:start position:0% +zeros are. uh then there exists + + + align:start position:0% +zeros are. uh then there exists +um a unique solution to the problem of + + align:start position:0% +um a unique solution to the problem of + + + align:start position:0% +um a unique solution to the problem of +finding okay he P which is P is actually + + align:start position:0% +finding okay he P which is P is actually + + + align:start position:0% +finding okay he P which is P is actually +market beliefs and I've been calling + + align:start position:0% +market beliefs and I've been calling + + + align:start position:0% +market beliefs and I've been calling +that R in often so so anyway I slipped a + + align:start position:0% +that R in often so so anyway I slipped a + + + align:start position:0% +that R in often so so anyway I slipped a +bit there and called it P but so anyway + + align:start position:0% +bit there and called it P but so anyway + + + align:start position:0% +bit there and called it P but so anyway +so that's market beliefs about the + + align:start position:0% +so that's market beliefs about the + + + align:start position:0% +so that's market beliefs about the +frequencies of future states he'll also + + align:start position:0% +frequencies of future states he'll also + + + align:start position:0% +frequencies of future states he'll also +get as an output the delta which is the + + align:start position:0% +get as an output the delta which is the + + + align:start position:0% +get as an output the delta which is the +scaler positive scaler telling you the + + align:start position:0% +scaler positive scaler telling you the + + + align:start position:0% +scaler positive scaler telling you the +market's timed value of money and + + align:start position:0% +market's timed value of money and + + + align:start position:0% +market's timed value of money and +finally this pricing curve internal phi + + align:start position:0% +finally this pricing curve internal phi + + + align:start position:0% +finally this pricing curve internal phi +which is the ratio of + + align:start position:0% +which is the ratio of + + + align:start position:0% +which is the ratio of +of um a to p. So the point is is that so + + align:start position:0% +of um a to p. So the point is is that so + + + align:start position:0% +of um a to p. So the point is is that so +so what you're supposed to realize even + + align:start position:0% +so what you're supposed to realize even + + + align:start position:0% +so what you're supposed to realize even +though he didn't say it is that as a + + align:start position:0% +though he didn't say it is that as a + + + align:start position:0% +though he didn't say it is that as a +result um well okay so he did say it + + align:start position:0% +result um well okay so he did say it + + + align:start position:0% +result um well okay so he did say it +actually that you're finding P I think + + align:start position:0% +actually that you're finding P I think + + + align:start position:0% +actually that you're finding P I think +that's the main thing + + align:start position:0% +that's the main thing + + + align:start position:0% +that's the main thing +and um so anyway and so there's only one + + align:start position:0% +and um so anyway and so there's only one + + + align:start position:0% +and um so anyway and so there's only one +like he's actually saying if you make + + align:start position:0% +like he's actually saying if you make + + + align:start position:0% +like he's actually saying if you make +these assumptions there's only one + + align:start position:0% +these assumptions there's only one + + + align:start position:0% +these assumptions there's only one +surprisingly there's only one + + align:start position:0% +surprisingly there's only one + + + align:start position:0% +surprisingly there's only one +uh + + align:start position:0% +uh + + + align:start position:0% +uh +possible + + align:start position:0% +possible + + + align:start position:0% +possible +real world or market beliefs that are + + align:start position:0% +real world or market beliefs that are + + + align:start position:0% +real world or market beliefs that are +consistent with the data and the + + align:start position:0% +consistent with the data and the + + + align:start position:0% +consistent with the data and the +assumptions made. Okay. So, so + + align:start position:0% +assumptions made. Okay. So, so + + + align:start position:0% +assumptions made. Okay. So, so +like to give you a sense of what the + + align:start position:0% +like to give you a sense of what the + + + align:start position:0% +like to give you a sense of what the +importance of this result is, um, so + + align:start position:0% +importance of this result is, um, so + + + align:start position:0% +importance of this result is, um, so +prior to his paper, I mean people have + + align:start position:0% +prior to his paper, I mean people have + + + align:start position:0% +prior to his paper, I mean people have +been interested in trying to infer from + + align:start position:0% +been interested in trying to infer from + + + align:start position:0% +been interested in trying to infer from +market prices what the market believes, + + align:start position:0% +market prices what the market believes, + + + align:start position:0% +market prices what the market believes, +but they always thought that you had to + + align:start position:0% +but they always thought that you had to + + + align:start position:0% +but they always thought that you had to +supply + + align:start position:0% +supply + + + align:start position:0% +supply +some parameters that capture market risk + + align:start position:0% +some parameters that capture market risk + + + align:start position:0% +some parameters that capture market risk +aversion. So, so for example, a common + + align:start position:0% +aversion. So, so for example, a common + + + align:start position:0% +aversion. So, so for example, a common +approach is to assume that + + align:start position:0% +approach is to assume that + + + align:start position:0% +approach is to assume that +um you have a representative investor + + align:start position:0% +um you have a representative investor + + + align:start position:0% +um you have a representative investor +and that they have a particular type of + + align:start position:0% +and that they have a particular type of + + + align:start position:0% +and that they have a particular type of +utility function called constant + + align:start position:0% +utility function called constant + + + align:start position:0% +utility function called constant +relative risk aversion and there's a + + align:start position:0% +relative risk aversion and there's a + + + align:start position:0% +relative risk aversion and there's a +parameter in that utility function and + + align:start position:0% +parameter in that utility function and + + + align:start position:0% +parameter in that utility function and +you had to specify the numerical value + + align:start position:0% +you had to specify the numerical value + + + align:start position:0% +you had to specify the numerical value +that parameter takes before you could do + + align:start position:0% +that parameter takes before you could do + + + align:start position:0% +that parameter takes before you could do +before you could learn the market's + + align:start position:0% +before you could learn the market's + + + align:start position:0% +before you could learn the market's +beliefs from prices. and no one ever + + align:start position:0% +beliefs from prices. and no one ever + + + align:start position:0% +beliefs from prices. and no one ever +felt very comfortable specifying that + + align:start position:0% +felt very comfortable specifying that + + + align:start position:0% +felt very comfortable specifying that +parameter. So what Ross essentially did + + align:start position:0% +parameter. So what Ross essentially did + + + align:start position:0% +parameter. So what Ross essentially did +is he managed to uh essentially do the + + align:start position:0% +is he managed to uh essentially do the + + + align:start position:0% +is he managed to uh essentially do the +identification non-parametrically + + align:start position:0% +identification non-parametrically + + + align:start position:0% +identification non-parametrically +and um where you don't have to supply + + align:start position:0% +and um where you don't have to supply + + + align:start position:0% +and um where you don't have to supply +any parameters and so you essentially + + align:start position:0% +any parameters and so you essentially + + + align:start position:0% +any parameters and so you essentially +um + + align:start position:0% +um + + + align:start position:0% +um +just have to buy his assumptions. you + + align:start position:0% +just have to buy his assumptions. you + + + align:start position:0% +just have to buy his assumptions. you +don't have to do any work to actually uh + + align:start position:0% +don't have to do any work to actually uh + + + align:start position:0% +don't have to do any work to actually uh +go from um market prices to markets + + align:start position:0% +go from um market prices to markets + + + align:start position:0% +go from um market prices to markets +beliefs. Okay. So + + align:start position:0% + + + + align:start position:0% + +um Okay. So let's skip these remarks and + + align:start position:0% +um Okay. So let's skip these remarks and + + + align:start position:0% +um Okay. So let's skip these remarks and +um so let me yeah elaborate on the fact + + align:start position:0% +um so let me yeah elaborate on the fact + + + align:start position:0% +um so let me yeah elaborate on the fact +that risk aversion doesn't yeah so you + + align:start position:0% +that risk aversion doesn't yeah so you + + + align:start position:0% +that risk aversion doesn't yeah so you +don't have to supply yeah so the the + + align:start position:0% +don't have to supply yeah so the the + + + align:start position:0% +don't have to supply yeah so the the +exact statement is you don't have to + + align:start position:0% +exact statement is you don't have to + + + align:start position:0% +exact statement is you don't have to +supply a parameter like you don't uh + + align:start position:0% +supply a parameter like you don't uh + + + align:start position:0% +supply a parameter like you don't uh +that describes the amount of the + + align:start position:0% +that describes the amount of the + + + align:start position:0% +that describes the amount of the +market's risk aversion + + align:start position:0% +market's risk aversion + + + align:start position:0% +market's risk aversion +rather you just have to you have to + + align:start position:0% +rather you just have to you have to + + + align:start position:0% +rather you just have to you have to +accept um this assumption I'll show you + + align:start position:0% +accept um this assumption I'll show you + + + align:start position:0% +accept um this assumption I'll show you +this assumption about the structure of + + align:start position:0% +this assumption about the structure of + + + align:start position:0% +this assumption about the structure of +fi. Okay. So if you just accept that + + align:start position:0% +fi. Okay. So if you just accept that + + + align:start position:0% +fi. Okay. So if you just accept that +this function of two variables + + align:start position:0% +this function of two variables + + + align:start position:0% +this function of two variables +is not um doesn't have the the full + + align:start position:0% +is not um doesn't have the the full + + + align:start position:0% +is not um doesn't have the the full +amount of degrees of freedom that a an + + align:start position:0% +amount of degrees of freedom that a an + + + align:start position:0% +amount of degrees of freedom that a an +arbitrary function of two variables has. + + align:start position:0% +arbitrary function of two variables has. + + + align:start position:0% +arbitrary function of two variables has. +It has a reduced number of freedom + + align:start position:0% +It has a reduced number of freedom + + + align:start position:0% +It has a reduced number of freedom +implicit on the right hand side. + + align:start position:0% +implicit on the right hand side. + + + align:start position:0% +implicit on the right hand side. +Okay. So let me maybe um remembering + + align:start position:0% +Okay. So let me maybe um remembering + + + align:start position:0% +Okay. So let me maybe um remembering +that X is actually just a a vector of + + align:start position:0% +that X is actually just a a vector of + + + align:start position:0% +that X is actually just a a vector of +finite length and so is Y. Then think of + + align:start position:0% +finite length and so is Y. Then think of + + + align:start position:0% +finite length and so is Y. Then think of +the left hand side as having degrees of + + align:start position:0% +the left hand side as having degrees of + + + align:start position:0% +the left hand side as having degrees of +freedom n^ squ + + align:start position:0% +freedom n^ squ + + + align:start position:0% +freedom n^ squ +and on the right hand side you're + + align:start position:0% +and on the right hand side you're + + + align:start position:0% +and on the right hand side you're +looking for + + align:start position:0% +looking for + + + align:start position:0% +looking for +that the numerator function is just a + + align:start position:0% +that the numerator function is just a + + + align:start position:0% +that the numerator function is just a +vector of length n and the denominator + + align:start position:0% +vector of length n and the denominator + + + align:start position:0% +vector of length n and the denominator +function is the same function so same + + align:start position:0% +function is the same function so same + + + align:start position:0% +function is the same function so same +vector and then there's also this delta. + + align:start position:0% +vector and then there's also this delta. + + + align:start position:0% +vector and then there's also this delta. +So, so let's say on the left hand side + + align:start position:0% +So, so let's say on the left hand side + + + align:start position:0% +So, so let's say on the left hand side +you're describing something that without + + align:start position:0% +you're describing something that without + + + align:start position:0% +you're describing something that without +restriction is of order n^ squ. So let's + + align:start position:0% +restriction is of order n^ squ. So let's + + + align:start position:0% +restriction is of order n^ squ. So let's +say n is 10. So has 100 degrees of + + align:start position:0% +say n is 10. So has 100 degrees of + + + align:start position:0% +say n is 10. So has 100 degrees of +freedom. And on the right hand side + + align:start position:0% +freedom. And on the right hand side + + + align:start position:0% +freedom. And on the right hand side +you're describing a vector of length 10 + + align:start position:0% +you're describing a vector of length 10 + + + align:start position:0% +you're describing a vector of length 10 +along with a scaler. So 11 degrees of + + align:start position:0% +along with a scaler. So 11 degrees of + + + align:start position:0% +along with a scaler. So 11 degrees of +freedom. So you you have to accept that + + align:start position:0% +freedom. So you you have to accept that + + + align:start position:0% +freedom. So you you have to accept that +you're willing to that okay before you + + align:start position:0% +you're willing to that okay before you + + + align:start position:0% +you're willing to that okay before you +place any restriction it's 100 degrees + + align:start position:0% +place any restriction it's 100 degrees + + + align:start position:0% +place any restriction it's 100 degrees +of freedom. Now you make the restriction + + align:start position:0% +of freedom. Now you make the restriction + + + align:start position:0% +of freedom. Now you make the restriction +it's 11. You have to accept that. And if + + align:start position:0% +it's 11. You have to accept that. And if + + + align:start position:0% +it's 11. You have to accept that. And if +you do then he will like uh say that um + + align:start position:0% +you do then he will like uh say that um + + + align:start position:0% +you do then he will like uh say that um +he'll tell you the 11 entries. That's + + align:start position:0% +he'll tell you the 11 entries. That's + + + align:start position:0% +he'll tell you the 11 entries. That's +it. So you don't have to supply + + align:start position:0% +it. So you don't have to supply + + + align:start position:0% +it. So you don't have to supply +anything. + + align:start position:0% +anything. + + + align:start position:0% +anything. +Okay. So I haven't told you how he'll + + align:start position:0% +Okay. So I haven't told you how he'll + + + align:start position:0% +Okay. So I haven't told you how he'll +find the right. That's probably what + + align:start position:0% +find the right. That's probably what + + + align:start position:0% +find the right. That's probably what +you're asking. How the hell did he get + + align:start position:0% +you're asking. How the hell did he get + + + align:start position:0% +you're asking. How the hell did he get +to 11? Okay. So I haven't shown you + + align:start position:0% +to 11? Okay. So I haven't shown you + + + align:start position:0% +to 11? Okay. So I haven't shown you +that. Yes. Um just really quickly does C + + align:start position:0% +that. Yes. Um just really quickly does C + + + align:start position:0% +that. Yes. Um just really quickly does C +change as a function of time and spot + + align:start position:0% +change as a function of time and spot + + + align:start position:0% +change as a function of time and spot +price. C is not a function of time. and + + align:start position:0% +price. C is not a function of time. and + + + align:start position:0% +price. C is not a function of time. and +to answer your question and uh and then + + align:start position:0% +to answer your question and uh and then + + + align:start position:0% +to answer your question and uh and then +the argument of C + + align:start position:0% +the argument of C + + + align:start position:0% +the argument of C +is is um is could be a price. It's + + align:start position:0% +is is um is could be a price. It's + + + align:start position:0% +is is um is could be a price. It's +allowed to be a price. Okay. Uh so uh + + align:start position:0% +allowed to be a price. Okay. Uh so uh + + + align:start position:0% +allowed to be a price. Okay. Uh so uh +that's how you should think of it. Okay. + + align:start position:0% +that's how you should think of it. Okay. + + + align:start position:0% +that's how you should think of it. Okay. +So there's a lot of time homogeneity + + align:start position:0% +So there's a lot of time homogeneity + + + align:start position:0% +So there's a lot of time homogeneity +in everything he does here. So he'll + + align:start position:0% +in everything he does here. So he'll + + + align:start position:0% +in everything he does here. So he'll +never let anything depend on time + + align:start position:0% +never let anything depend on time + + + align:start position:0% +never let anything depend on time +actually. Okay. uh to answer your + + align:start position:0% +actually. Okay. uh to answer your + + + align:start position:0% +actually. Okay. uh to answer your +question. + + align:start position:0% + + + + align:start position:0% + +Um so I still haven't shown you how he + + align:start position:0% +Um so I still haven't shown you how he + + + align:start position:0% +Um so I still haven't shown you how he +did it. Um and so he uses prone + + align:start position:0% +did it. Um and so he uses prone + + + align:start position:0% +did it. Um and so he uses prone +forbinius theorem + + align:start position:0% +forbinius theorem + + + align:start position:0% +forbinius theorem +and um I don't actually have slides on + + align:start position:0% +and um I don't actually have slides on + + + align:start position:0% +and um I don't actually have slides on +how you actually calculate the 11 + + align:start position:0% +how you actually calculate the 11 + + + align:start position:0% +how you actually calculate the 11 +entries. Um so I think I just have to + + align:start position:0% +entries. Um so I think I just have to + + + align:start position:0% +entries. Um so I think I just have to +refer you to the paper. Um but you're + + align:start position:0% +refer you to the paper. Um but you're + + + align:start position:0% +refer you to the paper. Um but you're +you're he relies on something called + + align:start position:0% +you're he relies on something called + + + align:start position:0% +you're he relies on something called +prone for genius theorem and um I'm + + align:start position:0% +prone for genius theorem and um I'm + + + align:start position:0% +prone for genius theorem and um I'm +going to show you how we my co-author + + align:start position:0% +going to show you how we my co-author + + + align:start position:0% +going to show you how we my co-author +and I + + align:start position:0% +and I + + + align:start position:0% +and I +um actually calculate the analog of + + align:start position:0% +um actually calculate the analog of + + + align:start position:0% +um actually calculate the analog of +those um of that 11dimensional unknown. + + align:start position:0% +those um of that 11dimensional unknown. + + + align:start position:0% +those um of that 11dimensional unknown. +Okay. So um so we're going to work in a + + align:start position:0% +Okay. So um so we're going to work in a + + + align:start position:0% +Okay. So um so we're going to work in a +continuous setting where instead of + + align:start position:0% +continuous setting where instead of + + + align:start position:0% +continuous setting where instead of +looking for a vector and a scaler, we're + + align:start position:0% +looking for a vector and a scaler, we're + + + align:start position:0% +looking for a vector and a scaler, we're +going to look for a function and a + + align:start position:0% +going to look for a function and a + + + align:start position:0% +going to look for a function and a +scalar and uh a function of one variable + + align:start position:0% +scalar and uh a function of one variable + + + align:start position:0% +scalar and uh a function of one variable +and um so so anyway so you'll get a + + align:start position:0% +and um so so anyway so you'll get a + + + align:start position:0% +and um so so anyway so you'll get a +sense of how to do it from ours and + + align:start position:0% +sense of how to do it from ours and + + + align:start position:0% +sense of how to do it from ours and +essentially if you discretize what we + + align:start position:0% +essentially if you discretize what we + + + align:start position:0% +essentially if you discretize what we +do, you'll get what he did. Okay. + + align:start position:0% +do, you'll get what he did. Okay. + + + align:start position:0% +do, you'll get what he did. Okay. +Okay. um let's get forget these remarks + + align:start position:0% +Okay. um let's get forget these remarks + + + align:start position:0% +Okay. um let's get forget these remarks +and let's forget these and um so now + + align:start position:0% +and let's forget these and um so now + + + align:start position:0% +and let's forget these and um so now +we'll get into some theory about + + align:start position:0% +we'll get into some theory about + + + align:start position:0% +we'll get into some theory about +changing numerator. So this is sort of + + align:start position:0% +changing numerator. So this is sort of + + + align:start position:0% +changing numerator. So this is sort of +backdrop to um to how my co-author and I + + align:start position:0% +backdrop to um to how my co-author and I + + + align:start position:0% +backdrop to um to how my co-author and I +proceed. So um so there's + + align:start position:0% +proceed. So um so there's + + + align:start position:0% +proceed. So um so there's +um so again a numerator is a portfolio + + align:start position:0% +um so again a numerator is a portfolio + + + align:start position:0% +um so again a numerator is a portfolio +whose value is always strictly positive + + align:start position:0% +whose value is always strictly positive + + + align:start position:0% +whose value is always strictly positive +and um there's a a well-developed theory + + align:start position:0% +and um there's a a well-developed theory + + + align:start position:0% +and um there's a a well-developed theory +in derives pricing about how to change + + align:start position:0% +in derives pricing about how to change + + + align:start position:0% +in derives pricing about how to change +the numerator and um let's say + + align:start position:0% +the numerator and um let's say + + + align:start position:0% +the numerator and um let's say +um we're going to use that theory to + + align:start position:0% +um we're going to use that theory to + + + align:start position:0% +um we're going to use that theory to +understand what Ross did. So, we start + + align:start position:0% +understand what Ross did. So, we start + + + align:start position:0% +understand what Ross did. So, we start +with an economy with a so-called money + + align:start position:0% +with an economy with a so-called money + + + align:start position:0% +with an economy with a so-called money +market account. And so, that's a + + align:start position:0% +market account. And so, that's a + + + align:start position:0% +market account. And so, that's a +theoretical construct that's pretty + + align:start position:0% +theoretical construct that's pretty + + + align:start position:0% +theoretical construct that's pretty +familiar to to most of us. And, uh, it's + + align:start position:0% +familiar to to most of us. And, uh, it's + + + align:start position:0% +familiar to to most of us. And, uh, it's +a bank account. So, um, so we're going + + align:start position:0% +a bank account. So, um, so we're going + + + align:start position:0% +a bank account. So, um, so we're going +to be working now in continuous time. + + align:start position:0% +to be working now in continuous time. + + + align:start position:0% +to be working now in continuous time. +So, imagine that time, which is + + align:start position:0% +So, imagine that time, which is + + + align:start position:0% +So, imagine that time, which is +continuous, is on this axis. And that + + align:start position:0% +continuous, is on this axis. And that + + + align:start position:0% +continuous, is on this axis. And that +we're sitting here today, and we put + + align:start position:0% +we're sitting here today, and we put + + + align:start position:0% +we're sitting here today, and we put +some money into the bank, and being + + align:start position:0% +some money into the bank, and being + + + align:start position:0% +some money into the bank, and being +poor, we only put $1 in. So um so then + + align:start position:0% +poor, we only put $1 in. So um so then + + + align:start position:0% +poor, we only put $1 in. So um so then +we ask how will you know looking forward + + align:start position:0% +we ask how will you know looking forward + + + align:start position:0% +we ask how will you know looking forward +how will this money in our bank change? + + align:start position:0% +how will this money in our bank change? + + + align:start position:0% +how will this money in our bank change? +Well + + align:start position:0% +Well + + + align:start position:0% +Well +you know they do still pay a positive + + align:start position:0% +you know they do still pay a positive + + + align:start position:0% +you know they do still pay a positive +interest rate. It's awfully small, but + + align:start position:0% +interest rate. It's awfully small, but + + + align:start position:0% +interest rate. It's awfully small, but +it's positive. And so it'll go up and + + align:start position:0% +it's positive. And so it'll go up and + + + align:start position:0% +it's positive. And so it'll go up and +they change the rate actually, you know. + + align:start position:0% +they change the rate actually, you know. + + + align:start position:0% +they change the rate actually, you know. +So now maybe it's half a percent, but + + align:start position:0% +So now maybe it's half a percent, but + + + align:start position:0% +So now maybe it's half a percent, but +next week Chase might decide to give you + + align:start position:0% +next week Chase might decide to give you + + + align:start position:0% +next week Chase might decide to give you +1% which case it goes up faster and then + + align:start position:0% +1% which case it goes up faster and then + + + align:start position:0% +1% which case it goes up faster and then +they might the week after give you 2%, + + align:start position:0% +they might the week after give you 2%, + + + align:start position:0% +they might the week after give you 2%, +it goes up faster and they might go back + + align:start position:0% +it goes up faster and they might go back + + + align:start position:0% +it goes up faster and they might go back +to half a percent. So you know, so + + align:start position:0% +to half a percent. So you know, so + + + align:start position:0% +to half a percent. So you know, so +that's one possible path for your money + + align:start position:0% +that's one possible path for your money + + + align:start position:0% +that's one possible path for your money +market account balance. And we don't + + align:start position:0% +market account balance. And we don't + + + align:start position:0% +market account balance. And we don't +know the future. So maybe you know we + + align:start position:0% +know the future. So maybe you know we + + + align:start position:0% +know the future. So maybe you know we +know how much we're getting over this + + align:start position:0% +know how much we're getting over this + + + align:start position:0% +know how much we're getting over this +first little bit of time but they could + + align:start position:0% +first little bit of time but they could + + + align:start position:0% +first little bit of time but they could +actually decide to pay less over the + + align:start position:0% +actually decide to pay less over the + + + align:start position:0% +actually decide to pay less over the +second period and then more over the + + align:start position:0% +second period and then more over the + + + align:start position:0% +second period and then more over the +third something like that. Okay so it's + + align:start position:0% +third something like that. Okay so it's + + + align:start position:0% +third something like that. Okay so it's +increasing and it's random. Okay so + + align:start position:0% +increasing and it's random. Okay so + + + align:start position:0% +increasing and it's random. Okay so +that's the money market account balance. + + align:start position:0% +that's the money market account balance. + + + align:start position:0% +that's the money market account balance. +It's considered as an increasing + + align:start position:0% +It's considered as an increasing + + + align:start position:0% +It's considered as an increasing +random process + + align:start position:0% +random process + + + align:start position:0% +random process +and uh actually there's nothing in the + + align:start position:0% +and uh actually there's nothing in the + + + align:start position:0% +and uh actually there's nothing in the +math that requires it to be increasing + + align:start position:0% +math that requires it to be increasing + + + align:start position:0% +math that requires it to be increasing +if some really cheap bank like Bank of + + align:start position:0% +if some really cheap bank like Bank of + + + align:start position:0% +if some really cheap bank like Bank of +America tried this actually to charge a + + align:start position:0% +America tried this actually to charge a + + + align:start position:0% +America tried this actually to charge a +negative rate. Okay. Uh then it would + + align:start position:0% +negative rate. Okay. Uh then it would + + + align:start position:0% +negative rate. Okay. Uh then it would +actually go down uh with a negative + + align:start position:0% +actually go down uh with a negative + + + align:start position:0% +actually go down uh with a negative +rate, but it wouldn't go negative. So it + + align:start position:0% +rate, but it wouldn't go negative. So it + + + align:start position:0% +rate, but it wouldn't go negative. So it +still counts as a as a new rare. And um + + align:start position:0% +still counts as a as a new rare. And um + + + align:start position:0% +still counts as a as a new rare. And um +so so anyway, that's allowed as an + + align:start position:0% +so so anyway, that's allowed as an + + + align:start position:0% +so so anyway, that's allowed as an +aside. + + align:start position:0% +aside. + + + align:start position:0% +aside. +And um + + align:start position:0% +And um + + + align:start position:0% +And um +okay, so we've got this money market + + align:start position:0% +okay, so we've got this money market + + + align:start position:0% +okay, so we've got this money market +account and um + + align:start position:0% +account and um + + + align:start position:0% +account and um +so the growth rate is called R and + + align:start position:0% +so the growth rate is called R and + + + align:start position:0% +so the growth rate is called R and +that's just real valued. And then we + + align:start position:0% +that's just real valued. And then we + + + align:start position:0% +that's just real valued. And then we +also have risky assets. So we'll have a + + align:start position:0% +also have risky assets. So we'll have a + + + align:start position:0% +also have risky assets. So we'll have a +total of n risky assets. And um then um + + align:start position:0% +total of n risky assets. And um then um + + + align:start position:0% +total of n risky assets. And um then um +we're going to assume there's no + + align:start position:0% +we're going to assume there's no + + + align:start position:0% +we're going to assume there's no +arbitrage between the n risky assets and + + align:start position:0% +arbitrage between the n risky assets and + + + align:start position:0% +arbitrage between the n risky assets and +the one money market account. and that + + align:start position:0% +the one money market account. and that + + + align:start position:0% +the one money market account. and that +um when we go look at + + align:start position:0% +um when we go look at + + + align:start position:0% +um when we go look at +um that the idea is that when we look at + + align:start position:0% +um that the idea is that when we look at + + + align:start position:0% +um that the idea is that when we look at +Bloomberg's prices for these N+1 assets, + + align:start position:0% +Bloomberg's prices for these N+1 assets, + + + align:start position:0% +Bloomberg's prices for these N+1 assets, +we're able to extract these a degree + + align:start position:0% +we're able to extract these a degree + + + align:start position:0% +we're able to extract these a degree +security prices. That's the idea. And um + + align:start position:0% +security prices. That's the idea. And um + + + align:start position:0% +security prices. That's the idea. And um +let's say what I'm assuming is that uh + + align:start position:0% +let's say what I'm assuming is that uh + + + align:start position:0% +let's say what I'm assuming is that uh +what we're extracting is consistent with + + align:start position:0% +what we're extracting is consistent with + + + align:start position:0% +what we're extracting is consistent with +the idea that the uncertainty + + align:start position:0% +the idea that the uncertainty + + + align:start position:0% +the idea that the uncertainty +uh that's driving everything here is a + + align:start position:0% +uh that's driving everything here is a + + + align:start position:0% +uh that's driving everything here is a +diffusion. meaning that the uncertainty + + align:start position:0% +diffusion. meaning that the uncertainty + + + align:start position:0% +diffusion. meaning that the uncertainty +uh has sample paths + + align:start position:0% +uh has sample paths + + + align:start position:0% +uh has sample paths +that are continuous uh but they're + + align:start position:0% +that are continuous uh but they're + + + align:start position:0% +that are continuous uh but they're +allowed to be fairly jagged. So um so + + align:start position:0% +allowed to be fairly jagged. So um so + + + align:start position:0% +allowed to be fairly jagged. So um so +diffusions actually have continuous but + + align:start position:0% +diffusions actually have continuous but + + + align:start position:0% +diffusions actually have continuous but +non-ifferiable sample paths and we're + + align:start position:0% +non-ifferiable sample paths and we're + + + align:start position:0% +non-ifferiable sample paths and we're +going to assume that so um this is a + + align:start position:0% +going to assume that so um this is a + + + align:start position:0% +going to assume that so um this is a +common assumption. This is uh basically + + align:start position:0% +common assumption. This is uh basically + + + align:start position:0% +common assumption. This is uh basically +got its start here at MIT + + align:start position:0% +got its start here at MIT + + + align:start position:0% +got its start here at MIT +and um I'd say diffusions were first + + align:start position:0% +and um I'd say diffusions were first + + + align:start position:0% +and um I'd say diffusions were first +used in a finance context back in 1965 + + align:start position:0% +used in a finance context back in 1965 + + + align:start position:0% +used in a finance context back in 1965 +when both Samuelson and McKeen were + + align:start position:0% +when both Samuelson and McKeen were + + + align:start position:0% +when both Samuelson and McKeen were +here. So Mckeen is a probabilist who's + + align:start position:0% +here. So Mckeen is a probabilist who's + + + align:start position:0% +here. So Mckeen is a probabilist who's +now at NYU where I teach and um he's + + align:start position:0% +now at NYU where I teach and um he's + + + align:start position:0% +now at NYU where I teach and um he's +still active. And um anyway uh + + align:start position:0% +still active. And um anyway uh + + + align:start position:0% +still active. And um anyway uh +diffusions are widely used. So they they + + align:start position:0% +diffusions are widely used. So they they + + + align:start position:0% +diffusions are widely used. So they they +really got a big boost in 1973 when + + align:start position:0% +really got a big boost in 1973 when + + + align:start position:0% +really got a big boost in 1973 when +Black Scholes and Merin who were all + + align:start position:0% +Black Scholes and Merin who were all + + + align:start position:0% +Black Scholes and Merin who were all +here uh used the diffusion to describe + + align:start position:0% +here uh used the diffusion to describe + + + align:start position:0% +here uh used the diffusion to describe +the price of a stock underlying an + + align:start position:0% +the price of a stock underlying an + + + align:start position:0% +the price of a stock underlying an +option and um since then they've just + + align:start position:0% +option and um since then they've just + + + align:start position:0% +option and um since then they've just +been used extensively in finance. So um + + align:start position:0% +been used extensively in finance. So um + + + align:start position:0% +been used extensively in finance. So um +Merin who's here really um I'd say + + align:start position:0% +Merin who's here really um I'd say + + + align:start position:0% +Merin who's here really um I'd say +pioneered the use of them in finance. + + align:start position:0% +pioneered the use of them in finance. + + + align:start position:0% +pioneered the use of them in finance. +So um + + align:start position:0% +So um + + + align:start position:0% +So um +okay so um + + align:start position:0% +okay so um + + + align:start position:0% +okay so um +okay + + align:start position:0% +okay + + + align:start position:0% +okay +well so um + + align:start position:0% +well so um + + + align:start position:0% +well so um +so there's this this uncertainty X is + + align:start position:0% +so there's this this uncertainty X is + + + align:start position:0% +so there's this this uncertainty X is +probably mysterious to you hence the + + align:start position:0% +probably mysterious to you hence the + + + align:start position:0% +probably mysterious to you hence the +name X and uh so uh so it's like you get + + align:start position:0% +name X and uh so uh so it's like you get + + + align:start position:0% +name X and uh so uh so it's like you get +to choose what it is is kind of the idea + + align:start position:0% +to choose what it is is kind of the idea + + + align:start position:0% +to choose what it is is kind of the idea +so this is theory and um it's not trying + + align:start position:0% +so this is theory and um it's not trying + + + align:start position:0% +so this is theory and um it's not trying +to be overly specific specific so that + + align:start position:0% +to be overly specific specific so that + + + align:start position:0% +to be overly specific specific so that +you can apply it in different contexts + + align:start position:0% +you can apply it in different contexts + + + align:start position:0% +you can apply it in different contexts +and um but you'd like to know at least + + align:start position:0% +and um but you'd like to know at least + + + align:start position:0% +and um but you'd like to know at least +some examples I'm sure so one example + + align:start position:0% +some examples I'm sure so one example + + + align:start position:0% +some examples I'm sure so one example +would be X is the is the level of S&P + + align:start position:0% +would be X is the is the level of S&P + + + align:start position:0% +would be X is the is the level of S&P +500 a different example would be X is is + + align:start position:0% +500 a different example would be X is is + + + align:start position:0% +500 a different example would be X is is +is actually an interest rate okay so um + + align:start position:0% +is actually an interest rate okay so um + + + align:start position:0% +is actually an interest rate okay so um +let's say the benchmark 30-year yield um + + align:start position:0% +let's say the benchmark 30-year yield um + + + align:start position:0% +let's say the benchmark 30-year yield um +it could in X could instead be a shorter + + align:start position:0% +it could in X could instead be a shorter + + + align:start position:0% +it could in X could instead be a shorter +term interest rate something called OIS + + align:start position:0% +term interest rate something called OIS + + + align:start position:0% +term interest rate something called OIS +overnight index uh swap top is um is a + + align:start position:0% +overnight index uh swap top is um is a + + + align:start position:0% +overnight index uh swap top is um is a +is a possible choice for X and um let's + + align:start position:0% +is a possible choice for X and um let's + + + align:start position:0% +is a possible choice for X and um let's +say when I apply RAS's stuff that's how + + align:start position:0% +say when I apply RAS's stuff that's how + + + align:start position:0% +say when I apply RAS's stuff that's how +I choose X as a short interest rate the + + align:start position:0% +I choose X as a short interest rate the + + + align:start position:0% +I choose X as a short interest rate the +short-term interest rate so um so let's + + align:start position:0% +short-term interest rate so um so let's + + + align:start position:0% +short-term interest rate so um so let's +say so in general let's say I developed + + align:start position:0% +say so in general let's say I developed + + + align:start position:0% +say so in general let's say I developed +a theory that says the short rate is + + align:start position:0% +a theory that says the short rate is + + + align:start position:0% +a theory that says the short rate is +some function of X and when I actually + + align:start position:0% +some function of X and when I actually + + + align:start position:0% +some function of X and when I actually +apply it the function is the identity + + align:start position:0% +apply it the function is the identity + + + align:start position:0% +apply it the function is the identity +map so um okay So, + + align:start position:0% + + + + align:start position:0% + +so anyway the + + align:start position:0% +so anyway the + + + align:start position:0% +so anyway the +um the mathematics says that + + align:start position:0% +um the mathematics says that + + + align:start position:0% +um the mathematics says that +okay so if there's no arbitrage then + + align:start position:0% +okay so if there's no arbitrage then + + + align:start position:0% +okay so if there's no arbitrage then +there exists as we're assuming then + + align:start position:0% +there exists as we're assuming then + + + align:start position:0% +there exists as we're assuming then +there exists this so-called risk neutral + + align:start position:0% +there exists this so-called risk neutral + + + align:start position:0% +there exists this so-called risk neutral +probability measure that I talked about + + align:start position:0% +probability measure that I talked about + + + align:start position:0% +probability measure that I talked about +earlier and um denoted by Q it's related + + align:start position:0% +earlier and um denoted by Q it's related + + + align:start position:0% +earlier and um denoted by Q it's related +but not equal to the area to security + + align:start position:0% +but not equal to the area to security + + + align:start position:0% +but not equal to the area to security +prices so the if you were to just + + align:start position:0% +prices so the if you were to just + + + align:start position:0% +prices so the if you were to just +imagine that instead of buying these + + align:start position:0% +imagine that instead of buying these + + + align:start position:0% +imagine that instead of buying these +aerody security prices in a spot market + + align:start position:0% +aerody security prices in a spot market + + + align:start position:0% +aerody security prices in a spot market +if you instead bought them in a forward + + align:start position:0% +if you instead bought them in a forward + + + align:start position:0% +if you instead bought them in a forward +market where you actually pay when they + + align:start position:0% +market where you actually pay when they + + + align:start position:0% +market where you actually pay when they +mature uh then those aerody security + + align:start position:0% +mature uh then those aerody security + + + align:start position:0% +mature uh then those aerody security +prices in the forward market would be Q + + align:start position:0% +prices in the forward market would be Q + + + align:start position:0% +prices in the forward market would be Q +okay so Q and A are really close uh so A + + align:start position:0% +okay so Q and A are really close uh so A + + + align:start position:0% +okay so Q and A are really close uh so A +the measure A need not integrate to one + + align:start position:0% +the measure A need not integrate to one + + + align:start position:0% +the measure A need not integrate to one +and that's just just through time value + + align:start position:0% +and that's just just through time value + + + align:start position:0% +and that's just just through time value +of money and that's because you're + + align:start position:0% +of money and that's because you're + + + align:start position:0% +of money and that's because you're +paying in the spot market if you're + + align:start position:0% +paying in the spot market if you're + + + align:start position:0% +paying in the spot market if you're +actually paying in the forward market + + align:start position:0% +actually paying in the forward market + + + align:start position:0% +actually paying in the forward market +then you don't have to worry about time + + align:start position:0% +then you don't have to worry about time + + + align:start position:0% +then you don't have to worry about time +value of Okay. And so then uh the + + align:start position:0% +value of Okay. And so then uh the + + + align:start position:0% +value of Okay. And so then uh the +measure Q does integrate to one. So + + align:start position:0% +measure Q does integrate to one. So + + + align:start position:0% +measure Q does integrate to one. So +that's why we call it a probability + + align:start position:0% +that's why we call it a probability + + + align:start position:0% +that's why we call it a probability +measure. + + align:start position:0% + + + + align:start position:0% + +Okay. And under this probability measure + + align:start position:0% +Okay. And under this probability measure + + + align:start position:0% +Okay. And under this probability measure +Q, the expected return on all assets is + + align:start position:0% +Q, the expected return on all assets is + + + align:start position:0% +Q, the expected return on all assets is +the risk-free rate. So that's what that + + align:start position:0% +the risk-free rate. So that's what that + + + align:start position:0% +the risk-free rate. So that's what that +actually says. Although you're probably + + align:start position:0% +actually says. Although you're probably + + + align:start position:0% +actually says. Although you're probably +not seeing that this is literally the + + align:start position:0% +not seeing that this is literally the + + + align:start position:0% +not seeing that this is literally the +expected return. Well, it's more + + align:start position:0% +expected return. Well, it's more + + + align:start position:0% +expected return. Well, it's more +precisely it's expected price change. So + + align:start position:0% +precisely it's expected price change. So + + + align:start position:0% +precisely it's expected price change. So +the expected price change is that what + + align:start position:0% +the expected price change is that what + + + align:start position:0% +the expected price change is that what +that means. And so it says the expected + + align:start position:0% +that means. And so it says the expected + + + align:start position:0% +that means. And so it says the expected +price change is equal to risk free rate + + align:start position:0% +price change is equal to risk free rate + + + align:start position:0% +price change is equal to risk free rate +times the price. That's what that says. + + align:start position:0% +times the price. That's what that says. + + + align:start position:0% +times the price. That's what that says. +So so if you divide both sides by the + + align:start position:0% +So so if you divide both sides by the + + + align:start position:0% +So so if you divide both sides by the +spot price when it's positive, then + + align:start position:0% +spot price when it's positive, then + + + align:start position:0% +spot price when it's positive, then +you'll get that the expected return is + + align:start position:0% +you'll get that the expected return is + + + align:start position:0% +you'll get that the expected return is +equal to risk-free rate. And uh we're + + align:start position:0% +equal to risk-free rate. And uh we're + + + align:start position:0% +equal to risk-free rate. And uh we're +doing things in continuous time here. So + + align:start position:0% +doing things in continuous time here. So + + + align:start position:0% +doing things in continuous time here. So +we're working with diffusions. And um + + align:start position:0% +we're working with diffusions. And um + + + align:start position:0% +we're working with diffusions. And um +you may or may not have been introduced + + align:start position:0% +you may or may not have been introduced + + + align:start position:0% +you may or may not have been introduced +to diffusions at this stage in your + + align:start position:0% +to diffusions at this stage in your + + + align:start position:0% +to diffusions at this stage in your +mathematical career, but mathematically + + align:start position:0% +mathematical career, but mathematically + + + align:start position:0% +mathematical career, but mathematically +one way to describe diffusions is via + + align:start position:0% +one way to describe diffusions is via + + + align:start position:0% +one way to describe diffusions is via +the the infantessimal generator. So um + + align:start position:0% +the the infantessimal generator. So um + + + align:start position:0% +the the infantessimal generator. So um +this is a differential operator that's + + align:start position:0% +this is a differential operator that's + + + align:start position:0% +this is a differential operator that's +um first order in time and second order + + align:start position:0% +um first order in time and second order + + + align:start position:0% +um first order in time and second order +in space. And let's just say this is + + align:start position:0% +in space. And let's just say this is + + + align:start position:0% +in space. And let's just say this is +formally how mathematicians think about + + align:start position:0% +formally how mathematicians think about + + + align:start position:0% +formally how mathematicians think about +this type of thing. You say this is what + + align:start position:0% +this type of thing. You say this is what + + + align:start position:0% +this type of thing. You say this is what +I've drawn here is a single sample path + + align:start position:0% +I've drawn here is a single sample path + + + align:start position:0% +I've drawn here is a single sample path +of a diffusion. There's definitely + + align:start position:0% +of a diffusion. There's definitely + + + align:start position:0% +of a diffusion. There's definitely +possibility of other sample paths. + + align:start position:0% +possibility of other sample paths. + + + align:start position:0% +possibility of other sample paths. +There's actually an infinite number of + + align:start position:0% +There's actually an infinite number of + + + align:start position:0% +There's actually an infinite number of +paths but they're all continuous and + + align:start position:0% +paths but they're all continuous and + + + align:start position:0% +paths but they're all continuous and +infinitely non they're continuous and + + align:start position:0% +infinitely non they're continuous and + + + align:start position:0% +infinitely non they're continuous and +nowhere differentiable. + + align:start position:0% +nowhere differentiable. + + + align:start position:0% +nowhere differentiable. +So um + + align:start position:0% + + + + align:start position:0% + +okay now um the um I think okay so + + align:start position:0% +okay now um the um I think okay so + + + align:start position:0% +okay now um the um I think okay so +so um + + align:start position:0% +so um + + + align:start position:0% +so um +I want to just kind of give you a flavor + + align:start position:0% +I want to just kind of give you a flavor + + + align:start position:0% +I want to just kind of give you a flavor +of how you change numer + + align:start position:0% +of how you change numer + + + align:start position:0% +of how you change numer +um so we've started with the numerator + + align:start position:0% +um so we've started with the numerator + + + align:start position:0% +um so we've started with the numerator +being the money market account this guy + + align:start position:0% +being the money market account this guy + + + align:start position:0% +being the money market account this guy +and the idea is we're going to switch to + + align:start position:0% +and the idea is we're going to switch to + + + align:start position:0% +and the idea is we're going to switch to +a different numer rare. Uh and so um + + align:start position:0% +a different numer rare. Uh and so um + + + align:start position:0% +a different numer rare. Uh and so um +what'll what we're mainly interested in + + align:start position:0% +what'll what we're mainly interested in + + + align:start position:0% +what'll what we're mainly interested in +figuring out is what are the drifts of + + align:start position:0% +figuring out is what are the drifts of + + + align:start position:0% +figuring out is what are the drifts of +assets + + align:start position:0% +assets + + + align:start position:0% +assets +when + + align:start position:0% +when + + + align:start position:0% +when +we uh + + align:start position:0% +we uh + + + align:start position:0% +we uh +when we + + align:start position:0% +when we + + + align:start position:0% +when we +measure them we measure their uh their + + align:start position:0% +measure them we measure their uh their + + + align:start position:0% +measure them we measure their uh their +values in a different numerator. So I'll + + align:start position:0% +values in a different numerator. So I'll + + + align:start position:0% +values in a different numerator. So I'll +kind of give you a sense of what this is + + align:start position:0% +kind of give you a sense of what this is + + + align:start position:0% +kind of give you a sense of what this is +about. So, so you could hold IBM + + align:start position:0% +about. So, so you could hold IBM + + + align:start position:0% +about. So, so you could hold IBM +and um every time you get a gain, you + + align:start position:0% +and um every time you get a gain, you + + + align:start position:0% +and um every time you get a gain, you +could put that gain in your local bank, + + align:start position:0% +could put that gain in your local bank, + + + align:start position:0% +could put that gain in your local bank, +Chase, and see uh how fast your bank + + align:start position:0% +Chase, and see uh how fast your bank + + + align:start position:0% +Chase, and see uh how fast your bank +balance grows as you're putting all your + + align:start position:0% +balance grows as you're putting all your + + + align:start position:0% +balance grows as you're putting all your +gains in IBM in the bank, and you'll get + + align:start position:0% +gains in IBM in the bank, and you'll get + + + align:start position:0% +gains in IBM in the bank, and you'll get +a certain growth rate + + align:start position:0% +a certain growth rate + + + align:start position:0% +a certain growth rate +um from that strategy. Now, you could + + align:start position:0% +um from that strategy. Now, you could + + + align:start position:0% +um from that strategy. Now, you could +try a different strategy where you take + + align:start position:0% +try a different strategy where you take + + + align:start position:0% +try a different strategy where you take +your gains from IBM and you actually + + align:start position:0% +your gains from IBM and you actually + + + align:start position:0% +your gains from IBM and you actually +ship them off over to a British bank, + + align:start position:0% +ship them off over to a British bank, + + + align:start position:0% +ship them off over to a British bank, +okay, which is nominated in pounds and + + align:start position:0% +okay, which is nominated in pounds and + + + align:start position:0% +okay, which is nominated in pounds and +uh see how fast that bank balance grows. + + align:start position:0% +uh see how fast that bank balance grows. + + + align:start position:0% +uh see how fast that bank balance grows. +And there's no reason that the two bank + + align:start position:0% +And there's no reason that the two bank + + + align:start position:0% +And there's no reason that the two bank +balances, the American one and the + + align:start position:0% +balances, the American one and the + + + align:start position:0% +balances, the American one and the +British one need to grow at the same + + align:start position:0% +British one need to grow at the same + + + align:start position:0% +British one need to grow at the same +rate because they're denominated + + align:start position:0% +rate because they're denominated + + + align:start position:0% +rate because they're denominated +different currencies. So um so we're + + align:start position:0% +different currencies. So um so we're + + + align:start position:0% +different currencies. So um so we're +basically interested to know given that + + align:start position:0% +basically interested to know given that + + + align:start position:0% +basically interested to know given that +we know how fast let's say the American + + align:start position:0% +we know how fast let's say the American + + + align:start position:0% +we know how fast let's say the American +bank balance would grow. We want to know + + align:start position:0% +bank balance would grow. We want to know + + + align:start position:0% +bank balance would grow. We want to know +how fast the British bank balance would + + align:start position:0% +how fast the British bank balance would + + + align:start position:0% +how fast the British bank balance would +grow. And what affects the growth rate + + align:start position:0% +grow. And what affects the growth rate + + + align:start position:0% +grow. And what affects the growth rate +of the British bank balance is the + + align:start position:0% +of the British bank balance is the + + + align:start position:0% +of the British bank balance is the +covariance actually between the dollar + + align:start position:0% +covariance actually between the dollar + + + align:start position:0% +covariance actually between the dollar +pound exchange rate and IBM. Okay. So, + + align:start position:0% +pound exchange rate and IBM. Okay. So, + + + align:start position:0% +pound exchange rate and IBM. Okay. So, +so remember we're investing in IBM and + + align:start position:0% +so remember we're investing in IBM and + + + align:start position:0% +so remember we're investing in IBM and +we're putting gains in either an + + align:start position:0% +we're putting gains in either an + + + align:start position:0% +we're putting gains in either an +American bank or a British bank. So, IBM + + align:start position:0% +American bank or a British bank. So, IBM + + + align:start position:0% +American bank or a British bank. So, IBM +stock prices is in dollars. And so, + + align:start position:0% +stock prices is in dollars. And so, + + + align:start position:0% +stock prices is in dollars. And so, +there's no issues with putting IBM's + + align:start position:0% +there's no issues with putting IBM's + + + align:start position:0% +there's no issues with putting IBM's +gains in an American bank. Uh, but + + align:start position:0% +gains in an American bank. Uh, but + + + align:start position:0% +gains in an American bank. Uh, but +there's actually a subtle effect that + + align:start position:0% +there's actually a subtle effect that + + + align:start position:0% +there's actually a subtle effect that +happens when you put IBM's gains in a + + align:start position:0% +happens when you put IBM's gains in a + + + align:start position:0% +happens when you put IBM's gains in a +British bank, which the subtle effect is + + align:start position:0% +British bank, which the subtle effect is + + + align:start position:0% +British bank, which the subtle effect is +there's this random exchange rate, + + align:start position:0% +there's this random exchange rate, + + + align:start position:0% +there's this random exchange rate, +dollars per pound. And um suppose that + + align:start position:0% +dollars per pound. And um suppose that + + + align:start position:0% +dollars per pound. And um suppose that +there's some correlation between for + + align:start position:0% +there's some correlation between for + + + align:start position:0% +there's some correlation between for +whatever reason between um dollars per + + align:start position:0% +whatever reason between um dollars per + + + align:start position:0% +whatever reason between um dollars per +pound and IBM. Okay. So suppose the + + align:start position:0% +pound and IBM. Okay. So suppose the + + + align:start position:0% +pound and IBM. Okay. So suppose the +correlation is the following form. Uh + + align:start position:0% +correlation is the following form. Uh + + + align:start position:0% +correlation is the following form. Uh +every time IBM goes up, the dollar gets + + align:start position:0% +every time IBM goes up, the dollar gets + + + align:start position:0% +every time IBM goes up, the dollar gets +weaker against the pound. So um so in + + align:start position:0% +weaker against the pound. So um so in + + + align:start position:0% +weaker against the pound. So um so in +other words, what happens is IBM goes up + + align:start position:0% +other words, what happens is IBM goes up + + + align:start position:0% +other words, what happens is IBM goes up +and you go, "Hooray, I'm rich. I got all + + align:start position:0% +and you go, "Hooray, I'm rich. I got all + + + align:start position:0% +and you go, "Hooray, I'm rich. I got all +these dollars. I'm going to go um put + + align:start position:0% +these dollars. I'm going to go um put + + + align:start position:0% +these dollars. I'm going to go um put +them in a British bank account." So then + + align:start position:0% +them in a British bank account." So then + + + align:start position:0% +them in a British bank account." So then +um the um but suppose unluckily for you + + align:start position:0% +um the um but suppose unluckily for you + + + align:start position:0% +um the um but suppose unluckily for you +every time IBM goes up the dollar + + align:start position:0% +every time IBM goes up the dollar + + + align:start position:0% +every time IBM goes up the dollar +weakens against the pound and so um you + + align:start position:0% +weakens against the pound and so um you + + + align:start position:0% +weakens against the pound and so um you +can't buy so many you cannot buy so many + + align:start position:0% +can't buy so many you cannot buy so many + + + align:start position:0% +can't buy so many you cannot buy so many +pounds uh as a result. Okay so um so + + align:start position:0% +pounds uh as a result. Okay so um so + + + align:start position:0% +pounds uh as a result. Okay so um so +contrast that with the opposite + + align:start position:0% +contrast that with the opposite + + + align:start position:0% +contrast that with the opposite +situation where when IBM goes up the + + align:start position:0% +situation where when IBM goes up the + + + align:start position:0% +situation where when IBM goes up the +dollar strengthens as opposed to + + align:start position:0% +dollar strengthens as opposed to + + + align:start position:0% +dollar strengthens as opposed to +weakens. Okay then you can buy lots and + + align:start position:0% +weakens. Okay then you can buy lots and + + + align:start position:0% +weakens. Okay then you can buy lots and +lots of pounds with your IBM gains. So, + + align:start position:0% +lots of pounds with your IBM gains. So, + + + align:start position:0% +lots of pounds with your IBM gains. So, +so those um so the correlation between + + align:start position:0% +so those um so the correlation between + + + align:start position:0% +so those um so the correlation between +the dollar pound exchange rate and IBM + + align:start position:0% +the dollar pound exchange rate and IBM + + + align:start position:0% +the dollar pound exchange rate and IBM +affects how fast your British bank + + align:start position:0% +affects how fast your British bank + + + align:start position:0% +affects how fast your British bank +balance would grow and um that's + + align:start position:0% +balance would grow and um that's + + + align:start position:0% +balance would grow and um that's +actually like the key point. So, so what + + align:start position:0% +actually like the key point. So, so what + + + align:start position:0% +actually like the key point. So, so what +um is going to happen here? + + align:start position:0% +um is going to happen here? + + + align:start position:0% +um is going to happen here? +So this would be well known anybody + + align:start position:0% +So this would be well known anybody + + + align:start position:0% +So this would be well known anybody +who's is you know especially an FXQ + + align:start position:0% +who's is you know especially an FXQ + + + align:start position:0% +who's is you know especially an FXQ +quant and uh and so um so what we're + + align:start position:0% +quant and uh and so um so what we're + + + align:start position:0% +quant and uh and so um so what we're +actually going to do is um + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +find a numerator such that the growth + + align:start position:0% +find a numerator such that the growth + + + align:start position:0% +find a numerator such that the growth +rate of the balance in that numerator is + + align:start position:0% +rate of the balance in that numerator is + + + align:start position:0% +rate of the balance in that numerator is +the real world is actually the real + + align:start position:0% +the real world is actually the real + + + align:start position:0% +the real world is actually the real +world drift of the underlying. Okay. So + + align:start position:0% +world drift of the underlying. Okay. So + + + align:start position:0% +world drift of the underlying. Okay. So +um so the idea is + + align:start position:0% +um so the idea is + + + align:start position:0% +um so the idea is +let's say like I told you at the + + align:start position:0% +let's say like I told you at the + + + align:start position:0% +let's say like I told you at the +beginning of this talk that historically + + align:start position:0% +beginning of this talk that historically + + + align:start position:0% +beginning of this talk that historically +stocks grow at 9% on average. Okay. And + + align:start position:0% +stocks grow at 9% on average. Okay. And + + + align:start position:0% +stocks grow at 9% on average. Okay. And +um that the our starting point here in + + align:start position:0% +um that the our starting point here in + + + align:start position:0% +um that the our starting point here in +this part of the talk is that we're + + align:start position:0% +this part of the talk is that we're + + + align:start position:0% +this part of the talk is that we're +starting from uh this risk neutral + + align:start position:0% +starting from uh this risk neutral + + + align:start position:0% +starting from uh this risk neutral +measure Q which by definition is the + + align:start position:0% +measure Q which by definition is the + + + align:start position:0% +measure Q which by definition is the +property that stocks would grow only at + + align:start position:0% +property that stocks would grow only at + + + align:start position:0% +property that stocks would grow only at +1%. So um so what we're actually going + + align:start position:0% +1%. So um so what we're actually going + + + align:start position:0% +1%. So um so what we're actually going +to do is go find + + align:start position:0% +to do is go find + + + align:start position:0% +to do is go find +some numerator + + align:start position:0% +some numerator + + + align:start position:0% +some numerator +which will be correlated with the stocks + + align:start position:0% +which will be correlated with the stocks + + + align:start position:0% +which will be correlated with the stocks +such that when we um put when we put our + + align:start position:0% +such that when we um put when we put our + + + align:start position:0% +such that when we um put when we put our +stock gains in that numerator + + align:start position:0% +stock gains in that numerator + + + align:start position:0% +stock gains in that numerator +we end up growing at 9% rather than 1%. + + align:start position:0% +we end up growing at 9% rather than 1%. + + + align:start position:0% +we end up growing at 9% rather than 1%. +Okay. So, + + align:start position:0% +Okay. So, + + + align:start position:0% +Okay. So, +so that's the that's kind of the the way + + align:start position:0% +so that's the that's kind of the the way + + + align:start position:0% +so that's the that's kind of the the way +we think about things + + align:start position:0% +we think about things + + + align:start position:0% +we think about things +and the key is to find that numerator + + align:start position:0% +and the key is to find that numerator + + + align:start position:0% +and the key is to find that numerator +that has that property. So, there's a + + align:start position:0% +that has that property. So, there's a + + + align:start position:0% +that has that property. So, there's a +paper by John Long, I'm going to go fast + + align:start position:0% +paper by John Long, I'm going to go fast + + + align:start position:0% +paper by John Long, I'm going to go fast +now. There's a paper by John Long where + + align:start position:0% +now. There's a paper by John Long where + + + align:start position:0% +now. There's a paper by John Long where +he shows that that that + + align:start position:0% +he shows that that that + + + align:start position:0% +he shows that that that +numer that converts a risk-free growth + + align:start position:0% +numer that converts a risk-free growth + + + align:start position:0% +numer that converts a risk-free growth +rate into the real world growth rate + + align:start position:0% +rate into the real world growth rate + + + align:start position:0% +rate into the real world growth rate +always exists. and he gave it a name and + + align:start position:0% +always exists. and he gave it a name and + + + align:start position:0% +always exists. and he gave it a name and +he called it the numerator portfolio. It + + align:start position:0% +he called it the numerator portfolio. It + + + align:start position:0% +he called it the numerator portfolio. It +has another name, growth optimal + + align:start position:0% +has another name, growth optimal + + + align:start position:0% +has another name, growth optimal +portfolio that Kelly was talking about. + + align:start position:0% +portfolio that Kelly was talking about. + + + align:start position:0% +portfolio that Kelly was talking about. +And um so + + align:start position:0% +And um so + + + align:start position:0% +And um so +um so anyway, + + align:start position:0% + + + + align:start position:0% + +so that's um so there's you know a + + align:start position:0% +so that's um so there's you know a + + + align:start position:0% +so that's um so there's you know a +reference if you're interested in + + align:start position:0% +reference if you're interested in + + + align:start position:0% +reference if you're interested in +following up on on this on this + + align:start position:0% +following up on on this on this + + + align:start position:0% +following up on on this on this +material. So um + + align:start position:0% +material. So um + + + align:start position:0% +material. So um +so the + + align:start position:0% +so the + + + align:start position:0% +so the +um the theory says that there always + + align:start position:0% +um the theory says that there always + + + align:start position:0% +um the theory says that there always +exists this numerator called John Long's + + align:start position:0% +exists this numerator called John Long's + + + align:start position:0% +exists this numerator called John Long's +numerator portfolio such that if you + + align:start position:0% +numerator portfolio such that if you + + + align:start position:0% +numerator portfolio such that if you +park your gains in this numerator you + + align:start position:0% +park your gains in this numerator you + + + align:start position:0% +park your gains in this numerator you +end up growing + + align:start position:0% +end up growing + + + align:start position:0% +end up growing +at the real world drift and um so let's + + align:start position:0% +at the real world drift and um so let's + + + align:start position:0% +at the real world drift and um so let's +say all we got to do to find that real + + align:start position:0% +say all we got to do to find that real + + + align:start position:0% +say all we got to do to find that real +world drift is go find this numerator + + align:start position:0% +world drift is go find this numerator + + + align:start position:0% +world drift is go find this numerator +okay this special numerator and + + align:start position:0% + + + + align:start position:0% + +So this part of the talk is about making + + align:start position:0% +So this part of the talk is about making + + + align:start position:0% +So this part of the talk is about making +some assumptions that lead to an + + align:start position:0% +some assumptions that lead to an + + + align:start position:0% +some assumptions that lead to an +identification of that particular + + align:start position:0% +identification of that particular + + + align:start position:0% +identification of that particular +numerator John Long's numerator. + + align:start position:0% +numerator John Long's numerator. + + + align:start position:0% +numerator John Long's numerator. +So + + align:start position:0% +So + + + align:start position:0% +So +um so the um we're going to continue to + + align:start position:0% +um so the um we're going to continue to + + + align:start position:0% +um so the um we're going to continue to +work with diffusions and now we're going + + align:start position:0% +work with diffusions and now we're going + + + align:start position:0% +work with diffusions and now we're going +to + + align:start position:0% +to + + + align:start position:0% +to +um also impose time homogeneity like + + align:start position:0% +um also impose time homogeneity like + + + align:start position:0% +um also impose time homogeneity like +Ross was doing. So let's say when I was + + align:start position:0% +Ross was doing. So let's say when I was + + + align:start position:0% +Ross was doing. So let's say when I was +just talking about numerators I was + + align:start position:0% +just talking about numerators I was + + + align:start position:0% +just talking about numerators I was +allowing time inhomogeneity but now uh + + align:start position:0% +allowing time inhomogeneity but now uh + + + align:start position:0% +allowing time inhomogeneity but now uh +we're going to go time homogeneous. So + + align:start position:0% +we're going to go time homogeneous. So + + + align:start position:0% +we're going to go time homogeneous. So +so I haven't really been introducing the + + align:start position:0% +so I haven't really been introducing the + + + align:start position:0% +so I haven't really been introducing the +notation but axt is the diffusion + + align:start position:0% +notation but axt is the diffusion + + + align:start position:0% +notation but axt is the diffusion +coefficient of the state variable x and + + align:start position:0% +coefficient of the state variable x and + + + align:start position:0% +coefficient of the state variable x and +now it's just being assumed to be a + + align:start position:0% +now it's just being assumed to be a + + + align:start position:0% +now it's just being assumed to be a +function of x only. So bqxt was the + + align:start position:0% +function of x only. So bqxt was the + + + align:start position:0% +function of x only. So bqxt was the +drift coefficient of x and now it's a + + align:start position:0% +drift coefficient of x and now it's a + + + align:start position:0% +drift coefficient of x and now it's a +function of x only. RXT was a function + + align:start position:0% +function of x only. RXT was a function + + + align:start position:0% +function of x only. RXT was a function +linking the short interest rate to the + + align:start position:0% +linking the short interest rate to the + + + align:start position:0% +linking the short interest rate to the +state variable X and now it's a function + + align:start position:0% +state variable X and now it's a function + + + align:start position:0% +state variable X and now it's a function +of X only and finally sigma LXT was the + + align:start position:0% +of X only and finally sigma LXT was the + + + align:start position:0% +of X only and finally sigma LXT was the +volatility of John Long's numeric + + align:start position:0% +volatility of John Long's numeric + + + align:start position:0% +volatility of John Long's numeric +portfolio and again that's a function of + + align:start position:0% +portfolio and again that's a function of + + + align:start position:0% +portfolio and again that's a function of +X only. So, + + align:start position:0% +X only. So, + + + align:start position:0% +X only. So, +so anyway, another assumption that we're + + align:start position:0% +so anyway, another assumption that we're + + + align:start position:0% +so anyway, another assumption that we're +going to impose now in order to + + align:start position:0% +going to impose now in order to + + + align:start position:0% +going to impose now in order to +determine this uniquely what this + + align:start position:0% +determine this uniquely what this + + + align:start position:0% +determine this uniquely what this +numeric portfolio value is is to require + + align:start position:0% +numeric portfolio value is is to require + + + align:start position:0% +numeric portfolio value is is to require +that the diffusion that's driving + + align:start position:0% +that the diffusion that's driving + + + align:start position:0% +that the diffusion that's driving +everything live in a bounded interval. + + align:start position:0% +everything live in a bounded interval. + + + align:start position:0% +everything live in a bounded interval. +So, essentially, + + align:start position:0% +So, essentially, + + + align:start position:0% +So, essentially, +you know, the uh sample paths all have + + align:start position:0% +you know, the uh sample paths all have + + + align:start position:0% +you know, the uh sample paths all have +to be bounded below by some constant + + align:start position:0% +to be bounded below by some constant + + + align:start position:0% +to be bounded below by some constant +which could be negative and have to be + + align:start position:0% +which could be negative and have to be + + + align:start position:0% +which could be negative and have to be +bounded above by some constant which + + align:start position:0% +bounded above by some constant which + + + align:start position:0% +bounded above by some constant which +again could be negative. Okay. So, and + + align:start position:0% +again could be negative. Okay. So, and + + + align:start position:0% +again could be negative. Okay. So, and +um so then um we make all those + + align:start position:0% +um so then um we make all those + + + align:start position:0% +um so then um we make all those +assumptions and we move on. And so in + + align:start position:0% +assumptions and we move on. And so in + + + align:start position:0% +assumptions and we move on. And so in +the end, what have we been assuming? So + + align:start position:0% +the end, what have we been assuming? So + + + align:start position:0% +the end, what have we been assuming? So +we're assuming that there's a single + + align:start position:0% +we're assuming that there's a single + + + align:start position:0% +we're assuming that there's a single +source of uncertainty X and that it's a + + align:start position:0% +source of uncertainty X and that it's a + + + align:start position:0% +source of uncertainty X and that it's a +time homogeneous diffusion. So that's + + align:start position:0% +time homogeneous diffusion. So that's + + + align:start position:0% +time homogeneous diffusion. So that's +this middle equation here. And so that + + align:start position:0% +this middle equation here. And so that + + + align:start position:0% +this middle equation here. And so that +says changes in X have a predictable + + align:start position:0% +says changes in X have a predictable + + + align:start position:0% +says changes in X have a predictable +part which is BQX DT and they have an + + align:start position:0% +part which is BQX DT and they have an + + + align:start position:0% +part which is BQX DT and they have an +unpredictable part which is A of XDW. So + + align:start position:0% +unpredictable part which is A of XDW. So + + + align:start position:0% +unpredictable part which is A of XDW. So +W there is standard brand emotion. Uh + + align:start position:0% +W there is standard brand emotion. Uh + + + align:start position:0% +W there is standard brand emotion. Uh +and since you know I'm big on + + align:start position:0% +and since you know I'm big on + + + align:start position:0% +and since you know I'm big on +pneumonics, you might ask why does W + + align:start position:0% +pneumonics, you might ask why does W + + + align:start position:0% +pneumonics, you might ask why does W +stand for standard brand emotion? And + + align:start position:0% +stand for standard brand emotion? And + + + align:start position:0% +stand for standard brand emotion? And +that's because W actually stands for + + align:start position:0% +that's because W actually stands for + + + align:start position:0% +that's because W actually stands for +Weiner process. Norbert Weiner being an + + align:start position:0% +Weiner process. Norbert Weiner being an + + + align:start position:0% +Weiner process. Norbert Weiner being an +MIT mathematician. Okay. So um so anyway + + align:start position:0% +MIT mathematician. Okay. So um so anyway + + + align:start position:0% +MIT mathematician. Okay. So um so anyway +uh and the W is a standard notation for + + align:start position:0% +uh and the W is a standard notation for + + + align:start position:0% +uh and the W is a standard notation for +this kind of thing. So, + + align:start position:0% + + + + align:start position:0% + +as an aside, when Bob Merin was here + + align:start position:0% +as an aside, when Bob Merin was here + + + align:start position:0% +as an aside, when Bob Merin was here +working out all this stuff for the first + + align:start position:0% +working out all this stuff for the first + + + align:start position:0% +working out all this stuff for the first +time in the late60s, + + align:start position:0% +time in the late60s, + + + align:start position:0% +time in the late60s, +uh, he knew the standard notation for + + align:start position:0% +uh, he knew the standard notation for + + + align:start position:0% +uh, he knew the standard notation for +standard branding motion was W., but it + + align:start position:0% +standard branding motion was W., but it + + + align:start position:0% +standard branding motion was W., but it +turns out in finance the standard + + align:start position:0% +turns out in finance the standard + + + align:start position:0% +turns out in finance the standard +notation for wealth is also W. And so + + align:start position:0% +notation for wealth is also W. And so + + + align:start position:0% +notation for wealth is also W. And so +and he wanted to work on stochastic + + align:start position:0% +and he wanted to work on stochastic + + + align:start position:0% +and he wanted to work on stochastic +wealth dynamics. And so he had to choose + + align:start position:0% +wealth dynamics. And so he had to choose + + + align:start position:0% +wealth dynamics. And so he had to choose +should I use the letter W for wealth or + + align:start position:0% +should I use the letter W for wealth or + + + align:start position:0% +should I use the letter W for wealth or +should I use the letter W for wiener + + align:start position:0% +should I use the letter W for wiener + + + align:start position:0% +should I use the letter W for wiener +process. And he chose W for wealth which + + align:start position:0% +process. And he chose W for wealth which + + + align:start position:0% +process. And he chose W for wealth which +meant he had to pick a different letter + + align:start position:0% +meant he had to pick a different letter + + + align:start position:0% +meant he had to pick a different letter +for wiener process. And so he actually + + align:start position:0% +for wiener process. And so he actually + + + align:start position:0% +for wiener process. And so he actually +chose the letter Z. And so uh so and + + align:start position:0% +chose the letter Z. And so uh so and + + + align:start position:0% +chose the letter Z. And so uh so and +don't ask you'll have to ask him why he + + align:start position:0% +don't ask you'll have to ask him why he + + + align:start position:0% +don't ask you'll have to ask him why he +chose that letter because it doesn't + + align:start position:0% +chose that letter because it doesn't + + + align:start position:0% +chose that letter because it doesn't +stand for anything as far as I know + + align:start position:0% +stand for anything as far as I know + + + align:start position:0% +stand for anything as far as I know +except that actually the sample paths of + + align:start position:0% +except that actually the sample paths of + + + align:start position:0% +except that actually the sample paths of +a wiener process they look very very + + align:start position:0% +a wiener process they look very very + + + align:start position:0% +a wiener process they look very very +jagged and so if you turn your head you + + align:start position:0% +jagged and so if you turn your head you + + + align:start position:0% +jagged and so if you turn your head you +might be able to see a Z. Okay. Okay. + + align:start position:0% +might be able to see a Z. Okay. Okay. + + + align:start position:0% +might be able to see a Z. Okay. Okay. +Okay. + + align:start position:0% + + + + align:start position:0% + +So um another assumption is we're going + + align:start position:0% +So um another assumption is we're going + + + align:start position:0% +So um another assumption is we're going +to restrict the possible dynamics of the + + align:start position:0% +to restrict the possible dynamics of the + + + align:start position:0% +to restrict the possible dynamics of the +numerator portfolio's value. So we're + + align:start position:0% +numerator portfolio's value. So we're + + + align:start position:0% +numerator portfolio's value. So we're +going to let L denote the value of this + + align:start position:0% +going to let L denote the value of this + + + align:start position:0% +going to let L denote the value of this +numeral portfolio. And the pneummonic + + align:start position:0% +numeral portfolio. And the pneummonic + + + align:start position:0% +numeral portfolio. And the pneummonic +here is that John Long uh invented this + + align:start position:0% +here is that John Long uh invented this + + + align:start position:0% +here is that John Long uh invented this +concept. So we're calling L for long. + + align:start position:0% +concept. So we're calling L for long. + + + align:start position:0% +concept. So we're calling L for long. +Now it's unfortunate that the inventor + + align:start position:0% +Now it's unfortunate that the inventor + + + align:start position:0% +Now it's unfortunate that the inventor +of this concept was named long actually + + align:start position:0% +of this concept was named long actually + + + align:start position:0% +of this concept was named long actually +because uh in finance the word long + + align:start position:0% +because uh in finance the word long + + + align:start position:0% +because uh in finance the word long +indicates that you you know that you're + + align:start position:0% +indicates that you you know that you're + + + align:start position:0% +indicates that you you know that you're +you're okay for a non for for a security + + align:start position:0% +you're okay for a non for for a security + + + align:start position:0% +you're okay for a non for for a security +with a non-negative payoff. If you're + + align:start position:0% +with a non-negative payoff. If you're + + + align:start position:0% +with a non-negative payoff. If you're +long then you're going to be receiving + + align:start position:0% +long then you're going to be receiving + + + align:start position:0% +long then you're going to be receiving +that payoff. Okay? is you pay money now + + align:start position:0% +that payoff. Okay? is you pay money now + + + align:start position:0% +that payoff. Okay? is you pay money now +and you receive that payoff. It's the + + align:start position:0% +and you receive that payoff. It's the + + + align:start position:0% +and you receive that payoff. It's the +opposite of short where if you're short + + align:start position:0% +opposite of short where if you're short + + + align:start position:0% +opposite of short where if you're short +a security with a non-gative payoff then + + align:start position:0% +a security with a non-gative payoff then + + + align:start position:0% +a security with a non-gative payoff then +actually you get money now and you have + + align:start position:0% +actually you get money now and you have + + + align:start position:0% +actually you get money now and you have +to deliver that payoff later. So um so + + align:start position:0% +to deliver that payoff later. So um so + + + align:start position:0% +to deliver that payoff later. So um so +as it happens this numero portfolio + + align:start position:0% +as it happens this numero portfolio + + + align:start position:0% +as it happens this numero portfolio +it has you know multiple positions in it + + align:start position:0% +it has you know multiple positions in it + + + align:start position:0% +it has you know multiple positions in it +and the signs of the positions are + + align:start position:0% +and the signs of the positions are + + + align:start position:0% +and the signs of the positions are +allowed to be real so positives and + + align:start position:0% +allowed to be real so positives and + + + align:start position:0% +allowed to be real so positives and +negatives. So um so it's a kind of a + + align:start position:0% +negatives. So um so it's a kind of a + + + align:start position:0% +negatives. So um so it's a kind of a +misnomer. uh I say Long's numerator + + align:start position:0% +misnomer. uh I say Long's numerator + + + align:start position:0% +misnomer. uh I say Long's numerator +portfolio and everyone thinks the + + align:start position:0% +portfolio and everyone thinks the + + + align:start position:0% +portfolio and everyone thinks the +positions in them are all positive. + + align:start position:0% +positions in them are all positive. + + + align:start position:0% +positions in them are all positive. +Okay, it's not true. So the real value. + + align:start position:0% +Okay, it's not true. So the real value. + + + align:start position:0% +Okay, it's not true. So the real value. +So anyway and um so the setting the the + + align:start position:0% +So anyway and um so the setting the the + + + align:start position:0% +So anyway and um so the setting the the +kind of problem here is that we've put + + align:start position:0% +kind of problem here is that we've put + + + align:start position:0% +kind of problem here is that we've put +the structure on the value L of John + + align:start position:0% +the structure on the value L of John + + + align:start position:0% +the structure on the value L of John +Long's numerical portfolio namely that L + + align:start position:0% +Long's numerical portfolio namely that L + + + align:start position:0% +Long's numerical portfolio namely that L +is a diffusion + + align:start position:0% +is a diffusion + + + align:start position:0% +is a diffusion +um in well + + align:start position:0% +um in well + + + align:start position:0% +um in well +well let me rephrase that L is a + + align:start position:0% +well let me rephrase that L is a + + + align:start position:0% +well let me rephrase that L is a +continuous process and um let's say + + align:start position:0% +continuous process and um let's say + + + align:start position:0% +continuous process and um let's say +um but the um it's not quite a diffusion + + align:start position:0% +um but the um it's not quite a diffusion + + + align:start position:0% +um but the um it's not quite a diffusion +in itself it's um The only thing you can + + align:start position:0% +in itself it's um The only thing you can + + + align:start position:0% +in itself it's um The only thing you can +say is that the pair X and L are a + + align:start position:0% +say is that the pair X and L are a + + + align:start position:0% +say is that the pair X and L are a +bariate diffusion because the + + align:start position:0% +bariate diffusion because the + + + align:start position:0% +bariate diffusion because the +coefficients if you bring this L over + + align:start position:0% +coefficients if you bring this L over + + + align:start position:0% +coefficients if you bring this L over +the other side you can see the + + align:start position:0% +the other side you can see the + + + align:start position:0% +the other side you can see the +coefficients for DL depend on L and X + + align:start position:0% +coefficients for DL depend on L and X + + + align:start position:0% +coefficients for DL depend on L and X +and same thing with the volatility part. + + align:start position:0% +and same thing with the volatility part. + + + align:start position:0% +and same thing with the volatility part. +So anyway um we placed the structure and + + align:start position:0% +So anyway um we placed the structure and + + + align:start position:0% +So anyway um we placed the structure and +the idea is that we know from looking at + + align:start position:0% +the idea is that we know from looking at + + + align:start position:0% +the idea is that we know from looking at +Bloomberg what the risk not drift of X + + align:start position:0% +Bloomberg what the risk not drift of X + + + align:start position:0% +Bloomberg what the risk not drift of X +is that's BQX we know that function we + + align:start position:0% +is that's BQX we know that function we + + + align:start position:0% +is that's BQX we know that function we +know what the diffusion coefficient of X + + align:start position:0% +know what the diffusion coefficient of X + + + align:start position:0% +know what the diffusion coefficient of X +is that's the function A of X we know + + align:start position:0% +is that's the function A of X we know + + + align:start position:0% +is that's the function A of X we know +what the risk not drift of L is that's + + align:start position:0% +what the risk not drift of L is that's + + + align:start position:0% +what the risk not drift of L is that's +that function R of X but we don't know + + align:start position:0% +that function R of X but we don't know + + + align:start position:0% +that function R of X but we don't know +the volatility of John Long's numer + + align:start position:0% +the volatility of John Long's numer + + + align:start position:0% +the volatility of John Long's numer +portfolio that's the function sigma L of + + align:start position:0% +portfolio that's the function sigma L of + + + align:start position:0% +portfolio that's the function sigma L of +And if only we could find it, we would + + align:start position:0% +And if only we could find it, we would + + + align:start position:0% +And if only we could find it, we would +actually know how to determine the real + + align:start position:0% +actually know how to determine the real + + + align:start position:0% +actually know how to determine the real +world drift. And like remember going I + + align:start position:0% +world drift. And like remember going I + + + align:start position:0% +world drift. And like remember going I +was going back to remember I was saying + + align:start position:0% +was going back to remember I was saying + + + align:start position:0% +was going back to remember I was saying +if IBM and you were could put in an + + align:start position:0% +if IBM and you were could put in an + + + align:start position:0% +if IBM and you were could put in an +American bank account and + + align:start position:0% +American bank account and + + + align:start position:0% +American bank account and +uh let's say there was certain growth + + align:start position:0% +uh let's say there was certain growth + + + align:start position:0% +uh let's say there was certain growth +rate there and then if instead you were + + align:start position:0% +rate there and then if instead you were + + + align:start position:0% +rate there and then if instead you were +putting those gains in a British bank + + align:start position:0% +putting those gains in a British bank + + + align:start position:0% +putting those gains in a British bank +account you'd achieve a different growth + + align:start position:0% +account you'd achieve a different growth + + + align:start position:0% +account you'd achieve a different growth +rate. And I was stressing that the + + align:start position:0% +rate. And I was stressing that the + + + align:start position:0% +rate. And I was stressing that the +correlation of um of dollar pound with + + align:start position:0% +correlation of um of dollar pound with + + + align:start position:0% +correlation of um of dollar pound with +IBM was important for determining that + + align:start position:0% +IBM was important for determining that + + + align:start position:0% +IBM was important for determining that +growth rate and I stand by that. Um when + + align:start position:0% +growth rate and I stand by that. Um when + + + align:start position:0% +growth rate and I stand by that. Um when +you're in a one-factor world that + + align:start position:0% +you're in a one-factor world that + + + align:start position:0% +you're in a one-factor world that +correlation can only be one and um so + + align:start position:0% +correlation can only be one and um so + + + align:start position:0% +correlation can only be one and um so +that's what's happening here. We're in a + + align:start position:0% +that's what's happening here. We're in a + + + align:start position:0% +that's what's happening here. We're in a +one- factor world and that correlation + + align:start position:0% +one- factor world and that correlation + + + align:start position:0% +one- factor world and that correlation +is one. And um the um the other thing + + align:start position:0% +is one. And um the um the other thing + + + align:start position:0% +is one. And um the um the other thing +that affects the growth rate though of + + align:start position:0% +that affects the growth rate though of + + + align:start position:0% +that affects the growth rate though of +your British bank account balance is + + align:start position:0% +your British bank account balance is + + + align:start position:0% +your British bank account balance is +actually the volatility of the exchange + + align:start position:0% +actually the volatility of the exchange + + + align:start position:0% +actually the volatility of the exchange +rate. So what actually matters is the + + align:start position:0% +rate. So what actually matters is the + + + align:start position:0% +rate. So what actually matters is the +covariance between the British exchange + + align:start position:0% +covariance between the British exchange + + + align:start position:0% +covariance between the British exchange +rate and IBM. That coariance depends on + + align:start position:0% +rate and IBM. That coariance depends on + + + align:start position:0% +rate and IBM. That coariance depends on +both the correlation and the volatility + + align:start position:0% +both the correlation and the volatility + + + align:start position:0% +both the correlation and the volatility +of the FX rate. So you can think of the + + align:start position:0% +of the FX rate. So you can think of the + + + align:start position:0% +of the FX rate. So you can think of the +FX radius here, John Long's numerator + + align:start position:0% +FX radius here, John Long's numerator + + + align:start position:0% +FX radius here, John Long's numerator +portfolio. And so that sigma L is um + + align:start position:0% +portfolio. And so that sigma L is um + + + align:start position:0% +portfolio. And so that sigma L is um +sort of the key. It's like we've set + + align:start position:0% +sort of the key. It's like we've set + + + align:start position:0% +sort of the key. It's like we've set +things up so we know the correlation, + + align:start position:0% +things up so we know the correlation, + + + align:start position:0% +things up so we know the correlation, +but we still don't know the coariance. + + align:start position:0% +but we still don't know the coariance. + + + align:start position:0% +but we still don't know the coariance. +And that's what's actually relevant. So + + align:start position:0% +And that's what's actually relevant. So + + + align:start position:0% +And that's what's actually relevant. So +as soon as we get the sigma L, we'll + + align:start position:0% +as soon as we get the sigma L, we'll + + + align:start position:0% +as soon as we get the sigma L, we'll +know the coariance and um so we'll be in + + align:start position:0% +know the coariance and um so we'll be in + + + align:start position:0% +know the coariance and um so we'll be in +shape. Okay. So so we got to find that + + align:start position:0% +shape. Okay. So so we got to find that + + + align:start position:0% +shape. Okay. So so we got to find that +volatility uh function sigma L. And now + + align:start position:0% +volatility uh function sigma L. And now + + + align:start position:0% +volatility uh function sigma L. And now +I know many of you have classes, so I'm + + align:start position:0% +I know many of you have classes, so I'm + + + align:start position:0% +I know many of you have classes, so I'm +going to have to start moving. + + align:start position:0% +going to have to start moving. + + + align:start position:0% +going to have to start moving. +Yeah, people will have access to these + + align:start position:0% +Yeah, people will have access to these + + + align:start position:0% +Yeah, people will have access to these +slides afterwards. Yes. + + align:start position:0% +slides afterwards. Yes. + + + align:start position:0% +slides afterwards. Yes. +15 slides left. Yes. Well, actually, + + align:start position:0% +15 slides left. Yes. Well, actually, + + + align:start position:0% +15 slides left. Yes. Well, actually, +you'll be good glad to know that five of + + align:start position:0% +you'll be good glad to know that five of + + + align:start position:0% +you'll be good glad to know that five of +those are disclaimers. + + align:start position:0% +those are disclaimers. + + + align:start position:0% +those are disclaimers. +So So + + align:start position:0% +So So + + + align:start position:0% +So So +yeah, if I could move but to what you + + align:start position:0% +yeah, if I could move but to what you + + + align:start position:0% +yeah, if I could move but to what you +know the keys towards the end. Yes. Yes. + + align:start position:0% +know the keys towards the end. Yes. Yes. + + + align:start position:0% +know the keys towards the end. Yes. Yes. +Absolutely. We're very close. Okay. So + + align:start position:0% +Absolutely. We're very close. Okay. So + + + align:start position:0% +Absolutely. We're very close. Okay. So +I'll be done in two minutes. Okay. So um + + align:start position:0% +I'll be done in two minutes. Okay. So um + + + align:start position:0% +I'll be done in two minutes. Okay. So um +so basically where we are now is uh + + align:start position:0% +so basically where we are now is uh + + + align:start position:0% +so basically where we are now is uh +we're going to make one more assumption + + align:start position:0% +we're going to make one more assumption + + + align:start position:0% +we're going to make one more assumption +that the value of John L's new portfolio + + align:start position:0% +that the value of John L's new portfolio + + + align:start position:0% +that the value of John L's new portfolio +is a function of x and d. Okay then + + align:start position:0% +is a function of x and d. Okay then + + + align:start position:0% +is a function of x and d. Okay then +let's say we've made all our assumptions + + align:start position:0% +let's say we've made all our assumptions + + + align:start position:0% +let's say we've made all our assumptions +and where it goes is that uh the + + align:start position:0% +and where it goes is that uh the + + + align:start position:0% +and where it goes is that uh the +assumptions imply that this value + + align:start position:0% +assumptions imply that this value + + + align:start position:0% +assumptions imply that this value +function splits into an unknown positive + + align:start position:0% +function splits into an unknown positive + + + align:start position:0% +function splits into an unknown positive +function of x and an unknown positive + + align:start position:0% +function of x and an unknown positive + + + align:start position:0% +function of x and an unknown positive +function of time. And um when you kind + + align:start position:0% +function of time. And um when you kind + + + align:start position:0% +function of time. And um when you kind +of further analyze, you find that the + + align:start position:0% +of further analyze, you find that the + + + align:start position:0% +of further analyze, you find that the +unknown function of time is an + + align:start position:0% +unknown function of time is an + + + align:start position:0% +unknown function of time is an +exponential function of time and the + + align:start position:0% +exponential function of time and the + + + align:start position:0% +exponential function of time and the +unknown function of x solves an ordinary + + align:start position:0% +unknown function of x solves an ordinary + + + align:start position:0% +unknown function of x solves an ordinary +differential equation + + align:start position:0% +differential equation + + + align:start position:0% +differential equation +uh with uh of this kind. So this is + + align:start position:0% +uh with uh of this kind. So this is + + + align:start position:0% +uh with uh of this kind. So this is +called a sterm Louisville problem. And + + align:start position:0% +called a sterm Louisville problem. And + + + align:start position:0% +called a sterm Louisville problem. And +um it turns out that um Sturm and + + align:start position:0% +um it turns out that um Sturm and + + + align:start position:0% +um it turns out that um Sturm and +Louisville were the only mathematicians + + align:start position:0% +Louisville were the only mathematicians + + + align:start position:0% +Louisville were the only mathematicians +I mentioned in this talk who were not at + + align:start position:0% +I mentioned in this talk who were not at + + + align:start position:0% +I mentioned in this talk who were not at +MIT. And uh they uh actually solved this + + align:start position:0% +MIT. And uh they uh actually solved this + + + align:start position:0% +MIT. And uh they uh actually solved this +problem or made and um one of the things + + align:start position:0% +problem or made and um one of the things + + + align:start position:0% +problem or made and um one of the things +they show is that when you're searching + + align:start position:0% +they show is that when you're searching + + + align:start position:0% +they show is that when you're searching +for functions pi and scalers lambda that + + align:start position:0% +for functions pi and scalers lambda that + + + align:start position:0% +for functions pi and scalers lambda that +solve this problem, there's only one + + align:start position:0% +solve this problem, there's only one + + + align:start position:0% +solve this problem, there's only one +solution that um get delivers you a + + align:start position:0% +solution that um get delivers you a + + + align:start position:0% +solution that um get delivers you a +positive function pi. And so this is how + + align:start position:0% +positive function pi. And so this is how + + + align:start position:0% +positive function pi. And so this is how +you get uniqueness. So this is the same + + align:start position:0% +you get uniqueness. So this is the same + + + align:start position:0% +you get uniqueness. So this is the same +remember I was saying back with 11. So + + align:start position:0% +remember I was saying back with 11. So + + + align:start position:0% +remember I was saying back with 11. So +we're look searching for like a 10 + + align:start position:0% +we're look searching for like a 10 + + + align:start position:0% +we're look searching for like a 10 +vector and a scaler. Now the 10 vector + + align:start position:0% +vector and a scaler. Now the 10 vector + + + align:start position:0% +vector and a scaler. Now the 10 vector +is a function and that function is pi. + + align:start position:0% +is a function and that function is pi. + + + align:start position:0% +is a function and that function is pi. +Okay. And the scaler is lambda. So so + + align:start position:0% +Okay. And the scaler is lambda. So so + + + align:start position:0% +Okay. And the scaler is lambda. So so +anyway, so the point is is that the math + + align:start position:0% +anyway, so the point is is that the math + + + align:start position:0% +anyway, so the point is is that the math +implies there's unique solution the + + align:start position:0% +implies there's unique solution the + + + align:start position:0% +implies there's unique solution the +problem. So we learn the volatility of + + align:start position:0% +problem. So we learn the volatility of + + + align:start position:0% +problem. So we learn the volatility of +the numerator portfolio in the end and + + align:start position:0% +the numerator portfolio in the end and + + + align:start position:0% +the numerator portfolio in the end and +then we learn the drift of everything + + align:start position:0% +then we learn the drift of everything + + + align:start position:0% +then we learn the drift of everything +you want to know under the market's + + align:start position:0% +you want to know under the market's + + + align:start position:0% +you want to know under the market's +beliefs. And so that's the the gist of + + align:start position:0% +beliefs. And so that's the the gist of + + + align:start position:0% +beliefs. And so that's the the gist of +it. Um so then there's been work on + + align:start position:0% +it. Um so then there's been work on + + + align:start position:0% +it. Um so then there's been work on +trying to extend to unbounded intervals + + align:start position:0% +trying to extend to unbounded intervals + + + align:start position:0% +trying to extend to unbounded intervals +and basically in the famous black + + align:start position:0% +and basically in the famous black + + + align:start position:0% +and basically in the famous black +scholes model this uh effort fails + + align:start position:0% +scholes model this uh effort fails + + + align:start position:0% +scholes model this uh effort fails +whereas in the less famous but still + + align:start position:0% +whereas in the less famous but still + + + align:start position:0% +whereas in the less famous but still +important coxinger cell ros model this + + align:start position:0% +important coxinger cell ros model this + + + align:start position:0% +important coxinger cell ros model this +effort succeeds. So the sort of + + align:start position:0% +effort succeeds. So the sort of + + + align:start position:0% +effort succeeds. So the sort of +punchline is that when it comes to + + align:start position:0% +punchline is that when it comes to + + + align:start position:0% +punchline is that when it comes to +unbounded + + align:start position:0% +unbounded + + + align:start position:0% +unbounded +state space the theory is open. So, uh, + + align:start position:0% +state space the theory is open. So, uh, + + + align:start position:0% +state space the theory is open. So, uh, +if there's a grad student in the room + + align:start position:0% +if there's a grad student in the room + + + align:start position:0% +if there's a grad student in the room +who wants a good dissertation problem, + + align:start position:0% +who wants a good dissertation problem, + + + align:start position:0% +who wants a good dissertation problem, +this is it. Okay. So, uh, so that's all + + align:start position:0% +this is it. Okay. So, uh, so that's all + + + align:start position:0% +this is it. Okay. So, uh, so that's all +I wanted to say today. Thanks. Okay. \ No newline at end of file diff --git a/wHeJbvRoj00.txt b/wHeJbvRoj00.txt new file mode 100644 index 0000000000000000000000000000000000000000..f62f554c335c236d08cc555e2a3344b2122d4e63 --- /dev/null +++ b/wHeJbvRoj00.txt @@ -0,0 +1,19357 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a creative commons license your support + + align:start position:0% +a creative commons license your support + + + align:start position:0% +a creative commons license your support +will help mit opencourseware continue to + + align:start position:0% +will help mit opencourseware continue to + + + align:start position:0% +will help mit opencourseware continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of mit courses + + align:start position:0% +materials from hundreds of mit courses + + + align:start position:0% +materials from hundreds of mit courses +visit mit opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +let me hand it over to + + align:start position:0% +let me hand it over to + + + align:start position:0% +let me hand it over to +ankit now + + align:start position:0% +ankit now + + + align:start position:0% +ankit now +and we're going to talk about color + + align:start position:0% + + + + align:start position:0% + +so i'm going to start with something + + align:start position:0% +so i'm going to start with something + + + align:start position:0% +so i'm going to start with something +that i discussed a few weeks back when + + align:start position:0% +that i discussed a few weeks back when + + + align:start position:0% +that i discussed a few weeks back when +we were talking about epsilon + + align:start position:0% +we were talking about epsilon + + + align:start position:0% +we were talking about epsilon +photography and + + align:start position:0% +photography and + + + align:start position:0% +photography and +if you remember this slide i had back + + align:start position:0% +if you remember this slide i had back + + + align:start position:0% +if you remember this slide i had back +then + + align:start position:0% +then + + + align:start position:0% +then +and this is one of the oldest ways of + + align:start position:0% +and this is one of the oldest ways of + + + align:start position:0% +and this is one of the oldest ways of +creating color images you just capture + + align:start position:0% +creating color images you just capture + + + align:start position:0% +creating color images you just capture +three images over time one with a green + + align:start position:0% +three images over time one with a green + + + align:start position:0% +three images over time one with a green +filter in front of the camera lens one + + align:start position:0% +filter in front of the camera lens one + + + align:start position:0% +filter in front of the camera lens one +with a red one with a blue filter and + + align:start position:0% +with a red one with a blue filter and + + + align:start position:0% +with a red one with a blue filter and +from these three images if you project + + align:start position:0% +from these three images if you project + + + align:start position:0% +from these three images if you project +them back on a white surface again + + align:start position:0% +them back on a white surface again + + + align:start position:0% +them back on a white surface again +through three different projectors one + + align:start position:0% +through three different projectors one + + + align:start position:0% +through three different projectors one +with a green one with a red and one with + + align:start position:0% +with a green one with a red and one with + + + align:start position:0% +with a green one with a red and one with +a blue filter in front of it you will + + align:start position:0% +a blue filter in front of it you will + + + align:start position:0% +a blue filter in front of it you will +get what looks like a color image to the + + align:start position:0% +get what looks like a color image to the + + + align:start position:0% +get what looks like a color image to the +human eye + + align:start position:0% +human eye + + + align:start position:0% +human eye +and this is stuff that was done more + + align:start position:0% +and this is stuff that was done more + + + align:start position:0% +and this is stuff that was done more +than a century ago and + + align:start position:0% +than a century ago and + + + align:start position:0% +than a century ago and +you can take these images now these + + align:start position:0% +you can take these images now these + + + align:start position:0% +you can take these images now these +individual grayscale images and color + + align:start position:0% +individual grayscale images and color + + + align:start position:0% +individual grayscale images and color +tint them and then again add them back + + align:start position:0% +tint them and then again add them back + + + align:start position:0% +tint them and then again add them back +together similar to what you did for + + align:start position:0% +together similar to what you did for + + + align:start position:0% +together similar to what you did for +your assignment when you were adding the + + align:start position:0% +your assignment when you were adding the + + + align:start position:0% +your assignment when you were adding the +lighting and you can create these + + align:start position:0% +lighting and you can create these + + + align:start position:0% +lighting and you can create these +digitally and now there's a whole + + align:start position:0% +digitally and now there's a whole + + + align:start position:0% +digitally and now there's a whole +library of library of congress has this + + align:start position:0% +library of library of congress has this + + + align:start position:0% +library of library of congress has this +huge + + align:start position:0% +huge + + + align:start position:0% +huge +database of images that they're by + + align:start position:0% +database of images that they're by + + + align:start position:0% +database of images that they're by +registering them they've recreated these + + align:start position:0% +registering them they've recreated these + + + align:start position:0% +registering them they've recreated these +color images from black and white images + + align:start position:0% +color images from black and white images + + + align:start position:0% +color images from black and white images +um so this is one way of creating color + + align:start position:0% +um so this is one way of creating color + + + align:start position:0% +um so this is one way of creating color +in in photography + + align:start position:0% +in in photography + + + align:start position:0% +in in photography +another sort of related + + align:start position:0% +another sort of related + + + align:start position:0% +another sort of related +similar thing to this is the color wheel + + align:start position:0% +similar thing to this is the color wheel + + + align:start position:0% +similar thing to this is the color wheel +i just wanted to this is something again + + align:start position:0% +i just wanted to this is something again + + + align:start position:0% +i just wanted to this is something again +i talked about in the previous class and + + align:start position:0% +i talked about in the previous class and + + + align:start position:0% +i talked about in the previous class and +it's something that's used more for + + align:start position:0% +it's something that's used more for + + + align:start position:0% +it's something that's used more for +projectors you have this color wheel + + align:start position:0% +projectors you have this color wheel + + + align:start position:0% +projectors you have this color wheel +rotating in front of this probably has + + align:start position:0% +rotating in front of this probably has + + + align:start position:0% +rotating in front of this probably has +one if it's a dlp projector + + align:start position:0% +one if it's a dlp projector + + + align:start position:0% +one if it's a dlp projector +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +at any given time you're just projecting + + align:start position:0% +at any given time you're just projecting + + + align:start position:0% +at any given time you're just projecting +one component of the light you're either + + align:start position:0% +one component of the light you're either + + + align:start position:0% +one component of the light you're either +green red or blue + + align:start position:0% +green red or blue + + + align:start position:0% +green red or blue +and the human eye actually integrates it + + align:start position:0% +and the human eye actually integrates it + + + align:start position:0% +and the human eye actually integrates it +over time because it it happens in rapid + + align:start position:0% +over time because it it happens in rapid + + + align:start position:0% +over time because it it happens in rapid +succession one after the other + + align:start position:0% +succession one after the other + + + align:start position:0% +succession one after the other +so it's a little different from the + + align:start position:0% +so it's a little different from the + + + align:start position:0% +so it's a little different from the +previous case in which you were + + align:start position:0% +previous case in which you were + + + align:start position:0% +previous case in which you were +projecting all three at the same time + + align:start position:0% +projecting all three at the same time + + + align:start position:0% +projecting all three at the same time +and light was adding in space here light + + align:start position:0% +and light was adding in space here light + + + align:start position:0% +and light was adding in space here light +gets integrated over time you get the + + align:start position:0% +gets integrated over time you get the + + + align:start position:0% +gets integrated over time you get the +effect of color + + align:start position:0% + + + + align:start position:0% + +so a third thing that i discussed + + align:start position:0% +so a third thing that i discussed + + + align:start position:0% +so a third thing that i discussed +previous in the previous class was this + + align:start position:0% +previous in the previous class was this + + + align:start position:0% +previous in the previous class was this +concept of three ccd sensors where you + + align:start position:0% +concept of three ccd sensors where you + + + align:start position:0% +concept of three ccd sensors where you +use these dichroic prisms and mirrors + + align:start position:0% +use these dichroic prisms and mirrors + + + align:start position:0% +use these dichroic prisms and mirrors +and + + align:start position:0% +and + + + align:start position:0% +and +you split light into the three + + align:start position:0% +you split light into the three + + + align:start position:0% +you split light into the three +wavelength regions and when you have + + align:start position:0% +wavelength regions and when you have + + + align:start position:0% +wavelength regions and when you have +three separate sensors that capture the + + align:start position:0% +three separate sensors that capture the + + + align:start position:0% +three separate sensors that capture the +three wavelengths and you get using + + align:start position:0% +three wavelengths and you get using + + + align:start position:0% +three wavelengths and you get using +three monochrome ccd's you can capture a + + align:start position:0% +three monochrome ccd's you can capture a + + + align:start position:0% +three monochrome ccd's you can capture a +color image + + align:start position:0% + + + + align:start position:0% + +this is probably what's the most popular + + align:start position:0% +this is probably what's the most popular + + + align:start position:0% +this is probably what's the most popular +in most still cameras and also many of + + align:start position:0% +in most still cameras and also many of + + + align:start position:0% +in most still cameras and also many of +the digital cameras and it's basically + + align:start position:0% +the digital cameras and it's basically + + + align:start position:0% +the digital cameras and it's basically +what's called the bear mosaic that's + + align:start position:0% +what's called the bear mosaic that's + + + align:start position:0% +what's called the bear mosaic that's +because the person who invented it from + + align:start position:0% +because the person who invented it from + + + align:start position:0% +because the person who invented it from +kodak his name was bear + + align:start position:0% +kodak his name was bear + + + align:start position:0% +kodak his name was bear +and uh he had this patent in i think mid + + align:start position:0% +and uh he had this patent in i think mid + + + align:start position:0% +and uh he had this patent in i think mid +late 70s which describes this technique + + align:start position:0% +late 70s which describes this technique + + + align:start position:0% +late 70s which describes this technique +the basic idea is that instead of having + + align:start position:0% +the basic idea is that instead of having + + + align:start position:0% +the basic idea is that instead of having +monochrome pixels you + + align:start position:0% +monochrome pixels you + + + align:start position:0% +monochrome pixels you +you put these little filters tiny + + align:start position:0% +you put these little filters tiny + + + align:start position:0% +you put these little filters tiny +filters on top of the pixels and + + align:start position:0% +filters on top of the pixels and + + + align:start position:0% +filters on top of the pixels and +the filters are sort of you have two + + align:start position:0% +the filters are sort of you have two + + + align:start position:0% +the filters are sort of you have two +green filters and one red and one blue + + align:start position:0% +green filters and one red and one blue + + + align:start position:0% +green filters and one red and one blue +filter in a two by two region and then + + align:start position:0% +filter in a two by two region and then + + + align:start position:0% +filter in a two by two region and then +this two by two thing is tiled all over + + align:start position:0% +this two by two thing is tiled all over + + + align:start position:0% +this two by two thing is tiled all over +the sensor so any one pixel is only + + align:start position:0% +the sensor so any one pixel is only + + + align:start position:0% +the sensor so any one pixel is only +sensing one + + align:start position:0% +sensing one + + + align:start position:0% +sensing one +uh wavelength either red green or blue + + align:start position:0% +uh wavelength either red green or blue + + + align:start position:0% +uh wavelength either red green or blue +uh + + align:start position:0% +uh + + + align:start position:0% +uh +when i say wavelength it's actually a + + align:start position:0% +when i say wavelength it's actually a + + + align:start position:0% +when i say wavelength it's actually a +whole band of wavelengths but let's just + + align:start position:0% +whole band of wavelengths but let's just + + + align:start position:0% +whole band of wavelengths but let's just +stick with color for now uh and so it's + + align:start position:0% +stick with color for now uh and so it's + + + align:start position:0% +stick with color for now uh and so it's +it's sensing just one of these three + + align:start position:0% +it's sensing just one of these three + + + align:start position:0% +it's sensing just one of these three +colors and then they use + + align:start position:0% +colors and then they use + + + align:start position:0% +colors and then they use +uh clever demosaicing algorithms which + + align:start position:0% +uh clever demosaicing algorithms which + + + align:start position:0% +uh clever demosaicing algorithms which +essentially interpolate between the + + align:start position:0% +essentially interpolate between the + + + align:start position:0% +essentially interpolate between the +image that's sensed so for example + + align:start position:0% +image that's sensed so for example + + + align:start position:0% +image that's sensed so for example +at a pixel which senses only red you + + align:start position:0% +at a pixel which senses only red you + + + align:start position:0% +at a pixel which senses only red you +would interpolate between the + + align:start position:0% +would interpolate between the + + + align:start position:0% +would interpolate between the +neighboring green pixels in order to + + align:start position:0% +neighboring green pixels in order to + + + align:start position:0% +neighboring green pixels in order to +estimate what the + + align:start position:0% +estimate what the + + + align:start position:0% +estimate what the +green color is over there while still + + align:start position:0% +green color is over there while still + + + align:start position:0% +green color is over there while still +making use of the + + align:start position:0% +making use of the + + + align:start position:0% +making use of the +color that's sensor over there the red + + align:start position:0% +color that's sensor over there the red + + + align:start position:0% +color that's sensor over there the red +color so what you see in most images is + + align:start position:0% +color so what you see in most images is + + + align:start position:0% +color so what you see in most images is +almost kind of you're hallucinating the + + align:start position:0% +almost kind of you're hallucinating the + + + align:start position:0% +almost kind of you're hallucinating the +higher resolution because you're + + align:start position:0% +higher resolution because you're + + + align:start position:0% +higher resolution because you're +going up by a factor of three in the + + align:start position:0% +going up by a factor of three in the + + + align:start position:0% +going up by a factor of three in the +resolution in the image when you do this + + align:start position:0% +resolution in the image when you do this + + + align:start position:0% +resolution in the image when you do this +kind of interpolation + + align:start position:0% +kind of interpolation + + + align:start position:0% +kind of interpolation +and if you have a four megapixel camera + + align:start position:0% +and if you have a four megapixel camera + + + align:start position:0% +and if you have a four megapixel camera +and here it looks like + + align:start position:0% +and here it looks like + + + align:start position:0% +and here it looks like +we have + + align:start position:0% +we have + + + align:start position:0% +we have +for every four pixels we have + + align:start position:0% +for every four pixels we have + + + align:start position:0% +for every four pixels we have +two green + + align:start position:0% +two green + + + align:start position:0% +two green +one blue and one red + + align:start position:0% +one blue and one red + + + align:start position:0% +one blue and one red +so if you take a 4 megapixel picture + + align:start position:0% +so if you take a 4 megapixel picture + + + align:start position:0% +so if you take a 4 megapixel picture +how many pixels are actually + + align:start position:0% +how many pixels are actually + + + align:start position:0% +how many pixels are actually +taking each of those colors + + align:start position:0% + + + + align:start position:0% + +this 4 megapixel camera actually giving + + align:start position:0% +this 4 megapixel camera actually giving + + + align:start position:0% +this 4 megapixel camera actually giving +you 12 megapixels because when the image + + align:start position:0% +you 12 megapixels because when the image + + + align:start position:0% +you 12 megapixels because when the image +comes out + + align:start position:0% +comes out + + + align:start position:0% +comes out +it's four megapixel and red four + + align:start position:0% +it's four megapixel and red four + + + align:start position:0% +it's four megapixel and red four +megapixel in blue and four megapixel in + + align:start position:0% +megapixel in blue and four megapixel in + + + align:start position:0% +megapixel in blue and four megapixel in +green + + align:start position:0% +green + + + align:start position:0% +green +doug + + align:start position:0% +doug + + + align:start position:0% +doug +no + + align:start position:0% +no + + + align:start position:0% +no +so what is going on it's well i mean you + + align:start position:0% +so what is going on it's well i mean you + + + align:start position:0% +so what is going on it's well i mean you +only you get the resolution for each of + + align:start position:0% +only you get the resolution for each of + + + align:start position:0% +only you get the resolution for each of +those colors since they're separated + + align:start position:0% +those colors since they're separated + + + align:start position:0% +those colors since they're separated +into space by the other colors being in + + align:start position:0% +into space by the other colors being in + + + align:start position:0% +into space by the other colors being in +space as well + + align:start position:0% +space as well + + + align:start position:0% +space as well +so in this four megapixel they're only + + align:start position:0% +so in this four megapixel they're only + + + align:start position:0% +so in this four megapixel they're only +four million pixels stored yeah + + align:start position:0% +four million pixels stored yeah + + + align:start position:0% +four million pixels stored yeah +and then our channel two megapixels are + + align:start position:0% +and then our channel two megapixels are + + + align:start position:0% +and then our channel two megapixels are +green one megapixel thread and one + + align:start position:0% +green one megapixel thread and one + + + align:start position:0% +green one megapixel thread and one +megapixels + + align:start position:0% +megapixels + + + align:start position:0% +megapixels +and so what's the benefit of + + align:start position:0% +and so what's the benefit of + + + align:start position:0% +and so what's the benefit of +if you compare this with the previous + + align:start position:0% +if you compare this with the previous + + + align:start position:0% +if you compare this with the previous +design + + align:start position:0% +design + + + align:start position:0% +design +where you had three separate + + align:start position:0% +where you had three separate + + + align:start position:0% +where you had three separate +ccds one for each color + + align:start position:0% +ccds one for each color + + + align:start position:0% +ccds one for each color +what's the benefit and what's the + + align:start position:0% +what's the benefit and what's the + + + align:start position:0% +what's the benefit and what's the +disadvantage money + + align:start position:0% +disadvantage money + + + align:start position:0% +disadvantage money +cheaper it's cheaper right yeah why is + + align:start position:0% +cheaper it's cheaper right yeah why is + + + align:start position:0% +cheaper it's cheaper right yeah why is +it cheaper + + align:start position:0% + + + + align:start position:0% + +less optics + + align:start position:0% +less optics + + + align:start position:0% +less optics +less optics + + align:start position:0% +less optics + + + align:start position:0% +less optics +alignment + + align:start position:0% +alignment + + + align:start position:0% +alignment +alignment is easy what are the what's + + align:start position:0% +alignment is easy what are the what's + + + align:start position:0% +alignment is easy what are the what's +the disadvantage though + + align:start position:0% +the disadvantage though + + + align:start position:0% +the disadvantage though +less you're blocking more right + + align:start position:0% +less you're blocking more right + + + align:start position:0% +less you're blocking more right +you're getting + + align:start position:0% +you're getting + + + align:start position:0% +you're getting +effectively getting one third the light + + align:start position:0% +effectively getting one third the light + + + align:start position:0% +effectively getting one third the light +because every time you sense + + align:start position:0% +because every time you sense + + + align:start position:0% +because every time you sense +one color + + align:start position:0% +one color + + + align:start position:0% +one color +the light for other two colors is being + + align:start position:0% +the light for other two colors is being + + + align:start position:0% +the light for other two colors is being +thrown out + + align:start position:0% +thrown out + + + align:start position:0% +thrown out +and when when mike talks about a little + + align:start position:0% +and when when mike talks about a little + + + align:start position:0% +and when when mike talks about a little +bit later about some other + + align:start position:0% +bit later about some other + + + align:start position:0% +bit later about some other +multi-spectral cameras + + align:start position:0% +multi-spectral cameras + + + align:start position:0% +multi-spectral cameras +this will become the biggest issue + + align:start position:0% +this will become the biggest issue + + + align:start position:0% +this will become the biggest issue +of the notion of throwing away light + + align:start position:0% +of the notion of throwing away light + + + align:start position:0% +of the notion of throwing away light +and also can you + + align:start position:0% +and also can you + + + align:start position:0% +and also can you +perfectly reconstruct the image right so + + align:start position:0% +perfectly reconstruct the image right so + + + align:start position:0% +perfectly reconstruct the image right so +there's always an issue + + align:start position:0% +there's always an issue + + + align:start position:0% +there's always an issue +so most of the reconstruction + + align:start position:0% +so most of the reconstruction + + + align:start position:0% +so most of the reconstruction +that interpolation that we just talked + + align:start position:0% +that interpolation that we just talked + + + align:start position:0% +that interpolation that we just talked +about + + align:start position:0% +about + + + align:start position:0% +about +is based on some + + align:start position:0% +is based on some + + + align:start position:0% +is based on some +assumption about the natural scene + + align:start position:0% +assumption about the natural scene + + + align:start position:0% +assumption about the natural scene +but if you if your scene is not natural + + align:start position:0% +but if you if your scene is not natural + + + align:start position:0% +but if you if your scene is not natural +maybe it's + + align:start position:0% +maybe it's + + + align:start position:0% +maybe it's +a black and white + + align:start position:0% +a black and white + + + align:start position:0% +a black and white +text + + align:start position:0% +text + + + align:start position:0% +text +or you have very fine stripes on your + + align:start position:0% +or you have very fine stripes on your + + + align:start position:0% +or you have very fine stripes on your +shirt + + align:start position:0% +shirt + + + align:start position:0% +shirt +in that case the interpolation will not + + align:start position:0% +in that case the interpolation will not + + + align:start position:0% +in that case the interpolation will not +give you the right results and you see + + align:start position:0% +give you the right results and you see + + + align:start position:0% +give you the right results and you see +it often you can see this strange more + + align:start position:0% +it often you can see this strange more + + + align:start position:0% +it often you can see this strange more +air pattern + + align:start position:0% +air pattern + + + align:start position:0% +air pattern +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +so one of the things you they do in + + align:start position:0% +so one of the things you they do in + + + align:start position:0% +so one of the things you they do in +order to avoid this kind of thing is + + align:start position:0% +order to avoid this kind of thing is + + + align:start position:0% +order to avoid this kind of thing is +that they place a low pass filter + + align:start position:0% +that they place a low pass filter + + + align:start position:0% +that they place a low pass filter +immediately on top of the sensor so that + + align:start position:0% +immediately on top of the sensor so that + + + align:start position:0% +immediately on top of the sensor so that +you get rid of any such high frequency + + align:start position:0% +you get rid of any such high frequency + + + align:start position:0% +you get rid of any such high frequency +details in a single color + + align:start position:0% +details in a single color + + + align:start position:0% +details in a single color +and but still you get i mean in many of + + align:start position:0% +and but still you get i mean in many of + + + align:start position:0% +and but still you get i mean in many of +these images you do see color mode so + + align:start position:0% +these images you do see color mode so + + + align:start position:0% +these images you do see color mode so +you have some some weird artifacts in in + + align:start position:0% +you have some some weird artifacts in in + + + align:start position:0% +you have some some weird artifacts in in +one color channel and not in the others + + align:start position:0% +one color channel and not in the others + + + align:start position:0% +one color channel and not in the others +or + + align:start position:0% +or + + + align:start position:0% +or +a rainbow sort of effect and that shows + + align:start position:0% +a rainbow sort of effect and that shows + + + align:start position:0% +a rainbow sort of effect and that shows +up especially along near the edges and + + align:start position:0% +up especially along near the edges and + + + align:start position:0% +up especially along near the edges and +so on + + align:start position:0% +so on + + + align:start position:0% +so on +someone did someone have a question + + align:start position:0% + + + + align:start position:0% + +so one of the things as + + align:start position:0% +so one of the things as + + + align:start position:0% +so one of the things as +ramesh mentioned is that you are + + align:start position:0% +ramesh mentioned is that you are + + + align:start position:0% +ramesh mentioned is that you are +throwing away one third or two thirds of + + align:start position:0% +throwing away one third or two thirds of + + + align:start position:0% +throwing away one third or two thirds of +the light in doing the previous one so + + align:start position:0% +the light in doing the previous one so + + + align:start position:0% +the light in doing the previous one so +there is this recent pattern that nikon + + align:start position:0% +there is this recent pattern that nikon + + + align:start position:0% +there is this recent pattern that nikon +recently introduced where what they're + + align:start position:0% +recently introduced where what they're + + + align:start position:0% +recently introduced where what they're +doing is sort of combining these two + + align:start position:0% +doing is sort of combining these two + + + align:start position:0% +doing is sort of combining these two +notions that we just discussed they have + + align:start position:0% +notions that we just discussed they have + + + align:start position:0% +notions that we just discussed they have +they have these red green and blue + + align:start position:0% +they have these red green and blue + + + align:start position:0% +they have these red green and blue +sensors uh at the pixel level but they + + align:start position:0% +sensors uh at the pixel level but they + + + align:start position:0% +sensors uh at the pixel level but they +instead of using three separate filters + + align:start position:0% +instead of using three separate filters + + + align:start position:0% +instead of using three separate filters +they use dichroic mirrors in order to + + align:start position:0% +they use dichroic mirrors in order to + + + align:start position:0% +they use dichroic mirrors in order to +separate the light that's falling on the + + align:start position:0% +separate the light that's falling on the + + + align:start position:0% +separate the light that's falling on the +sensor into the + + align:start position:0% +sensor into the + + + align:start position:0% +sensor into the +rg and the component so it's similar to + + align:start position:0% +rg and the component so it's similar to + + + align:start position:0% +rg and the component so it's similar to +the first three ccd case that they're + + align:start position:0% +the first three ccd case that they're + + + align:start position:0% +the first three ccd case that they're +using dichroic mirrors they're not + + align:start position:0% +using dichroic mirrors they're not + + + align:start position:0% +using dichroic mirrors they're not +losing any light but it's all happening + + align:start position:0% +losing any light but it's all happening + + + align:start position:0% +losing any light but it's all happening +at the sensor level so conceivably they + + align:start position:0% +at the sensor level so conceivably they + + + align:start position:0% +at the sensor level so conceivably they +can build this thing in the + + align:start position:0% +can build this thing in the + + + align:start position:0% +can build this thing in the +semiconductor itself and so it's much + + align:start position:0% +semiconductor itself and so it's much + + + align:start position:0% +semiconductor itself and so it's much +cheaper than using prisms outside + + align:start position:0% + + + + align:start position:0% + +everybody familiar with the dichroic + + align:start position:0% +everybody familiar with the dichroic + + + align:start position:0% +everybody familiar with the dichroic +dichroic materials + + align:start position:0% + + + + align:start position:0% + +it's basically a type of in simplest + + align:start position:0% +it's basically a type of in simplest + + + align:start position:0% +it's basically a type of in simplest +words it's a tank of a glass + + align:start position:0% +words it's a tank of a glass + + + align:start position:0% +words it's a tank of a glass +where + + align:start position:0% +where + + + align:start position:0% +where +um at the right angle + + align:start position:0% +um at the right angle + + + align:start position:0% +um at the right angle +if you shine light at the right angle + + align:start position:0% +if you shine light at the right angle + + + align:start position:0% +if you shine light at the right angle +a particular wavelength will pass + + align:start position:0% +a particular wavelength will pass + + + align:start position:0% +a particular wavelength will pass +through + + align:start position:0% +through + + + align:start position:0% +through +and all other wavelengths will be + + align:start position:0% +and all other wavelengths will be + + + align:start position:0% +and all other wavelengths will be +reflected + + align:start position:0% +reflected + + + align:start position:0% +reflected +so it's essentially i think it's total + + align:start position:0% +so it's essentially i think it's total + + + align:start position:0% +so it's essentially i think it's total +internal reflection is what it makes use + + align:start position:0% +internal reflection is what it makes use + + + align:start position:0% +internal reflection is what it makes use +of and the threshold is different for + + align:start position:0% +of and the threshold is different for + + + align:start position:0% +of and the threshold is different for +different wavelengths of when the light + + align:start position:0% +different wavelengths of when the light + + + align:start position:0% +different wavelengths of when the light +is going to get total internal reflected + + align:start position:0% +is going to get total internal reflected + + + align:start position:0% +is going to get total internal reflected +or just keep going straight into the + + align:start position:0% +or just keep going straight into the + + + align:start position:0% +or just keep going straight into the +next material and using a series of such + + align:start position:0% +next material and using a series of such + + + align:start position:0% +next material and using a series of such +mirrors they can separate the three + + align:start position:0% +mirrors they can separate the three + + + align:start position:0% +mirrors they can separate the three +wetlands and in the break we'll have the + + align:start position:0% +wetlands and in the break we'll have the + + + align:start position:0% +wetlands and in the break we'll have the +soap bubbles and they will demonstrate + + align:start position:0% +soap bubbles and they will demonstrate + + + align:start position:0% +soap bubbles and they will demonstrate +the same concept + + align:start position:0% + + + + align:start position:0% + +so one other popular um semi popular + + align:start position:0% +so one other popular um semi popular + + + align:start position:0% +so one other popular um semi popular +sort of sensor design is the what's + + align:start position:0% +sort of sensor design is the what's + + + align:start position:0% +sort of sensor design is the what's +called the phobion x3 sensor and instead + + align:start position:0% +called the phobion x3 sensor and instead + + + align:start position:0% +called the phobion x3 sensor and instead +of using three separate pics each pixel + + align:start position:0% +of using three separate pics each pixel + + + align:start position:0% +of using three separate pics each pixel +having a different filter on top of that + + align:start position:0% +having a different filter on top of that + + + align:start position:0% +having a different filter on top of that +the design of this sensor is very + + align:start position:0% +the design of this sensor is very + + + align:start position:0% +the design of this sensor is very +similar to that which is used in film so + + align:start position:0% +similar to that which is used in film so + + + align:start position:0% +similar to that which is used in film so +they + + align:start position:0% +they + + + align:start position:0% +they +in film they actually have three + + align:start position:0% +in film they actually have three + + + align:start position:0% +in film they actually have three +separate uh + + align:start position:0% +separate uh + + + align:start position:0% +separate uh +emulsions or three or four separate + + align:start position:0% +emulsions or three or four separate + + + align:start position:0% +emulsions or three or four separate +layers of emulsions each + + align:start position:0% +layers of emulsions each + + + align:start position:0% +layers of emulsions each +sensitive to a different wavelength of + + align:start position:0% +sensitive to a different wavelength of + + + align:start position:0% +sensitive to a different wavelength of +light and similarly over here they have + + align:start position:0% +light and similarly over here they have + + + align:start position:0% +light and similarly over here they have +as you keep going down deeper into the + + align:start position:0% +as you keep going down deeper into the + + + align:start position:0% +as you keep going down deeper into the +pixel different + + align:start position:0% +pixel different + + + align:start position:0% +pixel different +depths of the pixel actually are + + align:start position:0% +depths of the pixel actually are + + + align:start position:0% +depths of the pixel actually are +sensitive to different wavelengths of + + align:start position:0% +sensitive to different wavelengths of + + + align:start position:0% +sensitive to different wavelengths of +light so the top region is sensitive + + align:start position:0% +light so the top region is sensitive + + + align:start position:0% +light so the top region is sensitive +more sensitive to glue and the next + + align:start position:0% +more sensitive to glue and the next + + + align:start position:0% +more sensitive to glue and the next +part to green and and the bottom most is + + align:start position:0% +part to green and and the bottom most is + + + align:start position:0% +part to green and and the bottom most is +to red and + + align:start position:0% +to red and + + + align:start position:0% +to red and +so a single pixel can actually sense all + + align:start position:0% +so a single pixel can actually sense all + + + align:start position:0% +so a single pixel can actually sense all +three colors all three wavelengths as as + + align:start position:0% +three colors all three wavelengths as as + + + align:start position:0% +three colors all three wavelengths as as +they're falling down on it and + + align:start position:0% +they're falling down on it and + + + align:start position:0% +they're falling down on it and +the advantage is that you don't need to + + align:start position:0% +the advantage is that you don't need to + + + align:start position:0% +the advantage is that you don't need to +put uh + + align:start position:0% +put uh + + + align:start position:0% +put uh +put this low pass filter on top of it + + align:start position:0% +put this low pass filter on top of it + + + align:start position:0% +put this low pass filter on top of it +because instead of doing the spatial + + align:start position:0% +because instead of doing the spatial + + + align:start position:0% +because instead of doing the spatial +sort of multiplexing you're doing this + + align:start position:0% +sort of multiplexing you're doing this + + + align:start position:0% +sort of multiplexing you're doing this +multiplexing in depth so that's a big + + align:start position:0% +multiplexing in depth so that's a big + + + align:start position:0% +multiplexing in depth so that's a big +advantage + + align:start position:0% +advantage + + + align:start position:0% +advantage +in terms of the resolution yes you do + + align:start position:0% +in terms of the resolution yes you do + + + align:start position:0% +in terms of the resolution yes you do +get + + align:start position:0% +get + + + align:start position:0% +get +you don't lose the resolution like you + + align:start position:0% +you don't lose the resolution like you + + + align:start position:0% +you don't lose the resolution like you +do in the case of a bare filter + + align:start position:0% +do in the case of a bare filter + + + align:start position:0% +do in the case of a bare filter +but so far the + + align:start position:0% +but so far the + + + align:start position:0% +but so far the +when they quote the number of pixels + + align:start position:0% +when they quote the number of pixels + + + align:start position:0% +when they quote the number of pixels +that they have they simply multiplied by + + align:start position:0% +that they have they simply multiplied by + + + align:start position:0% +that they have they simply multiplied by +three so when + + align:start position:0% +three so when + + + align:start position:0% +three so when +sigma is a manufacturer that + + align:start position:0% +sigma is a manufacturer that + + + align:start position:0% +sigma is a manufacturer that +manufactures these four von sensors now + + align:start position:0% +manufactures these four von sensors now + + + align:start position:0% +manufactures these four von sensors now +they bought over four vm so when they + + align:start position:0% +they bought over four vm so when they + + + align:start position:0% +they bought over four vm so when they +say they have a 12 megapixel sensor it's + + align:start position:0% +say they have a 12 megapixel sensor it's + + + align:start position:0% +say they have a 12 megapixel sensor it's +really a four megapixel sensor they just + + align:start position:0% +really a four megapixel sensor they just + + + align:start position:0% +really a four megapixel sensor they just +call it a 12 megapixel sensor because + + align:start position:0% +call it a 12 megapixel sensor because + + + align:start position:0% +call it a 12 megapixel sensor because +there are three elements for each pixel + + align:start position:0% +there are three elements for each pixel + + + align:start position:0% +there are three elements for each pixel +so + + align:start position:0% +so + + + align:start position:0% +so +it's not clear whether that's really + + align:start position:0% +it's not clear whether that's really + + + align:start position:0% +it's not clear whether that's really +again in in terms of the resolution but + + align:start position:0% +again in in terms of the resolution but + + + align:start position:0% +again in in terms of the resolution but +a definite gain is that you don't need a + + align:start position:0% +a definite gain is that you don't need a + + + align:start position:0% +a definite gain is that you don't need a +low pass filter over it so you don't get + + align:start position:0% +low pass filter over it so you don't get + + + align:start position:0% +low pass filter over it so you don't get +these + + align:start position:0% +these + + + align:start position:0% +these +you get uh you you're able to capture + + align:start position:0% +you get uh you you're able to capture + + + align:start position:0% +you get uh you you're able to capture +much higher frequency information so you + + align:start position:0% +much higher frequency information so you + + + align:start position:0% +much higher frequency information so you +can't win either way right if you when + + align:start position:0% +can't win either way right if you when + + + align:start position:0% +can't win either way right if you when +it says 4 megapixel traditional camera + + align:start position:0% +it says 4 megapixel traditional camera + + + align:start position:0% +it says 4 megapixel traditional camera +makers you only get a 2 megapixel green + + align:start position:0% +makers you only get a 2 megapixel green + + + align:start position:0% +makers you only get a 2 megapixel green +image right and where they say it's 12 + + align:start position:0% +image right and where they say it's 12 + + + align:start position:0% +image right and where they say it's 12 +megapixel + + align:start position:0% +megapixel + + + align:start position:0% +megapixel +right you still get a 4 megapixel green + + align:start position:0% +right you still get a 4 megapixel green + + + align:start position:0% +right you still get a 4 megapixel green +image right + + align:start position:0% +image right + + + align:start position:0% +image right +but one other disadvantage of this is + + align:start position:0% +but one other disadvantage of this is + + + align:start position:0% +but one other disadvantage of this is +that unlike the previous case where you + + align:start position:0% +that unlike the previous case where you + + + align:start position:0% +that unlike the previous case where you +you can almost arbitrarily choose what + + align:start position:0% +you can almost arbitrarily choose what + + + align:start position:0% +you can almost arbitrarily choose what +filter you want over each uh each pixel + + align:start position:0% +filter you want over each uh each pixel + + + align:start position:0% +filter you want over each uh each pixel +in this case the separation between the + + align:start position:0% +in this case the separation between the + + + align:start position:0% +in this case the separation between the +red green and blue channels is not as + + align:start position:0% +red green and blue channels is not as + + + align:start position:0% +red green and blue channels is not as +great you don't they they apparently + + align:start position:0% +great you don't they they apparently + + + align:start position:0% +great you don't they they apparently +don't have as much control so they need + + align:start position:0% +don't have as much control so they need + + + align:start position:0% +don't have as much control so they need +to do a lot of software processing on + + align:start position:0% +to do a lot of software processing on + + + align:start position:0% +to do a lot of software processing on +the image that's captured in order to + + align:start position:0% +the image that's captured in order to + + + align:start position:0% +the image that's captured in order to +separate the red green and blue and + + align:start position:0% +separate the red green and blue and + + + align:start position:0% +separate the red green and blue and +possibly they're doing some sort of + + align:start position:0% +possibly they're doing some sort of + + + align:start position:0% +possibly they're doing some sort of +that works based on some sort of image + + align:start position:0% +that works based on some sort of image + + + align:start position:0% +that works based on some sort of image +prior so you would have some image + + align:start position:0% +prior so you would have some image + + + align:start position:0% +prior so you would have some image +artifacts over there which might not be + + align:start position:0% +artifacts over there which might not be + + + align:start position:0% +artifacts over there which might not be +these more artifacts but you'll have + + align:start position:0% +these more artifacts but you'll have + + + align:start position:0% +these more artifacts but you'll have +some color artifacts + + align:start position:0% +some color artifacts + + + align:start position:0% +some color artifacts +and the actual profile is + + align:start position:0% +and the actual profile is + + + align:start position:0% +and the actual profile is +is very misleading because when you see + + align:start position:0% +is very misleading because when you see + + + align:start position:0% +is very misleading because when you see +this + + align:start position:0% +this + + + align:start position:0% +this +diagram on the left + + align:start position:0% +diagram on the left + + + align:start position:0% +diagram on the left +the blue is basically getting everything + + align:start position:0% +the blue is basically getting everything + + + align:start position:0% +the blue is basically getting everything +so it's something like + + align:start position:0% + + + + align:start position:0% + +this is your + + align:start position:0% +this is your + + + align:start position:0% +this is your +blue green and red then the blue pixel + + align:start position:0% +blue green and red then the blue pixel + + + align:start position:0% +blue green and red then the blue pixel +is getting almost everything + + align:start position:0% +is getting almost everything + + + align:start position:0% +is getting almost everything +and the green pixel is getting a little + + align:start position:0% +and the green pixel is getting a little + + + align:start position:0% +and the green pixel is getting a little +bit less + + align:start position:0% +bit less + + + align:start position:0% +bit less +and the red pixel is getting whatever + + align:start position:0% +and the red pixel is getting whatever + + + align:start position:0% +and the red pixel is getting whatever +remaining is + + align:start position:0% + + + + align:start position:0% + +so it's not it's not like blue green and + + align:start position:0% +so it's not it's not like blue green and + + + align:start position:0% +so it's not it's not like blue green and +red + + align:start position:0% +red + + + align:start position:0% +red +so that the picture on the right is + + align:start position:0% +so that the picture on the right is + + + align:start position:0% +so that the picture on the right is +completely misleading + + align:start position:0% +completely misleading + + + align:start position:0% +completely misleading +it's it's getting some three values that + + align:start position:0% +it's it's getting some three values that + + + align:start position:0% +it's it's getting some three values that +are highly overlapped and from that they + + align:start position:0% +are highly overlapped and from that they + + + align:start position:0% +are highly overlapped and from that they +are going to do some inversion and + + align:start position:0% +are going to do some inversion and + + + align:start position:0% +are going to do some inversion and +figure out archipelago + + align:start position:0% +figure out archipelago + + + align:start position:0% +figure out archipelago +so + + align:start position:0% +so + + + align:start position:0% +so +in the very simplest words you can think + + align:start position:0% +in the very simplest words you can think + + + align:start position:0% +in the very simplest words you can think +of the first one gets + + align:start position:0% +of the first one gets + + + align:start position:0% +of the first one gets +everything + + align:start position:0% +everything + + + align:start position:0% +everything +the second one gets just this and the + + align:start position:0% +the second one gets just this and the + + + align:start position:0% +the second one gets just this and the +last one gets this + + align:start position:0% +last one gets this + + + align:start position:0% +last one gets this +and from that they can figure out + + align:start position:0% +and from that they can figure out + + + align:start position:0% +and from that they can figure out +what + + align:start position:0% +what + + + align:start position:0% +what +red green blue is + + align:start position:0% + + + + align:start position:0% + +so uh i should also say that there is + + align:start position:0% +so uh i should also say that there is + + + align:start position:0% +so uh i should also say that there is +there's nothing really holy about this + + align:start position:0% +there's nothing really holy about this + + + align:start position:0% +there's nothing really holy about this +rgb design it's just that this was the + + align:start position:0% +rgb design it's just that this was the + + + align:start position:0% +rgb design it's just that this was the +one that was proposed first and this is + + align:start position:0% +one that was proposed first and this is + + + align:start position:0% +one that was proposed first and this is +what's being used it's the most common + + align:start position:0% +what's being used it's the most common + + + align:start position:0% +what's being used it's the most common +but there are a whole number of other + + align:start position:0% +but there are a whole number of other + + + align:start position:0% +but there are a whole number of other +so-called bear patterns that that have + + align:start position:0% +so-called bear patterns that that have + + + align:start position:0% +so-called bear patterns that that have +been proposed + + align:start position:0% +been proposed + + + align:start position:0% +been proposed +which don't use this 2x2 tile they have + + align:start position:0% +which don't use this 2x2 tile they have + + + align:start position:0% +which don't use this 2x2 tile they have +even bigger tiles and the simplest one + + align:start position:0% +even bigger tiles and the simplest one + + + align:start position:0% +even bigger tiles and the simplest one +is red green and blue and clear so you + + align:start position:0% +is red green and blue and clear so you + + + align:start position:0% +is red green and blue and clear so you +get one pixel which gets all the + + align:start position:0% +get one pixel which gets all the + + + align:start position:0% +get one pixel which gets all the +wavelengths and then red green and blue + + align:start position:0% +wavelengths and then red green and blue + + + align:start position:0% +wavelengths and then red green and blue +and interpolations + + align:start position:0% +and interpolations + + + align:start position:0% +and interpolations +i'm i'm sure + + align:start position:0% +i'm i'm sure + + + align:start position:0% +i'm i'm sure +there are studies that compare various + + align:start position:0% +there are studies that compare various + + + align:start position:0% +there are studies that compare various +ones because if you don't get rgb you + + align:start position:0% +ones because if you don't get rgb you + + + align:start position:0% +ones because if you don't get rgb you +need to do some sort of inversion and + + align:start position:0% +need to do some sort of inversion and + + + align:start position:0% +need to do some sort of inversion and +you would get noise in that inversion + + align:start position:0% +you would get noise in that inversion + + + align:start position:0% +you would get noise in that inversion +but if you use let's say cmy cyan + + align:start position:0% +but if you use let's say cmy cyan + + + align:start position:0% +but if you use let's say cmy cyan +magenta yellow you would be able to get + + align:start position:0% +magenta yellow you would be able to get + + + align:start position:0% +magenta yellow you would be able to get +more light onto the sensor + + align:start position:0% +more light onto the sensor + + + align:start position:0% +more light onto the sensor +so i'm not very sure of i mean i + + align:start position:0% +so i'm not very sure of i mean i + + + align:start position:0% +so i'm not very sure of i mean i +couldn't find any real studies that + + align:start position:0% +couldn't find any real studies that + + + align:start position:0% +couldn't find any real studies that +compare the various sensors or various + + align:start position:0% +compare the various sensors or various + + + align:start position:0% +compare the various sensors or various +yeah kodak has done a few studies they + + align:start position:0% +yeah kodak has done a few studies they + + + align:start position:0% +yeah kodak has done a few studies they +haven't done the version they do yeah i + + align:start position:0% +haven't done the version they do yeah i + + + align:start position:0% +haven't done the version they do yeah i +mean it was always very + + align:start position:0% +mean it was always very + + + align:start position:0% +mean it was always very +i'm not sure so yeah so there are + + align:start position:0% +i'm not sure so yeah so there are + + + align:start position:0% +i'm not sure so yeah so there are +various trade-offs between the different + + align:start position:0% +various trade-offs between the different + + + align:start position:0% +various trade-offs between the different +kind of sensors but this is the only one + + align:start position:0% +kind of sensors but this is the only one + + + align:start position:0% +kind of sensors but this is the only one +that you find in practice right now this + + align:start position:0% +that you find in practice right now this + + + align:start position:0% +that you find in practice right now this +would be a great class project by the + + align:start position:0% +would be a great class project by the + + + align:start position:0% +would be a great class project by the +way of figuring out which spectrum to + + align:start position:0% +way of figuring out which spectrum to + + + align:start position:0% +way of figuring out which spectrum to +choose depending on the scene + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so uh taking a step back from this was + + align:start position:0% +so uh taking a step back from this was + + + align:start position:0% +so uh taking a step back from this was +more sort of a rehashing of what we + + align:start position:0% +more sort of a rehashing of what we + + + align:start position:0% +more sort of a rehashing of what we +already discussed before in terms of + + align:start position:0% +already discussed before in terms of + + + align:start position:0% +already discussed before in terms of +color sensing on on cameras + + align:start position:0% +color sensing on on cameras + + + align:start position:0% +color sensing on on cameras +it's important to look at what we are + + align:start position:0% +it's important to look at what we are + + + align:start position:0% +it's important to look at what we are +sensing when we sense light and it's + + align:start position:0% +sensing when we sense light and it's + + + align:start position:0% +sensing when we sense light and it's +really a part of what's the + + align:start position:0% +really a part of what's the + + + align:start position:0% +really a part of what's the +electromagnetic spectrum that + + align:start position:0% +electromagnetic spectrum that + + + align:start position:0% +electromagnetic spectrum that +that + + align:start position:0% +that + + + align:start position:0% +that +is actually much much wider and has many + + align:start position:0% +is actually much much wider and has many + + + align:start position:0% +is actually much much wider and has many +other types of rays than what we are + + align:start position:0% +other types of rays than what we are + + + align:start position:0% +other types of rays than what we are +usually looking at in photography which + + align:start position:0% +usually looking at in photography which + + + align:start position:0% +usually looking at in photography which +is a visible spectrum and + + align:start position:0% +is a visible spectrum and + + + align:start position:0% +is a visible spectrum and +the visible spectrum of light goes from + + align:start position:0% +the visible spectrum of light goes from + + + align:start position:0% +the visible spectrum of light goes from +400 to 700 nanometers usually when you + + align:start position:0% +400 to 700 nanometers usually when you + + + align:start position:0% +400 to 700 nanometers usually when you +talk about light you talk in very in + + align:start position:0% +talk about light you talk in very in + + + align:start position:0% +talk about light you talk in very in +terms of wavelength + + align:start position:0% +terms of wavelength + + + align:start position:0% +terms of wavelength +and in different like in radio and + + align:start position:0% +and in different like in radio and + + + align:start position:0% +and in different like in radio and +microwave you would probably talk in + + align:start position:0% +microwave you would probably talk in + + + align:start position:0% +microwave you would probably talk in +terms of frequency or a tetrahedral + + align:start position:0% +terms of frequency or a tetrahedral + + + align:start position:0% +terms of frequency or a tetrahedral +radiation and so on but it's + + align:start position:0% +radiation and so on but it's + + + align:start position:0% +radiation and so on but it's +in for visible light you always say the + + align:start position:0% +in for visible light you always say the + + + align:start position:0% +in for visible light you always say the +wavelength it's 400 to 700 nanometers + + align:start position:0% +wavelength it's 400 to 700 nanometers + + + align:start position:0% +wavelength it's 400 to 700 nanometers +going from group from blue to red and + + align:start position:0% +going from group from blue to red and + + + align:start position:0% +going from group from blue to red and +it's interesting that this is really the + + align:start position:0% +it's interesting that this is really the + + + align:start position:0% +it's interesting that this is really the +only wavelength region that is + + align:start position:0% +only wavelength region that is + + + align:start position:0% +only wavelength region that is +almost completely the atmosphere is + + align:start position:0% +almost completely the atmosphere is + + + align:start position:0% +almost completely the atmosphere is +almost completely transparent to it so + + align:start position:0% +almost completely transparent to it so + + + align:start position:0% +almost completely transparent to it so +the sunlight that comes through is it's + + align:start position:0% +the sunlight that comes through is it's + + + align:start position:0% +the sunlight that comes through is it's +other than maybe radio wheels almost all + + align:start position:0% +other than maybe radio wheels almost all + + + align:start position:0% +other than maybe radio wheels almost all +other + + align:start position:0% +other + + + align:start position:0% +other +wavelengths are actually occluded by the + + align:start position:0% +wavelengths are actually occluded by the + + + align:start position:0% +wavelengths are actually occluded by the +atmosphere and this is really the most + + align:start position:0% +atmosphere and this is really the most + + + align:start position:0% +atmosphere and this is really the most +of the of the natural illumination that + + align:start position:0% +of the of the natural illumination that + + + align:start position:0% +of the of the natural illumination that +you have is in this wavelength region + + align:start position:0% +you have is in this wavelength region + + + align:start position:0% +you have is in this wavelength region +which is probably why humans and most + + align:start position:0% +which is probably why humans and most + + + align:start position:0% +which is probably why humans and most +animals actually develop their + + align:start position:0% +animals actually develop their + + + align:start position:0% +animals actually develop their +uh + + align:start position:0% +uh + + + align:start position:0% +uh +are tuned for this region and not any + + align:start position:0% +are tuned for this region and not any + + + align:start position:0% +are tuned for this region and not any +other + + align:start position:0% +other + + + align:start position:0% +other +and another sort of interesting thing is + + align:start position:0% +and another sort of interesting thing is + + + align:start position:0% +and another sort of interesting thing is +as you keep going away from this or + + align:start position:0% +as you keep going away from this or + + + align:start position:0% +as you keep going away from this or +shorter wavelength the more dangerous + + align:start position:0% +shorter wavelength the more dangerous + + + align:start position:0% +shorter wavelength the more dangerous +sort of the wave becomes already + + align:start position:0% +sort of the wave becomes already + + + align:start position:0% +sort of the wave becomes already +starting from uv you start getting + + align:start position:0% +starting from uv you start getting + + + align:start position:0% +starting from uv you start getting +cancerous rays and and so on and then + + align:start position:0% +cancerous rays and and so on and then + + + align:start position:0% +cancerous rays and and so on and then +x-rays and gamma rays are even more so + + align:start position:0% +x-rays and gamma rays are even more so + + + align:start position:0% +x-rays and gamma rays are even more so +but if you go for larger wavelengths + + align:start position:0% +but if you go for larger wavelengths + + + align:start position:0% +but if you go for larger wavelengths +they are usually harmless and the way to + + align:start position:0% +they are usually harmless and the way to + + + align:start position:0% +they are usually harmless and the way to +remember that is + + align:start position:0% +remember that is + + + align:start position:0% +remember that is +you know wavelength is inversely + + align:start position:0% +you know wavelength is inversely + + + align:start position:0% +you know wavelength is inversely +proportional to the frequency + + align:start position:0% +proportional to the frequency + + + align:start position:0% +proportional to the frequency +and the product of the two what's the + + align:start position:0% +and the product of the two what's the + + + align:start position:0% +and the product of the two what's the +number when you multiply the wavelength + + align:start position:0% +number when you multiply the wavelength + + + align:start position:0% +number when you multiply the wavelength +of + + align:start position:0% +of + + + align:start position:0% +of +spectrum to the frequency of the + + align:start position:0% +spectrum to the frequency of the + + + align:start position:0% +spectrum to the frequency of the +spectrum + + align:start position:0% + + + + align:start position:0% + +that's the speed of light right what's + + align:start position:0% +that's the speed of light right what's + + + align:start position:0% +that's the speed of light right what's +the speed of light + + align:start position:0% + + + + align:start position:0% + +three times + + align:start position:0% +three times + + + align:start position:0% +three times +ten to the eight meters per second + + align:start position:0% +ten to the eight meters per second + + + align:start position:0% +ten to the eight meters per second +square right in this class per second + + align:start position:0% +square right in this class per second + + + align:start position:0% +square right in this class per second +foot per second one foot per second + + align:start position:0% +foot per second one foot per second + + + align:start position:0% +foot per second one foot per second +very good and um + + align:start position:0% +very good and um + + + align:start position:0% +very good and um +so the frequency is increasing as you go + + align:start position:0% +so the frequency is increasing as you go + + + align:start position:0% +so the frequency is increasing as you go +to the right + + align:start position:0% +to the right + + + align:start position:0% +to the right +which means it has more energy h nu + + align:start position:0% +which means it has more energy h nu + + + align:start position:0% +which means it has more energy h nu +which means it can penetrate + + align:start position:0% +which means it can penetrate + + + align:start position:0% +which means it can penetrate +deeper and damage more things + + align:start position:0% +deeper and damage more things + + + align:start position:0% +deeper and damage more things +so that's one easy way to remember + + align:start position:0% +so that's one easy way to remember + + + align:start position:0% +so that's one easy way to remember +what's going on on the right + + align:start position:0% +what's going on on the right + + + align:start position:0% +what's going on on the right +unfortunately the chart is flipped + + align:start position:0% +unfortunately the chart is flipped + + + align:start position:0% +unfortunately the chart is flipped +because we should think of wavelength + + align:start position:0% +because we should think of wavelength + + + align:start position:0% +because we should think of wavelength +increasing from left to right but this + + align:start position:0% +increasing from left to right but this + + + align:start position:0% +increasing from left to right but this +is really showing the frequency + + align:start position:0% +is really showing the frequency + + + align:start position:0% +is really showing the frequency +increasing from left to right + + align:start position:0% + + + + align:start position:0% + +so yeah + + align:start position:0% +so yeah + + + align:start position:0% +so yeah +i guess the point i want to make here is + + align:start position:0% +i guess the point i want to make here is + + + align:start position:0% +i guess the point i want to make here is +that we are + + align:start position:0% +that we are + + + align:start position:0% +that we are +it's only this region that we are + + align:start position:0% +it's only this region that we are + + + align:start position:0% +it's only this region that we are +looking at which is really really small + + align:start position:0% +looking at which is really really small + + + align:start position:0% +looking at which is really really small +compared to the whole whole + + align:start position:0% +compared to the whole whole + + + align:start position:0% +compared to the whole whole +spectrum em spectrum and there is lots + + align:start position:0% +spectrum em spectrum and there is lots + + + align:start position:0% +spectrum em spectrum and there is lots +of interesting stuff going on especially + + align:start position:0% +of interesting stuff going on especially + + + align:start position:0% +of interesting stuff going on especially +in thermal ir and thermal and even + + align:start position:0% +in thermal ir and thermal and even + + + align:start position:0% +in thermal ir and thermal and even +even beyond that in using it for imaging + + align:start position:0% +even beyond that in using it for imaging + + + align:start position:0% +even beyond that in using it for imaging +and we heard uh + + align:start position:0% +and we heard uh + + + align:start position:0% +and we heard uh +using wi-fi for imaging also and things + + align:start position:0% +using wi-fi for imaging also and things + + + align:start position:0% +using wi-fi for imaging also and things +like that which is + + align:start position:0% +like that which is + + + align:start position:0% +like that which is +uh 2.4 gigahertz or something like that + + align:start position:0% +uh 2.4 gigahertz or something like that + + + align:start position:0% +uh 2.4 gigahertz or something like that +so you you don't have to be constrained + + align:start position:0% +so you you don't have to be constrained + + + align:start position:0% +so you you don't have to be constrained +for even creating a photorealistic or a + + align:start position:0% +for even creating a photorealistic or a + + + align:start position:0% +for even creating a photorealistic or a +visual image of understanding what's + + align:start position:0% +visual image of understanding what's + + + align:start position:0% +visual image of understanding what's +around us we + + align:start position:0% +around us we + + + align:start position:0% +around us we +we shouldn't be + + align:start position:0% +we shouldn't be + + + align:start position:0% +we shouldn't be +limited to visual uh sort of the visual + + align:start position:0% +limited to visual uh sort of the visual + + + align:start position:0% +limited to visual uh sort of the visual +spectrum it's it's okay to think outside + + align:start position:0% +spectrum it's it's okay to think outside + + + align:start position:0% +spectrum it's it's okay to think outside +it and i'll show a few examples of how + + align:start position:0% +it and i'll show a few examples of how + + + align:start position:0% +it and i'll show a few examples of how +thinking outside the visual spectrum + + align:start position:0% +thinking outside the visual spectrum + + + align:start position:0% +thinking outside the visual spectrum +actually enabled you to do a lot of + + align:start position:0% +actually enabled you to do a lot of + + + align:start position:0% +actually enabled you to do a lot of +things which you otherwise would not be + + align:start position:0% +things which you otherwise would not be + + + align:start position:0% +things which you otherwise would not be +able to do + + align:start position:0% +able to do + + + align:start position:0% +able to do +so uh before i get into that just uh + + align:start position:0% +so uh before i get into that just uh + + + align:start position:0% +so uh before i get into that just uh +wanted to talk about what a spectroscope + + align:start position:0% +wanted to talk about what a spectroscope + + + align:start position:0% +wanted to talk about what a spectroscope +is and we have one of those here so + + align:start position:0% +is and we have one of those here so + + + align:start position:0% +is and we have one of those here so +i guess you could pass it around and + + align:start position:0% +i guess you could pass it around and + + + align:start position:0% +i guess you could pass it around and +just look so you + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +what a spectroscope really is + + align:start position:0% +what a spectroscope really is + + + align:start position:0% +what a spectroscope really is +nothing but a prism essentially and a + + align:start position:0% +nothing but a prism essentially and a + + + align:start position:0% +nothing but a prism essentially and a +prism takes a single so a prism is + + align:start position:0% +prism takes a single so a prism is + + + align:start position:0% +prism takes a single so a prism is +basically uh this optical element that + + align:start position:0% +basically uh this optical element that + + + align:start position:0% +basically uh this optical element that +bends uh any incoming ray of light and + + align:start position:0% +bends uh any incoming ray of light and + + + align:start position:0% +bends uh any incoming ray of light and +but the interesting thing is because + + align:start position:0% +but the interesting thing is because + + + align:start position:0% +but the interesting thing is because +this is refraction the refractive index + + align:start position:0% +this is refraction the refractive index + + + align:start position:0% +this is refraction the refractive index +of class is actually slightly different + + align:start position:0% +of class is actually slightly different + + + align:start position:0% +of class is actually slightly different +based it's a function of the wavelength + + align:start position:0% +based it's a function of the wavelength + + + align:start position:0% +based it's a function of the wavelength +of light so if you build the a prism of + + align:start position:0% +of light so if you build the a prism of + + + align:start position:0% +of light so if you build the a prism of +the right material like the right kind + + align:start position:0% +the right material like the right kind + + + align:start position:0% +the right material like the right kind +of glass you can have it + + align:start position:0% +of glass you can have it + + + align:start position:0% +of glass you can have it +uh have a huge disparity in that in the + + align:start position:0% +uh have a huge disparity in that in the + + + align:start position:0% +uh have a huge disparity in that in the +refractive index between the 400 and 700 + + align:start position:0% +refractive index between the 400 and 700 + + + align:start position:0% +refractive index between the 400 and 700 +nanometers + + align:start position:0% +nanometers + + + align:start position:0% +nanometers +and so + + align:start position:0% +and so + + + align:start position:0% +and so +when the light bends coming out of a + + align:start position:0% +when the light bends coming out of a + + + align:start position:0% +when the light bends coming out of a +prism so it says grading here but can be + + align:start position:0% +prism so it says grading here but can be + + + align:start position:0% +prism so it says grading here but can be +a prism or creating any of those + + align:start position:0% +a prism or creating any of those + + + align:start position:0% +a prism or creating any of those +when when the light bends from here the + + align:start position:0% +when when the light bends from here the + + + align:start position:0% +when when the light bends from here the +red and + + align:start position:0% +red and + + + align:start position:0% +red and +blue + + align:start position:0% +blue + + + align:start position:0% +blue +red blue and green the different + + align:start position:0% +red blue and green the different + + + align:start position:0% +red blue and green the different +wavelengths actually bend in different + + align:start position:0% +wavelengths actually bend in different + + + align:start position:0% +wavelengths actually bend in different +directions and if you have a detector + + align:start position:0% +directions and if you have a detector + + + align:start position:0% +directions and if you have a detector +placed in front of it you can sense the + + align:start position:0% +placed in front of it you can sense the + + + align:start position:0% +placed in front of it you can sense the +intensity of the blue ray of the green + + align:start position:0% +intensity of the blue ray of the green + + + align:start position:0% +intensity of the blue ray of the green +ray and of the red dress separately and + + align:start position:0% +ray and of the red dress separately and + + + align:start position:0% +ray and of the red dress separately and +you can sort of decompose an incoming + + align:start position:0% +you can sort of decompose an incoming + + + align:start position:0% +you can sort of decompose an incoming +source of light into its constituents + + align:start position:0% +source of light into its constituents + + + align:start position:0% +source of light into its constituents +wavelengths you have a gradient yeah + + align:start position:0% +wavelengths you have a gradient yeah + + + align:start position:0% +wavelengths you have a gradient yeah +yeah so i'll pass this around and all + + align:start position:0% +yeah so i'll pass this around and all + + + align:start position:0% +yeah so i'll pass this around and all +you have to do is look through this hole + + align:start position:0% +you have to do is look through this hole + + + align:start position:0% +you have to do is look through this hole +here + + align:start position:0% +here + + + align:start position:0% +here +and all it has is a + + align:start position:0% +and all it has is a + + + align:start position:0% +and all it has is a +slit + + align:start position:0% +slit + + + align:start position:0% +slit +in front so + + align:start position:0% +in front so + + + align:start position:0% +in front so +the best fats found was to look at one + + align:start position:0% +the best fats found was to look at one + + + align:start position:0% +the best fats found was to look at one +of the bright lights + + align:start position:0% +of the bright lights + + + align:start position:0% +of the bright lights +up here and + + align:start position:0% +up here and + + + align:start position:0% +up here and +very conveniently there is a scale + + align:start position:0% +very conveniently there is a scale + + + align:start position:0% +very conveniently there is a scale +on this side that goes from 400 + + align:start position:0% +on this side that goes from 400 + + + align:start position:0% +on this side that goes from 400 +nanometers to 700 nanometers so the idea + + align:start position:0% +nanometers to 700 nanometers so the idea + + + align:start position:0% +nanometers to 700 nanometers so the idea +is that you can look at any point in the + + align:start position:0% +is that you can look at any point in the + + + align:start position:0% +is that you can look at any point in the +world and you can see its spectrum + + align:start position:0% +world and you can see its spectrum + + + align:start position:0% +world and you can see its spectrum +right away so unfortunately we don't + + align:start position:0% +right away so unfortunately we don't + + + align:start position:0% +right away so unfortunately we don't +have uh + + align:start position:0% +have uh + + + align:start position:0% +have uh +like fluorescent lights actually we do + + align:start position:0% + + + + align:start position:0% + +computers + + align:start position:0% +computers + + + align:start position:0% +computers +oh yeah + + align:start position:0% +oh yeah + + + align:start position:0% +oh yeah +good too + + align:start position:0% +good too + + + align:start position:0% +good too +right and you'll realize the + + align:start position:0% +right and you'll realize the + + + align:start position:0% +right and you'll realize the +fluorescence + + align:start position:0% +fluorescence + + + align:start position:0% +fluorescence +uh is actually very spiky it has like + + align:start position:0% +uh is actually very spiky it has like + + + align:start position:0% +uh is actually very spiky it has like +sharp blue and then a little bit of + + align:start position:0% +sharp blue and then a little bit of + + + align:start position:0% +sharp blue and then a little bit of +green and red very very annoying + + align:start position:0% +green and red very very annoying + + + align:start position:0% +green and red very very annoying +spectrum it's not very nice and smooth + + align:start position:0% +spectrum it's not very nice and smooth + + + align:start position:0% +spectrum it's not very nice and smooth +like the sunlight + + align:start position:0% +like the sunlight + + + align:start position:0% +like the sunlight +um and just i'll just pass it around i + + align:start position:0% +um and just i'll just pass it around i + + + align:start position:0% +um and just i'll just pass it around i +was going to pass around the flash + + align:start position:0% +was going to pass around the flash + + + align:start position:0% +was going to pass around the flash +lighter but + + align:start position:0% +lighter but + + + align:start position:0% +lighter but +um + + align:start position:0% +um + + + align:start position:0% +um +not sure how many people have good hand + + align:start position:0% +not sure how many people have good hand + + + align:start position:0% +not sure how many people have good hand +eye coordination + + align:start position:0% + + + + align:start position:0% + +uh there's also this which is a + + align:start position:0% +uh there's also this which is a + + + align:start position:0% +uh there's also this which is a +diffraction grating and it + + align:start position:0% +diffraction grating and it + + + align:start position:0% +diffraction grating and it +for the purpose of this dispersion it's + + align:start position:0% +for the purpose of this dispersion it's + + + align:start position:0% +for the purpose of this dispersion it's +very similar to a prism so if you look + + align:start position:0% +very similar to a prism so if you look + + + align:start position:0% +very similar to a prism so if you look +through this you will be able to see + + align:start position:0% +through this you will be able to see + + + align:start position:0% +through this you will be able to see +a whole rainbow of colors around any + + align:start position:0% +a whole rainbow of colors around any + + + align:start position:0% +a whole rainbow of colors around any +sort of bright light behind it + + align:start position:0% +sort of bright light behind it + + + align:start position:0% +sort of bright light behind it +so + + align:start position:0% +so + + + align:start position:0% +so +when you're looking at this + + align:start position:0% +when you're looking at this + + + align:start position:0% +when you're looking at this +look at it through a particular angle a + + align:start position:0% +look at it through a particular angle a + + + align:start position:0% +look at it through a particular angle a +particular orientation and then rotate + + align:start position:0% +particular orientation and then rotate + + + align:start position:0% +particular orientation and then rotate +it + + align:start position:0% +it + + + align:start position:0% +it +and as you'll rotate you'll realize that + + align:start position:0% +and as you'll rotate you'll realize that + + + align:start position:0% +and as you'll rotate you'll realize that +it will fall down + + align:start position:0% +it will fall down + + + align:start position:0% +it will fall down +speaking of hand + + align:start position:0% +speaking of hand + + + align:start position:0% +speaking of hand +exactly you have an excuse i was sick + + align:start position:0% +exactly you have an excuse i was sick + + + align:start position:0% +exactly you have an excuse i was sick +this week um + + align:start position:0% +this week um + + + align:start position:0% +this week um +you'll see that the image actually + + align:start position:0% +you'll see that the image actually + + + align:start position:0% +you'll see that the image actually +shifts around so if i'm looking at + + align:start position:0% +shifts around so if i'm looking at + + + align:start position:0% +shifts around so if i'm looking at +daniel i see him then i see a red copy + + align:start position:0% +daniel i see him then i see a red copy + + + align:start position:0% +daniel i see him then i see a red copy +of him and a blue copy of him + + align:start position:0% +of him and a blue copy of him + + + align:start position:0% +of him and a blue copy of him +shifted right i knew there was more than + + align:start position:0% +shifted right i knew there was more than + + + align:start position:0% +shifted right i knew there was more than +one one of you uh and if i wrote it it + + align:start position:0% +one one of you uh and if i wrote it it + + + align:start position:0% +one one of you uh and if i wrote it it +protects and just remember this + + align:start position:0% +protects and just remember this + + + align:start position:0% +protects and just remember this +principle when we come back and talk + + align:start position:0% +principle when we come back and talk + + + align:start position:0% +principle when we come back and talk +when michael starts talking about + + align:start position:0% +when michael starts talking about + + + align:start position:0% +when michael starts talking about +different mechanisms for exploiting + + align:start position:0% +different mechanisms for exploiting + + + align:start position:0% +different mechanisms for exploiting +wavelength again a great class project + + align:start position:0% +wavelength again a great class project + + + align:start position:0% +wavelength again a great class project +idea + + align:start position:0% + + + + align:start position:0% + +sorry right yeah + + align:start position:0% +sorry right yeah + + + align:start position:0% +sorry right yeah +so this this here just shows one of a + + align:start position:0% +so this this here just shows one of a + + + align:start position:0% +so this this here just shows one of a +typical + + align:start position:0% +typical + + + align:start position:0% +typical +spectrogram kind of looks like it's you + + align:start position:0% +spectrogram kind of looks like it's you + + + align:start position:0% +spectrogram kind of looks like it's you +have the wavelength over here and the + + align:start position:0% +have the wavelength over here and the + + + align:start position:0% +have the wavelength over here and the +intensity over here on the y-axis so you + + align:start position:0% +intensity over here on the y-axis so you + + + align:start position:0% +intensity over here on the y-axis so you +can see there's like spikes over here at + + align:start position:0% +can see there's like spikes over here at + + + align:start position:0% +can see there's like spikes over here at + + align:start position:0% + + + align:start position:0% +uh nanometer and then again 600 + + align:start position:0% +uh nanometer and then again 600 + + + align:start position:0% +uh nanometer and then again 600 +something so this is + + align:start position:0% +something so this is + + + align:start position:0% +something so this is +probably a fluorescent light is kind of + + align:start position:0% +probably a fluorescent light is kind of + + + align:start position:0% +probably a fluorescent light is kind of +similar i guess so maybe we can pass + + align:start position:0% +similar i guess so maybe we can pass + + + align:start position:0% +similar i guess so maybe we can pass +around + + align:start position:0% +around + + + align:start position:0% +around +existing + + align:start position:0% + + + + align:start position:0% + +you can look at this sam + + align:start position:0% +you can look at this sam + + + align:start position:0% +you can look at this sam +okay so while one of you is looking so + + align:start position:0% +okay so while one of you is looking so + + + align:start position:0% +okay so while one of you is looking so +uh this is stuff that uh michael is + + align:start position:0% +uh this is stuff that uh michael is + + + align:start position:0% +uh this is stuff that uh michael is +going to get into much more detail later + + align:start position:0% +going to get into much more detail later + + + align:start position:0% +going to get into much more detail later +but i just wanted to mention sort of are + + align:start position:0% +but i just wanted to mention sort of are + + + align:start position:0% +but i just wanted to mention sort of are +you going to talk about + + align:start position:0% + + + + align:start position:0% + +it won't hurt to do it twice so go for + + align:start position:0% +it won't hurt to do it twice so go for + + + align:start position:0% +it won't hurt to do it twice so go for +it okay so i mean it's just something + + align:start position:0% +it okay so i mean it's just something + + + align:start position:0% +it okay so i mean it's just something +which is uh very sort of high level of + + align:start position:0% +which is uh very sort of high level of + + + align:start position:0% +which is uh very sort of high level of +what he's actually going to talk about + + align:start position:0% +what he's actually going to talk about + + + align:start position:0% +what he's actually going to talk about +is the spectroscope is really imaging + + align:start position:0% +is the spectroscope is really imaging + + + align:start position:0% +is the spectroscope is really imaging +the multi the multiple spectrums of a + + align:start position:0% +the multi the multiple spectrums of a + + + align:start position:0% +the multi the multiple spectrums of a +single point + + align:start position:0% +single point + + + align:start position:0% +single point +in space like uh light source over here + + align:start position:0% +in space like uh light source over here + + + align:start position:0% +in space like uh light source over here +if you have a full scene you are not + + align:start position:0% +if you have a full scene you are not + + + align:start position:0% +if you have a full scene you are not +going to get much out of a spectroscope + + align:start position:0% +going to get much out of a spectroscope + + + align:start position:0% +going to get much out of a spectroscope +and what you need to do then is what's + + align:start position:0% +and what you need to do then is what's + + + align:start position:0% +and what you need to do then is what's +called multi-spectral imaging or + + align:start position:0% +called multi-spectral imaging or + + + align:start position:0% +called multi-spectral imaging or +hyperspectral imaging depending on how + + align:start position:0% +hyperspectral imaging depending on how + + + align:start position:0% +hyperspectral imaging depending on how +many spectrums you end up getting + + align:start position:0% +many spectrums you end up getting + + + align:start position:0% +many spectrums you end up getting +and so there are these + + align:start position:0% +and so there are these + + + align:start position:0% +and so there are these +these standard ways of doing that and uh + + align:start position:0% +these standard ways of doing that and uh + + + align:start position:0% +these standard ways of doing that and uh +i just wanted to briefly mention what + + align:start position:0% +i just wanted to briefly mention what + + + align:start position:0% +i just wanted to briefly mention what +those are so usually this kind of + + align:start position:0% +those are so usually this kind of + + + align:start position:0% +those are so usually this kind of +multi-spectrum imaging is very popular + + align:start position:0% +multi-spectrum imaging is very popular + + + align:start position:0% +multi-spectrum imaging is very popular +in remote sensing kind of applications + + align:start position:0% +in remote sensing kind of applications + + + align:start position:0% +in remote sensing kind of applications +where you have a plane or a satellite + + align:start position:0% +where you have a plane or a satellite + + + align:start position:0% +where you have a plane or a satellite +that's flying over a region and you want + + align:start position:0% +that's flying over a region and you want + + + align:start position:0% +that's flying over a region and you want +to get the multispectral or + + align:start position:0% +to get the multispectral or + + + align:start position:0% +to get the multispectral or +hyperspectral image or data set of + + align:start position:0% +hyperspectral image or data set of + + + align:start position:0% +hyperspectral image or data set of +what's what's on the ground underneath + + align:start position:0% +what's what's on the ground underneath + + + align:start position:0% +what's what's on the ground underneath +so what we have here is a lens kind of + + align:start position:0% +so what we have here is a lens kind of + + + align:start position:0% +so what we have here is a lens kind of +thing which is on the plane + + align:start position:0% +thing which is on the plane + + + align:start position:0% +thing which is on the plane +image sensor behind it and the object + + align:start position:0% +image sensor behind it and the object + + + align:start position:0% +image sensor behind it and the object +space which is on the ground + + align:start position:0% +space which is on the ground + + + align:start position:0% +space which is on the ground +and so the most straightforward way of + + align:start position:0% +and so the most straightforward way of + + + align:start position:0% +and so the most straightforward way of +doing this is is what's called uh + + align:start position:0% +doing this is is what's called uh + + + align:start position:0% +doing this is is what's called uh +so so even even this simple imaging + + align:start position:0% +so so even even this simple imaging + + + align:start position:0% +so so even even this simple imaging +where you're not imaging the complete + + align:start position:0% +where you're not imaging the complete + + + align:start position:0% +where you're not imaging the complete +spectrum you can do it in various ways + + align:start position:0% +spectrum you can do it in various ways + + + align:start position:0% +spectrum you can do it in various ways +the first way is where you have a lens + + align:start position:0% +the first way is where you have a lens + + + align:start position:0% +the first way is where you have a lens +which completely completely images the + + align:start position:0% +which completely completely images the + + + align:start position:0% +which completely completely images the +object space onto an image a 2d sensor + + align:start position:0% +object space onto an image a 2d sensor + + + align:start position:0% +object space onto an image a 2d sensor +so this is what just a traditional + + align:start position:0% +so this is what just a traditional + + + align:start position:0% +so this is what just a traditional +camera sort of looks like you capture + + align:start position:0% +camera sort of looks like you capture + + + align:start position:0% +camera sort of looks like you capture +the whole scene in one go + + align:start position:0% +the whole scene in one go + + + align:start position:0% +the whole scene in one go +another way of doing this is what's + + align:start position:0% +another way of doing this is what's + + + align:start position:0% +another way of doing this is what's +called the push broom and a push room + + align:start position:0% +called the push broom and a push room + + + align:start position:0% +called the push broom and a push room +the way i think of it it's you're you're + + align:start position:0% +the way i think of it it's you're you're + + + align:start position:0% +the way i think of it it's you're you're +pushing forward as the + + align:start position:0% +pushing forward as the + + + align:start position:0% +pushing forward as the +platform or the plane is moving in that + + align:start position:0% +platform or the plane is moving in that + + + align:start position:0% +platform or the plane is moving in that +direction so first when the plane is at + + align:start position:0% +direction so first when the plane is at + + + align:start position:0% +direction so first when the plane is at +a particular location you are imaging + + align:start position:0% +a particular location you are imaging + + + align:start position:0% +a particular location you are imaging +this + + align:start position:0% +this + + + align:start position:0% +this +line + + align:start position:0% +line + + + align:start position:0% +line +uh on the scene and then in the next + + align:start position:0% +uh on the scene and then in the next + + + align:start position:0% +uh on the scene and then in the next +instant you will image this slide and + + align:start position:0% +instant you will image this slide and + + + align:start position:0% +instant you will image this slide and +then you will image this line and so on + + align:start position:0% +then you will image this line and so on + + + align:start position:0% +then you will image this line and so on +so as you're moving forward you are + + align:start position:0% +so as you're moving forward you are + + + align:start position:0% +so as you're moving forward you are +imaging one line that's + + align:start position:0% +imaging one line that's + + + align:start position:0% +imaging one line that's +directly under you + + align:start position:0% +directly under you + + + align:start position:0% +directly under you +the other one is called the wisp room in + + align:start position:0% +the other one is called the wisp room in + + + align:start position:0% +the other one is called the wisp room in +which you are + + align:start position:0% +which you are + + + align:start position:0% +which you are +while you're moving forward you're going + + align:start position:0% +while you're moving forward you're going + + + align:start position:0% +while you're moving forward you're going +from left to right and from right to + + align:start position:0% +from left to right and from right to + + + align:start position:0% +from left to right and from right to +left and you're doing this kind of a + + align:start position:0% +left and you're doing this kind of a + + + align:start position:0% +left and you're doing this kind of a +wrist room kind of thing as opposed to a + + align:start position:0% +wrist room kind of thing as opposed to a + + + align:start position:0% +wrist room kind of thing as opposed to a +push group + + align:start position:0% +push group + + + align:start position:0% +push group +and what you do with this uh whisk room + + align:start position:0% +and what you do with this uh whisk room + + + align:start position:0% +and what you do with this uh whisk room +is that when you are imaging this one + + align:start position:0% +is that when you are imaging this one + + + align:start position:0% +is that when you are imaging this one +element you instead of just imaging it + + align:start position:0% +element you instead of just imaging it + + + align:start position:0% +element you instead of just imaging it +onto one sensor you pass the light + + align:start position:0% +onto one sensor you pass the light + + + align:start position:0% +onto one sensor you pass the light +through a prism and you get a whole + + align:start position:0% +through a prism and you get a whole + + + align:start position:0% +through a prism and you get a whole +spectrum similar to a spectroscope + + align:start position:0% +spectrum similar to a spectroscope + + + align:start position:0% +spectrum similar to a spectroscope +and this gives you the complete uh + + align:start position:0% +and this gives you the complete uh + + + align:start position:0% +and this gives you the complete uh +spectral characteristics of this one + + align:start position:0% +spectral characteristics of this one + + + align:start position:0% +spectral characteristics of this one +element or one point on scene and then + + align:start position:0% +element or one point on scene and then + + + align:start position:0% +element or one point on scene and then +in the next instant you are going to + + align:start position:0% +in the next instant you are going to + + + align:start position:0% +in the next instant you are going to +sense the next element right next to it + + align:start position:0% +sense the next element right next to it + + + align:start position:0% +sense the next element right next to it +as your + + align:start position:0% +as your + + + align:start position:0% +as your +whisk room is going from left to right + + align:start position:0% +whisk room is going from left to right + + + align:start position:0% +whisk room is going from left to right +uh and and so on so you're going to + + align:start position:0% +uh and and so on so you're going to + + + align:start position:0% +uh and and so on so you're going to +sense the whole scene + + align:start position:0% +sense the whole scene + + + align:start position:0% +sense the whole scene +the risk the way the push bloom hyper + + align:start position:0% +the risk the way the push bloom hyper + + + align:start position:0% +the risk the way the push bloom hyper +spectral sensor works is that you so so + + align:start position:0% +spectral sensor works is that you so so + + + align:start position:0% +spectral sensor works is that you so so +in this case you need just a 1d sensor + + align:start position:0% +in this case you need just a 1d sensor + + + align:start position:0% +in this case you need just a 1d sensor +in order to capture the complete + + align:start position:0% +in order to capture the complete + + + align:start position:0% +in order to capture the complete +complete data set of the hyperspectral + + align:start position:0% +complete data set of the hyperspectral + + + align:start position:0% +complete data set of the hyperspectral +image of the scene another way of doing + + align:start position:0% +image of the scene another way of doing + + + align:start position:0% +image of the scene another way of doing +it is using the push broom where instead + + align:start position:0% +it is using the push broom where instead + + + align:start position:0% +it is using the push broom where instead +of + + align:start position:0% +of + + + align:start position:0% +of +cap so so you put a prism in front of + + align:start position:0% +cap so so you put a prism in front of + + + align:start position:0% +cap so so you put a prism in front of +each of these elements the image of each + + align:start position:0% +each of these elements the image of each + + + align:start position:0% +each of these elements the image of each +of these elements and then you have a 2d + + align:start position:0% +of these elements and then you have a 2d + + + align:start position:0% +of these elements and then you have a 2d +sensor and this 2d sensor would sense + + align:start position:0% +sensor and this 2d sensor would sense + + + align:start position:0% +sensor and this 2d sensor would sense +along the x-axis is the point in space + + align:start position:0% +along the x-axis is the point in space + + + align:start position:0% +along the x-axis is the point in space +or the point in scene and along the + + align:start position:0% +or the point in scene and along the + + + align:start position:0% +or the point in scene and along the +y-axis is the various spectral bands + + align:start position:0% +y-axis is the various spectral bands + + + align:start position:0% +y-axis is the various spectral bands +that you have for your hyperspectral + + align:start position:0% +that you have for your hyperspectral + + + align:start position:0% +that you have for your hyperspectral +images and then again when in the next + + align:start position:0% +images and then again when in the next + + + align:start position:0% +images and then again when in the next +instant you will sense the next sort of + + align:start position:0% +instant you will sense the next sort of + + + align:start position:0% +instant you will sense the next sort of +uh row in the scene + + align:start position:0% +uh row in the scene + + + align:start position:0% +uh row in the scene +a third way of doing it is basically + + align:start position:0% +a third way of doing it is basically + + + align:start position:0% +a third way of doing it is basically +something that's similar to the + + align:start position:0% +something that's similar to the + + + align:start position:0% +something that's similar to the +a traditional camera is to put a filter + + align:start position:0% +a traditional camera is to put a filter + + + align:start position:0% +a traditional camera is to put a filter +in front of your lens and change the + + align:start position:0% +in front of your lens and change the + + + align:start position:0% +in front of your lens and change the +filter that's in front of your lens sort + + align:start position:0% +filter that's in front of your lens sort + + + align:start position:0% +filter that's in front of your lens sort +of either have that color wheel or have + + align:start position:0% +of either have that color wheel or have + + + align:start position:0% +of either have that color wheel or have +a tunable filter which is whose response + + align:start position:0% +a tunable filter which is whose response + + + align:start position:0% +a tunable filter which is whose response +is changing but at any given instant you + + align:start position:0% +is changing but at any given instant you + + + align:start position:0% +is changing but at any given instant you +have your either sensing green red or + + align:start position:0% +have your either sensing green red or + + + align:start position:0% +have your either sensing green red or +blue + + align:start position:0% +blue + + + align:start position:0% +blue +and then in the next instant you're + + align:start position:0% +and then in the next instant you're + + + align:start position:0% +and then in the next instant you're +sensing the next one it's similar to the + + align:start position:0% +sensing the next one it's similar to the + + + align:start position:0% +sensing the next one it's similar to the +first image we saw in the when i started + + align:start position:0% +first image we saw in the when i started + + + align:start position:0% +first image we saw in the when i started +the talk of capturing multiple images + + align:start position:0% +the talk of capturing multiple images + + + align:start position:0% +the talk of capturing multiple images +with different uh wavelength filters in + + align:start position:0% +with different uh wavelength filters in + + + align:start position:0% +with different uh wavelength filters in +front of the camera + + align:start position:0% +front of the camera + + + align:start position:0% +front of the camera +it's similar to that so you you capture + + align:start position:0% +it's similar to that so you you capture + + + align:start position:0% +it's similar to that so you you capture +the whole scene + + align:start position:0% +the whole scene + + + align:start position:0% +the whole scene +in one instant but only for one + + align:start position:0% +in one instant but only for one + + + align:start position:0% +in one instant but only for one +wavelength + + align:start position:0% +wavelength + + + align:start position:0% +wavelength +so this sort of summarizes what i was + + align:start position:0% +so this sort of summarizes what i was + + + align:start position:0% +so this sort of summarizes what i was +talking about that you have this what's + + align:start position:0% +talking about that you have this what's + + + align:start position:0% +talking about that you have this what's +called the data cube or the object cube + + align:start position:0% +called the data cube or the object cube + + + align:start position:0% +called the data cube or the object cube +which is the x and y are the scene + + align:start position:0% +which is the x and y are the scene + + + align:start position:0% +which is the x and y are the scene +coordinates x y + + align:start position:0% +coordinates x y + + + align:start position:0% +coordinates x y +and lambda is the wavelength where you + + align:start position:0% +and lambda is the wavelength where you + + + align:start position:0% +and lambda is the wavelength where you +it goes from 400 to 700 or slightly uh + + align:start position:0% +it goes from 400 to 700 or slightly uh + + + align:start position:0% +it goes from 400 to 700 or slightly uh +beyond those extremes uh you might also + + align:start position:0% +beyond those extremes uh you might also + + + align:start position:0% +beyond those extremes uh you might also +have near ir and so on but this is what + + align:start position:0% +have near ir and so on but this is what + + + align:start position:0% +have near ir and so on but this is what +you want to get and unfortunate so this + + align:start position:0% +you want to get and unfortunate so this + + + align:start position:0% +you want to get and unfortunate so this +is a 3d sort of object and what you + + align:start position:0% +is a 3d sort of object and what you + + + align:start position:0% +is a 3d sort of object and what you +unfortunately your sensor can be at most + + align:start position:0% +unfortunately your sensor can be at most + + + align:start position:0% +unfortunately your sensor can be at most +a two-dimensional surface + + align:start position:0% +a two-dimensional surface + + + align:start position:0% +a two-dimensional surface +so you want to somehow get this + + align:start position:0% +so you want to somehow get this + + + align:start position:0% +so you want to somehow get this +three-dimensional data set onto a + + align:start position:0% +three-dimensional data set onto a + + + align:start position:0% +three-dimensional data set onto a +two-dimensional sensor + + align:start position:0% +two-dimensional sensor + + + align:start position:0% +two-dimensional sensor +and + + align:start position:0% +and + + + align:start position:0% +and +there are various ways in which you can + + align:start position:0% +there are various ways in which you can + + + align:start position:0% +there are various ways in which you can +do that and + + align:start position:0% +do that and + + + align:start position:0% +do that and +you can the most traditional most + + align:start position:0% +you can the most traditional most + + + align:start position:0% +you can the most traditional most +obvious way of doing it is to have the + + align:start position:0% +obvious way of doing it is to have the + + + align:start position:0% +obvious way of doing it is to have the +third dimension be time so at any one + + align:start position:0% +third dimension be time so at any one + + + align:start position:0% +third dimension be time so at any one +given instant you are either getting a + + align:start position:0% +given instant you are either getting a + + + align:start position:0% +given instant you are either getting a +slice like this or a slice like this or + + align:start position:0% +slice like this or a slice like this or + + + align:start position:0% +slice like this or a slice like this or +a slice like this either along x or + + align:start position:0% +a slice like this either along x or + + + align:start position:0% +a slice like this either along x or +along y or along + + align:start position:0% +along y or along + + + align:start position:0% +along y or along +the wavelength and that in the next + + align:start position:0% +the wavelength and that in the next + + + align:start position:0% +the wavelength and that in the next +instant you get the next slice and so on + + align:start position:0% +instant you get the next slice and so on + + + align:start position:0% +instant you get the next slice and so on +and then you combine all this + + align:start position:0% +and then you combine all this + + + align:start position:0% +and then you combine all this +information together so over a period of + + align:start position:0% +information together so over a period of + + + align:start position:0% +information together so over a period of +time you've built a complete + + align:start position:0% +time you've built a complete + + + align:start position:0% +time you've built a complete +uh object cube or data set so this this + + align:start position:0% +uh object cube or data set so this this + + + align:start position:0% +uh object cube or data set so this this +one is where you're using a filter and + + align:start position:0% +one is where you're using a filter and + + + align:start position:0% +one is where you're using a filter and +this is where you're using a fixed room + + align:start position:0% +this is where you're using a fixed room + + + align:start position:0% +this is where you're using a fixed room +or a push point depending on how you + + align:start position:0% +or a push point depending on how you + + + align:start position:0% +or a push point depending on how you +name them x and y + + align:start position:0% +name them x and y + + + align:start position:0% +name them x and y +so this is sort of the more traditional + + align:start position:0% +so this is sort of the more traditional + + + align:start position:0% +so this is sort of the more traditional +way of doing multi-spectral scanning and + + align:start position:0% +way of doing multi-spectral scanning and + + + align:start position:0% +way of doing multi-spectral scanning and +michael is going to talk about + + align:start position:0% +michael is going to talk about + + + align:start position:0% +michael is going to talk about +even more interesting fancier ways of + + align:start position:0% +even more interesting fancier ways of + + + align:start position:0% +even more interesting fancier ways of +doing it by just taking projections but + + align:start position:0% +doing it by just taking projections but + + + align:start position:0% +doing it by just taking projections but +let me get into that + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +i think ramesh briefly mentioned thermal + + align:start position:0% +i think ramesh briefly mentioned thermal + + + align:start position:0% +i think ramesh briefly mentioned thermal +imaging and uh + + align:start position:0% +imaging and uh + + + align:start position:0% +imaging and uh +can we get the lights off or + + align:start position:0% +can we get the lights off or + + + align:start position:0% +can we get the lights off or +so this is what for those of you who + + align:start position:0% +so this is what for those of you who + + + align:start position:0% +so this is what for those of you who +have never seen a thermal camera we have + + align:start position:0% +have never seen a thermal camera we have + + + align:start position:0% +have never seen a thermal camera we have +one upstairs + + align:start position:0% +one upstairs + + + align:start position:0% +one upstairs +i think we're going to come and play + + align:start position:0% +i think we're going to come and play + + + align:start position:0% +i think we're going to come and play +with but this is what images through our + + align:start position:0% +with but this is what images through our + + + align:start position:0% +with but this is what images through our +typical thermal imager or thermal camera + + align:start position:0% +typical thermal imager or thermal camera + + + align:start position:0% +typical thermal imager or thermal camera +look like uh this is sensing in usually + + align:start position:0% +look like uh this is sensing in usually + + + align:start position:0% +look like uh this is sensing in usually +in the wavelengths in the range of one + + align:start position:0% +in the wavelengths in the range of one + + + align:start position:0% +in the wavelengths in the range of one +micron to about 10 microns or 15 microns + + align:start position:0% +micron to about 10 microns or 15 microns + + + align:start position:0% +micron to about 10 microns or 15 microns +in that range that's the range in which + + align:start position:0% +in that range that's the range in which + + + align:start position:0% +in that range that's the range in which +humans show up as warm bodies usually so + + align:start position:0% +humans show up as warm bodies usually so + + + align:start position:0% +humans show up as warm bodies usually so +six to eight micron kind of range but + + align:start position:0% +six to eight micron kind of range but + + + align:start position:0% +six to eight micron kind of range but +you can also have uh + + align:start position:0% +you can also have uh + + + align:start position:0% +you can also have uh +like like actually hot bodies warm + + align:start position:0% +like like actually hot bodies warm + + + align:start position:0% +like like actually hot bodies warm +bodies uh show up + + align:start position:0% +bodies uh show up + + + align:start position:0% +bodies uh show up +uh like uh heat-seeking missiles and so + + align:start position:0% +uh like uh heat-seeking missiles and so + + + align:start position:0% +uh like uh heat-seeking missiles and so +on but this is + + align:start position:0% +on but this is + + + align:start position:0% +on but this is +something that's explored a lot in in + + align:start position:0% +something that's explored a lot in in + + + align:start position:0% +something that's explored a lot in in +the defense industry these use of + + align:start position:0% +the defense industry these use of + + + align:start position:0% +the defense industry these use of +high resolution very fast thermal + + align:start position:0% +high resolution very fast thermal + + + align:start position:0% +high resolution very fast thermal +cameras but it's something that's more + + align:start position:0% +cameras but it's something that's more + + + align:start position:0% +cameras but it's something that's more +very + + align:start position:0% +very + + + align:start position:0% +very +rapidly coming into the + + align:start position:0% +rapidly coming into the + + + align:start position:0% +rapidly coming into the +other applications also there was + + align:start position:0% +other applications also there was + + + align:start position:0% +other applications also there was +recently an article in time i think in + + align:start position:0% +recently an article in time i think in + + + align:start position:0% +recently an article in time i think in +where they were looking at the various + + align:start position:0% +where they were looking at the various + + + align:start position:0% +where they were looking at the various +the thermal profile of a house from + + align:start position:0% +the thermal profile of a house from + + + align:start position:0% +the thermal profile of a house from +outside to find out where it's leaking + + align:start position:0% +outside to find out where it's leaking + + + align:start position:0% +outside to find out where it's leaking +and where the heat is escaping and then + + align:start position:0% +and where the heat is escaping and then + + + align:start position:0% +and where the heat is escaping and then +they're using these kind of thermal + + align:start position:0% +they're using these kind of thermal + + + align:start position:0% +they're using these kind of thermal +cameras to actually test for whether + + align:start position:0% +cameras to actually test for whether + + + align:start position:0% +cameras to actually test for whether +pipes are leaking and your + + align:start position:0% +pipes are leaking and your + + + align:start position:0% +pipes are leaking and your +hvac is working properly or not and + + align:start position:0% +hvac is working properly or not and + + + align:start position:0% +hvac is working properly or not and +things like that so it's finding lots of + + align:start position:0% +things like that so it's finding lots of + + + align:start position:0% +things like that so it's finding lots of +applications and areas other than just + + align:start position:0% +applications and areas other than just + + + align:start position:0% +applications and areas other than just +traditional defense and so on and that's + + align:start position:0% +traditional defense and so on and that's + + + align:start position:0% +traditional defense and so on and that's +one of the reason why + + align:start position:0% +one of the reason why + + + align:start position:0% +one of the reason why +slowly the price of these cameras which + + align:start position:0% +slowly the price of these cameras which + + + align:start position:0% +slowly the price of these cameras which +used to be about twenty thousand dollars + + align:start position:0% +used to be about twenty thousand dollars + + + align:start position:0% +used to be about twenty thousand dollars +each is hopefully coming down + + align:start position:0% + + + + align:start position:0% + +this is sort of another image of uh just + + align:start position:0% +this is sort of another image of uh just + + + align:start position:0% +this is sort of another image of uh just +thermal images which i thought was + + align:start position:0% +thermal images which i thought was + + + align:start position:0% +thermal images which i thought was +interesting the first one is what's + + align:start position:0% +interesting the first one is what's + + + align:start position:0% +interesting the first one is what's +showing is that you when you think of + + align:start position:0% +showing is that you when you think of + + + align:start position:0% +showing is that you when you think of +thermal light it's actually quite + + align:start position:0% +thermal light it's actually quite + + + align:start position:0% +thermal light it's actually quite +different from when you when you're + + align:start position:0% +different from when you when you're + + + align:start position:0% +different from when you when you're +looking at visible light + + align:start position:0% +looking at visible light + + + align:start position:0% +looking at visible light +and + + align:start position:0% +and + + + align:start position:0% +and +one example i think uh we ramesh already + + align:start position:0% +one example i think uh we ramesh already + + + align:start position:0% +one example i think uh we ramesh already +mentioned is that of glass that class + + align:start position:0% +mentioned is that of glass that class + + + align:start position:0% +mentioned is that of glass that class +opex appears opaque in thermal ir so you + + align:start position:0% +opex appears opaque in thermal ir so you + + + align:start position:0% +opex appears opaque in thermal ir so you +can't look through class + + align:start position:0% +can't look through class + + + align:start position:0% +can't look through class +and there are other objects which may + + align:start position:0% +and there are other objects which may + + + align:start position:0% +and there are other objects which may +appear completely + + align:start position:0% +appear completely + + + align:start position:0% +appear completely +excuse me transparent in thermal ir but + + align:start position:0% +excuse me transparent in thermal ir but + + + align:start position:0% +excuse me transparent in thermal ir but +are opaque and visible light this is one + + align:start position:0% +are opaque and visible light this is one + + + align:start position:0% +are opaque and visible light this is one +example which is sort of interesting you + + align:start position:0% +example which is sort of interesting you + + + align:start position:0% +example which is sort of interesting you +have this fridge which is brushed metal + + align:start position:0% +have this fridge which is brushed metal + + + align:start position:0% +have this fridge which is brushed metal +and so in the reflection you see this + + align:start position:0% +and so in the reflection you see this + + + align:start position:0% +and so in the reflection you see this +sort of very diffuse reflection you + + align:start position:0% +sort of very diffuse reflection you + + + align:start position:0% +sort of very diffuse reflection you +can't really see what's on the other + + align:start position:0% +can't really see what's on the other + + + align:start position:0% +can't really see what's on the other +side but if you just use thermal ir you + + align:start position:0% +side but if you just use thermal ir you + + + align:start position:0% +side but if you just use thermal ir you +can very clearly see there is this rice + + align:start position:0% +can very clearly see there is this rice + + + align:start position:0% +can very clearly see there is this rice +oven sort of on the other side that's + + align:start position:0% +oven sort of on the other side that's + + + align:start position:0% +oven sort of on the other side that's +really really hot and the reflection is + + align:start position:0% +really really hot and the reflection is + + + align:start position:0% +really really hot and the reflection is +nice and sharp because the wavelength + + align:start position:0% +nice and sharp because the wavelength + + + align:start position:0% +nice and sharp because the wavelength +that you're using is now not 700 + + align:start position:0% +that you're using is now not 700 + + + align:start position:0% +that you're using is now not 700 +nanometers but it's something much + + align:start position:0% +nanometers but it's something much + + + align:start position:0% +nanometers but it's something much +larger and the surface is actually very + + align:start position:0% +larger and the surface is actually very + + + align:start position:0% +larger and the surface is actually very +smooth when you look at that wavelength + + align:start position:0% +smooth when you look at that wavelength + + + align:start position:0% +smooth when you look at that wavelength +but when you're looking at it in the + + align:start position:0% +but when you're looking at it in the + + + align:start position:0% +but when you're looking at it in the +visible spectrum it appears + + align:start position:0% +visible spectrum it appears + + + align:start position:0% +visible spectrum it appears +very diffuse and you can hardly see what + + align:start position:0% +very diffuse and you can hardly see what + + + align:start position:0% +very diffuse and you can hardly see what +the reflection is behind like a mirror + + align:start position:0% +the reflection is behind like a mirror + + + align:start position:0% +the reflection is behind like a mirror +it behaves like a mirror in the thermal + + align:start position:0% +it behaves like a mirror in the thermal + + + align:start position:0% +it behaves like a mirror in the thermal +sort of thermal ir range because of the + + align:start position:0% +sort of thermal ir range because of the + + + align:start position:0% +sort of thermal ir range because of the +difference in wavelength + + align:start position:0% +difference in wavelength + + + align:start position:0% +difference in wavelength +so this is sort of an interesting thing + + align:start position:0% +so this is sort of an interesting thing + + + align:start position:0% +so this is sort of an interesting thing +to think about of applications where + + align:start position:0% +to think about of applications where + + + align:start position:0% +to think about of applications where +you can imagine you had one of these + + align:start position:0% +you can imagine you had one of these + + + align:start position:0% +you can imagine you had one of these +thermal imaging cameras on each cell + + align:start position:0% +thermal imaging cameras on each cell + + + align:start position:0% +thermal imaging cameras on each cell +phone right next to your normal camera + + align:start position:0% +phone right next to your normal camera + + + align:start position:0% +phone right next to your normal camera +what could you do with it or let's say + + align:start position:0% +what could you do with it or let's say + + + align:start position:0% +what could you do with it or let's say +you had it right next to your webcam on + + align:start position:0% +you had it right next to your webcam on + + + align:start position:0% +you had it right next to your webcam on +your cam on your laptop and you do use + + align:start position:0% +your cam on your laptop and you do use + + + align:start position:0% +your cam on your laptop and you do use +do something interesting with it + + align:start position:0% +do something interesting with it + + + align:start position:0% +do something interesting with it +another one is this paper from + + align:start position:0% +another one is this paper from + + + align:start position:0% +another one is this paper from +university of colorado no universe + + align:start position:0% +university of colorado no universe + + + align:start position:0% +university of colorado no universe +houston houston right where they use + + align:start position:0% +houston houston right where they use + + + align:start position:0% +houston houston right where they use +thermal cameras to detect uh for light + + align:start position:0% +thermal cameras to detect uh for light + + + align:start position:0% +thermal cameras to detect uh for light +detection and they have this paper in + + align:start position:0% +detection and they have this paper in + + + align:start position:0% +detection and they have this paper in +nature where they + + align:start position:0% +nature where they + + + align:start position:0% +nature where they +uh analyze the + + align:start position:0% +uh analyze the + + + align:start position:0% +uh analyze the +the region around the eyes and how that + + align:start position:0% +the region around the eyes and how that + + + align:start position:0% +the region around the eyes and how that +changes when someone is lying in the + + align:start position:0% +changes when someone is lying in the + + + align:start position:0% +changes when someone is lying in the +thermal ir range and they claim that + + align:start position:0% +thermal ir range and they claim that + + + align:start position:0% +thermal ir range and they claim that +they're getting as good performance as a + + align:start position:0% +they're getting as good performance as a + + + align:start position:0% +they're getting as good performance as a +traditional lie detector + + align:start position:0% +traditional lie detector + + + align:start position:0% +traditional lie detector +it's not easy to reproduce unfortunately + + align:start position:0% +it's not easy to reproduce unfortunately + + + align:start position:0% +it's not easy to reproduce unfortunately +the results + + align:start position:0% +the results + + + align:start position:0% +the results +but + + align:start position:0% +but + + + align:start position:0% +but +the it looks pretty interesting + + align:start position:0% +the it looks pretty interesting + + + align:start position:0% +the it looks pretty interesting +and the whole concept is that + + align:start position:0% +and the whole concept is that + + + align:start position:0% +and the whole concept is that +the blood veins pump more + + align:start position:0% +the blood veins pump more + + + align:start position:0% +the blood veins pump more +blood + + align:start position:0% +blood + + + align:start position:0% +blood +as your emotions change + + align:start position:0% +as your emotions change + + + align:start position:0% +as your emotions change +so as long as you can detect + + align:start position:0% +so as long as you can detect + + + align:start position:0% +so as long as you can detect +subcutaneous changes + + align:start position:0% +subcutaneous changes + + + align:start position:0% +subcutaneous changes +in blood flow + + align:start position:0% +in blood flow + + + align:start position:0% +in blood flow +you can + + align:start position:0% +you can + + + align:start position:0% +you can +detect + + align:start position:0% +detect + + + align:start position:0% +detect +the correlated emotions + + align:start position:0% +the correlated emotions + + + align:start position:0% +the correlated emotions +i think the difference is really very + + align:start position:0% +i think the difference is really very + + + align:start position:0% +i think the difference is really very +very subtle and it's greatly magnified + + align:start position:0% +very subtle and it's greatly magnified + + + align:start position:0% +very subtle and it's greatly magnified +in this image that they show so when we + + align:start position:0% +in this image that they show so when we + + + align:start position:0% +in this image that they show so when we +try to do this we couldn't spot any + + align:start position:0% +try to do this we couldn't spot any + + + align:start position:0% +try to do this we couldn't spot any +difference number one of course nobody + + align:start position:0% +difference number one of course nobody + + + align:start position:0% +difference number one of course nobody +lies in our group either + + align:start position:0% + + + + align:start position:0% + +so one other thing + + align:start position:0% +so one other thing + + + align:start position:0% +so one other thing +when we were doing this last last year + + align:start position:0% +when we were doing this last last year + + + align:start position:0% +when we were doing this last last year +someone talked about near infrared + + align:start position:0% +someone talked about near infrared + + + align:start position:0% +someone talked about near infrared +photography and this is more from a + + align:start position:0% +photography and this is more from a + + + align:start position:0% +photography and this is more from a +photography point of view that actually + + align:start position:0% +photography point of view that actually + + + align:start position:0% +photography point of view that actually +it turns out most of the ccd sensors are + + align:start position:0% +it turns out most of the ccd sensors are + + + align:start position:0% +it turns out most of the ccd sensors are +uh + + align:start position:0% +uh + + + align:start position:0% +uh +they're actually sensitive to near ir or + + align:start position:0% +they're actually sensitive to near ir or + + + align:start position:0% +they're actually sensitive to near ir or +infrared that's just just after 700 + + align:start position:0% +infrared that's just just after 700 + + + align:start position:0% +infrared that's just just after 700 +nanometers from 700 to about one micron + + align:start position:0% +nanometers from 700 to about one micron + + + align:start position:0% +nanometers from 700 to about one micron +and they they are sensitive to that but + + align:start position:0% +and they they are sensitive to that but + + + align:start position:0% +and they they are sensitive to that but +in fact most manufacturers put an ir + + align:start position:0% +in fact most manufacturers put an ir + + + align:start position:0% +in fact most manufacturers put an ir +block filter on top of the sensor that + + align:start position:0% +block filter on top of the sensor that + + + align:start position:0% +block filter on top of the sensor that +blocks anything that's greater than 700 + + align:start position:0% +blocks anything that's greater than 700 + + + align:start position:0% +blocks anything that's greater than 700 +nanometers so what you can do is remove + + align:start position:0% +nanometers so what you can do is remove + + + align:start position:0% +nanometers so what you can do is remove +that ir block filter and you can then + + align:start position:0% +that ir block filter and you can then + + + align:start position:0% +that ir block filter and you can then +capture nice pretty images like this + + align:start position:0% +capture nice pretty images like this + + + align:start position:0% +capture nice pretty images like this +this of course is all they're all fake + + align:start position:0% +this of course is all they're all fake + + + align:start position:0% +this of course is all they're all fake +images because you don't really get any + + align:start position:0% +images because you don't really get any + + + align:start position:0% +images because you don't really get any +sense of color once you go beyond 700 + + align:start position:0% +sense of color once you go beyond 700 + + + align:start position:0% +sense of color once you go beyond 700 +nanometers so people usually just + + align:start position:0% +nanometers so people usually just + + + align:start position:0% +nanometers so people usually just +fill in fake colors based on the + + align:start position:0% +fill in fake colors based on the + + + align:start position:0% +fill in fake colors based on the +based on an original visual image or + + align:start position:0% +based on an original visual image or + + + align:start position:0% +based on an original visual image or +something like that but another + + align:start position:0% +something like that but another + + + align:start position:0% +something like that but another +place where you can get these colors is + + align:start position:0% +place where you can get these colors is + + + align:start position:0% +place where you can get these colors is +if you use ir film there is kodak has + + align:start position:0% +if you use ir film there is kodak has + + + align:start position:0% +if you use ir film there is kodak has +this color ir film which reacts + + align:start position:0% +this color ir film which reacts + + + align:start position:0% +this color ir film which reacts +differently to different wavelengths + + align:start position:0% +differently to different wavelengths + + + align:start position:0% +differently to different wavelengths +beyond the 700 nanometers and that gives + + align:start position:0% +beyond the 700 nanometers and that gives + + + align:start position:0% +beyond the 700 nanometers and that gives +you these interesting sort of colors + + align:start position:0% +you these interesting sort of colors + + + align:start position:0% +you these interesting sort of colors +so these are not nighttime photos these + + align:start position:0% +so these are not nighttime photos these + + + align:start position:0% +so these are not nighttime photos these +are just daytime photos + + align:start position:0% +are just daytime photos + + + align:start position:0% +are just daytime photos +with some pseudo color superimposed + + align:start position:0% +with some pseudo color superimposed + + + align:start position:0% +with some pseudo color superimposed +so the one interesting sort of thing is + + align:start position:0% +so the one interesting sort of thing is + + + align:start position:0% +so the one interesting sort of thing is +that + + align:start position:0% +that + + + align:start position:0% +that +i think sky becomes really really black + + align:start position:0% +i think sky becomes really really black + + + align:start position:0% +i think sky becomes really really black +and opaque so that's because if you + + align:start position:0% +and opaque so that's because if you + + + align:start position:0% +and opaque so that's because if you +remember + + align:start position:0% +remember + + + align:start position:0% +remember +sky does not allow ir to come through as + + align:start position:0% +sky does not allow ir to come through as + + + align:start position:0% +sky does not allow ir to come through as +much but also any vegetation becomes + + align:start position:0% +much but also any vegetation becomes + + + align:start position:0% +much but also any vegetation becomes +really bright and white and that's sort + + align:start position:0% +really bright and white and that's sort + + + align:start position:0% +really bright and white and that's sort +of why you have the snow like effect on + + align:start position:0% +of why you have the snow like effect on + + + align:start position:0% +of why you have the snow like effect on +any on trees and things like that but + + align:start position:0% +any on trees and things like that but + + + align:start position:0% +any on trees and things like that but +your uh barks of the tree and the food + + align:start position:0% +your uh barks of the tree and the food + + + align:start position:0% +your uh barks of the tree and the food +actually does not + + align:start position:0% +actually does not + + + align:start position:0% +actually does not +it actually absorbs more light it does + + align:start position:0% +it actually absorbs more light it does + + + align:start position:0% +it actually absorbs more light it does +not reflect so much back + + align:start position:0% +not reflect so much back + + + align:start position:0% +not reflect so much back +so it's just interesting uh + + align:start position:0% +so it's just interesting uh + + + align:start position:0% +so it's just interesting uh +sort of things + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% +and + + + align:start position:0% +and +i mentioned this briefly earlier one of + + align:start position:0% +i mentioned this briefly earlier one of + + + align:start position:0% +i mentioned this briefly earlier one of +the biggest applications of this sort of + + align:start position:0% +the biggest applications of this sort of + + + align:start position:0% +the biggest applications of this sort of +thing has traditionally been in remote + + align:start position:0% +thing has traditionally been in remote + + + align:start position:0% +thing has traditionally been in remote +sensing also and + + align:start position:0% +sensing also and + + + align:start position:0% +sensing also and +uh by capturing multispectral or + + align:start position:0% +uh by capturing multispectral or + + + align:start position:0% +uh by capturing multispectral or +hyperspectral images of a scene of + + align:start position:0% +hyperspectral images of a scene of + + + align:start position:0% +hyperspectral images of a scene of +especially + + align:start position:0% +especially + + + align:start position:0% +especially +vegetation you can actually classify + + align:start position:0% +vegetation you can actually classify + + + align:start position:0% +vegetation you can actually classify +what crop is what and what + + align:start position:0% +what crop is what and what + + + align:start position:0% +what crop is what and what +what kind what's the road and where you + + align:start position:0% +what kind what's the road and where you + + + align:start position:0% +what kind what's the road and where you +have uh plantations and what kind of + + align:start position:0% +have uh plantations and what kind of + + + align:start position:0% +have uh plantations and what kind of +plantations like over here they're able + + align:start position:0% +plantations like over here they're able + + + align:start position:0% +plantations like over here they're able +to distinguish between all these + + align:start position:0% +to distinguish between all these + + + align:start position:0% +to distinguish between all these +different kind of crops + + align:start position:0% +different kind of crops + + + align:start position:0% +different kind of crops +and this is something you can do if you + + align:start position:0% +and this is something you can do if you + + + align:start position:0% +and this is something you can do if you +have enough resolution in the multiple + + align:start position:0% +have enough resolution in the multiple + + + align:start position:0% +have enough resolution in the multiple +spectrums that you're getting just + + align:start position:0% +spectrums that you're getting just + + + align:start position:0% +spectrums that you're getting just +because each + + align:start position:0% +because each + + + align:start position:0% +because each +sort of vegetation or tree actually has + + align:start position:0% +sort of vegetation or tree actually has + + + align:start position:0% +sort of vegetation or tree actually has +a very different reflectance profile + + align:start position:0% +a very different reflectance profile + + + align:start position:0% +a very different reflectance profile +when you look at + + align:start position:0% +when you look at + + + align:start position:0% +when you look at +look at it even though it they both + + align:start position:0% +look at it even though it they both + + + align:start position:0% +look at it even though it they both +appear green to the human eye if you + + align:start position:0% +appear green to the human eye if you + + + align:start position:0% +appear green to the human eye if you +look at the actual spectrum response + + align:start position:0% +look at the actual spectrum response + + + align:start position:0% +look at the actual spectrum response +it's quite different and you can + + align:start position:0% +it's quite different and you can + + + align:start position:0% +it's quite different and you can +distinguish between different + + align:start position:0% +distinguish between different + + + align:start position:0% +distinguish between different +materials based on that + + align:start position:0% +materials based on that + + + align:start position:0% +materials based on that +this is not based on ir though this is + + align:start position:0% +this is not based on ir though this is + + + align:start position:0% +this is not based on ir though this is +just this is visible this is i think it + + align:start position:0% +just this is visible this is i think it + + + align:start position:0% +just this is visible this is i think it +usually goes into near ir at least most + + align:start position:0% +usually goes into near ir at least most + + + align:start position:0% +usually goes into near ir at least most +of the remote sensing stuff because i + + align:start position:0% +of the remote sensing stuff because i + + + align:start position:0% +of the remote sensing stuff because i +think most of the interesting stuff + + align:start position:0% +think most of the interesting stuff + + + align:start position:0% +think most of the interesting stuff +of this kind of distinguishing thing + + align:start position:0% +of this kind of distinguishing thing + + + align:start position:0% +of this kind of distinguishing thing +actually happens in india + + align:start position:0% +actually happens in india + + + align:start position:0% +actually happens in india +but they do include visible light they + + align:start position:0% +but they do include visible light they + + + align:start position:0% +but they do include visible light they +might have a band of 5 nanometers or 10 + + align:start position:0% +might have a band of 5 nanometers or 10 + + + align:start position:0% +might have a band of 5 nanometers or 10 +nanometers + + align:start position:0% +nanometers + + + align:start position:0% +nanometers +and + + align:start position:0% +and + + + align:start position:0% +and +capture 20 30 channels and then from + + align:start position:0% +capture 20 30 channels and then from + + + align:start position:0% +capture 20 30 channels and then from +that through this high dimensional + + align:start position:0% +that through this high dimensional + + + align:start position:0% +that through this high dimensional +signal they can certification + + align:start position:0% +signal they can certification + + + align:start position:0% +signal they can certification +i'm not exactly sure do you know michael + + align:start position:0% +i'm not exactly sure do you know michael + + + align:start position:0% +i'm not exactly sure do you know michael +what what trains they usually use for + + align:start position:0% +what what trains they usually use for + + + align:start position:0% +what what trains they usually use for +this kind of + + align:start position:0% +this kind of + + + align:start position:0% +this kind of +media usually i mean i don't know + + align:start position:0% +media usually i mean i don't know + + + align:start position:0% +media usually i mean i don't know +usually but they don't it is definitely + + align:start position:0% +usually but they don't it is definitely + + + align:start position:0% +usually but they don't it is definitely +common to go into the ir and sometimes + + align:start position:0% +common to go into the ir and sometimes + + + align:start position:0% +common to go into the ir and sometimes +even in the evening + + align:start position:0% +even in the evening + + + align:start position:0% +even in the evening +right + + align:start position:0% + + + + align:start position:0% + +so talking about uv you can also do + + align:start position:0% +so talking about uv you can also do + + + align:start position:0% +so talking about uv you can also do +interesting sort of photography in the + + align:start position:0% +interesting sort of photography in the + + + align:start position:0% +interesting sort of photography in the +uv range and uh this is this is an + + align:start position:0% +uv range and uh this is this is an + + + align:start position:0% +uv range and uh this is this is an +amazing website if you get a chance you + + align:start position:0% +amazing website if you get a chance you + + + align:start position:0% +amazing website if you get a chance you +should definitely visit they have this + + align:start position:0% +should definitely visit they have this + + + align:start position:0% +should definitely visit they have this +guy has like pictures of all kinds of + + align:start position:0% +guy has like pictures of all kinds of + + + align:start position:0% +guy has like pictures of all kinds of +flowers and both invisible uh spectrum + + align:start position:0% +flowers and both invisible uh spectrum + + + align:start position:0% +flowers and both invisible uh spectrum +and then in uv and it turns out that + + align:start position:0% +and then in uv and it turns out that + + + align:start position:0% +and then in uv and it turns out that +the flowers look just amazingly + + align:start position:0% +the flowers look just amazingly + + + align:start position:0% +the flowers look just amazingly +different when you look at them in uv + + align:start position:0% +different when you look at them in uv + + + align:start position:0% +different when you look at them in uv +and you have these almost these sort of + + align:start position:0% +and you have these almost these sort of + + + align:start position:0% +and you have these almost these sort of +landing strips that + + align:start position:0% +landing strips that + + + align:start position:0% +landing strips that +invite the + + align:start position:0% +invite the + + + align:start position:0% +invite the +bees to come and sit they give + + align:start position:0% +bees to come and sit they give + + + align:start position:0% +bees to come and sit they give +directions don't sit here sit over here + + align:start position:0% +directions don't sit here sit over here + + + align:start position:0% +directions don't sit here sit over here +kind of almost + + align:start position:0% +kind of almost + + + align:start position:0% +kind of almost +whereas if you look at it in the visible + + align:start position:0% +whereas if you look at it in the visible + + + align:start position:0% +whereas if you look at it in the visible +light it's all yellow or it's all red + + align:start position:0% +light it's all yellow or it's all red + + + align:start position:0% +light it's all yellow or it's all red +and there's hardly any difference + + align:start position:0% +and there's hardly any difference + + + align:start position:0% +and there's hardly any difference +between + + align:start position:0% +between + + + align:start position:0% +between +you you don't see that which last one is + + align:start position:0% +you you don't see that which last one is + + + align:start position:0% +you you don't see that which last one is +especially striking + + align:start position:0% +especially striking + + + align:start position:0% +especially striking +yeah yeah there's like portions which i + + align:start position:0% +yeah yeah there's like portions which i + + + align:start position:0% +yeah yeah there's like portions which i +think + + align:start position:0% +think + + + align:start position:0% +think +well again this is all fake color there + + align:start position:0% +well again this is all fake color there + + + align:start position:0% +well again this is all fake color there +really is no color in this uv + + align:start position:0% +really is no color in this uv + + + align:start position:0% +really is no color in this uv +intensity + + align:start position:0% +intensity + + + align:start position:0% +intensity +but one sort of thing i want to point + + align:start position:0% +but one sort of thing i want to point + + + align:start position:0% +but one sort of thing i want to point +out here is that you cannot do this sort + + align:start position:0% +out here is that you cannot do this sort + + + align:start position:0% +out here is that you cannot do this sort +of photography with most traditional + + align:start position:0% +of photography with most traditional + + + align:start position:0% +of photography with most traditional +cameras because glass is actually + + align:start position:0% +cameras because glass is actually + + + align:start position:0% +cameras because glass is actually +it absorbs + + align:start position:0% +it absorbs + + + align:start position:0% +it absorbs +uv so they use these special + + align:start position:0% +uv so they use these special + + + align:start position:0% +uv so they use these special +rare earth quartz lenses which are super + + align:start position:0% +rare earth quartz lenses which are super + + + align:start position:0% +rare earth quartz lenses which are super +super expensive in order to do these + + align:start position:0% +super expensive in order to do these + + + align:start position:0% +super expensive in order to do these +kind of + + align:start position:0% +kind of + + + align:start position:0% +kind of +this kind of photography + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +but you could use for example + + align:start position:0% +but you could use for example + + + align:start position:0% +but you could use for example +uh what uh + + align:start position:0% +uh what uh + + + align:start position:0% +uh what uh +what professor oliver was talking about + + align:start position:0% +what professor oliver was talking about + + + align:start position:0% +what professor oliver was talking about +instead of using a lens you could use + + align:start position:0% +instead of using a lens you could use + + + align:start position:0% +instead of using a lens you could use +a um a fennel zone plate which is like a + + align:start position:0% +a um a fennel zone plate which is like a + + + align:start position:0% +a um a fennel zone plate which is like a +pinhole camera + + align:start position:0% +pinhole camera + + + align:start position:0% +pinhole camera +except glorified it has more interesting + + align:start position:0% +except glorified it has more interesting + + + align:start position:0% +except glorified it has more interesting +pattern + + align:start position:0% +pattern + + + align:start position:0% +pattern +and then on the sensor you could put a + + align:start position:0% +and then on the sensor you could put a + + + align:start position:0% +and then on the sensor you could put a +layer of fluorescent material + + align:start position:0% +layer of fluorescent material + + + align:start position:0% +layer of fluorescent material +so that the uv will + + align:start position:0% +so that the uv will + + + align:start position:0% +so that the uv will +stimulate the fluorescent and then we + + align:start position:0% +stimulate the fluorescent and then we + + + align:start position:0% +stimulate the fluorescent and then we +can image + + align:start position:0% +can image + + + align:start position:0% +can image +through that so you can you can kind of + + align:start position:0% + + + + align:start position:0% + +go around some of the limitations in a + + align:start position:0% +go around some of the limitations in a + + + align:start position:0% +go around some of the limitations in a +traditional camera to do + + align:start position:0% +traditional camera to do + + + align:start position:0% +traditional camera to do +that's what they do in a way for a lot + + align:start position:0% +that's what they do in a way for a lot + + + align:start position:0% +that's what they do in a way for a lot +of uh medical imaging + + align:start position:0% +of uh medical imaging + + + align:start position:0% +of uh medical imaging +by using forces + + align:start position:0% +by using forces + + + align:start position:0% +by using forces +also a lot of these these images that + + align:start position:0% +also a lot of these these images that + + + align:start position:0% +also a lot of these these images that +you find that they all use film + + align:start position:0% +you find that they all use film + + + align:start position:0% +you find that they all use film +photography they rarely use digital + + align:start position:0% +photography they rarely use digital + + + align:start position:0% +photography they rarely use digital +cameras for these kind of things + + align:start position:0% +cameras for these kind of things + + + align:start position:0% +cameras for these kind of things +i mean even for near ir i think + + align:start position:0% +i mean even for near ir i think + + + align:start position:0% +i mean even for near ir i think +this pseudo color by the way is you know + + align:start position:0% +this pseudo color by the way is you know + + + align:start position:0% +this pseudo color by the way is you know +just one of the major craze and that has + + align:start position:0% +just one of the major craze and that has + + + align:start position:0% +just one of the major craze and that has +been around for several years + + align:start position:0% +been around for several years + + + align:start position:0% +been around for several years +of + + align:start position:0% +of + + + align:start position:0% +of +so remember the uv in the uv spectrum + + align:start position:0% +so remember the uv in the uv spectrum + + + align:start position:0% +so remember the uv in the uv spectrum +these images are going to look just + + align:start position:0% +these images are going to look just + + + align:start position:0% +these images are going to look just +monochrome it's black and white but + + align:start position:0% +monochrome it's black and white but + + + align:start position:0% +monochrome it's black and white but +artists like to + + align:start position:0% +artists like to + + + align:start position:0% +artists like to +start assigning some colors + + align:start position:0% +start assigning some colors + + + align:start position:0% +start assigning some colors +to different intensity levels + + align:start position:0% +to different intensity levels + + + align:start position:0% +to different intensity levels +to see more interesting and + + align:start position:0% +to see more interesting and + + + align:start position:0% +to see more interesting and +for for nasa and for + + align:start position:0% +for for nasa and for + + + align:start position:0% +for for nasa and for +for astronomy + + align:start position:0% +for astronomy + + + align:start position:0% +for astronomy +they realized it some time over 20 years + + align:start position:0% +they realized it some time over 20 years + + + align:start position:0% +they realized it some time over 20 years +ago that instead of putting those + + align:start position:0% +ago that instead of putting those + + + align:start position:0% +ago that instead of putting those +pictures of the nebulas and + + align:start position:0% +pictures of the nebulas and + + + align:start position:0% +pictures of the nebulas and +all that sort of just putting them in + + align:start position:0% +all that sort of just putting them in + + + align:start position:0% +all that sort of just putting them in +this really boring monochrome colors + + align:start position:0% +this really boring monochrome colors + + + align:start position:0% +this really boring monochrome colors +let's start coloring them + + align:start position:0% +let's start coloring them + + + align:start position:0% +let's start coloring them +you know beautiful reddish hues and + + align:start position:0% +you know beautiful reddish hues and + + + align:start position:0% +you know beautiful reddish hues and +greenish lavas and so on + + align:start position:0% +greenish lavas and so on + + + align:start position:0% +greenish lavas and so on +the real thing doesn't look like that at + + align:start position:0% +the real thing doesn't look like that at + + + align:start position:0% +the real thing doesn't look like that at +all + + align:start position:0% +all + + + align:start position:0% +all +but + + align:start position:0% +but + + + align:start position:0% +but +it allows ordinary people to start + + align:start position:0% +it allows ordinary people to start + + + align:start position:0% +it allows ordinary people to start +appreciating astronomy + + align:start position:0% +appreciating astronomy + + + align:start position:0% +appreciating astronomy +yeah it's like the + + align:start position:0% +yeah it's like the + + + align:start position:0% +yeah it's like the +the wallpaper on that comes with osx has + + align:start position:0% +the wallpaper on that comes with osx has + + + align:start position:0% +the wallpaper on that comes with osx has +now + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +now switching gears a little bit this + + align:start position:0% +now switching gears a little bit this + + + align:start position:0% +now switching gears a little bit this +uh this is more sort of getting into the + + align:start position:0% +uh this is more sort of getting into the + + + align:start position:0% +uh this is more sort of getting into the +human perception of color and i'm not + + align:start position:0% +human perception of color and i'm not + + + align:start position:0% +human perception of color and i'm not +going to get into too many details just + + align:start position:0% +going to get into too many details just + + + align:start position:0% +going to get into too many details just +a very high level uh overview so + + align:start position:0% +a very high level uh overview so + + + align:start position:0% +a very high level uh overview so +uh have many of you looked at this + + align:start position:0% +uh have many of you looked at this + + + align:start position:0% +uh have many of you looked at this +figure before this chromaticity diagram + + align:start position:0% +figure before this chromaticity diagram + + + align:start position:0% +figure before this chromaticity diagram +so what this uh really ha this this is + + align:start position:0% +so what this uh really ha this this is + + + align:start position:0% +so what this uh really ha this this is +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the the thing that people use in order + + align:start position:0% +the the thing that people use in order + + + align:start position:0% +the the thing that people use in order +to see how humans are actually sensing + + align:start position:0% +to see how humans are actually sensing + + + align:start position:0% +to see how humans are actually sensing +color + + align:start position:0% +color + + + align:start position:0% +color +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +what you have along over here is + + align:start position:0% +what you have along over here is + + + align:start position:0% +what you have along over here is +is is each of the each of the + + align:start position:0% +is is each of the each of the + + + align:start position:0% +is is each of the each of the +the spectrally pure colors so going from + + align:start position:0% +the spectrally pure colors so going from + + + align:start position:0% +the spectrally pure colors so going from +400 to 700 nanometers and everything + + align:start position:0% +400 to 700 nanometers and everything + + + align:start position:0% +400 to 700 nanometers and everything +inside so you have this blue over here + + align:start position:0% +inside so you have this blue over here + + + align:start position:0% +inside so you have this blue over here +going to green and then red over here + + align:start position:0% +going to green and then red over here + + + align:start position:0% +going to green and then red over here +and uh anything that's inside is + + align:start position:0% +and uh anything that's inside is + + + align:start position:0% +and uh anything that's inside is +basically a combination of + + align:start position:0% +basically a combination of + + + align:start position:0% +basically a combination of +uh many multiple of these colors are + + align:start position:0% +uh many multiple of these colors are + + + align:start position:0% +uh many multiple of these colors are +that are on the outside + + align:start position:0% +that are on the outside + + + align:start position:0% +that are on the outside +so it turns out that most devices + + align:start position:0% +so it turns out that most devices + + + align:start position:0% +so it turns out that most devices +actually cannot so this is this actually + + align:start position:0% +actually cannot so this is this actually + + + align:start position:0% +actually cannot so this is this actually +represents the space of all colors that + + align:start position:0% +represents the space of all colors that + + + align:start position:0% +represents the space of all colors that +the human eye can detect + + align:start position:0% +the human eye can detect + + + align:start position:0% +the human eye can detect +it turns out that most devices actually + + align:start position:0% +it turns out that most devices actually + + + align:start position:0% +it turns out that most devices actually +occupy a much smaller space within this + + align:start position:0% +occupy a much smaller space within this + + + align:start position:0% +occupy a much smaller space within this +whole chromaticity diagram of this + + align:start position:0% +whole chromaticity diagram of this + + + align:start position:0% +whole chromaticity diagram of this +horseshoe shape thing + + align:start position:0% +horseshoe shape thing + + + align:start position:0% +horseshoe shape thing +and so srgb which is sort of the default + + align:start position:0% +and so srgb which is sort of the default + + + align:start position:0% +and so srgb which is sort of the default +color of most crt monitors and it's the + + align:start position:0% +color of most crt monitors and it's the + + + align:start position:0% +color of most crt monitors and it's the +default color that's used on the + + align:start position:0% +default color that's used on the + + + align:start position:0% +default color that's used on the +internet + + align:start position:0% +internet + + + align:start position:0% +internet +is actually a much smaller region it's + + align:start position:0% +is actually a much smaller region it's + + + align:start position:0% +is actually a much smaller region it's +you can only represent colors that are + + align:start position:0% +you can only represent colors that are + + + align:start position:0% +you can only represent colors that are +in between this triangle in srgb now + + align:start position:0% +in between this triangle in srgb now + + + align:start position:0% +in between this triangle in srgb now +what's interesting with this color space + + align:start position:0% +what's interesting with this color space + + + align:start position:0% +what's interesting with this color space +is that once you have these three + + align:start position:0% +is that once you have these three + + + align:start position:0% +is that once you have these three +um + + align:start position:0% +um + + + align:start position:0% +um +these three points any point that's + + align:start position:0% +these three points any point that's + + + align:start position:0% +these three points any point that's +inside this triangle can actually be + + align:start position:0% +inside this triangle can actually be + + + align:start position:0% +inside this triangle can actually be +represented by a sum of just these three + + align:start position:0% +represented by a sum of just these three + + + align:start position:0% +represented by a sum of just these three +color primaries + + align:start position:0% +color primaries + + + align:start position:0% +color primaries +so that's + + align:start position:0% +so that's + + + align:start position:0% +so that's +what i mean by fixed color primary is + + align:start position:0% +what i mean by fixed color primary is + + + align:start position:0% +what i mean by fixed color primary is +that most cameras that have a single + + align:start position:0% +that most cameras that have a single + + + align:start position:0% +that most cameras that have a single +green single red and single uh blue + + align:start position:0% +green single red and single uh blue + + + align:start position:0% +green single red and single uh blue +filter on the sensor actually have the + + align:start position:0% +filter on the sensor actually have the + + + align:start position:0% +filter on the sensor actually have the +green is somewhere over here blue is + + align:start position:0% +green is somewhere over here blue is + + + align:start position:0% +green is somewhere over here blue is +somewhere here it is somewhere here and + + align:start position:0% +somewhere here it is somewhere here and + + + align:start position:0% +somewhere here it is somewhere here and +that allows you to represent any color + + align:start position:0% +that allows you to represent any color + + + align:start position:0% +that allows you to represent any color +that lies within this + + align:start position:0% +that lies within this + + + align:start position:0% +that lies within this +triangle + + align:start position:0% +triangle + + + align:start position:0% +triangle +now + + align:start position:0% +now + + + align:start position:0% +now +that's sort of what the color response + + align:start position:0% +that's sort of what the color response + + + align:start position:0% +that's sort of what the color response +of a traditional film and that's what it + + align:start position:0% +of a traditional film and that's what it + + + align:start position:0% +of a traditional film and that's what it +looks like for most cameras so it's very + + align:start position:0% +looks like for most cameras so it's very + + + align:start position:0% +looks like for most cameras so it's very +similar there is very little difference + + align:start position:0% +similar there is very little difference + + + align:start position:0% +similar there is very little difference +between the color response of the two + + align:start position:0% +between the color response of the two + + + align:start position:0% +between the color response of the two +and in both cases the response is made + + align:start position:0% +and in both cases the response is made + + + align:start position:0% +and in both cases the response is made +to + + align:start position:0% +to + + + align:start position:0% +to +uh closely implement that of the human + + align:start position:0% +uh closely implement that of the human + + + align:start position:0% +uh closely implement that of the human +eye itself + + align:start position:0% +eye itself + + + align:start position:0% +eye itself +except for in film where like this film + + align:start position:0% +except for in film where like this film + + + align:start position:0% +except for in film where like this film +will be i think is something that's very + + align:start position:0% +will be i think is something that's very + + + align:start position:0% +will be i think is something that's very +good for nature photography so they + + align:start position:0% +good for nature photography so they + + + align:start position:0% +good for nature photography so they +stress more on the red than + + align:start position:0% +stress more on the red than + + + align:start position:0% +stress more on the red than +uh what a digital camera does just + + align:start position:0% +uh what a digital camera does just + + + align:start position:0% +uh what a digital camera does just +because that's it's a little unnatural + + align:start position:0% +because that's it's a little unnatural + + + align:start position:0% +because that's it's a little unnatural +the colors come the colorway is for uh + + align:start position:0% +the colors come the colorway is for uh + + + align:start position:0% +the colors come the colorway is for uh +ocean photography it's any + + align:start position:0% +ocean photography it's any + + + align:start position:0% +ocean photography it's any +landscape kind of thing sunrises sunsets + + align:start position:0% +landscape kind of thing sunrises sunsets + + + align:start position:0% +landscape kind of thing sunrises sunsets +nature it doesn't work very well for + + align:start position:0% +nature it doesn't work very well for + + + align:start position:0% +nature it doesn't work very well for +skin tone for example + + align:start position:0% + + + + align:start position:0% + +so this works fine as long as your color + + align:start position:0% +so this works fine as long as your color + + + align:start position:0% +so this works fine as long as your color +is within this triangle but once you + + align:start position:0% +is within this triangle but once you + + + align:start position:0% +is within this triangle but once you +want to represent a color that's outside + + align:start position:0% +want to represent a color that's outside + + + align:start position:0% +want to represent a color that's outside +it becomes + + align:start position:0% +it becomes + + + align:start position:0% +it becomes +it's not possible to do that because + + align:start position:0% +it's not possible to do that because + + + align:start position:0% +it's not possible to do that because +this rgb the values can only be between + + align:start position:0% +this rgb the values can only be between + + + align:start position:0% +this rgb the values can only be between +0 and 1. so there are a number of + + align:start position:0% +0 and 1. so there are a number of + + + align:start position:0% +0 and 1. so there are a number of +algorithms that you can use in order to + + align:start position:0% +algorithms that you can use in order to + + + align:start position:0% +algorithms that you can use in order to +estimate what the color should be but + + align:start position:0% +estimate what the color should be but + + + align:start position:0% +estimate what the color should be but +each of them is sort of a lossy + + align:start position:0% +each of them is sort of a lossy + + + align:start position:0% +each of them is sort of a lossy +algorithm you lose information because + + align:start position:0% +algorithm you lose information because + + + align:start position:0% +algorithm you lose information because +you may project it to the nearest point + + align:start position:0% +you may project it to the nearest point + + + align:start position:0% +you may project it to the nearest point +or you may project it to the + + align:start position:0% +or you may project it to the + + + align:start position:0% +or you may project it to the +perceptually nearest point and all those + + align:start position:0% +perceptually nearest point and all those + + + align:start position:0% +perceptually nearest point and all those +kind of things but eventually you end up + + align:start position:0% +kind of things but eventually you end up + + + align:start position:0% +kind of things but eventually you end up +losing this information + + align:start position:0% +losing this information + + + align:start position:0% +losing this information +so it turns out like all this region + + align:start position:0% +so it turns out like all this region + + + align:start position:0% +so it turns out like all this region +over here it's very hard to represent + + align:start position:0% +over here it's very hard to represent + + + align:start position:0% +over here it's very hard to represent +colors over here just because your + + align:start position:0% +colors over here just because your + + + align:start position:0% +colors over here just because your +triangle is actually it's it's outside + + align:start position:0% +triangle is actually it's it's outside + + + align:start position:0% +triangle is actually it's it's outside +this triangle + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +one alternative you can do is that + + align:start position:0% +one alternative you can do is that + + + align:start position:0% +one alternative you can do is that +instead of using + + align:start position:0% +instead of using + + + align:start position:0% +instead of using +putting your color primary over here you + + align:start position:0% +putting your color primary over here you + + + align:start position:0% +putting your color primary over here you +can put your color primary out there so + + align:start position:0% +can put your color primary out there so + + + align:start position:0% +can put your color primary out there so +now you have this really big color gamut + + align:start position:0% +now you have this really big color gamut + + + align:start position:0% +now you have this really big color gamut +and you can represent all colors that + + align:start position:0% +and you can represent all colors that + + + align:start position:0% +and you can represent all colors that +lie inside this color space + + align:start position:0% +lie inside this color space + + + align:start position:0% +lie inside this color space +unfortunately what that means is that + + align:start position:0% +unfortunately what that means is that + + + align:start position:0% +unfortunately what that means is that +your green is now very close to let's + + align:start position:0% +your green is now very close to let's + + + align:start position:0% +your green is now very close to let's +say 520 nanometers here so it's a very + + align:start position:0% +say 520 nanometers here so it's a very + + + align:start position:0% +say 520 nanometers here so it's a very +spectacularly pure it's like just one + + align:start position:0% +spectacularly pure it's like just one + + + align:start position:0% +spectacularly pure it's like just one +very narrow range of wavelengths like + + align:start position:0% +very narrow range of wavelengths like + + + align:start position:0% +very narrow range of wavelengths like +that over there and that means you have + + align:start position:0% +that over there and that means you have + + + align:start position:0% +that over there and that means you have +to use a very + + align:start position:0% +to use a very + + + align:start position:0% +to use a very +sharp wavelength profile led or a laser + + align:start position:0% +sharp wavelength profile led or a laser + + + align:start position:0% +sharp wavelength profile led or a laser +or something of that sort of here + + align:start position:0% +or something of that sort of here + + + align:start position:0% +or something of that sort of here +illuminating it or a + + align:start position:0% +illuminating it or a + + + align:start position:0% +illuminating it or a +filter that's really dark so it turns + + align:start position:0% +filter that's really dark so it turns + + + align:start position:0% +filter that's really dark so it turns +out that these + + align:start position:0% +out that these + + + align:start position:0% +out that these +optimal color + + align:start position:0% +optimal color + + + align:start position:0% +optimal color +color gamuts that you have they're a + + align:start position:0% +color gamuts that you have they're a + + + align:start position:0% +color gamuts that you have they're a +very good compromise between having a + + align:start position:0% +very good compromise between having a + + + align:start position:0% +very good compromise between having a +white gamma and having filters that + + align:start position:0% +white gamma and having filters that + + + align:start position:0% +white gamma and having filters that +allow + + align:start position:0% +allow + + + align:start position:0% +allow +a large amount of power to come into the + + align:start position:0% +a large amount of power to come into the + + + align:start position:0% +a large amount of power to come into the +into the system so if you have these uh + + align:start position:0% +into the system so if you have these uh + + + align:start position:0% +into the system so if you have these uh +pro these uh + + align:start position:0% +pro these uh + + + align:start position:0% +pro these uh +primaries very close to the edges you + + align:start position:0% +primaries very close to the edges you + + + align:start position:0% +primaries very close to the edges you +end up throwing away too much of the + + align:start position:0% +end up throwing away too much of the + + + align:start position:0% +end up throwing away too much of the +light you get very little light coming + + align:start position:0% +light you get very little light coming + + + align:start position:0% +light you get very little light coming +in + + align:start position:0% + + + + align:start position:0% + +so what you'd ideally want to do is have + + align:start position:0% +so what you'd ideally want to do is have + + + align:start position:0% +so what you'd ideally want to do is have +these sort of adaptive color primaries + + align:start position:0% +these sort of adaptive color primaries + + + align:start position:0% +these sort of adaptive color primaries +for so for a scene like this you don't + + align:start position:0% +for so for a scene like this you don't + + + align:start position:0% +for so for a scene like this you don't +have too many reds in this for example + + align:start position:0% +have too many reds in this for example + + + align:start position:0% +have too many reds in this for example +you want color primaries to sort of be + + align:start position:0% +you want color primaries to sort of be + + + align:start position:0% +you want color primaries to sort of be +like this that's just some arbitrary + + align:start position:0% +like this that's just some arbitrary + + + align:start position:0% +like this that's just some arbitrary +shape + + align:start position:0% +shape + + + align:start position:0% +shape +and for a scene like this you want them + + align:start position:0% +and for a scene like this you want them + + + align:start position:0% +and for a scene like this you want them +to be more like that rather than have + + align:start position:0% +to be more like that rather than have + + + align:start position:0% +to be more like that rather than have +the same set of color primaries for + + align:start position:0% +the same set of color primaries for + + + align:start position:0% +the same set of color primaries for +every image that you capture you want + + align:start position:0% +every image that you capture you want + + + align:start position:0% +every image that you capture you want +you want to be a little more adaptive + + align:start position:0% +you want to be a little more adaptive + + + align:start position:0% +you want to be a little more adaptive +about it you may want to give the audio + + align:start position:0% +about it you may want to give the audio + + + align:start position:0% +about it you may want to give the audio +this has an analogy here + + align:start position:0% +this has an analogy here + + + align:start position:0% +this has an analogy here +so it's kind of like the the equalizer + + align:start position:0% +so it's kind of like the the equalizer + + + align:start position:0% +so it's kind of like the the equalizer +you mean + + align:start position:0% +you mean + + + align:start position:0% +you mean +so you want to be able to tweak the + + align:start position:0% +so you want to be able to tweak the + + + align:start position:0% +so you want to be able to tweak the +various wavelengths the what wavelength + + align:start position:0% +various wavelengths the what wavelength + + + align:start position:0% +various wavelengths the what wavelength +should be sensed more and what should be + + align:start position:0% +should be sensed more and what should be + + + align:start position:0% +should be sensed more and what should be +sensed less + + align:start position:0% +sensed less + + + align:start position:0% +sensed less +and if you're playing you know pop music + + align:start position:0% +and if you're playing you know pop music + + + align:start position:0% +and if you're playing you know pop music +versus classical music + + align:start position:0% +versus classical music + + + align:start position:0% +versus classical music +you may want to change your synthesizer + + align:start position:0% +you may want to change your synthesizer + + + align:start position:0% +you may want to change your synthesizer +more pass less treble and so on + + align:start position:0% +more pass less treble and so on + + + align:start position:0% +more pass less treble and so on +and because those those settings on your + + align:start position:0% +and because those those settings on your + + + align:start position:0% +and because those those settings on your +equalizer + + align:start position:0% +equalizer + + + align:start position:0% +equalizer +are also boosting certain frequencies + + align:start position:0% +are also boosting certain frequencies + + + align:start position:0% +are also boosting certain frequencies +and + + align:start position:0% +and + + + align:start position:0% +and +and attenuating other frequencies + + align:start position:0% +and attenuating other frequencies + + + align:start position:0% +and attenuating other frequencies +in case of cameras the rgb has already + + align:start position:0% +in case of cameras the rgb has already + + + align:start position:0% +in case of cameras the rgb has already +been fixed the extra exact three points + + align:start position:0% +been fixed the extra exact three points + + + align:start position:0% +been fixed the extra exact three points +and those three points have been fixed + + align:start position:0% +and those three points have been fixed + + + align:start position:0% +and those three points have been fixed +but + + align:start position:0% +but + + + align:start position:0% +but +maybe you want to change them depending + + align:start position:0% +maybe you want to change them depending + + + align:start position:0% +maybe you want to change them depending +on the scene + + align:start position:0% + + + + align:start position:0% + +so that's what i'm going to briefly talk + + align:start position:0% +so that's what i'm going to briefly talk + + + align:start position:0% +so that's what i'm going to briefly talk +about how one way of doing that and uh + + align:start position:0% +about how one way of doing that and uh + + + align:start position:0% +about how one way of doing that and uh +is everyone aware that we talked about + + align:start position:0% +is everyone aware that we talked about + + + align:start position:0% +is everyone aware that we talked about +light fields + + align:start position:0% +light fields + + + align:start position:0% +light fields +i have a question + + align:start position:0% +i have a question + + + align:start position:0% +i have a question +so here in this graph the chromosome + + align:start position:0% +so here in this graph the chromosome + + + align:start position:0% +so here in this graph the chromosome +chromaticity diagram + + align:start position:0% +chromaticity diagram + + + align:start position:0% +chromaticity diagram +it seems like you can represent it in a + + align:start position:0% +it seems like you can represent it in a + + + align:start position:0% +it seems like you can represent it in a +2d plane right yeah so which would mean + + align:start position:0% +2d plane right yeah so which would mean + + + align:start position:0% +2d plane right yeah so which would mean +that + + align:start position:0% +that + + + align:start position:0% +that +two primaries are enough to define any + + align:start position:0% +two primaries are enough to define any + + + align:start position:0% +two primaries are enough to define any +color because it's just a 2d plane so + + align:start position:0% +color because it's just a 2d plane so + + + align:start position:0% +color because it's just a 2d plane so +there's also intensity there's intensity + + align:start position:0% +there's also intensity there's intensity + + + align:start position:0% +there's also intensity there's intensity +which is sort of it's this is a + + align:start position:0% +which is sort of it's this is a + + + align:start position:0% +which is sort of it's this is a +projection of the whole oh so it's + + align:start position:0% +projection of the whole oh so it's + + + align:start position:0% +projection of the whole oh so it's +actually a 3d thing but yeah okay + + align:start position:0% +actually a 3d thing but yeah okay + + + align:start position:0% +actually a 3d thing but yeah okay +yeah but in terms of + + align:start position:0% +yeah but in terms of + + + align:start position:0% +yeah but in terms of +the color you're right you could + + align:start position:0% +the color you're right you could + + + align:start position:0% +the color you're right you could +represent with two numbers and the third + + align:start position:0% +represent with two numbers and the third + + + align:start position:0% +represent with two numbers and the third +one is the intensity and that's why you + + align:start position:0% +one is the intensity and that's why you + + + align:start position:0% +one is the intensity and that's why you +have luv or lab where one is luminance + + align:start position:0% +have luv or lab where one is luminance + + + align:start position:0% +have luv or lab where one is luminance +and there's a and b which is + + align:start position:0% +and there's a and b which is + + + align:start position:0% +and there's a and b which is +chromaticity a and chromaticity okay + + align:start position:0% +chromaticity a and chromaticity okay + + + align:start position:0% +chromaticity a and chromaticity okay +or + + align:start position:0% +or + + + align:start position:0% +or +by uv is the old one + + align:start position:0% +by uv is the old one + + + align:start position:0% +by uv is the old one +like one of the things that that these + + align:start position:0% +like one of the things that that these + + + align:start position:0% +like one of the things that that these +so this + + align:start position:0% +so this + + + align:start position:0% +so this +when i said this is the rgb color space + + align:start position:0% +when i said this is the rgb color space + + + align:start position:0% +when i said this is the rgb color space +is actually incomplete just defining rgb + + align:start position:0% +is actually incomplete just defining rgb + + + align:start position:0% +is actually incomplete just defining rgb +is not enough you need to define the + + align:start position:0% +is not enough you need to define the + + + align:start position:0% +is not enough you need to define the +white point inside where is the white + + align:start position:0% +white point inside where is the white + + + align:start position:0% +white point inside where is the white +and that's sort of also something that's + + align:start position:0% +and that's sort of also something that's + + + align:start position:0% +and that's sort of also something that's +defined over there and that if you look + + align:start position:0% +defined over there and that if you look + + + align:start position:0% +defined over there and that if you look +in the three third dimension that's what + + align:start position:0% +in the three third dimension that's what + + + align:start position:0% +in the three third dimension that's what +represent the various levels of gray + + align:start position:0% +represent the various levels of gray + + + align:start position:0% +represent the various levels of gray +so in order to represent the intensity + + align:start position:0% +so in order to represent the intensity + + + align:start position:0% +so in order to represent the intensity +you need that third axis + + align:start position:0% +you need that third axis + + + align:start position:0% +you need that third axis +and let me emphasize something that is + + align:start position:0% +and let me emphasize something that is + + + align:start position:0% +and let me emphasize something that is +easy to lose i think in this + + align:start position:0% +easy to lose i think in this + + + align:start position:0% +easy to lose i think in this +we tend to use the words color and + + align:start position:0% +we tend to use the words color and + + + align:start position:0% +we tend to use the words color and +wavelength interchangeably in some + + align:start position:0% +wavelength interchangeably in some + + + align:start position:0% +wavelength interchangeably in some +situations and + + align:start position:0% +situations and + + + align:start position:0% +situations and +wavelength is a + + align:start position:0% +wavelength is a + + + align:start position:0% +wavelength is a +truly physical + + align:start position:0% +truly physical + + + align:start position:0% +truly physical +phenomenon it's a property + + align:start position:0% +phenomenon it's a property + + + align:start position:0% +phenomenon it's a property +universe you know of the light itself + + align:start position:0% +universe you know of the light itself + + + align:start position:0% +universe you know of the light itself +color + + align:start position:0% +color + + + align:start position:0% +color +is + + align:start position:0% +is + + + align:start position:0% +is +specific to human vision maybe other + + align:start position:0% +specific to human vision maybe other + + + align:start position:0% +specific to human vision maybe other +animals too but you know it's different + + align:start position:0% +animals too but you know it's different + + + align:start position:0% +animals too but you know it's different +for them than it is for us so when we + + align:start position:0% +for them than it is for us so when we + + + align:start position:0% +for them than it is for us so when we +when we talk about turning wavelength + + align:start position:0% +when we talk about turning wavelength + + + align:start position:0% +when we talk about turning wavelength +into color what we're talking about is + + align:start position:0% +into color what we're talking about is + + + align:start position:0% +into color what we're talking about is +the process of + + align:start position:0% +the process of + + + align:start position:0% +the process of +human perception + + align:start position:0% +human perception + + + align:start position:0% +human perception +and so + + align:start position:0% +and so + + + align:start position:0% +and so +this this plot for example is specific + + align:start position:0% +this this plot for example is specific + + + align:start position:0% +this this plot for example is specific +to human vision if it were some other + + align:start position:0% +to human vision if it were some other + + + align:start position:0% +to human vision if it were some other +creature or some + + align:start position:0% +creature or some + + + align:start position:0% +creature or some +physical device that we built it would + + align:start position:0% +physical device that we built it would + + + align:start position:0% +physical device that we built it would +have a completely different + + align:start position:0% +have a completely different + + + align:start position:0% +have a completely different +plot + + align:start position:0% + + + + align:start position:0% + +before we get on to the color sensing + + align:start position:0% +before we get on to the color sensing + + + align:start position:0% +before we get on to the color sensing +here's an interesting puzzle + + align:start position:0% +here's an interesting puzzle + + + align:start position:0% +here's an interesting puzzle +uh if you take a a red laser pointer + + align:start position:0% +uh if you take a a red laser pointer + + + align:start position:0% +uh if you take a a red laser pointer +uh which we're using red color for it + + align:start position:0% +uh which we're using red color for it + + + align:start position:0% +uh which we're using red color for it +now and as mike just reminded us don't + + align:start position:0% +now and as mike just reminded us don't + + + align:start position:0% +now and as mike just reminded us don't +think of color think of the wavelength + + align:start position:0% +think of color think of the wavelength + + + align:start position:0% +think of color think of the wavelength +so let's say it has certain wavelength i + + align:start position:0% +so let's say it has certain wavelength i + + + align:start position:0% +so let's say it has certain wavelength i +don't know 680 nanometers or something + + align:start position:0% +don't know 680 nanometers or something + + + align:start position:0% +don't know 680 nanometers or something +like that six six thirty six thirty okay + + align:start position:0% +like that six six thirty six thirty okay + + + align:start position:0% +like that six six thirty six thirty okay +and if i just take the laser pointer and + + align:start position:0% +and if i just take the laser pointer and + + + align:start position:0% +and if i just take the laser pointer and +shine it in a little piece of a piece of + + align:start position:0% +shine it in a little piece of a piece of + + + align:start position:0% +shine it in a little piece of a piece of +water a piece of glass or a tank of + + align:start position:0% +water a piece of glass or a tank of + + + align:start position:0% +water a piece of glass or a tank of +water + + align:start position:0% +water + + + align:start position:0% +water +okay what's going to happen to it + + align:start position:0% +okay what's going to happen to it + + + align:start position:0% +okay what's going to happen to it +so i have + + align:start position:0% +so i have + + + align:start position:0% +so i have +a tank a shine laser in it + + align:start position:0% +a tank a shine laser in it + + + align:start position:0% +a tank a shine laser in it +what happens to it + + align:start position:0% + + + + align:start position:0% + +it bends + + align:start position:0% +it bends + + + align:start position:0% +it bends +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and um why does it bend + + align:start position:0% +and um why does it bend + + + align:start position:0% +and um why does it bend +does anything change about its physical + + align:start position:0% +does anything change about its physical + + + align:start position:0% +does anything change about its physical +properties + + align:start position:0% + + + + align:start position:0% + +of course it does + + align:start position:0% +of course it does + + + align:start position:0% +of course it does +either the wavelength or speed or + + align:start position:0% +either the wavelength or speed or + + + align:start position:0% +either the wavelength or speed or +frequency something has to change + + align:start position:0% +frequency something has to change + + + align:start position:0% +frequency something has to change +right the speed is actually decreasing + + align:start position:0% +right the speed is actually decreasing + + + align:start position:0% +right the speed is actually decreasing +right so + + align:start position:0% +right so + + + align:start position:0% +right so +c + + align:start position:0% +c + + + align:start position:0% +c +in air versus c in water + + align:start position:0% +in air versus c in water + + + align:start position:0% +in air versus c in water +is related by a factor of what + + align:start position:0% +is related by a factor of what + + + align:start position:0% +is related by a factor of what +one particular there is a refractive + + align:start position:0% +one particular there is a refractive + + + align:start position:0% +one particular there is a refractive +index + + align:start position:0% +index + + + align:start position:0% +index +right so this is actually + + align:start position:0% +right so this is actually + + + align:start position:0% +right so this is actually +uh + + align:start position:0% +uh + + + align:start position:0% +uh +reduced by a factor of + + align:start position:0% +reduced by a factor of + + + align:start position:0% +reduced by a factor of +two-thirds + + align:start position:0% + + + + align:start position:0% + +now we know that here we have + + align:start position:0% +now we know that here we have + + + align:start position:0% +now we know that here we have +wavelength of light times + + align:start position:0% +wavelength of light times + + + align:start position:0% +wavelength of light times +the frequency of light + + align:start position:0% +the frequency of light + + + align:start position:0% +the frequency of light +i'm just talking about a for air this is + + align:start position:0% +i'm just talking about a for air this is + + + align:start position:0% +i'm just talking about a for air this is +for a laser and similarly here we have + + align:start position:0% +for a laser and similarly here we have + + + align:start position:0% +for a laser and similarly here we have +wavelength in water + + align:start position:0% +wavelength in water + + + align:start position:0% +wavelength in water +times frequency in water + + align:start position:0% +times frequency in water + + + align:start position:0% +times frequency in water +right so this has gone down by + + align:start position:0% +right so this has gone down by + + + align:start position:0% +right so this has gone down by +two thirds + + align:start position:0% +two thirds + + + align:start position:0% +two thirds +something here also has to go down by a + + align:start position:0% +something here also has to go down by a + + + align:start position:0% +something here also has to go down by a +factor of 230 + + align:start position:0% +factor of 230 + + + align:start position:0% +factor of 230 +right yes so everything frequency is + + align:start position:0% +right yes so everything frequency is + + + align:start position:0% +right yes so everything frequency is +fixed yeah the frequency is coming right + + align:start position:0% +fixed yeah the frequency is coming right + + + align:start position:0% +fixed yeah the frequency is coming right +so the wavelength has changed + + align:start position:0% +so the wavelength has changed + + + align:start position:0% +so the wavelength has changed +so um that means + + align:start position:0% +so um that means + + + align:start position:0% +so um that means +from 6 30 you said + + align:start position:0% +from 6 30 you said + + + align:start position:0% +from 6 30 you said +from 6 + + align:start position:0% +from 6 + + + align:start position:0% +from 6 +we have gone down to two thirds of that + + align:start position:0% +we have gone down to two thirds of that + + + align:start position:0% +we have gone down to two thirds of that +so that would be what um + + align:start position:0% +so that would be what um + + + align:start position:0% +so that would be what um + + align:start position:0% + + + align:start position:0% +right + + align:start position:0% +right + + + align:start position:0% +right +so now this red laser is actually + + align:start position:0% +so now this red laser is actually + + + align:start position:0% +so now this red laser is actually +has a wavelength of 420 nanometers + + align:start position:0% +has a wavelength of 420 nanometers + + + align:start position:0% +has a wavelength of 420 nanometers +and so we started from somewhere here + + align:start position:0% +and so we started from somewhere here + + + align:start position:0% +and so we started from somewhere here +and the light wavelength is actually now + + align:start position:0% +and the light wavelength is actually now + + + align:start position:0% +and the light wavelength is actually now +even further down + + align:start position:0% +even further down + + + align:start position:0% +even further down +so does it mean + + align:start position:0% +so does it mean + + + align:start position:0% +so does it mean +that when you shine a laser in water + + align:start position:0% +that when you shine a laser in water + + + align:start position:0% +that when you shine a laser in water +it's actually blue + + align:start position:0% +it's actually blue + + + align:start position:0% +it's actually blue +because this wavelength now is forwarded + + align:start position:0% + + + + align:start position:0% + +is it blue well we can't ever see that + + align:start position:0% +is it blue well we can't ever see that + + + align:start position:0% +is it blue well we can't ever see that +because we are + + align:start position:0% +because we are + + + align:start position:0% +because we are +what must reach the air plus it gets out + + align:start position:0% +what must reach the air plus it gets out + + + align:start position:0% +what must reach the air plus it gets out +of the water + + align:start position:0% +of the water + + + align:start position:0% +of the water +okay so when it comes out + + align:start position:0% +okay so when it comes out + + + align:start position:0% +okay so when it comes out +it's back to 6 30 again you could but + + align:start position:0% +it's back to 6 30 again you could but + + + align:start position:0% +it's back to 6 30 again you could but +when it's inside it's 420. you could + + align:start position:0% +when it's inside it's 420. you could + + + align:start position:0% +when it's inside it's 420. you could +immerse a ccd in water for example okay + + align:start position:0% +immerse a ccd in water for example okay + + + align:start position:0% +immerse a ccd in water for example okay +i guess we sense frequency more than + + align:start position:0% +i guess we sense frequency more than + + + align:start position:0% +i guess we sense frequency more than +wavelength yeah very good + + align:start position:0% +wavelength yeah very good + + + align:start position:0% +wavelength yeah very good +right so + + align:start position:0% +right so + + + align:start position:0% +right so +so remember that message + + align:start position:0% +so remember that message + + + align:start position:0% +so remember that message +don't think about color + + align:start position:0% +don't think about color + + + align:start position:0% +don't think about color +think about the physical properties + + align:start position:0% +think about the physical properties + + + align:start position:0% +think about the physical properties +and the way to think about that is + + align:start position:0% +and the way to think about that is + + + align:start position:0% +and the way to think about that is +you may have + + align:start position:0% +you may have + + + align:start position:0% +you may have +different wavelengths + + align:start position:0% +different wavelengths + + + align:start position:0% +different wavelengths +but they mean different things in + + align:start position:0% +but they mean different things in + + + align:start position:0% +but they mean different things in +different media + + align:start position:0% +different media + + + align:start position:0% +different media +in air + + align:start position:0% +in air + + + align:start position:0% +in air +if you really want to think about colors + + align:start position:0% +if you really want to think about colors + + + align:start position:0% +if you really want to think about colors +and air 630 is red in water + + align:start position:0% +and air 630 is red in water + + + align:start position:0% +and air 630 is red in water +420 is red + + align:start position:0% +420 is red + + + align:start position:0% +420 is red +so it gets too confusing so you can use + + align:start position:0% +so it gets too confusing so you can use + + + align:start position:0% +so it gets too confusing so you can use +colors when they're convenient but they + + align:start position:0% +colors when they're convenient but they + + + align:start position:0% +colors when they're convenient but they +start talking about physical interaction + + align:start position:0% +start talking about physical interaction + + + align:start position:0% +start talking about physical interaction +it's better to talk about wavelengths or + + align:start position:0% +it's better to talk about wavelengths or + + + align:start position:0% +it's better to talk about wavelengths or +really something that remains constant + + align:start position:0% +really something that remains constant + + + align:start position:0% +really something that remains constant +which is wrong + + align:start position:0% +which is wrong + + + align:start position:0% +which is wrong +i think the important thing is that um + + align:start position:0% +i think the important thing is that um + + + align:start position:0% +i think the important thing is that um +the energy of the ray remains the same + + align:start position:0% +the energy of the ray remains the same + + + align:start position:0% +the energy of the ray remains the same +it's e is equal to h nu so where it's + + align:start position:0% +it's e is equal to h nu so where it's + + + align:start position:0% +it's e is equal to h nu so where it's +the frequency so that's what the i sense + + align:start position:0% +the frequency so that's what the i sense + + + align:start position:0% +the frequency so that's what the i sense +is it's the inner the energy of the + + align:start position:0% +is it's the inner the energy of the + + + align:start position:0% +is it's the inner the energy of the +electrons that get + + align:start position:0% +electrons that get + + + align:start position:0% +electrons that get +displaced but uh + + align:start position:0% +displaced but uh + + + align:start position:0% +displaced but uh +when so that's why i said for for + + align:start position:0% +when so that's why i said for for + + + align:start position:0% +when so that's why i said for for +whatever reasons when you're talking + + align:start position:0% +whatever reasons when you're talking + + + align:start position:0% +whatever reasons when you're talking +about visible light they always like to + + align:start position:0% +about visible light they always like to + + + align:start position:0% +about visible light they always like to +talk about it with wavelength and + + align:start position:0% +talk about it with wavelength and + + + align:start position:0% +talk about it with wavelength and +it's not entirely correct because as + + align:start position:0% +it's not entirely correct because as + + + align:start position:0% +it's not entirely correct because as +ramesh pointed out this this figure is + + align:start position:0% +ramesh pointed out this this figure is + + + align:start position:0% +ramesh pointed out this this figure is +only true for + + align:start position:0% +only true for + + + align:start position:0% +only true for +for for air and it won't be it would be + + align:start position:0% +for for air and it won't be it would be + + + align:start position:0% +for for air and it won't be it would be +completely diff very different if you + + align:start position:0% +completely diff very different if you + + + align:start position:0% +completely diff very different if you +were under water but it's just a + + align:start position:0% +were under water but it's just a + + + align:start position:0% +were under water but it's just a +convention that people like to follow + + align:start position:0% +convention that people like to follow + + + align:start position:0% +convention that people like to follow +and that's that's what we're sticking + + align:start position:0% +and that's that's what we're sticking + + + align:start position:0% +and that's that's what we're sticking +so you can always ask this question to + + align:start position:0% +so you can always ask this question to + + + align:start position:0% +so you can always ask this question to +your photographer friends + + align:start position:0% +your photographer friends + + + align:start position:0% +your photographer friends +because they like to talk about colors + + align:start position:0% +because they like to talk about colors + + + align:start position:0% +because they like to talk about colors +so again sort of going back over here as + + align:start position:0% +so again sort of going back over here as + + + align:start position:0% +so again sort of going back over here as +i was saying in different sort of + + align:start position:0% +i was saying in different sort of + + + align:start position:0% +i was saying in different sort of +that's why they have both the frequency + + align:start position:0% +that's why they have both the frequency + + + align:start position:0% +that's why they have both the frequency +and the wavelength over here in + + align:start position:0% +and the wavelength over here in + + + align:start position:0% +and the wavelength over here in +different fields and in different re + + align:start position:0% +different fields and in different re + + + align:start position:0% +different fields and in different re +different uh + + align:start position:0% +different uh + + + align:start position:0% +different uh +for different purposes you would use + + align:start position:0% +for different purposes you would use + + + align:start position:0% +for different purposes you would use +either frequency or wavelengths just + + align:start position:0% +either frequency or wavelengths just + + + align:start position:0% +either frequency or wavelengths just +that for photography and for especially + + align:start position:0% +that for photography and for especially + + + align:start position:0% +that for photography and for especially +for + + align:start position:0% +for + + + align:start position:0% +for +this kind of imaging and that too in the + + align:start position:0% +this kind of imaging and that too in the + + + align:start position:0% +this kind of imaging and that too in the +visible region it's something that + + align:start position:0% +visible region it's something that + + + align:start position:0% +visible region it's something that +people usually use wavelength and not + + align:start position:0% +people usually use wavelength and not + + + align:start position:0% +people usually use wavelength and not +the frequency or the energy + + align:start position:0% + + + + align:start position:0% + +so we want to try to come up with a way + + align:start position:0% +so we want to try to come up with a way + + + align:start position:0% +so we want to try to come up with a way +of having sort of adaptive color + + align:start position:0% +of having sort of adaptive color + + + align:start position:0% +of having sort of adaptive color +primaries + + align:start position:0% +primaries + + + align:start position:0% +primaries +and so + + align:start position:0% +and so + + + align:start position:0% +and so +i'm going to go through a sort of + + align:start position:0% +i'm going to go through a sort of + + + align:start position:0% +i'm going to go through a sort of +analysis of an optical system that we + + align:start position:0% +analysis of an optical system that we + + + align:start position:0% +analysis of an optical system that we +developed and it's going everything that + + align:start position:0% +developed and it's going everything that + + + align:start position:0% +developed and it's going everything that +i'm going to discuss is going to have be + + align:start position:0% +i'm going to discuss is going to have be + + + align:start position:0% +i'm going to discuss is going to have be +in what's called the flatland case + + align:start position:0% +in what's called the flatland case + + + align:start position:0% +in what's called the flatland case +so + + align:start position:0% +so + + + align:start position:0% +so +it's just in two dimensions but it + + align:start position:0% +it's just in two dimensions but it + + + align:start position:0% +it's just in two dimensions but it +scales up to a real 3d or 4d case also + + align:start position:0% +scales up to a real 3d or 4d case also + + + align:start position:0% +scales up to a real 3d or 4d case also +so we start with a simple 1d signal and + + align:start position:0% +so we start with a simple 1d signal and + + + align:start position:0% +so we start with a simple 1d signal and +this 1d signal is arbitrary intensity + + align:start position:0% +this 1d signal is arbitrary intensity + + + align:start position:0% +this 1d signal is arbitrary intensity +and along the this is the x position of + + align:start position:0% +and along the this is the x position of + + + align:start position:0% +and along the this is the x position of +the + + align:start position:0% +the + + + align:start position:0% +the +of the signal and this is the intensity + + align:start position:0% +of the signal and this is the intensity + + + align:start position:0% +of the signal and this is the intensity +and it's a white signal which means it + + align:start position:0% +and it's a white signal which means it + + + align:start position:0% +and it's a white signal which means it +has all the visible frequencies between + + align:start position:0% +has all the visible frequencies between + + + align:start position:0% +has all the visible frequencies between +let's say 400 and 700 nanometers and the + + align:start position:0% +let's say 400 and 700 nanometers and the + + + align:start position:0% +let's say 400 and 700 nanometers and the +intensity of each one of those + + align:start position:0% +intensity of each one of those + + + align:start position:0% +intensity of each one of those +wavelengths is actually the same + + align:start position:0% +wavelengths is actually the same + + + align:start position:0% +wavelengths is actually the same +so that's what the wavelength profile or + + align:start position:0% +so that's what the wavelength profile or + + + align:start position:0% +so that's what the wavelength profile or +the color profile spectra profile looks + + align:start position:0% +the color profile spectra profile looks + + + align:start position:0% +the color profile spectra profile looks +like at any point between a and c + + align:start position:0% +like at any point between a and c + + + align:start position:0% +like at any point between a and c +so we take this signal and we put it in + + align:start position:0% +so we take this signal and we put it in + + + align:start position:0% +so we take this signal and we put it in +front of a pinhole + + align:start position:0% +front of a pinhole + + + align:start position:0% +front of a pinhole +so here's your signal and here's the + + align:start position:0% +so here's your signal and here's the + + + align:start position:0% +so here's your signal and here's the +pinhole so the pinhole essentially + + align:start position:0% +pinhole so the pinhole essentially + + + align:start position:0% +pinhole so the pinhole essentially +creates an inverted image of the signal + + align:start position:0% +creates an inverted image of the signal + + + align:start position:0% +creates an inverted image of the signal +so + + align:start position:0% +so + + + align:start position:0% +so +you have this abc here you get a prime b + + align:start position:0% +you have this abc here you get a prime b + + + align:start position:0% +you have this abc here you get a prime b +graph c prime over here it's just a + + align:start position:0% +graph c prime over here it's just a + + + align:start position:0% +graph c prime over here it's just a +pinhole camera + + align:start position:0% +pinhole camera + + + align:start position:0% +pinhole camera +so now instead of + + align:start position:0% +so now instead of + + + align:start position:0% +so now instead of +positioning a + + align:start position:0% +positioning a + + + align:start position:0% +positioning a +film or a sensor over here we put a lens + + align:start position:0% +film or a sensor over here we put a lens + + + align:start position:0% +film or a sensor over here we put a lens +in this plane and this lens essentially + + align:start position:0% +in this plane and this lens essentially + + + align:start position:0% +in this plane and this lens essentially +collimates all these rays so you have a + + align:start position:0% +collimates all these rays so you have a + + + align:start position:0% +collimates all these rays so you have a +prime b times c prime it's just like an + + align:start position:0% +prime b times c prime it's just like an + + + align:start position:0% +prime b times c prime it's just like an +orthographic sort of setup so except + + align:start position:0% +orthographic sort of setup so except + + + align:start position:0% +orthographic sort of setup so except +it's inverted which is not so important + + align:start position:0% +it's inverted which is not so important + + + align:start position:0% +it's inverted which is not so important +but you have array coming in for each + + align:start position:0% +but you have array coming in for each + + + align:start position:0% +but you have array coming in for each +point in the scene + + align:start position:0% +point in the scene + + + align:start position:0% +point in the scene +so next we place a prism in front of + + align:start position:0% +so next we place a prism in front of + + + align:start position:0% +so next we place a prism in front of +this and now as i talked about mentioned + + align:start position:0% +this and now as i talked about mentioned + + + align:start position:0% +this and now as i talked about mentioned +earlier that a prism actually bends the + + align:start position:0% +earlier that a prism actually bends the + + + align:start position:0% +earlier that a prism actually bends the +incoming ray where the bending angle + + align:start position:0% +incoming ray where the bending angle + + + align:start position:0% +incoming ray where the bending angle +actually depends on + + align:start position:0% +actually depends on + + + align:start position:0% +actually depends on +the wavelength of light so what i'm + + align:start position:0% +the wavelength of light so what i'm + + + align:start position:0% +the wavelength of light so what i'm +going to show for simplicity over here + + align:start position:0% +going to show for simplicity over here + + + align:start position:0% +going to show for simplicity over here +is that when you have a white light + + align:start position:0% +is that when you have a white light + + + align:start position:0% +is that when you have a white light +coming in + + align:start position:0% +coming in + + + align:start position:0% +coming in +the green the ray corresponding to the + + align:start position:0% +the green the ray corresponding to the + + + align:start position:0% +the green the ray corresponding to the +green wavelength of 550 nanometers or + + align:start position:0% +green wavelength of 550 nanometers or + + + align:start position:0% +green wavelength of 550 nanometers or +something actually goes through straight + + align:start position:0% +something actually goes through straight + + + align:start position:0% +something actually goes through straight +on bent and red gets bent upwards and + + align:start position:0% +on bent and red gets bent upwards and + + + align:start position:0% +on bent and red gets bent upwards and +blue gets bent downwards now once again + + align:start position:0% +blue gets bent downwards now once again + + + align:start position:0% +blue gets bent downwards now once again +i'm going against what michael was + + align:start position:0% +i'm going against what michael was + + + align:start position:0% +i'm going against what michael was +saying i'm calling it red green and blue + + align:start position:0% +saying i'm calling it red green and blue + + + align:start position:0% +saying i'm calling it red green and blue +but it really is the wavelength 400 500 + + align:start position:0% +but it really is the wavelength 400 500 + + + align:start position:0% +but it really is the wavelength 400 500 +and 700 nanometers i'm just going to + + align:start position:0% +and 700 nanometers i'm just going to + + + align:start position:0% +and 700 nanometers i'm just going to +call red green blue because it's easier + + align:start position:0% +call red green blue because it's easier + + + align:start position:0% +call red green blue because it's easier +to talk of it that way and the other + + align:start position:0% +to talk of it that way and the other + + + align:start position:0% +to talk of it that way and the other +thing to mention uh notice here is that + + align:start position:0% +thing to mention uh notice here is that + + + align:start position:0% +thing to mention uh notice here is that +i'm only drawing these three rays but + + align:start position:0% +i'm only drawing these three rays but + + + align:start position:0% +i'm only drawing these three rays but +really it's a whole fan of rays because + + align:start position:0% +really it's a whole fan of rays because + + + align:start position:0% +really it's a whole fan of rays because +it's a continuum and it's a wide object + + align:start position:0% +it's a continuum and it's a wide object + + + align:start position:0% +it's a continuum and it's a wide object +a whole rainbow basically it you have + + align:start position:0% +a whole rainbow basically it you have + + + align:start position:0% +a whole rainbow basically it you have +the whole rainbow here you i'm just + + align:start position:0% +the whole rainbow here you i'm just + + + align:start position:0% +the whole rainbow here you i'm just +drawing three of those rays so you would + + align:start position:0% +drawing three of those rays so you would + + + align:start position:0% +drawing three of those rays so you would +actually have a ray going down here and + + align:start position:0% +actually have a ray going down here and + + + align:start position:0% +actually have a ray going down here and +up there and anywhere between this blue + + align:start position:0% +up there and anywhere between this blue + + + align:start position:0% +up there and anywhere between this blue +and the red ray that we have + + align:start position:0% +and the red ray that we have + + + align:start position:0% +and the red ray that we have +so now looking at this prism uh more + + align:start position:0% +so now looking at this prism uh more + + + align:start position:0% +so now looking at this prism uh more +closely + + align:start position:0% +closely + + + align:start position:0% +closely +along this axis we have the spatial + + align:start position:0% +along this axis we have the spatial + + + align:start position:0% +along this axis we have the spatial +points of the scene so you have a prime + + align:start position:0% +points of the scene so you have a prime + + + align:start position:0% +points of the scene so you have a prime +b prime and c prime + + align:start position:0% +b prime and c prime + + + align:start position:0% +b prime and c prime +and coming out of each of those points + + align:start position:0% +and coming out of each of those points + + + align:start position:0% +and coming out of each of those points +you have this wavelength angle + + align:start position:0% +you have this wavelength angle + + + align:start position:0% +you have this wavelength angle +uh lambda now + + align:start position:0% +uh lambda now + + + align:start position:0% +uh lambda now +this figure should remind you of + + align:start position:0% +this figure should remind you of + + + align:start position:0% +this figure should remind you of +something and uh + + align:start position:0% +something and uh + + + align:start position:0% +something and uh +anyone + + align:start position:0% +anyone + + + align:start position:0% +anyone +wants to guess like does does this + + align:start position:0% +wants to guess like does does this + + + align:start position:0% +wants to guess like does does this +figure look familiar to + + align:start position:0% +figure look familiar to + + + align:start position:0% +figure look familiar to +us + + align:start position:0% + + + + align:start position:0% + +it's exactly like a light field uh + + align:start position:0% +it's exactly like a light field uh + + + align:start position:0% +it's exactly like a light field uh +except the only difference is that + + align:start position:0% +except the only difference is that + + + align:start position:0% +except the only difference is that +instead of having lambda theta over here + + align:start position:0% +instead of having lambda theta over here + + + align:start position:0% +instead of having lambda theta over here +or the angle we replaced it with lambda + + align:start position:0% +or the angle we replaced it with lambda + + + align:start position:0% +or the angle we replaced it with lambda +so this is something we call the + + align:start position:0% +so this is something we call the + + + align:start position:0% +so this is something we call the +spectral light field it's + + align:start position:0% +spectral light field it's + + + align:start position:0% +spectral light field it's +uh it's it's sort of the angular light + + align:start position:0% +uh it's it's sort of the angular light + + + align:start position:0% +uh it's it's sort of the angular light +field or the spatial light field the + + align:start position:0% +field or the spatial light field the + + + align:start position:0% +field or the spatial light field the +spectral light field so any point over + + align:start position:0% +spectral light field so any point over + + + align:start position:0% +spectral light field so any point over +here in x or lambda will represent the + + align:start position:0% +here in x or lambda will represent the + + + align:start position:0% +here in x or lambda will represent the +intensity of a ray in the space coming + + align:start position:0% +intensity of a ray in the space coming + + + align:start position:0% +intensity of a ray in the space coming +out of some point + + align:start position:0% +out of some point + + + align:start position:0% +out of some point +along a and c and going in a particular + + align:start position:0% +along a and c and going in a particular + + + align:start position:0% +along a and c and going in a particular +direction + + align:start position:0% +direction + + + align:start position:0% +direction +and since we started with a white + + align:start position:0% +and since we started with a white + + + align:start position:0% +and since we started with a white +light source uh it's going to have the + + align:start position:0% +light source uh it's going to have the + + + align:start position:0% +light source uh it's going to have the +same + + align:start position:0% +same + + + align:start position:0% +same +intensity along each of these + + align:start position:0% +intensity along each of these + + + align:start position:0% +intensity along each of these +along each wavelength + + align:start position:0% +along each wavelength + + + align:start position:0% +along each wavelength +so uh it now since we've + + align:start position:0% +so uh it now since we've + + + align:start position:0% +so uh it now since we've +reduce this to nothing more than just a + + align:start position:0% +reduce this to nothing more than just a + + + align:start position:0% +reduce this to nothing more than just a +light field it turns out we can use the + + align:start position:0% +light field it turns out we can use the + + + align:start position:0% +light field it turns out we can use the +various properties of a light field in + + align:start position:0% +various properties of a light field in + + + align:start position:0% +various properties of a light field in +analyzing the system + + align:start position:0% +analyzing the system + + + align:start position:0% +analyzing the system +and the one + + align:start position:0% +and the one + + + align:start position:0% +and the one +again this is something that you should + + align:start position:0% +again this is something that you should + + + align:start position:0% +again this is something that you should +be familiar with if you know what a + + align:start position:0% +be familiar with if you know what a + + + align:start position:0% +be familiar with if you know what a +light field is is that if you place a + + align:start position:0% +light field is is that if you place a + + + align:start position:0% +light field is is that if you place a +screen somewhere in front of a light + + align:start position:0% +screen somewhere in front of a light + + + align:start position:0% +screen somewhere in front of a light +field you get a projection of the light + + align:start position:0% +field you get a projection of the light + + + align:start position:0% +field you get a projection of the light +field on that screen in a direction + + align:start position:0% +field on that screen in a direction + + + align:start position:0% +field on that screen in a direction +perpendicular to the screen in terms of + + align:start position:0% +perpendicular to the screen in terms of + + + align:start position:0% +perpendicular to the screen in terms of +the light field so what that means in + + align:start position:0% +the light field so what that means in + + + align:start position:0% +the light field so what that means in +um in the flashlight case is that now if + + align:start position:0% +um in the flashlight case is that now if + + + align:start position:0% +um in the flashlight case is that now if +i place a light + + align:start position:0% +i place a light + + + align:start position:0% +i place a light +place a screen over here this this thing + + align:start position:0% +place a screen over here this this thing + + + align:start position:0% +place a screen over here this this thing +this yellow thing what that does to the + + align:start position:0% +this yellow thing what that does to the + + + align:start position:0% +this yellow thing what that does to the +light field is basically get a vertical + + align:start position:0% +light field is basically get a vertical + + + align:start position:0% +light field is basically get a vertical +projection which is a direction + + align:start position:0% +projection which is a direction + + + align:start position:0% +projection which is a direction +perpendicular to the direction of the + + align:start position:0% +perpendicular to the direction of the + + + align:start position:0% +perpendicular to the direction of the +screen which is along the x-axis + + align:start position:0% +screen which is along the x-axis + + + align:start position:0% +screen which is along the x-axis +so + + align:start position:0% +so + + + align:start position:0% +so +what we're getting for every point over + + align:start position:0% +what we're getting for every point over + + + align:start position:0% +what we're getting for every point over +here is an integration over the various + + align:start position:0% +here is an integration over the various + + + align:start position:0% +here is an integration over the various +all the wavelengths + + align:start position:0% +all the wavelengths + + + align:start position:0% +all the wavelengths +for that particular x position and you + + align:start position:0% +for that particular x position and you + + + align:start position:0% +for that particular x position and you +essentially get the shape of the signal + + align:start position:0% +essentially get the shape of the signal + + + align:start position:0% +essentially get the shape of the signal +uh in this projection so if you were to + + align:start position:0% +uh in this projection so if you were to + + + align:start position:0% +uh in this projection so if you were to +place a screen over here + + align:start position:0% +place a screen over here + + + align:start position:0% +place a screen over here +not surprisingly you would get an image + + align:start position:0% +not surprisingly you would get an image + + + align:start position:0% +not surprisingly you would get an image +of the signal itself on the screen + + align:start position:0% +of the signal itself on the screen + + + align:start position:0% +of the signal itself on the screen +because it's so close to the prism it's + + align:start position:0% +because it's so close to the prism it's + + + align:start position:0% +because it's so close to the prism it's +these rays haven't dispersed as much yet + + align:start position:0% +these rays haven't dispersed as much yet + + + align:start position:0% +these rays haven't dispersed as much yet +it's almost the same thing as if there + + align:start position:0% +it's almost the same thing as if there + + + align:start position:0% +it's almost the same thing as if there +was no prism present over there + + align:start position:0% +was no prism present over there + + + align:start position:0% +was no prism present over there +but now as you move the screen away from + + align:start position:0% +but now as you move the screen away from + + + align:start position:0% +but now as you move the screen away from +the prism + + align:start position:0% +the prism + + + align:start position:0% +the prism +the angle of projection changes and it + + align:start position:0% +the angle of projection changes and it + + + align:start position:0% +the angle of projection changes and it +becomes more you you get this shear sort + + align:start position:0% +becomes more you you get this shear sort + + + align:start position:0% +becomes more you you get this shear sort +of thing and because of the shear you + + align:start position:0% +of thing and because of the shear you + + + align:start position:0% +of thing and because of the shear you +get the + + align:start position:0% +get the + + + align:start position:0% +get the +various wavelengths the the signal + + align:start position:0% +various wavelengths the the signal + + + align:start position:0% +various wavelengths the the signal +corresponding to the different + + align:start position:0% +corresponding to the different + + + align:start position:0% +corresponding to the different +wavelengths is now dispersed and it's + + align:start position:0% +wavelengths is now dispersed and it's + + + align:start position:0% +wavelengths is now dispersed and it's +overlapping and shifted and once again + + align:start position:0% +overlapping and shifted and once again + + + align:start position:0% +overlapping and shifted and once again +i've shown just the blue green and red + + align:start position:0% +i've shown just the blue green and red + + + align:start position:0% +i've shown just the blue green and red +wavelengths here but really it's a + + align:start position:0% +wavelengths here but really it's a + + + align:start position:0% +wavelengths here but really it's a +continuum and you're getting this + + align:start position:0% +continuum and you're getting this + + + align:start position:0% +continuum and you're getting this +rainbow like smear + + align:start position:0% +rainbow like smear + + + align:start position:0% +rainbow like smear +over here and when you were looking + + align:start position:0% +over here and when you were looking + + + align:start position:0% +over here and when you were looking +through the diffraction grating you + + align:start position:0% +through the diffraction grating you + + + align:start position:0% +through the diffraction grating you +could sort of almost see this you get a + + align:start position:0% +could sort of almost see this you get a + + + align:start position:0% +could sort of almost see this you get a +rainbow coming out of every point when + + align:start position:0% +rainbow coming out of every point when + + + align:start position:0% +rainbow coming out of every point when +you look through it + + align:start position:0% +you look through it + + + align:start position:0% +you look through it +and that's similar to what you're + + align:start position:0% +and that's similar to what you're + + + align:start position:0% +and that's similar to what you're +getting over here + + align:start position:0% +getting over here + + + align:start position:0% +getting over here +now if you move this this plane away to + + align:start position:0% +now if you move this this plane away to + + + align:start position:0% +now if you move this this plane away to +infinity when it's at infinity you're + + align:start position:0% +infinity when it's at infinity you're + + + align:start position:0% +infinity when it's at infinity you're +going to get this horizontal projection + + align:start position:0% +going to get this horizontal projection + + + align:start position:0% +going to get this horizontal projection +through the spectral light + + align:start position:0% +through the spectral light + + + align:start position:0% +through the spectral light +and now for each point on the screen we + + align:start position:0% +and now for each point on the screen we + + + align:start position:0% +and now for each point on the screen we +are integrating over all the spatial + + align:start position:0% +are integrating over all the spatial + + + align:start position:0% +are integrating over all the spatial +positions all all the + + align:start position:0% +positions all all the + + + align:start position:0% +positions all all the +points on the signal for each wavelength + + align:start position:0% +points on the signal for each wavelength + + + align:start position:0% +points on the signal for each wavelength +so what you get on the screen is nothing + + align:start position:0% +so what you get on the screen is nothing + + + align:start position:0% +so what you get on the screen is nothing +but a rainbow because we started with a + + align:start position:0% +but a rainbow because we started with a + + + align:start position:0% +but a rainbow because we started with a +white light source + + align:start position:0% +white light source + + + align:start position:0% +white light source +and you have something going from blue + + align:start position:0% +and you have something going from blue + + + align:start position:0% +and you have something going from blue +to red + + align:start position:0% +to red + + + align:start position:0% +to red +any questions + + align:start position:0% + + + + align:start position:0% + +so what we've done is that we we have + + align:start position:0% +so what we've done is that we we have + + + align:start position:0% +so what we've done is that we we have +this one plane where if we put a screen + + align:start position:0% +this one plane where if we put a screen + + + align:start position:0% +this one plane where if we put a screen +on that plane we get this spectral + + align:start position:0% +on that plane we get this spectral + + + align:start position:0% +on that plane we get this spectral +characteristics of the signal that we + + align:start position:0% +characteristics of the signal that we + + + align:start position:0% +characteristics of the signal that we +started with + + align:start position:0% +started with + + + align:start position:0% +started with +so the problem with that of course is + + align:start position:0% +so the problem with that of course is + + + align:start position:0% +so the problem with that of course is +that this plane is infinitely far away + + align:start position:0% +that this plane is infinitely far away + + + align:start position:0% +that this plane is infinitely far away +but we we want to move it closer so we + + align:start position:0% +but we we want to move it closer so we + + + align:start position:0% +but we we want to move it closer so we +place another lens in front of the prism + + align:start position:0% +place another lens in front of the prism + + + align:start position:0% +place another lens in front of the prism +and this lens does two things the first + + align:start position:0% +and this lens does two things the first + + + align:start position:0% +and this lens does two things the first +is that it creates a copy of the prism + + align:start position:0% +is that it creates a copy of the prism + + + align:start position:0% +is that it creates a copy of the prism +itself on this plane at some distance + + align:start position:0% +itself on this plane at some distance + + + align:start position:0% +itself on this plane at some distance +uh from the lens where basically this is + + align:start position:0% +uh from the lens where basically this is + + + align:start position:0% +uh from the lens where basically this is +image c prime is image at c double prime + + align:start position:0% +image c prime is image at c double prime + + + align:start position:0% +image c prime is image at c double prime +v prime and v double prime and so on so + + align:start position:0% +v prime and v double prime and so on so + + + align:start position:0% +v prime and v double prime and so on so +similar to the x that you had there you + + align:start position:0% +similar to the x that you had there you + + + align:start position:0% +similar to the x that you had there you +get an x over here + + align:start position:0% + + + + align:start position:0% + +but you also get this plane in the + + align:start position:0% +but you also get this plane in the + + + align:start position:0% +but you also get this plane in the +middle where + + align:start position:0% +middle where + + + align:start position:0% +middle where +each ray for each scene point of a + + align:start position:0% +each ray for each scene point of a + + + align:start position:0% +each ray for each scene point of a +particular wavelength actually converges + + align:start position:0% +particular wavelength actually converges + + + align:start position:0% +particular wavelength actually converges +and meets at a point on this plane + + align:start position:0% +and meets at a point on this plane + + + align:start position:0% +and meets at a point on this plane +so all the red trays are meeting here + + align:start position:0% +so all the red trays are meeting here + + + align:start position:0% +so all the red trays are meeting here +green rays are meeting here blue rays + + align:start position:0% +green rays are meeting here blue rays + + + align:start position:0% +green rays are meeting here blue rays +are meeting here and so on + + align:start position:0% + + + + align:start position:0% + +so once again looking at this when you + + align:start position:0% +so once again looking at this when you + + + align:start position:0% +so once again looking at this when you +place a screen at this + + align:start position:0% +place a screen at this + + + align:start position:0% +place a screen at this +plane at the end which is an image of + + align:start position:0% +plane at the end which is an image of + + + align:start position:0% +plane at the end which is an image of +the prism itself you're getting this + + align:start position:0% +the prism itself you're getting this + + + align:start position:0% +the prism itself you're getting this +vertical projection and this is an image + + align:start position:0% +vertical projection and this is an image + + + align:start position:0% +vertical projection and this is an image +of the scene itself and this is where we + + align:start position:0% +of the scene itself and this is where we + + + align:start position:0% +of the scene itself and this is where we +place our sensor and we call this the + + align:start position:0% +place our sensor and we call this the + + + align:start position:0% +place our sensor and we call this the +sensor plane of the optical system + + align:start position:0% +sensor plane of the optical system + + + align:start position:0% +sensor plane of the optical system +and if you look at this plane which + + align:start position:0% +and if you look at this plane which + + + align:start position:0% +and if you look at this plane which +which had this nice cute property of all + + align:start position:0% +which had this nice cute property of all + + + align:start position:0% +which had this nice cute property of all +the reds coming together greens coming + + align:start position:0% +the reds coming together greens coming + + + align:start position:0% +the reds coming together greens coming +together and so on we actually get the + + align:start position:0% +together and so on we actually get the + + + align:start position:0% +together and so on we actually get the +horizontal projection and this is the + + align:start position:0% +horizontal projection and this is the + + + align:start position:0% +horizontal projection and this is the +plane which was at infinity before it's + + align:start position:0% +plane which was at infinity before it's + + + align:start position:0% +plane which was at infinity before it's +moved much closer than that and you get + + align:start position:0% +moved much closer than that and you get + + + align:start position:0% +moved much closer than that and you get +this nice looking rainbow at this plane + + align:start position:0% +this nice looking rainbow at this plane + + + align:start position:0% +this nice looking rainbow at this plane +we call this the rainbow plane + + align:start position:0% + + + + align:start position:0% + +so the nice cute property of the rainbow + + align:start position:0% +so the nice cute property of the rainbow + + + align:start position:0% +so the nice cute property of the rainbow +plane is that that all the rays of a + + align:start position:0% +plane is that that all the rays of a + + + align:start position:0% +plane is that that all the rays of a +given wavelength coming from all the + + align:start position:0% +given wavelength coming from all the + + + align:start position:0% +given wavelength coming from all the +points in the scene actually converge to + + align:start position:0% +points in the scene actually converge to + + + align:start position:0% +points in the scene actually converge to +a single unique point in this plane + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% + + + + align:start position:0% + +just to give you a couple of examples if + + align:start position:0% +just to give you a couple of examples if + + + align:start position:0% +just to give you a couple of examples if +instead of the signal being wide if it + + align:start position:0% +instead of the signal being wide if it + + + align:start position:0% +instead of the signal being wide if it +had been completely red let's say + + align:start position:0% +had been completely red let's say + + + align:start position:0% +had been completely red let's say +between 680 and 700 nanometers or + + align:start position:0% +between 680 and 700 nanometers or + + + align:start position:0% +between 680 and 700 nanometers or +something like that + + align:start position:0% +something like that + + + align:start position:0% +something like that +when you took the this horizontal + + align:start position:0% +when you took the this horizontal + + + align:start position:0% +when you took the this horizontal +projection at tr or the rainbow plane + + align:start position:0% +projection at tr or the rainbow plane + + + align:start position:0% +projection at tr or the rainbow plane +you would only get this part of the + + align:start position:0% +you would only get this part of the + + + align:start position:0% +you would only get this part of the +rainbow you won't get the other + + align:start position:0% +rainbow you won't get the other + + + align:start position:0% +rainbow you won't get the other +remaining rainbow + + align:start position:0% +remaining rainbow + + + align:start position:0% +remaining rainbow +similarly if your + + align:start position:0% +similarly if your + + + align:start position:0% +similarly if your +signal was half blue and half red you + + align:start position:0% +signal was half blue and half red you + + + align:start position:0% +signal was half blue and half red you +would get something like this at the + + align:start position:0% +would get something like this at the + + + align:start position:0% +would get something like this at the +rainbow plane + + align:start position:0% + + + + align:start position:0% + +so now if you place a mask in the + + align:start position:0% +so now if you place a mask in the + + + align:start position:0% +so now if you place a mask in the +rainbow plane let's say you block out + + align:start position:0% +rainbow plane let's say you block out + + + align:start position:0% +rainbow plane let's say you block out +all these red rays that are going + + align:start position:0% +all these red rays that are going + + + align:start position:0% +all these red rays that are going +through you actually put an occluder in + + align:start position:0% +through you actually put an occluder in + + + align:start position:0% +through you actually put an occluder in +that plane + + align:start position:0% +that plane + + + align:start position:0% +that plane +when you what what that essentially does + + align:start position:0% +when you what what that essentially does + + + align:start position:0% +when you what what that essentially does +is that it multiplies the incoming light + + align:start position:0% +is that it multiplies the incoming light + + + align:start position:0% +is that it multiplies the incoming light +field at this plane which is this with + + align:start position:0% +field at this plane which is this with + + + align:start position:0% +field at this plane which is this with +with a light field which is all zeros + + align:start position:0% +with a light field which is all zeros + + + align:start position:0% +with a light field which is all zeros +corresponding to the + + align:start position:0% +corresponding to the + + + align:start position:0% +corresponding to the +wavelengths + + align:start position:0% +wavelengths + + + align:start position:0% +wavelengths +that that you block and all ones + + align:start position:0% +that that you block and all ones + + + align:start position:0% +that that you block and all ones +corresponding to the all to all the + + align:start position:0% +corresponding to the all to all the + + + align:start position:0% +corresponding to the all to all the +other wavelengths and so what you get is + + align:start position:0% +other wavelengths and so what you get is + + + align:start position:0% +other wavelengths and so what you get is +basically this + + align:start position:0% +basically this + + + align:start position:0% +basically this +what looks kind of like this and now + + align:start position:0% +what looks kind of like this and now + + + align:start position:0% +what looks kind of like this and now +when you put the sensor at + + align:start position:0% +when you put the sensor at + + + align:start position:0% +when you put the sensor at +the screen at the sensor plane and you + + align:start position:0% +the screen at the sensor plane and you + + + align:start position:0% +the screen at the sensor plane and you +take the vertical projections you don't + + align:start position:0% +take the vertical projections you don't + + + align:start position:0% +take the vertical projections you don't +get any of the red components you only + + align:start position:0% +get any of the red components you only + + + align:start position:0% +get any of the red components you only +get the green and the blue components so + + align:start position:0% +get the green and the blue components so + + + align:start position:0% +get the green and the blue components so +you essentially by occluding the red + + align:start position:0% +you essentially by occluding the red + + + align:start position:0% +you essentially by occluding the red +channel over there or the red + + align:start position:0% +channel over there or the red + + + align:start position:0% +channel over there or the red +red color or the red wavelengths over + + align:start position:0% +red color or the red wavelengths over + + + align:start position:0% +red color or the red wavelengths over +there you remove them from the light + + align:start position:0% +there you remove them from the light + + + align:start position:0% +there you remove them from the light +field that gets projected on the sensor + + align:start position:0% +field that gets projected on the sensor + + + align:start position:0% +field that gets projected on the sensor +and you only get what looks like cyan + + align:start position:0% +and you only get what looks like cyan + + + align:start position:0% +and you only get what looks like cyan +it's just green plus blue + + align:start position:0% +it's just green plus blue + + + align:start position:0% +it's just green plus blue +if you were to do that to the green + + align:start position:0% +if you were to do that to the green + + + align:start position:0% +if you were to do that to the green +channel you if you just occlude that you + + align:start position:0% +channel you if you just occlude that you + + + align:start position:0% +channel you if you just occlude that you +have a big zero over here and you only + + align:start position:0% +have a big zero over here and you only + + + align:start position:0% +have a big zero over here and you only +get this plus this and this plus this + + align:start position:0% +get this plus this and this plus this + + + align:start position:0% +get this plus this and this plus this +and so it looks magenta + + align:start position:0% +and so it looks magenta + + + align:start position:0% +and so it looks magenta +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +so essentially what you can do is place + + align:start position:0% +so essentially what you can do is place + + + align:start position:0% +so essentially what you can do is place +any arbitrary mask you want in this + + align:start position:0% +any arbitrary mask you want in this + + + align:start position:0% +any arbitrary mask you want in this +rainbow plane and that will + + align:start position:0% +rainbow plane and that will + + + align:start position:0% +rainbow plane and that will +influence what colors get sensed by the + + align:start position:0% +influence what colors get sensed by the + + + align:start position:0% +influence what colors get sensed by the +sensor and what colors are not sensed by + + align:start position:0% +sensor and what colors are not sensed by + + + align:start position:0% +sensor and what colors are not sensed by +the sensor + + align:start position:0% +the sensor + + + align:start position:0% +the sensor +so it by placing a mask in the rainbow + + align:start position:0% +so it by placing a mask in the rainbow + + + align:start position:0% +so it by placing a mask in the rainbow +plane it allows you to control + + align:start position:0% +plane it allows you to control + + + align:start position:0% +plane it allows you to control +effectively the spectral sensitivity of + + align:start position:0% +effectively the spectral sensitivity of + + + align:start position:0% +effectively the spectral sensitivity of +of the whole imaging system on the + + align:start position:0% +of the whole imaging system on the + + + align:start position:0% +of the whole imaging system on the +camera by + + align:start position:0% +camera by + + + align:start position:0% +camera by +modulating what trays go through and + + align:start position:0% +modulating what trays go through and + + + align:start position:0% +modulating what trays go through and +what rays get included over there + + align:start position:0% +what rays get included over there + + + align:start position:0% +what rays get included over there +so that's what the whole sort of optical + + align:start position:0% +so that's what the whole sort of optical + + + align:start position:0% +so that's what the whole sort of optical +system looks like we have the lens the + + align:start position:0% +system looks like we have the lens the + + + align:start position:0% +system looks like we have the lens the +pinhole the prism + + align:start position:0% +pinhole the prism + + + align:start position:0% +pinhole the prism +uh another lens that images uh that's + + align:start position:0% +uh another lens that images uh that's + + + align:start position:0% +uh another lens that images uh that's +the rainbow plane and we place a mask + + align:start position:0% +the rainbow plane and we place a mask + + + align:start position:0% +the rainbow plane and we place a mask +over there and then the image sensor + + align:start position:0% +over there and then the image sensor + + + align:start position:0% +over there and then the image sensor +itself so what's the benefit of this + + align:start position:0% +itself so what's the benefit of this + + + align:start position:0% +itself so what's the benefit of this +and what's the disadvantage + + align:start position:0% +and what's the disadvantage + + + align:start position:0% +and what's the disadvantage +compared to the other schemes we have + + align:start position:0% +compared to the other schemes we have + + + align:start position:0% +compared to the other schemes we have +seen before + + align:start position:0% + + + + align:start position:0% + +let's look at the decentralization + + align:start position:0% +let's look at the decentralization + + + align:start position:0% +let's look at the decentralization +well starting with the pinhole that's a + + align:start position:0% +well starting with the pinhole that's a + + + align:start position:0% +well starting with the pinhole that's a +bad idea yeah + + align:start position:0% +bad idea yeah + + + align:start position:0% +bad idea yeah +it's always a bad night very simple when + + align:start position:0% +it's always a bad night very simple when + + + align:start position:0% +it's always a bad night very simple when +you're blocking light it's always a bad + + align:start position:0% +you're blocking light it's always a bad + + + align:start position:0% +you're blocking light it's always a bad +idea + + align:start position:0% +idea + + + align:start position:0% +idea +so what would be does everybody see that + + align:start position:0% +so what would be does everybody see that + + + align:start position:0% +so what would be does everybody see that +there's + + align:start position:0% +there's + + + align:start position:0% +there's +what would happen if + + align:start position:0% +what would happen if + + + align:start position:0% +what would happen if +uh the pinhole was made larger + + align:start position:0% + + + + align:start position:0% + +then you have to deal with focus + + align:start position:0% +then you have to deal with focus + + + align:start position:0% +then you have to deal with focus +problems again yeah no it goes anywhere + + align:start position:0% +problems again yeah no it goes anywhere + + + align:start position:0% +problems again yeah no it goes anywhere +so you'll get blur but what kind of + + align:start position:0% +so you'll get blur but what kind of + + + align:start position:0% +so you'll get blur but what kind of +blood will you get + + align:start position:0% +blood will you get + + + align:start position:0% +blood will you get +between your spectrum pieces exactly + + align:start position:0% +between your spectrum pieces exactly + + + align:start position:0% +between your spectrum pieces exactly +the blur will be the wavelength + + align:start position:0% +the blur will be the wavelength + + + align:start position:0% +the blur will be the wavelength +as opposed to its space + + align:start position:0% +as opposed to its space + + + align:start position:0% +as opposed to its space +because even if you make this + + align:start position:0% +because even if you make this + + + align:start position:0% +because even if you make this +pinhole larger + + align:start position:0% + + + + align:start position:0% + +right conceptually + + align:start position:0% +right conceptually + + + align:start position:0% +right conceptually +um i guess you're going to follow this + + align:start position:0% +um i guess you're going to follow this + + + align:start position:0% +um i guess you're going to follow this +trend + + align:start position:0% +trend + + + align:start position:0% +trend +well you know i'm + + align:start position:0% +well you know i'm + + + align:start position:0% +well you know i'm +that's it so but just to get you + + align:start position:0% +that's it so but just to get you + + + align:start position:0% +that's it so but just to get you +thinking + + align:start position:0% +thinking + + + align:start position:0% +thinking +if you if you increase that + + align:start position:0% +if you if you increase that + + + align:start position:0% +if you if you increase that +pinhole + + align:start position:0% +pinhole + + + align:start position:0% +pinhole +you will still get an image at the end + + align:start position:0% +you will still get an image at the end + + + align:start position:0% +you will still get an image at the end +that looks sharp + + align:start position:0% + + + + align:start position:0% + +just like an ordinary image because we + + align:start position:0% +just like an ordinary image because we + + + align:start position:0% +just like an ordinary image because we +created two images the the prism plane + + align:start position:0% +created two images the the prism plane + + + align:start position:0% +created two images the the prism plane +is basically some kind of a virtual + + align:start position:0% +is basically some kind of a virtual + + + align:start position:0% +is basically some kind of a virtual +image + + align:start position:0% +image + + + align:start position:0% +image +we formed an image on that and + + align:start position:0% +we formed an image on that and + + + align:start position:0% +we formed an image on that and +the image of that is being formed on the + + align:start position:0% +the image of that is being formed on the + + + align:start position:0% +the image of that is being formed on the +sensor so there's no problem in terms of + + align:start position:0% +sensor so there's no problem in terms of + + + align:start position:0% +sensor so there's no problem in terms of +the focus blur + + align:start position:0% +the focus blur + + + align:start position:0% +the focus blur +but the ability to control specific + + align:start position:0% +but the ability to control specific + + + align:start position:0% +but the ability to control specific +wavelengths + + align:start position:0% +wavelengths + + + align:start position:0% +wavelengths +has now decreased so there's a blur in + + align:start position:0% +has now decreased so there's a blur in + + + align:start position:0% +has now decreased so there's a blur in +terms of + + align:start position:0% +terms of + + + align:start position:0% +terms of +wavelengths spectral copies escaping or + + align:start position:0% +wavelengths spectral copies escaping or + + + align:start position:0% +wavelengths spectral copies escaping or +saying + + align:start position:0% +saying + + + align:start position:0% +saying +so what if we put some kind of like + + align:start position:0% +so what if we put some kind of like + + + align:start position:0% +so what if we put some kind of like +pattern to let in more light but then we + + align:start position:0% +pattern to let in more light but then we + + + align:start position:0% +pattern to let in more light but then we +can + + align:start position:0% +can + + + align:start position:0% +can +dig them all out later so i'm going to + + align:start position:0% +dig them all out later so i'm going to + + + align:start position:0% +dig them all out later so i'm going to +record a picture or something + + align:start position:0% +record a picture or something + + + align:start position:0% +record a picture or something +or mask or anything very good very good + + align:start position:0% +or mask or anything very good very good + + + align:start position:0% +or mask or anything very good very good +thing + + align:start position:0% +thing + + + align:start position:0% +thing +we haven't covered aperture yet so + + align:start position:0% +we haven't covered aperture yet so + + + align:start position:0% +we haven't covered aperture yet so +okay i quickly talk about it in the end + + align:start position:0% +okay i quickly talk about it in the end + + + align:start position:0% +okay i quickly talk about it in the end +but yeah you're right you could do + + align:start position:0% +but yeah you're right you could do + + + align:start position:0% +but yeah you're right you could do +something of that sort to to deconvolve + + align:start position:0% +something of that sort to to deconvolve + + + align:start position:0% +something of that sort to to deconvolve +the effects of + + align:start position:0% +the effects of + + + align:start position:0% +the effects of +the + + align:start position:0% +the + + + align:start position:0% +the +blur arising from this but it turns out + + align:start position:0% +blur arising from this but it turns out + + + align:start position:0% +blur arising from this but it turns out +that this is sort of a different kind of + + align:start position:0% +that this is sort of a different kind of + + + align:start position:0% +that this is sort of a different kind of +a trade-off that you + + align:start position:0% +a trade-off that you + + + align:start position:0% +a trade-off that you +from what we saw earlier like where we + + align:start position:0% +from what we saw earlier like where we + + + align:start position:0% +from what we saw earlier like where we +were doing the scanning in time when + + align:start position:0% +were doing the scanning in time when + + + align:start position:0% +were doing the scanning in time when +you're scanning in time it's almost like + + align:start position:0% +you're scanning in time it's almost like + + + align:start position:0% +you're scanning in time it's almost like +you have a pinhole in time and then if + + align:start position:0% +you have a pinhole in time and then if + + + align:start position:0% +you have a pinhole in time and then if +you have seen motion then you would have + + align:start position:0% +you have seen motion then you would have + + + align:start position:0% +you have seen motion then you would have +blur you to that in this case you have a + + align:start position:0% +blur you to that in this case you have a + + + align:start position:0% +blur you to that in this case you have a +pinhole in space so you're + + align:start position:0% +pinhole in space so you're + + + align:start position:0% +pinhole in space so you're +you're getting all of this in one shot + + align:start position:0% +you're getting all of this in one shot + + + align:start position:0% +you're getting all of this in one shot +but you you're throwing away light over + + align:start position:0% +but you you're throwing away light over + + + align:start position:0% +but you you're throwing away light over +there because you need this + + align:start position:0% +there because you need this + + + align:start position:0% +there because you need this +you can't have an infinitely a really + + align:start position:0% +you can't have an infinitely a really + + + align:start position:0% +you can't have an infinitely a really +large aperture and you can have some + + align:start position:0% +large aperture and you can have some + + + align:start position:0% +large aperture and you can have some +sort of a for a + + align:start position:0% +sort of a for a + + + align:start position:0% +sort of a for a +reasonably + + align:start position:0% +reasonably + + + align:start position:0% +reasonably +not very tiny aperture you can get + + align:start position:0% +not very tiny aperture you can get + + + align:start position:0% +not very tiny aperture you can get +something like + + align:start position:0% +something like + + + align:start position:0% +something like +six or ten + + align:start position:0% +six or ten + + + align:start position:0% +six or ten +different wavelengths over here which is + + align:start position:0% +different wavelengths over here which is + + + align:start position:0% +different wavelengths over here which is +not great but it's it's something that + + align:start position:0% +not great but it's it's something that + + + align:start position:0% +not great but it's it's something that +it gives you a control over you can + + align:start position:0% +it gives you a control over you can + + + align:start position:0% +it gives you a control over you can +control the wavelength the aperture size + + align:start position:0% +control the wavelength the aperture size + + + align:start position:0% +control the wavelength the aperture size +and control the fidelity of the + + align:start position:0% +and control the fidelity of the + + + align:start position:0% +and control the fidelity of the +wavelengths that you're going to get + + align:start position:0% +wavelengths that you're going to get + + + align:start position:0% +wavelengths that you're going to get +here + + align:start position:0% + + + + align:start position:0% + +so that's sort of the setup that we + + align:start position:0% +so that's sort of the setup that we + + + align:start position:0% +so that's sort of the setup that we +built you have the image sensor over + + align:start position:0% +built you have the image sensor over + + + align:start position:0% +built you have the image sensor over +here which is nothing but a standard + + align:start position:0% +here which is nothing but a standard + + + align:start position:0% +here which is nothing but a standard +camera this is the + + align:start position:0% +camera this is the + + + align:start position:0% +camera this is the +where we place the the mask that + + align:start position:0% +where we place the the mask that + + + align:start position:0% +where we place the the mask that +controls what wavelengths go through and + + align:start position:0% +controls what wavelengths go through and + + + align:start position:0% +controls what wavelengths go through and +what don't and then a bunch of lenses + + align:start position:0% +what don't and then a bunch of lenses + + + align:start position:0% +what don't and then a bunch of lenses +over here and that's the diffraction + + align:start position:0% +over here and that's the diffraction + + + align:start position:0% +over here and that's the diffraction +rating that bends everything so one + + align:start position:0% +rating that bends everything so one + + + align:start position:0% +rating that bends everything so one +thing you should you would notice is + + align:start position:0% +thing you should you would notice is + + + align:start position:0% +thing you should you would notice is +that there is a bend in the optical axis + + align:start position:0% +that there is a bend in the optical axis + + + align:start position:0% +that there is a bend in the optical axis +or something that i didn't show in the + + align:start position:0% +or something that i didn't show in the + + + align:start position:0% +or something that i didn't show in the +optical diagram so far but it's + + align:start position:0% +optical diagram so far but it's + + + align:start position:0% +optical diagram so far but it's +uh again something you have to take care + + align:start position:0% +uh again something you have to take care + + + align:start position:0% +uh again something you have to take care +of when you if you're actually building + + align:start position:0% +of when you if you're actually building + + + align:start position:0% +of when you if you're actually building +the system + + align:start position:0% + + + + align:start position:0% + +so do you want me to go through all the + + align:start position:0% +so do you want me to go through all the + + + align:start position:0% +so do you want me to go through all the +examples or i mean yeah okay so uh this + + align:start position:0% +examples or i mean yeah okay so uh this + + + align:start position:0% +examples or i mean yeah okay so uh this +is a simple test uh setup that we built + + align:start position:0% +is a simple test uh setup that we built + + + align:start position:0% +is a simple test uh setup that we built +and the idea was we had a spectral + + align:start position:0% +and the idea was we had a spectral + + + align:start position:0% +and the idea was we had a spectral +rainbow generator so we have this + + align:start position:0% +rainbow generator so we have this + + + align:start position:0% +rainbow generator so we have this +rainbow which is going from red to blue + + align:start position:0% +rainbow which is going from red to blue + + + align:start position:0% +rainbow which is going from red to blue +it's kind of like that and then we are + + align:start position:0% +it's kind of like that and then we are + + + align:start position:0% +it's kind of like that and then we are +imaging this with our this agile + + align:start position:0% +imaging this with our this agile + + + align:start position:0% +imaging this with our this agile +spectrum camera + + align:start position:0% +spectrum camera + + + align:start position:0% +spectrum camera +now notice that the color that you see + + align:start position:0% +now notice that the color that you see + + + align:start position:0% +now notice that the color that you see +here is because of the color of the + + align:start position:0% +here is because of the color of the + + + align:start position:0% +here is because of the color of the +of the bear sensor on the camera and + + align:start position:0% +of the bear sensor on the camera and + + + align:start position:0% +of the bear sensor on the camera and +it's really + + align:start position:0% +it's really + + + align:start position:0% +it's really +if you were to use a monochrome sensor + + align:start position:0% +if you were to use a monochrome sensor + + + align:start position:0% +if you were to use a monochrome sensor +it would be all gray and just everything + + align:start position:0% +it would be all gray and just everything + + + align:start position:0% +it would be all gray and just everything +in the with equal intensity + + align:start position:0% +in the with equal intensity + + + align:start position:0% +in the with equal intensity +so first when we block off a certain + + align:start position:0% +so first when we block off a certain + + + align:start position:0% +so first when we block off a certain +wavelength so let's say over six about + + align:start position:0% +wavelength so let's say over six about + + + align:start position:0% +wavelength so let's say over six about +600 620 nanometers over here you see a + + align:start position:0% +600 620 nanometers over here you see a + + + align:start position:0% +600 620 nanometers over here you see a +corresponding gap in the image that's + + align:start position:0% +corresponding gap in the image that's + + + align:start position:0% +corresponding gap in the image that's +captured by the camera and + + align:start position:0% + + + + align:start position:0% + +it sort of gives you an intuition that + + align:start position:0% +it sort of gives you an intuition that + + + align:start position:0% +it sort of gives you an intuition that +it is blocking off in the right range + + align:start position:0% +it is blocking off in the right range + + + align:start position:0% +it is blocking off in the right range +and the pair + + align:start position:0% +and the pair + + + align:start position:0% +and the pair +filter actually helps you see that here + + align:start position:0% +filter actually helps you see that here + + + align:start position:0% +filter actually helps you see that here +and if you put some other arbitrary mass + + align:start position:0% +and if you put some other arbitrary mass + + + align:start position:0% +and if you put some other arbitrary mass +that's actually blocking off in two + + align:start position:0% +that's actually blocking off in two + + + align:start position:0% +that's actually blocking off in two +regions you can you get a similar + + align:start position:0% +regions you can you get a similar + + + align:start position:0% +regions you can you get a similar +a corresponding uh image on the + + align:start position:0% +a corresponding uh image on the + + + align:start position:0% +a corresponding uh image on the +on the sensor + + align:start position:0% +on the sensor + + + align:start position:0% +on the sensor +it's it's it looks very different over + + align:start position:0% +it's it's it looks very different over + + + align:start position:0% +it's it's it looks very different over +here it's like more blue over here and + + align:start position:0% +here it's like more blue over here and + + + align:start position:0% +here it's like more blue over here and +so on + + align:start position:0% +so on + + + align:start position:0% +so on +so one of the applications you can do + + align:start position:0% +so one of the applications you can do + + + align:start position:0% +so one of the applications you can do +with this is this this thing that we + + align:start position:0% +with this is this this thing that we + + + align:start position:0% +with this is this this thing that we +worked on was trying to reduce the glare + + align:start position:0% +worked on was trying to reduce the glare + + + align:start position:0% +worked on was trying to reduce the glare +coming out of this led so it's almost + + align:start position:0% +coming out of this led so it's almost + + + align:start position:0% +coming out of this led so it's almost +impossible to see here but you actually + + align:start position:0% +impossible to see here but you actually + + + align:start position:0% +impossible to see here but you actually +have text written in the background + + align:start position:0% +have text written in the background + + + align:start position:0% +have text written in the background +which is + + align:start position:0% +which is + + + align:start position:0% +which is +like some eeg over here in the + + align:start position:0% +like some eeg over here in the + + + align:start position:0% +like some eeg over here in the +background and then you have this bright + + align:start position:0% +background and then you have this bright + + + align:start position:0% +background and then you have this bright +led in the foreground and you want to be + + align:start position:0% +led in the foreground and you want to be + + + align:start position:0% +led in the foreground and you want to be +able to capture both the background and + + align:start position:0% +able to capture both the background and + + + align:start position:0% +able to capture both the background and +the foreground at the same time + + align:start position:0% +the foreground at the same time + + + align:start position:0% +the foreground at the same time +and the background is much much darker + + align:start position:0% +and the background is much much darker + + + align:start position:0% +and the background is much much darker +than the foreground so + + align:start position:0% +than the foreground so + + + align:start position:0% +than the foreground so +if you were to do traditional sort of + + align:start position:0% +if you were to do traditional sort of + + + align:start position:0% +if you were to do traditional sort of +high dynamic range imaging you would if + + align:start position:0% +high dynamic range imaging you would if + + + align:start position:0% +high dynamic range imaging you would if +you increase the exposure much more this + + align:start position:0% +you increase the exposure much more this + + + align:start position:0% +you increase the exposure much more this +halo that's coming out of this led + + align:start position:0% +halo that's coming out of this led + + + align:start position:0% +halo that's coming out of this led +starts to occupy even more parts of the + + align:start position:0% +starts to occupy even more parts of the + + + align:start position:0% +starts to occupy even more parts of the +scene and you can you can't really see + + align:start position:0% +scene and you can you can't really see + + + align:start position:0% +scene and you can you can't really see +the background if you decrease the + + align:start position:0% +the background if you decrease the + + + align:start position:0% +the background if you decrease the +exposure then this hello or this + + align:start position:0% +exposure then this hello or this + + + align:start position:0% +exposure then this hello or this +the the + + align:start position:0% +the the + + + align:start position:0% +the the +this artifact reduces but then the + + align:start position:0% +this artifact reduces but then the + + + align:start position:0% +this artifact reduces but then the +background becomes even darker so what + + align:start position:0% +background becomes even darker so what + + + align:start position:0% +background becomes even darker so what +you really want to do is just + + align:start position:0% +you really want to do is just + + + align:start position:0% +you really want to do is just +occlude this led the effect of the led + + align:start position:0% +occlude this led the effect of the led + + + align:start position:0% +occlude this led the effect of the led +and be able to see the background and + + align:start position:0% +and be able to see the background and + + + align:start position:0% +and be able to see the background and +you can do that by + + align:start position:0% + + + + align:start position:0% + +you still don't see it + + align:start position:0% +you still don't see it + + + align:start position:0% +you still don't see it +you can do that by blocking out these + + align:start position:0% +you can do that by blocking out these + + + align:start position:0% +you can do that by blocking out these +wavelengths corresponding to the led and + + align:start position:0% +wavelengths corresponding to the led and + + + align:start position:0% +wavelengths corresponding to the led and +now the led is much dimmer and actually + + align:start position:0% +now the led is much dimmer and actually + + + align:start position:0% +now the led is much dimmer and actually +if you look at it over here you can + + align:start position:0% +if you look at it over here you can + + + align:start position:0% +if you look at it over here you can +clearly read the background + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +this is strange like now we can see + + align:start position:0% +this is strange like now we can see + + + align:start position:0% +this is strange like now we can see +barely wow this project was horrible + + align:start position:0% +barely wow this project was horrible + + + align:start position:0% +barely wow this project was horrible +yeah yeah + + align:start position:0% +yeah yeah + + + align:start position:0% +yeah yeah +so you can you can see the background a + + align:start position:0% +so you can you can see the background a + + + align:start position:0% +so you can you can see the background a +little bit over there better this way so + + align:start position:0% +little bit over there better this way so + + + align:start position:0% +little bit over there better this way so +that's it's doing high dynamic range but + + align:start position:0% +that's it's doing high dynamic range but + + + align:start position:0% +that's it's doing high dynamic range but +by modulating the spectral profile of + + align:start position:0% +by modulating the spectral profile of + + + align:start position:0% +by modulating the spectral profile of +the scene rather than by cutting off all + + align:start position:0% +the scene rather than by cutting off all + + + align:start position:0% +the scene rather than by cutting off all +wavelengths equally you're cutting off + + align:start position:0% +wavelengths equally you're cutting off + + + align:start position:0% +wavelengths equally you're cutting off +just certain wavelengths that you know + + align:start position:0% +just certain wavelengths that you know + + + align:start position:0% +just certain wavelengths that you know +are in the scene that are causing this + + align:start position:0% +are in the scene that are causing this + + + align:start position:0% +are in the scene that are causing this +this disturbance in the scene + + align:start position:0% + + + + align:start position:0% + +so you can it turns out you can build a + + align:start position:0% +so you can it turns out you can build a + + + align:start position:0% +so you can it turns out you can build a +similar projector also it's this was all + + align:start position:0% +similar projector also it's this was all + + + align:start position:0% +similar projector also it's this was all +for a camera but you can also use this + + align:start position:0% +for a camera but you can also use this + + + align:start position:0% +for a camera but you can also use this +as a projection system so now we have a + + align:start position:0% +as a projection system so now we have a + + + align:start position:0% +as a projection system so now we have a +traditional projector + + align:start position:0% +traditional projector + + + align:start position:0% +traditional projector +diffraction rating this lens and then + + align:start position:0% +diffraction rating this lens and then + + + align:start position:0% +diffraction rating this lens and then +you have this r plane where you have the + + align:start position:0% +you have this r plane where you have the + + + align:start position:0% +you have this r plane where you have the +mask and then the screen is up there + + align:start position:0% +mask and then the screen is up there + + + align:start position:0% +mask and then the screen is up there +and the advantage of doing it with uh + + align:start position:0% +and the advantage of doing it with uh + + + align:start position:0% +and the advantage of doing it with uh +with this sort of a projector system is + + align:start position:0% +with this sort of a projector system is + + + align:start position:0% +with this sort of a projector system is +that you already have a pinhole it turns + + align:start position:0% +that you already have a pinhole it turns + + + align:start position:0% +that you already have a pinhole it turns +out inside the projector and most + + align:start position:0% +out inside the projector and most + + + align:start position:0% +out inside the projector and most +projectors actually have a very long + + align:start position:0% +projectors actually have a very long + + + align:start position:0% +projectors actually have a very long +optical path between the light source + + align:start position:0% +optical path between the light source + + + align:start position:0% +optical path between the light source +and + + align:start position:0% +and + + + align:start position:0% +and +the and the projection lens in order to + + align:start position:0% +the and the projection lens in order to + + + align:start position:0% +the and the projection lens in order to +increase the depth of field that they + + align:start position:0% +increase the depth of field that they + + + align:start position:0% +increase the depth of field that they +get then once they project + + align:start position:0% +get then once they project + + + align:start position:0% +get then once they project +uh the image and + + align:start position:0% +uh the image and + + + align:start position:0% +uh the image and +we we it turns out we didn't even have + + align:start position:0% +we we it turns out we didn't even have + + + align:start position:0% +we we it turns out we didn't even have +to stop the lens or anything of that + + align:start position:0% +to stop the lens or anything of that + + + align:start position:0% +to stop the lens or anything of that +sort and it it it just worked for + + align:start position:0% +sort and it it it just worked for + + + align:start position:0% +sort and it it it just worked for +uh for a projector standard projector + + align:start position:0% +uh for a projector standard projector + + + align:start position:0% +uh for a projector standard projector +without modifying it much + + align:start position:0% + + + + align:start position:0% + +so this is sort of an acute + + align:start position:0% +so this is sort of an acute + + + align:start position:0% +so this is sort of an acute +example where uh + + align:start position:0% +example where uh + + + align:start position:0% +example where uh +the thing i wanted to mention over here + + align:start position:0% +the thing i wanted to mention over here + + + align:start position:0% +the thing i wanted to mention over here +is this concept of metamorph i don't + + align:start position:0% +is this concept of metamorph i don't + + + align:start position:0% +is this concept of metamorph i don't +know if that's been discussed + + align:start position:0% +know if that's been discussed + + + align:start position:0% +know if that's been discussed +but uh metamorph is anything two colors + + align:start position:0% +but uh metamorph is anything two colors + + + align:start position:0% +but uh metamorph is anything two colors +which appear the same to the human eye + + align:start position:0% +which appear the same to the human eye + + + align:start position:0% +which appear the same to the human eye +or a camera uh when viewed under a + + align:start position:0% +or a camera uh when viewed under a + + + align:start position:0% +or a camera uh when viewed under a +certain type of illumination + + align:start position:0% +certain type of illumination + + + align:start position:0% +certain type of illumination +so this is the white illumination of the + + align:start position:0% +so this is the white illumination of the + + + align:start position:0% +so this is the white illumination of the +scene and you probably can't see there's + + align:start position:0% +scene and you probably can't see there's + + + align:start position:0% +scene and you probably can't see there's +like this orange cloth there blue cloth + + align:start position:0% +like this orange cloth there blue cloth + + + align:start position:0% +like this orange cloth there blue cloth +and so on and many of the colors over + + align:start position:0% +and so on and many of the colors over + + + align:start position:0% +and so on and many of the colors over +here + + align:start position:0% +here + + + align:start position:0% +here +you can probably see there + + align:start position:0% +you can probably see there + + + align:start position:0% +you can probably see there +this this it's very hard to distinguish + + align:start position:0% +this this it's very hard to distinguish + + + align:start position:0% +this this it's very hard to distinguish +between this dot and this envelope these + + align:start position:0% +between this dot and this envelope these + + + align:start position:0% +between this dot and this envelope these +are three m uh + + align:start position:0% +are three m uh + + + align:start position:0% +are three m uh +3m stickers right yeah these are all + + align:start position:0% +3m stickers right yeah these are all + + + align:start position:0% +3m stickers right yeah these are all +sticky so these are actually fluorescent + + align:start position:0% +sticky so these are actually fluorescent + + + align:start position:0% +sticky so these are actually fluorescent +these envelopes i think + + align:start position:0% +these envelopes i think + + + align:start position:0% +these envelopes i think +and if you + + align:start position:0% +and if you + + + align:start position:0% +and if you +look on that + + align:start position:0% + + + + align:start position:0% + +so if you look over here you'll see + + align:start position:0% +so if you look over here you'll see + + + align:start position:0% +so if you look over here you'll see +as we project different wavelengths how + + align:start position:0% +as we project different wavelengths how + + + align:start position:0% +as we project different wavelengths how +these colors they appear almost black + + align:start position:0% +these colors they appear almost black + + + align:start position:0% +these colors they appear almost black +and very very similar to one another + + align:start position:0% +and very very similar to one another + + + align:start position:0% +and very very similar to one another +under different illumination and now one + + align:start position:0% +under different illumination and now one + + + align:start position:0% +under different illumination and now one +of them is going to become brighter than + + align:start position:0% +of them is going to become brighter than + + + align:start position:0% +of them is going to become brighter than +the other and you can + + align:start position:0% +the other and you can + + + align:start position:0% +the other and you can +actually see the difference so + + align:start position:0% +actually see the difference so + + + align:start position:0% +actually see the difference so +it's very interesting to see the project + + align:start position:0% +it's very interesting to see the project + + + align:start position:0% +it's very interesting to see the project +progression of how + + align:start position:0% + + + + align:start position:0% + +it gives you an intuition into that + + align:start position:0% +it gives you an intuition into that + + + align:start position:0% +it gives you an intuition into that +there's much more to the wavelength + + align:start position:0% +there's much more to the wavelength + + + align:start position:0% +there's much more to the wavelength +profile than what the human eye simply + + align:start position:0% +profile than what the human eye simply + + + align:start position:0% +profile than what the human eye simply +sees in white light so can you just + + align:start position:0% +sees in white light so can you just + + + align:start position:0% +sees in white light so can you just +explain again uh what happened i mean + + align:start position:0% +explain again uh what happened i mean + + + align:start position:0% +explain again uh what happened i mean +during this animation well this i'm just + + align:start position:0% +during this animation well this i'm just + + + align:start position:0% +during this animation well this i'm just +projecting monochromatic sort of all + + align:start position:0% +projecting monochromatic sort of all + + + align:start position:0% +projecting monochromatic sort of all +very narrow wavelength of light + + align:start position:0% +very narrow wavelength of light + + + align:start position:0% +very narrow wavelength of light +so red green and blue so about 12 or 15 + + align:start position:0% +so red green and blue so about 12 or 15 + + + align:start position:0% +so red green and blue so about 12 or 15 +different wavelengths so it starts with + + align:start position:0% +different wavelengths so it starts with + + + align:start position:0% +different wavelengths so it starts with +very reddish and slightly yellowish then + + align:start position:0% +very reddish and slightly yellowish then + + + align:start position:0% +very reddish and slightly yellowish then +greenish + + align:start position:0% +greenish + + + align:start position:0% +greenish +then magenta and then finally blush + + align:start position:0% +then magenta and then finally blush + + + align:start position:0% +then magenta and then finally blush +not magenta sorry siren + + align:start position:0% +not magenta sorry siren + + + align:start position:0% +not magenta sorry siren +so it just shows you some of the i mean + + align:start position:0% +so it just shows you some of the i mean + + + align:start position:0% +so it just shows you some of the i mean +i think if you look at the background + + align:start position:0% +i think if you look at the background + + + align:start position:0% +i think if you look at the background +this + + align:start position:0% +this + + + align:start position:0% +this +this looks so different from + + align:start position:0% +this looks so different from + + + align:start position:0% +this looks so different from +from this envelope whereas over here + + align:start position:0% +from this envelope whereas over here + + + align:start position:0% +from this envelope whereas over here +it's actually very similar color + + align:start position:0% +it's actually very similar color + + + align:start position:0% +it's actually very similar color +in white + + align:start position:0% +in white + + + align:start position:0% +in white +and and this these uh + + align:start position:0% +and and this these uh + + + align:start position:0% +and and this these uh +these + + align:start position:0% +these + + + align:start position:0% +these +papers are very fluorescent + + align:start position:0% +papers are very fluorescent + + + align:start position:0% +papers are very fluorescent +intentionally so they look very + + align:start position:0% +intentionally so they look very + + + align:start position:0% +intentionally so they look very +beautiful where they're on your tabletop + + align:start position:0% +beautiful where they're on your tabletop + + + align:start position:0% +beautiful where they're on your tabletop +but they're also responding to very + + align:start position:0% +but they're also responding to very + + + align:start position:0% +but they're also responding to very +narrow wavelength of light + + align:start position:0% +narrow wavelength of light + + + align:start position:0% +narrow wavelength of light +so that's why the + + align:start position:0% +so that's why the + + + align:start position:0% +so that's why the +some of the + + align:start position:0% +some of the + + + align:start position:0% +some of the +some of these envelopes become + + align:start position:0% +some of these envelopes become + + + align:start position:0% +some of these envelopes become +completely dark when you eliminate all + + align:start position:0% +completely dark when you eliminate all + + + align:start position:0% +completely dark when you eliminate all +your particular flavor + + align:start position:0% + + + + align:start position:0% + +question yeah could it have enhancement + + align:start position:0% +question yeah could it have enhancement + + + align:start position:0% +question yeah could it have enhancement +for you to just take an image and then + + align:start position:0% +for you to just take an image and then + + + align:start position:0% +for you to just take an image and then +use different channels to generate those + + align:start position:0% +use different channels to generate those + + + align:start position:0% +use different channels to generate those +15 uh images that you generated did you + + align:start position:0% +15 uh images that you generated did you + + + align:start position:0% +15 uh images that you generated did you +have to definitely take them at + + align:start position:0% +have to definitely take them at + + + align:start position:0% +have to definitely take them at +different illuminations or + + align:start position:0% +different illuminations or + + + align:start position:0% +different illuminations or +well if you have a camera that captures + + align:start position:0% +well if you have a camera that captures + + + align:start position:0% +well if you have a camera that captures +all 15 well that is yeah you just have + + align:start position:0% +all 15 well that is yeah you just have + + + align:start position:0% +all 15 well that is yeah you just have +another + + align:start position:0% +another + + + align:start position:0% +another +illumination those are the two things + + align:start position:0% +illumination those are the two things + + + align:start position:0% +illumination those are the two things +you need broadband illumination and a + + align:start position:0% +you need broadband illumination and a + + + align:start position:0% +you need broadband illumination and a +camera that captures + + align:start position:0% +camera that captures + + + align:start position:0% +camera that captures +15 spectrums okay + + align:start position:0% +15 spectrums okay + + + align:start position:0% +15 spectrums okay +if you take only three spectrums then + + align:start position:0% +if you take only three spectrums then + + + align:start position:0% +if you take only three spectrums then +you only have three numbers per pixel + + align:start position:0% +you only have three numbers per pixel + + + align:start position:0% +you only have three numbers per pixel +yeah so there's no way you can recover + + align:start position:0% +yeah so there's no way you can recover + + + align:start position:0% +yeah so there's no way you can recover +with 50. and if you have a camera like + + align:start position:0% +with 50. and if you have a camera like + + + align:start position:0% +with 50. and if you have a camera like +this then a lot of other applications + + align:start position:0% +this then a lot of other applications + + + align:start position:0% +this then a lot of other applications +like you know distinguishing between a + + align:start position:0% +like you know distinguishing between a + + + align:start position:0% +like you know distinguishing between a +fake + + align:start position:0% +fake + + + align:start position:0% +fake +vegetable and real vegetable and the + + align:start position:0% +vegetable and real vegetable and the + + + align:start position:0% +vegetable and real vegetable and the +freshness of skin and looking through + + align:start position:0% +freshness of skin and looking through + + + align:start position:0% +freshness of skin and looking through +fog all those problems not fog maybe but + + align:start position:0% +fog all those problems not fog maybe but + + + align:start position:0% +fog all those problems not fog maybe but +some other problems + + align:start position:0% +some other problems + + + align:start position:0% +some other problems +become manageable + + align:start position:0% +become manageable + + + align:start position:0% +become manageable +and + + align:start position:0% +and + + + align:start position:0% +and +film and even digital photography is + + align:start position:0% +film and even digital photography is + + + align:start position:0% +film and even digital photography is +just trying to mimic human eye three + + align:start position:0% +just trying to mimic human eye three + + + align:start position:0% +just trying to mimic human eye three +colors in fact three fixed colors as + + align:start position:0% +colors in fact three fixed colors as + + + align:start position:0% +colors in fact three fixed colors as +amkita was saying + + align:start position:0% +amkita was saying + + + align:start position:0% +amkita was saying +but what you really want is something + + align:start position:0% +but what you really want is something + + + align:start position:0% +but what you really want is something +like audio equalizer you can + + align:start position:0% +like audio equalizer you can + + + align:start position:0% +like audio equalizer you can +tune any frequency any way of land so + + align:start position:0% +tune any frequency any way of land so + + + align:start position:0% +tune any frequency any way of land so +you can see the world in interesting + + align:start position:0% +you can see the world in interesting + + + align:start position:0% +you can see the world in interesting +ways + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +this is another example of where uh + + align:start position:0% +this is another example of where uh + + + align:start position:0% +this is another example of where uh +these adaptive color primaries would + + align:start position:0% +these adaptive color primaries would + + + align:start position:0% +these adaptive color primaries would +help and + + align:start position:0% +help and + + + align:start position:0% +help and +as i mentioned earlier there is very + + align:start position:0% +as i mentioned earlier there is very + + + align:start position:0% +as i mentioned earlier there is very +little + + align:start position:0% +little + + + align:start position:0% +little +like cyan is one of the hardest colors + + align:start position:0% +like cyan is one of the hardest colors + + + align:start position:0% +like cyan is one of the hardest colors +to project for most projectors because + + align:start position:0% +to project for most projectors because + + + align:start position:0% +to project for most projectors because +you your colors camera is usually over + + align:start position:0% +you your colors camera is usually over + + + align:start position:0% +you your colors camera is usually over +there and there's very little + + align:start position:0% +there and there's very little + + + align:start position:0% +there and there's very little +representation from there and it turns + + align:start position:0% +representation from there and it turns + + + align:start position:0% +representation from there and it turns +out there are like two definitions of + + align:start position:0% +out there are like two definitions of + + + align:start position:0% +out there are like two definitions of +cyan one is like the traditional + + align:start position:0% +cyan one is like the traditional + + + align:start position:0% +cyan one is like the traditional +printing cyan and the other is what's + + align:start position:0% +printing cyan and the other is what's + + + align:start position:0% +printing cyan and the other is what's +called the electronic or electric cyan + + align:start position:0% +called the electronic or electric cyan + + + align:start position:0% +called the electronic or electric cyan +and this this color is so what i'm + + align:start position:0% +and this this color is so what i'm + + + align:start position:0% +and this this color is so what i'm +predicting here is just a ramp between + + align:start position:0% +predicting here is just a ramp between + + + align:start position:0% +predicting here is just a ramp between +blue and green so this is blue here and + + align:start position:0% +blue and green so this is blue here and + + + align:start position:0% +blue and green so this is blue here and +green and colors in between and this is + + align:start position:0% +green and colors in between and this is + + + align:start position:0% +green and colors in between and this is +what the computer thinks of our sign at + + align:start position:0% +what the computer thinks of our sign at + + + align:start position:0% +what the computer thinks of our sign at +the top and bottom and you can see + + align:start position:0% +the top and bottom and you can see + + + align:start position:0% +the top and bottom and you can see +there's clearly a leak over here and + + align:start position:0% +there's clearly a leak over here and + + + align:start position:0% +there's clearly a leak over here and +that's because when you + + align:start position:0% +that's because when you + + + align:start position:0% +that's because when you +along this line is what i'm projecting + + align:start position:0% +along this line is what i'm projecting + + + align:start position:0% +along this line is what i'm projecting +over here this + + align:start position:0% +over here this + + + align:start position:0% +over here this +this line + + align:start position:0% +this line + + + align:start position:0% +this line +and so the sine is nothing but a point + + align:start position:0% +and so the sine is nothing but a point + + + align:start position:0% +and so the sine is nothing but a point +that lies somewhere on this line so you + + align:start position:0% +that lies somewhere on this line so you + + + align:start position:0% +that lies somewhere on this line so you +cannot project a color which is out here + + align:start position:0% +cannot project a color which is out here + + + align:start position:0% +cannot project a color which is out here +using a standard projector or a display + + align:start position:0% +using a standard projector or a display + + + align:start position:0% +using a standard projector or a display +but if you use this sort of + + align:start position:0% +but if you use this sort of + + + align:start position:0% +but if you use this sort of +agile spectrum you can tweak it so that + + align:start position:0% +agile spectrum you can tweak it so that + + + align:start position:0% +agile spectrum you can tweak it so that +your color over here is + + align:start position:0% +your color over here is + + + align:start position:0% +your color over here is +is actually something that's outside + + align:start position:0% +is actually something that's outside + + + align:start position:0% +is actually something that's outside +your uh your color spectrum that the + + align:start position:0% +your uh your color spectrum that the + + + align:start position:0% +your uh your color spectrum that the +projector could have displayed that's + + align:start position:0% +projector could have displayed that's + + + align:start position:0% +projector could have displayed that's +because you're using you're not using + + align:start position:0% +because you're using you're not using + + + align:start position:0% +because you're using you're not using +the filters that the projector was using + + align:start position:0% +the filters that the projector was using + + + align:start position:0% +the filters that the projector was using +but actually displaying something + + align:start position:0% +but actually displaying something + + + align:start position:0% +but actually displaying something +outside it + + align:start position:0% +outside it + + + align:start position:0% +outside it +so some companies also trying to sell + + align:start position:0% +so some companies also trying to sell + + + align:start position:0% +so some companies also trying to sell +you + + align:start position:0% +you + + + align:start position:0% +you +four or six color projectors so they'll + + align:start position:0% +four or six color projectors so they'll + + + align:start position:0% +four or six color projectors so they'll +have this point here + + align:start position:0% +have this point here + + + align:start position:0% +have this point here +maybe another point here another point + + align:start position:0% +maybe another point here another point + + + align:start position:0% +maybe another point here another point +here here here and here so they can + + align:start position:0% +here here here and here so they can + + + align:start position:0% +here here here and here so they can +cover more colors + + align:start position:0% +cover more colors + + + align:start position:0% +cover more colors +than a standard three color projector + + align:start position:0% +than a standard three color projector + + + align:start position:0% +than a standard three color projector +because there is a three color projector + + align:start position:0% +because there is a three color projector + + + align:start position:0% +because there is a three color projector +you just you must pick some three points + + align:start position:0% +you just you must pick some three points + + + align:start position:0% +you just you must pick some three points +and you cannot represent this shape with + + align:start position:0% +and you cannot represent this shape with + + + align:start position:0% +and you cannot represent this shape with +three points + + align:start position:0% +three points + + + align:start position:0% +three points +uh if you start going too close to uh + + align:start position:0% +uh if you start going too close to uh + + + align:start position:0% +uh if you start going too close to uh +over here if you take this part too + + align:start position:0% +over here if you take this part too + + + align:start position:0% +over here if you take this part too +close here + + align:start position:0% +close here + + + align:start position:0% +close here +then as i said earlier it has to be very + + align:start position:0% +then as i said earlier it has to be very + + + align:start position:0% +then as i said earlier it has to be very +pure green + + align:start position:0% +pure green + + + align:start position:0% +pure green +and that's difficult to generate unless + + align:start position:0% +and that's difficult to generate unless + + + align:start position:0% +and that's difficult to generate unless +you have a laser to change + + align:start position:0% +you have a laser to change + + + align:start position:0% +you have a laser to change +so do the laser projectors have a wider + + align:start position:0% +so do the laser projectors have a wider + + + align:start position:0% +so do the laser projectors have a wider +color exactly so the laser projections + + align:start position:0% +color exactly so the laser projections + + + align:start position:0% +color exactly so the laser projections +can go off + + align:start position:0% +can go off + + + align:start position:0% +can go off +they can stay almost on the + + align:start position:0% +they can stay almost on the + + + align:start position:0% +they can stay almost on the +the pure colors so they can go all the + + align:start position:0% +the pure colors so they can go all the + + + align:start position:0% +the pure colors so they can go all the +way here and here and here so they can + + align:start position:0% +way here and here and here so they can + + + align:start position:0% +way here and here and here so they can +cover a larger cabinet + + align:start position:0% +cover a larger cabinet + + + align:start position:0% +cover a larger cabinet +but there are other issues with with + + align:start position:0% +but there are other issues with with + + + align:start position:0% +but there are other issues with with +them so they usually end up with higher + + align:start position:0% +them so they usually end up with higher + + + align:start position:0% +them so they usually end up with higher +contrast but they are less brightness or + + align:start position:0% +contrast but they are less brightness or + + + align:start position:0% +contrast but they are less brightness or +no how do they usually no they have they + + align:start position:0% +no how do they usually no they have they + + + align:start position:0% +no how do they usually no they have they +have good color rendition yeah + + align:start position:0% +have good color rendition yeah + + + align:start position:0% +have good color rendition yeah +um contrast i don't think there's any + + align:start position:0% +um contrast i don't think there's any + + + align:start position:0% +um contrast i don't think there's any +problem + + align:start position:0% + + + + align:start position:0% + +yeah so + + align:start position:0% +yeah so + + + align:start position:0% +yeah so +in general + + align:start position:0% +in general + + + align:start position:0% +in general +a laser projector is going to create + + align:start position:0% +a laser projector is going to create + + + align:start position:0% +a laser projector is going to create +a very nice rendition it's just that + + align:start position:0% +a very nice rendition it's just that + + + align:start position:0% +a very nice rendition it's just that +it's not compatible directly + + align:start position:0% +it's not compatible directly + + + align:start position:0% +it's not compatible directly +with the human vision + + align:start position:0% +with the human vision + + + align:start position:0% +with the human vision +uh so + + align:start position:0% +uh so + + + align:start position:0% +uh so +we're sensitive to the human eye + + align:start position:0% +we're sensitive to the human eye + + + align:start position:0% +we're sensitive to the human eye +for a pure color is not so great + + align:start position:0% +for a pure color is not so great + + + align:start position:0% +for a pure color is not so great +unfortunately + + align:start position:0% +unfortunately + + + align:start position:0% +unfortunately +there are some constraints in the + + align:start position:0% +there are some constraints in the + + + align:start position:0% +there are some constraints in the +wavelength that you can use you can't + + align:start position:0% +wavelength that you can use you can't + + + align:start position:0% +wavelength that you can use you can't +just choose any wavelength they have to + + align:start position:0% +just choose any wavelength they have to + + + align:start position:0% +just choose any wavelength they have to +have a very specific wavelength and then + + align:start position:0% +have a very specific wavelength and then + + + align:start position:0% +have a very specific wavelength and then +they then they use frequency doublers or + + align:start position:0% +they then they use frequency doublers or + + + align:start position:0% +they then they use frequency doublers or +something to get other the other colors + + align:start position:0% +something to get other the other colors + + + align:start position:0% +something to get other the other colors +it's + + align:start position:0% +it's + + + align:start position:0% +it's +just a little more cumbersome to do that + + align:start position:0% +just a little more cumbersome to do that + + + align:start position:0% +just a little more cumbersome to do that +and then there's the + + align:start position:0% +and then there's the + + + align:start position:0% +and then there's the +the issue of power that you need if you + + align:start position:0% +the issue of power that you need if you + + + align:start position:0% +the issue of power that you need if you +want the laser projector to be bright + + align:start position:0% +want the laser projector to be bright + + + align:start position:0% +want the laser projector to be bright +enough you need to have very bright + + align:start position:0% +enough you need to have very bright + + + align:start position:0% +enough you need to have very bright +lasers + + align:start position:0% +lasers + + + align:start position:0% +lasers +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +the amount of optical power that a + + align:start position:0% +the amount of optical power that a + + + align:start position:0% +the amount of optical power that a +projector throws out compared to a + + align:start position:0% +projector throws out compared to a + + + align:start position:0% +projector throws out compared to a +typical laser is quite large so these + + align:start position:0% +typical laser is quite large so these + + + align:start position:0% +typical laser is quite large so these +things actually put out a lot of power + + align:start position:0% +things actually put out a lot of power + + + align:start position:0% +things actually put out a lot of power +compared to your laser pointer for + + align:start position:0% +compared to your laser pointer for + + + align:start position:0% +compared to your laser pointer for +example right so putting a laser bright + + align:start position:0% +example right so putting a laser bright + + + align:start position:0% +example right so putting a laser bright +enough to generate this much light + + align:start position:0% + + + + align:start position:0% + +that is challenging yeah + + align:start position:0% +that is challenging yeah + + + align:start position:0% +that is challenging yeah +yeah so i mean this this looks bright + + align:start position:0% +yeah so i mean this this looks bright + + + align:start position:0% +yeah so i mean this this looks bright +because it's illuminating just one point + + align:start position:0% +because it's illuminating just one point + + + align:start position:0% +because it's illuminating just one point +the laser pointer but if you were to + + align:start position:0% +the laser pointer but if you were to + + + align:start position:0% +the laser pointer but if you were to +actually distribute this over the whole + + align:start position:0% +actually distribute this over the whole + + + align:start position:0% +actually distribute this over the whole +region it would you would barely see + + align:start position:0% +region it would you would barely see + + + align:start position:0% +region it would you would barely see +most of them are scanning + + align:start position:0% +most of them are scanning + + + align:start position:0% +most of them are scanning +single point aren't they aren't most + + align:start position:0% +single point aren't they aren't most + + + align:start position:0% +single point aren't they aren't most +laser yes exactly yeah + + align:start position:0% +laser yes exactly yeah + + + align:start position:0% +laser yes exactly yeah +so it's as though you're actually yeah + + align:start position:0% +so it's as though you're actually yeah + + + align:start position:0% +so it's as though you're actually yeah +distributing this over the space if you + + align:start position:0% +distributing this over the space if you + + + align:start position:0% +distributing this over the space if you +have a million pixels + + align:start position:0% +have a million pixels + + + align:start position:0% +have a million pixels +or one frame every pixel is illuminated + + align:start position:0% +or one frame every pixel is illuminated + + + align:start position:0% +or one frame every pixel is illuminated +only one millionth + + align:start position:0% + + + + align:start position:0% + +you still need a lot of power right + + align:start position:0% +you still need a lot of power right + + + align:start position:0% +you still need a lot of power right +because you're not spending much time in + + align:start position:0% +because you're not spending much time in + + + align:start position:0% +because you're not spending much time in +any one place + + align:start position:0% +any one place + + + align:start position:0% +any one place +but they'll solve this problem + + align:start position:0% +but they'll solve this problem + + + align:start position:0% +but they'll solve this problem +i'm very + + align:start position:0% +i'm very + + + align:start position:0% +i'm very +very hopeful that + + align:start position:0% +very hopeful that + + + align:start position:0% +very hopeful that +solid state races but actually that's + + align:start position:0% +solid state races but actually that's + + + align:start position:0% +solid state races but actually that's +that's a if if we assume for the moment + + align:start position:0% +that's a if if we assume for the moment + + + align:start position:0% +that's a if if we assume for the moment +that that laser pointer is as bright as + + align:start position:0% +that that laser pointer is as bright as + + + align:start position:0% +that that laser pointer is as bright as +the red chunk + + align:start position:0% +the red chunk + + + align:start position:0% +the red chunk +of that slide you were showing us + + align:start position:0% +of that slide you were showing us + + + align:start position:0% +of that slide you were showing us +uh + + align:start position:0% +uh + + + align:start position:0% +uh +yeah like on the previous one + + align:start position:0% +yeah like on the previous one + + + align:start position:0% +yeah like on the previous one +if we it's roughly as bright you know + + align:start position:0% +if we it's roughly as bright you know + + + align:start position:0% +if we it's roughly as bright you know +same ballpark + + align:start position:0% +same ballpark + + + align:start position:0% +same ballpark +but + + align:start position:0% +but + + + align:start position:0% +but +that's uh roughly a megapixel + + align:start position:0% +that's uh roughly a megapixel + + + align:start position:0% +that's uh roughly a megapixel +image + + align:start position:0% +image + + + align:start position:0% +image +a million times 400 million times more + + align:start position:0% +a million times 400 million times more + + + align:start position:0% +a million times 400 million times more +power yeah + + align:start position:0% +power yeah + + + align:start position:0% +power yeah +which is true this is about one + + align:start position:0% +which is true this is about one + + + align:start position:0% +which is true this is about one +milliwatt and the projector is 250 watt + + align:start position:0% + + + + align:start position:0% + +so it's 250 million times more + + align:start position:0% +so it's 250 million times more + + + align:start position:0% +so it's 250 million times more +than the bulb right compared to this + + align:start position:0% +than the bulb right compared to this + + + align:start position:0% +than the bulb right compared to this +laser + + align:start position:0% + + + + align:start position:0% + +i think laser projectors work great if + + align:start position:0% +i think laser projectors work great if + + + align:start position:0% +i think laser projectors work great if +you are in this room where it's not too + + align:start position:0% +you are in this room where it's not too + + + align:start position:0% +you are in this room where it's not too +bright and you have the projector here + + align:start position:0% +bright and you have the projector here + + + align:start position:0% +bright and you have the projector here +to recommend the same thing it works + + align:start position:0% +to recommend the same thing it works + + + align:start position:0% +to recommend the same thing it works +reasonably well but not if you have the + + align:start position:0% +reasonably well but not if you have the + + + align:start position:0% +reasonably well but not if you have the +lights on you probably won't see + + align:start position:0% +lights on you probably won't see + + + align:start position:0% +lights on you probably won't see +anything + + align:start position:0% + + + + align:start position:0% + +so another thing you can do with this is + + align:start position:0% +so another thing you can do with this is + + + align:start position:0% +so another thing you can do with this is +you don't + + align:start position:0% +you don't + + + align:start position:0% +you don't +since you're not stuck with those three + + align:start position:0% +since you're not stuck with those three + + + align:start position:0% +since you're not stuck with those three +color primaries anymore so this is just + + align:start position:0% +color primaries anymore so this is just + + + align:start position:0% +color primaries anymore so this is just +a scene again it doesn't show up there + + align:start position:0% +a scene again it doesn't show up there + + + align:start position:0% +a scene again it doesn't show up there +as well you have glue over here and you + + align:start position:0% +as well you have glue over here and you + + + align:start position:0% +as well you have glue over here and you +have yellow over here and so + + align:start position:0% +have yellow over here and so + + + align:start position:0% +have yellow over here and so +traditionally you would have a rgb + + align:start position:0% +traditionally you would have a rgb + + + align:start position:0% +traditionally you would have a rgb +um + + align:start position:0% +um + + + align:start position:0% +um +filter where for for yellow you are + + align:start position:0% +filter where for for yellow you are + + + align:start position:0% +filter where for for yellow you are +you're turning it on with when the red + + align:start position:0% +you're turning it on with when the red + + + align:start position:0% +you're turning it on with when the red +and the green color filter is in front + + align:start position:0% +and the green color filter is in front + + + align:start position:0% +and the green color filter is in front +of your uh + + align:start position:0% +of your uh + + + align:start position:0% +of your uh +your projection and for the blue you are + + align:start position:0% +your projection and for the blue you are + + + align:start position:0% +your projection and for the blue you are +turning it on only when it's when the + + align:start position:0% +turning it on only when it's when the + + + align:start position:0% +turning it on only when it's when the +blue + + align:start position:0% +blue + + + align:start position:0% +blue +part of the color wheel is in front + + align:start position:0% +part of the color wheel is in front + + + align:start position:0% +part of the color wheel is in front +but if you know that your scene has just + + align:start position:0% +but if you know that your scene has just + + + align:start position:0% +but if you know that your scene has just +this yellow and blue you can actually + + align:start position:0% +this yellow and blue you can actually + + + align:start position:0% +this yellow and blue you can actually +just project a yellow and + + align:start position:0% +just project a yellow and + + + align:start position:0% +just project a yellow and +you can use a yellow and blue projector + + align:start position:0% +you can use a yellow and blue projector + + + align:start position:0% +you can use a yellow and blue projector +and you don't have to use the same + + align:start position:0% +and you don't have to use the same + + + align:start position:0% +and you don't have to use the same +traditional fixed color primaries and + + align:start position:0% +traditional fixed color primaries and + + + align:start position:0% +traditional fixed color primaries and +this will give you a brighter scene and + + align:start position:0% +this will give you a brighter scene and + + + align:start position:0% +this will give you a brighter scene and +one that has more saturation also + + align:start position:0% + + + + align:start position:0% + +so one other sort of uh cute example is + + align:start position:0% +so one other sort of uh cute example is + + + align:start position:0% +so one other sort of uh cute example is +that of uh + + align:start position:0% +that of uh + + + align:start position:0% +that of uh +color blindness simulation and now know + + align:start position:0% +color blindness simulation and now know + + + align:start position:0% +color blindness simulation and now know +professor manuel has done a lot of + + align:start position:0% +professor manuel has done a lot of + + + align:start position:0% +professor manuel has done a lot of +work also in this area i think + + align:start position:0% +work also in this area i think + + + align:start position:0% +work also in this area i think +and the + + align:start position:0% +and the + + + align:start position:0% +and the +idea over here is so so one of the most + + align:start position:0% +idea over here is so so one of the most + + + align:start position:0% +idea over here is so so one of the most +popular type of color blindness is this + + align:start position:0% +popular type of color blindness is this + + + align:start position:0% +popular type of color blindness is this +difference uh you can't tell the + + align:start position:0% +difference uh you can't tell the + + + align:start position:0% +difference uh you can't tell the +difference between red and green and i + + align:start position:0% +difference between red and green and i + + + align:start position:0% +difference between red and green and i +think it's called uteranov and so when + + align:start position:0% +think it's called uteranov and so when + + + align:start position:0% +think it's called uteranov and so when +you have white light elimination you can + + align:start position:0% +you have white light elimination you can + + + align:start position:0% +you have white light elimination you can +uh i think on the right + + align:start position:0% +uh i think on the right + + + align:start position:0% +uh i think on the right +again it's sorry uh the lower ones are + + align:start position:0% +again it's sorry uh the lower ones are + + + align:start position:0% +again it's sorry uh the lower ones are +the + + align:start position:0% +the + + + align:start position:0% +the +the deuteranope simulation so you cannot + + align:start position:0% +the deuteranope simulation so you cannot + + + align:start position:0% +the deuteranope simulation so you cannot +tell the difference between the rows and + + align:start position:0% +tell the difference between the rows and + + + align:start position:0% +tell the difference between the rows and +the leaves and they'll both appear the + + align:start position:0% +the leaves and they'll both appear the + + + align:start position:0% +the leaves and they'll both appear the +same color + + align:start position:0% +same color + + + align:start position:0% +same color +again it's much easier to see over here + + align:start position:0% +again it's much easier to see over here + + + align:start position:0% +again it's much easier to see over here +but if you actually project a certain + + align:start position:0% +but if you actually project a certain + + + align:start position:0% +but if you actually project a certain +wavelength of light on the object it + + align:start position:0% +wavelength of light on the object it + + + align:start position:0% +wavelength of light on the object it +becomes much easier to tell the + + align:start position:0% +becomes much easier to tell the + + + align:start position:0% +becomes much easier to tell the +difference between these two + + align:start position:0% +difference between these two + + + align:start position:0% +difference between these two +and it you can again clearly see on the + + align:start position:0% +and it you can again clearly see on the + + + align:start position:0% +and it you can again clearly see on the +i don't have much luck here today yeah + + align:start position:0% +i don't have much luck here today yeah + + + align:start position:0% +i don't have much luck here today yeah +you can actually see the difference + + align:start position:0% +you can actually see the difference + + + align:start position:0% +you can actually see the difference +between those two when + + align:start position:0% +between those two when + + + align:start position:0% +between those two when +you have this certain projection so + + align:start position:0% +you have this certain projection so + + + align:start position:0% +you have this certain projection so +conceivably using these kind of + + align:start position:0% +conceivably using these kind of + + + align:start position:0% +conceivably using these kind of +projections or using these kind of + + align:start position:0% +projections or using these kind of + + + align:start position:0% +projections or using these kind of +filters you can + + align:start position:0% +filters you can + + + align:start position:0% +filters you can +you can help solve the problem you can + + align:start position:0% +you can help solve the problem you can + + + align:start position:0% +you can help solve the problem you can +you can + + align:start position:0% +you can + + + align:start position:0% +you can +at least get some help in telling the + + align:start position:0% +at least get some help in telling the + + + align:start position:0% +at least get some help in telling the +difference between colors with color for + + align:start position:0% +difference between colors with color for + + + align:start position:0% +difference between colors with color for +people with color blindness + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +quickly go over some of the limitations + + align:start position:0% +quickly go over some of the limitations + + + align:start position:0% +quickly go over some of the limitations +there's diffraction artifacts because + + align:start position:0% +there's diffraction artifacts because + + + align:start position:0% +there's diffraction artifacts because +you have a pinhole you need a reasonably + + align:start position:0% +you have a pinhole you need a reasonably + + + align:start position:0% +you have a pinhole you need a reasonably +small f number in order to get + + align:start position:0% +small f number in order to get + + + align:start position:0% +small f number in order to get +large number or even some + + align:start position:0% +large number or even some + + + align:start position:0% +large number or even some +different color bands and + + align:start position:0% + + + + align:start position:0% + +that's basically the limitations and uh + + align:start position:0% +that's basically the limitations and uh + + + align:start position:0% +that's basically the limitations and uh +so future work one of + + align:start position:0% +so future work one of + + + align:start position:0% +so future work one of +which uh you just mentioned is actually + + align:start position:0% +which uh you just mentioned is actually + + + align:start position:0% +which uh you just mentioned is actually +using a mask over here and i'll go into + + align:start position:0% +using a mask over here and i'll go into + + + align:start position:0% +using a mask over here and i'll go into +that just a little bit and one sort of + + align:start position:0% +that just a little bit and one sort of + + + align:start position:0% +that just a little bit and one sort of +interesting cute uh application + + align:start position:0% +interesting cute uh application + + + align:start position:0% +interesting cute uh application +there's actually a company which does + + align:start position:0% +there's actually a company which does + + + align:start position:0% +there's actually a company which does +that uh where they use this rgb uh + + align:start position:0% +that uh where they use this rgb uh + + + align:start position:0% +that uh where they use this rgb uh +wavelength multiplexing in order to do + + align:start position:0% +wavelength multiplexing in order to do + + + align:start position:0% +wavelength multiplexing in order to do +red and light + + align:start position:0% +red and light + + + align:start position:0% +red and light +the red and + + align:start position:0% +the red and + + + align:start position:0% +the red and +right eye separation so they project + + align:start position:0% +right eye separation so they project + + + align:start position:0% +right eye separation so they project +using uh + + align:start position:0% +using uh + + + align:start position:0% +using uh +left and right + + align:start position:0% +left and right + + + align:start position:0% +left and right +left and right + + align:start position:0% +left and right + + + align:start position:0% +left and right +and so they use use these projectors + + align:start position:0% +and so they use use these projectors + + + align:start position:0% +and so they use use these projectors +which have uh + + align:start position:0% +which have uh + + + align:start position:0% +which have uh +when you view them with a naked eye both + + align:start position:0% +when you view them with a naked eye both + + + align:start position:0% +when you view them with a naked eye both +this and this appear blue because + + align:start position:0% +this and this appear blue because + + + align:start position:0% +this and this appear blue because +they're both in the blue wavelength but + + align:start position:0% +they're both in the blue wavelength but + + + align:start position:0% +they're both in the blue wavelength but +they're actually + + align:start position:0% +they're actually + + + align:start position:0% +they're actually +different parts of the wavelength that + + align:start position:0% +different parts of the wavelength that + + + align:start position:0% +different parts of the wavelength that +that's being occupied by those two + + align:start position:0% +that's being occupied by those two + + + align:start position:0% +that's being occupied by those two +projections and if you put a color + + align:start position:0% +projections and if you put a color + + + align:start position:0% +projections and if you put a color +filter in front of your eyes a different + + align:start position:0% +filter in front of your eyes a different + + + align:start position:0% +filter in front of your eyes a different +filter for each eye you can have the red + + align:start position:0% +filter for each eye you can have the red + + + align:start position:0% +filter for each eye you can have the red +i only see this part and the right i see + + align:start position:0% +i only see this part and the right i see + + + align:start position:0% +i only see this part and the right i see +only that part so when you view it + + align:start position:0% +only that part so when you view it + + + align:start position:0% +only that part so when you view it +visually it would appear just like a + + align:start position:0% +visually it would appear just like a + + + align:start position:0% +visually it would appear just like a +normal projection but if you put on the + + align:start position:0% +normal projection but if you put on the + + + align:start position:0% +normal projection but if you put on the +eyeglasses you can actually distinguish + + align:start position:0% +eyeglasses you can actually distinguish + + + align:start position:0% +eyeglasses you can actually distinguish +between the two and you can have sort of + + align:start position:0% +between the two and you can have sort of + + + align:start position:0% +between the two and you can have sort of +this multiplexing in uh + + align:start position:0% +this multiplexing in uh + + + align:start position:0% +this multiplexing in uh +in wavelengths rather than in time or in + + align:start position:0% +in wavelengths rather than in time or in + + + align:start position:0% +in wavelengths rather than in time or in +polarization + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +so so far we've talked about what's + + align:start position:0% +so so far we've talked about what's + + + align:start position:0% +so so far we've talked about what's +called the spectral light field but it + + align:start position:0% +called the spectral light field but it + + + align:start position:0% +called the spectral light field but it +turns out you can actually combine the + + align:start position:0% +turns out you can actually combine the + + + align:start position:0% +turns out you can actually combine the +concept of a light field with the + + align:start position:0% +concept of a light field with the + + + align:start position:0% +concept of a light field with the +spectral light field so what we have + + align:start position:0% +spectral light field so what we have + + + align:start position:0% +spectral light field so what we have +here is a traditional right field now + + align:start position:0% +here is a traditional right field now + + + align:start position:0% +here is a traditional right field now +it's x and theta and you've placed a + + align:start position:0% +it's x and theta and you've placed a + + + align:start position:0% +it's x and theta and you've placed a +prism in front of this so what this + + align:start position:0% +prism in front of this so what this + + + align:start position:0% +prism in front of this so what this +prism has done is in a direction that + + align:start position:0% +prism has done is in a direction that + + + align:start position:0% +prism has done is in a direction that +depends on the distance between the x + + align:start position:0% +depends on the distance between the x + + + align:start position:0% +depends on the distance between the x +plane and the prism plane you're + + align:start position:0% +plane and the prism plane you're + + + align:start position:0% +plane and the prism plane you're +actually going out and smearing it and + + align:start position:0% +actually going out and smearing it and + + + align:start position:0% +actually going out and smearing it and +getting all the wavelengths in that + + align:start position:0% +getting all the wavelengths in that + + + align:start position:0% +getting all the wavelengths in that +direction so it gives you + + align:start position:0% +direction so it gives you + + + align:start position:0% +direction so it gives you +uh what looks kind of like that or + + align:start position:0% +uh what looks kind of like that or + + + align:start position:0% +uh what looks kind of like that or +something like that so you have a whole + + align:start position:0% +something like that so you have a whole + + + align:start position:0% +something like that so you have a whole +bunch of overlapping spectral light + + align:start position:0% +bunch of overlapping spectral light + + + align:start position:0% +bunch of overlapping spectral light +fields on a spatial light field or you + + align:start position:0% +fields on a spatial light field or you + + + align:start position:0% +fields on a spatial light field or you +can think of it the other way you have a + + align:start position:0% +can think of it the other way you have a + + + align:start position:0% +can think of it the other way you have a +whole + + align:start position:0% +whole + + + align:start position:0% +whole +bunch of overlapping spatial light + + align:start position:0% +bunch of overlapping spatial light + + + align:start position:0% +bunch of overlapping spatial light +fields of spectral light fields so i + + align:start position:0% +fields of spectral light fields so i + + + align:start position:0% +fields of spectral light fields so i +mean you can either put x + + align:start position:0% +mean you can either put x + + + align:start position:0% +mean you can either put x +theta here and lambda here or you can + + align:start position:0% +theta here and lambda here or you can + + + align:start position:0% +theta here and lambda here or you can +replace it and put lambda here and theta + + align:start position:0% +replace it and put lambda here and theta + + + align:start position:0% +replace it and put lambda here and theta +here and it's really not very different + + align:start position:0% +here and it's really not very different + + + align:start position:0% +here and it's really not very different +but what becomes interesting is the case + + align:start position:0% +but what becomes interesting is the case + + + align:start position:0% +but what becomes interesting is the case +where this plane is diffused in front of + + align:start position:0% +where this plane is diffused in front of + + + align:start position:0% +where this plane is diffused in front of +parallel in which case each of these + + align:start position:0% +parallel in which case each of these + + + align:start position:0% +parallel in which case each of these +rays are exactly the same in density + + align:start position:0% +rays are exactly the same in density + + + align:start position:0% +rays are exactly the same in density +because it's a lamb motion or a diffuse + + align:start position:0% +because it's a lamb motion or a diffuse + + + align:start position:0% +because it's a lamb motion or a diffuse +scene so in this case + + align:start position:0% +scene so in this case + + + align:start position:0% +scene so in this case +what you get uh + + align:start position:0% +what you get uh + + + align:start position:0% +what you get uh +the light feel that you get over here is + + align:start position:0% +the light feel that you get over here is + + + align:start position:0% +the light feel that you get over here is +the special sort of + + align:start position:0% +the special sort of + + + align:start position:0% +the special sort of +like fear that we call a blurred light + + align:start position:0% +like fear that we call a blurred light + + + align:start position:0% +like fear that we call a blurred light +field it's because you have you're + + align:start position:0% +field it's because you have you're + + + align:start position:0% +field it's because you have you're +taking the standard spectral light field + + align:start position:0% +taking the standard spectral light field + + + align:start position:0% +taking the standard spectral light field +and then blurring it in this direction + + align:start position:0% +and then blurring it in this direction + + + align:start position:0% +and then blurring it in this direction +so what you could do is + + align:start position:0% +so what you could do is + + + align:start position:0% +so what you could do is +what + + align:start position:0% +what + + + align:start position:0% +what +kevin was pointing out is use + + align:start position:0% +kevin was pointing out is use + + + align:start position:0% +kevin was pointing out is use +if this blurring is not just a box + + align:start position:0% +if this blurring is not just a box + + + align:start position:0% +if this blurring is not just a box +function but a special coded function + + align:start position:0% +function but a special coded function + + + align:start position:0% +function but a special coded function +you could then invert that and you could + + align:start position:0% +you could then invert that and you could + + + align:start position:0% +you could then invert that and you could +get the full spectral light field out of + + align:start position:0% +get the full spectral light field out of + + + align:start position:0% +get the full spectral light field out of +it without having to use a pinhole + + align:start position:0% +it without having to use a pinhole + + + align:start position:0% +it without having to use a pinhole +so + + align:start position:0% + + + + align:start position:0% + +this is what that design sort of looks + + align:start position:0% +this is what that design sort of looks + + + align:start position:0% +this is what that design sort of looks +like so you can put uh + + align:start position:0% +like so you can put uh + + + align:start position:0% +like so you can put uh +so before i get into that i + + align:start position:0% +so before i get into that i + + + align:start position:0% +so before i get into that i +one of the things i didn't talk about is + + align:start position:0% +one of the things i didn't talk about is + + + align:start position:0% +one of the things i didn't talk about is +so you can by putting a pin hole and + + align:start position:0% +so you can by putting a pin hole and + + + align:start position:0% +so you can by putting a pin hole and +putting a light field camera over here + + align:start position:0% +putting a light field camera over here + + + align:start position:0% +putting a light field camera over here +you can simply by using a trash a + + align:start position:0% +you can simply by using a trash a + + + align:start position:0% +you can simply by using a trash a +standard lightweight camera you can + + align:start position:0% +standard lightweight camera you can + + + align:start position:0% +standard lightweight camera you can +capture a multi-spectral image so you + + align:start position:0% +capture a multi-spectral image so you + + + align:start position:0% +capture a multi-spectral image so you +can build a multi-spectrum image by + + align:start position:0% +can build a multi-spectrum image by + + + align:start position:0% +can build a multi-spectrum image by +taking a light field camera and putting + + align:start position:0% +taking a light field camera and putting + + + align:start position:0% +taking a light field camera and putting +a prism a lens and a pinhole in front of + + align:start position:0% +a prism a lens and a pinhole in front of + + + align:start position:0% +a prism a lens and a pinhole in front of +it so what you're essentially doing here + + align:start position:0% +it so what you're essentially doing here + + + align:start position:0% +it so what you're essentially doing here +is replacing the + + align:start position:0% +is replacing the + + + align:start position:0% +is replacing the +is getting rid of the theta component of + + align:start position:0% +is getting rid of the theta component of + + + align:start position:0% +is getting rid of the theta component of +the light field and replacing it with + + align:start position:0% +the light field and replacing it with + + + align:start position:0% +the light field and replacing it with +the lambda component of the light field + + align:start position:0% +the lambda component of the light field + + + align:start position:0% +the lambda component of the light field +so + + align:start position:0% +so + + + align:start position:0% +so +once again you have this light field and + + align:start position:0% +once again you have this light field and + + + align:start position:0% +once again you have this light field and +now you put electric camera in front of + + align:start position:0% +now you put electric camera in front of + + + align:start position:0% +now you put electric camera in front of +it you can sense that + + align:start position:0% +it you can sense that + + + align:start position:0% +it you can sense that +data + + align:start position:0% +data + + + align:start position:0% +data +and this is sort of + + align:start position:0% +and this is sort of + + + align:start position:0% +and this is sort of +initial results that we had in that + + align:start position:0% +initial results that we had in that + + + align:start position:0% +initial results that we had in that +where each it's basically a micro lens + + align:start position:0% +where each it's basically a micro lens + + + align:start position:0% +where each it's basically a micro lens +area that's placed next to the sensor + + align:start position:0% +area that's placed next to the sensor + + + align:start position:0% +area that's placed next to the sensor +and + + align:start position:0% +and + + + align:start position:0% +and +uh so you can see you still have the + + align:start position:0% +uh so you can see you still have the + + + align:start position:0% +uh so you can see you still have the +bare mosaic so you have this red to blue + + align:start position:0% +bare mosaic so you have this red to blue + + + align:start position:0% +bare mosaic so you have this red to blue +sort of effect with green in between + + align:start position:0% +sort of effect with green in between + + + align:start position:0% +sort of effect with green in between +which is what it's sensing + + align:start position:0% +which is what it's sensing + + + align:start position:0% +which is what it's sensing +but another thing you can do is put + + align:start position:0% +but another thing you can do is put + + + align:start position:0% +but another thing you can do is put +what's called a linearly varied variable + + align:start position:0% +what's called a linearly varied variable + + + align:start position:0% +what's called a linearly varied variable +interference filter so this filter + + align:start position:0% +interference filter so this filter + + + align:start position:0% +interference filter so this filter +allows only red wavelengths to come + + align:start position:0% +allows only red wavelengths to come + + + align:start position:0% +allows only red wavelengths to come +through at one end green in the middle + + align:start position:0% +through at one end green in the middle + + + align:start position:0% +through at one end green in the middle +and blue at the other end and this is a + + align:start position:0% +and blue at the other end and this is a + + + align:start position:0% +and blue at the other end and this is a +very spectacularly pure filter it's + + align:start position:0% +very spectacularly pure filter it's + + + align:start position:0% +very spectacularly pure filter it's +basically built out of + + align:start position:0% +basically built out of + + + align:start position:0% +basically built out of +multiple layers of + + align:start position:0% +multiple layers of + + + align:start position:0% +multiple layers of +of coating and using interference + + align:start position:0% +of coating and using interference + + + align:start position:0% +of coating and using interference +and what this does is that it replaces + + align:start position:0% +and what this does is that it replaces + + + align:start position:0% +and what this does is that it replaces +the theta component of the light field + + align:start position:0% +the theta component of the light field + + + align:start position:0% +the theta component of the light field +with the lambda component of of the + + align:start position:0% +with the lambda component of of the + + + align:start position:0% +with the lambda component of of the +spectral light field and now if you put + + align:start position:0% +spectral light field and now if you put + + + align:start position:0% +spectral light field and now if you put +a lightweight camera in front of it you + + align:start position:0% +a lightweight camera in front of it you + + + align:start position:0% +a lightweight camera in front of it you +can again capture the complete light the + + align:start position:0% +can again capture the complete light the + + + align:start position:0% +can again capture the complete light the +complete multispectral image + + align:start position:0% +complete multispectral image + + + align:start position:0% +complete multispectral image +the tradeoff over here is that any one + + align:start position:0% +the tradeoff over here is that any one + + + align:start position:0% +the tradeoff over here is that any one +point on this filter allows only one + + align:start position:0% +point on this filter allows only one + + + align:start position:0% +point on this filter allows only one +very narrow wavelength to go through so + + align:start position:0% +very narrow wavelength to go through so + + + align:start position:0% +very narrow wavelength to go through so +it's replacing a pinhole in space with a + + align:start position:0% +it's replacing a pinhole in space with a + + + align:start position:0% +it's replacing a pinhole in space with a +pinhole in wavelength + + align:start position:0% +pinhole in wavelength + + + align:start position:0% +pinhole in wavelength +and so again you're going to get very + + align:start position:0% +and so again you're going to get very + + + align:start position:0% +and so again you're going to get very +little light + + align:start position:0% + + + + align:start position:0% + +but what you can also do is place + + align:start position:0% +but what you can also do is place + + + align:start position:0% +but what you can also do is place +instead of that filter you can place one + + align:start position:0% +instead of that filter you can place one + + + align:start position:0% +instead of that filter you can place one +of these uh + + align:start position:0% +of these uh + + + align:start position:0% +of these uh +carefully designed masks which are + + align:start position:0% +carefully designed masks which are + + + align:start position:0% +carefully designed masks which are +similar to the pass we use in the coded + + align:start position:0% +similar to the pass we use in the coded + + + align:start position:0% +similar to the pass we use in the coded +aperture but i guess we haven't talked + + align:start position:0% +aperture but i guess we haven't talked + + + align:start position:0% +aperture but i guess we haven't talked +about that no we haven't so so you can + + align:start position:0% +about that no we haven't so so you can + + + align:start position:0% +about that no we haven't so so you can +you can do this sort of thing and then + + align:start position:0% +you can do this sort of thing and then + + + align:start position:0% +you can do this sort of thing and then +use deconvolution in order to recover + + align:start position:0% +use deconvolution in order to recover + + + align:start position:0% +use deconvolution in order to recover +the multispectral image also + + align:start position:0% + + + + align:start position:0% + +cool um let's take a let's take a short + + align:start position:0% +cool um let's take a let's take a short + + + align:start position:0% +cool um let's take a let's take a short +break and then we can + + align:start position:0% +break and then we can + + + align:start position:0% +break and then we can +okay i just have this tomography stuff + + align:start position:0% +okay i just have this tomography stuff + + + align:start position:0% +okay i just have this tomography stuff +that you said actually yeah we'll do it + + align:start position:0% +that you said actually yeah we'll do it + + + align:start position:0% +that you said actually yeah we'll do it +after a little bit okay + + align:start position:0% +after a little bit okay + + + align:start position:0% +after a little bit okay +cool excellent \ No newline at end of file diff --git a/whjt_N9uYFI.txt b/whjt_N9uYFI.txt new file mode 100644 index 0000000000000000000000000000000000000000..361c2778a7964450d4fcff258ff78610ad446bbf --- /dev/null +++ b/whjt_N9uYFI.txt @@ -0,0 +1,1588 @@ +So my name is Erik Demaine. You should + +call me Erik. Welcome back to 6.046. This +is Lecture 2. And today we are going to essentially + +fill in some of the more mathematical underpinnings +of Lecture 1. So, Lecture 1, we just sort + +of barely got our feet wet with some analysis +of algorithms, insertion sort and mergesort. + +And we needed a couple of tools. We had this +big idea of asymptotics and forgetting about + +constants, just looking at the lead term. +And so, today, we're going to develop asymptotic + +notation so that we know that mathematically. +And we also ended up with a recurrence with + +mergesort, the running time of mergesort, +so we need to see how to solve recurrences. + +And we will do those two things today. Question? +Yes, I will speak louder. Thanks. Good. Even + +though I have a microphone, I am not amplified. +OK, so let's start with asymptotic notation. + +We have seen some basic asymptotic notation. +I am sure you have seen it in other classes + +before, things like big O-notation. And today +we are going to really define this rigorously + +so we know what is true and what is not, what +is valid and what is not. We are going to + +define, and unfortunately today is going to be really mathematical + +and really no algorithms today, which is sort +of an anticlimax. But next lecture we will + +talk about real algorithms and will apply +all the things we learned today to real algorithms. + +This is big O-notation, capital O-notation. +We have f(n)=O[g(n)]. This means that there + +are some suitable constants, c and n_o, such +that f is bounded by cg(n) for all sufficiently + +large n. So, this is pretty intuitive notion. +We have seen it before. We are going to assume + +that f(n) is non-negative here. And I just +want f(n) to be bounded above by g(n). We + +have seen a bunch of examples, but something +like 2n^2=O(n^3) defined. And roughly this + +means if you drop leading constants and low +order terms then this is less than or equal + +to that. So, big O corresponds roughly to +less than or equal to. But this is the formalization. + +Another way to think of it formally, a funny +thing about this notation is it is asymmetric. + +Normally, you think of equality being symmetric. +If A=B then B=A. But it's not true here. We + +do not have n^3 being big O of n^2. We don't +even have big O of n^3 equaling n^2. So, we + +will see exactly what that means in a second. +But before we get there, this is a bit bizarre + +notation and you should always think about +what it really means. Another way to think + +about what it really means is that f(n) is +in some set of functions that are like g. + +You could define big O[g(n)] to be a set of +functions, let's call it f(n), such that there + +exist constants. They are the same definition, +I think, fancy here, c and n_o, such that + +we have the bound f(n) is between zero and +cg(n). It is a bit of a long definition, and + +that is why we use the notation, to avoid +having to write this over and over. You can + +think of instead of n^2 being equal to big +O of n^3, what we really mean is that 2n^2 + +is in the set big O(n^3). When we write equal +sign, we in some sense mean this in the set, + +but we are going to use equal sign. You could +write this. And occasionally you see papers + +that write this, but this is the notation +that we are going to use. That has the consequence + +the equal sign is asymmetric, just like this +operator. We have some nifty ways that we + +actually use big O-notation. And it is using +it as a macro. By the way, we have a lot to + +cover today, so I am going to go relatively +fast. If anything is unclear, just stop, ask + +questions, then I will slow down. Otherwise, +I will take this as all completely obvious + +and I can keep going at full speed. The convention, +this is intuitive, I guess, if you do some + +macro programming or something, but it's a +bit more mathematical. We have defined big + +O-notation and it equals big O of something. +And so we have only defined big O when on + +the equal sign we have big O of some function. +But it is useful to have some general expression + +on the right-hand side that involves big O. +For example, let's say we have f(n) = n^3 + ++ O(n^2). This is attempting to get an error +bound. This is saying f(n) is basically n^3 + +but there are these lower order terms that +are O(n^2). And so this means that there is + +a function, shorthand for a function, h(n) +which is in O(n^2) or equals O(n^2) such that + +f(n) = n^3 + h(n). It is saying that there +are some lower order terms that are bounded + +above by some constant times n^2 for sufficiently +large n, and that is what is here. And then + +f(n) equals, now this is a true equality, +n^3 plus that error term. This is very useful + +here. Essentially, I am expressing what the +lead constant is and then saying well, there + +is other stuff and it's all at most n^2. Saying +that f(n) therefore is also order n^3, but + +that is a bit weaker of a statement. This +is a bit more refined. We won't need to use + +this too often, but it is useful. Sometimes +we will see, like in last class we even had + +a big O inside a summation. So, you can use +them all over the place. The point is they + +represent some function in that set. A bit +less intuitive, and this is more subtle, is + +what it means to have big O on the left-hand +side. It means the same thing, but there is + +some convention what equality means. And this +is why equal sign is asymmetric. You should + +read equals like "is". Is means that everything +over here is something over here. So, there + +is an implicit for all on the left-hand side +and there exists on the right-hand side. This + +is a true statement. Anything that is n^2 ++ O(n) is also O(n^2), but not the other way + +around. So, this is a bit asymmetric. If you +think about it, this is pretty intuitive but + +it is subtle so you should be careful. This +says for any expansion of the macro on the + +left-hand side, which should be f(n), there +is an expansion of the macro on the right-hand + +side such that we get equality. And what this +allows you to do is if you have a chain of + +equal signs relations, a chain of "is"s, then +the very first one is equal to or bounded + +by the very last one. So, you can chain equal +signs the way you normally would. You just + +cannot flip them around. Good. So, that's +big O-notation. Any questions about that? + +So, big O is great for expressing upper bounds. +But we also want to talk about lower bounds. + +For algorithms, we usually care about upper +bounds on their running time. Running times + +at most n^2 is at most n log n up to big O, +but sometimes we need to express functions + +that are at least some quantity. For example, +we will show that sorting requires at least + +n log n time in some model. So, we need some +other notation for that. And the notation + +is big Omega-notation. And it is pretty symmetric. +I will just write out the set definition here. + +And we are going to write f(n)= big Omega[g(n)] +to mean f(n) is at least some constant times + +g(n) -- -- for sufficiently large n. So, I +am basically just reversing the inequality + +relation between f and g, nothing surprising, +just to have it there. A random example, and + +now we will get a little bit more sophisticated, +root n= big Omega(lg n). And you should read + +this that up to constant factors root n is +at least log n for sufficiently large n. So, + +omega sort of corresponds to greater than +or equal to. Let me give you some analogies. + +We have big O, we have big omega, this is +less than or equal to, this is greater than + +or equal to. And I am going to fill in some +more here in a moment. It's nice to have all + +the usual operators we have. Normally we have +strict less than, strict greater than and + +equal sign. And we want those sort of analogs +in the asymptotic world where we ignore constant + +factors and ignore lower order terms. We have, +for example, big Theta[g(n)]. This is a capital + +theta which means you write the horizontal +bar in the middle as opposed to all the way + +through. I didn't invent Greek, so that is +the way it is. Theta means that you are less + +than or equal to and you are greater than +or equal to up to constant factors, so it + +is the inner section of these two sets, big +O and big Omega. That is sort of like equal + +sign but, of course, this is very different. +You have things like n^2 is big Theta of 2(n^2) + +because you ignore constant factors, but all +of these other relations, OK, n^2 + O(n) = Theta(n^2), + +but this does not hold with theta because +square root of n is really asymptotically + +bigger than log n. And some of the other examples +we saw like n^2 versus n^3, those don't hold + +with T. And we have some strict notation which +are the little o-notation and little omega-notation. + +There is no little theta because there is +not notion of strict equality versus unstrict + +equality. Little o is going to correspond +roughly to less than and little omega is going + +to correspond to greater than. This is a notation +you will just have to get used to. And I am + +not going to define it precisely here because +it is almost exactly the same. The difference + +is that instead of saying there exists constant +c and n_o, you have to say for every constant + +c there exists a constant n_o. The relationship +between f and g, this inequality must hold + +for all c instead of just for 1. And so n_o +can now depend on c. You can assume that really + +n is sufficiently large, but this gives you +a strict inequality. No matter what constant + +you put here, in front of g, let's say we +are doing little o, f will be still less than + +c times g for sufficiently large n. We have +some random examples. We are again ignoring + +constants. n^2 is always less than n^3 for +sufficiently large n. And it is a bit subtle + +here. I mean in order to prove something like +this, it will become intuitive after you manipulate + +it a little bit. You have to figure out what +n_o is in terms of c. I think it something + +like 2/c. If we have less than or equal to, +that should be right. As long n is at least + +this big, no matter how small of a c, you +should think of c here as being epsilon now, + +in the usual epsilon and deltas. No matter +how small c gets, still I can bound n^2 in + +terms of n^3, upper bound, but whenever you +have theta you do not have either of these + +relations. For example, Ωn^2 = Theta(n^2) +and it is not little o(n^2) and it not little + +omega(n^2) because it is exactly n^2. You +will get some sense in order relation out + +of this, although there are some messy behaviors +as you will see in your problem set. Any questions + +about asymptotic notation? That is the quick +rundown. Now we are going to use it to solve + +some recurrences. Although we won't use it +that much today, we will use it a lot more + +on Wednesday. OK. We will move onto the second +topic of today, which is solving recurrences. + +You have probably solved some recurrences +before in 6.042 or whatever discrete math + +class you have taken. We are going to do more +and have some techniques here that are particularly + +useful for analyzing recursive algorithms, +and we will see that mostly on Wednesday. + +There are three main methods that we are going +to use here for solving recurrences. The first + +one is the substitution method. There is no +general procedure for solving a recurrence. + +There is no good algorithm for solving recurrences, +unfortunately. We just have a bunch of techniques. + +Some of them work some of the time, and if +you are lucky yours will work for your recurrence, + +but it is sort of like solving an integral. +You have to just know some of them, you have + +to know various methods for solving them. +It is usually easy to check if you have the + +right answer. Just like with integrals, you +just differentiate and say oh, I got the right + +answer. And that is essentially the idea of +substitution method. Substitution method will + +always work, but unfortunately Step 1 is guess +the answer. And you have to guess it correctly. + +That makes it a big difficult. You don't have +to guess it completely. You can usually get + +away with not knowing the constant factors, +which is a good thing because we don't really + +care about the constant factors. You guess +the form. You say oh, it is going to be roughly + +n^2, and so it's some constant times n^2 presumably. +So, you guess that. We are going to figure + +out the constants. You try to verify whether +the recurrence satisfies this bound by induction, + +and that is the key. Substitution uses induction. +And from that you usually get the constants + +for free. You figure out what the constants +have to be in order to make this work. So, + +that is the general idea. You will see a few +examples of this. Actually, the same example + +several times. Unfortunately, this is what +you might call, I don't know. This is an algorithm, + +but it uses an oracle which is knowing the +right answer. But sometimes it is not too + +hard to guess the answer. It depends. If you +look at this recurrence, T(n) = 4T(n/2) + + +n, we should implicitly always have some base +case of T of some constant, usually 1 is a + +constant, so we don't really care about the +base case. For algorithms that is always the + +case. And we want to solve this thing. Does +anyone have a guess to what the solution is? + +Ideally someone who doesn't already know how +to solve this recurrence. OK. How many people + +know how to solve this recurrence? A few, +OK. And, of the rest, any guesses? If you + +look at what is going on here, here you have +T(n/2) and let's ignore this term more or + +less. We have n/2 here. If we double n and +get T(n) then we multiply the value by 4. + +And then there is this additive end, but that +doesn't matter so much. What function do you + +know that when you double the argument the +output goes up by a factor of 4? Sorry? n^2,yeah. + +You should think n^2 and you would be right. +But we won't prove n^2 yet. Let's prove something + +simpler, because it turns out proving that +it is at most n^2 is a bit of a pain. We will + +see that in just a few minutes. But let's +guess that T(n) = O(n^3) first because that + +will be easier to prove by induction. You +sort of see how it is done in the easy case, + +and then we will actually get the right answer, +n^2, later. I need to prove. What I am going + +to do is guess that T(n) is some constant +times n^3 at most, so I will be a little more + +precise. I cannot use the big O-notation in +the substitution method so I have to expand + +it out to use constants. I will show you why +in a little bit, but let me just tell you + +at a high level what is important in not using +big O-notation. Big O-notation is great if + +you have a finite chain of big O relations, +you know, n^2 is big O(n^3) is big O(n^4) + +is big O(n^4) is big O(n^4). That is all true. +And so you get that n^2 is big O(n^4). But + +if you have an infinite chain of those relations +then the first thing is not big O of the last + +thing. You have to be very careful. For example, +this is a total aside on the lecture notes. + +Suppose you want to prove that n = O(1). This +is a great relation. If it were true, every + +algorithm would have constant running time. +This is not true. Not in Wayne's World notation. + +You could "prove this by induction" by saying +well, base case is 1 = O(1). OK, that is true. + +And then the induction step as well, if I +know that n-1, so let's suppose that n-1 = O(1), + +well, that implies that n, which is (n-1) ++1, if this is O(1) and 1 = O(1), the whole + +thing is O(1). And that is true. If you knew +that (n-1) = O(1) and 1 = O(1) then their + +sum is also O(1), but this is a false proof. +You cannot induct over big Os. What is going + +on here is that the constants that are implicit +in here are changing. Here you have some big + +O of 1, here you have some big O of 1. You +are probably doubling the constant in there + +every time you do this relation. If you have +a finite number of doubling of constants, + +no big deal, it is just a constant, two the +power number of doublings. But here you are + +doing n doublings and that is no good. The +constant is now depending on n. So, we are + +avoiding this kind of problem by writing out +the constant. We have to make sure that constant + +doesn't change. Good. Now I have written out +the constant. I should be safe. I am assuming + +it for all k less than n, now I have to prove +it for k equal to n. I am going to take T(n) + +and just expand it. I am going to do the obvious +thing. I have this recurrence how to expand + +T(n). Then it involves T(n/2). And I know +some fact about T(n/2) because n/2 is less + +than n. So, let's expand. T(n) = 4T(n/2) + +n. And now I have an upper bound on this thing + +from the induction hypothesis. This is at +most 4 times c times the argument cubed plus + +n. + +Continuing on here. Let's expand this a little +bit. We have n cubed over 2 cubed. Two cubed + +is 8, so 4 over 8 is a half. So, we have Ωcn^3 ++ n. And what I would like this to be is, + +so at the bottom where I would like to go +is that this is at most cn3. That is what + +I would like to prove to reestablish the induction +hypothesis for n. What I will do, in order + +to see when that is case, is just write this +as what I want, so this is sort of the desired + +value, cn3, minus whatever I don't want. This +is called the residual. Now I have to actually + +figure this out. Let's see. We have cn^3, +but only Ωcn^3 here, so I need to subtract + +off Ωcn^3 to get that lead term correct. +And then I have plus n and there is a minus + +here, so it is minus n. And that is the residual. +In order for this to be at most this, I need + +that the residual is non-negative. This is +if the residual part is greater than or equal + +to zero, which is pretty easy to do because +here I have control over c. I get to pick + +c to be whatever I want. And, as long as c +is at least, oh, I don't know, 2, then this + +is a 1 at least. Then I have n^3 should be +greater than or equal to n. And that is always + +the case. For example, this is true if c is +at least what n is, but let's say n is at + +least 1 just for kicks. So, what we have done +is proved that T(n) is at most some constant + +times n^3. And the constant is like 1. So, +that is an upper bound. It is not a tight + +upper bound. We actually believed that it +is n^2, and it is, but you have to be a little + +careful. This does not mean that the answer +is n^3. It just means that at most n^3 is + +big O(n^3). And this is a proof by induction. +Now, technically I should have put a base + +case in this induction, so there is a little +bit missing. The base case is pretty easy + +because T(1) is some constant, but it will +sort of influence things. If the base case + +T(1) is some constant. And what we need is +that it is at most c times one cubed, which + +is c. And that will be true as long as you +choose c to be sufficiently large. So, this + +is true if c is chosen sufficiently large. +Now, we don't care about constants, but the + +point is just to be a little bit careful. +It is not true that T(n) is at most 1 times + +n^2, even though here all we need is that +c is at least 1. For the base case to work, + +c actually might have to be a hundred or whatever +T(1) is. So, be a little bit careful there. + +It doesn't really affect the answer, usually +it won't because we have very simple base + +cases here. OK, so let's try to prove the +tight bound of O(n^2). I am not going to prove + +an omega bound, but you can prove an omega +n squared bound as well using substitution + +method. I will just be satisfied for now proving +an upper bound of n squared. Let's try to + +prove that T(n), this is the same recurrence, +I want to prove that it is O(n^2). I am going + +to do the same thing. And I will write a bit +faster because this is basically copying. + +Except now, instead of three, I have two. +Then I have T(n) = 4T(n/2) + n. I expand this + +T(n/2). This is at most 4c(n/2)^2 + n. And +now, instead of have 2 cubed, I have 2 squared, + +which is only 4. The fours cancel. I get cn^2 ++ n. And if you prefer to write it as desired + +minus residual, then I have cn^2 - (-n). And +I want this to be non-negative. And it is + +damn hard for minus n to be non-negative. +If n is zero we are happy, but unfortunately + +this is an induction on n. It's got to hold +for all n greater than or equal to 1. This + +is not less than or equal to cn^2. Notice +the temptation is to write that this equals + +O(n^2), which is true for this one step. cn^2 +- (-n), well, these are both order n, or this + +is order n, this is order n squared. Certainly +this thing is O(n^2), that is true, but it + +is not completing the induction. To complete +the induction, you have to prove the induction + +hypothesis for n with this constant c. Here +you are getting a constant c of like c + 1, + +which is not good. This is true but useless. +It does not finish the induction, so you can + +sort of ignore that. This proof doesn't work, +which is kind of annoying because we feel, + +in our heart of hearts, that T(n) = n^2. It +turns out to fix this you need to express + +T(n) in a slightly different form. This is, +again, divine inspiration. And, if you have + +a good connection to some divinity, you are +all set. [LAUGHTER] But it is a little bit + +harder for the rest of us mere mortals. It +turns out, and maybe you could guess this, + +that the idea is we want to strengthen the +induction hypothesis. We assumed this relatively + +weak thing, T(k) is less than or equal to +some constant times k^2. We didn't know what + +the constant was, that is fine, but we assumed +that there were no lower order terms. I want + +to look at lower order terms. Maybe they play +a role. And if you look at this progression + +you say, oh, well, I am getting something +like n^2 and the constants are pretty damn + +tight. I mean the fours are canceling and +the c just is preserved. How am I going to + +get rid of this lower order term plus n? Well, +maybe I could subtract off a linear term in + +here and, if I am lucky, it will cancel with +this one. That is all the intuition we have + +at this point. It turns out it works. We look +at T(n) and this is 4T(n/2) + n as usual. + +Now we expand a slightly messier form. We +have 4[c_1*(n/2)^2 - c_2*(n/2)] + n. This + +part is the same because the fours cancel +again. So, we get c_1*n^2, which is good. + +I mean that is sort of the form we want. Then +we have something times n, so let's figure + +it out. We have a plus 1 times n, so let's +write it 1 minus c_2 over 2 times n. Oops, + +got that wrong. There is four times a two +so, in fact, the two is upstairs. Let me double + +check. Right. OK. Now we can write this as +desired minus residual. And we have to be + +a little careful here because now we have +a stronger induction hypothesis to prove. + +We don't just need it is at most c_1*n^2, +which would be fine here because we could + +choose c_2 to be large, but what we really +need is c_1*n^2 - c_2*n, and then minus some + +other stuff. This is, again, desired minus +residual. And minus residual, let's see, we + +have a minus 1 and we have a minus c_2. That +doesn't look so happy. Plus c_2, thank you, + +because that again looked awfully negative. +It is plus c_2. I am getting my signs, there + +is a minus here and there is one minus here, +so there we go. Again, I want my residual + +to be greater than or equal to zero. And if +I have that I will be all set in making this + +inductive argument. Office hours start this +week, in case you are eager to go. They are + +all held in some room in Building 24, which +is roughly the midpoint between here and Stata, + +I think, for no particular reason. And you +can look at the Web page for details on the + +office hours. Continuing along, when is c_2 +- 1 going to be greater than or equal to zero? + +Well, that is true if c_2 is at least 1, which +is no big deal. Again, we get to choose the + +constants however we want. It only has to +hold for some choice of constants. So, we + +can set c_2 greater than or equal to 1. And +then we are happy. That means this whole thing + +is less than or equal to c_1*n^2 - c_2*n if +c_2 is greater than or equal to 1. It is kind + +of funny here. This finishes the induction, +at least the induction step. We proved now + +that for any value of c_1, and provided c_2 +is at least one. We have to be a little more + +careful that c_1 does actually have to be +sufficiently large. Any particular reason + +why? c_1 better not be negative, indeed. c_1 +has to be positive for this to work, but it + +even has to be larger than positive depending. +Sorry. I have been going so fast, I haven't + +asked you questions. Now you are caught off +guard. Yeah? Because of the base case, exactly. + +So, the base case will have T(1) is c_1 time +1 squared minus c_2, we want to prove that + +it is at most this, and T(1) is some constant +we have assumed. We need to choose c_1 to + +be sufficiently larger than c_2, in fact, +so c_2 has to be at least 1. c_1 may have + +to be at least a hundred more than one if +this is sufficiently large. And sufficiently + +large now means with respect to c_2. You have +to be a little bit careful, but in this case + +it doesn't matter. Any questions about the +substitution method? That was the same example + +three times. In the end, it turned out we +got the right answer. But we sort of had to + +know the answer in order to find it, which +is a bit of a pain. It would certainly be + +nicer to just figure out the answer by some +procedure, and that will be the next two techniques + +we talk about. Sorry? How would you prove +a lower bound? I haven't tried it for this + +recurrence, but you should be able to do exactly +the same form. Argue that T(n) is greater + +than or equal to c_1*n^2 - c_2*n. I didn't +check whether that particular form will work, + +but I think it does. Try it. These other methods +will give you, in some sense, upper and lower + +bounds if you are a little bit careful. But, +to really check things, you pretty much have + +to do the substitution method. And you will +get some practice with that. Usually we only + +care about upper bounds. Proving upper bounds +like this is what we will focus on, but occasionally + +we need lower bounds. It is always nice to +know that you have the right answer by proving + +a matching lower bound. The next method we +will talk about is the recursion-tree method. + +And it is a particular way of adding up a +recurrence, and it is my favorite way. It + +usually just works. That's the great thing +about it. It provides you intuition for free. + +It tells you what the answer is pretty much. +It is slightly nonrigorous, this is a bit + +of a pain, so you have to be really careful +when you apply it. Otherwise, you might get + +the wrong answer. Because it involves dot, +dot, dots, our favorite three characters, + +but dot, dot, dots are always a little bit +nonrigorous so be careful. Technically, what + +you should do is find out what the answer +is with recursion-tree method. Then prove + +that it is actually right with the substitution +method. Usually that is not necessary, but + +you should at least have in your mind that +that is required rigorously. And probably + +the first few recurrences you solve, you should +do it that way. When you really understand + +the recursion-tree method, you can be a little +bit more sloppy if you are really sure you + +have the right answer. Let's do an example. +We saw recursion trees very briefly last time + +with mergesort as the intuition why it was +n log n. And, if you took an example like + +the one we just did with the recursion-tree +method, it is dead simple. Just to make our + +life harder, let's do a more complicated recursion. +Here we imagine we have some algorithm. It + +starts with a problem size n, it recursively +solves a problem of size n/4, it then recursively + +solves a problem of size n/2, and it does +n^2 work on the side without nonrecursive + +work. What is that? I mean that is a bit less +obvious, I would say. What we are going to + +do is draw a picture, and we are just going +to expand out that recursion in tree form + +-- -- +and then just add everything up. We want the + +general picture, and the general principle +in the recursion-tree method is we just draw + +this as a picture. We say well, T(n) equals +the sum of n^2, T(n/4) and T(n/2). This is + +a weird way of writing a sum but why not write +it that way. This is going to be a tree. And + +it is going to be a tree by recursively expanding +each of these two leaves. I start by expanding + +T(n) to this, then I keep expanding, expanding, +expanding everything. Let's go one more step. + +We have this n^2, T(n/4), T(n/2). If we expand +one more time, this is going to be n^2 plus + +two things. The first thing is going to be +(n/4)^2, the second thing is going to be (n/2)^2. + +Plus their recursive branches. We have T(n/16) +and T(n/8). Here my arithmetic shows thin. + +This better be the same, T(n/8), and this +should be T(n/4), I believe. You just keep + +going forever, I mean, until you get down +to the base case where T is a constant. So, + +I am now going to skip some steps and say +dot, dot, dot. This is where you have to be + +careful. We have n^2, (n/4)^2, (n/2)^2. Now +this is easy because I have already done them + +all. (n/16)^2, (n/8)^2, (n/8)^2 again, (n/4)^2 +and et cetera, dot, dot, dot, of various levels + +of recursion here. At the bottom, we are going +to get a bunch of constants. These are the + +leaves. I would like to know how many leaves +there are. One challenge is how many leaves + +in this tree could there be? This is a bit +subtle, unlike mergesort or unlike the previous + +recurrence we solved, the number of leaves +here is a bit funny because we are recursing + +at different speeds. This tree is going to +be much smaller than this tree. It is going + +to have smaller depth because it has already +done down to (n/16). Here it has only gone + +down to (n/4). But how many leaves are there +in this recursion tree? All I need is an upper + +bound, some reasonable upper bound. I can +tell you it is at most T(n^10), but that is + +a bit unreasonable. It should be less than +n, good. Why is it less than n? Exactly. I + +start with a problem of size n. And I recurse +into a problem that n/4 and a problem that + +says n/2. When I get down to one I stop. So, +n/4 + n/2 = æn, which is strictly less than + +n. So, definitely the total number of leaves +has to be at most n. If I start out with n + +sort of stuff and get rid of a quarter of +it and then recurse, it is definitely going + +to be less than n stuff at the bottom. So, +strictly less than n leaves. At this point, + +I have done nothing interesting. And then +the second cool idea in recursion trees is + +you don't just expand this tree and see what +it looks like and then say, well, God, how + +the hell am I going to sum that? You sum it +level by level. That is the only other idea. + +It usually works really, really well. Here +it is a bit complicated and I have to think + +a bit to figure out n^2 is n^2. That is the +first level. Easy. The second level, I have + +to think a lot harder. There are three kinds +of mathematicians, those who can add and those + +who cannot, and I am the latter kind so I +need your help. Can you add these things together? + +It's n^2 over something. Please? (5/16)n^2. +Now I really need your help. I think that + +one I could have done, but this one is a little +bit harder. I will go look at my notes while + +you compute that. Any answers? 73/256. Anyone +else confirm that? It seems a bit high to + +me. 73 does not sound right to me. 64? Closer. +It is actually important that we get this + +right. The 256 is correct. I can tell. Everyone +should know that 16^2 = 256. We are computer + +scientists. 25, good. We have two people saying +25, therefore it is correct by democracy. + +[LAUGHTER] 25 is also what my notes say, and +I computed it at home. (25/256)n^2 is the + +right answer. Now, did anyone notice something +magical about this progression? It squares + +each time, good. And, if we were going to +add these up, you might call it? A geometric + +series, very good. So, it turns out this is +geometric. And we know how to sum geometric + +series, at least you should. We started n^2. +We know that at the bottom, well, this is + +not quite a level, we get something like n, +but we are decreasing geometrically. So, the + +total, I mean the solution to the recurrence +is the sum of all the numbers in this tree. + +If we added it up level by level and then +add up all the levels that is going to give + +us the answer. This is the total computed +level by level. It is just a cute way to compute + +it. It usually gives you nice answers like +geometric answers. We have n^2(1 + 5/16 + + +25/256 + ...). And, if we believe in fate +and we see this three number recurrence, we + +know that we have the right answer. In general, +it is going to be (5/16)k, at least we hope, + +and so on. And it keeps going. It doesn't +go on infinitely, but let's just assume it + +goes on infinitely. That will be an upper +bound that goes on forever. This is all times + +n^2. Now, if you are going to know one thing +about geometric series, you should know that + +1 + Ω + º, if you sum all the powers of +2 you get 2. We are computer scientists. We + +have got to know at least the binary case. +This is like writing 0.1111111 in binary, + +actually, as 1, so this is 2. This is even +smaller. We have 5/16, that is less than a + +half and then we are squaring each time, so +this is even less than 2. If you want, there + +is a nifty formula for solving the general +geometric series, but all we need is that + +it is a constant. This is O(n^2). It is also +O(n^2). It is pretty obvious that it is O(n^2) + +because the top thing is n^2. So, there is +our lower bound of n^2. And we have it within + +a factor of 2, which is pretty good. You actually +get a better factor here. So, that is recursion-tree + +method. It is a little shaky here because +we have these dot, dot, dots, and we just + +believe that it is geometric. It turns out +most of the time it is geometric. No problem + +here. I would definitely check it with the +substitution method because this is not obvious + +to me that it is going to be geometric. In +the cases we will look at in a moment, it + +will be much clearer, so clear that we can +state a theorem that everything is working + +fine. And still time, good. So, that was recursion-trees. +There is one more method we are going to talk + +about, and you could essentially think of +it as an application of the recursion-tree + +method but it is made more precise. And it +is an actual theorem, whereas recursion trees, + +if the dot, dot, dots aren't obvious, you +better check them. The sad part about the + +master method is it is pretty restrictive. +It only applies to a particular family of + +recurrences. It should be T(n) = aT(n/b) + +f(n). Am I going to + +call it f? Yes, I will call it f. In particular, +it will not cover the recurrence I just solved + +because I was recursing on two different problems +of different sizes. Here, every problem you + +recurse on should be of the same size. There +are a subproblems. A way to think of this + +is a recursive algorithm. You have a subproblems. +Each of them is of size n/b, so the total + +costs will be this. Then you are doing f(n) +nonrecursive work. A few constraints. a should + +be at least 1, should have at least 1 recursion. +b should be strictly greater than 1. You better + +make the problem smaller or else it is going +to be infinity. And f should have some nice + +property. f(n) should be asymptotically positive. +How many people know what asymptotically positive + +means? No one. OK, you haven't read the textbook. +That's OK. I haven't read it either, although + +don't tell Charles. And he'd notice. And what +might you think asymptotically positive means? + +That we can do a little bit better. Sorry? +Yes, it means for large enough n, f(n) is + +positive. This means f(n) is greater than +zero for n, at least some n_o, so for some + +constant n_o. Eventually it should be positive. +I mean, we don't care about whether it's negative + +1 for n=1, not a big deal. It won't affect +the answer because we only care about the + +asympotics within. The master method, you +gave it a recurrence of this form, it tells + +you the answer. That is the great thing about +the master method. The annoying thing about + +the master method is that it has three cases. +It is a big long. It takes a little bit longer + +to memorize than all the others because the +others are just ideas. Here we need to actually + +remember a few things. Let me state the theorem. +Well, not quite yet. There is one very simple + +idea, which is we are going to compare this +nonrecursive work f(n) with a very particular + +function n^(log_b(a)). Why n^(log_b(a))? You +will see later. It turns out it is the number + +of leaves in the recursion tree, but that +is foreshadowing. So, it is either less, equal + +or bigger. And here we care about asymptotics. +And we have to be a little bit more precious + +about less, equal or bigger. You might think +well, it means little o, big Theta, or little + +omega. It would be nice if the theorem held +for all of those cases, but it leaves some + +gaps. Let's start with Case 1. Case 1 is when +f is smaller. And not just that it is little + +o, but it is actually quite a bit smaller. +It has got to be polynomially smaller than + +n^(log_b(a)). For some positive epsilon, the +running time should be this n to this constant + +log base b of a minus that epsilon, so it +is really polynomially smaller than n^(log_b(a)). + +We cannot handle the little o case, that's +a little bit too strong. This is saying it + +is really quite a bit smaller. But the answer +then is really simple, T(n) = Theta(n^(log_b(a))). + +Great. That is +Case 1. Case 2 is when f(n) is pretty much + +equal to n^(log_b(a)). And by pretty much +equal I mean up to poly log factors. This + +is log base 2 of n to the power k. You should +know this notation. For example, k could be + +zero. And then they are equal up to constant +factors, for some k greater than or equal + +to zero. Less than will not work, so it is +really important that k is non-negative. It + +should probably be an integer. It doesn't +actually matter whether there is an integer, + +but there it is. It could n^(log_b(a)) times +log n or just times nothing, whatever. Again, + +the solution is easy here, T(n) = Theta(n^(log_b(a))* +lg^(k+1)(n)). Presumably it has to be at least + +times log k. It turns out it is log to the +k plus 1 of n. That is Case 2. We have one + +more case which is slightly more complicated. +We need to assume slightly more for Case 3. + +But Case 3 is roughly when f(n) grows bigger +than n^(log_b(a)). So, it should be capital + +Omega, here is one place where we get to use +omega, (n^(log_b(a)) + epsilon) for some positive + +epsilon. It should grow not just bigger but +polynomially bigger. Here it was growing just + +a log factor bigger, poly log, and here it +is a polynomial factor. In this case, we need + +another assumption about f because we worry +a little bit about how quickly f grows. We + +want to make sure that as you go down the +recursion f gets smaller. It would be kind + +of nice if f gets smaller as you go down, +otherwise you are, again, trying to sum to + +infinity or whatever. I see why this is for +some epsilon prime greater than zero. What + +I would like is that if I just sort of take +the recurrence, this T(n) and just throw in + +fs instead, f(n) should be somehow related +to af(n/b). What I would like is that f(n), + +which is at the top of the recursion tree, +should be bigger than the thing at the next + +level down. The sum of all the values at the +next level down should be bigger by some constant + +factor. Here I have the next level down is +at most some 1 - e, something strictly less + +than 1, some constant strictly less than 1 +times the thing at the top level. I need that + +to make sure things are getting smaller as +I go down. Then T(n) = Theta[f(n)]. And that + +is the theorem. This is the master theorem +or whatever you want to call it. It is not + +named after some guy name Master. It is just +the master of all methods because it is very + +easy to apply. Let's apply it a few times. +It is a bit much to take in all at once. And + +then I will give you a sketch of the proof +to see that it is really not that surprising + +this is true if you look at the recursion-tree. +But first let's just try using it. For example, + +we could take T(n) = 4T(n/2) + n. This is +a, this is b, this is f(n). The first thing + +we should compute is n^(log_b(a)). This I +think even I can do. Log base 2 of 4. Yeah, + +log base 2 I can do. This is n^2. OK, so is +f(n) smaller or bigger than n^2? Well, f(n) + += n. n^2 is clearly bigger by a polynomial +factor. So, we are in Case 1. What is the + +answer? n^2, yeah. It is T(n^(log_b(a))), +which here it is just n^2. Let's do some slight + +variation. I am going to keep a and b the +same and just change f. Let's say T(n) = 4T(n/2) + ++ n^2. This is like drill spelling. n^2 is +asymptotically the same as n^2 even up to + +constants. What is the answer? This is Case +2. It is slightly harder. What is k in this + +example? Zero. The answer is? Survey says? +n^2 log n. Good. And a couple more. T(n) = 4T(n/2) + ++ n^3. What is the answer? n^3. This is Case +3. I know this is pretty boring. At this point + +we are just applying this stupid theorem. +How about n^2/lg n? What is the answer? Good. + +In this case no one should answer. It is a +big tricky. I forget exactly the answer. I + +think it is like n^2 log log n over log n, +no? Oh, no. n^2 log log n, that's right. Yeah. + +But you shouldn't know that, and this doesn't +follow from the master method. This is something + +you would have to solve, probably with the +recursion-tree would be a good way to do this + +one, and you need to know some properties +of logs to know how that goes. But here the + +master method does not apply. And so you have +to use a different method. OK. The last thing + +I want to do is tell you why the master method +is true, and that makes it much more intuitive, + +especially using recursion-trees, why everything +works. This is a sketch of a proof, not the + +full thing. You should read the proof in the +textbook. It is not that much harder than + +what I will show, but it is good for you to +know the formal details. I don't have time + +here to do all of the details. I will just +tell you the salient parts. This is the proof + +sketch or the intuition behind the master +method. What we are going to do is just take + +the recursion-tree for this recurrence and +add up each level and then add up all the + +levels and see what we get. We start with +f(n) at the top after we have expanded one + +level. Then we get a different problems, each +of n/b. And after we expand them it will f(n/b) + +for each one. They are all the same size. +Then we expand all of those and so on, and + +we get another a subproblems from there. We +are going to get like f((n/b)^2). That is + +sort of decreasing geometrically the size, +and so on and so on and so on, until at the + +bottom we get constant size problems. This +is a bit special because this is the base + +case, but we have some other constant at the +bottom. We would like to know how many leaves + +there are, but that is a little bit tricky +at the moment. Let's first compute the height + +of this tree. Let me draw it over here. What +is the height of this tree? I start with a + +problem of size n. I want to get down to a +problem of size 1. How long does that take? + +How many levels? This is probably too easy +for some and not at your fingertips for others. + +Log base b of n, good. The height of this +tree is n^(log_b(a)), because it is just how + +many times I divide by b until I get down +to 1. That is great. Now I should be able + +to compute the number of leaves because I +have branching factor a, I have height h. + +The number of leaves is a^h, a^log_b(n). Let +me expand that a little bit. a^log_b(n), properties + +of logs, we can take the n downstairs and +put the a upstairs, and we get n^(log_b(a)). + +Our good friend n^(log_b(a)). So, that is +why Our good friend n^(log_b(a)) is so important + +in the master method. What we are doing is +comparing f, which is the top level, to n^(log_b(a)), + +which up to theta is the bottom level. Now +the leaves are all at the same level because + +we are decreasing at the same rate in every +branch. If I add up the cost at the bottom + +level, it is Theta(n^(log_b(a))). I add up +the things at the top level it is f(n), not + +terribly exciting. But the next level, this +is a little bit more interesting, is af(n/b), + +which should look familiar if you had the +master method already memorized, it is that. + +So, we know that af(n/b) has decreased by +some constant factor, 1-epsilon prime. We + +have gone down. This is a constant factor +smaller than this. And then you sum up the + +next level. It is going to be like a^2f(n/b^2). +I see that I actually wrote this wrong, the + +parentheses. Sorry about that. It is not (n/b)^2. +It is (n/b^2). So, this sequence, in Case + +3 at least, is decreasing geometrically. If +it is decreasing geometrically up to constant + +factors, it is dominated by the biggest term, +which is f(n). Therefore, in Case 3, we get + +Theta[f(n)]. Let's look at the other cases, +and let me adapt those cases to how much time + +we have left. Wow, lot's of time. Five minutes. +Tons of time. What to do? Let me write that + +down. Case 3, the costs decrease. Now, this +is a place I would argue where the dot, dot, + +dot is pretty obvious. Here, this is damn +simple, it is a^kf(n/b^k). And, in Case 3, + +we assume that the costs decrease geometrically +as we go down the tree. That was sort of backwards + +to start with Case 3. Let's do Case 1, which +is sort of the other intuitively easy case. + +In Case 1, we know that f(n) is polynomially +smaller than this thing. And we are sort of + +changing by this very simple procedure in +the middle. I am going to wave my hands if + +this is where you need a more formal argument. +I claim that this will increase geometrically. + +It has to increase geometrically because this +f(n) is polynomially smaller than this one, + +you are going to get various polynomials in +the middle which interpret geometrically from + +the small one to the big one. Therefore, the +big one dominates because it is, again, geometric + +series. As I said, this is intuition, not +a formal argument. This one was pretty formal + +because we assumed it, but here you need a +bit more argument. They may not increase geometrically + +but they could increase faster, and that is +also fine. So, in Case 3, you are dominated, + +I mean you are always dominated by the biggest +term in a geometric series. Here it happens + +to be f(n) and here you are dominated by n^(log_b(a)) +with a bottom term, oh, Theta. Case 2, here + +it is pretty easy but you need to know some +properties of logs. In Case 2, we assume that + +all of these are basically the same. I mean, +we assume that the top is equal to the bottom. + +And this is changing in this very procedural +way. Therefore, all of the ones in the middle + +have to be pretty much the same. Not quite +because here we don't have the log factor. + +Here we have a log to the k. We have n^(log_b(a)) +times log to the kn. Here we don't have the + +log to the k. So, the logs do disappear here. +It turns out the way they disappear is pretty + +slowly. If you look at the top half of these +terms, they will all have log to the k. The + +bottom half they will start to disappear. +I am giving you some oracle information. If + +you take logs and you don't change the argument +by too much, the logs remain. Maybe halfway + +is too far. The claim is that each level is +roughly the same, especially the upper most + +levels are all asymptotically equal. Roughly +the same. And, therefore, the cost is one + +level, here like f(n) times the number of +levels, h. And h is log base b of n. B is + +a constant so we don't care. This is Theta(lg +n). And, therefore, we get T(n) = (n^(log_b(a)) + +lg^(k+1)(n)) times another log n. So, we get +[f(n)lg n]. That is the very quick sketch. + +Sorry, I am being pretty fuzzy on Cases 1 +and 2. Read the proof because you will have + +to, at some point, manipulate logs in that +way. And that is all. Any questions? Or, you + +are all eager to go. OK. Thanks. See you Wednesday. \ No newline at end of file diff --git a/wr5BT78iYa4.txt b/wr5BT78iYa4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6ef2d6be5e7002ad80c935c5a1557b16f24e4cb8 --- /dev/null +++ b/wr5BT78iYa4.txt @@ -0,0 +1,11843 @@ +align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +transforming data as well as modeling + + align:start position:0% +transforming data as well as modeling + + + align:start position:0% +transforming data as well as modeling +and genomics it's a very broad category + + align:start position:0% +and genomics it's a very broad category + + + align:start position:0% +and genomics it's a very broad category +and i'm sure that in the other lectures + + align:start position:0% +and i'm sure that in the other lectures + + + align:start position:0% +and i'm sure that in the other lectures +the the people who are + + align:start position:0% +the the people who are + + + align:start position:0% +the the people who are +giving them have touched on several + + align:start position:0% +giving them have touched on several + + + align:start position:0% +giving them have touched on several +aspects of these same topics as well + + align:start position:0% +aspects of these same topics as well + + + align:start position:0% +aspects of these same topics as well +um + + align:start position:0% +um + + + align:start position:0% +um +the lecture outline is as follows + + align:start position:0% +the lecture outline is as follows + + + align:start position:0% +the lecture outline is as follows +the the first thing we'll do + + align:start position:0% +the the first thing we'll do + + + align:start position:0% +the the first thing we'll do +is to uh + + align:start position:0% +is to uh + + + align:start position:0% +is to uh +go through two very prototypical study + + align:start position:0% +go through two very prototypical study + + + align:start position:0% +go through two very prototypical study +designs one of which is a two-way + + align:start position:0% +designs one of which is a two-way + + + align:start position:0% +designs one of which is a two-way +comparison which occurs all the time in + + align:start position:0% +comparison which occurs all the time in + + + align:start position:0% +comparison which occurs all the time in +studies the second one is a time series + + align:start position:0% +studies the second one is a time series + + + align:start position:0% +studies the second one is a time series +or a dosage study the whole idea the + + align:start position:0% +or a dosage study the whole idea the + + + align:start position:0% +or a dosage study the whole idea the +idea being that there is a + + align:start position:0% +idea being that there is a + + + align:start position:0% +idea being that there is a +one parameter + + align:start position:0% +one parameter + + + align:start position:0% +one parameter +in the um in the study that moves on + + align:start position:0% +in the um in the study that moves on + + + align:start position:0% +in the um in the study that moves on +progresses and you are making + + align:start position:0% +progresses and you are making + + + align:start position:0% +progresses and you are making +measurements + + align:start position:0% +measurements + + + align:start position:0% +measurements +alongside that one parameter + + align:start position:0% +alongside that one parameter + + + align:start position:0% +alongside that one parameter +and finally we get to the topic of data + + align:start position:0% +and finally we get to the topic of data + + + align:start position:0% +and finally we get to the topic of data +represent representation itself properly + + align:start position:0% +represent representation itself properly + + + align:start position:0% +represent representation itself properly +we'll talk about what it is + + align:start position:0% +we'll talk about what it is + + + align:start position:0% +we'll talk about what it is +what it means to go from a measurement + + align:start position:0% +what it means to go from a measurement + + + align:start position:0% +what it means to go from a measurement +device + + align:start position:0% +device + + + align:start position:0% +device +to the spreadsheet because in order to + + align:start position:0% +to the spreadsheet because in order to + + + align:start position:0% +to the spreadsheet because in order to +do analysis we must somehow end up in + + align:start position:0% +do analysis we must somehow end up in + + + align:start position:0% +do analysis we must somehow end up in +the wall of numbers so how does that + + align:start position:0% +the wall of numbers so how does that + + + align:start position:0% +the wall of numbers so how does that +mapping actually happens we'll touch on + + align:start position:0% +mapping actually happens we'll touch on + + + align:start position:0% +mapping actually happens we'll touch on +it very + + align:start position:0% +it very + + + align:start position:0% +it very +little + + align:start position:0% +little + + + align:start position:0% +little +then we talk about the numbers + + align:start position:0% +then we talk about the numbers + + + align:start position:0% +then we talk about the numbers +themselves do they have a dimensionality + + align:start position:0% +themselves do they have a dimensionality + + + align:start position:0% +themselves do they have a dimensionality +attributed to them are there scales + + align:start position:0% +attributed to them are there scales + + + align:start position:0% +attributed to them are there scales +attributed to them + + align:start position:0% +attributed to them + + + align:start position:0% +attributed to them +these things actually matter because + + align:start position:0% +these things actually matter because + + + align:start position:0% +these things actually matter because +depending on whether or not it's + + align:start position:0% +depending on whether or not it's + + + align:start position:0% +depending on whether or not it's +dimensioned certain fundamental theorems + + align:start position:0% +dimensioned certain fundamental theorems + + + align:start position:0% +dimensioned certain fundamental theorems +of mathematics actually do apply in + + align:start position:0% +of mathematics actually do apply in + + + align:start position:0% +of mathematics actually do apply in +guiding you in on how to formulate say a + + align:start position:0% +guiding you in on how to formulate say a + + + align:start position:0% +guiding you in on how to formulate say a +null hypothesis for your experiment you + + align:start position:0% +null hypothesis for your experiment you + + + align:start position:0% +null hypothesis for your experiment you +know what what + + align:start position:0% +know what what + + + align:start position:0% +know what what +would the outcome be had it been random + + align:start position:0% +would the outcome be had it been random + + + align:start position:0% +would the outcome be had it been random +things like that and then we talked + + align:start position:0% +things like that and then we talked + + + align:start position:0% +things like that and then we talked +about how once you have the data down + + align:start position:0% +about how once you have the data down + + + align:start position:0% +about how once you have the data down +you transform it + + align:start position:0% +you transform it + + + align:start position:0% +you transform it +so as to uncover internal or relational + + align:start position:0% +so as to uncover internal or relational + + + align:start position:0% +so as to uncover internal or relational +structures within the data + + align:start position:0% +structures within the data + + + align:start position:0% +structures within the data +and if we get through to this and we + + align:start position:0% +and if we get through to this and we + + + align:start position:0% +and if we get through to this and we +have time left we will go through + + align:start position:0% +have time left we will go through + + + align:start position:0% +have time left we will go through +background concepts which + + align:start position:0% +background concepts which + + + align:start position:0% +background concepts which +crops up very often when we talk about + + align:start position:0% +crops up very often when we talk about + + + align:start position:0% +crops up very often when we talk about +genomics or microarray analysis namely + + align:start position:0% +genomics or microarray analysis namely + + + align:start position:0% +genomics or microarray analysis namely +things or words like noise + + align:start position:0% +things or words like noise + + + align:start position:0% +things or words like noise +what is a replicate what does it mean to + + align:start position:0% +what is a replicate what does it mean to + + + align:start position:0% +what is a replicate what does it mean to +be reproducible + + align:start position:0% +be reproducible + + + align:start position:0% +be reproducible +do you have to normalize your data and + + align:start position:0% +do you have to normalize your data and + + + align:start position:0% +do you have to normalize your data and +what is the notion of a fault in the + + align:start position:0% +what is the notion of a fault in the + + + align:start position:0% +what is the notion of a fault in the +context of say microarray data i mean a + + align:start position:0% +context of say microarray data i mean a + + + align:start position:0% +context of say microarray data i mean a +full is a very natural measure of change + + align:start position:0% +full is a very natural measure of change + + + align:start position:0% +full is a very natural measure of change +when it comes to pcr but is it that + + align:start position:0% +when it comes to pcr but is it that + + + align:start position:0% +when it comes to pcr but is it that +natural after all when you are dealing + + align:start position:0% +natural after all when you are dealing + + + align:start position:0% +natural after all when you are dealing +with + + align:start position:0% +with + + + align:start position:0% +with +microarray data + + align:start position:0% +microarray data + + + align:start position:0% +microarray data +and finally because by going through + + align:start position:0% +and finally because by going through + + + align:start position:0% +and finally because by going through +some miscellaneous rules of thumb + + align:start position:0% +some miscellaneous rules of thumb + + + align:start position:0% +some miscellaneous rules of thumb +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so um two prototypical study designs the + + align:start position:0% +so um two prototypical study designs the + + + align:start position:0% +so um two prototypical study designs the +first is a two-way comparison you see + + align:start position:0% +first is a two-way comparison you see + + + align:start position:0% +first is a two-way comparison you see +this all the time in fact right um + + align:start position:0% +this all the time in fact right um + + + align:start position:0% +this all the time in fact right um +for instance uh you want to + + align:start position:0% +for instance uh you want to + + + align:start position:0% +for instance uh you want to +find molecular + + align:start position:0% +find molecular + + + align:start position:0% +find molecular +gene protein + + align:start position:0% +gene protein + + + align:start position:0% +gene protein +differences in the white blood cells of + + align:start position:0% +differences in the white blood cells of + + + align:start position:0% +differences in the white blood cells of +type 2 diabetes human patients versus + + align:start position:0% +type 2 diabetes human patients versus + + + align:start position:0% +type 2 diabetes human patients versus +normal human patients + + align:start position:0% +normal human patients + + + align:start position:0% +normal human patients +for instance you have 27 diabetes + + align:start position:0% +for instance you have 27 diabetes + + + align:start position:0% +for instance you have 27 diabetes +patients and 11 normal ones and you + + align:start position:0% +patients and 11 normal ones and you + + + align:start position:0% +patients and 11 normal ones and you +microarrays and actually there's a + + align:start position:0% +microarrays and actually there's a + + + align:start position:0% +microarrays and actually there's a +little typo here should be the word + + align:start position:0% +little typo here should be the word + + + align:start position:0% +little typo here should be the word +micro + + align:start position:0% +micro + + + align:start position:0% +micro +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +these studies are often carried out + + align:start position:0% +these studies are often carried out + + + align:start position:0% +these studies are often carried out +and um + + align:start position:0% +and um + + + align:start position:0% +and um +there are very obvious things to keep in + + align:start position:0% +there are very obvious things to keep in + + + align:start position:0% +there are very obvious things to keep in +mind when you do these studies right + + align:start position:0% +mind when you do these studies right + + + align:start position:0% +mind when you do these studies right +namely + + align:start position:0% +namely + + + align:start position:0% +namely +before you do them you should check for + + align:start position:0% +before you do them you should check for + + + align:start position:0% +before you do them you should check for +stratification + + align:start position:0% +stratification + + + align:start position:0% +stratification +say gender age + + align:start position:0% +say gender age + + + align:start position:0% +say gender age +um and things like that other clinical + + align:start position:0% +um and things like that other clinical + + + align:start position:0% +um and things like that other clinical +parameters that could enter later on and + + align:start position:0% +parameters that could enter later on and + + + align:start position:0% +parameters that could enter later on and +be double your + + align:start position:0% +be double your + + + align:start position:0% +be double your +subsequent analysis + + align:start position:0% +subsequent analysis + + + align:start position:0% +subsequent analysis +now a partial mathematical formulation + + align:start position:0% +now a partial mathematical formulation + + + align:start position:0% +now a partial mathematical formulation +of this problem would be + + align:start position:0% +of this problem would be + + + align:start position:0% +of this problem would be +say if you were going to microarray + + align:start position:0% +say if you were going to microarray + + + align:start position:0% +say if you were going to microarray +every person every patient goes on to a + + align:start position:0% +every person every patient goes on to a + + + align:start position:0% +every person every patient goes on to a +chip + + align:start position:0% +chip + + + align:start position:0% +chip +then the jth patient + + align:start position:0% +then the jth patient + + + align:start position:0% +then the jth patient +j diabetic patient you could + + align:start position:0% +j diabetic patient you could + + + align:start position:0% +j diabetic patient you could +represent by this symbol d sub j and an + + align:start position:0% +represent by this symbol d sub j and an + + + align:start position:0% +represent by this symbol d sub j and an +j + + align:start position:0% +j + + + align:start position:0% +j +normal patient you could reproduce by + + align:start position:0% +normal patient you could reproduce by + + + align:start position:0% +normal patient you could reproduce by +this symbol and this + + align:start position:0% + + + + align:start position:0% + +quantity here is actually a vector or + + align:start position:0% +quantity here is actually a vector or + + + align:start position:0% +quantity here is actually a vector or +matrix right it's + + align:start position:0% +matrix right it's + + + align:start position:0% +matrix right it's +multi-factorial we are measuring say 10 + + align:start position:0% +multi-factorial we are measuring say 10 + + + align:start position:0% +multi-factorial we are measuring say 10 +000 genes or proteins or rna of + + align:start position:0% +000 genes or proteins or rna of + + + align:start position:0% +000 genes or proteins or rna of +one person so it's a + + align:start position:0% +one person so it's a + + + align:start position:0% +one person so it's a +multi-dimensional a quantity + + align:start position:0% + + + + align:start position:0% + +um and + + align:start position:0% +um and + + + align:start position:0% +um and +you go on to do subsequent analysis so + + align:start position:0% +you go on to do subsequent analysis so + + + align:start position:0% +you go on to do subsequent analysis so +this is the first prototypical study + + align:start position:0% +this is the first prototypical study + + + align:start position:0% +this is the first prototypical study +design the second one is + + align:start position:0% +design the second one is + + + align:start position:0% +design the second one is +equally common it has to do with a time + + align:start position:0% +equally common it has to do with a time + + + align:start position:0% +equally common it has to do with a time +series or dosage study for instance you + + align:start position:0% +series or dosage study for instance you + + + align:start position:0% +series or dosage study for instance you +are observing a developing organ and you + + align:start position:0% +are observing a developing organ and you + + + align:start position:0% +are observing a developing organ and you +are essaying that organ + + align:start position:0% +are essaying that organ + + + align:start position:0% +are essaying that organ +for rna or protein at different stages + + align:start position:0% +for rna or protein at different stages + + + align:start position:0% +for rna or protein at different stages +of its um development as it unfolds + + align:start position:0% +of its um development as it unfolds + + + align:start position:0% +of its um development as it unfolds +again there are reality checks that you + + align:start position:0% +again there are reality checks that you + + + align:start position:0% +again there are reality checks that you +should do before you begin such as um + + align:start position:0% +should do before you begin such as um + + + align:start position:0% +should do before you begin such as um +that + + align:start position:0% +that + + + align:start position:0% +that +system which you are um + + align:start position:0% +system which you are um + + + align:start position:0% +system which you are um +essaying how heterogeneous is it is it + + align:start position:0% +essaying how heterogeneous is it is it + + + align:start position:0% +essaying how heterogeneous is it is it +one cell type several cell type how is + + align:start position:0% +one cell type several cell type how is + + + align:start position:0% +one cell type several cell type how is +that going to affect um your + + align:start position:0% +that going to affect um your + + + align:start position:0% +that going to affect um your +interpretation of the signals later on + + align:start position:0% +interpretation of the signals later on + + + align:start position:0% +interpretation of the signals later on +right + + align:start position:0% +right + + + align:start position:0% +right +and again a partial mass formulation of + + align:start position:0% +and again a partial mass formulation of + + + align:start position:0% +and again a partial mass formulation of +this + + align:start position:0% +this + + + align:start position:0% +this +design would be let t sub j represent + + align:start position:0% +design would be let t sub j represent + + + align:start position:0% +design would be let t sub j represent +the chip data of the j developmental + + align:start position:0% +the chip data of the j developmental + + + align:start position:0% +the chip data of the j developmental +stage again it is a vector + + align:start position:0% +stage again it is a vector + + + align:start position:0% +stage again it is a vector +and you know you can get very fancy + + align:start position:0% +and you know you can get very fancy + + + align:start position:0% +and you know you can get very fancy +pictures like this of a of the + + align:start position:0% +pictures like this of a of the + + + align:start position:0% +pictures like this of a of the +expression profile + + align:start position:0% +expression profile + + + align:start position:0% +expression profile +as a function of time of one gene and + + align:start position:0% +as a function of time of one gene and + + + align:start position:0% +as a function of time of one gene and +another gene or rna or protein + + align:start position:0% +another gene or rna or protein + + + align:start position:0% +another gene or rna or protein +now what actually is data representation + + align:start position:0% + + + + align:start position:0% + +there + + align:start position:0% +there + + + align:start position:0% +there +it's a it's a very commonly used term + + align:start position:0% +it's a it's a very commonly used term + + + align:start position:0% +it's a it's a very commonly used term +and i don't think anyone can really + + align:start position:0% +and i don't think anyone can really + + + align:start position:0% +and i don't think anyone can really +agree on what it means actually but + + align:start position:0% +agree on what it means actually but + + + align:start position:0% +agree on what it means actually but +it could go anywhere from a mathematical + + align:start position:0% +it could go anywhere from a mathematical + + + align:start position:0% +it could go anywhere from a mathematical +formulation of a scientific problem + + align:start position:0% +formulation of a scientific problem + + + align:start position:0% +formulation of a scientific problem +okay + + align:start position:0% +okay + + + align:start position:0% +okay +or it could be mapping observations and + + align:start position:0% +or it could be mapping observations and + + + align:start position:0% +or it could be mapping observations and +measurements into the set of symbols + + align:start position:0% +measurements into the set of symbols + + + align:start position:0% +measurements into the set of symbols +well it's not just any other set of + + align:start position:0% +well it's not just any other set of + + + align:start position:0% +well it's not just any other set of +symbols typically there are symbols + + align:start position:0% +symbols typically there are symbols + + + align:start position:0% +symbols typically there are symbols +which you can do an algebra on say + + align:start position:0% +which you can do an algebra on say + + + align:start position:0% +which you can do an algebra on say +numbers integers + + align:start position:0% +numbers integers + + + align:start position:0% +numbers integers +things like that + + align:start position:0% +things like that + + + align:start position:0% +things like that +it's pointless to map it into a set of + + align:start position:0% +it's pointless to map it into a set of + + + align:start position:0% +it's pointless to map it into a set of +symbols where you can't actually do + + align:start position:0% +symbols where you can't actually do + + + align:start position:0% +symbols where you can't actually do +higher order operations on that's that + + align:start position:0% +higher order operations on that's that + + + align:start position:0% +higher order operations on that's that +in the point or if you go on a website + + align:start position:0% +in the point or if you go on a website + + + align:start position:0% +in the point or if you go on a website +and type in data representation the + + align:start position:0% +and type in data representation the + + + align:start position:0% +and type in data representation the +national + + align:start position:0% +national + + + align:start position:0% +national +the governmental agency for + + align:start position:0% +the governmental agency for + + + align:start position:0% +the governmental agency for +atmospheric science gives you this + + align:start position:0% +atmospheric science gives you this + + + align:start position:0% +atmospheric science gives you this +definition here which you can read for + + align:start position:0% +definition here which you can read for + + + align:start position:0% +definition here which you can read for +yourself in this + + align:start position:0% +yourself in this + + + align:start position:0% +yourself in this +slide prints out later + + align:start position:0% +slide prints out later + + + align:start position:0% +slide prints out later +another notion of data representation is + + align:start position:0% +another notion of data representation is + + + align:start position:0% +another notion of data representation is +something to do with database annotation + + align:start position:0% +something to do with database annotation + + + align:start position:0% +something to do with database annotation +and standards you've heard of miami + + align:start position:0% +and standards you've heard of miami + + + align:start position:0% +and standards you've heard of miami +presumably in one of the lectures before + + align:start position:0% +presumably in one of the lectures before + + + align:start position:0% +presumably in one of the lectures before +or to come + + align:start position:0% +or to come + + + align:start position:0% +or to come +i'm not going to be talking about that + + align:start position:0% +i'm not going to be talking about that + + + align:start position:0% +i'm not going to be talking about that +at all um + + align:start position:0% +at all um + + + align:start position:0% +at all um +and thirdly + + align:start position:0% +and thirdly + + + align:start position:0% +and thirdly +it could be multimedia how you present + + align:start position:0% +it could be multimedia how you present + + + align:start position:0% +it could be multimedia how you present +your data graphically in charts plots + + align:start position:0% +your data graphically in charts plots + + + align:start position:0% +your data graphically in charts plots +etc things like that + + align:start position:0% +etc things like that + + + align:start position:0% +etc things like that +what i shall be actually concentrating + + align:start position:0% +what i shall be actually concentrating + + + align:start position:0% +what i shall be actually concentrating +on is actually the first two points + + align:start position:0% +on is actually the first two points + + + align:start position:0% +on is actually the first two points +you know it could it is arguable that + + align:start position:0% +you know it could it is arguable that + + + align:start position:0% +you know it could it is arguable that +these two points actually have to do + + align:start position:0% +these two points actually have to do + + + align:start position:0% +these two points actually have to do +with data representation if anything the + + align:start position:0% +with data representation if anything the + + + align:start position:0% +with data representation if anything the +second point certainly does mapping + + align:start position:0% +second point certainly does mapping + + + align:start position:0% +second point certainly does mapping +observations into + + align:start position:0% +observations into + + + align:start position:0% +observations into +a set of symbols + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +so you make an observation and a device + + align:start position:0% +so you make an observation and a device + + + align:start position:0% +so you make an observation and a device +takes a picture of it + + align:start position:0% +takes a picture of it + + + align:start position:0% +takes a picture of it +but eventually it has to get translated + + align:start position:0% +but eventually it has to get translated + + + align:start position:0% +but eventually it has to get translated +into the set of symbols so the the it's + + align:start position:0% +into the set of symbols so the the it's + + + align:start position:0% +into the set of symbols so the the it's +a very + + align:start position:0% +a very + + + align:start position:0% +a very +um + + align:start position:0% +um + + + align:start position:0% +um +obvious thing that one has to actually + + align:start position:0% +obvious thing that one has to actually + + + align:start position:0% +obvious thing that one has to actually +understand at least the basic principles + + align:start position:0% +understand at least the basic principles + + + align:start position:0% +understand at least the basic principles +of how the measurement device works + + align:start position:0% +of how the measurement device works + + + align:start position:0% +of how the measurement device works +if you are going to be using it to in + + align:start position:0% +if you are going to be using it to in + + + align:start position:0% +if you are going to be using it to in +your undertaking of any biological + + align:start position:0% +your undertaking of any biological + + + align:start position:0% +your undertaking of any biological +endeavor right um you should know the + + align:start position:0% +endeavor right um you should know the + + + align:start position:0% +endeavor right um you should know the +relevance of the scanner setting things + + align:start position:0% +relevance of the scanner setting things + + + align:start position:0% +relevance of the scanner setting things +like that i'm not going to go through + + align:start position:0% +like that i'm not going to go through + + + align:start position:0% +like that i'm not going to go through +all of this it's quite obvious + + align:start position:0% +all of this it's quite obvious + + + align:start position:0% +all of this it's quite obvious +a lot of these things + + align:start position:0% +a lot of these things + + + align:start position:0% +a lot of these things +and + + align:start position:0% +and + + + align:start position:0% +and +you also have to be sure that the + + align:start position:0% +you also have to be sure that the + + + align:start position:0% +you also have to be sure that the +that the journey from uh + + align:start position:0% +that the journey from uh + + + align:start position:0% +that the journey from uh +image to the actual number itself does + + align:start position:0% +image to the actual number itself does + + + align:start position:0% +image to the actual number itself does +it go through an analytical or + + align:start position:0% +it go through an analytical or + + + align:start position:0% +it go through an analytical or +statistical processing software + + align:start position:0% +statistical processing software + + + align:start position:0% +statistical processing software +how far removed are you from the reality + + align:start position:0% +how far removed are you from the reality + + + align:start position:0% +how far removed are you from the reality +of the observation + + align:start position:0% +of the observation + + + align:start position:0% +of the observation +one should check for these things in + + align:start position:0% +one should check for these things in + + + align:start position:0% +one should check for these things in +fact + + align:start position:0% +fact + + + align:start position:0% +fact +um + + align:start position:0% +um + + + align:start position:0% +um +you know because subsequent stuff that + + align:start position:0% +you know because subsequent stuff that + + + align:start position:0% +you know because subsequent stuff that +you're going to be doing on this numbers + + align:start position:0% +you're going to be doing on this numbers + + + align:start position:0% +you're going to be doing on this numbers +will matter + + align:start position:0% +will matter + + + align:start position:0% +will matter +depending or will be um + + align:start position:0% +depending or will be um + + + align:start position:0% +depending or will be um +conditioned upon these factors + + align:start position:0% +conditioned upon these factors + + + align:start position:0% +conditioned upon these factors +so you get in the case of microarray + + align:start position:0% +so you get in the case of microarray + + + align:start position:0% +so you get in the case of microarray +it's basically a bright spot + + align:start position:0% +it's basically a bright spot + + + align:start position:0% +it's basically a bright spot +right and somehow you have to translate + + align:start position:0% +right and somehow you have to translate + + + align:start position:0% +right and somehow you have to translate +this brightness + + align:start position:0% +this brightness + + + align:start position:0% +this brightness +and the grid here is imaginary + + align:start position:0% +and the grid here is imaginary + + + align:start position:0% +and the grid here is imaginary +you know it doesn't just you won't see + + align:start position:0% +you know it doesn't just you won't see + + + align:start position:0% +you know it doesn't just you won't see +just + + align:start position:0% +just + + + align:start position:0% +just +very discreet grid lighting optically + + align:start position:0% +very discreet grid lighting optically + + + align:start position:0% +very discreet grid lighting optically +there is a a diffusion of of light from + + align:start position:0% +there is a a diffusion of of light from + + + align:start position:0% +there is a a diffusion of of light from +one feature to another so you have to + + align:start position:0% +one feature to another so you have to + + + align:start position:0% +one feature to another so you have to +basically translate this whole mess here + + align:start position:0% +basically translate this whole mess here + + + align:start position:0% +basically translate this whole mess here +down to a + + align:start position:0% +down to a + + + align:start position:0% +down to a +simplistic looking + + align:start position:0% +simplistic looking + + + align:start position:0% +simplistic looking +um table of numbers so you have + + align:start position:0% +um table of numbers so you have + + + align:start position:0% +um table of numbers so you have +genes + + align:start position:0% +genes + + + align:start position:0% +genes +measured across different samples and + + align:start position:0% +measured across different samples and + + + align:start position:0% +measured across different samples and +they're in quote-unquote intensity and + + align:start position:0% +they're in quote-unquote intensity and + + + align:start position:0% +they're in quote-unquote intensity and +next thing we'll do is to understand if + + align:start position:0% +next thing we'll do is to understand if + + + align:start position:0% +next thing we'll do is to understand if +these intensities themselves have a + + align:start position:0% +these intensities themselves have a + + + align:start position:0% +these intensities themselves have a +dimension associated with them say + + align:start position:0% +dimension associated with them say + + + align:start position:0% +dimension associated with them say +centimeters fahrenheit things like that + + align:start position:0% +centimeters fahrenheit things like that + + + align:start position:0% +centimeters fahrenheit things like that +or they have no + + align:start position:0% +or they have no + + + align:start position:0% +or they have no +dimensions at all + + align:start position:0% + + + + align:start position:0% + +so dimensionality and scales + + align:start position:0% +so dimensionality and scales + + + align:start position:0% +so dimensionality and scales +and + + align:start position:0% +and + + + align:start position:0% +and +i guess we should we can concentrate for + + align:start position:0% +i guess we should we can concentrate for + + + align:start position:0% +i guess we should we can concentrate for +a while on microarray data + + align:start position:0% +a while on microarray data + + + align:start position:0% +a while on microarray data +um + + align:start position:0% +um + + + align:start position:0% +um +in the case of two channel or + + align:start position:0% +in the case of two channel or + + + align:start position:0% +in the case of two channel or +competitive hybridization microarrays + + align:start position:0% +competitive hybridization microarrays + + + align:start position:0% +competitive hybridization microarrays +where you have um + + align:start position:0% +where you have um + + + align:start position:0% +where you have um +two dyes like size three and size five + + align:start position:0% +two dyes like size three and size five + + + align:start position:0% +two dyes like size three and size five +competing on on + + align:start position:0% +competing on on + + + align:start position:0% +competing on on +being being hybridized onto different + + align:start position:0% +being being hybridized onto different + + + align:start position:0% +being being hybridized onto different +tissue types and put onto one array + + align:start position:0% +tissue types and put onto one array + + + align:start position:0% +tissue types and put onto one array +the + + align:start position:0% +the + + + align:start position:0% +the +readout + + align:start position:0% +readout + + + align:start position:0% +readout +is arguably dimensionless because it has + + align:start position:0% +is arguably dimensionless because it has + + + align:start position:0% +is arguably dimensionless because it has +to do with the ratio and arithmetic + + align:start position:0% +to do with the ratio and arithmetic + + + align:start position:0% +to do with the ratio and arithmetic +tells you that the ratio operation + + align:start position:0% +tells you that the ratio operation + + + align:start position:0% +tells you that the ratio operation +nullifies or cancels out any dimension + + align:start position:0% +nullifies or cancels out any dimension + + + align:start position:0% +nullifies or cancels out any dimension +there is in the data + + align:start position:0% + + + + align:start position:0% + +second type species of microarrays are + + align:start position:0% +second type species of microarrays are + + + align:start position:0% +second type species of microarrays are +say oligonucleotide microarrays where + + align:start position:0% +say oligonucleotide microarrays where + + + align:start position:0% +say oligonucleotide microarrays where +there is no competition you have + + align:start position:0% +there is no competition you have + + + align:start position:0% +there is no competition you have +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +one tissue type you + + align:start position:0% +one tissue type you + + + align:start position:0% +one tissue type you +um + + align:start position:0% + + + + align:start position:0% + +put tag it with some fluorescence and + + align:start position:0% +put tag it with some fluorescence and + + + align:start position:0% +put tag it with some fluorescence and +then you hybridize it there is no + + align:start position:0% +then you hybridize it there is no + + + align:start position:0% +then you hybridize it there is no +competition whatsoever and the + + align:start position:0% +competition whatsoever and the + + + align:start position:0% +competition whatsoever and the +um + + align:start position:0% +um + + + align:start position:0% +um +registered intensities have some kind of + + align:start position:0% +registered intensities have some kind of + + + align:start position:0% +registered intensities have some kind of +units associated with them + + align:start position:0% +units associated with them + + + align:start position:0% +units associated with them +if anything you don't have to know the + + align:start position:0% +if anything you don't have to know the + + + align:start position:0% +if anything you don't have to know the +actual units + + align:start position:0% +actual units + + + align:start position:0% +actual units +it may be sufficient just to know if + + align:start position:0% +it may be sufficient just to know if + + + align:start position:0% +it may be sufficient just to know if +units exist or not dimensions or + + align:start position:0% +units exist or not dimensions or + + + align:start position:0% +units exist or not dimensions or +dimensionalness + + align:start position:0% +dimensionalness + + + align:start position:0% +dimensionalness +why + + align:start position:0% +why + + + align:start position:0% +why +because different math techniques + + align:start position:0% +because different math techniques + + + align:start position:0% +because different math techniques +actually will apply depending on whether + + align:start position:0% +actually will apply depending on whether + + + align:start position:0% +actually will apply depending on whether +the quantity is a is a dimension + + align:start position:0% +the quantity is a is a dimension + + + align:start position:0% +the quantity is a is a dimension +quantity or dimensionless one for + + align:start position:0% +quantity or dimensionless one for + + + align:start position:0% +quantity or dimensionless one for +example + + align:start position:0% +example + + + align:start position:0% +example +um + + align:start position:0% +um + + + align:start position:0% +um +if you are having intense you have + + align:start position:0% +if you are having intense you have + + + align:start position:0% +if you are having intense you have +dealing with a set of numbers which have + + align:start position:0% +dealing with a set of numbers which have + + + align:start position:0% +dealing with a set of numbers which have +to do with radiation measurements + + align:start position:0% +to do with radiation measurements + + + align:start position:0% +to do with radiation measurements +clearly phosphorus imagery is radiation + + align:start position:0% +clearly phosphorus imagery is radiation + + + align:start position:0% +clearly phosphorus imagery is radiation +then + + align:start position:0% +then + + + align:start position:0% +then +physics tells you that the underlying or + + align:start position:0% +physics tells you that the underlying or + + + align:start position:0% +physics tells you that the underlying or +the most sensible distribution to be + + align:start position:0% +the most sensible distribution to be + + + align:start position:0% +the most sensible distribution to be +background to be studying this system + + align:start position:0% +background to be studying this system + + + align:start position:0% +background to be studying this system +would be the gamma distribution + + align:start position:0% +would be the gamma distribution + + + align:start position:0% +would be the gamma distribution +secondly + + align:start position:0% +secondly + + + align:start position:0% +secondly +there are certain what you have probably + + align:start position:0% +there are certain what you have probably + + + align:start position:0% +there are certain what you have probably +heard as + + align:start position:0% +heard as + + + align:start position:0% +heard as +power or scaling laws that could be + + align:start position:0% +power or scaling laws that could be + + + align:start position:0% +power or scaling laws that could be +useful in detecting errors + + align:start position:0% +useful in detecting errors + + + align:start position:0% +useful in detecting errors +um in this set of numbers + + align:start position:0% +um in this set of numbers + + + align:start position:0% +um in this set of numbers +if they don't have a dimension or they + + align:start position:0% +if they don't have a dimension or they + + + align:start position:0% +if they don't have a dimension or they +have a dimension things laws such as + + align:start position:0% +have a dimension things laws such as + + + align:start position:0% +have a dimension things laws such as +ziff's law or benefits law like uh for + + align:start position:0% +ziff's law or benefits law like uh for + + + align:start position:0% +ziff's law or benefits law like uh for +instance the third digit of every um + + align:start position:0% +instance the third digit of every um + + + align:start position:0% +instance the third digit of every um +telephone number in this country things + + align:start position:0% +telephone number in this country things + + + align:start position:0% +telephone number in this country things +like that there is a certain underlying + + align:start position:0% +like that there is a certain underlying + + + align:start position:0% +like that there is a certain underlying +distribution that could be very useful + + align:start position:0% +distribution that could be very useful + + + align:start position:0% +distribution that could be very useful +in informing you what actually is random + + align:start position:0% +in informing you what actually is random + + + align:start position:0% +in informing you what actually is random +and what actually isn't because if you + + align:start position:0% +and what actually isn't because if you + + + align:start position:0% +and what actually isn't because if you +get a result + + align:start position:0% +get a result + + + align:start position:0% +get a result +you + + align:start position:0% +you + + + align:start position:0% +you +after some analysis that you do whatever + + align:start position:0% +after some analysis that you do whatever + + + align:start position:0% +after some analysis that you do whatever +it is you would like at least to be sure + + align:start position:0% +it is you would like at least to be sure + + + align:start position:0% +it is you would like at least to be sure +that that result is not arriving + + align:start position:0% +that that result is not arriving + + + align:start position:0% +that that result is not arriving +completely out of chance + + align:start position:0% +completely out of chance + + + align:start position:0% +completely out of chance +and that is the whole point of this that + + align:start position:0% +and that is the whole point of this that + + + align:start position:0% +and that is the whole point of this that +knowing the dimension-ness + + align:start position:0% +knowing the dimension-ness + + + align:start position:0% +knowing the dimension-ness +of the + + align:start position:0% +of the + + + align:start position:0% +of the +numbers could help you or guide you in + + align:start position:0% +numbers could help you or guide you in + + + align:start position:0% +numbers could help you or guide you in +formulating + + align:start position:0% +formulating + + + align:start position:0% +formulating +a null hypothesis for this data set + + align:start position:0% +a null hypothesis for this data set + + + align:start position:0% +a null hypothesis for this data set +um + + align:start position:0% +um + + + align:start position:0% +um +so that's + + align:start position:0% +so that's + + + align:start position:0% +so that's +dimensionality um why do you would so + + align:start position:0% +dimensionality um why do you would so + + + align:start position:0% +dimensionality um why do you would so +let's say you already have the numbers + + align:start position:0% +let's say you already have the numbers + + + align:start position:0% +let's say you already have the numbers +in front of you + + align:start position:0% +in front of you + + + align:start position:0% +in front of you +why would you want to transform it or + + align:start position:0% +why would you want to transform it or + + + align:start position:0% +why would you want to transform it or +rewrite it in a different format there + + align:start position:0% +rewrite it in a different format there + + + align:start position:0% +rewrite it in a different format there +are actually several very good reasons + + align:start position:0% +are actually several very good reasons + + + align:start position:0% +are actually several very good reasons +for doing it and it i'm sure it comes + + align:start position:0% +for doing it and it i'm sure it comes + + + align:start position:0% +for doing it and it i'm sure it comes +very obvious to a lot of people's heads + + align:start position:0% +very obvious to a lot of people's heads + + + align:start position:0% +very obvious to a lot of people's heads +number one + + align:start position:0% +number one + + + align:start position:0% +number one +it could simplify mathematical + + align:start position:0% +it could simplify mathematical + + + align:start position:0% +it could simplify mathematical +manipulation + + align:start position:0% +manipulation + + + align:start position:0% +manipulation +and secondly + + align:start position:0% +and secondly + + + align:start position:0% +and secondly +rewriting it in a certain way + + align:start position:0% +rewriting it in a certain way + + + align:start position:0% +rewriting it in a certain way +could uncover + + align:start position:0% +could uncover + + + align:start position:0% +could uncover +certain structures in the data + + align:start position:0% +certain structures in the data + + + align:start position:0% +certain structures in the data +we will see examples of these very + + align:start position:0% +we will see examples of these very + + + align:start position:0% +we will see examples of these very +shortly + + align:start position:0% +shortly + + + align:start position:0% +shortly +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so number number one simplifying + + align:start position:0% +so number number one simplifying + + + align:start position:0% +so number number one simplifying +mathematical manipulation + + align:start position:0% +mathematical manipulation + + + align:start position:0% +mathematical manipulation +it can be argued that + + align:start position:0% +it can be argued that + + + align:start position:0% +it can be argued that +any spreadsheet + + align:start position:0% +any spreadsheet + + + align:start position:0% +any spreadsheet +is + + align:start position:0% +is + + + align:start position:0% +is +essentially a matrix + + align:start position:0% +essentially a matrix + + + align:start position:0% +essentially a matrix +of course the entries of the matrices + + align:start position:0% +of course the entries of the matrices + + + align:start position:0% +of course the entries of the matrices +themselves are not homogeneous they can + + align:start position:0% +themselves are not homogeneous they can + + + align:start position:0% +themselves are not homogeneous they can +be very different and that could affect + + align:start position:0% +be very different and that could affect + + + align:start position:0% +be very different and that could affect +what kind of operations you can sensibly + + align:start position:0% +what kind of operations you can sensibly + + + align:start position:0% +what kind of operations you can sensibly +perform on them but essentially it is a + + align:start position:0% +perform on them but essentially it is a + + + align:start position:0% +perform on them but essentially it is a +matrix if + + align:start position:0% +matrix if + + + align:start position:0% +matrix if +there are numbers in these entries + + align:start position:0% +there are numbers in these entries + + + align:start position:0% +there are numbers in these entries +and as such if there are matrices and + + align:start position:0% +and as such if there are matrices and + + + align:start position:0% +and as such if there are matrices and +the entries are homogeneous they're + + align:start position:0% +the entries are homogeneous they're + + + align:start position:0% +the entries are homogeneous they're +subject to formal and very basic + + align:start position:0% +subject to formal and very basic + + + align:start position:0% +subject to formal and very basic +linear algebraic rules you could do a + + align:start position:0% +linear algebraic rules you could do a + + + align:start position:0% +linear algebraic rules you could do a +matrix addition subtraction etc and you + + align:start position:0% +matrix addition subtraction etc and you + + + align:start position:0% +matrix addition subtraction etc and you +could + + align:start position:0% +could + + + align:start position:0% +could +investigate the eigenvalues or the + + align:start position:0% +investigate the eigenvalues or the + + + align:start position:0% +investigate the eigenvalues or the +eigenvectors basically invariant + + align:start position:0% +eigenvectors basically invariant + + + align:start position:0% +eigenvectors basically invariant +structures within the data and + + align:start position:0% +structures within the data and + + + align:start position:0% +structures within the data and +of course the hope in any scientific + + align:start position:0% +of course the hope in any scientific + + + align:start position:0% +of course the hope in any scientific +endeavor is that these invariant + + align:start position:0% +endeavor is that these invariant + + + align:start position:0% +endeavor is that these invariant +structures somehow + + align:start position:0% +structures somehow + + + align:start position:0% +structures somehow +um + + align:start position:0% +um + + + align:start position:0% +um +are related + + align:start position:0% +are related + + + align:start position:0% +are related +to a + + align:start position:0% +to a + + + align:start position:0% +to a +physical phenomenon from which these + + align:start position:0% +physical phenomenon from which these + + + align:start position:0% +physical phenomenon from which these +numbers come from that is the hope of + + align:start position:0% +numbers come from that is the hope of + + + align:start position:0% +numbers come from that is the hope of +all scientists who + + align:start position:0% +all scientists who + + + align:start position:0% +all scientists who +who are you know + + align:start position:0% +who are you know + + + align:start position:0% +who are you know +trying to study a system + + align:start position:0% +trying to study a system + + + align:start position:0% +trying to study a system +this warning is obvious if your matrix + + align:start position:0% +this warning is obvious if your matrix + + + align:start position:0% +this warning is obvious if your matrix +if you are measuring say temperature + + align:start position:0% +if you are measuring say temperature + + + align:start position:0% +if you are measuring say temperature +and height + + align:start position:0% +and height + + + align:start position:0% +and height +and weight clearly you you can't just + + align:start position:0% +and weight clearly you you can't just + + + align:start position:0% +and weight clearly you you can't just +perform blindly um linear algebraic + + align:start position:0% +perform blindly um linear algebraic + + + align:start position:0% +perform blindly um linear algebraic +manipulations in this data and hope to + + align:start position:0% +manipulations in this data and hope to + + + align:start position:0% +manipulations in this data and hope to +get something sensible out of it + + align:start position:0% +get something sensible out of it + + + align:start position:0% +get something sensible out of it +but that's obvious + + align:start position:0% +but that's obvious + + + align:start position:0% +but that's obvious +okay why transform data number two + + align:start position:0% +okay why transform data number two + + + align:start position:0% +okay why transform data number two +second reason + + align:start position:0% +second reason + + + align:start position:0% +second reason +revealing intrinsic geometries + + align:start position:0% +revealing intrinsic geometries + + + align:start position:0% +revealing intrinsic geometries +um what is meant by intrinsic geometry + + align:start position:0% +um what is meant by intrinsic geometry + + + align:start position:0% +um what is meant by intrinsic geometry +it could be a variance structure in the + + align:start position:0% +it could be a variance structure in the + + + align:start position:0% +it could be a variance structure in the +data you could you may notice that you + + align:start position:0% +data you could you may notice that you + + + align:start position:0% +data you could you may notice that you +may not notice upon looking at the + + align:start position:0% +may not notice upon looking at the + + + align:start position:0% +may not notice upon looking at the +numbers themselves in a table that there + + align:start position:0% +numbers themselves in a table that there + + + align:start position:0% +numbers themselves in a table that there +is a + + align:start position:0% +is a + + + align:start position:0% +is a +a group of + + align:start position:0% +a group of + + + align:start position:0% +a group of +variables which are acting a certain way + + align:start position:0% +variables which are acting a certain way + + + align:start position:0% +variables which are acting a certain way +but it could turn out that if you write + + align:start position:0% +but it could turn out that if you write + + + align:start position:0% +but it could turn out that if you write +it or transform it + + align:start position:0% +it or transform it + + + align:start position:0% +it or transform it +this feature would stand out and we + + align:start position:0% +this feature would stand out and we + + + align:start position:0% +this feature would stand out and we +actually will see graphical examples of + + align:start position:0% +actually will see graphical examples of + + + align:start position:0% +actually will see graphical examples of +when that happens + + align:start position:0% +when that happens + + + align:start position:0% +when that happens +um + + align:start position:0% + + + + align:start position:0% + +let's see + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +there are actually + + align:start position:0% +there are actually + + + align:start position:0% +there are actually +i'm not sure if you need to know if + + align:start position:0% +i'm not sure if you need to know if + + + align:start position:0% +i'm not sure if you need to know if +there are clues to the existence of + + align:start position:0% +there are clues to the existence of + + + align:start position:0% +there are clues to the existence of +these structures but + + align:start position:0% +these structures but + + + align:start position:0% +these structures but +the + + align:start position:0% +the + + + align:start position:0% +the +oftentimes it's not obvious and you + + align:start position:0% +oftentimes it's not obvious and you + + + align:start position:0% +oftentimes it's not obvious and you +could use some help by transforming the + + align:start position:0% +could use some help by transforming the + + + align:start position:0% +could use some help by transforming the +data + + align:start position:0% +data + + + align:start position:0% +data +um + + align:start position:0% + + + + align:start position:0% + +now these + + align:start position:0% +now these + + + align:start position:0% +now these +internal structures may be explicit or + + align:start position:0% +internal structures may be explicit or + + + align:start position:0% +internal structures may be explicit or +implicit in what sense the explicit + + align:start position:0% +implicit in what sense the explicit + + + align:start position:0% +implicit in what sense the explicit +structures are clearly the notation you + + align:start position:0% +structures are clearly the notation you + + + align:start position:0% +structures are clearly the notation you +give like gene one gene two gene three + + align:start position:0% +give like gene one gene two gene three + + + align:start position:0% +give like gene one gene two gene three +or um condition one two and three these + + align:start position:0% +or um condition one two and three these + + + align:start position:0% +or um condition one two and three these +are very very obvious things all + + align:start position:0% +are very very obvious things all + + + align:start position:0% +are very very obvious things all +clinical phenotypes + + align:start position:0% +clinical phenotypes + + + align:start position:0% +clinical phenotypes +the + + align:start position:0% +the + + + align:start position:0% +the +the implicit ones are the relation + + align:start position:0% +the implicit ones are the relation + + + align:start position:0% +the implicit ones are the relation +between uh gene + + align:start position:0% +between uh gene + + + align:start position:0% +between uh gene +how they interact with one another at + + align:start position:0% +how they interact with one another at + + + align:start position:0% +how they interact with one another at +least as captured by these numbers now + + align:start position:0% +least as captured by these numbers now + + + align:start position:0% +least as captured by these numbers now +that you don't know for sure you + + align:start position:0% +that you don't know for sure you + + + align:start position:0% +that you don't know for sure you +actually have to go in and look for them + + align:start position:0% +actually have to go in and look for them + + + align:start position:0% +actually have to go in and look for them +but it's just good to keep in mind that + + align:start position:0% +but it's just good to keep in mind that + + + align:start position:0% +but it's just good to keep in mind that +this aspect explicit and implicitness of + + align:start position:0% +this aspect explicit and implicitness of + + + align:start position:0% +this aspect explicit and implicitness of +these structures + + align:start position:0% + + + + align:start position:0% + +um well the whole idea of um + + align:start position:0% +um well the whole idea of um + + + align:start position:0% +um well the whole idea of um +is a bit of a jump from data + + align:start position:0% +is a bit of a jump from data + + + align:start position:0% +is a bit of a jump from data +transformation to modeling + + align:start position:0% +transformation to modeling + + + align:start position:0% +transformation to modeling +use + + align:start position:0% +use + + + align:start position:0% +use +this is the real world system and here + + align:start position:0% +this is the real world system and here + + + align:start position:0% +this is the real world system and here +is what exists in our heads or at least + + align:start position:0% +is what exists in our heads or at least + + + align:start position:0% +is what exists in our heads or at least +in our computers + + align:start position:0% +in our computers + + + align:start position:0% +in our computers +are you trying to understand a system + + align:start position:0% +are you trying to understand a system + + + align:start position:0% +are you trying to understand a system +physical phenomenon say and it's going + + align:start position:0% +physical phenomenon say and it's going + + + align:start position:0% +physical phenomenon say and it's going +to be + + align:start position:0% +to be + + + align:start position:0% +to be +there's some clearly has to be some + + align:start position:0% +there's some clearly has to be some + + + align:start position:0% +there's some clearly has to be some +physical quantity one is measuring + + align:start position:0% +physical quantity one is measuring + + + align:start position:0% +physical quantity one is measuring +and this physical quantity is subject to + + align:start position:0% +and this physical quantity is subject to + + + align:start position:0% +and this physical quantity is subject to +some kind of perturbation + + align:start position:0% +some kind of perturbation + + + align:start position:0% +some kind of perturbation +you make your measurement here this is + + align:start position:0% +you make your measurement here this is + + + align:start position:0% +you make your measurement here this is +where the data representation occurs you + + align:start position:0% +where the data representation occurs you + + + align:start position:0% +where the data representation occurs you +map it into a set of numbers or symbols + + align:start position:0% +map it into a set of numbers or symbols + + + align:start position:0% +map it into a set of numbers or symbols +which there's an algebra + + align:start position:0% +which there's an algebra + + + align:start position:0% +which there's an algebra +on it + + align:start position:0% +on it + + + align:start position:0% +on it +and then + + align:start position:0% +and then + + + align:start position:0% +and then +any perturbation of the field of this + + align:start position:0% +any perturbation of the field of this + + + align:start position:0% +any perturbation of the field of this +physical system will manifest itself as + + align:start position:0% +physical system will manifest itself as + + + align:start position:0% +physical system will manifest itself as +numeric fluctuations + + align:start position:0% +numeric fluctuations + + + align:start position:0% +numeric fluctuations +and often times + + align:start position:0% +and often times + + + align:start position:0% +and often times +when you get a lot of data it's not + + align:start position:0% +when you get a lot of data it's not + + + align:start position:0% +when you get a lot of data it's not +clear + + align:start position:0% +clear + + + align:start position:0% +clear +if you're actually seeing a fluctuation + + align:start position:0% +if you're actually seeing a fluctuation + + + align:start position:0% +if you're actually seeing a fluctuation +or you're just seeing quote-unquote + + align:start position:0% +or you're just seeing quote-unquote + + + align:start position:0% +or you're just seeing quote-unquote +noise okay + + align:start position:0% +noise okay + + + align:start position:0% +noise okay +and then you form a model of the system + + align:start position:0% +and then you form a model of the system + + + align:start position:0% +and then you form a model of the system +and hopefully your model somehow will + + align:start position:0% +and hopefully your model somehow will + + + align:start position:0% +and hopefully your model somehow will +corroborate with the physical phenomena + + align:start position:0% +corroborate with the physical phenomena + + + align:start position:0% +corroborate with the physical phenomena +i mean these are very obvious ideas of + + align:start position:0% +i mean these are very obvious ideas of + + + align:start position:0% +i mean these are very obvious ideas of +modeling + + align:start position:0% + + + + align:start position:0% + +now i give an example of uncovering + + align:start position:0% +now i give an example of uncovering + + + align:start position:0% +now i give an example of uncovering +internal structures now let's say that + + align:start position:0% +internal structures now let's say that + + + align:start position:0% +internal structures now let's say that +you have two different patient + + align:start position:0% +you have two different patient + + + align:start position:0% +you have two different patient +populations um x and o like + + align:start position:0% +populations um x and o like + + + align:start position:0% +populations um x and o like +okay say the x's are cancer patients the + + align:start position:0% +okay say the x's are cancer patients the + + + align:start position:0% +okay say the x's are cancer patients the +all uh + + align:start position:0% +all uh + + + align:start position:0% +all uh +normal patients and they have been + + align:start position:0% +normal patients and they have been + + + align:start position:0% +normal patients and they have been +controlled for age gender etc things + + align:start position:0% +controlled for age gender etc things + + + align:start position:0% +controlled for age gender etc things +like that + + align:start position:0% +like that + + + align:start position:0% +like that +and for each patient you make two gene + + align:start position:0% +and for each patient you make two gene + + + align:start position:0% +and for each patient you make two gene +measurements rna measurements protein + + align:start position:0% +measurements rna measurements protein + + + align:start position:0% +measurements rna measurements protein +doesn't really matter this is just an + + align:start position:0% +doesn't really matter this is just an + + + align:start position:0% +doesn't really matter this is just an +illustration and let's call the + + align:start position:0% +illustration and let's call the + + + align:start position:0% +illustration and let's call the +measurements g1 and g2 + + align:start position:0% +measurements g1 and g2 + + + align:start position:0% +measurements g1 and g2 +okay so each patient you measure two of + + align:start position:0% +okay so each patient you measure two of + + + align:start position:0% +okay so each patient you measure two of +these quantities + + align:start position:0% +these quantities + + + align:start position:0% +these quantities +now + + align:start position:0% +now + + + align:start position:0% +now +let's graphically represent this data + + align:start position:0% +let's graphically represent this data + + + align:start position:0% +let's graphically represent this data +after all we're talking about data + + align:start position:0% +after all we're talking about data + + + align:start position:0% +after all we're talking about data +representation all right and let's + + align:start position:0% +representation all right and let's + + + align:start position:0% +representation all right and let's +suppose that the our measurements came + + align:start position:0% +suppose that the our measurements came + + + align:start position:0% +suppose that the our measurements came +out this way + + align:start position:0% +out this way + + + align:start position:0% +out this way +okay + + align:start position:0% + + + + align:start position:0% + +now what is the point here + + align:start position:0% +now what is the point here + + + align:start position:0% +now what is the point here +that i'm trying to make well if you were + + align:start position:0% +that i'm trying to make well if you were + + + align:start position:0% +that i'm trying to make well if you were +simply look using + + align:start position:0% +simply look using + + + align:start position:0% +simply look using +measurement one + + align:start position:0% +measurement one + + + align:start position:0% +measurement one +and trying to use measurement once and + + align:start position:0% +and trying to use measurement once and + + + align:start position:0% +and trying to use measurement once and +how to discriminate between the crosses + + align:start position:0% +how to discriminate between the crosses + + + align:start position:0% +how to discriminate between the crosses +and the zeros + + align:start position:0% +and the zeros + + + align:start position:0% +and the zeros +it will not work right do you see why it + + align:start position:0% +it will not work right do you see why it + + + align:start position:0% +it will not work right do you see why it +does not work + + align:start position:0% +does not work + + + align:start position:0% +does not work +basically you simply project + + align:start position:0% +basically you simply project + + + align:start position:0% +basically you simply project +the x's and the zeros onto the + + align:start position:0% +the x's and the zeros onto the + + + align:start position:0% +the x's and the zeros onto the +um the g1 axis here + + align:start position:0% +um the g1 axis here + + + align:start position:0% +um the g1 axis here +okay if you project it you notice that + + align:start position:0% +okay if you project it you notice that + + + align:start position:0% +okay if you project it you notice that +there is a + + align:start position:0% +there is a + + + align:start position:0% +there is a +just a + + align:start position:0% +just a + + + align:start position:0% +just a +alternation of crosses and axis right + + align:start position:0% +alternation of crosses and axis right + + + align:start position:0% +alternation of crosses and axis right +they don't + + align:start position:0% +they don't + + + align:start position:0% +they don't +so g1 by itself certainly does not + + align:start position:0% +so g1 by itself certainly does not + + + align:start position:0% +so g1 by itself certainly does not +discriminate the cancer from the normal + + align:start position:0% +discriminate the cancer from the normal + + + align:start position:0% +discriminate the cancer from the normal +the same goes for quantity g2 if you + + align:start position:0% +the same goes for quantity g2 if you + + + align:start position:0% +the same goes for quantity g2 if you +project this onto + + align:start position:0% +project this onto + + + align:start position:0% +project this onto +the g2 axis you don't see uh + + align:start position:0% +the g2 axis you don't see uh + + + align:start position:0% +the g2 axis you don't see uh +that g2 actually segregates the two + + align:start position:0% +that g2 actually segregates the two + + + align:start position:0% +that g2 actually segregates the two +different population samples + + align:start position:0% + + + + align:start position:0% + +however + + align:start position:0% +however + + + align:start position:0% +however +now when you perform something called + + align:start position:0% +now when you perform something called + + + align:start position:0% +now when you perform something called +principal component analysis which we + + align:start position:0% +principal component analysis which we + + + align:start position:0% +principal component analysis which we +will briefly touch on but it is very + + align:start position:0% +will briefly touch on but it is very + + + align:start position:0% +will briefly touch on but it is very +standard in any textbook basically on + + align:start position:0% +standard in any textbook basically on + + + align:start position:0% +standard in any textbook basically on +multivariate analysis + + align:start position:0% +multivariate analysis + + + align:start position:0% +multivariate analysis +the data is simply rotated + + align:start position:0% +the data is simply rotated + + + align:start position:0% +the data is simply rotated +it's an fn transformation this is + + align:start position:0% +it's an fn transformation this is + + + align:start position:0% +it's an fn transformation this is +rotational translation and now in this + + align:start position:0% +rotational translation and now in this + + + align:start position:0% +rotational translation and now in this +new coordinates um principle component + + align:start position:0% +new coordinates um principle component + + + align:start position:0% +new coordinates um principle component +one and two + + align:start position:0% +one and two + + + align:start position:0% +one and two +what this is how it looks okay the same + + align:start position:0% +what this is how it looks okay the same + + + align:start position:0% +what this is how it looks okay the same +picture and and what do you see it's the + + align:start position:0% +picture and and what do you see it's the + + + align:start position:0% +picture and and what do you see it's the +same thing right you're just rotating + + align:start position:0% +same thing right you're just rotating + + + align:start position:0% +same thing right you're just rotating +but the the simple act of rotation + + align:start position:0% +but the the simple act of rotation + + + align:start position:0% +but the the simple act of rotation +itself is highly useful why + + align:start position:0% +itself is highly useful why + + + align:start position:0% +itself is highly useful why +well you notice then that + + align:start position:0% +well you notice then that + + + align:start position:0% +well you notice then that +while pc1 + + align:start position:0% +while pc1 + + + align:start position:0% +while pc1 +does not distinguish the two populations + + align:start position:0% +does not distinguish the two populations + + + align:start position:0% +does not distinguish the two populations +pcs2 certainly does + + align:start position:0% +pcs2 certainly does + + + align:start position:0% +pcs2 certainly does +and discriminating quantity is g1 minus + + align:start position:0% +and discriminating quantity is g1 minus + + + align:start position:0% +and discriminating quantity is g1 minus +g2 + + align:start position:0% +g2 + + + align:start position:0% +g2 +if g1 minus g2 is positive or negative + + align:start position:0% +if g1 minus g2 is positive or negative + + + align:start position:0% +if g1 minus g2 is positive or negative +you are either cancer or you are normal + + align:start position:0% +you are either cancer or you are normal + + + align:start position:0% +you are either cancer or you are normal +this is the beauty of this technique and + + align:start position:0% +this is the beauty of this technique and + + + align:start position:0% +this is the beauty of this technique and +why is this so this is a very + + align:start position:0% +why is this so this is a very + + + align:start position:0% +why is this so this is a very +kindergarten example + + align:start position:0% +kindergarten example + + + align:start position:0% +kindergarten example +but there's something to be learned from + + align:start position:0% +but there's something to be learned from + + + align:start position:0% +but there's something to be learned from +here because um as human beings we can't + + align:start position:0% +here because um as human beings we can't + + + align:start position:0% +here because um as human beings we can't +visualize beyond three or four + + align:start position:0% +visualize beyond three or four + + + align:start position:0% +visualize beyond three or four +dimensions and when you're making + + align:start position:0% +dimensions and when you're making + + + align:start position:0% +dimensions and when you're making +multiple measurements + + align:start position:0% +multiple measurements + + + align:start position:0% +multiple measurements +and + + align:start position:0% +and + + + align:start position:0% +and +so imagine that you are a person who + + align:start position:0% +so imagine that you are a person who + + + align:start position:0% +so imagine that you are a person who +lives in one dimension and you are + + align:start position:0% +lives in one dimension and you are + + + align:start position:0% +lives in one dimension and you are +making these two measurements + + align:start position:0% +making these two measurements + + + align:start position:0% +making these two measurements +your vision of this whole process + + align:start position:0% +your vision of this whole process + + + align:start position:0% +your vision of this whole process +is + + align:start position:0% +is + + + align:start position:0% +is +is only somehow captured in this + + align:start position:0% +is only somehow captured in this + + + align:start position:0% +is only somehow captured in this +projection projections onto g1 and g2 so + + align:start position:0% +projection projections onto g1 and g2 so + + + align:start position:0% +projection projections onto g1 and g2 so +in your one-dimensional world in mind i + + align:start position:0% +in your one-dimensional world in mind i + + + align:start position:0% +in your one-dimensional world in mind i +would not have realized that g1 or g2 + + align:start position:0% +would not have realized that g1 or g2 + + + align:start position:0% +would not have realized that g1 or g2 +actually does anything + + align:start position:0% +actually does anything + + + align:start position:0% +actually does anything +however this transformation + + align:start position:0% +however this transformation + + + align:start position:0% +however this transformation +helps me because then + + align:start position:0% +helps me because then + + + align:start position:0% +helps me because then +with using this one dimension alone + + align:start position:0% +with using this one dimension alone + + + align:start position:0% +with using this one dimension alone +remember i am a one-dimensional beast i + + align:start position:0% +remember i am a one-dimensional beast i + + + align:start position:0% +remember i am a one-dimensional beast i +can tell + + align:start position:0% +can tell + + + align:start position:0% +can tell +that this quantity here it's a linear + + align:start position:0% +that this quantity here it's a linear + + + align:start position:0% +that this quantity here it's a linear +combination actually distinguishes one + + align:start position:0% +combination actually distinguishes one + + + align:start position:0% +combination actually distinguishes one +from the other + + align:start position:0% +from the other + + + align:start position:0% +from the other +and imagine now you have 10 000 + + align:start position:0% +and imagine now you have 10 000 + + + align:start position:0% +and imagine now you have 10 000 +variables not just three and the power + + align:start position:0% +variables not just three and the power + + + align:start position:0% +variables not just three and the power +of this method immediately comes + + align:start position:0% +of this method immediately comes + + + align:start position:0% +of this method immediately comes +to the four + + align:start position:0% +to the four + + + align:start position:0% +to the four +another example + + align:start position:0% +another example + + + align:start position:0% +another example +say you have + + align:start position:0% +say you have + + + align:start position:0% +say you have +um + + align:start position:0% +um + + + align:start position:0% +um +two different so each dot is a gene + + align:start position:0% +two different so each dot is a gene + + + align:start position:0% +two different so each dot is a gene +and you have um + + align:start position:0% +and you have um + + + align:start position:0% +and you have um +let's just suppose that you have two + + align:start position:0% +let's just suppose that you have two + + + align:start position:0% +let's just suppose that you have two +patients or two persons or + + align:start position:0% +patients or two persons or + + + align:start position:0% +patients or two persons or +two animals + + align:start position:0% +two animals + + + align:start position:0% +two animals +uh red and blue animals and for each + + align:start position:0% +uh red and blue animals and for each + + + align:start position:0% +uh red and blue animals and for each +animal you measure 5 000 genes + + align:start position:0% +animal you measure 5 000 genes + + + align:start position:0% +animal you measure 5 000 genes +all right + + align:start position:0% +all right + + + align:start position:0% +all right +and these 5 000 genes are measured under + + align:start position:0% +and these 5 000 genes are measured under + + + align:start position:0% +and these 5 000 genes are measured under +three conditions so you could get a + + align:start position:0% +three conditions so you could get a + + + align:start position:0% +three conditions so you could get a +brown mouse and a white mouth + + align:start position:0% +brown mouse and a white mouth + + + align:start position:0% +brown mouse and a white mouth +microarray 5000 protein levels or + + align:start position:0% +microarray 5000 protein levels or + + + align:start position:0% +microarray 5000 protein levels or +something + + align:start position:0% +something + + + align:start position:0% +something +under three different conditions say + + align:start position:0% +under three different conditions say + + + align:start position:0% +under three different conditions say +heat shock starvation + + align:start position:0% +heat shock starvation + + + align:start position:0% +heat shock starvation +exercise + + align:start position:0% +exercise + + + align:start position:0% +exercise +okay and then you plot it + + align:start position:0% +okay and then you plot it + + + align:start position:0% +okay and then you plot it +right + + align:start position:0% +right + + + align:start position:0% +right +now + + align:start position:0% + + + + align:start position:0% + +let let's um + + align:start position:0% +let let's um + + + align:start position:0% +let let's um +i hope you're not colorblind but let's + + align:start position:0% +i hope you're not colorblind but let's + + + align:start position:0% +i hope you're not colorblind but let's +suppose that the uh the red and blue + + align:start position:0% +suppose that the uh the red and blue + + + align:start position:0% +suppose that the uh the red and blue +are not there all you see is one color + + align:start position:0% +are not there all you see is one color + + + align:start position:0% +are not there all you see is one color +and you did this measurement okay + + align:start position:0% +and you did this measurement okay + + + align:start position:0% +and you did this measurement okay +and let's say you have a + + align:start position:0% +and let's say you have a + + + align:start position:0% +and let's say you have a +three-dimensional vision of this whole + + align:start position:0% +three-dimensional vision of this whole + + + align:start position:0% +three-dimensional vision of this whole +process + + align:start position:0% +process + + + align:start position:0% +process +look at the projections here here and + + align:start position:0% +look at the projections here here and + + + align:start position:0% +look at the projections here here and +here + + align:start position:0% +here + + + align:start position:0% +here +two-dimensional projections you don't + + align:start position:0% +two-dimensional projections you don't + + + align:start position:0% +two-dimensional projections you don't +actually see that the that this you know + + align:start position:0% +actually see that the that this you know + + + align:start position:0% +actually see that the that this you know +blue and red are just together right + + align:start position:0% +blue and red are just together right + + + align:start position:0% +blue and red are just together right +now if you do the same principle + + align:start position:0% +now if you do the same principle + + + align:start position:0% +now if you do the same principle +component analysis + + align:start position:0% +component analysis + + + align:start position:0% +component analysis +simply rotating the data remember it's + + align:start position:0% +simply rotating the data remember it's + + + align:start position:0% +simply rotating the data remember it's +simply an f5 transformation + + align:start position:0% +simply an f5 transformation + + + align:start position:0% +simply an f5 transformation +the first projection you see nothing but + + align:start position:0% +the first projection you see nothing but + + + align:start position:0% +the first projection you see nothing but +this is where the power comes + + align:start position:0% +this is where the power comes + + + align:start position:0% +this is where the power comes +again you have to somehow remove the + + align:start position:0% +again you have to somehow remove the + + + align:start position:0% +again you have to somehow remove the +green at the blue and the red + + align:start position:0% +green at the blue and the red + + + align:start position:0% +green at the blue and the red +and you see that clearly + + align:start position:0% +and you see that clearly + + + align:start position:0% +and you see that clearly +the two populations reveal themselves in + + align:start position:0% +the two populations reveal themselves in + + + align:start position:0% +the two populations reveal themselves in +a lower dimension that's the whole point + + align:start position:0% +a lower dimension that's the whole point + + + align:start position:0% +a lower dimension that's the whole point +um so we are cutting down from three + + align:start position:0% +um so we are cutting down from three + + + align:start position:0% +um so we are cutting down from three +to two basically just one dimension + + align:start position:0% +to two basically just one dimension + + + align:start position:0% +to two basically just one dimension +clearly one dimension actually + + align:start position:0% +clearly one dimension actually + + + align:start position:0% +clearly one dimension actually +distinguishes the two different + + align:start position:0% +distinguishes the two different + + + align:start position:0% +distinguishes the two different +populations the power is like you could + + align:start position:0% +populations the power is like you could + + + align:start position:0% +populations the power is like you could +have ten thousand dimensions it cuts it + + align:start position:0% +have ten thousand dimensions it cuts it + + + align:start position:0% +have ten thousand dimensions it cuts it +down all the way to the first + + align:start position:0% +down all the way to the first + + + align:start position:0% +down all the way to the first +five or ten it depends on the system + + align:start position:0% +five or ten it depends on the system + + + align:start position:0% +five or ten it depends on the system +it's just a demonstration but this is + + align:start position:0% +it's just a demonstration but this is + + + align:start position:0% +it's just a demonstration but this is +simulated data by the way it's not real + + align:start position:0% +simulated data by the way it's not real + + + align:start position:0% +simulated data by the way it's not real +but + + align:start position:0% +but + + + align:start position:0% +but +um data transformation example two i'm + + align:start position:0% +um data transformation example two i'm + + + align:start position:0% +um data transformation example two i'm +not quite sure now why i give you all + + align:start position:0% +not quite sure now why i give you all + + + align:start position:0% +not quite sure now why i give you all +these principal component analysis + + align:start position:0% +these principal component analysis + + + align:start position:0% +these principal component analysis +examples + + align:start position:0% +examples + + + align:start position:0% +examples +but um this is actually real data um + + align:start position:0% +but um this is actually real data um + + + align:start position:0% +but um this is actually real data um +pancreatic development time series + + align:start position:0% +pancreatic development time series + + + align:start position:0% +pancreatic development time series +and + + align:start position:0% +and + + + align:start position:0% +and +at i think it was 11 time points + + align:start position:0% +at i think it was 11 time points + + + align:start position:0% +at i think it was 11 time points +versus + + align:start position:0% +versus + + + align:start position:0% +versus +something like 10 000 genes i believe + + align:start position:0% +something like 10 000 genes i believe + + + align:start position:0% +something like 10 000 genes i believe +i'm not quite sure + + align:start position:0% +i'm not quite sure + + + align:start position:0% +i'm not quite sure +so it's a matrix + + align:start position:0% +so it's a matrix + + + align:start position:0% +so it's a matrix +now there are two ways to look at the + + align:start position:0% +now there are two ways to look at the + + + align:start position:0% +now there are two ways to look at the +system right it's a it's basically say + + align:start position:0% +system right it's a it's basically say + + + align:start position:0% +system right it's a it's basically say +10 000 genes + + align:start position:0% +10 000 genes + + + align:start position:0% +10 000 genes +by + + align:start position:0% +by + + + align:start position:0% +by +11 conditions + + align:start position:0% +11 conditions + + + align:start position:0% +11 conditions +you can look at it as um + + align:start position:0% +you can look at it as um + + + align:start position:0% +you can look at it as um +as time points + + align:start position:0% +as time points + + + align:start position:0% +as time points +in a + + align:start position:0% +in a + + + align:start position:0% +in a +gene space + + align:start position:0% +gene space + + + align:start position:0% +gene space +10 000 dimensions that's one vision of + + align:start position:0% +10 000 dimensions that's one vision of + + + align:start position:0% +10 000 dimensions that's one vision of +this experiment + + align:start position:0% +this experiment + + + align:start position:0% +this experiment +the other vision is the transpose vision + + align:start position:0% +the other vision is the transpose vision + + + align:start position:0% +the other vision is the transpose vision +which is + + align:start position:0% +which is + + + align:start position:0% +which is +the the objects the graphical objects + + align:start position:0% +the the objects the graphical objects + + + align:start position:0% +the the objects the graphical objects +normal genes + + align:start position:0% +normal genes + + + align:start position:0% +normal genes +and they live in 11 dimensional sample + + align:start position:0% +and they live in 11 dimensional sample + + + align:start position:0% +and they live in 11 dimensional sample +space or temporal space + + align:start position:0% +space or temporal space + + + align:start position:0% +space or temporal space +i hope you see that so there are two + + align:start position:0% +i hope you see that so there are two + + + align:start position:0% +i hope you see that so there are two +ways to look at this study and the two + + align:start position:0% +ways to look at this study and the two + + + align:start position:0% +ways to look at this study and the two +ways that when you do further analysis + + align:start position:0% +ways that when you do further analysis + + + align:start position:0% +ways that when you do further analysis +on them will actually and um + + align:start position:0% +on them will actually and um + + + align:start position:0% +on them will actually and um +bring up different aspects of + + align:start position:0% +bring up different aspects of + + + align:start position:0% +bring up different aspects of +of um the experiment okay so um + + align:start position:0% +of um the experiment okay so um + + + align:start position:0% +of um the experiment okay so um +you know you can look at the system + + align:start position:0% +you know you can look at the system + + + align:start position:0% +you know you can look at the system +sample wise meaning that + + align:start position:0% + + + + align:start position:0% + +dots + + align:start position:0% +dots + + + align:start position:0% +dots +dots genes in + + align:start position:0% +dots genes in + + + align:start position:0% +dots genes in +time space or you can look at them gene + + align:start position:0% +time space or you can look at them gene + + + align:start position:0% +time space or you can look at them gene +wise + + align:start position:0% +wise + + + align:start position:0% +wise +actually the names could have been + + align:start position:0% +actually the names could have been + + + align:start position:0% +actually the names could have been +switched + + align:start position:0% +switched + + + align:start position:0% +switched +which is uh each point is a time + + align:start position:0% +which is uh each point is a time + + + align:start position:0% +which is uh each point is a time +it's a whole uh pancreas + + align:start position:0% +it's a whole uh pancreas + + + align:start position:0% +it's a whole uh pancreas +and the space it's sitting on is + + align:start position:0% +and the space it's sitting on is + + + align:start position:0% +and the space it's sitting on is +actually genes so like 10 000 dimensions + + align:start position:0% +actually genes so like 10 000 dimensions + + + align:start position:0% +actually genes so like 10 000 dimensions +and cld is basically central limit + + align:start position:0% +and cld is basically central limit + + + align:start position:0% +and cld is basically central limit +theorem scaling it's a fancy term for + + align:start position:0% +theorem scaling it's a fancy term for + + + align:start position:0% +theorem scaling it's a fancy term for +saying you normalize the data to mean + + align:start position:0% +saying you normalize the data to mean + + + align:start position:0% +saying you normalize the data to mean +zero variance one there are reasons + + align:start position:0% +zero variance one there are reasons + + + align:start position:0% +zero variance one there are reasons +actually do it but we we come to that + + align:start position:0% +actually do it but we we come to that + + + align:start position:0% +actually do it but we we come to that +later + + align:start position:0% + + + + align:start position:0% + +so the division of each dot being a gene + + align:start position:0% +so the division of each dot being a gene + + + align:start position:0% +so the division of each dot being a gene +sitting in time space i'm only throwing + + align:start position:0% +sitting in time space i'm only throwing + + + align:start position:0% +sitting in time space i'm only throwing +you three times at 11. okay + + align:start position:0% +you three times at 11. okay + + + align:start position:0% +you three times at 11. okay +well when you do the prince when you + + align:start position:0% +well when you do the prince when you + + + align:start position:0% +well when you do the prince when you +don't do anything at all you just plot + + align:start position:0% +don't do anything at all you just plot + + + align:start position:0% +don't do anything at all you just plot +it + + align:start position:0% +it + + + align:start position:0% +it +you get this cloud + + align:start position:0% +you get this cloud + + + align:start position:0% +you get this cloud +okay + + align:start position:0% +okay + + + align:start position:0% +okay +it's not very informative really + + align:start position:0% +it's not very informative really + + + align:start position:0% +it's not very informative really +maybe there is some information but i + + align:start position:0% +maybe there is some information but i + + + align:start position:0% +maybe there is some information but i +didn't go deeper into seeing what these + + align:start position:0% +didn't go deeper into seeing what these + + + align:start position:0% +didn't go deeper into seeing what these +things did + + align:start position:0% +things did + + + align:start position:0% +things did +now + + align:start position:0% +now + + + align:start position:0% +now +when you do a principal component + + align:start position:0% +when you do a principal component + + + align:start position:0% +when you do a principal component +analysis of the + + align:start position:0% +analysis of the + + + align:start position:0% +analysis of the +time axis + + align:start position:0% +time axis + + + align:start position:0% +time axis +and we plot this what you see is a + + align:start position:0% +and we plot this what you see is a + + + align:start position:0% +and we plot this what you see is a +circular object and the the reason is + + align:start position:0% +circular object and the the reason is + + + align:start position:0% +circular object and the the reason is +actually i'm circular or looks like an + + align:start position:0% +actually i'm circular or looks like an + + + align:start position:0% +actually i'm circular or looks like an +egg is because of the scaling + + align:start position:0% +egg is because of the scaling + + + align:start position:0% +egg is because of the scaling +um this + + align:start position:0% +um this + + + align:start position:0% +um this +scaling if you know linear algebra + + align:start position:0% +scaling if you know linear algebra + + + align:start position:0% +scaling if you know linear algebra +actually maps everything to the unit + + align:start position:0% +actually maps everything to the unit + + + align:start position:0% +actually maps everything to the unit +hypersphere which is why it's not + + align:start position:0% +hypersphere which is why it's not + + + align:start position:0% +hypersphere which is why it's not +surprising to get an egg shape like this + + align:start position:0% +surprising to get an egg shape like this + + + align:start position:0% +surprising to get an egg shape like this +but why is this more informative than + + align:start position:0% +but why is this more informative than + + + align:start position:0% +but why is this more informative than +the previous one the previous slide + + align:start position:0% +the previous one the previous slide + + + align:start position:0% +the previous one the previous slide +there is a reason so um + + align:start position:0% +there is a reason so um + + + align:start position:0% +there is a reason so um +i will claim actually that the density + + align:start position:0% +i will claim actually that the density + + + align:start position:0% +i will claim actually that the density +of the oh and uh the first principle + + align:start position:0% +of the oh and uh the first principle + + + align:start position:0% +of the oh and uh the first principle +component captures 45 percent of the + + align:start position:0% +component captures 45 percent of the + + + align:start position:0% +component captures 45 percent of the +variance + + align:start position:0% +variance + + + align:start position:0% +variance +second principle component captures 15 + + align:start position:0% +second principle component captures 15 + + + align:start position:0% +second principle component captures 15 +so the idea principle component analysis + + align:start position:0% +so the idea principle component analysis + + + align:start position:0% +so the idea principle component analysis +is that + + align:start position:0% +is that + + + align:start position:0% +is that +as you um + + align:start position:0% +as you um + + + align:start position:0% +as you um +the first principle commonly captures + + align:start position:0% +the first principle commonly captures + + + align:start position:0% +the first principle commonly captures +the greatest amount of variance the + + align:start position:0% +the greatest amount of variance the + + + align:start position:0% +the greatest amount of variance the +second catches the second greatest third + + align:start position:0% +second catches the second greatest third + + + align:start position:0% +second catches the second greatest third +etc they are all orthogonal one to the + + align:start position:0% +etc they are all orthogonal one to the + + + align:start position:0% +etc they are all orthogonal one to the +other + + align:start position:0% +other + + + align:start position:0% +other +um + + align:start position:0% + + + + align:start position:0% + +also so the the utility of doing this is + + align:start position:0% +also so the the utility of doing this is + + + align:start position:0% +also so the the utility of doing this is +now you can i claim that you can + + align:start position:0% +now you can i claim that you can + + + align:start position:0% +now you can i claim that you can +actually represent + + align:start position:0% +actually represent + + + align:start position:0% +actually represent +10 000 different profiles in a + + align:start position:0% +10 000 different profiles in a + + + align:start position:0% +10 000 different profiles in a +convenient egg shape like this + + align:start position:0% +convenient egg shape like this + + + align:start position:0% +convenient egg shape like this +how so + + align:start position:0% +how so + + + align:start position:0% +how so +well + + align:start position:0% +well + + + align:start position:0% +well +the first component captures a lot of + + align:start position:0% +the first component captures a lot of + + + align:start position:0% +the first component captures a lot of +variants in the system and if you + + align:start position:0% +variants in the system and if you + + + align:start position:0% +variants in the system and if you +so + + align:start position:0% +so + + + align:start position:0% +so +what is the profile of a gene if you + + align:start position:0% +what is the profile of a gene if you + + + align:start position:0% +what is the profile of a gene if you +pick any gene from here say + + align:start position:0% +pick any gene from here say + + + align:start position:0% +pick any gene from here say +and you plot its profile how does it + + align:start position:0% +and you plot its profile how does it + + + align:start position:0% +and you plot its profile how does it +look like it turns out that the profile + + align:start position:0% +look like it turns out that the profile + + + align:start position:0% +look like it turns out that the profile +looks like that + + align:start position:0% +looks like that + + + align:start position:0% +looks like that +so what does what + + align:start position:0% +so what does what + + + align:start position:0% +so what does what +in english essentially it is a a gene or + + align:start position:0% +in english essentially it is a a gene or + + + align:start position:0% +in english essentially it is a a gene or +a protein which is highly expressed + + align:start position:0% +a protein which is highly expressed + + + align:start position:0% +a protein which is highly expressed +early on + + align:start position:0% +early on + + + align:start position:0% +early on +and it goes down later on + + align:start position:0% +and it goes down later on + + + align:start position:0% +and it goes down later on +okay what about you pick something here + + align:start position:0% +okay what about you pick something here + + + align:start position:0% +okay what about you pick something here +from the complete opposite end of pc1 + + align:start position:0% +from the complete opposite end of pc1 + + + align:start position:0% +from the complete opposite end of pc1 +that's the shape that you get + + align:start position:0% +that's the shape that you get + + + align:start position:0% +that's the shape that you get +it goes the opposite direction in fact + + align:start position:0% +it goes the opposite direction in fact + + + align:start position:0% +it goes the opposite direction in fact +if you um + + align:start position:0% +if you um + + + align:start position:0% +if you um +pitch samples going all the way from + + align:start position:0% +pitch samples going all the way from + + + align:start position:0% +pitch samples going all the way from +here to there you will notice that there + + align:start position:0% +here to there you will notice that there + + + align:start position:0% +here to there you will notice that there +is a gradual shifting of this shape to + + align:start position:0% +is a gradual shifting of this shape to + + + align:start position:0% +is a gradual shifting of this shape to +that it morphs one into the other + + align:start position:0% +that it morphs one into the other + + + align:start position:0% +that it morphs one into the other +okay and so this is an example of + + align:start position:0% +okay and so this is an example of + + + align:start position:0% +okay and so this is an example of +something picked out of the 90 degrees + + align:start position:0% +something picked out of the 90 degrees + + + align:start position:0% +something picked out of the 90 degrees +counting from 12 o'clock that's how it + + align:start position:0% +counting from 12 o'clock that's how it + + + align:start position:0% +counting from 12 o'clock that's how it +looks like so it's a very convenient way + + align:start position:0% +looks like so it's a very convenient way + + + align:start position:0% +looks like so it's a very convenient way +to display everything and another + + align:start position:0% +to display everything and another + + + align:start position:0% +to display everything and another +utility is the density of dots you + + align:start position:0% +utility is the density of dots you + + + align:start position:0% +utility is the density of dots you +notice that there is a huge absence of + + align:start position:0% +notice that there is a huge absence of + + + align:start position:0% +notice that there is a huge absence of +anything here right so basically you + + align:start position:0% +anything here right so basically you + + + align:start position:0% +anything here right so basically you +could say you could claim that + + align:start position:0% +could say you could claim that + + + align:start position:0% +could say you could claim that +there there is a + + align:start position:0% +there there is a + + + align:start position:0% +there there is a +there is a family of profiles that is + + align:start position:0% +there is a family of profiles that is + + + align:start position:0% +there is a family of profiles that is +actually missing + + align:start position:0% +actually missing + + + align:start position:0% +actually missing +from all these genes a lot of + + align:start position:0% +from all these genes a lot of + + + align:start position:0% +from all these genes a lot of +not no genes at all express a + + align:start position:0% +not no genes at all express a + + + align:start position:0% +not no genes at all express a +theoretical profile here i think it is + + align:start position:0% +theoretical profile here i think it is + + + align:start position:0% +theoretical profile here i think it is +something which looks like that but with + + align:start position:0% +something which looks like that but with + + + align:start position:0% +something which looks like that but with +some variation + + align:start position:0% +some variation + + + align:start position:0% +some variation +so but mo there is a density here i'm + + align:start position:0% +so but mo there is a density here i'm + + + align:start position:0% +so but mo there is a density here i'm +not sure how that looks like + + align:start position:0% +not sure how that looks like + + + align:start position:0% +not sure how that looks like +so it's a convenient way to display + + align:start position:0% +so it's a convenient way to display + + + align:start position:0% +so it's a convenient way to display +everything or + + align:start position:0% +everything or + + + align:start position:0% +everything or +as opposed to watch as opposed to seeing + + align:start position:0% +as opposed to watch as opposed to seeing + + + align:start position:0% +as opposed to watch as opposed to seeing +10 000 of these things + + align:start position:0% + + + + align:start position:0% + +so it's like a dictionary + + align:start position:0% + + + + align:start position:0% + +the so that was looking at genes sitting + + align:start position:0% +the so that was looking at genes sitting + + + align:start position:0% +the so that was looking at genes sitting +in time space the other transpose way of + + align:start position:0% +in time space the other transpose way of + + + align:start position:0% +in time space the other transpose way of +looking at the same system the same data + + align:start position:0% +looking at the same system the same data + + + align:start position:0% +looking at the same system the same data +is to view it as samples time points + + align:start position:0% +is to view it as samples time points + + + align:start position:0% +is to view it as samples time points +i've labeled them one through oh + + align:start position:0% +i've labeled them one through oh + + + align:start position:0% +i've labeled them one through oh +actually it's 13 1 through 13 + + align:start position:0% +actually it's 13 1 through 13 + + + align:start position:0% +actually it's 13 1 through 13 +sitting in a genomic space of 10 + + align:start position:0% +sitting in a genomic space of 10 + + + align:start position:0% +sitting in a genomic space of 10 +thousand dimensions okay + + align:start position:0% +thousand dimensions okay + + + align:start position:0% +thousand dimensions okay +if you just picked any three genes at + + align:start position:0% +if you just picked any three genes at + + + align:start position:0% +if you just picked any three genes at +random + + align:start position:0% +random + + + align:start position:0% +random +and plotted these samples + + align:start position:0% +and plotted these samples + + + align:start position:0% +and plotted these samples +okay um the numbers one through thirteen + + align:start position:0% +okay um the numbers one through thirteen + + + align:start position:0% +okay um the numbers one through thirteen +are consecutive i didn't just randomly + + align:start position:0% +are consecutive i didn't just randomly + + + align:start position:0% +are consecutive i didn't just randomly +assign them they're consecutive with + + align:start position:0% +assign them they're consecutive with + + + align:start position:0% +assign them they're consecutive with +time so time 13 is going to be greater + + align:start position:0% +time so time 13 is going to be greater + + + align:start position:0% +time so time 13 is going to be greater +than time 12 greater than time 11 etc + + align:start position:0% +than time 12 greater than time 11 etc + + + align:start position:0% +than time 12 greater than time 11 etc +etc + + align:start position:0% +etc + + + align:start position:0% +etc +so you picked any two genes + + align:start position:0% +so you picked any two genes + + + align:start position:0% +so you picked any two genes +and what do you notice + + align:start position:0% +and what do you notice + + + align:start position:0% +and what do you notice +well you know there's nothing it's just + + align:start position:0% +well you know there's nothing it's just + + + align:start position:0% +well you know there's nothing it's just +a mess + + align:start position:0% +a mess + + + align:start position:0% +a mess +okay + + align:start position:0% +okay + + + align:start position:0% +okay +you pick any three and i'm just speaking + + align:start position:0% +you pick any three and i'm just speaking + + + align:start position:0% +you pick any three and i'm just speaking +three for example i mean you'd be very + + align:start position:0% +three for example i mean you'd be very + + + align:start position:0% +three for example i mean you'd be very +lucky if you pick a + + align:start position:0% +lucky if you pick a + + + align:start position:0% +lucky if you pick a +a set of three that actually reveal some + + align:start position:0% +a set of three that actually reveal some + + + align:start position:0% +a set of three that actually reveal some +beautiful structure in here but then + + align:start position:0% +beautiful structure in here but then + + + align:start position:0% +beautiful structure in here but then +then you have to wonder if what is what + + align:start position:0% +then you have to wonder if what is what + + + align:start position:0% +then you have to wonder if what is what +is a noise here right this goes back to + + align:start position:0% +is a noise here right this goes back to + + + align:start position:0% +is a noise here right this goes back to +understanding what is the underlying + + align:start position:0% +understanding what is the underlying + + + align:start position:0% +understanding what is the underlying +null hypothesis of the system + + align:start position:0% +null hypothesis of the system + + + align:start position:0% +null hypothesis of the system +so now you perform uh principle + + align:start position:0% +so now you perform uh principle + + + align:start position:0% +so now you perform uh principle +component analysis + + align:start position:0% +component analysis + + + align:start position:0% +component analysis +what happens + + align:start position:0% +what happens + + + align:start position:0% +what happens +the the the first principle + + align:start position:0% +the the the first principle + + + align:start position:0% +the the the first principle +component second and third right + + align:start position:0% +component second and third right + + + align:start position:0% +component second and third right +the most salient thing that jumps out at + + align:start position:0% +the most salient thing that jumps out at + + + align:start position:0% +the most salient thing that jumps out at +you is that pc one looks + + align:start position:0% +you is that pc one looks + + + align:start position:0% +you is that pc one looks +looks to be um + + align:start position:0% +looks to be um + + + align:start position:0% +looks to be um +um + + align:start position:0% +um + + + align:start position:0% +um +correlated with time + + align:start position:0% +correlated with time + + + align:start position:0% +correlated with time +you get one two three four five six + + align:start position:0% +you get one two three four five six + + + align:start position:0% +you get one two three four five six +seven well twelve is an anomaly i don't + + align:start position:0% +seven well twelve is an anomaly i don't + + + align:start position:0% +seven well twelve is an anomaly i don't +know why it landed there + + align:start position:0% +know why it landed there + + + align:start position:0% +know why it landed there +and thirteen + + align:start position:0% +and thirteen + + + align:start position:0% +and thirteen +okay so i'm not sure what the other + + align:start position:0% +okay so i'm not sure what the other + + + align:start position:0% +okay so i'm not sure what the other +principle components mean + + align:start position:0% +principle components mean + + + align:start position:0% +principle components mean +maybe there is some biologic import to + + align:start position:0% +maybe there is some biologic import to + + + align:start position:0% +maybe there is some biologic import to +them it's unclear to me but + + align:start position:0% +them it's unclear to me but + + + align:start position:0% +them it's unclear to me but +certainly + + align:start position:0% +certainly + + + align:start position:0% +certainly +one captures the progression of time it + + align:start position:0% +one captures the progression of time it + + + align:start position:0% +one captures the progression of time it +looks to me and you are sort of immune + + align:start position:0% +looks to me and you are sort of immune + + + align:start position:0% +looks to me and you are sort of immune +from um + + align:start position:0% + + + + align:start position:0% + +from + + align:start position:0% +from + + + align:start position:0% +from +the possibility that this is actually + + align:start position:0% +the possibility that this is actually + + + align:start position:0% +the possibility that this is actually +due to noise why because + + align:start position:0% +due to noise why because + + + align:start position:0% +due to noise why because +a principal component now it's not just + + align:start position:0% +a principal component now it's not just + + + align:start position:0% +a principal component now it's not just +a single gene or two it's actually a + + align:start position:0% +a single gene or two it's actually a + + + align:start position:0% +a single gene or two it's actually a +linear combination of something at ten + + align:start position:0% +linear combination of something at ten + + + align:start position:0% +linear combination of something at ten +thousand + + align:start position:0% +thousand + + + align:start position:0% +thousand +so + + align:start position:0% +so + + + align:start position:0% +so +that's the power of the method have you + + align:start position:0% +that's the power of the method have you + + + align:start position:0% +that's the power of the method have you +just picked any three randomly and found + + align:start position:0% +just picked any three randomly and found + + + align:start position:0% +just picked any three randomly and found +a configuration like this you have to + + align:start position:0% +a configuration like this you have to + + + align:start position:0% +a configuration like this you have to +wonder the randomness of this thing + + align:start position:0% +wonder the randomness of this thing + + + align:start position:0% +wonder the randomness of this thing +happening but this isn't this is a + + align:start position:0% +happening but this isn't this is a + + + align:start position:0% +happening but this isn't this is a +linear combination of all of them that + + align:start position:0% +linear combination of all of them that + + + align:start position:0% +linear combination of all of them that +is the power of this methodology + + align:start position:0% +is the power of this methodology + + + align:start position:0% +is the power of this methodology +um + + align:start position:0% + + + + align:start position:0% + +i give you another example but this is + + align:start position:0% +i give you another example but this is + + + align:start position:0% +i give you another example but this is +very kindergarten so + + align:start position:0% +very kindergarten so + + + align:start position:0% +very kindergarten so +um + + align:start position:0% +um + + + align:start position:0% +um +fourier decomposition fourier transforms + + align:start position:0% +fourier decomposition fourier transforms + + + align:start position:0% +fourier decomposition fourier transforms +that is another way of + + align:start position:0% +that is another way of + + + align:start position:0% +that is another way of +representing transforming data to reveal + + align:start position:0% +representing transforming data to reveal + + + align:start position:0% +representing transforming data to reveal +structures within the data and the point + + align:start position:0% +structures within the data and the point + + + align:start position:0% +structures within the data and the point +of doing fourier analysis is you want to + + align:start position:0% +of doing fourier analysis is you want to + + + align:start position:0% +of doing fourier analysis is you want to +reveal + + align:start position:0% +reveal + + + align:start position:0% +reveal +um + + align:start position:0% +um + + + align:start position:0% +um +the objects that you're looking for are + + align:start position:0% +the objects that you're looking for are + + + align:start position:0% +the objects that you're looking for are +basically frequencies + + align:start position:0% +basically frequencies + + + align:start position:0% +basically frequencies +right so let's say that you have uh + + align:start position:0% +right so let's say that you have uh + + + align:start position:0% +right so let's say that you have uh +this is not real world data of course it + + align:start position:0% +this is not real world data of course it + + + align:start position:0% +this is not real world data of course it +was completely cooked out of a machine + + align:start position:0% +was completely cooked out of a machine + + + align:start position:0% +was completely cooked out of a machine +if you have this red sinusoid here + + align:start position:0% +if you have this red sinusoid here + + + align:start position:0% +if you have this red sinusoid here +right of a period one + + align:start position:0% +right of a period one + + + align:start position:0% +right of a period one +and you + + align:start position:0% +and you + + + align:start position:0% +and you +clearly the frequency is just one + + align:start position:0% +clearly the frequency is just one + + + align:start position:0% +clearly the frequency is just one +frequency right it's uh i don't know if + + align:start position:0% +frequency right it's uh i don't know if + + + align:start position:0% +frequency right it's uh i don't know if +sequence is something one over two pi or + + align:start position:0% +sequence is something one over two pi or + + + align:start position:0% +sequence is something one over two pi or +what not + + align:start position:0% +what not + + + align:start position:0% +what not +when you + + align:start position:0% +when you + + + align:start position:0% +when you +apply fourier transforms on it well + + align:start position:0% +apply fourier transforms on it well + + + align:start position:0% +apply fourier transforms on it well +discrete + + align:start position:0% +discrete + + + align:start position:0% +discrete +fast fourier transform + + align:start position:0% +fast fourier transform + + + align:start position:0% +fast fourier transform +you will find uh um + + align:start position:0% +you will find uh um + + + align:start position:0% +you will find uh um +you enter the realm of complex numbers + + align:start position:0% +you enter the realm of complex numbers + + + align:start position:0% +you enter the realm of complex numbers +actually but it's suffice to know + + align:start position:0% +actually but it's suffice to know + + + align:start position:0% +actually but it's suffice to know +that + + align:start position:0% +that + + + align:start position:0% +that +you get a point + + align:start position:0% +you get a point + + + align:start position:0% +you get a point +in frequency space + + align:start position:0% +in frequency space + + + align:start position:0% +in frequency space +that's the point + + align:start position:0% +that's the point + + + align:start position:0% +that's the point +and to give you some bearing let's take + + align:start position:0% +and to give you some bearing let's take + + + align:start position:0% +and to give you some bearing let's take +another waveform + + align:start position:0% +another waveform + + + align:start position:0% +another waveform +which is twice the frequency + + align:start position:0% +which is twice the frequency + + + align:start position:0% +which is twice the frequency +that frequency shouldn't be surprising + + align:start position:0% +that frequency shouldn't be surprising + + + align:start position:0% +that frequency shouldn't be surprising +that it's actually twice it's 5 2.5 + + align:start position:0% +that it's actually twice it's 5 2.5 + + + align:start position:0% +that it's actually twice it's 5 2.5 +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and now you take yet another waveform + + align:start position:0% +and now you take yet another waveform + + + align:start position:0% +and now you take yet another waveform +which is even faster + + align:start position:0% +which is even faster + + + align:start position:0% +which is even faster +that's the uh + + align:start position:0% +that's the uh + + + align:start position:0% +that's the uh +so the mapping so this entire waveform + + align:start position:0% +so the mapping so this entire waveform + + + align:start position:0% +so the mapping so this entire waveform +maps to just one point one point one + + align:start position:0% +maps to just one point one point one + + + align:start position:0% +maps to just one point one point one +point + + align:start position:0% +point + + + align:start position:0% +point +right so the object of interest here + + align:start position:0% +right so the object of interest here + + + align:start position:0% +right so the object of interest here +frequencies + + align:start position:0% +frequencies + + + align:start position:0% +frequencies +it's not localized in time for + + align:start position:0% +it's not localized in time for + + + align:start position:0% +it's not localized in time for +localization you the + + align:start position:0% +localization you the + + + align:start position:0% +localization you the +transformation techniques such as uh + + align:start position:0% +transformation techniques such as uh + + + align:start position:0% +transformation techniques such as uh +wavelets + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +of course the world does not give you + + align:start position:0% +of course the world does not give you + + + align:start position:0% +of course the world does not give you +data so nicely in this uniform band + + align:start position:0% +data so nicely in this uniform band + + + align:start position:0% +data so nicely in this uniform band +limited three signals like this right + + align:start position:0% +limited three signals like this right + + + align:start position:0% +limited three signals like this right +so let's suppose that the world + + align:start position:0% + + + + align:start position:0% + +makes it more complicated + + align:start position:0% +makes it more complicated + + + align:start position:0% +makes it more complicated +adds up these three sinusoids when you + + align:start position:0% +adds up these three sinusoids when you + + + align:start position:0% +adds up these three sinusoids when you +add up these three sinusoids what + + align:start position:0% +add up these three sinusoids what + + + align:start position:0% +add up these three sinusoids what +happens + + align:start position:0% +happens + + + align:start position:0% +happens +this is what you see + + align:start position:0% +this is what you see + + + align:start position:0% +this is what you see +okay now let's say the world presents + + align:start position:0% +okay now let's say the world presents + + + align:start position:0% +okay now let's say the world presents +you with this + + align:start position:0% +you with this + + + align:start position:0% +you with this +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +there are many things you can do you can + + align:start position:0% +there are many things you can do you can + + + align:start position:0% +there are many things you can do you can +actually do principle component analysis + + align:start position:0% +actually do principle component analysis + + + align:start position:0% +actually do principle component analysis +but the question is what are you trying + + align:start position:0% +but the question is what are you trying + + + align:start position:0% +but the question is what are you trying +to look for if you are looking for the + + align:start position:0% +to look for if you are looking for the + + + align:start position:0% +to look for if you are looking for the +predominant frequencies + + align:start position:0% +predominant frequencies + + + align:start position:0% +predominant frequencies +embedded in this waveform the most + + align:start position:0% +embedded in this waveform the most + + + align:start position:0% +embedded in this waveform the most +natural thing to do is for your analysis + + align:start position:0% +natural thing to do is for your analysis + + + align:start position:0% +natural thing to do is for your analysis +and when you do for your analysis it + + align:start position:0% +and when you do for your analysis it + + + align:start position:0% +and when you do for your analysis it +should not shock you + + align:start position:0% +should not shock you + + + align:start position:0% +should not shock you +that the answer when you + + align:start position:0% +that the answer when you + + + align:start position:0% +that the answer when you +you know map it to frequency space is + + align:start position:0% +you know map it to frequency space is + + + align:start position:0% +you know map it to frequency space is +three dots + + align:start position:0% +three dots + + + align:start position:0% +three dots +happens to be the same three dots out + + align:start position:0% +happens to be the same three dots out + + + align:start position:0% +happens to be the same three dots out +there + + align:start position:0% +there + + + align:start position:0% +there +so that's yeah + + align:start position:0% +so that's yeah + + + align:start position:0% +so that's yeah +that's the beauty of it and there are + + align:start position:0% +that's the beauty of it and there are + + + align:start position:0% +that's the beauty of it and there are +applications very real applications + + align:start position:0% +applications very real applications + + + align:start position:0% +applications very real applications +actually when it comes when you um + + align:start position:0% +actually when it comes when you um + + + align:start position:0% +actually when it comes when you um +enter into sequential dynamic uh um and + + align:start position:0% +enter into sequential dynamic uh um and + + + align:start position:0% +enter into sequential dynamic uh um and +sequential genomics because the + + align:start position:0% +sequential genomics because the + + + align:start position:0% +sequential genomics because the +alphabets atcg can easily be mapped into + + align:start position:0% +alphabets atcg can easily be mapped into + + + align:start position:0% +alphabets atcg can easily be mapped into +zero one two three + + align:start position:0% +zero one two three + + + align:start position:0% +zero one two three +of course um the ordering i'm not quite + + align:start position:0% +of course um the ordering i'm not quite + + + align:start position:0% +of course um the ordering i'm not quite +sure if the ordering actually matters + + align:start position:0% +sure if the ordering actually matters + + + align:start position:0% +sure if the ordering actually matters +the ordinality + + align:start position:0% +the ordinality + + + align:start position:0% +the ordinality +but i don't think it does and if you are + + align:start position:0% +but i don't think it does and if you are + + + align:start position:0% +but i don't think it does and if you are +interested in uh + + align:start position:0% + + + + align:start position:0% + +repeating structures in the genome + + align:start position:0% +repeating structures in the genome + + + align:start position:0% +repeating structures in the genome +it could be helpful i'm sure people have + + align:start position:0% +it could be helpful i'm sure people have + + + align:start position:0% +it could be helpful i'm sure people have +done this in fact + + align:start position:0% +done this in fact + + + align:start position:0% +done this in fact +so the summary of data transformation is + + align:start position:0% +so the summary of data transformation is + + + align:start position:0% +so the summary of data transformation is +basically somebody gives you um + + align:start position:0% +basically somebody gives you um + + + align:start position:0% +basically somebody gives you um +a vector x + + align:start position:0% +a vector x + + + align:start position:0% +a vector x +data x + + align:start position:0% +data x + + + align:start position:0% +data x +and you simply rewrite it + + align:start position:0% +and you simply rewrite it + + + align:start position:0% +and you simply rewrite it +into a a different form + + align:start position:0% +into a a different form + + + align:start position:0% +into a a different form +based on a + + align:start position:0% + + + + align:start position:0% + +a set of basis elements they are + + align:start position:0% +a set of basis elements they are + + + align:start position:0% +a set of basis elements they are +different from the original ones how do + + align:start position:0% +different from the original ones how do + + + align:start position:0% +different from the original ones how do +i say typically when somebody gives you + + align:start position:0% +i say typically when somebody gives you + + + align:start position:0% +i say typically when somebody gives you +data all right there's going to be real + + align:start position:0% +data all right there's going to be real + + + align:start position:0% +data all right there's going to be real +numbers and let's say a matrix and the + + align:start position:0% +numbers and let's say a matrix and the + + + align:start position:0% +numbers and let's say a matrix and the +the standard basis is the basis they're + + align:start position:0% +the standard basis is the basis they're + + + align:start position:0% +the standard basis is the basis they're +thinking of now 1 0 0 0 0 1 0 etc what + + align:start position:0% +thinking of now 1 0 0 0 0 1 0 etc what + + + align:start position:0% +thinking of now 1 0 0 0 0 1 0 etc what +you can do is actually you know + + align:start position:0% +you can do is actually you know + + + align:start position:0% +you can do is actually you know +transform it by principal component + + align:start position:0% +transform it by principal component + + + align:start position:0% +transform it by principal component +analysis of fourier transforms or even + + align:start position:0% +analysis of fourier transforms or even + + + align:start position:0% +analysis of fourier transforms or even +wavelets + + align:start position:0% +wavelets + + + align:start position:0% +wavelets +all these techniques + + align:start position:0% +all these techniques + + + align:start position:0% +all these techniques +are simply + + align:start position:0% +are simply + + + align:start position:0% +are simply +names to describe these basis elements + + align:start position:0% +names to describe these basis elements + + + align:start position:0% +names to describe these basis elements +the actual + + align:start position:0% +the actual + + + align:start position:0% +the actual +new representation forms are come out by + + align:start position:0% +new representation forms are come out by + + + align:start position:0% +new representation forms are come out by +um in these a subject + + align:start position:0% +um in these a subject + + + align:start position:0% +um in these a subject +okay you can actually read about this in + + align:start position:0% +okay you can actually read about this in + + + align:start position:0% +okay you can actually read about this in +in several textbooks say um do the heart + + align:start position:0% +in several textbooks say um do the heart + + + align:start position:0% +in several textbooks say um do the heart +and pattern recognition which i shall + + align:start position:0% +and pattern recognition which i shall + + + align:start position:0% +and pattern recognition which i shall +provide + + align:start position:0% +provide + + + align:start position:0% +provide +at the um + + align:start position:0% +at the um + + + align:start position:0% +at the um +in a + + align:start position:0% +in a + + + align:start position:0% +in a +leaflet handout + + align:start position:0% +leaflet handout + + + align:start position:0% +leaflet handout +um + + align:start position:0% +um + + + align:start position:0% +um +and and clearly not all these uh + + align:start position:0% +and and clearly not all these uh + + + align:start position:0% +and and clearly not all these uh +transformation techniques are equal they + + align:start position:0% +transformation techniques are equal they + + + align:start position:0% +transformation techniques are equal they +are going to reveal for you very + + align:start position:0% +are going to reveal for you very + + + align:start position:0% +are going to reveal for you very +different things or very different + + align:start position:0% +different things or very different + + + align:start position:0% +different things or very different +internal structures in the data that + + align:start position:0% +internal structures in the data that + + + align:start position:0% +internal structures in the data that +that should be obvious + + align:start position:0% + + + + align:start position:0% + +and there is i claim that there is + + align:start position:0% +and there is i claim that there is + + + align:start position:0% +and there is i claim that there is +almost always a geometric interpretation + + align:start position:0% +almost always a geometric interpretation + + + align:start position:0% +almost always a geometric interpretation +of any given data set + + align:start position:0% +of any given data set + + + align:start position:0% +of any given data set +okay + + align:start position:0% +okay + + + align:start position:0% +okay +secondary uses would be a denoising and + + align:start position:0% +secondary uses would be a denoising and + + + align:start position:0% +secondary uses would be a denoising and +feature reduction we have seen actually + + align:start position:0% +feature reduction we have seen actually + + + align:start position:0% +feature reduction we have seen actually +in the case of pca the annoying thing is + + align:start position:0% +in the case of pca the annoying thing is + + + align:start position:0% +in the case of pca the annoying thing is +say fourier transforms + + align:start position:0% +say fourier transforms + + + align:start position:0% +say fourier transforms +you could you could if you believe that + + align:start position:0% +you could you could if you believe that + + + align:start position:0% +you could you could if you believe that +noise are higher frequencies you could + + align:start position:0% +noise are higher frequencies you could + + + align:start position:0% +noise are higher frequencies you could +band limit or you could mod out all the + + align:start position:0% +band limit or you could mod out all the + + + align:start position:0% +band limit or you could mod out all the +um dots which appear much higher in that + + align:start position:0% +um dots which appear much higher in that + + + align:start position:0% +um dots which appear much higher in that +frequency space + + align:start position:0% + + + + align:start position:0% + +um really i don't think i'll talk about + + align:start position:0% +um really i don't think i'll talk about + + + align:start position:0% +um really i don't think i'll talk about +this now + + align:start position:0% +this now + + + align:start position:0% +this now +do we actually have time for um for + + align:start position:0% +do we actually have time for um for + + + align:start position:0% +do we actually have time for um for +the next part we do + + align:start position:0% +the next part we do + + + align:start position:0% +the next part we do +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now that we are done with data + + align:start position:0% +now that we are done with data + + + align:start position:0% +now that we are done with data +representation i'm going to try to cover + + align:start position:0% +representation i'm going to try to cover + + + align:start position:0% +representation i'm going to try to cover +some + + align:start position:0% +some + + + align:start position:0% +some +common terms that occurs over and over + + align:start position:0% +common terms that occurs over and over + + + align:start position:0% +common terms that occurs over and over +again in + + align:start position:0% +again in + + + align:start position:0% +again in +the area of microarray analysis or + + align:start position:0% +the area of microarray analysis or + + + align:start position:0% +the area of microarray analysis or +genomics okay you hear it all the time + + align:start position:0% +genomics okay you hear it all the time + + + align:start position:0% +genomics okay you hear it all the time +but you wonder what they mean + + align:start position:0% +but you wonder what they mean + + + align:start position:0% +but you wonder what they mean +i sometimes wonder what they mean + + align:start position:0% +i sometimes wonder what they mean + + + align:start position:0% +i sometimes wonder what they mean +but this is my understanding at least + + align:start position:0% +but this is my understanding at least + + + align:start position:0% +but this is my understanding at least +what they mean + + align:start position:0% +what they mean + + + align:start position:0% +what they mean +a very important thing i believe as as + + align:start position:0% +a very important thing i believe as as + + + align:start position:0% +a very important thing i believe as as +to a lot of people i'm sure is that + + align:start position:0% +to a lot of people i'm sure is that + + + align:start position:0% +to a lot of people i'm sure is that +nature makes no leaps + + align:start position:0% +nature makes no leaps + + + align:start position:0% +nature makes no leaps +okay that physical phenomenon at least + + align:start position:0% +okay that physical phenomenon at least + + + align:start position:0% +okay that physical phenomenon at least +at the macroscopic level what you + + align:start position:0% +at the macroscopic level what you + + + align:start position:0% +at the macroscopic level what you +observe not microscopic + + align:start position:0% +observe not microscopic + + + align:start position:0% +observe not microscopic +atoms bumping around at least at a + + align:start position:0% +atoms bumping around at least at a + + + align:start position:0% +atoms bumping around at least at a +microscopic level + + align:start position:0% +microscopic level + + + align:start position:0% +microscopic level +it cannot occur abruptly there has to be + + align:start position:0% +it cannot occur abruptly there has to be + + + align:start position:0% +it cannot occur abruptly there has to be +a continuity to these processes and this + + align:start position:0% +a continuity to these processes and this + + + align:start position:0% +a continuity to these processes and this +is a very important guiding principle at + + align:start position:0% +is a very important guiding principle at + + + align:start position:0% +is a very important guiding principle at +least + + align:start position:0% +least + + + align:start position:0% +least +in + + align:start position:0% +in + + + align:start position:0% +in +definition of noise + + align:start position:0% +definition of noise + + + align:start position:0% +definition of noise +okay so i'll give you an example i don't + + align:start position:0% +okay so i'll give you an example i don't + + + align:start position:0% +okay so i'll give you an example i don't +know what i call example four + + align:start position:0% +know what i call example four + + + align:start position:0% +know what i call example four +i make a hundred separate measurements + + align:start position:0% +i make a hundred separate measurements + + + align:start position:0% +i make a hundred separate measurements +at the room temperature in this room + + align:start position:0% +at the room temperature in this room + + + align:start position:0% +at the room temperature in this room +in a one minute interval at different + + align:start position:0% +in a one minute interval at different + + + align:start position:0% +in a one minute interval at different +locations + + align:start position:0% +locations + + + align:start position:0% +locations +depending on the accuracy of the device + + align:start position:0% +depending on the accuracy of the device + + + align:start position:0% +depending on the accuracy of the device +i'm using it is not very likely that all + + align:start position:0% +i'm using it is not very likely that all + + + align:start position:0% +i'm using it is not very likely that all +these measurements are going to be the + + align:start position:0% +these measurements are going to be the + + + align:start position:0% +these measurements are going to be the +same + + align:start position:0% +same + + + align:start position:0% +same +okay so the question is + + align:start position:0% +okay so the question is + + + align:start position:0% +okay so the question is +um + + align:start position:0% +um + + + align:start position:0% +um +and it is a ill-posed question what is + + align:start position:0% +and it is a ill-posed question what is + + + align:start position:0% +and it is a ill-posed question what is +the temperature in this room on average + + align:start position:0% +the temperature in this room on average + + + align:start position:0% +the temperature in this room on average +or what is the temperature distribution + + align:start position:0% +or what is the temperature distribution + + + align:start position:0% +or what is the temperature distribution +in this room + + align:start position:0% +in this room + + + align:start position:0% +in this room +questions like this + + align:start position:0% +questions like this + + + align:start position:0% +questions like this +now + + align:start position:0% +now + + + align:start position:0% +now +i + + align:start position:0% +i + + + align:start position:0% +i +this is my working definition of noise + + align:start position:0% +this is my working definition of noise + + + align:start position:0% +this is my working definition of noise +and i'm sure that there are going to be + + align:start position:0% +and i'm sure that there are going to be + + + align:start position:0% +and i'm sure that there are going to be +it can be argued + + align:start position:0% +it can be argued + + + align:start position:0% +it can be argued +in a narrow sense noise is any + + align:start position:0% +in a narrow sense noise is any + + + align:start position:0% +in a narrow sense noise is any +measurable divergence from axiom one + + align:start position:0% +measurable divergence from axiom one + + + align:start position:0% +measurable divergence from axiom one +this idea or more generally any + + align:start position:0% +this idea or more generally any + + + align:start position:0% +this idea or more generally any +applicable axiom + + align:start position:0% +applicable axiom + + + align:start position:0% +applicable axiom +in a studied system + + align:start position:0% +in a studied system + + + align:start position:0% +in a studied system +okay so if you believe that as if you + + align:start position:0% +okay so if you believe that as if you + + + align:start position:0% +okay so if you believe that as if you +are very very sure + + align:start position:0% +are very very sure + + + align:start position:0% +are very very sure +that the room temperature + + align:start position:0% +that the room temperature + + + align:start position:0% +that the room temperature +example if you believe that the room + + align:start position:0% +example if you believe that the room + + + align:start position:0% +example if you believe that the room +temperature in this room + + align:start position:0% +temperature in this room + + + align:start position:0% +temperature in this room +cannot be so different from me from here + + align:start position:0% +cannot be so different from me from here + + + align:start position:0% +cannot be so different from me from here +to there + + align:start position:0% +to there + + + align:start position:0% +to there +then you make 100 measurements okay + + align:start position:0% + + + + align:start position:0% + +any uh and you believe that there is an + + align:start position:0% +any uh and you believe that there is an + + + align:start position:0% +any uh and you believe that there is an +idealized temperature or some belief + + align:start position:0% +idealized temperature or some belief + + + align:start position:0% +idealized temperature or some belief +that there is should be a static + + align:start position:0% +that there is should be a static + + + align:start position:0% +that there is should be a static +quantity + + align:start position:0% +quantity + + + align:start position:0% +quantity +any fluctuation + + align:start position:0% +any fluctuation + + + align:start position:0% +any fluctuation +any fluctuating uh measure + + align:start position:0% +any fluctuating uh measure + + + align:start position:0% +any fluctuating uh measure +observations you made + + align:start position:0% +observations you made + + + align:start position:0% +observations you made +away from this idealized temperature + + align:start position:0% +away from this idealized temperature + + + align:start position:0% +away from this idealized temperature +which you don't know anyways the best + + align:start position:0% +which you don't know anyways the best + + + align:start position:0% +which you don't know anyways the best +you can do is estimate with the average + + align:start position:0% +you can do is estimate with the average + + + align:start position:0% +you can do is estimate with the average +any fluctuation is noise + + align:start position:0% +any fluctuation is noise + + + align:start position:0% +any fluctuation is noise +so + + align:start position:0% +so + + + align:start position:0% +so +it's practical i'm not sure if it's + + align:start position:0% +it's practical i'm not sure if it's + + + align:start position:0% +it's practical i'm not sure if it's +useful at all + + align:start position:0% +useful at all + + + align:start position:0% +useful at all +and in ideal situations uh math theorems + + align:start position:0% +and in ideal situations uh math theorems + + + align:start position:0% +and in ideal situations uh math theorems +will apply things like the central limit + + align:start position:0% +will apply things like the central limit + + + align:start position:0% +will apply things like the central limit +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +and law of large numbers they are very + + align:start position:0% +and law of large numbers they are very + + + align:start position:0% +and law of large numbers they are very +very robust + + align:start position:0% +very robust + + + align:start position:0% +very robust +if you have a lot of + + align:start position:0% +if you have a lot of + + + align:start position:0% +if you have a lot of +the question is + + align:start position:0% +the question is + + + align:start position:0% +the question is +or the problem is that you need to have + + align:start position:0% +or the problem is that you need to have + + + align:start position:0% +or the problem is that you need to have +a lot of observations in order for these + + align:start position:0% +a lot of observations in order for these + + + align:start position:0% +a lot of observations in order for these +to kick in and help you + + align:start position:0% +to kick in and help you + + + align:start position:0% +to kick in and help you +okay + + align:start position:0% + + + + align:start position:0% + +now + + align:start position:0% +now + + + align:start position:0% +now +what is a replica and + + align:start position:0% +what is a replica and + + + align:start position:0% +what is a replica and +repeated measurement and + + align:start position:0% +repeated measurement and + + + align:start position:0% +repeated measurement and +what i'm going to say here is not going + + align:start position:0% +what i'm going to say here is not going + + + align:start position:0% +what i'm going to say here is not going +to be new to you + + align:start position:0% +to be new to you + + + align:start position:0% +to be new to you +how people define replica als it in a + + align:start position:0% +how people define replica als it in a + + + align:start position:0% +how people define replica als it in a +way also depends on + + align:start position:0% +way also depends on + + + align:start position:0% +way also depends on +in fact replicates and reproducibility + + align:start position:0% +in fact replicates and reproducibility + + + align:start position:0% +in fact replicates and reproducibility +uh go hand in hand + + align:start position:0% +uh go hand in hand + + + align:start position:0% +uh go hand in hand +right + + align:start position:0% + + + + align:start position:0% + +i give you three examples of a + + align:start position:0% +i give you three examples of a + + + align:start position:0% +i give you three examples of a +replicate measurement you can when you + + align:start position:0% +replicate measurement you can when you + + + align:start position:0% +replicate measurement you can when you +talk about replica you it always + + align:start position:0% +talk about replica you it always + + + align:start position:0% +talk about replica you it always +involves two things right you have + + align:start position:0% +involves two things right you have + + + align:start position:0% +involves two things right you have +something and it's something to compare + + align:start position:0% +something and it's something to compare + + + align:start position:0% +something and it's something to compare +it with + + align:start position:0% +it with + + + align:start position:0% +it with +so um + + align:start position:0% +so um + + + align:start position:0% +so um +let's say that you want to + + align:start position:0% +let's say that you want to + + + align:start position:0% +let's say that you want to +do replicate essays of mice pancreas no + + align:start position:0% +do replicate essays of mice pancreas no + + + align:start position:0% +do replicate essays of mice pancreas no +more mice pancreas whole pancreas + + align:start position:0% +more mice pancreas whole pancreas + + + align:start position:0% +more mice pancreas whole pancreas +rnases + + align:start position:0% +rnases + + + align:start position:0% +rnases +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and they have been controlled for weight + + align:start position:0% +and they have been controlled for weight + + + align:start position:0% +and they have been controlled for weight +for gender etc + + align:start position:0% +for gender etc + + + align:start position:0% +for gender etc +now there are three different situations + + align:start position:0% +now there are three different situations + + + align:start position:0% +now there are three different situations +or three different ways of defining + + align:start position:0% +or three different ways of defining + + + align:start position:0% +or three different ways of defining +replicas right number one you take the + + align:start position:0% +replicas right number one you take the + + + align:start position:0% +replicas right number one you take the +pancreas from each of these mice they + + align:start position:0% +pancreas from each of these mice they + + + align:start position:0% +pancreas from each of these mice they +are say the same litter + + align:start position:0% +are say the same litter + + + align:start position:0% +are say the same litter +and you you know hybridize it etc + + align:start position:0% +and you you know hybridize it etc + + + align:start position:0% +and you you know hybridize it etc +this could be a definition one of + + align:start position:0% +this could be a definition one of + + + align:start position:0% +this could be a definition one of +replicate + + align:start position:0% +replicate + + + align:start position:0% +replicate +the other is you take the pancreas from + + align:start position:0% +the other is you take the pancreas from + + + align:start position:0% +the other is you take the pancreas from +one mouth + + align:start position:0% +one mouth + + + align:start position:0% +one mouth +and you split it and hybridize it under + + align:start position:0% +and you split it and hybridize it under + + + align:start position:0% +and you split it and hybridize it under +two that's the other one + + align:start position:0% +two that's the other one + + + align:start position:0% +two that's the other one +the notice in this case the biological + + align:start position:0% +the notice in this case the biological + + + align:start position:0% +the notice in this case the biological +variation there is no + + align:start position:0% +variation there is no + + + align:start position:0% +variation there is no +because comes from one here clearly + + align:start position:0% +because comes from one here clearly + + + align:start position:0% +because comes from one here clearly +biological variation is going to be very + + align:start position:0% +biological variation is going to be very + + + align:start position:0% +biological variation is going to be very +important the third one + + align:start position:0% +important the third one + + + align:start position:0% +important the third one +is um + + align:start position:0% +is um + + + align:start position:0% +is um +to somehow + + align:start position:0% +to somehow + + + align:start position:0% +to somehow +homogenize + + align:start position:0% +homogenize + + + align:start position:0% +homogenize +the biological variation at the very top + + align:start position:0% +the biological variation at the very top + + + align:start position:0% +the biological variation at the very top +level you just mix them all up and + + align:start position:0% +level you just mix them all up and + + + align:start position:0% +level you just mix them all up and +split them okay and there are arguments + + align:start position:0% +split them okay and there are arguments + + + align:start position:0% +split them okay and there are arguments +for using this way this way this way + + align:start position:0% +for using this way this way this way + + + align:start position:0% +for using this way this way this way +what you want to control + + align:start position:0% +what you want to control + + + align:start position:0% +what you want to control +it can also be argued that + + align:start position:0% +it can also be argued that + + + align:start position:0% +it can also be argued that +you can remove biological variation but + + align:start position:0% +you can remove biological variation but + + + align:start position:0% +you can remove biological variation but +only at a later stage when you have the + + align:start position:0% +only at a later stage when you have the + + + align:start position:0% +only at a later stage when you have the +numbers + + align:start position:0% +numbers + + + align:start position:0% +numbers +okay + + align:start position:0% +okay + + + align:start position:0% +okay +whereas you are pulling them here you + + align:start position:0% +whereas you are pulling them here you + + + align:start position:0% +whereas you are pulling them here you +can pull them later on + + align:start position:0% +can pull them later on + + + align:start position:0% +can pull them later on +um there is no better or worse + + align:start position:0% +um there is no better or worse + + + align:start position:0% +um there is no better or worse +definition of a replica but one should + + align:start position:0% +definition of a replica but one should + + + align:start position:0% +definition of a replica but one should +be aware when you're reading papers you + + align:start position:0% +be aware when you're reading papers you + + + align:start position:0% +be aware when you're reading papers you +should be aware at least what do they + + align:start position:0% +should be aware at least what do they + + + align:start position:0% +should be aware at least what do they +mean by replicate + + align:start position:0% +mean by replicate + + + align:start position:0% +mean by replicate +okay + + align:start position:0% + + + + align:start position:0% + +because you know in a way um + + align:start position:0% +because you know in a way um + + + align:start position:0% +because you know in a way um +you will also notice that + + align:start position:0% +you will also notice that + + + align:start position:0% +you will also notice that +replica + + align:start position:0% +replica + + + align:start position:0% +replica +the notion of a replica would actually + + align:start position:0% +the notion of a replica would actually + + + align:start position:0% +the notion of a replica would actually +um + + align:start position:0% +um + + + align:start position:0% +um +guide or + + align:start position:0% +guide or + + + align:start position:0% +guide or +affect how you define noise + + align:start position:0% +affect how you define noise + + + align:start position:0% +affect how you define noise +because if you believe that these two + + align:start position:0% +because if you believe that these two + + + align:start position:0% +because if you believe that these two +might give you identical reading + + align:start position:0% +might give you identical reading + + + align:start position:0% +might give you identical reading +then any + + align:start position:0% +then any + + + align:start position:0% +then any +any deviation of this mouse on that one + + align:start position:0% +any deviation of this mouse on that one + + + align:start position:0% +any deviation of this mouse on that one +is going to be nice + + align:start position:0% +is going to be nice + + + align:start position:0% +is going to be nice +and that deviations and you know it + + align:start position:0% +and that deviations and you know it + + + align:start position:0% +and that deviations and you know it +thinks very obvious things + + align:start position:0% +thinks very obvious things + + + align:start position:0% +thinks very obvious things +now um + + align:start position:0% +now um + + + align:start position:0% +now um +yeah i should hear this the definition + + align:start position:0% +yeah i should hear this the definition + + + align:start position:0% +yeah i should hear this the definition +of replicate will have implication on + + align:start position:0% +of replicate will have implication on + + + align:start position:0% +of replicate will have implication on +how you define noise + + align:start position:0% +how you define noise + + + align:start position:0% +how you define noise +and there is we talked about this + + align:start position:0% +and there is we talked about this + + + align:start position:0% +and there is we talked about this +biological versus measurement variation + + align:start position:0% +biological versus measurement variation + + + align:start position:0% +biological versus measurement variation +um + + align:start position:0% +um + + + align:start position:0% +um +this being biological variation + + align:start position:0% +this being biological variation + + + align:start position:0% +this being biological variation +this big measurement variation and + + align:start position:0% +this big measurement variation and + + + align:start position:0% +this big measurement variation and +arguably this could be + + align:start position:0% +arguably this could be + + + align:start position:0% +arguably this could be +measurement variation too + + align:start position:0% + + + + align:start position:0% + +however if you're too restrictive in + + align:start position:0% +however if you're too restrictive in + + + align:start position:0% +however if you're too restrictive in +your definition of replica + + align:start position:0% +your definition of replica + + + align:start position:0% +your definition of replica +it could actually um + + align:start position:0% +it could actually um + + + align:start position:0% +it could actually um +hinder the generalizability of your of + + align:start position:0% +hinder the generalizability of your of + + + align:start position:0% +hinder the generalizability of your of +your study you know your study is only + + align:start position:0% +your study you know your study is only + + + align:start position:0% +your study you know your study is only +applicable to mice with + + align:start position:0% +applicable to mice with + + + align:start position:0% +applicable to mice with +a certain + + align:start position:0% +a certain + + + align:start position:0% +a certain +genetic background very very restricted + + align:start position:0% +genetic background very very restricted + + + align:start position:0% +genetic background very very restricted +etc it + + align:start position:0% +etc it + + + align:start position:0% +etc it +you know one has to consider these + + align:start position:0% +you know one has to consider these + + + align:start position:0% +you know one has to consider these +things + + align:start position:0% +things + + + align:start position:0% +things +but despite taking all precautions it is + + align:start position:0% +but despite taking all precautions it is + + + align:start position:0% +but despite taking all precautions it is +not very likely that + + align:start position:0% +not very likely that + + + align:start position:0% +not very likely that +your quote unquote replicate essays + + align:start position:0% +your quote unquote replicate essays + + + align:start position:0% +your quote unquote replicate essays +down the line + + align:start position:0% +down the line + + + align:start position:0% +down the line +gives you numerically identical um + + align:start position:0% +gives you numerically identical um + + + align:start position:0% +gives you numerically identical um +results + + align:start position:0% +results + + + align:start position:0% +results +and there is this old saying i think + + align:start position:0% +and there is this old saying i think + + + align:start position:0% +and there is this old saying i think +from the greek atoms that you never step + + align:start position:0% +from the greek atoms that you never step + + + align:start position:0% +from the greek atoms that you never step +into the same river twice it's very true + + align:start position:0% +into the same river twice it's very true + + + align:start position:0% +into the same river twice it's very true +here + + align:start position:0% +here + + + align:start position:0% +here +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and as a result + + align:start position:0% +and as a result + + + align:start position:0% +and as a result +people + + align:start position:0% +people + + + align:start position:0% +people +people often will + + align:start position:0% +people often will + + + align:start position:0% +people often will +try to massage the data later on after + + align:start position:0% +try to massage the data later on after + + + align:start position:0% +try to massage the data later on after +the test tube comes the numbers + + align:start position:0% +the test tube comes the numbers + + + align:start position:0% +the test tube comes the numbers +uh well he has to go through certain + + align:start position:0% +uh well he has to go through certain + + + align:start position:0% +uh well he has to go through certain +scanners and machines but the kind when + + align:start position:0% +scanners and machines but the kind when + + + align:start position:0% +scanners and machines but the kind when +the numbers come out then they massage + + align:start position:0% +the numbers come out then they massage + + + align:start position:0% +the numbers come out then they massage +it + + align:start position:0% +it + + + align:start position:0% +it +they normalize in other words to uh + + align:start position:0% +they normalize in other words to uh + + + align:start position:0% +they normalize in other words to uh +somehow account + + align:start position:0% +somehow account + + + align:start position:0% +somehow account +for um + + align:start position:0% +for um + + + align:start position:0% +for um +biological variation or measurement + + align:start position:0% +biological variation or measurement + + + align:start position:0% +biological variation or measurement +variation + + align:start position:0% +variation + + + align:start position:0% +variation +okay + + align:start position:0% +okay + + + align:start position:0% +okay +there are arguments for and against + + align:start position:0% +there are arguments for and against + + + align:start position:0% +there are arguments for and against +normalization + + align:start position:0% +normalization + + + align:start position:0% +normalization +and + + align:start position:0% +and + + + align:start position:0% +and +there is no + + align:start position:0% +there is no + + + align:start position:0% +there is no +blanket uh in principle whether to do + + align:start position:0% +blanket uh in principle whether to do + + + align:start position:0% +blanket uh in principle whether to do +this to minimize or not it depends on + + align:start position:0% +this to minimize or not it depends on + + + align:start position:0% +this to minimize or not it depends on +your experiment design + + align:start position:0% +your experiment design + + + align:start position:0% +your experiment design +okay i will i give an example of that + + align:start position:0% +okay i will i give an example of that + + + align:start position:0% +okay i will i give an example of that +pancreatic development data + + align:start position:0% +pancreatic development data + + + align:start position:0% +pancreatic development data +um embryonic day 12 + + align:start position:0% +um embryonic day 12 + + + align:start position:0% +um embryonic day 12 +14 18 postnatal day 2 and the adult + + align:start position:0% +14 18 postnatal day 2 and the adult + + + align:start position:0% +14 18 postnatal day 2 and the adult +pancreas and i'm simply plotting the 10 + + align:start position:0% +pancreas and i'm simply plotting the 10 + + + align:start position:0% +pancreas and i'm simply plotting the 10 +000 genes + + align:start position:0% +000 genes + + + align:start position:0% +000 genes +uh against itself here okay + + align:start position:0% +uh against itself here okay + + + align:start position:0% +uh against itself here okay +embryonic natural against itself + + align:start position:0% +embryonic natural against itself + + + align:start position:0% +embryonic natural against itself +and e12 against its alloquote what is + + align:start position:0% +and e12 against its alloquote what is + + + align:start position:0% +and e12 against its alloquote what is +the other chord um + + align:start position:0% +the other chord um + + + align:start position:0% +the other chord um +i i think actually alicorn in this case + + align:start position:0% +i i think actually alicorn in this case + + + align:start position:0% +i i think actually alicorn in this case +was this + + align:start position:0% +was this + + + align:start position:0% +was this +it's a measurement variation + + align:start position:0% +it's a measurement variation + + + align:start position:0% +it's a measurement variation +okay though in a way it's not very wise + + align:start position:0% +okay though in a way it's not very wise + + + align:start position:0% +okay though in a way it's not very wise +in the case of a + + align:start position:0% +in the case of a + + + align:start position:0% +in the case of a +you clearly cannot remove the whole + + align:start position:0% +you clearly cannot remove the whole + + + align:start position:0% +you clearly cannot remove the whole +bankrupt from the same mouse twice right + + align:start position:0% +bankrupt from the same mouse twice right + + + align:start position:0% +bankrupt from the same mouse twice right +so it may have been + + align:start position:0% +so it may have been + + + align:start position:0% +so it may have been +wiser to have done this kind of think of + + align:start position:0% +wiser to have done this kind of think of + + + align:start position:0% +wiser to have done this kind of think of +it now to account for biological + + align:start position:0% +it now to account for biological + + + align:start position:0% +it now to account for biological +variation because + + align:start position:0% + + + + align:start position:0% + +in this case then + + align:start position:0% + + + + align:start position:0% + +i it could have if it was measurement + + align:start position:0% +i it could have if it was measurement + + + align:start position:0% +i it could have if it was measurement +variation + + align:start position:0% +variation + + + align:start position:0% +variation +then clearly + + align:start position:0% +then clearly + + + align:start position:0% +then clearly +um there are two confounding factors + + align:start position:0% +um there are two confounding factors + + + align:start position:0% +um there are two confounding factors +here number one is measurement variation + + align:start position:0% +here number one is measurement variation + + + align:start position:0% +here number one is measurement variation +number two biological variation so it + + align:start position:0% +number two biological variation so it + + + align:start position:0% +number two biological variation so it +would have been nice in a way if we have + + align:start position:0% +would have been nice in a way if we have + + + align:start position:0% +would have been nice in a way if we have +biological variation captured here so + + align:start position:0% +biological variation captured here so + + + align:start position:0% +biological variation captured here so +e12 you see that it starts to spread + + align:start position:0% +e12 you see that it starts to spread + + + align:start position:0% +e12 you see that it starts to spread +like a comet + + align:start position:0% +like a comet + + + align:start position:0% +like a comet +and as you progress with development + + align:start position:0% +and as you progress with development + + + align:start position:0% +and as you progress with development +you can see that it spreads even worse + + align:start position:0% +you can see that it spreads even worse + + + align:start position:0% +you can see that it spreads even worse +it looks less and less alike the most + + align:start position:0% +it looks less and less alike the most + + + align:start position:0% +it looks less and less alike the most +alike is here + + align:start position:0% +alike is here + + + align:start position:0% +alike is here +they should align up right you're + + align:start position:0% +they should align up right you're + + + align:start position:0% +they should align up right you're +supposed to be taking the same reading + + align:start position:0% +supposed to be taking the same reading + + + align:start position:0% +supposed to be taking the same reading +of the same thing + + align:start position:0% +of the same thing + + + align:start position:0% +of the same thing +of course here's by the time it reaches + + align:start position:0% +of course here's by the time it reaches + + + align:start position:0% +of course here's by the time it reaches +adulthood anything can happen + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +we don't know it what are your a priori + + align:start position:0% +we don't know it what are your a priori + + + align:start position:0% +we don't know it what are your a priori +assumptions about the system + + align:start position:0% +assumptions about the system + + + align:start position:0% +assumptions about the system +guides you on whether or not to + + align:start position:0% +guides you on whether or not to + + + align:start position:0% +guides you on whether or not to +normalize + + align:start position:0% +normalize + + + align:start position:0% +normalize +if you believe if you have done + + align:start position:0% +if you believe if you have done + + + align:start position:0% +if you believe if you have done +10 whole microarrays for + + align:start position:0% +10 whole microarrays for + + + align:start position:0% +10 whole microarrays for +some system + + align:start position:0% +some system + + + align:start position:0% +some system +and you believe that the system should + + align:start position:0% +and you believe that the system should + + + align:start position:0% +and you believe that the system should +be remaining consistent + + align:start position:0% +be remaining consistent + + + align:start position:0% +be remaining consistent +despite the biological variation etc + + align:start position:0% +despite the biological variation etc + + + align:start position:0% +despite the biological variation etc +then + + align:start position:0% + + + + align:start position:0% + +you could claim that + + align:start position:0% + + + + align:start position:0% + +the average of these array readings have + + align:start position:0% +the average of these array readings have + + + align:start position:0% +the average of these array readings have +to be the same + + align:start position:0% +to be the same + + + align:start position:0% +to be the same +or + + align:start position:0% +or + + + align:start position:0% +or +the variance should be + + align:start position:0% +the variance should be + + + align:start position:0% +the variance should be +a certain quantity but that's actually + + align:start position:0% +a certain quantity but that's actually + + + align:start position:0% +a certain quantity but that's actually +how to say uh putting your own + + align:start position:0% +how to say uh putting your own + + + align:start position:0% +how to say uh putting your own +assumptions of your of how the system + + align:start position:0% +assumptions of your of how the system + + + align:start position:0% +assumptions of your of how the system +behaves into this + + align:start position:0% +behaves into this + + + align:start position:0% +behaves into this +actual uh phenomenon that's unfolding + + align:start position:0% +actual uh phenomenon that's unfolding + + + align:start position:0% +actual uh phenomenon that's unfolding +um so one has to be careful + + align:start position:0% +um so one has to be careful + + + align:start position:0% +um so one has to be careful +the common common normalization + + align:start position:0% +the common common normalization + + + align:start position:0% +the common common normalization +technique that people use are + + align:start position:0% +technique that people use are + + + align:start position:0% +technique that people use are +the one which we have actually talked + + align:start position:0% +the one which we have actually talked + + + align:start position:0% +the one which we have actually talked +about central limit theorem scaling + + align:start position:0% +about central limit theorem scaling + + + align:start position:0% +about central limit theorem scaling +meaning that the um + + align:start position:0% +meaning that the um + + + align:start position:0% +meaning that the um +this is a vector actually vector x + + align:start position:0% +this is a vector actually vector x + + + align:start position:0% +this is a vector actually vector x +against the reference r so it's the you + + align:start position:0% +against the reference r so it's the you + + + align:start position:0% +against the reference r so it's the you +simply subtract the average from each + + align:start position:0% +simply subtract the average from each + + + align:start position:0% +simply subtract the average from each +component + + align:start position:0% +component + + + align:start position:0% +component +of the vector x and you divide it by the + + align:start position:0% +of the vector x and you divide it by the + + + align:start position:0% +of the vector x and you divide it by the +standard deviation the + + align:start position:0% +standard deviation the + + + align:start position:0% +standard deviation the +end result actually is a quantity which + + align:start position:0% +end result actually is a quantity which + + + align:start position:0% +end result actually is a quantity which +has + + align:start position:0% +has + + + align:start position:0% +has +um mean zero and variance one + + align:start position:0% + + + + align:start position:0% + +some people have reason to do this some + + align:start position:0% +some people have reason to do this some + + + align:start position:0% +some people have reason to do this some +people don't have a reason to do it but + + align:start position:0% +people don't have a reason to do it but + + + align:start position:0% +people don't have a reason to do it but +they do it after anyways + + align:start position:0% +they do it after anyways + + + align:start position:0% +they do it after anyways +you just have to be very careful + + align:start position:0% +you just have to be very careful + + + align:start position:0% +you just have to be very careful +so what happens well we just saw what + + align:start position:0% +so what happens well we just saw what + + + align:start position:0% +so what happens well we just saw what +happens + + align:start position:0% +happens + + + align:start position:0% +happens +by so doing you have mapped actually + + align:start position:0% +by so doing you have mapped actually + + + align:start position:0% +by so doing you have mapped actually +this entire vector + + align:start position:0% +this entire vector + + + align:start position:0% +this entire vector +into a + + align:start position:0% +into a + + + align:start position:0% +into a +an element of the unit hypersphere turns + + align:start position:0% +an element of the unit hypersphere turns + + + align:start position:0% +an element of the unit hypersphere turns +out okay + + align:start position:0% +out okay + + + align:start position:0% +out okay +so you do lose information maybe you + + align:start position:0% +so you do lose information maybe you + + + align:start position:0% +so you do lose information maybe you +lose all notion of um + + align:start position:0% +lose all notion of um + + + align:start position:0% +lose all notion of um +i mean + + align:start position:0% +i mean + + + align:start position:0% +i mean +absoluteness absolute intensities + + align:start position:0% +absoluteness absolute intensities + + + align:start position:0% +absoluteness absolute intensities +the second common method of + + align:start position:0% +the second common method of + + + align:start position:0% +the second common method of +normalization is + + align:start position:0% +normalization is + + + align:start position:0% +normalization is +you have a reference data set + + align:start position:0% +you have a reference data set + + + align:start position:0% +you have a reference data set +and you + + align:start position:0% +and you + + + align:start position:0% +and you +regress against that + + align:start position:0% +regress against that + + + align:start position:0% +regress against that +reference data set what do i mean well + + align:start position:0% +reference data set what do i mean well + + + align:start position:0% +reference data set what do i mean well +if you + + align:start position:0% +if you + + + align:start position:0% +if you +so back to this say + + align:start position:0% +so back to this say + + + align:start position:0% +so back to this say +if you take the e12 + + align:start position:0% +if you take the e12 + + + align:start position:0% +if you take the e12 +to be the reference data set okay + + align:start position:0% +to be the reference data set okay + + + align:start position:0% +to be the reference data set okay +and + + align:start position:0% +and + + + align:start position:0% +and +you're trying to you regress everything + + align:start position:0% +you're trying to you regress everything + + + align:start position:0% +you're trying to you regress everything +to it or normalize everything to it then + + align:start position:0% +to it or normalize everything to it then + + + align:start position:0% +to it or normalize everything to it then +for example + + align:start position:0% +for example + + + align:start position:0% +for example +the e12 second allocate against the + + align:start position:0% +the e12 second allocate against the + + + align:start position:0% +the e12 second allocate against the +first e12 + + align:start position:0% + + + + align:start position:0% + +in an ideal world + + align:start position:0% +in an ideal world + + + align:start position:0% +in an ideal world +you have to get scattered that's clear + + align:start position:0% +you have to get scattered that's clear + + + align:start position:0% +you have to get scattered that's clear +however + + align:start position:0% +however + + + align:start position:0% +however +even through the scatter + + align:start position:0% +even through the scatter + + + align:start position:0% +even through the scatter +some people believe that the linear + + align:start position:0% +some people believe that the linear + + + align:start position:0% +some people believe that the linear +regression line + + align:start position:0% +regression line + + + align:start position:0% +regression line +has to be of slope 1 + + align:start position:0% +has to be of slope 1 + + + align:start position:0% +has to be of slope 1 +and going to the origin + + align:start position:0% +and going to the origin + + + align:start position:0% +and going to the origin +if it isn't make it + + align:start position:0% +if it isn't make it + + + align:start position:0% +if it isn't make it +so + + align:start position:0% +so + + + align:start position:0% +so +so it's a linear transformation of the + + align:start position:0% +so it's a linear transformation of the + + + align:start position:0% +so it's a linear transformation of the +second alloy quote by basically uh you + + align:start position:0% +second alloy quote by basically uh you + + + align:start position:0% +second alloy quote by basically uh you +subtract and you divide you know it's + + align:start position:0% +subtract and you divide you know it's + + + align:start position:0% +subtract and you divide you know it's +just a translation + + align:start position:0% +just a translation + + + align:start position:0% +just a translation +of the data so that the regression of + + align:start position:0% +of the data so that the regression of + + + align:start position:0% +of the data so that the regression of +one against the other is now + + align:start position:0% +one against the other is now + + + align:start position:0% +one against the other is now +going to the origin and has slope one + + align:start position:0% +going to the origin and has slope one + + + align:start position:0% +going to the origin and has slope one +you do it for in the entire um + + align:start position:0% +you do it for in the entire um + + + align:start position:0% +you do it for in the entire um +time series + + align:start position:0% +time series + + + align:start position:0% +time series +in this case for example + + align:start position:0% +in this case for example + + + align:start position:0% +in this case for example +there are reasons to do it there are + + align:start position:0% +there are reasons to do it there are + + + align:start position:0% +there are reasons to do it there are +reasons not to do it + + align:start position:0% +reasons not to do it + + + align:start position:0% +reasons not to do it +what actually happens after you do it + + align:start position:0% +what actually happens after you do it + + + align:start position:0% +what actually happens after you do it +well clearly then all these samples are + + align:start position:0% +well clearly then all these samples are + + + align:start position:0% +well clearly then all these samples are +now going to have regression + + align:start position:0% +now going to have regression + + + align:start position:0% +now going to have regression +intercept 0 slope 1 against the + + align:start position:0% +intercept 0 slope 1 against the + + + align:start position:0% +intercept 0 slope 1 against the +reference a second thing that comes out + + align:start position:0% +reference a second thing that comes out + + + align:start position:0% +reference a second thing that comes out +of this is + + align:start position:0% +of this is + + + align:start position:0% +of this is +all the vectors the newly normalized + + align:start position:0% +all the vectors the newly normalized + + + align:start position:0% +all the vectors the newly normalized +vectors will have the same average + + align:start position:0% +vectors will have the same average + + + align:start position:0% +vectors will have the same average +you can show that for yourself but you + + align:start position:0% +you can show that for yourself but you + + + align:start position:0% +you can show that for yourself but you +can do the arithmetic you'll see that + + align:start position:0% +can do the arithmetic you'll see that + + + align:start position:0% +can do the arithmetic you'll see that +come out for + + align:start position:0% +come out for + + + align:start position:0% +come out for +free okay + + align:start position:0% +free okay + + + align:start position:0% +free okay +um + + align:start position:0% +um + + + align:start position:0% +um +then there is a notion of a fault + + align:start position:0% +then there is a notion of a fault + + + align:start position:0% +then there is a notion of a fault +that you hear all the time which is very + + align:start position:0% +that you hear all the time which is very + + + align:start position:0% +that you hear all the time which is very +natural when it comes to pcr and blots + + align:start position:0% +natural when it comes to pcr and blots + + + align:start position:0% +natural when it comes to pcr and blots +but + + align:start position:0% +but + + + align:start position:0% +but +the question is does the phone actually + + align:start position:0% +the question is does the phone actually + + + align:start position:0% +the question is does the phone actually +make sense in the context of + + align:start position:0% +make sense in the context of + + + align:start position:0% +make sense in the context of +epimetric chips + + align:start position:0% +epimetric chips + + + align:start position:0% +epimetric chips +okay + + align:start position:0% +okay + + + align:start position:0% +okay +for example you often encounter this + + align:start position:0% +for example you often encounter this + + + align:start position:0% +for example you often encounter this +right you have a + + align:start position:0% + + + + align:start position:0% + +sample population a + + align:start position:0% +sample population a + + + align:start position:0% +sample population a +and you have three readings for that + + align:start position:0% +and you have three readings for that + + + align:start position:0% +and you have three readings for that +sample population a + + align:start position:0% +sample population a + + + align:start position:0% +sample population a +and versus b which has another three + + align:start position:0% +and versus b which has another three + + + align:start position:0% +and versus b which has another three +readings + + align:start position:0% +readings + + + align:start position:0% +readings +and we uh people will ask what is the + + align:start position:0% +and we uh people will ask what is the + + + align:start position:0% +and we uh people will ask what is the +fall change from here to there + + align:start position:0% +fall change from here to there + + + align:start position:0% +fall change from here to there +and notice that there is a negative here + + align:start position:0% +and notice that there is a negative here + + + align:start position:0% +and notice that there is a negative here +too okay + + align:start position:0% +too okay + + + align:start position:0% +too okay +yes they have done many ways have been + + align:start position:0% +yes they have done many ways have been + + + align:start position:0% +yes they have done many ways have been +um proposed to solve this problem + + align:start position:0% +um proposed to solve this problem + + + align:start position:0% +um proposed to solve this problem +you could take the arithmetic average + + align:start position:0% +you could take the arithmetic average + + + align:start position:0% +you could take the arithmetic average +here + + align:start position:0% +here + + + align:start position:0% +here +then divide it by the arithmetic average + + align:start position:0% +then divide it by the arithmetic average + + + align:start position:0% +then divide it by the arithmetic average +there + + align:start position:0% +there + + + align:start position:0% +there +there's a negative there though negative + + align:start position:0% +there's a negative there though negative + + + align:start position:0% +there's a negative there though negative +point so does the fall actually make + + align:start position:0% +point so does the fall actually make + + + align:start position:0% +point so does the fall actually make +sense in this setting + + align:start position:0% + + + + align:start position:0% + +alternatively + + align:start position:0% +alternatively + + + align:start position:0% +alternatively +some people have used a + + align:start position:0% +some people have used a + + + align:start position:0% +some people have used a +the geometric average rather than the + + align:start position:0% +the geometric average rather than the + + + align:start position:0% +the geometric average rather than the +arithmetic average + + align:start position:0% +arithmetic average + + + align:start position:0% +arithmetic average +okay + + align:start position:0% +okay + + + align:start position:0% +okay +or they have logged it somehow but logs + + align:start position:0% +or they have logged it somehow but logs + + + align:start position:0% +or they have logged it somehow but logs +only + + align:start position:0% +only + + + align:start position:0% +only +uh well posed on a set of positive + + align:start position:0% +uh well posed on a set of positive + + + align:start position:0% +uh well posed on a set of positive +numbers + + align:start position:0% + + + + align:start position:0% + +not even zero um + + align:start position:0% +not even zero um + + + align:start position:0% +not even zero um +one argument against using foal actually + + align:start position:0% +one argument against using foal actually + + + align:start position:0% +one argument against using foal actually +is that it is not stable + + align:start position:0% +is that it is not stable + + + align:start position:0% +is that it is not stable +it is incredibly not stable um + + align:start position:0% +it is incredibly not stable um + + + align:start position:0% +it is incredibly not stable um +and + + align:start position:0% +and + + + align:start position:0% +and +highly sensitive to its denominator for + + align:start position:0% +highly sensitive to its denominator for + + + align:start position:0% +highly sensitive to its denominator for +instance + + align:start position:0% +instance + + + align:start position:0% +instance +um 20 over 10 50 over 25 and 200 200 + + align:start position:0% +um 20 over 10 50 over 25 and 200 200 + + + align:start position:0% +um 20 over 10 50 over 25 and 200 200 +over 100 are all equal to two right + + align:start position:0% +over 100 are all equal to two right + + + align:start position:0% +over 100 are all equal to two right +let's actually perturb them by the same + + align:start position:0% +let's actually perturb them by the same + + + align:start position:0% +let's actually perturb them by the same +quantity epsilon okay this is the + + align:start position:0% +quantity epsilon okay this is the + + + align:start position:0% +quantity epsilon okay this is the +perturbation epsilon can be positive or + + align:start position:0% +perturbation epsilon can be positive or + + + align:start position:0% +perturbation epsilon can be positive or +negative + + align:start position:0% +negative + + + align:start position:0% +negative +now + + align:start position:0% +now + + + align:start position:0% +now +20 of a 10 when you perturb it by + + align:start position:0% +20 of a 10 when you perturb it by + + + align:start position:0% +20 of a 10 when you perturb it by +epsilon + + align:start position:0% +epsilon + + + align:start position:0% +epsilon +it swings + + align:start position:0% +it swings + + + align:start position:0% +it swings +from all the way from three-fold + + align:start position:0% +from all the way from three-fold + + + align:start position:0% +from all the way from three-fold +to something so small that on one point + + align:start position:0% +to something so small that on one point + + + align:start position:0% +to something so small that on one point +eight folds in + + align:start position:0% +eight folds in + + + align:start position:0% +eight folds in +but this quantity here is more stable + + align:start position:0% +but this quantity here is more stable + + + align:start position:0% +but this quantity here is more stable +so does it mean that fos actually only + + align:start position:0% +so does it mean that fos actually only + + + align:start position:0% +so does it mean that fos actually only +makes sense if the absolute + + align:start position:0% +makes sense if the absolute + + + align:start position:0% +makes sense if the absolute +numbers involved or the absolute + + align:start position:0% +numbers involved or the absolute + + + align:start position:0% +numbers involved or the absolute +averages involved are large + + align:start position:0% +averages involved are large + + + align:start position:0% +averages involved are large +so it's much more flatter here you can + + align:start position:0% +so it's much more flatter here you can + + + align:start position:0% +so it's much more flatter here you can +say it's more robust + + align:start position:0% + + + + align:start position:0% + +so these are things that one actually + + align:start position:0% +so these are things that one actually + + + align:start position:0% +so these are things that one actually +should be aware of when + + align:start position:0% +should be aware of when + + + align:start position:0% +should be aware of when +doing analysis or when reading the + + align:start position:0% +doing analysis or when reading the + + + align:start position:0% +doing analysis or when reading the +papers and what they mean by folds + + align:start position:0% +papers and what they mean by folds + + + align:start position:0% +papers and what they mean by folds +again you recall that our we have + + align:start position:0% +again you recall that our we have + + + align:start position:0% +again you recall that our we have +covered actually all of this + + align:start position:0% +covered actually all of this + + + align:start position:0% +covered actually all of this +the study design prototypical + + align:start position:0% +the study design prototypical + + + align:start position:0% +the study design prototypical +study designs and data representation + + align:start position:0% +study designs and data representation + + + align:start position:0% +study designs and data representation +background and the last slide + + align:start position:0% +background and the last slide + + + align:start position:0% +background and the last slide +essentially is just a miscellaneous + + align:start position:0% +essentially is just a miscellaneous + + + align:start position:0% +essentially is just a miscellaneous +so our discussion so far if you notice + + align:start position:0% +so our discussion so far if you notice + + + align:start position:0% +so our discussion so far if you notice +does not + + align:start position:0% + + + + align:start position:0% + +require biology + + align:start position:0% +require biology + + + align:start position:0% +require biology +it just makes nominal reference to + + align:start position:0% +it just makes nominal reference to + + + align:start position:0% +it just makes nominal reference to +biology and the approaches are very + + align:start position:0% +biology and the approaches are very + + + align:start position:0% +biology and the approaches are very +general if you think about it it would + + align:start position:0% +general if you think about it it would + + + align:start position:0% +general if you think about it it would +apply in any data set whether or not it + + align:start position:0% +apply in any data set whether or not it + + + align:start position:0% +apply in any data set whether or not it +came from biology + + align:start position:0% +came from biology + + + align:start position:0% +came from biology +but one should be aware that the math or + + align:start position:0% +but one should be aware that the math or + + + align:start position:0% +but one should be aware that the math or +the statistics will only provide the + + align:start position:0% +the statistics will only provide the + + + align:start position:0% +the statistics will only provide the +tool for biological discovery and the + + align:start position:0% +tool for biological discovery and the + + + align:start position:0% +tool for biological discovery and the +key thing we are all here to do is to + + align:start position:0% +key thing we are all here to do is to + + + align:start position:0% +key thing we are all here to do is to +understand the biology right + + align:start position:0% +understand the biology right + + + align:start position:0% +understand the biology right +and um + + align:start position:0% +and um + + + align:start position:0% +and um +because that actually will dictate for + + align:start position:0% +because that actually will dictate for + + + align:start position:0% +because that actually will dictate for +you the experiment design + + align:start position:0% +you the experiment design + + + align:start position:0% +you the experiment design +the appropriate + + align:start position:0% +the appropriate + + + align:start position:0% +the appropriate +measure or + + align:start position:0% +measure or + + + align:start position:0% +measure or +similarity space to formulate your + + align:start position:0% +similarity space to formulate your + + + align:start position:0% +similarity space to formulate your +problem + + align:start position:0% +problem + + + align:start position:0% +problem +and also in reading and making sense of + + align:start position:0% +and also in reading and making sense of + + + align:start position:0% +and also in reading and making sense of +what your model gives you after you have + + align:start position:0% +what your model gives you after you have + + + align:start position:0% +what your model gives you after you have +done this + + align:start position:0% +done this + + + align:start position:0% +done this +okay and a very very important thing is + + align:start position:0% +okay and a very very important thing is + + + align:start position:0% +okay and a very very important thing is +no study is ever hypothesis free you are + + align:start position:0% +no study is ever hypothesis free you are + + + align:start position:0% +no study is ever hypothesis free you are +going to read things into your study no + + align:start position:0% +going to read things into your study no + + + align:start position:0% +going to read things into your study no +matter what it is best to be very + + align:start position:0% +matter what it is best to be very + + + align:start position:0% +matter what it is best to be very +explicit in the beginning what your + + align:start position:0% +explicit in the beginning what your + + + align:start position:0% +explicit in the beginning what your +hypothesis are and + + align:start position:0% +hypothesis are and + + + align:start position:0% +hypothesis are and +a lot of studies i've noticed have + + align:start position:0% +a lot of studies i've noticed have + + + align:start position:0% +a lot of studies i've noticed have +completely deluded themselves into + + align:start position:0% +completely deluded themselves into + + + align:start position:0% +completely deluded themselves into +thinking that they are + + align:start position:0% +thinking that they are + + + align:start position:0% +thinking that they are +unsupervised or hypothesis-free there is + + align:start position:0% +unsupervised or hypothesis-free there is + + + align:start position:0% +unsupervised or hypothesis-free there is +some hypothesis i'm sorry to say even + + align:start position:0% +some hypothesis i'm sorry to say even + + + align:start position:0% +some hypothesis i'm sorry to say even +principal component analysis has been + + align:start position:0% +principal component analysis has been + + + align:start position:0% +principal component analysis has been +claimed to be unsupervised that's not + + align:start position:0% +claimed to be unsupervised that's not + + + align:start position:0% +claimed to be unsupervised that's not +true well it is unsupervised in the + + align:start position:0% +true well it is unsupervised in the + + + align:start position:0% +true well it is unsupervised in the +sense that you just let things fall but + + align:start position:0% +sense that you just let things fall but + + + align:start position:0% +sense that you just let things fall but +the underlying assumption is that the + + align:start position:0% +the underlying assumption is that the + + + align:start position:0% +the underlying assumption is that the +measure of similarity there is euclidean + + align:start position:0% +measure of similarity there is euclidean + + + align:start position:0% +measure of similarity there is euclidean +distance + + align:start position:0% +distance + + + align:start position:0% +distance +that matters actually + + align:start position:0% + + + + align:start position:0% + +and i end + + align:start position:0% +and i end + + + align:start position:0% +and i end +early + + align:start position:0% +early + + + align:start position:0% +early +with a quote from um + + align:start position:0% +with a quote from um + + + align:start position:0% +with a quote from um +some uh an evolutionary by a + + align:start position:0% +some uh an evolutionary by a + + + align:start position:0% +some uh an evolutionary by a +biologist a french one from the 18th + + align:start position:0% +biologist a french one from the 18th + + + align:start position:0% +biologist a french one from the 18th +century that the discoveries that one + + align:start position:0% +century that the discoveries that one + + + align:start position:0% +century that the discoveries that one +can make with a microscope amount to + + align:start position:0% +can make with a microscope amount to + + + align:start position:0% +can make with a microscope amount to +very little + + align:start position:0% +very little + + + align:start position:0% +very little +so you can see with your mind's eyes and + + align:start position:0% +so you can see with your mind's eyes and + + + align:start position:0% +so you can see with your mind's eyes and +without the microscope the real + + align:start position:0% +without the microscope the real + + + align:start position:0% +without the microscope the real +existence of these little beings i think + + align:start position:0% +existence of these little beings i think + + + align:start position:0% +existence of these little beings i think +it was referring to uh + + align:start position:0% +it was referring to uh + + + align:start position:0% +it was referring to uh +microbes or very small features + + align:start position:0% +microbes or very small features + + + align:start position:0% +microbes or very small features +thank you \ No newline at end of file diff --git a/ytGmd25_10k.txt b/ytGmd25_10k.txt new file mode 100644 index 0000000000000000000000000000000000000000..a8dd9e8d0627b55838fb481eb1b3132c9e738d20 --- /dev/null +++ b/ytGmd25_10k.txt @@ -0,0 +1,8211 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +I wanted to tell you a little bit about + + align:start position:0% +I wanted to tell you a little bit about + + + align:start position:0% +I wanted to tell you a little bit about +the use of digital communication schemes + + align:start position:0% +the use of digital communication schemes + + + align:start position:0% +the use of digital communication schemes +in the space uh program and part of that + + align:start position:0% +in the space uh program and part of that + + + align:start position:0% +in the space uh program and part of that +is it's not it wasn't just the use a lot + + align:start position:0% +is it's not it wasn't just the use a lot + + + align:start position:0% +is it's not it wasn't just the use a lot +of coding theory was developed for use + + align:start position:0% +of coding theory was developed for use + + + align:start position:0% +of coding theory was developed for use +in this program. So um + + align:start position:0% +in this program. So um + + + align:start position:0% +in this program. So um +uh in the early days there was no error + + align:start position:0% +uh in the early days there was no error + + + align:start position:0% +uh in the early days there was no error +control coding. So they had very slow + + align:start position:0% +control coding. So they had very slow + + + align:start position:0% +control coding. So they had very slow +transmission rates um and tried to + + align:start position:0% +transmission rates um and tried to + + + align:start position:0% +transmission rates um and tried to +compensate for not having error control + + align:start position:0% +compensate for not having error control + + + align:start position:0% +compensate for not having error control +coding by um taking a long time to send + + align:start position:0% +coding by um taking a long time to send + + + align:start position:0% +coding by um taking a long time to send +a bit over um but in later years uh with + + align:start position:0% +a bit over um but in later years uh with + + + align:start position:0% +a bit over um but in later years uh with +the mariner and viking probes uh they + + align:start position:0% +the mariner and viking probes uh they + + + align:start position:0% +the mariner and viking probes uh they +started to use error control codes and + + align:start position:0% +started to use error control codes and + + + align:start position:0% +started to use error control codes and +linear block codes are what we're + + align:start position:0% +linear block codes are what we're + + + align:start position:0% +linear block codes are what we're +talking about. Um this would be the + + align:start position:0% +talking about. Um this would be the + + + align:start position:0% +talking about. Um this would be the +typical parameters for such a code. So + + align:start position:0% +typical parameters for such a code. So + + + align:start position:0% +typical parameters for such a code. So +we know how to read this. This is uh 32 + + align:start position:0% +we know how to read this. This is uh 32 + + + align:start position:0% +we know how to read this. This is uh 32 +bits per block, six data bits and a + + align:start position:0% +bits per block, six data bits and a + + + align:start position:0% +bits per block, six data bits and a +minimum hamming distance of 16. A + + align:start position:0% +minimum hamming distance of 16. A + + + align:start position:0% +minimum hamming distance of 16. A +particular kind of code called a + + align:start position:0% +particular kind of code called a + + + align:start position:0% +particular kind of code called a +borththogonal code or a hadomard code uh + + align:start position:0% +borththogonal code or a hadomard code uh + + + align:start position:0% +borththogonal code or a hadomard code uh +which had specific characteristics and + + align:start position:0% +which had specific characteristics and + + + align:start position:0% +which had specific characteristics and +specific symmetries that actually helped + + align:start position:0% +specific symmetries that actually helped + + + align:start position:0% +specific symmetries that actually helped +with the uh uh decoding. + + align:start position:0% +with the uh uh decoding. + + + align:start position:0% +with the uh uh decoding. +So for instance on um Mariner 9 um it's + + align:start position:0% +So for instance on um Mariner 9 um it's + + + align:start position:0% +So for instance on um Mariner 9 um it's +1971 this went into Mars orbit and uh + + align:start position:0% +1971 this went into Mars orbit and uh + + + align:start position:0% +1971 this went into Mars orbit and uh +the code was used to um encode the + + align:start position:0% +the code was used to um encode the + + + align:start position:0% +the code was used to um encode the +picture transmissions. So um each data + + align:start position:0% +picture transmissions. So um each data + + + align:start position:0% +picture transmissions. So um each data +word was six bits to encode 64 gray + + align:start position:0% +word was six bits to encode 64 gray + + + align:start position:0% +word was six bits to encode 64 gray +levels in a picture. Uh it turned out + + align:start position:0% +levels in a picture. Uh it turned out + + + align:start position:0% +levels in a picture. Uh it turned out +that because of uh transmission issues + + align:start position:0% +that because of uh transmission issues + + + align:start position:0% +that because of uh transmission issues +the uh safe number of bits for a block + + align:start position:0% +the uh safe number of bits for a block + + + align:start position:0% +the uh safe number of bits for a block +was 30 bits and after that you had to do + + align:start position:0% +was 30 bits and after that you had to do + + + align:start position:0% +was 30 bits and after that you had to do +a little bit of re realigning or + + align:start position:0% +a little bit of re realigning or + + + align:start position:0% +a little bit of re realigning or +tweaking. So you could um send 30 bits + + align:start position:0% +tweaking. So you could um send 30 bits + + + align:start position:0% +tweaking. So you could um send 30 bits +at a time safely and so that was a + + align:start position:0% +at a time safely and so that was a + + + align:start position:0% +at a time safely and so that was a +choice of n in that vicinity was a + + align:start position:0% +choice of n in that vicinity was a + + + align:start position:0% +choice of n in that vicinity was a +natural choice. Uh one thing you could + + align:start position:0% +natural choice. Uh one thing you could + + + align:start position:0% +natural choice. Uh one thing you could +have thought to do would be take the six + + align:start position:0% +have thought to do would be take the six + + + align:start position:0% +have thought to do would be take the six +bits and repeat them five times in that + + align:start position:0% +bits and repeat them five times in that + + + align:start position:0% +bits and repeat them five times in that +30-bit window and that would be a + + align:start position:0% +30-bit window and that would be a + + + align:start position:0% +30-bit window and that would be a +repetition code. Um it turned out that + + align:start position:0% +repetition code. Um it turned out that + + + align:start position:0% +repetition code. Um it turned out that +with this particular hatamard code you + + align:start position:0% +with this particular hatamard code you + + + align:start position:0% +with this particular hatamard code you +could actually um get the same uh data + + align:start position:0% +could actually um get the same uh data + + + align:start position:0% +could actually um get the same uh data +rates or comparable data rates. Let's + + align:start position:0% +rates or comparable data rates. Let's + + + align:start position:0% +rates or comparable data rates. Let's +see what would the data rate be k over n + + align:start position:0% +see what would the data rate be k over n + + + align:start position:0% +see what would the data rate be k over n +right 6 over 32 um but with much better + + align:start position:0% +right 6 over 32 um but with much better + + + align:start position:0% +right 6 over 32 um but with much better +error correction properties. So let's + + align:start position:0% +error correction properties. So let's + + + align:start position:0% +error correction properties. So let's +see how many errors could you correct in + + align:start position:0% +see how many errors could you correct in + + + align:start position:0% +see how many errors could you correct in +this code + + align:start position:0% +this code + + + align:start position:0% +this code +per block. + + align:start position:0% + + + + align:start position:0% + +somebody + + align:start position:0% +somebody + + + align:start position:0% +somebody +seven. Yeah, + + align:start position:0% +seven. Yeah, + + + align:start position:0% +seven. Yeah, +because you've got a minimum having + + align:start position:0% +because you've got a minimum having + + + align:start position:0% +because you've got a minimum having +distance of 16. Um, so you want d minus + + align:start position:0% +distance of 16. Um, so you want d minus + + + align:start position:0% +distance of 16. Um, so you want d minus +one over two the floor of that, right? + + align:start position:0% +one over two the floor of that, right? + + + align:start position:0% +one over two the floor of that, right? +So you could correct up to seven errors + + align:start position:0% +So you could correct up to seven errors + + + align:start position:0% +So you could correct up to seven errors +per block. And this code was actually + + align:start position:0% +per block. And this code was actually + + + align:start position:0% +per block. And this code was actually +used on space probes right into the 80s. + + align:start position:0% +used on space probes right into the 80s. + + + align:start position:0% +used on space probes right into the 80s. +Um, and as I mentioned, this particular + + align:start position:0% +Um, and as I mentioned, this particular + + + align:start position:0% +Um, and as I mentioned, this particular +code has various symmetries that allow + + align:start position:0% +code has various symmetries that allow + + + align:start position:0% +code has various symmetries that allow +actually something called the fast for + + align:start position:0% +actually something called the fast for + + + align:start position:0% +actually something called the fast for +transform to be used in the decoding. + + align:start position:0% +transform to be used in the decoding. + + + align:start position:0% +transform to be used in the decoding. +And um uh so that's really uh + + align:start position:0% +And um uh so that's really uh + + + align:start position:0% +And um uh so that's really uh +what drove this. + + align:start position:0% +what drove this. + + + align:start position:0% +what drove this. +Now, as you read about these probes, + + align:start position:0% +Now, as you read about these probes, + + + align:start position:0% +Now, as you read about these probes, +it's actually staggering how much they + + align:start position:0% +it's actually staggering how much they + + + align:start position:0% +it's actually staggering how much they +did with so little. Um let's see. This + + align:start position:0% +did with so little. Um let's see. This + + + align:start position:0% +did with so little. Um let's see. This +thing went half a billion miles almost. + + align:start position:0% +thing went half a billion miles almost. + + + align:start position:0% +thing went half a billion miles almost. +It had an onboard computer with a memory + + align:start position:0% +It had an onboard computer with a memory + + + align:start position:0% +It had an onboard computer with a memory +of 512 words, right? So you can imagine + + align:start position:0% +of 512 words, right? So you can imagine + + + align:start position:0% +of 512 words, right? So you can imagine +the kind of engineering that went into + + align:start position:0% +the kind of engineering that went into + + + align:start position:0% +the kind of engineering that went into +uh organizing all this. um the + + align:start position:0% +uh organizing all this. um the + + + align:start position:0% +uh organizing all this. um the +transmitters and this is typical of + + align:start position:0% +transmitters and this is typical of + + + align:start position:0% +transmitters and this is typical of +these space probes. You can't put uh you + + align:start position:0% +these space probes. You can't put uh you + + + align:start position:0% +these space probes. You can't put uh you +don't have uh lots of energy generated + + align:start position:0% +don't have uh lots of energy generated + + + align:start position:0% +don't have uh lots of energy generated +from uh your solar panels necessarily. + + align:start position:0% +from uh your solar panels necessarily. + + + align:start position:0% +from uh your solar panels necessarily. +So 20 watt transmitters. So these have + + align:start position:0% +So 20 watt transmitters. So these have + + + align:start position:0% +So 20 watt transmitters. So these have +to transmit over this kind of distance + + align:start position:0% +to transmit over this kind of distance + + + align:start position:0% +to transmit over this kind of distance +uh the data that you want to send uh in + + align:start position:0% +uh the data that you want to send uh in + + + align:start position:0% +uh the data that you want to send uh in +the presence of noise and various other + + align:start position:0% +the presence of noise and various other + + + align:start position:0% +the presence of noise and various other +errors. Okay. So + + align:start position:0% +errors. Okay. So + + + align:start position:0% +errors. Okay. So +quite an engineering feat. Now, the + + align:start position:0% +quite an engineering feat. Now, the + + + align:start position:0% +quite an engineering feat. Now, the +kinds of pictures that you would get, + + align:start position:0% +kinds of pictures that you would get, + + + align:start position:0% +kinds of pictures that you would get, +well, these are pretty amazing, + + align:start position:0% +well, these are pretty amazing, + + + align:start position:0% +well, these are pretty amazing, +actually, considering what the uh probes + + align:start position:0% +actually, considering what the uh probes + + + align:start position:0% +actually, considering what the uh probes +had to do. So, over the lifetime, it + + align:start position:0% +had to do. So, over the lifetime, it + + + align:start position:0% +had to do. So, over the lifetime, it +sent over 7,000 images. Mariner 9 is + + align:start position:0% +sent over 7,000 images. Mariner 9 is + + + align:start position:0% +sent over 7,000 images. Mariner 9 is +still orbiting Mars from what I + + align:start position:0% +still orbiting Mars from what I + + + align:start position:0% +still orbiting Mars from what I +understand. It's not sending back, it + + align:start position:0% +understand. It's not sending back, it + + + align:start position:0% +understand. It's not sending back, it +stopped sending back transmissions uh + + align:start position:0% +stopped sending back transmissions uh + + + align:start position:0% +stopped sending back transmissions uh +one or two years after this, but it's + + align:start position:0% +one or two years after this, but it's + + + align:start position:0% +one or two years after this, but it's +still in orbit till it's um till it + + align:start position:0% +still in orbit till it's um till it + + + align:start position:0% +still in orbit till it's um till it +slows down enough to uh crash in. + + align:start position:0% +slows down enough to uh crash in. + + + align:start position:0% +slows down enough to uh crash in. +Okay. So, + + align:start position:0% +Okay. So, + + + align:start position:0% +Okay. So, +as I said, um you're typically talking + + align:start position:0% +as I said, um you're typically talking + + + align:start position:0% +as I said, um you're typically talking +about low power, 20 watts. Uh W MBR, + + align:start position:0% +about low power, 20 watts. Uh W MBR, + + + align:start position:0% +about low power, 20 watts. Uh W MBR, +uh what what's a typical radio station + + align:start position:0% +uh what what's a typical radio station + + + align:start position:0% +uh what what's a typical radio station +power on a college campus. + + align:start position:0% +power on a college campus. + + + align:start position:0% +power on a college campus. +They advertise something on the order of + + align:start position:0% +They advertise something on the order of + + + align:start position:0% +They advertise something on the order of +700 watts for their transmitter, right? + + align:start position:0% +700 watts for their transmitter, right? + + + align:start position:0% +700 watts for their transmitter, right? +So, um we're we're talking about doing a + + align:start position:0% +So, um we're we're talking about doing a + + + align:start position:0% +So, um we're we're talking about doing a +lot with a little here. uh a lot of the + + align:start position:0% +lot with a little here. uh a lot of the + + + align:start position:0% +lot with a little here. uh a lot of the +uh art is in the antenna. So you have an + + align:start position:0% +uh art is in the antenna. So you have an + + + align:start position:0% +uh art is in the antenna. So you have an +antenna that directs this power very + + align:start position:0% +antenna that directs this power very + + + align:start position:0% +antenna that directs this power very +sharply towards the intended receiver, + + align:start position:0% +sharply towards the intended receiver, + + + align:start position:0% +sharply towards the intended receiver, +but the more sharply you try to direct + + align:start position:0% +but the more sharply you try to direct + + + align:start position:0% +but the more sharply you try to direct +that, the bigger of a control problem + + align:start position:0% +that, the bigger of a control problem + + + align:start position:0% +that, the bigger of a control problem +you have because you've got to point + + align:start position:0% +you have because you've got to point + + + align:start position:0% +you have because you've got to point +that antenna all that more carefully. So + + align:start position:0% +that antenna all that more carefully. So + + + align:start position:0% +that antenna all that more carefully. So +all of these are coupled issues. And + + align:start position:0% +all of these are coupled issues. And + + + align:start position:0% +all of these are coupled issues. And +then at the receiver end, you've got um + + align:start position:0% +then at the receiver end, you've got um + + + align:start position:0% +then at the receiver end, you've got um +very high quality uh amplifiers and + + align:start position:0% +very high quality uh amplifiers and + + + align:start position:0% +very high quality uh amplifiers and +signal processing, but the data coding + + align:start position:0% +signal processing, but the data coding + + + align:start position:0% +signal processing, but the data coding +and error correction schemes are a key + + align:start position:0% +and error correction schemes are a key + + + align:start position:0% +and error correction schemes are a key +part of that. And it turns out that as + + align:start position:0% +part of that. And it turns out that as + + + align:start position:0% +part of that. And it turns out that as +you got more ambitious with these + + align:start position:0% +you got more ambitious with these + + + align:start position:0% +you got more ambitious with these +transmissions, you had to go to more + + align:start position:0% +transmissions, you had to go to more + + + align:start position:0% +transmissions, you had to go to more +complicated codes. And these are the + + align:start position:0% +complicated codes. And these are the + + + align:start position:0% +complicated codes. And these are the +codes we're going to talk about uh + + align:start position:0% +codes we're going to talk about uh + + + align:start position:0% +codes we're going to talk about uh +today, what are called convolutional + + align:start position:0% +today, what are called convolutional + + + align:start position:0% +today, what are called convolutional +codes. We'll talk about the coding + + align:start position:0% +codes. We'll talk about the coding + + + align:start position:0% +codes. We'll talk about the coding +today. And then we'll talk about the + + align:start position:0% +today. And then we'll talk about the + + + align:start position:0% +today. And then we'll talk about the +decoding with what's called the Vurby + + align:start position:0% +decoding with what's called the Vurby + + + align:start position:0% +decoding with what's called the Vurby +algorithm um next lecture. So this has + + align:start position:0% +algorithm um next lecture. So this has + + + align:start position:0% +algorithm um next lecture. So this has +been used extensively + + align:start position:0% +been used extensively + + + align:start position:0% +been used extensively +uh from the late 1970s onwards. More + + align:start position:0% +uh from the late 1970s onwards. More + + + align:start position:0% +uh from the late 1970s onwards. More +recently you have um codes that are + + align:start position:0% +recently you have um codes that are + + + align:start position:0% +recently you have um codes that are +actually combinations of convolutional + + align:start position:0% +actually combinations of convolutional + + + align:start position:0% +actually combinations of convolutional +codes what are called turbo codes and uh + + align:start position:0% +codes what are called turbo codes and uh + + + align:start position:0% +codes what are called turbo codes and uh +another family of codes low density + + align:start position:0% +another family of codes low density + + + align:start position:0% +another family of codes low density +parity check codes which were uh + + align:start position:0% +parity check codes which were uh + + + align:start position:0% +parity check codes which were uh +developed in Bob Gallagher's u PhD + + align:start position:0% +developed in Bob Gallagher's u PhD + + + align:start position:0% +developed in Bob Gallagher's u PhD +thesis here Bob Gallagher is on our + + align:start position:0% +thesis here Bob Gallagher is on our + + + align:start position:0% +thesis here Bob Gallagher is on our +faculty um + + align:start position:0% +faculty um + + + align:start position:0% +faculty um +but convolutional codes were really a + + align:start position:0% +but convolutional codes were really a + + + align:start position:0% +but convolutional codes were really a +workhorse of uh the whole system okay so + + align:start position:0% +workhorse of uh the whole system okay so + + + align:start position:0% +workhorse of uh the whole system okay so +u an example is now Cassini which is in + + align:start position:0% +u an example is now Cassini which is in + + + align:start position:0% +u an example is now Cassini which is in +orbit around Saturn. It's actively + + align:start position:0% +orbit around Saturn. It's actively + + + align:start position:0% +orbit around Saturn. It's actively +sending pictures. This if I read the uh + + align:start position:0% +sending pictures. This if I read the uh + + + align:start position:0% +sending pictures. This if I read the uh +website correctly is a picture from + + align:start position:0% +website correctly is a picture from + + + align:start position:0% +website correctly is a picture from +August 29th and I saw the pictures + + align:start position:0% +August 29th and I saw the pictures + + + align:start position:0% +August 29th and I saw the pictures +posted from June and July. Uh so this is + + align:start position:0% +posted from June and July. Uh so this is + + + align:start position:0% +posted from June and July. Uh so this is +a picture of one of Saturn's moons and + + align:start position:0% +a picture of one of Saturn's moons and + + + align:start position:0% +a picture of one of Saturn's moons and +you can see the rings and the shadows of + + align:start position:0% +you can see the rings and the shadows of + + + align:start position:0% +you can see the rings and the shadows of +the rings and so on. Uh this is actually + + align:start position:0% +the rings and so on. Uh this is actually + + + align:start position:0% +the rings and so on. Uh this is actually +recreated in natural color for multiple + + align:start position:0% +recreated in natural color for multiple + + + align:start position:0% +recreated in natural color for multiple +uh images. + + align:start position:0% + + + + align:start position:0% + +This, I guess, is part picture and part + + align:start position:0% +This, I guess, is part picture and part + + + align:start position:0% +This, I guess, is part picture and part +artist rendition, but that shows you + + align:start position:0% +artist rendition, but that shows you + + + align:start position:0% +artist rendition, but that shows you +what Cassini looks like. There's only + + align:start position:0% +what Cassini looks like. There's only + + + align:start position:0% +what Cassini looks like. There's only +one of them out there. I don't think + + align:start position:0% +one of them out there. I don't think + + + align:start position:0% +one of them out there. I don't think +there's something else to photograph + + align:start position:0% +there's something else to photograph + + + align:start position:0% +there's something else to photograph +Cassini. + + align:start position:0% +Cassini. + + + align:start position:0% +Cassini. +So, uh, the kind of code that's used is + + align:start position:0% +So, uh, the kind of code that's used is + + + align:start position:0% +So, uh, the kind of code that's used is +a convolutional code. We'll learn what + + align:start position:0% +a convolutional code. We'll learn what + + + align:start position:0% +a convolutional code. We'll learn what +uh these parameters mean, how they enter + + align:start position:0% +uh these parameters mean, how they enter + + + align:start position:0% +uh these parameters mean, how they enter +into the definition of the code. And + + align:start position:0% +into the definition of the code. And + + + align:start position:0% +into the definition of the code. And +here is a typical uh code rate. you're + + align:start position:0% +here is a typical uh code rate. you're + + + align:start position:0% +here is a typical uh code rate. you're +talking about something on the order of + + align:start position:0% +talking about something on the order of + + + align:start position:0% +talking about something on the order of +uh 83,000 bits per second as the code + + align:start position:0% +uh 83,000 bits per second as the code + + + align:start position:0% +uh 83,000 bits per second as the code +rate here. Uh the um sorry not the code + + align:start position:0% +rate here. Uh the um sorry not the code + + + align:start position:0% +rate here. Uh the um sorry not the code +rate this is the data rate. Okay. So the + + align:start position:0% +rate this is the data rate. Okay. So the + + + align:start position:0% +rate this is the data rate. Okay. So the +um the um messages are coming um + + align:start position:0% +um the um messages are coming um + + + align:start position:0% +um the um messages are coming um +uh let's see yeah you're sending six + + align:start position:0% +uh let's see yeah you're sending six + + + align:start position:0% +uh let's see yeah you're sending six +times this amount per second but this is + + align:start position:0% +times this amount per second but this is + + + align:start position:0% +times this amount per second but this is +the rate at which the data is coming in. + + align:start position:0% +the rate at which the data is coming in. + + + align:start position:0% +the rate at which the data is coming in. +Okay, + + align:start position:0% + + + + align:start position:0% + +so convolutional codes and again I keep + + align:start position:0% +so convolutional codes and again I keep + + + align:start position:0% +so convolutional codes and again I keep +coming back to MIT names. Peter Elias + + align:start position:0% +coming back to MIT names. Peter Elias + + + align:start position:0% +coming back to MIT names. Peter Elias +was on our uh faculty here. He was a + + align:start position:0% +was on our uh faculty here. He was a + + + align:start position:0% +was on our uh faculty here. He was a +department head for a while and uh in a + + align:start position:0% +department head for a while and uh in a + + + align:start position:0% +department head for a while and uh in a +short uh paper in 1955 + + align:start position:0% +short uh paper in 1955 + + + align:start position:0% +short uh paper in 1955 +invented the idea of convolutional + + align:start position:0% +invented the idea of convolutional + + + align:start position:0% +invented the idea of convolutional +codes. So the idea here is um not to + + align:start position:0% +codes. So the idea here is um not to + + + align:start position:0% +codes. So the idea here is um not to +divide up your data into blocks uh but + + align:start position:0% +divide up your data into blocks uh but + + + align:start position:0% +divide up your data into blocks uh but +to actually work on the streaming data + + align:start position:0% +to actually work on the streaming data + + + align:start position:0% +to actually work on the streaming data +and as the data goes past you generate + + align:start position:0% +and as the data goes past you generate + + + align:start position:0% +and as the data goes past you generate +par bits uh at a regular rate and what + + align:start position:0% +par bits uh at a regular rate and what + + + align:start position:0% +par bits uh at a regular rate and what +you transmit in most typical schemes are + + align:start position:0% +you transmit in most typical schemes are + + + align:start position:0% +you transmit in most typical schemes are +just the par bits. You don't send the + + align:start position:0% +just the par bits. You don't send the + + + align:start position:0% +just the par bits. You don't send the +message bits. So this would be a + + align:start position:0% +message bits. So this would be a + + + align:start position:0% +message bits. So this would be a +non-sistatic code if you like. So you're + + align:start position:0% +non-sistatic code if you like. So you're + + + align:start position:0% +non-sistatic code if you like. So you're +not there's no part of that message + + align:start position:0% +not there's no part of that message + + + align:start position:0% +not there's no part of that message +that's directly observing the uh the + + align:start position:0% +that's directly observing the uh the + + + align:start position:0% +that's directly observing the uh the +message bits. Um + + align:start position:0% +message bits. Um + + + align:start position:0% +message bits. Um +now uh you you will actually generate + + align:start position:0% +now uh you you will actually generate + + + align:start position:0% +now uh you you will actually generate +and send multiple + + align:start position:0% + + + + align:start position:0% + +multiple par bits. So you'll have a + + align:start position:0% +multiple par bits. So you'll have a + + + align:start position:0% +multiple par bits. So you'll have a +message uh sequence + + align:start position:0% + + + + align:start position:0% + +x0 xn + + align:start position:0% +x0 xn + + + align:start position:0% +x0 xn +sorry x0 x1 + + align:start position:0% + + + + align:start position:0% + +and from this you derive um parity bits + + align:start position:0% +and from this you derive um parity bits + + + align:start position:0% +and from this you derive um parity bits +and you do that using the standard sorts + + align:start position:0% +and you do that using the standard sorts + + + align:start position:0% +and you do that using the standard sorts +of equations we've seen with blog codes. + + align:start position:0% +of equations we've seen with blog codes. + + + align:start position:0% +of equations we've seen with blog codes. +Each par bit here uh for instance par + + align:start position:0% +Each par bit here uh for instance par + + + align:start position:0% +Each par bit here uh for instance par +bit zero at time n will be some linear + + align:start position:0% +bit zero at time n will be some linear + + + align:start position:0% +bit zero at time n will be some linear +combination of message bits but it's the + + align:start position:0% +combination of message bits but it's the + + + align:start position:0% +combination of message bits but it's the +message bits as they're streaming by. So + + align:start position:0% +message bits as they're streaming by. So + + + align:start position:0% +message bits as they're streaming by. So +you might have for instance + + align:start position:0% +you might have for instance + + + align:start position:0% +you might have for instance +this as your choice for uh parity bit + + align:start position:0% +this as your choice for uh parity bit + + + align:start position:0% +this as your choice for uh parity bit +number zero. + + align:start position:0% + + + + align:start position:0% + +Okay. And then uh parity bit number one + + align:start position:0% +Okay. And then uh parity bit number one + + + align:start position:0% +Okay. And then uh parity bit number one +could be some other combination here. So + + align:start position:0% +could be some other combination here. So + + + align:start position:0% +could be some other combination here. So +for instance xn plus + + align:start position:0% + + + + align:start position:0% + +xn minus2 for instance. Okay. So it's a + + align:start position:0% +xn minus2 for instance. Okay. So it's a + + + align:start position:0% +xn minus2 for instance. Okay. So it's a +linear combination of some set of set of + + align:start position:0% +linear combination of some set of set of + + + align:start position:0% +linear combination of some set of set of +message bits just the way we've been + + align:start position:0% +message bits just the way we've been + + + align:start position:0% +message bits just the way we've been +generating parity bits all along. Uh the + + align:start position:0% +generating parity bits all along. Uh the + + + align:start position:0% +generating parity bits all along. Uh the +the plus here of course is we're talking + + align:start position:0% +the plus here of course is we're talking + + + align:start position:0% +the plus here of course is we're talking +about binary uh messages. So this is + + align:start position:0% +about binary uh messages. So this is + + + align:start position:0% +about binary uh messages. So this is +addition in GF2. So it's um exclusive or + + align:start position:0% + + + + align:start position:0% + +or modulo 2 addition + + align:start position:0% +or modulo 2 addition + + + align:start position:0% +or modulo 2 addition +and you can imagine a whole bunch of + + align:start position:0% +and you can imagine a whole bunch of + + + align:start position:0% +and you can imagine a whole bunch of +such parity bits. So in general you + + align:start position:0% +such parity bits. So in general you + + + align:start position:0% +such parity bits. So in general you +would have r such parity bits computed + + align:start position:0% +would have r such parity bits computed + + + align:start position:0% +would have r such parity bits computed +off some set of message bits and + + align:start position:0% +off some set of message bits and + + + align:start position:0% +off some set of message bits and +transmitted instead of the message bits. + + align:start position:0% +transmitted instead of the message bits. + + + align:start position:0% +transmitted instead of the message bits. +So you might have in for each message + + align:start position:0% +So you might have in for each message + + + align:start position:0% +So you might have in for each message +bit coming in uh you might actually be + + align:start position:0% +bit coming in uh you might actually be + + + align:start position:0% +bit coming in uh you might actually be +sending out R parity bits. So what you'd + + align:start position:0% +sending out R parity bits. So what you'd + + + align:start position:0% +sending out R parity bits. So what you'd +do is just send these out in sequence. + + align:start position:0% +do is just send these out in sequence. + + + align:start position:0% +do is just send these out in sequence. +You'd send out the P 0 value, the P1 + + align:start position:0% +You'd send out the P 0 value, the P1 + + + align:start position:0% +You'd send out the P 0 value, the P1 +value at time N, then recomputee at time + + align:start position:0% +value at time N, then recomputee at time + + + align:start position:0% +value at time N, then recomputee at time +N plus one and keep going. All right. + + align:start position:0% +N plus one and keep going. All right. + + + align:start position:0% +N plus one and keep going. All right. +Oh, actually I have them here. I didn't + + align:start position:0% +Oh, actually I have them here. I didn't + + + align:start position:0% +Oh, actually I have them here. I didn't +see that. + + align:start position:0% +see that. + + + align:start position:0% +see that. +Uh so all this happens on a sliding + + align:start position:0% +Uh so all this happens on a sliding + + + align:start position:0% +Uh so all this happens on a sliding +window. This happens for a particular + + align:start position:0% +window. This happens for a particular + + + align:start position:0% +window. This happens for a particular +choice of n. Then it happens for the + + align:start position:0% +choice of n. Then it happens for the + + + align:start position:0% +choice of n. Then it happens for the +next choice of n and the next choice of + + align:start position:0% +next choice of n and the next choice of + + + align:start position:0% +next choice of n and the next choice of +n. So you're doing this on the fly with + + align:start position:0% +n. So you're doing this on the fly with + + + align:start position:0% +n. So you're doing this on the fly with +a streaming uh sequence, right? + + align:start position:0% + + + + align:start position:0% + +Uh so let me just + + align:start position:0% +Uh so let me just + + + align:start position:0% +Uh so let me just +put up an equation that explains + + align:start position:0% +put up an equation that explains + + + align:start position:0% +put up an equation that explains +why this is called a convolutional code. + + align:start position:0% +why this is called a convolutional code. + + + align:start position:0% +why this is called a convolutional code. +It turns out that expressions of this + + align:start position:0% +It turns out that expressions of this + + + align:start position:0% +It turns out that expressions of this +type where you take a data stream coming + + align:start position:0% +type where you take a data stream coming + + + align:start position:0% +type where you take a data stream coming +in and generate uh new data streams of + + align:start position:0% +in and generate uh new data streams of + + + align:start position:0% +in and generate uh new data streams of +this form. It turns out that the + + align:start position:0% +this form. It turns out that the + + + align:start position:0% +this form. It turns out that the +operation that's being carried out here + + align:start position:0% +operation that's being carried out here + + + align:start position:0% +operation that's being carried out here +is something referred to as convolution. + + align:start position:0% +is something referred to as convolution. + + + align:start position:0% +is something referred to as convolution. +So in general um what is P 0 of N? It's + + align:start position:0% +So in general um what is P 0 of N? It's + + + align:start position:0% +So in general um what is P 0 of N? It's +some weighted combination + + align:start position:0% +some weighted combination + + + align:start position:0% +some weighted combination +of X at the current time, X1 time step + + align:start position:0% +of X at the current time, X1 time step + + + align:start position:0% +of X at the current time, X1 time step +back, X2 time steps back. um in general + + align:start position:0% +back, X2 time steps back. um in general + + + align:start position:0% +back, X2 time steps back. um in general +uh k different uh values involved. So + + align:start position:0% +uh k different uh values involved. So + + + align:start position:0% +uh k different uh values involved. So +what I have is P 0 N + + align:start position:0% +what I have is P 0 N + + + align:start position:0% +what I have is P 0 N +being a summation from U let's say J + + align:start position:0% +being a summation from U let's say J + + + align:start position:0% +being a summation from U let's say J +equals Z + + align:start position:0% + + + + align:start position:0% + +of + + align:start position:0% +of + + + align:start position:0% +of +say + + align:start position:0% +say + + + align:start position:0% +say +G0 J um X of N minus J. All right. So + + align:start position:0% +G0 J um X of N minus J. All right. So + + + align:start position:0% +G0 J um X of N minus J. All right. So +this is just some set of numbers 0 or + + align:start position:0% +this is just some set of numbers 0 or + + + align:start position:0% +this is just some set of numbers 0 or +one just as these bits are these are + + align:start position:0% +one just as these bits are these are + + + align:start position:0% +one just as these bits are these are +zero or one + + align:start position:0% +zero or one + + + align:start position:0% +zero or one +but this is the general form right + + align:start position:0% + + + + align:start position:0% + +this particular kind of combination is + + align:start position:0% +this particular kind of combination is + + + align:start position:0% +this particular kind of combination is +referred to as a convolution operation + + align:start position:0% +referred to as a convolution operation + + + align:start position:0% +referred to as a convolution operation +on the input stream and we'll see much + + align:start position:0% +on the input stream and we'll see much + + + align:start position:0% +on the input stream and we'll see much +more of this when we come later to + + align:start position:0% +more of this when we come later to + + + align:start position:0% +more of this when we come later to +modeling um uh channels via physical + + align:start position:0% +modeling um uh channels via physical + + + align:start position:0% +modeling um uh channels via physical +channels we'll talk about convolution + + align:start position:0% +channels we'll talk about convolution + + + align:start position:0% +channels we'll talk about convolution +type models. So here it's not so + + align:start position:0% +type models. So here it's not so + + + align:start position:0% +type models. So here it's not so +important that you master this + + align:start position:0% +important that you master this + + + align:start position:0% +important that you master this +expression. We'll have plenty of + + align:start position:0% +expression. We'll have plenty of + + + align:start position:0% +expression. We'll have plenty of +opportunity to work with expressions + + align:start position:0% +opportunity to work with expressions + + + align:start position:0% +opportunity to work with expressions +like this. It's just for you to know + + align:start position:0% +like this. It's just for you to know + + + align:start position:0% +like this. It's just for you to know +that an expression of this type wherever + + align:start position:0% +that an expression of this type wherever + + + align:start position:0% +that an expression of this type wherever +you see a summation with indices that + + align:start position:0% +you see a summation with indices that + + + align:start position:0% +you see a summation with indices that +are in this form uh this is referred to + + align:start position:0% +are in this form uh this is referred to + + + align:start position:0% +are in this form uh this is referred to +as a convolution. Okay. + + align:start position:0% + + + + align:start position:0% + +So it's convolution of the message + + align:start position:0% +So it's convolution of the message + + + align:start position:0% +So it's convolution of the message +stream + + align:start position:0% +stream + + + align:start position:0% +stream +with uh some + + align:start position:0% +with uh some + + + align:start position:0% +with uh some +set of weights. + + align:start position:0% +set of weights. + + + align:start position:0% +set of weights. +Professor + + align:start position:0% +Professor + + + align:start position:0% +Professor +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +What does G stand for? + + align:start position:0% +What does G stand for? + + + align:start position:0% +What does G stand for? +Uh the G is just a set of weights here. + + align:start position:0% +Uh the G is just a set of weights here. + + + align:start position:0% +Uh the G is just a set of weights here. +So in this particular case for parity + + align:start position:0% +So in this particular case for parity + + + align:start position:0% +So in this particular case for parity +expression zero um uh G0 of one G0 of 0 + + align:start position:0% +expression zero um uh G0 of one G0 of 0 + + + align:start position:0% +expression zero um uh G0 of one G0 of 0 +would be one. G 01 would be one. G 02 + + align:start position:0% +would be one. G 01 would be one. G 02 + + + align:start position:0% +would be one. G 01 would be one. G 02 +would be one. Okay. It's just a set of + + align:start position:0% +would be one. Okay. It's just a set of + + + align:start position:0% +would be one. Okay. It's just a set of +weights. + + align:start position:0% + + + + align:start position:0% + +So yeah, this expression is a bit of + + align:start position:0% +So yeah, this expression is a bit of + + + align:start position:0% +So yeah, this expression is a bit of +overkill for the kind of uh use we're + + align:start position:0% +overkill for the kind of uh use we're + + + align:start position:0% +overkill for the kind of uh use we're +making of it, but it's just to uh + + align:start position:0% +making of it, but it's just to uh + + + align:start position:0% +making of it, but it's just to uh +explain the origin of the name. It turns + + align:start position:0% +explain the origin of the name. It turns + + + align:start position:0% +explain the origin of the name. It turns +out later when we use it for channel + + align:start position:0% +out later when we use it for channel + + + align:start position:0% +out later when we use it for channel +modeling, the x's will not just be zeros + + align:start position:0% +modeling, the x's will not just be zeros + + + align:start position:0% +modeling, the x's will not just be zeros +or ones. They could take arbitrary real + + align:start position:0% +or ones. They could take arbitrary real + + + align:start position:0% +or ones. They could take arbitrary real +values and the g's could take arbitrary + + align:start position:0% +values and the g's could take arbitrary + + + align:start position:0% +values and the g's could take arbitrary +real values. So we'll be working with + + align:start position:0% +real values. So we'll be working with + + + align:start position:0% +real values. So we'll be working with +much more elaborate versions of this. + + align:start position:0% +much more elaborate versions of this. + + + align:start position:0% +much more elaborate versions of this. +Okay. + + align:start position:0% + + + + align:start position:0% + +The number k + + align:start position:0% +The number k + + + align:start position:0% +The number k +is referred to as the constraint length + + align:start position:0% +is referred to as the constraint length + + + align:start position:0% +is referred to as the constraint length +and it's the maximum number of message + + align:start position:0% +and it's the maximum number of message + + + align:start position:0% +and it's the maximum number of message +bits involved when you look over all + + align:start position:0% +bits involved when you look over all + + + align:start position:0% +bits involved when you look over all +your parity expressions. So in this + + align:start position:0% +your parity expressions. So in this + + + align:start position:0% +your parity expressions. So in this +particular instance uh k would be equal + + align:start position:0% +particular instance uh k would be equal + + + align:start position:0% +particular instance uh k would be equal +to three right it's the maximum window + + align:start position:0% +to three right it's the maximum window + + + align:start position:0% +to three right it's the maximum window +uh of data that you're using in a + + align:start position:0% +uh of data that you're using in a + + + align:start position:0% +uh of data that you're using in a +non-trivial way to generate the bits. So + + align:start position:0% +non-trivial way to generate the bits. So + + + align:start position:0% +non-trivial way to generate the bits. So +here you're using up to uh three to + + align:start position:0% +here you're using up to uh three to + + + align:start position:0% +here you're using up to uh three to +generate this. Well in this case also + + align:start position:0% +generate this. Well in this case also + + + align:start position:0% +generate this. Well in this case also +you're using a window of three message + + align:start position:0% +you're using a window of three message + + + align:start position:0% +you're using a window of three message +bits. It happens that you're ignoring + + align:start position:0% +bits. It happens that you're ignoring + + + align:start position:0% +bits. It happens that you're ignoring +the one in the center but the constraint + + align:start position:0% +the one in the center but the constraint + + + align:start position:0% +the one in the center but the constraint +length is the uh the length of message + + align:start position:0% +length is the uh the length of message + + + align:start position:0% +length is the uh the length of message +that you're actually looking at. + + align:start position:0% +that you're actually looking at. + + + align:start position:0% +that you're actually looking at. +Okay. Um + + align:start position:0% +Okay. Um + + + align:start position:0% +Okay. Um +so in some sense if you want to think of + + align:start position:0% +so in some sense if you want to think of + + + align:start position:0% +so in some sense if you want to think of +it this way the um the number of parity + + align:start position:0% +it this way the um the number of parity + + + align:start position:0% +it this way the um the number of parity +expressions that you use well that's + + align:start position:0% +expressions that you use well that's + + + align:start position:0% +expressions that you use well that's +straightforward that's just telling you + + align:start position:0% +straightforward that's just telling you + + + align:start position:0% +straightforward that's just telling you +how much redundancy you're willing to + + align:start position:0% +how much redundancy you're willing to + + + align:start position:0% +how much redundancy you're willing to +put in. Whereas the constraint length is + + align:start position:0% +put in. Whereas the constraint length is + + + align:start position:0% +put in. Whereas the constraint length is +telling you how deeply you're folding + + align:start position:0% +telling you how deeply you're folding + + + align:start position:0% +telling you how deeply you're folding +that redundancy into the message. So the + + align:start position:0% +that redundancy into the message. So the + + + align:start position:0% +that redundancy into the message. So the +bigger the constraint length, the more + + align:start position:0% +bigger the constraint length, the more + + + align:start position:0% +bigger the constraint length, the more +message bits are involved in generating + + align:start position:0% +message bits are involved in generating + + + align:start position:0% +message bits are involved in generating +a par bit. And so the more you're + + align:start position:0% +a par bit. And so the more you're + + + align:start position:0% +a par bit. And so the more you're +scrambling up the message and spreading + + align:start position:0% +scrambling up the message and spreading + + + align:start position:0% +scrambling up the message and spreading +it over a large section of what's + + align:start position:0% +it over a large section of what's + + + align:start position:0% +it over a large section of what's +transmitted. And so you might expect + + align:start position:0% +transmitted. And so you might expect + + + align:start position:0% +transmitted. And so you might expect +that you get better error correction + + align:start position:0% +that you get better error correction + + + align:start position:0% +that you get better error correction +properties with larger constraint + + align:start position:0% +properties with larger constraint + + + align:start position:0% +properties with larger constraint +lengths. Okay. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +This is not saying + + align:start position:0% +This is not saying + + + align:start position:0% +This is not saying +anything new? So, + + align:start position:0% + + + + align:start position:0% + +so how do we come to actually + + align:start position:0% +so how do we come to actually + + + align:start position:0% +so how do we come to actually +transmitting? Well, we generate the par + + align:start position:0% +transmitting? Well, we generate the par + + + align:start position:0% +transmitting? Well, we generate the par +bits and then as I said, you send all + + align:start position:0% +bits and then as I said, you send all + + + align:start position:0% +bits and then as I said, you send all +the par bits associated with your + + align:start position:0% +the par bits associated with your + + + align:start position:0% +the par bits associated with your +computation at time zero. Then all the + + align:start position:0% +computation at time zero. Then all the + + + align:start position:0% +computation at time zero. Then all the +par bits associated with the computation + + align:start position:0% +par bits associated with the computation + + + align:start position:0% +par bits associated with the computation +at time one, time two and so on. + + align:start position:0% +at time one, time two and so on. + + + align:start position:0% +at time one, time two and so on. +So in the case of the um code used on + + align:start position:0% +So in the case of the um code used on + + + align:start position:0% +So in the case of the um code used on +the Cassini probe, that's a one over six + + align:start position:0% +the Cassini probe, that's a one over six + + + align:start position:0% +the Cassini probe, that's a one over six +rate code. It's actually computing six + + align:start position:0% +rate code. It's actually computing six + + + align:start position:0% +rate code. It's actually computing six +par expressions. So it's transmitting + + align:start position:0% +par expressions. So it's transmitting + + + align:start position:0% +par expressions. So it's transmitting +six par bits for each message bit that + + align:start position:0% +six par bits for each message bit that + + + align:start position:0% +six par bits for each message bit that +comes in. Uh what happens then at the + + align:start position:0% +comes in. Uh what happens then at the + + + align:start position:0% +comes in. Uh what happens then at the +next time instant is that you shift + + align:start position:0% +next time instant is that you shift + + + align:start position:0% +next time instant is that you shift +everything up by one and uh redo the + + align:start position:0% +everything up by one and uh redo the + + + align:start position:0% +everything up by one and uh redo the +whole thing. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +Now um you can actually and I'll have + + align:start position:0% +Now um you can actually and I'll have + + + align:start position:0% +Now um you can actually and I'll have +this up on the slides. You can actually + + align:start position:0% +this up on the slides. You can actually + + + align:start position:0% +this up on the slides. You can actually +crank through the equations but it's not + + align:start position:0% +crank through the equations but it's not + + + align:start position:0% +crank through the equations but it's not +the most illuminating way to u think of + + align:start position:0% +the most illuminating way to u think of + + + align:start position:0% +the most illuminating way to u think of +things. It's much easier to think of it + + align:start position:0% +things. It's much easier to think of it + + + align:start position:0% +things. It's much easier to think of it +visually through um a block diagram of + + align:start position:0% +visually through um a block diagram of + + + align:start position:0% +visually through um a block diagram of +this type and using the idea of what's + + align:start position:0% +this type and using the idea of what's + + + align:start position:0% +this type and using the idea of what's +called a shift gen shift register. So + + align:start position:0% +called a shift gen shift register. So + + + align:start position:0% +called a shift gen shift register. So +what is a shift register? You may have + + align:start position:0% +what is a shift register? You may have + + + align:start position:0% +what is a shift register? You may have +encountered it in other places. + + align:start position:0% + + + + align:start position:0% + +So we think of a shift register as + + align:start position:0% +So we think of a shift register as + + + align:start position:0% +So we think of a shift register as +it's basically u a box that can remember + + align:start position:0% +it's basically u a box that can remember + + + align:start position:0% +it's basically u a box that can remember +something. Okay, that's the register + + align:start position:0% +something. Okay, that's the register + + + align:start position:0% +something. Okay, that's the register +part of it. A register is something that + + align:start position:0% +part of it. A register is something that + + + align:start position:0% +part of it. A register is something that +remembers a number. Um you've got some + + align:start position:0% +remembers a number. Um you've got some + + + align:start position:0% +remembers a number. Um you've got some +input stream that comes in and some + + align:start position:0% +input stream that comes in and some + + + align:start position:0% +input stream that comes in and some +output stream emerging at any time. This + + align:start position:0% +output stream emerging at any time. This + + + align:start position:0% +output stream emerging at any time. This +stores a particular number which is + + align:start position:0% +stores a particular number which is + + + align:start position:0% +stores a particular number which is +available to the output. So whatever + + align:start position:0% +available to the output. So whatever + + + align:start position:0% +available to the output. So whatever +stored in the register is available to + + align:start position:0% +stored in the register is available to + + + align:start position:0% +stored in the register is available to +the output. The shift part of this + + align:start position:0% +the output. The shift part of this + + + align:start position:0% +the output. The shift part of this +description is that whatever's at the + + align:start position:0% +description is that whatever's at the + + + align:start position:0% +description is that whatever's at the +input will get shifted in at the next + + align:start position:0% +input will get shifted in at the next + + + align:start position:0% +input will get shifted in at the next +clock cycle or the next time instant. + + align:start position:0% +clock cycle or the next time instant. + + + align:start position:0% +clock cycle or the next time instant. +Okay? So the input gets shifted in at + + align:start position:0% +Okay? So the input gets shifted in at + + + align:start position:0% +Okay? So the input gets shifted in at +the next clock cycle. Whatever is in + + align:start position:0% +the next clock cycle. Whatever is in + + + align:start position:0% +the next clock cycle. Whatever is in +here is remembered for that one clock + + align:start position:0% +here is remembered for that one clock + + + align:start position:0% +here is remembered for that one clock +cycle and is available at the output. + + align:start position:0% +cycle and is available at the output. + + + align:start position:0% +cycle and is available at the output. +Right? So if I have uh + + align:start position:0% +Right? So if I have uh + + + align:start position:0% +Right? So if I have uh +a sequence xn being fed in for n01 2 3 + + align:start position:0% +a sequence xn being fed in for n01 2 3 + + + align:start position:0% +a sequence xn being fed in for n01 2 3 +and so on. Um if I'm seeing xn here, + + align:start position:0% +and so on. Um if I'm seeing xn here, + + + align:start position:0% +and so on. Um if I'm seeing xn here, +what must have gone into the previous + + align:start position:0% +what must have gone into the previous + + + align:start position:0% +what must have gone into the previous +time? If I see xn here at time n, if I'm + + align:start position:0% +time? If I see xn here at time n, if I'm + + + align:start position:0% +time? If I see xn here at time n, if I'm +seeing a particular input at time n, + + align:start position:0% +seeing a particular input at time n, + + + align:start position:0% +seeing a particular input at time n, +what must have gone in the previous time + + align:start position:0% +what must have gone in the previous time + + + align:start position:0% +what must have gone in the previous time +is x n minus one. So what's sitting here + + align:start position:0% +is x n minus one. So what's sitting here + + + align:start position:0% +is x n minus one. So what's sitting here +is xn minus one, right? and xn minus one + + align:start position:0% +is xn minus one, right? and xn minus one + + + align:start position:0% +is xn minus one, right? and xn minus one +is available to me at the output. The + + align:start position:0% +is available to me at the output. The + + + align:start position:0% +is available to me at the output. The +next clock cycle, the next input comes + + align:start position:0% +next clock cycle, the next input comes + + + align:start position:0% +next clock cycle, the next input comes +along, the xn goes in here and uh it the + + align:start position:0% +along, the xn goes in here and uh it the + + + align:start position:0% +along, the xn goes in here and uh it the +whole thing shifts. All right? Now, what + + align:start position:0% +whole thing shifts. All right? Now, what + + + align:start position:0% +whole thing shifts. All right? Now, what +you have up there is a cascade of shift + + align:start position:0% +you have up there is a cascade of shift + + + align:start position:0% +you have up there is a cascade of shift +registers. You've got two shift + + align:start position:0% +registers. You've got two shift + + + align:start position:0% +registers. You've got two shift +registers. + + align:start position:0% +registers. + + + align:start position:0% +registers. +If you keep in mind the operation that I + + align:start position:0% +If you keep in mind the operation that I + + + align:start position:0% +If you keep in mind the operation that I +described, if this is xn, if I'm looking + + align:start position:0% +described, if this is xn, if I'm looking + + + align:start position:0% +described, if this is xn, if I'm looking +at this at time n, xn sitting here, what + + align:start position:0% +at this at time n, xn sitting here, what + + + align:start position:0% +at this at time n, xn sitting here, what +must be in this shift register is the + + align:start position:0% +must be in this shift register is the + + + align:start position:0% +must be in this shift register is the +input of the previous time. So that's xn + + align:start position:0% +input of the previous time. So that's xn + + + align:start position:0% +input of the previous time. So that's xn +minus one. Uh this these are shown + + align:start position:0% +minus one. Uh this these are shown + + + align:start position:0% +minus one. Uh this these are shown +adjacent. What we really mean is that + + align:start position:0% +adjacent. What we really mean is that + + + align:start position:0% +adjacent. What we really mean is that +one shift register is feeding into the + + align:start position:0% +one shift register is feeding into the + + + align:start position:0% +one shift register is feeding into the +next one. They're just shown as + + align:start position:0% +next one. They're just shown as + + + align:start position:0% +next one. They're just shown as +adjacent. But what must be sitting here + + align:start position:0% +adjacent. But what must be sitting here + + + align:start position:0% +adjacent. But what must be sitting here +then is xn minus 2. Okay? And if I read + + align:start position:0% +then is xn minus 2. Okay? And if I read + + + align:start position:0% +then is xn minus 2. Okay? And if I read +off something from here, what's what I'm + + align:start position:0% +off something from here, what's what I'm + + + align:start position:0% +off something from here, what's what I'm +looking at is xn minus one. Namely, + + align:start position:0% +looking at is xn minus one. Namely, + + + align:start position:0% +looking at is xn minus one. Namely, +what's sitting in the register? What I'm + + align:start position:0% +what's sitting in the register? What I'm + + + align:start position:0% +what's sitting in the register? What I'm +looking at here is xnus 2. + + align:start position:0% + + + + align:start position:0% + +All right. So, do you see how this is + + align:start position:0% +All right. So, do you see how this is + + + align:start position:0% +All right. So, do you see how this is +working now? Um, this is actually the + + align:start position:0% +working now? Um, this is actually the + + + align:start position:0% +working now? Um, this is actually the +same example that I had written up + + align:start position:0% +same example that I had written up + + + align:start position:0% +same example that I had written up +earlier, I guess, for the computational + + align:start position:0% +earlier, I guess, for the computational + + + align:start position:0% +earlier, I guess, for the computational +par bits. So, here's except it's Yeah, + + align:start position:0% +par bits. So, here's except it's Yeah, + + + align:start position:0% +par bits. So, here's except it's Yeah, +it's the same one. P 0 N I have the + + align:start position:0% +it's the same one. P 0 N I have the + + + align:start position:0% +it's the same one. P 0 N I have the +equations. Let's see if I can display + + align:start position:0% +equations. Let's see if I can display + + + align:start position:0% +equations. Let's see if I can display +them for you. + + align:start position:0% +them for you. + + + align:start position:0% +them for you. +No, I don't. Okay. So, what's P 0N? + + align:start position:0% +No, I don't. Okay. So, what's P 0N? + + + align:start position:0% +No, I don't. Okay. So, what's P 0N? +P 0 N is XN that's connecting from here + + align:start position:0% +P 0 N is XN that's connecting from here + + + align:start position:0% +P 0 N is XN that's connecting from here +plus X N minus one plus XN minus 2. + + align:start position:0% +plus X N minus one plus XN minus 2. + + + align:start position:0% +plus X N minus one plus XN minus 2. +Again, by the way, in this diagram, what + + align:start position:0% +Again, by the way, in this diagram, what + + + align:start position:0% +Again, by the way, in this diagram, what +I showed as an arrow coming from the + + align:start position:0% +I showed as an arrow coming from the + + + align:start position:0% +I showed as an arrow coming from the +output of the shift register. There's + + align:start position:0% +output of the shift register. There's + + + align:start position:0% +output of the shift register. There's +just a short hand here that shows the + + align:start position:0% +just a short hand here that shows the + + + align:start position:0% +just a short hand here that shows the +arrow coming out from the body of the + + align:start position:0% +arrow coming out from the body of the + + + align:start position:0% +arrow coming out from the body of the +register. It's the same thing we're + + align:start position:0% +register. It's the same thing we're + + + align:start position:0% +register. It's the same thing we're +talking about. Okay, so P 0 of N is the + + align:start position:0% +talking about. Okay, so P 0 of N is the + + + align:start position:0% +talking about. Okay, so P 0 of N is the +sum of these three message bits. So, + + align:start position:0% +sum of these three message bits. So, + + + align:start position:0% +sum of these three message bits. So, +we're talking about constraint length + + align:start position:0% +we're talking about constraint length + + + align:start position:0% +we're talking about constraint length +three here. And what about p1n? It's xn + + align:start position:0% +three here. And what about p1n? It's xn + + + align:start position:0% +three here. And what about p1n? It's xn +plus xn minus 2 with nothing of xn minus + + align:start position:0% +plus xn minus 2 with nothing of xn minus + + + align:start position:0% +plus xn minus 2 with nothing of xn minus +one. + + align:start position:0% +one. + + + align:start position:0% +one. +And so imagine this being the picture + + align:start position:0% +And so imagine this being the picture + + + align:start position:0% +And so imagine this being the picture +for every n. So you start off at time + + align:start position:0% +for every n. So you start off at time + + + align:start position:0% +for every n. So you start off at time +zero and keep going. Right? + + align:start position:0% +zero and keep going. Right? + + + align:start position:0% +zero and keep going. Right? +Uh we refer to the state of the shift + + align:start position:0% +Uh we refer to the state of the shift + + + align:start position:0% +Uh we refer to the state of the shift +registers as the pair of numbers that we + + align:start position:0% +registers as the pair of numbers that we + + + align:start position:0% +registers as the pair of numbers that we +find in here. So if we're talking about + + align:start position:0% +find in here. So if we're talking about + + + align:start position:0% +find in here. So if we're talking about +X's that can be zeros or ones, uh the + + align:start position:0% +X's that can be zeros or ones, uh the + + + align:start position:0% +X's that can be zeros or ones, uh the +shift register combination here can be + + align:start position:0% +shift register combination here can be + + + align:start position:0% +shift register combination here can be +in one of four states, right? 0 0 1 1 0 + + align:start position:0% +in one of four states, right? 0 0 1 1 0 + + + align:start position:0% +in one of four states, right? 0 0 1 1 0 +or one one. So four states. So here's a + + align:start position:0% +or one one. So four states. So here's a + + + align:start position:0% +or one one. So four states. So here's a +four state U shift register into which + + align:start position:0% +four state U shift register into which + + + align:start position:0% +four state U shift register into which +we're feeding in the stream. And what + + align:start position:0% +we're feeding in the stream. And what + + + align:start position:0% +we're feeding in the stream. And what +gets put out on the channel are these + + align:start position:0% +gets put out on the channel are these + + + align:start position:0% +gets put out on the channel are these +parody bits interled. + + align:start position:0% +parody bits interled. + + + align:start position:0% +parody bits interled. +That clear enough? + + align:start position:0% +That clear enough? + + + align:start position:0% +That clear enough? +Okay. + + align:start position:0% + + + + align:start position:0% + +Nothing I haven't said here, right? + + align:start position:0% + + + + align:start position:0% + +So, let's actually work through an + + align:start position:0% +So, let's actually work through an + + + align:start position:0% +So, let's actually work through an +example + + align:start position:0% +example + + + align:start position:0% +example +step by step. This this is clear enough, + + align:start position:0% +step by step. This this is clear enough, + + + align:start position:0% +step by step. This this is clear enough, +but let's just see it concretely. Um, + + align:start position:0% +but let's just see it concretely. Um, + + + align:start position:0% +but let's just see it concretely. Um, +let's assume that I'm starting out with + + align:start position:0% +let's assume that I'm starting out with + + + align:start position:0% +let's assume that I'm starting out with +the shift registers in the zero state. + + align:start position:0% +the shift registers in the zero state. + + + align:start position:0% +the shift registers in the zero state. +And now I've got this message sequence + + align:start position:0% +And now I've got this message sequence + + + align:start position:0% +And now I've got this message sequence +coming in that I want to send out. Okay, + + align:start position:0% +coming in that I want to send out. Okay, + + + align:start position:0% +coming in that I want to send out. Okay, +so the sequence is 1 0 1 1. + + align:start position:0% +so the sequence is 1 0 1 1. + + + align:start position:0% +so the sequence is 1 0 1 1. +So the first bit that appears here is + + align:start position:0% +So the first bit that appears here is + + + align:start position:0% +So the first bit that appears here is +the one and I've got to generate P 0 and + + align:start position:0% +the one and I've got to generate P 0 and + + + align:start position:0% +the one and I've got to generate P 0 and +P1. Well, P 0 is the exclusive R of + + align:start position:0% +P1. Well, P 0 is the exclusive R of + + + align:start position:0% +P1. Well, P 0 is the exclusive R of +these three things. So it's one. Uh, P1 + + align:start position:0% +these three things. So it's one. Uh, P1 + + + align:start position:0% +these three things. So it's one. Uh, P1 +is the exclusive R of the first and the + + align:start position:0% +is the exclusive R of the first and the + + + align:start position:0% +is the exclusive R of the first and the +last. So it's again one. So that defines + + align:start position:0% +last. So it's again one. So that defines + + + align:start position:0% +last. So it's again one. So that defines +P 0 and P1 at time N. + + align:start position:0% +P 0 and P1 at time N. + + + align:start position:0% +P 0 and P1 at time N. +And the same way at the next time + + align:start position:0% +And the same way at the next time + + + align:start position:0% +And the same way at the next time +instant the next input the next message + + align:start position:0% +instant the next input the next message + + + align:start position:0% +instant the next input the next message +input bit comes in. Uh so we had one + + align:start position:0% +input bit comes in. Uh so we had one + + + align:start position:0% +input bit comes in. Uh so we had one +zero one one we took care of the one + + align:start position:0% +zero one one we took care of the one + + + align:start position:0% +zero one one we took care of the one +here. Now comes a zero. Uh we do the + + align:start position:0% +here. Now comes a zero. Uh we do the + + + align:start position:0% +here. Now comes a zero. Uh we do the +same thing. So the exclusive R of all + + align:start position:0% +same thing. So the exclusive R of all + + + align:start position:0% +same thing. So the exclusive R of all +three of them appears here. That's the + + align:start position:0% +three of them appears here. That's the + + + align:start position:0% +three of them appears here. That's the +one. The exclusive R of the first and + + align:start position:0% +one. The exclusive R of the first and + + + align:start position:0% +one. The exclusive R of the first and +the last appears there and that's the + + align:start position:0% +the last appears there and that's the + + + align:start position:0% +the last appears there and that's the +zero. So you can see how things are + + align:start position:0% +zero. So you can see how things are + + + align:start position:0% +zero. So you can see how things are +getting folded together. + + align:start position:0% +getting folded together. + + + align:start position:0% +getting folded together. +uh because the input that was here + + align:start position:0% +uh because the input that was here + + + align:start position:0% +uh because the input that was here +before is now sitting in here and plays + + align:start position:0% +before is now sitting in here and plays + + + align:start position:0% +before is now sitting in here and plays +a role in generation of the uh par bit + + align:start position:0% +a role in generation of the uh par bit + + + align:start position:0% +a role in generation of the uh par bit +for the next step. Okay, in fact the + + align:start position:0% +for the next step. Okay, in fact the + + + align:start position:0% +for the next step. Okay, in fact the +word convolve means to fold together and + + align:start position:0% +word convolve means to fold together and + + + align:start position:0% +word convolve means to fold together and +this is what it's actually trying to + + align:start position:0% +this is what it's actually trying to + + + align:start position:0% +this is what it's actually trying to +capture. You're folding together these + + align:start position:0% +capture. You're folding together these + + + align:start position:0% +capture. You're folding together these +uh these two sets of weights the weights + + align:start position:0% +uh these two sets of weights the weights + + + align:start position:0% +uh these two sets of weights the weights +on the taps here and the input sequence + + align:start position:0% +on the taps here and the input sequence + + + align:start position:0% +on the taps here and the input sequence +weight. + + align:start position:0% +weight. + + + align:start position:0% +weight. +And then the next uh two cases + + align:start position:0% +And then the next uh two cases + + + align:start position:0% +And then the next uh two cases +similarly. + + align:start position:0% +similarly. + + + align:start position:0% +similarly. +Okay. And that's what gets sent out at + + align:start position:0% +Okay. And that's what gets sent out at + + + align:start position:0% +Okay. And that's what gets sent out at +the bottom. + + align:start position:0% +the bottom. + + + align:start position:0% +the bottom. +So this is the transmitted sequence. So + + align:start position:0% +So this is the transmitted sequence. So + + + align:start position:0% +So this is the transmitted sequence. So +it's the one one + + align:start position:0% +it's the one one + + + align:start position:0% +it's the one one +0 0 0 1. Right? That's all there is to + + align:start position:0% +0 0 0 1. Right? That's all there is to + + + align:start position:0% +0 0 0 1. Right? That's all there is to +it. The implementation of the shift + + align:start position:0% +it. The implementation of the shift + + + align:start position:0% +it. The implementation of the shift +register is very easy. Um and so this is + + align:start position:0% +register is very easy. Um and so this is + + + align:start position:0% +register is very easy. Um and so this is +actually + + align:start position:0% +actually + + + align:start position:0% +actually +a a very straightforward thing to + + align:start position:0% +a a very straightforward thing to + + + align:start position:0% +a a very straightforward thing to +implement. + + align:start position:0% +implement. + + + align:start position:0% +implement. +Now there's another viewpoint + + align:start position:0% +Now there's another viewpoint + + + align:start position:0% +Now there's another viewpoint +that's also very useful here. + + align:start position:0% +that's also very useful here. + + + align:start position:0% +that's also very useful here. +Another way to look at what's going on + + align:start position:0% +Another way to look at what's going on + + + align:start position:0% +Another way to look at what's going on +uh which is thinking in terms of the + + align:start position:0% +uh which is thinking in terms of the + + + align:start position:0% +uh which is thinking in terms of the +state of the register and how you uh + + align:start position:0% +state of the register and how you uh + + + align:start position:0% +state of the register and how you uh +move between the states. I guess um how + + align:start position:0% +move between the states. I guess um how + + + align:start position:0% +move between the states. I guess um how +many here are doing 004? Are those the + + align:start position:0% +many here are doing 004? Are those the + + + align:start position:0% +many here are doing 004? Are those the +ones with smiles on their faces? Yeah. + + align:start position:0% +ones with smiles on their faces? Yeah. + + + align:start position:0% +ones with smiles on their faces? Yeah. +Okay. Um, you see a lot of this there I + + align:start position:0% +Okay. Um, you see a lot of this there I + + + align:start position:0% +Okay. Um, you see a lot of this there I +imagine. + + align:start position:0% +imagine. + + + align:start position:0% +imagine. +Okay. So, how do I read a diagram like + + align:start position:0% +Okay. So, how do I read a diagram like + + + align:start position:0% +Okay. So, how do I read a diagram like +this? + + align:start position:0% +this? + + + align:start position:0% +this? +I've got a circle for each state that + + align:start position:0% +I've got a circle for each state that + + + align:start position:0% +I've got a circle for each state that +the shift register can be in. So, the + + align:start position:0% +the shift register can be in. So, the + + + align:start position:0% +the shift register can be in. So, the +shift register can be in 0 0 1 0 sorry 0 + + align:start position:0% +shift register can be in 0 0 1 0 sorry 0 + + + align:start position:0% +shift register can be in 0 0 1 0 sorry 0 +0 1 1 0 1 1, right? Um, each of these + + align:start position:0% +0 1 1 0 1 1, right? Um, each of these + + + align:start position:0% +0 1 1 0 1 1, right? Um, each of these +arcs represents a transition from one + + align:start position:0% +arcs represents a transition from one + + + align:start position:0% +arcs represents a transition from one +state to another. So, let me ask you + + align:start position:0% +state to another. So, let me ask you + + + align:start position:0% +state to another. So, let me ask you +this. What does it take + + align:start position:0% +this. What does it take + + + align:start position:0% +this. What does it take +if I'm in the 000 state + + align:start position:0% +if I'm in the 000 state + + + align:start position:0% +if I'm in the 000 state +with my shift register? So, what you've + + align:start position:0% +with my shift register? So, what you've + + + align:start position:0% +with my shift register? So, what you've +got to picture is your shift register + + align:start position:0% +got to picture is your shift register + + + align:start position:0% +got to picture is your shift register +sitting there with 0 0. What does it + + align:start position:0% +sitting there with 0 0. What does it + + + align:start position:0% +sitting there with 0 0. What does it +take for me to get to the + + align:start position:0% +take for me to get to the + + + align:start position:0% +take for me to get to the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +one zero state? + + align:start position:0% + + + + align:start position:0% + +What must my input have been to get to + + align:start position:0% +What must my input have been to get to + + + align:start position:0% +What must my input have been to get to +the one zero state? + + align:start position:0% + + + + align:start position:0% + +Imagine how these shift registers + + align:start position:0% +Imagine how these shift registers + + + align:start position:0% +Imagine how these shift registers +operate. Right? If I'm going to get from + + align:start position:0% +operate. Right? If I'm going to get from + + + align:start position:0% +operate. Right? If I'm going to get from +0 0 to one 0, I must have fed in a one + + align:start position:0% +0 0 to one 0, I must have fed in a one + + + align:start position:0% +0 0 to one 0, I must have fed in a one +at the previous time instant. Right? So + + align:start position:0% +at the previous time instant. Right? So + + + align:start position:0% +at the previous time instant. Right? So +it takes an input of one to go from the + + align:start position:0% +it takes an input of one to go from the + + + align:start position:0% +it takes an input of one to go from the +0 0 to the one zero. So to go from 0 0 + + align:start position:0% +0 0 to the one zero. So to go from 0 0 + + + align:start position:0% +0 0 to the one zero. So to go from 0 0 +to one zero, you use an input of one. + + align:start position:0% +to one zero, you use an input of one. + + + align:start position:0% +to one zero, you use an input of one. +That's the number that we write before + + align:start position:0% +That's the number that we write before + + + align:start position:0% +That's the number that we write before +the slash. That's our uh labeling + + align:start position:0% +the slash. That's our uh labeling + + + align:start position:0% +the slash. That's our uh labeling +convention for the arcs. We put the + + align:start position:0% +convention for the arcs. We put the + + + align:start position:0% +convention for the arcs. We put the +input that it takes to make that + + align:start position:0% +input that it takes to make that + + + align:start position:0% +input that it takes to make that +transition and then after the slash we + + align:start position:0% +transition and then after the slash we + + + align:start position:0% +transition and then after the slash we +put the parity bits that are emitted. So + + align:start position:0% +put the parity bits that are emitted. So + + + align:start position:0% +put the parity bits that are emitted. So +what we've got for the one one is the + + align:start position:0% +what we've got for the one one is the + + + align:start position:0% +what we've got for the one one is the +parity bits that are emitted. When + + align:start position:0% +parity bits that are emitted. When + + + align:start position:0% +parity bits that are emitted. When +you've got input one sitting here 0 0 + + align:start position:0% +you've got input one sitting here 0 0 + + + align:start position:0% +you've got input one sitting here 0 0 +here and you're using the parity + + align:start position:0% +here and you're using the parity + + + align:start position:0% +here and you're using the parity +computation that I uh had before. Let's + + align:start position:0% +computation that I uh had before. Let's + + + align:start position:0% +computation that I uh had before. Let's +see here. + + align:start position:0% +see here. + + + align:start position:0% +see here. +So P 0 is going to be X N + XN -1 plus X + + align:start position:0% +So P 0 is going to be X N + XN -1 plus X + + + align:start position:0% +So P 0 is going to be X N + XN -1 plus X +N - 2. So that gives you a one. And what + + align:start position:0% +N - 2. So that gives you a one. And what + + + align:start position:0% +N - 2. So that gives you a one. And what +about P1? P1 is XN plus XN minus 2. So + + align:start position:0% +about P1? P1 is XN plus XN minus 2. So + + + align:start position:0% +about P1? P1 is XN plus XN minus 2. So +that gives you another one. Okay. So you + + align:start position:0% +that gives you another one. Okay. So you + + + align:start position:0% +that gives you another one. Okay. So you +if you're in state zero, the 0 0 state, + + align:start position:0% +if you're in state zero, the 0 0 state, + + + align:start position:0% +if you're in state zero, the 0 0 state, +and you get an input of one, you're + + align:start position:0% +and you get an input of one, you're + + + align:start position:0% +and you get an input of one, you're +going to transition to one zero, and + + align:start position:0% +going to transition to one zero, and + + + align:start position:0% +going to transition to one zero, and +you're going to emit one one. Okay? So + + align:start position:0% +you're going to emit one one. Okay? So + + + align:start position:0% +you're going to emit one one. Okay? So +the state diagram captures all that. And + + align:start position:0% +the state diagram captures all that. And + + + align:start position:0% +the state diagram captures all that. And +similarly all the way around. So I + + align:start position:0% +similarly all the way around. So I + + + align:start position:0% +similarly all the way around. So I +haven't checked each of these, but I + + align:start position:0% +haven't checked each of these, but I + + + align:start position:0% +haven't checked each of these, but I +hope uh there no mistakes in it. Uh but + + align:start position:0% +hope uh there no mistakes in it. Uh but + + + align:start position:0% +hope uh there no mistakes in it. Uh but +if you're in one zero, well, by the way, + + align:start position:0% +if you're in one zero, well, by the way, + + + align:start position:0% +if you're in one zero, well, by the way, +if you're in 0 0, there's no way to get + + align:start position:0% +if you're in 0 0, there's no way to get + + + align:start position:0% +if you're in 0 0, there's no way to get +to 01, right? So you don't see any arc + + align:start position:0% +to 01, right? So you don't see any arc + + + align:start position:0% +to 01, right? So you don't see any arc +from 0 0 to 01. Um if you're in one + + align:start position:0% +from 0 0 to 01. Um if you're in one + + + align:start position:0% +from 0 0 to 01. Um if you're in one +zero, you can get to one one or you can + + align:start position:0% +zero, you can get to one one or you can + + + align:start position:0% +zero, you can get to one one or you can +get to 01 depending on what you feed in. + + align:start position:0% +get to 01 depending on what you feed in. + + + align:start position:0% +get to 01 depending on what you feed in. +Okay. Uh so it's very straightforward + + align:start position:0% +Okay. Uh so it's very straightforward + + + align:start position:0% +Okay. Uh so it's very straightforward +then to actually build up this diagram. + + align:start position:0% +then to actually build up this diagram. + + + align:start position:0% +then to actually build up this diagram. +Why don't we do + + align:start position:0% + + + + align:start position:0% + +a little bit more on here. + + align:start position:0% + + + + align:start position:0% + +Okay. So, um if I'm actually + + align:start position:0% +Okay. So, um if I'm actually + + + align:start position:0% +Okay. So, um if I'm actually +abstracting from the shift register + + align:start position:0% +abstracting from the shift register + + + align:start position:0% +abstracting from the shift register +picture to something that's more like + + align:start position:0% +picture to something that's more like + + + align:start position:0% +picture to something that's more like +the state picture, I'm going to say here + + align:start position:0% +the state picture, I'm going to say here + + + align:start position:0% +the state picture, I'm going to say here +are my four states. I've just drawn it a + + align:start position:0% +are my four states. I've just drawn it a + + + align:start position:0% +are my four states. I've just drawn it a +different a little differently than I + + align:start position:0% +different a little differently than I + + + align:start position:0% +different a little differently than I +have in the upper picture. Instead of + + align:start position:0% +have in the upper picture. Instead of + + + align:start position:0% +have in the upper picture. Instead of +circles with these states in them, I + + align:start position:0% +circles with these states in them, I + + + align:start position:0% +circles with these states in them, I +prefer to think of them this way. So, + + align:start position:0% +prefer to think of them this way. So, + + + align:start position:0% +prefer to think of them this way. So, +what we said is if you + + align:start position:0% +what we said is if you + + + align:start position:0% +what we said is if you +get an input of one, you'll emit one one + + align:start position:0% +get an input of one, you'll emit one one + + + align:start position:0% +get an input of one, you'll emit one one +and you'll get to that state. Uh what + + align:start position:0% +and you'll get to that state. Uh what + + + align:start position:0% +and you'll get to that state. Uh what +does it take to get to the state? + + align:start position:0% + + + + align:start position:0% + +Somebody + + align:start position:0% + + + + align:start position:0% + +can I have a hand in a loud voice? + + align:start position:0% +can I have a hand in a loud voice? + + + align:start position:0% +can I have a hand in a loud voice? +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Okay. And then I guess you've got to uh + + align:start position:0% +Okay. And then I guess you've got to uh + + + align:start position:0% +Okay. And then I guess you've got to uh +go back to this to think about what's + + align:start position:0% +go back to this to think about what's + + + align:start position:0% +go back to this to think about what's +happening. So I'll allow you to think of + + align:start position:0% +happening. So I'll allow you to think of + + + align:start position:0% +happening. So I'll allow you to think of +a zero sitting at the input here. So + + align:start position:0% +a zero sitting at the input here. So + + + align:start position:0% +a zero sitting at the input here. So +what would the uh parity bits be? + + align:start position:0% + + + + align:start position:0% + +So the first par bit will be the + + align:start position:0% +So the first par bit will be the + + + align:start position:0% +So the first par bit will be the +exclusive R of the zero, one, and zero. + + align:start position:0% +exclusive R of the zero, one, and zero. + + + align:start position:0% +exclusive R of the zero, one, and zero. +So that's going to give you a one, + + align:start position:0% +So that's going to give you a one, + + + align:start position:0% +So that's going to give you a one, +right? And then the next parity bit is + + align:start position:0% +right? And then the next parity bit is + + + align:start position:0% +right? And then the next parity bit is +going to be exclusive R of what's here + + align:start position:0% +going to be exclusive R of what's here + + + align:start position:0% +going to be exclusive R of what's here +and there. So that's going to be a zero. + + align:start position:0% +and there. So that's going to be a zero. + + + align:start position:0% +and there. So that's going to be a zero. +I hope that matches with what I have + + align:start position:0% +I hope that matches with what I have + + + align:start position:0% +I hope that matches with what I have +upstairs. We're talking about going from + + align:start position:0% +upstairs. We're talking about going from + + + align:start position:0% +upstairs. We're talking about going from +one zero to 01. It takes a zero input to + + align:start position:0% +one zero to 01. It takes a zero input to + + + align:start position:0% +one zero to 01. It takes a zero input to +do that. and what you emit is one zero. + + align:start position:0% +do that. and what you emit is one zero. + + + align:start position:0% +do that. and what you emit is one zero. +Right? + + align:start position:0% + + + + align:start position:0% + +So you can fill in all of these. This is + + align:start position:0% +So you can fill in all of these. This is + + + align:start position:0% +So you can fill in all of these. This is +a state transition diagram. + + align:start position:0% +a state transition diagram. + + + align:start position:0% +a state transition diagram. +Okay. Um + + align:start position:0% + + + + align:start position:0% + +let's see. And we say that if you've got + + align:start position:0% +let's see. And we say that if you've got + + + align:start position:0% +let's see. And we say that if you've got +a constraint length of three then of k + + align:start position:0% +a constraint length of three then of k + + + align:start position:0% +a constraint length of three then of k +equals 3 for instance or let's say if + + align:start position:0% +equals 3 for instance or let's say if + + + align:start position:0% +equals 3 for instance or let's say if +you've got a constraint length of k uh + + align:start position:0% +you've got a constraint length of k uh + + + align:start position:0% +you've got a constraint length of k uh +you've got 2 to the k minus one states. + + align:start position:0% +you've got 2 to the k minus one states. + + + align:start position:0% +you've got 2 to the k minus one states. +Well, that's because + + align:start position:0% +Well, that's because + + + align:start position:0% +Well, that's because +uh in that constraint length, one of the + + align:start position:0% +uh in that constraint length, one of the + + + align:start position:0% +uh in that constraint length, one of the +uh bits involved is the input bit. + + align:start position:0% +uh bits involved is the input bit. + + + align:start position:0% +uh bits involved is the input bit. +That's not sitting in the shift + + align:start position:0% +That's not sitting in the shift + + + align:start position:0% +That's not sitting in the shift +registers. So, you've got k minus one + + align:start position:0% +registers. So, you've got k minus one + + + align:start position:0% +registers. So, you've got k minus one +bits left over. So, your shift register + + align:start position:0% +bits left over. So, your shift register + + + align:start position:0% +bits left over. So, your shift register +is k minus one stages long. And so, + + align:start position:0% +is k minus one stages long. And so, + + + align:start position:0% +is k minus one stages long. And so, +you've got 2 to the k minus one states. + + align:start position:0% +you've got 2 to the k minus one states. + + + align:start position:0% +you've got 2 to the k minus one states. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +all right. So, you could imagine + + align:start position:0% +all right. So, you could imagine + + + align:start position:0% +all right. So, you could imagine +generalizing this to more complicated + + align:start position:0% +generalizing this to more complicated + + + align:start position:0% +generalizing this to more complicated +sorts of situations. + + align:start position:0% + + + + align:start position:0% + +Let's see. Just going back to the + + align:start position:0% +Let's see. Just going back to the + + + align:start position:0% +Let's see. Just going back to the +Cassini example. + + align:start position:0% +Cassini example. + + + align:start position:0% +Cassini example. +If you let me jump back a bit, + + align:start position:0% +If you let me jump back a bit, + + + align:start position:0% +If you let me jump back a bit, +there was a K there. What was it? + + align:start position:0% + + + + align:start position:0% + +K of 15. Okay. So for Cassini, you're + + align:start position:0% +K of 15. Okay. So for Cassini, you're + + + align:start position:0% +K of 15. Okay. So for Cassini, you're +using one input bit and 14 more bits in + + align:start position:0% +using one input bit and 14 more bits in + + + align:start position:0% +using one input bit and 14 more bits in +your register. Okay. Okay, so you've got + + align:start position:0% +your register. Okay. Okay, so you've got + + + align:start position:0% +your register. Okay. Okay, so you've got +2 to the 14 possible states there. + + align:start position:0% +2 to the 14 possible states there. + + + align:start position:0% +2 to the 14 possible states there. +So in these codes, you're actually using + + align:start position:0% +So in these codes, you're actually using + + + align:start position:0% +So in these codes, you're actually using +very large constraints. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +All right. I want to go from the state + + align:start position:0% +All right. I want to go from the state + + + align:start position:0% +All right. I want to go from the state +machine view uh to another view now + + align:start position:0% +machine view uh to another view now + + + align:start position:0% +machine view uh to another view now +which is what's called so this is the + + align:start position:0% +which is what's called so this is the + + + align:start position:0% +which is what's called so this is the +state machine view + + align:start position:0% + + + + align:start position:0% + +uh to something called the trellis view. + + align:start position:0% + + + + align:start position:0% + +This is something by the way that was uh + + align:start position:0% +This is something by the way that was uh + + + align:start position:0% +This is something by the way that was uh +a way of looking at things that was um + + align:start position:0% +a way of looking at things that was um + + + align:start position:0% +a way of looking at things that was um +developed by someone else who's on our + + align:start position:0% +developed by someone else who's on our + + + align:start position:0% +developed by someone else who's on our +faculty David Forny. Um + + align:start position:0% +faculty David Forny. Um + + + align:start position:0% +faculty David Forny. Um +in fact if you visit his home you'll see + + align:start position:0% +in fact if you visit his home you'll see + + + align:start position:0% +in fact if you visit his home you'll see +his garden has a nice trellis around it + + align:start position:0% +his garden has a nice trellis around it + + + align:start position:0% +his garden has a nice trellis around it +and you'll see why when I when we draw + + align:start position:0% +and you'll see why when I when we draw + + + align:start position:0% +and you'll see why when I when we draw +this + + align:start position:0% + + + + align:start position:0% + +okay so what's the trellis view? So the + + align:start position:0% +okay so what's the trellis view? So the + + + align:start position:0% +okay so what's the trellis view? So the +trellis view says take the state machine + + align:start position:0% +trellis view says take the state machine + + + align:start position:0% +trellis view says take the state machine +but unfold it in time so that all your + + align:start position:0% +but unfold it in time so that all your + + + align:start position:0% +but unfold it in time so that all your +transitions over time are not happening + + align:start position:0% +transitions over time are not happening + + + align:start position:0% +transitions over time are not happening +here. Every time step you draw the + + align:start position:0% +here. Every time step you draw the + + + align:start position:0% +here. Every time step you draw the +picture again and look to see where you + + align:start position:0% +picture again and look to see where you + + + align:start position:0% +picture again and look to see where you +get to. So let's do this. This is the + + align:start position:0% +get to. So let's do this. This is the + + + align:start position:0% +get to. So let's do this. This is the +one I want to be most careful with + + align:start position:0% +one I want to be most careful with + + + align:start position:0% +one I want to be most careful with +and where I'll introduce a few + + align:start position:0% +and where I'll introduce a few + + + align:start position:0% +and where I'll introduce a few +notational conventions + + align:start position:0% + + + + align:start position:0% + +so that our later life is simplified. + + align:start position:0% + + + + align:start position:0% + +Okay, so we've got state 0 0, state 01, + + align:start position:0% +Okay, so we've got state 0 0, state 01, + + + align:start position:0% +Okay, so we've got state 0 0, state 01, +state 1 0, + + align:start position:0% +state 1 0, + + + align:start position:0% +state 1 0, +and state 1 one. + + align:start position:0% + + + + align:start position:0% + +Okay, except that this is going to be + + align:start position:0% +Okay, except that this is going to be + + + align:start position:0% +Okay, except that this is going to be +the picture that I have at time, let's + + align:start position:0% +the picture that I have at time, let's + + + align:start position:0% +the picture that I have at time, let's +say, at time n equals z. + + align:start position:0% + + + + align:start position:0% + +At time n equals 1. While I've got this + + align:start position:0% +At time n equals 1. While I've got this + + + align:start position:0% +At time n equals 1. While I've got this +the same shift registers, I'm going to + + align:start position:0% +the same shift registers, I'm going to + + + align:start position:0% +the same shift registers, I'm going to +draw this picture again. + + align:start position:0% + + + + align:start position:0% + +The easiest way to learn this is to just + + align:start position:0% +The easiest way to learn this is to just + + + align:start position:0% +The easiest way to learn this is to just +follow through one example. So, please + + align:start position:0% +follow through one example. So, please + + + align:start position:0% +follow through one example. So, please +keep your attention here and you'll have + + align:start position:0% +keep your attention here and you'll have + + + align:start position:0% +keep your attention here and you'll have +it sorted out and then you won't have to + + align:start position:0% +it sorted out and then you won't have to + + + align:start position:0% +it sorted out and then you won't have to +worry about it again. It's the same + + align:start position:0% +worry about it again. It's the same + + + align:start position:0% +worry about it again. It's the same +thing as with LZW. + + align:start position:0% +thing as with LZW. + + + align:start position:0% +thing as with LZW. +All right. So it looks kind of detailed, + + align:start position:0% +All right. So it looks kind of detailed, + + + align:start position:0% +All right. So it looks kind of detailed, +maybe tedious, but it's actually very + + align:start position:0% +maybe tedious, but it's actually very + + + align:start position:0% +maybe tedious, but it's actually very +simple. Just hang in there and follow + + align:start position:0% +simple. Just hang in there and follow + + + align:start position:0% +simple. Just hang in there and follow +through one example. + + align:start position:0% +through one example. + + + align:start position:0% +through one example. +Okay. So what does this say? I'm in at + + align:start position:0% +Okay. So what does this say? I'm in at + + + align:start position:0% +Okay. So what does this say? I'm in at +time n equals 0. Uh I'm in 0 0. Suppose + + align:start position:0% +time n equals 0. Uh I'm in 0 0. Suppose + + + align:start position:0% +time n equals 0. Uh I'm in 0 0. Suppose +I get the input zero. Suppose the input + + align:start position:0% +I get the input zero. Suppose the input + + + align:start position:0% +I get the input zero. Suppose the input +is zero. What state do I transition to + + align:start position:0% +is zero. What state do I transition to + + + align:start position:0% +is zero. What state do I transition to +here? Right? + + align:start position:0% +here? Right? + + + align:start position:0% +here? Right? +So if I have an input zero, I'm going to + + align:start position:0% +So if I have an input zero, I'm going to + + + align:start position:0% +So if I have an input zero, I'm going to +transition here. So this is with an + + align:start position:0% +transition here. So this is with an + + + align:start position:0% +transition here. So this is with an +input of zero. And what are my parity + + align:start position:0% +input of zero. And what are my parity + + + align:start position:0% +input of zero. And what are my parity +bits going to be? + + align:start position:0% + + + + align:start position:0% + +Both zeros, right? + + align:start position:0% + + + + align:start position:0% + +What about if I get an input of one? + + align:start position:0% +What about if I get an input of one? + + + align:start position:0% +What about if I get an input of one? +Where do I transition to? Well, we've + + align:start position:0% +Where do I transition to? Well, we've + + + align:start position:0% +Where do I transition to? Well, we've +already seen that here. If I get an + + align:start position:0% +already seen that here. If I get an + + + align:start position:0% +already seen that here. If I get an +input of one, I'm going to transition to + + align:start position:0% +input of one, I'm going to transition to + + + align:start position:0% +input of one, I'm going to transition to +here. + + align:start position:0% + + + + align:start position:0% + +And what am I going to emit? + + align:start position:0% +And what am I going to emit? + + + align:start position:0% +And what am I going to emit? +Well, we've already calculated that + + align:start position:0% +Well, we've already calculated that + + + align:start position:0% +Well, we've already calculated that +we're going to emit a one one, + + align:start position:0% + + + + align:start position:0% + +right? + + align:start position:0% + + + + align:start position:0% + +Let's do it for one more case. We're in + + align:start position:0% +Let's do it for one more case. We're in + + + align:start position:0% +Let's do it for one more case. We're in +01. + + align:start position:0% +01. + + + align:start position:0% +01. +What states can I transition to? + + align:start position:0% +What states can I transition to? + + + align:start position:0% +What states can I transition to? +I could go to 0 0. + + align:start position:0% + + + + align:start position:0% + +And I would do that if my input was + + align:start position:0% +And I would do that if my input was + + + align:start position:0% +And I would do that if my input was +zero, right? + + align:start position:0% +zero, right? + + + align:start position:0% +zero, right? +And what would my par bits be? + + align:start position:0% +And what would my par bits be? + + + align:start position:0% +And what would my par bits be? +Well, that's another case for us to look + + align:start position:0% +Well, that's another case for us to look + + + align:start position:0% +Well, that's another case for us to look +at. Um, if our input is zero and we're + + align:start position:0% +at. Um, if our input is zero and we're + + + align:start position:0% +at. Um, if our input is zero and we're +in state 01, what would the parity bits + + align:start position:0% +in state 01, what would the parity bits + + + align:start position:0% +in state 01, what would the parity bits +be + + align:start position:0% + + + + align:start position:0% + +for this choice of parity bits? It + + align:start position:0% +for this choice of parity bits? It + + + align:start position:0% +for this choice of parity bits? It +depends on what specific choice you + + align:start position:0% +depends on what specific choice you + + + align:start position:0% +depends on what specific choice you +made, of course. + + align:start position:0% +made, of course. + + + align:start position:0% +made, of course. +One one + + align:start position:0% + + + + align:start position:0% + +you agree. + + align:start position:0% + + + + align:start position:0% + +And if I get an input of one instead, + + align:start position:0% +And if I get an input of one instead, + + + align:start position:0% +And if I get an input of one instead, +where do I go? If I get an input of one, + + align:start position:0% +where do I go? If I get an input of one, + + + align:start position:0% +where do I go? If I get an input of one, +I'm going to go to one zero. Um, + + align:start position:0% +I'm going to go to one zero. Um, + + + align:start position:0% +I'm going to go to one zero. Um, +which is here. + + align:start position:0% + + + + align:start position:0% + +Okay. So, if I had an input of one, I + + align:start position:0% +Okay. So, if I had an input of one, I + + + align:start position:0% +Okay. So, if I had an input of one, I +would go to one zero. My parity bits + + align:start position:0% +would go to one zero. My parity bits + + + align:start position:0% +would go to one zero. My parity bits +would be what would they be? + + align:start position:0% + + + + align:start position:0% + +Can I have a hand on the voice? Yeah. 0 + + align:start position:0% +Can I have a hand on the voice? Yeah. 0 + + + align:start position:0% +Can I have a hand on the voice? Yeah. 0 +0. Right. + + align:start position:0% + + + + align:start position:0% + +Okay, so it's that simple. That's all + + align:start position:0% +Okay, so it's that simple. That's all + + + align:start position:0% +Okay, so it's that simple. That's all +you have to do. Fill out this picture + + align:start position:0% +you have to do. Fill out this picture + + + align:start position:0% +you have to do. Fill out this picture +and you're seeing what this picture + + align:start position:0% +and you're seeing what this picture + + + align:start position:0% +and you're seeing what this picture +translates to at the next time instant. + + align:start position:0% +translates to at the next time instant. + + + align:start position:0% +translates to at the next time instant. +We're not using anything more than is in + + align:start position:0% +We're not using anything more than is in + + + align:start position:0% +We're not using anything more than is in +the state transition uh sorry in the in + + align:start position:0% +the state transition uh sorry in the in + + + align:start position:0% +the state transition uh sorry in the in +the state machine diagram. Uh but we're + + align:start position:0% +the state machine diagram. Uh but we're + + + align:start position:0% +the state machine diagram. Uh but we're +unfolding things in time which is + + align:start position:0% +unfolding things in time which is + + + align:start position:0% +unfolding things in time which is +actually very helpful. + + align:start position:0% + + + + align:start position:0% + +Now there's a simplification we'll make + + align:start position:0% +Now there's a simplification we'll make + + + align:start position:0% +Now there's a simplification we'll make +in drawing this because I've arranged + + align:start position:0% +in drawing this because I've arranged + + + align:start position:0% +in drawing this because I've arranged +the uh states in natural binary counting + + align:start position:0% +the uh states in natural binary counting + + + align:start position:0% +the uh states in natural binary counting +order 0 0 1 1 0 and 1 1. It's always the + + align:start position:0% +order 0 0 1 1 0 and 1 1. It's always the + + + align:start position:0% +order 0 0 1 1 0 and 1 1. It's always the +case that the upper arrow that emanates + + align:start position:0% +case that the upper arrow that emanates + + + align:start position:0% +case that the upper arrow that emanates +from a state corresponds to an input of + + align:start position:0% +from a state corresponds to an input of + + + align:start position:0% +from a state corresponds to an input of +zero and the lower arrow corresponds to + + align:start position:0% +zero and the lower arrow corresponds to + + + align:start position:0% +zero and the lower arrow corresponds to +an input of one. Okay? So I don't really + + align:start position:0% +an input of one. Okay? So I don't really + + + align:start position:0% +an input of one. Okay? So I don't really +need that first thing before the dash. + + align:start position:0% +need that first thing before the dash. + + + align:start position:0% +need that first thing before the dash. +I'm just going to dispense with it. So + + align:start position:0% +I'm just going to dispense with it. So + + + align:start position:0% +I'm just going to dispense with it. So +if you're going up of the two choices + + align:start position:0% +if you're going up of the two choices + + + align:start position:0% +if you're going up of the two choices +that you have when you come out of a + + align:start position:0% +that you have when you come out of a + + + align:start position:0% +that you have when you come out of a +box, if you're going up, it's zero. The + + align:start position:0% +box, if you're going up, it's zero. The + + + align:start position:0% +box, if you're going up, it's zero. The +input was zero. And if you're going + + align:start position:0% +input was zero. And if you're going + + + align:start position:0% +input was zero. And if you're going +down, the input was one. So I'm just + + align:start position:0% +down, the input was one. So I'm just + + + align:start position:0% +down, the input was one. So I'm just +going to label that as 0 0. + + align:start position:0% +going to label that as 0 0. + + + align:start position:0% +going to label that as 0 0. +I'm going to label this as one, one. + + align:start position:0% + + + + align:start position:0% + +And um I guess I've forgotten already + + align:start position:0% +And um I guess I've forgotten already + + + align:start position:0% +And um I guess I've forgotten already +what some of these are. + + align:start position:0% + + + + align:start position:0% + +But you can see what the whole picture + + align:start position:0% +But you can see what the whole picture + + + align:start position:0% +But you can see what the whole picture +starts to look like. + + align:start position:0% +starts to look like. + + + align:start position:0% +starts to look like. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Um, so let me actually I'm not going to + + align:start position:0% +Um, so let me actually I'm not going to + + + align:start position:0% +Um, so let me actually I'm not going to +um + + align:start position:0% +um + + + align:start position:0% +um +do these in detail, but + + align:start position:0% + + + + align:start position:0% + +let's just see how this the next stage + + align:start position:0% +let's just see how this the next stage + + + align:start position:0% +let's just see how this the next stage +would differ if at all. + + align:start position:0% + + + + align:start position:0% + +when I come to n equals 2, + + align:start position:0% + + + + align:start position:0% + +well, it's the same story all over + + align:start position:0% +well, it's the same story all over + + + align:start position:0% +well, it's the same story all over +again, + + align:start position:0% + + + + align:start position:0% + +right? So, whatever pattern of arrows I + + align:start position:0% +right? So, whatever pattern of arrows I + + + align:start position:0% +right? So, whatever pattern of arrows I +had coming out of here, I have the same + + align:start position:0% +had coming out of here, I have the same + + + align:start position:0% +had coming out of here, I have the same +pattern at the next stage with the same + + align:start position:0% +pattern at the next stage with the same + + + align:start position:0% +pattern at the next stage with the same +labels, right? Because there's nothing + + align:start position:0% +labels, right? Because there's nothing + + + align:start position:0% +labels, right? Because there's nothing +different. + + align:start position:0% + + + + align:start position:0% + +So, if you'll allow me, let me actually + + align:start position:0% +So, if you'll allow me, let me actually + + + align:start position:0% +So, if you'll allow me, let me actually +fill out a few of these. Um, + + align:start position:0% + + + + align:start position:0% + +and you'll get practice uh drawing one + + align:start position:0% +and you'll get practice uh drawing one + + + align:start position:0% +and you'll get practice uh drawing one +of these. these when you uh do + + align:start position:0% +of these. these when you uh do + + + align:start position:0% +of these. these when you uh do +recitation maybe for another uh example. + + align:start position:0% +recitation maybe for another uh example. + + + align:start position:0% +recitation maybe for another uh example. +So I I can keep going with these. Let's + + align:start position:0% +So I I can keep going with these. Let's + + + align:start position:0% +So I I can keep going with these. Let's +see here. This is going to be + + align:start position:0% + + + + align:start position:0% + +one one if I haven't found two arrows + + align:start position:0% +one one if I haven't found two arrows + + + align:start position:0% +one one if I haven't found two arrows +coming out of each box and I'm not done. + + align:start position:0% + + + + align:start position:0% + +Oh, this is wrong. Right. + + align:start position:0% +Oh, this is wrong. Right. + + + align:start position:0% +Oh, this is wrong. Right. +Thank you. + + align:start position:0% +Thank you. + + + align:start position:0% +Thank you. +from 01 I can go to one zero. + + align:start position:0% + + + + align:start position:0% + +Okay, so there are two arrows coming out + + align:start position:0% +Okay, so there are two arrows coming out + + + align:start position:0% +Okay, so there are two arrows coming out +of each one. The upper arrow corresponds + + align:start position:0% +of each one. The upper arrow corresponds + + + align:start position:0% +of each one. The upper arrow corresponds +to an input having been zero. The lower + + align:start position:0% +to an input having been zero. The lower + + + align:start position:0% +to an input having been zero. The lower +arrow um corresponds to an input having + + align:start position:0% +arrow um corresponds to an input having + + + align:start position:0% +arrow um corresponds to an input having +been one. + + align:start position:0% +been one. + + + align:start position:0% +been one. +And there are two arrows going into each + + align:start position:0% +And there are two arrows going into each + + + align:start position:0% +And there are two arrows going into each +box as well corresponding to whether the + + align:start position:0% +box as well corresponding to whether the + + + align:start position:0% +box as well corresponding to whether the +bit that's going to get dropped off is a + + align:start position:0% +bit that's going to get dropped off is a + + + align:start position:0% +bit that's going to get dropped off is a +zero or a one. All right. So there's a a + + align:start position:0% +zero or a one. All right. So there's a a + + + align:start position:0% +zero or a one. All right. So there's a a +real symmetry to this. + + align:start position:0% +real symmetry to this. + + + align:start position:0% +real symmetry to this. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +I'll draw one more stage just a little + + align:start position:0% +I'll draw one more stage just a little + + + align:start position:0% +I'll draw one more stage just a little +bit to make a point here. + + align:start position:0% + + + + align:start position:0% + +Okay, so you can keep going. + + align:start position:0% +Okay, so you can keep going. + + + align:start position:0% +Okay, so you can keep going. +So how do you generate a code word from + + align:start position:0% +So how do you generate a code word from + + + align:start position:0% +So how do you generate a code word from +a trellis diagram? + + align:start position:0% +a trellis diagram? + + + align:start position:0% +a trellis diagram? +You're starting in some state. + + align:start position:0% +You're starting in some state. + + + align:start position:0% +You're starting in some state. +Typically, it's the all zero state. In + + align:start position:0% +Typically, it's the all zero state. In + + + align:start position:0% +Typically, it's the all zero state. In +fact, what you'll usually do is have a + + align:start position:0% +fact, what you'll usually do is have a + + + align:start position:0% +fact, what you'll usually do is have a +header for your message stream, which is + + align:start position:0% +header for your message stream, which is + + + align:start position:0% +header for your message stream, which is +all zero. So you force the shift + + align:start position:0% +all zero. So you force the shift + + + align:start position:0% +all zero. So you force the shift +register to be in the zero state once + + align:start position:0% +register to be in the zero state once + + + align:start position:0% +register to be in the zero state once +the real message bits come in. Um, and + + align:start position:0% +the real message bits come in. Um, and + + + align:start position:0% +the real message bits come in. Um, and +then you move from here. So you're + + align:start position:0% +then you move from here. So you're + + + align:start position:0% +then you move from here. So you're +typically starting here and then you + + align:start position:0% +typically starting here and then you + + + align:start position:0% +typically starting here and then you +navigate depending on whether you've got + + align:start position:0% +navigate depending on whether you've got + + + align:start position:0% +navigate depending on whether you've got +a zero or a one. So if the first message + + align:start position:0% +a zero or a one. So if the first message + + + align:start position:0% +a zero or a one. So if the first message +bit is a one, you're going to go down + + align:start position:0% +bit is a one, you're going to go down + + + align:start position:0% +bit is a one, you're going to go down +here. If the next message bit is a zero, + + align:start position:0% +here. If the next message bit is a zero, + + + align:start position:0% +here. If the next message bit is a zero, +you're going to go up here. If the next + + align:start position:0% +you're going to go up here. If the next + + + align:start position:0% +you're going to go up here. If the next +message bit is a zero, you're going to + + align:start position:0% +message bit is a zero, you're going to + + + align:start position:0% +message bit is a zero, you're going to +go up there. And the code word that you + + align:start position:0% +go up there. And the code word that you + + + align:start position:0% +go up there. And the code word that you +emit is going to be in that case one one + + align:start position:0% +emit is going to be in that case one one + + + align:start position:0% +emit is going to be in that case one one +uh one zero one one and then all zeros, + + align:start position:0% +uh one zero one one and then all zeros, + + + align:start position:0% +uh one zero one one and then all zeros, +right? Assuming you're staying at zero + + align:start position:0% +right? Assuming you're staying at zero + + + align:start position:0% +right? Assuming you're staying at zero +from that one. So depending on what the + + align:start position:0% +from that one. So depending on what the + + + align:start position:0% +from that one. So depending on what the +message uh sequence is, you can actually + + align:start position:0% +message uh sequence is, you can actually + + + align:start position:0% +message uh sequence is, you can actually +go through the trellis. It's infinitely + + align:start position:0% +go through the trellis. It's infinitely + + + align:start position:0% +go through the trellis. It's infinitely +long or as long as your message sequence + + align:start position:0% +long or as long as your message sequence + + + align:start position:0% +long or as long as your message sequence +is um and figure out what the code word + + align:start position:0% +is um and figure out what the code word + + + align:start position:0% +is um and figure out what the code word +is that's emitted. So this is actually + + align:start position:0% +is that's emitted. So this is actually + + + align:start position:0% +is that's emitted. So this is actually +just a graphical way of displaying code + + align:start position:0% +just a graphical way of displaying code + + + align:start position:0% +just a graphical way of displaying code +words. + + align:start position:0% + + + + align:start position:0% + +So the set of code words that I get does + + align:start position:0% +So the set of code words that I get does + + + align:start position:0% +So the set of code words that I get does +that correspond to a linear code? Let's + + align:start position:0% +that correspond to a linear code? Let's + + + align:start position:0% +that correspond to a linear code? Let's +assume that somewhere downstream all + + align:start position:0% +assume that somewhere downstream all + + + align:start position:0% +assume that somewhere downstream all +these things come back down to zero. + + align:start position:0% +these things come back down to zero. + + + align:start position:0% +these things come back down to zero. +Okay. So I'm only considering a finite + + align:start position:0% + + + + align:start position:0% + +window of things. It's not going to go + + align:start position:0% +window of things. It's not going to go + + + align:start position:0% +window of things. It's not going to go +on forever. So suppose I'm going to end + + align:start position:0% +on forever. So suppose I'm going to end + + + align:start position:0% +on forever. So suppose I'm going to end +my input messages with 0 0 at the end + + align:start position:0% +my input messages with 0 0 at the end + + + align:start position:0% +my input messages with 0 0 at the end +and come back down to that state. So my + + align:start position:0% +and come back down to that state. So my + + + align:start position:0% +and come back down to that state. So my +messages will always start with 0 0 to + + align:start position:0% +messages will always start with 0 0 to + + + align:start position:0% +messages will always start with 0 0 to +force the register to the 00 state and + + align:start position:0% +force the register to the 00 state and + + + align:start position:0% +force the register to the 00 state and +they'll end with 0 0. Okay. Um the set + + align:start position:0% +they'll end with 0 0. Okay. Um the set + + + align:start position:0% +they'll end with 0 0. Okay. Um the set +of possible code words is a set of par + + align:start position:0% +of possible code words is a set of par + + + align:start position:0% +of possible code words is a set of par +bits I emit along the way as I navigate + + align:start position:0% +bits I emit along the way as I navigate + + + align:start position:0% +bits I emit along the way as I navigate +through the trellis. + + align:start position:0% +through the trellis. + + + align:start position:0% +through the trellis. +Is the set of code words + + align:start position:0% +Is the set of code words + + + align:start position:0% +Is the set of code words +does a set of code words constitute a + + align:start position:0% +does a set of code words constitute a + + + align:start position:0% +does a set of code words constitute a +linear code is the question + + align:start position:0% + + + + align:start position:0% + +maybe not obvious right + + align:start position:0% +maybe not obvious right + + + align:start position:0% +maybe not obvious right +the way you answer that is actually + + align:start position:0% +the way you answer that is actually + + + align:start position:0% +the way you answer that is actually +thinking back to uh this setting. So um + + align:start position:0% +thinking back to uh this setting. So um + + + align:start position:0% +thinking back to uh this setting. So um +one particular code word would + + align:start position:0% +one particular code word would + + + align:start position:0% +one particular code word would +correspond to a particular input + + align:start position:0% +correspond to a particular input + + + align:start position:0% +correspond to a particular input +sequence that generated it a particular + + align:start position:0% +sequence that generated it a particular + + + align:start position:0% +sequence that generated it a particular +data message sequence that generated it. + + align:start position:0% +data message sequence that generated it. + + + align:start position:0% +data message sequence that generated it. +Another code word would correspond to + + align:start position:0% +Another code word would correspond to + + + align:start position:0% +Another code word would correspond to +another message sequence and the + + align:start position:0% +another message sequence and the + + + align:start position:0% +another message sequence and the +question is is there a message sequence + + align:start position:0% +question is is there a message sequence + + + align:start position:0% +question is is there a message sequence +that would generate the sum of these two + + align:start position:0% +that would generate the sum of these two + + + align:start position:0% +that would generate the sum of these two +code words that you have and actually it + + align:start position:0% +code words that you have and actually it + + + align:start position:0% +code words that you have and actually it +turns out that it the answer is yes + + align:start position:0% +turns out that it the answer is yes + + + align:start position:0% +turns out that it the answer is yes +because these parity relationships are + + align:start position:0% +because these parity relationships are + + + align:start position:0% +because these parity relationships are +based on uh a nice linear operation. + + align:start position:0% +based on uh a nice linear operation. + + + align:start position:0% +based on uh a nice linear operation. +Okay, so it turns out that the set of + + align:start position:0% +Okay, so it turns out that the set of + + + align:start position:0% +Okay, so it turns out that the set of +code words that you generate + + align:start position:0% +code words that you generate + + + align:start position:0% +code words that you generate +um constitutes a linear code. + + align:start position:0% +um constitutes a linear code. + + + align:start position:0% +um constitutes a linear code. +So if you were going to think of + + align:start position:0% +So if you were going to think of + + + align:start position:0% +So if you were going to think of +uh a minimum Hamming distance for this + + align:start position:0% +uh a minimum Hamming distance for this + + + align:start position:0% +uh a minimum Hamming distance for this +code, what would what would you want to + + align:start position:0% +code, what would what would you want to + + + align:start position:0% +code, what would what would you want to +be thinking of? + + align:start position:0% + + + + align:start position:0% + +I don't know if I've actually drawn this + + align:start position:0% +I don't know if I've actually drawn this + + + align:start position:0% +I don't know if I've actually drawn this +correctly right now. Has anyone spotted + + align:start position:0% +correctly right now. Has anyone spotted + + + align:start position:0% +correctly right now. Has anyone spotted +any errors along the way or do I have it + + align:start position:0% +any errors along the way or do I have it + + + align:start position:0% +any errors along the way or do I have it +right? + + align:start position:0% + + + + align:start position:0% + +seems to be okay. + + align:start position:0% + + + + align:start position:0% + +What would cause how would you look for + + align:start position:0% +What would cause how would you look for + + + align:start position:0% +What would cause how would you look for +a minimum humming distance in the set of + + align:start position:0% +a minimum humming distance in the set of + + + align:start position:0% +a minimum humming distance in the set of +code words generated over this + + align:start position:0% +code words generated over this + + + align:start position:0% +code words generated over this +this window? + + align:start position:0% + + + + align:start position:0% + +Sorry, I didn't hear where that came + + align:start position:0% +Sorry, I didn't hear where that came + + + align:start position:0% +Sorry, I didn't hear where that came +from. Yeah. Could + + align:start position:0% + + + + align:start position:0% + +you could you speak up again? + + align:start position:0% +you could you speak up again? + + + align:start position:0% +you could you speak up again? +The minimum number of ones in a non-zero + + align:start position:0% +The minimum number of ones in a non-zero + + + align:start position:0% +The minimum number of ones in a non-zero +code word, right? Okay. So, it' be the + + align:start position:0% +code word, right? Okay. So, it' be the + + + align:start position:0% +code word, right? Okay. So, it' be the +weights the minimum weight code word + + align:start position:0% +weights the minimum weight code word + + + align:start position:0% +weights the minimum weight code word +you'd find among all the non-zero code + + align:start position:0% +you'd find among all the non-zero code + + + align:start position:0% +you'd find among all the non-zero code +words. So, you would have to find a path + + align:start position:0% +words. So, you would have to find a path + + + align:start position:0% +words. So, you would have to find a path +starting here. All my code words are + + align:start position:0% +starting here. All my code words are + + + align:start position:0% +starting here. All my code words are +going to start here and end there. You'd + + align:start position:0% +going to start here and end there. You'd + + + align:start position:0% +going to start here and end there. You'd +have to find a path through this that + + align:start position:0% +have to find a path through this that + + + align:start position:0% +have to find a path through this that +picks up the minimum number of ones. A + + align:start position:0% +picks up the minimum number of ones. A + + + align:start position:0% +picks up the minimum number of ones. A +path that's different from the all zeros + + align:start position:0% +path that's different from the all zeros + + + align:start position:0% +path that's different from the all zeros +path. Okay? Find the path through there + + align:start position:0% +path. Okay? Find the path through there + + + align:start position:0% +path. Okay? Find the path through there +which has the minimum number of ones in + + align:start position:0% +which has the minimum number of ones in + + + align:start position:0% +which has the minimum number of ones in +it in the code word. So what would that + + align:start position:0% +it in the code word. So what would that + + + align:start position:0% +it in the code word. So what would that +be + + align:start position:0% + + + + align:start position:0% + +in this particular case? + + align:start position:0% + + + + align:start position:0% + +Maybe this path we highlighted in + + align:start position:0% +Maybe this path we highlighted in + + + align:start position:0% +Maybe this path we highlighted in +another color. + + align:start position:0% + + + + align:start position:0% + +I don't have this is not a proof this is + + align:start position:0% +I don't have this is not a proof this is + + + align:start position:0% +I don't have this is not a proof this is +just a suggestion that this might be it + + align:start position:0% + + + + align:start position:0% + +and you you would have to draw in all + + align:start position:0% +and you you would have to draw in all + + + align:start position:0% +and you you would have to draw in all +the parts explore all the other parts + + align:start position:0% +the parts explore all the other parts + + + align:start position:0% +the parts explore all the other parts +but what would be the minimum weight + + align:start position:0% +but what would be the minimum weight + + + align:start position:0% +but what would be the minimum weight +along this one let's see I got one one + + align:start position:0% +along this one let's see I got one one + + + align:start position:0% +along this one let's see I got one one +there one zero here one one there so I + + align:start position:0% +there one zero here one one there so I + + + align:start position:0% +there one zero here one one there so I +would get a weight of five on this path + + align:start position:0% +would get a weight of five on this path + + + align:start position:0% +would get a weight of five on this path +and the question is whether you could + + align:start position:0% +and the question is whether you could + + + align:start position:0% +and the question is whether you could +find another path with a smaller number + + align:start position:0% +find another path with a smaller number + + + align:start position:0% +find another path with a smaller number +of ones attached to the code word um and + + align:start position:0% +of ones attached to the code word um and + + + align:start position:0% +of ones attached to the code word um and +I think if you work this out in detail + + align:start position:0% +I think if you work this out in detail + + + align:start position:0% +I think if you work this out in detail +and stare at it, you'll find that you're + + align:start position:0% +and stare at it, you'll find that you're + + + align:start position:0% +and stare at it, you'll find that you're +actually stuck with five. Okay. + + align:start position:0% +actually stuck with five. Okay. + + + align:start position:0% +actually stuck with five. Okay. +Now, it turns out that the + + align:start position:0% +Now, it turns out that the + + + align:start position:0% +Now, it turns out that the +interpretation of this number is not + + align:start position:0% +interpretation of this number is not + + + align:start position:0% +interpretation of this number is not +quite as straightforward as the + + align:start position:0% +quite as straightforward as the + + + align:start position:0% +quite as straightforward as the +interpretation of the minimum having + + align:start position:0% +interpretation of the minimum having + + + align:start position:0% +interpretation of the minimum having +distance in block codes. And the reason + + align:start position:0% +distance in block codes. And the reason + + + align:start position:0% +distance in block codes. And the reason +is that actually um this is a more + + align:start position:0% +is that actually um this is a more + + + align:start position:0% +is that actually um this is a more +complicated uh kind of picture because + + align:start position:0% +complicated uh kind of picture because + + + align:start position:0% +complicated uh kind of picture because +it continues on with the structure. Um, + + align:start position:0% +it continues on with the structure. Um, + + + align:start position:0% +it continues on with the structure. Um, +so we don't actually call it the minimum + + align:start position:0% +so we don't actually call it the minimum + + + align:start position:0% +so we don't actually call it the minimum +hanging distance, we call it the free + + align:start position:0% +hanging distance, we call it the free + + + align:start position:0% +hanging distance, we call it the free +distance. + + align:start position:0% + + + + align:start position:0% + +So I'm just trying to + + align:start position:0% +So I'm just trying to + + + align:start position:0% +So I'm just trying to +evoke this. So the um the minimum weight + + align:start position:0% +evoke this. So the um the minimum weight + + + align:start position:0% +evoke this. So the um the minimum weight +code word you find among the non-zero + + align:start position:0% +code word you find among the non-zero + + + align:start position:0% +code word you find among the non-zero +code words will indeed be a code word of + + align:start position:0% +code words will indeed be a code word of + + + align:start position:0% +code words will indeed be a code word of +weight five. But the interpretation of + + align:start position:0% +weight five. But the interpretation of + + + align:start position:0% +weight five. But the interpretation of +that number may not be directly as + + align:start position:0% +that number may not be directly as + + + align:start position:0% +that number may not be directly as +simple as in the case of the Hamming + + align:start position:0% +simple as in the case of the Hamming + + + align:start position:0% +simple as in the case of the Hamming +distance. Um, + + align:start position:0% + + + + align:start position:0% + +but it's close. Okay. So, what it really + + align:start position:0% +but it's close. Okay. So, what it really + + + align:start position:0% +but it's close. Okay. So, what it really +tells you is that over a data length + + align:start position:0% +tells you is that over a data length + + + align:start position:0% +tells you is that over a data length +that is + + align:start position:0% +that is + + + align:start position:0% +that is +maybe not much longer than this, + + align:start position:0% +maybe not much longer than this, + + + align:start position:0% +maybe not much longer than this, +the code words that you have are + + align:start position:0% +the code words that you have are + + + align:start position:0% +the code words that you have are +separated by + + align:start position:0% +separated by + + + align:start position:0% +separated by +this distance minimum. So you might + + align:start position:0% +this distance minimum. So you might + + + align:start position:0% +this distance minimum. So you might +expect that you could correct + + align:start position:0% +expect that you could correct + + + align:start position:0% +expect that you could correct +uh two two bit errors + + align:start position:0% +uh two two bit errors + + + align:start position:0% +uh two two bit errors +over data lengths that correspond to + + align:start position:0% +over data lengths that correspond to + + + align:start position:0% +over data lengths that correspond to +code words that are somewhat longer than + + align:start position:0% +code words that are somewhat longer than + + + align:start position:0% +code words that are somewhat longer than +this perhaps. Okay. Um so that's all + + align:start position:0% +this perhaps. Okay. Um so that's all + + + align:start position:0% +this perhaps. Okay. Um so that's all +very handwavy, but that's all we're + + align:start position:0% +very handwavy, but that's all we're + + + align:start position:0% +very handwavy, but that's all we're +going to do with the notion of free + + align:start position:0% +going to do with the notion of free + + + align:start position:0% +going to do with the notion of free +distance. So this is more complicated to + + align:start position:0% +distance. So this is more complicated to + + + align:start position:0% +distance. So this is more complicated to +deal with than a block code, but the + + align:start position:0% +deal with than a block code, but the + + + align:start position:0% +deal with than a block code, but the +free distance actually has that kind of + + align:start position:0% +free distance actually has that kind of + + + align:start position:0% +free distance actually has that kind of +intuition. It has the intuition of + + align:start position:0% +intuition. It has the intuition of + + + align:start position:0% +intuition. It has the intuition of +minimum having distance. um locally. All + + align:start position:0% +minimum having distance. um locally. All + + + align:start position:0% +minimum having distance. um locally. All +right, over this window of data, even if + + align:start position:0% +right, over this window of data, even if + + + align:start position:0% +right, over this window of data, even if +this went on for thousands of bits, if + + align:start position:0% +this went on for thousands of bits, if + + + align:start position:0% +this went on for thousands of bits, if +you got a burst of errors in this + + align:start position:0% +you got a burst of errors in this + + + align:start position:0% +you got a burst of errors in this +stretch that had up to two errors, you + + align:start position:0% +stretch that had up to two errors, you + + + align:start position:0% +stretch that had up to two errors, you +could correct them. And we haven't + + align:start position:0% +could correct them. And we haven't + + + align:start position:0% +could correct them. And we haven't +talked about the decoding. We're going + + align:start position:0% +talked about the decoding. We're going + + + align:start position:0% +talked about the decoding. We're going +to talk about that the next time. Okay. + + align:start position:0% +to talk about that the next time. Okay. + + + align:start position:0% +to talk about that the next time. Okay. +Um + + align:start position:0% + + + + align:start position:0% + +so that answers this piece. + + align:start position:0% + + + + align:start position:0% + +Now, let me say one thing about decoding + + align:start position:0% +Now, let me say one thing about decoding + + + align:start position:0% +Now, let me say one thing about decoding +just to set us up for next time. + + align:start position:0% +just to set us up for next time. + + + align:start position:0% +just to set us up for next time. +If I didn't have any noise + + align:start position:0% +If I didn't have any noise + + + align:start position:0% +If I didn't have any noise +in my channel, it actually turns out + + align:start position:0% +in my channel, it actually turns out + + + align:start position:0% +in my channel, it actually turns out +that decoding is pretty trivial. + + align:start position:0% +that decoding is pretty trivial. + + + align:start position:0% +that decoding is pretty trivial. +How is that? If I gave you the sequence + + align:start position:0% +How is that? If I gave you the sequence + + + align:start position:0% +How is that? If I gave you the sequence +of par bits, can you think of a way that + + align:start position:0% +of par bits, can you think of a way that + + + align:start position:0% +of par bits, can you think of a way that +you could recover the input sequence? + + align:start position:0% + + + + align:start position:0% + +Yeah, + + align:start position:0% + + + + align:start position:0% + +good. Yeah. You see, if I add these two, + + align:start position:0% +good. Yeah. You see, if I add these two, + + + align:start position:0% +good. Yeah. You see, if I add these two, +I get XN minus one equals P 0N + + align:start position:0% +I get XN minus one equals P 0N + + + align:start position:0% +I get XN minus one equals P 0N +plus P1N. + + align:start position:0% +plus P1N. + + + align:start position:0% +plus P1N. +So, if you give me the parity bit + + align:start position:0% +So, if you give me the parity bit + + + align:start position:0% +So, if you give me the parity bit +stream, I can reconstruct for you + + align:start position:0% +stream, I can reconstruct for you + + + align:start position:0% +stream, I can reconstruct for you +exactly the input with a onestep delay. + + align:start position:0% +exactly the input with a onestep delay. + + + align:start position:0% +exactly the input with a onestep delay. +That's pretty good. I'm happy with that. + + align:start position:0% +That's pretty good. I'm happy with that. + + + align:start position:0% +That's pretty good. I'm happy with that. +If if it's taken me uh you know minutes + + align:start position:0% +If if it's taken me uh you know minutes + + + align:start position:0% +If if it's taken me uh you know minutes +for the signal to reach me from Saturn, + + align:start position:0% +for the signal to reach me from Saturn, + + + align:start position:0% +for the signal to reach me from Saturn, +um I'm happy with a onestep delay here + + align:start position:0% +um I'm happy with a onestep delay here + + + align:start position:0% +um I'm happy with a onestep delay here +in decoding. All right. So in the + + align:start position:0% +in decoding. All right. So in the + + + align:start position:0% +in decoding. All right. So in the +absence of noise, the inversion is + + align:start position:0% +absence of noise, the inversion is + + + align:start position:0% +absence of noise, the inversion is +simple. The inversion meaning deducing + + align:start position:0% +simple. The inversion meaning deducing + + + align:start position:0% +simple. The inversion meaning deducing +the input message bits from the output, + + align:start position:0% +the input message bits from the output, + + + align:start position:0% +the input message bits from the output, +the parity bits. And this is a theme + + align:start position:0% +the parity bits. And this is a theme + + + align:start position:0% +the parity bits. And this is a theme +you'll see in many other settings. If + + align:start position:0% +you'll see in many other settings. If + + + align:start position:0% +you'll see in many other settings. If +there's no noise, inversion is easy. You + + align:start position:0% +there's no noise, inversion is easy. You + + + align:start position:0% +there's no noise, inversion is easy. You +can look at the output of a system and + + align:start position:0% +can look at the output of a system and + + + align:start position:0% +can look at the output of a system and +figure out what the input was. Um, if + + align:start position:0% +figure out what the input was. Um, if + + + align:start position:0% +figure out what the input was. Um, if +you know exactly how the system was + + align:start position:0% +you know exactly how the system was + + + align:start position:0% +you know exactly how the system was +creating the output from the input, but + + align:start position:0% +creating the output from the input, but + + + align:start position:0% +creating the output from the input, but +in the presence of noise, you've got a + + align:start position:0% +in the presence of noise, you've got a + + + align:start position:0% +in the presence of noise, you've got a +problem. Because you see, if you have + + align:start position:0% +problem. Because you see, if you have + + + align:start position:0% +problem. Because you see, if you have +these parity bits corrupted at some + + align:start position:0% +these parity bits corrupted at some + + + align:start position:0% +these parity bits corrupted at some +rate, every few bits you've got errors, + + align:start position:0% +rate, every few bits you've got errors, + + + align:start position:0% +rate, every few bits you've got errors, +well, your interpreted message is going + + align:start position:0% +well, your interpreted message is going + + + align:start position:0% +well, your interpreted message is going +to have that same kind of error rate. + + align:start position:0% +to have that same kind of error rate. + + + align:start position:0% +to have that same kind of error rate. +Okay? So, it's really in the presence of + + align:start position:0% +Okay? So, it's really in the presence of + + + align:start position:0% +Okay? So, it's really in the presence of +noise, it's an unsatisfactory way to do + + align:start position:0% +noise, it's an unsatisfactory way to do + + + align:start position:0% +noise, it's an unsatisfactory way to do +it. So, um, this doesn't work. We'll be + + align:start position:0% +it. So, um, this doesn't work. We'll be + + + align:start position:0% +it. So, um, this doesn't work. We'll be +looking at something more careful next + + align:start position:0% +looking at something more careful next + + + align:start position:0% +looking at something more careful next +time. Okay. So, we'll uh + + align:start position:0% +time. Okay. So, we'll uh + + + align:start position:0% +time. Okay. So, we'll uh +we'll well, actually, since I have you + + align:start position:0% +we'll well, actually, since I have you + + + align:start position:0% +we'll well, actually, since I have you +here, let me put up a spot for us. We + + align:start position:0% +here, let me put up a spot for us. We + + + align:start position:0% +here, let me put up a spot for us. We +haven't quite uh hit the mark. So, can + + align:start position:0% +haven't quite uh hit the mark. So, can + + + align:start position:0% +haven't quite uh hit the mark. So, can +you answer these for me? + + align:start position:0% +you answer these for me? + + + align:start position:0% +you answer these for me? +What's the constraint length of this + + align:start position:0% +What's the constraint length of this + + + align:start position:0% +What's the constraint length of this +code? + + align:start position:0% + + + + align:start position:0% + +Anyone + + align:start position:0% +Anyone + + + align:start position:0% +Anyone +who hasn't answered, yeah, four, right? + + align:start position:0% +who hasn't answered, yeah, four, right? + + + align:start position:0% +who hasn't answered, yeah, four, right? +Because you've got xn xn -1, xn -2, xnus + + align:start position:0% +Because you've got xn xn -1, xn -2, xnus + + + align:start position:0% +Because you've got xn xn -1, xn -2, xnus +3. That's the largest window over which + + align:start position:0% +3. That's the largest window over which + + + align:start position:0% +3. That's the largest window over which +you're uh picking things. What about the + + align:start position:0% +you're uh picking things. What about the + + + align:start position:0% +you're uh picking things. What about the +code rate? + + align:start position:0% + + + + align:start position:0% + +One over three, right? Because for every + + align:start position:0% +One over three, right? Because for every + + + align:start position:0% +One over three, right? Because for every +message bit, you're generating three + + align:start position:0% +message bit, you're generating three + + + align:start position:0% +message bit, you're generating three +parity bits. You're going to ship out + + align:start position:0% +parity bits. You're going to ship out + + + align:start position:0% +parity bits. You're going to ship out +those three parity bits before you do + + align:start position:0% +those three parity bits before you do + + + align:start position:0% +those three parity bits before you do +the shifting on the shift registers. So + + align:start position:0% +the shifting on the shift registers. So + + + align:start position:0% +the shifting on the shift registers. So +the code rate is one over three. The + + align:start position:0% +the code rate is one over three. The + + + align:start position:0% +the code rate is one over three. The +coefficients of the generators, of + + align:start position:0% +coefficients of the generators, of + + + align:start position:0% +coefficients of the generators, of +course, you can read up there. What + + align:start position:0% +course, you can read up there. What + + + align:start position:0% +course, you can read up there. What +about the number of states in the state + + align:start position:0% +about the number of states in the state + + + align:start position:0% +about the number of states in the state +machine here? + + align:start position:0% + + + + align:start position:0% + +what eight right because uh constraint + + align:start position:0% +what eight right because uh constraint + + + align:start position:0% +what eight right because uh constraint +length is four but one of those is the + + align:start position:0% +length is four but one of those is the + + + align:start position:0% +length is four but one of those is the +input so you've got three bits that + + align:start position:0% +input so you've got three bits that + + + align:start position:0% +input so you've got three bits that +you're storing in memory 2 to the 3 is + + align:start position:0% +you're storing in memory 2 to the 3 is + + + align:start position:0% +you're storing in memory 2 to the 3 is +eight so the number of states in the + + align:start position:0% +eight so the number of states in the + + + align:start position:0% +eight so the number of states in the +machine is three is eight okay so more + + align:start position:0% +machine is three is eight okay so more + + + align:start position:0% +machine is three is eight okay so more +complicated picture than this but the + + align:start position:0% +complicated picture than this but the + + + align:start position:0% +complicated picture than this but the +same principle all right we'll continue + + align:start position:0% +same principle all right we'll continue + + + align:start position:0% +same principle all right we'll continue +next \ No newline at end of file diff --git a/yzKPotFLfsc.txt b/yzKPotFLfsc.txt new file mode 100644 index 0000000000000000000000000000000000000000..342b6265bfa7802defb72957ca9c8e5102d23a65 --- /dev/null +++ b/yzKPotFLfsc.txt @@ -0,0 +1,2056 @@ +align:start position:0% + +let's continue our examination of G CDs + + align:start position:0% +let's continue our examination of G CDs + + + align:start position:0% +let's continue our examination of G CDs +and linear combinations and Euclidean + + align:start position:0% +and linear combinations and Euclidean + + + align:start position:0% +and linear combinations and Euclidean +algorithm by examining what's often + + align:start position:0% +algorithm by examining what's often + + + align:start position:0% +algorithm by examining what's often +called the extended Euclidean algorithm + + align:start position:0% +called the extended Euclidean algorithm + + + align:start position:0% +called the extended Euclidean algorithm +it's a good name for it it's ancient + + align:start position:0% +it's a good name for it it's ancient + + + align:start position:0% +it's a good name for it it's ancient +name for the dating back to ancient + + align:start position:0% +name for the dating back to ancient + + + align:start position:0% +name for the dating back to ancient +India is the pulverizer and we will see + + align:start position:0% +India is the pulverizer and we will see + + + align:start position:0% +India is the pulverizer and we will see +what that does in a moment so the + + align:start position:0% +what that does in a moment so the + + + align:start position:0% +what that does in a moment so the +theorem that is the culmination that + + align:start position:0% +theorem that is the culmination that + + + align:start position:0% +theorem that is the culmination that +we're aiming for is that the GCD of two + + align:start position:0% +we're aiming for is that the GCD of two + + + align:start position:0% +we're aiming for is that the GCD of two +numbers is an integer linear combination + + align:start position:0% +numbers is an integer linear combination + + + align:start position:0% +numbers is an integer linear combination +of the two numbers that is the GCD of a + + align:start position:0% +of the two numbers that is the GCD of a + + + align:start position:0% +of the two numbers that is the GCD of a +and B is simply s a plus TB or S&T are + + align:start position:0% +and B is simply s a plus TB or S&T are + + + align:start position:0% +and B is simply s a plus TB or S&T are +integers and what the polarizer enables + + align:start position:0% +integers and what the polarizer enables + + + align:start position:0% +integers and what the polarizer enables +us to do is give an a and B we can find + + align:start position:0% +us to do is give an a and B we can find + + + align:start position:0% +us to do is give an a and B we can find +SNT in fact we can find s in t virtually + + align:start position:0% +SNT in fact we can find s in t virtually + + + align:start position:0% +SNT in fact we can find s in t virtually +as fish as efficiently as a nucleating + + align:start position:0% +as fish as efficiently as a nucleating + + + align:start position:0% +as fish as efficiently as a nucleating +an algorithm is just by performing + + align:start position:0% +an algorithm is just by performing + + + align:start position:0% +an algorithm is just by performing +Euclidean algorithm and keeping track of + + align:start position:0% +Euclidean algorithm and keeping track of + + + align:start position:0% +Euclidean algorithm and keeping track of +some additional site information as it + + align:start position:0% +some additional site information as it + + + align:start position:0% +some additional site information as it +progresses + + align:start position:0% +progresses + + + align:start position:0% +progresses +now corollary of this fact is that we + + align:start position:0% +now corollary of this fact is that we + + + align:start position:0% +now corollary of this fact is that we +now know that the if we want to + + align:start position:0% +now know that the if we want to + + + align:start position:0% +now know that the if we want to +characterize the linear combinations of + + align:start position:0% +characterize the linear combinations of + + + align:start position:0% +characterize the linear combinations of +a and B they're precisely the multiples + + align:start position:0% +a and B they're precisely the multiples + + + align:start position:0% +a and B they're precisely the multiples +of the GCD of a and B that's because we + + align:start position:0% +of the GCD of a and B that's because we + + + align:start position:0% +of the GCD of a and B that's because we +know that every factor of both a and B + + align:start position:0% +know that every factor of both a and B + + + align:start position:0% +know that every factor of both a and B +defines any linear combination of a and + + align:start position:0% +defines any linear combination of a and + + + align:start position:0% +defines any linear combination of a and +B and therefore the GCD which is a + + align:start position:0% +B and therefore the GCD which is a + + + align:start position:0% +B and therefore the GCD which is a +factor of a and B divides any linear + + align:start position:0% +factor of a and B divides any linear + + + align:start position:0% +factor of a and B divides any linear +combination once we know so that means + + align:start position:0% +combination once we know so that means + + + align:start position:0% +combination once we know so that means +that that any or linea any linear + + align:start position:0% +that that any or linea any linear + + + align:start position:0% +that that any or linea any linear +combination is a multiple of the GCD of + + align:start position:0% +combination is a multiple of the GCD of + + + align:start position:0% +combination is a multiple of the GCD of +a and B of course once we know the GCD + + align:start position:0% +a and B of course once we know the GCD + + + align:start position:0% +a and B of course once we know the GCD +of a and B is itself a linear + + align:start position:0% +of a and B is itself a linear + + + align:start position:0% +of a and B is itself a linear +combination it means that you've got all + + align:start position:0% +combination it means that you've got all + + + align:start position:0% +combination it means that you've got all +of the linear combinations by taking + + align:start position:0% +of the linear combinations by taking + + + align:start position:0% +of the linear combinations by taking +multiples of the GCD okay how do we get + + align:start position:0% +multiples of the GCD okay how do we get + + + align:start position:0% +multiples of the GCD okay how do we get +S&T well the basic idea is that we're + + align:start position:0% +S&T well the basic idea is that we're + + + align:start position:0% +S&T well the basic idea is that we're +going to find these coefficients by + + align:start position:0% +going to find these coefficients by + + + align:start position:0% +going to find these coefficients by +applying the Euclidean algorithm and as + + align:start position:0% +applying the Euclidean algorithm and as + + + align:start position:0% +applying the Euclidean algorithm and as +we go we're going to be calculating + + align:start position:0% +we go we're going to be calculating + + + align:start position:0% +we go we're going to be calculating +efficient coefficients and eventually + + align:start position:0% +efficient coefficients and eventually + + + align:start position:0% +efficient coefficients and eventually +when we're all finished we'll wind up + + align:start position:0% +when we're all finished we'll wind up + + + align:start position:0% +when we're all finished we'll wind up +with the S&T specifically let's remember + + align:start position:0% +with the S&T specifically let's remember + + + align:start position:0% +with the S&T specifically let's remember +the euclidean algorithm starts off with + + align:start position:0% +the euclidean algorithm starts off with + + + align:start position:0% +the euclidean algorithm starts off with +with a and B and then it has two + + align:start position:0% +with a and B and then it has two + + + align:start position:0% +with a and B and then it has two +registers or numbers x and y that it + + align:start position:0% +registers or numbers x and y that it + + + align:start position:0% +registers or numbers x and y that it +keeps updating and the invariant is that + + align:start position:0% +keeps updating and the invariant is that + + + align:start position:0% +keeps updating and the invariant is that +the GCD of the x and y that are being + + align:start position:0% +the GCD of the x and y that are being + + + align:start position:0% +the GCD of the x and y that are being +continually updated by the Euclidean + + align:start position:0% +continually updated by the Euclidean + + + align:start position:0% +continually updated by the Euclidean +algorithm it stays the same as always + + align:start position:0% +algorithm it stays the same as always + + + align:start position:0% +algorithm it stays the same as always +the GCD of a and B so what we're going + + align:start position:0% +the GCD of a and B so what we're going + + + align:start position:0% +the GCD of a and B so what we're going +to do is just + + align:start position:0% +to do is just + + + align:start position:0% +to do is just +keep track of coefficients called them + + align:start position:0% +keep track of coefficients called them + + + align:start position:0% +keep track of coefficients called them +CDE and F such that the X whatever we're + + align:start position:0% +CDE and F such that the X whatever we're + + + align:start position:0% +CDE and F such that the X whatever we're +up to we know how to express as a linear + + align:start position:0% +up to we know how to express as a linear + + + align:start position:0% +up to we know how to express as a linear +combination of a and B and the Y that + + align:start position:0% +combination of a and B and the Y that + + + align:start position:0% +combination of a and B and the Y that +were whatever Y we're up to we can also + + align:start position:0% +were whatever Y we're up to we can also + + + align:start position:0% +were whatever Y we're up to we can also +express them as a linear combination of + + align:start position:0% +express them as a linear combination of + + + align:start position:0% +express them as a linear combination of +a and base so we're going to be keeping + + align:start position:0% +a and base so we're going to be keeping + + + align:start position:0% +a and base so we're going to be keeping +track of these four coefficients C D E + + align:start position:0% +track of these four coefficients C D E + + + align:start position:0% +track of these four coefficients C D E +and F that have this property this + + align:start position:0% +and F that have this property this + + + align:start position:0% +and F that have this property this +property is going to be another + + align:start position:0% +property is going to be another + + + align:start position:0% +property is going to be another +invariant of our extended Euclidean + + align:start position:0% +invariant of our extended Euclidean + + + align:start position:0% +invariant of our extended Euclidean +algorithm or pulverizer well how do we + + align:start position:0% +algorithm or pulverizer well how do we + + + align:start position:0% +algorithm or pulverizer well how do we +get initial values for a c d e and f + + align:start position:0% +get initial values for a c d e and f + + + align:start position:0% +get initial values for a c d e and f +well that's easy at the start X is a and + + align:start position:0% +well that's easy at the start X is a and + + + align:start position:0% +well that's easy at the start X is a and +so C is 1 and D is 0 because a is 1 a + + align:start position:0% +so C is 1 and D is 0 because a is 1 a + + + align:start position:0% +so C is 1 and D is 0 because a is 1 a +plus zero B similarly y is 0 a plus 1 B + + align:start position:0% +plus zero B similarly y is 0 a plus 1 B + + + align:start position:0% +plus zero B similarly y is 0 a plus 1 B +so we know what these values of c d e + + align:start position:0% +so we know what these values of c d e + + + align:start position:0% +so we know what these values of c d e +and f are at the start of the algorithm + + align:start position:0% +and f are at the start of the algorithm + + + align:start position:0% +and f are at the start of the algorithm +question is how do we update them + + align:start position:0% +question is how do we update them + + + align:start position:0% +question is how do we update them +well how does Euclidean how does a + + align:start position:0% +well how does Euclidean how does a + + + align:start position:0% +well how does Euclidean how does a +uclear work well remember at the next + + align:start position:0% +uclear work well remember at the next + + + align:start position:0% +uclear work well remember at the next +step the value of x is the old value of + + align:start position:0% +step the value of x is the old value of + + + align:start position:0% +step the value of x is the old value of +y so if I had the old value of y as ei + + align:start position:0% +y so if I had the old value of y as ei + + + align:start position:0% +y so if I had the old value of y as ei +plus FB then I clearly have a the next + + align:start position:0% +plus FB then I clearly have a the next + + + align:start position:0% +plus FB then I clearly have a the next +value of x as the same linear + + align:start position:0% +value of x as the same linear + + + align:start position:0% +value of x as the same linear +combination that Y you know that Y had + + align:start position:0% +combination that Y you know that Y had + + + align:start position:0% +combination that Y you know that Y had +preview then Y have previously what + + align:start position:0% +preview then Y have previously what + + + align:start position:0% +preview then Y have previously what +about Y next well at the next step the + + align:start position:0% +about Y next well at the next step the + + + align:start position:0% +about Y next well at the next step the +value of Y is simply the remainder of x + + align:start position:0% +value of Y is simply the remainder of x + + + align:start position:0% +value of Y is simply the remainder of x ++ y well the remainder of x + y remember + + align:start position:0% ++ y well the remainder of x + y remember + + + align:start position:0% ++ y well the remainder of x + y remember +is just X minus the quotient times y + + align:start position:0% +is just X minus the quotient times y + + + align:start position:0% +is just X minus the quotient times y +where the quotient is the quotient of X + + align:start position:0% +where the quotient is the quotient of X + + + align:start position:0% +where the quotient is the quotient of X +divided by Y so this is equal to the + + align:start position:0% +divided by Y so this is equal to the + + + align:start position:0% +divided by Y so this is equal to the +remainder of of x + y and that means + + align:start position:0% +remainder of of x + y and that means + + + align:start position:0% +remainder of of x + y and that means +that since I have Y since I also have X + + align:start position:0% +that since I have Y since I also have X + + + align:start position:0% +that since I have Y since I also have X +expressed as a linear combination this X + + align:start position:0% +expressed as a linear combination this X + + + align:start position:0% +expressed as a linear combination this X +minus qy is simply this linear + + align:start position:0% +minus qy is simply this linear + + + align:start position:0% +minus qy is simply this linear +combination for X minus the quotient + + align:start position:0% +combination for X minus the quotient + + + align:start position:0% +combination for X minus the quotient +number times the linear combination from + + align:start position:0% +number times the linear combination from + + + align:start position:0% +number times the linear combination from +Y well the difference of two linear + + align:start position:0% +Y well the difference of two linear + + + align:start position:0% +Y well the difference of two linear +combinations is a linear combination so + + align:start position:0% +combinations is a linear combination so + + + align:start position:0% +combinations is a linear combination so +just combining coefficients what I + + align:start position:0% +just combining coefficients what I + + + align:start position:0% +just combining coefficients what I +discover is that the way to express Y + + align:start position:0% +discover is that the way to express Y + + + align:start position:0% +discover is that the way to express Y +next as a linear combination of a and B + + align:start position:0% +next as a linear combination of a and B + + + align:start position:0% +next as a linear combination of a and B +is just to combine the previous + + align:start position:0% +is just to combine the previous + + + align:start position:0% +is just to combine the previous +coefficients C D E and F with the + + align:start position:0% +coefficients C D E and F with the + + + align:start position:0% +coefficients C D E and F with the +quotient in this way and that's all + + align:start position:0% +quotient in this way and that's all + + + align:start position:0% +quotient in this way and that's all +there is to it well let's work out an + + align:start position:0% +there is to it well let's work out an + + + align:start position:0% +there is to it well let's work out an +example to see how it goes suppose that + + align:start position:0% +example to see how it goes suppose that + + + align:start position:0% +example to see how it goes suppose that +a is $8.99 and B is 493 this was a + + align:start position:0% +a is $8.99 and B is 493 this was a + + + align:start position:0% +a is $8.99 and B is 493 this was a +number that we had previous that we had + + align:start position:0% +number that we had previous that we had + + + align:start position:0% +number that we had previous that we had +previously applied the Euclidean + + align:start position:0% +previously applied the Euclidean + + + align:start position:0% +previously applied the Euclidean +algorithm to so now what we're doing is + + align:start position:0% +algorithm to so now what we're doing is + + + align:start position:0% +algorithm to so now what we're doing is +observing I need to I'm going to begin + + align:start position:0% +observing I need to I'm going to begin + + + align:start position:0% +observing I need to I'm going to begin +by calculating the remainder but this + + align:start position:0% +by calculating the remainder but this + + + align:start position:0% +by calculating the remainder but this +time when calculating the remainder + + align:start position:0% +time when calculating the remainder + + + align:start position:0% +time when calculating the remainder +let's keep track of the quotient so I'm + + align:start position:0% +let's keep track of the quotient so I'm + + + align:start position:0% +let's keep track of the quotient so I'm +gonna find the remainder of 899 divided + + align:start position:0% +gonna find the remainder of 899 divided + + + align:start position:0% +gonna find the remainder of 899 divided +by 493 its 406 and the quotient is 1 + + align:start position:0% +by 493 its 406 and the quotient is 1 + + + align:start position:0% +by 493 its 406 and the quotient is 1 +that is 899 is 1 times 493 + 406 what + + align:start position:0% +that is 899 is 1 times 493 + 406 what + + + align:start position:0% +that is 899 is 1 times 493 + 406 what +does that tell me well 406 then is + + align:start position:0% +does that tell me well 406 then is + + + align:start position:0% +does that tell me well 406 then is +remember 899 is a and 493 is B we're + + align:start position:0% +remember 899 is a and 493 is B we're + + + align:start position:0% +remember 899 is a and 493 is B we're +tell I'm discovering that the first + + align:start position:0% +tell I'm discovering that the first + + + align:start position:0% +tell I'm discovering that the first +remainder 406 is 1 times a plus minus 1 + + align:start position:0% +remainder 406 is 1 times a plus minus 1 + + + align:start position:0% +remainder 406 is 1 times a plus minus 1 +times B so now I have that first + + align:start position:0% +times B so now I have that first + + + align:start position:0% +times B so now I have that first +remainder expressed as the desired + + align:start position:0% +remainder expressed as the desired + + + align:start position:0% +remainder expressed as the desired +linear combination of a and B well + + align:start position:0% +linear combination of a and B well + + + align:start position:0% +linear combination of a and B well +what's next + + align:start position:0% +what's next + + + align:start position:0% +what's next +well now that I've got 406 and 493 I'm + + align:start position:0% +well now that I've got 406 and 493 I'm + + + align:start position:0% +well now that I've got 406 and 493 I'm +supposed to take the remainder of 493 + + align:start position:0% +supposed to take the remainder of 493 + + + align:start position:0% +supposed to take the remainder of 493 +divided by 406 well that's 87 in fact + + align:start position:0% +divided by 406 well that's 87 in fact + + + align:start position:0% +divided by 406 well that's 87 in fact +493 as a quotient of 1 times 406 plus + + align:start position:0% +493 as a quotient of 1 times 406 plus + + + align:start position:0% +493 as a quotient of 1 times 406 plus +eighty seven so that tells me that 87 is + + align:start position:0% +eighty seven so that tells me that 87 is + + + align:start position:0% +eighty seven so that tells me that 87 is +this number minus that number 87 is 493 + + align:start position:0% +this number minus that number 87 is 493 + + + align:start position:0% +this number minus that number 87 is 493 +- 406 yeah well remember 493 is B so 87 + + align:start position:0% +- 406 yeah well remember 493 is B so 87 + + + align:start position:0% +- 406 yeah well remember 493 is B so 87 +is 1 times B minus 1 times 406 but wait + + align:start position:0% +is 1 times B minus 1 times 406 but wait + + + align:start position:0% +is 1 times B minus 1 times 406 but wait +wait wait look up here 406 I know how to + + align:start position:0% +wait wait look up here 406 I know how to + + + align:start position:0% +wait wait look up here 406 I know how to +express it as a linear combination of a + + align:start position:0% +express it as a linear combination of a + + + align:start position:0% +express it as a linear combination of a +and B so let's replace the 406 by 1 a + + align:start position:0% +and B so let's replace the 406 by 1 a + + + align:start position:0% +and B so let's replace the 406 by 1 a +plus minus 1 B and what I'm gonna wind + + align:start position:0% +plus minus 1 B and what I'm gonna wind + + + align:start position:0% +plus minus 1 B and what I'm gonna wind +up with remember it's a it's a minus + + align:start position:0% +up with remember it's a it's a minus + + + align:start position:0% +up with remember it's a it's a minus +minus so I wind up contributing an A and + + align:start position:0% +minus so I wind up contributing an A and + + + align:start position:0% +minus so I wind up contributing an A and +an extra B and I wind up with a minus a + + align:start position:0% +an extra B and I wind up with a minus a + + + align:start position:0% +an extra B and I wind up with a minus a +plus 2 being said that roughly but the a + + align:start position:0% +plus 2 being said that roughly but the a + + + align:start position:0% +plus 2 being said that roughly but the a +is getting negated you can check my + + align:start position:0% +is getting negated you can check my + + + align:start position:0% +is getting negated you can check my +algebra so there we are with the linear + + align:start position:0% +algebra so there we are with the linear + + + align:start position:0% +algebra so there we are with the linear +combination expresses the next remainder + + align:start position:0% +combination expresses the next remainder + + + align:start position:0% +combination expresses the next remainder +87 all right let's continue after this + + align:start position:0% +87 all right let's continue after this + + + align:start position:0% +87 all right let's continue after this +what we're supposed to do is find the + + align:start position:0% +what we're supposed to do is find the + + + align:start position:0% +what we're supposed to do is find the +quotient of 406 by by 87 of and the + + align:start position:0% +quotient of 406 by by 87 of and the + + + align:start position:0% +quotient of 406 by by 87 of and the +remainder so when you divide 406 by 87 + + align:start position:0% +remainder so when you divide 406 by 87 + + + align:start position:0% +remainder so when you divide 406 by 87 +you get a quotient of 4 in a remainder + + align:start position:0% +you get a quotient of 4 in a remainder + + + align:start position:0% +you get a quotient of 4 in a remainder +of 58 which means the remainder 58 is + + align:start position:0% +of 58 which means the remainder 58 is + + + align:start position:0% +of 58 which means the remainder 58 is +406 minus 4 times + + align:start position:0% +406 minus 4 times + + + align:start position:0% +406 minus 4 times + + align:start position:0% + + + align:start position:0% +but now looking above I have the + + align:start position:0% +but now looking above I have the + + + align:start position:0% +but now looking above I have the +coefficients of 406 for a and B and I + + align:start position:0% +coefficients of 406 for a and B and I + + + align:start position:0% +coefficients of 406 for a and B and I +have the coefficients for 87 for a and B + + align:start position:0% +have the coefficients for 87 for a and B + + + align:start position:0% +have the coefficients for 87 for a and B +here and so I have to multiply those by + + align:start position:0% +here and so I have to multiply those by + + + align:start position:0% +here and so I have to multiply those by +4 and I wind up that the way to express + + align:start position:0% +4 and I wind up that the way to express + + + align:start position:0% +4 and I wind up that the way to express +58 in terms of a and B is it's 5a plus + + align:start position:0% +58 in terms of a and B is it's 5a plus + + + align:start position:0% +58 in terms of a and B is it's 5a plus +minus 9 B and now next I'm supposed to + + align:start position:0% +minus 9 B and now next I'm supposed to + + + align:start position:0% +minus 9 B and now next I'm supposed to +find the remainder of of 87 divided by + + align:start position:0% +find the remainder of of 87 divided by + + + align:start position:0% +find the remainder of of 87 divided by +58 the quotients 1 the remainder is 29 + + align:start position:0% +58 the quotients 1 the remainder is 29 + + + align:start position:0% +58 the quotients 1 the remainder is 29 +and that means that 29 is 1 times 87 + + align:start position:0% +and that means that 29 is 1 times 87 + + + align:start position:0% +and that means that 29 is 1 times 87 +minus 1 times 58 looking back I see how + + align:start position:0% +minus 1 times 58 looking back I see how + + + align:start position:0% +minus 1 times 58 looking back I see how +to express 87 in terms of a and B and 58 + + align:start position:0% +to express 87 in terms of a and B and 58 + + + align:start position:0% +to express 87 in terms of a and B and 58 +in terms of a and B I can just combine + + align:start position:0% +in terms of a and B I can just combine + + + align:start position:0% +in terms of a and B I can just combine +those expressions to wind up with 29 is + + align:start position:0% +those expressions to wind up with 29 is + + + align:start position:0% +those expressions to wind up with 29 is +-6 times a plus 11 times B next I have + + align:start position:0% +-6 times a plus 11 times B next I have + + + align:start position:0% +-6 times a plus 11 times B next I have +to take the quotient of 58 divided by 29 + + align:start position:0% +to take the quotient of 58 divided by 29 + + + align:start position:0% +to take the quotient of 58 divided by 29 +while the the quotient is 2 but the cool + + align:start position:0% +while the the quotient is 2 but the cool + + + align:start position:0% +while the the quotient is 2 but the cool +thing now is the remainder is 0 that's + + align:start position:0% +thing now is the remainder is 0 that's + + + align:start position:0% +thing now is the remainder is 0 that's +the stopping condition for the Euclidean + + align:start position:0% +the stopping condition for the Euclidean + + + align:start position:0% +the stopping condition for the Euclidean +algorithm it means that the answer is 29 + + align:start position:0% +algorithm it means that the answer is 29 + + + align:start position:0% +algorithm it means that the answer is 29 +there's no remainder anymore so the GCD + + align:start position:0% +there's no remainder anymore so the GCD + + + align:start position:0% +there's no remainder anymore so the GCD +of 29 and 0 is 29 the final GCD then we + + align:start position:0% +of 29 and 0 is 29 the final GCD then we + + + align:start position:0% +of 29 and 0 is 29 the final GCD then we +finished is 29 but look what we got in + + align:start position:0% +finished is 29 but look what we got in + + + align:start position:0% +finished is 29 but look what we got in +the last step I had expressed that GCD + + align:start position:0% +the last step I had expressed that GCD + + + align:start position:0% +the last step I had expressed that GCD +as a linear combination of a and B and + + align:start position:0% +as a linear combination of a and B and + + + align:start position:0% +as a linear combination of a and B and +that's the pulverizer I've just figured + + align:start position:0% +that's the pulverizer I've just figured + + + align:start position:0% +that's the pulverizer I've just figured +out that possible values for s nter + + align:start position:0% +out that possible values for s nter + + + align:start position:0% +out that possible values for s nter +minus 6 and 11 and this is a perfectly + + align:start position:0% +minus 6 and 11 and this is a perfectly + + + align:start position:0% +minus 6 and 11 and this is a perfectly +general procedure that will always give + + align:start position:0% +general procedure that will always give + + + align:start position:0% +general procedure that will always give +you coefficients S&T that express the + + align:start position:0% +you coefficients S&T that express the + + + align:start position:0% +you coefficients S&T that express the +GCD of a and B in terms of a and B now + + align:start position:0% +GCD of a and B in terms of a and B now + + + align:start position:0% +GCD of a and B in terms of a and B now +sometimes it's technically convenient to + + align:start position:0% +sometimes it's technically convenient to + + + align:start position:0% +sometimes it's technically convenient to +be able to control which of the + + align:start position:0% +be able to control which of the + + + align:start position:0% +be able to control which of the +coefficients are positive and which + + align:start position:0% +coefficients are positive and which + + + align:start position:0% +coefficients are positive and which +negative clearly if you're going to + + align:start position:0% +negative clearly if you're going to + + + align:start position:0% +negative clearly if you're going to +combine a and B that are both positive + + align:start position:0% +combine a and B that are both positive + + + align:start position:0% +combine a and B that are both positive +numbers and wind up with a positive + + align:start position:0% +numbers and wind up with a positive + + + align:start position:0% +numbers and wind up with a positive +number by with a smaller number by + + align:start position:0% +number by with a smaller number by + + + align:start position:0% +number by with a smaller number by +adding multiples of them one of those + + align:start position:0% +adding multiples of them one of those + + + align:start position:0% +adding multiples of them one of those +coefficients has to be negative so in + + align:start position:0% +coefficients has to be negative so in + + + align:start position:0% +coefficients has to be negative so in +this case we had the coefficient of 89 + + align:start position:0% +this case we had the coefficient of 89 + + + align:start position:0% +this case we had the coefficient of 89 +was minus 6 and the coefficient of B was + + align:start position:0% +was minus 6 and the coefficient of B was + + + align:start position:0% +was minus 6 and the coefficient of B was +11 and suppose + + align:start position:0% +11 and suppose + + + align:start position:0% +11 and suppose +that I wanted though the first + + align:start position:0% +that I wanted though the first + + + align:start position:0% +that I wanted though the first +coefficient of a to be the positive + + align:start position:0% +coefficient of a to be the positive + + + align:start position:0% +coefficient of a to be the positive +number and the other one to be negative + + align:start position:0% +number and the other one to be negative + + + align:start position:0% +number and the other one to be negative +why how can I do that well there's a + + align:start position:0% +why how can I do that well there's a + + + align:start position:0% +why how can I do that well there's a +pretty trivial little trick for doing + + align:start position:0% +pretty trivial little trick for doing + + + align:start position:0% +pretty trivial little trick for doing +that's ingenious button but it's + + align:start position:0% +that's ingenious button but it's + + + align:start position:0% +that's ingenious button but it's +immediately verifiable how do I get a + + align:start position:0% +immediately verifiable how do I get a + + + align:start position:0% +immediately verifiable how do I get a +positive coefficient for $8.99 well + + align:start position:0% +positive coefficient for $8.99 well + + + align:start position:0% +positive coefficient for $8.99 well +there's a general way to get new a + + align:start position:0% +there's a general way to get new a + + + align:start position:0% +there's a general way to get new a +coefficients okay if you look at minus-6 + + align:start position:0% +coefficients okay if you look at minus-6 + + + align:start position:0% +coefficients okay if you look at minus-6 +899 plus eleven 493 if I add any + + align:start position:0% +899 plus eleven 493 if I add any + + + align:start position:0% +899 plus eleven 493 if I add any +multiple of 493 to the first coordinate + + align:start position:0% +multiple of 493 to the first coordinate + + + align:start position:0% +multiple of 493 to the first coordinate +and I subtract the same multiple of 899 + + align:start position:0% +and I subtract the same multiple of 899 + + + align:start position:0% +and I subtract the same multiple of 899 +for the second coordinate all I'm doing + + align:start position:0% +for the second coordinate all I'm doing + + + align:start position:0% +for the second coordinate all I'm doing +is adding 493 times K times 899 to the + + align:start position:0% +is adding 493 times K times 899 to the + + + align:start position:0% +is adding 493 times K times 899 to the +first term and I'm subtracting 493 times + + align:start position:0% +first term and I'm subtracting 493 times + + + align:start position:0% +first term and I'm subtracting 493 times +899 times K from the second term they + + align:start position:0% +899 times K from the second term they + + + align:start position:0% +899 times K from the second term they +cancel out so this linear combination is + + align:start position:0% +cancel out so this linear combination is + + + align:start position:0% +cancel out so this linear combination is +going to be the same as that one it's + + align:start position:0% +going to be the same as that one it's + + + align:start position:0% +going to be the same as that one it's +gonna be the same GCD but now I'm by + + align:start position:0% +gonna be the same GCD but now I'm by + + + align:start position:0% +gonna be the same GCD but now I'm by +adding in any multiple by the way K + + align:start position:0% +adding in any multiple by the way K + + + align:start position:0% +adding in any multiple by the way K +could be positive or negative of 493 I + + align:start position:0% +could be positive or negative of 493 I + + + align:start position:0% +could be positive or negative of 493 I +can make the positive I can make the + + align:start position:0% +can make the positive I can make the + + + align:start position:0% +can make the positive I can make the +first coefficient as big or as small as + + align:start position:0% +first coefficient as big or as small as + + + align:start position:0% +first coefficient as big or as small as +I like in particular if I want it to be + + align:start position:0% +I like in particular if I want it to be + + + align:start position:0% +I like in particular if I want it to be +positive might as well take the smallest + + align:start position:0% +positive might as well take the smallest + + + align:start position:0% +positive might as well take the smallest +value of K that works which is one so if + + align:start position:0% +value of K that works which is one so if + + + align:start position:0% +value of K that works which is one so if +I let K be one I discover that I add 493 + + align:start position:0% +I let K be one I discover that I add 493 + + + align:start position:0% +I let K be one I discover that I add 493 +to minus 6 I get 487 and I subtract 11 I + + align:start position:0% +to minus 6 I get 487 and I subtract 11 I + + + align:start position:0% +to minus 6 I get 487 and I subtract 11 I +subtract 899 from 11 I get minus 8 88 + + align:start position:0% +subtract 899 from 11 I get minus 8 88 + + + align:start position:0% +subtract 899 from 11 I get minus 8 88 +and there we are with another expression + + align:start position:0% +and there we are with another expression + + + align:start position:0% +and there we are with another expression +for this time s is 487 and T is minus + + align:start position:0% +for this time s is 487 and T is minus + + + align:start position:0% +for this time s is 487 and T is minus +888 and the second one is negative and + + align:start position:0% +888 and the second one is negative and + + + align:start position:0% +888 and the second one is negative and +the first one is positive it's going to + + align:start position:0% +the first one is positive it's going to + + + align:start position:0% +the first one is positive it's going to +turn out that this little trick will + + align:start position:0% +turn out that this little trick will + + + align:start position:0% +turn out that this little trick will +enable us in a in the next video to come + + align:start position:0% +enable us in a in the next video to come + + + align:start position:0% +enable us in a in the next video to come +up with a general solution to the + + align:start position:0% +up with a general solution to the + + + align:start position:0% +up with a general solution to the +diehard bucket problem which is fun but + + align:start position:0% +diehard bucket problem which is fun but + + + align:start position:0% +diehard bucket problem which is fun but +let's finish up the current story and + + align:start position:0% +let's finish up the current story and + + + align:start position:0% +let's finish up the current story and +the remark is that the pulverizer is + + align:start position:0% +the remark is that the pulverizer is + + + align:start position:0% +the remark is that the pulverizer is +really another very efficient algorithm + + align:start position:0% +really another very efficient algorithm + + + align:start position:0% +really another very efficient algorithm +exactly the way the Euclidean algorithm + + align:start position:0% +exactly the way the Euclidean algorithm + + + align:start position:0% +exactly the way the Euclidean algorithm +is efficient it's basically got the same + + align:start position:0% +is efficient it's basically got the same + + + align:start position:0% +is efficient it's basically got the same +number of transitions when you update + + align:start position:0% +number of transitions when you update + + + align:start position:0% +number of transitions when you update +the pair X Y to get a new pair Y + + align:start position:0% +the pair X Y to get a new pair Y + + + align:start position:0% +the pair X Y to get a new pair Y +remainder of X divided by Y so it's + + align:start position:0% +remainder of X divided by Y so it's + + + align:start position:0% +remainder of X divided by Y so it's +taking logged twice log to the base 2 + + align:start position:0% +taking logged twice log to the base 2 + + + align:start position:0% +taking logged twice log to the base 2 +number of transitions log to the base + + align:start position:0% +number of transitions log to the base + + + align:start position:0% +number of transitions log to the base +would be transition so it's + + align:start position:0% +would be transition so it's + + + align:start position:0% +would be transition so it's +exponentially efficient it's working in + + align:start position:0% +exponentially efficient it's working in + + + align:start position:0% +exponentially efficient it's working in +the binary the lengthened binary of the + + align:start position:0% +the binary the lengthened binary of the + + + align:start position:0% +the binary the lengthened binary of the +number B of course there's a few more + + align:start position:0% +number B of course there's a few more + + + align:start position:0% +number B of course there's a few more +additions and multiplications per + + align:start position:0% +additions and multiplications per + + + align:start position:0% +additions and multiplications per +transition for the extended GCD that + + align:start position:0% +transition for the extended GCD that + + + align:start position:0% +transition for the extended GCD that +with the pulverizer than the ordinary + + align:start position:0% +with the pulverizer than the ordinary + + + align:start position:0% +with the pulverizer than the ordinary +Euclidean algorithm so big deal it means + + align:start position:0% +Euclidean algorithm so big deal it means + + + align:start position:0% +Euclidean algorithm so big deal it means +that the number of total arithmetic + + align:start position:0% +that the number of total arithmetic + + + align:start position:0% +that the number of total arithmetic +operations of adds adds and multiplies + + align:start position:0% +operations of adds adds and multiplies + + + align:start position:0% +operations of adds adds and multiplies +is proportional to the log to the base 2 + + align:start position:0% +is proportional to the log to the base 2 + + + align:start position:0% +is proportional to the log to the base 2 +of B I said here 6 I think it's actually + + align:start position:0% +of B I said here 6 I think it's actually + + + align:start position:0% +of B I said here 6 I think it's actually +like 10 but the main thing is it's a + + align:start position:0% +like 10 but the main thing is it's a + + + align:start position:0% +like 10 but the main thing is it's a +small constant times the log to the base + + align:start position:0% +small constant times the log to the base + + + align:start position:0% +small constant times the log to the base +2 of B the pulverizer is a very + + align:start position:0% +2 of B the pulverizer is a very + + + align:start position:0% +2 of B the pulverizer is a very +efficient algorithm as well as the + + align:start position:0% +efficient algorithm as well as the + + + align:start position:0% +efficient algorithm as well as the +Euclidean algorithm and those are going + + align:start position:0% +Euclidean algorithm and those are going + + + align:start position:0% +Euclidean algorithm and those are going +to be crucial facts that will build on \ No newline at end of file diff --git a/zKtYCGbCfSc.txt b/zKtYCGbCfSc.txt new file mode 100644 index 0000000000000000000000000000000000000000..fa672854676d8d76ce07eefe84bbd9b9d6727ab1 --- /dev/null +++ b/zKtYCGbCfSc.txt @@ -0,0 +1,2294 @@ +GUEST SPEAKER: The following +content is provided under a + +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation, or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +HERBERT GROSS: Hi. + +Our lecture today involves the +backbone of Calculus, namely + +the concept of limit, and +perhaps no place in the + +history of mathematics is there +a more subtle topic than + +this particular one. + +I'm reminded of the anecdote +of the professor who was + +staring quite intently, +philosophically, in his home, + +and his wife asked, what are +you contemplating, and he + +said, that it's amazing +how electricity works. + +And the wife said, well what's +so amazing about that? + +All you have to do is +flick the switch. + +And this somehow or other is +exactly the predicament that + +the limit concept falls into. + +From the point of view of +computation, it seems that + +what comes naturally 99% of the +time gives us the right + +answer, but unfortunately, the +1% of the time turns up almost + +all the time in differential +Calculus. + +For this reason, what we will do +is introduce the concept of + +limit through the eyes of +differential Calculus, and we + +shall call our lecture today +'Derivatives and Limits'. + +And what we shall do is go back +to our old friend who + +makes an appearance in almost +all of our lectures so far, + +the case of the freely +falling object. + +A ball is dropped. + +It falls freely in a vacuum, and +the distance, 's', that it + +falls in feet, at the end of 't' +seconds, is given by 's' + +equals '16t squared'. + +The question that we would like +to raise is, how fast is + +the ball falling when +'t' equals one? + +In other words, notice that +the ball is covering a + +different distance +here as it falls. + +What we want to know is at the +instant that the time is one. + +And by the way, don't confuse +the speed with the + +displacement. + +We know that when the time is +one, the object has fallen a + +distance of 16 feet. + +When the time is 1, the object +has fallen 16 feet. + +What we want to know is how +fast is it falling at that + +particular point. + +Now keep in mind that +mathematics being a logical + +subject proceeds from the idea +of trying to study the + +unfamiliar in terms +of the familiar. + +What we are familiar with is the +concept known as average + +rate of speed. + +So what we will do is duck the +main question temporarily and + +proceed to a different +question. + +What we shall ask is, what is +the average speed of the ball + +during the time interval from t +equals one to t equals two? + +And we all know how to solve +this problem from our + +pre-calculus courses, namely, +we compute where the ball is + +when 't' is two. + +We compute where the ball +was when 't' is one. + +The difference between these two +distances is the distance + +that the ball has fallen during +this time interval, and + +we then divide by the +time interval. + +And the distance divided by +the time is precisely the + +definition of average +rate of speed. + +In other words, during the time +interval from 't' equals + +one to 't' equals two, the ball +falls at an average speed + +of 48 feet per second. + +Again, in terms of our diagram, +you see at 't' equals + +one, the object is over here. + +At 't' equals two, the object +is over here, it's fallen 64 + +feet, and so we compute the +average speed by taking the + +total distance and dividing +by the time that it took. + +Now again, what we have done is +found the right answer, but + +to the wrong question. + +The question was not what was +the average rate of speed from + +'t' equals one to 't' equals +two, it was, what is the speed + +at the instant 't' equals one? + +And we sense that between 't' +equals one and 't' equals two, + +an awful lot can happen, and +that therefore, our average + +speed need not be a good +approximation for the + +instantaneous speed. + +What we do next, you see, is we +say OK, let's do something + +a little bit differently. + +Let's now compute the average +speed, but not from 't' equals + +one to 't' equals two, but +rather from 't' equals one to + +'t' equals 1.1. + +And computationally, we mimic +the same procedure as before. + +We compute 's' when 't' +is 1.1, we compute + +'s' when 't' is one. + +By the way, the only difference +is that it's a + +little bit tougher to square +1.1 and multiply that by 16 + +than it was to square two +and multiply that by 16. + +The arithmetic gets slightly +messier if you want to call it + +that, but the concept +stays the same. + +We find the total distance +traveled during the time + +interval, we divide by the +length of the time interval, + +and that quotient, by +definition, is the average + +rate of speed. + +Again, in terms of our diagram, +at t equals one, the + +object has fallen 16 feet. + +I'll distort this so that we can +see what's happening here. + +At 't' equals 1.1, the object +has fallen 19.36 feet, and now + +we compute the average speed +from here to here in the usual + +high school way. + +Now again, the same question +arises as before, namely, this + +is still an average speed. + +We wanted an instantaneous +speed. + +And our come back is to say look +at, we at least suspect + +intuitively that between one and +1.1, we will hopefully get + +a better idea as to what's +happening at exactly one than + +when we did on the bigger +interval from one to two. + +In other words, whereas we don't +believe that 33.6 is the + +answer to our original question, +we do believe that + +33.6 is probably a better +approximation to the answer to + +our original question than the +answer 48 feet per second that + +was obtained over the +larger interval. + +What the mathematician does next +is he says well, let's + +stop playing games. + +Let's not go between one and +1.1, or one and 1.01. + +Why don't we go between one and +'1+h', where 'h' is any + +non-zero amount? + +In other words, let's find the +average speed from 't' equals + +one to 't' equals '1+h', and +then what we'll do is we will + +investigate to see what +happens when h + +gets very, very small. + +Well again, we mimic exactly +our procedure before. + +We feed in 't' equals '1+h' +and compute 's', which of + +course is '16 times +'1+h' squared'. + +Then we subtract off the +distance that the particle had + +fallen when 't' is one, that's +16 feet, we divide by the + +length of the time interval. + +Well between one and '1+h', the +time interval is 'h', we + +simplify algebraically, and we +wind up with this particular + +expression, '32h plus 16h +squared' over 'h'. + +And now we come to the crux of +what limits, and derivatives, + +and instantaneous rate of +speeds are all about. + +If you recall, it's quite +tempting to look at this thing + +and say, ah-ha, I'll cancel an +'h' from both the numerator + +and the denominator, and that +will leave me '32 plus 16h'. + +And notice though, the very +important thing, that as we + +mentioned in previous lectures, +since you cannot + +divide by 0, it is crucial at +this stage that we emphasize + +that 'h' is not equal to 0. + +Now of course, this +is not a difficult + +rationalization to make. + +Namely, in terms of our +physical situation, we + +wouldn't want to compute an +average rate of speed over a + +time interval during which +no time transpired. + +And if we let 'h' be 0, +obviously, from one to '1+h', + +no time transpires. + +But the key statement is, and +we'll come back to exploit + +this not only for this lecture, +but for the next one + +too, is to exploit the idea that +in our entire discussion, + +it was crucial that h not +be allowed to equal 0. + +In other words, the average +speed between one and '1+h' is + +'32 plus 16h'. + +Now again, without trying to be +rigorous, observe that our + +senses tell us that as 'h' gets +us close to 0 as we want + +without ever being allowed to +get there, '16h' gets us close + +to 0 as we want also, and +hence, '32 plus 16h' + +apparently gets us close +to 32 as we wish. + +In other words, it appears that +the speed is 32 feet per + +second when t equals one. + +And to reuse the vernacular, +what we're saying is we + +compute the average +rate of speed-- + +see 's' of '1+h' minus +'s' of '1/h'-- + +and see what happens to that +as 'h' approaches 0. + +And in our particular case, +notice that this + +simply means what? + +We came down to '32 plus 16h' +over here, and then as 'h' got + +arbitrarily small, we became +suspicious, and believed that + +as 'h' became arbitrarily +small, '32 + +plus 16h' became 32. + +And I'm saying that in great +detail because this is not + +quite nearly as harmless +as it may seem. + +There is a great deal of +difficulty involved in just + +saying as 'h' gets close +to 0, '32 plus 16h' + +gets close to 32. + +Well there's no difficulty +in saying it. + +There's difficulty that comes up +in trying to show what this + +means precisely, as we shall +see in just a little while. + +By the way, it's rather easy +to generalize this result. + +Namely, you may have noticed in +our presentation there was + +nothing sacred about asking what +was the speed when 't' + +equals one. + +One could just as easily have +chosen any other time 't', say + +'t sub one', and asked what was +the speed between 't1' and + +'t1' plus 'h'? + +We could have done exactly +the same computation. + +In fact, notice down here, when +we do this computation, + +the answer '32t one' plus '16h' +becomes precisely '32 + +plus 16h when 't' one +happens to be one. + +In other words, this result here +is the generalization of + +our previous result that +had us work with the + +limit of '32 plus 16h'. + +At any rate, by this approach, +it becomes clear then, if the + +equation of motion, the distance +versus the time, is + +given by 's' equals '16t +squared', then that time 't' + +equals 't one', the +instantaneous speed appears to + +be 32 times 't' one. + +And in fact, since 't' one +happens to be any arbitrary + +time that we choose, it is +customary to drop the + +subscript, and simply +say what? + +At any time, 't', our freely +falling body in this case, + +will have a speed +given by '32t'. + +And many of us will remember, as +this is a revisited course, + +that this is precisely the +recipe that turns out when one + +talks about bringing down +the exponent and + +replacing it by one less. + +16 times two is 32, and 't' to +a power one less than two is + +just t to the first +power or 't'. + +But notice now, no recipes +involved here. + +Just a question of intuitively +defining instantaneous speed + +in terms of being a limit +of average speeds. + +Now in order that we don't +become hypocrites in what + +we're doing, recall also that +we have spent an entire + +lecture talking about the value +of analytic Geometry in + +the study of Calculus. + +The idea that a picture +is worth 1,000 words. + +So what we would like to do now +is to revisit our previous + +discussion in terms +of a graph. + +You see, suppose we have a curve +'y' equals 'f of x', and + +I've drawn the curve over +on this side over here. + +We'll make more reference to it +later as we go along, but + +what does it mean if I now +mechanically compute 'f of x1 + +' plus 'delta x' minus 'f +of x1' over 'delta x'? + +And by the way, again, notice +just a question of symbolism. + +'Delta x' happens to be the +conventional symbol that one + +uses in the analytical Geometry +approach where we + +were using h before, +but this is simply + +a question of notation. + +Well the idea is this: observe +that if we go to the graph, 'f + +of x1' plus 'delta x' is +this particular height. + +On the other hand, this +height is 'f of x1' . + +Consequently, our numerator is +just this distance here, and + +our denominator, which is +'delta x', is just this + +distance here. + +And therefore, what we have done +in our quotient, is we + +have found the slope of the +straight line that joins 'p' + +to 'q.' And here then is why the +question of straight line + +becomes so important +in the study of + +differential Calculus. + +That what is average speed, in +terms of analysis, becomes the + +slope of a straight line +in terms of Geometry. + +And the idea, you see, is that +this gives me the average + +speed of the straight line that +joins the average rise of + +the straight line that +joins 'p' to 'q'. + +And by the way, this is quite +deceptive as any average is. + +It's like the man who sat with +his feet in the oven and an + +ice pack on his head, and when +somebody said how do you feel, + +he said, on the average, +pretty good. + +You see, the same thing is +happening over here. + +Notice if I had taken a +completely different curve, a + +curve which looked nothing at +all like my original curve, + +only that also passed through +the points 'p' and 'q', notice + +that even though these two +curves are quite different, + +the average rise from +'p' to 'q' is the + +same for both curves. + +In other words, when one deals +with the average, one is not + +too concerned with how one +got from the first + +point to the second. + +You see, this is the problem +with average rate of space. + +In fact, the bigger a time +interval we work over, the + +more danger there is that the +average rate of speed will not + +coincide intuitively with what +we would like to believe that + +the instantaneous rate +of speed is. + +And you see, that's exactly +what this idea here means. + +What we do to define the +derivative, the instantaneous + +rise at 'x' equals 'x1' , is +we take this quotient and + +investigate what happens to it +as 'delta x' is allowed to get + +arbitrarily close to 0. + +But let's emphasize +this again. + +'Delta x' is not allowed +to equal 0. + +You see, it's over a smaller and +smaller interval, and you + +see what's happening +here geometrically? + +To let 'delta x' get smaller and +smaller means, that for a + +given 'x1' , you are holding 'p' +fixed, and allowing 'q' to + +move in closer and +closer to 'p'. + +And what we are saying is, is +that when 'q' assumes this + +position, let's call it 'q sub +1', the slope of the line that + +joints 'p' to 'q' one looks a +lot more like the slope of the + +line that will be tangent to +the curve at the point 'p'. + +And for this reason, what is +instantaneous rate of speed, + +when we're talking about +functions, become slopes of + +curves at a given point when we +are talking about curves. + +You see that the tangent line to +a curve is viewed as being + +the limiting position of a cord +drawn from a point 'p' to + +a point 'q'. + +Now at any rate, this will be +emphasized in the text. + +It will be emphasized +in our exercises. + +The major issue now is what did +we really do when it came + +time to compute this +little gadget. + +In other words, when we talked +about the limit of 'f of x' as + +'x' approached 'a', how +did we compute this? + +The danger is, and this is why +I have underlined a question + +mark here, the intuitive +approach is to say something + +like, let's just replace +x by a in here. + +In other words, let the limit of +'f of x', as 'x' approaches + +'a', be 'f of a'. + +In fact, this is what we did +with our '32 plus 16h'. + +In a way, what we did was, with +'32 plus 16h', do you + +remember what we did? + +We said, let's let 'h' get +arbitrarily close to 0. + +And in our minds, we +let 'h' equal 0. + +'16h' was then 0, and then '32 +plus 16h' was then 32. + +But what we had done is somehow +or other, if our + +intuition is correct, we had +arrived at the correct answer + +but for wrong reasons. + +Because you see, in this +expression, it is mandatory, + +as we've outlined this, +is that 'x' never be + +allowed to equal 'a'. + +Well you say, who cares +whether you + +allow it or you don't? + +Aren't we going to get +the same answer? + +And just to give you a quickie, +one that we talked + +about in our introductory +lecture, consider the function + +'f of x' to be 'x squared +minus nine' + +over 'x minus three'. + +And let's evaluate what +this limit is as + +'x' approaches three. + +If we were to blindly assume +that all we have to do is + +replace 'x' by 'a', that +would mean what here? + +Replace 'x' by three. + +Notice that what +we got is what? + +Three squared, which is nine, +minus nine, (which is 0) over + +three minus three, +which is also 0. + +In other words, if in the +expression 'x squared minus + +nine' over 'x minus three' you +replace 'x' by three, you do + +get 0 over 0. + +Unfortunately, or perhaps +fortunately, somehow or other, + +this definition is supposed to +incorporate the fact that you + +never allow 'x' to +equal three. + +See, the way we got 0 over 0 +was we violated what the + +intuitive meaning +of limit was. + +We wound up with this 0 over 0 +mess by allowing 'x' to equal + +the one value it is not +allowed to equal here. + +To see what happened more +anatomically in this + +particular problem, let's go +back to our old friend of + +cancellation again. + +We observe that 'x squared minus +nine' can be written as + +'x plus three' times 'x minus +three', and then we divide by + +'x minus three', and here's +where the main problem seems + +to come up. + +One automatically, somehow or +other, gets into the habit of + +canceling these things out. + +But the point is, since we have +already agreed that you + +cannot divide by 0, the idea +then becomes that the only + +time this is permissible is when +'x' is unequal to three. + +In fact, to have been more +precise, what we should have + +said was not that 'x squared +minus nine' over 'x minus + +three' equals 'x plus three', +but rather, 'x squared minus + +nine' over 'x minus three' +equals 'x plus three', unless + +'x' equals three. + +And by the way, I should +add here what? + +That if 'x' equals three, then +'x squared minus nine' over 'x + +minus three' is undefined. + +You see, that's what +we call 0 over 0. + +Undefined, indeterminate. + +But here's what bails us out. + +As soon as we say the limit as +'x' approaches three, what are + +we assuming? + +We're assuming that 'x' can be +any value at all except three, + +and the interesting point now +becomes, that as long as 'x' + +is anything but three, the only +time you could tell these + +two expressions apart was when +'x' happened to equal three. + +So if you now say we won't allow +'x' to equal three, then + +it is true, whereas the +bracketed expression by itself + +is not equal to the +parenthetical + +expression by itself. + +The limit as 'x' approaches +three of these two expressions + +are equal, and in fact, one +becomes tempted to say "what?" + +at this case. + +Oh, here it's quite easy to see, +that as 'x' approaches + +three, 'x plus three' +is equal to six. + +And let me put a question mark +here also, because it + +certainly is true that if you +replace 'x' by three, this + +will be six. + +But this says don't replace +'x' by three. + +Now before, when we replaced +'x' by three we got into + +trouble, so we said +we can't do that. + +Now we replace 'x' by three, we +get an answer that we like, + +and that is the danger that +we'll say OK, we won't allow + +this to be done, unless +we like the result. + +And of course this gives you +a highly subjective subject + +matter here. + +You see, the point is that +somehow or other we must come + +up with a more objective +criteria for distinguishing + +what limits are. + +And by the way, for the Polyanna +who has the intuitive + +feeling for saying things like +well look at, this may give + +you trouble if you wind +up with 0 over 0. + +But what is the likelihood that +given 'f of x' at random, + +and 'a' at random, that the +limit of 'f of x' as 'x' + +approaches 'a' is going to be +0 over 0 if you're careless? + +And the answer is that the +probability is quite small, + +except in Calculus, in which +case, every time, you take a + +derivative. + +Every time you are going to +wind up with 0 over 0. + +This is why we said earlier that +differential Calculus has + +been referred to as 'the +study of 0 over 0'. + +You see, the whole point is, +let's go back now to our basic + +definition of average rate of +change of 'f', 'f of x1' plus + +'delta x' minus 'f of +x1' over 'delta x'. + +I guess when you're writing in +black, you have to use white + +for emphasis, so +we'll use this. + +Notice that every time you let +'delta x' equal zero, you are + +going to wind up with what? + +'f of x1' minus 'f of x1' , +which is 0, over 'delta x', + +which is 0. + +In other words, you are +going to get 0 over 0. + +If you believe that all this +means is to replace 'delta x' + +by 0, you see, and the point is, +this is not the definition + +of this, and this is why you +don't wind up with this + +particular thing. + +Well I've spent enough time, +I think, trying to give a + +picture as to what limits mean +intuitively, now what I'd like + +to do is to devote the remainder +of this lecture, + +plus our next one, to +investigating, more + +stringently, what limit means in +a way that is unambiguous. + +And you know, it's like +everything else in this world. + +When you want to get something +that is ironclad, you don't + +get something for nothing. + +To get an ironclad expression +that doesn't lend itself to + +misinterpretations usually +involves a rigorous enough + +language that scares off +the uninitiated. + +Sort of like a legal document. + +The chances are if you're not +a trained lawyer, and the + +document is simple enough for +you to understand, it must + +have thousands of +loopholes in it. + +But that same rigorous language +that makes it almost + +impossible for the layman to +understand what's happening, + +is precisely the language that +the lawyer needs to make the + +document well defined +to him, hopefully. + +Well with that as a background, +let's now try to + +give a more rigorous definition +of limit. + +And let's try to do it in such +a way that not only will the + +definition be rigorous, but it +will agree, to the best of our + +ability, with what we +intuitively believe a limit + +should mean. + +Now what I want to do here is +scare you a little bit, and + +the reason I want to scare you +a little bit is, I want to + +show you, once and for all, +how in many cases, what + +appears to be ominous +mathematical notation, is + +simply a rigorous way of saying +something which was + +quite intuitive pictorially +to do. + +The mathematical definition +of limit is the following. + +The limit of 'f of x' as 'x' +approaches 'a' equals 'l' + +means, and get this, given +epsilon greater than 0, we can + +find delta greater than 0, such +that when the absolute + +value of 'x minus a' is less +than delta, but greater than + +0, then the absolute value of +'f of x' minus 'l' is less + +than epsilon. + +Now doesn't that kind +of turn you on? + +See, this is the +whole problem. + +I will now cut you in sort of on +the trade secret that makes + +this thing very, +very readable. + +First of all, to say that you +want to get arbitrarily close + +in value, you want 'f of x' to +be arbitrarily close to 'l', + +another way of saying +that is what? + +You specify any tolerance limit +whatsoever, which we + +call epsilon, and I can make 'f +of x' get to within epsilon + +of 'l' just by choosing 'x' +sufficiently close to 'a'. + +And by the way again, in terms +of geometry, that's all the + +absolute value of a +difference means. + +The absolute value of 'x minus +a' simply means what? + +The distance between +'x' and 'a'. + +All this says is what? + +I can make 'f of x' fall within +epsilon of 'l' by + +finding a delta such that 'x' is +within delta of 'a', and by + +the way, this little tidbit over +here is simply a fancy + +way of saying that you're not +letting 'x' equal 'a'. + +You see, the only way the +absolute value of a number can + +be 0 is if the number +itself is 0. + +The only way this could be 0 +is if 'x' equals 'a', so by + +saying this little tidbit over +here, that this is greater + +than 0, that's our fancy way +of saying that we are not + +going to allow 'x' +to equal to 'a'. + +Now again, whereas this may +sound a little bit simpler + +than the original definition, +let's see how much easier the + +picture makes it. + +Let's go to a graph of +'y' equals 'f of x'. + +And in my diagram here, here is +'a', and here is 'l', and + +what I'm saying is, I +intuitively suspect. + +Let me write down +what I suspect. + +I suspect that the limit of 'f +of x', as 'x' approaches 'a', + +is 'l' in this case. + +Namely I suspect that as 'x' +gets closer and closer to 'a', + +no matter which side you come +in on, that's why we use + +absolute value. + +It makes no difference whether +it's positive or negative. + +As 'x' gets in tighter and +tighter on 'a', I suspect that + +I can make 'f of x' come +arbitrarily equal to 'l'. + +In other words, if 'x' is close +enough to 'a', 'f of x', + +it seems, will be +close to 'l'. + +And by the way, to complete this +problem geometrically, + +pick your epsilon. + +Let's say that epsilon is this +'y', and since epsilon is + +positive, this will be called +'l plus epsilon'. + +This will be called +'l minus epsilon'. + +Now what we do is we come +over to the curve here. + +All right, hopefully these +will look like horizontal + +lines to you. + +When I get down to here, I then +project down vertical + +lines to meet the x-axis. + +And now all I'm saying, and I +think this is fairly intuitive + +clear, is what? + +That if 'x' is this close to +'a', 'f of x' will be within + +these tolerance limits of 'l'. + +In other words, for any value of +'x' in here, see, for this + +neighborhood of 'a', every +input has its output come + +within epsilon of 'l'. + +By the way, just one brief +note here, something that + +we'll have to come back to in +more detail-- in fact, I'll do + +that in our next example-- + +notice here how important it +was that our curve was not + +single value, but one to one. + +In other words, suppose our +curve had doubled back, say + +something like this. + +Notice then, when you try to +project over to the curve from + +'l plus epsilon', you don't know +whether to stop at this + +point or at this point. + +You see, in other words, notice +that there is another + +point down here which has the +same 'l plus epsilon' value. + +In other words, whenever our +function is not one to one, + +there is going to be a +problem, when we work + +analytically, of being able to +solve algebraic equations, and + +trying to distinguish this point +of intersection from + +this point. + +You see, if we made a mistake +and bypass this point and came + +all the way over to here, and +thought that this was our + +tolerance limit, we would be in +a great deal of difficulty. + +Because you see, for example, +for this value of 'x', its 'f + +of x' value projects up here, +which is outside of the + +tolerance limits +that are given. + +You see, many things which are +self evident from the picture + +are not nearly so self evident +analytically, to which we then + +raise the question, why +use analysis at all? + +Let's just use pictures. + +And again the answer is, in +this case, we can get away + +with it, but in more complicated +situations where + +either we can't draw the diagram +because it's too + +complicated, or because we have +several variables, and we + +get into a dimension problem, +the point is that sometimes we + +have no recourse other +than the analysis. + +Let me give you an exercise +that we'll do in terms of + +putting the geometry and the +analysis side by side. + +Let's look at the expression the +limit of 'x squared minus + +2x' as 'x' approaches three. + +Now of course, we don't want 'x' +to equal three here, but + +let's cheat again, and see +what this thing means. + +Our intuition tells us that when +'x' is three, 'x squared' + +is nine, '2x' is six. + +So nine minus six is three, and +we would suspect that the + +limit here should be three. + +Now to see what this means, +let's draw a little diagram. + +The graph 'y' equals 'x squared +minus 2x' crosses the + +x-axis at 0 and two. + +It has its low point at the +0.1 comma minus one. + +We can sketch these curves, +it's a parabola. + +And now what we're saying is, is +it true that when 'x' gets + +very close to three, +that 'f of x' gets + +very close to three? + +And the answer is, from the +diagram, it appears very + +obvious that this is the case. + +Fact, here's that example of +non-single value again. + +If you call this thing 'l', +and you now pick tolerance + +limits which we'll call 'l plus +epsilon' and 'l minus + +epsilon', and now you want to +see what interval you need on + +the x-axis, notice that in this +particular diagram, you + +will get two intervals, one of +which surrounds the value 'x' + +equals minus one, and the other +of which surrounds the + +'x' value 'x' equals three. + +In other words, both when 'x' is +minus one and 'x' is three, + +'x squared minus 2x' +will equal three. + +At any rate, leaving the diagram +as an aid, let's see + +what our epsilon delta +definition says, and how we + +handle the stuff algebraically, +and how we + +correlate the algebra +with the geometry. + +Given epsilon greater than +0, what must I do? + +I must find a delta greater +than 0 such that, and I'm + +going to read this colloquially, +I'll write it + +formally, but read it +colloquially, such that + +whenever 'x' is within delta +of three, but not equal to + +three, then 'x squared +minus 2x' will be + +within epsilon of three. + +Now here's the whole point. + +We know, algebraically, how +to handle absolute values. + +Namely, the absolute value of +'x squared minus 2x minus + +three' being less than epsilon, +is the same as saying + +that 'x squared minus 2x minus +three' itself must be between + +epsilon and minus epsilon. + +Now again, we rewrite things +in fancy ways if we wish. + +There other ways +of doing this. + +I call this completing +the square. + +Well, people for 2,000 years +have called this completing + +the square. + +Namely, I rewrite minus three as +one minus four, so that 'x + +squared minus 2x plus one' +can be factored as + +'x minus one squared'. + +I'm now down to this +form here. + +Then I add four to all sides +of my inequality, and have + +that 'x minus one squared' is +between four plus epsilon and + +four minus epsilon. + +Some fairly elementary Algebra +of inequalities here. + +Now here's the key point. + +Remembering my diagram, I said +to you, how do we know whether + +we're near three or +near minus one? + +How do we distinguish, when we +draw the lines to the curve, + +what neighborhood we want? + +And notice that all we're saying +is that if 'x' is near + +three, that means what? +'x' is close to three. + +If 'x' is reasonably close to +three, then 'x minus one' is + +going to be reasonably close to +two, and hence be positive. + +Point is, that as long as you're +dealing with positive + +numbers over here, see if +epsilon is sufficiently small, + +these will then all be +positive numbers. + +For positive numbers, if the +squares obey a certain + +inequality, the square roots +will obey the same inequality, + +as we have emphasized in +one of our exercises. + +In other words, from here, we +can now say this, and from + +this, we can now conclude, that +if you want 'x squared + +minus 2x' to be within epsilon +of three, 'x' itself is going + +to have to be between 'one plus +the square root of 'four + +plus epsilon'', and 'one +plus the square root + +of 'four minus epsilon''. + +And by the way, this is quite +rigorous, but I don't think it + +turns you on. + +I don't think there's any +picture that you associate + +with this, and so what I thought +I'd like to do for our + +next little thing, is to come +back to our diagram here, and + +show you what this +really means. + +Namely, notice that if epsilon +is a small positive number, + +let's take a look +at this again. + +If epsilon is a small positive +number, this is + +slightly less than four. + +Therefore, the square root is +slightly less than two, + +therefore, this number will be +slightly less than three. + +On the other hand, 'four plus +epsilon' is slightly more than + +four, so its square root will be +slightly more than two, and + +therefore, one plus that square +root will be slightly + +more than three. + +And what these two numbers, as +abstract as they look like, + +correspond to, is nothing +more than this. + +Coming back to our diagram and +choosing an epsilon, and + +coming over to the curve like +this, and projecting down like + +this, all we're saying is, +see, what are we saying + +pictorially? + +That for 'f of x' to be within +epsilon of 'l', 'x' itself has + +to be in this range here. + +And all this says is, this very +simple point to compute, + +just by projecting down like +this, its rigorous name would + +be 'one plus the square root +of 'four minus epsilon''. + +That's this number over here. + +And the furthest point, namely +this point here, which again, + +in terms of the picture is very +easy to find, that point + +corresponds to one plus +the square root + +of 'four plus epsilon'. + +And again notice, in terms +of the Algebra, I need no + +recourse to a picture. + +But in terms of the picture, I +get a heck of a good feeling + +as to what these abstract +symbols are telling me. + +Well let's continue on with the +solution of this exercise. + +You see, we didn't want to find +where 'x' was, we wanted + +to see where 'x minus +three' had to be. + +In other words, we're trying +to find the delta. + +We know that 'x minus three' +is between these + +two extremes here. + +Consequently, and here's a place +we have to be a little + +bit careful here, this of +course, is a positive number, + +because this is more than two. + +This, on the other hand, is a +negative number, because you + +see 'four minus epsilon' is less +than four, so its square + +root is less than two. + +So if I subtract two from-- +it's a negative number-- + +and since delta has to be +positive, if this thing is + +negative, two minus the square +root of 'four minus epsilon' + +will be positive. + +So what I do is, to solve this +problem, is I simply choose + +delta to be the minimum +of these two numbers. + +And then by definition, +what do I have? + +That when the absolute value +of 'x minus three' is less + +than delta, and at the same +time, this is crucial, + +greater than 0. + +In other words, we never +let 'x' equal three. + +For this choice of delta, by how +we worked backwards, this + +will come out to be +less than epsilon. + +And that is exactly what you +mean by our formal definition + +of saying that the limit of 'x +squared minus 2x' as 'x' + +approaches three, in this +case, equals three. + +For someone who wants more +concrete evidence, I think all + +one has to do is, for example, +take a number like 'one plus + +the square root of 'four plus +epsilon'', that is the widest + +point on our interval, and +actually plug that in for 'x', + +and go through this computation +of squaring 'one + +plus the square root of +'four plus epsilon''. + +Subtract twice, 'one plus +the square root + +of 'four plus epsilon''. + +Carry out that computation +and you get what? + +'Three plus epsilon'. + +That using the upper extreme, +you wind up with what? + +In excess of three by epsilon, +which by the way is exactly + +what's supposed to happen. + +In fact, I hope this doesn't +give you an eye sore, I will + +pull down the top board again +to show you also what these + +two distances mean, and +what this means. + +You see, all these two numbers +mean is the following, and + +I'll pull this down just +far enough to see it. + +That these two numbers were the +widths from this end point + +to three on the one extreme, +and from this end point to + +three on the other extreme. + +In other words, those two +numbers that we took the + +minimum of were the half-width +intervals + +that surrounded three. + +You see the problem, as we +mentioned before is, is that + +even though epsilon and minus +epsilon are symmetric with + +respect to 'l', when you +translate over to the curve, + +because this curve is not a +straight line when you project + +down, these two widths +will not be equal. + +By picking the minimum of +these two widths, you + +guarantee that you have +locked yourself inside + +the required area. + +You see, that's all this +particular thing means. + +Now the trouble is that one +might now get the idea that + +there are no shorter ways of +doing the same problem. + +You see, I showed you +a rigorous way. + +There was no law that said we +had to find the biggest delta. + +In other words, if delta equals, +a half will work, in + +other words, if you're within +a half of three, something's + +going to happen, then certainly +any smaller number + +will work just as well. + +In other words, I can +get estimates. + +Let me show you what +I mean by that. + +Another way of tackling how to +make 'x squared minus 2x minus + +three' smaller than epsilon is +to use our properties of + +absolute values, and +to factor this. + +In other words, we know that +'x squared minus 2x minus + +three' is 'x minus three' +times 'x plus one'. + +We know that the absolute +value of a product is a + +product of the absolute values, +so these two things + +here are synonyms. Then we +know that near 'x' equals + +three, which we're interested +in here, 'x plus + +one' is near four. + +Well what we mean more +rigorously is this, choose an + +epsilon, and if the absolute +value of 'x minus three' is + +less than epsilon, in other +words, if 'x minus three' is + +less than epsilon but greater +than minus epsilon, then by + +adding on four to all three +sides of the inequality here, + +we see that 'x plus one' is less +than 'four plus epsilon', + +but greater than 'four +minus epsilon'. + +If the size of epsilon is less +than one, then certainly this + +is less than five, and this +is greater than three. + +Now of course, somebody may say +to us, but what if epsilon + +is more than one? + +Well obviously, if a guy says +make this thing within 10, and + +I can make it within one, +certainly within + +10 is within one. + +I can always pick the +smaller number. + +It's like that nonsense of the +fellow asking for an ice cream + +cone, and the waitress said +what flavor, and he said + +anything except chocolate. + +And she said, I'm all out of +chocolate, will you take + +anything except vanilla? + +The idea here is that if +somebody says make this less + +than 15, if you've made it less +than 10, in particular, + +you've made it less than 15. + +And so all we do over +here, you see, is + +something like this. + +We say look it, if we want to +make this number here very + +small, we know that this number +here is less than five, + +we know that 'epsilon over five' +is a positive number if + +epsilon is small, so why don't +we just pick the absolute + +value of 'x minus three' to be +less than 'epsilon over five?' + +In fact, that's what this delta +will be in that case. + +In other words, if the absolute +value of x minus + +three is within 'epsilon over +five', if 'x' is within + +'epsilon over five' of +three, notice what + +this product becomes. + +This is less than 'epsilon over +five', this we know from + +before is less than five, and +therefore, this product is + +less than epsilon. + +In other words, we have +exhibited the delta such that + +when this happens, the absolute +value of what we want + +to make less than +epsilon indeed + +becomes less than epsilon. + +Now because I recognize that +this is a hard topic, you'll + +notice in the reading +assignments that these + +problems are covered +in great detail. + +Everything that I've said in the +lesson so far is repeated + +in great computational depth +in our learning exercises. + +The point is that even if I +can make the epsilons and + +deltas seem a little bit more +meaningful for you than by the + +formal definition, notice that +it's simple only in comparison + +to what we had before. + +But it's still very, +very difficult. + +The beauty of Calculus is that +in many cases, we do not have + +to know what delta looks like +for a given epsilon. + +What we shall do there +therefore, in our next + +lecture, is to develop recipes +that will allow us to get the + +answers to these limit problems +without having to go + +through this genuinely difficult +problem of finding a + +given delta to match +a given epsilon. + +Though we must admit, in real +life, in many cases where + +you're making approximations, we +will want to know what the + +tolerance limits are. + +I am not belittling the epsilon +delta approach. + +All I'm saying is that in +certain problems, you do not + +need the epsilon delta approach +to get nice results, + +and that will be the topic +of our next lecture. + +So until next time, goodbye. + +GUEST SPEAKER: Funding for the +publication of this video was + +provided by the Gabriella and +Paul Rosenbaum Foundation. + +Help OCW continue to provide +free and open access to MIT + +courses by making a donation +at ocw.mit.edu/donate. \ No newline at end of file diff --git a/zY6Xf87GAyg.txt b/zY6Xf87GAyg.txt new file mode 100644 index 0000000000000000000000000000000000000000..9777f4d5581324b103dd60ac86eb448accd44be9 --- /dev/null +++ b/zY6Xf87GAyg.txt @@ -0,0 +1,6947 @@ +NARRATOR: The +following content is + +provided under a +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Welcome to +another exciting day + +of Engineering +Innovation and Design. + +We'll read some +interesting things today + +so the pace might be +a little bit faster. + +Here we go. + +Pop quiz. + +I've given you a +piece of paper there. + +If you don't have that paper +you can use your own paper. + +This is the pop quiz. + +It's going to be given orally. + +Are you ready? + +I want you to tell +me what questions I + +would ask you on +a pop quiz today. + +That is your pop quiz. + +Question. + +AUDIENCE: Could you +repeat that question? + +PROFESSOR: I'd be happy to. + +It sounds a bit circular, right? + +I want you to tell +me what you think + +I would ask you on +a pop quiz today + +if I were giving you +a quiz on the material + +that we've had so far. + +AUDIENCE: What are the 10 +steps in the design process. + +PROFESSOR: You should +just write this down. + +But I'm sure everyone would +appreciate your answer + +because it's a good one. + +So write that down. + +You might have two +or three answers. + +I'll give you about 34 +seconds to fill that out. + +And time. + +Take your papers. + +Pass them over to this side of +the room all the way that side. + +And pass them to the +top down once you've + +collected all those papers. + +Now-- and let's do it +quietly-- here's the question. + +What questions would I ask you? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Your name. + +That's a great one. + +Keep going. + +AUDIENCE: Do we write our names? + +PROFESSOR: Oh, yes. + +You should write your name +on your paper, of course. + +Yes. + +That's so I know who wrote this. + +But that would be a good +question to ask on a pop quiz-- + +your name. + +AUDIENCE: What is innovation. + +PROFESSOR: What is innovation. + +That's great. + +What else? + +AUDIENCE: A few characteristics +of good and bad design? + +PROFESSOR: A few +characteristics of? + +Of good and bad design. + +Sure. + +What else? + +AUDIENCE: I believe +I've already stated-- + +PROFESSOR: You did. + +And it was a great one. + +Could you restate it? + +AUDIENCE: What are the 10 +steps of the design process. + +PROFESSOR: The 10 +step design process. + +That's a wonderful one. + +Because that may even occur +on a subsequent pop quiz. + +AUDIENCE: What makes a +good design critique. + +PROFESSOR: What makes +a good design critique. + +Excellent. + +AUDIENCE: What's the most +important question to ask. + +PROFESSOR: What's the +most important question + +to ask particularly when +you're given a problem. + +Absolutely. + +That's a great one. + +Any other ones? + +You did a great job. + +You all get A's. + +So that's the beginning. + +So look for these +questions that may + +appear on subsequent +pop quizzes. + +Let's start in here. + +I want to know if anybody here +knows who these two people are. + +Anybody know who this +person is on the right? + +Tell me. + +Who is it? + +AUDIENCE: John Ive. + +PROFESSOR: Johnny Ive. + +Absolutely. + +And what does Johnny Ive do? + +AUDIENCE: He's the +Chief Designer at Apple. + +PROFESSOR: Yup. + +Chief Designer at Apple +for hardware products. + +AUDIENCE: Industrial Designer. + +PROFESSOR: Industrial Designer. + +Exactly. + +And on the left-- this guy +here in the black and white + +picture-- who's he? + +Hah. + +Not as famous as +Johnny Ive, I guess. + +Oh, maybe he is. + +Hold on. + +AUDIENCE: Is it Dieter Rams? + +PROFESSOR: It is Dieter Rams. + +Absolutely. + +Dieter Rams and Johnny Ive-- +two very important people. + +Let's show you a +little bit about them. + +Dieter Rams was born +in 1932 in Germany. + +And he's closely +associated with something + +called the functionalist +school of industrial design. + +He made these things. + +Johnny Ive was born +a lot later in 1967. + +And you're all +familiar with his work + +from having experienced it +firsthand or seen it firsthand. + +These are Dieter Rams' work. + +These are Johnny Ive's work. + +Let's do that again. + +This is what Dieter Rams made. + +And, interestingly enough, +Johnny Ives made these. + +Do you notice any parallels? + +Let's take a look some more. + +Johnny Ive on the right. + +Dieter Rams on the left. + +Johnny Ive on the right. + +Dieter Rams on the left. + +And would you believe Johnny +on the right and Dieter Rams + +on the left? + +Again, Johnny Ive on the +right with a speaker that + +has an iPod on top of it +and a speaker over here + +that has a phonograph on it. + +An iMac. + +A speaker. + +Johnny Ive. + +Dieter Rams. + +Johnny Ive on the right. + +It's like a television. + +Doesn't it look +like a television? + +And here it's a television. + +So this interesting. + +That's a speaker I guess. + +What is this product? + +AUDIENCE: An iPod. + +PROFESSOR: It is an iPod. + +And what is this product? + +AUDIENCE: A radio. + +PROFESSOR: It's a radio. + +It's a radio. + +So here's the question. + +They didn't talk about +this for a very long time-- + +Johnny Ive and Dieter Rams. + +So we're going to put +ourselves back up a few months + +or a few years ago when no +one knew what's going on here + +or how they felt +about each other. + +What do you think about this? + +What do you think about +this when you see this? + +AUDIENCE: Legally different. + +PROFESSOR: Legally different? + +Legally. + +What does that mean? + +AUDIENCE: It wouldn't be +copyright infringement. + +PROFESSOR: It's not +copyright infringement. + +Yeah, totally different. + +These look totally +different from each other. + +I know there's no +way you could see + +any similarity in this +corpus of work at all. + +Don't tell the Apple lawyers +who are suing Samsung-- + +or who sued Samsung +successfully. + +What else? + +What else do you think +of when you see this? + +Yes. + +AUDIENCE: Good +design is repeated. + +PROFESSOR: Good +design is repeated. + +What do you mean by repeated? + +AUDIENCE: Used again. + +PROFESSOR: That's pretty clever. + +Used again. + +[LAUGHTER] + +PROFESSOR: It's very-- + +[INTERPOSING VOICES] + +PROFESSOR: So she's +saying that good design, + +you just use the same +thing over again. + +AUDIENCE: No. + +PROFESSOR: No. + +Not quite? + +Am I shading it? + +OK. + +Let's see what-- go ahead. + +AUDIENCE: No, that's all. + +PROFESSOR: OK, fine. + +If you think of +something, let me know. + +AUDIENCE: As long +as you don't have + +to redesign the +wheel, [INAUDIBLE]? + +PROFESSOR: So adapting +designs for what you need, OK. + +What else? + +AUDIENCE: While the designs +are very similar and shared + +between them, the products +themselves are very different. + +PROFESSOR: Ah. + +He says the designs are similar +but the products are different. + +Tell me. + +I see a music player on +the left and a music player + +on the right. + +This one fits in your pocket. + +This one fits in your pocket. + +This one has a circular +thing that spins + +and this is a circular +thing that spins. + +This allows you to select stuff. + +That circle and this circle +allows you to select stuff. + +Tell me are they different? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: A little different. + +Sure. + +Because it's a screen +over here on the right. + +And a hard drive, yes. + +Actually it's kind of funny. + +Right now, interestingly, if you +buy an iPod Touch or something, + +you don't have to have +music on your iPod. + +It streams it wirelessly over +the air much like a radio. + +Fascinatingly similar. + +Everything old is new again. + +So you say they're different, +but they're kind of similar. + +What else? + +How do you think +they feel about this? + +How do you think +that Dieter Rams felt + +when he saw these +things coming out? + +AUDIENCE: Happy? + +PROFESSOR: Happy. + +Why happy? + +AUDIENCE: He insprired a whole +new generation of design. + +PROFESSOR: There we go. + +So he says, I'm so glad you're +copying all my hardware. + +I feel like I've really, +really contributed + +a lot more to society +because of this. + +That's one interpretation. + +What if someone was sitting +next to you during a test + +and took that philosophy? + +Would you feel happy about the +fact that they were inspiring + +a whole new set of A's? + +I don't know. + +At what point have you ever +made something or thought, hey, + +you're copying our stuff? + +AUDIENCE: You want to look at +whoever wrote the textbook. + +You're reading the textbook +and putting down the knowledge. + +You're stealing from them. + +PROFESSOR: I don't know. + +I don't know. + +This is interesting. + +So we have these things that +definitely seem very similar. + +But what's interesting +is that they both believe + +in the same +fundamental approaches + +to how to design great stuff. + +And they might have come +to similar conclusions + +either knowingly, because +of this form factor, + +maybe somewhat unknowingly +and they realized, + +boy this looks a +little bit like this, + +what can we learn from that. + +What is step number two? + +AUDIENCE: The information phase. + +PROFESSOR: The +information phase, yes. + +The information phase. + +So how can we leverage +what's out in the world + +already to inform our design? + +And they might have looked at-- +I don't know-- 50 or 100 or 200 + +different ideas and came on +this one or a group of them + +that looked like this. + +And he said, it reminds +me of this other thing + +that I saw a long time +ago, when I was a kid. + +And I loved the way it worked. + +So yes. + +I think you're +right about this-- + +that great design has +a lot of similarities. + +And you'll see this +happening throughout history. + +Things change very +little in history. + +There are few changes that +occur-- fundamental changes. + +Take a look at kitchens. + +Kitchens in the past-- I +don't know, let's say 60, + +70 years-- have only +had really two changes + +that are substantive. + +One of them is that there +are now-- almost always when + +the new kitchens are +designed-- open to another room + +or to an area where +people can entertain. + +People use the kitchen +differently now + +as a way of connecting +with people. + +Before, you'd shut +off the kitchen. + +You close the door. + +And you bring out the food. + +And you say, look at this +beautiful food and not the mess + +in the kitchen. + +That changed. + +And microwave ovens changed. + +Who here has a microwave oven? + +Wow. + +And who here has +a microwave oven + +and doesn't have +their own kitchen? + +So some of you don't +even have a kitchen + +and you've got a microwave oven. + +Pretty amazing. + +That's a big change. + +Otherwise, we've +got refrigeration. + +We've got a stove. + +About the same height as +all the stoves before it. + +We've got ovens. + +If you're rich, you +might have two ovens. + +Maybe you have a +garbage disposal now, + +but there's not a +whole bunch of changes. + +Things change very slowly. + +So we'll see this in design. + +And what's interesting is +that Dieter Rams came up + +with these 10 principles +of good design. + +So let's discuss them. + +I want you to tell me, for +each of these principles, + +what you think they mean and +if you think they're any good. + +Good design is innovative. + +What does that mean that +good design is innovative? + +How about this. + +Who thinks good design is +not innovative-- does not + +have to be innovative? + +Give me some example. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Sure. + +To prove that good design does +not have to be innovative. + +AUDIENCE: The one +you just showed us? + +PROFESSOR: So you're +saying that this was not + +an innovation over this? + +AUDIENCE: Well, parts of it. + +PROFESSOR: Part of it. + +What part? + +AUDIENCE: The way it looks. + +PROFESSOR: Is innovative? + +Or not innovate? + +AUDIENCE: Not if you're +comparing it to the other one. + +PROFESSOR: How come? + +This is made of plastic. + +This has different +kinds of plastic. + +It's got a screen on it. + +It's got four buttons +on the outside. + +It's got headphones that +are attached to it instead + +of using a speaker. + +You think it's too similar? + +AUDIENCE: No, I'm saying +that it's as innovative. + +I think it doesn't have +to be extremely innovative + +because I'm saying +they look very similar. + +There are innovations +but they're not drastic. + +PROFESSOR: Would you +say an iPod is not + +a drastic innovation +over a radio? + +AUDIENCE: Yes, I'm +saying it is, but I'm + +saying the physical +appearance of it. + +PROFESSOR: The +physical appearance + +may not be innovative. + +Other examples? + +I'm going to bring this +other slide back up. + +Yes. + +AUDIENCE: Some of +the things that we've + +been using since forever, +like a bowl or something-- + +it's really basic but I +think it's good design. + +PROFESSOR: A bowl +is a good design. + +But if someone made a new bowl-- + +AUDIENCE: It could +be a good design + +and innovate but I don't +think it's required. + +PROFESSOR: You +don't it's required? + +So a new bowl doesn't have to be +innovative to be well designed + +or to be a good design. + +That's interesting. + +AUDIENCE: To go back +to the last example, + +innovation also +depends on the context + +when you're looking +at the design. + +PROFESSOR: What do +you mean the context + +in looking at the design? + +What do you mean it +depends on the context? + +AUDIENCE: So right now, +before I saw Dieter Rams, + +I was of the opposite +position of Johnny Ives. + +But now I that I see a +different context, maybe I see + +[INAUDIBLE] + +PROFESSOR: Interesting. + +That's interesting. + +Context. + +What do you mean context, now? + +What's your context? + +AUDIENCE: It's what I know +about those kinds of designs. + +PROFESSOR: It's what you know. + +Context about what you know. + +Could it be something +else as well? + +AUDIENCE: Context +of similar designs + +and their past designs +related to that. + +PROFESSOR: A broader context. + +What else? + +Yes. + +AUDIENCE: I would have to argue +that this design is innovate + +because if a design is very +good, then there is no reason + +you want to improve it. + +PROFESSOR: If a design is +very good if there's no? + +AUDIENCE: There's no +reason to improve it. + +PROFESSOR: No reason +to improve it. + +AUDIENCE: If you come +up with something that's + +good than from +what is was before + +and it's selling +well then there's + +clearly some improvement. + +PROFESSOR: She said if +you have a new product + +and it's selling +well then there's + +clearly some improvement. + +What if it's not +selling so well? + +Could it be innovative? + +AUDIENCE: It could +also be innovative + +because I think the innovation +is defined-- well, not defined, + +but it about when you decide +that needs to be redesigned. + +PROFESSOR: Innovation +comes about when + +you decide it needs +to be redesigned. + +Interesting. + +Other ideas? + +I think context is +very interesting here + +and a little unusual. + +Context-- we look at the +world in a certain way. + +By a show of hands +here, who thinks + +that their hairstyle +looks ridiculous? + +There are no hands that went up. + +Who here thinks that people +whose-- they see pictures + +of people from the '80s +have ridiculous hairstyles? + +Yeah, a lot more +hands go up now. + +How about the '70s? + +So you don't think that in 20 +years you're going to look back + +at pictures of yourself and go, +I cannot believe my hair looked + +like that? + +Context, right? + +Context of our society. + +Angel goes, no way, +his hair looks great. + +That's awesome. + +I'm always keeping this thing. + +And he may. + +He may keep that. + +Some things are a little +more timeless than others. + +Do you know something +interesting about art forgery? + +Anyone know a lot +about art forgery? + +So if there's a piece of +art from the-- let's say, + +early 1800s-- and let's +suppose it's now 1920. + +And I have hired Jacob +to forge a piece of art-- + +he's a great art forger. + +Well, if he's great, at the time +when they had these forgeries, + +you wouldn't be able to +tell that it was a forgery. + +But 30, 40, 50 years later, you +say, oh, that's the forgery. + +I can tell. + +Because unconsciously, Jacob +sees the world around him + +and he begins to put in +elements of contemporary design + +into that piece. + +And 50 years later, the +context has changed, + +and you can see it. + +You can see the stuff in there. + +You can see those +differences and everything + +he's done to balance out +all the small differences. + +And it looks like a forgery. + +It's pretty amazing. + +So maybe this is true. + +Maybe it's not true. + +How about this one? + +Good design makes +a product useful. + +Is that true? + +Who thinks it's not true? + +Who thinks it is true? + +What does it mean? + +What does it mean to be useful? + +I want to know what +it means to be useful. + +AUDIENCE: Satifies a need. + +PROFESSOR: Satisfies a need. + +Tell me more about that. + +What's a need? + +Do I need to listen to all +my music wherever I am? + +I kind of need to. + +I get bored easily. + +Satisfies a need +or maybe something + +less serious than a need. + +AUDIENCE: If it adds value. + +PROFESSOR: Adds value. + +What does it mean to add value? + +What is value? + +Any ideas? + +Anyone? + +AUDIENCE: Performs an +action efficiently. + +PROFESSOR: Performs +an action efficiently. + +Does art perform an +action efficiently? + +AUDIENCE: It depends on +how if art is useful. + +PROFESSOR: Well, yes. + +Is art useful? + +I don't know. + +Is art design? + +Oh, different topic. + +Reserved for a different day. + +What else? + +AUDIENCE: It does what +it was designed to do. + +PROFESSOR: Designed to do. + +It does what it +was designed to do. + +So good design makes +a product useful + +because it's doing what +it's supposed to do. + +It has fulfilled its +intended purpose. + +AUDIENCE: I think I'd like +to argue that because I think + +that you could have a useful +product that has a purpose that + +wasn't intended by +the manufacturer. + +PROFESSOR: A useful +product whose purpose + +was not intended by +the manufacturer. + +Let's consider this. + +This is risky. + +This is a brand new Apple +Macintosh Retina Display + +MacBook Pro which I'm going +to use as a door stop. + +Oh, yeah. + +Not int-- + +[LAUGHTER] + +Can we get a close +up on that one? + +Can we see this over here? + +I don't know if you +can see it down here. + +This is my pride and joy here +being used as a door stop. + +Not intended by +the manufacturer. + +Pretty useful if we need +to prop open the door + +I suppose I could prop it open. + +Oh god, that scraping +sound sounds terrible. + +Anything for you guys. + +Anything. + +So look how nice it +props the door open + +if we didn't have +something else. + +Again, not intended +by the manufacturer + +who had to work on the +tolerances of this device. + +So that's interesting. + +What if it didn't performance +its intended action + +and I found a new use for it? + +Is it still useful? + +I could have an Acer or +something that I would think-- + +or maybe a five-year-old +Acer that's very, very slow + +and doesn't work very well and +I need to get rid of it anyway. + +And it's broke. + +It's falling apart. + +And the screen-- every time I +move it the screen falls off. + +And I can take it and make +it a very useful doorstep. + +Not its intended purpose at all. + +AUDIENCE: I still don't think +that it's a good design just + +because it has a use, though, +because you used it as a door + +stop but I still don't think +that is one of the best + +choices for a door stop. + +PROFESSOR: You don't think +it's the best choice for a door + +stop? + +I think it's a +beautiful door stop. + +Maybe the MacBook Air is better. + +It's wedge shaped. + +AUDIENCE: I think the +connotations of design + +is purposeful. + +So if you use it for +an unintended use, + +I don't think it's +considered a good thing. + +PROFESSOR: If I use it +for an unintended use, + +it's not good design. + +Why not? + +AUDIENCE: Because when +a designer is designing + +a product, they have a +specific use in mind. + +And they're trying +to achieve that goal. + +If they don't achieve that goal +and then achieve another goal-- + +PROFESSOR: What if they achieve +something far better, far more + +noble, far more incredible? + +AUDIENCE: That's not what +they were trying to do. + +PROFESSOR: I know but +is it good anyway? + +Does it matter what the +intent is is the question. + +AUDIENCE: I think it +does matter what the-- + +PROFESSOR: You think +intent matters. + +Who thinks intent matters? + +Who thinks intent +does not matter? + +Who's unsure about this? + +Oh, yes. + +This would be good for +a later conversation. + +Let's consider this. + +Good design-- now +know we're getting + +really crazy-- is aesthetic. + +What does it mean +to be aesthetic? + +[AUDIENCE MEMBERS RESPONDING + SIMULTANEOUSLY] + +PROFESSOR: Pleasing. + +Pleasing in what way? + +AUDIENCE: Visually. + +PROFESSOR: Visually pleasing. + +AUDIENCE: All ways. + +PROFESSOR: What? + +AUDIENCE: All ways, + +PROFESSOR: Pleasing +in other ways too. + +Not just visually but +auditorily pleasing. + +Maybe the smell of a new car. + +You don't think +they work on that? + +Oh, they work on that. + +In fact, Mercedes +once was having + +an issue with some cars +because it didn't quite + +have that Mercedes smell. + +So they hired a nose. + +Anyone knows what a nose is? + +It's a person who +smells really well. + +And it's about one +in-- I don't know-- + +100,000 people or 500,000 +people or a million people who + +have this great ability +to smell things well. + +And the nose went to the car. + +And they took this car. + +They shipped it from wherever +the car person, owner was. + +They gave her a different car. + +They shipped it down. + +And she [SNIFFING] smelled +all around the car. + +Then she went, door, +take the door off. + +And the went, OK. + +They stripped the door off. + +She's smelling around the door. + +She said take this +panel off the door. + +They took the +panel off the door. + +She's smelling and +goes, this is it. + +This is the problem +right here, in the door. + +It was the insulation. + +And they went to the +insulation people. + +They said, what did you +do to our insulation. + +They said, we didn't do +anything to the insulation. + +Show us what happened. + +And they found out. + +In one part of this process, +really early on, the insulation + +had been stored in sacks +that had once stored tea. + +Oh, yeah. + +That new car smell, +very important. + +So good design is aesthetic. + +Who thinks this is true that +good design must be aesthetic? + +AUDIENCE: It's something +that you're going to use + +and you want it to be pleasing +in every sense of the word. + +PROFESSOR: You want +it to be pleasing + +in every sense of the word? + +Who thinks it's not true? + +Tell us why. + +AUDIENCE: If you look at the +inside of a motor or something + +that people aren't going +to look at I feel like what + +it physically appears +like does not matter. + +PROFESSOR: Great. + +So you're saying if you look +at the inside of a motor people + +where people aren't +going to look, + +you think it doesn't matter? + +There's a company that +disagrees with this philosophy. + +And this company +is called Apple. + +I bring up a lot +of Apple examples + +because I happen to know them. + +And I think it's +very interesting + +because we are all +familiar with them. + +Apple does something +interesting. + +With the inside of an iPhone, if +you-- I'm not going to take it + +apart-- I'll do a lot. + +But if you take +the iPhone apart, + +everything there matches +a certain color chart + +that they have. + +They have a color chart. + +And if it doesn't +match the color chart + +it doesn't go inside +there because they believe + +if you start cheating +on the inside, + +it'll begin to leak out. + +And that cheating +will become revealed + +on the outside of the design. + +They think the parts that you +never see are still important. + +When the Macintosh +first came out-- + +it was a big object like this. + +A little small display. + +And if you were +able to open it-- + +and it was only +meant to be opened + +by professionals +who are in the shop. + +You weren't meant to open +it because of the CRT + +and it can be a very +high voltage there. + +You open it and +take it off the back + +and inside is a relief +of everyone's signature + +who worked on that +product, inside that, + +that no consumer +was meant to see. + +Do you still think +it's unimportant? + +AUDIENCE: I feel like what +makes a good design would + +be other factors. + +PROFESSOR: Other factors. + +OK. + +AUDIENCE: If you're talking +about like an engine + +or something would you count +the sound of it as aesthetic? + +PROFESSOR: I would count +the sound of an engine + +as aesthetic. + +Absolutely. + +AUDIENCE: So I want a car that +sounds like an angry weasel. + +[LAUGHTER] + +PROFESSOR: You want your +car to sound a certain way. + +People say, oh, the +roar of the car. + +The roar of that V8 +engine, they say. + +Or that distinctive Porsche +sound they talk about. + +Absolutely. + +Think of the sound of the car. + +Good design helps us to +understand a product. + +Who thinks this is true? + +Who thinks it's a lie? + +Who thinks it's not necessary? + +Good design helps to +understand a product, no? + +We all agree on this. + +What does it mean to +understand a product? + +How do I understand a +paper cup or a bowl? + +AUDIENCE: Well, there's +some cases in which you'll + +have something and +people don't usually + +read manuals or +anything like that. + +So the more intuitive +you can make the design-- + +like make some +spot for, no, this + +is clearly where your hand goes. + +PROFESSOR: Yes. + +Intuitive. + +Something where +it's clear, where + +you know how to interact +with it, engage with it. + +Good design is unobtrusive. + +What does it mean +to be unobtrusive? + +What do you mean about good +design being unobtrusive? + +AUDIENCE: Doesn't +get in the way? + +PROFESSOR: Doesn't +get in the way. + +Who thinks this is true? + +Who thinks this is not true? + +Can you give me an example? + +AUDIENCE: I think +there are buildings + +that are very well designed +and they're very obtrusive. + +PROFESSOR: Obtrusive +buildings that + +are well designed but obtrusive. + +What does it mean in that +context to be obtrusive? + +AUDIENCE: They can obstruct +traffic, other buildings, + +other-- + +PROFESSOR: They could +be obtrusive in terms + +of the visual line. + +Well some designs +are interesting. + +This design is somewhat +obtrusive, particularly + +when it's being used. + +If anyone here has ever +been in an environment + +where someone pulled +the fire alarm, + +you'll know how obtrusive +a fire alarm can be. + +But it's pretty good +because it needs + +to be at that time +and not now, which + +is why it's trying to be +a little bit more quiet. + +It could be even better maybe +if we didn't see it at all. + +Maybe. + +I'm not sure. + +There must be a reason why +they all have to be red. + +I don't know what +that reason is. + +AUDIENCE: I don't think +that premise applies + +when part of your design is +to make something obtrusive. + +PROFESSOR: When do you want +to make something obtrusive? + +Give me an example. + +AUDIENCE: When you +have a fire alarm. + +PROFESSOR: Well +we're trying to make + +it minimally obtrusive, right? + +They could've made it this big. + +It could be coming +out of the wall. + +It could go off every +hour just to let + +you know everything's cool. + +What if they made +it half the size? + +Or they could make +it even smaller. + +Wouldn't that be better? + +Maybe. + +OK. + +AUDIENCE: If you're Apple, yeah. + +PROFESSOR: Good +design is honest. + +Whoa. + +What does it mean to be +honest in your design? + +What does it mean to be honest? + +Good design is honest. + +AUDIENCE: If something +looks like it's + +supposed to be doing a specific +thing it shouldn't do something + +else. + +PROFESSOR: So something looks +like it should do something, + +it shouldn't be +doing something else. + +So I shouldn't walk up +to this and say, oh, you + +got a beautiful door stop. + +I've been looking for +a door stop all day. + +What else? + +AUDIENCE: If it promises +to do something, + +it should do that thing. + +PROFESSOR: It should do the +thing it promises to do. + +AUDIENCE: It should abide by +all regulations and safety + +conditions so it doesn't +hurt you in the process. + +PROFESSOR: Yes. + +It doesn't hurt you. + +It protects the user. + +AUDIENCE: Does that mean +you should design it + +in an honest way, as in not +steal the design from somebody? + +PROFESSOR: That's +a good question. + +Should you design it +in an honest ways, + +as in not steal the design? + +I don't know. + +We should ask Samsung. + +A little jab at that. + +It's a good question. + +AUDIENCE: I just don't know +what it's referring to. + +PROFESSOR: I don't either. + +I think we can actually find out +more information now about it. + +But it's a good question. + +What does it mean to be honest? + +It might mean that as well. + +It can mean a lot of things +about what its intended use is. + +When I use it, does +it do what it's + +supposed to do-- what +it promises to do? + +AUDIENCE: It can +also be adding more + +than it needs to be-- +like making a gold hammer. + +PROFESSOR: Gold hammer. + +So that gold toothbrush +that we saw from Napoleon. + +It may not be an honest design. + +Maybe it's silver. + +Silver toothbrush. + +Can we think of an example +where this is not true? + +Where design is dishonest? + +Where you believe you +could do something with it, + +but you can't and +it's still good? + +AUDIENCE: For instance, +there's iPhone cases + +that look like Game Boys. + +PROFESSOR: iPhone +cases that look + +like Game Boys that make +it not look like an iPhone. + +Is that dishonest? + +AUDIENCE: It might +be dishonest but I + +think it's still good design. + +PROFESSOR: What about up there? + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: Little outlets. + +You can't figure out how to get +this thing in til you turn it. + +Dishonest design. + +Who thinks that's +a dishonest design? + +Who thinks it's an +honest design anyway? + +Interesting. + +What about this one. + +What about childproof +bottle caps? + +It looks like they +could be opened, + +but if you are without the +skill, strength, or intellect, + +then you won't be +able to open this. + +Childproof bottle caps don't +just affect children though. + +They can affect adults who +simply don't have the strength + +to be able to open one of these +things-- to push down and open. + +So they have other designs +to get around that as well. + +But they're still a good design. + +But is that a bit dishonest? + +To give a whole population the +idea that it can be opened, + +but you can't open it? + +I'm not sure. + +Good design is durable. + +What does it mean to be durable? + +What does it actually +mean to be durable? + +For the design to be durable. + +AUDIENCE: It's not +going to break. + +It's last. + +PROFESSOR: An object that will +last a decent amount of time. + +AUDIENCE: I mean for the +design to be timeless. + +PROFESSOR: For the +design to be timeless. + +What do you mean by timeless? + +AUDIENCE: It means that +five years from now it + +won't look antiquated +and out of touch. + +PROFESSOR: So years from +now, is it will still + +look fresh and new and +novel contemporary. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: The idea that this +was the intended concept and it + +will still feel like +it's appropriate. + +AUDIENCE: I feel like it's +sort of difficult to do + +that though because-- + +PROFESSOR: Oh, yeah. + +Is it difficult? + +AUDIENCE: --people's ideas of +what they want change a lot. + +PROFESSOR: You say +that people's ideas + +of what they want change a lot. + +Tell us. + +AUDIENCE: Well, maybe not +a lot, but if you look back + +at older shows that were +predicting what the future was + +going to be like, they might +be spot on with the technology, + +but the aesthetics +of things-- we + +tend to have more rounded +corners on things. + +We don't like the +points as much anymore. + +Things like that, that people +hadn't even considered back + +then, are just taken for +granted now-- sort of. + +PROFESSOR: Interesting. + +AUDIENCE: Well, I +mean, good design + +can be determined +after the fact. + +Maybe when you +make it, you don't + +know if it's a good design. + +And then after +tastes change and you + +are 10 years down the road-- + +PROFESSOR: You're able +to see if it's still + +a good, sustainable, +relevant design later on. + +Interesting. + +Good design is consequent +to the last detail. + +Who thinks it's true? + +Who thinks it's false? + +Who is unsure? + +Who did not vote? + +Let's try it again. + +Given your options, good +design is-- Let's clarify + +what it means. + +My mistake here. + +What does it mean to be +consequent to the last detail? + +AUDIENCE: Everything you +put in the design has + +the intended effect. + +PROFESSOR: Everything +you put in the design has + +the intended effect. + +Everything. + +If you were going to give +me a written report-- + +a big one-- give me some +aspects of that report + +that you'd be concerned about. + +AUDIENCE: Whether or not +the content [INAUDIBLE] . + +PROFESSOR: Content. + +What else? + +AUDIENCE: Citations. + +PROFESSOR: Citations. + +What else? + +AUDIENCE: It's understandable. + +PROFESSOR: If it's +understandable. + +Comprehension. + +AUDIENCE: Format. + +PROFESSOR: Format. + +So the-- + +AUDIENCE: Structure. + +PROFESSOR: The structure. + +What else? + +AUDIENCE: I was going +to say the format. + +PROFESSOR: Format. + +What else? + +AUDIENCE: Font size. + +PROFESSOR: The font size. + +And therefore, what else? + +AUDIENCE: The font. + +PROFESSOR: The font. + +Absolutely. + +What else? + +AUDIENCE: Is it too wordy? + +PROFESSOR: Length of words. + +AUDIENCE: The paper +it's on itself. + +PROFESSOR: The paper +it's on itself. + +Absolutely. + +What else then? + +AUDIENCE: Does it fulfil +the task and requirements? + +PROFESSOR: Does it fill +the task and requirements? + +We talked about the paper. + +I heard something else here. + +AUDIENCE: Color of the ink. + +PROFESSOR: Color the ink. + +Absolutely. + +Color of the ink. + +AUDIENCE: When you present the +paper-- like if it's bound. + +PROFESSOR: Yes. + +If it's bound. + +If it's stapled. + +How it's bound. + +All these things are details. + +Do you think they all matter? + +AUDIENCE: Yes. + +PROFESSOR: Who thinks +if you take a paper that + +has brilliant +content and a paper + +with the exact +same content-- two + +of them with the same +content-- and one + +is stapled in the corner and +one is bound beautifully-- + +do you think that they will +affect your grade at all? + +Who thinks it will +not affect your grade? + +Who thinks it will +affect your grade? + +That's good. + +Statistics show that it +will affect your grade. + +Everyone who doesn't think that +it doesn't affect your grade, + +you should make sure that +your papers are well bound-- + +because it looks to someone +else like you put more work + +and effort into it +and that you believe + +more sincerely in your product. + +AUDIENCE: A lot of that depends +on what the value system is + +that you're working on. + +If you don't actually +have the money + +or you don't want to spend +the money to bind that paper + +and you think that it's good +enough on its own then maybe + +the best design +isn't binding it. + +You might have a professor +who doesn't care. + +Given it's on average you +will score higher [INAUDIBLE]. + +PROFESSOR: So yes. + +You have a specific case +where it doesn't matter. + +That's true. + +AUDIENCE: I think you're talking +about high school teachers-- + +that probably doesn't apply-- +but once you start going + +into college and you're +looking at the true content + +of the paper-- + +PROFESSOR: You think it +applies in high school + +but not in college. + +AUDIENCE: I think it +applies less in college + +than it does in high school. + +PROFESSOR: I will tell +you this is not true. + +I will tell you from firsthand. + +And when I get a paper-- +and I know this to be true-- + +if anyone submits +their midterm report-- + +their individual project-- +and it is stapled + +in the upper left hand corner, +you will with 100% certainly + +be dropping the class +soon afterwards. + +I've seen it every +single semester. + +Every semester, I'll get +at least one person-- + +and I'll say, please +do not do that-- + +and they will give it to +me anyway bound like that. + +And I just suddenly +have to count to 10 + +before they drop the class. + +AUDIENCE: But do you ask +them not to staple it? + +PROFESSOR: I say, +please don't use + +a staple in the upper +left hand corner. + +And they do it anyway. + +There's a high +correlation between this. + +And teachers, when you get +that beautifully bound thing, + +you think, wow, look +how cool this is. + +If you could sit in +those rooms, you'll + +think there is a difference. + +And of course, they will +read the content as well. + +It's not that it's going +to make up for bad content. + +But it shows a lot more +strength and structure. + +And their brain will start +focusing a little bit + +differently when they +review that paper. + +Consequently to the last detail. + +Who thinks that good design is +consequent to the last detail? + +Who thinks it is not? + +Why not? + +AUDIENCE: Well, I mean, +it's the same thing. + +It's just like, you +have to consider + +what the audience will do. + +You need to knowledge the +value of that extra detail. + +If they don't value +it, like if you're just + +trying to feed a lot of people +and they're just incredibly + +hungry-- if you are trying to +feed a starving population, + +they're not going to +care that you seasoned + +the food that you've +made exactly perfectly. + +They're going to care once +they get something to eat + +and they get more of it. + +PROFESSOR: What if you +could season it perfectly? + +Would that be better design? + +AUDIENCE: Well, +that would be great, + +but that's not the +world we live in. + +We live in a world +with limitations + +PROFESSOR: Yes. + +We do live with limitations. + +But the question I would +ask you to think about + +is when are those +limitations real + +and when do we impose them +on ourselves unnecessarily? + +When do we think, well, we can't +do this, instead of thinking, + +well, maybe we can't do this-- +let's see if we can do it. + +You'll find a tremendous +amount of innovation + +happens when we resolve +the tension between what? + +From last class. + +AUDIENCE: From what we desire? + +PROFESSOR: Yeah. + +From what we desire +and what we require. + +If we can resolve +these tensions, + +that is where we get innovation. + +Absolutely. + +Good design is concerned +with the environment. + +What does it mean? + +AUDIENCE: Good design +doesn't neglect anything. + +PROFESSOR: Yes. + +Good design isn't just sitting +in its own little vacuum. + +It works within a whole +system, a whole big context + +of things, whether it's +a physical environment, + +a social environment, +or, like the iPod player, + +works with the +iTunes Music Store. + +It connects to other things. + +Lastly, good design is as +little design as possible. + +What does that mean? + +AUDIENCE: I think +to use other things, + +like how Apple used +previous designs. + +So maybe they didn't have +to redesign that much. + +PROFESSOR: So she's +saying less design. + +Not as much redesign. + +What other interpretations +do we have? + +AUDIENCE: Keep it simple. + +PROFESSOR: To keep it simple. + +What else? + +AUDIENCE: Going back to +the example of Apple, + +they try to limit the number +of buttons that you have. + +PROFESSOR: Try and +limit our buttons. + +Yes. + +AUDIENCE: And also +with the mouse. + +Let's use the Magic +Mouse for example. + +There is no button like +there are with other mice. + +There aren't two buttons. + +It's just one +click that you use. + +And it's very intuitive to +how you're going to use it. + +PROFESSOR: So a Magic Mouse +has no buttons on it at all + +and you can still click anyway. + +And it knows what you're doing. + +They're just trying to +reduce that user experience. + +But they had a lot +more complexity inside + +to figure out how +to make that work. + +What else? + +AUDIENCE: I think the +design is as little design + +as possible as in off +of previous designs, + +like going back to Dieter Rams. + +PROFESSOR: Dieter Rams' work. + +Absolutely. + +Where he's really trying +to get that functionalist-- + +let's think about the functions +first and really build things + +around in the simplest most +streamlined, elegant way + +possible. + +I want to consider these steps. + +Part of your homework will be to +consider if these are all true + +and reflect on them and see +how they can be improved + +and which ones are missing. + +I bet you're going to be able to +think of ones that are missing. + +Design challenge. + +Are you ready? + +Are you ready? + +AUDIENCE: Yes. + +PROFESSOR: I'll take that. + +Here we go. + +Are you ready? + +This is what you know. + +The music stops. + +A man is dead. + +That's all you know. + +You need to solve what +happened and why did it happen. + +And I will answer questions. + +I will say, yes. + +Or I will say, no. + +Or I will say, Relevant. + +That's what you get. + +And we need to do this quickly. + +Go. + +AUDIENCE: Was the man +listening to the music? + +PROFESSOR: Yes. + +AUDIENCE: Was he blindfolded? + +PROFESSOR: Yes. + +If you happen to know +this particular question. + +Was he blindfolded? + +Yes. + +AUDIENCE: Did he die +because the music stopped? + +PROFESSOR: Did he die +because the music stopped? + +No. + +AUDIENCE: Is this a human +man who actually died and was + +living and then now +is no longer living? + +PROFESSOR: Was it a human +man who died who was living + +and is no longer living. + +Yes. + +AUDIENCE: Did the music +give instructions? + +PROFESSOR: Did the +music give instructions? + +No. + +AUDIENCE: Did he die while +the music was playing? + +PROFESSOR: Did he die while +the music was playing? + +No. + +AUDIENCE: Where'd this happen? + +PROFESSOR: Where +did this happen? + +AUDIENCE MEMBER 1: +Yes or no questions. + +AUDIENCE MEMBER 2: +Does the music stopping + +coincide with the man's death? + +PROFESSOR: The music stopped and +coincided with the man's death. + +What's the question? + +AUDIENCE: Did the music +coincide with the man's death? + +PROFESSOR: I don't know +how to answer that one. + +Give me some more detail +around the question. + +AUDIENCE: Did they +happen at the same time? + +PROFESSOR: No. + +Did they happen +at the same time? + +No. + +AUDIENCE: Was he alone? + +PROFESSOR: Was he alone? + +No. + +AUDIENCE: Did the +music stopping indicate + +something else is starting? + +PROFESSOR: Did the +music stopping indicate + +something else is starting? + +Yes. + +AUDIENCE: Was the music +playing in headphones? + +PROFESSOR: Was the music +playing in headphones? + +No. + +AUDIENCE: Did the music +start in relation to + +that the man was dead? + +PROFESSOR: Did the music? + +AUDIENCE: Did the music +start in relation to the fact + +that the man was dead? + +PROFESSOR: Did the music start +because the man was dead? + +No. + +The music stops. + +The man is dead. + +AUDIENCE: Did someone +stop the music? + +PROFESSOR: Did someone +stop the music? + +Irrelevant. + +AUDIENCE: Did +someone kill the man? + +PROFESSOR: Did +someone kill the man? + +No. + +AUDIENCE: Did the man have +a preexisting condition? + +PROFESSOR: Do the man have +a preexisting condition + +that was not covered +under the health code? + +No. + +He did not have a +preexisting condition. + +AUDIENCE: Is the music +playing at a funeral? + +PROFESSOR: Is the music +playing at a funeral? + +No. + +AUDIENCE: Did the music stop +because it ended or did it + +stop [INAUDIBLE]. + +PROFESSOR: I can't +answer that question + +with a yes, a no, or irrelevant. + +AUDIENCE: Was the music short? + +PROFESSOR: Was the +music to cut short? + +No. + +AUDIENCE: Was the man's +death an accident? + +PROFESSOR: Was the +man's death an accident? + +Yes. + +AUDIENCE: Did the man die +before the music started? + +PROFESSOR: Did the men die +before the music started? + +No. + +AUDIENCE: Did the man die +because the music stopped? + +PROFESSOR: Did the man die +because the music stopped? + +No. + +AUDIENCE: Is the reason +the man died also + +the reason that +the music stopped? + +PROFESSOR: Is the reason +that the man died also + +the reason that +the music stopped? + +No. + +AUDIENCE: Did the +man kill himself? + +PROFESSOR: Did the +man kill himself? + +Ask the question differently. + +AUDIENCE: Is the man +responsible for his own death? + +PROFESSOR: Is the man +responsible for his own death? + +Yes. + +AUDIENCE: Was the man involved +in stopping the music? + +PROFESSOR: Was the man +involved in stopping the music? + +No. + +AUDIENCE: Did the man die +before the music stopped? + +PROFESSOR: No. + +He did not die before +the music stopped? + +AUDIENCE: Was he in public? + +PROFESSOR: Was he in public? + +Yes. + +AUDIENCE: Was he driving? + +PROFESSOR: Was a driving? + +No. + +AUDIENCE: Is the music +the name of something + +unrelated to sound? + +PROFESSOR: Is the music +the name of something + +unrelated to sound? + +I don't know what you mean. + +But I want to. + +AUDIENCE: Is the music a name? + +PROFESSOR: Is the music a? + +AUDIENCE: A name. + +PROFESSOR: A name. + +AUDIENCE: Of something. + +PROFESSOR: Of something. + +I don't know what that means. + +AUDIENCE MEMBER 1: +Is it not music? + +AUDIENCE MEMBER 2: He +means is there a track + +called "The Music." + +PROFESSOR: Oh. + +No. + +Thank you. + +It's hard. + +It's not that hard. + +AUDIENCE: Was the man +in control of the music? + +PROFESSOR: Was the man +in control of the music? + +No. + +AUDIENCE: Is the music relevant +to the man's death at all? + +PROFESSOR: Is the music relevant +at all to the man's death? + +Yes. + +AUDIENCE: Did someone +try to stop his death? + +PROFESSOR: Did someone +try to stop his death? + +Irrelevant. + +AUDIENCE: Did he want to die? + +PROFESSOR: Did the +man want to die? + +No. + +AUDIENCE: Is the +song that was playing + +relevant to the man's death? + +PROFESSOR: Is the +song that was playing + +relevant to the man's death? + +-ish. + +Sorry to break the format. + +AUDIENCE: So is it an internal +injury that killed him? + +An external injury +would be like a trauma, + +whereas an internal injury +would be like a heart attack. + +I'm trying to figure +out the way he died. + +PROFESSOR: Ask me a +very specific question. + +AUDIENCE: Was it +an internal injury? + +[LAUGHTER] + +Did he die of a heart attack? + +PROFESSOR: No. + +AUDIENCE MEMBER 1: A stroke? + +AUDIENCE MEMBER 2: +Something hit him? + +PROFESSOR: Yes. + +AUDIENCE: An ice +cream truck hit him. + +PROFESSOR: No. + +Did something hit him? + +Yes. + +Did an ice cream truck hit him? + +No. + +But that's very funny. + +AUDIENCE: Was the thing that +hit him intended to hit him? + +PROFESSOR: Was the thing that +hit him intended to hit him? + +No. + +AUDIENCE: Did the music +player fall on the guy? + +PROFESSOR: The music player +did not fall on the guy. + +AUDIENCE: Since he +was blindfolded, + +was he to guide himself +in a certain direction? + +PROFESSOR: Ask the +question again. + +AUDIENCE: Since he +was blindfolded, + +was he using the music +as a way to guide himself + +towards or away from something? + +PROFESSOR: Yes. + +She asked the question was +the music guiding him-- + +AUDIENCE: Was he using +the music to guide him-- + +PROFESSOR: Was he using +the music to guide him? + +Yes. + +AUDIENCE: Is the man a +performer of some sort? + +PROFESSOR: Is the +man a performer? + +Yes. + +AUDIENCE: Was he a +tightrope walker? + +PROFESSOR: Was he +a tightrope walker? + +Yes. + +AUDIENCE: Did he fall? + +PROFESSOR: Did he fall? + +Yes. + +AUDIENCE: Was the +man using the music + +to guide himself blindfolded +across the tightrope + +and then the music +stopped and he fell off? + +PROFESSOR: Was the man +using the music to guide him + +across the tightrope-- + +AUDIENCE: While he +was blindfolded. + +PROFESSOR: --while +he was blindfolded. + +And what was the next part? + +AUDIENCE: The music +stopped so he couldn't + +find where he was going +so then he fell off. + +PROFESSOR: The +music stopped so he + +couldn't find +where he was going. + +And therefore, he fall off. + +No. + +So close. + +AUDIENCE: Was he supposed to +jump into a net and missed? + +PROFESSOR: We he supposed to +jump into a net and missed? + +No. + +AUDIENCE: Did the +speakers fall on him? + +PROFESSOR: Did the +speakers fall on him? + +No. + +AUDIENCE: Was he +using the number + +of beats to traverse +the tightrope? + +PROFESSOR: Was using +the number of beats + +to traverse the tightrope? + +No. + +AUDIENCE: Was the tightrope +the wire for the music player? + +PROFESSOR: Was the tightrope +the wire for the music player? + +Very creative. + +No. + +AUDIENCE: Was the music supposed +to stop when he was at the end + +but it stopped early? + +PROFESSOR: Was +the music supposed + +to be stopped when +he got to the end? + +Yes. + +And that's what happened. + +So he's walking on a tightrope. + +And all of a sudden-- +he's blindfolded-- + +and the music stops, so he +figures he's at the end. + +And he just steps off. + +But he wasn't at the end. + +And there was no net. + +And he fell to his death +where the ground hit him. + +[AUDIENCE DISGRUNTLEMENT] + +You said, did something hit him. + +Yes. + +Something hit him. + +I didn't lie. + +Something did hit him. + +AUDIENCE: He hit the ground. + +PROFESSOR: Oh. + +I'm sorry. + +You've all taken physics. + +The ground hit him as +much as he hit the ground. + +[INTERPOSING VOICES] + +PROFESSOR: He wasn't dead. + +He was still alive. + +[INTERPOSING VOICES] + +PROFESSOR: The music +stopped before he died. + +AUDIENCE: Because arguably, he +died when he hit the concrete. + +PROFESSOR: Oh. + +No. + +I answered the questions +very specifically each time. + +In fact, we have all +the questions, here, + +that you asked. + +Any ones in particular +that were of note? + +So what's very interesting +here is about asking questions. + +And it leads us +into what we want + +to talk about here +with research. + +Asking good questions +is really hard. + +And when you ask +questions, sometimes you + +find you're going down a path +that's giving you information. + +Sometimes you don't. + +Often the first question I +get asked was, was he outside? + +No. + +Was he in a building. + +Yes. + +What comes to your +mind as someone + +said he was in a building? + +[INTERPOSING VOICES] + +PROFESSOR: You'd think +an office building. + +Right? + +You wouldn't think +a tent or a circus. + +That's a building. + +It's a structure. + +If I said no to building, would +I have to say yes to tent? + +Like at some point if +I'm being very binary. + +So asking questions +is very hard. + +You see any ones +that you're skimming? + +QUESTION TYPER: The internal +injury one was really good. + +PROFESSOR: Internal injuries. + +QUESTION TYPER: That put +them in the right direction. + +PROFESSOR: Hitting the ground. + +So when you said, did +something hit him-- well, + +yes, something hit him. + +But it doesn't tell you +about the direction. + +Right? + +And now you're +beginning to think + +an ice cream truck struck him. + +And this makes sense. + +What you did is exactly right. + +All this is exactly what you +should be thinking about. + +But it shows us, given some +data-- think about when you're + +asking questions-- you can +get the exact, truthful, right + +answer and still be radically +incorrect about what + +you understand from this. + +That was a little +induction to research + +here, complete with formula. + +So research. + +Just a basic thing. + +You want to ask questions +and find out about stuff. + +Asking questions is important, +but answers can be misleading. + +Academic and scientific +research is often wrong. + +We think it's the +truth when we read it. + +And maybe it's truthful. + +Many of them are very good. + +But often they're wrong. + +And we base beliefs and make +conclusions and decisions + +based on faulty information. + +Which gets us back +to the first thing + +I talked to you about on +the first day, which was? + +To do what? + +The first thing. + +AUDIENCE: Ask the +right question. + +PROFESSOR: To ask why. + +To make sure that we're getting +to the underlying reasons. + +Because that may be wrong. + +Research results may be good but +the conclusions may be wrong. + +So here we had great research. + +The question was, did he +die of internal injuries. + +Yes. + +Did something hit him? + +Yes. + +What did we conclude? + +That something hit him-- +that he was stationary. + +Easy to do. + +This is Fitts' Law. + +It's pretty cool. + +I won't bother +explaining it right now. + +It's so interesting. + +It's used a lot in computer +and human interaction. + +I'll give you the basic idea. + +This distance is D. And I +think, here in the formula, + +this is W, which really +talks about-- actually, + +that's Ws here and Ws here. + +It's a margin of +error, technically. + +But here it's a width. + +And what he would do +is he'd say, look, + +we can have people doing +something like tapping. + +Here. + +Here. + +As fast as you can. + +Now if I take those +lines and I change them. + +I'm going to make +them like this. + +So that's one. + +I do this. + +Faster. + +What if I do this? + +Pretty good. + +Pretty good. + +And so I'm pretty +good with that. + +But my speed changed. + +And if I wanted to go faster, +my accuracy would go down. + +So what can we +conclude from this? + +Lots of things. + +Somethings that are very +good and somethings that + +are incorrect. + +One conclusion. + +If I work on a computer +system that just + +has a keyboard and +no mice at all. + +And it's now 1985, 1986. + +Should I use a graphical +user interface or not? + +Well the incorrect conclusion +might be it will slow you down. + +Because every time you +move your hand over-- we + +can calculate it out. + +How long it's going to +take you for every action + +that requires you +to use a mouse. + +And so we don't want to +have people slowing down. + +We're going to keep everything +using keyboard commands. + +But it may not be true that +it's going to make you faster. + +That's an incorrect conclusion-- +maybe given that same system. + +But maybe if you +redesign the system, + +it will actually become +a system that you + +can use faster because +you can use the mouse + +to be able to do things +you couldn't do before. + +And the correct +conclusion that we draw + +is the right click +for a pop-up menu-- + +you right click on something +and then the menu's right there. + +So now you've moved +your hand to the mouse. + +You move your mouse +to the target. + +And you right click on it. + +And now you have a +menu that's contextual, + +that's short and easy to get to. + +Instead of moving your +mouse all the way to the top + +to a big menu bar and having to +find your way through cascading + +menus. + +That is the correct use of it. + +Research results may be good +but conclusions may be wrong. + +So when you see a really good +research piece like this, + +understand that what you do +with that is really important. + +We design projects for people. + +People don't know +what they want often. + +I could say, do you want +to have a device that's + +this big and flat and has a +keyboard on it that's virtual + +and all the stuff. + +You might say, nah, +I don't want that. + +In fact, when the iPad +came out, the week + +beforehand or two weeks +before I had pre-ordered it + +because I had to be +really cool and wanted it. + +And my classmates were +saying, oh that's ridiculous. + +I said, why is it ridiculous? + +Well, it's like a bigger +iPhone and you don't need that. + +And I'm like I think +it's different. + +They said, no, it's +just a bigger iPhone. + +We're not going to get one. + +Well within a month, of +course, a whole bunch of them + +are ordering them because +they saw it was different. + +But if you asked them-- +if you said, would you + +like to pay $600 or $800 +for an object like this, + +they might have said, no. + +And then they never +would've made an iPad. + +It's very hard to ask +people what they want. + +And if they know what they want, +they often can't articulate it. + +They don't know what words +to use to convey the idea. + +So as a designer +when you research, + +how you ask questions, how +you interpret people's answers + +is really critical. + +I'd like to show you +this video about why + +it can be hard to +get good answers when + +you ask a question. + +This video is for a game +show called the Family Feud. + +Who does not know the show? + +Briefly, here's how it works. + +They have parts +of the show where + +they ask people-- 100 people +get surveyed-- they'll ask them + +a question like, +what would you expect + +to find in a refrigerator? + +And you want to guess +the most popular answer + +because that will be the +number of points you get. + +So what would you answer? + +AUDIENCE: Milk. + +PROFESSOR: Milk. + +Milk is the most popular answer. + +And so this is a speed +round at the end where + +they have two different teams. + +And this one person comes +over and he's looking away + +from the board and this guy asks +him these questions in a row. + +It's like five questions. + +One of them is +the milk question. + +You're asking this person +who's on a game show-- average + +person, answering questions. + +He happens to be under pressure +because he's on a game show. + +You'll see his responses. + +I'm just going to roll +this for a little bit + +and then we're going to show +you the second part of this. + +HOST (ON SCREEN): Name an animal +with three letters in its name. + +CONTESTANT 1 (ON SCREEN): Frog. + +HOST (ON SCREEN): Something +found in a refrigerator. + +CONTESTANT 1 (ON SCREEN): Milk. + +HOST (ON SCREEN): A +brand of gasoline. + +CONTESTANT 1 (ON +SCREEN): Regular. + +HOST (ON SCREEN): Something +that comes with a summer storm. + +CONTESTANT 1 (ON SCREEN): Snow. + +HOST (ON SCREEN): A sport +with an all-star game. + +[BUZZER] + +Turn around. + +You may never be up here again. + +Let's take a look. + +Name an animal with three +letters in its name. + +You said, frog. + +Our survey said 0. + +Two people would +have to say that. + +Something found +in a refrigerator. + +You said, milk. + +Our survey said 28. + +A brand of gasoline we wanted. + +You said, regular. + +That's a good brand. + +Our survey said. + +CONTESTANT 1 (ON SCREEN): +It's the brand I use. + +HOST (ON SCREEN): Something +that comes with a summer storm. + +You gave me the answer snow. + +Our survey said. + +PROFESSOR: So you saw +what happened here. + +This person is trying to answer +questions under pressure. + +He's trying to provide +the best answers he can. + +An animal with three letters. + +Frog. + +I can see maybe-- it's +a short word, right? + +Something in the refrigerator. + +We got milk. + +You all got milk. + +You were great. + +A brand of gasoline. + +Regular. + +He thought regular +is the brand instead + +of Shell or Mobil +or something else. + +That's what he associated +with that area. + +Something that comes +with a summer storm. + +Snow. + +It doesn't happen +in the summer, I + +think, for most +parts of the world. + +Certainly not here. + +But his reaction was to supply +an answer that wasn't useful, + +even though he probably +would know things. + +But under pressure, +not easy for him + +to be able to come +up with good answers. + +Let's continue this +and watch his opponent. + +HOST (ON SCREEN): I got +good news and bad news. + +CONTESTANT 2 (ON SCREEN): +Give me the bad news first. + +HOST (ON SCREEN): +The bad news is + +you need 172 points +to win the money. + +The good news is you're +the man to do it. + +I'm going to ask you +the same questions + +I asked the other Bob. + +You cannot and you do not +want to duplicate his answers. + +If you do, you hear this. + +[BUZZER] + +What noise do we hear? + +[BUZZER] + +Thank you. + +I will then say try again. + +You'll give me another answer. + +Alright? + +Remind everyone, to +Bob's shame, the answers + +he gave us and give me 20 +seconds on the clock, please. + +Name an animal with three +letters in its name. + +CONTESTANT 2 (ON +SCREEN): Alligator. + +HOST (ON SCREEN): Something +found in a refrigerator. + +CONTESTANT 2 (ON SCREEN): Milk. + +HOST (ON SCREEN): Try again. + +CONTESTANT 2 (ON SCREEN): Ice. + +HOST (ON SCREEN): A +brand of gasoline. + +CONTESTANT 2 (ON SCREEN): Ethyl. + +HOST (ON SCREEN): Something +that comes with a summer storm. + +CONTESTANT 2 (ON SCREEN): Rain. + +HOST (ON SCREEN): A sport +with an all-star game. + +[BUZZER] + +CONTESTANT 2 (ON +SCREEN): Football. + +HOST (ON SCREEN): Football. + +You've got to give him that. + +Any man that says alligator, +you've got to give it. + +Name an animal with three +letters in its name. + +You said, alligator. + +Our survey said. + +You don't use narcotics. + +Do you? + +CONTESTANT 2 (ON +SCREEN): No, but I will. + +HOST (ON SCREEN): I mean, +I thought frog was bad. + +I thought frog was +a disastrous answer + +until you came up +with alligator. + +It's a real tough one. + +Dog was the number one answer. + +Dog. + +CONTESTANT 2 (ON SCREEN): +Are you sure it was? + +HOST (ON SCREEN): Three +letters in it's name. + +Dog. + +D-O-G. + +[CHATTERING] + +HOST (ON SCREEN): And +we wanted something + +found in a refrigerator. + +You both had this +nailed down very well. + +Unfortunately, you repeated +his answer, which was milk. + +But you said, ice. + +That's the place to find it. + +Our survey said 17. + +Milk was the number one answer. + +It was the only good +thing that Bob did. + +A brand of gasoline we asked. + +You said, ethyl. + +CONTESTANT 2 (ON +SCREEN): A brand. + +HOST (ON SCREEN): A brand which +I think you've been drinking. + +Our survey said. + +The number one answer was Shell. + +CONTESTANT 2 (ON SCREEN): Shell. + +HOST (ON SCREEN): Something +that comes with a summer storm. + +At least you have reached. + +Did you see his answer? + +Snow! + +At least you said, +I believe, rain. + +Is that correct? + +Well, that's good. + +Our survey said 9. + +And then a sport with +an all-star game. + +You said, Football. + +It was about two minutes late +but I insisted you get it. + +Our survey said. + +[BUZZER] + +So these people are not stupid. + +They're smart people. + +They're regular people. + +And they come with these +answers under pressure + +which were just not the +right answers by a long shot. + +So how you ask questions, +who you ask questions to, + +the environment +you ask questions-- + +it may not always +be this extreme + +where someone says alligator +for a three letter animal. + +But you will get shades +of differences-- shades + +of meaning. + +Sometime who is +very stressed will + +provide really bad answers. + +If you're really, really-- +I get test anxiety. + +So when I took my +tests in grad school + +I went to support services +and got time and a half + +because I couldn't do it. + +I'd be there and I would +look at these problems + +and the information would +empty out of my mind. + +I just was too anxious to do it. + +Like other people, you will +get different responses. + +So how you conduct your +research is really important. + +So one of the various +ways we can research. + +Let's talk about this. + +If it was 1960, and +we wanted to learn + +to cook like a French +chef, what would we do? + +What could we do? + +AUDIENCE: Go to France. + +PROFESSOR: Go to France? + +Just go to France? + +And you just happened +to have the knowledge + +by going to France. + +Yeah. if you start +smoking, you get-- + +[GRUMBLES] + +You walk down the street, and +you just happened to know. + +No. + +What else do you do? + +AUDIENCE: Talk to +the chefs there. + +PROFESSOR: Talks +to the Chefs there. + +Sure. + +What else could you do? + +AUDIENCE: What about +French cooking school? + +PROFESSOR: Go to +French cooking school. + +AUDIENCE: Watch Julia Child. + +PROFESSOR: Watch Julia Child. + +Absolutely. + +Watch her show called +The French Chef. + +Yes. + +This is good. + +1848. + +The best way to conduct a +defensive military retaliation. + +AUDIENCE: Go to military school. + +PROFESSOR: Military school. + +Yes. + +Look at the what's +happened before in history. + +1990s. + +The best way to clean a kitchen. + +We want to make the best way to +clean the kitchens in the '90s. + +What do we do? + +AUDIENCE: Ask your mom. + +PROFESSOR: Ask your mom. + +If not, just ask your +mom, however, you + +could also do what? + +AUDIENCE: Watch her. + +PROFESSOR: Watch her. + +Yes. + +2013. + +You want to save money +on a call center. + +This call center +handles technical issues + +for customer complaints +for satellite television. + +What can you do? + +AUDIENCE: Internet. + +PROFESSOR: What would +you do with the internet? + +AUDIENCE: Just search for it. + +PROFESSOR: Search for what +has been done to save money + +in call centers that +have these issues? + +I don't think +you're going to get + +a whole lot of good responses. + +AUDIENCE: Outsource. + +PROFESSOR: Outsource what? + +AUDIENCE: The people answering-- + +PROFESSOR: How would +you learn though? + +How would you research this? + +Have a consulting economy. + +What would they do? + +AUDIENCE: They would +go out and probably + +talk to other people who have +done similar things in order + +to--? + +PROFESSOR: Yes. + +They could talk to other people +who had similar problems, + +but what about this +one particular call + +center for satellite +TV, located in Denver? + +AUDIENCE: Look at its budget. + +PROFESSOR: Look it's budget. + +What would you learn +from the budget? + +AUDIENCE: Seeing where +the most money is going? + +PROFESSOR: Well, we +know that a lot of money + +is going to this thing. + +How do we have them save money +on this one particular part + +of the call center? + +AUDIENCE: Reduce the +number of workers + +by having an automatic system. + +PROFESSOR: Reduce +the number of workers + +by having an automatic +system, but how would you + +know what the automatic +system should be doing? + +AUDIENCE: Look at +what the workers do. + +PROFESSOR: Look at +what the workers do. + +By what method? + +AUDIENCE: Watch them. + +PROFESSOR: Watch them. + +Absolutely. + +Actually sit down there +and watch the workers. + +2015. + +The decision to develop an +extremely new type of consumer + +product, like when people had +to develop the iPad before they + +developed the iPad. + +What would you do? + +AUDIENCE: Talk to people. + +PROFESSOR: Talk to people +and ask them what they want? + +What would you ask them? + +What would you ask +people to figure out + +that brand new product that's +different than anything + +ever before it. + +AUDIENCE: You talk +about what they actually + +want like why they use iPads. + +Maybe they want something easy +in front of them to touch. + +PROFESSOR: Yes. + +So to get the +underlying mechanisms. + +Yes. + +So we have expert education +here, as he said, correctly. + +Historical and cultural +explanations, as you + +said correctly. + +Ethnographic +research, as she said + +about observing someone +actually performing these tasks. + +This is how the +Swiffer was developed. + +They had people with cameras +watching people clean and mop + +their floors. + +And they thought, oh wait, +they do all these things. + +The water gets dirty +and all this stuff. + +And they could +develop these ideas-- + +the wet Swiffer and +the dry Swiffer. + +Here, direct observation. + +Sit there and listen +to those calls coming + +into the call +center, which I did. + +And I heard them say things. + +I sat down next to this person. + +You know when they say +the calls may be monitored + +for quality control +or quality assurance? + +Well, that was me +sitting next to her, + +jacked into the same box. + +And I said, I'm just +going to hear what you do. + +First call comes in. + +I've got a problem +with my TV thing. + +I can't get this +station and she'd + +have a very interesting thing. + +Did you diagnose it? + +She'd work with them. + +20 minutes later, it'd be done. + +The next call would come in. + +I've got this black screen. + +She's like, oh, +we'll, can you go in + +and unplug it and +plug it back in. + +Sure. + +Hey, it's working now. + +Great. + +Next call comes in. + +I've got this really +strange problem. + +I was getting these channels but +now I'm not getting anything. + +She'd diagnose it and +send it a restart signal. + +It would work. + +The next call would come in. + +I've got this snowy screen. + +She'd say, can you unplug it. + +Yes. + +And plug it back in. + +Yes. + +How's it working? + +Works great. + +Perfect. + +Every other call. + +Every other call. + +Black screen. + +Snowy screen. + +Black screen. + +Snowy screen. + +Unplug it. + +Plug it back in. + +Resolved. + +What's going on here. + +I said, how do you know +that's the problem. + +Oh, because the installers +say don't turn off the box. + +They'd say you +don't have to worry + +about turning off the box. + +Turns out if you don't turn +off the box every week or two, + +eventually it will +want an update, + +not get it, and produce +a black or snowy screen. + +And so she knew to do that. + +They were given +incorrect instructions + +by the people who +installed the box. + +And she gave them +better instructions. + +Well, kind of better. + +The better instructions +we're actually, by the way, + +you'll have to do +this periodically, + +even if the installer told +you you didn't have to do. + +So here by observing +that, we figured out + +that 30% of the calls to this +particular part of the call + +center were for a +black or snowy screen. + +Automation was introduced, +as you said-- who was it? + +Yes. + +Correctly. + +Automation was introduced +to solve this problem. + +The first question was, are you +experiencing a black or snowy + +screen. + +No. + +All right. + +Let me give-- Yes. + +Great. + +Unplug it and plug it back in +and let's see if that helps. + +I'll stay on the line. + +When you're ready, +just say I'm ready. + +And people would do that. + +They'd say I'm ready. + +Great. + +Did that solve the problem? + +Yes. + +Alright. + +You need to turn this +off, periodically, + +like once a week or two. + +otherwise you'll get +the same problem, + +even if the installer told +you you didn't have to. + +So that's how you +solve a problem. + +Observation. + +This is the hard one. + +And this is exactly +what you're alluding to. + +A deep understanding of humans. + +What they want. + +What their real desires +are-- technology, culture, + +manufacturing, philosophy, art, +design, and everything else. + +When you want something +really radically innovative + +you need to understand +a lot about a lot. + +And while you're in school, +you have an opportunity + +to learn a lot about the a lot. + +So take advantage of doing that. + +Steve Jobs sat in on +a calligraphy class. + +And that's why the first +Macintoshes had fonts. + +Before, there were no +fonts in computers. + +But he didn't have +this experience + +of what a font can do and +change meaning of something + +and he wanted that in that +first Macintosh computer because + +of the experiences of sitting +in on a calligraphy class. + +Have more experiences. + +Understand everything about +culture, technology, art, + +design, philosophy. + +It'll make you +better at designing + +very technical systems. + +Any questions about that? + +AUDIENCE: I would actually +disagree with that last point. + +You get more innovation +by just trying 100 ideas + +and seeing what sticks. + +PROFESSOR: You think you +can get more innovation + +by trying 100 ideas +and seeing what sticks? + +AUDIENCE: Yeah. [INAUDIBLE] +that make great things + +and have no idea +what they're doing. + +PROFESSOR: You think +people who make + +great things have no +idea what they're doing? + +AUDIENCE: In some cases, yeah. + +PROFESSOR: Can you +give me some examples? + +AUDIENCE: Some examples. + +If you think of a +product like Facebook. + +PROFESSOR: Facebook. + +He had no idea +what he was doing? + +AUDIENCE: Yeah, he was +doing something cool. + +Ended up making a lot of +money later on by [INAUDIBLE]. + +PROFESSOR: Making money. + +But that wasn't the objective. + +The objective was to +make something cool. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: But he didn't +try 100 different designs. + +Did he? + +He didn't just try a 100 +designs and see what stuck. + +AUDIENCE: They updated +code twice a day. + +PROFESSOR: That's not trying +100 different designs. + +Facebook has maintained-- +its core origin, + +at the very beginning, +was a rating. + +Hot or not. + +Right? + +So like, hot or not. + +You would just rate people. + +Then you started being +able to post more. + +And it involved. + +And when it evolved to +a certain point, then + +it became particularly big. + +But it wasn't that +they tried 100 designs. + +No one sat there and said, let's +observe 100 different things we + +could be doing for Facebook +and say, let's see what sticks. + +People don't often do that. + +It's also very +costly and expensive + +to try 100 different designs. + +AUDIENCE: If you look at how +they do agent testing everyday? + +PROFESSOR: Yes. + +But that's making +small decisions. + +But not radically +different things. + +We're talking about technology +that's never been seen before. + +A completely new type +of user experience. + +Something that's never +been tried before. + +Derivative things, absolutely. + +You can do ABN testing. + +You can test 100,000 +variations in an hour + +and see which ones +people used and which + +ones they took longer to use. + +But that's for small changes. + +Not when you're doing something +completely radical and new + +and very different +and very innovative. + +AUDIENCE: I just wanted to +support his point a little bit. + +I don't think that +anyone who designs + +these really good products +sits down one day and realizes, + +given everything I know about +art, technology, society, etc, + +this is how it should be. + +PROFESSOR: You don't think so? + +AUDIENCE: No, I don't. + +PROFESSOR: If you were +to design something, + +you wouldn't think that it +was the amalgam of everything + +you've learned in +your life so far? + +AUDIENCE: No, no. + +It wouldn't just come at once. + +PROFESSOR: It may +not come at once. + +AUDIENCE: Unlike +the other examples-- + +in the other examples, you +narrowed down the [INAUDIBLE] + +because you realized +this causes this. + +PROFESSOR: Oh, right. + +It is not a good example. + +Exactly. + +That is true. + +But it is the +synthesis of everything + +you've learned so far. + +Right? + +AUDIENCE: Right. + +But the process of getting +to the design that you get to + +is a meandering. + +PROFESSOR: Oh, yes. + +You may take a long time +to get to that design. + +Absolutely. + +Yes. + +But it is the idea +that, if you-- I'll + +bring this slide up again. + +If you don't have a deep +understanding of people, + +you're not going to design +things really well for them. + +If you don't understand +how the technology works, + +you won't be able to make +something that's useful, + +that people enjoy +interacting with that + +takes advantage +of the technology. + +If you don't understand +about the culture + +it may be the wrong +time to introduce it + +to a certain place. + +If the iPad was launched in a +poor country where they could + +never afford it, then it +may not be very popular. + +Or a place where there +wasn't internet reception + +for some reason. + +Or if you don't understand about +how to manufacture something + +like that, then it +gets very clunky. + +If you don't understand +about art or design, + +how do you make something +that's aesthetically pleasing + +and sustainable? + +So that's why the +idea is to synthesize. + +And yes. + +It takes a long +time to get there. + +That's why creativity gets +better as you get older. + +The older you get, the +more creative you will get. + +You don't get worse +with creativity. + +It gets better. + +Because you know more +and you have more life + +experiences that +you can synthesize. + +Other questions? + +Or comments? + +AUDIENCE: I feel +like it goes back + +to the conversation we +had about intention. + +PROFESSOR: Intention. + +The idea of intention. + +AUDIENCE: -and what +you intended it to do. + +I feel like it does require +the deep understanding + +of certain things depending +on what your design is. + +But it's like what +you said, it can + +evolve into different +things and that + +might mean you will look for +more understanding of humans + +and manufacturing maybe later on +depending on where the design-- + +PROFESSOR: So you'll +keep evolving that. + +Absolutely. + +You will definitely keep +evolving your ideas. + +Joel. + +PROFESSOR JOEL SCHINDALL: +Just to add a little bit, + +I hope you're not falling +into the school idea + +that these questions have +right and wrong answers. + +These are thought provoking. + +They're to get you +thinking about things. + +They're to challenge +your assumptions. + +Some of them are +absolutely ridiculous. + +But without looking at +that, it doesn't give you + +the perspective that +you're getting at. + +I think you've probably done +this in other sorts of classes + +but it's a different +type of perspective. + +And to get the most +value out of it + +you need to set aside-- +by the way, the people who + +are answering, I also want +to really hand it to you. + +Put yourself out there. + +Throw it out even if it's-- +there are not right and wrong + +answers. + +We need illustrations +of the wrong answers-- + +we need illustrations +of the wide range + +that people come up +with answers about. + +I think if you're sitting +here in this class, + +the answers that other +people are giving + +are a demonstration of the +wide range of reactions + +that people have to the same +stimuli that you receive. + +And you'll receive a stimulus +and you'll say, oh, yeah, + +of course that's true. + +And someone else is going +to say, I object violently. + +Now that's worth knowing +because that person's + +giving an honest reaction. + +PROFESSOR: The +whole point of this + +is to provoke your thinking. + +To make you think +deeper about this + +and to set the +stage for what you + +will be doing over the +course of the semester. + +It is meant to +challenge the ideas. + +We ask a lot of questions +about Dieter Rams' principles + +and you'll be +reflecting on that. + +But these are ideas. + +And they're not meant to say +this is an equation where + +when you put something in you +get something out like this. + +It's not deterministic that way. + +Design is a very, very +complicated thing. + +That's why we talk about it +for many different aspects + +and different approaches to +get you to think differently. + +Because you'll be able to +soon become much better at it + +through that process. + +AUDIENCE: So I know that 2.009 +is a very artificial setting + +because you're given +a theme and you + +have to design a product +based on that theme. + +But how do you think 2.009 +and that process fits with-- + +PROFESSOR: I don't know +a whole lot about 2.009. + +You said it's an +artificial setting. + +It's not that artificial. + +There are companies that have +innovation labs where they say, + +we do something with our +product in this space. + +Can you do something +with our product + +that takes advantage +of it somehow? + +And people have to figure +out, OK, what do I have. + +What are the resources? + +How much time do +I have to do this? + +Do I have an infinite +amount of time + +or a limited amount of time? + +And they do that same process, +just like you do in 2.009. + +PROFESSOR JOEL SCHINDALL: Blade, +let me comment on that also. + +Design takes place +at many, many levels. + +And sometimes, you just +have a group of flowers + +and you're trying to +make a floral design + +and you're very restricted +in what you can do, + +but there is a methodology, +there are rules. + +You can put the big +flowers-- I don't + +know how to do a good +one, so I better not + +give you examples of that. + +And on the other +hand, sometimes you're + +trying to do either a very +complex technical system + +or perhaps a complicated +political process. + +People design press briefings +for presidential candidates. + +It seems amazing. + +It seems they're +so bad it doesn't + +seem as if it could be designed. + +But it actually +is very carefully + +researched and designed. + +Now 2.009 places itself +kind of in the middle + +of the design space. + +It's more creative +than just figuring out + +how to assemble an erector set. + +And it does encourage you to +do some innovative thinking, + +but not as much-- we're trying +to go even one level higher + +and something that will +apply to everything you do + +and just, what we +call, design thinking. + +And it will help you +in 2.009, but it's not + +as specifically +applied to-- 2.009 + +is a mechanical engineering +course for people + +who intend to grow up and +design mechanical things. + +And so it focuses on that. + +This is more for people who +intend to deal with life issues + +and come up with answers. + +PROFESSOR: Whenever you have +to do anything-- in my software + +company, I apply +these principles + +to everything we do-- the +ones I'm teaching you-- + +to every aspect of it, +whether it's to hiring, + +to bring people on board, to +figure out what they're going + +to be doing the next week, +how we're going to communicate + +internally, how we're going +to communicate externally, + +which brings us to stakeholders. + +Cul Bono. + +What does it mean? + +Anyone know? + +Who benefits? + +Who benefits? + +So stakeholder. + +Well the definition I get +off the internet-- a person + +or group that has an investment +share interest in something. + +We talk about stakeholders +for your education-- + +you or your family, +teachers, school. + +Who else could be a +stakeholder for your education? + +AUDIENCE: The community. + +PROFESSOR: The community. + +What community? + +AUDIENCE: The one that you +would benefit if you go-- + +PROFESSOR: The +community that benefits + +when you go and do something. + +What else? + +AUDIENCE: Your employers. + +PROFESSOR: The employers. + +Yes. + +And actually +potential employers. + +Who else? + +AUDIENCE: The clients. + +PROFESSOR: Clients. + +When you're working at the +employer you have a client. + +Yes. + +AUDIENCE: I think the government +or the president in general. + +PROFESSOR: The government +or the president, or you + +could say the country. + +The country benefits. + +Absolutely. + +Who else? + +AUDIENCE: I don't know +if school includes + +this, but your classmates. + +PROFESSOR: Classmates. + +Sure. + +Tell me how your +classmates benefit. + +AUDIENCE: The more you +bring to the table, + +the more they're going to gain. + +PROFESSOR: Yeah. + +So when you have a certain +cohort in a business school, + +if there's people with +different experiences, + +they can bring new +ideas and formats. + +That's why we have +discussions like this + +at the beginning +of the lectures. + +You get more benefit because +you hear someone's idea + +that you hadn't thought +about before because they + +bring their perspective. + +Here's a quick sketch. + +Just a quick sketch +of how you might + +go about the process of +writing out the stakeholders. + +Flour Bakery. + +Who knows it? + +A lot of you. + +So this is a great +bakery, very close by. + +And its owner is Joanne +Chang, a friend of mine. + +And Joanne owns a bakery. + +So I'm going to say that +this is in the center + +and this is one of the +primary stakeholders. + +Workers would be another primary +stakeholder of the bakery + +because if the bakery's +selling product they get paid. + +There's a whole bunch of others, +of course, that we can fill in. + +Now we go from a secondary +one to the workers' banks. + +How do they benefit? + +Well, the Flour Bakery +gives the workers money. + +The money goes into the banks. + +So as we go through +that process, + +the bank begins to be able +to get more money into them, + +particularly a local bank, +perhaps, that's being used. + +And what's +interesting about this + +is there's a big +profound effect. + +What we're going to +do is we're going + +to have you do a quick +sketch for Flour Bakery. + +And what I want you to +do is to do that system + +with much more detail, +right now in class. + +And if you need to, +you can use lines + +to clarify what's happening. + +Someone pays someone, +like pay the workers, + +or the bank receives +cash as a result. + +I want you to work +in groups of three. + +If you have paper, please +draw this on paper. + +And then, we'll project +a few on the screen. + +So tidiness doesn't really count +as long as you can explain it. + +And you'll have about +10 minutes to do it. + +You can work with +any people you want. + +By now, the students +are trying to figure out + +how to map out a simple +stakeholder diagram. + +Now this is not a very full +or robust stakeholder diagram. + +It's just meant to +get everyone thinking + +about the system +that's involved. + +In a stakeholder analysis +that's done really well, + +you'd actually phase out +all the different levels. + +You'd think about all the +different stakeholders + +and where they lie in the +spectrum of value, too. + +Here we just want to make +sure that students understand + +the idea that +things are connected + +and that these connections +can seem very distant. + +But if they understand the +connections and the space, + +it can help them make +better decisions later on. + +And we'll be doing that in +the next slides that we show. + +We'll show what the students +have done on the screen. + +So the thing to +look for in this is + +to see if the students +pick up on some + +of the other more +subtle aspects. + +Are they going to think about +things like legal system + +or the accountant +or people like that + +who are direct benefits +and every store + +has to work with their legal +people and their accountants, + +but it doesn't seem like +it often pops in the radar. + +And this is where all +these hidden costs + +occur when someone's +starting a business. + +They think, well, this one's +going to cost this much + +or they're making a product +that's only this expensive, + +but there's everything +else around that ecosystem. + +And let's see if +they pick up on this. + +All right so let's +go over your results. + +Why don't we take +yours to start? + +Does that sound good? + +STUDENT PRESENTER +1: Sounds good. + +PROFESSOR: You can +take care of this. + +Let me know when you're ready. + +So you're going to +have to explain this + +because it's hard to get +the catch of this on here. + +But it's OK. + +Just walk us through it. + +In fact, use the +laser pointer-- this + +is the red button here at +the top-- to point out. + +Tell us what we have over here. + +STUDENT PRESENTER 1: +So immediately, you + +have the owner who benefits +up here and also the employer. + +And so from there, +their banks benefit. + +And that kind of leads +into the economy. + +PROFESSOR: Tell us about +just the first level, right + +around here. +[INTERPOSING VOICES] + +STUDENT PRESENTER 1: +And so the suppliers + +who supply the materials to +Flour, furniture, ingredients, + +and stuff like-- +they benefit as well. + +And then down here, you +have neighboring stores + +who benefit from the +popularity of Flour, + +bringing in more traffic. + +PROFESSOR: Neighboring stores. + +Really creative. + +They'll benefit from the fact +that it's a popular place. + +Keep going. + +STUDENT PRESENTER 1: +And so competition here, + +you can extrapolate, +to them being + +driven to produce better goods. + +PROFESSOR: Wow, so competition. + +That's very creative. + +Keep going. + +STUDENT PRESENTER +1: And this actually + +feeds back in to customers who +benefit from better quality. + +PROFESSOR: I guess competition +is a good drive out quality + +from other bakeries who +aren't starting to get good. + +Flour has to get better or +lower their prices or something. + +Keep going. + +STUDENT PRESENTER 1: Right. + +And so the second level +here, back to the banks-- + +they benefit from +both the owners + +and the employers making income. + +And then down here, you have +friends slash the community. + +Say you refer a +friend and they really + +like Flour, that's +a benefit for them. + +PROFESSOR: So it's a +benefit for the customer + +if I refer a friend. + +It's a benefit to me if I +refer you to go to Flour. + +STUDENT PRESENTER 1: +It's a benefit for me + +if you refer me to +Flour and I like it. + +PROFESSOR: So you +get the benefit. + +But are you attached +to me or are you + +attaching directly to Flour? + +In other words, do you +benefit directly from Flour? + +STUDENT PRESENTER +1: That's fair. + +You could say that I +definitely benefit from Flour + +as well if I like it. + +PROFESSOR: So maybe +this kind of line + +would be a dotted line-- +provides information to, + +and then directly from. + +Sure. + +Keep going. + +STUDENT PRESENTER 1: And so +naturally, the nearby community + +also branches off from +the neighboring stores. + +One more thing we have +over here is the publishers + +because apparently Flour sells +cookbooks and stuff like that. + +PROFESSOR: Flour +sells cookbooks. + +There's a publisher involved. + +And they love it. + +The more Flour bakeries that +are around or the more people + +know about it the more +cookbooks they buy. + +STUDENT PRESENTER 1: And so +this leads to the bookstores, + +I think. + +PROFESSOR: Book stores. + +Absolutely. + +STUDENT PRESENTER 1: And this +actually feeds all the way back + +to the economy. + +And from the economy-- + +PROFESSOR: The economy "boomph." + +Giant. + +The beneficiary. + +That's great. + +And what comes off the economy? + +STUDENT PRESENTER 1: And so +this is where we got creative + +and said that the +government, the president + +benefits from the +economy being strong. + +And then you can even pull +out the political parties + +if you wanted to. + +PROFESSOR: Sure. + +So political party, government. + +This is great. + +So Flour makes America strong. + +Forget GM. + +Forget Ford. + +Flour does it. + +I love that. + +It's a great job. + +[APPLAUSE] + +Who's up next on +the chopping block? + +Let's get this going here. + +You get this. + +I'll give you this to hold. + +I'll give you this +to use as well. + +Let's talk about this. + +Walk us through it. + +At the center is Flour. + +What else we got? + +STUDENT PRESENTER +2: So we have Flour. + +And then it first goes to +the banks and investors. + +PROFESSOR: Investors. + +Yes. + +STUDENT PRESENTER 2: So banks. + +So people who have +money in the bank. + +So it's really important that +the banks are doing well. + +Similarly, people +who are friends + +with the people +with money the banks + +who needed to be spotted for +a meal at Flour also benefit. + +So we also have the workers. + +Their taxes go to the +government which helps America. + +And then workers. + +Their families also benefit +from the making income. + +And then it goes to +the school system. + +PROFESSOR: How's it go +to the school system. + +STUDENT PRESENTER 2: Because +the children go to school. + +And then, thus, +benefits citizens. + +PROFESSOR: So money goes from +Flour Bakery to the workers. + +The workers give money +to their families? + +STUDENT PRESENTER 2: Yes. + +PROFESSOR: And so how does +that benefit the school? + +STUDENT PRESENTER 2: Because +then the children go to school + +and get educated. + +You need people to go to school. + +PROFESSOR: How do the +families pay for that? + +STUDENT PRESENTER 2: +Through their taxes. + +PROFESSOR: Through taxes. + +STUDENT PRESENTER 2: +And then the government. + +PROFESSOR: Before it gets to +the school, where does it go? + +To the IRS. + +STUDENT PRESENTER 2: That too. + +PROFESSOR: And +them to the school. + +STUDENT PRESENTER 2: Yes. + +PROFESSOR: To the IRS first +and then to the school. + +STUDENT PRESENTER 2: Yes. + +PROFESSOR: Yes. + +That is true though. + +STUDENT PRESENTER 2: And it +goes back to the citizens + +because then you have +an educated population. + +PROFESSOR: So Flour Bakery +educates the population. + +I love that. + +We'll tell Joanne. + +She's going to love this. + +STUDENT PRESENTER 2: Then +kind of going on a more fun + +note-- so we also had +neighboring companies, + +such as Novartis who's like +a biotech drug development + +company which helps hospitals. + +And then the patients +can go to Flour. + +PROFESSOR: Lovely. + +Keep going. + +STUDENT PRESENTER +2: Similarly, we + +have more customers +such as MIT students. + +And so our parents benefit +from us getting an education. + +Professors and other MIT +employees who go to flour. + +And also the world slash +everybody is invested in. + +PROFESSOR: The world. + +I can't wait til the next +one that says universe. + +That's good. + +Big round of applause. + +[APPLAUSE] + +We've got time for +one more example. + +Who-- yes. + +Let's take your example. + +Cannot wait to see it. + +STUDENT PRESENTER 3: So ours is +similar to many of the others. + +We have some things that +other people didn't have-- + +PROFESSOR: Point +out the differences. + +STUDENT PRESENTER +3: --in local gyms. + +PROFESSOR: Local gyms +benefit from Flour. + +STUDENT PRESENTER 3: They do. + +PROFESSOR: Tell us why do local +gyms benefit from a place that + +sells lots of bakery +confectioneries. + +STUDENT PRESENTER 3: +Flour is really delicious. + +And then people eat a lot of it. + +And they get really fat. + +And then they would like to +lose some of those calories. + +PROFESSOR: So the Z +Center, the MIT gym, + +benefits from Flour being there +because more people use the Z + +Center who may not otherwise +use it because they're saying, + +I love Flour so much but I've +got to work out the calories. + +STUDENT PRESENTER 3: Exactly. + +PROFESSOR: Local bike +shops maybe as well. + +STUDENT PRESENTER 3: So +their employees benefit too. + +PROFESSOR: Their employees +absolutely benefit. + +Yes. + +STUDENT PRESENTER 3: And we also +had hospitals in that similar-- + +PROFESSOR: As Diabetes go up. + +STUDENT PRESENTER 3: Exactly. + +PROFESSOR: Yes, they're so +tasty they cause diabetes. + +STUDENT PRESENTER 3: Precisely. + +PROFESSOR: And +hospitals benefit. + +And doctors from selling-- + +STUDENT PRESENTER 3: And +the doctors' families. + +Yes? + +PROFESSOR: And the +doctors' families benefit. + +STUDENT PRESENTER 3: Exactly. + +PROFESSOR: Now this may sound +bizarre, but this is true. + +This is how it happens. + +Imagine that we had to work +it out for a tobacco company. + +All the people that benefit +from a tobacco company + +selling things, +including people who + +are injured by tobacco +because of cancer. + +So that's all true. + +What else do we have? + +STUDENT PRESENTER 4: +We had aspiring chefs + +because of the cookbook. + +So they can see that. + +Or even aspiring +restaurateurs who + +see how the owner set +up Flour and maybe + +use it as an example +or inspiration. + +PROFESSOR: Brilliant. + +What else do you have? + +What else is brilliant? + +STUDENT PRESENTER +5: We also have + +how MIT is generally affected. + +So if students are eating at +Flour instead of the dining + +hall, then that's affecting MIT. + +That's affecting the +classes and the professors + +and your classmates. + +PROFESSOR: And maybe for good. + +Maybe not for food. + +This is great. + +This is an excellent one. + +Here's a question. + +Did anyone get lawyers? + +Good. + +Two groups. + +How about accountants? + +One group. + +Excellent. + +Every business deals with +lawyers and accountants. + +Lawyers accountants +all the time. + +Every business, no +matter what, deals + +with lawyers and accountants. + +It should be on all of +these because, no matter + +what-- and particularly +as a business owner-- boy, + +I get on the phone +with my lawyers, + +I talk to my accountant. + +I can't even avoid it. + +It's not even possible +to avoid, particularly + +when you have to hire people and +fire people and the whole bit. + +That's why they're such +big businesses-- why + +accounting and the law +are such big businesses-- + +because everybody +needs to use them. + +Any other people have +examples of beneficiaries + +who we didn't list? + +AUDIENCE: Insurance companies. + +PROFESSOR: Insurance companies. + +Yes. + +Absolutely. + +AUDIENCE: The farmers. + +PROFESSOR: Farmers. + +People actually grow this stuff. + +Absolutely. + +People grow stuff and +have more supply chains. + +And this is true. + +Flour Bakery may +have a little impact, + +but McDonald's has enormous +impact on cattle companies, + +and people who supply +tomatoes and lettuce and all + +those things. + +Absolutely. + +Huge impact. + +Industries are built +around these things. + +AUDIENCE: We also listed +internet providers + +because they offer free +Wi-Fi to the customers. + +PROFESSOR: Free Wi-Fi to +the customers as well. + +Let's go back to slides, please. + +Thank you. + +This is excellent. + +You did a great job. + +Did we give them a +round of applause? + +[APPLAUSE] + +You got that. + +This is what we +care about though. + +Why do we care about +doing this and why are you + +going to be doing +this yourselves? + +It's starts out with +systems thinking. + +Establishing a +global perspective + +about the little problem +you're trying to solve. + +If I said, make a +calculator-- a calculator + +doesn't exist in isolation. + +It affects a lot of things and +can affect a lot of things. + +We want to maintain a +really big perspective + +over every small +decision we make. + +Because of that, +we can understand + +how to make good +decisions and trade-offs, + +establish priorities or +reestablish them, and be + +able to communicate +more effectively. + +Not all stakeholders have +the same amount of value + +to a company. + +Different stakeholders hold +different kinds of value. + +Joanne may say, look, I +really care about my customers + +but she may not +say, I really care + +about the people +who work at the gym. + +So she may not say, let me +put extra fat in the products + +and then advertise, by the +way, with these things, + +if you care about +it, I'll give you + +a discount to the +gym membership. + +Which stakeholders +do we benefit more + +and which stakeholders +benefit us more? + +Sometimes, in a +nonprofit, we might + +think we really want to get +the best thing out there + +no matter what because we +don't care about making profit. + +Other times you think, well, we +want to get the best thing out + +there, kind of, but +we also want to make + +sure we're balancing that +out with our stakeholders. + +An example of this +is angel investors + +versus venture capital. + +If you're starting a +company, angel investors + +will give you a +little bit of money. + +It's a little bit +easier to get the money. + +And there's far fewer strings +attached to that money. + +A venture capitalist will give +you money-- much more money, + +but they have a lot +more requirements. + +And so each of them need +different kinds of things. + +Angel investors don't need +a whole bunch of return + +on their investment. + +And a venture +capitalist says no, we + +want to make a ton of cash. + +So we'll give you +more, but we're + +going to take a lot more back +and have more requirements. + +So different kinds +of stakeholders + +would allow us to figure +out which do we use. + +If we understand this +network very clearly, + +it helps us to understand +priorities and trade-offs. + +And then, if I +understand this diagram + +and convey this to +you very specifically, + +it could help us align the team. + +So my software is sold +to people at companies. + +If everybody in my +company knows who + +those people are, who makes +the buying decisions, who + +is going to use it. + +Are they the same people +or different people. + +How do I make sure that +the buying person gets + +what they need and the person +using it gets what they need. + +They may need different things. + +And even though the +people who use it + +may use 90% of the +functionality and the people who + +buy it may use almost +none of it, or 1%, + +do I want to invest that +1% of the functionality + +even if it costs me a +lot of time and effort? + +Maybe I have to. + +So it can reveal hidden +cost and opportunities. + +A cost. + +A student can get an +easy or a difficult C. + +From a parent's perspective, +which is better? + +The easy A or the +really difficult say? + +Please pass the class. + +I'm your parent paying for it. + +I don't want to have to pay +for you to take it again. + +So maybe they might +think it's really better + +to have an easy A class. + +But maybe from the +student's perspective, + +they think, the +harder C is-- I'm + +going to learn a lot more in. + +And it's better for +me and my future. + +Or an opportunity. + +If a company has enough +employees, for example, + +a company can get +better buying power + +with vendors or the +gym or something. + +Because we have +so many employees + +they say, look, we want +to have our employees go + +to your gym or maybe +some competitor's gym. + +If you give a bigger discount, +we have more buying power. + +Or to the vendors like Walmart. + +Walmart doesn't pay +much for anything + +because they sell so much. + +And it's such a +valuable brand to have + +when you're selling +something that they + +make their vendors cut +their prices way down-- as + +low as they can +possibly get them. + +And the idea is that +for them is they + +pass their savings +on to the customers. + +For the homework, I +want you to map out + +primary and secondary +stakeholders, + +and more if you'd +like for two things. + +An art museum and a new +kind of battery technology. + +So one's a museum and +one is a technology. + +Starting with technology +in the center. + +I'm thinking about that. + +All the different +ways it connects + +to everything else around it. + +A new kind of better technology. + +If you have something in +mind, you could use that. + +Just let us know what you used. + +And if you don't really quite +know about battery technology, + +you could just kind of think +about what it might affect. + +That's the objective here. + +Understanding your stakeholders +will make a huge shift + +in your ability +to make decisions, + +to think globally from +a systems perspective. + +And if you can do that +on little small projects, + +as the projects get bigger and +more complicated and complex, + +you'll be able to +make better decisions. + +And it will help +you make decisions + +when you're not too sure what +to do because at least you'll + +have a framework and be +able to communicate that + +to other people on the team. + +And they can say, +yes, we understand + +that that's an important +feature to add-- + +to spend weeks or months +adding because someone needs it + +in order for us to +sell the product. + +Any questions about +stakeholders or research + +or Dieter Rams or Johnny Ive? + +AUDIENCE: Is the +homework for Monday? + +PROFESSOR: This +homework is for Monday. + +In fact, I will show +you on the next slide + +what you've done so far. + +We had an introduction. + +We went over the 10 +step design process. + +We actually moved +Dieter Rams to today. + +And what's due on Monday +is the game design + +and the stakeholder +analysis for games. + +Have a wonderful weekend. + +If you have any questions, +email us at eid-questions. + +Thank you. \ No newline at end of file diff --git a/zfBXJQ-i6p8.txt b/zfBXJQ-i6p8.txt new file mode 100644 index 0000000000000000000000000000000000000000..e5113f9b64ba7e214a63986f51d202b4be908ba0 --- /dev/null +++ b/zfBXJQ-i6p8.txt @@ -0,0 +1,3521 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation, or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Well, we +are in the middle + +of something really interesting. + +We are talking about squeezing. + +We are talking about +non classical light. + +And today, I sort of +want to wrap it up. + +And I think it will really +be an exciting class. + +But before I continue +with the material, + +I want to address a question, +which actually came up + +in discussions with +several of the students. + +And this is, I realize +that some people said, OK. + +Everything makes sense. + +But what are we plotting? + +What is really squeezed? + +Are we squeezing in +the spatial domain? + +Are we squeezing in +the temporal domain? + +So the plots look wonderful, +with these ellipses + +and the circles. + +But, what is it really +we are doing here? + +So let me address that. + +First of all, we are talking +about a single harmonic + +oscillator. + +We showed that the +[INAUDIBLE] equations + +can be reduced to a bunch of +harmonic oscillator equations. + +One for each mode. + +And now we are +talking, today and + +in the previous few classes, +about one single mode, + +about one harmonic oscillator. + +And the harmonic oscillator +has canonically variables + +of momentum and position. + +But this is just to make +a connection for you + +with something you have learned. + +What we are talking about is +a single harmonic oscillator, + +which is one single mode of +the electromagnetic field. + +So maybe let me draw +a cartoon for that. + +So let's assume +we have a cavity. + +We have an electromagnetic wave. + +There is propagation, +where it's e to the ikz. + +There is transverse confinement. + +Maybe there is a +Gaussian e to the minus + +x squared plus y squared over +sum [INAUDIBLE] parameter. + +All of that is simply +the spatial mode. + +And we just take that for +given because we're not + +solving the spatial +differential equation. + +All we are doing is we are +looking at this one mode. + +And the two degrees +of freedom is + +that this mode can have a +certain number of photons. + +It's the amplitude. + +And the second one is you +can see the temporal phase. + +It can be a cosine omega t. +it can be a sine omega t. + +It can be a superposition. + +But whatever we are talking +about is in this mode. + +There is nothing happening +in the spatial domain. + +They're just asking, what is +the oscillation in this mode? + +The whole mode does +what it should. + +It has a prefect, of +which is the amplitude. + +And it has a temporal effect +of which we factor out. + +And this is what we +are talking about. + +Let me be a little +bit more specific + +and say, that when we +are plotting things, + +we are plotting the Q +representation, the phase space + +representation of the +statistical operator, + +which is simply describing +this single mode + +of the harmonic oscillator. + +And by performing the +diagram matrix elements, + +we obtain the Q distribution. + +In that case, we +have the vacuum. + +We have a displaced vacuum, +which is in coherent state. + +And our x's are, from +the very definition, + +in the complex plane +with a real part + +of the imaginary part of alpha. + +However, we can also +define [? the Veetner ?] + +distribution, which is another +phase based distribution. + +It's almost the same +as the Q distribution. + +It's just this little +bit smeared out + +by h bar because of +some commutators. + +But nothing you +have to worry about. + +In that case, the +projection of the W function + +on the vertical +axis, on the y-axis, + +is the momentum wave +function squared. + +On the x-axis, it is the +spatial wave function + +squared of the +harmonic oscillator. + +So therefore, we +may sometimes think, + +when we have a distribution +here, we project it. + +And we see what is the +momentum distribution. + +Or what is the +spatial distribution + +of the mechanical +harmonic oscillator. + +Which is analogous, +which is equivalent, + +to the one mode of the +electromagnetic field + +we are using. + +I know it may help +you to some extent + +to think about the P and Q. +But it may also be misleading + +because it gives you the +impression something is moving + +with a momentum +P, in real space. + +Let me therefore +emphasize what are + +the normalized forms of P and Q. + +If I do the symmetric and +anti-symmetric combination + +of the annihilation +and creation operator, + +I over squared root 2. + +I call those a1 and a2. + +And they are nothing +else than Q and P + +normalized by the characteristic +momentum of spatial coordinates + +of the harmonic oscillator. + +So what is important +here is that a1 and a2-- + +forget about P,Q now. + +They are equivalent. + +But for the +electromagnetic field, + +a1 and a2 have a very +direct interpretation. + +They are called the two +quadrature operators. + +And what I mean by +that becomes clear + +when I use the +Heisenberg representation + +for the electric field. + +And I'm here using +the formula which + +is given in the book of +Weissbluth, in page 175. + +Some pages copied +from this book have + +been posted on the website. + +So we have our +normalization factor, + +which is related to the electric +field of a single photon. + +We have the polarization factor. + +But now we have an +expression which + +involves the quadrature +operators, a1 and a2. + +Just to be specific, we +are not in a cavity here. + +Therefore, we have propagating +waves cosine (kr) sine (kr). + +But you can also immediately +use a similar expression + +for the case of a cavity. + +Let us specify that r equals 0. + +And then we realize what the +two quadrature operators are. + +a2 is the operator which +creates and annihilates + +an electromagnetic +field, so to speak, + +photons, which have +an electric field. + +Which oscillates +as cosine omega t. + +And a1 is the quadrature +operator for the sine omega t + +component. + +So therefore, if you simply +analyze the electric field, + +what is cosine omega 2 is +related to the a2 quadrature + +operator. + +The sine omega 2 oscillation +is related to the a1 quadrature + +operator. + +So life would be +easier, but more boring, + +if you could create a +pure cosine, or pure sine + +oscillation of the +electromagnetic field. + +But you can't because a1 +and a2 do not commute. + +And there is an +uncertainty relation + +that delta a1 times delta a2 +is larger or equal to 1/2. + +And we have the equal sign +for coherent states alpha. + +So therefore, if we look +at the electric field, + +you know, everything +moves around + +periodically in r because +it's a traveling wave and t + +because it's an +oscillating wave. + +So let's not confuse things +with simply peak r equals 0. + +We've already done that. + +But now let's peak t equals 0. + +That t equals 0. + +The sine omega t is 0. + +And therefore, the distribution +for a2, the expectation value, + +and the variance for the +quadrature operator, a2, + +can be simply read off by +looking at the electric field. + +So, in other words, +at t equals 0, + +the electric field, +which is obtained + +by projecting our quasi +probabilities on the y-axis, + +gives the expectation +value for a1 + +and the variant, +delta a1 squared. + +Somebody says 2. + +That t equals 0. + +Yes. + +Yes. + +And now, if you want to see what +the other quadrature component + +is, well. + +We just wait a quarter period +until the sine, which was 0, + +is maximum. + +And the cosine omega t is 0. + +So therefore, it's +pi over 2 omega, + +using the projection on +the y-axis, gives us a1. + +And delta a1 squared. + +Or, alternatively, we +don't need to wait. + +We can do t equals 0. + +And we can project +onto the x-axis. + +Let me just throw few +things into this diagram. + +If you had a classical +motion, which + +would simply be cosine omega t. + +Then that would mean, if +you had a motion which + +where only cosine +omega t-- yes, it + +would be a point on the y-axis. + +However, classically +we can never + +have something which +is just cosine omega t. + +The point has to +blurred into a circle. + +This is the coherent state. + +So this coherent state has +now-- let me just call it 1, + +for the sake of the +argument-- the point + +would be the +classical oscillator. + +It is just cosine omega t. + +Everything is deterministic. + +No uncertainty. + +No nothing. + +Of course, it means that +the time of evolution, + +it goes in a circle. + +But this is what everything +does in an harmonic oscillator + +when time evolves into the +e to the i omega t factor. + +So let's not get +confused with it. + +Let's just look at t equals 0. + +And we input [INAUDIBLE] +if r equals 0, + +the classical +oscillator is one point. + +But now, we have a spread here. + +This says that trying +to mechanically + +the amplitude of the +cosine omega t term + +is not entirely false. + +It's not [INAUDIBLE] sharp. + +There are fluctuations. + +And in addition, we have +ellipse in this direction, + +which we project +onto the x-axis. + +And this tells us what the +distribution in our ensemble, + +in our kind of +mechanical ensemble, + +is for the amplitudes of +the sine omega t motion. + +So the best we can do +is try to mechanically-- + +if you want to have something, +which is really just cosine + +omega t. + +We have to squeeze it, that the +cosine omega t amplitude is now + +extremely sharp. + +But the sine omega t +amplitude in the ensemble + +is completely smeared out. + +So this is what +we're talking about. + +Now, what I think has +confused some of you + +is what I thought was +a wonderful example. + +The classical +squeezing experiment. + +I mean, these are visuals which +will be in your head forever, + +when you saw Professor +Pritchard with a circle pendulum + +he's just pulling. + +And then the circle +squeezes into an ellipse. + +And it seems that something +here is squeezed in real space. + +But this is actually wrong. + +But how you should have +looked at the experiment, + +and I made a comment +about it, but maybe not + +emphatically enough. + +You should have really thought +about a single pendulum. + +And this single pendulum, if +it has an [INAUDIBLE] phase, + +is in a superposition of sine +omega t and cosine omega t. + +And if you pull on the string, +if you shorten and lengthen + +the pendulum, it's +sine 2 omega t. + +You will amplify the prefactor +in front of sine omega t. + +And you will exponentially +de-amplify the factor + +in front of cosine omega t. + +So therefore, what will happen +if this pendulum oscillates-- + +and let me say with a phase, +well, sine omega t plus delta, + +if delta is 90 degrees. + +Cosine if delta is 0. + +It's sine. + +And let's say this pendulum +oscillates at 45 degrees. + +Sine omega t plus 45 degrees. + +If you now parametrically +derive it with squeezing action, + +it would now mean +that you, let's + +just make it a sine convention. + +You de-amplify the cosine. + +You amplify the sine. + +And after a while, instead of +oscillating with sine omega + +t plus 45 degrees, +it will oscillate + +with an amplified +amplitude at sine omega t. + +This is what you have done. + +And this is a +mechanical analogy. + +There is, of course, +no squeezing in any way + +because in a +classical pendulum, we + +start with one definite value. + +If you prepare the system well. + +And then, we just +change the motion. + +We amplify. + +We pick out a phase and +that's what we are doing. + +Now the true ways how classical +squeezing can come in. + +One it is if the motion of +the pendulum is-- maybe there + +is an uncertainty. + +Maybe Professor Pritchard did +experiments with an ion trap. + +And actually, 20 years +ago, he published + +a [INAUDIBLE] [? letter ?] +on classic squeezing. + +And you think, how +can you publish + +[INAUDIBLE] [? letter ?] +on classical squeezing? + +Well, he had developed the +world's most accurate ion trap, + +measuring atomic masses with +10 and 11 digit positions. + +And what was actually +one limiting factor + +was for Kelvin, the +thermal distribution + +of harmonic oscillator modes. + +And so, he didn't have +just one clean amplitude. + +The sine omega t +amplitudes had a spread + +because of the thermal +distribution he started from. + +And so what he then did is, +by simply classical squeezing + +by doing classically +with the ion trap + +exactly what he did with the +pendulum, derive sine 2 omega + +t, he could now take this +classic distribution. + +This is a classic distribution. + +In one axis, it's a +distribution of amplitudes + +of the cosine motion. + +And here it's the +classic distribution + +of the amplitudes +of the sine motion. + +And he was squeezing +it into this direction. + +So he had a narrower +definition of the coefficient + +for the cosine omega t motion. + +And as I will tell +you today, you + +can now do a +homodyne measurement, + +which is reducing the noise. + +So essentially, he prepared, +quote unquote "Effectively + +a [? code ?] ensemble by +squeezing the uncertainty + +in the cosine prefactor." + +Or at the expense of +increasing the prefactor, + +the uncertainty, the variance, +in prefactor of the sine omega + +t motion. + +Finally, you all saw +something visually. + +You saw how a circular motion +became a linear motion. + +So what was going on here? + +Well, I mentioned to you that +the circular pendulum actually + +has two modes. + +These are two modes of +the harmonic oscillator. + +And I'm not talking +about two modes + +of the harmonic oscillator. + +Everything we're discussing +here is about one mode + +of the harmonic oscillator. + +The circular motion +of the pendulum + +was just a nice +visualization trick + +that, if the pendulum +moves in a circle, + +you have a degenerate +harmonic oscillator. + +One is excited +with sine omega t. + +The other one is excited +with cosine omega t. + +And instead of doing +two experiments, + +if you would start +with sine omega t, + +and you parametrically +drive it, you amplified it. + +If you start with +cosine omega t, + +you could bring the +pendulum to a stop. + +But instead of doing +two experiments, + +Professor Pritchard +just did one. + +And he showed that the sine +omega t motions became larger. + +And the orthogonal cosine +omega t motion shrank. + +And therefore, you saw that +the circular motion, which + +was a superposition +of sine and cosine, + +became [? pure ?] sine motion. + +But the fact that +there was something + +we could see in +the spatial domain + +was simply due to the fact that +we had two experiments in one. + +Two versions of the same +harmonic oscillator, + +one in x and one in y. + +And then, when we +did the experiment, + +we saw something visually +in the spatial domain. + +So that's why we saw squeezing +in the spatial domain. + +But you should really +think about it. + +What the whole +action is, is it's + +an interplay of de-amplifying +prefactors of cosine amplifying + +prefactors of sine. + +And if the prefactor +has a distribution, + +by de-amplifying +it, you also shrink + +the reach of the distribution. + +And this is what +we call squeezing. + +Yes, [INAUDIBLE]? + +AUDIENCE: Stupid question. + +So the operators, a1 +and a2 here, right? + +You use those instead of a and +a dagger because you use cosine + +and sine rather than +[? e to the i omega t ?] + +[INAUDIBLE]? + +Because they should +contain [INAUDIBLE], right? + +PROFESSOR: Let me go +back to the definition. + +They are actually exactly +they correspond exactly + +to position and momentum of the +mechanical harmonic oscillator. + +AUDIENCE: Oh. + +That makes sense. + +Another thing is, +technically speaking, + +we could call the +[? Basco ?] electric field + +e cos kr minus omega +t as maximum squeezed + +if we only had the +cos components? + +PROFESSOR: Well, +not if I use it-- + +it depends how I +define squeezing. + +So you would now +give a definition + +of squeezing which says +that the variance in a1 + +is now unequal to +the variance in a2. + +So the classical +oscillator is the point. + +It has 0 variance in a1. + +0 variance in a2. + +But as I said, you can +actually apply all the way + +to a classical +oscillator if you add + +technical noise +or thermal noise. + +Then your system is prepared, +not with a sharp value, + +but with a distribution +which is simply + +may be [? false ?] distribution, +due to the preparation. + +So recall, it's +squeezing when the noise + +in the amplitude +of the sine motion + +is not equal to the noise in the +amplitude of the cosine motion. + +Some people say, if it's +a little bit narrower, + +they apply squeezing +to the situation + +that we are uncertainty limited. + +And then we squeeze. + +But of course, you can always +reduce the noise in your system + +by just preparing the system. + +By cooling the system. + +By selecting the system for +measurements, until you reach + +the quantum limit. + +So you can get a smaller +delta a1, a smaller delta a2, + +without squeezing, just +better preparation. + +Or by selecting your ensemble. + +So squeezing in a narrower +sense only makes sense + +when you hit the limit of what +quantum mechanics allows you. + +And now you want to distribute +the variance unequally + +between a1 and a2 +because then you + +can get something in +delta a1 or delta a2. + +Which is better then +1 over square root 2. + +And this is now really +quantum mechanically squeezed. + +But they're both definitions. + +Classical squeezing exists. + +It's just not as common as +quantum mechanical squeezing. + +Other questions? + +Yes? + +AUDIENCE: I remember +that you said + +that in the classical +squeezing, you + +are attenuating one amplitude. + +And you were amplifying +the other amplitude. + +So, in this picture +then, shouldn't we + +have the ellipse come down +from the circle on the y-axis? + +PROFESSOR: OK. + +AUDIENCE: [INAUDIBLE] not +just changing delta a, + +but also changing b [INAUDIBLE]. + +PROFESSOR: Let me just +get a sketch up here. + +So this is a2. + +This is a1. + +a2 is for the cosine omega t. + +And a1 for the sine omega t. + +So just to be specific. + +So you want to prepare an +harmonic oscillator, which + +is just sine omega t. + +This is a point here. + +If we are now parametrically-- +so this has a value at t + +equals 0. + +Our a1 is not. + +So if you are now squeezing your +classical harmonic oscillator, + +you would have a situation +where a1 of t is s + +naught times e to the plus +or minus t, depending on + +whether you do the parametric +[? drive ?] at sine 2 omega + +t or cosine 2 omega t. + +So therefore, what +would happen is + +this point will be amplified. + +That would mean it would +just move out on the x-axis. + +So this would be +for the plus sign. + +Or, for the other case, you +would damp the motion to 0. + +And this is a minus sign here. + +AUDIENCE: OK. + +And you were also +saying the variance-- + +PROFESSOR: A point +does not have variance. + +AUDIENCE: [INAUDIBLE]. + +PROFESSOR: So if you +want to build a variance, + +you need, let's +say, three points. + +One is the average value. + +One is the left outlier. + +One is the right outlier. + +And what happens is now, +as you amplify the motion, + +you would also amplify, +magnify the distance + +between the points. + +And if you de-amplify +it with a minus sign, + +the distance between +the points would + +shrink because all the +three points converged to 0. + +So pretty much what +I just told you + +for the three point ensemble. + +You can now use it and construct +any initial condition you want. + +And see what happens +due to squeezing. + +Other questions? + +Good. + +So the question now is, +how to measure squeezing. + +How to take advantage +of squeezing. + +So the situation we are +facing is the following. + +Let's assume we have done +a nice squeezing job. + +And that means that +we have a sharp value. + +We have created a +narrow distribution + +of the cosign omega +2 coefficients. + +So the cosine omega 2 +motion is rather sharp. + +But we also know that +the electric field itself + +is sharp at this moment. + +But since this ellipse +rotates, the electric field + +will have enormous uncertainty +a [INAUDIBLE] period later. + +So if we want to take +advantage that we have squeezed + +the electromagnetic +field, they are now + +a couple of ideas +which we can use. + +One is we could just +measure the electric fields + +stroboscopically. + +We would just make +a setup, where + +we look at this system +in a [INAUDIBLE] + +measurement process. + +Only, we only measure +the electric field + +when the ellipse is like +this or is like this. + +And therefore, we have a sharp +value of the electric field. + +But instead of doing a +stroboscopic measurement, + +we can do something else. + +Remember, we have a +distribution of cosine omega t + +and sine omega t. + +And we have a distribution +of co efficiency and s. + +And we know we are interested +in the cosine omega t. + +So how to pick that +out has actually + +been solved in +early [? radius ?]. + +You do a homodyne detection. + +In other words, you take +a reference oscillator, + +which is strong. + +B of t is b naught times +cosine omega naught plus delta. + +And if you if you +multiply the two signals, + +your signal you are +interested in, or at least + +you're interested +in one comportment, + +you multiply it with +your local oscillator. + +And then you +[? indicate ?] over time. + +Then, of course, when you +peak the phase delta to be 0, + +cosine omega t times +cosine omega [? dt ?] + +gives cosine squared omega t. + +It averages to 1/2. + +So you would times average +where cosine omega t + +times sine omega +t averages to 0. + +So for delta equals +0, you project out + +the cosine component. + +And for delta equal +to 90 degrees, + +you peak out the sine component. + +So therefore, you can +have a measurement, + +it's a phase +sensitive measurement, + +by multiplying your signal with +the local oscillator, where + +you're only sensitive to the +component you have squeezed. + +And therefore, your +measurement uncertainty + +has now been reduced by +the squeezing factor. + +AUDIENCE: [INAUDIBLE] only +that should be the [INAUDIBLE]. + +PROFESSOR: Yes, +actually, homodyne + +means we use the same frequency. + +Heterodyning would mean we +use two different frequencies. + +But I'm not talking about that. + +So we have to use exactly +the same frequency here. + +AUDIENCE: So instead, this +[INAUDIBLE] oscillation + +also needs a laser +to [INAUDIBLE]? + +PROFESSOR: Yes. + +So, to address your question, +Angie, what usually happens + +is you start with one +laser in those experiments. + +You frequence the +top of the laser. + +If you wanted to +do some squeezing, + +you remember that we need a +parametric oscillator, where + +one energetic photon +gives us two photons. + +So what you do is you start +with a laser, [INAUDIBLE]. + +A 1064 nanometer. + +You frequency double +it to green laser. + +The green laser pumps your +parametric oscillator. + +And then you get, +for down conversion, + +you can squeeze light at 1064. + +But this is because you +first stopper the laser. + +And then you break the +photon into new pieces. + +It has exactly the same +frequency as your laser + +you started with. + +And this laser is in the local +oscillator, or the reference + +clock, for your +whole experiment. + +So everything in your +experiment, the double laser, + +the parametrically +down converted beams. + +Everything is related to the +single laser you started with. + +And everything is +phase coherent. + +So that's how, usually, +the experiment is done. + +Before I tell you what we're +doing quantum mechanically, + +let me just also +get another question + +out of the system, which I've +been asked several times. + +People ask me, +well, the problem is + +that the ellipse +rotates like this. + +Isn't there a way-- +now I need my hand-- + +that we can have an +ellipse rotating like this? + +And that would be great. + +But this is sort of unnatural +because the harmonic oscillator + +does that. + +So if you wanted to do that, +you need an operator which + +is really, at every cycle of +the electromagnetic field, + +is when the light want +to sort of do this. + +No. + +Always push it back. + +And this is impractical. + +You need, really, an oscillator +which would completely + +change the quadrature components +of your harmonic oscillator + +in every single cycle of +the electromagnetic field. + +But sort of what homodyne +detection is, instead + +of now forcing the light to +stay aligned to sort of do + +this, which is +very unnatural, we + +allow the light +to freely evolve. + +But we have now an observer, +our local oscillator, + +which is rotating +synchronously with the ellipse. + +So we have a local oscillator +which is cosine omega t. + +It does, so to speak, exactly +what the ellipse is doing. + +So in that sense, +the local oscillator + +allows us, now, to +observe the ellipse always + +from its narrow side. + +Because the local oscillator +is [? cooperating ?]. + +But the mathematics is +pretty much the [? Fourier ?] + +transform. + +The mathematics is a +[? Fourier ?] transform. + +The physics is the physics +of a [INAUDIBLE] detector. + +OK, now the only question +remaining is, how do we mix? + +How do we get a +product of our signal + +and the strong local oscillator? + +In an old radio, it's +done by an element. + +Maybe a diode, which +is a nonlinear circuit. + +If you drive a nonlinear +element with two input sources, + +you get something which +involves the product of the two. + +OK, so the principal +of homodyne detection + +is now that we want to mix +light at the beam splitter. + +So the device which +does all that for us + +is, after using so many +words, I would say it's + +disgustingly simple. + +It's really a half [INAUDIBLE]. + +We talked about +beam splitters a lot + +here because beam +splitters perform + +wonderful unitary +transformations. + +And we'll exploit them +for many purposes. + +For the purpose of +this lecture, I simply + +assume that we have a +50-50 beam splitter. + +So, what I'm telling you +now about the beam splitter + +will be generalized. + +Either later today, or in +the lecture on Wednesday. + +So a beam splitter has two +input ports and output ports. + +We have light impinging +on the beam splitter. + +We call those modes a and b. + +And after the beam splitter, +we have two output modes. + +And let me call them a0 and b0. + +And what we measure is the +output of the beam splitter. + +So we have two photo detectors. + +And we measure the output. + +OK. + +The output modes, a +naught and b naught, + +are simply obtained by +taking the input modes + +and propagating them. + +We have two modes, a, b. + +You can say, what +goes vertically is a. + +Vertical is a. + +We call it a naught. + +Here, it's b. + +It becomes b naught. + +And what we have +to do is we have + +two transform the +operator a naught. + +Let me just make a comment. + +Sometimes in the +beam splitter, you + +want to think a quantum state +comes and is transformed. + +But instead of transforming +the state of a photon, + +I can also transform +the operator, + +which creates a photon. + +One is the Heisenberg picture. + +One is a Schrodinger picture. + +So right now, I'll use +the Heisenberg picture. + +I have two operators, a, b. + +Before the beam splitter is set, +I have two operators, a naught, + +b naught. + +Afterwards, I have +two other operators. + +I have operators a, b. + +Afterwards, i have operators +a naught, b naught. + +And, if you do the +time evolution, + +it's a unitary transformation. + +And for operators, we have +to multiply the operators + +from the left and +right hand side, + +with unitary operator, +u and u dagger. + +And we really talk +about the beam splitter + +in its full beauty +in a short while. + +It will be a special case +of what we discuss later. + +But I think it's pretty obvious +that a 50-50 beam splitters is + +simply creating two modes. + +One of the symmetric +combination. + +And one of the anti +symmetric combination. + +OK. + +So in our homodyne +detector, we are now + +measuring the number of +photons in the mode a naught. + +We measure with +the upper detector, + +the number of photons +in the mode b naught. + +But what we are then +doing is we run it + +through a different [INAUDIBLE]. + +We want to cancel +certain noises, + +as you will see in a moment. + +This is why we +obtain the difference + +signal, which we call I minus. + +So let's now calculate +what I minus is. + +Well, the number of photons +in the mode a naught + +is a naught dagger a naught. + +That's the operator for +the number of photons. + +We subtract b naught +dagger b naught. + +And, as you can +immediately see, is + +that it because of the +beam splitter, this + +is now involving a +product of a and b. + +ab dagger plus a dagger b. + +So in other words, +when you ask yourself, + +how can we-- remember, I said +we peak out the cosine omega t + +component by +multiplying our signal + +with the local oscillator. + +And you would say, +how do you multiply + +two modes of the +electromagnetic field? + +Well, just send it +to a beam splitter. + +In a beam splitter, you +create the sum of them. + +But then your photo detector +is square [INAUDIBLE] detector. + +You measure the electric +fields squared or you + +have to measure the +operator, a dagger a. + +And now, you get the [INAUDIBLE] +between ab dagger and a dagger + +b. + +So this is how we +multiply two operators. + +How we get a signal, which is +a proportional to a or a dagger + +times b or b dagger. + +By the way, if it wouldn't +take the difference, + +we get terms of aa +dagger bb dagger. + +Just the mode a or the +mode b by themselves. + +And we want to get rid of them. + +And by taking the difference +between the two photo + +detectors, those parts of +the signal are becoming mode. + +And are subtracted out. + +So therefore, this is +called balanced homodyne + +because we have the +balanced beam splitter. + +We measure to two signals. + +And then we take the +difference of the two signals. + +OK. + +There's one more +thing we have to add. + +And then we find we understand +the balanced homodyne + +detection. + +We want to explore it. + +That our mode b, +remember we want + +to measure mode a. a squeezed. + +a has quantum properties. +a has only single photons. + +And b is just a trick to +project out the cosine omega t. + +And we do that by choosing +for b a strong coherent state, + +described by a coherent +state parameter beta. + +Of course, whenever we have +a strong coherent state, + +that means that we +can replace b by beta, + +and b dagger by beta star. + +This is sort of +the classical field + +limit of a strong +coherent state. + +And now we can ask, what this +our different signal I minus? + +Well, the coherent state depends +on the phase angle theta. + +So it will be phase sensitive. + +It will depend on +the angle theta. + +But now there is one more thing. + +And that is, if you use a +stronger coherent state, + +of course both of our outputs +go up in proportion to beta. + +So therefore, we want +to go to a normalization + +by dividing by beta. + +So this is now our +normalized output. + +I'm looking at this. + +So this is our operator +for the signal I minus. + +And that is a. + +b has been replaced by, b dagger +has been replaced by b star. + +That gives us a times +e to the-- because + +of the complex +conjugation-- minus i + +theta plus a dagger times e +to the i theta divided by 2. + +So therefore, if we +choose the phase to be 0, + +we measure this +symmetric combination, + +a plus a dagger over 2. + +And this is-- just +comparing notes-- + +simply the a1 quadrature +operator divided by square root + +2. + +And if you put a phase shifter, +just a dispersive element, + +into the strong local +oscillator and shift + +the phase by pi over 2, by +delaying the light pulse + +by a quarter wavelength, what +we are now projecting out + +is the other +quadrature component. + +So therefore, using +the beam splitter + +and the local +oscillator, we can now + +measure the expectation +value for a1 and for a2. + +I've posted a few papers +on the website which + +show some of the pioneering +experiments where + +people did exactly that. + +So then, when they observed the +quadrature comportment, which + +was squeezed, they usually +did it for a squeezed vacuum, + +so a1 and a2 had 0 +expectation value. + +But the interesting part is, +how much noise was there? + +If you don't squeeze, you find +that your normalized noise + +simply corresponds to the +classical photon shot noise. + +But if you are +squeezed, you find + +that one quadrature +comportment has + +a smaller noise than shot noise. + +So [INAUDIBLE] photons +in your different signal. + +And your noise is less +than square root n. + +Where as in the +other quadrature, + +the component is larger. + +So you can look up +on the website papers + +where people slowly varied the +phase of the local oscillator. + +And you see, this +is shot noise, how + +the noise is below shot noise. + +Exceeds shot noise. + +It's below shot noise. + +And exceeds shot noise. + +And this was the first +evidence for the generation + +of squeezed light. + +Questions? + +OK. + +So we have discussed +the detection + +of squeezed light using +balanced homodyne detector. + +And balanced means that the +beam splitter was 50-50. + +So now we are ready to +discuss the unbalanced case. + +So let's get our +unbalanced beam splitter + +and, just for the +sake of the argument, + +let's say it has a really +good transmission of tt. + +So transmission +coefficient t squared + +tells you what fraction of +the power is transmitted. + +And let's just assume for +the sake of the argument, 99% + +are transmitted. + +So therefore, if we +start with our signal + +a, which may be +[INAUDIBLE] squeezed + +quantum state, number state. + +You name it. + +a naught is pretty +much the same as a. + +We haven't lost so much. + +But now we use our +local oscillator, + +which is very strong. + +Only a very small fraction +of it will be reflected. + +But we can always compensate +for the small reflection + +by making b even stronger. + +Let's see what we get. + +So the mode, a naught, +the output mode, + +is now the transmission +coefficient times a. + +a and a. + +The operators are amplitudes. + +So we have to use, if you +have a 99% beam splitter, + +we have to take the +square root of 0.99. + +This is the transmission +coefficient. + +And now we have the +transmission coefficient + +for the strong local +oscillator, which + +we will again approximate +by its eigenvalue. + +Coherent state eigenvalue. + +And the reflection coefficient +is 1 minus t squared. + +So if we make the approximation +that t is approximately 1, + +we can take it out +off the parenthesis. + +And we obtain that. + +If t is close to 1, +we can neglect it. + +And what we see now is +what we have obtained + +is actually the original +quantum state a. + +Or I should say. + +The operator. + +I'm in the Heisenberg picture. + +a is the mode +operator for the input + +of the unbalanced +homodyne detector. + +And what we have simply done is +we have displaced the operator. + +We have displaced +the mode operator a. + +And the displacement operator +has an [? argument ?] + +of 1 minus t squared beta. + +And this is a +Hermitian conjugate. + +1 minus t squared beta. + +So what I've shown you here +is that the local oscillator + +and the beam splitter is the +realization, or implementation, + +of the displacement operator. + +So in the limit that +t goes to unity, + +we are not losing anything +of out quantum state. + +But by reflecting +in the amplitude + +of a strong coherent state, we +simply take our quantum state, + +and we displace it in this +two dimensional plane. + +So that's what this beam +splitter does for us. + +Any questions? + +In the next few +classes, we really + +take advantage of +those elements. + +We know now that the +displacement operator is just + +a beam splitter. + +We know when we have +squeezed some light + +by using balanced +homodyne detection, + +we can just do measurement +of one quadrature component + +or the other. + +So what I hope for those of +you who haven't heard about it, + +what you take away +from that is that these + +are extremely simple elements. + +But by combining +them, we can really + +realize very sophisticated +schemes of quantum optics. + +To some extent, when I heard +about it for the first time, + +I think, the mathematics +look so fancy. + +I couldn't believe that such +simple elements can actually + +realize what those +operators describe. + +So I gave you the example for +the displacement operator. + +When I learned about +the beam splitter, + +and its underlying +physics, there + +was one thing which +really fascinated me. + +And this is the most simple +element you can think of. + +I mean, what is simpler +than a beam splitter? + +A beam splitter has two +inputs, two outputs. + +The simplest optical element +is just an attenuator. + +Put in a window +in your laser beam + +and you lose 4% of +your power preserves. + +Or put in just a little +bit of dirty optics + +and you lose a few percent. + +So what I want to +discuss with you now + +is, what really is an +attenuator quantum mechanically? + +Well if, classically, +the attenuator + +would do the following. + +An attenuator is a device +which has a transmission, which + +is a transmission +coefficient squared, + +which is smaller than unity. + +And, in a classical system, +if you have a coherent state, + +you would simply assume that the +coherent state gets multiplied + +by the transmission coefficient. + +In other words, that you +have your original state, + +described by this +phase, or alpha. + +And then, the action +of the attenuator + +would simply be to +scale everything down + +by a transmission +effect of alpha. + +So the picture you should +have is the following. + +You have a coherent state. + +It gets attenuated by the +transmission coefficient. + +But if there are fluctuations +about the coherent state, + +also the fluctuations +get attenuated. + +Because everything gets +attenuated by this attenuator. + +So if you look at that, you +should immediately say, no. + +This is quantum +mechanically forbidden. + +Because a coherent state with +a minimum uncertainty state, + +this shaded area cannot +be smaller than 1/2. + +But here it has become smaller. + +So what I've shown +to you here is + +it's a violation of +quantum mechanics. + +It would actually mean, let +me just give you the example. + +It would mean that if-- yeah. + +The coherent state +is quantum limited. + +And if you calculate what is +the fluctuations in the photo + +number, it's a shot noise. + +So just to give you sort of +simple, intuitive example, + +if you have 10,000 photons plus +minus 100, it's a shot noise. + +Square root n. + +If you could now attenuate +it by a factor of 100, + +and you would go from +10,000 plus minus 100, + +to 100 plus minus 1. + +That's much better +than the shot noise. + +I mean, this is what +I'm just telling you + +what a simpleminded +attenuator would do. + +And you would immediately say, +that's too good to be true. + +I cannot get sub +shot noise light. + +So what is wrong? + +Impossible. + +Not allowed. + +Well, we've just tried +to formulate something + +intuitively. + +And we have to be careful. + +Well, we know +already one way how + +we can attenuate an input beam. + +And maybe we should go back to +the situation and analyze it. + +We know what if we can attenuate +it with a beam splitter. + +And this beam splitter has a +transmission coefficient of t. + +And then we get our +transmitted coherent light. + +There is something +getting reflected. + +But now we realize that +this beam splitter is not + +just a device which +has one input. + +It has another input. + +And you may say, well, I don't +care about the other input. + +I don't want to use it. + +Well, if you don't +want to use the input, + +it has the vacuum state. + +So therefore, if you would +realize the attenuator + +with the beam splitter, it +would mean that, in addition, + +and this is what the math +really shows, in addition + +to the attenuated coherent +state, which mathematically + +is also attenuating +the fluctuations, + +you have to add something. + +Which is the +reflection coefficient + +times the vacuum state. + +Which is this. + +And if you now +correctly do the math, + +if you add the two +together, you find + +you get a coherent state which +has an amplitude of t alpha. + +But has the correct +[INAUDIBLE] fluctuation + +is again a minimum +uncertainty state. + +So the disk of your +attenuated state + +hasn't exactly the same area +as the unattenuated state. + +So I've shown you +the physical part. + +I have shown you the +graphical solution. + +The math is very simple. + +But I really want you +to do the math yourself. + +This is a new +homework problem we + +designed to illustrate +the physics. + +But what it tells +you is the following. + +If you take a neutral +density filter out + +of the lab [INAUDIBLE] and say, +this is not a beam splitter. + +This is an attenuator. + +Sorry. + +You cannot simply attenuate +a quantum mechanical mode. + +This is not a unitary +time evolution. + +What you attenuate [INAUDIBLE] +is, without you knowing it, + +it couples the electromagnetic +wave to whatever. + +To the heat path +of the [INAUDIBLE], + +which is in your attenuator. + +I don't even want +to describe it. + +But you're not +circumventing the limitation + +of the beam splitter. + +Whenever you attenuate, +whenever you have a laser beam, + +and it undergoes losses, +when you send a laser beam + +through the atmosphere, and +it undergoes some losses by, + +who knows, +[INAUDIBLE] scattering + +through the air or +something like this. + +That means you get an +attenuated coherent state. + +But you couple in the +fluctuations off the vacuum. + +And this establishes +shot noise now, + +at the lower level of intensity. + +So your attenuator is not +a single state device. + +Dissipation. + +Attenuation really +means you connect + +with other parts of +[INAUDIBLE] space. + +You cannot attenuate in a +small part [INAUDIBLE] space. + +This is impossible. + +This is not unitary +time evolution. + +So what I've just told you +has dramatic consequences + +for any form of non +classical, or squeezed, light. + +And that's the following. + +Most of you are +experimentalists. + +And you know that when you run +a laser at one or two watts, + +you send it through optics, and +shudders, and optical fibers. + +How much do you get at the +end of your experiment? + +Not even 50%. + +So, whenever you create +light, and then you + +want to do something, you +lose some of the light. + +And let's now assume that +you have done what was really + +a breakthrough in scientific +headlines within your lifetime. + +You have generated +squeezed light. + +And now we want to use +the squeezed light. + +Shine it on atoms and do +a precision measurement, + +which is better than the +standard quantum limit + +because you have +squeezed the ellipse. + +And you want to now exploit +the sharpness of the ellipse. + +What happens to your +aspect ratio of the ellipse + +when your beam is attenuated? + +So let me just discuss +it with you graphically. + +So let's assume we +have a squeezed state. + +And we send it through +an optical fiber. + +The result is you will +never send a squeezed state + +through an optical fiber. + +But I want you to realize that. + +So let's assume we have our +squeezed state, symbolized + +by that. + +Let's use some red +color for the state. + +And now, in the +time evolution, we + +have some [INAUDIBLE] +scattering. + +Some fiber absorption. + +But you know already, +the absorption + +is in reality a beam splitter, +which happens in the vacuum. + +So + +We have now some finite +transmission coefficients. + +And that would mean, +which is the bad news, + +that your ellipse gets shrunk. + +It shrinks. + +It shrinks by the +transmission factor t. + +But that's what I did bad. + +You lose some of your power. + +But the really bad thing +is that if I multiply it + +with the reflection coefficient, +you couple in the vacuum. + +Oops. + +I'm going to change to red. + +And, as a result, since +the noise in the vacuum + +is equal in both +quadrature components, + +you've worked so hard to squeeze +it, to make it asymmetric. + +But what you get now +is from your ellipse, + +you get something which is +much more egg shaped now. + +So in other words, you can +write it down with operators. + +But once you understand +what is going on, + +you immediately realize that +losses reduce the squeezing. + +And this is a challenge to +all the experiments using + +squeezed or non classical light. + +And you see how +the scaling works. + +If you have squeezed your +ellipse by a factor of 100, + +even 1% of the vacuum +will spoil your squeezing. + +So the more you have +squeezed, the more + +non-classical the light is-- +the more valuable it is. + +The more sensitive it is, +to even very small losses. + +Questions? + +OK, good. + +Now we have 10 more minutes. + +What I want to do now +is, I want to show you + +that the language +which we have used, + +the methods we have introduced, +can now be used for something + +which is really +cool-- teleportation. + +I want to show you how +balanced homodyne detection, + +quadrature measurement, and +displacement operator can + +be put together to +generalize is scheme which + +is a scheme for +teleporting quantum states. + +This is an application +of squeezing, homodyning, + +and all that. + +Teleportation of light. + +Let me just illustrate +what the problem is. + +I know we have only +10 minutes, and I've + +decided not to write down +all the math for you. + +I went, actually, to +the Wikipedia page, + +and corrected a few +mistakes in the equations + +and edited a few explanations. + +I think you can just sit +down and read it by yourself. + +What I want to +explain to you, here, + +is the physical concepts +behind teleportation, + +and you the crucial steps +to realize teleportation. + +So first, what is teleportation? + +Well, teleportation has +a sender and a received, + +which in quantum +information science + +are called Alice and Bob. + +Teleportation means Alice +has a quantum state, psi. + +And she wants to send this +quantum state, psi, to Bob. + +In other words, you have, +maybe, some squeezed light. + +You have something-- +a quantum state, + +psi-- which is interesting. + +And the question is, how can +Bob create an identical copy + +of this quantum +state, psi, that he + +can sort of [INAUDIBLE] +with the same quantum state. + +Before you appreciate +teleportation, + +you have to realize +what the problem is. + +The problem is, really, +in fundamental properties + +of quantum systems, +fundamental limitations-- what + +you can do with +a quantum system. + +First, I have to tell you +what is allowed, and what not. + +In this game, teleportation +means, of course, + +you will not take your atom and +your photons in the state psi, + +just propagate them to +Bob, and Bob has them. + +That's trivial. + +I can send any +quantum state to you + +by transmitting an atom +or a laser beam to you, + +and you have the same +quantum state I had earlier. + +This is not teleportation. + +This is trivial propagation. + +What is meant is that we don't +have a quantum channel-- I'm + +not allowed to send my +quantum state to you. + +But in teleportation, I can do +a measurement on the quantum + +state, call you up through +a classical communication + +channel, and tell you, the +result of my measurement + +is such and such. + +And then you would say, well, +if I have a spin system, + +and I measure spin up-- +I call you and say, + +my measurement was spin up, and +you create a spin up system. + +Isn't that teleportation? + +The answer is no, because +maybe the state I had + +was a superposition +of spin up and down. + +And what I measured +is only spin up. + +And by telling you +it's spin up, you + +would never create a +superposition state, + +you would just create +a spin up state. + +So the effect is, that if I +do a measurement on my quantum + +state, and report +my results to you, + +you have insufficient +information. + +Because a projective +measurement on a quantum + +state inevitably leads +to loss of information. + +A measurement on a +single quantum state + +does not create +enough information + +to recreate the quantum state. + +Of course, there is +an obvious solution. + +When we want to obtain +information about a quantum + +state, we often, in +quantum mechanics, + +have to do many measurements. + +And we can take a +spin state, we can + +measure what is +its x, what its y, + +what is the c +component of the spin. + +We can completely +characterize the spin state, + +and then we know +everything about it. + +But the problem is, we have +only one quantum state, + +and we can't do +repeated measurements. + +Then you would say, well, the +next thing is, why don't you + +just take your quantum +state and Xerox it, + +make many, many copies. + +And then you have +an ensemble, and you + +can take as many +measurements you want. + +You can do an x +measurement, p measurement. + +I mean, you can reconstruct +the complete wave function. + +You can measure with an x basis. + +You can measure with +a momentum basis. + +You can collect all +the information. + +But the problem is-- otherwise +the whole teleportation + +would not be an +issue at all-- there + +is the no-cloning theorem. + +You cannot duplicate +a quantum state. + +If you have an atom in a certain +quantum state and another atom, + +it is quantum-mechanically +forbidden-- + +there is no unitary +transformation, + +no way of creating a +situation that you have + +one unknown quantum +state, plus another atom, + +or another light beam, +and after some interaction + +you have two times the +same quantum state. + +You cannot clone. + +Therefore, based on all that, we +cannot clone the quantum state. + +We are only left +with the one copy + +of the quantum state, +which Alice has. + +Alice is not allowed +to send it to Bob. + +Maybe Bob is on the +other side of the ocean, + +or on another planet. + +All what Alice can do is, +she can do one measurement + +and tell Bob, this +is my measurement. + +So this is the problem +of teleportation. + +How is that possible? + +Well, the way how I put +it, it seems impossible. + +But there's a way out of it. + +Let me just write +down what I said. + +So the goal is now-- Alice +performs measurement, + +reports result to Bob. + +And now, Bob will recreate +the quantum state. + +What I've just said is, to +perform a single measurement + +is not enough information. + +So this is not enough. + +We need one more resource. + +And the resource, +which is now used + +to use quantum teleportation, +is that you take some entangled + +system, or-- and this why I talk +about it today-- or squeezed + +light. + +That's the same thing. + +It's a form of entanglement. + +I told you that when we +generate squeezed light + +with a parametric +down conversion, + +the parametric down conversion +takes a green photon + +and creates two identical +infrared photons. + +Until now, we have +discussed that + +those identical +infrared photons go + +into the same mode, +which is squeezed. + +But now, a slight +extension of this concept + +would mean, in parametric +down conversion, + +you squeeze something, but +one photon goes to Alice, + +one photon goes to Bob. + +So now, Alice and Bob have +an additional resource. + +They sort of own-- +each of them-- half + +of the two twin brothers, +which are the photons created + +in the parametric down +conversion process. + +And that will work. + +So the idea is the following. + +To create those twin +beams of photons + +is simply done with an +optical parametric oscillator. + +There is one extension, which +is described on the Wiki. + +I won't have time to +explain it to you. + +But it's a two-mode OPO. + +It puts the two identical +photons-- not in the same beam, + +as we did before, we had +the a dagger squared, + +a squared operator-- they +go into two different modes. + +You know the magic of +beam splitters by now. + +Now, two beams come out. + +One goes to Alice, +one goes to Bob. + +If Alice would take her input +state-- this unknown state + +which is handed to her +by Victor, somebody + +else who participates in +the game-- we know already, + +if Alice would +perform a measurement, + +the quantum state +would be destroyed. + +The result of the measurement-- +let's talk about spin-1/2-- + +would only be one +spin projection. + +It's not enough to +reproduce a state. + +But what she is doing +is, she uses, again, + +the magic of the beam splitter. + +So one of those +twin brother photons + +is now mixed with +the unknown quantum + +state at the beam splitter. + +And the output of +the beam splitter + +is now entering the +balanced homodyne detection, + +which we just discussed. + +The output of this beam +splitter-- and there + +are two outputs-- +both of them is now + +becoming part of a balanced +homodyne measurement. + +And you see the ingredients. + +So this, and this, +will be measured. + +The other input for +the balanced homodyne + +is a strong local oscillator. + +The phase of the +local oscillator + +is chosen, in one case, that you +measure the x or a 1 quadrature + +component, or the p +or the a 2 component. + +So now what Alice +has done is, by using + +this balanced +homodyning, she has-- + +with this local +oscillator-- has actually + +now performed two measurements. + +The quantum state is destroyed, +but here she gets an x value, + +and here she gets a p value. + +So how the magic works out. + +It's really just a few +lines of mathematics, now. + +These were sort of, you +know, twin brothers. + +But it wasn't clear +in which quantum + +state the twin brothers are. + +If you write it +down, and I can show + +you the formula in a moment, +these are twin brothers. + +But those twin brothers-- this +is Brother 1, this is Brother + +2-- are in sort of a +continuum of states. + +And when Alice this would +measure that this twin brother + +is in state big X, that would +be a projective measurement. + +And Bob's twin brother +would now, with certainty, + +also be in the state, X. + +So therefore, what happens +is, the measurement of x and p + +is now producing-- is now, +through the measurement + +process-- putting the other +photon, or the other beam, + +the other twin brother, into +a specific quantum state. + +And if you look for +few lines of math, + +the magic is that the quantum +state-- which is now here, + +with Bob-- turns out +to be a displaced copy + +of the original state. + +And the displacement +depends on x and p. + +So if Alice now tells Bob, +hey, I measured x and p, + +and Bob is now [INAUDIBLE] +his displacement operator-- + +remember, a +displacement operator is + +nothing else than an +unbalanced beam splitter, + +with a huge local +oscillator as an input. + +So if Bob is now setting up +his displacement operator, + +it makes a displacement +which depends on x and p. + +He can take this other twin +brother, shift it back, + +and he will exactly +regenerate the quantum + +state which Alice had. + +So this is, now, +how a quantum state + +can be transmitted +without having any quantum + +channel for transmission. + +You're not propagating +the quantum state. + +You use classical communication, +but the resource you use + +is some EPR pairs, +or squeezed light. + +It's a few lines +of equations, but I + +don't have time +to go through it. + +They're really +annotated in a way + +that I think it will be an +enjoyful reading for you. + +Any questions? + +Time is over. + +OK. + +A reminder for those who +came late-- this week + +we have three classes, +Monday, Wednesday, Friday. + +Have a good afternoon. \ No newline at end of file diff --git a/zm2VP0kHl1M.txt b/zm2VP0kHl1M.txt new file mode 100644 index 0000000000000000000000000000000000000000..35ca6fb0c6b395a2590f4cc125027d88d182f296 --- /dev/null +++ b/zm2VP0kHl1M.txt @@ -0,0 +1,9899 @@ +align:start position:0% + +all right so what we're going to do + + align:start position:0% +all right so what we're going to do + + + align:start position:0% +all right so what we're going to do +today is continue our discussion of + + align:start position:0% +today is continue our discussion of + + + align:start position:0% +today is continue our discussion of +modularity and how you hook software + + align:start position:0% +modularity and how you hook software + + + align:start position:0% +modularity and how you hook software +modules up together and what we did the + + align:start position:0% +modules up together and what we did the + + + align:start position:0% +modules up together and what we did the +last time was talked about how you share + + align:start position:0% +last time was talked about how you share + + + align:start position:0% +last time was talked about how you share +data between programs and between users + + align:start position:0% +data between programs and between users + + + align:start position:0% +data between programs and between users +and we went through the design of the + + align:start position:0% +and we went through the design of the + + + align:start position:0% +and we went through the design of the +UNIX file system or at least a + + align:start position:0% +UNIX file system or at least a + + + align:start position:0% +UNIX file system or at least a +particular aspect of the UNIX file + + align:start position:0% +particular aspect of the UNIX file + + + align:start position:0% +particular aspect of the UNIX file +system where we talked about how we + + align:start position:0% +system where we talked about how we + + + align:start position:0% +system where we talked about how we +built a file system out of layers and + + align:start position:0% +built a file system out of layers and + + + align:start position:0% +built a file system out of layers and +layers and each layer was essentially + + align:start position:0% +layers and each layer was essentially + + + align:start position:0% +layers and each layer was essentially +doing name resolution on in order for us + + align:start position:0% +doing name resolution on in order for us + + + align:start position:0% +doing name resolution on in order for us +to take a UNIX path name and eventually + + align:start position:0% +to take a UNIX path name and eventually + + + align:start position:0% +to take a UNIX path name and eventually +get the data blocks corresponding to the + + align:start position:0% +get the data blocks corresponding to the + + + align:start position:0% +get the data blocks corresponding to the +data in that file what we're going to do + + align:start position:0% +data in that file what we're going to do + + + align:start position:0% +data in that file what we're going to do +today is to move away a little bit from + + align:start position:0% +today is to move away a little bit from + + + align:start position:0% +today is to move away a little bit from +the memory abstraction which is what we + + align:start position:0% +the memory abstraction which is what we + + + align:start position:0% +the memory abstraction which is what we +spent our time on the last time and + + align:start position:0% +spent our time on the last time and + + + align:start position:0% +spent our time on the last time and +start talking about the second + + align:start position:0% +start talking about the second + + + align:start position:0% +start talking about the second +abstraction the interpreter abstraction + + align:start position:0% +abstraction the interpreter abstraction + + + align:start position:0% +abstraction the interpreter abstraction +and we're going to do that in the + + align:start position:0% +and we're going to do that in the + + + align:start position:0% +and we're going to do that in the +context of software libraries and + + align:start position:0% +context of software libraries and + + + align:start position:0% +context of software libraries and +basically + + align:start position:0% +basically + + + align:start position:0% +basically +understand how software + + align:start position:0% +understand how software + + + align:start position:0% +understand how software +libraries are put together and how you + + align:start position:0% +libraries are put together and how you + + + align:start position:0% +libraries are put together and how you +can build large software programs out of + + align:start position:0% +can build large software programs out of + + + align:start position:0% +can build large software programs out of +individual software modules that get + + align:start position:0% +individual software modules that get + + + align:start position:0% +individual software modules that get +hooked together so + + align:start position:0% +hooked together so + + + align:start position:0% +hooked together so +that's the plan for today and in + + align:start position:0% +that's the plan for today and in + + + align:start position:0% +that's the plan for today and in +addition to seeing the actual mechanism + + align:start position:0% +addition to seeing the actual mechanism + + + align:start position:0% +addition to seeing the actual mechanism +for how you take all these modules in + + align:start position:0% +for how you take all these modules in + + + align:start position:0% +for how you take all these modules in +the form of libraries and other software + + align:start position:0% +the form of libraries and other software + + + align:start position:0% +the form of libraries and other software +pieces hook them up together what we're + + align:start position:0% +pieces hook them up together what we're + + + align:start position:0% +pieces hook them up together what we're +really going to focus on is the + + align:start position:0% +really going to focus on is the + + + align:start position:0% +really going to focus on is the +mechanism by which all these different + + align:start position:0% +mechanism by which all these different + + + align:start position:0% +mechanism by which all these different +modules actually run on your computer ok + + align:start position:0% +modules actually run on your computer ok + + + align:start position:0% +modules actually run on your computer ok +so it's going to involve a fair amount + + align:start position:0% +so it's going to involve a fair amount + + + align:start position:0% +so it's going to involve a fair amount +of mechanism going down to the lowest + + align:start position:0% +of mechanism going down to the lowest + + + align:start position:0% +of mechanism going down to the lowest +layer until you actually have something + + align:start position:0% +layer until you actually have something + + + align:start position:0% +layer until you actually have something +that's a single executable file that + + align:start position:0% +that's a single executable file that + + + align:start position:0% +that's a single executable file that +runs on your computer and then what + + align:start position:0% +runs on your computer and then what + + + align:start position:0% +runs on your computer and then what +we're going to do is to step back and + + align:start position:0% +we're going to do is to step back and + + + align:start position:0% +we're going to do is to step back and +think about the kind of modularity that + + align:start position:0% +think about the kind of modularity that + + + align:start position:0% +think about the kind of modularity that +we modularity that we will have gotten + + align:start position:0% +we modularity that we will have gotten + + + align:start position:0% +we modularity that we will have gotten +from this approach and that's a kind of + + align:start position:0% +from this approach and that's a kind of + + + align:start position:0% +from this approach and that's a kind of +modularity that we're + + align:start position:0% +modularity that we're + + + align:start position:0% +modularity that we're +going to call soft modularity so + + align:start position:0% + + + + align:start position:0% + +that's the plan for today and you'll see + + align:start position:0% +that's the plan for today and you'll see + + + align:start position:0% +that's the plan for today and you'll see +why this is called soft modularity and + + align:start position:0% +why this is called soft modularity and + + + align:start position:0% +why this is called soft modularity and +has to do with arm the way in which + + align:start position:0% +has to do with arm the way in which + + + align:start position:0% +has to do with arm the way in which +propagation of faults occurs and in + + align:start position:0% +propagation of faults occurs and in + + + align:start position:0% +propagation of faults occurs and in +particular the kind of modularity with + + align:start position:0% +particular the kind of modularity with + + + align:start position:0% +particular the kind of modularity with +libraries we're going to discuss today + + align:start position:0% +libraries we're going to discuss today + + + align:start position:0% +libraries we're going to discuss today +has the property that a problem + + align:start position:0% +has the property that a problem + + + align:start position:0% +has the property that a problem +in one module for example an infinite + + align:start position:0% +in one module for example an infinite + + + align:start position:0% +in one module for example an infinite +loop or a crash in one module will turn + + align:start position:0% +loop or a crash in one module will turn + + + align:start position:0% +loop or a crash in one module will turn +out to affect the whole program the + + align:start position:0% +out to affect the whole program the + + + align:start position:0% +out to affect the whole program the +whole thing will come crumbling down + + align:start position:0% +whole thing will come crumbling down + + + align:start position:0% +whole thing will come crumbling down +okay that's why it's going to be called + + align:start position:0% +okay that's why it's going to be called + + + align:start position:0% +okay that's why it's going to be called +soft modularity of course you know we + + align:start position:0% +soft modularity of course you know we + + + align:start position:0% +soft modularity of course you know we +don't like that kind of modularity + + align:start position:0% +don't like that kind of modularity + + + align:start position:0% +don't like that kind of modularity +although it is useful to have soft + + align:start position:0% +although it is useful to have soft + + + align:start position:0% +although it is useful to have soft +modularity so the next three lectures + + align:start position:0% +modularity so the next three lectures + + + align:start position:0% +modularity so the next three lectures +after today we're going to talk about + + align:start position:0% +after today we're going to talk about + + + align:start position:0% +after today we're going to talk about +hardening the soft modularity using a + + align:start position:0% +hardening the soft modularity using a + + + align:start position:0% +hardening the soft modularity using a +variety of different techniques so + + align:start position:0% +variety of different techniques so + + + align:start position:0% +variety of different techniques so +that's the plan for the next three to + + align:start position:0% +that's the plan for the next three to + + + align:start position:0% +that's the plan for the next three to +four lectures okay + + align:start position:0% +four lectures okay + + + align:start position:0% +four lectures okay +so let's take some examples or to start + + align:start position:0% +so let's take some examples or to start + + + align:start position:0% +so let's take some examples or to start +with or where you end up using these + + align:start position:0% +with or where you end up using these + + + align:start position:0% +with or where you end up using these +modules these software modules to build + + align:start position:0% +modules these software modules to build + + + align:start position:0% +modules these software modules to build +bigger software systems and the first + + align:start position:0% +bigger software systems and the first + + + align:start position:0% +bigger software systems and the first +one is actually what you see in a + + align:start position:0% +one is actually what you see in a + + + align:start position:0% +one is actually what you see in a +programming language when you use C or + + align:start position:0% +programming language when you use C or + + + align:start position:0% +programming language when you use C or +C++ arm or Java or Perl + + align:start position:0% +C++ arm or Java or Perl + + + align:start position:0% +C++ arm or Java or Perl +or any of these programs that you're + + align:start position:0% +or any of these programs that you're + + + align:start position:0% +or any of these programs that you're +familiar with or you end up actually + + align:start position:0% +familiar with or you end up actually + + + align:start position:0% +familiar with or you end up actually +building large programs out of taking + + align:start position:0% +building large programs out of taking + + + align:start position:0% +building large programs out of taking +lots of little programs in usually + + align:start position:0% +lots of little programs in usually + + + align:start position:0% +lots of little programs in usually +programmed in different files and + + align:start position:0% +programmed in different files and + + + align:start position:0% +programmed in different files and +running a compiler on it and it'll turn + + align:start position:0% +running a compiler on it and it'll turn + + + align:start position:0% +running a compiler on it and it'll turn +out to require other system software to + + align:start position:0% +out to require other system software to + + + align:start position:0% +out to require other system software to +take our programs that are written in + + align:start position:0% +take our programs that are written in + + + align:start position:0% +take our programs that are written in +different modules and hook them all up + + align:start position:0% +different modules and hook them all up + + + align:start position:0% +different modules and hook them all up +together into a bigger program um and + + align:start position:0% +together into a bigger program um and + + + align:start position:0% +together into a bigger program um and +this is actually going to be we're going + + align:start position:0% +this is actually going to be we're going + + + align:start position:0% +this is actually going to be we're going +to run today with examples from the C or + + align:start position:0% +to run today with examples from the C or + + + align:start position:0% +to run today with examples from the C or +C++ programming language to find out how + + align:start position:0% +C++ programming language to find out how + + + align:start position:0% +C++ programming language to find out how +we build C modules together but by no + + align:start position:0% +we build C modules together but by no + + + align:start position:0% +we build C modules together but by no +means are we restricted to these + + align:start position:0% +means are we restricted to these + + + align:start position:0% +means are we restricted to these +programming languages in fact almost + + align:start position:0% +programming languages in fact almost + + + align:start position:0% +programming languages in fact almost +there's a lot of different examples + + align:start position:0% +there's a lot of different examples + + + align:start position:0% +there's a lot of different examples +database systems provide a great example + + align:start position:0% +database systems provide a great example + + + align:start position:0% +database systems provide a great example +of modularity so + + align:start position:0% + + + + align:start position:0% + +if you take a system like you know you + + align:start position:0% +if you take a system like you know you + + + align:start position:0% +if you take a system like you know you +might have heard of article or Sybase or + + align:start position:0% +might have heard of article or Sybase or + + + align:start position:0% +might have heard of article or Sybase or +any of the IBM's db2 all of these things + + align:start position:0% +any of the IBM's db2 all of these things + + + align:start position:0% +any of the IBM's db2 all of these things +are fairly complicated pieces of + + align:start position:0% +are fairly complicated pieces of + + + align:start position:0% +are fairly complicated pieces of +software but what they invariably allow + + align:start position:0% +software but what they invariably allow + + + align:start position:0% +software but what they invariably allow +you to do is to put in your own software + + align:start position:0% +you to do is to put in your own software + + + align:start position:0% +you to do is to put in your own software +your own code that will run as part of + + align:start position:0% +your own code that will run as part of + + + align:start position:0% +your own code that will run as part of +the database system so if you for + + align:start position:0% +the database system so if you for + + + align:start position:0% +the database system so if you for +example come up with arm you know + + align:start position:0% +example come up with arm you know + + + align:start position:0% +example come up with arm you know +normally databases allow you to run + + align:start position:0% +normally databases allow you to run + + + align:start position:0% +normally databases allow you to run +queries on tables of data but we'll + + align:start position:0% + + + + align:start position:0% + +be back after these messages okay so + + align:start position:0% +be back after these messages okay so + + + align:start position:0% +be back after these messages okay so +every database system allows you to + + align:start position:0% +every database system allows you to + + + align:start position:0% +every database system allows you to +upload modules into it that run as part + + align:start position:0% +upload modules into it that run as part + + + align:start position:0% +upload modules into it that run as part +of the database system so if you come up + + align:start position:0% +of the database system so if you come up + + + align:start position:0% +of the database system so if you come up +with a different kind of data type for + + align:start position:0% +with a different kind of data type for + + + align:start position:0% +with a different kind of data type for +example or some geometric data type on + + align:start position:0% +example or some geometric data type on + + + align:start position:0% +example or some geometric data type on +which you want to ask whether arm you + + align:start position:0% +which you want to ask whether arm you + + + align:start position:0% +which you want to ask whether arm you +know there's a bunch of points inside a + + align:start position:0% +know there's a bunch of points inside a + + + align:start position:0% +know there's a bunch of points inside a +polygon a regular database based system + + align:start position:0% +polygon a regular database based system + + + align:start position:0% +polygon a regular database based system +won't actually support that but what you + + align:start position:0% +won't actually support that but what you + + + align:start position:0% +won't actually support that but what you +can do is write code for that and upload + + align:start position:0% +can do is write code for that and upload + + + align:start position:0% +can do is write code for that and upload +it and run it as a module in a database + + align:start position:0% +it and run it as a module in a database + + + align:start position:0% +it and run it as a module in a database +system another example a common example + + align:start position:0% +system another example a common example + + + align:start position:0% +system another example a common example +these days are web servers or + + align:start position:0% +these days are web servers or + + + align:start position:0% +these days are web servers or +particularly something like Apache where + + align:start position:0% + + + + align:start position:0% + +you can actually include as part of + + align:start position:0% +you can actually include as part of + + + align:start position:0% +you can actually include as part of +patchy when you run it a bunch of + + align:start position:0% +patchy when you run it a bunch of + + + align:start position:0% +patchy when you run it a bunch of +different modules for doing a variety of + + align:start position:0% +different modules for doing a variety of + + + align:start position:0% +different modules for doing a variety of +new functions that weren't previously + + align:start position:0% +new functions that weren't previously + + + align:start position:0% +new functions that weren't previously +running and all of these different kinds + + align:start position:0% +running and all of these different kinds + + + align:start position:0% +running and all of these different kinds +of systems will turn out to use + + align:start position:0% +of systems will turn out to use + + + align:start position:0% +of systems will turn out to use +essentially variants of the same basic + + align:start position:0% +essentially variants of the same basic + + + align:start position:0% +essentially variants of the same basic +idea in terms of solving the problem of + + align:start position:0% +idea in terms of solving the problem of + + + align:start position:0% +idea in terms of solving the problem of +taking these different pieces they've + + align:start position:0% +taking these different pieces they've + + + align:start position:0% +taking these different pieces they've +different modules together and composing + + align:start position:0% +different modules together and composing + + + align:start position:0% +different modules together and composing +a single large program that you can + + align:start position:0% +a single large program that you can + + + align:start position:0% +a single large program that you can +execute on your computer so + + align:start position:0% +execute on your computer so + + + align:start position:0% +execute on your computer so +what we're going to do today is arm + + align:start position:0% +what we're going to do today is arm + + + align:start position:0% +what we're going to do today is arm +discuss this + + align:start position:0% +discuss this + + + align:start position:0% +discuss this +method this kind of doing this way of + + align:start position:0% +method this kind of doing this way of + + + align:start position:0% +method this kind of doing this way of +doing modularity in the context of a + + align:start position:0% +doing modularity in the context of a + + + align:start position:0% +doing modularity in the context of a +particular example it's easiest to do + + align:start position:0% +particular example it's easiest to do + + + align:start position:0% +particular example it's easiest to do +this with an example and then we'll step + + align:start position:0% +this with an example and then we'll step + + + align:start position:0% +this with an example and then we'll step +back and talk about the general + + align:start position:0% +back and talk about the general + + + align:start position:0% +back and talk about the general +principles so we're going to focus on um + + align:start position:0% +principles so we're going to focus on um + + + align:start position:0% +principles so we're going to focus on um +the Linux operating system running the + + align:start position:0% +the Linux operating system running the + + + align:start position:0% +the Linux operating system running the +new tools and in particular we're going + + align:start position:0% +new tools and in particular we're going + + + align:start position:0% +new tools and in particular we're going +to focus on how you do this in a + + align:start position:0% +to focus on how you do this in a + + + align:start position:0% +to focus on how you do this in a +language like C or C++ and so most of + + align:start position:0% +language like C or C++ and so most of + + + align:start position:0% +language like C or C++ and so most of +you are probably familiar with some of + + align:start position:0% +you are probably familiar with some of + + + align:start position:0% +you are probably familiar with some of +the tools that you use to build programs + + align:start position:0% +the tools that you use to build programs + + + align:start position:0% +the tools that you use to build programs +in new and Linux and we're going to + + align:start position:0% +in new and Linux and we're going to + + + align:start position:0% +in new and Linux and we're going to +speak um use a compiler called GCC that + + align:start position:0% +speak um use a compiler called GCC that + + + align:start position:0% +speak um use a compiler called GCC that +will turn out to use some other pieces + + align:start position:0% +will turn out to use some other pieces + + + align:start position:0% +will turn out to use some other pieces +of software to build our modular + + align:start position:0% +of software to build our modular + + + align:start position:0% +of software to build our modular +programs that's kind of what we're going + + align:start position:0% +programs that's kind of what we're going + + + align:start position:0% +programs that's kind of what we're going +to start with and the basic approach in + + align:start position:0% +to start with and the basic approach in + + + align:start position:0% +to start with and the basic approach in +terms of how these modules are going to + + align:start position:0% +terms of how these modules are going to + + + align:start position:0% +terms of how these modules are going to +be written is um if you want to write a + + align:start position:0% +be written is um if you want to write a + + + align:start position:0% +be written is um if you want to write a +program you typically design what you + + align:start position:0% +program you typically design what you + + + align:start position:0% +program you typically design what you +want to do design the system and then + + align:start position:0% +want to do design the system and then + + + align:start position:0% +want to do design the system and then +decide on how you decompose the + + align:start position:0% +decide on how you decompose the + + + align:start position:0% +decide on how you decompose the +functionality of your system into a + + align:start position:0% +functionality of your system into a + + + align:start position:0% +functionality of your system into a +bunch of different modules and typically + + align:start position:0% +bunch of different modules and typically + + + align:start position:0% +bunch of different modules and typically +you write one or more files for each + + align:start position:0% +you write one or more files for each + + + align:start position:0% +you write one or more files for each +module in system and then you need a way + + align:start position:0% +module in system and then you need a way + + + align:start position:0% +module in system and then you need a way +to bring all these modules these + + align:start position:0% +to bring all these modules these + + + align:start position:0% +to bring all these modules these +different files together to build a + + align:start position:0% +different files together to build a + + + align:start position:0% +different files together to build a +bigger program and when you run GCC in + + align:start position:0% +bigger program and when you run GCC in + + + align:start position:0% +bigger program and when you run GCC in +particular onam dot o file the modules + + align:start position:0% +particular onam dot o file the modules + + + align:start position:0% +particular onam dot o file the modules +themselves once you compile a c file as + + align:start position:0% +themselves once you compile a c file as + + + align:start position:0% +themselves once you compile a c file as +you know you produce an object file um + + align:start position:0% +you know you produce an object file um + + + align:start position:0% +you know you produce an object file um +you know some with a name like file dot + + align:start position:0% +you know some with a name like file dot + + + align:start position:0% +you know some with a name like file dot +o and that + + align:start position:0% +o and that + + + align:start position:0% +o and that +actually contains in it that's a that's + + align:start position:0% +actually contains in it that's a that's + + + align:start position:0% +actually contains in it that's a that's +an object file that with some more work + + align:start position:0% +an object file that with some more work + + + align:start position:0% +an object file that with some more work +you can arrange to run on your on your + + align:start position:0% +you can arrange to run on your on your + + + align:start position:0% +you can arrange to run on your on your +computer and what we going to do today + + align:start position:0% +computer and what we going to do today + + + align:start position:0% +computer and what we going to do today +is figure out how when you have a large + + align:start position:0% +is figure out how when you have a large + + + align:start position:0% +is figure out how when you have a large +set a large number of object files and + + align:start position:0% +set a large number of object files and + + + align:start position:0% +set a large number of object files and +it'll also turn out we'll talk about + + align:start position:0% +it'll also turn out we'll talk about + + + align:start position:0% +it'll also turn out we'll talk about +something called a library which is a + + align:start position:0% +something called a library which is a + + + align:start position:0% +something called a library which is a +collection of object files put into a + + align:start position:0% +collection of object files put into a + + + align:start position:0% +collection of object files put into a +single archive how you can take those + + align:start position:0% +single archive how you can take those + + + align:start position:0% +single archive how you can take those +object files and produce an executable + + align:start position:0% +object files and produce an executable + + + align:start position:0% +object files and produce an executable +that will that will run so let me + + align:start position:0% +that will that will run so let me + + + align:start position:0% +that will that will run so let me +actually this works let me show you with + + align:start position:0% +actually this works let me show you with + + + align:start position:0% +actually this works let me show you with +an example what we're going to be + + align:start position:0% +an example what we're going to be + + + align:start position:0% +an example what we're going to be +talking about so I have two little files + + align:start position:0% +talking about so I have two little files + + + align:start position:0% +talking about so I have two little files +for a + + align:start position:0% + + + + align:start position:0% + +little trivial program I don't know if + + align:start position:0% +little trivial program I don't know if + + + align:start position:0% +little trivial program I don't know if +this is visible but okay + + align:start position:0% + + + + align:start position:0% + +so all this is doing is computing the + + align:start position:0% +so all this is doing is computing the + + + align:start position:0% +so all this is doing is computing the +square of a number and um it uses here a + + align:start position:0% +square of a number and um it uses here a + + + align:start position:0% +square of a number and um it uses here a +you know so this is a very trivial + + align:start position:0% +you know so this is a very trivial + + + align:start position:0% +you know so this is a very trivial +program it defines a few variables and + + align:start position:0% +program it defines a few variables and + + + align:start position:0% +program it defines a few variables and +then just calls a module a function + + align:start position:0% +then just calls a module a function + + + align:start position:0% +then just calls a module a function +called sqr which isn't actually in this + + align:start position:0% +called sqr which isn't actually in this + + + align:start position:0% +called sqr which isn't actually in this +file it's in a separate file but one + + align:start position:0% +file it's in a separate file but one + + + align:start position:0% +file it's in a separate file but one +thing you can do is drawn GCC - C which + + align:start position:0% +thing you can do is drawn GCC - C which + + + align:start position:0% +thing you can do is drawn GCC - C which +just tells it to produce the object file + + align:start position:0% +just tells it to produce the object file + + + align:start position:0% +just tells it to produce the object file +and um + + align:start position:0% +and um + + + align:start position:0% +and um +there's a program called object dump + + align:start position:0% +there's a program called object dump + + + align:start position:0% +there's a program called object dump +which is a useful program if you want to + + align:start position:0% +which is a useful program if you want to + + + align:start position:0% +which is a useful program if you want to +see what's inside your object file it's + + align:start position:0% +see what's inside your object file it's + + + align:start position:0% +see what's inside your object file it's +a binary file so you're not going to be + + align:start position:0% +a binary file so you're not going to be + + + align:start position:0% +a binary file so you're not going to be +able to hack it but you could run it + + align:start position:0% +able to hack it but you could run it + + + align:start position:0% +able to hack it but you could run it +with we've + + align:start position:0% + + + + align:start position:0% + +already reached the bottom alright okay + + align:start position:0% + + + + align:start position:0% + +so the + + align:start position:0% +so the + + + align:start position:0% +so the +part to worry about for the moment are + + align:start position:0% +part to worry about for the moment are + + + align:start position:0% +part to worry about for the moment are +shown in the last three lines that you + + align:start position:0% +shown in the last three lines that you + + + align:start position:0% +shown in the last three lines that you +could see here are starting main sqr and + + align:start position:0% +could see here are starting main sqr and + + + align:start position:0% +could see here are starting main sqr and +printf and those are the three functions + + align:start position:0% +printf and those are the three functions + + + align:start position:0% +printf and those are the three functions +that are being invoked by the program I + + align:start position:0% +that are being invoked by the program I + + + align:start position:0% +that are being invoked by the program I +showed you and you can see for sqr and + + align:start position:0% +showed you and you can see for sqr and + + + align:start position:0% +showed you and you can see for sqr and +printf arm this object file doesn't + + align:start position:0% +printf arm this object file doesn't + + + align:start position:0% +printf arm this object file doesn't +actually know where it is or where it's + + align:start position:0% +actually know where it is or where it's + + + align:start position:0% +actually know where it is or where it's +definition is and that's why you see und + + align:start position:0% +definition is and that's why you see und + + + align:start position:0% +definition is and that's why you see und +for undefined and part + + align:start position:0% +for undefined and part + + + align:start position:0% +for undefined and part +of what we're going to figure out today + + align:start position:0% +of what we're going to figure out today + + + align:start position:0% +of what we're going to figure out today +is how we can find out where those other + + align:start position:0% +is how we can find out where those other + + + align:start position:0% +is how we can find out where those other +modules are defined and hook up all of + + align:start position:0% +modules are defined and hook up all of + + + align:start position:0% +modules are defined and hook up all of +those different modules together to + + align:start position:0% +those different modules together to + + + align:start position:0% +those different modules together to +build a program that will actually run + + align:start position:0% +build a program that will actually run + + + align:start position:0% +build a program that will actually run +to do what we want it to do so + + align:start position:0% + + + + align:start position:0% + +the other thing here is Square dot C + + align:start position:0% +the other thing here is Square dot C + + + align:start position:0% +the other thing here is Square dot C +which does the obvious thing of just + + align:start position:0% +which does the obvious thing of just + + + align:start position:0% +which does the obvious thing of just +multiplying two numbers and you could do + + align:start position:0% +multiplying two numbers and you could do + + + align:start position:0% +multiplying two numbers and you could do +the same thing with a square + + align:start position:0% +the same thing with a square + + + align:start position:0% +the same thing with a square +dot C + + align:start position:0% +dot C + + + align:start position:0% +dot C +so I have a little thing called show + + align:start position:0% +so I have a little thing called show + + + align:start position:0% +so I have a little thing called show +object which is just an alias project + + align:start position:0% +object which is just an alias project + + + align:start position:0% +object which is just an alias project +dump and + + align:start position:0% + + + + align:start position:0% + +you + + align:start position:0% +you + + + align:start position:0% +you +can see here that there aren't actually + + align:start position:0% +can see here that there aren't actually + + + align:start position:0% +can see here that there aren't actually +any undefined symbols or undefined + + align:start position:0% +any undefined symbols or undefined + + + align:start position:0% +any undefined symbols or undefined +functions because choir in turn didn't + + align:start position:0% +functions because choir in turn didn't + + + align:start position:0% +functions because choir in turn didn't +invoke anything that was outside or in + + align:start position:0% +invoke anything that was outside or in + + + align:start position:0% +invoke anything that was outside or in +defined somewhere else and are + + align:start position:0% +defined somewhere else and are + + + align:start position:0% +defined somewhere else and are +underneath here you see the actual + + align:start position:0% +underneath here you see the actual + + + align:start position:0% +underneath here you see the actual +disassembled assembler code for on this + + align:start position:0% +disassembled assembler code for on this + + + align:start position:0% +disassembled assembler code for on this +machine text so going back to m + + align:start position:0% +machine text so going back to m + + + align:start position:0% +machine text so going back to m +dot o I just want to draw your attention + + align:start position:0% +dot o I just want to draw your attention + + + align:start position:0% +dot o I just want to draw your attention +to a couple of things yeah + + align:start position:0% +to a couple of things yeah + + + align:start position:0% +to a couple of things yeah +shows + + align:start position:0% + + + + align:start position:0% + +of fine on my screen I know how all + + align:start position:0% + + + + align:start position:0% + +right good arm okay + + align:start position:0% + + + + align:start position:0% + +so there's a few sections to this object + + align:start position:0% +so there's a few sections to this object + + + align:start position:0% +so there's a few sections to this object +file here arm and it's + + align:start position:0% +file here arm and it's + + + align:start position:0% +file here arm and it's +important to understand a little bit how + + align:start position:0% +important to understand a little bit how + + + align:start position:0% +important to understand a little bit how +an object file is laid out it has in it + + align:start position:0% +an object file is laid out it has in it + + + align:start position:0% +an object file is laid out it has in it +a few different sections as I as I + + align:start position:0% +a few different sections as I as I + + + align:start position:0% +a few different sections as I as I +mentioned one of the sections is called + + align:start position:0% +mentioned one of the sections is called + + + align:start position:0% +mentioned one of the sections is called +the text section the + + align:start position:0% +the text section the + + + align:start position:0% +the text section the +text section basically contains the + + align:start position:0% +text section basically contains the + + + align:start position:0% +text section basically contains the +machine code its arm whatever I mean + + align:start position:0% +machine code its arm whatever I mean + + + align:start position:0% +machine code its arm whatever I mean +ideally once you hook all these modules + + align:start position:0% +ideally once you hook all these modules + + + align:start position:0% +ideally once you hook all these modules +up together that machine code will + + align:start position:0% +up together that machine code will + + + align:start position:0% +up together that machine code will +actually just run on your computer it + + align:start position:0% +actually just run on your computer it + + + align:start position:0% +actually just run on your computer it +also has a section I think you can see + + align:start position:0% +also has a section I think you can see + + + align:start position:0% +also has a section I think you can see +it up there called auto data that's the + + align:start position:0% +it up there called auto data that's the + + + align:start position:0% +it up there called auto data that's the +second section that stands for read-only + + align:start position:0% +second section that stands for read-only + + + align:start position:0% +second section that stands for read-only +data and one + + align:start position:0% +data and one + + + align:start position:0% +data and one +of the things I had here in that program + + align:start position:0% +of the things I had here in that program + + + align:start position:0% +of the things I had here in that program +was something that said printf with a + + align:start position:0% +was something that said printf with a + + + align:start position:0% +was something that said printf with a +string inside and that string is + + align:start position:0% +string inside and that string is + + + align:start position:0% +string inside and that string is +read-only data I mean you don't want the + + align:start position:0% +read-only data I mean you don't want the + + + align:start position:0% +read-only data I mean you don't want the +probe the program doesn't actually + + align:start position:0% +probe the program doesn't actually + + + align:start position:0% +probe the program doesn't actually +modify it and that's the kind of thing + + align:start position:0% +modify it and that's the kind of thing + + + align:start position:0% +modify it and that's the kind of thing +you can see it on the right there's a + + align:start position:0% +you can see it on the right there's a + + + align:start position:0% +you can see it on the right there's a +comment that the square of something is + + align:start position:0% +comment that the square of something is + + + align:start position:0% +comment that the square of something is +something and that's an example of + + align:start position:0% +something and that's an example of + + + align:start position:0% +something and that's an example of +read-only data and then it has a section + + align:start position:0% +read-only data and then it has a section + + + align:start position:0% +read-only data and then it has a section +for data which really corresponds to the + + align:start position:0% +for data which really corresponds to the + + + align:start position:0% +for data which really corresponds to the +global variables used in the program arm + + align:start position:0% +global variables used in the program arm + + + align:start position:0% +global variables used in the program arm +and for those of you who remember 6.4 + + align:start position:0% +and for those of you who remember 6.4 + + + align:start position:0% +and for those of you who remember 6.4 +and if not we'll talk about this next + + align:start position:0% +and if not we'll talk about this next + + + align:start position:0% +and if not we'll talk about this next +time or the local variables in your + + align:start position:0% +time or the local variables in your + + + align:start position:0% +time or the local variables in your +modules are not actually in the data + + align:start position:0% +modules are not actually in the data + + + align:start position:0% +modules are not actually in the data +section they're typically on the stack + + align:start position:0% +section they're typically on the stack + + + align:start position:0% +section they're typically on the stack +so we're not going to worry about that + + align:start position:0% +so we're not going to worry about that + + + align:start position:0% +so we're not going to worry about that +for today and then there's a section + + align:start position:0% +for today and then there's a section + + + align:start position:0% +for today and then there's a section +called the symbol table shown here I + + align:start position:0% +called the symbol table shown here I + + + align:start position:0% +called the symbol table shown here I +think a simp type not on the screaming + + align:start position:0% +think a simp type not on the screaming + + + align:start position:0% +think a simp type not on the screaming +let me go back so + + align:start position:0% + + + + align:start position:0% + +that's the symbol table and what + + align:start position:0% +that's the symbol table and what + + + align:start position:0% +that's the symbol table and what +this symbol table shows is the + + align:start position:0% +this symbol table shows is the + + + align:start position:0% +this symbol table shows is the +different global variables and functions + + align:start position:0% +different global variables and functions + + + align:start position:0% +different global variables and functions +that are either defined in the module in + + align:start position:0% +that are either defined in the module in + + + align:start position:0% +that are either defined in the module in +this god of foil or are referenced by + + align:start position:0% +this god of foil or are referenced by + + + align:start position:0% +this god of foil or are referenced by +this module okay and for the symbols + + align:start position:0% +this module okay and for the symbols + + + align:start position:0% +this module okay and for the symbols +that are defined in this module what arm + + align:start position:0% +that are defined in this module what arm + + + align:start position:0% +that are defined in this module what arm +the symbol table tells you is the + + align:start position:0% +the symbol table tells you is the + + + align:start position:0% +the symbol table tells you is the +address at which you could find it in + + align:start position:0% +address at which you could find it in + + + align:start position:0% +address at which you could find it in +the module okay and for the things that + + align:start position:0% +the module okay and for the things that + + + align:start position:0% +the module okay and for the things that +are not defined it says it's undefined + + align:start position:0% +are not defined it says it's undefined + + + align:start position:0% +are not defined it says it's undefined +and hopefully once the compiler sees all + + align:start position:0% +and hopefully once the compiler sees all + + + align:start position:0% +and hopefully once the compiler sees all +of the different object files involved + + align:start position:0% +of the different object files involved + + + align:start position:0% +of the different object files involved +it can piece together these different + + align:start position:0% +it can piece together these different + + + align:start position:0% +it can piece together these different +object files and build larger program + + align:start position:0% +object files and build larger program + + + align:start position:0% +object files and build larger program +module so + + align:start position:0% +module so + + + align:start position:0% +module so +when you compile each of these things in + + align:start position:0% +when you compile each of these things in + + + align:start position:0% +when you compile each of these things in +this example m dot o and SQR dot o + + align:start position:0% +this example m dot o and SQR dot o + + + align:start position:0% +this example m dot o and SQR dot o +you'll find that the object file that's + + align:start position:0% +you'll find that the object file that's + + + align:start position:0% +you'll find that the object file that's +produced for both files has starts with + + align:start position:0% +produced for both files has starts with + + + align:start position:0% +produced for both files has starts with +address 0 ok so obviously when you hook + + align:start position:0% +address 0 ok so obviously when you hook + + + align:start position:0% +address 0 ok so obviously when you hook +these modules up together you can't have + + align:start position:0% +these modules up together you can't have + + + align:start position:0% +these modules up together you can't have +them both both modules run at address 0 + + align:start position:0% +them both both modules run at address 0 + + + align:start position:0% +them both both modules run at address 0 +so one of the things you need to be able + + align:start position:0% +so one of the things you need to be able + + + align:start position:0% +so one of the things you need to be able +to do is to take these different object + + align:start position:0% +to do is to take these different object + + + align:start position:0% +to do is to take these different object +files together and somehow join them so + + align:start position:0% +files together and somehow join them so + + + align:start position:0% +files together and somehow join them so +that the addresses are no longer + + align:start position:0% +that the addresses are no longer + + + align:start position:0% +that the addresses are no longer +colliding with one another ok so that's + + align:start position:0% +colliding with one another ok so that's + + + align:start position:0% +colliding with one another ok so that's +one problem that we're going to have to + + align:start position:0% +one problem that we're going to have to + + + align:start position:0% +one problem that we're going to have to +solve so + + align:start position:0% +solve so + + + align:start position:0% +solve so +that's that's what we're going to do + + align:start position:0% +that's that's what we're going to do + + + align:start position:0% +that's that's what we're going to do +today so + + align:start position:0% +today so + + + align:start position:0% +today so +there's basically three steps that + + align:start position:0% + + + + align:start position:0% + +we're going to talk about today the + + align:start position:0% +we're going to talk about today the + + + align:start position:0% +we're going to talk about today the +first step is figuring + + align:start position:0% +first step is figuring + + + align:start position:0% +first step is figuring +out all these different symbols so when + + align:start position:0% +out all these different symbols so when + + + align:start position:0% +out all these different symbols so when +you have sqr or if you were using square + + align:start position:0% +you have sqr or if you were using square + + + align:start position:0% +you have sqr or if you were using square +root in a different program printf is + + align:start position:0% +root in a different program printf is + + + align:start position:0% +root in a different program printf is +another example figuring out where the + + align:start position:0% +another example figuring out where the + + + align:start position:0% +another example figuring out where the +definitions of these symbols are and + + align:start position:0% +definitions of these symbols are and + + + align:start position:0% +definitions of these symbols are and +where the global variables definitions + + align:start position:0% +where the global variables definitions + + + align:start position:0% +where the global variables definitions +of the global variables are in your + + align:start position:0% +of the global variables are in your + + + align:start position:0% +of the global variables are in your +program and that's a step called symbol + + align:start position:0% +program and that's a step called symbol + + + align:start position:0% +program and that's a step called symbol +resolution ok + + align:start position:0% + + + + align:start position:0% + +and the plan is going to be that each + + align:start position:0% +and the plan is going to be that each + + + align:start position:0% +and the plan is going to be that each +object file is going to have inside a + + align:start position:0% +object file is going to have inside a + + + align:start position:0% +object file is going to have inside a +table like here that shows this + + align:start position:0% +table like here that shows this + + + align:start position:0% +table like here that shows this +for the symbols that it's look that has + + align:start position:0% +for the symbols that it's look that has + + + align:start position:0% +for the symbols that it's look that has +been they have been locally defined + + align:start position:0% +been they have been locally defined + + + align:start position:0% +been they have been locally defined +where in the local module they are I'm + + align:start position:0% +where in the local module they are I'm + + + align:start position:0% +where in the local module they are I'm +going to use the word module for these + + align:start position:0% +going to use the word module for these + + + align:start position:0% +going to use the word module for these +dot o files and for symbols that are not + + align:start position:0% +dot o files and for symbols that are not + + + align:start position:0% +dot o files and for symbols that are not +in the same data file um it just says + + align:start position:0% +in the same data file um it just says + + + align:start position:0% +in the same data file um it just says +it's undefined and I need it ok and + + align:start position:0% +it's undefined and I need it ok and + + + align:start position:0% +it's undefined and I need it ok and +that's what the dot o contains and when + + align:start position:0% +that's what the dot o contains and when + + + align:start position:0% +that's what the dot o contains and when +you + + align:start position:0% +you + + + align:start position:0% +you +take all these daughters together and + + align:start position:0% +take all these daughters together and + + + align:start position:0% +take all these daughters together and +produce a bigger program arm that's + + align:start position:0% +produce a bigger program arm that's + + + align:start position:0% +produce a bigger program arm that's +going to be on those symbols are going + + align:start position:0% +going to be on those symbols are going + + + align:start position:0% +going to be on those symbols are going +to be resolved and that's the step + + align:start position:0% +to be resolved and that's the step + + + align:start position:0% +to be resolved and that's the step +called symbol resolution the + + align:start position:0% +called symbol resolution the + + + align:start position:0% +called symbol resolution the +second step that we have to are the + + align:start position:0% +second step that we have to are the + + + align:start position:0% +second step that we have to are the +second thing we have to do before we get + + align:start position:0% +second thing we have to do before we get + + + align:start position:0% +second thing we have to do before we get +a single big program is to do something + + align:start position:0% +a single big program is to do something + + + align:start position:0% +a single big program is to do something +called relocation so + + align:start position:0% + + + + align:start position:0% + +what relocation is is remember I told + + align:start position:0% +what relocation is is remember I told + + + align:start position:0% +what relocation is is remember I told +you when you compile the program to a + + align:start position:0% +you when you compile the program to a + + + align:start position:0% +you when you compile the program to a +dot o file all of the dot o files all + + align:start position:0% +dot o file all of the dot o files all + + + align:start position:0% +dot o file all of the dot o files all +have the same all have addresses + + align:start position:0% +have the same all have addresses + + + align:start position:0% +have the same all have addresses +starting from zero you can't run them + + align:start position:0% +starting from zero you can't run them + + + align:start position:0% +starting from zero you can't run them +all together unless you actually modify + + align:start position:0% +all together unless you actually modify + + + align:start position:0% +all together unless you actually modify +the different addresses and any time you + + align:start position:0% +the different addresses and any time you + + + align:start position:0% +the different addresses and any time you +see a reference to a variable in one of + + align:start position:0% +see a reference to a variable in one of + + + align:start position:0% +see a reference to a variable in one of +the data files you have to modify that + + align:start position:0% +the data files you have to modify that + + + align:start position:0% +the data files you have to modify that +address to point to the actual address + + align:start position:0% +address to point to the actual address + + + align:start position:0% +address to point to the actual address +at which the arm instruction would run + + align:start position:0% +at which the arm instruction would run + + + align:start position:0% +at which the arm instruction would run +or the data object is present and that's + + align:start position:0% +or the data object is present and that's + + + align:start position:0% +or the data object is present and that's +called relocation and it'll + + align:start position:0% +called relocation and it'll + + + align:start position:0% +called relocation and it'll +turn out that the object files that are + + align:start position:0% +turn out that the object files that are + + + align:start position:0% +turn out that the object files that are +produced by the compiler are what are + + align:start position:0% +produced by the compiler are what are + + + align:start position:0% +produced by the compiler are what are +called relocatable object files pretty + + align:start position:0% +called relocatable object files pretty + + + align:start position:0% +called relocatable object files pretty +much every object file these days is + + align:start position:0% +much every object file these days is + + + align:start position:0% +much every object file these days is +relocatable but a relocatable object + + align:start position:0% +relocatable but a relocatable object + + + align:start position:0% +relocatable but a relocatable object +file allows you to do this relocation + + align:start position:0% +file allows you to do this relocation + + + align:start position:0% +file allows you to do this relocation +easily because it has in it information + + align:start position:0% +easily because it has in it information + + + align:start position:0% +easily because it has in it information +that tells arm whoever is composing + + align:start position:0% +that tells arm whoever is composing + + + align:start position:0% +that tells arm whoever is composing +these modules together how to modify the + + align:start position:0% +these modules together how to modify the + + + align:start position:0% +these modules together how to modify the +addresses that are referenced within + + align:start position:0% +addresses that are referenced within + + + align:start position:0% +addresses that are referenced within +each module and + + align:start position:0% +each module and + + + align:start position:0% +each module and +the third step once you do all this and + + align:start position:0% +the third step once you do all this and + + + align:start position:0% +the third step once you do all this and +you produce a single big program that's + + align:start position:0% +you produce a single big program that's + + + align:start position:0% +you produce a single big program that's +ready to execute is actually to run the + + align:start position:0% +ready to execute is actually to run the + + + align:start position:0% +ready to execute is actually to run the +program and that's a step called loading + + align:start position:0% +program and that's a step called loading + + + align:start position:0% +program and that's a step called loading +or + + align:start position:0% +or + + + align:start position:0% +or +program loading so + + align:start position:0% +program loading so + + + align:start position:0% +program loading so +you create a big executable file and you + + align:start position:0% +you create a big executable file and you + + + align:start position:0% +you create a big executable file and you +know you type it on the command line + + align:start position:0% +know you type it on the command line + + + align:start position:0% +know you type it on the command line +what happens ok so those are the three + + align:start position:0% +what happens ok so those are the three + + + align:start position:0% +what happens ok so those are the three +steps that we're going to be talking + + align:start position:0% +steps that we're going to be talking + + + align:start position:0% +steps that we're going to be talking +about today and the first two steps + + align:start position:0% +about today and the first two steps + + + align:start position:0% +about today and the first two steps +typically are called linking ok + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +most of today is going to be talking + + align:start position:0% +most of today is going to be talking + + + align:start position:0% +most of today is going to be talking +about how linking works and the piece of + + align:start position:0% +about how linking works and the piece of + + + align:start position:0% +about how linking works and the piece of +software a system software that does + + align:start position:0% +software a system software that does + + + align:start position:0% +software a system software that does +linking is called a linker and in our + + align:start position:0% +linking is called a linker and in our + + + align:start position:0% +linking is called a linker and in our +new Linux operating system it's a + + align:start position:0% +new Linux operating system it's a + + + align:start position:0% +new Linux operating system it's a +program called LD that's + + align:start position:0% +program called LD that's + + + align:start position:0% +program called LD that's +that's the linking program and so when + + align:start position:0% +that's the linking program and so when + + + align:start position:0% +that's the linking program and so when +you run GCC to take a bunch of modules + + align:start position:0% +you run GCC to take a bunch of modules + + + align:start position:0% +you run GCC to take a bunch of modules +and produce a program out of it + + align:start position:0% +and produce a program out of it + + + align:start position:0% +and produce a program out of it +underneath inside not visible to you but + + align:start position:0% +underneath inside not visible to you but + + + align:start position:0% +underneath inside not visible to you but +underneath our GCC actually invokes a + + align:start position:0% +underneath our GCC actually invokes a + + + align:start position:0% +underneath our GCC actually invokes a +bunch of other programs including LD is + + align:start position:0% +bunch of other programs including LD is + + + align:start position:0% +bunch of other programs including LD is +one of the last steps to produce + + align:start position:0% +one of the last steps to produce + + + align:start position:0% +one of the last steps to produce +an actual file that will run so + + align:start position:0% + + + + align:start position:0% + +the linker takes as input on object + + align:start position:0% +the linker takes as input on object + + + align:start position:0% +the linker takes as input on object +files and produces as output a program + + align:start position:0% +files and produces as output a program + + + align:start position:0% +files and produces as output a program +that you can run and then the loader + + align:start position:0% +that you can run and then the loader + + + align:start position:0% +that you can run and then the loader +takes over and runs the program so + + align:start position:0% +takes over and runs the program so + + + align:start position:0% +takes over and runs the program so +the kind there are two kinds of objects + + align:start position:0% +the kind there are two kinds of objects + + + align:start position:0% +the kind there are two kinds of objects +actually three kinds of object files + + align:start position:0% +actually three kinds of object files + + + align:start position:0% +actually three kinds of object files +that the linker takes as argument the + + align:start position:0% +that the linker takes as argument the + + + align:start position:0% +that the linker takes as argument the +first kind of object file arm is a + + align:start position:0% +first kind of object file arm is a + + + align:start position:0% +first kind of object file arm is a +relocatable object file okay + + align:start position:0% + + + + align:start position:0% + +actually there's two kinds the first + + align:start position:0% +actually there's two kinds the first + + + align:start position:0% +actually there's two kinds the first +kind is a relocatable object file and + + align:start position:0% +kind is a relocatable object file and + + + align:start position:0% +kind is a relocatable object file and +that's what we're going to be spending + + align:start position:0% +that's what we're going to be spending + + + align:start position:0% +that's what we're going to be spending +most of our time on the second kind of + + align:start position:0% +most of our time on the second kind of + + + align:start position:0% +most of our time on the second kind of +object file is something called a shared + + align:start position:0% +object file is something called a shared + + + align:start position:0% +object file is something called a shared +object file we're + + align:start position:0% + + + + align:start position:0% + +going to get to this in a little bit at + + align:start position:0% +going to get to this in a little bit at + + + align:start position:0% +going to get to this in a little bit at +the end and the reason we're going to + + align:start position:0% +the end and the reason we're going to + + + align:start position:0% +the end and the reason we're going to +wait until the end is that the reason + + align:start position:0% +wait until the end is that the reason + + + align:start position:0% +wait until the end is that the reason +for a shared object file is that if you + + align:start position:0% +for a shared object file is that if you + + + align:start position:0% +for a shared object file is that if you +have a program a module like printf or + + align:start position:0% +have a program a module like printf or + + + align:start position:0% +have a program a module like printf or +some math library like you know using + + align:start position:0% +some math library like you know using + + + align:start position:0% +some math library like you know using +functions like square root arm if + + align:start position:0% +functions like square root arm if + + + align:start position:0% +functions like square root arm if +you just do linking the normal way which + + align:start position:0% +you just do linking the normal way which + + + align:start position:0% +you just do linking the normal way which +is the easy way we're going to talk + + align:start position:0% +is the easy way we're going to talk + + + align:start position:0% +is the easy way we're going to talk +about for most of today you'll end up + + align:start position:0% +about for most of today you'll end up + + + align:start position:0% +about for most of today you'll end up +with a program that includes in it in + + align:start position:0% +with a program that includes in it in + + + align:start position:0% +with a program that includes in it in +its text that includes in that in the + + align:start position:0% +its text that includes in that in the + + + align:start position:0% +its text that includes in that in the +binary arm all of the modules + + align:start position:0% +binary arm all of the modules + + + align:start position:0% +binary arm all of the modules +corresponding to all of the libraries or + + align:start position:0% +corresponding to all of the libraries or + + + align:start position:0% +corresponding to all of the libraries or +all of the other all of them you know + + align:start position:0% +all of the other all of them you know + + + align:start position:0% +all of the other all of them you know +the text correspond to the different + + align:start position:0% +the text correspond to the different + + + align:start position:0% +the text correspond to the different +modules that you use so now if you have + + align:start position:0% +modules that you use so now if you have + + + align:start position:0% +modules that you use so now if you have +100 programs running on your system all + + align:start position:0% +100 programs running on your system all + + + align:start position:0% +100 programs running on your system all +of which use printf it will turn out + + align:start position:0% +of which use printf it will turn out + + + align:start position:0% +of which use printf it will turn out +that every program is quite big and so + + align:start position:0% +that every program is quite big and so + + + align:start position:0% +that every program is quite big and so +shared object files allow us to arm not + + align:start position:0% +shared object files allow us to arm not + + + align:start position:0% +shared object files allow us to arm not +actually have to include the text of + + align:start position:0% +actually have to include the text of + + + align:start position:0% +actually have to include the text of +printf in every binary that we produce + + align:start position:0% +printf in every binary that we produce + + + align:start position:0% +printf in every binary that we produce +but just maintain a pointer to something + + align:start position:0% +but just maintain a pointer to something + + + align:start position:0% +but just maintain a pointer to something +that says oh when you need printf go and + + align:start position:0% +that says oh when you need printf go and + + + align:start position:0% +that says oh when you need printf go and +get this and include it as part of your + + align:start position:0% +get this and include it as part of your + + + align:start position:0% +get this and include it as part of your +program so we'll get to that in the end + + align:start position:0% +program so we'll get to that in the end + + + align:start position:0% +program so we'll get to that in the end +but for the most part we're going to be + + align:start position:0% +but for the most part we're going to be + + + align:start position:0% +but for the most part we're going to be +focusing on relocatable object files + + align:start position:0% +focusing on relocatable object files + + + align:start position:0% +focusing on relocatable object files +that is object files that are produced + + align:start position:0% +that is object files that are produced + + + align:start position:0% +that is object files that are produced +by something like GCC that I showed you + + align:start position:0% +by something like GCC that I showed you + + + align:start position:0% +by something like GCC that I showed you +which include init information for on + + align:start position:0% +which include init information for on + + + align:start position:0% +which include init information for on +arm you know modifying the addresses + + align:start position:0% +arm you know modifying the addresses + + + align:start position:0% +arm you know modifying the addresses +that are being referenced inside the + + align:start position:0% +that are being referenced inside the + + + align:start position:0% +that are being referenced inside the +module and once + + align:start position:0% +module and once + + + align:start position:0% +module and once +the linker takes these as arguments what + + align:start position:0% +the linker takes these as arguments what + + + align:start position:0% +the linker takes these as arguments what +it produces as output outcomes + + align:start position:0% +it produces as output outcomes + + + align:start position:0% +it produces as output outcomes +an executable file + + align:start position:0% +an executable file + + + align:start position:0% +an executable file +these + + align:start position:0% + + + + align:start position:0% + +daughters don't actually run the + + align:start position:0% +daughters don't actually run the + + + align:start position:0% +daughters don't actually run the +executable is a thing that's capable of + + align:start position:0% +executable is a thing that's capable of + + + align:start position:0% +executable is a thing that's capable of +actually running okay + + align:start position:0% + + + + align:start position:0% + +so the first step we have to talk about + + align:start position:0% +so the first step we have to talk about + + + align:start position:0% +so the first step we have to talk about +is symbol resolution and + + align:start position:0% + + + + align:start position:0% + +so the input is a set of object files + + align:start position:0% +so the input is a set of object files + + + align:start position:0% +so the input is a set of object files +and the output is going to be something + + align:start position:0% +and the output is going to be something + + + align:start position:0% +and the output is going to be something +that arm allows LD the linker program to + + align:start position:0% +that arm allows LD the linker program to + + + align:start position:0% +that arm allows LD the linker program to +know which symbol is located where um in + + align:start position:0% +know which symbol is located where um in + + + align:start position:0% +know which symbol is located where um in +all of the different modules and if + + align:start position:0% +all of the different modules and if + + + align:start position:0% +all of the different modules and if +you're linking succeeds then it means + + align:start position:0% +you're linking succeeds then it means + + + align:start position:0% +you're linking succeeds then it means +that every R every symbol that's been + + align:start position:0% +that every R every symbol that's been + + + align:start position:0% +that every R every symbol that's been +referenced by any of the modules in this + + align:start position:0% +referenced by any of the modules in this + + + align:start position:0% +referenced by any of the modules in this +on the command line of this LD program + + align:start position:0% +on the command line of this LD program + + + align:start position:0% +on the command line of this LD program +um there are no undefined symbols + + align:start position:0% +um there are no undefined symbols + + + align:start position:0% +um there are no undefined symbols +remaining so that's what symbol + + align:start position:0% +remaining so that's what symbol + + + align:start position:0% +remaining so that's what symbol +resolution does and the input to this is + + align:start position:0% +resolution does and the input to this is + + + align:start position:0% +resolution does and the input to this is +really it looks something like you know + + align:start position:0% +really it looks something like you know + + + align:start position:0% +really it looks something like you know +you have a bunch of files I'm going to + + align:start position:0% +you have a bunch of files I'm going to + + + align:start position:0% +you have a bunch of files I'm going to +call them f1 dot o f2 dot o all the way + + align:start position:0% +call them f1 dot o f2 dot o all the way + + + align:start position:0% +call them f1 dot o f2 dot o all the way +through FN dot o okay and for those of + + align:start position:0% +through FN dot o okay and for those of + + + align:start position:0% +through FN dot o okay and for those of +you who know about libraries don't worry + + align:start position:0% +you who know about libraries don't worry + + + align:start position:0% +you who know about libraries don't worry +about them now we're just going to take + + align:start position:0% +about them now we're just going to take + + + align:start position:0% +about them now we're just going to take +these individual modules and we're going + + align:start position:0% +these individual modules and we're going + + + align:start position:0% +these individual modules and we're going +to produce out of it on a single program + + align:start position:0% +to produce out of it on a single program + + + align:start position:0% +to produce out of it on a single program +that includes + + align:start position:0% +that includes + + + align:start position:0% +that includes +in it all of these different modules and + + align:start position:0% +in it all of these different modules and + + + align:start position:0% +in it all of these different modules and +such that there are no unresolved + + align:start position:0% +such that there are no unresolved + + + align:start position:0% +such that there are no unresolved +symbols okay so when there's you know + + align:start position:0% +symbols okay so when there's you know + + + align:start position:0% +symbols okay so when there's you know +sqr is one file and m dot c contains + + align:start position:0% +sqr is one file and m dot c contains + + + align:start position:0% +sqr is one file and m dot c contains +references sqr we want to make it so the + + align:start position:0% +references sqr we want to make it so the + + + align:start position:0% +references sqr we want to make it so the +actual program when the reference to sqr + + align:start position:0% +actual program when the reference to sqr + + + align:start position:0% +actual program when the reference to sqr +comes in you know where it is okay so + + align:start position:0% +comes in you know where it is okay so + + + align:start position:0% +comes in you know where it is okay so +what each file contains when you do GCC + + align:start position:0% +what each file contains when you do GCC + + + align:start position:0% +what each file contains when you do GCC +on f1 dot c and you get f1 dot o um it + + align:start position:0% +on f1 dot c and you get f1 dot o um it + + + align:start position:0% +on f1 dot c and you get f1 dot o um it +contains in it already a local symbol + + align:start position:0% +contains in it already a local symbol + + + align:start position:0% +contains in it already a local symbol +table you saw that in the example I + + align:start position:0% +table you saw that in the example I + + + align:start position:0% +table you saw that in the example I +showed you and the symbol table has the + + align:start position:0% +showed you and the symbol table has the + + + align:start position:0% +showed you and the symbol table has the +following structure there's two kinds of + + align:start position:0% +following structure there's two kinds of + + + align:start position:0% +following structure there's two kinds of +data in the symbol table on a local + + align:start position:0% +data in the symbol table on a local + + + align:start position:0% +data in the symbol table on a local +module the first is a set of items d1 + + align:start position:0% +module the first is a set of items d1 + + + align:start position:0% +module the first is a set of items d1 +that correspond to armed global + + align:start position:0% +that correspond to armed global + + + align:start position:0% +that correspond to armed global +variables or functions that are defined + + align:start position:0% +variables or functions that are defined + + + align:start position:0% +variables or functions that are defined +in the module f1 dot C and therefore are + + align:start position:0% +in the module f1 dot C and therefore are + + + align:start position:0% +in the module f1 dot C and therefore are +defined in the module f1 dot o so this + + align:start position:0% +defined in the module f1 dot o so this + + + align:start position:0% +defined in the module f1 dot o so this +just tells the linker you know if you + + align:start position:0% +just tells the linker you know if you + + + align:start position:0% +just tells the linker you know if you +see the symbol being invoked by somebody + + align:start position:0% +see the symbol being invoked by somebody + + + align:start position:0% +see the symbol being invoked by somebody +else it's being referred it's being + + align:start position:0% +else it's being referred it's being + + + align:start position:0% +else it's being referred it's being +defined in this module ok and + + align:start position:0% +defined in this module ok and + + + align:start position:0% +defined in this module ok and +it contains information about where in + + align:start position:0% +it contains information about where in + + + align:start position:0% +it contains information about where in +the local module it's present so that + + align:start position:0% +the local module it's present so that + + + align:start position:0% +the local module it's present so that +you know what what address it's being + + align:start position:0% +you know what what address it's being + + + align:start position:0% +you know what what address it's being +defined and so on likewise you have here + + align:start position:0% +defined and so on likewise you have here + + + align:start position:0% +defined and so on likewise you have here +another set of symbols you want which + + align:start position:0% +another set of symbols you want which + + + align:start position:0% +another set of symbols you want which +corresponds to things that are not + + align:start position:0% +corresponds to things that are not + + + align:start position:0% +corresponds to things that are not +defined in f1 dot o and likewise for + + align:start position:0% +defined in f1 dot o and likewise for + + + align:start position:0% +defined in f1 dot o and likewise for +each of these things you have um D 2 and + + align:start position:0% +each of these things you have um D 2 and + + + align:start position:0% +each of these things you have um D 2 and +u + + align:start position:0% +u + + + align:start position:0% +u +2 and so on okay so + + align:start position:0% + + + + align:start position:0% + +the way of the particular implementation + + align:start position:0% +the way of the particular implementation + + + align:start position:0% +the way of the particular implementation +of M of the linker under gnu/linux works + + align:start position:0% +of M of the linker under gnu/linux works + + + align:start position:0% +of M of the linker under gnu/linux works +and there are many ways to implement + + align:start position:0% +and there are many ways to implement + + + align:start position:0% +and there are many ways to implement +linkers and they're very complicated + + align:start position:0% +linkers and they're very complicated + + + align:start position:0% +linkers and they're very complicated +linkers and simple and crisp and + + align:start position:0% +linkers and simple and crisp and + + + align:start position:0% +linkers and simple and crisp and +obviously simple linkers as well or the + + align:start position:0% +obviously simple linkers as well or the + + + align:start position:0% +obviously simple linkers as well or the +UNIX one the Lunas one is particularly + + align:start position:0% +UNIX one the Lunas one is particularly + + + align:start position:0% +UNIX one the Lunas one is particularly +simple at least in terms of this way of + + align:start position:0% +simple at least in terms of this way of + + + align:start position:0% +simple at least in terms of this way of +linking um taking you know resolving all + + align:start position:0% +linking um taking you know resolving all + + + align:start position:0% +linking um taking you know resolving all +of the symbols here you just can the + + align:start position:0% +of the symbols here you just can the + + + align:start position:0% +of the symbols here you just can the +command line from left to right and you + + align:start position:0% +command line from left to right and you + + + align:start position:0% +command line from left to right and you +start building up three sets okay so + + align:start position:0% +start building up three sets okay so + + + align:start position:0% +start building up three sets okay so +we're going to build up three sets in + + align:start position:0% +we're going to build up three sets in + + + align:start position:0% +we're going to build up three sets in +this algorithm when we scan from left to + + align:start position:0% +this algorithm when we scan from left to + + + align:start position:0% +this algorithm when we scan from left to +right the first set is a set I'm going + + align:start position:0% +right the first set is a set I'm going + + + align:start position:0% +right the first set is a set I'm going +to call o and the idea I know is going + + align:start position:0% +to call o and the idea I know is going + + + align:start position:0% +to call o and the idea I know is going +to be all of the object files that go + + align:start position:0% +to be all of the object files that go + + + align:start position:0% +to be all of the object files that go +into the program that go into the output + + align:start position:0% +into the program that go into the output + + + align:start position:0% +into the program that go into the output +of the linking step in this case in the + + align:start position:0% +of the linking step in this case in the + + + align:start position:0% +of the linking step in this case in the +end it's going to be pretty + + align:start position:0% +end it's going to be pretty + + + align:start position:0% +end it's going to be pretty +straightforward it's going to be F $1 + + align:start position:0% +straightforward it's going to be F $1 + + + align:start position:0% +straightforward it's going to be F $1 +Union f2 all the way up to Union F M + + align:start position:0% +Union f2 all the way up to Union F M + + + align:start position:0% +Union f2 all the way up to Union F M +it's going to get a little more + + align:start position:0% +it's going to get a little more + + + align:start position:0% +it's going to get a little more +complicated when we talk about libraries + + align:start position:0% +complicated when we talk about libraries + + + align:start position:0% +complicated when we talk about libraries +but for now it's a very easy set when + + align:start position:0% +but for now it's a very easy set when + + + align:start position:0% +but for now it's a very easy set when +you see when you scan from left to right + + align:start position:0% +you see when you scan from left to right + + + align:start position:0% +you see when you scan from left to right +you look at the next object module or + + align:start position:0% +you look at the next object module or + + + align:start position:0% +you look at the next object module or +the object file and all you have to do + + align:start position:0% +the object file and all you have to do + + + align:start position:0% +the object file and all you have to do +is all goes to all Union arm fi + + align:start position:0% + + + + align:start position:0% + +dot o okay + + align:start position:0% +dot o okay + + + align:start position:0% +dot o okay +this is the ID step of the algorithm + + align:start position:0% +this is the ID step of the algorithm + + + align:start position:0% +this is the ID step of the algorithm +okay now + + align:start position:0% +okay now + + + align:start position:0% +okay now +we have to go to the next step which is + + align:start position:0% +we have to go to the next step which is + + + align:start position:0% +we have to go to the next step which is +get to the defined symbols so as we go + + align:start position:0% +get to the defined symbols so as we go + + + align:start position:0% +get to the defined symbols so as we go +from left to right we build up a set of + + align:start position:0% +from left to right we build up a set of + + + align:start position:0% +from left to right we build up a set of +defined symbols initially it's d1 + + align:start position:0% +defined symbols initially it's d1 + + + align:start position:0% +defined symbols initially it's d1 +initially it's null and then you start + + align:start position:0% +initially it's null and then you start + + + align:start position:0% +initially it's null and then you start +with D 1 and then we do D 1 Union D 2 + + align:start position:0% +with D 1 and then we do D 1 Union D 2 + + + align:start position:0% +with D 1 and then we do D 1 Union D 2 +and all the way so up to the ith step + + align:start position:0% +and all the way so up to the ith step + + + align:start position:0% +and all the way so up to the ith step +what we're going to end up with is + + align:start position:0% +what we're going to end up with is + + + align:start position:0% +what we're going to end up with is +obviously at the ith iteration we're + + align:start position:0% +obviously at the ith iteration we're + + + align:start position:0% +obviously at the ith iteration we're +going to have some running of set of + + align:start position:0% +going to have some running of set of + + + align:start position:0% +going to have some running of set of +defined symbols that have been defined + + align:start position:0% +defined symbols that have been defined + + + align:start position:0% +defined symbols that have been defined +in the modules so far and we're just + + align:start position:0% +in the modules so far and we're just + + + align:start position:0% +in the modules so far and we're just +going to do D goes to D Union di where + + align:start position:0% +going to do D goes to D Union di where + + + align:start position:0% +going to do D goes to D Union di where +di is the set of symbols that are + + align:start position:0% +di is the set of symbols that are + + + align:start position:0% +di is the set of symbols that are +defined in module number I ok + + align:start position:0% +defined in module number I ok + + + align:start position:0% +defined in module number I ok +the law set we're going to do we're + + align:start position:0% +the law set we're going to do we're + + + align:start position:0% +the law set we're going to do we're +going to calculate if the linker is + + align:start position:0% +going to calculate if the linker is + + + align:start position:0% +going to calculate if the linker is +going to calculate is set you and use + + align:start position:0% +going to calculate is set you and use + + + align:start position:0% +going to calculate is set you and use +the set of all undefined symbols so far + + align:start position:0% +the set of all undefined symbols so far + + + align:start position:0% +the set of all undefined symbols so far +so you have a set of undefined symbols + + align:start position:0% +so you have a set of undefined symbols + + + align:start position:0% +so you have a set of undefined symbols +and you're at the ith stage of this + + align:start position:0% +and you're at the ith stage of this + + + align:start position:0% +and you're at the ith stage of this +process where up to here you have a set + + align:start position:0% +process where up to here you have a set + + + align:start position:0% +process where up to here you have a set +u of undefined symbols and now you see + + align:start position:0% +u of undefined symbols and now you see + + + align:start position:0% +u of undefined symbols and now you see +in this new module a bunch more + + align:start position:0% +in this new module a bunch more + + + align:start position:0% +in this new module a bunch more +undefined symbols so clearly what you + + align:start position:0% +undefined symbols so clearly what you + + + align:start position:0% +undefined symbols so clearly what you +have to do first is do you union UI + + align:start position:0% +have to do first is do you union UI + + + align:start position:0% +have to do first is do you union UI +correct + + align:start position:0% +correct + + + align:start position:0% +correct +because you have built up a bigger set + + align:start position:0% +because you have built up a bigger set + + + align:start position:0% +because you have built up a bigger set +of undefined symbols but then notice + + align:start position:0% +of undefined symbols but then notice + + + align:start position:0% +of undefined symbols but then notice +that there might be symbols that were + + align:start position:0% +that there might be symbols that were + + + align:start position:0% +that there might be symbols that were +previously undefined that are now being + + align:start position:0% +previously undefined that are now being + + + align:start position:0% +previously undefined that are now being +defined in the module in the ith module + + align:start position:0% +defined in the module in the ith module + + + align:start position:0% +defined in the module in the ith module +right otherwise I mean if the set kept + + align:start position:0% +right otherwise I mean if the set kept + + + align:start position:0% +right otherwise I mean if the set kept +growing then all you would end up with + + align:start position:0% +growing then all you would end up with + + + align:start position:0% +growing then all you would end up with +is a big undefined set at the end so + + align:start position:0% +is a big undefined set at the end so + + + align:start position:0% +is a big undefined set at the end so +clearly there are symbols that are being + + align:start position:0% +clearly there are symbols that are being + + + align:start position:0% +clearly there are symbols that are being +defined in subsequent modules so you + + align:start position:0% +defined in subsequent modules so you + + + align:start position:0% +defined in subsequent modules so you +have to subtract out a set and the set + + align:start position:0% +have to subtract out a set and the set + + + align:start position:0% +have to subtract out a set and the set +you have to subtract out obviously is + + align:start position:0% +you have to subtract out obviously is + + + align:start position:0% +you have to subtract out obviously is +the undefined set intersection whatever + + align:start position:0% +the undefined set intersection whatever + + + align:start position:0% +the undefined set intersection whatever +is being defined in this module okay + + align:start position:0% +is being defined in this module okay + + + align:start position:0% +is being defined in this module okay +and so the linker does this from left to + + align:start position:0% +and so the linker does this from left to + + + align:start position:0% +and so the linker does this from left to +right it's actually pretty simple linker + + align:start position:0% +right it's actually pretty simple linker + + + align:start position:0% +right it's actually pretty simple linker +because it doesn't go back and do + + align:start position:0% +because it doesn't go back and do + + + align:start position:0% +because it doesn't go back and do +anything and it doesn't actually have to + + align:start position:0% +anything and it doesn't actually have to + + + align:start position:0% +anything and it doesn't actually have to +for at least for this way of hooking up + + align:start position:0% +for at least for this way of hooking up + + + align:start position:0% +for at least for this way of hooking up +object files together and what you get + + align:start position:0% +object files together and what you get + + + align:start position:0% +object files together and what you get +at the end are three sets OD and you + + align:start position:0% +at the end are three sets OD and you + + + align:start position:0% +at the end are three sets OD and you +okay and the linker outputs success and + + align:start position:0% +okay and the linker outputs success and + + + align:start position:0% +okay and the linker outputs success and +it then gets to the relocation stage if + + align:start position:0% +it then gets to the relocation stage if + + + align:start position:0% +it then gets to the relocation stage if +u is null right there are no undefined + + align:start position:0% +u is null right there are no undefined + + + align:start position:0% +u is null right there are no undefined +symbols at the end you know that now you + + align:start position:0% +symbols at the end you know that now you + + + align:start position:0% +symbols at the end you know that now you +can then relocate by modifying packing + + align:start position:0% +can then relocate by modifying packing + + + align:start position:0% +can then relocate by modifying packing +the different addresses together to + + align:start position:0% +the different addresses together to + + + align:start position:0% +the different addresses together to +produce your big program but if the set + + align:start position:0% +produce your big program but if the set + + + align:start position:0% +produce your big program but if the set +is not now you know that no matter what + + align:start position:0% +is not now you know that no matter what + + + align:start position:0% +is not now you know that no matter what +you do to relocate there's some symbol + + align:start position:0% +you do to relocate there's some symbol + + + align:start position:0% +you do to relocate there's some symbol +that's not being defined which means + + align:start position:0% +that's not being defined which means + + + align:start position:0% +that's not being defined which means +that module won't run which means the + + align:start position:0% +that module won't run which means the + + + align:start position:0% +that module won't run which means the +program won't run okay so that's kind of + + align:start position:0% +program won't run okay so that's kind of + + + align:start position:0% +program won't run okay so that's kind of +what of this linking program does it + + align:start position:0% +what of this linking program does it + + + align:start position:0% +what of this linking program does it +just goes from left to right and + + align:start position:0% +just goes from left to right and + + + align:start position:0% +just goes from left to right and +resolves all symbols and although it's + + align:start position:0% +resolves all symbols and although it's + + + align:start position:0% +resolves all symbols and although it's +done in the concept we've discussed this + + align:start position:0% +done in the concept we've discussed this + + + align:start position:0% +done in the concept we've discussed this +in the context of a particular example + + align:start position:0% +in the context of a particular example + + + align:start position:0% +in the context of a particular example +with how gnu/linux does its linking the + + align:start position:0% +with how gnu/linux does its linking the + + + align:start position:0% +with how gnu/linux does its linking the +basic idea is the same essentially all + + align:start position:0% +basic idea is the same essentially all + + + align:start position:0% +basic idea is the same essentially all +symbol resolution will turn out to use + + align:start position:0% +symbol resolution will turn out to use + + + align:start position:0% +symbol resolution will turn out to use +some variant of this some something that + + align:start position:0% +some variant of this some something that + + + align:start position:0% +some variant of this some something that +greatly resolve resembles this method + + align:start position:0% +greatly resolve resembles this method + + + align:start position:0% +greatly resolve resembles this method +there's + + align:start position:0% +there's + + + align:start position:0% +there's +actually only one problem with what I + + align:start position:0% +actually only one problem with what I + + + align:start position:0% +actually only one problem with what I +described so far it's wrong so what's + + align:start position:0% +described so far it's wrong so what's + + + align:start position:0% +described so far it's wrong so what's +the problem + + align:start position:0% +the problem + + + align:start position:0% +the problem +Yeah right if + + align:start position:0% + + + + align:start position:0% + +a symbol is undefined an f1 and define + + align:start position:0% +a symbol is undefined an f1 and define + + + align:start position:0% +a symbol is undefined an f1 and define +an f2 you're fine because let's say + + align:start position:0% +an f2 you're fine because let's say + + + align:start position:0% +an f2 you're fine because let's say +let's take this example I had m dots + + align:start position:0% +let's take this example I had m dots + + + align:start position:0% +let's take this example I had m dots +it's + + align:start position:0% +it's + + + align:start position:0% +it's +okay we're just building up steps so you + + align:start position:0% +okay we're just building up steps so you + + + align:start position:0% +okay we're just building up steps so you +can have a symbol that's defined you're + + align:start position:0% +can have a symbol that's defined you're + + + align:start position:0% +can have a symbol that's defined you're +saying what if the symbol is defined in + + align:start position:0% +saying what if the symbol is defined in + + + align:start position:0% +saying what if the symbol is defined in +one of the files and undefined in the + + align:start position:0% +one of the files and undefined in the + + + align:start position:0% +one of the files and undefined in the +next file no + + align:start position:0% +next file no + + + align:start position:0% +next file no +it doesn't matter for this it's going to + + align:start position:0% +it doesn't matter for this it's going to + + + align:start position:0% +it doesn't matter for this it's going to +matter when we talk about something + + align:start position:0% +matter when we talk about something + + + align:start position:0% +matter when we talk about something +called a library but it's not going to + + align:start position:0% +called a library but it's not going to + + + align:start position:0% +called a library but it's not going to +matter here because we built up these + + align:start position:0% +matter here because we built up these + + + align:start position:0% +matter here because we built up these +sets of water defined and water + + align:start position:0% +sets of water defined and water + + + align:start position:0% +sets of water defined and water +undefined so let's say you define a + + align:start position:0% +undefined so let's say you define a + + + align:start position:0% +undefined so let's say you define a +symbol here and you come here and you + + align:start position:0% +symbol here and you come here and you + + + align:start position:0% +symbol here and you come here and you +find that it references a symbol that's + + align:start position:0% +find that it references a symbol that's + + + align:start position:0% +find that it references a symbol that's +not locally defined but has been + + align:start position:0% +not locally defined but has been + + + align:start position:0% +not locally defined but has been +previously defined right that's been + + align:start position:0% +previously defined right that's been + + + align:start position:0% +previously defined right that's been +built up in the set D so in the end oh I + + align:start position:0% + + + + align:start position:0% + +see so the code is a little wrong + + align:start position:0% +see so the code is a little wrong + + + align:start position:0% +see so the code is a little wrong +because I have to actually update arm + + align:start position:0% +because I have to actually update arm + + + align:start position:0% +because I have to actually update arm +that's + + align:start position:0% +that's + + + align:start position:0% +that's +not your + + align:start position:0% +not your + + + align:start position:0% +not your +right I have to modify that you line it + + align:start position:0% +right I have to modify that you line it + + + align:start position:0% +right I have to modify that you line it +is wrong good so I have to modify the + + align:start position:0% +is wrong good so I have to modify the + + + align:start position:0% +is wrong good so I have to modify the +set of undefined symbols to include the + + align:start position:0% +set of undefined symbols to include the + + + align:start position:0% +set of undefined symbols to include the +things that were previously defined in + + align:start position:0% +things that were previously defined in + + + align:start position:0% +things that were previously defined in +so actually it should probably have been + + align:start position:0% +so actually it should probably have been + + + align:start position:0% +so actually it should probably have been +of you intersection D and that will + + align:start position:0% +of you intersection D and that will + + + align:start position:0% +of you intersection D and that will +probably fix it good + + align:start position:0% +probably fix it good + + + align:start position:0% +probably fix it good +any other errors + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +so there were two this one I actually + + align:start position:0% +so there were two this one I actually + + + align:start position:0% +so there were two this one I actually +didn't realize but it's actually right + + align:start position:0% +didn't realize but it's actually right + + + align:start position:0% +didn't realize but it's actually right +so it should be you know sexually the + + align:start position:0% +so it should be you know sexually the + + + align:start position:0% +so it should be you know sexually the +other one is that we just keep doing D + + align:start position:0% +other one is that we just keep doing D + + + align:start position:0% +other one is that we just keep doing D +goes to D Union di but now if I define + + align:start position:0% +goes to D Union di but now if I define + + + align:start position:0% +goes to D Union di but now if I define +the function module a function s Q R + + align:start position:0% +the function module a function s Q R + + + align:start position:0% +the function module a function s Q R +here and I define the same function s Q + + align:start position:0% +here and I define the same function s Q + + + align:start position:0% +here and I define the same function s Q +R again here um we're not going to know + + align:start position:0% +R again here um we're not going to know + + + align:start position:0% +R again here um we're not going to know +which s QR to actually use so we have a + + align:start position:0% +which s QR to actually use so we have a + + + align:start position:0% +which s QR to actually use so we have a +duplicate symbol and so in fact um what + + align:start position:0% +duplicate symbol and so in fact um what + + + align:start position:0% +duplicate symbol and so in fact um what +the algorithm actually ought to do is + + align:start position:0% +the algorithm actually ought to do is + + + align:start position:0% +the algorithm actually ought to do is +while it's doing this Union computation + + align:start position:0% +while it's doing this Union computation + + + align:start position:0% +while it's doing this Union computation +it better make sure that any symbol + + align:start position:0% +it better make sure that any symbol + + + align:start position:0% +it better make sure that any symbol +that's being defined in the subsequent + + align:start position:0% +that's being defined in the subsequent + + + align:start position:0% +that's being defined in the subsequent +module has not already been defined in a + + align:start position:0% +module has not already been defined in a + + + align:start position:0% +module has not already been defined in a +previous module and if there is a + + align:start position:0% +previous module and if there is a + + + align:start position:0% +previous module and if there is a +duplicate definition it'll tell you that + + align:start position:0% +duplicate definition it'll tell you that + + + align:start position:0% +duplicate definition it'll tell you that +there's a duplicate definition and I'm + + align:start position:0% +there's a duplicate definition and I'm + + + align:start position:0% +there's a duplicate definition and I'm +not going to show you an example but if + + align:start position:0% +not going to show you an example but if + + + align:start position:0% +not going to show you an example but if +you just go and type out us a little you + + align:start position:0% +you just go and type out us a little you + + + align:start position:0% +you just go and type out us a little you +know use s QR twice and you run the + + align:start position:0% +know use s QR twice and you run the + + + align:start position:0% +know use s QR twice and you run the +compiler GCC on it what you'll find is + + align:start position:0% +compiler GCC on it what you'll find is + + + align:start position:0% +compiler GCC on it what you'll find is +that it will tell you that this symbol + + align:start position:0% +that it will tell you that this symbol + + + align:start position:0% +that it will tell you that this symbol +multiple is multiplied defined okay so + + align:start position:0% +multiple is multiplied defined okay so + + + align:start position:0% +multiple is multiplied defined okay so +we're not going to want that either so + + align:start position:0% +we're not going to want that either so + + + align:start position:0% +we're not going to want that either so +once you do these get obtain these + + align:start position:0% +once you do these get obtain these + + + align:start position:0% +once you do these get obtain these +different sets what you'll end up with + + align:start position:0% +different sets what you'll end up with + + + align:start position:0% +different sets what you'll end up with +is armed and use null what you'll end up + + align:start position:0% +is armed and use null what you'll end up + + + align:start position:0% +is armed and use null what you'll end up +with is information that will tell the + + align:start position:0% +with is information that will tell the + + + align:start position:0% +with is information that will tell the +linker everything about all of the + + align:start position:0% +linker everything about all of the + + + align:start position:0% +linker everything about all of the +different symbols and where they've been + + align:start position:0% +different symbols and where they've been + + + align:start position:0% +different symbols and where they've been +defined and in which object file they've + + align:start position:0% +defined and in which object file they've + + + align:start position:0% +defined and in which object file they've +been defined and so the step that it has + + align:start position:0% +been defined and so the step that it has + + + align:start position:0% +been defined and so the step that it has +to do after that is the relocation step + + align:start position:0% +to do after that is the relocation step + + + align:start position:0% +to do after that is the relocation step +so this was the first step it'll + + align:start position:0% + + + + align:start position:0% + +turn out that this step is also pretty + + align:start position:0% +turn out that this step is also pretty + + + align:start position:0% +turn out that this step is also pretty +straightforward because what what will + + align:start position:0% +straightforward because what what will + + + align:start position:0% +straightforward because what what will +what happens when GCC iran's on a single + + align:start position:0% +what happens when GCC iran's on a single + + + align:start position:0% +what happens when GCC iran's on a single +object in on a single c file and + + align:start position:0% +object in on a single c file and + + + align:start position:0% +object in on a single c file and +produces a single dot o file is it + + align:start position:0% +produces a single dot o file is it + + + align:start position:0% +produces a single dot o file is it +contains in it information on how to + + align:start position:0% +contains in it information on how to + + + align:start position:0% +contains in it information on how to +relocate all of the variables and all of + + align:start position:0% +relocate all of the variables and all of + + + align:start position:0% +relocate all of the variables and all of +the functions that are defined in that + + align:start position:0% +the functions that are defined in that + + + align:start position:0% +the functions that are defined in that +in that module and there's + + align:start position:0% +in that module and there's + + + align:start position:0% +in that module and there's +a portion there's a section of the + + align:start position:0% +a portion there's a section of the + + + align:start position:0% +a portion there's a section of the +object file that I haven't shown you + + align:start position:0% +object file that I haven't shown you + + + align:start position:0% +object file that I haven't shown you +called the relocation section that tells + + align:start position:0% +called the relocation section that tells + + + align:start position:0% +called the relocation section that tells +you for any given variable in the text + + align:start position:0% +you for any given variable in the text + + + align:start position:0% +you for any given variable in the text +for any given line of code in the text + + align:start position:0% +for any given line of code in the text + + + align:start position:0% +for any given line of code in the text +area all of the load instructions and + + align:start position:0% +area all of the load instructions and + + + align:start position:0% +area all of the load instructions and +all of the variables how they get re map + + align:start position:0% +all of the variables how they get re map + + + align:start position:0% +all of the variables how they get re map +inside so that's maintain basically the + + align:start position:0% +inside so that's maintain basically the + + + align:start position:0% +inside so that's maintain basically the +approach is to maintain a local table um + + align:start position:0% +approach is to maintain a local table um + + + align:start position:0% +approach is to maintain a local table um +in and it's called the relocation + + align:start position:0% +in and it's called the relocation + + + align:start position:0% +in and it's called the relocation +section view of your program okay + + align:start position:0% +section view of your program okay + + + align:start position:0% +section view of your program okay +so we're going to get to loading in a + + align:start position:0% +so we're going to get to loading in a + + + align:start position:0% +so we're going to get to loading in a +little bit but before we get to loading + + align:start position:0% +little bit but before we get to loading + + + align:start position:0% +little bit but before we get to loading +I want to get back to simple resolution + + align:start position:0% +I want to get back to simple resolution + + + align:start position:0% +I want to get back to simple resolution +so here we just talked about taking a + + align:start position:0% +so here we just talked about taking a + + + align:start position:0% +so here we just talked about taking a +bunch of dot o files and producing a + + align:start position:0% +bunch of dot o files and producing a + + + align:start position:0% +bunch of dot o files and producing a +final program but there is another + + align:start position:0% +final program but there is another + + + align:start position:0% +final program but there is another +notion of something called a library so + + align:start position:0% +notion of something called a library so + + + align:start position:0% +notion of something called a library so +how you do simple resolution with + + align:start position:0% +how you do simple resolution with + + + align:start position:0% +how you do simple resolution with +library so + + align:start position:0% + + + + align:start position:0% + +an example of a library here is the is + + align:start position:0% +an example of a library here is the is + + + align:start position:0% +an example of a library here is the is +Lib C dot a which is the standard c + + align:start position:0% +Lib C dot a which is the standard c + + + align:start position:0% +Lib C dot a which is the standard c +library and that's the library that + + align:start position:0% +library and that's the library that + + + align:start position:0% +library and that's the library that +contains the definition of printf so if + + align:start position:0% +contains the definition of printf so if + + + align:start position:0% +contains the definition of printf so if +you use printf or any of these other + + align:start position:0% +you use printf or any of these other + + + align:start position:0% +you use printf or any of these other +standard functions they define the c + + align:start position:0% +standard functions they define the c + + + align:start position:0% +standard functions they define the c +library another example is the math + + align:start position:0% +library another example is the math + + + align:start position:0% +library another example is the math +library where you have the square root + + align:start position:0% +library where you have the square root + + + align:start position:0% +library where you have the square root +function and a bunch of other + + align:start position:0% +function and a bunch of other + + + align:start position:0% +function and a bunch of other +mathematical functions so we're going to + + align:start position:0% +mathematical functions so we're going to + + + align:start position:0% +mathematical functions so we're going to +want to know how to resolve with the + + align:start position:0% +want to know how to resolve with the + + + align:start position:0% +want to know how to resolve with the +libraries so first we have to know what + + align:start position:0% +libraries so first we have to know what + + + align:start position:0% +libraries so first we have to know what +a library is and what a library is is + + align:start position:0% +a library is and what a library is is + + + align:start position:0% +a library is and what a library is is +just you take a bunch of object files + + align:start position:0% +just you take a bunch of object files + + + align:start position:0% +just you take a bunch of object files +together and basically just concatenate + + align:start position:0% +together and basically just concatenate + + + align:start position:0% +together and basically just concatenate +them together it's not little not + + align:start position:0% +them together it's not little not + + + align:start position:0% +them together it's not little not +literally concatenation because the + + align:start position:0% +literally concatenation because the + + + align:start position:0% +literally concatenation because the +library also maintains an index that + + align:start position:0% +library also maintains an index that + + + align:start position:0% +library also maintains an index that +says um has information about what + + align:start position:0% +says um has information about what + + + align:start position:0% +says um has information about what +modules there is what include what + + align:start position:0% +modules there is what include what + + + align:start position:0% +modules there is what include what +included Gardo files contain which + + align:start position:0% +included Gardo files contain which + + + align:start position:0% +included Gardo files contain which +symbol definitions but essentially it's + + align:start position:0% +symbol definitions but essentially it's + + + align:start position:0% +symbol definitions but essentially it's +just a concatenation of all of the of a + + align:start position:0% +just a concatenation of all of the of a + + + align:start position:0% +just a concatenation of all of the of a +bunch of dot o files ok and they get put + + align:start position:0% +bunch of dot o files ok and they get put + + + align:start position:0% +bunch of dot o files ok and they get put +together in library and there's some + + align:start position:0% +together in library and there's some + + + align:start position:0% +together in library and there's some +index information in front that says + + align:start position:0% +index information in front that says + + + align:start position:0% +index information in front that says +what's where inside the library ok so + + align:start position:0% +what's where inside the library ok so + + + align:start position:0% +what's where inside the library ok so +the approach to resolving symbols with + + align:start position:0% +the approach to resolving symbols with + + + align:start position:0% +the approach to resolving symbols with +the library is almost the same as what + + align:start position:0% +the library is almost the same as what + + + align:start position:0% +the library is almost the same as what +we have so far except with one twist and + + align:start position:0% +we have so far except with one twist and + + + align:start position:0% +we have so far except with one twist and +the twist is that often libraries are + + align:start position:0% +the twist is that often libraries are + + + align:start position:0% +the twist is that often libraries are +extremely big much bigger than a single + + align:start position:0% +extremely big much bigger than a single + + + align:start position:0% +extremely big much bigger than a single +dot o file and one + + align:start position:0% +dot o file and one + + + align:start position:0% +dot o file and one +approach to resolving with libraries + + align:start position:0% +approach to resolving with libraries + + + align:start position:0% +approach to resolving with libraries +would be to apply the same approach here + + align:start position:0% +would be to apply the same approach here + + + align:start position:0% +would be to apply the same approach here +so when you have something that's + + align:start position:0% +so when you have something that's + + + align:start position:0% +so when you have something that's +defined in the standard c library like + + align:start position:0% +defined in the standard c library like + + + align:start position:0% +defined in the standard c library like +Lib C or the math library like Lib M you + + align:start position:0% +Lib C or the math library like Lib M you + + + align:start position:0% +Lib C or the math library like Lib M you +could just include the entire text of + + align:start position:0% +could just include the entire text of + + + align:start position:0% +could just include the entire text of +the library inside to build your program + + align:start position:0% +the library inside to build your program + + + align:start position:0% +the library inside to build your program +but that just makes things extremely + + align:start position:0% +but that just makes things extremely + + + align:start position:0% +but that just makes things extremely +bloated I mean think about if you just + + align:start position:0% +bloated I mean think about if you just + + + align:start position:0% +bloated I mean think about if you just +wanted to use printf in your program + + align:start position:0% +wanted to use printf in your program + + + align:start position:0% +wanted to use printf in your program +like we had in this example and you have + + align:start position:0% +like we had in this example and you have + + + align:start position:0% +like we had in this example and you have +to include the entire C library which is + + align:start position:0% +to include the entire C library which is + + + align:start position:0% +to include the entire C library which is +megabytes long that seems like not a + + align:start position:0% +megabytes long that seems like not a + + + align:start position:0% +megabytes long that seems like not a +good way of of doing the linking so what + + align:start position:0% +good way of of doing the linking so what + + + align:start position:0% +good way of of doing the linking so what +we're going to do with resolution with + + align:start position:0% +we're going to do with resolution with + + + align:start position:0% +we're going to do with resolution with +libraries is essentially the idea is to + + align:start position:0% +libraries is essentially the idea is to + + + align:start position:0% +libraries is essentially the idea is to +only include on the dot o files that are + + align:start position:0% +only include on the dot o files that are + + + align:start position:0% +only include on the dot o files that are +in the library in which undefined + + align:start position:0% +in the library in which undefined + + + align:start position:0% +in the library in which undefined +symbols that were previous encountered + + align:start position:0% +symbols that were previous encountered + + + align:start position:0% +symbols that were previous encountered +are defined and if + + align:start position:0% +are defined and if + + + align:start position:0% +are defined and if +you think a little bit about what I said + + align:start position:0% +you think a little bit about what I said + + + align:start position:0% +you think a little bit about what I said +that's one reason why it's usually a + + align:start position:0% +that's one reason why it's usually a + + + align:start position:0% +that's one reason why it's usually a +good idea when you you know do GCC um + + align:start position:0% +good idea when you you know do GCC um + + + align:start position:0% +good idea when you you know do GCC um +and use the linker use LD to specify the + + align:start position:0% +and use the linker use LD to specify the + + + align:start position:0% +and use the linker use LD to specify the +libraries at the end because what we're + + align:start position:0% +libraries at the end because what we're + + + align:start position:0% +libraries at the end because what we're +going to do is we're going to take all + + align:start position:0% +going to do is we're going to take all + + + align:start position:0% +going to do is we're going to take all +the rotor files and then there are going + + align:start position:0% +the rotor files and then there are going + + + align:start position:0% +the rotor files and then there are going +to be things like - LM I mean the list + + align:start position:0% +to be things like - LM I mean the list + + + align:start position:0% +to be things like - LM I mean the list +standard c library is usually by default + + align:start position:0% +standard c library is usually by default + + + align:start position:0% +standard c library is usually by default +already included on this on this + + align:start position:0% +already included on this on this + + + align:start position:0% +already included on this on this +command-line but if you have functions + + align:start position:0% +command-line but if you have functions + + + align:start position:0% +command-line but if you have functions +like square root and so on here what + + align:start position:0% +like square root and so on here what + + + align:start position:0% +like square root and so on here what +we're going to do is we're going to + + align:start position:0% +we're going to do is we're going to + + + align:start position:0% +we're going to do is we're going to +build up what the linker is going to do + + align:start position:0% +build up what the linker is going to do + + + align:start position:0% +build up what the linker is going to do +is it's going to build up a set of + + align:start position:0% +is it's going to build up a set of + + + align:start position:0% +is it's going to build up a set of +undefined symbols until it gets to the + + align:start position:0% +undefined symbols until it gets to the + + + align:start position:0% +undefined symbols until it gets to the +end and there's going to be undefined + + align:start position:0% +end and there's going to be undefined + + + align:start position:0% +end and there's going to be undefined +symbols remaining if you use the square + + align:start position:0% +symbols remaining if you use the square + + + align:start position:0% +symbols remaining if you use the square +root program the square root function + + align:start position:0% +root program the square root function + + + align:start position:0% +root program the square root function +and you didn't write your own square + + align:start position:0% +and you didn't write your own square + + + align:start position:0% +and you didn't write your own square +root function it's in the math library + + align:start position:0% +root function it's in the math library + + + align:start position:0% +root function it's in the math library +then you know you might ask for the math + + align:start position:0% +then you know you might ask for the math + + + align:start position:0% +then you know you might ask for the math +library to be included and you want to + + align:start position:0% +library to be included and you want to + + + align:start position:0% +library to be included and you want to +pull the definition of square root from + + align:start position:0% +pull the definition of square root from + + + align:start position:0% +pull the definition of square root from +the math library the + + align:start position:0% +the math library the + + + align:start position:0% +the math library the +way in which the linker knows to pull + + align:start position:0% +way in which the linker knows to pull + + + align:start position:0% +way in which the linker knows to pull +the right dot o file is that the math + + align:start position:0% +the right dot o file is that the math + + + align:start position:0% +the right dot o file is that the math +library is going to have information + + align:start position:0% +library is going to have information + + + align:start position:0% +library is going to have information +that says which object file contains our + + align:start position:0% +that says which object file contains our + + + align:start position:0% +that says which object file contains our +watch symbols and anytime + + align:start position:0% +watch symbols and anytime + + + align:start position:0% +watch symbols and anytime +you see an undefined symbol at this + + align:start position:0% +you see an undefined symbol at this + + + align:start position:0% +you see an undefined symbol at this +stage we're going to scan this archive + + align:start position:0% +stage we're going to scan this archive + + + align:start position:0% +stage we're going to scan this archive +looking for the symbol that's been + + align:start position:0% +looking for the symbol that's been + + + align:start position:0% +looking for the symbol that's been +undefined in particular looking in this + + align:start position:0% +undefined in particular looking in this + + + align:start position:0% +undefined in particular looking in this +example for the square root symbol okay + + align:start position:0% +example for the square root symbol okay + + + align:start position:0% +example for the square root symbol okay +and when we find the square root symbol + + align:start position:0% +and when we find the square root symbol + + + align:start position:0% +and when we find the square root symbol +somewhere inside in some dot o file + + align:start position:0% +somewhere inside in some dot o file + + + align:start position:0% +somewhere inside in some dot o file +we're going to take that dot o file and + + align:start position:0% +we're going to take that dot o file and + + + align:start position:0% +we're going to take that dot o file and +not the rest of the library and then use + + align:start position:0% +not the rest of the library and then use + + + align:start position:0% +not the rest of the library and then use +this algorithm that we did so take that + + align:start position:0% +this algorithm that we did so take that + + + align:start position:0% +this algorithm that we did so take that +dot o file agree alone and push that as + + align:start position:0% +dot o file agree alone and push that as + + + align:start position:0% +dot o file agree alone and push that as +input to this algorithm okay that's the + + align:start position:0% +input to this algorithm okay that's the + + + align:start position:0% +input to this algorithm okay that's the +way in which we're going to build it up + + align:start position:0% +way in which we're going to build it up + + + align:start position:0% +way in which we're going to build it up +so that's why at least in this + + align:start position:0% +so that's why at least in this + + + align:start position:0% +so that's why at least in this +particular implementation of the + + align:start position:0% +particular implementation of the + + + align:start position:0% +particular implementation of the +algorithm which is of the linker which + + align:start position:0% +algorithm which is of the linker which + + + align:start position:0% +algorithm which is of the linker which +is very simple if you put the LM way up + + align:start position:0% +is very simple if you put the LM way up + + + align:start position:0% +is very simple if you put the LM way up +in front you're a little bit in trouble + + align:start position:0% +in front you're a little bit in trouble + + + align:start position:0% +in front you're a little bit in trouble +because if F m dot o is the file that + + align:start position:0% +because if F m dot o is the file that + + + align:start position:0% +because if F m dot o is the file that +actually uses square root and the math + + align:start position:0% +actually uses square root and the math + + + align:start position:0% +actually uses square root and the math +library was included well in front then + + align:start position:0% +library was included well in front then + + + align:start position:0% +library was included well in front then +it wouldn't square root would not yet + + align:start position:0% +it wouldn't square root would not yet + + + align:start position:0% +it wouldn't square root would not yet +have been part of the undefined set of + + align:start position:0% +have been part of the undefined set of + + + align:start position:0% +have been part of the undefined set of +symbols um until then and you + + align:start position:0% +symbols um until then and you + + + align:start position:0% +symbols um until then and you +know there are other ways to deal with + + align:start position:0% +know there are other ways to deal with + + + align:start position:0% +know there are other ways to deal with +it you could have linkers that go in + + align:start position:0% +it you could have linkers that go in + + + align:start position:0% +it you could have linkers that go in +more passes that presumably can deal + + align:start position:0% +more passes that presumably can deal + + + align:start position:0% +more passes that presumably can deal +with this problem but this is just an + + align:start position:0% +with this problem but this is just an + + + align:start position:0% +with this problem but this is just an +example of how gnu/linux does this and + + align:start position:0% +example of how gnu/linux does this and + + + align:start position:0% +example of how gnu/linux does this and +it's just worth knowing ok so this idea + + align:start position:0% +it's just worth knowing ok so this idea + + + align:start position:0% +it's just worth knowing ok so this idea +of linking and uhm you know simple + + align:start position:0% +of linking and uhm you know simple + + + align:start position:0% +of linking and uhm you know simple +resolution and relocation Ben you know + + align:start position:0% +resolution and relocation Ben you know + + + align:start position:0% +resolution and relocation Ben you know +people have worked on this for a very + + align:start position:0% +people have worked on this for a very + + + align:start position:0% +people have worked on this for a very +long time and almost every software + + align:start position:0% +long time and almost every software + + + align:start position:0% +long time and almost every software +system uses it in fact if you use latex + + align:start position:0% +system uses it in fact if you use latex + + + align:start position:0% +system uses it in fact if you use latex +to build your you know design papers and + + align:start position:0% +to build your you know design papers and + + + align:start position:0% +to build your you know design papers and +so on um it does a version of symbol as + + align:start position:0% +so on um it does a version of symbol as + + + align:start position:0% +so on um it does a version of symbol as +it does symbol resolution as well + + align:start position:0% +it does symbol resolution as well + + + align:start position:0% +it does symbol resolution as well +because there's all sorts of cross + + align:start position:0% +because there's all sorts of cross + + + align:start position:0% +because there's all sorts of cross +references that are there and later and + + align:start position:0% +references that are there and later and + + + align:start position:0% +references that are there and later and +uses essentially the same kinds of + + align:start position:0% +uses essentially the same kinds of + + + align:start position:0% +uses essentially the same kinds of +algorithms go over the files and go over + + align:start position:0% +algorithms go over the files and go over + + + align:start position:0% +algorithms go over the files and go over +the documents in multiple passes and + + align:start position:0% +the documents in multiple passes and + + + align:start position:0% +the documents in multiple passes and +resolve the symbols so it's a pretty + + align:start position:0% +resolve the symbols so it's a pretty + + + align:start position:0% +resolve the symbols so it's a pretty +general algorithm that we've described + + align:start position:0% +general algorithm that we've described + + + align:start position:0% +general algorithm that we've described +here of building these different sets or + + align:start position:0% +here of building these different sets or + + + align:start position:0% +here of building these different sets or +to ultimately figure out whether there + + align:start position:0% +to ultimately figure out whether there + + + align:start position:0% +to ultimately figure out whether there +are undefined references remaining at + + align:start position:0% +are undefined references remaining at + + + align:start position:0% +are undefined references remaining at +the end or not so + + align:start position:0% + + + + align:start position:0% + +I want to step back for a minute and + + align:start position:0% +I want to step back for a minute and + + + align:start position:0% +I want to step back for a minute and +generalize on the different approaches + + align:start position:0% +generalize on the different approaches + + + align:start position:0% +generalize on the different approaches +that we've seen so far for doing on + + align:start position:0% +that we've seen so far for doing on + + + align:start position:0% +that we've seen so far for doing on +symbol resolution and today we saw one + + align:start position:0% +symbol resolution and today we saw one + + + align:start position:0% +symbol resolution and today we saw one +approach for doing symbol resolution but + + align:start position:0% +approach for doing symbol resolution but + + + align:start position:0% +approach for doing symbol resolution but +in fact last time we saw a couple of + + align:start position:0% +in fact last time we saw a couple of + + + align:start position:0% +in fact last time we saw a couple of +different approaches to resolve the arm + + align:start position:0% +different approaches to resolve the arm + + + align:start position:0% +different approaches to resolve the arm +names whose values we didn't actually + + align:start position:0% +names whose values we didn't actually + + + align:start position:0% +names whose values we didn't actually +know so we're going to step back and + + align:start position:0% +know so we're going to step back and + + + align:start position:0% +know so we're going to step back and +generalize with a couple of different + + align:start position:0% +generalize with a couple of different + + + align:start position:0% +generalize with a couple of different +example into three techniques that we + + align:start position:0% +example into three techniques that we + + + align:start position:0% +example into three techniques that we +saw from the different examples so + + align:start position:0% +saw from the different examples so + + + align:start position:0% +saw from the different examples so +the general problem here on the + + align:start position:0% +the general problem here on the + + + align:start position:0% +the general problem here on the +specifics are you know how you identify + + align:start position:0% +specifics are you know how you identify + + + align:start position:0% +specifics are you know how you identify +how you can find out where these + + align:start position:0% +how you can find out where these + + + align:start position:0% +how you can find out where these +undefined symbols are defined or in the + + align:start position:0% +undefined symbols are defined or in the + + + align:start position:0% +undefined symbols are defined or in the +UNIX example how you can take a big fat + + align:start position:0% +UNIX example how you can take a big fat + + + align:start position:0% +UNIX example how you can take a big fat +name and identify which blocks contain + + align:start position:0% +name and identify which blocks contain + + + align:start position:0% +name and identify which blocks contain +which disk blocks contain the files or + + align:start position:0% +which disk blocks contain the files or + + + align:start position:0% +which disk blocks contain the files or +contain the data for the file that was + + align:start position:0% +contain the data for the file that was + + + align:start position:0% +contain the data for the file that was +named in the path but the general + + align:start position:0% +named in the path but the general + + + align:start position:0% +named in the path but the general +problem is you have a set of names and + + align:start position:0% +problem is you have a set of names and + + + align:start position:0% +problem is you have a set of names and +associated + + align:start position:0% +associated + + + align:start position:0% +associated +with these names or with each name is a + + align:start position:0% +with these names or with each name is a + + + align:start position:0% +with these names or with each name is a +value and + + align:start position:0% + + + + align:start position:0% + +these names get associated with or + + align:start position:0% +these names get associated with or + + + align:start position:0% +these names get associated with or +mapped to the different values in fact + + align:start position:0% +mapped to the different values in fact + + + align:start position:0% +mapped to the different values in fact +the names get bound to the different + + align:start position:0% +the names get bound to the different + + + align:start position:0% +the names get bound to the different +values and in this example the linker + + align:start position:0% +values and in this example the linker + + + align:start position:0% +values and in this example the linker +easier to take a name like the + + align:start position:0% +easier to take a name like the + + + align:start position:0% +easier to take a name like the +definition of a symbol and needed to + + align:start position:0% +definition of a symbol and needed to + + + align:start position:0% +definition of a symbol and needed to +identify what's the value associated + + align:start position:0% +identify what's the value associated + + + align:start position:0% +identify what's the value associated +with that symbol the value here in this + + align:start position:0% +with that symbol the value here in this + + + align:start position:0% +with that symbol the value here in this +context is where is this name the square + + align:start position:0% +context is where is this name the square + + + align:start position:0% +context is where is this name the square +root or program the square root function + + align:start position:0% +root or program the square root function + + + align:start position:0% +root or program the square root function +where is it actually defined at what + + align:start position:0% +where is it actually defined at what + + + align:start position:0% +where is it actually defined at what +location is it okay and so the way in + + align:start position:0% +location is it okay and so the way in + + + align:start position:0% +location is it okay and so the way in +which that resolution is going to be + + align:start position:0% +which that resolution is going to be + + + align:start position:0% +which that resolution is going to be +done is gone in general is using + + align:start position:0% +done is gone in general is using + + + align:start position:0% +done is gone in general is using +something called a name mapping + + align:start position:0% +something called a name mapping + + + align:start position:0% +something called a name mapping +algorithm and + + align:start position:0% + + + + align:start position:0% + +the mapping of a name to value being + + align:start position:0% +the mapping of a name to value being + + + align:start position:0% +the mapping of a name to value being +done by name acting mapping algorithm + + align:start position:0% +done by name acting mapping algorithm + + + align:start position:0% +done by name acting mapping algorithm +takes into account or takes us in it + + align:start position:0% +takes into account or takes us in it + + + align:start position:0% +takes into account or takes us in it +takes as input something called a + + align:start position:0% +takes as input something called a + + + align:start position:0% +takes as input something called a +context and I'll describe this with an + + align:start position:0% +context and I'll describe this with an + + + align:start position:0% +context and I'll describe this with an +example in a minute so name gets is + + align:start position:0% +example in a minute so name gets is + + + align:start position:0% +example in a minute so name gets is +bound to value somebody's bound a name + + align:start position:0% +bound to value somebody's bound a name + + + align:start position:0% +bound to value somebody's bound a name +to value and then when you're a linker + + align:start position:0% +to value and then when you're a linker + + + align:start position:0% +to value and then when you're a linker +or when you're you know a part of the + + align:start position:0% +or when you're you know a part of the + + + align:start position:0% +or when you're you know a part of the +UNIX file system and you're trying to + + align:start position:0% +UNIX file system and you're trying to + + + align:start position:0% +UNIX file system and you're trying to +identify the value associated with the + + align:start position:0% +identify the value associated with the + + + align:start position:0% +identify the value associated with the +name you're going to have to resolve + + align:start position:0% +name you're going to have to resolve + + + align:start position:0% +name you're going to have to resolve +that name to find a value and that + + align:start position:0% +that name to find a value and that + + + align:start position:0% +that name to find a value and that +resolution is going to be done on in a + + align:start position:0% +resolution is going to be done on in a + + + align:start position:0% +resolution is going to be done on in a +particular context so for example you + + align:start position:0% +particular context so for example you + + + align:start position:0% +particular context so for example you +might have two files with the same name + + align:start position:0% +might have two files with the same name + + + align:start position:0% +might have two files with the same name +in two different directories and that's + + align:start position:0% +in two different directories and that's + + + align:start position:0% +in two different directories and that's +fine as long as the same name could have + + align:start position:0% +fine as long as the same name could have + + + align:start position:0% +fine as long as the same name could have +two different values because that + + align:start position:0% +two different values because that + + + align:start position:0% +two different values because that +resolution from the name to the correct + + align:start position:0% +resolution from the name to the correct + + + align:start position:0% +resolution from the name to the correct +value in that case in the directory case + + align:start position:0% +value in that case in the directory case + + + align:start position:0% +value in that case in the directory case +it's an inode number would be done in + + align:start position:0% +it's an inode number would be done in + + + align:start position:0% +it's an inode number would be done in +the context of the directory in which + + align:start position:0% +the context of the directory in which + + + align:start position:0% +the context of the directory in which +the resolution is being done okay so + + align:start position:0% +the resolution is being done okay so + + + align:start position:0% +the resolution is being done okay so +there's you know what we've seen over + + align:start position:0% +there's you know what we've seen over + + + align:start position:0% +there's you know what we've seen over +the past couple of days yes to the last + + align:start position:0% +the past couple of days yes to the last + + + align:start position:0% +the past couple of days yes to the last +lecture and today are three different + + align:start position:0% +lecture and today are three different + + + align:start position:0% +lecture and today are three different +ways of doing it and it will turn out + + align:start position:0% +ways of doing it and it will turn out + + + align:start position:0% +ways of doing it and it will turn out +that in almost every system or in every + + align:start position:0% +that in almost every system or in every + + + align:start position:0% +that in almost every system or in every +system that I know of anyway um there's + + align:start position:0% +system that I know of anyway um there's + + + align:start position:0% +system that I know of anyway um there's +basically three ways of doing this name + + align:start position:0% +basically three ways of doing this name + + + align:start position:0% +basically three ways of doing this name +resolution the first way the simplest + + align:start position:0% +resolution the first way the simplest + + + align:start position:0% +resolution the first way the simplest +way is a table lookup within + + align:start position:0% + + + + align:start position:0% + +the context of a dot o file knowing + + align:start position:0% +the context of a dot o file knowing + + + align:start position:0% +the context of a dot o file knowing +which simple and us which has a set of + + align:start position:0% +which simple and us which has a set of + + + align:start position:0% +which simple and us which has a set of +defined symbols taking one of those + + align:start position:0% +defined symbols taking one of those + + + align:start position:0% +defined symbols taking one of those +symbols the name in that case as input + + align:start position:0% +symbols the name in that case as input + + + align:start position:0% +symbols the name in that case as input +and finding out where it's being defined + + align:start position:0% +and finding out where it's being defined + + + align:start position:0% +and finding out where it's being defined +in that dot o file is basically a table + + align:start position:0% +in that dot o file is basically a table + + + align:start position:0% +in that dot o file is basically a table +lookup that's what that symbol table + + align:start position:0% +lookup that's what that symbol table + + + align:start position:0% +lookup that's what that symbol table +sections are described from the disk + + align:start position:0% +sections are described from the disk + + + align:start position:0% +sections are described from the disk +example from last time the inode table + + align:start position:0% +example from last time the inode table + + + align:start position:0% +example from last time the inode table +is an example of a table lookup and this + + align:start position:0% +is an example of a table lookup and this + + + align:start position:0% +is an example of a table lookup and this +is a portion of disk that has in it or + + align:start position:0% +is a portion of disk that has in it or + + + align:start position:0% +is a portion of disk that has in it or +the mapping between you know inode + + align:start position:0% +the mapping between you know inode + + + align:start position:0% +the mapping between you know inode +numbers and the corresponding inode and + + align:start position:0% +numbers and the corresponding inode and + + + align:start position:0% +numbers and the corresponding inode and +that's just a table lookup so when you + + align:start position:0% +that's just a table lookup so when you + + + align:start position:0% +that's just a table lookup so when you +want to go from an inode number to an + + align:start position:0% +want to go from an inode number to an + + + align:start position:0% +want to go from an inode number to an +inode you do a table lookup and that's + + align:start position:0% +inode you do a table lookup and that's + + + align:start position:0% +inode you do a table lookup and that's +the simplest base form base case of how + + align:start position:0% +the simplest base form base case of how + + + align:start position:0% +the simplest base form base case of how +this name resolution is done the + + align:start position:0% +this name resolution is done the + + + align:start position:0% +this name resolution is done the +second way of doing name resolution is + + align:start position:0% +second way of doing name resolution is + + + align:start position:0% +second way of doing name resolution is +something called a path name + + align:start position:0% +something called a path name + + + align:start position:0% +something called a path name +we + + align:start position:0% + + + + align:start position:0% + +didn't see an example of this today but + + align:start position:0% +didn't see an example of this today but + + + align:start position:0% +didn't see an example of this today but +we saw an example of pathname resolution + + align:start position:0% +we saw an example of pathname resolution + + + align:start position:0% +we saw an example of pathname resolution +the last time if you take a big UNIX pad + + align:start position:0% +the last time if you take a big UNIX pad + + + align:start position:0% +the last time if you take a big UNIX pad +name slash home slash food slash bar on + + align:start position:0% +name slash home slash food slash bar on + + + align:start position:0% +name slash home slash food slash bar on +what we did was cut left to right along + + align:start position:0% +what we did was cut left to right along + + + align:start position:0% +what we did was cut left to right along +that path and narrow down our so our + + align:start position:0% +that path and narrow down our so our + + + align:start position:0% +that path and narrow down our so our +resolution of the file you know to get + + align:start position:0% +resolution of the file you know to get + + + align:start position:0% +resolution of the file you know to get +to the block that we wanted while going + + align:start position:0% +to the block that we wanted while going + + + align:start position:0% +to the block that we wanted while going +through a search path through a path + + align:start position:0% +through a search path through a path + + + align:start position:0% +through a search path through a path +study not a search part but going + + align:start position:0% +study not a search part but going + + + align:start position:0% +study not a search part but going +through the path that names the item the + + align:start position:0% +through the path that names the item the + + + align:start position:0% +through the path that names the item the +third way of doing a simple resume + + align:start position:0% +third way of doing a simple resume + + + align:start position:0% +third way of doing a simple resume +resolution is what we saw today and + + align:start position:0% +resolution is what we saw today and + + + align:start position:0% +resolution is what we saw today and +that's an example of searching + + align:start position:0% +that's an example of searching + + + align:start position:0% +that's an example of searching +through contexts there's + + align:start position:0% + + + + align:start position:0% + +really no path here I just tell you + + align:start position:0% +really no path here I just tell you + + + align:start position:0% +really no path here I just tell you +here's the set of dot o files and here's + + align:start position:0% +here's the set of dot o files and here's + + + align:start position:0% +here's the set of dot o files and here's +a set of libraries and the symbols that + + align:start position:0% +a set of libraries and the symbols that + + + align:start position:0% +a set of libraries and the symbols that +are undefined or defined in different + + align:start position:0% +are undefined or defined in different + + + align:start position:0% +are undefined or defined in different +modules of my program or referred to in + + align:start position:0% +modules of my program or referred to in + + + align:start position:0% +modules of my program or referred to in +different modules of my program or + + align:start position:0% +different modules of my program or + + + align:start position:0% +different modules of my program or +defined somewhere among these modules + + align:start position:0% +defined somewhere among these modules + + + align:start position:0% +defined somewhere among these modules +and I'm not really going to tell the + + align:start position:0% +and I'm not really going to tell the + + + align:start position:0% +and I'm not really going to tell the +linker what's being defined where it's + + align:start position:0% +linker what's being defined where it's + + + align:start position:0% +linker what's being defined where it's +up to the linker to figure it out and it + + align:start position:0% +up to the linker to figure it out and it + + + align:start position:0% +up to the linker to figure it out and it +does that by basically running a search + + align:start position:0% +does that by basically running a search + + + align:start position:0% +does that by basically running a search +through a variety of different contexts + + align:start position:0% +through a variety of different contexts + + + align:start position:0% +through a variety of different contexts +so each dot o file and each library is a + + align:start position:0% +so each dot o file and each library is a + + + align:start position:0% +so each dot o file and each library is a +new context in which a search for + + align:start position:0% +new context in which a search for + + + align:start position:0% +new context in which a search for +previously undefined symbol happens and + + align:start position:0% +previously undefined symbol happens and + + + align:start position:0% +previously undefined symbol happens and +in + + align:start position:0% +in + + + align:start position:0% +in +this particular case the search within + + align:start position:0% +this particular case the search within + + + align:start position:0% +this particular case the search within +each context takes the form of a table + + align:start position:0% +each context takes the form of a table + + + align:start position:0% +each context takes the form of a table +lookup ok so those are the two um those + + align:start position:0% +lookup ok so those are the two um those + + + align:start position:0% +lookup ok so those are the two um those +are the three techniques for how you do + + align:start position:0% +are the three techniques for how you do + + + align:start position:0% +are the three techniques for how you do +name resolution in general and we saw + + align:start position:0% +name resolution in general and we saw + + + align:start position:0% +name resolution in general and we saw +two of them today and we saw two of them + + align:start position:0% +two of them today and we saw two of them + + + align:start position:0% +two of them today and we saw two of them +or the first two of the last time when + + align:start position:0% +or the first two of the last time when + + + align:start position:0% +or the first two of the last time when +we talked about the UNIX file system + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +the last step in the process of what a + + align:start position:0% +the last step in the process of what a + + + align:start position:0% +the last step in the process of what a +linker does after symbol resolution and + + align:start position:0% +linker does after symbol resolution and + + + align:start position:0% +linker does after symbol resolution and +relocation relocation in this particular + + align:start position:0% +relocation relocation in this particular + + + align:start position:0% +relocation relocation in this particular +kind of linking I didn't use the term + + align:start position:0% +kind of linking I didn't use the term + + + align:start position:0% +kind of linking I didn't use the term +but this form of linking is called + + align:start position:0% +but this form of linking is called + + + align:start position:0% +but this form of linking is called +static linking because we're going to + + align:start position:0% +static linking because we're going to + + + align:start position:0% +static linking because we're going to +take all of these different object files + + align:start position:0% +take all of these different object files + + + align:start position:0% +take all of these different object files +and defined on the command line or in + + align:start position:0% +and defined on the command line or in + + + align:start position:0% +and defined on the command line or in +the library and build together a single + + align:start position:0% +the library and build together a single + + + align:start position:0% +the library and build together a single +single big binary that has been linked + + align:start position:0% +single big binary that has been linked + + + align:start position:0% +single big binary that has been linked +so once up front when the linker is + + align:start position:0% +so once up front when the linker is + + + align:start position:0% +so once up front when the linker is +called that's called static linking + + align:start position:0% +called that's called static linking + + + align:start position:0% +called that's called static linking +internal relocation in that context is + + align:start position:0% +internal relocation in that context is + + + align:start position:0% +internal relocation in that context is +pretty straightforward but so we're not + + align:start position:0% +pretty straightforward but so we're not + + + align:start position:0% +pretty straightforward but so we're not +going to talk more about that except to + + align:start position:0% +going to talk more about that except to + + + align:start position:0% +going to talk more about that except to +note that there's relocation tables + + align:start position:0% +note that there's relocation tables + + + align:start position:0% +note that there's relocation tables +maintained in each object file but the + + align:start position:0% +maintained in each object file but the + + + align:start position:0% +maintained in each object file but the +third step is a little bit more slightly + + align:start position:0% +third step is a little bit more slightly + + + align:start position:0% +third step is a little bit more slightly +more complicated and actually varies a + + align:start position:0% +more complicated and actually varies a + + + align:start position:0% +more complicated and actually varies a +lot of depending + + align:start position:0% +lot of depending + + + align:start position:0% +lot of depending +on the system and that's program loading + + align:start position:0% +on the system and that's program loading + + + align:start position:0% +on the system and that's program loading +and + + align:start position:0% +and + + + align:start position:0% +and +the + + align:start position:0% +the + + + align:start position:0% +the +problem that solved by loading is that + + align:start position:0% +problem that solved by loading is that + + + align:start position:0% +problem that solved by loading is that +the linker produces an output program + + align:start position:0% +the linker produces an output program + + + align:start position:0% +the linker produces an output program +that's executable and you can run that + + align:start position:0% +that's executable and you can run that + + + align:start position:0% +that's executable and you can run that +program and in UNIX you run it by typing + + align:start position:0% +program and in UNIX you run it by typing + + + align:start position:0% +program and in UNIX you run it by typing +something on a command line or you know + + align:start position:0% +something on a command line or you know + + + align:start position:0% +something on a command line or you know +under windows you go click on something + + align:start position:0% +under windows you go click on something + + + align:start position:0% +under windows you go click on something +and effectively that invokes causes a + + align:start position:0% +and effectively that invokes causes a + + + align:start position:0% +and effectively that invokes causes a +shell to execute a program so + + align:start position:0% +shell to execute a program so + + + align:start position:0% +shell to execute a program so +somebody has to do the work of when you + + align:start position:0% +somebody has to do the work of when you + + + align:start position:0% +somebody has to do the work of when you +type a command something on the command + + align:start position:0% +type a command something on the command + + + align:start position:0% +type a command something on the command +line somebody has to do the work of + + align:start position:0% +line somebody has to do the work of + + + align:start position:0% +line somebody has to do the work of +looking at what file has been typed + + align:start position:0% +looking at what file has been typed + + + align:start position:0% +looking at what file has been typed +taking the contents of the file loading + + align:start position:0% +taking the contents of the file loading + + + align:start position:0% +taking the contents of the file loading +it up into memory passing control to + + align:start position:0% +it up into memory passing control to + + + align:start position:0% +it up into memory passing control to +something that can then start running + + align:start position:0% +something that can then start running + + + align:start position:0% +something that can then start running +the program and typically the place + + align:start position:0% +the program and typically the place + + + align:start position:0% +the program and typically the place +where that control is passed is the + + align:start position:0% +where that control is passed is the + + + align:start position:0% +where that control is passed is the +interpreter corresponding to the program + + align:start position:0% +interpreter corresponding to the program + + + align:start position:0% +interpreter corresponding to the program +so + + align:start position:0% +so + + + align:start position:0% +so +all of this work is done in UNIX by a + + align:start position:0% +all of this work is done in UNIX by a + + + align:start position:0% +all of this work is done in UNIX by a +program called exec ve ok + + align:start position:0% +program called exec ve ok + + + align:start position:0% +program called exec ve ok +so the actual loader in UNIX is a + + align:start position:0% +so the actual loader in UNIX is a + + + align:start position:0% +so the actual loader in UNIX is a +program called exactly E and it's job + + align:start position:0% +program called exactly E and it's job + + + align:start position:0% +program called exactly E and it's job +once you type in on the command line is + + align:start position:0% +once you type in on the command line is + + + align:start position:0% +once you type in on the command line is +the shell invokes it and what it does is + + align:start position:0% +the shell invokes it and what it does is + + + align:start position:0% +the shell invokes it and what it does is +to do what I said which is look at the + + align:start position:0% +to do what I said which is look at the + + + align:start position:0% +to do what I said which is look at the +file name take the contents of it load a + + align:start position:0% +file name take the contents of it load a + + + align:start position:0% +file name take the contents of it load a +cup into memory and pass control to the + + align:start position:0% +cup into memory and pass control to the + + + align:start position:0% +cup into memory and pass control to the +first arm basically the first line of + + align:start position:0% +first arm basically the first line of + + + align:start position:0% +first arm basically the first line of +the program it's usually a line often + + align:start position:0% +the program it's usually a line often + + + align:start position:0% +the program it's usually a line often +modern object files are a little more + + align:start position:0% +modern object files are a little more + + + align:start position:0% +modern object files are a little more +complicated they actually have in it + + align:start position:0% +complicated they actually have in it + + + align:start position:0% +complicated they actually have in it +something that says who the interpreter + + align:start position:0% +something that says who the interpreter + + + align:start position:0% +something that says who the interpreter +of the program is so you pass it pass + + align:start position:0% +of the program is so you pass it pass + + + align:start position:0% +of the program is so you pass it pass +control to that interpreter which in + + align:start position:0% +control to that interpreter which in + + + align:start position:0% +control to that interpreter which in +turn goes through a bunch of steps and + + align:start position:0% +turn goes through a bunch of steps and + + + align:start position:0% +turn goes through a bunch of steps and +then invokes the first line in main and + + align:start position:0% +then invokes the first line in main and + + + align:start position:0% +then invokes the first line in main and +that's what the C program of the C + + align:start position:0% +that's what the C program of the C + + + align:start position:0% +that's what the C program of the C +loader + + align:start position:0% +loader + + + align:start position:0% +loader +the way in which loading program that + + align:start position:0% +the way in which loading program that + + + align:start position:0% +the way in which loading program that +certain SC works so + + align:start position:0% + + + + align:start position:0% + +so far what we've seen is as I mentioned + + align:start position:0% +so far what we've seen is as I mentioned + + + align:start position:0% +so far what we've seen is as I mentioned +an example of linking called static + + align:start position:0% +an example of linking called static + + + align:start position:0% +an example of linking called static +linking where you take all these object + + align:start position:0% +linking where you take all these object + + + align:start position:0% +linking where you take all these object +files and libraries and extract the + + align:start position:0% +files and libraries and extract the + + + align:start position:0% +files and libraries and extract the +right object files out of it and build a + + align:start position:0% +right object files out of it and build a + + + align:start position:0% +right object files out of it and build a +big program so what you'll find is that + + align:start position:0% +big program so what you'll find is that + + + align:start position:0% +big program so what you'll find is that +even + + align:start position:0% +even + + + align:start position:0% +even +small programs like this one where all + + align:start position:0% +small programs like this one where all + + + align:start position:0% +small programs like this one where all +it's doing is you know multiplying two + + align:start position:0% +it's doing is you know multiplying two + + + align:start position:0% +it's doing is you know multiplying two +numbers if I compile it it's + + align:start position:0% + + + + align:start position:0% + +a pretty big almost 400 kilobytes I mean + + align:start position:0% +a pretty big almost 400 kilobytes I mean + + + align:start position:0% +a pretty big almost 400 kilobytes I mean +it's multiplying two numbers and it + + align:start position:0% +it's multiplying two numbers and it + + + align:start position:0% +it's multiplying two numbers and it +takes Florent kilobytes to multiply and + + align:start position:0% +takes Florent kilobytes to multiply and + + + align:start position:0% +takes Florent kilobytes to multiply and +the reason is that you know I made the + + align:start position:0% +the reason is that you know I made the + + + align:start position:0% +the reason is that you know I made the +mistake of including or you know I have + + align:start position:0% +mistake of including or you know I have + + + align:start position:0% +mistake of including or you know I have +to show the output to the user so I + + align:start position:0% +to show the output to the user so I + + + align:start position:0% +to show the output to the user so I +called printf and printf happens to be + + align:start position:0% +called printf and printf happens to be + + + align:start position:0% +called printf and printf happens to be +part of a big object file that defines a + + align:start position:0% +part of a big object file that defines a + + + align:start position:0% +part of a big object file that defines a +lot of other things and that whole thing + + align:start position:0% +lot of other things and that whole thing + + + align:start position:0% +lot of other things and that whole thing +got built + + align:start position:0% +got built + + + align:start position:0% +got built +as part of the program now if you have a + + align:start position:0% +as part of the program now if you have a + + + align:start position:0% +as part of the program now if you have a +lot of programs so it's not just that + + align:start position:0% +lot of programs so it's not just that + + + align:start position:0% +lot of programs so it's not just that +the files are big I mean disks as I + + align:start position:0% +the files are big I mean disks as I + + + align:start position:0% +the files are big I mean disks as I +mentioned a couple lectures ago you know + + align:start position:0% +mentioned a couple lectures ago you know + + + align:start position:0% +mentioned a couple lectures ago you know +disks are cheap and so that's not really + + align:start position:0% +disks are cheap and so that's not really + + + align:start position:0% +disks are cheap and so that's not really +the problem as much as the problem is + + align:start position:0% +the problem as much as the problem is + + + align:start position:0% +the problem as much as the problem is +that if you have this is the entire + + align:start position:0% +that if you have this is the entire + + + align:start position:0% +that if you have this is the entire +program so it has to get loaded in so if + + align:start position:0% +program so it has to get loaded in so if + + + align:start position:0% +program so it has to get loaded in so if +you have some kind of you know some + + align:start position:0% +you have some kind of you know some + + + align:start position:0% +you have some kind of you know some +machine on which 100 process is run and + + align:start position:0% +machine on which 100 process is run and + + + align:start position:0% +machine on which 100 process is run and +each of those processes has printf s-- + + align:start position:0% +each of those processes has printf s-- + + + align:start position:0% +each of those processes has printf s-- +in a few places or even do one printf + + align:start position:0% +in a few places or even do one printf + + + align:start position:0% +in a few places or even do one printf +each of those programs is going to be + + align:start position:0% +each of those programs is going to be + + + align:start position:0% +each of those programs is going to be +extremely big so + + align:start position:0% +extremely big so + + + align:start position:0% +extremely big so +the way in which you deal with this + + align:start position:0% +the way in which you deal with this + + + align:start position:0% +the way in which you deal with this +problem is to do something that's pretty + + align:start position:0% +problem is to do something that's pretty + + + align:start position:0% +problem is to do something that's pretty +obvious in retrospect why have multiple + + align:start position:0% +obvious in retrospect why have multiple + + + align:start position:0% +obvious in retrospect why have multiple +copies of the same module why don't we + + align:start position:0% +copies of the same module why don't we + + + align:start position:0% +copies of the same module why don't we +just have one copy of that module + + align:start position:0% +just have one copy of that module + + + align:start position:0% +just have one copy of that module +running in all of the programs that use + + align:start position:0% +running in all of the programs that use + + + align:start position:0% +running in all of the programs that use +that module and that's done using an + + align:start position:0% +that module and that's done using an + + + align:start position:0% +that module and that's done using an +idea called a shared object or + + align:start position:0% + + + + align:start position:0% + +shared object you know shared modules + + align:start position:0% +shared object you know shared modules + + + align:start position:0% +shared object you know shared modules +and this stuff is extremely hard around + + align:start position:0% +and this stuff is extremely hard around + + + align:start position:0% +and this stuff is extremely hard around +if you look at um recent activity in + + align:start position:0% +if you look at um recent activity in + + + align:start position:0% +if you look at um recent activity in +almost every modular software system + + align:start position:0% +almost every modular software system + + + align:start position:0% +almost every modular software system +like you look at a patch here or you + + align:start position:0% +like you look at a patch here or you + + + align:start position:0% +like you look at a patch here or you +look at you know many database systems + + align:start position:0% +look at you know many database systems + + + align:start position:0% +look at you know many database systems +and predict also you look at gnu/linux + + align:start position:0% +and predict also you look at gnu/linux + + + align:start position:0% +and predict also you look at gnu/linux +there's been a ton of activity over the + + align:start position:0% +there's been a ton of activity over the + + + align:start position:0% +there's been a ton of activity over the +past five or six years on different ways + + align:start position:0% +past five or six years on different ways + + + align:start position:0% +past five or six years on different ways +of optimizing things so that the idea is + + align:start position:0% +of optimizing things so that the idea is + + + align:start position:0% +of optimizing things so that the idea is +a very old idea but there's still been a + + align:start position:0% +a very old idea but there's still been a + + + align:start position:0% +a very old idea but there's still been a +lot of act really making it efficient + + align:start position:0% +lot of act really making it efficient + + + align:start position:0% +lot of act really making it efficient +and practical over the last you know + + align:start position:0% +and practical over the last you know + + + align:start position:0% +and practical over the last you know +five to ten years the + + align:start position:0% +five to ten years the + + + align:start position:0% +five to ten years the +problem with shared objects is the + + align:start position:0% +problem with shared objects is the + + + align:start position:0% +problem with shared objects is the +following and this will become a little + + align:start position:0% +following and this will become a little + + + align:start position:0% +following and this will become a little +more clear when we talk about actually + + align:start position:0% +more clear when we talk about actually + + + align:start position:0% +more clear when we talk about actually +how programs you know something called + + align:start position:0% +how programs you know something called + + + align:start position:0% +how programs you know something called +address an address space in a couple of + + align:start position:0% +address an address space in a couple of + + + align:start position:0% +address an address space in a couple of +lectures from now but the basic problem + + align:start position:0% +lectures from now but the basic problem + + + align:start position:0% +lectures from now but the basic problem +is that instructions are associated with + + align:start position:0% +is that instructions are associated with + + + align:start position:0% +is that instructions are associated with +memory locations and they're on you know + + align:start position:0% +memory locations and they're on you know + + + align:start position:0% +memory locations and they're on you know +each thing in the object file in the + + align:start position:0% +each thing in the object file in the + + + align:start position:0% +each thing in the object file in the +binary has an instruction location in it + + align:start position:0% +binary has an instruction location in it + + + align:start position:0% +binary has an instruction location in it +and data has a particular location + + align:start position:0% +and data has a particular location + + + align:start position:0% +and data has a particular location +associated with it as well and the + + align:start position:0% +associated with it as well and the + + + align:start position:0% +associated with it as well and the +problem is that when you have two + + align:start position:0% +problem is that when you have two + + + align:start position:0% +problem is that when you have two +programs on that each want to use a + + align:start position:0% +programs on that each want to use a + + + align:start position:0% +programs on that each want to use a +shared module unless + + align:start position:0% +shared module unless + + + align:start position:0% +shared module unless +you're really careful about how you + + align:start position:0% +you're really careful about how you + + + align:start position:0% +you're really careful about how you +design it it's going to be very hard for + + align:start position:0% +design it it's going to be very hard for + + + align:start position:0% +design it it's going to be very hard for +you to ensure that for both of those + + align:start position:0% +you to ensure that for both of those + + + align:start position:0% +you to ensure that for both of those +programs this module that's going to be + + align:start position:0% +programs this module that's going to be + + + align:start position:0% +programs this module that's going to be +shared has exactly the same addresses + + align:start position:0% +shared has exactly the same addresses + + + align:start position:0% +shared has exactly the same addresses +because if you have in one program the + + align:start position:0% +because if you have in one program the + + + align:start position:0% +because if you have in one program the +module being called from or set one one + + align:start position:0% +module being called from or set one one + + + align:start position:0% +module being called from or set one one +you know from address 17 and another + + align:start position:0% +you know from address 17 and another + + + align:start position:0% +you know from address 17 and another +program the module is you know written + + align:start position:0% +program the module is you know written + + + align:start position:0% +program the module is you know written +up as arm you know address 255 then that + + align:start position:0% +up as arm you know address 255 then that + + + align:start position:0% +up as arm you know address 255 then that +object cannot be shared right it's two + + align:start position:0% +object cannot be shared right it's two + + + align:start position:0% +object cannot be shared right it's two +different objects and that's what + + align:start position:0% +different objects and that's what + + + align:start position:0% +different objects and that's what +happens with static linking if you take + + align:start position:0% +happens with static linking if you take + + + align:start position:0% +happens with static linking if you take +the sqr dots a program sqr d'Oro module + + align:start position:0% +the sqr dots a program sqr d'Oro module + + + align:start position:0% +the sqr dots a program sqr d'Oro module +and you include that in two different + + align:start position:0% +and you include that in two different + + + align:start position:0% +and you include that in two different +programs the addresses that get + + align:start position:0% +programs the addresses that get + + + align:start position:0% +programs the addresses that get +associated with it in the two different + + align:start position:0% +associated with it in the two different + + + align:start position:0% +associated with it in the two different +programs are going to be completely + + align:start position:0% +programs are going to be completely + + + align:start position:0% +programs are going to be completely +different so + + align:start position:0% +different so + + + align:start position:0% +different so +the challenge one challenge and a + + align:start position:0% +the challenge one challenge and a + + + align:start position:0% +the challenge one challenge and a +significant one is in the share objects + + align:start position:0% +significant one is in the share objects + + + align:start position:0% +significant one is in the share objects +and is that our you know objects that + + align:start position:0% +and is that our you know objects that + + + align:start position:0% +and is that our you know objects that +are shared by different programs running + + align:start position:0% +are shared by different programs running + + + align:start position:0% +are shared by different programs running +at the same time is to generate code + + align:start position:0% +at the same time is to generate code + + + align:start position:0% +at the same time is to generate code +that is + + align:start position:0% +that is + + + align:start position:0% +that is +what is called position independent so + + align:start position:0% +what is called position independent so + + + align:start position:0% +what is called position independent so +it doesn't have in it anything that um + + align:start position:0% +it doesn't have in it anything that um + + + align:start position:0% +it doesn't have in it anything that um +it doesn't have anything in it anything + + align:start position:0% +it doesn't have anything in it anything + + + align:start position:0% +it doesn't have anything in it anything +that's different for the different + + align:start position:0% +that's different for the different + + + align:start position:0% +that's different for the different +programs and so this is our core + + align:start position:0% +programs and so this is our core + + + align:start position:0% +programs and so this is our core +position independent code so the idea is + + align:start position:0% +position independent code so the idea is + + + align:start position:0% +position independent code so the idea is +when you call the module on your + + align:start position:0% +when you call the module on your + + + align:start position:0% +when you call the module on your +computer the program counter is going to + + align:start position:0% +computer the program counter is going to + + + align:start position:0% +computer the program counter is going to +point to something and all of the + + align:start position:0% +point to something and all of the + + + align:start position:0% +point to something and all of the +addresses inside that module are going + + align:start position:0% +addresses inside that module are going + + + align:start position:0% +addresses inside that module are going +to have addresses they're going to have + + align:start position:0% +to have addresses they're going to have + + + align:start position:0% +to have addresses they're going to have +obviously they're going to have + + align:start position:0% +obviously they're going to have + + + align:start position:0% +obviously they're going to have +addresses but they're going to be + + align:start position:0% +addresses but they're going to be + + + align:start position:0% +addresses but they're going to be +relative to the program counter so when + + align:start position:0% +relative to the program counter so when + + + align:start position:0% +relative to the program counter so when +you jump to a location you're not going + + align:start position:0% +you jump to a location you're not going + + + align:start position:0% +you jump to a location you're not going +to jump to 317 you're going to jump to + + align:start position:0% +to jump to 317 you're going to jump to + + + align:start position:0% +to jump to 317 you're going to jump to +something that says five locations from + + align:start position:0% +something that says five locations from + + + align:start position:0% +something that says five locations from +where you are now so it's a kind of + + align:start position:0% +where you are now so it's a kind of + + + align:start position:0% +where you are now so it's a kind of +addressing called PC relative addressing + + align:start position:0% +addressing called PC relative addressing + + + align:start position:0% +addressing called PC relative addressing +and that's not going to be the only + + align:start position:0% +and that's not going to be the only + + + align:start position:0% +and that's not going to be the only +thing that's you but by-and-large a + + align:start position:0% +thing that's you but by-and-large a + + + align:start position:0% +thing that's you but by-and-large a +requirement for position independent + + align:start position:0% +requirement for position independent + + + align:start position:0% +requirement for position independent +code is that all of the addressing be + + align:start position:0% +code is that all of the addressing be + + + align:start position:0% +code is that all of the addressing be +relative to say the program counter and + + align:start position:0% +relative to say the program counter and + + + align:start position:0% +relative to say the program counter and +once + + align:start position:0% + + + + align:start position:0% + +you have this kind of position + + align:start position:0% +you have this kind of position + + + align:start position:0% +you have this kind of position +independent code arm what you have to do + + align:start position:0% +independent code arm what you have to do + + + align:start position:0% +independent code arm what you have to do +in your program if you're using + + align:start position:0% +in your program if you're using + + + align:start position:0% +in your program if you're using +something like the square root program + + align:start position:0% +something like the square root program + + + align:start position:0% +something like the square root program +let's say okay in the mat library when + + align:start position:0% +let's say okay in the mat library when + + + align:start position:0% +let's say okay in the mat library when +you do the linking you don't have to + + align:start position:0% +you do the linking you don't have to + + + align:start position:0% +you do the linking you don't have to +include the object file in which square + + align:start position:0% +include the object file in which square + + + align:start position:0% +include the object file in which square +root square root is defined all + + align:start position:0% +root square root is defined all + + + align:start position:0% +root square root is defined all +that your object file has to do now is + + align:start position:0% +that your object file has to do now is + + + align:start position:0% +that your object file has to do now is +at the time it was linked there is some + + align:start position:0% +at the time it was linked there is some + + + align:start position:0% +at the time it was linked there is some +library the runtime you know some + + align:start position:0% +library the runtime you know some + + + align:start position:0% +library the runtime you know some +library runtime library that you know + + align:start position:0% +library runtime library that you know + + + align:start position:0% +library runtime library that you know +when you links the program has the + + align:start position:0% +when you links the program has the + + + align:start position:0% +when you links the program has the +definition of square root so what the + + align:start position:0% +definition of square root so what the + + + align:start position:0% +definition of square root so what the +object what the program contains when + + align:start position:0% +object what the program contains when + + + align:start position:0% +object what the program contains when +you run arm you know this F 1 dot 0 F 2 + + align:start position:0% +you run arm you know this F 1 dot 0 F 2 + + + align:start position:0% +you run arm you know this F 1 dot 0 F 2 +dot o all the way through the library is + + align:start position:0% +dot o all the way through the library is + + + align:start position:0% +dot o all the way through the library is +it's just going to maintain a pointer a + + align:start position:0% +it's just going to maintain a pointer a + + + align:start position:0% +it's just going to maintain a pointer a +name actually it's going to make a name + + align:start position:0% +name actually it's going to make a name + + + align:start position:0% +name actually it's going to make a name +to where the square root function is + + align:start position:0% +to where the square root function is + + + align:start position:0% +to where the square root function is +defined it's going to be a file name + + align:start position:0% +defined it's going to be a file name + + + align:start position:0% +defined it's going to be a file name +okay and so this is why sometimes when + + align:start position:0% +okay and so this is why sometimes when + + + align:start position:0% +okay and so this is why sometimes when +you type in a program and somebody's + + align:start position:0% +you type in a program and somebody's + + + align:start position:0% +you type in a program and somebody's +change the configuration on your machine + + align:start position:0% +change the configuration on your machine + + + align:start position:0% +change the configuration on your machine +it built before and somebody change the + + align:start position:0% +it built before and somebody change the + + + align:start position:0% +it built before and somebody change the +configuration sometimes you get an error + + align:start position:0% +configuration sometimes you get an error + + + align:start position:0% +configuration sometimes you get an error +message while you're running the program + + align:start position:0% +message while you're running the program + + + align:start position:0% +message while you're running the program +you get an error message that says um + + align:start position:0% +you get an error message that says um + + + align:start position:0% +you get an error message that says um +you know some library dot s so not found + + align:start position:0% +you know some library dot s so not found + + + align:start position:0% +you know some library dot s so not found +you know it worked two days ago it + + align:start position:0% +you know it worked two days ago it + + + align:start position:0% +you know it worked two days ago it +doesn't work now and the reason for that + + align:start position:0% +doesn't work now and the reason for that + + + align:start position:0% +doesn't work now and the reason for that +is somebody may have moved things around + + align:start position:0% +is somebody may have moved things around + + + align:start position:0% +is somebody may have moved things around +and you get an error not when you + + align:start position:0% +and you get an error not when you + + + align:start position:0% +and you get an error not when you +compile the program but when you run the + + align:start position:0% +compile the program but when you run the + + + align:start position:0% +compile the program but when you run the +program and many executions of program + + align:start position:0% +program and many executions of program + + + align:start position:0% +program and many executions of program +may not actually trigger the error at + + align:start position:0% +may not actually trigger the error at + + + align:start position:0% +may not actually trigger the error at +all it may get triggered only when the + + align:start position:0% +all it may get triggered only when the + + + align:start position:0% +all it may get triggered only when the +actual object is needed and that's + + align:start position:0% +actual object is needed and that's + + + align:start position:0% +actual object is needed and that's +called dynamic linking and + + align:start position:0% +called dynamic linking and + + + align:start position:0% +called dynamic linking and +again the way in which we do dynamic + + align:start position:0% +again the way in which we do dynamic + + + align:start position:0% +again the way in which we do dynamic +linking is to use the same naming + + align:start position:0% +linking is to use the same naming + + + align:start position:0% +linking is to use the same naming +concepts rather than embed the entire + + align:start position:0% +concepts rather than embed the entire + + + align:start position:0% +concepts rather than embed the entire +object object file corresponding to an + + align:start position:0% +object object file corresponding to an + + + align:start position:0% +object object file corresponding to an +on the module which are corresponding to + + align:start position:0% +on the module which are corresponding to + + + align:start position:0% +on the module which are corresponding to +a name of a function that's being + + align:start position:0% +a name of a function that's being + + + align:start position:0% +a name of a function that's being +defined elsewhere maintain a reference + + align:start position:0% +defined elsewhere maintain a reference + + + align:start position:0% +defined elsewhere maintain a reference +to it and load that reference up at + + align:start position:0% +to it and load that reference up at + + + align:start position:0% +to it and load that reference up at +runtime now in order to enable that + + align:start position:0% +runtime now in order to enable that + + + align:start position:0% +runtime now in order to enable that +object to be shared between different + + align:start position:0% +object to be shared between different + + + align:start position:0% +object to be shared between different +programs all of the addressing inside + + align:start position:0% +programs all of the addressing inside + + + align:start position:0% +programs all of the addressing inside +that has to be relative that is has to + + align:start position:0% +that has to be relative that is has to + + + align:start position:0% +that has to be relative that is has to +be independent of independent of what + + align:start position:0% +be independent of independent of what + + + align:start position:0% +be independent of independent of what +the PCs value for the starting point of + + align:start position:0% +the PCs value for the starting point of + + + align:start position:0% +the PCs value for the starting point of +that module module is and that's called + + align:start position:0% +that module module is and that's called + + + align:start position:0% +that module module is and that's called +position independent code so + + align:start position:0% +position independent code so + + + align:start position:0% +position independent code so +that's the basic story behind how + + align:start position:0% +that's the basic story behind how + + + align:start position:0% +that's the basic story behind how +linking works + + align:start position:0% +linking works + + + align:start position:0% +linking works +and almost all software systems + + align:start position:0% +and almost all software systems + + + align:start position:0% +and almost all software systems +involving libraries and modules ends up + + align:start position:0% +involving libraries and modules ends up + + + align:start position:0% +involving libraries and modules ends up +having a linking in and I mentioned + + align:start position:0% +having a linking in and I mentioned + + + align:start position:0% +having a linking in and I mentioned +latex as an example before um even + + align:start position:0% +latex as an example before um even + + + align:start position:0% +latex as an example before um even +document systems have linking in it and + + align:start position:0% +document systems have linking in it and + + + align:start position:0% +document systems have linking in it and +it's pretty fundamental the algorithm + + align:start position:0% +it's pretty fundamental the algorithm + + + align:start position:0% +it's pretty fundamental the algorithm +that we talked about it specific to + + align:start position:0% +that we talked about it specific to + + + align:start position:0% +that we talked about it specific to +gnu/linux but the basic idea is pretty + + align:start position:0% +gnu/linux but the basic idea is pretty + + + align:start position:0% +gnu/linux but the basic idea is pretty +common now what we'll see next time is + + align:start position:0% +common now what we'll see next time is + + + align:start position:0% +common now what we'll see next time is +that this way of modularizing has a lot + + align:start position:0% +that this way of modularizing has a lot + + + align:start position:0% +that this way of modularizing has a lot +of nice properties allows you to build + + align:start position:0% +of nice properties allows you to build + + + align:start position:0% +of nice properties allows you to build +big programs but at the same time has + + align:start position:0% +big programs but at the same time has + + + align:start position:0% +big programs but at the same time has +pretty bad fault isolation properties + + align:start position:0% +pretty bad fault isolation properties + + + align:start position:0% +pretty bad fault isolation properties +that we'll talk about next time \ No newline at end of file